199 files changed, 83205 insertions, 0 deletions
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/ANNOUNCE b/libraries/irrlicht-1.8/source/Irrlicht/libpng/ANNOUNCE
new file mode 100644
index 0000000..e8498a3
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/ANNOUNCE
@@ -0,0 +1,42 @@
+Libpng 1.5.9 - February 18, 2012
+This is a public release of libpng, intended for use in production codes.
+Files available for download:
+Source files with LF line endings (for Unix/Linux) and with a
+"configure" script
+   libpng-1.5.9.tar.xz (LZMA-compressed, recommended)
+   libpng-1.5.9.tar.gz
+   libpng-1.5.9.tar.bz2
+Source files with CRLF line endings (for Windows), without the
+"configure" script
+   lpng159.7z  (LZMA-compressed, recommended)
+   lpng159.zip
+Other information:
+   libpng-1.5.9-README.txt
+   libpng-1.5.9-LICENSE.txt
+Changes since the last public release (1.5.8):
+  Rebuilt configure scripts in the tar distributions.
+  Removed two unused definitions from scripts/pnglibconf.h.prebuilt
+  Removed some unused arrays (with #ifdef) from png_read_push_finish_row().
+  Removed tests for no-longer-used *_EMPTY_PLTE_SUPPORTED from pngstruct.h
+  Fixed CVE-2011-3026 buffer overrun bug.  Deal more correctly with the test
+    on iCCP chunk length. Also removed spurious casts that may hide problems
+    on 16-bit systems.
+Send comments/corrections/commendations to png-mng-implement at lists.sf.net
+(subscription required; visit
+https://lists.sourceforge.net/lists/listinfo/png-mng-implement
+to subscribe)
+or to glennrp at users.sourceforge.net
+Glenn R-P
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/CHANGES b/libraries/irrlicht-1.8/source/Irrlicht/libpng/CHANGES
new file mode 100644
index 0000000..fb3a90b
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/CHANGES
@@ -0,0 +1,3820 @@
+#if 0
+CHANGES - changes for libpng
+Version 0.2
+  added reader into png.h
+  fixed small problems in stub file
+Version 0.3
+  added pull reader
+  split up pngwrite.c to several files
+  added pnglib.txt
+  added example.c
+  cleaned up writer, adding a few new transformations
+  fixed some bugs in writer
+  interfaced with zlib 0.5
+  added K&R support
+  added check for 64 KB blocks for 16-bit machines
+Version 0.4
+  cleaned up code and commented code
+  simplified time handling into png_time
+  created png_color_16 and png_color_8 to handle color needs
+  cleaned up color type defines
+  fixed various bugs
+  made various names more consistent
+  interfaced with zlib 0.71
+  cleaned up zTXt reader and writer (using zlib's Reset functions)
+  split transformations into pngrtran.c and pngwtran.c
+Version 0.5
+  interfaced with zlib 0.8
+  fixed many reading and writing bugs
+  saved using 3 spaces instead of tabs
+Version 0.6
+  added png_large_malloc() and png_large_free()
+  added png_size_t
+  cleaned up some compiler warnings
+  added png_start_read_image()
+Version 0.7
+  cleaned up lots of bugs
+  finished dithering and other stuff
+  added test program
+  changed name from pnglib to libpng
+Version 0.71 [June, 1995]
+  changed pngtest.png for zlib 0.93
+  fixed error in libpng.txt and example.c
+Version 0.8
+  cleaned up some bugs
+  added png_set_filler()
+  split up pngstub.c into pngmem.c, pngio.c, and pngerror.c
+  added #define's to remove unwanted code
+  moved png_info_init() to png.c
+  added old_size into png_realloc()
+  added functions to manually set filtering and compression info
+  changed compression parameters based on image type
+  optimized filter selection code
+  added version info
+  changed external functions passing floats to doubles (k&r problems?)
+  put all the configurable stuff in pngconf.h
+  enabled png_set_shift to work with paletted images on read
+  added png_read_update_info() - updates info structure with transformations
+Version 0.81 [August, 1995]
+  incorporated Tim Wegner's medium model code (thanks, Tim)
+Version 0.82 [September, 1995]
+  [unspecified changes]
+Version 0.85 [December, 1995]
+  added more medium model code (almost everything's a far)
+  added i/o, error, and memory callback functions
+  fixed some bugs (16-bit, 4-bit interlaced, etc.)
+  added first run progressive reader (barely tested)
+Version 0.86 [January, 1996]
+  fixed bugs
+  improved documentation
+Version 0.87 [January, 1996]
+  fixed medium model bugs
+  fixed other bugs introduced in 0.85 and 0.86
+  added some minor documentation
+Version 0.88 [January, 1996]
+  fixed progressive bugs
+  replaced tabs with spaces
+  cleaned up documentation
+  added callbacks for read/write and warning/error functions
+Version 0.89 [July, 1996]
+  Added new initialization API to make libpng work better with shared libs
+    we now have png_create_read_struct(), png_create_write_struct(),
+    png_create_info_struct(), png_destroy_read_struct(), and
+    png_destroy_write_struct() instead of the separate calls to
+    malloc and png_read_init(), png_info_init(), and png_write_init()
+  Changed warning/error callback functions to fix bug - this means you
+    should use the new initialization API if you were using the old
+    png_set_message_fn() calls, and that the old API no longer exists
+    so that people are aware that they need to change their code
+  Changed filter selection API to allow selection of multiple filters
+    since it didn't work in previous versions of libpng anyways
+  Optimized filter selection code
+  Fixed png_set_background() to allow using an arbitrary RGB color for
+    paletted images
+  Fixed gamma and background correction for paletted images, so
+    png_correct_palette is not needed unless you are correcting an
+    external palette (you will need to #define PNG_CORRECT_PALETTE_SUPPORTED
+    in pngconf.h) - if nobody uses this, it may disappear in the future.
+  Fixed bug with Borland 64K memory allocation (Alexander Lehmann)
+  Fixed bug in interlace handling (Smarasderagd, I think)
+  Added more error checking for writing and image to reduce invalid files
+  Separated read and write functions so that they won't both be linked
+    into a binary when only reading or writing functionality is used
+  New pngtest image also has interlacing and zTXt
+  Updated documentation to reflect new API
+Version 0.90 [January, 1997]
+  Made CRC errors/warnings on critical and ancillary chunks configurable
+  libpng will use the zlib CRC routines by (compile-time) default
+  Changed DOS small/medium model memory support - needs zlib 1.04 (Tim Wegner)
+  Added external C++ wrapper statements to png.h (Gilles Dauphin)
+  Allow PNG file to be read when some or all of file signature has already
+    been read from the beginning of the stream.  ****This affects the size
+    of info_struct and invalidates all programs that use a shared libpng****
+  Fixed png_filler() declarations
+  Fixed? background color conversions
+  Fixed order of error function pointers to match documentation
+  Current chunk name is now available in png_struct to reduce the number
+    of nearly identical error messages (will simplify multi-lingual
+    support when available)
+  Try to get ready for unknown-chunk callback functions:
+    - previously read critical chunks are flagged, so the chunk handling
+      routines can determine if the chunk is in the right place
+    - all chunk handling routines have the same prototypes, so we will
+      be able to handle all chunks via a callback mechanism
+  Try to fix Linux "setjmp" buffer size problems
+  Removed png_large_malloc, png_large_free, and png_realloc functions.
+Version 0.95 [March, 1997]
+  Fixed bug in pngwutil.c allocating "up_row" twice and "avg_row" never
+  Fixed bug in PNG file signature compares when start != 0
+  Changed parameter type of png_set_filler(...filler...) from png_byte
+    to png_uint_32
+  Added test for MACOS to ensure that both math.h and fp.h are not #included
+  Added macros for libpng to be compiled as a Windows DLL (Andreas Kupries)
+  Added "packswap" transformation, which changes the endianness of
+    packed-pixel bytes (Kevin Bracey)
+  Added "strip_alpha" transformation, which removes the alpha channel of
+    input images without using it (not necessarily a good idea)
+  Added "swap_alpha" transformation, which puts the alpha channel in front
+    of the color bytes instead of after
+  Removed all implicit variable tests which assume NULL == 0 (I think)
+  Changed several variables to "png_size_t" to show 16/32-bit limitations
+  Added new pCAL chunk read/write support
+  Added experimental filter selection weighting (Greg Roelofs)
+  Removed old png_set_rgbx() and png_set_xrgb() functions that have been
+     obsolete for about 2 years now (use png_set_filler() instead)
+  Added macros to read 16- and 32-bit ints directly from buffer, to be
+    used only on those systems that support it (namely PowerPC and 680x0)
+    With some testing, this may become the default for MACOS/PPC systems.
+  Only calculate CRC on data if we are going to use it
+  Added macros for zTXt compression type PNG_zTXt_COMPRESSION_???
+  Added macros for simple libpng debugging output selectable at compile time
+  Removed PNG_READ_END_MODE in progressive reader (Smarasderagd)
+  More description of info_struct in libpng.txt and png.h
+  More instructions in example.c
+  More chunk types tested in pngtest.c
+  Renamed pngrcb.c to pngset.c, and all png_read_<chunk> functions to be
+    png_set_<chunk>.  We now have corresponding png_get_<chunk>
+    functions in pngget.c to get information in info_ptr.  This isolates
+    the application from the internal organization of png_info_struct
+    (good for shared library implementations).
+Version 0.96 [May, 1997]
+  Fixed serious bug with < 8bpp images introduced in 0.95
+  Fixed 256-color transparency bug (Greg Roelofs)
+  Fixed up documentation (Greg Roelofs, Laszlo Nyul)
+  Fixed "error" in pngconf.h for Linux setjmp() behavior
+  Fixed DOS medium model support (Tim Wegner)
+  Fixed png_check_keyword() for case with error in static string text
+  Added read of CRC after IEND chunk for embedded PNGs (Laszlo Nyul)
+  Added typecasts to quiet compiler errors
+  Added more debugging info
+Version 0.97 [January, 1998]
+  Removed PNG_USE_OWN_CRC capability
+  Relocated png_set_crc_action from pngrutil.c to pngrtran.c
+  Fixed typecasts of "new_key", etc. (Andreas Dilger)
+  Added RFC 1152 [sic] date support
+  Fixed bug in gamma handling of 4-bit grayscale
+  Added 2-bit grayscale gamma handling (Glenn R-P)
+  Added more typecasts. 65536L becomes (png_uint_32)65536L, etc. (Glenn R-P)
+  Minor corrections in libpng.txt
+  Added simple sRGB support (Glenn R-P)
+  Easier conditional compiling, e.g.,
+    define PNG_READ/WRITE_NOT_FULLY_SUPPORTED;
+    all configurable options can be selected from command-line instead
+    of having to edit pngconf.h (Glenn R-P)
+  Fixed memory leak in pngwrite.c (free info_ptr->text) (Glenn R-P)
+  Added more conditions for png_do_background, to avoid changing
+    black pixels to background when a background is supplied and
+    no pixels are transparent
+  Repaired PNG_NO_STDIO behavior
+  Tested NODIV support and made it default behavior (Greg Roelofs)
+  Added "-m" option and PNGTEST_DEBUG_MEMORY to pngtest (John Bowler)
+  Regularized version numbering scheme and bumped shared-library major
+    version number to 2 to avoid problems with libpng 0.89 apps
+    (Greg Roelofs)
+Version 0.98 [January, 1998]
+  Cleaned up some typos in libpng.txt and in code documentation
+  Fixed memory leaks in pCAL chunk processing (Glenn R-P and John Bowler)
+  Cosmetic change "display_gamma" to "screen_gamma" in pngrtran.c
+  Changed recommendation about file_gamma for PC images to .51 from .45,
+    in example.c and libpng.txt, added comments to distinguish between
+    screen_gamma, viewing_gamma, and display_gamma.
+  Changed all references to RFC1152 to read RFC1123 and changed the
+    PNG_TIME_RFC1152_SUPPORTED macro to PNG_TIME_RFC1123_SUPPORTED
+  Added png_invert_alpha capability (Glenn R-P -- suggestion by Jon Vincent)
+  Changed srgb_intent from png_byte to int to avoid compiler bugs
+Version 0.99 [January 30, 1998]
+  Free info_ptr->text instead of end_info_ptr->text in pngread.c (John Bowler)
+  Fixed a longstanding "packswap" bug in pngtrans.c
+  Fixed some inconsistencies in pngconf.h that prevented compiling with
+    PNG_READ_GAMMA_SUPPORTED and PNG_READ_hIST_SUPPORTED undefined
+  Fixed some typos and made other minor rearrangement of libpng.txt (Andreas)
+  Changed recommendation about file_gamma for PC images to .50 from .51 in
+    example.c and libpng.txt, and changed file_gamma for sRGB images to .45
+  Added a number of functions to access information from the png structure
+    png_get_image_height(), etc. (Glenn R-P, suggestion by Brad Pettit)
+  Added TARGET_MACOS similar to zlib-1.0.8
+  Define PNG_ALWAYS_EXTERN when __MWERKS__ && WIN32 are defined
+  Added type casting to all png_malloc() function calls
+Version 0.99a [January 31, 1998]
+  Added type casts and parentheses to all returns that return a value.(Tim W.)
+Version 0.99b [February 4, 1998]
+  Added type cast png_uint_32 on malloc function calls where needed.
+  Changed type of num_hist from png_uint_32 to int (same as num_palette).
+  Added checks for rowbytes overflow, in case png_size_t is less than 32 bits.
+  Renamed makefile.elf to makefile.lnx.
+Version 0.99c [February 7, 1998]
+  More type casting.  Removed erroneous overflow test in pngmem.c.
+  Added png_buffered_memcpy() and png_buffered_memset(), apply them to rowbytes.
+  Added UNIX manual pages libpng.3 (incorporating libpng.txt) and  png.5.
+Version 0.99d [February 11, 1998]
+  Renamed "far_to_near()" "png_far_to_near()"
+  Revised libpng.3
+  Version 99c "buffered" operations didn't work as intended.  Replaced them
+    with png_memcpy_check() and png_memset_check().
+  Added many "if (png_ptr == NULL) return" to quell compiler warnings about
+    unused png_ptr, mostly in pngget.c and pngset.c.
+  Check for overlength tRNS chunk present when indexed-color PLTE is read.
+  Cleaned up spelling errors in libpng.3/libpng.txt
+  Corrected a problem with png_get_tRNS() which returned undefined trans array
+Version 0.99e [February 28, 1998]
+  Corrected png_get_tRNS() again.
+  Add parentheses for easier reading of pngget.c, fixed "||" should be "&&".
+  Touched up example.c to make more of it compileable, although the entire
+    file still can't be compiled (Willem van Schaik)
+  Fixed a bug in png_do_shift() (Bryan Tsai)
+  Added a space in png.h prototype for png_write_chunk_start()
+  Replaced pngtest.png with one created with zlib 1.1.1
+  Changed pngtest to report PASS even when file size is different (Jean-loup G.)
+  Corrected some logic errors in png_do_invert_alpha() (Chris Patterson)
+Version 0.99f [March 5, 1998]
+  Corrected a bug in pngpread() introduced in version 99c (Kevin Bracey)
+  Moved makefiles into a "scripts" directory, and added INSTALL instruction file
+  Added makefile.os2 and pngos2.def (A. Zabolotny) and makefile.s2x (W. Sebok)
+  Added pointers to "note on libpng versions" in makefile.lnx and README
+  Added row callback feature when reading and writing nonprogressive rows
+    and added a test of this feature in pngtest.c
+  Added user transform callbacks, with test of the feature in pngtest.c
+Version 0.99g [March 6, 1998, morning]
+  Minor changes to pngtest.c to suppress compiler warnings.
+  Removed "beta" language from documentation.
+Version 0.99h [March 6, 1998, evening]
+  Minor changes to previous minor changes to pngtest.c
+  Changed PNG_READ_NOT_FULLY_SUPPORTED to PNG_READ_TRANSFORMS_NOT_SUPPORTED
+    and added PNG_PROGRESSIVE_READ_NOT_SUPPORTED macro
+  Added user transform capability
+Version 1.00 [March 7, 1998]
+  Changed several typedefs in pngrutil.c
+  Added makefile.wat (Pawel Mrochen), updated makefile.tc3 (Willem van Schaik)
+  Replaced "while(1)" with "for(;;)"
+  Added PNGARG() to prototypes in pngtest.c and removed some prototypes
+  Updated some of the makefiles (Tom Lane)
+  Changed some typedefs (s_start, etc.) in pngrutil.c
+  Fixed dimensions of "short_months" array in pngwrite.c
+  Replaced ansi2knr.c with the one from jpeg-v6
+Version 1.0.0 [March 8, 1998]
+  Changed name from 1.00 to 1.0.0 (Adam Costello)
+  Added smakefile.ppc (with SCOPTIONS.ppc) for Amiga PPC (Andreas Kleinert)
+Version 1.0.0a [March 9, 1998]
+  Fixed three bugs in pngrtran.c to make gamma+background handling consistent
+    (Greg Roelofs)
+  Changed format of the PNG_LIBPNG_VER integer to xyyzz instead of xyz
+    for major, minor, and bugfix releases.  This is 10001. (Adam Costello,
+    Tom Lane)
+  Make months range from 1-12 in png_convert_to_rfc1123
+Version 1.0.0b [March 13, 1998]
+  Quieted compiler complaints about two empty "for" loops in pngrutil.c
+  Minor changes to makefile.s2x
+  Removed #ifdef/#endif around a png_free() in pngread.c
+Version 1.0.1 [March 14, 1998]
+  Changed makefile.s2x to reduce security risk of using a relative pathname
+  Fixed some typos in the documentation (Greg).
+  Fixed a problem with value of "channels" returned by png_read_update_info()
+Version 1.0.1a [April 21, 1998]
+  Optimized Paeth calculations by replacing abs() function calls with intrinsics
+  plus other loop optimizations. Improves avg decoding speed by about 20%.
+  Commented out i386istic "align" compiler flags in makefile.lnx.
+  Reduced the default warning level in some makefiles, to make them consistent.
+  Removed references to IJG and JPEG in the ansi2knr.c copyright statement.
+  Fixed a bug in png_do_strip_filler with XXRRGGBB => RRGGBB transformation.
+  Added grayscale and 16-bit capability to png_do_read_filler().
+  Fixed a bug in pngset.c, introduced in version 0.99c, that sets rowbytes
+    too large when writing an image with bit_depth < 8 (Bob Dellaca).
+  Corrected some bugs in the experimental weighted filtering heuristics.
+  Moved a misplaced pngrutil code block that truncates tRNS if it has more
+    than num_palette entries -- test was done before num_palette was defined.
+  Fixed a png_convert_to_rfc1123() bug that converts day 31 to 0 (Steve Eddins).
+  Changed compiler flags in makefile.wat for better optimization
+    (Pawel Mrochen).
+Version 1.0.1b [May 2, 1998]
+  Relocated png_do_gray_to_rgb() within png_do_read_transformations() (Greg).
+  Relocated the png_composite macros from pngrtran.c to png.h (Greg).
+  Added makefile.sco (contributed by Mike Hopkirk).
+  Fixed two bugs (missing definitions of "istop") introduced in libpng-1.0.1a.
+  Fixed a bug in pngrtran.c that would set channels=5 under some circumstances.
+  More work on the Paeth-filtering, achieving imperceptible speedup
+    (A Kleinert).
+  More work on loop optimization which may help when compiled with C++
+    compilers.
+  Added warnings when people try to use transforms they've defined out.
+  Collapsed 4 "i" and "c" loops into single "i" loops in pngrtran and pngwtran.
+  Revised paragraph about png_set_expand() in libpng.txt and libpng.3 (Greg)
+Version 1.0.1c [May 11, 1998]
+  Fixed a bug in pngrtran.c (introduced in libpng-1.0.1a) where the masks for
+    filler bytes should have been 0xff instead of 0xf.
+  Added max_pixel_depth=32 in pngrutil.c when using FILLER with palette images.
+  Moved PNG_WRITE_WEIGHTED_FILTER_SUPPORTED and PNG_WRITE_FLUSH_SUPPORTED
+    out of the PNG_WRITE_TRANSFORMS_NOT_SUPPORTED block of pngconf.h
+  Added "PNG_NO_WRITE_TRANSFORMS" etc., as alternatives for *_NOT_SUPPORTED,
+    for consistency, in pngconf.h
+  Added individual "ifndef PNG_NO_[CAPABILITY]" in pngconf.h to make it easier
+    to remove unwanted capabilities via the compile line
+  Made some corrections to grammar (which, it's) in documentation (Greg).
+  Corrected example.c, use of row_pointers in png_write_image().
+Version 1.0.1d [May 24, 1998]
+  Corrected several statements that used side effects illegally in pngrutil.c
+    and pngtrans.c, that were introduced in version 1.0.1b
+  Revised png_read_rows() to avoid repeated if-testing for NULL (A Kleinert)
+  More corrections to example.c, use of row_pointers in png_write_image()
+    and png_read_rows().
+  Added pngdll.mak and pngdef.pas to scripts directory, contributed by
+    Bob Dellaca, to make a png32bd.dll with Borland C++ 4.5
+  Fixed error in example.c with png_set_text: num_text is 3, not 2 (Guido V.)
+  Changed several loops from count-down to count-up, for consistency.
+Version 1.0.1e [June 6, 1998]
+  Revised libpng.txt and libpng.3 description of png_set_read|write_fn(), and
+    added warnings when people try to set png_read_fn and png_write_fn in
+    the same structure.
+  Added a test such that png_do_gamma will be done when num_trans==0
+    for truecolor images that have defined a background.  This corrects an
+    error that was introduced in libpng-0.90 that can cause gamma processing
+    to be skipped.
+  Added tests in png.h to include "trans" and "trans_values" in structures
+    when PNG_READ_BACKGROUND_SUPPORTED or PNG_READ_EXPAND_SUPPORTED is defined.
+  Add png_free(png_ptr->time_buffer) in png_destroy_read_struct()
+  Moved png_convert_to_rfc_1123() from pngwrite.c to png.c
+  Added capability for user-provided malloc_fn() and free_fn() functions,
+    and revised pngtest.c to demonstrate their use, replacing the
+    PNGTEST_DEBUG_MEM feature.
+  Added makefile.w32, for Microsoft C++ 4.0 and later (Tim Wegner).
+Version 1.0.2 [June 14, 1998]
+  Fixed two bugs in makefile.bor .
+Version 1.0.2a [December 30, 1998]
+  Replaced and extended code that was removed from png_set_filler() in 1.0.1a.
+  Fixed a bug in png_do_filler() that made it fail to write filler bytes in
+    the left-most pixel of each row (Kevin Bracey).
+  Changed "static pngcharp tIME_string" to "static char tIME_string[30]"
+    in pngtest.c (Duncan Simpson).
+  Fixed a bug in pngtest.c that caused pngtest to try to write a tIME chunk
+    even when no tIME chunk was present in the source file.
+  Fixed a problem in pngrutil.c: gray_to_rgb didn't always work with 16-bit.
+  Fixed a problem in png_read_push_finish_row(), which would not skip some
+    passes that it should skip, for images that are less than 3 pixels high.
+  Interchanged the order of calls to png_do_swap() and png_do_shift()
+    in pngwtran.c (John Cromer).
+  Added #ifdef PNG_DEBUG/#endif surrounding use of PNG_DEBUG in png.h .
+  Changed "bad adaptive filter type" from error to warning in pngrutil.c .
+  Fixed a documentation error about default filtering with 8-bit indexed-color.
+  Separated the PNG_NO_STDIO macro into PNG_NO_STDIO and PNG_NO_CONSOLE_IO
+    (L. Peter Deutsch).
+  Added png_set_rgb_to_gray() and png_get_rgb_to_gray_status() functions.
+  Added png_get_copyright() and png_get_header_version() functions.
+  Revised comments on png_set_progressive_read_fn() in libpng.txt and example.c
+  Added information about debugging in libpng.txt and libpng.3 .
+  Changed "ln -sf" to "ln -s -f" in makefile.s2x, makefile.lnx, and
+    makefile.sco.
+  Removed lines after Dynamic Dependencies" in makefile.aco .
+  Revised makefile.dec to make a shared library (Jeremie Petit).
+  Removed trailing blanks from all files.
+Version 1.0.2a [January 6, 1999]
+  Removed misplaced #endif and #ifdef PNG_NO_EXTERN near the end of png.h
+  Added "if" tests to silence complaints about unused png_ptr in png.h and png.c
+  Changed "check_if_png" function in example.c to return true (nonzero) if PNG.
+  Changed libpng.txt to demonstrate png_sig_cmp() instead of png_check_sig()
+    which is obsolete.
+Version 1.0.3 [January 14, 1999]
+  Added makefile.hux, for Hewlett Packard HPUX 10.20 and 11.00 (Jim Rice)
+  Added a statement of Y2K compliance in png.h, libpng.3, and Y2KINFO.
+Version 1.0.3a [August 12, 1999]
+  Added check for PNG_READ_INTERLACE_SUPPORTED in pngread.c; issue a warning
+     if an attempt is made to read an interlaced image when it's not supported.
+  Added check if png_ptr->trans is defined before freeing it in pngread.c
+  Modified the Y2K statement to include versions back to version 0.71
+  Fixed a bug in the check for valid IHDR bit_depth/color_types in pngrutil.c
+  Modified makefile.wat (added -zp8 flag, ".symbolic", changed some comments)
+  Replaced leading blanks with tab characters in makefile.hux
+  Changed "dworkin.wustl.edu" to "ccrc.wustl.edu" in various documents.
+  Changed (float)red and (float)green to (double)red, (double)green
+     in png_set_rgb_to_gray() to avoid "promotion" problems in AIX.
+  Fixed a bug in pngconf.h that omitted <stdio.h> when PNG_DEBUG==0 (K Bracey).
+  Reformatted libpng.3 and libpngpf.3 with proper fonts (script by J. vanZandt).
+  Updated documentation to refer to the PNG-1.2 specification.
+  Removed ansi2knr.c and left pointers to the latest source for ansi2knr.c
+    in makefile.knr, INSTALL, and README (L. Peter Deutsch)
+  Fixed bugs in calculation of the length of rowbytes when adding alpha
+    channels to 16-bit images, in pngrtran.c (Chris Nokleberg)
+  Added function png_set_user_transform_info() to store user_transform_ptr,
+    user_depth, and user_channels into the png_struct, and a function
+    png_get_user_transform_ptr() to retrieve the pointer (Chris Nokleberg)
+  Added function png_set_empty_plte_permitted() to make libpng useable
+    in MNG applications.
+  Corrected the typedef for png_free_ptr in png.h (Jesse Jones).
+  Correct gamma with srgb is 45455 instead of 45000 in pngrutil.c, to be
+    consistent with PNG-1.2, and allow variance of 500 before complaining.
+  Added assembler code contributed by Intel in file pngvcrd.c and modified
+    makefile.w32 to use it (Nirav Chhatrapati, INTEL Corporation,
+    Gilles Vollant)
+  Changed "ln -s -f" to "ln -f -s" in the makefiles to make Solaris happy.
+  Added some aliases for png_set_expand() in pngrtran.c, namely
+    png_set_expand_PLTE(), png_set_expand_depth(), and png_set_expand_tRNS()
+    (Greg Roelofs, in "PNG: The Definitive Guide").
+  Added makefile.beo for BEOS on X86, contributed by Sander Stok.
+Version 1.0.3b [August 26, 1999]
+  Replaced 2147483647L several places with PNG_MAX_UINT macro, defined in png.h
+  Changed leading blanks to tabs in all makefiles.
+  Define PNG_USE_PNGVCRD in makefile.w32, to get MMX assembler code.
+  Made alternate versions of  png_set_expand() in pngrtran.c, namely
+    png_set_gray_1_2_4_to_8, png_set_palette_to_rgb, and png_set_tRNS_to_alpha
+    (Greg Roelofs, in "PNG: The Definitive Guide").  Deleted the 1.0.3a aliases.
+  Relocated start of 'extern "C"' block in png.h so it doesn't include pngconf.h
+  Revised calculation of num_blocks in pngmem.c to avoid a potentially
+    negative shift distance, whose results are undefined in the C language.
+  Added a check in pngset.c to prevent writing multiple tIME chunks.
+  Added a check in pngwrite.c to detect invalid small window_bits sizes.
+Version 1.0.3d [September 4, 1999]
+  Fixed type casting of igamma in pngrutil.c
+  Added new png_expand functions to scripts/pngdef.pas and pngos2.def
+  Added a demo read_user_transform_fn that examines the row filters in pngtest.c
+Version 1.0.4 [September 24, 1999]
+  Define PNG_ALWAYS_EXTERN in pngconf.h if __STDC__ is defined
+  Delete #define PNG_INTERNAL and include "png.h" from pngasmrd.h
+  Made several minor corrections to pngtest.c
+  Renamed the makefiles with longer but more user friendly extensions.
+  Copied the PNG copyright and license to a separate LICENSE file.
+  Revised documentation, png.h, and example.c to remove reference to
+    "viewing_gamma" which no longer appears in the PNG specification.
+  Revised pngvcrd.c to use MMX code for interlacing only on the final pass.
+  Updated pngvcrd.c to use the faster C filter algorithms from libpng-1.0.1a
+  Split makefile.win32vc into two versions, makefile.vcawin32 (uses MMX
+    assembler code) and makefile.vcwin32 (doesn't).
+  Added a CPU timing report to pngtest.c (enabled by defining PNGTEST_TIMING)
+  Added a copy of pngnow.png to the distribution.
+Version 1.0.4a [September 25, 1999]
+  Increase max_pixel_depth in pngrutil.c if a user transform needs it.
+  Changed several division operations to right-shifts in pngvcrd.c
+Version 1.0.4b [September 30, 1999]
+  Added parentheses in line 3732 of pngvcrd.c
+  Added a comment in makefile.linux warning about buggy -O3 in pgcc 2.95.1
+Version 1.0.4c [October 1, 1999]
+  Added a "png_check_version" function in png.c and pngtest.c that will generate
+    a helpful compiler error if an old png.h is found in the search path.
+  Changed type of png_user_transform_depth|channels from int to png_byte.
+Version 1.0.4d [October 6, 1999]
+  Changed 0.45 to 0.45455 in png_set_sRGB()
+  Removed unused PLTE entries from pngnow.png
+  Re-enabled some parts of pngvcrd.c (png_combine_row) that work properly.
+Version 1.0.4e [October 10, 1999]
+  Fixed sign error in pngvcrd.c (Greg Roelofs)
+  Replaced some instances of memcpy with simple assignments in pngvcrd (GR-P)
+Version 1.0.4f [October 15, 1999]
+  Surrounded example.c code with #if 0 .. #endif to prevent people from
+    inadvertently trying to compile it.
+  Changed png_get_header_version() from a function to a macro in png.h
+  Added type casting mostly in pngrtran.c and pngwtran.c
+  Removed some pointless "ptr = NULL" in pngmem.c
+  Added a "contrib" directory containing the source code from Greg's book.
+Version 1.0.5 [October 15, 1999]
+  Minor editing of the INSTALL and README files.
+Version 1.0.5a [October 23, 1999]
+  Added contrib/pngsuite and contrib/pngminus (Willem van Schaik)
+  Fixed a typo in the png_set_sRGB() function call in example.c (Jan Nijtmans)
+  Further optimization and bugfix of pngvcrd.c
+  Revised pngset.c so that it does not allocate or free memory in the user's
+    text_ptr structure.  Instead, it makes its own copy.
+  Created separate write_end_info_struct in pngtest.c for a more severe test.
+  Added code in pngwrite.c to free info_ptr->text[i].key to stop a memory leak.
+Version 1.0.5b [November 23, 1999]
+  Moved PNG_FLAG_HAVE_CHUNK_HEADER, PNG_FLAG_BACKGROUND_IS_GRAY and
+    PNG_FLAG_WROTE_tIME from flags to mode.
+  Added png_write_info_before_PLTE() function.
+  Fixed some typecasting in contrib/gregbook/*.c
+  Updated scripts/makevms.com and added makevms.com to contrib/gregbook
+    and contrib/pngminus (Martin Zinser)
+Version 1.0.5c [November 26, 1999]
+  Moved png_get_header_version from png.h to png.c, to accommodate ansi2knr.
+  Removed all global arrays (according to PNG_NO_GLOBAL_ARRAYS macro), to
+    accommodate making DLL's: Moved usr_png_ver from global variable to function
+    png_get_header_ver() in png.c.  Moved png_sig to png_sig_bytes in png.c and
+    eliminated use of png_sig in pngwutil.c.  Moved the various png_CHNK arrays
+    into pngtypes.h.  Eliminated use of global png_pass arrays.  Declared the
+    png_CHNK and png_pass arrays to be "const".  Made the global arrays
+    available to applications (although none are used in libpng itself) when
+    PNG_NO_GLOBAL_ARRAYS is not defined or when PNG_GLOBAL_ARRAYS is defined.
+  Removed some extraneous "-I" from contrib/pngminus/makefile.std
+  Changed the PNG_sRGB_INTENT macros in png.h to be consistent with PNG-1.2.
+  Change PNG_SRGB_INTENT to PNG_sRGB_INTENT in libpng.txt and libpng.3
+Version 1.0.5d [November 29, 1999]
+  Add type cast (png_const_charp) two places in png.c
+  Eliminated pngtypes.h; use macros instead to declare PNG_CHNK arrays.
+  Renamed "PNG_GLOBAL_ARRAYS" to "PNG_USE_GLOBAL_ARRAYS" and made available
+    to applications a macro "PNG_USE_LOCAL_ARRAYS".
+  comment out (with #ifdef) all the new declarations when
+    PNG_USE_GLOBAL_ARRAYS is defined.
+  Added PNG_EXPORT_VAR macro to accommodate making DLL's.
+Version 1.0.5e [November 30, 1999]
+  Added iCCP, iTXt, and sPLT support; added "lang" member to the png_text
+    structure; refactored the inflate/deflate support to make adding new chunks
+    with trailing compressed parts easier in the future, and added new functions
+    png_free_iCCP, png_free_pCAL, png_free_sPLT, png_free_text, png_get_iCCP,
+    png_get_spalettes, png_set_iCCP, png_set_spalettes (Eric S. Raymond).
+  NOTE: Applications that write text chunks MUST define png_text->lang
+    before calling png_set_text(). It must be set to NULL if you want to
+    write tEXt or zTXt chunks.  If you want your application to be able to
+    run with older versions of libpng, use
+      #ifdef PNG_iTXt_SUPPORTED
+         png_text[i].lang = NULL;
+      #endif
+  Changed png_get_oFFs() and png_set_oFFs() to use signed rather than unsigned
+    offsets (Eric S. Raymond).
+  Combined PNG_READ_cHNK_SUPPORTED and PNG_WRITE_cHNK_SUPPORTED macros into
+    PNG_cHNK_SUPPORTED and combined the three types of PNG_text_SUPPORTED
+    macros, leaving the separate macros also available.
+  Removed comments on #endifs at the end of many short, non-nested #if-blocks.
+Version 1.0.5f [December 6, 1999]
+  Changed makefile.solaris to issue a warning about potential problems when
+    the ucb "ld" is in the path ahead of the ccs "ld".
+  Removed "- [date]" from the "synopsis" line in libpng.3 and libpngpf.3.
+  Added sCAL chunk support (Eric S. Raymond).
+Version 1.0.5g [December 7, 1999]
+  Fixed "png_free_spallettes" typo in png.h
+  Added code to handle new chunks in pngpread.c
+  Moved PNG_CHNK string macro definitions outside of PNG_NO_EXTERN block
+  Added "translated_key" to png_text structure and png_write_iTXt().
+  Added code in pngwrite.c to work around a newly discovered zlib bug.
+Version 1.0.5h [December 10, 1999]
+  NOTE: regarding the note for version 1.0.5e, the following must also
+    be included in your code:
+        png_text[i].translated_key = NULL;
+  Unknown chunk handling is now supported.
+  Option to eliminate all floating point support was added.  Some new
+    fixed-point functions such as png_set_gAMA_fixed() were added.
+  Expanded tabs and removed trailing blanks in source files.
+Version 1.0.5i [December 13, 1999]
+  Added some type casts to silence compiler warnings.
+  Renamed "png_free_spalette" to "png_free_spalettes" for consistency.
+  Removed leading blanks from a #define in pngvcrd.c
+  Added some parameters to the new png_set_keep_unknown_chunks() function.
+  Added a test for up->location != 0 in the first instance of writing
+    unknown chunks in pngwrite.c
+  Changed "num" to "i" in png_free_spalettes() and png_free_unknowns() to
+    prevent recursion.
+  Added png_free_hIST() function.
+  Various patches to fix bugs in the sCAL and integer cHRM processing,
+    and to add some convenience macros for use with sCAL.
+Version 1.0.5j [December 21, 1999]
+  Changed "unit" parameter of png_write_sCAL from png_byte to int, to work
+    around buggy compilers.
+  Added new type "png_fixed_point" for integers that hold float*100000 values
+  Restored backward compatibility of tEXt/zTXt chunk processing:
+    Restored the first four members of png_text to the same order as v.1.0.5d.
+    Added members "lang_key" and "itxt_length" to png_text struct.  Set
+    text_length=0 when "text" contains iTXt data.  Use the "compression"
+    member to distinguish among tEXt/zTXt/iTXt types.  Added
+    PNG_ITXT_COMPRESSION_NONE (1) and PNG_ITXT_COMPRESSION_zTXt(2) macros.
+    The "Note" above, about backward incompatibility of libpng-1.0.5e, no
+    longer applies.
+  Fixed png_read|write_iTXt() to read|write parameters in the right order,
+    and to write the iTXt chunk after IDAT if it appears in the end_ptr.
+  Added pnggccrd.c, version of pngvcrd.c Intel assembler for gcc (Greg Roelofs)
+  Reversed the order of trying to write floating-point and fixed-point gAMA.
+Version 1.0.5k [December 27, 1999]
+  Added many parentheses, e.g., "if (a && b & c)" becomes "if (a && (b & c))"
+  Added png_handle_as_unknown() function (Glenn)
+  Added png_free_chunk_list() function and chunk_list and num_chunk_list members
+    of png_ptr.
+  Eliminated erroneous warnings about multiple sPLT chunks and sPLT-after-PLTE.
+  Fixed a libpng-1.0.5h bug in pngrutil.c that was issuing erroneous warnings
+    about ignoring incorrect gAMA with sRGB (gAMA was in fact not ignored)
+  Added png_free_tRNS(); png_set_tRNS() now malloc's its own trans array (ESR).
+  Define png_get_int_32 when oFFs chunk is supported as well as when pCAL is.
+  Changed type of proflen from png_int_32 to png_uint_32 in png_get_iCCP().
+Version 1.0.5l [January 1, 2000]
+  Added functions png_set_read_user_chunk_fn() and png_get_user_chunk_ptr()
+    for setting a callback function to handle unknown chunks and for
+    retrieving the associated user pointer (Glenn).
+Version 1.0.5m [January 7, 2000]
+  Added high-level functions png_read_png(), png_write_png(), png_free_pixels().
+Version 1.0.5n [January 9, 2000]
+  Added png_free_PLTE() function, and modified png_set_PLTE() to malloc its
+    own memory for info_ptr->palette.  This makes it safe for the calling
+    application to free its copy of the palette any time after it calls
+    png_set_PLTE().
+Version 1.0.5o [January 20, 2000]
+  Cosmetic changes only (removed some trailing blanks and TABs)
+Version 1.0.5p [January 31, 2000]
+  Renamed pngdll.mak to makefile.bd32
+  Cosmetic changes in pngtest.c
+Version 1.0.5q [February 5, 2000]
+  Relocated the makefile.solaris warning about PATH problems.
+  Fixed pngvcrd.c bug by pushing/popping registers in mmxsupport (Bruce Oberg)
+  Revised makefile.gcmmx
+  Added PNG_SETJMP_SUPPORTED, PNG_SETJMP_NOT_SUPPORTED, and PNG_ABORT() macros
+Version 1.0.5r [February 7, 2000]
+  Removed superfluous prototype for png_get_itxt from png.h
+  Fixed a bug in pngrtran.c that improperly expanded the background color.
+  Return *num_text=0 from png_get_text() when appropriate, and fix documentation
+    of png_get_text() in libpng.txt/libpng.3.
+Version 1.0.5s [February 18, 2000]
+  Added "png_jmp_env()" macro to pngconf.h, to help people migrate to the
+    new error handler that's planned for the next libpng release, and changed
+    example.c, pngtest.c, and contrib programs to use this macro.
+  Revised some of the DLL-export macros in pngconf.h (Greg Roelofs)
+  Fixed a bug in png_read_png() that caused it to fail to expand some images
+    that it should have expanded.
+  Fixed some mistakes in the unused and undocumented INCH_CONVERSIONS functions
+    in pngget.c
+  Changed the allocation of palette, history, and trans arrays back to
+    the version 1.0.5 method (linking instead of copying) which restores
+    backward compatibility with version 1.0.5.  Added some remarks about
+    that in example.c.  Added "free_me" member to info_ptr and png_ptr
+    and added png_free_data() function.
+  Updated makefile.linux and makefile.gccmmx to make directories conditionally.
+  Made cosmetic changes to pngasmrd.h
+  Added png_set_rows() and png_get_rows(), for use with png_read|write_png().
+  Modified png_read_png() to allocate info_ptr->row_pointers only if it
+    hasn't already been allocated.
+Version 1.0.5t [March 4, 2000]
+  Changed png_jmp_env() migration aiding macro to png_jmpbuf().
+  Fixed "interlace" typo (should be "interlaced") in contrib/gregbook/read2-x.c
+  Fixed bug with use of PNG_BEFORE_IHDR bit in png_ptr->mode, introduced when
+    PNG_FLAG_HAVE_CHUNK_HEADER was moved into png_ptr->mode in version 1.0.5b
+  Files in contrib/gregbook were revised to use png_jmpbuf() and to select
+    a 24-bit visual if one is available, and to allow abbreviated options.
+  Files in contrib/pngminus were revised to use the png_jmpbuf() macro.
+  Removed spaces in makefile.linux and makefile.gcmmx, introduced in 1.0.5s
+Version 1.0.5u [March 5, 2000]
+  Simplified the code that detects old png.h in png.c and pngtest.c
+  Renamed png_spalette (_p, _pp) to png_sPLT_t (_tp, _tpp)
+  Increased precision of rgb_to_gray calculations from 8 to 15 bits and
+    added png_set_rgb_to_gray_fixed() function.
+  Added makefile.bc32 (32-bit Borland C++, C mode)
+Version 1.0.5v [March 11, 2000]
+  Added some parentheses to the png_jmpbuf macro definition.
+  Updated references to the zlib home page, which has moved to freesoftware.com.
+  Corrected bugs in documentation regarding png_read_row() and png_write_row().
+  Updated documentation of png_rgb_to_gray calculations in libpng.3/libpng.txt.
+  Renamed makefile.borland,turboc3 back to makefile.bor,tc3 as in version 1.0.3,
+    revised borland makefiles; added makefile.ibmvac3 and makefile.gcc (Cosmin)
+Version 1.0.6 [March 20, 2000]
+  Minor revisions of makefile.bor, libpng.txt, and gregbook/rpng2-win.c
+  Added makefile.sggcc (SGI IRIX with gcc)
+Version 1.0.6d [April 7, 2000]
+  Changed sprintf() to strcpy() in png_write_sCAL_s() to work without STDIO
+  Added data_length parameter to png_decompress_chunk() function
+  Revised documentation to remove reference to abandoned png_free_chnk functions
+  Fixed an error in png_rgb_to_gray_fixed()
+  Revised example.c, usage of png_destroy_write_struct().
+  Renamed makefile.ibmvac3 to makefile.ibmc, added libpng.icc IBM project file
+  Added a check for info_ptr->free_me&PNG_FREE_TEXT when freeing text in png.c
+  Simplify png_sig_bytes() function to remove use of non-ISO-C strdup().
+Version 1.0.6e [April 9, 2000]
+  Added png_data_freer() function.
+  In the code that checks for over-length tRNS chunks, added check of
+    info_ptr->num_trans as well as png_ptr->num_trans (Matthias Benckmann)
+  Minor revisions of libpng.txt/libpng.3.
+  Check for existing data and free it if the free_me flag is set, in png_set_*()
+    and png_handle_*().
+  Only define PNG_WEIGHTED_FILTERS_SUPPORTED when PNG_FLOATING_POINT_SUPPORTED
+    is defined.
+  Changed several instances of PNG_NO_CONSOLE_ID to PNG_NO_STDIO in pngrutil.c
+    and mentioned the purposes of the two macros in libpng.txt/libpng.3.
+Version 1.0.6f [April 14, 2000]
+  Revised png_set_iCCP() and png_set_rows() to avoid prematurely freeing data.
+  Add checks in png_set_text() for NULL members of the input text structure.
+  Revised libpng.txt/libpng.3.
+  Removed superfluous prototype for png_set_iTXt from png.h
+  Removed "else" from pngread.c, after png_error(), and changed "0" to "length".
+  Changed several png_errors about malformed ancillary chunks to png_warnings.
+Version 1.0.6g [April 24, 2000]
+  Added png_pass-* arrays to pnggccrd.c when PNG_USE_LOCAL_ARRAYS is defined.
+  Relocated paragraph about png_set_background() in libpng.3/libpng.txt
+    and other revisions (Matthias Benckmann)
+  Relocated info_ptr->free_me, png_ptr->free_me, and other info_ptr and
+    png_ptr members to restore binary compatibility with libpng-1.0.5
+    (breaks compatibility with libpng-1.0.6).
+Version 1.0.6h [April 24, 2000]
+  Changed shared library so-number pattern from 2.x.y.z to xy.z (this builds
+    libpng.so.10 & libpng.so.10.6h instead of libpng.so.2 & libpng.so.2.1.0.6h)
+    This is a temporary change for test purposes.
+Version 1.0.6i [May 2, 2000]
+  Rearranged some members at the end of png_info and png_struct, to put
+    unknown_chunks_num and free_me within the original size of the png_structs
+    and free_me, png_read_user_fn, and png_free_fn within the original png_info,
+    because some old applications allocate the structs directly instead of
+    using png_create_*().
+  Added documentation of user memory functions in libpng.txt/libpng.3
+  Modified png_read_png so that it will use user_allocated row_pointers
+    if present, unless free_me directs that it be freed, and added description
+    of the use of png_set_rows() and png_get_rows() in libpng.txt/libpng.3.
+  Added PNG_LEGACY_SUPPORTED macro, and #ifdef out all new (since version
+    1.00) members of png_struct and png_info, to regain binary compatibility
+    when you define this macro.  Capabilities lost in this event
+    are user transforms (new in version 1.0.0),the user transform pointer
+    (new in version 1.0.2), rgb_to_gray (new in 1.0.5), iCCP, sCAL, sPLT,
+    the high-level interface, and unknown chunks support (all new in 1.0.6).
+    This was necessary because of old applications that allocate the structs
+    directly as authors were instructed to do in libpng-0.88 and earlier,
+    instead of using png_create_*().
+  Added modes PNG_CREATED_READ_STRUCT and PNG_CREATED_WRITE_STRUCT which
+    can be used to detect codes that directly allocate the structs, and
+    code to check these modes in png_read_init() and png_write_init() and
+    generate a libpng error if the modes aren't set and PNG_LEGACY_SUPPORTED
+    was not defined.
+  Added makefile.intel and updated makefile.watcom (Pawel Mrochen)
+Version 1.0.6j [May 3, 2000]
+  Overloaded png_read_init() and png_write_init() with macros that convert
+    calls to png_read_init_2() or png_write_init_2() that check the version
+    and structure sizes.
+Version 1.0.7beta11 [May 7, 2000]
+  Removed the new PNG_CREATED_READ_STRUCT and PNG_CREATED_WRITE_STRUCT modes
+    which are no longer used.
+  Eliminated the three new members of png_text when PNG_LEGACY_SUPPORTED is
+    defined or when neither PNG_READ_iTXt_SUPPORTED nor PNG_WRITE_iTXT_SUPPORTED
+    is defined.
+  Made PNG_NO_READ|WRITE_iTXt the default setting, to avoid memory
+    overrun when old applications fill the info_ptr->text structure directly.
+  Added PNGAPI macro, and added it to the definitions of all exported functions.
+  Relocated version macro definitions ahead of the includes of zlib.h and
+    pngconf.h in png.h.
+Version 1.0.7beta12 [May 12, 2000]
+  Revised pngset.c to avoid a problem with expanding the png_debug macro.
+  Deleted some extraneous defines from pngconf.h
+  Made PNG_NO_CONSOLE_IO the default condition when PNG_BUILD_DLL is defined.
+  Use MSC _RPTn debugging instead of fprintf if _MSC_VER is defined.
+  Added png_access_version_number() function.
+  Check for mask&PNG_FREE_CHNK (for TEXT, SCAL, PCAL) in png_free_data().
+  Expanded libpng.3/libpng.txt information about png_data_freer().
+Version 1.0.7beta14 [May 17, 2000] (beta13 was not published)
+  Changed pnggccrd.c and pngvcrd.c to handle bad adaptive filter types as
+    warnings instead of errors, as pngrutil.c does.
+  Set the PNG_INFO_IDAT valid flag in png_set_rows() so png_write_png()
+    will actually write IDATs.
+  Made the default PNG_USE_LOCAL_ARRAYS depend on PNG_DLL instead of WIN32.
+  Make png_free_data() ignore its final parameter except when freeing data
+    that can have multiple instances (text, sPLT, unknowns).
+  Fixed a new bug in png_set_rows().
+  Removed info_ptr->valid tests from png_free_data(), as in version 1.0.5.
+  Added png_set_invalid() function.
+  Fixed incorrect illustrations of png_destroy_write_struct() in example.c.
+Version 1.0.7beta15 [May 30, 2000]
+  Revised the deliberately erroneous Linux setjmp code in pngconf.h to produce
+    fewer error messages.
+  Rearranged checks for Z_OK to check the most likely path first in pngpread.c
+    and pngwutil.c.
+  Added checks in pngtest.c for png_create_*() returning NULL, and mentioned
+    in libpng.txt/libpng.3 the need for applications to check this.
+  Changed names of png_default_*() functions in pngtest to pngtest_*().
+  Changed return type of png_get_x|y_offset_*() from png_uint_32 to png_int_32.
+  Fixed some bugs in the unused PNG_INCH_CONVERSIONS functions in pngget.c
+  Set each pointer to NULL after freeing it in png_free_data().
+  Worked around a problem in pngconf.h; AIX's strings.h defines an "index"
+    macro that conflicts with libpng's png_color_16.index. (Dimitri
+    Papadapoulos)
+  Added "msvc" directory with MSVC++ project files (Simon-Pierre Cadieux).
+Version 1.0.7beta16 [June 4, 2000]
+  Revised the workaround of AIX string.h "index" bug.
+  Added a check for overlength PLTE chunk in pngrutil.c.
+  Added PNG_NO_POINTER_INDEXING macro to use array-indexing instead of pointer
+    indexing in pngrutil.c and pngwutil.c to accommodate a buggy compiler.
+  Added a warning in png_decompress_chunk() when it runs out of data, e.g.
+    when it tries to read an erroneous PhotoShop iCCP chunk.
+  Added PNG_USE_DLL macro.
+  Revised the copyright/disclaimer/license notice.
+  Added contrib/msvctest directory
+Version 1.0.7rc1 [June 9, 2000]
+  Corrected the definition of PNG_TRANSFORM_INVERT_ALPHA  (0x0400 not 0x0200)
+  Added contrib/visupng directory (Willem van Schaik)
+Version 1.0.7beta18 [June 23, 2000]
+  Revised PNGAPI definition, and pngvcrd.c to work with __GCC__
+    and do not redefine PNGAPI if it is passed in via a compiler directive.
+  Revised visupng/PngFile.c to remove returns from within the Try block.
+  Removed leading underscores from "_PNG_H" and "_PNG_SAVE_BSD_SOURCE" macros.
+  Updated contrib/visupng/cexcept.h to version 1.0.0.
+  Fixed bugs in pngwrite.c and pngwutil.c that prevented writing iCCP chunks.
+Version 1.0.7rc2 [June 28, 2000]
+  Updated license to include disclaimers required by UCITA.
+  Fixed "DJBPP" typo in pnggccrd.c introduced in beta18.
+Version 1.0.7 [July 1, 2000]
+  Revised the definition of "trans_values" in libpng.3/libpng.txt
+Version 1.0.8beta1 [July 8, 2000]
+  Added png_free(png_ptr, key) two places in pngpread.c to stop memory leaks.
+  Changed PNG_NO_STDIO to PNG_NO_CONSOLE_IO, several places in pngrutil.c and
+     pngwutil.c.
+  Changed PNG_EXPORT_VAR to use PNG_IMPEXP, in pngconf.h.
+  Removed unused "#include <assert.h>" from png.c
+  Added WindowsCE support.
+  Revised pnggccrd.c to work with gcc-2.95.2 and in the Cygwin environment.
+Version 1.0.8beta2 [July 10, 2000]
+  Added project files to the wince directory and made further revisions
+     of pngtest.c, pngrio.c, and pngwio.c in support of WindowsCE.
+Version 1.0.8beta3 [July 11, 2000]
+  Only set the PNG_FLAG_FREE_TRNS or PNG_FREE_TRNS flag in png_handle_tRNS()
+     for indexed-color input files to avoid potential double-freeing trans array
+     under some unusual conditions; problem was introduced in version 1.0.6f.
+  Further revisions to pngtest.c and files in the wince subdirectory.
+Version 1.0.8beta4 [July 14, 2000]
+  Added the files pngbar.png and pngbar.jpg to the distribution.
+  Added makefile.cygwin, and cygwin support in pngconf.h
+  Added PNG_NO_ZALLOC_ZERO macro (makes png_zalloc skip zeroing memory)
+Version 1.0.8rc1 [July 16, 2000]
+  Revised png_debug() macros and statements to eliminate compiler warnings.
+Version 1.0.8 [July 24, 2000]
+  Added png_flush() in pngwrite.c, after png_write_IEND().
+  Updated makefile.hpux to build a shared library.
+Version 1.0.9beta1 [November 10, 2000]
+  Fixed typo in scripts/makefile.hpux
+  Updated makevms.com in scripts and contrib/* and contrib/* (Martin Zinser)
+  Fixed seqence-point bug in contrib/pngminus/png2pnm (Martin Zinser)
+  Changed "cdrom.com" in documentation to "libpng.org"
+  Revised pnggccrd.c to get it all working, and updated makefile.gcmmx (Greg).
+  Changed type of "params" from voidp to png_voidp in png_read|write_png().
+  Make sure PNGAPI and PNG_IMPEXP are defined in pngconf.h.
+  Revised the 3 instances of WRITEFILE in pngtest.c.
+  Relocated "msvc" and "wince" project subdirectories into "dll" subdirectory.
+  Updated png.rc in dll/msvc project
+  Revised makefile.dec to define and use LIBPATH and INCPATH
+  Increased size of global png_libpng_ver[] array from 12 to 18 chars.
+  Made global png_libpng_ver[], png_sig[] and png_pass_*[] arrays const.
+  Removed duplicate png_crc_finish() from png_handle_bKGD() function.
+  Added a warning when application calls png_read_update_info() multiple times.
+  Revised makefile.cygwin
+  Fixed bugs in iCCP support in pngrutil.c and pngwutil.c.
+  Replaced png_set_empty_plte_permitted() with png_permit_mng_features().
+Version 1.0.9beta2 [November 19, 2000]
+  Renamed the "dll" subdirectory "projects".
+  Added borland project files to "projects" subdirectory.
+  Set VS_FF_PRERELEASE and VS_FF_PATCHED flags in msvc/png.rc when appropriate.
+  Add error message in png_set_compression_buffer_size() when malloc fails.
+Version 1.0.9beta3 [November 23, 2000]
+  Revised PNG_LIBPNG_BUILD_TYPE macro in png.h, used in the msvc project.
+  Removed the png_flush() in pngwrite.c that crashes some applications
+    that don't set png_output_flush_fn.
+  Added makefile.macosx and makefile.aix to scripts directory.
+Version 1.0.9beta4 [December 1, 2000]
+  Change png_chunk_warning to png_warning in png_check_keyword().
+  Increased the first part of msg buffer from 16 to 18 in png_chunk_error().
+Version 1.0.9beta5 [December 15, 2000]
+  Added support for filter method 64 (for PNG datastreams embedded in MNG).
+Version 1.0.9beta6 [December 18, 2000]
+  Revised png_set_filter() to accept filter method 64 when appropriate.
+  Added new PNG_HAVE_PNG_SIGNATURE bit to png_ptr->mode and use it to
+    help prevent applications from using MNG features in PNG datastreams.
+  Added png_permit_mng_features() function.
+  Revised libpng.3/libpng.txt.  Changed "filter type" to "filter method".
+Version 1.0.9rc1 [December 23, 2000]
+  Revised test for PNG_HAVE_PNG_SIGNATURE in pngrutil.c
+  Fixed error handling of unknown compression type in png_decompress_chunk().
+  In pngconf.h, define __cdecl when _MSC_VER is defined.
+Version 1.0.9beta7 [December 28, 2000]
+  Changed PNG_TEXT_COMPRESSION_zTXt to PNG_COMPRESSION_TYPE_BASE several places.
+  Revised memory management in png_set_hIST and png_handle_hIST in a backward
+    compatible manner.  PLTE and tRNS were revised similarly.
+  Revised the iCCP chunk reader to ignore trailing garbage.
+Version 1.0.9beta8 [January 12, 2001]
+  Moved pngasmrd.h into pngconf.h.
+  Improved handling of out-of-spec garbage iCCP chunks generated by PhotoShop.
+Version 1.0.9beta9 [January 15, 2001]
+  Added png_set_invalid, png_permit_mng_features, and png_mmx_supported to
+    wince and msvc project module definition files.
+  Minor revision of makefile.cygwin.
+  Fixed bug with progressive reading of narrow interlaced images in pngpread.c
+Version 1.0.9beta10 [January 16, 2001]
+  Do not typedef png_FILE_p in pngconf.h when PNG_NO_STDIO is defined.
+  Fixed "png_mmx_supported" typo in project definition files.
+Version 1.0.9beta11 [January 19, 2001]
+  Updated makefile.sgi to make shared library.
+  Removed png_mmx_support() function and disabled PNG_MNG_FEATURES_SUPPORTED
+    by default, for the benefit of DLL forward compatibility.  These will
+    be re-enabled in version 1.2.0.
+Version 1.0.9rc2 [January 22, 2001]
+  Revised cygwin support.
+Version 1.0.9 [January 31, 2001]
+  Added check of cygwin's ALL_STATIC in pngconf.h
+  Added "-nommx" parameter to contrib/gregbook/rpng2-win and rpng2-x demos.
+Version 1.0.10beta1 [March 14, 2001]
+  Revised makefile.dec, makefile.sgi, and makefile.sggcc; added makefile.hpgcc.
+  Reformatted libpng.3 to eliminate bad line breaks.
+  Added checks for _mmx_supported in the read_filter_row function of pnggccrd.c
+  Added prototype for png_mmx_support() near the top of pnggccrd.c
+  Moved some error checking from png_handle_IHDR to png_set_IHDR.
+  Added PNG_NO_READ_SUPPORTED and PNG_NO_WRITE_SUPPORTED macros.
+  Revised png_mmx_support() function in pnggccrd.c
+  Restored version 1.0.8 PNG_WRITE_EMPTY_PLTE_SUPPORTED behavior in pngwutil.c
+  Fixed memory leak in contrib/visupng/PngFile.c
+  Fixed bugs in png_combine_row() in pnggccrd.c and pngvcrd.c (C version)
+  Added warnings when retrieving or setting gamma=0.
+  Increased the first part of msg buffer from 16 to 18 in png_chunk_warning().
+Version 1.0.10rc1 [March 23, 2001]
+  Changed all instances of memcpy, strcpy, and strlen to png_memcpy, png_strcpy,
+    and png_strlen.
+  Revised png_mmx_supported() function in pnggccrd.c to return proper value.
+  Fixed bug in progressive reading (pngpread.c) with small images (height < 8).
+Version 1.0.10 [March 30, 2001]
+  Deleted extraneous space (introduced in 1.0.9) from line 42 of makefile.cygwin
+  Added beos project files (Chris Herborth)
+Version 1.0.11beta1 [April 3, 2001]
+  Added type casts on several png_malloc() calls (Dimitri Papadapoulos).
+  Removed a no-longer needed AIX work-around from pngconf.h
+  Changed several "//" single-line comments to C-style in pnggccrd.c
+Version 1.0.11beta2 [April 11, 2001]
+  Removed PNGAPI from several functions whose prototypes did not have PNGAPI.
+  Updated scripts/pngos2.def
+Version 1.0.11beta3 [April 14, 2001]
+  Added checking the results of many instances of png_malloc() for NULL
+Version 1.0.11beta4 [April 20, 2001]
+  Undid the changes from version 1.0.11beta3.  Added a check for NULL return
+    from user's malloc_fn().
+  Removed some useless type casts of the NULL pointer.
+  Added makefile.netbsd
+Version 1.0.11 [April 27, 2001]
+  Revised makefile.netbsd
+Version 1.0.12beta1 [May 14, 2001]
+  Test for Windows platform in pngconf.h when including malloc.h (Emmanuel Blot)
+  Updated makefile.cygwin and handling of Cygwin's ALL_STATIC in pngconf.h
+  Added some never-to-be-executed code in pnggccrd.c to quiet compiler warnings.
+  Eliminated the png_error about apps using png_read|write_init().  Instead,
+    libpng will reallocate the png_struct and info_struct if they are too small.
+    This retains future binary compatibility for old applications written for
+    libpng-0.88 and earlier.
+Version 1.2.0beta1 [May 6, 2001]
+  Bumped DLLNUM to 2.
+  Re-enabled PNG_MNG_FEATURES_SUPPORTED and enabled PNG_ASSEMBLER_CODE_SUPPORTED
+    by default.
+  Added runtime selection of MMX features.
+  Added png_set_strip_error_numbers function and related macros.
+Version 1.2.0beta2 [May 7, 2001]
+  Finished merging 1.2.0beta1 with version 1.0.11
+  Added a check for attempts to read or write PLTE in grayscale PNG datastreams.
+Version 1.2.0beta3 [May 17, 2001]
+  Enabled user memory function by default.
+  Modified png_create_struct so it passes user mem_ptr to user memory allocator.
+  Increased png_mng_features flag from png_byte to png_uint_32.
+  Bumped shared-library (so-number) and dll-number to 3.
+Version 1.2.0beta4 [June 23, 2001]
+  Check for missing profile length field in iCCP chunk and free chunk_data
+     in case of truncated iCCP chunk.
+  Bumped shared-library number to 3 in makefile.sgi and makefile.sggcc
+  Bumped dll-number from 2 to 3 in makefile.cygwin
+  Revised contrib/gregbook/rpng*-x.c to avoid a memory leak and to exit cleanly
+     if user attempts to run it on an 8-bit display.
+  Updated contrib/gregbook
+  Use png_malloc instead of png_zalloc to allocate palette in pngset.c
+  Updated makefile.ibmc
+  Added some typecasts to eliminate gcc 3.0 warnings.  Changed prototypes
+     of png_write_oFFS width and height from png_uint_32 to png_int_32.
+  Updated example.c
+  Revised prototypes for png_debug_malloc and png_debug_free in pngtest.c
+Version 1.2.0beta5 [August 8, 2001]
+  Revised contrib/gregbook
+  Revised makefile.gcmmx
+  Revised pnggccrd.c to conditionally compile some thread-unsafe code only
+     when PNG_THREAD_UNSAFE_OK is defined.
+  Added tests to prevent pngwutil.c from writing a bKGD or tRNS chunk with
+     value exceeding 2^bit_depth-1
+  Revised makefile.sgi and makefile.sggcc
+  Replaced calls to fprintf(stderr,...) with png_warning() in pnggccrd.c
+  Removed restriction that do_invert_mono only operate on 1-bit opaque files
+Version 1.2.0 [September 1, 2001]
+  Changed a png_warning() to png_debug() in pnggccrd.c
+  Fixed contrib/gregbook/rpng-x.c, rpng2-x.c to avoid crash with XFreeGC().
+Version 1.2.1beta1 [October 19, 2001]
+  Revised makefile.std in contrib/pngminus
+  Include background_1 in png_struct regardless of gamma support.
+  Revised makefile.netbsd and makefile.macosx, added makefile.darwin.
+  Revised example.c to provide more details about using row_callback().
+Version 1.2.1beta2 [October 25, 2001]
+  Added type cast to each NULL appearing in a function call, except for
+    WINCE functions.
+  Added makefile.so9.
+Version 1.2.1beta3 [October 27, 2001]
+  Removed type casts from all NULLs.
+  Simplified png_create_struct_2().
+Version 1.2.1beta4 [November 7, 2001]
+  Revised png_create_info_struct() and png_creat_struct_2().
+  Added error message if png_write_info() was omitted.
+  Type cast NULLs appearing in function calls when _NO_PROTO or
+    PNG_TYPECAST_NULL is defined.
+Version 1.2.1rc1 [November 24, 2001]
+  Type cast NULLs appearing in function calls except when PNG_NO_TYPECAST_NULL
+    is defined.
+  Changed typecast of "size" argument to png_size_t in pngmem.c calls to
+    the user malloc_fn, to agree with the prototype in png.h
+  Added a pop/push operation to pnggccrd.c, to preserve Eflag (Maxim Sobolev)
+  Updated makefile.sgi to recognize LIBPATH and INCPATH.
+  Updated various makefiles so "make clean" does not remove previous major
+    version of the shared library.
+Version 1.2.1rc2 [December 4, 2001]
+  Always allocate 256-entry internal palette, hist, and trans arrays, to
+    avoid out-of-bounds memory reference caused by invalid PNG datastreams.
+  Added a check for prefix_length > data_length in iCCP chunk handler.
+Version 1.2.1 [December 7, 2001]
+  None.
+Version 1.2.2beta1 [February 22, 2002]
+  Fixed a bug with reading the length of iCCP profiles (Larry Reeves).
+  Revised makefile.linux, makefile.gcmmx, and makefile.sgi to generate
+    libpng.a, libpng12.so (not libpng.so.3), and libpng12/png.h
+  Revised makefile.darwin to remove "-undefined suppress" option.
+  Added checks for gamma and chromaticity values over 21474.83, which exceed
+    the limit for PNG unsigned 32-bit integers when encoded.
+  Revised calls to png_create_read_struct() and png_create_write_struct()
+    for simpler debugging.
+  Revised png_zalloc() so zlib handles errors (uses PNG_FLAG_MALLOC_NULL_MEM_OK)
+Version 1.2.2beta2 [February 23, 2002]
+  Check chunk_length and idat_size for invalid (over PNG_MAX_UINT) lengths.
+  Check for invalid image dimensions in png_get_IHDR.
+  Added missing "fi;" in the install target of the SGI makefiles.
+  Added install-static to all makefiles that make shared libraries.
+  Always do gamma compensation when image is partially transparent.
+Version 1.2.2beta3 [March 7, 2002]
+  Compute background.gray and background_1.gray even when color_type is RGB
+    in case image gets reduced to gray later.
+  Modified shared-library makefiles to install pkgconfig/libpngNN.pc.
+  Export (with PNGAPI) png_zalloc, png_zfree, and png_handle_as_unknown
+  Removed unused png_write_destroy_info prototype from png.h
+  Eliminated incorrect use of width_mmx from pnggccrd.c in pixel_bytes == 8 case
+  Added install-shared target to all makefiles that make shared libraries.
+  Stopped a double free of palette, hist, and trans when not using free_me.
+  Added makefile.32sunu for Sun Ultra 32 and makefile.64sunu for Sun Ultra 64.
+Version 1.2.2beta4 [March 8, 2002]
+  Compute background.gray and background_1.gray even when color_type is RGB
+    in case image gets reduced to gray later (Jason Summers).
+  Relocated a misplaced /bin/rm in the "install-shared" makefile targets
+  Added PNG_1_0_X macro which can be used to build a 1.0.x-compatible library.
+Version 1.2.2beta5 [March 26, 2002]
+  Added missing PNGAPI to several function definitions.
+  Check for invalid bit_depth or color_type in png_get_IHDR(), and
+    check for missing PLTE or IHDR in png_push_read_chunk() (Matthias Clasen).
+  Revised iTXt support to accept NULL for lang and lang_key.
+  Compute gamma for color components of background even when color_type is gray.
+  Changed "()" to "{}" in scripts/libpng.pc.in.
+  Revised makefiles to put png.h and pngconf.h only in $prefix/include/libpngNN
+  Revised makefiles to make symlink to libpng.so.NN in addition to libpngNN.so
+Version 1.2.2beta6 [March 31, 2002]
+Version 1.0.13beta1 [March 31, 2002]
+  Prevent png_zalloc() from trying to memset memory that it failed to acquire.
+  Add typecasts of PNG_MAX_UINT in pngset_cHRM_fixed() (Matt Holgate).
+  Ensure that the right function (user or default) is used to free the
+    png_struct after an error in png_create_read_struct_2().
+Version 1.2.2rc1 [April 7, 2002]
+Version 1.0.13rc1 [April 7, 2002]
+  Save the ebx register in pnggccrd.c (Sami Farin)
+  Add "mem_ptr = png_ptr->mem_ptr" in png_destroy_write_struct() (Paul Gardner).
+  Updated makefiles to put headers in include/libpng and remove old include/*.h.
+Version 1.2.2 [April 15, 2002]
+Version 1.0.13 [April 15, 2002]
+  Revised description of png_set_filter() in libpng.3/libpng.txt.
+  Revised makefile.netbsd and added makefile.neNNbsd and makefile.freebsd
+Version 1.0.13patch01 [April 17, 2002]
+Version 1.2.2patch01 [April 17, 2002]
+  Changed ${PNGMAJ}.${PNGVER} bug to ${PNGVER} in makefile.sgi and
+    makefile.sggcc
+  Fixed VER -> PNGVER typo in makefile.macosx and added install-static to
+    install
+  Added install: target to makefile.32sunu and makefile.64sunu
+Version 1.0.13patch03 [April 18, 2002]
+Version 1.2.2patch03 [April 18, 2002]
+  Revised 15 makefiles to link libpng.a to libpngNN.a and the include libpng
+  subdirectory to libpngNN subdirectory without the full pathname.
+  Moved generation of libpng.pc from "install" to "all" in 15 makefiles.
+Version 1.2.3rc1 [April 28, 2002]
+  Added install-man target to 15 makefiles (Dimitri Papadopolous-Orfanos).
+  Added $(DESTDIR) feature to 24 makefiles (Tim Mooney)
+  Fixed bug with $prefix, should be $(prefix) in makefile.hpux.
+  Updated cygwin-specific portion of pngconf.h and revised makefile.cygwin
+  Added a link from libpngNN.pc to libpng.pc in 15 makefiles.
+  Added links from include/libpngNN/*.h to include/*.h in 24 makefiles.
+  Revised makefile.darwin to make relative links without full pathname.
+  Added setjmp() at the end of png_create_*_struct_2() in case user forgets
+    to put one in their application.
+  Restored png_zalloc() and png_zfree() prototypes to version 1.2.1 and
+    removed them from module definition files.
+Version 1.2.3rc2 [May 1, 2002]
+  Fixed bug in reporting number of channels in pngget.c and pngset.c,
+    that was introduced in version 1.2.2beta5.
+  Exported png_zalloc(), png_zfree(), png_default_read(), png_default_write(),
+    png_default_flush(), and png_push_fill_buffer() and included them in
+    module definition files.
+  Added "libpng.pc" dependency to the "install-shared" target in 15 makefiles.
+Version 1.2.3rc3 [May 1, 2002]
+  Revised prototype for png_default_flush()
+  Remove old libpng.pc and libpngNN.pc before installing new ones.
+Version 1.2.3rc4 [May 2, 2002]
+  Typos in *.def files (png_default_read|write -> png_default_read|write_data)
+  In makefiles, changed rm libpng.NN.pc to rm libpngNN.pc
+  Added libpng-config and libpngNN-config and modified makefiles to install
+    them.
+  Changed $(MANPATH) to $(DESTDIR)$(MANPATH) in makefiles
+  Added "Win32 DLL VB" configuration to projects/msvc/libpng.dsp
+Version 1.2.3rc5 [May 11, 2002]
+  Changed "error" and "message" in prototypes to "error_message" and
+    "warning_message" to avoid namespace conflict.
+  Revised 15 makefiles to build libpng-config from libpng-config-*.in
+  Once more restored png_zalloc and png_zfree to regular nonexported form.
+  Restored png_default_read|write_data, png_default_flush, png_read_fill_buffer
+    to nonexported form, but with PNGAPI, and removed them from module def
+    files.
+Version 1.2.3rc6 [May 14, 2002]
+  Removed "PNGAPI" from png_zalloc() and png_zfree() in png.c
+  Changed "Gz" to "Gd" in projects/msvc/libpng.dsp and zlib.dsp.
+  Removed leftover libpng-config "sed" script from four makefiles.
+  Revised libpng-config creating script in 16 makefiles.
+Version 1.2.3 [May 22, 2002]
+  Revised libpng-config target in makefile.cygwin.
+  Removed description of png_set_mem_fn() from documentation.
+  Revised makefile.freebsd.
+  Minor cosmetic changes to 15 makefiles, e.g., $(DI) = $(DESTDIR)/$(INCDIR).
+  Revised projects/msvc/README.txt
+  Changed -lpng to -lpngNN in LDFLAGS in several makefiles.
+Version 1.2.4beta1 [May 24, 2002]
+  Added libpng.pc and libpng-config to "all:" target in 16 makefiles.
+  Fixed bug in 16 makefiles: $(DESTDIR)/$(LIBPATH) to $(DESTDIR)$(LIBPATH)
+  Added missing "\" before closing double quote in makefile.gcmmx.
+  Plugged various memory leaks; added png_malloc_warn() and png_set_text_2()
+    functions.
+Version 1.2.4beta2 [June 25, 2002]
+  Plugged memory leak of png_ptr->current_text (Matt Holgate).
+  Check for buffer overflow before reading CRC in pngpread.c (Warwick Allison)
+  Added -soname to the loader flags in makefile.dec, makefile.sgi, and
+    makefile.sggcc.
+  Added "test-installed" target to makefile.linux, makefile.gcmmx,
+    makefile.sgi, and makefile.sggcc.
+Version 1.2.4beta3 [June 28, 2002]
+  Plugged memory leak of row_buf in pngtest.c when there is a png_error().
+  Detect buffer overflow in pngpread.c when IDAT is corrupted with extra data.
+  Added "test-installed" target to makefile.32sunu, makefile.64sunu,
+    makefile.beos, makefile.darwin, makefile.dec, makefile.macosx,
+    makefile.solaris, makefile.hpux, makefile.hpgcc, and makefile.so9.
+Version 1.2.4rc1 and 1.0.14rc1 [July 2, 2002]
+  Added "test-installed" target to makefile.cygwin and makefile.sco.
+  Revised pnggccrd.c to be able to back out version 1.0.x via PNG_1_0_X macro.
+Version 1.2.4 and 1.0.14 [July 8, 2002]
+  Changed png_warning() to png_error() when width is too large to process.
+Version 1.2.4patch01 [July 20, 2002]
+  Revised makefile.cygwin to use DLL number 12 instead of 13.
+Version 1.2.5beta1 [August 6, 2002]
+  Added code to contrib/gregbook/readpng2.c to ignore unused chunks.
+  Replaced toucan.png in contrib/gregbook (it has been corrupt since 1.0.11)
+  Removed some stray *.o files from contrib/gregbook.
+  Changed png_error() to png_warning() about "Too much data" in pngpread.c
+    and about "Extra compressed data" in pngrutil.c.
+  Prevent png_ptr->pass from exceeding 7 in png_push_finish_row().
+  Updated makefile.hpgcc
+  Updated png.c and pnggccrd.c handling of return from png_mmx_support()
+Version 1.2.5beta2 [August 15, 2002]
+  Only issue png_warning() about "Too much data" in pngpread.c when avail_in
+    is nonzero.
+  Updated makefiles to install a separate libpng.so.3 with its own rpath.
+Version 1.2.5rc1 and 1.0.15rc1 [August 24, 2002]
+  Revised makefiles to not remove previous minor versions of shared libraries.
+Version 1.2.5rc2 and 1.0.15rc2 [September 16, 2002]
+  Revised 13 makefiles to remove "-lz" and "-L$(ZLIBLIB)", etc., from shared
+    library loader directive.
+  Added missing "$OBJSDLL" line to makefile.gcmmx.
+  Added missing "; fi" to makefile.32sunu.
+Version 1.2.5rc3 and 1.0.15rc3 [September 18, 2002]
+  Revised libpng-config script.
+Version 1.2.5 and 1.0.15 [October 3, 2002]
+  Revised makefile.macosx, makefile.darwin, makefile.hpgcc, and makefile.hpux,
+    and makefile.aix.
+  Relocated two misplaced PNGAPI lines in pngtest.c
+Version 1.2.6beta1 [October 22, 2002]
+  Commented out warning about uninitialized mmx_support in pnggccrd.c.
+  Changed "IBMCPP__" flag to "__IBMCPP__" in pngconf.h.
+  Relocated two more misplaced PNGAPI lines in pngtest.c
+  Fixed memory overrun bug in png_do_read_filler() with 16-bit datastreams,
+    introduced in version 1.0.2.
+  Revised makefile.macosx, makefile.dec, makefile.aix, and makefile.32sunu.
+Version 1.2.6beta2 [November 1, 2002]
+  Added libpng-config "--ldopts" output.
+  Added "AR=ar" and "ARFLAGS=rc" and changed "ar rc" to "$(AR) $(ARFLAGS)"
+    in makefiles.
+Version 1.2.6beta3 [July 18, 2004]
+  Reverted makefile changes from version 1.2.6beta2 and some of the changes
+    from version 1.2.6beta1; these will be postponed until version 1.2.7.
+    Version 1.2.6 is going to be a simple bugfix release.
+  Changed the one instance of "ln -sf" to "ln -f -s" in each Sun makefile.
+  Fixed potential overrun in pngerror.c by using strncpy instead of memcpy.
+  Added "#!/bin/sh" at the top of configure, for recognition of the
+    'x' flag under Cygwin (Cosmin).
+  Optimized vacuous tests that silence compiler warnings, in png.c (Cosmin).
+  Added support for PNG_USER_CONFIG, in pngconf.h (Cosmin).
+  Fixed the special memory handler for Borland C under DOS, in pngmem.c
+    (Cosmin).
+  Removed some spurious assignments in pngrutil.c (Cosmin).
+  Replaced 65536 with 65536L, and 0xffff with 0xffffL, to silence warnings
+    on 16-bit platforms (Cosmin).
+  Enclosed shift op expressions in parentheses, to silence warnings (Cosmin).
+  Used proper type png_fixed_point, to avoid problems on 16-bit platforms,
+    in png_handle_sRGB() (Cosmin).
+  Added compression_type to png_struct, and optimized the window size
+    inside the deflate stream (Cosmin).
+  Fixed definition of isnonalpha(), in pngerror.c and pngrutil.c (Cosmin).
+  Fixed handling of unknown chunks that come after IDAT (Cosmin).
+  Allowed png_error() and png_warning() to work even if png_ptr == NULL
+    (Cosmin).
+  Replaced row_info->rowbytes with row_bytes in png_write_find_filter()
+    (Cosmin).
+  Fixed definition of PNG_LIBPNG_VER_DLLNUM (Simon-Pierre).
+  Used PNG_LIBPNG_VER and PNG_LIBPNG_VER_STRING instead of the hardcoded
+    values in png.c (Simon-Pierre, Cosmin).
+  Initialized png_libpng_ver[] with PNG_LIBPNG_VER_STRING (Simon-Pierre).
+  Replaced PNG_LIBPNG_VER_MAJOR with PNG_LIBPNG_VER_DLLNUM in png.rc
+    (Simon-Pierre).
+  Moved the definition of PNG_HEADER_VERSION_STRING near the definitions
+    of the other PNG_LIBPNG_VER_... symbols in png.h (Cosmin).
+  Relocated #ifndef PNGAPI guards in pngconf.h (Simon-Pierre, Cosmin).
+  Updated scripts/makefile.vc(a)win32 (Cosmin).
+  Updated the MSVC project (Simon-Pierre, Cosmin).
+  Updated the Borland C++ Builder project (Cosmin).
+  Avoided access to asm_flags in pngvcrd.c, if PNG_1_0_X is defined (Cosmin).
+  Commented out warning about uninitialized mmx_support in pngvcrd.c (Cosmin).
+  Removed scripts/makefile.bd32 and scripts/pngdef.pas (Cosmin).
+  Added extra guard around inclusion of Turbo C memory headers, in pngconf.h
+    (Cosmin).
+  Renamed projects/msvc/ to projects/visualc6/, and projects/borland/ to
+    projects/cbuilder5/ (Cosmin).
+  Moved projects/visualc6/png32ms.def to scripts/pngw32.def,
+    and projects/visualc6/png.rc to scripts/pngw32.rc (Cosmin).
+  Added projects/visualc6/pngtest.dsp; removed contrib/msvctest/ (Cosmin).
+  Changed line endings to DOS style in cbuilder5 and visualc6 files, even
+    in the tar.* distributions (Cosmin).
+  Updated contrib/visupng/VisualPng.dsp (Cosmin).
+  Updated contrib/visupng/cexcept.h to version 2.0.0 (Cosmin).
+  Added a separate distribution with "configure" and supporting files (Junichi).
+Version 1.2.6beta4 [July 28, 2004]
+  Added user ability to change png_size_t via a PNG_SIZE_T macro.
+  Added png_sizeof() and png_convert_size() functions.
+  Added PNG_SIZE_MAX (maximum value of a png_size_t variable.
+  Added check in png_malloc_default() for (size_t)size != (png_uint_32)size
+    which would indicate an overflow.
+  Changed sPLT failure action from png_error to png_warning and abandon chunk.
+  Changed sCAL and iCCP failures from png_error to png_warning and abandon.
+  Added png_get_uint_31(png_ptr, buf) function.
+  Added PNG_UINT_32_MAX macro.
+  Renamed PNG_MAX_UINT to PNG_UINT_31_MAX.
+  Made png_zalloc() issue a png_warning and return NULL on potential
+    overflow.
+  Turn on PNG_NO_ZALLOC_ZERO by default in version 1.2.x
+  Revised "clobber list" in pnggccrd.c so it will compile under gcc-3.4.
+  Revised Borland portion of png_malloc() to return NULL or issue
+    png_error() according to setting of PNG_FLAG_MALLOC_NULL_MEM_OK.
+  Added PNG_NO_SEQUENTIAL_READ_SUPPORTED macro to conditionally remove
+    sequential read support.
+  Added some "#if PNG_WRITE_SUPPORTED" blocks.
+  Added #ifdef to remove some redundancy in png_malloc_default().
+  Use png_malloc instead of png_zalloc to allocate the pallete.
+Version 1.0.16rc1 and 1.2.6rc1 [August 4, 2004]
+  Fixed buffer overflow vulnerability in png_handle_tRNS()
+  Fixed integer arithmetic overflow vulnerability in png_read_png().
+  Fixed some harmless bugs in png_handle_sBIT, etc, that would cause
+    duplicate chunk types to go undetected.
+  Fixed some timestamps in the -config version
+  Rearranged order of processing of color types in png_handle_tRNS().
+  Added ROWBYTES macro to calculate rowbytes without integer overflow.
+  Updated makefile.darwin and removed makefile.macosx from scripts directory.
+  Imposed default one million column, one-million row limits on the image
+    dimensions, and added png_set_user_limits() function to override them.
+  Revised use of PNG_SET_USER_LIMITS_SUPPORTED macro.
+  Fixed wrong cast of returns from png_get_user_width|height_max().
+  Changed some "keep the compiler happy" from empty statements to returns,
+  Revised libpng.txt to remove 1.2.x stuff from the 1.0.x distribution
+Version 1.0.16rc2 and 1.2.6rc2 [August 7, 2004]
+  Revised makefile.darwin and makefile.solaris.  Removed makefile.macosx.
+  Revised pngtest's png_debug_malloc() to use png_malloc() instead of
+    png_malloc_default() which is not supposed to be exported.
+  Fixed off-by-one error in one of the conversions to PNG_ROWBYTES() in
+    pngpread.c.  Bug was introduced in 1.2.6rc1.
+  Fixed bug in RGB to RGBX transformation introduced in 1.2.6rc1.
+  Fixed old bug in RGB to Gray transformation.
+  Fixed problem with 64-bit compilers by casting arguments to abs()
+    to png_int_32.
+  Changed "ln -sf" to "ln -f -s" in three makefiles (solaris, sco, so9).
+  Changed "HANDLE_CHUNK_*" to "PNG_HANDLE_CHUNK_*" (Cosmin)
+  Added "-@/bin/rm -f $(DL)/$(LIBNAME).so.$(PNGMAJ)" to 15 *NIX makefiles.
+  Added code to update the row_info->colortype in png_do_read_filler() (MSB).
+Version 1.0.16rc3 and 1.2.6rc3 [August 9, 2004]
+  Eliminated use of "abs()" in testing cHRM and gAMA values, to avoid
+    trouble with some 64-bit compilers.  Created PNG_OUT_OF_RANGE() macro.
+  Revised documentation of png_set_keep_unknown_chunks().
+  Check handle_as_unknown status in pngpread.c, as in pngread.c previously.
+  Moved  "PNG_HANDLE_CHUNK_*" macros out of PNG_INTERNAL section of png.h
+  Added "rim" definitions for CONST4 and CONST6 in pnggccrd.c
+Version 1.0.16rc4 and 1.2.6rc4 [August 10, 2004]
+  Fixed mistake in pngtest.c introduced in 1.2.6rc2 (declaration of
+    "pinfo" was out of place).
+Version 1.0.16rc5 and 1.2.6rc5 [August 10, 2004]
+  Moved  "PNG_HANDLE_CHUNK_*" macros out of PNG_ASSEMBLER_CODE_SUPPORTED
+     section of png.h where they were inadvertently placed in version rc3.
+Version 1.2.6 and 1.0.16 [August 15, 2004]
+  Revised pngtest so memory allocation testing is only done when PNG_DEBUG==1.
+Version 1.2.7beta1 [August 26, 2004]
+  Removed unused pngasmrd.h file.
+  Removed references to uu.net for archived files.  Added references to
+    PNG Spec (second edition) and the PNG ISO/IEC Standard.
+  Added "test-dd" target in 15 makefiles, to run pngtest in DESTDIR.
+  Fixed bug with "optimized window size" in the IDAT datastream, that
+    causes libpng to write PNG files with incorrect zlib header bytes.
+Version 1.2.7beta2 [August 28, 2004]
+  Fixed bug with sCAL chunk and big-endian machines (David Munro).
+  Undid new code added in 1.2.6rc2 to update the color_type in
+    png_set_filler().
+  Added png_set_add_alpha() that updates color type.
+Version 1.0.17rc1 and 1.2.7rc1 [September 4, 2004]
+  Revised png_set_strip_filler() to not remove alpha if color_type has alpha.
+Version 1.2.7 and 1.0.17 [September 12, 2004]
+  Added makefile.hp64
+  Changed projects/msvc/png32ms.def to scripts/png32ms.def in makefile.cygwin
+Version 1.2.8beta1 [November 1, 2004]
+  Fixed bug in png_text_compress() that would fail to complete a large block.
+  Fixed bug, introduced in libpng-1.2.7, that overruns a buffer during
+    strip alpha operation in png_do_strip_filler().
+  Added PNG_1_2_X definition in pngconf.h
+  Use #ifdef to comment out png_info_init in png.c and png_read_init in
+    pngread.c (as of 1.3.0)
+Version 1.2.8beta2 [November 2, 2004]
+  Reduce color_type to a nonalpha type after strip alpha operation in
+    png_do_strip_filler().
+Version 1.2.8beta3 [November 3, 2004]
+  Revised definitions of PNG_MAX_UINT_32, PNG_MAX_SIZE, and PNG_MAXSUM
+Version 1.2.8beta4 [November 12, 2004]
+  Fixed (again) definition of PNG_LIBPNG_VER_DLLNUM in png.h (Cosmin).
+  Added PNG_LIBPNG_BUILD_PRIVATE in png.h (Cosmin).
+  Set png_ptr->zstream.data_type to Z_BINARY, to avoid unnecessary detection
+    of data type in deflate (Cosmin).
+  Deprecated but continue to support SPECIALBUILD and PRIVATEBUILD in favor of
+    PNG_LIBPNG_BUILD_SPECIAL_STRING and PNG_LIBPNG_BUILD_PRIVATE_STRING.
+Version 1.2.8beta5 [November 20, 2004]
+  Use png_ptr->flags instead of png_ptr->transformations to pass
+    PNG_STRIP_ALPHA info to png_do_strip_filler(), to preserve ABI
+    compatibility.
+  Revised handling of SPECIALBUILD, PRIVATEBUILD,
+    PNG_LIBPNG_BUILD_SPECIAL_STRING and PNG_LIBPNG_BUILD_PRIVATE_STRING.
+Version 1.2.8rc1 [November 24, 2004]
+  Moved handling of BUILD macros from pngconf.h to png.h
+  Added definition of PNG_LIBPNG_BASE_TYPE in png.h, inadvertently
+    omitted from beta5.
+  Revised scripts/pngw32.rc
+  Despammed mailing addresses by masking "@" with "at".
+  Inadvertently installed a supposedly faster test version of pngrutil.c
+Version 1.2.8rc2 [November 26, 2004]
+  Added two missing "\" in png.h
+  Change tests in pngread.c and pngpread.c to
+    if (png_ptr->transformations || (png_ptr->flags&PNG_FLAG_STRIP_ALPHA))
+       png_do_read_transformations(png_ptr);
+Version 1.2.8rc3 [November 28, 2004]
+  Reverted pngrutil.c to version libpng-1.2.8beta5.
+  Added scripts/makefile.elf with supporting code in pngconf.h for symbol
+    versioning (John Bowler).
+Version 1.2.8rc4 [November 29, 2004]
+  Added projects/visualc7 (Simon-pierre).
+Version 1.2.8rc5 [November 29, 2004]
+  Fixed new typo in scripts/pngw32.rc
+Version 1.2.8 [December 3, 2004]
+  Removed projects/visualc7, added projects/visualc71.
+Version 1.2.9beta1 [February 21, 2006]
+  Initialized some structure members in pngwutil.c to avoid gcc-4.0.0 complaints
+  Revised man page and libpng.txt to make it clear that one should not call
+    png_read_end or png_write_end after png_read_png or png_write_png.
+  Updated references to png-mng-implement mailing list.
+  Fixed an incorrect typecast in pngrutil.c
+  Added PNG_NO_READ_SUPPORTED conditional for making a write-only library.
+  Added PNG_NO_WRITE_INTERLACING_SUPPORTED conditional.
+  Optimized alpha-inversion loops in pngwtran.c
+  Moved test for nonzero gamma outside of png_build_gamma_table() in pngrtran.c
+  Make sure num_trans is <= 256 before copying data in png_set_tRNS().
+  Make sure num_palette is <= 256 before copying data in png_set_PLTE().
+  Interchanged order of write_swap_alpha and write_invert_alpha transforms.
+  Added parentheses in the definition of PNG_LIBPNG_BUILD_TYPE (Cosmin).
+  Optimized zlib window flag (CINFO) in contrib/pngsuite/*.png (Cosmin).
+  Updated scripts/makefile.bc32 for Borland C++ 5.6 (Cosmin).
+  Exported png_get_uint_32, png_save_uint_32, png_get_uint_16, png_save_uint_16,
+    png_get_int_32, png_save_int_32, png_get_uint_31 (Cosmin).
+  Added type cast (png_byte) in png_write_sCAL() (Cosmin).
+  Fixed scripts/makefile.cygwin (Christian Biesinger, Cosmin).
+  Default iTXt support was inadvertently enabled.
+Version 1.2.9beta2 [February 21, 2006]
+  Check for png_rgb_to_gray and png_gray_to_rgb read transformations before
+    checking for png_read_dither in pngrtran.c
+  Revised checking of chromaticity limits to accommodate extended RGB
+    colorspace (John Denker).
+  Changed line endings in some of the project files to CRLF, even in the
+    "Unix" tar distributions (Cosmin).
+  Made png_get_int_32 and png_save_int_32 always available (Cosmin).
+  Updated scripts/pngos2.def, scripts/pngw32.def and projects/wince/png32ce.def
+    with the newly exported functions.
+  Eliminated distributions without the "configure" script.
+  Updated INSTALL instructions.
+Version 1.2.9beta3 [February 24, 2006]
+  Fixed CRCRLF line endings in contrib/visupng/VisualPng.dsp
+  Made libpng.pc respect EXEC_PREFIX (D. P. Kreil, J. Bowler)
+  Removed reference to pngasmrd.h from Makefile.am
+  Renamed CHANGES to ChangeLog.
+  Renamed LICENSE to COPYING.
+  Renamed ANNOUNCE to NEWS.
+  Created AUTHORS file.
+Version 1.2.9beta4 [March 3, 2006]
+  Changed definition of PKGCONFIG from $prefix/lib to $libdir in configure.ac
+  Reverted to filenames LICENSE and ANNOUNCE; removed AUTHORS and COPYING.
+  Removed newline from the end of some error and warning messages.
+  Removed test for sqrt() from configure.ac and configure.
+  Made swap tables in pngtrans.c PNG_CONST (Carlo Bramix).
+  Disabled default iTXt support that was inadvertently enabled in
+    libpng-1.2.9beta1.
+  Added "OS2" to list of systems that don't need underscores, in pnggccrd.c
+  Removed libpng version and date from *.c files.
+Version 1.2.9beta5 [March 4, 2006]
+  Removed trailing blanks from source files.
+  Put version and date of latest change in each source file, and changed
+    copyright year accordingly.
+  More cleanup of configure.ac, Makefile.am, and associated scripts.
+  Restored scripts/makefile.elf which was inadvertently deleted.
+Version 1.2.9beta6 [March 6, 2006]
+  Fixed typo (RELEASE) in configuration files.
+Version 1.2.9beta7 [March 7, 2006]
+  Removed libpng.vers and libpng.sym from libpng12_la_SOURCES in Makefile.am
+  Fixed inconsistent #ifdef's around png_sig_bytes() and png_set_sCAL_s()
+    in png.h.
+  Updated makefile.elf as suggested by debian.
+  Made cosmetic changes to some makefiles, adding LN_SF and other macros.
+  Made some makefiles accept "exec_prefix".
+Version 1.2.9beta8 [March 9, 2006]
+  Fixed some "#if defined (..." which should be "#if defined(..."
+    Bug introduced in libpng-1.2.8.
+  Fixed inconsistency in definition of png_default_read_data()
+  Restored blank that was lost from makefile.sggcc "clean" target in beta7.
+  Revised calculation of "current" and "major" for irix in ltmain.sh
+  Changed "mkdir" to "MKDIR_P" in some makefiles.
+  Separated PNG_EXPAND and PNG_EXPAND_tRNS.
+  Added png_set_expand_gray_1_2_4_to_8() and deprecated
+    png_set_gray_1_2_4_to_8() which also expands tRNS to alpha.
+Version 1.2.9beta9 [March 10, 2006]
+  Include "config.h" in pngconf.h when available.
+  Added some checks for NULL png_ptr or NULL info_ptr (timeless)
+Version 1.2.9beta10 [March 20, 2006]
+  Removed extra CR from contrib/visualpng/VisualPng.dsw (Cosmin)
+  Made pnggccrd.c PIC-compliant (Christian Aichinger).
+  Added makefile.mingw (Wolfgang Glas).
+  Revised pngconf.h MMX checking.
+Version 1.2.9beta11 [March 22, 2006]
+  Fixed out-of-order declaration in pngwrite.c that was introduced in beta9
+  Simplified some makefiles by using LIBSO, LIBSOMAJ, and LIBSOVER macros.
+Version 1.2.9rc1 [March 31, 2006]
+  Defined PNG_USER_PRIVATEBUILD when including "pngusr.h" (Cosmin).
+  Removed nonsensical assertion check from pngtest.c (Cosmin).
+Version 1.2.9 [April 14, 2006]
+  Revised makefile.beos and added "none" selector in ltmain.sh
+Version 1.2.10beta1 [April 15, 2006]
+  Renamed "config.h" to "png_conf.h" and revised Makefile.am to add
+    -DPNG_BUILDING_LIBPNG to compile directive, and modified pngconf.h
+    to include png_conf.h only when PNG_BUILDING_LIBPNG is defined.
+Version 1.2.10beta2 [April 15, 2006]
+  Manually updated Makefile.in and configure.  Changed png_conf.h.in
+    back to config.h.
+Version 1.2.10beta3 [April 15, 2006]
+  Change png_conf.h back to config.h in pngconf.h.
+Version 1.2.10beta4 [April 16, 2006]
+  Change PNG_BUILDING_LIBPNG to PNG_CONFIGURE_LIBPNG in config/Makefile*.
+Version 1.2.10beta5 [April 16, 2006]
+  Added a configure check for compiling assembler code in pnggccrd.c
+Version 1.2.10beta6 [April 17, 2006]
+  Revised the configure check for pnggccrd.c
+  Moved -DPNG_CONFIGURE_LIBPNG into @LIBPNG_DEFINES@
+  Added @LIBPNG_DEFINES@ to arguments when building libpng.sym
+Version 1.2.10beta7 [April 18, 2006]
+  Change "exec_prefix=$prefix" to "exec_prefix=$(prefix)" in makefiles.
+Version 1.2.10rc1 [April 19, 2006]
+  Ensure pngconf.h doesn't define both PNG_USE_PNGGCCRD and PNG_USE_PNGVCRD
+  Fixed "LN_FS" typo in makefile.sco and makefile.solaris.
+Version 1.2.10rc2 [April 20, 2006]
+  Added a backslash between -DPNG_CONFIGURE_LIBPNG and -DPNG_NO_ASSEMBLER_CODE
+   in configure.ac and configure
+  Made the configure warning about versioned symbols less arrogant.
+Version 1.2.10rc3 [April 21, 2006]
+  Added a note in libpng.txt that png_set_sig_bytes(8) can be used when
+    writing an embedded PNG without the 8-byte signature.
+  Revised makefiles and configure to avoid making links to libpng.so.*
+Version 1.2.10 [April 23, 2006]
+  Reverted configure to "rc2" state.
+Version 1.2.11beta1 [May 31, 2006]
+  scripts/libpng.pc.in contained "configure" style version info and would
+    not work with makefiles.
+  The shared-library makefiles were linking to libpng.so.0 instead of
+    libpng.so.3 compatibility as the library.
+Version 1.2.11beta2 [June 2, 2006]
+  Increased sprintf buffer from 50 to 52 chars in pngrutil.c to avoid
+    buffer overflow.
+  Fixed bug in example.c (png_set_palette_rgb -> png_set_palette_to_rgb)
+Version 1.2.11beta3 [June 5, 2006]
+  Prepended "#! /bin/sh" to ltmail.sh and contrib/pngminus/*.sh (Cosmin).
+  Removed the accidental leftover Makefile.in~ (Cosmin).
+  Avoided potential buffer overflow and optimized buffer in
+    png_write_sCAL(), png_write_sCAL_s() (Cosmin).
+  Removed the include directories and libraries from CFLAGS and LDFLAGS
+    in scripts/makefile.gcc (Nelson A. de Oliveira, Cosmin).
+Version 1.2.11beta4 [June 6, 2006]
+  Allow zero-length IDAT chunks after the entire zlib datastream, but not
+    after another intervening chunk type.
+Version 1.0.19rc1, 1.2.11rc1 [June 13, 2006]
+  Deleted extraneous square brackets from [config.h] in configure.ac
+Version 1.0.19rc2, 1.2.11rc2 [June 14, 2006]
+  Added prototypes for PNG_INCH_CONVERSIONS functions to png.h
+  Revised INSTALL and autogen.sh
+  Fixed typo in several makefiles (-W1 should be -Wl)
+  Added typedef for png_int_32 and png_uint_32 on 64-bit systems.
+Version 1.0.19rc3, 1.2.11rc3 [June 15, 2006]
+  Removed the new typedefs for 64-bit systems (delay until version 1.4.0)
+  Added one zero element to png_gamma_shift[] array in pngrtran.c to avoid
+    reading out of bounds.
+Version 1.0.19rc4, 1.2.11rc4 [June 15, 2006]
+  Really removed the new typedefs for 64-bit systems.
+Version 1.0.19rc5, 1.2.11rc5 [June 22, 2006]
+  Removed png_sig_bytes entry from scripts/pngw32.def
+Version 1.0.19, 1.2.11 [June 26, 2006]
+  None.
+Version 1.0.20, 1.2.12 [June 27, 2006]
+  Really increased sprintf buffer from 50 to 52 chars in pngrutil.c to avoid
+    buffer overflow.
+Version 1.2.13beta1 [October 2, 2006]
+  Removed AC_FUNC_MALLOC from configure.ac
+  Work around Intel-Mac compiler bug by setting PNG_NO_MMX_CODE in pngconf.h
+  Change "logical" to "bitwise" throughout documentation.
+  Detect and fix attempt to write wrong iCCP profile length (CVE-2006-7244)
+Version 1.0.21, 1.2.13 [November 14, 2006]
+  Fix potential buffer overflow in sPLT chunk handler.
+  Fix Makefile.am to not try to link to noexistent files.
+  Check all exported functions for NULL png_ptr.
+Version 1.2.14beta1 [November 17, 2006]
+  Relocated three misplaced tests for NULL png_ptr.
+  Built Makefile.in with automake-1.9.6 instead of 1.9.2.
+  Build configure with autoconf-2.60 instead of 2.59
+Version 1.2.14beta2 [November 17, 2006]
+  Added some typecasts in png_zalloc().
+Version 1.2.14rc1 [November 20, 2006]
+  Changed "strtod" to "png_strtod" in pngrutil.c
+Version 1.0.22, 1.2.14    [November 27, 2006]
+  Added missing "$(srcdir)" in Makefile.am and Makefile.in
+Version 1.2.15beta1 [December 3, 2006]
+  Generated configure with autoconf-2.61 instead of 2.60
+  Revised configure.ac to update libpng.pc and libpng-config.
+Version 1.2.15beta2 [December 3, 2006]
+  Always export MMX asm functions, just stubs if not building pnggccrd.c
+Version 1.2.15beta3 [December 4, 2006]
+  Add "png_bytep" typecast to profile while calculating length in pngwutil.c
+Version 1.2.15beta4 [December 7, 2006]
+  Added scripts/CMakeLists.txt
+  Changed PNG_NO_ASSEMBLER_CODE to PNG_NO_MMX_CODE in scripts, like 1.4.0beta
+Version 1.2.15beta5 [December 7, 2006]
+  Changed some instances of PNG_ASSEMBLER_* to PNG_MMX_* in pnggccrd.c
+  Revised scripts/CMakeLists.txt
+Version 1.2.15beta6 [December 13, 2006]
+  Revised scripts/CMakeLists.txt and configure.ac
+Version 1.2.15rc1 [December 18, 2006]
+  Revised scripts/CMakeLists.txt
+Version 1.2.15rc2 [December 21, 2006]
+  Added conditional #undef jmpbuf in pngtest.c to undo #define in AIX headers.
+  Added scripts/makefile.nommx
+Version 1.2.15rc3 [December 25, 2006]
+  Fixed shared library numbering error that was introduced in 1.2.15beta6.
+Version 1.2.15rc4 [December 27, 2006]
+  Fixed handling of rgb_to_gray when png_ptr->color.gray isn't set.
+Version 1.2.15rc5 [December 31, 2006]
+  Revised handling of rgb_to_gray.
+Version 1.2.15 [January 5, 2007]
+  Added some (unsigned long) typecasts in pngtest.c to avoid printing errors.
+Version 1.2.16beta1 [January 6, 2007]
+  Fix bugs in makefile.nommx
+Version 1.2.16beta2 [January 16, 2007]
+  Revised scripts/CMakeLists.txt
+Version 1.2.16 [January 31, 2007]
+  No changes.
+Version 1.2.17beta1 [March 6, 2007]
+  Revised scripts/CMakeLists.txt to install both shared and static libraries.
+  Deleted a redundant line from pngset.c.
+Version 1.2.17beta2 [April 26, 2007]
+  Relocated misplaced test for png_ptr == NULL in pngpread.c
+  Change "==" to "&" for testing PNG_RGB_TO_GRAY_ERR & PNG_RGB_TO_GRAY_WARN
+    flags.
+  Changed remaining instances of PNG_ASSEMBLER_* to PNG_MMX_*
+  Added pngerror() when write_IHDR fails in deflateInit2().
+  Added "const" to some array declarations.
+  Mention examples of libpng usage in the libpng*.txt and libpng.3 documents.
+Version 1.2.17rc1 [May 4, 2007]
+  No changes.
+Version 1.2.17rc2 [May 8, 2007]
+  Moved several PNG_HAVE_* macros out of PNG_INTERNAL because applications
+    calling set_unknown_chunk_location() need them.
+  Changed transformation flag from PNG_EXPAND_tRNS to PNG_EXPAND in
+    png_set_expand_gray_1_2_4_to_8().
+  Added png_ptr->unknown_chunk to hold working unknown chunk data, so it
+    can be free'ed in case of error.  Revised unknown chunk handling in
+    pngrutil.c and pngpread.c to use this structure.
+Version 1.2.17rc3 [May 8, 2007]
+  Revised symbol-handling in configure script.
+Version 1.2.17rc4 [May 10, 2007]
+  Revised unknown chunk handling to avoid storing unknown critical chunks.
+Version 1.0.25 [May 15, 2007]
+Version 1.2.17 [May 15, 2007]
+  Added "png_ptr->num_trans=0" before error return in png_handle_tRNS,
+    to eliminate a vulnerability (CVE-2007-2445, CERT VU#684664)
+Version 1.0.26 [May 15, 2007]
+Version 1.2.18 [May 15, 2007]
+  Reverted the libpng-1.2.17rc3 change to symbol-handling in configure script
+Version 1.2.19beta1 [May 18, 2007]
+  Changed "const static" to "static PNG_CONST" everywhere, mostly undoing
+    change of libpng-1.2.17beta2.  Changed other "const" to "PNG_CONST"
+  Changed some handling of unused parameters, to avoid compiler warnings.
+    "if (unused == NULL) return;" becomes "unused = unused".
+Version 1.2.19beta2 [May 18, 2007]
+  Only use the valid bits of tRNS value in png_do_expand() (Brian Cartier)
+Version 1.2.19beta3 [May 19, 2007]
+  Add some "png_byte" typecasts in png_check_keyword() and write new_key
+  instead of key in zTXt chunk (Kevin Ryde).
+Version 1.2.19beta4 [May 21, 2007]
+  Add png_snprintf() function and use it in place of sprint() for improved
+    defense against buffer overflows.
+Version 1.2.19beta5 [May 21, 2007]
+  Fixed png_handle_tRNS() to only use the valid bits of tRNS value.
+  Changed handling of more unused parameters, to avoid compiler warnings.
+  Removed some PNG_CONST in pngwutil.c to avoid compiler warnings.
+Version 1.2.19beta6 [May 22, 2007]
+  Added some #ifdef PNG_MMX_CODE_SUPPORTED where needed in pngvcrd.c
+  Added a special "_MSC_VER" case that defines png_snprintf to _snprintf
+Version 1.2.19beta7 [May 22, 2007]
+  Squelched png_squelch_warnings() in pnggccrd.c and added
+    an #ifdef PNG_MMX_CODE_SUPPORTED block around the declarations that caused
+    the warnings that png_squelch_warnings was squelching.
+Version 1.2.19beta8 [May 22, 2007]
+  Removed __MMX__ from test in pngconf.h.
+Version 1.2.19beta9 [May 23, 2007]
+  Made png_squelch_warnings() available via PNG_SQUELCH_WARNINGS macro.
+  Revised png_squelch_warnings() so it might work.
+  Updated makefile.sgcc and makefile.solaris; added makefile.solaris-x86.
+Version 1.2.19beta10 [May 24, 2007]
+  Resquelched png_squelch_warnings(), use "__attribute__((used))" instead.
+Version 1.4.0beta1 [April 20, 2006]
+  Enabled iTXt support (changes png_struct, thus requires so-number change).
+  Cleaned up PNG_ASSEMBLER_CODE_SUPPORTED vs PNG_MMX_CODE_SUPPORTED
+  Eliminated PNG_1_0_X and PNG_1_2_X macros.
+  Removed deprecated functions png_read_init, png_write_init, png_info_init,
+    png_permit_empty_plte, png_set_gray_1_2_4_to_8, png_check_sig, and
+    removed the deprecated macro PNG_MAX_UINT.
+  Moved "PNG_INTERNAL" parts of png.h and pngconf.h into pngintrn.h
+  Removed many WIN32_WCE #ifdefs (Cosmin).
+  Reduced dependency on C-runtime library when on Windows (Simon-Pierre)
+  Replaced sprintf() with png_sprintf() (Simon-Pierre)
+Version 1.4.0beta2 [April 20, 2006]
+  Revised makefiles and configure to avoid making links to libpng.so.*
+  Moved some leftover MMX-related defines from pngconf.h to pngintrn.h
+  Updated scripts/pngos2.def, pngw32.def, and projects/wince/png32ce.def
+Version 1.4.0beta3 [May 10, 2006]
+  Updated scripts/pngw32.def to comment out MMX functions.
+  Added PNG_NO_GET_INT_32 and PNG_NO_SAVE_INT_32 macros.
+  Scripts/libpng.pc.in contained "configure" style version info and would
+    not work with makefiles.
+  Revised pngconf.h and added pngconf.h.in, so makefiles and configure can
+    pass defines to libpng and applications.
+Version 1.4.0beta4 [May 11, 2006]
+  Revised configure.ac, Makefile.am, and many of the makefiles to write
+    their defines in pngconf.h.
+Version 1.4.0beta5 [May 15, 2006]
+  Added a missing semicolon in Makefile.am and Makefile.in
+  Deleted extraneous square brackets from configure.ac
+Version 1.4.0beta6 [June 2, 2006]
+  Increased sprintf buffer from 50 to 52 chars in pngrutil.c to avoid
+    buffer overflow.
+  Changed sonum from 0 to 1.
+  Removed unused prototype for png_check_sig() from png.h
+Version 1.4.0beta7 [June 16, 2006]
+  Exported png_write_sig (Cosmin).
+  Optimized buffer in png_handle_cHRM() (Cosmin).
+  Set pHYs = 2835 x 2835 pixels per meter, and added
+    sCAL = 0.352778e-3 x 0.352778e-3 meters, in pngtest.png (Cosmin).
+  Added png_set_benign_errors(), png_benign_error(), png_chunk_benign_error().
+  Added typedef for png_int_32 and png_uint_32 on 64-bit systems.
+  Added "(unsigned long)" typecast on png_uint_32 variables in printf lists.
+Version 1.4.0beta8 [June 22, 2006]
+  Added demonstration of user chunk support in pngtest.c, to support the
+    public sTER chunk and a private vpAg chunk.
+Version 1.4.0beta9 [July 3, 2006]
+  Removed ordinals from scripts/pngw32.def and removed png_info_int and
+    png_set_gray_1_2_4_to_8 entries.
+  Inline call of png_get_uint_32() in png_get_uint_31().
+  Use png_get_uint_31() to get vpAg width and height in pngtest.c
+  Removed WINCE and Netware projects.
+  Removed standalone Y2KINFO file.
+Version 1.4.0beta10 [July 12, 2006]
+  Eliminated automatic copy of pngconf.h to pngconf.h.in from configure and
+    some makefiles, because it was not working reliably.  Instead, distribute
+    pngconf.h.in along with pngconf.h and cause configure and some of the
+    makefiles to update pngconf.h from pngconf.h.in.
+  Added pngconf.h to DEPENDENCIES in Makefile.am
+Version 1.4.0beta11 [August 19, 2006]
+  Removed AC_FUNC_MALLOC from configure.ac.
+  Added a warning when writing iCCP profile with mismatched profile length.
+  Patched pnggccrd.c to assemble on x86_64 platforms.
+  Moved chunk header reading into a separate function png_read_chunk_header()
+    in pngrutil.c.  The chunk header (len+sig) is now serialized in a single
+    operation (Cosmin).
+  Implemented support for I/O states. Added png_ptr member io_state, and
+    functions png_get_io_chunk_name() and png_get_io_state() in pngget.c
+    (Cosmin).
+  Added png_get_io_chunk_name and png_get_io_state to scripts/*.def (Cosmin).
+  Renamed scripts/pngw32.* to scripts/pngwin.* (Cosmin).
+  Removed the include directories and libraries from CFLAGS and LDFLAGS
+    in scripts/makefile.gcc (Cosmin).
+  Used png_save_uint_32() to set vpAg width and height in pngtest.c (Cosmin).
+  Cast to proper type when getting/setting vpAg units in pngtest.c (Cosmin).
+  Added pngintrn.h to the Visual C++ projects (Cosmin).
+  Removed scripts/list (Cosmin).
+  Updated copyright year in scripts/pngwin.def (Cosmin).
+  Removed PNG_TYPECAST_NULL and used standard NULL consistently (Cosmin).
+  Disallowed the user to redefine png_size_t, and enforced a consistent use
+    of png_size_t across libpng (Cosmin).
+  Changed the type of png_ptr->rowbytes, PNG_ROWBYTES() and friends
+    to png_size_t (Cosmin).
+  Removed png_convert_size() and replaced png_sizeof with sizeof (Cosmin).
+  Removed some unnecessary type casts (Cosmin).
+  Changed prototype of png_get_compression_buffer_size() and
+    png_set_compression_buffer_size() to work with png_size_t instead of
+    png_uint_32 (Cosmin).
+  Removed png_memcpy_check() and png_memset_check() (Cosmin).
+  Fixed a typo (png_byte --> png_bytep) in libpng.3 and libpng.txt (Cosmin).
+  Clarified that png_zalloc() does not clear the allocated memory,
+    and png_zalloc() and png_zfree() cannot be PNGAPI (Cosmin).
+  Renamed png_mem_size_t to png_alloc_size_t, fixed its definition in
+    pngconf.h, and used it in all memory allocation functions (Cosmin).
+  Renamed pngintrn.h to pngpriv.h, added a comment at the top of the file
+    mentioning that the symbols declared in that file are private, and
+    updated the scripts and the Visual C++ projects accordingly (Cosmin).
+  Removed circular references between pngconf.h and pngconf.h.in in
+    scripts/makefile.vc*win32 (Cosmin).
+  Removing trailing '.' from the warning and error messages (Cosmin).
+  Added pngdefs.h that is built by makefile or configure, instead of
+    pngconf.h.in (Glenn).
+  Detect and fix attempt to write wrong iCCP profile length.
+Version 1.4.0beta12 [October 19, 2006]
+  Changed "logical" to "bitwise" in the documentation.
+  Work around Intel-Mac compiler bug by setting PNG_NO_MMX_CODE in pngconf.h
+  Add a typecast to stifle compiler warning in pngrutil.c
+Version 1.4.0beta13 [November 10, 2006]
+  Fix potential buffer overflow in sPLT chunk handler.
+  Fix Makefile.am to not try to link to noexistent files.
+Version 1.4.0beta14 [November 15, 2006]
+  Check all exported functions for NULL png_ptr.
+Version 1.4.0beta15 [November 17, 2006]
+  Relocated two misplaced tests for NULL png_ptr.
+  Built Makefile.in with automake-1.9.6 instead of 1.9.2.
+  Build configure with autoconf-2.60 instead of 2.59
+  Add "install: all" in Makefile.am so "configure; make install" will work.
+Version 1.4.0beta16 [November 17, 2006]
+  Added a typecast in png_zalloc().
+Version 1.4.0beta17 [December 4, 2006]
+  Changed "new_key[79] = '\0';" to "(*new_key)[79] = '\0';" in pngwutil.c
+  Add "png_bytep" typecast to profile while calculating length in pngwutil.c
+Version 1.4.0beta18 [December 7, 2006]
+  Added scripts/CMakeLists.txt
+Version 1.4.0beta19 [May 16, 2007]
+  Revised scripts/CMakeLists.txt
+  Rebuilt configure and Makefile.in with newer tools.
+  Added conditional #undef jmpbuf in pngtest.c to undo #define in AIX headers.
+  Added scripts/makefile.nommx
+Version 1.4.0beta20 [July 9, 2008]
+  Moved several PNG_HAVE_* macros from pngpriv.h to png.h because applications
+    calling set_unknown_chunk_location() need them.
+  Moved several macro definitions from pngpriv.h to pngconf.h
+  Merge with changes to the 1.2.X branch, as of 1.2.30beta04.
+  Deleted all use of the MMX assembler code and Intel-licensed optimizations.
+  Revised makefile.mingw
+Version 1.4.0beta21 [July 21, 2008]
+  Moved local array "chunkdata" from pngrutil.c to the png_struct, so
+    it will be freed by png_read_destroy() in case of a read error (Kurt
+    Christensen).
+Version 1.4.0beta22 [July 21, 2008]
+  Change "purpose" and "buffer" to png_ptr->chunkdata to avoid memory leaking.
+Version 1.4.0beta23 [July 22, 2008]
+  Change "chunkdata = NULL" to "png_ptr->chunkdata = NULL" several places in
+    png_decompress_chunk().
+Version 1.4.0beta24 [July 25, 2008]
+  Change all remaining "chunkdata" to "png_ptr->chunkdata" in
+    png_decompress_chunk(), and remove "chunkdata" from parameter list.
+  Put a call to png_check_chunk_name() in png_read_chunk_header().
+  Revised png_check_chunk_name() to reject a name with a lowercase 3rd byte.
+  Removed two calls to png_check_chunk_name() occuring later in the process.
+  Define PNG_NO_ERROR_NUMBERS by default in pngconf.h
+Version 1.4.0beta25 [July 30, 2008]
+  Added a call to png_check_chunk_name() in pngpread.c
+  Reverted png_check_chunk_name() to accept a name with a lowercase 3rd byte.
+  Added png_push_have_buffer() function to pngpread.c
+  Eliminated PNG_BIG_ENDIAN_SUPPORTED and associated png_get_* macros.
+  Made inline expansion of png_get_*() optional with PNG_USE_READ_MACROS.
+  Eliminated all PNG_USELESS_TESTS and PNG_CORRECT_PALETTE_SUPPORTED code.
+  Synced contrib directory and configure files with libpng-1.2.30beta06.
+  Eliminated no-longer-used pngdefs.h (but it's still built in the makefiles)
+  Relocated a misplaced "#endif /* PNG_NO_WRITE_FILTER */" in pngwutil.c
+Version 1.4.0beta26 [August 4, 2008]
+  Removed png_push_have_buffer() function in pngpread.c.  It increased the
+    compiled library size slightly.
+  Changed "-Wall" to "-W -Wall" in the CFLAGS in all makefiles (Cosmin Truta)
+  Declared png_ptr "volatile" in pngread.c and pngwrite.c to avoid warnings.
+  Updated contrib/visupng/cexcept.h to version 2.0.1
+  Added PNG_LITERAL_CHARACTER macros for #, [, and ].
+Version 1.4.0beta27 [August 5, 2008]
+  Revised usage of PNG_LITERAL_SHARP in pngerror.c.
+  Moved newline character from individual png_debug messages into the
+    png_debug macros.
+  Allow user to #define their own png_debug, png_debug1, and png_debug2.
+Version 1.4.0beta28 [August 5, 2008]
+  Revised usage of PNG_LITERAL_SHARP in pngerror.c.
+  Added PNG_STRING_NEWLINE macro
+Version 1.4.0beta29 [August 9, 2008]
+  Revised usage of PNG_STRING_NEWLINE to work on non-ISO compilers.
+  Added PNG_STRING_COPYRIGHT macro.
+  Added non-ISO versions of png_debug macros.
+Version 1.4.0beta30 [August 14, 2008]
+  Added premultiplied alpha feature (Volker Wiendl).
+Version 1.4.0beta31 [August 18, 2008]
+  Moved png_set_premultiply_alpha from pngtrans.c to pngrtran.c
+  Removed extra crc check at the end of png_handle_cHRM().  Bug introduced
+    in libpng-1.4.0beta20.
+Version 1.4.0beta32 [August 19, 2008]
+  Added PNG_WRITE_FLUSH_SUPPORTED block around new png_flush() call.
+  Revised PNG_NO_STDIO version of png_write_flush()
+Version 1.4.0beta33 [August 20, 2008]
+  Added png_get|set_chunk_cache_max() to limit the total number of sPLT,
+    text, and unknown chunks that can be stored.
+Version 1.4.0beta34 [September 6, 2008]
+  Shortened tIME_string to 29 bytes in pngtest.c
+  Fixed off-by-one error introduced in png_push_read_zTXt() function in
+    libpng-1.2.30beta04/pngpread.c (Harald van Dijk)
+Version 1.4.0beta35 [October 6, 2008]
+  Changed "trans_values" to "trans_color".
+  Changed so-number from 0 to 14.  Some OS do not like 0.
+  Revised makefile.darwin to fix shared library numbering.
+  Change png_set_gray_1_2_4_to_8() to png_set_expand_gray_1_2_4_to_8()
+    in example.c (debian bug report)
+Version 1.4.0beta36 [October 25, 2008]
+  Sync with tEXt vulnerability fix in libpng-1.2.33rc02.
+Version 1.4.0beta37 [November 13, 2008]
+  Added png_check_cHRM in png.c and moved checking from pngget.c, pngrutil.c,
+    and pngwrite.c
+Version 1.4.0beta38 [November 22, 2008]
+  Added check for zero-area RGB cHRM triangle in png_check_cHRM() and
+    png_check_cHRM_fixed().
+Version 1.4.0beta39 [November 23, 2008]
+  Revised png_warning() to write its message on standard output by default
+    when warning_fn is NULL.
+Version 1.4.0beta40 [November 24, 2008]
+  Eliminated png_check_cHRM().  Instead, always use png_check_cHRM_fixed().
+  In png_check_cHRM_fixed(), ensure white_y is > 0, and removed redundant
+    check for all-zero coordinates that is detected by the triangle check.
+Version 1.4.0beta41 [November 26, 2008]
+  Fixed string vs pointer-to-string error in png_check_keyword().
+  Rearranged test expressions in png_check_cHRM_fixed() to avoid internal
+    overflows.
+  Added PNG_NO_CHECK_cHRM conditional.
+Version 1.4.0beta42, 43 [December 1, 2008]
+  Merge png_debug with version 1.2.34beta04.
+Version 1.4.0beta44 [December 6, 2008]
+  Removed redundant check for key==NULL before calling png_check_keyword()
+    to ensure that new_key gets initialized and removed extra warning
+    (Merge with version 1.2.34beta05 -- Arvan Pritchard).
+Version 1.4.0beta45 [December 9, 2008]
+  In png_write_png(), respect the placement of the filler bytes in an earlier
+    call to png_set_filler() (Jim Barry).
+Version 1.4.0beta46 [December 10, 2008]
+  Undid previous change and added PNG_TRANSFORM_STRIP_FILLER_BEFORE and
+    PNG_TRANSFORM_STRIP_FILLER_AFTER conditionals and deprecated
+    PNG_TRANSFORM_STRIP_FILLER (Jim Barry).
+Version 1.4.0beta47 [December 15, 2008]
+  Support for dithering was disabled by default, because it has never
+    been well tested and doesn't work very well.  The code has not
+    been removed, however, and can be enabled by building libpng with
+    PNG_READ_DITHER_SUPPORTED defined.
+Version 1.4.0beta48 [February 14, 2009]
+  Added new exported function png_calloc().
+  Combined several instances of png_malloc(); png_memset() into png_calloc().
+  Removed prototype for png_freeptr() that was added in libpng-1.4.0beta24
+    but was never defined.
+Version 1.4.0beta49 [February 28, 2009]
+  Added png_fileno() macro to pngconf.h, used in pngwio.c
+  Corrected order of #ifdef's in png_debug definition in png.h
+  Fixed bug introduced in libpng-1.4.0beta48 with the memset arguments
+    for pcal_params.
+  Fixed order of #ifdef directives in the png_debug defines in png.h
+    (bug introduced in libpng-1.2.34/1.4.0beta29).
+  Revised comments in png_set_read_fn() and png_set_write_fn().
+Version 1.4.0beta50 [March 18, 2009]
+  Use png_calloc() instead of png_malloc() to allocate big_row_buf when
+    reading an interlaced file, to avoid a possible UMR.
+  Undid revision of PNG_NO_STDIO version of png_write_flush().  Users
+    having trouble with fflush() can build with PNG_NO_WRITE_FLUSH defined
+    or supply their own flush_fn() replacement.
+  Revised libpng*.txt and png.h documentation about use of png_write_flush()
+    and png_set_write_fn().
+  Removed fflush() from pngtest.c.
+  Added "#define PNG_NO_WRITE_FLUSH" to contrib/pngminim/encoder/pngusr.h
+Version 1.4.0beta51 [March 21, 2009]
+  Removed new png_fileno() macro from pngconf.h .
+Version 1.4.0beta52 [March 27, 2009]
+  Relocated png_do_chop() ahead of building gamma tables in pngrtran.c
+    This avoids building 16-bit gamma tables unnecessarily.
+  Removed fflush() from pngtest.c.
+  Added "#define PNG_NO_WRITE_FLUSH" to contrib/pngminim/encoder/pngusr.h
+  Added a section on differences between 1.0.x and 1.2.x to libpng.3/libpng.txt
+Version 1.4.0beta53 [April 1, 2009]
+  Removed some remaining MMX macros from pngpriv.h
+  Fixed potential memory leak of "new_name" in png_write_iCCP() (Ralph Giles)
+Version 1.4.0beta54 [April 13, 2009]
+  Added "ifndef PNG_SKIP_SETJMP_CHECK" block in pngconf.h to allow
+    application code writers to bypass the check for multiple inclusion
+    of setjmp.h when they know that it is safe to ignore the situation.
+  Eliminated internal use of setjmp() in pngread.c and pngwrite.c
+  Reordered ancillary chunks in pngtest.png to be the same as what
+    pngtest now produces, and made some cosmetic changes to pngtest output.
+  Eliminated deprecated png_read_init_3() and png_write_init_3() functions.
+Version 1.4.0beta55 [April 15, 2009]
+  Simplified error handling in pngread.c and pngwrite.c by putting
+    the new png_read_cleanup() and png_write_cleanup() functions inline.
+Version 1.4.0beta56 [April 25, 2009]
+  Renamed "user_chunk_data" to "my_user_chunk_data" in pngtest.c to suppress
+    "shadowed declaration" warning from gcc-4.3.3.
+  Renamed "gamma" to "png_gamma" in pngset.c to avoid "shadowed declaration"
+    warning about a global "gamma" variable in math.h on some platforms.
+Version 1.4.0beta57 [May 2, 2009]
+  Removed prototype for png_freeptr() that was added in libpng-1.4.0beta24
+    but was never defined (again).
+  Rebuilt configure scripts with autoconf-2.63 instead of 2.62
+  Removed pngprefs.h and MMX from makefiles
+Version 1.4.0beta58 [May 14, 2009]
+  Changed pngw32.def to pngwin.def in makefile.mingw (typo was introduced
+    in beta57).
+  Clarified usage of sig_bit versus sig_bit_p in example.c (Vincent Torri)
+Version 1.4.0beta59 [May 15, 2009]
+  Reformated sources in libpng style (3-space intentation, comment format)
+  Fixed typo in libpng docs (PNG_FILTER_AVE should be PNG_FILTER_AVG)
+  Added sections about the git repository and our coding style to the
+    documentation
+  Relocated misplaced #endif in pngwrite.c, sCAL chunk handler.
+Version 1.4.0beta60 [May 19, 2009]
+  Conditionally compile png_read_finish_row() which is not used by
+    progressive readers.
+  Added contrib/pngminim/preader to demonstrate building minimal progressive
+    decoder, based on contrib/gregbook with embedded libpng and zlib.
+Version 1.4.0beta61 [May 20, 2009]
+  In contrib/pngminim/*, renamed "makefile.std" to "makefile", since there
+    is only one makefile in those directories, and revised the README files
+    accordingly.
+  More reformatting of comments, mostly to capitalize sentences.
+Version 1.4.0beta62 [June 2, 2009]
+  Added "#define PNG_NO_WRITE_SWAP" to contrib/pngminim/encoder/pngusr.h
+    and "define PNG_NO_READ_SWAP" to decoder/pngusr.h and preader/pngusr.h
+  Reformatted several remaining "else statement" into two lines.
+  Added a section to the libpng documentation about using png_get_io_ptr()
+    in configure scripts to detect the presence of libpng.
+Version 1.4.0beta63 [June 15, 2009]
+  Revised libpng*.txt and libpng.3 to mention calling png_set_IHDR()
+    multiple times and to specify the sample order in the tRNS chunk,
+    because the ISO PNG specification has a typo in the tRNS table.
+  Changed several PNG_UNKNOWN_CHUNK_SUPPORTED to
+    PNG_HANDLE_AS_UNKNOWN_SUPPORTED, to make the png_set_keep mechanism
+    available for ignoring known chunks even when not saving unknown chunks.
+  Adopted preference for consistent use of "#ifdef" and "#ifndef" versus
+    "#if defined()" and "if !defined()" where possible.
+Version 1.4.0beta64 [June 24, 2009]
+  Eliminated PNG_LEGACY_SUPPORTED code.
+  Moved the various unknown chunk macro definitions outside of the
+     PNG_READ|WRITE_ANCILLARY_CHUNK_SUPPORTED blocks.
+Version 1.4.0beta65 [June 26, 2009]
+  Added a reference to the libpng license in each file.
+Version 1.4.0beta66 [June 27, 2009]
+  Refer to the libpng license instead of the libpng license in each file.
+Version 1.4.0beta67 [July 6, 2009]
+  Relocated INVERT_ALPHA within png_read_png() and png_write_png().
+  Added high-level API transform PNG_TRANSFORM_GRAY_TO_RGB.
+  Added an "xcode" project to the projects directory (Alam Arias).
+Version 1.4.0beta68 [July 19, 2009]
+  Avoid some tests in filter selection in pngwutil.c
+Version 1.4.0beta69 [July 25, 2009]
+  Simplified the new filter-selection test.  This runs faster in the
+    common "PNG_ALL_FILTERS" and PNG_FILTER_NONE cases.
+  Removed extraneous declaration from the new call to png_read_gray_to_rgb()
+    (bug introduced in libpng-1.4.0beta67).
+  Fixed up xcode project (Alam Arias)
+  Added a prototype for png_64bit_product() in png.c
+Version 1.4.0beta70 [July 27, 2009]
+  Avoid a possible NULL dereference in debug build, in png_set_text_2().
+    (bug introduced in libpng-0.95, discovered by Evan Rouault)
+Version 1.4.0beta71 [July 29, 2009]
+  Rebuilt configure scripts with autoconf-2.64.
+Version 1.4.0beta72 [August 1, 2009]
+  Replaced *.tar.lzma with *.tar.xz in distribution.  Get the xz codec
+    from <http://tukaani.org/xz>.
+Version 1.4.0beta73 [August 1, 2009]
+  Reject attempt to write iCCP chunk with negative embedded profile length
+    (JD Chen) (CVE-2009-5063).
+Version 1.4.0beta74 [August 8, 2009]
+  Changed png_ptr and info_ptr member "trans" to "trans_alpha".
+Version 1.4.0beta75 [August 21, 2009]
+  Removed an extra png_debug() recently added to png_write_find_filter().
+  Fixed incorrect #ifdef in pngset.c regarding unknown chunk support.
+Version 1.4.0beta76 [August 22, 2009]
+  Moved an incorrectly located test in png_read_row() in pngread.c
+Version 1.4.0beta77 [August 27, 2009]
+  Removed lpXYZ.tar.bz2 (with CRLF), KNOWNBUG, libpng-x.y.z-KNOWNBUG.txt,
+    and the "noconfig" files from the distribution.
+  Moved CMakeLists.txt from scripts into the main libpng directory.
+  Various bugfixes and improvements to CMakeLists.txt (Philip Lowman)
+Version 1.4.0beta78 [August 31, 2009]
+  Converted all PNG_NO_* tests to PNG_*_SUPPORTED everywhere except pngconf.h
+  Eliminated PNG_NO_FREE_ME and PNG_FREE_ME_SUPPORTED macros.
+  Use png_malloc plus a loop instead of png_calloc() to initialize
+    row_pointers in png_read_png().
+Version 1.4.0beta79 [September 1, 2009]
+  Eliminated PNG_GLOBAL_ARRAYS and PNG_LOCAL_ARRAYS; always use local arrays.
+  Eliminated PNG_CALLOC_SUPPORTED macro and always provide png_calloc().
+Version 1.4.0beta80 [September 17, 2009]
+  Removed scripts/libpng.icc
+  Changed typecast of filler from png_byte to png_uint_16 in png_set_filler().
+    (Dennis Gustafsson)
+  Fixed typo introduced in beta78 in pngtest.c ("#if def " should be "#ifdef ")
+Version 1.4.0beta81 [September 23, 2009]
+  Eliminated unused PNG_FLAG_FREE_* defines from pngpriv.h
+  Expanded TAB characters in pngrtran.c
+  Removed PNG_CONST from all "PNG_CONST PNG_CHNK" declarations to avoid
+    compiler complaints about doubly declaring things "const".
+  Changed all "#if [!]defined(X)" to "if[n]def X" where possible.
+  Eliminated unused png_ptr->row_buf_size
+Version 1.4.0beta82 [September 25, 2009]
+  Moved redundant IHDR checking into new png_check_IHDR() in png.c
+    and report all errors found in the IHDR data.
+  Eliminated useless call to png_check_cHRM() from pngset.c
+Version 1.4.0beta83 [September 25, 2009]
+  Revised png_check_IHDR() to eliminate bogus complaint about filter_type.
+Version 1.4.0beta84 [September 30, 2009]
+  Fixed some inconsistent indentation in pngconf.h
+  Revised png_check_IHDR() to add a test for width variable less than 32-bit.
+Version 1.4.0beta85 [October 1, 2009]
+  Revised png_check_IHDR() again, to check info_ptr members instead of
+    the contents of the returned parameters.
+Version 1.4.0beta86 [October 9, 2009]
+  Updated the "xcode" project (Alam Arias).
+  Eliminated a shadowed declaration of "pp" in png_handle_sPLT().
+Version 1.4.0rc01 [October 19, 2009]
+  Trivial cosmetic changes.
+Version 1.4.0beta87 [October 30, 2009]
+  Moved version 1.4.0 back into beta.
+Version 1.4.0beta88 [October 30, 2009]
+  Revised libpng*.txt section about differences between 1.2.x and 1.4.0
+    because most of the new features have now been ported back to 1.2.41
+Version 1.4.0beta89 [November 1, 2009]
+  More bugfixes and improvements to CMakeLists.txt (Philip Lowman)
+  Removed a harmless extra png_set_invert_alpha() from pngwrite.c
+  Apply png_user_chunk_cache_max within png_decompress_chunk().
+  Merged libpng-1.2.41.txt with libpng-1.4.0.txt where appropriate.
+Version 1.4.0beta90 [November 2, 2009]
+  Removed all remaining WIN32_WCE #ifdefs except those involving the
+    time.h "tm" structure
+Version 1.4.0beta91 [November 3, 2009]
+  Updated scripts/pngw32.def and projects/wince/png32ce.def
+  Copied projects/wince/png32ce.def to the scripts directory.
+  Added scripts/makefile.wce
+  Patched ltmain.sh for wince support.
+  Added PNG_CONVERT_tIME_SUPPORTED macro.
+Version 1.4.0beta92 [November 4, 2009]
+  Make inclusion of time.h in pngconf.h depend on PNG_CONVERT_tIME_SUPPORTED
+  Make #define PNG_CONVERT_tIME_SUPPORTED depend on PNG_WRITE_tIME_SUPPORTED
+  Revised libpng*.txt to describe differences from 1.2.40 to 1.4.0 (instead
+    of differences from 1.2.41 to 1.4.0)
+Version 1.4.0beta93 [November 7, 2009]
+  Added PNG_DEPSTRUCT, PNG_DEPRECATED, PNG_USE_RESULT, PNG_NORETURN, and
+    PNG_ALLOCATED macros to detect deprecated direct access to the
+    png_struct or info_struct members and other deprecated usage in
+    applications (John Bowler).
+  Updated scripts/makefile* to add "-DPNG_CONFIGURE_LIBPNG" to CFLAGS,
+    to prevent warnings about direct access to png structs by libpng
+    functions while building libpng.  They need to be tested, especially
+    those using compilers other than gcc.
+  Updated projects/visualc6 and visualc71 with "/d PNG_CONFIGURE_LIBPNG".
+    They should work but still need to be updated to remove
+    references to pnggccrd.c or pngvcrd.c and ASM building.
+  Added README.txt to the beos, cbuilder5, netware, and xcode projects warning
+    that they need to be updated, to remove references to pnggccrd.c and
+    pngvcrd.c and to depend on pngpriv.h
+  Removed three direct references to read_info_ptr members in pngtest.c
+    that were detected by the new PNG_DEPSTRUCT macro.
+  Moved the png_debug macro definitions and the png_read_destroy(),
+    png_write_destroy() and png_far_to_near() prototypes from png.h
+    to pngpriv.h (John Bowler)
+  Moved the synopsis lines for png_read_destroy(), png_write_destroy()
+    png_debug(), png_debug1(), and png_debug2() from libpng.3 to libpngpf.3.
+Version 1.4.0beta94 [November 9, 2009]
+  Removed the obsolete, unused pnggccrd.c and pngvcrd.c files.
+  Updated CMakeLists.txt to add "-DPNG_CONFIGURE_LIBPNG" to the definitions.
+  Removed dependency of pngtest.o on pngpriv.h in the makefiles.
+  Only #define PNG_DEPSTRUCT, etc. in pngconf.h if not already defined.
+Version 1.4.0beta95 [November 10, 2009]
+  Changed png_check_sig() to !png_sig_cmp() in contrib programs.
+  Added -DPNG_CONFIGURE_LIBPNG to contrib/pngminm/*/makefile
+  Changed png_check_sig() to !png_sig_cmp() in contrib programs.
+  Corrected the png_get_IHDR() call in contrib/gregbook/readpng2.c
+  Changed pngminim/*/gather.sh to stop trying to remove pnggccrd.c and pngvcrd.c
+  Added dependency on pngpriv.h in contrib/pngminim/*/makefile
+Version 1.4.0beta96 [November 12, 2009]
+  Renamed scripts/makefile.wce to scripts/makefile.cegcc
+  Revised Makefile.am to use libpng.sys while building libpng.so
+    so that only PNG_EXPORT functions are exported.
+  Removed the deprecated png_check_sig() function/macro.
+  Removed recently removed function names from scripts/*.def
+  Revised pngtest.png to put chunks in the same order written by pngtest
+    (evidently the same change made in libpng-1.0beta54 was lost).
+  Added PNG_PRIVATE macro definition in pngconf.h for possible future use.
+Version 1.4.0beta97 [November 13, 2009]
+  Restored pngtest.png to the libpng-1.4.0beta7 version.
+  Removed projects/beos and netware.txt; no one seems to be supporting them.
+  Revised Makefile.in
+Version 1.4.0beta98 [November 13, 2009]
+  Added the "xcode" project to zip distributions,
+  Fixed a typo in scripts/pngwin.def introduced in beta97.
+Version 1.4.0beta99 [November 14, 2009]
+  Moved libpng-config.in and libpng.pc-configure.in out of the scripts
+    directory, to libpng-config.in and libpng-pc.in, respectively, and
+    modified Makefile.am and configure.ac accordingly.  Now "configure"
+    needs nothing from the "scripts" directory.
+  Avoid redefining PNG_CONST in pngconf.h
+Version 1.4.0beta100 [November 14, 2009]
+  Removed ASM builds from projects/visualc6 and projects/visualc71
+  Removed scripts/makefile.nommx and makefile.vcawin32
+  Revised CMakeLists.txt to account for new location of libpng-config.in
+    and libpng-pc.in
+  Updated INSTALL to reflect removal and relocation of files.
+Version 1.4.0beta101 [November 14, 2009]
+  Restored the binary files (*.jpg, *.png, some project files) that were
+    accidentally deleted from the zip and 7z distributions when the xcode
+    project was added.
+Version 1.4.0beta102 [November 18, 2009]
+  Added libpng-config.in and libpng-pc.in to the zip and 7z distributions.
+  Fixed a typo in projects/visualc6/pngtest.dsp, introduced in beta100.
+  Moved descriptions of makefiles and other scripts out of INSTALL into
+    scripts/README.txt
+  Updated the copyright year in scripts/pngwin.rc from 2006 to 2009.
+Version 1.4.0beta103 [November 21, 2009]
+  Removed obsolete comments about ASM from projects/visualc71/README_zlib.txt
+  Align row_buf on 16-byte boundary in memory.
+  Restored the PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED guard around the call
+    to png_flush() after png_write_IEND().  See 1.4.0beta32, 1.4.0beta50
+    changes above and 1.2.30, 1.2.30rc01 and rc03 in 1.2.41 CHANGES.  Someone
+    needs this feature.
+  Make the 'png_jmpbuf' macro expand to a call that records the correct
+    longjmp function as well as returning a pointer to the setjmp
+    jmp_buf buffer, and marked direct access to jmpbuf 'deprecated'.
+    (John Bowler)
+Version 1.4.0beta104 [November 22, 2009]
+  Removed png_longjmp_ptr from scripts/*.def and libpng.3
+  Rebuilt configure scripts with autoconf-2.65
+Version 1.4.0beta105 [November 25, 2009]
+  Use fast integer PNG_DIVIDE_BY_255() or PNG_DIVIDE_BY_65535()
+    to accomplish alpha premultiplication when
+    PNG_READ_COMPOSITE_NODIV_SUPPORTED is defined.
+  Changed "/255" to "/255.0" in background calculations to make it clear
+    that the 255 is used as a double.
+Version 1.4.0beta106 [November 27, 2009]
+  Removed premultiplied alpha feature.
+Version 1.4.0beta107 [December 4, 2009]
+  Updated README
+  Added "#define PNG_NO_PEDANTIC_WARNINGS" in the libpng source files.
+  Removed "-DPNG_CONFIGURE_LIBPNG" from the makefiles and projects.
+  Revised scripts/makefile.netbsd, makefile.openbsd, and makefile.sco
+    to put png.h and pngconf.h in $prefix/include, like the other scripts,
+    instead of in $prefix/include/libpng.  Also revised makefile.sco
+    to put them in $prefix/include/libpng15 instead of in
+    $prefix/include/libpng/libpng15.
+Version 1.4.0beta108 [December 11, 2009]
+  Removed leftover "-DPNG_CONFIGURE_LIBPNG" from contrib/pngminim/*/makefile
+  Relocated png_do_chop() to its original position in pngrtran.c; the
+    change in version 1.2.41beta08 caused transparency to be handled wrong
+    in some 16-bit datastreams (Yusaku Sugai).
+Version 1.4.0beta109 [December 13, 2009]
+  Added "bit_depth" parameter to the private png_build_gamma_table() function.
+  Pass bit_depth=8 to png_build_gamma_table() when bit_depth is 16 but the
+    PNG_16_TO_8 transform has been set, to avoid unnecessary build of 16-bit
+    tables.
+Version 1.4.0rc02 [December 20, 2009]
+  Declared png_cleanup_needed "volatile" in pngread.c and pngwrite.c
+Version 1.4.0rc03 [December 22, 2009]
+  Renamed libpng-pc.in back to libpng.pc.in and revised CMakeLists.txt
+    (revising the change in 1.4.0beta99)
+Version 1.4.0rc04 [December 25, 2009]
+  Swapped PNG_UNKNOWN_CHUNKS_SUPPORTED and PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+    in pngset.c to be consistent with other changes in version 1.2.38.
+Version 1.4.0rc05 [December 25, 2009]
+  Changed "libpng-pc.in" to "libpng.pc.in" in configure.ac, configure, and
+    Makefile.in to be consistent with changes in libpng-1.4.0rc03
+Version 1.4.0rc06 [December 29, 2009]
+  Reverted the gamma_table changes from libpng-1.4.0beta109.
+  Fixed some indentation errors.
+Version 1.4.0rc07 [January 1, 2010]
+  Revised libpng*.txt and libpng.3 about 1.2.x->1.4.x differences.
+  Use png_calloc() instead of png_malloc(); png_memset() in pngrutil.c
+  Update copyright year to 2010.
+Version 1.4.0rc08 [January 2, 2010]
+  Avoid deprecated references to png_ptr-io_ptr and png_ptr->error_ptr
+    in pngtest.c
+Version 1.4.0 [January 3, 2010]
+  No changes.
+Version 1.4.1beta01 [January 8, 2010]
+  Updated CMakeLists.txt for consistent indentation and to avoid an
+    unclosed if-statement warning (Philip Lowman).
+  Revised Makefile.am and Makefile.in to remove references to Y2KINFO,
+    KNOWNBUG, and libpng.la (Robert Schwebel).
+  Revised the makefiles to install the same files and symbolic
+    links as configure, except for libpng.la and libpng14.la.
+  Make png_set|get_compression_buffer_size() available even when
+    PNG_WRITE_SUPPORTED is not enabled.
+  Revised Makefile.am and Makefile.in to simplify their maintenance.
+  Revised scripts/makefile.linux to install a link to libpng14.so.14.1
+Version 1.4.1beta02 [January 9, 2010]
+  Revised the rest of the makefiles to install a link to libpng14.so.14.1
+Version 1.4.1beta03 [January 10, 2010]
+  Removed png_set_premultiply_alpha() from scripts/*.def
+Version 1.4.1rc01 [January 16, 2010]
+  No changes.
+Version 1.4.1beta04 [January 23, 2010]
+  Revised png_decompress_chunk() to improve speed and memory usage when
+    decoding large chunks.
+  Added png_set|get_chunk_malloc_max() functions.
+Version 1.4.1beta05 [January 26, 2010]
+  Relocated "int k" declaration in pngtest.c to minimize its scope.
+Version 1.4.1beta06 [January 28, 2010]
+  Revised png_decompress_chunk() to use a two-pass method suggested by
+    John Bowler.
+Version 1.4.1beta07 [February 6, 2010]
+  Folded some long lines in the source files.
+  Added defineable PNG_USER_CHUNK_CACHE_MAX, PNG_USER_CHUNK_MALLOC_MAX,
+    and a PNG_USER_LIMITS_SUPPORTED flag.
+  Eliminated use of png_ptr->irowbytes and reused the slot in png_ptr as
+    png_ptr->png_user_chunk_malloc_max.
+  Revised png_push_save_buffer() to do fewer but larger png_malloc() calls.
+Version 1.4.1beta08 [February 6, 2010]
+  Minor cleanup and updating of dates and copyright year.
+Version 1.5.0beta01 [February 7, 2010]
+  Moved declaration of png_struct into private pngstruct.h and png_info
+    into pnginfo.h
+Version 1.4.1beta09 and 1.5.0beta02 [February 7, 2010]
+  Reverted to original png_push_save_buffer() code.
+Version 1.4.1beta10 and 1.5.0beta03 [February 8, 2010]
+  Return allocated "old_buffer" in png_push_save_buffer() before
+    calling png_error(), to avoid a potential memory leak.
+  Updated configure script to use SO number 15.
+Version 1.5.0beta04 [February 9, 2010]
+  Removed malformed "incomplete struct declaration" of png_info from png.h
+Version 1.5.0beta05 [February 12, 2010]
+  Removed PNG_DEPSTRUCT markup in pngstruct.h and pnginfo.h, and undid the
+    linewrapping that it entailed.
+  Revised comments in pngstruct.h and pnginfo.h and added pointers to
+    the libpng license.
+  Changed PNG_INTERNAL to PNG_EXPOSE_INTERNAL_STRUCTURES
+  Removed the cbuilder5 project, which has not been updated to 1.4.0.
+Version 1.4.1beta12 and 1.5.0beta06 [February 14, 2010]
+  Fixed type declaration of png_get_chunk_malloc_max() in pngget.c (Daisuke
+    Nishikawa)
+Version 1.5.0beta07 [omitted]
+Version 1.5.0beta08 [February 19, 2010]
+  Changed #ifdef PNG_NO_STDIO_SUPPORTED to #ifdef PNG_NO_CONSOLE_IO_SUPPORTED
+    wherever png_snprintf() is used to construct error and warning messages.
+  Noted in scripts/makefile.mingw that it expects to be run under MSYS.
+  Removed obsolete unused MMX-querying support from contrib/gregbook
+  Added exported png_longjmp() function.
+  Removed the AIX redefinition of jmpbuf in png.h
+  Added -D_ALLSOURCE in configure.ac, makefile.aix, and CMakeLists.txt
+    when building on AIX.
+Version 1.5.0beta09 [February 19, 2010]
+  Removed -D_ALLSOURCE from configure.ac, makefile.aix, and CMakeLists.txt.
+  Changed the name of png_ptr->jmpbuf to png_ptr->png_jmpbuf in pngstruct.h
+Version 1.5.0beta10 [February 25, 2010]
+  Removed unused gzio.c from contrib/pngminim gather and makefile scripts
+  Removed replacement error handlers from contrib/gregbook.  Because of
+    the new png_longjmp() function they are no longer needed.
+Version 1.5.0beta11 [March 6, 2010]
+  Removed checking for already-included setjmp.h from pngconf.h
+  Fixed inconsistent indentations and made numerous cosmetic changes.
+  Revised the "SEE ALSO" style of libpng.3, libpngpf.3, and png.5
+Version 1.5.0beta12 [March 9, 2010]
+  Moved "#include png.h" inside pngpriv.h and removed "#include png.h" from
+    the source files, along with "#define PNG_EXPOSE_INTERNAL_STRUCTURES"
+    and "#define PNG_NO_PEDANTIC_WARNINGS" (John Bowler).
+  Created new pngdebug.h and moved debug definitions there.
+Version 1.5.0beta13 [March 10, 2010]
+  Protect pngstruct.h, pnginfo.h, and pngdebug.h from being included twice.
+  Revise the "#ifdef" blocks in png_inflate() so it will compile when neither
+    PNG_USER_CHUNK_MALLOC_MAX nor PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED
+    is defined.
+  Removed unused png_measure_compressed_chunk() from pngpriv.h and libpngpf.3
+  Moved the 'config.h' support from pngconf.h to pngpriv.h
+  Removed PNGAPI from the png_longjmp_ptr typedef.
+  Eliminated dependence of pngtest.c on the private pngdebug.h file.
+  Make all png_debug macros into *unterminated* statements or
+    expressions (i.e. a trailing ';' must always be added) and correct
+    the format statements in various png_debug messages.
+Version 1.5.0beta14 [March 14, 2010]
+  Removed direct access to png_ptr->io_ptr from the Windows code in pngtest.c
+  Revised Makefile.am to account for recent additions and replacements.
+  Corrected CE and OS/2 DEF files (scripts/png*def) for symbols removed and
+    added ordinal numbers to the Windows DEF file and corrected the duplicated
+    ordinal numbers on CE symbols that are commented out.
+  Added back in export symbols that can be present in the Windows build but
+    are disabled by default.
+  PNG_EXPORT changed to include an 'ordinal' field for DEF file generation.
+    PNG_CALLBACK added to make callback definitions uniform.  PNGAPI split
+    into PNGCAPI (base C form), PNGAPI (exports) and PNGCBAPI (callbacks),
+    and appropriate changes made to all files.  Cygwin builds re-hinged to
+    allow procedure call standard changes and to remove the need for the DEF
+    file (fixes build on Cygwin).
+  Enabled 'attribute' warnings that are relevant to library APIs and callbacks.
+  Changed rules for generation of the various symbol files and added a new
+    rule for a DEF file (which is also added to the distribution).
+  Updated the symbol file generation to stop it adding spurious spaces
+    to EOL (coming from preprocessor macro expansion).  Added a facility
+    to join tokens in the output and rewrite *.dfn to use this.
+  Eliminated scripts/*.def in favor of libpng.def; updated projects/visualc71
+    and removed scripts/makefile.cygwin.
+  Made PNG_BUILD_DLL safe: it can be set whenever a DLL is being built.
+  Removed the include of sys/types.h - apparently unnecessary now on the
+    platforms on which it happened (all but Mac OS and RISC OS).
+  Moved the Mac OS test into pngpriv.h (the only place it is used.)
+Version 1.5.0beta15 [March 17, 2010]
+  Added symbols.chk target to Makefile.am to validate the symbols in png.h
+    against the new DEF file scripts/symbols.def.
+  Changed the default DEF file back to pngwin.def.
+  Removed makefile.mingw.
+  Eliminated PNG_NO_EXTERN and PNG_ALL_EXTERN
+Version 1.5.0beta16 [April 1, 2010]
+  Make png_text_struct independent of PNG_iTXt_SUPPORTED, so that
+    fields are initialized in all configurations.  The READ/WRITE
+    macros (PNG_(READ|WRITE)_iTXt_SUPPORTED) still function as
+    before to disable code to actually read or write iTXt chunks
+    and iTXt_SUPPORTED can be used to detect presence of either
+    read or write support (but it is probably better to check for
+    the one actually required - read or write.)
+  Combined multiple png_warning() calls for a single error.
+  Restored the macro definition of png_check_sig().
+Version 1.5.0beta17 [April 17, 2010]
+  Added some "(long)" typecasts to printf calls in png_handle_cHRM().
+  Documented the fact that png_set_dither() was disabled since libpng-1.4.0.
+  Reenabled png_set_dither() but renamed it to png_set_quantize() to reflect
+    more accurately what it actually does.  At the same time, renamed
+    the PNG_DITHER_[RED,GREEN_BLUE]_BITS macros to
+    PNG_QUANTIZE_[RED,GREEN,BLUE]_BITS.
+  Added some "(long)" typecasts to printf calls in png_handle_cHRM().
+  Freeze build-time only configuration in the build.
+    In all prior versions of libpng most configuration options
+    controlled by compiler #defines had to be repeated by the
+    application code that used libpng.  This patch changes this
+    so that compilation options that can only be changed at build
+    time are frozen in the build.  Options that are compiler
+    dependent (and those that are system dependent) are evaluated
+    each time - pngconf.h holds these.  Options that can be changed
+    per-file in the application are in png.h.  Frozen options are
+    in the new installed header file pnglibconf.h (John Bowler)
+  Removed the xcode project because it has not been updated to work
+    with libpng-1.5.0.
+  Removed the ability to include optional pngusr.h
+Version 1.5.0beta18 [April 17, 2010]
+  Restored the ability to include optional pngusr.h
+  Moved replacements for png_error() and png_warning() from the
+    contrib/pngminim project to pngerror.c, for use when warnings or
+    errors are disabled via PNG_NO_WARN or PNG_NO_ERROR_TEXT, to avoid
+    storing unneeded error/warning text.
+  Updated contrib/pngminim project to work with the new pnglibconf.h
+  Added some PNG_NO_* defines to contrib/pngminim/*/pngusr.h to save space.
+Version 1.5.0beta19 [April 24, 2010]
+  Added PNG_{READ,WRITE}_INT_FUNCTIONS_SUPPORTED.  This allows the functions
+    to read and write ints to be disabled independently of PNG_USE_READ_MACROS,
+    which allows libpng to be built with the functions even though the default
+    is to use the macros - this allows applications to choose at app build
+    time whether or not to use macros (previously impossible because the
+    functions weren't in the default build.)
+  Changed Windows calling convention back to __cdecl for API functions.
+    For Windows/x86 platforms only:
+      __stdcall is no longer needed for Visual Basic, so libpng-1.5.0 uses
+      __cdecl throughout (both API functions and callbacks) on Windows/x86
+      platforms.
+  Replaced visualc6 and visualc71 projects with new vstudio project
+  Relaxed the overly-restrictive permissions of some files.
+Version 1.5.0beta20 [April 24, 2010]
+  Relaxed more overly-restrictive permissions of some files.
+Version 1.5.0beta21 [April 27, 2010]
+  Removed some unwanted binary bytes and changed CRLF to NEWLINE in the new
+    vstudio project files, and some trivial editing of some files in the
+    scripts directory.
+  Set PNG_NO_READ_BGR, PNG_NO_IO_STATE, and PNG_NO_TIME_RFC1123 in
+    contrib/pngminim/decoder/pngusr.h to make a smaller decoder application.
+Version 1.5.0beta22 [April 28, 2010]
+  Fixed dependencies of GET_INT_32 - it does not require READ_INT_FUNCTIONS
+    because it has a macro equivalent.
+  Improved the options.awk script; added an "everything off" option.
+  Revised contrib/pngminim to use the "everything off" option in pngusr.dfa.
+Version 1.5.0beta23 [April 29, 2010]
+  Corrected PNG_REMOVED macro to take five arguments.
+    The macro was documented with two arguments (name,ordinal), however
+    the symbol checking .dfn files assumed five arguments.  The five
+    argument form seems more useful so it is changed to that.
+  Corrected PNG_UNKNOWN_CHUNKS_SUPPORTED to PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+    in gregbook/readpng2.c
+  Corrected protection of png_get_user_transform_ptr. The API declaration in
+    png.h is removed if both READ and WRITE USER_TRANSFORM are turned off
+    but was left defined in pngtrans.c
+  Added logunsupported=1 to cause pnglibconf.h to document disabled options.
+    This makes the installed pnglibconf.h more readable but causes no
+    other change.  The intention is that users of libpng will find it
+    easier to understand if an API they need is missing.
+  Include png_reset_zstream() in png.c only when PNG_READ_SUPPORTED is defined.
+  Removed dummy_inflate.c from contrib/pngminim/encoder
+  Removed contrib/pngminim/*/gather.sh; gathering is now done in the makefile.
+Version 1.5.0beta24 [May 7, 2010]
+  Use bitwise "&" instead of arithmetic mod in pngrutil.c calculation of the
+    offset of the png_ptr->rowbuf pointer into png_ptr->big_row_buf.
+  Added more blank lines for readability.
+Version 1.5.0beta25 [June 18, 2010]
+  In pngpread.c: png_push_have_row() add check for new_row > height
+  Removed the now-redundant check for out-of-bounds new_row from example.c
+Version 1.5.0beta26 [June 18, 2010]
+  In pngpread.c: png_push_process_row() add check for too many rows.
+Version 1.5.0beta27 [June 18, 2010]
+  Removed the check added in beta25 as it is now redundant.
+Version 1.5.0beta28 [June 20, 2010]
+  Rewrote png_process_IDAT_data to consistently treat extra data as warnings
+    and handle end conditions more cleanly.
+  Removed the new (beta26) check in png_push_process_row().
+Version 1.5.0beta29 [June 21, 2010]
+  Revised scripts/options.awk to work on Sunos (but still doesn't work)
+  Added comment to options.awk and contrib/pngminim/*/makefile to try nawk.
+Version 1.5.0beta30 [June 22, 2010]
+  Stop memory leak when reading a malformed sCAL chunk.
+Version 1.5.0beta31 [June 26, 2010]
+  Revised pngpread.c patch of beta28 to avoid an endless loop.
+  Removed some trailing blanks.
+Version 1.5.0beta32 [June 26, 2010]
+  Removed leftover scripts/options.patch and scripts/options.rej
+Version 1.5.0beta33 [July 6, 3010]
+  Made FIXED and FLOATING options consistent in the APIs they enable and
+    disable.  Corrected scripts/options.awk to handle both command line
+    options and options specified in the .dfa files.
+  Changed char *msg to PNG_CONST char *msg in pngrutil.c
+  Make png_set_sRGB_gAMA_and_cHRM set values using either the fixed or
+    floating point APIs, but not both.
+  Reversed patch to remove error handler when the jmp_buf is stored in the
+    main program structure, not the png_struct.
+    The error handler is needed because the default handler in libpng will
+    always use the jmp_buf in the library control structure; this is never
+    set.  The gregbook code is a useful example because, even though it
+    uses setjmp/longjmp, it shows how error handling can be implemented
+    using control mechanisms not directly supported by libpng.  The
+    technique will work correctly with mechanisms such as Microsoft
+    Structure Exceptions or C++ exceptions (compiler willing - note that gcc
+    does not by default support interworking of C and C++ error handling.)
+  Reverted changes to call png_longjmp in contrib/gregbook where it is not
+    appropriate.  If mainprog->jmpbuf is used by setjmp, then png_longjmp
+    cannot be used.
+  Changed "extern PNG_EXPORT" to "PNG_EXPORT" in png.h (Jan Nijtmans)
+  Changed "extern" to "PNG_EXTERN" in pngpriv.h (except for the 'extern "C" {')
+Version 1.5.0beta34 [July 12, 2010]
+  Put #ifndef PNG_EXTERN, #endif around the define PNG_EXTERN in pngpriv.h
+Version 1.5.0beta35 [July 24, 2010]
+  Removed some newly-added TAB characters.
+  Added -DNO_PNG_SNPRINTF to CFLAGS in scripts/makefile.dj2
+  Moved the definition of png_snprintf() outside of the enclosing
+    #ifdef blocks in pngconf.h
+Version 1.5.0beta36 [July 29, 2010]
+  Patches by John Bowler:
+  Fixed point APIs are now supported throughout (no missing APIs).
+  Internal fixed point arithmetic support exists for all internal floating
+    point operations.
+  sCAL validates the floating point strings it is passed.
+  Safe, albeit rudimentary, Watcom support is provided by PNG_API_RULE==2
+  Two new APIs exist to get the number of passes without turning on the
+    PNG_INTERLACE transform and to get the number of rows in the current
+    pass.
+  A new test program, pngvalid.c, validates the gamma code.
+  Errors in the 16-bit gamma correction (overflows) have been corrected.
+  cHRM chunk testing is done consistently (previously the floating point
+    API bypassed it, because the test really didn't work on FP, now the test
+    is performed on the actual values to be stored in the PNG file so it
+    works in the FP case too.)
+  Most floating point APIs now simply call the fixed point APIs after
+    converting the values to the fixed point form used in the PNG file.
+  The standard headers no longer include zlib.h, which is currently only
+    required for pngstruct.h and can therefore be internal.
+  Revised png_get_int_32 to undo the PNG two's complement representation of
+    negative numbers.
+Version 1.5.0beta37 [July 30, 2010]
+  Added a typecast in png_get_int_32() in png.h and pngrutil.h to avoid
+    a compiler warning.
+  Replaced oFFs 0,0 with oFFs -10,20 in pngtest.png
+Version 1.5.0beta38 [July 31, 2010]
+  Implemented remaining "_fixed" functions.
+  Corrected a number of recently introduced warnings mostly resulting from
+    safe but uncast assignments to shorter integers.  Also added a zlib
+    VStudio release library project because the latest zlib Official Windows
+    build does not include such a thing.
+  Revised png_get_int_16() to be similar to png_get_int_32().
+  Restored projects/visualc71.
+Version 1.5.0beta39 [August 2, 2010]
+  VisualC/GCC warning fixes, VisualC build fixes
+  The changes include support for function attributes in VC in addition to
+    those already present in GCC - necessary because without these some
+    warnings are unavoidable.  Fixes include signed/unsigned fixes in
+    pngvalid and checks with gcc -Wall -Wextra -Wunused.
+  VC requires function attributes on function definitions as well as
+    declarations, PNG_FUNCTION has been added to enable this and the
+    relevant function definitions changed.
+Version 1.5.0beta40 [August 6, 2010]
+  Correct use of _WINDOWS_ in pngconf.h
+  Removed png_mem_ #defines; they are no longer used.
+  Added the sRGB chunk to pngtest.png
+Version 1.5.0beta41 [August 11, 2010]
+  Added the cHRM chunk to pngtest.png
+  Don't try to use version-script with cygwin/mingw.
+  Revised contrib/gregbook to work under cygwin/mingw.
+Version 1.5.0beta42 [August 18, 2010]
+  Add .dll.a to the list of extensions to be symlinked by Makefile.am (Yaakov)
+  Made all API functions that have const arguments and constant string
+    literal pointers declare them (John Bowler).
+Version 1.5.0beta43 [August 20, 2010]
+  Removed spurious tabs, shorten long lines (no source change)
+    Also added scripts/chkfmt to validate the format of all the files that can
+    reasonably be validated (it is suggested to run "make distclean" before
+    checking, because some machine generated files have long lines.)
+  Reformatted the CHANGES file to be more consistent throughout.
+  Made changes to address various issues identified by GCC, mostly
+    signed/unsigned and shortening problems on assignment but also a few
+    difficult to optimize (for GCC) loops.
+  Fixed non-GCC fixed point builds.  In png.c a declaration was misplaced
+    in an earlier update.  Fixed to declare the auto variables at the head.
+  Use cexcept.h in pngvalid.c.
+Version 1.5.0beta44 [August 24, 2010]
+  Updated CMakeLists.txt to use CMAKE_INSTALL_LIBDIR variable; useful for
+    installing libpng in /usr/lib64 (Funda Wang).
+  Revised CMakeLists.txt to put the man pages in share/man/man* not man/man*
+  Revised CMakeLists.txt to make symlinks instead of copies when installing.
+  Changed PNG_LIB_NAME from pngNN to libpngNN in CMakeLists.txt (Philip Lowman)
+  Implemented memory checks within pngvalid
+  Reformatted/rearranged pngvalid.c to assist use of progressive reader.
+  Check interlaced images in pngvalid
+  Clarified pngusr.h comments in pnglibconf.dfa
+  Simplified the pngvalid error-handling code now that cexcept.h is in place.
+  Implemented progressive reader in pngvalid.c for standard tests
+  Implemented progressive read in pngvalid.c gamma tests
+  Turn on progressive reader in pngvalid.c by default and tidy code.
+Version 1.5.0beta45 [August 26, 2010]
+  Added an explicit make step to projects/vstudio for pnglibconf.h
+    Also corrected zlib.vcxproj into which Visual Studio had introduced
+    what it calls an "authoring error".  The change to make pnglibconf.h
+    simply copies the file; in the future it may actually generate the
+    file from scripts/pnglibconf.dfa as the other build systems do.
+  Changed pngvalid to work when floating point APIs are disabled
+  Renamed the prebuilt scripts/pnglibconf.h to scripts/pnglibconf.h.prebuilt
+  Supply default values for PNG_USER_PRIVATEBUILD and PNG_USER_DLLFNAME_POSTFIX
+    in pngpriv.h in case the user neglected to define them in their pngusr.h
+Version 1.5.0beta46 [August 28, 2010]
+  Added new private header files to libpng_sources in CMakeLists.txt
+  Added PNG_READ_16BIT, PNG_WRITE_16BIT, and PNG_16BIT options.
+  Added reference to scripts/pnglibconf.h.prebuilt in the visualc71 project.
+Version 1.5.0beta47 [September 11, 2010]
+  Fixed a number of problems with 64-bit compilation reported by Visual
+    Studio 2010 (John Bowler).
+Version 1.5.0beta48 [October 4, 2010]
+  Updated CMakeLists.txt (Philip Lowman).
+  Revised autogen.sh to recognize and use $AUTOCONF, $AUTOMAKE, $AUTOHEADER,
+    $AUTOPOINT, $ACLOCAL and $LIBTOOLIZE
+  Fixed problem with symbols creation in Makefile.am which was assuming that
+    all versions of ccp write to standard output by default (Martin Banky). The
+    bug was introduced in libpng-1.2.9beta5.
+  Removed unused mkinstalldirs.
+Version 1.5.0beta49 [October 8, 2010]
+  Undid Makefile.am revision of 1.5.0beta48.
+Version 1.5.0beta50 [October 14, 2010]
+  Revised Makefile.in to account for mkinstalldirs being removed.
+  Added some "(unsigned long)" typecasts in printf statements in pngvalid.c.
+  Suppressed a compiler warning in png_handle_sPLT().
+  Check for out-of-range text compression mode in png_set_text().
+Version 1.5.0beta51 [October 15, 2010]
+  Changed embedded dates to "(PENDING RELEASE) in beta releases (and future
+    rc releases) to minimize the difference between releases.
+Version 1.5.0beta52 [October 16, 2010]
+  Restored some of the embedded dates (in png.h, png.c, documentation, etc.)
+Version 1.5.0beta53 [October 18, 2010]
+  Updated INSTALL to mention using "make maintainer-clean" and to remove
+    obsolete statement about a custom ltmain.sh
+  Disabled "color-tests" by default in Makefile.am so it will work with
+    automake versions earlier than 1.11.1
+  Use document name "libpng-manual.txt" instead of "libpng-<version>.txt"
+    to simplify version differences.
+  Removed obsolete remarks about setjmp handling from INSTALL.
+  Revised and renamed the typedef in png.h and png.c that was designed
+    to catch library and header mismatch.
+Version 1.5.0beta54 [November 10, 2010]
+  Require 48 bytes, not 64 bytes, for big_row_buf in overflow checks.
+  Used a consistent structure for the pngget.c functions.
+Version 1.5.0beta55 [November 21, 2010]
+  Revised png_get_uint_32, png_get_int_32, png_get_uint_16 (Cosmin)
+  Moved reading of file signature into png_read_sig (Cosmin)
+  Fixed atomicity of chunk header serialization (Cosmin)
+  Added test for io_state in pngtest.c (Cosmin)
+  Added "#!/bin/sh" at the top of contrib/pngminim/*/gather.sh scripts.
+  Changes to remove gcc warnings (John Bowler)
+    Certain optional gcc warning flags resulted in warnings in libpng code.
+    With these changes only -Wconversion and -Wcast-qual cannot be turned on.
+    Changes are trivial rearrangements of code.  -Wconversion is not possible
+    for pngrutil.c (because of the widespread use of += et al on variables
+    smaller than (int) or (unsigned int)) and -Wcast-qual is not possible
+    with pngwio.c and pngwutil.c because the 'write' callback and zlib
+    compression both fail to declare their input buffers with 'const'.
+Version 1.5.0beta56 [December 7, 2010]
+  Added the private PNG_UNUSED() macro definition in pngpriv.h.
+  Added some commentary about PNG_EXPORT in png.h and pngconf.h
+  Revised PNG_EXPORT() macro and added PNG_EXPORTA() macro, with the
+    objective of simplifying and improving the cosmetic appearance of png.h.
+  Fixed some incorrect "=" macro names in pnglibconf.dfa
+  Included documentation of changes in 1.5.0 from 1.4.x in libpng-manual.txt
+Version 1.5.0beta57 [December 9, 2010]
+  Documented the pngvalid gamma error summary with additional comments and
+    print statements.
+  Improved missing symbol handling in checksym.awk; symbols missing in both
+    the old and new files can now be optionally ignored, treated as errors
+    or warnings.
+  Removed references to pngvcrd.c and pnggccrd.c from the vstudio project.
+  Updated "libpng14" to "libpng15" in the visualc71 project.
+  Enabled the strip16 tests in pngvalid.`
+  Don't display test results (except PASS/FAIL) when running "make test".
+    Instead put them in pngtest-log.txt
+  Added "--with-zprefix=<string>" to configure.ac
+  Updated the prebuilt configuration files to autoconf version 2.68
+Version 1.5.0beta58 [December 19, 2010]
+  Fixed interlace image handling and add test cases (John Bowler)
+  Fixed the clean rule in Makefile.am to remove pngtest-log.txt
+  Made minor changes to work around warnings in gcc 3.4
+Version 1.5.0rc01 [December 27, 2010]
+  No changes.
+Version 1.5.0rc02 [December 27, 2010]
+  Eliminated references to the scripts/*.def files in project/visualc71.
+Version 1.5.0rc03 [December 28, 2010]
+  Eliminated scripts/*.def and revised Makefile.am accordingly
+Version 1.5.0rc04 [December 29, 2010]
+  Fixed bug in background transformation handling in pngrtran.c (it was
+    looking for the flag in png_ptr->transformations instead of in
+    png_ptr->flags) (David Raymond).
+Version 1.5.0rc05 [December 31, 2010]
+  Fixed typo in a comment in CMakeLists.txt (libpng14 => libpng15) (Cosmin)
+Version 1.5.0rc06 [January 4, 2011]
+  Changed the new configure option "zprefix=string" to "zlib-prefix=string"
+Version 1.5.0rc07 [January 4, 2011]
+  Updated copyright year.
+Version 1.5.0 [January 6, 2011]
+  No changes.
+version 1.5.1beta01 [January 8, 2011]
+  Added description of png_set_crc_action() to the manual.
+  Added a note in the manual that the type of the iCCP profile was changed
+    from png_charpp to png_bytepp in png_get_iCCP().  This change happened
+    in version 1.5.0beta36 but is not noted in the CHANGES.  Similarly,
+    it was changed from png_charpp to png_const_bytepp in png_set_iCCP().
+  Ensure that png_rgb_to_gray ignores palette mapped images, if libpng
+    internally happens to call it with one, and fixed a failure to handle
+    palette mapped images correctly.  This fixes CVE-2690.
+Version 1.5.1beta02 [January 14, 2011]
+  Fixed a bug in handling of interlaced images (bero at arklinux.org).
+  Updated CMakeLists.txt (Clifford Yapp)
+Version 1.5.1beta03 [January 14, 2011]
+  Fixed typecasting of some png_debug() statements (Cosmin)
+Version 1.5.1beta04 [January 16, 2011]
+  Updated documentation of png_set|get_tRNS() (Thomas Klausner).
+  Mentioned in the documentation that applications must #include "zlib.h"
+    if they need access to anything in zlib.h, and that a number of
+    macros such as png_memset() are no longer accessible by applications.
+  Corrected pngvalid gamma test "sample" function to access all of the color
+    samples of each pixel, instead of sampling the red channel three times.
+  Prefixed variable names index, div, exp, gamma with "png_" to avoid "shadow"
+    warnings, and (mistakenly) changed png_exp() to exp().
+Version 1.5.1beta05 [January 16, 2011]
+  Changed variable names png_index, png_div, png_exp, and png_gamma to
+    char_index, divisor, exp_b10, and gamma_val, respectively, and
+    changed exp() back to png_exp().
+Version 1.5.1beta06 [January 20, 2011]
+  Prevent png_push_crc_skip() from hanging while reading an unknown chunk
+    or an over-large compressed zTXt chunk with the progressive reader.
+  Eliminated more GCC "shadow" warnings.
+  Revised png_fixed() in png.c to avoid compiler warning about reaching the
+    end without returning anything.
+Version 1.5.1beta07 [January 22, 2011]
+  In the manual, describe the png_get_IHDR() arguments in the correct order.
+  Added const_png_structp and const_png_infop types, and used them in
+    prototypes for most png_get_*() functions.
+Version 1.5.1beta08 [January 23, 2011]
+  Added png_get_io_chunk_type() and deprecated png_get_io_chunk_name()
+  Added synopses for the IO_STATE functions and other missing synopses
+    to the manual. Removed the synopses from libpngpf.3 because they
+    were out of date and no longer useful.  Better information can be
+    obtained by reading the prototypes and comments in pngpriv.h
+  Attempted to fix cpp on Solaris with S. Studio 12 cc, fix build
+    Added a make macro DFNCPP that is a CPP that will accept the tokens in
+    a .dfn file and adds configure stuff to test for such a CPP.  ./configure
+    should fail if one is not available.
+  Corrected const_png_ in png.h to png_const_ to avoid polluting the namespace.
+  Added png_get_current_row_number and png_get_current_pass_number for the
+    benefit of the user transform callback.
+  Added png_process_data_pause and png_process_data_skip for the benefit of
+    progressive readers that need to stop data processing or want to optimize
+    skipping of unread data (e.g., if the reader marks a chunk to be skipped.)
+Version 1.5.1beta09 [January 24, 2011]
+  Enhanced pngvalid, corrected an error in gray_to_rgb, corrected doc error.
+    pngvalid contains tests of transforms, which tests are currently disabled
+    because they are incompletely tested.  gray_to_rgb was failing to expand
+    the bit depth for smaller bit depth images; this seems to be a long
+    standing error and resulted, apparently, in invalid output
+    (CVE-2011-0408, CERT VU#643140).  The documentation did not accurately
+    describe what libpng really does when converting RGB to gray.
+Version 1.5.1beta10 [January 27, 2010]
+  Fixed incorrect examples of callback prototypes in the manual, that were
+    introduced in libpng-1.0.0.
+  In addition the order of the png_get_uint macros with respect to the
+    relevant function definitions has been reversed.  This helps the
+    preprocessing of the symbol files be more robust.  Furthermore, the
+    symbol file preprocessing now uses -DPNG_NO_USE_READ_MACROS even when
+    the library may actually be built with PNG_USE_READ_MACROS; this stops
+    the read macros interfering with the symbol file format.
+  Made the manual, synopses, and function prototypes use the function
+    argument names file_gamma, int_file_gamma, and srgb_intent consistently.
+Version 1.5.1beta11 [January 28, 2011]
+  Changed PNG_UNUSED from "param=param;" to "{if(param){}}".
+  Corrected local variable type in new API png_process_data_skip()
+    The type was self-evidently incorrect but only causes problems on 64-bit
+    architectures.
+  Added transform tests to pngvalid and simplified the arguments.
+Version 1.5.1rc01 [January 29, 2011]
+  No changes.
+Version 1.5.1rc02 [January 31, 2011]
+  Added a request in the manual that applications do not use "png_" or
+    "PNG_" to begin any of their own symbols.
+  Changed PNG_UNUSED to "(void)param;" and updated the commentary in pngpriv.h
+Version 1.5.1 [February 3, 2011]
+  No changes.
+Version 1.5.2beta01 [February 13, 2011]
+  More -Wshadow fixes for older gcc compilers.  Older gcc versions apparently
+    check formal parameters names in function declarations (as well as
+    definitions) to see if they match a name in the global namespace.
+  Revised PNG_EXPORTA macro to not use an empty parameter, to accommodate the
+    old VisualC++ preprocessor.
+  Turned on interlace handling in png_read_png().
+  Fixed gcc pendantic warnings.
+  Handle longjmp in Cygwin.
+  Fixed png_get_current_row_number() in the interlaced case.
+  Cleaned up ALPHA flags and transformations.
+  Implemented expansion to 16 bits.
+Version 1.5.2beta02 [February 19, 2011]
+  Fixed mistake in the descriptions of user read_transform and write_transform
+    function prototypes in the manual.  The row_info struct is png_row_infop.
+  Reverted png_get_current_row_number() to previous (1.5.2beta01) behavior.
+  Corrected png_get_current_row_number documentation
+  Fixed the read/write row callback documentation.
+    This documents the current behavior, where the callback is called after
+    every row with information pertaining to the next row.
+Version 1.5.2beta03 [March 3, 2011]
+  Fixed scripts/makefile.vcwin32
+  Updated contrib/pngsuite/README to add the word "modify".
+  Define PNG_ALLOCATED to blank when _MSC_VER<1300.
+Version 1.5.2rc01 [March 19, 2011]
+  Define remaining attributes to blank when MSC_VER<1300.
+  ifdef out mask arrays in pngread.c when interlacing is not supported.
+Version 1.5.2rc02 [March 22, 2011]
+  Added a hint to try CPP=/bin/cpp if "cpp -E" fails in scripts/pnglibconf.mak
+    and in contrib/pngminim/*/makefile, eg., on SunOS 5.10, and removed "strip"
+    from the makefiles.
+  Fixed a bug (present since libpng-1.0.7) that makes png_handle_sPLT() fail
+    to compile when PNG_NO_POINTER_INDEXING is defined (Chubanov Kirill)
+Version 1.5.2rc03 [March 24, 2011]
+  Don't include standard header files in png.h while building the symbol table,
+    to avoid cpp failure on SunOS (introduced PNG_BUILDING_SYMBOL_TABLE macro).
+Version 1.5.2 [March 31, 2011]
+  No changes.
+Version 1.5.3beta01 [April 1, 2011]
+  Re-initialize the zlib compressor before compressing non-IDAT chunks.
+  Added API functions (png_set_text_compression_level() and four others) to
+    set parameters for zlib compression of non-IDAT chunks.
+Version 1.5.3beta02 [April 3, 2011]
+  Updated scripts/symbols.def with new API functions.
+  Only compile the new zlib re-initializing code when text or iCCP is
+    supported, using PNG_WRITE_COMPRESSED_TEXT_SUPPORTED macro.
+  Improved the optimization of the zlib CMF byte (see libpng-1.2.6beta03).
+  Optimize the zlib CMF byte in non-IDAT compressed chunks
+Version 1.5.3beta03 [April 16, 2011]
+  Fixed gcc -ansi -pedantic compile. A strict ANSI system does not have
+    snprintf, and the "__STRICT_ANSI__" detects that condition more reliably
+    than __STDC__ (John Bowler).
+  Removed the PNG_PTR_NORETURN attribute because it too dangerous. It tells
+    the compiler that a user supplied callback (the error handler) does not
+    return, yet there is no guarantee in practice that the application code
+    will correctly implement the error handler because the compiler only
+    issues a warning if there is a mistake (John Bowler).
+  Removed the no-longer-used PNG_DEPSTRUCT macro.
+  Updated the zlib version to 1.2.5 in the VStudio project.
+  Fixed 64-bit builds where png_uint_32 is smaller than png_size_t in
+    pngwutil.c (John Bowler).
+  Fixed bug with stripping the filler or alpha channel when writing, that
+    was introduced in libpng-1.5.2beta01 (bug report by Andrew Church).
+Version 1.5.3beta04 [April 27, 2011]
+  Updated pngtest.png with the new zlib CMF optimization.
+  Cleaned up conditional compilation code and of background/gamma handling
+    Internal changes only except a new option to avoid compiling the
+    png_build_grayscale_palette API (which is not used at all internally.)
+    The main change is to move the transform tests (READ_TRANSFORMS,
+    WRITE_TRANSFORMS) up one level to the caller of the APIs.  This avoids
+    calls to spurious functions if all transforms are disabled and slightly
+    simplifies those functions.  Pngvalid modified to handle this.
+    A minor change is to stop the strip_16 and expand_16 interfaces from
+    disabling each other; this allows the future alpha premultiplication
+    code to use 16-bit intermediate values while still producing 8-bit output.
+    png_do_background and png_do_gamma have been simplified to take a single
+    pointer to the png_struct rather than pointers to every item required
+    from the png_struct. This makes no practical difference to the internal
+    code.
+  A serious bug in the pngvalid internal routine 'standard_display_init' has
+    been fixed - this failed to initialize the red channel and accidentally
+    initialized the alpha channel twice.
+  Changed png_struct jmp_buf member name from png_jmpbuf to tmp_jmpbuf to
+    avoid a possible clash with the png_jmpbuf macro on some platforms.
+Version 1.5.3beta05 [May 6, 2011]
+  Added the "_POSIX_SOURCE" feature test macro to ensure libpng sees the
+    correct API. _POSIX_SOURCE is defined in pngpriv.h, pngtest.c and
+    pngvalid.c to ensure that POSIX conformant systems disable non-POSIX APIs.
+  Removed png_snprintf and added formatted warning messages.  This change adds
+    internal APIs to allow png_warning messages to have parameters without
+    requiring the host OS to implement snprintf.  As a side effect the
+    dependency of the tIME-supporting RFC1132 code on stdio is removed and
+    PNG_NO_WARNINGS does actually work now.
+  Pass "" instead of '\0' to png_default_error() in png_err().  This mistake
+    was introduced in libpng-1.2.20beta01.  This fixes CVE-2011-2691.
+  Added PNG_WRITE_OPTIMIZE_CMF_SUPPORTED macro to make the zlib "CMF" byte
+    optimization configureable.
+  IDAT compression failed if preceded by a compressed text chunk (bug
+    introduced in libpng-1.5.3beta01-02).  This was because the attempt to
+    reset the zlib stream in png_write_IDAT happened after the first IDAT
+    chunk had been deflated - much too late.  In this change internal
+    functions were added to claim/release the z_stream and, hopefully, make
+    the code more robust.  Also deflateEnd checking is added - previously
+    libpng would ignore an error at the end of the stream.
+Version 1.5.3beta06 [May 8, 2011]
+  Removed the -D_ALL_SOURCE from definitions for AIX in CMakeLists.txt
+  Implemented premultiplied alpha support: png_set_alpha_mode API
+Version 1.5.3beta07 [May 11, 2011]
+  Added expand_16 support to the high level interface.
+  Added named value and 'flag' gamma support to png_set_gamma.  Made a minor
+    change from the previous (unreleased) ABI/API to hide the exact value used
+    for Macs - it's not a good idea to embed this in the ABI!
+  Moved macro definitions for PNG_HAVE_IHDR, PNG_HAVE_PLTE, and PNG_AFTER_IDAT
+    from pngpriv.h to png.h because they must be visible to applications
+    that call png_set_unknown_chunks().
+  Check for up->location !PNG_AFTER_IDAT when writing unknown chunks
+    before IDAT.
+Version 1.5.3beta08 [May 16, 2011]
+  Improved "pngvalid --speed" to exclude more of pngvalid from the time.
+  Documented png_set_alpha_mode(), other changes in libpng.3/libpng-manual.txt
+  The cHRM chunk now sets the defaults for png_set_rgb_to_gray() (when negative
+    parameters are supplied by the caller), while in the absence of cHRM
+    sRGB/Rec 709 values are still used.  This introduced a divide-by-zero
+    bug in png_handle_cHRM().
+  The bKGD chunk no longer overwrites the background value set by
+    png_set_background(), allowing the latter to be used before the file
+    header is read. It never performed any useful function to override
+    the default anyway.
+  Added memory overwrite and palette image checks to pngvalid.c
+    Previously palette image code was poorly checked. Since the transformation
+    code has a special palette path in most cases this was a severe weakness.
+  Minor cleanup and some extra checking in pngrutil.c and pngrtran.c. When
+    expanding an indexed image, always expand to RGBA if transparency is
+    present.
+Version 1.5.3beta09 [May 17, 2011]
+  Reversed earlier 1.5.3 change of transformation order; move png_expand_16
+    back where it was.  The change doesn't work because it requires 16-bit
+    gamma tables when the code only generates 8-bit ones.  This fails
+    silently; the libpng code just doesn't do any gamma correction.  Moving
+    the tests back leaves the old, inaccurate, 8-bit gamma calculations, but
+    these are clearly better than none!
+Version 1.5.3beta10 [May 20, 2011]
+  png_set_background() and png_expand_16() did not work together correctly.
+    This problem is present in 1.5.2; if png_set_background is called with
+    need_expand false and the matching 16 bit color libpng erroneously just
+    treats it as an 8-bit color because of where png_do_expand_16 is in the
+    transform list.  This simple fix reduces the supplied colour to 8-bits,
+    so it gets smashed, but this is better than the current behavior.
+  Added tests for expand16, more fixes for palette image tests to pngvalid.
+    Corrects the code for palette image tests and disables attempts to
+    validate palette colors.
+Version 1.5.3rc01 [June 3, 2011]
+  No changes.
+Version 1.5.3rc02 [June 8, 2011]
+  Fixed uninitialized memory read in png_format_buffer() (Bug report by
+    Frank Busse, CVE-2011-2501, related to CVE-2004-0421).
+Version 1.5.3beta11 [June 11, 2011]
+  Fixed png_handle_sCAL which is broken in 1.5. This fixes CVE 2011-2692.
+  Added sCAL to pngtest.png
+  Revised documentation about png_set_user_limits() to say that it also affects
+    png writing.
+  Revised handling of png_set_user_limits() so that it can increase the
+    limit beyond the PNG_USER_WIDTH|HEIGHT_MAX; previously it could only
+    reduce it.
+  Make the 16-to-8 scaling accurate. Dividing by 256 with no rounding is
+    wrong (high by one) 25% of the time. Dividing by 257 with rounding is
+    wrong in 128 out of 65536 cases. Getting the right answer all the time
+    without division is easy.
+  Added "_SUPPORTED" to the PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION macro.
+  Added projects/owatcom, an IDE project for OpenWatcom to replace
+    scripts/makefile.watcom.  This project works with OpenWatcom 1.9. The
+    IDE autogenerates appropriate makefiles (libpng.mk) for batch processing.
+    The project is configurable, unlike the Visual Studio project, so long
+    as the developer has an awk.
+  Changed png_set_gAMA to limit the gamma value range so that the inverse
+    of the stored value cannot overflow the fixed point representation,
+    and changed other things OpenWatcom warns about.
+  Revised pngvalid.c to test PNG_ALPHA_MODE_SUPPORTED correctly. This allows
+    pngvalid to build when ALPHA_MODE is not supported, which is required if
+    it is to build on libpng 1.4.
+  Removed string/memory macros that are no longer used and are not
+    necessarily fully supportable, particularly png_strncpy and png_snprintf.
+  Added log option to pngvalid.c and attempted to improve gamma messages.
+Version 1.5.3 [omitted]
+  People found the presence of a beta release following an rc release
+    to be confusing; therefore we bump the version to libpng-1.5.4beta01
+    and there will be no libpng-1.5.3 release.
+Version 1.5.4beta01 [June 14, 2011]
+  Made it possible to undefine PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED
+    to get the same (inaccurate) output as libpng-1.5.2 and earlier.
+  Moved definitions of PNG_HAVE_IHDR, PNG_AFTER_IDAT, and PNG_HAVE_PLTE
+    outside of an unknown-chunk block in png.h because they are also
+    needed for other uses.
+Version 1.5.4beta02 [June 14, 2011]
+  Fixed and clarified LEGACY 16-to-8 scaling code.
+  Added png_set_chop_16() API, to match inaccurate results from previous
+    libpng versions.
+  Removed the ACCURATE and LEGACY options (they are no longer useable)
+  Use the old scaling method for background if png_set_chop_16() was
+    called.
+  Made png_set_chop_16() API removeable by disabling PNG_CHOP_16_TO_8_SUPPORTED
+Version 1.5.4beta03 [June 15, 2011]
+  Fixed a problem in png_do_expand_palette() exposed by optimization in
+    1.5.3beta06
+  Also removed a spurious and confusing "trans" member ("trans") from png_info.
+  The palette expand optimization prevented expansion to an intermediate RGBA
+    form if tRNS was present but alpha was marked to be stripped; this exposed
+    a check for tRNS in png_do_expand_palette() which is inconsistent with the
+    code elsewhere in libpng.
+  Correction to the expand_16 code; removed extra instance of
+    png_set_scale_16_to_8 from pngpriv.h
+Version 1.5.4beta04 [June 16, 2011]
+  Added a missing "#ifdef PNG_READ_BACKGROUND_SUPPORTED/#endif" in pngrtran.c
+  Added PNG_TRANSFORM_CHOP_16 to the high-level read transforms.
+  Made PNG_READ_16_TO_8_ACCURATE_SCALE configurable again.  If this is
+    not enabled, png_set_strip_16() and png_do_scale_16_to_8() aren't built.
+  Revised contrib/visupng, gregbook, and pngminim to demonstrate chop_16_to_8
+Version 1.5.4beta05 [June 16, 2011]
+  Renamed png_set_strip_16() to png_set_scale_16() and renamed
+    png_set_chop_16() to png_set_strip(16) in an attempt to minimize the
+    behavior changes between libpng14 and libpng15.
+Version 1.5.4beta06 [June 18, 2011]
+  Fixed new bug that was causing both strip_16 and scale_16 to be applied.
+Version 1.5.4beta07 [June 19, 2011]
+  Fixed pngvalid, simplified macros, added checking for 0 in sCAL.
+    The ACCURATE scale macro is no longer defined in 1.5 - call the
+    png_scale_16_to_8 API.  Made sure that PNG_READ_16_TO_8 is still defined
+    if the png_strip_16_to_8 API is present.  png_check_fp_number now
+    maintains some state so that positive, negative and zero values are
+    identified.  sCAL uses these to be strictly spec conformant.
+Version 1.5.4beta08 [June 23, 2011]
+  Fixed pngvalid if ACCURATE_SCALE is defined.
+  Updated scripts/pnglibconf.h.prebuilt.
+Version 1.5.4rc01 [June 30, 2011]
+  Define PNG_ALLOCATED to "restrict" only if MSC_VER >= 1400.
+Version 1.5.4 [July 7, 2011]
+  No changes.
+Version 1.5.5beta01 [July 13, 2011]
+  Fixed some typos and made other minor changes in the manual.
+  Updated contrib/pngminus/makefile.std (Samuli Souminen)
+Version 1.5.5beta02 [July 14, 2011]
+  Revised Makefile.am and Makefile.in to look in the right directory for
+    pnglibconf.h.prebuilt
+Version 1.5.5beta03 [July 27, 2011]
+  Enabled compilation with g++ compiler.  This compiler does not recognize
+    the file extension, so it always compiles with C++ rules.  Made minor
+    changes to pngrutil.c to cast results where C++ expects it but C does not.
+  Minor editing of libpng.3 and libpng-manual.txt.
+Version 1.5.5beta04 [July 29, 2011]
+  Revised CMakeLists.txt (Clifford Yapp)
+  Updated commentary about the png_rgb_to_gray() default coefficients
+    in the manual and in pngrtran.c
+Version 1.5.5beta05 [August 17, 2011]
+  Prevent unexpected API exports from non-libpng DLLs on Windows.  The "_DLL"
+    is removed from the test of whether a DLL is being built (this erroneously
+    caused the libpng APIs to be marked as DLL exports in static builds under
+    Microsoft Visual Studio).  Almost all of the libpng building configuration
+    is moved from pngconf.h to pngpriv.h, but PNG_DLL_EXPORT remains in
+    pngconf.h, though, so that it is colocated with the import definition (it
+    is no longer used anywhere in the installed headers).  The VStudio project
+    definitions have been cleaned up: "_USRDLL" has been removed from the
+    static library builds (this was incorrect), and PNG_USE_DLL has been added
+    to pngvalid to test the functionality (pngtest does not supply it,
+    deliberately).  The spurious "_EXPORTS" has been removed from the
+    libpng build (all these errors were a result of copy/paste between project
+    configurations.)
+  Added new types and internal functions for CIE RGB end point handling to
+    pngpriv.h (functions yet to be implemented).
+Version 1.5.5beta06 [August 26, 2011]
+  Ensure the CMAKE_LIBRARY_OUTPUT_DIRECTORY is set in CMakeLists.txt
+    (Clifford Yap)
+  Fixes to rgb_to_gray and cHRM XYZ APIs (John Bowler):
+    The rgb_to_gray code had errors when combined with gamma correction.
+    Some pixels were treated as true grey when they weren't and such pixels
+    and true grey ones were not gamma corrected (the original value of the
+    red component was used instead).  APIs to get and set cHRM using color
+    space end points have been added and the rgb_to_gray code that defaults
+    based on cHRM, and the divide-by-zero bug in png_handle_cHRM (CERT
+    VU#477046, CVE-2011-3328, introduced in 1.5.4) have been corrected.
+  A considerable number of tests has been added to pngvalid for the
+    rgb_to_gray transform.
+  Arithmetic errors in rgb_to_gray whereby the calculated gray value was
+    truncated to the bit depth rather than rounded have been fixed except in
+    the 8-bit non-gamma-corrected case (where consistency seems more important
+    than correctness.)  The code still has considerable inaccuracies in the
+    8-bit case because 8-bit linear arithmetic is used.
+Version 1.5.5beta07 [September 7, 2011]
+  Added "$(ARCH)" option to makefile.darwin
+  Added SunOS support to configure.ac and Makefile.am
+  Changed png_chunk_benign_error() to png_warning() in png.c, in
+    png_XYZ_from_xy_checked().
+Version 1.5.5beta08 [September 10, 2011]
+  Fixed 64-bit compilation errors (gcc). The errors fixed relate
+    to conditions where types that are 32 bits in the GCC 32-bit
+    world (uLong and png_size_t) become 64 bits in the 64-bit
+    world.  This produces potential truncation errors which the
+    compiler correctly flags.
+  Relocated new HAVE_SOLARIS_LD definition in configure.ac
+  Constant changes for 64-bit compatibility (removal of L suffixes). The
+    16-bit cases still use "L" as we don't have a 16-bit test system.
+Version 1.5.5rc01 [September 15, 2011]
+  Removed "L" suffixes in pngpriv.h
+Version 1.5.5 [September 22, 2011]
+  No changes.
+Version 1.5.6beta01 [September 22, 2011]
+  Fixed some 64-bit type conversion warnings in pngrtran.c
+  Moved row_info from png_struct to a local variable.
+  The various interlace mask arrays have been made into arrays of
+    bytes and made PNG_CONST and static (previously some arrays were
+    marked PNG_CONST and some weren't).
+  Additional checks have been added to the transform code to validate the
+    pixel depths after the transforms on both read and write.
+  Removed some redundant code from pngwrite.c, in png_destroy_write_struct().
+  Changed chunk reading/writing code to use png_uint_32 instead of png_byte[4].
+    This removes the need to allocate temporary strings for chunk names on
+    the stack in the read/write code.  Unknown chunk handling still uses the
+    string form because this is exposed in the API.
+Version 1.5.6beta02 [September 26, 2011]
+  Added a note in the manual the png_read_update_info() must be called only
+    once with a particular info_ptr.
+  Fixed a typo in the definition of the new PNG_STRING_FROM_CHUNK(s,c) macro.
+Version 1.5.6beta03 [September 28, 2011]
+  Revised test-pngtest.sh to report FAIL when pngtest fails.
+  Added "--strict" option to pngtest, to report FAIL when the failure is
+    only because the resulting valid files are different.
+  Revised CMakeLists.txt to work with mingw and removed some material from
+    CMakeLists.txt that is no longer useful in libpng-1.5.
+Version 1.5.6beta04 [October 5, 2011]
+  Fixed typo in Makefile.in and Makefile.am ("-M Wl" should be "-M -Wl")."
+Version 1.5.6beta05 [October 12, 2011]
+  Speed up png_combine_row() for interlaced images. This reduces the generality
+    of the code, allowing it to be optimized for Adam7 interlace.  The masks
+    passed to png_combine_row() are now generated internally, avoiding
+    some code duplication and localizing the interlace handling somewhat.
+  Align png_struct::row_buf - previously it was always unaligned, caused by
+    a bug in the code that attempted to align it; the code needs to subtract
+    one from the pointer to take account of the filter byte prepended to
+    each row.
+  Optimized png_combine_row() when rows are aligned. This gains a small
+    percentage for 16-bit and 32-bit pixels in the typical case where the
+    output row buffers are appropriately aligned. The optimization was not
+    previously possible because the png_struct buffer was always misaligned.
+  Fixed bug in png_write_chunk_header() debug print, introduced in 1.5.6beta01.
+Version 1.5.6beta06 [October 17, 2011]
+  Removed two redundant tests for unitialized row.
+  Fixed a relatively harmless memory overwrite in compressed text writing
+    with a 1 byte zlib buffer.
+  Add ability to call png_read_update_info multiple times to pngvalid.c.
+  Fixes for multiple calls to png_read_update_info. These fixes attend to
+    most of the errors revealed in pngvalid, however doing the gamma work
+    twice results in inaccuracies that can't be easily fixed.  There is now
+    a warning in the code if this is going to happen.
+  Turned on multiple png_read_update_info in pngvalid transform tests.
+  Prevent libpng from overwriting unused bits at the end of the image when
+    it is not byte aligned, while reading. Prior to libpng-1.5.6 libpng would
+    overwrite the partial byte at the end of each row if the row width was not
+    an exact multiple of 8 bits and the image is not interlaced.
+Version 1.5.6beta07 [October 21, 2011]
+  Made png_ptr->prev_row an aligned pointer into png_ptr->big_prev_row
+    (Mans Rullgard).
+Version 1.5.6rc01 [October 26, 2011]
+  Changed misleading "Missing PLTE before cHRM" warning to "Out of place cHRM"
+Version 1.5.6rc02 [October 27, 2011]
+  Added LSR() macro to defend against buggy compilers that evaluate non-taken
+    code branches and complain about out-of-range shifts.
+Version 1.5.6rc03 [October 28, 2011]
+  Renamed the LSR() macro to PNG_LSR() and added PNG_LSL() macro.
+  Fixed compiler warnings with Intel and MSYS compilers. The logical shift
+    fix for Microsoft Visual C is required by other compilers, so this
+    enables that fix for all compilers when using compile-time constants.
+    Under MSYS 'byte' is a name declared in a system header file, so we
+    changed the name of a local variable to avoid the warnings that result.
+  Added #define PNG_ALIGN_TYPE PNG_ALIGN_NONE to contrib/pngminim/*/pngusr.h
+Version 1.5.6 [November 3, 2011]
+  No changes.
+Version 1.5.7beta01 [November 4, 2011]
+  Added support for ARM processor (Mans Rullgard)
+  Fixed bug in pngvalid on early allocation failure; fixed type cast in
+    pngmem.c; pngvalid would attempt to call png_error() if the allocation
+    of a png_struct or png_info failed. This would probably have led to a
+    crash.  The pngmem.c implementation of png_malloc() included a cast
+    to png_size_t which would fail on large allocations on 16-bit systems.
+  Fix for the preprocessor of the Intel C compiler. The preprocessor
+    splits adjacent @ signs with a space; this changes the concatentation
+    token from @-@-@ to PNG_JOIN; that should work with all compiler
+    preprocessors.
+  Paeth filter speed improvements from work by Siarhei Siamashka. This
+    changes the 'Paeth' reconstruction function to improve the GCC code
+    generation on x86. The changes are only part of the suggested ones;
+    just the changes that definitely improve speed and remain simple.
+    The changes also slightly increase the clarity of the code.
+Version 1.5.7beta02 [November 11, 2011]
+  Check compression_type parameter in png_get_iCCP and remove spurious
+    casts. The compression_type parameter is always assigned to, so must
+    be non-NULL. The cast of the profile length potentially truncated the
+    value unnecessarily on a 16-bit int system, so the cast of the (byte)
+    compression type to (int) is specified by ANSI-C anyway.
+  Fixed FP division by zero in pngvalid.c; the 'test_pixel' code left
+    the sBIT fields in the test pixel as 0, which resulted in a floating
+    point division by zero which was irrelevant but causes systems where
+    FP exceptions cause a crash. Added code to pngvalid to turn on FP
+    exceptions if the appropriate glibc support is there to ensure this is
+    tested in the future.
+  Updated scripts/pnglibconf.mak and scripts/makefile.std to handle the
+    new PNG_JOIN macro.
+  Added versioning to pnglibconf.h comments.
+  Simplified read/write API initial version; basic read/write tested on
+    a variety of images, limited documentation (in the header file.)
+  Installed more accurate linear to sRGB conversion tables. The slightly
+    modified tables reduce the number of 16-bit values that
+    convert to an off-by-one 8-bit value.  The "makesRGB.c" code that was used
+    to generate the tables is now in a contrib/sRGBtables sub-directory.
+Version 1.5.7beta03 [November 17, 2011]
+  Removed PNG_CONST from the sRGB table declarations in pngpriv.h and png.c
+  Added run-time detection of NEON support.
+  Added contrib/libtests; includes simplified API test and timing test and
+    a color conversion utility for rapid checking of failed 'pngstest' results.
+  Multiple transform bug fixes plus a work-round for double gamma correction.
+    libpng does not support more than one transform that requires linear data
+    at once - if this is tried typically the results is double gamma
+    correction. Since the simplified APIs can need rgb to gray combined with
+    a compose operation it is necessary to do one of these outside the main
+    libpng transform code. This check-in also contains fixes to various bugs
+    in the simplified APIs themselves and to some bugs in compose and rgb to
+    gray (on palette) itself.
+  Fixes for C++ compilation using g++ When libpng source is compiled
+    using g++. The compiler imposes C++ rules on the C source; thus it
+    is desireable to make the source work with either C or C++ rules
+    without throwing away useful error information.  This change adds
+    png_voidcast to allow C semantic (void*) cases or the corresponding
+    C++ static_cast operation, as appropriate.
+  Added --noexecstack to assembler file compilation. GCC does not set
+    this on assembler compilation, even though it does on C compilation.
+    This creates security issues if assembler code is enabled; the
+    work-around is to set it by default in the flags for $(CCAS)
+  Work around compilers that don't support declaration of const data. Some
+    compilers fault 'extern const' data declarations (because the data is
+    not initialized); this turns on const-ness only for compilers where
+    this is known to work.
+Version 1.5.7beta04 [November 17, 2011]
+  Since the gcc driver does not recognize the --noexecstack flag, we must
+    use the -Wa prefix to have it passed through to the assembler.
+    Also removed a duplicate setting of this flag.
+  Added files that were omitted from the libpng-1.5.7beta03 zip distribution.
+Version 1.5.7beta05 [November 25, 2011]
+  Removed "zTXt" from warning in generic chunk decompression function.
+  Validate time settings passed to pngset() and png_convert_to_rfc1123()
+    (Frank Busse).
+  Added MINGW support to CMakeLists.txt
+  Reject invalid compression flag or method when reading the iTXt chunk.
+  Backed out 'simplified' API changes. The API seems too complex and there
+    is a lack of consensus or enthusiasm for the proposals.  The API also
+    reveals significant bugs inside libpng (double gamma correction and the
+    known bug of being unable to retrieve a corrected palette). It seems
+    better to wait until the bugs, at least, are corrected.
+  Moved pngvalid.c into contrib/libtests
+  Rebuilt Makefile.in, configure, etc., with autoconf-2.68
+Version 1.5.7rc01 [December 1, 2011]
+  Replaced an "#if" with "#ifdef" in pngrtran.c
+  Revised #if PNG_DO_BC block in png.c (use #ifdef and add #else)
+Version 1.5.7rc02 [December 5, 2011]
+  Revised project files and contrib/pngvalid/pngvalid.c to account for
+    the relocation of pngvalid into contrib/libtests.
+  Revised pngconf.h to use " __declspec(restrict)" only when MSC_VER >= 1400,
+    as in libpng-1.5.4.
+  Put CRLF line endings in the owatcom project files.
+Version 1.5.7rc03 [December 7, 2011]
+  Updated CMakeLists.txt to account for the relocation of pngvalid.c
+Version 1.5.7 [December 15, 2011]
+  Minor fixes to pngvalid.c for gcc 4.6.2 compatibility to remove warnings
+    reported by earlier versions.
+Version 1.5.8beta01 [January 15, 2011]
+  Removed '#include config.h"' from contrib/libtests/pngvalid.c.  It's not
+    needed and causes trouble for VPATH building.
+  Moved AC_MSG_CHECKING([if libraries can be versioned]) later to the proper
+    location in configure.ac (Gilles Espinasse).
+  Fix bug in pngerror.c: some long warnings were being improperly truncated
+    (CVE-2011-3464, bug introduced in libpng-1.5.3beta05).
+Version 1.5.8rc01 [January 21, 2012]
+  No changes.
+Version 1.5.8rc02 [January 25, 2012]
+  Fixed Min/GW uninstall to remove libpng.dll.a
+  Conditionalize the install rules for MINGW and CYGWIN in CMakeLists.txt
+Version 1.5.8 [February 1, 2012]
+  No changes.
+Version 1.5.9beta01 [February 3, 2012]
+  Rebuilt configure scripts in the tar distributions.
+Version 1.5.9beta02 [February 16, 2012]
+  Removed two unused definitions from scripts/pnglibconf.h.prebuilt
+  Removed some unused arrays (with #ifdef) from png_read_push_finish_row().
+  Removed tests for no-longer-used *_EMPTY_PLTE_SUPPORTED from pngstruct.h
+Version 1.5.9rc01 [February 17, 2012]
+  Fixed CVE-2011-3026 buffer overrun bug.  Deal more correctly with the test
+    on iCCP chunk length. Also removed spurious casts that may hide problems
+    on 16-bit systems.
+Version 1.5.9 [February 18, 2012]
+  No changes.
+Send comments/corrections/commendations to png-mng-implement at lists.sf.net
+(subscription required; visit
+https://lists.sourceforge.net/lists/listinfo/png-mng-implement
+to subscribe)
+or to glennrp at users.sourceforge.net
+Glenn R-P
+#endif
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/CMakeLists.txt b/libraries/irrlicht-1.8/source/Irrlicht/libpng/CMakeLists.txt
new file mode 100644
index 0000000..e9a421a
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/CMakeLists.txt
@@ -0,0 +1,348 @@
+# CMakeLists.txt
+# Copyright (C) 2007-2011 Glenn Randers-Pehrson
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+cmake_minimum_required(VERSION 2.4.4)
+set(CMAKE_ALLOW_LOOSE_LOOP_CONSTRUCTS true)
+if(UNIX AND NOT DEFINED CMAKE_BUILD_TYPE)
+  if(CMAKE_MAJOR_VERSION EQUAL 2 AND CMAKE_MINOR_VERSION EQUAL 4)
+    # workaround CMake 2.4.x bug
+    set(CMAKE_BUILD_TYPE "RelWithDebInfo" CACHE STRING
+        "Choose the type of build, options are:
+           None(CMAKE_CXX_FLAGS or CMAKE_C_FLAGS used)
+           Debug
+           Release
+           RelWithDebInfo
+           MinSizeRel.")
+  else()
+    set(CMAKE_BUILD_TYPE "RelWithDebInfo" CACHE STRING
+        "Choose the type of build, options are:
+           None(CMAKE_CXX_FLAGS or CMAKE_C_FLAGS used)
+           Debug
+           Release
+           RelWithDebInfo
+           MinSizeRel.")
+  endif()
+endif()
+project(libpng C)
+enable_testing()
+set(PNGLIB_MAJOR 1)
+set(PNGLIB_MINOR 5)
+set(PNGLIB_RELEASE 9)
+set(PNGLIB_NAME libpng${PNGLIB_MAJOR}${PNGLIB_MINOR})
+set(PNGLIB_VERSION ${PNGLIB_MAJOR}.${PNGLIB_MINOR}.${PNGLIB_RELEASE})
+# needed packages
+find_package(ZLIB REQUIRED)
+include_directories(${ZLIB_INCLUDE_DIR})
+if(NOT WIN32)
+  find_library(M_LIBRARY
+    NAMES m
+    PATHS /usr/lib /usr/local/lib
+  )
+  if(NOT M_LIBRARY)
+    message(STATUS
+      "math library 'libm' not found - floating point support disabled")
+  endif()
+else()
+  # not needed on windows
+  set(M_LIBRARY "")
+endif()
+# COMMAND LINE OPTIONS
+if(DEFINED PNG_SHARED)
+  option(PNG_SHARED "Build shared lib" ${PNG_SHARED})
+else()
+  option(PNG_SHARED "Build shared lib" ON)
+endif()
+if(DEFINED PNG_STATIC)
+  option(PNG_STATIC "Build static lib" ${PNG_STATIC})
+else()
+  option(PNG_STATIC "Build static lib" ON)
+endif()
+option(PNG_TESTS  "Build libpng tests" YES)
+# Many more configuration options could be added here
+option(PNG_DEBUG         "Build with debug output" NO)
+option(PNGARG            "Disable ANSI-C prototypes" NO)
+# SET LIBNAME
+set(PNG_LIB_NAME png${PNGLIB_MAJOR}${PNGLIB_MINOR})
+# to distinguish between debug and release lib
+set(CMAKE_DEBUG_POSTFIX "d")
+# Use the prebuilt pnglibconf.h file from the scripts folder
+# TODO: fix this by building with awk; without this no cmake build can be
+# configured directly (to do so indirectly use your local awk to build a
+# pnglibconf.h in the build directory.)
+configure_file(${CMAKE_CURRENT_SOURCE_DIR}/scripts/pnglibconf.h.prebuilt
+               ${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.h)
+include_directories(${CMAKE_CURRENT_BINARY_DIR})
+# OUR SOURCES
+set(libpng_public_hdrs
+  png.h
+  pngconf.h
+  ${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.h
+)
+set(libpng_sources
+  ${libpng_public_hdrs}
+  pngdebug.h
+  pnginfo.h
+  pngpriv.h
+  pngstruct.h
+  png.c
+  pngerror.c
+  pngget.c
+  pngmem.c
+  pngpread.c
+  pngread.c
+  pngrio.c
+  pngrtran.c
+  pngrutil.c
+  pngset.c
+  pngtrans.c
+  pngwio.c
+  pngwrite.c
+  pngwtran.c
+  pngwutil.c
+)
+set(pngtest_sources
+  pngtest.c
+)
+set(pngvalid_sources
+  contrib/libtests/pngvalid.c
+)
+# SOME NEEDED DEFINITIONS
+add_definitions(-DPNG_CONFIGURE_LIBPNG)
+if(MSVC)
+  add_definitions(-D_CRT_SECURE_NO_DEPRECATE)
+endif(MSVC)
+if(PNG_DEBUG)
+  add_definitions(-DPNG_DEBUG)
+endif()
+# NOW BUILD OUR TARGET
+include_directories(${CMAKE_CURRENT_SOURCE_DIR} ${ZLIB_INCLUDE_DIR})
+if(PNG_SHARED)
+  add_library(${PNG_LIB_NAME} SHARED ${libpng_sources})
+  if(MSVC)
+    # msvc does not append 'lib' - do it here to have consistent name
+    set_target_properties(${PNG_LIB_NAME} PROPERTIES PREFIX "lib")
+    set_target_properties(${PNG_LIB_NAME} PROPERTIES IMPORT_PREFIX "lib")
+  endif()
+  target_link_libraries(${PNG_LIB_NAME} ${ZLIB_LIBRARY} ${M_LIBRARY})
+endif()
+if(PNG_STATIC)
+# does not work without changing name
+  set(PNG_LIB_NAME_STATIC ${PNG_LIB_NAME}_static)
+  add_library(${PNG_LIB_NAME_STATIC} STATIC ${libpng_sources})
+  if(MSVC)
+    # msvc does not append 'lib' - do it here to have consistent name
+    set_target_properties(${PNG_LIB_NAME_STATIC} PROPERTIES PREFIX "lib")
+  endif()
+  target_link_libraries(${PNG_LIB_NAME_STATIC} ${ZLIB_LIBRARY} ${M_LIBRARY})
+endif()
+if(PNG_SHARED AND WIN32)
+  set_target_properties(${PNG_LIB_NAME} PROPERTIES DEFINE_SYMBOL PNG_BUILD_DLL)
+endif()
+if(PNG_TESTS AND PNG_SHARED)
+  # does not work with msvc due to png_lib_ver issue
+  add_executable(pngtest ${pngtest_sources})
+  target_link_libraries(pngtest ${PNG_LIB_NAME})
+  add_test(pngtest ./pngtest ${CMAKE_CURRENT_SOURCE_DIR}/pngtest.png)
+  #
+  add_executable(pngvalid ${pngvalid_sources})
+  target_link_libraries(pngvalid ${PNG_LIB_NAME})
+  add_test(pngvalid ./pngvalid)
+endif()
+# Ensure the CMAKE_LIBRARY_OUTPUT_DIRECTORY is set
+IF(NOT CMAKE_LIBRARY_OUTPUT_DIRECTORY)
+  IF(WIN32)
+    SET(CMAKE_LIBRARY_OUTPUT_DIRECTORY "bin")
+  ELSE(WIN32)
+    SET(CMAKE_LIBRARY_OUTPUT_DIRECTORY "lib")
+  ENDIF(WIN32)
+ENDIF(NOT CMAKE_LIBRARY_OUTPUT_DIRECTORY)
+# Set a variable with CMake code which:
+# Creates a symlink from src to dest (if possible) or alternatively
+# copies if different.
+macro(CREATE_SYMLINK SRC_FILE DEST_FILE)
+  FILE(REMOVE ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/${DEST_FILE})
+  if(WIN32 AND NOT CYGWIN AND NOT MINGW)
+    ADD_CUSTOM_COMMAND(
+        OUTPUT ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/${DEST_FILE}   ${CMAKE_CURRENT_BINARY_DIR}/${DEST_FILE}
+        COMMAND ${CMAKE_COMMAND} -E copy        ${CMAKE_CURRENT_BINARY_DIR}/${SRC_FILE} ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/${DEST_FILE}
+        COMMAND ${CMAKE_COMMAND} -E copy        ${CMAKE_CURRENT_BINARY_DIR}/${SRC_FILE} ${CMAKE_CURRENT_BINARY_DIR}/${DEST_FILE}
+        DEPENDS ${PNG_LIB_NAME} ${PNG_LIB_NAME_STATIC}
+        )
+    ADD_CUSTOM_TARGET(${DEST_FILE}_COPY ALL DEPENDS ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/${DEST_FILE})
+  else(WIN32 AND NOT CYGWIN AND NOT MINGW)
+    execute_process(COMMAND ${CMAKE_COMMAND} -E create_symlink ${SRC_FILE} ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/${DEST_FILE} WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR})
+    execute_process(COMMAND ${CMAKE_COMMAND} -E create_symlink ${SRC_FILE} ${DEST_FILE} WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR})
+  endif(WIN32 AND NOT CYGWIN AND NOT MINGW)
+endmacro()
+# libpng is a library so default to 'lib'
+if(NOT DEFINED CMAKE_INSTALL_LIBDIR)
+  set(CMAKE_INSTALL_LIBDIR lib)
+endif(NOT DEFINED CMAKE_INSTALL_LIBDIR)
+# CREATE PKGCONFIG FILES
+# we use the same files like ./configure, so we have to set its vars
+# Only do this on Windows for Cygwin - the files don't make much sense outside
+# a UNIX look alike
+if(NOT WIN32 OR CYGWIN OR MINGW) 
+  set(prefix      ${CMAKE_INSTALL_PREFIX})
+  set(exec_prefix ${CMAKE_INSTALL_PREFIX})
+  set(libdir      ${CMAKE_INSTALL_PREFIX}/${CMAKE_INSTALL_LIBDIR})
+  set(includedir  ${CMAKE_INSTALL_PREFIX}/include)
+  set(LIBS        "-lz -lm")
+  configure_file(${CMAKE_CURRENT_SOURCE_DIR}/libpng.pc.in
+    ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}.pc @ONLY)
+  CREATE_SYMLINK(${PNGLIB_NAME}.pc libpng.pc)
+  configure_file(${CMAKE_CURRENT_SOURCE_DIR}/libpng-config.in
+    ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}-config @ONLY)
+  CREATE_SYMLINK(${PNGLIB_NAME}-config libpng-config)
+endif(NOT WIN32 OR CYGWIN OR MINGW)
+# SET UP LINKS
+if(PNG_SHARED)
+  set_target_properties(${PNG_LIB_NAME} PROPERTIES
+#   VERSION 15.${PNGLIB_RELEASE}.1.5.9
+    VERSION 15.${PNGLIB_RELEASE}.0
+    SOVERSION 15
+    CLEAN_DIRECT_OUTPUT 1)
+endif()
+if(PNG_STATIC)
+  # MSVC doesn't use a different file extension for shared vs. static
+  # libs.  We are able to change OUTPUT_NAME to remove the _static
+  # for all other platforms.
+  if(NOT MSVC)
+    set_target_properties(${PNG_LIB_NAME_STATIC} PROPERTIES
+      OUTPUT_NAME ${PNG_LIB_NAME}
+      CLEAN_DIRECT_OUTPUT 1)
+  endif()
+endif()
+# If CMake > 2.4.x, we set a variable used below to export
+# targets to an export file.
+# TODO: Use VERSION_GREATER after our cmake_minimum_required >= 2.6.2
+if(CMAKE_MAJOR_VERSION GREATER 1 AND CMAKE_MINOR_VERSION GREATER 4)
+  set(PNG_EXPORT_RULE EXPORT libpng)
+elseif(CMAKE_MAJOR_VERSION GREATER 2) # future proof
+  set(PNG_EXPORT_RULE EXPORT libpng)
+endif()
+# INSTALL
+if(NOT SKIP_INSTALL_LIBRARIES AND NOT SKIP_INSTALL_ALL )
+  if(PNG_SHARED)
+    install(TARGETS ${PNG_LIB_NAME}
+        ${PNG_EXPORT_RULE}
+        RUNTIME DESTINATION bin
+        LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
+        ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR})
+    # Create a symlink for libpng.dll.a => libpng15.dll.a on Cygwin
+    if(CYGWIN OR MINGW)
+       get_target_property(BUILD_TARGET_LOCATION ${PNG_LIB_NAME} LOCATION_${CMAKE_BUILD_TYPE})
+       get_filename_component(BUILD_TARGET_FILE ${BUILD_TARGET_LOCATION} NAME)
+       CREATE_SYMLINK(${BUILD_TARGET_FILE} libpng${CMAKE_IMPORT_LIBRARY_SUFFIX})
+       install(FILES ${CMAKE_CURRENT_BINARY_DIR}/libpng${CMAKE_IMPORT_LIBRARY_SUFFIX}
+         DESTINATION ${CMAKE_INSTALL_LIBDIR})
+    endif(CYGWIN OR MINGW)
+    if(NOT WIN32)
+      get_target_property(BUILD_TARGET_LOCATION ${PNG_LIB_NAME} LOCATION_${CMAKE_BUILD_TYPE})
+      get_filename_component(BUILD_TARGET_FILE ${BUILD_TARGET_LOCATION} NAME)
+      CREATE_SYMLINK(${BUILD_TARGET_FILE} libpng${CMAKE_SHARED_LIBRARY_SUFFIX})
+      install(FILES ${CMAKE_CURRENT_BINARY_DIR}/libpng${CMAKE_SHARED_LIBRARY_SUFFIX}
+         DESTINATION ${CMAKE_INSTALL_LIBDIR})
+    endif(NOT WIN32)
+  endif(PNG_SHARED)
+  if(PNG_STATIC)
+    install(TARGETS ${PNG_LIB_NAME_STATIC}
+        ${PNG_EXPORT_RULE}
+        LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
+        ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR})
+    if(NOT WIN32 OR CYGWIN OR MINGW)
+      get_target_property(BUILD_TARGET_LOCATION ${PNG_LIB_NAME_STATIC} LOCATION_${CMAKE_BUILD_TYPE})
+      get_filename_component(BUILD_TARGET_FILE ${BUILD_TARGET_LOCATION} NAME)
+      CREATE_SYMLINK(${BUILD_TARGET_FILE} libpng${CMAKE_STATIC_LIBRARY_SUFFIX})
+      install(FILES ${CMAKE_CURRENT_BINARY_DIR}/libpng${CMAKE_STATIC_LIBRARY_SUFFIX}
+         DESTINATION ${CMAKE_INSTALL_LIBDIR})
+    endif(NOT WIN32 OR CYGWIN OR MINGW)
+ endif()
+endif()
+if(NOT SKIP_INSTALL_HEADERS AND NOT SKIP_INSTALL_ALL )
+  install(FILES ${libpng_public_hdrs}   DESTINATION include)
+  install(FILES ${libpng_public_hdrs}   DESTINATION include/${PNGLIB_NAME})
+endif()
+if(NOT SKIP_INSTALL_EXECUTABLES AND NOT SKIP_INSTALL_ALL )
+  if(NOT WIN32 OR CYGWIN OR MINGW)
+    install(PROGRAMS ${CMAKE_CURRENT_BINARY_DIR}/libpng-config DESTINATION bin)
+    install(PROGRAMS ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}-config
+            DESTINATION bin)
+  endif(NOT WIN32 OR CYGWIN OR MINGW)
+endif()
+if(NOT SKIP_INSTALL_FILES AND NOT SKIP_INSTALL_ALL )
+  # Install man pages
+  if(NOT PNG_MAN_DIR)
+    set(PNG_MAN_DIR "share/man")
+  endif()
+  install(FILES libpng.3 libpngpf.3      DESTINATION ${PNG_MAN_DIR}/man3)
+  install(FILES png.5                    DESTINATION ${PNG_MAN_DIR}/man5)
+  # Install pkg-config files
+  if(NOT WIN32 OR CYGWIN OR MINGW)
+    install(FILES ${CMAKE_CURRENT_BINARY_DIR}/libpng.pc
+            DESTINATION ${CMAKE_INSTALL_LIBDIR}/pkgconfig)
+    install(PROGRAMS ${CMAKE_CURRENT_BINARY_DIR}/libpng-config
+            DESTINATION bin)
+    install(FILES ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}.pc
+            DESTINATION ${CMAKE_INSTALL_LIBDIR}/pkgconfig)
+    install(PROGRAMS ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}-config
+            DESTINATION bin)
+  endif(NOT WIN32 OR CYGWIN OR MINGW)
+endif()
+# On versions of CMake that support it, create an export file CMake
+# users can include() to import our targets
+if(PNG_EXPORT_RULE AND NOT SKIP_INSTALL_EXPORT AND NOT SKIP_INSTALL_ALL )
+  install(EXPORT libpng DESTINATION lib/libpng FILE lib${PNG_LIB_NAME}.cmake)
+endif()
+# what's with libpng-$VER%.txt and all the extra files?
+# UNINSTALL
+# do we need this?
+# DIST
+# do we need this?
+# to create msvc import lib for mingw compiled shared lib
+# pexports libpng.dll > libpng.def
+# lib /def:libpng.def /machine:x86
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/INSTALL b/libraries/irrlicht-1.8/source/Irrlicht/libpng/INSTALL
new file mode 100644
index 0000000..c2d6c9e
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/INSTALL
@@ -0,0 +1,135 @@
+Installing libpng
+On Unix/Linux and similar systems, you can simply type
+    ./configure [--prefix=/path]
+    make check
+    make install
+and ignore the rest of this document.
+If configure does not work on your system and you have a reasonably
+up-to-date set of tools, running ./autogen.sh before running ./configure
+may fix the problem.  You can also run the individual commands in
+autogen.sh with the --force option, if supported by your version of
+the tools.  To be really sure that you aren't using any of the included
+pre-built scripts, you can do this:
+    ./configure --enable-maintainer-mode
+    make maintainer-clean
+    ./autogen.sh
+    ./configure [--prefix=/path] [other options]
+    make
+    make install
+    make check
+Instead, you can use one of the custom-built makefiles in the
+"scripts" directory
+    cp scripts/makefile.system makefile
+    make test
+    make install
+The files that are presently available in the scripts directory
+are listed and described in scripts/README.txt.
+Or you can use one of the "projects" in the "projects" directory.
+Before installing libpng, you must first install zlib, if it
+is not already on your system.  zlib can usually be found
+wherever you got libpng.  zlib can be placed in another directory,
+at the same level as libpng.
+If you want to use "cmake" (see www.cmake.org), type
+   cmake . -DCMAKE_INSTALL_PREFIX=/path
+   make
+   make install
+If your system already has a preinstalled zlib you will still need
+to have access to the zlib.h and zconf.h include files that
+correspond to the version of zlib that's installed.
+You can rename the directories that you downloaded (they
+might be called "libpng-x.y.z" or "libpngNN" and "zlib-1.2.5"
+or "zlib125") so that you have directories called "zlib" and "libpng".
+Your directory structure should look like this:
+   ..       (the parent directory)
+      libpng  (this directory)
+          INSTALL (this file)
+          README
+          *.h
+          *.c
+          CMakeLists.txt    =>  "cmake" script
+          configuration files:
+             configure.ac, configure, Makefile.am, Makefile.in,
+             autogen.sh, config.guess, ltmain.sh, missing, libpng.pc.in,
+             libpng-config.in, aclocal.m4, config.h.in, config.sub,
+             depcomp, install-sh, mkinstalldirs, test-pngtest.sh
+          contrib
+             gregbook
+             pngminim
+             pngminus
+             pngsuite
+             visupng
+          projects
+             visualc71
+             vstudio
+          scripts
+             makefile.*
+             *.def (module definition files)
+             etc.
+          pngtest.png
+          etc.
+      zlib
+          README
+          *.h
+          *.c
+          contrib
+          etc.
+If the line endings in the files look funny, you may wish to get the other
+distribution of libpng.  It is available in both tar.gz (UNIX style line
+endings) and zip (DOS style line endings) formats.
+If you are building libpng with MSVC, you can enter the
+libpng projects\visualc6 or visualc71 directory and follow the instructions
+in README.txt.
+Otherwise enter the zlib directory and follow the instructions in zlib/README,
+then come back here and run "configure" or choose the appropriate
+makefile.sys in the scripts directory.
+Copy the file (or files) that you need from the
+scripts directory into this directory, for example
+   MSDOS example: copy scripts\makefile.msc makefile
+   UNIX example:    cp scripts/makefile.std makefile
+Read the makefile to see if you need to change any source or
+target directories to match your preferences.
+Then read pnglibconf.dfa to see if you want to make any configuration
+changes.
+Then just run "make" which will create the libpng library in
+this directory and "make test" which will run a quick test that reads
+the "pngtest.png" file and writes a "pngout.png" file that should be
+identical to it.  Look for "9782 zero samples" in the output of the
+test.  For more confidence, you can run another test by typing
+"pngtest pngnow.png" and looking for "289 zero samples" in the output.
+Also, you can run "pngtest -m contrib/pngsuite/*.png" and compare
+your output with the result shown in contrib/pngsuite/README.
+Most of the makefiles will allow you to run "make install" to
+put the library in its final resting place (if you want to
+do that, run "make install" in the zlib directory first if necessary).
+Some also allow you to run "make test-installed" after you have
+run "make install".
+Further information can be found in the README and libpng-manual.txt
+files, in the individual makefiles, in png.h, and the manual pages
+libpng.3 and png.5.
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/LICENSE b/libraries/irrlicht-1.8/source/Irrlicht/libpng/LICENSE
new file mode 100644
index 0000000..0c92740
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/LICENSE
@@ -0,0 +1,111 @@
+This copy of the libpng notices is provided for your convenience.  In case of
+any discrepancy between this copy and the notices in the file png.h that is
+included in the libpng distribution, the latter shall prevail.
+COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
+If you modify libpng you may insert additional notices immediately following
+this sentence.
+This code is released under the libpng license.
+libpng versions 1.2.6, August 15, 2004, through 1.5.9, February 18, 2012, are
+Copyright (c) 2004, 2006-2011 Glenn Randers-Pehrson, and are
+distributed according to the same disclaimer and license as libpng-1.2.5
+with the following individual added to the list of Contributing Authors
+   Cosmin Truta
+libpng versions 1.0.7, July 1, 2000, through 1.2.5 - October 3, 2002, are
+Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are
+distributed according to the same disclaimer and license as libpng-1.0.6
+with the following individuals added to the list of Contributing Authors
+   Simon-Pierre Cadieux
+   Eric S. Raymond
+   Gilles Vollant
+and with the following additions to the disclaimer:
+   There is no warranty against interference with your enjoyment of the
+   library or against infringement.  There is no warranty that our
+   efforts or the library will fulfill any of your particular purposes
+   or needs.  This library is provided with all faults, and the entire
+   risk of satisfactory quality, performance, accuracy, and effort is with
+   the user.
+libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
+Copyright (c) 1998, 1999 Glenn Randers-Pehrson, and are
+distributed according to the same disclaimer and license as libpng-0.96,
+with the following individuals added to the list of Contributing Authors:
+   Tom Lane
+   Glenn Randers-Pehrson
+   Willem van Schaik
+libpng versions 0.89, June 1996, through 0.96, May 1997, are
+Copyright (c) 1996, 1997 Andreas Dilger
+Distributed according to the same disclaimer and license as libpng-0.88,
+with the following individuals added to the list of Contributing Authors:
+   John Bowler
+   Kevin Bracey
+   Sam Bushell
+   Magnus Holmgren
+   Greg Roelofs
+   Tom Tanner
+libpng versions 0.5, May 1995, through 0.88, January 1996, are
+Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
+For the purposes of this copyright and license, "Contributing Authors"
+is defined as the following set of individuals:
+   Andreas Dilger
+   Dave Martindale
+   Guy Eric Schalnat
+   Paul Schmidt
+   Tim Wegner
+The PNG Reference Library is supplied "AS IS".  The Contributing Authors
+and Group 42, Inc. disclaim all warranties, expressed or implied,
+including, without limitation, the warranties of merchantability and of
+fitness for any purpose.  The Contributing Authors and Group 42, Inc.
+assume no liability for direct, indirect, incidental, special, exemplary,
+or consequential damages, which may result from the use of the PNG
+Reference Library, even if advised of the possibility of such damage.
+Permission is hereby granted to use, copy, modify, and distribute this
+source code, or portions hereof, for any purpose, without fee, subject
+to the following restrictions:
+1. The origin of this source code must not be misrepresented.
+2. Altered versions must be plainly marked as such and must not
+   be misrepresented as being the original source.
+3. This Copyright notice may not be removed or altered from any
+   source or altered source distribution.
+The Contributing Authors and Group 42, Inc. specifically permit, without
+fee, and encourage the use of this source code as a component to
+supporting the PNG file format in commercial products.  If you use this
+source code in a product, acknowledgment is not required but would be
+appreciated.
+A "png_get_copyright" function is available, for convenient use in "about"
+boxes and the like:
+   printf("%s",png_get_copyright(NULL));
+Also, the PNG logo (in PNG format, of course) is supplied in the
+files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
+Libpng is OSI Certified Open Source Software.  OSI Certified Open Source is a
+certification mark of the Open Source Initiative.
+Glenn Randers-Pehrson
+glennrp at users.sourceforge.net
+February 18, 2012
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/README b/libraries/irrlicht-1.8/source/Irrlicht/libpng/README
new file mode 100644
index 0000000..c648a5a
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/README
@@ -0,0 +1,202 @@
+README for libpng version 1.5.9 - February 18, 2012 (shared library 15.0)
+See the note about version numbers near the top of png.h
+See INSTALL for instructions on how to install libpng.
+Libpng comes in several distribution formats.  Get libpng-*.tar.gz,
+libpng-*.tar.xz or libpng-*.tar.bz2 if you want UNIX-style line endings
+in the text files, or lpng*.zip if you want DOS-style line endings.
+Version 0.89 was the first official release of libpng.  Don't let the
+fact that it's the first release fool you.  The libpng library has been in
+extensive use and testing since mid-1995.  By late 1997 it had
+finally gotten to the stage where there hadn't been significant
+changes to the API in some time, and people have a bad feeling about
+libraries with versions < 1.0.  Version 1.0.0 was released in
+March 1998.
+****
+Note that some of the changes to the png_info structure render this
+version of the library binary incompatible with libpng-0.89 or
+earlier versions if you are using a shared library.  The type of the
+"filler" parameter for png_set_filler() has changed from png_byte to
+png_uint_32, which will affect shared-library applications that use
+this function.
+To avoid problems with changes to the internals of png_info_struct,
+new APIs have been made available in 0.95 to avoid direct application
+access to info_ptr.  These functions are the png_set_<chunk> and
+png_get_<chunk> functions.  These functions should be used when
+accessing/storing the info_struct data, rather than manipulating it
+directly, to avoid such problems in the future.
+It is important to note that the APIs do not make current programs
+that access the info struct directly incompatible with the new
+library.  However, it is strongly suggested that new programs use
+the new APIs (as shown in example.c and pngtest.c), and older programs
+be converted to the new format, to facilitate upgrades in the future.
+****
+Additions since 0.90 include the ability to compile libpng as a
+Windows DLL, and new APIs for accessing data in the info struct.
+Experimental functions include the ability to set weighting and cost
+factors for row filter selection, direct reads of integers from buffers
+on big-endian processors that support misaligned data access, faster
+methods of doing alpha composition, and more accurate 16->8 bit color
+conversion.
+The additions since 0.89 include the ability to read from a PNG stream
+which has had some (or all) of the signature bytes read by the calling
+application.  This also allows the reading of embedded PNG streams that
+do not have the PNG file signature.  As well, it is now possible to set
+the library action on the detection of chunk CRC errors.  It is possible
+to set different actions based on whether the CRC error occurred in a
+critical or an ancillary chunk.
+The changes made to the library, and bugs fixed are based on discussions
+on the PNG-implement mailing list and not on material submitted
+privately to Guy, Andreas, or Glenn.  They will forward any good
+suggestions to the list.
+For a detailed description on using libpng, read libpng-manual.txt.  For
+examples of libpng in a program, see example.c and pngtest.c.  For usage
+information and restrictions (what little they are) on libpng, see
+png.h.  For a description on using zlib (the compression library used by
+libpng) and zlib's restrictions, see zlib.h
+I have included a general makefile, as well as several machine and
+compiler specific ones, but you may have to modify one for your own needs.
+You should use zlib 1.0.4 or later to run this, but it MAY work with
+versions as old as zlib 0.95.  Even so, there are bugs in older zlib
+versions which can cause the output of invalid compression streams for
+some images.  You will definitely need zlib 1.0.4 or later if you are
+taking advantage of the MS-DOS "far" structure allocation for the small
+and medium memory models.  You should also note that zlib is a
+compression library that is useful for more things than just PNG files.
+You can use zlib as a drop-in replacement for fread() and fwrite() if
+you are so inclined.
+zlib should be available at the same place that libpng is, or at.
+ftp://ftp.info-zip.org/pub/infozip/zlib
+You may also want a copy of the PNG specification.  It is available
+as an RFC, a W3C Recommendation, and an ISO/IEC Standard.  You can find
+these at http://www.libpng.org/pub/png/documents/
+This code is currently being archived at libpng.sf.net in the
+[DOWNLOAD] area, and on CompuServe, Lib 20 (PNG SUPPORT)
+at GO GRAPHSUP.  If you can't find it in any of those places,
+e-mail me, and I'll help you find it.
+If you have any code changes, requests, problems, etc., please e-mail
+them to me.  Also, I'd appreciate any make files or project files,
+and any modifications you needed to make to get libpng to compile,
+along with a #define variable to tell what compiler/system you are on.
+If you needed to add transformations to libpng, or wish libpng would
+provide the image in a different way, drop me a note (and code, if
+possible), so I can consider supporting the transformation.
+Finally, if you get any warning messages when compiling libpng
+(note: not zlib), and they are easy to fix, I'd appreciate the
+fix.  Please mention "libpng" somewhere in the subject line.  Thanks.
+This release was created and will be supported by myself (of course
+based in a large way on Guy's and Andreas' earlier work), and the PNG
+development group.
+Send comments/corrections/commendations to png-mng-implement at
+lists.sourceforge.net (subscription required; visit 
+https://lists.sourceforge.net/lists/listinfo/png-mng-implement
+to subscribe) or to glennrp at users.sourceforge.net
+You can't reach Guy, the original libpng author, at the addresses
+given in previous versions of this document.  He and Andreas will
+read mail addressed to the png-implement list, however.
+Please do not send general questions about PNG.  Send them to
+png-mng-misc at lists.sf.net (subscription required; visit
+https://lists.sourceforge.net/lists/listinfo/png-mng-misc to
+subscribe).  If you have a question about something
+in the PNG specification that is related to using libpng, send it
+to me.  Send me any questions that start with "I was using libpng,
+and ...".  If in doubt, send questions to me.  I'll bounce them
+to others, if necessary.
+Please do not send suggestions on how to change PNG.  We have
+been discussing PNG for sixteen years now, and it is official and
+finished.  If you have suggestions for libpng, however, I'll
+gladly listen.  Even if your suggestion is not used immediately,
+it may be used later.
+Files in this distribution:
+      ANNOUNCE      =>  Announcement of this version, with recent changes
+      CHANGES       =>  Description of changes between libpng versions
+      KNOWNBUG      =>  List of known bugs and deficiencies
+      LICENSE       =>  License to use and redistribute libpng
+      README        =>  This file
+      TODO          =>  Things not implemented in the current library
+      Y2KINFO       =>  Statement of Y2K compliance
+      example.c     =>  Example code for using libpng functions
+      libpng.3      =>  manual page for libpng (includes libpng-manual.txt)
+      libpng-manual.txt  =>  Description of libpng and its functions
+      libpngpf.3    =>  manual page for libpng's private functions
+      png.5         =>  manual page for the PNG format
+      png.c         =>  Basic interface functions common to library
+      png.h         =>  Library function and interface declarations (public)
+      pngpriv.h     =>  Library function and interface declarations (private)
+      pngconf.h     =>  System specific library configuration (public)
+      pngstruct.h   =>  png_struct declaration (private)
+      pnginfo.h     =>  png_info struct declaration (private)
+      pngdebug.h    =>  debugging macros (private)
+      pngerror.c    =>  Error/warning message I/O functions
+      pngget.c      =>  Functions for retrieving info from struct
+      pngmem.c      =>  Memory handling functions
+      pngbar.png    =>  PNG logo, 88x31
+      pngnow.png    =>  PNG logo, 98x31
+      pngpread.c    =>  Progressive reading functions
+      pngread.c     =>  Read data/helper high-level functions
+      pngrio.c      =>  Lowest-level data read I/O functions
+      pngrtran.c    =>  Read data transformation functions
+      pngrutil.c    =>  Read data utility functions
+      pngset.c      =>  Functions for storing data into the info_struct
+      pngtest.c     =>  Library test program
+      pngtest.png   =>  Library test sample image
+      pngtrans.c    =>  Common data transformation functions
+      pngwio.c      =>  Lowest-level write I/O functions
+      pngwrite.c    =>  High-level write functions
+      pngwtran.c    =>  Write data transformations
+      pngwutil.c    =>  Write utility functions
+      contrib       =>  Contributions
+       gregbook         =>  source code for PNG reading and writing, from
+                            Greg Roelofs' "PNG: The Definitive Guide",
+                            O'Reilly, 1999
+       msvctest     =>  Builds and runs pngtest using a MSVC workspace
+       pngminus     =>  Simple pnm2png and png2pnm programs
+       pngsuite     =>  Test images
+       visupng      =>  Contains a MSVC workspace for VisualPng
+      projects      =>  Contains project files and workspaces for
+                        building a DLL
+       cbuilder5        =>  Contains a Borland workspace for building
+                            libpng and zlib
+       visualc6         =>  Contains a Microsoft Visual C++ (MSVC)
+                            workspace for building libpng and zlib
+       visualc71        =>  Contains a Microsoft Visual C++ (MSVC)
+                            workspace for building libpng and zlib
+       xcode            =>  Contains an Apple xcode
+                            workspace for building libpng and zlib
+      scripts       =>  Directory containing scripts for building libpng:
+                            (see scripts/README.txt for the list of scripts)
+Good luck, and happy coding.
+-Glenn Randers-Pehrson (current maintainer, since 1998)
+ Internet: glennrp at users.sourceforge.net
+-Andreas Eric Dilger (former maintainer, 1996-1997)
+ Internet: adilger at enel.ucalgary.ca
+ Web: http://www-mddsp.enel.ucalgary.ca/People/adilger/
+-Guy Eric Schalnat (original author and former maintainer, 1995-1996)
+ (formerly of Group 42, Inc)
+ Internet: gschal at infinet.com
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/TODO b/libraries/irrlicht-1.8/source/Irrlicht/libpng/TODO
new file mode 100644
index 0000000..b1660a4
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/TODO
@@ -0,0 +1,27 @@
+/*
+TODO - list of things to do for libpng:
+Final bug fixes.
+Better C++ wrapper/full C++ implementation?
+Fix problem with C++ and EXTERN "C".
+cHRM transformation.
+Remove setjmp/longjmp usage in favor of returning error codes.
+Add "grayscale->palette" transformation and "palette->grayscale" detection.
+Improved dithering.
+Multi-lingual error and warning message support.
+Complete sRGB transformation (presently it simply uses gamma=0.45455).
+Man pages for function calls.
+Better documentation.
+Better filter selection
+   (counting huffman bits/precompression?  filter inertia?  filter costs?).
+Histogram creation.
+Text conversion between different code pages (Latin-1 -> Mac and DOS).
+Avoid building gamma tables whenever possible.
+Use greater precision when changing to linear gamma for compositing against
+  background and doing rgb-to-gray transformation.
+Investigate pre-incremented loop counters and other loop constructions.
+Add interpolated method of handling interlacing.
+Switch to the simpler zlib (zlib/libpng) license if legally possible.
+Extend pngvalid.c to validate more of the libpng transformations.
+*/
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/configure b/libraries/irrlicht-1.8/source/Irrlicht/libpng/configure
new file mode 100644
index 0000000..9da0f74
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/configure
@@ -0,0 +1,19 @@
+echo "
+  There is no \"configure\" script in this distribution of
+  libpng-1.5.9.
+  Instead, please copy the appropriate makefile for your system from the
+  \"scripts\" directory.  Read the INSTALL file for more details.
+  Update, July 2004: you can get a \"configure\" based distribution
+  from the libpng distribution sites.  Download the file
+  libpng-1.5.9.tar.gz, libpng-1.5.9.tar.xz, or libpng-1.5.9.tar.bz2
+  If the line endings in the files look funny, which is likely to be the
+  case if you were trying to run \"configure\" on a Linux machine, you may
+  wish to get the other distribution of libpng.  It is available in both
+  tar.gz/tar.xz (UNIX style line endings) and .7z/.zip (DOS style line
+  endings) formats.
+"
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/README.txt b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/README.txt
new file mode 100644
index 0000000..7e9b7d0
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/README.txt
@@ -0,0 +1,4 @@
+This "contrib" directory contains contributions which are not necessarily under
+the libpng license, although all are open source.  They are not part of
+libpng proper and are not used for building the library.
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/COPYING b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/COPYING
new file mode 100644
index 0000000..c2d382b
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/COPYING
@@ -0,0 +1,340 @@
+                    GNU GENERAL PUBLIC LICENSE
+                       Version 2, June 1991
+ Copyright (C) 1989, 1991 Free Software Foundation, Inc.
+     59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+                            Preamble
+  The licenses for most software are designed to take away your
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+License is intended to guarantee your freedom to share and change free
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+General Public License applies to most of the Free Software
+Foundation's software and to any other program whose authors commit to
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+the GNU Library General Public License instead.)  You can apply it to
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+  When we speak of free software, we are referring to freedom, not
+price.  Our General Public Licenses are designed to make sure that you
+have the freedom to distribute copies of free software (and charge for
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+   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
+  0. This License applies to any program or other work which contains
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+under the terms of this General Public License.  The "Program", below,
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+Activities other than copying, distribution and modification are not
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+You may charge a fee for the physical act of transferring a copy, and
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+PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGES.
+                     END OF TERMS AND CONDITIONS
+            How to Apply These Terms to Your New Programs
+  If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
+  To do so, attach the following notices to the program.  It is safest
+to attach them to the start of each source file to most effectively
+convey the exclusion of warranty; and each file should have at least
+the "copyright" line and a pointer to where the full notice is found.
+    <one line to give the program's name and a brief idea of what it does.>
+    Copyright (C) <year>  <name of author>
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+Also add information on how to contact you by electronic and paper mail.
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+    Gnomovision version 69, Copyright (C) year  name of author
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+    This is free software, and you are welcome to redistribute it
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+The hypothetical commands `show w' and `show c' should show the appropriate
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+  Yoyodyne, Inc., hereby disclaims all copyright interest in the program
+  `Gnomovision' (which makes passes at compilers) written by James Hacker.
+  <signature of Ty Coon>, 1 April 1989
+  Ty Coon, President of Vice
+This General Public License does not permit incorporating your program into
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+library.  If this is what you want to do, use the GNU Library General
+Public License instead of this License.
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/LICENSE b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/LICENSE
new file mode 100644
index 0000000..40a0c8e
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/LICENSE
@@ -0,0 +1,50 @@
+  ---------------------------------------------------------------------------
+      Copyright (c) 1998-2008 Greg Roelofs.  All rights reserved.
+      This software is provided "as is," without warranty of any kind,
+      express or implied.  In no event shall the author or contributors
+      be held liable for any damages arising in any way from the use of
+      this software.
+      The contents of this file are DUAL-LICENSED.  You may modify and/or
+      redistribute this software according to the terms of one of the
+      following two licenses (at your option):
+      LICENSE 1 ("BSD-like with advertising clause"):
+      Permission is granted to anyone to use this software for any purpose,
+      including commercial applications, and to alter it and redistribute
+      it freely, subject to the following restrictions:
+      1. Redistributions of source code must retain the above copyright
+         notice, disclaimer, and this list of conditions.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, disclaimer, and this list of conditions in the documenta-
+         tion and/or other materials provided with the distribution.
+      3. All advertising materials mentioning features or use of this
+         software must display the following acknowledgment:
+            This product includes software developed by Greg Roelofs
+            and contributors for the book, "PNG: The Definitive Guide,"
+            published by O'Reilly and Associates.
+      LICENSE 2 (GNU GPL v2 or later):
+      This program is free software; you can redistribute it and/or modify
+      it under the terms of the GNU General Public License as published by
+      the Free Software Foundation; either version 2 of the License, or
+      (at your option) any later version.
+      This program is distributed in the hope that it will be useful,
+      but WITHOUT ANY WARRANTY; without even the implied warranty of
+      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+      GNU General Public License for more details.
+      You should have received a copy of the GNU General Public License
+      along with this program; if not, write to the Free Software Foundation,
+      Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+  ---------------------------------------------------------------------------
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/Makefile.mingw32 b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/Makefile.mingw32
new file mode 100644
index 0000000..a736556
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/Makefile.mingw32
@@ -0,0 +1,130 @@
+# Sample makefile for rpng-win / rpng2-win / wpng using mingw32-gcc and make.
+# Greg Roelofs
+# Last modified:  2 June 2007
+#
+#       The programs built by this makefile are described in the book,
+#       "PNG:  The Definitive Guide," by Greg Roelofs (O'Reilly and
+#       Associates, 1999).  Go buy a copy, eh?  Well, OK, it's not
+#       generally for sale anymore, but it's the thought that counts,
+#       right?  (Hint:  http://www.libpng.org/pub/png/book/ )
+#
+# Invoke this makefile from a DOS-prompt window via:
+#
+#       make -f Makefile.mingw32
+#
+# This makefile assumes libpng and zlib have already been built or downloaded
+# and are in subdirectories at the same level as the current subdirectory
+# (as indicated by the PNGDIR and ZDIR macros below).  It makes no assumptions
+# at all about the mingw32 installation tree (W32DIR).  Edit as appropriate.
+#
+# Note that the names of the dynamic and static libpng and zlib libraries
+# used below may change in later releases of the libraries.  This makefile
+# builds both statically and dynamically linked executables by default.
+# (You need only one set, but for testing it can be handy to have both.)
+# macros --------------------------------------------------------------------
+#PNGDIR = ../..#                for libpng-x.y.z/contrib/gregbook builds
+PNGDIR = ../libpng-win32
+PNGINC = -I$(PNGDIR)
+PNGLIBd = $(PNGDIR)/libpng.dll.a        # dynamically linked
+PNGLIBs = $(PNGDIR)/libpng.a            # statically linked, local libpng
+#ZDIR = ../../../zlib-win32#    for libpng-x.y.z/contrib/gregbook builds
+ZDIR = ../zlib-win32
+ZINC = -I$(ZDIR)
+ZLIBd = $(ZDIR)/libzdll.a
+ZLIBs = $(ZDIR)/libz.a
+# change this to be the path where mingw32 installs its stuff:
+W32DIR =
+#W32DIR = /usr/local/cross-tools/i386-mingw32msvc
+W32INC = -I$(W32DIR)/include
+W32LIB = $(W32DIR)/lib/libuser32.a $(W32DIR)/lib/libgdi32.a
+CC = gcc
+#CC = i386-mingw32msvc-gcc #    e.g., Linux -> Win32 cross-compilation
+LD = $(CC)
+RM = rm -f
+CFLAGS = -O -Wall $(INCS) $(MINGW_CCFLAGS)
+# [note that -Wall is a gcc-specific compilation flag ("most warnings on")]
+# [-ansi, -pedantic and -W can also be used]
+LDFLAGS = $(MINGW_LDFLAGS)
+O = .o
+E = .exe
+INCS = $(PNGINC) $(ZINC) $(W32INC)
+RLIBSd = $(PNGLIBd) $(ZLIBd) $(W32LIB) -lm
+RLIBSs = $(PNGLIBs) $(ZLIBs) $(W32LIB) -lm
+WLIBSd = $(PNGLIBd) $(ZLIBd)
+WLIBSs = $(PNGLIBs) $(ZLIBs)
+RPNG   = rpng-win
+RPNG2  = rpng2-win
+WPNG   = wpng
+ROBJSd  = $(RPNG)$(O) readpng.pic$(O)
+ROBJS2d = $(RPNG2)$(O) readpng2.pic$(O)
+WOBJSd  = $(WPNG)$(O) writepng.pic$(O)
+RPNGs  = $(RPNG)-static
+RPNG2s = $(RPNG2)-static
+WPNGs  = $(WPNG)-static
+ROBJSs  = $(RPNG)$(O) readpng$(O)
+ROBJS2s = $(RPNG2)$(O) readpng2$(O)
+WOBJSs  = $(WPNG)$(O) writepng$(O)
+STATIC_EXES  = $(RPNGs)$(E) $(RPNG2s)$(E) $(WPNGs)$(E)
+DYNAMIC_EXES = $(RPNG)$(E) $(RPNG2)$(E) $(WPNG)$(E)
+EXES = $(STATIC_EXES) $(DYNAMIC_EXES)
+# implicit make rules -------------------------------------------------------
+.c$(O):
+        $(CC) -c $(CFLAGS) $<
+%.pic$(O): %.c
+        $(CC) -c $(CFLAGS) -DPNG_BUILD_DLL -o $@ $<
+# dependencies --------------------------------------------------------------
+all:  $(EXES)
+$(RPNGs)$(E): $(ROBJSs)
+        $(LD) $(LDFLAGS) -o $@ $(ROBJSs) $(RLIBSs)
+$(RPNG)$(E): $(ROBJSd)
+        $(LD) $(LDFLAGS) -o $@ $(ROBJSd) $(RLIBSd)
+$(RPNG2s)$(E): $(ROBJS2s)
+        $(LD) $(LDFLAGS) -o $@ $(ROBJS2s) $(RLIBSs)
+$(RPNG2)$(E): $(ROBJS2d)
+        $(LD) $(LDFLAGS) -o $@ $(ROBJS2d) $(RLIBSd)
+$(WPNGs)$(E): $(WOBJSs)
+        $(LD) $(LDFLAGS) -o $@ $(WOBJSs) $(WLIBSs)
+$(WPNG)$(E): $(WOBJSd)
+        $(LD) $(LDFLAGS) -o $@ $(WOBJSd) $(WLIBSd)
+$(RPNG)$(O):    $(RPNG).c readpng.h
+$(RPNG2)$(O):   $(RPNG2).c readpng2.h
+$(WPNG)$(O):    $(WPNG).c writepng.h
+readpng$(O) readpng.pic$(O):    readpng.c readpng.h
+readpng2$(O) readpng2.pic$(O):  readpng2.c readpng2.h
+writepng$(O) writepng.pic$(O):  writepng.c writepng.h
+# maintenance ---------------------------------------------------------------
+clean:
+        $(RM) $(EXES)
+        $(RM) $(ROBJSs) $(ROBJS2s) $(WOBJSs)
+        $(RM) $(ROBJSd) $(ROBJS2d) $(WOBJSd)
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/Makefile.sgi b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/Makefile.sgi
new file mode 100644
index 0000000..8773a00
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/Makefile.sgi
@@ -0,0 +1,104 @@
+# Sample makefile for rpng-x / rpng2-x / wpng for SGI using cc and make.
+# Greg Roelofs
+# Last modified:  7 March 2002
+#
+#       The programs built by this makefile are described in the book,
+#       "PNG:  The Definitive Guide," by Greg Roelofs (O'Reilly and
+#       Associates, 1999).  Go buy a copy, eh?  Buy some for friends
+#       and family, too.  (Not that this is a blatant plug or anything.)
+#
+# Invoke this makefile from a shell prompt in the usual way; for example:
+#
+#       make -f Makefile.sgi
+#
+# This makefile assumes libpng and zlib have already been built or downloaded
+# and are both installed in /usr/local/{include,lib} (as indicated by the
+# PNG* and Z* macros below).  Edit as appropriate--choose only ONE each of
+# the PNGINC, PNGLIB, ZINC and ZLIB lines.
+#
+# This makefile builds dynamically linked executables (against libpng and zlib,
+# that is), but that can be changed by uncommenting the appropriate PNGLIB and
+# ZLIB lines.
+# macros --------------------------------------------------------------------
+PNGINC = -I/usr/local/include/libpng15
+PNGLIB = -L/usr/local/lib -lpng15         # dynamically linked against libpng
+#PNGLIB = /usr/local/lib/libpng15.a # statically linked against libpng
+# or:
+#PNGINC = -I../..
+#PNGLIB = -L../.. -lpng
+#PNGLIB = ../../libpng.a
+ZINC = -I/usr/local/include
+ZLIB = -L/usr/local/lib -lz             # dynamically linked against zlib
+#ZLIB = /usr/local/lib/libz.a           # statically linked against zlib
+#ZINC = -I../zlib
+#ZLIB = -L../zlib -lz
+#ZLIB = ../../../zlib/libz.a
+XINC = -I/usr/include/X11               # old-style, stock X distributions
+XLIB = -L/usr/lib/X11 -lX11
+#XINC = -I/usr/openwin/include          # Sun workstations (OpenWindows)
+#XLIB = -L/usr/openwin/lib -lX11
+#XINC = -I/usr/X11R6/include            # new X distributions (XFree86, etc.)
+#XLIB = -L/usr/X11R6/lib -lX11
+INCS = $(PNGINC) $(ZINC) $(XINC)
+RLIBS = $(PNGLIB) $(ZLIB) $(XLIB) -lm
+WLIBS = $(PNGLIB) $(ZLIB)
+CC = cc
+LD = cc
+RM = rm -f
+# ABI must be the same as that used to build libpng.
+ABI=
+CFLAGS = $(ABI) -O -fullwarn $(INCS)
+LDFLAGS = $(ABI)
+O = .o
+E =
+RPNG  = rpng-x
+RPNG2 = rpng2-x
+WPNG  = wpng
+ROBJS  = $(RPNG)$(O) readpng$(O)
+ROBJS2 = $(RPNG2)$(O) readpng2$(O)
+WOBJS  = $(WPNG)$(O) writepng$(O)
+EXES = $(RPNG)$(E) $(RPNG2)$(E) $(WPNG)$(E)
+# implicit make rules -------------------------------------------------------
+.c$(O):
+        $(CC) -c $(CFLAGS) $<
+# dependencies --------------------------------------------------------------
+all:  $(EXES)
+$(RPNG)$(E): $(ROBJS)
+        $(LD) $(LDFLAGS) -o $@ $(ROBJS) $(RLIBS)
+$(RPNG2)$(E): $(ROBJS2)
+        $(LD) $(LDFLAGS) -o $@ $(ROBJS2) $(RLIBS)
+$(WPNG)$(E): $(WOBJS)
+        $(LD) $(LDFLAGS) -o $@ $(WOBJS) $(WLIBS)
+$(RPNG)$(O):    $(RPNG).c readpng.h
+$(RPNG2)$(O):   $(RPNG2).c readpng2.h
+$(WPNG)$(O):    $(WPNG).c writepng.h
+readpng$(O):    readpng.c readpng.h
+readpng2$(O):   readpng2.c readpng2.h
+writepng$(O):   writepng.c writepng.h
+# maintenance ---------------------------------------------------------------
+clean:
+        $(RM) $(EXES) $(ROBJS) $(ROBJS2) $(WOBJS)
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/Makefile.unx b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/Makefile.unx
new file mode 100644
index 0000000..3bffc2f
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/Makefile.unx
@@ -0,0 +1,132 @@
+# Sample makefile for rpng-x / rpng2-x / wpng using gcc and make.
+# Greg Roelofs
+# Last modified:  2 June 2007
+#
+#       The programs built by this makefile are described in the book,
+#       "PNG:  The Definitive Guide," by Greg Roelofs (O'Reilly and
+#       Associates, 1999).  Go buy a copy, eh?  Well, OK, it's not
+#       generally for sale anymore, but it's the thought that counts,
+#       right?  (Hint:  http://www.libpng.org/pub/png/book/ )
+#
+# Invoke this makefile from a shell prompt in the usual way; for example:
+#
+#       make -f Makefile.unx
+#
+# This makefile assumes libpng and zlib have already been built or downloaded
+# and are installed in /usr/local/{include,lib} or as otherwise indicated by
+# the PNG* and Z* macros below.  Edit as appropriate--choose only ONE each of
+# the PNGINC, PNGLIBd, PNGLIBs, ZINC, ZLIBd and ZLIBs lines.
+#
+# This makefile builds both dynamically and statically linked executables
+# (against libpng and zlib, that is), but that can be changed by modifying
+# the "EXES =" line.  (You need only one set, but for testing it can be handy
+# to have both.)
+# macros --------------------------------------------------------------------
+#PNGDIR = /usr/local/lib
+#PNGINC = -I/usr/local/include/libpng15
+#PNGLIBd = -L$(PNGDIR) -lpng15 # dynamically linked, installed libpng
+#PNGLIBs = $(PNGDIR)/libpng15.a # statically linked, installed libpng
+# or:
+PNGDIR = ../..# this one is for libpng-x.y.z/contrib/gregbook builds
+#PNGDIR = ../libpng
+PNGINC = -I$(PNGDIR)
+PNGLIBd = -Wl,-rpath,$(PNGDIR) -L$(PNGDIR) -lpng15      # dynamically linked
+PNGLIBs = $(PNGDIR)/libpng.a            # statically linked, local libpng
+ZDIR = /usr/local/lib
+#ZDIR = /usr/lib64
+ZINC = -I/usr/local/include
+ZLIBd = -L$(ZDIR) -lz                   # dynamically linked against zlib
+ZLIBs = $(ZDIR)/libz.a                  # statically linked against zlib
+# or:
+#ZDIR = ../zlib
+#ZINC = -I$(ZDIR)
+#ZLIBd = -Wl,-rpath,$(ZDIR) -L$(ZDIR) -lz  # -rpath allows in-place testing
+#ZLIBs = $(ZDIR)/libz.a
+#XINC = -I/usr/include                  # old-style, stock X distributions
+#XLIB = -L/usr/lib/X11 -lX11            #  (including SGI IRIX)
+#XINC = -I/usr/openwin/include          # Sun workstations (OpenWindows)
+#XLIB = -L/usr/openwin/lib -lX11
+XINC = -I/usr/X11R6/include             # new X distributions (X.org, etc.)
+XLIB = -L/usr/X11R6/lib -lX11
+#XLIB = -L/usr/X11R6/lib64 -lX11        # e.g., Red Hat on AMD64
+INCS = $(PNGINC) $(ZINC) $(XINC)
+RLIBSd = $(PNGLIBd) $(ZLIBd) $(XLIB) -lm
+RLIBSs = $(PNGLIBs) $(ZLIBs) $(XLIB) -lm
+WLIBSd = $(PNGLIBd) $(ZLIBd) -lm
+WLIBSs = $(PNGLIBs) $(ZLIBs)
+CC = gcc
+LD = gcc
+RM = rm -f
+CFLAGS = -O -Wall $(INCS) -DFEATURE_LOOP
+# [note that -Wall is a gcc-specific compilation flag ("most warnings on")]
+# [-ansi, -pedantic and -W can also be used]
+LDFLAGS =
+O = .o
+E =
+RPNG   = rpng-x
+RPNG2  = rpng2-x
+WPNG   = wpng
+RPNGs  = $(RPNG)-static
+RPNG2s = $(RPNG2)-static
+WPNGs  = $(WPNG)-static
+ROBJS  = $(RPNG)$(O) readpng$(O)
+ROBJS2 = $(RPNG2)$(O) readpng2$(O)
+WOBJS  = $(WPNG)$(O) writepng$(O)
+STATIC_EXES  = $(RPNGs)$(E) $(RPNG2s)$(E) $(WPNGs)$(E)
+DYNAMIC_EXES = $(RPNG)$(E) $(RPNG2)$(E) $(WPNG)$(E)
+EXES = $(STATIC_EXES) $(DYNAMIC_EXES)
+# implicit make rules -------------------------------------------------------
+.c$(O):
+        $(CC) -c $(CFLAGS) $<
+# dependencies --------------------------------------------------------------
+all:  $(EXES)
+$(RPNGs)$(E): $(ROBJS)
+        $(LD) $(LDFLAGS) -o $@ $(ROBJS) $(RLIBSs)
+$(RPNG)$(E): $(ROBJS)
+        $(LD) $(LDFLAGS) -o $@ $(ROBJS) $(RLIBSd)
+$(RPNG2s)$(E): $(ROBJS2)
+        $(LD) $(LDFLAGS) -o $@ $(ROBJS2) $(RLIBSs)
+$(RPNG2)$(E): $(ROBJS2)
+        $(LD) $(LDFLAGS) -o $@ $(ROBJS2) $(RLIBSd)
+$(WPNGs)$(E): $(WOBJS)
+        $(LD) $(LDFLAGS) -o $@ $(WOBJS) $(WLIBSs)
+$(WPNG)$(E): $(WOBJS)
+        $(LD) $(LDFLAGS) -o $@ $(WOBJS) $(WLIBSd)
+$(RPNG)$(O):    $(RPNG).c readpng.h
+$(RPNG2)$(O):   $(RPNG2).c readpng2.h
+$(WPNG)$(O):    $(WPNG).c writepng.h
+readpng$(O):    readpng.c readpng.h
+readpng2$(O):   readpng2.c readpng2.h
+writepng$(O):   writepng.c writepng.h
+# maintenance ---------------------------------------------------------------
+clean:
+        $(RM) $(EXES) $(ROBJS) $(ROBJS2) $(WOBJS)
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/Makefile.w32 b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/Makefile.w32
new file mode 100644
index 0000000..eced083
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/Makefile.w32
@@ -0,0 +1,113 @@
+# Sample makefile for rpng-win / rpng2-win / wpng using MSVC and NMAKE.
+# Greg Roelofs
+# Last modified:  2 June 2007
+#
+#       The programs built by this makefile are described in the book,
+#       "PNG:  The Definitive Guide," by Greg Roelofs (O'Reilly and
+#       Associates, 1999).  Go buy a copy, eh?  Well, OK, it's not
+#       generally for sale anymore, but it's the thought that counts,
+#       right?  (Hint:  http://www.libpng.org/pub/png/book/ )
+#
+# Invoke this makefile from a DOS prompt window via:
+#
+#       %devstudio%\vc\bin\vcvars32.bat
+#       nmake -nologo -f Makefile.w32
+#
+# where %devstudio% is the installation directory for MSVC / DevStudio.  If
+# you get "environment out of space" errors, create a desktop shortcut with
+# "c:\windows\command.com /e:4096" as the program command line and set the
+# working directory to this directory.  Then double-click to open the new
+# DOS-prompt window with a bigger environment and retry the commands above.
+#
+# This makefile assumes libpng and zlib have already been built or downloaded
+# and are in subdirectories at the same level as the current subdirectory
+# (as indicated by the PNGPATH and ZPATH macros below).  Edit as appropriate.
+#
+# Note that the names of the dynamic and static libpng and zlib libraries
+# used below may change in later releases of the libraries.  This makefile
+# builds statically linked executables, but that can be changed by uncom-
+# menting the appropriate PNGLIB and ZLIB lines.
+!include <ntwin32.mak>
+# macros --------------------------------------------------------------------
+PNGPATH = ../libpng
+PNGINC = -I$(PNGPATH)
+#PNGLIB = $(PNGPATH)/pngdll.lib
+PNGLIB = $(PNGPATH)/libpng.lib
+ZPATH = ../zlib
+ZINC = -I$(ZPATH)
+#ZLIB = $(ZPATH)/zlibdll.lib
+ZLIB = $(ZPATH)/zlibstat.lib
+WINLIBS = -defaultlib:user32.lib gdi32.lib
+# ["real" apps may also need comctl32.lib, comdlg32.lib, winmm.lib, etc.]
+INCS = $(PNGINC) $(ZINC)
+RLIBS = $(PNGLIB) $(ZLIB) $(WINLIBS)
+WLIBS = $(PNGLIB) $(ZLIB)
+CC = cl
+LD = link
+RM = del
+CFLAGS = -nologo -O -W3 $(INCS) $(cvars)
+# [note that -W3 is an MSVC-specific compilation flag ("all warnings on")]
+# [see %devstudio%\vc\include\win32.mak for cvars macro definition]
+O = .obj
+E = .exe
+RLDFLAGS = -nologo -subsystem:windows
+WLDFLAGS = -nologo
+RPNG  = rpng-win
+RPNG2 = rpng2-win
+WPNG  = wpng
+ROBJS  = $(RPNG)$(O) readpng$(O)
+ROBJS2 = $(RPNG2)$(O) readpng2$(O)
+WOBJS  = $(WPNG)$(O) writepng$(O)
+EXES = $(RPNG)$(E) $(RPNG2)$(E) $(WPNG)$(E)
+# implicit make rules -------------------------------------------------------
+.c$(O):
+        $(CC) -c $(CFLAGS) $<
+# dependencies --------------------------------------------------------------
+all:  $(EXES)
+$(RPNG)$(E): $(ROBJS)
+        $(LD) $(RLDFLAGS) -out:$@ $(ROBJS) $(RLIBS)
+$(RPNG2)$(E): $(ROBJS2)
+        $(LD) $(RLDFLAGS) -out:$@ $(ROBJS2) $(RLIBS)
+$(WPNG)$(E): $(WOBJS)
+        $(LD) $(WLDFLAGS) -out:$@ $(WOBJS) $(WLIBS)
+$(RPNG)$(O):    $(RPNG).c readpng.h
+$(RPNG2)$(O):   $(RPNG2).c readpng2.h
+$(WPNG)$(O):    $(WPNG).c writepng.h
+readpng$(O):    readpng.c readpng.h
+readpng2$(O):   readpng2.c readpng2.h
+writepng$(O):   writepng.c writepng.h
+# maintenance ---------------------------------------------------------------
+clean:
+#       ideally we could just do this:
+#       $(RM) $(EXES) $(ROBJS) $(ROBJS2) $(WOBJS)
+#       ...but the Windows "DEL" command is none too bright, so:
+        $(RM) r*$(E)
+        $(RM) w*$(E)
+        $(RM) r*$(O)
+        $(RM) w*$(O)
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/README b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/README
new file mode 100644
index 0000000..791fec8
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/README
@@ -0,0 +1,186 @@
+                     ===========================
+                      PNG: The Definitive Guide
+                     ===========================
+                             Source Code
+Chapters 13, 14 and 15 of "PNG: The Definitive Guide" discuss three free,
+cross-platform demo programs that show how to use the libpng reference
+library:  rpng, rpng2 and wpng.  rpng and rpng2 are viewers; the first is
+a very simple example that that shows how a standard file-viewer might use
+libpng, while the second is designed to process streaming data and shows
+how a web browser might be written.  wpng is a simple command-line program
+that reads binary PGM and PPM files (the ``raw'' grayscale and RGB subsets
+of PBMPLUS/NetPBM) and converts them to PNG.
+The source code for all three demo programs currently compiles under
+Unix, OpenVMS, and 32-bit Windows.  (Special thanks to Martin Zinser,
+zinser@decus.de, for making the necessary changes for OpenVMS and for
+providing an appropriate build script.)  Build instructions can be found
+below.
+Files:
+   README             this file
+   LICENSE            terms of distribution and reuse (BSD-like or GNU GPL)
+   COPYING            GNU General Public License (GPL)
+   Makefile.unx       Unix makefile
+   Makefile.w32       Windows (MSVC) makefile
+   makevms.com        OpenVMS build script
+   rpng-win.c         Windows front end for the basic viewer
+   rpng-x.c           X Window System (Unix, OpenVMS) front end
+   readpng.c          generic back end for the basic viewer
+   readpng.h          header file for the basic viewer
+   rpng2-win.c        Windows front end for the progressive viewer
+   rpng2-x.c          X front end for the progressive viewer
+   readpng2.c         generic back end for the progressive viewer
+   readpng2.h         header file for the progressive viewer
+   wpng.c             generic (text) front end for the converter
+   writepng.c         generic back end for the converter
+   writepng.h         header file for the converter
+   toucan.png         transparent PNG for testing (by Stefan Schneider)
+Note that, although the programs are designed to be functional, their
+primary purpose is to illustrate how to use libpng to add PNG support to
+other programs.  As such, their user interfaces are crude and definitely
+are not intended for everyday use.
+Please see http://www.libpng.org/pub/png/pngbook.html for further infor-
+mation and links to the latest version of the source code, and Chapters
+13-15 of the book for detailed discussion of the three programs.
+Greg Roelofs
+http://pobox.com/~newt/greg_contact.html
+16 March 2008
+BUILD INSTRUCTIONS
+ - Prerequisites (in order of compilation):
+      - zlib            http://zlib.net/
+      - libpng          http://www.libpng.org/pub/png/libpng.html
+      - pngbook         http://www.libpng.org/pub/png/book/sources.html
+     The pngbook demo programs are explicitly designed to demonstrate proper
+     coding techniques for using the libpng reference library.  As a result,
+     you need to download and build both zlib (on which libpng depends) and
+     libpng.  A common build setup is to place the zlib, libpng and pngbook
+     subdirectory trees ("folders") in the same parent directory.  Then the
+     libpng build can refer to files in ../zlib (or ..\zlib or [-.zlib]),
+     and similarly for the pngbook build.
+     Note that all three packages are designed to be built from a command
+     line by default; those who wish to use a graphical or other integrated
+     development environments are on their own.
+ - Unix:
+     Unpack the latest pngbook sources (which should correspond to this
+     README file) into a directory and change into that directory.
+     Copy Makefile.unx to Makefile and edit the PNG* and Z* variables
+     appropriately (possibly also the X* variables if necessary).
+     make
+     There is no "install" target, so copy the three executables somewhere
+     in your path or run them from the current directory.  All three will
+     print a basic usage screen when run without any command-line arguments;
+     see the book for more details.
+ - Windows:
+     Unpack the latest pngbook sources (which should correspond to this
+     README file) into a folder, open a "DOS shell" or "command prompt"
+     or equivalent command-line window, and cd into the folder where you
+     unpacked the source code.
+     For MSVC, set up the necessary environment variables by invoking
+        %devstudio%\vc\bin\vcvars32.bat
+     where where %devstudio% is the installation directory for MSVC /
+     DevStudio.  If you get "environment out of space" errors under 95/98,
+     create a desktop shortcut with "c:\windows\command.com /e:4096" as
+     the program command line and set the working directory to the pngbook
+     directory.  Then double-click to open the new DOS-prompt window with
+     a bigger environment and retry the commands above.
+     Copy Makefile.w32 to Makefile and edit the PNGPATH and ZPATH variables
+     appropriately (possibly also the "INC" and "LIB" variables if needed).
+     Note that the names of the dynamic and static libpng and zlib libraries
+     used in the makefile may change in later releases of the libraries.
+     Also note that, as of libpng version 1.0.5, MSVC DLL builds do not work.
+     This makefile therefore builds statically linked executables, but if
+     the DLL problems ever get fixed, uncommenting the appropriate PNGLIB
+     and ZLIB lines will build dynamically linked executables instead.
+     Do the build by typing
+        nmake
+     The result should be three executables:  rpng-win.exe, rpng2-win.exe,
+     and wpng.exe.  Copy them somewhere in your PATH or run them from the
+     current folder.  Like the Unix versions, the two windowed programs
+     (rpng and rpng2) now display a usage screen in a console window when
+     invoked without command-line arguments; this is new behavior as of
+     the June 2001 release.  Note that the programs use the Unix-style "-"
+     character to specify options, instead of the more common DOS/Windows
+     "/" character.  (For example:  "rpng2-win -bgpat 4 foo.png", not
+     "rpng2-win /bgpat 4 foo.png")
+ - OpenVMS:
+     Unpack the pngbook sources into a subdirectory and change into that
+     subdirectory.
+     Edit makevms.com appropriately, specifically the zpath and pngpath
+     variables.
+     @makevms
+     To run the programs, they probably first need to be set up as "foreign
+     symbols," with "disk" and "dir" set appropriately:
+     $ rpng  == "$disk:[dir]rpng-x.exe"
+     $ rpng2 == "$disk:[dir]rpng2-x.exe"
+     $ wpng  == "$disk:[dir]wpng.exe"
+     All three will print a basic usage screen when run without any command-
+     line arguments; see the book for more details.  Note that the options
+     style is Unix-like, i.e., preceded by "-" rather than "/".
+RUNNING THE PROGRAMS:  (VERY) BRIEF INTRO
+     rpng is a simple PNG viewer that can display transparent PNGs with a
+     specified background color; for example,
+        rpng -bgcolor \#ff0000 toucan.png
+     would display the image with a red background.  rpng2 is a progressive
+     viewer that simulates a web browser in some respects; it can display
+     images against either a background color or a dynamically generated
+     background image.  For example:
+        rpng2 -bgpat 16 toucan.png
+     wpng is a purely command-line image converter from binary PBMPLUS/NetPBM
+     format (.pgm or .ppm) to PNG; for example,
+        wpng -time < toucan-notrans.ppm > toucan-notrans.png
+     would convert the specified PPM file (using redirection) to PNG, auto-
+     matically setting the PNG modification-time chunk.
+     All options can be abbreviated to the shortest unique value; for example,
+     "-bgc" for -bgcolor (versus "-bgp" for -bgpat), or "-g" for -gamma.
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/makevms.com b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/makevms.com
new file mode 100644
index 0000000..29a5727
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/makevms.com
@@ -0,0 +1,132 @@
+$!------------------------------------------------------------------------------
+$! make "PNG: The Definitive Guide" demo programs (for X) under OpenVMS
+$!
+$! Script created by Martin Zinser for libpng; modified by Greg Roelofs
+$! for standalone pngbook source distribution.
+$!
+$!
+$!    Set locations where zlib and libpng sources live.
+$!
+$ zpath   = ""
+$ pngpath = ""
+$!
+$ if f$search("[---.zlib]zlib.h").nes."" then zpath = "[---.zlib]"
+$ if f$search("[--]png.h").nes."" then pngpath = "[--]"
+$!
+$ if f$search("[-.zlib]zlib.h").nes."" then zpath = "[-.zlib]"
+$ if f$search("[-.libpng]png.h").nes."" then pngpath = "[-.libpng]"
+$!
+$ if zpath .eqs. ""
+$ then
+$   write sys$output "zlib include not found. Exiting..."
+$   exit 2
+$ endif
+$!
+$ if pngpath .eqs. ""
+$ then
+$   write sys$output "libpng include not found. Exiting..."
+$   exit 2
+$ endif
+$!
+$!    Look for the compiler used.
+$!
+$ ccopt="/include=(''zpath',''pngpath')"
+$ if f$getsyi("HW_MODEL").ge.1024
+$ then
+$  ccopt = "/prefix=all"+ccopt
+$  comp  = "__decc__=1"
+$  if f$trnlnm("SYS").eqs."" then define sys sys$library:
+$ else
+$  if f$search("SYS$SYSTEM:DECC$COMPILER.EXE").eqs.""
+$   then
+$    if f$trnlnm("SYS").eqs."" then define sys sys$library:
+$    if f$search("SYS$SYSTEM:VAXC.EXE").eqs.""
+$     then
+$      comp  = "__gcc__=1"
+$      CC :== GCC
+$     else
+$      comp = "__vaxc__=1"
+$     endif
+$   else
+$    if f$trnlnm("SYS").eqs."" then define sys decc$library_include:
+$    ccopt = "/decc/prefix=all"+ccopt
+$    comp  = "__decc__=1"
+$  endif
+$ endif
+$ open/write lopt lib.opt
+$ write lopt "''pngpath'libpng.olb/lib"
+$ write lopt "''zpath'libz.olb/lib"
+$ close lopt
+$ open/write xopt x11.opt
+$ write xopt "sys$library:decw$xlibshr.exe/share"
+$ close xopt
+$!
+$!    Build 'em.
+$!
+$ write sys$output "Compiling PNG book programs ..."
+$   CALL MAKE readpng.OBJ "cc ''CCOPT' readpng" -
+        readpng.c readpng.h
+$   CALL MAKE readpng2.OBJ "cc ''CCOPT' readpng2" -
+        readpng2.c readpng2.h
+$   CALL MAKE writepng.OBJ "cc ''CCOPT' writepng" -
+        writepng.c writepng.h
+$   write sys$output "Building rpng-x..."
+$   CALL MAKE rpng-x.OBJ "cc ''CCOPT' rpng-x" -
+        rpng-x.c readpng.h
+$   call make rpng-x.exe -
+        "LINK rpng-x,readpng,lib.opt/opt,x11.opt/opt" -
+        rpng-x.obj readpng.obj
+$   write sys$output "Building rpng2-x..."
+$   CALL MAKE rpng2-x.OBJ "cc ''CCOPT' rpng2-x" -
+        rpng2-x.c readpng2.h
+$   call make rpng2-x.exe -
+        "LINK rpng2-x,readpng2,lib.opt/opt,x11.opt/opt" -
+        rpng2-x.obj readpng2.obj
+$   write sys$output "Building wpng..."
+$   CALL MAKE wpng.OBJ "cc ''CCOPT' wpng" -
+        wpng.c writepng.h
+$   call make wpng.exe -
+        "LINK wpng,writepng,lib.opt/opt" -
+        wpng.obj writepng.obj
+$ exit
+$!
+$!
+$MAKE: SUBROUTINE   !SUBROUTINE TO CHECK DEPENDENCIES
+$ V = 'F$Verify(0)
+$! P1 = What we are trying to make
+$! P2 = Command to make it
+$! P3 - P8  What it depends on
+$
+$ If F$Search(P1) .Eqs. "" Then Goto Makeit
+$ Time = F$CvTime(F$File(P1,"RDT"))
+$arg=3
+$Loop:
+$       Argument = P'arg
+$       If Argument .Eqs. "" Then Goto Exit
+$       El=0
+$Loop2:
+$       File = F$Element(El," ",Argument)
+$       If File .Eqs. " " Then Goto Endl
+$       AFile = ""
+$Loop3:
+$       OFile = AFile
+$       AFile = F$Search(File)
+$       If AFile .Eqs. "" .Or. AFile .Eqs. OFile Then Goto NextEl
+$       If F$CvTime(F$File(AFile,"RDT")) .Ges. Time Then Goto Makeit
+$       Goto Loop3
+$NextEL:
+$       El = El + 1
+$       Goto Loop2
+$EndL:
+$ arg=arg+1
+$ If arg .Le. 8 Then Goto Loop
+$ Goto Exit
+$
+$Makeit:
+$ VV=F$VERIFY(0)
+$ write sys$output P2
+$ 'P2
+$ VV='F$Verify(VV)
+$Exit:
+$ If V Then Set Verify
+$ENDSUBROUTINE
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/readpng.c b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/readpng.c
new file mode 100644
index 0000000..27a2f11
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/readpng.c
@@ -0,0 +1,311 @@
+/*---------------------------------------------------------------------------
+   rpng - simple PNG display program                              readpng.c
+  ---------------------------------------------------------------------------
+      Copyright (c) 1998-2007 Greg Roelofs.  All rights reserved.
+      This software is provided "as is," without warranty of any kind,
+      express or implied.  In no event shall the author or contributors
+      be held liable for any damages arising in any way from the use of
+      this software.
+      The contents of this file are DUAL-LICENSED.  You may modify and/or
+      redistribute this software according to the terms of one of the
+      following two licenses (at your option):
+      LICENSE 1 ("BSD-like with advertising clause"):
+      Permission is granted to anyone to use this software for any purpose,
+      including commercial applications, and to alter it and redistribute
+      it freely, subject to the following restrictions:
+      1. Redistributions of source code must retain the above copyright
+         notice, disclaimer, and this list of conditions.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, disclaimer, and this list of conditions in the documenta-
+         tion and/or other materials provided with the distribution.
+      3. All advertising materials mentioning features or use of this
+         software must display the following acknowledgment:
+            This product includes software developed by Greg Roelofs
+            and contributors for the book, "PNG: The Definitive Guide,"
+            published by O'Reilly and Associates.
+      LICENSE 2 (GNU GPL v2 or later):
+      This program is free software; you can redistribute it and/or modify
+      it under the terms of the GNU General Public License as published by
+      the Free Software Foundation; either version 2 of the License, or
+      (at your option) any later version.
+      This program is distributed in the hope that it will be useful,
+      but WITHOUT ANY WARRANTY; without even the implied warranty of
+      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+      GNU General Public License for more details.
+      You should have received a copy of the GNU General Public License
+      along with this program; if not, write to the Free Software Foundation,
+      Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+  ---------------------------------------------------------------------------*/
+#include <stdio.h>
+#include <stdlib.h>
+#include "png.h"        /* libpng header; includes zlib.h */
+#include "readpng.h"    /* typedefs, common macros, public prototypes */
+/* future versions of libpng will provide this macro: */
+#ifndef png_jmpbuf
+#  define png_jmpbuf(png_ptr)   ((png_ptr)->jmpbuf)
+#endif
+static png_structp png_ptr = NULL;
+static png_infop info_ptr = NULL;
+png_uint_32  width, height;
+int  bit_depth, color_type;
+uch  *image_data = NULL;
+void readpng_version_info(void)
+{
+    fprintf(stderr, "   Compiled with libpng %s; using libpng %s.\n",
+      PNG_LIBPNG_VER_STRING, png_libpng_ver);
+    fprintf(stderr, "   Compiled with zlib %s; using zlib %s.\n",
+      ZLIB_VERSION, zlib_version);
+}
+/* return value = 0 for success, 1 for bad sig, 2 for bad IHDR, 4 for no mem */
+int readpng_init(FILE *infile, ulg *pWidth, ulg *pHeight)
+{
+    uch sig[8];
+    /* first do a quick check that the file really is a PNG image; could
+     * have used slightly more general png_sig_cmp() function instead */
+    fread(sig, 1, 8, infile);
+    if (png_sig_cmp(sig, 0, 8))
+        return 1;   /* bad signature */
+    /* could pass pointers to user-defined error handlers instead of NULLs: */
+    png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+    if (!png_ptr)
+        return 4;   /* out of memory */
+    info_ptr = png_create_info_struct(png_ptr);
+    if (!info_ptr) {
+        png_destroy_read_struct(&png_ptr, NULL, NULL);
+        return 4;   /* out of memory */
+    }
+    /* we could create a second info struct here (end_info), but it's only
+     * useful if we want to keep pre- and post-IDAT chunk info separated
+     * (mainly for PNG-aware image editors and converters) */
+    /* setjmp() must be called in every function that calls a PNG-reading
+     * libpng function */
+    if (setjmp(png_jmpbuf(png_ptr))) {
+        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+        return 2;
+    }
+    png_init_io(png_ptr, infile);
+    png_set_sig_bytes(png_ptr, 8);  /* we already read the 8 signature bytes */
+    png_read_info(png_ptr, info_ptr);  /* read all PNG info up to image data */
+    /* alternatively, could make separate calls to png_get_image_width(),
+     * etc., but want bit_depth and color_type for later [don't care about
+     * compression_type and filter_type => NULLs] */
+    png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type,
+      NULL, NULL, NULL);
+    *pWidth = width;
+    *pHeight = height;
+    /* OK, that's all we need for now; return happy */
+    return 0;
+}
+/* returns 0 if succeeds, 1 if fails due to no bKGD chunk, 2 if libpng error;
+ * scales values to 8-bit if necessary */
+int readpng_get_bgcolor(uch *red, uch *green, uch *blue)
+{
+    png_color_16p pBackground;
+    /* setjmp() must be called in every function that calls a PNG-reading
+     * libpng function */
+    if (setjmp(png_jmpbuf(png_ptr))) {
+        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+        return 2;
+    }
+    if (!png_get_valid(png_ptr, info_ptr, PNG_INFO_bKGD))
+        return 1;
+    /* it is not obvious from the libpng documentation, but this function
+     * takes a pointer to a pointer, and it always returns valid red, green
+     * and blue values, regardless of color_type: */
+    png_get_bKGD(png_ptr, info_ptr, &pBackground);
+    /* however, it always returns the raw bKGD data, regardless of any
+     * bit-depth transformations, so check depth and adjust if necessary */
+    if (bit_depth == 16) {
+        *red   = pBackground->red   >> 8;
+        *green = pBackground->green >> 8;
+        *blue  = pBackground->blue  >> 8;
+    } else if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8) {
+        if (bit_depth == 1)
+            *red = *green = *blue = pBackground->gray? 255 : 0;
+        else if (bit_depth == 2)
+            *red = *green = *blue = (255/3) * pBackground->gray;
+        else /* bit_depth == 4 */
+            *red = *green = *blue = (255/15) * pBackground->gray;
+    } else {
+        *red   = (uch)pBackground->red;
+        *green = (uch)pBackground->green;
+        *blue  = (uch)pBackground->blue;
+    }
+    return 0;
+}
+/* display_exponent == LUT_exponent * CRT_exponent */
+uch *readpng_get_image(double display_exponent, int *pChannels, ulg *pRowbytes)
+{
+    double  gamma;
+    png_uint_32  i, rowbytes;
+    png_bytepp  row_pointers = NULL;
+    /* setjmp() must be called in every function that calls a PNG-reading
+     * libpng function */
+    if (setjmp(png_jmpbuf(png_ptr))) {
+        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+        return NULL;
+    }
+    /* expand palette images to RGB, low-bit-depth grayscale images to 8 bits,
+     * transparency chunks to full alpha channel; strip 16-bit-per-sample
+     * images to 8 bits per sample; and convert grayscale to RGB[A] */
+    if (color_type == PNG_COLOR_TYPE_PALETTE)
+        png_set_expand(png_ptr);
+    if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8)
+        png_set_expand(png_ptr);
+    if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))
+        png_set_expand(png_ptr);
+#ifdef PNG_READ_16_TO_8_SUPPORTED
+    if (bit_depth == 16)
+#  ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+        png_set_scale_16(png_ptr);
+#  else
+        png_set_strip_16(png_ptr);
+#  endif
+#endif
+    if (color_type == PNG_COLOR_TYPE_GRAY ||
+        color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+        png_set_gray_to_rgb(png_ptr);
+    /* unlike the example in the libpng documentation, we have *no* idea where
+     * this file may have come from--so if it doesn't have a file gamma, don't
+     * do any correction ("do no harm") */
+    if (png_get_gAMA(png_ptr, info_ptr, &gamma))
+        png_set_gamma(png_ptr, display_exponent, gamma);
+    /* all transformations have been registered; now update info_ptr data,
+     * get rowbytes and channels, and allocate image memory */
+    png_read_update_info(png_ptr, info_ptr);
+    *pRowbytes = rowbytes = png_get_rowbytes(png_ptr, info_ptr);
+    *pChannels = (int)png_get_channels(png_ptr, info_ptr);
+    if ((image_data = (uch *)malloc(rowbytes*height)) == NULL) {
+        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+        return NULL;
+    }
+    if ((row_pointers = (png_bytepp)malloc(height*sizeof(png_bytep))) == NULL) {
+        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+        free(image_data);
+        image_data = NULL;
+        return NULL;
+    }
+    Trace((stderr, "readpng_get_image:  channels = %d, rowbytes = %ld, height = %ld\n",
+        *pChannels, rowbytes, height));
+    /* set the individual row_pointers to point at the correct offsets */
+    for (i = 0;  i < height;  ++i)
+        row_pointers[i] = image_data + i*rowbytes;
+    /* now we can go ahead and just read the whole image */
+    png_read_image(png_ptr, row_pointers);
+    /* and we're done!  (png_read_end() can be omitted if no processing of
+     * post-IDAT text/time/etc. is desired) */
+    free(row_pointers);
+    row_pointers = NULL;
+    png_read_end(png_ptr, NULL);
+    return image_data;
+}
+void readpng_cleanup(int free_image_data)
+{
+    if (free_image_data && image_data) {
+        free(image_data);
+        image_data = NULL;
+    }
+    if (png_ptr && info_ptr) {
+        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+        png_ptr = NULL;
+        info_ptr = NULL;
+    }
+}
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/readpng.h b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/readpng.h
new file mode 100644
index 0000000..ec6b483
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/readpng.h
@@ -0,0 +1,88 @@
+/*---------------------------------------------------------------------------
+   rpng - simple PNG display program                              readpng.h
+  ---------------------------------------------------------------------------
+      Copyright (c) 1998-2007 Greg Roelofs.  All rights reserved.
+      This software is provided "as is," without warranty of any kind,
+      express or implied.  In no event shall the author or contributors
+      be held liable for any damages arising in any way from the use of
+      this software.
+      The contents of this file are DUAL-LICENSED.  You may modify and/or
+      redistribute this software according to the terms of one of the
+      following two licenses (at your option):
+      LICENSE 1 ("BSD-like with advertising clause"):
+      Permission is granted to anyone to use this software for any purpose,
+      including commercial applications, and to alter it and redistribute
+      it freely, subject to the following restrictions:
+      1. Redistributions of source code must retain the above copyright
+         notice, disclaimer, and this list of conditions.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, disclaimer, and this list of conditions in the documenta-
+         tion and/or other materials provided with the distribution.
+      3. All advertising materials mentioning features or use of this
+         software must display the following acknowledgment:
+            This product includes software developed by Greg Roelofs
+            and contributors for the book, "PNG: The Definitive Guide,"
+            published by O'Reilly and Associates.
+      LICENSE 2 (GNU GPL v2 or later):
+      This program is free software; you can redistribute it and/or modify
+      it under the terms of the GNU General Public License as published by
+      the Free Software Foundation; either version 2 of the License, or
+      (at your option) any later version.
+      This program is distributed in the hope that it will be useful,
+      but WITHOUT ANY WARRANTY; without even the implied warranty of
+      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+      GNU General Public License for more details.
+      You should have received a copy of the GNU General Public License
+      along with this program; if not, write to the Free Software Foundation,
+      Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+  ---------------------------------------------------------------------------*/
+#ifndef TRUE
+#  define TRUE 1
+#  define FALSE 0
+#endif
+#ifndef MAX
+#  define MAX(a,b)  ((a) > (b)? (a) : (b))
+#  define MIN(a,b)  ((a) < (b)? (a) : (b))
+#endif
+#ifdef DEBUG
+#  define Trace(x)  {fprintf x ; fflush(stderr); fflush(stdout);}
+#else
+#  define Trace(x)  ;
+#endif
+typedef unsigned char   uch;
+typedef unsigned short  ush;
+typedef unsigned long   ulg;
+/* prototypes for public functions in readpng.c */
+void readpng_version_info(void);
+int readpng_init(FILE *infile, ulg *pWidth, ulg *pHeight);
+int readpng_get_bgcolor(uch *bg_red, uch *bg_green, uch *bg_blue);
+uch *readpng_get_image(double display_exponent, int *pChannels,
+                       ulg *pRowbytes);
+void readpng_cleanup(int free_image_data);
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/readpng2.c b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/readpng2.c
new file mode 100644
index 0000000..3bbd2ec
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/readpng2.c
@@ -0,0 +1,511 @@
+/*---------------------------------------------------------------------------
+   rpng2 - progressive-model PNG display program                 readpng2.c
+  ---------------------------------------------------------------------------
+      Copyright (c) 1998-2007 Greg Roelofs.  All rights reserved.
+      This software is provided "as is," without warranty of any kind,
+      express or implied.  In no event shall the author or contributors
+      be held liable for any damages arising in any way from the use of
+      this software.
+      The contents of this file are DUAL-LICENSED.  You may modify and/or
+      redistribute this software according to the terms of one of the
+      following two licenses (at your option):
+      LICENSE 1 ("BSD-like with advertising clause"):
+      Permission is granted to anyone to use this software for any purpose,
+      including commercial applications, and to alter it and redistribute
+      it freely, subject to the following restrictions:
+      1. Redistributions of source code must retain the above copyright
+         notice, disclaimer, and this list of conditions.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, disclaimer, and this list of conditions in the documenta-
+         tion and/or other materials provided with the distribution.
+      3. All advertising materials mentioning features or use of this
+         software must display the following acknowledgment:
+            This product includes software developed by Greg Roelofs
+            and contributors for the book, "PNG: The Definitive Guide,"
+            published by O'Reilly and Associates.
+      LICENSE 2 (GNU GPL v2 or later):
+      This program is free software; you can redistribute it and/or modify
+      it under the terms of the GNU General Public License as published by
+      the Free Software Foundation; either version 2 of the License, or
+      (at your option) any later version.
+      This program is distributed in the hope that it will be useful,
+      but WITHOUT ANY WARRANTY; without even the implied warranty of
+      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+      GNU General Public License for more details.
+      You should have received a copy of the GNU General Public License
+      along with this program; if not, write to the Free Software Foundation,
+      Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+  ---------------------------------------------------------------------------*/
+#include <stdlib.h>     /* for exit() prototype */
+#include <setjmp.h>
+#include <zlib.h>
+#include "png.h"        /* libpng header from the local directory */
+#include "readpng2.h"   /* typedefs, common macros, public prototypes */
+/* local prototypes */
+static void readpng2_info_callback(png_structp png_ptr, png_infop info_ptr);
+static void readpng2_row_callback(png_structp png_ptr, png_bytep new_row,
+                                 png_uint_32 row_num, int pass);
+static void readpng2_end_callback(png_structp png_ptr, png_infop info_ptr);
+static void readpng2_error_handler(png_structp png_ptr, png_const_charp msg);
+void readpng2_version_info(void)
+{
+    fprintf(stderr, "   Compiled with libpng %s; using libpng %s\n",
+      PNG_LIBPNG_VER_STRING, png_libpng_ver);
+    fprintf(stderr, "   and with zlib %s; using zlib %s.\n",
+      ZLIB_VERSION, zlib_version);
+}
+int readpng2_check_sig(uch *sig, int num)
+{
+    return !png_sig_cmp(sig, 0, num);
+}
+/* returns 0 for success, 2 for libpng problem, 4 for out of memory */
+int readpng2_init(mainprog_info *mainprog_ptr)
+{
+    png_structp  png_ptr;       /* note:  temporary variables! */
+    png_infop  info_ptr;
+    /* could also replace libpng warning-handler (final NULL), but no need: */
+    png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, mainprog_ptr,
+      readpng2_error_handler, NULL);
+    if (!png_ptr)
+        return 4;   /* out of memory */
+    info_ptr = png_create_info_struct(png_ptr);
+    if (!info_ptr) {
+        png_destroy_read_struct(&png_ptr, NULL, NULL);
+        return 4;   /* out of memory */
+    }
+    /* we could create a second info struct here (end_info), but it's only
+     * useful if we want to keep pre- and post-IDAT chunk info separated
+     * (mainly for PNG-aware image editors and converters) */
+    /* setjmp() must be called in every function that calls a PNG-reading
+     * libpng function, unless an alternate error handler was installed--
+     * but compatible error handlers must either use longjmp() themselves
+     * (as in this program) or exit immediately, so here we are: */
+    if (setjmp(mainprog_ptr->jmpbuf)) {
+        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+        return 2;
+    }
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+    /* prepare the reader to ignore all recognized chunks whose data won't be
+     * used, i.e., all chunks recognized by libpng except for IHDR, PLTE, IDAT,
+     * IEND, tRNS, bKGD, gAMA, and sRGB (small performance improvement) */
+    {
+        /* These byte strings were copied from png.h.  If a future libpng
+         * version recognizes more chunks, add them to this list.  If a
+         * future version of readpng2.c recognizes more chunks, delete them
+         * from this list. */
+        static /* const */ png_byte chunks_to_ignore[] = {
+             99,  72,  82,  77, '\0',  /* cHRM */
+            104,  73,  83,  84, '\0',  /* hIST */
+            105,  67,  67,  80, '\0',  /* iCCP */
+            105,  84,  88, 116, '\0',  /* iTXt */
+            111,  70,  70, 115, '\0',  /* oFFs */
+            112,  67,  65,  76, '\0',  /* pCAL */
+            112,  72,  89, 115, '\0',  /* pHYs */
+            115,  66,  73,  84, '\0',  /* sBIT */
+            115,  67,  65,  76, '\0',  /* sCAL */
+            115,  80,  76,  84, '\0',  /* sPLT */
+            115,  84,  69,  82, '\0',  /* sTER */
+            116,  69,  88, 116, '\0',  /* tEXt */
+            116,  73,  77,  69, '\0',  /* tIME */
+            122,  84,  88, 116, '\0'   /* zTXt */
+        };
+        png_set_keep_unknown_chunks(png_ptr, 1 /* PNG_HANDLE_CHUNK_NEVER */,
+          chunks_to_ignore, sizeof(chunks_to_ignore)/5);
+    }
+#endif /* PNG_HANDLE_AS_UNKNOWN_SUPPORTED */
+    /* instead of doing png_init_io() here, now we set up our callback
+     * functions for progressive decoding */
+    png_set_progressive_read_fn(png_ptr, mainprog_ptr,
+      readpng2_info_callback, readpng2_row_callback, readpng2_end_callback);
+    /* make sure we save our pointers for use in readpng2_decode_data() */
+    mainprog_ptr->png_ptr = png_ptr;
+    mainprog_ptr->info_ptr = info_ptr;
+    /* and that's all there is to initialization */
+    return 0;
+}
+/* returns 0 for success, 2 for libpng (longjmp) problem */
+int readpng2_decode_data(mainprog_info *mainprog_ptr, uch *rawbuf, ulg length)
+{
+    png_structp png_ptr = (png_structp)mainprog_ptr->png_ptr;
+    png_infop info_ptr = (png_infop)mainprog_ptr->info_ptr;
+    /* setjmp() must be called in every function that calls a PNG-reading
+     * libpng function */
+    if (setjmp(mainprog_ptr->jmpbuf)) {
+        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+        mainprog_ptr->png_ptr = NULL;
+        mainprog_ptr->info_ptr = NULL;
+        return 2;
+    }
+    /* hand off the next chunk of input data to libpng for decoding */
+    png_process_data(png_ptr, info_ptr, rawbuf, length);
+    return 0;
+}
+static void readpng2_info_callback(png_structp png_ptr, png_infop info_ptr)
+{
+    mainprog_info  *mainprog_ptr;
+    int  color_type, bit_depth;
+    png_uint_32 width, height;
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+    double  gamma;
+#else
+    png_fixed_point gamma;
+#endif
+    /* setjmp() doesn't make sense here, because we'd either have to exit(),
+     * longjmp() ourselves, or return control to libpng, which doesn't want
+     * to see us again.  By not doing anything here, libpng will instead jump
+     * to readpng2_decode_data(), which can return an error value to the main
+     * program. */
+    /* retrieve the pointer to our special-purpose struct, using the png_ptr
+     * that libpng passed back to us (i.e., not a global this time--there's
+     * no real difference for a single image, but for a multithreaded browser
+     * decoding several PNG images at the same time, one needs to avoid mixing
+     * up different images' structs) */
+    mainprog_ptr = png_get_progressive_ptr(png_ptr);
+    if (mainprog_ptr == NULL) {         /* we be hosed */
+        fprintf(stderr,
+          "readpng2 error:  main struct not recoverable in info_callback.\n");
+        fflush(stderr);
+        return;
+        /*
+         * Alternatively, we could call our error-handler just like libpng
+         * does, which would effectively terminate the program.  Since this
+         * can only happen if png_ptr gets redirected somewhere odd or the
+         * main PNG struct gets wiped, we're probably toast anyway.  (If
+         * png_ptr itself is NULL, we would not have been called.)
+         */
+    }
+    /* this is just like in the non-progressive case */
+    png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type,
+       NULL, NULL, NULL);
+    mainprog_ptr->width = (ulg)width;
+    mainprog_ptr->height = (ulg)height;
+    /* since we know we've read all of the PNG file's "header" (i.e., up
+     * to IDAT), we can check for a background color here */
+    if (mainprog_ptr->need_bgcolor &&
+        png_get_valid(png_ptr, info_ptr, PNG_INFO_bKGD))
+    {
+        png_color_16p pBackground;
+        /* it is not obvious from the libpng documentation, but this function
+         * takes a pointer to a pointer, and it always returns valid red,
+         * green and blue values, regardless of color_type: */
+        png_get_bKGD(png_ptr, info_ptr, &pBackground);
+        /* however, it always returns the raw bKGD data, regardless of any
+         * bit-depth transformations, so check depth and adjust if necessary */
+        if (bit_depth == 16) {
+            mainprog_ptr->bg_red   = pBackground->red   >> 8;
+            mainprog_ptr->bg_green = pBackground->green >> 8;
+            mainprog_ptr->bg_blue  = pBackground->blue  >> 8;
+        } else if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8) {
+            if (bit_depth == 1)
+                mainprog_ptr->bg_red = mainprog_ptr->bg_green =
+                  mainprog_ptr->bg_blue = pBackground->gray? 255 : 0;
+            else if (bit_depth == 2)
+                mainprog_ptr->bg_red = mainprog_ptr->bg_green =
+                  mainprog_ptr->bg_blue = (255/3) * pBackground->gray;
+            else /* bit_depth == 4 */
+                mainprog_ptr->bg_red = mainprog_ptr->bg_green =
+                  mainprog_ptr->bg_blue = (255/15) * pBackground->gray;
+        } else {
+            mainprog_ptr->bg_red   = (uch)pBackground->red;
+            mainprog_ptr->bg_green = (uch)pBackground->green;
+            mainprog_ptr->bg_blue  = (uch)pBackground->blue;
+        }
+    }
+    /* as before, let libpng expand palette images to RGB, low-bit-depth
+     * grayscale images to 8 bits, transparency chunks to full alpha channel;
+     * strip 16-bit-per-sample images to 8 bits per sample; and convert
+     * grayscale to RGB[A] */
+    if (color_type == PNG_COLOR_TYPE_PALETTE)
+        png_set_expand(png_ptr);
+    if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8)
+        png_set_expand(png_ptr);
+    if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))
+        png_set_expand(png_ptr);
+#ifdef PNG_READ_16_TO_8_SUPPORTED
+    if (bit_depth == 16)
+#  ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+        png_set_scale_16(png_ptr);
+#  else
+        png_set_strip_16(png_ptr);
+#  endif
+#endif
+    if (color_type == PNG_COLOR_TYPE_GRAY ||
+        color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+        png_set_gray_to_rgb(png_ptr);
+    /* Unlike the basic viewer, which was designed to operate on local files,
+     * this program is intended to simulate a web browser--even though we
+     * actually read from a local file, too.  But because we are pretending
+     * that most of the images originate on the Internet, we follow the recom-
+     * mendation of the sRGB proposal and treat unlabelled images (no gAMA
+     * chunk) as existing in the sRGB color space.  That is, we assume that
+     * such images have a file gamma of 0.45455, which corresponds to a PC-like
+     * display system.  This change in assumptions will have no effect on a
+     * PC-like system, but on a Mac, SGI, NeXT or other system with a non-
+     * identity lookup table, it will darken unlabelled images, which effec-
+     * tively favors images from PC-like systems over those originating on
+     * the local platform.  Note that mainprog_ptr->display_exponent is the
+     * "gamma" value for the entire display system, i.e., the product of
+     * LUT_exponent and CRT_exponent. */
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+    if (png_get_gAMA(png_ptr, info_ptr, &gamma))
+        png_set_gamma(png_ptr, mainprog_ptr->display_exponent, gamma);
+    else
+        png_set_gamma(png_ptr, mainprog_ptr->display_exponent, 0.45455);
+#else
+    if (png_get_gAMA_fixed(png_ptr, info_ptr, &gamma))
+        png_set_gamma_fixed(png_ptr,
+            (png_fixed_point)(100000*mainprog_ptr->display_exponent+.5), gamma);
+    else
+        png_set_gamma_fixed(png_ptr,
+            (png_fixed_point)(100000*mainprog_ptr->display_exponent+.5), 45455);
+#endif
+    /* we'll let libpng expand interlaced images, too */
+    mainprog_ptr->passes = png_set_interlace_handling(png_ptr);
+    /* all transformations have been registered; now update info_ptr data and
+     * then get rowbytes and channels */
+    png_read_update_info(png_ptr, info_ptr);
+    mainprog_ptr->rowbytes = (int)png_get_rowbytes(png_ptr, info_ptr);
+    mainprog_ptr->channels = png_get_channels(png_ptr, info_ptr);
+    /* Call the main program to allocate memory for the image buffer and
+     * initialize windows and whatnot.  (The old-style function-pointer
+     * invocation is used for compatibility with a few supposedly ANSI
+     * compilers that nevertheless barf on "fn_ptr()"-style syntax.) */
+    (*mainprog_ptr->mainprog_init)();
+    /* and that takes care of initialization */
+    return;
+}
+static void readpng2_row_callback(png_structp png_ptr, png_bytep new_row,
+                                  png_uint_32 row_num, int pass)
+{
+    mainprog_info  *mainprog_ptr;
+    /* first check whether the row differs from the previous pass; if not,
+     * nothing to combine or display */
+    if (!new_row)
+        return;
+    /* retrieve the pointer to our special-purpose struct so we can access
+     * the old rows and image-display callback function */
+    mainprog_ptr = png_get_progressive_ptr(png_ptr);
+    /* save the pass number for optional use by the front end */
+    mainprog_ptr->pass = pass;
+    /* have libpng either combine the new row data with the existing row data
+     * from previous passes (if interlaced) or else just copy the new row
+     * into the main program's image buffer */
+    png_progressive_combine_row(png_ptr, mainprog_ptr->row_pointers[row_num],
+      new_row);
+    /* finally, call the display routine in the main program with the number
+     * of the row we just updated */
+    (*mainprog_ptr->mainprog_display_row)(row_num);
+    /* and we're ready for more */
+    return;
+}
+static void readpng2_end_callback(png_structp png_ptr, png_infop info_ptr)
+{
+    mainprog_info  *mainprog_ptr;
+    /* retrieve the pointer to our special-purpose struct */
+    mainprog_ptr = png_get_progressive_ptr(png_ptr);
+    /* let the main program know that it should flush any buffered image
+     * data to the display now and set a "done" flag or whatever, but note
+     * that it SHOULD NOT DESTROY THE PNG STRUCTS YET--in other words, do
+     * NOT call readpng2_cleanup() either here or in the finish_display()
+     * routine; wait until control returns to the main program via
+     * readpng2_decode_data() */
+    (*mainprog_ptr->mainprog_finish_display)();
+    /* all done */
+    return;
+}
+void readpng2_cleanup(mainprog_info *mainprog_ptr)
+{
+    png_structp png_ptr = (png_structp)mainprog_ptr->png_ptr;
+    png_infop info_ptr = (png_infop)mainprog_ptr->info_ptr;
+    if (png_ptr && info_ptr)
+        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+    mainprog_ptr->png_ptr = NULL;
+    mainprog_ptr->info_ptr = NULL;
+}
+static void readpng2_error_handler(png_structp png_ptr, png_const_charp msg)
+{
+    mainprog_info  *mainprog_ptr;
+    /* This function, aside from the extra step of retrieving the "error
+     * pointer" (below) and the fact that it exists within the application
+     * rather than within libpng, is essentially identical to libpng's
+     * default error handler.  The second point is critical:  since both
+     * setjmp() and longjmp() are called from the same code, they are
+     * guaranteed to have compatible notions of how big a jmp_buf is,
+     * regardless of whether _BSD_SOURCE or anything else has (or has not)
+     * been defined. */
+    fprintf(stderr, "readpng2 libpng error: %s\n", msg);
+    fflush(stderr);
+    mainprog_ptr = png_get_error_ptr(png_ptr);
+    if (mainprog_ptr == NULL) {         /* we are completely hosed now */
+        fprintf(stderr,
+          "readpng2 severe error:  jmpbuf not recoverable; terminating.\n");
+        fflush(stderr);
+        exit(99);
+    }
+    /* Now we have our data structure we can use the information in it
+     * to return control to our own higher level code (all the points
+     * where 'setjmp' is called in this file.)  This will work with other
+     * error handling mechanisms as well - libpng always calls png_error
+     * when it can proceed no further, thus, so long as the error handler
+     * is intercepted, application code can do its own error recovery.
+     */
+    longjmp(mainprog_ptr->jmpbuf, 1);
+}
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/readpng2.h b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/readpng2.h
new file mode 100644
index 0000000..7a59263
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/readpng2.h
@@ -0,0 +1,116 @@
+/*---------------------------------------------------------------------------
+   rpng2 - progressive-model PNG display program                 readpng2.h
+  ---------------------------------------------------------------------------
+      Copyright (c) 1998-2008 Greg Roelofs.  All rights reserved.
+      This software is provided "as is," without warranty of any kind,
+      express or implied.  In no event shall the author or contributors
+      be held liable for any damages arising in any way from the use of
+      this software.
+      The contents of this file are DUAL-LICENSED.  You may modify and/or
+      redistribute this software according to the terms of one of the
+      following two licenses (at your option):
+      LICENSE 1 ("BSD-like with advertising clause"):
+      Permission is granted to anyone to use this software for any purpose,
+      including commercial applications, and to alter it and redistribute
+      it freely, subject to the following restrictions:
+      1. Redistributions of source code must retain the above copyright
+         notice, disclaimer, and this list of conditions.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, disclaimer, and this list of conditions in the documenta-
+         tion and/or other materials provided with the distribution.
+      3. All advertising materials mentioning features or use of this
+         software must display the following acknowledgment:
+            This product includes software developed by Greg Roelofs
+            and contributors for the book, "PNG: The Definitive Guide,"
+            published by O'Reilly and Associates.
+      LICENSE 2 (GNU GPL v2 or later):
+      This program is free software; you can redistribute it and/or modify
+      it under the terms of the GNU General Public License as published by
+      the Free Software Foundation; either version 2 of the License, or
+      (at your option) any later version.
+      This program is distributed in the hope that it will be useful,
+      but WITHOUT ANY WARRANTY; without even the implied warranty of
+      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+      GNU General Public License for more details.
+      You should have received a copy of the GNU General Public License
+      along with this program; if not, write to the Free Software Foundation,
+      Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+  ---------------------------------------------------------------------------*/
+#ifndef TRUE
+#  define TRUE 1
+#  define FALSE 0
+#endif
+#ifndef MAX
+#  define MAX(a,b)  ((a) > (b)? (a) : (b))
+#  define MIN(a,b)  ((a) < (b)? (a) : (b))
+#endif
+#ifdef DEBUG
+#  define Trace(x)  {fprintf x ; fflush(stderr); fflush(stdout);}
+#else
+#  define Trace(x)  ;
+#endif
+enum rpng2_states {
+    kPreInit = 0,
+    kWindowInit,
+    kDone
+};
+typedef unsigned char   uch;
+typedef unsigned short  ush;
+typedef unsigned long   ulg;
+typedef struct _mainprog_info {
+    double display_exponent;
+    ulg width;
+    ulg height;
+    void *png_ptr;
+    void *info_ptr;
+    void (*mainprog_init)(void);
+    void (*mainprog_display_row)(ulg row_num);
+    void (*mainprog_finish_display)(void);
+    uch *image_data;
+    uch **row_pointers;
+    jmp_buf jmpbuf;
+    int passes;              /* not used */
+    int pass;
+    int rowbytes;
+    int channels;
+    int need_bgcolor;
+    int state;
+    uch bg_red;
+    uch bg_green;
+    uch bg_blue;
+} mainprog_info;
+/* prototypes for public functions in readpng2.c */
+void readpng2_version_info(void);
+int readpng2_check_sig(uch *sig, int num);
+int readpng2_init(mainprog_info *mainprog_ptr);
+int readpng2_decode_data(mainprog_info *mainprog_ptr, uch *rawbuf, ulg length);
+void readpng2_cleanup(mainprog_info *mainprog_ptr);
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/readppm.c b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/readppm.c
new file mode 100644
index 0000000..1ba2092
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/readppm.c
@@ -0,0 +1,179 @@
+/*---------------------------------------------------------------------------
+   rpng - simple PNG display program                              readppm.c
+  ---------------------------------------------------------------------------
+   This is a special-purpose replacement for readpng.c that allows binary
+   PPM files to be used in place of PNG images.
+  ---------------------------------------------------------------------------
+      Copyright (c) 1998-2007 Greg Roelofs.  All rights reserved.
+      This software is provided "as is," without warranty of any kind,
+      express or implied.  In no event shall the author or contributors
+      be held liable for any damages arising in any way from the use of
+      this software.
+      The contents of this file are DUAL-LICENSED.  You may modify and/or
+      redistribute this software according to the terms of one of the
+      following two licenses (at your option):
+      LICENSE 1 ("BSD-like with advertising clause"):
+      Permission is granted to anyone to use this software for any purpose,
+      including commercial applications, and to alter it and redistribute
+      it freely, subject to the following restrictions:
+      1. Redistributions of source code must retain the above copyright
+         notice, disclaimer, and this list of conditions.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, disclaimer, and this list of conditions in the documenta-
+         tion and/or other materials provided with the distribution.
+      3. All advertising materials mentioning features or use of this
+         software must display the following acknowledgment:
+            This product includes software developed by Greg Roelofs
+            and contributors for the book, "PNG: The Definitive Guide,"
+            published by O'Reilly and Associates.
+      LICENSE 2 (GNU GPL v2 or later):
+      This program is free software; you can redistribute it and/or modify
+      it under the terms of the GNU General Public License as published by
+      the Free Software Foundation; either version 2 of the License, or
+      (at your option) any later version.
+      This program is distributed in the hope that it will be useful,
+      but WITHOUT ANY WARRANTY; without even the implied warranty of
+      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+      GNU General Public License for more details.
+      You should have received a copy of the GNU General Public License
+      along with this program; if not, write to the Free Software Foundation,
+      Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+  ---------------------------------------------------------------------------*/
+#include <stdio.h>
+#include <stdlib.h>
+#include "readpng.h"    /* typedefs, common macros, public prototypes */
+ulg  width, height;
+int  bit_depth, color_type, channels;
+uch  *image_data = NULL;
+FILE *saved_infile;
+void readpng_version_info()
+{
+    fprintf(stderr, "   Compiled without libpng, zlib or PBMPLUS/NetPBM.\n");
+}
+/* return value = 0 for success, 1 for bad sig, 2 for bad IHDR, 4 for no mem */
+int readpng_init(FILE *infile, ulg *pWidth, ulg *pHeight)
+{
+    static uch ppmline[256];
+    int maxval;
+    saved_infile = infile;
+    fgets(ppmline, 256, infile);
+    if (ppmline[0] != 'P' || ppmline[1] != '6') {
+        fprintf(stderr, "ERROR:  not a PPM file\n");
+        return 1;
+    }
+    /* possible color types:  P5 = grayscale (0), P6 = RGB (2), P8 = RGBA (6) */
+    if (ppmline[1] == '6') {
+        color_type = 2;
+        channels = 3;
+    } else if (ppmline[1] == '8') {
+        color_type = 6;
+        channels = 4;
+    } else /* if (ppmline[1] == '5') */ {
+        color_type = 0;
+        channels = 1;
+    }
+    do {
+        fgets(ppmline, 256, infile);
+    } while (ppmline[0] == '#');
+    sscanf(ppmline, "%lu %lu", &width, &height);
+    do {
+        fgets(ppmline, 256, infile);
+    } while (ppmline[0] == '#');
+    sscanf(ppmline, "%d", &maxval);
+    if (maxval != 255) {
+        fprintf(stderr, "ERROR:  maxval = %d\n", maxval);
+        return 2;
+    }
+    bit_depth = 8;
+    *pWidth = width;
+    *pHeight = height;
+    return 0;
+}
+/* returns 0 if succeeds, 1 if fails due to no bKGD chunk, 2 if libpng error;
+ * scales values to 8-bit if necessary */
+int readpng_get_bgcolor(uch *red, uch *green, uch *blue)
+{
+    return 1;
+}
+/* display_exponent == LUT_exponent * CRT_exponent */
+uch *readpng_get_image(double display_exponent, int *pChannels, ulg *pRowbytes)
+{
+    ulg  rowbytes;
+    /* expand palette images to RGB, low-bit-depth grayscale images to 8 bits,
+     * transparency chunks to full alpha channel; strip 16-bit-per-sample
+     * images to 8 bits per sample; and convert grayscale to RGB[A] */
+    /* GRR WARNING:  grayscale needs to be expanded and channels reset! */
+    *pRowbytes = rowbytes = channels*width;
+    *pChannels = channels;
+    if ((image_data = (uch *)malloc(rowbytes*height)) == NULL) {
+        return NULL;
+    }
+    Trace((stderr, "readpng_get_image:  rowbytes = %ld, height = %ld\n", rowbytes, height));
+    /* now we can go ahead and just read the whole image */
+    fread(image_data, 1L, rowbytes*height, saved_infile);
+    return image_data;
+}
+void readpng_cleanup(int free_image_data)
+{
+    if (free_image_data && image_data) {
+        free(image_data);
+        image_data = NULL;
+    }
+}
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/rpng-win.c b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/rpng-win.c
new file mode 100644
index 0000000..1c22282
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/rpng-win.c
@@ -0,0 +1,728 @@
+/*---------------------------------------------------------------------------
+   rpng - simple PNG display program                             rpng-win.c
+   This program decodes and displays PNG images, with gamma correction and
+   optionally with a user-specified background color (in case the image has
+   transparency).  It is very nearly the most basic PNG viewer possible.
+   This version is for 32-bit Windows; it may compile under 16-bit Windows
+   with a little tweaking (or maybe not).
+   to do:
+    - handle quoted command-line args (especially filenames with spaces)
+    - have minimum window width:  oh well
+    - use %.1023s to simplify truncation of title-bar string?
+  ---------------------------------------------------------------------------
+   Changelog:
+    - 1.00:  initial public release
+    - 1.01:  modified to allow abbreviated options; fixed long/ulong mis-
+              match; switched to png_jmpbuf() macro
+    - 1.02:  added extra set of parentheses to png_jmpbuf() macro; fixed
+              command-line parsing bug
+    - 1.10:  enabled "message window"/console (thanks to David Geldreich)
+    - 2.00:  dual-licensed (added GNU GPL)
+    - 2.01:  fixed improper display of usage screen on PNG error(s)
+  ---------------------------------------------------------------------------
+      Copyright (c) 1998-2008 Greg Roelofs.  All rights reserved.
+      This software is provided "as is," without warranty of any kind,
+      express or implied.  In no event shall the author or contributors
+      be held liable for any damages arising in any way from the use of
+      this software.
+      The contents of this file are DUAL-LICENSED.  You may modify and/or
+      redistribute this software according to the terms of one of the
+      following two licenses (at your option):
+      LICENSE 1 ("BSD-like with advertising clause"):
+      Permission is granted to anyone to use this software for any purpose,
+      including commercial applications, and to alter it and redistribute
+      it freely, subject to the following restrictions:
+      1. Redistributions of source code must retain the above copyright
+         notice, disclaimer, and this list of conditions.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, disclaimer, and this list of conditions in the documenta-
+         tion and/or other materials provided with the distribution.
+      3. All advertising materials mentioning features or use of this
+         software must display the following acknowledgment:
+            This product includes software developed by Greg Roelofs
+            and contributors for the book, "PNG: The Definitive Guide,"
+            published by O'Reilly and Associates.
+      LICENSE 2 (GNU GPL v2 or later):
+      This program is free software; you can redistribute it and/or modify
+      it under the terms of the GNU General Public License as published by
+      the Free Software Foundation; either version 2 of the License, or
+      (at your option) any later version.
+      This program is distributed in the hope that it will be useful,
+      but WITHOUT ANY WARRANTY; without even the implied warranty of
+      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+      GNU General Public License for more details.
+      You should have received a copy of the GNU General Public License
+      along with this program; if not, write to the Free Software Foundation,
+      Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+  ---------------------------------------------------------------------------*/
+#define PROGNAME  "rpng-win"
+#define LONGNAME  "Simple PNG Viewer for Windows"
+#define VERSION   "2.01 of 16 March 2008"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <windows.h>
+#ifdef __CYGWIN__
+/* getch replacement. Turns out, we don't really need this,
+ * but leave it here if we ever enable any of the uses of
+ * _getch in the main code
+ */
+#include <unistd.h>
+#include <termio.h>
+#include <sys/ioctl.h>
+int repl_getch( void )
+{
+  char ch;
+  int fd = fileno(stdin);
+  struct termio old_tty, new_tty;
+  ioctl(fd, TCGETA, &old_tty);
+  new_tty = old_tty;
+  new_tty.c_lflag &= ~(ICANON | ECHO | ISIG);
+  ioctl(fd, TCSETA, &new_tty);
+  fread(&ch, 1, sizeof(ch), stdin);
+  ioctl(fd, TCSETA, &old_tty);
+  return ch;
+}
+#define _getch repl_getch
+#else
+#include <conio.h>      /* only for _getch() */
+#endif
+/* #define DEBUG  :  this enables the Trace() macros */
+#include "readpng.h"    /* typedefs, common macros, readpng prototypes */
+/* could just include png.h, but this macro is the only thing we need
+ * (name and typedefs changed to local versions); note that side effects
+ * only happen with alpha (which could easily be avoided with
+ * "ush acopy = (alpha);") */
+#define alpha_composite(composite, fg, alpha, bg) {               \
+    ush temp = ((ush)(fg)*(ush)(alpha) +                          \
+                (ush)(bg)*(ush)(255 - (ush)(alpha)) + (ush)128);  \
+    (composite) = (uch)((temp + (temp >> 8)) >> 8);               \
+}
+/* local prototypes */
+static int        rpng_win_create_window(HINSTANCE hInst, int showmode);
+static int        rpng_win_display_image(void);
+static void       rpng_win_cleanup(void);
+LRESULT CALLBACK  rpng_win_wndproc(HWND, UINT, WPARAM, LPARAM);
+static char titlebar[1024];
+static char *progname = PROGNAME;
+static char *appname = LONGNAME;
+static char *filename;
+static FILE *infile;
+static char *bgstr;
+static uch bg_red=0, bg_green=0, bg_blue=0;
+static double display_exponent;
+static ulg image_width, image_height, image_rowbytes;
+static int image_channels;
+static uch *image_data;
+/* Windows-specific variables */
+static ulg wimage_rowbytes;
+static uch *dib;
+static uch *wimage_data;
+static BITMAPINFOHEADER *bmih;
+static HWND global_hwnd;
+int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrevInst, PSTR cmd, int showmode)
+{
+    char *args[1024];                 /* arbitrary limit, but should suffice */
+    char *p, *q, **argv = args;
+    int argc = 0;
+    int rc, alen, flen;
+    int error = 0;
+    int have_bg = FALSE;
+    double LUT_exponent;              /* just the lookup table */
+    double CRT_exponent = 2.2;        /* just the monitor */
+    double default_display_exponent;  /* whole display system */
+    MSG msg;
+    filename = (char *)NULL;
+#ifndef __CYGWIN__
+    /* First reenable console output, which normally goes to the bit bucket
+     * for windowed apps.  Closing the console window will terminate the
+     * app.  Thanks to David.Geldreich@realviz.com for supplying the magical
+     * incantation. */
+    AllocConsole();
+    freopen("CONOUT$", "a", stderr);
+    freopen("CONOUT$", "a", stdout);
+#endif
+    /* Next set the default value for our display-system exponent, i.e.,
+     * the product of the CRT exponent and the exponent corresponding to
+     * the frame-buffer's lookup table (LUT), if any.  This is not an
+     * exhaustive list of LUT values (e.g., OpenStep has a lot of weird
+     * ones), but it should cover 99% of the current possibilities.  And
+     * yes, these ifdefs are completely wasted in a Windows program... */
+#if defined(NeXT)
+    LUT_exponent = 1.0 / 2.2;
+    /*
+    if (some_next_function_that_returns_gamma(&next_gamma))
+        LUT_exponent = 1.0 / next_gamma;
+     */
+#elif defined(sgi)
+    LUT_exponent = 1.0 / 1.7;
+    /* there doesn't seem to be any documented function to get the
+     * "gamma" value, so we do it the hard way */
+    infile = fopen("/etc/config/system.glGammaVal", "r");
+    if (infile) {
+        double sgi_gamma;
+        fgets(tmpline, 80, infile);
+        fclose(infile);
+        sgi_gamma = atof(tmpline);
+        if (sgi_gamma > 0.0)
+            LUT_exponent = 1.0 / sgi_gamma;
+    }
+#elif defined(Macintosh)
+    LUT_exponent = 1.8 / 2.61;
+    /*
+    if (some_mac_function_that_returns_gamma(&mac_gamma))
+        LUT_exponent = mac_gamma / 2.61;
+     */
+#else
+    LUT_exponent = 1.0;   /* assume no LUT:  most PCs */
+#endif
+    /* the defaults above give 1.0, 1.3, 1.5 and 2.2, respectively: */
+    default_display_exponent = LUT_exponent * CRT_exponent;
+    /* If the user has set the SCREEN_GAMMA environment variable as suggested
+     * (somewhat imprecisely) in the libpng documentation, use that; otherwise
+     * use the default value we just calculated.  Either way, the user may
+     * override this via a command-line option. */
+    if ((p = getenv("SCREEN_GAMMA")) != NULL)
+        display_exponent = atof(p);
+    else
+        display_exponent = default_display_exponent;
+    /* Windows really hates command lines, so we have to set up our own argv.
+     * Note that we do NOT bother with quoted arguments here, so don't use
+     * filenames with spaces in 'em! */
+    argv[argc++] = PROGNAME;
+    p = cmd;
+    for (;;) {
+        if (*p == ' ')
+            while (*++p == ' ')
+                ;
+        /* now p points at the first non-space after some spaces */
+        if (*p == '\0')
+            break;    /* nothing after the spaces:  done */
+        argv[argc++] = q = p;
+        while (*q && *q != ' ')
+            ++q;
+        /* now q points at a space or the end of the string */
+        if (*q == '\0')
+            break;    /* last argv already terminated; quit */
+        *q = '\0';    /* change space to terminator */
+        p = q + 1;
+    }
+    argv[argc] = NULL;   /* terminate the argv array itself */
+    /* Now parse the command line for options and the PNG filename. */
+    while (*++argv && !error) {
+        if (!strncmp(*argv, "-gamma", 2)) {
+            if (!*++argv)
+                ++error;
+            else {
+                display_exponent = atof(*argv);
+                if (display_exponent <= 0.0)
+                    ++error;
+            }
+        } else if (!strncmp(*argv, "-bgcolor", 2)) {
+            if (!*++argv)
+                ++error;
+            else {
+                bgstr = *argv;
+                if (strlen(bgstr) != 7 || bgstr[0] != '#')
+                    ++error;
+                else
+                    have_bg = TRUE;
+            }
+        } else {
+            if (**argv != '-') {
+                filename = *argv;
+                if (argv[1])   /* shouldn't be any more args after filename */
+                    ++error;
+            } else
+                ++error;   /* not expecting any other options */
+        }
+    }
+    if (!filename)
+        ++error;
+    /* print usage screen if any errors up to this point */
+    if (error) {
+#ifndef __CYGWIN__
+        int ch;
+#endif
+        fprintf(stderr, "\n%s %s:  %s\n\n", PROGNAME, VERSION, appname);
+        readpng_version_info();
+        fprintf(stderr, "\n"
+          "Usage:  %s [-gamma exp] [-bgcolor bg] file.png\n"
+          "    exp \ttransfer-function exponent (``gamma'') of the display\n"
+          "\t\t  system in floating-point format (e.g., ``%.1f''); equal\n"
+          "\t\t  to the product of the lookup-table exponent (varies)\n"
+          "\t\t  and the CRT exponent (usually 2.2); must be positive\n"
+          "    bg  \tdesired background color in 7-character hex RGB format\n"
+          "\t\t  (e.g., ``#ff7700'' for orange:  same as HTML colors);\n"
+          "\t\t  used with transparent images\n"
+          "\nPress Q, Esc or mouse button 1 after image is displayed to quit.\n"
+#ifndef __CYGWIN__
+          "Press Q or Esc to quit this usage screen.\n"
+#endif
+          "\n", PROGNAME, default_display_exponent);
+#ifndef __CYGWIN__
+        do
+            ch = _getch();
+        while (ch != 'q' && ch != 'Q' && ch != 0x1B);
+#endif
+        exit(1);
+    }
+    if (!(infile = fopen(filename, "rb"))) {
+        fprintf(stderr, PROGNAME ":  can't open PNG file [%s]\n", filename);
+        ++error;
+    } else {
+        if ((rc = readpng_init(infile, &image_width, &image_height)) != 0) {
+            switch (rc) {
+                case 1:
+                    fprintf(stderr, PROGNAME
+                      ":  [%s] is not a PNG file: incorrect signature\n",
+                      filename);
+                    break;
+                case 2:
+                    fprintf(stderr, PROGNAME
+                      ":  [%s] has bad IHDR (libpng longjmp)\n", filename);
+                    break;
+                case 4:
+                    fprintf(stderr, PROGNAME ":  insufficient memory\n");
+                    break;
+                default:
+                    fprintf(stderr, PROGNAME
+                      ":  unknown readpng_init() error\n");
+                    break;
+            }
+            ++error;
+        }
+        if (error)
+            fclose(infile);
+    }
+    if (error) {
+#ifndef __CYGWIN__
+        int ch;
+#endif
+        fprintf(stderr, PROGNAME ":  aborting.\n");
+#ifndef __CYGWIN__
+        do
+            ch = _getch();
+        while (ch != 'q' && ch != 'Q' && ch != 0x1B);
+#endif
+        exit(2);
+    } else {
+        fprintf(stderr, "\n%s %s:  %s\n", PROGNAME, VERSION, appname);
+#ifndef __CYGWIN__
+        fprintf(stderr,
+          "\n   [console window:  closing this window will terminate %s]\n\n",
+          PROGNAME);
+#endif
+    }
+    /* set the title-bar string, but make sure buffer doesn't overflow */
+    alen = strlen(appname);
+    flen = strlen(filename);
+    if (alen + flen + 3 > 1023)
+        sprintf(titlebar, "%s:  ...%s", appname, filename+(alen+flen+6-1023));
+    else
+        sprintf(titlebar, "%s:  %s", appname, filename);
+    /* if the user didn't specify a background color on the command line,
+     * check for one in the PNG file--if not, the initialized values of 0
+     * (black) will be used */
+    if (have_bg) {
+        unsigned r, g, b;   /* this approach quiets compiler warnings */
+        sscanf(bgstr+1, "%2x%2x%2x", &r, &g, &b);
+        bg_red   = (uch)r;
+        bg_green = (uch)g;
+        bg_blue  = (uch)b;
+    } else if (readpng_get_bgcolor(&bg_red, &bg_green, &bg_blue) > 1) {
+        readpng_cleanup(TRUE);
+        fprintf(stderr, PROGNAME
+          ":  libpng error while checking for background color\n");
+        exit(2);
+    }
+    /* do the basic Windows initialization stuff, make the window and fill it
+     * with the background color */
+    if (rpng_win_create_window(hInst, showmode))
+        exit(2);
+    /* decode the image, all at once */
+    Trace((stderr, "calling readpng_get_image()\n"))
+    image_data = readpng_get_image(display_exponent, &image_channels,
+      &image_rowbytes);
+    Trace((stderr, "done with readpng_get_image()\n"))
+    /* done with PNG file, so clean up to minimize memory usage (but do NOT
+     * nuke image_data!) */
+    readpng_cleanup(FALSE);
+    fclose(infile);
+    if (!image_data) {
+        fprintf(stderr, PROGNAME ":  unable to decode PNG image\n");
+        exit(3);
+    }
+    /* display image (composite with background if requested) */
+    Trace((stderr, "calling rpng_win_display_image()\n"))
+    if (rpng_win_display_image()) {
+        free(image_data);
+        exit(4);
+    }
+    Trace((stderr, "done with rpng_win_display_image()\n"))
+    /* wait for the user to tell us when to quit */
+    printf(
+#ifndef __CYGWIN__
+      "Done.  Press Q, Esc or mouse button 1 (within image window) to quit.\n"
+#else
+      "Done.  Press mouse button 1 (within image window) to quit.\n"
+#endif
+    );
+    fflush(stdout);
+    while (GetMessage(&msg, NULL, 0, 0)) {
+        TranslateMessage(&msg);
+        DispatchMessage(&msg);
+    }
+    /* OK, we're done:  clean up all image and Windows resources and go away */
+    rpng_win_cleanup();
+    return msg.wParam;
+}
+static int rpng_win_create_window(HINSTANCE hInst, int showmode)
+{
+    uch *dest;
+    int extra_width, extra_height;
+    ulg i, j;
+    WNDCLASSEX wndclass;
+/*---------------------------------------------------------------------------
+    Allocate memory for the display-specific version of the image (round up
+    to multiple of 4 for Windows DIB).
+  ---------------------------------------------------------------------------*/
+    wimage_rowbytes = ((3*image_width + 3L) >> 2) << 2;
+    if (!(dib = (uch *)malloc(sizeof(BITMAPINFOHEADER) +
+                              wimage_rowbytes*image_height)))
+    {
+        return 4;   /* fail */
+    }
+/*---------------------------------------------------------------------------
+    Initialize the DIB.  Negative height means to use top-down BMP ordering
+    (must be uncompressed, but that's what we want).  Bit count of 1, 4 or 8
+    implies a colormap of RGBX quads, but 24-bit BMPs just use B,G,R values
+    directly => wimage_data begins immediately after BMP header.
+  ---------------------------------------------------------------------------*/
+    memset(dib, 0, sizeof(BITMAPINFOHEADER));
+    bmih = (BITMAPINFOHEADER *)dib;
+    bmih->biSize = sizeof(BITMAPINFOHEADER);
+    bmih->biWidth = image_width;
+    bmih->biHeight = -((long)image_height);
+    bmih->biPlanes = 1;
+    bmih->biBitCount = 24;
+    bmih->biCompression = 0;
+    wimage_data = dib + sizeof(BITMAPINFOHEADER);
+/*---------------------------------------------------------------------------
+    Fill in background color (black by default); data are in BGR order.
+  ---------------------------------------------------------------------------*/
+    for (j = 0;  j < image_height;  ++j) {
+        dest = wimage_data + j*wimage_rowbytes;
+        for (i = image_width;  i > 0;  --i) {
+            *dest++ = bg_blue;
+            *dest++ = bg_green;
+            *dest++ = bg_red;
+        }
+    }
+/*---------------------------------------------------------------------------
+    Set the window parameters.
+  ---------------------------------------------------------------------------*/
+    memset(&wndclass, 0, sizeof(wndclass));
+    wndclass.cbSize = sizeof(wndclass);
+    wndclass.style = CS_HREDRAW | CS_VREDRAW;
+    wndclass.lpfnWndProc = rpng_win_wndproc;
+    wndclass.hInstance = hInst;
+    wndclass.hIcon = LoadIcon(NULL, IDI_APPLICATION);
+    wndclass.hCursor = LoadCursor(NULL, IDC_ARROW);
+    wndclass.hbrBackground = (HBRUSH)GetStockObject(DKGRAY_BRUSH);
+    wndclass.lpszMenuName = NULL;
+    wndclass.lpszClassName = progname;
+    wndclass.hIconSm = LoadIcon(NULL, IDI_APPLICATION);
+    RegisterClassEx(&wndclass);
+/*---------------------------------------------------------------------------
+    Finally, create the window.
+  ---------------------------------------------------------------------------*/
+    extra_width  = 2*(GetSystemMetrics(SM_CXBORDER) +
+                      GetSystemMetrics(SM_CXDLGFRAME));
+    extra_height = 2*(GetSystemMetrics(SM_CYBORDER) +
+                      GetSystemMetrics(SM_CYDLGFRAME)) +
+                      GetSystemMetrics(SM_CYCAPTION);
+    global_hwnd = CreateWindow(progname, titlebar, WS_OVERLAPPEDWINDOW,
+      CW_USEDEFAULT, CW_USEDEFAULT, image_width+extra_width,
+      image_height+extra_height, NULL, NULL, hInst, NULL);
+    ShowWindow(global_hwnd, showmode);
+    UpdateWindow(global_hwnd);
+    return 0;
+} /* end function rpng_win_create_window() */
+static int rpng_win_display_image()
+{
+    uch *src, *dest;
+    uch r, g, b, a;
+    ulg i, row, lastrow;
+    RECT rect;
+    Trace((stderr, "beginning display loop (image_channels == %d)\n",
+      image_channels))
+    Trace((stderr, "(width = %ld, rowbytes = %ld, wimage_rowbytes = %d)\n",
+      image_width, image_rowbytes, wimage_rowbytes))
+/*---------------------------------------------------------------------------
+    Blast image data to buffer.  This whole routine takes place before the
+    message loop begins, so there's no real point in any pseudo-progressive
+    display...
+  ---------------------------------------------------------------------------*/
+    for (lastrow = row = 0;  row < image_height;  ++row) {
+        src = image_data + row*image_rowbytes;
+        dest = wimage_data + row*wimage_rowbytes;
+        if (image_channels == 3) {
+            for (i = image_width;  i > 0;  --i) {
+                r = *src++;
+                g = *src++;
+                b = *src++;
+                *dest++ = b;
+                *dest++ = g;   /* note reverse order */
+                *dest++ = r;
+            }
+        } else /* if (image_channels == 4) */ {
+            for (i = image_width;  i > 0;  --i) {
+                r = *src++;
+                g = *src++;
+                b = *src++;
+                a = *src++;
+                if (a == 255) {
+                    *dest++ = b;
+                    *dest++ = g;
+                    *dest++ = r;
+                } else if (a == 0) {
+                    *dest++ = bg_blue;
+                    *dest++ = bg_green;
+                    *dest++ = bg_red;
+                } else {
+                    /* this macro (copied from png.h) composites the
+                     * foreground and background values and puts the
+                     * result into the first argument; there are no
+                     * side effects with the first argument */
+                    alpha_composite(*dest++, b, a, bg_blue);
+                    alpha_composite(*dest++, g, a, bg_green);
+                    alpha_composite(*dest++, r, a, bg_red);
+                }
+            }
+        }
+        /* display after every 16 lines */
+        if (((row+1) & 0xf) == 0) {
+            rect.left = 0L;
+            rect.top = (LONG)lastrow;
+            rect.right = (LONG)image_width;      /* possibly off by one? */
+            rect.bottom = (LONG)lastrow + 16L;   /* possibly off by one? */
+            InvalidateRect(global_hwnd, &rect, FALSE);
+            UpdateWindow(global_hwnd);     /* similar to XFlush() */
+            lastrow = row + 1;
+        }
+    }
+    Trace((stderr, "calling final image-flush routine\n"))
+    if (lastrow < image_height) {
+        rect.left = 0L;
+        rect.top = (LONG)lastrow;
+        rect.right = (LONG)image_width;      /* possibly off by one? */
+        rect.bottom = (LONG)image_height;    /* possibly off by one? */
+        InvalidateRect(global_hwnd, &rect, FALSE);
+        UpdateWindow(global_hwnd);     /* similar to XFlush() */
+    }
+/*
+    last param determines whether or not background is wiped before paint
+    InvalidateRect(global_hwnd, NULL, TRUE);
+    UpdateWindow(global_hwnd);
+ */
+    return 0;
+}
+static void rpng_win_cleanup()
+{
+    if (image_data) {
+        free(image_data);
+        image_data = NULL;
+    }
+    if (dib) {
+        free(dib);
+        dib = NULL;
+    }
+}
+LRESULT CALLBACK rpng_win_wndproc(HWND hwnd, UINT iMsg, WPARAM wP, LPARAM lP)
+{
+    HDC         hdc;
+    PAINTSTRUCT ps;
+    int rc;
+    switch (iMsg) {
+        case WM_CREATE:
+            /* one-time processing here, if any */
+            return 0;
+        case WM_PAINT:
+            hdc = BeginPaint(hwnd, &ps);
+                    /*                    dest                          */
+            rc = StretchDIBits(hdc, 0, 0, image_width, image_height,
+                    /*                    source                        */
+                                    0, 0, image_width, image_height,
+                                    wimage_data, (BITMAPINFO *)bmih,
+                    /*              iUsage: no clue                     */
+                                    0, SRCCOPY);
+            EndPaint(hwnd, &ps);
+            return 0;
+        /* wait for the user to tell us when to quit */
+        case WM_CHAR:
+            switch (wP) {      /* only need one, so ignore repeat count */
+                case 'q':
+                case 'Q':
+                case 0x1B:     /* Esc key */
+                    PostQuitMessage(0);
+            }
+            return 0;
+        case WM_LBUTTONDOWN:   /* another way of quitting */
+        case WM_DESTROY:
+            PostQuitMessage(0);
+            return 0;
+    }
+    return DefWindowProc(hwnd, iMsg, wP, lP);
+}
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/rpng-x.c b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/rpng-x.c
new file mode 100644
index 0000000..fc8be88
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/rpng-x.c
@@ -0,0 +1,904 @@
+/*---------------------------------------------------------------------------
+   rpng - simple PNG display program                               rpng-x.c
+   This program decodes and displays PNG images, with gamma correction and
+   optionally with a user-specified background color (in case the image has
+   transparency).  It is very nearly the most basic PNG viewer possible.
+   This version is for the X Window System (tested by author under Unix and
+   by Martin Zinser under OpenVMS; may work under OS/2 with some tweaking).
+   to do:
+    - 8-bit (colormapped) X support
+    - use %.1023s to simplify truncation of title-bar string?
+  ---------------------------------------------------------------------------
+   Changelog:
+    - 1.01:  initial public release
+    - 1.02:  modified to allow abbreviated options; fixed long/ulong mis-
+              match; switched to png_jmpbuf() macro
+    - 1.10:  added support for non-default visuals; fixed X pixel-conversion
+    - 1.11:  added extra set of parentheses to png_jmpbuf() macro; fixed
+              command-line parsing bug
+    - 1.12:  fixed some small X memory leaks (thanks to Fran�ois Petitjean)
+    - 1.13:  fixed XFreeGC() crash bug (thanks to Patrick Welche)
+    - 1.14:  added support for X resources (thanks to Gerhard Niklasch)
+    - 2.00:  dual-licensed (added GNU GPL)
+    - 2.01:  fixed improper display of usage screen on PNG error(s)
+  ---------------------------------------------------------------------------
+      Copyright (c) 1998-2008 Greg Roelofs.  All rights reserved.
+      This software is provided "as is," without warranty of any kind,
+      express or implied.  In no event shall the author or contributors
+      be held liable for any damages arising in any way from the use of
+      this software.
+      The contents of this file are DUAL-LICENSED.  You may modify and/or
+      redistribute this software according to the terms of one of the
+      following two licenses (at your option):
+      LICENSE 1 ("BSD-like with advertising clause"):
+      Permission is granted to anyone to use this software for any purpose,
+      including commercial applications, and to alter it and redistribute
+      it freely, subject to the following restrictions:
+      1. Redistributions of source code must retain the above copyright
+         notice, disclaimer, and this list of conditions.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, disclaimer, and this list of conditions in the documenta-
+         tion and/or other materials provided with the distribution.
+      3. All advertising materials mentioning features or use of this
+         software must display the following acknowledgment:
+            This product includes software developed by Greg Roelofs
+            and contributors for the book, "PNG: The Definitive Guide,"
+            published by O'Reilly and Associates.
+      LICENSE 2 (GNU GPL v2 or later):
+      This program is free software; you can redistribute it and/or modify
+      it under the terms of the GNU General Public License as published by
+      the Free Software Foundation; either version 2 of the License, or
+      (at your option) any later version.
+      This program is distributed in the hope that it will be useful,
+      but WITHOUT ANY WARRANTY; without even the implied warranty of
+      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+      GNU General Public License for more details.
+      You should have received a copy of the GNU General Public License
+      along with this program; if not, write to the Free Software Foundation,
+      Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+  ---------------------------------------------------------------------------*/
+#define PROGNAME  "rpng-x"
+#define LONGNAME  "Simple PNG Viewer for X"
+#define VERSION   "2.01 of 16 March 2008"
+#define RESNAME   "rpng"        /* our X resource application name */
+#define RESCLASS  "Rpng"        /* our X resource class name */
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <X11/Xlib.h>
+#include <X11/Xutil.h>
+#include <X11/Xos.h>
+#include <X11/keysym.h>
+/* #define DEBUG  :  this enables the Trace() macros */
+#include "readpng.h"   /* typedefs, common macros, readpng prototypes */
+/* could just include png.h, but this macro is the only thing we need
+ * (name and typedefs changed to local versions); note that side effects
+ * only happen with alpha (which could easily be avoided with
+ * "ush acopy = (alpha);") */
+#define alpha_composite(composite, fg, alpha, bg) {               \
+    ush temp = ((ush)(fg)*(ush)(alpha) +                          \
+                (ush)(bg)*(ush)(255 - (ush)(alpha)) + (ush)128);  \
+    (composite) = (uch)((temp + (temp >> 8)) >> 8);               \
+}
+/* local prototypes */
+static int  rpng_x_create_window(void);
+static int  rpng_x_display_image(void);
+static void rpng_x_cleanup(void);
+static int  rpng_x_msb(ulg u32val);
+static char titlebar[1024], *window_name = titlebar;
+static char *appname = LONGNAME;
+static char *icon_name = PROGNAME;
+static char *res_name = RESNAME;
+static char *res_class = RESCLASS;
+static char *filename;
+static FILE *infile;
+static char *bgstr;
+static uch bg_red=0, bg_green=0, bg_blue=0;
+static double display_exponent;
+static ulg image_width, image_height, image_rowbytes;
+static int image_channels;
+static uch *image_data;
+/* X-specific variables */
+static char *displayname;
+static XImage *ximage;
+static Display *display;
+static int depth;
+static Visual *visual;
+static XVisualInfo *visual_list;
+static int RShift, GShift, BShift;
+static ulg RMask, GMask, BMask;
+static Window window;
+static GC gc;
+static Colormap colormap;
+static int have_nondefault_visual = FALSE;
+static int have_colormap = FALSE;
+static int have_window = FALSE;
+static int have_gc = FALSE;
+/*
+ulg numcolors=0, pixels[256];
+ush reds[256], greens[256], blues[256];
+ */
+int main(int argc, char **argv)
+{
+#ifdef sgi
+    char tmpline[80];
+#endif
+    char *p;
+    int rc, alen, flen;
+    int error = 0;
+    int have_bg = FALSE;
+    double LUT_exponent;               /* just the lookup table */
+    double CRT_exponent = 2.2;         /* just the monitor */
+    double default_display_exponent;   /* whole display system */
+    XEvent e;
+    KeySym k;
+    displayname = (char *)NULL;
+    filename = (char *)NULL;
+    /* First set the default value for our display-system exponent, i.e.,
+     * the product of the CRT exponent and the exponent corresponding to
+     * the frame-buffer's lookup table (LUT), if any.  This is not an
+     * exhaustive list of LUT values (e.g., OpenStep has a lot of weird
+     * ones), but it should cover 99% of the current possibilities. */
+#if defined(NeXT)
+    LUT_exponent = 1.0 / 2.2;
+    /*
+    if (some_next_function_that_returns_gamma(&next_gamma))
+        LUT_exponent = 1.0 / next_gamma;
+     */
+#elif defined(sgi)
+    LUT_exponent = 1.0 / 1.7;
+    /* there doesn't seem to be any documented function to get the
+     * "gamma" value, so we do it the hard way */
+    infile = fopen("/etc/config/system.glGammaVal", "r");
+    if (infile) {
+        double sgi_gamma;
+        fgets(tmpline, 80, infile);
+        fclose(infile);
+        sgi_gamma = atof(tmpline);
+        if (sgi_gamma > 0.0)
+            LUT_exponent = 1.0 / sgi_gamma;
+    }
+#elif defined(Macintosh)
+    LUT_exponent = 1.8 / 2.61;
+    /*
+    if (some_mac_function_that_returns_gamma(&mac_gamma))
+        LUT_exponent = mac_gamma / 2.61;
+     */
+#else
+    LUT_exponent = 1.0;   /* assume no LUT:  most PCs */
+#endif
+    /* the defaults above give 1.0, 1.3, 1.5 and 2.2, respectively: */
+    default_display_exponent = LUT_exponent * CRT_exponent;
+    /* If the user has set the SCREEN_GAMMA environment variable as suggested
+     * (somewhat imprecisely) in the libpng documentation, use that; otherwise
+     * use the default value we just calculated.  Either way, the user may
+     * override this via a command-line option. */
+    if ((p = getenv("SCREEN_GAMMA")) != NULL)
+        display_exponent = atof(p);
+    else
+        display_exponent = default_display_exponent;
+    /* Now parse the command line for options and the PNG filename. */
+    while (*++argv && !error) {
+        if (!strncmp(*argv, "-display", 2)) {
+            if (!*++argv)
+                ++error;
+            else
+                displayname = *argv;
+        } else if (!strncmp(*argv, "-gamma", 2)) {
+            if (!*++argv)
+                ++error;
+            else {
+                display_exponent = atof(*argv);
+                if (display_exponent <= 0.0)
+                    ++error;
+            }
+        } else if (!strncmp(*argv, "-bgcolor", 2)) {
+            if (!*++argv)
+                ++error;
+            else {
+                bgstr = *argv;
+                if (strlen(bgstr) != 7 || bgstr[0] != '#')
+                    ++error;
+                else
+                    have_bg = TRUE;
+            }
+        } else {
+            if (**argv != '-') {
+                filename = *argv;
+                if (argv[1])   /* shouldn't be any more args after filename */
+                    ++error;
+            } else
+                ++error;   /* not expecting any other options */
+        }
+    }
+    if (!filename)
+        ++error;
+    /* print usage screen if any errors up to this point */
+    if (error) {
+        fprintf(stderr, "\n%s %s:  %s\n", PROGNAME, VERSION, appname);
+        readpng_version_info();
+        fprintf(stderr, "\n"
+          "Usage:  %s [-display xdpy] [-gamma exp] [-bgcolor bg] file.png\n"
+          "    xdpy\tname of the target X display (e.g., ``hostname:0'')\n"
+          "    exp \ttransfer-function exponent (``gamma'') of the display\n"
+          "\t\t  system in floating-point format (e.g., ``%.1f''); equal\n"
+          "\t\t  to the product of the lookup-table exponent (varies)\n"
+          "\t\t  and the CRT exponent (usually 2.2); must be positive\n"
+          "    bg  \tdesired background color in 7-character hex RGB format\n"
+          "\t\t  (e.g., ``#ff7700'' for orange:  same as HTML colors);\n"
+          "\t\t  used with transparent images\n"
+          "\nPress Q, Esc or mouse button 1 (within image window, after image\n"
+          "is displayed) to quit.\n"
+          "\n", PROGNAME, default_display_exponent);
+        exit(1);
+    }
+    if (!(infile = fopen(filename, "rb"))) {
+        fprintf(stderr, PROGNAME ":  can't open PNG file [%s]\n", filename);
+        ++error;
+    } else {
+        if ((rc = readpng_init(infile, &image_width, &image_height)) != 0) {
+            switch (rc) {
+                case 1:
+                    fprintf(stderr, PROGNAME
+                      ":  [%s] is not a PNG file: incorrect signature\n",
+                      filename);
+                    break;
+                case 2:
+                    fprintf(stderr, PROGNAME
+                      ":  [%s] has bad IHDR (libpng longjmp)\n", filename);
+                    break;
+                case 4:
+                    fprintf(stderr, PROGNAME ":  insufficient memory\n");
+                    break;
+                default:
+                    fprintf(stderr, PROGNAME
+                      ":  unknown readpng_init() error\n");
+                    break;
+            }
+            ++error;
+        } else {
+            display = XOpenDisplay(displayname);
+            if (!display) {
+                readpng_cleanup(TRUE);
+                fprintf(stderr, PROGNAME ":  can't open X display [%s]\n",
+                  displayname? displayname : "default");
+                ++error;
+            }
+        }
+        if (error)
+            fclose(infile);
+    }
+    if (error) {
+        fprintf(stderr, PROGNAME ":  aborting.\n");
+        exit(2);
+    }
+    /* set the title-bar string, but make sure buffer doesn't overflow */
+    alen = strlen(appname);
+    flen = strlen(filename);
+    if (alen + flen + 3 > 1023)
+        sprintf(titlebar, "%s:  ...%s", appname, filename+(alen+flen+6-1023));
+    else
+        sprintf(titlebar, "%s:  %s", appname, filename);
+    /* if the user didn't specify a background color on the command line,
+     * check for one in the PNG file--if not, the initialized values of 0
+     * (black) will be used */
+    if (have_bg) {
+        unsigned r, g, b;   /* this approach quiets compiler warnings */
+        sscanf(bgstr+1, "%2x%2x%2x", &r, &g, &b);
+        bg_red   = (uch)r;
+        bg_green = (uch)g;
+        bg_blue  = (uch)b;
+    } else if (readpng_get_bgcolor(&bg_red, &bg_green, &bg_blue) > 1) {
+        readpng_cleanup(TRUE);
+        fprintf(stderr, PROGNAME
+          ":  libpng error while checking for background color\n");
+        exit(2);
+    }
+    /* do the basic X initialization stuff, make the window and fill it
+     * with the background color */
+    if (rpng_x_create_window())
+        exit(2);
+    /* decode the image, all at once */
+    Trace((stderr, "calling readpng_get_image()\n"))
+    image_data = readpng_get_image(display_exponent, &image_channels,
+      &image_rowbytes);
+    Trace((stderr, "done with readpng_get_image()\n"))
+    /* done with PNG file, so clean up to minimize memory usage (but do NOT
+     * nuke image_data!) */
+    readpng_cleanup(FALSE);
+    fclose(infile);
+    if (!image_data) {
+        fprintf(stderr, PROGNAME ":  unable to decode PNG image\n");
+        exit(3);
+    }
+    /* display image (composite with background if requested) */
+    Trace((stderr, "calling rpng_x_display_image()\n"))
+    if (rpng_x_display_image()) {
+        free(image_data);
+        exit(4);
+    }
+    Trace((stderr, "done with rpng_x_display_image()\n"))
+    /* wait for the user to tell us when to quit */
+    printf(
+      "Done.  Press Q, Esc or mouse button 1 (within image window) to quit.\n");
+    fflush(stdout);
+    do
+        XNextEvent(display, &e);
+    while (!(e.type == ButtonPress && e.xbutton.button == Button1) &&
+           !(e.type == KeyPress &&    /*  v--- or 1 for shifted keys */
+             ((k = XLookupKeysym(&e.xkey, 0)) == XK_q || k == XK_Escape) ));
+    /* OK, we're done:  clean up all image and X resources and go away */
+    rpng_x_cleanup();
+    return 0;
+}
+static int rpng_x_create_window(void)
+{
+    uch *xdata;
+    int need_colormap = FALSE;
+    int screen, pad;
+    ulg bg_pixel = 0L;
+    ulg attrmask;
+    Window root;
+    XEvent e;
+    XGCValues gcvalues;
+    XSetWindowAttributes attr;
+    XTextProperty windowName, *pWindowName = &windowName;
+    XTextProperty iconName, *pIconName = &iconName;
+    XVisualInfo visual_info;
+    XSizeHints *size_hints;
+    XWMHints *wm_hints;
+    XClassHint *class_hints;
+    screen = DefaultScreen(display);
+    depth = DisplayPlanes(display, screen);
+    root = RootWindow(display, screen);
+#ifdef DEBUG
+    XSynchronize(display, True);
+#endif
+#if 0
+/* GRR:  add 8-bit support */
+    if (/* depth != 8 && */ depth != 16 && depth != 24 && depth != 32) {
+        fprintf(stderr,
+          "screen depth %d not supported (only 16-, 24- or 32-bit TrueColor)\n",
+          depth);
+        return 2;
+    }
+    XMatchVisualInfo(display, screen, depth,
+      (depth == 8)? PseudoColor : TrueColor, &visual_info);
+    visual = visual_info.visual;
+#else
+    if (depth != 16 && depth != 24 && depth != 32) {
+        int visuals_matched = 0;
+        Trace((stderr, "default depth is %d:  checking other visuals\n",
+          depth))
+        /* 24-bit first */
+        visual_info.screen = screen;
+        visual_info.depth = 24;
+        visual_list = XGetVisualInfo(display,
+          VisualScreenMask | VisualDepthMask, &visual_info, &visuals_matched);
+        if (visuals_matched == 0) {
+/* GRR:  add 15-, 16- and 32-bit TrueColor visuals (also DirectColor?) */
+            fprintf(stderr, "default screen depth %d not supported, and no"
+              " 24-bit visuals found\n", depth);
+            return 2;
+        }
+        Trace((stderr, "XGetVisualInfo() returned %d 24-bit visuals\n",
+          visuals_matched))
+        visual = visual_list[0].visual;
+        depth = visual_list[0].depth;
+/*
+        colormap_size = visual_list[0].colormap_size;
+        visual_class = visual->class;
+        visualID = XVisualIDFromVisual(visual);
+ */
+        have_nondefault_visual = TRUE;
+        need_colormap = TRUE;
+    } else {
+        XMatchVisualInfo(display, screen, depth, TrueColor, &visual_info);
+        visual = visual_info.visual;
+    }
+#endif
+    RMask = visual->red_mask;
+    GMask = visual->green_mask;
+    BMask = visual->blue_mask;
+/* GRR:  add/check 8-bit support */
+    if (depth == 8 || need_colormap) {
+        colormap = XCreateColormap(display, root, visual, AllocNone);
+        if (!colormap) {
+            fprintf(stderr, "XCreateColormap() failed\n");
+            return 2;
+        }
+        have_colormap = TRUE;
+    }
+    if (depth == 15 || depth == 16) {
+        RShift = 15 - rpng_x_msb(RMask);    /* these are right-shifts */
+        GShift = 15 - rpng_x_msb(GMask);
+        BShift = 15 - rpng_x_msb(BMask);
+    } else if (depth > 16) {
+#define NO_24BIT_MASKS
+#ifdef NO_24BIT_MASKS
+        RShift = rpng_x_msb(RMask) - 7;     /* these are left-shifts */
+        GShift = rpng_x_msb(GMask) - 7;
+        BShift = rpng_x_msb(BMask) - 7;
+#else
+        RShift = 7 - rpng_x_msb(RMask);     /* these are right-shifts, too */
+        GShift = 7 - rpng_x_msb(GMask);
+        BShift = 7 - rpng_x_msb(BMask);
+#endif
+    }
+    if (depth >= 15 && (RShift < 0 || GShift < 0 || BShift < 0)) {
+        fprintf(stderr, "rpng internal logic error:  negative X shift(s)!\n");
+        return 2;
+    }
+/*---------------------------------------------------------------------------
+    Finally, create the window.
+  ---------------------------------------------------------------------------*/
+    attr.backing_store = Always;
+    attr.event_mask = ExposureMask | KeyPressMask | ButtonPressMask;
+    attrmask = CWBackingStore | CWEventMask;
+    if (have_nondefault_visual) {
+        attr.colormap = colormap;
+        attr.background_pixel = 0;
+        attr.border_pixel = 1;
+        attrmask |= CWColormap | CWBackPixel | CWBorderPixel;
+    }
+    window = XCreateWindow(display, root, 0, 0, image_width, image_height, 0,
+      depth, InputOutput, visual, attrmask, &attr);
+    if (window == None) {
+        fprintf(stderr, "XCreateWindow() failed\n");
+        return 2;
+    } else
+        have_window = TRUE;
+    if (depth == 8)
+        XSetWindowColormap(display, window, colormap);
+    if (!XStringListToTextProperty(&window_name, 1, pWindowName))
+        pWindowName = NULL;
+    if (!XStringListToTextProperty(&icon_name, 1, pIconName))
+        pIconName = NULL;
+    /* OK if any hints allocation fails; XSetWMProperties() allows NULLs */
+    if ((size_hints = XAllocSizeHints()) != NULL) {
+        /* window will not be resizable */
+        size_hints->flags = PMinSize | PMaxSize;
+        size_hints->min_width = size_hints->max_width = (int)image_width;
+        size_hints->min_height = size_hints->max_height = (int)image_height;
+    }
+    if ((wm_hints = XAllocWMHints()) != NULL) {
+        wm_hints->initial_state = NormalState;
+        wm_hints->input = True;
+     /* wm_hints->icon_pixmap = icon_pixmap; */
+        wm_hints->flags = StateHint | InputHint  /* | IconPixmapHint */ ;
+    }
+    if ((class_hints = XAllocClassHint()) != NULL) {
+        class_hints->res_name = res_name;
+        class_hints->res_class = res_class;
+    }
+    XSetWMProperties(display, window, pWindowName, pIconName, NULL, 0,
+      size_hints, wm_hints, class_hints);
+    /* various properties and hints no longer needed; free memory */
+    if (pWindowName)
+       XFree(pWindowName->value);
+    if (pIconName)
+       XFree(pIconName->value);
+    if (size_hints)
+        XFree(size_hints);
+    if (wm_hints)
+       XFree(wm_hints);
+    if (class_hints)
+       XFree(class_hints);
+    XMapWindow(display, window);
+    gc = XCreateGC(display, window, 0, &gcvalues);
+    have_gc = TRUE;
+/*---------------------------------------------------------------------------
+    Fill window with the specified background color.
+  ---------------------------------------------------------------------------*/
+    if (depth == 24 || depth == 32) {
+        bg_pixel = ((ulg)bg_red   << RShift) |
+                   ((ulg)bg_green << GShift) |
+                   ((ulg)bg_blue  << BShift);
+    } else if (depth == 16) {
+        bg_pixel = ((((ulg)bg_red   << 8) >> RShift) & RMask) |
+                   ((((ulg)bg_green << 8) >> GShift) & GMask) |
+                   ((((ulg)bg_blue  << 8) >> BShift) & BMask);
+    } else /* depth == 8 */ {
+        /* GRR:  add 8-bit support */
+    }
+    XSetForeground(display, gc, bg_pixel);
+    XFillRectangle(display, window, gc, 0, 0, image_width, image_height);
+/*---------------------------------------------------------------------------
+    Wait for first Expose event to do any drawing, then flush.
+  ---------------------------------------------------------------------------*/
+    do
+        XNextEvent(display, &e);
+    while (e.type != Expose || e.xexpose.count);
+    XFlush(display);
+/*---------------------------------------------------------------------------
+    Allocate memory for the X- and display-specific version of the image.
+  ---------------------------------------------------------------------------*/
+    if (depth == 24 || depth == 32) {
+        xdata = (uch *)malloc(4*image_width*image_height);
+        pad = 32;
+    } else if (depth == 16) {
+        xdata = (uch *)malloc(2*image_width*image_height);
+        pad = 16;
+    } else /* depth == 8 */ {
+        xdata = (uch *)malloc(image_width*image_height);
+        pad = 8;
+    }
+    if (!xdata) {
+        fprintf(stderr, PROGNAME ":  unable to allocate image memory\n");
+        return 4;
+    }
+    ximage = XCreateImage(display, visual, depth, ZPixmap, 0,
+      (char *)xdata, image_width, image_height, pad, 0);
+    if (!ximage) {
+        fprintf(stderr, PROGNAME ":  XCreateImage() failed\n");
+        free(xdata);
+        return 3;
+    }
+    /* to avoid testing the byte order every pixel (or doubling the size of
+     * the drawing routine with a giant if-test), we arbitrarily set the byte
+     * order to MSBFirst and let Xlib worry about inverting things on little-
+     * endian machines (like Linux/x86, old VAXen, etc.)--this is not the most
+     * efficient approach (the giant if-test would be better), but in the
+     * interest of clarity, we take the easy way out... */
+    ximage->byte_order = MSBFirst;
+    return 0;
+} /* end function rpng_x_create_window() */
+static int rpng_x_display_image(void)
+{
+    uch *src;
+    char *dest;
+    uch r, g, b, a;
+    ulg i, row, lastrow = 0;
+    ulg pixel;
+    int ximage_rowbytes = ximage->bytes_per_line;
+/*  int bpp = ximage->bits_per_pixel;  */
+    Trace((stderr, "beginning display loop (image_channels == %d)\n",
+      image_channels))
+    Trace((stderr, "   (width = %ld, rowbytes = %ld, ximage_rowbytes = %d)\n",
+      image_width, image_rowbytes, ximage_rowbytes))
+    Trace((stderr, "   (bpp = %d)\n", ximage->bits_per_pixel))
+    Trace((stderr, "   (byte_order = %s)\n", ximage->byte_order == MSBFirst?
+      "MSBFirst" : (ximage->byte_order == LSBFirst? "LSBFirst" : "unknown")))
+    if (depth == 24 || depth == 32) {
+        ulg red, green, blue;
+        for (lastrow = row = 0;  row < image_height;  ++row) {
+            src = image_data + row*image_rowbytes;
+            dest = ximage->data + row*ximage_rowbytes;
+            if (image_channels == 3) {
+                for (i = image_width;  i > 0;  --i) {
+                    red   = *src++;
+                    green = *src++;
+                    blue  = *src++;
+#ifdef NO_24BIT_MASKS
+                    pixel = (red   << RShift) |
+                            (green << GShift) |
+                            (blue  << BShift);
+                    /* recall that we set ximage->byte_order = MSBFirst above */
+                    /* GRR BUG:  this assumes bpp == 32, but may be 24: */
+                    *dest++ = (char)((pixel >> 24) & 0xff);
+                    *dest++ = (char)((pixel >> 16) & 0xff);
+                    *dest++ = (char)((pixel >>  8) & 0xff);
+                    *dest++ = (char)( pixel        & 0xff);
+#else
+                    red   = (RShift < 0)? red   << (-RShift) : red   >> RShift;
+                    green = (GShift < 0)? green << (-GShift) : green >> GShift;
+                    blue  = (BShift < 0)? blue  << (-BShift) : blue  >> BShift;
+                    pixel = (red & RMask) | (green & GMask) | (blue & BMask);
+                    /* recall that we set ximage->byte_order = MSBFirst above */
+                    *dest++ = (char)((pixel >> 24) & 0xff);
+                    *dest++ = (char)((pixel >> 16) & 0xff);
+                    *dest++ = (char)((pixel >>  8) & 0xff);
+                    *dest++ = (char)( pixel        & 0xff);
+#endif
+                }
+            } else /* if (image_channels == 4) */ {
+                for (i = image_width;  i > 0;  --i) {
+                    r = *src++;
+                    g = *src++;
+                    b = *src++;
+                    a = *src++;
+                    if (a == 255) {
+                        red   = r;
+                        green = g;
+                        blue  = b;
+                    } else if (a == 0) {
+                        red   = bg_red;
+                        green = bg_green;
+                        blue  = bg_blue;
+                    } else {
+                        /* this macro (from png.h) composites the foreground
+                         * and background values and puts the result into the
+                         * first argument */
+                        alpha_composite(red,   r, a, bg_red);
+                        alpha_composite(green, g, a, bg_green);
+                        alpha_composite(blue,  b, a, bg_blue);
+                    }
+                    pixel = (red   << RShift) |
+                            (green << GShift) |
+                            (blue  << BShift);
+                    /* recall that we set ximage->byte_order = MSBFirst above */
+                    *dest++ = (char)((pixel >> 24) & 0xff);
+                    *dest++ = (char)((pixel >> 16) & 0xff);
+                    *dest++ = (char)((pixel >>  8) & 0xff);
+                    *dest++ = (char)( pixel        & 0xff);
+                }
+            }
+            /* display after every 16 lines */
+            if (((row+1) & 0xf) == 0) {
+                XPutImage(display, window, gc, ximage, 0, (int)lastrow, 0,
+                  (int)lastrow, image_width, 16);
+                XFlush(display);
+                lastrow = row + 1;
+            }
+        }
+    } else if (depth == 16) {
+        ush red, green, blue;
+        for (lastrow = row = 0;  row < image_height;  ++row) {
+            src = image_data + row*image_rowbytes;
+            dest = ximage->data + row*ximage_rowbytes;
+            if (image_channels == 3) {
+                for (i = image_width;  i > 0;  --i) {
+                    red   = ((ush)(*src) << 8);
+                    ++src;
+                    green = ((ush)(*src) << 8);
+                    ++src;
+                    blue  = ((ush)(*src) << 8);
+                    ++src;
+                    pixel = ((red   >> RShift) & RMask) |
+                            ((green >> GShift) & GMask) |
+                            ((blue  >> BShift) & BMask);
+                    /* recall that we set ximage->byte_order = MSBFirst above */
+                    *dest++ = (char)((pixel >>  8) & 0xff);
+                    *dest++ = (char)( pixel        & 0xff);
+                }
+            } else /* if (image_channels == 4) */ {
+                for (i = image_width;  i > 0;  --i) {
+                    r = *src++;
+                    g = *src++;
+                    b = *src++;
+                    a = *src++;
+                    if (a == 255) {
+                        red   = ((ush)r << 8);
+                        green = ((ush)g << 8);
+                        blue  = ((ush)b << 8);
+                    } else if (a == 0) {
+                        red   = ((ush)bg_red   << 8);
+                        green = ((ush)bg_green << 8);
+                        blue  = ((ush)bg_blue  << 8);
+                    } else {
+                        /* this macro (from png.h) composites the foreground
+                         * and background values and puts the result back into
+                         * the first argument (== fg byte here:  safe) */
+                        alpha_composite(r, r, a, bg_red);
+                        alpha_composite(g, g, a, bg_green);
+                        alpha_composite(b, b, a, bg_blue);
+                        red   = ((ush)r << 8);
+                        green = ((ush)g << 8);
+                        blue  = ((ush)b << 8);
+                    }
+                    pixel = ((red   >> RShift) & RMask) |
+                            ((green >> GShift) & GMask) |
+                            ((blue  >> BShift) & BMask);
+                    /* recall that we set ximage->byte_order = MSBFirst above */
+                    *dest++ = (char)((pixel >>  8) & 0xff);
+                    *dest++ = (char)( pixel        & 0xff);
+                }
+            }
+            /* display after every 16 lines */
+            if (((row+1) & 0xf) == 0) {
+                XPutImage(display, window, gc, ximage, 0, (int)lastrow, 0,
+                  (int)lastrow, image_width, 16);
+                XFlush(display);
+                lastrow = row + 1;
+            }
+        }
+    } else /* depth == 8 */ {
+        /* GRR:  add 8-bit support */
+    }
+    Trace((stderr, "calling final XPutImage()\n"))
+    if (lastrow < image_height) {
+        XPutImage(display, window, gc, ximage, 0, (int)lastrow, 0,
+          (int)lastrow, image_width, image_height-lastrow);
+        XFlush(display);
+    }
+    return 0;
+}
+static void rpng_x_cleanup(void)
+{
+    if (image_data) {
+        free(image_data);
+        image_data = NULL;
+    }
+    if (ximage) {
+        if (ximage->data) {
+            free(ximage->data);           /* we allocated it, so we free it */
+            ximage->data = (char *)NULL;  /*  instead of XDestroyImage() */
+        }
+        XDestroyImage(ximage);
+        ximage = NULL;
+    }
+    if (have_gc)
+        XFreeGC(display, gc);
+    if (have_window)
+        XDestroyWindow(display, window);
+    if (have_colormap)
+        XFreeColormap(display, colormap);
+    if (have_nondefault_visual)
+        XFree(visual_list);
+}
+static int rpng_x_msb(ulg u32val)
+{
+    int i;
+    for (i = 31;  i >= 0;  --i) {
+        if (u32val & 0x80000000L)
+            break;
+        u32val <<= 1;
+    }
+    return i;
+}
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/rpng2-win.c b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/rpng2-win.c
new file mode 100644
index 0000000..2303b58
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/rpng2-win.c
@@ -0,0 +1,1253 @@
+/*---------------------------------------------------------------------------
+   rpng2 - progressive-model PNG display program                rpng2-win.c
+   This program decodes and displays PNG files progressively, as if it were
+   a web browser (though the front end is only set up to read from files).
+   It supports gamma correction, user-specified background colors, and user-
+   specified background patterns (for transparent images).  This version is
+   for 32-bit Windows; it may compile under 16-bit Windows with a little
+   tweaking (or maybe not).  Thanks to Adam Costello and Pieter S. van der
+   Meulen for the "diamond" and "radial waves" patterns, respectively.
+   to do (someday, maybe):
+    - handle quoted command-line args (especially filenames with spaces)
+    - finish resizable checkerboard-gradient (sizes 4-128?)
+    - use %.1023s to simplify truncation of title-bar string?
+    - have minimum window width:  oh well
+  ---------------------------------------------------------------------------
+   Changelog:
+    - 1.01:  initial public release
+    - 1.02:  fixed cut-and-paste error in usage screen (oops...)
+    - 1.03:  modified to allow abbreviated options
+    - 1.04:  removed bogus extra argument from usage fprintf() [Glenn R-P?];
+              fixed command-line parsing bug
+    - 1.10:  enabled "message window"/console (thanks to David Geldreich)
+    - 1.20:  added runtime MMX-enabling/disabling and new -mmx* options
+    - 1.21:  made minor tweak to usage screen to fit within 25-line console
+    - 1.22:  added AMD64/EM64T support (__x86_64__)
+    - 2.00:  dual-licensed (added GNU GPL)
+    - 2.01:  fixed 64-bit typo in readpng2.c
+    - 2.02:  fixed improper display of usage screen on PNG error(s); fixed
+              unexpected-EOF and file-read-error cases
+    - 2.03:  removed runtime MMX-enabling/disabling and obsolete -mmx* options
+  ---------------------------------------------------------------------------
+      Copyright (c) 1998-2008 Greg Roelofs.  All rights reserved.
+      This software is provided "as is," without warranty of any kind,
+      express or implied.  In no event shall the author or contributors
+      be held liable for any damages arising in any way from the use of
+      this software.
+      The contents of this file are DUAL-LICENSED.  You may modify and/or
+      redistribute this software according to the terms of one of the
+      following two licenses (at your option):
+      LICENSE 1 ("BSD-like with advertising clause"):
+      Permission is granted to anyone to use this software for any purpose,
+      including commercial applications, and to alter it and redistribute
+      it freely, subject to the following restrictions:
+      1. Redistributions of source code must retain the above copyright
+         notice, disclaimer, and this list of conditions.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, disclaimer, and this list of conditions in the documenta-
+         tion and/or other materials provided with the distribution.
+      3. All advertising materials mentioning features or use of this
+         software must display the following acknowledgment:
+            This product includes software developed by Greg Roelofs
+            and contributors for the book, "PNG: The Definitive Guide,"
+            published by O'Reilly and Associates.
+      LICENSE 2 (GNU GPL v2 or later):
+      This program is free software; you can redistribute it and/or modify
+      it under the terms of the GNU General Public License as published by
+      the Free Software Foundation; either version 2 of the License, or
+      (at your option) any later version.
+      This program is distributed in the hope that it will be useful,
+      but WITHOUT ANY WARRANTY; without even the implied warranty of
+      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+      GNU General Public License for more details.
+      You should have received a copy of the GNU General Public License
+      along with this program; if not, write to the Free Software Foundation,
+      Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+  ---------------------------------------------------------------------------*/
+#define PROGNAME  "rpng2-win"
+#define LONGNAME  "Progressive PNG Viewer for Windows"
+#define VERSION   "2.02 of 16 March 2008"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <setjmp.h>    /* for jmpbuf declaration in readpng2.h */
+#include <time.h>
+#include <math.h>      /* only for PvdM background code */
+#include <windows.h>
+#ifdef __CYGWIN__
+/* getch replacement. Turns out, we don't really need this,
+ * but leave it here if we ever enable any of the uses of
+ * _getch in the main code
+ */
+#include <unistd.h>
+#include <termio.h>
+#include <sys/ioctl.h>
+int repl_getch( void )
+{
+  char ch;
+  int fd = fileno(stdin);
+  struct termio old_tty, new_tty;
+  ioctl(fd, TCGETA, &old_tty);
+  new_tty = old_tty;
+  new_tty.c_lflag &= ~(ICANON | ECHO | ISIG);
+  ioctl(fd, TCSETA, &new_tty);
+  fread(&ch, 1, sizeof(ch), stdin);
+  ioctl(fd, TCSETA, &old_tty);
+  return ch;
+}
+#define _getch repl_getch
+#else
+#include <conio.h>     /* only for _getch() */
+#endif
+/* all for PvdM background code: */
+#ifndef PI
+#  define PI             3.141592653589793238
+#endif
+#define PI_2             (PI*0.5)
+#define INV_PI_360       (360.0 / PI)
+#define MAX(a,b)         (a>b?a:b)
+#define MIN(a,b)         (a<b?a:b)
+#define CLIP(a,min,max)  MAX(min,MIN((a),max))
+#define ABS(a)           ((a)<0?-(a):(a))
+#define CLIP8P(c)        MAX(0,(MIN((c),255)))   /* 8-bit pos. integer (uch) */
+#define ROUNDF(f)        ((int)(f + 0.5))
+#define rgb1_max   bg_freq
+#define rgb1_min   bg_gray
+#define rgb2_max   bg_bsat
+#define rgb2_min   bg_brot
+/* #define DEBUG */     /* this enables the Trace() macros */
+#include "readpng2.h"   /* typedefs, common macros, readpng2 prototypes */
+/* could just include png.h, but this macro is the only thing we need
+ * (name and typedefs changed to local versions); note that side effects
+ * only happen with alpha (which could easily be avoided with
+ * "ush acopy = (alpha);") */
+#define alpha_composite(composite, fg, alpha, bg) {               \
+    ush temp = ((ush)(fg)*(ush)(alpha) +                          \
+                (ush)(bg)*(ush)(255 - (ush)(alpha)) + (ush)128);  \
+    (composite) = (uch)((temp + (temp >> 8)) >> 8);               \
+}
+#define INBUFSIZE 4096   /* with pseudo-timing on (1 sec delay/block), this
+                          *  block size corresponds roughly to a download
+                          *  speed 10% faster than theoretical 33.6K maximum
+                          *  (assuming 8 data bits, 1 stop bit and no other
+                          *  overhead) */
+/* local prototypes */
+static void       rpng2_win_init(void);
+static int        rpng2_win_create_window(void);
+static int        rpng2_win_load_bg_image(void);
+static void       rpng2_win_display_row(ulg row);
+static void       rpng2_win_finish_display(void);
+static void       rpng2_win_cleanup(void);
+LRESULT CALLBACK  rpng2_win_wndproc(HWND, UINT, WPARAM, LPARAM);
+static char titlebar[1024];
+static char *progname = PROGNAME;
+static char *appname = LONGNAME;
+static char *filename;
+static FILE *infile;
+static mainprog_info rpng2_info;
+static uch inbuf[INBUFSIZE];
+static int incount;
+static int pat = 6;         /* must be less than num_bgpat */
+static int bg_image = 0;
+static int bgscale = 16;
+static ulg bg_rowbytes;
+static uch *bg_data;
+static struct rgb_color {
+    uch r, g, b;
+} rgb[] = {
+    {  0,   0,   0},    /*  0:  black */
+    {255, 255, 255},    /*  1:  white */
+    {173, 132,  57},    /*  2:  tan */
+    { 64, 132,   0},    /*  3:  medium green */
+    {189, 117,   1},    /*  4:  gold */
+    {253, 249,   1},    /*  5:  yellow */
+    {  0,   0, 255},    /*  6:  blue */
+    {  0,   0, 120},    /*  7:  medium blue */
+    {255,   0, 255},    /*  8:  magenta */
+    { 64,   0,  64},    /*  9:  dark magenta */
+    {255,   0,   0},    /* 10:  red */
+    { 64,   0,   0},    /* 11:  dark red */
+    {255, 127,   0},    /* 12:  orange */
+    {192,  96,   0},    /* 13:  darker orange */
+    { 24,  60,   0},    /* 14:  dark green-yellow */
+    { 85, 125, 200}     /* 15:  ice blue */
+};
+/* not used for now, but should be for error-checking:
+static int num_rgb = sizeof(rgb) / sizeof(struct rgb_color);
+ */
+/*
+    This whole struct is a fairly cheesy way to keep the number of
+    command-line options to a minimum.  The radial-waves background
+    type is a particularly poor fit to the integer elements of the
+    struct...but a few macros and a little fixed-point math will do
+    wonders for ya.
+    type bits:
+       F E D C B A 9 8 7 6 5 4 3 2 1 0
+                             | | | | |
+                             | | +-+-+-- 0 = sharp-edged checkerboard
+                             | |         1 = soft diamonds
+                             | |         2 = radial waves
+                             | |       3-7 = undefined
+                             | +-- gradient #2 inverted?
+                             +-- alternating columns inverted?
+ */
+static struct background_pattern {
+    ush type;
+    int rgb1_max, rgb1_min;     /* or bg_freq, bg_gray */
+    int rgb2_max, rgb2_min;     /* or bg_bsat, bg_brot (both scaled by 10)*/
+} bg[] = {
+    {0+8,   2,0,  1,15},        /* checkered:  tan/black vs. white/ice blue */
+    {0+24,  2,0,  1,0},         /* checkered:  tan/black vs. white/black */
+    {0+8,   4,5,  0,2},         /* checkered:  gold/yellow vs. black/tan */
+    {0+8,   4,5,  0,6},         /* checkered:  gold/yellow vs. black/blue */
+    {0,     7,0,  8,9},         /* checkered:  deep blue/black vs. magenta */
+    {0+8,  13,0,  5,14},        /* checkered:  orange/black vs. yellow */
+    {0+8,  12,0, 10,11},        /* checkered:  orange/black vs. red */
+    {1,     7,0,  8,0},         /* diamonds:  deep blue/black vs. magenta */
+    {1,    12,0, 11,0},         /* diamonds:  orange vs. dark red */
+    {1,    10,0,  7,0},         /* diamonds:  red vs. medium blue */
+    {1,     4,0,  5,0},         /* diamonds:  gold vs. yellow */
+    {1,     3,0,  0,0},         /* diamonds:  medium green vs. black */
+    {2,    16, 100,  20,   0},  /* radial:  ~hard radial color-beams */
+    {2,    18, 100,  10,   2},  /* radial:  soft, curved radial color-beams */
+    {2,    16, 256, 100, 250},  /* radial:  very tight spiral */
+    {2, 10000, 256,  11,   0}   /* radial:  dipole-moire' (almost fractal) */
+};
+static int num_bgpat = sizeof(bg) / sizeof(struct background_pattern);
+/* Windows-specific global variables (could go in struct, but messy...) */
+static ulg wimage_rowbytes;
+static uch *dib;
+static uch *wimage_data;
+static BITMAPINFOHEADER *bmih;
+static HWND global_hwnd;
+static HINSTANCE global_hInst;
+static int global_showmode;
+int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrevInst, PSTR cmd, int showmode)
+{
+    char *args[1024];                 /* arbitrary limit, but should suffice */
+    char **argv = args;
+    char *p, *q, *bgstr = NULL;
+    int argc = 0;
+    int rc, alen, flen;
+    int error = 0;
+    int timing = FALSE;
+    int have_bg = FALSE;
+    double LUT_exponent;              /* just the lookup table */
+    double CRT_exponent = 2.2;        /* just the monitor */
+    double default_display_exponent;  /* whole display system */
+    MSG msg;
+    /* First initialize a few things, just to be sure--memset takes care of
+     * default background color (black), booleans (FALSE), pointers (NULL),
+     * etc. */
+    global_hInst = hInst;
+    global_showmode = showmode;
+    filename = (char *)NULL;
+    memset(&rpng2_info, 0, sizeof(mainprog_info));
+#ifndef __CYGWIN__
+    /* Next reenable console output, which normally goes to the bit bucket
+     * for windowed apps.  Closing the console window will terminate the
+     * app.  Thanks to David.Geldreich@realviz.com for supplying the magical
+     * incantation. */
+    AllocConsole();
+    freopen("CONOUT$", "a", stderr);
+    freopen("CONOUT$", "a", stdout);
+#endif
+    /* Set the default value for our display-system exponent, i.e., the
+     * product of the CRT exponent and the exponent corresponding to
+     * the frame-buffer's lookup table (LUT), if any.  This is not an
+     * exhaustive list of LUT values (e.g., OpenStep has a lot of weird
+     * ones), but it should cover 99% of the current possibilities.  And
+     * yes, these ifdefs are completely wasted in a Windows program... */
+#if defined(NeXT)
+    /* third-party utilities can modify the default LUT exponent */
+    LUT_exponent = 1.0 / 2.2;
+    /*
+    if (some_next_function_that_returns_gamma(&next_gamma))
+        LUT_exponent = 1.0 / next_gamma;
+     */
+#elif defined(sgi)
+    LUT_exponent = 1.0 / 1.7;
+    /* there doesn't seem to be any documented function to
+     * get the "gamma" value, so we do it the hard way */
+    infile = fopen("/etc/config/system.glGammaVal", "r");
+    if (infile) {
+        double sgi_gamma;
+        fgets(tmpline, 80, infile);
+        fclose(infile);
+        sgi_gamma = atof(tmpline);
+        if (sgi_gamma > 0.0)
+            LUT_exponent = 1.0 / sgi_gamma;
+    }
+#elif defined(Macintosh)
+    LUT_exponent = 1.8 / 2.61;
+    /*
+    if (some_mac_function_that_returns_gamma(&mac_gamma))
+        LUT_exponent = mac_gamma / 2.61;
+     */
+#else
+    LUT_exponent = 1.0;   /* assume no LUT:  most PCs */
+#endif
+    /* the defaults above give 1.0, 1.3, 1.5 and 2.2, respectively: */
+    default_display_exponent = LUT_exponent * CRT_exponent;
+    /* If the user has set the SCREEN_GAMMA environment variable as suggested
+     * (somewhat imprecisely) in the libpng documentation, use that; otherwise
+     * use the default value we just calculated.  Either way, the user may
+     * override this via a command-line option. */
+    if ((p = getenv("SCREEN_GAMMA")) != NULL)
+        rpng2_info.display_exponent = atof(p);
+    else
+        rpng2_info.display_exponent = default_display_exponent;
+    /* Windows really hates command lines, so we have to set up our own argv.
+     * Note that we do NOT bother with quoted arguments here, so don't use
+     * filenames with spaces in 'em! */
+    argv[argc++] = PROGNAME;
+    p = cmd;
+    for (;;) {
+        if (*p == ' ')
+            while (*++p == ' ')
+                ;
+        /* now p points at the first non-space after some spaces */
+        if (*p == '\0')
+            break;    /* nothing after the spaces:  done */
+        argv[argc++] = q = p;
+        while (*q && *q != ' ')
+            ++q;
+        /* now q points at a space or the end of the string */
+        if (*q == '\0')
+            break;    /* last argv already terminated; quit */
+        *q = '\0';    /* change space to terminator */
+        p = q + 1;
+    }
+    argv[argc] = NULL;   /* terminate the argv array itself */
+    /* Now parse the command line for options and the PNG filename. */
+    while (*++argv && !error) {
+        if (!strncmp(*argv, "-gamma", 2)) {
+            if (!*++argv)
+                ++error;
+            else {
+                rpng2_info.display_exponent = atof(*argv);
+                if (rpng2_info.display_exponent <= 0.0)
+                    ++error;
+            }
+        } else if (!strncmp(*argv, "-bgcolor", 4)) {
+            if (!*++argv)
+                ++error;
+            else {
+                bgstr = *argv;
+                if (strlen(bgstr) != 7 || bgstr[0] != '#')
+                    ++error;
+                else {
+                    have_bg = TRUE;
+                    bg_image = FALSE;
+                }
+            }
+        } else if (!strncmp(*argv, "-bgpat", 4)) {
+            if (!*++argv)
+                ++error;
+            else {
+                pat = atoi(*argv) - 1;
+                if (pat < 0 || pat >= num_bgpat)
+                    ++error;
+                else {
+                    bg_image = TRUE;
+                    have_bg = FALSE;
+                }
+            }
+        } else if (!strncmp(*argv, "-timing", 2)) {
+            timing = TRUE;
+        } else {
+            if (**argv != '-') {
+                filename = *argv;
+                if (argv[1])   /* shouldn't be any more args after filename */
+                    ++error;
+            } else
+                ++error;   /* not expecting any other options */
+        }
+    }
+    if (!filename)
+        ++error;
+    /* print usage screen if any errors up to this point */
+    if (error) {
+#ifndef __CYGWIN__
+        int ch;
+#endif
+        fprintf(stderr, "\n%s %s:  %s\n\n", PROGNAME, VERSION, appname);
+        readpng2_version_info();
+        fprintf(stderr, "\n"
+          "Usage:  %s [-gamma exp] [-bgcolor bg | -bgpat pat] [-timing]\n"
+          "        %*s file.png\n\n"
+          "    exp \ttransfer-function exponent (``gamma'') of the display\n"
+          "\t\t  system in floating-point format (e.g., ``%.1f''); equal\n"
+          "\t\t  to the product of the lookup-table exponent (varies)\n"
+          "\t\t  and the CRT exponent (usually 2.2); must be positive\n"
+          "    bg  \tdesired background color in 7-character hex RGB format\n"
+          "\t\t  (e.g., ``#ff7700'' for orange:  same as HTML colors);\n"
+          "\t\t  used with transparent images; overrides -bgpat option\n"
+          "    pat \tdesired background pattern number (1-%d); used with\n"
+          "\t\t  transparent images; overrides -bgcolor option\n"
+          "    -timing\tenables delay for every block read, to simulate modem\n"
+          "\t\t  download of image (~36 Kbps)\n"
+          "\nPress Q, Esc or mouse button 1 after image is displayed to quit.\n"
+#ifndef __CYGWIN__
+          "Press Q or Esc to quit this usage screen. ",
+#else
+          ,
+#endif
+          PROGNAME,
+#if (defined(__i386__) || defined(_M_IX86) || defined(__x86_64__)) && \
+    !(defined(__CYGWIN__) || defined(__MINGW32__))
+          (int)strlen(PROGNAME), " ",
+#endif
+          (int)strlen(PROGNAME), " ", default_display_exponent, num_bgpat);
+        fflush(stderr);
+#ifndef __CYGWIN__
+        do
+            ch = _getch();
+        while (ch != 'q' && ch != 'Q' && ch != 0x1B);
+#endif
+        exit(1);
+    }
+    if (!(infile = fopen(filename, "rb"))) {
+        fprintf(stderr, PROGNAME ":  can't open PNG file [%s]\n", filename);
+        ++error;
+    } else {
+        incount = fread(inbuf, 1, INBUFSIZE, infile);
+        if (incount < 8 || !readpng2_check_sig(inbuf, 8)) {
+            fprintf(stderr, PROGNAME
+              ":  [%s] is not a PNG file: incorrect signature\n",
+              filename);
+            ++error;
+        } else if ((rc = readpng2_init(&rpng2_info)) != 0) {
+            switch (rc) {
+                case 2:
+                    fprintf(stderr, PROGNAME
+                      ":  [%s] has bad IHDR (libpng longjmp)\n", filename);
+                    break;
+                case 4:
+                    fprintf(stderr, PROGNAME ":  insufficient memory\n");
+                    break;
+                default:
+                    fprintf(stderr, PROGNAME
+                      ":  unknown readpng2_init() error\n");
+                    break;
+            }
+            ++error;
+        }
+        if (error)
+            fclose(infile);
+    }
+    if (error) {
+#ifndef __CYGWIN__
+        int ch;
+#endif
+        fprintf(stderr, PROGNAME ":  aborting.\n");
+#ifndef __CYGWIN__
+        do
+            ch = _getch();
+        while (ch != 'q' && ch != 'Q' && ch != 0x1B);
+#endif
+        exit(2);
+    } else {
+        fprintf(stderr, "\n%s %s:  %s\n", PROGNAME, VERSION, appname);
+#ifndef __CYGWIN__
+        fprintf(stderr,
+          "\n   [console window:  closing this window will terminate %s]\n\n",
+          PROGNAME);
+#endif
+        fflush(stderr);
+    }
+    /* set the title-bar string, but make sure buffer doesn't overflow */
+    alen = strlen(appname);
+    flen = strlen(filename);
+    if (alen + flen + 3 > 1023)
+        sprintf(titlebar, "%s:  ...%s", appname, filename+(alen+flen+6-1023));
+    else
+        sprintf(titlebar, "%s:  %s", appname, filename);
+    /* set some final rpng2_info variables before entering main data loop */
+    if (have_bg) {
+        unsigned r, g, b;   /* this approach quiets compiler warnings */
+        sscanf(bgstr+1, "%2x%2x%2x", &r, &g, &b);
+        rpng2_info.bg_red   = (uch)r;
+        rpng2_info.bg_green = (uch)g;
+        rpng2_info.bg_blue  = (uch)b;
+    } else
+        rpng2_info.need_bgcolor = TRUE;
+    rpng2_info.state = kPreInit;
+    rpng2_info.mainprog_init = rpng2_win_init;
+    rpng2_info.mainprog_display_row = rpng2_win_display_row;
+    rpng2_info.mainprog_finish_display = rpng2_win_finish_display;
+    /* OK, this is the fun part:  call readpng2_decode_data() at the start of
+     * the loop to deal with our first buffer of data (read in above to verify
+     * that the file is a PNG image), then loop through the file and continue
+     * calling the same routine to handle each chunk of data.  It in turn
+     * passes the data to libpng, which will invoke one or more of our call-
+     * backs as decoded data become available.  We optionally call Sleep() for
+     * one second per iteration to simulate downloading the image via an analog
+     * modem. */
+    for (;;) {
+        Trace((stderr, "about to call readpng2_decode_data()\n"))
+        if (readpng2_decode_data(&rpng2_info, inbuf, incount))
+            ++error;
+        Trace((stderr, "done with readpng2_decode_data()\n"))
+        if (error || incount != INBUFSIZE || rpng2_info.state == kDone) {
+            if (rpng2_info.state == kDone) {
+                Trace((stderr, "done decoding PNG image\n"))
+            } else if (ferror(infile)) {
+                fprintf(stderr, PROGNAME
+                  ":  error while reading PNG image file\n");
+                exit(3);
+            } else if (feof(infile)) {
+                fprintf(stderr, PROGNAME ":  end of file reached "
+                  "(unexpectedly) while reading PNG image file\n");
+                exit(3);
+            } else /* if (error) */ {
+                /* will print error message below */
+            }
+            break;
+        }
+        if (timing)
+            Sleep(1000L);
+        incount = fread(inbuf, 1, INBUFSIZE, infile);
+    }
+    /* clean up PNG stuff and report any decoding errors */
+    fclose(infile);
+    Trace((stderr, "about to call readpng2_cleanup()\n"))
+    readpng2_cleanup(&rpng2_info);
+    if (error) {
+        fprintf(stderr, PROGNAME ":  libpng error while decoding PNG image\n");
+        exit(3);
+    }
+    /* wait for the user to tell us when to quit */
+    while (GetMessage(&msg, NULL, 0, 0)) {
+        TranslateMessage(&msg);
+        DispatchMessage(&msg);
+    }
+    /* we're done:  clean up all image and Windows resources and go away */
+    Trace((stderr, "about to call rpng2_win_cleanup()\n"))
+    rpng2_win_cleanup();
+    return msg.wParam;
+}
+/* this function is called by readpng2_info_callback() in readpng2.c, which
+ * in turn is called by libpng after all of the pre-IDAT chunks have been
+ * read and processed--i.e., we now have enough info to finish initializing */
+static void rpng2_win_init()
+{
+    ulg i;
+    ulg rowbytes = rpng2_info.rowbytes;
+    Trace((stderr, "beginning rpng2_win_init()\n"))
+    Trace((stderr, "  rowbytes = %d\n", rpng2_info.rowbytes))
+    Trace((stderr, "  width  = %ld\n", rpng2_info.width))
+    Trace((stderr, "  height = %ld\n", rpng2_info.height))
+    rpng2_info.image_data = (uch *)malloc(rowbytes * rpng2_info.height);
+    if (!rpng2_info.image_data) {
+        readpng2_cleanup(&rpng2_info);
+        return;
+    }
+    rpng2_info.row_pointers = (uch **)malloc(rpng2_info.height * sizeof(uch *));
+    if (!rpng2_info.row_pointers) {
+        free(rpng2_info.image_data);
+        rpng2_info.image_data = NULL;
+        readpng2_cleanup(&rpng2_info);
+        return;
+    }
+    for (i = 0;  i < rpng2_info.height;  ++i)
+        rpng2_info.row_pointers[i] = rpng2_info.image_data + i*rowbytes;
+/*---------------------------------------------------------------------------
+    Do the basic Windows initialization stuff, make the window, and fill it
+    with the user-specified, file-specified or default background color.
+  ---------------------------------------------------------------------------*/
+    if (rpng2_win_create_window()) {
+        readpng2_cleanup(&rpng2_info);
+        return;
+    }
+    rpng2_info.state = kWindowInit;
+}
+static int rpng2_win_create_window()
+{
+    uch bg_red   = rpng2_info.bg_red;
+    uch bg_green = rpng2_info.bg_green;
+    uch bg_blue  = rpng2_info.bg_blue;
+    uch *dest;
+    int extra_width, extra_height;
+    ulg i, j;
+    WNDCLASSEX wndclass;
+    RECT rect;
+/*---------------------------------------------------------------------------
+    Allocate memory for the display-specific version of the image (round up
+    to multiple of 4 for Windows DIB).
+  ---------------------------------------------------------------------------*/
+    wimage_rowbytes = ((3*rpng2_info.width + 3L) >> 2) << 2;
+    if (!(dib = (uch *)malloc(sizeof(BITMAPINFOHEADER) +
+                              wimage_rowbytes*rpng2_info.height)))
+    {
+        return 4;   /* fail */
+    }
+/*---------------------------------------------------------------------------
+    Initialize the DIB.  Negative height means to use top-down BMP ordering
+    (must be uncompressed, but that's what we want).  Bit count of 1, 4 or 8
+    implies a colormap of RGBX quads, but 24-bit BMPs just use B,G,R values
+    directly => wimage_data begins immediately after BMP header.
+  ---------------------------------------------------------------------------*/
+    memset(dib, 0, sizeof(BITMAPINFOHEADER));
+    bmih = (BITMAPINFOHEADER *)dib;
+    bmih->biSize = sizeof(BITMAPINFOHEADER);
+    bmih->biWidth = rpng2_info.width;
+    bmih->biHeight = -((long)rpng2_info.height);
+    bmih->biPlanes = 1;
+    bmih->biBitCount = 24;
+    bmih->biCompression = 0;
+    wimage_data = dib + sizeof(BITMAPINFOHEADER);
+/*---------------------------------------------------------------------------
+    Fill window with the specified background color (default is black), but
+    defer loading faked "background image" until window is displayed (may be
+    slow to compute).  Data are in BGR order.
+  ---------------------------------------------------------------------------*/
+    if (bg_image) {   /* just fill with black for now */
+        memset(wimage_data, 0, wimage_rowbytes*rpng2_info.height);
+    } else {
+        for (j = 0;  j < rpng2_info.height;  ++j) {
+            dest = wimage_data + j*wimage_rowbytes;
+            for (i = rpng2_info.width;  i > 0;  --i) {
+                *dest++ = bg_blue;
+                *dest++ = bg_green;
+                *dest++ = bg_red;
+            }
+        }
+    }
+/*---------------------------------------------------------------------------
+    Set the window parameters.
+  ---------------------------------------------------------------------------*/
+    memset(&wndclass, 0, sizeof(wndclass));
+    wndclass.cbSize = sizeof(wndclass);
+    wndclass.style = CS_HREDRAW | CS_VREDRAW;
+    wndclass.lpfnWndProc = rpng2_win_wndproc;
+    wndclass.hInstance = global_hInst;
+    wndclass.hIcon = LoadIcon(NULL, IDI_APPLICATION);
+    wndclass.hCursor = LoadCursor(NULL, IDC_ARROW);
+    wndclass.hbrBackground = (HBRUSH)GetStockObject(DKGRAY_BRUSH);
+    wndclass.lpszMenuName = NULL;
+    wndclass.lpszClassName = progname;
+    wndclass.hIconSm = LoadIcon(NULL, IDI_APPLICATION);
+    RegisterClassEx(&wndclass);
+/*---------------------------------------------------------------------------
+    Finally, create the window.
+  ---------------------------------------------------------------------------*/
+    extra_width  = 2*(GetSystemMetrics(SM_CXBORDER) +
+                      GetSystemMetrics(SM_CXDLGFRAME));
+    extra_height = 2*(GetSystemMetrics(SM_CYBORDER) +
+                      GetSystemMetrics(SM_CYDLGFRAME)) +
+                      GetSystemMetrics(SM_CYCAPTION);
+    global_hwnd = CreateWindow(progname, titlebar, WS_OVERLAPPEDWINDOW,
+      CW_USEDEFAULT, CW_USEDEFAULT, rpng2_info.width+extra_width,
+      rpng2_info.height+extra_height, NULL, NULL, global_hInst, NULL);
+    ShowWindow(global_hwnd, global_showmode);
+    UpdateWindow(global_hwnd);
+/*---------------------------------------------------------------------------
+    Now compute the background image and display it.  If it fails (memory
+    allocation), revert to a plain background color.
+  ---------------------------------------------------------------------------*/
+    if (bg_image) {
+        static const char *msg = "Computing background image...";
+        int x, y, len = strlen(msg);
+        HDC hdc = GetDC(global_hwnd);
+        TEXTMETRIC tm;
+        GetTextMetrics(hdc, &tm);
+        x = (rpng2_info.width - len*tm.tmAveCharWidth)/2;
+        y = (rpng2_info.height - tm.tmHeight)/2;
+        SetBkMode(hdc, TRANSPARENT);
+        SetTextColor(hdc, GetSysColor(COLOR_HIGHLIGHTTEXT));
+        /* this can still begin out of bounds even if x is positive (???): */
+        TextOut(hdc, ((x < 0)? 0 : x), ((y < 0)? 0 : y), msg, len);
+        ReleaseDC(global_hwnd, hdc);
+        rpng2_win_load_bg_image();   /* resets bg_image if fails */
+    }
+    if (!bg_image) {
+        for (j = 0;  j < rpng2_info.height;  ++j) {
+            dest = wimage_data + j*wimage_rowbytes;
+            for (i = rpng2_info.width;  i > 0;  --i) {
+                *dest++ = bg_blue;
+                *dest++ = bg_green;
+                *dest++ = bg_red;
+            }
+        }
+    }
+    rect.left = 0L;
+    rect.top = 0L;
+    rect.right = (LONG)rpng2_info.width;       /* possibly off by one? */
+    rect.bottom = (LONG)rpng2_info.height;     /* possibly off by one? */
+    InvalidateRect(global_hwnd, &rect, FALSE);
+    UpdateWindow(global_hwnd);                 /* similar to XFlush() */
+    return 0;
+} /* end function rpng2_win_create_window() */
+static int rpng2_win_load_bg_image()
+{
+    uch *src, *dest;
+    uch r1, r2, g1, g2, b1, b2;
+    uch r1_inv, r2_inv, g1_inv, g2_inv, b1_inv, b2_inv;
+    int k, hmax, max;
+    int xidx, yidx, yidx_max = (bgscale-1);
+    int even_odd_vert, even_odd_horiz, even_odd;
+    int invert_gradient2 = (bg[pat].type & 0x08);
+    int invert_column;
+    ulg i, row;
+/*---------------------------------------------------------------------------
+    Allocate buffer for fake background image to be used with transparent
+    images; if this fails, revert to plain background color.
+  ---------------------------------------------------------------------------*/
+    bg_rowbytes = 3 * rpng2_info.width;
+    bg_data = (uch *)malloc(bg_rowbytes * rpng2_info.height);
+    if (!bg_data) {
+        fprintf(stderr, PROGNAME
+          ":  unable to allocate memory for background image\n");
+        bg_image = 0;
+        return 1;
+    }
+/*---------------------------------------------------------------------------
+    Vertical gradients (ramps) in NxN squares, alternating direction and
+    colors (N == bgscale).
+  ---------------------------------------------------------------------------*/
+    if ((bg[pat].type & 0x07) == 0) {
+        uch r1_min  = rgb[bg[pat].rgb1_min].r;
+        uch g1_min  = rgb[bg[pat].rgb1_min].g;
+        uch b1_min  = rgb[bg[pat].rgb1_min].b;
+        uch r2_min  = rgb[bg[pat].rgb2_min].r;
+        uch g2_min  = rgb[bg[pat].rgb2_min].g;
+        uch b2_min  = rgb[bg[pat].rgb2_min].b;
+        int r1_diff = rgb[bg[pat].rgb1_max].r - r1_min;
+        int g1_diff = rgb[bg[pat].rgb1_max].g - g1_min;
+        int b1_diff = rgb[bg[pat].rgb1_max].b - b1_min;
+        int r2_diff = rgb[bg[pat].rgb2_max].r - r2_min;
+        int g2_diff = rgb[bg[pat].rgb2_max].g - g2_min;
+        int b2_diff = rgb[bg[pat].rgb2_max].b - b2_min;
+        for (row = 0;  row < rpng2_info.height;  ++row) {
+            yidx = row % bgscale;
+            even_odd_vert = (row / bgscale) & 1;
+            r1 = r1_min + (r1_diff * yidx) / yidx_max;
+            g1 = g1_min + (g1_diff * yidx) / yidx_max;
+            b1 = b1_min + (b1_diff * yidx) / yidx_max;
+            r1_inv = r1_min + (r1_diff * (yidx_max-yidx)) / yidx_max;
+            g1_inv = g1_min + (g1_diff * (yidx_max-yidx)) / yidx_max;
+            b1_inv = b1_min + (b1_diff * (yidx_max-yidx)) / yidx_max;
+            r2 = r2_min + (r2_diff * yidx) / yidx_max;
+            g2 = g2_min + (g2_diff * yidx) / yidx_max;
+            b2 = b2_min + (b2_diff * yidx) / yidx_max;
+            r2_inv = r2_min + (r2_diff * (yidx_max-yidx)) / yidx_max;
+            g2_inv = g2_min + (g2_diff * (yidx_max-yidx)) / yidx_max;
+            b2_inv = b2_min + (b2_diff * (yidx_max-yidx)) / yidx_max;
+            dest = bg_data + row*bg_rowbytes;
+            for (i = 0;  i < rpng2_info.width;  ++i) {
+                even_odd_horiz = (i / bgscale) & 1;
+                even_odd = even_odd_vert ^ even_odd_horiz;
+                invert_column =
+                  (even_odd_horiz && (bg[pat].type & 0x10));
+                if (even_odd == 0) {         /* gradient #1 */
+                    if (invert_column) {
+                        *dest++ = r1_inv;
+                        *dest++ = g1_inv;
+                        *dest++ = b1_inv;
+                    } else {
+                        *dest++ = r1;
+                        *dest++ = g1;
+                        *dest++ = b1;
+                    }
+                } else {                     /* gradient #2 */
+                    if ((invert_column && invert_gradient2) ||
+                        (!invert_column && !invert_gradient2))
+                    {
+                        *dest++ = r2;        /* not inverted or */
+                        *dest++ = g2;        /*  doubly inverted */
+                        *dest++ = b2;
+                    } else {
+                        *dest++ = r2_inv;
+                        *dest++ = g2_inv;    /* singly inverted */
+                        *dest++ = b2_inv;
+                    }
+                }
+            }
+        }
+/*---------------------------------------------------------------------------
+    Soft gradient-diamonds with scale = bgscale.  Code contributed by Adam
+    M. Costello.
+  ---------------------------------------------------------------------------*/
+    } else if ((bg[pat].type & 0x07) == 1) {
+        hmax = (bgscale-1)/2;   /* half the max weight of a color */
+        max = 2*hmax;           /* the max weight of a color */
+        r1 = rgb[bg[pat].rgb1_max].r;
+        g1 = rgb[bg[pat].rgb1_max].g;
+        b1 = rgb[bg[pat].rgb1_max].b;
+        r2 = rgb[bg[pat].rgb2_max].r;
+        g2 = rgb[bg[pat].rgb2_max].g;
+        b2 = rgb[bg[pat].rgb2_max].b;
+        for (row = 0;  row < rpng2_info.height;  ++row) {
+            yidx = row % bgscale;
+            if (yidx > hmax)
+                yidx = bgscale-1 - yidx;
+            dest = bg_data + row*bg_rowbytes;
+            for (i = 0;  i < rpng2_info.width;  ++i) {
+                xidx = i % bgscale;
+                if (xidx > hmax)
+                    xidx = bgscale-1 - xidx;
+                k = xidx + yidx;
+                *dest++ = (k*r1 + (max-k)*r2) / max;
+                *dest++ = (k*g1 + (max-k)*g2) / max;
+                *dest++ = (k*b1 + (max-k)*b2) / max;
+            }
+        }
+/*---------------------------------------------------------------------------
+    Radial "starburst" with azimuthal sinusoids; [eventually number of sinu-
+    soids will equal bgscale?].  This one is slow but very cool.  Code con-
+    tributed by Pieter S. van der Meulen (originally in Smalltalk).
+  ---------------------------------------------------------------------------*/
+    } else if ((bg[pat].type & 0x07) == 2) {
+        uch ch;
+        int ii, x, y, hw, hh, grayspot;
+        double freq, rotate, saturate, gray, intensity;
+        double angle=0.0, aoffset=0.0, maxDist, dist;
+        double red=0.0, green=0.0, blue=0.0, hue, s, v, f, p, q, t;
+        fprintf(stderr, "%s:  computing radial background...",
+          PROGNAME);
+        fflush(stderr);
+        hh = rpng2_info.height / 2;
+        hw = rpng2_info.width / 2;
+        /* variables for radial waves:
+         *   aoffset:  number of degrees to rotate hue [CURRENTLY NOT USED]
+         *   freq:  number of color beams originating from the center
+         *   grayspot:  size of the graying center area (anti-alias)
+         *   rotate:  rotation of the beams as a function of radius
+         *   saturate:  saturation of beams' shape azimuthally
+         */
+        angle = CLIP(angle, 0.0, 360.0);
+        grayspot = CLIP(bg[pat].bg_gray, 1, (hh + hw));
+        freq = MAX((double)bg[pat].bg_freq, 0.0);
+        saturate = (double)bg[pat].bg_bsat * 0.1;
+        rotate = (double)bg[pat].bg_brot * 0.1;
+        gray = 0.0;
+        intensity = 0.0;
+        maxDist = (double)((hw*hw) + (hh*hh));
+        for (row = 0;  row < rpng2_info.height;  ++row) {
+            y = row - hh;
+            dest = bg_data + row*bg_rowbytes;
+            for (i = 0;  i < rpng2_info.width;  ++i) {
+                x = i - hw;
+                angle = (x == 0)? PI_2 : atan((double)y / (double)x);
+                gray = (double)MAX(ABS(y), ABS(x)) / grayspot;
+                gray = MIN(1.0, gray);
+                dist = (double)((x*x) + (y*y)) / maxDist;
+                intensity = cos((angle+(rotate*dist*PI)) * freq) *
+                  gray * saturate;
+                intensity = (MAX(MIN(intensity,1.0),-1.0) + 1.0) * 0.5;
+                hue = (angle + PI) * INV_PI_360 + aoffset;
+                s = gray * ((double)(ABS(x)+ABS(y)) / (double)(hw + hh));
+                s = MIN(MAX(s,0.0), 1.0);
+                v = MIN(MAX(intensity,0.0), 1.0);
+                if (s == 0.0) {
+                    ch = (uch)(v * 255.0);
+                    *dest++ = ch;
+                    *dest++ = ch;
+                    *dest++ = ch;
+                } else {
+                    if ((hue < 0.0) || (hue >= 360.0))
+                        hue -= (((int)(hue / 360.0)) * 360.0);
+                    hue /= 60.0;
+                    ii = (int)hue;
+                    f = hue - (double)ii;
+                    p = (1.0 - s) * v;
+                    q = (1.0 - (s * f)) * v;
+                    t = (1.0 - (s * (1.0 - f))) * v;
+                    if      (ii == 0) { red = v; green = t; blue = p; }
+                    else if (ii == 1) { red = q; green = v; blue = p; }
+                    else if (ii == 2) { red = p; green = v; blue = t; }
+                    else if (ii == 3) { red = p; green = q; blue = v; }
+                    else if (ii == 4) { red = t; green = p; blue = v; }
+                    else if (ii == 5) { red = v; green = p; blue = q; }
+                    *dest++ = (uch)(red * 255.0);
+                    *dest++ = (uch)(green * 255.0);
+                    *dest++ = (uch)(blue * 255.0);
+                }
+            }
+        }
+        fprintf(stderr, "done.\n");
+        fflush(stderr);
+    }
+/*---------------------------------------------------------------------------
+    Blast background image to display buffer before beginning PNG decode;
+    calling function will handle invalidation and UpdateWindow() call.
+  ---------------------------------------------------------------------------*/
+    for (row = 0;  row < rpng2_info.height;  ++row) {
+        src = bg_data + row*bg_rowbytes;
+        dest = wimage_data + row*wimage_rowbytes;
+        for (i = rpng2_info.width;  i > 0;  --i) {
+            r1 = *src++;
+            g1 = *src++;
+            b1 = *src++;
+            *dest++ = b1;
+            *dest++ = g1;   /* note reverse order */
+            *dest++ = r1;
+        }
+    }
+    return 0;
+} /* end function rpng2_win_load_bg_image() */
+static void rpng2_win_display_row(ulg row)
+{
+    uch bg_red   = rpng2_info.bg_red;
+    uch bg_green = rpng2_info.bg_green;
+    uch bg_blue  = rpng2_info.bg_blue;
+    uch *src, *src2=NULL, *dest;
+    uch r, g, b, a;
+    ulg i;
+    static int rows=0;
+    static ulg firstrow;
+/*---------------------------------------------------------------------------
+    rows and firstrow simply track how many rows (and which ones) have not
+    yet been displayed; alternatively, we could call InvalidateRect() for
+    every row and not bother with the records-keeping.
+  ---------------------------------------------------------------------------*/
+    Trace((stderr, "beginning rpng2_win_display_row()\n"))
+    if (rows == 0)
+        firstrow = row;   /* first row not yet displayed */
+    ++rows;   /* count of rows received but not yet displayed */
+/*---------------------------------------------------------------------------
+    Aside from the use of the rpng2_info struct and the lack of an outer
+    loop (over rows), this routine is identical to rpng_win_display_image()
+    in the non-progressive version of the program.
+  ---------------------------------------------------------------------------*/
+    src = rpng2_info.image_data + row*rpng2_info.rowbytes;
+    if (bg_image)
+        src2 = bg_data + row*bg_rowbytes;
+    dest = wimage_data + row*wimage_rowbytes;
+    if (rpng2_info.channels == 3) {
+        for (i = rpng2_info.width;  i > 0;  --i) {
+            r = *src++;
+            g = *src++;
+            b = *src++;
+            *dest++ = b;
+            *dest++ = g;   /* note reverse order */
+            *dest++ = r;
+        }
+    } else /* if (rpng2_info.channels == 4) */ {
+        for (i = rpng2_info.width;  i > 0;  --i) {
+            r = *src++;
+            g = *src++;
+            b = *src++;
+            a = *src++;
+            if (bg_image) {
+                bg_red   = *src2++;
+                bg_green = *src2++;
+                bg_blue  = *src2++;
+            }
+            if (a == 255) {
+                *dest++ = b;
+                *dest++ = g;
+                *dest++ = r;
+            } else if (a == 0) {
+                *dest++ = bg_blue;
+                *dest++ = bg_green;
+                *dest++ = bg_red;
+            } else {
+                /* this macro (copied from png.h) composites the
+                 * foreground and background values and puts the
+                 * result into the first argument; there are no
+                 * side effects with the first argument */
+                alpha_composite(*dest++, b, a, bg_blue);
+                alpha_composite(*dest++, g, a, bg_green);
+                alpha_composite(*dest++, r, a, bg_red);
+            }
+        }
+    }
+/*---------------------------------------------------------------------------
+    Display after every 16 rows or when on last row.  (Region may include
+    previously displayed lines due to interlacing--i.e., not contiguous.)
+  ---------------------------------------------------------------------------*/
+    if ((rows & 0xf) == 0 || row == rpng2_info.height-1) {
+        RECT rect;
+        rect.left = 0L;
+        rect.top = (LONG)firstrow;
+        rect.right = (LONG)rpng2_info.width;       /* possibly off by one? */
+        rect.bottom = (LONG)row + 1L;              /* possibly off by one? */
+        InvalidateRect(global_hwnd, &rect, FALSE);
+        UpdateWindow(global_hwnd);                 /* similar to XFlush() */
+        rows = 0;
+    }
+} /* end function rpng2_win_display_row() */
+static void rpng2_win_finish_display()
+{
+    Trace((stderr, "beginning rpng2_win_finish_display()\n"))
+    /* last row has already been displayed by rpng2_win_display_row(), so
+     * we have nothing to do here except set a flag and let the user know
+     * that the image is done */
+    rpng2_info.state = kDone;
+    printf(
+#ifndef __CYGWIN__
+      "Done.  Press Q, Esc or mouse button 1 (within image window) to quit.\n"
+#else
+      "Done.  Press mouse button 1 (within image window) to quit.\n"
+#endif
+    );
+    fflush(stdout);
+}
+static void rpng2_win_cleanup()
+{
+    if (bg_image && bg_data) {
+        free(bg_data);
+        bg_data = NULL;
+    }
+    if (rpng2_info.image_data) {
+        free(rpng2_info.image_data);
+        rpng2_info.image_data = NULL;
+    }
+    if (rpng2_info.row_pointers) {
+        free(rpng2_info.row_pointers);
+        rpng2_info.row_pointers = NULL;
+    }
+    if (dib) {
+        free(dib);
+        dib = NULL;
+    }
+}
+LRESULT CALLBACK rpng2_win_wndproc(HWND hwnd, UINT iMsg, WPARAM wP, LPARAM lP)
+{
+    HDC         hdc;
+    PAINTSTRUCT ps;
+    int rc;
+    switch (iMsg) {
+        case WM_CREATE:
+            /* one-time processing here, if any */
+            return 0;
+        case WM_PAINT:
+            hdc = BeginPaint(hwnd, &ps);
+            rc = StretchDIBits(hdc, 0, 0, rpng2_info.width, rpng2_info.height,
+                                    0, 0, rpng2_info.width, rpng2_info.height,
+                                    wimage_data, (BITMAPINFO *)bmih,
+                                    0, SRCCOPY);
+            EndPaint(hwnd, &ps);
+            return 0;
+        /* wait for the user to tell us when to quit */
+        case WM_CHAR:
+            switch (wP) {       /* only need one, so ignore repeat count */
+                case 'q':
+                case 'Q':
+                case 0x1B:      /* Esc key */
+                    PostQuitMessage(0);
+            }
+            return 0;
+        case WM_LBUTTONDOWN:    /* another way of quitting */
+        case WM_DESTROY:
+            PostQuitMessage(0);
+            return 0;
+    }
+    return DefWindowProc(hwnd, iMsg, wP, lP);
+}
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/rpng2-x.c b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/rpng2-x.c
new file mode 100644
index 0000000..6c687db
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/rpng2-x.c
@@ -0,0 +1,2107 @@
+/*---------------------------------------------------------------------------
+   rpng2 - progressive-model PNG display program                  rpng2-x.c
+   This program decodes and displays PNG files progressively, as if it were
+   a web browser (though the front end is only set up to read from files).
+   It supports gamma correction, user-specified background colors, and user-
+   specified background patterns (for transparent images).  This version is
+   for the X Window System (tested by the author under Unix and by Martin
+   Zinser under OpenVMS; may work under OS/2 with a little tweaking).
+   Thanks to Adam Costello and Pieter S. van der Meulen for the "diamond"
+   and "radial waves" patterns, respectively.
+   to do (someday, maybe):
+    - fix expose/redraw code:  don't draw entire row if only part exposed
+    - 8-bit (colormapped) X support
+    - finish resizable checkerboard-gradient (sizes 4-128?)
+    - use %.1023s to simplify truncation of title-bar string?
+  ---------------------------------------------------------------------------
+   Changelog:
+    - 1.01:  initial public release
+    - 1.02:  modified to allow abbreviated options; fixed char/uchar mismatch
+    - 1.10:  added support for non-default visuals; fixed X pixel-conversion
+    - 1.11:  added -usleep option for demos; fixed command-line parsing bug
+    - 1.12:  added -pause option for demos and testing
+    - 1.20:  added runtime MMX-enabling/disabling and new -mmx* options
+    - 1.21:  fixed some small X memory leaks (thanks to Fran�ois Petitjean)
+    - 1.22:  fixed XFreeGC() crash bug (thanks to Patrick Welche)
+    - 1.23:  added -bgpat 0 mode (std white/gray checkerboard, 8x8 squares)
+    - 1.30:  added -loop option for -bgpat (ifdef FEATURE_LOOP); fixed bpp =
+              24; added support for X resources (thanks to Gerhard Niklasch)
+    - 1.31:  added code to skip unused chunks (thanks to Glenn Randers-Pehrson)
+    - 1.32:  added AMD64/EM64T support (__x86_64__); added basic expose/redraw
+              handling
+    - 2.00:  dual-licensed (added GNU GPL)
+    - 2.01:  fixed 64-bit typo in readpng2.c; fixed -pause usage description
+    - 2.02:  fixed improper display of usage screen on PNG error(s); fixed
+              unexpected-EOF and file-read-error cases; fixed Trace() cut-and-
+              paste bugs
+    - 2.03:  deleted runtime MMX-enabling/disabling and obsolete -mmx* options
+  ---------------------------------------------------------------------------
+      Copyright (c) 1998-2008 Greg Roelofs.  All rights reserved.
+      This software is provided "as is," without warranty of any kind,
+      express or implied.  In no event shall the author or contributors
+      be held liable for any damages arising in any way from the use of
+      this software.
+      The contents of this file are DUAL-LICENSED.  You may modify and/or
+      redistribute this software according to the terms of one of the
+      following two licenses (at your option):
+      LICENSE 1 ("BSD-like with advertising clause"):
+      Permission is granted to anyone to use this software for any purpose,
+      including commercial applications, and to alter it and redistribute
+      it freely, subject to the following restrictions:
+      1. Redistributions of source code must retain the above copyright
+         notice, disclaimer, and this list of conditions.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, disclaimer, and this list of conditions in the documenta-
+         tion and/or other materials provided with the distribution.
+      3. All advertising materials mentioning features or use of this
+         software must display the following acknowledgment:
+            This product includes software developed by Greg Roelofs
+            and contributors for the book, "PNG: The Definitive Guide,"
+            published by O'Reilly and Associates.
+      LICENSE 2 (GNU GPL v2 or later):
+      This program is free software; you can redistribute it and/or modify
+      it under the terms of the GNU General Public License as published by
+      the Free Software Foundation; either version 2 of the License, or
+      (at your option) any later version.
+      This program is distributed in the hope that it will be useful,
+      but WITHOUT ANY WARRANTY; without even the implied warranty of
+      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+      GNU General Public License for more details.
+      You should have received a copy of the GNU General Public License
+      along with this program; if not, write to the Free Software Foundation,
+      Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+  ---------------------------------------------------------------------------*/
+#define PROGNAME  "rpng2-x"
+#define LONGNAME  "Progressive PNG Viewer for X"
+#define VERSION   "2.03 of 25 February 2010"
+#define RESNAME   "rpng2"       /* our X resource application name */
+#define RESCLASS  "Rpng"       /* our X resource class name */
+#include <stdio.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <string.h>
+#include <setjmp.h>       /* for jmpbuf declaration in readpng2.h */
+#include <time.h>
+#include <math.h>         /* only for PvdM background code */
+#include <X11/Xlib.h>
+#include <X11/Xutil.h>
+#include <X11/Xos.h>
+#include <X11/keysym.h>   /* defines XK_* macros */
+#ifdef VMS
+#  include <unistd.h>
+#endif
+/* all for PvdM background code: */
+#ifndef PI
+#  define PI             3.141592653589793238
+#endif
+#define PI_2             (PI*0.5)
+#define INV_PI_360       (360.0 / PI)
+#define MAX(a,b)         (a>b?a:b)
+#define MIN(a,b)         (a<b?a:b)
+#define CLIP(a,min,max)  MAX(min,MIN((a),max))
+#define ABS(a)           ((a)<0?-(a):(a))
+#define CLIP8P(c)        MAX(0,(MIN((c),255)))   /* 8-bit pos. integer (uch) */
+#define ROUNDF(f)        ((int)(f + 0.5))
+#define QUIT(e,k) ((e.type == ButtonPress && e.xbutton.button == Button1) ||  \
+                  (e.type == KeyPress &&   /*  v--- or 1 for shifted keys */  \
+                  ((k = XLookupKeysym(&e.xkey, 0)) == XK_q || k == XK_Escape)))
+#define NO_24BIT_MASKS /* undef case not fully written--only for redisplay() */
+#define rgb1_max   bg_freq
+#define rgb1_min   bg_gray
+#define rgb2_max   bg_bsat
+#define rgb2_min   bg_brot
+/* #define DEBUG */     /* this enables the Trace() macros */
+#include "readpng2.h"   /* typedefs, common macros, readpng2 prototypes */
+/* could just include png.h, but this macro is the only thing we need
+ * (name and typedefs changed to local versions); note that side effects
+ * only happen with alpha (which could easily be avoided with
+ * "ush acopy = (alpha);") */
+#define alpha_composite(composite, fg, alpha, bg) {               \
+    ush temp = ((ush)(fg)*(ush)(alpha) +                          \
+                (ush)(bg)*(ush)(255 - (ush)(alpha)) + (ush)128);  \
+    (composite) = (uch)((temp + (temp >> 8)) >> 8);               \
+}
+#define INBUFSIZE 4096   /* with pseudo-timing on (1 sec delay/block), this
+                          *  block size corresponds roughly to a download
+                          *  speed 10% faster than theoretical 33.6K maximum
+                          *  (assuming 8 data bits, 1 stop bit and no other
+                          *  overhead) */
+/* local prototypes */
+static void rpng2_x_init (void);
+static int  rpng2_x_create_window (void);
+static int  rpng2_x_load_bg_image (void);
+static void rpng2_x_display_row (ulg row);
+static void rpng2_x_finish_display (void);
+static void rpng2_x_redisplay_image (ulg startcol, ulg startrow,
+                                     ulg width, ulg height);
+#ifdef FEATURE_LOOP
+static void rpng2_x_reload_bg_image (void);
+static int  is_number (char *p);
+#endif
+static void rpng2_x_cleanup (void);
+static int  rpng2_x_msb (ulg u32val);
+static char titlebar[1024], *window_name = titlebar;
+static char *appname = LONGNAME;
+static char *icon_name = PROGNAME;
+static char *res_name = RESNAME;
+static char *res_class = RESCLASS;
+static char *filename;
+static FILE *infile;
+static mainprog_info rpng2_info;
+static uch inbuf[INBUFSIZE];
+static int incount;
+static int pat = 6;        /* must be less than num_bgpat */
+static int bg_image = 0;
+static int bgscale, bgscale_default = 16;
+static ulg bg_rowbytes;
+static uch *bg_data;
+int pause_after_pass = FALSE;
+int demo_timing = FALSE;
+ulg usleep_duration = 0L;
+static struct rgb_color {
+    uch r, g, b;
+} rgb[] = {
+    {  0,   0,   0},    /*  0:  black */
+    {255, 255, 255},    /*  1:  white */
+    {173, 132,  57},    /*  2:  tan */
+    { 64, 132,   0},    /*  3:  medium green */
+    {189, 117,   1},    /*  4:  gold */
+    {253, 249,   1},    /*  5:  yellow */
+    {  0,   0, 255},    /*  6:  blue */
+    {  0,   0, 120},    /*  7:  medium blue */
+    {255,   0, 255},    /*  8:  magenta */
+    { 64,   0,  64},    /*  9:  dark magenta */
+    {255,   0,   0},    /* 10:  red */
+    { 64,   0,   0},    /* 11:  dark red */
+    {255, 127,   0},    /* 12:  orange */
+    {192,  96,   0},    /* 13:  darker orange */
+    { 24,  60,   0},    /* 14:  dark green-yellow */
+    { 85, 125, 200},    /* 15:  ice blue */
+    {192, 192, 192}     /* 16:  Netscape/Mosaic gray */
+};
+/* not used for now, but should be for error-checking:
+static int num_rgb = sizeof(rgb) / sizeof(struct rgb_color);
+ */
+/*
+    This whole struct is a fairly cheesy way to keep the number of
+    command-line options to a minimum.  The radial-waves background
+    type is a particularly poor fit to the integer elements of the
+    struct...but a few macros and a little fixed-point math will do
+    wonders for ya.
+    type bits:
+       F E D C B A 9 8 7 6 5 4 3 2 1 0
+                             | | | | |
+                             | | +-+-+-- 0 = sharp-edged checkerboard
+                             | |         1 = soft diamonds
+                             | |         2 = radial waves
+                             | |       3-7 = undefined
+                             | +-- gradient #2 inverted?
+                             +-- alternating columns inverted?
+ */
+static struct background_pattern {
+    ush type;
+    int rgb1_max, rgb1_min;     /* or bg_freq, bg_gray */
+    int rgb2_max, rgb2_min;     /* or bg_bsat, bg_brot (both scaled by 10)*/
+} bg[] = {
+    {0,     1,1, 16,16},        /* checkered:  white vs. light gray (basic) */
+    {0+8,   2,0,  1,15},        /* checkered:  tan/black vs. white/ice blue */
+    {0+24,  2,0,  1,0},         /* checkered:  tan/black vs. white/black */
+    {0+8,   4,5,  0,2},         /* checkered:  gold/yellow vs. black/tan */
+    {0+8,   4,5,  0,6},         /* checkered:  gold/yellow vs. black/blue */
+    {0,     7,0,  8,9},         /* checkered:  deep blue/black vs. magenta */
+    {0+8,  13,0,  5,14},        /* checkered:  orange/black vs. yellow */
+    {0+8,  12,0, 10,11},        /* checkered:  orange/black vs. red */
+    {1,     7,0,  8,0},         /* diamonds:  deep blue/black vs. magenta */
+    {1,    12,0, 11,0},         /* diamonds:  orange vs. dark red */
+    {1,    10,0,  7,0},         /* diamonds:  red vs. medium blue */
+    {1,     4,0,  5,0},         /* diamonds:  gold vs. yellow */
+    {1,     3,0,  0,0},         /* diamonds:  medium green vs. black */
+    {2,    16, 100,  20,   0},  /* radial:  ~hard radial color-beams */
+    {2,    18, 100,  10,   2},  /* radial:  soft, curved radial color-beams */
+    {2,    16, 256, 100, 250},  /* radial:  very tight spiral */
+    {2, 10000, 256,  11,   0}   /* radial:  dipole-moire' (almost fractal) */
+};
+static int num_bgpat = sizeof(bg) / sizeof(struct background_pattern);
+/* X-specific variables */
+static char *displayname;
+static XImage *ximage;
+static Display *display;
+static int depth;
+static Visual *visual;
+static XVisualInfo *visual_list;
+static int RShift, GShift, BShift;
+static ulg RMask, GMask, BMask;
+static Window window;
+static GC gc;
+static Colormap colormap;
+static int have_nondefault_visual = FALSE;
+static int have_colormap = FALSE;
+static int have_window = FALSE;
+static int have_gc = FALSE;
+int main(int argc, char **argv)
+{
+#ifdef sgi
+    char tmpline[80];
+#endif
+    char *p, *bgstr = NULL;
+    int rc, alen, flen;
+    int error = 0;
+    int timing = FALSE;
+    int have_bg = FALSE;
+#ifdef FEATURE_LOOP
+    int loop = FALSE;
+    long loop_interval = -1;            /* seconds (100,000 max) */
+#endif
+    double LUT_exponent;                /* just the lookup table */
+    double CRT_exponent = 2.2;          /* just the monitor */
+    double default_display_exponent;    /* whole display system */
+    XEvent e;
+    KeySym k;
+    /* First initialize a few things, just to be sure--memset takes care of
+     * default background color (black), booleans (FALSE), pointers (NULL),
+     * etc. */
+    displayname = (char *)NULL;
+    filename = (char *)NULL;
+    memset(&rpng2_info, 0, sizeof(mainprog_info));
+    /* Set the default value for our display-system exponent, i.e., the
+     * product of the CRT exponent and the exponent corresponding to
+     * the frame-buffer's lookup table (LUT), if any.  This is not an
+     * exhaustive list of LUT values (e.g., OpenStep has a lot of weird
+     * ones), but it should cover 99% of the current possibilities. */
+#if defined(NeXT)
+    /* third-party utilities can modify the default LUT exponent */
+    LUT_exponent = 1.0 / 2.2;
+    /*
+    if (some_next_function_that_returns_gamma(&next_gamma))
+        LUT_exponent = 1.0 / next_gamma;
+     */
+#elif defined(sgi)
+    LUT_exponent = 1.0 / 1.7;
+    /* there doesn't seem to be any documented function to
+     * get the "gamma" value, so we do it the hard way */
+    infile = fopen("/etc/config/system.glGammaVal", "r");
+    if (infile) {
+        double sgi_gamma;
+        fgets(tmpline, 80, infile);
+        fclose(infile);
+        sgi_gamma = atof(tmpline);
+        if (sgi_gamma > 0.0)
+            LUT_exponent = 1.0 / sgi_gamma;
+    }
+#elif defined(Macintosh)
+    LUT_exponent = 1.8 / 2.61;
+    /*
+    if (some_mac_function_that_returns_gamma(&mac_gamma))
+        LUT_exponent = mac_gamma / 2.61;
+     */
+#else
+    LUT_exponent = 1.0;   /* assume no LUT:  most PCs */
+#endif
+    /* the defaults above give 1.0, 1.3, 1.5 and 2.2, respectively: */
+    default_display_exponent = LUT_exponent * CRT_exponent;
+    /* If the user has set the SCREEN_GAMMA environment variable as suggested
+     * (somewhat imprecisely) in the libpng documentation, use that; otherwise
+     * use the default value we just calculated.  Either way, the user may
+     * override this via a command-line option. */
+    if ((p = getenv("SCREEN_GAMMA")) != NULL)
+        rpng2_info.display_exponent = atof(p);
+    else
+        rpng2_info.display_exponent = default_display_exponent;
+    /* Now parse the command line for options and the PNG filename. */
+    while (*++argv && !error) {
+        if (!strncmp(*argv, "-display", 2)) {
+            if (!*++argv)
+                ++error;
+            else
+                displayname = *argv;
+        } else if (!strncmp(*argv, "-gamma", 2)) {
+            if (!*++argv)
+                ++error;
+            else {
+                rpng2_info.display_exponent = atof(*argv);
+                if (rpng2_info.display_exponent <= 0.0)
+                    ++error;
+            }
+        } else if (!strncmp(*argv, "-bgcolor", 4)) {
+            if (!*++argv)
+                ++error;
+            else {
+                bgstr = *argv;
+                if (strlen(bgstr) != 7 || bgstr[0] != '#')
+                    ++error;
+                else {
+                    have_bg = TRUE;
+                    bg_image = FALSE;
+                }
+            }
+        } else if (!strncmp(*argv, "-bgpat", 4)) {
+            if (!*++argv)
+                ++error;
+            else {
+                pat = atoi(*argv);
+                if (pat >= 0 && pat < num_bgpat) {
+                    bg_image = TRUE;
+                    have_bg = FALSE;
+                } else
+                    ++error;
+            }
+        } else if (!strncmp(*argv, "-usleep", 2)) {
+            if (!*++argv)
+                ++error;
+            else {
+                usleep_duration = (ulg)atol(*argv);
+                demo_timing = TRUE;
+            }
+        } else if (!strncmp(*argv, "-pause", 2)) {
+            pause_after_pass = TRUE;
+        } else if (!strncmp(*argv, "-timing", 2)) {
+            timing = TRUE;
+#ifdef FEATURE_LOOP
+        } else if (!strncmp(*argv, "-loop", 2)) {
+            loop = TRUE;
+            if (!argv[1] || !is_number(argv[1]))
+                loop_interval = 2;
+            else {
+                ++argv;
+                loop_interval = atol(*argv);
+                if (loop_interval < 0)
+                    loop_interval = 2;
+                else if (loop_interval > 100000)   /* bit more than one day */
+                    loop_interval = 100000;
+            }
+#endif
+        } else {
+            if (**argv != '-') {
+                filename = *argv;
+                if (argv[1])   /* shouldn't be any more args after filename */
+                    ++error;
+            } else
+                ++error;   /* not expecting any other options */
+        }
+    }
+    if (!filename)
+        ++error;
+    /* print usage screen if any errors up to this point */
+    if (error) {
+        fprintf(stderr, "\n%s %s:  %s\n\n", PROGNAME, VERSION, appname);
+        readpng2_version_info();
+        fprintf(stderr, "\n"
+          "Usage:  %s [-display xdpy] [-gamma exp] [-bgcolor bg | -bgpat pat]\n"
+#ifdef FEATURE_LOOP
+          "        %*s [-usleep dur | -timing] [-pause] [-loop [sec]] file.png\n\n"
+#else
+          "        %*s [-usleep dur | -timing] [-pause] file.png\n\n"
+#endif
+          "    xdpy\tname of the target X display (e.g., ``hostname:0'')\n"
+          "    exp \ttransfer-function exponent (``gamma'') of the display\n"
+          "\t\t  system in floating-point format (e.g., ``%.1f''); equal\n"
+          "\t\t  to the product of the lookup-table exponent (varies)\n"
+          "\t\t  and the CRT exponent (usually 2.2); must be positive\n"
+          "    bg  \tdesired background color in 7-character hex RGB format\n"
+          "\t\t  (e.g., ``#ff7700'' for orange:  same as HTML colors);\n"
+          "\t\t  used with transparent images; overrides -bgpat\n"
+          "    pat \tdesired background pattern number (0-%d); used with\n"
+          "\t\t  transparent images; overrides -bgcolor\n"
+#ifdef FEATURE_LOOP
+          "    -loop\tloops through background images after initial display\n"
+          "\t\t  is complete (depends on -bgpat)\n"
+          "    sec \tseconds to display each background image (default = 2)\n"
+#endif
+          "    dur \tduration in microseconds to wait after displaying each\n"
+          "\t\t  row (for demo purposes)\n"
+          "    -timing\tenables delay for every block read, to simulate modem\n"
+          "\t\t  download of image (~36 Kbps)\n"
+          "    -pause\tpauses after displaying each pass until mouse clicked\n"
+          "\nPress Q, Esc or mouse button 1 (within image window, after image\n"
+          "is displayed) to quit.\n"
+          "\n", PROGNAME,
+          (int)strlen(PROGNAME), " ", default_display_exponent, num_bgpat-1);
+        exit(1);
+    }
+    if (!(infile = fopen(filename, "rb"))) {
+        fprintf(stderr, PROGNAME ":  can't open PNG file [%s]\n", filename);
+        ++error;
+    } else {
+        incount = fread(inbuf, 1, INBUFSIZE, infile);
+        if (incount < 8 || !readpng2_check_sig(inbuf, 8)) {
+            fprintf(stderr, PROGNAME
+              ":  [%s] is not a PNG file: incorrect signature\n",
+              filename);
+            ++error;
+        } else if ((rc = readpng2_init(&rpng2_info)) != 0) {
+            switch (rc) {
+                case 2:
+                    fprintf(stderr, PROGNAME
+                      ":  [%s] has bad IHDR (libpng longjmp)\n", filename);
+                    break;
+                case 4:
+                    fprintf(stderr, PROGNAME ":  insufficient memory\n");
+                    break;
+                default:
+                    fprintf(stderr, PROGNAME
+                      ":  unknown readpng2_init() error\n");
+                    break;
+            }
+            ++error;
+        } else {
+            Trace((stderr, "about to call XOpenDisplay()\n"))
+            display = XOpenDisplay(displayname);
+            if (!display) {
+                readpng2_cleanup(&rpng2_info);
+                fprintf(stderr, PROGNAME ":  can't open X display [%s]\n",
+                  displayname? displayname : "default");
+                ++error;
+            }
+        }
+        if (error)
+            fclose(infile);
+    }
+    if (error) {
+        fprintf(stderr, PROGNAME ":  aborting.\n");
+        exit(2);
+    }
+    /* set the title-bar string, but make sure buffer doesn't overflow */
+    alen = strlen(appname);
+    flen = strlen(filename);
+    if (alen + flen + 3 > 1023)
+        sprintf(titlebar, "%s:  ...%s", appname, filename+(alen+flen+6-1023));
+    else
+        sprintf(titlebar, "%s:  %s", appname, filename);
+    /* set some final rpng2_info variables before entering main data loop */
+    if (have_bg) {
+        unsigned r, g, b;   /* this approach quiets compiler warnings */
+        sscanf(bgstr+1, "%2x%2x%2x", &r, &g, &b);
+        rpng2_info.bg_red   = (uch)r;
+        rpng2_info.bg_green = (uch)g;
+        rpng2_info.bg_blue  = (uch)b;
+    } else
+        rpng2_info.need_bgcolor = TRUE;
+    rpng2_info.state = kPreInit;
+    rpng2_info.mainprog_init = rpng2_x_init;
+    rpng2_info.mainprog_display_row = rpng2_x_display_row;
+    rpng2_info.mainprog_finish_display = rpng2_x_finish_display;
+    /* OK, this is the fun part:  call readpng2_decode_data() at the start of
+     * the loop to deal with our first buffer of data (read in above to verify
+     * that the file is a PNG image), then loop through the file and continue
+     * calling the same routine to handle each chunk of data.  It in turn
+     * passes the data to libpng, which will invoke one or more of our call-
+     * backs as decoded data become available.  We optionally call sleep() for
+     * one second per iteration to simulate downloading the image via an analog
+     * modem. */
+    for (;;) {
+        Trace((stderr, "about to call readpng2_decode_data()\n"))
+        if (readpng2_decode_data(&rpng2_info, inbuf, incount))
+            ++error;
+        Trace((stderr, "done with readpng2_decode_data()\n"))
+        if (error || incount != INBUFSIZE || rpng2_info.state == kDone) {
+            if (rpng2_info.state == kDone) {
+                Trace((stderr, "done decoding PNG image\n"))
+            } else if (ferror(infile)) {
+                fprintf(stderr, PROGNAME
+                  ":  error while reading PNG image file\n");
+                exit(3);
+            } else if (feof(infile)) {
+                fprintf(stderr, PROGNAME ":  end of file reached "
+                  "(unexpectedly) while reading PNG image file\n");
+                exit(3);
+            } else /* if (error) */ {
+                /* will print error message below */
+            }
+            break;
+        }
+        if (timing)
+            sleep(1);
+        incount = fread(inbuf, 1, INBUFSIZE, infile);
+    }
+    /* clean up PNG stuff and report any decoding errors */
+    fclose(infile);
+    Trace((stderr, "about to call readpng2_cleanup()\n"))
+    readpng2_cleanup(&rpng2_info);
+    if (error) {
+        fprintf(stderr, PROGNAME ":  libpng error while decoding PNG image\n");
+        exit(3);
+    }
+#ifdef FEATURE_LOOP
+    if (loop && bg_image) {
+        Trace((stderr, "entering -loop loop (FEATURE_LOOP)\n"))
+        for (;;) {
+            int i, use_sleep;
+            struct timeval now, then;
+            /* get current time and add loop_interval to get target time */
+            if (gettimeofday(&then, NULL) == 0) {
+                then.tv_sec += loop_interval;
+                use_sleep = FALSE;
+            } else
+                use_sleep = TRUE;
+            /* do quick check for a quit event but don't wait for it */
+            /* GRR BUG:  should also check for Expose events and redraw... */
+            if (XCheckMaskEvent(display, KeyPressMask | ButtonPressMask, &e))
+                if (QUIT(e,k))
+                    break;
+            /* generate next background image */
+            if (++pat >= num_bgpat)
+                pat = 0;
+            rpng2_x_reload_bg_image();
+            /* wait for timeout, using whatever means are available */
+            if (use_sleep || gettimeofday(&now, NULL) != 0) {
+                for (i = loop_interval;  i > 0;  --i) {
+                    sleep(1);
+                    /* GRR BUG:  also need to check for Expose (and redraw!) */
+                    if (XCheckMaskEvent(display, KeyPressMask | ButtonPressMask,
+                        &e) && QUIT(e,k))
+                        break;
+                }
+            } else {
+                /* Y2038 BUG! */
+                if (now.tv_sec < then.tv_sec ||
+                    (now.tv_sec == then.tv_sec && now.tv_usec < then.tv_usec))
+                {
+                    int quit = FALSE;
+                    long seconds_to_go = then.tv_sec - now.tv_sec;
+                    long usleep_usec;
+                    /* basically chew up most of remaining loop-interval with
+                     *  calls to sleep(1) interleaved with checks for quit
+                     *  events, but also recalc time-to-go periodically; when
+                     *  done, clean up any remaining time with usleep() call
+                     *  (could also use SIGALRM, but signals are a pain...) */
+                    while (seconds_to_go-- > 1) {
+                        int seconds_done = 0;
+                        for (i = seconds_to_go;  i > 0 && !quit;  --i) {
+                            sleep(1);
+                            /* GRR BUG:  need to check for Expose and redraw */
+                            if (XCheckMaskEvent(display, KeyPressMask |
+                                ButtonPressMask, &e) && QUIT(e,k))
+                                quit = TRUE;
+                            if (++seconds_done > 1000)
+                                break;   /* time to redo seconds_to_go meas. */
+                        }
+                        if (quit)
+                            break;
+                        /* OK, more than 1000 seconds since last check:
+                         *  correct the time-to-go measurement for drift */
+                        if (gettimeofday(&now, NULL) == 0) {
+                            if (now.tv_sec >= then.tv_sec)
+                                break;
+                            seconds_to_go = then.tv_sec - now.tv_sec;
+                        } else
+                            ++seconds_to_go;  /* restore what we subtracted */
+                    }
+                    if (quit)
+                        break;   /* breaks outer do-loop, skips redisplay */
+                    /* since difference between "now" and "then" is already
+                     *  eaten up to within a couple of seconds, don't need to
+                     *  worry about overflow--but might have overshot (neg.) */
+                    if (gettimeofday(&now, NULL) == 0) {
+                        usleep_usec = 1000000L*(then.tv_sec - now.tv_sec) +
+                          then.tv_usec - now.tv_usec;
+                        if (usleep_usec > 0)
+                            usleep((ulg)usleep_usec);
+                    }
+                }
+            }
+            /* composite image against new background and display (note that
+             *  we do not take into account the time spent doing this...) */
+            rpng2_x_redisplay_image (0, 0, rpng2_info.width, rpng2_info.height);
+        }
+    } else /* FALL THROUGH and do the normal thing */
+#endif /* FEATURE_LOOP */
+    /* wait for the user to tell us when to quit */
+    if (rpng2_info.state >= kWindowInit) {
+        Trace((stderr, "entering final wait-for-quit-event loop\n"))
+        do {
+            XNextEvent(display, &e);
+            if (e.type == Expose) {
+                XExposeEvent *ex = (XExposeEvent *)&e;
+                rpng2_x_redisplay_image (ex->x, ex->y, ex->width, ex->height);
+            }
+        } while (!QUIT(e,k));
+    } else {
+        fprintf(stderr, PROGNAME ":  init callback never called:  probable "
+          "libpng error while decoding PNG metadata\n");
+        exit(4);
+    }
+    /* we're done:  clean up all image and X resources and go away */
+    Trace((stderr, "about to call rpng2_x_cleanup()\n"))
+    rpng2_x_cleanup();
+    return 0;
+}
+/* this function is called by readpng2_info_callback() in readpng2.c, which
+ * in turn is called by libpng after all of the pre-IDAT chunks have been
+ * read and processed--i.e., we now have enough info to finish initializing */
+static void rpng2_x_init(void)
+{
+    ulg i;
+    ulg rowbytes = rpng2_info.rowbytes;
+    Trace((stderr, "beginning rpng2_x_init()\n"))
+    Trace((stderr, "  rowbytes = %d\n", rpng2_info.rowbytes))
+    Trace((stderr, "  width  = %ld\n", rpng2_info.width))
+    Trace((stderr, "  height = %ld\n", rpng2_info.height))
+    rpng2_info.image_data = (uch *)malloc(rowbytes * rpng2_info.height);
+    if (!rpng2_info.image_data) {
+        readpng2_cleanup(&rpng2_info);
+        return;
+    }
+    rpng2_info.row_pointers = (uch **)malloc(rpng2_info.height * sizeof(uch *));
+    if (!rpng2_info.row_pointers) {
+        free(rpng2_info.image_data);
+        rpng2_info.image_data = NULL;
+        readpng2_cleanup(&rpng2_info);
+        return;
+    }
+    for (i = 0;  i < rpng2_info.height;  ++i)
+        rpng2_info.row_pointers[i] = rpng2_info.image_data + i*rowbytes;
+    /* do the basic X initialization stuff, make the window, and fill it with
+     * the user-specified, file-specified or default background color or
+     * pattern */
+    if (rpng2_x_create_window()) {
+        /* GRR TEMPORARY HACK:  this is fundamentally no different from cases
+         * above; libpng should call our error handler to longjmp() back to us
+         * when png_ptr goes away.  If we/it segfault instead, seems like a
+         * libpng bug... */
+        /* we're here via libpng callback, so if window fails, clean and bail */
+        readpng2_cleanup(&rpng2_info);
+        rpng2_x_cleanup();
+        exit(2);
+    }
+    rpng2_info.state = kWindowInit;
+}
+static int rpng2_x_create_window(void)
+{
+    ulg bg_red   = rpng2_info.bg_red;
+    ulg bg_green = rpng2_info.bg_green;
+    ulg bg_blue  = rpng2_info.bg_blue;
+    ulg bg_pixel = 0L;
+    ulg attrmask;
+    int need_colormap = FALSE;
+    int screen, pad;
+    uch *xdata;
+    Window root;
+    XEvent e;
+    XGCValues gcvalues;
+    XSetWindowAttributes attr;
+    XTextProperty windowName, *pWindowName = &windowName;
+    XTextProperty iconName, *pIconName = &iconName;
+    XVisualInfo visual_info;
+    XSizeHints *size_hints;
+    XWMHints *wm_hints;
+    XClassHint *class_hints;
+    Trace((stderr, "beginning rpng2_x_create_window()\n"))
+    screen = DefaultScreen(display);
+    depth = DisplayPlanes(display, screen);
+    root = RootWindow(display, screen);
+#ifdef DEBUG
+    XSynchronize(display, True);
+#endif
+    if (depth != 16 && depth != 24 && depth != 32) {
+        int visuals_matched = 0;
+        Trace((stderr, "default depth is %d:  checking other visuals\n",
+          depth))
+        /* 24-bit first */
+        visual_info.screen = screen;
+        visual_info.depth = 24;
+        visual_list = XGetVisualInfo(display,
+          VisualScreenMask | VisualDepthMask, &visual_info, &visuals_matched);
+        if (visuals_matched == 0) {
+/* GRR:  add 15-, 16- and 32-bit TrueColor visuals (also DirectColor?) */
+            fprintf(stderr, "default screen depth %d not supported, and no"
+              " 24-bit visuals found\n", depth);
+            return 2;
+        }
+        Trace((stderr, "XGetVisualInfo() returned %d 24-bit visuals\n",
+          visuals_matched))
+        visual = visual_list[0].visual;
+        depth = visual_list[0].depth;
+/*
+        colormap_size = visual_list[0].colormap_size;
+        visual_class = visual->class;
+        visualID = XVisualIDFromVisual(visual);
+ */
+        have_nondefault_visual = TRUE;
+        need_colormap = TRUE;
+    } else {
+        XMatchVisualInfo(display, screen, depth, TrueColor, &visual_info);
+        visual = visual_info.visual;
+    }
+    RMask = visual->red_mask;
+    GMask = visual->green_mask;
+    BMask = visual->blue_mask;
+/* GRR:  add/check 8-bit support */
+    if (depth == 8 || need_colormap) {
+        colormap = XCreateColormap(display, root, visual, AllocNone);
+        if (!colormap) {
+            fprintf(stderr, "XCreateColormap() failed\n");
+            return 2;
+        }
+        have_colormap = TRUE;
+        if (depth == 8)
+            bg_image = FALSE;   /* gradient just wastes palette entries */
+    }
+    if (depth == 15 || depth == 16) {
+        RShift = 15 - rpng2_x_msb(RMask);    /* these are right-shifts */
+        GShift = 15 - rpng2_x_msb(GMask);
+        BShift = 15 - rpng2_x_msb(BMask);
+    } else if (depth > 16) {
+        RShift = rpng2_x_msb(RMask) - 7;     /* these are left-shifts */
+        GShift = rpng2_x_msb(GMask) - 7;
+        BShift = rpng2_x_msb(BMask) - 7;
+    }
+    if (depth >= 15 && (RShift < 0 || GShift < 0 || BShift < 0)) {
+        fprintf(stderr, "rpng2 internal logic error:  negative X shift(s)!\n");
+        return 2;
+    }
+/*---------------------------------------------------------------------------
+    Finally, create the window.
+  ---------------------------------------------------------------------------*/
+    attr.backing_store = Always;
+    attr.event_mask = ExposureMask | KeyPressMask | ButtonPressMask;
+    attrmask = CWBackingStore | CWEventMask;
+    if (have_nondefault_visual) {
+        attr.colormap = colormap;
+        attr.background_pixel = 0;
+        attr.border_pixel = 1;
+        attrmask |= CWColormap | CWBackPixel | CWBorderPixel;
+    }
+    window = XCreateWindow(display, root, 0, 0, rpng2_info.width,
+      rpng2_info.height, 0, depth, InputOutput, visual, attrmask, &attr);
+    if (window == None) {
+        fprintf(stderr, "XCreateWindow() failed\n");
+        return 2;
+    } else
+        have_window = TRUE;
+    if (depth == 8)
+        XSetWindowColormap(display, window, colormap);
+    if (!XStringListToTextProperty(&window_name, 1, pWindowName))
+        pWindowName = NULL;
+    if (!XStringListToTextProperty(&icon_name, 1, pIconName))
+        pIconName = NULL;
+    /* OK if either hints allocation fails; XSetWMProperties() allows NULLs */
+    if ((size_hints = XAllocSizeHints()) != NULL) {
+        /* window will not be resizable */
+        size_hints->flags = PMinSize | PMaxSize;
+        size_hints->min_width = size_hints->max_width = (int)rpng2_info.width;
+        size_hints->min_height = size_hints->max_height =
+          (int)rpng2_info.height;
+    }
+    if ((wm_hints = XAllocWMHints()) != NULL) {
+        wm_hints->initial_state = NormalState;
+        wm_hints->input = True;
+     /* wm_hints->icon_pixmap = icon_pixmap; */
+        wm_hints->flags = StateHint | InputHint  /* | IconPixmapHint */ ;
+    }
+    if ((class_hints = XAllocClassHint()) != NULL) {
+        class_hints->res_name = res_name;
+        class_hints->res_class = res_class;
+    }
+    XSetWMProperties(display, window, pWindowName, pIconName, NULL, 0,
+      size_hints, wm_hints, class_hints);
+    /* various properties and hints no longer needed; free memory */
+    if (pWindowName)
+       XFree(pWindowName->value);
+    if (pIconName)
+       XFree(pIconName->value);
+    if (size_hints)
+        XFree(size_hints);
+    if (wm_hints)
+       XFree(wm_hints);
+    if (class_hints)
+       XFree(class_hints);
+    XMapWindow(display, window);
+    gc = XCreateGC(display, window, 0, &gcvalues);
+    have_gc = TRUE;
+/*---------------------------------------------------------------------------
+    Allocate memory for the X- and display-specific version of the image.
+  ---------------------------------------------------------------------------*/
+    if (depth == 24 || depth == 32) {
+        xdata = (uch *)malloc(4*rpng2_info.width*rpng2_info.height);
+        pad = 32;
+    } else if (depth == 16) {
+        xdata = (uch *)malloc(2*rpng2_info.width*rpng2_info.height);
+        pad = 16;
+    } else /* depth == 8 */ {
+        xdata = (uch *)malloc(rpng2_info.width*rpng2_info.height);
+        pad = 8;
+    }
+    if (!xdata) {
+        fprintf(stderr, PROGNAME ":  unable to allocate image memory\n");
+        return 4;
+    }
+    ximage = XCreateImage(display, visual, depth, ZPixmap, 0,
+      (char *)xdata, rpng2_info.width, rpng2_info.height, pad, 0);
+    if (!ximage) {
+        fprintf(stderr, PROGNAME ":  XCreateImage() failed\n");
+        free(xdata);
+        return 3;
+    }
+    /* to avoid testing the byte order every pixel (or doubling the size of
+     * the drawing routine with a giant if-test), we arbitrarily set the byte
+     * order to MSBFirst and let Xlib worry about inverting things on little-
+     * endian machines (e.g., Linux/x86, old VAXen, etc.)--this is not the
+     * most efficient approach (the giant if-test would be better), but in
+     * the interest of clarity, we'll take the easy way out... */
+    ximage->byte_order = MSBFirst;
+/*---------------------------------------------------------------------------
+    Fill window with the specified background color (default is black) or
+    faked "background image" (but latter is disabled if 8-bit; gradients
+    just waste palette entries).
+  ---------------------------------------------------------------------------*/
+    if (bg_image)
+        rpng2_x_load_bg_image();    /* resets bg_image if fails */
+    if (!bg_image) {
+        if (depth == 24 || depth == 32) {
+            bg_pixel = (bg_red   << RShift) |
+                       (bg_green << GShift) |
+                       (bg_blue  << BShift);
+        } else if (depth == 16) {
+            bg_pixel = (((bg_red   << 8) >> RShift) & RMask) |
+                       (((bg_green << 8) >> GShift) & GMask) |
+                       (((bg_blue  << 8) >> BShift) & BMask);
+        } else /* depth == 8 */ {
+            /* GRR:  add 8-bit support */
+        }
+        XSetForeground(display, gc, bg_pixel);
+        XFillRectangle(display, window, gc, 0, 0, rpng2_info.width,
+          rpng2_info.height);
+    }
+/*---------------------------------------------------------------------------
+    Wait for first Expose event to do any drawing, then flush and return.
+  ---------------------------------------------------------------------------*/
+    do
+        XNextEvent(display, &e);
+    while (e.type != Expose || e.xexpose.count);
+    XFlush(display);
+    return 0;
+} /* end function rpng2_x_create_window() */
+static int rpng2_x_load_bg_image(void)
+{
+    uch *src;
+    char *dest;
+    uch r1, r2, g1, g2, b1, b2;
+    uch r1_inv, r2_inv, g1_inv, g2_inv, b1_inv, b2_inv;
+    int k, hmax, max;
+    int xidx, yidx, yidx_max;
+    int even_odd_vert, even_odd_horiz, even_odd;
+    int invert_gradient2 = (bg[pat].type & 0x08);
+    int invert_column;
+    int ximage_rowbytes = ximage->bytes_per_line;
+    ulg i, row;
+    ulg pixel;
+/*---------------------------------------------------------------------------
+    Allocate buffer for fake background image to be used with transparent
+    images; if this fails, revert to plain background color.
+  ---------------------------------------------------------------------------*/
+    bg_rowbytes = 3 * rpng2_info.width;
+    bg_data = (uch *)malloc(bg_rowbytes * rpng2_info.height);
+    if (!bg_data) {
+        fprintf(stderr, PROGNAME
+          ":  unable to allocate memory for background image\n");
+        bg_image = 0;
+        return 1;
+    }
+    bgscale = (pat == 0)? 8 : bgscale_default;
+    yidx_max = bgscale - 1;
+/*---------------------------------------------------------------------------
+    Vertical gradients (ramps) in NxN squares, alternating direction and
+    colors (N == bgscale).
+  ---------------------------------------------------------------------------*/
+    if ((bg[pat].type & 0x07) == 0) {
+        uch r1_min  = rgb[bg[pat].rgb1_min].r;
+        uch g1_min  = rgb[bg[pat].rgb1_min].g;
+        uch b1_min  = rgb[bg[pat].rgb1_min].b;
+        uch r2_min  = rgb[bg[pat].rgb2_min].r;
+        uch g2_min  = rgb[bg[pat].rgb2_min].g;
+        uch b2_min  = rgb[bg[pat].rgb2_min].b;
+        int r1_diff = rgb[bg[pat].rgb1_max].r - r1_min;
+        int g1_diff = rgb[bg[pat].rgb1_max].g - g1_min;
+        int b1_diff = rgb[bg[pat].rgb1_max].b - b1_min;
+        int r2_diff = rgb[bg[pat].rgb2_max].r - r2_min;
+        int g2_diff = rgb[bg[pat].rgb2_max].g - g2_min;
+        int b2_diff = rgb[bg[pat].rgb2_max].b - b2_min;
+        for (row = 0;  row < rpng2_info.height;  ++row) {
+            yidx = (int)(row % bgscale);
+            even_odd_vert = (int)((row / bgscale) & 1);
+            r1 = r1_min + (r1_diff * yidx) / yidx_max;
+            g1 = g1_min + (g1_diff * yidx) / yidx_max;
+            b1 = b1_min + (b1_diff * yidx) / yidx_max;
+            r1_inv = r1_min + (r1_diff * (yidx_max-yidx)) / yidx_max;
+            g1_inv = g1_min + (g1_diff * (yidx_max-yidx)) / yidx_max;
+            b1_inv = b1_min + (b1_diff * (yidx_max-yidx)) / yidx_max;
+            r2 = r2_min + (r2_diff * yidx) / yidx_max;
+            g2 = g2_min + (g2_diff * yidx) / yidx_max;
+            b2 = b2_min + (b2_diff * yidx) / yidx_max;
+            r2_inv = r2_min + (r2_diff * (yidx_max-yidx)) / yidx_max;
+            g2_inv = g2_min + (g2_diff * (yidx_max-yidx)) / yidx_max;
+            b2_inv = b2_min + (b2_diff * (yidx_max-yidx)) / yidx_max;
+            dest = (char *)bg_data + row*bg_rowbytes;
+            for (i = 0;  i < rpng2_info.width;  ++i) {
+                even_odd_horiz = (int)((i / bgscale) & 1);
+                even_odd = even_odd_vert ^ even_odd_horiz;
+                invert_column =
+                  (even_odd_horiz && (bg[pat].type & 0x10));
+                if (even_odd == 0) {        /* gradient #1 */
+                    if (invert_column) {
+                        *dest++ = r1_inv;
+                        *dest++ = g1_inv;
+                        *dest++ = b1_inv;
+                    } else {
+                        *dest++ = r1;
+                        *dest++ = g1;
+                        *dest++ = b1;
+                    }
+                } else {                    /* gradient #2 */
+                    if ((invert_column && invert_gradient2) ||
+                        (!invert_column && !invert_gradient2))
+                    {
+                        *dest++ = r2;       /* not inverted or */
+                        *dest++ = g2;       /*  doubly inverted */
+                        *dest++ = b2;
+                    } else {
+                        *dest++ = r2_inv;
+                        *dest++ = g2_inv;   /* singly inverted */
+                        *dest++ = b2_inv;
+                    }
+                }
+            }
+        }
+/*---------------------------------------------------------------------------
+    Soft gradient-diamonds with scale = bgscale.  Code contributed by Adam
+    M. Costello.
+  ---------------------------------------------------------------------------*/
+    } else if ((bg[pat].type & 0x07) == 1) {
+        hmax = (bgscale-1)/2;   /* half the max weight of a color */
+        max = 2*hmax;           /* the max weight of a color */
+        r1 = rgb[bg[pat].rgb1_max].r;
+        g1 = rgb[bg[pat].rgb1_max].g;
+        b1 = rgb[bg[pat].rgb1_max].b;
+        r2 = rgb[bg[pat].rgb2_max].r;
+        g2 = rgb[bg[pat].rgb2_max].g;
+        b2 = rgb[bg[pat].rgb2_max].b;
+        for (row = 0;  row < rpng2_info.height;  ++row) {
+            yidx = (int)(row % bgscale);
+            if (yidx > hmax)
+                yidx = bgscale-1 - yidx;
+            dest = (char *)bg_data + row*bg_rowbytes;
+            for (i = 0;  i < rpng2_info.width;  ++i) {
+                xidx = (int)(i % bgscale);
+                if (xidx > hmax)
+                    xidx = bgscale-1 - xidx;
+                k = xidx + yidx;
+                *dest++ = (k*r1 + (max-k)*r2) / max;
+                *dest++ = (k*g1 + (max-k)*g2) / max;
+                *dest++ = (k*b1 + (max-k)*b2) / max;
+            }
+        }
+/*---------------------------------------------------------------------------
+    Radial "starburst" with azimuthal sinusoids; [eventually number of sinu-
+    soids will equal bgscale?].  This one is slow but very cool.  Code con-
+    tributed by Pieter S. van der Meulen (originally in Smalltalk).
+  ---------------------------------------------------------------------------*/
+    } else if ((bg[pat].type & 0x07) == 2) {
+        uch ch;
+        int ii, x, y, hw, hh, grayspot;
+        double freq, rotate, saturate, gray, intensity;
+        double angle=0.0, aoffset=0.0, maxDist, dist;
+        double red=0.0, green=0.0, blue=0.0, hue, s, v, f, p, q, t;
+        fprintf(stderr, "%s:  computing radial background...",
+          PROGNAME);
+        fflush(stderr);
+        hh = (int)(rpng2_info.height / 2);
+        hw = (int)(rpng2_info.width / 2);
+        /* variables for radial waves:
+         *   aoffset:  number of degrees to rotate hue [CURRENTLY NOT USED]
+         *   freq:  number of color beams originating from the center
+         *   grayspot:  size of the graying center area (anti-alias)
+         *   rotate:  rotation of the beams as a function of radius
+         *   saturate:  saturation of beams' shape azimuthally
+         */
+        angle = CLIP(angle, 0.0, 360.0);
+        grayspot = CLIP(bg[pat].bg_gray, 1, (hh + hw));
+        freq = MAX((double)bg[pat].bg_freq, 0.0);
+        saturate = (double)bg[pat].bg_bsat * 0.1;
+        rotate = (double)bg[pat].bg_brot * 0.1;
+        gray = 0.0;
+        intensity = 0.0;
+        maxDist = (double)((hw*hw) + (hh*hh));
+        for (row = 0;  row < rpng2_info.height;  ++row) {
+            y = (int)(row - hh);
+            dest = (char *)bg_data + row*bg_rowbytes;
+            for (i = 0;  i < rpng2_info.width;  ++i) {
+                x = (int)(i - hw);
+                angle = (x == 0)? PI_2 : atan((double)y / (double)x);
+                gray = (double)MAX(ABS(y), ABS(x)) / grayspot;
+                gray = MIN(1.0, gray);
+                dist = (double)((x*x) + (y*y)) / maxDist;
+                intensity = cos((angle+(rotate*dist*PI)) * freq) *
+                  gray * saturate;
+                intensity = (MAX(MIN(intensity,1.0),-1.0) + 1.0) * 0.5;
+                hue = (angle + PI) * INV_PI_360 + aoffset;
+                s = gray * ((double)(ABS(x)+ABS(y)) / (double)(hw + hh));
+                s = MIN(MAX(s,0.0), 1.0);
+                v = MIN(MAX(intensity,0.0), 1.0);
+                if (s == 0.0) {
+                    ch = (uch)(v * 255.0);
+                    *dest++ = ch;
+                    *dest++ = ch;
+                    *dest++ = ch;
+                } else {
+                    if ((hue < 0.0) || (hue >= 360.0))
+                        hue -= (((int)(hue / 360.0)) * 360.0);
+                    hue /= 60.0;
+                    ii = (int)hue;
+                    f = hue - (double)ii;
+                    p = (1.0 - s) * v;
+                    q = (1.0 - (s * f)) * v;
+                    t = (1.0 - (s * (1.0 - f))) * v;
+                    if      (ii == 0) { red = v; green = t; blue = p; }
+                    else if (ii == 1) { red = q; green = v; blue = p; }
+                    else if (ii == 2) { red = p; green = v; blue = t; }
+                    else if (ii == 3) { red = p; green = q; blue = v; }
+                    else if (ii == 4) { red = t; green = p; blue = v; }
+                    else if (ii == 5) { red = v; green = p; blue = q; }
+                    *dest++ = (uch)(red * 255.0);
+                    *dest++ = (uch)(green * 255.0);
+                    *dest++ = (uch)(blue * 255.0);
+                }
+            }
+        }
+        fprintf(stderr, "done.\n");
+        fflush(stderr);
+    }
+/*---------------------------------------------------------------------------
+    Blast background image to display buffer before beginning PNG decode.
+  ---------------------------------------------------------------------------*/
+    if (depth == 24 || depth == 32) {
+        ulg red, green, blue;
+        int bpp = ximage->bits_per_pixel;
+        for (row = 0;  row < rpng2_info.height;  ++row) {
+            src = bg_data + row*bg_rowbytes;
+            dest = ximage->data + row*ximage_rowbytes;
+            if (bpp == 32) {    /* slightly optimized version */
+                for (i = rpng2_info.width;  i > 0;  --i) {
+                    red   = *src++;
+                    green = *src++;
+                    blue  = *src++;
+                    pixel = (red   << RShift) |
+                            (green << GShift) |
+                            (blue  << BShift);
+                    /* recall that we set ximage->byte_order = MSBFirst above */
+                    *dest++ = (char)((pixel >> 24) & 0xff);
+                    *dest++ = (char)((pixel >> 16) & 0xff);
+                    *dest++ = (char)((pixel >>  8) & 0xff);
+                    *dest++ = (char)( pixel        & 0xff);
+                }
+            } else {
+                for (i = rpng2_info.width;  i > 0;  --i) {
+                    red   = *src++;
+                    green = *src++;
+                    blue  = *src++;
+                    pixel = (red   << RShift) |
+                            (green << GShift) |
+                            (blue  << BShift);
+                    /* recall that we set ximage->byte_order = MSBFirst above */
+                    /* GRR BUG?  this assumes bpp == 24 & bits are packed low */
+                    /*           (probably need to use RShift, RMask, etc.) */
+                    *dest++ = (char)((pixel >> 16) & 0xff);
+                    *dest++ = (char)((pixel >>  8) & 0xff);
+                    *dest++ = (char)( pixel        & 0xff);
+                }
+            }
+        }
+    } else if (depth == 16) {
+        ush red, green, blue;
+        for (row = 0;  row < rpng2_info.height;  ++row) {
+            src = bg_data + row*bg_rowbytes;
+            dest = ximage->data + row*ximage_rowbytes;
+            for (i = rpng2_info.width;  i > 0;  --i) {
+                red   = ((ush)(*src) << 8);  ++src;
+                green = ((ush)(*src) << 8);  ++src;
+                blue  = ((ush)(*src) << 8);  ++src;
+                pixel = ((red   >> RShift) & RMask) |
+                        ((green >> GShift) & GMask) |
+                        ((blue  >> BShift) & BMask);
+                /* recall that we set ximage->byte_order = MSBFirst above */
+                *dest++ = (char)((pixel >>  8) & 0xff);
+                *dest++ = (char)( pixel        & 0xff);
+            }
+        }
+    } else /* depth == 8 */ {
+        /* GRR:  add 8-bit support */
+    }
+    XPutImage(display, window, gc, ximage, 0, 0, 0, 0, rpng2_info.width,
+      rpng2_info.height);
+    return 0;
+} /* end function rpng2_x_load_bg_image() */
+static void rpng2_x_display_row(ulg row)
+{
+    uch bg_red   = rpng2_info.bg_red;
+    uch bg_green = rpng2_info.bg_green;
+    uch bg_blue  = rpng2_info.bg_blue;
+    uch *src, *src2=NULL;
+    char *dest;
+    uch r, g, b, a;
+    int ximage_rowbytes = ximage->bytes_per_line;
+    ulg i, pixel;
+    static int rows=0, prevpass=(-1);
+    static ulg firstrow;
+/*---------------------------------------------------------------------------
+    rows and firstrow simply track how many rows (and which ones) have not
+    yet been displayed; alternatively, we could call XPutImage() for every
+    row and not bother with the records-keeping.
+  ---------------------------------------------------------------------------*/
+    Trace((stderr, "beginning rpng2_x_display_row()\n"))
+    if (rpng2_info.pass != prevpass) {
+        if (pause_after_pass && rpng2_info.pass > 0) {
+            XEvent e;
+            KeySym k;
+            fprintf(stderr,
+              "%s:  end of pass %d of 7; click in image window to continue\n",
+              PROGNAME, prevpass + 1);
+            do
+                XNextEvent(display, &e);
+            while (!QUIT(e,k));
+        }
+        fprintf(stderr, "%s:  pass %d of 7\r", PROGNAME, rpng2_info.pass + 1);
+        fflush(stderr);
+        prevpass = rpng2_info.pass;
+    }
+    if (rows == 0)
+        firstrow = row;   /* first row that is not yet displayed */
+    ++rows;   /* count of rows received but not yet displayed */
+/*---------------------------------------------------------------------------
+    Aside from the use of the rpng2_info struct, the lack of an outer loop
+    (over rows) and moving the XPutImage() call outside the "if (depth)"
+    tests, this routine is identical to rpng_x_display_image() in the non-
+    progressive version of the program.
+  ---------------------------------------------------------------------------*/
+    if (depth == 24 || depth == 32) {
+        ulg red, green, blue;
+        int bpp = ximage->bits_per_pixel;
+        src = rpng2_info.image_data + row*rpng2_info.rowbytes;
+        if (bg_image)
+            src2 = bg_data + row*bg_rowbytes;
+        dest = ximage->data + row*ximage_rowbytes;
+        if (rpng2_info.channels == 3) {
+            for (i = rpng2_info.width;  i > 0;  --i) {
+                red   = *src++;
+                green = *src++;
+                blue  = *src++;
+                pixel = (red   << RShift) |
+                        (green << GShift) |
+                        (blue  << BShift);
+                /* recall that we set ximage->byte_order = MSBFirst above */
+                if (bpp == 32) {
+                    *dest++ = (char)((pixel >> 24) & 0xff);
+                    *dest++ = (char)((pixel >> 16) & 0xff);
+                    *dest++ = (char)((pixel >>  8) & 0xff);
+                    *dest++ = (char)( pixel        & 0xff);
+                } else {
+                    /* GRR BUG?  this assumes bpp == 24 & bits are packed low */
+                    /*           (probably need to use RShift, RMask, etc.) */
+                    *dest++ = (char)((pixel >> 16) & 0xff);
+                    *dest++ = (char)((pixel >>  8) & 0xff);
+                    *dest++ = (char)( pixel        & 0xff);
+                }
+            }
+        } else /* if (rpng2_info.channels == 4) */ {
+            for (i = rpng2_info.width;  i > 0;  --i) {
+                r = *src++;
+                g = *src++;
+                b = *src++;
+                a = *src++;
+                if (bg_image) {
+                    bg_red   = *src2++;
+                    bg_green = *src2++;
+                    bg_blue  = *src2++;
+                }
+                if (a == 255) {
+                    red   = r;
+                    green = g;
+                    blue  = b;
+                } else if (a == 0) {
+                    red   = bg_red;
+                    green = bg_green;
+                    blue  = bg_blue;
+                } else {
+                    /* this macro (from png.h) composites the foreground
+                     * and background values and puts the result into the
+                     * first argument */
+                    alpha_composite(red,   r, a, bg_red);
+                    alpha_composite(green, g, a, bg_green);
+                    alpha_composite(blue,  b, a, bg_blue);
+                }
+                pixel = (red   << RShift) |
+                        (green << GShift) |
+                        (blue  << BShift);
+                /* recall that we set ximage->byte_order = MSBFirst above */
+                if (bpp == 32) {
+                    *dest++ = (char)((pixel >> 24) & 0xff);
+                    *dest++ = (char)((pixel >> 16) & 0xff);
+                    *dest++ = (char)((pixel >>  8) & 0xff);
+                    *dest++ = (char)( pixel        & 0xff);
+                } else {
+                    /* GRR BUG?  this assumes bpp == 24 & bits are packed low */
+                    /*           (probably need to use RShift, RMask, etc.) */
+                    *dest++ = (char)((pixel >> 16) & 0xff);
+                    *dest++ = (char)((pixel >>  8) & 0xff);
+                    *dest++ = (char)( pixel        & 0xff);
+                }
+            }
+        }
+    } else if (depth == 16) {
+        ush red, green, blue;
+        src = rpng2_info.row_pointers[row];
+        if (bg_image)
+            src2 = bg_data + row*bg_rowbytes;
+        dest = ximage->data + row*ximage_rowbytes;
+        if (rpng2_info.channels == 3) {
+            for (i = rpng2_info.width;  i > 0;  --i) {
+                red   = ((ush)(*src) << 8);
+                ++src;
+                green = ((ush)(*src) << 8);
+                ++src;
+                blue  = ((ush)(*src) << 8);
+                ++src;
+                pixel = ((red   >> RShift) & RMask) |
+                        ((green >> GShift) & GMask) |
+                        ((blue  >> BShift) & BMask);
+                /* recall that we set ximage->byte_order = MSBFirst above */
+                *dest++ = (char)((pixel >>  8) & 0xff);
+                *dest++ = (char)( pixel        & 0xff);
+            }
+        } else /* if (rpng2_info.channels == 4) */ {
+            for (i = rpng2_info.width;  i > 0;  --i) {
+                r = *src++;
+                g = *src++;
+                b = *src++;
+                a = *src++;
+                if (bg_image) {
+                    bg_red   = *src2++;
+                    bg_green = *src2++;
+                    bg_blue  = *src2++;
+                }
+                if (a == 255) {
+                    red   = ((ush)r << 8);
+                    green = ((ush)g << 8);
+                    blue  = ((ush)b << 8);
+                } else if (a == 0) {
+                    red   = ((ush)bg_red   << 8);
+                    green = ((ush)bg_green << 8);
+                    blue  = ((ush)bg_blue  << 8);
+                } else {
+                    /* this macro (from png.h) composites the foreground
+                     * and background values and puts the result back into
+                     * the first argument (== fg byte here:  safe) */
+                    alpha_composite(r, r, a, bg_red);
+                    alpha_composite(g, g, a, bg_green);
+                    alpha_composite(b, b, a, bg_blue);
+                    red   = ((ush)r << 8);
+                    green = ((ush)g << 8);
+                    blue  = ((ush)b << 8);
+                }
+                pixel = ((red   >> RShift) & RMask) |
+                        ((green >> GShift) & GMask) |
+                        ((blue  >> BShift) & BMask);
+                /* recall that we set ximage->byte_order = MSBFirst above */
+                *dest++ = (char)((pixel >>  8) & 0xff);
+                *dest++ = (char)( pixel        & 0xff);
+            }
+        }
+    } else /* depth == 8 */ {
+        /* GRR:  add 8-bit support */
+    }
+/*---------------------------------------------------------------------------
+    Display after every 16 rows or when on one of last two rows.  (Region
+    may include previously displayed lines due to interlacing--i.e., not
+    contiguous.  Also, second-to-last row is final one in interlaced images
+    with odd number of rows.)  For demos, flush (and delay) after every 16th
+    row so "sparse" passes don't go twice as fast.
+  ---------------------------------------------------------------------------*/
+    if (demo_timing && (row - firstrow >= 16 || row >= rpng2_info.height-2)) {
+        XPutImage(display, window, gc, ximage, 0, (int)firstrow, 0,
+          (int)firstrow, rpng2_info.width, row - firstrow + 1);
+        XFlush(display);
+        rows = 0;
+        usleep(usleep_duration);
+    } else
+    if (!demo_timing && ((rows & 0xf) == 0 || row >= rpng2_info.height-2)) {
+        XPutImage(display, window, gc, ximage, 0, (int)firstrow, 0,
+          (int)firstrow, rpng2_info.width, row - firstrow + 1);
+        XFlush(display);
+        rows = 0;
+    }
+}
+static void rpng2_x_finish_display(void)
+{
+    Trace((stderr, "beginning rpng2_x_finish_display()\n"))
+    /* last row has already been displayed by rpng2_x_display_row(), so we
+     * have nothing to do here except set a flag and let the user know that
+     * the image is done */
+    rpng2_info.state = kDone;
+    printf(
+      "Done.  Press Q, Esc or mouse button 1 (within image window) to quit.\n");
+    fflush(stdout);
+}
+static void rpng2_x_redisplay_image(ulg startcol, ulg startrow,
+                                    ulg width, ulg height)
+{
+    uch bg_red   = rpng2_info.bg_red;
+    uch bg_green = rpng2_info.bg_green;
+    uch bg_blue  = rpng2_info.bg_blue;
+    uch *src, *src2=NULL;
+    char *dest;
+    uch r, g, b, a;
+    ulg i, row, lastrow = 0;
+    ulg pixel;
+    int ximage_rowbytes = ximage->bytes_per_line;
+    Trace((stderr, "beginning display loop (image_channels == %d)\n",
+      rpng2_info.channels))
+    Trace((stderr, "   (width = %ld, rowbytes = %d, ximage_rowbytes = %d)\n",
+      rpng2_info.width, rpng2_info.rowbytes, ximage_rowbytes))
+    Trace((stderr, "   (bpp = %d)\n", ximage->bits_per_pixel))
+    Trace((stderr, "   (byte_order = %s)\n", ximage->byte_order == MSBFirst?
+      "MSBFirst" : (ximage->byte_order == LSBFirst? "LSBFirst" : "unknown")))
+/*---------------------------------------------------------------------------
+    Aside from the use of the rpng2_info struct and of src2 (for background
+    image), this routine is identical to rpng_x_display_image() in the non-
+    progressive version of the program--for the simple reason that redisplay
+    of the image against a new background happens after the image is fully
+    decoded and therefore is, by definition, non-progressive.
+  ---------------------------------------------------------------------------*/
+    if (depth == 24 || depth == 32) {
+        ulg red, green, blue;
+        int bpp = ximage->bits_per_pixel;
+        for (lastrow = row = startrow;  row < startrow+height;  ++row) {
+            src = rpng2_info.image_data + row*rpng2_info.rowbytes;
+            if (bg_image)
+                src2 = bg_data + row*bg_rowbytes;
+            dest = ximage->data + row*ximage_rowbytes;
+            if (rpng2_info.channels == 3) {
+                for (i = rpng2_info.width;  i > 0;  --i) {
+                    red   = *src++;
+                    green = *src++;
+                    blue  = *src++;
+#ifdef NO_24BIT_MASKS
+                    pixel = (red   << RShift) |
+                            (green << GShift) |
+                            (blue  << BShift);
+                    /* recall that we set ximage->byte_order = MSBFirst above */
+                    if (bpp == 32) {
+                        *dest++ = (char)((pixel >> 24) & 0xff);
+                        *dest++ = (char)((pixel >> 16) & 0xff);
+                        *dest++ = (char)((pixel >>  8) & 0xff);
+                        *dest++ = (char)( pixel        & 0xff);
+                    } else {
+                        /* this assumes bpp == 24 & bits are packed low */
+                        /* (probably need to use RShift, RMask, etc.) */
+                        *dest++ = (char)((pixel >> 16) & 0xff);
+                        *dest++ = (char)((pixel >>  8) & 0xff);
+                        *dest++ = (char)( pixel        & 0xff);
+                    }
+#else
+                    red   = (RShift < 0)? red   << (-RShift) : red   >> RShift;
+                    green = (GShift < 0)? green << (-GShift) : green >> GShift;
+                    blue  = (BShift < 0)? blue  << (-BShift) : blue  >> BShift;
+                    pixel = (red & RMask) | (green & GMask) | (blue & BMask);
+                    /* recall that we set ximage->byte_order = MSBFirst above */
+                    if (bpp == 32) {
+                        *dest++ = (char)((pixel >> 24) & 0xff);
+                        *dest++ = (char)((pixel >> 16) & 0xff);
+                        *dest++ = (char)((pixel >>  8) & 0xff);
+                        *dest++ = (char)( pixel        & 0xff);
+                    } else {
+                        /* GRR BUG */
+                        /* this assumes bpp == 24 & bits are packed low */
+                        /* (probably need to use RShift/RMask/etc. here, too) */
+                        *dest++ = (char)((pixel >> 16) & 0xff);
+                        *dest++ = (char)((pixel >>  8) & 0xff);
+                        *dest++ = (char)( pixel        & 0xff);
+                    }
+#endif
+                }
+            } else /* if (rpng2_info.channels == 4) */ {
+                for (i = rpng2_info.width;  i > 0;  --i) {
+                    r = *src++;
+                    g = *src++;
+                    b = *src++;
+                    a = *src++;
+                    if (bg_image) {
+                        bg_red   = *src2++;
+                        bg_green = *src2++;
+                        bg_blue  = *src2++;
+                    }
+                    if (a == 255) {
+                        red   = r;
+                        green = g;
+                        blue  = b;
+                    } else if (a == 0) {
+                        red   = bg_red;
+                        green = bg_green;
+                        blue  = bg_blue;
+                    } else {
+                        /* this macro (from png.h) composites the foreground
+                         * and background values and puts the result into the
+                         * first argument */
+                        alpha_composite(red,   r, a, bg_red);
+                        alpha_composite(green, g, a, bg_green);
+                        alpha_composite(blue,  b, a, bg_blue);
+                    }
+#ifdef NO_24BIT_MASKS
+                    pixel = (red   << RShift) |
+                            (green << GShift) |
+                            (blue  << BShift);
+                    /* recall that we set ximage->byte_order = MSBFirst above */
+                    if (bpp == 32) {
+                        *dest++ = (char)((pixel >> 24) & 0xff);
+                        *dest++ = (char)((pixel >> 16) & 0xff);
+                        *dest++ = (char)((pixel >>  8) & 0xff);
+                        *dest++ = (char)( pixel        & 0xff);
+                    } else {
+                        /* this assumes bpp == 24 & bits are packed low */
+                        /* (probably need to use RShift, RMask, etc.) */
+                        *dest++ = (char)((pixel >> 16) & 0xff);
+                        *dest++ = (char)((pixel >>  8) & 0xff);
+                        *dest++ = (char)( pixel        & 0xff);
+                    }
+#else
+                    red   = (RShift < 0)? red   << (-RShift) : red   >> RShift;
+                    green = (GShift < 0)? green << (-GShift) : green >> GShift;
+                    blue  = (BShift < 0)? blue  << (-BShift) : blue  >> BShift;
+                    pixel = (red & RMask) | (green & GMask) | (blue & BMask);
+                    /* recall that we set ximage->byte_order = MSBFirst above */
+                    if (bpp == 32) {
+                        *dest++ = (char)((pixel >> 24) & 0xff);
+                        *dest++ = (char)((pixel >> 16) & 0xff);
+                        *dest++ = (char)((pixel >>  8) & 0xff);
+                        *dest++ = (char)( pixel        & 0xff);
+                    } else {
+                        /* GRR BUG */
+                        /* this assumes bpp == 24 & bits are packed low */
+                        /* (probably need to use RShift/RMask/etc. here, too) */
+                        *dest++ = (char)((pixel >> 16) & 0xff);
+                        *dest++ = (char)((pixel >>  8) & 0xff);
+                        *dest++ = (char)( pixel        & 0xff);
+                    }
+#endif
+                }
+            }
+            /* display after every 16 lines */
+            if (((row+1) & 0xf) == 0) {
+                XPutImage(display, window, gc, ximage, 0, (int)lastrow, 0,
+                  (int)lastrow, rpng2_info.width, 16);
+                XFlush(display);
+                lastrow = row + 1;
+            }
+        }
+    } else if (depth == 16) {
+        ush red, green, blue;
+        for (lastrow = row = startrow;  row < startrow+height;  ++row) {
+            src = rpng2_info.row_pointers[row];
+            if (bg_image)
+                src2 = bg_data + row*bg_rowbytes;
+            dest = ximage->data + row*ximage_rowbytes;
+            if (rpng2_info.channels == 3) {
+                for (i = rpng2_info.width;  i > 0;  --i) {
+                    red   = ((ush)(*src) << 8);
+                    ++src;
+                    green = ((ush)(*src) << 8);
+                    ++src;
+                    blue  = ((ush)(*src) << 8);
+                    ++src;
+                    pixel = ((red   >> RShift) & RMask) |
+                            ((green >> GShift) & GMask) |
+                            ((blue  >> BShift) & BMask);
+                    /* recall that we set ximage->byte_order = MSBFirst above */
+                    *dest++ = (char)((pixel >>  8) & 0xff);
+                    *dest++ = (char)( pixel        & 0xff);
+                }
+            } else /* if (rpng2_info.channels == 4) */ {
+                for (i = rpng2_info.width;  i > 0;  --i) {
+                    r = *src++;
+                    g = *src++;
+                    b = *src++;
+                    a = *src++;
+                    if (bg_image) {
+                        bg_red   = *src2++;
+                        bg_green = *src2++;
+                        bg_blue  = *src2++;
+                    }
+                    if (a == 255) {
+                        red   = ((ush)r << 8);
+                        green = ((ush)g << 8);
+                        blue  = ((ush)b << 8);
+                    } else if (a == 0) {
+                        red   = ((ush)bg_red   << 8);
+                        green = ((ush)bg_green << 8);
+                        blue  = ((ush)bg_blue  << 8);
+                    } else {
+                        /* this macro (from png.h) composites the foreground
+                         * and background values and puts the result back into
+                         * the first argument (== fg byte here:  safe) */
+                        alpha_composite(r, r, a, bg_red);
+                        alpha_composite(g, g, a, bg_green);
+                        alpha_composite(b, b, a, bg_blue);
+                        red   = ((ush)r << 8);
+                        green = ((ush)g << 8);
+                        blue  = ((ush)b << 8);
+                    }
+                    pixel = ((red   >> RShift) & RMask) |
+                            ((green >> GShift) & GMask) |
+                            ((blue  >> BShift) & BMask);
+                    /* recall that we set ximage->byte_order = MSBFirst above */
+                    *dest++ = (char)((pixel >>  8) & 0xff);
+                    *dest++ = (char)( pixel        & 0xff);
+                }
+            }
+            /* display after every 16 lines */
+            if (((row+1) & 0xf) == 0) {
+                XPutImage(display, window, gc, ximage, 0, (int)lastrow, 0,
+                  (int)lastrow, rpng2_info.width, 16);
+                XFlush(display);
+                lastrow = row + 1;
+            }
+        }
+    } else /* depth == 8 */ {
+        /* GRR:  add 8-bit support */
+    }
+    Trace((stderr, "calling final XPutImage()\n"))
+    if (lastrow < startrow+height) {
+        XPutImage(display, window, gc, ximage, 0, (int)lastrow, 0,
+          (int)lastrow, rpng2_info.width, rpng2_info.height-lastrow);
+        XFlush(display);
+    }
+} /* end function rpng2_x_redisplay_image() */
+#ifdef FEATURE_LOOP
+static void rpng2_x_reload_bg_image(void)
+{
+    char *dest;
+    uch r1, r2, g1, g2, b1, b2;
+    uch r1_inv, r2_inv, g1_inv, g2_inv, b1_inv, b2_inv;
+    int k, hmax, max;
+    int xidx, yidx, yidx_max;
+    int even_odd_vert, even_odd_horiz, even_odd;
+    int invert_gradient2 = (bg[pat].type & 0x08);
+    int invert_column;
+    ulg i, row;
+    bgscale = (pat == 0)? 8 : bgscale_default;
+    yidx_max = bgscale - 1;
+/*---------------------------------------------------------------------------
+    Vertical gradients (ramps) in NxN squares, alternating direction and
+    colors (N == bgscale).
+  ---------------------------------------------------------------------------*/
+    if ((bg[pat].type & 0x07) == 0) {
+        uch r1_min  = rgb[bg[pat].rgb1_min].r;
+        uch g1_min  = rgb[bg[pat].rgb1_min].g;
+        uch b1_min  = rgb[bg[pat].rgb1_min].b;
+        uch r2_min  = rgb[bg[pat].rgb2_min].r;
+        uch g2_min  = rgb[bg[pat].rgb2_min].g;
+        uch b2_min  = rgb[bg[pat].rgb2_min].b;
+        int r1_diff = rgb[bg[pat].rgb1_max].r - r1_min;
+        int g1_diff = rgb[bg[pat].rgb1_max].g - g1_min;
+        int b1_diff = rgb[bg[pat].rgb1_max].b - b1_min;
+        int r2_diff = rgb[bg[pat].rgb2_max].r - r2_min;
+        int g2_diff = rgb[bg[pat].rgb2_max].g - g2_min;
+        int b2_diff = rgb[bg[pat].rgb2_max].b - b2_min;
+        for (row = 0;  row < rpng2_info.height;  ++row) {
+            yidx = (int)(row % bgscale);
+            even_odd_vert = (int)((row / bgscale) & 1);
+            r1 = r1_min + (r1_diff * yidx) / yidx_max;
+            g1 = g1_min + (g1_diff * yidx) / yidx_max;
+            b1 = b1_min + (b1_diff * yidx) / yidx_max;
+            r1_inv = r1_min + (r1_diff * (yidx_max-yidx)) / yidx_max;
+            g1_inv = g1_min + (g1_diff * (yidx_max-yidx)) / yidx_max;
+            b1_inv = b1_min + (b1_diff * (yidx_max-yidx)) / yidx_max;
+            r2 = r2_min + (r2_diff * yidx) / yidx_max;
+            g2 = g2_min + (g2_diff * yidx) / yidx_max;
+            b2 = b2_min + (b2_diff * yidx) / yidx_max;
+            r2_inv = r2_min + (r2_diff * (yidx_max-yidx)) / yidx_max;
+            g2_inv = g2_min + (g2_diff * (yidx_max-yidx)) / yidx_max;
+            b2_inv = b2_min + (b2_diff * (yidx_max-yidx)) / yidx_max;
+            dest = (char *)bg_data + row*bg_rowbytes;
+            for (i = 0;  i < rpng2_info.width;  ++i) {
+                even_odd_horiz = (int)((i / bgscale) & 1);
+                even_odd = even_odd_vert ^ even_odd_horiz;
+                invert_column =
+                  (even_odd_horiz && (bg[pat].type & 0x10));
+                if (even_odd == 0) {        /* gradient #1 */
+                    if (invert_column) {
+                        *dest++ = r1_inv;
+                        *dest++ = g1_inv;
+                        *dest++ = b1_inv;
+                    } else {
+                        *dest++ = r1;
+                        *dest++ = g1;
+                        *dest++ = b1;
+                    }
+                } else {                    /* gradient #2 */
+                    if ((invert_column && invert_gradient2) ||
+                        (!invert_column && !invert_gradient2))
+                    {
+                        *dest++ = r2;       /* not inverted or */
+                        *dest++ = g2;       /*  doubly inverted */
+                        *dest++ = b2;
+                    } else {
+                        *dest++ = r2_inv;
+                        *dest++ = g2_inv;   /* singly inverted */
+                        *dest++ = b2_inv;
+                    }
+                }
+            }
+        }
+/*---------------------------------------------------------------------------
+    Soft gradient-diamonds with scale = bgscale.  Code contributed by Adam
+    M. Costello.
+  ---------------------------------------------------------------------------*/
+    } else if ((bg[pat].type & 0x07) == 1) {
+        hmax = (bgscale-1)/2;   /* half the max weight of a color */
+        max = 2*hmax;           /* the max weight of a color */
+        r1 = rgb[bg[pat].rgb1_max].r;
+        g1 = rgb[bg[pat].rgb1_max].g;
+        b1 = rgb[bg[pat].rgb1_max].b;
+        r2 = rgb[bg[pat].rgb2_max].r;
+        g2 = rgb[bg[pat].rgb2_max].g;
+        b2 = rgb[bg[pat].rgb2_max].b;
+        for (row = 0;  row < rpng2_info.height;  ++row) {
+            yidx = (int)(row % bgscale);
+            if (yidx > hmax)
+                yidx = bgscale-1 - yidx;
+            dest = (char *)bg_data + row*bg_rowbytes;
+            for (i = 0;  i < rpng2_info.width;  ++i) {
+                xidx = (int)(i % bgscale);
+                if (xidx > hmax)
+                    xidx = bgscale-1 - xidx;
+                k = xidx + yidx;
+                *dest++ = (k*r1 + (max-k)*r2) / max;
+                *dest++ = (k*g1 + (max-k)*g2) / max;
+                *dest++ = (k*b1 + (max-k)*b2) / max;
+            }
+        }
+/*---------------------------------------------------------------------------
+    Radial "starburst" with azimuthal sinusoids; [eventually number of sinu-
+    soids will equal bgscale?].  This one is slow but very cool.  Code con-
+    tributed by Pieter S. van der Meulen (originally in Smalltalk).
+  ---------------------------------------------------------------------------*/
+    } else if ((bg[pat].type & 0x07) == 2) {
+        uch ch;
+        int ii, x, y, hw, hh, grayspot;
+        double freq, rotate, saturate, gray, intensity;
+        double angle=0.0, aoffset=0.0, maxDist, dist;
+        double red=0.0, green=0.0, blue=0.0, hue, s, v, f, p, q, t;
+        hh = (int)(rpng2_info.height / 2);
+        hw = (int)(rpng2_info.width / 2);
+        /* variables for radial waves:
+         *   aoffset:  number of degrees to rotate hue [CURRENTLY NOT USED]
+         *   freq:  number of color beams originating from the center
+         *   grayspot:  size of the graying center area (anti-alias)
+         *   rotate:  rotation of the beams as a function of radius
+         *   saturate:  saturation of beams' shape azimuthally
+         */
+        angle = CLIP(angle, 0.0, 360.0);
+        grayspot = CLIP(bg[pat].bg_gray, 1, (hh + hw));
+        freq = MAX((double)bg[pat].bg_freq, 0.0);
+        saturate = (double)bg[pat].bg_bsat * 0.1;
+        rotate = (double)bg[pat].bg_brot * 0.1;
+        gray = 0.0;
+        intensity = 0.0;
+        maxDist = (double)((hw*hw) + (hh*hh));
+        for (row = 0;  row < rpng2_info.height;  ++row) {
+            y = (int)(row - hh);
+            dest = (char *)bg_data + row*bg_rowbytes;
+            for (i = 0;  i < rpng2_info.width;  ++i) {
+                x = (int)(i - hw);
+                angle = (x == 0)? PI_2 : atan((double)y / (double)x);
+                gray = (double)MAX(ABS(y), ABS(x)) / grayspot;
+                gray = MIN(1.0, gray);
+                dist = (double)((x*x) + (y*y)) / maxDist;
+                intensity = cos((angle+(rotate*dist*PI)) * freq) *
+                  gray * saturate;
+                intensity = (MAX(MIN(intensity,1.0),-1.0) + 1.0) * 0.5;
+                hue = (angle + PI) * INV_PI_360 + aoffset;
+                s = gray * ((double)(ABS(x)+ABS(y)) / (double)(hw + hh));
+                s = MIN(MAX(s,0.0), 1.0);
+                v = MIN(MAX(intensity,0.0), 1.0);
+                if (s == 0.0) {
+                    ch = (uch)(v * 255.0);
+                    *dest++ = ch;
+                    *dest++ = ch;
+                    *dest++ = ch;
+                } else {
+                    if ((hue < 0.0) || (hue >= 360.0))
+                        hue -= (((int)(hue / 360.0)) * 360.0);
+                    hue /= 60.0;
+                    ii = (int)hue;
+                    f = hue - (double)ii;
+                    p = (1.0 - s) * v;
+                    q = (1.0 - (s * f)) * v;
+                    t = (1.0 - (s * (1.0 - f))) * v;
+                    if      (ii == 0) { red = v; green = t; blue = p; }
+                    else if (ii == 1) { red = q; green = v; blue = p; }
+                    else if (ii == 2) { red = p; green = v; blue = t; }
+                    else if (ii == 3) { red = p; green = q; blue = v; }
+                    else if (ii == 4) { red = t; green = p; blue = v; }
+                    else if (ii == 5) { red = v; green = p; blue = q; }
+                    *dest++ = (uch)(red * 255.0);
+                    *dest++ = (uch)(green * 255.0);
+                    *dest++ = (uch)(blue * 255.0);
+                }
+            }
+        }
+    }
+} /* end function rpng2_x_reload_bg_image() */
+static int is_number(char *p)
+{
+    while (*p) {
+        if (!isdigit(*p))
+            return FALSE;
+        ++p;
+    }
+    return TRUE;
+}
+#endif /* FEATURE_LOOP */
+static void rpng2_x_cleanup(void)
+{
+    if (bg_image && bg_data) {
+        free(bg_data);
+        bg_data = NULL;
+    }
+    if (rpng2_info.image_data) {
+        free(rpng2_info.image_data);
+        rpng2_info.image_data = NULL;
+    }
+    if (rpng2_info.row_pointers) {
+        free(rpng2_info.row_pointers);
+        rpng2_info.row_pointers = NULL;
+    }
+    if (ximage) {
+        if (ximage->data) {
+            free(ximage->data);           /* we allocated it, so we free it */
+            ximage->data = (char *)NULL;  /*  instead of XDestroyImage() */
+        }
+        XDestroyImage(ximage);
+        ximage = NULL;
+    }
+    if (have_gc)
+        XFreeGC(display, gc);
+    if (have_window)
+        XDestroyWindow(display, window);
+    if (have_colormap)
+        XFreeColormap(display, colormap);
+    if (have_nondefault_visual)
+        XFree(visual_list);
+}
+static int rpng2_x_msb(ulg u32val)
+{
+    int i;
+    for (i = 31;  i >= 0;  --i) {
+        if (u32val & 0x80000000L)
+            break;
+        u32val <<= 1;
+    }
+    return i;
+}
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/toucan.png b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/toucan.png
new file mode 100644
index 0000000..03960d4
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/toucan.png
Binary files differ
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/wpng.c b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/wpng.c
new file mode 100644
index 0000000..30372a3
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/wpng.c
@@ -0,0 +1,853 @@
+/*---------------------------------------------------------------------------
+   wpng - simple PNG-writing program                                 wpng.c
+   This program converts certain NetPBM binary files (grayscale and RGB,
+   maxval = 255) to PNG.  Non-interlaced PNGs are written progressively;
+   interlaced PNGs are read and written in one memory-intensive blast.
+   Thanks to Jean-loup Gailly for providing the necessary trick to read
+   interactive text from the keyboard while stdin is redirected.  Thanks
+   to Cosmin Truta for Cygwin fixes.
+   NOTE:  includes provisional support for PNM type "8" (portable alphamap)
+          images, presumed to be a 32-bit interleaved RGBA format; no pro-
+          vision for possible interleaved grayscale+alpha (16-bit) format.
+          THIS IS UNLIKELY TO BECOME AN OFFICIAL NETPBM ALPHA FORMAT!
+   to do:
+    - delete output file if quit before calling any writepng routines
+    - process backspace with -text option under DOS/Win? (currently get ^H)
+  ---------------------------------------------------------------------------
+   Changelog:
+    - 1.01:  initial public release
+    - 1.02:  modified to allow abbreviated options
+    - 1.03:  removed extraneous character from usage screen; fixed bug in
+              command-line parsing
+    - 1.04:  fixed DOS/OS2/Win32 detection, including partial Cygwin fix
+              (see http://home.att.net/~perlspinr/diffs/GregBook_cygwin.diff)
+    - 2.00:  dual-licensed (added GNU GPL)
+        [REPORTED BUG (win32 only):  "contrib/gregbook/wpng.c - cmd line
+         dose not work!  In order to do something useful I needed to redirect
+         both input and output, with cygwin and with bcc32 as well.  Under
+         Linux, the same wpng appears to work fine.  I don't know what is
+         the problem."]
+  ---------------------------------------------------------------------------
+      Copyright (c) 1998-2007 Greg Roelofs.  All rights reserved.
+      This software is provided "as is," without warranty of any kind,
+      express or implied.  In no event shall the author or contributors
+      be held liable for any damages arising in any way from the use of
+      this software.
+      The contents of this file are DUAL-LICENSED.  You may modify and/or
+      redistribute this software according to the terms of one of the
+      following two licenses (at your option):
+      LICENSE 1 ("BSD-like with advertising clause"):
+      Permission is granted to anyone to use this software for any purpose,
+      including commercial applications, and to alter it and redistribute
+      it freely, subject to the following restrictions:
+      1. Redistributions of source code must retain the above copyright
+         notice, disclaimer, and this list of conditions.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, disclaimer, and this list of conditions in the documenta-
+         tion and/or other materials provided with the distribution.
+      3. All advertising materials mentioning features or use of this
+         software must display the following acknowledgment:
+            This product includes software developed by Greg Roelofs
+            and contributors for the book, "PNG: The Definitive Guide,"
+            published by O'Reilly and Associates.
+      LICENSE 2 (GNU GPL v2 or later):
+      This program is free software; you can redistribute it and/or modify
+      it under the terms of the GNU General Public License as published by
+      the Free Software Foundation; either version 2 of the License, or
+      (at your option) any later version.
+      This program is distributed in the hope that it will be useful,
+      but WITHOUT ANY WARRANTY; without even the implied warranty of
+      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+      GNU General Public License for more details.
+      You should have received a copy of the GNU General Public License
+      along with this program; if not, write to the Free Software Foundation,
+      Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+  ---------------------------------------------------------------------------*/
+#define PROGNAME  "wpng"
+#define VERSION   "2.00 of 2 June 2007"
+#define APPNAME   "Simple PGM/PPM/PAM to PNG Converter"
+#if defined(__MSDOS__) || defined(__OS2__)
+#  define DOS_OS2_W32
+#elif defined(WIN32) || defined(_WIN32) || defined(__WIN32__)
+#  ifndef __GNUC__   /* treat Win32 native ports of gcc as Unix environments */
+#    define DOS_OS2_W32
+#  endif
+#endif
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <setjmp.h>     /* for jmpbuf declaration in writepng.h */
+#include <time.h>
+#ifdef DOS_OS2_W32
+#  include <io.h>       /* for isatty(), setmode() prototypes */
+#  include <fcntl.h>    /* O_BINARY for fdopen() without text translation */
+#  ifdef __EMX__
+#    ifndef getch
+#      define getch() _read_kbd(0, 1, 0)    /* need getche() */
+#    endif
+#  else /* !__EMX__ */
+#    ifdef __GO32__
+#      include <pc.h>
+#      define getch() getkey()  /* GRR:  need getche() */
+#    else
+#      include <conio.h>        /* for getche() console input */
+#    endif
+#  endif /* ?__EMX__ */
+#  define FGETS(buf,len,stream)  dos_kbd_gets(buf,len)
+#else
+#  include <unistd.h>           /* for isatty() prototype */
+#  define FGETS fgets
+#endif
+/* #define DEBUG  :  this enables the Trace() macros */
+/* #define FORBID_LATIN1_CTRL  :  this requires the user to re-enter any
+   text that includes control characters discouraged by the PNG spec; text
+   that includes an escape character (27) must be re-entered regardless */
+#include "writepng.h"   /* typedefs, common macros, writepng prototypes */
+/* local prototypes */
+static int  wpng_isvalid_latin1(uch *p, int len);
+static void wpng_cleanup(void);
+#ifdef DOS_OS2_W32
+   static char *dos_kbd_gets(char *buf, int len);
+#endif
+static mainprog_info wpng_info;   /* lone global */
+int main(int argc, char **argv)
+{
+#ifndef DOS_OS2_W32
+    FILE *keybd;
+#endif
+#ifdef sgi
+    FILE *tmpfile;      /* or we could just use keybd, since no overlap */
+    char tmpline[80];
+#endif
+    char *inname = NULL, outname[256];
+    char *p, pnmchar, pnmline[256];
+    char *bgstr, *textbuf = NULL;
+    ulg rowbytes;
+    int rc, len = 0;
+    int error = 0;
+    int text = FALSE;
+    int maxval;
+    double LUT_exponent;                /* just the lookup table */
+    double CRT_exponent = 2.2;          /* just the monitor */
+    double default_display_exponent;    /* whole display system */
+    double default_gamma = 0.0;
+    wpng_info.infile = NULL;
+    wpng_info.outfile = NULL;
+    wpng_info.image_data = NULL;
+    wpng_info.row_pointers = NULL;
+    wpng_info.filter = FALSE;
+    wpng_info.interlaced = FALSE;
+    wpng_info.have_bg = FALSE;
+    wpng_info.have_time = FALSE;
+    wpng_info.have_text = 0;
+    wpng_info.gamma = 0.0;
+    /* First get the default value for our display-system exponent, i.e.,
+     * the product of the CRT exponent and the exponent corresponding to
+     * the frame-buffer's lookup table (LUT), if any.  If the PNM image
+     * looks correct on the user's display system, its file gamma is the
+     * inverse of this value.  (Note that this is not an exhaustive list
+     * of LUT values--e.g., OpenStep has a lot of weird ones--but it should
+     * cover 99% of the current possibilities.  This section must ensure
+     * that default_display_exponent is positive.) */
+#if defined(NeXT)
+    /* third-party utilities can modify the default LUT exponent */
+    LUT_exponent = 1.0 / 2.2;
+    /*
+    if (some_next_function_that_returns_gamma(&next_gamma))
+        LUT_exponent = 1.0 / next_gamma;
+     */
+#elif defined(sgi)
+    LUT_exponent = 1.0 / 1.7;
+    /* there doesn't seem to be any documented function to
+     * get the "gamma" value, so we do it the hard way */
+    tmpfile = fopen("/etc/config/system.glGammaVal", "r");
+    if (tmpfile) {
+        double sgi_gamma;
+        fgets(tmpline, 80, tmpfile);
+        fclose(tmpfile);
+        sgi_gamma = atof(tmpline);
+        if (sgi_gamma > 0.0)
+            LUT_exponent = 1.0 / sgi_gamma;
+    }
+#elif defined(Macintosh)
+    LUT_exponent = 1.8 / 2.61;
+    /*
+    if (some_mac_function_that_returns_gamma(&mac_gamma))
+        LUT_exponent = mac_gamma / 2.61;
+     */
+#else
+    LUT_exponent = 1.0;   /* assume no LUT:  most PCs */
+#endif
+    /* the defaults above give 1.0, 1.3, 1.5 and 2.2, respectively: */
+    default_display_exponent = LUT_exponent * CRT_exponent;
+    /* If the user has set the SCREEN_GAMMA environment variable as suggested
+     * (somewhat imprecisely) in the libpng documentation, use that; otherwise
+     * use the default value we just calculated.  Either way, the user may
+     * override this via a command-line option. */
+    if ((p = getenv("SCREEN_GAMMA")) != NULL) {
+        double exponent = atof(p);
+        if (exponent > 0.0)
+            default_gamma = 1.0 / exponent;
+    }
+    if (default_gamma == 0.0)
+        default_gamma = 1.0 / default_display_exponent;
+    /* Now parse the command line for options and the PNM filename. */
+    while (*++argv && !error) {
+        if (!strncmp(*argv, "-i", 2)) {
+            wpng_info.interlaced = TRUE;
+        } else if (!strncmp(*argv, "-time", 3)) {
+            wpng_info.modtime = time(NULL);
+            wpng_info.have_time = TRUE;
+        } else if (!strncmp(*argv, "-text", 3)) {
+            text = TRUE;
+        } else if (!strncmp(*argv, "-gamma", 2)) {
+            if (!*++argv)
+                ++error;
+            else {
+                wpng_info.gamma = atof(*argv);
+                if (wpng_info.gamma <= 0.0)
+                    ++error;
+                else if (wpng_info.gamma > 1.01)
+                    fprintf(stderr, PROGNAME
+                      " warning:  file gammas are usually less than 1.0\n");
+            }
+        } else if (!strncmp(*argv, "-bgcolor", 4)) {
+            if (!*++argv)
+                ++error;
+            else {
+                bgstr = *argv;
+                if (strlen(bgstr) != 7 || bgstr[0] != '#')
+                    ++error;
+                else {
+                    unsigned r, g, b;  /* this way quiets compiler warnings */
+                    sscanf(bgstr+1, "%2x%2x%2x", &r, &g, &b);
+                    wpng_info.bg_red   = (uch)r;
+                    wpng_info.bg_green = (uch)g;
+                    wpng_info.bg_blue  = (uch)b;
+                    wpng_info.have_bg = TRUE;
+                }
+            }
+        } else {
+            if (**argv != '-') {
+                inname = *argv;
+                if (argv[1])   /* shouldn't be any more args after filename */
+                    ++error;
+            } else
+                ++error;   /* not expecting any other options */
+        }
+    }
+    /* open the input and output files, or register an error and abort */
+    if (!inname) {
+        if (isatty(0)) {
+            fprintf(stderr, PROGNAME
+              ":  must give input filename or provide image data via stdin\n");
+            ++error;
+        } else {
+#ifdef DOS_OS2_W32
+            /* some buggy C libraries require BOTH setmode() and fdopen(bin) */
+            setmode(fileno(stdin), O_BINARY);
+            setmode(fileno(stdout), O_BINARY);
+#endif
+            if ((wpng_info.infile = fdopen(fileno(stdin), "rb")) == NULL) {
+                fprintf(stderr, PROGNAME
+                  ":  unable to reopen stdin in binary mode\n");
+                ++error;
+            } else
+            if ((wpng_info.outfile = fdopen(fileno(stdout), "wb")) == NULL) {
+                fprintf(stderr, PROGNAME
+                  ":  unable to reopen stdout in binary mode\n");
+                fclose(wpng_info.infile);
+                ++error;
+            } else
+                wpng_info.filter = TRUE;
+        }
+    } else if ((len = strlen(inname)) > 250) {
+        fprintf(stderr, PROGNAME ":  input filename is too long [%d chars]\n",
+          len);
+        ++error;
+    } else if (!(wpng_info.infile = fopen(inname, "rb"))) {
+        fprintf(stderr, PROGNAME ":  can't open input file [%s]\n", inname);
+        ++error;
+    }
+    if (!error) {
+        fgets(pnmline, 256, wpng_info.infile);
+        if (pnmline[0] != 'P' || ((pnmchar = pnmline[1]) != '5' &&
+            pnmchar != '6' && pnmchar != '8'))
+        {
+            fprintf(stderr, PROGNAME
+              ":  input file [%s] is not a binary PGM, PPM or PAM file\n",
+              inname);
+            ++error;
+        } else {
+            wpng_info.pnmtype = (int)(pnmchar - '0');
+            if (wpng_info.pnmtype != 8)
+                wpng_info.have_bg = FALSE;  /* no need for bg if opaque */
+            do {
+                fgets(pnmline, 256, wpng_info.infile);  /* lose any comments */
+            } while (pnmline[0] == '#');
+            sscanf(pnmline, "%ld %ld", &wpng_info.width, &wpng_info.height);
+            do {
+                fgets(pnmline, 256, wpng_info.infile);  /* more comment lines */
+            } while (pnmline[0] == '#');
+            sscanf(pnmline, "%d", &maxval);
+            if (wpng_info.width <= 0L || wpng_info.height <= 0L ||
+                maxval != 255)
+            {
+                fprintf(stderr, PROGNAME
+                  ":  only positive width/height, maxval == 255 allowed \n");
+                ++error;
+            }
+            wpng_info.sample_depth = 8;  /* <==> maxval 255 */
+            if (!wpng_info.filter) {
+                /* make outname from inname */
+                if ((p = strrchr(inname, '.')) == NULL ||
+                    (p - inname) != (len - 4))
+                {
+                    strcpy(outname, inname);
+                    strcpy(outname+len, ".png");
+                } else {
+                    len -= 4;
+                    strncpy(outname, inname, len);
+                    strcpy(outname+len, ".png");
+                }
+                /* check if outname already exists; if not, open */
+                if ((wpng_info.outfile = fopen(outname, "rb")) != NULL) {
+                    fprintf(stderr, PROGNAME ":  output file exists [%s]\n",
+                      outname);
+                    fclose(wpng_info.outfile);
+                    ++error;
+                } else if (!(wpng_info.outfile = fopen(outname, "wb"))) {
+                    fprintf(stderr, PROGNAME ":  can't open output file [%s]\n",
+                      outname);
+                    ++error;
+                }
+            }
+        }
+        if (error) {
+            fclose(wpng_info.infile);
+            wpng_info.infile = NULL;
+            if (wpng_info.filter) {
+                fclose(wpng_info.outfile);
+                wpng_info.outfile = NULL;
+            }
+        }
+    }
+    /* if we had any errors, print usage and die horrible death...arrr! */
+    if (error) {
+        fprintf(stderr, "\n%s %s:  %s\n", PROGNAME, VERSION, APPNAME);
+        writepng_version_info();
+        fprintf(stderr, "\n"
+"Usage:  %s [-gamma exp] [-bgcolor bg] [-text] [-time] [-interlace] pnmfile\n"
+"or: ... | %s [-gamma exp] [-bgcolor bg] [-text] [-time] [-interlace] | ...\n"
+         "    exp \ttransfer-function exponent (``gamma'') of the image in\n"
+         "\t\t  floating-point format (e.g., ``%.5f''); if image looks\n"
+         "\t\t  correct on given display system, image gamma is equal to\n"
+         "\t\t  inverse of display-system exponent, i.e., 1 / (LUT * CRT)\n"
+         "\t\t  (where LUT = lookup-table exponent and CRT = CRT exponent;\n"
+         "\t\t  first varies, second is usually 2.2, all are positive)\n"
+         "    bg  \tdesired background color for alpha-channel images, in\n"
+         "\t\t  7-character hex RGB format (e.g., ``#ff7700'' for orange:\n"
+         "\t\t  same as HTML colors)\n"
+         "    -text\tprompt interactively for text info (tEXt chunks)\n"
+         "    -time\tinclude a tIME chunk (last modification time)\n"
+         "    -interlace\twrite interlaced PNG image\n"
+         "\n"
+"pnmfile or stdin must be a binary PGM (`P5'), PPM (`P6') or (extremely\n"
+"unofficial and unsupported!) PAM (`P8') file.  Currently it is required\n"
+"to have maxval == 255 (i.e., no scaling).  If pnmfile is specified, it\n"
+"is converted to the corresponding PNG file with the same base name but a\n"
+"``.png'' extension; files read from stdin are converted and sent to stdout.\n"
+"The conversion is progressive (low memory usage) unless interlacing is\n"
+"requested; in that case the whole image will be buffered in memory and\n"
+"written in one call.\n"
+         "\n", PROGNAME, PROGNAME, default_gamma);
+        exit(1);
+    }
+    /* prepare the text buffers for libpng's use; note that even though
+     * PNG's png_text struct includes a length field, we don't have to fill
+     * it out */
+    if (text &&
+#ifndef DOS_OS2_W32
+        (keybd = fdopen(fileno(stderr), "r")) != NULL &&
+#endif
+        (textbuf = (char *)malloc((5 + 9)*75)) != NULL)
+    {
+        int i, valid, result;
+        fprintf(stderr,
+          "Enter text info (no more than 72 characters per line);\n");
+        fprintf(stderr, "to skip a field, hit the <Enter> key.\n");
+        /* note:  just <Enter> leaves len == 1 */
+        do {
+            valid = TRUE;
+            p = textbuf + TEXT_TITLE_OFFSET;
+            fprintf(stderr, "  Title: ");
+            fflush(stderr);
+            if (FGETS(p, 74, keybd) && (len = strlen(p)) > 1) {
+                if (p[len-1] == '\n')
+                    p[--len] = '\0';
+                wpng_info.title = p;
+                wpng_info.have_text |= TEXT_TITLE;
+                if ((result = wpng_isvalid_latin1((uch *)p, len)) >= 0) {
+                    fprintf(stderr, "    " PROGNAME " warning:  character code"
+                      " %u is %sdiscouraged by the PNG\n    specification "
+                      "[first occurrence was at character position #%d]\n",
+                      (unsigned)p[result], (p[result] == 27)? "strongly " : "",
+                      result+1);
+                    fflush(stderr);
+#ifdef FORBID_LATIN1_CTRL
+                    wpng_info.have_text &= ~TEXT_TITLE;
+                    valid = FALSE;
+#else
+                    if (p[result] == 27) {    /* escape character */
+                        wpng_info.have_text &= ~TEXT_TITLE;
+                        valid = FALSE;
+                    }
+#endif
+                }
+            }
+        } while (!valid);
+        do {
+            valid = TRUE;
+            p = textbuf + TEXT_AUTHOR_OFFSET;
+            fprintf(stderr, "  Author: ");
+            fflush(stderr);
+            if (FGETS(p, 74, keybd) && (len = strlen(p)) > 1) {
+                if (p[len-1] == '\n')
+                    p[--len] = '\0';
+                wpng_info.author = p;
+                wpng_info.have_text |= TEXT_AUTHOR;
+                if ((result = wpng_isvalid_latin1((uch *)p, len)) >= 0) {
+                    fprintf(stderr, "    " PROGNAME " warning:  character code"
+                      " %u is %sdiscouraged by the PNG\n    specification "
+                      "[first occurrence was at character position #%d]\n",
+                      (unsigned)p[result], (p[result] == 27)? "strongly " : "",
+                      result+1);
+                    fflush(stderr);
+#ifdef FORBID_LATIN1_CTRL
+                    wpng_info.have_text &= ~TEXT_AUTHOR;
+                    valid = FALSE;
+#else
+                    if (p[result] == 27) {    /* escape character */
+                        wpng_info.have_text &= ~TEXT_AUTHOR;
+                        valid = FALSE;
+                    }
+#endif
+                }
+            }
+        } while (!valid);
+        do {
+            valid = TRUE;
+            p = textbuf + TEXT_DESC_OFFSET;
+            fprintf(stderr, "  Description (up to 9 lines):\n");
+            for (i = 1;  i < 10;  ++i) {
+                fprintf(stderr, "    [%d] ", i);
+                fflush(stderr);
+                if (FGETS(p, 74, keybd) && (len = strlen(p)) > 1)
+                    p += len;   /* now points at NULL; char before is newline */
+                else
+                    break;
+            }
+            if ((len = p - (textbuf + TEXT_DESC_OFFSET)) > 1) {
+                if (p[-1] == '\n') {
+                    p[-1] = '\0';
+                    --len;
+                }
+                wpng_info.desc = textbuf + TEXT_DESC_OFFSET;
+                wpng_info.have_text |= TEXT_DESC;
+                p = textbuf + TEXT_DESC_OFFSET;
+                if ((result = wpng_isvalid_latin1((uch *)p, len)) >= 0) {
+                    fprintf(stderr, "    " PROGNAME " warning:  character code"
+                      " %u is %sdiscouraged by the PNG\n    specification "
+                      "[first occurrence was at character position #%d]\n",
+                      (unsigned)p[result], (p[result] == 27)? "strongly " : "",
+                      result+1);
+                    fflush(stderr);
+#ifdef FORBID_LATIN1_CTRL
+                    wpng_info.have_text &= ~TEXT_DESC;
+                    valid = FALSE;
+#else
+                    if (p[result] == 27) {    /* escape character */
+                        wpng_info.have_text &= ~TEXT_DESC;
+                        valid = FALSE;
+                    }
+#endif
+                }
+            }
+        } while (!valid);
+        do {
+            valid = TRUE;
+            p = textbuf + TEXT_COPY_OFFSET;
+            fprintf(stderr, "  Copyright: ");
+            fflush(stderr);
+            if (FGETS(p, 74, keybd) && (len = strlen(p)) > 1) {
+                if (p[len-1] == '\n')
+                    p[--len] = '\0';
+                wpng_info.copyright = p;
+                wpng_info.have_text |= TEXT_COPY;
+                if ((result = wpng_isvalid_latin1((uch *)p, len)) >= 0) {
+                    fprintf(stderr, "    " PROGNAME " warning:  character code"
+                      " %u is %sdiscouraged by the PNG\n    specification "
+                      "[first occurrence was at character position #%d]\n",
+                      (unsigned)p[result], (p[result] == 27)? "strongly " : "",
+                      result+1);
+                    fflush(stderr);
+#ifdef FORBID_LATIN1_CTRL
+                    wpng_info.have_text &= ~TEXT_COPY;
+                    valid = FALSE;
+#else
+                    if (p[result] == 27) {    /* escape character */
+                        wpng_info.have_text &= ~TEXT_COPY;
+                        valid = FALSE;
+                    }
+#endif
+                }
+            }
+        } while (!valid);
+        do {
+            valid = TRUE;
+            p = textbuf + TEXT_EMAIL_OFFSET;
+            fprintf(stderr, "  E-mail: ");
+            fflush(stderr);
+            if (FGETS(p, 74, keybd) && (len = strlen(p)) > 1) {
+                if (p[len-1] == '\n')
+                    p[--len] = '\0';
+                wpng_info.email = p;
+                wpng_info.have_text |= TEXT_EMAIL;
+                if ((result = wpng_isvalid_latin1((uch *)p, len)) >= 0) {
+                    fprintf(stderr, "    " PROGNAME " warning:  character code"
+                      " %u is %sdiscouraged by the PNG\n    specification "
+                      "[first occurrence was at character position #%d]\n",
+                      (unsigned)p[result], (p[result] == 27)? "strongly " : "",
+                      result+1);
+                    fflush(stderr);
+#ifdef FORBID_LATIN1_CTRL
+                    wpng_info.have_text &= ~TEXT_EMAIL;
+                    valid = FALSE;
+#else
+                    if (p[result] == 27) {    /* escape character */
+                        wpng_info.have_text &= ~TEXT_EMAIL;
+                        valid = FALSE;
+                    }
+#endif
+                }
+            }
+        } while (!valid);
+        do {
+            valid = TRUE;
+            p = textbuf + TEXT_URL_OFFSET;
+            fprintf(stderr, "  URL: ");
+            fflush(stderr);
+            if (FGETS(p, 74, keybd) && (len = strlen(p)) > 1) {
+                if (p[len-1] == '\n')
+                    p[--len] = '\0';
+                wpng_info.url = p;
+                wpng_info.have_text |= TEXT_URL;
+                if ((result = wpng_isvalid_latin1((uch *)p, len)) >= 0) {
+                    fprintf(stderr, "    " PROGNAME " warning:  character code"
+                      " %u is %sdiscouraged by the PNG\n    specification "
+                      "[first occurrence was at character position #%d]\n",
+                      (unsigned)p[result], (p[result] == 27)? "strongly " : "",
+                      result+1);
+                    fflush(stderr);
+#ifdef FORBID_LATIN1_CTRL
+                    wpng_info.have_text &= ~TEXT_URL;
+                    valid = FALSE;
+#else
+                    if (p[result] == 27) {    /* escape character */
+                        wpng_info.have_text &= ~TEXT_URL;
+                        valid = FALSE;
+                    }
+#endif
+                }
+            }
+        } while (!valid);
+#ifndef DOS_OS2_W32
+        fclose(keybd);
+#endif
+    } else if (text) {
+        fprintf(stderr, PROGNAME ":  unable to allocate memory for text\n");
+        text = FALSE;
+        wpng_info.have_text = 0;
+    }
+    /* allocate libpng stuff, initialize transformations, write pre-IDAT data */
+    if ((rc = writepng_init(&wpng_info)) != 0) {
+        switch (rc) {
+            case 2:
+                fprintf(stderr, PROGNAME
+                  ":  libpng initialization problem (longjmp)\n");
+                break;
+            case 4:
+                fprintf(stderr, PROGNAME ":  insufficient memory\n");
+                break;
+            case 11:
+                fprintf(stderr, PROGNAME
+                  ":  internal logic error (unexpected PNM type)\n");
+                break;
+            default:
+                fprintf(stderr, PROGNAME
+                  ":  unknown writepng_init() error\n");
+                break;
+        }
+        exit(rc);
+    }
+    /* free textbuf, since it's a completely local variable and all text info
+     * has just been written to the PNG file */
+    if (text && textbuf) {
+        free(textbuf);
+        textbuf = NULL;
+    }
+    /* calculate rowbytes on basis of image type; note that this becomes much
+     * more complicated if we choose to support PBM type, ASCII PNM types, or
+     * 16-bit-per-sample binary data [currently not an official NetPBM type] */
+    if (wpng_info.pnmtype == 5)
+        rowbytes = wpng_info.width;
+    else if (wpng_info.pnmtype == 6)
+        rowbytes = wpng_info.width * 3;
+    else /* if (wpng_info.pnmtype == 8) */
+        rowbytes = wpng_info.width * 4;
+    /* read and write the image, either in its entirety (if writing interlaced
+     * PNG) or row by row (if non-interlaced) */
+    fprintf(stderr, "Encoding image data...\n");
+    fflush(stderr);
+    if (wpng_info.interlaced) {
+        long i;
+        ulg bytes;
+        ulg image_bytes = rowbytes * wpng_info.height;   /* overflow? */
+        wpng_info.image_data = (uch *)malloc(image_bytes);
+        wpng_info.row_pointers = (uch **)malloc(wpng_info.height*sizeof(uch *));
+        if (wpng_info.image_data == NULL || wpng_info.row_pointers == NULL) {
+            fprintf(stderr, PROGNAME ":  insufficient memory for image data\n");
+            writepng_cleanup(&wpng_info);
+            wpng_cleanup();
+            exit(5);
+        }
+        for (i = 0;  i < wpng_info.height;  ++i)
+            wpng_info.row_pointers[i] = wpng_info.image_data + i*rowbytes;
+        bytes = fread(wpng_info.image_data, 1, image_bytes, wpng_info.infile);
+        if (bytes != image_bytes) {
+            fprintf(stderr, PROGNAME ":  expected %lu bytes, got %lu bytes\n",
+              image_bytes, bytes);
+            fprintf(stderr, "  (continuing anyway)\n");
+        }
+        if (writepng_encode_image(&wpng_info) != 0) {
+            fprintf(stderr, PROGNAME
+              ":  libpng problem (longjmp) while writing image data\n");
+            writepng_cleanup(&wpng_info);
+            wpng_cleanup();
+            exit(2);
+        }
+    } else /* not interlaced:  write progressively (row by row) */ {
+        long j;
+        ulg bytes;
+        wpng_info.image_data = (uch *)malloc(rowbytes);
+        if (wpng_info.image_data == NULL) {
+            fprintf(stderr, PROGNAME ":  insufficient memory for row data\n");
+            writepng_cleanup(&wpng_info);
+            wpng_cleanup();
+            exit(5);
+        }
+        error = 0;
+        for (j = wpng_info.height;  j > 0L;  --j) {
+            bytes = fread(wpng_info.image_data, 1, rowbytes, wpng_info.infile);
+            if (bytes != rowbytes) {
+                fprintf(stderr, PROGNAME
+                  ":  expected %lu bytes, got %lu bytes (row %ld)\n", rowbytes,
+                  bytes, wpng_info.height-j);
+                ++error;
+                break;
+            }
+            if (writepng_encode_row(&wpng_info) != 0) {
+                fprintf(stderr, PROGNAME
+                  ":  libpng problem (longjmp) while writing row %ld\n",
+                  wpng_info.height-j);
+                ++error;
+                break;
+            }
+        }
+        if (error) {
+            writepng_cleanup(&wpng_info);
+            wpng_cleanup();
+            exit(2);
+        }
+        if (writepng_encode_finish(&wpng_info) != 0) {
+            fprintf(stderr, PROGNAME ":  error on final libpng call\n");
+            writepng_cleanup(&wpng_info);
+            wpng_cleanup();
+            exit(2);
+        }
+    }
+    /* OK, we're done (successfully):  clean up all resources and quit */
+    fprintf(stderr, "Done.\n");
+    fflush(stderr);
+    writepng_cleanup(&wpng_info);
+    wpng_cleanup();
+    return 0;
+}
+static int wpng_isvalid_latin1(uch *p, int len)
+{
+    int i, result = -1;
+    for (i = 0;  i < len;  ++i) {
+        if (p[i] == 10 || (p[i] > 31 && p[i] < 127) || p[i] > 160)
+            continue;           /* character is completely OK */
+        if (result < 0 || (p[result] != 27 && p[i] == 27))
+            result = i;         /* mark location of first questionable one */
+    }                           /*  or of first escape character (bad) */
+    return result;
+}
+static void wpng_cleanup(void)
+{
+    if (wpng_info.outfile) {
+        fclose(wpng_info.outfile);
+        wpng_info.outfile = NULL;
+    }
+    if (wpng_info.infile) {
+        fclose(wpng_info.infile);
+        wpng_info.infile = NULL;
+    }
+    if (wpng_info.image_data) {
+        free(wpng_info.image_data);
+        wpng_info.image_data = NULL;
+    }
+    if (wpng_info.row_pointers) {
+        free(wpng_info.row_pointers);
+        wpng_info.row_pointers = NULL;
+    }
+}
+#ifdef DOS_OS2_W32
+static char *dos_kbd_gets(char *buf, int len)
+{
+    int ch, count=0;
+    do {
+        buf[count++] = ch = getche();
+    } while (ch != '\r' && count < len-1);
+    buf[count--] = '\0';        /* terminate string */
+    if (buf[count] == '\r')     /* Enter key makes CR, so change to newline */
+        buf[count] = '\n';
+    fprintf(stderr, "\n");      /* Enter key does *not* cause a newline */
+    fflush(stderr);
+    return buf;
+}
+#endif /* DOS_OS2_W32 */
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/writepng.c b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/writepng.c
new file mode 100644
index 0000000..8373c16
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/writepng.c
@@ -0,0 +1,400 @@
+/*---------------------------------------------------------------------------
+   wpng - simple PNG-writing program                             writepng.c
+  ---------------------------------------------------------------------------
+      Copyright (c) 1998-2007 Greg Roelofs.  All rights reserved.
+      This software is provided "as is," without warranty of any kind,
+      express or implied.  In no event shall the author or contributors
+      be held liable for any damages arising in any way from the use of
+      this software.
+      The contents of this file are DUAL-LICENSED.  You may modify and/or
+      redistribute this software according to the terms of one of the
+      following two licenses (at your option):
+      LICENSE 1 ("BSD-like with advertising clause"):
+      Permission is granted to anyone to use this software for any purpose,
+      including commercial applications, and to alter it and redistribute
+      it freely, subject to the following restrictions:
+      1. Redistributions of source code must retain the above copyright
+         notice, disclaimer, and this list of conditions.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, disclaimer, and this list of conditions in the documenta-
+         tion and/or other materials provided with the distribution.
+      3. All advertising materials mentioning features or use of this
+         software must display the following acknowledgment:
+            This product includes software developed by Greg Roelofs
+            and contributors for the book, "PNG: The Definitive Guide,"
+            published by O'Reilly and Associates.
+      LICENSE 2 (GNU GPL v2 or later):
+      This program is free software; you can redistribute it and/or modify
+      it under the terms of the GNU General Public License as published by
+      the Free Software Foundation; either version 2 of the License, or
+      (at your option) any later version.
+      This program is distributed in the hope that it will be useful,
+      but WITHOUT ANY WARRANTY; without even the implied warranty of
+      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+      GNU General Public License for more details.
+      You should have received a copy of the GNU General Public License
+      along with this program; if not, write to the Free Software Foundation,
+      Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+  ---------------------------------------------------------------------------*/
+#include <stdlib.h>     /* for exit() prototype */
+#include "png.h"        /* libpng header; includes zlib.h and setjmp.h */
+#include "writepng.h"   /* typedefs, common macros, public prototypes */
+/* local prototype */
+static void writepng_error_handler(png_structp png_ptr, png_const_charp msg);
+void writepng_version_info(void)
+{
+  fprintf(stderr, "   Compiled with libpng %s; using libpng %s.\n",
+    PNG_LIBPNG_VER_STRING, png_libpng_ver);
+  fprintf(stderr, "   Compiled with zlib %s; using zlib %s.\n",
+    ZLIB_VERSION, zlib_version);
+}
+/* returns 0 for success, 2 for libpng problem, 4 for out of memory, 11 for
+ *  unexpected pnmtype; note that outfile might be stdout */
+int writepng_init(mainprog_info *mainprog_ptr)
+{
+    png_structp  png_ptr;       /* note:  temporary variables! */
+    png_infop  info_ptr;
+    int color_type, interlace_type;
+    /* could also replace libpng warning-handler (final NULL), but no need: */
+    png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, mainprog_ptr,
+      writepng_error_handler, NULL);
+    if (!png_ptr)
+        return 4;   /* out of memory */
+    info_ptr = png_create_info_struct(png_ptr);
+    if (!info_ptr) {
+        png_destroy_write_struct(&png_ptr, NULL);
+        return 4;   /* out of memory */
+    }
+    /* setjmp() must be called in every function that calls a PNG-writing
+     * libpng function, unless an alternate error handler was installed--
+     * but compatible error handlers must either use longjmp() themselves
+     * (as in this program) or some other method to return control to
+     * application code, so here we go: */
+    if (setjmp(mainprog_ptr->jmpbuf)) {
+        png_destroy_write_struct(&png_ptr, &info_ptr);
+        return 2;
+    }
+    /* make sure outfile is (re)opened in BINARY mode */
+    png_init_io(png_ptr, mainprog_ptr->outfile);
+    /* set the compression levels--in general, always want to leave filtering
+     * turned on (except for palette images) and allow all of the filters,
+     * which is the default; want 32K zlib window, unless entire image buffer
+     * is 16K or smaller (unknown here)--also the default; usually want max
+     * compression (NOT the default); and remaining compression flags should
+     * be left alone */
+    png_set_compression_level(png_ptr, Z_BEST_COMPRESSION);
+/*
+    >> this is default for no filtering; Z_FILTERED is default otherwise:
+    png_set_compression_strategy(png_ptr, Z_DEFAULT_STRATEGY);
+    >> these are all defaults:
+    png_set_compression_mem_level(png_ptr, 8);
+    png_set_compression_window_bits(png_ptr, 15);
+    png_set_compression_method(png_ptr, 8);
+ */
+    /* set the image parameters appropriately */
+    if (mainprog_ptr->pnmtype == 5)
+        color_type = PNG_COLOR_TYPE_GRAY;
+    else if (mainprog_ptr->pnmtype == 6)
+        color_type = PNG_COLOR_TYPE_RGB;
+    else if (mainprog_ptr->pnmtype == 8)
+        color_type = PNG_COLOR_TYPE_RGB_ALPHA;
+    else {
+        png_destroy_write_struct(&png_ptr, &info_ptr);
+        return 11;
+    }
+    interlace_type = mainprog_ptr->interlaced? PNG_INTERLACE_ADAM7 :
+                                               PNG_INTERLACE_NONE;
+    png_set_IHDR(png_ptr, info_ptr, mainprog_ptr->width, mainprog_ptr->height,
+      mainprog_ptr->sample_depth, color_type, interlace_type,
+      PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
+    if (mainprog_ptr->gamma > 0.0)
+        png_set_gAMA(png_ptr, info_ptr, mainprog_ptr->gamma);
+    if (mainprog_ptr->have_bg) {   /* we know it's RGBA, not gray+alpha */
+        png_color_16  background;
+        background.red = mainprog_ptr->bg_red;
+        background.green = mainprog_ptr->bg_green;
+        background.blue = mainprog_ptr->bg_blue;
+        png_set_bKGD(png_ptr, info_ptr, &background);
+    }
+    if (mainprog_ptr->have_time) {
+        png_time  modtime;
+        png_convert_from_time_t(&modtime, mainprog_ptr->modtime);
+        png_set_tIME(png_ptr, info_ptr, &modtime);
+    }
+    if (mainprog_ptr->have_text) {
+        png_text  text[6];
+        int  num_text = 0;
+        if (mainprog_ptr->have_text & TEXT_TITLE) {
+            text[num_text].compression = PNG_TEXT_COMPRESSION_NONE;
+            text[num_text].key = "Title";
+            text[num_text].text = mainprog_ptr->title;
+            ++num_text;
+        }
+        if (mainprog_ptr->have_text & TEXT_AUTHOR) {
+            text[num_text].compression = PNG_TEXT_COMPRESSION_NONE;
+            text[num_text].key = "Author";
+            text[num_text].text = mainprog_ptr->author;
+            ++num_text;
+        }
+        if (mainprog_ptr->have_text & TEXT_DESC) {
+            text[num_text].compression = PNG_TEXT_COMPRESSION_NONE;
+            text[num_text].key = "Description";
+            text[num_text].text = mainprog_ptr->desc;
+            ++num_text;
+        }
+        if (mainprog_ptr->have_text & TEXT_COPY) {
+            text[num_text].compression = PNG_TEXT_COMPRESSION_NONE;
+            text[num_text].key = "Copyright";
+            text[num_text].text = mainprog_ptr->copyright;
+            ++num_text;
+        }
+        if (mainprog_ptr->have_text & TEXT_EMAIL) {
+            text[num_text].compression = PNG_TEXT_COMPRESSION_NONE;
+            text[num_text].key = "E-mail";
+            text[num_text].text = mainprog_ptr->email;
+            ++num_text;
+        }
+        if (mainprog_ptr->have_text & TEXT_URL) {
+            text[num_text].compression = PNG_TEXT_COMPRESSION_NONE;
+            text[num_text].key = "URL";
+            text[num_text].text = mainprog_ptr->url;
+            ++num_text;
+        }
+        png_set_text(png_ptr, info_ptr, text, num_text);
+    }
+    /* write all chunks up to (but not including) first IDAT */
+    png_write_info(png_ptr, info_ptr);
+    /* if we wanted to write any more text info *after* the image data, we
+     * would set up text struct(s) here and call png_set_text() again, with
+     * just the new data; png_set_tIME() could also go here, but it would
+     * have no effect since we already called it above (only one tIME chunk
+     * allowed) */
+    /* set up the transformations:  for now, just pack low-bit-depth pixels
+     * into bytes (one, two or four pixels per byte) */
+    png_set_packing(png_ptr);
+/*  png_set_shift(png_ptr, &sig_bit);  to scale low-bit-depth values */
+    /* make sure we save our pointers for use in writepng_encode_image() */
+    mainprog_ptr->png_ptr = png_ptr;
+    mainprog_ptr->info_ptr = info_ptr;
+    /* OK, that's all we need to do for now; return happy */
+    return 0;
+}
+/* returns 0 for success, 2 for libpng (longjmp) problem */
+int writepng_encode_image(mainprog_info *mainprog_ptr)
+{
+    png_structp png_ptr = (png_structp)mainprog_ptr->png_ptr;
+    png_infop info_ptr = (png_infop)mainprog_ptr->info_ptr;
+    /* as always, setjmp() must be called in every function that calls a
+     * PNG-writing libpng function */
+    if (setjmp(mainprog_ptr->jmpbuf)) {
+        png_destroy_write_struct(&png_ptr, &info_ptr);
+        mainprog_ptr->png_ptr = NULL;
+        mainprog_ptr->info_ptr = NULL;
+        return 2;
+    }
+    /* and now we just write the whole image; libpng takes care of interlacing
+     * for us */
+    png_write_image(png_ptr, mainprog_ptr->row_pointers);
+    /* since that's it, we also close out the end of the PNG file now--if we
+     * had any text or time info to write after the IDATs, second argument
+     * would be info_ptr, but we optimize slightly by sending NULL pointer: */
+    png_write_end(png_ptr, NULL);
+    return 0;
+}
+/* returns 0 if succeeds, 2 if libpng problem */
+int writepng_encode_row(mainprog_info *mainprog_ptr)  /* NON-interlaced only! */
+{
+    png_structp png_ptr = (png_structp)mainprog_ptr->png_ptr;
+    png_infop info_ptr = (png_infop)mainprog_ptr->info_ptr;
+    /* as always, setjmp() must be called in every function that calls a
+     * PNG-writing libpng function */
+    if (setjmp(mainprog_ptr->jmpbuf)) {
+        png_destroy_write_struct(&png_ptr, &info_ptr);
+        mainprog_ptr->png_ptr = NULL;
+        mainprog_ptr->info_ptr = NULL;
+        return 2;
+    }
+    /* image_data points at our one row of image data */
+    png_write_row(png_ptr, mainprog_ptr->image_data);
+    return 0;
+}
+/* returns 0 if succeeds, 2 if libpng problem */
+int writepng_encode_finish(mainprog_info *mainprog_ptr)   /* NON-interlaced! */
+{
+    png_structp png_ptr = (png_structp)mainprog_ptr->png_ptr;
+    png_infop info_ptr = (png_infop)mainprog_ptr->info_ptr;
+    /* as always, setjmp() must be called in every function that calls a
+     * PNG-writing libpng function */
+    if (setjmp(mainprog_ptr->jmpbuf)) {
+        png_destroy_write_struct(&png_ptr, &info_ptr);
+        mainprog_ptr->png_ptr = NULL;
+        mainprog_ptr->info_ptr = NULL;
+        return 2;
+    }
+    /* close out PNG file; if we had any text or time info to write after
+     * the IDATs, second argument would be info_ptr: */
+    png_write_end(png_ptr, NULL);
+    return 0;
+}
+void writepng_cleanup(mainprog_info *mainprog_ptr)
+{
+    png_structp png_ptr = (png_structp)mainprog_ptr->png_ptr;
+    png_infop info_ptr = (png_infop)mainprog_ptr->info_ptr;
+    if (png_ptr && info_ptr)
+        png_destroy_write_struct(&png_ptr, &info_ptr);
+}
+static void writepng_error_handler(png_structp png_ptr, png_const_charp msg)
+{
+    mainprog_info  *mainprog_ptr;
+    /* This function, aside from the extra step of retrieving the "error
+     * pointer" (below) and the fact that it exists within the application
+     * rather than within libpng, is essentially identical to libpng's
+     * default error handler.  The second point is critical:  since both
+     * setjmp() and longjmp() are called from the same code, they are
+     * guaranteed to have compatible notions of how big a jmp_buf is,
+     * regardless of whether _BSD_SOURCE or anything else has (or has not)
+     * been defined. */
+    fprintf(stderr, "writepng libpng error: %s\n", msg);
+    fflush(stderr);
+    mainprog_ptr = png_get_error_ptr(png_ptr);
+    if (mainprog_ptr == NULL) {         /* we are completely hosed now */
+        fprintf(stderr,
+          "writepng severe error:  jmpbuf not recoverable; terminating.\n");
+        fflush(stderr);
+        exit(99);
+    }
+    /* Now we have our data structure we can use the information in it
+     * to return control to our own higher level code (all the points
+     * where 'setjmp' is called in this file.)  This will work with other
+     * error handling mechanisms as well - libpng always calls png_error
+     * when it can proceed no further, thus, so long as the error handler
+     * is intercepted, application code can do its own error recovery.
+     */
+    longjmp(mainprog_ptr->jmpbuf, 1);
+}
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/writepng.h b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/writepng.h
new file mode 100644
index 0000000..904e4fb
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/writepng.h
@@ -0,0 +1,133 @@
+/*---------------------------------------------------------------------------
+   wpng - simple PNG-writing program                             writepng.h
+  ---------------------------------------------------------------------------
+      Copyright (c) 1998-2007 Greg Roelofs.  All rights reserved.
+      This software is provided "as is," without warranty of any kind,
+      express or implied.  In no event shall the author or contributors
+      be held liable for any damages arising in any way from the use of
+      this software.
+      The contents of this file are DUAL-LICENSED.  You may modify and/or
+      redistribute this software according to the terms of one of the
+      following two licenses (at your option):
+      LICENSE 1 ("BSD-like with advertising clause"):
+      Permission is granted to anyone to use this software for any purpose,
+      including commercial applications, and to alter it and redistribute
+      it freely, subject to the following restrictions:
+      1. Redistributions of source code must retain the above copyright
+         notice, disclaimer, and this list of conditions.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, disclaimer, and this list of conditions in the documenta-
+         tion and/or other materials provided with the distribution.
+      3. All advertising materials mentioning features or use of this
+         software must display the following acknowledgment:
+            This product includes software developed by Greg Roelofs
+            and contributors for the book, "PNG: The Definitive Guide,"
+            published by O'Reilly and Associates.
+      LICENSE 2 (GNU GPL v2 or later):
+      This program is free software; you can redistribute it and/or modify
+      it under the terms of the GNU General Public License as published by
+      the Free Software Foundation; either version 2 of the License, or
+      (at your option) any later version.
+      This program is distributed in the hope that it will be useful,
+      but WITHOUT ANY WARRANTY; without even the implied warranty of
+      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+      GNU General Public License for more details.
+      You should have received a copy of the GNU General Public License
+      along with this program; if not, write to the Free Software Foundation,
+      Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+  ---------------------------------------------------------------------------*/
+#ifndef TRUE
+#  define TRUE 1
+#  define FALSE 0
+#endif
+#ifndef MAX
+#  define MAX(a,b)  ((a) > (b)? (a) : (b))
+#  define MIN(a,b)  ((a) < (b)? (a) : (b))
+#endif
+#ifdef DEBUG
+#  define Trace(x)  {fprintf x ; fflush(stderr); fflush(stdout);}
+#else
+#  define Trace(x)  ;
+#endif
+#define TEXT_TITLE    0x01
+#define TEXT_AUTHOR   0x02
+#define TEXT_DESC     0x04
+#define TEXT_COPY     0x08
+#define TEXT_EMAIL    0x10
+#define TEXT_URL      0x20
+#define TEXT_TITLE_OFFSET        0
+#define TEXT_AUTHOR_OFFSET      72
+#define TEXT_COPY_OFFSET     (2*72)
+#define TEXT_EMAIL_OFFSET    (3*72)
+#define TEXT_URL_OFFSET      (4*72)
+#define TEXT_DESC_OFFSET     (5*72)
+typedef unsigned char   uch;
+typedef unsigned short  ush;
+typedef unsigned long   ulg;
+typedef struct _mainprog_info {
+    double gamma;
+    long width;
+    long height;
+    time_t modtime;
+    FILE *infile;
+    FILE *outfile;
+    void *png_ptr;
+    void *info_ptr;
+    uch *image_data;
+    uch **row_pointers;
+    char *title;
+    char *author;
+    char *desc;
+    char *copyright;
+    char *email;
+    char *url;
+    int filter;    /* command-line-filter flag, not PNG row filter! */
+    int pnmtype;
+    int sample_depth;
+    int interlaced;
+    int have_bg;
+    int have_time;
+    int have_text;
+    jmp_buf jmpbuf;
+    uch bg_red;
+    uch bg_green;
+    uch bg_blue;
+} mainprog_info;
+/* prototypes for public functions in writepng.c */
+void writepng_version_info(void);
+int writepng_init(mainprog_info *mainprog_ptr);
+int writepng_encode_image(mainprog_info *mainprog_ptr);
+int writepng_encode_row(mainprog_info *mainprog_ptr);
+int writepng_encode_finish(mainprog_info *mainprog_ptr);
+void writepng_cleanup(mainprog_info *mainprog_ptr);
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/libtests/pngvalid.c b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/libtests/pngvalid.c
new file mode 100644
index 0000000..c7068fa
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/libtests/pngvalid.c
@@ -0,0 +1,9837 @@
+/* pngvalid.c - validate libpng by constructing then reading png files.
+ *
+ * Last changed in libpng 1.5.8 [%RDATE%]
+ * Copyright (c) 2012 Glenn Randers-Pehrson
+ * Written by John Cunningham Bowler
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * NOTES:
+ *   This is a C program that is intended to be linked against libpng.  It
+ *   generates bitmaps internally, stores them as PNG files (using the
+ *   sequential write code) then reads them back (using the sequential
+ *   read code) and validates that the result has the correct data.
+ *
+ *   The program can be modified and extended to test the correctness of
+ *   transformations performed by libpng.
+ */
+#define _POSIX_SOURCE 1
+#define _ISOC99_SOURCE 1 /* For floating point */
+#define _GNU_SOURCE 1 /* For the floating point exception extension */
+#include <signal.h>
+#ifdef HAVE_FEENABLEEXCEPT
+#  include <fenv.h>
+#endif
+/* Define the following to use this test against your installed libpng, rather
+ * than the one being built here:
+ */
+#ifdef PNG_FREESTANDING_TESTS
+#  include <png.h>
+#else
+#  include "../../png.h"
+#endif
+#if PNG_LIBPNG_VER < 10500
+/* This deliberately lacks the PNG_CONST. */
+typedef png_byte *png_const_bytep;
+/* This is copied from 1.5.1 png.h: */
+#define PNG_INTERLACE_ADAM7_PASSES 7
+#define PNG_PASS_START_ROW(pass) (((1U&~(pass))<<(3-((pass)>>1)))&7)
+#define PNG_PASS_START_COL(pass) (((1U& (pass))<<(3-(((pass)+1)>>1)))&7)
+#define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3)
+#define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3)
+#define PNG_PASS_ROWS(height, pass) (((height)+(((1<<PNG_PASS_ROW_SHIFT(pass))\
+   -1)-PNG_PASS_START_ROW(pass)))>>PNG_PASS_ROW_SHIFT(pass))
+#define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\
+   -1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass))
+#define PNG_ROW_FROM_PASS_ROW(yIn, pass) \
+   (((yIn)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass))
+#define PNG_COL_FROM_PASS_COL(xIn, pass) \
+   (((xIn)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass))
+#define PNG_PASS_MASK(pass,off) ( \
+   ((0x110145AFU>>(((7-(off))-(pass))<<2)) & 0xFU) | \
+   ((0x01145AF0U>>(((7-(off))-(pass))<<2)) & 0xF0U))
+#define PNG_ROW_IN_INTERLACE_PASS(y, pass) \
+   ((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1)
+#define PNG_COL_IN_INTERLACE_PASS(x, pass) \
+   ((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1)
+/* These are needed too for the default build: */
+#define PNG_WRITE_16BIT_SUPPORTED
+#define PNG_READ_16BIT_SUPPORTED
+/* This comes from pnglibconf.h afer 1.5: */
+#define PNG_FP_1 100000
+#define PNG_GAMMA_THRESHOLD_FIXED\
+   ((png_fixed_point)(PNG_GAMMA_THRESHOLD * PNG_FP_1))
+#endif
+#include "zlib.h"   /* For crc32 */
+#include <float.h>  /* For floating point constants */
+#include <stdlib.h> /* For malloc */
+#include <string.h> /* For memcpy, memset */
+#include <math.h>   /* For floor */
+/* Unused formal parameter errors are removed using the following macro which is
+ * expected to have no bad effects on performance.
+ */
+#ifndef UNUSED
+#  if defined(__GNUC__) || defined(_MSC_VER)
+#     define UNUSED(param) (void)param;
+#  else
+#     define UNUSED(param)
+#  endif
+#endif
+/***************************** EXCEPTION HANDLING *****************************/
+#include "../visupng/cexcept.h"
+#ifdef __cplusplus
+#  define this not_the_cpp_this
+#  define new not_the_cpp_new
+#  define voidcast(type, value) static_cast<type>(value)
+#else
+#  define voidcast(type, value) (value)
+#endif /* __cplusplus */
+struct png_store;
+define_exception_type(struct png_store*);
+/* The following are macros to reduce typing everywhere where the well known
+ * name 'the_exception_context' must be defined.
+ */
+#define anon_context(ps) struct exception_context *the_exception_context = \
+   &(ps)->exception_context
+#define context(ps,fault) anon_context(ps); png_store *fault
+/******************************* UTILITIES ************************************/
+/* Error handling is particularly problematic in production code - error
+ * handlers often themselves have bugs which lead to programs that detect
+ * minor errors crashing.  The following functions deal with one very
+ * common class of errors in error handlers - attempting to format error or
+ * warning messages into buffers that are too small.
+ */
+static size_t safecat(char *buffer, size_t bufsize, size_t pos,
+   PNG_CONST char *cat)
+{
+   while (pos < bufsize && cat != NULL && *cat != 0)
+      buffer[pos++] = *cat++;
+   if (pos >= bufsize)
+      pos = bufsize-1;
+   buffer[pos] = 0;
+   return pos;
+}
+static size_t safecatn(char *buffer, size_t bufsize, size_t pos, int n)
+{
+   char number[64];
+   sprintf(number, "%d", n);
+   return safecat(buffer, bufsize, pos, number);
+}
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+static size_t safecatd(char *buffer, size_t bufsize, size_t pos, double d,
+    int precision)
+{
+   char number[64];
+   sprintf(number, "%.*f", precision, d);
+   return safecat(buffer, bufsize, pos, number);
+}
+#endif
+static PNG_CONST char invalid[] = "invalid";
+static PNG_CONST char sep[] = ": ";
+static PNG_CONST char *colour_types[8] =
+{
+   "grayscale", invalid, "truecolour", "indexed-colour",
+   "grayscale with alpha", invalid, "truecolour with alpha", invalid
+};
+/* Convert a double precision value to fixed point. */
+static png_fixed_point
+fix(double d)
+{
+   d = floor(d * PNG_FP_1 + .5);
+   return (png_fixed_point)d;
+}
+/* Generate random bytes.  This uses a boring repeatable algorithm and it
+ * is implemented here so that it gives the same set of numbers on every
+ * architecture.  It's a linear congruential generator (Knuth or Sedgewick
+ * "Algorithms") but it comes from the 'feedback taps' table in Horowitz and
+ * Hill, "The Art of Electronics".
+ */
+static void
+make_random_bytes(png_uint_32* seed, void* pv, size_t size)
+{
+   png_uint_32 u0 = seed[0], u1 = seed[1];
+   png_bytep bytes = voidcast(png_bytep, pv);
+   /* There are thirty three bits, the next bit in the sequence is bit-33 XOR
+    * bit-20.  The top 1 bit is in u1, the bottom 32 are in u0.
+    */
+   size_t i;
+   for (i=0; i<size; ++i)
+   {
+      /* First generate 8 new bits then shift them in at the end. */
+      png_uint_32 u = ((u0 >> (20-8)) ^ ((u1 << 7) | (u0 >> (32-7)))) & 0xff;
+      u1 <<= 8;
+      u1 |= u0 >> 24;
+      u0 <<= 8;
+      u0 |= u;
+      *bytes++ = (png_byte)u;
+   }
+   seed[0] = u0;
+   seed[1] = u1;
+}
+static void
+make_four_random_bytes(png_uint_32* seed, png_bytep bytes)
+{
+   make_random_bytes(seed, bytes, 4);
+}
+static void
+randomize(void *pv, size_t size)
+{
+   static png_uint_32 random_seed[2] = {0x56789abc, 0xd};
+   make_random_bytes(random_seed, pv, size);
+}
+#define RANDOMIZE(this) randomize(&(this), sizeof (this))
+static unsigned int
+random_mod(unsigned int max)
+{
+   unsigned int x;
+   RANDOMIZE(x);
+   return x % max; /* 0 .. max-1 */
+}
+static int
+random_choice(void)
+{
+   unsigned char x;
+   RANDOMIZE(x);
+   return x & 1;
+}
+/* A numeric ID based on PNG file characteristics.  The 'do_interlace' field
+ * simply records whether pngvalid did the interlace itself or whether it
+ * was done by libpng.  Width and height must be less than 256.  'palette' is an
+ * index of the palette to use for formats with a palette (0 otherwise.)
+ */
+#define FILEID(col, depth, palette, interlace, width, height, do_interlace) \
+   ((png_uint_32)((col) + ((depth)<<3) + ((palette)<<8) + ((interlace)<<13) + \
+    (((do_interlace)!=0)<<15) + ((width)<<16) + ((height)<<24)))
+#define COL_FROM_ID(id) ((png_byte)((id)& 0x7U))
+#define DEPTH_FROM_ID(id) ((png_byte)(((id) >> 3) & 0x1fU))
+#define PALETTE_FROM_ID(id) ((int)(((id) >> 8) & 0x1f))
+#define INTERLACE_FROM_ID(id) ((int)(((id) >> 13) & 0x3))
+#define DO_INTERLACE_FROM_ID(id) ((int)(((id)>>15) & 1))
+#define WIDTH_FROM_ID(id) (((id)>>16) & 0xff)
+#define HEIGHT_FROM_ID(id) (((id)>>24) & 0xff)
+/* Utility to construct a standard name for a standard image. */
+static size_t
+standard_name(char *buffer, size_t bufsize, size_t pos, png_byte colour_type,
+    int bit_depth, int npalette, int interlace_type,
+    png_uint_32 w, png_uint_32 h, int do_interlace)
+{
+   pos = safecat(buffer, bufsize, pos, colour_types[colour_type]);
+   if (npalette > 0)
+   {
+      pos = safecat(buffer, bufsize, pos, "[");
+      pos = safecatn(buffer, bufsize, pos, npalette);
+      pos = safecat(buffer, bufsize, pos, "]");
+   }
+   pos = safecat(buffer, bufsize, pos, " ");
+   pos = safecatn(buffer, bufsize, pos, bit_depth);
+   pos = safecat(buffer, bufsize, pos, " bit");
+   if (interlace_type != PNG_INTERLACE_NONE)
+   {
+      pos = safecat(buffer, bufsize, pos, " interlaced");
+      if (do_interlace)
+         pos = safecat(buffer, bufsize, pos, "(pngvalid)");
+      else
+         pos = safecat(buffer, bufsize, pos, "(libpng)");
+   }
+   if (w > 0 || h > 0)
+   {
+      pos = safecat(buffer, bufsize, pos, " ");
+      pos = safecatn(buffer, bufsize, pos, w);
+      pos = safecat(buffer, bufsize, pos, "x");
+      pos = safecatn(buffer, bufsize, pos, h);
+   }
+   return pos;
+}
+static size_t
+standard_name_from_id(char *buffer, size_t bufsize, size_t pos, png_uint_32 id)
+{
+   return standard_name(buffer, bufsize, pos, COL_FROM_ID(id),
+      DEPTH_FROM_ID(id), PALETTE_FROM_ID(id), INTERLACE_FROM_ID(id),
+      WIDTH_FROM_ID(id), HEIGHT_FROM_ID(id), DO_INTERLACE_FROM_ID(id));
+}
+/* Convenience API and defines to list valid formats.  Note that 16 bit read and
+ * write support is required to do 16 bit read tests (we must be able to make a
+ * 16 bit image to test!)
+ */
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+#  define WRITE_BDHI 4
+#  ifdef PNG_READ_16BIT_SUPPORTED
+#     define READ_BDHI 4
+#     define DO_16BIT
+#  endif
+#else
+#  define WRITE_BDHI 3
+#endif
+#ifndef DO_16BIT
+#  define READ_BDHI 3
+#endif
+/* The following defines the number of different palettes to generate for
+ * each log bit depth of a colour type 3 standard image.
+ */
+#define PALETTE_COUNT(bit_depth) ((bit_depth) > 4 ? 1 : 16)
+static int
+next_format(png_bytep colour_type, png_bytep bit_depth, int* palette_number)
+{
+   if (*bit_depth == 0)
+   {
+      *colour_type = 0, *bit_depth = 1, *palette_number = 0;
+      return 1;
+   }
+   if (*colour_type == 3)
+   {
+      /* Add multiple palettes for colour type 3. */
+      if (++*palette_number < PALETTE_COUNT(*bit_depth))
+         return 1;
+      *palette_number = 0;
+   }
+   *bit_depth = (png_byte)(*bit_depth << 1);
+   /* Palette images are restricted to 8 bit depth */
+   if (*bit_depth <= 8
+#     ifdef DO_16BIT
+         || (*colour_type != 3 && *bit_depth <= 16)
+#     endif
+      )
+      return 1;
+   /* Move to the next color type, or return 0 at the end. */
+   switch (*colour_type)
+   {
+      case 0:
+         *colour_type = 2;
+         *bit_depth = 8;
+         return 1;
+      case 2:
+         *colour_type = 3;
+         *bit_depth = 1;
+         return 1;
+      case 3:
+         *colour_type = 4;
+         *bit_depth = 8;
+         return 1;
+      case 4:
+         *colour_type = 6;
+         *bit_depth = 8;
+         return 1;
+      default:
+         return 0;
+   }
+}
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+static unsigned int
+sample(png_const_bytep row, png_byte colour_type, png_byte bit_depth,
+    png_uint_32 x, unsigned int sample_index)
+{
+   png_uint_32 bit_index, result;
+   /* Find a sample index for the desired sample: */
+   x *= bit_depth;
+   bit_index = x;
+   if ((colour_type & 1) == 0) /* !palette */
+   {
+      if (colour_type & 2)
+         bit_index *= 3;
+      if (colour_type & 4)
+         bit_index += x; /* Alpha channel */
+      /* Multiple channels; select one: */
+      if (colour_type & (2+4))
+         bit_index += sample_index * bit_depth;
+   }
+   /* Return the sample from the row as an integer. */
+   row += bit_index >> 3;
+   result = *row;
+   if (bit_depth == 8)
+      return result;
+   else if (bit_depth > 8)
+      return (result << 8) + *++row;
+   /* Less than 8 bits per sample. */
+   bit_index &= 7;
+   return (result >> (8-bit_index-bit_depth)) & ((1U<<bit_depth)-1);
+}
+#endif /* PNG_READ_TRANSFORMS_SUPPORTED */
+/* Copy a single pixel, of a given size, from one buffer to another -
+ * while this is basically bit addressed there is an implicit assumption
+ * that pixels 8 or more bits in size are byte aligned and that pixels
+ * do not otherwise cross byte boundaries.  (This is, so far as I know,
+ * universally true in bitmap computer graphics.  [JCB 20101212])
+ *
+ * NOTE: The to and from buffers may be the same.
+ */
+static void
+pixel_copy(png_bytep toBuffer, png_uint_32 toIndex,
+   png_const_bytep fromBuffer, png_uint_32 fromIndex, unsigned int pixelSize)
+{
+   /* Assume we can multiply by 'size' without overflow because we are
+    * just working in a single buffer.
+    */
+   toIndex *= pixelSize;
+   fromIndex *= pixelSize;
+   if (pixelSize < 8) /* Sub-byte */
+   {
+      /* Mask to select the location of the copied pixel: */
+      unsigned int destMask = ((1U<<pixelSize)-1) << (8-pixelSize-(toIndex&7));
+      /* The following read the entire pixels and clears the extra: */
+      unsigned int destByte = toBuffer[toIndex >> 3] & ~destMask;
+      unsigned int sourceByte = fromBuffer[fromIndex >> 3];
+      /* Don't rely on << or >> supporting '0' here, just in case: */
+      fromIndex &= 7;
+      if (fromIndex > 0) sourceByte <<= fromIndex;
+      if ((toIndex & 7) > 0) sourceByte >>= toIndex & 7;
+      toBuffer[toIndex >> 3] = (png_byte)(destByte | (sourceByte & destMask));
+   }
+   else /* One or more bytes */
+      memmove(toBuffer+(toIndex>>3), fromBuffer+(fromIndex>>3), pixelSize>>3);
+}
+/* Copy a complete row of pixels, taking into account potential partial
+ * bytes at the end.
+ */
+static void
+row_copy(png_bytep toBuffer, png_const_bytep fromBuffer, unsigned int bitWidth)
+{
+   memcpy(toBuffer, fromBuffer, bitWidth >> 3);
+   if ((bitWidth & 7) != 0)
+   {
+      unsigned int mask;
+      toBuffer += bitWidth >> 3;
+      fromBuffer += bitWidth >> 3;
+      /* The remaining bits are in the top of the byte, the mask is the bits to
+       * retain.
+       */
+      mask = 0xff >> (bitWidth & 7);
+      *toBuffer = (png_byte)((*toBuffer & mask) | (*fromBuffer & ~mask));
+   }
+}
+/* Compare pixels - they are assumed to start at the first byte in the
+ * given buffers.
+ */
+static int
+pixel_cmp(png_const_bytep pa, png_const_bytep pb, png_uint_32 bit_width)
+{
+#if PNG_LIBPNG_VER < 10506
+   if (memcmp(pa, pb, bit_width>>3) == 0)
+   {
+      png_uint_32 p;
+      if ((bit_width & 7) == 0) return 0;
+      /* Ok, any differences? */
+      p = pa[bit_width >> 3];
+      p ^= pb[bit_width >> 3];
+      if (p == 0) return 0;
+      /* There are, but they may not be significant, remove the bits
+       * after the end (the low order bits in PNG.)
+       */
+      bit_width &= 7;
+      p >>= 8-bit_width;
+      if (p == 0) return 0;
+   }
+#else
+   /* From libpng-1.5.6 the overwrite should be fixed, so compare the trailing
+    * bits too:
+    */
+   if (memcmp(pa, pb, (bit_width+7)>>3) == 0)
+      return 0;
+#endif
+   /* Return the index of the changed byte. */
+   {
+      png_uint_32 where = 0;
+      while (pa[where] == pb[where]) ++where;
+      return 1+where;
+   }
+}
+/*************************** BASIC PNG FILE WRITING ***************************/
+/* A png_store takes data from the sequential writer or provides data
+ * to the sequential reader.  It can also store the result of a PNG
+ * write for later retrieval.
+ */
+#define STORE_BUFFER_SIZE 500 /* arbitrary */
+typedef struct png_store_buffer
+{
+   struct png_store_buffer*  prev;    /* NOTE: stored in reverse order */
+   png_byte                  buffer[STORE_BUFFER_SIZE];
+} png_store_buffer;
+#define FILE_NAME_SIZE 64
+typedef struct store_palette_entry /* record of a single palette entry */
+{
+   png_byte red;
+   png_byte green;
+   png_byte blue;
+   png_byte alpha;
+} store_palette_entry, store_palette[256];
+typedef struct png_store_file
+{
+   struct png_store_file*  next;      /* as many as you like... */
+   char                    name[FILE_NAME_SIZE];
+   png_uint_32             id;        /* must be correct (see FILEID) */
+   png_size_t              datacount; /* In this (the last) buffer */
+   png_store_buffer        data;      /* Last buffer in file */
+   int                     npalette;  /* Number of entries in palette */
+   store_palette_entry*    palette;   /* May be NULL */
+} png_store_file;
+/* The following is a pool of memory allocated by a single libpng read or write
+ * operation.
+ */
+typedef struct store_pool
+{
+   struct png_store    *store;   /* Back pointer */
+   struct store_memory *list;    /* List of allocated memory */
+   png_byte             mark[4]; /* Before and after data */
+   /* Statistics for this run. */
+   png_alloc_size_t     max;     /* Maximum single allocation */
+   png_alloc_size_t     current; /* Current allocation */
+   png_alloc_size_t     limit;   /* Highest current allocation */
+   png_alloc_size_t     total;   /* Total allocation */
+   /* Overall statistics (retained across successive runs). */
+   png_alloc_size_t     max_max;
+   png_alloc_size_t     max_limit;
+   png_alloc_size_t     max_total;
+} store_pool;
+typedef struct png_store
+{
+   /* For cexcept.h exception handling - simply store one of these;
+    * the context is a self pointer but it may point to a different
+    * png_store (in fact it never does in this program.)
+    */
+   struct exception_context
+                      exception_context;
+   unsigned int       verbose :1;
+   unsigned int       treat_warnings_as_errors :1;
+   unsigned int       expect_error :1;
+   unsigned int       expect_warning :1;
+   unsigned int       saw_warning :1;
+   unsigned int       speed :1;
+   unsigned int       progressive :1; /* use progressive read */
+   unsigned int       validated :1;   /* used as a temporary flag */
+   int                nerrors;
+   int                nwarnings;
+   char               test[128]; /* Name of test */
+   char               error[256];
+   /* Read fields */
+   png_structp        pread;    /* Used to read a saved file */
+   png_infop          piread;
+   png_store_file*    current;  /* Set when reading */
+   png_store_buffer*  next;     /* Set when reading */
+   png_size_t         readpos;  /* Position in *next */
+   png_byte*          image;    /* Buffer for reading interlaced images */
+   png_size_t         cb_image; /* Size of this buffer */
+   png_size_t         cb_row;   /* Row size of the image(s) */
+   png_uint_32        image_h;  /* Number of rows in a single image */
+   store_pool         read_memory_pool;
+   /* Write fields */
+   png_store_file*    saved;
+   png_structp        pwrite;   /* Used when writing a new file */
+   png_infop          piwrite;
+   png_size_t         writepos; /* Position in .new */
+   char               wname[FILE_NAME_SIZE];
+   png_store_buffer   new;      /* The end of the new PNG file being written. */
+   store_pool         write_memory_pool;
+   store_palette_entry* palette;
+   int                  npalette;
+} png_store;
+/* Initialization and cleanup */
+static void
+store_pool_mark(png_bytep mark)
+{
+   static png_uint_32 store_seed[2] = { 0x12345678, 1};
+   make_four_random_bytes(store_seed, mark);
+}
+/* Use this for random 32 bit values; this function makes sure the result is
+ * non-zero.
+ */
+static png_uint_32
+random_32(void)
+{
+   for(;;)
+   {
+      png_byte mark[4];
+      png_uint_32 result;
+      store_pool_mark(mark);
+      result = png_get_uint_32(mark);
+      if (result != 0)
+         return result;
+   }
+}
+static void
+store_pool_init(png_store *ps, store_pool *pool)
+{
+   memset(pool, 0, sizeof *pool);
+   pool->store = ps;
+   pool->list = NULL;
+   pool->max = pool->current = pool->limit = pool->total = 0;
+   pool->max_max = pool->max_limit = pool->max_total = 0;
+   store_pool_mark(pool->mark);
+}
+static void
+store_init(png_store* ps)
+{
+   memset(ps, 0, sizeof *ps);
+   init_exception_context(&ps->exception_context);
+   store_pool_init(ps, &ps->read_memory_pool);
+   store_pool_init(ps, &ps->write_memory_pool);
+   ps->verbose = 0;
+   ps->treat_warnings_as_errors = 0;
+   ps->expect_error = 0;
+   ps->expect_warning = 0;
+   ps->saw_warning = 0;
+   ps->speed = 0;
+   ps->progressive = 0;
+   ps->validated = 0;
+   ps->nerrors = ps->nwarnings = 0;
+   ps->pread = NULL;
+   ps->piread = NULL;
+   ps->saved = ps->current = NULL;
+   ps->next = NULL;
+   ps->readpos = 0;
+   ps->image = NULL;
+   ps->cb_image = 0;
+   ps->cb_row = 0;
+   ps->image_h = 0;
+   ps->pwrite = NULL;
+   ps->piwrite = NULL;
+   ps->writepos = 0;
+   ps->new.prev = NULL;
+   ps->palette = NULL;
+   ps->npalette = 0;
+}
+static void
+store_freebuffer(png_store_buffer* psb)
+{
+   if (psb->prev)
+   {
+      store_freebuffer(psb->prev);
+      free(psb->prev);
+      psb->prev = NULL;
+   }
+}
+static void
+store_freenew(png_store *ps)
+{
+   store_freebuffer(&ps->new);
+   ps->writepos = 0;
+   if (ps->palette != NULL)
+   {
+      free(ps->palette);
+      ps->palette = NULL;
+      ps->npalette = 0;
+   }
+}
+static void
+store_storenew(png_store *ps)
+{
+   png_store_buffer *pb;
+   if (ps->writepos != STORE_BUFFER_SIZE)
+      png_error(ps->pwrite, "invalid store call");
+   pb = voidcast(png_store_buffer*, malloc(sizeof *pb));
+   if (pb == NULL)
+      png_error(ps->pwrite, "store new: OOM");
+   *pb = ps->new;
+   ps->new.prev = pb;
+   ps->writepos = 0;
+}
+static void
+store_freefile(png_store_file **ppf)
+{
+   if (*ppf != NULL)
+   {
+      store_freefile(&(*ppf)->next);
+      store_freebuffer(&(*ppf)->data);
+      (*ppf)->datacount = 0;
+      if ((*ppf)->palette != NULL)
+      {
+         free((*ppf)->palette);
+         (*ppf)->palette = NULL;
+         (*ppf)->npalette = 0;
+      }
+      free(*ppf);
+      *ppf = NULL;
+   }
+}
+/* Main interface to file storeage, after writing a new PNG file (see the API
+ * below) call store_storefile to store the result with the given name and id.
+ */
+static void
+store_storefile(png_store *ps, png_uint_32 id)
+{
+   png_store_file *pf = voidcast(png_store_file*, malloc(sizeof *pf));
+   if (pf == NULL)
+      png_error(ps->pwrite, "storefile: OOM");
+   safecat(pf->name, sizeof pf->name, 0, ps->wname);
+   pf->id = id;
+   pf->data = ps->new;
+   pf->datacount = ps->writepos;
+   ps->new.prev = NULL;
+   ps->writepos = 0;
+   pf->palette = ps->palette;
+   pf->npalette = ps->npalette;
+   ps->palette = 0;
+   ps->npalette = 0;
+   /* And save it. */
+   pf->next = ps->saved;
+   ps->saved = pf;
+}
+/* Generate an error message (in the given buffer) */
+static size_t
+store_message(png_store *ps, png_structp pp, char *buffer, size_t bufsize,
+   size_t pos, PNG_CONST char *msg)
+{
+   if (pp != NULL && pp == ps->pread)
+   {
+      /* Reading a file */
+      pos = safecat(buffer, bufsize, pos, "read: ");
+      if (ps->current != NULL)
+      {
+         pos = safecat(buffer, bufsize, pos, ps->current->name);
+         pos = safecat(buffer, bufsize, pos, sep);
+      }
+   }
+   else if (pp != NULL && pp == ps->pwrite)
+   {
+      /* Writing a file */
+      pos = safecat(buffer, bufsize, pos, "write: ");
+      pos = safecat(buffer, bufsize, pos, ps->wname);
+      pos = safecat(buffer, bufsize, pos, sep);
+   }
+   else
+   {
+      /* Neither reading nor writing (or a memory error in struct delete) */
+      pos = safecat(buffer, bufsize, pos, "pngvalid: ");
+   }
+   if (ps->test[0] != 0)
+   {
+      pos = safecat(buffer, bufsize, pos, ps->test);
+      pos = safecat(buffer, bufsize, pos, sep);
+   }
+   pos = safecat(buffer, bufsize, pos, msg);
+   return pos;
+}
+/* Verbose output to the error stream: */
+static void
+store_verbose(png_store *ps, png_structp pp, png_const_charp prefix,
+   png_const_charp message)
+{
+   char buffer[512];
+   if (prefix)
+      fputs(prefix, stderr);
+   (void)store_message(ps, pp, buffer, sizeof buffer, 0, message);
+   fputs(buffer, stderr);
+   fputc('\n', stderr);
+}
+/* Log an error or warning - the relevant count is always incremented. */
+static void
+store_log(png_store* ps, png_structp pp, png_const_charp message, int is_error)
+{
+   /* The warning is copied to the error buffer if there are no errors and it is
+    * the first warning.  The error is copied to the error buffer if it is the
+    * first error (overwriting any prior warnings).
+    */
+   if (is_error ? (ps->nerrors)++ == 0 :
+       (ps->nwarnings)++ == 0 && ps->nerrors == 0)
+      store_message(ps, pp, ps->error, sizeof ps->error, 0, message);
+   if (ps->verbose)
+      store_verbose(ps, pp, is_error ? "error: " : "warning: ", message);
+}
+/* Internal error function, called with a png_store but no libpng stuff. */
+static void
+internal_error(png_store *ps, png_const_charp message)
+{
+   store_log(ps, NULL, message, 1 /* error */);
+   /* And finally throw an exception. */
+   {
+      struct exception_context *the_exception_context = &ps->exception_context;
+      Throw ps;
+   }
+}
+/* Functions to use as PNG callbacks. */
+static void
+store_error(png_structp pp, png_const_charp message) /* PNG_NORETURN */
+{
+   png_store *ps = voidcast(png_store*, png_get_error_ptr(pp));
+   if (!ps->expect_error)
+      store_log(ps, pp, message, 1 /* error */);
+   /* And finally throw an exception. */
+   {
+      struct exception_context *the_exception_context = &ps->exception_context;
+      Throw ps;
+   }
+}
+static void
+store_warning(png_structp pp, png_const_charp message)
+{
+   png_store *ps = voidcast(png_store*, png_get_error_ptr(pp));
+   if (!ps->expect_warning)
+      store_log(ps, pp, message, 0 /* warning */);
+   else
+      ps->saw_warning = 1;
+}
+/* These somewhat odd functions are used when reading an image to ensure that
+ * the buffer is big enough, the png_structp is for errors.
+ */
+/* Return a single row from the correct image. */
+static png_bytep
+store_image_row(PNG_CONST png_store* ps, png_structp pp, int nImage,
+   png_uint_32 y)
+{
+   png_size_t coffset = (nImage * ps->image_h + y) * (ps->cb_row + 5) + 2;
+   if (ps->image == NULL)
+      png_error(pp, "no allocated image");
+   if (coffset + ps->cb_row + 3 > ps->cb_image)
+      png_error(pp, "image too small");
+   return ps->image + coffset;
+}
+static void
+store_image_free(png_store *ps, png_structp pp)
+{
+   if (ps->image != NULL)
+   {
+      png_bytep image = ps->image;
+      if (image[-1] != 0xed || image[ps->cb_image] != 0xfe)
+      {
+         if (pp != NULL)
+            png_error(pp, "png_store image overwrite (1)");
+         else
+            store_log(ps, NULL, "png_store image overwrite (2)", 1);
+      }
+      ps->image = NULL;
+      ps->cb_image = 0;
+      --image;
+      free(image);
+   }
+}
+static void
+store_ensure_image(png_store *ps, png_structp pp, int nImages, png_size_t cbRow,
+   png_uint_32 cRows)
+{
+   png_size_t cb = nImages * cRows * (cbRow + 5);
+   if (ps->cb_image < cb)
+   {
+      png_bytep image;
+      store_image_free(ps, pp);
+      /* The buffer is deliberately mis-aligned. */
+      image = voidcast(png_bytep, malloc(cb+2));
+      if (image == NULL)
+      {
+         /* Called from the startup - ignore the error for the moment. */
+         if (pp == NULL)
+            return;
+         png_error(pp, "OOM allocating image buffer");
+      }
+      /* These magic tags are used to detect overwrites above. */
+      ++image;
+      image[-1] = 0xed;
+      image[cb] = 0xfe;
+      ps->image = image;
+      ps->cb_image = cb;
+   }
+   /* We have an adequate sized image; lay out the rows.  There are 2 bytes at
+    * the start and three at the end of each (this ensures that the row
+    * alignment starts out odd - 2+1 and changes for larger images on each row.)
+    */
+   ps->cb_row = cbRow;
+   ps->image_h = cRows;
+   /* For error checking, the whole buffer is set to 10110010 (0xb2 - 178).
+    * This deliberately doesn't match the bits in the size test image which are
+    * outside the image; these are set to 0xff (all 1).  To make the row
+    * comparison work in the 'size' test case the size rows are pre-initialized
+    * to the same value prior to calling 'standard_row'.
+    */
+   memset(ps->image, 178, cb);
+   /* Then put in the marks. */
+   while (--nImages >= 0)
+   {
+      png_uint_32 y;
+      for (y=0; y<cRows; ++y)
+      {
+         png_bytep row = store_image_row(ps, pp, nImages, y);
+         /* The markers: */
+         row[-2] = 190;
+         row[-1] = 239;
+         row[cbRow] = 222;
+         row[cbRow+1] = 173;
+         row[cbRow+2] = 17;
+      }
+   }
+}
+static void
+store_image_check(PNG_CONST png_store* ps, png_structp pp, int iImage)
+{
+   png_const_bytep image = ps->image;
+   if (image[-1] != 0xed || image[ps->cb_image] != 0xfe)
+      png_error(pp, "image overwrite");
+   else
+   {
+      png_size_t cbRow = ps->cb_row;
+      png_uint_32 rows = ps->image_h;
+      image += iImage * (cbRow+5) * ps->image_h;
+      image += 2; /* skip image first row markers */
+      while (rows-- > 0)
+      {
+         if (image[-2] != 190 || image[-1] != 239)
+            png_error(pp, "row start overwritten");
+         if (image[cbRow] != 222 || image[cbRow+1] != 173 ||
+            image[cbRow+2] != 17)
+            png_error(pp, "row end overwritten");
+         image += cbRow+5;
+      }
+   }
+}
+static void
+store_write(png_structp pp, png_bytep pb, png_size_t st)
+{
+   png_store *ps = voidcast(png_store*, png_get_io_ptr(pp));
+   if (ps->pwrite != pp)
+      png_error(pp, "store state damaged");
+   while (st > 0)
+   {
+      size_t cb;
+      if (ps->writepos >= STORE_BUFFER_SIZE)
+         store_storenew(ps);
+      cb = st;
+      if (cb > STORE_BUFFER_SIZE - ps->writepos)
+         cb = STORE_BUFFER_SIZE - ps->writepos;
+      memcpy(ps->new.buffer + ps->writepos, pb, cb);
+      pb += cb;
+      st -= cb;
+      ps->writepos += cb;
+   }
+}
+static void
+store_flush(png_structp pp)
+{
+   UNUSED(pp) /*DOES NOTHING*/
+}
+static size_t
+store_read_buffer_size(png_store *ps)
+{
+   /* Return the bytes available for read in the current buffer. */
+   if (ps->next != &ps->current->data)
+      return STORE_BUFFER_SIZE;
+   return ps->current->datacount;
+}
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+/* Return total bytes available for read. */
+static size_t
+store_read_buffer_avail(png_store *ps)
+{
+   if (ps->current != NULL && ps->next != NULL)
+   {
+      png_store_buffer *next = &ps->current->data;
+      size_t cbAvail = ps->current->datacount;
+      while (next != ps->next && next != NULL)
+      {
+         next = next->prev;
+         cbAvail += STORE_BUFFER_SIZE;
+      }
+      if (next != ps->next)
+         png_error(ps->pread, "buffer read error");
+      if (cbAvail > ps->readpos)
+         return cbAvail - ps->readpos;
+   }
+   return 0;
+}
+#endif
+static int
+store_read_buffer_next(png_store *ps)
+{
+   png_store_buffer *pbOld = ps->next;
+   png_store_buffer *pbNew = &ps->current->data;
+   if (pbOld != pbNew)
+   {
+      while (pbNew != NULL && pbNew->prev != pbOld)
+         pbNew = pbNew->prev;
+      if (pbNew != NULL)
+      {
+         ps->next = pbNew;
+         ps->readpos = 0;
+         return 1;
+      }
+      png_error(ps->pread, "buffer lost");
+   }
+   return 0; /* EOF or error */
+}
+/* Need separate implementation and callback to allow use of the same code
+ * during progressive read, where the io_ptr is set internally by libpng.
+ */
+static void
+store_read_imp(png_store *ps, png_bytep pb, png_size_t st)
+{
+   if (ps->current == NULL || ps->next == NULL)
+      png_error(ps->pread, "store state damaged");
+   while (st > 0)
+   {
+      size_t cbAvail = store_read_buffer_size(ps) - ps->readpos;
+      if (cbAvail > 0)
+      {
+         if (cbAvail > st) cbAvail = st;
+         memcpy(pb, ps->next->buffer + ps->readpos, cbAvail);
+         st -= cbAvail;
+         pb += cbAvail;
+         ps->readpos += cbAvail;
+      }
+      else if (!store_read_buffer_next(ps))
+         png_error(ps->pread, "read beyond end of file");
+   }
+}
+static void
+store_read(png_structp pp, png_bytep pb, png_size_t st)
+{
+   png_store *ps = voidcast(png_store*, png_get_io_ptr(pp));
+   if (ps == NULL || ps->pread != pp)
+      png_error(pp, "bad store read call");
+   store_read_imp(ps, pb, st);
+}
+static void
+store_progressive_read(png_store *ps, png_structp pp, png_infop pi)
+{
+   /* Notice that a call to store_read will cause this function to fail because
+    * readpos will be set.
+    */
+   if (ps->pread != pp || ps->current == NULL || ps->next == NULL)
+      png_error(pp, "store state damaged (progressive)");
+   do
+   {
+      if (ps->readpos != 0)
+         png_error(pp, "store_read called during progressive read");
+      png_process_data(pp, pi, ps->next->buffer, store_read_buffer_size(ps));
+   }
+   while (store_read_buffer_next(ps));
+}
+/* The caller must fill this in: */
+static store_palette_entry *
+store_write_palette(png_store *ps, int npalette)
+{
+   if (ps->pwrite == NULL)
+      store_log(ps, NULL, "attempt to write palette without write stream", 1);
+   if (ps->palette != NULL)
+      png_error(ps->pwrite, "multiple store_write_palette calls");
+   /* This function can only return NULL if called with '0'! */
+   if (npalette > 0)
+   {
+      ps->palette = voidcast(store_palette_entry*, malloc(npalette *
+         sizeof *ps->palette));
+      if (ps->palette == NULL)
+         png_error(ps->pwrite, "store new palette: OOM");
+      ps->npalette = npalette;
+   }
+   return ps->palette;
+}
+static store_palette_entry *
+store_current_palette(png_store *ps, int *npalette)
+{
+   /* This is an internal error (the call has been made outside a read
+    * operation.)
+    */
+   if (ps->current == NULL)
+      store_log(ps, ps->pread, "no current stream for palette", 1);
+   /* The result may be null if there is no palette. */
+   *npalette = ps->current->npalette;
+   return ps->current->palette;
+}
+/***************************** MEMORY MANAGEMENT*** ***************************/
+/* A store_memory is simply the header for an allocated block of memory.  The
+ * pointer returned to libpng is just after the end of the header block, the
+ * allocated memory is followed by a second copy of the 'mark'.
+ */
+typedef struct store_memory
+{
+   store_pool          *pool;    /* Originating pool */
+   struct store_memory *next;    /* Singly linked list */
+   png_alloc_size_t     size;    /* Size of memory allocated */
+   png_byte             mark[4]; /* ID marker */
+} store_memory;
+/* Handle a fatal error in memory allocation.  This calls png_error if the
+ * libpng struct is non-NULL, else it outputs a message and returns.  This means
+ * that a memory problem while libpng is running will abort (png_error) the
+ * handling of particular file while one in cleanup (after the destroy of the
+ * struct has returned) will simply keep going and free (or attempt to free)
+ * all the memory.
+ */
+static void
+store_pool_error(png_store *ps, png_structp pp, PNG_CONST char *msg)
+{
+   if (pp != NULL)
+      png_error(pp, msg);
+   /* Else we have to do it ourselves.  png_error eventually calls store_log,
+    * above.  store_log accepts a NULL png_structp - it just changes what gets
+    * output by store_message.
+    */
+   store_log(ps, pp, msg, 1 /* error */);
+}
+static void
+store_memory_free(png_structp pp, store_pool *pool, store_memory *memory)
+{
+   /* Note that pp may be NULL (see store_pool_delete below), the caller has
+    * found 'memory' in pool->list *and* unlinked this entry, so this is a valid
+    * pointer (for sure), but the contents may have been trashed.
+    */
+   if (memory->pool != pool)
+      store_pool_error(pool->store, pp, "memory corrupted (pool)");
+   else if (memcmp(memory->mark, pool->mark, sizeof memory->mark) != 0)
+      store_pool_error(pool->store, pp, "memory corrupted (start)");
+   /* It should be safe to read the size field now. */
+   else
+   {
+      png_alloc_size_t cb = memory->size;
+      if (cb > pool->max)
+         store_pool_error(pool->store, pp, "memory corrupted (size)");
+      else if (memcmp((png_bytep)(memory+1)+cb, pool->mark, sizeof pool->mark)
+         != 0)
+         store_pool_error(pool->store, pp, "memory corrupted (end)");
+      /* Finally give the library a chance to find problems too: */
+      else
+         {
+         pool->current -= cb;
+         free(memory);
+         }
+   }
+}
+static void
+store_pool_delete(png_store *ps, store_pool *pool)
+{
+   if (pool->list != NULL)
+   {
+      fprintf(stderr, "%s: %s %s: memory lost (list follows):\n", ps->test,
+         pool == &ps->read_memory_pool ? "read" : "write",
+         pool == &ps->read_memory_pool ? (ps->current != NULL ?
+            ps->current->name : "unknown file") : ps->wname);
+      ++ps->nerrors;
+      do
+      {
+         store_memory *next = pool->list;
+         pool->list = next->next;
+         next->next = NULL;
+         fprintf(stderr, "\t%lu bytes @ %p\n",
+             (unsigned long)next->size, (PNG_CONST void*)(next+1));
+         /* The NULL means this will always return, even if the memory is
+          * corrupted.
+          */
+         store_memory_free(NULL, pool, next);
+      }
+      while (pool->list != NULL);
+   }
+   /* And reset the other fields too for the next time. */
+   if (pool->max > pool->max_max) pool->max_max = pool->max;
+   pool->max = 0;
+   if (pool->current != 0) /* unexpected internal error */
+      fprintf(stderr, "%s: %s %s: memory counter mismatch (internal error)\n",
+         ps->test, pool == &ps->read_memory_pool ? "read" : "write",
+         pool == &ps->read_memory_pool ? (ps->current != NULL ?
+            ps->current->name : "unknown file") : ps->wname);
+   pool->current = 0;
+   if (pool->limit > pool->max_limit)
+      pool->max_limit = pool->limit;
+   pool->limit = 0;
+   if (pool->total > pool->max_total)
+      pool->max_total = pool->total;
+   pool->total = 0;
+   /* Get a new mark too. */
+   store_pool_mark(pool->mark);
+}
+/* The memory callbacks: */
+static png_voidp
+store_malloc(png_structp pp, png_alloc_size_t cb)
+{
+   store_pool *pool = voidcast(store_pool*, png_get_mem_ptr(pp));
+   store_memory *new = voidcast(store_memory*, malloc(cb + (sizeof *new) +
+      (sizeof pool->mark)));
+   if (new != NULL)
+   {
+      if (cb > pool->max)
+         pool->max = cb;
+      pool->current += cb;
+      if (pool->current > pool->limit)
+         pool->limit = pool->current;
+      pool->total += cb;
+      new->size = cb;
+      memcpy(new->mark, pool->mark, sizeof new->mark);
+      memcpy((png_byte*)(new+1) + cb, pool->mark, sizeof pool->mark);
+      new->pool = pool;
+      new->next = pool->list;
+      pool->list = new;
+      ++new;
+   }
+   else
+   {
+      /* NOTE: the PNG user malloc function cannot use the png_ptr it is passed
+       * other than to retrieve the allocation pointer!  libpng calls the
+       * store_malloc callback in two basic cases:
+       *
+       * 1) From png_malloc; png_malloc will do a png_error itself if NULL is
+       *    returned.
+       * 2) From png_struct or png_info structure creation; png_malloc is
+       *    to return so cleanup can be performed.
+       *
+       * To handle this store_malloc can log a message, but can't do anything
+       * else.
+       */
+      store_log(pool->store, pp, "out of memory", 1 /* is_error */);
+   }
+   return new;
+}
+static void
+store_free(png_structp pp, png_voidp memory)
+{
+   store_pool *pool = voidcast(store_pool*, png_get_mem_ptr(pp));
+   store_memory *this = voidcast(store_memory*, memory), **test;
+   /* Because libpng calls store_free with a dummy png_struct when deleting
+    * png_struct or png_info via png_destroy_struct_2 it is necessary to check
+    * the passed in png_structp to ensure it is valid, and not pass it to
+    * png_error if it is not.
+    */
+   if (pp != pool->store->pread && pp != pool->store->pwrite)
+      pp = NULL;
+   /* First check that this 'memory' really is valid memory - it must be in the
+    * pool list.  If it is, use the shared memory_free function to free it.
+    */
+   --this;
+   for (test = &pool->list; *test != this; test = &(*test)->next)
+   {
+      if (*test == NULL)
+      {
+         store_pool_error(pool->store, pp, "bad pointer to free");
+         return;
+      }
+   }
+   /* Unlink this entry, *test == this. */
+   *test = this->next;
+   this->next = NULL;
+   store_memory_free(pp, pool, this);
+}
+/* Setup functions. */
+/* Cleanup when aborting a write or after storing the new file. */
+static void
+store_write_reset(png_store *ps)
+{
+   if (ps->pwrite != NULL)
+   {
+      anon_context(ps);
+      Try
+         png_destroy_write_struct(&ps->pwrite, &ps->piwrite);
+      Catch_anonymous
+      {
+         /* memory corruption: continue. */
+      }
+      ps->pwrite = NULL;
+      ps->piwrite = NULL;
+   }
+   /* And make sure that all the memory has been freed - this will output
+    * spurious errors in the case of memory corruption above, but this is safe.
+    */
+   store_pool_delete(ps, &ps->write_memory_pool);
+   store_freenew(ps);
+}
+/* The following is the main write function, it returns a png_struct and,
+ * optionally, a png_info suitable for writiing a new PNG file.  Use
+ * store_storefile above to record this file after it has been written.  The
+ * returned libpng structures as destroyed by store_write_reset above.
+ */
+static png_structp
+set_store_for_write(png_store *ps, png_infopp ppi,
+   PNG_CONST char * volatile name)
+{
+   anon_context(ps);
+   Try
+   {
+      if (ps->pwrite != NULL)
+         png_error(ps->pwrite, "write store already in use");
+      store_write_reset(ps);
+      safecat(ps->wname, sizeof ps->wname, 0, name);
+      /* Don't do the slow memory checks if doing a speed test. */
+      if (ps->speed)
+         ps->pwrite = png_create_write_struct(PNG_LIBPNG_VER_STRING,
+            ps, store_error, store_warning);
+      else
+         ps->pwrite = png_create_write_struct_2(PNG_LIBPNG_VER_STRING,
+            ps, store_error, store_warning, &ps->write_memory_pool,
+            store_malloc, store_free);
+      png_set_write_fn(ps->pwrite, ps, store_write, store_flush);
+      if (ppi != NULL)
+         *ppi = ps->piwrite = png_create_info_struct(ps->pwrite);
+   }
+   Catch_anonymous
+      return NULL;
+   return ps->pwrite;
+}
+/* Cleanup when finished reading (either due to error or in the success case).
+ */
+static void
+store_read_reset(png_store *ps)
+{
+   if (ps->pread != NULL)
+   {
+      anon_context(ps);
+      Try
+         png_destroy_read_struct(&ps->pread, &ps->piread, NULL);
+      Catch_anonymous
+      {
+         /* error already output: continue */
+      }
+      ps->pread = NULL;
+      ps->piread = NULL;
+   }
+   /* Always do this to be safe. */
+   store_pool_delete(ps, &ps->read_memory_pool);
+   ps->current = NULL;
+   ps->next = NULL;
+   ps->readpos = 0;
+   ps->validated = 0;
+}
+static void
+store_read_set(png_store *ps, png_uint_32 id)
+{
+   png_store_file *pf = ps->saved;
+   while (pf != NULL)
+   {
+      if (pf->id == id)
+      {
+         ps->current = pf;
+         ps->next = NULL;
+         store_read_buffer_next(ps);
+         return;
+      }
+      pf = pf->next;
+   }
+      {
+      size_t pos;
+      char msg[FILE_NAME_SIZE+64];
+      pos = standard_name_from_id(msg, sizeof msg, 0, id);
+      pos = safecat(msg, sizeof msg, pos, ": file not found");
+      png_error(ps->pread, msg);
+      }
+}
+/* The main interface for reading a saved file - pass the id number of the file
+ * to retrieve.  Ids must be unique or the earlier file will be hidden.  The API
+ * returns a png_struct and, optionally, a png_info.  Both of these will be
+ * destroyed by store_read_reset above.
+ */
+static png_structp
+set_store_for_read(png_store *ps, png_infopp ppi, png_uint_32 id,
+   PNG_CONST char *name)
+{
+   /* Set the name for png_error */
+   safecat(ps->test, sizeof ps->test, 0, name);
+   if (ps->pread != NULL)
+      png_error(ps->pread, "read store already in use");
+   store_read_reset(ps);
+   /* Both the create APIs can return NULL if used in their default mode
+    * (because there is no other way of handling an error because the jmp_buf
+    * by default is stored in png_struct and that has not been allocated!)
+    * However, given that store_error works correctly in these circumstances
+    * we don't ever expect NULL in this program.
+    */
+   if (ps->speed)
+      ps->pread = png_create_read_struct(PNG_LIBPNG_VER_STRING, ps,
+          store_error, store_warning);
+   else
+      ps->pread = png_create_read_struct_2(PNG_LIBPNG_VER_STRING, ps,
+          store_error, store_warning, &ps->read_memory_pool, store_malloc,
+          store_free);
+   if (ps->pread == NULL)
+   {
+      struct exception_context *the_exception_context = &ps->exception_context;
+      store_log(ps, NULL, "png_create_read_struct returned NULL (unexpected)",
+         1 /*error*/);
+      Throw ps;
+   }
+   store_read_set(ps, id);
+   if (ppi != NULL)
+      *ppi = ps->piread = png_create_info_struct(ps->pread);
+   return ps->pread;
+}
+/* The overall cleanup of a store simply calls the above then removes all the
+ * saved files.  This does not delete the store itself.
+ */
+static void
+store_delete(png_store *ps)
+{
+   store_write_reset(ps);
+   store_read_reset(ps);
+   store_freefile(&ps->saved);
+   store_image_free(ps, NULL);
+}
+/*********************** PNG FILE MODIFICATION ON READ ************************/
+/* Files may be modified on read.  The following structure contains a complete
+ * png_store together with extra members to handle modification and a special
+ * read callback for libpng.  To use this the 'modifications' field must be set
+ * to a list of png_modification structures that actually perform the
+ * modification, otherwise a png_modifier is functionally equivalent to a
+ * png_store.  There is a special read function, set_modifier_for_read, which
+ * replaces set_store_for_read.
+ */
+typedef enum modifier_state
+{
+   modifier_start,                        /* Initial value */
+   modifier_signature,                    /* Have a signature */
+   modifier_IHDR                          /* Have an IHDR */
+} modifier_state;
+typedef struct CIE_color
+{
+   /* A single CIE tristimulus value, representing the unique response of a
+    * standard observer to a variety of light spectra.  The observer recognizes
+    * all spectra that produce this response as the same color, therefore this
+    * is effectively a description of a color.
+    */
+   double X, Y, Z;
+} CIE_color;
+static double
+chromaticity_x(CIE_color c)
+{
+   return c.X / (c.X + c.Y + c.Z);
+}
+static double
+chromaticity_y(CIE_color c)
+{
+   return c.Y / (c.X + c.Y + c.Z);
+}
+typedef struct color_encoding
+{
+   /* A description of an (R,G,B) encoding of color (as defined above); this
+    * includes the actual colors of the (R,G,B) triples (1,0,0), (0,1,0) and
+    * (0,0,1) plus an encoding value that is used to encode the linear
+    * components R, G and B to give the actual values R^gamma, G^gamma and
+    * B^gamma that are stored.
+    */
+   double    gamma;            /* Encoding (file) gamma of space */
+   CIE_color red, green, blue; /* End points */
+} color_encoding;
+static CIE_color
+white_point(PNG_CONST color_encoding *encoding)
+{
+   CIE_color white;
+   
+   white.X = encoding->red.X + encoding->green.X + encoding->blue.X;
+   white.Y = encoding->red.Y + encoding->green.Y + encoding->blue.Y;
+   white.Z = encoding->red.Z + encoding->green.Z + encoding->blue.Z;
+   return white;
+}
+static void
+normalize_color_encoding(color_encoding *encoding)
+{
+   PNG_CONST double whiteY = encoding->red.Y + encoding->green.Y +
+      encoding->blue.Y;
+   if (whiteY != 1)
+   {
+      encoding->red.X /= whiteY;
+      encoding->red.Y /= whiteY;
+      encoding->red.Z /= whiteY;
+      encoding->green.X /= whiteY;
+      encoding->green.Y /= whiteY;
+      encoding->green.Z /= whiteY;
+      encoding->blue.X /= whiteY;
+      encoding->blue.Y /= whiteY;
+      encoding->blue.Z /= whiteY;
+   }
+}
+static size_t
+safecat_color_encoding(char *buffer, size_t bufsize, size_t pos,
+   PNG_CONST color_encoding *e, double encoding_gamma)
+{
+   if (e != 0)
+   {
+      if (encoding_gamma != 0)
+         pos = safecat(buffer, bufsize, pos, "(");
+      pos = safecat(buffer, bufsize, pos, "R(");
+      pos = safecatd(buffer, bufsize, pos, e->red.X, 4);
+      pos = safecat(buffer, bufsize, pos, ",");
+      pos = safecatd(buffer, bufsize, pos, e->red.Y, 4);
+      pos = safecat(buffer, bufsize, pos, ",");
+      pos = safecatd(buffer, bufsize, pos, e->red.Z, 4);
+      pos = safecat(buffer, bufsize, pos, "),G(");
+      pos = safecatd(buffer, bufsize, pos, e->green.X, 4);
+      pos = safecat(buffer, bufsize, pos, ",");
+      pos = safecatd(buffer, bufsize, pos, e->green.Y, 4);
+      pos = safecat(buffer, bufsize, pos, ",");
+      pos = safecatd(buffer, bufsize, pos, e->green.Z, 4);
+      pos = safecat(buffer, bufsize, pos, "),B(");
+      pos = safecatd(buffer, bufsize, pos, e->blue.X, 4);
+      pos = safecat(buffer, bufsize, pos, ",");
+      pos = safecatd(buffer, bufsize, pos, e->blue.Y, 4);
+      pos = safecat(buffer, bufsize, pos, ",");
+      pos = safecatd(buffer, bufsize, pos, e->blue.Z, 4);
+      pos = safecat(buffer, bufsize, pos, ")");
+      if (encoding_gamma != 0)
+         pos = safecat(buffer, bufsize, pos, ")");
+   }
+   if (encoding_gamma != 0)
+   {
+      pos = safecat(buffer, bufsize, pos, "^");
+      pos = safecatd(buffer, bufsize, pos, encoding_gamma, 5);
+   }
+   return pos;
+}
+typedef struct png_modifier
+{
+   png_store               this;             /* I am a png_store */
+   struct png_modification *modifications;   /* Changes to make */
+   modifier_state           state;           /* My state */
+   /* Information from IHDR: */
+   png_byte                 bit_depth;       /* From IHDR */
+   png_byte                 colour_type;     /* From IHDR */
+   /* While handling PLTE, IDAT and IEND these chunks may be pended to allow
+    * other chunks to be inserted.
+    */
+   png_uint_32              pending_len;
+   png_uint_32              pending_chunk;
+   /* Test values */
+   double                   *gammas;
+   unsigned int              ngammas;
+   unsigned int              ngamma_tests;     /* Number of gamma tests to run*/
+   double                    current_gamma;    /* 0 if not set */
+   PNG_CONST color_encoding *encodings;
+   unsigned int              nencodings;
+   PNG_CONST color_encoding *current_encoding; /* If an encoding has been set */
+   unsigned int              encoding_counter; /* For iteration */
+   int                       encoding_ignored; /* Something overwrote it */
+   /* Control variables used to iterate through possible encodings, the
+    * following must be set to 0 and tested by the function that uses the
+    * png_modifier because the modifier only sets it to 1 (true.)
+    */
+   unsigned int              repeat :1;   /* Repeat this transform test. */
+   unsigned int              test_uses_encoding :1;
+   /* Lowest sbit to test (libpng fails for sbit < 8) */
+   png_byte                 sbitlow;
+   /* Error control - these are the limits on errors accepted by the gamma tests
+    * below.
+    */
+   double                   maxout8;  /* Maximum output value error */
+   double                   maxabs8;  /* Absolute sample error 0..1 */
+   double                   maxcalc8; /* Absolute sample error 0..1 */
+   double                   maxpc8;   /* Percentage sample error 0..100% */
+   double                   maxout16; /* Maximum output value error */
+   double                   maxabs16; /* Absolute sample error 0..1 */
+   double                   maxcalc16;/* Absolute sample error 0..1 */
+   double                   maxpc16;  /* Percentage sample error 0..100% */
+   /* This is set by transforms that need to allow a higher limit, it is an
+    * internal check on pngvalid to ensure that the calculated error limits are
+    * not ridiculous; without this it is too easy to make a mistake in pngvalid
+    * that allows any value through.
+    */
+   double                   limit;    /* limit on error values, normally 4E-3 */
+   /* Log limits - values above this are logged, but not necessarily
+    * warned.
+    */
+   double                   log8;     /* Absolute error in 8 bits to log */
+   double                   log16;    /* Absolute error in 16 bits to log */
+   /* Logged 8 and 16 bit errors ('output' values): */
+   double                   error_gray_2;
+   double                   error_gray_4;
+   double                   error_gray_8;
+   double                   error_gray_16;
+   double                   error_color_8;
+   double                   error_color_16;
+   double                   error_indexed;
+   /* Flags: */
+   /* Whether to call png_read_update_info, not png_read_start_image, and how
+    * many times to call it.
+    */
+   int                      use_update_info;
+   /* Whether or not to interlace. */
+   int                      interlace_type :9; /* int, but must store '1' */
+   /* Run the standard tests? */
+   unsigned int             test_standard :1;
+   /* Run the odd-sized image and interlace read/write tests? */
+   unsigned int             test_size :1;
+   /* Run tests on reading with a combiniation of transforms, */
+   unsigned int             test_transform :1;
+   /* When to use the use_input_precision option: */
+   unsigned int             use_input_precision :1;
+   unsigned int             use_input_precision_sbit :1;
+   unsigned int             use_input_precision_16to8 :1;
+   /* If set assume that the calculation bit depth is set by the input
+    * precision, not the output precision.
+    */
+   unsigned int             calculations_use_input_precision :1;
+   /* If set assume that the calculations are done in 16 bits even if both input
+    * and output are 8 bit or less.
+    */
+   unsigned int             assume_16_bit_calculations :1;
+   /* Which gamma tests to run: */
+   unsigned int             test_gamma_threshold :1;
+   unsigned int             test_gamma_transform :1; /* main tests */
+   unsigned int             test_gamma_sbit :1;
+   unsigned int             test_gamma_scale16 :1;
+   unsigned int             test_gamma_background :1;
+   unsigned int             test_gamma_alpha_mode :1;
+   unsigned int             test_gamma_expand16 :1;
+   unsigned int             test_exhaustive :1;
+   unsigned int             log :1;   /* Log max error */
+   /* Buffer information, the buffer size limits the size of the chunks that can
+    * be modified - they must fit (including header and CRC) into the buffer!
+    */
+   size_t                   flush;           /* Count of bytes to flush */
+   size_t                   buffer_count;    /* Bytes in buffer */
+   size_t                   buffer_position; /* Position in buffer */
+   png_byte                 buffer[1024];
+} png_modifier;
+/* This returns true if the test should be stopped now because it has already
+ * failed and it is running silently.
+ */
+static int fail(png_modifier *pm)
+{
+   return !pm->log && !pm->this.verbose && (pm->this.nerrors > 0 ||
+       (pm->this.treat_warnings_as_errors && pm->this.nwarnings > 0));
+}
+static void
+modifier_init(png_modifier *pm)
+{
+   memset(pm, 0, sizeof *pm);
+   store_init(&pm->this);
+   pm->modifications = NULL;
+   pm->state = modifier_start;
+   pm->sbitlow = 1U;
+   pm->ngammas = 0;
+   pm->ngamma_tests = 0;
+   pm->gammas = 0;
+   pm->current_gamma = 0;
+   pm->encodings = 0;
+   pm->nencodings = 0;
+   pm->current_encoding = 0;
+   pm->encoding_counter = 0;
+   pm->encoding_ignored = 0;
+   pm->repeat = 0;
+   pm->test_uses_encoding = 0;
+   pm->maxout8 = pm->maxpc8 = pm->maxabs8 = pm->maxcalc8 = 0;
+   pm->maxout16 = pm->maxpc16 = pm->maxabs16 = pm->maxcalc16 = 0;
+   pm->limit = 4E-3;
+   pm->log8 = pm->log16 = 0; /* Means 'off' */
+   pm->error_gray_2 = pm->error_gray_4 = pm->error_gray_8 = 0;
+   pm->error_gray_16 = pm->error_color_8 = pm->error_color_16 = 0;
+   pm->error_indexed = 0;
+   pm->use_update_info = 0;
+   pm->interlace_type = PNG_INTERLACE_NONE;
+   pm->test_standard = 0;
+   pm->test_size = 0;
+   pm->test_transform = 0;
+   pm->use_input_precision = 0;
+   pm->use_input_precision_sbit = 0;
+   pm->use_input_precision_16to8 = 0;
+   pm->calculations_use_input_precision = 0;
+   pm->test_gamma_threshold = 0;
+   pm->test_gamma_transform = 0;
+   pm->test_gamma_sbit = 0;
+   pm->test_gamma_scale16 = 0;
+   pm->test_gamma_background = 0;
+   pm->test_gamma_alpha_mode = 0;
+   pm->test_gamma_expand16 = 0;
+   pm->test_exhaustive = 0;
+   pm->log = 0;
+   /* Rely on the memset for all the other fields - there are no pointers */
+}
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+/* If pm->calculations_use_input_precision is set then operations will happen
+ * with only 8 bit precision unless both the input and output bit depth are 16.
+ *
+ * If pm->assume_16_bit_calculations is set then even 8 bit calculations use 16
+ * bit precision.  This only affects those of the following limits that pertain
+ * to a calculation - not a digitization operation - unless the following API is
+ * called directly.
+ */
+static double digitize(PNG_CONST png_modifier *pm, double value,
+   int sample_depth, int do_round)
+{
+   /* 'value' is in the range 0 to 1, the result is the same value rounded to a
+    * multiple of the digitization factor - 8 or 16 bits depending on both the
+    * sample depth and the 'assume' setting.  Digitization is normally by
+    * rounding and 'do_round' should be 1, if it is 0 the digitized value will
+    * be truncated.
+    */
+   PNG_CONST unsigned int digitization_factor =
+      (pm->assume_16_bit_calculations || sample_depth == 16) ? 65535 : 255;
+   /* Limiting the range is done as a convenience to the caller - it's easier to
+    * do it once here than every time at the call site.
+    */
+   if (value <= 0)
+      value = 0;
+   else if (value >= 1)
+      value = 1;
+   value *= digitization_factor;
+   if (do_round) value += .5;
+   return floor(value)/digitization_factor;
+}
+static double abserr(PNG_CONST png_modifier *pm, int in_depth, int out_depth)
+{
+   /* Absolute error permitted in linear values - affected by the bit depth of
+    * the calculations.
+    */
+   if (pm->assume_16_bit_calculations || (out_depth == 16 && (in_depth == 16 ||
+      !pm->calculations_use_input_precision)))
+      return pm->maxabs16;
+   else
+      return pm->maxabs8;
+}
+static double calcerr(PNG_CONST png_modifier *pm, int in_depth, int out_depth)
+{
+   /* Error in the linear composition arithmetic - only relevant when
+    * composition actually happens (0 < alpha < 1).
+    */
+   if (pm->assume_16_bit_calculations || (out_depth == 16 && (in_depth == 16 ||
+      !pm->calculations_use_input_precision)))
+      return pm->maxcalc16;
+   else
+      return pm->maxcalc8;
+}
+static double pcerr(PNG_CONST png_modifier *pm, int in_depth, int out_depth)
+{
+   /* Percentage error permitted in the linear values.  Note that the specified
+    * value is a percentage but this routine returns a simple number.
+    */
+   if (pm->assume_16_bit_calculations || (out_depth == 16 && (in_depth == 16 ||
+      !pm->calculations_use_input_precision)))
+      return pm->maxpc16 * .01;
+   else
+      return pm->maxpc8 * .01;
+}
+/* Output error - the error in the encoded value.  This is determined by the
+ * digitization of the output so can be +/-0.5 in the actual output value.  In
+ * the expand_16 case with the current code in libpng the expand happens after
+ * all the calculations are done in 8 bit arithmetic, so even though the output
+ * depth is 16 the output error is determined by the 8 bit calculation.
+ *
+ * This limit is not determined by the bit depth of internal calculations.
+ *
+ * The specified parameter does *not* include the base .5 digitization error but
+ * it is added here.
+ */
+static double outerr(PNG_CONST png_modifier *pm, int in_depth, int out_depth)
+{
+   /* There is a serious error in the 2 and 4 bit grayscale transform because
+    * the gamma table value (8 bits) is simply shifted, not rounded, so the
+    * error in 4 bit grayscale gamma is up to the value below.  This is a hack
+    * to allow pngvalid to succeed:
+    *
+    * TODO: fix this in libpng
+    */
+   if (out_depth == 2)
+      return .73182-.5;
+   if (out_depth == 4)
+      return .90644-.5;
+   if (out_depth == 16 && (in_depth == 16 ||
+      !pm->calculations_use_input_precision))
+      return pm->maxout16;
+   /* This is the case where the value was calculated at 8-bit precision then
+    * scaled to 16 bits.
+    */
+   else if (out_depth == 16)
+      return pm->maxout8 * 257;
+   else
+      return pm->maxout8;
+}
+/* This does the same thing as the above however it returns the value to log,
+ * rather than raising a warning.  This is useful for debugging to track down
+ * exactly what set of parameters cause high error values.
+ */
+static double outlog(PNG_CONST png_modifier *pm, int in_depth, int out_depth)
+{
+   /* The command line parameters are either 8 bit (0..255) or 16 bit (0..65535)
+    * and so must be adjusted for low bit depth grayscale:
+    */
+   if (out_depth <= 8)
+   {
+      if (pm->log8 == 0) /* switched off */
+         return 256;
+      if (out_depth < 8)
+         return pm->log8 / 255 * ((1<<out_depth)-1);
+      return pm->log8;
+   }
+   if (out_depth == 16 && (in_depth == 16 ||
+      !pm->calculations_use_input_precision))
+   {
+      if (pm->log16 == 0)
+         return 65536;
+      return pm->log16;
+   }
+   /* This is the case where the value was calculated at 8-bit precision then
+    * scaled to 16 bits.
+    */
+   if (pm->log8 == 0)
+      return 65536;
+   return pm->log8 * 257;
+}
+/* This complements the above by providing the appropriate quantization for the
+ * final value.  Normally this would just be quantization to an integral value,
+ * but in the 8 bit calculation case it's actually quantization to a multiple of
+ * 257!
+ */
+static int output_quantization_factor(PNG_CONST png_modifier *pm, int in_depth,
+   int out_depth)
+{
+   if (out_depth == 16 && in_depth != 16
+      && pm->calculations_use_input_precision)
+      return 257;
+   else
+      return 1;
+}
+/* One modification structure must be provided for each chunk to be modified (in
+ * fact more than one can be provided if multiple separate changes are desired
+ * for a single chunk.)  Modifications include adding a new chunk when a
+ * suitable chunk does not exist.
+ *
+ * The caller of modify_fn will reset the CRC of the chunk and record 'modified'
+ * or 'added' as appropriate if the modify_fn returns 1 (true).  If the
+ * modify_fn is NULL the chunk is simply removed.
+ */
+typedef struct png_modification
+{
+   struct png_modification *next;
+   png_uint_32              chunk;
+   /* If the following is NULL all matching chunks will be removed: */
+   int                    (*modify_fn)(struct png_modifier *pm,
+                               struct png_modification *me, int add);
+   /* If the following is set to PLTE, IDAT or IEND and the chunk has not been
+    * found and modified (and there is a modify_fn) the modify_fn will be called
+    * to add the chunk before the relevant chunk.
+    */
+   png_uint_32              add;
+   unsigned int             modified :1;     /* Chunk was modified */
+   unsigned int             added    :1;     /* Chunk was added */
+   unsigned int             removed  :1;     /* Chunk was removed */
+} png_modification;
+static void
+modification_reset(png_modification *pmm)
+{
+   if (pmm != NULL)
+   {
+      pmm->modified = 0;
+      pmm->added = 0;
+      pmm->removed = 0;
+      modification_reset(pmm->next);
+   }
+}
+static void
+modification_init(png_modification *pmm)
+{
+   memset(pmm, 0, sizeof *pmm);
+   pmm->next = NULL;
+   pmm->chunk = 0;
+   pmm->modify_fn = NULL;
+   pmm->add = 0;
+   modification_reset(pmm);
+}
+static void
+modifier_current_encoding(PNG_CONST png_modifier *pm, color_encoding *ce)
+{
+   if (pm->current_encoding != 0)
+      *ce = *pm->current_encoding;
+   else
+      memset(ce, 0, sizeof *ce);
+   ce->gamma = pm->current_gamma;
+}
+static size_t
+safecat_current_encoding(char *buffer, size_t bufsize, size_t pos,
+   PNG_CONST png_modifier *pm)
+{
+   pos = safecat_color_encoding(buffer, bufsize, pos, pm->current_encoding,
+      pm->current_gamma);
+   if (pm->encoding_ignored)
+      pos = safecat(buffer, bufsize, pos, "[overridden]");
+   return pos;
+}
+/* Iterate through the usefully testable color encodings.  An encoding is one
+ * of:
+ *
+ * 1) Nothing (no color space, no gamma).
+ * 2) Just a gamma value from the gamma array (including 1.0)
+ * 3) A color space from the encodings array with the corresponding gamma.
+ * 4) The same, but with gamma 1.0 (only really useful with 16 bit calculations)
+ *
+ * The iterator selects these in turn, the randomizer selects one at random,
+ * which is used depends on the setting of the 'test_exhaustive' flag.  Notice
+ * that this function changes the colour space encoding so it must only be
+ * called on completion of the previous test.  This is what 'modifier_reset'
+ * does, below.
+ *
+ * After the function has been called the 'repeat' flag will still be set; the
+ * caller of modifier_reset must reset it at the start of each run of the test!
+ */
+static unsigned int
+modifier_total_encodings(PNG_CONST png_modifier *pm)
+{
+   return 1 +                 /* (1) nothing */
+      pm->ngammas +           /* (2) gamma values to test */
+      pm->nencodings +        /* (3) total number of encodings */
+      /* The following test only works after the first time through the
+       * png_modifier code because 'bit_depth' is set when the IHDR is read.
+       * modifier_reset, below, preserves the setting until after it has called
+       * the iterate function (also below.)
+       *
+       * For this reason do not rely on this function outside a call to
+       * modifier_reset.
+       */
+      ((pm->bit_depth == 16 || pm->assume_16_bit_calculations) ?
+         pm->nencodings : 0); /* (4) encodings with gamma == 1.0 */
+}
+static void
+modifier_encoding_iterate(png_modifier *pm)
+{
+   if (!pm->repeat && /* Else something needs the current encoding again. */
+      pm->test_uses_encoding) /* Some transform is encoding dependent */
+   {
+      if (pm->test_exhaustive)
+      {
+         if (++pm->encoding_counter >= modifier_total_encodings(pm))
+            pm->encoding_counter = 0; /* This will stop the repeat */
+      }
+      else
+      {
+         /* Not exhaustive - choose an encoding at random; generate a number in
+          * the range 1..(max-1), so the result is always non-zero:
+          */
+         if (pm->encoding_counter == 0)
+            pm->encoding_counter = random_mod(modifier_total_encodings(pm)-1)+1;
+         else
+            pm->encoding_counter = 0;
+      }
+      if (pm->encoding_counter > 0)
+         pm->repeat = 1;
+   }
+   else if (!pm->repeat)
+      pm->encoding_counter = 0;
+}
+static void
+modifier_reset(png_modifier *pm)
+{
+   store_read_reset(&pm->this);
+   pm->limit = 4E-3;
+   pm->pending_len = pm->pending_chunk = 0;
+   pm->flush = pm->buffer_count = pm->buffer_position = 0;
+   pm->modifications = NULL;
+   pm->state = modifier_start;
+   modifier_encoding_iterate(pm);
+   /* The following must be set in the next run.  In particular
+    * test_uses_encodings must be set in the _ini function of each transform
+    * that looks at the encodings.  (Not the 'add' function!)
+    */
+   pm->test_uses_encoding = 0;
+   pm->current_gamma = 0;
+   pm->current_encoding = 0;
+   pm->encoding_ignored = 0;
+   /* These only become value after IHDR is read: */
+   pm->bit_depth = pm->colour_type = 0;
+}
+/* The following must be called before anything else to get the encoding set up
+ * on the modifier.  In particular it must be called before the transform init
+ * functions are called.
+ */
+static void
+modifier_set_encoding(png_modifier *pm)
+{
+   /* Set the encoding to the one specified by the current encoding counter,
+    * first clear out all the settings - this corresponds to an encoding_counter
+    * of 0.
+    */
+   pm->current_gamma = 0;
+   pm->current_encoding = 0;
+   pm->encoding_ignored = 0; /* not ignored yet - happens in _ini functions. */
+   /* Now, if required, set the gamma and encoding fields. */
+   if (pm->encoding_counter > 0)
+   {
+      /* The gammas[] array is an array of screen gammas, not encoding gammas,
+       * so we need the inverse:
+       */
+      if (pm->encoding_counter <= pm->ngammas)
+         pm->current_gamma = 1/pm->gammas[pm->encoding_counter-1];
+      else
+      {
+         unsigned int i = pm->encoding_counter - pm->ngammas;
+         if (i >= pm->nencodings)
+         {
+            i %= pm->nencodings;
+            pm->current_gamma = 1; /* Linear, only in the 16 bit case */
+         }
+         else
+            pm->current_gamma = pm->encodings[i].gamma;
+         pm->current_encoding = pm->encodings + i;
+      }
+   }
+}
+/* Enquiry functions to find out what is set.  Notice that there is an implicit
+ * assumption below that the first encoding in the list is the one for sRGB.
+ */
+static int
+modifier_color_encoding_is_sRGB(PNG_CONST png_modifier *pm)
+{
+   return pm->current_encoding != 0 && pm->current_encoding == pm->encodings &&
+      pm->current_encoding->gamma == pm->current_gamma;
+}
+static int
+modifier_color_encoding_is_set(PNG_CONST png_modifier *pm)
+{
+   return pm->current_gamma != 0;
+}
+/* Convenience macros. */
+#define CHUNK(a,b,c,d) (((a)<<24)+((b)<<16)+((c)<<8)+(d))
+#define CHUNK_IHDR CHUNK(73,72,68,82)
+#define CHUNK_PLTE CHUNK(80,76,84,69)
+#define CHUNK_IDAT CHUNK(73,68,65,84)
+#define CHUNK_IEND CHUNK(73,69,78,68)
+#define CHUNK_cHRM CHUNK(99,72,82,77)
+#define CHUNK_gAMA CHUNK(103,65,77,65)
+#define CHUNK_sBIT CHUNK(115,66,73,84)
+#define CHUNK_sRGB CHUNK(115,82,71,66)
+/* The guts of modification are performed during a read. */
+static void
+modifier_crc(png_bytep buffer)
+{
+   /* Recalculate the chunk CRC - a complete chunk must be in
+    * the buffer, at the start.
+    */
+   uInt datalen = png_get_uint_32(buffer);
+   uLong crc = crc32(0, buffer+4, datalen+4);
+   /* The cast to png_uint_32 is safe because a crc32 is always a 32 bit value.
+    */
+   png_save_uint_32(buffer+datalen+8, (png_uint_32)crc);
+}
+static void
+modifier_setbuffer(png_modifier *pm)
+{
+   modifier_crc(pm->buffer);
+   pm->buffer_count = png_get_uint_32(pm->buffer)+12;
+   pm->buffer_position = 0;
+}
+/* Separate the callback into the actual implementation (which is passed the
+ * png_modifier explicitly) and the callback, which gets the modifier from the
+ * png_struct.
+ */
+static void
+modifier_read_imp(png_modifier *pm, png_bytep pb, png_size_t st)
+{
+   while (st > 0)
+   {
+      size_t cb;
+      png_uint_32 len, chunk;
+      png_modification *mod;
+      if (pm->buffer_position >= pm->buffer_count) switch (pm->state)
+      {
+         static png_byte sign[8] = { 137, 80, 78, 71, 13, 10, 26, 10 };
+         case modifier_start:
+            store_read_imp(&pm->this, pm->buffer, 8); /* size of signature. */
+            pm->buffer_count = 8;
+            pm->buffer_position = 0;
+            if (memcmp(pm->buffer, sign, 8) != 0)
+               png_error(pm->this.pread, "invalid PNG file signature");
+            pm->state = modifier_signature;
+            break;
+         case modifier_signature:
+            store_read_imp(&pm->this, pm->buffer, 13+12); /* size of IHDR */
+            pm->buffer_count = 13+12;
+            pm->buffer_position = 0;
+            if (png_get_uint_32(pm->buffer) != 13 ||
+                png_get_uint_32(pm->buffer+4) != CHUNK_IHDR)
+               png_error(pm->this.pread, "invalid IHDR");
+            /* Check the list of modifiers for modifications to the IHDR. */
+            mod = pm->modifications;
+            while (mod != NULL)
+            {
+               if (mod->chunk == CHUNK_IHDR && mod->modify_fn &&
+                   (*mod->modify_fn)(pm, mod, 0))
+                  {
+                  mod->modified = 1;
+                  modifier_setbuffer(pm);
+                  }
+               /* Ignore removal or add if IHDR! */
+               mod = mod->next;
+            }
+            /* Cache information from the IHDR (the modified one.) */
+            pm->bit_depth = pm->buffer[8+8];
+            pm->colour_type = pm->buffer[8+8+1];
+            pm->state = modifier_IHDR;
+            pm->flush = 0;
+            break;
+         case modifier_IHDR:
+         default:
+            /* Read a new chunk and process it until we see PLTE, IDAT or
+             * IEND.  'flush' indicates that there is still some data to
+             * output from the preceding chunk.
+             */
+            if ((cb = pm->flush) > 0)
+            {
+               if (cb > st) cb = st;
+               pm->flush -= cb;
+               store_read_imp(&pm->this, pb, cb);
+               pb += cb;
+               st -= cb;
+               if (st == 0) return;
+            }
+            /* No more bytes to flush, read a header, or handle a pending
+             * chunk.
+             */
+            if (pm->pending_chunk != 0)
+            {
+               png_save_uint_32(pm->buffer, pm->pending_len);
+               png_save_uint_32(pm->buffer+4, pm->pending_chunk);
+               pm->pending_len = 0;
+               pm->pending_chunk = 0;
+            }
+            else
+               store_read_imp(&pm->this, pm->buffer, 8);
+            pm->buffer_count = 8;
+            pm->buffer_position = 0;
+            /* Check for something to modify or a terminator chunk. */
+            len = png_get_uint_32(pm->buffer);
+            chunk = png_get_uint_32(pm->buffer+4);
+            /* Terminators first, they may have to be delayed for added
+             * chunks
+             */
+            if (chunk == CHUNK_PLTE || chunk == CHUNK_IDAT ||
+                chunk == CHUNK_IEND)
+            {
+               mod = pm->modifications;
+               while (mod != NULL)
+               {
+                  if ((mod->add == chunk ||
+                      (mod->add == CHUNK_PLTE && chunk == CHUNK_IDAT)) &&
+                      mod->modify_fn != NULL && !mod->modified && !mod->added)
+                  {
+                     /* Regardless of what the modify function does do not run
+                      * this again.
+                      */
+                     mod->added = 1;
+                     if ((*mod->modify_fn)(pm, mod, 1 /*add*/))
+                     {
+                        /* Reset the CRC on a new chunk */
+                        if (pm->buffer_count > 0)
+                           modifier_setbuffer(pm);
+                        else
+                           {
+                           pm->buffer_position = 0;
+                           mod->removed = 1;
+                           }
+                        /* The buffer has been filled with something (we assume)
+                         * so output this.  Pend the current chunk.
+                         */
+                        pm->pending_len = len;
+                        pm->pending_chunk = chunk;
+                        break; /* out of while */
+                     }
+                  }
+                  mod = mod->next;
+               }
+               /* Don't do any further processing if the buffer was modified -
+                * otherwise the code will end up modifying a chunk that was
+                * just added.
+                */
+               if (mod != NULL)
+                  break; /* out of switch */
+            }
+            /* If we get to here then this chunk may need to be modified.  To
+             * do this it must be less than 1024 bytes in total size, otherwise
+             * it just gets flushed.
+             */
+            if (len+12 <= sizeof pm->buffer)
+            {
+               store_read_imp(&pm->this, pm->buffer+pm->buffer_count,
+                   len+12-pm->buffer_count);
+               pm->buffer_count = len+12;
+               /* Check for a modification, else leave it be. */
+               mod = pm->modifications;
+               while (mod != NULL)
+               {
+                  if (mod->chunk == chunk)
+                  {
+                     if (mod->modify_fn == NULL)
+                     {
+                        /* Remove this chunk */
+                        pm->buffer_count = pm->buffer_position = 0;
+                        mod->removed = 1;
+                        break; /* Terminate the while loop */
+                     }
+                     else if ((*mod->modify_fn)(pm, mod, 0))
+                     {
+                        mod->modified = 1;
+                        /* The chunk may have been removed: */
+                        if (pm->buffer_count == 0)
+                        {
+                           pm->buffer_position = 0;
+                           break;
+                        }
+                        modifier_setbuffer(pm);
+                     }
+                  }
+                  mod = mod->next;
+               }
+            }
+            else
+               pm->flush = len+12 - pm->buffer_count; /* data + crc */
+            /* Take the data from the buffer (if there is any). */
+            break;
+      }
+      /* Here to read from the modifier buffer (not directly from
+       * the store, as in the flush case above.)
+       */
+      cb = pm->buffer_count - pm->buffer_position;
+      if (cb > st)
+         cb = st;
+      memcpy(pb, pm->buffer + pm->buffer_position, cb);
+      st -= cb;
+      pb += cb;
+      pm->buffer_position += cb;
+   }
+}
+/* The callback: */
+static void
+modifier_read(png_structp pp, png_bytep pb, png_size_t st)
+{
+   png_modifier *pm = voidcast(png_modifier*, png_get_io_ptr(pp));
+   if (pm == NULL || pm->this.pread != pp)
+      png_error(pp, "bad modifier_read call");
+   modifier_read_imp(pm, pb, st);
+}
+/* Like store_progressive_read but the data is getting changed as we go so we
+ * need a local buffer.
+ */
+static void
+modifier_progressive_read(png_modifier *pm, png_structp pp, png_infop pi)
+{
+   if (pm->this.pread != pp || pm->this.current == NULL ||
+       pm->this.next == NULL)
+      png_error(pp, "store state damaged (progressive)");
+   /* This is another Horowitz and Hill random noise generator.  In this case
+    * the aim is to stress the progressive reader with truly horrible variable
+    * buffer sizes in the range 1..500, so a sequence of 9 bit random numbers
+    * is generated.  We could probably just count from 1 to 32767 and get as
+    * good a result.
+    */
+   for (;;)
+   {
+      static png_uint_32 noise = 1;
+      png_size_t cb, cbAvail;
+      png_byte buffer[512];
+      /* Generate 15 more bits of stuff: */
+      noise = (noise << 9) | ((noise ^ (noise >> (9-5))) & 0x1ff);
+      cb = noise & 0x1ff;
+      /* Check that this number of bytes are available (in the current buffer.)
+       * (This doesn't quite work - the modifier might delete a chunk; unlikely
+       * but possible, it doesn't happen at present because the modifier only
+       * adds chunks to standard images.)
+       */
+      cbAvail = store_read_buffer_avail(&pm->this);
+      if (pm->buffer_count > pm->buffer_position)
+         cbAvail += pm->buffer_count - pm->buffer_position;
+      if (cb > cbAvail)
+      {
+         /* Check for EOF: */
+         if (cbAvail == 0)
+            break;
+         cb = cbAvail;
+      }
+      modifier_read_imp(pm, buffer, cb);
+      png_process_data(pp, pi, buffer, cb);
+   }
+   /* Check the invariants at the end (if this fails it's a problem in this
+    * file!)
+    */
+   if (pm->buffer_count > pm->buffer_position ||
+       pm->this.next != &pm->this.current->data ||
+       pm->this.readpos < pm->this.current->datacount)
+      png_error(pp, "progressive read implementation error");
+}
+/* Set up a modifier. */
+static png_structp
+set_modifier_for_read(png_modifier *pm, png_infopp ppi, png_uint_32 id,
+    PNG_CONST char *name)
+{
+   /* Do this first so that the modifier fields are cleared even if an error
+    * happens allocating the png_struct.  No allocation is done here so no
+    * cleanup is required.
+    */
+   pm->state = modifier_start;
+   pm->bit_depth = 0;
+   pm->colour_type = 255;
+   pm->pending_len = 0;
+   pm->pending_chunk = 0;
+   pm->flush = 0;
+   pm->buffer_count = 0;
+   pm->buffer_position = 0;
+   return set_store_for_read(&pm->this, ppi, id, name);
+}
+/******************************** MODIFICATIONS *******************************/
+/* Standard modifications to add chunks.  These do not require the _SUPPORTED
+ * macros because the chunks can be there regardless of whether this specific
+ * libpng supports them.
+ */
+typedef struct gama_modification
+{
+   png_modification this;
+   png_fixed_point  gamma;
+} gama_modification;
+static int
+gama_modify(png_modifier *pm, png_modification *me, int add)
+{
+   UNUSED(add)
+   /* This simply dumps the given gamma value into the buffer. */
+   png_save_uint_32(pm->buffer, 4);
+   png_save_uint_32(pm->buffer+4, CHUNK_gAMA);
+   png_save_uint_32(pm->buffer+8, ((gama_modification*)me)->gamma);
+   return 1;
+}
+static void
+gama_modification_init(gama_modification *me, png_modifier *pm, double gammad)
+{
+   double g;
+   modification_init(&me->this);
+   me->this.chunk = CHUNK_gAMA;
+   me->this.modify_fn = gama_modify;
+   me->this.add = CHUNK_PLTE;
+   g = fix(gammad);
+   me->gamma = (png_fixed_point)g;
+   me->this.next = pm->modifications;
+   pm->modifications = &me->this;
+}
+typedef struct chrm_modification
+{
+   png_modification          this;
+   PNG_CONST color_encoding *encoding;
+   png_fixed_point           wx, wy, rx, ry, gx, gy, bx, by;
+} chrm_modification;
+static int
+chrm_modify(png_modifier *pm, png_modification *me, int add)
+{
+   UNUSED(add)
+   /* As with gAMA this just adds the required cHRM chunk to the buffer. */
+   png_save_uint_32(pm->buffer   , 32);
+   png_save_uint_32(pm->buffer+ 4, CHUNK_cHRM);
+   png_save_uint_32(pm->buffer+ 8, ((chrm_modification*)me)->wx);
+   png_save_uint_32(pm->buffer+12, ((chrm_modification*)me)->wy);
+   png_save_uint_32(pm->buffer+16, ((chrm_modification*)me)->rx);
+   png_save_uint_32(pm->buffer+20, ((chrm_modification*)me)->ry);
+   png_save_uint_32(pm->buffer+24, ((chrm_modification*)me)->gx);
+   png_save_uint_32(pm->buffer+28, ((chrm_modification*)me)->gy);
+   png_save_uint_32(pm->buffer+32, ((chrm_modification*)me)->bx);
+   png_save_uint_32(pm->buffer+36, ((chrm_modification*)me)->by);
+   return 1;
+}
+static void
+chrm_modification_init(chrm_modification *me, png_modifier *pm,
+   PNG_CONST color_encoding *encoding)
+{
+   CIE_color white = white_point(encoding);
+   /* Original end points: */
+   me->encoding = encoding;
+   /* Chromaticities (in fixed point): */
+   me->wx = fix(chromaticity_x(white));
+   me->wy = fix(chromaticity_y(white));
+   me->rx = fix(chromaticity_x(encoding->red));
+   me->ry = fix(chromaticity_y(encoding->red));
+   me->gx = fix(chromaticity_x(encoding->green));
+   me->gy = fix(chromaticity_y(encoding->green));
+   me->bx = fix(chromaticity_x(encoding->blue));
+   me->by = fix(chromaticity_y(encoding->blue));
+   modification_init(&me->this);
+   me->this.chunk = CHUNK_cHRM;
+   me->this.modify_fn = chrm_modify;
+   me->this.add = CHUNK_PLTE;
+   me->this.next = pm->modifications;
+   pm->modifications = &me->this;
+}
+typedef struct srgb_modification
+{
+   png_modification this;
+   png_byte         intent;
+} srgb_modification;
+static int
+srgb_modify(png_modifier *pm, png_modification *me, int add)
+{
+   UNUSED(add)
+   /* As above, ignore add and just make a new chunk */
+   png_save_uint_32(pm->buffer, 1);
+   png_save_uint_32(pm->buffer+4, CHUNK_sRGB);
+   pm->buffer[8] = ((srgb_modification*)me)->intent;
+   return 1;
+}
+static void
+srgb_modification_init(srgb_modification *me, png_modifier *pm, png_byte intent)
+{
+   modification_init(&me->this);
+   me->this.chunk = CHUNK_sBIT;
+   if (intent <= 3) /* if valid, else *delete* sRGB chunks */
+   {
+      me->this.modify_fn = srgb_modify;
+      me->this.add = CHUNK_PLTE;
+      me->intent = intent;
+   }
+   else
+   {
+      me->this.modify_fn = 0;
+      me->this.add = 0;
+      me->intent = 0;
+   }
+   me->this.next = pm->modifications;
+   pm->modifications = &me->this;
+}
+typedef struct sbit_modification
+{
+   png_modification this;
+   png_byte         sbit;
+} sbit_modification;
+static int
+sbit_modify(png_modifier *pm, png_modification *me, int add)
+{
+   png_byte sbit = ((sbit_modification*)me)->sbit;
+   if (pm->bit_depth > sbit)
+   {
+      int cb = 0;
+      switch (pm->colour_type)
+      {
+         case 0:
+            cb = 1;
+            break;
+         case 2:
+         case 3:
+            cb = 3;
+            break;
+         case 4:
+            cb = 2;
+            break;
+         case 6:
+            cb = 4;
+            break;
+         default:
+            png_error(pm->this.pread,
+               "unexpected colour type in sBIT modification");
+      }
+      png_save_uint_32(pm->buffer, cb);
+      png_save_uint_32(pm->buffer+4, CHUNK_sBIT);
+      while (cb > 0)
+         (pm->buffer+8)[--cb] = sbit;
+      return 1;
+   }
+   else if (!add)
+   {
+      /* Remove the sBIT chunk */
+      pm->buffer_count = pm->buffer_position = 0;
+      return 1;
+   }
+   else
+      return 0; /* do nothing */
+}
+static void
+sbit_modification_init(sbit_modification *me, png_modifier *pm, png_byte sbit)
+{
+   modification_init(&me->this);
+   me->this.chunk = CHUNK_sBIT;
+   me->this.modify_fn = sbit_modify;
+   me->this.add = CHUNK_PLTE;
+   me->sbit = sbit;
+   me->this.next = pm->modifications;
+   pm->modifications = &me->this;
+}
+#endif /* PNG_READ_TRANSFORMS_SUPPORTED */
+/***************************** STANDARD PNG FILES *****************************/
+/* Standard files - write and save standard files. */
+/* There are two basic forms of standard images.  Those which attempt to have
+ * all the possible pixel values (not possible for 16bpp images, but a range of
+ * values are produced) and those which have a range of image sizes.  The former
+ * are used for testing transforms, in particular gamma correction and bit
+ * reduction and increase.  The latter are reserved for testing the behavior of
+ * libpng with respect to 'odd' image sizes - particularly small images where
+ * rows become 1 byte and interlace passes disappear.
+ *
+ * The first, most useful, set are the 'transform' images, the second set of
+ * small images are the 'size' images.
+ *
+ * The transform files are constructed with rows which fit into a 1024 byte row
+ * buffer.  This makes allocation easier below.  Further regardless of the file
+ * format every row has 128 pixels (giving 1024 bytes for 64bpp formats).
+ *
+ * Files are stored with no gAMA or sBIT chunks, with a PLTE only when needed
+ * and with an ID derived from the colour type, bit depth and interlace type
+ * as above (FILEID).  The width (128) and height (variable) are not stored in
+ * the FILEID - instead the fields are set to 0, indicating a transform file.
+ *
+ * The size files ar constructed with rows a maximum of 128 bytes wide, allowing
+ * a maximum width of 16 pixels (for the 64bpp case.)  They also have a maximum
+ * height of 16 rows.  The width and height are stored in the FILEID and, being
+ * non-zero, indicate a size file.
+ *
+ * For palette image (colour type 3) multiple transform images are stored with
+ * the same bit depth to allow testing of more colour combinations -
+ * particularly important for testing the gamma code because libpng uses a
+ * different code path for palette images.  For size images a single palette is
+ * used.
+ */
+/* Make a 'standard' palette.  Because there are only 256 entries in a palette
+ * (maximum) this actually makes a random palette in the hope that enough tests
+ * will catch enough errors.  (Note that the same palette isn't produced every
+ * time for the same test - it depends on what previous tests have been run -
+ * but a given set of arguments to pngvalid will always produce the same palette
+ * at the same test!  This is why pseudo-random number generators are useful for
+ * testing.)
+ *
+ * The store must be open for write when this is called, otherwise an internal
+ * error will occur.  This routine contains its own magic number seed, so the
+ * palettes generated don't change if there are intervening errors (changing the
+ * calls to the store_mark seed.)
+ */
+static store_palette_entry *
+make_standard_palette(png_store* ps, int npalette, int do_tRNS)
+{
+   static png_uint_32 palette_seed[2] = { 0x87654321, 9 };
+   int i = 0;
+   png_byte values[256][4];
+   /* Always put in black and white plus the six primary and secondary colors.
+    */
+   for (; i<8; ++i)
+   {
+      values[i][1] = (i&1) ? 255 : 0;
+      values[i][2] = (i&2) ? 255 : 0;
+      values[i][3] = (i&4) ? 255 : 0;
+   }
+   /* Then add 62 grays (one quarter of the remaining 256 slots). */
+   {
+      int j = 0;
+      png_byte random_bytes[4];
+      png_byte need[256];
+      need[0] = 0; /*got black*/
+      memset(need+1, 1, (sizeof need)-2); /*need these*/
+      need[255] = 0; /*but not white*/
+      while (i<70)
+      {
+         png_byte b;
+         if (j==0)
+         {
+            make_four_random_bytes(palette_seed, random_bytes);
+            j = 4;
+         }
+         b = random_bytes[--j];
+         if (need[b])
+         {
+            values[i][1] = b;
+            values[i][2] = b;
+            values[i++][3] = b;
+         }
+      }
+   }
+   /* Finally add 192 colors at random - don't worry about matches to things we
+    * already have, chance is less than 1/65536.  Don't worry about grays,
+    * chance is the same, so we get a duplicate or extra gray less than 1 time
+    * in 170.
+    */
+   for (; i<256; ++i)
+      make_four_random_bytes(palette_seed, values[i]);
+   /* Fill in the alpha values in the first byte.  Just use all possible values
+    * (0..255) in an apparently random order:
+    */
+   {
+      store_palette_entry *palette;
+      png_byte selector[4];
+      make_four_random_bytes(palette_seed, selector);
+      if (do_tRNS)
+         for (i=0; i<256; ++i)
+            values[i][0] = (png_byte)(i ^ selector[0]);
+      else
+         for (i=0; i<256; ++i)
+            values[i][0] = 255; /* no transparency/tRNS chunk */
+      /* 'values' contains 256 ARGB values, but we only need 'npalette'.
+       * 'npalette' will always be a power of 2: 2, 4, 16 or 256.  In the low
+       * bit depth cases select colors at random, else it is difficult to have
+       * a set of low bit depth palette test with any chance of a reasonable
+       * range of colors.  Do this by randomly permuting values into the low
+       * 'npalette' entries using an XOR mask generated here.  This also
+       * permutes the npalette == 256 case in a potentially useful way (there is
+       * no relationship between palette index and the color value therein!)
+       */
+      palette = store_write_palette(ps, npalette);
+      for (i=0; i<npalette; ++i)
+      {
+         palette[i].alpha = values[i ^ selector[1]][0];
+         palette[i].red   = values[i ^ selector[1]][1];
+         palette[i].green = values[i ^ selector[1]][2];
+         palette[i].blue  = values[i ^ selector[1]][3];
+      }
+      return palette;
+   }
+}
+/* Initialize a standard palette on a write stream.  The 'do_tRNS' argument
+ * indicates whether or not to also set the tRNS chunk.
+ */
+static void
+init_standard_palette(png_store *ps, png_structp pp, png_infop pi, int npalette,
+   int do_tRNS)
+{
+   store_palette_entry *ppal = make_standard_palette(ps, npalette, do_tRNS);
+   {
+      int i;
+      png_color palette[256];
+      /* Set all entries to detect overread errors. */
+      for (i=0; i<npalette; ++i)
+      {
+         palette[i].red = ppal[i].red;
+         palette[i].green = ppal[i].green;
+         palette[i].blue = ppal[i].blue;
+      }
+      /* Just in case fill in the rest with detectable values: */
+      for (; i<256; ++i)
+         palette[i].red = palette[i].green = palette[i].blue = 42;
+      png_set_PLTE(pp, pi, palette, npalette);
+   }
+   if (do_tRNS)
+   {
+      int i, j;
+      png_byte tRNS[256];
+      /* Set all the entries, but skip trailing opaque entries */
+      for (i=j=0; i<npalette; ++i)
+         if ((tRNS[i] = ppal[i].alpha) < 255)
+            j = i+1;
+      /* Fill in the remainder with a detectable value: */
+      for (; i<256; ++i)
+         tRNS[i] = 24;
+      if (j > 0)
+         png_set_tRNS(pp, pi, tRNS, j, 0/*color*/);
+   }
+}
+/* The number of passes is related to the interlace type. There was no libpng
+ * API to determine this prior to 1.5, so we need an inquiry function:
+ */
+static int
+npasses_from_interlace_type(png_structp pp, int interlace_type)
+{
+   switch (interlace_type)
+   {
+   default:
+      png_error(pp, "invalid interlace type");
+   case PNG_INTERLACE_NONE:
+      return 1;
+   case PNG_INTERLACE_ADAM7:
+      return PNG_INTERLACE_ADAM7_PASSES;
+   }
+}
+static unsigned int
+bit_size(png_structp pp, png_byte colour_type, png_byte bit_depth)
+{
+   switch (colour_type)
+   {
+      default: png_error(pp, "invalid color type");
+      case 0:  return bit_depth;
+      case 2:  return 3*bit_depth;
+      case 3:  return bit_depth;
+      case 4:  return 2*bit_depth;
+      case 6:  return 4*bit_depth;
+   }
+}
+#define TRANSFORM_WIDTH  128U
+#define TRANSFORM_ROWMAX (TRANSFORM_WIDTH*8U)
+#define SIZE_ROWMAX (16*8U) /* 16 pixels, max 8 bytes each - 128 bytes */
+#define STANDARD_ROWMAX TRANSFORM_ROWMAX /* The larger of the two */
+#define SIZE_HEIGHTMAX 16 /* Maximum range of size images */
+static size_t
+transform_rowsize(png_structp pp, png_byte colour_type, png_byte bit_depth)
+{
+   return (TRANSFORM_WIDTH * bit_size(pp, colour_type, bit_depth)) / 8;
+}
+/* transform_width(pp, colour_type, bit_depth) current returns the same number
+ * every time, so just use a macro:
+ */
+#define transform_width(pp, colour_type, bit_depth) TRANSFORM_WIDTH
+static png_uint_32
+transform_height(png_structp pp, png_byte colour_type, png_byte bit_depth)
+{
+   switch (bit_size(pp, colour_type, bit_depth))
+   {
+      case 1:
+      case 2:
+      case 4:
+         return 1;   /* Total of 128 pixels */
+      case 8:
+         return 2;   /* Total of 256 pixels/bytes */
+      case 16:
+         return 512; /* Total of 65536 pixels */
+      case 24:
+      case 32:
+         return 512; /* 65536 pixels */
+      case 48:
+      case 64:
+         return 2048;/* 4 x 65536 pixels. */
+#        define TRANSFORM_HEIGHTMAX 2048
+      default:
+         return 0;   /* Error, will be caught later */
+   }
+}
+/* The following can only be defined here, now we have the definitions
+ * of the transform image sizes.
+ */
+static png_uint_32
+standard_width(png_structp pp, png_uint_32 id)
+{
+   png_uint_32 width = WIDTH_FROM_ID(id);
+   UNUSED(pp)
+   if (width == 0)
+      width = transform_width(pp, COL_FROM_ID(id), DEPTH_FROM_ID(id));
+   return width;
+}
+static png_uint_32
+standard_height(png_structp pp, png_uint_32 id)
+{
+   png_uint_32 height = HEIGHT_FROM_ID(id);
+   if (height == 0)
+      height = transform_height(pp, COL_FROM_ID(id), DEPTH_FROM_ID(id));
+   return height;
+}
+static png_uint_32
+standard_rowsize(png_structp pp, png_uint_32 id)
+{
+   png_uint_32 width = standard_width(pp, id);
+   /* This won't overflow: */
+   width *= bit_size(pp, COL_FROM_ID(id), DEPTH_FROM_ID(id));
+   return (width + 7) / 8;
+}
+static void
+transform_row(png_structp pp, png_byte buffer[TRANSFORM_ROWMAX],
+   png_byte colour_type, png_byte bit_depth, png_uint_32 y)
+{
+   png_uint_32 v = y << 7;
+   png_uint_32 i = 0;
+   switch (bit_size(pp, colour_type, bit_depth))
+   {
+      case 1:
+         while (i<128/8) buffer[i] = v & 0xff, v += 17, ++i;
+         return;
+      case 2:
+         while (i<128/4) buffer[i] = v & 0xff, v += 33, ++i;
+         return;
+      case 4:
+         while (i<128/2) buffer[i] = v & 0xff, v += 65, ++i;
+         return;
+      case 8:
+         /* 256 bytes total, 128 bytes in each row set as follows: */
+         while (i<128) buffer[i] = v & 0xff, ++v, ++i;
+         return;
+      case 16:
+         /* Generate all 65536 pixel values in order, which includes the 8 bit
+          * GA case as well as the 16 bit G case.
+          */
+         while (i<128)
+            buffer[2*i] = (v>>8) & 0xff, buffer[2*i+1] = v & 0xff, ++v, ++i;
+         return;
+      case 24:
+         /* 65535 pixels, but rotate the values. */
+         while (i<128)
+         {
+            /* Three bytes per pixel, r, g, b, make b by r^g */
+            buffer[3*i+0] = (v >> 8) & 0xff;
+            buffer[3*i+1] = v & 0xff;
+            buffer[3*i+2] = ((v >> 8) ^ v) & 0xff;
+            ++v;
+            ++i;
+         }
+         return;
+      case 32:
+         /* 65535 pixels, r, g, b, a; just replicate */
+         while (i<128)
+         {
+            buffer[4*i+0] = (v >> 8) & 0xff;
+            buffer[4*i+1] = v & 0xff;
+            buffer[4*i+2] = (v >> 8) & 0xff;
+            buffer[4*i+3] = v & 0xff;
+            ++v;
+            ++i;
+         }
+         return;
+      case 48:
+         /* y is maximum 2047, giving 4x65536 pixels, make 'r' increase by 1 at
+          * each pixel, g increase by 257 (0x101) and 'b' by 0x1111:
+          */
+         while (i<128)
+         {
+            png_uint_32 t = v++;
+            buffer[6*i+0] = (t >> 8) & 0xff;
+            buffer[6*i+1] = t & 0xff;
+            t *= 257;
+            buffer[6*i+2] = (t >> 8) & 0xff;
+            buffer[6*i+3] = t & 0xff;
+            t *= 17;
+            buffer[6*i+4] = (t >> 8) & 0xff;
+            buffer[6*i+5] = t & 0xff;
+            ++i;
+         }
+         return;
+      case 64:
+         /* As above in the 32 bit case. */
+         while (i<128)
+         {
+            png_uint_32 t = v++;
+            buffer[8*i+0] = (t >> 8) & 0xff;
+            buffer[8*i+1] = t & 0xff;
+            buffer[8*i+4] = (t >> 8) & 0xff;
+            buffer[8*i+5] = t & 0xff;
+            t *= 257;
+            buffer[8*i+2] = (t >> 8) & 0xff;
+            buffer[8*i+3] = t & 0xff;
+            buffer[8*i+6] = (t >> 8) & 0xff;
+            buffer[8*i+7] = t & 0xff;
+            ++i;
+         }
+         return;
+      default:
+         break;
+   }
+   png_error(pp, "internal error");
+}
+/* This is just to do the right cast - could be changed to a function to check
+ * 'bd' but there isn't much point.
+ */
+#define DEPTH(bd) ((png_byte)(1U << (bd)))
+/* Make a standardized image given a an image colour type, bit depth and
+ * interlace type.  The standard images have a very restricted range of
+ * rows and heights and are used for testing transforms rather than image
+ * layout details.  See make_size_images below for a way to make images
+ * that test odd sizes along with the libpng interlace handling.
+ */
+static void
+make_transform_image(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type,
+    png_byte PNG_CONST bit_depth, int palette_number, int interlace_type,
+    png_const_charp name)
+{
+   context(ps, fault);
+   Try
+   {
+      png_infop pi;
+      png_structp pp = set_store_for_write(ps, &pi, name);
+      png_uint_32 h;
+      /* In the event of a problem return control to the Catch statement below
+       * to do the clean up - it is not possible to 'return' directly from a Try
+       * block.
+       */
+      if (pp == NULL)
+         Throw ps;
+      h = transform_height(pp, colour_type, bit_depth);
+      png_set_IHDR(pp, pi, transform_width(pp, colour_type, bit_depth), h,
+         bit_depth, colour_type, interlace_type,
+         PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
+#ifdef PNG_TEXT_SUPPORTED
+      {
+         static char key[] = "image name"; /* must be writeable */
+         size_t pos;
+         png_text text;
+         char copy[FILE_NAME_SIZE];
+         /* Use a compressed text string to test the correct interaction of text
+          * compression and IDAT compression.
+          */
+         text.compression = PNG_TEXT_COMPRESSION_zTXt;
+         text.key = key;
+         /* Yuck: the text must be writable! */
+         pos = safecat(copy, sizeof copy, 0, ps->wname);
+         text.text = copy;
+         text.text_length = pos;
+         text.itxt_length = 0;
+         text.lang = 0;
+         text.lang_key = 0;
+         png_set_text(pp, pi, &text, 1);
+      }
+#endif
+      if (colour_type == 3) /* palette */
+         init_standard_palette(ps, pp, pi, 1U << bit_depth, 1/*do tRNS*/);
+      png_write_info(pp, pi);
+      if (png_get_rowbytes(pp, pi) !=
+          transform_rowsize(pp, colour_type, bit_depth))
+         png_error(pp, "row size incorrect");
+      else
+      {
+         /* Somewhat confusingly this must be called *after* png_write_info
+          * because if it is called before, the information in *pp has not been
+          * updated to reflect the interlaced image.
+          */
+         int npasses = png_set_interlace_handling(pp);
+         int pass;
+         if (npasses != npasses_from_interlace_type(pp, interlace_type))
+            png_error(pp, "write: png_set_interlace_handling failed");
+         for (pass=0; pass<npasses; ++pass)
+         {
+            png_uint_32 y;
+            for (y=0; y<h; ++y)
+            {
+               png_byte buffer[TRANSFORM_ROWMAX];
+               transform_row(pp, buffer, colour_type, bit_depth, y);
+               png_write_row(pp, buffer);
+            }
+         }
+      }
+#ifdef PNG_TEXT_SUPPORTED
+      {
+         static char key[] = "end marker";
+         static char comment[] = "end";
+         png_text text;
+         /* Use a compressed text string to test the correct interaction of text
+          * compression and IDAT compression.
+          */
+         text.compression = PNG_TEXT_COMPRESSION_zTXt;
+         text.key = key;
+         text.text = comment;
+         text.text_length = (sizeof comment)-1;
+         text.itxt_length = 0;
+         text.lang = 0;
+         text.lang_key = 0;
+         png_set_text(pp, pi, &text, 1);
+      }
+#endif
+      png_write_end(pp, pi);
+      /* And store this under the appropriate id, then clean up. */
+      store_storefile(ps, FILEID(colour_type, bit_depth, palette_number,
+         interlace_type, 0, 0, 0));
+      store_write_reset(ps);
+   }
+   Catch(fault)
+   {
+      /* Use the png_store returned by the exception. This may help the compiler
+       * because 'ps' is not used in this branch of the setjmp.  Note that fault
+       * and ps will always be the same value.
+       */
+      store_write_reset(fault);
+   }
+}
+static void
+make_transform_images(png_store *ps)
+{
+   png_byte colour_type = 0;
+   png_byte bit_depth = 0;
+   int palette_number = 0;
+   /* This is in case of errors. */
+   safecat(ps->test, sizeof ps->test, 0, "make standard images");
+   /* Use next_format to enumerate all the combinations we test, including
+    * generating multiple low bit depth palette images.
+    */
+   while (next_format(&colour_type, &bit_depth, &palette_number))
+   {
+      int interlace_type;
+      for (interlace_type = PNG_INTERLACE_NONE;
+           interlace_type < PNG_INTERLACE_LAST; ++interlace_type)
+      {
+         char name[FILE_NAME_SIZE];
+         standard_name(name, sizeof name, 0, colour_type, bit_depth,
+            palette_number, interlace_type, 0, 0, 0);
+         make_transform_image(ps, colour_type, bit_depth, palette_number,
+            interlace_type, name);
+      }
+   }
+}
+/* The following two routines use the PNG interlace support macros from
+ * png.h to interlace or deinterlace rows.
+ */
+static void
+interlace_row(png_bytep buffer, png_const_bytep imageRow,
+   unsigned int pixel_size, png_uint_32 w, int pass)
+{
+   png_uint_32 xin, xout, xstep;
+   /* Note that this can, trivially, be optimized to a memcpy on pass 7, the
+    * code is presented this way to make it easier to understand.  In practice
+    * consult the code in the libpng source to see other ways of doing this.
+    */
+   xin = PNG_PASS_START_COL(pass);
+   xstep = 1U<<PNG_PASS_COL_SHIFT(pass);
+   for (xout=0; xin<w; xin+=xstep)
+   {
+      pixel_copy(buffer, xout, imageRow, xin, pixel_size);
+      ++xout;
+   }
+}
+static void
+deinterlace_row(png_bytep buffer, png_const_bytep row,
+   unsigned int pixel_size, png_uint_32 w, int pass)
+{
+   /* The inverse of the above, 'row' is part of row 'y' of the output image,
+    * in 'buffer'.  The image is 'w' wide and this is pass 'pass', distribute
+    * the pixels of row into buffer and return the number written (to allow
+    * this to be checked).
+    */
+   png_uint_32 xin, xout, xstep;
+   xout = PNG_PASS_START_COL(pass);
+   xstep = 1U<<PNG_PASS_COL_SHIFT(pass);
+   for (xin=0; xout<w; xout+=xstep)
+   {
+      pixel_copy(buffer, xout, row, xin, pixel_size);
+      ++xin;
+   }
+}
+/* Build a single row for the 'size' test images; this fills in only the
+ * first bit_width bits of the sample row.
+ */
+static void
+size_row(png_byte buffer[SIZE_ROWMAX], png_uint_32 bit_width, png_uint_32 y)
+{
+   /* height is in the range 1 to 16, so: */
+   y = ((y & 1) << 7) + ((y & 2) << 6) + ((y & 4) << 5) + ((y & 8) << 4);
+   /* the following ensures bits are set in small images: */
+   y ^= 0xA5;
+   while (bit_width >= 8)
+      *buffer++ = (png_byte)y++, bit_width -= 8;
+   /* There may be up to 7 remaining bits, these go in the most significant
+    * bits of the byte.
+    */
+   if (bit_width > 0)
+   {
+      png_uint_32 mask = (1U<<(8-bit_width))-1;
+      *buffer = (png_byte)((*buffer & mask) | (y & ~mask));
+   }
+}
+static void
+make_size_image(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type,
+    png_byte PNG_CONST bit_depth, int PNG_CONST interlace_type,
+    png_uint_32 PNG_CONST w, png_uint_32 PNG_CONST h,
+    int PNG_CONST do_interlace)
+{
+   context(ps, fault);
+   Try
+   {
+      png_infop pi;
+      png_structp pp;
+      unsigned int pixel_size;
+      /* Make a name and get an appropriate id for the store: */
+      char name[FILE_NAME_SIZE];
+      PNG_CONST png_uint_32 id = FILEID(colour_type, bit_depth, 0/*palette*/,
+         interlace_type, w, h, do_interlace);
+      standard_name_from_id(name, sizeof name, 0, id);
+      pp = set_store_for_write(ps, &pi, name);
+      /* In the event of a problem return control to the Catch statement below
+       * to do the clean up - it is not possible to 'return' directly from a Try
+       * block.
+       */
+      if (pp == NULL)
+         Throw ps;
+      png_set_IHDR(pp, pi, w, h, bit_depth, colour_type, interlace_type,
+         PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
+      if (colour_type == 3) /* palette */
+         init_standard_palette(ps, pp, pi, 1U << bit_depth, 0/*do tRNS*/);
+      png_write_info(pp, pi);
+      /* Calculate the bit size, divide by 8 to get the byte size - this won't
+       * overflow because we know the w values are all small enough even for
+       * a system where 'unsigned int' is only 16 bits.
+       */
+      pixel_size = bit_size(pp, colour_type, bit_depth);
+      if (png_get_rowbytes(pp, pi) != ((w * pixel_size) + 7) / 8)
+         png_error(pp, "row size incorrect");
+      else
+      {
+         int npasses = npasses_from_interlace_type(pp, interlace_type);
+         png_uint_32 y;
+         int pass;
+         png_byte image[16][SIZE_ROWMAX];
+         /* To help consistent error detection make the parts of this buffer
+          * that aren't set below all '1':
+          */
+         memset(image, 0xff, sizeof image);
+         if (!do_interlace && npasses != png_set_interlace_handling(pp))
+            png_error(pp, "write: png_set_interlace_handling failed");
+         /* Prepare the whole image first to avoid making it 7 times: */
+         for (y=0; y<h; ++y)
+            size_row(image[y], w * pixel_size, y);
+         for (pass=0; pass<npasses; ++pass)
+         {
+            /* The following two are for checking the macros: */
+            PNG_CONST png_uint_32 wPass = PNG_PASS_COLS(w, pass);
+            /* If do_interlace is set we don't call png_write_row for every
+             * row because some of them are empty.  In fact, for a 1x1 image,
+             * most of them are empty!
+             */
+            for (y=0; y<h; ++y)
+            {
+               png_const_bytep row = image[y];
+               png_byte tempRow[SIZE_ROWMAX];
+               /* If do_interlace *and* the image is interlaced we
+                * need a reduced interlace row; this may be reduced
+                * to empty.
+                */
+               if (do_interlace && interlace_type == PNG_INTERLACE_ADAM7)
+               {
+                  /* The row must not be written if it doesn't exist, notice
+                   * that there are two conditions here, either the row isn't
+                   * ever in the pass or the row would be but isn't wide
+                   * enough to contribute any pixels.  In fact the wPass test
+                   * can be used to skip the whole y loop in this case.
+                   */
+                  if (PNG_ROW_IN_INTERLACE_PASS(y, pass) && wPass > 0)
+                  {
+                     /* Set to all 1's for error detection (libpng tends to
+                      * set unset things to 0).
+                      */
+                     memset(tempRow, 0xff, sizeof tempRow);
+                     interlace_row(tempRow, row, pixel_size, w, pass);
+                     row = tempRow;
+                  }
+                  else
+                     continue;
+               }
+               /* Only get to here if the row has some pixels in it. */
+               png_write_row(pp, row);
+            }
+         }
+      }
+      png_write_end(pp, pi);
+      /* And store this under the appropriate id, then clean up. */
+      store_storefile(ps, id);
+      store_write_reset(ps);
+   }
+   Catch(fault)
+   {
+      /* Use the png_store returned by the exception. This may help the compiler
+       * because 'ps' is not used in this branch of the setjmp.  Note that fault
+       * and ps will always be the same value.
+       */
+      store_write_reset(fault);
+   }
+}
+static void
+make_size(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type, int bdlo,
+    int PNG_CONST bdhi)
+{
+   for (; bdlo <= bdhi; ++bdlo)
+   {
+      png_uint_32 width;
+      for (width = 1; width <= 16; ++width)
+      {
+         png_uint_32 height;
+         for (height = 1; height <= 16; ++height)
+         {
+            /* The four combinations of DIY interlace and interlace or not -
+             * no interlace + DIY should be identical to no interlace with
+             * libpng doing it.
+             */
+            make_size_image(ps, colour_type, DEPTH(bdlo), PNG_INTERLACE_NONE,
+               width, height, 0);
+            make_size_image(ps, colour_type, DEPTH(bdlo), PNG_INTERLACE_NONE,
+               width, height, 1);
+            make_size_image(ps, colour_type, DEPTH(bdlo), PNG_INTERLACE_ADAM7,
+               width, height, 0);
+            make_size_image(ps, colour_type, DEPTH(bdlo), PNG_INTERLACE_ADAM7,
+               width, height, 1);
+         }
+      }
+   }
+}
+static void
+make_size_images(png_store *ps)
+{
+   /* This is in case of errors. */
+   safecat(ps->test, sizeof ps->test, 0, "make size images");
+   /* Arguments are colour_type, low bit depth, high bit depth
+    */
+   make_size(ps, 0, 0, WRITE_BDHI);
+   make_size(ps, 2, 3, WRITE_BDHI);
+   make_size(ps, 3, 0, 3 /*palette: max 8 bits*/);
+   make_size(ps, 4, 3, WRITE_BDHI);
+   make_size(ps, 6, 3, WRITE_BDHI);
+}
+/* Return a row based on image id and 'y' for checking: */
+static void
+standard_row(png_structp pp, png_byte std[STANDARD_ROWMAX], png_uint_32 id,
+   png_uint_32 y)
+{
+   if (WIDTH_FROM_ID(id) == 0)
+      transform_row(pp, std, COL_FROM_ID(id), DEPTH_FROM_ID(id), y);
+   else
+      size_row(std, WIDTH_FROM_ID(id) * bit_size(pp, COL_FROM_ID(id),
+         DEPTH_FROM_ID(id)), y);
+}
+/* Tests - individual test cases */
+/* Like 'make_standard' but errors are deliberately introduced into the calls
+ * to ensure that they get detected - it should not be possible to write an
+ * invalid image with libpng!
+ */
+#ifdef PNG_WARNINGS_SUPPORTED
+static void
+sBIT0_error_fn(png_structp pp, png_infop pi)
+{
+   /* 0 is invalid... */
+   png_color_8 bad;
+   bad.red = bad.green = bad.blue = bad.gray = bad.alpha = 0;
+   png_set_sBIT(pp, pi, &bad);
+}
+static void
+sBIT_error_fn(png_structp pp, png_infop pi)
+{
+   png_byte bit_depth;
+   png_color_8 bad;
+   if (png_get_color_type(pp, pi) == PNG_COLOR_TYPE_PALETTE)
+      bit_depth = 8;
+   else
+      bit_depth = png_get_bit_depth(pp, pi);
+   /* Now we know the bit depth we can easily generate an invalid sBIT entry */
+   bad.red = bad.green = bad.blue = bad.gray = bad.alpha =
+      (png_byte)(bit_depth+1);
+   png_set_sBIT(pp, pi, &bad);
+}
+static PNG_CONST struct
+{
+   void          (*fn)(png_structp, png_infop);
+   PNG_CONST char *msg;
+   unsigned int    warning :1; /* the error is a warning... */
+} error_test[] =
+    {
+       /* no warnings makes these errors undetectable. */
+       { sBIT0_error_fn, "sBIT(0): failed to detect error", 1 },
+       { sBIT_error_fn, "sBIT(too big): failed to detect error", 1 },
+    };
+static void
+make_error(png_store* volatile psIn, png_byte PNG_CONST colour_type,
+    png_byte bit_depth, int interlace_type, int test, png_const_charp name)
+{
+   png_store * volatile ps = psIn;
+   context(ps, fault);
+   Try
+   {
+      png_structp pp;
+      png_infop pi;
+      pp = set_store_for_write(ps, &pi, name);
+      if (pp == NULL)
+         Throw ps;
+      png_set_IHDR(pp, pi, transform_width(pp, colour_type, bit_depth),
+         transform_height(pp, colour_type, bit_depth), bit_depth, colour_type,
+         interlace_type, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
+      if (colour_type == 3) /* palette */
+         init_standard_palette(ps, pp, pi, 1U << bit_depth, 0/*do tRNS*/);
+      /* Time for a few errors; these are in various optional chunks, the
+       * standard tests test the standard chunks pretty well.
+       */
+#     define exception__prev exception_prev_1
+#     define exception__env exception_env_1
+      Try
+      {
+         /* Expect this to throw: */
+         ps->expect_error = !error_test[test].warning;
+         ps->expect_warning = error_test[test].warning;
+         ps->saw_warning = 0;
+         error_test[test].fn(pp, pi);
+         /* Normally the error is only detected here: */
+         png_write_info(pp, pi);
+         /* And handle the case where it was only a warning: */
+         if (ps->expect_warning && ps->saw_warning)
+            Throw ps;
+         /* If we get here there is a problem, we have success - no error or
+          * no warning - when we shouldn't have success.  Log an error.
+          */
+         store_log(ps, pp, error_test[test].msg, 1 /*error*/);
+      }
+      Catch (fault)
+         ps = fault; /* expected exit, make sure ps is not clobbered */
+#undef exception__prev
+#undef exception__env
+      /* And clear these flags */
+      ps->expect_error = 0;
+      ps->expect_warning = 0;
+      /* Now write the whole image, just to make sure that the detected, or
+       * undetected, errro has not created problems inside libpng.
+       */
+      if (png_get_rowbytes(pp, pi) !=
+          transform_rowsize(pp, colour_type, bit_depth))
+         png_error(pp, "row size incorrect");
+      else
+      {
+         png_uint_32 h = transform_height(pp, colour_type, bit_depth);
+         int npasses = png_set_interlace_handling(pp);
+         int pass;
+         if (npasses != npasses_from_interlace_type(pp, interlace_type))
+            png_error(pp, "write: png_set_interlace_handling failed");
+         for (pass=0; pass<npasses; ++pass)
+         {
+            png_uint_32 y;
+            for (y=0; y<h; ++y)
+            {
+               png_byte buffer[TRANSFORM_ROWMAX];
+               transform_row(pp, buffer, colour_type, bit_depth, y);
+               png_write_row(pp, buffer);
+            }
+         }
+      }
+      png_write_end(pp, pi);
+      /* The following deletes the file that was just written. */
+      store_write_reset(ps);
+   }
+   Catch(fault)
+   {
+      store_write_reset(fault);
+   }
+}
+static int
+make_errors(png_modifier* PNG_CONST pm, png_byte PNG_CONST colour_type,
+    int bdlo, int PNG_CONST bdhi)
+{
+   for (; bdlo <= bdhi; ++bdlo)
+   {
+      int interlace_type;
+      for (interlace_type = PNG_INTERLACE_NONE;
+           interlace_type < PNG_INTERLACE_LAST; ++interlace_type)
+      {
+         unsigned int test;
+         char name[FILE_NAME_SIZE];
+         standard_name(name, sizeof name, 0, colour_type, 1<<bdlo, 0,
+            interlace_type, 0, 0, 0);
+         for (test=0; test<(sizeof error_test)/(sizeof error_test[0]); ++test)
+         {
+            make_error(&pm->this, colour_type, DEPTH(bdlo), interlace_type,
+               test, name);
+            if (fail(pm))
+               return 0;
+         }
+      }
+   }
+   return 1; /* keep going */
+}
+#endif
+static void
+perform_error_test(png_modifier *pm)
+{
+#ifdef PNG_WARNINGS_SUPPORTED /* else there are no cases that work! */
+   /* Need to do this here because we just write in this test. */
+   safecat(pm->this.test, sizeof pm->this.test, 0, "error test");
+   if (!make_errors(pm, 0, 0, WRITE_BDHI))
+      return;
+   if (!make_errors(pm, 2, 3, WRITE_BDHI))
+      return;
+   if (!make_errors(pm, 3, 0, 3))
+      return;
+   if (!make_errors(pm, 4, 3, WRITE_BDHI))
+      return;
+   if (!make_errors(pm, 6, 3, WRITE_BDHI))
+      return;
+#else
+   UNUSED(pm)
+#endif
+}
+/* This is just to validate the internal PNG formatting code - if this fails
+ * then the warning messages the library outputs will probably be garbage.
+ */
+static void
+perform_formatting_test(png_store *volatile ps)
+{
+#ifdef PNG_TIME_RFC1123_SUPPORTED
+   /* The handle into the formatting code is the RFC1123 support; this test does
+    * nothing if that is compiled out.
+    */
+   context(ps, fault);
+   Try
+   {
+      png_const_charp correct = "29 Aug 2079 13:53:60 +0000";
+      png_const_charp result;
+      png_structp pp;
+      png_time pt;
+      pp = set_store_for_write(ps, NULL, "libpng formatting test");
+      if (pp == NULL)
+         Throw ps;
+      /* Arbitrary settings: */
+      pt.year = 2079;
+      pt.month = 8;
+      pt.day = 29;
+      pt.hour = 13;
+      pt.minute = 53;
+      pt.second = 60; /* a leap second */
+      result = png_convert_to_rfc1123(pp, &pt);
+      if (result == NULL)
+         png_error(pp, "png_convert_to_rfc1123 failed");
+      if (strcmp(result, correct) != 0)
+      {
+         size_t pos = 0;
+         char msg[128];
+         pos = safecat(msg, sizeof msg, pos, "png_convert_to_rfc1123(");
+         pos = safecat(msg, sizeof msg, pos, correct);
+         pos = safecat(msg, sizeof msg, pos, ") returned: '");
+         pos = safecat(msg, sizeof msg, pos, result);
+         pos = safecat(msg, sizeof msg, pos, "'");
+         png_error(pp, msg);
+      }
+      store_write_reset(ps);
+   }
+   Catch(fault)
+   {
+      store_write_reset(fault);
+   }
+#else
+   UNUSED(ps)
+#endif
+}
+/* Because we want to use the same code in both the progressive reader and the
+ * sequential reader it is necessary to deal with the fact that the progressive
+ * reader callbacks only have one parameter (png_get_progressive_ptr()), so this
+ * must contain all the test parameters and all the local variables directly
+ * accessible to the sequential reader implementation.
+ *
+ * The technique adopted is to reinvent part of what Dijkstra termed a
+ * 'display'; an array of pointers to the stack frames of enclosing functions so
+ * that a nested function definition can access the local (C auto) variables of
+ * the functions that contain its definition.  In fact C provides the first
+ * pointer (the local variables - the stack frame pointer) and the last (the
+ * global variables - the BCPL global vector typically implemented as global
+ * addresses), this code requires one more pointer to make the display - the
+ * local variables (and function call parameters) of the function that actually
+ * invokes either the progressive or sequential reader.
+ *
+ * Perhaps confusingly this technique is confounded with classes - the
+ * 'standard_display' defined here is sub-classed as the 'gamma_display' below.
+ * A gamma_display is a standard_display, taking advantage of the ANSI-C
+ * requirement that the pointer to the first member of a structure must be the
+ * same as the pointer to the structure.  This allows us to reuse standard_
+ * functions in the gamma test code; something that could not be done with
+ * nested functions!
+ */
+typedef struct standard_display
+{
+   png_store*  ps;             /* Test parameters (passed to the function) */
+   png_byte    colour_type;
+   png_byte    bit_depth;
+   png_byte    red_sBIT;       /* Input data sBIT values. */
+   png_byte    green_sBIT;
+   png_byte    blue_sBIT;
+   png_byte    alpha_sBIT;
+   int         interlace_type;
+   png_uint_32 id;             /* Calculated file ID */
+   png_uint_32 w;              /* Width of image */
+   png_uint_32 h;              /* Height of image */
+   int         npasses;        /* Number of interlaced passes */
+   png_uint_32 pixel_size;     /* Width of one pixel in bits */
+   png_uint_32 bit_width;      /* Width of output row in bits */
+   size_t      cbRow;          /* Bytes in a row of the output image */
+   int         do_interlace;   /* Do interlacing internally */
+   int         is_transparent; /* Transparency information was present. */
+   int         speed;          /* Doing a speed test */
+   int         use_update_info;/* Call update_info, not start_image */
+   struct
+   {
+      png_uint_16 red;
+      png_uint_16 green;
+      png_uint_16 blue;
+   }           transparent;    /* The transparent color, if set. */
+   int         npalette;       /* Number of entries in the palette. */
+   store_palette
+               palette;
+} standard_display;
+static void
+standard_display_init(standard_display *dp, png_store* ps, png_uint_32 id,
+   int do_interlace, int use_update_info)
+{
+   memset(dp, 0, sizeof *dp);
+   dp->ps = ps;
+   dp->colour_type = COL_FROM_ID(id);
+   dp->bit_depth = DEPTH_FROM_ID(id);
+   if (dp->bit_depth < 1 || dp->bit_depth > 16)
+      internal_error(ps, "internal: bad bit depth");
+   if (dp->colour_type == 3)
+      dp->red_sBIT = dp->blue_sBIT = dp->green_sBIT = dp->alpha_sBIT = 8;
+   else
+      dp->red_sBIT = dp->blue_sBIT = dp->green_sBIT = dp->alpha_sBIT =
+         dp->bit_depth;
+   dp->interlace_type = INTERLACE_FROM_ID(id);
+   dp->id = id;
+   /* All the rest are filled in after the read_info: */
+   dp->w = 0;
+   dp->h = 0;
+   dp->npasses = 0;
+   dp->pixel_size = 0;
+   dp->bit_width = 0;
+   dp->cbRow = 0;
+   dp->do_interlace = do_interlace;
+   dp->is_transparent = 0;
+   dp->speed = ps->speed;
+   dp->use_update_info = use_update_info;
+   dp->npalette = 0;
+   /* Preset the transparent color to black: */
+   memset(&dp->transparent, 0, sizeof dp->transparent);
+   /* Preset the palette to full intensity/opaque througout: */
+   memset(dp->palette, 0xff, sizeof dp->palette);
+}
+/* Initialize the palette fields - this must be done later because the palette
+ * comes from the particular png_store_file that is selected.
+ */
+static void
+standard_palette_init(standard_display *dp)
+{
+   store_palette_entry *palette = store_current_palette(dp->ps, &dp->npalette);
+   /* The remaining entries remain white/opaque. */
+   if (dp->npalette > 0)
+   {
+      int i = dp->npalette;
+      memcpy(dp->palette, palette, i * sizeof *palette);
+      /* Check for a non-opaque palette entry: */
+      while (--i >= 0)
+         if (palette[i].alpha < 255)
+            break;
+#     ifdef __GNUC__
+         /* GCC can't handle the more obviously optimizable version. */
+         if (i >= 0)
+            dp->is_transparent = 1;
+         else
+            dp->is_transparent = 0;
+#     else
+         dp->is_transparent = (i >= 0);
+#     endif
+   }
+}
+/* Utility to read the palette from the PNG file and convert it into
+ * store_palette format.  This returns 1 if there is any transparency in the
+ * palette (it does not check for a transparent colour in the non-palette case.)
+ */
+static int
+read_palette(store_palette palette, int *npalette, png_structp pp, png_infop pi)
+{
+   png_colorp pal;
+   png_bytep trans_alpha;
+   int num;
+   pal = 0;
+   *npalette = -1;
+   if (png_get_PLTE(pp, pi, &pal, npalette) & PNG_INFO_PLTE)
+   {
+      int i = *npalette;
+      if (i <= 0 || i > 256)
+         png_error(pp, "validate: invalid PLTE count");
+      while (--i >= 0)
+      {
+         palette[i].red = pal[i].red;
+         palette[i].green = pal[i].green;
+         palette[i].blue = pal[i].blue;
+      }
+      /* Mark the remainder of the entries with a flag value (other than
+       * white/opaque which is the flag value stored above.)
+       */
+      memset(palette + *npalette, 126, (256-*npalette) * sizeof *palette);
+   }
+   else /* !png_get_PLTE */
+   {
+      if (*npalette != (-1))
+         png_error(pp, "validate: invalid PLTE result");
+      /* But there is no palette, so record this: */
+      *npalette = 0;
+      memset(palette, 113, sizeof (store_palette));
+   }
+   trans_alpha = 0;
+   num = 2; /* force error below */
+   if ((png_get_tRNS(pp, pi, &trans_alpha, &num, 0) & PNG_INFO_tRNS) != 0 &&
+      (trans_alpha != NULL || num != 1/*returns 1 for a transparent color*/) &&
+      /* Oops, if a palette tRNS gets expanded png_read_update_info (at least so
+       * far as 1.5.4) does not remove the trans_alpha pointer, only num_trans,
+       * so in the above call we get a success, we get a pointer (who knows what
+       * to) and we get num_trans == 0:
+       */
+      !(trans_alpha != NULL && num == 0)) /* TODO: fix this in libpng. */
+   {
+      int i;
+      /* Any of these are crash-worthy - given the implementation of
+       * png_get_tRNS up to 1.5 an app won't crash if it just checks the
+       * result above and fails to check that the variables it passed have
+       * actually been filled in!  Note that if the app were to pass the
+       * last, png_color_16p, variable too it couldn't rely on this.
+       */
+      if (trans_alpha == NULL || num <= 0 || num > 256 || num > *npalette)
+         png_error(pp, "validate: unexpected png_get_tRNS (palette) result");
+      for (i=0; i<num; ++i)
+         palette[i].alpha = trans_alpha[i];
+      for (num=*npalette; i<num; ++i)
+         palette[i].alpha = 255;
+      for (; i<256; ++i)
+         palette[i].alpha = 33; /* flag value */
+      return 1; /* transparency */
+   }
+   else
+   {
+      /* No palette transparency - just set the alpha channel to opaque. */
+      int i;
+      for (i=0, num=*npalette; i<num; ++i)
+         palette[i].alpha = 255;
+      for (; i<256; ++i)
+         palette[i].alpha = 55; /* flag value */
+      return 0; /* no transparency */
+   }
+}
+/* Utility to validate the palette if it should not have changed (the
+ * non-transform case).
+ */
+static void
+standard_palette_validate(standard_display *dp, png_structp pp, png_infop pi)
+{
+   int npalette;
+   store_palette palette;
+   if (read_palette(palette, &npalette, pp, pi) != dp->is_transparent)
+      png_error(pp, "validate: palette transparency changed");
+   if (npalette != dp->npalette)
+   {
+      size_t pos = 0;
+      char msg[64];
+      pos = safecat(msg, sizeof msg, pos, "validate: palette size changed: ");
+      pos = safecatn(msg, sizeof msg, pos, dp->npalette);
+      pos = safecat(msg, sizeof msg, pos, " -> ");
+      pos = safecatn(msg, sizeof msg, pos, npalette);
+      png_error(pp, msg);
+   }
+   {
+      int i = npalette; /* npalette is aliased */
+      while (--i >= 0)
+         if (palette[i].red != dp->palette[i].red ||
+            palette[i].green != dp->palette[i].green ||
+            palette[i].blue != dp->palette[i].blue ||
+            palette[i].alpha != dp->palette[i].alpha)
+            png_error(pp, "validate: PLTE or tRNS chunk changed");
+   }
+}
+/* By passing a 'standard_display' the progressive callbacks can be used
+ * directly by the sequential code, the functions suffixed "_imp" are the
+ * implementations, the functions without the suffix are the callbacks.
+ *
+ * The code for the info callback is split into two because this callback calls
+ * png_read_update_info or png_start_read_image and what gets called depends on
+ * whether the info needs updating (we want to test both calls in pngvalid.)
+ */
+static void
+standard_info_part1(standard_display *dp, png_structp pp, png_infop pi)
+{
+   if (png_get_bit_depth(pp, pi) != dp->bit_depth)
+      png_error(pp, "validate: bit depth changed");
+   if (png_get_color_type(pp, pi) != dp->colour_type)
+      png_error(pp, "validate: color type changed");
+   if (png_get_filter_type(pp, pi) != PNG_FILTER_TYPE_BASE)
+      png_error(pp, "validate: filter type changed");
+   if (png_get_interlace_type(pp, pi) != dp->interlace_type)
+      png_error(pp, "validate: interlacing changed");
+   if (png_get_compression_type(pp, pi) != PNG_COMPRESSION_TYPE_BASE)
+      png_error(pp, "validate: compression type changed");
+   dp->w = png_get_image_width(pp, pi);
+   if (dp->w != standard_width(pp, dp->id))
+      png_error(pp, "validate: image width changed");
+   dp->h = png_get_image_height(pp, pi);
+   if (dp->h != standard_height(pp, dp->id))
+      png_error(pp, "validate: image height changed");
+   /* Record (but don't check at present) the input sBIT according to the colour
+    * type information.
+    */
+   {
+      png_color_8p sBIT = 0;
+      if (png_get_sBIT(pp, pi, &sBIT) & PNG_INFO_sBIT)
+      {
+         int sBIT_invalid = 0;
+         if (sBIT == 0)
+            png_error(pp, "validate: unexpected png_get_sBIT result");
+         if (dp->colour_type & PNG_COLOR_MASK_COLOR)
+         {
+            if (sBIT->red == 0 || sBIT->red > dp->bit_depth)
+               sBIT_invalid = 1;
+            else
+               dp->red_sBIT = sBIT->red;
+            if (sBIT->green == 0 || sBIT->green > dp->bit_depth)
+               sBIT_invalid = 1;
+            else
+               dp->green_sBIT = sBIT->green;
+            if (sBIT->blue == 0 || sBIT->blue > dp->bit_depth)
+               sBIT_invalid = 1;
+            else
+               dp->blue_sBIT = sBIT->blue;
+         }
+         else /* !COLOR */
+         {
+            if (sBIT->gray == 0 || sBIT->gray > dp->bit_depth)
+               sBIT_invalid = 1;
+            else
+               dp->blue_sBIT = dp->green_sBIT = dp->red_sBIT = sBIT->gray;
+         }
+         /* All 8 bits in tRNS for a palette image are significant - see the
+          * spec.
+          */
+         if (dp->colour_type & PNG_COLOR_MASK_ALPHA)
+         {
+            if (sBIT->alpha == 0 || sBIT->alpha > dp->bit_depth)
+               sBIT_invalid = 1;
+            else
+               dp->alpha_sBIT = sBIT->alpha;
+         }
+         if (sBIT_invalid)
+            png_error(pp, "validate: sBIT value out of range");
+      }
+   }
+   /* Important: this is validating the value *before* any transforms have been
+    * put in place.  It doesn't matter for the standard tests, where there are
+    * no transforms, but it does for other tests where rowbytes may change after
+    * png_read_update_info.
+    */
+   if (png_get_rowbytes(pp, pi) != standard_rowsize(pp, dp->id))
+      png_error(pp, "validate: row size changed");
+   /* Validate the colour type 3 palette (this can be present on other color
+    * types.)
+    */
+   standard_palette_validate(dp, pp, pi);
+   /* In any case always check for a tranparent color (notice that the
+    * colour type 3 case must not give a successful return on the get_tRNS call
+    * with these arguments!)
+    */
+   {
+      png_color_16p trans_color = 0;
+      if (png_get_tRNS(pp, pi, 0, 0, &trans_color) & PNG_INFO_tRNS)
+      {
+         if (trans_color == 0)
+            png_error(pp, "validate: unexpected png_get_tRNS (color) result");
+         switch (dp->colour_type)
+         {
+         case 0:
+            dp->transparent.red = dp->transparent.green = dp->transparent.blue =
+               trans_color->gray;
+            dp->is_transparent = 1;
+            break;
+         case 2:
+            dp->transparent.red = trans_color->red;
+            dp->transparent.green = trans_color->green;
+            dp->transparent.blue = trans_color->blue;
+            dp->is_transparent = 1;
+            break;
+         case 3:
+            /* Not expected because it should result in the array case
+             * above.
+             */
+            png_error(pp, "validate: unexpected png_get_tRNS result");
+            break;
+         default:
+            png_error(pp, "validate: invalid tRNS chunk with alpha image");
+         }
+      }
+   }
+   /* Read the number of passes - expected to match the value used when
+    * creating the image (interlaced or not).  This has the side effect of
+    * turning on interlace handling (if do_interlace is not set.)
+    */
+   dp->npasses = npasses_from_interlace_type(pp, dp->interlace_type);
+   if (!dp->do_interlace && dp->npasses != png_set_interlace_handling(pp))
+      png_error(pp, "validate: file changed interlace type");
+   /* Caller calls png_read_update_info or png_start_read_image now, then calls
+    * part2.
+    */
+}
+/* This must be called *after* the png_read_update_info call to get the correct
+ * 'rowbytes' value, otherwise png_get_rowbytes will refer to the untransformed
+ * image.
+ */
+static void
+standard_info_part2(standard_display *dp, png_structp pp, png_infop pi,
+    int nImages)
+{
+   /* Record cbRow now that it can be found. */
+   dp->pixel_size = bit_size(pp, png_get_color_type(pp, pi),
+      png_get_bit_depth(pp, pi));
+   dp->bit_width = png_get_image_width(pp, pi) * dp->pixel_size;
+   dp->cbRow = png_get_rowbytes(pp, pi);
+   /* Validate the rowbytes here again. */
+   if (dp->cbRow != (dp->bit_width+7)/8)
+      png_error(pp, "bad png_get_rowbytes calculation");
+   /* Then ensure there is enough space for the output image(s). */
+   store_ensure_image(dp->ps, pp, nImages, dp->cbRow, dp->h);
+}
+static void
+standard_info_imp(standard_display *dp, png_structp pp, png_infop pi,
+    int nImages)
+{
+   /* Note that the validation routine has the side effect of turning on
+    * interlace handling in the subsequent code.
+    */
+   standard_info_part1(dp, pp, pi);
+   /* And the info callback has to call this (or png_read_update_info - see
+    * below in the png_modifier code for that variant.
+    */
+   if (dp->use_update_info)
+   {
+      /* For debugging the effect of multiple calls: */
+      int i = dp->use_update_info;
+      while (i-- > 0)
+         png_read_update_info(pp, pi);
+   }
+   else
+      png_start_read_image(pp);
+   /* Validate the height, width and rowbytes plus ensure that sufficient buffer
+    * exists for decoding the image.
+    */
+   standard_info_part2(dp, pp, pi, nImages);
+}
+static void
+standard_info(png_structp pp, png_infop pi)
+{
+   standard_display *dp = voidcast(standard_display*,
+      png_get_progressive_ptr(pp));
+   /* Call with nImages==1 because the progressive reader can only produce one
+    * image.
+    */
+   standard_info_imp(dp, pp, pi, 1 /*only one image*/);
+}
+static void
+progressive_row(png_structp pp, png_bytep new_row, png_uint_32 y, int pass)
+{
+   PNG_CONST standard_display *dp = voidcast(standard_display*,
+      png_get_progressive_ptr(pp));
+   /* When handling interlacing some rows will be absent in each pass, the
+    * callback still gets called, but with a NULL pointer.  This is checked
+    * in the 'else' clause below.  We need our own 'cbRow', but we can't call
+    * png_get_rowbytes because we got no info structure.
+    */
+   if (new_row != NULL)
+   {
+      png_bytep row;
+      /* In the case where the reader doesn't do the interlace it gives
+       * us the y in the sub-image:
+       */
+      if (dp->do_interlace && dp->interlace_type == PNG_INTERLACE_ADAM7)
+      {
+#ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED
+         /* Use this opportunity to validate the png 'current' APIs: */
+         if (y != png_get_current_row_number(pp))
+            png_error(pp, "png_get_current_row_number is broken");
+         if (pass != png_get_current_pass_number(pp))
+            png_error(pp, "png_get_current_pass_number is broken");
+#endif
+         y = PNG_ROW_FROM_PASS_ROW(y, pass);
+      }
+      /* Validate this just in case. */
+      if (y >= dp->h)
+         png_error(pp, "invalid y to progressive row callback");
+      row = store_image_row(dp->ps, pp, 0, y);
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+      /* Combine the new row into the old: */
+      if (dp->do_interlace)
+      {
+         if (dp->interlace_type == PNG_INTERLACE_ADAM7)
+            deinterlace_row(row, new_row, dp->pixel_size, dp->w, pass);
+         else
+            row_copy(row, new_row, dp->pixel_size * dp->w);
+      }
+      else
+         png_progressive_combine_row(pp, row, new_row);
+   } else if (dp->interlace_type == PNG_INTERLACE_ADAM7 &&
+      PNG_ROW_IN_INTERLACE_PASS(y, pass) &&
+      PNG_PASS_COLS(dp->w, pass) > 0)
+      png_error(pp, "missing row in progressive de-interlacing");
+#endif /* PNG_READ_INTERLACING_SUPPORTED */
+}
+static void
+sequential_row(standard_display *dp, png_structp pp, png_infop pi,
+    PNG_CONST int iImage, PNG_CONST int iDisplay)
+{
+   PNG_CONST int         npasses = dp->npasses;
+   PNG_CONST int         do_interlace = dp->do_interlace &&
+      dp->interlace_type == PNG_INTERLACE_ADAM7;
+   PNG_CONST png_uint_32 height = standard_height(pp, dp->id);
+   PNG_CONST png_uint_32 width = standard_width(pp, dp->id);
+   PNG_CONST png_store*  ps = dp->ps;
+   int pass;
+   for (pass=0; pass<npasses; ++pass)
+   {
+      png_uint_32 y;
+      png_uint_32 wPass = PNG_PASS_COLS(width, pass);
+      for (y=0; y<height; ++y)
+      {
+         if (do_interlace)
+         {
+            /* wPass may be zero or this row may not be in this pass.
+             * png_read_row must not be called in either case.
+             */
+            if (wPass > 0 && PNG_ROW_IN_INTERLACE_PASS(y, pass))
+            {
+               /* Read the row into a pair of temporary buffers, then do the
+                * merge here into the output rows.
+                */
+               png_byte row[STANDARD_ROWMAX], display[STANDARD_ROWMAX];
+               /* The following aids (to some extent) error detection - we can
+                * see where png_read_row wrote.  Use opposite values in row and
+                * display to make this easier.  Don't use 0xff (which is used in
+                * the image write code to fill unused bits) or 0 (which is a
+                * likely value to overwrite unused bits with).
+                */
+               memset(row, 0xc5, sizeof row);
+               memset(display, 0x5c, sizeof display);
+               png_read_row(pp, row, display);
+               if (iImage >= 0)
+                  deinterlace_row(store_image_row(ps, pp, iImage, y), row,
+                     dp->pixel_size, dp->w, pass);
+               if (iDisplay >= 0)
+                  deinterlace_row(store_image_row(ps, pp, iDisplay, y), display,
+                     dp->pixel_size, dp->w, pass);
+            }
+         }
+         else
+            png_read_row(pp,
+               iImage >= 0 ? store_image_row(ps, pp, iImage, y) : NULL,
+               iDisplay >= 0 ? store_image_row(ps, pp, iDisplay, y) : NULL);
+      }
+   }
+   /* And finish the read operation (only really necessary if the caller wants
+    * to find additional data in png_info from chunks after the last IDAT.)
+    */
+   png_read_end(pp, pi);
+}
+static void
+standard_row_validate(standard_display *dp, png_structp pp,
+   int iImage, int iDisplay, png_uint_32 y)
+{
+   int where;
+   png_byte std[STANDARD_ROWMAX];
+   /* The row must be pre-initialized to the magic number here for the size
+    * tests to pass:
+    */
+   memset(std, 178, sizeof std);
+   standard_row(pp, std, dp->id, y);
+   /* At the end both the 'row' and 'display' arrays should end up identical.
+    * In earlier passes 'row' will be partially filled in, with only the pixels
+    * that have been read so far, but 'display' will have those pixels
+    * replicated to fill the unread pixels while reading an interlaced image.
+#if PNG_LIBPNG_VER < 10506
+    * The side effect inside the libpng sequential reader is that the 'row'
+    * array retains the correct values for unwritten pixels within the row
+    * bytes, while the 'display' array gets bits off the end of the image (in
+    * the last byte) trashed.  Unfortunately in the progressive reader the
+    * row bytes are always trashed, so we always do a pixel_cmp here even though
+    * a memcmp of all cbRow bytes will succeed for the sequential reader.
+#endif
+    */
+   if (iImage >= 0 &&
+      (where = pixel_cmp(std, store_image_row(dp->ps, pp, iImage, y),
+            dp->bit_width)) != 0)
+   {
+      char msg[64];
+      sprintf(msg, "PNG image row[%d][%d] changed from %.2x to %.2x", y,
+         where-1, std[where-1],
+         store_image_row(dp->ps, pp, iImage, y)[where-1]);
+      png_error(pp, msg);
+   }
+#if PNG_LIBPNG_VER < 10506
+   /* In this case use pixel_cmp because we need to compare a partial
+    * byte at the end of the row if the row is not an exact multiple
+    * of 8 bits wide.  (This is fixed in libpng-1.5.6 and pixel_cmp is
+    * changed to match!)
+    */
+#endif
+   if (iDisplay >= 0 &&
+      (where = pixel_cmp(std, store_image_row(dp->ps, pp, iDisplay, y),
+         dp->bit_width)) != 0)
+   {
+      char msg[64];
+      sprintf(msg, "display  row[%d][%d] changed from %.2x to %.2x", y,
+         where-1, std[where-1],
+         store_image_row(dp->ps, pp, iDisplay, y)[where-1]);
+      png_error(pp, msg);
+   }
+}
+static void
+standard_image_validate(standard_display *dp, png_structp pp, int iImage,
+    int iDisplay)
+{
+   png_uint_32 y;
+   if (iImage >= 0)
+      store_image_check(dp->ps, pp, iImage);
+   if (iDisplay >= 0)
+      store_image_check(dp->ps, pp, iDisplay);
+   for (y=0; y<dp->h; ++y)
+      standard_row_validate(dp, pp, iImage, iDisplay, y);
+   /* This avoids false positives if the validation code is never called! */
+   dp->ps->validated = 1;
+}
+static void
+standard_end(png_structp pp, png_infop pi)
+{
+   standard_display *dp = voidcast(standard_display*,
+      png_get_progressive_ptr(pp));
+   UNUSED(pi)
+   /* Validate the image - progressive reading only produces one variant for
+    * interlaced images.
+    */
+   standard_image_validate(dp, pp, 0, -1);
+}
+/* A single test run checking the standard image to ensure it is not damaged. */
+static void
+standard_test(png_store* PNG_CONST psIn, png_uint_32 PNG_CONST id,
+   int do_interlace, int use_update_info)
+{
+   standard_display d;
+   context(psIn, fault);
+   /* Set up the display (stack frame) variables from the arguments to the
+    * function and initialize the locals that are filled in later.
+    */
+   standard_display_init(&d, psIn, id, do_interlace, use_update_info);
+   /* Everything is protected by a Try/Catch.  The functions called also
+    * typically have local Try/Catch blocks.
+    */
+   Try
+   {
+      png_structp pp;
+      png_infop pi;
+      /* Get a png_struct for reading the image. This will throw an error if it
+       * fails, so we don't need to check the result.
+       */
+      pp = set_store_for_read(d.ps, &pi, d.id,
+         d.do_interlace ?  (d.ps->progressive ?
+            "pngvalid progressive deinterlacer" :
+            "pngvalid sequential deinterlacer") : (d.ps->progressive ?
+               "progressive reader" : "sequential reader"));
+      /* Initialize the palette correctly from the png_store_file. */
+      standard_palette_init(&d);
+      /* Introduce the correct read function. */
+      if (d.ps->progressive)
+      {
+         png_set_progressive_read_fn(pp, &d, standard_info, progressive_row,
+            standard_end);
+         /* Now feed data into the reader until we reach the end: */
+         store_progressive_read(d.ps, pp, pi);
+      }
+      else
+      {
+         /* Note that this takes the store, not the display. */
+         png_set_read_fn(pp, d.ps, store_read);
+         /* Check the header values: */
+         png_read_info(pp, pi);
+         /* The code tests both versions of the images that the sequential
+          * reader can produce.
+          */
+         standard_info_imp(&d, pp, pi, 2 /*images*/);
+         /* Need the total bytes in the image below; we can't get to this point
+          * unless the PNG file values have been checked against the expected
+          * values.
+          */
+         {
+            sequential_row(&d, pp, pi, 0, 1);
+            /* After the last pass loop over the rows again to check that the
+             * image is correct.
+             */
+            if (!d.speed)
+               standard_image_validate(&d, pp, 0, 1);
+            else
+               d.ps->validated = 1;
+         }
+      }
+      /* Check for validation. */
+      if (!d.ps->validated)
+         png_error(pp, "image read failed silently");
+      /* Successful completion. */
+   }
+   Catch(fault)
+      d.ps = fault; /* make sure this hasn't been clobbered. */
+   /* In either case clean up the store. */
+   store_read_reset(d.ps);
+}
+static int
+test_standard(png_modifier* PNG_CONST pm, png_byte PNG_CONST colour_type,
+    int bdlo, int PNG_CONST bdhi)
+{
+   for (; bdlo <= bdhi; ++bdlo)
+   {
+      int interlace_type;
+      for (interlace_type = PNG_INTERLACE_NONE;
+           interlace_type < PNG_INTERLACE_LAST; ++interlace_type)
+      {
+         standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/,
+            interlace_type, 0, 0, 0), 0/*do_interlace*/, pm->use_update_info);
+         if (fail(pm))
+            return 0;
+      }
+   }
+   return 1; /* keep going */
+}
+static void
+perform_standard_test(png_modifier *pm)
+{
+   /* Test each colour type over the valid range of bit depths (expressed as
+    * log2(bit_depth) in turn, stop as soon as any error is detected.
+    */
+   if (!test_standard(pm, 0, 0, READ_BDHI))
+      return;
+   if (!test_standard(pm, 2, 3, READ_BDHI))
+      return;
+   if (!test_standard(pm, 3, 0, 3))
+      return;
+   if (!test_standard(pm, 4, 3, READ_BDHI))
+      return;
+   if (!test_standard(pm, 6, 3, READ_BDHI))
+      return;
+}
+/********************************** SIZE TESTS ********************************/
+static int
+test_size(png_modifier* PNG_CONST pm, png_byte PNG_CONST colour_type,
+    int bdlo, int PNG_CONST bdhi)
+{
+   /* Run the tests on each combination.
+    *
+    * NOTE: on my 32 bit x86 each of the following blocks takes
+    * a total of 3.5 seconds if done across every combo of bit depth
+    * width and height.  This is a waste of time in practice, hence the
+    * hinc and winc stuff:
+    */
+   static PNG_CONST png_byte hinc[] = {1, 3, 11, 1, 5};
+   static PNG_CONST png_byte winc[] = {1, 9, 5, 7, 1};
+   for (; bdlo <= bdhi; ++bdlo)
+   {
+      png_uint_32 h, w;
+      for (h=1; h<=16; h+=hinc[bdlo]) for (w=1; w<=16; w+=winc[bdlo])
+      {
+         /* First test all the 'size' images against the sequential
+          * reader using libpng to deinterlace (where required.)  This
+          * validates the write side of libpng.  There are four possibilities
+          * to validate.
+          */
+         standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/,
+            PNG_INTERLACE_NONE, w, h, 0), 0/*do_interlace*/,
+            pm->use_update_info);
+         if (fail(pm))
+            return 0;
+         standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/,
+            PNG_INTERLACE_NONE, w, h, 1), 0/*do_interlace*/,
+            pm->use_update_info);
+         if (fail(pm))
+            return 0;
+         standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/,
+            PNG_INTERLACE_ADAM7, w, h, 0), 0/*do_interlace*/,
+            pm->use_update_info);
+         if (fail(pm))
+            return 0;
+         standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/,
+            PNG_INTERLACE_ADAM7, w, h, 1), 0/*do_interlace*/,
+            pm->use_update_info);
+         if (fail(pm))
+            return 0;
+         /* Now validate the interlaced read side - do_interlace true,
+          * in the progressive case this does actually make a difference
+          * to the code used in the non-interlaced case too.
+          */
+         standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/,
+            PNG_INTERLACE_NONE, w, h, 0), 1/*do_interlace*/,
+            pm->use_update_info);
+         if (fail(pm))
+            return 0;
+         standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/,
+            PNG_INTERLACE_ADAM7, w, h, 0), 1/*do_interlace*/,
+            pm->use_update_info);
+         if (fail(pm))
+            return 0;
+      }
+   }
+   return 1; /* keep going */
+}
+static void
+perform_size_test(png_modifier *pm)
+{
+   /* Test each colour type over the valid range of bit depths (expressed as
+    * log2(bit_depth) in turn, stop as soon as any error is detected.
+    */
+   if (!test_size(pm, 0, 0, READ_BDHI))
+      return;
+   if (!test_size(pm, 2, 3, READ_BDHI))
+      return;
+   /* For the moment don't do the palette test - it's a waste of time when
+    * compared to the grayscale test.
+    */
+#if 0
+   if (!test_size(pm, 3, 0, 3))
+      return;
+#endif
+   if (!test_size(pm, 4, 3, READ_BDHI))
+      return;
+   if (!test_size(pm, 6, 3, READ_BDHI))
+      return;
+}
+/******************************* TRANSFORM TESTS ******************************/
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+/* A set of tests to validate libpng image transforms.  The possibilities here
+ * are legion because the transforms can be combined in a combinatorial
+ * fashion.  To deal with this some measure of restraint is required, otherwise
+ * the tests would take forever.
+ */
+typedef struct image_pixel
+{
+   /* A local (pngvalid) representation of a PNG pixel, in all its
+    * various forms.
+    */
+   unsigned int red, green, blue, alpha; /* For non-palette images. */
+   unsigned int palette_index;           /* For a palette image. */
+   png_byte colour_type;                 /* As in the spec. */
+   png_byte bit_depth;                   /* Defines bit size in row */
+   png_byte sample_depth;                /* Scale of samples */
+   int      have_tRNS;                   /* tRNS chunk may need processing */
+   /* For checking the code calculates double precision floating point values
+    * along with an error value, accumulated from the transforms.  Because an
+    * sBIT setting allows larger error bounds (indeed, by the spec, apparently
+    * up to just less than +/-1 in the scaled value) the *lowest* sBIT for each
+    * channel is stored.  This sBIT value is folded in to the stored error value
+    * at the end of the application of the transforms to the pixel.
+    */
+   double   redf, greenf, bluef, alphaf;
+   double   rede, greene, bluee, alphae;
+   png_byte red_sBIT, green_sBIT, blue_sBIT, alpha_sBIT;
+} image_pixel;
+/* Shared utility function, see below. */
+static void
+image_pixel_setf(image_pixel *this, unsigned int max)
+{
+   this->redf = this->red / (double)max;
+   this->greenf = this->green / (double)max;
+   this->bluef = this->blue / (double)max;
+   this->alphaf = this->alpha / (double)max;
+   if (this->red < max)
+      this->rede = this->redf * DBL_EPSILON;
+   else
+      this->rede = 0;
+   if (this->green < max)
+      this->greene = this->greenf * DBL_EPSILON;
+   else
+      this->greene = 0;
+   if (this->blue < max)
+      this->bluee = this->bluef * DBL_EPSILON;
+   else
+      this->bluee = 0;
+   if (this->alpha < max)
+      this->alphae = this->alphaf * DBL_EPSILON;
+   else
+      this->alphae = 0;
+}
+/* Initialize the structure for the next pixel - call this before doing any
+ * transforms and call it for each pixel since all the fields may need to be
+ * reset.
+ */
+static void
+image_pixel_init(image_pixel *this, png_const_bytep row, png_byte colour_type,
+    png_byte bit_depth, png_uint_32 x, store_palette palette)
+{
+   PNG_CONST png_byte sample_depth = (png_byte)(colour_type ==
+      PNG_COLOR_TYPE_PALETTE ? 8 : bit_depth);
+   PNG_CONST unsigned int max = (1U<<sample_depth)-1;
+   /* Initially just set everything to the same number and the alpha to opaque.
+    * Note that this currently assumes a simple palette where entry x has colour
+    * rgb(x,x,x)!
+    */
+   this->palette_index = this->red = this->green = this->blue =
+      sample(row, colour_type, bit_depth, x, 0);
+   this->alpha = max;
+   this->red_sBIT = this->green_sBIT = this->blue_sBIT = this->alpha_sBIT =
+      sample_depth;
+   /* Then override as appropriate: */
+   if (colour_type == 3) /* palette */
+   {
+      /* This permits the caller to default to the sample value. */
+      if (palette != 0)
+      {
+         PNG_CONST unsigned int i = this->palette_index;
+         this->red = palette[i].red;
+         this->green = palette[i].green;
+         this->blue = palette[i].blue;
+         this->alpha = palette[i].alpha;
+      }
+   }
+   else /* not palette */
+   {
+      unsigned int i = 0;
+      if (colour_type & 2)
+      {
+         this->green = sample(row, colour_type, bit_depth, x, 1);
+         this->blue = sample(row, colour_type, bit_depth, x, 2);
+         i = 2;
+      }
+      if (colour_type & 4)
+         this->alpha = sample(row, colour_type, bit_depth, x, ++i);
+   }
+   /* Calculate the scaled values, these are simply the values divided by
+    * 'max' and the error is initialized to the double precision epsilon value
+    * from the header file.
+    */
+   image_pixel_setf(this, max);
+   /* Store the input information for use in the transforms - these will
+    * modify the information.
+    */
+   this->colour_type = colour_type;
+   this->bit_depth = bit_depth;
+   this->sample_depth = sample_depth;
+   this->have_tRNS = 0;
+}
+/* Convert a palette image to an rgb image.  This necessarily converts the tRNS
+ * chunk at the same time, because the tRNS will be in palette form.  The way
+ * palette validation works means that the original palette is never updated,
+ * instead the image_pixel value from the row contains the RGB of the
+ * corresponding palette entry and *this* is updated.  Consequently this routine
+ * only needs to change the colour type information.
+ */
+static void
+image_pixel_convert_PLTE(image_pixel *this)
+{
+   if (this->colour_type == PNG_COLOR_TYPE_PALETTE)
+   {
+      if (this->have_tRNS)
+      {
+         this->colour_type = PNG_COLOR_TYPE_RGB_ALPHA;
+         this->have_tRNS = 0;
+      }
+      else
+         this->colour_type = PNG_COLOR_TYPE_RGB;
+      /* The bit depth of the row changes at this point too (notice that this is
+       * the row format, not the sample depth, which is separate.)
+       */
+      this->bit_depth = 8;
+   }
+}
+/* Add an alpha channel; this will import the tRNS information because tRNS is
+ * not valid in an alpha image.  The bit depth will invariably be set to at
+ * least 8.  Palette images will be converted to alpha (using the above API).
+ */
+static void
+image_pixel_add_alpha(image_pixel *this, PNG_CONST standard_display *display)
+{
+   if (this->colour_type == PNG_COLOR_TYPE_PALETTE)
+      image_pixel_convert_PLTE(this);
+   if ((this->colour_type & PNG_COLOR_MASK_ALPHA) == 0)
+   {
+      if (this->colour_type == PNG_COLOR_TYPE_GRAY)
+      {
+         if (this->bit_depth < 8)
+            this->bit_depth = 8;
+         if (this->have_tRNS)
+         {
+            this->have_tRNS = 0;
+            /* Check the input, original, channel value here against the
+             * original tRNS gray chunk valie.
+             */
+            if (this->red == display->transparent.red)
+               this->alphaf = 0;
+            else
+               this->alphaf = 1;
+         }
+         else
+            this->alphaf = 1;
+         this->colour_type = PNG_COLOR_TYPE_GRAY_ALPHA;
+      }
+      else if (this->colour_type == PNG_COLOR_TYPE_RGB)
+      {
+         if (this->have_tRNS)
+         {
+            this->have_tRNS = 0;
+            /* Again, check the exact input values, not the current transformed
+             * value!
+             */
+            if (this->red == display->transparent.red &&
+               this->green == display->transparent.green &&
+               this->blue == display->transparent.blue)
+               this->alphaf = 0;
+            else
+               this->alphaf = 1;
+            this->colour_type = PNG_COLOR_TYPE_RGB_ALPHA;
+         }
+      }
+      /* The error in the alpha is zero and the sBIT value comes from the
+       * original sBIT data (actually it will always be the original bit depth).
+       */
+      this->alphae = 0;
+      this->alpha_sBIT = display->alpha_sBIT;
+   }
+}
+struct transform_display;
+typedef struct image_transform
+{
+   /* The name of this transform: a string. */
+   PNG_CONST char *name;
+   /* Each transform can be disabled from the command line: */
+   int enable;
+   /* The global list of transforms; read only. */
+   struct image_transform *PNG_CONST list;
+   /* The global count of the number of times this transform has been set on an
+    * image.
+    */
+   unsigned int global_use;
+   /* The local count of the number of times this transform has been set. */
+   unsigned int local_use;
+   /* The next transform in the list, each transform must call its own next
+    * transform after it has processed the pixel successfully.
+    */
+   PNG_CONST struct image_transform *next;
+   /* A single transform for the image, expressed as a series of function
+    * callbacks and some space for values.
+    *
+    * First a callback to add any required modifications to the png_modifier;
+    * this gets called just before the modifier is set up for read.
+    */
+   void (*ini)(PNG_CONST struct image_transform *this,
+      struct transform_display *that);
+   /* And a callback to set the transform on the current png_read_struct:
+    */
+   void (*set)(PNG_CONST struct image_transform *this,
+      struct transform_display *that, png_structp pp, png_infop pi);
+   /* Then a transform that takes an input pixel in one PNG format or another
+    * and modifies it by a pngvalid implementation of the transform (thus
+    * duplicating the libpng intent without, we hope, duplicating the bugs
+    * in the libpng implementation!)  The png_structp is solely to allow error
+    * reporting via png_error and png_warning.
+    */
+   void (*mod)(PNG_CONST struct image_transform *this, image_pixel *that,
+      png_structp pp, PNG_CONST struct transform_display *display);
+   /* Add this transform to the list and return true if the transform is
+    * meaningful for this colour type and bit depth - if false then the
+    * transform should have no effect on the image so there's not a lot of
+    * point running it.
+    */
+   int (*add)(struct image_transform *this,
+      PNG_CONST struct image_transform **that, png_byte colour_type,
+      png_byte bit_depth);
+} image_transform;
+typedef struct transform_display
+{
+   standard_display this;
+   /* Parameters */
+   png_modifier*              pm;
+   PNG_CONST image_transform* transform_list;
+   /* Local variables */
+   png_byte output_colour_type;
+   png_byte output_bit_depth;
+   /* Modifications (not necessarily used.) */
+   gama_modification gama_mod;
+   chrm_modification chrm_mod;
+   srgb_modification srgb_mod;
+} transform_display;
+/* Set sRGB, cHRM and gAMA transforms as required by the current encoding. */
+static void
+transform_set_encoding(transform_display *this)
+{
+   /* Set up the png_modifier '_current' fields then use these to determine how
+    * to add appropriate chunks.
+    */
+   png_modifier *pm = this->pm;
+   modifier_set_encoding(pm);
+   if (modifier_color_encoding_is_set(pm))
+   {
+      if (modifier_color_encoding_is_sRGB(pm))
+         srgb_modification_init(&this->srgb_mod, pm, PNG_sRGB_INTENT_ABSOLUTE);
+      else
+      {
+         /* Set gAMA and cHRM separately. */
+         gama_modification_init(&this->gama_mod, pm, pm->current_gamma);
+         if (pm->current_encoding != 0)
+            chrm_modification_init(&this->chrm_mod, pm, pm->current_encoding);
+      }
+   }
+}
+/* Three functions to end the list: */
+static void
+image_transform_ini_end(PNG_CONST image_transform *this,
+   transform_display *that)
+{
+   UNUSED(this)
+   UNUSED(that)
+}
+static void
+image_transform_set_end(PNG_CONST image_transform *this,
+   transform_display *that, png_structp pp, png_infop pi)
+{
+   UNUSED(this)
+   UNUSED(that)
+   UNUSED(pp)
+   UNUSED(pi)
+}
+/* At the end of the list recalculate the output image pixel value from the
+ * double precision values set up by the preceding 'mod' calls:
+ */
+static unsigned int
+sample_scale(double sample_value, unsigned int scale)
+{
+   sample_value = floor(sample_value * scale + .5);
+   /* Return NaN as 0: */
+   if (!(sample_value > 0))
+      sample_value = 0;
+   else if (sample_value > scale)
+      sample_value = scale;
+   return (unsigned int)sample_value;
+}
+static void
+image_transform_mod_end(PNG_CONST image_transform *this, image_pixel *that,
+    png_structp pp, PNG_CONST transform_display *display)
+{
+   PNG_CONST unsigned int scale = (1U<<that->sample_depth)-1;
+   UNUSED(this)
+   UNUSED(pp)
+   UNUSED(display)
+   /* At the end recalculate the digitized red green and blue values according
+    * to the current sample_depth of the pixel.
+    *
+    * The sample value is simply scaled to the maximum, checking for over
+    * and underflow (which can both happen for some image transforms,
+    * including simple size scaling, though libpng doesn't do that at present.
+    */
+   that->red = sample_scale(that->redf, scale);
+   /* The error value is increased, at the end, according to the lowest sBIT
+    * value seen.  Common sense tells us that the intermediate integer
+    * representations are no more accurate than +/- 0.5 in the integral values,
+    * the sBIT allows the implementation to be worse than this.  In addition the
+    * PNG specification actually permits any error within the range (-1..+1),
+    * but that is ignored here.  Instead the final digitized value is compared,
+    * below to the digitized value of the error limits - this has the net effect
+    * of allowing (almost) +/-1 in the output value.  It's difficult to see how
+    * any algorithm that digitizes intermediate results can be more accurate.
+    */
+   that->rede += 1./(2*((1U<<that->red_sBIT)-1));
+   if (that->colour_type & PNG_COLOR_MASK_COLOR)
+   {
+      that->green = sample_scale(that->greenf, scale);
+      that->blue = sample_scale(that->bluef, scale);
+      that->greene += 1./(2*((1U<<that->green_sBIT)-1));
+      that->bluee += 1./(2*((1U<<that->blue_sBIT)-1));
+   }
+   else
+   {
+      that->blue = that->green = that->red;
+      that->bluef = that->greenf = that->redf;
+      that->bluee = that->greene = that->rede;
+   }
+   if ((that->colour_type & PNG_COLOR_MASK_ALPHA) ||
+      that->colour_type == PNG_COLOR_TYPE_PALETTE)
+   {
+      that->alpha = sample_scale(that->alphaf, scale);
+      that->alphae += 1./(2*((1U<<that->alpha_sBIT)-1));
+   }
+   else
+   {
+      that->alpha = scale; /* opaque */
+      that->alpha = 1;     /* Override this. */
+      that->alphae = 0;    /* It's exact ;-) */
+   }
+}
+/* Static 'end' structure: */
+static image_transform image_transform_end =
+{
+   "(end)", /* name */
+   1, /* enable */
+   0, /* list */
+   0, /* global_use */
+   0, /* local_use */
+   0, /* next */
+   image_transform_ini_end,
+   image_transform_set_end,
+   image_transform_mod_end,
+   0 /* never called, I want it to crash if it is! */
+};
+/* Reader callbacks and implementations, where they differ from the standard
+ * ones.
+ */
+static void
+transform_display_init(transform_display *dp, png_modifier *pm, png_uint_32 id,
+    PNG_CONST image_transform *transform_list)
+{
+   memset(dp, 0, sizeof *dp);
+   /* Standard fields */
+   standard_display_init(&dp->this, &pm->this, id, 0/*do_interlace*/,
+      pm->use_update_info);
+   /* Parameter fields */
+   dp->pm = pm;
+   dp->transform_list = transform_list;
+   /* Local variable fields */
+   dp->output_colour_type = 255; /* invalid */
+   dp->output_bit_depth = 255;  /* invalid */
+}
+static void
+transform_info_imp(transform_display *dp, png_structp pp, png_infop pi)
+{
+   /* Reuse the standard stuff as appropriate. */
+   standard_info_part1(&dp->this, pp, pi);
+   /* Now set the list of transforms. */
+   dp->transform_list->set(dp->transform_list, dp, pp, pi);
+   /* Update the info structure for these transforms: */
+   {
+      int i = dp->this.use_update_info;
+      /* Always do one call, even if use_update_info is 0. */
+      do
+         png_read_update_info(pp, pi);
+      while (--i > 0);
+   }
+   /* And get the output information into the standard_display */
+   standard_info_part2(&dp->this, pp, pi, 1/*images*/);
+   /* Plus the extra stuff we need for the transform tests: */
+   dp->output_colour_type = png_get_color_type(pp, pi);
+   dp->output_bit_depth = png_get_bit_depth(pp, pi);
+   /* Validate the combination of colour type and bit depth that we are getting
+    * out of libpng; the semantics of something not in the PNG spec are, at
+    * best, unclear.
+    */
+   switch (dp->output_colour_type)
+   {
+   case PNG_COLOR_TYPE_PALETTE:
+      if (dp->output_bit_depth > 8) goto error;
+      /*FALL THROUGH*/
+   case PNG_COLOR_TYPE_GRAY:
+      if (dp->output_bit_depth == 1 || dp->output_bit_depth == 2 ||
+         dp->output_bit_depth == 4)
+         break;
+      /*FALL THROUGH*/
+   default:
+      if (dp->output_bit_depth == 8 || dp->output_bit_depth == 16)
+         break;
+      /*FALL THROUGH*/
+   error:
+      {
+         char message[128];
+         size_t pos;
+         pos = safecat(message, sizeof message, 0,
+            "invalid final bit depth: colour type(");
+         pos = safecatn(message, sizeof message, pos, dp->output_colour_type);
+         pos = safecat(message, sizeof message, pos, ") with bit depth: ");
+         pos = safecatn(message, sizeof message, pos, dp->output_bit_depth);
+         png_error(pp, message);
+      }
+   }
+   /* Use a test pixel to check that the output agrees with what we expect -
+    * this avoids running the whole test if the output is unexpected.
+    */
+   {
+      image_pixel test_pixel;
+      memset(&test_pixel, 0, sizeof test_pixel);
+      test_pixel.colour_type = dp->this.colour_type; /* input */
+      test_pixel.bit_depth = dp->this.bit_depth;
+      if (test_pixel.colour_type == PNG_COLOR_TYPE_PALETTE)
+         test_pixel.sample_depth = 8;
+      else
+         test_pixel.sample_depth = test_pixel.bit_depth;
+      /* Don't need sBIT here, but it must be set to non-zero to avoid
+       * arithmetic overflows.
+       */
+      test_pixel.have_tRNS = dp->this.is_transparent;
+      test_pixel.red_sBIT = test_pixel.green_sBIT = test_pixel.blue_sBIT =
+         test_pixel.alpha_sBIT = test_pixel.sample_depth;
+      dp->transform_list->mod(dp->transform_list, &test_pixel, pp, dp);
+      if (test_pixel.colour_type != dp->output_colour_type)
+      {
+         char message[128];
+         size_t pos = safecat(message, sizeof message, 0, "colour type ");
+         pos = safecatn(message, sizeof message, pos, dp->output_colour_type);
+         pos = safecat(message, sizeof message, pos, " expected ");
+         pos = safecatn(message, sizeof message, pos, test_pixel.colour_type);
+         png_error(pp, message);
+      }
+      if (test_pixel.bit_depth != dp->output_bit_depth)
+      {
+         char message[128];
+         size_t pos = safecat(message, sizeof message, 0, "bit depth ");
+         pos = safecatn(message, sizeof message, pos, dp->output_bit_depth);
+         pos = safecat(message, sizeof message, pos, " expected ");
+         pos = safecatn(message, sizeof message, pos, test_pixel.bit_depth);
+         png_error(pp, message);
+      }
+      /* If both bit depth and colour type are correct check the sample depth.
+       * I believe these are both internal errors.
+       */
+      if (test_pixel.colour_type == PNG_COLOR_TYPE_PALETTE)
+      {
+         if (test_pixel.sample_depth != 8) /* oops - internal error! */
+            png_error(pp, "pngvalid: internal: palette sample depth not 8");
+      }
+      else if (test_pixel.sample_depth != dp->output_bit_depth)
+      {
+         char message[128];
+         size_t pos = safecat(message, sizeof message, 0,
+            "internal: sample depth ");
+         pos = safecatn(message, sizeof message, pos, dp->output_bit_depth);
+         pos = safecat(message, sizeof message, pos, " expected ");
+         pos = safecatn(message, sizeof message, pos, test_pixel.sample_depth);
+         png_error(pp, message);
+      }
+   }
+}
+static void
+transform_info(png_structp pp, png_infop pi)
+{
+   transform_info_imp(voidcast(transform_display*, png_get_progressive_ptr(pp)),
+      pp, pi);
+}
+static void
+transform_range_check(png_structp pp, unsigned int r, unsigned int g,
+   unsigned int b, unsigned int a, unsigned int in_digitized, double in,
+   unsigned int out, png_byte sample_depth, double err, double limit,
+   PNG_CONST char *name, double digitization_error)
+{
+   /* Compare the scaled, digitzed, values of our local calculation (in+-err)
+    * with the digitized values libpng produced;  'sample_depth' is the actual
+    * digitization depth of the libpng output colors (the bit depth except for
+    * palette images where it is always 8.)  The check on 'err' is to detect
+    * internal errors in pngvalid itself.
+    */
+   unsigned int max = (1U<<sample_depth)-1;
+   double in_min = ceil((in-err)*max - digitization_error);
+   double in_max = floor((in+err)*max + digitization_error);
+   if (err > limit || !(out >= in_min && out <= in_max))
+   {
+      char message[256];
+      size_t pos;
+      pos = safecat(message, sizeof message, 0, name);
+      pos = safecat(message, sizeof message, pos, " output value error: rgba(");
+      pos = safecatn(message, sizeof message, pos, r);
+      pos = safecat(message, sizeof message, pos, ",");
+      pos = safecatn(message, sizeof message, pos, g);
+      pos = safecat(message, sizeof message, pos, ",");
+      pos = safecatn(message, sizeof message, pos, b);
+      pos = safecat(message, sizeof message, pos, ",");
+      pos = safecatn(message, sizeof message, pos, a);
+      pos = safecat(message, sizeof message, pos, "): ");
+      pos = safecatn(message, sizeof message, pos, out);
+      pos = safecat(message, sizeof message, pos, " expected: ");
+      pos = safecatn(message, sizeof message, pos, in_digitized);
+      pos = safecat(message, sizeof message, pos, " (");
+      pos = safecatd(message, sizeof message, pos, (in-err)*max, 3);
+      pos = safecat(message, sizeof message, pos, "..");
+      pos = safecatd(message, sizeof message, pos, (in+err)*max, 3);
+      pos = safecat(message, sizeof message, pos, ")");
+      png_error(pp, message);
+   }
+}
+static void
+transform_image_validate(transform_display *dp, png_structp pp, png_infop pi)
+{
+   /* Constants for the loop below: */
+   PNG_CONST png_store* PNG_CONST ps = dp->this.ps;
+   PNG_CONST png_byte in_ct = dp->this.colour_type;
+   PNG_CONST png_byte in_bd = dp->this.bit_depth;
+   PNG_CONST png_uint_32 w = dp->this.w;
+   PNG_CONST png_uint_32 h = dp->this.h;
+   PNG_CONST png_byte out_ct = dp->output_colour_type;
+   PNG_CONST png_byte out_bd = dp->output_bit_depth;
+   PNG_CONST png_byte sample_depth = (png_byte)(out_ct ==
+      PNG_COLOR_TYPE_PALETTE ? 8 : out_bd);
+   PNG_CONST png_byte red_sBIT = dp->this.red_sBIT;
+   PNG_CONST png_byte green_sBIT = dp->this.green_sBIT;
+   PNG_CONST png_byte blue_sBIT = dp->this.blue_sBIT;
+   PNG_CONST png_byte alpha_sBIT = dp->this.alpha_sBIT;
+   PNG_CONST int have_tRNS = dp->this.is_transparent;
+   double digitization_error;
+   store_palette out_palette;
+   png_uint_32 y;
+   UNUSED(pi)
+   /* Check for row overwrite errors */
+   store_image_check(dp->this.ps, pp, 0);
+   /* Read the palette corresponding to the output if the output colour type
+    * indicates a palette, othewise set out_palette to garbage.
+    */
+   if (out_ct == PNG_COLOR_TYPE_PALETTE)
+   {
+      /* Validate that the palette count itself has not changed - this is not
+       * expected.
+       */
+      int npalette = (-1);
+      (void)read_palette(out_palette, &npalette, pp, pi);
+      if (npalette != dp->this.npalette)
+         png_error(pp, "unexpected change in palette size");
+      digitization_error = .5;
+   }
+   else
+   {
+      png_byte in_sample_depth;
+      memset(out_palette, 0x5e, sizeof out_palette);
+      /* assume-8-bit-calculations means assume that if the input has 8 bit
+       * (or less) samples and the output has 16 bit samples the calculations
+       * will be done with 8 bit precision, not 16.
+       *
+       * TODO: fix this in libpng; png_set_expand_16 should cause 16 bit
+       * calculations to be used throughout.
+       */
+      if (in_ct == PNG_COLOR_TYPE_PALETTE || in_bd < 16)
+         in_sample_depth = 8;
+      else
+         in_sample_depth = in_bd;
+      if (sample_depth != 16 || in_sample_depth > 8 ||
+         !dp->pm->calculations_use_input_precision)
+         digitization_error = .5;
+      /* Else errors are at 8 bit precision, scale .5 in 8 bits to the 16 bits:
+       */
+      else
+         digitization_error = .5 * 257;
+   }
+   for (y=0; y<h; ++y)
+   {
+      png_const_bytep PNG_CONST pRow = store_image_row(ps, pp, 0, y);
+      png_uint_32 x;
+      /* The original, standard, row pre-transforms. */
+      png_byte std[STANDARD_ROWMAX];
+      transform_row(pp, std, in_ct, in_bd, y);
+      /* Go through each original pixel transforming it and comparing with what
+       * libpng did to the same pixel.
+       */
+      for (x=0; x<w; ++x)
+      {
+         image_pixel in_pixel, out_pixel;
+         unsigned int r, g, b, a;
+         /* Find out what we think the pixel should be: */
+         image_pixel_init(&in_pixel, std, in_ct, in_bd, x, dp->this.palette);
+         in_pixel.red_sBIT = red_sBIT;
+         in_pixel.green_sBIT = green_sBIT;
+         in_pixel.blue_sBIT = blue_sBIT;
+         in_pixel.alpha_sBIT = alpha_sBIT;
+         in_pixel.have_tRNS = have_tRNS;
+         /* For error detection, below. */
+         r = in_pixel.red;
+         g = in_pixel.green;
+         b = in_pixel.blue;
+         a = in_pixel.alpha;
+         dp->transform_list->mod(dp->transform_list, &in_pixel, pp, dp);
+         /* Read the output pixel and compare it to what we got, we don't
+          * use the error field here, so no need to update sBIT.
+          */
+         image_pixel_init(&out_pixel, pRow, out_ct, out_bd, x, out_palette);
+         /* We don't expect changes to the index here even if the bit depth is
+          * changed.
+          */
+         if (in_ct == PNG_COLOR_TYPE_PALETTE &&
+            out_ct == PNG_COLOR_TYPE_PALETTE)
+         {
+            if (in_pixel.palette_index != out_pixel.palette_index)
+               png_error(pp, "unexpected transformed palette index");
+         }
+         /* Check the colours for palette images too - in fact the palette could
+          * be separately verified itself in most cases.
+          */
+         if (in_pixel.red != out_pixel.red)
+            transform_range_check(pp, r, g, b, a, in_pixel.red, in_pixel.redf,
+               out_pixel.red, sample_depth, in_pixel.rede,
+               dp->pm->limit + 1./(2*((1U<<in_pixel.red_sBIT)-1)), "red/gray",
+               digitization_error);
+         if ((out_ct & PNG_COLOR_MASK_COLOR) != 0 &&
+            in_pixel.green != out_pixel.green)
+            transform_range_check(pp, r, g, b, a, in_pixel.green,
+               in_pixel.greenf, out_pixel.green, sample_depth, in_pixel.greene,
+               dp->pm->limit + 1./(2*((1U<<in_pixel.green_sBIT)-1)), "green",
+               digitization_error);
+         if ((out_ct & PNG_COLOR_MASK_COLOR) != 0 &&
+            in_pixel.blue != out_pixel.blue)
+            transform_range_check(pp, r, g, b, a, in_pixel.blue, in_pixel.bluef,
+               out_pixel.blue, sample_depth, in_pixel.bluee,
+               dp->pm->limit + 1./(2*((1U<<in_pixel.blue_sBIT)-1)), "blue",
+               digitization_error);
+         if ((out_ct & PNG_COLOR_MASK_ALPHA) != 0 &&
+            in_pixel.alpha != out_pixel.alpha)
+            transform_range_check(pp, r, g, b, a, in_pixel.alpha,
+               in_pixel.alphaf, out_pixel.alpha, sample_depth, in_pixel.alphae,
+               dp->pm->limit + 1./(2*((1U<<in_pixel.alpha_sBIT)-1)), "alpha",
+               digitization_error);
+      } /* pixel (x) loop */
+   } /* row (y) loop */
+   /* Record that something was actually checked to avoid a false positive. */
+   dp->this.ps->validated = 1;
+}
+static void
+transform_end(png_structp pp, png_infop pi)
+{
+   transform_display *dp = voidcast(transform_display*,
+      png_get_progressive_ptr(pp));
+   if (!dp->this.speed)
+      transform_image_validate(dp, pp, pi);
+   else
+      dp->this.ps->validated = 1;
+}
+/* A single test run. */
+static void
+transform_test(png_modifier *pmIn, PNG_CONST png_uint_32 idIn,
+    PNG_CONST image_transform* transform_listIn, PNG_CONST char * volatile name)
+{
+   transform_display d;
+   context(&pmIn->this, fault);
+   transform_display_init(&d, pmIn, idIn, transform_listIn);
+   Try
+   {
+      size_t pos = 0;
+      png_structp pp;
+      png_infop pi;
+      char full_name[256];
+      /* Make sure the encoding fields are correct and enter the required
+       * modifications.
+       */
+      transform_set_encoding(&d);
+      /* Add any modifications required by the transform list. */
+      d.transform_list->ini(d.transform_list, &d);
+      /* Add the color space information, if any, to the name. */
+      pos = safecat(full_name, sizeof full_name, pos, name);
+      pos = safecat_current_encoding(full_name, sizeof full_name, pos, d.pm);
+      /* Get a png_struct for reading the image. */
+      pp = set_modifier_for_read(d.pm, &pi, d.this.id, full_name);
+      standard_palette_init(&d.this);
+#     if 0
+         /* Logging (debugging only) */
+         {
+            char buffer[256];
+            (void)store_message(&d.pm->this, pp, buffer, sizeof buffer, 0,
+               "running test");
+            fprintf(stderr, "%s\n", buffer);
+         }
+#     endif
+      /* Introduce the correct read function. */
+      if (d.pm->this.progressive)
+      {
+         /* Share the row function with the standard implementation. */
+         png_set_progressive_read_fn(pp, &d, transform_info, progressive_row,
+            transform_end);
+         /* Now feed data into the reader until we reach the end: */
+         modifier_progressive_read(d.pm, pp, pi);
+      }
+      else
+      {
+         /* modifier_read expects a png_modifier* */
+         png_set_read_fn(pp, d.pm, modifier_read);
+         /* Check the header values: */
+         png_read_info(pp, pi);
+         /* Process the 'info' requirements. Only one image is generated */
+         transform_info_imp(&d, pp, pi);
+         sequential_row(&d.this, pp, pi, -1, 0);
+         if (!d.this.speed)
+            transform_image_validate(&d, pp, pi);
+         else
+            d.this.ps->validated = 1;
+      }
+      modifier_reset(d.pm);
+   }
+   Catch(fault)
+   {
+      modifier_reset((png_modifier*)fault);
+   }
+}
+/* The transforms: */
+#define ITSTRUCT(name) image_transform_##name
+#define ITDATA(name) image_transform_data_##name
+#define image_transform_ini image_transform_default_ini
+#define IT(name)\
+static image_transform ITSTRUCT(name) =\
+{\
+   #name,\
+   1, /*enable*/\
+   &PT, /*list*/\
+   0, /*global_use*/\
+   0, /*local_use*/\
+   0, /*next*/\
+   image_transform_ini,\
+   image_transform_png_set_##name##_set,\
+   image_transform_png_set_##name##_mod,\
+   image_transform_png_set_##name##_add\
+}
+#define PT ITSTRUCT(end) /* stores the previous transform */
+/* To save code: */
+static void
+image_transform_default_ini(PNG_CONST image_transform *this,
+    transform_display *that)
+{
+   this->next->ini(this->next, that);
+}
+static int
+image_transform_default_add(image_transform *this,
+    PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth)
+{
+   UNUSED(colour_type)
+   UNUSED(bit_depth)
+   this->next = *that;
+   *that = this;
+   return 1;
+}
+#ifdef PNG_READ_EXPAND_SUPPORTED
+/* png_set_palette_to_rgb */
+static void
+image_transform_png_set_palette_to_rgb_set(PNG_CONST image_transform *this,
+    transform_display *that, png_structp pp, png_infop pi)
+{
+   png_set_palette_to_rgb(pp);
+   this->next->set(this->next, that, pp, pi);
+}
+static void
+image_transform_png_set_palette_to_rgb_mod(PNG_CONST image_transform *this,
+    image_pixel *that, png_structp pp, PNG_CONST transform_display *display)
+{
+   if (that->colour_type == PNG_COLOR_TYPE_PALETTE)
+      image_pixel_convert_PLTE(that);
+   this->next->mod(this->next, that, pp, display);
+}
+static int
+image_transform_png_set_palette_to_rgb_add(image_transform *this,
+    PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth)
+{
+   UNUSED(bit_depth)
+   this->next = *that;
+   *that = this;
+   return colour_type == PNG_COLOR_TYPE_PALETTE;
+}
+IT(palette_to_rgb);
+#undef PT
+#define PT ITSTRUCT(palette_to_rgb)
+#endif /* PNG_READ_EXPAND_SUPPORTED */
+#ifdef PNG_READ_EXPAND_SUPPORTED
+/* png_set_tRNS_to_alpha */
+static void
+image_transform_png_set_tRNS_to_alpha_set(PNG_CONST image_transform *this,
+   transform_display *that, png_structp pp, png_infop pi)
+{
+   png_set_tRNS_to_alpha(pp);
+   this->next->set(this->next, that, pp, pi);
+}
+static void
+image_transform_png_set_tRNS_to_alpha_mod(PNG_CONST image_transform *this,
+   image_pixel *that, png_structp pp, PNG_CONST transform_display *display)
+{
+   /* LIBPNG BUG: this always forces palette images to RGB. */
+   if (that->colour_type == PNG_COLOR_TYPE_PALETTE)
+      image_pixel_convert_PLTE(that);
+   /* This effectively does an 'expand' only if there is some transparency to
+    * convert to an alpha channel.
+    */
+   if (that->have_tRNS)
+      image_pixel_add_alpha(that, &display->this);
+   /* LIBPNG BUG: otherwise libpng still expands to 8 bits! */
+   else
+   {
+      if (that->bit_depth < 8)
+         that->bit_depth =8;
+      if (that->sample_depth < 8)
+         that->sample_depth = 8;
+   }
+   this->next->mod(this->next, that, pp, display);
+}
+static int
+image_transform_png_set_tRNS_to_alpha_add(image_transform *this,
+    PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth)
+{
+   UNUSED(bit_depth)
+   this->next = *that;
+   *that = this;
+   /* We don't know yet whether there will be a tRNS chunk, but we know that
+    * this transformation should do nothing if there already is an alpha
+    * channel.
+    */
+   return (colour_type & PNG_COLOR_MASK_ALPHA) == 0;
+}
+IT(tRNS_to_alpha);
+#undef PT
+#define PT ITSTRUCT(tRNS_to_alpha)
+#endif /* PNG_READ_EXPAND_SUPPORTED */
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+/* png_set_gray_to_rgb */
+static void
+image_transform_png_set_gray_to_rgb_set(PNG_CONST image_transform *this,
+    transform_display *that, png_structp pp, png_infop pi)
+{
+   png_set_gray_to_rgb(pp);
+   this->next->set(this->next, that, pp, pi);
+}
+static void
+image_transform_png_set_gray_to_rgb_mod(PNG_CONST image_transform *this,
+    image_pixel *that, png_structp pp, PNG_CONST transform_display *display)
+{
+   /* NOTE: we can actually pend the tRNS processing at this point because we
+    * can correctly recognize the original pixel value even though we have
+    * mapped the one gray channel to the three RGB ones, but in fact libpng
+    * doesn't do this, so we don't either.
+    */
+   if ((that->colour_type & PNG_COLOR_MASK_COLOR) == 0 && that->have_tRNS)
+      image_pixel_add_alpha(that, &display->this);
+   /* Simply expand the bit depth and alter the colour type as required. */
+   if (that->colour_type == PNG_COLOR_TYPE_GRAY)
+   {
+      /* RGB images have a bit depth at least equal to '8' */
+      if (that->bit_depth < 8)
+         that->sample_depth = that->bit_depth = 8;
+      /* And just changing the colour type works here because the green and blue
+       * channels are being maintained in lock-step with the red/gray:
+       */
+      that->colour_type = PNG_COLOR_TYPE_RGB;
+   }
+   else if (that->colour_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+      that->colour_type = PNG_COLOR_TYPE_RGB_ALPHA;
+   this->next->mod(this->next, that, pp, display);
+}
+static int
+image_transform_png_set_gray_to_rgb_add(image_transform *this,
+    PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth)
+{
+   UNUSED(bit_depth)
+   this->next = *that;
+   *that = this;
+   return (colour_type & PNG_COLOR_MASK_COLOR) == 0;
+}
+IT(gray_to_rgb);
+#undef PT
+#define PT ITSTRUCT(gray_to_rgb)
+#endif /* PNG_READ_GRAY_TO_RGB_SUPPORTED */
+#ifdef PNG_READ_EXPAND_SUPPORTED
+/* png_set_expand */
+static void
+image_transform_png_set_expand_set(PNG_CONST image_transform *this,
+    transform_display *that, png_structp pp, png_infop pi)
+{
+   png_set_expand(pp);
+   this->next->set(this->next, that, pp, pi);
+}
+static void
+image_transform_png_set_expand_mod(PNG_CONST image_transform *this,
+    image_pixel *that, png_structp pp, PNG_CONST transform_display *display)
+{
+   /* The general expand case depends on what the colour type is: */
+   if (that->colour_type == PNG_COLOR_TYPE_PALETTE)
+      image_pixel_convert_PLTE(that);
+   else if (that->bit_depth < 8) /* grayscale */
+      that->sample_depth = that->bit_depth = 8;
+   if (that->have_tRNS)
+      image_pixel_add_alpha(that, &display->this);
+   this->next->mod(this->next, that, pp, display);
+}
+static int
+image_transform_png_set_expand_add(image_transform *this,
+    PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth)
+{
+   UNUSED(bit_depth)
+   this->next = *that;
+   *that = this;
+   /* 'expand' should do nothing for RGBA or GA input - no tRNS and the bit
+    * depth is at least 8 already.
+    */
+   return (colour_type & PNG_COLOR_MASK_ALPHA) == 0;
+}
+IT(expand);
+#undef PT
+#define PT ITSTRUCT(expand)
+#endif /* PNG_READ_EXPAND_SUPPORTED */
+#ifdef PNG_READ_EXPAND_SUPPORTED
+/* png_set_expand_gray_1_2_4_to_8
+ * LIBPNG BUG: this just does an 'expand'
+ */
+static void
+image_transform_png_set_expand_gray_1_2_4_to_8_set(
+    PNG_CONST image_transform *this, transform_display *that, png_structp pp,
+    png_infop pi)
+{
+   png_set_expand_gray_1_2_4_to_8(pp);
+   this->next->set(this->next, that, pp, pi);
+}
+static void
+image_transform_png_set_expand_gray_1_2_4_to_8_mod(
+    PNG_CONST image_transform *this, image_pixel *that, png_structp pp,
+    PNG_CONST transform_display *display)
+{
+   image_transform_png_set_expand_mod(this, that, pp, display);
+}
+static int
+image_transform_png_set_expand_gray_1_2_4_to_8_add(image_transform *this,
+    PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth)
+{
+   return image_transform_png_set_expand_add(this, that, colour_type,
+      bit_depth);
+}
+IT(expand_gray_1_2_4_to_8);
+#undef PT
+#define PT ITSTRUCT(expand_gray_1_2_4_to_8)
+#endif /* PNG_READ_EXPAND_SUPPORTED */
+#ifdef PNG_READ_EXPAND_16_SUPPORTED
+/* png_set_expand_16 */
+static void
+image_transform_png_set_expand_16_set(PNG_CONST image_transform *this,
+    transform_display *that, png_structp pp, png_infop pi)
+{
+   png_set_expand_16(pp);
+   this->next->set(this->next, that, pp, pi);
+}
+static void
+image_transform_png_set_expand_16_mod(PNG_CONST image_transform *this,
+    image_pixel *that, png_structp pp, PNG_CONST transform_display *display)
+{
+   /* Expect expand_16 to expand everything to 16 bits as a result of also
+    * causing 'expand' to happen.
+    */
+   if (that->colour_type == PNG_COLOR_TYPE_PALETTE)
+      image_pixel_convert_PLTE(that);
+   if (that->have_tRNS)
+      image_pixel_add_alpha(that, &display->this);
+   if (that->bit_depth < 16)
+      that->sample_depth = that->bit_depth = 16;
+   this->next->mod(this->next, that, pp, display);
+}
+static int
+image_transform_png_set_expand_16_add(image_transform *this,
+    PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth)
+{
+   UNUSED(colour_type)
+   this->next = *that;
+   *that = this;
+   /* expand_16 does something unless the bit depth is already 16. */
+   return bit_depth < 16;
+}
+IT(expand_16);
+#undef PT
+#define PT ITSTRUCT(expand_16)
+#endif /* PNG_READ_EXPAND_16_SUPPORTED */
+#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED  /* API added in 1.5.4 */
+/* png_set_scale_16 */
+static void
+image_transform_png_set_scale_16_set(PNG_CONST image_transform *this,
+    transform_display *that, png_structp pp, png_infop pi)
+{
+   png_set_scale_16(pp);
+   this->next->set(this->next, that, pp, pi);
+}
+static void
+image_transform_png_set_scale_16_mod(PNG_CONST image_transform *this,
+    image_pixel *that, png_structp pp, PNG_CONST transform_display *display)
+{
+   if (that->bit_depth == 16)
+   {
+      that->sample_depth = that->bit_depth = 8;
+      if (that->red_sBIT > 8) that->red_sBIT = 8;
+      if (that->green_sBIT > 8) that->green_sBIT = 8;
+      if (that->blue_sBIT > 8) that->blue_sBIT = 8;
+      if (that->alpha_sBIT > 8) that->alpha_sBIT = 8;
+   }
+   this->next->mod(this->next, that, pp, display);
+}
+static int
+image_transform_png_set_scale_16_add(image_transform *this,
+    PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth)
+{
+   UNUSED(colour_type)
+   this->next = *that;
+   *that = this;
+   return bit_depth > 8;
+}
+IT(scale_16);
+#undef PT
+#define PT ITSTRUCT(scale_16)
+#endif /* PNG_READ_SCALE_16_TO_8_SUPPORTED (1.5.4 on) */
+#ifdef PNG_READ_16_TO_8_SUPPORTED /* the default before 1.5.4 */
+/* png_set_strip_16 */
+static void
+image_transform_png_set_strip_16_set(PNG_CONST image_transform *this,
+    transform_display *that, png_structp pp, png_infop pi)
+{
+   png_set_strip_16(pp);
+   this->next->set(this->next, that, pp, pi);
+}
+static void
+image_transform_png_set_strip_16_mod(PNG_CONST image_transform *this,
+    image_pixel *that, png_structp pp, PNG_CONST transform_display *display)
+{
+   if (that->bit_depth == 16)
+   {
+      that->sample_depth = that->bit_depth = 8;
+      if (that->red_sBIT > 8) that->red_sBIT = 8;
+      if (that->green_sBIT > 8) that->green_sBIT = 8;
+      if (that->blue_sBIT > 8) that->blue_sBIT = 8;
+      if (that->alpha_sBIT > 8) that->alpha_sBIT = 8;
+      /* Prior to 1.5.4 png_set_strip_16 would use an 'accurate' method if this
+       * configuration option is set.  From 1.5.4 the flag is never set and the
+       * 'scale' API (above) must be used.
+       */
+#     ifdef PNG_READ_ACCURATE_SCALE_SUPPORTED
+#        if PNG_LIBPNG_VER >= 10504
+#           error PNG_READ_ACCURATE_SCALE should not be set
+#        endif
+         /* The strip 16 algorithm drops the low 8 bits rather than calculating
+          * 1/257, so we need to adjust the permitted errors appropriately:
+          * Notice that this is only relevant prior to the addition of the
+          * png_set_scale_16 API in 1.5.4 (but 1.5.4+ always defines the above!)
+          */
+         {
+            PNG_CONST double d = (255-128.5)/65535;
+            that->rede += d;
+            that->greene += d;
+            that->bluee += d;
+            that->alphae += d;
+         }
+#     endif
+   }
+   this->next->mod(this->next, that, pp, display);
+}
+static int
+image_transform_png_set_strip_16_add(image_transform *this,
+    PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth)
+{
+   UNUSED(colour_type)
+   this->next = *that;
+   *that = this;
+   return bit_depth > 8;
+}
+IT(strip_16);
+#undef PT
+#define PT ITSTRUCT(strip_16)
+#endif /* PNG_READ_16_TO_8_SUPPORTED */
+#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
+/* png_set_strip_alpha */
+static void
+image_transform_png_set_strip_alpha_set(PNG_CONST image_transform *this,
+    transform_display *that, png_structp pp, png_infop pi)
+{
+   png_set_strip_alpha(pp);
+   this->next->set(this->next, that, pp, pi);
+}
+static void
+image_transform_png_set_strip_alpha_mod(PNG_CONST image_transform *this,
+    image_pixel *that, png_structp pp, PNG_CONST transform_display *display)
+{
+   if (that->colour_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+      that->colour_type = PNG_COLOR_TYPE_GRAY;
+   else if (that->colour_type == PNG_COLOR_TYPE_RGB_ALPHA)
+      that->colour_type = PNG_COLOR_TYPE_RGB;
+   that->have_tRNS = 0;
+   that->alphaf = 1;
+   this->next->mod(this->next, that, pp, display);
+}
+static int
+image_transform_png_set_strip_alpha_add(image_transform *this,
+    PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth)
+{
+   UNUSED(bit_depth)
+   this->next = *that;
+   *that = this;
+   return (colour_type & PNG_COLOR_MASK_ALPHA) != 0;
+}
+IT(strip_alpha);
+#undef PT
+#define PT ITSTRUCT(strip_alpha)
+#endif /* PNG_READ_STRIP_ALPHA_SUPPORTED */
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+/* png_set_rgb_to_gray(png_structp, int err_action, double red, double green)
+ * png_set_rgb_to_gray_fixed(png_structp, int err_action, png_fixed_point red,
+ *    png_fixed_point green)
+ * png_get_rgb_to_gray_status
+ *
+ * The 'default' test here uses values known to be used inside libpng:
+ *
+ *   red:    6968
+ *   green: 23434
+ *   blue:   2366
+ *
+ * These values are being retained for compatibility, along with the somewhat
+ * broken truncation calculation in the fast-and-inaccurate code path.  Older
+ * versions of libpng will fail the accuracy tests below because they use the
+ * truncation algorithm everywhere.
+ */
+#define data ITDATA(rgb_to_gray)
+static struct
+{
+   double gamma;      /* File gamma to use in processing */
+   /* The following are the parameters for png_set_rgb_to_gray: */
+#  ifdef PNG_FLOATING_POINT_SUPPORTED
+      double red_to_set;
+      double green_to_set;
+#  else
+      png_fixed_point red_to_set;
+      png_fixed_point green_to_set;
+#  endif
+   /* The actual coefficients: */
+   double red_coefficient;
+   double green_coefficient;
+   double blue_coefficient;
+   /* Set if the coeefficients have been overridden. */
+   int coefficients_overridden;
+} data;
+#undef image_transform_ini
+#define image_transform_ini image_transform_png_set_rgb_to_gray_ini
+static void
+image_transform_png_set_rgb_to_gray_ini(PNG_CONST image_transform *this,
+    transform_display *that)
+{
+   png_modifier *pm = that->pm;
+   PNG_CONST color_encoding *e = pm->current_encoding;
+   UNUSED(this)
+   /* Since we check the encoding this flag must be set: */
+   pm->test_uses_encoding = 1;
+   /* If 'e' is not NULL chromaticity information is present and either a cHRM
+    * or an sRGB chunk will be inserted.
+    */
+   if (e != 0)
+   {
+      /* Coefficients come from the encoding, but may need to be normalized to a
+       * white point Y of 1.0
+       */
+      PNG_CONST double whiteY = e->red.Y + e->green.Y + e->blue.Y;
+      data.red_coefficient = e->red.Y;
+      data.green_coefficient = e->green.Y;
+      data.blue_coefficient = e->blue.Y;
+      if (whiteY != 1)
+      {
+         data.red_coefficient /= whiteY;
+         data.green_coefficient /= whiteY;
+         data.blue_coefficient /= whiteY;
+      }
+   }
+   else
+   {
+      /* The default (built in) coeffcients, as above: */
+      data.red_coefficient = 6968 / 32768.;
+      data.green_coefficient = 23434 / 32768.;
+      data.blue_coefficient = 2366 / 32768.;
+   }
+   data.gamma = pm->current_gamma;
+   /* If not set then the calculations assume linear encoding (implicitly): */
+   if (data.gamma == 0)
+      data.gamma = 1;
+   /* The arguments to png_set_rgb_to_gray can override the coefficients implied
+    * by the color space encoding.  If doing exhaustive checks do the override
+    * in each case, otherwise do it randomly.
+    */
+   if (pm->test_exhaustive)
+   {
+      /* First time in coefficients_overridden is 0, the following sets it to 1,
+       * so repeat if it is set.  If a test fails this may mean we subsequently
+       * skip a non-override test, ignore that.
+       */
+      data.coefficients_overridden = !data.coefficients_overridden;
+      pm->repeat = data.coefficients_overridden != 0;
+   }
+   else
+      data.coefficients_overridden = random_choice();
+   if (data.coefficients_overridden)
+   {
+      /* These values override the color encoding defaults, simply use random
+       * numbers.
+       */
+      png_uint_32 ru;
+      double total;
+      RANDOMIZE(ru);
+      data.green_coefficient = total = (ru & 0xffff) / 65535.;
+      ru >>= 16;
+      data.red_coefficient = (1 - total) * (ru & 0xffff) / 65535.;
+      total += data.red_coefficient;
+      data.blue_coefficient = 1 - total;
+#     ifdef PNG_FLOATING_POINT_SUPPORTED
+         data.red_to_set = data.red_coefficient;
+         data.green_to_set = data.green_coefficient;
+#     else
+         data.red_to_set = fix(data.red_coefficient);
+         data.green_to_set = fix(data.green_coefficient);
+#     endif
+      /* The following just changes the error messages: */
+      pm->encoding_ignored = 1;
+   }
+   else
+   {
+      data.red_to_set = -1;
+      data.green_to_set = -1;
+   }
+   /* Adjust the error limit in the png_modifier because of the larger errors
+    * produced in the digitization during the gamma handling.
+    */
+   if (data.gamma != 1) /* Use gamma tables */
+   {
+      if (that->this.bit_depth == 16 || pm->assume_16_bit_calculations)
+      {
+         /* The 16 bit case ends up producing a maximum error of about
+          * +/-5 in 65535, allow for +/-8 with the given gamma.
+          */
+         that->pm->limit += pow(8./65535, data.gamma);
+      }
+      else
+      {
+         /* Rounding to 8 bits in the linear space causes massive errors which
+          * will trigger the error check in transform_range_check.  Fix that
+          * here by taking the gamma encoding into account.
+          */
+         that->pm->limit += pow(1./255, data.gamma);
+      }
+   }
+   else
+   {
+      /* With no gamma correction a large error comes from the truncation of the
+       * calculation in the 8 bit case, allow for that here.
+       */
+      if (that->this.bit_depth != 16)
+         that->pm->limit += 4E-3;
+   }
+}
+static void
+image_transform_png_set_rgb_to_gray_set(PNG_CONST image_transform *this,
+    transform_display *that, png_structp pp, png_infop pi)
+{
+   PNG_CONST int error_action = 1; /* no error, no defines in png.h */
+#  ifdef PNG_FLOATING_POINT_SUPPORTED
+      png_set_rgb_to_gray(pp, error_action, data.red_to_set, data.green_to_set);
+#  else
+      png_set_rgb_to_gray_fixed(pp, error_action, data.red_to_set,
+         data.green_to_set);
+#  endif
+#  ifdef PNG_READ_cHRM_SUPPORTED
+      if (that->pm->current_encoding != 0)
+      {
+         /* We have an encoding so a cHRM chunk may have been set; if so then
+          * check that the libpng APIs give the correct (X,Y,Z) values within
+          * some margin of error for the round trip through the chromaticity
+          * form.
+          */
+#        ifdef PNG_FLOATING_POINT_SUPPORTED
+#           define API_function png_get_cHRM_XYZ
+#           define API_form "FP"
+#           define API_type double
+#           define API_cvt(x) (x)
+#        else
+#           define API_function png_get_cHRM_XYZ_fixed
+#           define API_form "fixed"
+#           define API_type png_fixed_point
+#           define API_cvt(x) ((double)(x)/PNG_FP_1)
+#        endif
+         API_type rX, gX, bX;
+         API_type rY, gY, bY;
+         API_type rZ, gZ, bZ;
+         if ((API_function(pp, pi, &rX, &rY, &rZ, &gX, &gY, &gZ, &bX, &bY, &bZ)
+               & PNG_INFO_cHRM) != 0)
+         {
+            double maxe;
+            PNG_CONST char *el;
+            color_encoding e, o;
+            /* Expect libpng to return a normalized result, but the original
+             * color space encoding may not be normalized.
+             */
+            modifier_current_encoding(that->pm, &o);
+            normalize_color_encoding(&o);
+            /* Sanity check the pngvalid code - the coefficients should match
+             * the normalized Y values of the encoding unless they were
+             * overridden.
+             */
+            if (data.red_to_set == -1 && data.green_to_set == -1 &&
+               (fabs(o.red.Y - data.red_coefficient) > DBL_EPSILON ||
+               fabs(o.green.Y - data.green_coefficient) > DBL_EPSILON ||
+               fabs(o.blue.Y - data.blue_coefficient) > DBL_EPSILON))
+               png_error(pp, "internal pngvalid cHRM coefficient error");
+            /* Generate a colour space encoding. */
+            e.gamma = o.gamma; /* not used */
+            e.red.X = API_cvt(rX);
+            e.red.Y = API_cvt(rY);
+            e.red.Z = API_cvt(rZ);
+            e.green.X = API_cvt(gX);
+            e.green.Y = API_cvt(gY);
+            e.green.Z = API_cvt(gZ);
+            e.blue.X = API_cvt(bX);
+            e.blue.Y = API_cvt(bY);
+            e.blue.Z = API_cvt(bZ);
+            /* This should match the original one from the png_modifier, within
+             * the range permitted by the libpng fixed point representation.
+             */
+            maxe = 0;
+            el = "-"; /* Set to element name with error */
+#           define CHECK(col,x)\
+            {\
+               double err = fabs(o.col.x - e.col.x);\
+               if (err > maxe)\
+               {\
+                  maxe = err;\
+                  el = #col "(" #x ")";\
+               }\
+            }
+            CHECK(red,X)
+            CHECK(red,Y)
+            CHECK(red,Z)
+            CHECK(green,X)
+            CHECK(green,Y)
+            CHECK(green,Z)
+            CHECK(blue,X)
+            CHECK(blue,Y)
+            CHECK(blue,Z)
+            /* Here in both fixed and floating cases to check the values read
+             * from the cHRm chunk.  PNG uses fixed point in the cHRM chunk, so
+             * we can't expect better than +/-.5E-5 on the result, allow 1E-5.
+             */
+            if (maxe >= 1E-5)
+            {
+               size_t pos = 0;
+               char buffer[256];
+               pos = safecat(buffer, sizeof buffer, pos, API_form);
+               pos = safecat(buffer, sizeof buffer, pos, " cHRM ");
+               pos = safecat(buffer, sizeof buffer, pos, el);
+               pos = safecat(buffer, sizeof buffer, pos, " error: ");
+               pos = safecatd(buffer, sizeof buffer, pos, maxe, 7);
+               pos = safecat(buffer, sizeof buffer, pos, " ");
+               /* Print the color space without the gamma value: */
+               pos = safecat_color_encoding(buffer, sizeof buffer, pos, &o, 0);
+               pos = safecat(buffer, sizeof buffer, pos, " -> ");
+               pos = safecat_color_encoding(buffer, sizeof buffer, pos, &e, 0);
+               png_error(pp, buffer);
+            }
+         }
+      }
+#  endif /* READ_cHRM */
+   this->next->set(this->next, that, pp, pi);
+}
+static void
+image_transform_png_set_rgb_to_gray_mod(PNG_CONST image_transform *this,
+    image_pixel *that, png_structp pp, PNG_CONST transform_display *display)
+{
+   if ((that->colour_type & PNG_COLOR_MASK_COLOR) != 0)
+   {
+      double gray, err;
+      if (that->colour_type == PNG_COLOR_TYPE_PALETTE)
+         image_pixel_convert_PLTE(that);
+      /* Image now has RGB channels... */
+      {
+         PNG_CONST png_modifier *pm = display->pm;
+         PNG_CONST unsigned int sample_depth = that->sample_depth;
+         int isgray;
+         double r, g, b;
+         double rlo, rhi, glo, ghi, blo, bhi, graylo, grayhi;
+         /* Do this using interval arithmetic, otherwise it is too difficult to
+          * handle the errors correctly.
+          *
+          * To handle the gamma correction work out the upper and lower bounds
+          * of the digitized value.  Assume rounding here - normally the values
+          * will be identical after this operation if there is only one
+          * transform, feel free to delete the png_error checks on this below in
+          * the future (this is just me trying to ensure it works!)
+          */
+         r = rlo = rhi = that->redf;
+         rlo -= that->rede;
+         rlo = digitize(pm, rlo, sample_depth, 1/*round*/);
+         rhi += that->rede;
+         rhi = digitize(pm, rhi, sample_depth, 1/*round*/);
+         g = glo = ghi = that->greenf;
+         glo -= that->greene;
+         glo = digitize(pm, glo, sample_depth, 1/*round*/);
+         ghi += that->greene;
+         ghi = digitize(pm, ghi, sample_depth, 1/*round*/);
+         b = blo = bhi = that->bluef;
+         blo -= that->bluee;
+         blo = digitize(pm, blo, sample_depth, 1/*round*/);
+         bhi += that->greene;
+         bhi = digitize(pm, bhi, sample_depth, 1/*round*/);
+         isgray = r==g && g==b;
+         if (data.gamma != 1)
+         {
+            PNG_CONST double power = 1/data.gamma;
+            PNG_CONST double abse = abserr(pm, sample_depth, sample_depth);
+            /* 'abse' is the absolute error permitted in linear calculations. It
+             * is used here to capture the error permitted in the handling
+             * (undoing) of the gamma encoding.  Once again digitization occurs
+             * to handle the upper and lower bounds of the values.  This is
+             * where the real errors are introduced.
+             */
+            r = pow(r, power);
+            rlo = digitize(pm, pow(rlo, power)-abse, sample_depth, 1);
+            rhi = digitize(pm, pow(rhi, power)+abse, sample_depth, 1);
+            g = pow(g, power);
+            glo = digitize(pm, pow(glo, power)-abse, sample_depth, 1);
+            ghi = digitize(pm, pow(ghi, power)+abse, sample_depth, 1);
+            b = pow(b, power);
+            blo = digitize(pm, pow(blo, power)-abse, sample_depth, 1);
+            bhi = digitize(pm, pow(bhi, power)+abse, sample_depth, 1);
+         }
+         /* Now calculate the actual gray values.  Although the error in the
+          * coefficients depends on whether they were specified on the command
+          * line (in which case truncation to 15 bits happened) or not (rounding
+          * was used) the maxium error in an individual coefficient is always
+          * 1/32768, because even in the rounding case the requirement that
+          * coefficients add up to 32768 can cause a larger rounding error.
+          *
+          * The only time when rounding doesn't occur in 1.5.5 and later is when
+          * the non-gamma code path is used for less than 16 bit data.
+          */
+         gray = r * data.red_coefficient + g * data.green_coefficient +
+            b * data.blue_coefficient;
+         {
+            PNG_CONST int do_round = data.gamma != 1 || sample_depth == 16;
+            PNG_CONST double ce = 1. / 32768;
+            graylo = digitize(pm, rlo * (data.red_coefficient-ce) +
+               glo * (data.green_coefficient-ce) +
+               blo * (data.blue_coefficient-ce), sample_depth, do_round);
+            if (graylo <= 0)
+               graylo = 0;
+            grayhi = digitize(pm, rhi * (data.red_coefficient+ce) +
+               ghi * (data.green_coefficient+ce) +
+               bhi * (data.blue_coefficient+ce), sample_depth, do_round);
+            if (grayhi >= 1)
+               grayhi = 1;
+         }
+         /* And invert the gamma. */
+         if (data.gamma != 1)
+         {
+            PNG_CONST double power = data.gamma;
+            gray = pow(gray, power);
+            graylo = digitize(pm, pow(graylo, power), sample_depth, 1);
+            grayhi = digitize(pm, pow(grayhi, power), sample_depth, 1);
+         }
+         /* Now the error can be calculated.
+          *
+          * If r==g==b because there is no overall gamma correction libpng
+          * currently preserves the original value.
+          */
+         if (isgray)
+            err = (that->rede + that->greene + that->bluee)/3;
+         else
+         {
+            err = fabs(grayhi-gray);
+            if (fabs(gray - graylo) > err)
+               err = fabs(graylo-gray);
+            /* Check that this worked: */
+            if (err > display->pm->limit)
+            {
+               size_t pos = 0;
+               char buffer[128];
+               pos = safecat(buffer, sizeof buffer, pos, "rgb_to_gray error ");
+               pos = safecatd(buffer, sizeof buffer, pos, err, 6);
+               pos = safecat(buffer, sizeof buffer, pos, " exceeds limit ");
+               pos = safecatd(buffer, sizeof buffer, pos,
+                  display->pm->limit, 6);
+               png_error(pp, buffer);
+            }
+         }
+      }
+      that->bluef = that->greenf = that->redf = gray;
+      that->bluee = that->greene = that->rede = err;
+      /* The sBIT is the minium of the three colour channel sBITs. */
+      if (that->red_sBIT > that->green_sBIT)
+         that->red_sBIT = that->green_sBIT;
+      if (that->red_sBIT > that->blue_sBIT)
+         that->red_sBIT = that->blue_sBIT;
+      that->blue_sBIT = that->green_sBIT = that->red_sBIT;
+      /* And remove the colour bit in the type: */
+      if (that->colour_type == PNG_COLOR_TYPE_RGB)
+         that->colour_type = PNG_COLOR_TYPE_GRAY;
+      else if (that->colour_type == PNG_COLOR_TYPE_RGB_ALPHA)
+         that->colour_type = PNG_COLOR_TYPE_GRAY_ALPHA;
+   }
+   this->next->mod(this->next, that, pp, display);
+}
+static int
+image_transform_png_set_rgb_to_gray_add(image_transform *this,
+    PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth)
+{
+   UNUSED(bit_depth)
+   this->next = *that;
+   *that = this;
+   return (colour_type & PNG_COLOR_MASK_COLOR) != 0;
+}
+#undef data
+IT(rgb_to_gray);
+#undef PT
+#define PT ITSTRUCT(rgb_to_gray)
+#undef image_transform_ini
+#define image_transform_ini image_transform_default_ini
+#endif /* PNG_READ_RGB_TO_GRAY_SUPPORTED */
+#ifdef PNG_READ_BACKGROUND_SUPPORTED
+/* png_set_background(png_structp, png_const_color_16p background_color,
+ *    int background_gamma_code, int need_expand, double background_gamma)
+ * png_set_background_fixed(png_structp, png_const_color_16p background_color,
+ *    int background_gamma_code, int need_expand,
+ *    png_fixed_point background_gamma)
+ *
+ * As with rgb_to_gray this ignores the gamma (at present.)
+*/
+#define data ITDATA(background)
+static image_pixel data;
+static void
+image_transform_png_set_background_set(PNG_CONST image_transform *this,
+    transform_display *that, png_structp pp, png_infop pi)
+{
+   png_byte colour_type, bit_depth;
+   png_byte random_bytes[8]; /* 8 bytes - 64 bits - the biggest pixel */
+   png_color_16 back;
+   /* We need a background colour, because we don't know exactly what transforms
+    * have been set we have to supply the colour in the original file format and
+    * so we need to know what that is!  The background colour is stored in the
+    * transform_display.
+    */
+   RANDOMIZE(random_bytes);
+   /* Read the random value, for colour type 3 the background colour is actually
+    * expressed as a 24bit rgb, not an index.
+    */
+   colour_type = that->this.colour_type;
+   if (colour_type == 3)
+   {
+      colour_type = PNG_COLOR_TYPE_RGB;
+      bit_depth = 8;
+   }
+   else
+      bit_depth = that->this.bit_depth;
+   image_pixel_init(&data, random_bytes, colour_type,
+      bit_depth, 0/*x*/, 0/*unused: palette*/);
+   /* Extract the background colour from this image_pixel, but make sure the
+    * unused fields of 'back' are garbage.
+    */
+   RANDOMIZE(back);
+   if (colour_type & PNG_COLOR_MASK_COLOR)
+   {
+      back.red = (png_uint_16)data.red;
+      back.green = (png_uint_16)data.green;
+      back.blue = (png_uint_16)data.blue;
+   }
+   else
+      back.gray = (png_uint_16)data.red;
+#  ifdef PNG_FLOATING_POINT_SUPPORTED
+      png_set_background(pp, &back, PNG_BACKGROUND_GAMMA_FILE, 1/*need expand*/,
+         0);
+#  else
+      png_set_background_fixed(pp, &back, PNG_BACKGROUND_GAMMA_FILE,
+         1/*need expand*/, 0);
+#  endif
+   this->next->set(this->next, that, pp, pi);
+}
+static void
+image_transform_png_set_background_mod(PNG_CONST image_transform *this,
+    image_pixel *that, png_structp pp, PNG_CONST transform_display *display)
+{
+   /* Check for tRNS first: */
+   if (that->have_tRNS && that->colour_type != PNG_COLOR_TYPE_PALETTE)
+      image_pixel_add_alpha(that, &display->this);
+   /* This is only necessary if the alpha value is less than 1. */
+   if (that->alphaf < 1)
+   {
+      /* Now we do the background calculation without any gamma correction. */
+      if (that->alphaf <= 0)
+      {
+         that->redf = data.redf;
+         that->greenf = data.greenf;
+         that->bluef = data.bluef;
+         that->rede = data.rede;
+         that->greene = data.greene;
+         that->bluee = data.bluee;
+         that->red_sBIT= data.red_sBIT;
+         that->green_sBIT= data.green_sBIT;
+         that->blue_sBIT= data.blue_sBIT;
+      }
+      else /* 0 < alpha < 1 */
+      {
+         double alf = 1 - that->alphaf;
+         that->redf = that->redf * that->alphaf + data.redf * alf;
+         that->rede = that->rede * that->alphaf + data.rede * alf +
+            DBL_EPSILON;
+         that->greenf = that->greenf * that->alphaf + data.greenf * alf;
+         that->greene = that->greene * that->alphaf + data.greene * alf +
+            DBL_EPSILON;
+         that->bluef = that->bluef * that->alphaf + data.bluef * alf;
+         that->bluee = that->bluee * that->alphaf + data.bluee * alf +
+            DBL_EPSILON;
+      }
+      /* Remove the alpha type and set the alpha (not in that order.) */
+      that->alphaf = 1;
+      that->alphae = 0;
+      if (that->colour_type == PNG_COLOR_TYPE_RGB_ALPHA)
+         that->colour_type = PNG_COLOR_TYPE_RGB;
+      else if (that->colour_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+         that->colour_type = PNG_COLOR_TYPE_GRAY;
+      /* PNG_COLOR_TYPE_PALETTE is not changed */
+   }
+   this->next->mod(this->next, that, pp, display);
+}
+#define image_transform_png_set_background_add image_transform_default_add
+#undef data
+IT(background);
+#undef PT
+#define PT ITSTRUCT(background)
+#endif /* PNG_READ_BACKGROUND_SUPPORTED */
+/* This may just be 'end' if all the transforms are disabled! */
+static image_transform *PNG_CONST image_transform_first = &PT;
+static void
+transform_enable(PNG_CONST char *name)
+{
+   /* Everything starts out enabled, so if we see an 'enable' disabled
+    * everything else the first time round.
+    */
+   static int all_disabled = 0;
+   int found_it = 0;
+   image_transform *list = image_transform_first;
+   while (list != &image_transform_end)
+   {
+      if (strcmp(list->name, name) == 0)
+      {
+         list->enable = 1;
+         found_it = 1;
+      }
+      else if (!all_disabled)
+         list->enable = 0;
+      list = list->list;
+   }
+   all_disabled = 1;
+   if (!found_it)
+   {
+      fprintf(stderr, "pngvalid: --transform-enable=%s: unknown transform\n",
+         name);
+      exit(1);
+   }
+}
+static void
+transform_disable(PNG_CONST char *name)
+{
+   image_transform *list = image_transform_first;
+   while (list != &image_transform_end)
+   {
+      if (strcmp(list->name, name) == 0)
+      {
+         list->enable = 0;
+         return;
+      }
+      list = list->list;
+   }
+   fprintf(stderr, "pngvalid: --transform-disable=%s: unknown transform\n",
+      name);
+   exit(1);
+}
+static void
+image_transform_reset_count(void)
+{
+   image_transform *next = image_transform_first;
+   int count = 0;
+   while (next != &image_transform_end)
+   {
+      next->local_use = 0;
+      next->next = 0;
+      next = next->list;
+      ++count;
+   }
+   /* This can only happen if we every have more than 32 transforms (excluding
+    * the end) in the list.
+    */
+   if (count > 32) abort();
+}
+static int
+image_transform_test_counter(png_uint_32 counter, unsigned int max)
+{
+   /* Test the list to see if there is any point contining, given a current
+    * counter and a 'max' value.
+    */
+   image_transform *next = image_transform_first;
+   while (next != &image_transform_end)
+   {
+      /* For max 0 or 1 continue until the counter overflows: */
+      counter >>= 1;
+      /* Continue if any entry hasn't reacked the max. */
+      if (max > 1 && next->local_use < max)
+         return 1;
+      next = next->list;
+   }
+   return max <= 1 && counter == 0;
+}
+static png_uint_32
+image_transform_add(PNG_CONST image_transform **this, unsigned int max,
+   png_uint_32 counter, char *name, size_t sizeof_name, size_t *pos,
+   png_byte colour_type, png_byte bit_depth)
+{
+   for (;;) /* until we manage to add something */
+   {
+      png_uint_32 mask;
+      image_transform *list;
+      /* Find the next counter value, if the counter is zero this is the start
+       * of the list.  This routine always returns the current counter (not the
+       * next) so it returns 0 at the end and expects 0 at the beginning.
+       */
+      if (counter == 0) /* first time */
+      {
+         image_transform_reset_count();
+         if (max <= 1)
+            counter = 1;
+         else
+            counter = random_32();
+      }
+      else /* advance the counter */
+      {
+         switch (max)
+         {
+            case 0:  ++counter; break;
+            case 1:  counter <<= 1; break;
+            default: counter = random_32(); break;
+         }
+      }
+      /* Now add all these items, if possible */
+      *this = &image_transform_end;
+      list = image_transform_first;
+      mask = 1;
+      /* Go through the whole list adding anything that the counter selects: */
+      while (list != &image_transform_end)
+      {
+         if ((counter & mask) != 0 && list->enable &&
+             (max == 0 || list->local_use < max))
+         {
+            /* Candidate to add: */
+            if (list->add(list, this, colour_type, bit_depth) || max == 0)
+            {
+               /* Added, so add to the name too. */
+               *pos = safecat(name, sizeof_name, *pos, " +");
+               *pos = safecat(name, sizeof_name, *pos, list->name);
+            }
+            else
+            {
+               /* Not useful and max>0, so remove it from *this: */
+               *this = list->next;
+               list->next = 0;
+               /* And, since we know it isn't useful, stop it being added again
+                * in this run:
+                */
+               list->local_use = max;
+            }
+         }
+         mask <<= 1;
+         list = list->list;
+      }
+      /* Now if anything was added we have something to do. */
+      if (*this != &image_transform_end)
+         return counter;
+      /* Nothing added, but was there anything in there to add? */
+      if (!image_transform_test_counter(counter, max))
+         return 0;
+   }
+}
+#ifdef THIS_IS_THE_PROFORMA
+static void
+image_transform_png_set_@_set(PNG_CONST image_transform *this,
+    transform_display *that, png_structp pp, png_infop pi)
+{
+   png_set_@(pp);
+   this->next->set(this->next, that, pp, pi);
+}
+static void
+image_transform_png_set_@_mod(PNG_CONST image_transform *this,
+    image_pixel *that, png_structp pp, PNG_CONST transform_display *display)
+{
+   this->next->mod(this->next, that, pp, display);
+}
+static int
+image_transform_png_set_@_add(image_transform *this,
+    PNG_CONST image_transform **that, char *name, size_t sizeof_name,
+    size_t *pos, png_byte colour_type, png_byte bit_depth)
+{
+   this->next = *that;
+   *that = this;
+   *pos = safecat(name, sizeof_name, *pos, " +@");
+   return 1;
+}
+IT(@);
+#endif
+/* png_set_quantize(png_structp, png_colorp palette, int num_palette,
+ *    int maximum_colors, png_const_uint_16p histogram, int full_quantize)
+ *
+ * Very difficult to validate this!
+ */
+/*NOTE: TBD NYI */
+/* The data layout transforms are handled by swapping our own channel data,
+ * necessarily these need to happen at the end of the transform list because the
+ * semantic of the channels changes after these are executed.  Some of these,
+ * like set_shift and set_packing, can't be done at present because they change
+ * the layout of the data at the sub-sample level so sample() won't get the
+ * right answer.
+ */
+/* png_set_invert_alpha */
+/*NOTE: TBD NYI */
+/* png_set_bgr */
+/*NOTE: TBD NYI */
+/* png_set_swap_alpha */
+/*NOTE: TBD NYI */
+/* png_set_swap */
+/*NOTE: TBD NYI */
+/* png_set_filler, (png_structp png_ptr, png_uint_32 filler, int flags)); */
+/*NOTE: TBD NYI */
+/* png_set_add_alpha, (png_structp png_ptr, png_uint_32 filler, int flags)); */
+/*NOTE: TBD NYI */
+/* png_set_packing */
+/*NOTE: TBD NYI */
+/* png_set_packswap */
+/*NOTE: TBD NYI */
+/* png_set_invert_mono */
+/*NOTE: TBD NYI */
+/* png_set_shift(png_structp, png_const_color_8p true_bits) */
+/*NOTE: TBD NYI */
+static void
+perform_transform_test(png_modifier *pm)
+{
+   png_byte colour_type = 0;
+   png_byte bit_depth = 0;
+   int palette_number = 0;
+   while (next_format(&colour_type, &bit_depth, &palette_number))
+   {
+      png_uint_32 counter = 0;
+      size_t base_pos;
+      char name[64];
+      base_pos = safecat(name, sizeof name, 0, "transform:");
+      for (;;)
+      {
+         size_t pos = base_pos;
+         PNG_CONST image_transform *list = 0;
+         /* 'max' is currently hardwired to '1'; this should be settable on the
+          * command line.
+          */
+         counter = image_transform_add(&list, 1/*max*/, counter,
+            name, sizeof name, &pos, colour_type, bit_depth);
+         if (counter == 0)
+            break;
+         /* The command line can change this to checking interlaced images. */
+         do
+         {
+            pm->repeat = 0;
+            transform_test(pm, FILEID(colour_type, bit_depth, palette_number,
+               pm->interlace_type, 0, 0, 0), list, name);
+            if (fail(pm))
+               return;
+         }
+         while (pm->repeat);
+      }
+   }
+}
+#endif /* PNG_READ_TRANSFORMS_SUPPORTED */
+/********************************* GAMMA TESTS ********************************/
+#ifdef PNG_READ_GAMMA_SUPPORTED
+/* Reader callbacks and implementations, where they differ from the standard
+ * ones.
+ */
+typedef struct gamma_display
+{
+   standard_display this;
+   /* Parameters */
+   png_modifier*    pm;
+   double           file_gamma;
+   double           screen_gamma;
+   double           background_gamma;
+   png_byte         sbit;
+   int              threshold_test;
+   int              use_input_precision;
+   int              scale16;
+   int              expand16;
+   int              do_background;
+   png_color_16     background_color;
+   /* Local variables */
+   double       maxerrout;
+   double       maxerrpc;
+   double       maxerrabs;
+} gamma_display;
+#define ALPHA_MODE_OFFSET 4
+static void
+gamma_display_init(gamma_display *dp, png_modifier *pm, png_uint_32 id,
+    double file_gamma, double screen_gamma, png_byte sbit, int threshold_test,
+    int use_input_precision, int scale16, int expand16,
+    int do_background, PNG_CONST png_color_16 *pointer_to_the_background_color,
+    double background_gamma)
+{
+   /* Standard fields */
+   standard_display_init(&dp->this, &pm->this, id, 0/*do_interlace*/,
+      pm->use_update_info);
+   /* Parameter fields */
+   dp->pm = pm;
+   dp->file_gamma = file_gamma;
+   dp->screen_gamma = screen_gamma;
+   dp->background_gamma = background_gamma;
+   dp->sbit = sbit;
+   dp->threshold_test = threshold_test;
+   dp->use_input_precision = use_input_precision;
+   dp->scale16 = scale16;
+   dp->expand16 = expand16;
+   dp->do_background = do_background;
+   if (do_background && pointer_to_the_background_color != 0)
+      dp->background_color = *pointer_to_the_background_color;
+   else
+      memset(&dp->background_color, 0, sizeof dp->background_color);
+   /* Local variable fields */
+   dp->maxerrout = dp->maxerrpc = dp->maxerrabs = 0;
+}
+static void
+gamma_info_imp(gamma_display *dp, png_structp pp, png_infop pi)
+{
+   /* Reuse the standard stuff as appropriate. */
+   standard_info_part1(&dp->this, pp, pi);
+   /* If requested strip 16 to 8 bits - this is handled automagically below
+    * because the output bit depth is read from the library.  Note that there
+    * are interactions with sBIT but, internally, libpng makes sbit at most
+    * PNG_MAX_GAMMA_8 when doing the following.
+    */
+   if (dp->scale16)
+#     ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+         png_set_scale_16(pp);
+#     else
+         /* The following works both in 1.5.4 and earlier versions: */
+#        ifdef PNG_READ_16_TO_8_SUPPORTED
+            png_set_strip_16(pp);
+#        else
+            png_error(pp, "scale16 (16 to 8 bit conversion) not supported");
+#        endif
+#     endif
+   if (dp->expand16)
+#     ifdef PNG_READ_EXPAND_16_SUPPORTED
+         png_set_expand_16(pp);
+#     else
+         png_error(pp, "expand16 (8 to 16 bit conversion) not supported");
+#     endif
+   if (dp->do_background >= ALPHA_MODE_OFFSET)
+   {
+#     ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+      {
+         /* This tests the alpha mode handling, if supported. */
+         int mode = dp->do_background - ALPHA_MODE_OFFSET;
+         /* The gamma value is the output gamma, and is in the standard,
+          * non-inverted, represenation.  It provides a default for the PNG file
+          * gamma, but since the file has a gAMA chunk this does not matter.
+          */
+         PNG_CONST double sg = dp->screen_gamma;
+#        ifndef PNG_FLOATING_POINT_SUPPORTED
+            PNG_CONST png_fixed_point g = fix(sg);
+#        endif
+#        ifdef PNG_FLOATING_POINT_SUPPORTED
+            png_set_alpha_mode(pp, mode, sg);
+#        else
+            png_set_alpha_mode_fixed(pp, mode, g);
+#        endif
+         /* However, for the standard Porter-Duff algorithm the output defaults
+          * to be linear, so if the test requires non-linear output it must be
+          * corrected here.
+          */
+         if (mode == PNG_ALPHA_STANDARD && sg != 1)
+         {
+#           ifdef PNG_FLOATING_POINT_SUPPORTED
+               png_set_gamma(pp, sg, dp->file_gamma);
+#           else
+               png_fixed_point f = fix(dp->file_gamma);
+               png_set_gamma_fixed(pp, g, f);
+#           endif
+         }
+      }
+#     else
+         png_error(pp, "alpha mode handling not supported");
+#     endif
+   }
+   else
+   {
+      /* Set up gamma processing. */
+#     ifdef PNG_FLOATING_POINT_SUPPORTED
+         png_set_gamma(pp, dp->screen_gamma, dp->file_gamma);
+#     else
+      {
+         png_fixed_point s = fix(dp->screen_gamma);
+         png_fixed_point f = fix(dp->file_gamma);
+         png_set_gamma_fixed(pp, s, f);
+      }
+#     endif
+      if (dp->do_background)
+      {
+#     ifdef PNG_READ_BACKGROUND_SUPPORTED
+         /* NOTE: this assumes the caller provided the correct background gamma!
+          */
+         PNG_CONST double bg = dp->background_gamma;
+#        ifndef PNG_FLOATING_POINT_SUPPORTED
+            PNG_CONST png_fixed_point g = fix(bg);
+#        endif
+#        ifdef PNG_FLOATING_POINT_SUPPORTED
+            png_set_background(pp, &dp->background_color, dp->do_background,
+               0/*need_expand*/, bg);
+#        else
+            png_set_background_fixed(pp, &dp->background_color,
+               dp->do_background, 0/*need_expand*/, g);
+#        endif
+#     else
+         png_error(pp, "png_set_background not supported");
+#     endif
+      }
+   }
+   {
+      int i = dp->this.use_update_info;
+      /* Always do one call, even if use_update_info is 0. */
+      do
+         png_read_update_info(pp, pi);
+      while (--i > 0);
+   }
+   /* Now we may get a different cbRow: */
+   standard_info_part2(&dp->this, pp, pi, 1 /*images*/);
+}
+static void
+gamma_info(png_structp pp, png_infop pi)
+{
+   gamma_info_imp(voidcast(gamma_display*, png_get_progressive_ptr(pp)), pp,
+      pi);
+}
+/* Validate a single component value - the routine gets the input and output
+ * sample values as unscaled PNG component values along with a cache of all the
+ * information required to validate the values.
+ */
+typedef struct validate_info
+{
+   png_structp  pp;
+   gamma_display *dp;
+   png_byte sbit;
+   int use_input_precision;
+   int do_background;
+   int scale16;
+   unsigned int sbit_max;
+   unsigned int isbit_shift;
+   unsigned int outmax;
+   double gamma_correction; /* Overall correction required. */
+   double file_inverse;     /* Inverse of file gamma. */
+   double screen_gamma;
+   double screen_inverse;   /* Inverse of screen gamma. */
+   double background_red;   /* Linear background value, red or gray. */
+   double background_green;
+   double background_blue;
+   double maxabs;
+   double maxpc;
+   double maxcalc;
+   double maxout;
+   double maxout_total;     /* Total including quantization error */
+   double outlog;
+   int    outquant;
+}
+validate_info;
+static void
+init_validate_info(validate_info *vi, gamma_display *dp, png_struct *pp,
+    int in_depth, int out_depth)
+{
+   PNG_CONST unsigned int outmax = (1U<<out_depth)-1;
+   vi->pp = pp;
+   vi->dp = dp;
+   if (dp->sbit > 0 && dp->sbit < in_depth)
+   {
+      vi->sbit = dp->sbit;
+      vi->isbit_shift = in_depth - dp->sbit;
+   }
+   else
+   {
+      vi->sbit = (png_byte)in_depth;
+      vi->isbit_shift = 0;
+   }
+   vi->sbit_max = (1U << vi->sbit)-1;
+   /* This mimics the libpng threshold test, '0' is used to prevent gamma
+    * correction in the validation test.
+    */
+   vi->screen_gamma = dp->screen_gamma;
+   if (fabs(vi->screen_gamma-1) < PNG_GAMMA_THRESHOLD)
+      vi->screen_gamma = vi->screen_inverse = 0;
+   else
+      vi->screen_inverse = 1/vi->screen_gamma;
+   vi->use_input_precision = dp->use_input_precision;
+   vi->outmax = outmax;
+   vi->maxabs = abserr(dp->pm, in_depth, out_depth);
+   vi->maxpc = pcerr(dp->pm, in_depth, out_depth);
+   vi->maxcalc = calcerr(dp->pm, in_depth, out_depth);
+   vi->maxout = outerr(dp->pm, in_depth, out_depth);
+   vi->outquant = output_quantization_factor(dp->pm, in_depth, out_depth);
+   vi->maxout_total = vi->maxout + vi->outquant * .5;
+   vi->outlog = outlog(dp->pm, in_depth, out_depth);
+   if ((dp->this.colour_type & PNG_COLOR_MASK_ALPHA) != 0 ||
+      (dp->this.colour_type == 3 && dp->this.is_transparent))
+   {
+      vi->do_background = dp->do_background;
+      if (vi->do_background != 0)
+      {
+         PNG_CONST double bg_inverse = 1/dp->background_gamma;
+         double r, g, b;
+         /* Caller must at least put the gray value into the red channel */
+         r = dp->background_color.red; r /= outmax;
+         g = dp->background_color.green; g /= outmax;
+         b = dp->background_color.blue; b /= outmax;
+#     if 0
+         /* libpng doesn't do this optimization, if we do pngvalid will fail.
+          */
+         if (fabs(bg_inverse-1) >= PNG_GAMMA_THRESHOLD)
+#     endif
+         {
+            r = pow(r, bg_inverse);
+            g = pow(g, bg_inverse);
+            b = pow(b, bg_inverse);
+         }
+         vi->background_red = r;
+         vi->background_green = g;
+         vi->background_blue = b;
+      }
+   }
+   else
+      vi->do_background = 0;
+   if (vi->do_background == 0)
+      vi->background_red = vi->background_green = vi->background_blue = 0;
+   vi->gamma_correction = 1/(dp->file_gamma*dp->screen_gamma);
+   if (fabs(vi->gamma_correction-1) < PNG_GAMMA_THRESHOLD)
+      vi->gamma_correction = 0;
+   vi->file_inverse = 1/dp->file_gamma;
+   if (fabs(vi->file_inverse-1) < PNG_GAMMA_THRESHOLD)
+      vi->file_inverse = 0;
+   vi->scale16 = dp->scale16;
+}
+/* This function handles composition of a single non-alpha component.  The
+ * argument is the input sample value, in the range 0..1, and the alpha value.
+ * The result is the composed, linear, input sample.  If alpha is less than zero
+ * this is the alpha component and the function should not be called!
+ */
+static double
+gamma_component_compose(int do_background, double input_sample, double alpha,
+   double background, int *compose)
+{
+   switch (do_background)
+   {
+      case PNG_BACKGROUND_GAMMA_SCREEN:
+      case PNG_BACKGROUND_GAMMA_FILE:
+      case PNG_BACKGROUND_GAMMA_UNIQUE:
+         /* Standard PNG background processing. */
+         if (alpha < 1)
+         {
+            if (alpha > 0)
+            {
+               input_sample = input_sample * alpha + background * (1-alpha);
+               if (compose != NULL)
+                  *compose = 1;
+            }
+            else
+               input_sample = background;
+         }
+         break;
+#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+      case ALPHA_MODE_OFFSET + PNG_ALPHA_STANDARD:
+      case ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN:
+         /* The components are premultiplied in either case and the output is
+          * gamma encoded (to get standard Porter-Duff we expect the output
+          * gamma to be set to 1.0!)
+          */
+      case ALPHA_MODE_OFFSET + PNG_ALPHA_OPTIMIZED:
+         /* The optimization is that the partial-alpha entries are linear
+          * while the opaque pixels are gamma encoded, but this only affects the
+          * output encoding.
+          */
+         if (alpha < 1)
+         {
+            if (alpha > 0)
+            {
+               input_sample *= alpha;
+               if (compose != NULL)
+                  *compose = 1;
+            }
+            else
+               input_sample = 0;
+         }
+         break;
+#endif
+      default:
+         /* Standard cases where no compositing is done (so the component
+          * value is already correct.)
+          */
+         break;
+   }
+   return input_sample;
+}
+/* This API returns the encoded *input* component, in the range 0..1 */
+static double
+gamma_component_validate(PNG_CONST char *name, PNG_CONST validate_info *vi,
+    PNG_CONST unsigned int id, PNG_CONST unsigned int od,
+    PNG_CONST double alpha /* <0 for the alpha channel itself */,
+    PNG_CONST double background /* component background value */)
+{
+   PNG_CONST unsigned int isbit = id >> vi->isbit_shift;
+   PNG_CONST unsigned int sbit_max = vi->sbit_max;
+   PNG_CONST unsigned int outmax = vi->outmax;
+   PNG_CONST int do_background = vi->do_background;
+   double i;
+   /* First check on the 'perfect' result obtained from the digitized input
+    * value, id, and compare this against the actual digitized result, 'od'.
+    * 'i' is the input result in the range 0..1:
+    */
+   i = isbit; i /= sbit_max;
+   /* Check for the fast route: if we don't do any background composition or if
+    * this is the alpha channel ('alpha' < 0) or if the pixel is opaque then
+    * just use the gamma_correction field to correct to the final output gamma.
+    */
+   if (alpha == 1 /* opaque pixel component */ || !do_background
+#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+      || do_background == ALPHA_MODE_OFFSET + PNG_ALPHA_PNG
+#endif
+      || (alpha < 0 /* alpha channel */
+#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+      && do_background != ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN
+#endif
+      ))
+   {
+      /* Then get the gamma corrected version of 'i' and compare to 'od', any
+       * error less than .5 is insignificant - just quantization of the output
+       * value to the nearest digital value (nevertheless the error is still
+       * recorded - it's interesting ;-)
+       */
+      double encoded_sample = i;
+      double encoded_error;
+      /* alpha less than 0 indicates the alpha channel, which is always linear
+       */
+      if (alpha >= 0 && vi->gamma_correction > 0)
+         encoded_sample = pow(encoded_sample, vi->gamma_correction);
+      encoded_sample *= outmax;
+      encoded_error = fabs(od-encoded_sample);
+      if (encoded_error > vi->dp->maxerrout)
+         vi->dp->maxerrout = encoded_error;
+      if (encoded_error < vi->maxout_total && encoded_error < vi->outlog)
+         return i;
+   }
+   /* The slow route - attempt to do linear calculations. */
+   /* There may be an error, or background processing is required, so calculate
+    * the actual sample values - unencoded light intensity values.  Note that in
+    * practice these are not completely unencoded because they include a
+    * 'viewing correction' to decrease or (normally) increase the perceptual
+    * contrast of the image.  There's nothing we can do about this - we don't
+    * know what it is - so assume the unencoded value is perceptually linear.
+    */
+   {
+      double input_sample = i; /* In range 0..1 */
+      double output, error, encoded_sample, encoded_error;
+      double es_lo, es_hi;
+      int compose = 0;           /* Set to one if composition done */
+      int output_is_encoded;     /* Set if encoded to screen gamma */
+      int log_max_error = 1;     /* Check maximum error values */
+      png_const_charp pass = 0;  /* Reason test passes (or 0 for fail) */
+      /* Convert to linear light (with the above caveat.)  The alpha channel is
+       * already linear.
+       */
+      if (alpha >= 0)
+      {
+         int tcompose;
+         if (vi->file_inverse > 0)
+            input_sample = pow(input_sample, vi->file_inverse);
+         /* Handle the compose processing: */
+         tcompose = 0;
+         input_sample = gamma_component_compose(do_background, input_sample,
+            alpha, background, &tcompose);
+         if (tcompose)
+            compose = 1;
+      }
+      /* And similarly for the output value, but we need to check the background
+       * handling to linearize it correctly.
+       */
+      output = od;
+      output /= outmax;
+      output_is_encoded = vi->screen_gamma > 0;
+      if (alpha < 0) /* The alpha channel */
+      {
+#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+         if (do_background != ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN)
+#endif
+         {
+            /* In all other cases the output alpha channel is linear already,
+             * don't log errors here, they are much larger in linear data.
+             */
+            output_is_encoded = 0;
+            log_max_error = 0;
+         }
+      }
+#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+      else /* A component */
+      {
+         if (do_background == ALPHA_MODE_OFFSET + PNG_ALPHA_OPTIMIZED &&
+            alpha < 1) /* the optimized case - linear output */
+         {
+            if (alpha > 0) log_max_error = 0;
+            output_is_encoded = 0;
+         }
+      }
+#endif
+      if (output_is_encoded)
+         output = pow(output, vi->screen_gamma);
+      /* Calculate (or recalculate) the encoded_sample value and repeat the
+       * check above (unnecessary if we took the fast route, but harmless.)
+       */
+      encoded_sample = input_sample;
+      if (output_is_encoded)
+         encoded_sample = pow(encoded_sample, vi->screen_inverse);
+      encoded_sample *= outmax;
+      encoded_error = fabs(od-encoded_sample);
+      /* Don't log errors in the alpha channel, or the 'optimized' case,
+       * neither are significant to the overall perception.
+       */
+      if (log_max_error && encoded_error > vi->dp->maxerrout)
+         vi->dp->maxerrout = encoded_error;
+      if (encoded_error < vi->maxout_total)
+      {
+         if (encoded_error < vi->outlog)
+            return i;
+         /* Test passed but error is bigger than the log limit, record why the
+          * test passed:
+          */
+         pass = "less than maxout:\n";
+      }
+      /* i: the original input value in the range 0..1
+       *
+       * pngvalid calculations:
+       *  input_sample: linear result; i linearized and composed, range 0..1
+       *  encoded_sample: encoded result; input_sample scaled to ouput bit depth
+       *
+       * libpng calculations:
+       *  output: linear result; od scaled to 0..1 and linearized
+       *  od: encoded result from libpng
+       */
+      /* Now we have the numbers for real errors, both absolute values as as a
+       * percentage of the correct value (output):
+       */
+      error = fabs(input_sample-output);
+      if (log_max_error && error > vi->dp->maxerrabs)
+         vi->dp->maxerrabs = error;
+      /* The following is an attempt to ignore the tendency of quantization to
+       * dominate the percentage errors for lower result values:
+       */
+      if (log_max_error && input_sample > .5)
+      {
+         double percentage_error = error/input_sample;
+         if (percentage_error > vi->dp->maxerrpc)
+            vi->dp->maxerrpc = percentage_error;
+      }
+      /* Now calculate the digitization limits for 'encoded_sample' using the
+       * 'max' values.  Note that maxout is in the encoded space but maxpc and
+       * maxabs are in linear light space.
+       *
+       * First find the maximum error in linear light space, range 0..1:
+       */
+      {
+         double tmp = input_sample * vi->maxpc;
+         if (tmp < vi->maxabs) tmp = vi->maxabs;
+         /* If 'compose' is true the composition was done in linear space using
+          * integer arithmetic.  This introduces an extra error of +/- 0.5 (at
+          * least) in the integer space used.  'maxcalc' records this, taking
+          * into account the possibility that even for 16 bit output 8 bit space
+          * may have been used.
+          */
+         if (compose && tmp < vi->maxcalc) tmp = vi->maxcalc;
+         /* The 'maxout' value refers to the encoded result, to compare with
+          * this encode input_sample adjusted by the maximum error (tmp) above.
+          */
+         es_lo = encoded_sample - vi->maxout;
+         if (es_lo > 0 && input_sample-tmp > 0)
+         {
+            double low_value = input_sample-tmp;
+            if (output_is_encoded)
+               low_value = pow(low_value, vi->screen_inverse);
+            low_value *= outmax;
+            if (low_value < es_lo) es_lo = low_value;
+            /* Quantize this appropriately: */
+            es_lo = ceil(es_lo / vi->outquant - .5) * vi->outquant;
+         }
+         else
+            es_lo = 0;
+         es_hi = encoded_sample + vi->maxout;
+         if (es_hi < outmax && input_sample+tmp < 1)
+         {
+            double high_value = input_sample+tmp;
+            if (output_is_encoded)
+               high_value = pow(high_value, vi->screen_inverse);
+            high_value *= outmax;
+            if (high_value > es_hi) es_hi = high_value;
+            es_hi = floor(es_hi / vi->outquant + .5) * vi->outquant;
+         }
+         else
+            es_hi = outmax;
+      }
+      /* The primary test is that the final encoded value returned by the
+       * library should be between the two limits (inclusive) that were
+       * calculated above.
+       */
+      if (od >= es_lo && od <= es_hi)
+      {
+         /* The value passes, but we may need to log the information anyway. */
+         if (encoded_error < vi->outlog)
+            return i;
+         if (pass == 0)
+            pass = "within digitization limits:\n";
+      }
+      {
+         /* There has been an error in processing, or we need to log this
+          * value.
+          */
+         double is_lo, is_hi;
+         /* pass is set at this point if either of the tests above would have
+          * passed.  Don't do these additional tests here - just log the
+          * original [es_lo..es_hi] values.
+          */
+         if (pass == 0 && vi->use_input_precision)
+         {
+            /* Ok, something is wrong - this actually happens in current libpng
+             * 16-to-8 processing.  Assume that the input value (id, adjusted
+             * for sbit) can be anywhere between value-.5 and value+.5 - quite a
+             * large range if sbit is low.
+             */
+            double tmp = (isbit - .5)/sbit_max;
+            if (tmp <= 0)
+               tmp = 0;
+            else if (alpha >= 0 && vi->file_inverse > 0 && tmp < 1)
+               tmp = pow(tmp, vi->file_inverse);
+            tmp = gamma_component_compose(do_background, tmp, alpha, background,
+               NULL);
+            if (output_is_encoded && tmp > 0 && tmp < 1)
+               tmp = pow(tmp, vi->screen_inverse);
+            is_lo = ceil(outmax * tmp - vi->maxout_total);
+            if (is_lo < 0)
+               is_lo = 0;
+            tmp = (isbit + .5)/sbit_max;
+            if (tmp <= 0)
+               tmp = 0;
+            else if (alpha >= 0 && vi->file_inverse > 0 && tmp < 1)
+               tmp = pow(tmp, vi->file_inverse);
+            tmp = gamma_component_compose(do_background, tmp, alpha, background,
+               NULL);
+            if (output_is_encoded && tmp > 0 && tmp < 1)
+               tmp = pow(tmp, vi->screen_inverse);
+            is_hi = floor(outmax * tmp + vi->maxout_total);
+            if (is_hi > outmax)
+               is_hi = outmax;
+            if (!(od < is_lo || od > is_hi))
+            {
+               if (encoded_error < vi->outlog)
+                  return i;
+               pass = "within input precision limits:\n";
+            }
+            /* One last chance.  If this is an alpha channel and the 16to8
+             * option has been used and 'inaccurate' scaling is used then the
+             * bit reduction is obtained by simply using the top 8 bits of the
+             * value.
+             *
+             * This is only done for older libpng versions when the 'inaccurate'
+             * (chop) method of scaling was used.
+             */
+#           ifndef PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED
+#              if PNG_LIBPNG_VER < 10504
+                  /* This may be required for other components in the future,
+                   * but at present the presence of gamma correction effectively
+                   * prevents the errors in the component scaling (I don't quite
+                   * understand why, but since it's better this way I care not
+                   * to ask, JB 20110419.)
+                   */
+                  if (pass == 0 && alpha < 0 && vi->scale16 && vi->sbit > 8 &&
+                     vi->sbit + vi->isbit_shift == 16)
+                  {
+                     tmp = ((id >> 8) - .5)/255;
+                     if (tmp > 0)
+                     {
+                        is_lo = ceil(outmax * tmp - vi->maxout_total);
+                        if (is_lo < 0) is_lo = 0;
+                     }
+                     else
+                        is_lo = 0;
+                     tmp = ((id >> 8) + .5)/255;
+                     if (tmp < 1)
+                     {
+                        is_hi = floor(outmax * tmp + vi->maxout_total);
+                        if (is_hi > outmax) is_hi = outmax;
+                     }
+                     else
+                        is_hi = outmax;
+                     if (!(od < is_lo || od > is_hi))
+                     {
+                        if (encoded_error < vi->outlog)
+                           return i;
+                        pass = "within 8 bit limits:\n";
+                     }
+                  }
+#              endif
+#           endif
+         }
+         else /* !use_input_precision */
+            is_lo = es_lo, is_hi = es_hi;
+         /* Attempt to output a meaningful error/warning message: the message
+          * output depends on the background/composite operation being performed
+          * because this changes what parameters were actually used above.
+          */
+         {
+            size_t pos = 0;
+            /* Need either 1/255 or 1/65535 precision here; 3 or 6 decimal
+             * places.  Just use outmax to work out which.
+             */
+            int precision = (outmax >= 1000 ? 6 : 3);
+            int use_input=1, use_background=0, do_compose=0;
+            char msg[256];
+            if (pass != 0)
+               pos = safecat(msg, sizeof msg, pos, "\n\t");
+            /* Set up the various flags, the output_is_encoded flag above
+             * is also used below.  do_compose is just a double check.
+             */
+            switch (do_background)
+            {
+            case PNG_BACKGROUND_GAMMA_SCREEN:
+            case PNG_BACKGROUND_GAMMA_FILE:
+            case PNG_BACKGROUND_GAMMA_UNIQUE:
+               use_background = (alpha >= 0 && alpha < 1);
+               /*FALL THROUGH*/
+#           ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+               case ALPHA_MODE_OFFSET + PNG_ALPHA_STANDARD:
+               case ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN:
+               case ALPHA_MODE_OFFSET + PNG_ALPHA_OPTIMIZED:
+#           endif /* ALPHA_MODE_SUPPORTED */
+               do_compose = (alpha > 0 && alpha < 1);
+               use_input = (alpha != 0);
+               break;
+            default:
+               break;
+            }
+            /* Check the 'compose' flag */
+            if (compose != do_compose)
+               png_error(vi->pp, "internal error (compose)");
+            /* 'name' is the component name */
+            pos = safecat(msg, sizeof msg, pos, name);
+            pos = safecat(msg, sizeof msg, pos, "(");
+            pos = safecatn(msg, sizeof msg, pos, id);
+            if (use_input || pass != 0/*logging*/)
+            {
+               if (isbit != id)
+               {
+                  /* sBIT has reduced the precision of the input: */
+                  pos = safecat(msg, sizeof msg, pos, ", sbit(");
+                  pos = safecatn(msg, sizeof msg, pos, vi->sbit);
+                  pos = safecat(msg, sizeof msg, pos, "): ");
+                  pos = safecatn(msg, sizeof msg, pos, isbit);
+               }
+               pos = safecat(msg, sizeof msg, pos, "/");
+               /* The output is either "id/max" or "id sbit(sbit): isbit/max" */
+               pos = safecatn(msg, sizeof msg, pos, vi->sbit_max);
+            }
+            pos = safecat(msg, sizeof msg, pos, ")");
+            /* A component may have been multiplied (in linear space) by the
+             * alpha value, 'compose' says whether this is relevant.
+             */
+            if (compose || pass != 0)
+            {
+               /* If any form of composition is being done report our
+                * calculated linear value here (the code above doesn't record
+                * the input value before composition is performed, so what
+                * gets reported is the value after composition.)
+                */
+               if (use_input || pass != 0)
+               {
+                  if (vi->file_inverse > 0)
+                  {
+                     pos = safecat(msg, sizeof msg, pos, "^");
+                     pos = safecatd(msg, sizeof msg, pos, vi->file_inverse, 2);
+                  }
+                  else
+                     pos = safecat(msg, sizeof msg, pos, "[linear]");
+                  pos = safecat(msg, sizeof msg, pos, "*(alpha)");
+                  pos = safecatd(msg, sizeof msg, pos, alpha, precision);
+               }
+               /* Now record the *linear* background value if it was used
+                * (this function is not passed the original, non-linear,
+                * value but it is contained in the test name.)
+                */
+               if (use_background)
+               {
+                  pos = safecat(msg, sizeof msg, pos, use_input ? "+" : " ");
+                  pos = safecat(msg, sizeof msg, pos, "(background)");
+                  pos = safecatd(msg, sizeof msg, pos, background, precision);
+                  pos = safecat(msg, sizeof msg, pos, "*");
+                  pos = safecatd(msg, sizeof msg, pos, 1-alpha, precision);
+               }
+            }
+            /* Report the calculated value (input_sample) and the linearized
+             * libpng value (output) unless this is just a component gamma
+             * correction.
+             */
+            if (compose || alpha < 0 || pass != 0)
+            {
+               pos = safecat(msg, sizeof msg, pos,
+                  pass != 0 ? " =\n\t" : " = ");
+               pos = safecatd(msg, sizeof msg, pos, input_sample, precision);
+               pos = safecat(msg, sizeof msg, pos, " (libpng: ");
+               pos = safecatd(msg, sizeof msg, pos, output, precision);
+               pos = safecat(msg, sizeof msg, pos, ")");
+               /* Finally report the output gamma encoding, if any. */
+               if (output_is_encoded)
+               {
+                  pos = safecat(msg, sizeof msg, pos, " ^");
+                  pos = safecatd(msg, sizeof msg, pos, vi->screen_inverse, 2);
+                  pos = safecat(msg, sizeof msg, pos, "(to screen) =");
+               }
+               else
+                  pos = safecat(msg, sizeof msg, pos, " [screen is linear] =");
+            }
+            if ((!compose && alpha >= 0) || pass != 0)
+            {
+               if (pass != 0) /* logging */
+                  pos = safecat(msg, sizeof msg, pos, "\n\t[overall:");
+               /* This is the non-composition case, the internal linear
+                * values are irrelevant (though the log below will reveal
+                * them.)  Output a much shorter warning/error message and report
+                * the overall gamma correction.
+                */
+               if (vi->gamma_correction > 0)
+               {
+                  pos = safecat(msg, sizeof msg, pos, " ^");
+                  pos = safecatd(msg, sizeof msg, pos, vi->gamma_correction, 2);
+                  pos = safecat(msg, sizeof msg, pos, "(gamma correction) =");
+               }
+               else
+                  pos = safecat(msg, sizeof msg, pos,
+                     " [no gamma correction] =");
+               if (pass != 0)
+                  pos = safecat(msg, sizeof msg, pos, "]");
+            }
+            /* This is our calculated encoded_sample which should (but does
+             * not) match od:
+             */
+            pos = safecat(msg, sizeof msg, pos, pass != 0 ? "\n\t" : " ");
+            pos = safecatd(msg, sizeof msg, pos, is_lo, 1);
+            pos = safecat(msg, sizeof msg, pos, " < ");
+            pos = safecatd(msg, sizeof msg, pos, encoded_sample, 1);
+            pos = safecat(msg, sizeof msg, pos, " (libpng: ");
+            pos = safecatn(msg, sizeof msg, pos, od);
+            pos = safecat(msg, sizeof msg, pos, ")");
+            pos = safecat(msg, sizeof msg, pos, "/");
+            pos = safecatn(msg, sizeof msg, pos, outmax);
+            pos = safecat(msg, sizeof msg, pos, " < ");
+            pos = safecatd(msg, sizeof msg, pos, is_hi, 1);
+            if (pass == 0) /* The error condition */
+            {
+#              ifdef PNG_WARNINGS_SUPPORTED
+                  png_warning(vi->pp, msg);
+#              else
+                  store_warning(vi->pp, msg);
+#              endif
+            }
+            else /* logging this value */
+               store_verbose(&vi->dp->pm->this, vi->pp, pass, msg);
+         }
+      }
+   }
+   return i;
+}
+static void
+gamma_image_validate(gamma_display *dp, png_structp pp, png_infop pi)
+{
+   /* Get some constants derived from the input and output file formats: */
+   PNG_CONST png_store* PNG_CONST ps = dp->this.ps;
+   PNG_CONST png_byte in_ct = dp->this.colour_type;
+   PNG_CONST png_byte in_bd = dp->this.bit_depth;
+   PNG_CONST png_uint_32 w = dp->this.w;
+   PNG_CONST png_uint_32 h = dp->this.h;
+   PNG_CONST size_t cbRow = dp->this.cbRow;
+   PNG_CONST png_byte out_ct = png_get_color_type(pp, pi);
+   PNG_CONST png_byte out_bd = png_get_bit_depth(pp, pi);
+   /* There are three sources of error, firstly the quantization in the
+    * file encoding, determined by sbit and/or the file depth, secondly
+    * the output (screen) gamma and thirdly the output file encoding.
+    *
+    * Since this API receives the screen and file gamma in double
+    * precision it is possible to calculate an exact answer given an input
+    * pixel value.  Therefore we assume that the *input* value is exact -
+    * sample/maxsample - calculate the corresponding gamma corrected
+    * output to the limits of double precision arithmetic and compare with
+    * what libpng returns.
+    *
+    * Since the library must quantize the output to 8 or 16 bits there is
+    * a fundamental limit on the accuracy of the output of +/-.5 - this
+    * quantization limit is included in addition to the other limits
+    * specified by the paramaters to the API.  (Effectively, add .5
+    * everywhere.)
+    *
+    * The behavior of the 'sbit' paramter is defined by section 12.5
+    * (sample depth scaling) of the PNG spec.  That section forces the
+    * decoder to assume that the PNG values have been scaled if sBIT is
+    * present:
+    *
+    *     png-sample = floor( input-sample * (max-out/max-in) + .5);
+    *
+    * This means that only a subset of the possible PNG values should
+    * appear in the input. However, the spec allows the encoder to use a
+    * variety of approximations to the above and doesn't require any
+    * restriction of the values produced.
+    *
+    * Nevertheless the spec requires that the upper 'sBIT' bits of the
+    * value stored in a PNG file be the original sample bits.
+    * Consequently the code below simply scales the top sbit bits by
+    * (1<<sbit)-1 to obtain an original sample value.
+    *
+    * Because there is limited precision in the input it is arguable that
+    * an acceptable result is any valid result from input-.5 to input+.5.
+    * The basic tests below do not do this, however if 'use_input_precision'
+    * is set a subsequent test is performed below.
+    */
+   PNG_CONST unsigned int samples_per_pixel = (out_ct & 2U) ? 3U : 1U;
+   int processing;
+   png_uint_32 y;
+   PNG_CONST store_palette_entry *in_palette = dp->this.palette;
+   PNG_CONST int in_is_transparent = dp->this.is_transparent;
+   int out_npalette = -1;
+   int out_is_transparent = 0; /* Just refers to the palette case */
+   store_palette out_palette;
+   validate_info vi;
+   /* Check for row overwrite errors */
+   store_image_check(dp->this.ps, pp, 0);
+   /* Supply the input and output sample depths here - 8 for an indexed image,
+    * otherwise the bit depth.
+    */
+   init_validate_info(&vi, dp, pp, in_ct==3?8:in_bd, out_ct==3?8:out_bd);
+   processing = (vi.gamma_correction > 0 && !dp->threshold_test)
+      || in_bd != out_bd || in_ct != out_ct || vi.do_background;
+   /* TODO: FIX THIS: MAJOR BUG!  If the transformations all happen inside
+    * the palette there is no way of finding out, because libpng fails to
+    * update the palette on png_read_update_info.  Indeed, libpng doesn't
+    * even do the required work until much later, when it doesn't have any
+    * info pointer.  Oops.  For the moment 'processing' is turned off if
+    * out_ct is palette.
+    */
+   if (in_ct == 3 && out_ct == 3)
+      processing = 0;
+   if (processing && out_ct == 3)
+      out_is_transparent = read_palette(out_palette, &out_npalette, pp, pi);
+   for (y=0; y<h; ++y)
+   {
+      png_const_bytep pRow = store_image_row(ps, pp, 0, y);
+      png_byte std[STANDARD_ROWMAX];
+      transform_row(pp, std, in_ct, in_bd, y);
+      if (processing)
+      {
+         unsigned int x;
+         for (x=0; x<w; ++x)
+         {
+            double alpha = 1; /* serves as a flag value */
+            /* Record the palette index for index images. */
+            PNG_CONST unsigned int in_index =
+               in_ct == 3 ? sample(std, 3, in_bd, x, 0) : 256;
+            PNG_CONST unsigned int out_index =
+               out_ct == 3 ? sample(std, 3, out_bd, x, 0) : 256;
+            /* Handle input alpha - png_set_background will cause the output
+             * alpha to disappear so there is nothing to check.
+             */
+            if ((in_ct & PNG_COLOR_MASK_ALPHA) != 0 || (in_ct == 3 &&
+               in_is_transparent))
+            {
+               PNG_CONST unsigned int input_alpha = in_ct == 3 ?
+                  dp->this.palette[in_index].alpha :
+                  sample(std, in_ct, in_bd, x, samples_per_pixel);
+               unsigned int output_alpha = 65536 /* as a flag value */;
+               if (out_ct == 3)
+               {
+                  if (out_is_transparent)
+                     output_alpha = out_palette[out_index].alpha;
+               }
+               else if ((out_ct & PNG_COLOR_MASK_ALPHA) != 0)
+                  output_alpha = sample(pRow, out_ct, out_bd, x,
+                     samples_per_pixel);
+               if (output_alpha != 65536)
+                  alpha = gamma_component_validate("alpha", &vi, input_alpha,
+                     output_alpha, -1/*alpha*/, 0/*background*/);
+               else /* no alpha in output */
+               {
+                  /* This is a copy of the calculation of 'i' above in order to
+                   * have the alpha value to use in the background calculation.
+                   */
+                  alpha = input_alpha >> vi.isbit_shift;
+                  alpha /= vi.sbit_max;
+               }
+            }
+            /* Handle grayscale or RGB components. */
+            if ((in_ct & PNG_COLOR_MASK_COLOR) == 0) /* grayscale */
+               (void)gamma_component_validate("gray", &vi,
+                  sample(std, in_ct, in_bd, x, 0),
+                  sample(pRow, out_ct, out_bd, x, 0), alpha/*component*/,
+                  vi.background_red);
+            else /* RGB or palette */
+            {
+               (void)gamma_component_validate("red", &vi,
+                  in_ct == 3 ? in_palette[in_index].red :
+                     sample(std, in_ct, in_bd, x, 0),
+                  out_ct == 3 ? out_palette[out_index].red :
+                     sample(pRow, out_ct, out_bd, x, 0),
+                  alpha/*component*/, vi.background_red);
+               (void)gamma_component_validate("green", &vi,
+                  in_ct == 3 ? in_palette[in_index].green :
+                     sample(std, in_ct, in_bd, x, 1),
+                  out_ct == 3 ? out_palette[out_index].green :
+                     sample(pRow, out_ct, out_bd, x, 1),
+                  alpha/*component*/, vi.background_green);
+               (void)gamma_component_validate("blue", &vi,
+                  in_ct == 3 ? in_palette[in_index].blue :
+                     sample(std, in_ct, in_bd, x, 2),
+                  out_ct == 3 ? out_palette[out_index].blue :
+                     sample(pRow, out_ct, out_bd, x, 2),
+                  alpha/*component*/, vi.background_blue);
+            }
+         }
+      }
+      else if (memcmp(std, pRow, cbRow) != 0)
+      {
+         char msg[64];
+         /* No transform is expected on the threshold tests. */
+         sprintf(msg, "gamma: below threshold row %d changed", y);
+         png_error(pp, msg);
+      }
+   } /* row (y) loop */
+   dp->this.ps->validated = 1;
+}
+static void
+gamma_end(png_structp pp, png_infop pi)
+{
+   gamma_display *dp = voidcast(gamma_display*, png_get_progressive_ptr(pp));
+   if (!dp->this.speed)
+      gamma_image_validate(dp, pp, pi);
+   else
+      dp->this.ps->validated = 1;
+}
+/* A single test run checking a gamma transformation.
+ *
+ * maxabs: maximum absolute error as a fraction
+ * maxout: maximum output error in the output units
+ * maxpc:  maximum percentage error (as a percentage)
+ */
+static void
+gamma_test(png_modifier *pmIn, PNG_CONST png_byte colour_typeIn,
+    PNG_CONST png_byte bit_depthIn, PNG_CONST int palette_numberIn,
+    PNG_CONST int interlace_typeIn,
+    PNG_CONST double file_gammaIn, PNG_CONST double screen_gammaIn,
+    PNG_CONST png_byte sbitIn, PNG_CONST int threshold_testIn,
+    PNG_CONST char *name,
+    PNG_CONST int use_input_precisionIn, PNG_CONST int scale16In,
+    PNG_CONST int expand16In, PNG_CONST int do_backgroundIn,
+    PNG_CONST png_color_16 *bkgd_colorIn, double bkgd_gammaIn)
+{
+   gamma_display d;
+   context(&pmIn->this, fault);
+   gamma_display_init(&d, pmIn, FILEID(colour_typeIn, bit_depthIn,
+      palette_numberIn, interlace_typeIn, 0, 0, 0),
+      file_gammaIn, screen_gammaIn, sbitIn,
+      threshold_testIn, use_input_precisionIn, scale16In,
+      expand16In, do_backgroundIn, bkgd_colorIn, bkgd_gammaIn);
+   Try
+   {
+      png_structp pp;
+      png_infop pi;
+      gama_modification gama_mod;
+      srgb_modification srgb_mod;
+      sbit_modification sbit_mod;
+      /* For the moment don't use the png_modifier support here. */
+      d.pm->encoding_counter = 0;
+      modifier_set_encoding(d.pm); /* Just resets everything */
+      d.pm->current_gamma = d.file_gamma;
+      /* Make an appropriate modifier to set the PNG file gamma to the
+       * given gamma value and the sBIT chunk to the given precision.
+       */
+      d.pm->modifications = NULL;
+      gama_modification_init(&gama_mod, d.pm, d.file_gamma);
+      srgb_modification_init(&srgb_mod, d.pm, 127 /*delete*/);
+      if (d.sbit > 0)
+         sbit_modification_init(&sbit_mod, d.pm, d.sbit);
+      modification_reset(d.pm->modifications);
+      /* Get a png_struct for writing the image. */
+      pp = set_modifier_for_read(d.pm, &pi, d.this.id, name);
+      standard_palette_init(&d.this);
+      /* Introduce the correct read function. */
+      if (d.pm->this.progressive)
+      {
+         /* Share the row function with the standard implementation. */
+         png_set_progressive_read_fn(pp, &d, gamma_info, progressive_row,
+            gamma_end);
+         /* Now feed data into the reader until we reach the end: */
+         modifier_progressive_read(d.pm, pp, pi);
+      }
+      else
+      {
+         /* modifier_read expects a png_modifier* */
+         png_set_read_fn(pp, d.pm, modifier_read);
+         /* Check the header values: */
+         png_read_info(pp, pi);
+         /* Process the 'info' requirements. Only one image is generated */
+         gamma_info_imp(&d, pp, pi);
+         sequential_row(&d.this, pp, pi, -1, 0);
+         if (!d.this.speed)
+            gamma_image_validate(&d, pp, pi);
+         else
+            d.this.ps->validated = 1;
+      }
+      modifier_reset(d.pm);
+      if (d.pm->log && !d.threshold_test && !d.this.speed)
+         fprintf(stderr, "%d bit %s %s: max error %f (%.2g, %2g%%)\n",
+            d.this.bit_depth, colour_types[d.this.colour_type], name,
+            d.maxerrout, d.maxerrabs, 100*d.maxerrpc);
+      /* Log the summary values too. */
+      if (d.this.colour_type == 0 || d.this.colour_type == 4)
+      {
+         switch (d.this.bit_depth)
+         {
+         case 1:
+            break;
+         case 2:
+            if (d.maxerrout > d.pm->error_gray_2)
+               d.pm->error_gray_2 = d.maxerrout;
+            break;
+         case 4:
+            if (d.maxerrout > d.pm->error_gray_4)
+               d.pm->error_gray_4 = d.maxerrout;
+            break;
+         case 8:
+            if (d.maxerrout > d.pm->error_gray_8)
+               d.pm->error_gray_8 = d.maxerrout;
+            break;
+         case 16:
+            if (d.maxerrout > d.pm->error_gray_16)
+               d.pm->error_gray_16 = d.maxerrout;
+            break;
+         default:
+            png_error(pp, "bad bit depth (internal: 1)");
+         }
+      }
+      else if (d.this.colour_type == 2 || d.this.colour_type == 6)
+      {
+         switch (d.this.bit_depth)
+         {
+         case 8:
+            if (d.maxerrout > d.pm->error_color_8)
+               d.pm->error_color_8 = d.maxerrout;
+            break;
+         case 16:
+            if (d.maxerrout > d.pm->error_color_16)
+               d.pm->error_color_16 = d.maxerrout;
+            break;
+         default:
+            png_error(pp, "bad bit depth (internal: 2)");
+         }
+      }
+      else if (d.this.colour_type == 3)
+      {
+         if (d.maxerrout > d.pm->error_indexed)
+            d.pm->error_indexed = d.maxerrout;
+      }
+   }
+   Catch(fault)
+      modifier_reset((png_modifier*)fault);
+}
+static void gamma_threshold_test(png_modifier *pm, png_byte colour_type,
+    png_byte bit_depth, int interlace_type, double file_gamma,
+    double screen_gamma)
+{
+   size_t pos = 0;
+   char name[64];
+   pos = safecat(name, sizeof name, pos, "threshold ");
+   pos = safecatd(name, sizeof name, pos, file_gamma, 3);
+   pos = safecat(name, sizeof name, pos, "/");
+   pos = safecatd(name, sizeof name, pos, screen_gamma, 3);
+   (void)gamma_test(pm, colour_type, bit_depth, 0/*palette*/, interlace_type,
+      file_gamma, screen_gamma, 0/*sBIT*/, 1/*threshold test*/, name,
+      0 /*no input precision*/,
+      0 /*no scale16*/, 0 /*no expand16*/, 0 /*no background*/, 0 /*hence*/,
+      0 /*no background gamma*/);
+}
+static void
+perform_gamma_threshold_tests(png_modifier *pm)
+{
+   png_byte colour_type = 0;
+   png_byte bit_depth = 0;
+   int palette_number = 0;
+   /* Don't test more than one instance of each palette - it's pointless, in
+    * fact this test is somewhat excessive since libpng doesn't make this
+    * decision based on colour type or bit depth!
+    */
+   while (next_format(&colour_type, &bit_depth, &palette_number))
+      if (palette_number == 0)
+   {
+      double test_gamma = 1.0;
+      while (test_gamma >= .4)
+      {
+         /* There's little point testing the interlacing vs non-interlacing,
+          * but this can be set from the command line.
+          */
+         gamma_threshold_test(pm, colour_type, bit_depth, pm->interlace_type,
+            test_gamma, 1/test_gamma);
+         test_gamma *= .95;
+      }
+      /* And a special test for sRGB */
+      gamma_threshold_test(pm, colour_type, bit_depth, pm->interlace_type,
+          .45455, 2.2);
+      if (fail(pm))
+         return;
+   }
+}
+static void gamma_transform_test(png_modifier *pm,
+   PNG_CONST png_byte colour_type, PNG_CONST png_byte bit_depth,
+   PNG_CONST int palette_number,
+   PNG_CONST int interlace_type, PNG_CONST double file_gamma,
+   PNG_CONST double screen_gamma, PNG_CONST png_byte sbit,
+   PNG_CONST int use_input_precision, PNG_CONST int scale16)
+{
+   size_t pos = 0;
+   char name[64];
+   if (sbit != bit_depth && sbit != 0)
+   {
+      pos = safecat(name, sizeof name, pos, "sbit(");
+      pos = safecatn(name, sizeof name, pos, sbit);
+      pos = safecat(name, sizeof name, pos, ") ");
+   }
+   else
+      pos = safecat(name, sizeof name, pos, "gamma ");
+   if (scale16)
+      pos = safecat(name, sizeof name, pos, "16to8 ");
+   pos = safecatd(name, sizeof name, pos, file_gamma, 3);
+   pos = safecat(name, sizeof name, pos, "->");
+   pos = safecatd(name, sizeof name, pos, screen_gamma, 3);
+   gamma_test(pm, colour_type, bit_depth, palette_number, interlace_type,
+      file_gamma, screen_gamma, sbit, 0, name, use_input_precision,
+      scale16, pm->test_gamma_expand16, 0 , 0, 0);
+}
+static void perform_gamma_transform_tests(png_modifier *pm)
+{
+   png_byte colour_type = 0;
+   png_byte bit_depth = 0;
+   int palette_number = 0;
+   while (next_format(&colour_type, &bit_depth, &palette_number))
+   {
+      unsigned int i, j;
+      for (i=0; i<pm->ngamma_tests; ++i) for (j=0; j<pm->ngamma_tests; ++j)
+         if (i != j)
+         {
+            gamma_transform_test(pm, colour_type, bit_depth, palette_number,
+               pm->interlace_type, 1/pm->gammas[i], pm->gammas[j], 0/*sBIT*/,
+               pm->use_input_precision, 0 /*do not scale16*/);
+            if (fail(pm))
+               return;
+         }
+   }
+}
+static void perform_gamma_sbit_tests(png_modifier *pm)
+{
+   png_byte sbit;
+   /* The only interesting cases are colour and grayscale, alpha is ignored here
+    * for overall speed.  Only bit depths where sbit is less than the bit depth
+    * are tested.
+    */
+   for (sbit=pm->sbitlow; sbit<(1<<READ_BDHI); ++sbit)
+   {
+      png_byte colour_type, bit_depth;
+      int npalette;
+      colour_type = bit_depth = 0;
+      npalette = 0;
+      while (next_format(&colour_type, &bit_depth, &npalette))
+         if ((colour_type & PNG_COLOR_MASK_ALPHA) == 0 &&
+            ((colour_type == 3 && sbit < 8) ||
+            (colour_type != 3 && sbit < bit_depth)))
+      {
+         unsigned int i;
+         for (i=0; i<pm->ngamma_tests; ++i)
+         {
+            unsigned int j;
+            for (j=0; j<pm->ngamma_tests; ++j) if (i != j)
+            {
+               gamma_transform_test(pm, colour_type, bit_depth, npalette,
+                  pm->interlace_type, 1/pm->gammas[i], pm->gammas[j],
+                  sbit, pm->use_input_precision_sbit, 0 /*scale16*/);
+               if (fail(pm))
+                  return;
+            }
+         }
+      }
+   }
+}
+/* Note that this requires a 16 bit source image but produces 8 bit output, so
+ * we only need the 16bit write support, but the 16 bit images are only
+ * generated if DO_16BIT is defined.
+ */
+#ifdef DO_16BIT
+static void perform_gamma_scale16_tests(png_modifier *pm)
+{
+#  ifndef PNG_MAX_GAMMA_8
+#     define PNG_MAX_GAMMA_8 11
+#  endif
+   /* Include the alpha cases here. Note that sbit matches the internal value
+    * used by the library - otherwise we will get spurious errors from the
+    * internal sbit style approximation.
+    *
+    * The threshold test is here because otherwise the 16 to 8 conversion will
+    * proceed *without* gamma correction, and the tests above will fail (but not
+    * by much) - this could be fixed, it only appears with the -g option.
+    */
+   unsigned int i, j;
+   for (i=0; i<pm->ngamma_tests; ++i)
+   {
+      for (j=0; j<pm->ngamma_tests; ++j)
+      {
+         if (i != j &&
+             fabs(pm->gammas[j]/pm->gammas[i]-1) >= PNG_GAMMA_THRESHOLD)
+         {
+            gamma_transform_test(pm, 0, 16, 0, pm->interlace_type,
+               1/pm->gammas[i], pm->gammas[j], PNG_MAX_GAMMA_8,
+               pm->use_input_precision_16to8, 1 /*scale16*/);
+            if (fail(pm))
+               return;
+            gamma_transform_test(pm, 2, 16, 0, pm->interlace_type,
+               1/pm->gammas[i], pm->gammas[j], PNG_MAX_GAMMA_8,
+               pm->use_input_precision_16to8, 1 /*scale16*/);
+            if (fail(pm))
+               return;
+            gamma_transform_test(pm, 4, 16, 0, pm->interlace_type,
+               1/pm->gammas[i], pm->gammas[j], PNG_MAX_GAMMA_8,
+               pm->use_input_precision_16to8, 1 /*scale16*/);
+            if (fail(pm))
+               return;
+            gamma_transform_test(pm, 6, 16, 0, pm->interlace_type,
+               1/pm->gammas[i], pm->gammas[j], PNG_MAX_GAMMA_8,
+               pm->use_input_precision_16to8, 1 /*scale16*/);
+            if (fail(pm))
+               return;
+         }
+      }
+   }
+}
+#endif /* 16 to 8 bit conversion */
+#if defined PNG_READ_BACKGROUND_SUPPORTED ||\
+   defined PNG_READ_ALPHA_MODE_SUPPORTED
+static void gamma_composition_test(png_modifier *pm,
+   PNG_CONST png_byte colour_type, PNG_CONST png_byte bit_depth,
+   PNG_CONST int palette_number,
+   PNG_CONST int interlace_type, PNG_CONST double file_gamma,
+   PNG_CONST double screen_gamma,
+   PNG_CONST int use_input_precision, PNG_CONST int do_background,
+   PNG_CONST int expand_16)
+{
+   size_t pos = 0;
+   png_const_charp base;
+   double bg;
+   char name[128];
+   png_color_16 background;
+   /* Make up a name and get an appropriate background gamma value. */
+   switch (do_background)
+   {
+      default:
+         base = "";
+         bg = 4; /* should not be used */
+         break;
+      case PNG_BACKGROUND_GAMMA_SCREEN:
+         base = " bckg(Screen):";
+         bg = 1/screen_gamma;
+         break;
+      case PNG_BACKGROUND_GAMMA_FILE:
+         base = " bckg(File):";
+         bg = file_gamma;
+         break;
+      case PNG_BACKGROUND_GAMMA_UNIQUE:
+         base = " bckg(Unique):";
+         /* This tests the handling of a unique value, the math is such that the
+          * value tends to be <1, but is neither screen nor file (even if they
+          * match!)
+          */
+         bg = (file_gamma + screen_gamma) / 3;
+         break;
+#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+      case ALPHA_MODE_OFFSET + PNG_ALPHA_PNG:
+         base = " alpha(PNG)";
+         bg = 4; /* should not be used */
+         break;
+      case ALPHA_MODE_OFFSET + PNG_ALPHA_STANDARD:
+         base = " alpha(Porter-Duff)";
+         bg = 4; /* should not be used */
+         break;
+      case ALPHA_MODE_OFFSET + PNG_ALPHA_OPTIMIZED:
+         base = " alpha(Optimized)";
+         bg = 4; /* should not be used */
+         break;
+      case ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN:
+         base = " alpha(Broken)";
+         bg = 4; /* should not be used */
+         break;
+#endif
+   }
+   /* Use random background values - the background is always presented in the
+    * output space (8 or 16 bit components).
+    */
+   if (expand_16 || bit_depth == 16)
+   {
+      png_uint_32 r = random_32();
+      background.red = (png_uint_16)r;
+      background.green = (png_uint_16)(r >> 16);
+      r = random_32();
+      background.blue = (png_uint_16)r;
+      background.gray = (png_uint_16)(r >> 16);
+   }
+   else /* 8 bit colors */
+   {
+      png_uint_32 r = random_32();
+      background.red = (png_byte)r;
+      background.green = (png_byte)(r >> 8);
+      background.blue = (png_byte)(r >> 16);
+      background.gray = (png_byte)(r >> 24);
+   }
+   background.index = 193; /* rgb(193,193,193) to detect errors */
+   if (!(colour_type & PNG_COLOR_MASK_COLOR))
+   {
+      /* Grayscale input, we do not convert to RGB (TBD), so we must set the
+       * background to gray - else libpng seems to fail.
+       */
+      background.red = background.green = background.blue = background.gray;
+   }
+   pos = safecat(name, sizeof name, pos, "gamma ");
+   pos = safecatd(name, sizeof name, pos, file_gamma, 3);
+   pos = safecat(name, sizeof name, pos, "->");
+   pos = safecatd(name, sizeof name, pos, screen_gamma, 3);
+   pos = safecat(name, sizeof name, pos, base);
+   if (do_background < ALPHA_MODE_OFFSET)
+   {
+      /* Include the background color and gamma in the name: */
+      pos = safecat(name, sizeof name, pos, "(");
+      /* This assumes no expand gray->rgb - the current code won't handle that!
+       */
+      if (colour_type & PNG_COLOR_MASK_COLOR)
+      {
+         pos = safecatn(name, sizeof name, pos, background.red);
+         pos = safecat(name, sizeof name, pos, ",");
+         pos = safecatn(name, sizeof name, pos, background.green);
+         pos = safecat(name, sizeof name, pos, ",");
+         pos = safecatn(name, sizeof name, pos, background.blue);
+      }
+      else
+         pos = safecatn(name, sizeof name, pos, background.gray);
+      pos = safecat(name, sizeof name, pos, ")^");
+      pos = safecatd(name, sizeof name, pos, bg, 3);
+   }
+   gamma_test(pm, colour_type, bit_depth, palette_number, interlace_type,
+      file_gamma, screen_gamma, 0/*sBIT*/, 0, name, use_input_precision,
+      0/*strip 16*/, expand_16, do_background, &background, bg);
+}
+static void
+perform_gamma_composition_tests(png_modifier *pm, int do_background,
+   int expand_16)
+{
+   png_byte colour_type = 0;
+   png_byte bit_depth = 0;
+   int palette_number = 0;
+   /* Skip the non-alpha cases - there is no setting of a transparency colour at
+    * present.
+    */
+   while (next_format(&colour_type, &bit_depth, &palette_number))
+      if ((colour_type & PNG_COLOR_MASK_ALPHA) != 0)
+   {
+      unsigned int i, j;
+      /* Don't skip the i==j case here - it's relevant. */
+      for (i=0; i<pm->ngamma_tests; ++i) for (j=0; j<pm->ngamma_tests; ++j)
+      {
+         gamma_composition_test(pm, colour_type, bit_depth, palette_number,
+            pm->interlace_type, 1/pm->gammas[i], pm->gammas[j],
+            pm->use_input_precision, do_background, expand_16);
+         if (fail(pm))
+            return;
+      }
+   }
+}
+#endif /* READ_BACKGROUND || READ_ALPHA_MODE */
+static void
+init_gamma_errors(png_modifier *pm)
+{
+   pm->error_gray_2 = pm->error_gray_4 = pm->error_gray_8 = 0;
+   pm->error_color_8 = 0;
+   pm->error_indexed = 0;
+   pm->error_gray_16 = pm->error_color_16 = 0;
+}
+static void
+summarize_gamma_errors(png_modifier *pm, png_const_charp who, int low_bit_depth)
+{
+   if (who)
+      printf("Gamma correction with %s:\n", who);
+   if (low_bit_depth)
+   {
+      printf("  2 bit gray:  %.5f\n", pm->error_gray_2);
+      printf("  4 bit gray:  %.5f\n", pm->error_gray_4);
+      printf("  8 bit gray:  %.5f\n", pm->error_gray_8);
+      printf("  8 bit color: %.5f\n", pm->error_color_8);
+      printf("  indexed:     %.5f\n", pm->error_indexed);
+   }
+#ifdef DO_16BIT
+   printf(" 16 bit gray:  %.5f\n", pm->error_gray_16);
+   printf(" 16 bit color: %.5f\n", pm->error_color_16);
+#endif
+}
+static void
+perform_gamma_test(png_modifier *pm, int summary)
+{
+   /*TODO: remove this*/
+   /* Save certain values for the temporary overrides below. */
+   unsigned int calculations_use_input_precision =
+      pm->calculations_use_input_precision;
+   double maxout8 = pm->maxout8;
+   /* First some arbitrary no-transform tests: */
+   if (!pm->this.speed && pm->test_gamma_threshold)
+   {
+      perform_gamma_threshold_tests(pm);
+      if (fail(pm))
+         return;
+   }
+   /* Now some real transforms. */
+   if (pm->test_gamma_transform)
+   {
+      init_gamma_errors(pm);
+      /*TODO: remove this.  Necessary because the current libpng
+       * implementation works in 8 bits:
+       */
+      if (pm->test_gamma_expand16)
+         pm->calculations_use_input_precision = 1;
+      perform_gamma_transform_tests(pm);
+      if (!calculations_use_input_precision)
+         pm->calculations_use_input_precision = 0;
+      if (summary)
+      {
+         printf("Gamma correction error summary\n\n");
+         printf("The printed value is the maximum error in the pixel values\n");
+         printf("calculated by the libpng gamma correction code.  The error\n");
+         printf("is calculated as the difference between the output pixel\n");
+         printf("value (always an integer) and the ideal value from the\n");
+         printf("libpng specification (typically not an integer).\n\n");
+         printf("Expect this value to be less than .5 for 8 bit formats,\n");
+         printf("less than 1 for formats with fewer than 8 bits and a small\n");
+         printf("number (typically less than 5) for the 16 bit formats.\n");
+         printf("For performance reasons the value for 16 bit formats\n");
+         printf("increases when the image file includes an sBIT chunk.\n\n");
+         summarize_gamma_errors(pm, 0/*who*/, 1);
+      }
+   }
+   /* The sbit tests produce much larger errors: */
+   if (pm->test_gamma_sbit)
+   {
+      init_gamma_errors(pm);
+      perform_gamma_sbit_tests(pm);
+      if (summary)
+         summarize_gamma_errors(pm, "sBIT", pm->sbitlow < 8U);
+   }
+#ifdef DO_16BIT /* Should be READ_16BIT_SUPPORTED */
+   if (pm->test_gamma_scale16)
+   {
+      /* The 16 to 8 bit strip operations: */
+      init_gamma_errors(pm);
+      perform_gamma_scale16_tests(pm);
+      if (summary)
+      {
+         printf("Gamma correction with 16 to 8 bit reduction:\n");
+         printf(" 16 bit gray:  %.5f\n", pm->error_gray_16);
+         printf(" 16 bit color: %.5f\n", pm->error_color_16);
+      }
+   }
+#endif
+#ifdef PNG_READ_BACKGROUND_SUPPORTED
+   if (pm->test_gamma_background)
+   {
+      init_gamma_errors(pm);
+      /*TODO: remove this.  Necessary because the current libpng
+       * implementation works in 8 bits:
+       */
+      if (pm->test_gamma_expand16)
+      {
+         pm->calculations_use_input_precision = 1;
+         pm->maxout8 = .499; /* because the 16 bit background is smashed */
+      }
+      perform_gamma_composition_tests(pm, PNG_BACKGROUND_GAMMA_UNIQUE,
+         pm->test_gamma_expand16);
+      if (!calculations_use_input_precision)
+         pm->calculations_use_input_precision = 0;
+      pm->maxout8 = maxout8;
+      if (summary)
+         summarize_gamma_errors(pm, "background", 1);
+   }
+#endif
+#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+   if (pm->test_gamma_alpha_mode)
+   {
+      int do_background;
+      init_gamma_errors(pm);
+      /*TODO: remove this.  Necessary because the current libpng
+       * implementation works in 8 bits:
+       */
+      if (pm->test_gamma_expand16)
+         pm->calculations_use_input_precision = 1;
+      for (do_background = ALPHA_MODE_OFFSET + PNG_ALPHA_STANDARD;
+         do_background <= ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN && !fail(pm);
+         ++do_background)
+         perform_gamma_composition_tests(pm, do_background,
+            pm->test_gamma_expand16);
+      if (!calculations_use_input_precision)
+         pm->calculations_use_input_precision = 0;
+      if (summary)
+         summarize_gamma_errors(pm, "alpha mode", 1);
+   }
+#endif
+}
+#endif /* PNG_READ_GAMMA_SUPPORTED */
+/* INTERLACE MACRO VALIDATION */
+/* This is copied verbatim from the specification, it is simply the pass
+ * number in which each pixel in each 8x8 tile appears.  The array must
+ * be indexed adam7[y][x] and notice that the pass numbers are based at
+ * 1, not 0 - the base libpng uses.
+ */
+static PNG_CONST
+png_byte adam7[8][8] =
+{
+   { 1,6,4,6,2,6,4,6 },
+   { 7,7,7,7,7,7,7,7 },
+   { 5,6,5,6,5,6,5,6 },
+   { 7,7,7,7,7,7,7,7 },
+   { 3,6,4,6,3,6,4,6 },
+   { 7,7,7,7,7,7,7,7 },
+   { 5,6,5,6,5,6,5,6 },
+   { 7,7,7,7,7,7,7,7 }
+};
+/* This routine validates all the interlace support macros in png.h for
+ * a variety of valid PNG widths and heights.  It uses a number of similarly
+ * named internal routines that feed off the above array.
+ */
+static png_uint_32
+png_pass_start_row(int pass)
+{
+   int x, y;
+   ++pass;
+   for (y=0; y<8; ++y) for (x=0; x<8; ++x) if (adam7[y][x] == pass)
+      return y;
+   return 0xf;
+}
+static png_uint_32
+png_pass_start_col(int pass)
+{
+   int x, y;
+   ++pass;
+   for (x=0; x<8; ++x) for (y=0; y<8; ++y) if (adam7[y][x] == pass)
+      return x;
+   return 0xf;
+}
+static int
+png_pass_row_shift(int pass)
+{
+   int x, y, base=(-1), inc=8;
+   ++pass;
+   for (y=0; y<8; ++y) for (x=0; x<8; ++x) if (adam7[y][x] == pass)
+   {
+      if (base == (-1))
+         base = y;
+      else if (base == y)
+         {}
+      else if (inc == y-base)
+         base=y;
+      else if (inc == 8)
+         inc = y-base, base=y;
+      else if (inc != y-base)
+         return 0xff; /* error - more than one 'inc' value! */
+   }
+   if (base == (-1)) return 0xfe; /* error - no row in pass! */
+   /* The shift is always 1, 2 or 3 - no pass has all the rows! */
+   switch (inc)
+   {
+case 2: return 1;
+case 4: return 2;
+case 8: return 3;
+default: break;
+   }
+   /* error - unrecognized 'inc' */
+   return (inc << 8) + 0xfd;
+}
+static int
+png_pass_col_shift(int pass)
+{
+   int x, y, base=(-1), inc=8;
+   ++pass;
+   for (x=0; x<8; ++x) for (y=0; y<8; ++y) if (adam7[y][x] == pass)
+   {
+      if (base == (-1))
+         base = x;
+      else if (base == x)
+         {}
+      else if (inc == x-base)
+         base=x;
+      else if (inc == 8)
+         inc = x-base, base=x;
+      else if (inc != x-base)
+         return 0xff; /* error - more than one 'inc' value! */
+   }
+   if (base == (-1)) return 0xfe; /* error - no row in pass! */
+   /* The shift is always 1, 2 or 3 - no pass has all the rows! */
+   switch (inc)
+   {
+case 1: return 0; /* pass 7 has all the columns */
+case 2: return 1;
+case 4: return 2;
+case 8: return 3;
+default: break;
+   }
+   /* error - unrecognized 'inc' */
+   return (inc << 8) + 0xfd;
+}
+static png_uint_32
+png_row_from_pass_row(png_uint_32 yIn, int pass)
+{
+   /* By examination of the array: */
+   switch (pass)
+   {
+case 0: return yIn * 8;
+case 1: return yIn * 8;
+case 2: return yIn * 8 + 4;
+case 3: return yIn * 4;
+case 4: return yIn * 4 + 2;
+case 5: return yIn * 2;
+case 6: return yIn * 2 + 1;
+default: break;
+   }
+   return 0xff; /* bad pass number */
+}
+static png_uint_32
+png_col_from_pass_col(png_uint_32 xIn, int pass)
+{
+   /* By examination of the array: */
+   switch (pass)
+   {
+case 0: return xIn * 8;
+case 1: return xIn * 8 + 4;
+case 2: return xIn * 4;
+case 3: return xIn * 4 + 2;
+case 4: return xIn * 2;
+case 5: return xIn * 2 + 1;
+case 6: return xIn;
+default: break;
+   }
+   return 0xff; /* bad pass number */
+}
+static int
+png_row_in_interlace_pass(png_uint_32 y, int pass)
+{
+   /* Is row 'y' in pass 'pass'? */
+   int x;
+   y &= 7;
+   ++pass;
+   for (x=0; x<8; ++x) if (adam7[y][x] == pass)
+      return 1;
+   return 0;
+}
+static int
+png_col_in_interlace_pass(png_uint_32 x, int pass)
+{
+   /* Is column 'x' in pass 'pass'? */
+   int y;
+   x &= 7;
+   ++pass;
+   for (y=0; y<8; ++y) if (adam7[y][x] == pass)
+      return 1;
+   return 0;
+}
+static png_uint_32
+png_pass_rows(png_uint_32 height, int pass)
+{
+   png_uint_32 tiles = height>>3;
+   png_uint_32 rows = 0;
+   unsigned int x, y;
+   height &= 7;
+   ++pass;
+   for (y=0; y<8; ++y) for (x=0; x<8; ++x) if (adam7[y][x] == pass)
+   {
+      rows += tiles;
+      if (y < height) ++rows;
+      break; /* i.e. break the 'x', column, loop. */
+   }
+   return rows;
+}
+static png_uint_32
+png_pass_cols(png_uint_32 width, int pass)
+{
+   png_uint_32 tiles = width>>3;
+   png_uint_32 cols = 0;
+   unsigned int x, y;
+   width &= 7;
+   ++pass;
+   for (x=0; x<8; ++x) for (y=0; y<8; ++y) if (adam7[y][x] == pass)
+   {
+      cols += tiles;
+      if (x < width) ++cols;
+      break; /* i.e. break the 'y', row, loop. */
+   }
+   return cols;
+}
+static void
+perform_interlace_macro_validation(void)
+{
+   /* The macros to validate, first those that depend only on pass:
+    *
+    * PNG_PASS_START_ROW(pass)
+    * PNG_PASS_START_COL(pass)
+    * PNG_PASS_ROW_SHIFT(pass)
+    * PNG_PASS_COL_SHIFT(pass)
+    */
+   int pass;
+   for (pass=0; pass<7; ++pass)
+   {
+      png_uint_32 m, f, v;
+      m = PNG_PASS_START_ROW(pass);
+      f = png_pass_start_row(pass);
+      if (m != f)
+      {
+         fprintf(stderr, "PNG_PASS_START_ROW(%d) = %u != %x\n", pass, m, f);
+         exit(1);
+      }
+      m = PNG_PASS_START_COL(pass);
+      f = png_pass_start_col(pass);
+      if (m != f)
+      {
+         fprintf(stderr, "PNG_PASS_START_COL(%d) = %u != %x\n", pass, m, f);
+         exit(1);
+      }
+      m = PNG_PASS_ROW_SHIFT(pass);
+      f = png_pass_row_shift(pass);
+      if (m != f)
+      {
+         fprintf(stderr, "PNG_PASS_ROW_SHIFT(%d) = %u != %x\n", pass, m, f);
+         exit(1);
+      }
+      m = PNG_PASS_COL_SHIFT(pass);
+      f = png_pass_col_shift(pass);
+      if (m != f)
+      {
+         fprintf(stderr, "PNG_PASS_COL_SHIFT(%d) = %u != %x\n", pass, m, f);
+         exit(1);
+      }
+      /* Macros that depend on the image or sub-image height too:
+       *
+       * PNG_PASS_ROWS(height, pass)
+       * PNG_PASS_COLS(width, pass)
+       * PNG_ROW_FROM_PASS_ROW(yIn, pass)
+       * PNG_COL_FROM_PASS_COL(xIn, pass)
+       * PNG_ROW_IN_INTERLACE_PASS(y, pass)
+       * PNG_COL_IN_INTERLACE_PASS(x, pass)
+       */
+      for (v=0;;)
+      {
+         /* First the base 0 stuff: */
+         m = PNG_ROW_FROM_PASS_ROW(v, pass);
+         f = png_row_from_pass_row(v, pass);
+         if (m != f)
+         {
+            fprintf(stderr, "PNG_ROW_FROM_PASS_ROW(%u, %d) = %u != %x\n",
+               v, pass, m, f);
+            exit(1);
+         }
+         m = PNG_COL_FROM_PASS_COL(v, pass);
+         f = png_col_from_pass_col(v, pass);
+         if (m != f)
+         {
+            fprintf(stderr, "PNG_COL_FROM_PASS_COL(%u, %d) = %u != %x\n",
+               v, pass, m, f);
+            exit(1);
+         }
+         m = PNG_ROW_IN_INTERLACE_PASS(v, pass);
+         f = png_row_in_interlace_pass(v, pass);
+         if (m != f)
+         {
+            fprintf(stderr, "PNG_ROW_IN_INTERLACE_PASS(%u, %d) = %u != %x\n",
+               v, pass, m, f);
+            exit(1);
+         }
+         m = PNG_COL_IN_INTERLACE_PASS(v, pass);
+         f = png_col_in_interlace_pass(v, pass);
+         if (m != f)
+         {
+            fprintf(stderr, "PNG_COL_IN_INTERLACE_PASS(%u, %d) = %u != %x\n",
+               v, pass, m, f);
+            exit(1);
+         }
+         /* Then the base 1 stuff: */
+         ++v;
+         m = PNG_PASS_ROWS(v, pass);
+         f = png_pass_rows(v, pass);
+         if (m != f)
+         {
+            fprintf(stderr, "PNG_PASS_ROWS(%u, %d) = %u != %x\n",
+               v, pass, m, f);
+            exit(1);
+         }
+         m = PNG_PASS_COLS(v, pass);
+         f = png_pass_cols(v, pass);
+         if (m != f)
+         {
+            fprintf(stderr, "PNG_PASS_COLS(%u, %d) = %u != %x\n",
+               v, pass, m, f);
+            exit(1);
+         }
+         /* Move to the next v - the stepping algorithm starts skipping
+          * values above 1024.
+          */
+         if (v > 1024)
+         {
+            if (v == PNG_UINT_31_MAX)
+               break;
+            v = (v << 1) ^ v;
+            if (v >= PNG_UINT_31_MAX)
+               v = PNG_UINT_31_MAX-1;
+         }
+      }
+   }
+}
+/* Test color encodings. These values are back-calculated from the published
+ * chromaticities.  The values are accurate to about 14 decimal places; 15 are
+ * given.  These values are much more accurate than the ones given in the spec,
+ * which typically don't exceed 4 decimal places.  This allows testing of the
+ * libpng code to its theoretical accuracy of 4 decimal places.  (If pngvalid
+ * used the published errors the 'slack' permitted would have to be +/-.5E-4 or
+ * more.)
+ *
+ * The png_modifier code assumes that encodings[0] is sRGB and treats it
+ * specially: do not change the first entry in this list!
+ */
+static PNG_CONST color_encoding test_encodings[] =
+{
+/* sRGB: must be first in this list! */
+/*gamma:*/ { 1/2.2,
+/*red:  */ { 0.412390799265959, 0.212639005871510, 0.019330818715592 },
+/*green:*/ { 0.357584339383878, 0.715168678767756, 0.119194779794626 },
+/*blue: */ { 0.180480788401834, 0.072192315360734, 0.950532152249660} },
+/* Kodak ProPhoto (wide gamut) */
+/*gamma:*/ { 1/1.6 /*approximate: uses 1.8 power law compared to sRGB 2.4*/,
+/*red:  */ { 0.797760489672303, 0.288071128229293, 0.000000000000000 },
+/*green:*/ { 0.135185837175740, 0.711843217810102, 0.000000000000000 },
+/*blue: */ { 0.031349349581525, 0.000085653960605, 0.825104602510460} },
+/* Adobe RGB (1998) */
+/*gamma:*/ { 1/(2+51./256),
+/*red:  */ { 0.576669042910131, 0.297344975250536, 0.027031361386412 },
+/*green:*/ { 0.185558237906546, 0.627363566255466, 0.070688852535827 },
+/*blue: */ { 0.188228646234995, 0.075291458493998, 0.991337536837639} },
+/* Adobe Wide Gamut RGB */
+/*gamma:*/ { 1/(2+51./256),
+/*red:  */ { 0.716500716779386, 0.258728243040113, 0.000000000000000 },
+/*green:*/ { 0.101020574397477, 0.724682314948566, 0.051211818965388 },
+/*blue: */ { 0.146774385252705, 0.016589442011321, 0.773892783545073} },
+};
+/* signal handler
+ *
+ * This attempts to trap signals and escape without crashing.  It needs a
+ * context pointer so that it can throw an exception (call longjmp) to recover
+ * from the condition; this is handled by making the png_modifier used by 'main'
+ * into a global variable.
+ */
+static png_modifier pm;
+static void signal_handler(int signum)
+{
+   size_t pos = 0;
+   char msg[64];
+   pos = safecat(msg, sizeof msg, pos, "caught signal: ");
+   switch (signum)
+   {
+      case SIGABRT:
+         pos = safecat(msg, sizeof msg, pos, "abort");
+         break;
+      case SIGFPE:
+         pos = safecat(msg, sizeof msg, pos, "floating point exception");
+         break;
+      case SIGILL:
+         pos = safecat(msg, sizeof msg, pos, "illegal instruction");
+         break;
+      case SIGINT:
+         pos = safecat(msg, sizeof msg, pos, "interrupt");
+         break;
+      case SIGSEGV:
+         pos = safecat(msg, sizeof msg, pos, "invalid memory access");
+         break;
+      case SIGTERM:
+         pos = safecat(msg, sizeof msg, pos, "termination request");
+         break;
+      default:
+         pos = safecat(msg, sizeof msg, pos, "unknown ");
+         pos = safecatn(msg, sizeof msg, pos, signum);
+         break;
+   }
+   store_log(&pm.this, NULL/*png_structp*/, msg, 1/*error*/);
+   /* And finally throw an exception so we can keep going, unless this is
+    * SIGTERM in which case stop now.
+    */
+   if (signum != SIGTERM)
+   {
+      struct exception_context *the_exception_context =
+         &pm.this.exception_context;
+      Throw &pm.this;
+   }
+   else
+      exit(1);
+}
+/* main program */
+int main(int argc, PNG_CONST char **argv)
+{
+   volatile int summary = 1;  /* Print the error summary at the end */
+   volatile int memstats = 0; /* Print memory statistics at the end */
+   /* Create the given output file on success: */
+   PNG_CONST char *volatile touch = NULL;
+   /* This is an array of standard gamma values (believe it or not I've seen
+    * every one of these mentioned somewhere.)
+    *
+    * In the following list the most useful values are first!
+    */
+   static double
+      gammas[]={2.2, 1.0, 2.2/1.45, 1.8, 1.5, 2.4, 2.5, 2.62, 2.9};
+   /* This records the command and arguments: */
+   size_t cp = 0;
+   char command[1024];
+   anon_context(&pm.this);
+   /* Add appropriate signal handlers, just the ANSI specified ones: */
+   signal(SIGABRT, signal_handler);
+   signal(SIGFPE, signal_handler);
+   signal(SIGILL, signal_handler);
+   signal(SIGINT, signal_handler);
+   signal(SIGSEGV, signal_handler);
+   signal(SIGTERM, signal_handler);
+#ifdef HAVE_FEENABLEEXCEPT
+   /* Only required to enable FP exceptions on platforms where they start off
+    * disabled; this is not necessary but if it is not done pngvalid will likely
+    * end up ignoring FP conditions that other platforms fault.
+    */
+   feenableexcept(FE_DIVBYZERO | FE_INVALID | FE_OVERFLOW);
+#endif
+   modifier_init(&pm);
+   /* Preallocate the image buffer, because we know how big it needs to be,
+    * note that, for testing purposes, it is deliberately mis-aligned by tag
+    * bytes either side.  All rows have an additional five bytes of padding for
+    * overwrite checking.
+    */
+   store_ensure_image(&pm.this, NULL, 2, TRANSFORM_ROWMAX, TRANSFORM_HEIGHTMAX);
+   /* Don't give argv[0], it's normally some horrible libtool string: */
+   cp = safecat(command, sizeof command, cp, "pngvalid");
+   /* Default to error on warning: */
+   pm.this.treat_warnings_as_errors = 1;
+   /* Store the test gammas */
+   pm.gammas = gammas;
+   pm.ngammas = (sizeof gammas) / (sizeof gammas[0]);
+   pm.ngamma_tests = 0; /* default to off */
+   /* And the test encodings */
+   pm.encodings = test_encodings;
+   pm.nencodings = (sizeof test_encodings) / (sizeof test_encodings[0]);
+   pm.sbitlow = 8U; /* because libpng doesn't do sBIT below 8! */
+   /* The following allows results to pass if they correspond to anything in the
+    * transformed range [input-.5,input+.5]; this is is required because of the
+    * way libpng treates the 16_TO_8 flag when building the gamma tables.
+    *
+    * TODO: review this
+    */
+   pm.use_input_precision_16to8 = 1U;
+   /* Some default values (set the behavior for 'make check' here).
+    * These values simply control the maximum error permitted in the gamma
+    * transformations.  The practial limits for human perception are described
+    * below (the setting for maxpc16), however for 8 bit encodings it isn't
+    * possible to meet the accepted capabilities of human vision - i.e. 8 bit
+    * images can never be good enough, regardless of encoding.
+    */
+   pm.maxout8 = .1;     /* Arithmetic error in *encoded* value */
+   pm.maxabs8 = .00005; /* 1/20000 */
+   pm.maxcalc8 = .004;  /* +/-1 in 8 bits for compose errors */
+   pm.maxpc8 = .499;    /* I.e., .499% fractional error */
+   pm.maxout16 = .499;  /* Error in *encoded* value */
+   pm.maxabs16 = .00005;/* 1/20000 */
+   pm.maxcalc16 =.000015;/* +/-1 in 16 bits for compose errors */
+   /* NOTE: this is a reasonable perceptual limit. We assume that humans can
+    * perceive light level differences of 1% over a 100:1 range, so we need to
+    * maintain 1 in 10000 accuracy (in linear light space), which is what the
+    * following guarantees.  It also allows significantly higher errors at
+    * higher 16 bit values, which is important for performance.  The actual
+    * maximum 16 bit error is about +/-1.9 in the fixed point implementation but
+    * this is only allowed for values >38149 by the following:
+    */
+   pm.maxpc16 = .005;   /* I.e., 1/200% - 1/20000 */
+   /* Now parse the command line options. */
+   while (--argc >= 1)
+   {
+      int catmore = 0; /* Set if the argument has an argument. */
+      /* Record each argument for posterity: */
+      cp = safecat(command, sizeof command, cp, " ");
+      cp = safecat(command, sizeof command, cp, *++argv);
+      if (strcmp(*argv, "-v") == 0)
+         pm.this.verbose = 1;
+      else if (strcmp(*argv, "-l") == 0)
+         pm.log = 1;
+      else if (strcmp(*argv, "-q") == 0)
+         summary = pm.this.verbose = pm.log = 0;
+      else if (strcmp(*argv, "-w") == 0)
+         pm.this.treat_warnings_as_errors = 0;
+      else if (strcmp(*argv, "--speed") == 0)
+         pm.this.speed = 1, pm.ngamma_tests = pm.ngammas, pm.test_standard = 0,
+            summary = 0;
+      else if (strcmp(*argv, "--memory") == 0)
+         memstats = 1;
+      else if (strcmp(*argv, "--size") == 0)
+         pm.test_size = 1;
+      else if (strcmp(*argv, "--nosize") == 0)
+         pm.test_size = 0;
+      else if (strcmp(*argv, "--standard") == 0)
+         pm.test_standard = 1;
+      else if (strcmp(*argv, "--nostandard") == 0)
+         pm.test_standard = 0;
+      else if (strcmp(*argv, "--transform") == 0)
+         pm.test_transform = 1;
+      else if (strcmp(*argv, "--notransform") == 0)
+         pm.test_transform = 0;
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+      else if (strncmp(*argv, "--transform-disable=",
+         sizeof "--transform-disable") == 0)
+         {
+         pm.test_transform = 1;
+         transform_disable(*argv + sizeof "--transform-disable");
+         }
+      else if (strncmp(*argv, "--transform-enable=",
+         sizeof "--transform-enable") == 0)
+         {
+         pm.test_transform = 1;
+         transform_enable(*argv + sizeof "--transform-enable");
+         }
+#endif /* PNG_READ_TRANSFORMS_SUPPORTED */
+      else if (strcmp(*argv, "--gamma") == 0)
+         {
+         /* Just do two gamma tests here (2.2 and linear) for speed: */
+         pm.ngamma_tests = 2U;
+         pm.test_gamma_threshold = 1;
+         pm.test_gamma_transform = 1;
+         pm.test_gamma_sbit = 1;
+         pm.test_gamma_scale16 = 1;
+         pm.test_gamma_background = 1;
+         pm.test_gamma_alpha_mode = 1;
+         }
+      else if (strcmp(*argv, "--nogamma") == 0)
+         pm.ngamma_tests = 0;
+      else if (strcmp(*argv, "--gamma-threshold") == 0)
+         pm.ngamma_tests = 2U, pm.test_gamma_threshold = 1;
+      else if (strcmp(*argv, "--nogamma-threshold") == 0)
+         pm.test_gamma_threshold = 0;
+      else if (strcmp(*argv, "--gamma-transform") == 0)
+         pm.ngamma_tests = 2U, pm.test_gamma_transform = 1;
+      else if (strcmp(*argv, "--nogamma-transform") == 0)
+         pm.test_gamma_transform = 0;
+      else if (strcmp(*argv, "--gamma-sbit") == 0)
+         pm.ngamma_tests = 2U, pm.test_gamma_sbit = 1;
+      else if (strcmp(*argv, "--nogamma-sbit") == 0)
+         pm.test_gamma_sbit = 0;
+      else if (strcmp(*argv, "--gamma-16-to-8") == 0)
+         pm.ngamma_tests = 2U, pm.test_gamma_scale16 = 1;
+      else if (strcmp(*argv, "--nogamma-16-to-8") == 0)
+         pm.test_gamma_scale16 = 0;
+      else if (strcmp(*argv, "--gamma-background") == 0)
+         pm.ngamma_tests = 2U, pm.test_gamma_background = 1;
+      else if (strcmp(*argv, "--nogamma-background") == 0)
+         pm.test_gamma_background = 0;
+      else if (strcmp(*argv, "--gamma-alpha-mode") == 0)
+         pm.ngamma_tests = 2U, pm.test_gamma_alpha_mode = 1;
+      else if (strcmp(*argv, "--nogamma-alpha-mode") == 0)
+         pm.test_gamma_alpha_mode = 0;
+      else if (strcmp(*argv, "--expand16") == 0)
+         pm.test_gamma_expand16 = 1;
+      else if (strcmp(*argv, "--noexpand16") == 0)
+         pm.test_gamma_expand16 = 0;
+      else if (strcmp(*argv, "--more-gammas") == 0)
+         pm.ngamma_tests = 3U;
+      else if (strcmp(*argv, "--all-gammas") == 0)
+         pm.ngamma_tests = pm.ngammas;
+      else if (strcmp(*argv, "--progressive-read") == 0)
+         pm.this.progressive = 1;
+      else if (strcmp(*argv, "--use-update-info") == 0)
+         ++pm.use_update_info; /* Can call multiple times */
+      else if (strcmp(*argv, "--interlace") == 0)
+         pm.interlace_type = PNG_INTERLACE_ADAM7;
+      else if (strcmp(*argv, "--use-input-precision") == 0)
+         pm.use_input_precision = 1;
+      else if (strcmp(*argv, "--calculations-use-input-precision") == 0)
+         pm.calculations_use_input_precision = 1;
+      else if (strcmp(*argv, "--assume-16-bit-calculations") == 0)
+         pm.assume_16_bit_calculations = 1;
+      else if (strcmp(*argv, "--calculations-follow-bit-depth") == 0)
+         pm.calculations_use_input_precision =
+            pm.assume_16_bit_calculations = 0;
+      else if (strcmp(*argv, "--exhaustive") == 0)
+         pm.test_exhaustive = 1;
+      else if (argc > 1 && strcmp(*argv, "--sbitlow") == 0)
+         --argc, pm.sbitlow = (png_byte)atoi(*++argv), catmore = 1;
+      else if (argc > 1 && strcmp(*argv, "--touch") == 0)
+         --argc, touch = *++argv, catmore = 1;
+      else if (argc > 1 && strncmp(*argv, "--max", 5) == 0)
+      {
+         --argc;
+         if (strcmp(5+*argv, "abs8") == 0)
+            pm.maxabs8 = atof(*++argv);
+         else if (strcmp(5+*argv, "abs16") == 0)
+            pm.maxabs16 = atof(*++argv);
+         else if (strcmp(5+*argv, "calc8") == 0)
+            pm.maxcalc8 = atof(*++argv);
+         else if (strcmp(5+*argv, "calc16") == 0)
+            pm.maxcalc16 = atof(*++argv);
+         else if (strcmp(5+*argv, "out8") == 0)
+            pm.maxout8 = atof(*++argv);
+         else if (strcmp(5+*argv, "out16") == 0)
+            pm.maxout16 = atof(*++argv);
+         else if (strcmp(5+*argv, "pc8") == 0)
+            pm.maxpc8 = atof(*++argv);
+         else if (strcmp(5+*argv, "pc16") == 0)
+            pm.maxpc16 = atof(*++argv);
+         else
+         {
+            fprintf(stderr, "pngvalid: %s: unknown 'max' option\n", *argv);
+            exit(1);
+         }
+         catmore = 1;
+      }
+      else if (strcmp(*argv, "--log8") == 0)
+         --argc, pm.log8 = atof(*++argv), catmore = 1;
+      else if (strcmp(*argv, "--log16") == 0)
+         --argc, pm.log16 = atof(*++argv), catmore = 1;
+      else
+      {
+         fprintf(stderr, "pngvalid: %s: unknown argument\n", *argv);
+         exit(1);
+      }
+      if (catmore) /* consumed an extra *argv */
+      {
+         cp = safecat(command, sizeof command, cp, " ");
+         cp = safecat(command, sizeof command, cp, *argv);
+      }
+   }
+   /* If pngvalid is run with no arguments default to a reasonable set of the
+    * tests.
+    */
+   if (pm.test_standard == 0 && pm.test_size == 0 && pm.test_transform == 0 &&
+      pm.ngamma_tests == 0)
+   {
+      /* Make this do all the tests done in the test shell scripts with the same
+       * parameters, where possible.  The limitation is that all the progressive
+       * read and interlace stuff has to be done in separate runs, so only the
+       * basic 'standard' and 'size' tests are done.
+       */
+      pm.test_standard = 1;
+      pm.test_size = 1;
+      pm.test_transform = 1;
+      pm.ngamma_tests = 2U;
+   }
+   if (pm.ngamma_tests > 0 &&
+      pm.test_gamma_threshold == 0 && pm.test_gamma_transform == 0 &&
+      pm.test_gamma_sbit == 0 && pm.test_gamma_scale16 == 0 &&
+      pm.test_gamma_background == 0 && pm.test_gamma_alpha_mode == 0)
+   {
+      pm.test_gamma_threshold = 1;
+      pm.test_gamma_transform = 1;
+      pm.test_gamma_sbit = 1;
+      pm.test_gamma_scale16 = 1;
+      pm.test_gamma_background = 1;
+      pm.test_gamma_alpha_mode = 1;
+   }
+   else if (pm.ngamma_tests == 0)
+   {
+      /* Nothing to test so turn everything off: */
+      pm.test_gamma_threshold = 0;
+      pm.test_gamma_transform = 0;
+      pm.test_gamma_sbit = 0;
+      pm.test_gamma_scale16 = 0;
+      pm.test_gamma_background = 0;
+      pm.test_gamma_alpha_mode = 0;
+   }
+   Try
+   {
+      /* Make useful base images */
+      make_transform_images(&pm.this);
+      /* Perform the standard and gamma tests. */
+      if (pm.test_standard)
+      {
+         perform_interlace_macro_validation();
+         perform_formatting_test(&pm.this);
+         perform_standard_test(&pm);
+         perform_error_test(&pm);
+      }
+      /* Various oddly sized images: */
+      if (pm.test_size)
+      {
+         make_size_images(&pm.this);
+         perform_size_test(&pm);
+      }
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+      /* Combinatorial transforms: */
+      if (pm.test_transform)
+         perform_transform_test(&pm);
+#endif /* PNG_READ_TRANSFORMS_SUPPORTED */
+#ifdef PNG_READ_GAMMA_SUPPORTED
+      if (pm.ngamma_tests > 0)
+         perform_gamma_test(&pm, summary);
+#endif
+   }
+   Catch_anonymous
+   {
+      fprintf(stderr, "pngvalid: test aborted (probably failed in cleanup)\n");
+      if (!pm.this.verbose)
+      {
+         if (pm.this.error[0] != 0)
+            fprintf(stderr, "pngvalid: first error: %s\n", pm.this.error);
+         fprintf(stderr, "pngvalid: run with -v to see what happened\n");
+      }
+      exit(1);
+   }
+   if (summary)
+   {
+      printf("%s: %s (%s point arithmetic)\n",
+         (pm.this.nerrors || (pm.this.treat_warnings_as_errors &&
+            pm.this.nwarnings)) ? "FAIL" : "PASS",
+         command,
+#if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || PNG_LIBPNG_VER < 10500
+         "floating"
+#else
+         "fixed"
+#endif
+         );
+   }
+   if (memstats)
+   {
+      printf("Allocated memory statistics (in bytes):\n"
+         "\tread  %lu maximum single, %lu peak, %lu total\n"
+         "\twrite %lu maximum single, %lu peak, %lu total\n",
+         (unsigned long)pm.this.read_memory_pool.max_max,
+         (unsigned long)pm.this.read_memory_pool.max_limit,
+         (unsigned long)pm.this.read_memory_pool.max_total,
+         (unsigned long)pm.this.write_memory_pool.max_max,
+         (unsigned long)pm.this.write_memory_pool.max_limit,
+         (unsigned long)pm.this.write_memory_pool.max_total);
+   }
+   /* Do this here to provoke memory corruption errors in memory not directly
+    * allocated by libpng - not a complete test, but better than nothing.
+    */
+   store_delete(&pm.this);
+   /* Error exit if there are any errors, and maybe if there are any
+    * warnings.
+    */
+   if (pm.this.nerrors || (pm.this.treat_warnings_as_errors &&
+       pm.this.nwarnings))
+   {
+      if (!pm.this.verbose)
+         fprintf(stderr, "pngvalid: %s\n", pm.this.error);
+      fprintf(stderr, "pngvalid: %d errors, %d warnings\n", pm.this.nerrors,
+          pm.this.nwarnings);
+      exit(1);
+   }
+   /* Success case. */
+   if (touch != NULL)
+   {
+      FILE *fsuccess = fopen(touch, "wt");
+      if (fsuccess != NULL)
+      {
+         int error = 0;
+         fprintf(fsuccess, "PNG validation succeeded\n");
+         fflush(fsuccess);
+         error = ferror(fsuccess);
+         if (fclose(fsuccess) || error)
+         {
+            fprintf(stderr, "%s: write failed\n", touch);
+            exit(1);
+         }
+      }
+   }
+   return 0;
+}
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminim/decoder/README b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminim/decoder/README
new file mode 100644
index 0000000..86583cc
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminim/decoder/README
@@ -0,0 +1,10 @@
+This demonstrates the use of PNG_USER_CONFIG, pngusr.h and pngusr.dfa
+The makefile builds a minimal read-only decoder with embedded libpng
+and zlib.
+Specify the location of the zlib source (1.2.1 or later) as ZLIBSRC
+on the make command line.
+If you prefer to use the shared libraries, go to contrib/pngminus
+and build the png2pnm application there.
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminim/decoder/makefile b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminim/decoder/makefile
new file mode 100644
index 0000000..9692e0a
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminim/decoder/makefile
@@ -0,0 +1,150 @@
+# Makefile for PngMinus (pngm2pnm)
+# Linux / Unix
+#CC=cc
+CC=gcc
+LD=$(CC)
+# If awk fails try
+# make AWK=nawk
+# If cpp fails try
+# make CPP=/lib/cpp
+RM=rm -f
+COPY=cp
+CFLAGS=-DPNG_USER_CONFIG -DNO_GZCOMPRESS -DNO_GZIP -I. -O1
+C=.c
+O=.o
+L=.a
+E=
+# Where to find the source code:
+PNGSRC =../../..
+ZLIBSRC=$(PNGSRC)/../zlib
+PROGSRC=$(PNGSRC)/contrib/pngminus
+# Zlib (minimal inflate requirements - crc32 is used by libpng)
+# zutil can be eliminated if you provide your own zcalloc and zcfree
+ZSRCS  = adler32$(C) crc32$(C) \
+         inffast$(C) inflate$(C) inftrees$(C) \
+         zutil$(C)
+# Standard headers
+ZH     = zlib.h crc32.h inffast.h inffixed.h \
+         inflate.h inftrees.h zutil.h
+# Machine generated headers
+ZCONF  = zconf.h
+# Headers callers use
+ZINC   = zlib.h $(ZCONF)
+# Headers the Zlib source uses
+ZHDRS  = $(ZH) $(ZCONF)
+ZOBJS  = adler32$(O) crc32$(O) \
+         inffast$(O) inflate$(O) inftrees$(O) \
+         zutil$(O)
+# libpng
+PNGSRCS=png$(C) pngerror$(C) pngget$(C) pngmem$(C) \
+        pngread$(C) pngrio$(C) pngrtran$(C) pngrutil$(C) \
+        pngset$(C) pngtrans$(C)
+        
+# Standard headers
+PNGH   =png.h pngconf.h pngdebug.h pnginfo.h pngpriv.h pngstruct.h
+# Machine generated headers
+PNGCONF=pnglibconf.h
+# Headers callers use
+PNGINC= png.h pngconf.h pngusr.h $(PNGCONF)
+# Headers the PNG library uses
+PNGHDRS=$(PNGH) $(PNGCONF) pngusr.h
+PNGOBJS=png$(O) pngerror$(O) pngget$(O) pngmem$(O) \
+        pngread$(O) pngrio$(O) pngrtran$(O) pngrutil$(O) \
+        pngset$(O) pngtrans$(O)
+PROGSRCS= pngm2pnm$(C)
+PROGHDRS=
+PROGDOCS=
+PROGOBJS= pngm2pnm$(O)
+OBJS    = $(PROGOBJS) $(PNGOBJS) $(ZOBJS)
+# implicit make rules -------------------------------------------------------
+# note: dependencies do not work on implicit rule lines
+.c$(O):
+        $(CC) -c $(CFLAGS) $<
+# dependencies
+all: pngm2pnm$(E)
+pngm2pnm$(E): $(OBJS)
+        $(LD) -o pngm2pnm$(E) $(OBJS)
+# The DFA_XTRA setting turns all libpng options off then
+# turns on those required for this minimal build.
+# The CPP_FLAGS setting causes pngusr.h to be included in
+# both the build of pnglibconf.h and, subsequently, when
+# building libpng itself.
+$(PNGCONF): $(PNGSRC)/scripts/pnglibconf.mak\
+        $(PNGSRC)/scripts/pnglibconf.dfa \
+        $(PNGSRC)/scripts/options.awk pngusr.h pngusr.dfa
+        $(RM) pnglibconf.h pnglibconf.dfn
+        $(MAKE) $(MAKEFLAGS) -f $(PNGSRC)/scripts/pnglibconf.mak\
+            srcdir=$(PNGSRC) CPPFLAGS="-DPNG_USER_CONFIG"\
+            DFA_XTRA="pngusr.dfa" $@
+clean:
+        $(MAKE) $(MAKEFLAGS) -f $(PNGSRC)/scripts/pnglibconf.mak\
+            srcdir=$(PNGSRC) clean
+        $(RM) pngm2pnm$(O)
+        $(RM) pngm2pnm$(E)
+        $(RM) $(OBJS)
+# distclean also removes the copied source and headers
+distclean: clean
+        $(RM) -r scripts # historical reasons
+        $(RM) $(PNGSRCS) $(PNGH)
+        $(RM) $(ZSRCS) $(ZH) $(ZCONF)
+        $(RM) $(PROGSRCS) $(PROGHDRS) $(PROGDOCS)
+# Header file dependencies:
+$(PROGOBJS): $(PROGHDRS) $(PNGINC) $(ZINC)
+$(PNGOBJS): $(PNGHDRS) $(ZINC)
+$(ZOBJS): $(ZHDRS)
+# Gather the source code from the respective directories
+$(PNGSRCS) $(PNGH): $(PNGSRC)/$@
+        $(RM) $@
+        $(COPY) $(PNGSRC)/$@ $@
+# No dependency on the ZLIBSRC target so that it only needs
+# to be specified once.
+$(ZSRCS) $(ZH):
+        $(RM) $@
+        $(COPY) $(ZLIBSRC)/$@ $@
+# The unconfigured zconf.h varies in name according to the
+# zlib release
+$(ZCONF):
+        $(RM) $@
+        @for f in zconf.h.in zconf.in.h zconf.h; do\
+            test -r $(ZLIBSRC)/$$f &&\
+            echo $(COPY) $(ZLIBSRC)/$$f $@ &&\
+            $(COPY) $(ZLIBSRC)/$$f $@ && exit 0;\
+        done; echo copy: $(ZLIBSRC)/zconf.h not found; exit 1
+pngm2pnm.c: $(PROGSRC)/png2pnm.c
+        $(RM) $@
+        $(COPY) $(PROGSRC)/png2pnm.c $@
+# End of makefile for pngm2pnm
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminim/decoder/pngusr.dfa b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminim/decoder/pngusr.dfa
new file mode 100644
index 0000000..8a66d64
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminim/decoder/pngusr.dfa
@@ -0,0 +1,39 @@
+# pngminim/decoder/pngusr.dfa
+#
+# Copyright (c) 2010-2011 Glenn Randers-Pehrson
+#
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+# First all the build options off:
+everything = off
+# All that is required is some read code. This example switches
+# on the sequential read code (see ../preader for a progressive
+# read example).
+option SEQUENTIAL_READ on
+# You must choose fixed or floating point arithmetic:
+# option FLOATING_POINT on
+option FIXED_POINT on
+# You must chose the internal fixed point implementation or to
+# use the system floating point.  The latter is considerably
+# smaller (by about 1kbyte on an x86 system):
+# option FLOATING_ARITHMETIC on
+option FLOATING_ARITHMETIC off
+# Your program will probably need other options.  The example
+# program here, pngm2pnm, requires the following.  Take a look
+# at pnglibconf.h to find out the full set of what has to be
+# enabled to make the following work.
+option SETJMP on
+option STDIO on
+option READ_EXPAND on
+option READ_STRIP_16_TO_8 on
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminim/decoder/pngusr.h b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminim/decoder/pngusr.h
new file mode 100644
index 0000000..2991c17
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminim/decoder/pngusr.h
@@ -0,0 +1,24 @@
+/* minrdpngconf.h: headers to make a minimal png-read-only library
+ *
+ * Copyright (c) 2007, 2010-2011 Glenn Randers-Pehrson
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * Derived from pngcrush.h, Copyright 1998-2007, Glenn Randers-Pehrson
+ */
+#ifndef MINRDPNGCONF_H
+#define MINRDPNGCONF_H
+/* To include pngusr.h set -DPNG_USER_CONFIG in CPPFLAGS */
+/* List options to turn off features of the build that do not
+ * affect the API (so are not recorded in pnglibconf.h)
+ */
+#define PNG_NO_WARNINGS
+#define PNG_ALIGN_TYPE PNG_ALIGN_NONE
+#endif /* MINRDPNGCONF_H */
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminim/encoder/README b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminim/encoder/README
new file mode 100644
index 0000000..f8a8b6d
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminim/encoder/README
@@ -0,0 +1,10 @@
+This demonstrates the use of PNG_USER_CONFIG and pngusr.h
+The makefile builds a minimal write-only decoder with embedded libpng
+and zlib.
+Specify the location of the zlib source (1.2.1 or later) as ZLIBSRC
+on the make command line.
+If you prefer to use the shared libraries, go to contrib/pngminus
+and build the pnm2png application there.
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminim/encoder/makefile b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminim/encoder/makefile
new file mode 100644
index 0000000..7374a6c
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminim/encoder/makefile
@@ -0,0 +1,149 @@
+# Makefile for PngMinus (pnm2pngm)
+# Linux / Unix
+#CC=cc
+CC=gcc
+LD=$(CC)
+# If awk fails try
+# make AWK=nawk
+# If cpp fails try
+# make CPP=/lib/cpp
+RM=rm -f
+COPY=cp
+CFLAGS=-DPNG_USER_CONFIG -DNO_GZIP -I. -O1
+C=.c
+O=.o
+L=.a
+E=
+# Where to find the source code:
+PNGSRC =../../..
+ZLIBSRC=$(PNGSRC)/../zlib
+PROGSRC=$(PNGSRC)/contrib/pngminus
+# Zlib
+ZSRCS  = adler32$(C) compress$(C) crc32$(C) deflate$(C) \
+         trees$(C) zutil$(C)
+# Standard headers
+#ZH     = zlib.h crc32.h deflate.h trees.h zutil.h
+ZH     = zlib.h crc32.h deflate.h trees.h zutil.h
+# Machine generated headers
+ZCONF  = zconf.h
+# Headers callers use
+ZINC   = zlib.h $(ZCONF)
+# Headers the Zlib source uses
+ZHDRS  = $(ZH) $(ZCONF)
+# compress is not required; it is needed to link the zlib
+# code because deflate defines an unused API function deflateBound
+# which itself calls compressBound from compress.
+ZOBJS  = adler32$(O) compress$(O) crc32$(O) deflate$(O) \
+         trees$(O) zutil$(O)
+# libpng
+PNGSRCS=png$(C) pngerror$(C) pngget$(C) pngmem$(C) \
+        pngset$(C) pngtrans$(C) pngwio$(C) pngwrite$(C) \
+        pngwtran$(C) pngwutil$(C)
+# Standard headers
+PNGH   =png.h pngconf.h pngdebug.h pnginfo.h pngpriv.h pngstruct.h
+# Machine generated headers
+PNGCONF=pnglibconf.h
+# Headers callers use
+PNGINC= png.h pngconf.h pngusr.h $(PNGCONF)
+# Headers the PNG library uses
+PNGHDRS=$(PNGH) $(PNGCONF) pngusr.h
+PNGOBJS=png$(O) pngerror$(O) pngget$(O) pngmem$(O) \
+        pngset$(O) pngtrans$(O) pngwio$(O) pngwrite$(O) \
+        pngwtran$(O) pngwutil$(O)
+PROGSRCS= pnm2pngm$(C)
+PROGHDRS=
+PROGDOCS=
+PROGOBJS= pnm2pngm$(O)
+OBJS    = $(PROGOBJS) $(PNGOBJS) $(ZOBJS)
+# implicit make rules -------------------------------------------------------
+.c$(O):
+        $(CC) -c $(CFLAGS) $<
+# dependencies
+all: pnm2pngm$(E)
+pnm2pngm$(E): $(OBJS)
+        $(LD) -o pnm2pngm$(E) $(OBJS)
+# The DFA_XTRA setting turns all libpng options off then
+# turns on those required for this minimal build.
+# The CPP_FLAGS setting causes pngusr.h to be included in
+# both the build of pnglibconf.h and, subsequently, when
+# building libpng itself.
+$(PNGCONF): $(PNGSRC)/scripts/pnglibconf.mak\
+        $(PNGSRC)/scripts/pnglibconf.dfa \
+        $(PNGSRC)/scripts/options.awk pngusr.h pngusr.dfa
+        $(RM) pnglibconf.h pnglibconf.dfn
+        $(MAKE) $(MAKEFLAGS) -f $(PNGSRC)/scripts/pnglibconf.mak\
+            srcdir=$(PNGSRC) CPPFLAGS="-DPNG_USER_CONFIG"\
+            DFA_XTRA="pngusr.dfa" $@
+clean:
+        $(MAKE) $(MAKEFLAGS) -f $(PNGSRC)/scripts/pnglibconf.mak\
+            srcdir=$(PNGSRC) clean
+        $(RM) pnm2pngm$(O)
+        $(RM) pnm2pngm$(E)
+        $(RM) $(OBJS)
+# distclean also removes the copied source and headers
+distclean: clean
+        $(RM) -r scripts # historical reasons
+        $(RM) $(PNGSRCS) $(PNGH)
+        $(RM) $(ZSRCS) $(ZH) $(ZCONF)
+        $(RM) $(PROGSRCS) $(PROGHDRS) $(PROGDOCS)
+# Header file dependencies:
+$(PROGOBJS): $(PROGHDRS) $(PNGINC) $(ZINC)
+$(PNGOBJS): $(PNGHDRS) $(ZINC)
+$(ZOBJS): $(ZHDRS)
+# Gather the source code from the respective directories
+$(PNGSRCS) $(PNGH): $(PNGSRC)/$@
+        $(RM) $@
+        $(COPY) $(PNGSRC)/$@ $@
+# No dependency on the ZLIBSRC target so that it only needs
+# to be specified once.
+$(ZSRCS) $(ZH):
+        $(RM) $@
+        $(COPY) $(ZLIBSRC)/$@ $@
+# The unconfigured zconf.h varies in name according to the
+# zlib release
+$(ZCONF):
+        $(RM) $@
+        @for f in zconf.h.in zconf.in.h zconf.h; do\
+            test -r $(ZLIBSRC)/$$f &&\
+            echo $(COPY) $(ZLIBSRC)/$$f $@ &&\
+            $(COPY) $(ZLIBSRC)/$$f $@ && exit 0;\
+        done; echo copy: $(ZLIBSRC)/zconf.h not found; exit 1
+pnm2pngm.c: $(PROGSRC)/pnm2png.c
+        $(RM) $@
+        $(COPY) $(PROGSRC)/pnm2png.c $@
+# End of makefile for pnm2pngm
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminim/encoder/pngusr.dfa b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminim/encoder/pngusr.dfa
new file mode 100644
index 0000000..448f821
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminim/encoder/pngusr.dfa
@@ -0,0 +1,35 @@
+# pngminim/encoder/pngusr.dfa
+#
+# Copyright (c) 2010-2011 Glenn Randers-Pehrson
+#
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+# First all the build options off:
+everything = off
+# Switch on the write code - this makes a minimalist encoder
+option WRITE on
+# You must choose fixed or floating point arithmetic:
+# option FLOATING_POINT on
+option FIXED_POINT on
+# You must chose the internal fixed point implementation or to
+# use the system floating point.  The latter is considerably
+# smaller (by about 1kbyte on an x86 system):
+# option FLOATING_ARITHMETIC on
+option FLOATING_ARITHMETIC off
+# Your program will probably need other options.  The example
+# program here, pnm2pngm, requires the following.  Take a look
+# at pnglibconf.h to find out the full set of what has to be
+# enabled to make the following work.
+option SETJMP on
+option STDIO on
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminim/encoder/pngusr.h b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminim/encoder/pngusr.h
new file mode 100644
index 0000000..bafbf13
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminim/encoder/pngusr.h
@@ -0,0 +1,24 @@
+/* minwrpngconf.h: headers to make a minimal png-write-only library
+ *
+ * Copyright (c) 2007, 2010-2011 Glenn Randers-Pehrson
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * Derived from pngcrush.h, Copyright 1998-2007, Glenn Randers-Pehrson
+ */
+#ifndef MINWRPNGCONF_H
+#define MINWRPNGCONF_H
+/* To include pngusr.h set -DPNG_USER_CONFIG in CPPFLAGS */
+/* List options to turn off features of the build that do not
+ * affect the API (so are not recorded in pnglibconf.h)
+ */
+#define PNG_NO_WARNINGS
+#define PNG_ALIGN_TYPE PNG_ALIGN_NONE
+#endif /* MINWRPNGCONF_H */
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminim/preader/README b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminim/preader/README
new file mode 100644
index 0000000..e40024e
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminim/preader/README
@@ -0,0 +1,15 @@
+This demonstrates the use of PNG_USER_CONFIG and pngusr.h
+The makefile builds a minimal read-only progressive decoder with
+embedded libpng, zlib and your system's X library.
+Specify the location of the zlib source (1.2.1 or later) as ZLIBSRC
+on the make command line.
+Edit makefile if required, to find your X library and include files,
+then
+    make ZLIBSRC=directory
+If you prefer to use the shared libraries, go to contrib/gregbook
+and build the rpng2-x application there.
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminim/preader/makefile b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminim/preader/makefile
new file mode 100644
index 0000000..a367661
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminim/preader/makefile
@@ -0,0 +1,165 @@
+# Makefile for PngMinus (rpng2)
+# Linux / Unix
+#CC=cc
+CC=gcc
+LD=$(CC)
+# If awk fails try
+# make AWK=nawk
+# If cpp fails try
+# make CPP=/lib/cpp
+RM=rm -f
+COPY=cp
+#XINC = -I/usr/include                  # old-style, stock X distributions
+#XLIB = -L/usr/lib/X11 -lX11            #  (including SGI IRIX)
+#XINC = -I/usr/openwin/include          # Sun workstations (OpenWindows)
+#XLIB = -L/usr/openwin/lib -lX11
+XINC = -I/usr/X11R6/include             # new X distributions (X.org, etc.)
+XLIB = -L/usr/X11R6/lib -lX11
+#XLIB = -L/usr/X11R6/lib64 -lX11        # e.g., Red Hat on AMD64
+#XINC = -I/usr/local/include            # FreeBSD
+#XLIB = -L/usr/local/lib -lX11
+#LIBS = $(XLIB)
+LIBS = $(XLIB) -lm                      #platforms that need libm
+CFLAGS=-DPNG_USER_CONFIG -DNO_GZCOMPRESS -DNO_GZIP -I. $(XINC) -O1
+C=.c
+O=.o
+L=.a
+E=
+# Where to find the source code:
+PNGSRC =../../..
+ZLIBSRC=$(PNGSRC)/../zlib
+PROGSRC=$(PNGSRC)/contrib/gregbook
+# Zlib (minimal inflate requirements - crc32 is used by libpng)
+# zutil can be eliminated if you provide your own zcalloc and zcfree
+ZSRCS  = adler32$(C) crc32$(C) \
+         inffast$(C) inflate$(C) inftrees$(C) \
+         zutil$(C)
+# Standard headers
+ZH     = zlib.h crc32.h inffast.h inffixed.h \
+         inflate.h inftrees.h zutil.h
+# Machine generated headers
+ZCONF  = zconf.h
+# Headers callers use
+ZINC   = zlib.h $(ZCONF)
+# Headers the Zlib source uses
+ZHDRS  = $(ZH) $(ZCONF)
+ZOBJS  = adler32$(O) crc32$(O) \
+         inffast$(O) inflate$(O) inftrees$(O) \
+         zutil$(O)
+# libpng
+PNGSRCS=png$(C) pngerror$(C) pngget$(C) pngmem$(C) \
+        pngpread$(C) pngread$(C) pngrio$(C) pngrtran$(C) pngrutil$(C) \
+        pngset$(C) pngtrans$(C)
+# Standard headers
+PNGH   =png.h pngconf.h pngdebug.h pnginfo.h pngpriv.h pngstruct.h
+# Machine generated headers
+PNGCONF=pnglibconf.h
+# Headers callers use
+PNGINC= png.h pngconf.h pngusr.h $(PNGCONF)
+# Headers the PNG library uses
+PNGHDRS=$(PNGH) $(PNGCONF) pngusr.h
+PNGOBJS=png$(O) pngerror$(O) pngget$(O) pngmem$(O) \
+        pngpread$(O) pngread$(O) pngrio$(O) pngrtran$(O) pngrutil$(O) \
+        pngset$(O) pngtrans$(O)
+PROGSRCS= rpng2-x$(C) readpng2$(C)
+PROGHDRS= readpng2.h
+PROGDOCS= COPYING LICENSE
+PROGOBJS= rpng2-x$(O) readpng2$(O)
+OBJS    = $(PROGOBJS) $(PNGOBJS) $(ZOBJS)
+# implicit make rules -------------------------------------------------------
+.c$(O):
+        $(CC) -c $(CFLAGS) $<
+# dependencies
+all: $(PROGDOCS) rpng2-x$(E)
+rpng2-x$(E): $(OBJS)
+        $(LD) -o rpng2-x$(E) $(OBJS) $(LIBS)
+# The DFA_XTRA setting turns all libpng options off then
+# turns on those required for this minimal build.
+# The CPP_FLAGS setting causes pngusr.h to be included in
+# both the build of pnglibconf.h and, subsequently, when
+# building libpng itself.
+$(PNGCONF): $(PNGSRC)/scripts/pnglibconf.mak\
+        $(PNGSRC)/scripts/pnglibconf.dfa \
+        $(PNGSRC)/scripts/options.awk pngusr.h pngusr.dfa
+        $(RM) pnglibconf.h pnglibconf.dfn
+        $(MAKE) $(MAKEFLAGS) -f $(PNGSRC)/scripts/pnglibconf.mak\
+            srcdir=$(PNGSRC) CPPFLAGS="-DPNG_USER_CONFIG"\
+            DFA_XTRA="pngusr.dfa" $@
+clean:
+        $(MAKE) $(MAKEFLAGS) -f $(PNGSRC)/scripts/pnglibconf.mak\
+            srcdir=$(PNGSRC) clean
+        $(RM) rpng2-x$(O)
+        $(RM) rpng2-x$(E)
+        $(RM) $(OBJS)
+# distclean also removes the copied source and headers
+distclean: clean
+        $(RM) -r scripts # historical reasons
+        $(RM) $(PNGSRCS) $(PNGH)
+        $(RM) $(ZSRCS) $(ZH) $(ZCONF)
+        $(RM) $(PROGSRCS) $(PROGHDRS) $(PROGDOCS)
+# Header file dependencies:
+$(PROGOBJS): $(PROGHDRS) $(PNGINC) $(ZINC)
+$(PNGOBJS): $(PNGHDRS) $(ZINC)
+$(ZOBJS): $(ZHDRS)
+# Gather the source code from the respective directories
+$(PNGSRCS) $(PNGH): $(PNGSRC)/$@
+        $(RM) $@
+        $(COPY) $(PNGSRC)/$@ $@
+# No dependency on the ZLIBSRC target so that it only needs
+# to be specified once.
+$(ZSRCS) $(ZH):
+        $(RM) $@
+        $(COPY) $(ZLIBSRC)/$@ $@
+# The unconfigured zconf.h varies in name according to the
+# zlib release
+$(ZCONF):
+        $(RM) $@
+        @for f in zconf.h.in zconf.in.h zconf.h; do\
+            test -r $(ZLIBSRC)/$$f &&\
+            echo $(COPY) $(ZLIBSRC)/$$f $@ &&\
+            $(COPY) $(ZLIBSRC)/$$f $@ && exit 0;\
+        done; echo copy: $(ZLIBSRC)/zconf.h not found; exit 1
+$(PROGSRCS) $(PROGHDRS) $(PROGDOCS): $(PROGSRC)/$@
+        $(RM) $@
+        $(COPY) $(PROGSRC)/$@ $@
+# End of makefile for rpng2-x
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminim/preader/pngusr.dfa b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminim/preader/pngusr.dfa
new file mode 100644
index 0000000..0c991d3
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminim/preader/pngusr.dfa
@@ -0,0 +1,40 @@
+# pngminim/preader/pngusr.dfa
+#
+# Copyright (c) 2010-2011 Glenn Randers-Pehrson
+#
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+# First all the build options off:
+everything = off
+# Just switch on the progressive read code
+option PROGRESSIVE_READ on
+# You may choose fixed or floating point APIs:
+# option FLOATING_POINT on
+option FIXED_POINT on
+# You must chose the internal fixed point implementation or to
+# use the system floating point.  The latter is considerably
+# smaller (by about 1kbyte on an x86 system):
+option FLOATING_ARITHMETIC on
+# option FLOATING_ARITHMETIC off
+# Your program will probably need other options.  The example
+# program here, rpng2-x, requires the following.  Take a look
+# at pnglibconf.h to find out the full set of what has to be
+# enabled to make the following work.
+option SETJMP on
+option STDIO on
+option READ_bKGD on
+option READ_GAMMA on
+option READ_EXPAND on
+option READ_STRIP_16_TO_8 on
+option READ_GRAY_TO_RGB on
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminim/preader/pngusr.h b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminim/preader/pngusr.h
new file mode 100644
index 0000000..7db806f
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminim/preader/pngusr.h
@@ -0,0 +1,24 @@
+/* minrdpngconf.h: headers to make a minimal png-read-only library
+ *
+ * Copyright (c) 2009, 2010-2011 Glenn Randers-Pehrson
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * Derived from pngcrush.h, Copyright 1998-2007, Glenn Randers-Pehrson
+ */
+#ifndef MINPRDPNGCONF_H
+#define MINPRDPNGCONF_H
+/* To include pngusr.h set -DPNG_USER_CONFIG in CPPFLAGS */
+/* List options to turn off features of the build that do not
+ * affect the API (so are not recorded in pnglibconf.h)
+ */
+#define PNG_NO_WARNINGS
+#define PNG_ALIGN_TYPE PNG_ALIGN_NONE
+#endif /* MINPRDPNGCONF_H */
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminus/README b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminus/README
new file mode 100644
index 0000000..b0516ec
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminus/README
@@ -0,0 +1,153 @@
+PngMinus
+--------
+(copyright Willem van Schaik, 1999)
+License
+-------
+Permission to use, copy, modify, and distribute this software and
+its documentation for any purpose and without fee is hereby granted,
+provided that the above copyright notice appear in all copies and
+that both that copyright notice and this permission notice appear in
+supporting documentation. This software is provided "as is" without
+express or implied warranty.
+Some history
+------------
+Soon after the creation of PNG in 1995, the need was felt for a set of
+pnmtopng / pngtopnm utilities. Independantly Alexander Lehmann and I
+(Willem van Schaik) started such a project. Luckily we discovered this
+and merged the two together into pnmtopng.tar.gz, which is available
+from a/o ftp://ftp.simplesystems.org/pub/libpng/png/.
+These two utilities have many, many options and make use of most of the
+features of PNG, like gamma, alpha, sbit, text-chunks, etc. This makes
+the utilities quite complex and by now not anymore very maintainable.
+When we wrote these programs, libpng was still in an early stage.
+Therefore, lots of the functionality that we put in our software can now
+be done using transform-functions in libpng.
+Finally, to compile these programs, you need to have installed and
+compiled three libraries: libpng, zlib and netpbm. Especially the latter
+makes the whole setup a bit bulky. But that's unavoidable given the many
+features of pnmtopng.
+What now
+--------
+At this moment libpng is in a very stable state and can do much of the
+work done in pnmtopng. Also, pnmtopng needs to be upgraded to the new
+interface of libpng. Hence, it is time for a rewrite from the ground up
+of pnmtopng and pngtopnm. This will happen in the near future (stay
+tuned). The new package will get a different name to distinguish it from
+the old one: PngPlus.
+To experiment a bit with the new interface of libpng, I started off with
+a small prototype that contains only the basic functionality. It doesn't
+have any of the options to read or write special chunks and it will do
+no gamma correction. But this makes it also a simple program that is
+quite easy to understand and can serve well as a template for other
+software developments. (By now there are of course a couple of programs,
+like Greg Roelofs' rpng/wpng, that can be used just as good.)
+Can and can not
+---------------
+As this is the small brother of the future PngPlus, I called this fellow
+PngMinus. Because I started this development in good-old Turbo-C, I
+avoided the use the netpbm library, which requires DOS extenders. Again,
+another reason to call it PngMinus (minus netpbm :-). So, part of the
+program are some elementary routines to read / write pgm- and ppm-files.
+It does not read b&w pbm-files.
+The downside of this approach is that you can not use them on images
+that require blocks of memory bigger than 64k (the DOS version). For
+larger images you will get an out-of-memory error.
+As said before, PngMinus doesn't correct for gamma. When reading
+png-files you can do this just as well by piping the output of png2pnm
+to pnmgamma, one of the standard PbmPlus tools. This same scenario will
+most probably also be followed in the full-blown future PngPlus, with
+the addition of course of the possibility to create gamma-chunks when
+writing png-files.
+On the other hand it supports alpha-channels. When reading a png-image
+you can write the alpha-channel into a pgm-file. And when creating an
+RGB+A png-image, you just combine a ppm-file with a corresponding
+pgm-file containing the alpha-channel. When reading, transparency chunks
+are converted into an alpha-channel and from there on treated the same
+way.
+Finally you can opt for writing ascii or binary pgm- and ppm-files. When
+the bit-depth is 16, the format will always be ascii.
+Using it
+--------
+To distinguish them from pnmtopng and PngPlus, the utilities are named
+png2pnm and pnm2png (2 instead of to). The input- and output-files can
+be given as parameters or through redirection. Therefore the programs
+can be part of a pipe.
+To list the options type "png2pnm -h" or "pnm2png -h".
+Just like Scandinavian furniture
+--------------------------------
+You have to put it together yourself. I did test the software under
+MS-DOS with Turbo-C 3.0 and under RedHat Linux 4.2 with gcc. In both
+cases I used libpng-1.0.4 and zlib-1.1.3. Later versions should be OK,
+however some older libpng versions have a bug in pngmem.c when using
+Turbo-C 3.0 (see below).
+You can build it using one of the two makefiles (make -f makefile.###)
+or use the batch/script files pngminus.bat / pngminus.sh. This assumes
+that you have built the libraries in ../libpng and ../zlib. Using Linux,
+make sure that you have built libpng with makefile.std and not
+makefile.linux (also called .lnx in earlier versions of libpng). The
+latter creates a .so shared-library, while the PngMinus makefile assumes
+a normal .a static library.
+If you create a ../pngsuite directory and then store the basn####.png
+files from PngSuite (http://www.schaik.com/pngsuite/) in there, you can
+test in one go the proper functioning of PngMinus, see png2pnm.bat and
+pnm2png.bat (or the .sh versions).
+Warranty
+-------
+Please, remember that this was just a small experiment to learn a few
+things. It will have many unforeseen features <vbg>. Who said bugs? Use
+it when you are in need for something simple or when you want to start
+developing your own stuff.
+The Turbo bug
+-------------
+** pngmem.old
+          hptr = (png_byte huge *)((long)(hptr) & 0xfffffff0L);
+          hptr += 16L;
+** pngmem.c
+          hptr = (png_byte huge *)((long)(hptr) & 0xfffffff0L);
+          hptr = hptr + 16L;
+**
+** pngmem.old
+          png_ptr->offset_table_ptr[i] = (png_bytep)hptr;
+          hptr += (png_uint_32)65536L;
+** pngmem.c
+          png_ptr->offset_table_ptr[i] = (png_bytep)hptr;
+          hptr = hptr + 65536L;
+**
+The end
+-------
+Willem van Schaik
+mailto:willem@schaik.com
+http://www.schaik.com/png/
+-------
+Oct 1999
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminus/makefile.std b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminus/makefile.std
new file mode 100644
index 0000000..a121032
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminus/makefile.std
@@ -0,0 +1,65 @@
+# Makefile for PngMinus (png2pnm and pnm2png)
+# Linux / Unix
+#CC=cc
+CC=gcc
+LD=$(CC)
+RM=rm -f
+#PNGPATH = /usr/local
+#PNGINC = -I$(PNGPATH)/include/libpng15
+#PNGLIB = -L$(PNGPATH)/lib -lpng15
+#PNGLIBS = $(PNGPATH)/lib/libpng15.a
+PNGINC = -I../..
+PNGLIB = -L../.. -lpng
+PNGLIBS = ../../libpng.a
+#ZPATH = /usr/local
+#ZINC = -I$(ZPATH)/include
+#ZLIB = -L$(ZPATH)/lib -lz
+#ZLIBS = $(ZPATH)/lib/libz.a
+ZINC = -I../../../zlib
+ZLIB = -L../../../zlib -lz
+ZLIBS = ../../../zlib/libz.a
+CFLAGS=$(PNGINC) $(ZINC)
+LDLIBS=$(PNGLIB) $(ZLIB)
+LDLIBSS=$(PNGLIBS) $(ZLIBS)
+C=.c
+O=.o
+L=.a
+E=
+# dependencies
+#all: png2pnm$(E) pnm2png$(E)
+all: png2pnm$(E) pnm2png$(E) png2pnm-static$(E) pnm2png-static$(E)
+png2pnm$(O): png2pnm$(C)
+        $(CC) -c $(CFLAGS) png2pnm$(C)
+png2pnm$(E): png2pnm$(O)
+        $(LD) $(LDFLAGS) -o png2pnm$(E) png2pnm$(O) $(LDLIBS) -lm
+png2pnm-static$(E): png2pnm$(O)
+        $(LD) $(LDFLAGS) -o png2pnm-static$(E) png2pnm$(O) $(LDLIBSS) -lm
+pnm2png$(O): pnm2png$(C)
+        $(CC) -c $(CFLAGS) pnm2png$(C)
+pnm2png$(E): pnm2png$(O)
+        $(LD) $(LDFLAGS) -o pnm2png$(E) pnm2png$(O) $(LDLIBS) -lm
+pnm2png-static$(E): pnm2png$(O)
+        $(LD) $(LDFLAGS) -o pnm2png-static$(E) pnm2png$(O) $(LDLIBSS) -lm
+clean:
+        $(RM) png2pnm$(O)
+        $(RM) pnm2png$(O)
+        $(RM) png2pnm$(E)
+        $(RM) pnm2png$(E)
+        $(RM) png2pnm-static$(E)
+        $(RM) pnm2png-static$(E)
+# End of makefile for png2pnm / pnm2png
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminus/makefile.tc3 b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminus/makefile.tc3
new file mode 100644
index 0000000..01062cc
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminus/makefile.tc3
@@ -0,0 +1,38 @@
+# Makefile for PngMinus (png2pnm and pnm2png)
+# TurboC++ 3.0
+CC=tcc -Ic:\tc3\inc
+LD=tcc -Lc:\tc3\lib
+LB=tlib
+RM=del
+CP=copy
+MODEL=l
+CCFLAGS=-O -m$(MODEL) -I..\libpng -I..\zlib
+LDFLAGS=-m$(MODEL) -L..\libpng -L..\zlib
+C=.c
+O=.obj
+L=.lib
+E=.exe
+# dependencies
+all: png2pnm$(E) pnm2png$(E)
+png2pnm$(O): png2pnm$(C)
+        $(CC) -c $(CCFLAGS) png2pnm$(C)
+png2pnm$(E): png2pnm$(O)
+        $(LD) $(LDFLAGS) png2pnm$(O) libpng$(L) zlib$(L)
+pnm2png$(O): pnm2png$(C)
+        $(CC) -c $(CCFLAGS) pnm2png$(C)
+pnm2png$(E): pnm2png$(O)
+        $(LD) $(LDFLAGS) pnm2png$(O) libpng$(L) zlib$(L)
+clean:
+        $(RM) *$(O)
+        $(RM) *$(E)
+# End of makefile for png2pnm / pnm2png
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminus/makevms.com b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminus/makevms.com
new file mode 100644
index 0000000..96c3147
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminus/makevms.com
@@ -0,0 +1,92 @@
+$!------------------------------------------------------------------------------
+$! make Contrib programs of libpng under OpenVMS
+$!
+$!
+$! Look for the compiler used
+$!
+$ zlibsrc = "[---.zlib]"
+$ ccopt="/include=(''zlibsrc',[--])"
+$ if f$getsyi("HW_MODEL").ge.1024
+$ then
+$  ccopt = "/prefix=all"+ccopt
+$  comp  = "__decc__=1"
+$  if f$trnlnm("SYS").eqs."" then define sys sys$library:
+$ else
+$  if f$search("SYS$SYSTEM:DECC$COMPILER.EXE").eqs.""
+$   then
+$    if f$trnlnm("SYS").eqs."" then define sys sys$library:
+$    if f$search("SYS$SYSTEM:VAXC.EXE").eqs.""
+$     then
+$      comp  = "__gcc__=1"
+$      CC :== GCC
+$     else
+$      comp = "__vaxc__=1"
+$     endif
+$   else
+$    if f$trnlnm("SYS").eqs."" then define sys decc$library_include:
+$    ccopt = "/decc/prefix=all"+ccopt
+$    comp  = "__decc__=1"
+$  endif
+$ endif
+$ open/write lopt lib.opt
+$ write lopt "[--]libpng.olb/lib"
+$ write lopt "''zlibsrc'libz.olb/lib"
+$ close lopt
+$ open/write xopt x11.opt
+$ write xopt "sys$library:decw$xlibshr.exe/share"
+$ close xopt
+$ write sys$output "Compiling PNG contrib programs ..."
+$   write sys$output "Building pnm2png..."
+$   CALL MAKE pnm2png.OBJ "cc ''CCOPT' pnm2png" -
+        pnm2png.c
+$   call make pnm2png.exe -
+        "LINK pnm2png,lib.opt/opt" -
+        pnm2png.obj
+$   write sys$output "Building png2pnm..."
+$   CALL MAKE png2pnm.OBJ "cc ''CCOPT' png2pnm" -
+        png2pnm.c
+$   call make png2pnm.exe -
+        "LINK png2pnm,lib.opt/opt" -
+        png2pnm.obj
+$ exit
+$!
+$!
+$MAKE: SUBROUTINE   !SUBROUTINE TO CHECK DEPENDENCIES
+$ V = 'F$Verify(0)
+$! P1 = What we are trying to make
+$! P2 = Command to make it
+$! P3 - P8  What it depends on
+$
+$ If F$Search(P1) .Eqs. "" Then Goto Makeit
+$ Time = F$CvTime(F$File(P1,"RDT"))
+$arg=3
+$Loop:
+$       Argument = P'arg
+$       If Argument .Eqs. "" Then Goto Exit
+$       El=0
+$Loop2:
+$       File = F$Element(El," ",Argument)
+$       If File .Eqs. " " Then Goto Endl
+$       AFile = ""
+$Loop3:
+$       OFile = AFile
+$       AFile = F$Search(File)
+$       If AFile .Eqs. "" .Or. AFile .Eqs. OFile Then Goto NextEl
+$       If F$CvTime(F$File(AFile,"RDT")) .Ges. Time Then Goto Makeit
+$       Goto Loop3
+$NextEL:
+$       El = El + 1
+$       Goto Loop2
+$EndL:
+$ arg=arg+1
+$ If arg .Le. 8 Then Goto Loop
+$ Goto Exit
+$
+$Makeit:
+$ VV=F$VERIFY(0)
+$ write sys$output P2
+$ 'P2
+$ VV='F$Verify(VV)
+$Exit:
+$ If V Then Set Verify
+$ENDSUBROUTINE
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminus/png2pnm.bat b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminus/png2pnm.bat
new file mode 100644
index 0000000..85abe3c
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminus/png2pnm.bat
@@ -0,0 +1,41 @@
+REM -- grayscale
+png2pnm.exe -noraw ..\pngsuite\basn0g01.png basn0g01.pgm
+png2pnm.exe -noraw ..\pngsuite\basn0g02.png basn0g02.pgm
+png2pnm.exe -noraw ..\pngsuite\basn0g04.png basn0g04.pgm
+png2pnm.exe -noraw ..\pngsuite\basn0g08.png basn0g08.pgm
+png2pnm.exe -noraw ..\pngsuite\basn0g16.png basn0g16.pgm
+REM -- full-color
+png2pnm.exe -noraw ..\pngsuite\basn2c08.png basn2c08.ppm
+png2pnm.exe -noraw ..\pngsuite\basn2c16.png basn2c16.ppm
+REM -- palletted
+png2pnm.exe -noraw ..\pngsuite\basn3p01.png basn3p01.ppm
+png2pnm.exe -noraw ..\pngsuite\basn3p02.png basn3p02.ppm
+png2pnm.exe -noraw ..\pngsuite\basn3p04.png basn3p04.ppm
+png2pnm.exe -noraw ..\pngsuite\basn3p08.png basn3p08.ppm
+REM -- gray with alpha-channel
+png2pnm.exe -noraw ..\pngsuite\basn4a08.png basn4a08.pgm
+png2pnm.exe -noraw ..\pngsuite\basn4a16.png basn4a16.pgm
+REM -- color with alpha-channel
+png2pnm.exe -noraw -alpha basn6a08.pgm ..\pngsuite\basn6a08.png basn6a08.ppm
+png2pnm.exe -noraw -alpha basn6a16.pgm ..\pngsuite\basn6a16.png basn6a16.ppm
+REM -- grayscale
+png2pnm.exe -raw ..\pngsuite\basn0g01.png rawn0g01.pgm
+png2pnm.exe -raw ..\pngsuite\basn0g02.png rawn0g02.pgm
+png2pnm.exe -raw ..\pngsuite\basn0g04.png rawn0g04.pgm
+png2pnm.exe -raw ..\pngsuite\basn0g08.png rawn0g08.pgm
+png2pnm.exe -raw ..\pngsuite\basn0g16.png rawn0g16.pgm
+REM -- full-color
+png2pnm.exe -raw ..\pngsuite\basn2c08.png rawn2c08.ppm
+png2pnm.exe -raw ..\pngsuite\basn2c16.png rawn2c16.ppm
+REM -- palletted
+png2pnm.exe -raw ..\pngsuite\basn3p01.png rawn3p01.ppm
+png2pnm.exe -raw ..\pngsuite\basn3p02.png rawn3p02.ppm
+png2pnm.exe -raw ..\pngsuite\basn3p04.png rawn3p04.ppm
+png2pnm.exe -raw ..\pngsuite\basn3p08.png rawn3p08.ppm
+REM -- gray with alpha-channel
+png2pnm.exe -raw ..\pngsuite\basn4a08.png rawn4a08.pgm
+png2pnm.exe -raw ..\pngsuite\basn4a16.png rawn4a16.pgm
+REM -- color with alpha-channel
+png2pnm.exe -noraw -alpha rawn6a08.pgm ..\pngsuite\basn6a08.png rawn6a08.ppm
+png2pnm.exe -noraw -alpha rawn6a16.pgm ..\pngsuite\basn6a16.png rawn6a16.ppm
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminus/png2pnm.c b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminus/png2pnm.c
new file mode 100644
index 0000000..ef28d90
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminus/png2pnm.c
@@ -0,0 +1,430 @@
+/*
+ *  png2pnm.c --- conversion from PNG-file to PGM/PPM-file
+ *  copyright (C) 1999 by Willem van Schaik <willem@schaik.com>
+ *
+ *  version 1.0 - 1999.10.15 - First version.
+ *
+ *  Permission to use, copy, modify, and distribute this software and
+ *  its documentation for any purpose and without fee is hereby granted,
+ *  provided that the above copyright notice appear in all copies and
+ *  that both that copyright notice and this permission notice appear in
+ *  supporting documentation. This software is provided "as is" without
+ *  express or implied warranty.
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#ifdef __TURBOC__
+#include <mem.h>
+#include <fcntl.h>
+#endif
+#ifndef BOOL
+#define BOOL unsigned char
+#endif
+#ifndef TRUE
+#define TRUE (BOOL) 1
+#endif
+#ifndef FALSE
+#define FALSE (BOOL) 0
+#endif
+#ifdef __TURBOC__
+#define STDIN  0
+#define STDOUT 1
+#define STDERR 2
+#endif
+/* to make png2pnm verbose so we can find problems (needs to be before png.h) */
+#ifndef PNG_DEBUG
+#define PNG_DEBUG 0
+#endif
+#include "png.h"
+/* Define png_jmpbuf() in case we are using a pre-1.0.6 version of libpng */
+#ifndef png_jmpbuf
+#  define png_jmpbuf(png_ptr) ((png_ptr)->jmpbuf)
+#endif
+/* function prototypes */
+int  main (int argc, char *argv[]);
+void usage ();
+BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file, BOOL raw, BOOL alpha);
+/*
+ *  main
+ */
+int main(int argc, char *argv[])
+{
+  FILE *fp_rd = stdin;
+  FILE *fp_wr = stdout;
+  FILE *fp_al = NULL;
+  BOOL raw = TRUE;
+  BOOL alpha = FALSE;
+  int argi;
+  for (argi = 1; argi < argc; argi++)
+  {
+    if (argv[argi][0] == '-')
+    {
+      switch (argv[argi][1])
+      {
+        case 'n':
+          raw = FALSE;
+          break;
+        case 'r':
+          raw = TRUE;
+          break;
+        case 'a':
+          alpha = TRUE;
+          argi++;
+          if ((fp_al = fopen (argv[argi], "wb")) == NULL)
+          {
+            fprintf (stderr, "PNM2PNG\n");
+            fprintf (stderr, "Error:  can not create alpha-channel file %s\n", argv[argi]);
+            exit (1);
+          }
+          break;
+        case 'h':
+        case '?':
+          usage();
+          exit(0);
+          break;
+        default:
+          fprintf (stderr, "PNG2PNM\n");
+          fprintf (stderr, "Error:  unknown option %s\n", argv[argi]);
+          usage();
+          exit(1);
+          break;
+      } /* end switch */
+    }
+    else if (fp_rd == stdin)
+    {
+      if ((fp_rd = fopen (argv[argi], "rb")) == NULL)
+      {
+             fprintf (stderr, "PNG2PNM\n");
+            fprintf (stderr, "Error:  file %s does not exist\n", argv[argi]);
+            exit (1);
+      }
+    }
+    else if (fp_wr == stdout)
+    {
+      if ((fp_wr = fopen (argv[argi], "wb")) == NULL)
+      {
+        fprintf (stderr, "PNG2PNM\n");
+        fprintf (stderr, "Error:  can not create file %s\n", argv[argi]);
+        exit (1);
+      }
+    }
+    else
+    {
+      fprintf (stderr, "PNG2PNM\n");
+      fprintf (stderr, "Error:  too many parameters\n");
+      usage();
+      exit(1);
+    }
+  } /* end for */
+#ifdef __TURBOC__
+  /* set stdin/stdout if required to binary */
+  if (fp_rd == stdin)
+  {
+    setmode (STDIN, O_BINARY);
+  }
+  if ((raw) && (fp_wr == stdout))
+  {
+    setmode (STDOUT, O_BINARY);
+  }
+#endif
+  /* call the conversion program itself */
+  if (png2pnm (fp_rd, fp_wr, fp_al, raw, alpha) == FALSE)
+  {
+    fprintf (stderr, "PNG2PNM\n");
+    fprintf (stderr, "Error:  unsuccessful conversion of PNG-image\n");
+    exit(1);
+  }
+  /* close input file */
+  fclose (fp_rd);
+  /* close output file */
+  fclose (fp_wr);
+  /* close alpha file */
+  if (alpha)
+    fclose (fp_al);
+  return 0;
+}
+/*
+ *  usage
+ */
+void usage()
+{
+  fprintf (stderr, "PNG2PNM\n");
+  fprintf (stderr, "   by Willem van Schaik, 1999\n");
+#ifdef __TURBOC__
+  fprintf (stderr, "   for Turbo-C and Borland-C compilers\n");
+#else
+  fprintf (stderr, "   for Linux (and Unix) compilers\n");
+#endif
+  fprintf (stderr, "Usage:  png2pnm [options] <file>.png [<file>.pnm]\n");
+  fprintf (stderr, "   or:  ... | png2pnm [options]\n");
+  fprintf (stderr, "Options:\n");
+  fprintf (stderr, "   -r[aw]   write pnm-file in binary format (P4/P5/P6) (default)\n");
+  fprintf (stderr, "   -n[oraw] write pnm-file in ascii format (P1/P2/P3)\n");
+  fprintf (stderr, "   -a[lpha] <file>.pgm write PNG alpha channel as pgm-file\n");
+  fprintf (stderr, "   -h | -?  print this help-information\n");
+}
+/*
+ *  png2pnm
+ */
+BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file, BOOL raw, BOOL alpha)
+{
+  png_struct    *png_ptr = NULL;
+  png_info        *info_ptr = NULL;
+  png_byte      buf[8];
+  png_byte      *png_pixels = NULL;
+  png_byte      **row_pointers = NULL;
+  png_byte      *pix_ptr = NULL;
+  png_uint_32   row_bytes;
+  png_uint_32   width;
+  png_uint_32   height;
+  int           bit_depth;
+  int           channels;
+  int           color_type;
+  int           alpha_present;
+  int           row, col;
+  int           ret;
+  int           i;
+  long          dep_16;
+  /* read and check signature in PNG file */
+  ret = fread (buf, 1, 8, png_file);
+  if (ret != 8)
+    return FALSE;
+  ret = png_sig_cmp (buf, 0, 8);
+  if (ret)
+    return FALSE;
+  /* create png and info structures */
+  png_ptr = png_create_read_struct (PNG_LIBPNG_VER_STRING,
+    NULL, NULL, NULL);
+  if (!png_ptr)
+    return FALSE;   /* out of memory */
+  info_ptr = png_create_info_struct (png_ptr);
+  if (!info_ptr)
+  {
+    png_destroy_read_struct (&png_ptr, NULL, NULL);
+    return FALSE;   /* out of memory */
+  }
+  if (setjmp (png_jmpbuf(png_ptr)))
+  {
+    png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
+    return FALSE;
+  }
+  /* set up the input control for C streams */
+  png_init_io (png_ptr, png_file);
+  png_set_sig_bytes (png_ptr, 8);  /* we already read the 8 signature bytes */
+  /* read the file information */
+  png_read_info (png_ptr, info_ptr);
+  /* get size and bit-depth of the PNG-image */
+  png_get_IHDR (png_ptr, info_ptr,
+    &width, &height, &bit_depth, &color_type,
+    NULL, NULL, NULL);
+  /* set-up the transformations */
+  /* transform paletted images into full-color rgb */
+  if (color_type == PNG_COLOR_TYPE_PALETTE)
+    png_set_expand (png_ptr);
+  /* expand images to bit-depth 8 (only applicable for grayscale images) */
+  if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8)
+    png_set_expand (png_ptr);
+  /* transform transparency maps into full alpha-channel */
+  if (png_get_valid (png_ptr, info_ptr, PNG_INFO_tRNS))
+    png_set_expand (png_ptr);
+#ifdef NJET
+  /* downgrade 16-bit images to 8 bit */
+  if (bit_depth == 16)
+    png_set_strip_16 (png_ptr);
+  /* transform grayscale images into full-color */
+  if (color_type == PNG_COLOR_TYPE_GRAY ||
+    color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+    png_set_gray_to_rgb (png_ptr);
+  /* only if file has a file gamma, we do a correction */
+  if (png_get_gAMA (png_ptr, info_ptr, &file_gamma))
+    png_set_gamma (png_ptr, (double) 2.2, file_gamma);
+#endif
+  /* all transformations have been registered; now update info_ptr data,
+   * get rowbytes and channels, and allocate image memory */
+  png_read_update_info (png_ptr, info_ptr);
+  /* get the new color-type and bit-depth (after expansion/stripping) */
+  png_get_IHDR (png_ptr, info_ptr, &width, &height, &bit_depth, &color_type,
+    NULL, NULL, NULL);
+  /* check for 16-bit files */
+  if (bit_depth == 16)
+  {
+    raw = FALSE;
+#ifdef __TURBOC__
+    pnm_file->flags &= ~((unsigned) _F_BIN);
+#endif
+  }
+  /* calculate new number of channels and store alpha-presence */
+  if (color_type == PNG_COLOR_TYPE_GRAY)
+    channels = 1;
+  else if (color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+    channels = 2;
+  else if (color_type == PNG_COLOR_TYPE_RGB)
+    channels = 3;
+  else if (color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+    channels = 4;
+  else
+    channels = 0; /* should never happen */
+  alpha_present = (channels - 1) % 2;
+  /* check if alpha is expected to be present in file */
+  if (alpha && !alpha_present)
+  {
+    fprintf (stderr, "PNG2PNM\n");
+    fprintf (stderr, "Error:  PNG-file doesn't contain alpha channel\n");
+    exit (1);
+  }
+  /* row_bytes is the width x number of channels x (bit-depth / 8) */
+  row_bytes = png_get_rowbytes (png_ptr, info_ptr);
+  if ((png_pixels = (png_byte *) malloc (row_bytes * height * sizeof (png_byte))) == NULL) {
+    png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
+    return FALSE;
+  }
+  if ((row_pointers = (png_byte **) malloc (height * sizeof (png_bytep))) == NULL)
+  {
+    png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
+    free (png_pixels);
+    png_pixels = NULL;
+    return FALSE;
+  }
+  /* set the individual row_pointers to point at the correct offsets */
+  for (i = 0; i < (height); i++)
+    row_pointers[i] = png_pixels + i * row_bytes;
+  /* now we can go ahead and just read the whole image */
+  png_read_image (png_ptr, row_pointers);
+  /* read rest of file, and get additional chunks in info_ptr - REQUIRED */
+  png_read_end (png_ptr, info_ptr);
+  /* clean up after the read, and free any memory allocated - REQUIRED */
+  png_destroy_read_struct (&png_ptr, &info_ptr, (png_infopp) NULL);
+  /* write header of PNM file */
+  if ((color_type == PNG_COLOR_TYPE_GRAY) ||
+      (color_type == PNG_COLOR_TYPE_GRAY_ALPHA))
+  {
+    fprintf (pnm_file, "%s\n", (raw) ? "P5" : "P2");
+    fprintf (pnm_file, "%d %d\n", (int) width, (int) height);
+    fprintf (pnm_file, "%ld\n", ((1L << (int) bit_depth) - 1L));
+  }
+  else if ((color_type == PNG_COLOR_TYPE_RGB) ||
+           (color_type == PNG_COLOR_TYPE_RGB_ALPHA))
+  {
+    fprintf (pnm_file, "%s\n", (raw) ? "P6" : "P3");
+    fprintf (pnm_file, "%d %d\n", (int) width, (int) height);
+    fprintf (pnm_file, "%ld\n", ((1L << (int) bit_depth) - 1L));
+  }
+  /* write header of PGM file with alpha channel */
+  if ((alpha) &&
+      ((color_type == PNG_COLOR_TYPE_GRAY_ALPHA) ||
+       (color_type == PNG_COLOR_TYPE_RGB_ALPHA)))
+  {
+    fprintf (alpha_file, "%s\n", (raw) ? "P5" : "P2");
+    fprintf (alpha_file, "%d %d\n", (int) width, (int) height);
+    fprintf (alpha_file, "%ld\n", ((1L << (int) bit_depth) - 1L));
+  }
+  /* write data to PNM file */
+  pix_ptr = png_pixels;
+  for (row = 0; row < height; row++)
+  {
+    for (col = 0; col < width; col++)
+    {
+      for (i = 0; i < (channels - alpha_present); i++)
+      {
+        if (raw)
+          fputc ((int) *pix_ptr++ , pnm_file);
+        else
+          if (bit_depth == 16){
+            dep_16 = (long) *pix_ptr++;
+            fprintf (pnm_file, "%ld ", (dep_16 << 8) + ((long) *pix_ptr++));
+          }
+          else
+            fprintf (pnm_file, "%ld ", (long) *pix_ptr++);
+      }
+      if (alpha_present)
+      {
+        if (!alpha)
+        {
+          pix_ptr++; /* alpha */
+          if (bit_depth == 16)
+            pix_ptr++;
+        }
+        else /* output alpha-channel as pgm file */
+        {
+          if (raw)
+            fputc ((int) *pix_ptr++ , alpha_file);
+          else
+            if (bit_depth == 16){
+              dep_16 = (long) *pix_ptr++;
+              fprintf (alpha_file, "%ld ", (dep_16 << 8) + (long) *pix_ptr++);
+            }
+            else
+              fprintf (alpha_file, "%ld ", (long) *pix_ptr++);
+        }
+      } /* if alpha_present */
+      if (!raw)
+        if (col % 4 == 3)
+          fprintf (pnm_file, "\n");
+    } /* end for col */
+    if (!raw)
+      if (col % 4 != 0)
+        fprintf (pnm_file, "\n");
+  } /* end for row */
+  if (row_pointers != (unsigned char**) NULL)
+    free (row_pointers);
+  if (png_pixels != (unsigned char*) NULL)
+    free (png_pixels);
+  return TRUE;
+} /* end of source */
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminus/png2pnm.sh b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminus/png2pnm.sh
new file mode 100755
index 0000000..ee39664
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminus/png2pnm.sh
@@ -0,0 +1,42 @@
+#!/bin/sh
+# -- grayscale
+./png2pnm -noraw ../pngsuite/basn0g01.png basn0g01.pgm
+./png2pnm -noraw ../pngsuite/basn0g02.png basn0g02.pgm
+./png2pnm -noraw ../pngsuite/basn0g04.png basn0g04.pgm
+./png2pnm -noraw ../pngsuite/basn0g08.png basn0g08.pgm
+./png2pnm -noraw ../pngsuite/basn0g16.png basn0g16.pgm
+# -- full-color
+./png2pnm -noraw ../pngsuite/basn2c08.png basn2c08.ppm
+./png2pnm -noraw ../pngsuite/basn2c16.png basn2c16.ppm
+# -- palletted
+./png2pnm -noraw ../pngsuite/basn3p01.png basn3p01.ppm
+./png2pnm -noraw ../pngsuite/basn3p02.png basn3p02.ppm
+./png2pnm -noraw ../pngsuite/basn3p04.png basn3p04.ppm
+./png2pnm -noraw ../pngsuite/basn3p08.png basn3p08.ppm
+# -- gray with alpha-channel
+./png2pnm -noraw ../pngsuite/basn4a08.png basn4a08.pgm
+./png2pnm -noraw ../pngsuite/basn4a16.png basn4a16.pgm
+# -- color with alpha-channel
+./png2pnm -noraw -alpha basn6a08.pgm ../pngsuite/basn6a08.png basn6a08.ppm
+./png2pnm -noraw -alpha basn6a16.pgm ../pngsuite/basn6a16.png basn6a16.ppm
+# -- grayscale
+./png2pnm -raw ../pngsuite/basn0g01.png rawn0g01.pgm
+./png2pnm -raw ../pngsuite/basn0g02.png rawn0g02.pgm
+./png2pnm -raw ../pngsuite/basn0g04.png rawn0g04.pgm
+./png2pnm -raw ../pngsuite/basn0g08.png rawn0g08.pgm
+./png2pnm -raw ../pngsuite/basn0g16.png rawn0g16.pgm
+# -- full-color
+./png2pnm -raw ../pngsuite/basn2c08.png rawn2c08.ppm
+./png2pnm -raw ../pngsuite/basn2c16.png rawn2c16.ppm
+# -- palletted
+./png2pnm -raw ../pngsuite/basn3p01.png rawn3p01.ppm
+./png2pnm -raw ../pngsuite/basn3p02.png rawn3p02.ppm
+./png2pnm -raw ../pngsuite/basn3p04.png rawn3p04.ppm
+./png2pnm -raw ../pngsuite/basn3p08.png rawn3p08.ppm
+# -- gray with alpha-channel
+./png2pnm -raw ../pngsuite/basn4a08.png rawn4a08.pgm
+./png2pnm -raw ../pngsuite/basn4a16.png rawn4a16.pgm
+# -- color with alpha-channel
+./png2pnm -noraw -alpha rawn6a08.pgm ../pngsuite/basn6a08.png rawn6a08.ppm
+./png2pnm -noraw -alpha rawn6a16.pgm ../pngsuite/basn6a16.png rawn6a16.ppm
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminus/pngminus.bat b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminus/pngminus.bat
new file mode 100644
index 0000000..5f8d2d4
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminus/pngminus.bat
@@ -0,0 +1,4 @@
+make -f makefile.tc3
+call png2pnm.bat
+call pnm2png.bat
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminus/pngminus.sh b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminus/pngminus.sh
new file mode 100755
index 0000000..adcef55
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminus/pngminus.sh
@@ -0,0 +1,5 @@
+#!/bin/sh
+make -f makefile.std
+sh png2pnm.sh
+sh pnm2png.sh
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminus/pnm2png.bat b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminus/pnm2png.bat
new file mode 100644
index 0000000..5b9977a
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminus/pnm2png.bat
@@ -0,0 +1,41 @@
+REM -- grayscale
+pnm2png.exe basn0g01.pgm basn0g01.png
+pnm2png.exe basn0g02.pgm basn0g02.png
+pnm2png.exe basn0g04.pgm basn0g04.png
+pnm2png.exe basn0g08.pgm basn0g08.png
+pnm2png.exe basn0g16.pgm basn0g16.png
+REM -- full-color
+pnm2png.exe basn2c08.ppm basn2c08.png
+pnm2png.exe basn2c16.ppm basn2c16.png
+REM -- palletted
+pnm2png.exe basn3p01.ppm basn3p01.png
+pnm2png.exe basn3p02.ppm basn3p02.png
+pnm2png.exe basn3p04.ppm basn3p04.png
+pnm2png.exe basn3p08.ppm basn3p08.png
+REM -- gray with alpha-channel
+pnm2png.exe -alpha basn6a08.pgm basn4a08.pgm basn4a08.png
+pnm2png.exe -alpha basn6a16.pgm basn4a16.pgm basn4a16.png
+REM -- color with alpha-channel
+pnm2png.exe -alpha basn6a08.pgm basn6a08.ppm basn6a08.png
+pnm2png.exe -alpha basn6a16.pgm basn6a16.ppm basn6a16.png
+REM -- grayscale
+pnm2png.exe rawn0g01.pgm rawn0g01.png
+pnm2png.exe rawn0g02.pgm rawn0g02.png
+pnm2png.exe rawn0g04.pgm rawn0g04.png
+pnm2png.exe rawn0g08.pgm rawn0g08.png
+pnm2png.exe rawn0g16.pgm rawn0g16.png
+REM -- full-color
+pnm2png.exe rawn2c08.ppm rawn2c08.png
+pnm2png.exe rawn2c16.ppm rawn2c16.png
+REM -- palletted
+pnm2png.exe rawn3p01.ppm rawn3p01.png
+pnm2png.exe rawn3p02.ppm rawn3p02.png
+pnm2png.exe rawn3p04.ppm rawn3p04.png
+pnm2png.exe rawn3p08.ppm rawn3p08.png
+REM -- gray with alpha-channel
+pnm2png.exe -alpha rawn6a08.pgm rawn4a08.pgm rawn4a08.png
+pnm2png.exe -alpha rawn6a16.pgm rawn4a16.pgm rawn4a16.png
+REM -- color with alpha-channel
+pnm2png.exe -alpha rawn6a08.pgm rawn6a08.ppm rawn6a08.png
+pnm2png.exe -alpha rawn6a16.pgm rawn6a16.ppm rawn6a16.png
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminus/pnm2png.c b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminus/pnm2png.c
new file mode 100644
index 0000000..2f321cc
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminus/pnm2png.c
@@ -0,0 +1,533 @@
+/*
+ *  pnm2png.c --- conversion from PBM/PGM/PPM-file to PNG-file
+ *  copyright (C) 1999 by Willem van Schaik <willem@schaik.com>
+ *
+ *  version 1.0 - 1999.10.15 - First version.
+ *
+ *  Permission to use, copy, modify, and distribute this software and
+ *  its documentation for any purpose and without fee is hereby granted,
+ *  provided that the above copyright notice appear in all copies and
+ *  that both that copyright notice and this permission notice appear in
+ *  supporting documentation. This software is provided "as is" without
+ *  express or implied warranty.
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#ifdef __TURBOC__
+#include <mem.h>
+#include <fcntl.h>
+#endif
+#ifndef BOOL
+#define BOOL unsigned char
+#endif
+#ifndef TRUE
+#define TRUE (BOOL) 1
+#endif
+#ifndef FALSE
+#define FALSE (BOOL) 0
+#endif
+#define STDIN  0
+#define STDOUT 1
+#define STDERR 2
+/* to make pnm2png verbose so we can find problems (needs to be before png.h) */
+#ifndef PNG_DEBUG
+#define PNG_DEBUG 0
+#endif
+#include "png.h"
+/* Define png_jmpbuf() in case we are using a pre-1.0.6 version of libpng */
+#ifndef png_jmpbuf
+#  define png_jmpbuf(png_ptr) ((png_ptr)->jmpbuf)
+#endif
+/* function prototypes */
+int  main (int argc, char *argv[]);
+void usage ();
+BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace, BOOL alpha);
+void get_token(FILE *pnm_file, char *token);
+png_uint_32 get_data (FILE *pnm_file, int depth);
+png_uint_32 get_value (FILE *pnm_file, int depth);
+/*
+ *  main
+ */
+int main(int argc, char *argv[])
+{
+  FILE *fp_rd = stdin;
+  FILE *fp_al = NULL;
+  FILE *fp_wr = stdout;
+  BOOL interlace = FALSE;
+  BOOL alpha = FALSE;
+  int argi;
+  for (argi = 1; argi < argc; argi++)
+  {
+    if (argv[argi][0] == '-')
+    {
+      switch (argv[argi][1])
+      {
+        case 'i':
+          interlace = TRUE;
+          break;
+        case 'a':
+          alpha = TRUE;
+          argi++;
+          if ((fp_al = fopen (argv[argi], "rb")) == NULL)
+          {
+            fprintf (stderr, "PNM2PNG\n");
+            fprintf (stderr, "Error:  alpha-channel file %s does not exist\n",
+               argv[argi]);
+            exit (1);
+          }
+          break;
+        case 'h':
+        case '?':
+          usage();
+          exit(0);
+          break;
+        default:
+          fprintf (stderr, "PNM2PNG\n");
+          fprintf (stderr, "Error:  unknown option %s\n", argv[argi]);
+          usage();
+          exit(1);
+          break;
+      } /* end switch */
+    }
+    else if (fp_rd == stdin)
+    {
+      if ((fp_rd = fopen (argv[argi], "rb")) == NULL)
+      {
+        fprintf (stderr, "PNM2PNG\n");
+        fprintf (stderr, "Error:  file %s does not exist\n", argv[argi]);
+        exit (1);
+      }
+    }
+    else if (fp_wr == stdout)
+    {
+      if ((fp_wr = fopen (argv[argi], "wb")) == NULL)
+      {
+        fprintf (stderr, "PNM2PNG\n");
+        fprintf (stderr, "Error:  can not create PNG-file %s\n", argv[argi]);
+        exit (1);
+      }
+    }
+    else
+    {
+      fprintf (stderr, "PNM2PNG\n");
+      fprintf (stderr, "Error:  too many parameters\n");
+      usage();
+      exit (1);
+    }
+  } /* end for */
+#ifdef __TURBOC__
+  /* set stdin/stdout to binary, we're reading the PNM always! in binary format */
+  if (fp_rd == stdin)
+  {
+    setmode (STDIN, O_BINARY);
+  }
+  if (fp_wr == stdout)
+  {
+    setmode (STDOUT, O_BINARY);
+  }
+#endif
+  /* call the conversion program itself */
+  if (pnm2png (fp_rd, fp_wr, fp_al, interlace, alpha) == FALSE)
+  {
+    fprintf (stderr, "PNM2PNG\n");
+    fprintf (stderr, "Error:  unsuccessful converting to PNG-image\n");
+    exit (1);
+  }
+  /* close input file */
+  fclose (fp_rd);
+  /* close output file */
+  fclose (fp_wr);
+  /* close alpha file */
+  if (alpha)
+    fclose (fp_al);
+  return 0;
+}
+/*
+ *  usage
+ */
+void usage()
+{
+  fprintf (stderr, "PNM2PNG\n");
+  fprintf (stderr, "   by Willem van Schaik, 1999\n");
+#ifdef __TURBOC__
+  fprintf (stderr, "   for Turbo-C and Borland-C compilers\n");
+#else
+  fprintf (stderr, "   for Linux (and Unix) compilers\n");
+#endif
+  fprintf (stderr, "Usage:  pnm2png [options] <file>.<pnm> [<file>.png]\n");
+  fprintf (stderr, "   or:  ... | pnm2png [options]\n");
+  fprintf (stderr, "Options:\n");
+  fprintf (stderr, "   -i[nterlace]   write png-file with interlacing on\n");
+  fprintf (stderr, "   -a[lpha] <file>.pgm read PNG alpha channel as pgm-file\n");
+  fprintf (stderr, "   -h | -?  print this help-information\n");
+}
+/*
+ *  pnm2png
+ */
+BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace, BOOL alpha)
+{
+  png_struct    *png_ptr = NULL;
+  png_info      *info_ptr = NULL;
+  png_byte      *png_pixels = NULL;
+  png_byte      **row_pointers = NULL;
+  png_byte      *pix_ptr = NULL;
+  png_uint_32   row_bytes;
+  char          type_token[16];
+  char          width_token[16];
+  char          height_token[16];
+  char          maxval_token[16];
+  int           color_type;
+  png_uint_32   width, alpha_width;
+  png_uint_32   height, alpha_height;
+  png_uint_32   maxval;
+  int           bit_depth = 0;
+  int           channels;
+  int           alpha_depth = 0;
+  int           alpha_present;
+  int           row, col;
+  BOOL          raw, alpha_raw = FALSE;
+  png_uint_32   tmp16;
+  int           i;
+  /* read header of PNM file */
+  get_token(pnm_file, type_token);
+  if (type_token[0] != 'P')
+  {
+    return FALSE;
+  }
+  else if ((type_token[1] == '1') || (type_token[1] == '4'))
+  {
+    raw = (type_token[1] == '4');
+    color_type = PNG_COLOR_TYPE_GRAY;
+    bit_depth = 1;
+  }
+  else if ((type_token[1] == '2') || (type_token[1] == '5'))
+  {
+    raw = (type_token[1] == '5');
+    color_type = PNG_COLOR_TYPE_GRAY;
+    get_token(pnm_file, width_token);
+    sscanf (width_token, "%lu", &width);
+    get_token(pnm_file, height_token);
+    sscanf (height_token, "%lu", &height);
+    get_token(pnm_file, maxval_token);
+    sscanf (maxval_token, "%lu", &maxval);
+    if (maxval <= 1)
+      bit_depth = 1;
+    else if (maxval <= 3)
+      bit_depth = 2;
+    else if (maxval <= 15)
+      bit_depth = 4;
+    else if (maxval <= 255)
+      bit_depth = 8;
+    else /* if (maxval <= 65535) */
+      bit_depth = 16;
+  }
+  else if ((type_token[1] == '3') || (type_token[1] == '6'))
+  {
+    raw = (type_token[1] == '6');
+    color_type = PNG_COLOR_TYPE_RGB;
+    get_token(pnm_file, width_token);
+    sscanf (width_token, "%lu", &width);
+    get_token(pnm_file, height_token);
+    sscanf (height_token, "%lu", &height);
+    get_token(pnm_file, maxval_token);
+    sscanf (maxval_token, "%lu", &maxval);
+    if (maxval <= 1)
+      bit_depth = 1;
+    else if (maxval <= 3)
+      bit_depth = 2;
+    else if (maxval <= 15)
+      bit_depth = 4;
+    else if (maxval <= 255)
+      bit_depth = 8;
+    else /* if (maxval <= 65535) */
+      bit_depth = 16;
+  }
+  else
+  {
+    return FALSE;
+  }
+  /* read header of PGM file with alpha channel */
+  if (alpha)
+  {
+    if (color_type == PNG_COLOR_TYPE_GRAY)
+      color_type = PNG_COLOR_TYPE_GRAY_ALPHA;
+    if (color_type == PNG_COLOR_TYPE_RGB)
+      color_type = PNG_COLOR_TYPE_RGB_ALPHA;
+    get_token(alpha_file, type_token);
+    if (type_token[0] != 'P')
+    {
+      return FALSE;
+    }
+    else if ((type_token[1] == '2') || (type_token[1] == '5'))
+    {
+      alpha_raw = (type_token[1] == '5');
+      get_token(alpha_file, width_token);
+      sscanf (width_token, "%lu", &alpha_width);
+      if (alpha_width != width)
+        return FALSE;
+      get_token(alpha_file, height_token);
+      sscanf (height_token, "%lu", &alpha_height);
+      if (alpha_height != height)
+        return FALSE;
+      get_token(alpha_file, maxval_token);
+      sscanf (maxval_token, "%lu", &maxval);
+      if (maxval <= 1)
+        alpha_depth = 1;
+      else if (maxval <= 3)
+        alpha_depth = 2;
+      else if (maxval <= 15)
+        alpha_depth = 4;
+      else if (maxval <= 255)
+        alpha_depth = 8;
+      else /* if (maxval <= 65535) */
+        alpha_depth = 16;
+      if (alpha_depth != bit_depth)
+        return FALSE;
+    }
+    else
+    {
+      return FALSE;
+    }
+  } /* end if alpha */
+  /* calculate the number of channels and store alpha-presence */
+  if (color_type == PNG_COLOR_TYPE_GRAY)
+    channels = 1;
+  else if (color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+    channels = 2;
+  else if (color_type == PNG_COLOR_TYPE_RGB)
+    channels = 3;
+  else if (color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+    channels = 4;
+  else
+    channels = 0; /* should not happen */
+  alpha_present = (channels - 1) % 2;
+  /* row_bytes is the width x number of channels x (bit-depth / 8) */
+  row_bytes = width * channels * ((bit_depth <= 8) ? 1 : 2);
+  if ((png_pixels = (png_byte *) malloc (row_bytes * height * sizeof (png_byte))) == NULL)
+    return FALSE;
+  /* read data from PNM file */
+  pix_ptr = png_pixels;
+  for (row = 0; row < height; row++)
+  {
+    for (col = 0; col < width; col++)
+    {
+      for (i = 0; i < (channels - alpha_present); i++)
+      {
+        if (raw)
+          *pix_ptr++ = get_data (pnm_file, bit_depth);
+        else
+          if (bit_depth <= 8)
+            *pix_ptr++ = get_value (pnm_file, bit_depth);
+          else
+          {
+            tmp16 = get_value (pnm_file, bit_depth);
+            *pix_ptr = (png_byte) ((tmp16 >> 8) & 0xFF);
+            pix_ptr++;
+            *pix_ptr = (png_byte) (tmp16 & 0xFF);
+            pix_ptr++;
+          }
+      }
+      if (alpha) /* read alpha-channel from pgm file */
+      {
+        if (alpha_raw)
+          *pix_ptr++ = get_data (alpha_file, alpha_depth);
+        else
+          if (alpha_depth <= 8)
+            *pix_ptr++ = get_value (alpha_file, bit_depth);
+          else
+          {
+            tmp16 = get_value (alpha_file, bit_depth);
+            *pix_ptr++ = (png_byte) ((tmp16 >> 8) & 0xFF);
+            *pix_ptr++ = (png_byte) (tmp16 & 0xFF);
+          }
+      } /* if alpha */
+    } /* end for col */
+  } /* end for row */
+  /* prepare the standard PNG structures */
+  png_ptr = png_create_write_struct (PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+  if (!png_ptr)
+  {
+    return FALSE;
+  }
+  info_ptr = png_create_info_struct (png_ptr);
+  if (!info_ptr)
+  {
+    png_destroy_write_struct (&png_ptr, (png_infopp) NULL);
+    return FALSE;
+  }
+  /* setjmp() must be called in every function that calls a PNG-reading libpng function */
+  if (setjmp (png_jmpbuf(png_ptr)))
+  {
+    png_destroy_write_struct (&png_ptr, (png_infopp) NULL);
+    return FALSE;
+  }
+  /* initialize the png structure */
+  png_init_io (png_ptr, png_file);
+  /* we're going to write more or less the same PNG as the input file */
+  png_set_IHDR (png_ptr, info_ptr, width, height, bit_depth, color_type,
+    (!interlace) ? PNG_INTERLACE_NONE : PNG_INTERLACE_ADAM7,
+    PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
+  /* write the file header information */
+  png_write_info (png_ptr, info_ptr);
+  /* if needed we will allocate memory for an new array of row-pointers */
+  if (row_pointers == (unsigned char**) NULL)
+  {
+    if ((row_pointers = (png_byte **) malloc (height * sizeof (png_bytep))) == NULL)
+    {
+      png_destroy_write_struct (&png_ptr, (png_infopp) NULL);
+      return FALSE;
+    }
+  }
+  /* set the individual row_pointers to point at the correct offsets */
+  for (i = 0; i < (height); i++)
+    row_pointers[i] = png_pixels + i * row_bytes;
+  /* write out the entire image data in one call */
+  png_write_image (png_ptr, row_pointers);
+  /* write the additional chuncks to the PNG file (not really needed) */
+  png_write_end (png_ptr, info_ptr);
+  /* clean up after the write, and free any memory allocated */
+  png_destroy_write_struct (&png_ptr, (png_infopp) NULL);
+  if (row_pointers != (unsigned char**) NULL)
+    free (row_pointers);
+  if (png_pixels != (unsigned char*) NULL)
+    free (png_pixels);
+  return TRUE;
+} /* end of pnm2png */
+/*
+ * get_token() - gets the first string after whitespace
+ */
+void get_token(FILE *pnm_file, char *token)
+{
+  int i = 0;
+  /* remove white-space */
+  do
+  {
+    token[i] = (unsigned char) fgetc (pnm_file);
+  }
+  while ((token[i] == '\n') || (token[i] == '\r') || (token[i] == ' '));
+  /* read string */
+  do
+  {
+    i++;
+    token[i] = (unsigned char) fgetc (pnm_file);
+  }
+  while ((token[i] != '\n') && (token[i] != '\r') && (token[i] != ' '));
+  token[i] = '\0';
+  return;
+}
+/*
+ * get_data() - takes first byte and converts into next pixel value,
+ *        taking as much bits as defined by bit-depth and
+ *        using the bit-depth to fill up a byte (0Ah -> AAh)
+ */
+png_uint_32 get_data (FILE *pnm_file, int depth)
+{
+  static int bits_left = 0;
+  static int old_value = 0;
+  static int mask = 0;
+  int i;
+  png_uint_32 ret_value;
+  if (mask == 0)
+    for (i = 0; i < depth; i++)
+      mask = (mask >> 1) | 0x80;
+  if (bits_left <= 0)
+  {
+    old_value = fgetc (pnm_file);
+    bits_left = 8;
+  }
+  ret_value = old_value & mask;
+  for (i = 1; i < (8 / depth); i++)
+    ret_value = ret_value || (ret_value >> depth);
+  old_value = (old_value << depth) & 0xFF;
+  bits_left -= depth;
+  return ret_value;
+}
+/*
+ * get_value() - takes first (numeric) string and converts into number,
+ *         using the bit-depth to fill up a byte (0Ah -> AAh)
+ */
+png_uint_32 get_value (FILE *pnm_file, int depth)
+{
+  static png_uint_32 mask = 0;
+  png_byte token[16];
+  png_uint_32 ret_value;
+  int i = 0;
+  if (mask == 0)
+    for (i = 0; i < depth; i++)
+      mask = (mask << 1) | 0x01;
+  get_token (pnm_file, (char *) token);
+  sscanf ((const char *) token, "%lu", &ret_value);
+  ret_value &= mask;
+  if (depth < 8)
+    for (i = 0; i < (8 / depth); i++)
+      ret_value = (ret_value << depth) || ret_value;
+  return ret_value;
+}
+/* end of source */
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminus/pnm2png.sh b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminus/pnm2png.sh
new file mode 100755
index 0000000..975f047
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/pngminus/pnm2png.sh
@@ -0,0 +1,42 @@
+#!/bin/sh
+# -- grayscale
+./pnm2png basn0g01.pgm basn0g01.png
+./pnm2png basn0g02.pgm basn0g02.png
+./pnm2png basn0g04.pgm basn0g04.png
+./pnm2png basn0g08.pgm basn0g08.png
+./pnm2png basn0g16.pgm basn0g16.png
+# -- full-color
+./pnm2png basn2c08.ppm basn2c08.png
+./pnm2png basn2c16.ppm basn2c16.png
+# -- palletted
+./pnm2png basn3p01.ppm basn3p01.png
+./pnm2png basn3p02.ppm basn3p02.png
+./pnm2png basn3p04.ppm basn3p04.png
+./pnm2png basn3p08.ppm basn3p08.png
+# -- gray with alpha-channel
+./pnm2png -alpha basn6a08.pgm basn4a08.pgm basn4a08.png
+./pnm2png -alpha basn6a16.pgm basn4a16.pgm basn4a16.png
+# -- color with alpha-channel
+./pnm2png -alpha basn6a08.pgm basn6a08.ppm basn6a08.png
+./pnm2png -alpha basn6a16.pgm basn6a16.ppm basn6a16.png
+# -- grayscale
+./pnm2png rawn0g01.pgm rawn0g01.png
+./pnm2png rawn0g02.pgm rawn0g02.png
+./pnm2png rawn0g04.pgm rawn0g04.png
+./pnm2png rawn0g08.pgm rawn0g08.png
+./pnm2png rawn0g16.pgm rawn0g16.png
+# -- full-color
+./pnm2png rawn2c08.ppm rawn2c08.png
+./pnm2png rawn2c16.ppm rawn2c16.png
+# -- palletted
+./pnm2png rawn3p01.ppm rawn3p01.png
+./pnm2png rawn3p02.ppm rawn3p02.png
+./pnm2png rawn3p04.ppm rawn3p04.png
+./pnm2png rawn3p08.ppm rawn3p08.png
+# -- gray with alpha-channel
+./pnm2png -alpha rawn6a08.pgm rawn4a08.pgm rawn4a08.png
+./pnm2png -alpha rawn6a16.pgm rawn4a16.pgm rawn4a16.png
+# -- color with alpha-channel
+./pnm2png -alpha rawn6a08.pgm rawn6a08.ppm rawn6a08.png
+./pnm2png -alpha rawn6a16.pgm rawn6a16.ppm rawn6a16.png
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diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/visupng/PngFile.c b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/visupng/PngFile.c
new file mode 100644
index 0000000..f3e440a
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/visupng/PngFile.c
@@ -0,0 +1,450 @@
+/*-------------------------------------
+ *  PNGFILE.C -- Image File Functions
+ *-------------------------------------
+ *
+ * Copyright 2000, Willem van Schaik.
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+#include <windows.h>
+#include <commdlg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include "png.h"
+#include "pngfile.h"
+#include "cexcept.h"
+define_exception_type(const char *);
+extern struct exception_context the_exception_context[1];
+struct exception_context the_exception_context[1];
+png_const_charp msg;
+static OPENFILENAME ofn;
+static png_structp png_ptr = NULL;
+static png_infop info_ptr = NULL;
+/* cexcept interface */
+static void
+png_cexcept_error(png_structp png_ptr, png_const_charp msg)
+{
+   if(png_ptr)
+     ;
+#ifdef PNG_CONSOLE_IO_SUPPORTED
+   fprintf(stderr, "libpng error: %s\n", msg);
+#endif
+   {
+      Throw msg;
+   }
+}
+/* Windows open-file functions */
+void PngFileInitialize (HWND hwnd)
+{
+    static TCHAR szFilter[] = TEXT ("PNG Files (*.PNG)\0*.png\0")
+        TEXT ("All Files (*.*)\0*.*\0\0");
+    ofn.lStructSize       = sizeof (OPENFILENAME);
+    ofn.hwndOwner         = hwnd;
+    ofn.hInstance         = NULL;
+    ofn.lpstrFilter       = szFilter;
+    ofn.lpstrCustomFilter = NULL;
+    ofn.nMaxCustFilter    = 0;
+    ofn.nFilterIndex      = 0;
+    ofn.lpstrFile         = NULL;          /* Set in Open and Close functions */
+    ofn.nMaxFile          = MAX_PATH;
+    ofn.lpstrFileTitle    = NULL;          /* Set in Open and Close functions */
+    ofn.nMaxFileTitle     = MAX_PATH;
+    ofn.lpstrInitialDir   = NULL;
+    ofn.lpstrTitle        = NULL;
+    ofn.Flags             = 0;             /* Set in Open and Close functions */
+    ofn.nFileOffset       = 0;
+    ofn.nFileExtension    = 0;
+    ofn.lpstrDefExt       = TEXT ("png");
+    ofn.lCustData         = 0;
+    ofn.lpfnHook          = NULL;
+    ofn.lpTemplateName    = NULL;
+}
+BOOL PngFileOpenDlg (HWND hwnd, PTSTR pstrFileName, PTSTR pstrTitleName)
+{
+    ofn.hwndOwner         = hwnd;
+    ofn.lpstrFile         = pstrFileName;
+    ofn.lpstrFileTitle    = pstrTitleName;
+    ofn.Flags             = OFN_HIDEREADONLY;
+    return GetOpenFileName (&ofn);
+}
+BOOL PngFileSaveDlg (HWND hwnd, PTSTR pstrFileName, PTSTR pstrTitleName)
+{
+    ofn.hwndOwner         = hwnd;
+    ofn.lpstrFile         = pstrFileName;
+    ofn.lpstrFileTitle    = pstrTitleName;
+    ofn.Flags             = OFN_HIDEREADONLY | OFN_OVERWRITEPROMPT;
+    return GetSaveFileName (&ofn);
+}
+/* PNG image handler functions */
+BOOL PngLoadImage (PTSTR pstrFileName, png_byte **ppbImageData,
+                   int *piWidth, int *piHeight, int *piChannels, png_color *pBkgColor)
+{
+    static FILE        *pfFile;
+    png_byte            pbSig[8];
+    int                 iBitDepth;
+    int                 iColorType;
+    double              dGamma;
+    png_color_16       *pBackground;
+    png_uint_32         ulChannels;
+    png_uint_32         ulRowBytes;
+    png_byte           *pbImageData = *ppbImageData;
+    static png_byte   **ppbRowPointers = NULL;
+    int                 i;
+    /* open the PNG input file */
+    if (!pstrFileName)
+    {
+        *ppbImageData = pbImageData = NULL;
+        return FALSE;
+    }
+    if (!(pfFile = fopen(pstrFileName, "rb")))
+    {
+        *ppbImageData = pbImageData = NULL;
+        return FALSE;
+    }
+    /* first check the eight byte PNG signature */
+    fread(pbSig, 1, 8, pfFile);
+    if (png_sig_cmp(pbSig, 0, 8))
+    {
+        *ppbImageData = pbImageData = NULL;
+        return FALSE;
+    }
+    /* create the two png(-info) structures */
+    png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL,
+      (png_error_ptr)png_cexcept_error, (png_error_ptr)NULL);
+    if (!png_ptr)
+    {
+        *ppbImageData = pbImageData = NULL;
+        return FALSE;
+    }
+    info_ptr = png_create_info_struct(png_ptr);
+    if (!info_ptr)
+    {
+        png_destroy_read_struct(&png_ptr, NULL, NULL);
+        *ppbImageData = pbImageData = NULL;
+        return FALSE;
+    }
+    Try
+    {
+        /* initialize the png structure */
+#ifdef PNG_STDIO_SUPPORTED
+        png_init_io(png_ptr, pfFile);
+#else
+        png_set_read_fn(png_ptr, (png_voidp)pfFile, png_read_data);
+#endif
+        png_set_sig_bytes(png_ptr, 8);
+        /* read all PNG info up to image data */
+        png_read_info(png_ptr, info_ptr);
+        /* get width, height, bit-depth and color-type */
+        png_get_IHDR(png_ptr, info_ptr, piWidth, piHeight, &iBitDepth,
+            &iColorType, NULL, NULL, NULL);
+        /* expand images of all color-type and bit-depth to 3x8-bit RGB */
+        /* let the library process alpha, transparency, background, etc. */
+#ifdef PNG_READ_16_TO_8_SUPPORTED
+    if (iBitDepth == 16)
+#  ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+        png_set_scale_16(png_ptr);
+#  else
+        png_set_strip_16(png_ptr);
+#  endif
+#endif
+        if (iColorType == PNG_COLOR_TYPE_PALETTE)
+            png_set_expand(png_ptr);
+        if (iBitDepth < 8)
+            png_set_expand(png_ptr);
+        if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))
+            png_set_expand(png_ptr);
+        if (iColorType == PNG_COLOR_TYPE_GRAY ||
+            iColorType == PNG_COLOR_TYPE_GRAY_ALPHA)
+            png_set_gray_to_rgb(png_ptr);
+        /* set the background color to draw transparent and alpha images over */
+        if (png_get_bKGD(png_ptr, info_ptr, &pBackground))
+        {
+            png_set_background(png_ptr, pBackground, PNG_BACKGROUND_GAMMA_FILE, 1, 1.0);
+            pBkgColor->red   = (byte) pBackground->red;
+            pBkgColor->green = (byte) pBackground->green;
+            pBkgColor->blue  = (byte) pBackground->blue;
+        }
+        else
+        {
+            pBkgColor = NULL;
+        }
+        /* if required set gamma conversion */
+        if (png_get_gAMA(png_ptr, info_ptr, &dGamma))
+            png_set_gamma(png_ptr, (double) 2.2, dGamma);
+        /* after the transformations are registered, update info_ptr data */
+        png_read_update_info(png_ptr, info_ptr);
+        /* get again width, height and the new bit-depth and color-type */
+        png_get_IHDR(png_ptr, info_ptr, piWidth, piHeight, &iBitDepth,
+            &iColorType, NULL, NULL, NULL);
+        /* row_bytes is the width x number of channels */
+        ulRowBytes = png_get_rowbytes(png_ptr, info_ptr);
+        ulChannels = png_get_channels(png_ptr, info_ptr);
+        *piChannels = ulChannels;
+        /* now we can allocate memory to store the image */
+        if (pbImageData)
+        {
+            free (pbImageData);
+            pbImageData = NULL;
+        }
+        if ((pbImageData = (png_byte *) malloc(ulRowBytes * (*piHeight)
+                            * sizeof(png_byte))) == NULL)
+        {
+            png_error(png_ptr, "Visual PNG: out of memory");
+        }
+        *ppbImageData = pbImageData;
+        /* and allocate memory for an array of row-pointers */
+        if ((ppbRowPointers = (png_bytepp) malloc((*piHeight)
+                            * sizeof(png_bytep))) == NULL)
+        {
+            png_error(png_ptr, "Visual PNG: out of memory");
+        }
+        /* set the individual row-pointers to point at the correct offsets */
+        for (i = 0; i < (*piHeight); i++)
+            ppbRowPointers[i] = pbImageData + i * ulRowBytes;
+        /* now we can go ahead and just read the whole image */
+        png_read_image(png_ptr, ppbRowPointers);
+        /* read the additional chunks in the PNG file (not really needed) */
+        png_read_end(png_ptr, NULL);
+        /* and we're done */
+        free (ppbRowPointers);
+        ppbRowPointers = NULL;
+        /* yepp, done */
+    }
+    Catch (msg)
+    {
+        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+        *ppbImageData = pbImageData = NULL;
+        if(ppbRowPointers)
+            free (ppbRowPointers);
+        fclose(pfFile);
+        return FALSE;
+    }
+    fclose (pfFile);
+    return TRUE;
+}
+BOOL PngSaveImage (PTSTR pstrFileName, png_byte *pDiData,
+                   int iWidth, int iHeight, png_color bkgColor)
+{
+    const int           ciBitDepth = 8;
+    const int           ciChannels = 3;
+    static FILE        *pfFile;
+    png_uint_32         ulRowBytes;
+    static png_byte   **ppbRowPointers = NULL;
+    int                 i;
+    /* open the PNG output file */
+    if (!pstrFileName)
+        return FALSE;
+    if (!(pfFile = fopen(pstrFileName, "wb")))
+        return FALSE;
+    /* prepare the standard PNG structures */
+    png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL,
+      (png_error_ptr)png_cexcept_error, (png_error_ptr)NULL);
+    if (!png_ptr)
+    {
+        fclose(pfFile);
+        return FALSE;
+    }
+    info_ptr = png_create_info_struct(png_ptr);
+    if (!info_ptr) {
+        fclose(pfFile);
+        png_destroy_write_struct(&png_ptr, (png_infopp) NULL);
+        return FALSE;
+    }
+    Try
+    {
+        /* initialize the png structure */
+#ifdef PNG_STDIO_SUPPORTED
+        png_init_io(png_ptr, pfFile);
+#else
+        png_set_write_fn(png_ptr, (png_voidp)pfFile, png_write_data, png_flush);
+#endif
+        /* we're going to write a very simple 3x8-bit RGB image */
+        png_set_IHDR(png_ptr, info_ptr, iWidth, iHeight, ciBitDepth,
+            PNG_COLOR_TYPE_RGB, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE,
+            PNG_FILTER_TYPE_BASE);
+        /* write the file header information */
+        png_write_info(png_ptr, info_ptr);
+        /* swap the BGR pixels in the DiData structure to RGB */
+        png_set_bgr(png_ptr);
+        /* row_bytes is the width x number of channels */
+        ulRowBytes = iWidth * ciChannels;
+        /* we can allocate memory for an array of row-pointers */
+        if ((ppbRowPointers = (png_bytepp) malloc(iHeight * sizeof(png_bytep))) == NULL)
+            Throw "Visualpng: Out of memory";
+        /* set the individual row-pointers to point at the correct offsets */
+        for (i = 0; i < iHeight; i++)
+            ppbRowPointers[i] = pDiData + i * (((ulRowBytes + 3) >> 2) << 2);
+        /* write out the entire image data in one call */
+        png_write_image (png_ptr, ppbRowPointers);
+        /* write the additional chunks to the PNG file (not really needed) */
+        png_write_end(png_ptr, info_ptr);
+        /* and we're done */
+        free (ppbRowPointers);
+        ppbRowPointers = NULL;
+        /* clean up after the write, and free any memory allocated */
+        png_destroy_write_struct(&png_ptr, (png_infopp) NULL);
+        /* yepp, done */
+    }
+    Catch (msg)
+    {
+        png_destroy_write_struct(&png_ptr, (png_infopp) NULL);
+        if(ppbRowPointers)
+            free (ppbRowPointers);
+        fclose(pfFile);
+        return FALSE;
+    }
+    fclose (pfFile);
+    return TRUE;
+}
+#ifndef PNG_STDIO_SUPPORTED
+static void
+png_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
+{
+   png_size_t check;
+   /* fread() returns 0 on error, so it is OK to store this in a png_size_t
+    * instead of an int, which is what fread() actually returns.
+    */
+   check = (png_size_t)fread(data, (png_size_t)1, length,
+      (FILE *)png_ptr->io_ptr);
+   if (check != length)
+   {
+      png_error(png_ptr, "Read Error");
+   }
+}
+static void
+png_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
+{
+   png_uint_32 check;
+   check = fwrite(data, 1, length, (FILE *)(png_ptr->io_ptr));
+   if (check != length)
+   {
+      png_error(png_ptr, "Write Error");
+   }
+}
+static void
+png_flush(png_structp png_ptr)
+{
+   FILE *io_ptr;
+   io_ptr = (FILE *)CVT_PTR((png_ptr->io_ptr));
+   if (io_ptr != NULL)
+      fflush(io_ptr);
+}
+#endif
+/*-----------------
+ *  end of source
+ *-----------------
+ */
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/visupng/PngFile.h b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/visupng/PngFile.h
new file mode 100644
index 0000000..66f8472
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/visupng/PngFile.h
@@ -0,0 +1,30 @@
+/*------------------------------------------*/
+/*  PNGFILE.H -- Header File for pngfile.c*/
+/*------------------------------------------*/
+/* Copyright 2000, Willem van Schaik.*/
+/* This code is released under the libpng license.*/
+/* For conditions of distribution and use, see the disclaimer*/
+/* and license in png.h*/
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <windows.h>
+void PngFileInitialize (HWND hwnd) ;
+BOOL PngFileOpenDlg (HWND hwnd, PTSTR pstrFileName, PTSTR pstrTitleName) ;
+BOOL PngFileSaveDlg (HWND hwnd, PTSTR pstrFileName, PTSTR pstrTitleName) ;
+BOOL PngLoadImage (PTSTR pstrFileName, png_byte **ppbImageData, 
+                   int *piWidth, int *piHeight, int *piChannels, png_color *pBkgColor);
+BOOL PngSaveImage (PTSTR pstrFileName, png_byte *pDiData,
+                   int iWidth, int iHeight, png_color BkgColor);
+#ifndef PNG_STDIO_SUPPORTED
+static void png_read_data(png_structp png_ptr, png_bytep data, png_size_t length);
+static void png_write_data(png_structp png_ptr, png_bytep data, png_size_t length);
+static void png_flush(png_structp png_ptr);
+#endif
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/visupng/README.txt b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/visupng/README.txt
new file mode 100644
index 0000000..7291bb2
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/visupng/README.txt
@@ -0,0 +1,61 @@
+Microsoft Developer Studio Build File, Format Version 6.00 for VisualPng
+------------------------------------------------------------------------
+Copyright 2000, Willem van Schaik.
+This code is released under the libpng license.
+For conditions of distribution and use, see the disclaimer
+and license in png.h
+As a PNG .dll demo VisualPng is finished. More features would only hinder
+the program's objective. However, further extensions (like support for other
+graphics formats) are in development. To get these, or for pre-compiled
+binaries, go to "http://www.schaik.com/png/visualpng.html".
+------------------------------------------------------------------------
+Assumes that
+   libpng DLLs and LIBs are in ..\..\projects\msvc\win32\libpng
+   zlib DLLs and LIBs are in   ..\..\projects\msvc\win32\zlib
+   libpng header files are in  ..\..\..\libpng
+   zlib header files are in    ..\..\..\zlib
+   the pngsuite images are in  ..\pngsuite
+To build:
+1) On the main menu Select "Build|Set Active configuration".
+   Choose the configuration that corresponds to the library you want to test.
+   This library must have been built using the libpng MS project located in
+   the "..\..\mscv" subdirectory.
+2) Select "Build|Clean"
+3) Select "Build|Rebuild All"
+4) After compiling and linking VisualPng will be started to view an image
+   from the PngSuite directory.  Press Ctrl-N (and Ctrl-V) for other images.
+To install:
+When distributing VisualPng (or a further development) the following options
+are available:
+1) Build the program with the configuration "Win32 LIB" and you only need to
+   include the executable from the ./lib directory in your distribution.
+2) Build the program with the configuration "Win32 DLL" and you need to put
+   in your distribution the executable from the ./dll directory and the dll's
+   libpng1.dll, zlib.dll and msvcrt.dll.  These need to be in the user's PATH.
+Willem van Schaik
+Calgary, June 6th 2000
+P.S. VisualPng was written based on preliminary work of:
+    - Simon-Pierre Cadieux
+    - Glenn Randers-Pehrson
+    - Greg Roelofs
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/visupng/VisualPng.c b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/visupng/VisualPng.c
new file mode 100644
index 0000000..e672ce0
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/visupng/VisualPng.c
@@ -0,0 +1,969 @@
+/*------------------------------------
+ *  VisualPng.C -- Shows a PNG image
+ *------------------------------------
+ *
+ * Copyright 2000, Willem van Schaik.
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+/* switches */
+/* defines */
+#define PROGNAME  "VisualPng"
+#define LONGNAME  "Win32 Viewer for PNG-files"
+#define VERSION   "1.0 of 2000 June 07"
+/* constants */
+#define MARGIN 8
+/* standard includes */
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <windows.h>
+/* application includes */
+#include "png.h"
+#include "pngfile.h"
+#include "resource.h"
+/* macros */
+/* function prototypes */
+LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM);
+BOOL    CALLBACK AboutDlgProc (HWND, UINT, WPARAM, LPARAM) ;
+BOOL CenterAbout (HWND hwndChild, HWND hwndParent);
+BOOL BuildPngList (PTSTR pstrPathName, TCHAR **ppFileList, int *pFileCount,
+        int *pFileIndex);
+BOOL SearchPngList (TCHAR *pFileList, int FileCount, int *pFileIndex,
+        PTSTR pstrPrevName, PTSTR pstrNextName);
+BOOL LoadImageFile(HWND hwnd, PTSTR pstrPathName,
+        png_byte **ppbImage, int *pxImgSize, int *pyImgSize, int *piChannels,
+        png_color *pBkgColor);
+BOOL DisplayImage (HWND hwnd, BYTE **ppDib,
+        BYTE **ppDiData, int cxWinSize, int cyWinSize,
+        BYTE *pbImage, int cxImgSize, int cyImgSize, int cImgChannels,
+        BOOL bStretched);
+BOOL InitBitmap (
+        BYTE *pDiData, int cxWinSize, int cyWinSize);
+BOOL FillBitmap (
+        BYTE *pDiData, int cxWinSize, int cyWinSize,
+        BYTE *pbImage, int cxImgSize, int cyImgSize, int cImgChannels,
+        BOOL bStretched);
+/* a few global variables */
+static char *szProgName = PROGNAME;
+static char *szAppName = LONGNAME;
+static char *szIconName = PROGNAME;
+static char szCmdFileName [MAX_PATH];
+/* MAIN routine */
+int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
+                    PSTR szCmdLine, int iCmdShow)
+{
+    HACCEL   hAccel;
+    HWND     hwnd;
+    MSG      msg;
+    WNDCLASS wndclass;
+    int ixBorders, iyBorders;
+    wndclass.style         = CS_HREDRAW | CS_VREDRAW;
+    wndclass.lpfnWndProc   = WndProc;
+    wndclass.cbClsExtra    = 0;
+    wndclass.cbWndExtra    = 0;
+    wndclass.hInstance     = hInstance;
+    wndclass.hIcon         = LoadIcon (hInstance, szIconName) ;
+    wndclass.hCursor       = LoadCursor (NULL, IDC_ARROW);
+    wndclass.hbrBackground = NULL; /* (HBRUSH) GetStockObject (GRAY_BRUSH); */
+    wndclass.lpszMenuName  = szProgName;
+    wndclass.lpszClassName = szProgName;
+    if (!RegisterClass (&wndclass))
+    {
+        MessageBox (NULL, TEXT ("Error: this program requires Windows NT!"),
+            szProgName, MB_ICONERROR);
+        return 0;
+    }
+    /* if filename given on commandline, store it */
+    if ((szCmdLine != NULL) && (*szCmdLine != '\0'))
+        if (szCmdLine[0] == '"')
+            strncpy (szCmdFileName, szCmdLine + 1, strlen(szCmdLine) - 2);
+        else
+            strcpy (szCmdFileName, szCmdLine);
+    else
+        strcpy (szCmdFileName, "");
+    /* calculate size of window-borders */
+    ixBorders = 2 * (GetSystemMetrics (SM_CXBORDER) +
+                     GetSystemMetrics (SM_CXDLGFRAME));
+    iyBorders = 2 * (GetSystemMetrics (SM_CYBORDER) +
+                     GetSystemMetrics (SM_CYDLGFRAME)) +
+                     GetSystemMetrics (SM_CYCAPTION) +
+                     GetSystemMetrics (SM_CYMENUSIZE) +
+                     1; /* WvS: don't ask me why?  */
+    hwnd = CreateWindow (szProgName, szAppName,
+        WS_OVERLAPPEDWINDOW,
+        CW_USEDEFAULT, CW_USEDEFAULT,
+        512 + 2 * MARGIN + ixBorders, 384 + 2 * MARGIN + iyBorders,
+/*      CW_USEDEFAULT, CW_USEDEFAULT, */
+        NULL, NULL, hInstance, NULL);
+    ShowWindow (hwnd, iCmdShow);
+    UpdateWindow (hwnd);
+    hAccel = LoadAccelerators (hInstance, szProgName);
+    while (GetMessage (&msg, NULL, 0, 0))
+    {
+        if (!TranslateAccelerator (hwnd, hAccel, &msg))
+        {
+            TranslateMessage (&msg);
+            DispatchMessage (&msg);
+        }
+    }
+    return msg.wParam;
+}
+LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam,
+        LPARAM lParam)
+{
+    static HINSTANCE          hInstance ;
+    static HDC                hdc;
+    static PAINTSTRUCT        ps;
+    static HMENU              hMenu;
+    static BITMAPFILEHEADER  *pbmfh;
+    static BITMAPINFOHEADER  *pbmih;
+    static BYTE              *pbImage;
+    static int                cxWinSize, cyWinSize;
+    static int                cxImgSize, cyImgSize;
+    static int                cImgChannels;
+    static png_color          bkgColor = {127, 127, 127};
+    static BOOL               bStretched = TRUE;
+    static BYTE              *pDib = NULL;
+    static BYTE              *pDiData = NULL;
+    static TCHAR              szImgPathName [MAX_PATH];
+    static TCHAR              szTitleName [MAX_PATH];
+    static TCHAR             *pPngFileList = NULL;
+    static int                iPngFileCount;
+    static int                iPngFileIndex;
+    BOOL                      bOk;
+    switch (message)
+    {
+    case WM_CREATE:
+        hInstance = ((LPCREATESTRUCT) lParam)->hInstance ;
+        PngFileInitialize (hwnd);
+        strcpy (szImgPathName, "");
+        /* in case we process file given on command-line */
+        if (szCmdFileName[0] != '\0')
+        {
+            strcpy (szImgPathName, szCmdFileName);
+            /* read the other png-files in the directory for later */
+            /* next/previous commands */
+            BuildPngList (szImgPathName, &pPngFileList, &iPngFileCount,
+                          &iPngFileIndex);
+            /* load the image from file */
+            if (!LoadImageFile (hwnd, szImgPathName,
+                &pbImage, &cxImgSize, &cyImgSize, &cImgChannels, &bkgColor))
+                return 0;
+            /* invalidate the client area for later update */
+            InvalidateRect (hwnd, NULL, TRUE);
+            /* display the PNG into the DIBitmap */
+            DisplayImage (hwnd, &pDib, &pDiData, cxWinSize, cyWinSize,
+                pbImage, cxImgSize, cyImgSize, cImgChannels, bStretched);
+        }
+        return 0;
+    case WM_SIZE:
+        cxWinSize = LOWORD (lParam);
+        cyWinSize = HIWORD (lParam);
+        /* invalidate the client area for later update */
+        InvalidateRect (hwnd, NULL, TRUE);
+        /* display the PNG into the DIBitmap */
+        DisplayImage (hwnd, &pDib, &pDiData, cxWinSize, cyWinSize,
+            pbImage, cxImgSize, cyImgSize, cImgChannels, bStretched);
+        return 0;
+    case WM_INITMENUPOPUP:
+        hMenu = GetMenu (hwnd);
+        if (pbImage)
+            EnableMenuItem (hMenu, IDM_FILE_SAVE, MF_ENABLED);
+        else
+            EnableMenuItem (hMenu, IDM_FILE_SAVE, MF_GRAYED);
+        return 0;
+    case WM_COMMAND:
+        hMenu = GetMenu (hwnd);
+        switch (LOWORD (wParam))
+        {
+        case IDM_FILE_OPEN:
+            /* show the File Open dialog box */
+            if (!PngFileOpenDlg (hwnd, szImgPathName, szTitleName))
+                return 0;
+            /* read the other png-files in the directory for later */
+            /* next/previous commands */
+            BuildPngList (szImgPathName, &pPngFileList, &iPngFileCount,
+                          &iPngFileIndex);
+            /* load the image from file */
+            if (!LoadImageFile (hwnd, szImgPathName,
+                &pbImage, &cxImgSize, &cyImgSize, &cImgChannels, &bkgColor))
+                return 0;
+            /* invalidate the client area for later update */
+            InvalidateRect (hwnd, NULL, TRUE);
+            /* display the PNG into the DIBitmap */
+            DisplayImage (hwnd, &pDib, &pDiData, cxWinSize, cyWinSize,
+                pbImage, cxImgSize, cyImgSize, cImgChannels, bStretched);
+            return 0;
+        case IDM_FILE_SAVE:
+            /* show the File Save dialog box */
+            if (!PngFileSaveDlg (hwnd, szImgPathName, szTitleName))
+                return 0;
+            /* save the PNG to a disk file */
+            SetCursor (LoadCursor (NULL, IDC_WAIT));
+            ShowCursor (TRUE);
+            bOk = PngSaveImage (szImgPathName, pDiData, cxWinSize, cyWinSize,
+                  bkgColor);
+            ShowCursor (FALSE);
+            SetCursor (LoadCursor (NULL, IDC_ARROW));
+            if (!bOk)
+                MessageBox (hwnd, TEXT ("Error in saving the PNG image"),
+                szProgName, MB_ICONEXCLAMATION | MB_OK);
+            return 0;
+        case IDM_FILE_NEXT:
+            /* read next entry in the directory */
+            if (SearchPngList (pPngFileList, iPngFileCount, &iPngFileIndex,
+                NULL, szImgPathName))
+            {
+                if (strcmp (szImgPathName, "") == 0)
+                    return 0;
+                /* load the image from file */
+                if (!LoadImageFile (hwnd, szImgPathName, &pbImage,
+                        &cxImgSize, &cyImgSize, &cImgChannels, &bkgColor))
+                    return 0;
+                /* invalidate the client area for later update */
+                InvalidateRect (hwnd, NULL, TRUE);
+                /* display the PNG into the DIBitmap */
+                DisplayImage (hwnd, &pDib, &pDiData, cxWinSize, cyWinSize,
+                    pbImage, cxImgSize, cyImgSize, cImgChannels, bStretched);
+            }
+            return 0;
+        case IDM_FILE_PREVIOUS:
+            /* read previous entry in the directory */
+            if (SearchPngList (pPngFileList, iPngFileCount, &iPngFileIndex,
+                szImgPathName, NULL))
+            {
+                if (strcmp (szImgPathName, "") == 0)
+                    return 0;
+                /* load the image from file */
+                if (!LoadImageFile (hwnd, szImgPathName, &pbImage, &cxImgSize,
+                    &cyImgSize, &cImgChannels, &bkgColor))
+                    return 0;
+                /* invalidate the client area for later update */
+                InvalidateRect (hwnd, NULL, TRUE);
+                /* display the PNG into the DIBitmap */
+                DisplayImage (hwnd, &pDib, &pDiData, cxWinSize, cyWinSize,
+                    pbImage, cxImgSize, cyImgSize, cImgChannels, bStretched);
+            }
+            return 0;
+        case IDM_FILE_EXIT:
+            /* more cleanup needed... */
+            /* free image buffer */
+            if (pDib != NULL)
+            {
+                free (pDib);
+                pDib = NULL;
+            }
+            /* free file-list */
+            if (pPngFileList != NULL)
+            {
+                free (pPngFileList);
+                pPngFileList = NULL;
+            }
+            /* let's go ... */
+            exit (0);
+            return 0;
+        case IDM_OPTIONS_STRETCH:
+            bStretched = !bStretched;
+            if (bStretched)
+                CheckMenuItem (hMenu, IDM_OPTIONS_STRETCH, MF_CHECKED);
+            else
+                CheckMenuItem (hMenu, IDM_OPTIONS_STRETCH, MF_UNCHECKED);
+            /* invalidate the client area for later update */
+            InvalidateRect (hwnd, NULL, TRUE);
+            /* display the PNG into the DIBitmap */
+            DisplayImage (hwnd, &pDib, &pDiData, cxWinSize, cyWinSize,
+                pbImage, cxImgSize, cyImgSize, cImgChannels, bStretched);
+            return 0;
+        case IDM_HELP_ABOUT:
+            DialogBox (hInstance, TEXT ("AboutBox"), hwnd, AboutDlgProc) ;
+            return 0;
+        } /* end switch */
+        break;
+    case WM_PAINT:
+        hdc = BeginPaint (hwnd, &ps);
+        if (pDib)
+            SetDIBitsToDevice (hdc, 0, 0, cxWinSize, cyWinSize, 0, 0,
+                0, cyWinSize, pDiData, (BITMAPINFO *) pDib, DIB_RGB_COLORS);
+        EndPaint (hwnd, &ps);
+        return 0;
+    case WM_DESTROY:
+        if (pbmfh)
+        {
+            free (pbmfh);
+            pbmfh = NULL;
+        }
+        PostQuitMessage (0);
+        return 0;
+    }
+    return DefWindowProc (hwnd, message, wParam, lParam);
+}
+BOOL CALLBACK AboutDlgProc (HWND hDlg, UINT message,
+                            WPARAM wParam, LPARAM lParam)
+{
+     switch (message)
+     {
+     case WM_INITDIALOG :
+          ShowWindow (hDlg, SW_HIDE);
+          CenterAbout (hDlg, GetWindow (hDlg, GW_OWNER));
+          ShowWindow (hDlg, SW_SHOW);
+          return TRUE ;
+     case WM_COMMAND :
+          switch (LOWORD (wParam))
+          {
+          case IDOK :
+          case IDCANCEL :
+               EndDialog (hDlg, 0) ;
+               return TRUE ;
+          }
+          break ;
+     }
+     return FALSE ;
+}
+/*---------------
+ *  CenterAbout
+ *---------------
+ */
+BOOL CenterAbout (HWND hwndChild, HWND hwndParent)
+{
+   RECT    rChild, rParent, rWorkArea;
+   int     wChild, hChild, wParent, hParent;
+   int     xNew, yNew;
+   BOOL  bResult;
+   /* Get the Height and Width of the child window */
+   GetWindowRect (hwndChild, &rChild);
+   wChild = rChild.right - rChild.left;
+   hChild = rChild.bottom - rChild.top;
+   /* Get the Height and Width of the parent window */
+   GetWindowRect (hwndParent, &rParent);
+   wParent = rParent.right - rParent.left;
+   hParent = rParent.bottom - rParent.top;
+   /* Get the limits of the 'workarea' */
+   bResult = SystemParametersInfo(
+      SPI_GETWORKAREA,  /* system parameter to query or set */
+      sizeof(RECT),
+      &rWorkArea,
+      0);
+   if (!bResult) {
+      rWorkArea.left = rWorkArea.top = 0;
+      rWorkArea.right = GetSystemMetrics(SM_CXSCREEN);
+      rWorkArea.bottom = GetSystemMetrics(SM_CYSCREEN);
+   }
+   /* Calculate new X position, then adjust for workarea */
+   xNew = rParent.left + ((wParent - wChild) /2);
+   if (xNew < rWorkArea.left) {
+      xNew = rWorkArea.left;
+   } else if ((xNew+wChild) > rWorkArea.right) {
+      xNew = rWorkArea.right - wChild;
+   }
+   /* Calculate new Y position, then adjust for workarea */
+   yNew = rParent.top  + ((hParent - hChild) /2);
+   if (yNew < rWorkArea.top) {
+      yNew = rWorkArea.top;
+   } else if ((yNew+hChild) > rWorkArea.bottom) {
+      yNew = rWorkArea.bottom - hChild;
+   }
+   /* Set it, and return */
+   return SetWindowPos (hwndChild, NULL, xNew, yNew, 0, 0, SWP_NOSIZE |
+          SWP_NOZORDER);
+}
+/*----------------
+ *  BuildPngList
+ *----------------
+ */
+BOOL BuildPngList (PTSTR pstrPathName, TCHAR **ppFileList, int *pFileCount,
+     int *pFileIndex)
+{
+    static TCHAR              szImgPathName [MAX_PATH];
+    static TCHAR              szImgFileName [MAX_PATH];
+    static TCHAR              szImgFindName [MAX_PATH];
+    WIN32_FIND_DATA           finddata;
+    HANDLE                    hFind;
+    static TCHAR              szTmp [MAX_PATH];
+    BOOL                      bOk;
+    int                       i, ii;
+    int                       j, jj;
+    /* free previous file-list */
+    if (*ppFileList != NULL)
+    {
+        free (*ppFileList);
+        *ppFileList = NULL;
+    }
+    /* extract foldername, filename and search-name */
+    strcpy (szImgPathName, pstrPathName);
+    strcpy (szImgFileName, strrchr (pstrPathName, '\\') + 1);
+    strcpy (szImgFindName, szImgPathName);
+    *(strrchr (szImgFindName, '\\') + 1) = '\0';
+    strcat (szImgFindName, "*.png");
+    /* first cycle: count number of files in directory for memory allocation */
+    *pFileCount = 0;
+    hFind = FindFirstFile(szImgFindName, &finddata);
+    bOk = (hFind != (HANDLE) -1);
+    while (bOk)
+    {
+        *pFileCount += 1;
+        bOk = FindNextFile(hFind, &finddata);
+    }
+    FindClose(hFind);
+    /* allocation memory for file-list */
+    *ppFileList = (TCHAR *) malloc (*pFileCount * MAX_PATH);
+    /* second cycle: read directory and store filenames in file-list */
+    hFind = FindFirstFile(szImgFindName, &finddata);
+    bOk = (hFind != (HANDLE) -1);
+    i = 0;
+    ii = 0;
+    while (bOk)
+    {
+        strcpy (*ppFileList + ii, szImgPathName);
+        strcpy (strrchr(*ppFileList + ii, '\\') + 1, finddata.cFileName);
+        if (strcmp(pstrPathName, *ppFileList + ii) == 0)
+            *pFileIndex = i;
+        ii += MAX_PATH;
+        i++;
+        bOk = FindNextFile(hFind, &finddata);
+    }
+    FindClose(hFind);
+    /* finally we must sort the file-list */
+    for (i = 0; i < *pFileCount - 1; i++)
+    {
+        ii = i * MAX_PATH;
+        for (j = i+1; j < *pFileCount; j++)
+        {
+            jj = j * MAX_PATH;
+            if (strcmp (*ppFileList + ii, *ppFileList + jj) > 0)
+            {
+                strcpy (szTmp, *ppFileList + jj);
+                strcpy (*ppFileList + jj, *ppFileList + ii);
+                strcpy (*ppFileList + ii, szTmp);
+                /* check if this was the current image that we moved */
+                if (*pFileIndex == i)
+                    *pFileIndex = j;
+                else
+                    if (*pFileIndex == j)
+                        *pFileIndex = i;
+            }
+        }
+    }
+    return TRUE;
+}
+/*----------------
+ *  SearchPngList
+ *----------------
+ */
+BOOL SearchPngList (
+        TCHAR *pFileList, int FileCount, int *pFileIndex,
+        PTSTR pstrPrevName, PTSTR pstrNextName)
+{
+    if (FileCount > 0)
+    {
+        /* get previous entry */
+        if (pstrPrevName != NULL)
+        {
+            if (*pFileIndex > 0)
+                *pFileIndex -= 1;
+            else
+                *pFileIndex = FileCount - 1;
+            strcpy (pstrPrevName, pFileList + (*pFileIndex * MAX_PATH));
+        }
+        /* get next entry */
+        if (pstrNextName != NULL)
+        {
+            if (*pFileIndex < FileCount - 1)
+                *pFileIndex += 1;
+            else
+                *pFileIndex = 0;
+            strcpy (pstrNextName, pFileList + (*pFileIndex * MAX_PATH));
+        }
+        return TRUE;
+    }
+    else
+    {
+        return FALSE;
+    }
+}
+/*-----------------
+ *  LoadImageFile
+ *-----------------
+ */
+BOOL LoadImageFile (HWND hwnd, PTSTR pstrPathName,
+                png_byte **ppbImage, int *pxImgSize, int *pyImgSize,
+                int *piChannels, png_color *pBkgColor)
+{
+    static TCHAR szTmp [MAX_PATH];
+    /* if there's an existing PNG, free the memory */
+    if (*ppbImage)
+    {
+        free (*ppbImage);
+        *ppbImage = NULL;
+    }
+    /* Load the entire PNG into memory */
+    SetCursor (LoadCursor (NULL, IDC_WAIT));
+    ShowCursor (TRUE);
+    PngLoadImage (pstrPathName, ppbImage, pxImgSize, pyImgSize, piChannels,
+                  pBkgColor);
+    ShowCursor (FALSE);
+    SetCursor (LoadCursor (NULL, IDC_ARROW));
+    if (*ppbImage != NULL)
+    {
+        sprintf (szTmp, "VisualPng - %s", strrchr(pstrPathName, '\\') + 1);
+        SetWindowText (hwnd, szTmp);
+    }
+    else
+    {
+        MessageBox (hwnd, TEXT ("Error in loading the PNG image"),
+            szProgName, MB_ICONEXCLAMATION | MB_OK);
+        return FALSE;
+    }
+    return TRUE;
+}
+/*----------------
+ *  DisplayImage
+ *----------------
+ */
+BOOL DisplayImage (HWND hwnd, BYTE **ppDib,
+        BYTE **ppDiData, int cxWinSize, int cyWinSize,
+        BYTE *pbImage, int cxImgSize, int cyImgSize, int cImgChannels,
+        BOOL bStretched)
+{
+    BYTE                       *pDib = *ppDib;
+    BYTE                       *pDiData = *ppDiData;
+    /* BITMAPFILEHEADER        *pbmfh; */
+    BITMAPINFOHEADER           *pbmih;
+    WORD                        wDIRowBytes;
+    png_color                   bkgBlack = {0, 0, 0};
+    png_color                   bkgGray  = {127, 127, 127};
+    png_color                   bkgWhite = {255, 255, 255};
+    /* allocate memory for the Device Independant bitmap */
+    wDIRowBytes = (WORD) ((3 * cxWinSize + 3L) >> 2) << 2;
+    if (pDib)
+    {
+        free (pDib);
+        pDib = NULL;
+    }
+    if (!(pDib = (BYTE *) malloc (sizeof(BITMAPINFOHEADER) +
+        wDIRowBytes * cyWinSize)))
+    {
+        MessageBox (hwnd, TEXT ("Error in displaying the PNG image"),
+            szProgName, MB_ICONEXCLAMATION | MB_OK);
+        *ppDib = pDib = NULL;
+        return FALSE;
+    }
+    *ppDib = pDib;
+    memset (pDib, 0, sizeof(BITMAPINFOHEADER));
+    /* initialize the dib-structure */
+    pbmih = (BITMAPINFOHEADER *) pDib;
+    pbmih->biSize = sizeof(BITMAPINFOHEADER);
+    pbmih->biWidth = cxWinSize;
+    pbmih->biHeight = -((long) cyWinSize);
+    pbmih->biPlanes = 1;
+    pbmih->biBitCount = 24;
+    pbmih->biCompression = 0;
+    pDiData = pDib + sizeof(BITMAPINFOHEADER);
+    *ppDiData = pDiData;
+    /* first fill bitmap with gray and image border */
+    InitBitmap (pDiData, cxWinSize, cyWinSize);
+    /* then fill bitmap with image */
+    if (pbImage)
+    {
+        FillBitmap (
+            pDiData, cxWinSize, cyWinSize,
+            pbImage, cxImgSize, cyImgSize, cImgChannels,
+            bStretched);
+    }
+    return TRUE;
+}
+/*--------------
+ *  InitBitmap
+ *--------------
+ */
+BOOL InitBitmap (BYTE *pDiData, int cxWinSize, int cyWinSize)
+{
+    BYTE *dst;
+    int x, y, col;
+    /* initialize the background with gray */
+    dst = pDiData;
+    for (y = 0; y < cyWinSize; y++)
+    {
+        col = 0;
+        for (x = 0; x < cxWinSize; x++)
+        {
+            /* fill with GRAY */
+            *dst++ = 127;
+            *dst++ = 127;
+            *dst++ = 127;
+            col += 3;
+        }
+        /* rows start on 4 byte boundaries */
+        while ((col % 4) != 0)
+        {
+            dst++;
+            col++;
+        }
+    }
+    return TRUE;
+}
+/*--------------
+ *  FillBitmap
+ *--------------
+ */
+BOOL FillBitmap (
+        BYTE *pDiData, int cxWinSize, int cyWinSize,
+        BYTE *pbImage, int cxImgSize, int cyImgSize, int cImgChannels,
+        BOOL bStretched)
+{
+    BYTE *pStretchedImage;
+    BYTE *pImg;
+    BYTE *src, *dst;
+    BYTE r, g, b, a;
+    const int cDIChannels = 3;
+    WORD wImgRowBytes;
+    WORD wDIRowBytes;
+    int cxNewSize, cyNewSize;
+    int cxImgPos, cyImgPos;
+    int xImg, yImg;
+    int xWin, yWin;
+    int xOld, yOld;
+    int xNew, yNew;
+    if (bStretched)
+    {
+        cxNewSize = cxWinSize - 2 * MARGIN;
+        cyNewSize = cyWinSize - 2 * MARGIN;
+        /* stretch the image to it's window determined size */
+        /* the following two are mathematically the same, but the first
+         * has side-effects because of rounding
+         */
+/*      if ((cyNewSize / cxNewSize) > (cyImgSize / cxImgSize)) */
+        if ((cyNewSize * cxImgSize) > (cyImgSize * cxNewSize))
+        {
+            cyNewSize = cxNewSize * cyImgSize / cxImgSize;
+            cxImgPos = MARGIN;
+            cyImgPos = (cyWinSize - cyNewSize) / 2;
+        }
+        else
+        {
+            cxNewSize = cyNewSize * cxImgSize / cyImgSize;
+            cyImgPos = MARGIN;
+            cxImgPos = (cxWinSize - cxNewSize) / 2;
+        }
+        pStretchedImage = malloc (cImgChannels * cxNewSize * cyNewSize);
+        pImg = pStretchedImage;
+        for (yNew = 0; yNew < cyNewSize; yNew++)
+        {
+            yOld = yNew * cyImgSize / cyNewSize;
+            for (xNew = 0; xNew < cxNewSize; xNew++)
+            {
+                xOld = xNew * cxImgSize / cxNewSize;
+                r = *(pbImage + cImgChannels * ((yOld * cxImgSize) + xOld) + 0);
+                g = *(pbImage + cImgChannels * ((yOld * cxImgSize) + xOld) + 1);
+                b = *(pbImage + cImgChannels * ((yOld * cxImgSize) + xOld) + 2);
+                *pImg++ = r;
+                *pImg++ = g;
+                *pImg++ = b;
+                if (cImgChannels == 4)
+                {
+                    a = *(pbImage + cImgChannels * ((yOld * cxImgSize) + xOld)
+                        + 3);
+                    *pImg++ = a;
+                }
+            }
+        }
+        /* calculate row-bytes */
+        wImgRowBytes = cImgChannels * cxNewSize;
+        wDIRowBytes = (WORD) ((cDIChannels * cxWinSize + 3L) >> 2) << 2;
+        /* copy image to screen */
+        for (yImg = 0, yWin = cyImgPos; yImg < cyNewSize; yImg++, yWin++)
+        {
+            if (yWin >= cyWinSize - cyImgPos)
+                break;
+            src = pStretchedImage + yImg * wImgRowBytes;
+            dst = pDiData + yWin * wDIRowBytes + cxImgPos * cDIChannels;
+            for (xImg = 0, xWin = cxImgPos; xImg < cxNewSize; xImg++, xWin++)
+            {
+                if (xWin >= cxWinSize - cxImgPos)
+                    break;
+                r = *src++;
+                g = *src++;
+                b = *src++;
+                *dst++ = b; /* note the reverse order  */
+                *dst++ = g;
+                *dst++ = r;
+                if (cImgChannels == 4)
+                {
+                    a = *src++;
+                }
+            }
+        }
+        /* free memory */
+        if (pStretchedImage != NULL)
+        {
+            free (pStretchedImage);
+            pStretchedImage = NULL;
+        }
+    }
+    /* process the image not-stretched */
+    else
+    {
+        /* calculate the central position */
+        cxImgPos = (cxWinSize - cxImgSize) / 2;
+        cyImgPos = (cyWinSize - cyImgSize) / 2;
+        /* check for image larger than window */
+        if (cxImgPos < MARGIN)
+            cxImgPos = MARGIN;
+        if (cyImgPos < MARGIN)
+            cyImgPos = MARGIN;
+        /* calculate both row-bytes */
+        wImgRowBytes = cImgChannels * cxImgSize;
+        wDIRowBytes = (WORD) ((cDIChannels * cxWinSize + 3L) >> 2) << 2;
+        /* copy image to screen */
+        for (yImg = 0, yWin = cyImgPos; yImg < cyImgSize; yImg++, yWin++)
+        {
+            if (yWin >= cyWinSize - MARGIN)
+                break;
+            src = pbImage + yImg * wImgRowBytes;
+            dst = pDiData + yWin * wDIRowBytes + cxImgPos * cDIChannels;
+            for (xImg = 0, xWin = cxImgPos; xImg < cxImgSize; xImg++, xWin++)
+            {
+                if (xWin >= cxWinSize - MARGIN)
+                    break;
+                r = *src++;
+                g = *src++;
+                b = *src++;
+                *dst++ = b; /* note the reverse order  */
+                *dst++ = g;
+                *dst++ = r;
+                if (cImgChannels == 4)
+                {
+                    a = *src++;
+                }
+            }
+        }
+    }
+    return TRUE;
+}
+/*-----------------
+ *  end of source
+ *-----------------
+ */
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/visupng/VisualPng.ico b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/visupng/VisualPng.ico
new file mode 100644
index 0000000..68aa371
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/visupng/VisualPng.ico
Binary files differ
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/visupng/VisualPng.png b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/visupng/VisualPng.png
new file mode 100644
index 0000000..c6aa80a
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/visupng/VisualPng.png
Binary files differ
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/visupng/VisualPng.rc b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/visupng/VisualPng.rc
new file mode 100644
index 0000000..6e0623a
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/visupng/VisualPng.rc
@@ -0,0 +1,152 @@
+//Microsoft Developer Studio generated resource script.
+//
+#include "resource.h"
+#define APSTUDIO_READONLY_SYMBOLS
+/////////////////////////////////////////////////////////////////////////////
+//
+// Generated from the TEXTINCLUDE 2 resource.
+//
+#include "afxres.h"
+/////////////////////////////////////////////////////////////////////////////
+#undef APSTUDIO_READONLY_SYMBOLS
+/////////////////////////////////////////////////////////////////////////////
+// English (U.S.) resources
+#if !defined(AFX_RESOURCE_DLL) || defined(AFX_TARG_ENU)
+#ifdef _WIN32
+LANGUAGE LANG_ENGLISH, SUBLANG_ENGLISH_US
+#pragma code_page(1252)
+#endif //_WIN32
+#ifdef APSTUDIO_INVOKED
+/////////////////////////////////////////////////////////////////////////////
+//
+// TEXTINCLUDE
+//
+1 TEXTINCLUDE DISCARDABLE 
+BEGIN
+    "resource.h\0"
+END
+2 TEXTINCLUDE DISCARDABLE 
+BEGIN
+    "#include ""afxres.h""\r\n"
+    "\0"
+END
+3 TEXTINCLUDE DISCARDABLE 
+BEGIN
+    "\r\n"
+    "\0"
+END
+#endif    // APSTUDIO_INVOKED
+/////////////////////////////////////////////////////////////////////////////
+//
+// Menu
+//
+VISUALPNG MENU DISCARDABLE 
+BEGIN
+    POPUP "&File"
+    BEGIN
+        MENUITEM "&Open Image...\tCtrl+O",      IDM_FILE_OPEN
+        MENUITEM "Save &As...",                 IDM_FILE_SAVE
+        MENUITEM SEPARATOR
+        MENUITEM "&Next Image\tCtrl+N",         IDM_FILE_NEXT
+        MENUITEM "Pre&vious Image\tCtrl+V",     IDM_FILE_PREVIOUS
+        MENUITEM SEPARATOR
+        MENUITEM "E&xit\tAlt+X",                IDM_FILE_EXIT
+    END
+    POPUP "&Options"
+    BEGIN
+        MENUITEM "&Stretch",                    IDM_OPTIONS_STRETCH, CHECKED
+    END
+    POPUP "&Help"
+    BEGIN
+        MENUITEM "&About",                      IDM_HELP_ABOUT
+    END
+END
+/////////////////////////////////////////////////////////////////////////////
+//
+// Accelerator
+//
+VISUALPNG ACCELERATORS DISCARDABLE 
+BEGIN
+    "N",            IDM_FILE_NEXT,          VIRTKEY, CONTROL, NOINVERT
+    "O",            IDM_FILE_OPEN,          VIRTKEY, CONTROL, NOINVERT
+    "P",            IDM_FILE_PREVIOUS,      VIRTKEY, CONTROL, NOINVERT
+    "V",            IDM_FILE_PREVIOUS,      VIRTKEY, CONTROL, NOINVERT
+    "X",            IDM_FILE_EXIT,          VIRTKEY, ALT, NOINVERT
+END
+/////////////////////////////////////////////////////////////////////////////
+//
+// Icon
+//
+// Icon with lowest ID value placed first to ensure application icon
+// remains consistent on all systems.
+VISUALPNG               ICON    DISCARDABLE     "VisualPng.ico"
+/////////////////////////////////////////////////////////////////////////////
+//
+// Dialog
+//
+ABOUTBOX DIALOG DISCARDABLE  0, 0, 186, 94
+STYLE DS_MODALFRAME | WS_POPUP
+FONT 8, "MS Sans Serif"
+BEGIN
+    DEFPUSHBUTTON   "OK",IDOK,68,67,50,14
+    CTEXT           "VisualPng 1.0  -  June 2000",IDC_STATIC,49,14,88,8
+    LTEXT           "a PNG image viewer",IDC_STATIC,60,30,66,8
+    LTEXT           "(c) Willem van Schaik, 2000",IDC_STATIC,48,52,90,8
+    LTEXT           "to demonstrate the use of libpng in Visual C",
+                    IDC_STATIC,25,38,136,8
+END
+/////////////////////////////////////////////////////////////////////////////
+//
+// DESIGNINFO
+//
+#ifdef APSTUDIO_INVOKED
+GUIDELINES DESIGNINFO DISCARDABLE 
+BEGIN
+    "ABOUTBOX", DIALOG
+    BEGIN
+        LEFTMARGIN, 7
+        RIGHTMARGIN, 179
+        TOPMARGIN, 7
+        BOTTOMMARGIN, 87
+    END
+END
+#endif    // APSTUDIO_INVOKED
+#endif    // English (U.S.) resources
+/////////////////////////////////////////////////////////////////////////////
+#ifndef APSTUDIO_INVOKED
+/////////////////////////////////////////////////////////////////////////////
+//
+// Generated from the TEXTINCLUDE 3 resource.
+//
+/////////////////////////////////////////////////////////////////////////////
+#endif    // not APSTUDIO_INVOKED
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/visupng/cexcept.h b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/visupng/cexcept.h
new file mode 100644
index 0000000..83c8bfe
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/visupng/cexcept.h
@@ -0,0 +1,248 @@
+/*===
+cexcept.h 2.0.1 (2008-Jul-19-Sat)
+http://www.nicemice.net/cexcept/
+Adam M. Costello
+http://www.nicemice.net/amc/
+An interface for exception-handling in ANSI C (C89 and subsequent ISO
+standards), developed jointly with Cosmin Truta.
+    Copyright (c) 2000-2008 Adam M. Costello and Cosmin Truta.
+    This software may be modified only if its author and version
+    information is updated accurately, and may be redistributed
+    only if accompanied by this unaltered notice.  Subject to those
+    restrictions, permission is granted to anyone to do anything
+    with this software.  The copyright holders make no guarantees
+    regarding this software, and are not responsible for any damage
+    resulting from its use.
+The cexcept interface is not compatible with and cannot interact
+with system exceptions (like division by zero or memory segmentation
+violation), compiler-generated exceptions (like C++ exceptions), or
+other exception-handling interfaces.
+When using this interface across multiple .c files, do not include
+this header file directly.  Instead, create a wrapper header file that
+includes this header file and then invokes the define_exception_type
+macro (see below).  The .c files should then include that header file.
+The interface consists of one type, one well-known name, and six macros.
+define_exception_type(type_name);
+    This macro is used like an external declaration.  It specifies
+    the type of object that gets copied from the exception thrower to
+    the exception catcher.  The type_name can be any type that can be
+    assigned to, that is, a non-constant arithmetic type, struct, union,
+    or pointer.  Examples:
+        define_exception_type(int);
+        enum exception { out_of_memory, bad_arguments, disk_full };
+        define_exception_type(enum exception);
+        struct exception { int code; const char *msg; };
+        define_exception_type(struct exception);
+    Because throwing an exception causes the object to be copied (not
+    just once, but twice), programmers may wish to consider size when
+    choosing the exception type.
+struct exception_context;
+    This type may be used after the define_exception_type() macro has
+    been invoked.  A struct exception_context must be known to both
+    the thrower and the catcher.  It is expected that there be one
+    context for each thread that uses exceptions.  It would certainly
+    be dangerous for multiple threads to access the same context.
+    One thread can use multiple contexts, but that is likely to be
+    confusing and not typically useful.  The application can allocate
+    this structure in any way it pleases--automatic, static, or dynamic.
+    The application programmer should pretend not to know the structure
+    members, which are subject to change.
+struct exception_context *the_exception_context;
+    The Try/Catch and Throw statements (described below) implicitly
+    refer to a context, using the name the_exception_context.  It is
+    the application's responsibility to make sure that this name yields
+    the address of a mutable (non-constant) struct exception_context
+    wherever those statements are used.  Subject to that constraint, the
+    application may declare a variable of this name anywhere it likes
+    (inside a function, in a parameter list, or externally), and may
+    use whatever storage class specifiers (static, extern, etc) or type
+    qualifiers (const, volatile, etc) it likes.  Examples:
+        static struct exception_context
+          * const the_exception_context = &foo;
+        { struct exception_context *the_exception_context = bar; ... }
+        int blah(struct exception_context *the_exception_context, ...);
+        extern struct exception_context the_exception_context[1];
+    The last example illustrates a trick that avoids creating a pointer
+    object separate from the structure object.
+    The name could even be a macro, for example:
+        struct exception_context ec_array[numthreads];
+        #define the_exception_context (ec_array + thread_id)
+    Be aware that the_exception_context is used several times by the
+    Try/Catch/Throw macros, so it shouldn't be expensive or have side
+    effects.  The expansion must be a drop-in replacement for an
+    identifier, so it's safest to put parentheses around it.
+void init_exception_context(struct exception_context *ec);
+    For context structures allocated statically (by an external
+    definition or using the "static" keyword), the implicit
+    initialization to all zeros is sufficient, but contexts allocated
+    by other means must be initialized using this macro before they
+    are used by a Try/Catch statement.  It does no harm to initialize
+    a context more than once (by using this macro on a statically
+    allocated context, or using this macro twice on the same context),
+    but a context must not be re-initialized after it has been used by a
+    Try/Catch statement.
+Try statement
+Catch (expression) statement
+    The Try/Catch/Throw macros are capitalized in order to avoid
+    confusion with the C++ keywords, which have subtly different
+    semantics.
+    A Try/Catch statement has a syntax similar to an if/else statement,
+    except that the parenthesized expression goes after the second
+    keyword rather than the first.  As with if/else, there are two
+    clauses, each of which may be a simple statement ending with a
+    semicolon or a brace-enclosed compound statement.  But whereas
+    the else clause is optional, the Catch clause is required.  The
+    expression must be a modifiable lvalue (something capable of being
+    assigned to) of the same type (disregarding type qualifiers) that
+    was passed to define_exception_type().
+    If a Throw that uses the same exception context as the Try/Catch is
+    executed within the Try clause (typically within a function called
+    by the Try clause), and the exception is not caught by a nested
+    Try/Catch statement, then a copy of the exception will be assigned
+    to the expression, and control will jump to the Catch clause.  If no
+    such Throw is executed, then the assignment is not performed, and
+    the Catch clause is not executed.
+    The expression is not evaluated unless and until the exception is
+    caught, which is significant if it has side effects, for example:
+        Try foo();
+        Catch (p[++i].e) { ... }
+    IMPORTANT: Jumping into or out of a Try clause (for example via
+    return, break, continue, goto, longjmp) is forbidden--the compiler
+    will not complain, but bad things will happen at run-time.  Jumping
+    into or out of a Catch clause is okay, and so is jumping around
+    inside a Try clause.  In many cases where one is tempted to return
+    from a Try clause, it will suffice to use Throw, and then return
+    from the Catch clause.  Another option is to set a flag variable and
+    use goto to jump to the end of the Try clause, then check the flag
+    after the Try/Catch statement.
+    IMPORTANT: The values of any non-volatile automatic variables
+    changed within the Try clause are undefined after an exception is
+    caught.  Therefore, variables modified inside the Try block whose
+    values are needed later outside the Try block must either use static
+    storage or be declared with the "volatile" type qualifier.
+Throw expression;
+    A Throw statement is very much like a return statement, except that
+    the expression is required.  Whereas return jumps back to the place
+    where the current function was called, Throw jumps back to the Catch
+    clause of the innermost enclosing Try clause.  The expression must
+    be compatible with the type passed to define_exception_type().  The
+    exception must be caught, otherwise the program may crash.
+    Slight limitation:  If the expression is a comma-expression, it must
+    be enclosed in parentheses.
+Try statement
+Catch_anonymous statement
+    When the value of the exception is not needed, a Try/Catch statement
+    can use Catch_anonymous instead of Catch (expression).
+Everything below this point is for the benefit of the compiler.  The
+application programmer should pretend not to know any of it, because it
+is subject to change.
+===*/
+#ifndef CEXCEPT_H
+#define CEXCEPT_H
+#include <setjmp.h>
+#define define_exception_type(etype) \
+struct exception_context { \
+  jmp_buf *penv; \
+  int caught; \
+  volatile struct { etype etmp; } v; \
+}
+/* etmp must be volatile because the application might use automatic */
+/* storage for the_exception_context, and etmp is modified between   */
+/* the calls to setjmp() and longjmp().  A wrapper struct is used to */
+/* avoid warnings about a duplicate volatile qualifier in case etype */
+/* already includes it.                                              */
+#define init_exception_context(ec) ((void)((ec)->penv = 0))
+#define Try \
+  { \
+    jmp_buf *exception__prev, exception__env; \
+    exception__prev = the_exception_context->penv; \
+    the_exception_context->penv = &exception__env; \
+    if (setjmp(exception__env) == 0) { \
+      do
+#define exception__catch(action) \
+      while (the_exception_context->caught = 0, \
+             the_exception_context->caught); \
+    } \
+    else { \
+      the_exception_context->caught = 1; \
+    } \
+    the_exception_context->penv = exception__prev; \
+  } \
+  if (!the_exception_context->caught || action) { } \
+  else
+#define Catch(e) exception__catch(((e) = the_exception_context->v.etmp, 0))
+#define Catch_anonymous exception__catch(0)
+/* Try ends with do, and Catch begins with while(0) and ends with     */
+/* else, to ensure that Try/Catch syntax is similar to if/else        */
+/* syntax.                                                            */
+/*                                                                    */
+/* The 0 in while(0) is expressed as x=0,x in order to appease        */
+/* compilers that warn about constant expressions inside while().     */
+/* Most compilers should still recognize that the condition is always */
+/* false and avoid generating code for it.                            */
+#define Throw \
+  for (;; longjmp(*the_exception_context->penv, 1)) \
+    the_exception_context->v.etmp =
+#endif /* CEXCEPT_H */
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/visupng/resource.h b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/visupng/resource.h
new file mode 100644
index 0000000..a06050a
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/visupng/resource.h
@@ -0,0 +1,23 @@
+//{{NO_DEPENDENCIES}}
+// Microsoft Developer Studio generated include file.
+// Used by VisualPng.rc
+//
+#define IDM_FILE_OPEN                   40001
+#define IDM_FILE_SAVE                   40002
+#define IDM_FILE_NEXT                   40003
+#define IDM_FILE_PREVIOUS               40004
+#define IDM_FILE_EXIT                   40005
+#define IDM_OPTIONS_BACKGROUND          40006
+#define IDM_OPTIONS_STRETCH             40007
+#define IDM_HELP_ABOUT                  40008
+// Next default values for new objects
+//
+#ifdef APSTUDIO_INVOKED
+#ifndef APSTUDIO_READONLY_SYMBOLS
+#define _APS_NEXT_RESOURCE_VALUE        113
+#define _APS_NEXT_COMMAND_VALUE         40009
+#define _APS_NEXT_CONTROL_VALUE         1001
+#define _APS_NEXT_SYMED_VALUE           101
+#endif
+#endif
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/example.c b/libraries/irrlicht-1.8/source/Irrlicht/libpng/example.c
new file mode 100644
index 0000000..eb850fe
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/example.c
@@ -0,0 +1,862 @@
+#if 0 /* in case someone actually tries to compile this */
+/* example.c - an example of using libpng
+ * Last changed in libpng 1.5.7 [December 15, 2011]
+ * Maintained 1998-2011 Glenn Randers-Pehrson
+ * Maintained 1996, 1997 Andreas Dilger
+ * Written 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
+ */
+/* This is an example of how to use libpng to read and write PNG files.
+ * The file libpng-manual.txt is much more verbose then this.  If you have not
+ * read it, do so first.  This was designed to be a starting point of an
+ * implementation.  This is not officially part of libpng, is hereby placed
+ * in the public domain, and therefore does not require a copyright notice.
+ * To the extent possible under law, the authors have waived all copyright and
+ * related or neighboring rights to this file.
+ *
+ * This file does not currently compile, because it is missing certain
+ * parts, like allocating memory to hold an image.  You will have to
+ * supply these parts to get it to compile.  For an example of a minimal
+ * working PNG reader/writer, see pngtest.c, included in this distribution;
+ * see also the programs in the contrib directory.
+ */
+#define _POSIX_SOURCE 1  /* libpng and zlib are POSIX-compliant.  You may
+                          * change this if your application uses non-POSIX
+                          * extensions. */
+#include "png.h"
+ /* The png_jmpbuf() macro, used in error handling, became available in
+  * libpng version 1.0.6.  If you want to be able to run your code with older
+  * versions of libpng, you must define the macro yourself (but only if it
+  * is not already defined by libpng!).
+  */
+#ifndef png_jmpbuf
+#  define png_jmpbuf(png_ptr) ((png_ptr)->png_jmpbuf)
+#endif
+/* Check to see if a file is a PNG file using png_sig_cmp().  png_sig_cmp()
+ * returns zero if the image is a PNG and nonzero if it isn't a PNG.
+ *
+ * The function check_if_png() shown here, but not used, returns nonzero (true)
+ * if the file can be opened and is a PNG, 0 (false) otherwise.
+ *
+ * If this call is successful, and you are going to keep the file open,
+ * you should call png_set_sig_bytes(png_ptr, PNG_BYTES_TO_CHECK); once
+ * you have created the png_ptr, so that libpng knows your application
+ * has read that many bytes from the start of the file.  Make sure you
+ * don't call png_set_sig_bytes() with more than 8 bytes read or give it
+ * an incorrect number of bytes read, or you will either have read too
+ * many bytes (your fault), or you are telling libpng to read the wrong
+ * number of magic bytes (also your fault).
+ *
+ * Many applications already read the first 2 or 4 bytes from the start
+ * of the image to determine the file type, so it would be easiest just
+ * to pass the bytes to png_sig_cmp() or even skip that if you know
+ * you have a PNG file, and call png_set_sig_bytes().
+ */
+#define PNG_BYTES_TO_CHECK 4
+int check_if_png(char *file_name, FILE **fp)
+{
+   char buf[PNG_BYTES_TO_CHECK];
+   /* Open the prospective PNG file. */
+   if ((*fp = fopen(file_name, "rb")) == NULL)
+      return 0;
+   /* Read in some of the signature bytes */
+   if (fread(buf, 1, PNG_BYTES_TO_CHECK, *fp) != PNG_BYTES_TO_CHECK)
+      return 0;
+   /* Compare the first PNG_BYTES_TO_CHECK bytes of the signature.
+      Return nonzero (true) if they match */
+   return(!png_sig_cmp(buf, (png_size_t)0, PNG_BYTES_TO_CHECK));
+}
+/* Read a PNG file.  You may want to return an error code if the read
+ * fails (depending upon the failure).  There are two "prototypes" given
+ * here - one where we are given the filename, and we need to open the
+ * file, and the other where we are given an open file (possibly with
+ * some or all of the magic bytes read - see comments above).
+ */
+#ifdef open_file /* prototype 1 */
+void read_png(char *file_name)  /* We need to open the file */
+{
+   png_structp png_ptr;
+   png_infop info_ptr;
+   unsigned int sig_read = 0;
+   png_uint_32 width, height;
+   int bit_depth, color_type, interlace_type;
+   FILE *fp;
+   if ((fp = fopen(file_name, "rb")) == NULL)
+      return (ERROR);
+#else no_open_file /* prototype 2 */
+void read_png(FILE *fp, unsigned int sig_read)  /* File is already open */
+{
+   png_structp png_ptr;
+   png_infop info_ptr;
+   png_uint_32 width, height;
+   int bit_depth, color_type, interlace_type;
+#endif no_open_file /* Only use one prototype! */
+   /* Create and initialize the png_struct with the desired error handler
+    * functions.  If you want to use the default stderr and longjump method,
+    * you can supply NULL for the last three parameters.  We also supply the
+    * the compiler header file version, so that we know if the application
+    * was compiled with a compatible version of the library.  REQUIRED
+    */
+   png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,
+      png_voidp user_error_ptr, user_error_fn, user_warning_fn);
+   if (png_ptr == NULL)
+   {
+      fclose(fp);
+      return (ERROR);
+   }
+   /* Allocate/initialize the memory for image information.  REQUIRED. */
+   info_ptr = png_create_info_struct(png_ptr);
+   if (info_ptr == NULL)
+   {
+      fclose(fp);
+      png_destroy_read_struct(&png_ptr, NULL, NULL);
+      return (ERROR);
+   }
+   /* Set error handling if you are using the setjmp/longjmp method (this is
+    * the normal method of doing things with libpng).  REQUIRED unless you
+    * set up your own error handlers in the png_create_read_struct() earlier.
+    */
+   if (setjmp(png_jmpbuf(png_ptr)))
+   {
+      /* Free all of the memory associated with the png_ptr and info_ptr */
+      png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+      fclose(fp);
+      /* If we get here, we had a problem reading the file */
+      return (ERROR);
+   }
+   /* One of the following I/O initialization methods is REQUIRED */
+#ifdef streams /* PNG file I/O method 1 */
+   /* Set up the input control if you are using standard C streams */
+   png_init_io(png_ptr, fp);
+#else no_streams /* PNG file I/O method 2 */
+   /* If you are using replacement read functions, instead of calling
+    * png_init_io() here you would call:
+    */
+   png_set_read_fn(png_ptr, (void *)user_io_ptr, user_read_fn);
+   /* where user_io_ptr is a structure you want available to the callbacks */
+#endif no_streams /* Use only one I/O method! */
+   /* If we have already read some of the signature */
+   png_set_sig_bytes(png_ptr, sig_read);
+#ifdef hilevel
+   /*
+    * If you have enough memory to read in the entire image at once,
+    * and you need to specify only transforms that can be controlled
+    * with one of the PNG_TRANSFORM_* bits (this presently excludes
+    * quantizing, filling, setting background, and doing gamma
+    * adjustment), then you can read the entire image (including
+    * pixels) into the info structure with this call:
+    */
+   png_read_png(png_ptr, info_ptr, png_transforms, NULL);
+#else
+   /* OK, you're doing it the hard way, with the lower-level functions */
+   /* The call to png_read_info() gives us all of the information from the
+    * PNG file before the first IDAT (image data chunk).  REQUIRED
+    */
+   png_read_info(png_ptr, info_ptr);
+   png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type,
+       &interlace_type, NULL, NULL);
+   /* Set up the data transformations you want.  Note that these are all
+    * optional.  Only call them if you want/need them.  Many of the
+    * transformations only work on specific types of images, and many
+    * are mutually exclusive.
+    */
+   /* Tell libpng to strip 16 bit/color files down to 8 bits/color.
+    * Use accurate scaling if it's available, otherwise just chop off the
+    * low byte.
+    */
+#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+    png_set_scale_16(png_ptr);
+#else
+   png_set_strip_16(png_ptr);
+#endif
+   /* Strip alpha bytes from the input data without combining with the
+    * background (not recommended).
+    */
+   png_set_strip_alpha(png_ptr);
+   /* Extract multiple pixels with bit depths of 1, 2, and 4 from a single
+    * byte into separate bytes (useful for paletted and grayscale images).
+    */
+   png_set_packing(png_ptr);
+   /* Change the order of packed pixels to least significant bit first
+    * (not useful if you are using png_set_packing). */
+   png_set_packswap(png_ptr);
+   /* Expand paletted colors into true RGB triplets */
+   if (color_type == PNG_COLOR_TYPE_PALETTE)
+      png_set_palette_to_rgb(png_ptr);
+   /* Expand grayscale images to the full 8 bits from 1, 2, or 4 bits/pixel */
+   if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8)
+      png_set_expand_gray_1_2_4_to_8(png_ptr);
+   /* Expand paletted or RGB images with transparency to full alpha channels
+    * so the data will be available as RGBA quartets.
+    */
+   if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))
+      png_set_tRNS_to_alpha(png_ptr);
+   /* Set the background color to draw transparent and alpha images over.
+    * It is possible to set the red, green, and blue components directly
+    * for paletted images instead of supplying a palette index.  Note that
+    * even if the PNG file supplies a background, you are not required to
+    * use it - you should use the (solid) application background if it has one.
+    */
+   png_color_16 my_background, *image_background;
+   if (png_get_bKGD(png_ptr, info_ptr, &image_background))
+      png_set_background(png_ptr, image_background,
+                         PNG_BACKGROUND_GAMMA_FILE, 1, 1.0);
+   else
+      png_set_background(png_ptr, &my_background,
+                         PNG_BACKGROUND_GAMMA_SCREEN, 0, 1.0);
+   /* Some suggestions as to how to get a screen gamma value
+    *
+    * Note that screen gamma is the display_exponent, which includes
+    * the CRT_exponent and any correction for viewing conditions
+    */
+   if (/* We have a user-defined screen gamma value */)
+   {
+      screen_gamma = user-defined screen_gamma;
+   }
+   /* This is one way that applications share the same screen gamma value */
+   else if ((gamma_str = getenv("SCREEN_GAMMA")) != NULL)
+   {
+      screen_gamma = atof(gamma_str);
+   }
+   /* If we don't have another value */
+   else
+   {
+      screen_gamma = 2.2;  /* A good guess for a PC monitor in a dimly
+                              lit room */
+      screen_gamma = 1.7 or 1.0;  /* A good guess for Mac systems */
+   }
+   /* Tell libpng to handle the gamma conversion for you.  The final call
+    * is a good guess for PC generated images, but it should be configurable
+    * by the user at run time by the user.  It is strongly suggested that
+    * your application support gamma correction.
+    */
+   int intent;
+   if (png_get_sRGB(png_ptr, info_ptr, &intent))
+      png_set_gamma(png_ptr, screen_gamma, 0.45455);
+   else
+   {
+      double image_gamma;
+      if (png_get_gAMA(png_ptr, info_ptr, &image_gamma))
+         png_set_gamma(png_ptr, screen_gamma, image_gamma);
+      else
+         png_set_gamma(png_ptr, screen_gamma, 0.45455);
+   }
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+   /* Quantize RGB files down to 8 bit palette or reduce palettes
+    * to the number of colors available on your screen.
+    */
+   if (color_type & PNG_COLOR_MASK_COLOR)
+   {
+      int num_palette;
+      png_colorp palette;
+      /* This reduces the image to the application supplied palette */
+      if (/* We have our own palette */)
+      {
+         /* An array of colors to which the image should be quantized */
+         png_color std_color_cube[MAX_SCREEN_COLORS];
+         png_set_quantize(png_ptr, std_color_cube, MAX_SCREEN_COLORS,
+            MAX_SCREEN_COLORS, NULL, 0);
+      }
+      /* This reduces the image to the palette supplied in the file */
+      else if (png_get_PLTE(png_ptr, info_ptr, &palette, &num_palette))
+      {
+         png_uint_16p histogram = NULL;
+         png_get_hIST(png_ptr, info_ptr, &histogram);
+         png_set_quantize(png_ptr, palette, num_palette,
+                        max_screen_colors, histogram, 0);
+      }
+   }
+#endif /* PNG_READ_QUANTIZE_SUPPORTED */
+   /* Invert monochrome files to have 0 as white and 1 as black */
+   png_set_invert_mono(png_ptr);
+   /* If you want to shift the pixel values from the range [0,255] or
+    * [0,65535] to the original [0,7] or [0,31], or whatever range the
+    * colors were originally in:
+    */
+   if (png_get_valid(png_ptr, info_ptr, PNG_INFO_sBIT))
+   {
+      png_color_8p sig_bit_p;
+      png_get_sBIT(png_ptr, info_ptr, &sig_bit_p);
+      png_set_shift(png_ptr, sig_bit_p);
+   }
+   /* Flip the RGB pixels to BGR (or RGBA to BGRA) */
+   if (color_type & PNG_COLOR_MASK_COLOR)
+      png_set_bgr(png_ptr);
+   /* Swap the RGBA or GA data to ARGB or AG (or BGRA to ABGR) */
+   png_set_swap_alpha(png_ptr);
+   /* Swap bytes of 16 bit files to least significant byte first */
+   png_set_swap(png_ptr);
+   /* Add filler (or alpha) byte (before/after each RGB triplet) */
+   png_set_filler(png_ptr, 0xff, PNG_FILLER_AFTER);
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+   /* Turn on interlace handling.  REQUIRED if you are not using
+    * png_read_image().  To see how to handle interlacing passes,
+    * see the png_read_row() method below:
+    */
+   number_passes = png_set_interlace_handling(png_ptr);
+#else
+   number_passes = 1;
+#endif /* PNG_READ_INTERLACING_SUPPORTED */
+   /* Optional call to gamma correct and add the background to the palette
+    * and update info structure.  REQUIRED if you are expecting libpng to
+    * update the palette for you (ie you selected such a transform above).
+    */
+   png_read_update_info(png_ptr, info_ptr);
+   /* Allocate the memory to hold the image using the fields of info_ptr. */
+   /* The easiest way to read the image: */
+   png_bytep row_pointers[height];
+   /* Clear the pointer array */
+   for (row = 0; row < height; row++)
+      row_pointers[row] = NULL;
+   for (row = 0; row < height; row++)
+      row_pointers[row] = png_malloc(png_ptr, png_get_rowbytes(png_ptr,
+         info_ptr));
+   /* Now it's time to read the image.  One of these methods is REQUIRED */
+#ifdef entire /* Read the entire image in one go */
+   png_read_image(png_ptr, row_pointers);
+#else no_entire /* Read the image one or more scanlines at a time */
+   /* The other way to read images - deal with interlacing: */
+   for (pass = 0; pass < number_passes; pass++)
+   {
+#ifdef single /* Read the image a single row at a time */
+      for (y = 0; y < height; y++)
+      {
+         png_read_rows(png_ptr, &row_pointers[y], NULL, 1);
+      }
+#else no_single /* Read the image several rows at a time */
+      for (y = 0; y < height; y += number_of_rows)
+      {
+#ifdef sparkle /* Read the image using the "sparkle" effect. */
+         png_read_rows(png_ptr, &row_pointers[y], NULL,
+            number_of_rows);
+#else no_sparkle /* Read the image using the "rectangle" effect */
+         png_read_rows(png_ptr, NULL, &row_pointers[y],
+            number_of_rows);
+#endif no_sparkle /* Use only one of these two methods */
+      }
+      /* If you want to display the image after every pass, do so here */
+#endif no_single /* Use only one of these two methods */
+   }
+#endif no_entire /* Use only one of these two methods */
+   /* Read rest of file, and get additional chunks in info_ptr - REQUIRED */
+   png_read_end(png_ptr, info_ptr);
+#endif hilevel
+   /* At this point you have read the entire image */
+   /* Clean up after the read, and free any memory allocated - REQUIRED */
+   png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+   /* Close the file */
+   fclose(fp);
+   /* That's it */
+   return (OK);
+}
+/* Progressively read a file */
+int
+initialize_png_reader(png_structp *png_ptr, png_infop *info_ptr)
+{
+   /* Create and initialize the png_struct with the desired error handler
+    * functions.  If you want to use the default stderr and longjump method,
+    * you can supply NULL for the last three parameters.  We also check that
+    * the library version is compatible in case we are using dynamically
+    * linked libraries.
+    */
+   *png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,
+       png_voidp user_error_ptr, user_error_fn, user_warning_fn);
+   if (*png_ptr == NULL)
+   {
+      *info_ptr = NULL;
+      return (ERROR);
+   }
+   *info_ptr = png_create_info_struct(png_ptr);
+   if (*info_ptr == NULL)
+   {
+      png_destroy_read_struct(png_ptr, info_ptr, NULL);
+      return (ERROR);
+   }
+   if (setjmp(png_jmpbuf((*png_ptr))))
+   {
+      png_destroy_read_struct(png_ptr, info_ptr, NULL);
+      return (ERROR);
+   }
+   /* This one's new.  You will need to provide all three
+    * function callbacks, even if you aren't using them all.
+    * If you aren't using all functions, you can specify NULL
+    * parameters.  Even when all three functions are NULL,
+    * you need to call png_set_progressive_read_fn().
+    * These functions shouldn't be dependent on global or
+    * static variables if you are decoding several images
+    * simultaneously.  You should store stream specific data
+    * in a separate struct, given as the second parameter,
+    * and retrieve the pointer from inside the callbacks using
+    * the function png_get_progressive_ptr(png_ptr).
+    */
+   png_set_progressive_read_fn(*png_ptr, (void *)stream_data,
+      info_callback, row_callback, end_callback);
+   return (OK);
+}
+int
+process_data(png_structp *png_ptr, png_infop *info_ptr,
+   png_bytep buffer, png_uint_32 length)
+{
+   if (setjmp(png_jmpbuf((*png_ptr))))
+   {
+      /* Free the png_ptr and info_ptr memory on error */
+      png_destroy_read_struct(png_ptr, info_ptr, NULL);
+      return (ERROR);
+   }
+   /* This one's new also.  Simply give it chunks of data as
+    * they arrive from the data stream (in order, of course).
+    * On segmented machines, don't give it any more than 64K.
+    * The library seems to run fine with sizes of 4K, although
+    * you can give it much less if necessary (I assume you can
+    * give it chunks of 1 byte, but I haven't tried with less
+    * than 256 bytes yet).  When this function returns, you may
+    * want to display any rows that were generated in the row
+    * callback, if you aren't already displaying them there.
+    */
+   png_process_data(*png_ptr, *info_ptr, buffer, length);
+   return (OK);
+}
+info_callback(png_structp png_ptr, png_infop info)
+{
+   /* Do any setup here, including setting any of the transformations
+    * mentioned in the Reading PNG files section.  For now, you _must_
+    * call either png_start_read_image() or png_read_update_info()
+    * after all the transformations are set (even if you don't set
+    * any).  You may start getting rows before png_process_data()
+    * returns, so this is your last chance to prepare for that.
+    */
+}
+row_callback(png_structp png_ptr, png_bytep new_row,
+   png_uint_32 row_num, int pass)
+{
+   /*
+    * This function is called for every row in the image.  If the
+    * image is interlaced, and you turned on the interlace handler,
+    * this function will be called for every row in every pass.
+    *
+    * In this function you will receive a pointer to new row data from
+    * libpng called new_row that is to replace a corresponding row (of
+    * the same data format) in a buffer allocated by your application.
+    *
+    * The new row data pointer "new_row" may be NULL, indicating there is
+    * no new data to be replaced (in cases of interlace loading).
+    *
+    * If new_row is not NULL then you need to call
+    * png_progressive_combine_row() to replace the corresponding row as
+    * shown below:
+    */
+   /* Get pointer to corresponding row in our
+    * PNG read buffer.
+    */
+   png_bytep old_row = ((png_bytep *)our_data)[row_num];
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+   /* If both rows are allocated then copy the new row
+    * data to the corresponding row data.
+    */
+   if ((old_row != NULL) && (new_row != NULL))
+   png_progressive_combine_row(png_ptr, old_row, new_row);
+   /*
+    * The rows and passes are called in order, so you don't really
+    * need the row_num and pass, but I'm supplying them because it
+    * may make your life easier.
+    *
+    * For the non-NULL rows of interlaced images, you must call
+    * png_progressive_combine_row() passing in the new row and the
+    * old row, as demonstrated above.  You can call this function for
+    * NULL rows (it will just return) and for non-interlaced images
+    * (it just does the png_memcpy for you) if it will make the code
+    * easier.  Thus, you can just do this for all cases:
+    */
+   png_progressive_combine_row(png_ptr, old_row, new_row);
+   /* where old_row is what was displayed for previous rows.  Note
+    * that the first pass (pass == 0 really) will completely cover
+    * the old row, so the rows do not have to be initialized.  After
+    * the first pass (and only for interlaced images), you will have
+    * to pass the current row as new_row, and the function will combine
+    * the old row and the new row.
+    */
+#endif /* PNG_READ_INTERLACING_SUPPORTED */
+}
+end_callback(png_structp png_ptr, png_infop info)
+{
+   /* This function is called when the whole image has been read,
+    * including any chunks after the image (up to and including
+    * the IEND).  You will usually have the same info chunk as you
+    * had in the header, although some data may have been added
+    * to the comments and time fields.
+    *
+    * Most people won't do much here, perhaps setting a flag that
+    * marks the image as finished.
+    */
+}
+/* Write a png file */
+void write_png(char *file_name /* , ... other image information ... */)
+{
+   FILE *fp;
+   png_structp png_ptr;
+   png_infop info_ptr;
+   png_colorp palette;
+   /* Open the file */
+   fp = fopen(file_name, "wb");
+   if (fp == NULL)
+      return (ERROR);
+   /* Create and initialize the png_struct with the desired error handler
+    * functions.  If you want to use the default stderr and longjump method,
+    * you can supply NULL for the last three parameters.  We also check that
+    * the library version is compatible with the one used at compile time,
+    * in case we are using dynamically linked libraries.  REQUIRED.
+    */
+   png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING,
+      png_voidp user_error_ptr, user_error_fn, user_warning_fn);
+   if (png_ptr == NULL)
+   {
+      fclose(fp);
+      return (ERROR);
+   }
+   /* Allocate/initialize the image information data.  REQUIRED */
+   info_ptr = png_create_info_struct(png_ptr);
+   if (info_ptr == NULL)
+   {
+      fclose(fp);
+      png_destroy_write_struct(&png_ptr,  NULL);
+      return (ERROR);
+   }
+   /* Set error handling.  REQUIRED if you aren't supplying your own
+    * error handling functions in the png_create_write_struct() call.
+    */
+   if (setjmp(png_jmpbuf(png_ptr)))
+   {
+      /* If we get here, we had a problem writing the file */
+      fclose(fp);
+      png_destroy_write_struct(&png_ptr, &info_ptr);
+      return (ERROR);
+   }
+   /* One of the following I/O initialization functions is REQUIRED */
+#ifdef streams /* I/O initialization method 1 */
+   /* Set up the output control if you are using standard C streams */
+   png_init_io(png_ptr, fp);
+#else no_streams /* I/O initialization method 2 */
+   /* If you are using replacement write functions, instead of calling
+    * png_init_io() here you would call
+    */
+   png_set_write_fn(png_ptr, (void *)user_io_ptr, user_write_fn,
+      user_IO_flush_function);
+   /* where user_io_ptr is a structure you want available to the callbacks */
+#endif no_streams /* Only use one initialization method */
+#ifdef hilevel
+   /* This is the easy way.  Use it if you already have all the
+    * image info living in the structure.  You could "|" many
+    * PNG_TRANSFORM flags into the png_transforms integer here.
+    */
+   png_write_png(png_ptr, info_ptr, png_transforms, NULL);
+#else
+   /* This is the hard way */
+   /* Set the image information here.  Width and height are up to 2^31,
+    * bit_depth is one of 1, 2, 4, 8, or 16, but valid values also depend on
+    * the color_type selected. color_type is one of PNG_COLOR_TYPE_GRAY,
+    * PNG_COLOR_TYPE_GRAY_ALPHA, PNG_COLOR_TYPE_PALETTE, PNG_COLOR_TYPE_RGB,
+    * or PNG_COLOR_TYPE_RGB_ALPHA.  interlace is either PNG_INTERLACE_NONE or
+    * PNG_INTERLACE_ADAM7, and the compression_type and filter_type MUST
+    * currently be PNG_COMPRESSION_TYPE_BASE and PNG_FILTER_TYPE_BASE. REQUIRED
+    */
+   png_set_IHDR(png_ptr, info_ptr, width, height, bit_depth, PNG_COLOR_TYPE_???,
+      PNG_INTERLACE_????, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
+   /* Set the palette if there is one.  REQUIRED for indexed-color images */
+   palette = (png_colorp)png_malloc(png_ptr, PNG_MAX_PALETTE_LENGTH
+             * png_sizeof(png_color));
+   /* ... Set palette colors ... */
+   png_set_PLTE(png_ptr, info_ptr, palette, PNG_MAX_PALETTE_LENGTH);
+   /* You must not free palette here, because png_set_PLTE only makes a link to
+    * the palette that you malloced.  Wait until you are about to destroy
+    * the png structure.
+    */
+   /* Optional significant bit (sBIT) chunk */
+   png_color_8 sig_bit;
+   /* If we are dealing with a grayscale image then */
+   sig_bit.gray = true_bit_depth;
+   /* Otherwise, if we are dealing with a color image then */
+   sig_bit.red = true_red_bit_depth;
+   sig_bit.green = true_green_bit_depth;
+   sig_bit.blue = true_blue_bit_depth;
+   /* If the image has an alpha channel then */
+   sig_bit.alpha = true_alpha_bit_depth;
+   png_set_sBIT(png_ptr, info_ptr, &sig_bit);
+   /* Optional gamma chunk is strongly suggested if you have any guess
+    * as to the correct gamma of the image.
+    */
+   png_set_gAMA(png_ptr, info_ptr, gamma);
+   /* Optionally write comments into the image */
+   text_ptr[0].key = "Title";
+   text_ptr[0].text = "Mona Lisa";
+   text_ptr[0].compression = PNG_TEXT_COMPRESSION_NONE;
+   text_ptr[0].itxt_length = 0;
+   text_ptr[0].lang = NULL;
+   text_ptr[0].lang_key = NULL;
+   text_ptr[1].key = "Author";
+   text_ptr[1].text = "Leonardo DaVinci";
+   text_ptr[1].compression = PNG_TEXT_COMPRESSION_NONE;
+   text_ptr[1].itxt_length = 0;
+   text_ptr[1].lang = NULL;
+   text_ptr[1].lang_key = NULL;
+   text_ptr[2].key = "Description";
+   text_ptr[2].text = "<long text>";
+   text_ptr[2].compression = PNG_TEXT_COMPRESSION_zTXt;
+   text_ptr[2].itxt_length = 0;
+   text_ptr[2].lang = NULL;
+   text_ptr[2].lang_key = NULL;
+   png_set_text(png_ptr, info_ptr, text_ptr, 3);
+   /* Other optional chunks like cHRM, bKGD, tRNS, tIME, oFFs, pHYs */
+   /* Note that if sRGB is present the gAMA and cHRM chunks must be ignored
+    * on read and, if your application chooses to write them, they must
+    * be written in accordance with the sRGB profile
+    */
+   /* Write the file header information.  REQUIRED */
+   png_write_info(png_ptr, info_ptr);
+   /* If you want, you can write the info in two steps, in case you need to
+    * write your private chunk ahead of PLTE:
+    *
+    *   png_write_info_before_PLTE(write_ptr, write_info_ptr);
+    *   write_my_chunk();
+    *   png_write_info(png_ptr, info_ptr);
+    *
+    * However, given the level of known- and unknown-chunk support in 1.2.0
+    * and up, this should no longer be necessary.
+    */
+   /* Once we write out the header, the compression type on the text
+    * chunks gets changed to PNG_TEXT_COMPRESSION_NONE_WR or
+    * PNG_TEXT_COMPRESSION_zTXt_WR, so it doesn't get written out again
+    * at the end.
+    */
+   /* Set up the transformations you want.  Note that these are
+    * all optional.  Only call them if you want them.
+    */
+   /* Invert monochrome pixels */
+   png_set_invert_mono(png_ptr);
+   /* Shift the pixels up to a legal bit depth and fill in
+    * as appropriate to correctly scale the image.
+    */
+   png_set_shift(png_ptr, &sig_bit);
+   /* Pack pixels into bytes */
+   png_set_packing(png_ptr);
+   /* Swap location of alpha bytes from ARGB to RGBA */
+   png_set_swap_alpha(png_ptr);
+   /* Get rid of filler (OR ALPHA) bytes, pack XRGB/RGBX/ARGB/RGBA into
+    * RGB (4 channels -> 3 channels). The second parameter is not used.
+    */
+   png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE);
+   /* Flip BGR pixels to RGB */
+   png_set_bgr(png_ptr);
+   /* Swap bytes of 16-bit files to most significant byte first */
+   png_set_swap(png_ptr);
+   /* Swap bits of 1, 2, 4 bit packed pixel formats */
+   png_set_packswap(png_ptr);
+   /* Turn on interlace handling if you are not using png_write_image() */
+   if (interlacing)
+      number_passes = png_set_interlace_handling(png_ptr);
+   else
+      number_passes = 1;
+   /* The easiest way to write the image (you may have a different memory
+    * layout, however, so choose what fits your needs best).  You need to
+    * use the first method if you aren't handling interlacing yourself.
+    */
+   png_uint_32 k, height, width;
+   png_byte image[height][width*bytes_per_pixel];
+   png_bytep row_pointers[height];
+   if (height > PNG_UINT_32_MAX/png_sizeof(png_bytep))
+     png_error (png_ptr, "Image is too tall to process in memory");
+   for (k = 0; k < height; k++)
+     row_pointers[k] = image + k*width*bytes_per_pixel;
+   /* One of the following output methods is REQUIRED */
+#ifdef entire /* Write out the entire image data in one call */
+   png_write_image(png_ptr, row_pointers);
+   /* The other way to write the image - deal with interlacing */
+#else no_entire /* Write out the image data by one or more scanlines */
+   /* The number of passes is either 1 for non-interlaced images,
+    * or 7 for interlaced images.
+    */
+   for (pass = 0; pass < number_passes; pass++)
+   {
+      /* Write a few rows at a time. */
+      png_write_rows(png_ptr, &row_pointers[first_row], number_of_rows);
+      /* If you are only writing one row at a time, this works */
+      for (y = 0; y < height; y++)
+         png_write_rows(png_ptr, &row_pointers[y], 1);
+   }
+#endif no_entire /* Use only one output method */
+   /* You can write optional chunks like tEXt, zTXt, and tIME at the end
+    * as well.  Shouldn't be necessary in 1.2.0 and up as all the public
+    * chunks are supported and you can use png_set_unknown_chunks() to
+    * register unknown chunks into the info structure to be written out.
+    */
+   /* It is REQUIRED to call this to finish writing the rest of the file */
+   png_write_end(png_ptr, info_ptr);
+#endif hilevel
+   /* If you png_malloced a palette, free it here (don't free info_ptr->palette,
+    * as recommended in versions 1.0.5m and earlier of this example; if
+    * libpng mallocs info_ptr->palette, libpng will free it).  If you
+    * allocated it with malloc() instead of png_malloc(), use free() instead
+    * of png_free().
+    */
+   png_free(png_ptr, palette);
+   palette = NULL;
+   /* Similarly, if you png_malloced any data that you passed in with
+    * png_set_something(), such as a hist or trans array, free it here,
+    * when you can be sure that libpng is through with it.
+    */
+   png_free(png_ptr, trans);
+   trans = NULL;
+   /* Whenever you use png_free() it is a good idea to set the pointer to
+    * NULL in case your application inadvertently tries to png_free() it
+    * again.  When png_free() sees a NULL it returns without action, thus
+    * avoiding the double-free security problem.
+    */
+   /* Clean up after the write, and free any memory allocated */
+   png_destroy_write_struct(&png_ptr, &info_ptr);
+   /* Close the file */
+   fclose(fp);
+   /* That's it */
+   return (OK);
+}
+#endif /* if 0 */
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/libpng-config.in b/libraries/irrlicht-1.8/source/Irrlicht/libpng/libpng-config.in
new file mode 100644
index 0000000..199ad87
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/libpng-config.in
@@ -0,0 +1,127 @@
+#! /bin/sh
+# libpng-config
+# provides configuration info for libpng.
+# Copyright (C) 2002, 2004, 2006, 2007 Glenn Randers-Pehrson
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+# Modeled after libxml-config.
+version="@PNGLIB_VERSION@"
+prefix="@prefix@"
+exec_prefix="@exec_prefix@"
+libdir="@libdir@"
+includedir="@includedir@/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@"
+libs="-lpng@PNGLIB_MAJOR@@PNGLIB_MINOR@"
+all_libs="-lpng@PNGLIB_MAJOR@@PNGLIB_MINOR@ @LIBS@"
+I_opts="-I${includedir}"
+L_opts="-L${libdir}"
+R_opts=""
+cppflags=""
+ccopts=""
+ldopts=""
+usage()
+{
+    cat <<EOF
+Usage: $0 [OPTION] ...
+Known values for OPTION are:
+  --prefix        print libpng prefix
+  --libdir        print path to directory containing library
+  --libs          print library linking information
+  --ccopts        print compiler options
+  --cppflags      print pre-processor flags
+  --cflags        print preprocessor flags, I_opts, and compiler options
+  --I_opts        print "-I" include options
+  --L_opts        print linker "-L" flags for dynamic linking
+  --R_opts        print dynamic linker "-R" or "-rpath" flags
+  --ldopts        print linker options
+  --ldflags       print linker flags (ldopts, L_opts, R_opts, and libs)
+  --static        revise subsequent outputs for static linking
+  --help          print this help and exit
+  --version       print version information
+EOF
+    exit $1
+}
+if test $# -eq 0; then
+    usage 1
+fi
+while test $# -gt 0; do
+    case "$1" in
+    --prefix)
+        echo ${prefix}
+        ;;
+    --version)
+        echo ${version}
+        exit 0
+        ;;
+    --help)
+        usage 0
+        ;;
+    --ccopts)
+        echo ${ccopts}
+        ;;
+    --cppflags)
+        echo ${cppflags}
+        ;;
+    --cflags)
+        echo ${I_opts} ${cppflags} ${ccopts}
+        ;;
+    --libdir)
+        echo ${libdir}
+        ;;
+    --libs)
+        echo ${libs}
+        ;;
+    --I_opts)
+        echo ${I_opts}
+        ;;
+    --L_opts)
+        echo ${L_opts}
+        ;;
+    --R_opts)
+        echo ${R_opts}
+        ;;
+    --ldopts)
+        echo ${ldopts}
+        ;;
+    --ldflags)
+        echo ${ldopts} ${L_opts} ${R_opts} ${libs}
+        ;;
+    --static)
+        R_opts=""
+        libs=${all_libs}
+        ;;
+    *)
+        usage
+        exit 1
+        ;;
+    esac
+    shift
+done
+exit 0
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/libpng-manual.txt b/libraries/irrlicht-1.8/source/Irrlicht/libpng/libpng-manual.txt
new file mode 100644
index 0000000..d560264
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/libpng-manual.txt
@@ -0,0 +1,4628 @@
+libpng-manual.txt - A description on how to use and modify libpng
+ libpng version 1.5.9 - February 18, 2012
+ Updated and distributed by Glenn Randers-Pehrson
+ <glennrp at users.sourceforge.net>
+ Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ This document is released under the libpng license.
+ For conditions of distribution and use, see the disclaimer
+ and license in png.h
+ Based on:
+ libpng versions 0.97, January 1998, through 1.5.9 - February 18, 2012
+ Updated and distributed by Glenn Randers-Pehrson
+ Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ libpng 1.0 beta 6  version 0.96 May 28, 1997
+ Updated and distributed by Andreas Dilger
+ Copyright (c) 1996, 1997 Andreas Dilger
+ libpng 1.0 beta 2 - version 0.88  January 26, 1996
+ For conditions of distribution and use, see copyright
+ notice in png.h. Copyright (c) 1995, 1996 Guy Eric
+ Schalnat, Group 42, Inc.
+ Updated/rewritten per request in the libpng FAQ
+ Copyright (c) 1995, 1996 Frank J. T. Wojcik
+ December 18, 1995 & January 20, 1996
+I. Introduction
+This file describes how to use and modify the PNG reference library
+(known as libpng) for your own use.  There are five sections to this
+file: introduction, structures, reading, writing, and modification and
+configuration notes for various special platforms.  In addition to this
+file, example.c is a good starting point for using the library, as
+it is heavily commented and should include everything most people
+will need.  We assume that libpng is already installed; see the
+INSTALL file for instructions on how to install libpng.
+For examples of libpng usage, see the files "example.c", "pngtest.c",
+and the files in the "contrib" directory, all of which are included in
+the libpng distribution.
+Libpng was written as a companion to the PNG specification, as a way
+of reducing the amount of time and effort it takes to support the PNG
+file format in application programs.
+The PNG specification (second edition), November 2003, is available as
+a W3C Recommendation and as an ISO Standard (ISO/IEC 15948:2003 (E)) at
+<http://www.w3.org/TR/2003/REC-PNG-20031110/
+The W3C and ISO documents have identical technical content.
+The PNG-1.2 specification is available at
+<http://www.libpng.org/pub/png/documents/>.  It is technically equivalent
+to the PNG specification (second edition) but has some additional material.
+The PNG-1.0 specification is available
+as RFC 2083 <http://www.libpng.org/pub/png/documents/> and as a
+W3C Recommendation <http://www.w3.org/TR/REC.png.html>.
+Some additional chunks are described in the special-purpose public chunks
+documents at <http://www.libpng.org/pub/png/documents/>.
+Other information
+about PNG, and the latest version of libpng, can be found at the PNG home
+page, <http://www.libpng.org/pub/png/>.
+Most users will not have to modify the library significantly; advanced
+users may want to modify it more.  All attempts were made to make it as
+complete as possible, while keeping the code easy to understand.
+Currently, this library only supports C.  Support for other languages
+is being considered.
+Libpng has been designed to handle multiple sessions at one time,
+to be easily modifiable, to be portable to the vast majority of
+machines (ANSI, K&R, 16-, 32-, and 64-bit) available, and to be easy
+to use.  The ultimate goal of libpng is to promote the acceptance of
+the PNG file format in whatever way possible.  While there is still
+work to be done (see the TODO file), libpng should cover the
+majority of the needs of its users.
+Libpng uses zlib for its compression and decompression of PNG files.
+Further information about zlib, and the latest version of zlib, can
+be found at the zlib home page, <http://www.info-zip.org/pub/infozip/zlib/>.
+The zlib compression utility is a general purpose utility that is
+useful for more than PNG files, and can be used without libpng.
+See the documentation delivered with zlib for more details.
+You can usually find the source files for the zlib utility wherever you
+find the libpng source files.
+Libpng is thread safe, provided the threads are using different
+instances of the structures.  Each thread should have its own
+png_struct and png_info instances, and thus its own image.
+Libpng does not protect itself against two threads using the
+same instance of a structure.
+II. Structures
+There are two main structures that are important to libpng, png_struct
+and png_info.  Both are internal structures that are no longer exposed
+in the libpng interface (as of libpng 1.5.0).
+The png_info structure is designed to provide information about the
+PNG file.  At one time, the fields of png_info were intended to be
+directly accessible to the user.  However, this tended to cause problems
+with applications using dynamically loaded libraries, and as a result
+a set of interface functions for png_info (the png_get_*() and png_set_*()
+functions) was developed, and direct access to the png_info fields was
+deprecated..
+The png_struct structure is the object used by the library to decode a
+single image.  As of 1.5.0 this structure is also not exposed.
+Almost all libpng APIs require a pointer to a png_struct as the first argument.
+Many (in particular the png_set and png_get APIs) also require a pointer
+to png_info as the second argument.  Some application visible macros
+defined in png.h designed for basic data access (reading and writing
+integers in the PNG format) don't take a png_info pointer, but it's almost
+always safe to assume that a (png_struct*) has to be passed to call an API
+function.
+You can have more than one png_info structure associated with an image,
+as illustrated in pngtest.c, one for information valid prior to the
+IDAT chunks and another (called "end_info" below) for things after them.
+The png.h header file is an invaluable reference for programming with libpng.
+And while I'm on the topic, make sure you include the libpng header file:
+#include <png.h>
+and also (as of libpng-1.5.0) the zlib header file, if you need it:
+#include <zlib.h>
+Types
+The png.h header file defines a number of integral types used by the
+APIs.  Most of these are fairly obvious; for example types corresponding
+to integers of particular sizes and types for passing color values.
+One exception is how non-integral numbers are handled.  For application
+convenience most APIs that take such numbers have C (double) arguments,
+however internally PNG, and libpng, use 32 bit signed integers and encode
+the value by multiplying by 100,000.  As of libpng 1.5.0 a convenience
+macro PNG_FP_1 is defined in png.h along with a type (png_fixed_point)
+which is simply (png_int_32).
+All APIs that take (double) arguments also have a matching API that
+takes the corresponding fixed point integer arguments.  The fixed point
+API has the same name as the floating point one with "_fixed" appended.
+The actual range of values permitted in the APIs is frequently less than
+the full range of (png_fixed_point) (-21474 to +21474).  When APIs require
+a non-negative argument the type is recorded as png_uint_32 above.  Consult
+the header file and the text below for more information.
+Special care must be take with sCAL chunk handling because the chunk itself
+uses non-integral values encoded as strings containing decimal floating point
+numbers.  See the comments in the header file.
+Configuration
+The main header file function declarations are frequently protected by C
+preprocessing directives of the form:
+    #ifdef PNG_feature_SUPPORTED
+    declare-function
+    #endif
+    ...
+    #ifdef PNG_feature_SUPPORTED
+    use-function
+    #endif
+The library can be built without support for these APIs, although a
+standard build will have all implemented APIs.  Application programs
+should check the feature macros before using an API for maximum
+portability.  From libpng 1.5.0 the feature macros set during the build
+of libpng are recorded in the header file "pnglibconf.h" and this file
+is always included by png.h.
+If you don't need to change the library configuration from the default, skip to
+the next section ("Reading").
+Notice that some of the makefiles in the 'scripts' directory and (in 1.5.0) all
+of the build project files in the 'projects' directory simply copy
+scripts/pnglibconf.h.prebuilt to pnglibconf.h.  This means that these build
+systems do not permit easy auto-configuration of the library - they only
+support the default configuration.
+The easiest way to make minor changes to the libpng configuration when
+auto-configuration is supported is to add definitions to the command line
+using (typically) CPPFLAGS.  For example:
+CPPFLAGS=-DPNG_NO_FLOATING_ARITHMETIC
+will change the internal libpng math implementation for gamma correction and
+other arithmetic calculations to fixed point, avoiding the need for fast
+floating point support.  The result can be seen in the generated pnglibconf.h -
+make sure it contains the changed feature macro setting.
+If you need to make more extensive configuration changes - more than one or two
+feature macro settings - you can either add -DPNG_USER_CONFIG to the build
+command line and put a list of feature macro settings in pngusr.h or you can set
+DFA_XTRA (a makefile variable) to a file containing the same information in the
+form of 'option' settings.
+A. Changing pnglibconf.h
+A variety of methods exist to build libpng.  Not all of these support
+reconfiguration of pnglibconf.h.  To reconfigure pnglibconf.h it must either be
+rebuilt from scripts/pnglibconf.dfa using awk or it must be edited by hand.
+Hand editing is achieved by copying scripts/pnglibconf.h.prebuilt to
+pnglibconf.h and changing the lines defining the supported features, paying
+very close attention to the 'option' information in scripts/pnglibconf.dfa
+that describes those features and their requirements.  This is easy to get
+wrong.
+B. Configuration using DFA_XTRA
+Rebuilding from pnglibconf.dfa is easy if a functioning 'awk', or a later
+variant such as 'nawk' or 'gawk', is available.  The configure build will
+automatically find an appropriate awk and build pnglibconf.h.
+The scripts/pnglibconf.mak file contains a set of make rules for doing the
+same thing if configure is not used, and many of the makefiles in the scripts
+directory use this approach.
+When rebuilding simply write a new file containing changed options and set
+DFA_XTRA to the name of this file.  This causes the build to append the new file
+to the end of scripts/pnglibconf.dfa.  The pngusr.dfa file should contain lines
+of the following forms:
+everything = off
+This turns all optional features off.  Include it at the start of pngusr.dfa to
+make it easier to build a minimal configuration.  You will need to turn at least
+some features on afterward to enable either reading or writing code, or both.
+option feature on
+option feature off
+Enable or disable a single feature.  This will automatically enable other
+features required by a feature that is turned on or disable other features that
+require a feature which is turned off.  Conflicting settings will cause an error
+message to be emitted by awk.
+setting feature default value
+Changes the default value of setting 'feature' to 'value'.  There are a small
+number of settings listed at the top of pnglibconf.h, they are documented in the
+source code.  Most of these values have performance implications for the library
+but most of them have no visible effect on the API.  Some can also be overridden
+from the API.
+This method of building a customized pnglibconf.h is illustrated in
+contrib/pngminim/*.  See the "$(PNGCONF):" target in the makefile and
+pngusr.dfa in these directories.
+C. Configuration using PNG_USR_CONFIG
+If -DPNG_USR_CONFIG is added to the CFLAGS when pnglibconf.h is built the file
+pngusr.h will automatically be included before the options in
+scripts/pnglibconf.dfa are processed.  Your pngusr.h file should contain only
+macro definitions turning features on or off or setting settings.
+Apart from the global setting "everything = off" all the options listed above
+can be set using macros in pngusr.h:
+#define PNG_feature_SUPPORTED
+is equivalent to:
+option feature on
+#define PNG_NO_feature
+is equivalent to:
+option feature off
+#define PNG_feature value
+is equivalent to:
+setting feature default value
+Notice that in both cases, pngusr.dfa and pngusr.h, the contents of the
+pngusr file you supply override the contents of scripts/pnglibconf.dfa
+If confusing or incomprehensible behavior results it is possible to
+examine the intermediate file pnglibconf.dfn to find the full set of
+dependency information for each setting and option.  Simply locate the
+feature in the file and read the C comments that precede it.
+This method is also illustrated in the contrib/pngminim/* makefiles and
+pngusr.h.
+III. Reading
+We'll now walk you through the possible functions to call when reading
+in a PNG file sequentially, briefly explaining the syntax and purpose
+of each one.  See example.c and png.h for more detail.  While
+progressive reading is covered in the next section, you will still
+need some of the functions discussed in this section to read a PNG
+file.
+Setup
+You will want to do the I/O initialization(*) before you get into libpng,
+so if it doesn't work, you don't have much to undo.  Of course, you
+will also want to insure that you are, in fact, dealing with a PNG
+file.  Libpng provides a simple check to see if a file is a PNG file.
+To use it, pass in the first 1 to 8 bytes of the file to the function
+png_sig_cmp(), and it will return 0 (false) if the bytes match the
+corresponding bytes of the PNG signature, or nonzero (true) otherwise.
+Of course, the more bytes you pass in, the greater the accuracy of the
+prediction.
+If you are intending to keep the file pointer open for use in libpng,
+you must ensure you don't read more than 8 bytes from the beginning
+of the file, and you also have to make a call to png_set_sig_bytes_read()
+with the number of bytes you read from the beginning.  Libpng will
+then only check the bytes (if any) that your program didn't read.
+(*): If you are not using the standard I/O functions, you will need
+to replace them with custom functions.  See the discussion under
+Customizing libpng.
+    FILE *fp = fopen(file_name, "rb");
+    if (!fp)
+    {
+       return (ERROR);
+    }
+    fread(header, 1, number, fp);
+    is_png = !png_sig_cmp(header, 0, number);
+    if (!is_png)
+    {
+       return (NOT_PNG);
+    }
+Next, png_struct and png_info need to be allocated and initialized.  In
+order to ensure that the size of these structures is correct even with a
+dynamically linked libpng, there are functions to initialize and
+allocate the structures.  We also pass the library version, optional
+pointers to error handling functions, and a pointer to a data struct for
+use by the error functions, if necessary (the pointer and functions can
+be NULL if the default error handlers are to be used).  See the section
+on Changes to Libpng below regarding the old initialization functions.
+The structure allocation functions quietly return NULL if they fail to
+create the structure, so your application should check for that.
+    png_structp png_ptr = png_create_read_struct
+        (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
+        user_error_fn, user_warning_fn);
+    if (!png_ptr)
+       return (ERROR);
+    png_infop info_ptr = png_create_info_struct(png_ptr);
+    if (!info_ptr)
+    {
+       png_destroy_read_struct(&png_ptr,
+           (png_infopp)NULL, (png_infopp)NULL);
+       return (ERROR);
+    }
+If you want to use your own memory allocation routines,
+use a libpng that was built with PNG_USER_MEM_SUPPORTED defined, and use
+png_create_read_struct_2() instead of png_create_read_struct():
+    png_structp png_ptr = png_create_read_struct_2
+        (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
+        user_error_fn, user_warning_fn, (png_voidp)
+        user_mem_ptr, user_malloc_fn, user_free_fn);
+The error handling routines passed to png_create_read_struct()
+and the memory alloc/free routines passed to png_create_struct_2()
+are only necessary if you are not using the libpng supplied error
+handling and memory alloc/free functions.
+When libpng encounters an error, it expects to longjmp back
+to your routine.  Therefore, you will need to call setjmp and pass
+your png_jmpbuf(png_ptr).  If you read the file from different
+routines, you will need to update the longjmp buffer every time you enter
+a new routine that will call a png_*() function.
+See your documentation of setjmp/longjmp for your compiler for more
+information on setjmp/longjmp.  See the discussion on libpng error
+handling in the Customizing Libpng section below for more information
+on the libpng error handling.  If an error occurs, and libpng longjmp's
+back to your setjmp, you will want to call png_destroy_read_struct() to
+free any memory.
+    if (setjmp(png_jmpbuf(png_ptr)))
+    {
+       png_destroy_read_struct(&png_ptr, &info_ptr,
+           &end_info);
+       fclose(fp);
+       return (ERROR);
+    }
+Pass (png_infopp)NULL instead of &end_info if you didn't create
+an end_info structure.
+If you would rather avoid the complexity of setjmp/longjmp issues,
+you can compile libpng with PNG_NO_SETJMP, in which case
+errors will result in a call to PNG_ABORT() which defaults to abort().
+You can #define PNG_ABORT() to a function that does something
+more useful than abort(), as long as your function does not
+return.
+Now you need to set up the input code.  The default for libpng is to
+use the C function fread().  If you use this, you will need to pass a
+valid FILE * in the function png_init_io().  Be sure that the file is
+opened in binary mode.  If you wish to handle reading data in another
+way, you need not call the png_init_io() function, but you must then
+implement the libpng I/O methods discussed in the Customizing Libpng
+section below.
+    png_init_io(png_ptr, fp);
+If you had previously opened the file and read any of the signature from
+the beginning in order to see if this was a PNG file, you need to let
+libpng know that there are some bytes missing from the start of the file.
+    png_set_sig_bytes(png_ptr, number);
+You can change the zlib compression buffer size to be used while
+reading compressed data with
+    png_set_compression_buffer_size(png_ptr, buffer_size);
+where the default size is 8192 bytes.  Note that the buffer size
+is changed immediately and the buffer is reallocated immediately,
+instead of setting a flag to be acted upon later.
+If you want CRC errors to be handled in a different manner than
+the default, use
+    png_set_crc_action(png_ptr, crit_action, ancil_action);
+The values for png_set_crc_action() say how libpng is to handle CRC errors in
+ancillary and critical chunks, and whether to use the data contained
+therein.  Note that it is impossible to "discard" data in a critical
+chunk.
+Choices for (int) crit_action are
+   PNG_CRC_DEFAULT      0  error/quit
+   PNG_CRC_ERROR_QUIT   1  error/quit
+   PNG_CRC_WARN_USE     3  warn/use data
+   PNG_CRC_QUIET_USE    4  quiet/use data
+   PNG_CRC_NO_CHANGE    5  use the current value
+Choices for (int) ancil_action are
+   PNG_CRC_DEFAULT      0  error/quit
+   PNG_CRC_ERROR_QUIT   1  error/quit
+   PNG_CRC_WARN_DISCARD 2  warn/discard data
+   PNG_CRC_WARN_USE     3  warn/use data
+   PNG_CRC_QUIET_USE    4  quiet/use data
+   PNG_CRC_NO_CHANGE    5  use the current value
+Setting up callback code
+You can set up a callback function to handle any unknown chunks in the
+input stream. You must supply the function
+    read_chunk_callback(png_structp png_ptr,
+         png_unknown_chunkp chunk);
+    {
+       /* The unknown chunk structure contains your
+          chunk data, along with similar data for any other
+          unknown chunks: */
+           png_byte name[5];
+           png_byte *data;
+           png_size_t size;
+       /* Note that libpng has already taken care of
+          the CRC handling */
+       /* put your code here.  Search for your chunk in the
+          unknown chunk structure, process it, and return one
+          of the following: */
+       return (-n); /* chunk had an error */
+       return (0); /* did not recognize */
+       return (n); /* success */
+    }
+(You can give your function another name that you like instead of
+"read_chunk_callback")
+To inform libpng about your function, use
+    png_set_read_user_chunk_fn(png_ptr, user_chunk_ptr,
+        read_chunk_callback);
+This names not only the callback function, but also a user pointer that
+you can retrieve with
+    png_get_user_chunk_ptr(png_ptr);
+If you call the png_set_read_user_chunk_fn() function, then all unknown
+chunks will be saved when read, in case your callback function will need
+one or more of them.  This behavior can be changed with the
+png_set_keep_unknown_chunks() function, described below.
+At this point, you can set up a callback function that will be
+called after each row has been read, which you can use to control
+a progress meter or the like.  It's demonstrated in pngtest.c.
+You must supply a function
+    void read_row_callback(png_structp png_ptr,
+       png_uint_32 row, int pass);
+    {
+      /* put your code here */
+    }
+(You can give it another name that you like instead of "read_row_callback")
+To inform libpng about your function, use
+    png_set_read_status_fn(png_ptr, read_row_callback);
+When this function is called the row has already been completely processed and
+the 'row' and 'pass' refer to the next row to be handled.  For the
+non-interlaced case the row that was just handled is simply one less than the
+passed in row number, and pass will always be 0.  For the interlaced case the
+same applies unless the row value is 0, in which case the row just handled was
+the last one from one of the preceding passes.  Because interlacing may skip a
+pass you cannot be sure that the preceding pass is just 'pass-1', if you really
+need to know what the last pass is record (row,pass) from the callback and use
+the last recorded value each time.
+As with the user transform you can find the output row using the
+PNG_ROW_FROM_PASS_ROW macro.
+Unknown-chunk handling
+Now you get to set the way the library processes unknown chunks in the
+input PNG stream. Both known and unknown chunks will be read.  Normal
+behavior is that known chunks will be parsed into information in
+various info_ptr members while unknown chunks will be discarded. This
+behavior can be wasteful if your application will never use some known
+chunk types. To change this, you can call:
+    png_set_keep_unknown_chunks(png_ptr, keep,
+        chunk_list, num_chunks);
+    keep       - 0: default unknown chunk handling
+                 1: ignore; do not keep
+                 2: keep only if safe-to-copy
+                 3: keep even if unsafe-to-copy
+               You can use these definitions:
+                 PNG_HANDLE_CHUNK_AS_DEFAULT   0
+                 PNG_HANDLE_CHUNK_NEVER        1
+                 PNG_HANDLE_CHUNK_IF_SAFE      2
+                 PNG_HANDLE_CHUNK_ALWAYS       3
+    chunk_list - list of chunks affected (a byte string,
+                 five bytes per chunk, NULL or '\0' if
+                 num_chunks is 0)
+    num_chunks - number of chunks affected; if 0, all
+                 unknown chunks are affected.  If nonzero,
+                 only the chunks in the list are affected
+Unknown chunks declared in this way will be saved as raw data onto a
+list of png_unknown_chunk structures.  If a chunk that is normally
+known to libpng is named in the list, it will be handled as unknown,
+according to the "keep" directive.  If a chunk is named in successive
+instances of png_set_keep_unknown_chunks(), the final instance will
+take precedence.  The IHDR and IEND chunks should not be named in
+chunk_list; if they are, libpng will process them normally anyway.
+If you know that your application will never make use of some particular
+chunks, use PNG_HANDLE_CHUNK_NEVER (or 1) as demonstrated below.
+Here is an example of the usage of png_set_keep_unknown_chunks(),
+where the private "vpAg" chunk will later be processed by a user chunk
+callback function:
+    png_byte vpAg[5]={118, 112,  65, 103, (png_byte) '\0'};
+    #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
+      png_byte unused_chunks[]=
+      {
+        104,  73,  83,  84, (png_byte) '\0',   /* hIST */
+        105,  84,  88, 116, (png_byte) '\0',   /* iTXt */
+        112,  67,  65,  76, (png_byte) '\0',   /* pCAL */
+        115,  67,  65,  76, (png_byte) '\0',   /* sCAL */
+        115,  80,  76,  84, (png_byte) '\0',   /* sPLT */
+        116,  73,  77,  69, (png_byte) '\0',   /* tIME */
+      };
+    #endif
+    ...
+    #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
+      /* ignore all unknown chunks: */
+      png_set_keep_unknown_chunks(read_ptr, 1, NULL, 0);
+      /* except for vpAg: */
+      png_set_keep_unknown_chunks(read_ptr, 2, vpAg, 1);
+      /* also ignore unused known chunks: */
+      png_set_keep_unknown_chunks(read_ptr, 1, unused_chunks,
+         (int)sizeof(unused_chunks)/5);
+    #endif
+User limits
+The PNG specification allows the width and height of an image to be as
+large as 2^31-1 (0x7fffffff), or about 2.147 billion rows and columns.
+Since very few applications really need to process such large images,
+we have imposed an arbitrary 1-million limit on rows and columns.
+Larger images will be rejected immediately with a png_error() call. If
+you wish to change this limit, you can use
+   png_set_user_limits(png_ptr, width_max, height_max);
+to set your own limits, or use width_max = height_max = 0x7fffffffL
+to allow all valid dimensions (libpng may reject some very large images
+anyway because of potential buffer overflow conditions).
+You should put this statement after you create the PNG structure and
+before calling png_read_info(), png_read_png(), or png_process_data().
+When writing a PNG datastream, put this statement before calling
+png_write_info() or png_write_png().
+If you need to retrieve the limits that are being applied, use
+   width_max = png_get_user_width_max(png_ptr);
+   height_max = png_get_user_height_max(png_ptr);
+The PNG specification sets no limit on the number of ancillary chunks
+allowed in a PNG datastream.  You can impose a limit on the total number
+of sPLT, tEXt, iTXt, zTXt, and unknown chunks that will be stored, with
+   png_set_chunk_cache_max(png_ptr, user_chunk_cache_max);
+where 0x7fffffffL means unlimited.  You can retrieve this limit with
+   chunk_cache_max = png_get_chunk_cache_max(png_ptr);
+This limit also applies to the number of buffers that can be allocated
+by png_decompress_chunk() while decompressing iTXt, zTXt, and iCCP chunks.
+You can also set a limit on the amount of memory that a compressed chunk
+other than IDAT can occupy, with
+   png_set_chunk_malloc_max(png_ptr, user_chunk_malloc_max);
+and you can retrieve the limit with
+   chunk_malloc_max = png_get_chunk_malloc_max(png_ptr);
+Any chunks that would cause either of these limits to be exceeded will
+be ignored.
+Information about your system
+If you intend to display the PNG or to incorporate it in other image data you
+need to tell libpng information about your display or drawing surface so that
+libpng can convert the values in the image to match the display.
+From libpng-1.5.4 this information can be set before reading the PNG file
+header.  In earlier versions png_set_gamma() existed but behaved incorrectly if
+called before the PNG file header had been read and png_set_alpha_mode() did not
+exist.
+If you need to support versions prior to libpng-1.5.4 test the version number
+as illustrated below using "PNG_LIBPNG_VER >= 10504" and follow the procedures
+described in the appropriate manual page.
+You give libpng the encoding expected by your system expressed as a 'gamma'
+value.  You can also specify a default encoding for the PNG file in
+case the required information is missing from the file.  By default libpng
+assumes that the PNG data matches your system, to keep this default call:
+   png_set_gamma(png_ptr, screen_gamma, 1/screen_gamma/*file gamma*/);
+or you can use the fixed point equivalent:
+   png_set_gamma_fixed(png_ptr, PNG_FP_1*screen_gamma, PNG_FP_1/screen_gamma);
+If you don't know the gamma for your system it is probably 2.2 - a good
+approximation to the IEC standard for display systems (sRGB).  If images are
+too contrasty or washed out you got the value wrong - check your system
+documentation!
+Many systems permit the system gamma to be changed via a lookup table in the
+display driver, a few systems, including older Macs, change the response by
+default.  As of 1.5.4 three special values are available to handle common
+situations:
+   PNG_DEFAULT_sRGB: Indicates that the system conforms to the IEC 61966-2-1
+                     standard.  This matches almost all systems.
+   PNG_GAMMA_MAC_18: Indicates that the system is an older (pre Mac OS 10.6)
+                     Apple Macintosh system with the default settings.
+   PNG_GAMMA_LINEAR: Just the fixed point value for 1.0 - indicates that the
+                     system expects data with no gamma encoding.
+You would use the linear (unencoded) value if you need to process the pixel
+values further because this avoids the need to decode and reencode each
+component value whenever arithmetic is performed.  A lot of graphics software
+uses linear values for this reason, often with higher precision component values
+to preserve overall accuracy.
+The second thing you may need to tell libpng about is how your system handles
+alpha channel information.  Some, but not all, PNG files contain an alpha
+channel.  To display these files correctly you need to compose the data onto a
+suitable background, as described in the PNG specification.
+Libpng only supports composing onto a single color (using png_set_background;
+see below).  Otherwise you must do the composition yourself and, in this case,
+you may need to call png_set_alpha_mode:
+#if PNG_LIBPNG_VER >= 10504
+   png_set_alpha_mode(png_ptr, mode, screen_gamma);
+#else
+   png_set_gamma(png_ptr, screen_gamma, 1.0/screen_gamma);
+#endif
+The screen_gamma value is the same as the argument to png_set_gamma; however,
+how it affects the output depends on the mode.  png_set_alpha_mode() sets the
+file gamma default to 1/screen_gamma, so normally you don't need to call
+png_set_gamma.  If you need different defaults call png_set_gamma() before
+png_set_alpha_mode() - if you call it after it will override the settings made
+by png_set_alpha_mode().
+The mode is as follows:
+    PNG_ALPHA_PNG: The data is encoded according to the PNG specification.  Red,
+green and blue, or gray, components are gamma encoded color
+values and are not premultiplied by the alpha value.  The
+alpha value is a linear measure of the contribution of the
+pixel to the corresponding final output pixel.
+You should normally use this format if you intend to perform
+color correction on the color values; most, maybe all, color
+correction software has no handling for the alpha channel and,
+anyway, the math to handle pre-multiplied component values is
+unnecessarily complex.
+Before you do any arithmetic on the component values you need
+to remove the gamma encoding and multiply out the alpha
+channel.  See the PNG specification for more detail.  It is
+important to note that when an image with an alpha channel is
+scaled, linear encoded, pre-multiplied component values must
+be used!
+The remaining modes assume you don't need to do any further color correction or
+that if you do, your color correction software knows all about alpha (it
+probably doesn't!)
+    PNG_ALPHA_STANDARD:  The data libpng produces
+is encoded in the standard way
+assumed by most correctly written graphics software.
+The gamma encoding will be removed by libpng and the
+linear component values will be pre-multiplied by the
+alpha channel.
+With this format the final image must be re-encoded to
+match the display gamma before the image is displayed.
+If your system doesn't do that, yet still seems to
+perform arithmetic on the pixels without decoding them,
+it is broken - check out the modes below.
+With PNG_ALPHA_STANDARD libpng always produces linear
+component values, whatever screen_gamma you supply.  The
+screen_gamma value is, however, used as a default for
+the file gamma if the PNG file has no gamma information.
+If you call png_set_gamma() after png_set_alpha_mode() you
+will override the linear encoding.  Instead the
+pre-multiplied pixel values will be gamma encoded but
+the alpha channel will still be linear.  This may
+actually match the requirements of some broken software,
+but it is unlikely.
+While linear 8-bit data is often used it has
+insufficient precision for any image with a reasonable
+dynamic range.  To avoid problems, and if your software
+supports it, use png_set_expand_16() to force all
+components to 16 bits.
+    PNG_ALPHA_OPTIMIZED: This mode is the same
+as PNG_ALPHA_STANDARD except that
+completely opaque pixels are gamma encoded according to
+the screen_gamma value.  Pixels with alpha less than 1.0
+will still have linear components.
+Use this format if you have control over your
+compositing software and do don't do other arithmetic
+(such as scaling) on the data you get from libpng.  Your
+compositing software can simply copy opaque pixels to
+the output but still has linear values for the
+non-opaque pixels.
+In normal compositing, where the alpha channel encodes
+partial pixel coverage (as opposed to broad area
+translucency), the inaccuracies of the 8-bit
+representation of non-opaque pixels are irrelevant.
+You can also try this format if your software is broken;
+it might look better.
+    PNG_ALPHA_BROKEN: This is PNG_ALPHA_STANDARD;
+however, all component values,
+including the alpha channel are gamma encoded.  This is
+an appropriate format to try if your software, or more
+likely hardware, is totally broken, i.e., if it performs
+linear arithmetic directly on gamma encoded values.
+In most cases of broken software or hardware the bug in the final display
+manifests as a subtle halo around composited parts of the image.  You may not
+even perceive this as a halo; the composited part of the image may simply appear
+separate from the background, as though it had been cut out of paper and pasted
+on afterward.
+If you don't have to deal with bugs in software or hardware, or if you can fix
+them, there are three recommended ways of using png_set_alpha_mode():
+   png_set_alpha_mode(png_ptr, PNG_ALPHA_PNG,
+       screen_gamma);
+You can do color correction on the result (libpng does not currently
+support color correction internally).  When you handle the alpha channel
+you need to undo the gamma encoding and multiply out the alpha.
+   png_set_alpha_mode(png_ptr, PNG_ALPHA_STANDARD,
+       screen_gamma);
+   png_set_expand_16(png_ptr);
+If you are using the high level interface, don't call png_set_expand_16();
+instead pass PNG_TRANSFORM_EXPAND_16 to the interface.
+With this mode you can't do color correction, but you can do arithmetic,
+including composition and scaling, on the data without further processing.
+   png_set_alpha_mode(png_ptr, PNG_ALPHA_OPTIMIZED,
+       screen_gamma);
+You can avoid the expansion to 16-bit components with this mode, but you
+lose the ability to scale the image or perform other linear arithmetic.
+All you can do is compose the result onto a matching output.  Since this
+mode is libpng-specific you also need to write your own composition
+software.
+If you don't need, or can't handle, the alpha channel you can call
+png_set_background() to remove it by compositing against a fixed color.  Don't
+call png_set_strip_alpha() to do this - it will leave spurious pixel values in
+transparent parts of this image.
+   png_set_background(png_ptr, &background_color,
+       PNG_BACKGROUND_GAMMA_SCREEN, 0, 1);
+The background_color is an RGB or grayscale value according to the data format
+libpng will produce for you.  Because you don't yet know the format of the PNG
+file, if you call png_set_background at this point you must arrange for the
+format produced by libpng to always have 8-bit or 16-bit components and then
+store the color as an 8-bit or 16-bit color as appropriate.  The color contains
+separate gray and RGB component values, so you can let libpng produce gray or
+RGB output according to the input format, but low bit depth grayscale images
+must always be converted to at least 8-bit format.  (Even though low bit depth
+grayscale images can't have an alpha channel they can have a transparent
+color!)
+You set the transforms you need later, either as flags to the high level
+interface or libpng API calls for the low level interface.  For reference the
+settings and API calls required are:
+8-bit values:
+   PNG_TRANSFORM_SCALE_16 | PNG_EXPAND
+   png_set_expand(png_ptr); png_set_scale_16(png_ptr);
+   If you must get exactly the same inaccurate results
+   produced by default in versions prior to libpng-1.5.4,
+   use PNG_TRANSFORM_STRIP_16 and png_set_strip_16(png_ptr)
+   instead.
+16-bit values:
+   PNG_TRANSFORM_EXPAND_16
+   png_set_expand_16(png_ptr);
+In either case palette image data will be expanded to RGB.  If you just want
+color data you can add PNG_TRANSFORM_GRAY_TO_RGB or png_set_gray_to_rgb(png_ptr)
+to the list.
+Calling png_set_background before the PNG file header is read will not work
+prior to libpng-1.5.4.  Because the failure may result in unexpected warnings or
+errors it is therefore much safer to call png_set_background after the head has
+been read.  Unfortunately this means that prior to libpng-1.5.4 it cannot be
+used with the high level interface.
+The high-level read interface
+At this point there are two ways to proceed; through the high-level
+read interface, or through a sequence of low-level read operations.
+You can use the high-level interface if (a) you are willing to read
+the entire image into memory, and (b) the input transformations
+you want to do are limited to the following set:
+    PNG_TRANSFORM_IDENTITY      No transformation
+    PNG_TRANSFORM_SCALE_16      Strip 16-bit samples to
+                                8-bit accurately
+    PNG_TRANSFORM_STRIP_16      Chop 16-bit samples to
+                                8-bit less accurately
+    PNG_TRANSFORM_STRIP_ALPHA   Discard the alpha channel
+    PNG_TRANSFORM_PACKING       Expand 1, 2 and 4-bit
+                                samples to bytes
+    PNG_TRANSFORM_PACKSWAP      Change order of packed
+                                pixels to LSB first
+    PNG_TRANSFORM_EXPAND        Perform set_expand()
+    PNG_TRANSFORM_INVERT_MONO   Invert monochrome images
+    PNG_TRANSFORM_SHIFT         Normalize pixels to the
+                                sBIT depth
+    PNG_TRANSFORM_BGR           Flip RGB to BGR, RGBA
+                                to BGRA
+    PNG_TRANSFORM_SWAP_ALPHA    Flip RGBA to ARGB or GA
+                                to AG
+    PNG_TRANSFORM_INVERT_ALPHA  Change alpha from opacity
+                                to transparency
+    PNG_TRANSFORM_SWAP_ENDIAN   Byte-swap 16-bit samples
+    PNG_TRANSFORM_GRAY_TO_RGB   Expand grayscale samples
+                                to RGB (or GA to RGBA)
+    PNG_TRANSFORM_EXPAND_16     Expand samples to 16 bits
+(This excludes setting a background color, doing gamma transformation,
+quantizing, and setting filler.)  If this is the case, simply do this:
+    png_read_png(png_ptr, info_ptr, png_transforms, NULL)
+where png_transforms is an integer containing the bitwise OR of some
+set of transformation flags.  This call is equivalent to png_read_info(),
+followed the set of transformations indicated by the transform mask,
+then png_read_image(), and finally png_read_end().
+(The final parameter of this call is not yet used.  Someday it might point
+to transformation parameters required by some future input transform.)
+You must use png_transforms and not call any png_set_transform() functions
+when you use png_read_png().
+After you have called png_read_png(), you can retrieve the image data
+with
+   row_pointers = png_get_rows(png_ptr, info_ptr);
+where row_pointers is an array of pointers to the pixel data for each row:
+   png_bytep row_pointers[height];
+If you know your image size and pixel size ahead of time, you can allocate
+row_pointers prior to calling png_read_png() with
+   if (height > PNG_UINT_32_MAX/png_sizeof(png_byte))
+      png_error (png_ptr,
+          "Image is too tall to process in memory");
+   if (width > PNG_UINT_32_MAX/pixel_size)
+      png_error (png_ptr,
+          "Image is too wide to process in memory");
+   row_pointers = png_malloc(png_ptr,
+       height*png_sizeof(png_bytep));
+   for (int i=0; i<height, i++)
+      row_pointers[i]=NULL;  /* security precaution */
+   for (int i=0; i<height, i++)
+      row_pointers[i]=png_malloc(png_ptr,
+          width*pixel_size);
+   png_set_rows(png_ptr, info_ptr, &row_pointers);
+Alternatively you could allocate your image in one big block and define
+row_pointers[i] to point into the proper places in your block.
+If you use png_set_rows(), the application is responsible for freeing
+row_pointers (and row_pointers[i], if they were separately allocated).
+If you don't allocate row_pointers ahead of time, png_read_png() will
+do it, and it'll be free'ed by libpng when you call png_destroy_*().
+The low-level read interface
+If you are going the low-level route, you are now ready to read all
+the file information up to the actual image data.  You do this with a
+call to png_read_info().
+    png_read_info(png_ptr, info_ptr);
+This will process all chunks up to but not including the image data.
+This also copies some of the data from the PNG file into the decode structure
+for use in later transformations.  Important information copied in is:
+1) The PNG file gamma from the gAMA chunk.  This overwrites the default value
+provided by an earlier call to png_set_gamma or png_set_alpha_mode.
+2) Prior to libpng-1.5.4 the background color from a bKGd chunk.  This
+damages the information provided by an earlier call to png_set_background
+resulting in unexpected behavior.  Libpng-1.5.4 no longer does this.
+3) The number of significant bits in each component value.  Libpng uses this to
+optimize gamma handling by reducing the internal lookup table sizes.
+4) The transparent color information from a tRNS chunk.  This can be modified by
+a later call to png_set_tRNS.
+Querying the info structure
+Functions are used to get the information from the info_ptr once it
+has been read.  Note that these fields may not be completely filled
+in until png_read_end() has read the chunk data following the image.
+    png_get_IHDR(png_ptr, info_ptr, &width, &height,
+       &bit_depth, &color_type, &interlace_type,
+       &compression_type, &filter_method);
+    width          - holds the width of the image
+                     in pixels (up to 2^31).
+    height         - holds the height of the image
+                     in pixels (up to 2^31).
+    bit_depth      - holds the bit depth of one of the
+                     image channels.  (valid values are
+                     1, 2, 4, 8, 16 and depend also on
+                     the color_type.  See also
+                     significant bits (sBIT) below).
+    color_type     - describes which color/alpha channels
+                         are present.
+                     PNG_COLOR_TYPE_GRAY
+                        (bit depths 1, 2, 4, 8, 16)
+                     PNG_COLOR_TYPE_GRAY_ALPHA
+                        (bit depths 8, 16)
+                     PNG_COLOR_TYPE_PALETTE
+                        (bit depths 1, 2, 4, 8)
+                     PNG_COLOR_TYPE_RGB
+                        (bit_depths 8, 16)
+                     PNG_COLOR_TYPE_RGB_ALPHA
+                        (bit_depths 8, 16)
+                     PNG_COLOR_MASK_PALETTE
+                     PNG_COLOR_MASK_COLOR
+                     PNG_COLOR_MASK_ALPHA
+    interlace_type - (PNG_INTERLACE_NONE or
+                     PNG_INTERLACE_ADAM7)
+    compression_type - (must be PNG_COMPRESSION_TYPE_BASE
+                     for PNG 1.0)
+    filter_method  - (must be PNG_FILTER_TYPE_BASE
+                     for PNG 1.0, and can also be
+                     PNG_INTRAPIXEL_DIFFERENCING if
+                     the PNG datastream is embedded in
+                     a MNG-1.0 datastream)
+    Any or all of interlace_type, compression_type, or
+    filter_method can be NULL if you are
+    not interested in their values.
+    Note that png_get_IHDR() returns 32-bit data into
+    the application's width and height variables.
+    This is an unsafe situation if these are 16-bit
+    variables.  In such situations, the
+    png_get_image_width() and png_get_image_height()
+    functions described below are safer.
+    width            = png_get_image_width(png_ptr,
+                         info_ptr);
+    height           = png_get_image_height(png_ptr,
+                         info_ptr);
+    bit_depth        = png_get_bit_depth(png_ptr,
+                         info_ptr);
+    color_type       = png_get_color_type(png_ptr,
+                         info_ptr);
+    interlace_type   = png_get_interlace_type(png_ptr,
+                         info_ptr);
+    compression_type = png_get_compression_type(png_ptr,
+                         info_ptr);
+    filter_method    = png_get_filter_type(png_ptr,
+                         info_ptr);
+    channels = png_get_channels(png_ptr, info_ptr);
+    channels       - number of channels of info for the
+                     color type (valid values are 1 (GRAY,
+                     PALETTE), 2 (GRAY_ALPHA), 3 (RGB),
+                     4 (RGB_ALPHA or RGB + filler byte))
+    rowbytes = png_get_rowbytes(png_ptr, info_ptr);
+    rowbytes       - number of bytes needed to hold a row
+    signature = png_get_signature(png_ptr, info_ptr);
+    signature      - holds the signature read from the
+                     file (if any).  The data is kept in
+                     the same offset it would be if the
+                     whole signature were read (i.e. if an
+                     application had already read in 4
+                     bytes of signature before starting
+                     libpng, the remaining 4 bytes would
+                     be in signature[4] through signature[7]
+                     (see png_set_sig_bytes())).
+These are also important, but their validity depends on whether the chunk
+has been read.  The png_get_valid(png_ptr, info_ptr, PNG_INFO_<chunk>) and
+png_get_<chunk>(png_ptr, info_ptr, ...) functions return non-zero if the
+data has been read, or zero if it is missing.  The parameters to the
+png_get_<chunk> are set directly if they are simple data types, or a
+pointer into the info_ptr is returned for any complex types.
+    png_get_PLTE(png_ptr, info_ptr, &palette,
+                     &num_palette);
+    palette        - the palette for the file
+                     (array of png_color)
+    num_palette    - number of entries in the palette
+    png_get_gAMA(png_ptr, info_ptr, &file_gamma);
+    png_get_gAMA_fixed(png_ptr, info_ptr, &int_file_gamma);
+    file_gamma     - the gamma at which the file is
+                     written (PNG_INFO_gAMA)
+    int_file_gamma - 100,000 times the gamma at which the
+                     file is written
+    png_get_cHRM(png_ptr, info_ptr,  &white_x, &white_y, &red_x, &red_y,
+                     &green_x, &green_y, &blue_x, &blue_y)
+    png_get_cHRM_XYZ(png_ptr, info_ptr, &red_X, &red_Y, &red_Z, &green_X,
+                     &green_Y, &green_Z, &blue_X, &blue_Y, &blue_Z)
+    png_get_cHRM_fixed(png_ptr, info_ptr, &int_white_x, &int_white_y,
+                     &int_red_x, &int_red_y, &int_green_x, &int_green_y,
+                     &int_blue_x, &int_blue_y)
+    png_get_cHRM_XYZ_fixed(png_ptr, info_ptr, &int_red_X, &int_red_Y,
+                     &int_red_Z, &int_green_X, &int_green_Y, &int_green_Z,
+                     &int_blue_X, &int_blue_Y, &int_blue_Z)
+    {white,red,green,blue}_{x,y}
+                     A color space encoding specified using the chromaticities
+                     of the end points and the white point. (PNG_INFO_cHRM)
+    {red,green,blue}_{X,Y,Z}
+                     A color space encoding specified using the encoding end
+                     points - the CIE tristimulus specification of the intended
+                     color of the red, green and blue channels in the PNG RGB
+                     data.  The white point is simply the sum of the three end
+                     points. (PNG_INFO_cHRM)
+    png_get_sRGB(png_ptr, info_ptr, &srgb_intent);
+    file_srgb_intent - the rendering intent (PNG_INFO_sRGB)
+                     The presence of the sRGB chunk
+                     means that the pixel data is in the
+                     sRGB color space.  This chunk also
+                     implies specific values of gAMA and
+                     cHRM.
+    png_get_iCCP(png_ptr, info_ptr, &name,
+       &compression_type, &profile, &proflen);
+    name             - The profile name.
+    compression_type - The compression type; always
+                       PNG_COMPRESSION_TYPE_BASE for PNG 1.0.
+                       You may give NULL to this argument to
+                       ignore it.
+    profile          - International Color Consortium color
+                       profile data. May contain NULs.
+    proflen          - length of profile data in bytes.
+    png_get_sBIT(png_ptr, info_ptr, &sig_bit);
+    sig_bit        - the number of significant bits for
+                     (PNG_INFO_sBIT) each of the gray,
+                     red, green, and blue channels,
+                     whichever are appropriate for the
+                     given color type (png_color_16)
+    png_get_tRNS(png_ptr, info_ptr, &trans_alpha,
+                     &num_trans, &trans_color);
+    trans_alpha    - array of alpha (transparency)
+                     entries for palette (PNG_INFO_tRNS)
+    num_trans      - number of transparent entries
+                     (PNG_INFO_tRNS)
+    trans_color    - graylevel or color sample values of
+                     the single transparent color for
+                     non-paletted images (PNG_INFO_tRNS)
+    png_get_hIST(png_ptr, info_ptr, &hist);
+                     (PNG_INFO_hIST)
+    hist           - histogram of palette (array of
+                     png_uint_16)
+    png_get_tIME(png_ptr, info_ptr, &mod_time);
+    mod_time       - time image was last modified
+                    (PNG_VALID_tIME)
+    png_get_bKGD(png_ptr, info_ptr, &background);
+    background     - background color (of type
+                     png_color_16p) (PNG_VALID_bKGD)
+                     valid 16-bit red, green and blue
+                     values, regardless of color_type
+    num_comments   = png_get_text(png_ptr, info_ptr,
+                     &text_ptr, &num_text);
+    num_comments   - number of comments
+    text_ptr       - array of png_text holding image
+                     comments
+    text_ptr[i].compression - type of compression used
+                 on "text" PNG_TEXT_COMPRESSION_NONE
+                           PNG_TEXT_COMPRESSION_zTXt
+                           PNG_ITXT_COMPRESSION_NONE
+                           PNG_ITXT_COMPRESSION_zTXt
+    text_ptr[i].key   - keyword for comment.  Must contain
+                         1-79 characters.
+    text_ptr[i].text  - text comments for current
+                         keyword.  Can be empty.
+    text_ptr[i].text_length - length of text string,
+                 after decompression, 0 for iTXt
+    text_ptr[i].itxt_length - length of itxt string,
+                 after decompression, 0 for tEXt/zTXt
+    text_ptr[i].lang  - language of comment (empty
+                         string for unknown).
+    text_ptr[i].lang_key  - keyword in UTF-8
+                         (empty string for unknown).
+    Note that the itxt_length, lang, and lang_key
+    members of the text_ptr structure only exist when the
+    library is built with iTXt chunk support.  Prior to
+    libpng-1.4.0 the library was built by default without
+    iTXt support. Also note that when iTXt is supported,
+    they contain NULL pointers when the "compression"
+    field contains PNG_TEXT_COMPRESSION_NONE or
+    PNG_TEXT_COMPRESSION_zTXt.
+    num_text       - number of comments (same as
+                     num_comments; you can put NULL here
+                     to avoid the duplication)
+    Note while png_set_text() will accept text, language,
+    and translated keywords that can be NULL pointers, the
+    structure returned by png_get_text will always contain
+    regular zero-terminated C strings.  They might be
+    empty strings but they will never be NULL pointers.
+    num_spalettes = png_get_sPLT(png_ptr, info_ptr,
+       &palette_ptr);
+    num_spalettes  - number of sPLT chunks read.
+    palette_ptr    - array of palette structures holding
+                     contents of one or more sPLT chunks
+                     read.
+    png_get_oFFs(png_ptr, info_ptr, &offset_x, &offset_y,
+       &unit_type);
+    offset_x       - positive offset from the left edge
+                     of the screen (can be negative)
+    offset_y       - positive offset from the top edge
+                     of the screen (can be negative)
+    unit_type      - PNG_OFFSET_PIXEL, PNG_OFFSET_MICROMETER
+    png_get_pHYs(png_ptr, info_ptr, &res_x, &res_y,
+       &unit_type);
+    res_x          - pixels/unit physical resolution in
+                     x direction
+    res_y          - pixels/unit physical resolution in
+                     x direction
+    unit_type      - PNG_RESOLUTION_UNKNOWN,
+                     PNG_RESOLUTION_METER
+    png_get_sCAL(png_ptr, info_ptr, &unit, &width,
+       &height)
+    unit        - physical scale units (an integer)
+    width       - width of a pixel in physical scale units
+    height      - height of a pixel in physical scale units
+                 (width and height are doubles)
+    png_get_sCAL_s(png_ptr, info_ptr, &unit, &width,
+       &height)
+    unit        - physical scale units (an integer)
+    width       - width of a pixel in physical scale units
+                  (expressed as a string)
+    height      - height of a pixel in physical scale units
+                 (width and height are strings like "2.54")
+    num_unknown_chunks = png_get_unknown_chunks(png_ptr,
+       info_ptr, &unknowns)
+    unknowns          - array of png_unknown_chunk
+                        structures holding unknown chunks
+    unknowns[i].name  - name of unknown chunk
+    unknowns[i].data  - data of unknown chunk
+    unknowns[i].size  - size of unknown chunk's data
+    unknowns[i].location - position of chunk in file
+    The value of "i" corresponds to the order in which the
+    chunks were read from the PNG file or inserted with the
+    png_set_unknown_chunks() function.
+    The value of "location" is a bitwise "or" of
+         PNG_HAVE_IHDR  (0x01)
+         PNG_HAVE_PLTE  (0x02)
+         PNG_AFTER_IDAT (0x08)
+The data from the pHYs chunk can be retrieved in several convenient
+forms:
+    res_x = png_get_x_pixels_per_meter(png_ptr,
+       info_ptr)
+    res_y = png_get_y_pixels_per_meter(png_ptr,
+       info_ptr)
+    res_x_and_y = png_get_pixels_per_meter(png_ptr,
+       info_ptr)
+    res_x = png_get_x_pixels_per_inch(png_ptr,
+       info_ptr)
+    res_y = png_get_y_pixels_per_inch(png_ptr,
+       info_ptr)
+    res_x_and_y = png_get_pixels_per_inch(png_ptr,
+       info_ptr)
+    aspect_ratio = png_get_pixel_aspect_ratio(png_ptr,
+       info_ptr)
+    Each of these returns 0 [signifying "unknown"] if
+       the data is not present or if res_x is 0;
+       res_x_and_y is 0 if res_x != res_y
+    Note that because of the way the resolutions are
+       stored internally, the inch conversions won't
+       come out to exactly even number.  For example,
+       72 dpi is stored as 0.28346 pixels/meter, and
+       when this is retrieved it is 71.9988 dpi, so
+       be sure to round the returned value appropriately
+       if you want to display a reasonable-looking result.
+The data from the oFFs chunk can be retrieved in several convenient
+forms:
+    x_offset = png_get_x_offset_microns(png_ptr, info_ptr);
+    y_offset = png_get_y_offset_microns(png_ptr, info_ptr);
+    x_offset = png_get_x_offset_inches(png_ptr, info_ptr);
+    y_offset = png_get_y_offset_inches(png_ptr, info_ptr);
+    Each of these returns 0 [signifying "unknown" if both
+       x and y are 0] if the data is not present or if the
+       chunk is present but the unit is the pixel.  The
+       remark about inexact inch conversions applies here
+       as well, because a value in inches can't always be
+       converted to microns and back without some loss
+       of precision.
+For more information, see the
+PNG specification for chunk contents.  Be careful with trusting
+rowbytes, as some of the transformations could increase the space
+needed to hold a row (expand, filler, gray_to_rgb, etc.).
+See png_read_update_info(), below.
+A quick word about text_ptr and num_text.  PNG stores comments in
+keyword/text pairs, one pair per chunk, with no limit on the number
+of text chunks, and a 2^31 byte limit on their size.  While there are
+suggested keywords, there is no requirement to restrict the use to these
+strings.  It is strongly suggested that keywords and text be sensible
+to humans (that's the point), so don't use abbreviations.  Non-printing
+symbols are not allowed.  See the PNG specification for more details.
+There is also no requirement to have text after the keyword.
+Keywords should be limited to 79 Latin-1 characters without leading or
+trailing spaces, but non-consecutive spaces are allowed within the
+keyword.  It is possible to have the same keyword any number of times.
+The text_ptr is an array of png_text structures, each holding a
+pointer to a language string, a pointer to a keyword and a pointer to
+a text string.  The text string, language code, and translated
+keyword may be empty or NULL pointers.  The keyword/text
+pairs are put into the array in the order that they are received.
+However, some or all of the text chunks may be after the image, so, to
+make sure you have read all the text chunks, don't mess with these
+until after you read the stuff after the image.  This will be
+mentioned again below in the discussion that goes with png_read_end().
+Input transformations
+After you've read the header information, you can set up the library
+to handle any special transformations of the image data.  The various
+ways to transform the data will be described in the order that they
+should occur.  This is important, as some of these change the color
+type and/or bit depth of the data, and some others only work on
+certain color types and bit depths.
+Transformations you request are ignored if they don't have any meaning for a
+particular input data format.  However some transformations can have an effect
+as a result of a previous transformation.  If you specify a contradictory set of
+transformations, for example both adding and removing the alpha channel, you
+cannot predict the final result.
+The color used for the transparency values should be supplied in the same
+format/depth as the current image data.  It is stored in the same format/depth
+as the image data in a tRNS chunk, so this is what libpng expects for this data.
+The color used for the background value depends on the need_expand argument as
+described below.
+Data will be decoded into the supplied row buffers packed into bytes
+unless the library has been told to transform it into another format.
+For example, 4 bit/pixel paletted or grayscale data will be returned
+2 pixels/byte with the leftmost pixel in the high-order bits of the
+byte, unless png_set_packing() is called.  8-bit RGB data will be stored
+in RGB RGB RGB format unless png_set_filler() or png_set_add_alpha()
+is called to insert filler bytes, either before or after each RGB triplet.
+16-bit RGB data will be returned RRGGBB RRGGBB, with the most significant
+byte of the color value first, unless png_set_scale_16() is called to
+transform it to regular RGB RGB triplets, or png_set_filler() or
+png_set_add alpha() is called to insert filler bytes, either before or
+after each RRGGBB triplet.  Similarly, 8-bit or 16-bit grayscale data can
+be modified with png_set_filler(), png_set_add_alpha(), png_set_strip_16(),
+or png_set_scale_16().
+The following code transforms grayscale images of less than 8 to 8 bits,
+changes paletted images to RGB, and adds a full alpha channel if there is
+transparency information in a tRNS chunk.  This is most useful on
+grayscale images with bit depths of 2 or 4 or if there is a multiple-image
+viewing application that wishes to treat all images in the same way.
+    if (color_type == PNG_COLOR_TYPE_PALETTE)
+        png_set_palette_to_rgb(png_ptr);
+    if (png_get_valid(png_ptr, info_ptr,
+        PNG_INFO_tRNS)) png_set_tRNS_to_alpha(png_ptr);
+    if (color_type == PNG_COLOR_TYPE_GRAY &&
+        bit_depth < 8) png_set_expand_gray_1_2_4_to_8(png_ptr);
+The first two functions are actually aliases for png_set_expand(), added
+in libpng version 1.0.4, with the function names expanded to improve code
+readability.  In some future version they may actually do different
+things.
+As of libpng version 1.2.9, png_set_expand_gray_1_2_4_to_8() was
+added.  It expands the sample depth without changing tRNS to alpha.
+As of libpng version 1.5.2, png_set_expand_16() was added.  It behaves as
+png_set_expand(); however, the resultant channels have 16 bits rather than 8.
+Use this when the output color or gray channels are made linear to avoid fairly
+severe accuracy loss.
+   if (bit_depth < 16)
+      png_set_expand_16(png_ptr);
+PNG can have files with 16 bits per channel.  If you only can handle
+8 bits per channel, this will strip the pixels down to 8-bit.
+    if (bit_depth == 16)
+#if PNG_LIBPNG_VER >= 10504
+       png_set_scale_16(png_ptr);
+#else
+       png_set_strip_16(png_ptr);
+#endif
+(The more accurate "png_set_scale_16()" API became available in libpng version
+1.5.4).
+If you need to process the alpha channel on the image separately from the image
+data (for example if you convert it to a bitmap mask) it is possible to have
+libpng strip the channel leaving just RGB or gray data:
+    if (color_type & PNG_COLOR_MASK_ALPHA)
+       png_set_strip_alpha(png_ptr);
+If you strip the alpha channel you need to find some other way of dealing with
+the information.  If, instead, you want to convert the image to an opaque
+version with no alpha channel use png_set_background; see below.
+As of libpng version 1.5.2, almost all useful expansions are supported, the
+major ommissions are conversion of grayscale to indexed images (which can be
+done trivially in the application) and conversion of indexed to grayscale (which
+can be done by a trivial manipulation of the palette.)
+In the following table, the 01 means grayscale with depth<8, 31 means
+indexed with depth<8, other numerals represent the color type, "T" means
+the tRNS chunk is present, A means an alpha channel is present, and O
+means tRNS or alpha is present but all pixels in the image are opaque.
+  FROM  01  31   0  0T  0O   2  2T  2O   3  3T  3O  4A  4O  6A  6O
+   TO
+   01    -  [G]  -   -   -   -   -   -   -   -   -   -   -   -   -
+   31   [Q]  Q  [Q] [Q] [Q]  Q   Q   Q   Q   Q   Q  [Q] [Q]  Q   Q
+    0    1   G   +   .   .   G   G   G   G   G   G   B   B  GB  GB
+   0T    lt  Gt  t   +   .   Gt  G   G   Gt  G   G   Bt  Bt GBt GBt
+   0O    lt  Gt  t   .   +   Gt  Gt  G   Gt  Gt  G   Bt  Bt GBt GBt
+    2    C   P   C   C   C   +   .   .   C   -   -  CB  CB   B   B
+   2T    Ct  -   Ct  C   C   t   +   t   -   -   -  CBt CBt  Bt  Bt
+   2O    Ct  -   Ct  C   C   t   t   +   -   -   -  CBt CBt  Bt  Bt
+    3   [Q]  p  [Q] [Q] [Q]  Q   Q   Q   +   .   .  [Q] [Q]  Q   Q
+   3T   [Qt] p  [Qt][Q] [Q]  Qt  Qt  Qt  t   +   t  [Qt][Qt] Qt  Qt
+   3O   [Qt] p  [Qt][Q] [Q]  Qt  Qt  Qt  t   t   +  [Qt][Qt] Qt  Qt
+   4A    lA  G   A   T   T   GA  GT  GT  GA  GT  GT  +   BA  G  GBA
+   4O    lA GBA  A   T   T   GA  GT  GT  GA  GT  GT  BA  +  GBA  G
+   6A    CA  PA  CA  C   C   A   T  tT   PA  P   P   C  CBA  +   BA
+   6O    CA PBA  CA  C   C   A  tT   T   PA  P   P  CBA  C   BA  +
+Within the matrix,
+     "+" identifies entries where 'from' and 'to' are the same.
+     "-" means the transformation is not supported.
+     "." means nothing is necessary (a tRNS chunk can just be ignored).
+     "t" means the transformation is obtained by png_set_tRNS.
+     "A" means the transformation is obtained by png_set_add_alpha().
+     "X" means the transformation is obtained by png_set_expand().
+     "1" means the transformation is obtained by
+         png_set_expand_gray_1_2_4_to_8() (and by png_set_expand() if there
+         is no transparency in the original or the final format).
+     "C" means the transformation is obtained by png_set_gray_to_rgb().
+     "G" means the transformation is obtained by png_set_rgb_to_gray().
+     "P" means the transformation is obtained by
+         png_set_expand_palette_to_rgb().
+     "p" means the transformation is obtained by png_set_packing().
+     "Q" means the transformation is obtained by png_set_quantize().
+     "T" means the transformation is obtained by png_set_tRNS_to_alpha().
+     "B" means the transformation is obtained by png_set_background(), or
+         png_strip_alpha().
+When an entry has multiple transforms listed all are required to cause the
+right overall transformation.  When two transforms are separated by a comma
+either will do the job.  When transforms are enclosed in [] the transform should
+do the job but this is currently unimplemented - a different format will result
+if the suggested transformations are used.
+In PNG files, the alpha channel in an image
+is the level of opacity.  If you need the alpha channel in an image to
+be the level of transparency instead of opacity, you can invert the
+alpha channel (or the tRNS chunk data) after it's read, so that 0 is
+fully opaque and 255 (in 8-bit or paletted images) or 65535 (in 16-bit
+images) is fully transparent, with
+    png_set_invert_alpha(png_ptr);
+PNG files pack pixels of bit depths 1, 2, and 4 into bytes as small as
+they can, resulting in, for example, 8 pixels per byte for 1 bit
+files.  This code expands to 1 pixel per byte without changing the
+values of the pixels:
+    if (bit_depth < 8)
+       png_set_packing(png_ptr);
+PNG files have possible bit depths of 1, 2, 4, 8, and 16.  All pixels
+stored in a PNG image have been "scaled" or "shifted" up to the next
+higher possible bit depth (e.g. from 5 bits/sample in the range [0,31]
+to 8 bits/sample in the range [0, 255]).  However, it is also possible
+to convert the PNG pixel data back to the original bit depth of the
+image.  This call reduces the pixels back down to the original bit depth:
+    png_color_8p sig_bit;
+    if (png_get_sBIT(png_ptr, info_ptr, &sig_bit))
+       png_set_shift(png_ptr, sig_bit);
+PNG files store 3-color pixels in red, green, blue order.  This code
+changes the storage of the pixels to blue, green, red:
+    if (color_type == PNG_COLOR_TYPE_RGB ||
+        color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+       png_set_bgr(png_ptr);
+PNG files store RGB pixels packed into 3 or 6 bytes. This code expands them
+into 4 or 8 bytes for windowing systems that need them in this format:
+    if (color_type == PNG_COLOR_TYPE_RGB)
+       png_set_filler(png_ptr, filler, PNG_FILLER_BEFORE);
+where "filler" is the 8 or 16-bit number to fill with, and the location is
+either PNG_FILLER_BEFORE or PNG_FILLER_AFTER, depending upon whether
+you want the filler before the RGB or after.  This transformation
+does not affect images that already have full alpha channels.  To add an
+opaque alpha channel, use filler=0xff or 0xffff and PNG_FILLER_AFTER which
+will generate RGBA pixels.
+Note that png_set_filler() does not change the color type.  If you want
+to do that, you can add a true alpha channel with
+    if (color_type == PNG_COLOR_TYPE_RGB ||
+       color_type == PNG_COLOR_TYPE_GRAY)
+       png_set_add_alpha(png_ptr, filler, PNG_FILLER_AFTER);
+where "filler" contains the alpha value to assign to each pixel.
+This function was added in libpng-1.2.7.
+If you are reading an image with an alpha channel, and you need the
+data as ARGB instead of the normal PNG format RGBA:
+    if (color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+       png_set_swap_alpha(png_ptr);
+For some uses, you may want a grayscale image to be represented as
+RGB.  This code will do that conversion:
+    if (color_type == PNG_COLOR_TYPE_GRAY ||
+        color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+       png_set_gray_to_rgb(png_ptr);
+Conversely, you can convert an RGB or RGBA image to grayscale or grayscale
+with alpha.
+    if (color_type == PNG_COLOR_TYPE_RGB ||
+        color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+       png_set_rgb_to_gray(png_ptr, error_action, double red_weight,
+          double green_weight);
+    error_action = 1: silently do the conversion
+    error_action = 2: issue a warning if the original
+                      image has any pixel where
+                      red != green or red != blue
+    error_action = 3: issue an error and abort the
+                      conversion if the original
+                      image has any pixel where
+                      red != green or red != blue
+    red_weight:       weight of red component
+    green_weight:     weight of green component
+                      If either weight is negative, default
+                      weights are used.
+In the corresponding fixed point API the red_weight and green_weight values are
+simply scaled by 100,000:
+    png_set_rgb_to_gray(png_ptr, error_action, png_fixed_point red_weight,
+       png_fixed_point green_weight);
+If you have set error_action = 1 or 2, you can
+later check whether the image really was gray, after processing
+the image rows, with the png_get_rgb_to_gray_status(png_ptr) function.
+It will return a png_byte that is zero if the image was gray or
+1 if there were any non-gray pixels.  Background and sBIT data
+will be silently converted to grayscale, using the green channel
+data for sBIT, regardless of the error_action setting.
+The default values come from the PNG file cHRM chunk if present; otherwise, the
+defaults correspond to the ITU-R recommendation 709, and also the sRGB color
+space, as recommended in the Charles Poynton's Colour FAQ,
+<http://www.poynton.com/>, in section 9:
+   <http://www.poynton.com/notes/colour_and_gamma/ColorFAQ.html#RTFToC9>
+    Y = 0.2126 * R + 0.7152 * G + 0.0722 * B
+Previous versions of this document, 1998 through 2002, recommended a slightly
+different formula:
+    Y = 0.212671 * R + 0.715160 * G + 0.072169 * B
+Libpng uses an integer approximation:
+    Y = (6968 * R + 23434 * G + 2366 * B)/32768
+The calculation is done in a linear colorspace, if the image gamma
+can be determined.
+The png_set_background() function has been described already; it tells libpng to
+composite images with alpha or simple transparency against the supplied
+background color.  For compatibility with versions of libpng earlier than
+libpng-1.5.4 it is recommended that you call the function after reading the file
+header, even if you don't want to use the color in a bKGD chunk, if one exists.
+If the PNG file contains a bKGD chunk (PNG_INFO_bKGD valid),
+you may use this color, or supply another color more suitable for
+the current display (e.g., the background color from a web page).  You
+need to tell libpng how the color is represented, both the format of the
+component values in the color (the number of bits) and the gamma encoding of the
+color.  The function takes two arguments, background_gamma_mode and need_expand
+to convey this information, however only two combinations are likely to be
+useful:
+    png_color_16 my_background;
+    png_color_16p image_background;
+    if (png_get_bKGD(png_ptr, info_ptr, &image_background))
+       png_set_background(png_ptr, image_background,
+           PNG_BACKGROUND_GAMMA_FILE, 1/*needs to be expanded*/, 1);
+    else
+       png_set_background(png_ptr, &my_background,
+           PNG_BACKGROUND_GAMMA_SCREEN, 0/*do not expand*/, 1);
+The second call was described above - my_background is in the format of the
+final, display, output produced by libpng.  Because you now know the format of
+the PNG it is possible to avoid the need to choose either 8-bit or 16-bit
+output and to retain palette images (the palette colors will be modified
+appropriately and the tRNS chunk removed.)  However, if you are doing this,
+take great care not to ask for transformations without checking first that
+they apply!
+In the first call the background color has the original bit depth and color type
+of the PNG file.  So, for palette images the color is supplied as a palette
+index and for low bit greyscale images the color is a reduced bit value in
+image_background->gray.
+If you didn't call png_set_gamma() before reading the file header, for example
+if you need your code to remain compatible with older versions of libpng prior
+to libpng-1.5.4, this is the place to call it.
+Do not call it if you called png_set_alpha_mode(); doing so will damage the
+settings put in place by png_set_alpha_mode().  (If png_set_alpha_mode() is
+supported then you can certainly do png_set_gamma() before reading the PNG
+header.)
+This API unconditionally sets the screen and file gamma values, so it will
+override the value in the PNG file unless it is called before the PNG file
+reading starts.  For this reason you must always call it with the PNG file
+value when you call it in this position:
+   if (png_get_gAMA(png_ptr, info_ptr, &file_gamma))
+      png_set_gamma(png_ptr, screen_gamma, file_gamma);
+   else
+      png_set_gamma(png_ptr, screen_gamma, 0.45455);
+If you need to reduce an RGB file to a paletted file, or if a paletted
+file has more entries then will fit on your screen, png_set_quantize()
+will do that.  Note that this is a simple match quantization that merely
+finds the closest color available.  This should work fairly well with
+optimized palettes, but fairly badly with linear color cubes.  If you
+pass a palette that is larger than maximum_colors, the file will
+reduce the number of colors in the palette so it will fit into
+maximum_colors.  If there is a histogram, libpng will use it to make
+more intelligent choices when reducing the palette.  If there is no
+histogram, it may not do as good a job.
+   if (color_type & PNG_COLOR_MASK_COLOR)
+   {
+      if (png_get_valid(png_ptr, info_ptr,
+          PNG_INFO_PLTE))
+      {
+         png_uint_16p histogram = NULL;
+         png_get_hIST(png_ptr, info_ptr,
+             &histogram);
+         png_set_quantize(png_ptr, palette, num_palette,
+            max_screen_colors, histogram, 1);
+      }
+      else
+      {
+         png_color std_color_cube[MAX_SCREEN_COLORS] =
+            { ... colors ... };
+         png_set_quantize(png_ptr, std_color_cube,
+            MAX_SCREEN_COLORS, MAX_SCREEN_COLORS,
+            NULL,0);
+      }
+   }
+PNG files describe monochrome as black being zero and white being one.
+The following code will reverse this (make black be one and white be
+zero):
+   if (bit_depth == 1 && color_type == PNG_COLOR_TYPE_GRAY)
+      png_set_invert_mono(png_ptr);
+This function can also be used to invert grayscale and gray-alpha images:
+   if (color_type == PNG_COLOR_TYPE_GRAY ||
+       color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+      png_set_invert_mono(png_ptr);
+PNG files store 16-bit pixels in network byte order (big-endian,
+ie. most significant bits first).  This code changes the storage to the
+other way (little-endian, i.e. least significant bits first, the
+way PCs store them):
+    if (bit_depth == 16)
+       png_set_swap(png_ptr);
+If you are using packed-pixel images (1, 2, or 4 bits/pixel), and you
+need to change the order the pixels are packed into bytes, you can use:
+    if (bit_depth < 8)
+       png_set_packswap(png_ptr);
+Finally, you can write your own transformation function if none of
+the existing ones meets your needs.  This is done by setting a callback
+with
+    png_set_read_user_transform_fn(png_ptr,
+        read_transform_fn);
+You must supply the function
+    void read_transform_fn(png_structp png_ptr, png_row_infop
+        row_info, png_bytep data)
+See pngtest.c for a working example.  Your function will be called
+after all of the other transformations have been processed.  Take care with
+interlaced images if you do the interlace yourself - the width of the row is the
+width in 'row_info', not the overall image width.
+If supported, libpng provides two information routines that you can use to find
+where you are in processing the image:
+   png_get_current_pass_number(png_structp png_ptr);
+   png_get_current_row_number(png_structp png_ptr);
+Don't try using these outside a transform callback - firstly they are only
+supported if user transforms are supported, secondly they may well return
+unexpected results unless the row is actually being processed at the moment they
+are called.
+With interlaced
+images the value returned is the row in the input sub-image image.  Use
+PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
+find the output pixel (x,y) given an interlaced sub-image pixel (row,col,pass).
+The discussion of interlace handling above contains more information on how to
+use these values.
+You can also set up a pointer to a user structure for use by your
+callback function, and you can inform libpng that your transform
+function will change the number of channels or bit depth with the
+function
+    png_set_user_transform_info(png_ptr, user_ptr,
+        user_depth, user_channels);
+The user's application, not libpng, is responsible for allocating and
+freeing any memory required for the user structure.
+You can retrieve the pointer via the function
+png_get_user_transform_ptr().  For example:
+    voidp read_user_transform_ptr =
+        png_get_user_transform_ptr(png_ptr);
+The last thing to handle is interlacing; this is covered in detail below,
+but you must call the function here if you want libpng to handle expansion
+of the interlaced image.
+    number_of_passes = png_set_interlace_handling(png_ptr);
+After setting the transformations, libpng can update your png_info
+structure to reflect any transformations you've requested with this
+call.
+    png_read_update_info(png_ptr, info_ptr);
+This is most useful to update the info structure's rowbytes
+field so you can use it to allocate your image memory.  This function
+will also update your palette with the correct screen_gamma and
+background if these have been given with the calls above.  You may
+only call png_read_update_info() once with a particular info_ptr.
+After you call png_read_update_info(), you can allocate any
+memory you need to hold the image.  The row data is simply
+raw byte data for all forms of images.  As the actual allocation
+varies among applications, no example will be given.  If you
+are allocating one large chunk, you will need to build an
+array of pointers to each row, as it will be needed for some
+of the functions below.
+Remember: Before you call png_read_update_info(), the png_get_*()
+functions return the values corresponding to the original PNG image.
+After you call png_read_update_info the values refer to the image
+that libpng will output.  Consequently you must call all the png_set_
+functions before you call png_read_update_info().  This is particularly
+important for png_set_interlace_handling() - if you are going to call
+png_read_update_info() you must call png_set_interlace_handling() before
+it unless you want to receive interlaced output.
+Reading image data
+After you've allocated memory, you can read the image data.
+The simplest way to do this is in one function call.  If you are
+allocating enough memory to hold the whole image, you can just
+call png_read_image() and libpng will read in all the image data
+and put it in the memory area supplied.  You will need to pass in
+an array of pointers to each row.
+This function automatically handles interlacing, so you don't
+need to call png_set_interlace_handling() (unless you call
+png_read_update_info()) or call this function multiple times, or any
+of that other stuff necessary with png_read_rows().
+   png_read_image(png_ptr, row_pointers);
+where row_pointers is:
+   png_bytep row_pointers[height];
+You can point to void or char or whatever you use for pixels.
+If you don't want to read in the whole image at once, you can
+use png_read_rows() instead.  If there is no interlacing (check
+interlace_type == PNG_INTERLACE_NONE), this is simple:
+    png_read_rows(png_ptr, row_pointers, NULL,
+        number_of_rows);
+where row_pointers is the same as in the png_read_image() call.
+If you are doing this just one row at a time, you can do this with
+a single row_pointer instead of an array of row_pointers:
+    png_bytep row_pointer = row;
+    png_read_row(png_ptr, row_pointer, NULL);
+If the file is interlaced (interlace_type != 0 in the IHDR chunk), things
+get somewhat harder.  The only current (PNG Specification version 1.2)
+interlacing type for PNG is (interlace_type == PNG_INTERLACE_ADAM7);
+a somewhat complicated 2D interlace scheme, known as Adam7, that
+breaks down an image into seven smaller images of varying size, based
+on an 8x8 grid.  This number is defined (from libpng 1.5) as
+PNG_INTERLACE_ADAM7_PASSES in png.h
+libpng can fill out those images or it can give them to you "as is".
+It is almost always better to have libpng handle the interlacing for you.
+If you want the images filled out, there are two ways to do that.  The one
+mentioned in the PNG specification is to expand each pixel to cover
+those pixels that have not been read yet (the "rectangle" method).
+This results in a blocky image for the first pass, which gradually
+smooths out as more pixels are read.  The other method is the "sparkle"
+method, where pixels are drawn only in their final locations, with the
+rest of the image remaining whatever colors they were initialized to
+before the start of the read.  The first method usually looks better,
+but tends to be slower, as there are more pixels to put in the rows.
+If, as is likely, you want libpng to expand the images, call this before
+calling png_start_read_image() or png_read_update_info():
+    if (interlace_type == PNG_INTERLACE_ADAM7)
+       number_of_passes
+           = png_set_interlace_handling(png_ptr);
+This will return the number of passes needed.  Currently, this is seven,
+but may change if another interlace type is added.  This function can be
+called even if the file is not interlaced, where it will return one pass.
+You then need to read the whole image 'number_of_passes' times.  Each time
+will distribute the pixels from the current pass to the correct place in
+the output image, so you need to supply the same rows to png_read_rows in
+each pass.
+If you are not going to display the image after each pass, but are
+going to wait until the entire image is read in, use the sparkle
+effect.  This effect is faster and the end result of either method
+is exactly the same.  If you are planning on displaying the image
+after each pass, the "rectangle" effect is generally considered the
+better looking one.
+If you only want the "sparkle" effect, just call png_read_rows() as
+normal, with the third parameter NULL.  Make sure you make pass over
+the image number_of_passes times, and you don't change the data in the
+rows between calls.  You can change the locations of the data, just
+not the data.  Each pass only writes the pixels appropriate for that
+pass, and assumes the data from previous passes is still valid.
+    png_read_rows(png_ptr, row_pointers, NULL,
+        number_of_rows);
+If you only want the first effect (the rectangles), do the same as
+before except pass the row buffer in the third parameter, and leave
+the second parameter NULL.
+    png_read_rows(png_ptr, NULL, row_pointers,
+        number_of_rows);
+If you don't want libpng to handle the interlacing details, just call
+png_read_rows() PNG_INTERLACE_ADAM7_PASSES times to read in all the images.
+Each of the images is a valid image by itself, however you will almost
+certainly need to distribute the pixels from each sub-image to the
+correct place.  This is where everything gets very tricky.
+If you want to retrieve the separate images you must pass the correct
+number of rows to each successive call of png_read_rows().  The calculation
+gets pretty complicated for small images, where some sub-images may
+not even exist because either their width or height ends up zero.
+libpng provides two macros to help you in 1.5 and later versions:
+   png_uint_32 width = PNG_PASS_COLS(image_width, pass_number);
+   png_uint_32 height = PNG_PASS_ROWS(image_height, pass_number);
+Respectively these tell you the width and height of the sub-image
+corresponding to the numbered pass.  'pass' is in in the range 0 to 6 -
+this can be confusing because the specification refers to the same passes
+as 1 to 7!  Be careful, you must check both the width and height before
+calling png_read_rows() and not call it for that pass if either is zero.
+You can, of course, read each sub-image row by row.  If you want to
+produce optimal code to make a pixel-by-pixel transformation of an
+interlaced image this is the best approach; read each row of each pass,
+transform it, and write it out to a new interlaced image.
+If you want to de-interlace the image yourself libpng provides further
+macros to help that tell you where to place the pixels in the output image.
+Because the interlacing scheme is rectangular - sub-image pixels are always
+arranged on a rectangular grid - all you need to know for each pass is the
+starting column and row in the output image of the first pixel plus the
+spacing between each pixel.  As of libpng 1.5 there are four macros to
+retrieve this information:
+   png_uint_32 x = PNG_PASS_START_COL(pass);
+   png_uint_32 y = PNG_PASS_START_ROW(pass);
+   png_uint_32 xStep = 1U << PNG_PASS_COL_SHIFT(pass);
+   png_uint_32 yStep = 1U << PNG_PASS_ROW_SHIFT(pass);
+These allow you to write the obvious loop:
+   png_uint_32 input_y = 0;
+   png_uint_32 output_y = PNG_PASS_START_ROW(pass);
+   while (output_y < output_image_height)
+   {
+      png_uint_32 input_x = 0;
+      png_uint_32 output_x = PNG_PASS_START_COL(pass);
+      while (output_x < output_image_width)
+      {
+         image[output_y][output_x] =
+             subimage[pass][input_y][input_x++];
+         output_x += xStep;
+      }
+      ++input_y;
+      output_y += yStep;
+   }
+Notice that the steps between successive output rows and columns are
+returned as shifts.  This is possible because the pixels in the subimages
+are always a power of 2 apart - 1, 2, 4 or 8 pixels - in the original
+image.  In practice you may need to directly calculate the output coordinate
+given an input coordinate.  libpng provides two further macros for this
+purpose:
+   png_uint_32 output_x = PNG_COL_FROM_PASS_COL(input_x, pass);
+   png_uint_32 output_y = PNG_ROW_FROM_PASS_ROW(input_y, pass);
+Finally a pair of macros are provided to tell you if a particular image
+row or column appears in a given pass:
+   int col_in_pass = PNG_COL_IN_INTERLACE_PASS(output_x, pass);
+   int row_in_pass = PNG_ROW_IN_INTERLACE_PASS(output_y, pass);
+Bear in mind that you will probably also need to check the width and height
+of the pass in addition to the above to be sure the pass even exists!
+With any luck you are convinced by now that you don't want to do your own
+interlace handling.  In reality normally the only good reason for doing this
+is if you are processing PNG files on a pixel-by-pixel basis and don't want
+to load the whole file into memory when it is interlaced.
+libpng includes a test program, pngvalid, that illustrates reading and
+writing of interlaced images.  If you can't get interlacing to work in your
+code and don't want to leave it to libpng (the recommended approach), see
+how pngvalid.c does it.
+Finishing a sequential read
+After you are finished reading the image through the
+low-level interface, you can finish reading the file.  If you are
+interested in comments or time, which may be stored either before or
+after the image data, you should pass the separate png_info struct if
+you want to keep the comments from before and after the image
+separate.
+    png_infop end_info = png_create_info_struct(png_ptr);
+    if (!end_info)
+    {
+       png_destroy_read_struct(&png_ptr, &info_ptr,
+           (png_infopp)NULL);
+       return (ERROR);
+    }
+   png_read_end(png_ptr, end_info);
+If you are not interested, you should still call png_read_end()
+but you can pass NULL, avoiding the need to create an end_info structure.
+   png_read_end(png_ptr, (png_infop)NULL);
+If you don't call png_read_end(), then your file pointer will be
+left pointing to the first chunk after the last IDAT, which is probably
+not what you want if you expect to read something beyond the end of
+the PNG datastream.
+When you are done, you can free all memory allocated by libpng like this:
+   png_destroy_read_struct(&png_ptr, &info_ptr,
+       &end_info);
+or, if you didn't create an end_info structure,
+   png_destroy_read_struct(&png_ptr, &info_ptr,
+       (png_infopp)NULL);
+It is also possible to individually free the info_ptr members that
+point to libpng-allocated storage with the following function:
+    png_free_data(png_ptr, info_ptr, mask, seq)
+    mask - identifies data to be freed, a mask
+           containing the bitwise OR of one or
+           more of
+             PNG_FREE_PLTE, PNG_FREE_TRNS,
+             PNG_FREE_HIST, PNG_FREE_ICCP,
+             PNG_FREE_PCAL, PNG_FREE_ROWS,
+             PNG_FREE_SCAL, PNG_FREE_SPLT,
+             PNG_FREE_TEXT, PNG_FREE_UNKN,
+           or simply PNG_FREE_ALL
+    seq  - sequence number of item to be freed
+           (-1 for all items)
+This function may be safely called when the relevant storage has
+already been freed, or has not yet been allocated, or was allocated
+by the user and not by libpng,  and will in those cases do nothing.
+The "seq" parameter is ignored if only one item of the selected data
+type, such as PLTE, is allowed.  If "seq" is not -1, and multiple items
+are allowed for the data type identified in the mask, such as text or
+sPLT, only the n'th item in the structure is freed, where n is "seq".
+The default behavior is only to free data that was allocated internally
+by libpng.  This can be changed, so that libpng will not free the data,
+or so that it will free data that was allocated by the user with png_malloc()
+or png_zalloc() and passed in via a png_set_*() function, with
+    png_data_freer(png_ptr, info_ptr, freer, mask)
+    freer  - one of
+               PNG_DESTROY_WILL_FREE_DATA
+               PNG_SET_WILL_FREE_DATA
+               PNG_USER_WILL_FREE_DATA
+    mask   - which data elements are affected
+             same choices as in png_free_data()
+This function only affects data that has already been allocated.
+You can call this function after reading the PNG data but before calling
+any png_set_*() functions, to control whether the user or the png_set_*()
+function is responsible for freeing any existing data that might be present,
+and again after the png_set_*() functions to control whether the user
+or png_destroy_*() is supposed to free the data.  When the user assumes
+responsibility for libpng-allocated data, the application must use
+png_free() to free it, and when the user transfers responsibility to libpng
+for data that the user has allocated, the user must have used png_malloc()
+or png_zalloc() to allocate it.
+If you allocated your row_pointers in a single block, as suggested above in
+the description of the high level read interface, you must not transfer
+responsibility for freeing it to the png_set_rows or png_read_destroy function,
+because they would also try to free the individual row_pointers[i].
+If you allocated text_ptr.text, text_ptr.lang, and text_ptr.translated_keyword
+separately, do not transfer responsibility for freeing text_ptr to libpng,
+because when libpng fills a png_text structure it combines these members with
+the key member, and png_free_data() will free only text_ptr.key.  Similarly,
+if you transfer responsibility for free'ing text_ptr from libpng to your
+application, your application must not separately free those members.
+The png_free_data() function will turn off the "valid" flag for anything
+it frees.  If you need to turn the flag off for a chunk that was freed by
+your application instead of by libpng, you can use
+    png_set_invalid(png_ptr, info_ptr, mask);
+    mask - identifies the chunks to be made invalid,
+           containing the bitwise OR of one or
+           more of
+             PNG_INFO_gAMA, PNG_INFO_sBIT,
+             PNG_INFO_cHRM, PNG_INFO_PLTE,
+             PNG_INFO_tRNS, PNG_INFO_bKGD,
+             PNG_INFO_hIST, PNG_INFO_pHYs,
+             PNG_INFO_oFFs, PNG_INFO_tIME,
+             PNG_INFO_pCAL, PNG_INFO_sRGB,
+             PNG_INFO_iCCP, PNG_INFO_sPLT,
+             PNG_INFO_sCAL, PNG_INFO_IDAT
+For a more compact example of reading a PNG image, see the file example.c.
+Reading PNG files progressively
+The progressive reader is slightly different then the non-progressive
+reader.  Instead of calling png_read_info(), png_read_rows(), and
+png_read_end(), you make one call to png_process_data(), which calls
+callbacks when it has the info, a row, or the end of the image.  You
+set up these callbacks with png_set_progressive_read_fn().  You don't
+have to worry about the input/output functions of libpng, as you are
+giving the library the data directly in png_process_data().  I will
+assume that you have read the section on reading PNG files above,
+so I will only highlight the differences (although I will show
+all of the code).
+png_structp png_ptr;
+png_infop info_ptr;
+ /*  An example code fragment of how you would
+     initialize the progressive reader in your
+     application. */
+ int
+ initialize_png_reader()
+ {
+    png_ptr = png_create_read_struct
+        (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
+         user_error_fn, user_warning_fn);
+    if (!png_ptr)
+        return (ERROR);
+    info_ptr = png_create_info_struct(png_ptr);
+    if (!info_ptr)
+    {
+       png_destroy_read_struct(&png_ptr,
+          (png_infopp)NULL, (png_infopp)NULL);
+       return (ERROR);
+    }
+    if (setjmp(png_jmpbuf(png_ptr)))
+    {
+       png_destroy_read_struct(&png_ptr, &info_ptr,
+          (png_infopp)NULL);
+       return (ERROR);
+    }
+    /* This one's new.  You can provide functions
+       to be called when the header info is valid,
+       when each row is completed, and when the image
+       is finished.  If you aren't using all functions,
+       you can specify NULL parameters.  Even when all
+       three functions are NULL, you need to call
+       png_set_progressive_read_fn().  You can use
+       any struct as the user_ptr (cast to a void pointer
+       for the function call), and retrieve the pointer
+       from inside the callbacks using the function
+          png_get_progressive_ptr(png_ptr);
+       which will return a void pointer, which you have
+       to cast appropriately.
+     */
+    png_set_progressive_read_fn(png_ptr, (void *)user_ptr,
+        info_callback, row_callback, end_callback);
+    return 0;
+ }
+ /* A code fragment that you call as you receive blocks
+   of data */
+ int
+ process_data(png_bytep buffer, png_uint_32 length)
+ {
+    if (setjmp(png_jmpbuf(png_ptr)))
+    {
+       png_destroy_read_struct(&png_ptr, &info_ptr,
+           (png_infopp)NULL);
+       return (ERROR);
+    }
+    /* This one's new also.  Simply give it a chunk
+       of data from the file stream (in order, of
+       course).  On machines with segmented memory
+       models machines, don't give it any more than
+       64K.  The library seems to run fine with sizes
+       of 4K. Although you can give it much less if
+       necessary (I assume you can give it chunks of
+       1 byte, I haven't tried less then 256 bytes
+       yet).  When this function returns, you may
+       want to display any rows that were generated
+       in the row callback if you don't already do
+       so there.
+     */
+    png_process_data(png_ptr, info_ptr, buffer, length);
+    /* At this point you can call png_process_data_skip if
+       you want to handle data the library will skip yourself;
+       it simply returns the number of bytes to skip (and stops
+       libpng skipping that number of bytes on the next
+       png_process_data call).
+    return 0;
+ }
+ /* This function is called (as set by
+    png_set_progressive_read_fn() above) when enough data
+    has been supplied so all of the header has been
+    read.
+ */
+ void
+ info_callback(png_structp png_ptr, png_infop info)
+ {
+    /* Do any setup here, including setting any of
+       the transformations mentioned in the Reading
+       PNG files section.  For now, you _must_ call
+       either png_start_read_image() or
+       png_read_update_info() after all the
+       transformations are set (even if you don't set
+       any).  You may start getting rows before
+       png_process_data() returns, so this is your
+       last chance to prepare for that.
+       This is where you turn on interlace handling,
+       assuming you don't want to do it yourself.
+       If you need to you can stop the processing of
+       your original input data at this point by calling
+       png_process_data_pause.  This returns the number
+       of unprocessed bytes from the last png_process_data
+       call - it is up to you to ensure that the next call
+       sees these bytes again.  If you don't want to bother
+       with this you can get libpng to cache the unread
+       bytes by setting the 'save' parameter (see png.h) but
+       then libpng will have to copy the data internally.
+     */
+ }
+ /* This function is called when each row of image
+    data is complete */
+ void
+ row_callback(png_structp png_ptr, png_bytep new_row,
+    png_uint_32 row_num, int pass)
+ {
+    /* If the image is interlaced, and you turned
+       on the interlace handler, this function will
+       be called for every row in every pass.  Some
+       of these rows will not be changed from the
+       previous pass.  When the row is not changed,
+       the new_row variable will be NULL.  The rows
+       and passes are called in order, so you don't
+       really need the row_num and pass, but I'm
+       supplying them because it may make your life
+       easier.
+       If you did not turn on interlace handling then
+       the callback is called for each row of each
+       sub-image when the image is interlaced.  In this
+       case 'row_num' is the row in the sub-image, not
+       the row in the output image as it is in all other
+       cases.
+       For the non-NULL rows of interlaced images when
+       you have switched on libpng interlace handling,
+       you must call png_progressive_combine_row()
+       passing in the row and the old row.  You can
+       call this function for NULL rows (it will just
+       return) and for non-interlaced images (it just
+       does the memcpy for you) if it will make the
+       code easier.  Thus, you can just do this for
+       all cases if you switch on interlace handling;
+     */
+        png_progressive_combine_row(png_ptr, old_row,
+          new_row);
+    /* where old_row is what was displayed for
+       previously for the row.  Note that the first
+       pass (pass == 0, really) will completely cover
+       the old row, so the rows do not have to be
+       initialized.  After the first pass (and only
+       for interlaced images), you will have to pass
+       the current row, and the function will combine
+       the old row and the new row.
+       You can also call png_process_data_pause in this
+       callback - see above.
+    */
+ }
+ void
+ end_callback(png_structp png_ptr, png_infop info)
+ {
+    /* This function is called after the whole image
+       has been read, including any chunks after the
+       image (up to and including the IEND).  You
+       will usually have the same info chunk as you
+       had in the header, although some data may have
+       been added to the comments and time fields.
+       Most people won't do much here, perhaps setting
+       a flag that marks the image as finished.
+     */
+ }
+IV. Writing
+Much of this is very similar to reading.  However, everything of
+importance is repeated here, so you won't have to constantly look
+back up in the reading section to understand writing.
+Setup
+You will want to do the I/O initialization before you get into libpng,
+so if it doesn't work, you don't have anything to undo. If you are not
+using the standard I/O functions, you will need to replace them with
+custom writing functions.  See the discussion under Customizing libpng.
+    FILE *fp = fopen(file_name, "wb");
+    if (!fp)
+       return (ERROR);
+Next, png_struct and png_info need to be allocated and initialized.
+As these can be both relatively large, you may not want to store these
+on the stack, unless you have stack space to spare.  Of course, you
+will want to check if they return NULL.  If you are also reading,
+you won't want to name your read structure and your write structure
+both "png_ptr"; you can call them anything you like, such as
+"read_ptr" and "write_ptr".  Look at pngtest.c, for example.
+    png_structp png_ptr = png_create_write_struct
+       (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
+        user_error_fn, user_warning_fn);
+    if (!png_ptr)
+       return (ERROR);
+    png_infop info_ptr = png_create_info_struct(png_ptr);
+    if (!info_ptr)
+    {
+       png_destroy_write_struct(&png_ptr,
+           (png_infopp)NULL);
+       return (ERROR);
+    }
+If you want to use your own memory allocation routines,
+define PNG_USER_MEM_SUPPORTED and use
+png_create_write_struct_2() instead of png_create_write_struct():
+    png_structp png_ptr = png_create_write_struct_2
+       (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
+        user_error_fn, user_warning_fn, (png_voidp)
+        user_mem_ptr, user_malloc_fn, user_free_fn);
+After you have these structures, you will need to set up the
+error handling.  When libpng encounters an error, it expects to
+longjmp() back to your routine.  Therefore, you will need to call
+setjmp() and pass the png_jmpbuf(png_ptr).  If you
+write the file from different routines, you will need to update
+the png_jmpbuf(png_ptr) every time you enter a new routine that will
+call a png_*() function.  See your documentation of setjmp/longjmp
+for your compiler for more information on setjmp/longjmp.  See
+the discussion on libpng error handling in the Customizing Libpng
+section below for more information on the libpng error handling.
+    if (setjmp(png_jmpbuf(png_ptr)))
+    {
+    png_destroy_write_struct(&png_ptr, &info_ptr);
+       fclose(fp);
+       return (ERROR);
+    }
+    ...
+    return;
+If you would rather avoid the complexity of setjmp/longjmp issues,
+you can compile libpng with PNG_NO_SETJMP, in which case
+errors will result in a call to PNG_ABORT() which defaults to abort().
+You can #define PNG_ABORT() to a function that does something
+more useful than abort(), as long as your function does not
+return.
+Now you need to set up the output code.  The default for libpng is to
+use the C function fwrite().  If you use this, you will need to pass a
+valid FILE * in the function png_init_io().  Be sure that the file is
+opened in binary mode.  Again, if you wish to handle writing data in
+another way, see the discussion on libpng I/O handling in the Customizing
+Libpng section below.
+    png_init_io(png_ptr, fp);
+If you are embedding your PNG into a datastream such as MNG, and don't
+want libpng to write the 8-byte signature, or if you have already
+written the signature in your application, use
+    png_set_sig_bytes(png_ptr, 8);
+to inform libpng that it should not write a signature.
+Write callbacks
+At this point, you can set up a callback function that will be
+called after each row has been written, which you can use to control
+a progress meter or the like.  It's demonstrated in pngtest.c.
+You must supply a function
+    void write_row_callback(png_structp png_ptr, png_uint_32 row,
+       int pass);
+    {
+      /* put your code here */
+    }
+(You can give it another name that you like instead of "write_row_callback")
+To inform libpng about your function, use
+    png_set_write_status_fn(png_ptr, write_row_callback);
+When this function is called the row has already been completely processed and
+it has also been written out.  The 'row' and 'pass' refer to the next row to be
+handled.  For the
+non-interlaced case the row that was just handled is simply one less than the
+passed in row number, and pass will always be 0.  For the interlaced case the
+same applies unless the row value is 0, in which case the row just handled was
+the last one from one of the preceding passes.  Because interlacing may skip a
+pass you cannot be sure that the preceding pass is just 'pass-1', if you really
+need to know what the last pass is record (row,pass) from the callback and use
+the last recorded value each time.
+As with the user transform you can find the output row using the
+PNG_ROW_FROM_PASS_ROW macro.
+You now have the option of modifying how the compression library will
+run.  The following functions are mainly for testing, but may be useful
+in some cases, like if you need to write PNG files extremely fast and
+are willing to give up some compression, or if you want to get the
+maximum possible compression at the expense of slower writing.  If you
+have no special needs in this area, let the library do what it wants by
+not calling this function at all, as it has been tuned to deliver a good
+speed/compression ratio. The second parameter to png_set_filter() is
+the filter method, for which the only valid values are 0 (as of the
+July 1999 PNG specification, version 1.2) or 64 (if you are writing
+a PNG datastream that is to be embedded in a MNG datastream).  The third
+parameter is a flag that indicates which filter type(s) are to be tested
+for each scanline.  See the PNG specification for details on the specific
+filter types.
+    /* turn on or off filtering, and/or choose
+       specific filters.  You can use either a single
+       PNG_FILTER_VALUE_NAME or the bitwise OR of one
+       or more PNG_FILTER_NAME masks.
+     */
+    png_set_filter(png_ptr, 0,
+       PNG_FILTER_NONE  | PNG_FILTER_VALUE_NONE |
+       PNG_FILTER_SUB   | PNG_FILTER_VALUE_SUB  |
+       PNG_FILTER_UP    | PNG_FILTER_VALUE_UP   |
+       PNG_FILTER_AVG   | PNG_FILTER_VALUE_AVG  |
+       PNG_FILTER_PAETH | PNG_FILTER_VALUE_PAETH|
+       PNG_ALL_FILTERS);
+If an application wants to start and stop using particular filters during
+compression, it should start out with all of the filters (to ensure that
+the previous row of pixels will be stored in case it's needed later),
+and then add and remove them after the start of compression.
+If you are writing a PNG datastream that is to be embedded in a MNG
+datastream, the second parameter can be either 0 or 64.
+The png_set_compression_*() functions interface to the zlib compression
+library, and should mostly be ignored unless you really know what you are
+doing.  The only generally useful call is png_set_compression_level()
+which changes how much time zlib spends on trying to compress the image
+data.  See the Compression Library (zlib.h and algorithm.txt, distributed
+with zlib) for details on the compression levels.
+    #include zlib.h
+    /* Set the zlib compression level */
+    png_set_compression_level(png_ptr,
+        Z_BEST_COMPRESSION);
+    /* Set other zlib parameters for compressing IDAT */
+    png_set_compression_mem_level(png_ptr, 8);
+    png_set_compression_strategy(png_ptr,
+        Z_DEFAULT_STRATEGY);
+    png_set_compression_window_bits(png_ptr, 15);
+    png_set_compression_method(png_ptr, 8);
+    png_set_compression_buffer_size(png_ptr, 8192)
+    /* Set zlib parameters for text compression
+     * If you don't call these, the parameters
+     * fall back on those defined for IDAT chunks
+     */
+    png_set_text_compression_mem_level(png_ptr, 8);
+    png_set_text_compression_strategy(png_ptr,
+        Z_DEFAULT_STRATEGY);
+    png_set_text_compression_window_bits(png_ptr, 15);
+    png_set_text_compression_method(png_ptr, 8);
+Setting the contents of info for output
+You now need to fill in the png_info structure with all the data you
+wish to write before the actual image.  Note that the only thing you
+are allowed to write after the image is the text chunks and the time
+chunk (as of PNG Specification 1.2, anyway).  See png_write_end() and
+the latest PNG specification for more information on that.  If you
+wish to write them before the image, fill them in now, and flag that
+data as being valid.  If you want to wait until after the data, don't
+fill them until png_write_end().  For all the fields in png_info and
+their data types, see png.h.  For explanations of what the fields
+contain, see the PNG specification.
+Some of the more important parts of the png_info are:
+    png_set_IHDR(png_ptr, info_ptr, width, height,
+       bit_depth, color_type, interlace_type,
+       compression_type, filter_method)
+    width          - holds the width of the image
+                     in pixels (up to 2^31).
+    height         - holds the height of the image
+                     in pixels (up to 2^31).
+    bit_depth      - holds the bit depth of one of the
+                     image channels.
+                     (valid values are 1, 2, 4, 8, 16
+                     and depend also on the
+                     color_type.  See also significant
+                     bits (sBIT) below).
+    color_type     - describes which color/alpha
+                     channels are present.
+                     PNG_COLOR_TYPE_GRAY
+                        (bit depths 1, 2, 4, 8, 16)
+                     PNG_COLOR_TYPE_GRAY_ALPHA
+                        (bit depths 8, 16)
+                     PNG_COLOR_TYPE_PALETTE
+                        (bit depths 1, 2, 4, 8)
+                     PNG_COLOR_TYPE_RGB
+                        (bit_depths 8, 16)
+                     PNG_COLOR_TYPE_RGB_ALPHA
+                        (bit_depths 8, 16)
+                     PNG_COLOR_MASK_PALETTE
+                     PNG_COLOR_MASK_COLOR
+                     PNG_COLOR_MASK_ALPHA
+    interlace_type - PNG_INTERLACE_NONE or
+                     PNG_INTERLACE_ADAM7
+    compression_type - (must be
+                     PNG_COMPRESSION_TYPE_DEFAULT)
+    filter_method  - (must be PNG_FILTER_TYPE_DEFAULT
+                     or, if you are writing a PNG to
+                     be embedded in a MNG datastream,
+                     can also be
+                     PNG_INTRAPIXEL_DIFFERENCING)
+If you call png_set_IHDR(), the call must appear before any of the
+other png_set_*() functions, because they might require access to some of
+the IHDR settings.  The remaining png_set_*() functions can be called
+in any order.
+If you wish, you can reset the compression_type, interlace_type, or
+filter_method later by calling png_set_IHDR() again; if you do this, the
+width, height, bit_depth, and color_type must be the same in each call.
+    png_set_PLTE(png_ptr, info_ptr, palette,
+       num_palette);
+    palette        - the palette for the file
+                     (array of png_color)
+    num_palette    - number of entries in the palette
+    png_set_gAMA(png_ptr, info_ptr, file_gamma);
+    png_set_gAMA_fixed(png_ptr, info_ptr, int_file_gamma);
+    file_gamma     - the gamma at which the image was
+                     created (PNG_INFO_gAMA)
+    int_file_gamma - 100,000 times the gamma at which
+                     the image was created
+    png_set_cHRM(png_ptr, info_ptr,  white_x, white_y, red_x, red_y,
+                     green_x, green_y, blue_x, blue_y)
+    png_set_cHRM_XYZ(png_ptr, info_ptr, red_X, red_Y, red_Z, green_X,
+                     green_Y, green_Z, blue_X, blue_Y, blue_Z)
+    png_set_cHRM_fixed(png_ptr, info_ptr, int_white_x, int_white_y,
+                     int_red_x, int_red_y, int_green_x, int_green_y,
+                     int_blue_x, int_blue_y)
+    png_set_cHRM_XYZ_fixed(png_ptr, info_ptr, int_red_X, int_red_Y,
+                     int_red_Z, int_green_X, int_green_Y, int_green_Z,
+                     int_blue_X, int_blue_Y, int_blue_Z)
+    {white,red,green,blue}_{x,y}
+                     A color space encoding specified using the chromaticities
+                     of the end points and the white point.
+    {red,green,blue}_{X,Y,Z}
+                     A color space encoding specified using the encoding end
+                     points - the CIE tristimulus specification of the intended
+                     color of the red, green and blue channels in the PNG RGB
+                     data.  The white point is simply the sum of the three end
+                     points.
+    png_set_sRGB(png_ptr, info_ptr, srgb_intent);
+    srgb_intent    - the rendering intent
+                     (PNG_INFO_sRGB) The presence of
+                     the sRGB chunk means that the pixel
+                     data is in the sRGB color space.
+                     This chunk also implies specific
+                     values of gAMA and cHRM.  Rendering
+                     intent is the CSS-1 property that
+                     has been defined by the International
+                     Color Consortium
+                     (http://www.color.org).
+                     It can be one of
+                     PNG_sRGB_INTENT_SATURATION,
+                     PNG_sRGB_INTENT_PERCEPTUAL,
+                     PNG_sRGB_INTENT_ABSOLUTE, or
+                     PNG_sRGB_INTENT_RELATIVE.
+    png_set_sRGB_gAMA_and_cHRM(png_ptr, info_ptr,
+       srgb_intent);
+    srgb_intent    - the rendering intent
+                     (PNG_INFO_sRGB) The presence of the
+                     sRGB chunk means that the pixel
+                     data is in the sRGB color space.
+                     This function also causes gAMA and
+                     cHRM chunks with the specific values
+                     that are consistent with sRGB to be
+                     written.
+    png_set_iCCP(png_ptr, info_ptr, name, compression_type,
+                       profile, proflen);
+    name             - The profile name.
+    compression_type - The compression type; always
+                       PNG_COMPRESSION_TYPE_BASE for PNG 1.0.
+                       You may give NULL to this argument to
+                       ignore it.
+    profile          - International Color Consortium color
+                       profile data. May contain NULs.
+    proflen          - length of profile data in bytes.
+    png_set_sBIT(png_ptr, info_ptr, sig_bit);
+    sig_bit        - the number of significant bits for
+                     (PNG_INFO_sBIT) each of the gray, red,
+                     green, and blue channels, whichever are
+                     appropriate for the given color type
+                     (png_color_16)
+    png_set_tRNS(png_ptr, info_ptr, trans_alpha,
+       num_trans, trans_color);
+    trans_alpha    - array of alpha (transparency)
+                     entries for palette (PNG_INFO_tRNS)
+    num_trans      - number of transparent entries
+                     (PNG_INFO_tRNS)
+    trans_color    - graylevel or color sample values
+                     (in order red, green, blue) of the
+                     single transparent color for
+                     non-paletted images (PNG_INFO_tRNS)
+    png_set_hIST(png_ptr, info_ptr, hist);
+    hist           - histogram of palette (array of
+                     png_uint_16) (PNG_INFO_hIST)
+    png_set_tIME(png_ptr, info_ptr, mod_time);
+    mod_time       - time image was last modified
+                     (PNG_VALID_tIME)
+    png_set_bKGD(png_ptr, info_ptr, background);
+    background     - background color (of type
+                     png_color_16p) (PNG_VALID_bKGD)
+    png_set_text(png_ptr, info_ptr, text_ptr, num_text);
+    text_ptr       - array of png_text holding image
+                     comments
+    text_ptr[i].compression - type of compression used
+                 on "text" PNG_TEXT_COMPRESSION_NONE
+                           PNG_TEXT_COMPRESSION_zTXt
+                           PNG_ITXT_COMPRESSION_NONE
+                           PNG_ITXT_COMPRESSION_zTXt
+    text_ptr[i].key   - keyword for comment.  Must contain
+                 1-79 characters.
+    text_ptr[i].text  - text comments for current
+                         keyword.  Can be NULL or empty.
+    text_ptr[i].text_length - length of text string,
+                 after decompression, 0 for iTXt
+    text_ptr[i].itxt_length - length of itxt string,
+                 after decompression, 0 for tEXt/zTXt
+    text_ptr[i].lang  - language of comment (NULL or
+                         empty for unknown).
+    text_ptr[i].translated_keyword  - keyword in UTF-8 (NULL
+                         or empty for unknown).
+    Note that the itxt_length, lang, and lang_key
+    members of the text_ptr structure only exist when the
+    library is built with iTXt chunk support.  Prior to
+    libpng-1.4.0 the library was built by default without
+    iTXt support. Also note that when iTXt is supported,
+    they contain NULL pointers when the "compression"
+    field contains PNG_TEXT_COMPRESSION_NONE or
+    PNG_TEXT_COMPRESSION_zTXt.
+    num_text       - number of comments
+    png_set_sPLT(png_ptr, info_ptr, &palette_ptr,
+       num_spalettes);
+    palette_ptr    - array of png_sPLT_struct structures
+                     to be added to the list of palettes
+                     in the info structure.
+    num_spalettes  - number of palette structures to be
+                     added.
+    png_set_oFFs(png_ptr, info_ptr, offset_x, offset_y,
+        unit_type);
+    offset_x  - positive offset from the left
+                     edge of the screen
+    offset_y  - positive offset from the top
+                     edge of the screen
+    unit_type - PNG_OFFSET_PIXEL, PNG_OFFSET_MICROMETER
+    png_set_pHYs(png_ptr, info_ptr, res_x, res_y,
+        unit_type);
+    res_x       - pixels/unit physical resolution
+                  in x direction
+    res_y       - pixels/unit physical resolution
+                  in y direction
+    unit_type   - PNG_RESOLUTION_UNKNOWN,
+                  PNG_RESOLUTION_METER
+    png_set_sCAL(png_ptr, info_ptr, unit, width, height)
+    unit        - physical scale units (an integer)
+    width       - width of a pixel in physical scale units
+    height      - height of a pixel in physical scale units
+                  (width and height are doubles)
+    png_set_sCAL_s(png_ptr, info_ptr, unit, width, height)
+    unit        - physical scale units (an integer)
+    width       - width of a pixel in physical scale units
+                  expressed as a string
+    height      - height of a pixel in physical scale units
+                 (width and height are strings like "2.54")
+    png_set_unknown_chunks(png_ptr, info_ptr, &unknowns,
+       num_unknowns)
+    unknowns          - array of png_unknown_chunk
+                        structures holding unknown chunks
+    unknowns[i].name  - name of unknown chunk
+    unknowns[i].data  - data of unknown chunk
+    unknowns[i].size  - size of unknown chunk's data
+    unknowns[i].location - position to write chunk in file
+                           0: do not write chunk
+                           PNG_HAVE_IHDR: before PLTE
+                           PNG_HAVE_PLTE: before IDAT
+                           PNG_AFTER_IDAT: after IDAT
+The "location" member is set automatically according to
+what part of the output file has already been written.
+You can change its value after calling png_set_unknown_chunks()
+as demonstrated in pngtest.c.  Within each of the "locations",
+the chunks are sequenced according to their position in the
+structure (that is, the value of "i", which is the order in which
+the chunk was either read from the input file or defined with
+png_set_unknown_chunks).
+A quick word about text and num_text.  text is an array of png_text
+structures.  num_text is the number of valid structures in the array.
+Each png_text structure holds a language code, a keyword, a text value,
+and a compression type.
+The compression types have the same valid numbers as the compression
+types of the image data.  Currently, the only valid number is zero.
+However, you can store text either compressed or uncompressed, unlike
+images, which always have to be compressed.  So if you don't want the
+text compressed, set the compression type to PNG_TEXT_COMPRESSION_NONE.
+Because tEXt and zTXt chunks don't have a language field, if you
+specify PNG_TEXT_COMPRESSION_NONE or PNG_TEXT_COMPRESSION_zTXt
+any language code or translated keyword will not be written out.
+Until text gets around a few hundred bytes, it is not worth compressing it.
+After the text has been written out to the file, the compression type
+is set to PNG_TEXT_COMPRESSION_NONE_WR or PNG_TEXT_COMPRESSION_zTXt_WR,
+so that it isn't written out again at the end (in case you are calling
+png_write_end() with the same struct).
+The keywords that are given in the PNG Specification are:
+    Title            Short (one line) title or
+                     caption for image
+    Author           Name of image's creator
+    Description      Description of image (possibly long)
+    Copyright        Copyright notice
+    Creation Time    Time of original image creation
+                     (usually RFC 1123 format, see below)
+    Software         Software used to create the image
+    Disclaimer       Legal disclaimer
+    Warning          Warning of nature of content
+    Source           Device used to create the image
+    Comment          Miscellaneous comment; conversion
+                     from other image format
+The keyword-text pairs work like this.  Keywords should be short
+simple descriptions of what the comment is about.  Some typical
+keywords are found in the PNG specification, as is some recommendations
+on keywords.  You can repeat keywords in a file.  You can even write
+some text before the image and some after.  For example, you may want
+to put a description of the image before the image, but leave the
+disclaimer until after, so viewers working over modem connections
+don't have to wait for the disclaimer to go over the modem before
+they start seeing the image.  Finally, keywords should be full
+words, not abbreviations.  Keywords and text are in the ISO 8859-1
+(Latin-1) character set (a superset of regular ASCII) and can not
+contain NUL characters, and should not contain control or other
+unprintable characters.  To make the comments widely readable, stick
+with basic ASCII, and avoid machine specific character set extensions
+like the IBM-PC character set.  The keyword must be present, but
+you can leave off the text string on non-compressed pairs.
+Compressed pairs must have a text string, as only the text string
+is compressed anyway, so the compression would be meaningless.
+PNG supports modification time via the png_time structure.  Two
+conversion routines are provided, png_convert_from_time_t() for
+time_t and png_convert_from_struct_tm() for struct tm.  The
+time_t routine uses gmtime().  You don't have to use either of
+these, but if you wish to fill in the png_time structure directly,
+you should provide the time in universal time (GMT) if possible
+instead of your local time.  Note that the year number is the full
+year (e.g. 1998, rather than 98 - PNG is year 2000 compliant!), and
+that months start with 1.
+If you want to store the time of the original image creation, you should
+use a plain tEXt chunk with the "Creation Time" keyword.  This is
+necessary because the "creation time" of a PNG image is somewhat vague,
+depending on whether you mean the PNG file, the time the image was
+created in a non-PNG format, a still photo from which the image was
+scanned, or possibly the subject matter itself.  In order to facilitate
+machine-readable dates, it is recommended that the "Creation Time"
+tEXt chunk use RFC 1123 format dates (e.g. "22 May 1997 18:07:10 GMT"),
+although this isn't a requirement.  Unlike the tIME chunk, the
+"Creation Time" tEXt chunk is not expected to be automatically changed
+by the software.  To facilitate the use of RFC 1123 dates, a function
+png_convert_to_rfc1123(png_timep) is provided to convert from PNG
+time to an RFC 1123 format string.
+Writing unknown chunks
+You can use the png_set_unknown_chunks function to queue up chunks
+for writing.  You give it a chunk name, raw data, and a size; that's
+all there is to it.  The chunks will be written by the next following
+png_write_info_before_PLTE, png_write_info, or png_write_end function.
+Any chunks previously read into the info structure's unknown-chunk
+list will also be written out in a sequence that satisfies the PNG
+specification's ordering rules.
+The high-level write interface
+At this point there are two ways to proceed; through the high-level
+write interface, or through a sequence of low-level write operations.
+You can use the high-level interface if your image data is present
+in the info structure.  All defined output
+transformations are permitted, enabled by the following masks.
+    PNG_TRANSFORM_IDENTITY      No transformation
+    PNG_TRANSFORM_PACKING       Pack 1, 2 and 4-bit samples
+    PNG_TRANSFORM_PACKSWAP      Change order of packed
+                                pixels to LSB first
+    PNG_TRANSFORM_INVERT_MONO   Invert monochrome images
+    PNG_TRANSFORM_SHIFT         Normalize pixels to the
+                                sBIT depth
+    PNG_TRANSFORM_BGR           Flip RGB to BGR, RGBA
+                                to BGRA
+    PNG_TRANSFORM_SWAP_ALPHA    Flip RGBA to ARGB or GA
+                                to AG
+    PNG_TRANSFORM_INVERT_ALPHA  Change alpha from opacity
+                                to transparency
+    PNG_TRANSFORM_SWAP_ENDIAN   Byte-swap 16-bit samples
+    PNG_TRANSFORM_STRIP_FILLER        Strip out filler
+                                      bytes (deprecated).
+    PNG_TRANSFORM_STRIP_FILLER_BEFORE Strip out leading
+                                      filler bytes
+    PNG_TRANSFORM_STRIP_FILLER_AFTER  Strip out trailing
+                                      filler bytes
+If you have valid image data in the info structure (you can use
+png_set_rows() to put image data in the info structure), simply do this:
+    png_write_png(png_ptr, info_ptr, png_transforms, NULL)
+where png_transforms is an integer containing the bitwise OR of some set of
+transformation flags.  This call is equivalent to png_write_info(),
+followed the set of transformations indicated by the transform mask,
+then png_write_image(), and finally png_write_end().
+(The final parameter of this call is not yet used.  Someday it might point
+to transformation parameters required by some future output transform.)
+You must use png_transforms and not call any png_set_transform() functions
+when you use png_write_png().
+The low-level write interface
+If you are going the low-level route instead, you are now ready to
+write all the file information up to the actual image data.  You do
+this with a call to png_write_info().
+    png_write_info(png_ptr, info_ptr);
+Note that there is one transformation you may need to do before
+png_write_info().  In PNG files, the alpha channel in an image is the
+level of opacity.  If your data is supplied as a level of transparency,
+you can invert the alpha channel before you write it, so that 0 is
+fully transparent and 255 (in 8-bit or paletted images) or 65535
+(in 16-bit images) is fully opaque, with
+    png_set_invert_alpha(png_ptr);
+This must appear before png_write_info() instead of later with the
+other transformations because in the case of paletted images the tRNS
+chunk data has to be inverted before the tRNS chunk is written.  If
+your image is not a paletted image, the tRNS data (which in such cases
+represents a single color to be rendered as transparent) won't need to
+be changed, and you can safely do this transformation after your
+png_write_info() call.
+If you need to write a private chunk that you want to appear before
+the PLTE chunk when PLTE is present, you can write the PNG info in
+two steps, and insert code to write your own chunk between them:
+    png_write_info_before_PLTE(png_ptr, info_ptr);
+    png_set_unknown_chunks(png_ptr, info_ptr, ...);
+    png_write_info(png_ptr, info_ptr);
+After you've written the file information, you can set up the library
+to handle any special transformations of the image data.  The various
+ways to transform the data will be described in the order that they
+should occur.  This is important, as some of these change the color
+type and/or bit depth of the data, and some others only work on
+certain color types and bit depths.  Even though each transformation
+checks to see if it has data that it can do something with, you should
+make sure to only enable a transformation if it will be valid for the
+data.  For example, don't swap red and blue on grayscale data.
+PNG files store RGB pixels packed into 3 or 6 bytes.  This code tells
+the library to strip input data that has 4 or 8 bytes per pixel down
+to 3 or 6 bytes (or strip 2 or 4-byte grayscale+filler data to 1 or 2
+bytes per pixel).
+    png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE);
+where the 0 is unused, and the location is either PNG_FILLER_BEFORE or
+PNG_FILLER_AFTER, depending upon whether the filler byte in the pixel
+is stored XRGB or RGBX.
+PNG files pack pixels of bit depths 1, 2, and 4 into bytes as small as
+they can, resulting in, for example, 8 pixels per byte for 1 bit files.
+If the data is supplied at 1 pixel per byte, use this code, which will
+correctly pack the pixels into a single byte:
+    png_set_packing(png_ptr);
+PNG files reduce possible bit depths to 1, 2, 4, 8, and 16.  If your
+data is of another bit depth, you can write an sBIT chunk into the
+file so that decoders can recover the original data if desired.
+    /* Set the true bit depth of the image data */
+    if (color_type & PNG_COLOR_MASK_COLOR)
+    {
+       sig_bit.red = true_bit_depth;
+       sig_bit.green = true_bit_depth;
+       sig_bit.blue = true_bit_depth;
+    }
+    else
+    {
+       sig_bit.gray = true_bit_depth;
+    }
+    if (color_type & PNG_COLOR_MASK_ALPHA)
+    {
+       sig_bit.alpha = true_bit_depth;
+    }
+    png_set_sBIT(png_ptr, info_ptr, &sig_bit);
+If the data is stored in the row buffer in a bit depth other than
+one supported by PNG (e.g. 3 bit data in the range 0-7 for a 4-bit PNG),
+this will scale the values to appear to be the correct bit depth as
+is required by PNG.
+    png_set_shift(png_ptr, &sig_bit);
+PNG files store 16-bit pixels in network byte order (big-endian,
+ie. most significant bits first).  This code would be used if they are
+supplied the other way (little-endian, i.e. least significant bits
+first, the way PCs store them):
+    if (bit_depth > 8)
+       png_set_swap(png_ptr);
+If you are using packed-pixel images (1, 2, or 4 bits/pixel), and you
+need to change the order the pixels are packed into bytes, you can use:
+    if (bit_depth < 8)
+       png_set_packswap(png_ptr);
+PNG files store 3 color pixels in red, green, blue order.  This code
+would be used if they are supplied as blue, green, red:
+    png_set_bgr(png_ptr);
+PNG files describe monochrome as black being zero and white being
+one. This code would be used if the pixels are supplied with this reversed
+(black being one and white being zero):
+    png_set_invert_mono(png_ptr);
+Finally, you can write your own transformation function if none of
+the existing ones meets your needs.  This is done by setting a callback
+with
+    png_set_write_user_transform_fn(png_ptr,
+       write_transform_fn);
+You must supply the function
+    void write_transform_fn(png_structp png_ptr, png_row_infop
+       row_info, png_bytep data)
+See pngtest.c for a working example.  Your function will be called
+before any of the other transformations are processed.  If supported
+libpng also supplies an information routine that may be called from
+your callback:
+   png_get_current_row_number(png_ptr);
+   png_get_current_pass_number(png_ptr);
+This returns the current row passed to the transform.  With interlaced
+images the value returned is the row in the input sub-image image.  Use
+PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
+find the output pixel (x,y) given an interlaced sub-image pixel (row,col,pass).
+The discussion of interlace handling above contains more information on how to
+use these values.
+You can also set up a pointer to a user structure for use by your
+callback function.
+    png_set_user_transform_info(png_ptr, user_ptr, 0, 0);
+The user_channels and user_depth parameters of this function are ignored
+when writing; you can set them to zero as shown.
+You can retrieve the pointer via the function png_get_user_transform_ptr().
+For example:
+    voidp write_user_transform_ptr =
+       png_get_user_transform_ptr(png_ptr);
+It is possible to have libpng flush any pending output, either manually,
+or automatically after a certain number of lines have been written.  To
+flush the output stream a single time call:
+    png_write_flush(png_ptr);
+and to have libpng flush the output stream periodically after a certain
+number of scanlines have been written, call:
+    png_set_flush(png_ptr, nrows);
+Note that the distance between rows is from the last time png_write_flush()
+was called, or the first row of the image if it has never been called.
+So if you write 50 lines, and then png_set_flush 25, it will flush the
+output on the next scanline, and every 25 lines thereafter, unless
+png_write_flush() is called before 25 more lines have been written.
+If nrows is too small (less than about 10 lines for a 640 pixel wide
+RGB image) the image compression may decrease noticeably (although this
+may be acceptable for real-time applications).  Infrequent flushing will
+only degrade the compression performance by a few percent over images
+that do not use flushing.
+Writing the image data
+That's it for the transformations.  Now you can write the image data.
+The simplest way to do this is in one function call.  If you have the
+whole image in memory, you can just call png_write_image() and libpng
+will write the image.  You will need to pass in an array of pointers to
+each row.  This function automatically handles interlacing, so you don't
+need to call png_set_interlace_handling() or call this function multiple
+times, or any of that other stuff necessary with png_write_rows().
+    png_write_image(png_ptr, row_pointers);
+where row_pointers is:
+    png_byte *row_pointers[height];
+You can point to void or char or whatever you use for pixels.
+If you don't want to write the whole image at once, you can
+use png_write_rows() instead.  If the file is not interlaced,
+this is simple:
+    png_write_rows(png_ptr, row_pointers,
+       number_of_rows);
+row_pointers is the same as in the png_write_image() call.
+If you are just writing one row at a time, you can do this with
+a single row_pointer instead of an array of row_pointers:
+    png_bytep row_pointer = row;
+    png_write_row(png_ptr, row_pointer);
+When the file is interlaced, things can get a good deal more complicated.
+The only currently (as of the PNG Specification version 1.2, dated July
+1999) defined interlacing scheme for PNG files is the "Adam7" interlace
+scheme, that breaks down an image into seven smaller images of varying
+size.  libpng will build these images for you, or you can do them
+yourself.  If you want to build them yourself, see the PNG specification
+for details of which pixels to write when.
+If you don't want libpng to handle the interlacing details, just
+use png_set_interlace_handling() and call png_write_rows() the
+correct number of times to write all the sub-images
+(png_set_interlace_handling() returns the number of sub-images.)
+If you want libpng to build the sub-images, call this before you start
+writing any rows:
+    number_of_passes = png_set_interlace_handling(png_ptr);
+This will return the number of passes needed.  Currently, this is seven,
+but may change if another interlace type is added.
+Then write the complete image number_of_passes times.
+    png_write_rows(png_ptr, row_pointers, number_of_rows);
+Think carefully before you write an interlaced image.  Typically code that
+reads such images reads all the image data into memory, uncompressed, before
+doing any processing.  Only code that can display an image on the fly can
+take advantage of the interlacing and even then the image has to be exactly
+the correct size for the output device, because scaling an image requires
+adjacent pixels and these are not available until all the passes have been
+read.
+If you do write an interlaced image you will hardly ever need to handle
+the interlacing yourself.  Call png_set_interlace_handling() and use the
+approach described above.
+The only time it is conceivable that you will really need to write an
+interlaced image pass-by-pass is when you have read one pass by pass and
+made some pixel-by-pixel transformation to it, as described in the read
+code above.  In this case use the PNG_PASS_ROWS and PNG_PASS_COLS macros
+to determine the size of each sub-image in turn and simply write the rows
+you obtained from the read code.
+Finishing a sequential write
+After you are finished writing the image, you should finish writing
+the file.  If you are interested in writing comments or time, you should
+pass an appropriately filled png_info pointer.  If you are not interested,
+you can pass NULL.
+    png_write_end(png_ptr, info_ptr);
+When you are done, you can free all memory used by libpng like this:
+    png_destroy_write_struct(&png_ptr, &info_ptr);
+It is also possible to individually free the info_ptr members that
+point to libpng-allocated storage with the following function:
+    png_free_data(png_ptr, info_ptr, mask, seq)
+    mask  - identifies data to be freed, a mask
+            containing the bitwise OR of one or
+            more of
+              PNG_FREE_PLTE, PNG_FREE_TRNS,
+              PNG_FREE_HIST, PNG_FREE_ICCP,
+              PNG_FREE_PCAL, PNG_FREE_ROWS,
+              PNG_FREE_SCAL, PNG_FREE_SPLT,
+              PNG_FREE_TEXT, PNG_FREE_UNKN,
+            or simply PNG_FREE_ALL
+    seq   - sequence number of item to be freed
+            (-1 for all items)
+This function may be safely called when the relevant storage has
+already been freed, or has not yet been allocated, or was allocated
+by the user  and not by libpng,  and will in those cases do nothing.
+The "seq" parameter is ignored if only one item of the selected data
+type, such as PLTE, is allowed.  If "seq" is not -1, and multiple items
+are allowed for the data type identified in the mask, such as text or
+sPLT, only the n'th item in the structure is freed, where n is "seq".
+If you allocated data such as a palette that you passed in to libpng
+with png_set_*, you must not free it until just before the call to
+png_destroy_write_struct().
+The default behavior is only to free data that was allocated internally
+by libpng.  This can be changed, so that libpng will not free the data,
+or so that it will free data that was allocated by the user with png_malloc()
+or png_zalloc() and passed in via a png_set_*() function, with
+    png_data_freer(png_ptr, info_ptr, freer, mask)
+    freer  - one of
+               PNG_DESTROY_WILL_FREE_DATA
+               PNG_SET_WILL_FREE_DATA
+               PNG_USER_WILL_FREE_DATA
+    mask   - which data elements are affected
+             same choices as in png_free_data()
+For example, to transfer responsibility for some data from a read structure
+to a write structure, you could use
+    png_data_freer(read_ptr, read_info_ptr,
+       PNG_USER_WILL_FREE_DATA,
+       PNG_FREE_PLTE|PNG_FREE_tRNS|PNG_FREE_hIST)
+    png_data_freer(write_ptr, write_info_ptr,
+       PNG_DESTROY_WILL_FREE_DATA,
+       PNG_FREE_PLTE|PNG_FREE_tRNS|PNG_FREE_hIST)
+thereby briefly reassigning responsibility for freeing to the user but
+immediately afterwards reassigning it once more to the write_destroy
+function.  Having done this, it would then be safe to destroy the read
+structure and continue to use the PLTE, tRNS, and hIST data in the write
+structure.
+This function only affects data that has already been allocated.
+You can call this function before calling after the png_set_*() functions
+to control whether the user or png_destroy_*() is supposed to free the data.
+When the user assumes responsibility for libpng-allocated data, the
+application must use
+png_free() to free it, and when the user transfers responsibility to libpng
+for data that the user has allocated, the user must have used png_malloc()
+or png_zalloc() to allocate it.
+If you allocated text_ptr.text, text_ptr.lang, and text_ptr.translated_keyword
+separately, do not transfer responsibility for freeing text_ptr to libpng,
+because when libpng fills a png_text structure it combines these members with
+the key member, and png_free_data() will free only text_ptr.key.  Similarly,
+if you transfer responsibility for free'ing text_ptr from libpng to your
+application, your application must not separately free those members.
+For a more compact example of writing a PNG image, see the file example.c.
+V. Modifying/Customizing libpng:
+There are two issues here.  The first is changing how libpng does
+standard things like memory allocation, input/output, and error handling.
+The second deals with more complicated things like adding new chunks,
+adding new transformations, and generally changing how libpng works.
+Both of those are compile-time issues; that is, they are generally
+determined at the time the code is written, and there is rarely a need
+to provide the user with a means of changing them.
+Memory allocation, input/output, and error handling
+All of the memory allocation, input/output, and error handling in libpng
+goes through callbacks that are user-settable.  The default routines are
+in pngmem.c, pngrio.c, pngwio.c, and pngerror.c, respectively.  To change
+these functions, call the appropriate png_set_*_fn() function.
+Memory allocation is done through the functions png_malloc(), png_calloc(),
+and png_free().  These currently just call the standard C functions.
+png_calloc() calls png_malloc() and then clears the newly
+allocated memory to zero.  There is limited support for certain systems
+with segmented memory architectures and the types of pointers declared by
+png.h match this; you will have to use appropriate pointers in your
+application.  Since it is
+unlikely that the method of handling memory allocation on a platform
+will change between applications, these functions must be modified in
+the library at compile time.  If you prefer to use a different method
+of allocating and freeing data, you can use png_create_read_struct_2() or
+png_create_write_struct_2() to register your own functions as described
+above.  These functions also provide a void pointer that can be retrieved
+via
+    mem_ptr=png_get_mem_ptr(png_ptr);
+Your replacement memory functions must have prototypes as follows:
+    png_voidp malloc_fn(png_structp png_ptr,
+       png_alloc_size_t size);
+    void free_fn(png_structp png_ptr, png_voidp ptr);
+Your malloc_fn() must return NULL in case of failure.  The png_malloc()
+function will normally call png_error() if it receives a NULL from the
+system memory allocator or from your replacement malloc_fn().
+Your free_fn() will never be called with a NULL ptr, since libpng's
+png_free() checks for NULL before calling free_fn().
+Input/Output in libpng is done through png_read() and png_write(),
+which currently just call fread() and fwrite().  The FILE * is stored in
+png_struct and is initialized via png_init_io().  If you wish to change
+the method of I/O, the library supplies callbacks that you can set
+through the function png_set_read_fn() and png_set_write_fn() at run
+time, instead of calling the png_init_io() function.  These functions
+also provide a void pointer that can be retrieved via the function
+png_get_io_ptr().  For example:
+    png_set_read_fn(png_structp read_ptr,
+        voidp read_io_ptr, png_rw_ptr read_data_fn)
+    png_set_write_fn(png_structp write_ptr,
+        voidp write_io_ptr, png_rw_ptr write_data_fn,
+        png_flush_ptr output_flush_fn);
+    voidp read_io_ptr = png_get_io_ptr(read_ptr);
+    voidp write_io_ptr = png_get_io_ptr(write_ptr);
+The replacement I/O functions must have prototypes as follows:
+    void user_read_data(png_structp png_ptr,
+        png_bytep data, png_size_t length);
+    void user_write_data(png_structp png_ptr,
+        png_bytep data, png_size_t length);
+    void user_flush_data(png_structp png_ptr);
+The user_read_data() function is responsible for detecting and
+handling end-of-data errors.
+Supplying NULL for the read, write, or flush functions sets them back
+to using the default C stream functions, which expect the io_ptr to
+point to a standard *FILE structure.  It is probably a mistake
+to use NULL for one of write_data_fn and output_flush_fn but not both
+of them, unless you have built libpng with PNG_NO_WRITE_FLUSH defined.
+It is an error to read from a write stream, and vice versa.
+Error handling in libpng is done through png_error() and png_warning().
+Errors handled through png_error() are fatal, meaning that png_error()
+should never return to its caller.  Currently, this is handled via
+setjmp() and longjmp() (unless you have compiled libpng with
+PNG_NO_SETJMP, in which case it is handled via PNG_ABORT()),
+but you could change this to do things like exit() if you should wish,
+as long as your function does not return.
+On non-fatal errors, png_warning() is called
+to print a warning message, and then control returns to the calling code.
+By default png_error() and png_warning() print a message on stderr via
+fprintf() unless the library is compiled with PNG_NO_CONSOLE_IO defined
+(because you don't want the messages) or PNG_NO_STDIO defined (because
+fprintf() isn't available).  If you wish to change the behavior of the error
+functions, you will need to set up your own message callbacks.  These
+functions are normally supplied at the time that the png_struct is created.
+It is also possible to redirect errors and warnings to your own replacement
+functions after png_create_*_struct() has been called by calling:
+    png_set_error_fn(png_structp png_ptr,
+        png_voidp error_ptr, png_error_ptr error_fn,
+        png_error_ptr warning_fn);
+    png_voidp error_ptr = png_get_error_ptr(png_ptr);
+If NULL is supplied for either error_fn or warning_fn, then the libpng
+default function will be used, calling fprintf() and/or longjmp() if a
+problem is encountered.  The replacement error functions should have
+parameters as follows:
+    void user_error_fn(png_structp png_ptr,
+        png_const_charp error_msg);
+    void user_warning_fn(png_structp png_ptr,
+        png_const_charp warning_msg);
+The motivation behind using setjmp() and longjmp() is the C++ throw and
+catch exception handling methods.  This makes the code much easier to write,
+as there is no need to check every return code of every function call.
+However, there are some uncertainties about the status of local variables
+after a longjmp, so the user may want to be careful about doing anything
+after setjmp returns non-zero besides returning itself.  Consult your
+compiler documentation for more details.  For an alternative approach, you
+may wish to use the "cexcept" facility (see http://cexcept.sourceforge.net),
+which is illustrated in pngvalid.c and in contrib/visupng.
+Custom chunks
+If you need to read or write custom chunks, you may need to get deeper
+into the libpng code.  The library now has mechanisms for storing
+and writing chunks of unknown type; you can even declare callbacks
+for custom chunks.  However, this may not be good enough if the
+library code itself needs to know about interactions between your
+chunk and existing `intrinsic' chunks.
+If you need to write a new intrinsic chunk, first read the PNG
+specification. Acquire a first level of understanding of how it works.
+Pay particular attention to the sections that describe chunk names,
+and look at how other chunks were designed, so you can do things
+similarly.  Second, check out the sections of libpng that read and
+write chunks.  Try to find a chunk that is similar to yours and use
+it as a template.  More details can be found in the comments inside
+the code.  It is best to handle private or unknown chunks in a generic method,
+via callback functions, instead of by modifying libpng functions. This
+is illustrated in pngtest.c, which uses a callback function to handle a
+private "vpAg" chunk and the new "sTER" chunk, which are both unknown to
+libpng.
+If you wish to write your own transformation for the data, look through
+the part of the code that does the transformations, and check out some of
+the simpler ones to get an idea of how they work.  Try to find a similar
+transformation to the one you want to add and copy off of it.  More details
+can be found in the comments inside the code itself.
+Configuring for 16-bit platforms
+You will want to look into zconf.h to tell zlib (and thus libpng) that
+it cannot allocate more then 64K at a time.  Even if you can, the memory
+won't be accessible.  So limit zlib and libpng to 64K by defining MAXSEG_64K.
+Configuring for DOS
+For DOS users who only have access to the lower 640K, you will
+have to limit zlib's memory usage via a png_set_compression_mem_level()
+call.  See zlib.h or zconf.h in the zlib library for more information.
+Configuring for Medium Model
+Libpng's support for medium model has been tested on most of the popular
+compilers.  Make sure MAXSEG_64K gets defined, USE_FAR_KEYWORD gets
+defined, and FAR gets defined to far in pngconf.h, and you should be
+all set.  Everything in the library (except for zlib's structure) is
+expecting far data.  You must use the typedefs with the p or pp on
+the end for pointers (or at least look at them and be careful).  Make
+note that the rows of data are defined as png_bytepp, which is
+an "unsigned char far * far *".
+Configuring for gui/windowing platforms:
+You will need to write new error and warning functions that use the GUI
+interface, as described previously, and set them to be the error and
+warning functions at the time that png_create_*_struct() is called,
+in order to have them available during the structure initialization.
+They can be changed later via png_set_error_fn().  On some compilers,
+you may also have to change the memory allocators (png_malloc, etc.).
+Configuring for compiler xxx:
+All includes for libpng are in pngconf.h.  If you need to add, change
+or delete an include, this is the place to do it.
+The includes that are not needed outside libpng are placed in pngpriv.h,
+which is only used by the routines inside libpng itself.
+The files in libpng proper only include pngpriv.h and png.h, which
+in turn includes pngconf.h and, as of libpng-1.5.0, pnglibconf.h.
+As of libpng-1.5.0, pngpriv.h also includes three other private header
+files, pngstruct.h, pnginfo.h, and pngdebug.h, which contain material
+that previously appeared in the public headers.
+Configuring zlib:
+There are special functions to configure the compression.  Perhaps the
+most useful one changes the compression level, which currently uses
+input compression values in the range 0 - 9.  The library normally
+uses the default compression level (Z_DEFAULT_COMPRESSION = 6).  Tests
+have shown that for a large majority of images, compression values in
+the range 3-6 compress nearly as well as higher levels, and do so much
+faster.  For online applications it may be desirable to have maximum speed
+(Z_BEST_SPEED = 1).  With versions of zlib after v0.99, you can also
+specify no compression (Z_NO_COMPRESSION = 0), but this would create
+files larger than just storing the raw bitmap.  You can specify the
+compression level by calling:
+    #include zlib.h
+    png_set_compression_level(png_ptr, level);
+Another useful one is to reduce the memory level used by the library.
+The memory level defaults to 8, but it can be lowered if you are
+short on memory (running DOS, for example, where you only have 640K).
+Note that the memory level does have an effect on compression; among
+other things, lower levels will result in sections of incompressible
+data being emitted in smaller stored blocks, with a correspondingly
+larger relative overhead of up to 15% in the worst case.
+    #include zlib.h
+    png_set_compression_mem_level(png_ptr, level);
+The other functions are for configuring zlib.  They are not recommended
+for normal use and may result in writing an invalid PNG file.  See
+zlib.h for more information on what these mean.
+    #include zlib.h
+    png_set_compression_strategy(png_ptr,
+        strategy);
+    png_set_compression_window_bits(png_ptr,
+        window_bits);
+    png_set_compression_method(png_ptr, method);
+    png_set_compression_buffer_size(png_ptr, size);
+As of libpng version 1.5.4, additional APIs became
+available to set these separately for non-IDAT
+compressed chunks such as zTXt, iTXt, and iCCP:
+    #include zlib.h
+    #if PNG_LIBPNG_VER <= 10504
+    png_set_text_compression_level(png_ptr, level);
+    png_set_text_compression_mem_level(png_ptr, level);
+    png_set_text_compression_strategy(png_ptr,
+        strategy);
+    png_set_text_compression_window_bits(png_ptr,
+        window_bits);
+    png_set_text_compression_method(png_ptr, method);
+    #endif
+Controlling row filtering
+If you want to control whether libpng uses filtering or not, which
+filters are used, and how it goes about picking row filters, you
+can call one of these functions.  The selection and configuration
+of row filters can have a significant impact on the size and
+encoding speed and a somewhat lesser impact on the decoding speed
+of an image.  Filtering is enabled by default for RGB and grayscale
+images (with and without alpha), but not for paletted images nor
+for any images with bit depths less than 8 bits/pixel.
+The 'method' parameter sets the main filtering method, which is
+currently only '0' in the PNG 1.2 specification.  The 'filters'
+parameter sets which filter(s), if any, should be used for each
+scanline.  Possible values are PNG_ALL_FILTERS and PNG_NO_FILTERS
+to turn filtering on and off, respectively.
+Individual filter types are PNG_FILTER_NONE, PNG_FILTER_SUB,
+PNG_FILTER_UP, PNG_FILTER_AVG, PNG_FILTER_PAETH, which can be bitwise
+ORed together with '|' to specify one or more filters to use.
+These filters are described in more detail in the PNG specification.
+If you intend to change the filter type during the course of writing
+the image, you should start with flags set for all of the filters
+you intend to use so that libpng can initialize its internal
+structures appropriately for all of the filter types.  (Note that this
+means the first row must always be adaptively filtered, because libpng
+currently does not allocate the filter buffers until png_write_row()
+is called for the first time.)
+    filters = PNG_FILTER_NONE | PNG_FILTER_SUB
+              PNG_FILTER_UP | PNG_FILTER_AVG |
+              PNG_FILTER_PAETH | PNG_ALL_FILTERS;
+    png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE,
+       filters);
+              The second parameter can also be
+              PNG_INTRAPIXEL_DIFFERENCING if you are
+              writing a PNG to be embedded in a MNG
+              datastream.  This parameter must be the
+              same as the value of filter_method used
+              in png_set_IHDR().
+It is also possible to influence how libpng chooses from among the
+available filters.  This is done in one or both of two ways - by
+telling it how important it is to keep the same filter for successive
+rows, and by telling it the relative computational costs of the filters.
+    double weights[3] = {1.5, 1.3, 1.1},
+       costs[PNG_FILTER_VALUE_LAST] =
+       {1.0, 1.3, 1.3, 1.5, 1.7};
+    png_set_filter_heuristics(png_ptr,
+       PNG_FILTER_HEURISTIC_WEIGHTED, 3,
+       weights, costs);
+The weights are multiplying factors that indicate to libpng that the
+row filter should be the same for successive rows unless another row filter
+is that many times better than the previous filter.  In the above example,
+if the previous 3 filters were SUB, SUB, NONE, the SUB filter could have a
+"sum of absolute differences" 1.5 x 1.3 times higher than other filters
+and still be chosen, while the NONE filter could have a sum 1.1 times
+higher than other filters and still be chosen.  Unspecified weights are
+taken to be 1.0, and the specified weights should probably be declining
+like those above in order to emphasize recent filters over older filters.
+The filter costs specify for each filter type a relative decoding cost
+to be considered when selecting row filters.  This means that filters
+with higher costs are less likely to be chosen over filters with lower
+costs, unless their "sum of absolute differences" is that much smaller.
+The costs do not necessarily reflect the exact computational speeds of
+the various filters, since this would unduly influence the final image
+size.
+Note that the numbers above were invented purely for this example and
+are given only to help explain the function usage.  Little testing has
+been done to find optimum values for either the costs or the weights.
+Removing unwanted object code
+There are a bunch of #define's in pngconf.h that control what parts of
+libpng are compiled.  All the defines end in _SUPPORTED.  If you are
+never going to use a capability, you can change the #define to #undef
+before recompiling libpng and save yourself code and data space, or
+you can turn off individual capabilities with defines that begin with
+PNG_NO_.
+In libpng-1.5.0 and later, the #define's are in pnglibconf.h instead.
+You can also turn all of the transforms and ancillary chunk capabilities
+off en masse with compiler directives that define
+PNG_NO_READ[or WRITE]_TRANSFORMS, or PNG_NO_READ[or WRITE]_ANCILLARY_CHUNKS,
+or all four,
+along with directives to turn on any of the capabilities that you do
+want.  The PNG_NO_READ[or WRITE]_TRANSFORMS directives disable the extra
+transformations but still leave the library fully capable of reading
+and writing PNG files with all known public chunks. Use of the
+PNG_NO_READ[or WRITE]_ANCILLARY_CHUNKS directive produces a library
+that is incapable of reading or writing ancillary chunks.  If you are
+not using the progressive reading capability, you can turn that off
+with PNG_NO_PROGRESSIVE_READ (don't confuse this with the INTERLACING
+capability, which you'll still have).
+All the reading and writing specific code are in separate files, so the
+linker should only grab the files it needs.  However, if you want to
+make sure, or if you are building a stand alone library, all the
+reading files start with "pngr" and all the writing files start with "pngw".
+The files that don't match either (like png.c, pngtrans.c, etc.)
+are used for both reading and writing, and always need to be included.
+The progressive reader is in pngpread.c
+If you are creating or distributing a dynamically linked library (a .so
+or DLL file), you should not remove or disable any parts of the library,
+as this will cause applications linked with different versions of the
+library to fail if they call functions not available in your library.
+The size of the library itself should not be an issue, because only
+those sections that are actually used will be loaded into memory.
+Requesting debug printout
+The macro definition PNG_DEBUG can be used to request debugging
+printout.  Set it to an integer value in the range 0 to 3.  Higher
+numbers result in increasing amounts of debugging information.  The
+information is printed to the "stderr" file, unless another file
+name is specified in the PNG_DEBUG_FILE macro definition.
+When PNG_DEBUG > 0, the following functions (macros) become available:
+   png_debug(level, message)
+   png_debug1(level, message, p1)
+   png_debug2(level, message, p1, p2)
+in which "level" is compared to PNG_DEBUG to decide whether to print
+the message, "message" is the formatted string to be printed,
+and p1 and p2 are parameters that are to be embedded in the string
+according to printf-style formatting directives.  For example,
+   png_debug1(2, "foo=%d\n", foo);
+is expanded to
+   if (PNG_DEBUG > 2)
+      fprintf(PNG_DEBUG_FILE, "foo=%d\n", foo);
+When PNG_DEBUG is defined but is zero, the macros aren't defined, but you
+can still use PNG_DEBUG to control your own debugging:
+   #ifdef PNG_DEBUG
+       fprintf(stderr, ...
+   #endif
+When PNG_DEBUG = 1, the macros are defined, but only png_debug statements
+having level = 0 will be printed.  There aren't any such statements in
+this version of libpng, but if you insert some they will be printed.
+VI.  MNG support
+The MNG specification (available at http://www.libpng.org/pub/mng) allows
+certain extensions to PNG for PNG images that are embedded in MNG datastreams.
+Libpng can support some of these extensions.  To enable them, use the
+png_permit_mng_features() function:
+   feature_set = png_permit_mng_features(png_ptr, mask)
+   mask is a png_uint_32 containing the bitwise OR of the
+        features you want to enable.  These include
+        PNG_FLAG_MNG_EMPTY_PLTE
+        PNG_FLAG_MNG_FILTER_64
+        PNG_ALL_MNG_FEATURES
+   feature_set is a png_uint_32 that is the bitwise AND of
+      your mask with the set of MNG features that is
+      supported by the version of libpng that you are using.
+It is an error to use this function when reading or writing a standalone
+PNG file with the PNG 8-byte signature.  The PNG datastream must be wrapped
+in a MNG datastream.  As a minimum, it must have the MNG 8-byte signature
+and the MHDR and MEND chunks.  Libpng does not provide support for these
+or any other MNG chunks; your application must provide its own support for
+them.  You may wish to consider using libmng (available at
+http://www.libmng.com) instead.
+VII.  Changes to Libpng from version 0.88
+It should be noted that versions of libpng later than 0.96 are not
+distributed by the original libpng author, Guy Schalnat, nor by
+Andreas Dilger, who had taken over from Guy during 1996 and 1997, and
+distributed versions 0.89 through 0.96, but rather by another member
+of the original PNG Group, Glenn Randers-Pehrson.  Guy and Andreas are
+still alive and well, but they have moved on to other things.
+The old libpng functions png_read_init(), png_write_init(),
+png_info_init(), png_read_destroy(), and png_write_destroy() have been
+moved to PNG_INTERNAL in version 0.95 to discourage their use.  These
+functions will be removed from libpng version 1.4.0.
+The preferred method of creating and initializing the libpng structures is
+via the png_create_read_struct(), png_create_write_struct(), and
+png_create_info_struct() because they isolate the size of the structures
+from the application, allow version error checking, and also allow the
+use of custom error handling routines during the initialization, which
+the old functions do not.  The functions png_read_destroy() and
+png_write_destroy() do not actually free the memory that libpng
+allocated for these structs, but just reset the data structures, so they
+can be used instead of png_destroy_read_struct() and
+png_destroy_write_struct() if you feel there is too much system overhead
+allocating and freeing the png_struct for each image read.
+Setting the error callbacks via png_set_message_fn() before
+png_read_init() as was suggested in libpng-0.88 is no longer supported
+because this caused applications that do not use custom error functions
+to fail if the png_ptr was not initialized to zero.  It is still possible
+to set the error callbacks AFTER png_read_init(), or to change them with
+png_set_error_fn(), which is essentially the same function, but with a new
+name to force compilation errors with applications that try to use the old
+method.
+Starting with version 1.0.7, you can find out which version of the library
+you are using at run-time:
+   png_uint_32 libpng_vn = png_access_version_number();
+The number libpng_vn is constructed from the major version, minor
+version with leading zero, and release number with leading zero,
+(e.g., libpng_vn for version 1.0.7 is 10007).
+Note that this function does not take a png_ptr, so you can call it
+before you've created one.
+You can also check which version of png.h you used when compiling your
+application:
+   png_uint_32 application_vn = PNG_LIBPNG_VER;
+VIII.  Changes to Libpng from version 1.0.x to 1.2.x
+Support for user memory management was enabled by default.  To
+accomplish this, the functions png_create_read_struct_2(),
+png_create_write_struct_2(), png_set_mem_fn(), png_get_mem_ptr(),
+png_malloc_default(), and png_free_default() were added.
+Support for the iTXt chunk has been enabled by default as of
+version 1.2.41.
+Support for certain MNG features was enabled.
+Support for numbered error messages was added.  However, we never got
+around to actually numbering the error messages.  The function
+png_set_strip_error_numbers() was added (Note: the prototype for this
+function was inadvertently removed from png.h in PNG_NO_ASSEMBLER_CODE
+builds of libpng-1.2.15.  It was restored in libpng-1.2.36).
+The png_malloc_warn() function was added at libpng-1.2.3.  This issues
+a png_warning and returns NULL instead of aborting when it fails to
+acquire the requested memory allocation.
+Support for setting user limits on image width and height was enabled
+by default.  The functions png_set_user_limits(), png_get_user_width_max(),
+and png_get_user_height_max() were added at libpng-1.2.6.
+The png_set_add_alpha() function was added at libpng-1.2.7.
+The function png_set_expand_gray_1_2_4_to_8() was added at libpng-1.2.9.
+Unlike png_set_gray_1_2_4_to_8(), the new function does not expand the
+tRNS chunk to alpha. The png_set_gray_1_2_4_to_8() function is
+deprecated.
+A number of macro definitions in support of runtime selection of
+assembler code features (especially Intel MMX code support) were
+added at libpng-1.2.0:
+    PNG_ASM_FLAG_MMX_SUPPORT_COMPILED
+    PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU
+    PNG_ASM_FLAG_MMX_READ_COMBINE_ROW
+    PNG_ASM_FLAG_MMX_READ_INTERLACE
+    PNG_ASM_FLAG_MMX_READ_FILTER_SUB
+    PNG_ASM_FLAG_MMX_READ_FILTER_UP
+    PNG_ASM_FLAG_MMX_READ_FILTER_AVG
+    PNG_ASM_FLAG_MMX_READ_FILTER_PAETH
+    PNG_ASM_FLAGS_INITIALIZED
+    PNG_MMX_READ_FLAGS
+    PNG_MMX_FLAGS
+    PNG_MMX_WRITE_FLAGS
+    PNG_MMX_FLAGS
+We added the following functions in support of runtime
+selection of assembler code features:
+    png_get_mmx_flagmask()
+    png_set_mmx_thresholds()
+    png_get_asm_flags()
+    png_get_mmx_bitdepth_threshold()
+    png_get_mmx_rowbytes_threshold()
+    png_set_asm_flags()
+We replaced all of these functions with simple stubs in libpng-1.2.20,
+when the Intel assembler code was removed due to a licensing issue.
+These macros are deprecated:
+    PNG_READ_TRANSFORMS_NOT_SUPPORTED
+    PNG_PROGRESSIVE_READ_NOT_SUPPORTED
+    PNG_NO_SEQUENTIAL_READ_SUPPORTED
+    PNG_WRITE_TRANSFORMS_NOT_SUPPORTED
+    PNG_READ_ANCILLARY_CHUNKS_NOT_SUPPORTED
+    PNG_WRITE_ANCILLARY_CHUNKS_NOT_SUPPORTED
+They have been replaced, respectively, by:
+    PNG_NO_READ_TRANSFORMS
+    PNG_NO_PROGRESSIVE_READ
+    PNG_NO_SEQUENTIAL_READ
+    PNG_NO_WRITE_TRANSFORMS
+    PNG_NO_READ_ANCILLARY_CHUNKS
+    PNG_NO_WRITE_ANCILLARY_CHUNKS
+PNG_MAX_UINT was replaced with PNG_UINT_31_MAX.  It has been
+deprecated since libpng-1.0.16 and libpng-1.2.6.
+The function
+    png_check_sig(sig, num)
+was replaced with
+    !png_sig_cmp(sig, 0, num)
+It has been deprecated since libpng-0.90.
+The function
+    png_set_gray_1_2_4_to_8()
+which also expands tRNS to alpha was replaced with
+    png_set_expand_gray_1_2_4_to_8()
+which does not. It has been deprecated since libpng-1.0.18 and 1.2.9.
+IX.  Changes to Libpng from version 1.0.x/1.2.x to 1.4.x
+Private libpng prototypes and macro definitions were moved from
+png.h and pngconf.h into a new pngpriv.h header file.
+Functions png_set_benign_errors(), png_benign_error(), and
+png_chunk_benign_error() were added.
+Support for setting the maximum amount of memory that the application
+will allocate for reading chunks was added, as a security measure.
+The functions png_set_chunk_cache_max() and png_get_chunk_cache_max()
+were added to the library.
+We implemented support for I/O states by adding png_ptr member io_state
+and functions png_get_io_chunk_name() and png_get_io_state() in pngget.c
+We added PNG_TRANSFORM_GRAY_TO_RGB to the available high-level
+input transforms.
+Checking for and reporting of errors in the IHDR chunk is more thorough.
+Support for global arrays was removed, to improve thread safety.
+Some obsolete/deprecated macros and functions have been removed.
+Typecasted NULL definitions such as
+   #define png_voidp_NULL            (png_voidp)NULL
+were eliminated.  If you used these in your application, just use
+NULL instead.
+The png_struct and info_struct members "trans" and "trans_values" were
+changed to "trans_alpha" and "trans_color", respectively.
+The obsolete, unused pnggccrd.c and pngvcrd.c files and related makefiles
+were removed.
+The PNG_1_0_X and PNG_1_2_X macros were eliminated.
+The PNG_LEGACY_SUPPORTED macro was eliminated.
+Many WIN32_WCE #ifdefs were removed.
+The functions png_read_init(info_ptr), png_write_init(info_ptr),
+png_info_init(info_ptr), png_read_destroy(), and png_write_destroy()
+have been removed.  They have been deprecated since libpng-0.95.
+The png_permit_empty_plte() was removed. It has been deprecated
+since libpng-1.0.9.  Use png_permit_mng_features() instead.
+We removed the obsolete stub functions png_get_mmx_flagmask(),
+png_set_mmx_thresholds(), png_get_asm_flags(),
+png_get_mmx_bitdepth_threshold(), png_get_mmx_rowbytes_threshold(),
+png_set_asm_flags(), and png_mmx_supported()
+We removed the obsolete png_check_sig(), png_memcpy_check(), and
+png_memset_check() functions.  Instead use !png_sig_cmp(), memcpy(),
+and memset(), respectively.
+The function png_set_gray_1_2_4_to_8() was removed. It has been
+deprecated since libpng-1.0.18 and 1.2.9, when it was replaced with
+png_set_expand_gray_1_2_4_to_8() because the former function also
+expanded any tRNS chunk to an alpha channel.
+Macros for png_get_uint_16, png_get_uint_32, and png_get_int_32
+were added and are used by default instead of the corresponding
+functions. Unfortunately,
+from libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the
+function) incorrectly returned a value of type png_uint_32.
+We changed the prototype for png_malloc() from
+    png_malloc(png_structp png_ptr, png_uint_32 size)
+to
+    png_malloc(png_structp png_ptr, png_alloc_size_t size)
+This also applies to the prototype for the user replacement malloc_fn().
+The png_calloc() function was added and is used in place of
+of "png_malloc(); memset();" except in the case in png_read_png()
+where the array consists of pointers; in this case a "for" loop is used
+after the png_malloc() to set the pointers to NULL, to give robust.
+behavior in case the application runs out of memory part-way through
+the process.
+We changed the prototypes of png_get_compression_buffer_size() and
+png_set_compression_buffer_size() to work with png_size_t instead of
+png_uint_32.
+Support for numbered error messages was removed by default, since we
+never got around to actually numbering the error messages. The function
+png_set_strip_error_numbers() was removed from the library by default.
+The png_zalloc() and png_zfree() functions are no longer exported.
+The png_zalloc() function no longer zeroes out the memory that it
+allocates.
+Support for dithering was disabled by default in libpng-1.4.0, because
+it has not been well tested and doesn't actually "dither".
+The code was not
+removed, however, and could be enabled by building libpng with
+PNG_READ_DITHER_SUPPORTED defined.  In libpng-1.4.2, this support
+was reenabled, but the function was renamed png_set_quantize() to
+reflect more accurately what it actually does.  At the same time,
+the PNG_DITHER_[RED,GREEN_BLUE]_BITS macros were also renamed to
+PNG_QUANTIZE_[RED,GREEN,BLUE]_BITS, and PNG_READ_DITHER_SUPPORTED
+was renamed to PNG_READ_QUANTIZE_SUPPORTED.
+We removed the trailing '.' from the warning and error messages.
+X.  Changes to Libpng from version 1.4.x to 1.5.x
+From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the
+function) incorrectly returned a value of type png_uint_32.
+A. Changes that affect users of libpng
+There are no substantial API changes between the non-deprecated parts of
+the 1.4.5 API and the 1.5.0 API, however the ability to directly access
+the main libpng control structures, png_struct and png_info, deprecated
+in earlier versions of libpng, has been completely removed from
+libpng 1.5.
+We no longer include zlib.h in png.h.  Applications that need access
+to information in zlib.h will need to add the '#include "zlib.h"'
+directive.  It does not matter whether it is placed prior to or after
+the '"#include png.h"' directive.
+We moved the png_strcpy(), png_strncpy(), png_strlen(), png_memcpy(),
+png_memcmp(), png_sprintf, and png_memcpy() macros into a private
+header file (pngpriv.h) that is not accessible to applications.
+In png_get_iCCP, the type of "profile" was changed from png_charpp
+to png_bytepp, and in png_set_iCCP, from png_charp to png_const_bytep.
+There are changes of form in png.h, including new and changed macros to
+declare parts of the API.  Some API functions with arguments that are
+pointers to data not modified within the function have been corrected to
+declare these arguments with PNG_CONST.
+Much of the internal use of C macros to control the library build has also
+changed and some of this is visible in the exported header files, in
+particular the use of macros to control data and API elements visible
+during application compilation may require significant revision to
+application code.  (It is extremely rare for an application to do this.)
+Any program that compiled against libpng 1.4 and did not use deprecated
+features or access internal library structures should compile and work
+against libpng 1.5, except for the change in the prototype for
+png_get_iCCP() and png_set_iCCP() API functions mentioned above.
+libpng 1.5.0 adds PNG_ PASS macros to help in the reading and writing of
+interlaced images.  The macros return the number of rows and columns in
+each pass and information that can be used to de-interlace and (if
+absolutely necessary) interlace an image.
+libpng 1.5.0 adds an API png_longjmp(png_ptr, value).  This API calls
+the application-provided png_longjmp_ptr on the internal, but application
+initialized, longjmp buffer.  It is provided as a convenience to avoid
+the need to use the png_jmpbuf macro, which had the unnecessary side
+effect of resetting the internal png_longjmp_ptr value.
+libpng 1.5.0 includes a complete fixed point API.  By default this is
+present along with the corresponding floating point API.  In general the
+fixed point API is faster and smaller than the floating point one because
+the PNG file format used fixed point, not floating point.  This applies
+even if the library uses floating point in internal calculations.  A new
+macro, PNG_FLOATING_ARITHMETIC_SUPPORTED, reveals whether the library
+uses floating point arithmetic (the default) or fixed point arithmetic
+internally for performance critical calculations such as gamma correction.
+In some cases, the gamma calculations may produce slightly different
+results.  This has changed the results in png_rgb_to_gray and in alpha
+composition (png_set_background for example). This applies even if the
+original image was already linear (gamma == 1.0) and, therefore, it is
+not necessary to linearize the image.  This is because libpng has *not*
+been changed to optimize that case correctly, yet.
+Fixed point support for the sCAL chunk comes with an important caveat;
+the sCAL specification uses a decimal encoding of floating point values
+and the accuracy of PNG fixed point values is insufficient for
+representation of these values. Consequently a "string" API
+(png_get_sCAL_s and png_set_sCAL_s) is the only reliable way of reading
+arbitrary sCAL chunks in the absence of either the floating point API or
+internal floating point calculations.
+Applications no longer need to include the optional distribution header
+file pngusr.h or define the corresponding macros during application
+build in order to see the correct variant of the libpng API.  From 1.5.0
+application code can check for the corresponding _SUPPORTED macro:
+#ifdef PNG_INCH_CONVERSIONS_SUPPORTED
+   /* code that uses the inch conversion APIs. */
+#endif
+This macro will only be defined if the inch conversion functions have been
+compiled into libpng.  The full set of macros, and whether or not support
+has been compiled in, are available in the header file pnglibconf.h.
+This header file is specific to the libpng build.  Notice that prior to
+1.5.0 the _SUPPORTED macros would always have the default definition unless
+reset by pngusr.h or by explicit settings on the compiler command line.
+These settings may produce compiler warnings or errors in 1.5.0 because
+of macro redefinition.
+From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the
+function) incorrectly returned a value of type png_uint_32.  libpng 1.5.0
+is consistent with the implementation in 1.4.5 and 1.2.x (where the macro
+did not exist.)
+Applications can now choose whether to use these macros or to call the
+corresponding function by defining PNG_USE_READ_MACROS or
+PNG_NO_USE_READ_MACROS before including png.h.  Notice that this is
+only supported from 1.5.0 -defining PNG_NO_USE_READ_MACROS prior to 1.5.0
+will lead to a link failure.
+Prior to libpng-1.5.4, the zlib compressor used the same set of parameters
+when compressing the IDAT data and textual data such as zTXt and iCCP.
+In libpng-1.5.4 we reinitialized the zlib stream for each type of data.
+We added five png_set_text_*() functions for setting the parameters to
+use with textual data.
+Prior to libpng-1.5.4, the PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED
+option was off by default, and slightly inaccurate scaling occurred.
+This option can no longer be turned off, and the choice of accurate
+or inaccurate 16-to-8 scaling is by using the new png_set_scale_16_to_8()
+API for accurate scaling or the old png_set_strip_16_to_8() API for simple
+chopping.
+Prior to libpng-1.5.4, the png_set_user_limits() function could only be
+used to reduce the width and height limits from the value of
+PNG_USER_WIDTH_MAX and PNG_USER_HEIGHT_MAX, although this document said
+that it could be used to override them.  Now this function will reduce or
+increase the limits.
+B. Changes to the build and configuration of libpng
+Details of internal changes to the library code can be found in the CHANGES
+file and in the GIT repository logs.  These will be of no concern to the vast
+majority of library users or builders, however the few who configure libpng
+to a non-default feature set may need to change how this is done.
+There should be no need for library builders to alter build scripts if
+these use the distributed build support - configure or the makefiles -
+however users of the makefiles may care to update their build scripts
+to build pnglibconf.h where the corresponding makefile does not do so.
+Building libpng with a non-default configuration has changed completely.
+The old method using pngusr.h should still work correctly even though the
+way pngusr.h is used in the build has been changed; however, library
+builders will probably want to examine the changes to take advantage of
+new capabilities and to simplify their build system.
+B.1 Specific changes to library configuration capabilities
+The library now supports a complete fixed point implementation and can
+thus be used on systems that have no floating point support or very
+limited or slow support.  Previously gamma correction, an essential part
+of complete PNG support, required reasonably fast floating point.
+As part of this the choice of internal implementation has been made
+independent of the choice of fixed versus floating point APIs and all the
+missing fixed point APIs have been implemented.
+The exact mechanism used to control attributes of API functions has
+changed.  A single set of operating system independent macro definitions
+is used and operating system specific directives are defined in
+pnglibconf.h
+As part of this the mechanism used to choose procedure call standards on
+those systems that allow a choice has been changed.  At present this only
+affects certain Microsoft (DOS, Windows) and IBM (OS/2) operating systems
+running on Intel processors.  As before, PNGAPI is defined where required
+to control the exported API functions; however, two new macros, PNGCBAPI
+and PNGCAPI, are used instead for callback functions (PNGCBAPI) and
+(PNGCAPI) for functions that must match a C library prototype (currently
+only png_longjmp_ptr, which must match the C longjmp function.)  The new
+approach is documented in pngconf.h
+Despite these changes, libpng 1.5.0 only supports the native C function
+calling standard on those platforms tested so far (__cdecl on Microsoft
+Windows).  This is because the support requirements for alternative
+calling conventions seem to no longer exist.  Developers who find it
+necessary to set PNG_API_RULE to 1 should advise the mailing list
+(png-mng-implement) of this and library builders who use Openwatcom and
+therefore set PNG_API_RULE to 2 should also contact the mailing list.
+A new test program, pngvalid, is provided in addition to pngtest.
+pngvalid validates the arithmetic accuracy of the gamma correction
+calculations and includes a number of validations of the file format.
+A subset of the full range of tests is run when "make check" is done
+(in the 'configure' build.)  pngvalid also allows total allocated memory
+usage to be evaluated and performs additional memory overwrite validation.
+Many changes to individual feature macros have been made. The following
+are the changes most likely to be noticed by library builders who
+configure libpng:
+1) All feature macros now have consistent naming:
+#define PNG_NO_feature turns the feature off
+#define PNG_feature_SUPPORTED turns the feature on
+pnglibconf.h contains one line for each feature macro which is either:
+#define PNG_feature_SUPPORTED
+if the feature is supported or:
+/*#undef PNG_feature_SUPPORTED*/
+if it is not.  Library code consistently checks for the 'SUPPORTED' macro.
+It does not, and libpng applications should not, check for the 'NO' macro
+which will not normally be defined even if the feature is not supported.
+The 'NO' macros are only used internally for setting or not setting the
+corresponding 'SUPPORTED' macros.
+Compatibility with the old names is provided as follows:
+PNG_INCH_CONVERSIONS turns on PNG_INCH_CONVERSIONS_SUPPORTED
+And the following definitions disable the corresponding feature:
+PNG_SETJMP_NOT_SUPPORTED disables SETJMP
+PNG_READ_TRANSFORMS_NOT_SUPPORTED disables READ_TRANSFORMS
+PNG_NO_READ_COMPOSITED_NODIV disables READ_COMPOSITE_NODIV
+PNG_WRITE_TRANSFORMS_NOT_SUPPORTED disables WRITE_TRANSFORMS
+PNG_READ_ANCILLARY_CHUNKS_NOT_SUPPORTED disables READ_ANCILLARY_CHUNKS
+PNG_WRITE_ANCILLARY_CHUNKS_NOT_SUPPORTED disables WRITE_ANCILLARY_CHUNKS
+Library builders should remove use of the above, inconsistent, names.
+2) Warning and error message formatting was previously conditional on
+the STDIO feature. The library has been changed to use the
+CONSOLE_IO feature instead. This means that if CONSOLE_IO is disabled
+the library no longer uses the printf(3) functions, even though the
+default read/write implementations use (FILE) style stdio.h functions.
+3) Three feature macros now control the fixed/floating point decisions:
+PNG_FLOATING_POINT_SUPPORTED enables the floating point APIs
+PNG_FIXED_POINT_SUPPORTED enables the fixed point APIs; however, in
+practice these are normally required internally anyway (because the PNG
+file format is fixed point), therefore in most cases PNG_NO_FIXED_POINT
+merely stops the function from being exported.
+PNG_FLOATING_ARITHMETIC_SUPPORTED chooses between the internal floating
+point implementation or the fixed point one.  Typically the fixed point
+implementation is larger and slower than the floating point implementation
+on a system that supports floating point, however it may be faster on a
+system which lacks floating point hardware and therefore uses a software
+emulation.
+4) Added PNG_{READ,WRITE}_INT_FUNCTIONS_SUPPORTED.  This allows the
+functions to read and write ints to be disabled independently of
+PNG_USE_READ_MACROS, which allows libpng to be built with the functions
+even though the default is to use the macros - this allows applications
+to choose at app buildtime whether or not to use macros (previously
+impossible because the functions weren't in the default build.)
+B.2 Changes to the configuration mechanism
+Prior to libpng-1.5.0 library builders who needed to configure libpng
+had either to modify the exported pngconf.h header file to add system
+specific configuration or had to write feature selection macros into
+pngusr.h and cause this to be included into pngconf.h by defining
+PNG_USER_CONFIG. The latter mechanism had the disadvantage that an
+application built without PNG_USER_CONFIG defined would see the
+unmodified, default, libpng API and thus would probably fail to link.
+These mechanisms still work in the configure build and in any makefile
+build that builds pnglibconf.h, although the feature selection macros
+have changed somewhat as described above.  In 1.5.0, however, pngusr.h is
+processed only once, when the exported header file pnglibconf.h is built.
+pngconf.h no longer includes pngusr.h, therefore pngusr.h is ignored after the
+build of pnglibconf.h and it is never included in an application build.
+The rarely used alternative of adding a list of feature macros to the
+CFLAGS setting in the build also still works, however the macros will be
+copied to pnglibconf.h and this may produce macro redefinition warnings
+when the individual C files are compiled.
+All configuration now only works if pnglibconf.h is built from
+scripts/pnglibconf.dfa.  This requires the program awk.  Brian Kernighan
+(the original author of awk) maintains C source code of that awk and this
+and all known later implementations (often called by subtly different
+names - nawk and gawk for example) are adequate to build pnglibconf.h.
+The Sun Microsystems (now Oracle) program 'awk' is an earlier version
+and does not work; this may also apply to other systems that have a
+functioning awk called 'nawk'.
+Configuration options are now documented in scripts/pnglibconf.dfa.  This
+file also includes dependency information that ensures a configuration is
+consistent; that is, if a feature is switched off dependent features are
+also removed.  As a recommended alternative to using feature macros in
+pngusr.h a system builder may also define equivalent options in pngusr.dfa
+(or, indeed, any file) and add that to the configuration by setting
+DFA_XTRA to the file name.  The makefiles in contrib/pngminim illustrate
+how to do this, and a case where pngusr.h is still required.
+XI. Detecting libpng
+The png_get_io_ptr() function has been present since libpng-0.88, has never
+changed, and is unaffected by conditional compilation macros.  It is the
+best choice for use in configure scripts for detecting the presence of any
+libpng version since 0.88.  In an autoconf "configure.in" you could use
+    AC_CHECK_LIB(png, png_get_io_ptr, ...
+XII. Source code repository
+Since about February 2009, version 1.2.34, libpng has been under "git" source
+control.  The git repository was built from old libpng-x.y.z.tar.gz files
+going back to version 0.70.  You can access the git repository (read only)
+at
+    git://libpng.git.sourceforge.net/gitroot/libpng
+or you can browse it via "gitweb" at
+    http://libpng.git.sourceforge.net/git/gitweb.cgi?p=libpng
+Patches can be sent to glennrp at users.sourceforge.net or to
+png-mng-implement at lists.sourceforge.net or you can upload them to
+the libpng bug tracker at
+    http://libpng.sourceforge.net
+We also accept patches built from the tar or zip distributions, and
+simple verbal discriptions of bug fixes, reported either to the
+SourceForge bug tracker, to the png-mng-implement at lists.sf.net
+mailing list, or directly to glennrp.
+XIII. Coding style
+Our coding style is similar to the "Allman" style, with curly
+braces on separate lines:
+    if (condition)
+    {
+       action;
+    }
+    else if (another condition)
+    {
+       another action;
+    }
+The braces can be omitted from simple one-line actions:
+    if (condition)
+       return (0);
+We use 3-space indentation, except for continued statements which
+are usually indented the same as the first line of the statement
+plus four more spaces.
+For macro definitions we use 2-space indentation, always leaving the "#"
+in the first column.
+    #ifndef PNG_NO_FEATURE
+    #  ifndef PNG_FEATURE_SUPPORTED
+    #    define PNG_FEATURE_SUPPORTED
+    #  endif
+    #endif
+Comments appear with the leading "/*" at the same indentation as
+the statement that follows the comment:
+    /* Single-line comment */
+    statement;
+    /* This is a multiple-line
+     * comment.
+     */
+    statement;
+Very short comments can be placed after the end of the statement
+to which they pertain:
+    statement;    /* comment */
+We don't use C++ style ("//") comments. We have, however,
+used them in the past in some now-abandoned MMX assembler
+code.
+Functions and their curly braces are not indented, and
+exported functions are marked with PNGAPI:
+ /* This is a public function that is visible to
+  * application programmers. It does thus-and-so.
+  */
+ void PNGAPI
+ png_exported_function(png_ptr, png_info, foo)
+ {
+    body;
+ }
+The prototypes for all exported functions appear in png.h,
+above the comment that says
+    /* Maintainer: Put new public prototypes here ... */
+We mark all non-exported functions with "/* PRIVATE */"":
+ void /* PRIVATE */
+ png_non_exported_function(png_ptr, png_info, foo)
+ {
+    body;
+ }
+The prototypes for non-exported functions (except for those in
+pngtest) appear in
+pngpriv.h
+above the comment that says
+  /* Maintainer: Put new private prototypes here ^ and in libpngpf.3 */
+To avoid polluting the global namespace, the names of all exported
+functions and variables begin with  "png_", and all publicly visible C
+preprocessor macros begin with "PNG_".  We request that applications that
+use libpng *not* begin any of their own symbols with either of these strings.
+We put a space after each comma and after each semicolon
+in "for" statements, and we put spaces before and after each
+C binary operator and after "for" or "while", and before
+"?".  We don't put a space between a typecast and the expression
+being cast, nor do we put one between a function name and the
+left parenthesis that follows it:
+    for (i = 2; i > 0; --i)
+       y[i] = a(x) + (int)b;
+We prefer #ifdef and #ifndef to #if defined() and if !defined()
+when there is only one macro being tested.
+We prefer to express integers that are used as bit masks in hex format,
+with an even number of lower-case hex digits (e.g., 0x00, 0xff, 0x0100).
+We do not use the TAB character for indentation in the C sources.
+Lines do not exceed 80 characters.
+Other rules can be inferred by inspecting the libpng source.
+XIV. Y2K Compliance in libpng
+February 18, 2012
+Since the PNG Development group is an ad-hoc body, we can't make
+an official declaration.
+This is your unofficial assurance that libpng from version 0.71 and
+upward through 1.5.9 are Y2K compliant.  It is my belief that earlier
+versions were also Y2K compliant.
+Libpng only has three year fields.  One is a 2-byte unsigned integer that
+will hold years up to 65535.  The other two hold the date in text
+format, and will hold years up to 9999.
+The integer is
+    "png_uint_16 year" in png_time_struct.
+The strings are
+    "png_charp time_buffer" in png_struct and
+    "near_time_buffer", which is a local character string in png.c.
+There are seven time-related functions:
+    png_convert_to_rfc_1123() in png.c
+      (formerly png_convert_to_rfc_1152() in error)
+    png_convert_from_struct_tm() in pngwrite.c, called
+      in pngwrite.c
+    png_convert_from_time_t() in pngwrite.c
+    png_get_tIME() in pngget.c
+    png_handle_tIME() in pngrutil.c, called in pngread.c
+    png_set_tIME() in pngset.c
+    png_write_tIME() in pngwutil.c, called in pngwrite.c
+All appear to handle dates properly in a Y2K environment.  The
+png_convert_from_time_t() function calls gmtime() to convert from system
+clock time, which returns (year - 1900), which we properly convert to
+the full 4-digit year.  There is a possibility that applications using
+libpng are not passing 4-digit years into the png_convert_to_rfc_1123()
+function, or that they are incorrectly passing only a 2-digit year
+instead of "year - 1900" into the png_convert_from_struct_tm() function,
+but this is not under our control.  The libpng documentation has always
+stated that it works with 4-digit years, and the APIs have been
+documented as such.
+The tIME chunk itself is also Y2K compliant.  It uses a 2-byte unsigned
+integer to hold the year, and can hold years as large as 65535.
+zlib, upon which libpng depends, is also Y2K compliant.  It contains
+no date-related code.
+   Glenn Randers-Pehrson
+   libpng maintainer
+   PNG Development Group
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/libpng.3 b/libraries/irrlicht-1.8/source/Irrlicht/libpng/libpng.3
new file mode 100644
index 0000000..1d72ab4
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/libpng.3
@@ -0,0 +1,5952 @@
+.TH LIBPNG 3 "February 18, 2012"
+.SH NAME
+libpng \- Portable Network Graphics (PNG) Reference Library 1.5.9
+.SH SYNOPSIS
+\fI\fB
+\fB#include <png.h>\fP
+\fI\fB
+\fBpng_uint_32 png_access_version_number \fI(void\fP\fB);\fP
+\fI\fB
+\fBvoid png_benign_error (png_structp \fP\fIpng_ptr\fP\fB, png_const_charp \fIerror\fP\fB);\fP
+\fI\fB
+\fBvoid png_build_grayscale_palette (int \fP\fIbit_depth\fP\fB, png_colorp \fIpalette\fP\fB);\fP
+\fI\fB
+\fBpng_voidp png_calloc (png_structp \fP\fIpng_ptr\fP\fB, png_alloc_size_t \fIsize\fP\fB);\fP
+\fI\fB
+\fBvoid png_chunk_benign_error (png_structp \fP\fIpng_ptr\fP\fB, png_const_charp \fIerror\fP\fB);\fP
+\fI\fB
+\fBvoid png_chunk_error (png_structp \fP\fIpng_ptr\fP\fB, png_const_charp \fIerror\fP\fB);\fP
+\fI\fB
+\fBvoid png_chunk_warning (png_structp \fP\fIpng_ptr\fP\fB, png_const_charp \fImessage\fP\fB);\fP
+\fI\fB
+\fBvoid png_convert_from_struct_tm (png_timep \fP\fIptime\fP\fB, struct tm FAR * \fIttime\fP\fB);\fP
+\fI\fB
+\fBvoid png_convert_from_time_t (png_timep \fP\fIptime\fP\fB, time_t \fIttime\fP\fB);\fP
+\fI\fB
+\fBpng_charp png_convert_to_rfc1123 (png_structp \fP\fIpng_ptr\fP\fB, png_timep \fIptime\fP\fB);\fP
+\fI\fB
+\fBpng_infop png_create_info_struct (png_structp \fIpng_ptr\fP\fB);\fP
+\fI\fB
+\fBpng_structp png_create_read_struct (png_const_charp \fP\fIuser_png_ver\fP\fB, png_voidp \fP\fIerror_ptr\fP\fB, png_error_ptr \fP\fIerror_fn\fP\fB, png_error_ptr \fIwarn_fn\fP\fB);\fP
+\fI\fB
+\fBpng_structp png_create_read_struct_2 (png_const_charp \fP\fIuser_png_ver\fP\fB, png_voidp \fP\fIerror_ptr\fP\fB, png_error_ptr \fP\fIerror_fn\fP\fB, png_error_ptr \fP\fIwarn_fn\fP\fB, png_voidp \fP\fImem_ptr\fP\fB, png_malloc_ptr \fP\fImalloc_fn\fP\fB, png_free_ptr \fIfree_fn\fP\fB);\fP
+\fI\fB
+\fBpng_structp png_create_write_struct (png_const_charp \fP\fIuser_png_ver\fP\fB, png_voidp \fP\fIerror_ptr\fP\fB, png_error_ptr \fP\fIerror_fn\fP\fB, png_error_ptr \fIwarn_fn\fP\fB);\fP
+\fI\fB
+\fBpng_structp png_create_write_struct_2 (png_const_charp \fP\fIuser_png_ver\fP\fB, png_voidp \fP\fIerror_ptr\fP\fB, png_error_ptr \fP\fIerror_fn\fP\fB, png_error_ptr \fP\fIwarn_fn\fP\fB, png_voidp \fP\fImem_ptr\fP\fB, png_malloc_ptr \fP\fImalloc_fn\fP\fB, png_free_ptr \fIfree_fn\fP\fB);\fP
+\fI\fB
+\fBvoid png_data_freer (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fP\fIfreer\fP\fB, png_uint_32 \fImask)\fP\fB);\fP
+\fI\fB
+\fBvoid png_destroy_info_struct (png_structp \fP\fIpng_ptr\fP\fB, png_infopp \fIinfo_ptr_ptr\fP\fB);\fP
+\fI\fB
+\fBvoid png_destroy_read_struct (png_structpp \fP\fIpng_ptr_ptr\fP\fB, png_infopp \fP\fIinfo_ptr_ptr\fP\fB, png_infopp \fIend_info_ptr_ptr\fP\fB);\fP
+\fI\fB
+\fBvoid png_destroy_write_struct (png_structpp \fP\fIpng_ptr_ptr\fP\fB, png_infopp \fIinfo_ptr_ptr\fP\fB);\fP
+\fI\fB
+\fBvoid png_err (png_structp \fIpng_ptr\fP\fB);\fP
+\fI\fB
+\fBvoid png_error (png_structp \fP\fIpng_ptr\fP\fB, png_const_charp \fIerror\fP\fB);\fP
+\fI\fB
+\fBvoid png_free (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fIptr\fP\fB);\fP
+\fI\fB
+\fBvoid png_free_chunk_list (png_structp \fIpng_ptr\fP\fB);\fP
+\fI\fB
+\fBvoid png_free_default (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fIptr\fP\fB);\fP
+\fI\fB
+\fBvoid png_free_data (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fInum\fP\fB);\fP
+\fI\fB
+\fBpng_byte png_get_bit_depth (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
+\fI\fB
+\fBpng_uint_32 png_get_bKGD (png_const_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_color_16p \fI*background\fP\fB);\fP
+\fI\fB
+\fBpng_byte png_get_channels (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
+\fI\fB
+\fBpng_uint_32 png_get_cHRM (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, double \fP\fI*white_x\fP\fB, double \fP\fI*white_y\fP\fB, double \fP\fI*red_x\fP\fB, double \fP\fI*red_y\fP\fB, double \fP\fI*green_x\fP\fB, double \fP\fI*green_y\fP\fB, double \fP\fI*blue_x\fP\fB, double \fI*blue_y\fP\fB);\fP
+\fI\fB
+\fBpng_uint_32 png_get_cHRM_fixed (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fI*white_x\fP\fB, png_uint_32 \fP\fI*white_y\fP\fB, png_uint_32 \fP\fI*red_x\fP\fB, png_uint_32 \fP\fI*red_y\fP\fB, png_uint_32 \fP\fI*green_x\fP\fB, png_uint_32 \fP\fI*green_y\fP\fB, png_uint_32 \fP\fI*blue_x\fP\fB, png_uint_32 \fI*blue_y\fP\fB);\fP
+\fI\fB
+\fBpng_uint_32 png_get_cHRM_XYZ (png_structp \fIpng_ptr,
+\fBpng_const_infop \fP\fIinfo_ptr\fP\fB, double \fP\fI*red_X\fP\fB, double \fP\fI*red_Y\fP\fB, double \fI*red_Z,
+\fBdouble \fP\fI*green_X\fP\fB, double \fP\fI*green_Y\fP\fB, double \fP\fI*green_Z\fP\fB, double \fI*blue_X,
+\fBdouble \fP\fI*blue_Y\fP\fB, double \fI*blue_Z\fP\fB);\fP
+\fI\fB
+\fBpng_uint_32 png_get_cHRM_XYZ_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_fixed_point \fP\fI*int_red_X\fP\fB, png_fixed_point \fP\fI*int_red_Y\fP\fB, png_fixed_point \fP\fI*int_red_Z\fP\fB, png_fixed_point \fP\fI*int_green_X\fP\fB, png_fixed_point \fP\fI*int_green_Y\fP\fB, png_fixed_point \fP\fI*int_green_Z\fP\fB, png_fixed_point \fP\fI*int_blue_X\fP\fB, png_fixed_point \fP\fI*int_blue_Y\fP\fB, png_fixed_point \fI*int_blue_Z\fP\fB);\fP
+\fI\fB
+\fBpng_uint_32 png_get_chunk_cache_max (png_const_structp \fIpng_ptr\fP\fB);\fP
+\fI\fB
+\fBpng_alloc_size_t png_get_chunk_malloc_max (png_const_structp \fIpng_ptr\fP\fB);\fP
+\fI\fB
+\fBpng_byte png_get_color_type (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
+\fI\fB
+\fBpng_uint_32 png_get_compression_buffer_size (png_const_structp \fIpng_ptr\fP\fB);\fP
+\fI\fB
+\fBpng_byte png_get_compression_type (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
+\fI\fB
+\fBpng_byte png_get_copyright (png_const_structp \fIpng_ptr\fP\fB);\fP
+\fI\fB
+\fBpng_uint_32 png_get_current_row_number \fI(png_const_structp\fP\fB);\fP
+\fI\fB
+\fBpng_byte png_get_current_pass_number \fI(png_const_structp\fP\fB);\fP
+\fI\fB
+\fBpng_voidp png_get_error_ptr (png_const_structp \fIpng_ptr\fP\fB);\fP
+\fI\fB
+\fBpng_byte png_get_filter_type (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
+\fI\fB
+\fBpng_uint_32 png_get_gAMA (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, double \fI*file_gamma\fP\fB);\fP
+\fI\fB
+\fBpng_uint_32 png_get_gAMA_fixed (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fI*int_file_gamma\fP\fB);\fP
+\fI\fB
+\fBpng_byte png_get_header_ver (png_const_structp \fIpng_ptr\fP\fB);\fP
+\fI\fB
+\fBpng_byte png_get_header_version (png_const_structp \fIpng_ptr\fP\fB);\fP
+\fI\fB
+\fBpng_uint_32 png_get_hIST (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_uint_16p \fI*hist\fP\fB);\fP
+\fI\fB
+\fBpng_uint_32 png_get_iCCP (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_charpp \fP\fIname\fP\fB, int \fP\fI*compression_type\fP\fB, png_bytepp \fP\fIprofile\fP\fB, png_uint_32 \fI*proflen\fP\fB);\fP
+\fI\fB
+\fBpng_uint_32 png_get_IHDR (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fI*width\fP\fB, png_uint_32 \fP\fI*height\fP\fB, int \fP\fI*bit_depth\fP\fB, int \fP\fI*color_type\fP\fB, int \fP\fI*interlace_type\fP\fB, int \fP\fI*compression_type\fP\fB, int \fI*filter_type\fP\fB);\fP
+\fI\fB
+\fBpng_uint_32 png_get_image_height (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
+\fI\fB
+\fBpng_uint_32 png_get_image_width (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
+\fI\fB
+\fBpng_int_32 png_get_int_32 (png_bytep \fIbuf\fP\fB);\fP
+\fI\fB
+\fBpng_byte png_get_interlace_type (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
+\fI\fB
+\fBpng_const_bytep png_get_io_chunk_name (png_structp \fIpng_ptr\fP\fB);\fP
+\fI\fB
+\fBpng_uint_32 png_get_io_chunk_type (png_const_structp \fIpng_ptr\fP\fB);\fP
+\fI\fB
+\fBpng_voidp png_get_io_ptr (png_structp \fIpng_ptr\fP\fB);\fP
+\fI\fB
+\fBpng_uint_32 png_get_io_state (png_structp \fIpng_ptr\fP\fB);\fP
+\fI\fB
+\fBpng_byte png_get_libpng_ver (png_const_structp \fIpng_ptr\fP\fB);\fP
+\fI\fB
+\fBpng_voidp png_get_mem_ptr (png_const_structp \fIpng_ptr\fP\fB);\fP
+\fI\fB
+\fBpng_uint_32 png_get_oFFs (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fI*offset_x\fP\fB, png_uint_32 \fP\fI*offset_y\fP\fB, int \fI*unit_type\fP\fB);\fP
+\fI\fB
+\fBpng_uint_32 png_get_pCAL (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_charp \fP\fI*purpose\fP\fB, png_int_32 \fP\fI*X0\fP\fB, png_int_32 \fP\fI*X1\fP\fB, int \fP\fI*type\fP\fB, int \fP\fI*nparams\fP\fB, png_charp \fP\fI*units\fP\fB, png_charpp \fI*params\fP\fB);\fP
+\fI\fB
+\fBpng_uint_32 png_get_pHYs (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fI*res_x\fP\fB, png_uint_32 \fP\fI*res_y\fP\fB, int \fI*unit_type\fP\fB);\fP
+\fI\fB
+\fBfloat png_get_pixel_aspect_ratio (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
+\fI\fB
+\fBpng_uint_32 png_get_pHYs_dpi (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fI*res_x\fP\fB, png_uint_32 \fP\fI*res_y\fP\fB, int \fI*unit_type\fP\fB);\fP
+\fI\fB
+\fBpng_fixed_point png_get_pixel_aspect_ratio_fixed (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
+\fI\fB
+\fBpng_uint_32 png_get_pixels_per_inch (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
+\fI\fB
+\fBpng_uint_32 png_get_pixels_per_meter (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
+\fI\fB
+\fBpng_voidp png_get_progressive_ptr (png_const_structp \fIpng_ptr\fP\fB);\fP
+\fI\fB
+\fBpng_uint_32 png_get_PLTE (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_colorp \fP\fI*palette\fP\fB, int \fI*num_palette\fP\fB);\fP
+\fI\fB
+\fBpng_byte png_get_rgb_to_gray_status (png_const_structp \fIpng_ptr)
+\fBpng_uint_32 png_get_rowbytes (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
+\fI\fB
+\fBpng_bytepp png_get_rows (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
+\fI\fB
+\fBpng_uint_32 png_get_sBIT (png_const_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_color_8p \fI*sig_bit\fP\fB);\fP
+\fI\fB
+\fBvoid png_get_sCAL (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, int* \fP\fIunit\fP\fB, double* \fP\fIwidth\fP\fB, double* \fIheight\fP\fB);\fP
+\fI\fB
+\fBvoid png_get_sCAL_fixed (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, int* \fP\fIunit\fP\fB, png_fixed_pointp \fP\fIwidth\fP\fB, png_fixed_pointp \fIheight\fP\fB);\fP
+\fI\fB
+\fBvoid png_get_sCAL_s (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, int* \fP\fIunit\fP\fB, png_charpp \fP\fIwidth\fP\fB, png_charpp \fIheight\fP\fB);\fP
+\fI\fB
+\fBpng_bytep png_get_signature (png_const_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+\fI\fB
+\fBpng_uint_32 png_get_sPLT (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_spalette_p \fI*splt_ptr\fP\fB);\fP
+\fI\fB
+\fBpng_uint_32 png_get_sRGB (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, int \fI*file_srgb_intent\fP\fB);\fP
+\fI\fB
+\fBpng_uint_32 png_get_text (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_textp \fP\fI*text_ptr\fP\fB, int \fI*num_text\fP\fB);\fP
+\fI\fB
+\fBpng_uint_32 png_get_tIME (png_const_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_timep \fI*mod_time\fP\fB);\fP
+\fI\fB
+\fBpng_uint_32 png_get_tRNS (png_const_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_bytep \fP\fI*trans_alpha\fP\fB, int \fP\fI*num_trans\fP\fB, png_color_16p \fI*trans_color\fP\fB);\fP
+\fI\fB
+\fB/* This function is really an inline macro. \fI*/
+\fBpng_uint_16 png_get_uint_16 (png_bytep \fIbuf\fP\fB);\fP
+\fI\fB
+\fBpng_uint_32 png_get_uint_31 (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fIbuf\fP\fB);\fP
+\fI\fB
+\fB/* This function is really an inline macro. \fI*/
+\fBpng_uint_32 png_get_uint_32 (png_bytep \fIbuf\fP\fB);\fP
+\fI\fB
+\fBpng_uint_32 png_get_unknown_chunks (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_unknown_chunkpp \fIunknowns\fP\fB);\fP
+\fI\fB
+\fBpng_voidp png_get_user_chunk_ptr (png_const_structp \fIpng_ptr\fP\fB);\fP
+\fI\fB
+\fBpng_uint_32 png_get_user_height_max (png_const_structp \fIpng_ptr\fP\fB);\fP
+\fI\fB
+\fBpng_voidp png_get_user_transform_ptr (png_const_structp \fIpng_ptr\fP\fB);\fP
+\fI\fB
+\fBpng_uint_32 png_get_user_width_max (png_const_structp \fIpng_ptr\fP\fB);\fP
+\fI\fB
+\fBpng_uint_32 png_get_valid (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIflag\fP\fB);\fP
+\fI\fB
+\fBfloat png_get_x_offset_inches (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
+\fI\fB
+\fBpng_fixed_point png_get_x_offset_inches_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
+\fI\fB
+\fBpng_int_32 png_get_x_offset_microns (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
+\fI\fB
+\fBpng_int_32 png_get_x_offset_pixels (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
+\fI\fB
+\fBpng_uint_32 png_get_x_pixels_per_inch (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
+\fI\fB
+\fBpng_uint_32 png_get_x_pixels_per_meter (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
+\fI\fB
+\fBfloat png_get_y_offset_inches (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
+\fI\fB
+\fBpng_fixed_point png_get_y_offset_inches_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
+\fI\fB
+\fBpng_int_32 png_get_y_offset_microns (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
+\fI\fB
+\fBpng_int_32 png_get_y_offset_pixels (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
+\fI\fB
+\fBpng_uint_32 png_get_y_pixels_per_inch (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
+\fI\fB
+\fBpng_uint_32 png_get_y_pixels_per_meter (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
+\fI\fB
+\fBint png_handle_as_unknown (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fIchunk_name\fP\fB);\fP
+\fI\fB
+\fBvoid png_info_init_3 (png_infopp \fP\fIinfo_ptr\fP\fB, png_size_t \fIpng_info_struct_size\fP\fB);\fP
+\fI\fB
+\fBvoid png_init_io (png_structp \fP\fIpng_ptr\fP\fB, FILE \fI*fp\fP\fB);\fP
+\fI\fB
+\fBvoid png_longjmp (png_structp \fP\fIpng_ptr\fP\fB, int \fIval\fP\fB);\fP
+\fI\fB
+\fBpng_voidp png_malloc (png_structp \fP\fIpng_ptr\fP\fB, png_alloc_size_t \fIsize\fP\fB);\fP
+\fI\fB
+\fBpng_voidp png_malloc_default (png_structp \fP\fIpng_ptr\fP\fB, png_alloc_size_t \fIsize\fP\fB);\fP
+\fI\fB
+\fBpng_voidp png_malloc_warn (png_structp \fP\fIpng_ptr\fP\fB, png_alloc_size_t \fIsize\fP\fB);\fP
+\fI\fB
+\fBpng_uint_32 png_permit_mng_features (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fImng_features_permitted\fP\fB);\fP
+\fI\fB
+\fBvoid png_process_data (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_bytep \fP\fIbuffer\fP\fB, png_size_t \fIbuffer_size\fP\fB);\fP
+\fI\fB
+\fBpng_size_t png_process_data_pause \fP\fI(png_structp\fP\fB, int \fIsave\fP\fB);\fP
+\fI\fB
+\fBpng_uint_32 png_process_data_skip \fI(png_structp\fP\fB);\fP
+\fI\fB
+\fBvoid png_progressive_combine_row (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIold_row\fP\fB, png_bytep \fInew_row\fP\fB);\fP
+\fI\fB
+\fBvoid png_read_end (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+\fI\fB
+\fBvoid png_read_image (png_structp \fP\fIpng_ptr\fP\fB, png_bytepp \fIimage\fP\fB);\fP
+\fI\fB
+\fBvoid png_read_info (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+\fI\fB
+\fBvoid png_read_png (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fP\fItransforms\fP\fB, png_voidp \fIparams\fP\fB);\fP
+\fI\fB
+\fBvoid png_read_row (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIrow\fP\fB, png_bytep \fIdisplay_row\fP\fB);\fP
+\fI\fB
+\fBvoid png_read_rows (png_structp \fP\fIpng_ptr\fP\fB, png_bytepp \fP\fIrow\fP\fB, png_bytepp \fP\fIdisplay_row\fP\fB, png_uint_32 \fInum_rows\fP\fB);\fP
+\fI\fB
+\fBvoid png_read_update_info (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+\fI\fB
+\fBint png_reset_zstream (png_structp \fIpng_ptr\fP\fB);\fP
+\fI\fB
+\fBvoid png_save_int_32 (png_bytep \fP\fIbuf\fP\fB, png_int_32 \fIi\fP\fB);\fP
+\fI\fB
+\fBvoid png_save_uint_16 (png_bytep \fP\fIbuf\fP\fB, unsigned int \fIi\fP\fB);\fP
+\fI\fB
+\fBvoid png_save_uint_32 (png_bytep \fP\fIbuf\fP\fB, png_uint_32 \fIi\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_add_alpha (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fP\fIfiller\fP\fB, int \fIflags\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_alpha_mode (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fImode\fP\fB, double \fIoutput_gamma\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_alpha_mode_fixed (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fImode\fP\fB, png_fixed_point \fIoutput_gamma\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_background (png_structp \fP\fIpng_ptr\fP\fB, png_color_16p \fP\fIbackground_color\fP\fB, int \fP\fIbackground_gamma_code\fP\fB, int \fP\fIneed_expand\fP\fB, double \fIbackground_gamma\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_background_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_color_16p \fP\fIbackground_color\fP\fB, int \fP\fIbackground_gamma_code\fP\fB, int \fP\fIneed_expand\fP\fB, png_uint_32 \fIbackground_gamma\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_benign_errors (png_structp \fP\fIpng_ptr\fP\fB, int \fIallowed\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_bgr (png_structp \fIpng_ptr\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_bKGD (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_color_16p \fIbackground\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_cHRM (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, double \fP\fIwhite_x\fP\fB, double \fP\fIwhite_y\fP\fB, double \fP\fIred_x\fP\fB, double \fP\fIred_y\fP\fB, double \fP\fIgreen_x\fP\fB, double \fP\fIgreen_y\fP\fB, double \fP\fIblue_x\fP\fB, double \fIblue_y\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_cHRM_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fIwhite_x\fP\fB, png_uint_32 \fP\fIwhite_y\fP\fB, png_uint_32 \fP\fIred_x\fP\fB, png_uint_32 \fP\fIred_y\fP\fB, png_uint_32 \fP\fIgreen_x\fP\fB, png_uint_32 \fP\fIgreen_y\fP\fB, png_uint_32 \fP\fIblue_x\fP\fB, png_uint_32 \fIblue_y\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_cHRM_XYZ (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, double \fP\fIred_X\fP\fB, double \fP\fIred_Y\fP\fB, double \fP\fIred_Z\fP\fB, double \fP\fIgreen_X\fP\fB, double \fIgreen_Y,
+\fBdouble \fP\fIgreen_Z\fP\fB, double \fP\fIblue_X\fP\fB, double \fP\fIblue_Y\fP\fB, double \fIblue_Z\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_cHRM_XYZ_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_fixed_point \fP\fIint_red_X\fP\fB, png_fixed_point \fP\fIint_red_Y\fP\fB, png_fixed_point \fP\fIint_red_Z\fP\fB, png_fixed_point \fP\fIint_green_X\fP\fB, png_fixed_point \fP\fIint_green_Y\fP\fB, png_fixed_point \fP\fIint_green_Z\fP\fB, png_fixed_point \fP\fIint_blue_X\fP\fB, png_fixed_point \fP\fIint_blue_Y\fP\fB, png_fixed_point \fIint_blue_Z\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_chunk_cache_max (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fIuser_chunk_cache_max\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_compression_level (png_structp \fP\fIpng_ptr\fP\fB, int \fIlevel\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_compression_mem_level (png_structp \fP\fIpng_ptr\fP\fB, int \fImem_level\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_compression_method (png_structp \fP\fIpng_ptr\fP\fB, int \fImethod\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_compression_strategy (png_structp \fP\fIpng_ptr\fP\fB, int \fIstrategy\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_compression_window_bits (png_structp \fP\fIpng_ptr\fP\fB, int \fIwindow_bits\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_crc_action (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fIcrit_action\fP\fB, int \fIancil_action\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_error_fn (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fIerror_ptr\fP\fB, png_error_ptr \fP\fIerror_fn\fP\fB, png_error_ptr \fIwarning_fn\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_expand (png_structp \fIpng_ptr\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_expand_16 (png_structp \fIpng_ptr\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_expand_gray_1_2_4_to_8 (png_structp \fIpng_ptr\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_filler (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fP\fIfiller\fP\fB, int \fIflags\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_filter (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fImethod\fP\fB, int \fIfilters\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_filter_heuristics (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fIheuristic_method\fP\fB, int \fP\fInum_weights\fP\fB, png_doublep \fP\fIfilter_weights\fP\fB, png_doublep \fIfilter_costs\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_filter_heuristics_fixed (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fIheuristic_method\fP\fB, int \fP\fInum_weights\fP\fB, png_fixed_point_p \fP\fIfilter_weights\fP\fB, png_fixed_point_p \fIfilter_costs\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_flush (png_structp \fP\fIpng_ptr\fP\fB, int \fInrows\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_gamma (png_structp \fP\fIpng_ptr\fP\fB, double \fP\fIscreen_gamma\fP\fB, double \fIdefault_file_gamma\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_gamma_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fP\fIscreen_gamma\fP\fB, png_uint_32 \fIdefault_file_gamma\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_gAMA (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, double \fIfile_gamma\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_gAMA_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIfile_gamma\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_gray_1_2_4_to_8 (png_structp \fIpng_ptr\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_gray_to_rgb (png_structp \fIpng_ptr\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_hIST (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_16p \fIhist\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_iCCP (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_const_charp \fP\fIname\fP\fB, int \fP\fIcompression_type\fP\fB, png_const_bytep \fP\fIprofile\fP\fB, png_uint_32 \fIproflen\fP\fB);\fP
+\fI\fB
+\fBint png_set_interlace_handling (png_structp \fIpng_ptr\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_invalid (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fImask\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_invert_alpha (png_structp \fIpng_ptr\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_invert_mono (png_structp \fIpng_ptr\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_IHDR (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fIwidth\fP\fB, png_uint_32 \fP\fIheight\fP\fB, int \fP\fIbit_depth\fP\fB, int \fP\fIcolor_type\fP\fB, int \fP\fIinterlace_type\fP\fB, int \fP\fIcompression_type\fP\fB, int \fIfilter_type\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_keep_unknown_chunks (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fIkeep\fP\fB, png_bytep \fP\fIchunk_list\fP\fB, int \fInum_chunks\fP\fB);\fP
+\fI\fB
+\fBjmp_buf* png_set_longjmp_fn (png_structp \fP\fIpng_ptr\fP\fB, png_longjmp_ptr \fP\fIlongjmp_fn\fP\fB, size_t \fIjmp_buf_size\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_chunk_malloc_max (png_structp \fP\fIpng_ptr\fP\fB, png_alloc_size_t \fIuser_chunk_cache_max\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_compression_buffer_size (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fIsize\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_mem_fn (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fImem_ptr\fP\fB, png_malloc_ptr \fP\fImalloc_fn\fP\fB, png_free_ptr \fIfree_fn\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_oFFs (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fIoffset_x\fP\fB, png_uint_32 \fP\fIoffset_y\fP\fB, int \fIunit_type\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_packing (png_structp \fIpng_ptr\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_packswap (png_structp \fIpng_ptr\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_palette_to_rgb (png_structp \fIpng_ptr\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_pCAL (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_charp \fP\fIpurpose\fP\fB, png_int_32 \fP\fIX0\fP\fB, png_int_32 \fP\fIX1\fP\fB, int \fP\fItype\fP\fB, int \fP\fInparams\fP\fB, png_charp \fP\fIunits\fP\fB, png_charpp \fIparams\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_pHYs (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fIres_x\fP\fB, png_uint_32 \fP\fIres_y\fP\fB, int \fIunit_type\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_progressive_read_fn (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fIprogressive_ptr\fP\fB, png_progressive_info_ptr \fP\fIinfo_fn\fP\fB, png_progressive_row_ptr \fP\fIrow_fn\fP\fB, png_progressive_end_ptr \fIend_fn\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_PLTE (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_colorp \fP\fIpalette\fP\fB, int \fInum_palette\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_quantize (png_structp \fP\fIpng_ptr\fP\fB, png_colorp \fP\fIpalette\fP\fB, int \fP\fInum_palette\fP\fB, int \fP\fImaximum_colors\fP\fB, png_uint_16p \fP\fIhistogram\fP\fB, int \fIfull_quantize\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_read_fn (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fIio_ptr\fP\fB, png_rw_ptr \fIread_data_fn\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_read_status_fn (png_structp \fP\fIpng_ptr\fP\fB, png_read_status_ptr \fIread_row_fn\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_read_user_chunk_fn (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fIuser_chunk_ptr\fP\fB, png_user_chunk_ptr \fIread_user_chunk_fn\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_read_user_transform_fn (png_structp \fP\fIpng_ptr\fP\fB, png_user_transform_ptr \fIread_user_transform_fn\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_rgb_to_gray (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fIerror_action\fP\fB, double \fP\fIred\fP\fB, double \fIgreen\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_rgb_to_gray_fixed (png_structp \fP\fIpng_ptr\fP\fB, int error_action png_uint_32 \fP\fIred\fP\fB, png_uint_32 \fIgreen\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_rows (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_bytepp \fIrow_pointers\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_sBIT (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_color_8p \fIsig_bit\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_sCAL (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fP\fIunit\fP\fB, double \fP\fIwidth\fP\fB, double \fIheight\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_sCAL_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fP\fIunit\fP\fB, png_fixed_point \fP\fIwidth\fP\fB, png_fixed_point \fIheight\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_sCAL_s (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fP\fIunit\fP\fB, png_charp \fP\fIwidth\fP\fB, png_charp \fIheight\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_scale_16 (png_structp \fIpng_ptr\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_shift (png_structp \fP\fIpng_ptr\fP\fB, png_color_8p \fItrue_bits\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_sig_bytes (png_structp \fP\fIpng_ptr\fP\fB, int \fInum_bytes\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_sPLT (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_spalette_p \fP\fIsplt_ptr\fP\fB, int \fInum_spalettes\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_sRGB (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fIsrgb_intent\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_sRGB_gAMA_and_cHRM (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fIsrgb_intent\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_strip_16 (png_structp \fIpng_ptr\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_strip_alpha (png_structp \fIpng_ptr\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_strip_error_numbers (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fIstrip_mode\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_swap (png_structp \fIpng_ptr\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_swap_alpha (png_structp \fIpng_ptr\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_text (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_textp \fP\fItext_ptr\fP\fB, int \fInum_text\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_text_compression_level (png_structp \fP\fIpng_ptr\fP\fB, int \fIlevel\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_text_compression_mem_level (png_structp \fP\fIpng_ptr\fP\fB, int \fImem_level\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_text_compression_strategy (png_structp \fP\fIpng_ptr\fP\fB, int \fIstrategy\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_text_compression_window_bits (png_structp \fP\fIpng_ptr\fP\fB, int \fIwindow_bits\fP\fB);\fP
+\fI\fB
+\fBvoid \fP\fIpng_set_text_compression_method\fP\fB, (png_structp \fP\fIpng_ptr\fP\fB, int \fImethod)\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_tIME (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_timep \fImod_time\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_tRNS (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_bytep \fP\fItrans_alpha\fP\fB, int \fP\fInum_trans\fP\fB, png_color_16p \fItrans_color\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_tRNS_to_alpha (png_structp \fIpng_ptr\fP\fB);\fP
+\fI\fB
+\fBpng_uint_32 png_set_unknown_chunks (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_unknown_chunkp \fP\fIunknowns\fP\fB, int \fP\fInum\fP\fB, int \fIlocation\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_unknown_chunk_location (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fP\fIchunk\fP\fB, int \fIlocation\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_user_limits (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fP\fIuser_width_max\fP\fB, png_uint_32 \fIuser_height_max\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_user_transform_info (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fIuser_transform_ptr\fP\fB, int \fP\fIuser_transform_depth\fP\fB, int \fIuser_transform_channels\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_write_fn (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fIio_ptr\fP\fB, png_rw_ptr \fP\fIwrite_data_fn\fP\fB, png_flush_ptr \fIoutput_flush_fn\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_write_status_fn (png_structp \fP\fIpng_ptr\fP\fB, png_write_status_ptr \fIwrite_row_fn\fP\fB);\fP
+\fI\fB
+\fBvoid png_set_write_user_transform_fn (png_structp \fP\fIpng_ptr\fP\fB, png_user_transform_ptr \fIwrite_user_transform_fn\fP\fB);\fP
+\fI\fB
+\fBint png_sig_cmp (png_bytep \fP\fIsig\fP\fB, png_size_t \fP\fIstart\fP\fB, png_size_t \fInum_to_check\fP\fB);\fP
+\fI\fB
+\fBvoid png_start_read_image (png_structp \fIpng_ptr\fP\fB);\fP
+\fI\fB
+\fBvoid png_warning (png_structp \fP\fIpng_ptr\fP\fB, png_const_charp \fImessage\fP\fB);\fP
+\fI\fB
+\fBvoid png_write_chunk (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIchunk_name\fP\fB, png_bytep \fP\fIdata\fP\fB, png_size_t \fIlength\fP\fB);\fP
+\fI\fB
+\fBvoid png_write_chunk_data (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIdata\fP\fB, png_size_t \fIlength\fP\fB);\fP
+\fI\fB
+\fBvoid png_write_chunk_end (png_structp \fIpng_ptr\fP\fB);\fP
+\fI\fB
+\fBvoid png_write_chunk_start (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIchunk_name\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
+\fI\fB
+\fBvoid png_write_end (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+\fI\fB
+\fBvoid png_write_flush (png_structp \fIpng_ptr\fP\fB);\fP
+\fI\fB
+\fBvoid png_write_image (png_structp \fP\fIpng_ptr\fP\fB, png_bytepp \fIimage\fP\fB);\fP
+\fI\fB
+\fBvoid png_write_info (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+\fI\fB
+\fBvoid png_write_info_before_PLTE (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+\fI\fB
+\fBvoid png_write_png (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fP\fItransforms\fP\fB, png_voidp \fIparams\fP\fB);\fP
+\fI\fB
+\fBvoid png_write_row (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fIrow\fP\fB);\fP
+\fI\fB
+\fBvoid png_write_rows (png_structp \fP\fIpng_ptr\fP\fB, png_bytepp \fP\fIrow\fP\fB, png_uint_32 \fInum_rows\fP\fB);\fP
+\fI\fB
+\fBvoid png_write_sig (png_structp \fIpng_ptr\fP\fB);\fP
+\fI\fB
+\fBvoidpf png_zalloc (voidpf \fP\fIpng_ptr\fP\fB, uInt \fP\fIitems\fP\fB, uInt \fIsize\fP\fB);\fP
+\fI\fB
+\fBvoid png_zfree (voidpf \fP\fIpng_ptr\fP\fB, voidpf \fIptr\fP\fB);\fP
+\fI\fB
+.SH DESCRIPTION
+The
+.I libpng
+library supports encoding, decoding, and various manipulations of
+the Portable Network Graphics (PNG) format image files.  It uses the
+.IR zlib(3)
+compression library.
+Following is a copy of the libpng-manual.txt file that accompanies libpng.
+.SH LIBPNG.TXT
+libpng-manual.txt - A description on how to use and modify libpng
+ libpng version 1.5.9 - February 18, 2012
+ Updated and distributed by Glenn Randers-Pehrson
+ <glennrp at users.sourceforge.net>
+ Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ This document is released under the libpng license.
+ For conditions of distribution and use, see the disclaimer
+ and license in png.h
+ Based on:
+ libpng versions 0.97, January 1998, through 1.5.9 - February 18, 2012
+ Updated and distributed by Glenn Randers-Pehrson
+ Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ libpng 1.0 beta 6  version 0.96 May 28, 1997
+ Updated and distributed by Andreas Dilger
+ Copyright (c) 1996, 1997 Andreas Dilger
+ libpng 1.0 beta 2 - version 0.88  January 26, 1996
+ For conditions of distribution and use, see copyright
+ notice in png.h. Copyright (c) 1995, 1996 Guy Eric
+ Schalnat, Group 42, Inc.
+ Updated/rewritten per request in the libpng FAQ
+ Copyright (c) 1995, 1996 Frank J. T. Wojcik
+ December 18, 1995 & January 20, 1996
+.SH I. Introduction
+This file describes how to use and modify the PNG reference library
+(known as libpng) for your own use.  There are five sections to this
+file: introduction, structures, reading, writing, and modification and
+configuration notes for various special platforms.  In addition to this
+file, example.c is a good starting point for using the library, as
+it is heavily commented and should include everything most people
+will need.  We assume that libpng is already installed; see the
+INSTALL file for instructions on how to install libpng.
+For examples of libpng usage, see the files "example.c", "pngtest.c",
+and the files in the "contrib" directory, all of which are included in
+the libpng distribution.
+Libpng was written as a companion to the PNG specification, as a way
+of reducing the amount of time and effort it takes to support the PNG
+file format in application programs.
+The PNG specification (second edition), November 2003, is available as
+a W3C Recommendation and as an ISO Standard (ISO/IEC 15948:2003 (E)) at
+<http://www.w3.org/TR/2003/REC-PNG-20031110/
+The W3C and ISO documents have identical technical content.
+The PNG-1.2 specification is available at
+<http://www.libpng.org/pub/png/documents/>.  It is technically equivalent
+to the PNG specification (second edition) but has some additional material.
+The PNG-1.0 specification is available
+as RFC 2083 <http://www.libpng.org/pub/png/documents/> and as a
+W3C Recommendation <http://www.w3.org/TR/REC.png.html>.
+Some additional chunks are described in the special-purpose public chunks
+documents at <http://www.libpng.org/pub/png/documents/>.
+Other information
+about PNG, and the latest version of libpng, can be found at the PNG home
+page, <http://www.libpng.org/pub/png/>.
+Most users will not have to modify the library significantly; advanced
+users may want to modify it more.  All attempts were made to make it as
+complete as possible, while keeping the code easy to understand.
+Currently, this library only supports C.  Support for other languages
+is being considered.
+Libpng has been designed to handle multiple sessions at one time,
+to be easily modifiable, to be portable to the vast majority of
+machines (ANSI, K&R, 16-, 32-, and 64-bit) available, and to be easy
+to use.  The ultimate goal of libpng is to promote the acceptance of
+the PNG file format in whatever way possible.  While there is still
+work to be done (see the TODO file), libpng should cover the
+majority of the needs of its users.
+Libpng uses zlib for its compression and decompression of PNG files.
+Further information about zlib, and the latest version of zlib, can
+be found at the zlib home page, <http://www.info-zip.org/pub/infozip/zlib/>.
+The zlib compression utility is a general purpose utility that is
+useful for more than PNG files, and can be used without libpng.
+See the documentation delivered with zlib for more details.
+You can usually find the source files for the zlib utility wherever you
+find the libpng source files.
+Libpng is thread safe, provided the threads are using different
+instances of the structures.  Each thread should have its own
+png_struct and png_info instances, and thus its own image.
+Libpng does not protect itself against two threads using the
+same instance of a structure.
+.SH II. Structures
+There are two main structures that are important to libpng, png_struct
+and png_info.  Both are internal structures that are no longer exposed
+in the libpng interface (as of libpng 1.5.0).
+The png_info structure is designed to provide information about the
+PNG file.  At one time, the fields of png_info were intended to be
+directly accessible to the user.  However, this tended to cause problems
+with applications using dynamically loaded libraries, and as a result
+a set of interface functions for png_info (the png_get_*() and png_set_*()
+functions) was developed, and direct access to the png_info fields was
+deprecated..
+The png_struct structure is the object used by the library to decode a
+single image.  As of 1.5.0 this structure is also not exposed.
+Almost all libpng APIs require a pointer to a png_struct as the first argument.
+Many (in particular the png_set and png_get APIs) also require a pointer
+to png_info as the second argument.  Some application visible macros
+defined in png.h designed for basic data access (reading and writing
+integers in the PNG format) don't take a png_info pointer, but it's almost
+always safe to assume that a (png_struct*) has to be passed to call an API
+function.
+You can have more than one png_info structure associated with an image,
+as illustrated in pngtest.c, one for information valid prior to the
+IDAT chunks and another (called "end_info" below) for things after them.
+The png.h header file is an invaluable reference for programming with libpng.
+And while I'm on the topic, make sure you include the libpng header file:
+#include <png.h>
+and also (as of libpng-1.5.0) the zlib header file, if you need it:
+#include <zlib.h>
+.SS Types
+The png.h header file defines a number of integral types used by the
+APIs.  Most of these are fairly obvious; for example types corresponding
+to integers of particular sizes and types for passing color values.
+One exception is how non-integral numbers are handled.  For application
+convenience most APIs that take such numbers have C (double) arguments,
+however internally PNG, and libpng, use 32 bit signed integers and encode
+the value by multiplying by 100,000.  As of libpng 1.5.0 a convenience
+macro PNG_FP_1 is defined in png.h along with a type (png_fixed_point)
+which is simply (png_int_32).
+All APIs that take (double) arguments also have a matching API that
+takes the corresponding fixed point integer arguments.  The fixed point
+API has the same name as the floating point one with "_fixed" appended.
+The actual range of values permitted in the APIs is frequently less than
+the full range of (png_fixed_point) (-21474 to +21474).  When APIs require
+a non-negative argument the type is recorded as png_uint_32 above.  Consult
+the header file and the text below for more information.
+Special care must be take with sCAL chunk handling because the chunk itself
+uses non-integral values encoded as strings containing decimal floating point
+numbers.  See the comments in the header file.
+.SS Configuration
+The main header file function declarations are frequently protected by C
+preprocessing directives of the form:
+    #ifdef PNG_feature_SUPPORTED
+    declare-function
+    #endif
+    ...
+    #ifdef PNG_feature_SUPPORTED
+    use-function
+    #endif
+The library can be built without support for these APIs, although a
+standard build will have all implemented APIs.  Application programs
+should check the feature macros before using an API for maximum
+portability.  From libpng 1.5.0 the feature macros set during the build
+of libpng are recorded in the header file "pnglibconf.h" and this file
+is always included by png.h.
+If you don't need to change the library configuration from the default, skip to
+the next section ("Reading").
+Notice that some of the makefiles in the 'scripts' directory and (in 1.5.0) all
+of the build project files in the 'projects' directory simply copy
+scripts/pnglibconf.h.prebuilt to pnglibconf.h.  This means that these build
+systems do not permit easy auto-configuration of the library - they only
+support the default configuration.
+The easiest way to make minor changes to the libpng configuration when
+auto-configuration is supported is to add definitions to the command line
+using (typically) CPPFLAGS.  For example:
+CPPFLAGS=-DPNG_NO_FLOATING_ARITHMETIC
+will change the internal libpng math implementation for gamma correction and
+other arithmetic calculations to fixed point, avoiding the need for fast
+floating point support.  The result can be seen in the generated pnglibconf.h -
+make sure it contains the changed feature macro setting.
+If you need to make more extensive configuration changes - more than one or two
+feature macro settings - you can either add -DPNG_USER_CONFIG to the build
+command line and put a list of feature macro settings in pngusr.h or you can set
+DFA_XTRA (a makefile variable) to a file containing the same information in the
+form of 'option' settings.
+A. Changing pnglibconf.h
+A variety of methods exist to build libpng.  Not all of these support
+reconfiguration of pnglibconf.h.  To reconfigure pnglibconf.h it must either be
+rebuilt from scripts/pnglibconf.dfa using awk or it must be edited by hand.
+Hand editing is achieved by copying scripts/pnglibconf.h.prebuilt to
+pnglibconf.h and changing the lines defining the supported features, paying
+very close attention to the 'option' information in scripts/pnglibconf.dfa
+that describes those features and their requirements.  This is easy to get
+wrong.
+B. Configuration using DFA_XTRA
+Rebuilding from pnglibconf.dfa is easy if a functioning 'awk', or a later
+variant such as 'nawk' or 'gawk', is available.  The configure build will
+automatically find an appropriate awk and build pnglibconf.h.
+The scripts/pnglibconf.mak file contains a set of make rules for doing the
+same thing if configure is not used, and many of the makefiles in the scripts
+directory use this approach.
+When rebuilding simply write a new file containing changed options and set
+DFA_XTRA to the name of this file.  This causes the build to append the new file
+to the end of scripts/pnglibconf.dfa.  The pngusr.dfa file should contain lines
+of the following forms:
+everything = off
+This turns all optional features off.  Include it at the start of pngusr.dfa to
+make it easier to build a minimal configuration.  You will need to turn at least
+some features on afterward to enable either reading or writing code, or both.
+option feature on
+option feature off
+Enable or disable a single feature.  This will automatically enable other
+features required by a feature that is turned on or disable other features that
+require a feature which is turned off.  Conflicting settings will cause an error
+message to be emitted by awk.
+setting feature default value
+Changes the default value of setting 'feature' to 'value'.  There are a small
+number of settings listed at the top of pnglibconf.h, they are documented in the
+source code.  Most of these values have performance implications for the library
+but most of them have no visible effect on the API.  Some can also be overridden
+from the API.
+This method of building a customized pnglibconf.h is illustrated in
+contrib/pngminim/*.  See the "$(PNGCONF):" target in the makefile and
+pngusr.dfa in these directories.
+C. Configuration using PNG_USR_CONFIG
+If -DPNG_USR_CONFIG is added to the CFLAGS when pnglibconf.h is built the file
+pngusr.h will automatically be included before the options in
+scripts/pnglibconf.dfa are processed.  Your pngusr.h file should contain only
+macro definitions turning features on or off or setting settings.
+Apart from the global setting "everything = off" all the options listed above
+can be set using macros in pngusr.h:
+#define PNG_feature_SUPPORTED
+is equivalent to:
+option feature on
+#define PNG_NO_feature
+is equivalent to:
+option feature off
+#define PNG_feature value
+is equivalent to:
+setting feature default value
+Notice that in both cases, pngusr.dfa and pngusr.h, the contents of the
+pngusr file you supply override the contents of scripts/pnglibconf.dfa
+If confusing or incomprehensible behavior results it is possible to
+examine the intermediate file pnglibconf.dfn to find the full set of
+dependency information for each setting and option.  Simply locate the
+feature in the file and read the C comments that precede it.
+This method is also illustrated in the contrib/pngminim/* makefiles and
+pngusr.h.
+.SH III. Reading
+We'll now walk you through the possible functions to call when reading
+in a PNG file sequentially, briefly explaining the syntax and purpose
+of each one.  See example.c and png.h for more detail.  While
+progressive reading is covered in the next section, you will still
+need some of the functions discussed in this section to read a PNG
+file.
+.SS Setup
+You will want to do the I/O initialization(*) before you get into libpng,
+so if it doesn't work, you don't have much to undo.  Of course, you
+will also want to insure that you are, in fact, dealing with a PNG
+file.  Libpng provides a simple check to see if a file is a PNG file.
+To use it, pass in the first 1 to 8 bytes of the file to the function
+png_sig_cmp(), and it will return 0 (false) if the bytes match the
+corresponding bytes of the PNG signature, or nonzero (true) otherwise.
+Of course, the more bytes you pass in, the greater the accuracy of the
+prediction.
+If you are intending to keep the file pointer open for use in libpng,
+you must ensure you don't read more than 8 bytes from the beginning
+of the file, and you also have to make a call to png_set_sig_bytes_read()
+with the number of bytes you read from the beginning.  Libpng will
+then only check the bytes (if any) that your program didn't read.
+(*): If you are not using the standard I/O functions, you will need
+to replace them with custom functions.  See the discussion under
+Customizing libpng.
+    FILE *fp = fopen(file_name, "rb");
+    if (!fp)
+    {
+       return (ERROR);
+    }
+    fread(header, 1, number, fp);
+    is_png = !png_sig_cmp(header, 0, number);
+    if (!is_png)
+    {
+       return (NOT_PNG);
+    }
+Next, png_struct and png_info need to be allocated and initialized.  In
+order to ensure that the size of these structures is correct even with a
+dynamically linked libpng, there are functions to initialize and
+allocate the structures.  We also pass the library version, optional
+pointers to error handling functions, and a pointer to a data struct for
+use by the error functions, if necessary (the pointer and functions can
+be NULL if the default error handlers are to be used).  See the section
+on Changes to Libpng below regarding the old initialization functions.
+The structure allocation functions quietly return NULL if they fail to
+create the structure, so your application should check for that.
+    png_structp png_ptr = png_create_read_struct
+        (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
+        user_error_fn, user_warning_fn);
+    if (!png_ptr)
+       return (ERROR);
+    png_infop info_ptr = png_create_info_struct(png_ptr);
+    if (!info_ptr)
+    {
+       png_destroy_read_struct(&png_ptr,
+           (png_infopp)NULL, (png_infopp)NULL);
+       return (ERROR);
+    }
+If you want to use your own memory allocation routines,
+use a libpng that was built with PNG_USER_MEM_SUPPORTED defined, and use
+png_create_read_struct_2() instead of png_create_read_struct():
+    png_structp png_ptr = png_create_read_struct_2
+        (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
+        user_error_fn, user_warning_fn, (png_voidp)
+        user_mem_ptr, user_malloc_fn, user_free_fn);
+The error handling routines passed to png_create_read_struct()
+and the memory alloc/free routines passed to png_create_struct_2()
+are only necessary if you are not using the libpng supplied error
+handling and memory alloc/free functions.
+When libpng encounters an error, it expects to longjmp back
+to your routine.  Therefore, you will need to call setjmp and pass
+your png_jmpbuf(png_ptr).  If you read the file from different
+routines, you will need to update the longjmp buffer every time you enter
+a new routine that will call a png_*() function.
+See your documentation of setjmp/longjmp for your compiler for more
+information on setjmp/longjmp.  See the discussion on libpng error
+handling in the Customizing Libpng section below for more information
+on the libpng error handling.  If an error occurs, and libpng longjmp's
+back to your setjmp, you will want to call png_destroy_read_struct() to
+free any memory.
+    if (setjmp(png_jmpbuf(png_ptr)))
+    {
+       png_destroy_read_struct(&png_ptr, &info_ptr,
+           &end_info);
+       fclose(fp);
+       return (ERROR);
+    }
+Pass (png_infopp)NULL instead of &end_info if you didn't create
+an end_info structure.
+If you would rather avoid the complexity of setjmp/longjmp issues,
+you can compile libpng with PNG_NO_SETJMP, in which case
+errors will result in a call to PNG_ABORT() which defaults to abort().
+You can #define PNG_ABORT() to a function that does something
+more useful than abort(), as long as your function does not
+return.
+Now you need to set up the input code.  The default for libpng is to
+use the C function fread().  If you use this, you will need to pass a
+valid FILE * in the function png_init_io().  Be sure that the file is
+opened in binary mode.  If you wish to handle reading data in another
+way, you need not call the png_init_io() function, but you must then
+implement the libpng I/O methods discussed in the Customizing Libpng
+section below.
+    png_init_io(png_ptr, fp);
+If you had previously opened the file and read any of the signature from
+the beginning in order to see if this was a PNG file, you need to let
+libpng know that there are some bytes missing from the start of the file.
+    png_set_sig_bytes(png_ptr, number);
+You can change the zlib compression buffer size to be used while
+reading compressed data with
+    png_set_compression_buffer_size(png_ptr, buffer_size);
+where the default size is 8192 bytes.  Note that the buffer size
+is changed immediately and the buffer is reallocated immediately,
+instead of setting a flag to be acted upon later.
+If you want CRC errors to be handled in a different manner than
+the default, use
+    png_set_crc_action(png_ptr, crit_action, ancil_action);
+The values for png_set_crc_action() say how libpng is to handle CRC errors in
+ancillary and critical chunks, and whether to use the data contained
+therein.  Note that it is impossible to "discard" data in a critical
+chunk.
+Choices for (int) crit_action are
+   PNG_CRC_DEFAULT      0  error/quit
+   PNG_CRC_ERROR_QUIT   1  error/quit
+   PNG_CRC_WARN_USE     3  warn/use data
+   PNG_CRC_QUIET_USE    4  quiet/use data
+   PNG_CRC_NO_CHANGE    5  use the current value
+Choices for (int) ancil_action are
+   PNG_CRC_DEFAULT      0  error/quit
+   PNG_CRC_ERROR_QUIT   1  error/quit
+   PNG_CRC_WARN_DISCARD 2  warn/discard data
+   PNG_CRC_WARN_USE     3  warn/use data
+   PNG_CRC_QUIET_USE    4  quiet/use data
+   PNG_CRC_NO_CHANGE    5  use the current value
+.SS Setting up callback code
+You can set up a callback function to handle any unknown chunks in the
+input stream. You must supply the function
+    read_chunk_callback(png_structp png_ptr,
+         png_unknown_chunkp chunk);
+    {
+       /* The unknown chunk structure contains your
+          chunk data, along with similar data for any other
+          unknown chunks: */
+           png_byte name[5];
+           png_byte *data;
+           png_size_t size;
+       /* Note that libpng has already taken care of
+          the CRC handling */
+       /* put your code here.  Search for your chunk in the
+          unknown chunk structure, process it, and return one
+          of the following: */
+       return (-n); /* chunk had an error */
+       return (0); /* did not recognize */
+       return (n); /* success */
+    }
+(You can give your function another name that you like instead of
+"read_chunk_callback")
+To inform libpng about your function, use
+    png_set_read_user_chunk_fn(png_ptr, user_chunk_ptr,
+        read_chunk_callback);
+This names not only the callback function, but also a user pointer that
+you can retrieve with
+    png_get_user_chunk_ptr(png_ptr);
+If you call the png_set_read_user_chunk_fn() function, then all unknown
+chunks will be saved when read, in case your callback function will need
+one or more of them.  This behavior can be changed with the
+png_set_keep_unknown_chunks() function, described below.
+At this point, you can set up a callback function that will be
+called after each row has been read, which you can use to control
+a progress meter or the like.  It's demonstrated in pngtest.c.
+You must supply a function
+    void read_row_callback(png_structp png_ptr,
+       png_uint_32 row, int pass);
+    {
+      /* put your code here */
+    }
+(You can give it another name that you like instead of "read_row_callback")
+To inform libpng about your function, use
+    png_set_read_status_fn(png_ptr, read_row_callback);
+When this function is called the row has already been completely processed and
+the 'row' and 'pass' refer to the next row to be handled.  For the
+non-interlaced case the row that was just handled is simply one less than the
+passed in row number, and pass will always be 0.  For the interlaced case the
+same applies unless the row value is 0, in which case the row just handled was
+the last one from one of the preceding passes.  Because interlacing may skip a
+pass you cannot be sure that the preceding pass is just 'pass-1', if you really
+need to know what the last pass is record (row,pass) from the callback and use
+the last recorded value each time.
+As with the user transform you can find the output row using the
+PNG_ROW_FROM_PASS_ROW macro.
+.SS Unknown-chunk handling
+Now you get to set the way the library processes unknown chunks in the
+input PNG stream. Both known and unknown chunks will be read.  Normal
+behavior is that known chunks will be parsed into information in
+various info_ptr members while unknown chunks will be discarded. This
+behavior can be wasteful if your application will never use some known
+chunk types. To change this, you can call:
+    png_set_keep_unknown_chunks(png_ptr, keep,
+        chunk_list, num_chunks);
+    keep       - 0: default unknown chunk handling
+                 1: ignore; do not keep
+                 2: keep only if safe-to-copy
+                 3: keep even if unsafe-to-copy
+               You can use these definitions:
+                 PNG_HANDLE_CHUNK_AS_DEFAULT   0
+                 PNG_HANDLE_CHUNK_NEVER        1
+                 PNG_HANDLE_CHUNK_IF_SAFE      2
+                 PNG_HANDLE_CHUNK_ALWAYS       3
+    chunk_list - list of chunks affected (a byte string,
+                 five bytes per chunk, NULL or '\0' if
+                 num_chunks is 0)
+    num_chunks - number of chunks affected; if 0, all
+                 unknown chunks are affected.  If nonzero,
+                 only the chunks in the list are affected
+Unknown chunks declared in this way will be saved as raw data onto a
+list of png_unknown_chunk structures.  If a chunk that is normally
+known to libpng is named in the list, it will be handled as unknown,
+according to the "keep" directive.  If a chunk is named in successive
+instances of png_set_keep_unknown_chunks(), the final instance will
+take precedence.  The IHDR and IEND chunks should not be named in
+chunk_list; if they are, libpng will process them normally anyway.
+If you know that your application will never make use of some particular
+chunks, use PNG_HANDLE_CHUNK_NEVER (or 1) as demonstrated below.
+Here is an example of the usage of png_set_keep_unknown_chunks(),
+where the private "vpAg" chunk will later be processed by a user chunk
+callback function:
+    png_byte vpAg[5]={118, 112,  65, 103, (png_byte) '\0'};
+    #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
+      png_byte unused_chunks[]=
+      {
+        104,  73,  83,  84, (png_byte) '\0',   /* hIST */
+        105,  84,  88, 116, (png_byte) '\0',   /* iTXt */
+        112,  67,  65,  76, (png_byte) '\0',   /* pCAL */
+        115,  67,  65,  76, (png_byte) '\0',   /* sCAL */
+        115,  80,  76,  84, (png_byte) '\0',   /* sPLT */
+        116,  73,  77,  69, (png_byte) '\0',   /* tIME */
+      };
+    #endif
+    ...
+    #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
+      /* ignore all unknown chunks: */
+      png_set_keep_unknown_chunks(read_ptr, 1, NULL, 0);
+      /* except for vpAg: */
+      png_set_keep_unknown_chunks(read_ptr, 2, vpAg, 1);
+      /* also ignore unused known chunks: */
+      png_set_keep_unknown_chunks(read_ptr, 1, unused_chunks,
+         (int)sizeof(unused_chunks)/5);
+    #endif
+.SS User limits
+The PNG specification allows the width and height of an image to be as
+large as 2^31-1 (0x7fffffff), or about 2.147 billion rows and columns.
+Since very few applications really need to process such large images,
+we have imposed an arbitrary 1-million limit on rows and columns.
+Larger images will be rejected immediately with a png_error() call. If
+you wish to change this limit, you can use
+   png_set_user_limits(png_ptr, width_max, height_max);
+to set your own limits, or use width_max = height_max = 0x7fffffffL
+to allow all valid dimensions (libpng may reject some very large images
+anyway because of potential buffer overflow conditions).
+You should put this statement after you create the PNG structure and
+before calling png_read_info(), png_read_png(), or png_process_data().
+When writing a PNG datastream, put this statement before calling
+png_write_info() or png_write_png().
+If you need to retrieve the limits that are being applied, use
+   width_max = png_get_user_width_max(png_ptr);
+   height_max = png_get_user_height_max(png_ptr);
+The PNG specification sets no limit on the number of ancillary chunks
+allowed in a PNG datastream.  You can impose a limit on the total number
+of sPLT, tEXt, iTXt, zTXt, and unknown chunks that will be stored, with
+   png_set_chunk_cache_max(png_ptr, user_chunk_cache_max);
+where 0x7fffffffL means unlimited.  You can retrieve this limit with
+   chunk_cache_max = png_get_chunk_cache_max(png_ptr);
+This limit also applies to the number of buffers that can be allocated
+by png_decompress_chunk() while decompressing iTXt, zTXt, and iCCP chunks.
+You can also set a limit on the amount of memory that a compressed chunk
+other than IDAT can occupy, with
+   png_set_chunk_malloc_max(png_ptr, user_chunk_malloc_max);
+and you can retrieve the limit with
+   chunk_malloc_max = png_get_chunk_malloc_max(png_ptr);
+Any chunks that would cause either of these limits to be exceeded will
+be ignored.
+.SS Information about your system
+If you intend to display the PNG or to incorporate it in other image data you
+need to tell libpng information about your display or drawing surface so that
+libpng can convert the values in the image to match the display.
+From libpng-1.5.4 this information can be set before reading the PNG file
+header.  In earlier versions png_set_gamma() existed but behaved incorrectly if
+called before the PNG file header had been read and png_set_alpha_mode() did not
+exist.
+If you need to support versions prior to libpng-1.5.4 test the version number
+as illustrated below using "PNG_LIBPNG_VER >= 10504" and follow the procedures
+described in the appropriate manual page.
+You give libpng the encoding expected by your system expressed as a 'gamma'
+value.  You can also specify a default encoding for the PNG file in
+case the required information is missing from the file.  By default libpng
+assumes that the PNG data matches your system, to keep this default call:
+   png_set_gamma(png_ptr, screen_gamma, 1/screen_gamma/*file gamma*/);
+or you can use the fixed point equivalent:
+   png_set_gamma_fixed(png_ptr, PNG_FP_1*screen_gamma, PNG_FP_1/screen_gamma);
+If you don't know the gamma for your system it is probably 2.2 - a good
+approximation to the IEC standard for display systems (sRGB).  If images are
+too contrasty or washed out you got the value wrong - check your system
+documentation!
+Many systems permit the system gamma to be changed via a lookup table in the
+display driver, a few systems, including older Macs, change the response by
+default.  As of 1.5.4 three special values are available to handle common
+situations:
+   PNG_DEFAULT_sRGB: Indicates that the system conforms to the IEC 61966-2-1
+                     standard.  This matches almost all systems.
+   PNG_GAMMA_MAC_18: Indicates that the system is an older (pre Mac OS 10.6)
+                     Apple Macintosh system with the default settings.
+   PNG_GAMMA_LINEAR: Just the fixed point value for 1.0 - indicates that the
+                     system expects data with no gamma encoding.
+You would use the linear (unencoded) value if you need to process the pixel
+values further because this avoids the need to decode and reencode each
+component value whenever arithmetic is performed.  A lot of graphics software
+uses linear values for this reason, often with higher precision component values
+to preserve overall accuracy.
+The second thing you may need to tell libpng about is how your system handles
+alpha channel information.  Some, but not all, PNG files contain an alpha
+channel.  To display these files correctly you need to compose the data onto a
+suitable background, as described in the PNG specification.
+Libpng only supports composing onto a single color (using png_set_background;
+see below).  Otherwise you must do the composition yourself and, in this case,
+you may need to call png_set_alpha_mode:
+#if PNG_LIBPNG_VER >= 10504
+   png_set_alpha_mode(png_ptr, mode, screen_gamma);
+#else
+   png_set_gamma(png_ptr, screen_gamma, 1.0/screen_gamma);
+#endif
+The screen_gamma value is the same as the argument to png_set_gamma; however,
+how it affects the output depends on the mode.  png_set_alpha_mode() sets the
+file gamma default to 1/screen_gamma, so normally you don't need to call
+png_set_gamma.  If you need different defaults call png_set_gamma() before
+png_set_alpha_mode() - if you call it after it will override the settings made
+by png_set_alpha_mode().
+The mode is as follows:
+    PNG_ALPHA_PNG: The data is encoded according to the PNG specification.  Red,
+green and blue, or gray, components are gamma encoded color
+values and are not premultiplied by the alpha value.  The
+alpha value is a linear measure of the contribution of the
+pixel to the corresponding final output pixel.
+You should normally use this format if you intend to perform
+color correction on the color values; most, maybe all, color
+correction software has no handling for the alpha channel and,
+anyway, the math to handle pre-multiplied component values is
+unnecessarily complex.
+Before you do any arithmetic on the component values you need
+to remove the gamma encoding and multiply out the alpha
+channel.  See the PNG specification for more detail.  It is
+important to note that when an image with an alpha channel is
+scaled, linear encoded, pre-multiplied component values must
+be used!
+The remaining modes assume you don't need to do any further color correction or
+that if you do, your color correction software knows all about alpha (it
+probably doesn't!)
+    PNG_ALPHA_STANDARD:  The data libpng produces
+is encoded in the standard way
+assumed by most correctly written graphics software.
+The gamma encoding will be removed by libpng and the
+linear component values will be pre-multiplied by the
+alpha channel.
+With this format the final image must be re-encoded to
+match the display gamma before the image is displayed.
+If your system doesn't do that, yet still seems to
+perform arithmetic on the pixels without decoding them,
+it is broken - check out the modes below.
+With PNG_ALPHA_STANDARD libpng always produces linear
+component values, whatever screen_gamma you supply.  The
+screen_gamma value is, however, used as a default for
+the file gamma if the PNG file has no gamma information.
+If you call png_set_gamma() after png_set_alpha_mode() you
+will override the linear encoding.  Instead the
+pre-multiplied pixel values will be gamma encoded but
+the alpha channel will still be linear.  This may
+actually match the requirements of some broken software,
+but it is unlikely.
+While linear 8-bit data is often used it has
+insufficient precision for any image with a reasonable
+dynamic range.  To avoid problems, and if your software
+supports it, use png_set_expand_16() to force all
+components to 16 bits.
+    PNG_ALPHA_OPTIMIZED: This mode is the same
+as PNG_ALPHA_STANDARD except that
+completely opaque pixels are gamma encoded according to
+the screen_gamma value.  Pixels with alpha less than 1.0
+will still have linear components.
+Use this format if you have control over your
+compositing software and do don't do other arithmetic
+(such as scaling) on the data you get from libpng.  Your
+compositing software can simply copy opaque pixels to
+the output but still has linear values for the
+non-opaque pixels.
+In normal compositing, where the alpha channel encodes
+partial pixel coverage (as opposed to broad area
+translucency), the inaccuracies of the 8-bit
+representation of non-opaque pixels are irrelevant.
+You can also try this format if your software is broken;
+it might look better.
+    PNG_ALPHA_BROKEN: This is PNG_ALPHA_STANDARD;
+however, all component values,
+including the alpha channel are gamma encoded.  This is
+an appropriate format to try if your software, or more
+likely hardware, is totally broken, i.e., if it performs
+linear arithmetic directly on gamma encoded values.
+In most cases of broken software or hardware the bug in the final display
+manifests as a subtle halo around composited parts of the image.  You may not
+even perceive this as a halo; the composited part of the image may simply appear
+separate from the background, as though it had been cut out of paper and pasted
+on afterward.
+If you don't have to deal with bugs in software or hardware, or if you can fix
+them, there are three recommended ways of using png_set_alpha_mode():
+   png_set_alpha_mode(png_ptr, PNG_ALPHA_PNG,
+       screen_gamma);
+You can do color correction on the result (libpng does not currently
+support color correction internally).  When you handle the alpha channel
+you need to undo the gamma encoding and multiply out the alpha.
+   png_set_alpha_mode(png_ptr, PNG_ALPHA_STANDARD,
+       screen_gamma);
+   png_set_expand_16(png_ptr);
+If you are using the high level interface, don't call png_set_expand_16();
+instead pass PNG_TRANSFORM_EXPAND_16 to the interface.
+With this mode you can't do color correction, but you can do arithmetic,
+including composition and scaling, on the data without further processing.
+   png_set_alpha_mode(png_ptr, PNG_ALPHA_OPTIMIZED,
+       screen_gamma);
+You can avoid the expansion to 16-bit components with this mode, but you
+lose the ability to scale the image or perform other linear arithmetic.
+All you can do is compose the result onto a matching output.  Since this
+mode is libpng-specific you also need to write your own composition
+software.
+If you don't need, or can't handle, the alpha channel you can call
+png_set_background() to remove it by compositing against a fixed color.  Don't
+call png_set_strip_alpha() to do this - it will leave spurious pixel values in
+transparent parts of this image.
+   png_set_background(png_ptr, &background_color,
+       PNG_BACKGROUND_GAMMA_SCREEN, 0, 1);
+The background_color is an RGB or grayscale value according to the data format
+libpng will produce for you.  Because you don't yet know the format of the PNG
+file, if you call png_set_background at this point you must arrange for the
+format produced by libpng to always have 8-bit or 16-bit components and then
+store the color as an 8-bit or 16-bit color as appropriate.  The color contains
+separate gray and RGB component values, so you can let libpng produce gray or
+RGB output according to the input format, but low bit depth grayscale images
+must always be converted to at least 8-bit format.  (Even though low bit depth
+grayscale images can't have an alpha channel they can have a transparent
+color!)
+You set the transforms you need later, either as flags to the high level
+interface or libpng API calls for the low level interface.  For reference the
+settings and API calls required are:
+8-bit values:
+   PNG_TRANSFORM_SCALE_16 | PNG_EXPAND
+   png_set_expand(png_ptr); png_set_scale_16(png_ptr);
+   If you must get exactly the same inaccurate results
+   produced by default in versions prior to libpng-1.5.4,
+   use PNG_TRANSFORM_STRIP_16 and png_set_strip_16(png_ptr)
+   instead.
+16-bit values:
+   PNG_TRANSFORM_EXPAND_16
+   png_set_expand_16(png_ptr);
+In either case palette image data will be expanded to RGB.  If you just want
+color data you can add PNG_TRANSFORM_GRAY_TO_RGB or png_set_gray_to_rgb(png_ptr)
+to the list.
+Calling png_set_background before the PNG file header is read will not work
+prior to libpng-1.5.4.  Because the failure may result in unexpected warnings or
+errors it is therefore much safer to call png_set_background after the head has
+been read.  Unfortunately this means that prior to libpng-1.5.4 it cannot be
+used with the high level interface.
+.SS The high-level read interface
+At this point there are two ways to proceed; through the high-level
+read interface, or through a sequence of low-level read operations.
+You can use the high-level interface if (a) you are willing to read
+the entire image into memory, and (b) the input transformations
+you want to do are limited to the following set:
+    PNG_TRANSFORM_IDENTITY      No transformation
+    PNG_TRANSFORM_SCALE_16      Strip 16-bit samples to
+                                8-bit accurately
+    PNG_TRANSFORM_STRIP_16      Chop 16-bit samples to
+                                8-bit less accurately
+    PNG_TRANSFORM_STRIP_ALPHA   Discard the alpha channel
+    PNG_TRANSFORM_PACKING       Expand 1, 2 and 4-bit
+                                samples to bytes
+    PNG_TRANSFORM_PACKSWAP      Change order of packed
+                                pixels to LSB first
+    PNG_TRANSFORM_EXPAND        Perform set_expand()
+    PNG_TRANSFORM_INVERT_MONO   Invert monochrome images
+    PNG_TRANSFORM_SHIFT         Normalize pixels to the
+                                sBIT depth
+    PNG_TRANSFORM_BGR           Flip RGB to BGR, RGBA
+                                to BGRA
+    PNG_TRANSFORM_SWAP_ALPHA    Flip RGBA to ARGB or GA
+                                to AG
+    PNG_TRANSFORM_INVERT_ALPHA  Change alpha from opacity
+                                to transparency
+    PNG_TRANSFORM_SWAP_ENDIAN   Byte-swap 16-bit samples
+    PNG_TRANSFORM_GRAY_TO_RGB   Expand grayscale samples
+                                to RGB (or GA to RGBA)
+    PNG_TRANSFORM_EXPAND_16     Expand samples to 16 bits
+(This excludes setting a background color, doing gamma transformation,
+quantizing, and setting filler.)  If this is the case, simply do this:
+    png_read_png(png_ptr, info_ptr, png_transforms, NULL)
+where png_transforms is an integer containing the bitwise OR of some
+set of transformation flags.  This call is equivalent to png_read_info(),
+followed the set of transformations indicated by the transform mask,
+then png_read_image(), and finally png_read_end().
+(The final parameter of this call is not yet used.  Someday it might point
+to transformation parameters required by some future input transform.)
+You must use png_transforms and not call any png_set_transform() functions
+when you use png_read_png().
+After you have called png_read_png(), you can retrieve the image data
+with
+   row_pointers = png_get_rows(png_ptr, info_ptr);
+where row_pointers is an array of pointers to the pixel data for each row:
+   png_bytep row_pointers[height];
+If you know your image size and pixel size ahead of time, you can allocate
+row_pointers prior to calling png_read_png() with
+   if (height > PNG_UINT_32_MAX/png_sizeof(png_byte))
+      png_error (png_ptr,
+          "Image is too tall to process in memory");
+   if (width > PNG_UINT_32_MAX/pixel_size)
+      png_error (png_ptr,
+          "Image is too wide to process in memory");
+   row_pointers = png_malloc(png_ptr,
+       height*png_sizeof(png_bytep));
+   for (int i=0; i<height, i++)
+      row_pointers[i]=NULL;  /* security precaution */
+   for (int i=0; i<height, i++)
+      row_pointers[i]=png_malloc(png_ptr,
+          width*pixel_size);
+   png_set_rows(png_ptr, info_ptr, &row_pointers);
+Alternatively you could allocate your image in one big block and define
+row_pointers[i] to point into the proper places in your block.
+If you use png_set_rows(), the application is responsible for freeing
+row_pointers (and row_pointers[i], if they were separately allocated).
+If you don't allocate row_pointers ahead of time, png_read_png() will
+do it, and it'll be free'ed by libpng when you call png_destroy_*().
+.SS The low-level read interface
+If you are going the low-level route, you are now ready to read all
+the file information up to the actual image data.  You do this with a
+call to png_read_info().
+    png_read_info(png_ptr, info_ptr);
+This will process all chunks up to but not including the image data.
+This also copies some of the data from the PNG file into the decode structure
+for use in later transformations.  Important information copied in is:
+1) The PNG file gamma from the gAMA chunk.  This overwrites the default value
+provided by an earlier call to png_set_gamma or png_set_alpha_mode.
+2) Prior to libpng-1.5.4 the background color from a bKGd chunk.  This
+damages the information provided by an earlier call to png_set_background
+resulting in unexpected behavior.  Libpng-1.5.4 no longer does this.
+3) The number of significant bits in each component value.  Libpng uses this to
+optimize gamma handling by reducing the internal lookup table sizes.
+4) The transparent color information from a tRNS chunk.  This can be modified by
+a later call to png_set_tRNS.
+.SS Querying the info structure
+Functions are used to get the information from the info_ptr once it
+has been read.  Note that these fields may not be completely filled
+in until png_read_end() has read the chunk data following the image.
+    png_get_IHDR(png_ptr, info_ptr, &width, &height,
+       &bit_depth, &color_type, &interlace_type,
+       &compression_type, &filter_method);
+    width          - holds the width of the image
+                     in pixels (up to 2^31).
+    height         - holds the height of the image
+                     in pixels (up to 2^31).
+    bit_depth      - holds the bit depth of one of the
+                     image channels.  (valid values are
+                     1, 2, 4, 8, 16 and depend also on
+                     the color_type.  See also
+                     significant bits (sBIT) below).
+    color_type     - describes which color/alpha channels
+                         are present.
+                     PNG_COLOR_TYPE_GRAY
+                        (bit depths 1, 2, 4, 8, 16)
+                     PNG_COLOR_TYPE_GRAY_ALPHA
+                        (bit depths 8, 16)
+                     PNG_COLOR_TYPE_PALETTE
+                        (bit depths 1, 2, 4, 8)
+                     PNG_COLOR_TYPE_RGB
+                        (bit_depths 8, 16)
+                     PNG_COLOR_TYPE_RGB_ALPHA
+                        (bit_depths 8, 16)
+                     PNG_COLOR_MASK_PALETTE
+                     PNG_COLOR_MASK_COLOR
+                     PNG_COLOR_MASK_ALPHA
+    interlace_type - (PNG_INTERLACE_NONE or
+                     PNG_INTERLACE_ADAM7)
+    compression_type - (must be PNG_COMPRESSION_TYPE_BASE
+                     for PNG 1.0)
+    filter_method  - (must be PNG_FILTER_TYPE_BASE
+                     for PNG 1.0, and can also be
+                     PNG_INTRAPIXEL_DIFFERENCING if
+                     the PNG datastream is embedded in
+                     a MNG-1.0 datastream)
+    Any or all of interlace_type, compression_type, or
+    filter_method can be NULL if you are
+    not interested in their values.
+    Note that png_get_IHDR() returns 32-bit data into
+    the application's width and height variables.
+    This is an unsafe situation if these are 16-bit
+    variables.  In such situations, the
+    png_get_image_width() and png_get_image_height()
+    functions described below are safer.
+    width            = png_get_image_width(png_ptr,
+                         info_ptr);
+    height           = png_get_image_height(png_ptr,
+                         info_ptr);
+    bit_depth        = png_get_bit_depth(png_ptr,
+                         info_ptr);
+    color_type       = png_get_color_type(png_ptr,
+                         info_ptr);
+    interlace_type   = png_get_interlace_type(png_ptr,
+                         info_ptr);
+    compression_type = png_get_compression_type(png_ptr,
+                         info_ptr);
+    filter_method    = png_get_filter_type(png_ptr,
+                         info_ptr);
+    channels = png_get_channels(png_ptr, info_ptr);
+    channels       - number of channels of info for the
+                     color type (valid values are 1 (GRAY,
+                     PALETTE), 2 (GRAY_ALPHA), 3 (RGB),
+                     4 (RGB_ALPHA or RGB + filler byte))
+    rowbytes = png_get_rowbytes(png_ptr, info_ptr);
+    rowbytes       - number of bytes needed to hold a row
+    signature = png_get_signature(png_ptr, info_ptr);
+    signature      - holds the signature read from the
+                     file (if any).  The data is kept in
+                     the same offset it would be if the
+                     whole signature were read (i.e. if an
+                     application had already read in 4
+                     bytes of signature before starting
+                     libpng, the remaining 4 bytes would
+                     be in signature[4] through signature[7]
+                     (see png_set_sig_bytes())).
+These are also important, but their validity depends on whether the chunk
+has been read.  The png_get_valid(png_ptr, info_ptr, PNG_INFO_<chunk>) and
+png_get_<chunk>(png_ptr, info_ptr, ...) functions return non-zero if the
+data has been read, or zero if it is missing.  The parameters to the
+png_get_<chunk> are set directly if they are simple data types, or a
+pointer into the info_ptr is returned for any complex types.
+    png_get_PLTE(png_ptr, info_ptr, &palette,
+                     &num_palette);
+    palette        - the palette for the file
+                     (array of png_color)
+    num_palette    - number of entries in the palette
+    png_get_gAMA(png_ptr, info_ptr, &file_gamma);
+    png_get_gAMA_fixed(png_ptr, info_ptr, &int_file_gamma);
+    file_gamma     - the gamma at which the file is
+                     written (PNG_INFO_gAMA)
+    int_file_gamma - 100,000 times the gamma at which the
+                     file is written
+    png_get_cHRM(png_ptr, info_ptr,  &white_x, &white_y, &red_x, &red_y,
+                     &green_x, &green_y, &blue_x, &blue_y)
+    png_get_cHRM_XYZ(png_ptr, info_ptr, &red_X, &red_Y, &red_Z, &green_X,
+                     &green_Y, &green_Z, &blue_X, &blue_Y, &blue_Z)
+    png_get_cHRM_fixed(png_ptr, info_ptr, &int_white_x, &int_white_y,
+                     &int_red_x, &int_red_y, &int_green_x, &int_green_y,
+                     &int_blue_x, &int_blue_y)
+    png_get_cHRM_XYZ_fixed(png_ptr, info_ptr, &int_red_X, &int_red_Y,
+                     &int_red_Z, &int_green_X, &int_green_Y, &int_green_Z,
+                     &int_blue_X, &int_blue_Y, &int_blue_Z)
+    {white,red,green,blue}_{x,y}
+                     A color space encoding specified using the chromaticities
+                     of the end points and the white point. (PNG_INFO_cHRM)
+    {red,green,blue}_{X,Y,Z}
+                     A color space encoding specified using the encoding end
+                     points - the CIE tristimulus specification of the intended
+                     color of the red, green and blue channels in the PNG RGB
+                     data.  The white point is simply the sum of the three end
+                     points. (PNG_INFO_cHRM)
+    png_get_sRGB(png_ptr, info_ptr, &srgb_intent);
+    file_srgb_intent - the rendering intent (PNG_INFO_sRGB)
+                     The presence of the sRGB chunk
+                     means that the pixel data is in the
+                     sRGB color space.  This chunk also
+                     implies specific values of gAMA and
+                     cHRM.
+    png_get_iCCP(png_ptr, info_ptr, &name,
+       &compression_type, &profile, &proflen);
+    name             - The profile name.
+    compression_type - The compression type; always
+                       PNG_COMPRESSION_TYPE_BASE for PNG 1.0.
+                       You may give NULL to this argument to
+                       ignore it.
+    profile          - International Color Consortium color
+                       profile data. May contain NULs.
+    proflen          - length of profile data in bytes.
+    png_get_sBIT(png_ptr, info_ptr, &sig_bit);
+    sig_bit        - the number of significant bits for
+                     (PNG_INFO_sBIT) each of the gray,
+                     red, green, and blue channels,
+                     whichever are appropriate for the
+                     given color type (png_color_16)
+    png_get_tRNS(png_ptr, info_ptr, &trans_alpha,
+                     &num_trans, &trans_color);
+    trans_alpha    - array of alpha (transparency)
+                     entries for palette (PNG_INFO_tRNS)
+    num_trans      - number of transparent entries
+                     (PNG_INFO_tRNS)
+    trans_color    - graylevel or color sample values of
+                     the single transparent color for
+                     non-paletted images (PNG_INFO_tRNS)
+    png_get_hIST(png_ptr, info_ptr, &hist);
+                     (PNG_INFO_hIST)
+    hist           - histogram of palette (array of
+                     png_uint_16)
+    png_get_tIME(png_ptr, info_ptr, &mod_time);
+    mod_time       - time image was last modified
+                    (PNG_VALID_tIME)
+    png_get_bKGD(png_ptr, info_ptr, &background);
+    background     - background color (of type
+                     png_color_16p) (PNG_VALID_bKGD)
+                     valid 16-bit red, green and blue
+                     values, regardless of color_type
+    num_comments   = png_get_text(png_ptr, info_ptr,
+                     &text_ptr, &num_text);
+    num_comments   - number of comments
+    text_ptr       - array of png_text holding image
+                     comments
+    text_ptr[i].compression - type of compression used
+                 on "text" PNG_TEXT_COMPRESSION_NONE
+                           PNG_TEXT_COMPRESSION_zTXt
+                           PNG_ITXT_COMPRESSION_NONE
+                           PNG_ITXT_COMPRESSION_zTXt
+    text_ptr[i].key   - keyword for comment.  Must contain
+                         1-79 characters.
+    text_ptr[i].text  - text comments for current
+                         keyword.  Can be empty.
+    text_ptr[i].text_length - length of text string,
+                 after decompression, 0 for iTXt
+    text_ptr[i].itxt_length - length of itxt string,
+                 after decompression, 0 for tEXt/zTXt
+    text_ptr[i].lang  - language of comment (empty
+                         string for unknown).
+    text_ptr[i].lang_key  - keyword in UTF-8
+                         (empty string for unknown).
+    Note that the itxt_length, lang, and lang_key
+    members of the text_ptr structure only exist when the
+    library is built with iTXt chunk support.  Prior to
+    libpng-1.4.0 the library was built by default without
+    iTXt support. Also note that when iTXt is supported,
+    they contain NULL pointers when the "compression"
+    field contains PNG_TEXT_COMPRESSION_NONE or
+    PNG_TEXT_COMPRESSION_zTXt.
+    num_text       - number of comments (same as
+                     num_comments; you can put NULL here
+                     to avoid the duplication)
+    Note while png_set_text() will accept text, language,
+    and translated keywords that can be NULL pointers, the
+    structure returned by png_get_text will always contain
+    regular zero-terminated C strings.  They might be
+    empty strings but they will never be NULL pointers.
+    num_spalettes = png_get_sPLT(png_ptr, info_ptr,
+       &palette_ptr);
+    num_spalettes  - number of sPLT chunks read.
+    palette_ptr    - array of palette structures holding
+                     contents of one or more sPLT chunks
+                     read.
+    png_get_oFFs(png_ptr, info_ptr, &offset_x, &offset_y,
+       &unit_type);
+    offset_x       - positive offset from the left edge
+                     of the screen (can be negative)
+    offset_y       - positive offset from the top edge
+                     of the screen (can be negative)
+    unit_type      - PNG_OFFSET_PIXEL, PNG_OFFSET_MICROMETER
+    png_get_pHYs(png_ptr, info_ptr, &res_x, &res_y,
+       &unit_type);
+    res_x          - pixels/unit physical resolution in
+                     x direction
+    res_y          - pixels/unit physical resolution in
+                     x direction
+    unit_type      - PNG_RESOLUTION_UNKNOWN,
+                     PNG_RESOLUTION_METER
+    png_get_sCAL(png_ptr, info_ptr, &unit, &width,
+       &height)
+    unit        - physical scale units (an integer)
+    width       - width of a pixel in physical scale units
+    height      - height of a pixel in physical scale units
+                 (width and height are doubles)
+    png_get_sCAL_s(png_ptr, info_ptr, &unit, &width,
+       &height)
+    unit        - physical scale units (an integer)
+    width       - width of a pixel in physical scale units
+                  (expressed as a string)
+    height      - height of a pixel in physical scale units
+                 (width and height are strings like "2.54")
+    num_unknown_chunks = png_get_unknown_chunks(png_ptr,
+       info_ptr, &unknowns)
+    unknowns          - array of png_unknown_chunk
+                        structures holding unknown chunks
+    unknowns[i].name  - name of unknown chunk
+    unknowns[i].data  - data of unknown chunk
+    unknowns[i].size  - size of unknown chunk's data
+    unknowns[i].location - position of chunk in file
+    The value of "i" corresponds to the order in which the
+    chunks were read from the PNG file or inserted with the
+    png_set_unknown_chunks() function.
+    The value of "location" is a bitwise "or" of
+         PNG_HAVE_IHDR  (0x01)
+         PNG_HAVE_PLTE  (0x02)
+         PNG_AFTER_IDAT (0x08)
+The data from the pHYs chunk can be retrieved in several convenient
+forms:
+    res_x = png_get_x_pixels_per_meter(png_ptr,
+       info_ptr)
+    res_y = png_get_y_pixels_per_meter(png_ptr,
+       info_ptr)
+    res_x_and_y = png_get_pixels_per_meter(png_ptr,
+       info_ptr)
+    res_x = png_get_x_pixels_per_inch(png_ptr,
+       info_ptr)
+    res_y = png_get_y_pixels_per_inch(png_ptr,
+       info_ptr)
+    res_x_and_y = png_get_pixels_per_inch(png_ptr,
+       info_ptr)
+    aspect_ratio = png_get_pixel_aspect_ratio(png_ptr,
+       info_ptr)
+    Each of these returns 0 [signifying "unknown"] if
+       the data is not present or if res_x is 0;
+       res_x_and_y is 0 if res_x != res_y
+    Note that because of the way the resolutions are
+       stored internally, the inch conversions won't
+       come out to exactly even number.  For example,
+       72 dpi is stored as 0.28346 pixels/meter, and
+       when this is retrieved it is 71.9988 dpi, so
+       be sure to round the returned value appropriately
+       if you want to display a reasonable-looking result.
+The data from the oFFs chunk can be retrieved in several convenient
+forms:
+    x_offset = png_get_x_offset_microns(png_ptr, info_ptr);
+    y_offset = png_get_y_offset_microns(png_ptr, info_ptr);
+    x_offset = png_get_x_offset_inches(png_ptr, info_ptr);
+    y_offset = png_get_y_offset_inches(png_ptr, info_ptr);
+    Each of these returns 0 [signifying "unknown" if both
+       x and y are 0] if the data is not present or if the
+       chunk is present but the unit is the pixel.  The
+       remark about inexact inch conversions applies here
+       as well, because a value in inches can't always be
+       converted to microns and back without some loss
+       of precision.
+For more information, see the
+PNG specification for chunk contents.  Be careful with trusting
+rowbytes, as some of the transformations could increase the space
+needed to hold a row (expand, filler, gray_to_rgb, etc.).
+See png_read_update_info(), below.
+A quick word about text_ptr and num_text.  PNG stores comments in
+keyword/text pairs, one pair per chunk, with no limit on the number
+of text chunks, and a 2^31 byte limit on their size.  While there are
+suggested keywords, there is no requirement to restrict the use to these
+strings.  It is strongly suggested that keywords and text be sensible
+to humans (that's the point), so don't use abbreviations.  Non-printing
+symbols are not allowed.  See the PNG specification for more details.
+There is also no requirement to have text after the keyword.
+Keywords should be limited to 79 Latin-1 characters without leading or
+trailing spaces, but non-consecutive spaces are allowed within the
+keyword.  It is possible to have the same keyword any number of times.
+The text_ptr is an array of png_text structures, each holding a
+pointer to a language string, a pointer to a keyword and a pointer to
+a text string.  The text string, language code, and translated
+keyword may be empty or NULL pointers.  The keyword/text
+pairs are put into the array in the order that they are received.
+However, some or all of the text chunks may be after the image, so, to
+make sure you have read all the text chunks, don't mess with these
+until after you read the stuff after the image.  This will be
+mentioned again below in the discussion that goes with png_read_end().
+.SS Input transformations
+After you've read the header information, you can set up the library
+to handle any special transformations of the image data.  The various
+ways to transform the data will be described in the order that they
+should occur.  This is important, as some of these change the color
+type and/or bit depth of the data, and some others only work on
+certain color types and bit depths.
+Transformations you request are ignored if they don't have any meaning for a
+particular input data format.  However some transformations can have an effect
+as a result of a previous transformation.  If you specify a contradictory set of
+transformations, for example both adding and removing the alpha channel, you
+cannot predict the final result.
+The color used for the transparency values should be supplied in the same
+format/depth as the current image data.  It is stored in the same format/depth
+as the image data in a tRNS chunk, so this is what libpng expects for this data.
+The color used for the background value depends on the need_expand argument as
+described below.
+Data will be decoded into the supplied row buffers packed into bytes
+unless the library has been told to transform it into another format.
+For example, 4 bit/pixel paletted or grayscale data will be returned
+2 pixels/byte with the leftmost pixel in the high-order bits of the
+byte, unless png_set_packing() is called.  8-bit RGB data will be stored
+in RGB RGB RGB format unless png_set_filler() or png_set_add_alpha()
+is called to insert filler bytes, either before or after each RGB triplet.
+16-bit RGB data will be returned RRGGBB RRGGBB, with the most significant
+byte of the color value first, unless png_set_scale_16() is called to
+transform it to regular RGB RGB triplets, or png_set_filler() or
+png_set_add alpha() is called to insert filler bytes, either before or
+after each RRGGBB triplet.  Similarly, 8-bit or 16-bit grayscale data can
+be modified with png_set_filler(), png_set_add_alpha(), png_set_strip_16(),
+or png_set_scale_16().
+The following code transforms grayscale images of less than 8 to 8 bits,
+changes paletted images to RGB, and adds a full alpha channel if there is
+transparency information in a tRNS chunk.  This is most useful on
+grayscale images with bit depths of 2 or 4 or if there is a multiple-image
+viewing application that wishes to treat all images in the same way.
+    if (color_type == PNG_COLOR_TYPE_PALETTE)
+        png_set_palette_to_rgb(png_ptr);
+    if (png_get_valid(png_ptr, info_ptr,
+        PNG_INFO_tRNS)) png_set_tRNS_to_alpha(png_ptr);
+    if (color_type == PNG_COLOR_TYPE_GRAY &&
+        bit_depth < 8) png_set_expand_gray_1_2_4_to_8(png_ptr);
+The first two functions are actually aliases for png_set_expand(), added
+in libpng version 1.0.4, with the function names expanded to improve code
+readability.  In some future version they may actually do different
+things.
+As of libpng version 1.2.9, png_set_expand_gray_1_2_4_to_8() was
+added.  It expands the sample depth without changing tRNS to alpha.
+As of libpng version 1.5.2, png_set_expand_16() was added.  It behaves as
+png_set_expand(); however, the resultant channels have 16 bits rather than 8.
+Use this when the output color or gray channels are made linear to avoid fairly
+severe accuracy loss.
+   if (bit_depth < 16)
+      png_set_expand_16(png_ptr);
+PNG can have files with 16 bits per channel.  If you only can handle
+8 bits per channel, this will strip the pixels down to 8-bit.
+    if (bit_depth == 16)
+#if PNG_LIBPNG_VER >= 10504
+       png_set_scale_16(png_ptr);
+#else
+       png_set_strip_16(png_ptr);
+#endif
+(The more accurate "png_set_scale_16()" API became available in libpng version
+1.5.4).
+If you need to process the alpha channel on the image separately from the image
+data (for example if you convert it to a bitmap mask) it is possible to have
+libpng strip the channel leaving just RGB or gray data:
+    if (color_type & PNG_COLOR_MASK_ALPHA)
+       png_set_strip_alpha(png_ptr);
+If you strip the alpha channel you need to find some other way of dealing with
+the information.  If, instead, you want to convert the image to an opaque
+version with no alpha channel use png_set_background; see below.
+As of libpng version 1.5.2, almost all useful expansions are supported, the
+major ommissions are conversion of grayscale to indexed images (which can be
+done trivially in the application) and conversion of indexed to grayscale (which
+can be done by a trivial manipulation of the palette.)
+In the following table, the 01 means grayscale with depth<8, 31 means
+indexed with depth<8, other numerals represent the color type, "T" means
+the tRNS chunk is present, A means an alpha channel is present, and O
+means tRNS or alpha is present but all pixels in the image are opaque.
+  FROM  01  31   0  0T  0O   2  2T  2O   3  3T  3O  4A  4O  6A  6O
+   TO
+   01    -  [G]  -   -   -   -   -   -   -   -   -   -   -   -   -
+   31   [Q]  Q  [Q] [Q] [Q]  Q   Q   Q   Q   Q   Q  [Q] [Q]  Q   Q
+    0    1   G   +   .   .   G   G   G   G   G   G   B   B  GB  GB
+   0T    lt  Gt  t   +   .   Gt  G   G   Gt  G   G   Bt  Bt GBt GBt
+   0O    lt  Gt  t   .   +   Gt  Gt  G   Gt  Gt  G   Bt  Bt GBt GBt
+    2    C   P   C   C   C   +   .   .   C   -   -  CB  CB   B   B
+   2T    Ct  -   Ct  C   C   t   +   t   -   -   -  CBt CBt  Bt  Bt
+   2O    Ct  -   Ct  C   C   t   t   +   -   -   -  CBt CBt  Bt  Bt
+    3   [Q]  p  [Q] [Q] [Q]  Q   Q   Q   +   .   .  [Q] [Q]  Q   Q
+   3T   [Qt] p  [Qt][Q] [Q]  Qt  Qt  Qt  t   +   t  [Qt][Qt] Qt  Qt
+   3O   [Qt] p  [Qt][Q] [Q]  Qt  Qt  Qt  t   t   +  [Qt][Qt] Qt  Qt
+   4A    lA  G   A   T   T   GA  GT  GT  GA  GT  GT  +   BA  G  GBA
+   4O    lA GBA  A   T   T   GA  GT  GT  GA  GT  GT  BA  +  GBA  G
+   6A    CA  PA  CA  C   C   A   T  tT   PA  P   P   C  CBA  +   BA
+   6O    CA PBA  CA  C   C   A  tT   T   PA  P   P  CBA  C   BA  +
+Within the matrix,
+     "+" identifies entries where 'from' and 'to' are the same.
+     "-" means the transformation is not supported.
+     "." means nothing is necessary (a tRNS chunk can just be ignored).
+     "t" means the transformation is obtained by png_set_tRNS.
+     "A" means the transformation is obtained by png_set_add_alpha().
+     "X" means the transformation is obtained by png_set_expand().
+     "1" means the transformation is obtained by
+         png_set_expand_gray_1_2_4_to_8() (and by png_set_expand() if there
+         is no transparency in the original or the final format).
+     "C" means the transformation is obtained by png_set_gray_to_rgb().
+     "G" means the transformation is obtained by png_set_rgb_to_gray().
+     "P" means the transformation is obtained by
+         png_set_expand_palette_to_rgb().
+     "p" means the transformation is obtained by png_set_packing().
+     "Q" means the transformation is obtained by png_set_quantize().
+     "T" means the transformation is obtained by png_set_tRNS_to_alpha().
+     "B" means the transformation is obtained by png_set_background(), or
+         png_strip_alpha().
+When an entry has multiple transforms listed all are required to cause the
+right overall transformation.  When two transforms are separated by a comma
+either will do the job.  When transforms are enclosed in [] the transform should
+do the job but this is currently unimplemented - a different format will result
+if the suggested transformations are used.
+In PNG files, the alpha channel in an image
+is the level of opacity.  If you need the alpha channel in an image to
+be the level of transparency instead of opacity, you can invert the
+alpha channel (or the tRNS chunk data) after it's read, so that 0 is
+fully opaque and 255 (in 8-bit or paletted images) or 65535 (in 16-bit
+images) is fully transparent, with
+    png_set_invert_alpha(png_ptr);
+PNG files pack pixels of bit depths 1, 2, and 4 into bytes as small as
+they can, resulting in, for example, 8 pixels per byte for 1 bit
+files.  This code expands to 1 pixel per byte without changing the
+values of the pixels:
+    if (bit_depth < 8)
+       png_set_packing(png_ptr);
+PNG files have possible bit depths of 1, 2, 4, 8, and 16.  All pixels
+stored in a PNG image have been "scaled" or "shifted" up to the next
+higher possible bit depth (e.g. from 5 bits/sample in the range [0,31]
+to 8 bits/sample in the range [0, 255]).  However, it is also possible
+to convert the PNG pixel data back to the original bit depth of the
+image.  This call reduces the pixels back down to the original bit depth:
+    png_color_8p sig_bit;
+    if (png_get_sBIT(png_ptr, info_ptr, &sig_bit))
+       png_set_shift(png_ptr, sig_bit);
+PNG files store 3-color pixels in red, green, blue order.  This code
+changes the storage of the pixels to blue, green, red:
+    if (color_type == PNG_COLOR_TYPE_RGB ||
+        color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+       png_set_bgr(png_ptr);
+PNG files store RGB pixels packed into 3 or 6 bytes. This code expands them
+into 4 or 8 bytes for windowing systems that need them in this format:
+    if (color_type == PNG_COLOR_TYPE_RGB)
+       png_set_filler(png_ptr, filler, PNG_FILLER_BEFORE);
+where "filler" is the 8 or 16-bit number to fill with, and the location is
+either PNG_FILLER_BEFORE or PNG_FILLER_AFTER, depending upon whether
+you want the filler before the RGB or after.  This transformation
+does not affect images that already have full alpha channels.  To add an
+opaque alpha channel, use filler=0xff or 0xffff and PNG_FILLER_AFTER which
+will generate RGBA pixels.
+Note that png_set_filler() does not change the color type.  If you want
+to do that, you can add a true alpha channel with
+    if (color_type == PNG_COLOR_TYPE_RGB ||
+       color_type == PNG_COLOR_TYPE_GRAY)
+       png_set_add_alpha(png_ptr, filler, PNG_FILLER_AFTER);
+where "filler" contains the alpha value to assign to each pixel.
+This function was added in libpng-1.2.7.
+If you are reading an image with an alpha channel, and you need the
+data as ARGB instead of the normal PNG format RGBA:
+    if (color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+       png_set_swap_alpha(png_ptr);
+For some uses, you may want a grayscale image to be represented as
+RGB.  This code will do that conversion:
+    if (color_type == PNG_COLOR_TYPE_GRAY ||
+        color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+       png_set_gray_to_rgb(png_ptr);
+Conversely, you can convert an RGB or RGBA image to grayscale or grayscale
+with alpha.
+    if (color_type == PNG_COLOR_TYPE_RGB ||
+        color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+       png_set_rgb_to_gray(png_ptr, error_action, double red_weight,
+          double green_weight);
+    error_action = 1: silently do the conversion
+    error_action = 2: issue a warning if the original
+                      image has any pixel where
+                      red != green or red != blue
+    error_action = 3: issue an error and abort the
+                      conversion if the original
+                      image has any pixel where
+                      red != green or red != blue
+    red_weight:       weight of red component
+    green_weight:     weight of green component
+                      If either weight is negative, default
+                      weights are used.
+In the corresponding fixed point API the red_weight and green_weight values are
+simply scaled by 100,000:
+    png_set_rgb_to_gray(png_ptr, error_action, png_fixed_point red_weight,
+       png_fixed_point green_weight);
+If you have set error_action = 1 or 2, you can
+later check whether the image really was gray, after processing
+the image rows, with the png_get_rgb_to_gray_status(png_ptr) function.
+It will return a png_byte that is zero if the image was gray or
+1 if there were any non-gray pixels.  Background and sBIT data
+will be silently converted to grayscale, using the green channel
+data for sBIT, regardless of the error_action setting.
+The default values come from the PNG file cHRM chunk if present; otherwise, the
+defaults correspond to the ITU-R recommendation 709, and also the sRGB color
+space, as recommended in the Charles Poynton's Colour FAQ,
+<http://www.poynton.com/>, in section 9:
+   <http://www.poynton.com/notes/colour_and_gamma/ColorFAQ.html#RTFToC9>
+    Y = 0.2126 * R + 0.7152 * G + 0.0722 * B
+Previous versions of this document, 1998 through 2002, recommended a slightly
+different formula:
+    Y = 0.212671 * R + 0.715160 * G + 0.072169 * B
+Libpng uses an integer approximation:
+    Y = (6968 * R + 23434 * G + 2366 * B)/32768
+The calculation is done in a linear colorspace, if the image gamma
+can be determined.
+The png_set_background() function has been described already; it tells libpng to
+composite images with alpha or simple transparency against the supplied
+background color.  For compatibility with versions of libpng earlier than
+libpng-1.5.4 it is recommended that you call the function after reading the file
+header, even if you don't want to use the color in a bKGD chunk, if one exists.
+If the PNG file contains a bKGD chunk (PNG_INFO_bKGD valid),
+you may use this color, or supply another color more suitable for
+the current display (e.g., the background color from a web page).  You
+need to tell libpng how the color is represented, both the format of the
+component values in the color (the number of bits) and the gamma encoding of the
+color.  The function takes two arguments, background_gamma_mode and need_expand
+to convey this information, however only two combinations are likely to be
+useful:
+    png_color_16 my_background;
+    png_color_16p image_background;
+    if (png_get_bKGD(png_ptr, info_ptr, &image_background))
+       png_set_background(png_ptr, image_background,
+           PNG_BACKGROUND_GAMMA_FILE, 1/*needs to be expanded*/, 1);
+    else
+       png_set_background(png_ptr, &my_background,
+           PNG_BACKGROUND_GAMMA_SCREEN, 0/*do not expand*/, 1);
+The second call was described above - my_background is in the format of the
+final, display, output produced by libpng.  Because you now know the format of
+the PNG it is possible to avoid the need to choose either 8-bit or 16-bit
+output and to retain palette images (the palette colors will be modified
+appropriately and the tRNS chunk removed.)  However, if you are doing this,
+take great care not to ask for transformations without checking first that
+they apply!
+In the first call the background color has the original bit depth and color type
+of the PNG file.  So, for palette images the color is supplied as a palette
+index and for low bit greyscale images the color is a reduced bit value in
+image_background->gray.
+If you didn't call png_set_gamma() before reading the file header, for example
+if you need your code to remain compatible with older versions of libpng prior
+to libpng-1.5.4, this is the place to call it.
+Do not call it if you called png_set_alpha_mode(); doing so will damage the
+settings put in place by png_set_alpha_mode().  (If png_set_alpha_mode() is
+supported then you can certainly do png_set_gamma() before reading the PNG
+header.)
+This API unconditionally sets the screen and file gamma values, so it will
+override the value in the PNG file unless it is called before the PNG file
+reading starts.  For this reason you must always call it with the PNG file
+value when you call it in this position:
+   if (png_get_gAMA(png_ptr, info_ptr, &file_gamma))
+      png_set_gamma(png_ptr, screen_gamma, file_gamma);
+   else
+      png_set_gamma(png_ptr, screen_gamma, 0.45455);
+If you need to reduce an RGB file to a paletted file, or if a paletted
+file has more entries then will fit on your screen, png_set_quantize()
+will do that.  Note that this is a simple match quantization that merely
+finds the closest color available.  This should work fairly well with
+optimized palettes, but fairly badly with linear color cubes.  If you
+pass a palette that is larger than maximum_colors, the file will
+reduce the number of colors in the palette so it will fit into
+maximum_colors.  If there is a histogram, libpng will use it to make
+more intelligent choices when reducing the palette.  If there is no
+histogram, it may not do as good a job.
+   if (color_type & PNG_COLOR_MASK_COLOR)
+   {
+      if (png_get_valid(png_ptr, info_ptr,
+          PNG_INFO_PLTE))
+      {
+         png_uint_16p histogram = NULL;
+         png_get_hIST(png_ptr, info_ptr,
+             &histogram);
+         png_set_quantize(png_ptr, palette, num_palette,
+            max_screen_colors, histogram, 1);
+      }
+      else
+      {
+         png_color std_color_cube[MAX_SCREEN_COLORS] =
+            { ... colors ... };
+         png_set_quantize(png_ptr, std_color_cube,
+            MAX_SCREEN_COLORS, MAX_SCREEN_COLORS,
+            NULL,0);
+      }
+   }
+PNG files describe monochrome as black being zero and white being one.
+The following code will reverse this (make black be one and white be
+zero):
+   if (bit_depth == 1 && color_type == PNG_COLOR_TYPE_GRAY)
+      png_set_invert_mono(png_ptr);
+This function can also be used to invert grayscale and gray-alpha images:
+   if (color_type == PNG_COLOR_TYPE_GRAY ||
+       color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+      png_set_invert_mono(png_ptr);
+PNG files store 16-bit pixels in network byte order (big-endian,
+ie. most significant bits first).  This code changes the storage to the
+other way (little-endian, i.e. least significant bits first, the
+way PCs store them):
+    if (bit_depth == 16)
+       png_set_swap(png_ptr);
+If you are using packed-pixel images (1, 2, or 4 bits/pixel), and you
+need to change the order the pixels are packed into bytes, you can use:
+    if (bit_depth < 8)
+       png_set_packswap(png_ptr);
+Finally, you can write your own transformation function if none of
+the existing ones meets your needs.  This is done by setting a callback
+with
+    png_set_read_user_transform_fn(png_ptr,
+        read_transform_fn);
+You must supply the function
+    void read_transform_fn(png_structp png_ptr, png_row_infop
+        row_info, png_bytep data)
+See pngtest.c for a working example.  Your function will be called
+after all of the other transformations have been processed.  Take care with
+interlaced images if you do the interlace yourself - the width of the row is the
+width in 'row_info', not the overall image width.
+If supported, libpng provides two information routines that you can use to find
+where you are in processing the image:
+   png_get_current_pass_number(png_structp png_ptr);
+   png_get_current_row_number(png_structp png_ptr);
+Don't try using these outside a transform callback - firstly they are only
+supported if user transforms are supported, secondly they may well return
+unexpected results unless the row is actually being processed at the moment they
+are called.
+With interlaced
+images the value returned is the row in the input sub-image image.  Use
+PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
+find the output pixel (x,y) given an interlaced sub-image pixel (row,col,pass).
+The discussion of interlace handling above contains more information on how to
+use these values.
+You can also set up a pointer to a user structure for use by your
+callback function, and you can inform libpng that your transform
+function will change the number of channels or bit depth with the
+function
+    png_set_user_transform_info(png_ptr, user_ptr,
+        user_depth, user_channels);
+The user's application, not libpng, is responsible for allocating and
+freeing any memory required for the user structure.
+You can retrieve the pointer via the function
+png_get_user_transform_ptr().  For example:
+    voidp read_user_transform_ptr =
+        png_get_user_transform_ptr(png_ptr);
+The last thing to handle is interlacing; this is covered in detail below,
+but you must call the function here if you want libpng to handle expansion
+of the interlaced image.
+    number_of_passes = png_set_interlace_handling(png_ptr);
+After setting the transformations, libpng can update your png_info
+structure to reflect any transformations you've requested with this
+call.
+    png_read_update_info(png_ptr, info_ptr);
+This is most useful to update the info structure's rowbytes
+field so you can use it to allocate your image memory.  This function
+will also update your palette with the correct screen_gamma and
+background if these have been given with the calls above.  You may
+only call png_read_update_info() once with a particular info_ptr.
+After you call png_read_update_info(), you can allocate any
+memory you need to hold the image.  The row data is simply
+raw byte data for all forms of images.  As the actual allocation
+varies among applications, no example will be given.  If you
+are allocating one large chunk, you will need to build an
+array of pointers to each row, as it will be needed for some
+of the functions below.
+Remember: Before you call png_read_update_info(), the png_get_*()
+functions return the values corresponding to the original PNG image.
+After you call png_read_update_info the values refer to the image
+that libpng will output.  Consequently you must call all the png_set_
+functions before you call png_read_update_info().  This is particularly
+important for png_set_interlace_handling() - if you are going to call
+png_read_update_info() you must call png_set_interlace_handling() before
+it unless you want to receive interlaced output.
+.SS Reading image data
+After you've allocated memory, you can read the image data.
+The simplest way to do this is in one function call.  If you are
+allocating enough memory to hold the whole image, you can just
+call png_read_image() and libpng will read in all the image data
+and put it in the memory area supplied.  You will need to pass in
+an array of pointers to each row.
+This function automatically handles interlacing, so you don't
+need to call png_set_interlace_handling() (unless you call
+png_read_update_info()) or call this function multiple times, or any
+of that other stuff necessary with png_read_rows().
+   png_read_image(png_ptr, row_pointers);
+where row_pointers is:
+   png_bytep row_pointers[height];
+You can point to void or char or whatever you use for pixels.
+If you don't want to read in the whole image at once, you can
+use png_read_rows() instead.  If there is no interlacing (check
+interlace_type == PNG_INTERLACE_NONE), this is simple:
+    png_read_rows(png_ptr, row_pointers, NULL,
+        number_of_rows);
+where row_pointers is the same as in the png_read_image() call.
+If you are doing this just one row at a time, you can do this with
+a single row_pointer instead of an array of row_pointers:
+    png_bytep row_pointer = row;
+    png_read_row(png_ptr, row_pointer, NULL);
+If the file is interlaced (interlace_type != 0 in the IHDR chunk), things
+get somewhat harder.  The only current (PNG Specification version 1.2)
+interlacing type for PNG is (interlace_type == PNG_INTERLACE_ADAM7);
+a somewhat complicated 2D interlace scheme, known as Adam7, that
+breaks down an image into seven smaller images of varying size, based
+on an 8x8 grid.  This number is defined (from libpng 1.5) as
+PNG_INTERLACE_ADAM7_PASSES in png.h
+libpng can fill out those images or it can give them to you "as is".
+It is almost always better to have libpng handle the interlacing for you.
+If you want the images filled out, there are two ways to do that.  The one
+mentioned in the PNG specification is to expand each pixel to cover
+those pixels that have not been read yet (the "rectangle" method).
+This results in a blocky image for the first pass, which gradually
+smooths out as more pixels are read.  The other method is the "sparkle"
+method, where pixels are drawn only in their final locations, with the
+rest of the image remaining whatever colors they were initialized to
+before the start of the read.  The first method usually looks better,
+but tends to be slower, as there are more pixels to put in the rows.
+If, as is likely, you want libpng to expand the images, call this before
+calling png_start_read_image() or png_read_update_info():
+    if (interlace_type == PNG_INTERLACE_ADAM7)
+       number_of_passes
+           = png_set_interlace_handling(png_ptr);
+This will return the number of passes needed.  Currently, this is seven,
+but may change if another interlace type is added.  This function can be
+called even if the file is not interlaced, where it will return one pass.
+You then need to read the whole image 'number_of_passes' times.  Each time
+will distribute the pixels from the current pass to the correct place in
+the output image, so you need to supply the same rows to png_read_rows in
+each pass.
+If you are not going to display the image after each pass, but are
+going to wait until the entire image is read in, use the sparkle
+effect.  This effect is faster and the end result of either method
+is exactly the same.  If you are planning on displaying the image
+after each pass, the "rectangle" effect is generally considered the
+better looking one.
+If you only want the "sparkle" effect, just call png_read_rows() as
+normal, with the third parameter NULL.  Make sure you make pass over
+the image number_of_passes times, and you don't change the data in the
+rows between calls.  You can change the locations of the data, just
+not the data.  Each pass only writes the pixels appropriate for that
+pass, and assumes the data from previous passes is still valid.
+    png_read_rows(png_ptr, row_pointers, NULL,
+        number_of_rows);
+If you only want the first effect (the rectangles), do the same as
+before except pass the row buffer in the third parameter, and leave
+the second parameter NULL.
+    png_read_rows(png_ptr, NULL, row_pointers,
+        number_of_rows);
+If you don't want libpng to handle the interlacing details, just call
+png_read_rows() PNG_INTERLACE_ADAM7_PASSES times to read in all the images.
+Each of the images is a valid image by itself, however you will almost
+certainly need to distribute the pixels from each sub-image to the
+correct place.  This is where everything gets very tricky.
+If you want to retrieve the separate images you must pass the correct
+number of rows to each successive call of png_read_rows().  The calculation
+gets pretty complicated for small images, where some sub-images may
+not even exist because either their width or height ends up zero.
+libpng provides two macros to help you in 1.5 and later versions:
+   png_uint_32 width = PNG_PASS_COLS(image_width, pass_number);
+   png_uint_32 height = PNG_PASS_ROWS(image_height, pass_number);
+Respectively these tell you the width and height of the sub-image
+corresponding to the numbered pass.  'pass' is in in the range 0 to 6 -
+this can be confusing because the specification refers to the same passes
+as 1 to 7!  Be careful, you must check both the width and height before
+calling png_read_rows() and not call it for that pass if either is zero.
+You can, of course, read each sub-image row by row.  If you want to
+produce optimal code to make a pixel-by-pixel transformation of an
+interlaced image this is the best approach; read each row of each pass,
+transform it, and write it out to a new interlaced image.
+If you want to de-interlace the image yourself libpng provides further
+macros to help that tell you where to place the pixels in the output image.
+Because the interlacing scheme is rectangular - sub-image pixels are always
+arranged on a rectangular grid - all you need to know for each pass is the
+starting column and row in the output image of the first pixel plus the
+spacing between each pixel.  As of libpng 1.5 there are four macros to
+retrieve this information:
+   png_uint_32 x = PNG_PASS_START_COL(pass);
+   png_uint_32 y = PNG_PASS_START_ROW(pass);
+   png_uint_32 xStep = 1U << PNG_PASS_COL_SHIFT(pass);
+   png_uint_32 yStep = 1U << PNG_PASS_ROW_SHIFT(pass);
+These allow you to write the obvious loop:
+   png_uint_32 input_y = 0;
+   png_uint_32 output_y = PNG_PASS_START_ROW(pass);
+   while (output_y < output_image_height)
+   {
+      png_uint_32 input_x = 0;
+      png_uint_32 output_x = PNG_PASS_START_COL(pass);
+      while (output_x < output_image_width)
+      {
+         image[output_y][output_x] =
+             subimage[pass][input_y][input_x++];
+         output_x += xStep;
+      }
+      ++input_y;
+      output_y += yStep;
+   }
+Notice that the steps between successive output rows and columns are
+returned as shifts.  This is possible because the pixels in the subimages
+are always a power of 2 apart - 1, 2, 4 or 8 pixels - in the original
+image.  In practice you may need to directly calculate the output coordinate
+given an input coordinate.  libpng provides two further macros for this
+purpose:
+   png_uint_32 output_x = PNG_COL_FROM_PASS_COL(input_x, pass);
+   png_uint_32 output_y = PNG_ROW_FROM_PASS_ROW(input_y, pass);
+Finally a pair of macros are provided to tell you if a particular image
+row or column appears in a given pass:
+   int col_in_pass = PNG_COL_IN_INTERLACE_PASS(output_x, pass);
+   int row_in_pass = PNG_ROW_IN_INTERLACE_PASS(output_y, pass);
+Bear in mind that you will probably also need to check the width and height
+of the pass in addition to the above to be sure the pass even exists!
+With any luck you are convinced by now that you don't want to do your own
+interlace handling.  In reality normally the only good reason for doing this
+is if you are processing PNG files on a pixel-by-pixel basis and don't want
+to load the whole file into memory when it is interlaced.
+libpng includes a test program, pngvalid, that illustrates reading and
+writing of interlaced images.  If you can't get interlacing to work in your
+code and don't want to leave it to libpng (the recommended approach), see
+how pngvalid.c does it.
+.SS Finishing a sequential read
+After you are finished reading the image through the
+low-level interface, you can finish reading the file.  If you are
+interested in comments or time, which may be stored either before or
+after the image data, you should pass the separate png_info struct if
+you want to keep the comments from before and after the image
+separate.
+    png_infop end_info = png_create_info_struct(png_ptr);
+    if (!end_info)
+    {
+       png_destroy_read_struct(&png_ptr, &info_ptr,
+           (png_infopp)NULL);
+       return (ERROR);
+    }
+   png_read_end(png_ptr, end_info);
+If you are not interested, you should still call png_read_end()
+but you can pass NULL, avoiding the need to create an end_info structure.
+   png_read_end(png_ptr, (png_infop)NULL);
+If you don't call png_read_end(), then your file pointer will be
+left pointing to the first chunk after the last IDAT, which is probably
+not what you want if you expect to read something beyond the end of
+the PNG datastream.
+When you are done, you can free all memory allocated by libpng like this:
+   png_destroy_read_struct(&png_ptr, &info_ptr,
+       &end_info);
+or, if you didn't create an end_info structure,
+   png_destroy_read_struct(&png_ptr, &info_ptr,
+       (png_infopp)NULL);
+It is also possible to individually free the info_ptr members that
+point to libpng-allocated storage with the following function:
+    png_free_data(png_ptr, info_ptr, mask, seq)
+    mask - identifies data to be freed, a mask
+           containing the bitwise OR of one or
+           more of
+             PNG_FREE_PLTE, PNG_FREE_TRNS,
+             PNG_FREE_HIST, PNG_FREE_ICCP,
+             PNG_FREE_PCAL, PNG_FREE_ROWS,
+             PNG_FREE_SCAL, PNG_FREE_SPLT,
+             PNG_FREE_TEXT, PNG_FREE_UNKN,
+           or simply PNG_FREE_ALL
+    seq  - sequence number of item to be freed
+           (-1 for all items)
+This function may be safely called when the relevant storage has
+already been freed, or has not yet been allocated, or was allocated
+by the user and not by libpng,  and will in those cases do nothing.
+The "seq" parameter is ignored if only one item of the selected data
+type, such as PLTE, is allowed.  If "seq" is not -1, and multiple items
+are allowed for the data type identified in the mask, such as text or
+sPLT, only the n'th item in the structure is freed, where n is "seq".
+The default behavior is only to free data that was allocated internally
+by libpng.  This can be changed, so that libpng will not free the data,
+or so that it will free data that was allocated by the user with png_malloc()
+or png_zalloc() and passed in via a png_set_*() function, with
+    png_data_freer(png_ptr, info_ptr, freer, mask)
+    freer  - one of
+               PNG_DESTROY_WILL_FREE_DATA
+               PNG_SET_WILL_FREE_DATA
+               PNG_USER_WILL_FREE_DATA
+    mask   - which data elements are affected
+             same choices as in png_free_data()
+This function only affects data that has already been allocated.
+You can call this function after reading the PNG data but before calling
+any png_set_*() functions, to control whether the user or the png_set_*()
+function is responsible for freeing any existing data that might be present,
+and again after the png_set_*() functions to control whether the user
+or png_destroy_*() is supposed to free the data.  When the user assumes
+responsibility for libpng-allocated data, the application must use
+png_free() to free it, and when the user transfers responsibility to libpng
+for data that the user has allocated, the user must have used png_malloc()
+or png_zalloc() to allocate it.
+If you allocated your row_pointers in a single block, as suggested above in
+the description of the high level read interface, you must not transfer
+responsibility for freeing it to the png_set_rows or png_read_destroy function,
+because they would also try to free the individual row_pointers[i].
+If you allocated text_ptr.text, text_ptr.lang, and text_ptr.translated_keyword
+separately, do not transfer responsibility for freeing text_ptr to libpng,
+because when libpng fills a png_text structure it combines these members with
+the key member, and png_free_data() will free only text_ptr.key.  Similarly,
+if you transfer responsibility for free'ing text_ptr from libpng to your
+application, your application must not separately free those members.
+The png_free_data() function will turn off the "valid" flag for anything
+it frees.  If you need to turn the flag off for a chunk that was freed by
+your application instead of by libpng, you can use
+    png_set_invalid(png_ptr, info_ptr, mask);
+    mask - identifies the chunks to be made invalid,
+           containing the bitwise OR of one or
+           more of
+             PNG_INFO_gAMA, PNG_INFO_sBIT,
+             PNG_INFO_cHRM, PNG_INFO_PLTE,
+             PNG_INFO_tRNS, PNG_INFO_bKGD,
+             PNG_INFO_hIST, PNG_INFO_pHYs,
+             PNG_INFO_oFFs, PNG_INFO_tIME,
+             PNG_INFO_pCAL, PNG_INFO_sRGB,
+             PNG_INFO_iCCP, PNG_INFO_sPLT,
+             PNG_INFO_sCAL, PNG_INFO_IDAT
+For a more compact example of reading a PNG image, see the file example.c.
+.SS Reading PNG files progressively
+The progressive reader is slightly different then the non-progressive
+reader.  Instead of calling png_read_info(), png_read_rows(), and
+png_read_end(), you make one call to png_process_data(), which calls
+callbacks when it has the info, a row, or the end of the image.  You
+set up these callbacks with png_set_progressive_read_fn().  You don't
+have to worry about the input/output functions of libpng, as you are
+giving the library the data directly in png_process_data().  I will
+assume that you have read the section on reading PNG files above,
+so I will only highlight the differences (although I will show
+all of the code).
+png_structp png_ptr;
+png_infop info_ptr;
+ /*  An example code fragment of how you would
+     initialize the progressive reader in your
+     application. */
+ int
+ initialize_png_reader()
+ {
+    png_ptr = png_create_read_struct
+        (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
+         user_error_fn, user_warning_fn);
+    if (!png_ptr)
+        return (ERROR);
+    info_ptr = png_create_info_struct(png_ptr);
+    if (!info_ptr)
+    {
+       png_destroy_read_struct(&png_ptr,
+          (png_infopp)NULL, (png_infopp)NULL);
+       return (ERROR);
+    }
+    if (setjmp(png_jmpbuf(png_ptr)))
+    {
+       png_destroy_read_struct(&png_ptr, &info_ptr,
+          (png_infopp)NULL);
+       return (ERROR);
+    }
+    /* This one's new.  You can provide functions
+       to be called when the header info is valid,
+       when each row is completed, and when the image
+       is finished.  If you aren't using all functions,
+       you can specify NULL parameters.  Even when all
+       three functions are NULL, you need to call
+       png_set_progressive_read_fn().  You can use
+       any struct as the user_ptr (cast to a void pointer
+       for the function call), and retrieve the pointer
+       from inside the callbacks using the function
+          png_get_progressive_ptr(png_ptr);
+       which will return a void pointer, which you have
+       to cast appropriately.
+     */
+    png_set_progressive_read_fn(png_ptr, (void *)user_ptr,
+        info_callback, row_callback, end_callback);
+    return 0;
+ }
+ /* A code fragment that you call as you receive blocks
+   of data */
+ int
+ process_data(png_bytep buffer, png_uint_32 length)
+ {
+    if (setjmp(png_jmpbuf(png_ptr)))
+    {
+       png_destroy_read_struct(&png_ptr, &info_ptr,
+           (png_infopp)NULL);
+       return (ERROR);
+    }
+    /* This one's new also.  Simply give it a chunk
+       of data from the file stream (in order, of
+       course).  On machines with segmented memory
+       models machines, don't give it any more than
+       64K.  The library seems to run fine with sizes
+       of 4K. Although you can give it much less if
+       necessary (I assume you can give it chunks of
+       1 byte, I haven't tried less then 256 bytes
+       yet).  When this function returns, you may
+       want to display any rows that were generated
+       in the row callback if you don't already do
+       so there.
+     */
+    png_process_data(png_ptr, info_ptr, buffer, length);
+    /* At this point you can call png_process_data_skip if
+       you want to handle data the library will skip yourself;
+       it simply returns the number of bytes to skip (and stops
+       libpng skipping that number of bytes on the next
+       png_process_data call).
+    return 0;
+ }
+ /* This function is called (as set by
+    png_set_progressive_read_fn() above) when enough data
+    has been supplied so all of the header has been
+    read.
+ */
+ void
+ info_callback(png_structp png_ptr, png_infop info)
+ {
+    /* Do any setup here, including setting any of
+       the transformations mentioned in the Reading
+       PNG files section.  For now, you _must_ call
+       either png_start_read_image() or
+       png_read_update_info() after all the
+       transformations are set (even if you don't set
+       any).  You may start getting rows before
+       png_process_data() returns, so this is your
+       last chance to prepare for that.
+       This is where you turn on interlace handling,
+       assuming you don't want to do it yourself.
+       If you need to you can stop the processing of
+       your original input data at this point by calling
+       png_process_data_pause.  This returns the number
+       of unprocessed bytes from the last png_process_data
+       call - it is up to you to ensure that the next call
+       sees these bytes again.  If you don't want to bother
+       with this you can get libpng to cache the unread
+       bytes by setting the 'save' parameter (see png.h) but
+       then libpng will have to copy the data internally.
+     */
+ }
+ /* This function is called when each row of image
+    data is complete */
+ void
+ row_callback(png_structp png_ptr, png_bytep new_row,
+    png_uint_32 row_num, int pass)
+ {
+    /* If the image is interlaced, and you turned
+       on the interlace handler, this function will
+       be called for every row in every pass.  Some
+       of these rows will not be changed from the
+       previous pass.  When the row is not changed,
+       the new_row variable will be NULL.  The rows
+       and passes are called in order, so you don't
+       really need the row_num and pass, but I'm
+       supplying them because it may make your life
+       easier.
+       If you did not turn on interlace handling then
+       the callback is called for each row of each
+       sub-image when the image is interlaced.  In this
+       case 'row_num' is the row in the sub-image, not
+       the row in the output image as it is in all other
+       cases.
+       For the non-NULL rows of interlaced images when
+       you have switched on libpng interlace handling,
+       you must call png_progressive_combine_row()
+       passing in the row and the old row.  You can
+       call this function for NULL rows (it will just
+       return) and for non-interlaced images (it just
+       does the memcpy for you) if it will make the
+       code easier.  Thus, you can just do this for
+       all cases if you switch on interlace handling;
+     */
+        png_progressive_combine_row(png_ptr, old_row,
+          new_row);
+    /* where old_row is what was displayed for
+       previously for the row.  Note that the first
+       pass (pass == 0, really) will completely cover
+       the old row, so the rows do not have to be
+       initialized.  After the first pass (and only
+       for interlaced images), you will have to pass
+       the current row, and the function will combine
+       the old row and the new row.
+       You can also call png_process_data_pause in this
+       callback - see above.
+    */
+ }
+ void
+ end_callback(png_structp png_ptr, png_infop info)
+ {
+    /* This function is called after the whole image
+       has been read, including any chunks after the
+       image (up to and including the IEND).  You
+       will usually have the same info chunk as you
+       had in the header, although some data may have
+       been added to the comments and time fields.
+       Most people won't do much here, perhaps setting
+       a flag that marks the image as finished.
+     */
+ }
+.SH IV. Writing
+Much of this is very similar to reading.  However, everything of
+importance is repeated here, so you won't have to constantly look
+back up in the reading section to understand writing.
+.SS Setup
+You will want to do the I/O initialization before you get into libpng,
+so if it doesn't work, you don't have anything to undo. If you are not
+using the standard I/O functions, you will need to replace them with
+custom writing functions.  See the discussion under Customizing libpng.
+    FILE *fp = fopen(file_name, "wb");
+    if (!fp)
+       return (ERROR);
+Next, png_struct and png_info need to be allocated and initialized.
+As these can be both relatively large, you may not want to store these
+on the stack, unless you have stack space to spare.  Of course, you
+will want to check if they return NULL.  If you are also reading,
+you won't want to name your read structure and your write structure
+both "png_ptr"; you can call them anything you like, such as
+"read_ptr" and "write_ptr".  Look at pngtest.c, for example.
+    png_structp png_ptr = png_create_write_struct
+       (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
+        user_error_fn, user_warning_fn);
+    if (!png_ptr)
+       return (ERROR);
+    png_infop info_ptr = png_create_info_struct(png_ptr);
+    if (!info_ptr)
+    {
+       png_destroy_write_struct(&png_ptr,
+           (png_infopp)NULL);
+       return (ERROR);
+    }
+If you want to use your own memory allocation routines,
+define PNG_USER_MEM_SUPPORTED and use
+png_create_write_struct_2() instead of png_create_write_struct():
+    png_structp png_ptr = png_create_write_struct_2
+       (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
+        user_error_fn, user_warning_fn, (png_voidp)
+        user_mem_ptr, user_malloc_fn, user_free_fn);
+After you have these structures, you will need to set up the
+error handling.  When libpng encounters an error, it expects to
+longjmp() back to your routine.  Therefore, you will need to call
+setjmp() and pass the png_jmpbuf(png_ptr).  If you
+write the file from different routines, you will need to update
+the png_jmpbuf(png_ptr) every time you enter a new routine that will
+call a png_*() function.  See your documentation of setjmp/longjmp
+for your compiler for more information on setjmp/longjmp.  See
+the discussion on libpng error handling in the Customizing Libpng
+section below for more information on the libpng error handling.
+    if (setjmp(png_jmpbuf(png_ptr)))
+    {
+    png_destroy_write_struct(&png_ptr, &info_ptr);
+       fclose(fp);
+       return (ERROR);
+    }
+    ...
+    return;
+If you would rather avoid the complexity of setjmp/longjmp issues,
+you can compile libpng with PNG_NO_SETJMP, in which case
+errors will result in a call to PNG_ABORT() which defaults to abort().
+You can #define PNG_ABORT() to a function that does something
+more useful than abort(), as long as your function does not
+return.
+Now you need to set up the output code.  The default for libpng is to
+use the C function fwrite().  If you use this, you will need to pass a
+valid FILE * in the function png_init_io().  Be sure that the file is
+opened in binary mode.  Again, if you wish to handle writing data in
+another way, see the discussion on libpng I/O handling in the Customizing
+Libpng section below.
+    png_init_io(png_ptr, fp);
+If you are embedding your PNG into a datastream such as MNG, and don't
+want libpng to write the 8-byte signature, or if you have already
+written the signature in your application, use
+    png_set_sig_bytes(png_ptr, 8);
+to inform libpng that it should not write a signature.
+.SS Write callbacks
+At this point, you can set up a callback function that will be
+called after each row has been written, which you can use to control
+a progress meter or the like.  It's demonstrated in pngtest.c.
+You must supply a function
+    void write_row_callback(png_structp png_ptr, png_uint_32 row,
+       int pass);
+    {
+      /* put your code here */
+    }
+(You can give it another name that you like instead of "write_row_callback")
+To inform libpng about your function, use
+    png_set_write_status_fn(png_ptr, write_row_callback);
+When this function is called the row has already been completely processed and
+it has also been written out.  The 'row' and 'pass' refer to the next row to be
+handled.  For the
+non-interlaced case the row that was just handled is simply one less than the
+passed in row number, and pass will always be 0.  For the interlaced case the
+same applies unless the row value is 0, in which case the row just handled was
+the last one from one of the preceding passes.  Because interlacing may skip a
+pass you cannot be sure that the preceding pass is just 'pass-1', if you really
+need to know what the last pass is record (row,pass) from the callback and use
+the last recorded value each time.
+As with the user transform you can find the output row using the
+PNG_ROW_FROM_PASS_ROW macro.
+You now have the option of modifying how the compression library will
+run.  The following functions are mainly for testing, but may be useful
+in some cases, like if you need to write PNG files extremely fast and
+are willing to give up some compression, or if you want to get the
+maximum possible compression at the expense of slower writing.  If you
+have no special needs in this area, let the library do what it wants by
+not calling this function at all, as it has been tuned to deliver a good
+speed/compression ratio. The second parameter to png_set_filter() is
+the filter method, for which the only valid values are 0 (as of the
+July 1999 PNG specification, version 1.2) or 64 (if you are writing
+a PNG datastream that is to be embedded in a MNG datastream).  The third
+parameter is a flag that indicates which filter type(s) are to be tested
+for each scanline.  See the PNG specification for details on the specific
+filter types.
+    /* turn on or off filtering, and/or choose
+       specific filters.  You can use either a single
+       PNG_FILTER_VALUE_NAME or the bitwise OR of one
+       or more PNG_FILTER_NAME masks.
+     */
+    png_set_filter(png_ptr, 0,
+       PNG_FILTER_NONE  | PNG_FILTER_VALUE_NONE |
+       PNG_FILTER_SUB   | PNG_FILTER_VALUE_SUB  |
+       PNG_FILTER_UP    | PNG_FILTER_VALUE_UP   |
+       PNG_FILTER_AVG   | PNG_FILTER_VALUE_AVG  |
+       PNG_FILTER_PAETH | PNG_FILTER_VALUE_PAETH|
+       PNG_ALL_FILTERS);
+If an application wants to start and stop using particular filters during
+compression, it should start out with all of the filters (to ensure that
+the previous row of pixels will be stored in case it's needed later),
+and then add and remove them after the start of compression.
+If you are writing a PNG datastream that is to be embedded in a MNG
+datastream, the second parameter can be either 0 or 64.
+The png_set_compression_*() functions interface to the zlib compression
+library, and should mostly be ignored unless you really know what you are
+doing.  The only generally useful call is png_set_compression_level()
+which changes how much time zlib spends on trying to compress the image
+data.  See the Compression Library (zlib.h and algorithm.txt, distributed
+with zlib) for details on the compression levels.
+    #include zlib.h
+    /* Set the zlib compression level */
+    png_set_compression_level(png_ptr,
+        Z_BEST_COMPRESSION);
+    /* Set other zlib parameters for compressing IDAT */
+    png_set_compression_mem_level(png_ptr, 8);
+    png_set_compression_strategy(png_ptr,
+        Z_DEFAULT_STRATEGY);
+    png_set_compression_window_bits(png_ptr, 15);
+    png_set_compression_method(png_ptr, 8);
+    png_set_compression_buffer_size(png_ptr, 8192)
+    /* Set zlib parameters for text compression
+     * If you don't call these, the parameters
+     * fall back on those defined for IDAT chunks
+     */
+    png_set_text_compression_mem_level(png_ptr, 8);
+    png_set_text_compression_strategy(png_ptr,
+        Z_DEFAULT_STRATEGY);
+    png_set_text_compression_window_bits(png_ptr, 15);
+    png_set_text_compression_method(png_ptr, 8);
+.SS Setting the contents of info for output
+You now need to fill in the png_info structure with all the data you
+wish to write before the actual image.  Note that the only thing you
+are allowed to write after the image is the text chunks and the time
+chunk (as of PNG Specification 1.2, anyway).  See png_write_end() and
+the latest PNG specification for more information on that.  If you
+wish to write them before the image, fill them in now, and flag that
+data as being valid.  If you want to wait until after the data, don't
+fill them until png_write_end().  For all the fields in png_info and
+their data types, see png.h.  For explanations of what the fields
+contain, see the PNG specification.
+Some of the more important parts of the png_info are:
+    png_set_IHDR(png_ptr, info_ptr, width, height,
+       bit_depth, color_type, interlace_type,
+       compression_type, filter_method)
+    width          - holds the width of the image
+                     in pixels (up to 2^31).
+    height         - holds the height of the image
+                     in pixels (up to 2^31).
+    bit_depth      - holds the bit depth of one of the
+                     image channels.
+                     (valid values are 1, 2, 4, 8, 16
+                     and depend also on the
+                     color_type.  See also significant
+                     bits (sBIT) below).
+    color_type     - describes which color/alpha
+                     channels are present.
+                     PNG_COLOR_TYPE_GRAY
+                        (bit depths 1, 2, 4, 8, 16)
+                     PNG_COLOR_TYPE_GRAY_ALPHA
+                        (bit depths 8, 16)
+                     PNG_COLOR_TYPE_PALETTE
+                        (bit depths 1, 2, 4, 8)
+                     PNG_COLOR_TYPE_RGB
+                        (bit_depths 8, 16)
+                     PNG_COLOR_TYPE_RGB_ALPHA
+                        (bit_depths 8, 16)
+                     PNG_COLOR_MASK_PALETTE
+                     PNG_COLOR_MASK_COLOR
+                     PNG_COLOR_MASK_ALPHA
+    interlace_type - PNG_INTERLACE_NONE or
+                     PNG_INTERLACE_ADAM7
+    compression_type - (must be
+                     PNG_COMPRESSION_TYPE_DEFAULT)
+    filter_method  - (must be PNG_FILTER_TYPE_DEFAULT
+                     or, if you are writing a PNG to
+                     be embedded in a MNG datastream,
+                     can also be
+                     PNG_INTRAPIXEL_DIFFERENCING)
+If you call png_set_IHDR(), the call must appear before any of the
+other png_set_*() functions, because they might require access to some of
+the IHDR settings.  The remaining png_set_*() functions can be called
+in any order.
+If you wish, you can reset the compression_type, interlace_type, or
+filter_method later by calling png_set_IHDR() again; if you do this, the
+width, height, bit_depth, and color_type must be the same in each call.
+    png_set_PLTE(png_ptr, info_ptr, palette,
+       num_palette);
+    palette        - the palette for the file
+                     (array of png_color)
+    num_palette    - number of entries in the palette
+    png_set_gAMA(png_ptr, info_ptr, file_gamma);
+    png_set_gAMA_fixed(png_ptr, info_ptr, int_file_gamma);
+    file_gamma     - the gamma at which the image was
+                     created (PNG_INFO_gAMA)
+    int_file_gamma - 100,000 times the gamma at which
+                     the image was created
+    png_set_cHRM(png_ptr, info_ptr,  white_x, white_y, red_x, red_y,
+                     green_x, green_y, blue_x, blue_y)
+    png_set_cHRM_XYZ(png_ptr, info_ptr, red_X, red_Y, red_Z, green_X,
+                     green_Y, green_Z, blue_X, blue_Y, blue_Z)
+    png_set_cHRM_fixed(png_ptr, info_ptr, int_white_x, int_white_y,
+                     int_red_x, int_red_y, int_green_x, int_green_y,
+                     int_blue_x, int_blue_y)
+    png_set_cHRM_XYZ_fixed(png_ptr, info_ptr, int_red_X, int_red_Y,
+                     int_red_Z, int_green_X, int_green_Y, int_green_Z,
+                     int_blue_X, int_blue_Y, int_blue_Z)
+    {white,red,green,blue}_{x,y}
+                     A color space encoding specified using the chromaticities
+                     of the end points and the white point.
+    {red,green,blue}_{X,Y,Z}
+                     A color space encoding specified using the encoding end
+                     points - the CIE tristimulus specification of the intended
+                     color of the red, green and blue channels in the PNG RGB
+                     data.  The white point is simply the sum of the three end
+                     points.
+    png_set_sRGB(png_ptr, info_ptr, srgb_intent);
+    srgb_intent    - the rendering intent
+                     (PNG_INFO_sRGB) The presence of
+                     the sRGB chunk means that the pixel
+                     data is in the sRGB color space.
+                     This chunk also implies specific
+                     values of gAMA and cHRM.  Rendering
+                     intent is the CSS-1 property that
+                     has been defined by the International
+                     Color Consortium
+                     (http://www.color.org).
+                     It can be one of
+                     PNG_sRGB_INTENT_SATURATION,
+                     PNG_sRGB_INTENT_PERCEPTUAL,
+                     PNG_sRGB_INTENT_ABSOLUTE, or
+                     PNG_sRGB_INTENT_RELATIVE.
+    png_set_sRGB_gAMA_and_cHRM(png_ptr, info_ptr,
+       srgb_intent);
+    srgb_intent    - the rendering intent
+                     (PNG_INFO_sRGB) The presence of the
+                     sRGB chunk means that the pixel
+                     data is in the sRGB color space.
+                     This function also causes gAMA and
+                     cHRM chunks with the specific values
+                     that are consistent with sRGB to be
+                     written.
+    png_set_iCCP(png_ptr, info_ptr, name, compression_type,
+                       profile, proflen);
+    name             - The profile name.
+    compression_type - The compression type; always
+                       PNG_COMPRESSION_TYPE_BASE for PNG 1.0.
+                       You may give NULL to this argument to
+                       ignore it.
+    profile          - International Color Consortium color
+                       profile data. May contain NULs.
+    proflen          - length of profile data in bytes.
+    png_set_sBIT(png_ptr, info_ptr, sig_bit);
+    sig_bit        - the number of significant bits for
+                     (PNG_INFO_sBIT) each of the gray, red,
+                     green, and blue channels, whichever are
+                     appropriate for the given color type
+                     (png_color_16)
+    png_set_tRNS(png_ptr, info_ptr, trans_alpha,
+       num_trans, trans_color);
+    trans_alpha    - array of alpha (transparency)
+                     entries for palette (PNG_INFO_tRNS)
+    num_trans      - number of transparent entries
+                     (PNG_INFO_tRNS)
+    trans_color    - graylevel or color sample values
+                     (in order red, green, blue) of the
+                     single transparent color for
+                     non-paletted images (PNG_INFO_tRNS)
+    png_set_hIST(png_ptr, info_ptr, hist);
+    hist           - histogram of palette (array of
+                     png_uint_16) (PNG_INFO_hIST)
+    png_set_tIME(png_ptr, info_ptr, mod_time);
+    mod_time       - time image was last modified
+                     (PNG_VALID_tIME)
+    png_set_bKGD(png_ptr, info_ptr, background);
+    background     - background color (of type
+                     png_color_16p) (PNG_VALID_bKGD)
+    png_set_text(png_ptr, info_ptr, text_ptr, num_text);
+    text_ptr       - array of png_text holding image
+                     comments
+    text_ptr[i].compression - type of compression used
+                 on "text" PNG_TEXT_COMPRESSION_NONE
+                           PNG_TEXT_COMPRESSION_zTXt
+                           PNG_ITXT_COMPRESSION_NONE
+                           PNG_ITXT_COMPRESSION_zTXt
+    text_ptr[i].key   - keyword for comment.  Must contain
+                 1-79 characters.
+    text_ptr[i].text  - text comments for current
+                         keyword.  Can be NULL or empty.
+    text_ptr[i].text_length - length of text string,
+                 after decompression, 0 for iTXt
+    text_ptr[i].itxt_length - length of itxt string,
+                 after decompression, 0 for tEXt/zTXt
+    text_ptr[i].lang  - language of comment (NULL or
+                         empty for unknown).
+    text_ptr[i].translated_keyword  - keyword in UTF-8 (NULL
+                         or empty for unknown).
+    Note that the itxt_length, lang, and lang_key
+    members of the text_ptr structure only exist when the
+    library is built with iTXt chunk support.  Prior to
+    libpng-1.4.0 the library was built by default without
+    iTXt support. Also note that when iTXt is supported,
+    they contain NULL pointers when the "compression"
+    field contains PNG_TEXT_COMPRESSION_NONE or
+    PNG_TEXT_COMPRESSION_zTXt.
+    num_text       - number of comments
+    png_set_sPLT(png_ptr, info_ptr, &palette_ptr,
+       num_spalettes);
+    palette_ptr    - array of png_sPLT_struct structures
+                     to be added to the list of palettes
+                     in the info structure.
+    num_spalettes  - number of palette structures to be
+                     added.
+    png_set_oFFs(png_ptr, info_ptr, offset_x, offset_y,
+        unit_type);
+    offset_x  - positive offset from the left
+                     edge of the screen
+    offset_y  - positive offset from the top
+                     edge of the screen
+    unit_type - PNG_OFFSET_PIXEL, PNG_OFFSET_MICROMETER
+    png_set_pHYs(png_ptr, info_ptr, res_x, res_y,
+        unit_type);
+    res_x       - pixels/unit physical resolution
+                  in x direction
+    res_y       - pixels/unit physical resolution
+                  in y direction
+    unit_type   - PNG_RESOLUTION_UNKNOWN,
+                  PNG_RESOLUTION_METER
+    png_set_sCAL(png_ptr, info_ptr, unit, width, height)
+    unit        - physical scale units (an integer)
+    width       - width of a pixel in physical scale units
+    height      - height of a pixel in physical scale units
+                  (width and height are doubles)
+    png_set_sCAL_s(png_ptr, info_ptr, unit, width, height)
+    unit        - physical scale units (an integer)
+    width       - width of a pixel in physical scale units
+                  expressed as a string
+    height      - height of a pixel in physical scale units
+                 (width and height are strings like "2.54")
+    png_set_unknown_chunks(png_ptr, info_ptr, &unknowns,
+       num_unknowns)
+    unknowns          - array of png_unknown_chunk
+                        structures holding unknown chunks
+    unknowns[i].name  - name of unknown chunk
+    unknowns[i].data  - data of unknown chunk
+    unknowns[i].size  - size of unknown chunk's data
+    unknowns[i].location - position to write chunk in file
+                           0: do not write chunk
+                           PNG_HAVE_IHDR: before PLTE
+                           PNG_HAVE_PLTE: before IDAT
+                           PNG_AFTER_IDAT: after IDAT
+The "location" member is set automatically according to
+what part of the output file has already been written.
+You can change its value after calling png_set_unknown_chunks()
+as demonstrated in pngtest.c.  Within each of the "locations",
+the chunks are sequenced according to their position in the
+structure (that is, the value of "i", which is the order in which
+the chunk was either read from the input file or defined with
+png_set_unknown_chunks).
+A quick word about text and num_text.  text is an array of png_text
+structures.  num_text is the number of valid structures in the array.
+Each png_text structure holds a language code, a keyword, a text value,
+and a compression type.
+The compression types have the same valid numbers as the compression
+types of the image data.  Currently, the only valid number is zero.
+However, you can store text either compressed or uncompressed, unlike
+images, which always have to be compressed.  So if you don't want the
+text compressed, set the compression type to PNG_TEXT_COMPRESSION_NONE.
+Because tEXt and zTXt chunks don't have a language field, if you
+specify PNG_TEXT_COMPRESSION_NONE or PNG_TEXT_COMPRESSION_zTXt
+any language code or translated keyword will not be written out.
+Until text gets around a few hundred bytes, it is not worth compressing it.
+After the text has been written out to the file, the compression type
+is set to PNG_TEXT_COMPRESSION_NONE_WR or PNG_TEXT_COMPRESSION_zTXt_WR,
+so that it isn't written out again at the end (in case you are calling
+png_write_end() with the same struct).
+The keywords that are given in the PNG Specification are:
+    Title            Short (one line) title or
+                     caption for image
+    Author           Name of image's creator
+    Description      Description of image (possibly long)
+    Copyright        Copyright notice
+    Creation Time    Time of original image creation
+                     (usually RFC 1123 format, see below)
+    Software         Software used to create the image
+    Disclaimer       Legal disclaimer
+    Warning          Warning of nature of content
+    Source           Device used to create the image
+    Comment          Miscellaneous comment; conversion
+                     from other image format
+The keyword-text pairs work like this.  Keywords should be short
+simple descriptions of what the comment is about.  Some typical
+keywords are found in the PNG specification, as is some recommendations
+on keywords.  You can repeat keywords in a file.  You can even write
+some text before the image and some after.  For example, you may want
+to put a description of the image before the image, but leave the
+disclaimer until after, so viewers working over modem connections
+don't have to wait for the disclaimer to go over the modem before
+they start seeing the image.  Finally, keywords should be full
+words, not abbreviations.  Keywords and text are in the ISO 8859-1
+(Latin-1) character set (a superset of regular ASCII) and can not
+contain NUL characters, and should not contain control or other
+unprintable characters.  To make the comments widely readable, stick
+with basic ASCII, and avoid machine specific character set extensions
+like the IBM-PC character set.  The keyword must be present, but
+you can leave off the text string on non-compressed pairs.
+Compressed pairs must have a text string, as only the text string
+is compressed anyway, so the compression would be meaningless.
+PNG supports modification time via the png_time structure.  Two
+conversion routines are provided, png_convert_from_time_t() for
+time_t and png_convert_from_struct_tm() for struct tm.  The
+time_t routine uses gmtime().  You don't have to use either of
+these, but if you wish to fill in the png_time structure directly,
+you should provide the time in universal time (GMT) if possible
+instead of your local time.  Note that the year number is the full
+year (e.g. 1998, rather than 98 - PNG is year 2000 compliant!), and
+that months start with 1.
+If you want to store the time of the original image creation, you should
+use a plain tEXt chunk with the "Creation Time" keyword.  This is
+necessary because the "creation time" of a PNG image is somewhat vague,
+depending on whether you mean the PNG file, the time the image was
+created in a non-PNG format, a still photo from which the image was
+scanned, or possibly the subject matter itself.  In order to facilitate
+machine-readable dates, it is recommended that the "Creation Time"
+tEXt chunk use RFC 1123 format dates (e.g. "22 May 1997 18:07:10 GMT"),
+although this isn't a requirement.  Unlike the tIME chunk, the
+"Creation Time" tEXt chunk is not expected to be automatically changed
+by the software.  To facilitate the use of RFC 1123 dates, a function
+png_convert_to_rfc1123(png_timep) is provided to convert from PNG
+time to an RFC 1123 format string.
+.SS Writing unknown chunks
+You can use the png_set_unknown_chunks function to queue up chunks
+for writing.  You give it a chunk name, raw data, and a size; that's
+all there is to it.  The chunks will be written by the next following
+png_write_info_before_PLTE, png_write_info, or png_write_end function.
+Any chunks previously read into the info structure's unknown-chunk
+list will also be written out in a sequence that satisfies the PNG
+specification's ordering rules.
+.SS The high-level write interface
+At this point there are two ways to proceed; through the high-level
+write interface, or through a sequence of low-level write operations.
+You can use the high-level interface if your image data is present
+in the info structure.  All defined output
+transformations are permitted, enabled by the following masks.
+    PNG_TRANSFORM_IDENTITY      No transformation
+    PNG_TRANSFORM_PACKING       Pack 1, 2 and 4-bit samples
+    PNG_TRANSFORM_PACKSWAP      Change order of packed
+                                pixels to LSB first
+    PNG_TRANSFORM_INVERT_MONO   Invert monochrome images
+    PNG_TRANSFORM_SHIFT         Normalize pixels to the
+                                sBIT depth
+    PNG_TRANSFORM_BGR           Flip RGB to BGR, RGBA
+                                to BGRA
+    PNG_TRANSFORM_SWAP_ALPHA    Flip RGBA to ARGB or GA
+                                to AG
+    PNG_TRANSFORM_INVERT_ALPHA  Change alpha from opacity
+                                to transparency
+    PNG_TRANSFORM_SWAP_ENDIAN   Byte-swap 16-bit samples
+    PNG_TRANSFORM_STRIP_FILLER        Strip out filler
+                                      bytes (deprecated).
+    PNG_TRANSFORM_STRIP_FILLER_BEFORE Strip out leading
+                                      filler bytes
+    PNG_TRANSFORM_STRIP_FILLER_AFTER  Strip out trailing
+                                      filler bytes
+If you have valid image data in the info structure (you can use
+png_set_rows() to put image data in the info structure), simply do this:
+    png_write_png(png_ptr, info_ptr, png_transforms, NULL)
+where png_transforms is an integer containing the bitwise OR of some set of
+transformation flags.  This call is equivalent to png_write_info(),
+followed the set of transformations indicated by the transform mask,
+then png_write_image(), and finally png_write_end().
+(The final parameter of this call is not yet used.  Someday it might point
+to transformation parameters required by some future output transform.)
+You must use png_transforms and not call any png_set_transform() functions
+when you use png_write_png().
+.SS The low-level write interface
+If you are going the low-level route instead, you are now ready to
+write all the file information up to the actual image data.  You do
+this with a call to png_write_info().
+    png_write_info(png_ptr, info_ptr);
+Note that there is one transformation you may need to do before
+png_write_info().  In PNG files, the alpha channel in an image is the
+level of opacity.  If your data is supplied as a level of transparency,
+you can invert the alpha channel before you write it, so that 0 is
+fully transparent and 255 (in 8-bit or paletted images) or 65535
+(in 16-bit images) is fully opaque, with
+    png_set_invert_alpha(png_ptr);
+This must appear before png_write_info() instead of later with the
+other transformations because in the case of paletted images the tRNS
+chunk data has to be inverted before the tRNS chunk is written.  If
+your image is not a paletted image, the tRNS data (which in such cases
+represents a single color to be rendered as transparent) won't need to
+be changed, and you can safely do this transformation after your
+png_write_info() call.
+If you need to write a private chunk that you want to appear before
+the PLTE chunk when PLTE is present, you can write the PNG info in
+two steps, and insert code to write your own chunk between them:
+    png_write_info_before_PLTE(png_ptr, info_ptr);
+    png_set_unknown_chunks(png_ptr, info_ptr, ...);
+    png_write_info(png_ptr, info_ptr);
+After you've written the file information, you can set up the library
+to handle any special transformations of the image data.  The various
+ways to transform the data will be described in the order that they
+should occur.  This is important, as some of these change the color
+type and/or bit depth of the data, and some others only work on
+certain color types and bit depths.  Even though each transformation
+checks to see if it has data that it can do something with, you should
+make sure to only enable a transformation if it will be valid for the
+data.  For example, don't swap red and blue on grayscale data.
+PNG files store RGB pixels packed into 3 or 6 bytes.  This code tells
+the library to strip input data that has 4 or 8 bytes per pixel down
+to 3 or 6 bytes (or strip 2 or 4-byte grayscale+filler data to 1 or 2
+bytes per pixel).
+    png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE);
+where the 0 is unused, and the location is either PNG_FILLER_BEFORE or
+PNG_FILLER_AFTER, depending upon whether the filler byte in the pixel
+is stored XRGB or RGBX.
+PNG files pack pixels of bit depths 1, 2, and 4 into bytes as small as
+they can, resulting in, for example, 8 pixels per byte for 1 bit files.
+If the data is supplied at 1 pixel per byte, use this code, which will
+correctly pack the pixels into a single byte:
+    png_set_packing(png_ptr);
+PNG files reduce possible bit depths to 1, 2, 4, 8, and 16.  If your
+data is of another bit depth, you can write an sBIT chunk into the
+file so that decoders can recover the original data if desired.
+    /* Set the true bit depth of the image data */
+    if (color_type & PNG_COLOR_MASK_COLOR)
+    {
+       sig_bit.red = true_bit_depth;
+       sig_bit.green = true_bit_depth;
+       sig_bit.blue = true_bit_depth;
+    }
+    else
+    {
+       sig_bit.gray = true_bit_depth;
+    }
+    if (color_type & PNG_COLOR_MASK_ALPHA)
+    {
+       sig_bit.alpha = true_bit_depth;
+    }
+    png_set_sBIT(png_ptr, info_ptr, &sig_bit);
+If the data is stored in the row buffer in a bit depth other than
+one supported by PNG (e.g. 3 bit data in the range 0-7 for a 4-bit PNG),
+this will scale the values to appear to be the correct bit depth as
+is required by PNG.
+    png_set_shift(png_ptr, &sig_bit);
+PNG files store 16-bit pixels in network byte order (big-endian,
+ie. most significant bits first).  This code would be used if they are
+supplied the other way (little-endian, i.e. least significant bits
+first, the way PCs store them):
+    if (bit_depth > 8)
+       png_set_swap(png_ptr);
+If you are using packed-pixel images (1, 2, or 4 bits/pixel), and you
+need to change the order the pixels are packed into bytes, you can use:
+    if (bit_depth < 8)
+       png_set_packswap(png_ptr);
+PNG files store 3 color pixels in red, green, blue order.  This code
+would be used if they are supplied as blue, green, red:
+    png_set_bgr(png_ptr);
+PNG files describe monochrome as black being zero and white being
+one. This code would be used if the pixels are supplied with this reversed
+(black being one and white being zero):
+    png_set_invert_mono(png_ptr);
+Finally, you can write your own transformation function if none of
+the existing ones meets your needs.  This is done by setting a callback
+with
+    png_set_write_user_transform_fn(png_ptr,
+       write_transform_fn);
+You must supply the function
+    void write_transform_fn(png_structp png_ptr, png_row_infop
+       row_info, png_bytep data)
+See pngtest.c for a working example.  Your function will be called
+before any of the other transformations are processed.  If supported
+libpng also supplies an information routine that may be called from
+your callback:
+   png_get_current_row_number(png_ptr);
+   png_get_current_pass_number(png_ptr);
+This returns the current row passed to the transform.  With interlaced
+images the value returned is the row in the input sub-image image.  Use
+PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
+find the output pixel (x,y) given an interlaced sub-image pixel (row,col,pass).
+The discussion of interlace handling above contains more information on how to
+use these values.
+You can also set up a pointer to a user structure for use by your
+callback function.
+    png_set_user_transform_info(png_ptr, user_ptr, 0, 0);
+The user_channels and user_depth parameters of this function are ignored
+when writing; you can set them to zero as shown.
+You can retrieve the pointer via the function png_get_user_transform_ptr().
+For example:
+    voidp write_user_transform_ptr =
+       png_get_user_transform_ptr(png_ptr);
+It is possible to have libpng flush any pending output, either manually,
+or automatically after a certain number of lines have been written.  To
+flush the output stream a single time call:
+    png_write_flush(png_ptr);
+and to have libpng flush the output stream periodically after a certain
+number of scanlines have been written, call:
+    png_set_flush(png_ptr, nrows);
+Note that the distance between rows is from the last time png_write_flush()
+was called, or the first row of the image if it has never been called.
+So if you write 50 lines, and then png_set_flush 25, it will flush the
+output on the next scanline, and every 25 lines thereafter, unless
+png_write_flush() is called before 25 more lines have been written.
+If nrows is too small (less than about 10 lines for a 640 pixel wide
+RGB image) the image compression may decrease noticeably (although this
+may be acceptable for real-time applications).  Infrequent flushing will
+only degrade the compression performance by a few percent over images
+that do not use flushing.
+.SS Writing the image data
+That's it for the transformations.  Now you can write the image data.
+The simplest way to do this is in one function call.  If you have the
+whole image in memory, you can just call png_write_image() and libpng
+will write the image.  You will need to pass in an array of pointers to
+each row.  This function automatically handles interlacing, so you don't
+need to call png_set_interlace_handling() or call this function multiple
+times, or any of that other stuff necessary with png_write_rows().
+    png_write_image(png_ptr, row_pointers);
+where row_pointers is:
+    png_byte *row_pointers[height];
+You can point to void or char or whatever you use for pixels.
+If you don't want to write the whole image at once, you can
+use png_write_rows() instead.  If the file is not interlaced,
+this is simple:
+    png_write_rows(png_ptr, row_pointers,
+       number_of_rows);
+row_pointers is the same as in the png_write_image() call.
+If you are just writing one row at a time, you can do this with
+a single row_pointer instead of an array of row_pointers:
+    png_bytep row_pointer = row;
+    png_write_row(png_ptr, row_pointer);
+When the file is interlaced, things can get a good deal more complicated.
+The only currently (as of the PNG Specification version 1.2, dated July
+1999) defined interlacing scheme for PNG files is the "Adam7" interlace
+scheme, that breaks down an image into seven smaller images of varying
+size.  libpng will build these images for you, or you can do them
+yourself.  If you want to build them yourself, see the PNG specification
+for details of which pixels to write when.
+If you don't want libpng to handle the interlacing details, just
+use png_set_interlace_handling() and call png_write_rows() the
+correct number of times to write all the sub-images
+(png_set_interlace_handling() returns the number of sub-images.)
+If you want libpng to build the sub-images, call this before you start
+writing any rows:
+    number_of_passes = png_set_interlace_handling(png_ptr);
+This will return the number of passes needed.  Currently, this is seven,
+but may change if another interlace type is added.
+Then write the complete image number_of_passes times.
+    png_write_rows(png_ptr, row_pointers, number_of_rows);
+Think carefully before you write an interlaced image.  Typically code that
+reads such images reads all the image data into memory, uncompressed, before
+doing any processing.  Only code that can display an image on the fly can
+take advantage of the interlacing and even then the image has to be exactly
+the correct size for the output device, because scaling an image requires
+adjacent pixels and these are not available until all the passes have been
+read.
+If you do write an interlaced image you will hardly ever need to handle
+the interlacing yourself.  Call png_set_interlace_handling() and use the
+approach described above.
+The only time it is conceivable that you will really need to write an
+interlaced image pass-by-pass is when you have read one pass by pass and
+made some pixel-by-pixel transformation to it, as described in the read
+code above.  In this case use the PNG_PASS_ROWS and PNG_PASS_COLS macros
+to determine the size of each sub-image in turn and simply write the rows
+you obtained from the read code.
+.SS Finishing a sequential write
+After you are finished writing the image, you should finish writing
+the file.  If you are interested in writing comments or time, you should
+pass an appropriately filled png_info pointer.  If you are not interested,
+you can pass NULL.
+    png_write_end(png_ptr, info_ptr);
+When you are done, you can free all memory used by libpng like this:
+    png_destroy_write_struct(&png_ptr, &info_ptr);
+It is also possible to individually free the info_ptr members that
+point to libpng-allocated storage with the following function:
+    png_free_data(png_ptr, info_ptr, mask, seq)
+    mask  - identifies data to be freed, a mask
+            containing the bitwise OR of one or
+            more of
+              PNG_FREE_PLTE, PNG_FREE_TRNS,
+              PNG_FREE_HIST, PNG_FREE_ICCP,
+              PNG_FREE_PCAL, PNG_FREE_ROWS,
+              PNG_FREE_SCAL, PNG_FREE_SPLT,
+              PNG_FREE_TEXT, PNG_FREE_UNKN,
+            or simply PNG_FREE_ALL
+    seq   - sequence number of item to be freed
+            (-1 for all items)
+This function may be safely called when the relevant storage has
+already been freed, or has not yet been allocated, or was allocated
+by the user  and not by libpng,  and will in those cases do nothing.
+The "seq" parameter is ignored if only one item of the selected data
+type, such as PLTE, is allowed.  If "seq" is not -1, and multiple items
+are allowed for the data type identified in the mask, such as text or
+sPLT, only the n'th item in the structure is freed, where n is "seq".
+If you allocated data such as a palette that you passed in to libpng
+with png_set_*, you must not free it until just before the call to
+png_destroy_write_struct().
+The default behavior is only to free data that was allocated internally
+by libpng.  This can be changed, so that libpng will not free the data,
+or so that it will free data that was allocated by the user with png_malloc()
+or png_zalloc() and passed in via a png_set_*() function, with
+    png_data_freer(png_ptr, info_ptr, freer, mask)
+    freer  - one of
+               PNG_DESTROY_WILL_FREE_DATA
+               PNG_SET_WILL_FREE_DATA
+               PNG_USER_WILL_FREE_DATA
+    mask   - which data elements are affected
+             same choices as in png_free_data()
+For example, to transfer responsibility for some data from a read structure
+to a write structure, you could use
+    png_data_freer(read_ptr, read_info_ptr,
+       PNG_USER_WILL_FREE_DATA,
+       PNG_FREE_PLTE|PNG_FREE_tRNS|PNG_FREE_hIST)
+    png_data_freer(write_ptr, write_info_ptr,
+       PNG_DESTROY_WILL_FREE_DATA,
+       PNG_FREE_PLTE|PNG_FREE_tRNS|PNG_FREE_hIST)
+thereby briefly reassigning responsibility for freeing to the user but
+immediately afterwards reassigning it once more to the write_destroy
+function.  Having done this, it would then be safe to destroy the read
+structure and continue to use the PLTE, tRNS, and hIST data in the write
+structure.
+This function only affects data that has already been allocated.
+You can call this function before calling after the png_set_*() functions
+to control whether the user or png_destroy_*() is supposed to free the data.
+When the user assumes responsibility for libpng-allocated data, the
+application must use
+png_free() to free it, and when the user transfers responsibility to libpng
+for data that the user has allocated, the user must have used png_malloc()
+or png_zalloc() to allocate it.
+If you allocated text_ptr.text, text_ptr.lang, and text_ptr.translated_keyword
+separately, do not transfer responsibility for freeing text_ptr to libpng,
+because when libpng fills a png_text structure it combines these members with
+the key member, and png_free_data() will free only text_ptr.key.  Similarly,
+if you transfer responsibility for free'ing text_ptr from libpng to your
+application, your application must not separately free those members.
+For a more compact example of writing a PNG image, see the file example.c.
+.SH V. Modifying/Customizing libpng:
+There are two issues here.  The first is changing how libpng does
+standard things like memory allocation, input/output, and error handling.
+The second deals with more complicated things like adding new chunks,
+adding new transformations, and generally changing how libpng works.
+Both of those are compile-time issues; that is, they are generally
+determined at the time the code is written, and there is rarely a need
+to provide the user with a means of changing them.
+Memory allocation, input/output, and error handling
+All of the memory allocation, input/output, and error handling in libpng
+goes through callbacks that are user-settable.  The default routines are
+in pngmem.c, pngrio.c, pngwio.c, and pngerror.c, respectively.  To change
+these functions, call the appropriate png_set_*_fn() function.
+Memory allocation is done through the functions png_malloc(), png_calloc(),
+and png_free().  These currently just call the standard C functions.
+png_calloc() calls png_malloc() and then clears the newly
+allocated memory to zero.  There is limited support for certain systems
+with segmented memory architectures and the types of pointers declared by
+png.h match this; you will have to use appropriate pointers in your
+application.  Since it is
+unlikely that the method of handling memory allocation on a platform
+will change between applications, these functions must be modified in
+the library at compile time.  If you prefer to use a different method
+of allocating and freeing data, you can use png_create_read_struct_2() or
+png_create_write_struct_2() to register your own functions as described
+above.  These functions also provide a void pointer that can be retrieved
+via
+    mem_ptr=png_get_mem_ptr(png_ptr);
+Your replacement memory functions must have prototypes as follows:
+    png_voidp malloc_fn(png_structp png_ptr,
+       png_alloc_size_t size);
+    void free_fn(png_structp png_ptr, png_voidp ptr);
+Your malloc_fn() must return NULL in case of failure.  The png_malloc()
+function will normally call png_error() if it receives a NULL from the
+system memory allocator or from your replacement malloc_fn().
+Your free_fn() will never be called with a NULL ptr, since libpng's
+png_free() checks for NULL before calling free_fn().
+Input/Output in libpng is done through png_read() and png_write(),
+which currently just call fread() and fwrite().  The FILE * is stored in
+png_struct and is initialized via png_init_io().  If you wish to change
+the method of I/O, the library supplies callbacks that you can set
+through the function png_set_read_fn() and png_set_write_fn() at run
+time, instead of calling the png_init_io() function.  These functions
+also provide a void pointer that can be retrieved via the function
+png_get_io_ptr().  For example:
+    png_set_read_fn(png_structp read_ptr,
+        voidp read_io_ptr, png_rw_ptr read_data_fn)
+    png_set_write_fn(png_structp write_ptr,
+        voidp write_io_ptr, png_rw_ptr write_data_fn,
+        png_flush_ptr output_flush_fn);
+    voidp read_io_ptr = png_get_io_ptr(read_ptr);
+    voidp write_io_ptr = png_get_io_ptr(write_ptr);
+The replacement I/O functions must have prototypes as follows:
+    void user_read_data(png_structp png_ptr,
+        png_bytep data, png_size_t length);
+    void user_write_data(png_structp png_ptr,
+        png_bytep data, png_size_t length);
+    void user_flush_data(png_structp png_ptr);
+The user_read_data() function is responsible for detecting and
+handling end-of-data errors.
+Supplying NULL for the read, write, or flush functions sets them back
+to using the default C stream functions, which expect the io_ptr to
+point to a standard *FILE structure.  It is probably a mistake
+to use NULL for one of write_data_fn and output_flush_fn but not both
+of them, unless you have built libpng with PNG_NO_WRITE_FLUSH defined.
+It is an error to read from a write stream, and vice versa.
+Error handling in libpng is done through png_error() and png_warning().
+Errors handled through png_error() are fatal, meaning that png_error()
+should never return to its caller.  Currently, this is handled via
+setjmp() and longjmp() (unless you have compiled libpng with
+PNG_NO_SETJMP, in which case it is handled via PNG_ABORT()),
+but you could change this to do things like exit() if you should wish,
+as long as your function does not return.
+On non-fatal errors, png_warning() is called
+to print a warning message, and then control returns to the calling code.
+By default png_error() and png_warning() print a message on stderr via
+fprintf() unless the library is compiled with PNG_NO_CONSOLE_IO defined
+(because you don't want the messages) or PNG_NO_STDIO defined (because
+fprintf() isn't available).  If you wish to change the behavior of the error
+functions, you will need to set up your own message callbacks.  These
+functions are normally supplied at the time that the png_struct is created.
+It is also possible to redirect errors and warnings to your own replacement
+functions after png_create_*_struct() has been called by calling:
+    png_set_error_fn(png_structp png_ptr,
+        png_voidp error_ptr, png_error_ptr error_fn,
+        png_error_ptr warning_fn);
+    png_voidp error_ptr = png_get_error_ptr(png_ptr);
+If NULL is supplied for either error_fn or warning_fn, then the libpng
+default function will be used, calling fprintf() and/or longjmp() if a
+problem is encountered.  The replacement error functions should have
+parameters as follows:
+    void user_error_fn(png_structp png_ptr,
+        png_const_charp error_msg);
+    void user_warning_fn(png_structp png_ptr,
+        png_const_charp warning_msg);
+The motivation behind using setjmp() and longjmp() is the C++ throw and
+catch exception handling methods.  This makes the code much easier to write,
+as there is no need to check every return code of every function call.
+However, there are some uncertainties about the status of local variables
+after a longjmp, so the user may want to be careful about doing anything
+after setjmp returns non-zero besides returning itself.  Consult your
+compiler documentation for more details.  For an alternative approach, you
+may wish to use the "cexcept" facility (see http://cexcept.sourceforge.net),
+which is illustrated in pngvalid.c and in contrib/visupng.
+.SS Custom chunks
+If you need to read or write custom chunks, you may need to get deeper
+into the libpng code.  The library now has mechanisms for storing
+and writing chunks of unknown type; you can even declare callbacks
+for custom chunks.  However, this may not be good enough if the
+library code itself needs to know about interactions between your
+chunk and existing `intrinsic' chunks.
+If you need to write a new intrinsic chunk, first read the PNG
+specification. Acquire a first level of understanding of how it works.
+Pay particular attention to the sections that describe chunk names,
+and look at how other chunks were designed, so you can do things
+similarly.  Second, check out the sections of libpng that read and
+write chunks.  Try to find a chunk that is similar to yours and use
+it as a template.  More details can be found in the comments inside
+the code.  It is best to handle private or unknown chunks in a generic method,
+via callback functions, instead of by modifying libpng functions. This
+is illustrated in pngtest.c, which uses a callback function to handle a
+private "vpAg" chunk and the new "sTER" chunk, which are both unknown to
+libpng.
+If you wish to write your own transformation for the data, look through
+the part of the code that does the transformations, and check out some of
+the simpler ones to get an idea of how they work.  Try to find a similar
+transformation to the one you want to add and copy off of it.  More details
+can be found in the comments inside the code itself.
+.SS Configuring for 16-bit platforms
+You will want to look into zconf.h to tell zlib (and thus libpng) that
+it cannot allocate more then 64K at a time.  Even if you can, the memory
+won't be accessible.  So limit zlib and libpng to 64K by defining MAXSEG_64K.
+.SS Configuring for DOS
+For DOS users who only have access to the lower 640K, you will
+have to limit zlib's memory usage via a png_set_compression_mem_level()
+call.  See zlib.h or zconf.h in the zlib library for more information.
+.SS Configuring for Medium Model
+Libpng's support for medium model has been tested on most of the popular
+compilers.  Make sure MAXSEG_64K gets defined, USE_FAR_KEYWORD gets
+defined, and FAR gets defined to far in pngconf.h, and you should be
+all set.  Everything in the library (except for zlib's structure) is
+expecting far data.  You must use the typedefs with the p or pp on
+the end for pointers (or at least look at them and be careful).  Make
+note that the rows of data are defined as png_bytepp, which is
+an "unsigned char far * far *".
+.SS Configuring for gui/windowing platforms:
+You will need to write new error and warning functions that use the GUI
+interface, as described previously, and set them to be the error and
+warning functions at the time that png_create_*_struct() is called,
+in order to have them available during the structure initialization.
+They can be changed later via png_set_error_fn().  On some compilers,
+you may also have to change the memory allocators (png_malloc, etc.).
+.SS Configuring for compiler xxx:
+All includes for libpng are in pngconf.h.  If you need to add, change
+or delete an include, this is the place to do it.
+The includes that are not needed outside libpng are placed in pngpriv.h,
+which is only used by the routines inside libpng itself.
+The files in libpng proper only include pngpriv.h and png.h, which
+%14%in turn includes pngconf.h.
+in turn includes pngconf.h and, as of libpng-1.5.0, pnglibconf.h.
+As of libpng-1.5.0, pngpriv.h also includes three other private header
+files, pngstruct.h, pnginfo.h, and pngdebug.h, which contain material
+that previously appeared in the public headers.
+.SS Configuring zlib:
+There are special functions to configure the compression.  Perhaps the
+most useful one changes the compression level, which currently uses
+input compression values in the range 0 - 9.  The library normally
+uses the default compression level (Z_DEFAULT_COMPRESSION = 6).  Tests
+have shown that for a large majority of images, compression values in
+the range 3-6 compress nearly as well as higher levels, and do so much
+faster.  For online applications it may be desirable to have maximum speed
+(Z_BEST_SPEED = 1).  With versions of zlib after v0.99, you can also
+specify no compression (Z_NO_COMPRESSION = 0), but this would create
+files larger than just storing the raw bitmap.  You can specify the
+compression level by calling:
+    #include zlib.h
+    png_set_compression_level(png_ptr, level);
+Another useful one is to reduce the memory level used by the library.
+The memory level defaults to 8, but it can be lowered if you are
+short on memory (running DOS, for example, where you only have 640K).
+Note that the memory level does have an effect on compression; among
+other things, lower levels will result in sections of incompressible
+data being emitted in smaller stored blocks, with a correspondingly
+larger relative overhead of up to 15% in the worst case.
+    #include zlib.h
+    png_set_compression_mem_level(png_ptr, level);
+The other functions are for configuring zlib.  They are not recommended
+for normal use and may result in writing an invalid PNG file.  See
+zlib.h for more information on what these mean.
+    #include zlib.h
+    png_set_compression_strategy(png_ptr,
+        strategy);
+    png_set_compression_window_bits(png_ptr,
+        window_bits);
+    png_set_compression_method(png_ptr, method);
+    png_set_compression_buffer_size(png_ptr, size);
+As of libpng version 1.5.4, additional APIs became
+available to set these separately for non-IDAT
+compressed chunks such as zTXt, iTXt, and iCCP:
+    #include zlib.h
+    #if PNG_LIBPNG_VER <= 10504
+    png_set_text_compression_level(png_ptr, level);
+    png_set_text_compression_mem_level(png_ptr, level);
+    png_set_text_compression_strategy(png_ptr,
+        strategy);
+    png_set_text_compression_window_bits(png_ptr,
+        window_bits);
+    png_set_text_compression_method(png_ptr, method);
+    #endif
+.SS Controlling row filtering
+If you want to control whether libpng uses filtering or not, which
+filters are used, and how it goes about picking row filters, you
+can call one of these functions.  The selection and configuration
+of row filters can have a significant impact on the size and
+encoding speed and a somewhat lesser impact on the decoding speed
+of an image.  Filtering is enabled by default for RGB and grayscale
+images (with and without alpha), but not for paletted images nor
+for any images with bit depths less than 8 bits/pixel.
+The 'method' parameter sets the main filtering method, which is
+currently only '0' in the PNG 1.2 specification.  The 'filters'
+parameter sets which filter(s), if any, should be used for each
+scanline.  Possible values are PNG_ALL_FILTERS and PNG_NO_FILTERS
+to turn filtering on and off, respectively.
+Individual filter types are PNG_FILTER_NONE, PNG_FILTER_SUB,
+PNG_FILTER_UP, PNG_FILTER_AVG, PNG_FILTER_PAETH, which can be bitwise
+ORed together with '|' to specify one or more filters to use.
+These filters are described in more detail in the PNG specification.
+If you intend to change the filter type during the course of writing
+the image, you should start with flags set for all of the filters
+you intend to use so that libpng can initialize its internal
+structures appropriately for all of the filter types.  (Note that this
+means the first row must always be adaptively filtered, because libpng
+currently does not allocate the filter buffers until png_write_row()
+is called for the first time.)
+    filters = PNG_FILTER_NONE | PNG_FILTER_SUB
+              PNG_FILTER_UP | PNG_FILTER_AVG |
+              PNG_FILTER_PAETH | PNG_ALL_FILTERS;
+    png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE,
+       filters);
+              The second parameter can also be
+              PNG_INTRAPIXEL_DIFFERENCING if you are
+              writing a PNG to be embedded in a MNG
+              datastream.  This parameter must be the
+              same as the value of filter_method used
+              in png_set_IHDR().
+It is also possible to influence how libpng chooses from among the
+available filters.  This is done in one or both of two ways - by
+telling it how important it is to keep the same filter for successive
+rows, and by telling it the relative computational costs of the filters.
+    double weights[3] = {1.5, 1.3, 1.1},
+       costs[PNG_FILTER_VALUE_LAST] =
+       {1.0, 1.3, 1.3, 1.5, 1.7};
+    png_set_filter_heuristics(png_ptr,
+       PNG_FILTER_HEURISTIC_WEIGHTED, 3,
+       weights, costs);
+The weights are multiplying factors that indicate to libpng that the
+row filter should be the same for successive rows unless another row filter
+is that many times better than the previous filter.  In the above example,
+if the previous 3 filters were SUB, SUB, NONE, the SUB filter could have a
+"sum of absolute differences" 1.5 x 1.3 times higher than other filters
+and still be chosen, while the NONE filter could have a sum 1.1 times
+higher than other filters and still be chosen.  Unspecified weights are
+taken to be 1.0, and the specified weights should probably be declining
+like those above in order to emphasize recent filters over older filters.
+The filter costs specify for each filter type a relative decoding cost
+to be considered when selecting row filters.  This means that filters
+with higher costs are less likely to be chosen over filters with lower
+costs, unless their "sum of absolute differences" is that much smaller.
+The costs do not necessarily reflect the exact computational speeds of
+the various filters, since this would unduly influence the final image
+size.
+Note that the numbers above were invented purely for this example and
+are given only to help explain the function usage.  Little testing has
+been done to find optimum values for either the costs or the weights.
+.SS Removing unwanted object code
+There are a bunch of #define's in pngconf.h that control what parts of
+libpng are compiled.  All the defines end in _SUPPORTED.  If you are
+never going to use a capability, you can change the #define to #undef
+before recompiling libpng and save yourself code and data space, or
+you can turn off individual capabilities with defines that begin with
+PNG_NO_.
+In libpng-1.5.0 and later, the #define's are in pnglibconf.h instead.
+You can also turn all of the transforms and ancillary chunk capabilities
+off en masse with compiler directives that define
+PNG_NO_READ[or WRITE]_TRANSFORMS, or PNG_NO_READ[or WRITE]_ANCILLARY_CHUNKS,
+or all four,
+along with directives to turn on any of the capabilities that you do
+want.  The PNG_NO_READ[or WRITE]_TRANSFORMS directives disable the extra
+transformations but still leave the library fully capable of reading
+and writing PNG files with all known public chunks. Use of the
+PNG_NO_READ[or WRITE]_ANCILLARY_CHUNKS directive produces a library
+that is incapable of reading or writing ancillary chunks.  If you are
+not using the progressive reading capability, you can turn that off
+with PNG_NO_PROGRESSIVE_READ (don't confuse this with the INTERLACING
+capability, which you'll still have).
+All the reading and writing specific code are in separate files, so the
+linker should only grab the files it needs.  However, if you want to
+make sure, or if you are building a stand alone library, all the
+reading files start with "pngr" and all the writing files start with "pngw".
+The files that don't match either (like png.c, pngtrans.c, etc.)
+are used for both reading and writing, and always need to be included.
+The progressive reader is in pngpread.c
+If you are creating or distributing a dynamically linked library (a .so
+or DLL file), you should not remove or disable any parts of the library,
+as this will cause applications linked with different versions of the
+library to fail if they call functions not available in your library.
+The size of the library itself should not be an issue, because only
+those sections that are actually used will be loaded into memory.
+.SS Requesting debug printout
+The macro definition PNG_DEBUG can be used to request debugging
+printout.  Set it to an integer value in the range 0 to 3.  Higher
+numbers result in increasing amounts of debugging information.  The
+information is printed to the "stderr" file, unless another file
+name is specified in the PNG_DEBUG_FILE macro definition.
+When PNG_DEBUG > 0, the following functions (macros) become available:
+   png_debug(level, message)
+   png_debug1(level, message, p1)
+   png_debug2(level, message, p1, p2)
+in which "level" is compared to PNG_DEBUG to decide whether to print
+the message, "message" is the formatted string to be printed,
+and p1 and p2 are parameters that are to be embedded in the string
+according to printf-style formatting directives.  For example,
+   png_debug1(2, "foo=%d\n", foo);
+is expanded to
+   if (PNG_DEBUG > 2)
+      fprintf(PNG_DEBUG_FILE, "foo=%d\n", foo);
+When PNG_DEBUG is defined but is zero, the macros aren't defined, but you
+can still use PNG_DEBUG to control your own debugging:
+   #ifdef PNG_DEBUG
+       fprintf(stderr, ...
+   #endif
+When PNG_DEBUG = 1, the macros are defined, but only png_debug statements
+having level = 0 will be printed.  There aren't any such statements in
+this version of libpng, but if you insert some they will be printed.
+.SH VI.  MNG support
+The MNG specification (available at http://www.libpng.org/pub/mng) allows
+certain extensions to PNG for PNG images that are embedded in MNG datastreams.
+Libpng can support some of these extensions.  To enable them, use the
+png_permit_mng_features() function:
+   feature_set = png_permit_mng_features(png_ptr, mask)
+   mask is a png_uint_32 containing the bitwise OR of the
+        features you want to enable.  These include
+        PNG_FLAG_MNG_EMPTY_PLTE
+        PNG_FLAG_MNG_FILTER_64
+        PNG_ALL_MNG_FEATURES
+   feature_set is a png_uint_32 that is the bitwise AND of
+      your mask with the set of MNG features that is
+      supported by the version of libpng that you are using.
+It is an error to use this function when reading or writing a standalone
+PNG file with the PNG 8-byte signature.  The PNG datastream must be wrapped
+in a MNG datastream.  As a minimum, it must have the MNG 8-byte signature
+and the MHDR and MEND chunks.  Libpng does not provide support for these
+or any other MNG chunks; your application must provide its own support for
+them.  You may wish to consider using libmng (available at
+http://www.libmng.com) instead.
+.SH VII.  Changes to Libpng from version 0.88
+It should be noted that versions of libpng later than 0.96 are not
+distributed by the original libpng author, Guy Schalnat, nor by
+Andreas Dilger, who had taken over from Guy during 1996 and 1997, and
+distributed versions 0.89 through 0.96, but rather by another member
+of the original PNG Group, Glenn Randers-Pehrson.  Guy and Andreas are
+still alive and well, but they have moved on to other things.
+The old libpng functions png_read_init(), png_write_init(),
+png_info_init(), png_read_destroy(), and png_write_destroy() have been
+moved to PNG_INTERNAL in version 0.95 to discourage their use.  These
+functions will be removed from libpng version 1.4.0.
+The preferred method of creating and initializing the libpng structures is
+via the png_create_read_struct(), png_create_write_struct(), and
+png_create_info_struct() because they isolate the size of the structures
+from the application, allow version error checking, and also allow the
+use of custom error handling routines during the initialization, which
+the old functions do not.  The functions png_read_destroy() and
+png_write_destroy() do not actually free the memory that libpng
+allocated for these structs, but just reset the data structures, so they
+can be used instead of png_destroy_read_struct() and
+png_destroy_write_struct() if you feel there is too much system overhead
+allocating and freeing the png_struct for each image read.
+Setting the error callbacks via png_set_message_fn() before
+png_read_init() as was suggested in libpng-0.88 is no longer supported
+because this caused applications that do not use custom error functions
+to fail if the png_ptr was not initialized to zero.  It is still possible
+to set the error callbacks AFTER png_read_init(), or to change them with
+png_set_error_fn(), which is essentially the same function, but with a new
+name to force compilation errors with applications that try to use the old
+method.
+Starting with version 1.0.7, you can find out which version of the library
+you are using at run-time:
+   png_uint_32 libpng_vn = png_access_version_number();
+The number libpng_vn is constructed from the major version, minor
+version with leading zero, and release number with leading zero,
+(e.g., libpng_vn for version 1.0.7 is 10007).
+Note that this function does not take a png_ptr, so you can call it
+before you've created one.
+You can also check which version of png.h you used when compiling your
+application:
+   png_uint_32 application_vn = PNG_LIBPNG_VER;
+.SH VIII.  Changes to Libpng from version 1.0.x to 1.2.x
+Support for user memory management was enabled by default.  To
+accomplish this, the functions png_create_read_struct_2(),
+png_create_write_struct_2(), png_set_mem_fn(), png_get_mem_ptr(),
+png_malloc_default(), and png_free_default() were added.
+Support for the iTXt chunk has been enabled by default as of
+version 1.2.41.
+Support for certain MNG features was enabled.
+Support for numbered error messages was added.  However, we never got
+around to actually numbering the error messages.  The function
+png_set_strip_error_numbers() was added (Note: the prototype for this
+function was inadvertently removed from png.h in PNG_NO_ASSEMBLER_CODE
+builds of libpng-1.2.15.  It was restored in libpng-1.2.36).
+The png_malloc_warn() function was added at libpng-1.2.3.  This issues
+a png_warning and returns NULL instead of aborting when it fails to
+acquire the requested memory allocation.
+Support for setting user limits on image width and height was enabled
+by default.  The functions png_set_user_limits(), png_get_user_width_max(),
+and png_get_user_height_max() were added at libpng-1.2.6.
+The png_set_add_alpha() function was added at libpng-1.2.7.
+The function png_set_expand_gray_1_2_4_to_8() was added at libpng-1.2.9.
+Unlike png_set_gray_1_2_4_to_8(), the new function does not expand the
+tRNS chunk to alpha. The png_set_gray_1_2_4_to_8() function is
+deprecated.
+A number of macro definitions in support of runtime selection of
+assembler code features (especially Intel MMX code support) were
+added at libpng-1.2.0:
+    PNG_ASM_FLAG_MMX_SUPPORT_COMPILED
+    PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU
+    PNG_ASM_FLAG_MMX_READ_COMBINE_ROW
+    PNG_ASM_FLAG_MMX_READ_INTERLACE
+    PNG_ASM_FLAG_MMX_READ_FILTER_SUB
+    PNG_ASM_FLAG_MMX_READ_FILTER_UP
+    PNG_ASM_FLAG_MMX_READ_FILTER_AVG
+    PNG_ASM_FLAG_MMX_READ_FILTER_PAETH
+    PNG_ASM_FLAGS_INITIALIZED
+    PNG_MMX_READ_FLAGS
+    PNG_MMX_FLAGS
+    PNG_MMX_WRITE_FLAGS
+    PNG_MMX_FLAGS
+We added the following functions in support of runtime
+selection of assembler code features:
+    png_get_mmx_flagmask()
+    png_set_mmx_thresholds()
+    png_get_asm_flags()
+    png_get_mmx_bitdepth_threshold()
+    png_get_mmx_rowbytes_threshold()
+    png_set_asm_flags()
+We replaced all of these functions with simple stubs in libpng-1.2.20,
+when the Intel assembler code was removed due to a licensing issue.
+These macros are deprecated:
+    PNG_READ_TRANSFORMS_NOT_SUPPORTED
+    PNG_PROGRESSIVE_READ_NOT_SUPPORTED
+    PNG_NO_SEQUENTIAL_READ_SUPPORTED
+    PNG_WRITE_TRANSFORMS_NOT_SUPPORTED
+    PNG_READ_ANCILLARY_CHUNKS_NOT_SUPPORTED
+    PNG_WRITE_ANCILLARY_CHUNKS_NOT_SUPPORTED
+They have been replaced, respectively, by:
+    PNG_NO_READ_TRANSFORMS
+    PNG_NO_PROGRESSIVE_READ
+    PNG_NO_SEQUENTIAL_READ
+    PNG_NO_WRITE_TRANSFORMS
+    PNG_NO_READ_ANCILLARY_CHUNKS
+    PNG_NO_WRITE_ANCILLARY_CHUNKS
+PNG_MAX_UINT was replaced with PNG_UINT_31_MAX.  It has been
+deprecated since libpng-1.0.16 and libpng-1.2.6.
+The function
+    png_check_sig(sig, num)
+was replaced with
+    !png_sig_cmp(sig, 0, num)
+It has been deprecated since libpng-0.90.
+The function
+    png_set_gray_1_2_4_to_8()
+which also expands tRNS to alpha was replaced with
+    png_set_expand_gray_1_2_4_to_8()
+which does not. It has been deprecated since libpng-1.0.18 and 1.2.9.
+.SH IX.  Changes to Libpng from version 1.0.x/1.2.x to 1.4.x
+Private libpng prototypes and macro definitions were moved from
+png.h and pngconf.h into a new pngpriv.h header file.
+Functions png_set_benign_errors(), png_benign_error(), and
+png_chunk_benign_error() were added.
+Support for setting the maximum amount of memory that the application
+will allocate for reading chunks was added, as a security measure.
+The functions png_set_chunk_cache_max() and png_get_chunk_cache_max()
+were added to the library.
+We implemented support for I/O states by adding png_ptr member io_state
+and functions png_get_io_chunk_name() and png_get_io_state() in pngget.c
+We added PNG_TRANSFORM_GRAY_TO_RGB to the available high-level
+input transforms.
+Checking for and reporting of errors in the IHDR chunk is more thorough.
+Support for global arrays was removed, to improve thread safety.
+Some obsolete/deprecated macros and functions have been removed.
+Typecasted NULL definitions such as
+   #define png_voidp_NULL            (png_voidp)NULL
+were eliminated.  If you used these in your application, just use
+NULL instead.
+The png_struct and info_struct members "trans" and "trans_values" were
+changed to "trans_alpha" and "trans_color", respectively.
+The obsolete, unused pnggccrd.c and pngvcrd.c files and related makefiles
+were removed.
+The PNG_1_0_X and PNG_1_2_X macros were eliminated.
+The PNG_LEGACY_SUPPORTED macro was eliminated.
+Many WIN32_WCE #ifdefs were removed.
+The functions png_read_init(info_ptr), png_write_init(info_ptr),
+png_info_init(info_ptr), png_read_destroy(), and png_write_destroy()
+have been removed.  They have been deprecated since libpng-0.95.
+The png_permit_empty_plte() was removed. It has been deprecated
+since libpng-1.0.9.  Use png_permit_mng_features() instead.
+We removed the obsolete stub functions png_get_mmx_flagmask(),
+png_set_mmx_thresholds(), png_get_asm_flags(),
+png_get_mmx_bitdepth_threshold(), png_get_mmx_rowbytes_threshold(),
+png_set_asm_flags(), and png_mmx_supported()
+We removed the obsolete png_check_sig(), png_memcpy_check(), and
+png_memset_check() functions.  Instead use !png_sig_cmp(), memcpy(),
+and memset(), respectively.
+The function png_set_gray_1_2_4_to_8() was removed. It has been
+deprecated since libpng-1.0.18 and 1.2.9, when it was replaced with
+png_set_expand_gray_1_2_4_to_8() because the former function also
+expanded any tRNS chunk to an alpha channel.
+Macros for png_get_uint_16, png_get_uint_32, and png_get_int_32
+were added and are used by default instead of the corresponding
+functions. Unfortunately,
+from libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the
+function) incorrectly returned a value of type png_uint_32.
+We changed the prototype for png_malloc() from
+    png_malloc(png_structp png_ptr, png_uint_32 size)
+to
+    png_malloc(png_structp png_ptr, png_alloc_size_t size)
+This also applies to the prototype for the user replacement malloc_fn().
+The png_calloc() function was added and is used in place of
+of "png_malloc(); memset();" except in the case in png_read_png()
+where the array consists of pointers; in this case a "for" loop is used
+after the png_malloc() to set the pointers to NULL, to give robust.
+behavior in case the application runs out of memory part-way through
+the process.
+We changed the prototypes of png_get_compression_buffer_size() and
+png_set_compression_buffer_size() to work with png_size_t instead of
+png_uint_32.
+Support for numbered error messages was removed by default, since we
+never got around to actually numbering the error messages. The function
+png_set_strip_error_numbers() was removed from the library by default.
+The png_zalloc() and png_zfree() functions are no longer exported.
+The png_zalloc() function no longer zeroes out the memory that it
+allocates.
+Support for dithering was disabled by default in libpng-1.4.0, because
+it has not been well tested and doesn't actually "dither".
+The code was not
+removed, however, and could be enabled by building libpng with
+PNG_READ_DITHER_SUPPORTED defined.  In libpng-1.4.2, this support
+was reenabled, but the function was renamed png_set_quantize() to
+reflect more accurately what it actually does.  At the same time,
+the PNG_DITHER_[RED,GREEN_BLUE]_BITS macros were also renamed to
+PNG_QUANTIZE_[RED,GREEN,BLUE]_BITS, and PNG_READ_DITHER_SUPPORTED
+was renamed to PNG_READ_QUANTIZE_SUPPORTED.
+We removed the trailing '.' from the warning and error messages.
+.SH X.  Changes to Libpng from version 1.4.x to 1.5.x
+From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the
+function) incorrectly returned a value of type png_uint_32.
+A. Changes that affect users of libpng
+There are no substantial API changes between the non-deprecated parts of
+the 1.4.5 API and the 1.5.0 API, however the ability to directly access
+the main libpng control structures, png_struct and png_info, deprecated
+in earlier versions of libpng, has been completely removed from
+libpng 1.5.
+We no longer include zlib.h in png.h.  Applications that need access
+to information in zlib.h will need to add the '#include "zlib.h"'
+directive.  It does not matter whether it is placed prior to or after
+the '"#include png.h"' directive.
+We moved the png_strcpy(), png_strncpy(), png_strlen(), png_memcpy(),
+png_memcmp(), png_sprintf, and png_memcpy() macros into a private
+header file (pngpriv.h) that is not accessible to applications.
+In png_get_iCCP, the type of "profile" was changed from png_charpp
+to png_bytepp, and in png_set_iCCP, from png_charp to png_const_bytep.
+There are changes of form in png.h, including new and changed macros to
+declare parts of the API.  Some API functions with arguments that are
+pointers to data not modified within the function have been corrected to
+declare these arguments with PNG_CONST.
+Much of the internal use of C macros to control the library build has also
+changed and some of this is visible in the exported header files, in
+particular the use of macros to control data and API elements visible
+during application compilation may require significant revision to
+application code.  (It is extremely rare for an application to do this.)
+Any program that compiled against libpng 1.4 and did not use deprecated
+features or access internal library structures should compile and work
+against libpng 1.5, except for the change in the prototype for
+png_get_iCCP() and png_set_iCCP() API functions mentioned above.
+libpng 1.5.0 adds PNG_ PASS macros to help in the reading and writing of
+interlaced images.  The macros return the number of rows and columns in
+each pass and information that can be used to de-interlace and (if
+absolutely necessary) interlace an image.
+libpng 1.5.0 adds an API png_longjmp(png_ptr, value).  This API calls
+the application-provided png_longjmp_ptr on the internal, but application
+initialized, longjmp buffer.  It is provided as a convenience to avoid
+the need to use the png_jmpbuf macro, which had the unnecessary side
+effect of resetting the internal png_longjmp_ptr value.
+libpng 1.5.0 includes a complete fixed point API.  By default this is
+present along with the corresponding floating point API.  In general the
+fixed point API is faster and smaller than the floating point one because
+the PNG file format used fixed point, not floating point.  This applies
+even if the library uses floating point in internal calculations.  A new
+macro, PNG_FLOATING_ARITHMETIC_SUPPORTED, reveals whether the library
+uses floating point arithmetic (the default) or fixed point arithmetic
+internally for performance critical calculations such as gamma correction.
+In some cases, the gamma calculations may produce slightly different
+results.  This has changed the results in png_rgb_to_gray and in alpha
+composition (png_set_background for example). This applies even if the
+original image was already linear (gamma == 1.0) and, therefore, it is
+not necessary to linearize the image.  This is because libpng has *not*
+been changed to optimize that case correctly, yet.
+Fixed point support for the sCAL chunk comes with an important caveat;
+the sCAL specification uses a decimal encoding of floating point values
+and the accuracy of PNG fixed point values is insufficient for
+representation of these values. Consequently a "string" API
+(png_get_sCAL_s and png_set_sCAL_s) is the only reliable way of reading
+arbitrary sCAL chunks in the absence of either the floating point API or
+internal floating point calculations.
+Applications no longer need to include the optional distribution header
+file pngusr.h or define the corresponding macros during application
+build in order to see the correct variant of the libpng API.  From 1.5.0
+application code can check for the corresponding _SUPPORTED macro:
+#ifdef PNG_INCH_CONVERSIONS_SUPPORTED
+   /* code that uses the inch conversion APIs. */
+#endif
+This macro will only be defined if the inch conversion functions have been
+compiled into libpng.  The full set of macros, and whether or not support
+has been compiled in, are available in the header file pnglibconf.h.
+This header file is specific to the libpng build.  Notice that prior to
+1.5.0 the _SUPPORTED macros would always have the default definition unless
+reset by pngusr.h or by explicit settings on the compiler command line.
+These settings may produce compiler warnings or errors in 1.5.0 because
+of macro redefinition.
+From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the
+function) incorrectly returned a value of type png_uint_32.  libpng 1.5.0
+is consistent with the implementation in 1.4.5 and 1.2.x (where the macro
+did not exist.)
+Applications can now choose whether to use these macros or to call the
+corresponding function by defining PNG_USE_READ_MACROS or
+PNG_NO_USE_READ_MACROS before including png.h.  Notice that this is
+only supported from 1.5.0 -defining PNG_NO_USE_READ_MACROS prior to 1.5.0
+will lead to a link failure.
+Prior to libpng-1.5.4, the zlib compressor used the same set of parameters
+when compressing the IDAT data and textual data such as zTXt and iCCP.
+In libpng-1.5.4 we reinitialized the zlib stream for each type of data.
+We added five png_set_text_*() functions for setting the parameters to
+use with textual data.
+Prior to libpng-1.5.4, the PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED
+option was off by default, and slightly inaccurate scaling occurred.
+This option can no longer be turned off, and the choice of accurate
+or inaccurate 16-to-8 scaling is by using the new png_set_scale_16_to_8()
+API for accurate scaling or the old png_set_strip_16_to_8() API for simple
+chopping.
+Prior to libpng-1.5.4, the png_set_user_limits() function could only be
+used to reduce the width and height limits from the value of
+PNG_USER_WIDTH_MAX and PNG_USER_HEIGHT_MAX, although this document said
+that it could be used to override them.  Now this function will reduce or
+increase the limits.
+B. Changes to the build and configuration of libpng
+Details of internal changes to the library code can be found in the CHANGES
+file and in the GIT repository logs.  These will be of no concern to the vast
+majority of library users or builders, however the few who configure libpng
+to a non-default feature set may need to change how this is done.
+There should be no need for library builders to alter build scripts if
+these use the distributed build support - configure or the makefiles -
+however users of the makefiles may care to update their build scripts
+to build pnglibconf.h where the corresponding makefile does not do so.
+Building libpng with a non-default configuration has changed completely.
+The old method using pngusr.h should still work correctly even though the
+way pngusr.h is used in the build has been changed; however, library
+builders will probably want to examine the changes to take advantage of
+new capabilities and to simplify their build system.
+B.1 Specific changes to library configuration capabilities
+The library now supports a complete fixed point implementation and can
+thus be used on systems that have no floating point support or very
+limited or slow support.  Previously gamma correction, an essential part
+of complete PNG support, required reasonably fast floating point.
+As part of this the choice of internal implementation has been made
+independent of the choice of fixed versus floating point APIs and all the
+missing fixed point APIs have been implemented.
+The exact mechanism used to control attributes of API functions has
+changed.  A single set of operating system independent macro definitions
+is used and operating system specific directives are defined in
+pnglibconf.h
+As part of this the mechanism used to choose procedure call standards on
+those systems that allow a choice has been changed.  At present this only
+affects certain Microsoft (DOS, Windows) and IBM (OS/2) operating systems
+running on Intel processors.  As before, PNGAPI is defined where required
+to control the exported API functions; however, two new macros, PNGCBAPI
+and PNGCAPI, are used instead for callback functions (PNGCBAPI) and
+(PNGCAPI) for functions that must match a C library prototype (currently
+only png_longjmp_ptr, which must match the C longjmp function.)  The new
+approach is documented in pngconf.h
+Despite these changes, libpng 1.5.0 only supports the native C function
+calling standard on those platforms tested so far (__cdecl on Microsoft
+Windows).  This is because the support requirements for alternative
+calling conventions seem to no longer exist.  Developers who find it
+necessary to set PNG_API_RULE to 1 should advise the mailing list
+(png-mng-implement) of this and library builders who use Openwatcom and
+therefore set PNG_API_RULE to 2 should also contact the mailing list.
+A new test program, pngvalid, is provided in addition to pngtest.
+pngvalid validates the arithmetic accuracy of the gamma correction
+calculations and includes a number of validations of the file format.
+A subset of the full range of tests is run when "make check" is done
+(in the 'configure' build.)  pngvalid also allows total allocated memory
+usage to be evaluated and performs additional memory overwrite validation.
+Many changes to individual feature macros have been made. The following
+are the changes most likely to be noticed by library builders who
+configure libpng:
+1) All feature macros now have consistent naming:
+#define PNG_NO_feature turns the feature off
+#define PNG_feature_SUPPORTED turns the feature on
+pnglibconf.h contains one line for each feature macro which is either:
+#define PNG_feature_SUPPORTED
+if the feature is supported or:
+/*#undef PNG_feature_SUPPORTED*/
+if it is not.  Library code consistently checks for the 'SUPPORTED' macro.
+It does not, and libpng applications should not, check for the 'NO' macro
+which will not normally be defined even if the feature is not supported.
+The 'NO' macros are only used internally for setting or not setting the
+corresponding 'SUPPORTED' macros.
+Compatibility with the old names is provided as follows:
+PNG_INCH_CONVERSIONS turns on PNG_INCH_CONVERSIONS_SUPPORTED
+And the following definitions disable the corresponding feature:
+PNG_SETJMP_NOT_SUPPORTED disables SETJMP
+PNG_READ_TRANSFORMS_NOT_SUPPORTED disables READ_TRANSFORMS
+PNG_NO_READ_COMPOSITED_NODIV disables READ_COMPOSITE_NODIV
+PNG_WRITE_TRANSFORMS_NOT_SUPPORTED disables WRITE_TRANSFORMS
+PNG_READ_ANCILLARY_CHUNKS_NOT_SUPPORTED disables READ_ANCILLARY_CHUNKS
+PNG_WRITE_ANCILLARY_CHUNKS_NOT_SUPPORTED disables WRITE_ANCILLARY_CHUNKS
+Library builders should remove use of the above, inconsistent, names.
+2) Warning and error message formatting was previously conditional on
+the STDIO feature. The library has been changed to use the
+CONSOLE_IO feature instead. This means that if CONSOLE_IO is disabled
+the library no longer uses the printf(3) functions, even though the
+default read/write implementations use (FILE) style stdio.h functions.
+3) Three feature macros now control the fixed/floating point decisions:
+PNG_FLOATING_POINT_SUPPORTED enables the floating point APIs
+PNG_FIXED_POINT_SUPPORTED enables the fixed point APIs; however, in
+practice these are normally required internally anyway (because the PNG
+file format is fixed point), therefore in most cases PNG_NO_FIXED_POINT
+merely stops the function from being exported.
+PNG_FLOATING_ARITHMETIC_SUPPORTED chooses between the internal floating
+point implementation or the fixed point one.  Typically the fixed point
+implementation is larger and slower than the floating point implementation
+on a system that supports floating point, however it may be faster on a
+system which lacks floating point hardware and therefore uses a software
+emulation.
+4) Added PNG_{READ,WRITE}_INT_FUNCTIONS_SUPPORTED.  This allows the
+functions to read and write ints to be disabled independently of
+PNG_USE_READ_MACROS, which allows libpng to be built with the functions
+even though the default is to use the macros - this allows applications
+to choose at app buildtime whether or not to use macros (previously
+impossible because the functions weren't in the default build.)
+B.2 Changes to the configuration mechanism
+Prior to libpng-1.5.0 library builders who needed to configure libpng
+had either to modify the exported pngconf.h header file to add system
+specific configuration or had to write feature selection macros into
+pngusr.h and cause this to be included into pngconf.h by defining
+PNG_USER_CONFIG. The latter mechanism had the disadvantage that an
+application built without PNG_USER_CONFIG defined would see the
+unmodified, default, libpng API and thus would probably fail to link.
+These mechanisms still work in the configure build and in any makefile
+build that builds pnglibconf.h, although the feature selection macros
+have changed somewhat as described above.  In 1.5.0, however, pngusr.h is
+processed only once, when the exported header file pnglibconf.h is built.
+pngconf.h no longer includes pngusr.h, therefore pngusr.h is ignored after the
+build of pnglibconf.h and it is never included in an application build.
+The rarely used alternative of adding a list of feature macros to the
+CFLAGS setting in the build also still works, however the macros will be
+copied to pnglibconf.h and this may produce macro redefinition warnings
+when the individual C files are compiled.
+All configuration now only works if pnglibconf.h is built from
+scripts/pnglibconf.dfa.  This requires the program awk.  Brian Kernighan
+(the original author of awk) maintains C source code of that awk and this
+and all known later implementations (often called by subtly different
+names - nawk and gawk for example) are adequate to build pnglibconf.h.
+The Sun Microsystems (now Oracle) program 'awk' is an earlier version
+and does not work; this may also apply to other systems that have a
+functioning awk called 'nawk'.
+Configuration options are now documented in scripts/pnglibconf.dfa.  This
+file also includes dependency information that ensures a configuration is
+consistent; that is, if a feature is switched off dependent features are
+also removed.  As a recommended alternative to using feature macros in
+pngusr.h a system builder may also define equivalent options in pngusr.dfa
+(or, indeed, any file) and add that to the configuration by setting
+DFA_XTRA to the file name.  The makefiles in contrib/pngminim illustrate
+how to do this, and a case where pngusr.h is still required.
+.SH XI. Detecting libpng
+The png_get_io_ptr() function has been present since libpng-0.88, has never
+changed, and is unaffected by conditional compilation macros.  It is the
+best choice for use in configure scripts for detecting the presence of any
+libpng version since 0.88.  In an autoconf "configure.in" you could use
+    AC_CHECK_LIB(png, png_get_io_ptr, ...
+.SH XII. Source code repository
+Since about February 2009, version 1.2.34, libpng has been under "git" source
+control.  The git repository was built from old libpng-x.y.z.tar.gz files
+going back to version 0.70.  You can access the git repository (read only)
+at
+    git://libpng.git.sourceforge.net/gitroot/libpng
+or you can browse it via "gitweb" at
+    http://libpng.git.sourceforge.net/git/gitweb.cgi?p=libpng
+Patches can be sent to glennrp at users.sourceforge.net or to
+png-mng-implement at lists.sourceforge.net or you can upload them to
+the libpng bug tracker at
+    http://libpng.sourceforge.net
+We also accept patches built from the tar or zip distributions, and
+simple verbal discriptions of bug fixes, reported either to the
+SourceForge bug tracker, to the png-mng-implement at lists.sf.net
+mailing list, or directly to glennrp.
+.SH XIII. Coding style
+Our coding style is similar to the "Allman" style, with curly
+braces on separate lines:
+    if (condition)
+    {
+       action;
+    }
+    else if (another condition)
+    {
+       another action;
+    }
+The braces can be omitted from simple one-line actions:
+    if (condition)
+       return (0);
+We use 3-space indentation, except for continued statements which
+are usually indented the same as the first line of the statement
+plus four more spaces.
+For macro definitions we use 2-space indentation, always leaving the "#"
+in the first column.
+    #ifndef PNG_NO_FEATURE
+    #  ifndef PNG_FEATURE_SUPPORTED
+    #    define PNG_FEATURE_SUPPORTED
+    #  endif
+    #endif
+Comments appear with the leading "/*" at the same indentation as
+the statement that follows the comment:
+    /* Single-line comment */
+    statement;
+    /* This is a multiple-line
+     * comment.
+     */
+    statement;
+Very short comments can be placed after the end of the statement
+to which they pertain:
+    statement;    /* comment */
+We don't use C++ style ("//") comments. We have, however,
+used them in the past in some now-abandoned MMX assembler
+code.
+Functions and their curly braces are not indented, and
+exported functions are marked with PNGAPI:
+ /* This is a public function that is visible to
+  * application programmers. It does thus-and-so.
+  */
+ void PNGAPI
+ png_exported_function(png_ptr, png_info, foo)
+ {
+    body;
+ }
+The prototypes for all exported functions appear in png.h,
+above the comment that says
+    /* Maintainer: Put new public prototypes here ... */
+We mark all non-exported functions with "/* PRIVATE */"":
+ void /* PRIVATE */
+ png_non_exported_function(png_ptr, png_info, foo)
+ {
+    body;
+ }
+The prototypes for non-exported functions (except for those in
+pngtest) appear in
+pngpriv.h
+above the comment that says
+  /* Maintainer: Put new private prototypes here ^ and in libpngpf.3 */
+To avoid polluting the global namespace, the names of all exported
+functions and variables begin with  "png_", and all publicly visible C
+preprocessor macros begin with "PNG_".  We request that applications that
+use libpng *not* begin any of their own symbols with either of these strings.
+We put a space after each comma and after each semicolon
+in "for" statements, and we put spaces before and after each
+C binary operator and after "for" or "while", and before
+"?".  We don't put a space between a typecast and the expression
+being cast, nor do we put one between a function name and the
+left parenthesis that follows it:
+    for (i = 2; i > 0; --i)
+       y[i] = a(x) + (int)b;
+We prefer #ifdef and #ifndef to #if defined() and if !defined()
+when there is only one macro being tested.
+We prefer to express integers that are used as bit masks in hex format,
+with an even number of lower-case hex digits (e.g., 0x00, 0xff, 0x0100).
+We do not use the TAB character for indentation in the C sources.
+Lines do not exceed 80 characters.
+Other rules can be inferred by inspecting the libpng source.
+.SH XIV. Y2K Compliance in libpng
+February 18, 2012
+Since the PNG Development group is an ad-hoc body, we can't make
+an official declaration.
+This is your unofficial assurance that libpng from version 0.71 and
+upward through 1.5.9 are Y2K compliant.  It is my belief that earlier
+versions were also Y2K compliant.
+Libpng only has three year fields.  One is a 2-byte unsigned integer that
+will hold years up to 65535.  The other two hold the date in text
+format, and will hold years up to 9999.
+The integer is
+    "png_uint_16 year" in png_time_struct.
+The strings are
+    "png_charp time_buffer" in png_struct and
+    "near_time_buffer", which is a local character string in png.c.
+There are seven time-related functions:
+    png_convert_to_rfc_1123() in png.c
+      (formerly png_convert_to_rfc_1152() in error)
+    png_convert_from_struct_tm() in pngwrite.c, called
+      in pngwrite.c
+    png_convert_from_time_t() in pngwrite.c
+    png_get_tIME() in pngget.c
+    png_handle_tIME() in pngrutil.c, called in pngread.c
+    png_set_tIME() in pngset.c
+    png_write_tIME() in pngwutil.c, called in pngwrite.c
+All appear to handle dates properly in a Y2K environment.  The
+png_convert_from_time_t() function calls gmtime() to convert from system
+clock time, which returns (year - 1900), which we properly convert to
+the full 4-digit year.  There is a possibility that applications using
+libpng are not passing 4-digit years into the png_convert_to_rfc_1123()
+function, or that they are incorrectly passing only a 2-digit year
+instead of "year - 1900" into the png_convert_from_struct_tm() function,
+but this is not under our control.  The libpng documentation has always
+stated that it works with 4-digit years, and the APIs have been
+documented as such.
+The tIME chunk itself is also Y2K compliant.  It uses a 2-byte unsigned
+integer to hold the year, and can hold years as large as 65535.
+zlib, upon which libpng depends, is also Y2K compliant.  It contains
+no date-related code.
+   Glenn Randers-Pehrson
+   libpng maintainer
+   PNG Development Group
+.SH NOTE
+Note about libpng version numbers:
+Due to various miscommunications, unforeseen code incompatibilities
+and occasional factors outside the authors' control, version numbering
+on the library has not always been consistent and straightforward.
+The following table summarizes matters since version 0.89c, which was
+the first widely used release:
+ source             png.h  png.h  shared-lib
+ version            string   int  version
+ -------            ------  ----- ----------
+ 0.89c ("beta 3")  0.89       89  1.0.89
+ 0.90  ("beta 4")  0.90       90  0.90
+ 0.95  ("beta 5")  0.95       95  0.95
+ 0.96  ("beta 6")  0.96       96  0.96
+ 0.97b ("beta 7")  1.00.97    97  1.0.1
+ 0.97c             0.97       97  2.0.97
+ 0.98              0.98       98  2.0.98
+ 0.99              0.99       98  2.0.99
+ 0.99a-m           0.99       99  2.0.99
+ 1.00              1.00      100  2.1.0
+ 1.0.0             1.0.0     100  2.1.0
+ 1.0.0   (from here on, the  100  2.1.0
+ 1.0.1    png.h string is  10001  2.1.0
+ 1.0.1a-e identical to the 10002  from here on, the
+ 1.0.2    source version)  10002  shared library is 2.V
+ 1.0.2a-b                  10003  where V is the source
+ 1.0.1                     10001  code version except as
+ 1.0.1a-e                  10002  2.1.0.1a-e   noted.
+ 1.0.2                     10002  2.1.0.2
+ 1.0.2a-b                  10003  2.1.0.2a-b
+ 1.0.3                     10003  2.1.0.3
+ 1.0.3a-d                  10004  2.1.0.3a-d
+ 1.0.4                     10004  2.1.0.4
+ 1.0.4a-f                  10005  2.1.0.4a-f
+ 1.0.5 (+ 2 patches)       10005  2.1.0.5
+ 1.0.5a-d                  10006  2.1.0.5a-d
+ 1.0.5e-r                  10100  2.1.0.5e-r
+ 1.0.5s-v                  10006  2.1.0.5s-v
+ 1.0.6 (+ 3 patches)       10006  2.1.0.6
+ 1.0.6d-g                  10007  2.1.0.6d-g
+ 1.0.6h                    10007  10.6h
+ 1.0.6i                    10007  10.6i
+ 1.0.6j                    10007  2.1.0.6j
+ 1.0.7beta11-14    DLLNUM  10007  2.1.0.7beta11-14
+ 1.0.7beta15-18       1    10007  2.1.0.7beta15-18
+ 1.0.7rc1-2           1    10007  2.1.0.7rc1-2
+ 1.0.7                1    10007  2.1.0.7
+ 1.0.8beta1-4         1    10008  2.1.0.8beta1-4
+ 1.0.8rc1             1    10008  2.1.0.8rc1
+ 1.0.8                1    10008  2.1.0.8
+ 1.0.9beta1-6         1    10009  2.1.0.9beta1-6
+ 1.0.9rc1             1    10009  2.1.0.9rc1
+ 1.0.9beta7-10        1    10009  2.1.0.9beta7-10
+ 1.0.9rc2             1    10009  2.1.0.9rc2
+ 1.0.9                1    10009  2.1.0.9
+ 1.0.10beta1          1    10010  2.1.0.10beta1
+ 1.0.10rc1            1    10010  2.1.0.10rc1
+ 1.0.10               1    10010  2.1.0.10
+ 1.0.11beta1-3        1    10011  2.1.0.11beta1-3
+ 1.0.11rc1            1    10011  2.1.0.11rc1
+ 1.0.11               1    10011  2.1.0.11
+ 1.0.12beta1-2        2    10012  2.1.0.12beta1-2
+ 1.0.12rc1            2    10012  2.1.0.12rc1
+ 1.0.12               2    10012  2.1.0.12
+ 1.1.0a-f             -    10100  2.1.1.0a-f abandoned
+ 1.2.0beta1-2         2    10200  2.1.2.0beta1-2
+ 1.2.0beta3-5         3    10200  3.1.2.0beta3-5
+ 1.2.0rc1             3    10200  3.1.2.0rc1
+ 1.2.0                3    10200  3.1.2.0
+ 1.2.1beta-4          3    10201  3.1.2.1beta1-4
+ 1.2.1rc1-2           3    10201  3.1.2.1rc1-2
+ 1.2.1                3    10201  3.1.2.1
+ 1.2.2beta1-6        12    10202  12.so.0.1.2.2beta1-6
+ 1.0.13beta1         10    10013  10.so.0.1.0.13beta1
+ 1.0.13rc1           10    10013  10.so.0.1.0.13rc1
+ 1.2.2rc1            12    10202  12.so.0.1.2.2rc1
+ 1.0.13              10    10013  10.so.0.1.0.13
+ 1.2.2               12    10202  12.so.0.1.2.2
+ 1.2.3rc1-6          12    10203  12.so.0.1.2.3rc1-6
+ 1.2.3               12    10203  12.so.0.1.2.3
+ 1.2.4beta1-3        13    10204  12.so.0.1.2.4beta1-3
+ 1.2.4rc1            13    10204  12.so.0.1.2.4rc1
+ 1.0.14              10    10014  10.so.0.1.0.14
+ 1.2.4               13    10204  12.so.0.1.2.4
+ 1.2.5beta1-2        13    10205  12.so.0.1.2.5beta1-2
+ 1.0.15rc1           10    10015  10.so.0.1.0.15rc1
+ 1.0.15              10    10015  10.so.0.1.0.15
+ 1.2.5               13    10205  12.so.0.1.2.5
+ 1.2.6beta1-4        13    10206  12.so.0.1.2.6beta1-4
+ 1.2.6rc1-5          13    10206  12.so.0.1.2.6rc1-5
+ 1.0.16              10    10016  10.so.0.1.0.16
+ 1.2.6               13    10206  12.so.0.1.2.6
+ 1.2.7beta1-2        13    10207  12.so.0.1.2.7beta1-2
+ 1.0.17rc1           10    10017  12.so.0.1.0.17rc1
+ 1.2.7rc1            13    10207  12.so.0.1.2.7rc1
+ 1.0.17              10    10017  12.so.0.1.0.17
+ 1.2.7               13    10207  12.so.0.1.2.7
+ 1.2.8beta1-5        13    10208  12.so.0.1.2.8beta1-5
+ 1.0.18rc1-5         10    10018  12.so.0.1.0.18rc1-5
+ 1.2.8rc1-5          13    10208  12.so.0.1.2.8rc1-5
+ 1.0.18              10    10018  12.so.0.1.0.18
+ 1.2.8               13    10208  12.so.0.1.2.8
+ 1.2.9beta1-3        13    10209  12.so.0.1.2.9beta1-3
+ 1.2.9beta4-11       13    10209  12.so.0.9[.0]
+ 1.2.9rc1            13    10209  12.so.0.9[.0]
+ 1.2.9               13    10209  12.so.0.9[.0]
+ 1.2.10beta1-7       13    10210  12.so.0.10[.0]
+ 1.2.10rc1-2         13    10210  12.so.0.10[.0]
+ 1.2.10              13    10210  12.so.0.10[.0]
+ 1.4.0beta1-6        14    10400  14.so.0.0[.0]
+ 1.2.11beta1-4       13    10210  12.so.0.11[.0]
+ 1.4.0beta7-8        14    10400  14.so.0.0[.0]
+ 1.2.11              13    10211  12.so.0.11[.0]
+ 1.2.12              13    10212  12.so.0.12[.0]
+ 1.4.0beta9-14       14    10400  14.so.0.0[.0]
+ 1.2.13              13    10213  12.so.0.13[.0]
+ 1.4.0beta15-36      14    10400  14.so.0.0[.0]
+ 1.4.0beta37-87      14    10400  14.so.14.0[.0]
+ 1.4.0rc01           14    10400  14.so.14.0[.0]
+ 1.4.0beta88-109     14    10400  14.so.14.0[.0]
+ 1.4.0rc02-08        14    10400  14.so.14.0[.0]
+ 1.4.0               14    10400  14.so.14.0[.0]
+ 1.4.1beta01-03      14    10401  14.so.14.1[.0]
+ 1.4.1rc01           14    10401  14.so.14.1[.0]
+ 1.4.1beta04-12      14    10401  14.so.14.1[.0]
+ 1.4.1               14    10401  14.so.14.1[.0]
+ 1.4.2               14    10402  14.so.14.2[.0]
+ 1.4.3               14    10403  14.so.14.3[.0]
+ 1.4.4               14    10404  14.so.14.4[.0]
+ 1.5.0beta01-58      15    10500  15.so.15.0[.0]
+ 1.5.0rc01-07        15    10500  15.so.15.0[.0]
+ 1.5.0               15    10500  15.so.15.0[.0]
+ 1.5.1beta01-11      15    10501  15.so.15.1[.0]
+ 1.5.1rc01-02        15    10501  15.so.15.1[.0]
+ 1.5.1               15    10501  15.so.15.1[.0]
+ 1.5.2beta01-03      15    10502  15.so.15.2[.0]
+ 1.5.2rc01-03        15    10502  15.so.15.2[.0]
+ 1.5.2               15    10502  15.so.15.2[.0]
+ 1.5.3beta01-10      15    10503  15.so.15.3[.0]
+ 1.5.3rc01-02        15    10503  15.so.15.3[.0]
+ 1.5.3beta11         15    10503  15.so.15.3[.0]
+ 1.5.3 [omitted]
+ 1.5.4beta01-08      15    10504  15.so.15.4[.0]
+ 1.5.4rc01           15    10504  15.so.15.4[.0]
+ 1.5.4               15    10504  15.so.15.4[.0]
+ 1.5.5beta01-08      15    10505  15.so.15.5[.0]
+ 1.5.5rc01           15    10505  15.so.15.5[.0]
+ 1.5.5               15    10505  15.so.15.5[.0]
+ 1.5.6beta01-07      15    10506  15.so.15.6[.0]
+ 1.5.6rc01-03        15    10506  15.so.15.6[.0]
+ 1.5.6               15    10506  15.so.15.6[.0]
+ 1.5.7beta01-05      15    10507  15.so.15.7[.0]
+ 1.5.7rc01-03        15    10507  15.so.15.7[.0]
+ 1.5.7               15    10507  15.so.15.7[.0]
+ 1.5.8beta01         15    10508  15.so.15.8[.0]
+ 1.5.8rc01           15    10508  15.so.15.8[.0]
+ 1.5.8               15    10508  15.so.15.8[.0]
+ 1.5.9beta01-02      15    10509  15.so.15.9[.0]
+ 1.5.9rc01           15    10509  15.so.15.9[.0]
+ 1.5.9               15    10509  15.so.15.9[.0]
+Henceforth the source version will match the shared-library minor
+and patch numbers; the shared-library major version number will be
+used for changes in backward compatibility, as it is intended.  The
+PNG_PNGLIB_VER macro, which is not used within libpng but is available
+for applications, is an unsigned integer of the form xyyzz corresponding
+to the source version x.y.z (leading zeros in y and z).  Beta versions
+were given the previous public release number plus a letter, until
+version 1.0.6j; from then on they were given the upcoming public
+release number plus "betaNN" or "rcN".
+.SH "SEE ALSO"
+.BR "png"(5), " libpngpf"(3), " zlib"(3), " deflate"(5), " " and " zlib"(5)
+.LP
+.IR libpng :
+.IP
+http://libpng.sourceforge.net (follow the [DOWNLOAD] link)
+http://www.libpng.org/pub/png
+.LP
+.IR zlib :
+.IP
+(generally) at the same location as
+.I libpng
+or at
+.br
+ftp://ftp.info-zip.org/pub/infozip/zlib
+.LP
+.IR PNG specification: RFC 2083
+.IP
+(generally) at the same location as
+.I libpng
+or at
+.br
+ftp://ds.internic.net/rfc/rfc2083.txt
+.br
+or (as a W3C Recommendation) at
+.br
+http://www.w3.org/TR/REC-png.html
+.LP
+In the case of any inconsistency between the PNG specification
+and this library, the specification takes precedence.
+.SH AUTHORS
+This man page: Glenn Randers-Pehrson
+<glennrp at users.sourceforge.net>
+The contributing authors would like to thank all those who helped
+with testing, bug fixes, and patience.  This wouldn't have been
+possible without all of you.
+Thanks to Frank J. T. Wojcik for helping with the documentation.
+Libpng version 1.5.9 - February 18, 2012:
+Initially created in 1995 by Guy Eric Schalnat, then of Group 42, Inc.
+Currently maintained by Glenn Randers-Pehrson (glennrp at users.sourceforge.net).
+Supported by the PNG development group
+.br
+png-mng-implement at lists.sf.net
+(subscription required; visit
+png-mng-implement at lists.sourceforge.net (subscription required; visit
+https://lists.sourceforge.net/lists/listinfo/png-mng-implement
+to subscribe).
+.SH COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
+(This copy of the libpng notices is provided for your convenience.  In case of
+any discrepancy between this copy and the notices in the file png.h that is
+included in the libpng distribution, the latter shall prevail.)
+If you modify libpng you may insert additional notices immediately following
+this sentence.
+This code is released under the libpng license.
+libpng versions 1.2.6, August 15, 2004, through 1.5.9, February 18, 2012, are
+Copyright (c) 2004,2006-2007 Glenn Randers-Pehrson, and are
+distributed according to the same disclaimer and license as libpng-1.2.5
+with the following individual added to the list of Contributing Authors
+   Cosmin Truta
+libpng versions 1.0.7, July 1, 2000, through 1.2.5 - October 3, 2002, are
+Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are
+distributed according to the same disclaimer and license as libpng-1.0.6
+with the following individuals added to the list of Contributing Authors
+   Simon-Pierre Cadieux
+   Eric S. Raymond
+   Gilles Vollant
+and with the following additions to the disclaimer:
+   There is no warranty against interference with your
+   enjoyment of the library or against infringement.
+   There is no warranty that our efforts or the library
+   will fulfill any of your particular purposes or needs.
+   This library is provided with all faults, and the entire
+   risk of satisfactory quality, performance, accuracy, and
+   effort is with the user.
+libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
+Copyright (c) 1998, 1999 Glenn Randers-Pehrson
+Distributed according to the same disclaimer and license as libpng-0.96,
+with the following individuals added to the list of Contributing Authors:
+   Tom Lane
+   Glenn Randers-Pehrson
+   Willem van Schaik
+libpng versions 0.89, June 1996, through 0.96, May 1997, are
+Copyright (c) 1996, 1997 Andreas Dilger
+Distributed according to the same disclaimer and license as libpng-0.88,
+with the following individuals added to the list of Contributing Authors:
+   John Bowler
+   Kevin Bracey
+   Sam Bushell
+   Magnus Holmgren
+   Greg Roelofs
+   Tom Tanner
+libpng versions 0.5, May 1995, through 0.88, January 1996, are
+Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
+For the purposes of this copyright and license, "Contributing Authors"
+is defined as the following set of individuals:
+   Andreas Dilger
+   Dave Martindale
+   Guy Eric Schalnat
+   Paul Schmidt
+   Tim Wegner
+The PNG Reference Library is supplied "AS IS".  The Contributing Authors
+and Group 42, Inc. disclaim all warranties, expressed or implied,
+including, without limitation, the warranties of merchantability and of
+fitness for any purpose.  The Contributing Authors and Group 42, Inc.
+assume no liability for direct, indirect, incidental, special, exemplary,
+or consequential damages, which may result from the use of the PNG
+Reference Library, even if advised of the possibility of such damage.
+Permission is hereby granted to use, copy, modify, and distribute this
+source code, or portions hereof, for any purpose, without fee, subject
+to the following restrictions:
+1. The origin of this source code must not be misrepresented.
+2. Altered versions must be plainly marked as such and
+   must not be misrepresented as being the original source.
+3. This Copyright notice may not be removed or altered from
+   any source or altered source distribution.
+The Contributing Authors and Group 42, Inc. specifically permit, without
+fee, and encourage the use of this source code as a component to
+supporting the PNG file format in commercial products.  If you use this
+source code in a product, acknowledgment is not required but would be
+appreciated.
+A "png_get_copyright" function is available, for convenient use in "about"
+boxes and the like:
+   printf("%s",png_get_copyright(NULL));
+Also, the PNG logo (in PNG format, of course) is supplied in the
+files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
+Libpng is OSI Certified Open Source Software.  OSI Certified Open Source is a
+certification mark of the Open Source Initiative.
+Glenn Randers-Pehrson
+glennrp at users.sourceforge.net
+February 18, 2012
+.\" end of man page
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/libpng.pc.in b/libraries/irrlicht-1.8/source/Irrlicht/libpng/libpng.pc.in
new file mode 100644
index 0000000..05ad81e
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/libpng.pc.in
@@ -0,0 +1,11 @@
+prefix=@prefix@
+exec_prefix=@exec_prefix@
+libdir=@libdir@
+includedir=@includedir@/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@
+Name: libpng
+Description: Loads and saves PNG files
+Version: @PNGLIB_VERSION@
+Libs: -L${libdir} -lpng@PNGLIB_MAJOR@@PNGLIB_MINOR@
+Libs.private: @LIBS@
+Cflags: -I${includedir}
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/libpngpf.3 b/libraries/irrlicht-1.8/source/Irrlicht/libpng/libpngpf.3
new file mode 100644
index 0000000..ef54f7b
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/libpngpf.3
@@ -0,0 +1,28 @@
+.TH LIBPNGPF 3 "February 18, 2012"
+.SH NAME
+libpng \- Portable Network Graphics (PNG) Reference Library 1.5.9
+(private functions)
+.SH SYNOPSIS
+\fB#include \fI"pngpriv.h"
+\fI\fB
+\fBAs of libpng version \fP\fI1.5.1\fP\fB, this section is no longer \fP\fImaintained\fP\fB, now \fIthat
+\fBthe private function prototypes are hidden in pngpriv.h and not \fIaccessible
+\fBto applications. Look in pngpriv.h for the prototypes and a short \fIdescription
+\fBof each \fIfunction.
+\fI\fB
+.SH DESCRIPTION
+The functions previously listed here are used privately by libpng
+and are not recommended for use by applications.  They are
+not "exported" to applications using shared libraries.
+.SH SEE ALSO
+.BR "png"(5), " libpng"(3), " zlib"(3), " deflate"(5), " " and " zlib"(5)
+.SH AUTHOR
+Glenn Randers-Pehrson
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/png.5 b/libraries/irrlicht-1.8/source/Irrlicht/libpng/png.5
new file mode 100644
index 0000000..6df917d
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/png.5
@@ -0,0 +1,74 @@
+.TH PNG 5 "February 18, 2012"
+.SH NAME
+png \- Portable Network Graphics (PNG) format
+.SH DESCRIPTION
+PNG (Portable Network Graphics) is an extensible file format for the
+lossless, portable, well-compressed storage of raster images. PNG provides
+a patent-free replacement for GIF and can also replace many
+common uses of TIFF. Indexed-color, grayscale, and truecolor images are
+supported, plus an optional alpha channel. Sample depths range from
+1 to 16 bits.
+.br
+PNG is designed to work well in online viewing applications, such as the
+World Wide Web, so it is fully streamable with a progressive display
+option. PNG is robust, providing both full file integrity checking and
+fast, simple detection of common transmission errors. Also, PNG can store
+gamma and chromaticity data for improved color matching on heterogeneous
+platforms.
+.SH "SEE ALSO"
+.BR "libpng"(3), " libpngpf"(3), " zlib"(3), " deflate"(5), " " and " zlib"(5)
+.LP
+PNG specification (second edition), November 2003:
+.IP
+.br
+  <http://www.w3.org/TR/2003/REC-PNG-20031110/
+PNG 1.2 specification, July 1999:
+.IP
+.br
+http://www.libpng.org/pub/png
+.LP
+PNG 1.0 specification, October 1996:
+.IP
+.br
+RFC 2083
+.IP
+.br
+ftp://ds.internic.net/rfc/rfc2083.txt
+.br
+or (as a W3C Recommendation) at
+.br
+http://www.w3.org/TR/REC-png.html
+.SH AUTHORS
+This man page: Glenn Randers-Pehrson
+.LP
+Portable Network Graphics (PNG) Specification (Second Edition)
+Information technology - Computer graphics and image processing -
+Portable Network Graphics (PNG): Functional specification.
+ISO/IEC 15948:2003 (E) (November 10, 2003): David Duce and others.
+.LP
+Portable Network Graphics (PNG) Specification Version 1.2 (July 8, 1999):
+Glenn Randers-Pehrson and others (png-list).
+.LP
+Portable Network Graphics (PNG) Specification Version 1.0 (October 1, 1996):
+Thomas Boutell and others (png-list).
+.LP
+.SH COPYRIGHT NOTICE
+.LP
+This man page is Copyright (c) 1998-2006 Glenn Randers-Pehrson.  See png.h
+for conditions of use and distribution.
+.LP
+The PNG Specification (Second Edition) is
+Copyright (c) 2003 W3C. (MIT, ERCIM, Keio), All Rights Reserved.
+.LP
+The PNG-1.2 specification is copyright (c) 1999 Glenn Randers-Pehrson.
+See the specification for conditions of use and distribution.
+.LP
+The PNG-1.0 specification is copyright (c) 1996 Massachusetts Institute of
+Technology.  See the specification for conditions of use and distribution.
+.LP
+.\" end of man page
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/png.c b/libraries/irrlicht-1.8/source/Irrlicht/libpng/png.c
new file mode 100644
index 0000000..5a490b2
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/png.c
@@ -0,0 +1,2870 @@
+/* png.c - location for general purpose libpng functions
+ *
+ * Last changed in libpng 1.5.7 [December 15, 2011]
+ * Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+#include "pngpriv.h"
+/* Generate a compiler error if there is an old png.h in the search path. */
+typedef png_libpng_version_1_5_9 Your_png_h_is_not_version_1_5_9;
+/* Tells libpng that we have already handled the first "num_bytes" bytes
+ * of the PNG file signature.  If the PNG data is embedded into another
+ * stream we can set num_bytes = 8 so that libpng will not attempt to read
+ * or write any of the magic bytes before it starts on the IHDR.
+ */
+#ifdef PNG_READ_SUPPORTED
+void PNGAPI
+png_set_sig_bytes(png_structp png_ptr, int num_bytes)
+{
+   png_debug(1, "in png_set_sig_bytes");
+   if (png_ptr == NULL)
+      return;
+   if (num_bytes > 8)
+      png_error(png_ptr, "Too many bytes for PNG signature");
+   png_ptr->sig_bytes = (png_byte)(num_bytes < 0 ? 0 : num_bytes);
+}
+/* Checks whether the supplied bytes match the PNG signature.  We allow
+ * checking less than the full 8-byte signature so that those apps that
+ * already read the first few bytes of a file to determine the file type
+ * can simply check the remaining bytes for extra assurance.  Returns
+ * an integer less than, equal to, or greater than zero if sig is found,
+ * respectively, to be less than, to match, or be greater than the correct
+ * PNG signature (this is the same behavior as strcmp, memcmp, etc).
+ */
+int PNGAPI
+png_sig_cmp(png_const_bytep sig, png_size_t start, png_size_t num_to_check)
+{
+   png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};
+   if (num_to_check > 8)
+      num_to_check = 8;
+   else if (num_to_check < 1)
+      return (-1);
+   if (start > 7)
+      return (-1);
+   if (start + num_to_check > 8)
+      num_to_check = 8 - start;
+   return ((int)(png_memcmp(&sig[start], &png_signature[start], num_to_check)));
+}
+#endif /* PNG_READ_SUPPORTED */
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+/* Function to allocate memory for zlib */
+PNG_FUNCTION(voidpf /* PRIVATE */,
+png_zalloc,(voidpf png_ptr, uInt items, uInt size),PNG_ALLOCATED)
+{
+   png_voidp ptr;
+   png_structp p=(png_structp)png_ptr;
+   png_uint_32 save_flags=p->flags;
+   png_alloc_size_t num_bytes;
+   if (png_ptr == NULL)
+      return (NULL);
+   if (items > PNG_UINT_32_MAX/size)
+   {
+     png_warning (p, "Potential overflow in png_zalloc()");
+     return (NULL);
+   }
+   num_bytes = (png_alloc_size_t)items * size;
+   p->flags|=PNG_FLAG_MALLOC_NULL_MEM_OK;
+   ptr = (png_voidp)png_malloc((png_structp)png_ptr, num_bytes);
+   p->flags=save_flags;
+   return ((voidpf)ptr);
+}
+/* Function to free memory for zlib */
+void /* PRIVATE */
+png_zfree(voidpf png_ptr, voidpf ptr)
+{
+   png_free((png_structp)png_ptr, (png_voidp)ptr);
+}
+/* Reset the CRC variable to 32 bits of 1's.  Care must be taken
+ * in case CRC is > 32 bits to leave the top bits 0.
+ */
+void /* PRIVATE */
+png_reset_crc(png_structp png_ptr)
+{
+   /* The cast is safe because the crc is a 32 bit value. */
+   png_ptr->crc = (png_uint_32)crc32(0, Z_NULL, 0);
+}
+/* Calculate the CRC over a section of data.  We can only pass as
+ * much data to this routine as the largest single buffer size.  We
+ * also check that this data will actually be used before going to the
+ * trouble of calculating it.
+ */
+void /* PRIVATE */
+png_calculate_crc(png_structp png_ptr, png_const_bytep ptr, png_size_t length)
+{
+   int need_crc = 1;
+   if (PNG_CHUNK_ANCILLIARY(png_ptr->chunk_name))
+   {
+      if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) ==
+          (PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN))
+         need_crc = 0;
+   }
+   else /* critical */
+   {
+      if (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE)
+         need_crc = 0;
+   }
+   /* 'uLong' is defined as unsigned long, this means that on some systems it is
+    * a 64 bit value.  crc32, however, returns 32 bits so the following cast is
+    * safe.  'uInt' may be no more than 16 bits, so it is necessary to perform a
+    * loop here.
+    */
+   if (need_crc && length > 0)
+   {
+      uLong crc = png_ptr->crc; /* Should never issue a warning */
+      do
+      {
+         uInt safeLength = (uInt)length;
+         if (safeLength == 0)
+            safeLength = (uInt)-1; /* evil, but safe */
+         crc = crc32(crc, ptr, safeLength);
+         /* The following should never issue compiler warnings, if they do the
+          * target system has characteristics that will probably violate other
+          * assumptions within the libpng code.
+          */
+         ptr += safeLength;
+         length -= safeLength;
+      }
+      while (length > 0);
+      /* And the following is always safe because the crc is only 32 bits. */
+      png_ptr->crc = (png_uint_32)crc;
+   }
+}
+/* Check a user supplied version number, called from both read and write
+ * functions that create a png_struct
+ */
+int
+png_user_version_check(png_structp png_ptr, png_const_charp user_png_ver)
+{
+   if (user_png_ver)
+   {
+      int i = 0;
+      do
+      {
+         if (user_png_ver[i] != png_libpng_ver[i])
+            png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
+      } while (png_libpng_ver[i++]);
+   }
+   else
+      png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
+   if (png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH)
+   {
+     /* Libpng 0.90 and later are binary incompatible with libpng 0.89, so
+      * we must recompile any applications that use any older library version.
+      * For versions after libpng 1.0, we will be compatible, so we need
+      * only check the first digit.
+      */
+      if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] ||
+          (user_png_ver[0] == '1' && user_png_ver[2] != png_libpng_ver[2]) ||
+          (user_png_ver[0] == '0' && user_png_ver[2] < '9'))
+      {
+#ifdef PNG_WARNINGS_SUPPORTED
+         size_t pos = 0;
+         char m[128];
+         pos = png_safecat(m, sizeof m, pos, "Application built with libpng-");
+         pos = png_safecat(m, sizeof m, pos, user_png_ver);
+         pos = png_safecat(m, sizeof m, pos, " but running with ");
+         pos = png_safecat(m, sizeof m, pos, png_libpng_ver);
+         png_warning(png_ptr, m);
+#endif
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+         png_ptr->flags = 0;
+#endif
+         return 0;
+      }
+   }
+   /* Success return. */
+   return 1;
+}
+/* Allocate the memory for an info_struct for the application.  We don't
+ * really need the png_ptr, but it could potentially be useful in the
+ * future.  This should be used in favour of malloc(png_sizeof(png_info))
+ * and png_info_init() so that applications that want to use a shared
+ * libpng don't have to be recompiled if png_info changes size.
+ */
+PNG_FUNCTION(png_infop,PNGAPI
+png_create_info_struct,(png_structp png_ptr),PNG_ALLOCATED)
+{
+   png_infop info_ptr;
+   png_debug(1, "in png_create_info_struct");
+   if (png_ptr == NULL)
+      return (NULL);
+#ifdef PNG_USER_MEM_SUPPORTED
+   info_ptr = (png_infop)png_create_struct_2(PNG_STRUCT_INFO,
+      png_ptr->malloc_fn, png_ptr->mem_ptr);
+#else
+   info_ptr = (png_infop)png_create_struct(PNG_STRUCT_INFO);
+#endif
+   if (info_ptr != NULL)
+      png_info_init_3(&info_ptr, png_sizeof(png_info));
+   return (info_ptr);
+}
+/* This function frees the memory associated with a single info struct.
+ * Normally, one would use either png_destroy_read_struct() or
+ * png_destroy_write_struct() to free an info struct, but this may be
+ * useful for some applications.
+ */
+void PNGAPI
+png_destroy_info_struct(png_structp png_ptr, png_infopp info_ptr_ptr)
+{
+   png_infop info_ptr = NULL;
+   png_debug(1, "in png_destroy_info_struct");
+   if (png_ptr == NULL)
+      return;
+   if (info_ptr_ptr != NULL)
+      info_ptr = *info_ptr_ptr;
+   if (info_ptr != NULL)
+   {
+      png_info_destroy(png_ptr, info_ptr);
+#ifdef PNG_USER_MEM_SUPPORTED
+      png_destroy_struct_2((png_voidp)info_ptr, png_ptr->free_fn,
+          png_ptr->mem_ptr);
+#else
+      png_destroy_struct((png_voidp)info_ptr);
+#endif
+      *info_ptr_ptr = NULL;
+   }
+}
+/* Initialize the info structure.  This is now an internal function (0.89)
+ * and applications using it are urged to use png_create_info_struct()
+ * instead.
+ */
+void PNGAPI
+png_info_init_3(png_infopp ptr_ptr, png_size_t png_info_struct_size)
+{
+   png_infop info_ptr = *ptr_ptr;
+   png_debug(1, "in png_info_init_3");
+   if (info_ptr == NULL)
+      return;
+   if (png_sizeof(png_info) > png_info_struct_size)
+   {
+      png_destroy_struct(info_ptr);
+      info_ptr = (png_infop)png_create_struct(PNG_STRUCT_INFO);
+      *ptr_ptr = info_ptr;
+   }
+   /* Set everything to 0 */
+   png_memset(info_ptr, 0, png_sizeof(png_info));
+}
+void PNGAPI
+png_data_freer(png_structp png_ptr, png_infop info_ptr,
+   int freer, png_uint_32 mask)
+{
+   png_debug(1, "in png_data_freer");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+   if (freer == PNG_DESTROY_WILL_FREE_DATA)
+      info_ptr->free_me |= mask;
+   else if (freer == PNG_USER_WILL_FREE_DATA)
+      info_ptr->free_me &= ~mask;
+   else
+      png_warning(png_ptr,
+         "Unknown freer parameter in png_data_freer");
+}
+void PNGAPI
+png_free_data(png_structp png_ptr, png_infop info_ptr, png_uint_32 mask,
+   int num)
+{
+   png_debug(1, "in png_free_data");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+#ifdef PNG_TEXT_SUPPORTED
+   /* Free text item num or (if num == -1) all text items */
+   if ((mask & PNG_FREE_TEXT) & info_ptr->free_me)
+   {
+      if (num != -1)
+      {
+         if (info_ptr->text && info_ptr->text[num].key)
+         {
+            png_free(png_ptr, info_ptr->text[num].key);
+            info_ptr->text[num].key = NULL;
+         }
+      }
+      else
+      {
+         int i;
+         for (i = 0; i < info_ptr->num_text; i++)
+             png_free_data(png_ptr, info_ptr, PNG_FREE_TEXT, i);
+         png_free(png_ptr, info_ptr->text);
+         info_ptr->text = NULL;
+         info_ptr->num_text=0;
+      }
+   }
+#endif
+#ifdef PNG_tRNS_SUPPORTED
+   /* Free any tRNS entry */
+   if ((mask & PNG_FREE_TRNS) & info_ptr->free_me)
+   {
+      png_free(png_ptr, info_ptr->trans_alpha);
+      info_ptr->trans_alpha = NULL;
+      info_ptr->valid &= ~PNG_INFO_tRNS;
+   }
+#endif
+#ifdef PNG_sCAL_SUPPORTED
+   /* Free any sCAL entry */
+   if ((mask & PNG_FREE_SCAL) & info_ptr->free_me)
+   {
+      png_free(png_ptr, info_ptr->scal_s_width);
+      png_free(png_ptr, info_ptr->scal_s_height);
+      info_ptr->scal_s_width = NULL;
+      info_ptr->scal_s_height = NULL;
+      info_ptr->valid &= ~PNG_INFO_sCAL;
+   }
+#endif
+#ifdef PNG_pCAL_SUPPORTED
+   /* Free any pCAL entry */
+   if ((mask & PNG_FREE_PCAL) & info_ptr->free_me)
+   {
+      png_free(png_ptr, info_ptr->pcal_purpose);
+      png_free(png_ptr, info_ptr->pcal_units);
+      info_ptr->pcal_purpose = NULL;
+      info_ptr->pcal_units = NULL;
+      if (info_ptr->pcal_params != NULL)
+         {
+            int i;
+            for (i = 0; i < (int)info_ptr->pcal_nparams; i++)
+            {
+               png_free(png_ptr, info_ptr->pcal_params[i]);
+               info_ptr->pcal_params[i] = NULL;
+            }
+            png_free(png_ptr, info_ptr->pcal_params);
+            info_ptr->pcal_params = NULL;
+         }
+      info_ptr->valid &= ~PNG_INFO_pCAL;
+   }
+#endif
+#ifdef PNG_iCCP_SUPPORTED
+   /* Free any iCCP entry */
+   if ((mask & PNG_FREE_ICCP) & info_ptr->free_me)
+   {
+      png_free(png_ptr, info_ptr->iccp_name);
+      png_free(png_ptr, info_ptr->iccp_profile);
+      info_ptr->iccp_name = NULL;
+      info_ptr->iccp_profile = NULL;
+      info_ptr->valid &= ~PNG_INFO_iCCP;
+   }
+#endif
+#ifdef PNG_sPLT_SUPPORTED
+   /* Free a given sPLT entry, or (if num == -1) all sPLT entries */
+   if ((mask & PNG_FREE_SPLT) & info_ptr->free_me)
+   {
+      if (num != -1)
+      {
+         if (info_ptr->splt_palettes)
+         {
+            png_free(png_ptr, info_ptr->splt_palettes[num].name);
+            png_free(png_ptr, info_ptr->splt_palettes[num].entries);
+            info_ptr->splt_palettes[num].name = NULL;
+            info_ptr->splt_palettes[num].entries = NULL;
+         }
+      }
+      else
+      {
+         if (info_ptr->splt_palettes_num)
+         {
+            int i;
+            for (i = 0; i < (int)info_ptr->splt_palettes_num; i++)
+               png_free_data(png_ptr, info_ptr, PNG_FREE_SPLT, i);
+            png_free(png_ptr, info_ptr->splt_palettes);
+            info_ptr->splt_palettes = NULL;
+            info_ptr->splt_palettes_num = 0;
+         }
+         info_ptr->valid &= ~PNG_INFO_sPLT;
+      }
+   }
+#endif
+#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
+   if (png_ptr->unknown_chunk.data)
+   {
+      png_free(png_ptr, png_ptr->unknown_chunk.data);
+      png_ptr->unknown_chunk.data = NULL;
+   }
+   if ((mask & PNG_FREE_UNKN) & info_ptr->free_me)
+   {
+      if (num != -1)
+      {
+          if (info_ptr->unknown_chunks)
+          {
+             png_free(png_ptr, info_ptr->unknown_chunks[num].data);
+             info_ptr->unknown_chunks[num].data = NULL;
+          }
+      }
+      else
+      {
+         int i;
+         if (info_ptr->unknown_chunks_num)
+         {
+            for (i = 0; i < info_ptr->unknown_chunks_num; i++)
+               png_free_data(png_ptr, info_ptr, PNG_FREE_UNKN, i);
+            png_free(png_ptr, info_ptr->unknown_chunks);
+            info_ptr->unknown_chunks = NULL;
+            info_ptr->unknown_chunks_num = 0;
+         }
+      }
+   }
+#endif
+#ifdef PNG_hIST_SUPPORTED
+   /* Free any hIST entry */
+   if ((mask & PNG_FREE_HIST)  & info_ptr->free_me)
+   {
+      png_free(png_ptr, info_ptr->hist);
+      info_ptr->hist = NULL;
+      info_ptr->valid &= ~PNG_INFO_hIST;
+   }
+#endif
+   /* Free any PLTE entry that was internally allocated */
+   if ((mask & PNG_FREE_PLTE) & info_ptr->free_me)
+   {
+      png_zfree(png_ptr, info_ptr->palette);
+      info_ptr->palette = NULL;
+      info_ptr->valid &= ~PNG_INFO_PLTE;
+      info_ptr->num_palette = 0;
+   }
+#ifdef PNG_INFO_IMAGE_SUPPORTED
+   /* Free any image bits attached to the info structure */
+   if ((mask & PNG_FREE_ROWS) & info_ptr->free_me)
+   {
+      if (info_ptr->row_pointers)
+      {
+         int row;
+         for (row = 0; row < (int)info_ptr->height; row++)
+         {
+            png_free(png_ptr, info_ptr->row_pointers[row]);
+            info_ptr->row_pointers[row] = NULL;
+         }
+         png_free(png_ptr, info_ptr->row_pointers);
+         info_ptr->row_pointers = NULL;
+      }
+      info_ptr->valid &= ~PNG_INFO_IDAT;
+   }
+#endif
+   if (num != -1)
+      mask &= ~PNG_FREE_MUL;
+   info_ptr->free_me &= ~mask;
+}
+/* This is an internal routine to free any memory that the info struct is
+ * pointing to before re-using it or freeing the struct itself.  Recall
+ * that png_free() checks for NULL pointers for us.
+ */
+void /* PRIVATE */
+png_info_destroy(png_structp png_ptr, png_infop info_ptr)
+{
+   png_debug(1, "in png_info_destroy");
+   png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1);
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+   if (png_ptr->num_chunk_list)
+   {
+      png_free(png_ptr, png_ptr->chunk_list);
+      png_ptr->chunk_list = NULL;
+      png_ptr->num_chunk_list = 0;
+   }
+#endif
+   png_info_init_3(&info_ptr, png_sizeof(png_info));
+}
+#endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */
+/* This function returns a pointer to the io_ptr associated with the user
+ * functions.  The application should free any memory associated with this
+ * pointer before png_write_destroy() or png_read_destroy() are called.
+ */
+png_voidp PNGAPI
+png_get_io_ptr(png_structp png_ptr)
+{
+   if (png_ptr == NULL)
+      return (NULL);
+   return (png_ptr->io_ptr);
+}
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+#  ifdef PNG_STDIO_SUPPORTED
+/* Initialize the default input/output functions for the PNG file.  If you
+ * use your own read or write routines, you can call either png_set_read_fn()
+ * or png_set_write_fn() instead of png_init_io().  If you have defined
+ * PNG_NO_STDIO or otherwise disabled PNG_STDIO_SUPPORTED, you must use a
+ * function of your own because "FILE *" isn't necessarily available.
+ */
+void PNGAPI
+png_init_io(png_structp png_ptr, png_FILE_p fp)
+{
+   png_debug(1, "in png_init_io");
+   if (png_ptr == NULL)
+      return;
+   png_ptr->io_ptr = (png_voidp)fp;
+}
+#  endif
+#  ifdef PNG_TIME_RFC1123_SUPPORTED
+/* Convert the supplied time into an RFC 1123 string suitable for use in
+ * a "Creation Time" or other text-based time string.
+ */
+png_const_charp PNGAPI
+png_convert_to_rfc1123(png_structp png_ptr, png_const_timep ptime)
+{
+   static PNG_CONST char short_months[12][4] =
+        {"Jan", "Feb", "Mar", "Apr", "May", "Jun",
+         "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};
+   if (png_ptr == NULL)
+      return (NULL);
+   if (ptime->year > 9999 /* RFC1123 limitation */ ||
+       ptime->month == 0    ||  ptime->month > 12  ||
+       ptime->day   == 0    ||  ptime->day   > 31  ||
+       ptime->hour  > 23    ||  ptime->minute > 59 ||
+       ptime->second > 60)
+   {
+      png_warning(png_ptr, "Ignoring invalid time value");
+      return (NULL);
+   }
+   {
+      size_t pos = 0;
+      char number_buf[5]; /* enough for a four-digit year */
+#     define APPEND_STRING(string)\
+         pos = png_safecat(png_ptr->time_buffer, sizeof png_ptr->time_buffer,\
+            pos, (string))
+#     define APPEND_NUMBER(format, value)\
+         APPEND_STRING(PNG_FORMAT_NUMBER(number_buf, format, (value)))
+#     define APPEND(ch)\
+         if (pos < (sizeof png_ptr->time_buffer)-1)\
+            png_ptr->time_buffer[pos++] = (ch)
+      APPEND_NUMBER(PNG_NUMBER_FORMAT_u, (unsigned)ptime->day);
+      APPEND(' ');
+      APPEND_STRING(short_months[(ptime->month - 1)]);
+      APPEND(' ');
+      APPEND_NUMBER(PNG_NUMBER_FORMAT_u, ptime->year);
+      APPEND(' ');
+      APPEND_NUMBER(PNG_NUMBER_FORMAT_02u, (unsigned)ptime->hour);
+      APPEND(':');
+      APPEND_NUMBER(PNG_NUMBER_FORMAT_02u, (unsigned)ptime->minute);
+      APPEND(':');
+      APPEND_NUMBER(PNG_NUMBER_FORMAT_02u, (unsigned)ptime->second);
+      APPEND_STRING(" +0000"); /* This reliably terminates the buffer */
+#     undef APPEND
+#     undef APPEND_NUMBER
+#     undef APPEND_STRING
+   }
+   return png_ptr->time_buffer;
+}
+#  endif /* PNG_TIME_RFC1123_SUPPORTED */
+#endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */
+png_const_charp PNGAPI
+png_get_copyright(png_const_structp png_ptr)
+{
+   PNG_UNUSED(png_ptr)  /* Silence compiler warning about unused png_ptr */
+#ifdef PNG_STRING_COPYRIGHT
+   return PNG_STRING_COPYRIGHT
+#else
+#  ifdef __STDC__
+   return PNG_STRING_NEWLINE \
+     "libpng version 1.5.9 - February 18, 2012" PNG_STRING_NEWLINE \
+     "Copyright (c) 1998-2011 Glenn Randers-Pehrson" PNG_STRING_NEWLINE \
+     "Copyright (c) 1996-1997 Andreas Dilger" PNG_STRING_NEWLINE \
+     "Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc." \
+     PNG_STRING_NEWLINE;
+#  else
+      return "libpng version 1.5.9 - February 18, 2012\
+      Copyright (c) 1998-2011 Glenn Randers-Pehrson\
+      Copyright (c) 1996-1997 Andreas Dilger\
+      Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.";
+#  endif
+#endif
+}
+/* The following return the library version as a short string in the
+ * format 1.0.0 through 99.99.99zz.  To get the version of *.h files
+ * used with your application, print out PNG_LIBPNG_VER_STRING, which
+ * is defined in png.h.
+ * Note: now there is no difference between png_get_libpng_ver() and
+ * png_get_header_ver().  Due to the version_nn_nn_nn typedef guard,
+ * it is guaranteed that png.c uses the correct version of png.h.
+ */
+png_const_charp PNGAPI
+png_get_libpng_ver(png_const_structp png_ptr)
+{
+   /* Version of *.c files used when building libpng */
+   return png_get_header_ver(png_ptr);
+}
+png_const_charp PNGAPI
+png_get_header_ver(png_const_structp png_ptr)
+{
+   /* Version of *.h files used when building libpng */
+   PNG_UNUSED(png_ptr)  /* Silence compiler warning about unused png_ptr */
+   return PNG_LIBPNG_VER_STRING;
+}
+png_const_charp PNGAPI
+png_get_header_version(png_const_structp png_ptr)
+{
+   /* Returns longer string containing both version and date */
+   PNG_UNUSED(png_ptr)  /* Silence compiler warning about unused png_ptr */
+#ifdef __STDC__
+   return PNG_HEADER_VERSION_STRING
+#  ifndef PNG_READ_SUPPORTED
+   "     (NO READ SUPPORT)"
+#  endif
+   PNG_STRING_NEWLINE;
+#else
+   return PNG_HEADER_VERSION_STRING;
+#endif
+}
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+int PNGAPI
+png_handle_as_unknown(png_structp png_ptr, png_const_bytep chunk_name)
+{
+   /* Check chunk_name and return "keep" value if it's on the list, else 0 */
+   png_const_bytep p, p_end;
+   if (png_ptr == NULL || chunk_name == NULL || png_ptr->num_chunk_list <= 0)
+      return PNG_HANDLE_CHUNK_AS_DEFAULT;
+   p_end = png_ptr->chunk_list;
+   p = p_end + png_ptr->num_chunk_list*5; /* beyond end */
+   /* The code is the fifth byte after each four byte string.  Historically this
+    * code was always searched from the end of the list, so it should continue
+    * to do so in case there are duplicated entries.
+    */
+   do /* num_chunk_list > 0, so at least one */
+   {
+      p -= 5;
+      if (!png_memcmp(chunk_name, p, 4))
+         return p[4];
+   }
+   while (p > p_end);
+   return PNG_HANDLE_CHUNK_AS_DEFAULT;
+}
+int /* PRIVATE */
+png_chunk_unknown_handling(png_structp png_ptr, png_uint_32 chunk_name)
+{
+   png_byte chunk_string[5];
+   PNG_CSTRING_FROM_CHUNK(chunk_string, chunk_name);
+   return png_handle_as_unknown(png_ptr, chunk_string);
+}
+#endif
+#ifdef PNG_READ_SUPPORTED
+/* This function, added to libpng-1.0.6g, is untested. */
+int PNGAPI
+png_reset_zstream(png_structp png_ptr)
+{
+   if (png_ptr == NULL)
+      return Z_STREAM_ERROR;
+   return (inflateReset(&png_ptr->zstream));
+}
+#endif /* PNG_READ_SUPPORTED */
+/* This function was added to libpng-1.0.7 */
+png_uint_32 PNGAPI
+png_access_version_number(void)
+{
+   /* Version of *.c files used when building libpng */
+   return((png_uint_32)PNG_LIBPNG_VER);
+}
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+/* png_convert_size: a PNGAPI but no longer in png.h, so deleted
+ * at libpng 1.5.5!
+ */
+/* Added at libpng version 1.2.34 and 1.4.0 (moved from pngset.c) */
+#  ifdef PNG_CHECK_cHRM_SUPPORTED
+int /* PRIVATE */
+png_check_cHRM_fixed(png_structp png_ptr,
+   png_fixed_point white_x, png_fixed_point white_y, png_fixed_point red_x,
+   png_fixed_point red_y, png_fixed_point green_x, png_fixed_point green_y,
+   png_fixed_point blue_x, png_fixed_point blue_y)
+{
+   int ret = 1;
+   unsigned long xy_hi,xy_lo,yx_hi,yx_lo;
+   png_debug(1, "in function png_check_cHRM_fixed");
+   if (png_ptr == NULL)
+      return 0;
+   /* (x,y,z) values are first limited to 0..100000 (PNG_FP_1), the white
+    * y must also be greater than 0.  To test for the upper limit calculate
+    * (PNG_FP_1-y) - x must be <= to this for z to be >= 0 (and the expression
+    * cannot overflow.)  At this point we know x and y are >= 0 and (x+y) is
+    * <= PNG_FP_1.  The previous test on PNG_MAX_UINT_31 is removed because it
+    * pointless (and it produces compiler warnings!)
+    */
+   if (white_x < 0 || white_y <= 0 ||
+         red_x < 0 ||   red_y <  0 ||
+       green_x < 0 || green_y <  0 ||
+        blue_x < 0 ||  blue_y <  0)
+   {
+      png_warning(png_ptr,
+        "Ignoring attempt to set negative chromaticity value");
+      ret = 0;
+   }
+   /* And (x+y) must be <= PNG_FP_1 (so z is >= 0) */
+   if (white_x > PNG_FP_1 - white_y)
+   {
+      png_warning(png_ptr, "Invalid cHRM white point");
+      ret = 0;
+   }
+   if (red_x > PNG_FP_1 - red_y)
+   {
+      png_warning(png_ptr, "Invalid cHRM red point");
+      ret = 0;
+   }
+   if (green_x > PNG_FP_1 - green_y)
+   {
+      png_warning(png_ptr, "Invalid cHRM green point");
+      ret = 0;
+   }
+   if (blue_x > PNG_FP_1 - blue_y)
+   {
+      png_warning(png_ptr, "Invalid cHRM blue point");
+      ret = 0;
+   }
+   png_64bit_product(green_x - red_x, blue_y - red_y, &xy_hi, &xy_lo);
+   png_64bit_product(green_y - red_y, blue_x - red_x, &yx_hi, &yx_lo);
+   if (xy_hi == yx_hi && xy_lo == yx_lo)
+   {
+      png_warning(png_ptr,
+         "Ignoring attempt to set cHRM RGB triangle with zero area");
+      ret = 0;
+   }
+   return ret;
+}
+#  endif /* PNG_CHECK_cHRM_SUPPORTED */
+#ifdef PNG_cHRM_SUPPORTED
+/* Added at libpng-1.5.5 to support read and write of true CIEXYZ values for
+ * cHRM, as opposed to using chromaticities.  These internal APIs return
+ * non-zero on a parameter error.  The X, Y and Z values are required to be
+ * positive and less than 1.0.
+ */
+int png_xy_from_XYZ(png_xy *xy, png_XYZ XYZ)
+{
+   png_int_32 d, dwhite, whiteX, whiteY;
+   d = XYZ.redX + XYZ.redY + XYZ.redZ;
+   if (!png_muldiv(&xy->redx, XYZ.redX, PNG_FP_1, d)) return 1;
+   if (!png_muldiv(&xy->redy, XYZ.redY, PNG_FP_1, d)) return 1;
+   dwhite = d;
+   whiteX = XYZ.redX;
+   whiteY = XYZ.redY;
+   d = XYZ.greenX + XYZ.greenY + XYZ.greenZ;
+   if (!png_muldiv(&xy->greenx, XYZ.greenX, PNG_FP_1, d)) return 1;
+   if (!png_muldiv(&xy->greeny, XYZ.greenY, PNG_FP_1, d)) return 1;
+   dwhite += d;
+   whiteX += XYZ.greenX;
+   whiteY += XYZ.greenY;
+   d = XYZ.blueX + XYZ.blueY + XYZ.blueZ;
+   if (!png_muldiv(&xy->bluex, XYZ.blueX, PNG_FP_1, d)) return 1;
+   if (!png_muldiv(&xy->bluey, XYZ.blueY, PNG_FP_1, d)) return 1;
+   dwhite += d;
+   whiteX += XYZ.blueX;
+   whiteY += XYZ.blueY;
+   /* The reference white is simply the same of the end-point (X,Y,Z) vectors,
+    * thus:
+    */
+   if (!png_muldiv(&xy->whitex, whiteX, PNG_FP_1, dwhite)) return 1;
+   if (!png_muldiv(&xy->whitey, whiteY, PNG_FP_1, dwhite)) return 1;
+   return 0;
+}
+int png_XYZ_from_xy(png_XYZ *XYZ, png_xy xy)
+{
+   png_fixed_point red_inverse, green_inverse, blue_scale;
+   png_fixed_point left, right, denominator;
+   /* Check xy and, implicitly, z.  Note that wide gamut color spaces typically
+    * have end points with 0 tristimulus values (these are impossible end
+    * points, but they are used to cover the possible colors.)
+    */
+   if (xy.redx < 0 || xy.redx > PNG_FP_1) return 1;
+   if (xy.redy < 0 || xy.redy > PNG_FP_1-xy.redx) return 1;
+   if (xy.greenx < 0 || xy.greenx > PNG_FP_1) return 1;
+   if (xy.greeny < 0 || xy.greeny > PNG_FP_1-xy.greenx) return 1;
+   if (xy.bluex < 0 || xy.bluex > PNG_FP_1) return 1;
+   if (xy.bluey < 0 || xy.bluey > PNG_FP_1-xy.bluex) return 1;
+   if (xy.whitex < 0 || xy.whitex > PNG_FP_1) return 1;
+   if (xy.whitey < 0 || xy.whitey > PNG_FP_1-xy.whitex) return 1;
+   /* The reverse calculation is more difficult because the original tristimulus
+    * value had 9 independent values (red,green,blue)x(X,Y,Z) however only 8
+    * derived values were recorded in the cHRM chunk;
+    * (red,green,blue,white)x(x,y).  This loses one degree of freedom and
+    * therefore an arbitrary ninth value has to be introduced to undo the
+    * original transformations.
+    *
+    * Think of the original end-points as points in (X,Y,Z) space.  The
+    * chromaticity values (c) have the property:
+    *
+    *           C
+    *   c = ---------
+    *       X + Y + Z
+    *
+    * For each c (x,y,z) from the corresponding original C (X,Y,Z).  Thus the
+    * three chromaticity values (x,y,z) for each end-point obey the
+    * relationship:
+    *
+    *   x + y + z = 1
+    *
+    * This describes the plane in (X,Y,Z) space that intersects each axis at the
+    * value 1.0; call this the chromaticity plane.  Thus the chromaticity
+    * calculation has scaled each end-point so that it is on the x+y+z=1 plane
+    * and chromaticity is the intersection of the vector from the origin to the
+    * (X,Y,Z) value with the chromaticity plane.
+    *
+    * To fully invert the chromaticity calculation we would need the three
+    * end-point scale factors, (red-scale, green-scale, blue-scale), but these
+    * were not recorded.  Instead we calculated the reference white (X,Y,Z) and
+    * recorded the chromaticity of this.  The reference white (X,Y,Z) would have
+    * given all three of the scale factors since:
+    *
+    *    color-C = color-c * color-scale
+    *    white-C = red-C + green-C + blue-C
+    *            = red-c*red-scale + green-c*green-scale + blue-c*blue-scale
+    *
+    * But cHRM records only white-x and white-y, so we have lost the white scale
+    * factor:
+    *
+    *    white-C = white-c*white-scale
+    *
+    * To handle this the inverse transformation makes an arbitrary assumption
+    * about white-scale:
+    *
+    *    Assume: white-Y = 1.0
+    *    Hence:  white-scale = 1/white-y
+    *    Or:     red-Y + green-Y + blue-Y = 1.0
+    *
+    * Notice the last statement of the assumption gives an equation in three of
+    * the nine values we want to calculate.  8 more equations come from the
+    * above routine as summarised at the top above (the chromaticity
+    * calculation):
+    *
+    *    Given: color-x = color-X / (color-X + color-Y + color-Z)
+    *    Hence: (color-x - 1)*color-X + color.x*color-Y + color.x*color-Z = 0
+    *
+    * This is 9 simultaneous equations in the 9 variables "color-C" and can be
+    * solved by Cramer's rule.  Cramer's rule requires calculating 10 9x9 matrix
+    * determinants, however this is not as bad as it seems because only 28 of
+    * the total of 90 terms in the various matrices are non-zero.  Nevertheless
+    * Cramer's rule is notoriously numerically unstable because the determinant
+    * calculation involves the difference of large, but similar, numbers.  It is
+    * difficult to be sure that the calculation is stable for real world values
+    * and it is certain that it becomes unstable where the end points are close
+    * together.
+    *
+    * So this code uses the perhaps slighly less optimal but more understandable
+    * and totally obvious approach of calculating color-scale.
+    *
+    * This algorithm depends on the precision in white-scale and that is
+    * (1/white-y), so we can immediately see that as white-y approaches 0 the
+    * accuracy inherent in the cHRM chunk drops off substantially.
+    *
+    * libpng arithmetic: a simple invertion of the above equations
+    * ------------------------------------------------------------
+    *
+    *    white_scale = 1/white-y
+    *    white-X = white-x * white-scale
+    *    white-Y = 1.0
+    *    white-Z = (1 - white-x - white-y) * white_scale
+    *
+    *    white-C = red-C + green-C + blue-C
+    *            = red-c*red-scale + green-c*green-scale + blue-c*blue-scale
+    *
+    * This gives us three equations in (red-scale,green-scale,blue-scale) where
+    * all the coefficients are now known:
+    *
+    *    red-x*red-scale + green-x*green-scale + blue-x*blue-scale
+    *       = white-x/white-y
+    *    red-y*red-scale + green-y*green-scale + blue-y*blue-scale = 1
+    *    red-z*red-scale + green-z*green-scale + blue-z*blue-scale
+    *       = (1 - white-x - white-y)/white-y
+    *
+    * In the last equation color-z is (1 - color-x - color-y) so we can add all
+    * three equations together to get an alternative third:
+    *
+    *    red-scale + green-scale + blue-scale = 1/white-y = white-scale
+    *
+    * So now we have a Cramer's rule solution where the determinants are just
+    * 3x3 - far more tractible.  Unfortunately 3x3 determinants still involve
+    * multiplication of three coefficients so we can't guarantee to avoid
+    * overflow in the libpng fixed point representation.  Using Cramer's rule in
+    * floating point is probably a good choice here, but it's not an option for
+    * fixed point.  Instead proceed to simplify the first two equations by
+    * eliminating what is likely to be the largest value, blue-scale:
+    *
+    *    blue-scale = white-scale - red-scale - green-scale
+    *
+    * Hence:
+    *
+    *    (red-x - blue-x)*red-scale + (green-x - blue-x)*green-scale =
+    *                (white-x - blue-x)*white-scale
+    *
+    *    (red-y - blue-y)*red-scale + (green-y - blue-y)*green-scale =
+    *                1 - blue-y*white-scale
+    *
+    * And now we can trivially solve for (red-scale,green-scale):
+    *
+    *    green-scale =
+    *                (white-x - blue-x)*white-scale - (red-x - blue-x)*red-scale
+    *                -----------------------------------------------------------
+    *                                  green-x - blue-x
+    *
+    *    red-scale =
+    *                1 - blue-y*white-scale - (green-y - blue-y) * green-scale
+    *                ---------------------------------------------------------
+    *                                  red-y - blue-y
+    *
+    * Hence:
+    *
+    *    red-scale =
+    *          ( (green-x - blue-x) * (white-y - blue-y) -
+    *            (green-y - blue-y) * (white-x - blue-x) ) / white-y
+    * -------------------------------------------------------------------------
+    *  (green-x - blue-x)*(red-y - blue-y)-(green-y - blue-y)*(red-x - blue-x)
+    *
+    *    green-scale =
+    *          ( (red-y - blue-y) * (white-x - blue-x) -
+    *            (red-x - blue-x) * (white-y - blue-y) ) / white-y
+    * -------------------------------------------------------------------------
+    *  (green-x - blue-x)*(red-y - blue-y)-(green-y - blue-y)*(red-x - blue-x)
+    *
+    * Accuracy:
+    * The input values have 5 decimal digits of accuracy.  The values are all in
+    * the range 0 < value < 1, so simple products are in the same range but may
+    * need up to 10 decimal digits to preserve the original precision and avoid
+    * underflow.  Because we are using a 32-bit signed representation we cannot
+    * match this; the best is a little over 9 decimal digits, less than 10.
+    *
+    * The approach used here is to preserve the maximum precision within the
+    * signed representation.  Because the red-scale calculation above uses the
+    * difference between two products of values that must be in the range -1..+1
+    * it is sufficient to divide the product by 7; ceil(100,000/32767*2).  The
+    * factor is irrelevant in the calculation because it is applied to both
+    * numerator and denominator.
+    *
+    * Note that the values of the differences of the products of the
+    * chromaticities in the above equations tend to be small, for example for
+    * the sRGB chromaticities they are:
+    *
+    * red numerator:    -0.04751
+    * green numerator:  -0.08788
+    * denominator:      -0.2241 (without white-y multiplication)
+    *
+    *  The resultant Y coefficients from the chromaticities of some widely used
+    *  color space definitions are (to 15 decimal places):
+    *
+    *  sRGB
+    *    0.212639005871510 0.715168678767756 0.072192315360734
+    *  Kodak ProPhoto
+    *    0.288071128229293 0.711843217810102 0.000085653960605
+    *  Adobe RGB
+    *    0.297344975250536 0.627363566255466 0.075291458493998
+    *  Adobe Wide Gamut RGB
+    *    0.258728243040113 0.724682314948566 0.016589442011321
+    */
+   /* By the argument, above overflow should be impossible here. The return
+    * value of 2 indicates an internal error to the caller.
+    */
+   if (!png_muldiv(&left, xy.greenx-xy.bluex, xy.redy - xy.bluey, 7)) return 2;
+   if (!png_muldiv(&right, xy.greeny-xy.bluey, xy.redx - xy.bluex, 7)) return 2;
+   denominator = left - right;
+   /* Now find the red numerator. */
+   if (!png_muldiv(&left, xy.greenx-xy.bluex, xy.whitey-xy.bluey, 7)) return 2;
+   if (!png_muldiv(&right, xy.greeny-xy.bluey, xy.whitex-xy.bluex, 7)) return 2;
+   /* Overflow is possible here and it indicates an extreme set of PNG cHRM
+    * chunk values.  This calculation actually returns the reciprocal of the
+    * scale value because this allows us to delay the multiplication of white-y
+    * into the denominator, which tends to produce a small number.
+    */
+   if (!png_muldiv(&red_inverse, xy.whitey, denominator, left-right) ||
+       red_inverse <= xy.whitey /* r+g+b scales = white scale */)
+      return 1;
+   /* Similarly for green_inverse: */
+   if (!png_muldiv(&left, xy.redy-xy.bluey, xy.whitex-xy.bluex, 7)) return 2;
+   if (!png_muldiv(&right, xy.redx-xy.bluex, xy.whitey-xy.bluey, 7)) return 2;
+   if (!png_muldiv(&green_inverse, xy.whitey, denominator, left-right) ||
+       green_inverse <= xy.whitey)
+      return 1;
+   /* And the blue scale, the checks above guarantee this can't overflow but it
+    * can still produce 0 for extreme cHRM values.
+    */
+   blue_scale = png_reciprocal(xy.whitey) - png_reciprocal(red_inverse) -
+      png_reciprocal(green_inverse);
+   if (blue_scale <= 0) return 1;
+   /* And fill in the png_XYZ: */
+   if (!png_muldiv(&XYZ->redX, xy.redx, PNG_FP_1, red_inverse)) return 1;
+   if (!png_muldiv(&XYZ->redY, xy.redy, PNG_FP_1, red_inverse)) return 1;
+   if (!png_muldiv(&XYZ->redZ, PNG_FP_1 - xy.redx - xy.redy, PNG_FP_1,
+      red_inverse))
+      return 1;
+   if (!png_muldiv(&XYZ->greenX, xy.greenx, PNG_FP_1, green_inverse)) return 1;
+   if (!png_muldiv(&XYZ->greenY, xy.greeny, PNG_FP_1, green_inverse)) return 1;
+   if (!png_muldiv(&XYZ->greenZ, PNG_FP_1 - xy.greenx - xy.greeny, PNG_FP_1,
+      green_inverse))
+      return 1;
+   if (!png_muldiv(&XYZ->blueX, xy.bluex, blue_scale, PNG_FP_1)) return 1;
+   if (!png_muldiv(&XYZ->blueY, xy.bluey, blue_scale, PNG_FP_1)) return 1;
+   if (!png_muldiv(&XYZ->blueZ, PNG_FP_1 - xy.bluex - xy.bluey, blue_scale,
+      PNG_FP_1))
+      return 1;
+   return 0; /*success*/
+}
+int png_XYZ_from_xy_checked(png_structp png_ptr, png_XYZ *XYZ, png_xy xy)
+{
+   switch (png_XYZ_from_xy(XYZ, xy))
+   {
+      case 0: /* success */
+         return 1;
+      case 1:
+         /* The chunk may be technically valid, but we got png_fixed_point
+          * overflow while trying to get XYZ values out of it.  This is
+          * entirely benign - the cHRM chunk is pretty extreme.
+          */
+         png_warning(png_ptr,
+            "extreme cHRM chunk cannot be converted to tristimulus values");
+         break;
+      default:
+         /* libpng is broken; this should be a warning but if it happens we
+          * want error reports so for the moment it is an error.
+          */
+         png_error(png_ptr, "internal error in png_XYZ_from_xy");
+         break;
+   }
+   /* ERROR RETURN */
+   return 0;
+}
+#endif
+void /* PRIVATE */
+png_check_IHDR(png_structp png_ptr,
+   png_uint_32 width, png_uint_32 height, int bit_depth,
+   int color_type, int interlace_type, int compression_type,
+   int filter_type)
+{
+   int error = 0;
+   /* Check for width and height valid values */
+   if (width == 0)
+   {
+      png_warning(png_ptr, "Image width is zero in IHDR");
+      error = 1;
+   }
+   if (height == 0)
+   {
+      png_warning(png_ptr, "Image height is zero in IHDR");
+      error = 1;
+   }
+#  ifdef PNG_SET_USER_LIMITS_SUPPORTED
+   if (width > png_ptr->user_width_max)
+#  else
+   if (width > PNG_USER_WIDTH_MAX)
+#  endif
+   {
+      png_warning(png_ptr, "Image width exceeds user limit in IHDR");
+      error = 1;
+   }
+#  ifdef PNG_SET_USER_LIMITS_SUPPORTED
+   if (height > png_ptr->user_height_max)
+#  else
+   if (height > PNG_USER_HEIGHT_MAX)
+#  endif
+   {
+      png_warning(png_ptr, "Image height exceeds user limit in IHDR");
+      error = 1;
+   }
+   if (width > PNG_UINT_31_MAX)
+   {
+      png_warning(png_ptr, "Invalid image width in IHDR");
+      error = 1;
+   }
+   if (height > PNG_UINT_31_MAX)
+   {
+      png_warning(png_ptr, "Invalid image height in IHDR");
+      error = 1;
+   }
+   if (width > (PNG_UINT_32_MAX
+                 >> 3)      /* 8-byte RGBA pixels */
+                 - 48       /* bigrowbuf hack */
+                 - 1        /* filter byte */
+                 - 7*8      /* rounding of width to multiple of 8 pixels */
+                 - 8)       /* extra max_pixel_depth pad */
+      png_warning(png_ptr, "Width is too large for libpng to process pixels");
+   /* Check other values */
+   if (bit_depth != 1 && bit_depth != 2 && bit_depth != 4 &&
+       bit_depth != 8 && bit_depth != 16)
+   {
+      png_warning(png_ptr, "Invalid bit depth in IHDR");
+      error = 1;
+   }
+   if (color_type < 0 || color_type == 1 ||
+       color_type == 5 || color_type > 6)
+   {
+      png_warning(png_ptr, "Invalid color type in IHDR");
+      error = 1;
+   }
+   if (((color_type == PNG_COLOR_TYPE_PALETTE) && bit_depth > 8) ||
+       ((color_type == PNG_COLOR_TYPE_RGB ||
+         color_type == PNG_COLOR_TYPE_GRAY_ALPHA ||
+         color_type == PNG_COLOR_TYPE_RGB_ALPHA) && bit_depth < 8))
+   {
+      png_warning(png_ptr, "Invalid color type/bit depth combination in IHDR");
+      error = 1;
+   }
+   if (interlace_type >= PNG_INTERLACE_LAST)
+   {
+      png_warning(png_ptr, "Unknown interlace method in IHDR");
+      error = 1;
+   }
+   if (compression_type != PNG_COMPRESSION_TYPE_BASE)
+   {
+      png_warning(png_ptr, "Unknown compression method in IHDR");
+      error = 1;
+   }
+#  ifdef PNG_MNG_FEATURES_SUPPORTED
+   /* Accept filter_method 64 (intrapixel differencing) only if
+    * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
+    * 2. Libpng did not read a PNG signature (this filter_method is only
+    *    used in PNG datastreams that are embedded in MNG datastreams) and
+    * 3. The application called png_permit_mng_features with a mask that
+    *    included PNG_FLAG_MNG_FILTER_64 and
+    * 4. The filter_method is 64 and
+    * 5. The color_type is RGB or RGBA
+    */
+   if ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) &&
+       png_ptr->mng_features_permitted)
+      png_warning(png_ptr, "MNG features are not allowed in a PNG datastream");
+   if (filter_type != PNG_FILTER_TYPE_BASE)
+   {
+      if (!((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
+          (filter_type == PNG_INTRAPIXEL_DIFFERENCING) &&
+          ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) == 0) &&
+          (color_type == PNG_COLOR_TYPE_RGB ||
+          color_type == PNG_COLOR_TYPE_RGB_ALPHA)))
+      {
+         png_warning(png_ptr, "Unknown filter method in IHDR");
+         error = 1;
+      }
+      if (png_ptr->mode & PNG_HAVE_PNG_SIGNATURE)
+      {
+         png_warning(png_ptr, "Invalid filter method in IHDR");
+         error = 1;
+      }
+   }
+#  else
+   if (filter_type != PNG_FILTER_TYPE_BASE)
+   {
+      png_warning(png_ptr, "Unknown filter method in IHDR");
+      error = 1;
+   }
+#  endif
+   if (error == 1)
+      png_error(png_ptr, "Invalid IHDR data");
+}
+#if defined(PNG_sCAL_SUPPORTED) || defined(PNG_pCAL_SUPPORTED)
+/* ASCII to fp functions */
+/* Check an ASCII formated floating point value, see the more detailed
+ * comments in pngpriv.h
+ */
+/* The following is used internally to preserve the sticky flags */
+#define png_fp_add(state, flags) ((state) |= (flags))
+#define png_fp_set(state, value) ((state) = (value) | ((state) & PNG_FP_STICKY))
+int /* PRIVATE */
+png_check_fp_number(png_const_charp string, png_size_t size, int *statep,
+   png_size_tp whereami)
+{
+   int state = *statep;
+   png_size_t i = *whereami;
+   while (i < size)
+   {
+      int type;
+      /* First find the type of the next character */
+      switch (string[i])
+      {
+      case 43:  type = PNG_FP_SAW_SIGN;                   break;
+      case 45:  type = PNG_FP_SAW_SIGN + PNG_FP_NEGATIVE; break;
+      case 46:  type = PNG_FP_SAW_DOT;                    break;
+      case 48:  type = PNG_FP_SAW_DIGIT;                  break;
+      case 49: case 50: case 51: case 52:
+      case 53: case 54: case 55: case 56:
+      case 57:  type = PNG_FP_SAW_DIGIT + PNG_FP_NONZERO; break;
+      case 69:
+      case 101: type = PNG_FP_SAW_E;                      break;
+      default:  goto PNG_FP_End;
+      }
+      /* Now deal with this type according to the current
+       * state, the type is arranged to not overlap the
+       * bits of the PNG_FP_STATE.
+       */
+      switch ((state & PNG_FP_STATE) + (type & PNG_FP_SAW_ANY))
+      {
+      case PNG_FP_INTEGER + PNG_FP_SAW_SIGN:
+         if (state & PNG_FP_SAW_ANY)
+            goto PNG_FP_End; /* not a part of the number */
+         png_fp_add(state, type);
+         break;
+      case PNG_FP_INTEGER + PNG_FP_SAW_DOT:
+         /* Ok as trailer, ok as lead of fraction. */
+         if (state & PNG_FP_SAW_DOT) /* two dots */
+            goto PNG_FP_End;
+         else if (state & PNG_FP_SAW_DIGIT) /* trailing dot? */
+            png_fp_add(state, type);
+         else
+            png_fp_set(state, PNG_FP_FRACTION | type);
+         break;
+      case PNG_FP_INTEGER + PNG_FP_SAW_DIGIT:
+         if (state & PNG_FP_SAW_DOT) /* delayed fraction */
+            png_fp_set(state, PNG_FP_FRACTION | PNG_FP_SAW_DOT);
+         png_fp_add(state, type | PNG_FP_WAS_VALID);
+         break;
+      case PNG_FP_INTEGER + PNG_FP_SAW_E:
+         if ((state & PNG_FP_SAW_DIGIT) == 0)
+            goto PNG_FP_End;
+         png_fp_set(state, PNG_FP_EXPONENT);
+         break;
+   /* case PNG_FP_FRACTION + PNG_FP_SAW_SIGN:
+         goto PNG_FP_End; ** no sign in fraction */
+   /* case PNG_FP_FRACTION + PNG_FP_SAW_DOT:
+         goto PNG_FP_End; ** Because SAW_DOT is always set */
+      case PNG_FP_FRACTION + PNG_FP_SAW_DIGIT:
+         png_fp_add(state, type | PNG_FP_WAS_VALID);
+         break;
+      case PNG_FP_FRACTION + PNG_FP_SAW_E:
+         /* This is correct because the trailing '.' on an
+          * integer is handled above - so we can only get here
+          * with the sequence ".E" (with no preceding digits).
+          */
+         if ((state & PNG_FP_SAW_DIGIT) == 0)
+            goto PNG_FP_End;
+         png_fp_set(state, PNG_FP_EXPONENT);
+         break;
+      case PNG_FP_EXPONENT + PNG_FP_SAW_SIGN:
+         if (state & PNG_FP_SAW_ANY)
+            goto PNG_FP_End; /* not a part of the number */
+         png_fp_add(state, PNG_FP_SAW_SIGN);
+         break;
+   /* case PNG_FP_EXPONENT + PNG_FP_SAW_DOT:
+         goto PNG_FP_End; */
+      case PNG_FP_EXPONENT + PNG_FP_SAW_DIGIT:
+         png_fp_add(state, PNG_FP_SAW_DIGIT | PNG_FP_WAS_VALID);
+         break;
+   /* case PNG_FP_EXPONEXT + PNG_FP_SAW_E:
+         goto PNG_FP_End; */
+      default: goto PNG_FP_End; /* I.e. break 2 */
+      }
+      /* The character seems ok, continue. */
+      ++i;
+   }
+PNG_FP_End:
+   /* Here at the end, update the state and return the correct
+    * return code.
+    */
+   *statep = state;
+   *whereami = i;
+   return (state & PNG_FP_SAW_DIGIT) != 0;
+}
+/* The same but for a complete string. */
+int
+png_check_fp_string(png_const_charp string, png_size_t size)
+{
+   int        state=0;
+   png_size_t char_index=0;
+   if (png_check_fp_number(string, size, &state, &char_index) &&
+      (char_index == size || string[char_index] == 0))
+      return state /* must be non-zero - see above */;
+   return 0; /* i.e. fail */
+}
+#endif /* pCAL or sCAL */
+#ifdef PNG_READ_sCAL_SUPPORTED
+#  ifdef PNG_FLOATING_POINT_SUPPORTED
+/* Utility used below - a simple accurate power of ten from an integral
+ * exponent.
+ */
+static double
+png_pow10(int power)
+{
+   int recip = 0;
+   double d = 1;
+   /* Handle negative exponent with a reciprocal at the end because
+    * 10 is exact whereas .1 is inexact in base 2
+    */
+   if (power < 0)
+   {
+      if (power < DBL_MIN_10_EXP) return 0;
+      recip = 1, power = -power;
+   }
+   if (power > 0)
+   {
+      /* Decompose power bitwise. */
+      double mult = 10;
+      do
+      {
+         if (power & 1) d *= mult;
+         mult *= mult;
+         power >>= 1;
+      }
+      while (power > 0);
+      if (recip) d = 1/d;
+   }
+   /* else power is 0 and d is 1 */
+   return d;
+}
+/* Function to format a floating point value in ASCII with a given
+ * precision.
+ */
+void /* PRIVATE */
+png_ascii_from_fp(png_structp png_ptr, png_charp ascii, png_size_t size,
+    double fp, unsigned int precision)
+{
+   /* We use standard functions from math.h, but not printf because
+    * that would require stdio.  The caller must supply a buffer of
+    * sufficient size or we will png_error.  The tests on size and
+    * the space in ascii[] consumed are indicated below.
+    */
+   if (precision < 1)
+      precision = DBL_DIG;
+   /* Enforce the limit of the implementation precision too. */
+   if (precision > DBL_DIG+1)
+      precision = DBL_DIG+1;
+   /* Basic sanity checks */
+   if (size >= precision+5) /* See the requirements below. */
+   {
+      if (fp < 0)
+      {
+         fp = -fp;
+         *ascii++ = 45; /* '-'  PLUS 1 TOTAL 1 */
+         --size;
+      }
+      if (fp >= DBL_MIN && fp <= DBL_MAX)
+      {
+         int exp_b10;       /* A base 10 exponent */
+         double base;   /* 10^exp_b10 */
+         /* First extract a base 10 exponent of the number,
+          * the calculation below rounds down when converting
+          * from base 2 to base 10 (multiply by log10(2) -
+          * 0.3010, but 77/256 is 0.3008, so exp_b10 needs to
+          * be increased.  Note that the arithmetic shift
+          * performs a floor() unlike C arithmetic - using a
+          * C multiply would break the following for negative
+          * exponents.
+          */
+         (void)frexp(fp, &exp_b10); /* exponent to base 2 */
+         exp_b10 = (exp_b10 * 77) >> 8; /* <= exponent to base 10 */
+         /* Avoid underflow here. */
+         base = png_pow10(exp_b10); /* May underflow */
+         while (base < DBL_MIN || base < fp)
+         {
+            /* And this may overflow. */
+            double test = png_pow10(exp_b10+1);
+            if (test <= DBL_MAX)
+               ++exp_b10, base = test;
+            else
+               break;
+         }
+         /* Normalize fp and correct exp_b10, after this fp is in the
+          * range [.1,1) and exp_b10 is both the exponent and the digit
+          * *before* which the decimal point should be inserted
+          * (starting with 0 for the first digit).  Note that this
+          * works even if 10^exp_b10 is out of range because of the
+          * test on DBL_MAX above.
+          */
+         fp /= base;
+         while (fp >= 1) fp /= 10, ++exp_b10;
+         /* Because of the code above fp may, at this point, be
+          * less than .1, this is ok because the code below can
+          * handle the leading zeros this generates, so no attempt
+          * is made to correct that here.
+          */
+         {
+            int czero, clead, cdigits;
+            char exponent[10];
+            /* Allow up to two leading zeros - this will not lengthen
+             * the number compared to using E-n.
+             */
+            if (exp_b10 < 0 && exp_b10 > -3) /* PLUS 3 TOTAL 4 */
+            {
+               czero = -exp_b10; /* PLUS 2 digits: TOTAL 3 */
+               exp_b10 = 0;      /* Dot added below before first output. */
+            }
+            else
+               czero = 0;    /* No zeros to add */
+            /* Generate the digit list, stripping trailing zeros and
+             * inserting a '.' before a digit if the exponent is 0.
+             */
+            clead = czero; /* Count of leading zeros */
+            cdigits = 0;   /* Count of digits in list. */
+            do
+            {
+               double d;
+               fp *= 10;
+               /* Use modf here, not floor and subtract, so that
+                * the separation is done in one step.  At the end
+                * of the loop don't break the number into parts so
+                * that the final digit is rounded.
+                */
+               if (cdigits+czero-clead+1 < (int)precision)
+                  fp = modf(fp, &d);
+               else
+               {
+                  d = floor(fp + .5);
+                  if (d > 9)
+                  {
+                     /* Rounding up to 10, handle that here. */
+                     if (czero > 0)
+                     {
+                        --czero, d = 1;
+                        if (cdigits == 0) --clead;
+                     }
+                     else
+                     {
+                        while (cdigits > 0 && d > 9)
+                        {
+                           int ch = *--ascii;
+                           if (exp_b10 != (-1))
+                              ++exp_b10;
+                           else if (ch == 46)
+                           {
+                              ch = *--ascii, ++size;
+                              /* Advance exp_b10 to '1', so that the
+                               * decimal point happens after the
+                               * previous digit.
+                               */
+                              exp_b10 = 1;
+                           }
+                           --cdigits;
+                           d = ch - 47;  /* I.e. 1+(ch-48) */
+                        }
+                        /* Did we reach the beginning? If so adjust the
+                         * exponent but take into account the leading
+                         * decimal point.
+                         */
+                        if (d > 9)  /* cdigits == 0 */
+                        {
+                           if (exp_b10 == (-1))
+                           {
+                              /* Leading decimal point (plus zeros?), if
+                               * we lose the decimal point here it must
+                               * be reentered below.
+                               */
+                              int ch = *--ascii;
+                              if (ch == 46)
+                                 ++size, exp_b10 = 1;
+                              /* Else lost a leading zero, so 'exp_b10' is
+                               * still ok at (-1)
+                               */
+                           }
+                           else
+                              ++exp_b10;
+                           /* In all cases we output a '1' */
+                           d = 1;
+                        }
+                     }
+                  }
+                  fp = 0; /* Guarantees termination below. */
+               }
+               if (d == 0)
+               {
+                  ++czero;
+                  if (cdigits == 0) ++clead;
+               }
+               else
+               {
+                  /* Included embedded zeros in the digit count. */
+                  cdigits += czero - clead;
+                  clead = 0;
+                  while (czero > 0)
+                  {
+                     /* exp_b10 == (-1) means we just output the decimal
+                      * place - after the DP don't adjust 'exp_b10' any
+                      * more!
+                      */
+                     if (exp_b10 != (-1))
+                     {
+                        if (exp_b10 == 0) *ascii++ = 46, --size;
+                        /* PLUS 1: TOTAL 4 */
+                        --exp_b10;
+                     }
+                     *ascii++ = 48, --czero;
+                  }
+                  if (exp_b10 != (-1))
+                  {
+                     if (exp_b10 == 0) *ascii++ = 46, --size; /* counted
+                                                                 above */
+                     --exp_b10;
+                  }
+                  *ascii++ = (char)(48 + (int)d), ++cdigits;
+               }
+            }
+            while (cdigits+czero-clead < (int)precision && fp > DBL_MIN);
+            /* The total output count (max) is now 4+precision */
+            /* Check for an exponent, if we don't need one we are
+             * done and just need to terminate the string.  At
+             * this point exp_b10==(-1) is effectively if flag - it got
+             * to '-1' because of the decrement after outputing
+             * the decimal point above (the exponent required is
+             * *not* -1!)
+             */
+            if (exp_b10 >= (-1) && exp_b10 <= 2)
+            {
+               /* The following only happens if we didn't output the
+                * leading zeros above for negative exponent, so this
+                * doest add to the digit requirement.  Note that the
+                * two zeros here can only be output if the two leading
+                * zeros were *not* output, so this doesn't increase
+                * the output count.
+                */
+               while (--exp_b10 >= 0) *ascii++ = 48;
+               *ascii = 0;
+               /* Total buffer requirement (including the '\0') is
+                * 5+precision - see check at the start.
+                */
+               return;
+            }
+            /* Here if an exponent is required, adjust size for
+             * the digits we output but did not count.  The total
+             * digit output here so far is at most 1+precision - no
+             * decimal point and no leading or trailing zeros have
+             * been output.
+             */
+            size -= cdigits;
+            *ascii++ = 69, --size;    /* 'E': PLUS 1 TOTAL 2+precision */
+            /* The following use of an unsigned temporary avoids ambiguities in
+             * the signed arithmetic on exp_b10 and permits GCC at least to do
+             * better optimization.
+             */
+            {
+               unsigned int uexp_b10;
+               if (exp_b10 < 0)
+               {
+                  *ascii++ = 45, --size; /* '-': PLUS 1 TOTAL 3+precision */
+                  uexp_b10 = -exp_b10;
+               }
+               else
+                  uexp_b10 = exp_b10;
+               cdigits = 0;
+               while (uexp_b10 > 0)
+               {
+                  exponent[cdigits++] = (char)(48 + uexp_b10 % 10);
+                  uexp_b10 /= 10;
+               }
+            }
+            /* Need another size check here for the exponent digits, so
+             * this need not be considered above.
+             */
+            if ((int)size > cdigits)
+            {
+               while (cdigits > 0) *ascii++ = exponent[--cdigits];
+               *ascii = 0;
+               return;
+            }
+         }
+      }
+      else if (!(fp >= DBL_MIN))
+      {
+         *ascii++ = 48; /* '0' */
+         *ascii = 0;
+         return;
+      }
+      else
+      {
+         *ascii++ = 105; /* 'i' */
+         *ascii++ = 110; /* 'n' */
+         *ascii++ = 102; /* 'f' */
+         *ascii = 0;
+         return;
+      }
+   }
+   /* Here on buffer too small. */
+   png_error(png_ptr, "ASCII conversion buffer too small");
+}
+#  endif /* FLOATING_POINT */
+#  ifdef PNG_FIXED_POINT_SUPPORTED
+/* Function to format a fixed point value in ASCII.
+ */
+void /* PRIVATE */
+png_ascii_from_fixed(png_structp png_ptr, png_charp ascii, png_size_t size,
+    png_fixed_point fp)
+{
+   /* Require space for 10 decimal digits, a decimal point, a minus sign and a
+    * trailing \0, 13 characters:
+    */
+   if (size > 12)
+   {
+      png_uint_32 num;
+      /* Avoid overflow here on the minimum integer. */
+      if (fp < 0)
+         *ascii++ = 45, --size, num = -fp;
+      else
+         num = fp;
+      if (num <= 0x80000000) /* else overflowed */
+      {
+         unsigned int ndigits = 0, first = 16 /* flag value */;
+         char digits[10];
+         while (num)
+         {
+            /* Split the low digit off num: */
+            unsigned int tmp = num/10;
+            num -= tmp*10;
+            digits[ndigits++] = (char)(48 + num);
+            /* Record the first non-zero digit, note that this is a number
+             * starting at 1, it's not actually the array index.
+             */
+            if (first == 16 && num > 0)
+               first = ndigits;
+            num = tmp;
+         }
+         if (ndigits > 0)
+         {
+            while (ndigits > 5) *ascii++ = digits[--ndigits];
+            /* The remaining digits are fractional digits, ndigits is '5' or
+             * smaller at this point.  It is certainly not zero.  Check for a
+             * non-zero fractional digit:
+             */
+            if (first <= 5)
+            {
+               unsigned int i;
+               *ascii++ = 46; /* decimal point */
+               /* ndigits may be <5 for small numbers, output leading zeros
+                * then ndigits digits to first:
+                */
+               i = 5;
+               while (ndigits < i) *ascii++ = 48, --i;
+               while (ndigits >= first) *ascii++ = digits[--ndigits];
+               /* Don't output the trailing zeros! */
+            }
+         }
+         else
+            *ascii++ = 48;
+         /* And null terminate the string: */
+         *ascii = 0;
+         return;
+      }
+   }
+   /* Here on buffer too small. */
+   png_error(png_ptr, "ASCII conversion buffer too small");
+}
+#   endif /* FIXED_POINT */
+#endif /* READ_SCAL */
+#if defined(PNG_FLOATING_POINT_SUPPORTED) && \
+   !defined(PNG_FIXED_POINT_MACRO_SUPPORTED)
+png_fixed_point
+png_fixed(png_structp png_ptr, double fp, png_const_charp text)
+{
+   double r = floor(100000 * fp + .5);
+   if (r > 2147483647. || r < -2147483648.)
+      png_fixed_error(png_ptr, text);
+   return (png_fixed_point)r;
+}
+#endif
+#if defined(PNG_READ_GAMMA_SUPPORTED) || \
+    defined(PNG_INCH_CONVERSIONS_SUPPORTED) || defined(PNG__READ_pHYs_SUPPORTED)
+/* muldiv functions */
+/* This API takes signed arguments and rounds the result to the nearest
+ * integer (or, for a fixed point number - the standard argument - to
+ * the nearest .00001).  Overflow and divide by zero are signalled in
+ * the result, a boolean - true on success, false on overflow.
+ */
+int
+png_muldiv(png_fixed_point_p res, png_fixed_point a, png_int_32 times,
+    png_int_32 divisor)
+{
+   /* Return a * times / divisor, rounded. */
+   if (divisor != 0)
+   {
+      if (a == 0 || times == 0)
+      {
+         *res = 0;
+         return 1;
+      }
+      else
+      {
+#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
+         double r = a;
+         r *= times;
+         r /= divisor;
+         r = floor(r+.5);
+         /* A png_fixed_point is a 32-bit integer. */
+         if (r <= 2147483647. && r >= -2147483648.)
+         {
+            *res = (png_fixed_point)r;
+            return 1;
+         }
+#else
+         int negative = 0;
+         png_uint_32 A, T, D;
+         png_uint_32 s16, s32, s00;
+         if (a < 0)
+            negative = 1, A = -a;
+         else
+            A = a;
+         if (times < 0)
+            negative = !negative, T = -times;
+         else
+            T = times;
+         if (divisor < 0)
+            negative = !negative, D = -divisor;
+         else
+            D = divisor;
+         /* Following can't overflow because the arguments only
+          * have 31 bits each, however the result may be 32 bits.
+          */
+         s16 = (A >> 16) * (T & 0xffff) +
+                           (A & 0xffff) * (T >> 16);
+         /* Can't overflow because the a*times bit is only 30
+          * bits at most.
+          */
+         s32 = (A >> 16) * (T >> 16) + (s16 >> 16);
+         s00 = (A & 0xffff) * (T & 0xffff);
+         s16 = (s16 & 0xffff) << 16;
+         s00 += s16;
+         if (s00 < s16)
+            ++s32; /* carry */
+         if (s32 < D) /* else overflow */
+         {
+            /* s32.s00 is now the 64-bit product, do a standard
+             * division, we know that s32 < D, so the maximum
+             * required shift is 31.
+             */
+            int bitshift = 32;
+            png_fixed_point result = 0; /* NOTE: signed */
+            while (--bitshift >= 0)
+            {
+               png_uint_32 d32, d00;
+               if (bitshift > 0)
+                  d32 = D >> (32-bitshift), d00 = D << bitshift;
+               else
+                  d32 = 0, d00 = D;
+               if (s32 > d32)
+               {
+                  if (s00 < d00) --s32; /* carry */
+                  s32 -= d32, s00 -= d00, result += 1<<bitshift;
+               }
+               else
+                  if (s32 == d32 && s00 >= d00)
+                     s32 = 0, s00 -= d00, result += 1<<bitshift;
+            }
+            /* Handle the rounding. */
+            if (s00 >= (D >> 1))
+               ++result;
+            if (negative)
+               result = -result;
+            /* Check for overflow. */
+            if ((negative && result <= 0) || (!negative && result >= 0))
+            {
+               *res = result;
+               return 1;
+            }
+         }
+#endif
+      }
+   }
+   return 0;
+}
+#endif /* READ_GAMMA || INCH_CONVERSIONS */
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_INCH_CONVERSIONS_SUPPORTED)
+/* The following is for when the caller doesn't much care about the
+ * result.
+ */
+png_fixed_point
+png_muldiv_warn(png_structp png_ptr, png_fixed_point a, png_int_32 times,
+    png_int_32 divisor)
+{
+   png_fixed_point result;
+   if (png_muldiv(&result, a, times, divisor))
+      return result;
+   png_warning(png_ptr, "fixed point overflow ignored");
+   return 0;
+}
+#endif
+#ifdef PNG_READ_GAMMA_SUPPORTED /* more fixed point functions for gammma */
+/* Calculate a reciprocal, return 0 on div-by-zero or overflow. */
+png_fixed_point
+png_reciprocal(png_fixed_point a)
+{
+#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
+   double r = floor(1E10/a+.5);
+   if (r <= 2147483647. && r >= -2147483648.)
+      return (png_fixed_point)r;
+#else
+   png_fixed_point res;
+   if (png_muldiv(&res, 100000, 100000, a))
+      return res;
+#endif
+   return 0; /* error/overflow */
+}
+/* A local convenience routine. */
+static png_fixed_point
+png_product2(png_fixed_point a, png_fixed_point b)
+{
+   /* The required result is 1/a * 1/b; the following preserves accuracy. */
+#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
+   double r = a * 1E-5;
+   r *= b;
+   r = floor(r+.5);
+   if (r <= 2147483647. && r >= -2147483648.)
+      return (png_fixed_point)r;
+#else
+   png_fixed_point res;
+   if (png_muldiv(&res, a, b, 100000))
+      return res;
+#endif
+   return 0; /* overflow */
+}
+/* The inverse of the above. */
+png_fixed_point
+png_reciprocal2(png_fixed_point a, png_fixed_point b)
+{
+   /* The required result is 1/a * 1/b; the following preserves accuracy. */
+#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
+   double r = 1E15/a;
+   r /= b;
+   r = floor(r+.5);
+   if (r <= 2147483647. && r >= -2147483648.)
+      return (png_fixed_point)r;
+#else
+   /* This may overflow because the range of png_fixed_point isn't symmetric,
+    * but this API is only used for the product of file and screen gamma so it
+    * doesn't matter that the smallest number it can produce is 1/21474, not
+    * 1/100000
+    */
+   png_fixed_point res = png_product2(a, b);
+   if (res != 0)
+      return png_reciprocal(res);
+#endif
+   return 0; /* overflow */
+}
+#endif /* READ_GAMMA */
+#ifdef PNG_CHECK_cHRM_SUPPORTED
+/* Added at libpng version 1.2.34 (Dec 8, 2008) and 1.4.0 (Jan 2,
+ * 2010: moved from pngset.c) */
+/*
+ *    Multiply two 32-bit numbers, V1 and V2, using 32-bit
+ *    arithmetic, to produce a 64-bit result in the HI/LO words.
+ *
+ *                  A B
+ *                x C D
+ *               ------
+ *              AD || BD
+ *        AC || CB || 0
+ *
+ *    where A and B are the high and low 16-bit words of V1,
+ *    C and D are the 16-bit words of V2, AD is the product of
+ *    A and D, and X || Y is (X << 16) + Y.
+*/
+void /* PRIVATE */
+png_64bit_product (long v1, long v2, unsigned long *hi_product,
+    unsigned long *lo_product)
+{
+   int a, b, c, d;
+   long lo, hi, x, y;
+   a = (v1 >> 16) & 0xffff;
+   b = v1 & 0xffff;
+   c = (v2 >> 16) & 0xffff;
+   d = v2 & 0xffff;
+   lo = b * d;                   /* BD */
+   x = a * d + c * b;            /* AD + CB */
+   y = ((lo >> 16) & 0xffff) + x;
+   lo = (lo & 0xffff) | ((y & 0xffff) << 16);
+   hi = (y >> 16) & 0xffff;
+   hi += a * c;                  /* AC */
+   *hi_product = (unsigned long)hi;
+   *lo_product = (unsigned long)lo;
+}
+#endif /* CHECK_cHRM */
+#ifdef PNG_READ_GAMMA_SUPPORTED /* gamma table code */
+#ifndef PNG_FLOATING_ARITHMETIC_SUPPORTED
+/* Fixed point gamma.
+ *
+ * To calculate gamma this code implements fast log() and exp() calls using only
+ * fixed point arithmetic.  This code has sufficient precision for either 8-bit
+ * or 16-bit sample values.
+ *
+ * The tables used here were calculated using simple 'bc' programs, but C double
+ * precision floating point arithmetic would work fine.  The programs are given
+ * at the head of each table.
+ *
+ * 8-bit log table
+ *   This is a table of -log(value/255)/log(2) for 'value' in the range 128 to
+ *   255, so it's the base 2 logarithm of a normalized 8-bit floating point
+ *   mantissa.  The numbers are 32-bit fractions.
+ */
+static png_uint_32
+png_8bit_l2[128] =
+{
+#  ifdef PNG_DO_BC
+      for (i=128;i<256;++i) { .5 - l(i/255)/l(2)*65536*65536; }
+#  else
+   4270715492U, 4222494797U, 4174646467U, 4127164793U, 4080044201U, 4033279239U,
+   3986864580U, 3940795015U, 3895065449U, 3849670902U, 3804606499U, 3759867474U,
+   3715449162U, 3671346997U, 3627556511U, 3584073329U, 3540893168U, 3498011834U,
+   3455425220U, 3413129301U, 3371120137U, 3329393864U, 3287946700U, 3246774933U,
+   3205874930U, 3165243125U, 3124876025U, 3084770202U, 3044922296U, 3005329011U,
+   2965987113U, 2926893432U, 2888044853U, 2849438323U, 2811070844U, 2772939474U,
+   2735041326U, 2697373562U, 2659933400U, 2622718104U, 2585724991U, 2548951424U,
+   2512394810U, 2476052606U, 2439922311U, 2404001468U, 2368287663U, 2332778523U,
+   2297471715U, 2262364947U, 2227455964U, 2192742551U, 2158222529U, 2123893754U,
+   2089754119U, 2055801552U, 2022034013U, 1988449497U, 1955046031U, 1921821672U,
+   1888774511U, 1855902668U, 1823204291U, 1790677560U, 1758320682U, 1726131893U,
+   1694109454U, 1662251657U, 1630556815U, 1599023271U, 1567649391U, 1536433567U,
+   1505374214U, 1474469770U, 1443718700U, 1413119487U, 1382670639U, 1352370686U,
+   1322218179U, 1292211689U, 1262349810U, 1232631153U, 1203054352U, 1173618059U,
+   1144320946U, 1115161701U, 1086139034U, 1057251672U, 1028498358U, 999877854U,
+   971388940U, 943030410U, 914801076U, 886699767U, 858725327U, 830876614U,
+   803152505U, 775551890U, 748073672U, 720716771U, 693480120U, 666362667U,
+   639363374U, 612481215U, 585715177U, 559064263U, 532527486U, 506103872U,
+   479792461U, 453592303U, 427502463U, 401522014U, 375650043U, 349885648U,
+   324227938U, 298676034U, 273229066U, 247886176U, 222646516U, 197509248U,
+   172473545U, 147538590U, 122703574U, 97967701U, 73330182U, 48790236U,
+   24347096U, 0U
+#  endif
+#if 0
+   /* The following are the values for 16-bit tables - these work fine for the
+    * 8-bit conversions but produce very slightly larger errors in the 16-bit
+    * log (about 1.2 as opposed to 0.7 absolute error in the final value).  To
+    * use these all the shifts below must be adjusted appropriately.
+    */
+   65166, 64430, 63700, 62976, 62257, 61543, 60835, 60132, 59434, 58741, 58054,
+   57371, 56693, 56020, 55352, 54689, 54030, 53375, 52726, 52080, 51439, 50803,
+   50170, 49542, 48918, 48298, 47682, 47070, 46462, 45858, 45257, 44661, 44068,
+   43479, 42894, 42312, 41733, 41159, 40587, 40020, 39455, 38894, 38336, 37782,
+   37230, 36682, 36137, 35595, 35057, 34521, 33988, 33459, 32932, 32408, 31887,
+   31369, 30854, 30341, 29832, 29325, 28820, 28319, 27820, 27324, 26830, 26339,
+   25850, 25364, 24880, 24399, 23920, 23444, 22970, 22499, 22029, 21562, 21098,
+   20636, 20175, 19718, 19262, 18808, 18357, 17908, 17461, 17016, 16573, 16132,
+   15694, 15257, 14822, 14390, 13959, 13530, 13103, 12678, 12255, 11834, 11415,
+   10997, 10582, 10168, 9756, 9346, 8937, 8531, 8126, 7723, 7321, 6921, 6523,
+   6127, 5732, 5339, 4947, 4557, 4169, 3782, 3397, 3014, 2632, 2251, 1872, 1495,
+   1119, 744, 372
+#endif
+};
+PNG_STATIC png_int_32
+png_log8bit(unsigned int x)
+{
+   unsigned int lg2 = 0;
+   /* Each time 'x' is multiplied by 2, 1 must be subtracted off the final log,
+    * because the log is actually negate that means adding 1.  The final
+    * returned value thus has the range 0 (for 255 input) to 7.994 (for 1
+    * input), return 7.99998 for the overflow (log 0) case - so the result is
+    * always at most 19 bits.
+    */
+   if ((x &= 0xff) == 0)
+      return 0xffffffff;
+   if ((x & 0xf0) == 0)
+      lg2  = 4, x <<= 4;
+   if ((x & 0xc0) == 0)
+      lg2 += 2, x <<= 2;
+   if ((x & 0x80) == 0)
+      lg2 += 1, x <<= 1;
+   /* result is at most 19 bits, so this cast is safe: */
+   return (png_int_32)((lg2 << 16) + ((png_8bit_l2[x-128]+32768)>>16));
+}
+/* The above gives exact (to 16 binary places) log2 values for 8-bit images,
+ * for 16-bit images we use the most significant 8 bits of the 16-bit value to
+ * get an approximation then multiply the approximation by a correction factor
+ * determined by the remaining up to 8 bits.  This requires an additional step
+ * in the 16-bit case.
+ *
+ * We want log2(value/65535), we have log2(v'/255), where:
+ *
+ *    value = v' * 256 + v''
+ *          = v' * f
+ *
+ * So f is value/v', which is equal to (256+v''/v') since v' is in the range 128
+ * to 255 and v'' is in the range 0 to 255 f will be in the range 256 to less
+ * than 258.  The final factor also needs to correct for the fact that our 8-bit
+ * value is scaled by 255, whereas the 16-bit values must be scaled by 65535.
+ *
+ * This gives a final formula using a calculated value 'x' which is value/v' and
+ * scaling by 65536 to match the above table:
+ *
+ *   log2(x/257) * 65536
+ *
+ * Since these numbers are so close to '1' we can use simple linear
+ * interpolation between the two end values 256/257 (result -368.61) and 258/257
+ * (result 367.179).  The values used below are scaled by a further 64 to give
+ * 16-bit precision in the interpolation:
+ *
+ * Start (256): -23591
+ * Zero  (257):      0
+ * End   (258):  23499
+ */
+PNG_STATIC png_int_32
+png_log16bit(png_uint_32 x)
+{
+   unsigned int lg2 = 0;
+   /* As above, but now the input has 16 bits. */
+   if ((x &= 0xffff) == 0)
+      return 0xffffffff;
+   if ((x & 0xff00) == 0)
+      lg2  = 8, x <<= 8;
+   if ((x & 0xf000) == 0)
+      lg2 += 4, x <<= 4;
+   if ((x & 0xc000) == 0)
+      lg2 += 2, x <<= 2;
+   if ((x & 0x8000) == 0)
+      lg2 += 1, x <<= 1;
+   /* Calculate the base logarithm from the top 8 bits as a 28-bit fractional
+    * value.
+    */
+   lg2 <<= 28;
+   lg2 += (png_8bit_l2[(x>>8)-128]+8) >> 4;
+   /* Now we need to interpolate the factor, this requires a division by the top
+    * 8 bits.  Do this with maximum precision.
+    */
+   x = ((x << 16) + (x >> 9)) / (x >> 8);
+   /* Since we divided by the top 8 bits of 'x' there will be a '1' at 1<<24,
+    * the value at 1<<16 (ignoring this) will be 0 or 1; this gives us exactly
+    * 16 bits to interpolate to get the low bits of the result.  Round the
+    * answer.  Note that the end point values are scaled by 64 to retain overall
+    * precision and that 'lg2' is current scaled by an extra 12 bits, so adjust
+    * the overall scaling by 6-12.  Round at every step.
+    */
+   x -= 1U << 24;
+   if (x <= 65536U) /* <= '257' */
+      lg2 += ((23591U * (65536U-x)) + (1U << (16+6-12-1))) >> (16+6-12);
+   else
+      lg2 -= ((23499U * (x-65536U)) + (1U << (16+6-12-1))) >> (16+6-12);
+   /* Safe, because the result can't have more than 20 bits: */
+   return (png_int_32)((lg2 + 2048) >> 12);
+}
+/* The 'exp()' case must invert the above, taking a 20-bit fixed point
+ * logarithmic value and returning a 16 or 8-bit number as appropriate.  In
+ * each case only the low 16 bits are relevant - the fraction - since the
+ * integer bits (the top 4) simply determine a shift.
+ *
+ * The worst case is the 16-bit distinction between 65535 and 65534, this
+ * requires perhaps spurious accuracy in the decoding of the logarithm to
+ * distinguish log2(65535/65534.5) - 10^-5 or 17 bits.  There is little chance
+ * of getting this accuracy in practice.
+ *
+ * To deal with this the following exp() function works out the exponent of the
+ * frational part of the logarithm by using an accurate 32-bit value from the
+ * top four fractional bits then multiplying in the remaining bits.
+ */
+static png_uint_32
+png_32bit_exp[16] =
+{
+#  ifdef PNG_DO_BC
+      for (i=0;i<16;++i) { .5 + e(-i/16*l(2))*2^32; }
+#  else
+   /* NOTE: the first entry is deliberately set to the maximum 32-bit value. */
+   4294967295U, 4112874773U, 3938502376U, 3771522796U, 3611622603U, 3458501653U,
+   3311872529U, 3171459999U, 3037000500U, 2908241642U, 2784941738U, 2666869345U,
+   2553802834U, 2445529972U, 2341847524U, 2242560872U
+#  endif
+};
+/* Adjustment table; provided to explain the numbers in the code below. */
+#ifdef PNG_DO_BC
+for (i=11;i>=0;--i){ print i, " ", (1 - e(-(2^i)/65536*l(2))) * 2^(32-i), "\n"}
+   11 44937.64284865548751208448
+   10 45180.98734845585101160448
+    9 45303.31936980687359311872
+    8 45364.65110595323018870784
+    7 45395.35850361789624614912
+    6 45410.72259715102037508096
+    5 45418.40724413220722311168
+    4 45422.25021786898173001728
+    3 45424.17186732298419044352
+    2 45425.13273269940811464704
+    1 45425.61317555035558641664
+    0 45425.85339951654943850496
+#endif
+PNG_STATIC png_uint_32
+png_exp(png_fixed_point x)
+{
+   if (x > 0 && x <= 0xfffff) /* Else overflow or zero (underflow) */
+   {
+      /* Obtain a 4-bit approximation */
+      png_uint_32 e = png_32bit_exp[(x >> 12) & 0xf];
+      /* Incorporate the low 12 bits - these decrease the returned value by
+       * multiplying by a number less than 1 if the bit is set.  The multiplier
+       * is determined by the above table and the shift. Notice that the values
+       * converge on 45426 and this is used to allow linear interpolation of the
+       * low bits.
+       */
+      if (x & 0x800)
+         e -= (((e >> 16) * 44938U) +  16U) >> 5;
+      if (x & 0x400)
+         e -= (((e >> 16) * 45181U) +  32U) >> 6;
+      if (x & 0x200)
+         e -= (((e >> 16) * 45303U) +  64U) >> 7;
+      if (x & 0x100)
+         e -= (((e >> 16) * 45365U) + 128U) >> 8;
+      if (x & 0x080)
+         e -= (((e >> 16) * 45395U) + 256U) >> 9;
+      if (x & 0x040)
+         e -= (((e >> 16) * 45410U) + 512U) >> 10;
+      /* And handle the low 6 bits in a single block. */
+      e -= (((e >> 16) * 355U * (x & 0x3fU)) + 256U) >> 9;
+      /* Handle the upper bits of x. */
+      e >>= x >> 16;
+      return e;
+   }
+   /* Check for overflow */
+   if (x <= 0)
+      return png_32bit_exp[0];
+   /* Else underflow */
+   return 0;
+}
+PNG_STATIC png_byte
+png_exp8bit(png_fixed_point lg2)
+{
+   /* Get a 32-bit value: */
+   png_uint_32 x = png_exp(lg2);
+   /* Convert the 32-bit value to 0..255 by multiplying by 256-1, note that the
+    * second, rounding, step can't overflow because of the first, subtraction,
+    * step.
+    */
+   x -= x >> 8;
+   return (png_byte)((x + 0x7fffffU) >> 24);
+}
+PNG_STATIC png_uint_16
+png_exp16bit(png_fixed_point lg2)
+{
+   /* Get a 32-bit value: */
+   png_uint_32 x = png_exp(lg2);
+   /* Convert the 32-bit value to 0..65535 by multiplying by 65536-1: */
+   x -= x >> 16;
+   return (png_uint_16)((x + 32767U) >> 16);
+}
+#endif /* FLOATING_ARITHMETIC */
+png_byte
+png_gamma_8bit_correct(unsigned int value, png_fixed_point gamma_val)
+{
+   if (value > 0 && value < 255)
+   {
+#     ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
+         double r = floor(255*pow(value/255.,gamma_val*.00001)+.5);
+         return (png_byte)r;
+#     else
+         png_int_32 lg2 = png_log8bit(value);
+         png_fixed_point res;
+         if (png_muldiv(&res, gamma_val, lg2, PNG_FP_1))
+            return png_exp8bit(res);
+         /* Overflow. */
+         value = 0;
+#     endif
+   }
+   return (png_byte)value;
+}
+png_uint_16
+png_gamma_16bit_correct(unsigned int value, png_fixed_point gamma_val)
+{
+   if (value > 0 && value < 65535)
+   {
+#     ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
+         double r = floor(65535*pow(value/65535.,gamma_val*.00001)+.5);
+         return (png_uint_16)r;
+#     else
+         png_int_32 lg2 = png_log16bit(value);
+         png_fixed_point res;
+         if (png_muldiv(&res, gamma_val, lg2, PNG_FP_1))
+            return png_exp16bit(res);
+         /* Overflow. */
+         value = 0;
+#     endif
+   }
+   return (png_uint_16)value;
+}
+/* This does the right thing based on the bit_depth field of the
+ * png_struct, interpreting values as 8-bit or 16-bit.  While the result
+ * is nominally a 16-bit value if bit depth is 8 then the result is
+ * 8-bit (as are the arguments.)
+ */
+png_uint_16 /* PRIVATE */
+png_gamma_correct(png_structp png_ptr, unsigned int value,
+    png_fixed_point gamma_val)
+{
+   if (png_ptr->bit_depth == 8)
+      return png_gamma_8bit_correct(value, gamma_val);
+   else
+      return png_gamma_16bit_correct(value, gamma_val);
+}
+/* This is the shared test on whether a gamma value is 'significant' - whether
+ * it is worth doing gamma correction.
+ */
+int /* PRIVATE */
+png_gamma_significant(png_fixed_point gamma_val)
+{
+   return gamma_val < PNG_FP_1 - PNG_GAMMA_THRESHOLD_FIXED ||
+       gamma_val > PNG_FP_1 + PNG_GAMMA_THRESHOLD_FIXED;
+}
+/* Internal function to build a single 16-bit table - the table consists of
+ * 'num' 256-entry subtables, where 'num' is determined by 'shift' - the amount
+ * to shift the input values right (or 16-number_of_signifiant_bits).
+ *
+ * The caller is responsible for ensuring that the table gets cleaned up on
+ * png_error (i.e. if one of the mallocs below fails) - i.e. the *table argument
+ * should be somewhere that will be cleaned.
+ */
+static void
+png_build_16bit_table(png_structp png_ptr, png_uint_16pp *ptable,
+   PNG_CONST unsigned int shift, PNG_CONST png_fixed_point gamma_val)
+{
+   /* Various values derived from 'shift': */
+   PNG_CONST unsigned int num = 1U << (8U - shift);
+   PNG_CONST unsigned int max = (1U << (16U - shift))-1U;
+   PNG_CONST unsigned int max_by_2 = 1U << (15U-shift);
+   unsigned int i;
+   png_uint_16pp table = *ptable =
+       (png_uint_16pp)png_calloc(png_ptr, num * png_sizeof(png_uint_16p));
+   for (i = 0; i < num; i++)
+   {
+      png_uint_16p sub_table = table[i] =
+          (png_uint_16p)png_malloc(png_ptr, 256 * png_sizeof(png_uint_16));
+      /* The 'threshold' test is repeated here because it can arise for one of
+       * the 16-bit tables even if the others don't hit it.
+       */
+      if (png_gamma_significant(gamma_val))
+      {
+         /* The old code would overflow at the end and this would cause the
+          * 'pow' function to return a result >1, resulting in an
+          * arithmetic error.  This code follows the spec exactly; ig is
+          * the recovered input sample, it always has 8-16 bits.
+          *
+          * We want input * 65535/max, rounded, the arithmetic fits in 32
+          * bits (unsigned) so long as max <= 32767.
+          */
+         unsigned int j;
+         for (j = 0; j < 256; j++)
+         {
+            png_uint_32 ig = (j << (8-shift)) + i;
+#           ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
+               /* Inline the 'max' scaling operation: */
+               double d = floor(65535*pow(ig/(double)max, gamma_val*.00001)+.5);
+               sub_table[j] = (png_uint_16)d;
+#           else
+               if (shift)
+                  ig = (ig * 65535U + max_by_2)/max;
+               sub_table[j] = png_gamma_16bit_correct(ig, gamma_val);
+#           endif
+         }
+      }
+      else
+      {
+         /* We must still build a table, but do it the fast way. */
+         unsigned int j;
+         for (j = 0; j < 256; j++)
+         {
+            png_uint_32 ig = (j << (8-shift)) + i;
+            if (shift)
+               ig = (ig * 65535U + max_by_2)/max;
+            sub_table[j] = (png_uint_16)ig;
+         }
+      }
+   }
+}
+/* NOTE: this function expects the *inverse* of the overall gamma transformation
+ * required.
+ */
+static void
+png_build_16to8_table(png_structp png_ptr, png_uint_16pp *ptable,
+   PNG_CONST unsigned int shift, PNG_CONST png_fixed_point gamma_val)
+{
+   PNG_CONST unsigned int num = 1U << (8U - shift);
+   PNG_CONST unsigned int max = (1U << (16U - shift))-1U;
+   unsigned int i;
+   png_uint_32 last;
+   png_uint_16pp table = *ptable =
+       (png_uint_16pp)png_calloc(png_ptr, num * png_sizeof(png_uint_16p));
+   /* 'num' is the number of tables and also the number of low bits of the
+    * input 16-bit value used to select a table.  Each table is itself indexed
+    * by the high 8 bits of the value.
+    */
+   for (i = 0; i < num; i++)
+      table[i] = (png_uint_16p)png_malloc(png_ptr,
+          256 * png_sizeof(png_uint_16));
+   /* 'gamma_val' is set to the reciprocal of the value calculated above, so
+    * pow(out,g) is an *input* value.  'last' is the last input value set.
+    *
+    * In the loop 'i' is used to find output values.  Since the output is
+    * 8-bit there are only 256 possible values.  The tables are set up to
+    * select the closest possible output value for each input by finding
+    * the input value at the boundary between each pair of output values
+    * and filling the table up to that boundary with the lower output
+    * value.
+    *
+    * The boundary values are 0.5,1.5..253.5,254.5.  Since these are 9-bit
+    * values the code below uses a 16-bit value in i; the values start at
+    * 128.5 (for 0.5) and step by 257, for a total of 254 values (the last
+    * entries are filled with 255).  Start i at 128 and fill all 'last'
+    * table entries <= 'max'
+    */
+   last = 0;
+   for (i = 0; i < 255; ++i) /* 8-bit output value */
+   {
+      /* Find the corresponding maximum input value */
+      png_uint_16 out = (png_uint_16)(i * 257U); /* 16-bit output value */
+      /* Find the boundary value in 16 bits: */
+      png_uint_32 bound = png_gamma_16bit_correct(out+128U, gamma_val);
+      /* Adjust (round) to (16-shift) bits: */
+      bound = (bound * max + 32768U)/65535U + 1U;
+      while (last < bound)
+      {
+         table[last & (0xffU >> shift)][last >> (8U - shift)] = out;
+         last++;
+      }
+   }
+   /* And fill in the final entries. */
+   while (last < (num << 8))
+   {
+      table[last & (0xff >> shift)][last >> (8U - shift)] = 65535U;
+      last++;
+   }
+}
+/* Build a single 8-bit table: same as the 16-bit case but much simpler (and
+ * typically much faster).  Note that libpng currently does no sBIT processing
+ * (apparently contrary to the spec) so a 256-entry table is always generated.
+ */
+static void
+png_build_8bit_table(png_structp png_ptr, png_bytepp ptable,
+   PNG_CONST png_fixed_point gamma_val)
+{
+   unsigned int i;
+   png_bytep table = *ptable = (png_bytep)png_malloc(png_ptr, 256);
+   if (png_gamma_significant(gamma_val)) for (i=0; i<256; i++)
+      table[i] = png_gamma_8bit_correct(i, gamma_val);
+   else for (i=0; i<256; ++i)
+      table[i] = (png_byte)i;
+}
+/* Used from png_read_destroy and below to release the memory used by the gamma
+ * tables.
+ */
+void /* PRIVATE */
+png_destroy_gamma_table(png_structp png_ptr)
+{
+   png_free(png_ptr, png_ptr->gamma_table);
+   png_ptr->gamma_table = NULL;
+   if (png_ptr->gamma_16_table != NULL)
+   {
+      int i;
+      int istop = (1 << (8 - png_ptr->gamma_shift));
+      for (i = 0; i < istop; i++)
+      {
+         png_free(png_ptr, png_ptr->gamma_16_table[i]);
+      }
+   png_free(png_ptr, png_ptr->gamma_16_table);
+   png_ptr->gamma_16_table = NULL;
+   }
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
+   defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \
+   defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+   png_free(png_ptr, png_ptr->gamma_from_1);
+   png_ptr->gamma_from_1 = NULL;
+   png_free(png_ptr, png_ptr->gamma_to_1);
+   png_ptr->gamma_to_1 = NULL;
+   if (png_ptr->gamma_16_from_1 != NULL)
+   {
+      int i;
+      int istop = (1 << (8 - png_ptr->gamma_shift));
+      for (i = 0; i < istop; i++)
+      {
+         png_free(png_ptr, png_ptr->gamma_16_from_1[i]);
+      }
+   png_free(png_ptr, png_ptr->gamma_16_from_1);
+   png_ptr->gamma_16_from_1 = NULL;
+   }
+   if (png_ptr->gamma_16_to_1 != NULL)
+   {
+      int i;
+      int istop = (1 << (8 - png_ptr->gamma_shift));
+      for (i = 0; i < istop; i++)
+      {
+         png_free(png_ptr, png_ptr->gamma_16_to_1[i]);
+      }
+   png_free(png_ptr, png_ptr->gamma_16_to_1);
+   png_ptr->gamma_16_to_1 = NULL;
+   }
+#endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */
+}
+/* We build the 8- or 16-bit gamma tables here.  Note that for 16-bit
+ * tables, we don't make a full table if we are reducing to 8-bit in
+ * the future.  Note also how the gamma_16 tables are segmented so that
+ * we don't need to allocate > 64K chunks for a full 16-bit table.
+ */
+void /* PRIVATE */
+png_build_gamma_table(png_structp png_ptr, int bit_depth)
+{
+  png_debug(1, "in png_build_gamma_table");
+  /* Remove any existing table; this copes with multiple calls to
+   * png_read_update_info.  The warning is because building the gamma tables
+   * multiple times is a performance hit - it's harmless but the ability to call
+   * png_read_update_info() multiple times is new in 1.5.6 so it seems sensible
+   * to warn if the app introduces such a hit.
+   */
+  if (png_ptr->gamma_table != NULL || png_ptr->gamma_16_table != NULL)
+  {
+    png_warning(png_ptr, "gamma table being rebuilt");
+    png_destroy_gamma_table(png_ptr);
+  }
+  if (bit_depth <= 8)
+  {
+     png_build_8bit_table(png_ptr, &png_ptr->gamma_table,
+         png_ptr->screen_gamma > 0 ?  png_reciprocal2(png_ptr->gamma,
+         png_ptr->screen_gamma) : PNG_FP_1);
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
+   defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \
+   defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+     if (png_ptr->transformations & (PNG_COMPOSE | PNG_RGB_TO_GRAY))
+     {
+        png_build_8bit_table(png_ptr, &png_ptr->gamma_to_1,
+            png_reciprocal(png_ptr->gamma));
+        png_build_8bit_table(png_ptr, &png_ptr->gamma_from_1,
+            png_ptr->screen_gamma > 0 ?  png_reciprocal(png_ptr->screen_gamma) :
+            png_ptr->gamma/* Probably doing rgb_to_gray */);
+     }
+#endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */
+  }
+  else
+  {
+     png_byte shift, sig_bit;
+     if (png_ptr->color_type & PNG_COLOR_MASK_COLOR)
+     {
+        sig_bit = png_ptr->sig_bit.red;
+        if (png_ptr->sig_bit.green > sig_bit)
+           sig_bit = png_ptr->sig_bit.green;
+        if (png_ptr->sig_bit.blue > sig_bit)
+           sig_bit = png_ptr->sig_bit.blue;
+     }
+     else
+        sig_bit = png_ptr->sig_bit.gray;
+     /* 16-bit gamma code uses this equation:
+      *
+      *   ov = table[(iv & 0xff) >> gamma_shift][iv >> 8]
+      *
+      * Where 'iv' is the input color value and 'ov' is the output value -
+      * pow(iv, gamma).
+      *
+      * Thus the gamma table consists of up to 256 256-entry tables.  The table
+      * is selected by the (8-gamma_shift) most significant of the low 8 bits of
+      * the color value then indexed by the upper 8 bits:
+      *
+      *   table[low bits][high 8 bits]
+      *
+      * So the table 'n' corresponds to all those 'iv' of:
+      *
+      *   <all high 8-bit values><n << gamma_shift>..<(n+1 << gamma_shift)-1>
+      *
+      */
+     if (sig_bit > 0 && sig_bit < 16U)
+        shift = (png_byte)(16U - sig_bit); /* shift == insignificant bits */
+     else
+        shift = 0; /* keep all 16 bits */
+     if (png_ptr->transformations & (PNG_16_TO_8 | PNG_SCALE_16_TO_8))
+     {
+        /* PNG_MAX_GAMMA_8 is the number of bits to keep - effectively
+         * the significant bits in the *input* when the output will
+         * eventually be 8 bits.  By default it is 11.
+         */
+        if (shift < (16U - PNG_MAX_GAMMA_8))
+           shift = (16U - PNG_MAX_GAMMA_8);
+     }
+     if (shift > 8U)
+        shift = 8U; /* Guarantees at least one table! */
+     png_ptr->gamma_shift = shift;
+#ifdef PNG_16BIT_SUPPORTED
+     /* NOTE: prior to 1.5.4 this test used to include PNG_BACKGROUND (now
+      * PNG_COMPOSE).  This effectively smashed the background calculation for
+      * 16-bit output because the 8-bit table assumes the result will be reduced
+      * to 8 bits.
+      */
+     if (png_ptr->transformations & (PNG_16_TO_8 | PNG_SCALE_16_TO_8))
+#endif
+         png_build_16to8_table(png_ptr, &png_ptr->gamma_16_table, shift,
+         png_ptr->screen_gamma > 0 ? png_product2(png_ptr->gamma,
+         png_ptr->screen_gamma) : PNG_FP_1);
+#ifdef PNG_16BIT_SUPPORTED
+     else
+         png_build_16bit_table(png_ptr, &png_ptr->gamma_16_table, shift,
+         png_ptr->screen_gamma > 0 ? png_reciprocal2(png_ptr->gamma,
+         png_ptr->screen_gamma) : PNG_FP_1);
+#endif
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
+   defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \
+   defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+     if (png_ptr->transformations & (PNG_COMPOSE | PNG_RGB_TO_GRAY))
+     {
+        png_build_16bit_table(png_ptr, &png_ptr->gamma_16_to_1, shift,
+            png_reciprocal(png_ptr->gamma));
+        /* Notice that the '16 from 1' table should be full precision, however
+         * the lookup on this table still uses gamma_shift, so it can't be.
+         * TODO: fix this.
+         */
+        png_build_16bit_table(png_ptr, &png_ptr->gamma_16_from_1, shift,
+            png_ptr->screen_gamma > 0 ? png_reciprocal(png_ptr->screen_gamma) :
+            png_ptr->gamma/* Probably doing rgb_to_gray */);
+     }
+#endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */
+  }
+}
+#endif /* READ_GAMMA */
+#endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/png.h b/libraries/irrlicht-1.8/source/Irrlicht/libpng/png.h
new file mode 100644
index 0000000..8126767
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/png.h
@@ -0,0 +1,2658 @@
+/* png.h - header file for PNG reference library
+ *
+ * libpng version 1.5.9 - February 18, 2012
+ * Copyright (c) 1998-2012 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license (See LICENSE, below)
+ *
+ * Authors and maintainers:
+ *   libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
+ *   libpng versions 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger
+ *   libpng versions 0.97, January 1998, through 1.5.9 - February 18, 2012: Glenn
+ *   See also "Contributing Authors", below.
+ *
+ * Note about libpng version numbers:
+ *
+ *   Due to various miscommunications, unforeseen code incompatibilities
+ *   and occasional factors outside the authors' control, version numbering
+ *   on the library has not always been consistent and straightforward.
+ *   The following table summarizes matters since version 0.89c, which was
+ *   the first widely used release:
+ *
+ *    source                 png.h  png.h  shared-lib
+ *    version                string   int  version
+ *    -------                ------ -----  ----------
+ *    0.89c "1.0 beta 3"     0.89      89  1.0.89
+ *    0.90  "1.0 beta 4"     0.90      90  0.90  [should have been 2.0.90]
+ *    0.95  "1.0 beta 5"     0.95      95  0.95  [should have been 2.0.95]
+ *    0.96  "1.0 beta 6"     0.96      96  0.96  [should have been 2.0.96]
+ *    0.97b "1.00.97 beta 7" 1.00.97   97  1.0.1 [should have been 2.0.97]
+ *    0.97c                  0.97      97  2.0.97
+ *    0.98                   0.98      98  2.0.98
+ *    0.99                   0.99      98  2.0.99
+ *    0.99a-m                0.99      99  2.0.99
+ *    1.00                   1.00     100  2.1.0 [100 should be 10000]
+ *    1.0.0      (from here on, the   100  2.1.0 [100 should be 10000]
+ *    1.0.1       png.h string is   10001  2.1.0
+ *    1.0.1a-e    identical to the  10002  from here on, the shared library
+ *    1.0.2       source version)   10002  is 2.V where V is the source code
+ *    1.0.2a-b                      10003  version, except as noted.
+ *    1.0.3                         10003
+ *    1.0.3a-d                      10004
+ *    1.0.4                         10004
+ *    1.0.4a-f                      10005
+ *    1.0.5 (+ 2 patches)           10005
+ *    1.0.5a-d                      10006
+ *    1.0.5e-r                      10100 (not source compatible)
+ *    1.0.5s-v                      10006 (not binary compatible)
+ *    1.0.6 (+ 3 patches)           10006 (still binary incompatible)
+ *    1.0.6d-f                      10007 (still binary incompatible)
+ *    1.0.6g                        10007
+ *    1.0.6h                        10007  10.6h (testing xy.z so-numbering)
+ *    1.0.6i                        10007  10.6i
+ *    1.0.6j                        10007  2.1.0.6j (incompatible with 1.0.0)
+ *    1.0.7beta11-14        DLLNUM  10007  2.1.0.7beta11-14 (binary compatible)
+ *    1.0.7beta15-18           1    10007  2.1.0.7beta15-18 (binary compatible)
+ *    1.0.7rc1-2               1    10007  2.1.0.7rc1-2 (binary compatible)
+ *    1.0.7                    1    10007  (still compatible)
+ *    1.0.8beta1-4             1    10008  2.1.0.8beta1-4
+ *    1.0.8rc1                 1    10008  2.1.0.8rc1
+ *    1.0.8                    1    10008  2.1.0.8
+ *    1.0.9beta1-6             1    10009  2.1.0.9beta1-6
+ *    1.0.9rc1                 1    10009  2.1.0.9rc1
+ *    1.0.9beta7-10            1    10009  2.1.0.9beta7-10
+ *    1.0.9rc2                 1    10009  2.1.0.9rc2
+ *    1.0.9                    1    10009  2.1.0.9
+ *    1.0.10beta1              1    10010  2.1.0.10beta1
+ *    1.0.10rc1                1    10010  2.1.0.10rc1
+ *    1.0.10                   1    10010  2.1.0.10
+ *    1.0.11beta1-3            1    10011  2.1.0.11beta1-3
+ *    1.0.11rc1                1    10011  2.1.0.11rc1
+ *    1.0.11                   1    10011  2.1.0.11
+ *    1.0.12beta1-2            2    10012  2.1.0.12beta1-2
+ *    1.0.12rc1                2    10012  2.1.0.12rc1
+ *    1.0.12                   2    10012  2.1.0.12
+ *    1.1.0a-f                 -    10100  2.1.1.0a-f (branch abandoned)
+ *    1.2.0beta1-2             2    10200  2.1.2.0beta1-2
+ *    1.2.0beta3-5             3    10200  3.1.2.0beta3-5
+ *    1.2.0rc1                 3    10200  3.1.2.0rc1
+ *    1.2.0                    3    10200  3.1.2.0
+ *    1.2.1beta1-4             3    10201  3.1.2.1beta1-4
+ *    1.2.1rc1-2               3    10201  3.1.2.1rc1-2
+ *    1.2.1                    3    10201  3.1.2.1
+ *    1.2.2beta1-6            12    10202  12.so.0.1.2.2beta1-6
+ *    1.0.13beta1             10    10013  10.so.0.1.0.13beta1
+ *    1.0.13rc1               10    10013  10.so.0.1.0.13rc1
+ *    1.2.2rc1                12    10202  12.so.0.1.2.2rc1
+ *    1.0.13                  10    10013  10.so.0.1.0.13
+ *    1.2.2                   12    10202  12.so.0.1.2.2
+ *    1.2.3rc1-6              12    10203  12.so.0.1.2.3rc1-6
+ *    1.2.3                   12    10203  12.so.0.1.2.3
+ *    1.2.4beta1-3            13    10204  12.so.0.1.2.4beta1-3
+ *    1.0.14rc1               13    10014  10.so.0.1.0.14rc1
+ *    1.2.4rc1                13    10204  12.so.0.1.2.4rc1
+ *    1.0.14                  10    10014  10.so.0.1.0.14
+ *    1.2.4                   13    10204  12.so.0.1.2.4
+ *    1.2.5beta1-2            13    10205  12.so.0.1.2.5beta1-2
+ *    1.0.15rc1-3             10    10015  10.so.0.1.0.15rc1-3
+ *    1.2.5rc1-3              13    10205  12.so.0.1.2.5rc1-3
+ *    1.0.15                  10    10015  10.so.0.1.0.15
+ *    1.2.5                   13    10205  12.so.0.1.2.5
+ *    1.2.6beta1-4            13    10206  12.so.0.1.2.6beta1-4
+ *    1.0.16                  10    10016  10.so.0.1.0.16
+ *    1.2.6                   13    10206  12.so.0.1.2.6
+ *    1.2.7beta1-2            13    10207  12.so.0.1.2.7beta1-2
+ *    1.0.17rc1               10    10017  12.so.0.1.0.17rc1
+ *    1.2.7rc1                13    10207  12.so.0.1.2.7rc1
+ *    1.0.17                  10    10017  12.so.0.1.0.17
+ *    1.2.7                   13    10207  12.so.0.1.2.7
+ *    1.2.8beta1-5            13    10208  12.so.0.1.2.8beta1-5
+ *    1.0.18rc1-5             10    10018  12.so.0.1.0.18rc1-5
+ *    1.2.8rc1-5              13    10208  12.so.0.1.2.8rc1-5
+ *    1.0.18                  10    10018  12.so.0.1.0.18
+ *    1.2.8                   13    10208  12.so.0.1.2.8
+ *    1.2.9beta1-3            13    10209  12.so.0.1.2.9beta1-3
+ *    1.2.9beta4-11           13    10209  12.so.0.9[.0]
+ *    1.2.9rc1                13    10209  12.so.0.9[.0]
+ *    1.2.9                   13    10209  12.so.0.9[.0]
+ *    1.2.10beta1-7           13    10210  12.so.0.10[.0]
+ *    1.2.10rc1-2             13    10210  12.so.0.10[.0]
+ *    1.2.10                  13    10210  12.so.0.10[.0]
+ *    1.4.0beta1-5            14    10400  14.so.0.0[.0]
+ *    1.2.11beta1-4           13    10211  12.so.0.11[.0]
+ *    1.4.0beta7-8            14    10400  14.so.0.0[.0]
+ *    1.2.11                  13    10211  12.so.0.11[.0]
+ *    1.2.12                  13    10212  12.so.0.12[.0]
+ *    1.4.0beta9-14           14    10400  14.so.0.0[.0]
+ *    1.2.13                  13    10213  12.so.0.13[.0]
+ *    1.4.0beta15-36          14    10400  14.so.0.0[.0]
+ *    1.4.0beta37-87          14    10400  14.so.14.0[.0]
+ *    1.4.0rc01               14    10400  14.so.14.0[.0]
+ *    1.4.0beta88-109         14    10400  14.so.14.0[.0]
+ *    1.4.0rc02-08            14    10400  14.so.14.0[.0]
+ *    1.4.0                   14    10400  14.so.14.0[.0]
+ *    1.4.1beta01-03          14    10401  14.so.14.1[.0]
+ *    1.4.1rc01               14    10401  14.so.14.1[.0]
+ *    1.4.1beta04-12          14    10401  14.so.14.1[.0]
+ *    1.4.1                   14    10401  14.so.14.1[.0]
+ *    1.4.2                   14    10402  14.so.14.2[.0]
+ *    1.4.3                   14    10403  14.so.14.3[.0]
+ *    1.4.4                   14    10404  14.so.14.4[.0]
+ *    1.5.0beta01-58          15    10500  15.so.15.0[.0]
+ *    1.5.0rc01-07            15    10500  15.so.15.0[.0]
+ *    1.5.0                   15    10500  15.so.15.0[.0]
+ *    1.5.1beta01-11          15    10501  15.so.15.1[.0]
+ *    1.5.1rc01-02            15    10501  15.so.15.1[.0]
+ *    1.5.1                   15    10501  15.so.15.1[.0]
+ *    1.5.2beta01-03          15    10502  15.so.15.2[.0]
+ *    1.5.2rc01-03            15    10502  15.so.15.2[.0]
+ *    1.5.2                   15    10502  15.so.15.2[.0]
+ *    1.5.3beta01-10          15    10503  15.so.15.3[.0]
+ *    1.5.3rc01-02            15    10503  15.so.15.3[.0]
+ *    1.5.3beta11             15    10503  15.so.15.3[.0]
+ *    1.5.3 [omitted]
+ *    1.5.4beta01-08          15    10504  15.so.15.4[.0]
+ *    1.5.4rc01               15    10504  15.so.15.4[.0]
+ *    1.5.4                   15    10504  15.so.15.4[.0]
+ *    1.5.5beta01-08          15    10505  15.so.15.5[.0]
+ *    1.5.5rc01               15    10505  15.so.15.5[.0]
+ *    1.5.5                   15    10505  15.so.15.5[.0]
+ *    1.5.6beta01-07          15    10506  15.so.15.6[.0]
+ *    1.5.6rc01-03            15    10506  15.so.15.6[.0]
+ *    1.5.6                   15    10506  15.so.15.6[.0]
+ *    1.5.7beta01-05          15    10507  15.so.15.7[.0]
+ *    1.5.7rc01-03            15    10507  15.so.15.7[.0]
+ *    1.5.7                   15    10507  15.so.15.7[.0]
+ *    1.5.8beta01             15    10508  15.so.15.8[.0]
+ *    1.5.8rc01               15    10508  15.so.15.8[.0]
+ *    1.5.8                   15    10508  15.so.15.8[.0]
+ *    1.5.9beta01-02          15    10509  15.so.15.9[.0]
+ *    1.5.9rc01               15    10509  15.so.15.9[.0]
+ *    1.5.9                   15    10509  15.so.15.9[.0]
+ *
+ *   Henceforth the source version will match the shared-library major
+ *   and minor numbers; the shared-library major version number will be
+ *   used for changes in backward compatibility, as it is intended.  The
+ *   PNG_LIBPNG_VER macro, which is not used within libpng but is available
+ *   for applications, is an unsigned integer of the form xyyzz corresponding
+ *   to the source version x.y.z (leading zeros in y and z).  Beta versions
+ *   were given the previous public release number plus a letter, until
+ *   version 1.0.6j; from then on they were given the upcoming public
+ *   release number plus "betaNN" or "rcN".
+ *
+ *   Binary incompatibility exists only when applications make direct access
+ *   to the info_ptr or png_ptr members through png.h, and the compiled
+ *   application is loaded with a different version of the library.
+ *
+ *   DLLNUM will change each time there are forward or backward changes
+ *   in binary compatibility (e.g., when a new feature is added).
+ *
+ * See libpng-manual.txt or libpng.3 for more information.  The PNG
+ * specification is available as a W3C Recommendation and as an ISO
+ * Specification, <http://www.w3.org/TR/2003/REC-PNG-20031110/
+ */
+/*
+ * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
+ *
+ * If you modify libpng you may insert additional notices immediately following
+ * this sentence.
+ *
+ * This code is released under the libpng license.
+ *
+ * libpng versions 1.2.6, August 15, 2004, through 1.5.9, February 18, 2012, are
+ * Copyright (c) 2004, 2006-2012 Glenn Randers-Pehrson, and are
+ * distributed according to the same disclaimer and license as libpng-1.2.5
+ * with the following individual added to the list of Contributing Authors:
+ *
+ *    Cosmin Truta
+ *
+ * libpng versions 1.0.7, July 1, 2000, through 1.2.5, October 3, 2002, are
+ * Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are
+ * distributed according to the same disclaimer and license as libpng-1.0.6
+ * with the following individuals added to the list of Contributing Authors:
+ *
+ *    Simon-Pierre Cadieux
+ *    Eric S. Raymond
+ *    Gilles Vollant
+ *
+ * and with the following additions to the disclaimer:
+ *
+ *    There is no warranty against interference with your enjoyment of the
+ *    library or against infringement.  There is no warranty that our
+ *    efforts or the library will fulfill any of your particular purposes
+ *    or needs.  This library is provided with all faults, and the entire
+ *    risk of satisfactory quality, performance, accuracy, and effort is with
+ *    the user.
+ *
+ * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
+ * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson, and are
+ * distributed according to the same disclaimer and license as libpng-0.96,
+ * with the following individuals added to the list of Contributing Authors:
+ *
+ *    Tom Lane
+ *    Glenn Randers-Pehrson
+ *    Willem van Schaik
+ *
+ * libpng versions 0.89, June 1996, through 0.96, May 1997, are
+ * Copyright (c) 1996, 1997 Andreas Dilger
+ * Distributed according to the same disclaimer and license as libpng-0.88,
+ * with the following individuals added to the list of Contributing Authors:
+ *
+ *    John Bowler
+ *    Kevin Bracey
+ *    Sam Bushell
+ *    Magnus Holmgren
+ *    Greg Roelofs
+ *    Tom Tanner
+ *
+ * libpng versions 0.5, May 1995, through 0.88, January 1996, are
+ * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
+ *
+ * For the purposes of this copyright and license, "Contributing Authors"
+ * is defined as the following set of individuals:
+ *
+ *    Andreas Dilger
+ *    Dave Martindale
+ *    Guy Eric Schalnat
+ *    Paul Schmidt
+ *    Tim Wegner
+ *
+ * The PNG Reference Library is supplied "AS IS".  The Contributing Authors
+ * and Group 42, Inc. disclaim all warranties, expressed or implied,
+ * including, without limitation, the warranties of merchantability and of
+ * fitness for any purpose.  The Contributing Authors and Group 42, Inc.
+ * assume no liability for direct, indirect, incidental, special, exemplary,
+ * or consequential damages, which may result from the use of the PNG
+ * Reference Library, even if advised of the possibility of such damage.
+ *
+ * Permission is hereby granted to use, copy, modify, and distribute this
+ * source code, or portions hereof, for any purpose, without fee, subject
+ * to the following restrictions:
+ *
+ *   1. The origin of this source code must not be misrepresented.
+ *
+ *   2. Altered versions must be plainly marked as such and must not
+ *      be misrepresented as being the original source.
+ *
+ *   3. This Copyright notice may not be removed or altered from
+ *      any source or altered source distribution.
+ *
+ * The Contributing Authors and Group 42, Inc. specifically permit, without
+ * fee, and encourage the use of this source code as a component to
+ * supporting the PNG file format in commercial products.  If you use this
+ * source code in a product, acknowledgment is not required but would be
+ * appreciated.
+ */
+/*
+ * A "png_get_copyright" function is available, for convenient use in "about"
+ * boxes and the like:
+ *
+ *     printf("%s", png_get_copyright(NULL));
+ *
+ * Also, the PNG logo (in PNG format, of course) is supplied in the
+ * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
+ */
+/*
+ * Libpng is OSI Certified Open Source Software.  OSI Certified is a
+ * certification mark of the Open Source Initiative.
+ */
+/*
+ * The contributing authors would like to thank all those who helped
+ * with testing, bug fixes, and patience.  This wouldn't have been
+ * possible without all of you.
+ *
+ * Thanks to Frank J. T. Wojcik for helping with the documentation.
+ */
+/*
+ * Y2K compliance in libpng:
+ * =========================
+ *
+ *    February 18, 2012
+ *
+ *    Since the PNG Development group is an ad-hoc body, we can't make
+ *    an official declaration.
+ *
+ *    This is your unofficial assurance that libpng from version 0.71 and
+ *    upward through 1.5.9 are Y2K compliant.  It is my belief that
+ *    earlier versions were also Y2K compliant.
+ *
+ *    Libpng only has two year fields.  One is a 2-byte unsigned integer
+ *    that will hold years up to 65535.  The other holds the date in text
+ *    format, and will hold years up to 9999.
+ *
+ *    The integer is
+ *        "png_uint_16 year" in png_time_struct.
+ *
+ *    The string is
+ *        "png_char time_buffer" in png_struct
+ *
+ *    There are seven time-related functions:
+ *        png.c: png_convert_to_rfc_1123() in png.c
+ *          (formerly png_convert_to_rfc_1152() in error)
+ *        png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
+ *        png_convert_from_time_t() in pngwrite.c
+ *        png_get_tIME() in pngget.c
+ *        png_handle_tIME() in pngrutil.c, called in pngread.c
+ *        png_set_tIME() in pngset.c
+ *        png_write_tIME() in pngwutil.c, called in pngwrite.c
+ *
+ *    All handle dates properly in a Y2K environment.  The
+ *    png_convert_from_time_t() function calls gmtime() to convert from system
+ *    clock time, which returns (year - 1900), which we properly convert to
+ *    the full 4-digit year.  There is a possibility that applications using
+ *    libpng are not passing 4-digit years into the png_convert_to_rfc_1123()
+ *    function, or that they are incorrectly passing only a 2-digit year
+ *    instead of "year - 1900" into the png_convert_from_struct_tm() function,
+ *    but this is not under our control.  The libpng documentation has always
+ *    stated that it works with 4-digit years, and the APIs have been
+ *    documented as such.
+ *
+ *    The tIME chunk itself is also Y2K compliant.  It uses a 2-byte unsigned
+ *    integer to hold the year, and can hold years as large as 65535.
+ *
+ *    zlib, upon which libpng depends, is also Y2K compliant.  It contains
+ *    no date-related code.
+ *
+ *       Glenn Randers-Pehrson
+ *       libpng maintainer
+ *       PNG Development Group
+ */
+#ifndef PNG_H
+#define PNG_H
+/* This is not the place to learn how to use libpng. The file libpng-manual.txt
+ * describes how to use libpng, and the file example.c summarizes it
+ * with some code on which to build.  This file is useful for looking
+ * at the actual function definitions and structure components.
+ *
+ * If you just need to read a PNG file and don't want to read the documentation
+ * skip to the end of this file and read the section entitled 'simplified API'.
+ */
+/* Version information for png.h - this should match the version in png.c */
+#define PNG_LIBPNG_VER_STRING "1.5.9"
+#define PNG_HEADER_VERSION_STRING \
+     " libpng version 1.5.9 - February 18, 2012\n"
+#define PNG_LIBPNG_VER_SONUM   15
+#define PNG_LIBPNG_VER_DLLNUM  15
+/* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
+#define PNG_LIBPNG_VER_MAJOR   1
+#define PNG_LIBPNG_VER_MINOR   5
+#define PNG_LIBPNG_VER_RELEASE 9
+/* This should match the numeric part of the final component of
+ * PNG_LIBPNG_VER_STRING, omitting any leading zero:
+ */
+#define PNG_LIBPNG_VER_BUILD  0
+/* Release Status */
+#define PNG_LIBPNG_BUILD_ALPHA    1
+#define PNG_LIBPNG_BUILD_BETA     2
+#define PNG_LIBPNG_BUILD_RC       3
+#define PNG_LIBPNG_BUILD_STABLE   4
+#define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7
+/* Release-Specific Flags */
+#define PNG_LIBPNG_BUILD_PATCH    8 /* Can be OR'ed with
+                                       PNG_LIBPNG_BUILD_STABLE only */
+#define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with
+                                       PNG_LIBPNG_BUILD_SPECIAL */
+#define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with
+                                       PNG_LIBPNG_BUILD_PRIVATE */
+#define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_BETA
+/* Careful here.  At one time, Guy wanted to use 082, but that would be octal.
+ * We must not include leading zeros.
+ * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only
+ * version 1.0.0 was mis-numbered 100 instead of 10000).  From
+ * version 1.0.1 it's    xxyyzz, where x=major, y=minor, z=release
+ */
+#define PNG_LIBPNG_VER 10509 /* 1.5.9 */
+/* Library configuration: these options cannot be changed after
+ * the library has been built.
+ */
+#ifndef PNGLCONF_H
+    /* If pnglibconf.h is missing, you can
+     * copy scripts/pnglibconf.h.prebuilt to pnglibconf.h
+     */
+#   include "pnglibconf.h"
+#endif
+#ifndef PNG_VERSION_INFO_ONLY
+#  ifndef PNG_BUILDING_SYMBOL_TABLE
+  /*
+   *   Standard header files (not needed for the version info or while
+   *   building symbol table -- see scripts/pnglibconf.dfa)
+   */
+#    ifdef PNG_SETJMP_SUPPORTED
+#      include <setjmp.h>
+#    endif
+    /* Need the time information for converting tIME chunks, it
+     * defines struct tm:
+     */
+#    ifdef PNG_CONVERT_tIME_SUPPORTED
+       /* "time.h" functions are not supported on all operating systems */
+#      include <time.h>
+#    endif
+#  endif
+/* Machine specific configuration. */
+#  include "pngconf.h"
+#endif
+/*
+ * Added at libpng-1.2.8
+ *
+ * Ref MSDN: Private as priority over Special
+ * VS_FF_PRIVATEBUILD File *was not* built using standard release
+ * procedures. If this value is given, the StringFileInfo block must
+ * contain a PrivateBuild string.
+ *
+ * VS_FF_SPECIALBUILD File *was* built by the original company using
+ * standard release procedures but is a variation of the standard
+ * file of the same version number. If this value is given, the
+ * StringFileInfo block must contain a SpecialBuild string.
+ */
+#ifdef PNG_USER_PRIVATEBUILD /* From pnglibconf.h */
+#  define PNG_LIBPNG_BUILD_TYPE \
+       (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE)
+#else
+#  ifdef PNG_LIBPNG_SPECIALBUILD
+#    define PNG_LIBPNG_BUILD_TYPE \
+         (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL)
+#  else
+#    define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE)
+#  endif
+#endif
+#ifndef PNG_VERSION_INFO_ONLY
+/* Inhibit C++ name-mangling for libpng functions but not for system calls. */
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+/* Version information for C files, stored in png.c.  This had better match
+ * the version above.
+ */
+#define png_libpng_ver png_get_header_ver(NULL)
+/* This file is arranged in several sections:
+ *
+ * 1. Any configuration options that can be specified by for the application
+ *    code when it is built.  (Build time configuration is in pnglibconf.h)
+ * 2. Type definitions (base types are defined in pngconf.h), structure
+ *    definitions.
+ * 3. Exported library functions.
+ *
+ * The library source code has additional files (principally pngpriv.h) that
+ * allow configuration of the library.
+ */
+/* Section 1: run time configuration
+ * See pnglibconf.h for build time configuration
+ *
+ * Run time configuration allows the application to choose between
+ * implementations of certain arithmetic APIs.  The default is set
+ * at build time and recorded in pnglibconf.h, but it is safe to
+ * override these (and only these) settings.  Note that this won't
+ * change what the library does, only application code, and the
+ * settings can (and probably should) be made on a per-file basis
+ * by setting the #defines before including png.h
+ *
+ * Use macros to read integers from PNG data or use the exported
+ * functions?
+ *   PNG_USE_READ_MACROS: use the macros (see below)  Note that
+ *     the macros evaluate their argument multiple times.
+ *   PNG_NO_USE_READ_MACROS: call the relevant library function.
+ *
+ * Use the alternative algorithm for compositing alpha samples that
+ * does not use division?
+ *   PNG_READ_COMPOSITE_NODIV_SUPPORTED: use the 'no division'
+ *      algorithm.
+ *   PNG_NO_READ_COMPOSITE_NODIV: use the 'division' algorithm.
+ *
+ * How to handle benign errors if PNG_ALLOW_BENIGN_ERRORS is
+ * false?
+ *   PNG_ALLOW_BENIGN_ERRORS: map calls to the benign error
+ *      APIs to png_warning.
+ * Otherwise the calls are mapped to png_error.
+ */
+/* Section 2: type definitions, including structures and compile time
+ * constants.
+ * See pngconf.h for base types that vary by machine/system
+ */
+/* This triggers a compiler error in png.c, if png.c and png.h
+ * do not agree upon the version number.
+ */
+typedef char* png_libpng_version_1_5_9;
+/* Three color definitions.  The order of the red, green, and blue, (and the
+ * exact size) is not important, although the size of the fields need to
+ * be png_byte or png_uint_16 (as defined below).
+ */
+typedef struct png_color_struct
+{
+   png_byte red;
+   png_byte green;
+   png_byte blue;
+} png_color;
+typedef png_color FAR * png_colorp;
+typedef PNG_CONST png_color FAR * png_const_colorp;
+typedef png_color FAR * FAR * png_colorpp;
+typedef struct png_color_16_struct
+{
+   png_byte index;    /* used for palette files */
+   png_uint_16 red;   /* for use in red green blue files */
+   png_uint_16 green;
+   png_uint_16 blue;
+   png_uint_16 gray;  /* for use in grayscale files */
+} png_color_16;
+typedef png_color_16 FAR * png_color_16p;
+typedef PNG_CONST png_color_16 FAR * png_const_color_16p;
+typedef png_color_16 FAR * FAR * png_color_16pp;
+typedef struct png_color_8_struct
+{
+   png_byte red;   /* for use in red green blue files */
+   png_byte green;
+   png_byte blue;
+   png_byte gray;  /* for use in grayscale files */
+   png_byte alpha; /* for alpha channel files */
+} png_color_8;
+typedef png_color_8 FAR * png_color_8p;
+typedef PNG_CONST png_color_8 FAR * png_const_color_8p;
+typedef png_color_8 FAR * FAR * png_color_8pp;
+/*
+ * The following two structures are used for the in-core representation
+ * of sPLT chunks.
+ */
+typedef struct png_sPLT_entry_struct
+{
+   png_uint_16 red;
+   png_uint_16 green;
+   png_uint_16 blue;
+   png_uint_16 alpha;
+   png_uint_16 frequency;
+} png_sPLT_entry;
+typedef png_sPLT_entry FAR * png_sPLT_entryp;
+typedef PNG_CONST png_sPLT_entry FAR * png_const_sPLT_entryp;
+typedef png_sPLT_entry FAR * FAR * png_sPLT_entrypp;
+/*  When the depth of the sPLT palette is 8 bits, the color and alpha samples
+ *  occupy the LSB of their respective members, and the MSB of each member
+ *  is zero-filled.  The frequency member always occupies the full 16 bits.
+ */
+typedef struct png_sPLT_struct
+{
+   png_charp name;           /* palette name */
+   png_byte depth;           /* depth of palette samples */
+   png_sPLT_entryp entries;  /* palette entries */
+   png_int_32 nentries;      /* number of palette entries */
+} png_sPLT_t;
+typedef png_sPLT_t FAR * png_sPLT_tp;
+typedef PNG_CONST png_sPLT_t FAR * png_const_sPLT_tp;
+typedef png_sPLT_t FAR * FAR * png_sPLT_tpp;
+#ifdef PNG_TEXT_SUPPORTED
+/* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,
+ * and whether that contents is compressed or not.  The "key" field
+ * points to a regular zero-terminated C string.  The "text" fields can be a
+ * regular C string, an empty string, or a NULL pointer.
+ * However, the structure returned by png_get_text() will always contain
+ * the "text" field as a regular zero-terminated C string (possibly
+ * empty), never a NULL pointer, so it can be safely used in printf() and
+ * other string-handling functions.  Note that the "itxt_length", "lang", and
+ * "lang_key" members of the structure only exist when the library is built
+ * with iTXt chunk support.  Prior to libpng-1.4.0 the library was built by
+ * default without iTXt support. Also note that when iTXt *is* supported,
+ * the "lang" and "lang_key" fields contain NULL pointers when the
+ * "compression" field contains * PNG_TEXT_COMPRESSION_NONE or
+ * PNG_TEXT_COMPRESSION_zTXt. Note that the "compression value" is not the
+ * same as what appears in the PNG tEXt/zTXt/iTXt chunk's "compression flag"
+ * which is always 0 or 1, or its "compression method" which is always 0.
+ */
+typedef struct png_text_struct
+{
+   int  compression;       /* compression value:
+                             -1: tEXt, none
+                              0: zTXt, deflate
+                              1: iTXt, none
+                              2: iTXt, deflate  */
+   png_charp key;          /* keyword, 1-79 character description of "text" */
+   png_charp text;         /* comment, may be an empty string (ie "")
+                              or a NULL pointer */
+   png_size_t text_length; /* length of the text string */
+   png_size_t itxt_length; /* length of the itxt string */
+   png_charp lang;         /* language code, 0-79 characters
+                              or a NULL pointer */
+   png_charp lang_key;     /* keyword translated UTF-8 string, 0 or more
+                              chars or a NULL pointer */
+} png_text;
+typedef png_text FAR * png_textp;
+typedef PNG_CONST png_text FAR * png_const_textp;
+typedef png_text FAR * FAR * png_textpp;
+#endif
+/* Supported compression types for text in PNG files (tEXt, and zTXt).
+ * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */
+#define PNG_TEXT_COMPRESSION_NONE_WR -3
+#define PNG_TEXT_COMPRESSION_zTXt_WR -2
+#define PNG_TEXT_COMPRESSION_NONE    -1
+#define PNG_TEXT_COMPRESSION_zTXt     0
+#define PNG_ITXT_COMPRESSION_NONE     1
+#define PNG_ITXT_COMPRESSION_zTXt     2
+#define PNG_TEXT_COMPRESSION_LAST     3  /* Not a valid value */
+/* png_time is a way to hold the time in an machine independent way.
+ * Two conversions are provided, both from time_t and struct tm.  There
+ * is no portable way to convert to either of these structures, as far
+ * as I know.  If you know of a portable way, send it to me.  As a side
+ * note - PNG has always been Year 2000 compliant!
+ */
+typedef struct png_time_struct
+{
+   png_uint_16 year; /* full year, as in, 1995 */
+   png_byte month;   /* month of year, 1 - 12 */
+   png_byte day;     /* day of month, 1 - 31 */
+   png_byte hour;    /* hour of day, 0 - 23 */
+   png_byte minute;  /* minute of hour, 0 - 59 */
+   png_byte second;  /* second of minute, 0 - 60 (for leap seconds) */
+} png_time;
+typedef png_time FAR * png_timep;
+typedef PNG_CONST png_time FAR * png_const_timep;
+typedef png_time FAR * FAR * png_timepp;
+#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) || \
+    defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
+/* png_unknown_chunk is a structure to hold queued chunks for which there is
+ * no specific support.  The idea is that we can use this to queue
+ * up private chunks for output even though the library doesn't actually
+ * know about their semantics.
+ */
+typedef struct png_unknown_chunk_t
+{
+    png_byte name[5];
+    png_byte *data;
+    png_size_t size;
+    /* libpng-using applications should NOT directly modify this byte. */
+    png_byte location; /* mode of operation at read time */
+}
+png_unknown_chunk;
+typedef png_unknown_chunk FAR * png_unknown_chunkp;
+typedef PNG_CONST png_unknown_chunk FAR * png_const_unknown_chunkp;
+typedef png_unknown_chunk FAR * FAR * png_unknown_chunkpp;
+#endif
+/* Values for the unknown chunk location byte */
+#define PNG_HAVE_IHDR  0x01
+#define PNG_HAVE_PLTE  0x02
+#define PNG_AFTER_IDAT 0x08
+/* The complete definition of png_info has, as of libpng-1.5.0,
+ * been moved into a separate header file that is not accessible to
+ * applications.  Read libpng-manual.txt or libpng.3 for more info.
+ */
+typedef struct png_info_def png_info;
+typedef png_info FAR * png_infop;
+typedef PNG_CONST png_info FAR * png_const_infop;
+typedef png_info FAR * FAR * png_infopp;
+/* Maximum positive integer used in PNG is (2^31)-1 */
+#define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL)
+#define PNG_UINT_32_MAX ((png_uint_32)(-1))
+#define PNG_SIZE_MAX ((png_size_t)(-1))
+/* These are constants for fixed point values encoded in the
+ * PNG specification manner (x100000)
+ */
+#define PNG_FP_1    100000
+#define PNG_FP_HALF  50000
+#define PNG_FP_MAX  ((png_fixed_point)0x7fffffffL)
+#define PNG_FP_MIN  (-PNG_FP_MAX)
+/* These describe the color_type field in png_info. */
+/* color type masks */
+#define PNG_COLOR_MASK_PALETTE    1
+#define PNG_COLOR_MASK_COLOR      2
+#define PNG_COLOR_MASK_ALPHA      4
+/* color types.  Note that not all combinations are legal */
+#define PNG_COLOR_TYPE_GRAY 0
+#define PNG_COLOR_TYPE_PALETTE  (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
+#define PNG_COLOR_TYPE_RGB        (PNG_COLOR_MASK_COLOR)
+#define PNG_COLOR_TYPE_RGB_ALPHA  (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
+#define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
+/* aliases */
+#define PNG_COLOR_TYPE_RGBA  PNG_COLOR_TYPE_RGB_ALPHA
+#define PNG_COLOR_TYPE_GA  PNG_COLOR_TYPE_GRAY_ALPHA
+/* This is for compression type. PNG 1.0-1.2 only define the single type. */
+#define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */
+#define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE
+/* This is for filter type. PNG 1.0-1.2 only define the single type. */
+#define PNG_FILTER_TYPE_BASE      0 /* Single row per-byte filtering */
+#define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */
+#define PNG_FILTER_TYPE_DEFAULT   PNG_FILTER_TYPE_BASE
+/* These are for the interlacing type.  These values should NOT be changed. */
+#define PNG_INTERLACE_NONE        0 /* Non-interlaced image */
+#define PNG_INTERLACE_ADAM7       1 /* Adam7 interlacing */
+#define PNG_INTERLACE_LAST        2 /* Not a valid value */
+/* These are for the oFFs chunk.  These values should NOT be changed. */
+#define PNG_OFFSET_PIXEL          0 /* Offset in pixels */
+#define PNG_OFFSET_MICROMETER     1 /* Offset in micrometers (1/10^6 meter) */
+#define PNG_OFFSET_LAST           2 /* Not a valid value */
+/* These are for the pCAL chunk.  These values should NOT be changed. */
+#define PNG_EQUATION_LINEAR       0 /* Linear transformation */
+#define PNG_EQUATION_BASE_E       1 /* Exponential base e transform */
+#define PNG_EQUATION_ARBITRARY    2 /* Arbitrary base exponential transform */
+#define PNG_EQUATION_HYPERBOLIC   3 /* Hyperbolic sine transformation */
+#define PNG_EQUATION_LAST         4 /* Not a valid value */
+/* These are for the sCAL chunk.  These values should NOT be changed. */
+#define PNG_SCALE_UNKNOWN         0 /* unknown unit (image scale) */
+#define PNG_SCALE_METER           1 /* meters per pixel */
+#define PNG_SCALE_RADIAN          2 /* radians per pixel */
+#define PNG_SCALE_LAST            3 /* Not a valid value */
+/* These are for the pHYs chunk.  These values should NOT be changed. */
+#define PNG_RESOLUTION_UNKNOWN    0 /* pixels/unknown unit (aspect ratio) */
+#define PNG_RESOLUTION_METER      1 /* pixels/meter */
+#define PNG_RESOLUTION_LAST       2 /* Not a valid value */
+/* These are for the sRGB chunk.  These values should NOT be changed. */
+#define PNG_sRGB_INTENT_PERCEPTUAL 0
+#define PNG_sRGB_INTENT_RELATIVE   1
+#define PNG_sRGB_INTENT_SATURATION 2
+#define PNG_sRGB_INTENT_ABSOLUTE   3
+#define PNG_sRGB_INTENT_LAST       4 /* Not a valid value */
+/* This is for text chunks */
+#define PNG_KEYWORD_MAX_LENGTH     79
+/* Maximum number of entries in PLTE/sPLT/tRNS arrays */
+#define PNG_MAX_PALETTE_LENGTH    256
+/* These determine if an ancillary chunk's data has been successfully read
+ * from the PNG header, or if the application has filled in the corresponding
+ * data in the info_struct to be written into the output file.  The values
+ * of the PNG_INFO_<chunk> defines should NOT be changed.
+ */
+#define PNG_INFO_gAMA 0x0001
+#define PNG_INFO_sBIT 0x0002
+#define PNG_INFO_cHRM 0x0004
+#define PNG_INFO_PLTE 0x0008
+#define PNG_INFO_tRNS 0x0010
+#define PNG_INFO_bKGD 0x0020
+#define PNG_INFO_hIST 0x0040
+#define PNG_INFO_pHYs 0x0080
+#define PNG_INFO_oFFs 0x0100
+#define PNG_INFO_tIME 0x0200
+#define PNG_INFO_pCAL 0x0400
+#define PNG_INFO_sRGB 0x0800   /* GR-P, 0.96a */
+#define PNG_INFO_iCCP 0x1000   /* ESR, 1.0.6 */
+#define PNG_INFO_sPLT 0x2000   /* ESR, 1.0.6 */
+#define PNG_INFO_sCAL 0x4000   /* ESR, 1.0.6 */
+#define PNG_INFO_IDAT 0x8000   /* ESR, 1.0.6 */
+/* This is used for the transformation routines, as some of them
+ * change these values for the row.  It also should enable using
+ * the routines for other purposes.
+ */
+typedef struct png_row_info_struct
+{
+   png_uint_32 width;    /* width of row */
+   png_size_t rowbytes;  /* number of bytes in row */
+   png_byte color_type;  /* color type of row */
+   png_byte bit_depth;   /* bit depth of row */
+   png_byte channels;    /* number of channels (1, 2, 3, or 4) */
+   png_byte pixel_depth; /* bits per pixel (depth * channels) */
+} png_row_info;
+typedef png_row_info FAR * png_row_infop;
+typedef png_row_info FAR * FAR * png_row_infopp;
+/* The complete definition of png_struct has, as of libpng-1.5.0,
+ * been moved into a separate header file that is not accessible to
+ * applications.  Read libpng-manual.txt or libpng.3 for more info.
+ */
+typedef struct png_struct_def png_struct;
+typedef PNG_CONST png_struct FAR * png_const_structp;
+typedef png_struct FAR * png_structp;
+/* These are the function types for the I/O functions and for the functions
+ * that allow the user to override the default I/O functions with his or her
+ * own.  The png_error_ptr type should match that of user-supplied warning
+ * and error functions, while the png_rw_ptr type should match that of the
+ * user read/write data functions.  Note that the 'write' function must not
+ * modify the buffer it is passed. The 'read' function, on the other hand, is
+ * expected to return the read data in the buffer.
+ */
+typedef PNG_CALLBACK(void, *png_error_ptr, (png_structp, png_const_charp));
+typedef PNG_CALLBACK(void, *png_rw_ptr, (png_structp, png_bytep, png_size_t));
+typedef PNG_CALLBACK(void, *png_flush_ptr, (png_structp));
+typedef PNG_CALLBACK(void, *png_read_status_ptr, (png_structp, png_uint_32,
+    int));
+typedef PNG_CALLBACK(void, *png_write_status_ptr, (png_structp, png_uint_32,
+    int));
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+typedef PNG_CALLBACK(void, *png_progressive_info_ptr, (png_structp, png_infop));
+typedef PNG_CALLBACK(void, *png_progressive_end_ptr, (png_structp, png_infop));
+/* The following callback receives png_uint_32 row_number, int pass for the
+ * png_bytep data of the row.  When transforming an interlaced image the
+ * row number is the row number within the sub-image of the interlace pass, so
+ * the value will increase to the height of the sub-image (not the full image)
+ * then reset to 0 for the next pass.
+ *
+ * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
+ * find the output pixel (x,y) given an interlaced sub-image pixel
+ * (row,col,pass).  (See below for these macros.)
+ */
+typedef PNG_CALLBACK(void, *png_progressive_row_ptr, (png_structp, png_bytep,
+    png_uint_32, int));
+#endif
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
+    defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
+typedef PNG_CALLBACK(void, *png_user_transform_ptr, (png_structp, png_row_infop,
+    png_bytep));
+#endif
+#ifdef PNG_USER_CHUNKS_SUPPORTED
+typedef PNG_CALLBACK(int, *png_user_chunk_ptr, (png_structp,
+    png_unknown_chunkp));
+#endif
+#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
+typedef PNG_CALLBACK(void, *png_unknown_chunk_ptr, (png_structp));
+#endif
+#ifdef PNG_SETJMP_SUPPORTED
+/* This must match the function definition in <setjmp.h>, and the application
+ * must include this before png.h to obtain the definition of jmp_buf.  The
+ * function is required to be PNG_NORETURN, but this is not checked.  If the
+ * function does return the application will crash via an abort() or similar
+ * system level call.
+ *
+ * If you get a warning here while building the library you may need to make
+ * changes to ensure that pnglibconf.h records the calling convention used by
+ * your compiler.  This may be very difficult - try using a different compiler
+ * to build the library!
+ */
+PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)), typedef);
+#endif
+/* Transform masks for the high-level interface */
+#define PNG_TRANSFORM_IDENTITY       0x0000    /* read and write */
+#define PNG_TRANSFORM_STRIP_16       0x0001    /* read only */
+#define PNG_TRANSFORM_STRIP_ALPHA    0x0002    /* read only */
+#define PNG_TRANSFORM_PACKING        0x0004    /* read and write */
+#define PNG_TRANSFORM_PACKSWAP       0x0008    /* read and write */
+#define PNG_TRANSFORM_EXPAND         0x0010    /* read only */
+#define PNG_TRANSFORM_INVERT_MONO    0x0020    /* read and write */
+#define PNG_TRANSFORM_SHIFT          0x0040    /* read and write */
+#define PNG_TRANSFORM_BGR            0x0080    /* read and write */
+#define PNG_TRANSFORM_SWAP_ALPHA     0x0100    /* read and write */
+#define PNG_TRANSFORM_SWAP_ENDIAN    0x0200    /* read and write */
+#define PNG_TRANSFORM_INVERT_ALPHA   0x0400    /* read and write */
+#define PNG_TRANSFORM_STRIP_FILLER   0x0800    /* write only */
+/* Added to libpng-1.2.34 */
+#define PNG_TRANSFORM_STRIP_FILLER_BEFORE PNG_TRANSFORM_STRIP_FILLER
+#define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */
+/* Added to libpng-1.4.0 */
+#define PNG_TRANSFORM_GRAY_TO_RGB   0x2000      /* read only */
+/* Added to libpng-1.5.4 */
+#define PNG_TRANSFORM_EXPAND_16     0x4000      /* read only */
+#define PNG_TRANSFORM_SCALE_16      0x8000      /* read only */
+/* Flags for MNG supported features */
+#define PNG_FLAG_MNG_EMPTY_PLTE     0x01
+#define PNG_FLAG_MNG_FILTER_64      0x04
+#define PNG_ALL_MNG_FEATURES        0x05
+/* NOTE: prior to 1.5 these functions had no 'API' style declaration,
+ * this allowed the zlib default functions to be used on Windows
+ * platforms.  In 1.5 the zlib default malloc (which just calls malloc and
+ * ignores the first argument) should be completely compatible with the
+ * following.
+ */
+typedef PNG_CALLBACK(png_voidp, *png_malloc_ptr, (png_structp,
+    png_alloc_size_t));
+typedef PNG_CALLBACK(void, *png_free_ptr, (png_structp, png_voidp));
+typedef png_struct FAR * FAR * png_structpp;
+/* Section 3: exported functions
+ * Here are the function definitions most commonly used.  This is not
+ * the place to find out how to use libpng.  See libpng-manual.txt for the
+ * full explanation, see example.c for the summary.  This just provides
+ * a simple one line description of the use of each function.
+ *
+ * The PNG_EXPORT() and PNG_EXPORTA() macros used below are defined in
+ * pngconf.h and in the *.dfn files in the scripts directory.
+ *
+ *   PNG_EXPORT(ordinal, type, name, (args));
+ *
+ *       ordinal:    ordinal that is used while building
+ *                   *.def files. The ordinal value is only
+ *                   relevant when preprocessing png.h with
+ *                   the *.dfn files for building symbol table
+ *                   entries, and are removed by pngconf.h.
+ *       type:       return type of the function
+ *       name:       function name
+ *       args:       function arguments, with types
+ *
+ * When we wish to append attributes to a function prototype we use
+ * the PNG_EXPORTA() macro instead.
+ *
+ *   PNG_EXPORTA(ordinal, type, name, (args), attributes);
+ *
+ *       ordinal, type, name, and args: same as in PNG_EXPORT().
+ *       attributes: function attributes
+ */
+/* Returns the version number of the library */
+PNG_EXPORT(1, png_uint_32, png_access_version_number, (void));
+/* Tell lib we have already handled the first <num_bytes> magic bytes.
+ * Handling more than 8 bytes from the beginning of the file is an error.
+ */
+PNG_EXPORT(2, void, png_set_sig_bytes, (png_structp png_ptr, int num_bytes));
+/* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
+ * PNG file.  Returns zero if the supplied bytes match the 8-byte PNG
+ * signature, and non-zero otherwise.  Having num_to_check == 0 or
+ * start > 7 will always fail (ie return non-zero).
+ */
+PNG_EXPORT(3, int, png_sig_cmp, (png_const_bytep sig, png_size_t start,
+    png_size_t num_to_check));
+/* Simple signature checking function.  This is the same as calling
+ * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n).
+ */
+#define png_check_sig(sig, n) !png_sig_cmp((sig), 0, (n))
+/* Allocate and initialize png_ptr struct for reading, and any other memory. */
+PNG_EXPORTA(4, png_structp, png_create_read_struct,
+    (png_const_charp user_png_ver, png_voidp error_ptr,
+    png_error_ptr error_fn, png_error_ptr warn_fn),
+    PNG_ALLOCATED);
+/* Allocate and initialize png_ptr struct for writing, and any other memory */
+PNG_EXPORTA(5, png_structp, png_create_write_struct,
+    (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
+    png_error_ptr warn_fn),
+    PNG_ALLOCATED);
+PNG_EXPORT(6, png_size_t, png_get_compression_buffer_size,
+    (png_const_structp png_ptr));
+PNG_EXPORT(7, void, png_set_compression_buffer_size, (png_structp png_ptr,
+    png_size_t size));
+/* Moved from pngconf.h in 1.4.0 and modified to ensure setjmp/longjmp
+ * match up.
+ */
+#ifdef PNG_SETJMP_SUPPORTED
+/* This function returns the jmp_buf built in to *png_ptr.  It must be
+ * supplied with an appropriate 'longjmp' function to use on that jmp_buf
+ * unless the default error function is overridden in which case NULL is
+ * acceptable.  The size of the jmp_buf is checked against the actual size
+ * allocated by the library - the call will return NULL on a mismatch
+ * indicating an ABI mismatch.
+ */
+PNG_EXPORT(8, jmp_buf*, png_set_longjmp_fn, (png_structp png_ptr,
+    png_longjmp_ptr longjmp_fn, size_t jmp_buf_size));
+#  define png_jmpbuf(png_ptr) \
+      (*png_set_longjmp_fn((png_ptr), longjmp, sizeof (jmp_buf)))
+#else
+#  define png_jmpbuf(png_ptr) \
+      (LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP)
+#endif
+/* This function should be used by libpng applications in place of
+ * longjmp(png_ptr->jmpbuf, val).  If longjmp_fn() has been set, it
+ * will use it; otherwise it will call PNG_ABORT().  This function was
+ * added in libpng-1.5.0.
+ */
+PNG_EXPORTA(9, void, png_longjmp, (png_structp png_ptr, int val),
+    PNG_NORETURN);
+#ifdef PNG_READ_SUPPORTED
+/* Reset the compression stream */
+PNG_EXPORT(10, int, png_reset_zstream, (png_structp png_ptr));
+#endif
+/* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */
+#ifdef PNG_USER_MEM_SUPPORTED
+PNG_EXPORTA(11, png_structp, png_create_read_struct_2,
+    (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
+    png_error_ptr warn_fn,
+    png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn),
+    PNG_ALLOCATED);
+PNG_EXPORTA(12, png_structp, png_create_write_struct_2,
+    (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
+    png_error_ptr warn_fn,
+    png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn),
+    PNG_ALLOCATED);
+#endif
+/* Write the PNG file signature. */
+PNG_EXPORT(13, void, png_write_sig, (png_structp png_ptr));
+/* Write a PNG chunk - size, type, (optional) data, CRC. */
+PNG_EXPORT(14, void, png_write_chunk, (png_structp png_ptr, png_const_bytep
+    chunk_name, png_const_bytep data, png_size_t length));
+/* Write the start of a PNG chunk - length and chunk name. */
+PNG_EXPORT(15, void, png_write_chunk_start, (png_structp png_ptr,
+    png_const_bytep chunk_name, png_uint_32 length));
+/* Write the data of a PNG chunk started with png_write_chunk_start(). */
+PNG_EXPORT(16, void, png_write_chunk_data, (png_structp png_ptr,
+    png_const_bytep data, png_size_t length));
+/* Finish a chunk started with png_write_chunk_start() (includes CRC). */
+PNG_EXPORT(17, void, png_write_chunk_end, (png_structp png_ptr));
+/* Allocate and initialize the info structure */
+PNG_EXPORTA(18, png_infop, png_create_info_struct, (png_structp png_ptr),
+    PNG_ALLOCATED);
+PNG_EXPORT(19, void, png_info_init_3, (png_infopp info_ptr,
+    png_size_t png_info_struct_size));
+/* Writes all the PNG information before the image. */
+PNG_EXPORT(20, void, png_write_info_before_PLTE,
+    (png_structp png_ptr, png_infop info_ptr));
+PNG_EXPORT(21, void, png_write_info,
+    (png_structp png_ptr, png_infop info_ptr));
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+/* Read the information before the actual image data. */
+PNG_EXPORT(22, void, png_read_info,
+    (png_structp png_ptr, png_infop info_ptr));
+#endif
+#ifdef PNG_TIME_RFC1123_SUPPORTED
+PNG_EXPORT(23, png_const_charp, png_convert_to_rfc1123,
+    (png_structp png_ptr,
+    png_const_timep ptime));
+#endif
+#ifdef PNG_CONVERT_tIME_SUPPORTED
+/* Convert from a struct tm to png_time */
+PNG_EXPORT(24, void, png_convert_from_struct_tm, (png_timep ptime,
+    PNG_CONST struct tm FAR * ttime));
+/* Convert from time_t to png_time.  Uses gmtime() */
+PNG_EXPORT(25, void, png_convert_from_time_t,
+    (png_timep ptime, time_t ttime));
+#endif /* PNG_CONVERT_tIME_SUPPORTED */
+#ifdef PNG_READ_EXPAND_SUPPORTED
+/* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
+PNG_EXPORT(26, void, png_set_expand, (png_structp png_ptr));
+PNG_EXPORT(27, void, png_set_expand_gray_1_2_4_to_8, (png_structp png_ptr));
+PNG_EXPORT(28, void, png_set_palette_to_rgb, (png_structp png_ptr));
+PNG_EXPORT(29, void, png_set_tRNS_to_alpha, (png_structp png_ptr));
+#endif
+#ifdef PNG_READ_EXPAND_16_SUPPORTED
+/* Expand to 16-bit channels, forces conversion of palette to RGB and expansion
+ * of a tRNS chunk if present.
+ */
+PNG_EXPORT(221, void, png_set_expand_16, (png_structp png_ptr));
+#endif
+#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
+/* Use blue, green, red order for pixels. */
+PNG_EXPORT(30, void, png_set_bgr, (png_structp png_ptr));
+#endif
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+/* Expand the grayscale to 24-bit RGB if necessary. */
+PNG_EXPORT(31, void, png_set_gray_to_rgb, (png_structp png_ptr));
+#endif
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+/* Reduce RGB to grayscale. */
+#define PNG_ERROR_ACTION_NONE  1
+#define PNG_ERROR_ACTION_WARN  2
+#define PNG_ERROR_ACTION_ERROR 3
+#define PNG_RGB_TO_GRAY_DEFAULT (-1)/*for red/green coefficients*/
+PNG_FP_EXPORT(32, void, png_set_rgb_to_gray, (png_structp png_ptr,
+    int error_action, double red, double green));
+PNG_FIXED_EXPORT(33, void, png_set_rgb_to_gray_fixed, (png_structp png_ptr,
+    int error_action, png_fixed_point red, png_fixed_point green));
+PNG_EXPORT(34, png_byte, png_get_rgb_to_gray_status, (png_const_structp
+    png_ptr));
+#endif
+#ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED
+PNG_EXPORT(35, void, png_build_grayscale_palette, (int bit_depth,
+    png_colorp palette));
+#endif
+#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+/* How the alpha channel is interpreted - this affects how the color channels of
+ * a PNG file are returned when an alpha channel, or tRNS chunk in a palette
+ * file, is present.
+ *
+ * This has no effect on the way pixels are written into a PNG output
+ * datastream. The color samples in a PNG datastream are never premultiplied
+ * with the alpha samples.
+ *
+ * The default is to return data according to the PNG specification: the alpha
+ * channel is a linear measure of the contribution of the pixel to the
+ * corresponding composited pixel.  The gamma encoded color channels must be
+ * scaled according to the contribution and to do this it is necessary to undo
+ * the encoding, scale the color values, perform the composition and reencode
+ * the values.  This is the 'PNG' mode.
+ *
+ * The alternative is to 'associate' the alpha with the color information by
+ * storing color channel values that have been scaled by the alpha.  The
+ * advantage is that the color channels can be resampled (the image can be
+ * scaled) in this form.  The disadvantage is that normal practice is to store
+ * linear, not (gamma) encoded, values and this requires 16-bit channels for
+ * still images rather than the 8-bit channels that are just about sufficient if
+ * gamma encoding is used.  In addition all non-transparent pixel values,
+ * including completely opaque ones, must be gamma encoded to produce the final
+ * image.  This is the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' mode (the
+ * latter being the two common names for associated alpha color channels.)
+ *
+ * Since it is not necessary to perform arithmetic on opaque color values so
+ * long as they are not to be resampled and are in the final color space it is
+ * possible to optimize the handling of alpha by storing the opaque pixels in
+ * the PNG format (adjusted for the output color space) while storing partially
+ * opaque pixels in the standard, linear, format.  The accuracy required for
+ * standard alpha composition is relatively low, because the pixels are
+ * isolated, therefore typically the accuracy loss in storing 8-bit linear
+ * values is acceptable.  (This is not true if the alpha channel is used to
+ * simulate transparency over large areas - use 16 bits or the PNG mode in
+ * this case!)  This is the 'OPTIMIZED' mode.  For this mode a pixel is
+ * treated as opaque only if the alpha value is equal to the maximum value.
+ *
+ * The final choice is to gamma encode the alpha channel as well.  This is
+ * broken because, in practice, no implementation that uses this choice
+ * correctly undoes the encoding before handling alpha composition.  Use this
+ * choice only if other serious errors in the software or hardware you use
+ * mandate it; the typical serious error is for dark halos to appear around
+ * opaque areas of the composited PNG image because of arithmetic overflow.
+ *
+ * The API function png_set_alpha_mode specifies which of these choices to use
+ * with an enumerated 'mode' value and the gamma of the required output:
+ */
+#define PNG_ALPHA_PNG           0 /* according to the PNG standard */
+#define PNG_ALPHA_STANDARD      1 /* according to Porter/Duff */
+#define PNG_ALPHA_ASSOCIATED    1 /* as above; this is the normal practice */
+#define PNG_ALPHA_PREMULTIPLIED 1 /* as above */
+#define PNG_ALPHA_OPTIMIZED     2 /* 'PNG' for opaque pixels, else 'STANDARD' */
+#define PNG_ALPHA_BROKEN        3 /* the alpha channel is gamma encoded */
+PNG_FP_EXPORT(227, void, png_set_alpha_mode, (png_structp png_ptr, int mode,
+    double output_gamma));
+PNG_FIXED_EXPORT(228, void, png_set_alpha_mode_fixed, (png_structp png_ptr,
+    int mode, png_fixed_point output_gamma));
+#endif
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_ALPHA_MODE_SUPPORTED)
+/* The output_gamma value is a screen gamma in libpng terminology: it expresses
+ * how to decode the output values, not how they are encoded.  The values used
+ * correspond to the normal numbers used to describe the overall gamma of a
+ * computer display system; for example 2.2 for an sRGB conformant system.  The
+ * values are scaled by 100000 in the _fixed version of the API (so 220000 for
+ * sRGB.)
+ *
+ * The inverse of the value is always used to provide a default for the PNG file
+ * encoding if it has no gAMA chunk and if png_set_gamma() has not been called
+ * to override the PNG gamma information.
+ *
+ * When the ALPHA_OPTIMIZED mode is selected the output gamma is used to encode
+ * opaque pixels however pixels with lower alpha values are not encoded,
+ * regardless of the output gamma setting.
+ *
+ * When the standard Porter Duff handling is requested with mode 1 the output
+ * encoding is set to be linear and the output_gamma value is only relevant
+ * as a default for input data that has no gamma information.  The linear output
+ * encoding will be overridden if png_set_gamma() is called - the results may be
+ * highly unexpected!
+ *
+ * The following numbers are derived from the sRGB standard and the research
+ * behind it.  sRGB is defined to be approximated by a PNG gAMA chunk value of
+ * 0.45455 (1/2.2) for PNG.  The value implicitly includes any viewing
+ * correction required to take account of any differences in the color
+ * environment of the original scene and the intended display environment; the
+ * value expresses how to *decode* the image for display, not how the original
+ * data was *encoded*.
+ *
+ * sRGB provides a peg for the PNG standard by defining a viewing environment.
+ * sRGB itself, and earlier TV standards, actually use a more complex transform
+ * (a linear portion then a gamma 2.4 power law) than PNG can express.  (PNG is
+ * limited to simple power laws.)  By saying that an image for direct display on
+ * an sRGB conformant system should be stored with a gAMA chunk value of 45455
+ * (11.3.3.2 and 11.3.3.5 of the ISO PNG specification) the PNG specification
+ * makes it possible to derive values for other display systems and
+ * environments.
+ *
+ * The Mac value is deduced from the sRGB based on an assumption that the actual
+ * extra viewing correction used in early Mac display systems was implemented as
+ * a power 1.45 lookup table.
+ *
+ * Any system where a programmable lookup table is used or where the behavior of
+ * the final display device characteristics can be changed requires system
+ * specific code to obtain the current characteristic.  However this can be
+ * difficult and most PNG gamma correction only requires an approximate value.
+ *
+ * By default, if png_set_alpha_mode() is not called, libpng assumes that all
+ * values are unencoded, linear, values and that the output device also has a
+ * linear characteristic.  This is only very rarely correct - it is invariably
+ * better to call png_set_alpha_mode() with PNG_DEFAULT_sRGB than rely on the
+ * default if you don't know what the right answer is!
+ *
+ * The special value PNG_GAMMA_MAC_18 indicates an older Mac system (pre Mac OS
+ * 10.6) which used a correction table to implement a somewhat lower gamma on an
+ * otherwise sRGB system.
+ *
+ * Both these values are reserved (not simple gamma values) in order to allow
+ * more precise correction internally in the future.
+ *
+ * NOTE: the following values can be passed to either the fixed or floating
+ * point APIs, but the floating point API will also accept floating point
+ * values.
+ */
+#define PNG_DEFAULT_sRGB -1       /* sRGB gamma and color space */
+#define PNG_GAMMA_MAC_18 -2       /* Old Mac '1.8' gamma and color space */
+#define PNG_GAMMA_sRGB   220000   /* Television standards--matches sRGB gamma */
+#define PNG_GAMMA_LINEAR PNG_FP_1 /* Linear */
+#endif
+/* The following are examples of calls to png_set_alpha_mode to achieve the
+ * required overall gamma correction and, where necessary, alpha
+ * premultiplication.
+ *
+ * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
+ *    This is the default libpng handling of the alpha channel - it is not
+ *    pre-multiplied into the color components.  In addition the call states
+ *    that the output is for a sRGB system and causes all PNG files without gAMA
+ *    chunks to be assumed to be encoded using sRGB.
+ *
+ * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
+ *    In this case the output is assumed to be something like an sRGB conformant
+ *    display preceeded by a power-law lookup table of power 1.45.  This is how
+ *    early Mac systems behaved.
+ *
+ * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR);
+ *    This is the classic Jim Blinn approach and will work in academic
+ *    environments where everything is done by the book.  It has the shortcoming
+ *    of assuming that input PNG data with no gamma information is linear - this
+ *    is unlikely to be correct unless the PNG files where generated locally.
+ *    Most of the time the output precision will be so low as to show
+ *    significant banding in dark areas of the image.
+ *
+ * png_set_expand_16(pp);
+ * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB);
+ *    This is a somewhat more realistic Jim Blinn inspired approach.  PNG files
+ *    are assumed to have the sRGB encoding if not marked with a gamma value and
+ *    the output is always 16 bits per component.  This permits accurate scaling
+ *    and processing of the data.  If you know that your input PNG files were
+ *    generated locally you might need to replace PNG_DEFAULT_sRGB with the
+ *    correct value for your system.
+ *
+ * png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB);
+ *    If you just need to composite the PNG image onto an existing background
+ *    and if you control the code that does this you can use the optimization
+ *    setting.  In this case you just copy completely opaque pixels to the
+ *    output.  For pixels that are not completely transparent (you just skip
+ *    those) you do the composition math using png_composite or png_composite_16
+ *    below then encode the resultant 8-bit or 16-bit values to match the output
+ *    encoding.
+ *
+ * Other cases
+ *    If neither the PNG nor the standard linear encoding work for you because
+ *    of the software or hardware you use then you have a big problem.  The PNG
+ *    case will probably result in halos around the image.  The linear encoding
+ *    will probably result in a washed out, too bright, image (it's actually too
+ *    contrasty.)  Try the ALPHA_OPTIMIZED mode above - this will probably
+ *    substantially reduce the halos.  Alternatively try:
+ *
+ * png_set_alpha_mode(pp, PNG_ALPHA_BROKEN, PNG_DEFAULT_sRGB);
+ *    This option will also reduce the halos, but there will be slight dark
+ *    halos round the opaque parts of the image where the background is light.
+ *    In the OPTIMIZED mode the halos will be light halos where the background
+ *    is dark.  Take your pick - the halos are unavoidable unless you can get
+ *    your hardware/software fixed!  (The OPTIMIZED approach is slightly
+ *    faster.)
+ *
+ * When the default gamma of PNG files doesn't match the output gamma.
+ *    If you have PNG files with no gamma information png_set_alpha_mode allows
+ *    you to provide a default gamma, but it also sets the ouput gamma to the
+ *    matching value.  If you know your PNG files have a gamma that doesn't
+ *    match the output you can take advantage of the fact that
+ *    png_set_alpha_mode always sets the output gamma but only sets the PNG
+ *    default if it is not already set:
+ *
+ * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
+ * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
+ *    The first call sets both the default and the output gamma values, the
+ *    second call overrides the output gamma without changing the default.  This
+ *    is easier than achieving the same effect with png_set_gamma.  You must use
+ *    PNG_ALPHA_PNG for the first call - internal checking in png_set_alpha will
+ *    fire if more than one call to png_set_alpha_mode and png_set_background is
+ *    made in the same read operation, however multiple calls with PNG_ALPHA_PNG
+ *    are ignored.
+ */
+#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
+PNG_EXPORT(36, void, png_set_strip_alpha, (png_structp png_ptr));
+#endif
+#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
+    defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
+PNG_EXPORT(37, void, png_set_swap_alpha, (png_structp png_ptr));
+#endif
+#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
+    defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
+PNG_EXPORT(38, void, png_set_invert_alpha, (png_structp png_ptr));
+#endif
+#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
+/* Add a filler byte to 8-bit Gray or 24-bit RGB images. */
+PNG_EXPORT(39, void, png_set_filler, (png_structp png_ptr, png_uint_32 filler,
+    int flags));
+/* The values of the PNG_FILLER_ defines should NOT be changed */
+#  define PNG_FILLER_BEFORE 0
+#  define PNG_FILLER_AFTER 1
+/* Add an alpha byte to 8-bit Gray or 24-bit RGB images. */
+PNG_EXPORT(40, void, png_set_add_alpha,
+    (png_structp png_ptr, png_uint_32 filler,
+    int flags));
+#endif /* PNG_READ_FILLER_SUPPORTED || PNG_WRITE_FILLER_SUPPORTED */
+#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
+/* Swap bytes in 16-bit depth files. */
+PNG_EXPORT(41, void, png_set_swap, (png_structp png_ptr));
+#endif
+#if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
+/* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
+PNG_EXPORT(42, void, png_set_packing, (png_structp png_ptr));
+#endif
+#if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
+    defined(PNG_WRITE_PACKSWAP_SUPPORTED)
+/* Swap packing order of pixels in bytes. */
+PNG_EXPORT(43, void, png_set_packswap, (png_structp png_ptr));
+#endif
+#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
+/* Converts files to legal bit depths. */
+PNG_EXPORT(44, void, png_set_shift, (png_structp png_ptr, png_const_color_8p
+    true_bits));
+#endif
+#if defined(PNG_READ_INTERLACING_SUPPORTED) || \
+    defined(PNG_WRITE_INTERLACING_SUPPORTED)
+/* Have the code handle the interlacing.  Returns the number of passes.
+ * MUST be called before png_read_update_info or png_start_read_image,
+ * otherwise it will not have the desired effect.  Note that it is still
+ * necessary to call png_read_row or png_read_rows png_get_image_height
+ * times for each pass.
+*/
+PNG_EXPORT(45, int, png_set_interlace_handling, (png_structp png_ptr));
+#endif
+#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
+/* Invert monochrome files */
+PNG_EXPORT(46, void, png_set_invert_mono, (png_structp png_ptr));
+#endif
+#ifdef PNG_READ_BACKGROUND_SUPPORTED
+/* Handle alpha and tRNS by replacing with a background color.  Prior to
+ * libpng-1.5.4 this API must not be called before the PNG file header has been
+ * read.  Doing so will result in unexpected behavior and possible warnings or
+ * errors if the PNG file contains a bKGD chunk.
+ */
+PNG_FP_EXPORT(47, void, png_set_background, (png_structp png_ptr,
+    png_const_color_16p background_color, int background_gamma_code,
+    int need_expand, double background_gamma));
+PNG_FIXED_EXPORT(215, void, png_set_background_fixed, (png_structp png_ptr,
+    png_const_color_16p background_color, int background_gamma_code,
+    int need_expand, png_fixed_point background_gamma));
+#endif
+#ifdef PNG_READ_BACKGROUND_SUPPORTED
+#  define PNG_BACKGROUND_GAMMA_UNKNOWN 0
+#  define PNG_BACKGROUND_GAMMA_SCREEN  1
+#  define PNG_BACKGROUND_GAMMA_FILE    2
+#  define PNG_BACKGROUND_GAMMA_UNIQUE  3
+#endif
+#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+/* Scale a 16-bit depth file down to 8-bit, accurately. */
+PNG_EXPORT(229, void, png_set_scale_16, (png_structp png_ptr));
+#endif
+#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
+#define PNG_READ_16_TO_8 SUPPORTED /* Name prior to 1.5.4 */
+/* Strip the second byte of information from a 16-bit depth file. */
+PNG_EXPORT(48, void, png_set_strip_16, (png_structp png_ptr));
+#endif
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+/* Turn on quantizing, and reduce the palette to the number of colors
+ * available.
+ */
+PNG_EXPORT(49, void, png_set_quantize,
+    (png_structp png_ptr, png_colorp palette,
+    int num_palette, int maximum_colors, png_const_uint_16p histogram,
+    int full_quantize));
+#endif
+#ifdef PNG_READ_GAMMA_SUPPORTED
+/* The threshold on gamma processing is configurable but hard-wired into the
+ * library.  The following is the floating point variant.
+ */
+#define PNG_GAMMA_THRESHOLD (PNG_GAMMA_THRESHOLD_FIXED*.00001)
+/* Handle gamma correction. Screen_gamma=(display_exponent).
+ * NOTE: this API simply sets the screen and file gamma values. It will
+ * therefore override the value for gamma in a PNG file if it is called after
+ * the file header has been read - use with care  - call before reading the PNG
+ * file for best results!
+ *
+ * These routines accept the same gamma values as png_set_alpha_mode (described
+ * above).  The PNG_GAMMA_ defines and PNG_DEFAULT_sRGB can be passed to either
+ * API (floating point or fixed.)  Notice, however, that the 'file_gamma' value
+ * is the inverse of a 'screen gamma' value.
+ */
+PNG_FP_EXPORT(50, void, png_set_gamma,
+    (png_structp png_ptr, double screen_gamma,
+    double override_file_gamma));
+PNG_FIXED_EXPORT(208, void, png_set_gamma_fixed, (png_structp png_ptr,
+    png_fixed_point screen_gamma, png_fixed_point override_file_gamma));
+#endif
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+/* Set how many lines between output flushes - 0 for no flushing */
+PNG_EXPORT(51, void, png_set_flush, (png_structp png_ptr, int nrows));
+/* Flush the current PNG output buffer */
+PNG_EXPORT(52, void, png_write_flush, (png_structp png_ptr));
+#endif
+/* Optional update palette with requested transformations */
+PNG_EXPORT(53, void, png_start_read_image, (png_structp png_ptr));
+/* Optional call to update the users info structure */
+PNG_EXPORT(54, void, png_read_update_info,
+    (png_structp png_ptr, png_infop info_ptr));
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+/* Read one or more rows of image data. */
+PNG_EXPORT(55, void, png_read_rows, (png_structp png_ptr, png_bytepp row,
+    png_bytepp display_row, png_uint_32 num_rows));
+#endif
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+/* Read a row of data. */
+PNG_EXPORT(56, void, png_read_row, (png_structp png_ptr, png_bytep row,
+    png_bytep display_row));
+#endif
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+/* Read the whole image into memory at once. */
+PNG_EXPORT(57, void, png_read_image, (png_structp png_ptr, png_bytepp image));
+#endif
+/* Write a row of image data */
+PNG_EXPORT(58, void, png_write_row,
+    (png_structp png_ptr, png_const_bytep row));
+/* Write a few rows of image data: (*row) is not written; however, the type
+ * is declared as writeable to maintain compatibility with previous versions
+ * of libpng and to allow the 'display_row' array from read_rows to be passed
+ * unchanged to write_rows.
+ */
+PNG_EXPORT(59, void, png_write_rows, (png_structp png_ptr, png_bytepp row,
+    png_uint_32 num_rows));
+/* Write the image data */
+PNG_EXPORT(60, void, png_write_image,
+    (png_structp png_ptr, png_bytepp image));
+/* Write the end of the PNG file. */
+PNG_EXPORT(61, void, png_write_end,
+    (png_structp png_ptr, png_infop info_ptr));
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+/* Read the end of the PNG file. */
+PNG_EXPORT(62, void, png_read_end, (png_structp png_ptr, png_infop info_ptr));
+#endif
+/* Free any memory associated with the png_info_struct */
+PNG_EXPORT(63, void, png_destroy_info_struct, (png_structp png_ptr,
+    png_infopp info_ptr_ptr));
+/* Free any memory associated with the png_struct and the png_info_structs */
+PNG_EXPORT(64, void, png_destroy_read_struct, (png_structpp png_ptr_ptr,
+    png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr));
+/* Free any memory associated with the png_struct and the png_info_structs */
+PNG_EXPORT(65, void, png_destroy_write_struct, (png_structpp png_ptr_ptr,
+    png_infopp info_ptr_ptr));
+/* Set the libpng method of handling chunk CRC errors */
+PNG_EXPORT(66, void, png_set_crc_action,
+    (png_structp png_ptr, int crit_action, int ancil_action));
+/* Values for png_set_crc_action() say how to handle CRC errors in
+ * ancillary and critical chunks, and whether to use the data contained
+ * therein.  Note that it is impossible to "discard" data in a critical
+ * chunk.  For versions prior to 0.90, the action was always error/quit,
+ * whereas in version 0.90 and later, the action for CRC errors in ancillary
+ * chunks is warn/discard.  These values should NOT be changed.
+ *
+ *      value                       action:critical     action:ancillary
+ */
+#define PNG_CRC_DEFAULT       0  /* error/quit          warn/discard data */
+#define PNG_CRC_ERROR_QUIT    1  /* error/quit          error/quit        */
+#define PNG_CRC_WARN_DISCARD  2  /* (INVALID)           warn/discard data */
+#define PNG_CRC_WARN_USE      3  /* warn/use data       warn/use data     */
+#define PNG_CRC_QUIET_USE     4  /* quiet/use data      quiet/use data    */
+#define PNG_CRC_NO_CHANGE     5  /* use current value   use current value */
+/* These functions give the user control over the scan-line filtering in
+ * libpng and the compression methods used by zlib.  These functions are
+ * mainly useful for testing, as the defaults should work with most users.
+ * Those users who are tight on memory or want faster performance at the
+ * expense of compression can modify them.  See the compression library
+ * header file (zlib.h) for an explination of the compression functions.
+ */
+/* Set the filtering method(s) used by libpng.  Currently, the only valid
+ * value for "method" is 0.
+ */
+PNG_EXPORT(67, void, png_set_filter,
+    (png_structp png_ptr, int method, int filters));
+/* Flags for png_set_filter() to say which filters to use.  The flags
+ * are chosen so that they don't conflict with real filter types
+ * below, in case they are supplied instead of the #defined constants.
+ * These values should NOT be changed.
+ */
+#define PNG_NO_FILTERS     0x00
+#define PNG_FILTER_NONE    0x08
+#define PNG_FILTER_SUB     0x10
+#define PNG_FILTER_UP      0x20
+#define PNG_FILTER_AVG     0x40
+#define PNG_FILTER_PAETH   0x80
+#define PNG_ALL_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP | \
+                         PNG_FILTER_AVG | PNG_FILTER_PAETH)
+/* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
+ * These defines should NOT be changed.
+ */
+#define PNG_FILTER_VALUE_NONE  0
+#define PNG_FILTER_VALUE_SUB   1
+#define PNG_FILTER_VALUE_UP    2
+#define PNG_FILTER_VALUE_AVG   3
+#define PNG_FILTER_VALUE_PAETH 4
+#define PNG_FILTER_VALUE_LAST  5
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* EXPERIMENTAL */
+/* The "heuristic_method" is given by one of the PNG_FILTER_HEURISTIC_
+ * defines, either the default (minimum-sum-of-absolute-differences), or
+ * the experimental method (weighted-minimum-sum-of-absolute-differences).
+ *
+ * Weights are factors >= 1.0, indicating how important it is to keep the
+ * filter type consistent between rows.  Larger numbers mean the current
+ * filter is that many times as likely to be the same as the "num_weights"
+ * previous filters.  This is cumulative for each previous row with a weight.
+ * There needs to be "num_weights" values in "filter_weights", or it can be
+ * NULL if the weights aren't being specified.  Weights have no influence on
+ * the selection of the first row filter.  Well chosen weights can (in theory)
+ * improve the compression for a given image.
+ *
+ * Costs are factors >= 1.0 indicating the relative decoding costs of a
+ * filter type.  Higher costs indicate more decoding expense, and are
+ * therefore less likely to be selected over a filter with lower computational
+ * costs.  There needs to be a value in "filter_costs" for each valid filter
+ * type (given by PNG_FILTER_VALUE_LAST), or it can be NULL if you aren't
+ * setting the costs.  Costs try to improve the speed of decompression without
+ * unduly increasing the compressed image size.
+ *
+ * A negative weight or cost indicates the default value is to be used, and
+ * values in the range [0.0, 1.0) indicate the value is to remain unchanged.
+ * The default values for both weights and costs are currently 1.0, but may
+ * change if good general weighting/cost heuristics can be found.  If both
+ * the weights and costs are set to 1.0, this degenerates the WEIGHTED method
+ * to the UNWEIGHTED method, but with added encoding time/computation.
+ */
+PNG_FP_EXPORT(68, void, png_set_filter_heuristics, (png_structp png_ptr,
+    int heuristic_method, int num_weights, png_const_doublep filter_weights,
+    png_const_doublep filter_costs));
+PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed,
+    (png_structp png_ptr,
+    int heuristic_method, int num_weights, png_const_fixed_point_p
+    filter_weights, png_const_fixed_point_p filter_costs));
+#endif /*  PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
+/* Heuristic used for row filter selection.  These defines should NOT be
+ * changed.
+ */
+#define PNG_FILTER_HEURISTIC_DEFAULT    0  /* Currently "UNWEIGHTED" */
+#define PNG_FILTER_HEURISTIC_UNWEIGHTED 1  /* Used by libpng < 0.95 */
+#define PNG_FILTER_HEURISTIC_WEIGHTED   2  /* Experimental feature */
+#define PNG_FILTER_HEURISTIC_LAST       3  /* Not a valid value */
+#ifdef PNG_WRITE_SUPPORTED
+/* Set the library compression level.  Currently, valid values range from
+ * 0 - 9, corresponding directly to the zlib compression levels 0 - 9
+ * (0 - no compression, 9 - "maximal" compression).  Note that tests have
+ * shown that zlib compression levels 3-6 usually perform as well as level 9
+ * for PNG images, and do considerably fewer caclulations.  In the future,
+ * these values may not correspond directly to the zlib compression levels.
+ */
+PNG_EXPORT(69, void, png_set_compression_level,
+    (png_structp png_ptr, int level));
+PNG_EXPORT(70, void, png_set_compression_mem_level, (png_structp png_ptr,
+    int mem_level));
+PNG_EXPORT(71, void, png_set_compression_strategy, (png_structp png_ptr,
+    int strategy));
+/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
+ * smaller value of window_bits if it can do so safely.
+ */
+PNG_EXPORT(72, void, png_set_compression_window_bits, (png_structp png_ptr,
+    int window_bits));
+PNG_EXPORT(73, void, png_set_compression_method, (png_structp png_ptr,
+    int method));
+#endif
+#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
+/* Also set zlib parameters for compressing non-IDAT chunks */
+PNG_EXPORT(222, void, png_set_text_compression_level,
+    (png_structp png_ptr, int level));
+PNG_EXPORT(223, void, png_set_text_compression_mem_level, (png_structp png_ptr,
+    int mem_level));
+PNG_EXPORT(224, void, png_set_text_compression_strategy, (png_structp png_ptr,
+    int strategy));
+/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
+ * smaller value of window_bits if it can do so safely.
+ */
+PNG_EXPORT(225, void, png_set_text_compression_window_bits, (png_structp
+    png_ptr, int window_bits));
+PNG_EXPORT(226, void, png_set_text_compression_method, (png_structp png_ptr,
+    int method));
+#endif /* PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED */
+/* These next functions are called for input/output, memory, and error
+ * handling.  They are in the file pngrio.c, pngwio.c, and pngerror.c,
+ * and call standard C I/O routines such as fread(), fwrite(), and
+ * fprintf().  These functions can be made to use other I/O routines
+ * at run time for those applications that need to handle I/O in a
+ * different manner by calling png_set_???_fn().  See libpng-manual.txt for
+ * more information.
+ */
+#ifdef PNG_STDIO_SUPPORTED
+/* Initialize the input/output for the PNG file to the default functions. */
+PNG_EXPORT(74, void, png_init_io, (png_structp png_ptr, png_FILE_p fp));
+#endif
+/* Replace the (error and abort), and warning functions with user
+ * supplied functions.  If no messages are to be printed you must still
+ * write and use replacement functions. The replacement error_fn should
+ * still do a longjmp to the last setjmp location if you are using this
+ * method of error handling.  If error_fn or warning_fn is NULL, the
+ * default function will be used.
+ */
+PNG_EXPORT(75, void, png_set_error_fn,
+    (png_structp png_ptr, png_voidp error_ptr,
+    png_error_ptr error_fn, png_error_ptr warning_fn));
+/* Return the user pointer associated with the error functions */
+PNG_EXPORT(76, png_voidp, png_get_error_ptr, (png_const_structp png_ptr));
+/* Replace the default data output functions with a user supplied one(s).
+ * If buffered output is not used, then output_flush_fn can be set to NULL.
+ * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time
+ * output_flush_fn will be ignored (and thus can be NULL).
+ * It is probably a mistake to use NULL for output_flush_fn if
+ * write_data_fn is not also NULL unless you have built libpng with
+ * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's
+ * default flush function, which uses the standard *FILE structure, will
+ * be used.
+ */
+PNG_EXPORT(77, void, png_set_write_fn, (png_structp png_ptr, png_voidp io_ptr,
+    png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn));
+/* Replace the default data input function with a user supplied one. */
+PNG_EXPORT(78, void, png_set_read_fn, (png_structp png_ptr, png_voidp io_ptr,
+    png_rw_ptr read_data_fn));
+/* Return the user pointer associated with the I/O functions */
+PNG_EXPORT(79, png_voidp, png_get_io_ptr, (png_structp png_ptr));
+PNG_EXPORT(80, void, png_set_read_status_fn, (png_structp png_ptr,
+    png_read_status_ptr read_row_fn));
+PNG_EXPORT(81, void, png_set_write_status_fn, (png_structp png_ptr,
+    png_write_status_ptr write_row_fn));
+#ifdef PNG_USER_MEM_SUPPORTED
+/* Replace the default memory allocation functions with user supplied one(s). */
+PNG_EXPORT(82, void, png_set_mem_fn, (png_structp png_ptr, png_voidp mem_ptr,
+    png_malloc_ptr malloc_fn, png_free_ptr free_fn));
+/* Return the user pointer associated with the memory functions */
+PNG_EXPORT(83, png_voidp, png_get_mem_ptr, (png_const_structp png_ptr));
+#endif
+#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
+PNG_EXPORT(84, void, png_set_read_user_transform_fn, (png_structp png_ptr,
+    png_user_transform_ptr read_user_transform_fn));
+#endif
+#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
+PNG_EXPORT(85, void, png_set_write_user_transform_fn, (png_structp png_ptr,
+    png_user_transform_ptr write_user_transform_fn));
+#endif
+#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
+PNG_EXPORT(86, void, png_set_user_transform_info, (png_structp png_ptr,
+    png_voidp user_transform_ptr, int user_transform_depth,
+    int user_transform_channels));
+/* Return the user pointer associated with the user transform functions */
+PNG_EXPORT(87, png_voidp, png_get_user_transform_ptr,
+    (png_const_structp png_ptr));
+#endif
+#ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED
+/* Return information about the row currently being processed.  Note that these
+ * APIs do not fail but will return unexpected results if called outside a user
+ * transform callback.  Also note that when transforming an interlaced image the
+ * row number is the row number within the sub-image of the interlace pass, so
+ * the value will increase to the height of the sub-image (not the full image)
+ * then reset to 0 for the next pass.
+ *
+ * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
+ * find the output pixel (x,y) given an interlaced sub-image pixel
+ * (row,col,pass).  (See below for these macros.)
+ */
+PNG_EXPORT(217, png_uint_32, png_get_current_row_number, (png_const_structp));
+PNG_EXPORT(218, png_byte, png_get_current_pass_number, (png_const_structp));
+#endif
+#ifdef PNG_USER_CHUNKS_SUPPORTED
+PNG_EXPORT(88, void, png_set_read_user_chunk_fn, (png_structp png_ptr,
+    png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));
+PNG_EXPORT(89, png_voidp, png_get_user_chunk_ptr, (png_const_structp png_ptr));
+#endif
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+/* Sets the function callbacks for the push reader, and a pointer to a
+ * user-defined structure available to the callback functions.
+ */
+PNG_EXPORT(90, void, png_set_progressive_read_fn, (png_structp png_ptr,
+    png_voidp progressive_ptr, png_progressive_info_ptr info_fn,
+    png_progressive_row_ptr row_fn, png_progressive_end_ptr end_fn));
+/* Returns the user pointer associated with the push read functions */
+PNG_EXPORT(91, png_voidp, png_get_progressive_ptr, (png_const_structp png_ptr));
+/* Function to be called when data becomes available */
+PNG_EXPORT(92, void, png_process_data,
+    (png_structp png_ptr, png_infop info_ptr,
+    png_bytep buffer, png_size_t buffer_size));
+/* A function which may be called *only* within png_process_data to stop the
+ * processing of any more data.  The function returns the number of bytes
+ * remaining, excluding any that libpng has cached internally.  A subsequent
+ * call to png_process_data must supply these bytes again.  If the argument
+ * 'save' is set to true the routine will first save all the pending data and
+ * will always return 0.
+ */
+PNG_EXPORT(219, png_size_t, png_process_data_pause, (png_structp, int save));
+/* A function which may be called *only* outside (after) a call to
+ * png_process_data.  It returns the number of bytes of data to skip in the
+ * input.  Normally it will return 0, but if it returns a non-zero value the
+ * application must skip than number of bytes of input data and pass the
+ * following data to the next call to png_process_data.
+ */
+PNG_EXPORT(220, png_uint_32, png_process_data_skip, (png_structp));
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+/* Function that combines rows.  'new_row' is a flag that should come from
+ * the callback and be non-NULL if anything needs to be done; the library
+ * stores its own version of the new data internally and ignores the passed
+ * in value.
+ */
+PNG_EXPORT(93, void, png_progressive_combine_row, (png_structp png_ptr,
+    png_bytep old_row, png_const_bytep new_row));
+#endif /* PNG_READ_INTERLACING_SUPPORTED */
+#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
+PNG_EXPORTA(94, png_voidp, png_malloc,
+    (png_structp png_ptr, png_alloc_size_t size),
+    PNG_ALLOCATED);
+/* Added at libpng version 1.4.0 */
+PNG_EXPORTA(95, png_voidp, png_calloc,
+    (png_structp png_ptr, png_alloc_size_t size),
+    PNG_ALLOCATED);
+/* Added at libpng version 1.2.4 */
+PNG_EXPORTA(96, png_voidp, png_malloc_warn, (png_structp png_ptr,
+    png_alloc_size_t size), PNG_ALLOCATED);
+/* Frees a pointer allocated by png_malloc() */
+PNG_EXPORT(97, void, png_free, (png_structp png_ptr, png_voidp ptr));
+/* Free data that was allocated internally */
+PNG_EXPORT(98, void, png_free_data,
+    (png_structp png_ptr, png_infop info_ptr, png_uint_32 free_me, int num));
+/* Reassign responsibility for freeing existing data, whether allocated
+ * by libpng or by the application */
+PNG_EXPORT(99, void, png_data_freer,
+    (png_structp png_ptr, png_infop info_ptr, int freer, png_uint_32 mask));
+/* Assignments for png_data_freer */
+#define PNG_DESTROY_WILL_FREE_DATA 1
+#define PNG_SET_WILL_FREE_DATA 1
+#define PNG_USER_WILL_FREE_DATA 2
+/* Flags for png_ptr->free_me and info_ptr->free_me */
+#define PNG_FREE_HIST 0x0008
+#define PNG_FREE_ICCP 0x0010
+#define PNG_FREE_SPLT 0x0020
+#define PNG_FREE_ROWS 0x0040
+#define PNG_FREE_PCAL 0x0080
+#define PNG_FREE_SCAL 0x0100
+#define PNG_FREE_UNKN 0x0200
+#define PNG_FREE_LIST 0x0400
+#define PNG_FREE_PLTE 0x1000
+#define PNG_FREE_TRNS 0x2000
+#define PNG_FREE_TEXT 0x4000
+#define PNG_FREE_ALL  0x7fff
+#define PNG_FREE_MUL  0x4220 /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */
+#ifdef PNG_USER_MEM_SUPPORTED
+PNG_EXPORTA(100, png_voidp, png_malloc_default, (png_structp png_ptr,
+    png_alloc_size_t size), PNG_ALLOCATED);
+PNG_EXPORT(101, void, png_free_default, (png_structp png_ptr, png_voidp ptr));
+#endif
+#ifdef PNG_ERROR_TEXT_SUPPORTED
+/* Fatal error in PNG image of libpng - can't continue */
+PNG_EXPORTA(102, void, png_error,
+    (png_structp png_ptr, png_const_charp error_message),
+    PNG_NORETURN);
+/* The same, but the chunk name is prepended to the error string. */
+PNG_EXPORTA(103, void, png_chunk_error, (png_structp png_ptr,
+    png_const_charp error_message), PNG_NORETURN);
+#else
+/* Fatal error in PNG image of libpng - can't continue */
+PNG_EXPORTA(104, void, png_err, (png_structp png_ptr), PNG_NORETURN);
+#endif
+#ifdef PNG_WARNINGS_SUPPORTED
+/* Non-fatal error in libpng.  Can continue, but may have a problem. */
+PNG_EXPORT(105, void, png_warning, (png_structp png_ptr,
+    png_const_charp warning_message));
+/* Non-fatal error in libpng, chunk name is prepended to message. */
+PNG_EXPORT(106, void, png_chunk_warning, (png_structp png_ptr,
+    png_const_charp warning_message));
+#endif
+#ifdef PNG_BENIGN_ERRORS_SUPPORTED
+/* Benign error in libpng.  Can continue, but may have a problem.
+ * User can choose whether to handle as a fatal error or as a warning. */
+#  undef png_benign_error
+PNG_EXPORT(107, void, png_benign_error, (png_structp png_ptr,
+    png_const_charp warning_message));
+/* Same, chunk name is prepended to message. */
+#  undef png_chunk_benign_error
+PNG_EXPORT(108, void, png_chunk_benign_error, (png_structp png_ptr,
+    png_const_charp warning_message));
+PNG_EXPORT(109, void, png_set_benign_errors,
+    (png_structp png_ptr, int allowed));
+#else
+#  ifdef PNG_ALLOW_BENIGN_ERRORS
+#    define png_benign_error png_warning
+#    define png_chunk_benign_error png_chunk_warning
+#  else
+#    define png_benign_error png_error
+#    define png_chunk_benign_error png_chunk_error
+#  endif
+#endif
+/* The png_set_<chunk> functions are for storing values in the png_info_struct.
+ * Similarly, the png_get_<chunk> calls are used to read values from the
+ * png_info_struct, either storing the parameters in the passed variables, or
+ * setting pointers into the png_info_struct where the data is stored.  The
+ * png_get_<chunk> functions return a non-zero value if the data was available
+ * in info_ptr, or return zero and do not change any of the parameters if the
+ * data was not available.
+ *
+ * These functions should be used instead of directly accessing png_info
+ * to avoid problems with future changes in the size and internal layout of
+ * png_info_struct.
+ */
+/* Returns "flag" if chunk data is valid in info_ptr. */
+PNG_EXPORT(110, png_uint_32, png_get_valid,
+    (png_const_structp png_ptr, png_const_infop info_ptr,
+    png_uint_32 flag));
+/* Returns number of bytes needed to hold a transformed row. */
+PNG_EXPORT(111, png_size_t, png_get_rowbytes, (png_const_structp png_ptr,
+    png_const_infop info_ptr));
+#ifdef PNG_INFO_IMAGE_SUPPORTED
+/* Returns row_pointers, which is an array of pointers to scanlines that was
+ * returned from png_read_png().
+ */
+PNG_EXPORT(112, png_bytepp, png_get_rows,
+    (png_const_structp png_ptr, png_const_infop info_ptr));
+/* Set row_pointers, which is an array of pointers to scanlines for use
+ * by png_write_png().
+ */
+PNG_EXPORT(113, void, png_set_rows, (png_structp png_ptr,
+    png_infop info_ptr, png_bytepp row_pointers));
+#endif
+/* Returns number of color channels in image. */
+PNG_EXPORT(114, png_byte, png_get_channels,
+    (png_const_structp png_ptr, png_const_infop info_ptr));
+#ifdef PNG_EASY_ACCESS_SUPPORTED
+/* Returns image width in pixels. */
+PNG_EXPORT(115, png_uint_32, png_get_image_width, (png_const_structp png_ptr,
+    png_const_infop info_ptr));
+/* Returns image height in pixels. */
+PNG_EXPORT(116, png_uint_32, png_get_image_height, (png_const_structp png_ptr,
+    png_const_infop info_ptr));
+/* Returns image bit_depth. */
+PNG_EXPORT(117, png_byte, png_get_bit_depth,
+    (png_const_structp png_ptr, png_const_infop info_ptr));
+/* Returns image color_type. */
+PNG_EXPORT(118, png_byte, png_get_color_type, (png_const_structp png_ptr,
+    png_const_infop info_ptr));
+/* Returns image filter_type. */
+PNG_EXPORT(119, png_byte, png_get_filter_type, (png_const_structp png_ptr,
+    png_const_infop info_ptr));
+/* Returns image interlace_type. */
+PNG_EXPORT(120, png_byte, png_get_interlace_type, (png_const_structp png_ptr,
+    png_const_infop info_ptr));
+/* Returns image compression_type. */
+PNG_EXPORT(121, png_byte, png_get_compression_type, (png_const_structp png_ptr,
+    png_const_infop info_ptr));
+/* Returns image resolution in pixels per meter, from pHYs chunk data. */
+PNG_EXPORT(122, png_uint_32, png_get_pixels_per_meter,
+    (png_const_structp png_ptr, png_const_infop info_ptr));
+PNG_EXPORT(123, png_uint_32, png_get_x_pixels_per_meter,
+    (png_const_structp png_ptr, png_const_infop info_ptr));
+PNG_EXPORT(124, png_uint_32, png_get_y_pixels_per_meter,
+    (png_const_structp png_ptr, png_const_infop info_ptr));
+/* Returns pixel aspect ratio, computed from pHYs chunk data.  */
+PNG_FP_EXPORT(125, float, png_get_pixel_aspect_ratio,
+    (png_const_structp png_ptr, png_const_infop info_ptr));
+PNG_FIXED_EXPORT(210, png_fixed_point, png_get_pixel_aspect_ratio_fixed,
+    (png_const_structp png_ptr, png_const_infop info_ptr));
+/* Returns image x, y offset in pixels or microns, from oFFs chunk data. */
+PNG_EXPORT(126, png_int_32, png_get_x_offset_pixels,
+    (png_const_structp png_ptr, png_const_infop info_ptr));
+PNG_EXPORT(127, png_int_32, png_get_y_offset_pixels,
+    (png_const_structp png_ptr, png_const_infop info_ptr));
+PNG_EXPORT(128, png_int_32, png_get_x_offset_microns,
+    (png_const_structp png_ptr, png_const_infop info_ptr));
+PNG_EXPORT(129, png_int_32, png_get_y_offset_microns,
+    (png_const_structp png_ptr, png_const_infop info_ptr));
+#endif /* PNG_EASY_ACCESS_SUPPORTED */
+/* Returns pointer to signature string read from PNG header */
+PNG_EXPORT(130, png_const_bytep, png_get_signature,
+    (png_const_structp png_ptr, png_infop info_ptr));
+#ifdef PNG_bKGD_SUPPORTED
+PNG_EXPORT(131, png_uint_32, png_get_bKGD,
+    (png_const_structp png_ptr, png_infop info_ptr,
+    png_color_16p *background));
+#endif
+#ifdef PNG_bKGD_SUPPORTED
+PNG_EXPORT(132, void, png_set_bKGD, (png_structp png_ptr, png_infop info_ptr,
+    png_const_color_16p background));
+#endif
+#ifdef PNG_cHRM_SUPPORTED
+PNG_FP_EXPORT(133, png_uint_32, png_get_cHRM, (png_const_structp png_ptr,
+   png_const_infop info_ptr, double *white_x, double *white_y, double *red_x,
+    double *red_y, double *green_x, double *green_y, double *blue_x,
+    double *blue_y));
+PNG_FP_EXPORT(230, png_uint_32, png_get_cHRM_XYZ, (png_structp png_ptr,
+    png_const_infop info_ptr, double *red_X, double *red_Y, double *red_Z,
+    double *green_X, double *green_Y, double *green_Z, double *blue_X,
+    double *blue_Y, double *blue_Z));
+#ifdef PNG_FIXED_POINT_SUPPORTED /* Otherwise not implemented */
+PNG_FIXED_EXPORT(134, png_uint_32, png_get_cHRM_fixed,
+    (png_const_structp png_ptr,
+    png_const_infop info_ptr, png_fixed_point *int_white_x,
+    png_fixed_point *int_white_y, png_fixed_point *int_red_x,
+    png_fixed_point *int_red_y, png_fixed_point *int_green_x,
+    png_fixed_point *int_green_y, png_fixed_point *int_blue_x,
+    png_fixed_point *int_blue_y));
+#endif
+PNG_FIXED_EXPORT(231, png_uint_32, png_get_cHRM_XYZ_fixed,
+    (png_structp png_ptr, png_const_infop info_ptr,
+    png_fixed_point *int_red_X, png_fixed_point *int_red_Y,
+    png_fixed_point *int_red_Z, png_fixed_point *int_green_X,
+    png_fixed_point *int_green_Y, png_fixed_point *int_green_Z,
+    png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y,
+    png_fixed_point *int_blue_Z));
+#endif
+#ifdef PNG_cHRM_SUPPORTED
+PNG_FP_EXPORT(135, void, png_set_cHRM,
+    (png_structp png_ptr, png_infop info_ptr,
+    double white_x, double white_y, double red_x, double red_y, double green_x,
+    double green_y, double blue_x, double blue_y));
+PNG_FP_EXPORT(232, void, png_set_cHRM_XYZ, (png_structp png_ptr,
+    png_infop info_ptr, double red_X, double red_Y, double red_Z,
+    double green_X, double green_Y, double green_Z, double blue_X,
+    double blue_Y, double blue_Z));
+PNG_FIXED_EXPORT(136, void, png_set_cHRM_fixed, (png_structp png_ptr,
+    png_infop info_ptr, png_fixed_point int_white_x,
+    png_fixed_point int_white_y, png_fixed_point int_red_x,
+    png_fixed_point int_red_y, png_fixed_point int_green_x,
+    png_fixed_point int_green_y, png_fixed_point int_blue_x,
+    png_fixed_point int_blue_y));
+PNG_FIXED_EXPORT(233, void, png_set_cHRM_XYZ_fixed, (png_structp png_ptr,
+    png_infop info_ptr, png_fixed_point int_red_X, png_fixed_point int_red_Y,
+    png_fixed_point int_red_Z, png_fixed_point int_green_X,
+    png_fixed_point int_green_Y, png_fixed_point int_green_Z,
+    png_fixed_point int_blue_X, png_fixed_point int_blue_Y,
+    png_fixed_point int_blue_Z));
+#endif
+#ifdef PNG_gAMA_SUPPORTED
+PNG_FP_EXPORT(137, png_uint_32, png_get_gAMA,
+    (png_const_structp png_ptr, png_const_infop info_ptr,
+    double *file_gamma));
+PNG_FIXED_EXPORT(138, png_uint_32, png_get_gAMA_fixed,
+    (png_const_structp png_ptr, png_const_infop info_ptr,
+    png_fixed_point *int_file_gamma));
+#endif
+#ifdef PNG_gAMA_SUPPORTED
+PNG_FP_EXPORT(139, void, png_set_gAMA, (png_structp png_ptr,
+    png_infop info_ptr, double file_gamma));
+PNG_FIXED_EXPORT(140, void, png_set_gAMA_fixed, (png_structp png_ptr,
+    png_infop info_ptr, png_fixed_point int_file_gamma));
+#endif
+#ifdef PNG_hIST_SUPPORTED
+PNG_EXPORT(141, png_uint_32, png_get_hIST,
+    (png_const_structp png_ptr, png_const_infop info_ptr,
+    png_uint_16p *hist));
+#endif
+#ifdef PNG_hIST_SUPPORTED
+PNG_EXPORT(142, void, png_set_hIST, (png_structp png_ptr,
+    png_infop info_ptr, png_const_uint_16p hist));
+#endif
+PNG_EXPORT(143, png_uint_32, png_get_IHDR,
+    (png_structp png_ptr, png_infop info_ptr,
+    png_uint_32 *width, png_uint_32 *height, int *bit_depth, int *color_type,
+    int *interlace_method, int *compression_method, int *filter_method));
+PNG_EXPORT(144, void, png_set_IHDR,
+    (png_structp png_ptr, png_infop info_ptr,
+    png_uint_32 width, png_uint_32 height, int bit_depth, int color_type,
+    int interlace_method, int compression_method, int filter_method));
+#ifdef PNG_oFFs_SUPPORTED
+PNG_EXPORT(145, png_uint_32, png_get_oFFs,
+    (png_const_structp png_ptr, png_const_infop info_ptr,
+    png_int_32 *offset_x, png_int_32 *offset_y, int *unit_type));
+#endif
+#ifdef PNG_oFFs_SUPPORTED
+PNG_EXPORT(146, void, png_set_oFFs,
+    (png_structp png_ptr, png_infop info_ptr,
+    png_int_32 offset_x, png_int_32 offset_y, int unit_type));
+#endif
+#ifdef PNG_pCAL_SUPPORTED
+PNG_EXPORT(147, png_uint_32, png_get_pCAL,
+    (png_const_structp png_ptr, png_const_infop info_ptr,
+    png_charp *purpose, png_int_32 *X0, png_int_32 *X1, int *type,
+    int *nparams,
+    png_charp *units, png_charpp *params));
+#endif
+#ifdef PNG_pCAL_SUPPORTED
+PNG_EXPORT(148, void, png_set_pCAL, (png_structp png_ptr,
+    png_infop info_ptr,
+    png_const_charp purpose, png_int_32 X0, png_int_32 X1, int type,
+    int nparams, png_const_charp units, png_charpp params));
+#endif
+#ifdef PNG_pHYs_SUPPORTED
+PNG_EXPORT(149, png_uint_32, png_get_pHYs,
+    (png_const_structp png_ptr, png_const_infop info_ptr,
+    png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type));
+#endif
+#ifdef PNG_pHYs_SUPPORTED
+PNG_EXPORT(150, void, png_set_pHYs,
+    (png_structp png_ptr, png_infop info_ptr,
+    png_uint_32 res_x, png_uint_32 res_y, int unit_type));
+#endif
+PNG_EXPORT(151, png_uint_32, png_get_PLTE,
+    (png_const_structp png_ptr, png_const_infop info_ptr,
+    png_colorp *palette, int *num_palette));
+PNG_EXPORT(152, void, png_set_PLTE,
+    (png_structp png_ptr, png_infop info_ptr,
+    png_const_colorp palette, int num_palette));
+#ifdef PNG_sBIT_SUPPORTED
+PNG_EXPORT(153, png_uint_32, png_get_sBIT,
+    (png_const_structp png_ptr, png_infop info_ptr,
+    png_color_8p *sig_bit));
+#endif
+#ifdef PNG_sBIT_SUPPORTED
+PNG_EXPORT(154, void, png_set_sBIT,
+    (png_structp png_ptr, png_infop info_ptr, png_const_color_8p sig_bit));
+#endif
+#ifdef PNG_sRGB_SUPPORTED
+PNG_EXPORT(155, png_uint_32, png_get_sRGB, (png_const_structp png_ptr,
+    png_const_infop info_ptr, int *file_srgb_intent));
+#endif
+#ifdef PNG_sRGB_SUPPORTED
+PNG_EXPORT(156, void, png_set_sRGB,
+    (png_structp png_ptr, png_infop info_ptr, int srgb_intent));
+PNG_EXPORT(157, void, png_set_sRGB_gAMA_and_cHRM, (png_structp png_ptr,
+    png_infop info_ptr, int srgb_intent));
+#endif
+#ifdef PNG_iCCP_SUPPORTED
+PNG_EXPORT(158, png_uint_32, png_get_iCCP,
+    (png_const_structp png_ptr, png_const_infop info_ptr,
+    png_charpp name, int *compression_type, png_bytepp profile,
+    png_uint_32 *proflen));
+#endif
+#ifdef PNG_iCCP_SUPPORTED
+PNG_EXPORT(159, void, png_set_iCCP,
+    (png_structp png_ptr, png_infop info_ptr,
+    png_const_charp name, int compression_type, png_const_bytep profile,
+    png_uint_32 proflen));
+#endif
+#ifdef PNG_sPLT_SUPPORTED
+PNG_EXPORT(160, png_uint_32, png_get_sPLT,
+    (png_const_structp png_ptr, png_const_infop info_ptr,
+    png_sPLT_tpp entries));
+#endif
+#ifdef PNG_sPLT_SUPPORTED
+PNG_EXPORT(161, void, png_set_sPLT,
+    (png_structp png_ptr, png_infop info_ptr,
+    png_const_sPLT_tp entries, int nentries));
+#endif
+#ifdef PNG_TEXT_SUPPORTED
+/* png_get_text also returns the number of text chunks in *num_text */
+PNG_EXPORT(162, png_uint_32, png_get_text,
+    (png_const_structp png_ptr, png_const_infop info_ptr,
+    png_textp *text_ptr, int *num_text));
+#endif
+/* Note while png_set_text() will accept a structure whose text,
+ * language, and  translated keywords are NULL pointers, the structure
+ * returned by png_get_text will always contain regular
+ * zero-terminated C strings.  They might be empty strings but
+ * they will never be NULL pointers.
+ */
+#ifdef PNG_TEXT_SUPPORTED
+PNG_EXPORT(163, void, png_set_text,
+    (png_structp png_ptr, png_infop info_ptr,
+    png_const_textp text_ptr, int num_text));
+#endif
+#ifdef PNG_tIME_SUPPORTED
+PNG_EXPORT(164, png_uint_32, png_get_tIME,
+    (png_const_structp png_ptr, png_infop info_ptr, png_timep *mod_time));
+#endif
+#ifdef PNG_tIME_SUPPORTED
+PNG_EXPORT(165, void, png_set_tIME,
+    (png_structp png_ptr, png_infop info_ptr, png_const_timep mod_time));
+#endif
+#ifdef PNG_tRNS_SUPPORTED
+PNG_EXPORT(166, png_uint_32, png_get_tRNS,
+    (png_const_structp png_ptr, png_infop info_ptr,
+    png_bytep *trans_alpha, int *num_trans, png_color_16p *trans_color));
+#endif
+#ifdef PNG_tRNS_SUPPORTED
+PNG_EXPORT(167, void, png_set_tRNS,
+    (png_structp png_ptr, png_infop info_ptr,
+    png_const_bytep trans_alpha, int num_trans,
+    png_const_color_16p trans_color));
+#endif
+#ifdef PNG_sCAL_SUPPORTED
+PNG_FP_EXPORT(168, png_uint_32, png_get_sCAL,
+    (png_const_structp png_ptr, png_const_infop info_ptr,
+    int *unit, double *width, double *height));
+#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
+/* NOTE: this API is currently implemented using floating point arithmetic,
+ * consequently it can only be used on systems with floating point support.
+ * In any case the range of values supported by png_fixed_point is small and it
+ * is highly recommended that png_get_sCAL_s be used instead.
+ */
+PNG_FIXED_EXPORT(214, png_uint_32, png_get_sCAL_fixed,
+    (png_structp png_ptr, png_const_infop info_ptr, int *unit,
+    png_fixed_point *width,
+    png_fixed_point *height));
+#endif
+PNG_EXPORT(169, png_uint_32, png_get_sCAL_s,
+    (png_const_structp png_ptr, png_const_infop info_ptr,
+    int *unit, png_charpp swidth, png_charpp sheight));
+PNG_FP_EXPORT(170, void, png_set_sCAL,
+    (png_structp png_ptr, png_infop info_ptr,
+    int unit, double width, double height));
+PNG_FIXED_EXPORT(213, void, png_set_sCAL_fixed, (png_structp png_ptr,
+   png_infop info_ptr, int unit, png_fixed_point width,
+   png_fixed_point height));
+PNG_EXPORT(171, void, png_set_sCAL_s,
+    (png_structp png_ptr, png_infop info_ptr,
+    int unit, png_const_charp swidth, png_const_charp sheight));
+#endif /* PNG_sCAL_SUPPORTED */
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+/* Provide a list of chunks and how they are to be handled, if the built-in
+   handling or default unknown chunk handling is not desired.  Any chunks not
+   listed will be handled in the default manner.  The IHDR and IEND chunks
+   must not be listed.  Because this turns off the default handling for chunks
+   that would otherwise be recognized the behavior of libpng transformations may
+   well become incorrect!
+      keep = 0: PNG_HANDLE_CHUNK_AS_DEFAULT: follow default behavior
+           = 1: PNG_HANDLE_CHUNK_NEVER:      do not keep
+           = 2: PNG_HANDLE_CHUNK_IF_SAFE:    keep only if safe-to-copy
+           = 3: PNG_HANDLE_CHUNK_ALWAYS:     keep even if unsafe-to-copy
+*/
+PNG_EXPORT(172, void, png_set_keep_unknown_chunks,
+    (png_structp png_ptr, int keep,
+    png_const_bytep chunk_list, int num_chunks));
+/* The handling code is returned; the result is therefore true (non-zero) if
+ * special handling is required, false for the default handling.
+ */
+PNG_EXPORT(173, int, png_handle_as_unknown, (png_structp png_ptr,
+    png_const_bytep chunk_name));
+#endif
+#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
+PNG_EXPORT(174, void, png_set_unknown_chunks, (png_structp png_ptr,
+    png_infop info_ptr, png_const_unknown_chunkp unknowns,
+    int num_unknowns));
+PNG_EXPORT(175, void, png_set_unknown_chunk_location,
+    (png_structp png_ptr, png_infop info_ptr, int chunk, int location));
+PNG_EXPORT(176, int, png_get_unknown_chunks, (png_const_structp png_ptr,
+    png_const_infop info_ptr, png_unknown_chunkpp entries));
+#endif
+/* Png_free_data() will turn off the "valid" flag for anything it frees.
+ * If you need to turn it off for a chunk that your application has freed,
+ * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK);
+ */
+PNG_EXPORT(177, void, png_set_invalid,
+    (png_structp png_ptr, png_infop info_ptr, int mask));
+#ifdef PNG_INFO_IMAGE_SUPPORTED
+/* The "params" pointer is currently not used and is for future expansion. */
+PNG_EXPORT(178, void, png_read_png, (png_structp png_ptr, png_infop info_ptr,
+    int transforms, png_voidp params));
+PNG_EXPORT(179, void, png_write_png, (png_structp png_ptr, png_infop info_ptr,
+    int transforms, png_voidp params));
+#endif
+PNG_EXPORT(180, png_const_charp, png_get_copyright,
+    (png_const_structp png_ptr));
+PNG_EXPORT(181, png_const_charp, png_get_header_ver,
+    (png_const_structp png_ptr));
+PNG_EXPORT(182, png_const_charp, png_get_header_version,
+    (png_const_structp png_ptr));
+PNG_EXPORT(183, png_const_charp, png_get_libpng_ver,
+    (png_const_structp png_ptr));
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+PNG_EXPORT(184, png_uint_32, png_permit_mng_features, (png_structp png_ptr,
+    png_uint_32 mng_features_permitted));
+#endif
+/* For use in png_set_keep_unknown, added to version 1.2.6 */
+#define PNG_HANDLE_CHUNK_AS_DEFAULT   0
+#define PNG_HANDLE_CHUNK_NEVER        1
+#define PNG_HANDLE_CHUNK_IF_SAFE      2
+#define PNG_HANDLE_CHUNK_ALWAYS       3
+/* Strip the prepended error numbers ("#nnn ") from error and warning
+ * messages before passing them to the error or warning handler.
+ */
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+PNG_EXPORT(185, void, png_set_strip_error_numbers,
+    (png_structp png_ptr,
+    png_uint_32 strip_mode));
+#endif
+/* Added in libpng-1.2.6 */
+#ifdef PNG_SET_USER_LIMITS_SUPPORTED
+PNG_EXPORT(186, void, png_set_user_limits, (png_structp png_ptr,
+    png_uint_32 user_width_max, png_uint_32 user_height_max));
+PNG_EXPORT(187, png_uint_32, png_get_user_width_max,
+    (png_const_structp png_ptr));
+PNG_EXPORT(188, png_uint_32, png_get_user_height_max,
+    (png_const_structp png_ptr));
+/* Added in libpng-1.4.0 */
+PNG_EXPORT(189, void, png_set_chunk_cache_max, (png_structp png_ptr,
+    png_uint_32 user_chunk_cache_max));
+PNG_EXPORT(190, png_uint_32, png_get_chunk_cache_max,
+    (png_const_structp png_ptr));
+/* Added in libpng-1.4.1 */
+PNG_EXPORT(191, void, png_set_chunk_malloc_max, (png_structp png_ptr,
+    png_alloc_size_t user_chunk_cache_max));
+PNG_EXPORT(192, png_alloc_size_t, png_get_chunk_malloc_max,
+    (png_const_structp png_ptr));
+#endif
+#if defined(PNG_INCH_CONVERSIONS_SUPPORTED)
+PNG_EXPORT(193, png_uint_32, png_get_pixels_per_inch,
+    (png_const_structp png_ptr, png_const_infop info_ptr));
+PNG_EXPORT(194, png_uint_32, png_get_x_pixels_per_inch,
+    (png_const_structp png_ptr, png_const_infop info_ptr));
+PNG_EXPORT(195, png_uint_32, png_get_y_pixels_per_inch,
+    (png_const_structp png_ptr, png_const_infop info_ptr));
+PNG_FP_EXPORT(196, float, png_get_x_offset_inches,
+    (png_const_structp png_ptr, png_const_infop info_ptr));
+#ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */
+PNG_FIXED_EXPORT(211, png_fixed_point, png_get_x_offset_inches_fixed,
+    (png_structp png_ptr, png_const_infop info_ptr));
+#endif
+PNG_FP_EXPORT(197, float, png_get_y_offset_inches, (png_const_structp png_ptr,
+    png_const_infop info_ptr));
+#ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */
+PNG_FIXED_EXPORT(212, png_fixed_point, png_get_y_offset_inches_fixed,
+    (png_structp png_ptr, png_const_infop info_ptr));
+#endif
+#  ifdef PNG_pHYs_SUPPORTED
+PNG_EXPORT(198, png_uint_32, png_get_pHYs_dpi, (png_const_structp png_ptr,
+    png_const_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y,
+    int *unit_type));
+#  endif /* PNG_pHYs_SUPPORTED */
+#endif  /* PNG_INCH_CONVERSIONS_SUPPORTED */
+/* Added in libpng-1.4.0 */
+#ifdef PNG_IO_STATE_SUPPORTED
+PNG_EXPORT(199, png_uint_32, png_get_io_state, (png_structp png_ptr));
+PNG_EXPORTA(200, png_const_bytep, png_get_io_chunk_name,
+    (png_structp png_ptr), PNG_DEPRECATED);
+PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type,
+    (png_const_structp png_ptr));
+/* The flags returned by png_get_io_state() are the following: */
+#  define PNG_IO_NONE        0x0000   /* no I/O at this moment */
+#  define PNG_IO_READING     0x0001   /* currently reading */
+#  define PNG_IO_WRITING     0x0002   /* currently writing */
+#  define PNG_IO_SIGNATURE   0x0010   /* currently at the file signature */
+#  define PNG_IO_CHUNK_HDR   0x0020   /* currently at the chunk header */
+#  define PNG_IO_CHUNK_DATA  0x0040   /* currently at the chunk data */
+#  define PNG_IO_CHUNK_CRC   0x0080   /* currently at the chunk crc */
+#  define PNG_IO_MASK_OP     0x000f   /* current operation: reading/writing */
+#  define PNG_IO_MASK_LOC    0x00f0   /* current location: sig/hdr/data/crc */
+#endif /* ?PNG_IO_STATE_SUPPORTED */
+/* Interlace support.  The following macros are always defined so that if
+ * libpng interlace handling is turned off the macros may be used to handle
+ * interlaced images within the application.
+ */
+#define PNG_INTERLACE_ADAM7_PASSES 7
+/* Two macros to return the first row and first column of the original,
+ * full, image which appears in a given pass.  'pass' is in the range 0
+ * to 6 and the result is in the range 0 to 7.
+ */
+#define PNG_PASS_START_ROW(pass) (((1&~(pass))<<(3-((pass)>>1)))&7)
+#define PNG_PASS_START_COL(pass) (((1& (pass))<<(3-(((pass)+1)>>1)))&7)
+/* A macro to return the offset between pixels in the output row for a pair of
+ * pixels in the input - effectively the inverse of the 'COL_SHIFT' macro that
+ * follows.  Note that ROW_OFFSET is the offset from one row to the next whereas
+ * COL_OFFSET is from one column to the next, within a row.
+ */
+#define PNG_PASS_ROW_OFFSET(pass) ((pass)>2?(8>>(((pass)-1)>>1)):8)
+#define PNG_PASS_COL_OFFSET(pass) (1<<((7-(pass))>>1))
+/* Two macros to help evaluate the number of rows or columns in each
+ * pass.  This is expressed as a shift - effectively log2 of the number or
+ * rows or columns in each 8x8 tile of the original image.
+ */
+#define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3)
+#define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3)
+/* Hence two macros to determine the number of rows or columns in a given
+ * pass of an image given its height or width.  In fact these macros may
+ * return non-zero even though the sub-image is empty, because the other
+ * dimension may be empty for a small image.
+ */
+#define PNG_PASS_ROWS(height, pass) (((height)+(((1<<PNG_PASS_ROW_SHIFT(pass))\
+   -1)-PNG_PASS_START_ROW(pass)))>>PNG_PASS_ROW_SHIFT(pass))
+#define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\
+   -1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass))
+/* For the reader row callbacks (both progressive and sequential) it is
+ * necessary to find the row in the output image given a row in an interlaced
+ * image, so two more macros:
+ */
+#define PNG_ROW_FROM_PASS_ROW(yIn, pass) \
+   (((yIn)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass))
+#define PNG_COL_FROM_PASS_COL(xIn, pass) \
+   (((xIn)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass))
+/* Two macros which return a boolean (0 or 1) saying whether the given row
+ * or column is in a particular pass.  These use a common utility macro that
+ * returns a mask for a given pass - the offset 'off' selects the row or
+ * column version.  The mask has the appropriate bit set for each column in
+ * the tile.
+ */
+#define PNG_PASS_MASK(pass,off) ( \
+   ((0x110145AF>>(((7-(off))-(pass))<<2)) & 0xF) | \
+   ((0x01145AF0>>(((7-(off))-(pass))<<2)) & 0xF0))
+#define PNG_ROW_IN_INTERLACE_PASS(y, pass) \
+   ((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1)
+#define PNG_COL_IN_INTERLACE_PASS(x, pass) \
+   ((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1)
+#ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
+/* With these routines we avoid an integer divide, which will be slower on
+ * most machines.  However, it does take more operations than the corresponding
+ * divide method, so it may be slower on a few RISC systems.  There are two
+ * shifts (by 8 or 16 bits) and an addition, versus a single integer divide.
+ *
+ * Note that the rounding factors are NOT supposed to be the same!  128 and
+ * 32768 are correct for the NODIV code; 127 and 32767 are correct for the
+ * standard method.
+ *
+ * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
+ */
+ /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */
+#  define png_composite(composite, fg, alpha, bg)         \
+     { png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \
+           * (png_uint_16)(alpha)                         \
+           + (png_uint_16)(bg)*(png_uint_16)(255          \
+           - (png_uint_16)(alpha)) + 128);                \
+       (composite) = (png_byte)((temp + (temp >> 8)) >> 8); }
+#  define png_composite_16(composite, fg, alpha, bg)       \
+     { png_uint_32 temp = (png_uint_32)((png_uint_32)(fg)  \
+           * (png_uint_32)(alpha)                          \
+           + (png_uint_32)(bg)*(65535                      \
+           - (png_uint_32)(alpha)) + 32768);               \
+       (composite) = (png_uint_16)((temp + (temp >> 16)) >> 16); }
+#else  /* Standard method using integer division */
+#  define png_composite(composite, fg, alpha, bg)                          \
+     (composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) +  \
+     (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) +       \
+     127) / 255)
+#  define png_composite_16(composite, fg, alpha, bg)                         \
+     (composite) = (png_uint_16)(((png_uint_32)(fg) * (png_uint_32)(alpha) + \
+     (png_uint_32)(bg)*(png_uint_32)(65535 - (png_uint_32)(alpha)) +         \
+     32767) / 65535)
+#endif /* PNG_READ_COMPOSITE_NODIV_SUPPORTED */
+#ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED
+PNG_EXPORT(201, png_uint_32, png_get_uint_32, (png_const_bytep buf));
+PNG_EXPORT(202, png_uint_16, png_get_uint_16, (png_const_bytep buf));
+PNG_EXPORT(203, png_int_32, png_get_int_32, (png_const_bytep buf));
+#endif
+PNG_EXPORT(204, png_uint_32, png_get_uint_31, (png_structp png_ptr,
+    png_const_bytep buf));
+/* No png_get_int_16 -- may be added if there's a real need for it. */
+/* Place a 32-bit number into a buffer in PNG byte order (big-endian). */
+#ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
+PNG_EXPORT(205, void, png_save_uint_32, (png_bytep buf, png_uint_32 i));
+#endif
+#ifdef PNG_SAVE_INT_32_SUPPORTED
+PNG_EXPORT(206, void, png_save_int_32, (png_bytep buf, png_int_32 i));
+#endif
+/* Place a 16-bit number into a buffer in PNG byte order.
+ * The parameter is declared unsigned int, not png_uint_16,
+ * just to avoid potential problems on pre-ANSI C compilers.
+ */
+#ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
+PNG_EXPORT(207, void, png_save_uint_16, (png_bytep buf, unsigned int i));
+/* No png_save_int_16 -- may be added if there's a real need for it. */
+#endif
+#ifdef PNG_USE_READ_MACROS
+/* Inline macros to do direct reads of bytes from the input buffer.
+ * The png_get_int_32() routine assumes we are using two's complement
+ * format for negative values, which is almost certainly true.
+ */
+#  define png_get_uint_32(buf) \
+     (((png_uint_32)(*(buf)) << 24) + \
+      ((png_uint_32)(*((buf) + 1)) << 16) + \
+      ((png_uint_32)(*((buf) + 2)) << 8) + \
+      ((png_uint_32)(*((buf) + 3))))
+   /* From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the
+    * function) incorrectly returned a value of type png_uint_32.
+    */
+#  define png_get_uint_16(buf) \
+     ((png_uint_16) \
+      (((unsigned int)(*(buf)) << 8) + \
+       ((unsigned int)(*((buf) + 1)))))
+#  define png_get_int_32(buf) \
+     ((png_int_32)((*(buf) & 0x80) \
+      ? -((png_int_32)((png_get_uint_32(buf) ^ 0xffffffffL) + 1)) \
+      : (png_int_32)png_get_uint_32(buf)))
+#endif
+/* Maintainer: Put new public prototypes here ^, in libpng.3, and project
+ * defs
+ */
+/* The last ordinal number (this is the *last* one already used; the next
+ * one to use is one more than this.)  Maintainer, remember to add an entry to
+ * scripts/symbols.def as well.
+ */
+#ifdef PNG_EXPORT_LAST_ORDINAL
+  PNG_EXPORT_LAST_ORDINAL(233);
+#endif
+#ifdef __cplusplus
+}
+#endif
+#endif /* PNG_VERSION_INFO_ONLY */
+/* Do not put anything past this line */
+#endif /* PNG_H */
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngbar.jpg b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngbar.jpg
new file mode 100644
index 0000000..70ba8d8
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngbar.jpg
Binary files differ
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngbar.png b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngbar.png
new file mode 100644
index 0000000..49798c8
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngbar.png
Binary files differ
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngconf.h b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngconf.h
new file mode 100644
index 0000000..3fea47b
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngconf.h
@@ -0,0 +1,596 @@
+/* pngconf.h - machine configurable file for libpng
+ *
+ * libpng version 1.5.9 - February 18, 2012
+ *
+ * Copyright (c) 1998-2012 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ */
+/* Any machine specific code is near the front of this file, so if you
+ * are configuring libpng for a machine, you may want to read the section
+ * starting here down to where it starts to typedef png_color, png_text,
+ * and png_info.
+ */
+#ifndef PNGCONF_H
+#define PNGCONF_H
+#ifndef PNG_BUILDING_SYMBOL_TABLE
+/* PNG_NO_LIMITS_H may be used to turn off the use of the standard C
+ * definition file for  machine specific limits, this may impact the
+ * correctness of the definitons below (see uses of INT_MAX).
+ */
+#  ifndef PNG_NO_LIMITS_H
+#    include <limits.h>
+#  endif
+/* For the memory copy APIs (i.e. the standard definitions of these),
+ * because this file defines png_memcpy and so on the base APIs must
+ * be defined here.
+ */
+#  ifdef BSD
+#    include <strings.h>
+#  else
+#    include <string.h>
+#  endif
+/* For png_FILE_p - this provides the standard definition of a
+ * FILE
+ */
+#  ifdef PNG_STDIO_SUPPORTED
+#    include <stdio.h>
+#  endif
+#endif
+/* This controls optimization of the reading of 16 and 32 bit values
+ * from PNG files.  It can be set on a per-app-file basis - it
+ * just changes whether a macro is used to the function is called.
+ * The library builder sets the default, if read functions are not
+ * built into the library the macro implementation is forced on.
+ */
+#ifndef PNG_READ_INT_FUNCTIONS_SUPPORTED
+#  define PNG_USE_READ_MACROS
+#endif
+#if !defined(PNG_NO_USE_READ_MACROS) && !defined(PNG_USE_READ_MACROS)
+#  if PNG_DEFAULT_READ_MACROS
+#    define PNG_USE_READ_MACROS
+#  endif
+#endif
+/* COMPILER SPECIFIC OPTIONS.
+ *
+ * These options are provided so that a variety of difficult compilers
+ * can be used.  Some are fixed at build time (e.g. PNG_API_RULE
+ * below) but still have compiler specific implementations, others
+ * may be changed on a per-file basis when compiling against libpng.
+ */
+/* The PNGARG macro protects us against machines that don't have function
+ * prototypes (ie K&R style headers).  If your compiler does not handle
+ * function prototypes, define this macro and use the included ansi2knr.
+ * I've always been able to use _NO_PROTO as the indicator, but you may
+ * need to drag the empty declaration out in front of here, or change the
+ * ifdef to suit your own needs.
+ */
+#ifndef PNGARG
+#  ifdef OF /* zlib prototype munger */
+#    define PNGARG(arglist) OF(arglist)
+#  else
+#    ifdef _NO_PROTO
+#      define PNGARG(arglist) ()
+#    else
+#      define PNGARG(arglist) arglist
+#    endif /* _NO_PROTO */
+#  endif /* OF */
+#endif /* PNGARG */
+/* Function calling conventions.
+ * =============================
+ * Normally it is not necessary to specify to the compiler how to call
+ * a function - it just does it - however on x86 systems derived from
+ * Microsoft and Borland C compilers ('IBM PC', 'DOS', 'Windows' systems
+ * and some others) there are multiple ways to call a function and the
+ * default can be changed on the compiler command line.  For this reason
+ * libpng specifies the calling convention of every exported function and
+ * every function called via a user supplied function pointer.  This is
+ * done in this file by defining the following macros:
+ *
+ * PNGAPI    Calling convention for exported functions.
+ * PNGCBAPI  Calling convention for user provided (callback) functions.
+ * PNGCAPI   Calling convention used by the ANSI-C library (required
+ *           for longjmp callbacks and sometimes used internally to
+ *           specify the calling convention for zlib).
+ *
+ * These macros should never be overridden.  If it is necessary to
+ * change calling convention in a private build this can be done
+ * by setting PNG_API_RULE (which defaults to 0) to one of the values
+ * below to select the correct 'API' variants.
+ *
+ * PNG_API_RULE=0 Use PNGCAPI - the 'C' calling convention - throughout.
+ *                This is correct in every known environment.
+ * PNG_API_RULE=1 Use the operating system convention for PNGAPI and
+ *                the 'C' calling convention (from PNGCAPI) for
+ *                callbacks (PNGCBAPI).  This is no longer required
+ *                in any known environment - if it has to be used
+ *                please post an explanation of the problem to the
+ *                libpng mailing list.
+ *
+ * These cases only differ if the operating system does not use the C
+ * calling convention, at present this just means the above cases
+ * (x86 DOS/Windows sytems) and, even then, this does not apply to
+ * Cygwin running on those systems.
+ *
+ * Note that the value must be defined in pnglibconf.h so that what
+ * the application uses to call the library matches the conventions
+ * set when building the library.
+ */
+/* Symbol export
+ * =============
+ * When building a shared library it is almost always necessary to tell
+ * the compiler which symbols to export.  The png.h macro 'PNG_EXPORT'
+ * is used to mark the symbols.  On some systems these symbols can be
+ * extracted at link time and need no special processing by the compiler,
+ * on other systems the symbols are flagged by the compiler and just
+ * the declaration requires a special tag applied (unfortunately) in a
+ * compiler dependent way.  Some systems can do either.
+ *
+ * A small number of older systems also require a symbol from a DLL to
+ * be flagged to the program that calls it.  This is a problem because
+ * we do not know in the header file included by application code that
+ * the symbol will come from a shared library, as opposed to a statically
+ * linked one.  For this reason the application must tell us by setting
+ * the magic flag PNG_USE_DLL to turn on the special processing before
+ * it includes png.h.
+ *
+ * Four additional macros are used to make this happen:
+ *
+ * PNG_IMPEXP The magic (if any) to cause a symbol to be exported from
+ *            the build or imported if PNG_USE_DLL is set - compiler
+ *            and system specific.
+ *
+ * PNG_EXPORT_TYPE(type) A macro that pre or appends PNG_IMPEXP to
+ *                       'type', compiler specific.
+ *
+ * PNG_DLL_EXPORT Set to the magic to use during a libpng build to
+ *                make a symbol exported from the DLL.  Not used in the
+ *                public header files; see pngpriv.h for how it is used
+ *                in the libpng build.
+ *
+ * PNG_DLL_IMPORT Set to the magic to force the libpng symbols to come
+ *                from a DLL - used to define PNG_IMPEXP when
+ *                PNG_USE_DLL is set.
+ */
+/* System specific discovery.
+ * ==========================
+ * This code is used at build time to find PNG_IMPEXP, the API settings
+ * and PNG_EXPORT_TYPE(), it may also set a macro to indicate the DLL
+ * import processing is possible.  On Windows/x86 systems it also sets
+ * compiler-specific macros to the values required to change the calling
+ * conventions of the various functions.
+ */
+#if ( defined(_Windows) || defined(_WINDOWS) || defined(WIN32) ||\
+      defined(_WIN32) || defined(__WIN32__) || defined(__CYGWIN__) ) &&\
+    ( defined(_X86_) || defined(_X64_) || defined(_M_IX86) ||\
+      defined(_M_X64) || defined(_M_IA64) )
+  /* Windows system (DOS doesn't support DLLs) running on x86/x64.  Includes
+   * builds under Cygwin or MinGW.  Also includes Watcom builds but these need
+   * special treatment because they are not compatible with GCC or Visual C
+   * because of different calling conventions.
+   */
+#  if PNG_API_RULE == 2
+    /* If this line results in an error, either because __watcall is not
+     * understood or because of a redefine just below you cannot use *this*
+     * build of the library with the compiler you are using.  *This* build was
+     * build using Watcom and applications must also be built using Watcom!
+     */
+#    define PNGCAPI __watcall
+#  endif
+#  if defined(__GNUC__) || (defined (_MSC_VER) && (_MSC_VER >= 800))
+#    define PNGCAPI __cdecl
+#    if PNG_API_RULE == 1
+#      define PNGAPI __stdcall
+#    endif
+#  else
+    /* An older compiler, or one not detected (erroneously) above,
+     * if necessary override on the command line to get the correct
+     * variants for the compiler.
+     */
+#    ifndef PNGCAPI
+#      define PNGCAPI _cdecl
+#    endif
+#    if PNG_API_RULE == 1 && !defined(PNGAPI)
+#      define PNGAPI _stdcall
+#    endif
+#  endif /* compiler/api */
+  /* NOTE: PNGCBAPI always defaults to PNGCAPI. */
+#  if defined(PNGAPI) && !defined(PNG_USER_PRIVATEBUILD)
+   ERROR: PNG_USER_PRIVATEBUILD must be defined if PNGAPI is changed
+#  endif
+#  if (defined(_MSC_VER) && _MSC_VER < 800) ||\
+      (defined(__BORLANDC__) && __BORLANDC__ < 0x500)
+    /* older Borland and MSC
+     * compilers used '__export' and required this to be after
+     * the type.
+     */
+#    ifndef PNG_EXPORT_TYPE
+#      define PNG_EXPORT_TYPE(type) type PNG_IMPEXP
+#    endif
+#    define PNG_DLL_EXPORT __export
+#  else /* newer compiler */
+#    define PNG_DLL_EXPORT __declspec(dllexport)
+#    ifndef PNG_DLL_IMPORT
+#      define PNG_DLL_IMPORT __declspec(dllimport)
+#    endif
+#  endif /* compiler */
+#else /* !Windows/x86 */
+#  if (defined(__IBMC__) || defined(__IBMCPP__)) && defined(__OS2__)
+#    define PNGAPI _System
+#  else /* !Windows/x86 && !OS/2 */
+    /* Use the defaults, or define PNG*API on the command line (but
+     * this will have to be done for every compile!)
+     */
+#  endif /* other system, !OS/2 */
+#endif /* !Windows/x86 */
+/* Now do all the defaulting . */
+#ifndef PNGCAPI
+#  define PNGCAPI
+#endif
+#ifndef PNGCBAPI
+#  define PNGCBAPI PNGCAPI
+#endif
+#ifndef PNGAPI
+#  define PNGAPI PNGCAPI
+#endif
+/* PNG_IMPEXP may be set on the compilation system command line or (if not set)
+ * then in an internal header file when building the library, otherwise (when
+ * using the library) it is set here.
+ */
+#ifndef PNG_IMPEXP
+#  if defined(PNG_USE_DLL) && defined(PNG_DLL_IMPORT)
+     /* This forces use of a DLL, disallowing static linking */
+#    define PNG_IMPEXP PNG_DLL_IMPORT
+#  endif
+#  ifndef PNG_IMPEXP
+#    define PNG_IMPEXP
+#  endif
+#endif
+/* In 1.5.2 the definition of PNG_FUNCTION has been changed to always treat
+ * 'attributes' as a storage class - the attributes go at the start of the
+ * function definition, and attributes are always appended regardless of the
+ * compiler.  This considerably simplifies these macros but may cause problems
+ * if any compilers both need function attributes and fail to handle them as
+ * a storage class (this is unlikely.)
+ */
+#ifndef PNG_FUNCTION
+#  define PNG_FUNCTION(type, name, args, attributes) attributes type name args
+#endif
+#ifndef PNG_EXPORT_TYPE
+#  define PNG_EXPORT_TYPE(type) PNG_IMPEXP type
+#endif
+   /* The ordinal value is only relevant when preprocessing png.h for symbol
+    * table entries, so we discard it here.  See the .dfn files in the
+    * scripts directory.
+    */
+#ifndef PNG_EXPORTA
+#  define PNG_EXPORTA(ordinal, type, name, args, attributes)\
+      PNG_FUNCTION(PNG_EXPORT_TYPE(type),(PNGAPI name),PNGARG(args), \
+        extern attributes)
+#endif
+/* ANSI-C (C90) does not permit a macro to be invoked with an empty argument,
+ * so make something non-empty to satisfy the requirement:
+ */
+#define PNG_EMPTY /*empty list*/
+#define PNG_EXPORT(ordinal, type, name, args)\
+   PNG_EXPORTA(ordinal, type, name, args, PNG_EMPTY)
+/* Use PNG_REMOVED to comment out a removed interface. */
+#ifndef PNG_REMOVED
+#  define PNG_REMOVED(ordinal, type, name, args, attributes)
+#endif
+#ifndef PNG_CALLBACK
+#  define PNG_CALLBACK(type, name, args) type (PNGCBAPI name) PNGARG(args)
+#endif
+/* Support for compiler specific function attributes.  These are used
+ * so that where compiler support is available incorrect use of API
+ * functions in png.h will generate compiler warnings.
+ *
+ * Added at libpng-1.2.41.
+ */
+#ifndef PNG_NO_PEDANTIC_WARNINGS
+#  ifndef PNG_PEDANTIC_WARNINGS_SUPPORTED
+#    define PNG_PEDANTIC_WARNINGS_SUPPORTED
+#  endif
+#endif
+#ifdef PNG_PEDANTIC_WARNINGS_SUPPORTED
+  /* Support for compiler specific function attributes.  These are used
+   * so that where compiler support is available incorrect use of API
+   * functions in png.h will generate compiler warnings.  Added at libpng
+   * version 1.2.41.
+   */
+#  if defined(__GNUC__)
+#    ifndef PNG_USE_RESULT
+#      define PNG_USE_RESULT __attribute__((__warn_unused_result__))
+#    endif
+#    ifndef PNG_NORETURN
+#      define PNG_NORETURN   __attribute__((__noreturn__))
+#    endif
+#    ifndef PNG_ALLOCATED
+#      define PNG_ALLOCATED  __attribute__((__malloc__))
+#    endif
+#    ifndef PNG_DEPRECATED
+#      define PNG_DEPRECATED __attribute__((__deprecated__))
+#    endif
+#    ifndef PNG_PRIVATE
+#      if 0 /* Doesn't work so we use deprecated instead*/
+#        define PNG_PRIVATE \
+          __attribute__((warning("This function is not exported by libpng.")))
+#      else
+#        define PNG_PRIVATE \
+          __attribute__((__deprecated__))
+#      endif
+#    endif
+#  endif /* __GNUC__ */
+#  if defined(_MSC_VER)  && (_MSC_VER >= 1300)
+#    ifndef PNG_USE_RESULT
+#      define PNG_USE_RESULT /* not supported */
+#    endif
+#    ifndef PNG_NORETURN
+#      define PNG_NORETURN __declspec(noreturn)
+#    endif
+#    ifndef PNG_ALLOCATED
+#      if (_MSC_VER >= 1400)
+#        define PNG_ALLOCATED __declspec(restrict)
+#      endif
+#    endif
+#    ifndef PNG_DEPRECATED
+#      define PNG_DEPRECATED __declspec(deprecated)
+#    endif
+#    ifndef PNG_PRIVATE
+#      define PNG_PRIVATE __declspec(deprecated)
+#    endif
+#  endif /* _MSC_VER */
+#endif /* PNG_PEDANTIC_WARNINGS */
+#ifndef PNG_DEPRECATED
+#  define PNG_DEPRECATED  /* Use of this function is deprecated */
+#endif
+#ifndef PNG_USE_RESULT
+#  define PNG_USE_RESULT  /* The result of this function must be checked */
+#endif
+#ifndef PNG_NORETURN
+#  define PNG_NORETURN    /* This function does not return */
+#endif
+#ifndef PNG_ALLOCATED
+#  define PNG_ALLOCATED   /* The result of the function is new memory */
+#endif
+#ifndef PNG_PRIVATE
+#  define PNG_PRIVATE     /* This is a private libpng function */
+#endif
+#ifndef PNG_FP_EXPORT     /* A floating point API. */
+#  ifdef PNG_FLOATING_POINT_SUPPORTED
+#     define PNG_FP_EXPORT(ordinal, type, name, args)\
+         PNG_EXPORT(ordinal, type, name, args)
+#  else                   /* No floating point APIs */
+#     define PNG_FP_EXPORT(ordinal, type, name, args)
+#  endif
+#endif
+#ifndef PNG_FIXED_EXPORT  /* A fixed point API. */
+#  ifdef PNG_FIXED_POINT_SUPPORTED
+#     define PNG_FIXED_EXPORT(ordinal, type, name, args)\
+         PNG_EXPORT(ordinal, type, name, args)
+#  else                   /* No fixed point APIs */
+#     define PNG_FIXED_EXPORT(ordinal, type, name, args)
+#  endif
+#endif
+/* The following uses const char * instead of char * for error
+ * and warning message functions, so some compilers won't complain.
+ * If you do not want to use const, define PNG_NO_CONST here.
+ *
+ * This should not change how the APIs are called, so it can be done
+ * on a per-file basis in the application.
+ */
+#ifndef PNG_CONST
+#  ifndef PNG_NO_CONST
+#    define PNG_CONST const
+#  else
+#    define PNG_CONST
+#  endif
+#endif
+/* Some typedefs to get us started.  These should be safe on most of the
+ * common platforms.  The typedefs should be at least as large as the
+ * numbers suggest (a png_uint_32 must be at least 32 bits long), but they
+ * don't have to be exactly that size.  Some compilers dislike passing
+ * unsigned shorts as function parameters, so you may be better off using
+ * unsigned int for png_uint_16.
+ */
+#if defined(INT_MAX) && (INT_MAX > 0x7ffffffeL)
+typedef unsigned int png_uint_32;
+typedef int png_int_32;
+#else
+typedef unsigned long png_uint_32;
+typedef long png_int_32;
+#endif
+typedef unsigned short png_uint_16;
+typedef short png_int_16;
+typedef unsigned char png_byte;
+#ifdef PNG_NO_SIZE_T
+typedef unsigned int png_size_t;
+#else
+typedef size_t png_size_t;
+#endif
+#define png_sizeof(x) (sizeof (x))
+/* The following is needed for medium model support.  It cannot be in the
+ * pngpriv.h header.  Needs modification for other compilers besides
+ * MSC.  Model independent support declares all arrays and pointers to be
+ * large using the far keyword.  The zlib version used must also support
+ * model independent data.  As of version zlib 1.0.4, the necessary changes
+ * have been made in zlib.  The USE_FAR_KEYWORD define triggers other
+ * changes that are needed. (Tim Wegner)
+ */
+/* Separate compiler dependencies (problem here is that zlib.h always
+ * defines FAR. (SJT)
+ */
+#ifdef __BORLANDC__
+#  if defined(__LARGE__) || defined(__HUGE__) || defined(__COMPACT__)
+#    define LDATA 1
+#  else
+#    define LDATA 0
+#  endif
+  /* GRR:  why is Cygwin in here?  Cygwin is not Borland C... */
+#  if !defined(__WIN32__) && !defined(__FLAT__) && !defined(__CYGWIN__)
+#    define PNG_MAX_MALLOC_64K /* only used in build */
+#    if (LDATA != 1)
+#      ifndef FAR
+#        define FAR __far
+#      endif
+#      define USE_FAR_KEYWORD
+#    endif   /* LDATA != 1 */
+         /* Possibly useful for moving data out of default segment.
+          * Uncomment it if you want. Could also define FARDATA as
+          * const if your compiler supports it. (SJT)
+#        define FARDATA FAR
+          */
+#  endif  /* __WIN32__, __FLAT__, __CYGWIN__ */
+#endif   /* __BORLANDC__ */
+/* Suggest testing for specific compiler first before testing for
+ * FAR.  The Watcom compiler defines both __MEDIUM__ and M_I86MM,
+ * making reliance oncertain keywords suspect. (SJT)
+ */
+/* MSC Medium model */
+#ifdef FAR
+#  ifdef M_I86MM
+#    define USE_FAR_KEYWORD
+#    define FARDATA FAR
+#    include <dos.h>
+#  endif
+#endif
+/* SJT: default case */
+#ifndef FAR
+#  define FAR
+#endif
+/* At this point FAR is always defined */
+#ifndef FARDATA
+#  define FARDATA
+#endif
+/* Typedef for floating-point numbers that are converted
+ * to fixed-point with a multiple of 100,000, e.g., gamma
+ */
+typedef png_int_32 png_fixed_point;
+/* Add typedefs for pointers */
+typedef void                      FAR * png_voidp;
+typedef PNG_CONST void            FAR * png_const_voidp;
+typedef png_byte                  FAR * png_bytep;
+typedef PNG_CONST png_byte        FAR * png_const_bytep;
+typedef png_uint_32               FAR * png_uint_32p;
+typedef PNG_CONST png_uint_32     FAR * png_const_uint_32p;
+typedef png_int_32                FAR * png_int_32p;
+typedef PNG_CONST png_int_32      FAR * png_const_int_32p;
+typedef png_uint_16               FAR * png_uint_16p;
+typedef PNG_CONST png_uint_16     FAR * png_const_uint_16p;
+typedef png_int_16                FAR * png_int_16p;
+typedef PNG_CONST png_int_16      FAR * png_const_int_16p;
+typedef char                      FAR * png_charp;
+typedef PNG_CONST char            FAR * png_const_charp;
+typedef png_fixed_point           FAR * png_fixed_point_p;
+typedef PNG_CONST png_fixed_point FAR * png_const_fixed_point_p;
+typedef png_size_t                FAR * png_size_tp;
+typedef PNG_CONST png_size_t      FAR * png_const_size_tp;
+#ifdef PNG_STDIO_SUPPORTED
+typedef FILE            * png_FILE_p;
+#endif
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+typedef double           FAR * png_doublep;
+typedef PNG_CONST double FAR * png_const_doublep;
+#endif
+/* Pointers to pointers; i.e. arrays */
+typedef png_byte        FAR * FAR * png_bytepp;
+typedef png_uint_32     FAR * FAR * png_uint_32pp;
+typedef png_int_32      FAR * FAR * png_int_32pp;
+typedef png_uint_16     FAR * FAR * png_uint_16pp;
+typedef png_int_16      FAR * FAR * png_int_16pp;
+typedef PNG_CONST char  FAR * FAR * png_const_charpp;
+typedef char            FAR * FAR * png_charpp;
+typedef png_fixed_point FAR * FAR * png_fixed_point_pp;
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+typedef double          FAR * FAR * png_doublepp;
+#endif
+/* Pointers to pointers to pointers; i.e., pointer to array */
+typedef char            FAR * FAR * FAR * png_charppp;
+/* png_alloc_size_t is guaranteed to be no smaller than png_size_t,
+ * and no smaller than png_uint_32.  Casts from png_size_t or png_uint_32
+ * to png_alloc_size_t are not necessary; in fact, it is recommended
+ * not to use them at all so that the compiler can complain when something
+ * turns out to be problematic.
+ * Casts in the other direction (from png_alloc_size_t to png_size_t or
+ * png_uint_32) should be explicitly applied; however, we do not expect
+ * to encounter practical situations that require such conversions.
+ */
+#if defined(__TURBOC__) && !defined(__FLAT__)
+   typedef unsigned long png_alloc_size_t;
+#else
+#  if defined(_MSC_VER) && defined(MAXSEG_64K)
+     typedef unsigned long    png_alloc_size_t;
+#  else
+     /* This is an attempt to detect an old Windows system where (int) is
+      * actually 16 bits, in that case png_malloc must have an argument with a
+      * bigger size to accomodate the requirements of the library.
+      */
+#    if (defined(_Windows) || defined(_WINDOWS) || defined(_WINDOWS_)) && \
+        (!defined(INT_MAX) || INT_MAX <= 0x7ffffffeL)
+       typedef DWORD         png_alloc_size_t;
+#    else
+       typedef png_size_t    png_alloc_size_t;
+#    endif
+#  endif
+#endif
+#endif /* PNGCONF_H */
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngdebug.h b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngdebug.h
new file mode 100644
index 0000000..96c1ea4
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngdebug.h
@@ -0,0 +1,157 @@
+/* pngdebug.h - Debugging macros for libpng, also used in pngtest.c
+ *
+ * Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * Last changed in libpng 1.5.0 [January 6, 2011]
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+/* Define PNG_DEBUG at compile time for debugging information.  Higher
+ * numbers for PNG_DEBUG mean more debugging information.  This has
+ * only been added since version 0.95 so it is not implemented throughout
+ * libpng yet, but more support will be added as needed.
+ *
+ * png_debug[1-2]?(level, message ,arg{0-2})
+ *   Expands to a statement (either a simple expression or a compound
+ *   do..while(0) statement) that outputs a message with parameter
+ *   substitution if PNG_DEBUG is defined to 2 or more.  If PNG_DEBUG
+ *   is undefined, 0 or 1 every png_debug expands to a simple expression
+ *   (actually ((void)0)).
+ *
+ *   level: level of detail of message, starting at 0.  A level 'n'
+ *          message is preceded by 'n' tab characters (not implemented
+ *          on Microsoft compilers unless PNG_DEBUG_FILE is also
+ *          defined, to allow debug DLL compilation with no standard IO).
+ *   message: a printf(3) style text string.  A trailing '\n' is added
+ *            to the message.
+ *   arg: 0 to 2 arguments for printf(3) style substitution in message.
+ */
+#ifndef PNGDEBUG_H
+#define PNGDEBUG_H
+/* These settings control the formatting of messages in png.c and pngerror.c */
+/* Moved to pngdebug.h at 1.5.0 */
+#  ifndef PNG_LITERAL_SHARP
+#    define PNG_LITERAL_SHARP 0x23
+#  endif
+#  ifndef PNG_LITERAL_LEFT_SQUARE_BRACKET
+#    define PNG_LITERAL_LEFT_SQUARE_BRACKET 0x5b
+#  endif
+#  ifndef PNG_LITERAL_RIGHT_SQUARE_BRACKET
+#    define PNG_LITERAL_RIGHT_SQUARE_BRACKET 0x5d
+#  endif
+#  ifndef PNG_STRING_NEWLINE
+#    define PNG_STRING_NEWLINE "\n"
+#  endif
+#ifdef PNG_DEBUG
+#  if (PNG_DEBUG > 0)
+#    if !defined(PNG_DEBUG_FILE) && defined(_MSC_VER)
+#      include <crtdbg.h>
+#      if (PNG_DEBUG > 1)
+#        ifndef _DEBUG
+#          define _DEBUG
+#        endif
+#        ifndef png_debug
+#          define png_debug(l,m)  _RPT0(_CRT_WARN,m PNG_STRING_NEWLINE)
+#        endif
+#        ifndef png_debug1
+#          define png_debug1(l,m,p1)  _RPT1(_CRT_WARN,m PNG_STRING_NEWLINE,p1)
+#        endif
+#        ifndef png_debug2
+#          define png_debug2(l,m,p1,p2) \
+             _RPT2(_CRT_WARN,m PNG_STRING_NEWLINE,p1,p2)
+#        endif
+#      endif
+#    else /* PNG_DEBUG_FILE || !_MSC_VER */
+#      ifndef PNG_STDIO_SUPPORTED
+#        include <stdio.h> /* not included yet */
+#      endif
+#      ifndef PNG_DEBUG_FILE
+#        define PNG_DEBUG_FILE stderr
+#      endif /* PNG_DEBUG_FILE */
+#      if (PNG_DEBUG > 1)
+/* Note: ["%s"m PNG_STRING_NEWLINE] probably does not work on
+ * non-ISO compilers
+ */
+#        ifdef __STDC__
+#          ifndef png_debug
+#            define png_debug(l,m) \
+       do { \
+       int num_tabs=l; \
+       fprintf(PNG_DEBUG_FILE,"%s"m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \
+         (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":"")))); \
+       } while (0)
+#          endif
+#          ifndef png_debug1
+#            define png_debug1(l,m,p1) \
+       do { \
+       int num_tabs=l; \
+       fprintf(PNG_DEBUG_FILE,"%s"m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \
+         (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1); \
+       } while (0)
+#          endif
+#          ifndef png_debug2
+#            define png_debug2(l,m,p1,p2) \
+       do { \
+       int num_tabs=l; \
+       fprintf(PNG_DEBUG_FILE,"%s"m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \
+         (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1,p2); \
+       } while (0)
+#          endif
+#        else /* __STDC __ */
+#          ifndef png_debug
+#            define png_debug(l,m) \
+       do { \
+       int num_tabs=l; \
+       char format[256]; \
+       snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
+         (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
+         m,PNG_STRING_NEWLINE); \
+       fprintf(PNG_DEBUG_FILE,format); \
+       } while (0)
+#          endif
+#          ifndef png_debug1
+#            define png_debug1(l,m,p1) \
+       do { \
+       int num_tabs=l; \
+       char format[256]; \
+       snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
+         (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
+         m,PNG_STRING_NEWLINE); \
+       fprintf(PNG_DEBUG_FILE,format,p1); \
+       } while (0)
+#          endif
+#          ifndef png_debug2
+#            define png_debug2(l,m,p1,p2) \
+       do { \
+       int num_tabs=l; \
+       char format[256]; \
+       snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
+         (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
+         m,PNG_STRING_NEWLINE); \
+       fprintf(PNG_DEBUG_FILE,format,p1,p2); \
+       } while (0)
+#          endif
+#        endif /* __STDC __ */
+#      endif /* (PNG_DEBUG > 1) */
+#    endif /* _MSC_VER */
+#  endif /* (PNG_DEBUG > 0) */
+#endif /* PNG_DEBUG */
+#ifndef png_debug
+#  define png_debug(l, m) ((void)0)
+#endif
+#ifndef png_debug1
+#  define png_debug1(l, m, p1) ((void)0)
+#endif
+#ifndef png_debug2
+#  define png_debug2(l, m, p1, p2) ((void)0)
+#endif
+#endif /* PNGDEBUG_H */
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngerror.c b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngerror.c
new file mode 100644
index 0000000..9df97f5
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngerror.c
@@ -0,0 +1,685 @@
+/* pngerror.c - stub functions for i/o and memory allocation
+ *
+ * Last changed in libpng 1.5.8 [February 1, 2011]
+ * Copyright (c) 1998-2012 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * This file provides a location for all error handling.  Users who
+ * need special error handling are expected to write replacement functions
+ * and use png_set_error_fn() to use those functions.  See the instructions
+ * at each function.
+ */
+#include "pngpriv.h"
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+static PNG_FUNCTION(void, png_default_error,PNGARG((png_structp png_ptr,
+    png_const_charp error_message)),PNG_NORETURN);
+#ifdef PNG_WARNINGS_SUPPORTED
+static void /* PRIVATE */
+png_default_warning PNGARG((png_structp png_ptr,
+   png_const_charp warning_message));
+#endif /* PNG_WARNINGS_SUPPORTED */
+/* This function is called whenever there is a fatal error.  This function
+ * should not be changed.  If there is a need to handle errors differently,
+ * you should supply a replacement error function and use png_set_error_fn()
+ * to replace the error function at run-time.
+ */
+#ifdef PNG_ERROR_TEXT_SUPPORTED
+PNG_FUNCTION(void,PNGAPI
+png_error,(png_structp png_ptr, png_const_charp error_message),PNG_NORETURN)
+{
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+   char msg[16];
+   if (png_ptr != NULL)
+   {
+      if (png_ptr->flags&
+         (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT))
+      {
+         if (*error_message == PNG_LITERAL_SHARP)
+         {
+            /* Strip "#nnnn " from beginning of error message. */
+            int offset;
+            for (offset = 1; offset<15; offset++)
+               if (error_message[offset] == ' ')
+                  break;
+            if (png_ptr->flags&PNG_FLAG_STRIP_ERROR_TEXT)
+            {
+               int i;
+               for (i = 0; i < offset - 1; i++)
+                  msg[i] = error_message[i + 1];
+               msg[i - 1] = '\0';
+               error_message = msg;
+            }
+            else
+               error_message += offset;
+      }
+      else
+      {
+         if (png_ptr->flags&PNG_FLAG_STRIP_ERROR_TEXT)
+         {
+            msg[0] = '0';
+            msg[1] = '\0';
+            error_message = msg;
+         }
+       }
+     }
+   }
+#endif
+   if (png_ptr != NULL && png_ptr->error_fn != NULL)
+      (*(png_ptr->error_fn))(png_ptr, error_message);
+   /* If the custom handler doesn't exist, or if it returns,
+      use the default handler, which will not return. */
+   png_default_error(png_ptr, error_message);
+}
+#else
+PNG_FUNCTION(void,PNGAPI
+png_err,(png_structp png_ptr),PNG_NORETURN)
+{
+   /* Prior to 1.5.2 the error_fn received a NULL pointer, expressed
+    * erroneously as '\0', instead of the empty string "".  This was
+    * apparently an error, introduced in libpng-1.2.20, and png_default_error
+    * will crash in this case.
+    */
+   if (png_ptr != NULL && png_ptr->error_fn != NULL)
+      (*(png_ptr->error_fn))(png_ptr, "");
+   /* If the custom handler doesn't exist, or if it returns,
+      use the default handler, which will not return. */
+   png_default_error(png_ptr, "");
+}
+#endif /* PNG_ERROR_TEXT_SUPPORTED */
+/* Utility to safely appends strings to a buffer.  This never errors out so
+ * error checking is not required in the caller.
+ */
+size_t
+png_safecat(png_charp buffer, size_t bufsize, size_t pos,
+   png_const_charp string)
+{
+   if (buffer != NULL && pos < bufsize)
+   {
+      if (string != NULL)
+         while (*string != '\0' && pos < bufsize-1)
+           buffer[pos++] = *string++;
+      buffer[pos] = '\0';
+   }
+   return pos;
+}
+#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_SUPPORTED)
+/* Utility to dump an unsigned value into a buffer, given a start pointer and
+ * and end pointer (which should point just *beyond* the end of the buffer!)
+ * Returns the pointer to the start of the formatted string.
+ */
+png_charp
+png_format_number(png_const_charp start, png_charp end, int format,
+   png_alloc_size_t number)
+{
+   int count = 0;    /* number of digits output */
+   int mincount = 1; /* minimum number required */
+   int output = 0;   /* digit output (for the fixed point format) */
+   *--end = '\0';
+   /* This is written so that the loop always runs at least once, even with
+    * number zero.
+    */
+   while (end > start && (number != 0 || count < mincount))
+   {
+      static const char digits[] = "0123456789ABCDEF";
+      switch (format)
+      {
+         case PNG_NUMBER_FORMAT_fixed:
+            /* Needs five digits (the fraction) */
+            mincount = 5;
+            if (output || number % 10 != 0)
+            {
+               *--end = digits[number % 10];
+               output = 1;
+            }
+            number /= 10;
+            break;
+         case PNG_NUMBER_FORMAT_02u:
+            /* Expects at least 2 digits. */
+            mincount = 2;
+            /* fall through */
+         case PNG_NUMBER_FORMAT_u:
+            *--end = digits[number % 10];
+            number /= 10;
+            break;
+         case PNG_NUMBER_FORMAT_02x:
+            /* This format expects at least two digits */
+            mincount = 2;
+            /* fall through */
+         case PNG_NUMBER_FORMAT_x:
+            *--end = digits[number & 0xf];
+            number >>= 4;
+            break;
+         default: /* an error */
+            number = 0;
+            break;
+      }
+      /* Keep track of the number of digits added */
+      ++count;
+      /* Float a fixed number here: */
+      if (format == PNG_NUMBER_FORMAT_fixed) if (count == 5) if (end > start)
+      {
+         /* End of the fraction, but maybe nothing was output?  In that case
+          * drop the decimal point.  If the number is a true zero handle that
+          * here.
+          */
+         if (output)
+            *--end = '.';
+         else if (number == 0) /* and !output */
+            *--end = '0';
+      }
+   }
+   return end;
+}
+#endif
+#ifdef PNG_WARNINGS_SUPPORTED
+/* This function is called whenever there is a non-fatal error.  This function
+ * should not be changed.  If there is a need to handle warnings differently,
+ * you should supply a replacement warning function and use
+ * png_set_error_fn() to replace the warning function at run-time.
+ */
+void PNGAPI
+png_warning(png_structp png_ptr, png_const_charp warning_message)
+{
+   int offset = 0;
+   if (png_ptr != NULL)
+   {
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+   if (png_ptr->flags&
+       (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT))
+#endif
+      {
+         if (*warning_message == PNG_LITERAL_SHARP)
+         {
+            for (offset = 1; offset < 15; offset++)
+               if (warning_message[offset] == ' ')
+                  break;
+         }
+      }
+   }
+   if (png_ptr != NULL && png_ptr->warning_fn != NULL)
+      (*(png_ptr->warning_fn))(png_ptr, warning_message + offset);
+   else
+      png_default_warning(png_ptr, warning_message + offset);
+}
+/* These functions support 'formatted' warning messages with up to
+ * PNG_WARNING_PARAMETER_COUNT parameters.  In the format string the parameter
+ * is introduced by @<number>, where 'number' starts at 1.  This follows the
+ * standard established by X/Open for internationalizable error messages.
+ */
+void
+png_warning_parameter(png_warning_parameters p, int number,
+   png_const_charp string)
+{
+   if (number > 0 && number <= PNG_WARNING_PARAMETER_COUNT)
+      (void)png_safecat(p[number-1], (sizeof p[number-1]), 0, string);
+}
+void
+png_warning_parameter_unsigned(png_warning_parameters p, int number, int format,
+   png_alloc_size_t value)
+{
+   char buffer[PNG_NUMBER_BUFFER_SIZE];
+   png_warning_parameter(p, number, PNG_FORMAT_NUMBER(buffer, format, value));
+}
+void
+png_warning_parameter_signed(png_warning_parameters p, int number, int format,
+   png_int_32 value)
+{
+   png_alloc_size_t u;
+   png_charp str;
+   char buffer[PNG_NUMBER_BUFFER_SIZE];
+   /* Avoid overflow by doing the negate in a png_alloc_size_t: */
+   u = (png_alloc_size_t)value;
+   if (value < 0)
+      u = ~u + 1;
+   str = PNG_FORMAT_NUMBER(buffer, format, u);
+   if (value < 0 && str > buffer)
+      *--str = '-';
+   png_warning_parameter(p, number, str);
+}
+void
+png_formatted_warning(png_structp png_ptr, png_warning_parameters p,
+   png_const_charp message)
+{
+   /* The internal buffer is just 192 bytes - enough for all our messages,
+    * overflow doesn't happen because this code checks!  If someone figures
+    * out how to send us a message longer than 192 bytes, all that will
+    * happen is that the message will be truncated appropriately.
+    */
+   size_t i = 0; /* Index in the msg[] buffer: */
+   char msg[192];
+   /* Each iteration through the following loop writes at most one character
+    * to msg[i++] then returns here to validate that there is still space for
+    * the trailing '\0'.  It may (in the case of a parameter) read more than
+    * one character from message[]; it must check for '\0' and continue to the
+    * test if it finds the end of string.
+    */
+   while (i<(sizeof msg)-1 && *message != '\0')
+   {
+      /* '@' at end of string is now just printed (previously it was skipped);
+       * it is an error in the calling code to terminate the string with @.
+       */
+      if (p != NULL && *message == '@' && message[1] != '\0')
+      {
+         int parameter_char = *++message; /* Consume the '@' */
+         static const char valid_parameters[] = "123456789";
+         int parameter = 0;
+         /* Search for the parameter digit, the index in the string is the
+          * parameter to use.
+          */
+         while (valid_parameters[parameter] != parameter_char &&
+            valid_parameters[parameter] != '\0')
+            ++parameter;
+         /* If the parameter digit is out of range it will just get printed. */
+         if (parameter < PNG_WARNING_PARAMETER_COUNT)
+         {
+            /* Append this parameter */
+            png_const_charp parm = p[parameter];
+            png_const_charp pend = p[parameter] + (sizeof p[parameter]);
+            /* No need to copy the trailing '\0' here, but there is no guarantee
+             * that parm[] has been initialized, so there is no guarantee of a
+             * trailing '\0':
+             */
+            while (i<(sizeof msg)-1 && *parm != '\0' && parm < pend)
+               msg[i++] = *parm++;
+            /* Consume the parameter digit too: */
+            ++message;
+            continue;
+         }
+         /* else not a parameter and there is a character after the @ sign; just
+          * copy that.  This is known not to be '\0' because of the test above.
+          */
+      }
+      /* At this point *message can't be '\0', even in the bad parameter case
+       * above where there is a lone '@' at the end of the message string.
+       */
+      msg[i++] = *message++;
+   }
+   /* i is always less than (sizeof msg), so: */
+   msg[i] = '\0';
+   /* And this is the formatted message, it may be larger than
+    * PNG_MAX_ERROR_TEXT, but that is only used for 'chunk' errors and these are
+    * not (currently) formatted.
+    */
+   png_warning(png_ptr, msg);
+}
+#endif /* PNG_WARNINGS_SUPPORTED */
+#ifdef PNG_BENIGN_ERRORS_SUPPORTED
+void PNGAPI
+png_benign_error(png_structp png_ptr, png_const_charp error_message)
+{
+  if (png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN)
+     png_warning(png_ptr, error_message);
+  else
+     png_error(png_ptr, error_message);
+}
+#endif
+/* These utilities are used internally to build an error message that relates
+ * to the current chunk.  The chunk name comes from png_ptr->chunk_name,
+ * this is used to prefix the message.  The message is limited in length
+ * to 63 bytes, the name characters are output as hex digits wrapped in []
+ * if the character is invalid.
+ */
+#define isnonalpha(c) ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97))
+static PNG_CONST char png_digit[16] = {
+   '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
+   'A', 'B', 'C', 'D', 'E', 'F'
+};
+#define PNG_MAX_ERROR_TEXT 64
+#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_ERROR_TEXT_SUPPORTED)
+static void /* PRIVATE */
+png_format_buffer(png_structp png_ptr, png_charp buffer, png_const_charp
+    error_message)
+{
+   png_uint_32 chunk_name = png_ptr->chunk_name;
+   int iout = 0, ishift = 24;
+   while (ishift >= 0)
+   {
+      int c = (int)(chunk_name >> ishift) & 0xff;
+      ishift -= 8;
+      if (isnonalpha(c))
+      {
+         buffer[iout++] = PNG_LITERAL_LEFT_SQUARE_BRACKET;
+         buffer[iout++] = png_digit[(c & 0xf0) >> 4];
+         buffer[iout++] = png_digit[c & 0x0f];
+         buffer[iout++] = PNG_LITERAL_RIGHT_SQUARE_BRACKET;
+      }
+      else
+      {
+         buffer[iout++] = (char)c;
+      }
+   }
+   if (error_message == NULL)
+      buffer[iout] = '\0';
+   else
+   {
+      int iin = 0;
+      buffer[iout++] = ':';
+      buffer[iout++] = ' ';
+      while (iin < PNG_MAX_ERROR_TEXT-1 && error_message[iin] != '\0')
+         buffer[iout++] = error_message[iin++];
+      /* iin < PNG_MAX_ERROR_TEXT, so the following is safe: */
+      buffer[iout] = '\0';
+   }
+}
+#endif /* PNG_WARNINGS_SUPPORTED || PNG_ERROR_TEXT_SUPPORTED */
+#if defined(PNG_READ_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED)
+PNG_FUNCTION(void,PNGAPI
+png_chunk_error,(png_structp png_ptr, png_const_charp error_message),
+   PNG_NORETURN)
+{
+   char msg[18+PNG_MAX_ERROR_TEXT];
+   if (png_ptr == NULL)
+      png_error(png_ptr, error_message);
+   else
+   {
+      png_format_buffer(png_ptr, msg, error_message);
+      png_error(png_ptr, msg);
+   }
+}
+#endif /* PNG_READ_SUPPORTED && PNG_ERROR_TEXT_SUPPORTED */
+#ifdef PNG_WARNINGS_SUPPORTED
+void PNGAPI
+png_chunk_warning(png_structp png_ptr, png_const_charp warning_message)
+{
+   char msg[18+PNG_MAX_ERROR_TEXT];
+   if (png_ptr == NULL)
+      png_warning(png_ptr, warning_message);
+   else
+   {
+      png_format_buffer(png_ptr, msg, warning_message);
+      png_warning(png_ptr, msg);
+   }
+}
+#endif /* PNG_WARNINGS_SUPPORTED */
+#ifdef PNG_READ_SUPPORTED
+#ifdef PNG_BENIGN_ERRORS_SUPPORTED
+void PNGAPI
+png_chunk_benign_error(png_structp png_ptr, png_const_charp error_message)
+{
+   if (png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN)
+      png_chunk_warning(png_ptr, error_message);
+   else
+      png_chunk_error(png_ptr, error_message);
+}
+#endif
+#endif /* PNG_READ_SUPPORTED */
+#ifdef PNG_ERROR_TEXT_SUPPORTED
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+PNG_FUNCTION(void,
+png_fixed_error,(png_structp png_ptr, png_const_charp name),PNG_NORETURN)
+{
+#  define fixed_message "fixed point overflow in "
+#  define fixed_message_ln ((sizeof fixed_message)-1)
+   int  iin;
+   char msg[fixed_message_ln+PNG_MAX_ERROR_TEXT];
+   png_memcpy(msg, fixed_message, fixed_message_ln);
+   iin = 0;
+   if (name != NULL) while (iin < (PNG_MAX_ERROR_TEXT-1) && name[iin] != 0)
+   {
+      msg[fixed_message_ln + iin] = name[iin];
+      ++iin;
+   }
+   msg[fixed_message_ln + iin] = 0;
+   png_error(png_ptr, msg);
+}
+#endif
+#endif
+#ifdef PNG_SETJMP_SUPPORTED
+/* This API only exists if ANSI-C style error handling is used,
+ * otherwise it is necessary for png_default_error to be overridden.
+ */
+jmp_buf* PNGAPI
+png_set_longjmp_fn(png_structp png_ptr, png_longjmp_ptr longjmp_fn,
+    size_t jmp_buf_size)
+{
+   if (png_ptr == NULL || jmp_buf_size != png_sizeof(jmp_buf))
+      return NULL;
+   png_ptr->longjmp_fn = longjmp_fn;
+   return &png_ptr->longjmp_buffer;
+}
+#endif
+/* This is the default error handling function.  Note that replacements for
+ * this function MUST NOT RETURN, or the program will likely crash.  This
+ * function is used by default, or if the program supplies NULL for the
+ * error function pointer in png_set_error_fn().
+ */
+static PNG_FUNCTION(void /* PRIVATE */,
+png_default_error,(png_structp png_ptr, png_const_charp error_message),
+   PNG_NORETURN)
+{
+#ifdef PNG_CONSOLE_IO_SUPPORTED
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+   /* Check on NULL only added in 1.5.4 */
+   if (error_message != NULL && *error_message == PNG_LITERAL_SHARP)
+   {
+      /* Strip "#nnnn " from beginning of error message. */
+      int offset;
+      char error_number[16];
+      for (offset = 0; offset<15; offset++)
+      {
+         error_number[offset] = error_message[offset + 1];
+         if (error_message[offset] == ' ')
+            break;
+      }
+      if ((offset > 1) && (offset < 15))
+      {
+         error_number[offset - 1] = '\0';
+         fprintf(stderr, "libpng error no. %s: %s",
+             error_number, error_message + offset + 1);
+         fprintf(stderr, PNG_STRING_NEWLINE);
+      }
+      else
+      {
+         fprintf(stderr, "libpng error: %s, offset=%d",
+             error_message, offset);
+         fprintf(stderr, PNG_STRING_NEWLINE);
+      }
+   }
+   else
+#endif
+   {
+      fprintf(stderr, "libpng error: %s", error_message ? error_message :
+         "undefined");
+      fprintf(stderr, PNG_STRING_NEWLINE);
+   }
+#else
+   PNG_UNUSED(error_message) /* Make compiler happy */
+#endif
+   png_longjmp(png_ptr, 1);
+}
+PNG_FUNCTION(void,PNGAPI
+png_longjmp,(png_structp png_ptr, int val),PNG_NORETURN)
+{
+#ifdef PNG_SETJMP_SUPPORTED
+   if (png_ptr && png_ptr->longjmp_fn)
+   {
+#  ifdef USE_FAR_KEYWORD
+      {
+         jmp_buf tmp_jmpbuf;
+         png_memcpy(tmp_jmpbuf, png_ptr->longjmp_buffer, png_sizeof(jmp_buf));
+         png_ptr->longjmp_fn(tmp_jmpbuf, val);
+      }
+#  else
+   png_ptr->longjmp_fn(png_ptr->longjmp_buffer, val);
+#  endif
+   }
+#endif
+   /* Here if not setjmp support or if png_ptr is null. */
+   PNG_ABORT();
+}
+#ifdef PNG_WARNINGS_SUPPORTED
+/* This function is called when there is a warning, but the library thinks
+ * it can continue anyway.  Replacement functions don't have to do anything
+ * here if you don't want them to.  In the default configuration, png_ptr is
+ * not used, but it is passed in case it may be useful.
+ */
+static void /* PRIVATE */
+png_default_warning(png_structp png_ptr, png_const_charp warning_message)
+{
+#ifdef PNG_CONSOLE_IO_SUPPORTED
+#  ifdef PNG_ERROR_NUMBERS_SUPPORTED
+   if (*warning_message == PNG_LITERAL_SHARP)
+   {
+      int offset;
+      char warning_number[16];
+      for (offset = 0; offset < 15; offset++)
+      {
+         warning_number[offset] = warning_message[offset + 1];
+         if (warning_message[offset] == ' ')
+            break;
+      }
+      if ((offset > 1) && (offset < 15))
+      {
+         warning_number[offset + 1] = '\0';
+         fprintf(stderr, "libpng warning no. %s: %s",
+             warning_number, warning_message + offset);
+         fprintf(stderr, PNG_STRING_NEWLINE);
+      }
+      else
+      {
+         fprintf(stderr, "libpng warning: %s",
+             warning_message);
+         fprintf(stderr, PNG_STRING_NEWLINE);
+      }
+   }
+   else
+#  endif
+   {
+      fprintf(stderr, "libpng warning: %s", warning_message);
+      fprintf(stderr, PNG_STRING_NEWLINE);
+   }
+#else
+   PNG_UNUSED(warning_message) /* Make compiler happy */
+#endif
+   PNG_UNUSED(png_ptr) /* Make compiler happy */
+}
+#endif /* PNG_WARNINGS_SUPPORTED */
+/* This function is called when the application wants to use another method
+ * of handling errors and warnings.  Note that the error function MUST NOT
+ * return to the calling routine or serious problems will occur.  The return
+ * method used in the default routine calls longjmp(png_ptr->longjmp_buffer, 1)
+ */
+void PNGAPI
+png_set_error_fn(png_structp png_ptr, png_voidp error_ptr,
+    png_error_ptr error_fn, png_error_ptr warning_fn)
+{
+   if (png_ptr == NULL)
+      return;
+   png_ptr->error_ptr = error_ptr;
+   png_ptr->error_fn = error_fn;
+#ifdef PNG_WARNINGS_SUPPORTED
+   png_ptr->warning_fn = warning_fn;
+#else
+   PNG_UNUSED(warning_fn)
+#endif
+}
+/* This function returns a pointer to the error_ptr associated with the user
+ * functions.  The application should free any memory associated with this
+ * pointer before png_write_destroy and png_read_destroy are called.
+ */
+png_voidp PNGAPI
+png_get_error_ptr(png_const_structp png_ptr)
+{
+   if (png_ptr == NULL)
+      return NULL;
+   return ((png_voidp)png_ptr->error_ptr);
+}
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+void PNGAPI
+png_set_strip_error_numbers(png_structp png_ptr, png_uint_32 strip_mode)
+{
+   if (png_ptr != NULL)
+   {
+      png_ptr->flags &=
+         ((~(PNG_FLAG_STRIP_ERROR_NUMBERS |
+         PNG_FLAG_STRIP_ERROR_TEXT))&strip_mode);
+   }
+}
+#endif
+#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngget.c b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngget.c
new file mode 100644
index 0000000..1889e99
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngget.c
@@ -0,0 +1,1124 @@
+/* pngget.c - retrieval of values from info struct
+ *
+ * Last changed in libpng 1.5.7 [December 15, 2011]
+ * Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ */
+#include "pngpriv.h"
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+png_uint_32 PNGAPI
+png_get_valid(png_const_structp png_ptr, png_const_infop info_ptr,
+    png_uint_32 flag)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+      return(info_ptr->valid & flag);
+   return(0);
+}
+png_size_t PNGAPI
+png_get_rowbytes(png_const_structp png_ptr, png_const_infop info_ptr)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+      return(info_ptr->rowbytes);
+   return(0);
+}
+#ifdef PNG_INFO_IMAGE_SUPPORTED
+png_bytepp PNGAPI
+png_get_rows(png_const_structp png_ptr, png_const_infop info_ptr)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+      return(info_ptr->row_pointers);
+   return(0);
+}
+#endif
+#ifdef PNG_EASY_ACCESS_SUPPORTED
+/* Easy access to info, added in libpng-0.99 */
+png_uint_32 PNGAPI
+png_get_image_width(png_const_structp png_ptr, png_const_infop info_ptr)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+      return info_ptr->width;
+   return (0);
+}
+png_uint_32 PNGAPI
+png_get_image_height(png_const_structp png_ptr, png_const_infop info_ptr)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+      return info_ptr->height;
+   return (0);
+}
+png_byte PNGAPI
+png_get_bit_depth(png_const_structp png_ptr, png_const_infop info_ptr)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+      return info_ptr->bit_depth;
+   return (0);
+}
+png_byte PNGAPI
+png_get_color_type(png_const_structp png_ptr, png_const_infop info_ptr)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+      return info_ptr->color_type;
+   return (0);
+}
+png_byte PNGAPI
+png_get_filter_type(png_const_structp png_ptr, png_const_infop info_ptr)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+      return info_ptr->filter_type;
+   return (0);
+}
+png_byte PNGAPI
+png_get_interlace_type(png_const_structp png_ptr, png_const_infop info_ptr)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+      return info_ptr->interlace_type;
+   return (0);
+}
+png_byte PNGAPI
+png_get_compression_type(png_const_structp png_ptr, png_const_infop info_ptr)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+      return info_ptr->compression_type;
+   return (0);
+}
+png_uint_32 PNGAPI
+png_get_x_pixels_per_meter(png_const_structp png_ptr, png_const_infop info_ptr)
+{
+#ifdef PNG_pHYs_SUPPORTED
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
+      {
+         png_debug1(1, "in %s retrieval function",
+             "png_get_x_pixels_per_meter");
+         if (info_ptr->phys_unit_type == PNG_RESOLUTION_METER)
+            return (info_ptr->x_pixels_per_unit);
+      }
+#endif
+   return (0);
+}
+png_uint_32 PNGAPI
+png_get_y_pixels_per_meter(png_const_structp png_ptr, png_const_infop info_ptr)
+{
+#ifdef PNG_pHYs_SUPPORTED
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
+   {
+      png_debug1(1, "in %s retrieval function",
+          "png_get_y_pixels_per_meter");
+      if (info_ptr->phys_unit_type == PNG_RESOLUTION_METER)
+         return (info_ptr->y_pixels_per_unit);
+   }
+#endif
+   return (0);
+}
+png_uint_32 PNGAPI
+png_get_pixels_per_meter(png_const_structp png_ptr, png_const_infop info_ptr)
+{
+#ifdef PNG_pHYs_SUPPORTED
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
+   {
+      png_debug1(1, "in %s retrieval function", "png_get_pixels_per_meter");
+      if (info_ptr->phys_unit_type == PNG_RESOLUTION_METER &&
+          info_ptr->x_pixels_per_unit == info_ptr->y_pixels_per_unit)
+         return (info_ptr->x_pixels_per_unit);
+   }
+#endif
+   return (0);
+}
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+float PNGAPI
+png_get_pixel_aspect_ratio(png_const_structp png_ptr, png_const_infop info_ptr)
+{
+#ifdef PNG_READ_pHYs_SUPPORTED
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
+   {
+      png_debug1(1, "in %s retrieval function", "png_get_aspect_ratio");
+      if (info_ptr->x_pixels_per_unit != 0)
+         return ((float)((float)info_ptr->y_pixels_per_unit
+             /(float)info_ptr->x_pixels_per_unit));
+   }
+#endif
+   return ((float)0.0);
+}
+#endif
+#ifdef PNG_FIXED_POINT_SUPPORTED
+png_fixed_point PNGAPI
+png_get_pixel_aspect_ratio_fixed(png_const_structp png_ptr,
+    png_const_infop info_ptr)
+{
+#ifdef PNG_READ_pHYs_SUPPORTED
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs)
+       && info_ptr->x_pixels_per_unit > 0 && info_ptr->y_pixels_per_unit > 0
+       && info_ptr->x_pixels_per_unit <= PNG_UINT_31_MAX
+       && info_ptr->y_pixels_per_unit <= PNG_UINT_31_MAX)
+   {
+      png_fixed_point res;
+      png_debug1(1, "in %s retrieval function", "png_get_aspect_ratio_fixed");
+      /* The following casts work because a PNG 4 byte integer only has a valid
+       * range of 0..2^31-1; otherwise the cast might overflow.
+       */
+      if (png_muldiv(&res, (png_int_32)info_ptr->y_pixels_per_unit, PNG_FP_1,
+          (png_int_32)info_ptr->x_pixels_per_unit))
+         return res;
+   }
+#endif
+   return 0;
+}
+#endif
+png_int_32 PNGAPI
+png_get_x_offset_microns(png_const_structp png_ptr, png_const_infop info_ptr)
+{
+#ifdef PNG_oFFs_SUPPORTED
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
+   {
+      png_debug1(1, "in %s retrieval function", "png_get_x_offset_microns");
+      if (info_ptr->offset_unit_type == PNG_OFFSET_MICROMETER)
+         return (info_ptr->x_offset);
+   }
+#endif
+   return (0);
+}
+png_int_32 PNGAPI
+png_get_y_offset_microns(png_const_structp png_ptr, png_const_infop info_ptr)
+{
+#ifdef PNG_oFFs_SUPPORTED
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
+   {
+      png_debug1(1, "in %s retrieval function", "png_get_y_offset_microns");
+      if (info_ptr->offset_unit_type == PNG_OFFSET_MICROMETER)
+         return (info_ptr->y_offset);
+   }
+#endif
+   return (0);
+}
+png_int_32 PNGAPI
+png_get_x_offset_pixels(png_const_structp png_ptr, png_const_infop info_ptr)
+{
+#ifdef PNG_oFFs_SUPPORTED
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
+   {
+      png_debug1(1, "in %s retrieval function", "png_get_x_offset_pixels");
+      if (info_ptr->offset_unit_type == PNG_OFFSET_PIXEL)
+         return (info_ptr->x_offset);
+   }
+#endif
+   return (0);
+}
+png_int_32 PNGAPI
+png_get_y_offset_pixels(png_const_structp png_ptr, png_const_infop info_ptr)
+{
+#ifdef PNG_oFFs_SUPPORTED
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
+   {
+      png_debug1(1, "in %s retrieval function", "png_get_y_offset_pixels");
+      if (info_ptr->offset_unit_type == PNG_OFFSET_PIXEL)
+         return (info_ptr->y_offset);
+   }
+#endif
+   return (0);
+}
+#ifdef PNG_INCH_CONVERSIONS_SUPPORTED
+static png_uint_32
+ppi_from_ppm(png_uint_32 ppm)
+{
+#if 0
+   /* The conversion is *(2.54/100), in binary (32 digits):
+    * .00000110100000001001110101001001
+    */
+   png_uint_32 t1001, t1101;
+   ppm >>= 1;                  /* .1 */
+   t1001 = ppm + (ppm >> 3);   /* .1001 */
+   t1101 = t1001 + (ppm >> 1); /* .1101 */
+   ppm >>= 20;                 /* .000000000000000000001 */
+   t1101 += t1101 >> 15;       /* .1101000000000001101 */
+   t1001 >>= 11;               /* .000000000001001 */
+   t1001 += t1001 >> 12;       /* .000000000001001000000001001 */
+   ppm += t1001;               /* .000000000001001000001001001 */
+   ppm += t1101;               /* .110100000001001110101001001 */
+   return (ppm + 16) >> 5;/* .00000110100000001001110101001001 */
+#else
+   /* The argument is a PNG unsigned integer, so it is not permitted
+    * to be bigger than 2^31.
+    */
+   png_fixed_point result;
+   if (ppm <= PNG_UINT_31_MAX && png_muldiv(&result, (png_int_32)ppm, 127,
+       5000))
+      return result;
+   /* Overflow. */
+   return 0;
+#endif
+}
+png_uint_32 PNGAPI
+png_get_pixels_per_inch(png_const_structp png_ptr, png_const_infop info_ptr)
+{
+   return ppi_from_ppm(png_get_pixels_per_meter(png_ptr, info_ptr));
+}
+png_uint_32 PNGAPI
+png_get_x_pixels_per_inch(png_const_structp png_ptr, png_const_infop info_ptr)
+{
+   return ppi_from_ppm(png_get_x_pixels_per_meter(png_ptr, info_ptr));
+}
+png_uint_32 PNGAPI
+png_get_y_pixels_per_inch(png_const_structp png_ptr, png_const_infop info_ptr)
+{
+   return ppi_from_ppm(png_get_y_pixels_per_meter(png_ptr, info_ptr));
+}
+#ifdef PNG_FIXED_POINT_SUPPORTED
+static png_fixed_point
+png_fixed_inches_from_microns(png_structp png_ptr, png_int_32 microns)
+{
+   /* Convert from metres * 1,000,000 to inches * 100,000, meters to
+    * inches is simply *(100/2.54), so we want *(10/2.54) == 500/127.
+    * Notice that this can overflow - a warning is output and 0 is
+    * returned.
+    */
+   return png_muldiv_warn(png_ptr, microns, 500, 127);
+}
+png_fixed_point PNGAPI
+png_get_x_offset_inches_fixed(png_structp png_ptr,
+    png_const_infop info_ptr)
+{
+   return png_fixed_inches_from_microns(png_ptr,
+       png_get_x_offset_microns(png_ptr, info_ptr));
+}
+#endif
+#ifdef PNG_FIXED_POINT_SUPPORTED
+png_fixed_point PNGAPI
+png_get_y_offset_inches_fixed(png_structp png_ptr,
+    png_const_infop info_ptr)
+{
+   return png_fixed_inches_from_microns(png_ptr,
+       png_get_y_offset_microns(png_ptr, info_ptr));
+}
+#endif
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+float PNGAPI
+png_get_x_offset_inches(png_const_structp png_ptr, png_const_infop info_ptr)
+{
+   /* To avoid the overflow do the conversion directly in floating
+    * point.
+    */
+   return (float)(png_get_x_offset_microns(png_ptr, info_ptr) * .00003937);
+}
+#endif
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+float PNGAPI
+png_get_y_offset_inches(png_const_structp png_ptr, png_const_infop info_ptr)
+{
+   /* To avoid the overflow do the conversion directly in floating
+    * point.
+    */
+   return (float)(png_get_y_offset_microns(png_ptr, info_ptr) * .00003937);
+}
+#endif
+#ifdef PNG_pHYs_SUPPORTED
+png_uint_32 PNGAPI
+png_get_pHYs_dpi(png_const_structp png_ptr, png_const_infop info_ptr,
+    png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type)
+{
+   png_uint_32 retval = 0;
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
+   {
+      png_debug1(1, "in %s retrieval function", "pHYs");
+      if (res_x != NULL)
+      {
+         *res_x = info_ptr->x_pixels_per_unit;
+         retval |= PNG_INFO_pHYs;
+      }
+      if (res_y != NULL)
+      {
+         *res_y = info_ptr->y_pixels_per_unit;
+         retval |= PNG_INFO_pHYs;
+      }
+      if (unit_type != NULL)
+      {
+         *unit_type = (int)info_ptr->phys_unit_type;
+         retval |= PNG_INFO_pHYs;
+         if (*unit_type == 1)
+         {
+            if (res_x != NULL) *res_x = (png_uint_32)(*res_x * .0254 + .50);
+            if (res_y != NULL) *res_y = (png_uint_32)(*res_y * .0254 + .50);
+         }
+      }
+   }
+   return (retval);
+}
+#endif /* PNG_pHYs_SUPPORTED */
+#endif  /* PNG_INCH_CONVERSIONS_SUPPORTED */
+/* png_get_channels really belongs in here, too, but it's been around longer */
+#endif  /* PNG_EASY_ACCESS_SUPPORTED */
+png_byte PNGAPI
+png_get_channels(png_const_structp png_ptr, png_const_infop info_ptr)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+      return(info_ptr->channels);
+   return (0);
+}
+png_const_bytep PNGAPI
+png_get_signature(png_const_structp png_ptr, png_infop info_ptr)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+      return(info_ptr->signature);
+   return (NULL);
+}
+#ifdef PNG_bKGD_SUPPORTED
+png_uint_32 PNGAPI
+png_get_bKGD(png_const_structp png_ptr, png_infop info_ptr,
+   png_color_16p *background)
+{
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_bKGD)
+       && background != NULL)
+   {
+      png_debug1(1, "in %s retrieval function", "bKGD");
+      *background = &(info_ptr->background);
+      return (PNG_INFO_bKGD);
+   }
+   return (0);
+}
+#endif
+#ifdef PNG_cHRM_SUPPORTED
+/* The XYZ APIs were added in 1.5.5 to take advantage of the code added at the
+ * same time to correct the rgb grayscale coefficient defaults obtained from the
+ * cHRM chunk in 1.5.4
+ */
+png_uint_32 PNGFAPI
+png_get_cHRM_XYZ_fixed(png_structp png_ptr, png_const_infop info_ptr,
+    png_fixed_point *int_red_X, png_fixed_point *int_red_Y,
+    png_fixed_point *int_red_Z, png_fixed_point *int_green_X,
+    png_fixed_point *int_green_Y, png_fixed_point *int_green_Z,
+    png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y,
+    png_fixed_point *int_blue_Z)
+{
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM))
+   {
+      png_xy xy;
+      png_XYZ XYZ;
+      png_debug1(1, "in %s retrieval function", "cHRM_XYZ");
+      xy.whitex = info_ptr->x_white;
+      xy.whitey = info_ptr->y_white;
+      xy.redx = info_ptr->x_red;
+      xy.redy = info_ptr->y_red;
+      xy.greenx = info_ptr->x_green;
+      xy.greeny = info_ptr->y_green;
+      xy.bluex = info_ptr->x_blue;
+      xy.bluey = info_ptr->y_blue;
+      /* The *_checked function handles error reporting, so just return 0 if
+       * there is a failure here.
+       */
+      if (png_XYZ_from_xy_checked(png_ptr, &XYZ, xy))
+      {
+         if (int_red_X != NULL)
+            *int_red_X = XYZ.redX;
+         if (int_red_Y != NULL)
+            *int_red_Y = XYZ.redY;
+         if (int_red_Z != NULL)
+            *int_red_Z = XYZ.redZ;
+         if (int_green_X != NULL)
+            *int_green_X = XYZ.greenX;
+         if (int_green_Y != NULL)
+            *int_green_Y = XYZ.greenY;
+         if (int_green_Z != NULL)
+            *int_green_Z = XYZ.greenZ;
+         if (int_blue_X != NULL)
+            *int_blue_X = XYZ.blueX;
+         if (int_blue_Y != NULL)
+            *int_blue_Y = XYZ.blueY;
+         if (int_blue_Z != NULL)
+            *int_blue_Z = XYZ.blueZ;
+         return (PNG_INFO_cHRM);
+      }
+   }
+   return (0);
+}
+#  ifdef PNG_FLOATING_POINT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_cHRM(png_const_structp png_ptr, png_const_infop info_ptr,
+    double *white_x, double *white_y, double *red_x, double *red_y,
+    double *green_x, double *green_y, double *blue_x, double *blue_y)
+{
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM))
+   {
+      png_debug1(1, "in %s retrieval function", "cHRM");
+      if (white_x != NULL)
+         *white_x = png_float(png_ptr, info_ptr->x_white, "cHRM white X");
+      if (white_y != NULL)
+         *white_y = png_float(png_ptr, info_ptr->y_white, "cHRM white Y");
+      if (red_x != NULL)
+         *red_x = png_float(png_ptr, info_ptr->x_red, "cHRM red X");
+      if (red_y != NULL)
+         *red_y = png_float(png_ptr, info_ptr->y_red, "cHRM red Y");
+      if (green_x != NULL)
+         *green_x = png_float(png_ptr, info_ptr->x_green, "cHRM green X");
+      if (green_y != NULL)
+         *green_y = png_float(png_ptr, info_ptr->y_green, "cHRM green Y");
+      if (blue_x != NULL)
+         *blue_x = png_float(png_ptr, info_ptr->x_blue, "cHRM blue X");
+      if (blue_y != NULL)
+         *blue_y = png_float(png_ptr, info_ptr->y_blue, "cHRM blue Y");
+      return (PNG_INFO_cHRM);
+   }
+   return (0);
+}
+png_uint_32 PNGAPI
+png_get_cHRM_XYZ(png_structp png_ptr, png_const_infop info_ptr,
+   double *red_X, double *red_Y, double *red_Z, double *green_X,
+   double *green_Y, double *green_Z, double *blue_X, double *blue_Y,
+   double *blue_Z)
+{
+   png_XYZ XYZ;
+   if (png_get_cHRM_XYZ_fixed(png_ptr, info_ptr,
+      &XYZ.redX, &XYZ.redY, &XYZ.redZ, &XYZ.greenX, &XYZ.greenY, &XYZ.greenZ,
+      &XYZ.blueX, &XYZ.blueY, &XYZ.blueZ) & PNG_INFO_cHRM)
+   {
+      if (red_X != NULL)
+         *red_X = png_float(png_ptr, XYZ.redX, "cHRM red X");
+      if (red_Y != NULL)
+         *red_Y = png_float(png_ptr, XYZ.redY, "cHRM red Y");
+      if (red_Z != NULL)
+         *red_Z = png_float(png_ptr, XYZ.redZ, "cHRM red Z");
+      if (green_X != NULL)
+         *green_X = png_float(png_ptr, XYZ.greenX, "cHRM green X");
+      if (green_Y != NULL)
+         *green_Y = png_float(png_ptr, XYZ.greenY, "cHRM green Y");
+      if (green_Z != NULL)
+         *green_Z = png_float(png_ptr, XYZ.greenZ, "cHRM green Z");
+      if (blue_X != NULL)
+         *blue_X = png_float(png_ptr, XYZ.blueX, "cHRM blue X");
+      if (blue_Y != NULL)
+         *blue_Y = png_float(png_ptr, XYZ.blueY, "cHRM blue Y");
+      if (blue_Z != NULL)
+         *blue_Z = png_float(png_ptr, XYZ.blueZ, "cHRM blue Z");
+      return (PNG_INFO_cHRM);
+   }
+   return (0);
+}
+#  endif
+#  ifdef PNG_FIXED_POINT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_cHRM_fixed(png_const_structp png_ptr, png_const_infop info_ptr,
+    png_fixed_point *white_x, png_fixed_point *white_y, png_fixed_point *red_x,
+    png_fixed_point *red_y, png_fixed_point *green_x, png_fixed_point *green_y,
+    png_fixed_point *blue_x, png_fixed_point *blue_y)
+{
+   png_debug1(1, "in %s retrieval function", "cHRM");
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM))
+   {
+      if (white_x != NULL)
+         *white_x = info_ptr->x_white;
+      if (white_y != NULL)
+         *white_y = info_ptr->y_white;
+      if (red_x != NULL)
+         *red_x = info_ptr->x_red;
+      if (red_y != NULL)
+         *red_y = info_ptr->y_red;
+      if (green_x != NULL)
+         *green_x = info_ptr->x_green;
+      if (green_y != NULL)
+         *green_y = info_ptr->y_green;
+      if (blue_x != NULL)
+         *blue_x = info_ptr->x_blue;
+      if (blue_y != NULL)
+         *blue_y = info_ptr->y_blue;
+      return (PNG_INFO_cHRM);
+   }
+   return (0);
+}
+#  endif
+#endif
+#ifdef PNG_gAMA_SUPPORTED
+png_uint_32 PNGFAPI
+png_get_gAMA_fixed(png_const_structp png_ptr, png_const_infop info_ptr,
+    png_fixed_point *file_gamma)
+{
+   png_debug1(1, "in %s retrieval function", "gAMA");
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA)
+       && file_gamma != NULL)
+   {
+      *file_gamma = info_ptr->gamma;
+      return (PNG_INFO_gAMA);
+   }
+   return (0);
+}
+#  ifdef PNG_FLOATING_POINT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_gAMA(png_const_structp png_ptr, png_const_infop info_ptr,
+    double *file_gamma)
+{
+   png_fixed_point igamma;
+   png_uint_32 ok = png_get_gAMA_fixed(png_ptr, info_ptr, &igamma);
+   if (ok)
+      *file_gamma = png_float(png_ptr, igamma, "png_get_gAMA");
+   return ok;
+}
+#  endif
+#endif
+#ifdef PNG_sRGB_SUPPORTED
+png_uint_32 PNGAPI
+png_get_sRGB(png_const_structp png_ptr, png_const_infop info_ptr,
+    int *file_srgb_intent)
+{
+   png_debug1(1, "in %s retrieval function", "sRGB");
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB)
+       && file_srgb_intent != NULL)
+   {
+      *file_srgb_intent = (int)info_ptr->srgb_intent;
+      return (PNG_INFO_sRGB);
+   }
+   return (0);
+}
+#endif
+#ifdef PNG_iCCP_SUPPORTED
+png_uint_32 PNGAPI
+png_get_iCCP(png_const_structp png_ptr, png_const_infop info_ptr,
+    png_charpp name, int *compression_type,
+    png_bytepp profile, png_uint_32 *proflen)
+{
+   png_debug1(1, "in %s retrieval function", "iCCP");
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_iCCP)
+       && name != NULL && compression_type != NULL && profile != NULL &&
+                 proflen != NULL)
+   {
+      *name = info_ptr->iccp_name;
+      *profile = info_ptr->iccp_profile;
+      /* Compression_type is a dummy so the API won't have to change
+       * if we introduce multiple compression types later.
+       */
+      *proflen = info_ptr->iccp_proflen;
+      *compression_type = info_ptr->iccp_compression;
+      return (PNG_INFO_iCCP);
+   }
+   return (0);
+}
+#endif
+#ifdef PNG_sPLT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_sPLT(png_const_structp png_ptr, png_const_infop info_ptr,
+    png_sPLT_tpp spalettes)
+{
+   if (png_ptr != NULL && info_ptr != NULL && spalettes != NULL)
+   {
+      *spalettes = info_ptr->splt_palettes;
+      return ((png_uint_32)info_ptr->splt_palettes_num);
+   }
+   return (0);
+}
+#endif
+#ifdef PNG_hIST_SUPPORTED
+png_uint_32 PNGAPI
+png_get_hIST(png_const_structp png_ptr, png_const_infop info_ptr,
+    png_uint_16p *hist)
+{
+   png_debug1(1, "in %s retrieval function", "hIST");
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_hIST)
+       && hist != NULL)
+   {
+      *hist = info_ptr->hist;
+      return (PNG_INFO_hIST);
+   }
+   return (0);
+}
+#endif
+png_uint_32 PNGAPI
+png_get_IHDR(png_structp png_ptr, png_infop info_ptr,
+    png_uint_32 *width, png_uint_32 *height, int *bit_depth,
+    int *color_type, int *interlace_type, int *compression_type,
+    int *filter_type)
+{
+   png_debug1(1, "in %s retrieval function", "IHDR");
+   if (png_ptr == NULL || info_ptr == NULL || width == NULL ||
+       height == NULL || bit_depth == NULL || color_type == NULL)
+      return (0);
+   *width = info_ptr->width;
+   *height = info_ptr->height;
+   *bit_depth = info_ptr->bit_depth;
+   *color_type = info_ptr->color_type;
+   if (compression_type != NULL)
+      *compression_type = info_ptr->compression_type;
+   if (filter_type != NULL)
+      *filter_type = info_ptr->filter_type;
+   if (interlace_type != NULL)
+      *interlace_type = info_ptr->interlace_type;
+   /* This is redundant if we can be sure that the info_ptr values were all
+    * assigned in png_set_IHDR().  We do the check anyhow in case an
+    * application has ignored our advice not to mess with the members
+    * of info_ptr directly.
+    */
+   png_check_IHDR (png_ptr, info_ptr->width, info_ptr->height,
+       info_ptr->bit_depth, info_ptr->color_type, info_ptr->interlace_type,
+       info_ptr->compression_type, info_ptr->filter_type);
+   return (1);
+}
+#ifdef PNG_oFFs_SUPPORTED
+png_uint_32 PNGAPI
+png_get_oFFs(png_const_structp png_ptr, png_const_infop info_ptr,
+    png_int_32 *offset_x, png_int_32 *offset_y, int *unit_type)
+{
+   png_debug1(1, "in %s retrieval function", "oFFs");
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs)
+       && offset_x != NULL && offset_y != NULL && unit_type != NULL)
+   {
+      *offset_x = info_ptr->x_offset;
+      *offset_y = info_ptr->y_offset;
+      *unit_type = (int)info_ptr->offset_unit_type;
+      return (PNG_INFO_oFFs);
+   }
+   return (0);
+}
+#endif
+#ifdef PNG_pCAL_SUPPORTED
+png_uint_32 PNGAPI
+png_get_pCAL(png_const_structp png_ptr, png_const_infop info_ptr,
+    png_charp *purpose, png_int_32 *X0, png_int_32 *X1, int *type, int *nparams,
+    png_charp *units, png_charpp *params)
+{
+   png_debug1(1, "in %s retrieval function", "pCAL");
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pCAL)
+       && purpose != NULL && X0 != NULL && X1 != NULL && type != NULL &&
+       nparams != NULL && units != NULL && params != NULL)
+   {
+      *purpose = info_ptr->pcal_purpose;
+      *X0 = info_ptr->pcal_X0;
+      *X1 = info_ptr->pcal_X1;
+      *type = (int)info_ptr->pcal_type;
+      *nparams = (int)info_ptr->pcal_nparams;
+      *units = info_ptr->pcal_units;
+      *params = info_ptr->pcal_params;
+      return (PNG_INFO_pCAL);
+   }
+   return (0);
+}
+#endif
+#ifdef PNG_sCAL_SUPPORTED
+#  ifdef PNG_FIXED_POINT_SUPPORTED
+#    ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
+png_uint_32 PNGAPI
+png_get_sCAL_fixed(png_structp png_ptr, png_const_infop info_ptr,
+    int *unit, png_fixed_point *width, png_fixed_point *height)
+{
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_sCAL))
+   {
+      *unit = info_ptr->scal_unit;
+      /*TODO: make this work without FP support */
+      *width = png_fixed(png_ptr, atof(info_ptr->scal_s_width), "sCAL width");
+      *height = png_fixed(png_ptr, atof(info_ptr->scal_s_height),
+         "sCAL height");
+      return (PNG_INFO_sCAL);
+   }
+   return(0);
+}
+#    endif /* FLOATING_ARITHMETIC */
+#  endif /* FIXED_POINT */
+#  ifdef PNG_FLOATING_POINT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_sCAL(png_const_structp png_ptr, png_const_infop info_ptr,
+    int *unit, double *width, double *height)
+{
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_sCAL))
+   {
+      *unit = info_ptr->scal_unit;
+      *width = atof(info_ptr->scal_s_width);
+      *height = atof(info_ptr->scal_s_height);
+      return (PNG_INFO_sCAL);
+   }
+   return(0);
+}
+#  endif /* FLOATING POINT */
+png_uint_32 PNGAPI
+png_get_sCAL_s(png_const_structp png_ptr, png_const_infop info_ptr,
+    int *unit, png_charpp width, png_charpp height)
+{
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_sCAL))
+   {
+      *unit = info_ptr->scal_unit;
+      *width = info_ptr->scal_s_width;
+      *height = info_ptr->scal_s_height;
+      return (PNG_INFO_sCAL);
+   }
+   return(0);
+}
+#endif /* sCAL */
+#ifdef PNG_pHYs_SUPPORTED
+png_uint_32 PNGAPI
+png_get_pHYs(png_const_structp png_ptr, png_const_infop info_ptr,
+    png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type)
+{
+   png_uint_32 retval = 0;
+   png_debug1(1, "in %s retrieval function", "pHYs");
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_pHYs))
+   {
+      if (res_x != NULL)
+      {
+         *res_x = info_ptr->x_pixels_per_unit;
+         retval |= PNG_INFO_pHYs;
+      }
+      if (res_y != NULL)
+      {
+         *res_y = info_ptr->y_pixels_per_unit;
+         retval |= PNG_INFO_pHYs;
+      }
+      if (unit_type != NULL)
+      {
+         *unit_type = (int)info_ptr->phys_unit_type;
+         retval |= PNG_INFO_pHYs;
+      }
+   }
+   return (retval);
+}
+#endif /* pHYs */
+png_uint_32 PNGAPI
+png_get_PLTE(png_const_structp png_ptr, png_const_infop info_ptr,
+    png_colorp *palette, int *num_palette)
+{
+   png_debug1(1, "in %s retrieval function", "PLTE");
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_PLTE)
+       && palette != NULL)
+   {
+      *palette = info_ptr->palette;
+      *num_palette = info_ptr->num_palette;
+      png_debug1(3, "num_palette = %d", *num_palette);
+      return (PNG_INFO_PLTE);
+   }
+   return (0);
+}
+#ifdef PNG_sBIT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_sBIT(png_const_structp png_ptr, png_infop info_ptr,
+    png_color_8p *sig_bit)
+{
+   png_debug1(1, "in %s retrieval function", "sBIT");
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_sBIT)
+       && sig_bit != NULL)
+   {
+      *sig_bit = &(info_ptr->sig_bit);
+      return (PNG_INFO_sBIT);
+   }
+   return (0);
+}
+#endif
+#ifdef PNG_TEXT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_text(png_const_structp png_ptr, png_const_infop info_ptr,
+    png_textp *text_ptr, int *num_text)
+{
+   if (png_ptr != NULL && info_ptr != NULL && info_ptr->num_text > 0)
+   {
+      png_debug1(1, "in 0x%lx retrieval function",
+         (unsigned long)png_ptr->chunk_name);
+      if (text_ptr != NULL)
+         *text_ptr = info_ptr->text;
+      if (num_text != NULL)
+         *num_text = info_ptr->num_text;
+      return ((png_uint_32)info_ptr->num_text);
+   }
+   if (num_text != NULL)
+      *num_text = 0;
+   return(0);
+}
+#endif
+#ifdef PNG_tIME_SUPPORTED
+png_uint_32 PNGAPI
+png_get_tIME(png_const_structp png_ptr, png_infop info_ptr, png_timep *mod_time)
+{
+   png_debug1(1, "in %s retrieval function", "tIME");
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_tIME)
+       && mod_time != NULL)
+   {
+      *mod_time = &(info_ptr->mod_time);
+      return (PNG_INFO_tIME);
+   }
+   return (0);
+}
+#endif
+#ifdef PNG_tRNS_SUPPORTED
+png_uint_32 PNGAPI
+png_get_tRNS(png_const_structp png_ptr, png_infop info_ptr,
+    png_bytep *trans_alpha, int *num_trans, png_color_16p *trans_color)
+{
+   png_uint_32 retval = 0;
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS))
+   {
+      png_debug1(1, "in %s retrieval function", "tRNS");
+      if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+      {
+         if (trans_alpha != NULL)
+         {
+            *trans_alpha = info_ptr->trans_alpha;
+            retval |= PNG_INFO_tRNS;
+         }
+         if (trans_color != NULL)
+            *trans_color = &(info_ptr->trans_color);
+      }
+      else /* if (info_ptr->color_type != PNG_COLOR_TYPE_PALETTE) */
+      {
+         if (trans_color != NULL)
+         {
+            *trans_color = &(info_ptr->trans_color);
+            retval |= PNG_INFO_tRNS;
+         }
+         if (trans_alpha != NULL)
+            *trans_alpha = NULL;
+      }
+      if (num_trans != NULL)
+      {
+         *num_trans = info_ptr->num_trans;
+         retval |= PNG_INFO_tRNS;
+      }
+   }
+   return (retval);
+}
+#endif
+#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
+int PNGAPI
+png_get_unknown_chunks(png_const_structp png_ptr, png_const_infop info_ptr,
+    png_unknown_chunkpp unknowns)
+{
+   if (png_ptr != NULL && info_ptr != NULL && unknowns != NULL)
+   {
+      *unknowns = info_ptr->unknown_chunks;
+      return info_ptr->unknown_chunks_num;
+   }
+   return (0);
+}
+#endif
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+png_byte PNGAPI
+png_get_rgb_to_gray_status (png_const_structp png_ptr)
+{
+   return (png_byte)(png_ptr ? png_ptr->rgb_to_gray_status : 0);
+}
+#endif
+#ifdef PNG_USER_CHUNKS_SUPPORTED
+png_voidp PNGAPI
+png_get_user_chunk_ptr(png_const_structp png_ptr)
+{
+   return (png_ptr ? png_ptr->user_chunk_ptr : NULL);
+}
+#endif
+png_size_t PNGAPI
+png_get_compression_buffer_size(png_const_structp png_ptr)
+{
+   return (png_ptr ? png_ptr->zbuf_size : 0);
+}
+#ifdef PNG_SET_USER_LIMITS_SUPPORTED
+/* These functions were added to libpng 1.2.6 and were enabled
+ * by default in libpng-1.4.0 */
+png_uint_32 PNGAPI
+png_get_user_width_max (png_const_structp png_ptr)
+{
+   return (png_ptr ? png_ptr->user_width_max : 0);
+}
+png_uint_32 PNGAPI
+png_get_user_height_max (png_const_structp png_ptr)
+{
+   return (png_ptr ? png_ptr->user_height_max : 0);
+}
+/* This function was added to libpng 1.4.0 */
+png_uint_32 PNGAPI
+png_get_chunk_cache_max (png_const_structp png_ptr)
+{
+   return (png_ptr ? png_ptr->user_chunk_cache_max : 0);
+}
+/* This function was added to libpng 1.4.1 */
+png_alloc_size_t PNGAPI
+png_get_chunk_malloc_max (png_const_structp png_ptr)
+{
+   return (png_ptr ? png_ptr->user_chunk_malloc_max : 0);
+}
+#endif /* ?PNG_SET_USER_LIMITS_SUPPORTED */
+/* These functions were added to libpng 1.4.0 */
+#ifdef PNG_IO_STATE_SUPPORTED
+png_uint_32 PNGAPI
+png_get_io_state (png_structp png_ptr)
+{
+   return png_ptr->io_state;
+}
+png_uint_32 PNGAPI
+png_get_io_chunk_type (png_const_structp png_ptr)
+{
+   return png_ptr->chunk_name;
+}
+png_const_bytep PNGAPI
+png_get_io_chunk_name (png_structp png_ptr)
+{
+   PNG_CSTRING_FROM_CHUNK(png_ptr->io_chunk_string, png_ptr->chunk_name);
+   return png_ptr->io_chunk_string;
+}
+#endif /* ?PNG_IO_STATE_SUPPORTED */
+#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/pnginfo.h b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pnginfo.h
new file mode 100644
index 0000000..bbfb105
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pnginfo.h
@@ -0,0 +1,269 @@
+/* pnginfo.h - header file for PNG reference library
+ *
+ * Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * Last changed in libpng 1.5.0 [January 6, 2011]
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+ /* png_info is a structure that holds the information in a PNG file so
+ * that the application can find out the characteristics of the image.
+ * If you are reading the file, this structure will tell you what is
+ * in the PNG file.  If you are writing the file, fill in the information
+ * you want to put into the PNG file, using png_set_*() functions, then
+ * call png_write_info().
+ *
+ * The names chosen should be very close to the PNG specification, so
+ * consult that document for information about the meaning of each field.
+ *
+ * With libpng < 0.95, it was only possible to directly set and read the
+ * the values in the png_info_struct, which meant that the contents and
+ * order of the values had to remain fixed.  With libpng 0.95 and later,
+ * however, there are now functions that abstract the contents of
+ * png_info_struct from the application, so this makes it easier to use
+ * libpng with dynamic libraries, and even makes it possible to use
+ * libraries that don't have all of the libpng ancillary chunk-handing
+ * functionality.  In libpng-1.5.0 this was moved into a separate private
+ * file that is not visible to applications.
+ *
+ * The following members may have allocated storage attached that should be
+ * cleaned up before the structure is discarded: palette, trans, text,
+ * pcal_purpose, pcal_units, pcal_params, hist, iccp_name, iccp_profile,
+ * splt_palettes, scal_unit, row_pointers, and unknowns.   By default, these
+ * are automatically freed when the info structure is deallocated, if they were
+ * allocated internally by libpng.  This behavior can be changed by means
+ * of the png_data_freer() function.
+ *
+ * More allocation details: all the chunk-reading functions that
+ * change these members go through the corresponding png_set_*
+ * functions.  A function to clear these members is available: see
+ * png_free_data().  The png_set_* functions do not depend on being
+ * able to point info structure members to any of the storage they are
+ * passed (they make their own copies), EXCEPT that the png_set_text
+ * functions use the same storage passed to them in the text_ptr or
+ * itxt_ptr structure argument, and the png_set_rows and png_set_unknowns
+ * functions do not make their own copies.
+ */
+#ifndef PNGINFO_H
+#define PNGINFO_H
+struct png_info_def
+{
+   /* the following are necessary for every PNG file */
+   png_uint_32 width;  /* width of image in pixels (from IHDR) */
+   png_uint_32 height; /* height of image in pixels (from IHDR) */
+   png_uint_32 valid;  /* valid chunk data (see PNG_INFO_ below) */
+   png_size_t rowbytes; /* bytes needed to hold an untransformed row */
+   png_colorp palette;      /* array of color values (valid & PNG_INFO_PLTE) */
+   png_uint_16 num_palette; /* number of color entries in "palette" (PLTE) */
+   png_uint_16 num_trans;   /* number of transparent palette color (tRNS) */
+   png_byte bit_depth;      /* 1, 2, 4, 8, or 16 bits/channel (from IHDR) */
+   png_byte color_type;     /* see PNG_COLOR_TYPE_ below (from IHDR) */
+   /* The following three should have been named *_method not *_type */
+   png_byte compression_type; /* must be PNG_COMPRESSION_TYPE_BASE (IHDR) */
+   png_byte filter_type;    /* must be PNG_FILTER_TYPE_BASE (from IHDR) */
+   png_byte interlace_type; /* One of PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
+   /* The following is informational only on read, and not used on writes. */
+   png_byte channels;       /* number of data channels per pixel (1, 2, 3, 4) */
+   png_byte pixel_depth;    /* number of bits per pixel */
+   png_byte spare_byte;     /* to align the data, and for future use */
+   png_byte signature[8];   /* magic bytes read by libpng from start of file */
+   /* The rest of the data is optional.  If you are reading, check the
+    * valid field to see if the information in these are valid.  If you
+    * are writing, set the valid field to those chunks you want written,
+    * and initialize the appropriate fields below.
+    */
+#if defined(PNG_gAMA_SUPPORTED)
+   /* The gAMA chunk describes the gamma characteristics of the system
+    * on which the image was created, normally in the range [1.0, 2.5].
+    * Data is valid if (valid & PNG_INFO_gAMA) is non-zero.
+    */
+   png_fixed_point gamma;
+#endif
+#ifdef PNG_sRGB_SUPPORTED
+    /* GR-P, 0.96a */
+    /* Data valid if (valid & PNG_INFO_sRGB) non-zero. */
+   png_byte srgb_intent; /* sRGB rendering intent [0, 1, 2, or 3] */
+#endif
+#ifdef PNG_TEXT_SUPPORTED
+   /* The tEXt, and zTXt chunks contain human-readable textual data in
+    * uncompressed, compressed, and optionally compressed forms, respectively.
+    * The data in "text" is an array of pointers to uncompressed,
+    * null-terminated C strings. Each chunk has a keyword that describes the
+    * textual data contained in that chunk.  Keywords are not required to be
+    * unique, and the text string may be empty.  Any number of text chunks may
+    * be in an image.
+    */
+   int num_text; /* number of comments read or comments to write */
+   int max_text; /* current size of text array */
+   png_textp text; /* array of comments read or comments to write */
+#endif /* PNG_TEXT_SUPPORTED */
+#ifdef PNG_tIME_SUPPORTED
+   /* The tIME chunk holds the last time the displayed image data was
+    * modified.  See the png_time struct for the contents of this struct.
+    */
+   png_time mod_time;
+#endif
+#ifdef PNG_sBIT_SUPPORTED
+   /* The sBIT chunk specifies the number of significant high-order bits
+    * in the pixel data.  Values are in the range [1, bit_depth], and are
+    * only specified for the channels in the pixel data.  The contents of
+    * the low-order bits is not specified.  Data is valid if
+    * (valid & PNG_INFO_sBIT) is non-zero.
+    */
+   png_color_8 sig_bit; /* significant bits in color channels */
+#endif
+#if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_EXPAND_SUPPORTED) || \
+defined(PNG_READ_BACKGROUND_SUPPORTED)
+   /* The tRNS chunk supplies transparency data for paletted images and
+    * other image types that don't need a full alpha channel.  There are
+    * "num_trans" transparency values for a paletted image, stored in the
+    * same order as the palette colors, starting from index 0.  Values
+    * for the data are in the range [0, 255], ranging from fully transparent
+    * to fully opaque, respectively.  For non-paletted images, there is a
+    * single color specified that should be treated as fully transparent.
+    * Data is valid if (valid & PNG_INFO_tRNS) is non-zero.
+    */
+   png_bytep trans_alpha;    /* alpha values for paletted image */
+   png_color_16 trans_color; /* transparent color for non-palette image */
+#endif
+#if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+   /* The bKGD chunk gives the suggested image background color if the
+    * display program does not have its own background color and the image
+    * is needs to composited onto a background before display.  The colors
+    * in "background" are normally in the same color space/depth as the
+    * pixel data.  Data is valid if (valid & PNG_INFO_bKGD) is non-zero.
+    */
+   png_color_16 background;
+#endif
+#ifdef PNG_oFFs_SUPPORTED
+   /* The oFFs chunk gives the offset in "offset_unit_type" units rightwards
+    * and downwards from the top-left corner of the display, page, or other
+    * application-specific co-ordinate space.  See the PNG_OFFSET_ defines
+    * below for the unit types.  Valid if (valid & PNG_INFO_oFFs) non-zero.
+    */
+   png_int_32 x_offset; /* x offset on page */
+   png_int_32 y_offset; /* y offset on page */
+   png_byte offset_unit_type; /* offset units type */
+#endif
+#ifdef PNG_pHYs_SUPPORTED
+   /* The pHYs chunk gives the physical pixel density of the image for
+    * display or printing in "phys_unit_type" units (see PNG_RESOLUTION_
+    * defines below).  Data is valid if (valid & PNG_INFO_pHYs) is non-zero.
+    */
+   png_uint_32 x_pixels_per_unit; /* horizontal pixel density */
+   png_uint_32 y_pixels_per_unit; /* vertical pixel density */
+   png_byte phys_unit_type; /* resolution type (see PNG_RESOLUTION_ below) */
+#endif
+#ifdef PNG_hIST_SUPPORTED
+   /* The hIST chunk contains the relative frequency or importance of the
+    * various palette entries, so that a viewer can intelligently select a
+    * reduced-color palette, if required.  Data is an array of "num_palette"
+    * values in the range [0,65535]. Data valid if (valid & PNG_INFO_hIST)
+    * is non-zero.
+    */
+   png_uint_16p hist;
+#endif
+#ifdef PNG_cHRM_SUPPORTED
+   /* The cHRM chunk describes the CIE color characteristics of the monitor
+    * on which the PNG was created.  This data allows the viewer to do gamut
+    * mapping of the input image to ensure that the viewer sees the same
+    * colors in the image as the creator.  Values are in the range
+    * [0.0, 0.8].  Data valid if (valid & PNG_INFO_cHRM) non-zero.
+    */
+   png_fixed_point x_white;
+   png_fixed_point y_white;
+   png_fixed_point x_red;
+   png_fixed_point y_red;
+   png_fixed_point x_green;
+   png_fixed_point y_green;
+   png_fixed_point x_blue;
+   png_fixed_point y_blue;
+#endif
+#ifdef PNG_pCAL_SUPPORTED
+   /* The pCAL chunk describes a transformation between the stored pixel
+    * values and original physical data values used to create the image.
+    * The integer range [0, 2^bit_depth - 1] maps to the floating-point
+    * range given by [pcal_X0, pcal_X1], and are further transformed by a
+    * (possibly non-linear) transformation function given by "pcal_type"
+    * and "pcal_params" into "pcal_units".  Please see the PNG_EQUATION_
+    * defines below, and the PNG-Group's PNG extensions document for a
+    * complete description of the transformations and how they should be
+    * implemented, and for a description of the ASCII parameter strings.
+    * Data values are valid if (valid & PNG_INFO_pCAL) non-zero.
+    */
+   png_charp pcal_purpose;  /* pCAL chunk description string */
+   png_int_32 pcal_X0;      /* minimum value */
+   png_int_32 pcal_X1;      /* maximum value */
+   png_charp pcal_units;    /* Latin-1 string giving physical units */
+   png_charpp pcal_params;  /* ASCII strings containing parameter values */
+   png_byte pcal_type;      /* equation type (see PNG_EQUATION_ below) */
+   png_byte pcal_nparams;   /* number of parameters given in pcal_params */
+#endif
+/* New members added in libpng-1.0.6 */
+   png_uint_32 free_me;     /* flags items libpng is responsible for freeing */
+#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) || \
+ defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
+   /* Storage for unknown chunks that the library doesn't recognize. */
+   png_unknown_chunkp unknown_chunks;
+   int unknown_chunks_num;
+#endif
+#ifdef PNG_iCCP_SUPPORTED
+   /* iCCP chunk data. */
+   png_charp iccp_name;     /* profile name */
+   png_bytep iccp_profile;  /* International Color Consortium profile data */
+   png_uint_32 iccp_proflen;  /* ICC profile data length */
+   png_byte iccp_compression; /* Always zero */
+#endif
+#ifdef PNG_sPLT_SUPPORTED
+   /* Data on sPLT chunks (there may be more than one). */
+   png_sPLT_tp splt_palettes;
+   png_uint_32 splt_palettes_num;
+#endif
+#ifdef PNG_sCAL_SUPPORTED
+   /* The sCAL chunk describes the actual physical dimensions of the
+    * subject matter of the graphic.  The chunk contains a unit specification
+    * a byte value, and two ASCII strings representing floating-point
+    * values.  The values are width and height corresponsing to one pixel
+    * in the image.  Data values are valid if (valid & PNG_INFO_sCAL) is
+    * non-zero.
+    */
+   png_byte scal_unit;         /* unit of physical scale */
+   png_charp scal_s_width;     /* string containing height */
+   png_charp scal_s_height;    /* string containing width */
+#endif
+#ifdef PNG_INFO_IMAGE_SUPPORTED
+   /* Memory has been allocated if (valid & PNG_ALLOCATED_INFO_ROWS)
+      non-zero */
+   /* Data valid if (valid & PNG_INFO_IDAT) non-zero */
+   png_bytepp row_pointers;        /* the image bits */
+#endif
+};
+#endif /* PNGINFO_H */
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/pnglibconf.h b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pnglibconf.h
new file mode 100644
index 0000000..d207232
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pnglibconf.h
@@ -0,0 +1,187 @@
+/* libpng STANDARD API DEFINITION */
+/* pnglibconf.h - library build configuration */
+/* libpng version 1.5.4 - last changed on June 22, 2011 */
+/* Copyright (c) 1998-2011 Glenn Randers-Pehrson */
+/* This code is released under the libpng license. */
+/* For conditions of distribution and use, see the disclaimer */
+/* and license in png.h */
+/* pnglibconf.h */
+/* Derived from: scripts/pnglibconf.dfa */
+/* If you edit this file by hand you must obey the rules expressed in */
+/* pnglibconf.dfa with respect to the dependencies between the following */
+/* symbols.  It is much better to generate a new file using */
+/* scripts/libpngconf.mak */
+#ifndef PNGLCONF_H
+#define PNGLCONF_H
+/* settings */
+#define PNG_API_RULE 0
+#define PNG_CALLOC_SUPPORTED
+#define PNG_COST_SHIFT 3
+#define PNG_DEFAULT_READ_MACROS 1
+#define PNG_GAMMA_THRESHOLD_FIXED 5000
+#define PNG_MAX_GAMMA_8 11
+#define PNG_QUANTIZE_BLUE_BITS 5
+#define PNG_QUANTIZE_GREEN_BITS 5
+#define PNG_QUANTIZE_RED_BITS 5
+#define PNG_sCAL_PRECISION 5
+#define PNG_USER_CHUNK_CACHE_MAX 0
+#define PNG_USER_CHUNK_MALLOC_MAX 0
+#define PNG_USER_HEIGHT_MAX 1000000
+#define PNG_USER_WIDTH_MAX 1000000
+#define PNG_WEIGHT_SHIFT 8
+#define PNG_ZBUF_SIZE 8192
+/* end of settings */
+/* options */
+#define PNG_16BIT_SUPPORTED
+#define PNG_ALIGN_MEMORY_SUPPORTED
+#define PNG_BENIGN_ERRORS_SUPPORTED
+#define PNG_bKGD_SUPPORTED
+#define PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED
+#define PNG_CHECK_cHRM_SUPPORTED
+#define PNG_cHRM_SUPPORTED
+#define PNG_CONSOLE_IO_SUPPORTED
+#define PNG_CONVERT_tIME_SUPPORTED
+#define PNG_EASY_ACCESS_SUPPORTED
+/*#undef PNG_ERROR_NUMBERS_SUPPORTED*/
+#define PNG_ERROR_TEXT_SUPPORTED
+#define PNG_FIXED_POINT_SUPPORTED
+#define PNG_FLOATING_ARITHMETIC_SUPPORTED
+#define PNG_FLOATING_POINT_SUPPORTED
+#define PNG_gAMA_SUPPORTED
+#define PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+#define PNG_hIST_SUPPORTED
+#define PNG_iCCP_SUPPORTED
+#define PNG_INCH_CONVERSIONS_SUPPORTED
+#define PNG_INFO_IMAGE_SUPPORTED
+#define PNG_IO_STATE_SUPPORTED
+#define PNG_iTXt_SUPPORTED
+#define PNG_MNG_FEATURES_SUPPORTED
+#define PNG_oFFs_SUPPORTED
+#define PNG_pCAL_SUPPORTED
+#define PNG_pHYs_SUPPORTED
+#define PNG_POINTER_INDEXING_SUPPORTED
+#define PNG_PROGRESSIVE_READ_SUPPORTED
+#define PNG_READ_16BIT_SUPPORTED
+#define PNG_READ_ALPHA_MODE_SUPPORTED
+#define PNG_READ_ANCILLARY_CHUNKS_SUPPORTED
+#define PNG_READ_BACKGROUND_SUPPORTED
+#define PNG_READ_BGR_SUPPORTED
+#define PNG_READ_bKGD_SUPPORTED
+#define PNG_READ_cHRM_SUPPORTED
+#define PNG_READ_COMPOSITE_NODIV_SUPPORTED
+#define PNG_READ_COMPRESSED_TEXT_SUPPORTED
+#define PNG_READ_EXPAND_16_SUPPORTED
+#define PNG_READ_EXPAND_SUPPORTED
+#define PNG_READ_FILLER_SUPPORTED
+#define PNG_READ_gAMA_SUPPORTED
+#define PNG_READ_GAMMA_SUPPORTED
+#define PNG_READ_GRAY_TO_RGB_SUPPORTED
+#define PNG_READ_hIST_SUPPORTED
+#define PNG_READ_iCCP_SUPPORTED
+#define PNG_READ_INTERLACING_SUPPORTED
+#define PNG_READ_INT_FUNCTIONS_SUPPORTED
+#define PNG_READ_INVERT_ALPHA_SUPPORTED
+#define PNG_READ_INVERT_SUPPORTED
+#define PNG_READ_iTXt_SUPPORTED
+#define PNG_READ_oFFs_SUPPORTED
+#define PNG_READ_OPT_PLTE_SUPPORTED
+#define PNG_READ_PACK_SUPPORTED
+#define PNG_READ_PACKSWAP_SUPPORTED
+#define PNG_READ_pCAL_SUPPORTED
+#define PNG_READ_pHYs_SUPPORTED
+#define PNG_READ_QUANTIZE_SUPPORTED
+#define PNG_READ_RGB_TO_GRAY_SUPPORTED
+#define PNG_READ_sBIT_SUPPORTED
+#define PNG_READ_SCALE_16_TO_8_SUPPORTED
+#define PNG_READ_sCAL_SUPPORTED
+#define PNG_READ_SHIFT_SUPPORTED
+#define PNG_READ_sPLT_SUPPORTED
+#define PNG_READ_sRGB_SUPPORTED
+#define PNG_READ_STRIP_16_TO_8_SUPPORTED
+#define PNG_READ_STRIP_ALPHA_SUPPORTED
+#define PNG_READ_SUPPORTED
+#define PNG_READ_SWAP_ALPHA_SUPPORTED
+#define PNG_READ_SWAP_SUPPORTED
+#define PNG_READ_tEXt_SUPPORTED
+#define PNG_READ_TEXT_SUPPORTED
+#define PNG_READ_tIME_SUPPORTED
+#define PNG_READ_TRANSFORMS_SUPPORTED
+#define PNG_READ_tRNS_SUPPORTED
+#define PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+#define PNG_READ_USER_CHUNKS_SUPPORTED
+#define PNG_READ_USER_TRANSFORM_SUPPORTED
+#define PNG_READ_zTXt_SUPPORTED
+#define PNG_SAVE_INT_32_SUPPORTED
+#define PNG_sBIT_SUPPORTED
+#define PNG_sCAL_SUPPORTED
+#define PNG_SEQUENTIAL_READ_SUPPORTED
+#define PNG_SET_CHUNK_CACHE_LIMIT_SUPPORTED
+#define PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED
+#define PNG_SETJMP_SUPPORTED
+#define PNG_SET_USER_LIMITS_SUPPORTED
+#define PNG_sPLT_SUPPORTED
+#define PNG_sRGB_SUPPORTED
+#define PNG_STDIO_SUPPORTED
+#define PNG_tEXt_SUPPORTED
+#define PNG_TEXT_SUPPORTED
+#define PNG_TIME_RFC1123_SUPPORTED
+#define PNG_tIME_SUPPORTED
+#define PNG_tRNS_SUPPORTED
+#define PNG_UNKNOWN_CHUNKS_SUPPORTED
+#define PNG_USER_CHUNKS_SUPPORTED
+#define PNG_USER_LIMITS_SUPPORTED
+#define PNG_USER_MEM_SUPPORTED
+#define PNG_USER_TRANSFORM_INFO_SUPPORTED
+#define PNG_USER_TRANSFORM_PTR_SUPPORTED
+#define PNG_WARNINGS_SUPPORTED
+#define PNG_WRITE_16BIT_SUPPORTED
+#define PNG_WRITE_ANCILLARY_CHUNKS_SUPPORTED
+#define PNG_WRITE_BGR_SUPPORTED
+#define PNG_WRITE_bKGD_SUPPORTED
+#define PNG_WRITE_cHRM_SUPPORTED
+#define PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
+#define PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
+#define PNG_WRITE_FILLER_SUPPORTED
+#define PNG_WRITE_FILTER_SUPPORTED
+#define PNG_WRITE_FLUSH_SUPPORTED
+#define PNG_WRITE_gAMA_SUPPORTED
+#define PNG_WRITE_hIST_SUPPORTED
+#define PNG_WRITE_iCCP_SUPPORTED
+#define PNG_WRITE_INTERLACING_SUPPORTED
+#define PNG_WRITE_INT_FUNCTIONS_SUPPORTED
+#define PNG_WRITE_INVERT_ALPHA_SUPPORTED
+#define PNG_WRITE_INVERT_SUPPORTED
+#define PNG_WRITE_iTXt_SUPPORTED
+#define PNG_WRITE_oFFs_SUPPORTED
+#define PNG_WRITE_OPTIMIZE_CMF_SUPPORTED
+#define PNG_WRITE_PACK_SUPPORTED
+#define PNG_WRITE_PACKSWAP_SUPPORTED
+#define PNG_WRITE_pCAL_SUPPORTED
+#define PNG_WRITE_pHYs_SUPPORTED
+#define PNG_WRITE_sBIT_SUPPORTED
+#define PNG_WRITE_sCAL_SUPPORTED
+#define PNG_WRITE_SHIFT_SUPPORTED
+#define PNG_WRITE_sPLT_SUPPORTED
+#define PNG_WRITE_sRGB_SUPPORTED
+#define PNG_WRITE_SUPPORTED
+#define PNG_WRITE_SWAP_ALPHA_SUPPORTED
+#define PNG_WRITE_SWAP_SUPPORTED
+#define PNG_WRITE_tEXt_SUPPORTED
+#define PNG_WRITE_TEXT_SUPPORTED
+#define PNG_WRITE_tIME_SUPPORTED
+#define PNG_WRITE_TRANSFORMS_SUPPORTED
+#define PNG_WRITE_tRNS_SUPPORTED
+#define PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+#define PNG_WRITE_USER_TRANSFORM_SUPPORTED
+#define PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+#define PNG_WRITE_zTXt_SUPPORTED
+#define PNG_zTXt_SUPPORTED
+/* end of options */
+#endif /* PNGLCONF_H */
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngmem.c b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngmem.c
new file mode 100644
index 0000000..25b5c73
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngmem.c
@@ -0,0 +1,667 @@
+/* pngmem.c - stub functions for memory allocation
+ *
+ * Last changed in libpng 1.5.7 [December 15, 2011]
+ * Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * This file provides a location for all memory allocation.  Users who
+ * need special memory handling are expected to supply replacement
+ * functions for png_malloc() and png_free(), and to use
+ * png_create_read_struct_2() and png_create_write_struct_2() to
+ * identify the replacement functions.
+ */
+#include "pngpriv.h"
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+/* Borland DOS special memory handler */
+#if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
+/* If you change this, be sure to change the one in png.h also */
+/* Allocate memory for a png_struct.  The malloc and memset can be replaced
+   by a single call to calloc() if this is thought to improve performance. */
+PNG_FUNCTION(png_voidp /* PRIVATE */,
+png_create_struct,(int type),PNG_ALLOCATED)
+{
+#  ifdef PNG_USER_MEM_SUPPORTED
+   return (png_create_struct_2(type, NULL, NULL));
+}
+/* Alternate version of png_create_struct, for use with user-defined malloc. */
+PNG_FUNCTION(png_voidp /* PRIVATE */,
+png_create_struct_2,(int type, png_malloc_ptr malloc_fn, png_voidp mem_ptr),
+   PNG_ALLOCATED)
+{
+#  endif /* PNG_USER_MEM_SUPPORTED */
+   png_size_t size;
+   png_voidp struct_ptr;
+   if (type == PNG_STRUCT_INFO)
+      size = png_sizeof(png_info);
+   else if (type == PNG_STRUCT_PNG)
+      size = png_sizeof(png_struct);
+   else
+      return (png_get_copyright(NULL));
+#  ifdef PNG_USER_MEM_SUPPORTED
+   if (malloc_fn != NULL)
+   {
+      png_struct dummy_struct;
+      memset(&dummy_struct, 0, sizeof dummy_struct);
+      dummy_struct.mem_ptr=mem_ptr;
+      struct_ptr = (*(malloc_fn))(&dummy_struct, (png_alloc_size_t)size);
+   }
+   else
+#  endif /* PNG_USER_MEM_SUPPORTED */
+   struct_ptr = (png_voidp)farmalloc(size);
+   if (struct_ptr != NULL)
+      png_memset(struct_ptr, 0, size);
+   return (struct_ptr);
+}
+/* Free memory allocated by a png_create_struct() call */
+void /* PRIVATE */
+png_destroy_struct(png_voidp struct_ptr)
+{
+#  ifdef PNG_USER_MEM_SUPPORTED
+   png_destroy_struct_2(struct_ptr, NULL, NULL);
+}
+/* Free memory allocated by a png_create_struct() call */
+void /* PRIVATE */
+png_destroy_struct_2(png_voidp struct_ptr, png_free_ptr free_fn,
+    png_voidp mem_ptr)
+{
+#  endif
+   if (struct_ptr != NULL)
+   {
+#  ifdef PNG_USER_MEM_SUPPORTED
+      if (free_fn != NULL)
+      {
+         png_struct dummy_struct;
+         memset(&dummy_struct, 0, sizeof dummy_struct);
+         dummy_struct.mem_ptr=mem_ptr;
+         (*(free_fn))(&dummy_struct, struct_ptr);
+         return;
+      }
+#  endif /* PNG_USER_MEM_SUPPORTED */
+      farfree (struct_ptr);
+   }
+}
+/* Allocate memory.  For reasonable files, size should never exceed
+ * 64K.  However, zlib may allocate more then 64K if you don't tell
+ * it not to.  See zconf.h and png.h for more information. zlib does
+ * need to allocate exactly 64K, so whatever you call here must
+ * have the ability to do that.
+ *
+ * Borland seems to have a problem in DOS mode for exactly 64K.
+ * It gives you a segment with an offset of 8 (perhaps to store its
+ * memory stuff).  zlib doesn't like this at all, so we have to
+ * detect and deal with it.  This code should not be needed in
+ * Windows or OS/2 modes, and only in 16 bit mode.  This code has
+ * been updated by Alexander Lehmann for version 0.89 to waste less
+ * memory.
+ *
+ * Note that we can't use png_size_t for the "size" declaration,
+ * since on some systems a png_size_t is a 16-bit quantity, and as a
+ * result, we would be truncating potentially larger memory requests
+ * (which should cause a fatal error) and introducing major problems.
+ */
+PNG_FUNCTION(png_voidp,PNGAPI
+png_calloc,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
+{
+   png_voidp ret;
+   ret = (png_malloc(png_ptr, size));
+   if (ret != NULL)
+      png_memset(ret,0,(png_size_t)size);
+   return (ret);
+}
+PNG_FUNCTION(png_voidp,PNGAPI
+png_malloc,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
+{
+   png_voidp ret;
+   if (png_ptr == NULL || size == 0)
+      return (NULL);
+#  ifdef PNG_USER_MEM_SUPPORTED
+   if (png_ptr->malloc_fn != NULL)
+      ret = ((png_voidp)(*(png_ptr->malloc_fn))(png_ptr, size));
+   else
+      ret = (png_malloc_default(png_ptr, size));
+   if (ret == NULL && (png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
+       png_error(png_ptr, "Out of memory");
+   return (ret);
+}
+PNG_FUNCTION(png_voidp,PNGAPI
+png_malloc_default,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
+{
+   png_voidp ret;
+#  endif /* PNG_USER_MEM_SUPPORTED */
+   if (png_ptr == NULL || size == 0)
+      return (NULL);
+#  ifdef PNG_MAX_MALLOC_64K
+   if (size > (png_uint_32)65536L)
+   {
+      png_warning(png_ptr, "Cannot Allocate > 64K");
+      ret = NULL;
+   }
+   else
+#  endif
+   if (size != (size_t)size)
+      ret = NULL;
+   else if (size == (png_uint_32)65536L)
+   {
+      if (png_ptr->offset_table == NULL)
+      {
+         /* Try to see if we need to do any of this fancy stuff */
+         ret = farmalloc(size);
+         if (ret == NULL || ((png_size_t)ret & 0xffff))
+         {
+            int num_blocks;
+            png_uint_32 total_size;
+            png_bytep table;
+            int i, mem_level, window_bits;
+            png_byte huge * hptr;
+            int window_bits
+            if (ret != NULL)
+            {
+               farfree(ret);
+               ret = NULL;
+            }
+            window_bits =
+                png_ptr->zlib_window_bits >= png_ptr->zlib_text_window_bits ?
+                png_ptr->zlib_window_bits : png_ptr->zlib_text_window_bits;
+            if (window_bits > 14)
+               num_blocks = (int)(1 << (window_bits - 14));
+            else
+               num_blocks = 1;
+            mem_level =
+                png_ptr->zlib_mem_level >= png_ptr->zlib_text_mem_level ?
+                png_ptr->zlib_mem_level : png_ptr->zlib_text_mem_level;
+            if (mem_level >= 7)
+               num_blocks += (int)(1 << (mem_level - 7));
+            else
+               num_blocks++;
+            total_size = ((png_uint_32)65536L) * (png_uint_32)num_blocks+16;
+            table = farmalloc(total_size);
+            if (table == NULL)
+            {
+#  ifndef PNG_USER_MEM_SUPPORTED
+               if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
+                  png_error(png_ptr, "Out Of Memory"); /* Note "O", "M" */
+               else
+                  png_warning(png_ptr, "Out Of Memory");
+#  endif
+               return (NULL);
+            }
+            if ((png_size_t)table & 0xfff0)
+            {
+#  ifndef PNG_USER_MEM_SUPPORTED
+               if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
+                  png_error(png_ptr,
+                    "Farmalloc didn't return normalized pointer");
+               else
+                  png_warning(png_ptr,
+                    "Farmalloc didn't return normalized pointer");
+#  endif
+               return (NULL);
+            }
+            png_ptr->offset_table = table;
+            png_ptr->offset_table_ptr = farmalloc(num_blocks *
+               png_sizeof(png_bytep));
+            if (png_ptr->offset_table_ptr == NULL)
+            {
+#  ifndef PNG_USER_MEM_SUPPORTED
+               if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
+                  png_error(png_ptr, "Out Of memory"); /* Note "O", "m" */
+               else
+                  png_warning(png_ptr, "Out Of memory");
+#  endif
+               return (NULL);
+            }
+            hptr = (png_byte huge *)table;
+            if ((png_size_t)hptr & 0xf)
+            {
+               hptr = (png_byte huge *)((long)(hptr) & 0xfffffff0L);
+               hptr = hptr + 16L;  /* "hptr += 16L" fails on Turbo C++ 3.0 */
+            }
+            for (i = 0; i < num_blocks; i++)
+            {
+               png_ptr->offset_table_ptr[i] = (png_bytep)hptr;
+               hptr = hptr + (png_uint_32)65536L;  /* "+=" fails on TC++3.0 */
+            }
+            png_ptr->offset_table_number = num_blocks;
+            png_ptr->offset_table_count = 0;
+            png_ptr->offset_table_count_free = 0;
+         }
+      }
+      if (png_ptr->offset_table_count >= png_ptr->offset_table_number)
+      {
+#  ifndef PNG_USER_MEM_SUPPORTED
+         if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
+            png_error(png_ptr, "Out of Memory"); /* Note "O" and "M" */
+         else
+            png_warning(png_ptr, "Out of Memory");
+#  endif
+         return (NULL);
+      }
+      ret = png_ptr->offset_table_ptr[png_ptr->offset_table_count++];
+   }
+   else
+      ret = farmalloc(size);
+#  ifndef PNG_USER_MEM_SUPPORTED
+   if (ret == NULL)
+   {
+      if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
+         png_error(png_ptr, "Out of memory"); /* Note "o" and "m" */
+      else
+         png_warning(png_ptr, "Out of memory"); /* Note "o" and "m" */
+   }
+#  endif
+   return (ret);
+}
+/* Free a pointer allocated by png_malloc().  In the default
+ * configuration, png_ptr is not used, but is passed in case it
+ * is needed.  If ptr is NULL, return without taking any action.
+ */
+void PNGAPI
+png_free(png_structp png_ptr, png_voidp ptr)
+{
+   if (png_ptr == NULL || ptr == NULL)
+      return;
+#  ifdef PNG_USER_MEM_SUPPORTED
+   if (png_ptr->free_fn != NULL)
+   {
+      (*(png_ptr->free_fn))(png_ptr, ptr);
+      return;
+   }
+   else
+      png_free_default(png_ptr, ptr);
+}
+void PNGAPI
+png_free_default(png_structp png_ptr, png_voidp ptr)
+{
+#  endif /* PNG_USER_MEM_SUPPORTED */
+   if (png_ptr == NULL || ptr == NULL)
+      return;
+   if (png_ptr->offset_table != NULL)
+   {
+      int i;
+      for (i = 0; i < png_ptr->offset_table_count; i++)
+      {
+         if (ptr == png_ptr->offset_table_ptr[i])
+         {
+            ptr = NULL;
+            png_ptr->offset_table_count_free++;
+            break;
+         }
+      }
+      if (png_ptr->offset_table_count_free == png_ptr->offset_table_count)
+      {
+         farfree(png_ptr->offset_table);
+         farfree(png_ptr->offset_table_ptr);
+         png_ptr->offset_table = NULL;
+         png_ptr->offset_table_ptr = NULL;
+      }
+   }
+   if (ptr != NULL)
+      farfree(ptr);
+}
+#else /* Not the Borland DOS special memory handler */
+/* Allocate memory for a png_struct or a png_info.  The malloc and
+   memset can be replaced by a single call to calloc() if this is thought
+   to improve performance noticably. */
+PNG_FUNCTION(png_voidp /* PRIVATE */,
+png_create_struct,(int type),PNG_ALLOCATED)
+{
+#  ifdef PNG_USER_MEM_SUPPORTED
+   return (png_create_struct_2(type, NULL, NULL));
+}
+/* Allocate memory for a png_struct or a png_info.  The malloc and
+   memset can be replaced by a single call to calloc() if this is thought
+   to improve performance noticably. */
+PNG_FUNCTION(png_voidp /* PRIVATE */,
+png_create_struct_2,(int type, png_malloc_ptr malloc_fn, png_voidp mem_ptr),
+   PNG_ALLOCATED)
+{
+#  endif /* PNG_USER_MEM_SUPPORTED */
+   png_size_t size;
+   png_voidp struct_ptr;
+   if (type == PNG_STRUCT_INFO)
+      size = png_sizeof(png_info);
+   else if (type == PNG_STRUCT_PNG)
+      size = png_sizeof(png_struct);
+   else
+      return (NULL);
+#  ifdef PNG_USER_MEM_SUPPORTED
+   if (malloc_fn != NULL)
+   {
+      png_struct dummy_struct;
+      png_structp png_ptr = &dummy_struct;
+      png_ptr->mem_ptr=mem_ptr;
+      struct_ptr = (*(malloc_fn))(png_ptr, size);
+      if (struct_ptr != NULL)
+         png_memset(struct_ptr, 0, size);
+      return (struct_ptr);
+   }
+#  endif /* PNG_USER_MEM_SUPPORTED */
+#  if defined(__TURBOC__) && !defined(__FLAT__)
+   struct_ptr = (png_voidp)farmalloc(size);
+#  else
+#    if defined(_MSC_VER) && defined(MAXSEG_64K)
+   struct_ptr = (png_voidp)halloc(size, 1);
+#    else
+   struct_ptr = (png_voidp)malloc(size);
+#    endif
+#  endif
+   if (struct_ptr != NULL)
+      png_memset(struct_ptr, 0, size);
+   return (struct_ptr);
+}
+/* Free memory allocated by a png_create_struct() call */
+void /* PRIVATE */
+png_destroy_struct(png_voidp struct_ptr)
+{
+#  ifdef PNG_USER_MEM_SUPPORTED
+   png_destroy_struct_2(struct_ptr, NULL, NULL);
+}
+/* Free memory allocated by a png_create_struct() call */
+void /* PRIVATE */
+png_destroy_struct_2(png_voidp struct_ptr, png_free_ptr free_fn,
+    png_voidp mem_ptr)
+{
+#  endif /* PNG_USER_MEM_SUPPORTED */
+   if (struct_ptr != NULL)
+   {
+#  ifdef PNG_USER_MEM_SUPPORTED
+      if (free_fn != NULL)
+      {
+         png_struct dummy_struct;
+         png_structp png_ptr = &dummy_struct;
+         png_ptr->mem_ptr=mem_ptr;
+         (*(free_fn))(png_ptr, struct_ptr);
+         return;
+      }
+#  endif /* PNG_USER_MEM_SUPPORTED */
+#  if defined(__TURBOC__) && !defined(__FLAT__)
+      farfree(struct_ptr);
+#  else
+#    if defined(_MSC_VER) && defined(MAXSEG_64K)
+      hfree(struct_ptr);
+#    else
+      free(struct_ptr);
+#    endif
+#  endif
+   }
+}
+/* Allocate memory.  For reasonable files, size should never exceed
+ * 64K.  However, zlib may allocate more then 64K if you don't tell
+ * it not to.  See zconf.h and png.h for more information.  zlib does
+ * need to allocate exactly 64K, so whatever you call here must
+ * have the ability to do that.
+ */
+PNG_FUNCTION(png_voidp,PNGAPI
+png_calloc,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
+{
+   png_voidp ret;
+   ret = (png_malloc(png_ptr, size));
+   if (ret != NULL)
+      png_memset(ret,0,(png_size_t)size);
+   return (ret);
+}
+PNG_FUNCTION(png_voidp,PNGAPI
+png_malloc,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
+{
+   png_voidp ret;
+#  ifdef PNG_USER_MEM_SUPPORTED
+   if (png_ptr == NULL || size == 0)
+      return (NULL);
+   if (png_ptr->malloc_fn != NULL)
+      ret = ((png_voidp)(*(png_ptr->malloc_fn))(png_ptr, (png_size_t)size));
+   else
+      ret = (png_malloc_default(png_ptr, size));
+   if (ret == NULL && (png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
+       png_error(png_ptr, "Out of Memory");
+   return (ret);
+}
+PNG_FUNCTION(png_voidp,PNGAPI
+png_malloc_default,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
+{
+   png_voidp ret;
+#  endif /* PNG_USER_MEM_SUPPORTED */
+   if (png_ptr == NULL || size == 0)
+      return (NULL);
+#  ifdef PNG_MAX_MALLOC_64K
+   if (size > (png_uint_32)65536L)
+   {
+#    ifndef PNG_USER_MEM_SUPPORTED
+      if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
+         png_error(png_ptr, "Cannot Allocate > 64K");
+      else
+#    endif
+         return NULL;
+   }
+#  endif
+   /* Check for overflow */
+#  if defined(__TURBOC__) && !defined(__FLAT__)
+   if (size != (unsigned long)size)
+      ret = NULL;
+   else
+      ret = farmalloc(size);
+#  else
+#    if defined(_MSC_VER) && defined(MAXSEG_64K)
+   if (size != (unsigned long)size)
+      ret = NULL;
+   else
+      ret = halloc(size, 1);
+#    else
+   if (size != (size_t)size)
+      ret = NULL;
+   else
+      ret = malloc((size_t)size);
+#    endif
+#  endif
+#  ifndef PNG_USER_MEM_SUPPORTED
+   if (ret == NULL && (png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
+      png_error(png_ptr, "Out of Memory");
+#  endif
+   return (ret);
+}
+/* Free a pointer allocated by png_malloc().  If ptr is NULL, return
+ * without taking any action.
+ */
+void PNGAPI
+png_free(png_structp png_ptr, png_voidp ptr)
+{
+   if (png_ptr == NULL || ptr == NULL)
+      return;
+#  ifdef PNG_USER_MEM_SUPPORTED
+   if (png_ptr->free_fn != NULL)
+   {
+      (*(png_ptr->free_fn))(png_ptr, ptr);
+      return;
+   }
+   else
+      png_free_default(png_ptr, ptr);
+}
+void PNGAPI
+png_free_default(png_structp png_ptr, png_voidp ptr)
+{
+   if (png_ptr == NULL || ptr == NULL)
+      return;
+#  endif /* PNG_USER_MEM_SUPPORTED */
+#  if defined(__TURBOC__) && !defined(__FLAT__)
+   farfree(ptr);
+#  else
+#    if defined(_MSC_VER) && defined(MAXSEG_64K)
+   hfree(ptr);
+#    else
+   free(ptr);
+#    endif
+#  endif
+}
+#endif /* Not Borland DOS special memory handler */
+/* This function was added at libpng version 1.2.3.  The png_malloc_warn()
+ * function will set up png_malloc() to issue a png_warning and return NULL
+ * instead of issuing a png_error, if it fails to allocate the requested
+ * memory.
+ */
+PNG_FUNCTION(png_voidp,PNGAPI
+png_malloc_warn,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
+{
+   png_voidp ptr;
+   png_uint_32 save_flags;
+   if (png_ptr == NULL)
+      return (NULL);
+   save_flags = png_ptr->flags;
+   png_ptr->flags|=PNG_FLAG_MALLOC_NULL_MEM_OK;
+   ptr = (png_voidp)png_malloc((png_structp)png_ptr, size);
+   png_ptr->flags=save_flags;
+   return(ptr);
+}
+#ifdef PNG_USER_MEM_SUPPORTED
+/* This function is called when the application wants to use another method
+ * of allocating and freeing memory.
+ */
+void PNGAPI
+png_set_mem_fn(png_structp png_ptr, png_voidp mem_ptr, png_malloc_ptr
+  malloc_fn, png_free_ptr free_fn)
+{
+   if (png_ptr != NULL)
+   {
+      png_ptr->mem_ptr = mem_ptr;
+      png_ptr->malloc_fn = malloc_fn;
+      png_ptr->free_fn = free_fn;
+   }
+}
+/* This function returns a pointer to the mem_ptr associated with the user
+ * functions.  The application should free any memory associated with this
+ * pointer before png_write_destroy and png_read_destroy are called.
+ */
+png_voidp PNGAPI
+png_get_mem_ptr(png_const_structp png_ptr)
+{
+   if (png_ptr == NULL)
+      return (NULL);
+   return ((png_voidp)png_ptr->mem_ptr);
+}
+#endif /* PNG_USER_MEM_SUPPORTED */
+#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngnow.png b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngnow.png
new file mode 100644
index 0000000..82793eb
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngnow.png
Binary files differ
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngpread.c b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngpread.c
new file mode 100644
index 0000000..eda5a6c
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngpread.c
@@ -0,0 +1,1843 @@
+/* pngpread.c - read a png file in push mode
+ *
+ * Last changed in libpng 1.5.9 [February 18, 2012]
+ * Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+#include "pngpriv.h"
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+/* Push model modes */
+#define PNG_READ_SIG_MODE   0
+#define PNG_READ_CHUNK_MODE 1
+#define PNG_READ_IDAT_MODE  2
+#define PNG_SKIP_MODE       3
+#define PNG_READ_tEXt_MODE  4
+#define PNG_READ_zTXt_MODE  5
+#define PNG_READ_DONE_MODE  6
+#define PNG_READ_iTXt_MODE  7
+#define PNG_ERROR_MODE      8
+void PNGAPI
+png_process_data(png_structp png_ptr, png_infop info_ptr,
+    png_bytep buffer, png_size_t buffer_size)
+{
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+   png_push_restore_buffer(png_ptr, buffer, buffer_size);
+   while (png_ptr->buffer_size)
+   {
+      png_process_some_data(png_ptr, info_ptr);
+   }
+}
+png_size_t PNGAPI
+png_process_data_pause(png_structp png_ptr, int save)
+{
+   if (png_ptr != NULL)
+   {
+      /* It's easiest for the caller if we do the save, then the caller doesn't
+       * have to supply the same data again:
+       */
+      if (save)
+         png_push_save_buffer(png_ptr);
+      else
+      {
+         /* This includes any pending saved bytes: */
+         png_size_t remaining = png_ptr->buffer_size;
+         png_ptr->buffer_size = 0;
+         /* So subtract the saved buffer size, unless all the data
+          * is actually 'saved', in which case we just return 0
+          */
+         if (png_ptr->save_buffer_size < remaining)
+            return remaining - png_ptr->save_buffer_size;
+      }
+   }
+   return 0;
+}
+png_uint_32 PNGAPI
+png_process_data_skip(png_structp png_ptr)
+{
+   png_uint_32 remaining = 0;
+   if (png_ptr != NULL && png_ptr->process_mode == PNG_SKIP_MODE &&
+      png_ptr->skip_length > 0)
+   {
+      /* At the end of png_process_data the buffer size must be 0 (see the loop
+       * above) so we can detect a broken call here:
+       */
+      if (png_ptr->buffer_size != 0)
+         png_error(png_ptr,
+            "png_process_data_skip called inside png_process_data");
+      /* If is impossible for there to be a saved buffer at this point -
+       * otherwise we could not be in SKIP mode.  This will also happen if
+       * png_process_skip is called inside png_process_data (but only very
+       * rarely.)
+       */
+      if (png_ptr->save_buffer_size != 0)
+         png_error(png_ptr, "png_process_data_skip called with saved data");
+      remaining = png_ptr->skip_length;
+      png_ptr->skip_length = 0;
+      png_ptr->process_mode = PNG_READ_CHUNK_MODE;
+   }
+   return remaining;
+}
+/* What we do with the incoming data depends on what we were previously
+ * doing before we ran out of data...
+ */
+void /* PRIVATE */
+png_process_some_data(png_structp png_ptr, png_infop info_ptr)
+{
+   if (png_ptr == NULL)
+      return;
+   switch (png_ptr->process_mode)
+   {
+      case PNG_READ_SIG_MODE:
+      {
+         png_push_read_sig(png_ptr, info_ptr);
+         break;
+      }
+      case PNG_READ_CHUNK_MODE:
+      {
+         png_push_read_chunk(png_ptr, info_ptr);
+         break;
+      }
+      case PNG_READ_IDAT_MODE:
+      {
+         png_push_read_IDAT(png_ptr);
+         break;
+      }
+#ifdef PNG_READ_tEXt_SUPPORTED
+      case PNG_READ_tEXt_MODE:
+      {
+         png_push_read_tEXt(png_ptr, info_ptr);
+         break;
+      }
+#endif
+#ifdef PNG_READ_zTXt_SUPPORTED
+      case PNG_READ_zTXt_MODE:
+      {
+         png_push_read_zTXt(png_ptr, info_ptr);
+         break;
+      }
+#endif
+#ifdef PNG_READ_iTXt_SUPPORTED
+      case PNG_READ_iTXt_MODE:
+      {
+         png_push_read_iTXt(png_ptr, info_ptr);
+         break;
+      }
+#endif
+      case PNG_SKIP_MODE:
+      {
+         png_push_crc_finish(png_ptr);
+         break;
+      }
+      default:
+      {
+         png_ptr->buffer_size = 0;
+         break;
+      }
+   }
+}
+/* Read any remaining signature bytes from the stream and compare them with
+ * the correct PNG signature.  It is possible that this routine is called
+ * with bytes already read from the signature, either because they have been
+ * checked by the calling application, or because of multiple calls to this
+ * routine.
+ */
+void /* PRIVATE */
+png_push_read_sig(png_structp png_ptr, png_infop info_ptr)
+{
+   png_size_t num_checked = png_ptr->sig_bytes,
+             num_to_check = 8 - num_checked;
+   if (png_ptr->buffer_size < num_to_check)
+   {
+      num_to_check = png_ptr->buffer_size;
+   }
+   png_push_fill_buffer(png_ptr, &(info_ptr->signature[num_checked]),
+       num_to_check);
+   png_ptr->sig_bytes = (png_byte)(png_ptr->sig_bytes + num_to_check);
+   if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check))
+   {
+      if (num_checked < 4 &&
+          png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4))
+         png_error(png_ptr, "Not a PNG file");
+      else
+         png_error(png_ptr, "PNG file corrupted by ASCII conversion");
+   }
+   else
+   {
+      if (png_ptr->sig_bytes >= 8)
+      {
+         png_ptr->process_mode = PNG_READ_CHUNK_MODE;
+      }
+   }
+}
+void /* PRIVATE */
+png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
+{
+   png_uint_32 chunk_name;
+   /* First we make sure we have enough data for the 4 byte chunk name
+    * and the 4 byte chunk length before proceeding with decoding the
+    * chunk data.  To fully decode each of these chunks, we also make
+    * sure we have enough data in the buffer for the 4 byte CRC at the
+    * end of every chunk (except IDAT, which is handled separately).
+    */
+   if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
+   {
+      png_byte chunk_length[4];
+      png_byte chunk_tag[4];
+      if (png_ptr->buffer_size < 8)
+      {
+         png_push_save_buffer(png_ptr);
+         return;
+      }
+      png_push_fill_buffer(png_ptr, chunk_length, 4);
+      png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);
+      png_reset_crc(png_ptr);
+      png_crc_read(png_ptr, chunk_tag, 4);
+      png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(chunk_tag);
+      png_check_chunk_name(png_ptr, png_ptr->chunk_name);
+      png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
+   }
+   chunk_name = png_ptr->chunk_name;
+   if (chunk_name == png_IDAT)
+   {
+      /* This is here above the if/else case statement below because if the
+       * unknown handling marks 'IDAT' as unknown then the IDAT handling case is
+       * completely skipped.
+       *
+       * TODO: there must be a better way of doing this.
+       */
+      if (png_ptr->mode & PNG_AFTER_IDAT)
+         png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;
+   }
+   if (chunk_name == png_IHDR)
+   {
+      if (png_ptr->push_length != 13)
+         png_error(png_ptr, "Invalid IHDR length");
+      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      {
+         png_push_save_buffer(png_ptr);
+         return;
+      }
+      png_handle_IHDR(png_ptr, info_ptr, png_ptr->push_length);
+   }
+   else if (chunk_name == png_IEND)
+   {
+      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      {
+         png_push_save_buffer(png_ptr);
+         return;
+      }
+      png_handle_IEND(png_ptr, info_ptr, png_ptr->push_length);
+      png_ptr->process_mode = PNG_READ_DONE_MODE;
+      png_push_have_end(png_ptr, info_ptr);
+   }
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+   else if (png_chunk_unknown_handling(png_ptr, chunk_name))
+   {
+      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      {
+         png_push_save_buffer(png_ptr);
+         return;
+      }
+      if (chunk_name == png_IDAT)
+         png_ptr->mode |= PNG_HAVE_IDAT;
+      png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);
+      if (chunk_name == png_PLTE)
+         png_ptr->mode |= PNG_HAVE_PLTE;
+      else if (chunk_name == png_IDAT)
+      {
+         if (!(png_ptr->mode & PNG_HAVE_IHDR))
+            png_error(png_ptr, "Missing IHDR before IDAT");
+         else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
+             !(png_ptr->mode & PNG_HAVE_PLTE))
+            png_error(png_ptr, "Missing PLTE before IDAT");
+      }
+   }
+#endif
+   else if (chunk_name == png_PLTE)
+   {
+      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      {
+         png_push_save_buffer(png_ptr);
+         return;
+      }
+      png_handle_PLTE(png_ptr, info_ptr, png_ptr->push_length);
+   }
+   else if (chunk_name == png_IDAT)
+   {
+      /* If we reach an IDAT chunk, this means we have read all of the
+       * header chunks, and we can start reading the image (or if this
+       * is called after the image has been read - we have an error).
+       */
+      if (!(png_ptr->mode & PNG_HAVE_IHDR))
+         png_error(png_ptr, "Missing IHDR before IDAT");
+      else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
+          !(png_ptr->mode & PNG_HAVE_PLTE))
+         png_error(png_ptr, "Missing PLTE before IDAT");
+      if (png_ptr->mode & PNG_HAVE_IDAT)
+      {
+         if (!(png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
+            if (png_ptr->push_length == 0)
+               return;
+         if (png_ptr->mode & PNG_AFTER_IDAT)
+            png_benign_error(png_ptr, "Too many IDATs found");
+      }
+      png_ptr->idat_size = png_ptr->push_length;
+      png_ptr->mode |= PNG_HAVE_IDAT;
+      png_ptr->process_mode = PNG_READ_IDAT_MODE;
+      png_push_have_info(png_ptr, info_ptr);
+      png_ptr->zstream.avail_out =
+          (uInt) PNG_ROWBYTES(png_ptr->pixel_depth,
+          png_ptr->iwidth) + 1;
+      png_ptr->zstream.next_out = png_ptr->row_buf;
+      return;
+   }
+#ifdef PNG_READ_gAMA_SUPPORTED
+   else if (png_ptr->chunk_name == png_gAMA)
+   {
+      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      {
+         png_push_save_buffer(png_ptr);
+         return;
+      }
+      png_handle_gAMA(png_ptr, info_ptr, png_ptr->push_length);
+   }
+#endif
+#ifdef PNG_READ_sBIT_SUPPORTED
+   else if (png_ptr->chunk_name == png_sBIT)
+   {
+      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      {
+         png_push_save_buffer(png_ptr);
+         return;
+      }
+      png_handle_sBIT(png_ptr, info_ptr, png_ptr->push_length);
+   }
+#endif
+#ifdef PNG_READ_cHRM_SUPPORTED
+   else if (png_ptr->chunk_name == png_cHRM)
+   {
+      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      {
+         png_push_save_buffer(png_ptr);
+         return;
+      }
+      png_handle_cHRM(png_ptr, info_ptr, png_ptr->push_length);
+   }
+#endif
+#ifdef PNG_READ_sRGB_SUPPORTED
+   else if (chunk_name == png_sRGB)
+   {
+      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      {
+         png_push_save_buffer(png_ptr);
+         return;
+      }
+      png_handle_sRGB(png_ptr, info_ptr, png_ptr->push_length);
+   }
+#endif
+#ifdef PNG_READ_iCCP_SUPPORTED
+   else if (png_ptr->chunk_name == png_iCCP)
+   {
+      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      {
+         png_push_save_buffer(png_ptr);
+         return;
+      }
+      png_handle_iCCP(png_ptr, info_ptr, png_ptr->push_length);
+   }
+#endif
+#ifdef PNG_READ_sPLT_SUPPORTED
+   else if (chunk_name == png_sPLT)
+   {
+      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      {
+         png_push_save_buffer(png_ptr);
+         return;
+      }
+      png_handle_sPLT(png_ptr, info_ptr, png_ptr->push_length);
+   }
+#endif
+#ifdef PNG_READ_tRNS_SUPPORTED
+   else if (chunk_name == png_tRNS)
+   {
+      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      {
+         png_push_save_buffer(png_ptr);
+         return;
+      }
+      png_handle_tRNS(png_ptr, info_ptr, png_ptr->push_length);
+   }
+#endif
+#ifdef PNG_READ_bKGD_SUPPORTED
+   else if (chunk_name == png_bKGD)
+   {
+      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      {
+         png_push_save_buffer(png_ptr);
+         return;
+      }
+      png_handle_bKGD(png_ptr, info_ptr, png_ptr->push_length);
+   }
+#endif
+#ifdef PNG_READ_hIST_SUPPORTED
+   else if (chunk_name == png_hIST)
+   {
+      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      {
+         png_push_save_buffer(png_ptr);
+         return;
+      }
+      png_handle_hIST(png_ptr, info_ptr, png_ptr->push_length);
+   }
+#endif
+#ifdef PNG_READ_pHYs_SUPPORTED
+   else if (chunk_name == png_pHYs)
+   {
+      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      {
+         png_push_save_buffer(png_ptr);
+         return;
+      }
+      png_handle_pHYs(png_ptr, info_ptr, png_ptr->push_length);
+   }
+#endif
+#ifdef PNG_READ_oFFs_SUPPORTED
+   else if (chunk_name == png_oFFs)
+   {
+      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      {
+         png_push_save_buffer(png_ptr);
+         return;
+      }
+      png_handle_oFFs(png_ptr, info_ptr, png_ptr->push_length);
+   }
+#endif
+#ifdef PNG_READ_pCAL_SUPPORTED
+   else if (chunk_name == png_pCAL)
+   {
+      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      {
+         png_push_save_buffer(png_ptr);
+         return;
+      }
+      png_handle_pCAL(png_ptr, info_ptr, png_ptr->push_length);
+   }
+#endif
+#ifdef PNG_READ_sCAL_SUPPORTED
+   else if (chunk_name == png_sCAL)
+   {
+      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      {
+         png_push_save_buffer(png_ptr);
+         return;
+      }
+      png_handle_sCAL(png_ptr, info_ptr, png_ptr->push_length);
+   }
+#endif
+#ifdef PNG_READ_tIME_SUPPORTED
+   else if (chunk_name == png_tIME)
+   {
+      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      {
+         png_push_save_buffer(png_ptr);
+         return;
+      }
+      png_handle_tIME(png_ptr, info_ptr, png_ptr->push_length);
+   }
+#endif
+#ifdef PNG_READ_tEXt_SUPPORTED
+   else if (chunk_name == png_tEXt)
+   {
+      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      {
+         png_push_save_buffer(png_ptr);
+         return;
+      }
+      png_push_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length);
+   }
+#endif
+#ifdef PNG_READ_zTXt_SUPPORTED
+   else if (chunk_name == png_zTXt)
+   {
+      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      {
+         png_push_save_buffer(png_ptr);
+         return;
+      }
+      png_push_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length);
+   }
+#endif
+#ifdef PNG_READ_iTXt_SUPPORTED
+   else if (chunk_name == png_iTXt)
+   {
+      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      {
+         png_push_save_buffer(png_ptr);
+         return;
+      }
+      png_push_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length);
+   }
+#endif
+   else
+   {
+      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      {
+         png_push_save_buffer(png_ptr);
+         return;
+      }
+      png_push_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);
+   }
+   png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
+}
+void /* PRIVATE */
+png_push_crc_skip(png_structp png_ptr, png_uint_32 skip)
+{
+   png_ptr->process_mode = PNG_SKIP_MODE;
+   png_ptr->skip_length = skip;
+}
+void /* PRIVATE */
+png_push_crc_finish(png_structp png_ptr)
+{
+   if (png_ptr->skip_length && png_ptr->save_buffer_size)
+   {
+      png_size_t save_size = png_ptr->save_buffer_size;
+      png_uint_32 skip_length = png_ptr->skip_length;
+      /* We want the smaller of 'skip_length' and 'save_buffer_size', but
+       * they are of different types and we don't know which variable has the
+       * fewest bits.  Carefully select the smaller and cast it to the type of
+       * the larger - this cannot overflow.  Do not cast in the following test
+       * - it will break on either 16 or 64 bit platforms.
+       */
+      if (skip_length < save_size)
+         save_size = (png_size_t)skip_length;
+      else
+         skip_length = (png_uint_32)save_size;
+      png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);
+      png_ptr->skip_length -= skip_length;
+      png_ptr->buffer_size -= save_size;
+      png_ptr->save_buffer_size -= save_size;
+      png_ptr->save_buffer_ptr += save_size;
+   }
+   if (png_ptr->skip_length && png_ptr->current_buffer_size)
+   {
+      png_size_t save_size = png_ptr->current_buffer_size;
+      png_uint_32 skip_length = png_ptr->skip_length;
+      /* We want the smaller of 'skip_length' and 'current_buffer_size', here,
+       * the same problem exists as above and the same solution.
+       */
+      if (skip_length < save_size)
+         save_size = (png_size_t)skip_length;
+      else
+         skip_length = (png_uint_32)save_size;
+      png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);
+      png_ptr->skip_length -= skip_length;
+      png_ptr->buffer_size -= save_size;
+      png_ptr->current_buffer_size -= save_size;
+      png_ptr->current_buffer_ptr += save_size;
+   }
+   if (!png_ptr->skip_length)
+   {
+      if (png_ptr->buffer_size < 4)
+      {
+         png_push_save_buffer(png_ptr);
+         return;
+      }
+      png_crc_finish(png_ptr, 0);
+      png_ptr->process_mode = PNG_READ_CHUNK_MODE;
+   }
+}
+void PNGCBAPI
+png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length)
+{
+   png_bytep ptr;
+   if (png_ptr == NULL)
+      return;
+   ptr = buffer;
+   if (png_ptr->save_buffer_size)
+   {
+      png_size_t save_size;
+      if (length < png_ptr->save_buffer_size)
+         save_size = length;
+      else
+         save_size = png_ptr->save_buffer_size;
+      png_memcpy(ptr, png_ptr->save_buffer_ptr, save_size);
+      length -= save_size;
+      ptr += save_size;
+      png_ptr->buffer_size -= save_size;
+      png_ptr->save_buffer_size -= save_size;
+      png_ptr->save_buffer_ptr += save_size;
+   }
+   if (length && png_ptr->current_buffer_size)
+   {
+      png_size_t save_size;
+      if (length < png_ptr->current_buffer_size)
+         save_size = length;
+      else
+         save_size = png_ptr->current_buffer_size;
+      png_memcpy(ptr, png_ptr->current_buffer_ptr, save_size);
+      png_ptr->buffer_size -= save_size;
+      png_ptr->current_buffer_size -= save_size;
+      png_ptr->current_buffer_ptr += save_size;
+   }
+}
+void /* PRIVATE */
+png_push_save_buffer(png_structp png_ptr)
+{
+   if (png_ptr->save_buffer_size)
+   {
+      if (png_ptr->save_buffer_ptr != png_ptr->save_buffer)
+      {
+         png_size_t i, istop;
+         png_bytep sp;
+         png_bytep dp;
+         istop = png_ptr->save_buffer_size;
+         for (i = 0, sp = png_ptr->save_buffer_ptr, dp = png_ptr->save_buffer;
+             i < istop; i++, sp++, dp++)
+         {
+            *dp = *sp;
+         }
+      }
+   }
+   if (png_ptr->save_buffer_size + png_ptr->current_buffer_size >
+       png_ptr->save_buffer_max)
+   {
+      png_size_t new_max;
+      png_bytep old_buffer;
+      if (png_ptr->save_buffer_size > PNG_SIZE_MAX -
+          (png_ptr->current_buffer_size + 256))
+      {
+         png_error(png_ptr, "Potential overflow of save_buffer");
+      }
+      new_max = png_ptr->save_buffer_size + png_ptr->current_buffer_size + 256;
+      old_buffer = png_ptr->save_buffer;
+      png_ptr->save_buffer = (png_bytep)png_malloc_warn(png_ptr, new_max);
+      if (png_ptr->save_buffer == NULL)
+      {
+         png_free(png_ptr, old_buffer);
+         png_error(png_ptr, "Insufficient memory for save_buffer");
+      }
+      png_memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size);
+      png_free(png_ptr, old_buffer);
+      png_ptr->save_buffer_max = new_max;
+   }
+   if (png_ptr->current_buffer_size)
+   {
+      png_memcpy(png_ptr->save_buffer + png_ptr->save_buffer_size,
+         png_ptr->current_buffer_ptr, png_ptr->current_buffer_size);
+      png_ptr->save_buffer_size += png_ptr->current_buffer_size;
+      png_ptr->current_buffer_size = 0;
+   }
+   png_ptr->save_buffer_ptr = png_ptr->save_buffer;
+   png_ptr->buffer_size = 0;
+}
+void /* PRIVATE */
+png_push_restore_buffer(png_structp png_ptr, png_bytep buffer,
+   png_size_t buffer_length)
+{
+   png_ptr->current_buffer = buffer;
+   png_ptr->current_buffer_size = buffer_length;
+   png_ptr->buffer_size = buffer_length + png_ptr->save_buffer_size;
+   png_ptr->current_buffer_ptr = png_ptr->current_buffer;
+}
+void /* PRIVATE */
+png_push_read_IDAT(png_structp png_ptr)
+{
+   if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
+   {
+      png_byte chunk_length[4];
+      png_byte chunk_tag[4];
+      /* TODO: this code can be commoned up with the same code in push_read */
+      if (png_ptr->buffer_size < 8)
+      {
+         png_push_save_buffer(png_ptr);
+         return;
+      }
+      png_push_fill_buffer(png_ptr, chunk_length, 4);
+      png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);
+      png_reset_crc(png_ptr);
+      png_crc_read(png_ptr, chunk_tag, 4);
+      png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(chunk_tag);
+      png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
+      if (png_ptr->chunk_name != png_IDAT)
+      {
+         png_ptr->process_mode = PNG_READ_CHUNK_MODE;
+         if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
+            png_error(png_ptr, "Not enough compressed data");
+         return;
+      }
+      png_ptr->idat_size = png_ptr->push_length;
+   }
+   if (png_ptr->idat_size && png_ptr->save_buffer_size)
+   {
+      png_size_t save_size = png_ptr->save_buffer_size;
+      png_uint_32 idat_size = png_ptr->idat_size;
+      /* We want the smaller of 'idat_size' and 'current_buffer_size', but they
+       * are of different types and we don't know which variable has the fewest
+       * bits.  Carefully select the smaller and cast it to the type of the
+       * larger - this cannot overflow.  Do not cast in the following test - it
+       * will break on either 16 or 64 bit platforms.
+       */
+      if (idat_size < save_size)
+         save_size = (png_size_t)idat_size;
+      else
+         idat_size = (png_uint_32)save_size;
+      png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);
+      png_process_IDAT_data(png_ptr, png_ptr->save_buffer_ptr, save_size);
+      png_ptr->idat_size -= idat_size;
+      png_ptr->buffer_size -= save_size;
+      png_ptr->save_buffer_size -= save_size;
+      png_ptr->save_buffer_ptr += save_size;
+   }
+   if (png_ptr->idat_size && png_ptr->current_buffer_size)
+   {
+      png_size_t save_size = png_ptr->current_buffer_size;
+      png_uint_32 idat_size = png_ptr->idat_size;
+      /* We want the smaller of 'idat_size' and 'current_buffer_size', but they
+       * are of different types and we don't know which variable has the fewest
+       * bits.  Carefully select the smaller and cast it to the type of the
+       * larger - this cannot overflow.
+       */
+      if (idat_size < save_size)
+         save_size = (png_size_t)idat_size;
+      else
+         idat_size = (png_uint_32)save_size;
+      png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);
+      png_process_IDAT_data(png_ptr, png_ptr->current_buffer_ptr, save_size);
+      png_ptr->idat_size -= idat_size;
+      png_ptr->buffer_size -= save_size;
+      png_ptr->current_buffer_size -= save_size;
+      png_ptr->current_buffer_ptr += save_size;
+   }
+   if (!png_ptr->idat_size)
+   {
+      if (png_ptr->buffer_size < 4)
+      {
+         png_push_save_buffer(png_ptr);
+         return;
+      }
+      png_crc_finish(png_ptr, 0);
+      png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
+      png_ptr->mode |= PNG_AFTER_IDAT;
+   }
+}
+void /* PRIVATE */
+png_process_IDAT_data(png_structp png_ptr, png_bytep buffer,
+   png_size_t buffer_length)
+{
+   /* The caller checks for a non-zero buffer length. */
+   if (!(buffer_length > 0) || buffer == NULL)
+      png_error(png_ptr, "No IDAT data (internal error)");
+   /* This routine must process all the data it has been given
+    * before returning, calling the row callback as required to
+    * handle the uncompressed results.
+    */
+   png_ptr->zstream.next_in = buffer;
+   png_ptr->zstream.avail_in = (uInt)buffer_length;
+   /* Keep going until the decompressed data is all processed
+    * or the stream marked as finished.
+    */
+   while (png_ptr->zstream.avail_in > 0 &&
+          !(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
+   {
+      int ret;
+      /* We have data for zlib, but we must check that zlib
+       * has someplace to put the results.  It doesn't matter
+       * if we don't expect any results -- it may be the input
+       * data is just the LZ end code.
+       */
+      if (!(png_ptr->zstream.avail_out > 0))
+      {
+         png_ptr->zstream.avail_out =
+             (uInt) PNG_ROWBYTES(png_ptr->pixel_depth,
+             png_ptr->iwidth) + 1;
+         png_ptr->zstream.next_out = png_ptr->row_buf;
+      }
+      /* Using Z_SYNC_FLUSH here means that an unterminated
+       * LZ stream (a stream with a missing end code) can still
+       * be handled, otherwise (Z_NO_FLUSH) a future zlib
+       * implementation might defer output and therefore
+       * change the current behavior (see comments in inflate.c
+       * for why this doesn't happen at present with zlib 1.2.5).
+       */
+      ret = inflate(&png_ptr->zstream, Z_SYNC_FLUSH);
+      /* Check for any failure before proceeding. */
+      if (ret != Z_OK && ret != Z_STREAM_END)
+      {
+         /* Terminate the decompression. */
+         png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
+         /* This may be a truncated stream (missing or
+          * damaged end code).  Treat that as a warning.
+          */
+         if (png_ptr->row_number >= png_ptr->num_rows ||
+             png_ptr->pass > 6)
+            png_warning(png_ptr, "Truncated compressed data in IDAT");
+         else
+            png_error(png_ptr, "Decompression error in IDAT");
+         /* Skip the check on unprocessed input */
+         return;
+      }
+      /* Did inflate output any data? */
+      if (png_ptr->zstream.next_out != png_ptr->row_buf)
+      {
+         /* Is this unexpected data after the last row?
+          * If it is, artificially terminate the LZ output
+          * here.
+          */
+         if (png_ptr->row_number >= png_ptr->num_rows ||
+             png_ptr->pass > 6)
+         {
+            /* Extra data. */
+            png_warning(png_ptr, "Extra compressed data in IDAT");
+            png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
+            /* Do no more processing; skip the unprocessed
+             * input check below.
+             */
+            return;
+         }
+         /* Do we have a complete row? */
+         if (png_ptr->zstream.avail_out == 0)
+            png_push_process_row(png_ptr);
+      }
+      /* And check for the end of the stream. */
+      if (ret == Z_STREAM_END)
+         png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
+   }
+   /* All the data should have been processed, if anything
+    * is left at this point we have bytes of IDAT data
+    * after the zlib end code.
+    */
+   if (png_ptr->zstream.avail_in > 0)
+      png_warning(png_ptr, "Extra compression data in IDAT");
+}
+void /* PRIVATE */
+png_push_process_row(png_structp png_ptr)
+{
+   /* 1.5.6: row_info moved out of png_struct to a local here. */
+   png_row_info row_info;
+   row_info.width = png_ptr->iwidth; /* NOTE: width of current interlaced row */
+   row_info.color_type = png_ptr->color_type;
+   row_info.bit_depth = png_ptr->bit_depth;
+   row_info.channels = png_ptr->channels;
+   row_info.pixel_depth = png_ptr->pixel_depth;
+   row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width);
+   if (png_ptr->row_buf[0] > PNG_FILTER_VALUE_NONE)
+   {
+      if (png_ptr->row_buf[0] < PNG_FILTER_VALUE_LAST)
+         png_read_filter_row(png_ptr, &row_info, png_ptr->row_buf + 1,
+            png_ptr->prev_row + 1, png_ptr->row_buf[0]);
+      else
+         png_error(png_ptr, "bad adaptive filter value");
+   }
+   /* libpng 1.5.6: the following line was copying png_ptr->rowbytes before
+    * 1.5.6, while the buffer really is this big in current versions of libpng
+    * it may not be in the future, so this was changed just to copy the
+    * interlaced row count:
+    */
+   png_memcpy(png_ptr->prev_row, png_ptr->row_buf, row_info.rowbytes + 1);
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+   if (png_ptr->transformations)
+      png_do_read_transformations(png_ptr, &row_info);
+#endif
+   /* The transformed pixel depth should match the depth now in row_info. */
+   if (png_ptr->transformed_pixel_depth == 0)
+   {
+      png_ptr->transformed_pixel_depth = row_info.pixel_depth;
+      if (row_info.pixel_depth > png_ptr->maximum_pixel_depth)
+         png_error(png_ptr, "progressive row overflow");
+   }
+   else if (png_ptr->transformed_pixel_depth != row_info.pixel_depth)
+      png_error(png_ptr, "internal progressive row size calculation error");
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+   /* Blow up interlaced rows to full size */
+   if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
+   {
+      if (png_ptr->pass < 6)
+         png_do_read_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass,
+            png_ptr->transformations);
+    switch (png_ptr->pass)
+    {
+         case 0:
+         {
+            int i;
+            for (i = 0; i < 8 && png_ptr->pass == 0; i++)
+            {
+               png_push_have_row(png_ptr, png_ptr->row_buf + 1);
+               png_read_push_finish_row(png_ptr); /* Updates png_ptr->pass */
+            }
+            if (png_ptr->pass == 2) /* Pass 1 might be empty */
+            {
+               for (i = 0; i < 4 && png_ptr->pass == 2; i++)
+               {
+                  png_push_have_row(png_ptr, NULL);
+                  png_read_push_finish_row(png_ptr);
+               }
+            }
+            if (png_ptr->pass == 4 && png_ptr->height <= 4)
+            {
+               for (i = 0; i < 2 && png_ptr->pass == 4; i++)
+               {
+                  png_push_have_row(png_ptr, NULL);
+                  png_read_push_finish_row(png_ptr);
+               }
+            }
+            if (png_ptr->pass == 6 && png_ptr->height <= 4)
+            {
+                png_push_have_row(png_ptr, NULL);
+                png_read_push_finish_row(png_ptr);
+            }
+            break;
+         }
+         case 1:
+         {
+            int i;
+            for (i = 0; i < 8 && png_ptr->pass == 1; i++)
+            {
+               png_push_have_row(png_ptr, png_ptr->row_buf + 1);
+               png_read_push_finish_row(png_ptr);
+            }
+            if (png_ptr->pass == 2) /* Skip top 4 generated rows */
+            {
+               for (i = 0; i < 4 && png_ptr->pass == 2; i++)
+               {
+                  png_push_have_row(png_ptr, NULL);
+                  png_read_push_finish_row(png_ptr);
+               }
+            }
+            break;
+         }
+         case 2:
+         {
+            int i;
+            for (i = 0; i < 4 && png_ptr->pass == 2; i++)
+            {
+               png_push_have_row(png_ptr, png_ptr->row_buf + 1);
+               png_read_push_finish_row(png_ptr);
+            }
+            for (i = 0; i < 4 && png_ptr->pass == 2; i++)
+            {
+               png_push_have_row(png_ptr, NULL);
+               png_read_push_finish_row(png_ptr);
+            }
+            if (png_ptr->pass == 4) /* Pass 3 might be empty */
+            {
+               for (i = 0; i < 2 && png_ptr->pass == 4; i++)
+               {
+                  png_push_have_row(png_ptr, NULL);
+                  png_read_push_finish_row(png_ptr);
+               }
+            }
+            break;
+         }
+         case 3:
+         {
+            int i;
+            for (i = 0; i < 4 && png_ptr->pass == 3; i++)
+            {
+               png_push_have_row(png_ptr, png_ptr->row_buf + 1);
+               png_read_push_finish_row(png_ptr);
+            }
+            if (png_ptr->pass == 4) /* Skip top two generated rows */
+            {
+               for (i = 0; i < 2 && png_ptr->pass == 4; i++)
+               {
+                  png_push_have_row(png_ptr, NULL);
+                  png_read_push_finish_row(png_ptr);
+               }
+            }
+            break;
+         }
+         case 4:
+         {
+            int i;
+            for (i = 0; i < 2 && png_ptr->pass == 4; i++)
+            {
+               png_push_have_row(png_ptr, png_ptr->row_buf + 1);
+               png_read_push_finish_row(png_ptr);
+            }
+            for (i = 0; i < 2 && png_ptr->pass == 4; i++)
+            {
+               png_push_have_row(png_ptr, NULL);
+               png_read_push_finish_row(png_ptr);
+            }
+            if (png_ptr->pass == 6) /* Pass 5 might be empty */
+            {
+               png_push_have_row(png_ptr, NULL);
+               png_read_push_finish_row(png_ptr);
+            }
+            break;
+         }
+         case 5:
+         {
+            int i;
+            for (i = 0; i < 2 && png_ptr->pass == 5; i++)
+            {
+               png_push_have_row(png_ptr, png_ptr->row_buf + 1);
+               png_read_push_finish_row(png_ptr);
+            }
+            if (png_ptr->pass == 6) /* Skip top generated row */
+            {
+               png_push_have_row(png_ptr, NULL);
+               png_read_push_finish_row(png_ptr);
+            }
+            break;
+         }
+         default:
+         case 6:
+         {
+            png_push_have_row(png_ptr, png_ptr->row_buf + 1);
+            png_read_push_finish_row(png_ptr);
+            if (png_ptr->pass != 6)
+               break;
+            png_push_have_row(png_ptr, NULL);
+            png_read_push_finish_row(png_ptr);
+         }
+      }
+   }
+   else
+#endif
+   {
+      png_push_have_row(png_ptr, png_ptr->row_buf + 1);
+      png_read_push_finish_row(png_ptr);
+   }
+}
+void /* PRIVATE */
+png_read_push_finish_row(png_structp png_ptr)
+{
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+   /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+   /* Start of interlace block */
+   static PNG_CONST png_byte FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};
+   /* Offset to next interlace block */
+   static PNG_CONST png_byte FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};
+   /* Start of interlace block in the y direction */
+   static PNG_CONST png_byte FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};
+   /* Offset to next interlace block in the y direction */
+   static PNG_CONST png_byte FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2};
+   /* Height of interlace block.  This is not currently used - if you need
+    * it, uncomment it here and in png.h
+   static PNG_CONST png_byte FARDATA png_pass_height[] = {8, 8, 4, 4, 2, 2, 1};
+   */
+#endif
+   png_ptr->row_number++;
+   if (png_ptr->row_number < png_ptr->num_rows)
+      return;
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+   if (png_ptr->interlaced)
+   {
+      png_ptr->row_number = 0;
+      png_memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
+      do
+      {
+         png_ptr->pass++;
+         if ((png_ptr->pass == 1 && png_ptr->width < 5) ||
+             (png_ptr->pass == 3 && png_ptr->width < 3) ||
+             (png_ptr->pass == 5 && png_ptr->width < 2))
+            png_ptr->pass++;
+         if (png_ptr->pass > 7)
+            png_ptr->pass--;
+         if (png_ptr->pass >= 7)
+            break;
+         png_ptr->iwidth = (png_ptr->width +
+             png_pass_inc[png_ptr->pass] - 1 -
+             png_pass_start[png_ptr->pass]) /
+             png_pass_inc[png_ptr->pass];
+         if (png_ptr->transformations & PNG_INTERLACE)
+            break;
+         png_ptr->num_rows = (png_ptr->height +
+             png_pass_yinc[png_ptr->pass] - 1 -
+             png_pass_ystart[png_ptr->pass]) /
+             png_pass_yinc[png_ptr->pass];
+      } while (png_ptr->iwidth == 0 || png_ptr->num_rows == 0);
+   }
+#endif /* PNG_READ_INTERLACING_SUPPORTED */
+}
+#ifdef PNG_READ_tEXt_SUPPORTED
+void /* PRIVATE */
+png_push_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
+    length)
+{
+   if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
+      {
+         PNG_UNUSED(info_ptr) /* To quiet some compiler warnings */
+         png_error(png_ptr, "Out of place tEXt");
+         /* NOT REACHED */
+      }
+#ifdef PNG_MAX_MALLOC_64K
+   png_ptr->skip_length = 0;  /* This may not be necessary */
+   if (length > (png_uint_32)65535L) /* Can't hold entire string in memory */
+   {
+      png_warning(png_ptr, "tEXt chunk too large to fit in memory");
+      png_ptr->skip_length = length - (png_uint_32)65535L;
+      length = (png_uint_32)65535L;
+   }
+#endif
+   png_ptr->current_text = (png_charp)png_malloc(png_ptr, length + 1);
+   png_ptr->current_text[length] = '\0';
+   png_ptr->current_text_ptr = png_ptr->current_text;
+   png_ptr->current_text_size = (png_size_t)length;
+   png_ptr->current_text_left = (png_size_t)length;
+   png_ptr->process_mode = PNG_READ_tEXt_MODE;
+}
+void /* PRIVATE */
+png_push_read_tEXt(png_structp png_ptr, png_infop info_ptr)
+{
+   if (png_ptr->buffer_size && png_ptr->current_text_left)
+   {
+      png_size_t text_size;
+      if (png_ptr->buffer_size < png_ptr->current_text_left)
+         text_size = png_ptr->buffer_size;
+      else
+         text_size = png_ptr->current_text_left;
+      png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
+      png_ptr->current_text_left -= text_size;
+      png_ptr->current_text_ptr += text_size;
+   }
+   if (!(png_ptr->current_text_left))
+   {
+      png_textp text_ptr;
+      png_charp text;
+      png_charp key;
+      int ret;
+      if (png_ptr->buffer_size < 4)
+      {
+         png_push_save_buffer(png_ptr);
+         return;
+      }
+      png_push_crc_finish(png_ptr);
+#ifdef PNG_MAX_MALLOC_64K
+      if (png_ptr->skip_length)
+         return;
+#endif
+      key = png_ptr->current_text;
+      for (text = key; *text; text++)
+         /* Empty loop */ ;
+      if (text < key + png_ptr->current_text_size)
+         text++;
+      text_ptr = (png_textp)png_malloc(png_ptr, png_sizeof(png_text));
+      text_ptr->compression = PNG_TEXT_COMPRESSION_NONE;
+      text_ptr->key = key;
+      text_ptr->itxt_length = 0;
+      text_ptr->lang = NULL;
+      text_ptr->lang_key = NULL;
+      text_ptr->text = text;
+      ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
+      png_free(png_ptr, key);
+      png_free(png_ptr, text_ptr);
+      png_ptr->current_text = NULL;
+      if (ret)
+         png_warning(png_ptr, "Insufficient memory to store text chunk");
+   }
+}
+#endif
+#ifdef PNG_READ_zTXt_SUPPORTED
+void /* PRIVATE */
+png_push_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
+   length)
+{
+   if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
+   {
+      PNG_UNUSED(info_ptr) /* To quiet some compiler warnings */
+      png_error(png_ptr, "Out of place zTXt");
+      /* NOT REACHED */
+   }
+#ifdef PNG_MAX_MALLOC_64K
+   /* We can't handle zTXt chunks > 64K, since we don't have enough space
+    * to be able to store the uncompressed data.  Actually, the threshold
+    * is probably around 32K, but it isn't as definite as 64K is.
+    */
+   if (length > (png_uint_32)65535L)
+   {
+      png_warning(png_ptr, "zTXt chunk too large to fit in memory");
+      png_push_crc_skip(png_ptr, length);
+      return;
+   }
+#endif
+   png_ptr->current_text = (png_charp)png_malloc(png_ptr, length + 1);
+   png_ptr->current_text[length] = '\0';
+   png_ptr->current_text_ptr = png_ptr->current_text;
+   png_ptr->current_text_size = (png_size_t)length;
+   png_ptr->current_text_left = (png_size_t)length;
+   png_ptr->process_mode = PNG_READ_zTXt_MODE;
+}
+void /* PRIVATE */
+png_push_read_zTXt(png_structp png_ptr, png_infop info_ptr)
+{
+   if (png_ptr->buffer_size && png_ptr->current_text_left)
+   {
+      png_size_t text_size;
+      if (png_ptr->buffer_size < (png_uint_32)png_ptr->current_text_left)
+         text_size = png_ptr->buffer_size;
+      else
+         text_size = png_ptr->current_text_left;
+      png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
+      png_ptr->current_text_left -= text_size;
+      png_ptr->current_text_ptr += text_size;
+   }
+   if (!(png_ptr->current_text_left))
+   {
+      png_textp text_ptr;
+      png_charp text;
+      png_charp key;
+      int ret;
+      png_size_t text_size, key_size;
+      if (png_ptr->buffer_size < 4)
+      {
+         png_push_save_buffer(png_ptr);
+         return;
+      }
+      png_push_crc_finish(png_ptr);
+      key = png_ptr->current_text;
+      for (text = key; *text; text++)
+         /* Empty loop */ ;
+      /* zTXt can't have zero text */
+      if (text >= key + png_ptr->current_text_size)
+      {
+         png_ptr->current_text = NULL;
+         png_free(png_ptr, key);
+         return;
+      }
+      text++;
+      if (*text != PNG_TEXT_COMPRESSION_zTXt) /* Check compression byte */
+      {
+         png_ptr->current_text = NULL;
+         png_free(png_ptr, key);
+         return;
+      }
+      text++;
+      png_ptr->zstream.next_in = (png_bytep)text;
+      png_ptr->zstream.avail_in = (uInt)(png_ptr->current_text_size -
+          (text - key));
+      png_ptr->zstream.next_out = png_ptr->zbuf;
+      png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
+      key_size = text - key;
+      text_size = 0;
+      text = NULL;
+      ret = Z_STREAM_END;
+      while (png_ptr->zstream.avail_in)
+      {
+         ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
+         if (ret != Z_OK && ret != Z_STREAM_END)
+         {
+            inflateReset(&png_ptr->zstream);
+            png_ptr->zstream.avail_in = 0;
+            png_ptr->current_text = NULL;
+            png_free(png_ptr, key);
+            png_free(png_ptr, text);
+            return;
+         }
+         if (!(png_ptr->zstream.avail_out) || ret == Z_STREAM_END)
+         {
+            if (text == NULL)
+            {
+               text = (png_charp)png_malloc(png_ptr,
+                   (png_ptr->zbuf_size
+                   - png_ptr->zstream.avail_out + key_size + 1));
+               png_memcpy(text + key_size, png_ptr->zbuf,
+                   png_ptr->zbuf_size - png_ptr->zstream.avail_out);
+               png_memcpy(text, key, key_size);
+               text_size = key_size + png_ptr->zbuf_size -
+                   png_ptr->zstream.avail_out;
+               *(text + text_size) = '\0';
+            }
+            else
+            {
+               png_charp tmp;
+               tmp = text;
+               text = (png_charp)png_malloc(png_ptr, text_size +
+                   (png_ptr->zbuf_size
+                   - png_ptr->zstream.avail_out + 1));
+               png_memcpy(text, tmp, text_size);
+               png_free(png_ptr, tmp);
+               png_memcpy(text + text_size, png_ptr->zbuf,
+                   png_ptr->zbuf_size - png_ptr->zstream.avail_out);
+               text_size += png_ptr->zbuf_size - png_ptr->zstream.avail_out;
+               *(text + text_size) = '\0';
+            }
+            if (ret != Z_STREAM_END)
+            {
+               png_ptr->zstream.next_out = png_ptr->zbuf;
+               png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
+            }
+         }
+         else
+         {
+            break;
+         }
+         if (ret == Z_STREAM_END)
+            break;
+      }
+      inflateReset(&png_ptr->zstream);
+      png_ptr->zstream.avail_in = 0;
+      if (ret != Z_STREAM_END)
+      {
+         png_ptr->current_text = NULL;
+         png_free(png_ptr, key);
+         png_free(png_ptr, text);
+         return;
+      }
+      png_ptr->current_text = NULL;
+      png_free(png_ptr, key);
+      key = text;
+      text += key_size;
+      text_ptr = (png_textp)png_malloc(png_ptr,
+          png_sizeof(png_text));
+      text_ptr->compression = PNG_TEXT_COMPRESSION_zTXt;
+      text_ptr->key = key;
+      text_ptr->itxt_length = 0;
+      text_ptr->lang = NULL;
+      text_ptr->lang_key = NULL;
+      text_ptr->text = text;
+      ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
+      png_free(png_ptr, key);
+      png_free(png_ptr, text_ptr);
+      if (ret)
+         png_warning(png_ptr, "Insufficient memory to store text chunk");
+   }
+}
+#endif
+#ifdef PNG_READ_iTXt_SUPPORTED
+void /* PRIVATE */
+png_push_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
+    length)
+{
+   if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
+   {
+      PNG_UNUSED(info_ptr) /* To quiet some compiler warnings */
+      png_error(png_ptr, "Out of place iTXt");
+      /* NOT REACHED */
+   }
+#ifdef PNG_MAX_MALLOC_64K
+   png_ptr->skip_length = 0;  /* This may not be necessary */
+   if (length > (png_uint_32)65535L) /* Can't hold entire string in memory */
+   {
+      png_warning(png_ptr, "iTXt chunk too large to fit in memory");
+      png_ptr->skip_length = length - (png_uint_32)65535L;
+      length = (png_uint_32)65535L;
+   }
+#endif
+   png_ptr->current_text = (png_charp)png_malloc(png_ptr, length + 1);
+   png_ptr->current_text[length] = '\0';
+   png_ptr->current_text_ptr = png_ptr->current_text;
+   png_ptr->current_text_size = (png_size_t)length;
+   png_ptr->current_text_left = (png_size_t)length;
+   png_ptr->process_mode = PNG_READ_iTXt_MODE;
+}
+void /* PRIVATE */
+png_push_read_iTXt(png_structp png_ptr, png_infop info_ptr)
+{
+   if (png_ptr->buffer_size && png_ptr->current_text_left)
+   {
+      png_size_t text_size;
+      if (png_ptr->buffer_size < png_ptr->current_text_left)
+         text_size = png_ptr->buffer_size;
+      else
+         text_size = png_ptr->current_text_left;
+      png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
+      png_ptr->current_text_left -= text_size;
+      png_ptr->current_text_ptr += text_size;
+   }
+   if (!(png_ptr->current_text_left))
+   {
+      png_textp text_ptr;
+      png_charp key;
+      int comp_flag;
+      png_charp lang;
+      png_charp lang_key;
+      png_charp text;
+      int ret;
+      if (png_ptr->buffer_size < 4)
+      {
+         png_push_save_buffer(png_ptr);
+         return;
+      }
+      png_push_crc_finish(png_ptr);
+#ifdef PNG_MAX_MALLOC_64K
+      if (png_ptr->skip_length)
+         return;
+#endif
+      key = png_ptr->current_text;
+      for (lang = key; *lang; lang++)
+         /* Empty loop */ ;
+      if (lang < key + png_ptr->current_text_size - 3)
+         lang++;
+      comp_flag = *lang++;
+      lang++;     /* Skip comp_type, always zero */
+      for (lang_key = lang; *lang_key; lang_key++)
+         /* Empty loop */ ;
+      lang_key++;        /* Skip NUL separator */
+      text=lang_key;
+      if (lang_key < key + png_ptr->current_text_size - 1)
+      {
+         for (; *text; text++)
+            /* Empty loop */ ;
+      }
+      if (text < key + png_ptr->current_text_size)
+         text++;
+      text_ptr = (png_textp)png_malloc(png_ptr,
+          png_sizeof(png_text));
+      text_ptr->compression = comp_flag + 2;
+      text_ptr->key = key;
+      text_ptr->lang = lang;
+      text_ptr->lang_key = lang_key;
+      text_ptr->text = text;
+      text_ptr->text_length = 0;
+      text_ptr->itxt_length = png_strlen(text);
+      ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
+      png_ptr->current_text = NULL;
+      png_free(png_ptr, text_ptr);
+      if (ret)
+         png_warning(png_ptr, "Insufficient memory to store iTXt chunk");
+   }
+}
+#endif
+/* This function is called when we haven't found a handler for this
+ * chunk.  If there isn't a problem with the chunk itself (ie a bad chunk
+ * name or a critical chunk), the chunk is (currently) silently ignored.
+ */
+void /* PRIVATE */
+png_push_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32
+    length)
+{
+   png_uint_32 skip = 0;
+   png_uint_32 chunk_name = png_ptr->chunk_name;
+   if (PNG_CHUNK_CRITICAL(chunk_name))
+   {
+#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+      if (png_chunk_unknown_handling(png_ptr, chunk_name) !=
+          PNG_HANDLE_CHUNK_ALWAYS
+#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
+          && png_ptr->read_user_chunk_fn == NULL
+#endif
+          )
+#endif
+         png_chunk_error(png_ptr, "unknown critical chunk");
+      PNG_UNUSED(info_ptr) /* To quiet some compiler warnings */
+   }
+#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+   /* TODO: the code below is apparently just using the
+    * png_struct::unknown_chunk member as a temporarily variable, it should be
+    * possible to eliminate both it and the temporary buffer.
+    */
+   if (png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS)
+   {
+#ifdef PNG_MAX_MALLOC_64K
+      if (length > 65535)
+      {
+         png_warning(png_ptr, "unknown chunk too large to fit in memory");
+         skip = length - 65535;
+         length = 65535;
+      }
+#endif
+      /* This is just a record for the user; libpng doesn't use the character
+       * form of the name.
+       */
+      PNG_CSTRING_FROM_CHUNK(png_ptr->unknown_chunk.name, png_ptr->chunk_name);
+      png_ptr->unknown_chunk.size = length;
+      if (length == 0)
+         png_ptr->unknown_chunk.data = NULL;
+      else
+      {
+         png_ptr->unknown_chunk.data = (png_bytep)png_malloc(png_ptr,
+            png_ptr->unknown_chunk.size);
+         png_crc_read(png_ptr, (png_bytep)png_ptr->unknown_chunk.data,
+            png_ptr->unknown_chunk.size);
+      }
+#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
+      if (png_ptr->read_user_chunk_fn != NULL)
+      {
+         /* Callback to user unknown chunk handler */
+         int ret;
+         ret = (*(png_ptr->read_user_chunk_fn))
+             (png_ptr, &png_ptr->unknown_chunk);
+         if (ret < 0)
+            png_chunk_error(png_ptr, "error in user chunk");
+         if (ret == 0)
+         {
+            if (PNG_CHUNK_CRITICAL(png_ptr->chunk_name))
+               if (png_chunk_unknown_handling(png_ptr, chunk_name) !=
+                   PNG_HANDLE_CHUNK_ALWAYS)
+                  png_chunk_error(png_ptr, "unknown critical chunk");
+            png_set_unknown_chunks(png_ptr, info_ptr,
+                &png_ptr->unknown_chunk, 1);
+         }
+      }
+      else
+#endif
+         png_set_unknown_chunks(png_ptr, info_ptr, &png_ptr->unknown_chunk, 1);
+      png_free(png_ptr, png_ptr->unknown_chunk.data);
+      png_ptr->unknown_chunk.data = NULL;
+   }
+   else
+#endif
+      skip=length;
+   png_push_crc_skip(png_ptr, skip);
+}
+void /* PRIVATE */
+png_push_have_info(png_structp png_ptr, png_infop info_ptr)
+{
+   if (png_ptr->info_fn != NULL)
+      (*(png_ptr->info_fn))(png_ptr, info_ptr);
+}
+void /* PRIVATE */
+png_push_have_end(png_structp png_ptr, png_infop info_ptr)
+{
+   if (png_ptr->end_fn != NULL)
+      (*(png_ptr->end_fn))(png_ptr, info_ptr);
+}
+void /* PRIVATE */
+png_push_have_row(png_structp png_ptr, png_bytep row)
+{
+   if (png_ptr->row_fn != NULL)
+      (*(png_ptr->row_fn))(png_ptr, row, png_ptr->row_number,
+         (int)png_ptr->pass);
+}
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+void PNGAPI
+png_progressive_combine_row (png_structp png_ptr, png_bytep old_row,
+    png_const_bytep new_row)
+{
+   if (png_ptr == NULL)
+      return;
+   /* new_row is a flag here - if it is NULL then the app callback was called
+    * from an empty row (see the calls to png_struct::row_fn below), otherwise
+    * it must be png_ptr->row_buf+1
+    */
+   if (new_row != NULL)
+      png_combine_row(png_ptr, old_row, 1/*display*/);
+}
+#endif /* PNG_READ_INTERLACING_SUPPORTED */
+void PNGAPI
+png_set_progressive_read_fn(png_structp png_ptr, png_voidp progressive_ptr,
+    png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
+    png_progressive_end_ptr end_fn)
+{
+   if (png_ptr == NULL)
+      return;
+   png_ptr->info_fn = info_fn;
+   png_ptr->row_fn = row_fn;
+   png_ptr->end_fn = end_fn;
+   png_set_read_fn(png_ptr, progressive_ptr, png_push_fill_buffer);
+}
+png_voidp PNGAPI
+png_get_progressive_ptr(png_const_structp png_ptr)
+{
+   if (png_ptr == NULL)
+      return (NULL);
+   return png_ptr->io_ptr;
+}
+#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngpriv.h b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngpriv.h
new file mode 100644
index 0000000..5f751de
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngpriv.h
@@ -0,0 +1,1629 @@
+/* pngpriv.h - private declarations for use inside libpng
+ *
+ * For conditions of distribution and use, see copyright notice in png.h
+ * Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * Last changed in libpng 1.5.7 [December 15, 2011]
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+/* The symbols declared in this file (including the functions declared
+ * as PNG_EXTERN) are PRIVATE.  They are not part of the libpng public
+ * interface, and are not recommended for use by regular applications.
+ * Some of them may become public in the future; others may stay private,
+ * change in an incompatible way, or even disappear.
+ * Although the libpng users are not forbidden to include this header,
+ * they should be well aware of the issues that may arise from doing so.
+ */
+#ifndef PNGPRIV_H
+#define PNGPRIV_H
+/* Feature Test Macros.  The following are defined here to ensure that correctly
+ * implemented libraries reveal the APIs libpng needs to build and hide those
+ * that are not needed and potentially damaging to the compilation.
+ *
+ * Feature Test Macros must be defined before any system header is included (see
+ * POSIX 1003.1 2.8.2 "POSIX Symbols."
+ *
+ * These macros only have an effect if the operating system supports either
+ * POSIX 1003.1 or C99, or both.  On other operating systems (particularly
+ * Windows/Visual Studio) there is no effect; the OS specific tests below are
+ * still required (as of 2011-05-02.)
+ */
+#define _POSIX_SOURCE 1 /* Just the POSIX 1003.1 and C89 APIs */
+/* This is required for the definition of abort(), used as a last ditch
+ * error handler when all else fails.
+ */
+#include <stdlib.h>
+/* This is used to find 'offsetof', used below for alignment tests. */
+#include <stddef.h>
+#define PNGLIB_BUILD /*libpng is being built, not used*/
+#ifdef PNG_USER_CONFIG
+#  include "pngusr.h"
+   /* These should have been defined in pngusr.h */
+#  ifndef PNG_USER_PRIVATEBUILD
+#    define PNG_USER_PRIVATEBUILD "Custom libpng build"
+#  endif
+#  ifndef PNG_USER_DLLFNAME_POSTFIX
+#    define PNG_USER_DLLFNAME_POSTFIX "Cb"
+#  endif
+#endif
+/* Is this a build of a DLL where compilation of the object modules requires
+ * different preprocessor settings to those required for a simple library?  If
+ * so PNG_BUILD_DLL must be set.
+ *
+ * If libpng is used inside a DLL but that DLL does not export the libpng APIs
+ * PNG_BUILD_DLL must not be set.  To avoid the code below kicking in build a
+ * static library of libpng then link the DLL against that.
+ */
+#ifndef PNG_BUILD_DLL
+#  ifdef DLL_EXPORT
+      /* This is set by libtool when files are compiled for a DLL; libtool
+       * always compiles twice, even on systems where it isn't necessary.  Set
+       * PNG_BUILD_DLL in case it is necessary:
+       */
+#     define PNG_BUILD_DLL
+#  else
+#     ifdef _WINDLL
+         /* This is set by the Microsoft Visual Studio IDE in projects that
+          * build a DLL.  It can't easily be removed from those projects (it
+          * isn't visible in the Visual Studio UI) so it is a fairly reliable
+          * indication that PNG_IMPEXP needs to be set to the DLL export
+          * attributes.
+          */
+#        define PNG_BUILD_DLL
+#     else
+#        ifdef __DLL__
+            /* This is set by the Borland C system when compiling for a DLL
+             * (as above.)
+             */
+#           define PNG_BUILD_DLL
+#        else
+            /* Add additional compiler cases here. */
+#        endif
+#     endif
+#  endif
+#endif /* Setting PNG_BUILD_DLL if required */
+/* See pngconf.h for more details: the builder of the library may set this on
+ * the command line to the right thing for the specific compilation system or it
+ * may be automagically set above (at present we know of no system where it does
+ * need to be set on the command line.)
+ *
+ * PNG_IMPEXP must be set here when building the library to prevent pngconf.h
+ * setting it to the "import" setting for a DLL build.
+ */
+#ifndef PNG_IMPEXP
+#  ifdef PNG_BUILD_DLL
+#     define PNG_IMPEXP PNG_DLL_EXPORT
+#  else
+      /* Not building a DLL, or the DLL doesn't require specific export
+       * definitions.
+       */
+#     define PNG_IMPEXP
+#  endif
+#endif
+/* No warnings for private or deprecated functions in the build: */
+#ifndef PNG_DEPRECATED
+#  define PNG_DEPRECATED
+#endif
+#ifndef PNG_PRIVATE
+#  define PNG_PRIVATE
+#endif
+#include "png.h"
+#include "pnginfo.h"
+#include "pngstruct.h"
+/* pngconf.h does not set PNG_DLL_EXPORT unless it is required, so: */
+#ifndef PNG_DLL_EXPORT
+#  define PNG_DLL_EXPORT
+#endif
+/* This is used for 16 bit gamma tables - only the top level pointers are const,
+ * this could be changed:
+ */
+typedef PNG_CONST png_uint_16p FAR * png_const_uint_16pp;
+/* Added at libpng-1.2.9 */
+/* Moved to pngpriv.h at libpng-1.5.0 */
+/* config.h is created by and PNG_CONFIGURE_LIBPNG is set by the "configure"
+ * script.  We may need it here to get the correct configuration on things
+ * like limits.
+ */
+#ifdef PNG_CONFIGURE_LIBPNG
+#  ifdef HAVE_CONFIG_H
+#    include "config.h"
+#  endif
+#endif
+/* Moved to pngpriv.h at libpng-1.5.0 */
+/* NOTE: some of these may have been used in external applications as
+ * these definitions were exposed in pngconf.h prior to 1.5.
+ */
+/* If you are running on a machine where you cannot allocate more
+ * than 64K of memory at once, uncomment this.  While libpng will not
+ * normally need that much memory in a chunk (unless you load up a very
+ * large file), zlib needs to know how big of a chunk it can use, and
+ * libpng thus makes sure to check any memory allocation to verify it
+ * will fit into memory.
+ *
+ * zlib provides 'MAXSEG_64K' which, if defined, indicates the
+ * same limit and pngconf.h (already included) sets the limit
+ * if certain operating systems are detected.
+ */
+#if defined(MAXSEG_64K) && !defined(PNG_MAX_MALLOC_64K)
+#  define PNG_MAX_MALLOC_64K
+#endif
+#ifndef PNG_UNUSED
+/* Unused formal parameter warnings are silenced using the following macro
+ * which is expected to have no bad effects on performance (optimizing
+ * compilers will probably remove it entirely).  Note that if you replace
+ * it with something other than whitespace, you must include the terminating
+ * semicolon.
+ */
+#  define PNG_UNUSED(param) (void)param;
+#endif
+/* Just a little check that someone hasn't tried to define something
+ * contradictory.
+ */
+#if (PNG_ZBUF_SIZE > 65536L) && defined(PNG_MAX_MALLOC_64K)
+#  undef PNG_ZBUF_SIZE
+#  define PNG_ZBUF_SIZE 65536L
+#endif
+/* PNG_STATIC is used to mark internal file scope functions if they need to be
+ * accessed for implementation tests (see the code in tests/?*).
+ */
+#ifndef PNG_STATIC
+#   define PNG_STATIC static
+#endif
+/* C99 restrict is used where possible, to do this 'restrict' is defined as
+ * empty if we can't be sure it is supported.  configure builds have already
+ * done this work.
+ */
+#ifdef PNG_CONFIGURE_LIBPNG
+#  define PNG_RESTRICT restrict
+#else
+   /* Modern compilers support restrict, but assume not for anything not
+    * recognized here:
+    */
+#  if defined __GNUC__ || defined _MSC_VER || defined __WATCOMC__
+#     define PNG_RESTRICT restrict
+#  else
+#     define PNG_RESTRICT
+#  endif
+#endif
+/* If warnings or errors are turned off the code is disabled or redirected here.
+ * From 1.5.4 functions have been added to allow very limited formatting of
+ * error and warning messages - this code will also be disabled here.
+ */
+#ifdef PNG_WARNINGS_SUPPORTED
+#  define PNG_WARNING_PARAMETERS(p) png_warning_parameters p;
+#else
+#  define png_warning(s1,s2) ((void)(s1))
+#  define png_chunk_warning(s1,s2) ((void)(s1))
+#  define png_warning_parameter(p,number,string) ((void)0)
+#  define png_warning_parameter_unsigned(p,number,format,value) ((void)0)
+#  define png_warning_parameter_signed(p,number,format,value) ((void)0)
+#  define png_formatted_warning(pp,p,message) ((void)(pp))
+#  define PNG_WARNING_PARAMETERS(p)
+#endif
+#ifndef PNG_ERROR_TEXT_SUPPORTED
+#  define png_error(s1,s2) png_err(s1)
+#  define png_chunk_error(s1,s2) png_err(s1)
+#  define png_fixed_error(s1,s2) png_err(s1)
+#endif
+/* C allows up-casts from (void*) to any pointer and (const void*) to any
+ * pointer to a const object.  C++ regards this as a type error and requires an
+ * explicit, static, cast and provides the static_cast<> rune to ensure that
+ * const is not cast away.
+ */
+#ifdef __cplusplus
+#  define png_voidcast(type, value) static_cast<type>(value)
+#else
+#  define png_voidcast(type, value) (value)
+#endif /* __cplusplus */
+#ifndef PNG_EXTERN
+/* The functions exported by PNG_EXTERN are internal functions, which
+ * aren't usually used outside the library (as far as I know), so it is
+ * debatable if they should be exported at all.  In the future, when it
+ * is possible to have run-time registry of chunk-handling functions,
+ * some of these might be made available again.
+ *
+ * 1.5.7: turned the use of 'extern' back on, since it is localized to pngpriv.h
+ * it should be safe now (it is unclear why it was turned off.)
+ */
+#  define PNG_EXTERN extern
+#endif
+/* Some fixed point APIs are still required even if not exported because
+ * they get used by the corresponding floating point APIs.  This magic
+ * deals with this:
+ */
+#ifdef PNG_FIXED_POINT_SUPPORTED
+#  define PNGFAPI PNGAPI
+#else
+#  define PNGFAPI /* PRIVATE */
+#endif
+/* Other defines specific to compilers can go here.  Try to keep
+ * them inside an appropriate ifdef/endif pair for portability.
+ */
+#if defined(PNG_FLOATING_POINT_SUPPORTED) ||\
+    defined(PNG_FLOATING_ARITHMETIC_SUPPORTED)
+   /* png.c requires the following ANSI-C constants if the conversion of
+    * floating point to ASCII is implemented therein:
+    *
+    *  DBL_DIG  Maximum number of decimal digits (can be set to any constant)
+    *  DBL_MIN  Smallest normalized fp number (can be set to an arbitrary value)
+    *  DBL_MAX  Maximum floating point number (can be set to an arbitrary value)
+    */
+#  include <float.h>
+#  if (defined(__MWERKS__) && defined(macintosh)) || defined(applec) || \
+    defined(THINK_C) || defined(__SC__) || defined(TARGET_OS_MAC)
+     /* We need to check that <math.h> hasn't already been included earlier
+      * as it seems it doesn't agree with <fp.h>, yet we should really use
+      * <fp.h> if possible.
+      */
+#    if !defined(__MATH_H__) && !defined(__MATH_H) && !defined(__cmath__)
+#      include <fp.h>
+#    endif
+#  else
+#    include <math.h>
+#  endif
+#  if defined(_AMIGA) && defined(__SASC) && defined(_M68881)
+     /* Amiga SAS/C: We must include builtin FPU functions when compiling using
+      * MATH=68881
+      */
+#    include <m68881.h>
+#  endif
+#endif
+/* This provides the non-ANSI (far) memory allocation routines. */
+#if defined(__TURBOC__) && defined(__MSDOS__)
+#  include <mem.h>
+#  include <alloc.h>
+#endif
+#if defined(WIN32) || defined(_Windows) || defined(_WINDOWS) || \
+    defined(_WIN32) || defined(__WIN32__)
+#  include <windows.h>  /* defines _WINDOWS_ macro */
+#endif
+/* Moved here around 1.5.0beta36 from pngconf.h */
+/* Users may want to use these so they are not private.  Any library
+ * functions that are passed far data must be model-independent.
+ */
+/* Memory model/platform independent fns */
+#ifndef PNG_ABORT
+#  ifdef _WINDOWS_
+#    define PNG_ABORT() ExitProcess(0)
+#  else
+#    define PNG_ABORT() abort()
+#  endif
+#endif
+#ifdef USE_FAR_KEYWORD
+/* Use this to make far-to-near assignments */
+#  define CHECK   1
+#  define NOCHECK 0
+#  define CVT_PTR(ptr) (png_far_to_near(png_ptr,ptr,CHECK))
+#  define CVT_PTR_NOCHECK(ptr) (png_far_to_near(png_ptr,ptr,NOCHECK))
+#  define png_strlen  _fstrlen
+#  define png_memcmp  _fmemcmp    /* SJT: added */
+#  define png_memcpy  _fmemcpy
+#  define png_memset  _fmemset
+#else
+#  ifdef _WINDOWS_  /* Favor Windows over C runtime fns */
+#    define CVT_PTR(ptr)         (ptr)
+#    define CVT_PTR_NOCHECK(ptr) (ptr)
+#    define png_strlen  lstrlenA
+#    define png_memcmp  memcmp
+#    define png_memcpy  CopyMemory
+#    define png_memset  memset
+#  else
+#    define CVT_PTR(ptr)         (ptr)
+#    define CVT_PTR_NOCHECK(ptr) (ptr)
+#    define png_strlen  strlen
+#    define png_memcmp  memcmp      /* SJT: added */
+#    define png_memcpy  memcpy
+#    define png_memset  memset
+#  endif
+#endif
+/* These macros may need to be architecture dependent. */
+#define PNG_ALIGN_NONE   0 /* do not use data alignment */
+#define PNG_ALIGN_ALWAYS 1 /* assume unaligned accesses are OK */
+#ifdef offsetof
+#  define PNG_ALIGN_OFFSET 2 /* use offsetof to determine alignment */
+#else
+#  define PNG_ALIGN_OFFSET -1 /* prevent the use of this */
+#endif
+#define PNG_ALIGN_SIZE   3 /* use sizeof to determine alignment */
+#ifndef PNG_ALIGN_TYPE
+   /* Default to using aligned access optimizations and requiring alignment to a
+    * multiple of the data type size.  Override in a compiler specific fashion
+    * if necessary by inserting tests here:
+    */
+#  define PNG_ALIGN_TYPE PNG_ALIGN_SIZE
+#endif
+#if PNG_ALIGN_TYPE == PNG_ALIGN_SIZE
+   /* This is used because in some compiler implementations non-aligned
+    * structure members are supported, so the offsetof approach below fails.
+    * Set PNG_ALIGN_TO_SIZE=0 for compiler combinations where unaligned access
+    * is good for performance.  Do not do this unless you have tested the result
+    * and understand it.
+    */
+#  define png_alignof(type) (sizeof (type))
+#else
+#  if PNG_ALIGN_TYPE == PNG_ALIGN_OFFSET
+#     define png_alignof(type) offsetof(struct{char c; type t;}, t)
+#  else
+#     if PNG_ALIGN_TYPE == PNG_ALIGN_ALWAYS
+#        define png_alignof(type) (1)
+#     endif
+      /* Else leave png_alignof undefined to prevent use thereof */
+#  endif
+#endif
+/* This implicitly assumes alignment is always to a power of 2. */
+#ifdef png_alignof
+#  define png_isaligned(ptr, type)\
+   ((((const char*)ptr-(const char*)0) & (png_alignof(type)-1)) == 0)
+#else
+#  define png_isaligned(ptr, type) 0
+#endif
+/* End of memory model/platform independent support */
+/* End of 1.5.0beta36 move from pngconf.h */
+/* CONSTANTS and UTILITY MACROS
+ * These are used internally by libpng and not exposed in the API
+ */
+/* Various modes of operation.  Note that after an init, mode is set to
+ * zero automatically when the structure is created.  Three of these
+ * are defined in png.h because they need to be visible to applications
+ * that call png_set_unknown_chunk().
+ */
+/* #define PNG_HAVE_IHDR            0x01 (defined in png.h) */
+/* #define PNG_HAVE_PLTE            0x02 (defined in png.h) */
+#define PNG_HAVE_IDAT               0x04
+/* #define PNG_AFTER_IDAT           0x08 (defined in png.h) */
+#define PNG_HAVE_IEND               0x10
+#define PNG_HAVE_gAMA               0x20
+#define PNG_HAVE_cHRM               0x40
+#define PNG_HAVE_sRGB               0x80
+#define PNG_HAVE_CHUNK_HEADER      0x100
+#define PNG_WROTE_tIME             0x200
+#define PNG_WROTE_INFO_BEFORE_PLTE 0x400
+#define PNG_BACKGROUND_IS_GRAY     0x800
+#define PNG_HAVE_PNG_SIGNATURE    0x1000
+#define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000 /* Have another chunk after IDAT */
+/* Flags for the transformations the PNG library does on the image data */
+#define PNG_BGR                 0x0001
+#define PNG_INTERLACE           0x0002
+#define PNG_PACK                0x0004
+#define PNG_SHIFT               0x0008
+#define PNG_SWAP_BYTES          0x0010
+#define PNG_INVERT_MONO         0x0020
+#define PNG_QUANTIZE            0x0040
+#define PNG_COMPOSE             0x0080     /* Was PNG_BACKGROUND */
+#define PNG_BACKGROUND_EXPAND   0x0100
+#define PNG_EXPAND_16           0x0200     /* Added to libpng 1.5.2 */
+#define PNG_16_TO_8             0x0400     /* Becomes 'chop' in 1.5.4 */
+#define PNG_RGBA                0x0800
+#define PNG_EXPAND              0x1000
+#define PNG_GAMMA               0x2000
+#define PNG_GRAY_TO_RGB         0x4000
+#define PNG_FILLER              0x8000
+#define PNG_PACKSWAP           0x10000
+#define PNG_SWAP_ALPHA         0x20000
+#define PNG_STRIP_ALPHA        0x40000
+#define PNG_INVERT_ALPHA       0x80000
+#define PNG_USER_TRANSFORM    0x100000
+#define PNG_RGB_TO_GRAY_ERR   0x200000
+#define PNG_RGB_TO_GRAY_WARN  0x400000
+#define PNG_RGB_TO_GRAY       0x600000 /* two bits, RGB_TO_GRAY_ERR|WARN */
+#define PNG_ENCODE_ALPHA      0x800000 /* Added to libpng-1.5.4 */
+#define PNG_ADD_ALPHA         0x1000000 /* Added to libpng-1.2.7 */
+#define PNG_EXPAND_tRNS       0x2000000 /* Added to libpng-1.2.9 */
+#define PNG_SCALE_16_TO_8     0x4000000 /* Added to libpng-1.5.4 */
+                       /*   0x8000000 unused */
+                       /*  0x10000000 unused */
+                       /*  0x20000000 unused */
+                       /*  0x40000000 unused */
+/* Flags for png_create_struct */
+#define PNG_STRUCT_PNG   0x0001
+#define PNG_STRUCT_INFO  0x0002
+/* Scaling factor for filter heuristic weighting calculations */
+#define PNG_WEIGHT_FACTOR (1<<(PNG_WEIGHT_SHIFT))
+#define PNG_COST_FACTOR (1<<(PNG_COST_SHIFT))
+/* Flags for the png_ptr->flags rather than declaring a byte for each one */
+#define PNG_FLAG_ZLIB_CUSTOM_STRATEGY     0x0001
+#define PNG_FLAG_ZLIB_CUSTOM_LEVEL        0x0002
+#define PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL    0x0004
+#define PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS  0x0008
+#define PNG_FLAG_ZLIB_CUSTOM_METHOD       0x0010
+#define PNG_FLAG_ZLIB_FINISHED            0x0020
+#define PNG_FLAG_ROW_INIT                 0x0040
+#define PNG_FLAG_FILLER_AFTER             0x0080
+#define PNG_FLAG_CRC_ANCILLARY_USE        0x0100
+#define PNG_FLAG_CRC_ANCILLARY_NOWARN     0x0200
+#define PNG_FLAG_CRC_CRITICAL_USE         0x0400
+#define PNG_FLAG_CRC_CRITICAL_IGNORE      0x0800
+#define PNG_FLAG_ASSUME_sRGB              0x1000  /* Added to libpng-1.5.4 */
+#define PNG_FLAG_OPTIMIZE_ALPHA           0x2000  /* Added to libpng-1.5.4 */
+#define PNG_FLAG_DETECT_UNINITIALIZED     0x4000  /* Added to libpng-1.5.4 */
+#define PNG_FLAG_KEEP_UNKNOWN_CHUNKS      0x8000
+#define PNG_FLAG_KEEP_UNSAFE_CHUNKS       0x10000
+#define PNG_FLAG_LIBRARY_MISMATCH         0x20000
+#define PNG_FLAG_STRIP_ERROR_NUMBERS      0x40000
+#define PNG_FLAG_STRIP_ERROR_TEXT         0x80000
+#define PNG_FLAG_MALLOC_NULL_MEM_OK       0x100000
+                                  /*      0x200000  unused */
+                                  /*      0x400000  unused */
+#define PNG_FLAG_BENIGN_ERRORS_WARN       0x800000  /* Added to libpng-1.4.0 */
+#define PNG_FLAG_ZTXT_CUSTOM_STRATEGY    0x1000000  /* 5 lines added */
+#define PNG_FLAG_ZTXT_CUSTOM_LEVEL       0x2000000  /* to libpng-1.5.4 */
+#define PNG_FLAG_ZTXT_CUSTOM_MEM_LEVEL   0x4000000
+#define PNG_FLAG_ZTXT_CUSTOM_WINDOW_BITS 0x8000000
+#define PNG_FLAG_ZTXT_CUSTOM_METHOD      0x10000000
+                                  /*     0x20000000  unused */
+                                  /*     0x40000000  unused */
+#define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \
+                                     PNG_FLAG_CRC_ANCILLARY_NOWARN)
+#define PNG_FLAG_CRC_CRITICAL_MASK  (PNG_FLAG_CRC_CRITICAL_USE | \
+                                     PNG_FLAG_CRC_CRITICAL_IGNORE)
+#define PNG_FLAG_CRC_MASK           (PNG_FLAG_CRC_ANCILLARY_MASK | \
+                                     PNG_FLAG_CRC_CRITICAL_MASK)
+/* zlib.h declares a magic type 'uInt' that limits the amount of data that zlib
+ * can handle at once.  This type need be no larger than 16 bits (so maximum of
+ * 65535), this define allows us to discover how big it is, but limited by the
+ * maximuum for png_size_t.  The value can be overriden in a library build
+ * (pngusr.h, or set it in CPPFLAGS) and it works to set it to a considerably
+ * lower value (e.g. 255 works).  A lower value may help memory usage (slightly)
+ * and may even improve performance on some systems (and degrade it on others.)
+ */
+#ifndef ZLIB_IO_MAX
+#  define ZLIB_IO_MAX ((uInt)-1)
+#endif
+/* Save typing and make code easier to understand */
+#define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \
+   abs((int)((c1).green) - (int)((c2).green)) + \
+   abs((int)((c1).blue) - (int)((c2).blue)))
+/* Added to libpng-1.2.6 JB */
+#define PNG_ROWBYTES(pixel_bits, width) \
+    ((pixel_bits) >= 8 ? \
+    ((png_size_t)(width) * (((png_size_t)(pixel_bits)) >> 3)) : \
+    (( ((png_size_t)(width) * ((png_size_t)(pixel_bits))) + 7) >> 3) )
+/* PNG_OUT_OF_RANGE returns true if value is outside the range
+ * ideal-delta..ideal+delta.  Each argument is evaluated twice.
+ * "ideal" and "delta" should be constants, normally simple
+ * integers, "value" a variable. Added to libpng-1.2.6 JB
+ */
+#define PNG_OUT_OF_RANGE(value, ideal, delta) \
+   ( (value) < (ideal)-(delta) || (value) > (ideal)+(delta) )
+/* Conversions between fixed and floating point, only defined if
+ * required (to make sure the code doesn't accidentally use float
+ * when it is supposedly disabled.)
+ */
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+/* The floating point conversion can't overflow, though it can and
+ * does lose accuracy relative to the original fixed point value.
+ * In practice this doesn't matter because png_fixed_point only
+ * stores numbers with very low precision.  The png_ptr and s
+ * arguments are unused by default but are there in case error
+ * checking becomes a requirement.
+ */
+#define png_float(png_ptr, fixed, s) (.00001 * (fixed))
+/* The fixed point conversion performs range checking and evaluates
+ * its argument multiple times, so must be used with care.  The
+ * range checking uses the PNG specification values for a signed
+ * 32 bit fixed point value except that the values are deliberately
+ * rounded-to-zero to an integral value - 21474 (21474.83 is roughly
+ * (2^31-1) * 100000). 's' is a string that describes the value being
+ * converted.
+ *
+ * NOTE: this macro will raise a png_error if the range check fails,
+ * therefore it is normally only appropriate to use this on values
+ * that come from API calls or other sources where an out of range
+ * error indicates a programming error, not a data error!
+ *
+ * NOTE: by default this is off - the macro is not used - because the
+ * function call saves a lot of code.
+ */
+#ifdef PNG_FIXED_POINT_MACRO_SUPPORTED
+#define png_fixed(png_ptr, fp, s) ((fp) <= 21474 && (fp) >= -21474 ?\
+    ((png_fixed_point)(100000 * (fp))) : (png_fixed_error(png_ptr, s),0))
+#else
+PNG_EXTERN png_fixed_point png_fixed PNGARG((png_structp png_ptr, double fp,
+   png_const_charp text));
+#endif
+#endif
+/* Constants for known chunk types.  If you need to add a chunk, define the name
+ * here.  For historical reasons these constants have the form png_<name>; i.e.
+ * the prefix is lower case.  Please use decimal values as the parameters to
+ * match the ISO PNG specification and to avoid relying on the C locale
+ * interpretation of character values.
+ *
+ * Prior to 1.5.6 these constants were strings, as of 1.5.6 png_uint_32 values
+ * are computed and a new macro (PNG_STRING_FROM_CHUNK) added to allow a string
+ * to be generated if required.
+ *
+ * PNG_32b correctly produces a value shifted by up to 24 bits, even on
+ * architectures where (int) is only 16 bits.
+ */
+#define PNG_32b(b,s) ((png_uint_32)(b) << (s))
+#define PNG_CHUNK(b1,b2,b3,b4) \
+   (PNG_32b(b1,24) | PNG_32b(b2,16) | PNG_32b(b3,8) | PNG_32b(b4,0))
+#define png_IHDR PNG_CHUNK( 73,  72,  68,  82)
+#define png_IDAT PNG_CHUNK( 73,  68,  65,  84)
+#define png_IEND PNG_CHUNK( 73,  69,  78,  68)
+#define png_PLTE PNG_CHUNK( 80,  76,  84,  69)
+#define png_bKGD PNG_CHUNK( 98,  75,  71,  68)
+#define png_cHRM PNG_CHUNK( 99,  72,  82,  77)
+#define png_gAMA PNG_CHUNK(103,  65,  77,  65)
+#define png_hIST PNG_CHUNK(104,  73,  83,  84)
+#define png_iCCP PNG_CHUNK(105,  67,  67,  80)
+#define png_iTXt PNG_CHUNK(105,  84,  88, 116)
+#define png_oFFs PNG_CHUNK(111,  70,  70, 115)
+#define png_pCAL PNG_CHUNK(112,  67,  65,  76)
+#define png_sCAL PNG_CHUNK(115,  67,  65,  76)
+#define png_pHYs PNG_CHUNK(112,  72,  89, 115)
+#define png_sBIT PNG_CHUNK(115,  66,  73,  84)
+#define png_sPLT PNG_CHUNK(115,  80,  76,  84)
+#define png_sRGB PNG_CHUNK(115,  82,  71,  66)
+#define png_sTER PNG_CHUNK(115,  84,  69,  82)
+#define png_tEXt PNG_CHUNK(116,  69,  88, 116)
+#define png_tIME PNG_CHUNK(116,  73,  77,  69)
+#define png_tRNS PNG_CHUNK(116,  82,  78,  83)
+#define png_zTXt PNG_CHUNK(122,  84,  88, 116)
+/* The following will work on (signed char*) strings, whereas the get_uint_32
+ * macro will fail on top-bit-set values because of the sign extension.
+ */
+#define PNG_CHUNK_FROM_STRING(s)\
+   PNG_CHUNK(0xff&(s)[0], 0xff&(s)[1], 0xff&(s)[2], 0xff&(s)[3])
+/* This uses (char), not (png_byte) to avoid warnings on systems where (char) is
+ * signed and the argument is a (char[])  This macro will fail miserably on
+ * systems where (char) is more than 8 bits.
+ */
+#define PNG_STRING_FROM_CHUNK(s,c)\
+   (void)(((char*)(s))[0]=(char)((c)>>24), ((char*)(s))[1]=(char)((c)>>16),\
+   ((char*)(s))[2]=(char)((c)>>8), ((char*)(s))[3]=(char)((c)))
+/* Do the same but terminate with a null character. */
+#define PNG_CSTRING_FROM_CHUNK(s,c)\
+   (void)(PNG_STRING_FROM_CHUNK(s,c), ((char*)(s))[4] = 0)
+/* Test on flag values as defined in the spec (section 5.4): */
+#define PNG_CHUNK_ANCILLIARY(c)   (1 & ((c) >> 29))
+#define PNG_CHUNK_CRITICAL(c)     (!PNG_CHUNK_ANCILLIARY(c))
+#define PNG_CHUNK_PRIVATE(c)      (1 & ((c) >> 21))
+#define PNG_CHUNK_RESERVED(c)     (1 & ((c) >> 13))
+#define PNG_CHUNK_SAFE_TO_COPY(c) (1 & ((c) >>  5))
+/* Gamma values (new at libpng-1.5.4): */
+#define PNG_GAMMA_MAC_OLD 151724  /* Assume '1.8' is really 2.2/1.45! */
+#define PNG_GAMMA_MAC_INVERSE 65909
+#define PNG_GAMMA_sRGB_INVERSE 45455
+/* Inhibit C++ name-mangling for libpng functions but not for system calls. */
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+/* These functions are used internally in the code.  They generally
+ * shouldn't be used unless you are writing code to add or replace some
+ * functionality in libpng.  More information about most functions can
+ * be found in the files where the functions are located.
+ */
+/* Check the user version string for compatibility, returns false if the version
+ * numbers aren't compatible.
+ */
+PNG_EXTERN int png_user_version_check(png_structp png_ptr,
+   png_const_charp user_png_ver);
+/* Allocate memory for an internal libpng struct */
+PNG_EXTERN PNG_FUNCTION(png_voidp,png_create_struct,PNGARG((int type)),
+   PNG_ALLOCATED);
+/* Free memory from internal libpng struct */
+PNG_EXTERN void png_destroy_struct PNGARG((png_voidp struct_ptr));
+PNG_EXTERN PNG_FUNCTION(png_voidp,png_create_struct_2,
+   PNGARG((int type, png_malloc_ptr malloc_fn, png_voidp mem_ptr)),
+   PNG_ALLOCATED);
+PNG_EXTERN void png_destroy_struct_2 PNGARG((png_voidp struct_ptr,
+    png_free_ptr free_fn, png_voidp mem_ptr));
+/* Free any memory that info_ptr points to and reset struct. */
+PNG_EXTERN void png_info_destroy PNGARG((png_structp png_ptr,
+    png_infop info_ptr));
+/* Function to allocate memory for zlib.  PNGAPI is disallowed. */
+PNG_EXTERN PNG_FUNCTION(voidpf,png_zalloc,PNGARG((voidpf png_ptr, uInt items,
+   uInt size)),PNG_ALLOCATED);
+/* Function to free memory for zlib.  PNGAPI is disallowed. */
+PNG_EXTERN void png_zfree PNGARG((voidpf png_ptr, voidpf ptr));
+/* Next four functions are used internally as callbacks.  PNGCBAPI is required
+ * but not PNG_EXPORT.  PNGAPI added at libpng version 1.2.3, changed to
+ * PNGCBAPI at 1.5.0
+ */
+PNG_EXTERN void PNGCBAPI png_default_read_data PNGARG((png_structp png_ptr,
+    png_bytep data, png_size_t length));
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+PNG_EXTERN void PNGCBAPI png_push_fill_buffer PNGARG((png_structp png_ptr,
+    png_bytep buffer, png_size_t length));
+#endif
+PNG_EXTERN void PNGCBAPI png_default_write_data PNGARG((png_structp png_ptr,
+    png_bytep data, png_size_t length));
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+#  ifdef PNG_STDIO_SUPPORTED
+PNG_EXTERN void PNGCBAPI png_default_flush PNGARG((png_structp png_ptr));
+#  endif
+#endif
+/* Reset the CRC variable */
+PNG_EXTERN void png_reset_crc PNGARG((png_structp png_ptr));
+/* Write the "data" buffer to whatever output you are using */
+PNG_EXTERN void png_write_data PNGARG((png_structp png_ptr,
+    png_const_bytep data, png_size_t length));
+/* Read and check the PNG file signature */
+PNG_EXTERN void png_read_sig PNGARG((png_structp png_ptr, png_infop info_ptr));
+/* Read the chunk header (length + type name) */
+PNG_EXTERN png_uint_32 png_read_chunk_header PNGARG((png_structp png_ptr));
+/* Read data from whatever input you are using into the "data" buffer */
+PNG_EXTERN void png_read_data PNGARG((png_structp png_ptr, png_bytep data,
+    png_size_t length));
+/* Read bytes into buf, and update png_ptr->crc */
+PNG_EXTERN void png_crc_read PNGARG((png_structp png_ptr, png_bytep buf,
+    png_size_t length));
+/* Decompress data in a chunk that uses compression */
+#if defined(PNG_READ_COMPRESSED_TEXT_SUPPORTED)
+PNG_EXTERN void png_decompress_chunk PNGARG((png_structp png_ptr,
+    int comp_type, png_size_t chunklength, png_size_t prefix_length,
+    png_size_t *data_length));
+#endif
+/* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */
+PNG_EXTERN int png_crc_finish PNGARG((png_structp png_ptr, png_uint_32 skip));
+/* Read the CRC from the file and compare it to the libpng calculated CRC */
+PNG_EXTERN int png_crc_error PNGARG((png_structp png_ptr));
+/* Calculate the CRC over a section of data.  Note that we are only
+ * passing a maximum of 64K on systems that have this as a memory limit,
+ * since this is the maximum buffer size we can specify.
+ */
+PNG_EXTERN void png_calculate_crc PNGARG((png_structp png_ptr,
+    png_const_bytep ptr, png_size_t length));
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+PNG_EXTERN void png_flush PNGARG((png_structp png_ptr));
+#endif
+/* Write various chunks */
+/* Write the IHDR chunk, and update the png_struct with the necessary
+ * information.
+ */
+PNG_EXTERN void png_write_IHDR PNGARG((png_structp png_ptr, png_uint_32 width,
+    png_uint_32 height,
+    int bit_depth, int color_type, int compression_method, int filter_method,
+    int interlace_method));
+PNG_EXTERN void png_write_PLTE PNGARG((png_structp png_ptr,
+    png_const_colorp palette, png_uint_32 num_pal));
+PNG_EXTERN void png_write_IDAT PNGARG((png_structp png_ptr, png_bytep data,
+    png_size_t length));
+PNG_EXTERN void png_write_IEND PNGARG((png_structp png_ptr));
+#ifdef PNG_WRITE_gAMA_SUPPORTED
+#  ifdef PNG_FLOATING_POINT_SUPPORTED
+PNG_EXTERN void png_write_gAMA PNGARG((png_structp png_ptr, double file_gamma));
+#  endif
+#  ifdef PNG_FIXED_POINT_SUPPORTED
+PNG_EXTERN void png_write_gAMA_fixed PNGARG((png_structp png_ptr,
+    png_fixed_point file_gamma));
+#  endif
+#endif
+#ifdef PNG_WRITE_sBIT_SUPPORTED
+PNG_EXTERN void png_write_sBIT PNGARG((png_structp png_ptr,
+    png_const_color_8p sbit, int color_type));
+#endif
+#ifdef PNG_WRITE_cHRM_SUPPORTED
+#  ifdef PNG_FLOATING_POINT_SUPPORTED
+PNG_EXTERN void png_write_cHRM PNGARG((png_structp png_ptr,
+    double white_x, double white_y,
+    double red_x, double red_y, double green_x, double green_y,
+    double blue_x, double blue_y));
+#  endif
+PNG_EXTERN void png_write_cHRM_fixed PNGARG((png_structp png_ptr,
+    png_fixed_point int_white_x, png_fixed_point int_white_y,
+    png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
+    int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
+    png_fixed_point int_blue_y));
+#endif
+#ifdef PNG_WRITE_sRGB_SUPPORTED
+PNG_EXTERN void png_write_sRGB PNGARG((png_structp png_ptr,
+    int intent));
+#endif
+#ifdef PNG_WRITE_iCCP_SUPPORTED
+PNG_EXTERN void png_write_iCCP PNGARG((png_structp png_ptr,
+    png_const_charp name, int compression_type,
+    png_const_charp profile, int proflen));
+   /* Note to maintainer: profile should be png_bytep */
+#endif
+#ifdef PNG_WRITE_sPLT_SUPPORTED
+PNG_EXTERN void png_write_sPLT PNGARG((png_structp png_ptr,
+    png_const_sPLT_tp palette));
+#endif
+#ifdef PNG_WRITE_tRNS_SUPPORTED
+PNG_EXTERN void png_write_tRNS PNGARG((png_structp png_ptr,
+    png_const_bytep trans, png_const_color_16p values, int number,
+    int color_type));
+#endif
+#ifdef PNG_WRITE_bKGD_SUPPORTED
+PNG_EXTERN void png_write_bKGD PNGARG((png_structp png_ptr,
+    png_const_color_16p values, int color_type));
+#endif
+#ifdef PNG_WRITE_hIST_SUPPORTED
+PNG_EXTERN void png_write_hIST PNGARG((png_structp png_ptr,
+    png_const_uint_16p hist, int num_hist));
+#endif
+/* Chunks that have keywords */
+#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \
+    defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
+PNG_EXTERN png_size_t png_check_keyword PNGARG((png_structp png_ptr,
+    png_const_charp key, png_charpp new_key));
+#endif
+#ifdef PNG_WRITE_tEXt_SUPPORTED
+PNG_EXTERN void png_write_tEXt PNGARG((png_structp png_ptr, png_const_charp key,
+    png_const_charp text, png_size_t text_len));
+#endif
+#ifdef PNG_WRITE_zTXt_SUPPORTED
+PNG_EXTERN void png_write_zTXt PNGARG((png_structp png_ptr, png_const_charp key,
+    png_const_charp text, png_size_t text_len, int compression));
+#endif
+#ifdef PNG_WRITE_iTXt_SUPPORTED
+PNG_EXTERN void png_write_iTXt PNGARG((png_structp png_ptr,
+    int compression, png_const_charp key, png_const_charp lang,
+    png_const_charp lang_key, png_const_charp text));
+#endif
+#ifdef PNG_TEXT_SUPPORTED  /* Added at version 1.0.14 and 1.2.4 */
+PNG_EXTERN int png_set_text_2 PNGARG((png_structp png_ptr,
+    png_infop info_ptr, png_const_textp text_ptr, int num_text));
+#endif
+#ifdef PNG_WRITE_oFFs_SUPPORTED
+PNG_EXTERN void png_write_oFFs PNGARG((png_structp png_ptr,
+    png_int_32 x_offset, png_int_32 y_offset, int unit_type));
+#endif
+#ifdef PNG_WRITE_pCAL_SUPPORTED
+PNG_EXTERN void png_write_pCAL PNGARG((png_structp png_ptr, png_charp purpose,
+    png_int_32 X0, png_int_32 X1, int type, int nparams,
+    png_const_charp units, png_charpp params));
+#endif
+#ifdef PNG_WRITE_pHYs_SUPPORTED
+PNG_EXTERN void png_write_pHYs PNGARG((png_structp png_ptr,
+    png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit,
+    int unit_type));
+#endif
+#ifdef PNG_WRITE_tIME_SUPPORTED
+PNG_EXTERN void png_write_tIME PNGARG((png_structp png_ptr,
+    png_const_timep mod_time));
+#endif
+#ifdef PNG_WRITE_sCAL_SUPPORTED
+PNG_EXTERN void png_write_sCAL_s PNGARG((png_structp png_ptr,
+    int unit, png_const_charp width, png_const_charp height));
+#endif
+/* Called when finished processing a row of data */
+PNG_EXTERN void png_write_finish_row PNGARG((png_structp png_ptr));
+/* Internal use only.   Called before first row of data */
+PNG_EXTERN void png_write_start_row PNGARG((png_structp png_ptr));
+/* Combine a row of data, dealing with alpha, etc. if requested.  'row' is an
+ * array of png_ptr->width pixels.  If the image is not interlaced or this
+ * is the final pass this just does a png_memcpy, otherwise the "display" flag
+ * is used to determine whether to copy pixels that are not in the current pass.
+ *
+ * Because 'png_do_read_interlace' (below) replicates pixels this allows this
+ * function to achieve the documented 'blocky' appearance during interlaced read
+ * if display is 1 and the 'sparkle' appearance, where existing pixels in 'row'
+ * are not changed if they are not in the current pass, when display is 0.
+ *
+ * 'display' must be 0 or 1, otherwise the memcpy will be done regardless.
+ *
+ * The API always reads from the png_struct row buffer and always assumes that
+ * it is full width (png_do_read_interlace has already been called.)
+ *
+ * This function is only ever used to write to row buffers provided by the
+ * caller of the relevant libpng API and the row must have already been
+ * transformed by the read transformations.
+ *
+ * The PNG_USE_COMPILE_TIME_MASKS option causes generation of pre-computed
+ * bitmasks for use within the code, otherwise runtime generated masks are used.
+ * The default is compile time masks.
+ */
+#ifndef PNG_USE_COMPILE_TIME_MASKS
+#  define PNG_USE_COMPILE_TIME_MASKS 1
+#endif
+PNG_EXTERN void png_combine_row PNGARG((png_structp png_ptr, png_bytep row,
+    int display));
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+/* Expand an interlaced row: the 'row_info' describes the pass data that has
+ * been read in and must correspond to the pixels in 'row', the pixels are
+ * expanded (moved apart) in 'row' to match the final layout, when doing this
+ * the pixels are *replicated* to the intervening space.  This is essential for
+ * the correct operation of png_combine_row, above.
+ */
+PNG_EXTERN void png_do_read_interlace PNGARG((png_row_infop row_info,
+    png_bytep row, int pass, png_uint_32 transformations));
+#endif
+/* GRR TO DO (2.0 or whenever):  simplify other internal calling interfaces */
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+/* Grab pixels out of a row for an interlaced pass */
+PNG_EXTERN void png_do_write_interlace PNGARG((png_row_infop row_info,
+    png_bytep row, int pass));
+#endif
+/* Unfilter a row: check the filter value before calling this, there is no point
+ * calling it for PNG_FILTER_VALUE_NONE.
+ */
+PNG_EXTERN void png_read_filter_row PNGARG((png_structp pp, png_row_infop row_info,
+    png_bytep row, png_const_bytep prev_row, int filter));
+PNG_EXTERN void png_read_filter_row_up_neon PNGARG((png_row_infop row_info,
+    png_bytep row, png_const_bytep prev_row));
+PNG_EXTERN void png_read_filter_row_sub3_neon PNGARG((png_row_infop row_info,
+    png_bytep row, png_const_bytep prev_row));
+PNG_EXTERN void png_read_filter_row_sub4_neon PNGARG((png_row_infop row_info,
+    png_bytep row, png_const_bytep prev_row));
+PNG_EXTERN void png_read_filter_row_avg3_neon PNGARG((png_row_infop row_info,
+    png_bytep row, png_const_bytep prev_row));
+PNG_EXTERN void png_read_filter_row_avg4_neon PNGARG((png_row_infop row_info,
+    png_bytep row, png_const_bytep prev_row));
+PNG_EXTERN void png_read_filter_row_paeth3_neon PNGARG((png_row_infop row_info,
+    png_bytep row, png_const_bytep prev_row));
+PNG_EXTERN void png_read_filter_row_paeth4_neon PNGARG((png_row_infop row_info,
+    png_bytep row, png_const_bytep prev_row));
+/* Choose the best filter to use and filter the row data */
+PNG_EXTERN void png_write_find_filter PNGARG((png_structp png_ptr,
+    png_row_infop row_info));
+/* Finish a row while reading, dealing with interlacing passes, etc. */
+PNG_EXTERN void png_read_finish_row PNGARG((png_structp png_ptr));
+/* Initialize the row buffers, etc. */
+PNG_EXTERN void png_read_start_row PNGARG((png_structp png_ptr));
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+/* Optional call to update the users info structure */
+PNG_EXTERN void png_read_transform_info PNGARG((png_structp png_ptr,
+    png_infop info_ptr));
+#endif
+/* These are the functions that do the transformations */
+#ifdef PNG_READ_FILLER_SUPPORTED
+PNG_EXTERN void png_do_read_filler PNGARG((png_row_infop row_info,
+    png_bytep row, png_uint_32 filler, png_uint_32 flags));
+#endif
+#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
+PNG_EXTERN void png_do_read_swap_alpha PNGARG((png_row_infop row_info,
+    png_bytep row));
+#endif
+#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
+PNG_EXTERN void png_do_write_swap_alpha PNGARG((png_row_infop row_info,
+    png_bytep row));
+#endif
+#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
+PNG_EXTERN void png_do_read_invert_alpha PNGARG((png_row_infop row_info,
+    png_bytep row));
+#endif
+#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
+PNG_EXTERN void png_do_write_invert_alpha PNGARG((png_row_infop row_info,
+    png_bytep row));
+#endif
+#if defined(PNG_WRITE_FILLER_SUPPORTED) || \
+    defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
+PNG_EXTERN void png_do_strip_channel PNGARG((png_row_infop row_info,
+    png_bytep row, int at_start));
+#endif
+#ifdef PNG_16BIT_SUPPORTED
+#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
+PNG_EXTERN void png_do_swap PNGARG((png_row_infop row_info,
+    png_bytep row));
+#endif
+#endif
+#if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
+    defined(PNG_WRITE_PACKSWAP_SUPPORTED)
+PNG_EXTERN void png_do_packswap PNGARG((png_row_infop row_info,
+    png_bytep row));
+#endif
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+PNG_EXTERN int png_do_rgb_to_gray PNGARG((png_structp png_ptr,
+    png_row_infop row_info, png_bytep row));
+#endif
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+PNG_EXTERN void png_do_gray_to_rgb PNGARG((png_row_infop row_info,
+    png_bytep row));
+#endif
+#ifdef PNG_READ_PACK_SUPPORTED
+PNG_EXTERN void png_do_unpack PNGARG((png_row_infop row_info,
+    png_bytep row));
+#endif
+#ifdef PNG_READ_SHIFT_SUPPORTED
+PNG_EXTERN void png_do_unshift PNGARG((png_row_infop row_info,
+    png_bytep row, png_const_color_8p sig_bits));
+#endif
+#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
+PNG_EXTERN void png_do_invert PNGARG((png_row_infop row_info,
+    png_bytep row));
+#endif
+#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+PNG_EXTERN void png_do_scale_16_to_8 PNGARG((png_row_infop row_info,
+    png_bytep row));
+#endif
+#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
+PNG_EXTERN void png_do_chop PNGARG((png_row_infop row_info,
+    png_bytep row));
+#endif
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+PNG_EXTERN void png_do_quantize PNGARG((png_row_infop row_info,
+    png_bytep row, png_const_bytep palette_lookup,
+    png_const_bytep quantize_lookup));
+#  ifdef PNG_CORRECT_PALETTE_SUPPORTED
+PNG_EXTERN void png_correct_palette PNGARG((png_structp png_ptr,
+    png_colorp palette, int num_palette));
+#  endif
+#endif
+#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
+PNG_EXTERN void png_do_bgr PNGARG((png_row_infop row_info,
+    png_bytep row));
+#endif
+#ifdef PNG_WRITE_PACK_SUPPORTED
+PNG_EXTERN void png_do_pack PNGARG((png_row_infop row_info,
+   png_bytep row, png_uint_32 bit_depth));
+#endif
+#ifdef PNG_WRITE_SHIFT_SUPPORTED
+PNG_EXTERN void png_do_shift PNGARG((png_row_infop row_info,
+    png_bytep row, png_const_color_8p bit_depth));
+#endif
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
+    defined(PNG_READ_ALPHA_MODE_SUPPORTED)
+PNG_EXTERN void png_do_compose PNGARG((png_row_infop row_info,
+    png_bytep row, png_structp png_ptr));
+#endif
+#ifdef PNG_READ_GAMMA_SUPPORTED
+PNG_EXTERN void png_do_gamma PNGARG((png_row_infop row_info,
+    png_bytep row, png_structp png_ptr));
+#endif
+#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+PNG_EXTERN void png_do_encode_alpha PNGARG((png_row_infop row_info,
+   png_bytep row, png_structp png_ptr));
+#endif
+#ifdef PNG_READ_EXPAND_SUPPORTED
+PNG_EXTERN void png_do_expand_palette PNGARG((png_row_infop row_info,
+    png_bytep row, png_const_colorp palette, png_const_bytep trans,
+    int num_trans));
+PNG_EXTERN void png_do_expand PNGARG((png_row_infop row_info,
+    png_bytep row, png_const_color_16p trans_color));
+#endif
+#ifdef PNG_READ_EXPAND_16_SUPPORTED
+PNG_EXTERN void png_do_expand_16 PNGARG((png_row_infop row_info,
+    png_bytep row));
+#endif
+/* The following decodes the appropriate chunks, and does error correction,
+ * then calls the appropriate callback for the chunk if it is valid.
+ */
+/* Decode the IHDR chunk */
+PNG_EXTERN void png_handle_IHDR PNGARG((png_structp png_ptr, png_infop info_ptr,
+    png_uint_32 length));
+PNG_EXTERN void png_handle_PLTE PNGARG((png_structp png_ptr, png_infop info_ptr,
+    png_uint_32 length));
+PNG_EXTERN void png_handle_IEND PNGARG((png_structp png_ptr, png_infop info_ptr,
+    png_uint_32 length));
+#ifdef PNG_READ_bKGD_SUPPORTED
+PNG_EXTERN void png_handle_bKGD PNGARG((png_structp png_ptr, png_infop info_ptr,
+    png_uint_32 length));
+#endif
+#ifdef PNG_READ_cHRM_SUPPORTED
+PNG_EXTERN void png_handle_cHRM PNGARG((png_structp png_ptr, png_infop info_ptr,
+    png_uint_32 length));
+#endif
+#ifdef PNG_READ_gAMA_SUPPORTED
+PNG_EXTERN void png_handle_gAMA PNGARG((png_structp png_ptr, png_infop info_ptr,
+    png_uint_32 length));
+#endif
+#ifdef PNG_READ_hIST_SUPPORTED
+PNG_EXTERN void png_handle_hIST PNGARG((png_structp png_ptr, png_infop info_ptr,
+    png_uint_32 length));
+#endif
+#ifdef PNG_READ_iCCP_SUPPORTED
+PNG_EXTERN void png_handle_iCCP PNGARG((png_structp png_ptr, png_infop info_ptr,
+    png_uint_32 length));
+#endif /* PNG_READ_iCCP_SUPPORTED */
+#ifdef PNG_READ_iTXt_SUPPORTED
+PNG_EXTERN void png_handle_iTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
+    png_uint_32 length));
+#endif
+#ifdef PNG_READ_oFFs_SUPPORTED
+PNG_EXTERN void png_handle_oFFs PNGARG((png_structp png_ptr, png_infop info_ptr,
+    png_uint_32 length));
+#endif
+#ifdef PNG_READ_pCAL_SUPPORTED
+PNG_EXTERN void png_handle_pCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
+    png_uint_32 length));
+#endif
+#ifdef PNG_READ_pHYs_SUPPORTED
+PNG_EXTERN void png_handle_pHYs PNGARG((png_structp png_ptr, png_infop info_ptr,
+    png_uint_32 length));
+#endif
+#ifdef PNG_READ_sBIT_SUPPORTED
+PNG_EXTERN void png_handle_sBIT PNGARG((png_structp png_ptr, png_infop info_ptr,
+    png_uint_32 length));
+#endif
+#ifdef PNG_READ_sCAL_SUPPORTED
+PNG_EXTERN void png_handle_sCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
+    png_uint_32 length));
+#endif
+#ifdef PNG_READ_sPLT_SUPPORTED
+PNG_EXTERN void png_handle_sPLT PNGARG((png_structp png_ptr, png_infop info_ptr,
+    png_uint_32 length));
+#endif /* PNG_READ_sPLT_SUPPORTED */
+#ifdef PNG_READ_sRGB_SUPPORTED
+PNG_EXTERN void png_handle_sRGB PNGARG((png_structp png_ptr, png_infop info_ptr,
+    png_uint_32 length));
+#endif
+#ifdef PNG_READ_tEXt_SUPPORTED
+PNG_EXTERN void png_handle_tEXt PNGARG((png_structp png_ptr, png_infop info_ptr,
+    png_uint_32 length));
+#endif
+#ifdef PNG_READ_tIME_SUPPORTED
+PNG_EXTERN void png_handle_tIME PNGARG((png_structp png_ptr, png_infop info_ptr,
+    png_uint_32 length));
+#endif
+#ifdef PNG_READ_tRNS_SUPPORTED
+PNG_EXTERN void png_handle_tRNS PNGARG((png_structp png_ptr, png_infop info_ptr,
+    png_uint_32 length));
+#endif
+#ifdef PNG_READ_zTXt_SUPPORTED
+PNG_EXTERN void png_handle_zTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
+    png_uint_32 length));
+#endif
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+PNG_EXTERN void png_handle_unknown PNGARG((png_structp png_ptr,
+    png_infop info_ptr, png_uint_32 length));
+#endif
+PNG_EXTERN void png_check_chunk_name PNGARG((png_structp png_ptr,
+    png_uint_32 chunk_name));
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+/* Exactly as png_handle_as_unknown() except that the argument is a 32-bit chunk
+ * name, not a string.
+ */
+PNG_EXTERN int png_chunk_unknown_handling PNGARG((png_structp png_ptr,
+    png_uint_32 chunk_name));
+#endif
+/* Handle the transformations for reading and writing */
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+PNG_EXTERN void png_do_read_transformations PNGARG((png_structp png_ptr,
+   png_row_infop row_info));
+#endif
+#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
+PNG_EXTERN void png_do_write_transformations PNGARG((png_structp png_ptr,
+   png_row_infop row_info));
+#endif
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+PNG_EXTERN void png_init_read_transformations PNGARG((png_structp png_ptr));
+#endif
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+PNG_EXTERN void png_push_read_chunk PNGARG((png_structp png_ptr,
+    png_infop info_ptr));
+PNG_EXTERN void png_push_read_sig PNGARG((png_structp png_ptr,
+    png_infop info_ptr));
+PNG_EXTERN void png_push_check_crc PNGARG((png_structp png_ptr));
+PNG_EXTERN void png_push_crc_skip PNGARG((png_structp png_ptr,
+    png_uint_32 length));
+PNG_EXTERN void png_push_crc_finish PNGARG((png_structp png_ptr));
+PNG_EXTERN void png_push_save_buffer PNGARG((png_structp png_ptr));
+PNG_EXTERN void png_push_restore_buffer PNGARG((png_structp png_ptr,
+    png_bytep buffer, png_size_t buffer_length));
+PNG_EXTERN void png_push_read_IDAT PNGARG((png_structp png_ptr));
+PNG_EXTERN void png_process_IDAT_data PNGARG((png_structp png_ptr,
+    png_bytep buffer, png_size_t buffer_length));
+PNG_EXTERN void png_push_process_row PNGARG((png_structp png_ptr));
+PNG_EXTERN void png_push_handle_unknown PNGARG((png_structp png_ptr,
+   png_infop info_ptr, png_uint_32 length));
+PNG_EXTERN void png_push_have_info PNGARG((png_structp png_ptr,
+   png_infop info_ptr));
+PNG_EXTERN void png_push_have_end PNGARG((png_structp png_ptr,
+   png_infop info_ptr));
+PNG_EXTERN void png_push_have_row PNGARG((png_structp png_ptr, png_bytep row));
+PNG_EXTERN void png_push_read_end PNGARG((png_structp png_ptr,
+    png_infop info_ptr));
+PNG_EXTERN void png_process_some_data PNGARG((png_structp png_ptr,
+    png_infop info_ptr));
+PNG_EXTERN void png_read_push_finish_row PNGARG((png_structp png_ptr));
+#  ifdef PNG_READ_tEXt_SUPPORTED
+PNG_EXTERN void png_push_handle_tEXt PNGARG((png_structp png_ptr,
+    png_infop info_ptr, png_uint_32 length));
+PNG_EXTERN void png_push_read_tEXt PNGARG((png_structp png_ptr,
+    png_infop info_ptr));
+#  endif
+#  ifdef PNG_READ_zTXt_SUPPORTED
+PNG_EXTERN void png_push_handle_zTXt PNGARG((png_structp png_ptr,
+    png_infop info_ptr, png_uint_32 length));
+PNG_EXTERN void png_push_read_zTXt PNGARG((png_structp png_ptr,
+    png_infop info_ptr));
+#  endif
+#  ifdef PNG_READ_iTXt_SUPPORTED
+PNG_EXTERN void png_push_handle_iTXt PNGARG((png_structp png_ptr,
+    png_infop info_ptr, png_uint_32 length));
+PNG_EXTERN void png_push_read_iTXt PNGARG((png_structp png_ptr,
+    png_infop info_ptr));
+#  endif
+#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+PNG_EXTERN void png_do_read_intrapixel PNGARG((png_row_infop row_info,
+    png_bytep row));
+PNG_EXTERN void png_do_write_intrapixel PNGARG((png_row_infop row_info,
+    png_bytep row));
+#endif
+/* Added at libpng version 1.4.0 */
+#ifdef PNG_CHECK_cHRM_SUPPORTED
+PNG_EXTERN int png_check_cHRM_fixed PNGARG((png_structp png_ptr,
+    png_fixed_point int_white_x, png_fixed_point int_white_y,
+    png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
+    int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
+    png_fixed_point int_blue_y));
+#endif
+#ifdef PNG_CHECK_cHRM_SUPPORTED
+/* Added at libpng version 1.2.34 and 1.4.0 */
+/* Currently only used by png_check_cHRM_fixed */
+PNG_EXTERN void png_64bit_product PNGARG((long v1, long v2,
+    unsigned long *hi_product, unsigned long *lo_product));
+#endif
+#ifdef PNG_cHRM_SUPPORTED
+/* Added at libpng version 1.5.5 */
+typedef struct png_xy
+{
+   png_fixed_point redx, redy;
+   png_fixed_point greenx, greeny;
+   png_fixed_point bluex, bluey;
+   png_fixed_point whitex, whitey;
+} png_xy;
+typedef struct png_XYZ
+{
+   png_fixed_point redX, redY, redZ;
+   png_fixed_point greenX, greenY, greenZ;
+   png_fixed_point blueX, blueY, blueZ;
+} png_XYZ;
+/* The conversion APIs return 0 on success, non-zero on a parameter error. They
+ * allow conversion between the above representations of a color encoding.  When
+ * converting from XYZ end points to chromaticities the absolute magnitude of
+ * the end points is lost, when converting back the sum of the Y values of the
+ * three end points will be 1.0
+ */
+PNG_EXTERN int png_xy_from_XYZ PNGARG((png_xy *xy, png_XYZ XYZ));
+PNG_EXTERN int png_XYZ_from_xy PNGARG((png_XYZ *XYZ, png_xy xy));
+PNG_EXTERN int png_XYZ_from_xy_checked PNGARG((png_structp png_ptr,
+   png_XYZ *XYZ, png_xy xy));
+#endif
+/* Added at libpng version 1.4.0 */
+PNG_EXTERN void png_check_IHDR PNGARG((png_structp png_ptr,
+    png_uint_32 width, png_uint_32 height, int bit_depth,
+    int color_type, int interlace_type, int compression_type,
+    int filter_type));
+/* Free all memory used by the read (old method - NOT DLL EXPORTED) */
+PNG_EXTERN void png_read_destroy PNGARG((png_structp png_ptr,
+    png_infop info_ptr, png_infop end_info_ptr));
+/* Free any memory used in png_ptr struct (old method - NOT DLL EXPORTED) */
+PNG_EXTERN void png_write_destroy PNGARG((png_structp png_ptr));
+#ifdef USE_FAR_KEYWORD  /* memory model conversion function */
+PNG_EXTERN void *png_far_to_near PNGARG((png_structp png_ptr, png_voidp ptr,
+    int check));
+#endif /* USE_FAR_KEYWORD */
+#if defined(PNG_FLOATING_POINT_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED)
+PNG_EXTERN PNG_FUNCTION(void, png_fixed_error, (png_structp png_ptr,
+   png_const_charp name),PNG_NORETURN);
+#endif
+/* Puts 'string' into 'buffer' at buffer[pos], taking care never to overwrite
+ * the end.  Always leaves the buffer nul terminated.  Never errors out (and
+ * there is no error code.)
+ */
+PNG_EXTERN size_t png_safecat(png_charp buffer, size_t bufsize, size_t pos,
+    png_const_charp string);
+/* Various internal functions to handle formatted warning messages, currently
+ * only implemented for warnings.
+ */
+#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_SUPPORTED)
+/* Utility to dump an unsigned value into a buffer, given a start pointer and
+ * and end pointer (which should point just *beyond* the end of the buffer!)
+ * Returns the pointer to the start of the formatted string.  This utility only
+ * does unsigned values.
+ */
+PNG_EXTERN png_charp png_format_number(png_const_charp start, png_charp end,
+   int format, png_alloc_size_t number);
+/* Convenience macro that takes an array: */
+#define PNG_FORMAT_NUMBER(buffer,format,number) \
+   png_format_number(buffer, buffer + (sizeof buffer), format, number)
+/* Suggested size for a number buffer (enough for 64 bits and a sign!) */
+#define PNG_NUMBER_BUFFER_SIZE 24
+/* These are the integer formats currently supported, the name is formed from
+ * the standard printf(3) format string.
+ */
+#define PNG_NUMBER_FORMAT_u     1 /* chose unsigned API! */
+#define PNG_NUMBER_FORMAT_02u   2
+#define PNG_NUMBER_FORMAT_d     1 /* chose signed API! */
+#define PNG_NUMBER_FORMAT_02d   2
+#define PNG_NUMBER_FORMAT_x     3
+#define PNG_NUMBER_FORMAT_02x   4
+#define PNG_NUMBER_FORMAT_fixed 5 /* choose the signed API */
+#endif
+#ifdef PNG_WARNINGS_SUPPORTED
+/* New defines and members adding in libpng-1.5.4 */
+#  define PNG_WARNING_PARAMETER_SIZE 32
+#  define PNG_WARNING_PARAMETER_COUNT 8
+/* An l-value of this type has to be passed to the APIs below to cache the
+ * values of the parameters to a formatted warning message.
+ */
+typedef char png_warning_parameters[PNG_WARNING_PARAMETER_COUNT][
+   PNG_WARNING_PARAMETER_SIZE];
+PNG_EXTERN void png_warning_parameter(png_warning_parameters p, int number,
+    png_const_charp string);
+    /* Parameters are limited in size to PNG_WARNING_PARAMETER_SIZE characters,
+     * including the trailing '\0'.
+     */
+PNG_EXTERN void png_warning_parameter_unsigned(png_warning_parameters p,
+    int number, int format, png_alloc_size_t value);
+    /* Use png_alloc_size_t because it is an unsigned type as big as any we
+     * need to output.  Use the following for a signed value.
+     */
+PNG_EXTERN void png_warning_parameter_signed(png_warning_parameters p,
+    int number, int format, png_int_32 value);
+PNG_EXTERN void png_formatted_warning(png_structp png_ptr,
+    png_warning_parameters p, png_const_charp message);
+    /* 'message' follows the X/Open approach of using @1, @2 to insert
+     * parameters previously supplied using the above functions.  Errors in
+     * specifying the paramters will simple result in garbage substitutions.
+     */
+#endif
+/* ASCII to FP interfaces, currently only implemented if sCAL
+ * support is required.
+ */
+#if defined(PNG_READ_sCAL_SUPPORTED)
+/* MAX_DIGITS is actually the maximum number of characters in an sCAL
+ * width or height, derived from the precision (number of significant
+ * digits - a build time settable option) and assumpitions about the
+ * maximum ridiculous exponent.
+ */
+#define PNG_sCAL_MAX_DIGITS (PNG_sCAL_PRECISION+1/*.*/+1/*E*/+10/*exponent*/)
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+PNG_EXTERN void png_ascii_from_fp PNGARG((png_structp png_ptr, png_charp ascii,
+    png_size_t size, double fp, unsigned int precision));
+#endif /* FLOATING_POINT */
+#ifdef PNG_FIXED_POINT_SUPPORTED
+PNG_EXTERN void png_ascii_from_fixed PNGARG((png_structp png_ptr,
+    png_charp ascii, png_size_t size, png_fixed_point fp));
+#endif /* FIXED_POINT */
+#endif /* READ_sCAL */
+#if defined(PNG_sCAL_SUPPORTED) || defined(PNG_pCAL_SUPPORTED)
+/* An internal API to validate the format of a floating point number.
+ * The result is the index of the next character.  If the number is
+ * not valid it will be the index of a character in the supposed number.
+ *
+ * The format of a number is defined in the PNG extensions specification
+ * and this API is strictly conformant to that spec, not anyone elses!
+ *
+ * The format as a regular expression is:
+ *
+ * [+-]?[0-9]+.?([Ee][+-]?[0-9]+)?
+ *
+ * or:
+ *
+ * [+-]?.[0-9]+(.[0-9]+)?([Ee][+-]?[0-9]+)?
+ *
+ * The complexity is that either integer or fraction must be present and the
+ * fraction is permitted to have no digits only if the integer is present.
+ *
+ * NOTE: The dangling E problem.
+ *   There is a PNG valid floating point number in the following:
+ *
+ *       PNG floating point numb1.ers are not greedy.
+ *
+ *   Working this out requires *TWO* character lookahead (because of the
+ *   sign), the parser does not do this - it will fail at the 'r' - this
+ *   doesn't matter for PNG sCAL chunk values, but it requires more care
+ *   if the value were ever to be embedded in something more complex.  Use
+ *   ANSI-C strtod if you need the lookahead.
+ */
+/* State table for the parser. */
+#define PNG_FP_INTEGER    0  /* before or in integer */
+#define PNG_FP_FRACTION   1  /* before or in fraction */
+#define PNG_FP_EXPONENT   2  /* before or in exponent */
+#define PNG_FP_STATE      3  /* mask for the above */
+#define PNG_FP_SAW_SIGN   4  /* Saw +/- in current state */
+#define PNG_FP_SAW_DIGIT  8  /* Saw a digit in current state */
+#define PNG_FP_SAW_DOT   16  /* Saw a dot in current state */
+#define PNG_FP_SAW_E     32  /* Saw an E (or e) in current state */
+#define PNG_FP_SAW_ANY   60  /* Saw any of the above 4 */
+/* These three values don't affect the parser.  They are set but not used.
+ */
+#define PNG_FP_WAS_VALID 64  /* Preceding substring is a valid fp number */
+#define PNG_FP_NEGATIVE 128  /* A negative number, including "-0" */
+#define PNG_FP_NONZERO  256  /* A non-zero value */
+#define PNG_FP_STICKY   448  /* The above three flags */
+/* This is available for the caller to store in 'state' if required.  Do not
+ * call the parser after setting it (the parser sometimes clears it.)
+ */
+#define PNG_FP_INVALID  512  /* Available for callers as a distinct value */
+/* Result codes for the parser (boolean - true meants ok, false means
+ * not ok yet.)
+ */
+#define PNG_FP_MAYBE      0  /* The number may be valid in the future */
+#define PNG_FP_OK         1  /* The number is valid */
+/* Tests on the sticky non-zero and negative flags.  To pass these checks
+ * the state must also indicate that the whole number is valid - this is
+ * achieved by testing PNG_FP_SAW_DIGIT (see the implementation for why this
+ * is equivalent to PNG_FP_OK above.)
+ */
+#define PNG_FP_NZ_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NEGATIVE | PNG_FP_NONZERO)
+   /* NZ_MASK: the string is valid and a non-zero negative value */
+#define PNG_FP_Z_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NONZERO)
+   /* Z MASK: the string is valid and a non-zero value. */
+   /* PNG_FP_SAW_DIGIT: the string is valid. */
+#define PNG_FP_IS_ZERO(state) (((state) & PNG_FP_Z_MASK) == PNG_FP_SAW_DIGIT)
+#define PNG_FP_IS_POSITIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_Z_MASK)
+#define PNG_FP_IS_NEGATIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_NZ_MASK)
+ 
+/* The actual parser.  This can be called repeatedly, it updates
+ * the index into the string and the state variable (which must
+ * be initialzed to 0).  It returns a result code, as above.  There
+ * is no point calling the parser any more if it fails to advance to
+ * the end of the string - it is stuck on an invalid character (or
+ * terminated by '\0').
+ *
+ * Note that the pointer will consume an E or even an E+ then leave
+ * a 'maybe' state even though a preceding integer.fraction is valid.
+ * The PNG_FP_WAS_VALID flag indicates that a preceding substring was
+ * a valid number.  It's possible to recover from this by calling
+ * the parser again (from the start, with state 0) but with a string
+ * that omits the last character (i.e. set the size to the index of
+ * the problem character.)  This has not been tested within libpng.
+ */
+PNG_EXTERN int png_check_fp_number PNGARG((png_const_charp string,
+    png_size_t size, int *statep, png_size_tp whereami));
+/* This is the same but it checks a complete string and returns true
+ * only if it just contains a floating point number.  As of 1.5.4 this
+ * function also returns the state at the end of parsing the number if
+ * it was valid (otherwise it returns 0.)  This can be used for testing
+ * for negative or zero values using the sticky flag.
+ */
+PNG_EXTERN int png_check_fp_string PNGARG((png_const_charp string,
+    png_size_t size));
+#endif /* pCAL || sCAL */
+#if defined(PNG_READ_GAMMA_SUPPORTED) ||\
+    defined(PNG_INCH_CONVERSIONS_SUPPORTED) || defined(PNG_READ_pHYs_SUPPORTED)
+/* Added at libpng version 1.5.0 */
+/* This is a utility to provide a*times/div (rounded) and indicate
+ * if there is an overflow.  The result is a boolean - false (0)
+ * for overflow, true (1) if no overflow, in which case *res
+ * holds the result.
+ */
+PNG_EXTERN int png_muldiv PNGARG((png_fixed_point_p res, png_fixed_point a,
+    png_int_32 multiplied_by, png_int_32 divided_by));
+#endif
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_INCH_CONVERSIONS_SUPPORTED)
+/* Same deal, but issue a warning on overflow and return 0. */
+PNG_EXTERN png_fixed_point png_muldiv_warn PNGARG((png_structp png_ptr,
+    png_fixed_point a, png_int_32 multiplied_by, png_int_32 divided_by));
+#endif
+#ifdef PNG_READ_GAMMA_SUPPORTED
+/* Calculate a reciprocal - used for gamma values.  This returns
+ * 0 if the argument is 0 in order to maintain an undefined value,
+ * there are no warnings.
+ */
+PNG_EXTERN png_fixed_point png_reciprocal PNGARG((png_fixed_point a));
+/* The same but gives a reciprocal of the product of two fixed point
+ * values.  Accuracy is suitable for gamma calculations but this is
+ * not exact - use png_muldiv for that.
+ */
+PNG_EXTERN png_fixed_point png_reciprocal2 PNGARG((png_fixed_point a,
+    png_fixed_point b));
+#endif
+#ifdef PNG_READ_GAMMA_SUPPORTED
+/* Internal fixed point gamma correction.  These APIs are called as
+ * required to convert single values - they don't need to be fast,
+ * they are not used when processing image pixel values.
+ *
+ * While the input is an 'unsigned' value it must actually be the
+ * correct bit value - 0..255 or 0..65535 as required.
+ */
+PNG_EXTERN png_uint_16 png_gamma_correct PNGARG((png_structp png_ptr,
+    unsigned int value, png_fixed_point gamma_value));
+PNG_EXTERN int png_gamma_significant PNGARG((png_fixed_point gamma_value));
+PNG_EXTERN png_uint_16 png_gamma_16bit_correct PNGARG((unsigned int value,
+    png_fixed_point gamma_value));
+PNG_EXTERN png_byte png_gamma_8bit_correct PNGARG((unsigned int value,
+    png_fixed_point gamma_value));
+PNG_EXTERN void png_destroy_gamma_table(png_structp png_ptr);
+PNG_EXTERN void png_build_gamma_table PNGARG((png_structp png_ptr,
+    int bit_depth));
+#endif
+/* Maintainer: Put new private prototypes here ^ and in libpngpf.3 */
+#include "pngdebug.h"
+#ifdef __cplusplus
+}
+#endif
+#endif /* PNGPRIV_H */
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngread.c b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngread.c
new file mode 100644
index 0000000..e2641d5
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngread.c
@@ -0,0 +1,1308 @@
+/* pngread.c - read a PNG file
+ *
+ * Last changed in libpng 1.5.7 [December 15, 2011]
+ * Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * This file contains routines that an application calls directly to
+ * read a PNG file or stream.
+ */
+#include "pngpriv.h"
+#ifdef PNG_READ_SUPPORTED
+/* Create a PNG structure for reading, and allocate any memory needed. */
+PNG_FUNCTION(png_structp,PNGAPI
+png_create_read_struct,(png_const_charp user_png_ver, png_voidp error_ptr,
+    png_error_ptr error_fn, png_error_ptr warn_fn),PNG_ALLOCATED)
+{
+#ifdef PNG_USER_MEM_SUPPORTED
+   return (png_create_read_struct_2(user_png_ver, error_ptr, error_fn,
+       warn_fn, NULL, NULL, NULL));
+}
+/* Alternate create PNG structure for reading, and allocate any memory
+ * needed.
+ */
+PNG_FUNCTION(png_structp,PNGAPI
+png_create_read_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
+    png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
+    png_malloc_ptr malloc_fn, png_free_ptr free_fn),PNG_ALLOCATED)
+{
+#endif /* PNG_USER_MEM_SUPPORTED */
+#ifdef PNG_SETJMP_SUPPORTED
+   volatile
+#endif
+   png_structp png_ptr;
+   volatile int png_cleanup_needed = 0;
+#ifdef PNG_SETJMP_SUPPORTED
+#ifdef USE_FAR_KEYWORD
+   jmp_buf tmp_jmpbuf;
+#endif
+#endif
+   png_debug(1, "in png_create_read_struct");
+#ifdef PNG_USER_MEM_SUPPORTED
+   png_ptr = (png_structp)png_create_struct_2(PNG_STRUCT_PNG,
+       malloc_fn, mem_ptr);
+#else
+   png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
+#endif
+   if (png_ptr == NULL)
+      return (NULL);
+   /* Added at libpng-1.2.6 */
+#ifdef PNG_USER_LIMITS_SUPPORTED
+   png_ptr->user_width_max = PNG_USER_WIDTH_MAX;
+   png_ptr->user_height_max = PNG_USER_HEIGHT_MAX;
+#  ifdef PNG_USER_CHUNK_CACHE_MAX
+   /* Added at libpng-1.2.43 and 1.4.0 */
+   png_ptr->user_chunk_cache_max = PNG_USER_CHUNK_CACHE_MAX;
+#  endif
+#  ifdef PNG_SET_USER_CHUNK_MALLOC_MAX
+   /* Added at libpng-1.2.43 and 1.4.1 */
+   png_ptr->user_chunk_malloc_max = PNG_USER_CHUNK_MALLOC_MAX;
+#  endif
+#endif
+#ifdef PNG_SETJMP_SUPPORTED
+/* Applications that neglect to set up their own setjmp() and then
+ * encounter a png_error() will longjmp here.  Since the jmpbuf is
+ * then meaningless we abort instead of returning.
+ */
+#ifdef USE_FAR_KEYWORD
+   if (setjmp(tmp_jmpbuf))
+#else
+   if (setjmp(png_jmpbuf(png_ptr))) /* Sets longjmp to match setjmp */
+#endif
+      PNG_ABORT();
+#ifdef USE_FAR_KEYWORD
+   png_memcpy(png_jmpbuf(png_ptr), tmp_jmpbuf, png_sizeof(jmp_buf));
+#endif
+#endif /* PNG_SETJMP_SUPPORTED */
+#ifdef PNG_USER_MEM_SUPPORTED
+   png_set_mem_fn(png_ptr, mem_ptr, malloc_fn, free_fn);
+#endif
+   png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn);
+   /* Call the general version checker (shared with read and write code): */
+   if (!png_user_version_check(png_ptr, user_png_ver))
+      png_cleanup_needed = 1;
+   if (!png_cleanup_needed)
+   {
+   /* Initialize zbuf - compression buffer */
+   png_ptr->zbuf_size = PNG_ZBUF_SIZE;
+   png_ptr->zbuf = (png_bytep)png_malloc_warn(png_ptr, png_ptr->zbuf_size);
+   if (png_ptr->zbuf == NULL)
+      png_cleanup_needed = 1;
+   }
+   png_ptr->zstream.zalloc = png_zalloc;
+   png_ptr->zstream.zfree = png_zfree;
+   png_ptr->zstream.opaque = (voidpf)png_ptr;
+   if (!png_cleanup_needed)
+   {
+      switch (inflateInit(&png_ptr->zstream))
+      {
+         case Z_OK:
+            break; /* Do nothing */
+         case Z_MEM_ERROR:
+            png_warning(png_ptr, "zlib memory error");
+            png_cleanup_needed = 1;
+            break;
+         case Z_STREAM_ERROR:
+            png_warning(png_ptr, "zlib stream error");
+            png_cleanup_needed = 1;
+            break;
+         case Z_VERSION_ERROR:
+            png_warning(png_ptr, "zlib version error");
+            png_cleanup_needed = 1;
+            break;
+         default: png_warning(png_ptr, "Unknown zlib error");
+            png_cleanup_needed = 1;
+      }
+   }
+   if (png_cleanup_needed)
+   {
+      /* Clean up PNG structure and deallocate any memory. */
+      png_free(png_ptr, png_ptr->zbuf);
+      png_ptr->zbuf = NULL;
+#ifdef PNG_USER_MEM_SUPPORTED
+      png_destroy_struct_2((png_voidp)png_ptr,
+          (png_free_ptr)free_fn, (png_voidp)mem_ptr);
+#else
+      png_destroy_struct((png_voidp)png_ptr);
+#endif
+      return (NULL);
+   }
+   png_ptr->zstream.next_out = png_ptr->zbuf;
+   png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
+   png_set_read_fn(png_ptr, NULL, NULL);
+   return (png_ptr);
+}
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+/* Read the information before the actual image data.  This has been
+ * changed in v0.90 to allow reading a file that already has the magic
+ * bytes read from the stream.  You can tell libpng how many bytes have
+ * been read from the beginning of the stream (up to the maximum of 8)
+ * via png_set_sig_bytes(), and we will only check the remaining bytes
+ * here.  The application can then have access to the signature bytes we
+ * read if it is determined that this isn't a valid PNG file.
+ */
+void PNGAPI
+png_read_info(png_structp png_ptr, png_infop info_ptr)
+{
+   png_debug(1, "in png_read_info");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+   /* Read and check the PNG file signature. */
+   png_read_sig(png_ptr, info_ptr);
+   for (;;)
+   {
+      png_uint_32 length = png_read_chunk_header(png_ptr);
+      png_uint_32 chunk_name = png_ptr->chunk_name;
+      /* This should be a binary subdivision search or a hash for
+       * matching the chunk name rather than a linear search.
+       */
+      if (chunk_name == png_IDAT)
+         if (png_ptr->mode & PNG_AFTER_IDAT)
+            png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;
+      if (chunk_name == png_IHDR)
+         png_handle_IHDR(png_ptr, info_ptr, length);
+      else if (chunk_name == png_IEND)
+         png_handle_IEND(png_ptr, info_ptr, length);
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+      else if (png_chunk_unknown_handling(png_ptr, chunk_name) !=
+         PNG_HANDLE_CHUNK_AS_DEFAULT)
+      {
+         if (chunk_name == png_IDAT)
+            png_ptr->mode |= PNG_HAVE_IDAT;
+         png_handle_unknown(png_ptr, info_ptr, length);
+         if (chunk_name == png_PLTE)
+            png_ptr->mode |= PNG_HAVE_PLTE;
+         else if (chunk_name == png_IDAT)
+         {
+            if (!(png_ptr->mode & PNG_HAVE_IHDR))
+               png_error(png_ptr, "Missing IHDR before IDAT");
+            else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
+                !(png_ptr->mode & PNG_HAVE_PLTE))
+               png_error(png_ptr, "Missing PLTE before IDAT");
+            break;
+         }
+      }
+#endif
+      else if (chunk_name == png_PLTE)
+         png_handle_PLTE(png_ptr, info_ptr, length);
+      else if (chunk_name == png_IDAT)
+      {
+         if (!(png_ptr->mode & PNG_HAVE_IHDR))
+            png_error(png_ptr, "Missing IHDR before IDAT");
+         else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
+             !(png_ptr->mode & PNG_HAVE_PLTE))
+            png_error(png_ptr, "Missing PLTE before IDAT");
+         png_ptr->idat_size = length;
+         png_ptr->mode |= PNG_HAVE_IDAT;
+         break;
+      }
+#ifdef PNG_READ_bKGD_SUPPORTED
+      else if (chunk_name == png_bKGD)
+         png_handle_bKGD(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_cHRM_SUPPORTED
+      else if (chunk_name == png_cHRM)
+         png_handle_cHRM(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_gAMA_SUPPORTED
+      else if (chunk_name == png_gAMA)
+         png_handle_gAMA(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_hIST_SUPPORTED
+      else if (chunk_name == png_hIST)
+         png_handle_hIST(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_oFFs_SUPPORTED
+      else if (chunk_name == png_oFFs)
+         png_handle_oFFs(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_pCAL_SUPPORTED
+      else if (chunk_name == png_pCAL)
+         png_handle_pCAL(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_sCAL_SUPPORTED
+      else if (chunk_name == png_sCAL)
+         png_handle_sCAL(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_pHYs_SUPPORTED
+      else if (chunk_name == png_pHYs)
+         png_handle_pHYs(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_sBIT_SUPPORTED
+      else if (chunk_name == png_sBIT)
+         png_handle_sBIT(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_sRGB_SUPPORTED
+      else if (chunk_name == png_sRGB)
+         png_handle_sRGB(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_iCCP_SUPPORTED
+      else if (chunk_name == png_iCCP)
+         png_handle_iCCP(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_sPLT_SUPPORTED
+      else if (chunk_name == png_sPLT)
+         png_handle_sPLT(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_tEXt_SUPPORTED
+      else if (chunk_name == png_tEXt)
+         png_handle_tEXt(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_tIME_SUPPORTED
+      else if (chunk_name == png_tIME)
+         png_handle_tIME(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_tRNS_SUPPORTED
+      else if (chunk_name == png_tRNS)
+         png_handle_tRNS(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_zTXt_SUPPORTED
+      else if (chunk_name == png_zTXt)
+         png_handle_zTXt(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_iTXt_SUPPORTED
+      else if (chunk_name == png_iTXt)
+         png_handle_iTXt(png_ptr, info_ptr, length);
+#endif
+      else
+         png_handle_unknown(png_ptr, info_ptr, length);
+   }
+}
+#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
+/* Optional call to update the users info_ptr structure */
+void PNGAPI
+png_read_update_info(png_structp png_ptr, png_infop info_ptr)
+{
+   png_debug(1, "in png_read_update_info");
+   if (png_ptr == NULL)
+      return;
+   png_read_start_row(png_ptr);
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+   png_read_transform_info(png_ptr, info_ptr);
+#else
+   PNG_UNUSED(info_ptr)
+#endif
+}
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+/* Initialize palette, background, etc, after transformations
+ * are set, but before any reading takes place.  This allows
+ * the user to obtain a gamma-corrected palette, for example.
+ * If the user doesn't call this, we will do it ourselves.
+ */
+void PNGAPI
+png_start_read_image(png_structp png_ptr)
+{
+   png_debug(1, "in png_start_read_image");
+   if (png_ptr != NULL)
+     png_read_start_row(png_ptr);
+}
+#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+void PNGAPI
+png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
+{
+   int ret;
+   png_row_info row_info;
+   if (png_ptr == NULL)
+      return;
+   png_debug2(1, "in png_read_row (row %lu, pass %d)",
+       (unsigned long)png_ptr->row_number, png_ptr->pass);
+   /* png_read_start_row sets the information (in particular iwidth) for this
+    * interlace pass.
+    */
+   if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
+      png_read_start_row(png_ptr);
+   /* 1.5.6: row_info moved out of png_struct to a local here. */
+   row_info.width = png_ptr->iwidth; /* NOTE: width of current interlaced row */
+   row_info.color_type = png_ptr->color_type;
+   row_info.bit_depth = png_ptr->bit_depth;
+   row_info.channels = png_ptr->channels;
+   row_info.pixel_depth = png_ptr->pixel_depth;
+   row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width);
+   if (png_ptr->row_number == 0 && png_ptr->pass == 0)
+   {
+   /* Check for transforms that have been set but were defined out */
+#if defined(PNG_WRITE_INVERT_SUPPORTED) && !defined(PNG_READ_INVERT_SUPPORTED)
+   if (png_ptr->transformations & PNG_INVERT_MONO)
+      png_warning(png_ptr, "PNG_READ_INVERT_SUPPORTED is not defined");
+#endif
+#if defined(PNG_WRITE_FILLER_SUPPORTED) && !defined(PNG_READ_FILLER_SUPPORTED)
+   if (png_ptr->transformations & PNG_FILLER)
+      png_warning(png_ptr, "PNG_READ_FILLER_SUPPORTED is not defined");
+#endif
+#if defined(PNG_WRITE_PACKSWAP_SUPPORTED) && \
+    !defined(PNG_READ_PACKSWAP_SUPPORTED)
+   if (png_ptr->transformations & PNG_PACKSWAP)
+      png_warning(png_ptr, "PNG_READ_PACKSWAP_SUPPORTED is not defined");
+#endif
+#if defined(PNG_WRITE_PACK_SUPPORTED) && !defined(PNG_READ_PACK_SUPPORTED)
+   if (png_ptr->transformations & PNG_PACK)
+      png_warning(png_ptr, "PNG_READ_PACK_SUPPORTED is not defined");
+#endif
+#if defined(PNG_WRITE_SHIFT_SUPPORTED) && !defined(PNG_READ_SHIFT_SUPPORTED)
+   if (png_ptr->transformations & PNG_SHIFT)
+      png_warning(png_ptr, "PNG_READ_SHIFT_SUPPORTED is not defined");
+#endif
+#if defined(PNG_WRITE_BGR_SUPPORTED) && !defined(PNG_READ_BGR_SUPPORTED)
+   if (png_ptr->transformations & PNG_BGR)
+      png_warning(png_ptr, "PNG_READ_BGR_SUPPORTED is not defined");
+#endif
+#if defined(PNG_WRITE_SWAP_SUPPORTED) && !defined(PNG_READ_SWAP_SUPPORTED)
+   if (png_ptr->transformations & PNG_SWAP_BYTES)
+      png_warning(png_ptr, "PNG_READ_SWAP_SUPPORTED is not defined");
+#endif
+   }
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+   /* If interlaced and we do not need a new row, combine row and return.
+    * Notice that the pixels we have from previous rows have been transformed
+    * already; we can only combine like with like (transformed or
+    * untransformed) and, because of the libpng API for interlaced images, this
+    * means we must transform before de-interlacing.
+    */
+   if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
+   {
+      switch (png_ptr->pass)
+      {
+         case 0:
+            if (png_ptr->row_number & 0x07)
+            {
+               if (dsp_row != NULL)
+                  png_combine_row(png_ptr, dsp_row, 1/*display*/);
+               png_read_finish_row(png_ptr);
+               return;
+            }
+            break;
+         case 1:
+            if ((png_ptr->row_number & 0x07) || png_ptr->width < 5)
+            {
+               if (dsp_row != NULL)
+                  png_combine_row(png_ptr, dsp_row, 1/*display*/);
+               png_read_finish_row(png_ptr);
+               return;
+            }
+            break;
+         case 2:
+            if ((png_ptr->row_number & 0x07) != 4)
+            {
+               if (dsp_row != NULL && (png_ptr->row_number & 4))
+                  png_combine_row(png_ptr, dsp_row, 1/*display*/);
+               png_read_finish_row(png_ptr);
+               return;
+            }
+            break;
+         case 3:
+            if ((png_ptr->row_number & 3) || png_ptr->width < 3)
+            {
+               if (dsp_row != NULL)
+                  png_combine_row(png_ptr, dsp_row, 1/*display*/);
+               png_read_finish_row(png_ptr);
+               return;
+            }
+            break;
+         case 4:
+            if ((png_ptr->row_number & 3) != 2)
+            {
+               if (dsp_row != NULL && (png_ptr->row_number & 2))
+                  png_combine_row(png_ptr, dsp_row, 1/*display*/);
+               png_read_finish_row(png_ptr);
+               return;
+            }
+            break;
+         case 5:
+            if ((png_ptr->row_number & 1) || png_ptr->width < 2)
+            {
+               if (dsp_row != NULL)
+                  png_combine_row(png_ptr, dsp_row, 1/*display*/);
+               png_read_finish_row(png_ptr);
+               return;
+            }
+            break;
+         default:
+         case 6:
+            if (!(png_ptr->row_number & 1))
+            {
+               png_read_finish_row(png_ptr);
+               return;
+            }
+            break;
+      }
+   }
+#endif
+   if (!(png_ptr->mode & PNG_HAVE_IDAT))
+      png_error(png_ptr, "Invalid attempt to read row data");
+   png_ptr->zstream.next_out = png_ptr->row_buf;
+   png_ptr->zstream.avail_out =
+       (uInt)(PNG_ROWBYTES(png_ptr->pixel_depth,
+       png_ptr->iwidth) + 1);
+   do
+   {
+      if (!(png_ptr->zstream.avail_in))
+      {
+         while (!png_ptr->idat_size)
+         {
+            png_crc_finish(png_ptr, 0);
+            png_ptr->idat_size = png_read_chunk_header(png_ptr);
+            if (png_ptr->chunk_name != png_IDAT)
+               png_error(png_ptr, "Not enough image data");
+         }
+         png_ptr->zstream.avail_in = (uInt)png_ptr->zbuf_size;
+         png_ptr->zstream.next_in = png_ptr->zbuf;
+         if (png_ptr->zbuf_size > png_ptr->idat_size)
+            png_ptr->zstream.avail_in = (uInt)png_ptr->idat_size;
+         png_crc_read(png_ptr, png_ptr->zbuf,
+             (png_size_t)png_ptr->zstream.avail_in);
+         png_ptr->idat_size -= png_ptr->zstream.avail_in;
+      }
+      ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
+      if (ret == Z_STREAM_END)
+      {
+         if (png_ptr->zstream.avail_out || png_ptr->zstream.avail_in ||
+            png_ptr->idat_size)
+            png_benign_error(png_ptr, "Extra compressed data");
+         png_ptr->mode |= PNG_AFTER_IDAT;
+         png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
+         break;
+      }
+      if (ret != Z_OK)
+         png_error(png_ptr, png_ptr->zstream.msg ? png_ptr->zstream.msg :
+             "Decompression error");
+   } while (png_ptr->zstream.avail_out);
+   if (png_ptr->row_buf[0] > PNG_FILTER_VALUE_NONE)
+   {
+      if (png_ptr->row_buf[0] < PNG_FILTER_VALUE_LAST)
+         png_read_filter_row(png_ptr, &row_info, png_ptr->row_buf + 1,
+            png_ptr->prev_row + 1, png_ptr->row_buf[0]);
+      else
+         png_error(png_ptr, "bad adaptive filter value");
+   }
+   /* libpng 1.5.6: the following line was copying png_ptr->rowbytes before
+    * 1.5.6, while the buffer really is this big in current versions of libpng
+    * it may not be in the future, so this was changed just to copy the
+    * interlaced count:
+    */
+   png_memcpy(png_ptr->prev_row, png_ptr->row_buf, row_info.rowbytes + 1);
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+   if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
+       (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
+   {
+      /* Intrapixel differencing */
+      png_do_read_intrapixel(&row_info, png_ptr->row_buf + 1);
+   }
+#endif
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+   if (png_ptr->transformations)
+      png_do_read_transformations(png_ptr, &row_info);
+#endif
+   /* The transformed pixel depth should match the depth now in row_info. */
+   if (png_ptr->transformed_pixel_depth == 0)
+   {
+      png_ptr->transformed_pixel_depth = row_info.pixel_depth;
+      if (row_info.pixel_depth > png_ptr->maximum_pixel_depth)
+         png_error(png_ptr, "sequential row overflow");
+   }
+   else if (png_ptr->transformed_pixel_depth != row_info.pixel_depth)
+      png_error(png_ptr, "internal sequential row size calculation error");
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+   /* Blow up interlaced rows to full size */
+   if (png_ptr->interlaced &&
+      (png_ptr->transformations & PNG_INTERLACE))
+   {
+      if (png_ptr->pass < 6)
+         png_do_read_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass,
+            png_ptr->transformations);
+      if (dsp_row != NULL)
+         png_combine_row(png_ptr, dsp_row, 1/*display*/);
+      if (row != NULL)
+         png_combine_row(png_ptr, row, 0/*row*/);
+   }
+   else
+#endif
+   {
+      if (row != NULL)
+         png_combine_row(png_ptr, row, -1/*ignored*/);
+      if (dsp_row != NULL)
+         png_combine_row(png_ptr, dsp_row, -1/*ignored*/);
+   }
+   png_read_finish_row(png_ptr);
+   if (png_ptr->read_row_fn != NULL)
+      (*(png_ptr->read_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);
+}
+#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+/* Read one or more rows of image data.  If the image is interlaced,
+ * and png_set_interlace_handling() has been called, the rows need to
+ * contain the contents of the rows from the previous pass.  If the
+ * image has alpha or transparency, and png_handle_alpha()[*] has been
+ * called, the rows contents must be initialized to the contents of the
+ * screen.
+ *
+ * "row" holds the actual image, and pixels are placed in it
+ * as they arrive.  If the image is displayed after each pass, it will
+ * appear to "sparkle" in.  "display_row" can be used to display a
+ * "chunky" progressive image, with finer detail added as it becomes
+ * available.  If you do not want this "chunky" display, you may pass
+ * NULL for display_row.  If you do not want the sparkle display, and
+ * you have not called png_handle_alpha(), you may pass NULL for rows.
+ * If you have called png_handle_alpha(), and the image has either an
+ * alpha channel or a transparency chunk, you must provide a buffer for
+ * rows.  In this case, you do not have to provide a display_row buffer
+ * also, but you may.  If the image is not interlaced, or if you have
+ * not called png_set_interlace_handling(), the display_row buffer will
+ * be ignored, so pass NULL to it.
+ *
+ * [*] png_handle_alpha() does not exist yet, as of this version of libpng
+ */
+void PNGAPI
+png_read_rows(png_structp png_ptr, png_bytepp row,
+    png_bytepp display_row, png_uint_32 num_rows)
+{
+   png_uint_32 i;
+   png_bytepp rp;
+   png_bytepp dp;
+   png_debug(1, "in png_read_rows");
+   if (png_ptr == NULL)
+      return;
+   rp = row;
+   dp = display_row;
+   if (rp != NULL && dp != NULL)
+      for (i = 0; i < num_rows; i++)
+      {
+         png_bytep rptr = *rp++;
+         png_bytep dptr = *dp++;
+         png_read_row(png_ptr, rptr, dptr);
+      }
+   else if (rp != NULL)
+      for (i = 0; i < num_rows; i++)
+      {
+         png_bytep rptr = *rp;
+         png_read_row(png_ptr, rptr, NULL);
+         rp++;
+      }
+   else if (dp != NULL)
+      for (i = 0; i < num_rows; i++)
+      {
+         png_bytep dptr = *dp;
+         png_read_row(png_ptr, NULL, dptr);
+         dp++;
+      }
+}
+#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+/* Read the entire image.  If the image has an alpha channel or a tRNS
+ * chunk, and you have called png_handle_alpha()[*], you will need to
+ * initialize the image to the current image that PNG will be overlaying.
+ * We set the num_rows again here, in case it was incorrectly set in
+ * png_read_start_row() by a call to png_read_update_info() or
+ * png_start_read_image() if png_set_interlace_handling() wasn't called
+ * prior to either of these functions like it should have been.  You can
+ * only call this function once.  If you desire to have an image for
+ * each pass of a interlaced image, use png_read_rows() instead.
+ *
+ * [*] png_handle_alpha() does not exist yet, as of this version of libpng
+ */
+void PNGAPI
+png_read_image(png_structp png_ptr, png_bytepp image)
+{
+   png_uint_32 i, image_height;
+   int pass, j;
+   png_bytepp rp;
+   png_debug(1, "in png_read_image");
+   if (png_ptr == NULL)
+      return;
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+   if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
+   {
+      pass = png_set_interlace_handling(png_ptr);
+      /* And make sure transforms are initialized. */
+      png_start_read_image(png_ptr);
+   }
+   else
+   {
+      if (png_ptr->interlaced && !(png_ptr->transformations & PNG_INTERLACE))
+      {
+         /* Caller called png_start_read_image or png_read_update_info without
+          * first turning on the PNG_INTERLACE transform.  We can fix this here,
+          * but the caller should do it!
+          */
+         png_warning(png_ptr, "Interlace handling should be turned on when "
+            "using png_read_image");
+         /* Make sure this is set correctly */
+         png_ptr->num_rows = png_ptr->height;
+      }
+      /* Obtain the pass number, which also turns on the PNG_INTERLACE flag in
+       * the above error case.
+       */
+      pass = png_set_interlace_handling(png_ptr);
+   }
+#else
+   if (png_ptr->interlaced)
+      png_error(png_ptr,
+          "Cannot read interlaced image -- interlace handler disabled");
+   pass = 1;
+#endif
+   image_height=png_ptr->height;
+   for (j = 0; j < pass; j++)
+   {
+      rp = image;
+      for (i = 0; i < image_height; i++)
+      {
+         png_read_row(png_ptr, *rp, NULL);
+         rp++;
+      }
+   }
+}
+#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+/* Read the end of the PNG file.  Will not read past the end of the
+ * file, will verify the end is accurate, and will read any comments
+ * or time information at the end of the file, if info is not NULL.
+ */
+void PNGAPI
+png_read_end(png_structp png_ptr, png_infop info_ptr)
+{
+   png_debug(1, "in png_read_end");
+   if (png_ptr == NULL)
+      return;
+   png_crc_finish(png_ptr, 0); /* Finish off CRC from last IDAT chunk */
+   do
+   {
+      png_uint_32 length = png_read_chunk_header(png_ptr);
+      png_uint_32 chunk_name = png_ptr->chunk_name;
+      if (chunk_name == png_IHDR)
+         png_handle_IHDR(png_ptr, info_ptr, length);
+      else if (chunk_name == png_IEND)
+         png_handle_IEND(png_ptr, info_ptr, length);
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+      else if (png_chunk_unknown_handling(png_ptr, chunk_name) !=
+         PNG_HANDLE_CHUNK_AS_DEFAULT)
+      {
+         if (chunk_name == png_IDAT)
+         {
+            if ((length > 0) || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
+               png_benign_error(png_ptr, "Too many IDATs found");
+         }
+         png_handle_unknown(png_ptr, info_ptr, length);
+         if (chunk_name == png_PLTE)
+            png_ptr->mode |= PNG_HAVE_PLTE;
+      }
+#endif
+      else if (chunk_name == png_IDAT)
+      {
+         /* Zero length IDATs are legal after the last IDAT has been
+          * read, but not after other chunks have been read.
+          */
+         if ((length > 0) || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
+            png_benign_error(png_ptr, "Too many IDATs found");
+         png_crc_finish(png_ptr, length);
+      }
+      else if (chunk_name == png_PLTE)
+         png_handle_PLTE(png_ptr, info_ptr, length);
+#ifdef PNG_READ_bKGD_SUPPORTED
+      else if (chunk_name == png_bKGD)
+         png_handle_bKGD(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_cHRM_SUPPORTED
+      else if (chunk_name == png_cHRM)
+         png_handle_cHRM(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_gAMA_SUPPORTED
+      else if (chunk_name == png_gAMA)
+         png_handle_gAMA(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_hIST_SUPPORTED
+      else if (chunk_name == png_hIST)
+         png_handle_hIST(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_oFFs_SUPPORTED
+      else if (chunk_name == png_oFFs)
+         png_handle_oFFs(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_pCAL_SUPPORTED
+      else if (chunk_name == png_pCAL)
+         png_handle_pCAL(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_sCAL_SUPPORTED
+      else if (chunk_name == png_sCAL)
+         png_handle_sCAL(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_pHYs_SUPPORTED
+      else if (chunk_name == png_pHYs)
+         png_handle_pHYs(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_sBIT_SUPPORTED
+      else if (chunk_name == png_sBIT)
+         png_handle_sBIT(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_sRGB_SUPPORTED
+      else if (chunk_name == png_sRGB)
+         png_handle_sRGB(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_iCCP_SUPPORTED
+      else if (chunk_name == png_iCCP)
+         png_handle_iCCP(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_sPLT_SUPPORTED
+      else if (chunk_name == png_sPLT)
+         png_handle_sPLT(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_tEXt_SUPPORTED
+      else if (chunk_name == png_tEXt)
+         png_handle_tEXt(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_tIME_SUPPORTED
+      else if (chunk_name == png_tIME)
+         png_handle_tIME(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_tRNS_SUPPORTED
+      else if (chunk_name == png_tRNS)
+         png_handle_tRNS(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_zTXt_SUPPORTED
+      else if (chunk_name == png_zTXt)
+         png_handle_zTXt(png_ptr, info_ptr, length);
+#endif
+#ifdef PNG_READ_iTXt_SUPPORTED
+      else if (chunk_name == png_iTXt)
+         png_handle_iTXt(png_ptr, info_ptr, length);
+#endif
+      else
+         png_handle_unknown(png_ptr, info_ptr, length);
+   } while (!(png_ptr->mode & PNG_HAVE_IEND));
+}
+#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
+/* Free all memory used by the read */
+void PNGAPI
+png_destroy_read_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr,
+    png_infopp end_info_ptr_ptr)
+{
+   png_structp png_ptr = NULL;
+   png_infop info_ptr = NULL, end_info_ptr = NULL;
+#ifdef PNG_USER_MEM_SUPPORTED
+   png_free_ptr free_fn = NULL;
+   png_voidp mem_ptr = NULL;
+#endif
+   png_debug(1, "in png_destroy_read_struct");
+   if (png_ptr_ptr != NULL)
+      png_ptr = *png_ptr_ptr;
+   if (png_ptr == NULL)
+      return;
+#ifdef PNG_USER_MEM_SUPPORTED
+   free_fn = png_ptr->free_fn;
+   mem_ptr = png_ptr->mem_ptr;
+#endif
+   if (info_ptr_ptr != NULL)
+      info_ptr = *info_ptr_ptr;
+   if (end_info_ptr_ptr != NULL)
+      end_info_ptr = *end_info_ptr_ptr;
+   png_read_destroy(png_ptr, info_ptr, end_info_ptr);
+   if (info_ptr != NULL)
+   {
+#ifdef PNG_TEXT_SUPPORTED
+      png_free_data(png_ptr, info_ptr, PNG_FREE_TEXT, -1);
+#endif
+#ifdef PNG_USER_MEM_SUPPORTED
+      png_destroy_struct_2((png_voidp)info_ptr, (png_free_ptr)free_fn,
+          (png_voidp)mem_ptr);
+#else
+      png_destroy_struct((png_voidp)info_ptr);
+#endif
+      *info_ptr_ptr = NULL;
+   }
+   if (end_info_ptr != NULL)
+   {
+#ifdef PNG_READ_TEXT_SUPPORTED
+      png_free_data(png_ptr, end_info_ptr, PNG_FREE_TEXT, -1);
+#endif
+#ifdef PNG_USER_MEM_SUPPORTED
+      png_destroy_struct_2((png_voidp)end_info_ptr, (png_free_ptr)free_fn,
+          (png_voidp)mem_ptr);
+#else
+      png_destroy_struct((png_voidp)end_info_ptr);
+#endif
+      *end_info_ptr_ptr = NULL;
+   }
+   if (png_ptr != NULL)
+   {
+#ifdef PNG_USER_MEM_SUPPORTED
+      png_destroy_struct_2((png_voidp)png_ptr, (png_free_ptr)free_fn,
+          (png_voidp)mem_ptr);
+#else
+      png_destroy_struct((png_voidp)png_ptr);
+#endif
+      *png_ptr_ptr = NULL;
+   }
+}
+/* Free all memory used by the read (old method) */
+void /* PRIVATE */
+png_read_destroy(png_structp png_ptr, png_infop info_ptr,
+    png_infop end_info_ptr)
+{
+#ifdef PNG_SETJMP_SUPPORTED
+   jmp_buf tmp_jmp;
+#endif
+   png_error_ptr error_fn;
+#ifdef PNG_WARNINGS_SUPPORTED
+   png_error_ptr warning_fn;
+#endif
+   png_voidp error_ptr;
+#ifdef PNG_USER_MEM_SUPPORTED
+   png_free_ptr free_fn;
+#endif
+   png_debug(1, "in png_read_destroy");
+   if (info_ptr != NULL)
+      png_info_destroy(png_ptr, info_ptr);
+   if (end_info_ptr != NULL)
+      png_info_destroy(png_ptr, end_info_ptr);
+#ifdef PNG_READ_GAMMA_SUPPORTED
+   png_destroy_gamma_table(png_ptr);
+#endif
+   png_free(png_ptr, png_ptr->zbuf);
+   png_free(png_ptr, png_ptr->big_row_buf);
+   png_free(png_ptr, png_ptr->big_prev_row);
+   png_free(png_ptr, png_ptr->chunkdata);
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+   png_free(png_ptr, png_ptr->palette_lookup);
+   png_free(png_ptr, png_ptr->quantize_index);
+#endif
+   if (png_ptr->free_me & PNG_FREE_PLTE)
+      png_zfree(png_ptr, png_ptr->palette);
+   png_ptr->free_me &= ~PNG_FREE_PLTE;
+#if defined(PNG_tRNS_SUPPORTED) || \
+    defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+   if (png_ptr->free_me & PNG_FREE_TRNS)
+      png_free(png_ptr, png_ptr->trans_alpha);
+   png_ptr->free_me &= ~PNG_FREE_TRNS;
+#endif
+#ifdef PNG_READ_hIST_SUPPORTED
+   if (png_ptr->free_me & PNG_FREE_HIST)
+      png_free(png_ptr, png_ptr->hist);
+   png_ptr->free_me &= ~PNG_FREE_HIST;
+#endif
+   inflateEnd(&png_ptr->zstream);
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+   png_free(png_ptr, png_ptr->save_buffer);
+#endif
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+#ifdef PNG_TEXT_SUPPORTED
+   png_free(png_ptr, png_ptr->current_text);
+#endif /* PNG_TEXT_SUPPORTED */
+#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
+   /* Save the important info out of the png_struct, in case it is
+    * being used again.
+    */
+#ifdef PNG_SETJMP_SUPPORTED
+   png_memcpy(tmp_jmp, png_ptr->longjmp_buffer, png_sizeof(jmp_buf));
+#endif
+   error_fn = png_ptr->error_fn;
+#ifdef PNG_WARNINGS_SUPPORTED
+   warning_fn = png_ptr->warning_fn;
+#endif
+   error_ptr = png_ptr->error_ptr;
+#ifdef PNG_USER_MEM_SUPPORTED
+   free_fn = png_ptr->free_fn;
+#endif
+   png_memset(png_ptr, 0, png_sizeof(png_struct));
+   png_ptr->error_fn = error_fn;
+#ifdef PNG_WARNINGS_SUPPORTED
+   png_ptr->warning_fn = warning_fn;
+#endif
+   png_ptr->error_ptr = error_ptr;
+#ifdef PNG_USER_MEM_SUPPORTED
+   png_ptr->free_fn = free_fn;
+#endif
+#ifdef PNG_SETJMP_SUPPORTED
+   png_memcpy(png_ptr->longjmp_buffer, tmp_jmp, png_sizeof(jmp_buf));
+#endif
+}
+void PNGAPI
+png_set_read_status_fn(png_structp png_ptr, png_read_status_ptr read_row_fn)
+{
+   if (png_ptr == NULL)
+      return;
+   png_ptr->read_row_fn = read_row_fn;
+}
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+#ifdef PNG_INFO_IMAGE_SUPPORTED
+void PNGAPI
+png_read_png(png_structp png_ptr, png_infop info_ptr,
+                           int transforms,
+                           voidp params)
+{
+   int row;
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+   /* png_read_info() gives us all of the information from the
+    * PNG file before the first IDAT (image data chunk).
+    */
+   png_read_info(png_ptr, info_ptr);
+   if (info_ptr->height > PNG_UINT_32_MAX/png_sizeof(png_bytep))
+      png_error(png_ptr, "Image is too high to process with png_read_png()");
+   /* -------------- image transformations start here ------------------- */
+#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+   /* Tell libpng to strip 16-bit/color files down to 8 bits per color.
+    */
+   if (transforms & PNG_TRANSFORM_SCALE_16)
+   {
+     /* Added at libpng-1.5.4. "strip_16" produces the same result that it
+      * did in earlier versions, while "scale_16" is now more accurate.
+      */
+      png_set_scale_16(png_ptr);
+   }
+#endif
+#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
+   /* If both SCALE and STRIP are required pngrtran will effectively cancel the
+    * latter by doing SCALE first.  This is ok and allows apps not to check for
+    * which is supported to get the right answer.
+    */
+   if (transforms & PNG_TRANSFORM_STRIP_16)
+      png_set_strip_16(png_ptr);
+#endif
+#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
+   /* Strip alpha bytes from the input data without combining with
+    * the background (not recommended).
+    */
+   if (transforms & PNG_TRANSFORM_STRIP_ALPHA)
+      png_set_strip_alpha(png_ptr);
+#endif
+#if defined(PNG_READ_PACK_SUPPORTED) && !defined(PNG_READ_EXPAND_SUPPORTED)
+   /* Extract multiple pixels with bit depths of 1, 2, or 4 from a single
+    * byte into separate bytes (useful for paletted and grayscale images).
+    */
+   if (transforms & PNG_TRANSFORM_PACKING)
+      png_set_packing(png_ptr);
+#endif
+#ifdef PNG_READ_PACKSWAP_SUPPORTED
+   /* Change the order of packed pixels to least significant bit first
+    * (not useful if you are using png_set_packing).
+    */
+   if (transforms & PNG_TRANSFORM_PACKSWAP)
+      png_set_packswap(png_ptr);
+#endif
+#ifdef PNG_READ_EXPAND_SUPPORTED
+   /* Expand paletted colors into true RGB triplets
+    * Expand grayscale images to full 8 bits from 1, 2, or 4 bits/pixel
+    * Expand paletted or RGB images with transparency to full alpha
+    * channels so the data will be available as RGBA quartets.
+    */
+   if (transforms & PNG_TRANSFORM_EXPAND)
+      if ((png_ptr->bit_depth < 8) ||
+          (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) ||
+          (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)))
+         png_set_expand(png_ptr);
+#endif
+   /* We don't handle background color or gamma transformation or quantizing.
+    */
+#ifdef PNG_READ_INVERT_SUPPORTED
+   /* Invert monochrome files to have 0 as white and 1 as black
+    */
+   if (transforms & PNG_TRANSFORM_INVERT_MONO)
+      png_set_invert_mono(png_ptr);
+#endif
+#ifdef PNG_READ_SHIFT_SUPPORTED
+   /* If you want to shift the pixel values from the range [0,255] or
+    * [0,65535] to the original [0,7] or [0,31], or whatever range the
+    * colors were originally in:
+    */
+   if ((transforms & PNG_TRANSFORM_SHIFT)
+       && png_get_valid(png_ptr, info_ptr, PNG_INFO_sBIT))
+   {
+      png_color_8p sig_bit;
+      png_get_sBIT(png_ptr, info_ptr, &sig_bit);
+      png_set_shift(png_ptr, sig_bit);
+   }
+#endif
+#ifdef PNG_READ_BGR_SUPPORTED
+   /* Flip the RGB pixels to BGR (or RGBA to BGRA) */
+   if (transforms & PNG_TRANSFORM_BGR)
+      png_set_bgr(png_ptr);
+#endif
+#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
+   /* Swap the RGBA or GA data to ARGB or AG (or BGRA to ABGR) */
+   if (transforms & PNG_TRANSFORM_SWAP_ALPHA)
+      png_set_swap_alpha(png_ptr);
+#endif
+#ifdef PNG_READ_SWAP_SUPPORTED
+   /* Swap bytes of 16-bit files to least significant byte first */
+   if (transforms & PNG_TRANSFORM_SWAP_ENDIAN)
+      png_set_swap(png_ptr);
+#endif
+/* Added at libpng-1.2.41 */
+#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
+   /* Invert the alpha channel from opacity to transparency */
+   if (transforms & PNG_TRANSFORM_INVERT_ALPHA)
+      png_set_invert_alpha(png_ptr);
+#endif
+/* Added at libpng-1.2.41 */
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+   /* Expand grayscale image to RGB */
+   if (transforms & PNG_TRANSFORM_GRAY_TO_RGB)
+      png_set_gray_to_rgb(png_ptr);
+#endif
+/* Added at libpng-1.5.4 */
+#ifdef PNG_READ_EXPAND_16_SUPPORTED
+   if (transforms & PNG_TRANSFORM_EXPAND_16)
+      png_set_expand_16(png_ptr);
+#endif
+   /* We don't handle adding filler bytes */
+   /* We use png_read_image and rely on that for interlace handling, but we also
+    * call png_read_update_info therefore must turn on interlace handling now:
+    */
+   (void)png_set_interlace_handling(png_ptr);
+   /* Optional call to gamma correct and add the background to the palette
+    * and update info structure.  REQUIRED if you are expecting libpng to
+    * update the palette for you (i.e., you selected such a transform above).
+    */
+   png_read_update_info(png_ptr, info_ptr);
+   /* -------------- image transformations end here ------------------- */
+   png_free_data(png_ptr, info_ptr, PNG_FREE_ROWS, 0);
+   if (info_ptr->row_pointers == NULL)
+   {
+      png_uint_32 iptr;
+      info_ptr->row_pointers = (png_bytepp)png_malloc(png_ptr,
+          info_ptr->height * png_sizeof(png_bytep));
+      for (iptr=0; iptr<info_ptr->height; iptr++)
+         info_ptr->row_pointers[iptr] = NULL;
+      info_ptr->free_me |= PNG_FREE_ROWS;
+      for (row = 0; row < (int)info_ptr->height; row++)
+         info_ptr->row_pointers[row] = (png_bytep)png_malloc(png_ptr,
+            png_get_rowbytes(png_ptr, info_ptr));
+   }
+   png_read_image(png_ptr, info_ptr->row_pointers);
+   info_ptr->valid |= PNG_INFO_IDAT;
+   /* Read rest of file, and get additional chunks in info_ptr - REQUIRED */
+   png_read_end(png_ptr, info_ptr);
+   PNG_UNUSED(transforms)   /* Quiet compiler warnings */
+   PNG_UNUSED(params)
+}
+#endif /* PNG_INFO_IMAGE_SUPPORTED */
+#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
+#endif /* PNG_READ_SUPPORTED */
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngrio.c b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngrio.c
new file mode 100644
index 0000000..d0d9d8a
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngrio.c
@@ -0,0 +1,176 @@
+/* pngrio.c - functions for data input
+ *
+ * Last changed in libpng 1.5.0 [January 6, 2011]
+ * Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * This file provides a location for all input.  Users who need
+ * special handling are expected to write a function that has the same
+ * arguments as this and performs a similar function, but that possibly
+ * has a different input method.  Note that you shouldn't change this
+ * function, but rather write a replacement function and then make
+ * libpng use it at run time with png_set_read_fn(...).
+ */
+#include "pngpriv.h"
+#ifdef PNG_READ_SUPPORTED
+/* Read the data from whatever input you are using.  The default routine
+ * reads from a file pointer.  Note that this routine sometimes gets called
+ * with very small lengths, so you should implement some kind of simple
+ * buffering if you are using unbuffered reads.  This should never be asked
+ * to read more then 64K on a 16 bit machine.
+ */
+void /* PRIVATE */
+png_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
+{
+   png_debug1(4, "reading %d bytes", (int)length);
+   if (png_ptr->read_data_fn != NULL)
+      (*(png_ptr->read_data_fn))(png_ptr, data, length);
+   else
+      png_error(png_ptr, "Call to NULL read function");
+}
+#ifdef PNG_STDIO_SUPPORTED
+/* This is the function that does the actual reading of data.  If you are
+ * not reading from a standard C stream, you should create a replacement
+ * read_data function and use it at run time with png_set_read_fn(), rather
+ * than changing the library.
+ */
+#  ifndef USE_FAR_KEYWORD
+void PNGCBAPI
+png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
+{
+   png_size_t check;
+   if (png_ptr == NULL)
+      return;
+   /* fread() returns 0 on error, so it is OK to store this in a png_size_t
+    * instead of an int, which is what fread() actually returns.
+    */
+   check = fread(data, 1, length, (png_FILE_p)png_ptr->io_ptr);
+   if (check != length)
+      png_error(png_ptr, "Read Error");
+}
+#  else
+/* This is the model-independent version. Since the standard I/O library
+   can't handle far buffers in the medium and small models, we have to copy
+   the data.
+*/
+#define NEAR_BUF_SIZE 1024
+#define MIN(a,b) (a <= b ? a : b)
+static void PNGCBAPI
+png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
+{
+   png_size_t check;
+   png_byte *n_data;
+   png_FILE_p io_ptr;
+   if (png_ptr == NULL)
+      return;
+   /* Check if data really is near. If so, use usual code. */
+   n_data = (png_byte *)CVT_PTR_NOCHECK(data);
+   io_ptr = (png_FILE_p)CVT_PTR(png_ptr->io_ptr);
+   if ((png_bytep)n_data == data)
+   {
+      check = fread(n_data, 1, length, io_ptr);
+   }
+   else
+   {
+      png_byte buf[NEAR_BUF_SIZE];
+      png_size_t read, remaining, err;
+      check = 0;
+      remaining = length;
+      do
+      {
+         read = MIN(NEAR_BUF_SIZE, remaining);
+         err = fread(buf, 1, read, io_ptr);
+         png_memcpy(data, buf, read); /* copy far buffer to near buffer */
+         if (err != read)
+            break;
+         else
+            check += err;
+         data += read;
+         remaining -= read;
+      }
+      while (remaining != 0);
+   }
+   if ((png_uint_32)check != (png_uint_32)length)
+      png_error(png_ptr, "read Error");
+}
+#  endif
+#endif
+/* This function allows the application to supply a new input function
+ * for libpng if standard C streams aren't being used.
+ *
+ * This function takes as its arguments:
+ *
+ * png_ptr      - pointer to a png input data structure
+ *
+ * io_ptr       - pointer to user supplied structure containing info about
+ *                the input functions.  May be NULL.
+ *
+ * read_data_fn - pointer to a new input function that takes as its
+ *                arguments a pointer to a png_struct, a pointer to
+ *                a location where input data can be stored, and a 32-bit
+ *                unsigned int that is the number of bytes to be read.
+ *                To exit and output any fatal error messages the new write
+ *                function should call png_error(png_ptr, "Error msg").
+ *                May be NULL, in which case libpng's default function will
+ *                be used.
+ */
+void PNGAPI
+png_set_read_fn(png_structp png_ptr, png_voidp io_ptr,
+   png_rw_ptr read_data_fn)
+{
+   if (png_ptr == NULL)
+      return;
+   png_ptr->io_ptr = io_ptr;
+#ifdef PNG_STDIO_SUPPORTED
+   if (read_data_fn != NULL)
+      png_ptr->read_data_fn = read_data_fn;
+   else
+      png_ptr->read_data_fn = png_default_read_data;
+#else
+   png_ptr->read_data_fn = read_data_fn;
+#endif
+   /* It is an error to write to a read device */
+   if (png_ptr->write_data_fn != NULL)
+   {
+      png_ptr->write_data_fn = NULL;
+      png_warning(png_ptr,
+          "Can't set both read_data_fn and write_data_fn in the"
+          " same structure");
+   }
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+   png_ptr->output_flush_fn = NULL;
+#endif
+}
+#endif /* PNG_READ_SUPPORTED */
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngrtran.c b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngrtran.c
new file mode 100644
index 0000000..26083a0
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngrtran.c
@@ -0,0 +1,5023 @@
+/* pngrtran.c - transforms the data in a row for PNG readers
+ *
+ * Last changed in libpng 1.5.7 [December 15, 2011]
+ * Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * This file contains functions optionally called by an application
+ * in order to tell libpng how to handle data when reading a PNG.
+ * Transformations that are used in both reading and writing are
+ * in pngtrans.c.
+ */
+#include "pngpriv.h"
+#ifdef PNG_READ_SUPPORTED
+/* Set the action on getting a CRC error for an ancillary or critical chunk. */
+void PNGAPI
+png_set_crc_action(png_structp png_ptr, int crit_action, int ancil_action)
+{
+   png_debug(1, "in png_set_crc_action");
+   if (png_ptr == NULL)
+      return;
+   /* Tell libpng how we react to CRC errors in critical chunks */
+   switch (crit_action)
+   {
+      case PNG_CRC_NO_CHANGE:                        /* Leave setting as is */
+         break;
+      case PNG_CRC_WARN_USE:                               /* Warn/use data */
+         png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK;
+         png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE;
+         break;
+      case PNG_CRC_QUIET_USE:                             /* Quiet/use data */
+         png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK;
+         png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE |
+                           PNG_FLAG_CRC_CRITICAL_IGNORE;
+         break;
+      case PNG_CRC_WARN_DISCARD:    /* Not a valid action for critical data */
+         png_warning(png_ptr,
+            "Can't discard critical data on CRC error");
+      case PNG_CRC_ERROR_QUIT:                                /* Error/quit */
+      case PNG_CRC_DEFAULT:
+      default:
+         png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK;
+         break;
+   }
+   /* Tell libpng how we react to CRC errors in ancillary chunks */
+   switch (ancil_action)
+   {
+      case PNG_CRC_NO_CHANGE:                       /* Leave setting as is */
+         break;
+      case PNG_CRC_WARN_USE:                              /* Warn/use data */
+         png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
+         png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE;
+         break;
+      case PNG_CRC_QUIET_USE:                            /* Quiet/use data */
+         png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
+         png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE |
+                           PNG_FLAG_CRC_ANCILLARY_NOWARN;
+         break;
+      case PNG_CRC_ERROR_QUIT:                               /* Error/quit */
+         png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
+         png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_NOWARN;
+         break;
+      case PNG_CRC_WARN_DISCARD:                      /* Warn/discard data */
+      case PNG_CRC_DEFAULT:
+      default:
+         png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
+         break;
+   }
+}
+#ifdef PNG_READ_BACKGROUND_SUPPORTED
+/* Handle alpha and tRNS via a background color */
+void PNGFAPI
+png_set_background_fixed(png_structp png_ptr,
+    png_const_color_16p background_color, int background_gamma_code,
+    int need_expand, png_fixed_point background_gamma)
+{
+   png_debug(1, "in png_set_background_fixed");
+   if (png_ptr == NULL)
+      return;
+   if (background_gamma_code == PNG_BACKGROUND_GAMMA_UNKNOWN)
+   {
+      png_warning(png_ptr, "Application must supply a known background gamma");
+      return;
+   }
+   png_ptr->transformations |= PNG_COMPOSE | PNG_STRIP_ALPHA;
+   png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
+   png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
+   png_memcpy(&(png_ptr->background), background_color,
+      png_sizeof(png_color_16));
+   png_ptr->background_gamma = background_gamma;
+   png_ptr->background_gamma_type = (png_byte)(background_gamma_code);
+   if (need_expand)
+      png_ptr->transformations |= PNG_BACKGROUND_EXPAND;
+   else
+      png_ptr->transformations &= ~PNG_BACKGROUND_EXPAND;
+}
+#  ifdef PNG_FLOATING_POINT_SUPPORTED
+void PNGAPI
+png_set_background(png_structp png_ptr,
+    png_const_color_16p background_color, int background_gamma_code,
+    int need_expand, double background_gamma)
+{
+   png_set_background_fixed(png_ptr, background_color, background_gamma_code,
+      need_expand, png_fixed(png_ptr, background_gamma, "png_set_background"));
+}
+#  endif  /* FLOATING_POINT */
+#endif /* READ_BACKGROUND */
+/* Scale 16-bit depth files to 8-bit depth.  If both of these are set then the
+ * one that pngrtran does first (scale) happens.  This is necessary to allow the
+ * TRANSFORM and API behavior to be somewhat consistent, and it's simpler.
+ */
+#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+void PNGAPI
+png_set_scale_16(png_structp png_ptr)
+{
+   png_debug(1, "in png_set_scale_16");
+   if (png_ptr == NULL)
+      return;
+   png_ptr->transformations |= PNG_SCALE_16_TO_8;
+}
+#endif
+#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
+/* Chop 16-bit depth files to 8-bit depth */
+void PNGAPI
+png_set_strip_16(png_structp png_ptr)
+{
+   png_debug(1, "in png_set_strip_16");
+   if (png_ptr == NULL)
+      return;
+   png_ptr->transformations |= PNG_16_TO_8;
+}
+#endif
+#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
+void PNGAPI
+png_set_strip_alpha(png_structp png_ptr)
+{
+   png_debug(1, "in png_set_strip_alpha");
+   if (png_ptr == NULL)
+      return;
+   png_ptr->transformations |= PNG_STRIP_ALPHA;
+}
+#endif
+#if defined(PNG_READ_ALPHA_MODE_SUPPORTED) || defined(PNG_READ_GAMMA_SUPPORTED)
+static png_fixed_point
+translate_gamma_flags(png_structp png_ptr, png_fixed_point output_gamma,
+   int is_screen)
+{
+   /* Check for flag values.  The main reason for having the old Mac value as a
+    * flag is that it is pretty near impossible to work out what the correct
+    * value is from Apple documentation - a working Mac system is needed to
+    * discover the value!
+    */
+   if (output_gamma == PNG_DEFAULT_sRGB ||
+      output_gamma == PNG_FP_1 / PNG_DEFAULT_sRGB)
+   {
+      /* If there is no sRGB support this just sets the gamma to the standard
+       * sRGB value.  (This is a side effect of using this function!)
+       */
+#     ifdef PNG_READ_sRGB_SUPPORTED
+         png_ptr->flags |= PNG_FLAG_ASSUME_sRGB;
+#     endif
+      if (is_screen)
+         output_gamma = PNG_GAMMA_sRGB;
+      else
+         output_gamma = PNG_GAMMA_sRGB_INVERSE;
+   }
+   else if (output_gamma == PNG_GAMMA_MAC_18 ||
+      output_gamma == PNG_FP_1 / PNG_GAMMA_MAC_18)
+   {
+      if (is_screen)
+         output_gamma = PNG_GAMMA_MAC_OLD;
+      else
+         output_gamma = PNG_GAMMA_MAC_INVERSE;
+   }
+   return output_gamma;
+}
+#  ifdef PNG_FLOATING_POINT_SUPPORTED
+static png_fixed_point
+convert_gamma_value(png_structp png_ptr, double output_gamma)
+{
+   /* The following silently ignores cases where fixed point (times 100,000)
+    * gamma values are passed to the floating point API.  This is safe and it
+    * means the fixed point constants work just fine with the floating point
+    * API.  The alternative would just lead to undetected errors and spurious
+    * bug reports.  Negative values fail inside the _fixed API unless they
+    * correspond to the flag values.
+    */
+   if (output_gamma > 0 && output_gamma < 128)
+      output_gamma *= PNG_FP_1;
+   /* This preserves -1 and -2 exactly: */
+   output_gamma = floor(output_gamma + .5);
+   if (output_gamma > PNG_FP_MAX || output_gamma < PNG_FP_MIN)
+      png_fixed_error(png_ptr, "gamma value");
+   return (png_fixed_point)output_gamma;
+}
+#  endif
+#endif /* READ_ALPHA_MODE || READ_GAMMA */
+#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+void PNGFAPI
+png_set_alpha_mode_fixed(png_structp png_ptr, int mode,
+   png_fixed_point output_gamma)
+{
+   int compose = 0;
+   png_fixed_point file_gamma;
+   png_debug(1, "in png_set_alpha_mode");
+   if (png_ptr == NULL)
+      return;
+   output_gamma = translate_gamma_flags(png_ptr, output_gamma, 1/*screen*/);
+   /* Validate the value to ensure it is in a reasonable range. The value
+    * is expected to be 1 or greater, but this range test allows for some
+    * viewing correction values.  The intent is to weed out users of this API
+    * who use the inverse of the gamma value accidentally!  Since some of these
+    * values are reasonable this may have to be changed.
+    */
+   if (output_gamma < 70000 || output_gamma > 300000)
+      png_error(png_ptr, "output gamma out of expected range");
+   /* The default file gamma is the inverse of the output gamma; the output
+    * gamma may be changed below so get the file value first:
+    */
+   file_gamma = png_reciprocal(output_gamma);
+   /* There are really 8 possibilities here, composed of any combination
+    * of:
+    *
+    *    premultiply the color channels
+    *    do not encode non-opaque pixels
+    *    encode the alpha as well as the color channels
+    *
+    * The differences disappear if the input/output ('screen') gamma is 1.0,
+    * because then the encoding is a no-op and there is only the choice of
+    * premultiplying the color channels or not.
+    *
+    * png_set_alpha_mode and png_set_background interact because both use
+    * png_compose to do the work.  Calling both is only useful when
+    * png_set_alpha_mode is used to set the default mode - PNG_ALPHA_PNG - along
+    * with a default gamma value.  Otherwise PNG_COMPOSE must not be set.
+    */
+   switch (mode)
+   {
+      case PNG_ALPHA_PNG:        /* default: png standard */
+         /* No compose, but it may be set by png_set_background! */
+         png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
+         png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
+         break;
+      case PNG_ALPHA_ASSOCIATED: /* color channels premultiplied */
+         compose = 1;
+         png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
+         png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
+         /* The output is linear: */
+         output_gamma = PNG_FP_1;
+         break;
+      case PNG_ALPHA_OPTIMIZED:  /* associated, non-opaque pixels linear */
+         compose = 1;
+         png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
+         png_ptr->flags |= PNG_FLAG_OPTIMIZE_ALPHA;
+         /* output_gamma records the encoding of opaque pixels! */
+         break;
+      case PNG_ALPHA_BROKEN:     /* associated, non-linear, alpha encoded */
+         compose = 1;
+         png_ptr->transformations |= PNG_ENCODE_ALPHA;
+         png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
+         break;
+      default:
+         png_error(png_ptr, "invalid alpha mode");
+   }
+   /* Only set the default gamma if the file gamma has not been set (this has
+    * the side effect that the gamma in a second call to png_set_alpha_mode will
+    * be ignored.)
+    */
+   if (png_ptr->gamma == 0)
+      png_ptr->gamma = file_gamma;
+   /* But always set the output gamma: */
+   png_ptr->screen_gamma = output_gamma;
+   /* Finally, if pre-multiplying, set the background fields to achieve the
+    * desired result.
+    */
+   if (compose)
+   {
+      /* And obtain alpha pre-multiplication by composing on black: */
+      png_memset(&png_ptr->background, 0, sizeof png_ptr->background);
+      png_ptr->background_gamma = png_ptr->gamma; /* just in case */
+      png_ptr->background_gamma_type = PNG_BACKGROUND_GAMMA_FILE;
+      png_ptr->transformations &= ~PNG_BACKGROUND_EXPAND;
+      if (png_ptr->transformations & PNG_COMPOSE)
+         png_error(png_ptr,
+            "conflicting calls to set alpha mode and background");
+      png_ptr->transformations |= PNG_COMPOSE;
+   }
+   /* New API, make sure apps call the correct initializers: */
+   png_ptr->flags |= PNG_FLAG_DETECT_UNINITIALIZED;
+}
+#  ifdef PNG_FLOATING_POINT_SUPPORTED
+void PNGAPI
+png_set_alpha_mode(png_structp png_ptr, int mode, double output_gamma)
+{
+   png_set_alpha_mode_fixed(png_ptr, mode, convert_gamma_value(png_ptr,
+      output_gamma));
+}
+#  endif
+#endif
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+/* Dither file to 8-bit.  Supply a palette, the current number
+ * of elements in the palette, the maximum number of elements
+ * allowed, and a histogram if possible.  If the current number
+ * of colors is greater then the maximum number, the palette will be
+ * modified to fit in the maximum number.  "full_quantize" indicates
+ * whether we need a quantizing cube set up for RGB images, or if we
+ * simply are reducing the number of colors in a paletted image.
+ */
+typedef struct png_dsort_struct
+{
+   struct png_dsort_struct FAR * next;
+   png_byte left;
+   png_byte right;
+} png_dsort;
+typedef png_dsort FAR *       png_dsortp;
+typedef png_dsort FAR * FAR * png_dsortpp;
+void PNGAPI
+png_set_quantize(png_structp png_ptr, png_colorp palette,
+    int num_palette, int maximum_colors, png_const_uint_16p histogram,
+    int full_quantize)
+{
+   png_debug(1, "in png_set_quantize");
+   if (png_ptr == NULL)
+      return;
+   png_ptr->transformations |= PNG_QUANTIZE;
+   if (!full_quantize)
+   {
+      int i;
+      png_ptr->quantize_index = (png_bytep)png_malloc(png_ptr,
+          (png_uint_32)(num_palette * png_sizeof(png_byte)));
+      for (i = 0; i < num_palette; i++)
+         png_ptr->quantize_index[i] = (png_byte)i;
+   }
+   if (num_palette > maximum_colors)
+   {
+      if (histogram != NULL)
+      {
+         /* This is easy enough, just throw out the least used colors.
+          * Perhaps not the best solution, but good enough.
+          */
+         int i;
+         /* Initialize an array to sort colors */
+         png_ptr->quantize_sort = (png_bytep)png_malloc(png_ptr,
+             (png_uint_32)(num_palette * png_sizeof(png_byte)));
+         /* Initialize the quantize_sort array */
+         for (i = 0; i < num_palette; i++)
+            png_ptr->quantize_sort[i] = (png_byte)i;
+         /* Find the least used palette entries by starting a
+          * bubble sort, and running it until we have sorted
+          * out enough colors.  Note that we don't care about
+          * sorting all the colors, just finding which are
+          * least used.
+          */
+         for (i = num_palette - 1; i >= maximum_colors; i--)
+         {
+            int done; /* To stop early if the list is pre-sorted */
+            int j;
+            done = 1;
+            for (j = 0; j < i; j++)
+            {
+               if (histogram[png_ptr->quantize_sort[j]]
+                   < histogram[png_ptr->quantize_sort[j + 1]])
+               {
+                  png_byte t;
+                  t = png_ptr->quantize_sort[j];
+                  png_ptr->quantize_sort[j] = png_ptr->quantize_sort[j + 1];
+                  png_ptr->quantize_sort[j + 1] = t;
+                  done = 0;
+               }
+            }
+            if (done)
+               break;
+         }
+         /* Swap the palette around, and set up a table, if necessary */
+         if (full_quantize)
+         {
+            int j = num_palette;
+            /* Put all the useful colors within the max, but don't
+             * move the others.
+             */
+            for (i = 0; i < maximum_colors; i++)
+            {
+               if ((int)png_ptr->quantize_sort[i] >= maximum_colors)
+               {
+                  do
+                     j--;
+                  while ((int)png_ptr->quantize_sort[j] >= maximum_colors);
+                  palette[i] = palette[j];
+               }
+            }
+         }
+         else
+         {
+            int j = num_palette;
+            /* Move all the used colors inside the max limit, and
+             * develop a translation table.
+             */
+            for (i = 0; i < maximum_colors; i++)
+            {
+               /* Only move the colors we need to */
+               if ((int)png_ptr->quantize_sort[i] >= maximum_colors)
+               {
+                  png_color tmp_color;
+                  do
+                     j--;
+                  while ((int)png_ptr->quantize_sort[j] >= maximum_colors);
+                  tmp_color = palette[j];
+                  palette[j] = palette[i];
+                  palette[i] = tmp_color;
+                  /* Indicate where the color went */
+                  png_ptr->quantize_index[j] = (png_byte)i;
+                  png_ptr->quantize_index[i] = (png_byte)j;
+               }
+            }
+            /* Find closest color for those colors we are not using */
+            for (i = 0; i < num_palette; i++)
+            {
+               if ((int)png_ptr->quantize_index[i] >= maximum_colors)
+               {
+                  int min_d, k, min_k, d_index;
+                  /* Find the closest color to one we threw out */
+                  d_index = png_ptr->quantize_index[i];
+                  min_d = PNG_COLOR_DIST(palette[d_index], palette[0]);
+                  for (k = 1, min_k = 0; k < maximum_colors; k++)
+                  {
+                     int d;
+                     d = PNG_COLOR_DIST(palette[d_index], palette[k]);
+                     if (d < min_d)
+                     {
+                        min_d = d;
+                        min_k = k;
+                     }
+                  }
+                  /* Point to closest color */
+                  png_ptr->quantize_index[i] = (png_byte)min_k;
+               }
+            }
+         }
+         png_free(png_ptr, png_ptr->quantize_sort);
+         png_ptr->quantize_sort = NULL;
+      }
+      else
+      {
+         /* This is much harder to do simply (and quickly).  Perhaps
+          * we need to go through a median cut routine, but those
+          * don't always behave themselves with only a few colors
+          * as input.  So we will just find the closest two colors,
+          * and throw out one of them (chosen somewhat randomly).
+          * [We don't understand this at all, so if someone wants to
+          *  work on improving it, be our guest - AED, GRP]
+          */
+         int i;
+         int max_d;
+         int num_new_palette;
+         png_dsortp t;
+         png_dsortpp hash;
+         t = NULL;
+         /* Initialize palette index arrays */
+         png_ptr->index_to_palette = (png_bytep)png_malloc(png_ptr,
+             (png_uint_32)(num_palette * png_sizeof(png_byte)));
+         png_ptr->palette_to_index = (png_bytep)png_malloc(png_ptr,
+             (png_uint_32)(num_palette * png_sizeof(png_byte)));
+         /* Initialize the sort array */
+         for (i = 0; i < num_palette; i++)
+         {
+            png_ptr->index_to_palette[i] = (png_byte)i;
+            png_ptr->palette_to_index[i] = (png_byte)i;
+         }
+         hash = (png_dsortpp)png_calloc(png_ptr, (png_uint_32)(769 *
+             png_sizeof(png_dsortp)));
+         num_new_palette = num_palette;
+         /* Initial wild guess at how far apart the farthest pixel
+          * pair we will be eliminating will be.  Larger
+          * numbers mean more areas will be allocated, Smaller
+          * numbers run the risk of not saving enough data, and
+          * having to do this all over again.
+          *
+          * I have not done extensive checking on this number.
+          */
+         max_d = 96;
+         while (num_new_palette > maximum_colors)
+         {
+            for (i = 0; i < num_new_palette - 1; i++)
+            {
+               int j;
+               for (j = i + 1; j < num_new_palette; j++)
+               {
+                  int d;
+                  d = PNG_COLOR_DIST(palette[i], palette[j]);
+                  if (d <= max_d)
+                  {
+                     t = (png_dsortp)png_malloc_warn(png_ptr,
+                         (png_uint_32)(png_sizeof(png_dsort)));
+                     if (t == NULL)
+                         break;
+                     t->next = hash[d];
+                     t->left = (png_byte)i;
+                     t->right = (png_byte)j;
+                     hash[d] = t;
+                  }
+               }
+               if (t == NULL)
+                  break;
+            }
+            if (t != NULL)
+            for (i = 0; i <= max_d; i++)
+            {
+               if (hash[i] != NULL)
+               {
+                  png_dsortp p;
+                  for (p = hash[i]; p; p = p->next)
+                  {
+                     if ((int)png_ptr->index_to_palette[p->left]
+                         < num_new_palette &&
+                         (int)png_ptr->index_to_palette[p->right]
+                         < num_new_palette)
+                     {
+                        int j, next_j;
+                        if (num_new_palette & 0x01)
+                        {
+                           j = p->left;
+                           next_j = p->right;
+                        }
+                        else
+                        {
+                           j = p->right;
+                           next_j = p->left;
+                        }
+                        num_new_palette--;
+                        palette[png_ptr->index_to_palette[j]]
+                            = palette[num_new_palette];
+                        if (!full_quantize)
+                        {
+                           int k;
+                           for (k = 0; k < num_palette; k++)
+                           {
+                              if (png_ptr->quantize_index[k] ==
+                                  png_ptr->index_to_palette[j])
+                                 png_ptr->quantize_index[k] =
+                                     png_ptr->index_to_palette[next_j];
+                              if ((int)png_ptr->quantize_index[k] ==
+                                  num_new_palette)
+                                 png_ptr->quantize_index[k] =
+                                     png_ptr->index_to_palette[j];
+                           }
+                        }
+                        png_ptr->index_to_palette[png_ptr->palette_to_index
+                            [num_new_palette]] = png_ptr->index_to_palette[j];
+                        png_ptr->palette_to_index[png_ptr->index_to_palette[j]]
+                            = png_ptr->palette_to_index[num_new_palette];
+                        png_ptr->index_to_palette[j] =
+                            (png_byte)num_new_palette;
+                        png_ptr->palette_to_index[num_new_palette] =
+                            (png_byte)j;
+                     }
+                     if (num_new_palette <= maximum_colors)
+                        break;
+                  }
+                  if (num_new_palette <= maximum_colors)
+                     break;
+               }
+            }
+            for (i = 0; i < 769; i++)
+            {
+               if (hash[i] != NULL)
+               {
+                  png_dsortp p = hash[i];
+                  while (p)
+                  {
+                     t = p->next;
+                     png_free(png_ptr, p);
+                     p = t;
+                  }
+               }
+               hash[i] = 0;
+            }
+            max_d += 96;
+         }
+         png_free(png_ptr, hash);
+         png_free(png_ptr, png_ptr->palette_to_index);
+         png_free(png_ptr, png_ptr->index_to_palette);
+         png_ptr->palette_to_index = NULL;
+         png_ptr->index_to_palette = NULL;
+      }
+      num_palette = maximum_colors;
+   }
+   if (png_ptr->palette == NULL)
+   {
+      png_ptr->palette = palette;
+   }
+   png_ptr->num_palette = (png_uint_16)num_palette;
+   if (full_quantize)
+   {
+      int i;
+      png_bytep distance;
+      int total_bits = PNG_QUANTIZE_RED_BITS + PNG_QUANTIZE_GREEN_BITS +
+          PNG_QUANTIZE_BLUE_BITS;
+      int num_red = (1 << PNG_QUANTIZE_RED_BITS);
+      int num_green = (1 << PNG_QUANTIZE_GREEN_BITS);
+      int num_blue = (1 << PNG_QUANTIZE_BLUE_BITS);
+      png_size_t num_entries = ((png_size_t)1 << total_bits);
+      png_ptr->palette_lookup = (png_bytep)png_calloc(png_ptr,
+          (png_uint_32)(num_entries * png_sizeof(png_byte)));
+      distance = (png_bytep)png_malloc(png_ptr, (png_uint_32)(num_entries *
+          png_sizeof(png_byte)));
+      png_memset(distance, 0xff, num_entries * png_sizeof(png_byte));
+      for (i = 0; i < num_palette; i++)
+      {
+         int ir, ig, ib;
+         int r = (palette[i].red >> (8 - PNG_QUANTIZE_RED_BITS));
+         int g = (palette[i].green >> (8 - PNG_QUANTIZE_GREEN_BITS));
+         int b = (palette[i].blue >> (8 - PNG_QUANTIZE_BLUE_BITS));
+         for (ir = 0; ir < num_red; ir++)
+         {
+            /* int dr = abs(ir - r); */
+            int dr = ((ir > r) ? ir - r : r - ir);
+            int index_r = (ir << (PNG_QUANTIZE_BLUE_BITS +
+                PNG_QUANTIZE_GREEN_BITS));
+            for (ig = 0; ig < num_green; ig++)
+            {
+               /* int dg = abs(ig - g); */
+               int dg = ((ig > g) ? ig - g : g - ig);
+               int dt = dr + dg;
+               int dm = ((dr > dg) ? dr : dg);
+               int index_g = index_r | (ig << PNG_QUANTIZE_BLUE_BITS);
+               for (ib = 0; ib < num_blue; ib++)
+               {
+                  int d_index = index_g | ib;
+                  /* int db = abs(ib - b); */
+                  int db = ((ib > b) ? ib - b : b - ib);
+                  int dmax = ((dm > db) ? dm : db);
+                  int d = dmax + dt + db;
+                  if (d < (int)distance[d_index])
+                  {
+                     distance[d_index] = (png_byte)d;
+                     png_ptr->palette_lookup[d_index] = (png_byte)i;
+                  }
+               }
+            }
+         }
+      }
+      png_free(png_ptr, distance);
+   }
+}
+#endif /* PNG_READ_QUANTIZE_SUPPORTED */
+#ifdef PNG_READ_GAMMA_SUPPORTED
+void PNGFAPI
+png_set_gamma_fixed(png_structp png_ptr, png_fixed_point scrn_gamma,
+   png_fixed_point file_gamma)
+{
+   png_debug(1, "in png_set_gamma_fixed");
+   if (png_ptr == NULL)
+      return;
+   /* New in libpng-1.5.4 - reserve particular negative values as flags. */
+   scrn_gamma = translate_gamma_flags(png_ptr, scrn_gamma, 1/*screen*/);
+   file_gamma = translate_gamma_flags(png_ptr, file_gamma, 0/*file*/);
+#if PNG_LIBPNG_VER >= 10600
+   /* Checking the gamma values for being >0 was added in 1.5.4 along with the
+    * premultiplied alpha support; this actually hides an undocumented feature
+    * of the previous implementation which allowed gamma processing to be
+    * disabled in background handling.  There is no evidence (so far) that this
+    * was being used; however, png_set_background itself accepted and must still
+    * accept '0' for the gamma value it takes, because it isn't always used.
+    *
+    * Since this is an API change (albeit a very minor one that removes an
+    * undocumented API feature) it will not be made until libpng-1.6.0.
+    */
+   if (file_gamma <= 0)
+      png_error(png_ptr, "invalid file gamma in png_set_gamma");
+   if (scrn_gamma <= 0)
+      png_error(png_ptr, "invalid screen gamma in png_set_gamma");
+#endif
+   /* Set the gamma values unconditionally - this overrides the value in the PNG
+    * file if a gAMA chunk was present.  png_set_alpha_mode provides a
+    * different, easier, way to default the file gamma.
+    */
+   png_ptr->gamma = file_gamma;
+   png_ptr->screen_gamma = scrn_gamma;
+}
+#  ifdef PNG_FLOATING_POINT_SUPPORTED
+void PNGAPI
+png_set_gamma(png_structp png_ptr, double scrn_gamma, double file_gamma)
+{
+   png_set_gamma_fixed(png_ptr, convert_gamma_value(png_ptr, scrn_gamma),
+      convert_gamma_value(png_ptr, file_gamma));
+}
+#  endif /* FLOATING_POINT_SUPPORTED */
+#endif /* READ_GAMMA */
+#ifdef PNG_READ_EXPAND_SUPPORTED
+/* Expand paletted images to RGB, expand grayscale images of
+ * less than 8-bit depth to 8-bit depth, and expand tRNS chunks
+ * to alpha channels.
+ */
+void PNGAPI
+png_set_expand(png_structp png_ptr)
+{
+   png_debug(1, "in png_set_expand");
+   if (png_ptr == NULL)
+      return;
+   png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
+   png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
+}
+/* GRR 19990627:  the following three functions currently are identical
+ *  to png_set_expand().  However, it is entirely reasonable that someone
+ *  might wish to expand an indexed image to RGB but *not* expand a single,
+ *  fully transparent palette entry to a full alpha channel--perhaps instead
+ *  convert tRNS to the grayscale/RGB format (16-bit RGB value), or replace
+ *  the transparent color with a particular RGB value, or drop tRNS entirely.
+ *  IOW, a future version of the library may make the transformations flag
+ *  a bit more fine-grained, with separate bits for each of these three
+ *  functions.
+ *
+ *  More to the point, these functions make it obvious what libpng will be
+ *  doing, whereas "expand" can (and does) mean any number of things.
+ *
+ *  GRP 20060307: In libpng-1.2.9, png_set_gray_1_2_4_to_8() was modified
+ *  to expand only the sample depth but not to expand the tRNS to alpha
+ *  and its name was changed to png_set_expand_gray_1_2_4_to_8().
+ */
+/* Expand paletted images to RGB. */
+void PNGAPI
+png_set_palette_to_rgb(png_structp png_ptr)
+{
+   png_debug(1, "in png_set_palette_to_rgb");
+   if (png_ptr == NULL)
+      return;
+   png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
+   png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
+}
+/* Expand grayscale images of less than 8-bit depth to 8 bits. */
+void PNGAPI
+png_set_expand_gray_1_2_4_to_8(png_structp png_ptr)
+{
+   png_debug(1, "in png_set_expand_gray_1_2_4_to_8");
+   if (png_ptr == NULL)
+      return;
+   png_ptr->transformations |= PNG_EXPAND;
+   png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
+}
+/* Expand tRNS chunks to alpha channels. */
+void PNGAPI
+png_set_tRNS_to_alpha(png_structp png_ptr)
+{
+   png_debug(1, "in png_set_tRNS_to_alpha");
+   png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
+   png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
+}
+#endif /* defined(PNG_READ_EXPAND_SUPPORTED) */
+#ifdef PNG_READ_EXPAND_16_SUPPORTED
+/* Expand to 16-bit channels, expand the tRNS chunk too (because otherwise
+ * it may not work correctly.)
+ */
+void PNGAPI
+png_set_expand_16(png_structp png_ptr)
+{
+   png_debug(1, "in png_set_expand_16");
+   if (png_ptr == NULL)
+      return;
+   png_ptr->transformations |= (PNG_EXPAND_16 | PNG_EXPAND | PNG_EXPAND_tRNS);
+   png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
+   /* New API, make sure apps call the correct initializers: */
+   png_ptr->flags |= PNG_FLAG_DETECT_UNINITIALIZED;
+}
+#endif
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+void PNGAPI
+png_set_gray_to_rgb(png_structp png_ptr)
+{
+   png_debug(1, "in png_set_gray_to_rgb");
+   if (png_ptr != NULL)
+   {
+      /* Because rgb must be 8 bits or more: */
+      png_set_expand_gray_1_2_4_to_8(png_ptr);
+      png_ptr->transformations |= PNG_GRAY_TO_RGB;
+      png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
+   }
+}
+#endif
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+void PNGFAPI
+png_set_rgb_to_gray_fixed(png_structp png_ptr, int error_action,
+    png_fixed_point red, png_fixed_point green)
+{
+   png_debug(1, "in png_set_rgb_to_gray");
+   if (png_ptr == NULL)
+      return;
+   switch(error_action)
+   {
+      case PNG_ERROR_ACTION_NONE:
+         png_ptr->transformations |= PNG_RGB_TO_GRAY;
+         break;
+      case PNG_ERROR_ACTION_WARN:
+         png_ptr->transformations |= PNG_RGB_TO_GRAY_WARN;
+         break;
+      case PNG_ERROR_ACTION_ERROR:
+         png_ptr->transformations |= PNG_RGB_TO_GRAY_ERR;
+         break;
+      default:
+         png_error(png_ptr, "invalid error action to rgb_to_gray");
+         break;
+   }
+   if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+#ifdef PNG_READ_EXPAND_SUPPORTED
+      png_ptr->transformations |= PNG_EXPAND;
+#else
+   {
+      png_warning(png_ptr,
+        "Cannot do RGB_TO_GRAY without EXPAND_SUPPORTED");
+      png_ptr->transformations &= ~PNG_RGB_TO_GRAY;
+   }
+#endif
+   {
+      if (red >= 0 && green >= 0 && red + green <= PNG_FP_1)
+      {
+         png_uint_16 red_int, green_int;
+         /* NOTE: this calculation does not round, but this behavior is retained
+          * for consistency, the inaccuracy is very small.  The code here always
+          * overwrites the coefficients, regardless of whether they have been
+          * defaulted or set already.
+          */
+         red_int = (png_uint_16)(((png_uint_32)red*32768)/100000);
+         green_int = (png_uint_16)(((png_uint_32)green*32768)/100000);
+         png_ptr->rgb_to_gray_red_coeff   = red_int;
+         png_ptr->rgb_to_gray_green_coeff = green_int;
+         png_ptr->rgb_to_gray_coefficients_set = 1;
+      }
+      else
+      {
+         if (red >= 0 && green >= 0)
+            png_warning(png_ptr,
+               "ignoring out of range rgb_to_gray coefficients");
+         /* Use the defaults, from the cHRM chunk if set, else the historical
+          * values which are close to the sRGB/HDTV/ITU-Rec 709 values.  See
+          * png_do_rgb_to_gray for more discussion of the values.  In this case
+          * the coefficients are not marked as 'set' and are not overwritten if
+          * something has already provided a default.
+          */
+         if (png_ptr->rgb_to_gray_red_coeff == 0 &&
+            png_ptr->rgb_to_gray_green_coeff == 0)
+         {
+            png_ptr->rgb_to_gray_red_coeff   = 6968;
+            png_ptr->rgb_to_gray_green_coeff = 23434;
+            /* png_ptr->rgb_to_gray_blue_coeff  = 2366; */
+         }
+      }
+   }
+}
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+/* Convert a RGB image to a grayscale of the same width.  This allows us,
+ * for example, to convert a 24 bpp RGB image into an 8 bpp grayscale image.
+ */
+void PNGAPI
+png_set_rgb_to_gray(png_structp png_ptr, int error_action, double red,
+   double green)
+{
+   if (png_ptr == NULL)
+      return;
+   png_set_rgb_to_gray_fixed(png_ptr, error_action,
+      png_fixed(png_ptr, red, "rgb to gray red coefficient"),
+      png_fixed(png_ptr, green, "rgb to gray green coefficient"));
+}
+#endif /* FLOATING POINT */
+#endif
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
+    defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
+void PNGAPI
+png_set_read_user_transform_fn(png_structp png_ptr, png_user_transform_ptr
+    read_user_transform_fn)
+{
+   png_debug(1, "in png_set_read_user_transform_fn");
+   if (png_ptr == NULL)
+      return;
+#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
+   png_ptr->transformations |= PNG_USER_TRANSFORM;
+   png_ptr->read_user_transform_fn = read_user_transform_fn;
+#endif
+}
+#endif
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+#ifdef PNG_READ_GAMMA_SUPPORTED
+/* In the case of gamma transformations only do transformations on images where
+ * the [file] gamma and screen_gamma are not close reciprocals, otherwise it
+ * slows things down slightly, and also needlessly introduces small errors.
+ */
+static int /* PRIVATE */
+png_gamma_threshold(png_fixed_point screen_gamma, png_fixed_point file_gamma)
+{
+   /* PNG_GAMMA_THRESHOLD is the threshold for performing gamma
+    * correction as a difference of the overall transform from 1.0
+    *
+    * We want to compare the threshold with s*f - 1, if we get
+    * overflow here it is because of wacky gamma values so we
+    * turn on processing anyway.
+    */
+   png_fixed_point gtest;
+   return !png_muldiv(&gtest, screen_gamma, file_gamma, PNG_FP_1) ||
+       png_gamma_significant(gtest);
+}
+#endif
+/* Initialize everything needed for the read.  This includes modifying
+ * the palette.
+ */
+/*For the moment 'png_init_palette_transformations' and
+ * 'png_init_rgb_transformations' only do some flag canceling optimizations.
+ * The intent is that these two routines should have palette or rgb operations
+ * extracted from 'png_init_read_transformations'.
+ */
+static void /* PRIVATE */
+png_init_palette_transformations(png_structp png_ptr)
+{
+   /* Called to handle the (input) palette case.  In png_do_read_transformations
+    * the first step is to expand the palette if requested, so this code must
+    * take care to only make changes that are invariant with respect to the
+    * palette expansion, or only do them if there is no expansion.
+    *
+    * STRIP_ALPHA has already been handled in the caller (by setting num_trans
+    * to 0.)
+    */
+   int input_has_alpha = 0;
+   int input_has_transparency = 0;
+   if (png_ptr->num_trans > 0)
+   {
+      int i;
+      /* Ignore if all the entries are opaque (unlikely!) */
+      for (i=0; i<png_ptr->num_trans; ++i)
+         if (png_ptr->trans_alpha[i] == 255)
+            continue;
+         else if (png_ptr->trans_alpha[i] == 0)
+            input_has_transparency = 1;
+         else
+            input_has_alpha = 1;
+   }
+   /* If no alpha we can optimize. */
+   if (!input_has_alpha)
+   {
+      /* Any alpha means background and associative alpha processing is
+       * required, however if the alpha is 0 or 1 throughout OPTIIMIZE_ALPHA
+       * and ENCODE_ALPHA are irrelevant.
+       */
+      png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
+      png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
+      if (!input_has_transparency)
+         png_ptr->transformations &= ~(PNG_COMPOSE | PNG_BACKGROUND_EXPAND);
+   }
+#if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED)
+   /* png_set_background handling - deals with the complexity of whether the
+    * background color is in the file format or the screen format in the case
+    * where an 'expand' will happen.
+    */
+   /* The following code cannot be entered in the alpha pre-multiplication case
+    * because PNG_BACKGROUND_EXPAND is cancelled below.
+    */
+   if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) &&
+       (png_ptr->transformations & PNG_EXPAND))
+   {
+      {
+         png_ptr->background.red   =
+             png_ptr->palette[png_ptr->background.index].red;
+         png_ptr->background.green =
+             png_ptr->palette[png_ptr->background.index].green;
+         png_ptr->background.blue  =
+             png_ptr->palette[png_ptr->background.index].blue;
+#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
+        if (png_ptr->transformations & PNG_INVERT_ALPHA)
+        {
+           if (!(png_ptr->transformations & PNG_EXPAND_tRNS))
+           {
+              /* Invert the alpha channel (in tRNS) unless the pixels are
+               * going to be expanded, in which case leave it for later
+               */
+              int i, istop = png_ptr->num_trans;
+              for (i=0; i<istop; i++)
+                 png_ptr->trans_alpha[i] = (png_byte)(255 -
+                    png_ptr->trans_alpha[i]);
+           }
+        }
+#endif /* PNG_READ_INVERT_ALPHA_SUPPORTED */
+      }
+   } /* background expand and (therefore) no alpha association. */
+#endif /* PNG_READ_EXPAND_SUPPORTED && PNG_READ_BACKGROUND_SUPPORTED */
+}
+static void /* PRIVATE */
+png_init_rgb_transformations(png_structp png_ptr)
+{
+   /* Added to libpng-1.5.4: check the color type to determine whether there
+    * is any alpha or transparency in the image and simply cancel the
+    * background and alpha mode stuff if there isn't.
+    */
+   int input_has_alpha = (png_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0;
+   int input_has_transparency = png_ptr->num_trans > 0;
+   /* If no alpha we can optimize. */
+   if (!input_has_alpha)
+   {
+      /* Any alpha means background and associative alpha processing is
+       * required, however if the alpha is 0 or 1 throughout OPTIIMIZE_ALPHA
+       * and ENCODE_ALPHA are irrelevant.
+       */
+#     ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+         png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
+         png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
+#     endif
+      if (!input_has_transparency)
+         png_ptr->transformations &= ~(PNG_COMPOSE | PNG_BACKGROUND_EXPAND);
+   }
+#if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED)
+   /* png_set_background handling - deals with the complexity of whether the
+    * background color is in the file format or the screen format in the case
+    * where an 'expand' will happen.
+    */
+   /* The following code cannot be entered in the alpha pre-multiplication case
+    * because PNG_BACKGROUND_EXPAND is cancelled below.
+    */
+   if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) &&
+       (png_ptr->transformations & PNG_EXPAND) &&
+       !(png_ptr->color_type & PNG_COLOR_MASK_COLOR))
+       /* i.e., GRAY or GRAY_ALPHA */
+   {
+      {
+         /* Expand background and tRNS chunks */
+         int gray = png_ptr->background.gray;
+         int trans_gray = png_ptr->trans_color.gray;
+         switch (png_ptr->bit_depth)
+         {
+            case 1:
+               gray *= 0xff;
+               trans_gray *= 0xff;
+               break;
+            case 2:
+               gray *= 0x55;
+               trans_gray *= 0x55;
+               break;
+            case 4:
+               gray *= 0x11;
+               trans_gray *= 0x11;
+               break;
+            default:
+            case 8:
+               /* Already 8 bits, fall through */
+            case 16:
+               /* Already a full 16 bits */
+               break;
+         }
+         png_ptr->background.red = png_ptr->background.green =
+            png_ptr->background.blue = (png_uint_16)gray;
+         if (!(png_ptr->transformations & PNG_EXPAND_tRNS))
+         {
+            png_ptr->trans_color.red = png_ptr->trans_color.green =
+               png_ptr->trans_color.blue = (png_uint_16)trans_gray;
+         }
+      }
+   } /* background expand and (therefore) no alpha association. */
+#endif /* PNG_READ_EXPAND_SUPPORTED && PNG_READ_BACKGROUND_SUPPORTED */
+}
+void /* PRIVATE */
+png_init_read_transformations(png_structp png_ptr)
+{
+   png_debug(1, "in png_init_read_transformations");
+   /* This internal function is called from png_read_start_row in pngrutil.c
+    * and it is called before the 'rowbytes' calculation is done, so the code
+    * in here can change or update the transformations flags.
+    *
+    * First do updates that do not depend on the details of the PNG image data
+    * being processed.
+    */
+#ifdef PNG_READ_GAMMA_SUPPORTED
+   /* Prior to 1.5.4 these tests were performed from png_set_gamma, 1.5.4 adds
+    * png_set_alpha_mode and this is another source for a default file gamma so
+    * the test needs to be performed later - here.  In addition prior to 1.5.4
+    * the tests were repeated for the PALETTE color type here - this is no
+    * longer necessary (and doesn't seem to have been necessary before.)
+    */
+   {
+      /* The following temporary indicates if overall gamma correction is
+       * required.
+       */
+      int gamma_correction = 0;
+      if (png_ptr->gamma != 0) /* has been set */
+      {
+         if (png_ptr->screen_gamma != 0) /* screen set too */
+            gamma_correction = png_gamma_threshold(png_ptr->gamma,
+               png_ptr->screen_gamma);
+         else
+            /* Assume the output matches the input; a long time default behavior
+             * of libpng, although the standard has nothing to say about this.
+             */
+            png_ptr->screen_gamma = png_reciprocal(png_ptr->gamma);
+      }
+      else if (png_ptr->screen_gamma != 0)
+         /* The converse - assume the file matches the screen, note that this
+          * perhaps undesireable default can (from 1.5.4) be changed by calling
+          * png_set_alpha_mode (even if the alpha handling mode isn't required
+          * or isn't changed from the default.)
+          */
+         png_ptr->gamma = png_reciprocal(png_ptr->screen_gamma);
+      else /* neither are set */
+         /* Just in case the following prevents any processing - file and screen
+          * are both assumed to be linear and there is no way to introduce a
+          * third gamma value other than png_set_background with 'UNIQUE', and,
+          * prior to 1.5.4
+          */
+         png_ptr->screen_gamma = png_ptr->gamma = PNG_FP_1;
+      /* Now turn the gamma transformation on or off as appropriate.  Notice
+       * that PNG_GAMMA just refers to the file->screen correction.  Alpha
+       * composition may independently cause gamma correction because it needs
+       * linear data (e.g. if the file has a gAMA chunk but the screen gamma
+       * hasn't been specified.)  In any case this flag may get turned off in
+       * the code immediately below if the transform can be handled outside the
+       * row loop.
+       */
+      if (gamma_correction)
+         png_ptr->transformations |= PNG_GAMMA;
+      else
+         png_ptr->transformations &= ~PNG_GAMMA;
+   }
+#endif
+   /* Certain transformations have the effect of preventing other
+    * transformations that happen afterward in png_do_read_transformations,
+    * resolve the interdependencies here.  From the code of
+    * png_do_read_transformations the order is:
+    *
+    *  1) PNG_EXPAND (including PNG_EXPAND_tRNS)
+    *  2) PNG_STRIP_ALPHA (if no compose)
+    *  3) PNG_RGB_TO_GRAY
+    *  4) PNG_GRAY_TO_RGB iff !PNG_BACKGROUND_IS_GRAY
+    *  5) PNG_COMPOSE
+    *  6) PNG_GAMMA
+    *  7) PNG_STRIP_ALPHA (if compose)
+    *  8) PNG_ENCODE_ALPHA
+    *  9) PNG_SCALE_16_TO_8
+    * 10) PNG_16_TO_8
+    * 11) PNG_QUANTIZE (converts to palette)
+    * 12) PNG_EXPAND_16
+    * 13) PNG_GRAY_TO_RGB iff PNG_BACKGROUND_IS_GRAY
+    * 14) PNG_INVERT_MONO
+    * 15) PNG_SHIFT
+    * 16) PNG_PACK
+    * 17) PNG_BGR
+    * 18) PNG_PACKSWAP
+    * 19) PNG_FILLER (includes PNG_ADD_ALPHA)
+    * 20) PNG_INVERT_ALPHA
+    * 21) PNG_SWAP_ALPHA
+    * 22) PNG_SWAP_BYTES
+    * 23) PNG_USER_TRANSFORM [must be last]
+    */
+#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
+   if ((png_ptr->transformations & PNG_STRIP_ALPHA) &&
+      !(png_ptr->transformations & PNG_COMPOSE))
+   {
+      /* Stripping the alpha channel happens immediately after the 'expand'
+       * transformations, before all other transformation, so it cancels out
+       * the alpha handling.  It has the side effect negating the effect of
+       * PNG_EXPAND_tRNS too:
+       */
+      png_ptr->transformations &= ~(PNG_BACKGROUND_EXPAND | PNG_ENCODE_ALPHA |
+         PNG_EXPAND_tRNS);
+      png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
+      /* Kill the tRNS chunk itself too.  Prior to 1.5.4 this did not happen
+       * so transparency information would remain just so long as it wasn't
+       * expanded.  This produces unexpected API changes if the set of things
+       * that do PNG_EXPAND_tRNS changes (perfectly possible given the
+       * documentation - which says ask for what you want, accept what you
+       * get.)  This makes the behavior consistent from 1.5.4:
+       */
+      png_ptr->num_trans = 0;
+   }
+#endif /* STRIP_ALPHA supported, no COMPOSE */
+#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+   /* If the screen gamma is about 1.0 then the OPTIMIZE_ALPHA and ENCODE_ALPHA
+    * settings will have no effect.
+    */
+   if (!png_gamma_significant(png_ptr->screen_gamma))
+   {
+      png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
+      png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
+   }
+#endif
+#if defined(PNG_READ_EXPAND_SUPPORTED) && \
+   defined(PNG_READ_BACKGROUND_SUPPORTED) && \
+   defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
+   /* Detect gray background and attempt to enable optimization for
+    * gray --> RGB case.
+    *
+    * Note:  if PNG_BACKGROUND_EXPAND is set and color_type is either RGB or
+    * RGB_ALPHA (in which case need_expand is superfluous anyway), the
+    * background color might actually be gray yet not be flagged as such.
+    * This is not a problem for the current code, which uses
+    * PNG_BACKGROUND_IS_GRAY only to decide when to do the
+    * png_do_gray_to_rgb() transformation.
+    *
+    * TODO: this code needs to be revised to avoid the complexity and
+    * interdependencies.  The color type of the background should be recorded in
+    * png_set_background, along with the bit depth, then the code has a record
+    * of exactly what color space the background is currently in.
+    */
+   if (png_ptr->transformations & PNG_BACKGROUND_EXPAND)
+   {
+      /* PNG_BACKGROUND_EXPAND: the background is in the file color space, so if
+       * the file was grayscale the background value is gray.
+       */
+      if (!(png_ptr->color_type & PNG_COLOR_MASK_COLOR))
+         png_ptr->mode |= PNG_BACKGROUND_IS_GRAY;
+   }
+   else if (png_ptr->transformations & PNG_COMPOSE)
+   {
+      /* PNG_COMPOSE: png_set_background was called with need_expand false,
+       * so the color is in the color space of the output or png_set_alpha_mode
+       * was called and the color is black.  Ignore RGB_TO_GRAY because that
+       * happens before GRAY_TO_RGB.
+       */
+      if (png_ptr->transformations & PNG_GRAY_TO_RGB)
+      {
+         if (png_ptr->background.red == png_ptr->background.green &&
+             png_ptr->background.red == png_ptr->background.blue)
+         {
+            png_ptr->mode |= PNG_BACKGROUND_IS_GRAY;
+            png_ptr->background.gray = png_ptr->background.red;
+         }
+      }
+   }
+#endif /* PNG_READ_GRAY_TO_RGB_SUPPORTED (etc) */
+   /* For indexed PNG data (PNG_COLOR_TYPE_PALETTE) many of the transformations
+    * can be performed directly on the palette, and some (such as rgb to gray)
+    * can be optimized inside the palette.  This is particularly true of the
+    * composite (background and alpha) stuff, which can be pretty much all done
+    * in the palette even if the result is expanded to RGB or gray afterward.
+    *
+    * NOTE: this is Not Yet Implemented, the code behaves as in 1.5.1 and
+    * earlier and the palette stuff is actually handled on the first row.  This
+    * leads to the reported bug that the palette returned by png_get_PLTE is not
+    * updated.
+    */
+   if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+      png_init_palette_transformations(png_ptr);
+   else
+      png_init_rgb_transformations(png_ptr);
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) && \
+   defined(PNG_READ_EXPAND_16_SUPPORTED)
+   if ((png_ptr->transformations & PNG_EXPAND_16) &&
+      (png_ptr->transformations & PNG_COMPOSE) &&
+      !(png_ptr->transformations & PNG_BACKGROUND_EXPAND) &&
+      png_ptr->bit_depth != 16)
+   {
+      /* TODO: fix this.  Because the expand_16 operation is after the compose
+       * handling the background color must be 8, not 16, bits deep, but the
+       * application will supply a 16-bit value so reduce it here.
+       *
+       * The PNG_BACKGROUND_EXPAND code above does not expand to 16 bits at
+       * present, so that case is ok (until do_expand_16 is moved.)
+       *
+       * NOTE: this discards the low 16 bits of the user supplied background
+       * color, but until expand_16 works properly there is no choice!
+       */
+#     define CHOP(x) (x)=((png_uint_16)(((png_uint_32)(x)*255+32895) >> 16))
+      CHOP(png_ptr->background.red);
+      CHOP(png_ptr->background.green);
+      CHOP(png_ptr->background.blue);
+      CHOP(png_ptr->background.gray);
+#     undef CHOP
+   }
+#endif /* PNG_READ_BACKGROUND_SUPPORTED && PNG_READ_EXPAND_16_SUPPORTED */
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) && \
+   (defined(PNG_READ_SCALE_16_TO_8_SUPPORTED) || \
+   defined(PNG_READ_STRIP_16_TO_8_SUPPORTED))
+   if ((png_ptr->transformations & (PNG_16_TO_8|PNG_SCALE_16_TO_8)) &&
+      (png_ptr->transformations & PNG_COMPOSE) &&
+      !(png_ptr->transformations & PNG_BACKGROUND_EXPAND) &&
+      png_ptr->bit_depth == 16)
+   {
+      /* On the other hand, if a 16-bit file is to be reduced to 8-bits per
+       * component this will also happen after PNG_COMPOSE and so the background
+       * color must be pre-expanded here.
+       *
+       * TODO: fix this too.
+       */
+      png_ptr->background.red = (png_uint_16)(png_ptr->background.red * 257);
+      png_ptr->background.green =
+         (png_uint_16)(png_ptr->background.green * 257);
+      png_ptr->background.blue = (png_uint_16)(png_ptr->background.blue * 257);
+      png_ptr->background.gray = (png_uint_16)(png_ptr->background.gray * 257);
+   }
+#endif
+   /* NOTE: below 'PNG_READ_ALPHA_MODE_SUPPORTED' is presumed to also enable the
+    * background support (see the comments in scripts/pnglibconf.dfa), this
+    * allows pre-multiplication of the alpha channel to be implemented as
+    * compositing on black.  This is probably sub-optimal and has been done in
+    * 1.5.4 betas simply to enable external critique and testing (i.e. to
+    * implement the new API quickly, without lots of internal changes.)
+    */
+#ifdef PNG_READ_GAMMA_SUPPORTED
+#  ifdef PNG_READ_BACKGROUND_SUPPORTED
+      /* Includes ALPHA_MODE */
+      png_ptr->background_1 = png_ptr->background;
+#  endif
+   /* This needs to change - in the palette image case a whole set of tables are
+    * built when it would be quicker to just calculate the correct value for
+    * each palette entry directly.  Also, the test is too tricky - why check
+    * PNG_RGB_TO_GRAY if PNG_GAMMA is not set?  The answer seems to be that
+    * PNG_GAMMA is cancelled even if the gamma is known?  The test excludes the
+    * PNG_COMPOSE case, so apparently if there is no *overall* gamma correction
+    * the gamma tables will not be built even if composition is required on a
+    * gamma encoded value.
+    *
+    * In 1.5.4 this is addressed below by an additional check on the individual
+    * file gamma - if it is not 1.0 both RGB_TO_GRAY and COMPOSE need the
+    * tables.
+    */
+   if ((png_ptr->transformations & PNG_GAMMA)
+      || ((png_ptr->transformations & PNG_RGB_TO_GRAY)
+         && (png_gamma_significant(png_ptr->gamma) ||
+            png_gamma_significant(png_ptr->screen_gamma)))
+      || ((png_ptr->transformations & PNG_COMPOSE)
+         && (png_gamma_significant(png_ptr->gamma)
+            || png_gamma_significant(png_ptr->screen_gamma)
+#  ifdef PNG_READ_BACKGROUND_SUPPORTED
+            || (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_UNIQUE
+               && png_gamma_significant(png_ptr->background_gamma))
+#  endif
+      )) || ((png_ptr->transformations & PNG_ENCODE_ALPHA)
+         && png_gamma_significant(png_ptr->screen_gamma))
+      )
+   {
+      png_build_gamma_table(png_ptr, png_ptr->bit_depth);
+#ifdef PNG_READ_BACKGROUND_SUPPORTED
+      if (png_ptr->transformations & PNG_COMPOSE)
+      {
+         /* Issue a warning about this combination: because RGB_TO_GRAY is
+          * optimized to do the gamma transform if present yet do_background has
+          * to do the same thing if both options are set a
+          * double-gamma-correction happens.  This is true in all versions of
+          * libpng to date.
+          */
+         if (png_ptr->transformations & PNG_RGB_TO_GRAY)
+            png_warning(png_ptr,
+               "libpng does not support gamma+background+rgb_to_gray");
+         if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+         {
+            /* We don't get to here unless there is a tRNS chunk with non-opaque
+             * entries - see the checking code at the start of this function.
+             */
+            png_color back, back_1;
+            png_colorp palette = png_ptr->palette;
+            int num_palette = png_ptr->num_palette;
+            int i;
+            if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_FILE)
+            {
+               back.red = png_ptr->gamma_table[png_ptr->background.red];
+               back.green = png_ptr->gamma_table[png_ptr->background.green];
+               back.blue = png_ptr->gamma_table[png_ptr->background.blue];
+               back_1.red = png_ptr->gamma_to_1[png_ptr->background.red];
+               back_1.green = png_ptr->gamma_to_1[png_ptr->background.green];
+               back_1.blue = png_ptr->gamma_to_1[png_ptr->background.blue];
+            }
+            else
+            {
+               png_fixed_point g, gs;
+               switch (png_ptr->background_gamma_type)
+               {
+                  case PNG_BACKGROUND_GAMMA_SCREEN:
+                     g = (png_ptr->screen_gamma);
+                     gs = PNG_FP_1;
+                     break;
+                  case PNG_BACKGROUND_GAMMA_FILE:
+                     g = png_reciprocal(png_ptr->gamma);
+                     gs = png_reciprocal2(png_ptr->gamma,
+                        png_ptr->screen_gamma);
+                     break;
+                  case PNG_BACKGROUND_GAMMA_UNIQUE:
+                     g = png_reciprocal(png_ptr->background_gamma);
+                     gs = png_reciprocal2(png_ptr->background_gamma,
+                        png_ptr->screen_gamma);
+                     break;
+                  default:
+                     g = PNG_FP_1;    /* back_1 */
+                     gs = PNG_FP_1;   /* back */
+                     break;
+               }
+               if (png_gamma_significant(gs))
+               {
+                  back.red = png_gamma_8bit_correct(png_ptr->background.red,
+                      gs);
+                  back.green = png_gamma_8bit_correct(png_ptr->background.green,
+                      gs);
+                  back.blue = png_gamma_8bit_correct(png_ptr->background.blue,
+                      gs);
+               }
+               else
+               {
+                  back.red   = (png_byte)png_ptr->background.red;
+                  back.green = (png_byte)png_ptr->background.green;
+                  back.blue  = (png_byte)png_ptr->background.blue;
+               }
+               if (png_gamma_significant(g))
+               {
+                  back_1.red = png_gamma_8bit_correct(png_ptr->background.red,
+                     g);
+                  back_1.green = png_gamma_8bit_correct(
+                     png_ptr->background.green, g);
+                  back_1.blue = png_gamma_8bit_correct(png_ptr->background.blue,
+                     g);
+               }
+               else
+               {
+                  back_1.red   = (png_byte)png_ptr->background.red;
+                  back_1.green = (png_byte)png_ptr->background.green;
+                  back_1.blue  = (png_byte)png_ptr->background.blue;
+               }
+            }
+            for (i = 0; i < num_palette; i++)
+            {
+               if (i < (int)png_ptr->num_trans &&
+                   png_ptr->trans_alpha[i] != 0xff)
+               {
+                  if (png_ptr->trans_alpha[i] == 0)
+                  {
+                     palette[i] = back;
+                  }
+                  else /* if (png_ptr->trans_alpha[i] != 0xff) */
+                  {
+                     png_byte v, w;
+                     v = png_ptr->gamma_to_1[palette[i].red];
+                     png_composite(w, v, png_ptr->trans_alpha[i], back_1.red);
+                     palette[i].red = png_ptr->gamma_from_1[w];
+                     v = png_ptr->gamma_to_1[palette[i].green];
+                     png_composite(w, v, png_ptr->trans_alpha[i], back_1.green);
+                     palette[i].green = png_ptr->gamma_from_1[w];
+                     v = png_ptr->gamma_to_1[palette[i].blue];
+                     png_composite(w, v, png_ptr->trans_alpha[i], back_1.blue);
+                     palette[i].blue = png_ptr->gamma_from_1[w];
+                  }
+               }
+               else
+               {
+                  palette[i].red = png_ptr->gamma_table[palette[i].red];
+                  palette[i].green = png_ptr->gamma_table[palette[i].green];
+                  palette[i].blue = png_ptr->gamma_table[palette[i].blue];
+               }
+            }
+            /* Prevent the transformations being done again.
+             *
+             * NOTE: this is highly dubious; it removes the transformations in
+             * place.  This seems inconsistent with the general treatment of the
+             * transformations elsewhere.
+             */
+            png_ptr->transformations &= ~(PNG_COMPOSE | PNG_GAMMA);
+         } /* color_type == PNG_COLOR_TYPE_PALETTE */
+         /* if (png_ptr->background_gamma_type!=PNG_BACKGROUND_GAMMA_UNKNOWN) */
+         else /* color_type != PNG_COLOR_TYPE_PALETTE */
+         {
+            int gs_sig, g_sig;
+            png_fixed_point g = PNG_FP_1;  /* Correction to linear */
+            png_fixed_point gs = PNG_FP_1; /* Correction to screen */
+            switch (png_ptr->background_gamma_type)
+            {
+               case PNG_BACKGROUND_GAMMA_SCREEN:
+                  g = png_ptr->screen_gamma;
+                  /* gs = PNG_FP_1; */
+                  break;
+               case PNG_BACKGROUND_GAMMA_FILE:
+                  g = png_reciprocal(png_ptr->gamma);
+                  gs = png_reciprocal2(png_ptr->gamma, png_ptr->screen_gamma);
+                  break;
+               case PNG_BACKGROUND_GAMMA_UNIQUE:
+                  g = png_reciprocal(png_ptr->background_gamma);
+                  gs = png_reciprocal2(png_ptr->background_gamma,
+                      png_ptr->screen_gamma);
+                  break;
+               default:
+                  png_error(png_ptr, "invalid background gamma type");
+            }
+            g_sig = png_gamma_significant(g);
+            gs_sig = png_gamma_significant(gs);
+            if (g_sig)
+               png_ptr->background_1.gray = png_gamma_correct(png_ptr,
+                   png_ptr->background.gray, g);
+            if (gs_sig)
+               png_ptr->background.gray = png_gamma_correct(png_ptr,
+                   png_ptr->background.gray, gs);
+            if ((png_ptr->background.red != png_ptr->background.green) ||
+                (png_ptr->background.red != png_ptr->background.blue) ||
+                (png_ptr->background.red != png_ptr->background.gray))
+            {
+               /* RGB or RGBA with color background */
+               if (g_sig)
+               {
+                  png_ptr->background_1.red = png_gamma_correct(png_ptr,
+                      png_ptr->background.red, g);
+                  png_ptr->background_1.green = png_gamma_correct(png_ptr,
+                      png_ptr->background.green, g);
+                  png_ptr->background_1.blue = png_gamma_correct(png_ptr,
+                      png_ptr->background.blue, g);
+               }
+               if (gs_sig)
+               {
+                  png_ptr->background.red = png_gamma_correct(png_ptr,
+                      png_ptr->background.red, gs);
+                  png_ptr->background.green = png_gamma_correct(png_ptr,
+                      png_ptr->background.green, gs);
+                  png_ptr->background.blue = png_gamma_correct(png_ptr,
+                      png_ptr->background.blue, gs);
+               }
+            }
+            else
+            {
+               /* GRAY, GRAY ALPHA, RGB, or RGBA with gray background */
+               png_ptr->background_1.red = png_ptr->background_1.green
+                   = png_ptr->background_1.blue = png_ptr->background_1.gray;
+               png_ptr->background.red = png_ptr->background.green
+                   = png_ptr->background.blue = png_ptr->background.gray;
+            }
+            /* The background is now in screen gamma: */
+            png_ptr->background_gamma_type = PNG_BACKGROUND_GAMMA_SCREEN;
+         } /* color_type != PNG_COLOR_TYPE_PALETTE */
+      }/* png_ptr->transformations & PNG_BACKGROUND */
+      else
+      /* Transformation does not include PNG_BACKGROUND */
+#endif /* PNG_READ_BACKGROUND_SUPPORTED */
+      if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+         /* RGB_TO_GRAY needs to have non-gamma-corrected values! */
+         && ((png_ptr->transformations & PNG_EXPAND) == 0 ||
+         (png_ptr->transformations & PNG_RGB_TO_GRAY) == 0)
+#endif
+         )
+      {
+         png_colorp palette = png_ptr->palette;
+         int num_palette = png_ptr->num_palette;
+         int i;
+         /*NOTE: there are other transformations that should probably be in here
+          * too.
+          */
+         for (i = 0; i < num_palette; i++)
+         {
+            palette[i].red = png_ptr->gamma_table[palette[i].red];
+            palette[i].green = png_ptr->gamma_table[palette[i].green];
+            palette[i].blue = png_ptr->gamma_table[palette[i].blue];
+         }
+         /* Done the gamma correction. */
+         png_ptr->transformations &= ~PNG_GAMMA;
+      } /* color_type == PALETTE && !PNG_BACKGROUND transformation */
+   }
+#ifdef PNG_READ_BACKGROUND_SUPPORTED
+   else
+#endif
+#endif /* PNG_READ_GAMMA_SUPPORTED */
+#ifdef PNG_READ_BACKGROUND_SUPPORTED
+   /* No GAMMA transformation (see the hanging else 4 lines above) */
+   if ((png_ptr->transformations & PNG_COMPOSE) &&
+       (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE))
+   {
+      int i;
+      int istop = (int)png_ptr->num_trans;
+      png_color back;
+      png_colorp palette = png_ptr->palette;
+      back.red   = (png_byte)png_ptr->background.red;
+      back.green = (png_byte)png_ptr->background.green;
+      back.blue  = (png_byte)png_ptr->background.blue;
+      for (i = 0; i < istop; i++)
+      {
+         if (png_ptr->trans_alpha[i] == 0)
+         {
+            palette[i] = back;
+         }
+         else if (png_ptr->trans_alpha[i] != 0xff)
+         {
+            /* The png_composite() macro is defined in png.h */
+            png_composite(palette[i].red, palette[i].red,
+                png_ptr->trans_alpha[i], back.red);
+            png_composite(palette[i].green, palette[i].green,
+                png_ptr->trans_alpha[i], back.green);
+            png_composite(palette[i].blue, palette[i].blue,
+                png_ptr->trans_alpha[i], back.blue);
+         }
+      }
+      png_ptr->transformations &= ~PNG_COMPOSE;
+   }
+#endif /* PNG_READ_BACKGROUND_SUPPORTED */
+#ifdef PNG_READ_SHIFT_SUPPORTED
+   if ((png_ptr->transformations & PNG_SHIFT) &&
+       (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE))
+   {
+      int i;
+      int istop = png_ptr->num_palette;
+      int shift = 8 - png_ptr->sig_bit.red;
+      /* significant bits can be in the range 1 to 7 for a meaninful result, if
+       * the number of significant bits is 0 then no shift is done (this is an
+       * error condition which is silently ignored.)
+       */
+      if (shift > 0 && shift < 8) for (i=0; i<istop; ++i)
+      {
+         int component = png_ptr->palette[i].red;
+         component >>= shift;
+         png_ptr->palette[i].red = (png_byte)component;
+      }
+      shift = 8 - png_ptr->sig_bit.green;
+      if (shift > 0 && shift < 8) for (i=0; i<istop; ++i)
+      {
+         int component = png_ptr->palette[i].green;
+         component >>= shift;
+         png_ptr->palette[i].green = (png_byte)component;
+      }
+      shift = 8 - png_ptr->sig_bit.blue;
+      if (shift > 0 && shift < 8) for (i=0; i<istop; ++i)
+      {
+         int component = png_ptr->palette[i].blue;
+         component >>= shift;
+         png_ptr->palette[i].blue = (png_byte)component;
+      }
+   }
+#endif  /* PNG_READ_SHIFT_SUPPORTED */
+}
+/* Modify the info structure to reflect the transformations.  The
+ * info should be updated so a PNG file could be written with it,
+ * assuming the transformations result in valid PNG data.
+ */
+void /* PRIVATE */
+png_read_transform_info(png_structp png_ptr, png_infop info_ptr)
+{
+   png_debug(1, "in png_read_transform_info");
+#ifdef PNG_READ_EXPAND_SUPPORTED
+   if (png_ptr->transformations & PNG_EXPAND)
+   {
+      if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+      {
+         /* This check must match what actually happens in
+          * png_do_expand_palette; if it ever checks the tRNS chunk to see if
+          * it is all opaque we must do the same (at present it does not.)
+          */
+         if (png_ptr->num_trans > 0)
+            info_ptr->color_type = PNG_COLOR_TYPE_RGB_ALPHA;
+         else
+            info_ptr->color_type = PNG_COLOR_TYPE_RGB;
+         info_ptr->bit_depth = 8;
+         info_ptr->num_trans = 0;
+      }
+      else
+      {
+         if (png_ptr->num_trans)
+         {
+            if (png_ptr->transformations & PNG_EXPAND_tRNS)
+               info_ptr->color_type |= PNG_COLOR_MASK_ALPHA;
+         }
+         if (info_ptr->bit_depth < 8)
+            info_ptr->bit_depth = 8;
+         info_ptr->num_trans = 0;
+      }
+   }
+#endif
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
+   defined(PNG_READ_ALPHA_MODE_SUPPORTED)
+   /* The following is almost certainly wrong unless the background value is in
+    * the screen space!
+    */
+   if (png_ptr->transformations & PNG_COMPOSE)
+      info_ptr->background = png_ptr->background;
+#endif
+#ifdef PNG_READ_GAMMA_SUPPORTED
+   /* The following used to be conditional on PNG_GAMMA (prior to 1.5.4),
+    * however it seems that the code in png_init_read_transformations, which has
+    * been called before this from png_read_update_info->png_read_start_row
+    * sometimes does the gamma transform and cancels the flag.
+    */
+   info_ptr->gamma = png_ptr->gamma;
+#endif
+   if (info_ptr->bit_depth == 16)
+   {
+#  ifdef PNG_READ_16BIT_SUPPORTED
+#     ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+         if (png_ptr->transformations & PNG_SCALE_16_TO_8)
+            info_ptr->bit_depth = 8;
+#     endif
+#     ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
+         if (png_ptr->transformations & PNG_16_TO_8)
+            info_ptr->bit_depth = 8;
+#     endif
+#  else
+      /* No 16 bit support: force chopping 16-bit input down to 8, in this case
+       * the app program can chose if both APIs are available by setting the
+       * correct scaling to use.
+       */
+#     ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
+         /* For compatibility with previous versions use the strip method by
+          * default.  This code works because if PNG_SCALE_16_TO_8 is already
+          * set the code below will do that in preference to the chop.
+          */
+         png_ptr->transformations |= PNG_16_TO_8;
+         info_ptr->bit_depth = 8;
+#     else
+#        ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+            png_ptr->transformations |= PNG_SCALE_16_TO_8;
+            info_ptr->bit_depth = 8;
+#        else
+            CONFIGURATION ERROR: you must enable at least one 16 to 8 method
+#        endif
+#    endif
+#endif /* !READ_16BIT_SUPPORTED */
+   }
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+   if (png_ptr->transformations & PNG_GRAY_TO_RGB)
+      info_ptr->color_type = (png_byte)(info_ptr->color_type |
+         PNG_COLOR_MASK_COLOR);
+#endif
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+   if (png_ptr->transformations & PNG_RGB_TO_GRAY)
+      info_ptr->color_type = (png_byte)(info_ptr->color_type &
+         ~PNG_COLOR_MASK_COLOR);
+#endif
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+   if (png_ptr->transformations & PNG_QUANTIZE)
+   {
+      if (((info_ptr->color_type == PNG_COLOR_TYPE_RGB) ||
+          (info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)) &&
+          png_ptr->palette_lookup && info_ptr->bit_depth == 8)
+      {
+         info_ptr->color_type = PNG_COLOR_TYPE_PALETTE;
+      }
+   }
+#endif
+#ifdef PNG_READ_EXPAND_16_SUPPORTED
+   if (png_ptr->transformations & PNG_EXPAND_16 && info_ptr->bit_depth == 8 &&
+      info_ptr->color_type != PNG_COLOR_TYPE_PALETTE)
+   {
+      info_ptr->bit_depth = 16;
+   }
+#endif
+#ifdef PNG_READ_PACK_SUPPORTED
+   if ((png_ptr->transformations & PNG_PACK) && (info_ptr->bit_depth < 8))
+      info_ptr->bit_depth = 8;
+#endif
+   if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+      info_ptr->channels = 1;
+   else if (info_ptr->color_type & PNG_COLOR_MASK_COLOR)
+      info_ptr->channels = 3;
+   else
+      info_ptr->channels = 1;
+#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
+   if (png_ptr->transformations & PNG_STRIP_ALPHA)
+   {
+      info_ptr->color_type = (png_byte)(info_ptr->color_type &
+         ~PNG_COLOR_MASK_ALPHA);
+      info_ptr->num_trans = 0;
+   }
+#endif
+   if (info_ptr->color_type & PNG_COLOR_MASK_ALPHA)
+      info_ptr->channels++;
+#ifdef PNG_READ_FILLER_SUPPORTED
+   /* STRIP_ALPHA and FILLER allowed:  MASK_ALPHA bit stripped above */
+   if ((png_ptr->transformations & PNG_FILLER) &&
+       ((info_ptr->color_type == PNG_COLOR_TYPE_RGB) ||
+       (info_ptr->color_type == PNG_COLOR_TYPE_GRAY)))
+   {
+      info_ptr->channels++;
+      /* If adding a true alpha channel not just filler */
+      if (png_ptr->transformations & PNG_ADD_ALPHA)
+         info_ptr->color_type |= PNG_COLOR_MASK_ALPHA;
+   }
+#endif
+#if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) && \
+defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
+   if (png_ptr->transformations & PNG_USER_TRANSFORM)
+   {
+      if (info_ptr->bit_depth < png_ptr->user_transform_depth)
+         info_ptr->bit_depth = png_ptr->user_transform_depth;
+      if (info_ptr->channels < png_ptr->user_transform_channels)
+         info_ptr->channels = png_ptr->user_transform_channels;
+   }
+#endif
+   info_ptr->pixel_depth = (png_byte)(info_ptr->channels *
+       info_ptr->bit_depth);
+   info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, info_ptr->width);
+   /* Adding in 1.5.4: cache the above value in png_struct so that we can later
+    * check in png_rowbytes that the user buffer won't get overwritten.  Note
+    * that the field is not always set - if png_read_update_info isn't called
+    * the application has to either not do any transforms or get the calculation
+    * right itself.
+    */
+   png_ptr->info_rowbytes = info_ptr->rowbytes;
+#ifndef PNG_READ_EXPAND_SUPPORTED
+   if (png_ptr)
+      return;
+#endif
+}
+/* Transform the row.  The order of transformations is significant,
+ * and is very touchy.  If you add a transformation, take care to
+ * decide how it fits in with the other transformations here.
+ */
+void /* PRIVATE */
+png_do_read_transformations(png_structp png_ptr, png_row_infop row_info)
+{
+   png_debug(1, "in png_do_read_transformations");
+   if (png_ptr->row_buf == NULL)
+   {
+      /* Prior to 1.5.4 this output row/pass where the NULL pointer is, but this
+       * error is incredibly rare and incredibly easy to debug without this
+       * information.
+       */
+      png_error(png_ptr, "NULL row buffer");
+   }
+   /* The following is debugging; prior to 1.5.4 the code was never compiled in;
+    * in 1.5.4 PNG_FLAG_DETECT_UNINITIALIZED was added and the macro
+    * PNG_WARN_UNINITIALIZED_ROW removed.  In 1.5 the new flag is set only for
+    * selected new APIs to ensure that there is no API change.
+    */
+   if ((png_ptr->flags & PNG_FLAG_DETECT_UNINITIALIZED) != 0 &&
+      !(png_ptr->flags & PNG_FLAG_ROW_INIT))
+   {
+      /* Application has failed to call either png_read_start_image() or
+       * png_read_update_info() after setting transforms that expand pixels.
+       * This check added to libpng-1.2.19 (but not enabled until 1.5.4).
+       */
+      png_error(png_ptr, "Uninitialized row");
+   }
+#ifdef PNG_READ_EXPAND_SUPPORTED
+   if (png_ptr->transformations & PNG_EXPAND)
+   {
+      if (row_info->color_type == PNG_COLOR_TYPE_PALETTE)
+      {
+         png_do_expand_palette(row_info, png_ptr->row_buf + 1,
+             png_ptr->palette, png_ptr->trans_alpha, png_ptr->num_trans);
+      }
+      else
+      {
+         if (png_ptr->num_trans &&
+             (png_ptr->transformations & PNG_EXPAND_tRNS))
+            png_do_expand(row_info, png_ptr->row_buf + 1,
+                &(png_ptr->trans_color));
+         else
+            png_do_expand(row_info, png_ptr->row_buf + 1,
+                NULL);
+      }
+   }
+#endif
+#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
+   if ((png_ptr->transformations & PNG_STRIP_ALPHA) &&
+      !(png_ptr->transformations & PNG_COMPOSE) &&
+      (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
+      row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA))
+      png_do_strip_channel(row_info, png_ptr->row_buf + 1,
+         0 /* at_start == false, because SWAP_ALPHA happens later */);
+#endif
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+   if (png_ptr->transformations & PNG_RGB_TO_GRAY)
+   {
+      int rgb_error =
+          png_do_rgb_to_gray(png_ptr, row_info,
+              png_ptr->row_buf + 1);
+      if (rgb_error)
+      {
+         png_ptr->rgb_to_gray_status=1;
+         if ((png_ptr->transformations & PNG_RGB_TO_GRAY) ==
+             PNG_RGB_TO_GRAY_WARN)
+            png_warning(png_ptr, "png_do_rgb_to_gray found nongray pixel");
+         if ((png_ptr->transformations & PNG_RGB_TO_GRAY) ==
+             PNG_RGB_TO_GRAY_ERR)
+            png_error(png_ptr, "png_do_rgb_to_gray found nongray pixel");
+      }
+   }
+#endif
+/* From Andreas Dilger e-mail to png-implement, 26 March 1998:
+ *
+ *   In most cases, the "simple transparency" should be done prior to doing
+ *   gray-to-RGB, or you will have to test 3x as many bytes to check if a
+ *   pixel is transparent.  You would also need to make sure that the
+ *   transparency information is upgraded to RGB.
+ *
+ *   To summarize, the current flow is:
+ *   - Gray + simple transparency -> compare 1 or 2 gray bytes and composite
+ *                                   with background "in place" if transparent,
+ *                                   convert to RGB if necessary
+ *   - Gray + alpha -> composite with gray background and remove alpha bytes,
+ *                                   convert to RGB if necessary
+ *
+ *   To support RGB backgrounds for gray images we need:
+ *   - Gray + simple transparency -> convert to RGB + simple transparency,
+ *                                   compare 3 or 6 bytes and composite with
+ *                                   background "in place" if transparent
+ *                                   (3x compare/pixel compared to doing
+ *                                   composite with gray bkgrnd)
+ *   - Gray + alpha -> convert to RGB + alpha, composite with background and
+ *                                   remove alpha bytes (3x float
+ *                                   operations/pixel compared with composite
+ *                                   on gray background)
+ *
+ *  Greg's change will do this.  The reason it wasn't done before is for
+ *  performance, as this increases the per-pixel operations.  If we would check
+ *  in advance if the background was gray or RGB, and position the gray-to-RGB
+ *  transform appropriately, then it would save a lot of work/time.
+ */
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+   /* If gray -> RGB, do so now only if background is non-gray; else do later
+    * for performance reasons
+    */
+   if ((png_ptr->transformations & PNG_GRAY_TO_RGB) &&
+       !(png_ptr->mode & PNG_BACKGROUND_IS_GRAY))
+      png_do_gray_to_rgb(row_info, png_ptr->row_buf + 1);
+#endif
+#if (defined PNG_READ_BACKGROUND_SUPPORTED) ||\
+   (defined PNG_READ_ALPHA_MODE_SUPPORTED)
+   if (png_ptr->transformations & PNG_COMPOSE)
+      png_do_compose(row_info, png_ptr->row_buf + 1, png_ptr);
+#endif
+#ifdef PNG_READ_GAMMA_SUPPORTED
+   if ((png_ptr->transformations & PNG_GAMMA) &&
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+      /* Because RGB_TO_GRAY does the gamma transform. */
+      !(png_ptr->transformations & PNG_RGB_TO_GRAY) &&
+#endif
+#if (defined PNG_READ_BACKGROUND_SUPPORTED) ||\
+   (defined PNG_READ_ALPHA_MODE_SUPPORTED)
+      /* Because PNG_COMPOSE does the gamma transform if there is something to
+       * do (if there is an alpha channel or transparency.)
+       */
+       !((png_ptr->transformations & PNG_COMPOSE) &&
+       ((png_ptr->num_trans != 0) ||
+       (png_ptr->color_type & PNG_COLOR_MASK_ALPHA))) &&
+#endif
+      /* Because png_init_read_transformations transforms the palette, unless
+       * RGB_TO_GRAY will do the transform.
+       */
+       (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE))
+      png_do_gamma(row_info, png_ptr->row_buf + 1, png_ptr);
+#endif
+#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
+   if ((png_ptr->transformations & PNG_STRIP_ALPHA) &&
+      (png_ptr->transformations & PNG_COMPOSE) &&
+      (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
+      row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA))
+      png_do_strip_channel(row_info, png_ptr->row_buf + 1,
+         0 /* at_start == false, because SWAP_ALPHA happens later */);
+#endif
+#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+   if ((png_ptr->transformations & PNG_ENCODE_ALPHA) &&
+      (row_info->color_type & PNG_COLOR_MASK_ALPHA))
+      png_do_encode_alpha(row_info, png_ptr->row_buf + 1, png_ptr);
+#endif
+#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+   if (png_ptr->transformations & PNG_SCALE_16_TO_8)
+      png_do_scale_16_to_8(row_info, png_ptr->row_buf + 1);
+#endif
+#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
+   /* There is no harm in doing both of these because only one has any effect,
+    * by putting the 'scale' option first if the app asks for scale (either by
+    * calling the API or in a TRANSFORM flag) this is what happens.
+    */
+   if (png_ptr->transformations & PNG_16_TO_8)
+      png_do_chop(row_info, png_ptr->row_buf + 1);
+#endif
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+   if (png_ptr->transformations & PNG_QUANTIZE)
+   {
+      png_do_quantize(row_info, png_ptr->row_buf + 1,
+          png_ptr->palette_lookup, png_ptr->quantize_index);
+      if (row_info->rowbytes == 0)
+         png_error(png_ptr, "png_do_quantize returned rowbytes=0");
+   }
+#endif /* PNG_READ_QUANTIZE_SUPPORTED */
+#ifdef PNG_READ_EXPAND_16_SUPPORTED
+   /* Do the expansion now, after all the arithmetic has been done.  Notice
+    * that previous transformations can handle the PNG_EXPAND_16 flag if this
+    * is efficient (particularly true in the case of gamma correction, where
+    * better accuracy results faster!)
+    */
+   if (png_ptr->transformations & PNG_EXPAND_16)
+      png_do_expand_16(row_info, png_ptr->row_buf + 1);
+#endif
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+   /*NOTE: moved here in 1.5.4 (from much later in this list.) */
+   if ((png_ptr->transformations & PNG_GRAY_TO_RGB) &&
+       (png_ptr->mode & PNG_BACKGROUND_IS_GRAY))
+      png_do_gray_to_rgb(row_info, png_ptr->row_buf + 1);
+#endif
+#ifdef PNG_READ_INVERT_SUPPORTED
+   if (png_ptr->transformations & PNG_INVERT_MONO)
+      png_do_invert(row_info, png_ptr->row_buf + 1);
+#endif
+#ifdef PNG_READ_SHIFT_SUPPORTED
+   if (png_ptr->transformations & PNG_SHIFT)
+      png_do_unshift(row_info, png_ptr->row_buf + 1,
+          &(png_ptr->shift));
+#endif
+#ifdef PNG_READ_PACK_SUPPORTED
+   if (png_ptr->transformations & PNG_PACK)
+      png_do_unpack(row_info, png_ptr->row_buf + 1);
+#endif
+#ifdef PNG_READ_BGR_SUPPORTED
+   if (png_ptr->transformations & PNG_BGR)
+      png_do_bgr(row_info, png_ptr->row_buf + 1);
+#endif
+#ifdef PNG_READ_PACKSWAP_SUPPORTED
+   if (png_ptr->transformations & PNG_PACKSWAP)
+      png_do_packswap(row_info, png_ptr->row_buf + 1);
+#endif
+#ifdef PNG_READ_FILLER_SUPPORTED
+   if (png_ptr->transformations & PNG_FILLER)
+      png_do_read_filler(row_info, png_ptr->row_buf + 1,
+          (png_uint_32)png_ptr->filler, png_ptr->flags);
+#endif
+#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
+   if (png_ptr->transformations & PNG_INVERT_ALPHA)
+      png_do_read_invert_alpha(row_info, png_ptr->row_buf + 1);
+#endif
+#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
+   if (png_ptr->transformations & PNG_SWAP_ALPHA)
+      png_do_read_swap_alpha(row_info, png_ptr->row_buf + 1);
+#endif
+#ifdef PNG_READ_16BIT_SUPPORTED
+#ifdef PNG_READ_SWAP_SUPPORTED
+   if (png_ptr->transformations & PNG_SWAP_BYTES)
+      png_do_swap(row_info, png_ptr->row_buf + 1);
+#endif
+#endif
+#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
+   if (png_ptr->transformations & PNG_USER_TRANSFORM)
+    {
+      if (png_ptr->read_user_transform_fn != NULL)
+         (*(png_ptr->read_user_transform_fn)) /* User read transform function */
+             (png_ptr,     /* png_ptr */
+             row_info,     /* row_info: */
+                /*  png_uint_32 width;       width of row */
+                /*  png_size_t rowbytes;     number of bytes in row */
+                /*  png_byte color_type;     color type of pixels */
+                /*  png_byte bit_depth;      bit depth of samples */
+                /*  png_byte channels;       number of channels (1-4) */
+                /*  png_byte pixel_depth;    bits per pixel (depth*channels) */
+             png_ptr->row_buf + 1);    /* start of pixel data for row */
+#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
+      if (png_ptr->user_transform_depth)
+         row_info->bit_depth = png_ptr->user_transform_depth;
+      if (png_ptr->user_transform_channels)
+         row_info->channels = png_ptr->user_transform_channels;
+#endif
+      row_info->pixel_depth = (png_byte)(row_info->bit_depth *
+          row_info->channels);
+      row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_info->width);
+   }
+#endif
+}
+#ifdef PNG_READ_PACK_SUPPORTED
+/* Unpack pixels of 1, 2, or 4 bits per pixel into 1 byte per pixel,
+ * without changing the actual values.  Thus, if you had a row with
+ * a bit depth of 1, you would end up with bytes that only contained
+ * the numbers 0 or 1.  If you would rather they contain 0 and 255, use
+ * png_do_shift() after this.
+ */
+void /* PRIVATE */
+png_do_unpack(png_row_infop row_info, png_bytep row)
+{
+   png_debug(1, "in png_do_unpack");
+   if (row_info->bit_depth < 8)
+   {
+      png_uint_32 i;
+      png_uint_32 row_width=row_info->width;
+      switch (row_info->bit_depth)
+      {
+         case 1:
+         {
+            png_bytep sp = row + (png_size_t)((row_width - 1) >> 3);
+            png_bytep dp = row + (png_size_t)row_width - 1;
+            png_uint_32 shift = 7 - (int)((row_width + 7) & 0x07);
+            for (i = 0; i < row_width; i++)
+            {
+               *dp = (png_byte)((*sp >> shift) & 0x01);
+               if (shift == 7)
+               {
+                  shift = 0;
+                  sp--;
+               }
+               else
+                  shift++;
+               dp--;
+            }
+            break;
+         }
+         case 2:
+         {
+            png_bytep sp = row + (png_size_t)((row_width - 1) >> 2);
+            png_bytep dp = row + (png_size_t)row_width - 1;
+            png_uint_32 shift = (int)((3 - ((row_width + 3) & 0x03)) << 1);
+            for (i = 0; i < row_width; i++)
+            {
+               *dp = (png_byte)((*sp >> shift) & 0x03);
+               if (shift == 6)
+               {
+                  shift = 0;
+                  sp--;
+               }
+               else
+                  shift += 2;
+               dp--;
+            }
+            break;
+         }
+         case 4:
+         {
+            png_bytep sp = row + (png_size_t)((row_width - 1) >> 1);
+            png_bytep dp = row + (png_size_t)row_width - 1;
+            png_uint_32 shift = (int)((1 - ((row_width + 1) & 0x01)) << 2);
+            for (i = 0; i < row_width; i++)
+            {
+               *dp = (png_byte)((*sp >> shift) & 0x0f);
+               if (shift == 4)
+               {
+                  shift = 0;
+                  sp--;
+               }
+               else
+                  shift = 4;
+               dp--;
+            }
+            break;
+         }
+         default:
+            break;
+      }
+      row_info->bit_depth = 8;
+      row_info->pixel_depth = (png_byte)(8 * row_info->channels);
+      row_info->rowbytes = row_width * row_info->channels;
+   }
+}
+#endif
+#ifdef PNG_READ_SHIFT_SUPPORTED
+/* Reverse the effects of png_do_shift.  This routine merely shifts the
+ * pixels back to their significant bits values.  Thus, if you have
+ * a row of bit depth 8, but only 5 are significant, this will shift
+ * the values back to 0 through 31.
+ */
+void /* PRIVATE */
+png_do_unshift(png_row_infop row_info, png_bytep row,
+    png_const_color_8p sig_bits)
+{
+   int color_type;
+   png_debug(1, "in png_do_unshift");
+   /* The palette case has already been handled in the _init routine. */
+   color_type = row_info->color_type;
+   if (color_type != PNG_COLOR_TYPE_PALETTE)
+   {
+      int shift[4];
+      int channels = 0;
+      int bit_depth = row_info->bit_depth;
+      if (color_type & PNG_COLOR_MASK_COLOR)
+      {
+         shift[channels++] = bit_depth - sig_bits->red;
+         shift[channels++] = bit_depth - sig_bits->green;
+         shift[channels++] = bit_depth - sig_bits->blue;
+      }
+      else
+      {
+         shift[channels++] = bit_depth - sig_bits->gray;
+      }
+      if (color_type & PNG_COLOR_MASK_ALPHA)
+      {
+         shift[channels++] = bit_depth - sig_bits->alpha;
+      }
+      {
+         int c, have_shift;
+         for (c = have_shift = 0; c < channels; ++c)
+         {
+            /* A shift of more than the bit depth is an error condition but it
+             * gets ignored here.
+             */
+            if (shift[c] <= 0 || shift[c] >= bit_depth)
+               shift[c] = 0;
+            else
+               have_shift = 1;
+         }
+         if (!have_shift)
+            return;
+      }
+      switch (bit_depth)
+      {
+         default:
+         /* Must be 1bpp gray: should not be here! */
+            /* NOTREACHED */
+            break;
+         case 2:
+         /* Must be 2bpp gray */
+         /* assert(channels == 1 && shift[0] == 1) */
+         {
+            png_bytep bp = row;
+            png_bytep bp_end = bp + row_info->rowbytes;
+            while (bp < bp_end)
+            {
+               int b = (*bp >> 1) & 0x55;
+               *bp++ = (png_byte)b;
+            }
+            break;
+         }
+         case 4:
+         /* Must be 4bpp gray */
+         /* assert(channels == 1) */
+         {
+            png_bytep bp = row;
+            png_bytep bp_end = bp + row_info->rowbytes;
+            int gray_shift = shift[0];
+            int mask =  0xf >> gray_shift;
+            mask |= mask << 4;
+            while (bp < bp_end)
+            {
+               int b = (*bp >> gray_shift) & mask;
+               *bp++ = (png_byte)b;
+            }
+            break;
+         }
+         case 8:
+         /* Single byte components, G, GA, RGB, RGBA */
+         {
+            png_bytep bp = row;
+            png_bytep bp_end = bp + row_info->rowbytes;
+            int channel = 0;
+            while (bp < bp_end)
+            {
+               int b = *bp >> shift[channel];
+               if (++channel >= channels)
+                  channel = 0;
+               *bp++ = (png_byte)b;
+            }
+            break;
+         }
+#ifdef PNG_READ_16BIT_SUPPORTED
+         case 16:
+         /* Double byte components, G, GA, RGB, RGBA */
+         {
+            png_bytep bp = row;
+            png_bytep bp_end = bp + row_info->rowbytes;
+            int channel = 0;
+            while (bp < bp_end)
+            {
+               int value = (bp[0] << 8) + bp[1];
+               value >>= shift[channel];
+               if (++channel >= channels)
+                  channel = 0;
+               *bp++ = (png_byte)(value >> 8);
+               *bp++ = (png_byte)(value & 0xff);
+            }
+            break;
+         }
+#endif
+      }
+   }
+}
+#endif
+#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+/* Scale rows of bit depth 16 down to 8 accurately */
+void /* PRIVATE */
+png_do_scale_16_to_8(png_row_infop row_info, png_bytep row)
+{
+   png_debug(1, "in png_do_scale_16_to_8");
+   if (row_info->bit_depth == 16)
+   {
+      png_bytep sp = row; /* source */
+      png_bytep dp = row; /* destination */
+      png_bytep ep = sp + row_info->rowbytes; /* end+1 */
+      while (sp < ep)
+      {
+         /* The input is an array of 16 bit components, these must be scaled to
+          * 8 bits each.  For a 16 bit value V the required value (from the PNG
+          * specification) is:
+          *
+          *    (V * 255) / 65535
+          *
+          * This reduces to round(V / 257), or floor((V + 128.5)/257)
+          *
+          * Represent V as the two byte value vhi.vlo.  Make a guess that the
+          * result is the top byte of V, vhi, then the correction to this value
+          * is:
+          *
+          *    error = floor(((V-vhi.vhi) + 128.5) / 257)
+          *          = floor(((vlo-vhi) + 128.5) / 257)
+          *
+          * This can be approximated using integer arithmetic (and a signed
+          * shift):
+          *
+          *    error = (vlo-vhi+128) >> 8;
+          *
+          * The approximate differs from the exact answer only when (vlo-vhi) is
+          * 128; it then gives a correction of +1 when the exact correction is
+          * 0.  This gives 128 errors.  The exact answer (correct for all 16 bit
+          * input values) is:
+          *
+          *    error = (vlo-vhi+128)*65535 >> 24;
+          *
+          * An alternative arithmetic calculation which also gives no errors is:
+          *
+          *    (V * 255 + 32895) >> 16
+          */
+         png_int_32 tmp = *sp++; /* must be signed! */
+         tmp += (((int)*sp++ - tmp + 128) * 65535) >> 24;
+         *dp++ = (png_byte)tmp;
+      }
+      row_info->bit_depth = 8;
+      row_info->pixel_depth = (png_byte)(8 * row_info->channels);
+      row_info->rowbytes = row_info->width * row_info->channels;
+   }
+}
+#endif
+#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
+void /* PRIVATE */
+/* Simply discard the low byte.  This was the default behavior prior
+ * to libpng-1.5.4.
+ */
+png_do_chop(png_row_infop row_info, png_bytep row)
+{
+   png_debug(1, "in png_do_chop");
+   if (row_info->bit_depth == 16)
+   {
+      png_bytep sp = row; /* source */
+      png_bytep dp = row; /* destination */
+      png_bytep ep = sp + row_info->rowbytes; /* end+1 */
+      while (sp < ep)
+      {
+         *dp++ = *sp;
+         sp += 2; /* skip low byte */
+      }
+      row_info->bit_depth = 8;
+      row_info->pixel_depth = (png_byte)(8 * row_info->channels);
+      row_info->rowbytes = row_info->width * row_info->channels;
+   }
+}
+#endif
+#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
+void /* PRIVATE */
+png_do_read_swap_alpha(png_row_infop row_info, png_bytep row)
+{
+   png_debug(1, "in png_do_read_swap_alpha");
+   {
+      png_uint_32 row_width = row_info->width;
+      if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+      {
+         /* This converts from RGBA to ARGB */
+         if (row_info->bit_depth == 8)
+         {
+            png_bytep sp = row + row_info->rowbytes;
+            png_bytep dp = sp;
+            png_byte save;
+            png_uint_32 i;
+            for (i = 0; i < row_width; i++)
+            {
+               save = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = save;
+            }
+         }
+#ifdef PNG_READ_16BIT_SUPPORTED
+         /* This converts from RRGGBBAA to AARRGGBB */
+         else
+         {
+            png_bytep sp = row + row_info->rowbytes;
+            png_bytep dp = sp;
+            png_byte save[2];
+            png_uint_32 i;
+            for (i = 0; i < row_width; i++)
+            {
+               save[0] = *(--sp);
+               save[1] = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = save[0];
+               *(--dp) = save[1];
+            }
+         }
+#endif
+      }
+      else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+      {
+         /* This converts from GA to AG */
+         if (row_info->bit_depth == 8)
+         {
+            png_bytep sp = row + row_info->rowbytes;
+            png_bytep dp = sp;
+            png_byte save;
+            png_uint_32 i;
+            for (i = 0; i < row_width; i++)
+            {
+               save = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = save;
+            }
+         }
+#ifdef PNG_READ_16BIT_SUPPORTED
+         /* This converts from GGAA to AAGG */
+         else
+         {
+            png_bytep sp = row + row_info->rowbytes;
+            png_bytep dp = sp;
+            png_byte save[2];
+            png_uint_32 i;
+            for (i = 0; i < row_width; i++)
+            {
+               save[0] = *(--sp);
+               save[1] = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = save[0];
+               *(--dp) = save[1];
+            }
+         }
+#endif
+      }
+   }
+}
+#endif
+#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
+void /* PRIVATE */
+png_do_read_invert_alpha(png_row_infop row_info, png_bytep row)
+{
+   png_uint_32 row_width;
+   png_debug(1, "in png_do_read_invert_alpha");
+   row_width = row_info->width;
+   if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+   {
+      if (row_info->bit_depth == 8)
+      {
+         /* This inverts the alpha channel in RGBA */
+         png_bytep sp = row + row_info->rowbytes;
+         png_bytep dp = sp;
+         png_uint_32 i;
+         for (i = 0; i < row_width; i++)
+         {
+            *(--dp) = (png_byte)(255 - *(--sp));
+/*          This does nothing:
+            *(--dp) = *(--sp);
+            *(--dp) = *(--sp);
+            *(--dp) = *(--sp);
+            We can replace it with:
+*/
+            sp-=3;
+            dp=sp;
+         }
+      }
+#ifdef PNG_READ_16BIT_SUPPORTED
+      /* This inverts the alpha channel in RRGGBBAA */
+      else
+      {
+         png_bytep sp = row + row_info->rowbytes;
+         png_bytep dp = sp;
+         png_uint_32 i;
+         for (i = 0; i < row_width; i++)
+         {
+            *(--dp) = (png_byte)(255 - *(--sp));
+            *(--dp) = (png_byte)(255 - *(--sp));
+/*          This does nothing:
+            *(--dp) = *(--sp);
+            *(--dp) = *(--sp);
+            *(--dp) = *(--sp);
+            *(--dp) = *(--sp);
+            *(--dp) = *(--sp);
+            *(--dp) = *(--sp);
+            We can replace it with:
+*/
+            sp-=6;
+            dp=sp;
+         }
+      }
+#endif
+   }
+   else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+   {
+      if (row_info->bit_depth == 8)
+      {
+         /* This inverts the alpha channel in GA */
+         png_bytep sp = row + row_info->rowbytes;
+         png_bytep dp = sp;
+         png_uint_32 i;
+         for (i = 0; i < row_width; i++)
+         {
+            *(--dp) = (png_byte)(255 - *(--sp));
+            *(--dp) = *(--sp);
+         }
+      }
+#ifdef PNG_READ_16BIT_SUPPORTED
+      else
+      {
+         /* This inverts the alpha channel in GGAA */
+         png_bytep sp  = row + row_info->rowbytes;
+         png_bytep dp = sp;
+         png_uint_32 i;
+         for (i = 0; i < row_width; i++)
+         {
+            *(--dp) = (png_byte)(255 - *(--sp));
+            *(--dp) = (png_byte)(255 - *(--sp));
+/*
+            *(--dp) = *(--sp);
+            *(--dp) = *(--sp);
+*/
+            sp-=2;
+            dp=sp;
+         }
+      }
+#endif
+   }
+}
+#endif
+#ifdef PNG_READ_FILLER_SUPPORTED
+/* Add filler channel if we have RGB color */
+void /* PRIVATE */
+png_do_read_filler(png_row_infop row_info, png_bytep row,
+    png_uint_32 filler, png_uint_32 flags)
+{
+   png_uint_32 i;
+   png_uint_32 row_width = row_info->width;
+#ifdef PNG_READ_16BIT_SUPPORTED
+   png_byte hi_filler = (png_byte)((filler>>8) & 0xff);
+#endif
+   png_byte lo_filler = (png_byte)(filler & 0xff);
+   png_debug(1, "in png_do_read_filler");
+   if (
+       row_info->color_type == PNG_COLOR_TYPE_GRAY)
+   {
+      if (row_info->bit_depth == 8)
+      {
+         if (flags & PNG_FLAG_FILLER_AFTER)
+         {
+            /* This changes the data from G to GX */
+            png_bytep sp = row + (png_size_t)row_width;
+            png_bytep dp =  sp + (png_size_t)row_width;
+            for (i = 1; i < row_width; i++)
+            {
+               *(--dp) = lo_filler;
+               *(--dp) = *(--sp);
+            }
+            *(--dp) = lo_filler;
+            row_info->channels = 2;
+            row_info->pixel_depth = 16;
+            row_info->rowbytes = row_width * 2;
+         }
+         else
+         {
+            /* This changes the data from G to XG */
+            png_bytep sp = row + (png_size_t)row_width;
+            png_bytep dp = sp  + (png_size_t)row_width;
+            for (i = 0; i < row_width; i++)
+            {
+               *(--dp) = *(--sp);
+               *(--dp) = lo_filler;
+            }
+            row_info->channels = 2;
+            row_info->pixel_depth = 16;
+            row_info->rowbytes = row_width * 2;
+         }
+      }
+#ifdef PNG_READ_16BIT_SUPPORTED
+      else if (row_info->bit_depth == 16)
+      {
+         if (flags & PNG_FLAG_FILLER_AFTER)
+         {
+            /* This changes the data from GG to GGXX */
+            png_bytep sp = row + (png_size_t)row_width * 2;
+            png_bytep dp = sp  + (png_size_t)row_width * 2;
+            for (i = 1; i < row_width; i++)
+            {
+               *(--dp) = hi_filler;
+               *(--dp) = lo_filler;
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+            }
+            *(--dp) = hi_filler;
+            *(--dp) = lo_filler;
+            row_info->channels = 2;
+            row_info->pixel_depth = 32;
+            row_info->rowbytes = row_width * 4;
+         }
+         else
+         {
+            /* This changes the data from GG to XXGG */
+            png_bytep sp = row + (png_size_t)row_width * 2;
+            png_bytep dp = sp  + (png_size_t)row_width * 2;
+            for (i = 0; i < row_width; i++)
+            {
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = hi_filler;
+               *(--dp) = lo_filler;
+            }
+            row_info->channels = 2;
+            row_info->pixel_depth = 32;
+            row_info->rowbytes = row_width * 4;
+         }
+      }
+#endif
+   } /* COLOR_TYPE == GRAY */
+   else if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+   {
+      if (row_info->bit_depth == 8)
+      {
+         if (flags & PNG_FLAG_FILLER_AFTER)
+         {
+            /* This changes the data from RGB to RGBX */
+            png_bytep sp = row + (png_size_t)row_width * 3;
+            png_bytep dp = sp  + (png_size_t)row_width;
+            for (i = 1; i < row_width; i++)
+            {
+               *(--dp) = lo_filler;
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+            }
+            *(--dp) = lo_filler;
+            row_info->channels = 4;
+            row_info->pixel_depth = 32;
+            row_info->rowbytes = row_width * 4;
+         }
+         else
+         {
+            /* This changes the data from RGB to XRGB */
+            png_bytep sp = row + (png_size_t)row_width * 3;
+            png_bytep dp = sp + (png_size_t)row_width;
+            for (i = 0; i < row_width; i++)
+            {
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = lo_filler;
+            }
+            row_info->channels = 4;
+            row_info->pixel_depth = 32;
+            row_info->rowbytes = row_width * 4;
+         }
+      }
+#ifdef PNG_READ_16BIT_SUPPORTED
+      else if (row_info->bit_depth == 16)
+      {
+         if (flags & PNG_FLAG_FILLER_AFTER)
+         {
+            /* This changes the data from RRGGBB to RRGGBBXX */
+            png_bytep sp = row + (png_size_t)row_width * 6;
+            png_bytep dp = sp  + (png_size_t)row_width * 2;
+            for (i = 1; i < row_width; i++)
+            {
+               *(--dp) = hi_filler;
+               *(--dp) = lo_filler;
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+            }
+            *(--dp) = hi_filler;
+            *(--dp) = lo_filler;
+            row_info->channels = 4;
+            row_info->pixel_depth = 64;
+            row_info->rowbytes = row_width * 8;
+         }
+         else
+         {
+            /* This changes the data from RRGGBB to XXRRGGBB */
+            png_bytep sp = row + (png_size_t)row_width * 6;
+            png_bytep dp = sp  + (png_size_t)row_width * 2;
+            for (i = 0; i < row_width; i++)
+            {
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = hi_filler;
+               *(--dp) = lo_filler;
+            }
+            row_info->channels = 4;
+            row_info->pixel_depth = 64;
+            row_info->rowbytes = row_width * 8;
+         }
+      }
+#endif
+   } /* COLOR_TYPE == RGB */
+}
+#endif
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+/* Expand grayscale files to RGB, with or without alpha */
+void /* PRIVATE */
+png_do_gray_to_rgb(png_row_infop row_info, png_bytep row)
+{
+   png_uint_32 i;
+   png_uint_32 row_width = row_info->width;
+   png_debug(1, "in png_do_gray_to_rgb");
+   if (row_info->bit_depth >= 8 &&
+       !(row_info->color_type & PNG_COLOR_MASK_COLOR))
+   {
+      if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
+      {
+         if (row_info->bit_depth == 8)
+         {
+            /* This changes G to RGB */
+            png_bytep sp = row + (png_size_t)row_width - 1;
+            png_bytep dp = sp  + (png_size_t)row_width * 2;
+            for (i = 0; i < row_width; i++)
+            {
+               *(dp--) = *sp;
+               *(dp--) = *sp;
+               *(dp--) = *(sp--);
+            }
+         }
+         else
+         {
+            /* This changes GG to RRGGBB */
+            png_bytep sp = row + (png_size_t)row_width * 2 - 1;
+            png_bytep dp = sp  + (png_size_t)row_width * 4;
+            for (i = 0; i < row_width; i++)
+            {
+               *(dp--) = *sp;
+               *(dp--) = *(sp - 1);
+               *(dp--) = *sp;
+               *(dp--) = *(sp - 1);
+               *(dp--) = *(sp--);
+               *(dp--) = *(sp--);
+            }
+         }
+      }
+      else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+      {
+         if (row_info->bit_depth == 8)
+         {
+            /* This changes GA to RGBA */
+            png_bytep sp = row + (png_size_t)row_width * 2 - 1;
+            png_bytep dp = sp  + (png_size_t)row_width * 2;
+            for (i = 0; i < row_width; i++)
+            {
+               *(dp--) = *(sp--);
+               *(dp--) = *sp;
+               *(dp--) = *sp;
+               *(dp--) = *(sp--);
+            }
+         }
+         else
+         {
+            /* This changes GGAA to RRGGBBAA */
+            png_bytep sp = row + (png_size_t)row_width * 4 - 1;
+            png_bytep dp = sp  + (png_size_t)row_width * 4;
+            for (i = 0; i < row_width; i++)
+            {
+               *(dp--) = *(sp--);
+               *(dp--) = *(sp--);
+               *(dp--) = *sp;
+               *(dp--) = *(sp - 1);
+               *(dp--) = *sp;
+               *(dp--) = *(sp - 1);
+               *(dp--) = *(sp--);
+               *(dp--) = *(sp--);
+            }
+         }
+      }
+      row_info->channels = (png_byte)(row_info->channels + 2);
+      row_info->color_type |= PNG_COLOR_MASK_COLOR;
+      row_info->pixel_depth = (png_byte)(row_info->channels *
+          row_info->bit_depth);
+      row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
+   }
+}
+#endif
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+/* Reduce RGB files to grayscale, with or without alpha
+ * using the equation given in Poynton's ColorFAQ of 1998-01-04 at
+ * <http://www.inforamp.net/~poynton/>  (THIS LINK IS DEAD June 2008 but
+ * versions dated 1998 through November 2002 have been archived at
+ * http://web.archive.org/web/20000816232553/http://www.inforamp.net/
+ * ~poynton/notes/colour_and_gamma/ColorFAQ.txt )
+ * Charles Poynton poynton at poynton.com
+ *
+ *     Y = 0.212671 * R + 0.715160 * G + 0.072169 * B
+ *
+ *  which can be expressed with integers as
+ *
+ *     Y = (6969 * R + 23434 * G + 2365 * B)/32768
+ *
+ * Poynton's current link (as of January 2003 through July 2011):
+ * <http://www.poynton.com/notes/colour_and_gamma/>
+ * has changed the numbers slightly:
+ *
+ *     Y = 0.2126*R + 0.7152*G + 0.0722*B
+ *
+ *  which can be expressed with integers as
+ *
+ *     Y = (6966 * R + 23436 * G + 2366 * B)/32768
+ *
+ *  Historically, however, libpng uses numbers derived from the ITU-R Rec 709
+ *  end point chromaticities and the D65 white point.  Depending on the
+ *  precision used for the D65 white point this produces a variety of different
+ *  numbers, however if the four decimal place value used in ITU-R Rec 709 is
+ *  used (0.3127,0.3290) the Y calculation would be:
+ *
+ *     Y = (6968 * R + 23435 * G + 2366 * B)/32768
+ *
+ *  While this is correct the rounding results in an overflow for white, because
+ *  the sum of the rounded coefficients is 32769, not 32768.  Consequently
+ *  libpng uses, instead, the closest non-overflowing approximation:
+ *
+ *     Y = (6968 * R + 23434 * G + 2366 * B)/32768
+ *
+ *  Starting with libpng-1.5.5, if the image being converted has a cHRM chunk
+ *  (including an sRGB chunk) then the chromaticities are used to calculate the
+ *  coefficients.  See the chunk handling in pngrutil.c for more information.
+ *
+ *  In all cases the calculation is to be done in a linear colorspace.  If no
+ *  gamma information is available to correct the encoding of the original RGB
+ *  values this results in an implicit assumption that the original PNG RGB
+ *  values were linear.
+ *
+ *  Other integer coefficents can be used via png_set_rgb_to_gray().  Because
+ *  the API takes just red and green coefficients the blue coefficient is
+ *  calculated to make the sum 32768.  This will result in different rounding
+ *  to that used above.
+ */
+int /* PRIVATE */
+png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row)
+{
+   int rgb_error = 0;
+   png_debug(1, "in png_do_rgb_to_gray");
+   if (!(row_info->color_type & PNG_COLOR_MASK_PALETTE) &&
+       (row_info->color_type & PNG_COLOR_MASK_COLOR))
+   {
+      PNG_CONST png_uint_32 rc = png_ptr->rgb_to_gray_red_coeff;
+      PNG_CONST png_uint_32 gc = png_ptr->rgb_to_gray_green_coeff;
+      PNG_CONST png_uint_32 bc = 32768 - rc - gc;
+      PNG_CONST png_uint_32 row_width = row_info->width;
+      PNG_CONST int have_alpha =
+         (row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0;
+      if (row_info->bit_depth == 8)
+      {
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+         /* Notice that gamma to/from 1 are not necessarily inverses (if
+          * there is an overall gamma correction).  Prior to 1.5.5 this code
+          * checked the linearized values for equality; this doesn't match
+          * the documentation, the original values must be checked.
+          */
+         if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL)
+         {
+            png_bytep sp = row;
+            png_bytep dp = row;
+            png_uint_32 i;
+            for (i = 0; i < row_width; i++)
+            {
+               png_byte red   = *(sp++);
+               png_byte green = *(sp++);
+               png_byte blue  = *(sp++);
+               if (red != green || red != blue)
+               {
+                  red = png_ptr->gamma_to_1[red];
+                  green = png_ptr->gamma_to_1[green];
+                  blue = png_ptr->gamma_to_1[blue];
+                  rgb_error |= 1;
+                  *(dp++) = png_ptr->gamma_from_1[
+                      (rc*red + gc*green + bc*blue + 16384)>>15];
+               }
+               else
+               {
+                  /* If there is no overall correction the table will not be
+                   * set.
+                   */
+                  if (png_ptr->gamma_table != NULL)
+                     red = png_ptr->gamma_table[red];
+                  *(dp++) = red;
+               }
+               if (have_alpha)
+                  *(dp++) = *(sp++);
+            }
+         }
+         else
+#endif
+         {
+            png_bytep sp = row;
+            png_bytep dp = row;
+            png_uint_32 i;
+            for (i = 0; i < row_width; i++)
+            {
+               png_byte red   = *(sp++);
+               png_byte green = *(sp++);
+               png_byte blue  = *(sp++);
+               if (red != green || red != blue)
+               {
+                  rgb_error |= 1;
+                  /*NOTE: this is the historical approach which simply
+                   * truncates the results.
+                   */
+                  *(dp++) = (png_byte)((rc*red + gc*green + bc*blue)>>15);
+               }
+               else
+                  *(dp++) = red;
+               if (have_alpha)
+                  *(dp++) = *(sp++);
+            }
+         }
+      }
+      else /* RGB bit_depth == 16 */
+      {
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+         if (png_ptr->gamma_16_to_1 != NULL && png_ptr->gamma_16_from_1 != NULL)
+         {
+            png_bytep sp = row;
+            png_bytep dp = row;
+            png_uint_32 i;
+            for (i = 0; i < row_width; i++)
+            {
+               png_uint_16 red, green, blue, w;
+               red   = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2;
+               green = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2;
+               blue  = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2;
+               if (red == green && red == blue)
+               {
+                  if (png_ptr->gamma_16_table != NULL)
+                     w = png_ptr->gamma_16_table[(red&0xff)
+                         >> png_ptr->gamma_shift][red>>8];
+                  else
+                     w = red;
+               }
+               else
+               {
+                  png_uint_16 red_1   = png_ptr->gamma_16_to_1[(red&0xff)
+                      >> png_ptr->gamma_shift][red>>8];
+                  png_uint_16 green_1 =
+                      png_ptr->gamma_16_to_1[(green&0xff) >>
+                      png_ptr->gamma_shift][green>>8];
+                  png_uint_16 blue_1  = png_ptr->gamma_16_to_1[(blue&0xff)
+                      >> png_ptr->gamma_shift][blue>>8];
+                  png_uint_16 gray16  = (png_uint_16)((rc*red_1 + gc*green_1
+                      + bc*blue_1 + 16384)>>15);
+                  w = png_ptr->gamma_16_from_1[(gray16&0xff) >>
+                      png_ptr->gamma_shift][gray16 >> 8];
+                  rgb_error |= 1;
+               }
+               *(dp++) = (png_byte)((w>>8) & 0xff);
+               *(dp++) = (png_byte)(w & 0xff);
+               if (have_alpha)
+               {
+                  *(dp++) = *(sp++);
+                  *(dp++) = *(sp++);
+               }
+            }
+         }
+         else
+#endif
+         {
+            png_bytep sp = row;
+            png_bytep dp = row;
+            png_uint_32 i;
+            for (i = 0; i < row_width; i++)
+            {
+               png_uint_16 red, green, blue, gray16;
+               red   = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2;
+               green = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2;
+               blue  = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2;
+               if (red != green || red != blue)
+                  rgb_error |= 1;
+               /* From 1.5.5 in the 16 bit case do the accurate conversion even
+                * in the 'fast' case - this is because this is where the code
+                * ends up when handling linear 16 bit data.
+                */
+               gray16  = (png_uint_16)((rc*red + gc*green + bc*blue + 16384) >>
+                  15);
+               *(dp++) = (png_byte)((gray16>>8) & 0xff);
+               *(dp++) = (png_byte)(gray16 & 0xff);
+               if (have_alpha)
+               {
+                  *(dp++) = *(sp++);
+                  *(dp++) = *(sp++);
+               }
+            }
+         }
+      }
+      row_info->channels = (png_byte)(row_info->channels - 2);
+      row_info->color_type = (png_byte)(row_info->color_type &
+          ~PNG_COLOR_MASK_COLOR);
+      row_info->pixel_depth = (png_byte)(row_info->channels *
+          row_info->bit_depth);
+      row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
+   }
+   return rgb_error;
+}
+#endif
+#endif /* PNG_READ_TRANSFORMS_SUPPORTED */
+#ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED
+/* Build a grayscale palette.  Palette is assumed to be 1 << bit_depth
+ * large of png_color.  This lets grayscale images be treated as
+ * paletted.  Most useful for gamma correction and simplification
+ * of code.  This API is not used internally.
+ */
+void PNGAPI
+png_build_grayscale_palette(int bit_depth, png_colorp palette)
+{
+   int num_palette;
+   int color_inc;
+   int i;
+   int v;
+   png_debug(1, "in png_do_build_grayscale_palette");
+   if (palette == NULL)
+      return;
+   switch (bit_depth)
+   {
+      case 1:
+         num_palette = 2;
+         color_inc = 0xff;
+         break;
+      case 2:
+         num_palette = 4;
+         color_inc = 0x55;
+         break;
+      case 4:
+         num_palette = 16;
+         color_inc = 0x11;
+         break;
+      case 8:
+         num_palette = 256;
+         color_inc = 1;
+         break;
+      default:
+         num_palette = 0;
+         color_inc = 0;
+         break;
+   }
+   for (i = 0, v = 0; i < num_palette; i++, v += color_inc)
+   {
+      palette[i].red = (png_byte)v;
+      palette[i].green = (png_byte)v;
+      palette[i].blue = (png_byte)v;
+   }
+}
+#endif
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+#if (defined PNG_READ_BACKGROUND_SUPPORTED) ||\
+   (defined PNG_READ_ALPHA_MODE_SUPPORTED)
+/* Replace any alpha or transparency with the supplied background color.
+ * "background" is already in the screen gamma, while "background_1" is
+ * at a gamma of 1.0.  Paletted files have already been taken care of.
+ */
+void /* PRIVATE */
+png_do_compose(png_row_infop row_info, png_bytep row, png_structp png_ptr)
+{
+#ifdef PNG_READ_GAMMA_SUPPORTED
+   png_const_bytep gamma_table = png_ptr->gamma_table;
+   png_const_bytep gamma_from_1 = png_ptr->gamma_from_1;
+   png_const_bytep gamma_to_1 = png_ptr->gamma_to_1;
+   png_const_uint_16pp gamma_16 = png_ptr->gamma_16_table;
+   png_const_uint_16pp gamma_16_from_1 = png_ptr->gamma_16_from_1;
+   png_const_uint_16pp gamma_16_to_1 = png_ptr->gamma_16_to_1;
+   int gamma_shift = png_ptr->gamma_shift;
+#endif
+   png_bytep sp;
+   png_uint_32 i;
+   png_uint_32 row_width = row_info->width;
+   int optimize = (png_ptr->flags & PNG_FLAG_OPTIMIZE_ALPHA) != 0;
+   int shift;
+   png_debug(1, "in png_do_compose");
+   {
+      switch (row_info->color_type)
+      {
+         case PNG_COLOR_TYPE_GRAY:
+         {
+            switch (row_info->bit_depth)
+            {
+               case 1:
+               {
+                  sp = row;
+                  shift = 7;
+                  for (i = 0; i < row_width; i++)
+                  {
+                     if ((png_uint_16)((*sp >> shift) & 0x01)
+                        == png_ptr->trans_color.gray)
+                     {
+                        *sp &= (png_byte)((0x7f7f >> (7 - shift)) & 0xff);
+                        *sp |= (png_byte)(png_ptr->background.gray << shift);
+                     }
+                     if (!shift)
+                     {
+                        shift = 7;
+                        sp++;
+                     }
+                     else
+                        shift--;
+                  }
+                  break;
+               }
+               case 2:
+               {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+                  if (gamma_table != NULL)
+                  {
+                     sp = row;
+                     shift = 6;
+                     for (i = 0; i < row_width; i++)
+                     {
+                        if ((png_uint_16)((*sp >> shift) & 0x03)
+                            == png_ptr->trans_color.gray)
+                        {
+                           *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
+                           *sp |= (png_byte)(png_ptr->background.gray << shift);
+                        }
+                        else
+                        {
+                           png_byte p = (png_byte)((*sp >> shift) & 0x03);
+                           png_byte g = (png_byte)((gamma_table [p | (p << 2) |
+                               (p << 4) | (p << 6)] >> 6) & 0x03);
+                           *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
+                           *sp |= (png_byte)(g << shift);
+                        }
+                        if (!shift)
+                        {
+                           shift = 6;
+                           sp++;
+                        }
+                        else
+                           shift -= 2;
+                     }
+                  }
+                  else
+#endif
+                  {
+                     sp = row;
+                     shift = 6;
+                     for (i = 0; i < row_width; i++)
+                     {
+                        if ((png_uint_16)((*sp >> shift) & 0x03)
+                            == png_ptr->trans_color.gray)
+                        {
+                           *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
+                           *sp |= (png_byte)(png_ptr->background.gray << shift);
+                        }
+                        if (!shift)
+                        {
+                           shift = 6;
+                           sp++;
+                        }
+                        else
+                           shift -= 2;
+                     }
+                  }
+                  break;
+               }
+               case 4:
+               {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+                  if (gamma_table != NULL)
+                  {
+                     sp = row;
+                     shift = 4;
+                     for (i = 0; i < row_width; i++)
+                     {
+                        if ((png_uint_16)((*sp >> shift) & 0x0f)
+                            == png_ptr->trans_color.gray)
+                        {
+                           *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
+                           *sp |= (png_byte)(png_ptr->background.gray << shift);
+                        }
+                        else
+                        {
+                           png_byte p = (png_byte)((*sp >> shift) & 0x0f);
+                           png_byte g = (png_byte)((gamma_table[p |
+                               (p << 4)] >> 4) & 0x0f);
+                           *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
+                           *sp |= (png_byte)(g << shift);
+                        }
+                        if (!shift)
+                        {
+                           shift = 4;
+                           sp++;
+                        }
+                        else
+                           shift -= 4;
+                     }
+                  }
+                  else
+#endif
+                  {
+                     sp = row;
+                     shift = 4;
+                     for (i = 0; i < row_width; i++)
+                     {
+                        if ((png_uint_16)((*sp >> shift) & 0x0f)
+                            == png_ptr->trans_color.gray)
+                        {
+                           *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
+                           *sp |= (png_byte)(png_ptr->background.gray << shift);
+                        }
+                        if (!shift)
+                        {
+                           shift = 4;
+                           sp++;
+                        }
+                        else
+                           shift -= 4;
+                     }
+                  }
+                  break;
+               }
+               case 8:
+               {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+                  if (gamma_table != NULL)
+                  {
+                     sp = row;
+                     for (i = 0; i < row_width; i++, sp++)
+                     {
+                        if (*sp == png_ptr->trans_color.gray)
+                           *sp = (png_byte)png_ptr->background.gray;
+                        else
+                           *sp = gamma_table[*sp];
+                     }
+                  }
+                  else
+#endif
+                  {
+                     sp = row;
+                     for (i = 0; i < row_width; i++, sp++)
+                     {
+                        if (*sp == png_ptr->trans_color.gray)
+                           *sp = (png_byte)png_ptr->background.gray;
+                     }
+                  }
+                  break;
+               }
+               case 16:
+               {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+                  if (gamma_16 != NULL)
+                  {
+                     sp = row;
+                     for (i = 0; i < row_width; i++, sp += 2)
+                     {
+                        png_uint_16 v;
+                        v = (png_uint_16)(((*sp) << 8) + *(sp + 1));
+                        if (v == png_ptr->trans_color.gray)
+                        {
+                           /* Background is already in screen gamma */
+                           *sp = (png_byte)((png_ptr->background.gray >> 8) & 0xff);
+                           *(sp + 1) = (png_byte)(png_ptr->background.gray & 0xff);
+                        }
+                        else
+                        {
+                           v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
+                           *sp = (png_byte)((v >> 8) & 0xff);
+                           *(sp + 1) = (png_byte)(v & 0xff);
+                        }
+                     }
+                  }
+                  else
+#endif
+                  {
+                     sp = row;
+                     for (i = 0; i < row_width; i++, sp += 2)
+                     {
+                        png_uint_16 v;
+                        v = (png_uint_16)(((*sp) << 8) + *(sp + 1));
+                        if (v == png_ptr->trans_color.gray)
+                        {
+                           *sp = (png_byte)((png_ptr->background.gray >> 8) & 0xff);
+                           *(sp + 1) = (png_byte)(png_ptr->background.gray & 0xff);
+                        }
+                     }
+                  }
+                  break;
+               }
+               default:
+                  break;
+            }
+            break;
+         }
+         case PNG_COLOR_TYPE_RGB:
+         {
+            if (row_info->bit_depth == 8)
+            {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+               if (gamma_table != NULL)
+               {
+                  sp = row;
+                  for (i = 0; i < row_width; i++, sp += 3)
+                  {
+                     if (*sp == png_ptr->trans_color.red &&
+                         *(sp + 1) == png_ptr->trans_color.green &&
+                         *(sp + 2) == png_ptr->trans_color.blue)
+                     {
+                        *sp = (png_byte)png_ptr->background.red;
+                        *(sp + 1) = (png_byte)png_ptr->background.green;
+                        *(sp + 2) = (png_byte)png_ptr->background.blue;
+                     }
+                     else
+                     {
+                        *sp = gamma_table[*sp];
+                        *(sp + 1) = gamma_table[*(sp + 1)];
+                        *(sp + 2) = gamma_table[*(sp + 2)];
+                     }
+                  }
+               }
+               else
+#endif
+               {
+                  sp = row;
+                  for (i = 0; i < row_width; i++, sp += 3)
+                  {
+                     if (*sp == png_ptr->trans_color.red &&
+                         *(sp + 1) == png_ptr->trans_color.green &&
+                         *(sp + 2) == png_ptr->trans_color.blue)
+                     {
+                        *sp = (png_byte)png_ptr->background.red;
+                        *(sp + 1) = (png_byte)png_ptr->background.green;
+                        *(sp + 2) = (png_byte)png_ptr->background.blue;
+                     }
+                  }
+               }
+            }
+            else /* if (row_info->bit_depth == 16) */
+            {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+               if (gamma_16 != NULL)
+               {
+                  sp = row;
+                  for (i = 0; i < row_width; i++, sp += 6)
+                  {
+                     png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1));
+                     png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8)
+                         + *(sp + 3));
+                     png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8)
+                         + *(sp + 5));
+                     if (r == png_ptr->trans_color.red &&
+                         g == png_ptr->trans_color.green &&
+                         b == png_ptr->trans_color.blue)
+                     {
+                        /* Background is already in screen gamma */
+                        *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff);
+                        *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff);
+                        *(sp + 2) = (png_byte)((png_ptr->background.green >> 8) & 0xff);
+                        *(sp + 3) = (png_byte)(png_ptr->background.green & 0xff);
+                        *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8) & 0xff);
+                        *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff);
+                     }
+                     else
+                     {
+                        png_uint_16 v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
+                        *sp = (png_byte)((v >> 8) & 0xff);
+                        *(sp + 1) = (png_byte)(v & 0xff);
+                        v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)];
+                        *(sp + 2) = (png_byte)((v >> 8) & 0xff);
+                        *(sp + 3) = (png_byte)(v & 0xff);
+                        v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)];
+                        *(sp + 4) = (png_byte)((v >> 8) & 0xff);
+                        *(sp + 5) = (png_byte)(v & 0xff);
+                     }
+                  }
+               }
+               else
+#endif
+               {
+                  sp = row;
+                  for (i = 0; i < row_width; i++, sp += 6)
+                  {
+                     png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1));
+                     png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8)
+                         + *(sp + 3));
+                     png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8)
+                         + *(sp + 5));
+                     if (r == png_ptr->trans_color.red &&
+                         g == png_ptr->trans_color.green &&
+                         b == png_ptr->trans_color.blue)
+                     {
+                        *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff);
+                        *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff);
+                        *(sp + 2) = (png_byte)((png_ptr->background.green >> 8) & 0xff);
+                        *(sp + 3) = (png_byte)(png_ptr->background.green & 0xff);
+                        *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8) & 0xff);
+                        *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff);
+                     }
+                  }
+               }
+            }
+            break;
+         }
+         case PNG_COLOR_TYPE_GRAY_ALPHA:
+         {
+            if (row_info->bit_depth == 8)
+            {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+               if (gamma_to_1 != NULL && gamma_from_1 != NULL &&
+                   gamma_table != NULL)
+               {
+                  sp = row;
+                  for (i = 0; i < row_width; i++, sp += 2)
+                  {
+                     png_uint_16 a = *(sp + 1);
+                     if (a == 0xff)
+                        *sp = gamma_table[*sp];
+                     else if (a == 0)
+                     {
+                        /* Background is already in screen gamma */
+                        *sp = (png_byte)png_ptr->background.gray;
+                     }
+                     else
+                     {
+                        png_byte v, w;
+                        v = gamma_to_1[*sp];
+                        png_composite(w, v, a, png_ptr->background_1.gray);
+                        if (!optimize)
+                           w = gamma_from_1[w];
+                        *sp = w;
+                     }
+                  }
+               }
+               else
+#endif
+               {
+                  sp = row;
+                  for (i = 0; i < row_width; i++, sp += 2)
+                  {
+                     png_byte a = *(sp + 1);
+                     if (a == 0)
+                        *sp = (png_byte)png_ptr->background.gray;
+                     else if (a < 0xff)
+                        png_composite(*sp, *sp, a, png_ptr->background_1.gray);
+                  }
+               }
+            }
+            else /* if (png_ptr->bit_depth == 16) */
+            {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+               if (gamma_16 != NULL && gamma_16_from_1 != NULL &&
+                   gamma_16_to_1 != NULL)
+               {
+                  sp = row;
+                  for (i = 0; i < row_width; i++, sp += 4)
+                  {
+                     png_uint_16 a = (png_uint_16)(((*(sp + 2)) << 8)
+                         + *(sp + 3));
+                     if (a == (png_uint_16)0xffff)
+                     {
+                        png_uint_16 v;
+                        v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
+                        *sp = (png_byte)((v >> 8) & 0xff);
+                        *(sp + 1) = (png_byte)(v & 0xff);
+                     }
+                     else if (a == 0)
+                     {
+                        /* Background is already in screen gamma */
+                        *sp = (png_byte)((png_ptr->background.gray >> 8) & 0xff);
+                        *(sp + 1) = (png_byte)(png_ptr->background.gray & 0xff);
+                     }
+                     else
+                     {
+                        png_uint_16 g, v, w;
+                        g = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp];
+                        png_composite_16(v, g, a, png_ptr->background_1.gray);
+                        if (optimize)
+                           w = v;
+                        else
+                           w = gamma_16_from_1[(v&0xff) >> gamma_shift][v >> 8];
+                        *sp = (png_byte)((w >> 8) & 0xff);
+                        *(sp + 1) = (png_byte)(w & 0xff);
+                     }
+                  }
+               }
+               else
+#endif
+               {
+                  sp = row;
+                  for (i = 0; i < row_width; i++, sp += 4)
+                  {
+                     png_uint_16 a = (png_uint_16)(((*(sp + 2)) << 8)
+                         + *(sp + 3));
+                     if (a == 0)
+                     {
+                        *sp = (png_byte)((png_ptr->background.gray >> 8) & 0xff);
+                        *(sp + 1) = (png_byte)(png_ptr->background.gray & 0xff);
+                     }
+                     else if (a < 0xffff)
+                     {
+                        png_uint_16 g, v;
+                        g = (png_uint_16)(((*sp) << 8) + *(sp + 1));
+                        png_composite_16(v, g, a, png_ptr->background_1.gray);
+                        *sp = (png_byte)((v >> 8) & 0xff);
+                        *(sp + 1) = (png_byte)(v & 0xff);
+                     }
+                  }
+               }
+            }
+            break;
+         }
+         case PNG_COLOR_TYPE_RGB_ALPHA:
+         {
+            if (row_info->bit_depth == 8)
+            {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+               if (gamma_to_1 != NULL && gamma_from_1 != NULL &&
+                   gamma_table != NULL)
+               {
+                  sp = row;
+                  for (i = 0; i < row_width; i++, sp += 4)
+                  {
+                     png_byte a = *(sp + 3);
+                     if (a == 0xff)
+                     {
+                        *sp = gamma_table[*sp];
+                        *(sp + 1) = gamma_table[*(sp + 1)];
+                        *(sp + 2) = gamma_table[*(sp + 2)];
+                     }
+                     else if (a == 0)
+                     {
+                        /* Background is already in screen gamma */
+                        *sp = (png_byte)png_ptr->background.red;
+                        *(sp + 1) = (png_byte)png_ptr->background.green;
+                        *(sp + 2) = (png_byte)png_ptr->background.blue;
+                     }
+                     else
+                     {
+                        png_byte v, w;
+                        v = gamma_to_1[*sp];
+                        png_composite(w, v, a, png_ptr->background_1.red);
+                        if (!optimize) w = gamma_from_1[w];
+                        *sp = w;
+                        v = gamma_to_1[*(sp + 1)];
+                        png_composite(w, v, a, png_ptr->background_1.green);
+                        if (!optimize) w = gamma_from_1[w];
+                        *(sp + 1) = w;
+                        v = gamma_to_1[*(sp + 2)];
+                        png_composite(w, v, a, png_ptr->background_1.blue);
+                        if (!optimize) w = gamma_from_1[w];
+                        *(sp + 2) = w;
+                     }
+                  }
+               }
+               else
+#endif
+               {
+                  sp = row;
+                  for (i = 0; i < row_width; i++, sp += 4)
+                  {
+                     png_byte a = *(sp + 3);
+                     if (a == 0)
+                     {
+                        *sp = (png_byte)png_ptr->background.red;
+                        *(sp + 1) = (png_byte)png_ptr->background.green;
+                        *(sp + 2) = (png_byte)png_ptr->background.blue;
+                     }
+                     else if (a < 0xff)
+                     {
+                        png_composite(*sp, *sp, a, png_ptr->background.red);
+                        png_composite(*(sp + 1), *(sp + 1), a,
+                            png_ptr->background.green);
+                        png_composite(*(sp + 2), *(sp + 2), a,
+                            png_ptr->background.blue);
+                     }
+                  }
+               }
+            }
+            else /* if (row_info->bit_depth == 16) */
+            {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+               if (gamma_16 != NULL && gamma_16_from_1 != NULL &&
+                   gamma_16_to_1 != NULL)
+               {
+                  sp = row;
+                  for (i = 0; i < row_width; i++, sp += 8)
+                  {
+                     png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6))
+                         << 8) + (png_uint_16)(*(sp + 7)));
+                     if (a == (png_uint_16)0xffff)
+                     {
+                        png_uint_16 v;
+                        v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
+                        *sp = (png_byte)((v >> 8) & 0xff);
+                        *(sp + 1) = (png_byte)(v & 0xff);
+                        v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)];
+                        *(sp + 2) = (png_byte)((v >> 8) & 0xff);
+                        *(sp + 3) = (png_byte)(v & 0xff);
+                        v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)];
+                        *(sp + 4) = (png_byte)((v >> 8) & 0xff);
+                        *(sp + 5) = (png_byte)(v & 0xff);
+                     }
+                     else if (a == 0)
+                     {
+                        /* Background is already in screen gamma */
+                        *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff);
+                        *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff);
+                        *(sp + 2) = (png_byte)((png_ptr->background.green >> 8) & 0xff);
+                        *(sp + 3) = (png_byte)(png_ptr->background.green & 0xff);
+                        *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8) & 0xff);
+                        *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff);
+                     }
+                     else
+                     {
+                        png_uint_16 v, w;
+                        v = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp];
+                        png_composite_16(w, v, a, png_ptr->background_1.red);
+                        if (!optimize)
+                           w = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8];
+                        *sp = (png_byte)((w >> 8) & 0xff);
+                        *(sp + 1) = (png_byte)(w & 0xff);
+                        v = gamma_16_to_1[*(sp + 3) >> gamma_shift][*(sp + 2)];
+                        png_composite_16(w, v, a, png_ptr->background_1.green);
+                        if (!optimize)
+                           w = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8];
+                        *(sp + 2) = (png_byte)((w >> 8) & 0xff);
+                        *(sp + 3) = (png_byte)(w & 0xff);
+                        v = gamma_16_to_1[*(sp + 5) >> gamma_shift][*(sp + 4)];
+                        png_composite_16(w, v, a, png_ptr->background_1.blue);
+                        if (!optimize)
+                           w = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8];
+                        *(sp + 4) = (png_byte)((w >> 8) & 0xff);
+                        *(sp + 5) = (png_byte)(w & 0xff);
+                     }
+                  }
+               }
+               else
+#endif
+               {
+                  sp = row;
+                  for (i = 0; i < row_width; i++, sp += 8)
+                  {
+                     png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6))
+                         << 8) + (png_uint_16)(*(sp + 7)));
+                     if (a == 0)
+                     {
+                        *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff);
+                        *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff);
+                        *(sp + 2) = (png_byte)((png_ptr->background.green >> 8) & 0xff);
+                        *(sp + 3) = (png_byte)(png_ptr->background.green & 0xff);
+                        *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8) & 0xff);
+                        *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff);
+                     }
+                     else if (a < 0xffff)
+                     {
+                        png_uint_16 v;
+                        png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1));
+                        png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8)
+                            + *(sp + 3));
+                        png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8)
+                            + *(sp + 5));
+                        png_composite_16(v, r, a, png_ptr->background.red);
+                        *sp = (png_byte)((v >> 8) & 0xff);
+                        *(sp + 1) = (png_byte)(v & 0xff);
+                        png_composite_16(v, g, a, png_ptr->background.green);
+                        *(sp + 2) = (png_byte)((v >> 8) & 0xff);
+                        *(sp + 3) = (png_byte)(v & 0xff);
+                        png_composite_16(v, b, a, png_ptr->background.blue);
+                        *(sp + 4) = (png_byte)((v >> 8) & 0xff);
+                        *(sp + 5) = (png_byte)(v & 0xff);
+                     }
+                  }
+               }
+            }
+            break;
+         }
+         default:
+            break;
+      }
+   }
+}
+#endif /* PNG_READ_BACKGROUND_SUPPORTED || PNG_READ_ALPHA_MODE_SUPPORTED */
+#ifdef PNG_READ_GAMMA_SUPPORTED
+/* Gamma correct the image, avoiding the alpha channel.  Make sure
+ * you do this after you deal with the transparency issue on grayscale
+ * or RGB images. If your bit depth is 8, use gamma_table, if it
+ * is 16, use gamma_16_table and gamma_shift.  Build these with
+ * build_gamma_table().
+ */
+void /* PRIVATE */
+png_do_gamma(png_row_infop row_info, png_bytep row, png_structp png_ptr)
+{
+   png_const_bytep gamma_table = png_ptr->gamma_table;
+   png_const_uint_16pp gamma_16_table = png_ptr->gamma_16_table;
+   int gamma_shift = png_ptr->gamma_shift;
+   png_bytep sp;
+   png_uint_32 i;
+   png_uint_32 row_width=row_info->width;
+   png_debug(1, "in png_do_gamma");
+   if (((row_info->bit_depth <= 8 && gamma_table != NULL) ||
+       (row_info->bit_depth == 16 && gamma_16_table != NULL)))
+   {
+      switch (row_info->color_type)
+      {
+         case PNG_COLOR_TYPE_RGB:
+         {
+            if (row_info->bit_depth == 8)
+            {
+               sp = row;
+               for (i = 0; i < row_width; i++)
+               {
+                  *sp = gamma_table[*sp];
+                  sp++;
+                  *sp = gamma_table[*sp];
+                  sp++;
+                  *sp = gamma_table[*sp];
+                  sp++;
+               }
+            }
+            else /* if (row_info->bit_depth == 16) */
+            {
+               sp = row;
+               for (i = 0; i < row_width; i++)
+               {
+                  png_uint_16 v;
+                  v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+                  *sp = (png_byte)((v >> 8) & 0xff);
+                  *(sp + 1) = (png_byte)(v & 0xff);
+                  sp += 2;
+                  v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+                  *sp = (png_byte)((v >> 8) & 0xff);
+                  *(sp + 1) = (png_byte)(v & 0xff);
+                  sp += 2;
+                  v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+                  *sp = (png_byte)((v >> 8) & 0xff);
+                  *(sp + 1) = (png_byte)(v & 0xff);
+                  sp += 2;
+               }
+            }
+            break;
+         }
+         case PNG_COLOR_TYPE_RGB_ALPHA:
+         {
+            if (row_info->bit_depth == 8)
+            {
+               sp = row;
+               for (i = 0; i < row_width; i++)
+               {
+                  *sp = gamma_table[*sp];
+                  sp++;
+                  *sp = gamma_table[*sp];
+                  sp++;
+                  *sp = gamma_table[*sp];
+                  sp++;
+                  sp++;
+               }
+            }
+            else /* if (row_info->bit_depth == 16) */
+            {
+               sp = row;
+               for (i = 0; i < row_width; i++)
+               {
+                  png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+                  *sp = (png_byte)((v >> 8) & 0xff);
+                  *(sp + 1) = (png_byte)(v & 0xff);
+                  sp += 2;
+                  v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+                  *sp = (png_byte)((v >> 8) & 0xff);
+                  *(sp + 1) = (png_byte)(v & 0xff);
+                  sp += 2;
+                  v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+                  *sp = (png_byte)((v >> 8) & 0xff);
+                  *(sp + 1) = (png_byte)(v & 0xff);
+                  sp += 4;
+               }
+            }
+            break;
+         }
+         case PNG_COLOR_TYPE_GRAY_ALPHA:
+         {
+            if (row_info->bit_depth == 8)
+            {
+               sp = row;
+               for (i = 0; i < row_width; i++)
+               {
+                  *sp = gamma_table[*sp];
+                  sp += 2;
+               }
+            }
+            else /* if (row_info->bit_depth == 16) */
+            {
+               sp = row;
+               for (i = 0; i < row_width; i++)
+               {
+                  png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+                  *sp = (png_byte)((v >> 8) & 0xff);
+                  *(sp + 1) = (png_byte)(v & 0xff);
+                  sp += 4;
+               }
+            }
+            break;
+         }
+         case PNG_COLOR_TYPE_GRAY:
+         {
+            if (row_info->bit_depth == 2)
+            {
+               sp = row;
+               for (i = 0; i < row_width; i += 4)
+               {
+                  int a = *sp & 0xc0;
+                  int b = *sp & 0x30;
+                  int c = *sp & 0x0c;
+                  int d = *sp & 0x03;
+                  *sp = (png_byte)(
+                      ((((int)gamma_table[a|(a>>2)|(a>>4)|(a>>6)])   ) & 0xc0)|
+                      ((((int)gamma_table[(b<<2)|b|(b>>2)|(b>>4)])>>2) & 0x30)|
+                      ((((int)gamma_table[(c<<4)|(c<<2)|c|(c>>2)])>>4) & 0x0c)|
+                      ((((int)gamma_table[(d<<6)|(d<<4)|(d<<2)|d])>>6) ));
+                  sp++;
+               }
+            }
+            if (row_info->bit_depth == 4)
+            {
+               sp = row;
+               for (i = 0; i < row_width; i += 2)
+               {
+                  int msb = *sp & 0xf0;
+                  int lsb = *sp & 0x0f;
+                  *sp = (png_byte)((((int)gamma_table[msb | (msb >> 4)]) & 0xf0)
+                      | (((int)gamma_table[(lsb << 4) | lsb]) >> 4));
+                  sp++;
+               }
+            }
+            else if (row_info->bit_depth == 8)
+            {
+               sp = row;
+               for (i = 0; i < row_width; i++)
+               {
+                  *sp = gamma_table[*sp];
+                  sp++;
+               }
+            }
+            else if (row_info->bit_depth == 16)
+            {
+               sp = row;
+               for (i = 0; i < row_width; i++)
+               {
+                  png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+                  *sp = (png_byte)((v >> 8) & 0xff);
+                  *(sp + 1) = (png_byte)(v & 0xff);
+                  sp += 2;
+               }
+            }
+            break;
+         }
+         default:
+            break;
+      }
+   }
+}
+#endif
+#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+/* Encode the alpha channel to the output gamma (the input channel is always
+ * linear.)  Called only with color types that have an alpha channel.  Needs the
+ * from_1 tables.
+ */
+void /* PRIVATE */
+png_do_encode_alpha(png_row_infop row_info, png_bytep row, png_structp png_ptr)
+{
+   png_uint_32 row_width = row_info->width;
+   png_debug(1, "in png_do_encode_alpha");
+   if (row_info->color_type & PNG_COLOR_MASK_ALPHA)
+   {
+      if (row_info->bit_depth == 8)
+      {
+         PNG_CONST png_bytep table = png_ptr->gamma_from_1;
+         if (table != NULL)
+         {
+            PNG_CONST int step =
+               (row_info->color_type & PNG_COLOR_MASK_COLOR) ? 4 : 2;
+            /* The alpha channel is the last component: */
+            row += step - 1;
+            for (; row_width > 0; --row_width, row += step)
+               *row = table[*row];
+            return;
+         }
+      }
+      else if (row_info->bit_depth == 16)
+      {
+         PNG_CONST png_uint_16pp table = png_ptr->gamma_16_from_1;
+         PNG_CONST int gamma_shift = png_ptr->gamma_shift;
+         if (table != NULL)
+         {
+            PNG_CONST int step =
+               (row_info->color_type & PNG_COLOR_MASK_COLOR) ? 8 : 4;
+            /* The alpha channel is the last component: */
+            row += step - 2;
+            for (; row_width > 0; --row_width, row += step)
+            {
+               png_uint_16 v;
+               v = table[*(row + 1) >> gamma_shift][*row];
+               *row = (png_byte)((v >> 8) & 0xff);
+               *(row + 1) = (png_byte)(v & 0xff);
+            }
+            return;
+         }
+      }
+   }
+   /* Only get to here if called with a weird row_info; no harm has been done,
+    * so just issue a warning.
+    */
+   png_warning(png_ptr, "png_do_encode_alpha: unexpected call");
+}
+#endif
+#ifdef PNG_READ_EXPAND_SUPPORTED
+/* Expands a palette row to an RGB or RGBA row depending
+ * upon whether you supply trans and num_trans.
+ */
+void /* PRIVATE */
+png_do_expand_palette(png_row_infop row_info, png_bytep row,
+   png_const_colorp palette, png_const_bytep trans_alpha, int num_trans)
+{
+   int shift, value;
+   png_bytep sp, dp;
+   png_uint_32 i;
+   png_uint_32 row_width=row_info->width;
+   png_debug(1, "in png_do_expand_palette");
+   if (row_info->color_type == PNG_COLOR_TYPE_PALETTE)
+   {
+      if (row_info->bit_depth < 8)
+      {
+         switch (row_info->bit_depth)
+         {
+            case 1:
+            {
+               sp = row + (png_size_t)((row_width - 1) >> 3);
+               dp = row + (png_size_t)row_width - 1;
+               shift = 7 - (int)((row_width + 7) & 0x07);
+               for (i = 0; i < row_width; i++)
+               {
+                  if ((*sp >> shift) & 0x01)
+                     *dp = 1;
+                  else
+                     *dp = 0;
+                  if (shift == 7)
+                  {
+                     shift = 0;
+                     sp--;
+                  }
+                  else
+                     shift++;
+                  dp--;
+               }
+               break;
+            }
+            case 2:
+            {
+               sp = row + (png_size_t)((row_width - 1) >> 2);
+               dp = row + (png_size_t)row_width - 1;
+               shift = (int)((3 - ((row_width + 3) & 0x03)) << 1);
+               for (i = 0; i < row_width; i++)
+               {
+                  value = (*sp >> shift) & 0x03;
+                  *dp = (png_byte)value;
+                  if (shift == 6)
+                  {
+                     shift = 0;
+                     sp--;
+                  }
+                  else
+                     shift += 2;
+                  dp--;
+               }
+               break;
+            }
+            case 4:
+            {
+               sp = row + (png_size_t)((row_width - 1) >> 1);
+               dp = row + (png_size_t)row_width - 1;
+               shift = (int)((row_width & 0x01) << 2);
+               for (i = 0; i < row_width; i++)
+               {
+                  value = (*sp >> shift) & 0x0f;
+                  *dp = (png_byte)value;
+                  if (shift == 4)
+                  {
+                     shift = 0;
+                     sp--;
+                  }
+                  else
+                     shift += 4;
+                  dp--;
+               }
+               break;
+            }
+            default:
+               break;
+         }
+         row_info->bit_depth = 8;
+         row_info->pixel_depth = 8;
+         row_info->rowbytes = row_width;
+      }
+      if (row_info->bit_depth == 8)
+      {
+         {
+            if (num_trans > 0)
+            {
+               sp = row + (png_size_t)row_width - 1;
+               dp = row + (png_size_t)(row_width << 2) - 1;
+               for (i = 0; i < row_width; i++)
+               {
+                  if ((int)(*sp) >= num_trans)
+                     *dp-- = 0xff;
+                  else
+                     *dp-- = trans_alpha[*sp];
+                  *dp-- = palette[*sp].blue;
+                  *dp-- = palette[*sp].green;
+                  *dp-- = palette[*sp].red;
+                  sp--;
+               }
+               row_info->bit_depth = 8;
+               row_info->pixel_depth = 32;
+               row_info->rowbytes = row_width * 4;
+               row_info->color_type = 6;
+               row_info->channels = 4;
+            }
+            else
+            {
+               sp = row + (png_size_t)row_width - 1;
+               dp = row + (png_size_t)(row_width * 3) - 1;
+               for (i = 0; i < row_width; i++)
+               {
+                  *dp-- = palette[*sp].blue;
+                  *dp-- = palette[*sp].green;
+                  *dp-- = palette[*sp].red;
+                  sp--;
+               }
+               row_info->bit_depth = 8;
+               row_info->pixel_depth = 24;
+               row_info->rowbytes = row_width * 3;
+               row_info->color_type = 2;
+               row_info->channels = 3;
+            }
+         }
+      }
+   }
+}
+/* If the bit depth < 8, it is expanded to 8.  Also, if the already
+ * expanded transparency value is supplied, an alpha channel is built.
+ */
+void /* PRIVATE */
+png_do_expand(png_row_infop row_info, png_bytep row,
+    png_const_color_16p trans_color)
+{
+   int shift, value;
+   png_bytep sp, dp;
+   png_uint_32 i;
+   png_uint_32 row_width=row_info->width;
+   png_debug(1, "in png_do_expand");
+   {
+      if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
+      {
+         png_uint_16 gray = (png_uint_16)(trans_color ? trans_color->gray : 0);
+         if (row_info->bit_depth < 8)
+         {
+            switch (row_info->bit_depth)
+            {
+               case 1:
+               {
+                  gray = (png_uint_16)((gray & 0x01) * 0xff);
+                  sp = row + (png_size_t)((row_width - 1) >> 3);
+                  dp = row + (png_size_t)row_width - 1;
+                  shift = 7 - (int)((row_width + 7) & 0x07);
+                  for (i = 0; i < row_width; i++)
+                  {
+                     if ((*sp >> shift) & 0x01)
+                        *dp = 0xff;
+                     else
+                        *dp = 0;
+                     if (shift == 7)
+                     {
+                        shift = 0;
+                        sp--;
+                     }
+                     else
+                        shift++;
+                     dp--;
+                  }
+                  break;
+               }
+               case 2:
+               {
+                  gray = (png_uint_16)((gray & 0x03) * 0x55);
+                  sp = row + (png_size_t)((row_width - 1) >> 2);
+                  dp = row + (png_size_t)row_width - 1;
+                  shift = (int)((3 - ((row_width + 3) & 0x03)) << 1);
+                  for (i = 0; i < row_width; i++)
+                  {
+                     value = (*sp >> shift) & 0x03;
+                     *dp = (png_byte)(value | (value << 2) | (value << 4) |
+                        (value << 6));
+                     if (shift == 6)
+                     {
+                        shift = 0;
+                        sp--;
+                     }
+                     else
+                        shift += 2;
+                     dp--;
+                  }
+                  break;
+               }
+               case 4:
+               {
+                  gray = (png_uint_16)((gray & 0x0f) * 0x11);
+                  sp = row + (png_size_t)((row_width - 1) >> 1);
+                  dp = row + (png_size_t)row_width - 1;
+                  shift = (int)((1 - ((row_width + 1) & 0x01)) << 2);
+                  for (i = 0; i < row_width; i++)
+                  {
+                     value = (*sp >> shift) & 0x0f;
+                     *dp = (png_byte)(value | (value << 4));
+                     if (shift == 4)
+                     {
+                        shift = 0;
+                        sp--;
+                     }
+                     else
+                        shift = 4;
+                     dp--;
+                  }
+                  break;
+               }
+               default:
+                  break;
+            }
+            row_info->bit_depth = 8;
+            row_info->pixel_depth = 8;
+            row_info->rowbytes = row_width;
+         }
+         if (trans_color != NULL)
+         {
+            if (row_info->bit_depth == 8)
+            {
+               gray = gray & 0xff;
+               sp = row + (png_size_t)row_width - 1;
+               dp = row + (png_size_t)(row_width << 1) - 1;
+               for (i = 0; i < row_width; i++)
+               {
+                  if (*sp == gray)
+                     *dp-- = 0;
+                  else
+                     *dp-- = 0xff;
+                  *dp-- = *sp--;
+               }
+            }
+            else if (row_info->bit_depth == 16)
+            {
+               png_byte gray_high = (png_byte)((gray >> 8) & 0xff);
+               png_byte gray_low = (png_byte)(gray & 0xff);
+               sp = row + row_info->rowbytes - 1;
+               dp = row + (row_info->rowbytes << 1) - 1;
+               for (i = 0; i < row_width; i++)
+               {
+                  if (*(sp - 1) == gray_high && *(sp) == gray_low)
+                  {
+                     *dp-- = 0;
+                     *dp-- = 0;
+                  }
+                  else
+                  {
+                     *dp-- = 0xff;
+                     *dp-- = 0xff;
+                  }
+                  *dp-- = *sp--;
+                  *dp-- = *sp--;
+               }
+            }
+            row_info->color_type = PNG_COLOR_TYPE_GRAY_ALPHA;
+            row_info->channels = 2;
+            row_info->pixel_depth = (png_byte)(row_info->bit_depth << 1);
+            row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
+               row_width);
+         }
+      }
+      else if (row_info->color_type == PNG_COLOR_TYPE_RGB && trans_color)
+      {
+         if (row_info->bit_depth == 8)
+         {
+            png_byte red = (png_byte)(trans_color->red & 0xff);
+            png_byte green = (png_byte)(trans_color->green & 0xff);
+            png_byte blue = (png_byte)(trans_color->blue & 0xff);
+            sp = row + (png_size_t)row_info->rowbytes - 1;
+            dp = row + (png_size_t)(row_width << 2) - 1;
+            for (i = 0; i < row_width; i++)
+            {
+               if (*(sp - 2) == red && *(sp - 1) == green && *(sp) == blue)
+                  *dp-- = 0;
+               else
+                  *dp-- = 0xff;
+               *dp-- = *sp--;
+               *dp-- = *sp--;
+               *dp-- = *sp--;
+            }
+         }
+         else if (row_info->bit_depth == 16)
+         {
+            png_byte red_high = (png_byte)((trans_color->red >> 8) & 0xff);
+            png_byte green_high = (png_byte)((trans_color->green >> 8) & 0xff);
+            png_byte blue_high = (png_byte)((trans_color->blue >> 8) & 0xff);
+            png_byte red_low = (png_byte)(trans_color->red & 0xff);
+            png_byte green_low = (png_byte)(trans_color->green & 0xff);
+            png_byte blue_low = (png_byte)(trans_color->blue & 0xff);
+            sp = row + row_info->rowbytes - 1;
+            dp = row + (png_size_t)(row_width << 3) - 1;
+            for (i = 0; i < row_width; i++)
+            {
+               if (*(sp - 5) == red_high &&
+                   *(sp - 4) == red_low &&
+                   *(sp - 3) == green_high &&
+                   *(sp - 2) == green_low &&
+                   *(sp - 1) == blue_high &&
+                   *(sp    ) == blue_low)
+               {
+                  *dp-- = 0;
+                  *dp-- = 0;
+               }
+               else
+               {
+                  *dp-- = 0xff;
+                  *dp-- = 0xff;
+               }
+               *dp-- = *sp--;
+               *dp-- = *sp--;
+               *dp-- = *sp--;
+               *dp-- = *sp--;
+               *dp-- = *sp--;
+               *dp-- = *sp--;
+            }
+         }
+         row_info->color_type = PNG_COLOR_TYPE_RGB_ALPHA;
+         row_info->channels = 4;
+         row_info->pixel_depth = (png_byte)(row_info->bit_depth << 2);
+         row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
+      }
+   }
+}
+#endif
+#ifdef PNG_READ_EXPAND_16_SUPPORTED
+/* If the bit depth is 8 and the color type is not a palette type expand the
+ * whole row to 16 bits.  Has no effect otherwise.
+ */
+void /* PRIVATE */
+png_do_expand_16(png_row_infop row_info, png_bytep row)
+{
+   if (row_info->bit_depth == 8 &&
+      row_info->color_type != PNG_COLOR_TYPE_PALETTE)
+   {
+      /* The row have a sequence of bytes containing [0..255] and we need
+       * to turn it into another row containing [0..65535], to do this we
+       * calculate:
+       *
+       *  (input / 255) * 65535
+       *
+       *  Which happens to be exactly input * 257 and this can be achieved
+       *  simply by byte replication in place (copying backwards).
+       */
+      png_byte *sp = row + row_info->rowbytes; /* source, last byte + 1 */
+      png_byte *dp = sp + row_info->rowbytes;  /* destination, end + 1 */
+      while (dp > sp)
+         dp[-2] = dp[-1] = *--sp, dp -= 2;
+      row_info->rowbytes *= 2;
+      row_info->bit_depth = 16;
+      row_info->pixel_depth = (png_byte)(row_info->channels * 16);
+   }
+}
+#endif
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+void /* PRIVATE */
+png_do_quantize(png_row_infop row_info, png_bytep row,
+    png_const_bytep palette_lookup, png_const_bytep quantize_lookup)
+{
+   png_bytep sp, dp;
+   png_uint_32 i;
+   png_uint_32 row_width=row_info->width;
+   png_debug(1, "in png_do_quantize");
+   if (row_info->bit_depth == 8)
+   {
+      if (row_info->color_type == PNG_COLOR_TYPE_RGB && palette_lookup)
+      {
+         int r, g, b, p;
+         sp = row;
+         dp = row;
+         for (i = 0; i < row_width; i++)
+         {
+            r = *sp++;
+            g = *sp++;
+            b = *sp++;
+            /* This looks real messy, but the compiler will reduce
+             * it down to a reasonable formula.  For example, with
+             * 5 bits per color, we get:
+             * p = (((r >> 3) & 0x1f) << 10) |
+             *    (((g >> 3) & 0x1f) << 5) |
+             *    ((b >> 3) & 0x1f);
+             */
+            p = (((r >> (8 - PNG_QUANTIZE_RED_BITS)) &
+                ((1 << PNG_QUANTIZE_RED_BITS) - 1)) <<
+                (PNG_QUANTIZE_GREEN_BITS + PNG_QUANTIZE_BLUE_BITS)) |
+                (((g >> (8 - PNG_QUANTIZE_GREEN_BITS)) &
+                ((1 << PNG_QUANTIZE_GREEN_BITS) - 1)) <<
+                (PNG_QUANTIZE_BLUE_BITS)) |
+                ((b >> (8 - PNG_QUANTIZE_BLUE_BITS)) &
+                ((1 << PNG_QUANTIZE_BLUE_BITS) - 1));
+            *dp++ = palette_lookup[p];
+         }
+         row_info->color_type = PNG_COLOR_TYPE_PALETTE;
+         row_info->channels = 1;
+         row_info->pixel_depth = row_info->bit_depth;
+         row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
+      }
+      else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA &&
+         palette_lookup != NULL)
+      {
+         int r, g, b, p;
+         sp = row;
+         dp = row;
+         for (i = 0; i < row_width; i++)
+         {
+            r = *sp++;
+            g = *sp++;
+            b = *sp++;
+            sp++;
+            p = (((r >> (8 - PNG_QUANTIZE_RED_BITS)) &
+                ((1 << PNG_QUANTIZE_RED_BITS) - 1)) <<
+                (PNG_QUANTIZE_GREEN_BITS + PNG_QUANTIZE_BLUE_BITS)) |
+                (((g >> (8 - PNG_QUANTIZE_GREEN_BITS)) &
+                ((1 << PNG_QUANTIZE_GREEN_BITS) - 1)) <<
+                (PNG_QUANTIZE_BLUE_BITS)) |
+                ((b >> (8 - PNG_QUANTIZE_BLUE_BITS)) &
+                ((1 << PNG_QUANTIZE_BLUE_BITS) - 1));
+            *dp++ = palette_lookup[p];
+         }
+         row_info->color_type = PNG_COLOR_TYPE_PALETTE;
+         row_info->channels = 1;
+         row_info->pixel_depth = row_info->bit_depth;
+         row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
+      }
+      else if (row_info->color_type == PNG_COLOR_TYPE_PALETTE &&
+         quantize_lookup)
+      {
+         sp = row;
+         for (i = 0; i < row_width; i++, sp++)
+         {
+            *sp = quantize_lookup[*sp];
+         }
+      }
+   }
+}
+#endif /* PNG_READ_QUANTIZE_SUPPORTED */
+#endif /* PNG_READ_TRANSFORMS_SUPPORTED */
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+/* Undoes intrapixel differencing  */
+void /* PRIVATE */
+png_do_read_intrapixel(png_row_infop row_info, png_bytep row)
+{
+   png_debug(1, "in png_do_read_intrapixel");
+   if (
+       (row_info->color_type & PNG_COLOR_MASK_COLOR))
+   {
+      int bytes_per_pixel;
+      png_uint_32 row_width = row_info->width;
+      if (row_info->bit_depth == 8)
+      {
+         png_bytep rp;
+         png_uint_32 i;
+         if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+            bytes_per_pixel = 3;
+         else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+            bytes_per_pixel = 4;
+         else
+            return;
+         for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
+         {
+            *(rp) = (png_byte)((256 + *rp + *(rp + 1)) & 0xff);
+            *(rp+2) = (png_byte)((256 + *(rp + 2) + *(rp + 1)) & 0xff);
+         }
+      }
+      else if (row_info->bit_depth == 16)
+      {
+         png_bytep rp;
+         png_uint_32 i;
+         if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+            bytes_per_pixel = 6;
+         else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+            bytes_per_pixel = 8;
+         else
+            return;
+         for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
+         {
+            png_uint_32 s0   = (*(rp    ) << 8) | *(rp + 1);
+            png_uint_32 s1   = (*(rp + 2) << 8) | *(rp + 3);
+            png_uint_32 s2   = (*(rp + 4) << 8) | *(rp + 5);
+            png_uint_32 red  = (s0 + s1 + 65536) & 0xffff;
+            png_uint_32 blue = (s2 + s1 + 65536) & 0xffff;
+            *(rp    ) = (png_byte)((red >> 8) & 0xff);
+            *(rp + 1) = (png_byte)(red & 0xff);
+            *(rp + 4) = (png_byte)((blue >> 8) & 0xff);
+            *(rp + 5) = (png_byte)(blue & 0xff);
+         }
+      }
+   }
+}
+#endif /* PNG_MNG_FEATURES_SUPPORTED */
+#endif /* PNG_READ_SUPPORTED */
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngrutil.c b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngrutil.c
new file mode 100644
index 0000000..7b4557f
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngrutil.c
@@ -0,0 +1,4158 @@
+/* pngrutil.c - utilities to read a PNG file
+ *
+ * Last changed in libpng 1.5.9 [February 18, 2012]
+ * Copyright (c) 1998-2012 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * This file contains routines that are only called from within
+ * libpng itself during the course of reading an image.
+ */
+#include "pngpriv.h"
+#ifdef PNG_READ_SUPPORTED
+#define png_strtod(p,a,b) strtod(a,b)
+png_uint_32 PNGAPI
+png_get_uint_31(png_structp png_ptr, png_const_bytep buf)
+{
+   png_uint_32 uval = png_get_uint_32(buf);
+   if (uval > PNG_UINT_31_MAX)
+      png_error(png_ptr, "PNG unsigned integer out of range");
+   return (uval);
+}
+#if defined(PNG_READ_gAMA_SUPPORTED) || defined(PNG_READ_cHRM_SUPPORTED)
+/* The following is a variation on the above for use with the fixed
+ * point values used for gAMA and cHRM.  Instead of png_error it
+ * issues a warning and returns (-1) - an invalid value because both
+ * gAMA and cHRM use *unsigned* integers for fixed point values.
+ */
+#define PNG_FIXED_ERROR (-1)
+static png_fixed_point /* PRIVATE */
+png_get_fixed_point(png_structp png_ptr, png_const_bytep buf)
+{
+   png_uint_32 uval = png_get_uint_32(buf);
+   if (uval <= PNG_UINT_31_MAX)
+      return (png_fixed_point)uval; /* known to be in range */
+   /* The caller can turn off the warning by passing NULL. */
+   if (png_ptr != NULL)
+      png_warning(png_ptr, "PNG fixed point integer out of range");
+   return PNG_FIXED_ERROR;
+}
+#endif
+#ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED
+/* NOTE: the read macros will obscure these definitions, so that if
+ * PNG_USE_READ_MACROS is set the library will not use them internally,
+ * but the APIs will still be available externally.
+ *
+ * The parentheses around "PNGAPI function_name" in the following three
+ * functions are necessary because they allow the macros to co-exist with
+ * these (unused but exported) functions.
+ */
+/* Grab an unsigned 32-bit integer from a buffer in big-endian format. */
+png_uint_32 (PNGAPI
+png_get_uint_32)(png_const_bytep buf)
+{
+   png_uint_32 uval =
+       ((png_uint_32)(*(buf    )) << 24) +
+       ((png_uint_32)(*(buf + 1)) << 16) +
+       ((png_uint_32)(*(buf + 2)) <<  8) +
+       ((png_uint_32)(*(buf + 3))      ) ;
+   return uval;
+}
+/* Grab a signed 32-bit integer from a buffer in big-endian format.  The
+ * data is stored in the PNG file in two's complement format and there
+ * is no guarantee that a 'png_int_32' is exactly 32 bits, therefore
+ * the following code does a two's complement to native conversion.
+ */
+png_int_32 (PNGAPI
+png_get_int_32)(png_const_bytep buf)
+{
+   png_uint_32 uval = png_get_uint_32(buf);
+   if ((uval & 0x80000000) == 0) /* non-negative */
+      return uval;
+   uval = (uval ^ 0xffffffff) + 1;  /* 2's complement: -x = ~x+1 */
+   return -(png_int_32)uval;
+}
+/* Grab an unsigned 16-bit integer from a buffer in big-endian format. */
+png_uint_16 (PNGAPI
+png_get_uint_16)(png_const_bytep buf)
+{
+   /* ANSI-C requires an int value to accomodate at least 16 bits so this
+    * works and allows the compiler not to worry about possible narrowing
+    * on 32 bit systems.  (Pre-ANSI systems did not make integers smaller
+    * than 16 bits either.)
+    */
+   unsigned int val =
+       ((unsigned int)(*buf) << 8) +
+       ((unsigned int)(*(buf + 1)));
+   return (png_uint_16)val;
+}
+#endif /* PNG_READ_INT_FUNCTIONS_SUPPORTED */
+/* Read and check the PNG file signature */
+void /* PRIVATE */
+png_read_sig(png_structp png_ptr, png_infop info_ptr)
+{
+   png_size_t num_checked, num_to_check;
+   /* Exit if the user application does not expect a signature. */
+   if (png_ptr->sig_bytes >= 8)
+      return;
+   num_checked = png_ptr->sig_bytes;
+   num_to_check = 8 - num_checked;
+#ifdef PNG_IO_STATE_SUPPORTED
+   png_ptr->io_state = PNG_IO_READING | PNG_IO_SIGNATURE;
+#endif
+   /* The signature must be serialized in a single I/O call. */
+   png_read_data(png_ptr, &(info_ptr->signature[num_checked]), num_to_check);
+   png_ptr->sig_bytes = 8;
+   if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check))
+   {
+      if (num_checked < 4 &&
+          png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4))
+         png_error(png_ptr, "Not a PNG file");
+      else
+         png_error(png_ptr, "PNG file corrupted by ASCII conversion");
+   }
+   if (num_checked < 3)
+      png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
+}
+/* Read the chunk header (length + type name).
+ * Put the type name into png_ptr->chunk_name, and return the length.
+ */
+png_uint_32 /* PRIVATE */
+png_read_chunk_header(png_structp png_ptr)
+{
+   png_byte buf[8];
+   png_uint_32 length;
+#ifdef PNG_IO_STATE_SUPPORTED
+   png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_HDR;
+#endif
+   /* Read the length and the chunk name.
+    * This must be performed in a single I/O call.
+    */
+   png_read_data(png_ptr, buf, 8);
+   length = png_get_uint_31(png_ptr, buf);
+   /* Put the chunk name into png_ptr->chunk_name. */
+   png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(buf+4);
+   png_debug2(0, "Reading %lx chunk, length = %lu",
+       (unsigned long)png_ptr->chunk_name, (unsigned long)length);
+   /* Reset the crc and run it over the chunk name. */
+   png_reset_crc(png_ptr);
+   png_calculate_crc(png_ptr, buf + 4, 4);
+   /* Check to see if chunk name is valid. */
+   png_check_chunk_name(png_ptr, png_ptr->chunk_name);
+#ifdef PNG_IO_STATE_SUPPORTED
+   png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_DATA;
+#endif
+   return length;
+}
+/* Read data, and (optionally) run it through the CRC. */
+void /* PRIVATE */
+png_crc_read(png_structp png_ptr, png_bytep buf, png_size_t length)
+{
+   if (png_ptr == NULL)
+      return;
+   png_read_data(png_ptr, buf, length);
+   png_calculate_crc(png_ptr, buf, length);
+}
+/* Optionally skip data and then check the CRC.  Depending on whether we
+ * are reading a ancillary or critical chunk, and how the program has set
+ * things up, we may calculate the CRC on the data and print a message.
+ * Returns '1' if there was a CRC error, '0' otherwise.
+ */
+int /* PRIVATE */
+png_crc_finish(png_structp png_ptr, png_uint_32 skip)
+{
+   png_size_t i;
+   png_size_t istop = png_ptr->zbuf_size;
+   for (i = (png_size_t)skip; i > istop; i -= istop)
+   {
+      png_crc_read(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
+   }
+   if (i)
+   {
+      png_crc_read(png_ptr, png_ptr->zbuf, i);
+   }
+   if (png_crc_error(png_ptr))
+   {
+      if (PNG_CHUNK_ANCILLIARY(png_ptr->chunk_name) ?
+          !(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN) :
+          (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_USE))
+      {
+         png_chunk_warning(png_ptr, "CRC error");
+      }
+      else
+      {
+         png_chunk_benign_error(png_ptr, "CRC error");
+         return (0);
+      }
+      return (1);
+   }
+   return (0);
+}
+/* Compare the CRC stored in the PNG file with that calculated by libpng from
+ * the data it has read thus far.
+ */
+int /* PRIVATE */
+png_crc_error(png_structp png_ptr)
+{
+   png_byte crc_bytes[4];
+   png_uint_32 crc;
+   int need_crc = 1;
+   if (PNG_CHUNK_ANCILLIARY(png_ptr->chunk_name))
+   {
+      if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) ==
+          (PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN))
+         need_crc = 0;
+   }
+   else /* critical */
+   {
+      if (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE)
+         need_crc = 0;
+   }
+#ifdef PNG_IO_STATE_SUPPORTED
+   png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_CRC;
+#endif
+   /* The chunk CRC must be serialized in a single I/O call. */
+   png_read_data(png_ptr, crc_bytes, 4);
+   if (need_crc)
+   {
+      crc = png_get_uint_32(crc_bytes);
+      return ((int)(crc != png_ptr->crc));
+   }
+   else
+      return (0);
+}
+#ifdef PNG_READ_COMPRESSED_TEXT_SUPPORTED
+static png_size_t
+png_inflate(png_structp png_ptr, png_bytep data, png_size_t size,
+    png_bytep output, png_size_t output_size)
+{
+   png_size_t count = 0;
+   /* zlib can't necessarily handle more than 65535 bytes at once (i.e. it can't
+    * even necessarily handle 65536 bytes) because the type uInt is "16 bits or
+    * more".  Consequently it is necessary to chunk the input to zlib.  This
+    * code uses ZLIB_IO_MAX, from pngpriv.h, as the maximum (the maximum value
+    * that can be stored in a uInt.)  It is possible to set ZLIB_IO_MAX to a
+    * lower value in pngpriv.h and this may sometimes have a performance
+    * advantage, because it forces access of the input data to be separated from
+    * at least some of the use by some period of time.
+    */
+   png_ptr->zstream.next_in = data;
+   /* avail_in is set below from 'size' */
+   png_ptr->zstream.avail_in = 0;
+   while (1)
+   {
+      int ret, avail;
+      /* The setting of 'avail_in' used to be outside the loop; by setting it
+       * inside it is possible to chunk the input to zlib and simply rely on
+       * zlib to advance the 'next_in' pointer.  This allows arbitrary amounts o
+       * data to be passed through zlib at the unavoidable cost of requiring a
+       * window save (memcpy of up to 32768 output bytes) every ZLIB_IO_MAX
+       * input bytes.
+       */
+      if (png_ptr->zstream.avail_in == 0 && size > 0)
+      {
+         if (size <= ZLIB_IO_MAX)
+         {
+            /* The value is less than ZLIB_IO_MAX so the cast is safe: */
+            png_ptr->zstream.avail_in = (uInt)size;
+            size = 0;
+         }
+         else
+         {
+            png_ptr->zstream.avail_in = ZLIB_IO_MAX;
+            size -= ZLIB_IO_MAX;
+         }
+      }
+      /* Reset the output buffer each time round - we empty it
+       * after every inflate call.
+       */
+      png_ptr->zstream.next_out = png_ptr->zbuf;
+      png_ptr->zstream.avail_out = png_ptr->zbuf_size;
+      ret = inflate(&png_ptr->zstream, Z_NO_FLUSH);
+      avail = png_ptr->zbuf_size - png_ptr->zstream.avail_out;
+      /* First copy/count any new output - but only if we didn't
+       * get an error code.
+       */
+      if ((ret == Z_OK || ret == Z_STREAM_END) && avail > 0)
+      {
+         png_size_t space = avail; /* > 0, see above */
+         if (output != 0 && output_size > count)
+         {
+            png_size_t copy = output_size - count;
+            if (space < copy)
+               copy = space;
+            png_memcpy(output + count, png_ptr->zbuf, copy);
+         }
+         count += space;
+      }
+      if (ret == Z_OK)
+         continue;
+      /* Termination conditions - always reset the zstream, it
+       * must be left in inflateInit state.
+       */
+      png_ptr->zstream.avail_in = 0;
+      inflateReset(&png_ptr->zstream);
+      if (ret == Z_STREAM_END)
+         return count; /* NOTE: may be zero. */
+      /* Now handle the error codes - the API always returns 0
+       * and the error message is dumped into the uncompressed
+       * buffer if available.
+       */
+#     ifdef PNG_WARNINGS_SUPPORTED
+      {
+         png_const_charp msg;
+         if (png_ptr->zstream.msg != 0)
+            msg = png_ptr->zstream.msg;
+         else switch (ret)
+         {
+            case Z_BUF_ERROR:
+               msg = "Buffer error in compressed datastream";
+               break;
+            case Z_DATA_ERROR:
+               msg = "Data error in compressed datastream";
+               break;
+            default:
+               msg = "Incomplete compressed datastream";
+               break;
+         }
+         png_chunk_warning(png_ptr, msg);
+      }
+#     endif
+      /* 0 means an error - notice that this code simply ignores
+       * zero length compressed chunks as a result.
+       */
+      return 0;
+   }
+}
+/*
+ * Decompress trailing data in a chunk.  The assumption is that chunkdata
+ * points at an allocated area holding the contents of a chunk with a
+ * trailing compressed part.  What we get back is an allocated area
+ * holding the original prefix part and an uncompressed version of the
+ * trailing part (the malloc area passed in is freed).
+ */
+void /* PRIVATE */
+png_decompress_chunk(png_structp png_ptr, int comp_type,
+    png_size_t chunklength,
+    png_size_t prefix_size, png_size_t *newlength)
+{
+   /* The caller should guarantee this */
+   if (prefix_size > chunklength)
+   {
+      /* The recovery is to delete the chunk. */
+      png_warning(png_ptr, "invalid chunklength");
+      prefix_size = 0; /* To delete everything */
+   }
+   else if (comp_type == PNG_COMPRESSION_TYPE_BASE)
+   {
+      png_size_t expanded_size = png_inflate(png_ptr,
+          (png_bytep)(png_ptr->chunkdata + prefix_size),
+          chunklength - prefix_size,
+          0,            /* output */
+          0);           /* output size */
+      /* Now check the limits on this chunk - if the limit fails the
+       * compressed data will be removed, the prefix will remain.
+       */
+      if (prefix_size >= (~(png_size_t)0) - 1 ||
+         expanded_size >= (~(png_size_t)0) - 1 - prefix_size
+#ifdef PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED
+         || (png_ptr->user_chunk_malloc_max &&
+          (prefix_size + expanded_size >= png_ptr->user_chunk_malloc_max - 1))
+#else
+#  ifdef PNG_USER_CHUNK_MALLOC_MAX
+         || ((PNG_USER_CHUNK_MALLOC_MAX > 0) &&
+          prefix_size + expanded_size >= PNG_USER_CHUNK_MALLOC_MAX - 1)
+#  endif
+#endif
+         )
+         png_warning(png_ptr, "Exceeded size limit while expanding chunk");
+      /* If the size is zero either there was an error and a message
+       * has already been output (warning) or the size really is zero
+       * and we have nothing to do - the code will exit through the
+       * error case below.
+       */
+      else if (expanded_size > 0)
+      {
+         /* Success (maybe) - really uncompress the chunk. */
+         png_size_t new_size = 0;
+         png_charp text = (png_charp)png_malloc_warn(png_ptr,
+             prefix_size + expanded_size + 1);
+         if (text != NULL)
+         {
+            png_memcpy(text, png_ptr->chunkdata, prefix_size);
+            new_size = png_inflate(png_ptr,
+                (png_bytep)(png_ptr->chunkdata + prefix_size),
+                chunklength - prefix_size,
+                (png_bytep)(text + prefix_size), expanded_size);
+            text[prefix_size + expanded_size] = 0; /* just in case */
+            if (new_size == expanded_size)
+            {
+               png_free(png_ptr, png_ptr->chunkdata);
+               png_ptr->chunkdata = text;
+               *newlength = prefix_size + expanded_size;
+               return; /* The success return! */
+            }
+            png_warning(png_ptr, "png_inflate logic error");
+            png_free(png_ptr, text);
+         }
+         else
+            png_warning(png_ptr, "Not enough memory to decompress chunk");
+      }
+   }
+   else /* if (comp_type != PNG_COMPRESSION_TYPE_BASE) */
+   {
+      PNG_WARNING_PARAMETERS(p)
+      png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_d, comp_type);
+      png_formatted_warning(png_ptr, p, "Unknown compression type @1");
+      /* The recovery is to simply drop the data. */
+   }
+   /* Generic error return - leave the prefix, delete the compressed
+    * data, reallocate the chunkdata to remove the potentially large
+    * amount of compressed data.
+    */
+   {
+      png_charp text = (png_charp)png_malloc_warn(png_ptr, prefix_size + 1);
+      if (text != NULL)
+      {
+         if (prefix_size > 0)
+            png_memcpy(text, png_ptr->chunkdata, prefix_size);
+         png_free(png_ptr, png_ptr->chunkdata);
+         png_ptr->chunkdata = text;
+         /* This is an extra zero in the 'uncompressed' part. */
+         *(png_ptr->chunkdata + prefix_size) = 0x00;
+      }
+      /* Ignore a malloc error here - it is safe. */
+   }
+   *newlength = prefix_size;
+}
+#endif /* PNG_READ_COMPRESSED_TEXT_SUPPORTED */
+/* Read and check the IDHR chunk */
+void /* PRIVATE */
+png_handle_IHDR(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+   png_byte buf[13];
+   png_uint_32 width, height;
+   int bit_depth, color_type, compression_type, filter_type;
+   int interlace_type;
+   png_debug(1, "in png_handle_IHDR");
+   if (png_ptr->mode & PNG_HAVE_IHDR)
+      png_error(png_ptr, "Out of place IHDR");
+   /* Check the length */
+   if (length != 13)
+      png_error(png_ptr, "Invalid IHDR chunk");
+   png_ptr->mode |= PNG_HAVE_IHDR;
+   png_crc_read(png_ptr, buf, 13);
+   png_crc_finish(png_ptr, 0);
+   width = png_get_uint_31(png_ptr, buf);
+   height = png_get_uint_31(png_ptr, buf + 4);
+   bit_depth = buf[8];
+   color_type = buf[9];
+   compression_type = buf[10];
+   filter_type = buf[11];
+   interlace_type = buf[12];
+   /* Set internal variables */
+   png_ptr->width = width;
+   png_ptr->height = height;
+   png_ptr->bit_depth = (png_byte)bit_depth;
+   png_ptr->interlaced = (png_byte)interlace_type;
+   png_ptr->color_type = (png_byte)color_type;
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+   png_ptr->filter_type = (png_byte)filter_type;
+#endif
+   png_ptr->compression_type = (png_byte)compression_type;
+   /* Find number of channels */
+   switch (png_ptr->color_type)
+   {
+      default: /* invalid, png_set_IHDR calls png_error */
+      case PNG_COLOR_TYPE_GRAY:
+      case PNG_COLOR_TYPE_PALETTE:
+         png_ptr->channels = 1;
+         break;
+      case PNG_COLOR_TYPE_RGB:
+         png_ptr->channels = 3;
+         break;
+      case PNG_COLOR_TYPE_GRAY_ALPHA:
+         png_ptr->channels = 2;
+         break;
+      case PNG_COLOR_TYPE_RGB_ALPHA:
+         png_ptr->channels = 4;
+         break;
+   }
+   /* Set up other useful info */
+   png_ptr->pixel_depth = (png_byte)(png_ptr->bit_depth *
+   png_ptr->channels);
+   png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, png_ptr->width);
+   png_debug1(3, "bit_depth = %d", png_ptr->bit_depth);
+   png_debug1(3, "channels = %d", png_ptr->channels);
+   png_debug1(3, "rowbytes = %lu", (unsigned long)png_ptr->rowbytes);
+   png_set_IHDR(png_ptr, info_ptr, width, height, bit_depth,
+       color_type, interlace_type, compression_type, filter_type);
+}
+/* Read and check the palette */
+void /* PRIVATE */
+png_handle_PLTE(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+   png_color palette[PNG_MAX_PALETTE_LENGTH];
+   int num, i;
+#ifdef PNG_POINTER_INDEXING_SUPPORTED
+   png_colorp pal_ptr;
+#endif
+   png_debug(1, "in png_handle_PLTE");
+   if (!(png_ptr->mode & PNG_HAVE_IHDR))
+      png_error(png_ptr, "Missing IHDR before PLTE");
+   else if (png_ptr->mode & PNG_HAVE_IDAT)
+   {
+      png_warning(png_ptr, "Invalid PLTE after IDAT");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+   else if (png_ptr->mode & PNG_HAVE_PLTE)
+      png_error(png_ptr, "Duplicate PLTE chunk");
+   png_ptr->mode |= PNG_HAVE_PLTE;
+   if (!(png_ptr->color_type&PNG_COLOR_MASK_COLOR))
+   {
+      png_warning(png_ptr,
+          "Ignoring PLTE chunk in grayscale PNG");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+#ifndef PNG_READ_OPT_PLTE_SUPPORTED
+   if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)
+   {
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+#endif
+   if (length > 3*PNG_MAX_PALETTE_LENGTH || length % 3)
+   {
+      if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)
+      {
+         png_warning(png_ptr, "Invalid palette chunk");
+         png_crc_finish(png_ptr, length);
+         return;
+      }
+      else
+      {
+         png_error(png_ptr, "Invalid palette chunk");
+      }
+   }
+   num = (int)length / 3;
+#ifdef PNG_POINTER_INDEXING_SUPPORTED
+   for (i = 0, pal_ptr = palette; i < num; i++, pal_ptr++)
+   {
+      png_byte buf[3];
+      png_crc_read(png_ptr, buf, 3);
+      pal_ptr->red = buf[0];
+      pal_ptr->green = buf[1];
+      pal_ptr->blue = buf[2];
+   }
+#else
+   for (i = 0; i < num; i++)
+   {
+      png_byte buf[3];
+      png_crc_read(png_ptr, buf, 3);
+      /* Don't depend upon png_color being any order */
+      palette[i].red = buf[0];
+      palette[i].green = buf[1];
+      palette[i].blue = buf[2];
+   }
+#endif
+   /* If we actually need the PLTE chunk (ie for a paletted image), we do
+    * whatever the normal CRC configuration tells us.  However, if we
+    * have an RGB image, the PLTE can be considered ancillary, so
+    * we will act as though it is.
+    */
+#ifndef PNG_READ_OPT_PLTE_SUPPORTED
+   if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+#endif
+   {
+      png_crc_finish(png_ptr, 0);
+   }
+#ifndef PNG_READ_OPT_PLTE_SUPPORTED
+   else if (png_crc_error(png_ptr))  /* Only if we have a CRC error */
+   {
+      /* If we don't want to use the data from an ancillary chunk,
+       * we have two options: an error abort, or a warning and we
+       * ignore the data in this chunk (which should be OK, since
+       * it's considered ancillary for a RGB or RGBA image).
+       */
+      if (!(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_USE))
+      {
+         if (png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN)
+         {
+            png_chunk_benign_error(png_ptr, "CRC error");
+         }
+         else
+         {
+            png_chunk_warning(png_ptr, "CRC error");
+            return;
+         }
+      }
+      /* Otherwise, we (optionally) emit a warning and use the chunk. */
+      else if (!(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN))
+      {
+         png_chunk_warning(png_ptr, "CRC error");
+      }
+   }
+#endif
+   png_set_PLTE(png_ptr, info_ptr, palette, num);
+#ifdef PNG_READ_tRNS_SUPPORTED
+   if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+   {
+      if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS))
+      {
+         if (png_ptr->num_trans > (png_uint_16)num)
+         {
+            png_warning(png_ptr, "Truncating incorrect tRNS chunk length");
+            png_ptr->num_trans = (png_uint_16)num;
+         }
+         if (info_ptr->num_trans > (png_uint_16)num)
+         {
+            png_warning(png_ptr, "Truncating incorrect info tRNS chunk length");
+            info_ptr->num_trans = (png_uint_16)num;
+         }
+      }
+   }
+#endif
+}
+void /* PRIVATE */
+png_handle_IEND(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+   png_debug(1, "in png_handle_IEND");
+   if (!(png_ptr->mode & PNG_HAVE_IHDR) || !(png_ptr->mode & PNG_HAVE_IDAT))
+   {
+      png_error(png_ptr, "No image in file");
+   }
+   png_ptr->mode |= (PNG_AFTER_IDAT | PNG_HAVE_IEND);
+   if (length != 0)
+   {
+      png_warning(png_ptr, "Incorrect IEND chunk length");
+   }
+   png_crc_finish(png_ptr, length);
+   PNG_UNUSED(info_ptr) /* Quiet compiler warnings about unused info_ptr */
+}
+#ifdef PNG_READ_gAMA_SUPPORTED
+void /* PRIVATE */
+png_handle_gAMA(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+   png_fixed_point igamma;
+   png_byte buf[4];
+   png_debug(1, "in png_handle_gAMA");
+   if (!(png_ptr->mode & PNG_HAVE_IHDR))
+      png_error(png_ptr, "Missing IHDR before gAMA");
+   else if (png_ptr->mode & PNG_HAVE_IDAT)
+   {
+      png_warning(png_ptr, "Invalid gAMA after IDAT");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+   else if (png_ptr->mode & PNG_HAVE_PLTE)
+      /* Should be an error, but we can cope with it */
+      png_warning(png_ptr, "Out of place gAMA chunk");
+   if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA)
+#ifdef PNG_READ_sRGB_SUPPORTED
+       && !(info_ptr->valid & PNG_INFO_sRGB)
+#endif
+       )
+   {
+      png_warning(png_ptr, "Duplicate gAMA chunk");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+   if (length != 4)
+   {
+      png_warning(png_ptr, "Incorrect gAMA chunk length");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+   png_crc_read(png_ptr, buf, 4);
+   if (png_crc_finish(png_ptr, 0))
+      return;
+   igamma = png_get_fixed_point(NULL, buf);
+   /* Check for zero gamma or an error. */
+   if (igamma <= 0)
+   {
+      png_warning(png_ptr,
+          "Ignoring gAMA chunk with out of range gamma");
+      return;
+   }
+#  ifdef PNG_READ_sRGB_SUPPORTED
+   if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB))
+   {
+      if (PNG_OUT_OF_RANGE(igamma, 45500, 500))
+      {
+         PNG_WARNING_PARAMETERS(p)
+         png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_fixed, igamma);
+         png_formatted_warning(png_ptr, p,
+             "Ignoring incorrect gAMA value @1 when sRGB is also present");
+         return;
+      }
+   }
+#  endif /* PNG_READ_sRGB_SUPPORTED */
+#  ifdef PNG_READ_GAMMA_SUPPORTED
+   /* Gamma correction on read is supported. */
+   png_ptr->gamma = igamma;
+#  endif
+   /* And set the 'info' structure members. */
+   png_set_gAMA_fixed(png_ptr, info_ptr, igamma);
+}
+#endif
+#ifdef PNG_READ_sBIT_SUPPORTED
+void /* PRIVATE */
+png_handle_sBIT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+   png_size_t truelen;
+   png_byte buf[4];
+   png_debug(1, "in png_handle_sBIT");
+   buf[0] = buf[1] = buf[2] = buf[3] = 0;
+   if (!(png_ptr->mode & PNG_HAVE_IHDR))
+      png_error(png_ptr, "Missing IHDR before sBIT");
+   else if (png_ptr->mode & PNG_HAVE_IDAT)
+   {
+      png_warning(png_ptr, "Invalid sBIT after IDAT");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+   else if (png_ptr->mode & PNG_HAVE_PLTE)
+   {
+      /* Should be an error, but we can cope with it */
+      png_warning(png_ptr, "Out of place sBIT chunk");
+   }
+   if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sBIT))
+   {
+      png_warning(png_ptr, "Duplicate sBIT chunk");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+   if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+      truelen = 3;
+   else
+      truelen = (png_size_t)png_ptr->channels;
+   if (length != truelen || length > 4)
+   {
+      png_warning(png_ptr, "Incorrect sBIT chunk length");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+   png_crc_read(png_ptr, buf, truelen);
+   if (png_crc_finish(png_ptr, 0))
+      return;
+   if (png_ptr->color_type & PNG_COLOR_MASK_COLOR)
+   {
+      png_ptr->sig_bit.red = buf[0];
+      png_ptr->sig_bit.green = buf[1];
+      png_ptr->sig_bit.blue = buf[2];
+      png_ptr->sig_bit.alpha = buf[3];
+   }
+   else
+   {
+      png_ptr->sig_bit.gray = buf[0];
+      png_ptr->sig_bit.red = buf[0];
+      png_ptr->sig_bit.green = buf[0];
+      png_ptr->sig_bit.blue = buf[0];
+      png_ptr->sig_bit.alpha = buf[1];
+   }
+   png_set_sBIT(png_ptr, info_ptr, &(png_ptr->sig_bit));
+}
+#endif
+#ifdef PNG_READ_cHRM_SUPPORTED
+void /* PRIVATE */
+png_handle_cHRM(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+   png_byte buf[32];
+   png_fixed_point x_white, y_white, x_red, y_red, x_green, y_green, x_blue,
+      y_blue;
+   png_debug(1, "in png_handle_cHRM");
+   if (!(png_ptr->mode & PNG_HAVE_IHDR))
+      png_error(png_ptr, "Missing IHDR before cHRM");
+   else if (png_ptr->mode & PNG_HAVE_IDAT)
+   {
+      png_warning(png_ptr, "Invalid cHRM after IDAT");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+   else if (png_ptr->mode & PNG_HAVE_PLTE)
+      /* Should be an error, but we can cope with it */
+      png_warning(png_ptr, "Out of place cHRM chunk");
+   if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM)
+#  ifdef PNG_READ_sRGB_SUPPORTED
+       && !(info_ptr->valid & PNG_INFO_sRGB)
+#  endif
+      )
+   {
+      png_warning(png_ptr, "Duplicate cHRM chunk");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+   if (length != 32)
+   {
+      png_warning(png_ptr, "Incorrect cHRM chunk length");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+   png_crc_read(png_ptr, buf, 32);
+   if (png_crc_finish(png_ptr, 0))
+      return;
+   x_white = png_get_fixed_point(NULL, buf);
+   y_white = png_get_fixed_point(NULL, buf + 4);
+   x_red   = png_get_fixed_point(NULL, buf + 8);
+   y_red   = png_get_fixed_point(NULL, buf + 12);
+   x_green = png_get_fixed_point(NULL, buf + 16);
+   y_green = png_get_fixed_point(NULL, buf + 20);
+   x_blue  = png_get_fixed_point(NULL, buf + 24);
+   y_blue  = png_get_fixed_point(NULL, buf + 28);
+   if (x_white == PNG_FIXED_ERROR ||
+       y_white == PNG_FIXED_ERROR ||
+       x_red   == PNG_FIXED_ERROR ||
+       y_red   == PNG_FIXED_ERROR ||
+       x_green == PNG_FIXED_ERROR ||
+       y_green == PNG_FIXED_ERROR ||
+       x_blue  == PNG_FIXED_ERROR ||
+       y_blue  == PNG_FIXED_ERROR)
+   {
+      png_warning(png_ptr, "Ignoring cHRM chunk with negative chromaticities");
+      return;
+   }
+#ifdef PNG_READ_sRGB_SUPPORTED
+   if ((info_ptr != NULL) && (info_ptr->valid & PNG_INFO_sRGB))
+   {
+      if (PNG_OUT_OF_RANGE(x_white, 31270,  1000) ||
+          PNG_OUT_OF_RANGE(y_white, 32900,  1000) ||
+          PNG_OUT_OF_RANGE(x_red,   64000,  1000) ||
+          PNG_OUT_OF_RANGE(y_red,   33000,  1000) ||
+          PNG_OUT_OF_RANGE(x_green, 30000,  1000) ||
+          PNG_OUT_OF_RANGE(y_green, 60000,  1000) ||
+          PNG_OUT_OF_RANGE(x_blue,  15000,  1000) ||
+          PNG_OUT_OF_RANGE(y_blue,   6000,  1000))
+      {
+         PNG_WARNING_PARAMETERS(p)
+         png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_fixed, x_white);
+         png_warning_parameter_signed(p, 2, PNG_NUMBER_FORMAT_fixed, y_white);
+         png_warning_parameter_signed(p, 3, PNG_NUMBER_FORMAT_fixed, x_red);
+         png_warning_parameter_signed(p, 4, PNG_NUMBER_FORMAT_fixed, y_red);
+         png_warning_parameter_signed(p, 5, PNG_NUMBER_FORMAT_fixed, x_green);
+         png_warning_parameter_signed(p, 6, PNG_NUMBER_FORMAT_fixed, y_green);
+         png_warning_parameter_signed(p, 7, PNG_NUMBER_FORMAT_fixed, x_blue);
+         png_warning_parameter_signed(p, 8, PNG_NUMBER_FORMAT_fixed, y_blue);
+         png_formatted_warning(png_ptr, p,
+             "Ignoring incorrect cHRM white(@1,@2) r(@3,@4)g(@5,@6)b(@7,@8) "
+             "when sRGB is also present");
+      }
+      return;
+   }
+#endif /* PNG_READ_sRGB_SUPPORTED */
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+   /* Store the _white values as default coefficients for the rgb to gray
+    * operation if it is supported.  Check if the transform is already set to
+    * avoid destroying the transform values.
+    */
+   if (!png_ptr->rgb_to_gray_coefficients_set)
+   {
+      /* png_set_background has not been called and we haven't seen an sRGB
+       * chunk yet.  Find the XYZ of the three end points.
+       */
+      png_XYZ XYZ;
+      png_xy xy;
+      xy.redx = x_red;
+      xy.redy = y_red;
+      xy.greenx = x_green;
+      xy.greeny = y_green;
+      xy.bluex = x_blue;
+      xy.bluey = y_blue;
+      xy.whitex = x_white;
+      xy.whitey = y_white;
+      if (png_XYZ_from_xy_checked(png_ptr, &XYZ, xy))
+      {
+         /* The success case, because XYZ_from_xy normalises to a reference
+          * white Y of 1.0 we just need to scale the numbers.  This should
+          * always work just fine. It is an internal error if this overflows.
+          */
+         {
+            png_fixed_point r, g, b;
+            if (png_muldiv(&r, XYZ.redY, 32768, PNG_FP_1) &&
+               r >= 0 && r <= 32768 &&
+               png_muldiv(&g, XYZ.greenY, 32768, PNG_FP_1) &&
+               g >= 0 && g <= 32768 &&
+               png_muldiv(&b, XYZ.blueY, 32768, PNG_FP_1) &&
+               b >= 0 && b <= 32768 &&
+               r+g+b <= 32769)
+            {
+               /* We allow 0 coefficients here.  r+g+b may be 32769 if two or
+                * all of the coefficients were rounded up.  Handle this by
+                * reducing the *largest* coefficient by 1; this matches the
+                * approach used for the default coefficients in pngrtran.c
+                */
+               int add = 0;
+               if (r+g+b > 32768)
+                  add = -1;
+               else if (r+g+b < 32768)
+                  add = 1;
+               if (add != 0)
+               {
+                  if (g >= r && g >= b)
+                     g += add;
+                  else if (r >= g && r >= b)
+                     r += add;
+                  else
+                     b += add;
+               }
+               /* Check for an internal error. */
+               if (r+g+b != 32768)
+                  png_error(png_ptr,
+                     "internal error handling cHRM coefficients");
+               png_ptr->rgb_to_gray_red_coeff   = (png_uint_16)r;
+               png_ptr->rgb_to_gray_green_coeff = (png_uint_16)g;
+            }
+            /* This is a png_error at present even though it could be ignored -
+             * it should never happen, but it is important that if it does, the
+             * bug is fixed.
+             */
+            else
+               png_error(png_ptr, "internal error handling cHRM->XYZ");
+         }
+      }
+   }
+#endif
+   png_set_cHRM_fixed(png_ptr, info_ptr, x_white, y_white, x_red, y_red,
+      x_green, y_green, x_blue, y_blue);
+}
+#endif
+#ifdef PNG_READ_sRGB_SUPPORTED
+void /* PRIVATE */
+png_handle_sRGB(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+   int intent;
+   png_byte buf[1];
+   png_debug(1, "in png_handle_sRGB");
+   if (!(png_ptr->mode & PNG_HAVE_IHDR))
+      png_error(png_ptr, "Missing IHDR before sRGB");
+   else if (png_ptr->mode & PNG_HAVE_IDAT)
+   {
+      png_warning(png_ptr, "Invalid sRGB after IDAT");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+   else if (png_ptr->mode & PNG_HAVE_PLTE)
+      /* Should be an error, but we can cope with it */
+      png_warning(png_ptr, "Out of place sRGB chunk");
+   if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB))
+   {
+      png_warning(png_ptr, "Duplicate sRGB chunk");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+   if (length != 1)
+   {
+      png_warning(png_ptr, "Incorrect sRGB chunk length");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+   png_crc_read(png_ptr, buf, 1);
+   if (png_crc_finish(png_ptr, 0))
+      return;
+   intent = buf[0];
+   /* Check for bad intent */
+   if (intent >= PNG_sRGB_INTENT_LAST)
+   {
+      png_warning(png_ptr, "Unknown sRGB intent");
+      return;
+   }
+#if defined(PNG_READ_gAMA_SUPPORTED) && defined(PNG_READ_GAMMA_SUPPORTED)
+   if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA))
+   {
+      if (PNG_OUT_OF_RANGE(info_ptr->gamma, 45500, 500))
+      {
+         PNG_WARNING_PARAMETERS(p)
+         png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_fixed,
+            info_ptr->gamma);
+         png_formatted_warning(png_ptr, p,
+             "Ignoring incorrect gAMA value @1 when sRGB is also present");
+      }
+   }
+#endif /* PNG_READ_gAMA_SUPPORTED */
+#ifdef PNG_READ_cHRM_SUPPORTED
+   if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM))
+      if (PNG_OUT_OF_RANGE(info_ptr->x_white, 31270,  1000) ||
+          PNG_OUT_OF_RANGE(info_ptr->y_white, 32900,  1000) ||
+          PNG_OUT_OF_RANGE(info_ptr->x_red,   64000,  1000) ||
+          PNG_OUT_OF_RANGE(info_ptr->y_red,   33000,  1000) ||
+          PNG_OUT_OF_RANGE(info_ptr->x_green, 30000,  1000) ||
+          PNG_OUT_OF_RANGE(info_ptr->y_green, 60000,  1000) ||
+          PNG_OUT_OF_RANGE(info_ptr->x_blue,  15000,  1000) ||
+          PNG_OUT_OF_RANGE(info_ptr->y_blue,   6000,  1000))
+      {
+         png_warning(png_ptr,
+             "Ignoring incorrect cHRM value when sRGB is also present");
+      }
+#endif /* PNG_READ_cHRM_SUPPORTED */
+   /* This is recorded for use when handling the cHRM chunk above.  An sRGB
+    * chunk unconditionally overwrites the coefficients for grayscale conversion
+    * too.
+    */
+   png_ptr->is_sRGB = 1;
+#  ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+      /* Don't overwrite user supplied values: */
+      if (!png_ptr->rgb_to_gray_coefficients_set)
+      {
+         /* These numbers come from the sRGB specification (or, since one has to
+          * pay much money to get a copy, the wikipedia sRGB page) the
+          * chromaticity values quoted have been inverted to get the reverse
+          * transformation from RGB to XYZ and the 'Y' coefficients scaled by
+          * 32768 (then rounded).
+          *
+          * sRGB and ITU Rec-709 both truncate the values for the D65 white
+          * point to four digits and, even though it actually stores five
+          * digits, the PNG spec gives the truncated value.
+          *
+          * This means that when the chromaticities are converted back to XYZ
+          * end points we end up with (6968,23435,2366), which, as described in
+          * pngrtran.c, would overflow.  If the five digit precision and up is
+          * used we get, instead:
+          *
+          *    6968*R + 23435*G + 2365*B
+          *
+          * (Notice that this rounds the blue coefficient down, rather than the
+          * choice used in pngrtran.c which is to round the green one down.)
+          */
+         png_ptr->rgb_to_gray_red_coeff   =  6968; /* 0.212639005871510 */
+         png_ptr->rgb_to_gray_green_coeff = 23434; /* 0.715168678767756 */
+         /* png_ptr->rgb_to_gray_blue_coeff  =  2366; 0.072192315360734 */
+         /* The following keeps the cHRM chunk from destroying the
+          * coefficients again in the event that it follows the sRGB chunk.
+          */
+         png_ptr->rgb_to_gray_coefficients_set = 1;
+      }
+#  endif
+   png_set_sRGB_gAMA_and_cHRM(png_ptr, info_ptr, intent);
+}
+#endif /* PNG_READ_sRGB_SUPPORTED */
+#ifdef PNG_READ_iCCP_SUPPORTED
+void /* PRIVATE */
+png_handle_iCCP(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+/* Note: this does not properly handle chunks that are > 64K under DOS */
+{
+   png_byte compression_type;
+   png_bytep pC;
+   png_charp profile;
+   png_uint_32 skip = 0;
+   png_uint_32 profile_size;
+   png_alloc_size_t profile_length;
+   png_size_t slength, prefix_length, data_length;
+   png_debug(1, "in png_handle_iCCP");
+   if (!(png_ptr->mode & PNG_HAVE_IHDR))
+      png_error(png_ptr, "Missing IHDR before iCCP");
+   else if (png_ptr->mode & PNG_HAVE_IDAT)
+   {
+      png_warning(png_ptr, "Invalid iCCP after IDAT");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+   else if (png_ptr->mode & PNG_HAVE_PLTE)
+      /* Should be an error, but we can cope with it */
+      png_warning(png_ptr, "Out of place iCCP chunk");
+   if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_iCCP))
+   {
+      png_warning(png_ptr, "Duplicate iCCP chunk");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+#ifdef PNG_MAX_MALLOC_64K
+   if (length > (png_uint_32)65535L)
+   {
+      png_warning(png_ptr, "iCCP chunk too large to fit in memory");
+      skip = length - (png_uint_32)65535L;
+      length = (png_uint_32)65535L;
+   }
+#endif
+   png_free(png_ptr, png_ptr->chunkdata);
+   png_ptr->chunkdata = (png_charp)png_malloc(png_ptr, length + 1);
+   slength = length;
+   png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
+   if (png_crc_finish(png_ptr, skip))
+   {
+      png_free(png_ptr, png_ptr->chunkdata);
+      png_ptr->chunkdata = NULL;
+      return;
+   }
+   png_ptr->chunkdata[slength] = 0x00;
+   for (profile = png_ptr->chunkdata; *profile; profile++)
+      /* Empty loop to find end of name */ ;
+   ++profile;
+   /* There should be at least one zero (the compression type byte)
+    * following the separator, and we should be on it
+    */
+   if (profile >= png_ptr->chunkdata + slength - 1)
+   {
+      png_free(png_ptr, png_ptr->chunkdata);
+      png_ptr->chunkdata = NULL;
+      png_warning(png_ptr, "Malformed iCCP chunk");
+      return;
+   }
+   /* Compression_type should always be zero */
+   compression_type = *profile++;
+   if (compression_type)
+   {
+      png_warning(png_ptr, "Ignoring nonzero compression type in iCCP chunk");
+      compression_type = 0x00;  /* Reset it to zero (libpng-1.0.6 through 1.0.8
+                                 wrote nonzero) */
+   }
+   prefix_length = profile - png_ptr->chunkdata;
+   png_decompress_chunk(png_ptr, compression_type,
+       slength, prefix_length, &data_length);
+   profile_length = data_length - prefix_length;
+   if (prefix_length > data_length || profile_length < 4)
+   {
+      png_free(png_ptr, png_ptr->chunkdata);
+      png_ptr->chunkdata = NULL;
+      png_warning(png_ptr, "Profile size field missing from iCCP chunk");
+      return;
+   }
+   /* Check the profile_size recorded in the first 32 bits of the ICC profile */
+   pC = (png_bytep)(png_ptr->chunkdata + prefix_length);
+   profile_size = ((*(pC    )) << 24) |
+                  ((*(pC + 1)) << 16) |
+                  ((*(pC + 2)) <<  8) |
+                  ((*(pC + 3))      );
+   /* NOTE: the following guarantees that 'profile_length' fits into 32 bits,
+    * because profile_size is a 32 bit value.
+    */
+   if (profile_size < profile_length)
+      profile_length = profile_size;
+   /* And the following guarantees that profile_size == profile_length. */
+   if (profile_size > profile_length)
+   {
+      PNG_WARNING_PARAMETERS(p)
+      png_free(png_ptr, png_ptr->chunkdata);
+      png_ptr->chunkdata = NULL;
+      png_warning_parameter_unsigned(p, 1, PNG_NUMBER_FORMAT_u, profile_size);
+      png_warning_parameter_unsigned(p, 2, PNG_NUMBER_FORMAT_u, profile_length);
+      png_formatted_warning(png_ptr, p,
+         "Ignoring iCCP chunk with declared size = @1 and actual length = @2");
+      return;
+   }
+   png_set_iCCP(png_ptr, info_ptr, png_ptr->chunkdata,
+       compression_type, (png_bytep)png_ptr->chunkdata + prefix_length,
+       profile_size);
+   png_free(png_ptr, png_ptr->chunkdata);
+   png_ptr->chunkdata = NULL;
+}
+#endif /* PNG_READ_iCCP_SUPPORTED */
+#ifdef PNG_READ_sPLT_SUPPORTED
+void /* PRIVATE */
+png_handle_sPLT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+/* Note: this does not properly handle chunks that are > 64K under DOS */
+{
+   png_bytep entry_start;
+   png_sPLT_t new_palette;
+   png_sPLT_entryp pp;
+   png_uint_32 data_length;
+   int entry_size, i;
+   png_uint_32 skip = 0;
+   png_size_t slength;
+   png_uint_32 dl;
+   png_size_t max_dl;
+   png_debug(1, "in png_handle_sPLT");
+#ifdef PNG_USER_LIMITS_SUPPORTED
+   if (png_ptr->user_chunk_cache_max != 0)
+   {
+      if (png_ptr->user_chunk_cache_max == 1)
+      {
+         png_crc_finish(png_ptr, length);
+         return;
+      }
+      if (--png_ptr->user_chunk_cache_max == 1)
+      {
+         png_warning(png_ptr, "No space in chunk cache for sPLT");
+         png_crc_finish(png_ptr, length);
+         return;
+      }
+   }
+#endif
+   if (!(png_ptr->mode & PNG_HAVE_IHDR))
+      png_error(png_ptr, "Missing IHDR before sPLT");
+   else if (png_ptr->mode & PNG_HAVE_IDAT)
+   {
+      png_warning(png_ptr, "Invalid sPLT after IDAT");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+#ifdef PNG_MAX_MALLOC_64K
+   if (length > (png_uint_32)65535L)
+   {
+      png_warning(png_ptr, "sPLT chunk too large to fit in memory");
+      skip = length - (png_uint_32)65535L;
+      length = (png_uint_32)65535L;
+   }
+#endif
+   png_free(png_ptr, png_ptr->chunkdata);
+   png_ptr->chunkdata = (png_charp)png_malloc(png_ptr, length + 1);
+   /* WARNING: this may break if size_t is less than 32 bits; it is assumed
+    * that the PNG_MAX_MALLOC_64K test is enabled in this case, but this is a
+    * potential breakage point if the types in pngconf.h aren't exactly right.
+    */
+   slength = length;
+   png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
+   if (png_crc_finish(png_ptr, skip))
+   {
+      png_free(png_ptr, png_ptr->chunkdata);
+      png_ptr->chunkdata = NULL;
+      return;
+   }
+   png_ptr->chunkdata[slength] = 0x00;
+   for (entry_start = (png_bytep)png_ptr->chunkdata; *entry_start;
+       entry_start++)
+      /* Empty loop to find end of name */ ;
+   ++entry_start;
+   /* A sample depth should follow the separator, and we should be on it  */
+   if (entry_start > (png_bytep)png_ptr->chunkdata + slength - 2)
+   {
+      png_free(png_ptr, png_ptr->chunkdata);
+      png_ptr->chunkdata = NULL;
+      png_warning(png_ptr, "malformed sPLT chunk");
+      return;
+   }
+   new_palette.depth = *entry_start++;
+   entry_size = (new_palette.depth == 8 ? 6 : 10);
+   /* This must fit in a png_uint_32 because it is derived from the original
+    * chunk data length (and use 'length', not 'slength' here for clarity -
+    * they are guaranteed to be the same, see the tests above.)
+    */
+   data_length = length - (png_uint_32)(entry_start -
+      (png_bytep)png_ptr->chunkdata);
+   /* Integrity-check the data length */
+   if (data_length % entry_size)
+   {
+      png_free(png_ptr, png_ptr->chunkdata);
+      png_ptr->chunkdata = NULL;
+      png_warning(png_ptr, "sPLT chunk has bad length");
+      return;
+   }
+   dl = (png_int_32)(data_length / entry_size);
+   max_dl = PNG_SIZE_MAX / png_sizeof(png_sPLT_entry);
+   if (dl > max_dl)
+   {
+       png_warning(png_ptr, "sPLT chunk too long");
+       return;
+   }
+   new_palette.nentries = (png_int_32)(data_length / entry_size);
+   new_palette.entries = (png_sPLT_entryp)png_malloc_warn(
+       png_ptr, new_palette.nentries * png_sizeof(png_sPLT_entry));
+   if (new_palette.entries == NULL)
+   {
+       png_warning(png_ptr, "sPLT chunk requires too much memory");
+       return;
+   }
+#ifdef PNG_POINTER_INDEXING_SUPPORTED
+   for (i = 0; i < new_palette.nentries; i++)
+   {
+      pp = new_palette.entries + i;
+      if (new_palette.depth == 8)
+      {
+         pp->red = *entry_start++;
+         pp->green = *entry_start++;
+         pp->blue = *entry_start++;
+         pp->alpha = *entry_start++;
+      }
+      else
+      {
+         pp->red   = png_get_uint_16(entry_start); entry_start += 2;
+         pp->green = png_get_uint_16(entry_start); entry_start += 2;
+         pp->blue  = png_get_uint_16(entry_start); entry_start += 2;
+         pp->alpha = png_get_uint_16(entry_start); entry_start += 2;
+      }
+      pp->frequency = png_get_uint_16(entry_start); entry_start += 2;
+   }
+#else
+   pp = new_palette.entries;
+   for (i = 0; i < new_palette.nentries; i++)
+   {
+      if (new_palette.depth == 8)
+      {
+         pp[i].red   = *entry_start++;
+         pp[i].green = *entry_start++;
+         pp[i].blue  = *entry_start++;
+         pp[i].alpha = *entry_start++;
+      }
+      else
+      {
+         pp[i].red   = png_get_uint_16(entry_start); entry_start += 2;
+         pp[i].green = png_get_uint_16(entry_start); entry_start += 2;
+         pp[i].blue  = png_get_uint_16(entry_start); entry_start += 2;
+         pp[i].alpha = png_get_uint_16(entry_start); entry_start += 2;
+      }
+      pp[i].frequency = png_get_uint_16(entry_start); entry_start += 2;
+   }
+#endif
+   /* Discard all chunk data except the name and stash that */
+   new_palette.name = png_ptr->chunkdata;
+   png_set_sPLT(png_ptr, info_ptr, &new_palette, 1);
+   png_free(png_ptr, png_ptr->chunkdata);
+   png_ptr->chunkdata = NULL;
+   png_free(png_ptr, new_palette.entries);
+}
+#endif /* PNG_READ_sPLT_SUPPORTED */
+#ifdef PNG_READ_tRNS_SUPPORTED
+void /* PRIVATE */
+png_handle_tRNS(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+   png_byte readbuf[PNG_MAX_PALETTE_LENGTH];
+   png_debug(1, "in png_handle_tRNS");
+   if (!(png_ptr->mode & PNG_HAVE_IHDR))
+      png_error(png_ptr, "Missing IHDR before tRNS");
+   else if (png_ptr->mode & PNG_HAVE_IDAT)
+   {
+      png_warning(png_ptr, "Invalid tRNS after IDAT");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+   else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS))
+   {
+      png_warning(png_ptr, "Duplicate tRNS chunk");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+   if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
+   {
+      png_byte buf[2];
+      if (length != 2)
+      {
+         png_warning(png_ptr, "Incorrect tRNS chunk length");
+         png_crc_finish(png_ptr, length);
+         return;
+      }
+      png_crc_read(png_ptr, buf, 2);
+      png_ptr->num_trans = 1;
+      png_ptr->trans_color.gray = png_get_uint_16(buf);
+   }
+   else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
+   {
+      png_byte buf[6];
+      if (length != 6)
+      {
+         png_warning(png_ptr, "Incorrect tRNS chunk length");
+         png_crc_finish(png_ptr, length);
+         return;
+      }
+      png_crc_read(png_ptr, buf, (png_size_t)length);
+      png_ptr->num_trans = 1;
+      png_ptr->trans_color.red = png_get_uint_16(buf);
+      png_ptr->trans_color.green = png_get_uint_16(buf + 2);
+      png_ptr->trans_color.blue = png_get_uint_16(buf + 4);
+   }
+   else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+   {
+      if (!(png_ptr->mode & PNG_HAVE_PLTE))
+      {
+         /* Should be an error, but we can cope with it. */
+         png_warning(png_ptr, "Missing PLTE before tRNS");
+      }
+      if (length > (png_uint_32)png_ptr->num_palette ||
+          length > PNG_MAX_PALETTE_LENGTH)
+      {
+         png_warning(png_ptr, "Incorrect tRNS chunk length");
+         png_crc_finish(png_ptr, length);
+         return;
+      }
+      if (length == 0)
+      {
+         png_warning(png_ptr, "Zero length tRNS chunk");
+         png_crc_finish(png_ptr, length);
+         return;
+      }
+      png_crc_read(png_ptr, readbuf, (png_size_t)length);
+      png_ptr->num_trans = (png_uint_16)length;
+   }
+   else
+   {
+      png_warning(png_ptr, "tRNS chunk not allowed with alpha channel");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+   if (png_crc_finish(png_ptr, 0))
+   {
+      png_ptr->num_trans = 0;
+      return;
+   }
+   png_set_tRNS(png_ptr, info_ptr, readbuf, png_ptr->num_trans,
+       &(png_ptr->trans_color));
+}
+#endif
+#ifdef PNG_READ_bKGD_SUPPORTED
+void /* PRIVATE */
+png_handle_bKGD(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+   png_size_t truelen;
+   png_byte buf[6];
+   png_color_16 background;
+   png_debug(1, "in png_handle_bKGD");
+   if (!(png_ptr->mode & PNG_HAVE_IHDR))
+      png_error(png_ptr, "Missing IHDR before bKGD");
+   else if (png_ptr->mode & PNG_HAVE_IDAT)
+   {
+      png_warning(png_ptr, "Invalid bKGD after IDAT");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+   else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
+       !(png_ptr->mode & PNG_HAVE_PLTE))
+   {
+      png_warning(png_ptr, "Missing PLTE before bKGD");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+   else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_bKGD))
+   {
+      png_warning(png_ptr, "Duplicate bKGD chunk");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+   if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+      truelen = 1;
+   else if (png_ptr->color_type & PNG_COLOR_MASK_COLOR)
+      truelen = 6;
+   else
+      truelen = 2;
+   if (length != truelen)
+   {
+      png_warning(png_ptr, "Incorrect bKGD chunk length");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+   png_crc_read(png_ptr, buf, truelen);
+   if (png_crc_finish(png_ptr, 0))
+      return;
+   /* We convert the index value into RGB components so that we can allow
+    * arbitrary RGB values for background when we have transparency, and
+    * so it is easy to determine the RGB values of the background color
+    * from the info_ptr struct.
+    */
+   if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+   {
+      background.index = buf[0];
+      if (info_ptr && info_ptr->num_palette)
+      {
+         if (buf[0] >= info_ptr->num_palette)
+         {
+            png_warning(png_ptr, "Incorrect bKGD chunk index value");
+            return;
+         }
+         background.red = (png_uint_16)png_ptr->palette[buf[0]].red;
+         background.green = (png_uint_16)png_ptr->palette[buf[0]].green;
+         background.blue = (png_uint_16)png_ptr->palette[buf[0]].blue;
+      }
+      else
+         background.red = background.green = background.blue = 0;
+      background.gray = 0;
+   }
+   else if (!(png_ptr->color_type & PNG_COLOR_MASK_COLOR)) /* GRAY */
+   {
+      background.index = 0;
+      background.red =
+      background.green =
+      background.blue =
+      background.gray = png_get_uint_16(buf);
+   }
+   else
+   {
+      background.index = 0;
+      background.red = png_get_uint_16(buf);
+      background.green = png_get_uint_16(buf + 2);
+      background.blue = png_get_uint_16(buf + 4);
+      background.gray = 0;
+   }
+   png_set_bKGD(png_ptr, info_ptr, &background);
+}
+#endif
+#ifdef PNG_READ_hIST_SUPPORTED
+void /* PRIVATE */
+png_handle_hIST(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+   unsigned int num, i;
+   png_uint_16 readbuf[PNG_MAX_PALETTE_LENGTH];
+   png_debug(1, "in png_handle_hIST");
+   if (!(png_ptr->mode & PNG_HAVE_IHDR))
+      png_error(png_ptr, "Missing IHDR before hIST");
+   else if (png_ptr->mode & PNG_HAVE_IDAT)
+   {
+      png_warning(png_ptr, "Invalid hIST after IDAT");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+   else if (!(png_ptr->mode & PNG_HAVE_PLTE))
+   {
+      png_warning(png_ptr, "Missing PLTE before hIST");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+   else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_hIST))
+   {
+      png_warning(png_ptr, "Duplicate hIST chunk");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+   num = length / 2 ;
+   if (num != (unsigned int)png_ptr->num_palette || num >
+       (unsigned int)PNG_MAX_PALETTE_LENGTH)
+   {
+      png_warning(png_ptr, "Incorrect hIST chunk length");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+   for (i = 0; i < num; i++)
+   {
+      png_byte buf[2];
+      png_crc_read(png_ptr, buf, 2);
+      readbuf[i] = png_get_uint_16(buf);
+   }
+   if (png_crc_finish(png_ptr, 0))
+      return;
+   png_set_hIST(png_ptr, info_ptr, readbuf);
+}
+#endif
+#ifdef PNG_READ_pHYs_SUPPORTED
+void /* PRIVATE */
+png_handle_pHYs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+   png_byte buf[9];
+   png_uint_32 res_x, res_y;
+   int unit_type;
+   png_debug(1, "in png_handle_pHYs");
+   if (!(png_ptr->mode & PNG_HAVE_IHDR))
+      png_error(png_ptr, "Missing IHDR before pHYs");
+   else if (png_ptr->mode & PNG_HAVE_IDAT)
+   {
+      png_warning(png_ptr, "Invalid pHYs after IDAT");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+   else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
+   {
+      png_warning(png_ptr, "Duplicate pHYs chunk");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+   if (length != 9)
+   {
+      png_warning(png_ptr, "Incorrect pHYs chunk length");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+   png_crc_read(png_ptr, buf, 9);
+   if (png_crc_finish(png_ptr, 0))
+      return;
+   res_x = png_get_uint_32(buf);
+   res_y = png_get_uint_32(buf + 4);
+   unit_type = buf[8];
+   png_set_pHYs(png_ptr, info_ptr, res_x, res_y, unit_type);
+}
+#endif
+#ifdef PNG_READ_oFFs_SUPPORTED
+void /* PRIVATE */
+png_handle_oFFs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+   png_byte buf[9];
+   png_int_32 offset_x, offset_y;
+   int unit_type;
+   png_debug(1, "in png_handle_oFFs");
+   if (!(png_ptr->mode & PNG_HAVE_IHDR))
+      png_error(png_ptr, "Missing IHDR before oFFs");
+   else if (png_ptr->mode & PNG_HAVE_IDAT)
+   {
+      png_warning(png_ptr, "Invalid oFFs after IDAT");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+   else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
+   {
+      png_warning(png_ptr, "Duplicate oFFs chunk");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+   if (length != 9)
+   {
+      png_warning(png_ptr, "Incorrect oFFs chunk length");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+   png_crc_read(png_ptr, buf, 9);
+   if (png_crc_finish(png_ptr, 0))
+      return;
+   offset_x = png_get_int_32(buf);
+   offset_y = png_get_int_32(buf + 4);
+   unit_type = buf[8];
+   png_set_oFFs(png_ptr, info_ptr, offset_x, offset_y, unit_type);
+}
+#endif
+#ifdef PNG_READ_pCAL_SUPPORTED
+/* Read the pCAL chunk (described in the PNG Extensions document) */
+void /* PRIVATE */
+png_handle_pCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+   png_int_32 X0, X1;
+   png_byte type, nparams;
+   png_charp buf, units, endptr;
+   png_charpp params;
+   png_size_t slength;
+   int i;
+   png_debug(1, "in png_handle_pCAL");
+   if (!(png_ptr->mode & PNG_HAVE_IHDR))
+      png_error(png_ptr, "Missing IHDR before pCAL");
+   else if (png_ptr->mode & PNG_HAVE_IDAT)
+   {
+      png_warning(png_ptr, "Invalid pCAL after IDAT");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+   else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pCAL))
+   {
+      png_warning(png_ptr, "Duplicate pCAL chunk");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+   png_debug1(2, "Allocating and reading pCAL chunk data (%u bytes)",
+       length + 1);
+   png_free(png_ptr, png_ptr->chunkdata);
+   png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
+   if (png_ptr->chunkdata == NULL)
+   {
+      png_warning(png_ptr, "No memory for pCAL purpose");
+      return;
+   }
+   slength = length;
+   png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
+   if (png_crc_finish(png_ptr, 0))
+   {
+      png_free(png_ptr, png_ptr->chunkdata);
+      png_ptr->chunkdata = NULL;
+      return;
+   }
+   png_ptr->chunkdata[slength] = 0x00; /* Null terminate the last string */
+   png_debug(3, "Finding end of pCAL purpose string");
+   for (buf = png_ptr->chunkdata; *buf; buf++)
+      /* Empty loop */ ;
+   endptr = png_ptr->chunkdata + slength;
+   /* We need to have at least 12 bytes after the purpose string
+    * in order to get the parameter information.
+    */
+   if (endptr <= buf + 12)
+   {
+      png_warning(png_ptr, "Invalid pCAL data");
+      png_free(png_ptr, png_ptr->chunkdata);
+      png_ptr->chunkdata = NULL;
+      return;
+   }
+   png_debug(3, "Reading pCAL X0, X1, type, nparams, and units");
+   X0 = png_get_int_32((png_bytep)buf+1);
+   X1 = png_get_int_32((png_bytep)buf+5);
+   type = buf[9];
+   nparams = buf[10];
+   units = buf + 11;
+   png_debug(3, "Checking pCAL equation type and number of parameters");
+   /* Check that we have the right number of parameters for known
+    * equation types.
+    */
+   if ((type == PNG_EQUATION_LINEAR && nparams != 2) ||
+       (type == PNG_EQUATION_BASE_E && nparams != 3) ||
+       (type == PNG_EQUATION_ARBITRARY && nparams != 3) ||
+       (type == PNG_EQUATION_HYPERBOLIC && nparams != 4))
+   {
+      png_warning(png_ptr, "Invalid pCAL parameters for equation type");
+      png_free(png_ptr, png_ptr->chunkdata);
+      png_ptr->chunkdata = NULL;
+      return;
+   }
+   else if (type >= PNG_EQUATION_LAST)
+   {
+      png_warning(png_ptr, "Unrecognized equation type for pCAL chunk");
+   }
+   for (buf = units; *buf; buf++)
+      /* Empty loop to move past the units string. */ ;
+   png_debug(3, "Allocating pCAL parameters array");
+   params = (png_charpp)png_malloc_warn(png_ptr,
+       (png_size_t)(nparams * png_sizeof(png_charp)));
+   if (params == NULL)
+   {
+      png_free(png_ptr, png_ptr->chunkdata);
+      png_ptr->chunkdata = NULL;
+      png_warning(png_ptr, "No memory for pCAL params");
+      return;
+   }
+   /* Get pointers to the start of each parameter string. */
+   for (i = 0; i < (int)nparams; i++)
+   {
+      buf++; /* Skip the null string terminator from previous parameter. */
+      png_debug1(3, "Reading pCAL parameter %d", i);
+      for (params[i] = buf; buf <= endptr && *buf != 0x00; buf++)
+         /* Empty loop to move past each parameter string */ ;
+      /* Make sure we haven't run out of data yet */
+      if (buf > endptr)
+      {
+         png_warning(png_ptr, "Invalid pCAL data");
+         png_free(png_ptr, png_ptr->chunkdata);
+         png_ptr->chunkdata = NULL;
+         png_free(png_ptr, params);
+         return;
+      }
+   }
+   png_set_pCAL(png_ptr, info_ptr, png_ptr->chunkdata, X0, X1, type, nparams,
+      units, params);
+   png_free(png_ptr, png_ptr->chunkdata);
+   png_ptr->chunkdata = NULL;
+   png_free(png_ptr, params);
+}
+#endif
+#ifdef PNG_READ_sCAL_SUPPORTED
+/* Read the sCAL chunk */
+void /* PRIVATE */
+png_handle_sCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+   png_size_t slength, i;
+   int state;
+   png_debug(1, "in png_handle_sCAL");
+   if (!(png_ptr->mode & PNG_HAVE_IHDR))
+      png_error(png_ptr, "Missing IHDR before sCAL");
+   else if (png_ptr->mode & PNG_HAVE_IDAT)
+   {
+      png_warning(png_ptr, "Invalid sCAL after IDAT");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+   else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sCAL))
+   {
+      png_warning(png_ptr, "Duplicate sCAL chunk");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+   /* Need unit type, width, \0, height: minimum 4 bytes */
+   else if (length < 4)
+   {
+      png_warning(png_ptr, "sCAL chunk too short");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+   png_debug1(2, "Allocating and reading sCAL chunk data (%u bytes)",
+      length + 1);
+   png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
+   if (png_ptr->chunkdata == NULL)
+   {
+      png_warning(png_ptr, "Out of memory while processing sCAL chunk");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+   slength = length;
+   png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
+   png_ptr->chunkdata[slength] = 0x00; /* Null terminate the last string */
+   if (png_crc_finish(png_ptr, 0))
+   {
+      png_free(png_ptr, png_ptr->chunkdata);
+      png_ptr->chunkdata = NULL;
+      return;
+   }
+   /* Validate the unit. */
+   if (png_ptr->chunkdata[0] != 1 && png_ptr->chunkdata[0] != 2)
+   {
+      png_warning(png_ptr, "Invalid sCAL ignored: invalid unit");
+      png_free(png_ptr, png_ptr->chunkdata);
+      png_ptr->chunkdata = NULL;
+      return;
+   }
+   /* Validate the ASCII numbers, need two ASCII numbers separated by
+    * a '\0' and they need to fit exactly in the chunk data.
+    */
+   i = 1;
+   state = 0;
+   if (!png_check_fp_number(png_ptr->chunkdata, slength, &state, &i) ||
+       i >= slength || png_ptr->chunkdata[i++] != 0)
+      png_warning(png_ptr, "Invalid sCAL chunk ignored: bad width format");
+   else if (!PNG_FP_IS_POSITIVE(state))
+      png_warning(png_ptr, "Invalid sCAL chunk ignored: non-positive width");
+   else
+   {
+      png_size_t heighti = i;
+      state = 0;
+      if (!png_check_fp_number(png_ptr->chunkdata, slength, &state, &i) ||
+          i != slength)
+         png_warning(png_ptr, "Invalid sCAL chunk ignored: bad height format");
+      else if (!PNG_FP_IS_POSITIVE(state))
+         png_warning(png_ptr,
+            "Invalid sCAL chunk ignored: non-positive height");
+      else
+         /* This is the (only) success case. */
+         png_set_sCAL_s(png_ptr, info_ptr, png_ptr->chunkdata[0],
+            png_ptr->chunkdata+1, png_ptr->chunkdata+heighti);
+   }
+   /* Clean up - just free the temporarily allocated buffer. */
+   png_free(png_ptr, png_ptr->chunkdata);
+   png_ptr->chunkdata = NULL;
+}
+#endif
+#ifdef PNG_READ_tIME_SUPPORTED
+void /* PRIVATE */
+png_handle_tIME(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+   png_byte buf[7];
+   png_time mod_time;
+   png_debug(1, "in png_handle_tIME");
+   if (!(png_ptr->mode & PNG_HAVE_IHDR))
+      png_error(png_ptr, "Out of place tIME chunk");
+   else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tIME))
+   {
+      png_warning(png_ptr, "Duplicate tIME chunk");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+   if (png_ptr->mode & PNG_HAVE_IDAT)
+      png_ptr->mode |= PNG_AFTER_IDAT;
+   if (length != 7)
+   {
+      png_warning(png_ptr, "Incorrect tIME chunk length");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+   png_crc_read(png_ptr, buf, 7);
+   if (png_crc_finish(png_ptr, 0))
+      return;
+   mod_time.second = buf[6];
+   mod_time.minute = buf[5];
+   mod_time.hour = buf[4];
+   mod_time.day = buf[3];
+   mod_time.month = buf[2];
+   mod_time.year = png_get_uint_16(buf);
+   png_set_tIME(png_ptr, info_ptr, &mod_time);
+}
+#endif
+#ifdef PNG_READ_tEXt_SUPPORTED
+/* Note: this does not properly handle chunks that are > 64K under DOS */
+void /* PRIVATE */
+png_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+   png_textp text_ptr;
+   png_charp key;
+   png_charp text;
+   png_uint_32 skip = 0;
+   png_size_t slength;
+   int ret;
+   png_debug(1, "in png_handle_tEXt");
+#ifdef PNG_USER_LIMITS_SUPPORTED
+   if (png_ptr->user_chunk_cache_max != 0)
+   {
+      if (png_ptr->user_chunk_cache_max == 1)
+      {
+         png_crc_finish(png_ptr, length);
+         return;
+      }
+      if (--png_ptr->user_chunk_cache_max == 1)
+      {
+         png_warning(png_ptr, "No space in chunk cache for tEXt");
+         png_crc_finish(png_ptr, length);
+         return;
+      }
+   }
+#endif
+   if (!(png_ptr->mode & PNG_HAVE_IHDR))
+      png_error(png_ptr, "Missing IHDR before tEXt");
+   if (png_ptr->mode & PNG_HAVE_IDAT)
+      png_ptr->mode |= PNG_AFTER_IDAT;
+#ifdef PNG_MAX_MALLOC_64K
+   if (length > (png_uint_32)65535L)
+   {
+      png_warning(png_ptr, "tEXt chunk too large to fit in memory");
+      skip = length - (png_uint_32)65535L;
+      length = (png_uint_32)65535L;
+   }
+#endif
+   png_free(png_ptr, png_ptr->chunkdata);
+   png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
+   if (png_ptr->chunkdata == NULL)
+   {
+     png_warning(png_ptr, "No memory to process text chunk");
+     return;
+   }
+   slength = length;
+   png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
+   if (png_crc_finish(png_ptr, skip))
+   {
+      png_free(png_ptr, png_ptr->chunkdata);
+      png_ptr->chunkdata = NULL;
+      return;
+   }
+   key = png_ptr->chunkdata;
+   key[slength] = 0x00;
+   for (text = key; *text; text++)
+      /* Empty loop to find end of key */ ;
+   if (text != key + slength)
+      text++;
+   text_ptr = (png_textp)png_malloc_warn(png_ptr,
+       png_sizeof(png_text));
+   if (text_ptr == NULL)
+   {
+      png_warning(png_ptr, "Not enough memory to process text chunk");
+      png_free(png_ptr, png_ptr->chunkdata);
+      png_ptr->chunkdata = NULL;
+      return;
+   }
+   text_ptr->compression = PNG_TEXT_COMPRESSION_NONE;
+   text_ptr->key = key;
+   text_ptr->lang = NULL;
+   text_ptr->lang_key = NULL;
+   text_ptr->itxt_length = 0;
+   text_ptr->text = text;
+   text_ptr->text_length = png_strlen(text);
+   ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
+   png_free(png_ptr, png_ptr->chunkdata);
+   png_ptr->chunkdata = NULL;
+   png_free(png_ptr, text_ptr);
+   if (ret)
+      png_warning(png_ptr, "Insufficient memory to process text chunk");
+}
+#endif
+#ifdef PNG_READ_zTXt_SUPPORTED
+/* Note: this does not correctly handle chunks that are > 64K under DOS */
+void /* PRIVATE */
+png_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+   png_textp text_ptr;
+   png_charp text;
+   int comp_type;
+   int ret;
+   png_size_t slength, prefix_len, data_len;
+   png_debug(1, "in png_handle_zTXt");
+#ifdef PNG_USER_LIMITS_SUPPORTED
+   if (png_ptr->user_chunk_cache_max != 0)
+   {
+      if (png_ptr->user_chunk_cache_max == 1)
+      {
+         png_crc_finish(png_ptr, length);
+         return;
+      }
+      if (--png_ptr->user_chunk_cache_max == 1)
+      {
+         png_warning(png_ptr, "No space in chunk cache for zTXt");
+         png_crc_finish(png_ptr, length);
+         return;
+      }
+   }
+#endif
+   if (!(png_ptr->mode & PNG_HAVE_IHDR))
+      png_error(png_ptr, "Missing IHDR before zTXt");
+   if (png_ptr->mode & PNG_HAVE_IDAT)
+      png_ptr->mode |= PNG_AFTER_IDAT;
+#ifdef PNG_MAX_MALLOC_64K
+   /* We will no doubt have problems with chunks even half this size, but
+    * there is no hard and fast rule to tell us where to stop.
+    */
+   if (length > (png_uint_32)65535L)
+   {
+      png_warning(png_ptr, "zTXt chunk too large to fit in memory");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+#endif
+   png_free(png_ptr, png_ptr->chunkdata);
+   png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
+   if (png_ptr->chunkdata == NULL)
+   {
+      png_warning(png_ptr, "Out of memory processing zTXt chunk");
+      return;
+   }
+   slength = length;
+   png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
+   if (png_crc_finish(png_ptr, 0))
+   {
+      png_free(png_ptr, png_ptr->chunkdata);
+      png_ptr->chunkdata = NULL;
+      return;
+   }
+   png_ptr->chunkdata[slength] = 0x00;
+   for (text = png_ptr->chunkdata; *text; text++)
+      /* Empty loop */ ;
+   /* zTXt must have some text after the chunkdataword */
+   if (text >= png_ptr->chunkdata + slength - 2)
+   {
+      png_warning(png_ptr, "Truncated zTXt chunk");
+      png_free(png_ptr, png_ptr->chunkdata);
+      png_ptr->chunkdata = NULL;
+      return;
+   }
+   else
+   {
+       comp_type = *(++text);
+       if (comp_type != PNG_TEXT_COMPRESSION_zTXt)
+       {
+          png_warning(png_ptr, "Unknown compression type in zTXt chunk");
+          comp_type = PNG_TEXT_COMPRESSION_zTXt;
+       }
+       text++;        /* Skip the compression_method byte */
+   }
+   prefix_len = text - png_ptr->chunkdata;
+   png_decompress_chunk(png_ptr, comp_type,
+       (png_size_t)length, prefix_len, &data_len);
+   text_ptr = (png_textp)png_malloc_warn(png_ptr,
+       png_sizeof(png_text));
+   if (text_ptr == NULL)
+   {
+      png_warning(png_ptr, "Not enough memory to process zTXt chunk");
+      png_free(png_ptr, png_ptr->chunkdata);
+      png_ptr->chunkdata = NULL;
+      return;
+   }
+   text_ptr->compression = comp_type;
+   text_ptr->key = png_ptr->chunkdata;
+   text_ptr->lang = NULL;
+   text_ptr->lang_key = NULL;
+   text_ptr->itxt_length = 0;
+   text_ptr->text = png_ptr->chunkdata + prefix_len;
+   text_ptr->text_length = data_len;
+   ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
+   png_free(png_ptr, text_ptr);
+   png_free(png_ptr, png_ptr->chunkdata);
+   png_ptr->chunkdata = NULL;
+   if (ret)
+      png_error(png_ptr, "Insufficient memory to store zTXt chunk");
+}
+#endif
+#ifdef PNG_READ_iTXt_SUPPORTED
+/* Note: this does not correctly handle chunks that are > 64K under DOS */
+void /* PRIVATE */
+png_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+   png_textp text_ptr;
+   png_charp key, lang, text, lang_key;
+   int comp_flag;
+   int comp_type = 0;
+   int ret;
+   png_size_t slength, prefix_len, data_len;
+   png_debug(1, "in png_handle_iTXt");
+#ifdef PNG_USER_LIMITS_SUPPORTED
+   if (png_ptr->user_chunk_cache_max != 0)
+   {
+      if (png_ptr->user_chunk_cache_max == 1)
+      {
+         png_crc_finish(png_ptr, length);
+         return;
+      }
+      if (--png_ptr->user_chunk_cache_max == 1)
+      {
+         png_warning(png_ptr, "No space in chunk cache for iTXt");
+         png_crc_finish(png_ptr, length);
+         return;
+      }
+   }
+#endif
+   if (!(png_ptr->mode & PNG_HAVE_IHDR))
+      png_error(png_ptr, "Missing IHDR before iTXt");
+   if (png_ptr->mode & PNG_HAVE_IDAT)
+      png_ptr->mode |= PNG_AFTER_IDAT;
+#ifdef PNG_MAX_MALLOC_64K
+   /* We will no doubt have problems with chunks even half this size, but
+    * there is no hard and fast rule to tell us where to stop.
+    */
+   if (length > (png_uint_32)65535L)
+   {
+      png_warning(png_ptr, "iTXt chunk too large to fit in memory");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+#endif
+   png_free(png_ptr, png_ptr->chunkdata);
+   png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
+   if (png_ptr->chunkdata == NULL)
+   {
+      png_warning(png_ptr, "No memory to process iTXt chunk");
+      return;
+   }
+   slength = length;
+   png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
+   if (png_crc_finish(png_ptr, 0))
+   {
+      png_free(png_ptr, png_ptr->chunkdata);
+      png_ptr->chunkdata = NULL;
+      return;
+   }
+   png_ptr->chunkdata[slength] = 0x00;
+   for (lang = png_ptr->chunkdata; *lang; lang++)
+      /* Empty loop */ ;
+   lang++;        /* Skip NUL separator */
+   /* iTXt must have a language tag (possibly empty), two compression bytes,
+    * translated keyword (possibly empty), and possibly some text after the
+    * keyword
+    */
+   if (lang >= png_ptr->chunkdata + slength - 3)
+   {
+      png_warning(png_ptr, "Truncated iTXt chunk");
+      png_free(png_ptr, png_ptr->chunkdata);
+      png_ptr->chunkdata = NULL;
+      return;
+   }
+   else
+   {
+      comp_flag = *lang++;
+      comp_type = *lang++;
+   }
+   if (comp_type || (comp_flag && comp_flag != PNG_TEXT_COMPRESSION_zTXt))
+   {
+      png_warning(png_ptr, "Unknown iTXt compression type or method");
+      png_free(png_ptr, png_ptr->chunkdata);
+      png_ptr->chunkdata = NULL;
+      return;
+   }
+   for (lang_key = lang; *lang_key; lang_key++)
+      /* Empty loop */ ;
+   lang_key++;        /* Skip NUL separator */
+   if (lang_key >= png_ptr->chunkdata + slength)
+   {
+      png_warning(png_ptr, "Truncated iTXt chunk");
+      png_free(png_ptr, png_ptr->chunkdata);
+      png_ptr->chunkdata = NULL;
+      return;
+   }
+   for (text = lang_key; *text; text++)
+      /* Empty loop */ ;
+   text++;        /* Skip NUL separator */
+   if (text >= png_ptr->chunkdata + slength)
+   {
+      png_warning(png_ptr, "Malformed iTXt chunk");
+      png_free(png_ptr, png_ptr->chunkdata);
+      png_ptr->chunkdata = NULL;
+      return;
+   }
+   prefix_len = text - png_ptr->chunkdata;
+   key=png_ptr->chunkdata;
+   if (comp_flag)
+      png_decompress_chunk(png_ptr, comp_type,
+          (size_t)length, prefix_len, &data_len);
+   else
+      data_len = png_strlen(png_ptr->chunkdata + prefix_len);
+   text_ptr = (png_textp)png_malloc_warn(png_ptr,
+       png_sizeof(png_text));
+   if (text_ptr == NULL)
+   {
+      png_warning(png_ptr, "Not enough memory to process iTXt chunk");
+      png_free(png_ptr, png_ptr->chunkdata);
+      png_ptr->chunkdata = NULL;
+      return;
+   }
+   text_ptr->compression = (int)comp_flag + 1;
+   text_ptr->lang_key = png_ptr->chunkdata + (lang_key - key);
+   text_ptr->lang = png_ptr->chunkdata + (lang - key);
+   text_ptr->itxt_length = data_len;
+   text_ptr->text_length = 0;
+   text_ptr->key = png_ptr->chunkdata;
+   text_ptr->text = png_ptr->chunkdata + prefix_len;
+   ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
+   png_free(png_ptr, text_ptr);
+   png_free(png_ptr, png_ptr->chunkdata);
+   png_ptr->chunkdata = NULL;
+   if (ret)
+      png_error(png_ptr, "Insufficient memory to store iTXt chunk");
+}
+#endif
+/* This function is called when we haven't found a handler for a
+ * chunk.  If there isn't a problem with the chunk itself (ie bad
+ * chunk name, CRC, or a critical chunk), the chunk is silently ignored
+ * -- unless the PNG_FLAG_UNKNOWN_CHUNKS_SUPPORTED flag is on in which
+ * case it will be saved away to be written out later.
+ */
+void /* PRIVATE */
+png_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+   png_uint_32 skip = 0;
+   png_debug(1, "in png_handle_unknown");
+#ifdef PNG_USER_LIMITS_SUPPORTED
+   if (png_ptr->user_chunk_cache_max != 0)
+   {
+      if (png_ptr->user_chunk_cache_max == 1)
+      {
+         png_crc_finish(png_ptr, length);
+         return;
+      }
+      if (--png_ptr->user_chunk_cache_max == 1)
+      {
+         png_warning(png_ptr, "No space in chunk cache for unknown chunk");
+         png_crc_finish(png_ptr, length);
+         return;
+      }
+   }
+#endif
+   if (png_ptr->mode & PNG_HAVE_IDAT)
+   {
+      if (png_ptr->chunk_name != png_IDAT)
+         png_ptr->mode |= PNG_AFTER_IDAT;
+   }
+   if (PNG_CHUNK_CRITICAL(png_ptr->chunk_name))
+   {
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+      if (png_chunk_unknown_handling(png_ptr, png_ptr->chunk_name) !=
+          PNG_HANDLE_CHUNK_ALWAYS
+#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
+          && png_ptr->read_user_chunk_fn == NULL
+#endif
+          )
+#endif
+         png_chunk_error(png_ptr, "unknown critical chunk");
+   }
+#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+   if ((png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS)
+#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
+       || (png_ptr->read_user_chunk_fn != NULL)
+#endif
+       )
+   {
+#ifdef PNG_MAX_MALLOC_64K
+      if (length > 65535)
+      {
+         png_warning(png_ptr, "unknown chunk too large to fit in memory");
+         skip = length - 65535;
+         length = 65535;
+      }
+#endif
+      /* TODO: this code is very close to the unknown handling in pngpread.c,
+       * maybe it can be put into a common utility routine?
+       * png_struct::unknown_chunk is just used as a temporary variable, along
+       * with the data into which the chunk is read.  These can be eliminated.
+       */
+      PNG_CSTRING_FROM_CHUNK(png_ptr->unknown_chunk.name, png_ptr->chunk_name);
+      png_ptr->unknown_chunk.size = (png_size_t)length;
+      if (length == 0)
+         png_ptr->unknown_chunk.data = NULL;
+      else
+      {
+         png_ptr->unknown_chunk.data = (png_bytep)png_malloc(png_ptr, length);
+         png_crc_read(png_ptr, png_ptr->unknown_chunk.data, length);
+      }
+#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
+      if (png_ptr->read_user_chunk_fn != NULL)
+      {
+         /* Callback to user unknown chunk handler */
+         int ret;
+         ret = (*(png_ptr->read_user_chunk_fn))
+             (png_ptr, &png_ptr->unknown_chunk);
+         if (ret < 0)
+            png_chunk_error(png_ptr, "error in user chunk");
+         if (ret == 0)
+         {
+            if (PNG_CHUNK_CRITICAL(png_ptr->chunk_name))
+            {
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+               if (png_chunk_unknown_handling(png_ptr, png_ptr->chunk_name) !=
+                   PNG_HANDLE_CHUNK_ALWAYS)
+#endif
+                  png_chunk_error(png_ptr, "unknown critical chunk");
+            }
+            png_set_unknown_chunks(png_ptr, info_ptr,
+                &png_ptr->unknown_chunk, 1);
+         }
+      }
+      else
+#endif
+         png_set_unknown_chunks(png_ptr, info_ptr, &png_ptr->unknown_chunk, 1);
+      png_free(png_ptr, png_ptr->unknown_chunk.data);
+      png_ptr->unknown_chunk.data = NULL;
+   }
+   else
+#endif
+      skip = length;
+   png_crc_finish(png_ptr, skip);
+#ifndef PNG_READ_USER_CHUNKS_SUPPORTED
+   PNG_UNUSED(info_ptr) /* Quiet compiler warnings about unused info_ptr */
+#endif
+}
+/* This function is called to verify that a chunk name is valid.
+ * This function can't have the "critical chunk check" incorporated
+ * into it, since in the future we will need to be able to call user
+ * functions to handle unknown critical chunks after we check that
+ * the chunk name itself is valid.
+ */
+/* Bit hacking: the test for an invalid byte in the 4 byte chunk name is:
+ *
+ * ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97))
+ */
+void /* PRIVATE */
+png_check_chunk_name(png_structp png_ptr, png_uint_32 chunk_name)
+{
+   int i;
+   png_debug(1, "in png_check_chunk_name");
+   for (i=1; i<=4; ++i)
+   {
+      int c = chunk_name & 0xff;
+      if (c < 65 || c > 122 || (c > 90 && c < 97))
+         png_chunk_error(png_ptr, "invalid chunk type");
+      chunk_name >>= 8;
+   }
+}
+/* Combines the row recently read in with the existing pixels in the row.  This
+ * routine takes care of alpha and transparency if requested.  This routine also
+ * handles the two methods of progressive display of interlaced images,
+ * depending on the 'display' value; if 'display' is true then the whole row
+ * (dp) is filled from the start by replicating the available pixels.  If
+ * 'display' is false only those pixels present in the pass are filled in.
+ */
+void /* PRIVATE */
+png_combine_row(png_structp png_ptr, png_bytep dp, int display)
+{
+   unsigned int pixel_depth = png_ptr->transformed_pixel_depth;
+   png_const_bytep sp = png_ptr->row_buf + 1;
+   png_uint_32 row_width = png_ptr->width;
+   unsigned int pass = png_ptr->pass;
+   png_bytep end_ptr = 0;
+   png_byte end_byte = 0;
+   unsigned int end_mask;
+   png_debug(1, "in png_combine_row");
+   /* Added in 1.5.6: it should not be possible to enter this routine until at
+    * least one row has been read from the PNG data and transformed.
+    */
+   if (pixel_depth == 0)
+      png_error(png_ptr, "internal row logic error");
+   /* Added in 1.5.4: the pixel depth should match the information returned by
+    * any call to png_read_update_info at this point.  Do not continue if we got
+    * this wrong.
+    */
+   if (png_ptr->info_rowbytes != 0 && png_ptr->info_rowbytes !=
+          PNG_ROWBYTES(pixel_depth, row_width))
+      png_error(png_ptr, "internal row size calculation error");
+   /* Don't expect this to ever happen: */
+   if (row_width == 0)
+      png_error(png_ptr, "internal row width error");
+   /* Preserve the last byte in cases where only part of it will be overwritten,
+    * the multiply below may overflow, we don't care because ANSI-C guarantees
+    * we get the low bits.
+    */
+   end_mask = (pixel_depth * row_width) & 7;
+   if (end_mask != 0)
+   {
+      /* end_ptr == NULL is a flag to say do nothing */
+      end_ptr = dp + PNG_ROWBYTES(pixel_depth, row_width) - 1;
+      end_byte = *end_ptr;
+#     ifdef PNG_READ_PACKSWAP_SUPPORTED
+         if (png_ptr->transformations & PNG_PACKSWAP) /* little-endian byte */
+            end_mask = 0xff << end_mask;
+         else /* big-endian byte */
+#     endif
+         end_mask = 0xff >> end_mask;
+      /* end_mask is now the bits to *keep* from the destination row */
+   }
+   /* For non-interlaced images this reduces to a png_memcpy(). A png_memcpy()
+    * will also happen if interlacing isn't supported or if the application
+    * does not call png_set_interlace_handling().  In the latter cases the
+    * caller just gets a sequence of the unexpanded rows from each interlace
+    * pass.
+    */
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+   if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE) &&
+      pass < 6 && (display == 0 ||
+      /* The following copies everything for 'display' on passes 0, 2 and 4. */
+      (display == 1 && (pass & 1) != 0)))
+   {
+      /* Narrow images may have no bits in a pass; the caller should handle
+       * this, but this test is cheap:
+       */
+      if (row_width <= PNG_PASS_START_COL(pass))
+         return;
+      if (pixel_depth < 8)
+      {
+         /* For pixel depths up to 4 bpp the 8-pixel mask can be expanded to fit
+          * into 32 bits, then a single loop over the bytes using the four byte
+          * values in the 32-bit mask can be used.  For the 'display' option the
+          * expanded mask may also not require any masking within a byte.  To
+          * make this work the PACKSWAP option must be taken into account - it
+          * simply requires the pixels to be reversed in each byte.
+          *
+          * The 'regular' case requires a mask for each of the first 6 passes,
+          * the 'display' case does a copy for the even passes in the range
+          * 0..6.  This has already been handled in the test above.
+          *
+          * The masks are arranged as four bytes with the first byte to use in
+          * the lowest bits (little-endian) regardless of the order (PACKSWAP or
+          * not) of the pixels in each byte.
+          *
+          * NOTE: the whole of this logic depends on the caller of this function
+          * only calling it on rows appropriate to the pass.  This function only
+          * understands the 'x' logic; the 'y' logic is handled by the caller.
+          *
+          * The following defines allow generation of compile time constant bit
+          * masks for each pixel depth and each possibility of swapped or not
+          * swapped bytes.  Pass 'p' is in the range 0..6; 'x', a pixel index,
+          * is in the range 0..7; and the result is 1 if the pixel is to be
+          * copied in the pass, 0 if not.  'S' is for the sparkle method, 'B'
+          * for the block method.
+          *
+          * With some compilers a compile time expression of the general form:
+          *
+          *    (shift >= 32) ? (a >> (shift-32)) : (b >> shift)
+          *
+          * Produces warnings with values of 'shift' in the range 33 to 63
+          * because the right hand side of the ?: expression is evaluated by
+          * the compiler even though it isn't used.  Microsoft Visual C (various
+          * versions) and the Intel C compiler are known to do this.  To avoid
+          * this the following macros are used in 1.5.6.  This is a temporary
+          * solution to avoid destabilizing the code during the release process.
+          */
+#        if PNG_USE_COMPILE_TIME_MASKS
+#           define PNG_LSR(x,s) ((x)>>((s) & 0x1f))
+#           define PNG_LSL(x,s) ((x)<<((s) & 0x1f))
+#        else
+#           define PNG_LSR(x,s) ((x)>>(s))
+#           define PNG_LSL(x,s) ((x)<<(s))
+#        endif
+#        define S_COPY(p,x) (((p)<4 ? PNG_LSR(0x80088822,(3-(p))*8+(7-(x))) :\
+           PNG_LSR(0xaa55ff00,(7-(p))*8+(7-(x)))) & 1)
+#        define B_COPY(p,x) (((p)<4 ? PNG_LSR(0xff0fff33,(3-(p))*8+(7-(x))) :\
+           PNG_LSR(0xff55ff00,(7-(p))*8+(7-(x)))) & 1)
+         /* Return a mask for pass 'p' pixel 'x' at depth 'd'.  The mask is
+          * little endian - the first pixel is at bit 0 - however the extra
+          * parameter 's' can be set to cause the mask position to be swapped
+          * within each byte, to match the PNG format.  This is done by XOR of
+          * the shift with 7, 6 or 4 for bit depths 1, 2 and 4.
+          */
+#        define PIXEL_MASK(p,x,d,s) \
+            (PNG_LSL(((PNG_LSL(1U,(d)))-1),(((x)*(d))^((s)?8-(d):0))))
+         /* Hence generate the appropriate 'block' or 'sparkle' pixel copy mask.
+          */
+#        define S_MASKx(p,x,d,s) (S_COPY(p,x)?PIXEL_MASK(p,x,d,s):0)
+#        define B_MASKx(p,x,d,s) (B_COPY(p,x)?PIXEL_MASK(p,x,d,s):0)
+         /* Combine 8 of these to get the full mask.  For the 1-bpp and 2-bpp
+          * cases the result needs replicating, for the 4-bpp case the above
+          * generates a full 32 bits.
+          */
+#        define MASK_EXPAND(m,d) ((m)*((d)==1?0x01010101:((d)==2?0x00010001:1)))
+#        define S_MASK(p,d,s) MASK_EXPAND(S_MASKx(p,0,d,s) + S_MASKx(p,1,d,s) +\
+            S_MASKx(p,2,d,s) + S_MASKx(p,3,d,s) + S_MASKx(p,4,d,s) +\
+            S_MASKx(p,5,d,s) + S_MASKx(p,6,d,s) + S_MASKx(p,7,d,s), d)
+#        define B_MASK(p,d,s) MASK_EXPAND(B_MASKx(p,0,d,s) + B_MASKx(p,1,d,s) +\
+            B_MASKx(p,2,d,s) + B_MASKx(p,3,d,s) + B_MASKx(p,4,d,s) +\
+            B_MASKx(p,5,d,s) + B_MASKx(p,6,d,s) + B_MASKx(p,7,d,s), d)
+#if PNG_USE_COMPILE_TIME_MASKS
+         /* Utility macros to construct all the masks for a depth/swap
+          * combination.  The 's' parameter says whether the format is PNG
+          * (big endian bytes) or not.  Only the three odd-numbered passes are
+          * required for the display/block algorithm.
+          */
+#        define S_MASKS(d,s) { S_MASK(0,d,s), S_MASK(1,d,s), S_MASK(2,d,s),\
+            S_MASK(3,d,s), S_MASK(4,d,s), S_MASK(5,d,s) }
+#        define B_MASKS(d,s) { B_MASK(1,d,s), S_MASK(3,d,s), S_MASK(5,d,s) }
+#        define DEPTH_INDEX(d) ((d)==1?0:((d)==2?1:2))
+         /* Hence the pre-compiled masks indexed by PACKSWAP (or not), depth and
+          * then pass:
+          */
+         static PNG_CONST png_uint_32 row_mask[2/*PACKSWAP*/][3/*depth*/][6] =
+         {
+            /* Little-endian byte masks for PACKSWAP */
+            { S_MASKS(1,0), S_MASKS(2,0), S_MASKS(4,0) },
+            /* Normal (big-endian byte) masks - PNG format */
+            { S_MASKS(1,1), S_MASKS(2,1), S_MASKS(4,1) }
+         };
+         /* display_mask has only three entries for the odd passes, so index by
+          * pass>>1.
+          */
+         static PNG_CONST png_uint_32 display_mask[2][3][3] =
+         {
+            /* Little-endian byte masks for PACKSWAP */
+            { B_MASKS(1,0), B_MASKS(2,0), B_MASKS(4,0) },
+            /* Normal (big-endian byte) masks - PNG format */
+            { B_MASKS(1,1), B_MASKS(2,1), B_MASKS(4,1) }
+         };
+#        define MASK(pass,depth,display,png)\
+            ((display)?display_mask[png][DEPTH_INDEX(depth)][pass>>1]:\
+               row_mask[png][DEPTH_INDEX(depth)][pass])
+#else /* !PNG_USE_COMPILE_TIME_MASKS */
+         /* This is the runtime alternative: it seems unlikely that this will
+          * ever be either smaller or faster than the compile time approach.
+          */
+#        define MASK(pass,depth,display,png)\
+            ((display)?B_MASK(pass,depth,png):S_MASK(pass,depth,png))
+#endif /* !PNG_USE_COMPILE_TIME_MASKS */
+         /* Use the appropriate mask to copy the required bits.  In some cases
+          * the byte mask will be 0 or 0xff, optimize these cases.  row_width is
+          * the number of pixels, but the code copies bytes, so it is necessary
+          * to special case the end.
+          */
+         png_uint_32 pixels_per_byte = 8 / pixel_depth;
+         png_uint_32 mask;
+#        ifdef PNG_READ_PACKSWAP_SUPPORTED
+            if (png_ptr->transformations & PNG_PACKSWAP)
+               mask = MASK(pass, pixel_depth, display, 0);
+            else
+#        endif
+            mask = MASK(pass, pixel_depth, display, 1);
+         for (;;)
+         {
+            png_uint_32 m;
+            /* It doesn't matter in the following if png_uint_32 has more than
+             * 32 bits because the high bits always match those in m<<24; it is,
+             * however, essential to use OR here, not +, because of this.
+             */
+            m = mask;
+            mask = (m >> 8) | (m << 24); /* rotate right to good compilers */
+            m &= 0xff;
+            if (m != 0) /* something to copy */
+            {
+               if (m != 0xff)
+                  *dp = (png_byte)((*dp & ~m) | (*sp & m));
+               else
+                  *dp = *sp;
+            }
+            /* NOTE: this may overwrite the last byte with garbage if the image
+             * is not an exact number of bytes wide; libpng has always done
+             * this.
+             */
+            if (row_width <= pixels_per_byte)
+               break; /* May need to restore part of the last byte */
+            row_width -= pixels_per_byte;
+            ++dp;
+            ++sp;
+         }
+      }
+      else /* pixel_depth >= 8 */
+      {
+         unsigned int bytes_to_copy, bytes_to_jump;
+         /* Validate the depth - it must be a multiple of 8 */
+         if (pixel_depth & 7)
+            png_error(png_ptr, "invalid user transform pixel depth");
+         pixel_depth >>= 3; /* now in bytes */
+         row_width *= pixel_depth;
+         /* Regardless of pass number the Adam 7 interlace always results in a
+          * fixed number of pixels to copy then to skip.  There may be a
+          * different number of pixels to skip at the start though.
+          */
+         {
+            unsigned int offset = PNG_PASS_START_COL(pass) * pixel_depth;
+            row_width -= offset;
+            dp += offset;
+            sp += offset;
+         }
+         /* Work out the bytes to copy. */
+         if (display)
+         {
+            /* When doing the 'block' algorithm the pixel in the pass gets
+             * replicated to adjacent pixels.  This is why the even (0,2,4,6)
+             * passes are skipped above - the entire expanded row is copied.
+             */
+            bytes_to_copy = (1<<((6-pass)>>1)) * pixel_depth;
+            /* But don't allow this number to exceed the actual row width. */
+            if (bytes_to_copy > row_width)
+               bytes_to_copy = row_width;
+         }
+         else /* normal row; Adam7 only ever gives us one pixel to copy. */
+            bytes_to_copy = pixel_depth;
+         /* In Adam7 there is a constant offset between where the pixels go. */
+         bytes_to_jump = PNG_PASS_COL_OFFSET(pass) * pixel_depth;
+         /* And simply copy these bytes.  Some optimization is possible here,
+          * depending on the value of 'bytes_to_copy'.  Special case the low
+          * byte counts, which we know to be frequent.
+          *
+          * Notice that these cases all 'return' rather than 'break' - this
+          * avoids an unnecessary test on whether to restore the last byte
+          * below.
+          */
+         switch (bytes_to_copy)
+         {
+            case 1:
+               for (;;)
+               {
+                  *dp = *sp;
+                  if (row_width <= bytes_to_jump)
+                     return;
+                  dp += bytes_to_jump;
+                  sp += bytes_to_jump;
+                  row_width -= bytes_to_jump;
+               }
+            case 2:
+               /* There is a possibility of a partial copy at the end here; this
+                * slows the code down somewhat.
+                */
+               do
+               {
+                  dp[0] = sp[0], dp[1] = sp[1];
+                  if (row_width <= bytes_to_jump)
+                     return;
+                  sp += bytes_to_jump;
+                  dp += bytes_to_jump;
+                  row_width -= bytes_to_jump;
+               }
+               while (row_width > 1);
+               /* And there can only be one byte left at this point: */
+               *dp = *sp;
+               return;
+            case 3:
+               /* This can only be the RGB case, so each copy is exactly one
+                * pixel and it is not necessary to check for a partial copy.
+                */
+               for(;;)
+               {
+                  dp[0] = sp[0], dp[1] = sp[1], dp[2] = sp[2];
+                  if (row_width <= bytes_to_jump)
+                     return;
+                  sp += bytes_to_jump;
+                  dp += bytes_to_jump;
+                  row_width -= bytes_to_jump;
+               }
+            default:
+#if PNG_ALIGN_TYPE != PNG_ALIGN_NONE
+               /* Check for double byte alignment and, if possible, use a
+                * 16-bit copy.  Don't attempt this for narrow images - ones that
+                * are less than an interlace panel wide.  Don't attempt it for
+                * wide bytes_to_copy either - use the png_memcpy there.
+                */
+               if (bytes_to_copy < 16 /*else use png_memcpy*/ &&
+                  png_isaligned(dp, png_uint_16) &&
+                  png_isaligned(sp, png_uint_16) &&
+                  bytes_to_copy % sizeof (png_uint_16) == 0 &&
+                  bytes_to_jump % sizeof (png_uint_16) == 0)
+               {
+                  /* Everything is aligned for png_uint_16 copies, but try for
+                   * png_uint_32 first.
+                   */
+                  if (png_isaligned(dp, png_uint_32) &&
+                     png_isaligned(sp, png_uint_32) &&
+                     bytes_to_copy % sizeof (png_uint_32) == 0 &&
+                     bytes_to_jump % sizeof (png_uint_32) == 0)
+                  {
+                     png_uint_32p dp32 = (png_uint_32p)dp;
+                     png_const_uint_32p sp32 = (png_const_uint_32p)sp;
+                     unsigned int skip = (bytes_to_jump-bytes_to_copy) /
+                        sizeof (png_uint_32);
+                     do
+                     {
+                        size_t c = bytes_to_copy;
+                        do
+                        {
+                           *dp32++ = *sp32++;
+                           c -= sizeof (png_uint_32);
+                        }
+                        while (c > 0);
+                        if (row_width <= bytes_to_jump)
+                           return;
+                        dp32 += skip;
+                        sp32 += skip;
+                        row_width -= bytes_to_jump;
+                     }
+                     while (bytes_to_copy <= row_width);
+                     /* Get to here when the row_width truncates the final copy.
+                      * There will be 1-3 bytes left to copy, so don't try the
+                      * 16-bit loop below.
+                      */
+                     dp = (png_bytep)dp32;
+                     sp = (png_const_bytep)sp32;
+                     do
+                        *dp++ = *sp++;
+                     while (--row_width > 0);
+                     return;
+                  }
+                  /* Else do it in 16-bit quantities, but only if the size is
+                   * not too large.
+                   */
+                  else
+                  {
+                     png_uint_16p dp16 = (png_uint_16p)dp;
+                     png_const_uint_16p sp16 = (png_const_uint_16p)sp;
+                     unsigned int skip = (bytes_to_jump-bytes_to_copy) /
+                        sizeof (png_uint_16);
+                     do
+                     {
+                        size_t c = bytes_to_copy;
+                        do
+                        {
+                           *dp16++ = *sp16++;
+                           c -= sizeof (png_uint_16);
+                        }
+                        while (c > 0);
+                        if (row_width <= bytes_to_jump)
+                           return;
+                        dp16 += skip;
+                        sp16 += skip;
+                        row_width -= bytes_to_jump;
+                     }
+                     while (bytes_to_copy <= row_width);
+                     /* End of row - 1 byte left, bytes_to_copy > row_width: */
+                     dp = (png_bytep)dp16;
+                     sp = (png_const_bytep)sp16;
+                     do
+                        *dp++ = *sp++;
+                     while (--row_width > 0);
+                     return;
+                  }
+               }
+#endif /* PNG_ALIGN_ code */
+               /* The true default - use a png_memcpy: */
+               for (;;)
+               {
+                  png_memcpy(dp, sp, bytes_to_copy);
+                  if (row_width <= bytes_to_jump)
+                     return;
+                  sp += bytes_to_jump;
+                  dp += bytes_to_jump;
+                  row_width -= bytes_to_jump;
+                  if (bytes_to_copy > row_width)
+                     bytes_to_copy = row_width;
+               }
+         }
+         /* NOT REACHED*/
+      } /* pixel_depth >= 8 */
+      /* Here if pixel_depth < 8 to check 'end_ptr' below. */
+   }
+   else
+#endif
+   /* If here then the switch above wasn't used so just png_memcpy the whole row
+    * from the temporary row buffer (notice that this overwrites the end of the
+    * destination row if it is a partial byte.)
+    */
+   png_memcpy(dp, sp, PNG_ROWBYTES(pixel_depth, row_width));
+   /* Restore the overwritten bits from the last byte if necessary. */
+   if (end_ptr != NULL)
+      *end_ptr = (png_byte)((end_byte & end_mask) | (*end_ptr & ~end_mask));
+}
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+void /* PRIVATE */
+png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass,
+   png_uint_32 transformations /* Because these may affect the byte layout */)
+{
+   /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+   /* Offset to next interlace block */
+   static PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+   png_debug(1, "in png_do_read_interlace");
+   if (row != NULL && row_info != NULL)
+   {
+      png_uint_32 final_width;
+      final_width = row_info->width * png_pass_inc[pass];
+      switch (row_info->pixel_depth)
+      {
+         case 1:
+         {
+            png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 3);
+            png_bytep dp = row + (png_size_t)((final_width - 1) >> 3);
+            int sshift, dshift;
+            int s_start, s_end, s_inc;
+            int jstop = png_pass_inc[pass];
+            png_byte v;
+            png_uint_32 i;
+            int j;
+#ifdef PNG_READ_PACKSWAP_SUPPORTED
+            if (transformations & PNG_PACKSWAP)
+            {
+                sshift = (int)((row_info->width + 7) & 0x07);
+                dshift = (int)((final_width + 7) & 0x07);
+                s_start = 7;
+                s_end = 0;
+                s_inc = -1;
+            }
+            else
+#endif
+            {
+                sshift = 7 - (int)((row_info->width + 7) & 0x07);
+                dshift = 7 - (int)((final_width + 7) & 0x07);
+                s_start = 0;
+                s_end = 7;
+                s_inc = 1;
+            }
+            for (i = 0; i < row_info->width; i++)
+            {
+               v = (png_byte)((*sp >> sshift) & 0x01);
+               for (j = 0; j < jstop; j++)
+               {
+                  *dp &= (png_byte)((0x7f7f >> (7 - dshift)) & 0xff);
+                  *dp |= (png_byte)(v << dshift);
+                  if (dshift == s_end)
+                  {
+                     dshift = s_start;
+                     dp--;
+                  }
+                  else
+                     dshift += s_inc;
+               }
+               if (sshift == s_end)
+               {
+                  sshift = s_start;
+                  sp--;
+               }
+               else
+                  sshift += s_inc;
+            }
+            break;
+         }
+         case 2:
+         {
+            png_bytep sp = row + (png_uint_32)((row_info->width - 1) >> 2);
+            png_bytep dp = row + (png_uint_32)((final_width - 1) >> 2);
+            int sshift, dshift;
+            int s_start, s_end, s_inc;
+            int jstop = png_pass_inc[pass];
+            png_uint_32 i;
+#ifdef PNG_READ_PACKSWAP_SUPPORTED
+            if (transformations & PNG_PACKSWAP)
+            {
+               sshift = (int)(((row_info->width + 3) & 0x03) << 1);
+               dshift = (int)(((final_width + 3) & 0x03) << 1);
+               s_start = 6;
+               s_end = 0;
+               s_inc = -2;
+            }
+            else
+#endif
+            {
+               sshift = (int)((3 - ((row_info->width + 3) & 0x03)) << 1);
+               dshift = (int)((3 - ((final_width + 3) & 0x03)) << 1);
+               s_start = 0;
+               s_end = 6;
+               s_inc = 2;
+            }
+            for (i = 0; i < row_info->width; i++)
+            {
+               png_byte v;
+               int j;
+               v = (png_byte)((*sp >> sshift) & 0x03);
+               for (j = 0; j < jstop; j++)
+               {
+                  *dp &= (png_byte)((0x3f3f >> (6 - dshift)) & 0xff);
+                  *dp |= (png_byte)(v << dshift);
+                  if (dshift == s_end)
+                  {
+                     dshift = s_start;
+                     dp--;
+                  }
+                  else
+                     dshift += s_inc;
+               }
+               if (sshift == s_end)
+               {
+                  sshift = s_start;
+                  sp--;
+               }
+               else
+                  sshift += s_inc;
+            }
+            break;
+         }
+         case 4:
+         {
+            png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 1);
+            png_bytep dp = row + (png_size_t)((final_width - 1) >> 1);
+            int sshift, dshift;
+            int s_start, s_end, s_inc;
+            png_uint_32 i;
+            int jstop = png_pass_inc[pass];
+#ifdef PNG_READ_PACKSWAP_SUPPORTED
+            if (transformations & PNG_PACKSWAP)
+            {
+               sshift = (int)(((row_info->width + 1) & 0x01) << 2);
+               dshift = (int)(((final_width + 1) & 0x01) << 2);
+               s_start = 4;
+               s_end = 0;
+               s_inc = -4;
+            }
+            else
+#endif
+            {
+               sshift = (int)((1 - ((row_info->width + 1) & 0x01)) << 2);
+               dshift = (int)((1 - ((final_width + 1) & 0x01)) << 2);
+               s_start = 0;
+               s_end = 4;
+               s_inc = 4;
+            }
+            for (i = 0; i < row_info->width; i++)
+            {
+               png_byte v = (png_byte)((*sp >> sshift) & 0x0f);
+               int j;
+               for (j = 0; j < jstop; j++)
+               {
+                  *dp &= (png_byte)((0xf0f >> (4 - dshift)) & 0xff);
+                  *dp |= (png_byte)(v << dshift);
+                  if (dshift == s_end)
+                  {
+                     dshift = s_start;
+                     dp--;
+                  }
+                  else
+                     dshift += s_inc;
+               }
+               if (sshift == s_end)
+               {
+                  sshift = s_start;
+                  sp--;
+               }
+               else
+                  sshift += s_inc;
+            }
+            break;
+         }
+         default:
+         {
+            png_size_t pixel_bytes = (row_info->pixel_depth >> 3);
+            png_bytep sp = row + (png_size_t)(row_info->width - 1)
+                * pixel_bytes;
+            png_bytep dp = row + (png_size_t)(final_width - 1) * pixel_bytes;
+            int jstop = png_pass_inc[pass];
+            png_uint_32 i;
+            for (i = 0; i < row_info->width; i++)
+            {
+               png_byte v[8];
+               int j;
+               png_memcpy(v, sp, pixel_bytes);
+               for (j = 0; j < jstop; j++)
+               {
+                  png_memcpy(dp, v, pixel_bytes);
+                  dp -= pixel_bytes;
+               }
+               sp -= pixel_bytes;
+            }
+            break;
+         }
+      }
+      row_info->width = final_width;
+      row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, final_width);
+   }
+#ifndef PNG_READ_PACKSWAP_SUPPORTED
+   PNG_UNUSED(transformations)  /* Silence compiler warning */
+#endif
+}
+#endif /* PNG_READ_INTERLACING_SUPPORTED */
+static void
+png_read_filter_row_sub(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev_row)
+{
+   png_size_t i;
+   png_size_t istop = row_info->rowbytes;
+   unsigned int bpp = (row_info->pixel_depth + 7) >> 3;
+   png_bytep rp = row + bpp;
+   PNG_UNUSED(prev_row)
+   for (i = bpp; i < istop; i++)
+   {
+      *rp = (png_byte)(((int)(*rp) + (int)(*(rp-bpp))) & 0xff);
+      rp++;
+   }
+}
+static void
+png_read_filter_row_up(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev_row)
+{
+   png_size_t i;
+   png_size_t istop = row_info->rowbytes;
+   png_bytep rp = row;
+   png_const_bytep pp = prev_row;
+   for (i = 0; i < istop; i++)
+   {
+      *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff);
+      rp++;
+   }
+}
+static void
+png_read_filter_row_avg(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev_row)
+{
+   png_size_t i;
+   png_bytep rp = row;
+   png_const_bytep pp = prev_row;
+   unsigned int bpp = (row_info->pixel_depth + 7) >> 3;
+   png_size_t istop = row_info->rowbytes - bpp;
+   for (i = 0; i < bpp; i++)
+   {
+      *rp = (png_byte)(((int)(*rp) +
+         ((int)(*pp++) / 2 )) & 0xff);
+      rp++;
+   }
+   for (i = 0; i < istop; i++)
+   {
+      *rp = (png_byte)(((int)(*rp) +
+         (int)(*pp++ + *(rp-bpp)) / 2 ) & 0xff);
+      rp++;
+   }
+}
+static void
+png_read_filter_row_paeth_1byte_pixel(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev_row)
+{
+   png_bytep rp_end = row + row_info->rowbytes;
+   int a, c;
+   /* First pixel/byte */
+   c = *prev_row++;
+   a = *row + c;
+   *row++ = (png_byte)a;
+   /* Remainder */
+   while (row < rp_end)
+   {
+      int b, pa, pb, pc, p;
+      a &= 0xff; /* From previous iteration or start */
+      b = *prev_row++;
+      p = b - c;
+      pc = a - c;
+#     ifdef PNG_USE_ABS
+         pa = abs(p);
+         pb = abs(pc);
+         pc = abs(p + pc);
+#     else
+         pa = p < 0 ? -p : p;
+         pb = pc < 0 ? -pc : pc;
+         pc = (p + pc) < 0 ? -(p + pc) : p + pc;
+#     endif
+      /* Find the best predictor, the least of pa, pb, pc favoring the earlier
+       * ones in the case of a tie.
+       */
+      if (pb < pa) pa = pb, a = b;
+      if (pc < pa) a = c;
+      /* Calculate the current pixel in a, and move the previous row pixel to c
+       * for the next time round the loop
+       */
+      c = b;
+      a += *row;
+      *row++ = (png_byte)a;
+   }
+}
+static void
+png_read_filter_row_paeth_multibyte_pixel(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev_row)
+{
+   int bpp = (row_info->pixel_depth + 7) >> 3;
+   png_bytep rp_end = row + bpp;
+   /* Process the first pixel in the row completely (this is the same as 'up'
+    * because there is only one candidate predictor for the first row).
+    */
+   while (row < rp_end)
+   {
+      int a = *row + *prev_row++;
+      *row++ = (png_byte)a;
+   }
+   /* Remainder */
+   rp_end += row_info->rowbytes - bpp;
+   while (row < rp_end)
+   {
+      int a, b, c, pa, pb, pc, p;
+      c = *(prev_row - bpp);
+      a = *(row - bpp);
+      b = *prev_row++;
+      p = b - c;
+      pc = a - c;
+#     ifdef PNG_USE_ABS
+         pa = abs(p);
+         pb = abs(pc);
+         pc = abs(p + pc);
+#     else
+         pa = p < 0 ? -p : p;
+         pb = pc < 0 ? -pc : pc;
+         pc = (p + pc) < 0 ? -(p + pc) : p + pc;
+#     endif
+      if (pb < pa) pa = pb, a = b;
+      if (pc < pa) a = c;
+      c = b;
+      a += *row;
+      *row++ = (png_byte)a;
+   }
+}
+#ifdef PNG_ARM_NEON
+#ifdef __linux__
+#include <stdio.h>
+#include <elf.h>
+#include <asm/hwcap.h>
+static int png_have_hwcap(unsigned cap)
+{
+   FILE *f = fopen("/proc/self/auxv", "r");
+   Elf32_auxv_t aux;
+   int have_cap = 0;
+   if (!f)
+      return 0;
+   while (fread(&aux, sizeof(aux), 1, f) > 0)
+   {
+      if (aux.a_type == AT_HWCAP &&
+          aux.a_un.a_val & cap)
+      {
+         have_cap = 1;
+         break;
+      }
+   }
+   fclose(f);
+   return have_cap;
+}
+#endif /* __linux__ */
+static void
+png_init_filter_functions_neon(png_structp pp, unsigned int bpp)
+{
+#ifdef __linux__
+   if (!png_have_hwcap(HWCAP_NEON))
+      return;
+#endif
+   pp->read_filter[PNG_FILTER_VALUE_UP-1] = png_read_filter_row_up_neon;
+   if (bpp == 3)
+   {
+      pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub3_neon;
+      pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg3_neon;
+      pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = 
+         png_read_filter_row_paeth3_neon;
+   }
+   else if (bpp == 4)
+   {
+      pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub4_neon;
+      pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg4_neon;
+      pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
+          png_read_filter_row_paeth4_neon;
+   }
+}
+#endif /* PNG_ARM_NEON */
+static void
+png_init_filter_functions(png_structp pp)
+{
+   unsigned int bpp = (pp->pixel_depth + 7) >> 3;
+   pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub;
+   pp->read_filter[PNG_FILTER_VALUE_UP-1] = png_read_filter_row_up;
+   pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg;
+   if (bpp == 1)
+      pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
+         png_read_filter_row_paeth_1byte_pixel;
+   else
+      pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
+         png_read_filter_row_paeth_multibyte_pixel;
+#ifdef PNG_ARM_NEON
+   png_init_filter_functions_neon(pp, bpp);
+#endif
+}
+void /* PRIVATE */
+png_read_filter_row(png_structp pp, png_row_infop row_info, png_bytep row,
+   png_const_bytep prev_row, int filter)
+{
+   if (pp->read_filter[0] == NULL)
+      png_init_filter_functions(pp);
+   if (filter > PNG_FILTER_VALUE_NONE && filter < PNG_FILTER_VALUE_LAST)
+      pp->read_filter[filter-1](row_info, row, prev_row);
+}
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+void /* PRIVATE */
+png_read_finish_row(png_structp png_ptr)
+{
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+   /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+   /* Start of interlace block */
+   static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
+   /* Offset to next interlace block */
+   static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+   /* Start of interlace block in the y direction */
+   static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
+   /* Offset to next interlace block in the y direction */
+   static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
+#endif /* PNG_READ_INTERLACING_SUPPORTED */
+   png_debug(1, "in png_read_finish_row");
+   png_ptr->row_number++;
+   if (png_ptr->row_number < png_ptr->num_rows)
+      return;
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+   if (png_ptr->interlaced)
+   {
+      png_ptr->row_number = 0;
+      /* TO DO: don't do this if prev_row isn't needed (requires
+       * read-ahead of the next row's filter byte.
+       */
+      png_memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
+      do
+      {
+         png_ptr->pass++;
+         if (png_ptr->pass >= 7)
+            break;
+         png_ptr->iwidth = (png_ptr->width +
+            png_pass_inc[png_ptr->pass] - 1 -
+            png_pass_start[png_ptr->pass]) /
+            png_pass_inc[png_ptr->pass];
+         if (!(png_ptr->transformations & PNG_INTERLACE))
+         {
+            png_ptr->num_rows = (png_ptr->height +
+                png_pass_yinc[png_ptr->pass] - 1 -
+                png_pass_ystart[png_ptr->pass]) /
+                png_pass_yinc[png_ptr->pass];
+         }
+         else  /* if (png_ptr->transformations & PNG_INTERLACE) */
+            break; /* libpng deinterlacing sees every row */
+      } while (png_ptr->num_rows == 0 || png_ptr->iwidth == 0);
+      if (png_ptr->pass < 7)
+         return;
+   }
+#endif /* PNG_READ_INTERLACING_SUPPORTED */
+   if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
+   {
+      char extra;
+      int ret;
+      png_ptr->zstream.next_out = (Byte *)&extra;
+      png_ptr->zstream.avail_out = (uInt)1;
+      for (;;)
+      {
+         if (!(png_ptr->zstream.avail_in))
+         {
+            while (!png_ptr->idat_size)
+            {
+               png_crc_finish(png_ptr, 0);
+               png_ptr->idat_size = png_read_chunk_header(png_ptr);
+               if (png_ptr->chunk_name != png_IDAT)
+                  png_error(png_ptr, "Not enough image data");
+            }
+            png_ptr->zstream.avail_in = (uInt)png_ptr->zbuf_size;
+            png_ptr->zstream.next_in = png_ptr->zbuf;
+            if (png_ptr->zbuf_size > png_ptr->idat_size)
+               png_ptr->zstream.avail_in = (uInt)png_ptr->idat_size;
+            png_crc_read(png_ptr, png_ptr->zbuf, png_ptr->zstream.avail_in);
+            png_ptr->idat_size -= png_ptr->zstream.avail_in;
+         }
+         ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
+         if (ret == Z_STREAM_END)
+         {
+            if (!(png_ptr->zstream.avail_out) || png_ptr->zstream.avail_in ||
+                png_ptr->idat_size)
+               png_warning(png_ptr, "Extra compressed data");
+            png_ptr->mode |= PNG_AFTER_IDAT;
+            png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
+            break;
+         }
+         if (ret != Z_OK)
+            png_error(png_ptr, png_ptr->zstream.msg ? png_ptr->zstream.msg :
+                "Decompression Error");
+         if (!(png_ptr->zstream.avail_out))
+         {
+            png_warning(png_ptr, "Extra compressed data");
+            png_ptr->mode |= PNG_AFTER_IDAT;
+            png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
+            break;
+         }
+      }
+      png_ptr->zstream.avail_out = 0;
+   }
+   if (png_ptr->idat_size || png_ptr->zstream.avail_in)
+      png_warning(png_ptr, "Extra compression data");
+   inflateReset(&png_ptr->zstream);
+   png_ptr->mode |= PNG_AFTER_IDAT;
+}
+#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
+void /* PRIVATE */
+png_read_start_row(png_structp png_ptr)
+{
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+   /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+   /* Start of interlace block */
+   static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
+   /* Offset to next interlace block */
+   static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+   /* Start of interlace block in the y direction */
+   static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
+   /* Offset to next interlace block in the y direction */
+   static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
+#endif
+   int max_pixel_depth;
+   png_size_t row_bytes;
+   png_debug(1, "in png_read_start_row");
+   png_ptr->zstream.avail_in = 0;
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+   png_init_read_transformations(png_ptr);
+#endif
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+   if (png_ptr->interlaced)
+   {
+      if (!(png_ptr->transformations & PNG_INTERLACE))
+         png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 -
+             png_pass_ystart[0]) / png_pass_yinc[0];
+      else
+         png_ptr->num_rows = png_ptr->height;
+      png_ptr->iwidth = (png_ptr->width +
+          png_pass_inc[png_ptr->pass] - 1 -
+          png_pass_start[png_ptr->pass]) /
+          png_pass_inc[png_ptr->pass];
+   }
+   else
+#endif /* PNG_READ_INTERLACING_SUPPORTED */
+   {
+      png_ptr->num_rows = png_ptr->height;
+      png_ptr->iwidth = png_ptr->width;
+   }
+   max_pixel_depth = png_ptr->pixel_depth;
+   /* WARNING: * png_read_transform_info (pngrtran.c) performs a simpliar set of
+    * calculations to calculate the final pixel depth, then
+    * png_do_read_transforms actually does the transforms.  This means that the
+    * code which effectively calculates this value is actually repeated in three
+    * separate places.  They must all match.  Innocent changes to the order of
+    * transformations can and will break libpng in a way that causes memory
+    * overwrites.
+    *
+    * TODO: fix this.
+    */
+#ifdef PNG_READ_PACK_SUPPORTED
+   if ((png_ptr->transformations & PNG_PACK) && png_ptr->bit_depth < 8)
+      max_pixel_depth = 8;
+#endif
+#ifdef PNG_READ_EXPAND_SUPPORTED
+   if (png_ptr->transformations & PNG_EXPAND)
+   {
+      if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+      {
+         if (png_ptr->num_trans)
+            max_pixel_depth = 32;
+         else
+            max_pixel_depth = 24;
+      }
+      else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
+      {
+         if (max_pixel_depth < 8)
+            max_pixel_depth = 8;
+         if (png_ptr->num_trans)
+            max_pixel_depth *= 2;
+      }
+      else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
+      {
+         if (png_ptr->num_trans)
+         {
+            max_pixel_depth *= 4;
+            max_pixel_depth /= 3;
+         }
+      }
+   }
+#endif
+#ifdef PNG_READ_EXPAND_16_SUPPORTED
+   if (png_ptr->transformations & PNG_EXPAND_16)
+   {
+#     ifdef PNG_READ_EXPAND_SUPPORTED
+         /* In fact it is an error if it isn't supported, but checking is
+          * the safe way.
+          */
+         if (png_ptr->transformations & PNG_EXPAND)
+         {
+            if (png_ptr->bit_depth < 16)
+               max_pixel_depth *= 2;
+         }
+         else
+#     endif
+         png_ptr->transformations &= ~PNG_EXPAND_16;
+   }
+#endif
+#ifdef PNG_READ_FILLER_SUPPORTED
+   if (png_ptr->transformations & (PNG_FILLER))
+   {
+      if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
+      {
+         if (max_pixel_depth <= 8)
+            max_pixel_depth = 16;
+         else
+            max_pixel_depth = 32;
+      }
+      else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB ||
+         png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+      {
+         if (max_pixel_depth <= 32)
+            max_pixel_depth = 32;
+         else
+            max_pixel_depth = 64;
+      }
+   }
+#endif
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+   if (png_ptr->transformations & PNG_GRAY_TO_RGB)
+   {
+      if (
+#ifdef PNG_READ_EXPAND_SUPPORTED
+          (png_ptr->num_trans && (png_ptr->transformations & PNG_EXPAND)) ||
+#endif
+#ifdef PNG_READ_FILLER_SUPPORTED
+          (png_ptr->transformations & (PNG_FILLER)) ||
+#endif
+          png_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+      {
+         if (max_pixel_depth <= 16)
+            max_pixel_depth = 32;
+         else
+            max_pixel_depth = 64;
+      }
+      else
+      {
+         if (max_pixel_depth <= 8)
+         {
+            if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+               max_pixel_depth = 32;
+            else
+               max_pixel_depth = 24;
+         }
+         else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+            max_pixel_depth = 64;
+         else
+            max_pixel_depth = 48;
+      }
+   }
+#endif
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) && \
+defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
+   if (png_ptr->transformations & PNG_USER_TRANSFORM)
+   {
+      int user_pixel_depth = png_ptr->user_transform_depth *
+         png_ptr->user_transform_channels;
+      if (user_pixel_depth > max_pixel_depth)
+         max_pixel_depth = user_pixel_depth;
+   }
+#endif
+   /* This value is stored in png_struct and double checked in the row read
+    * code.
+    */
+   png_ptr->maximum_pixel_depth = (png_byte)max_pixel_depth;
+   png_ptr->transformed_pixel_depth = 0; /* calculated on demand */
+   /* Align the width on the next larger 8 pixels.  Mainly used
+    * for interlacing
+    */
+   row_bytes = ((png_ptr->width + 7) & ~((png_uint_32)7));
+   /* Calculate the maximum bytes needed, adding a byte and a pixel
+    * for safety's sake
+    */
+   row_bytes = PNG_ROWBYTES(max_pixel_depth, row_bytes) +
+       1 + ((max_pixel_depth + 7) >> 3);
+#ifdef PNG_MAX_MALLOC_64K
+   if (row_bytes > (png_uint_32)65536L)
+      png_error(png_ptr, "This image requires a row greater than 64KB");
+#endif
+   if (row_bytes + 48 > png_ptr->old_big_row_buf_size)
+   {
+     png_free(png_ptr, png_ptr->big_row_buf);
+     png_free(png_ptr, png_ptr->big_prev_row);
+     if (png_ptr->interlaced)
+        png_ptr->big_row_buf = (png_bytep)png_calloc(png_ptr,
+            row_bytes + 48);
+     else
+        png_ptr->big_row_buf = (png_bytep)png_malloc(png_ptr, row_bytes + 48);
+     png_ptr->big_prev_row = (png_bytep)png_malloc(png_ptr, row_bytes + 48);
+#ifdef PNG_ALIGNED_MEMORY_SUPPORTED
+     /* Use 16-byte aligned memory for row_buf with at least 16 bytes
+      * of padding before and after row_buf; treat prev_row similarly.
+      * NOTE: the alignment is to the start of the pixels, one beyond the start
+      * of the buffer, because of the filter byte.  Prior to libpng 1.5.6 this
+      * was incorrect; the filter byte was aligned, which had the exact
+      * opposite effect of that intended.
+      */
+     {
+        png_bytep temp = png_ptr->big_row_buf + 32;
+        int extra = (int)((temp - (png_bytep)0) & 0x0f);
+        png_ptr->row_buf = temp - extra - 1/*filter byte*/;
+        temp = png_ptr->big_prev_row + 32;
+        extra = (int)((temp - (png_bytep)0) & 0x0f);
+        png_ptr->prev_row = temp - extra - 1/*filter byte*/;
+     }
+#else
+     /* Use 31 bytes of padding before and 17 bytes after row_buf. */
+     png_ptr->row_buf = png_ptr->big_row_buf + 31;
+     png_ptr->prev_row = png_ptr->big_prev_row + 31;
+#endif
+     png_ptr->old_big_row_buf_size = row_bytes + 48;
+   }
+#ifdef PNG_MAX_MALLOC_64K
+   if (png_ptr->rowbytes > 65535)
+      png_error(png_ptr, "This image requires a row greater than 64KB");
+#endif
+   if (png_ptr->rowbytes > (PNG_SIZE_MAX - 1))
+      png_error(png_ptr, "Row has too many bytes to allocate in memory");
+   png_memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
+   png_debug1(3, "width = %u,", png_ptr->width);
+   png_debug1(3, "height = %u,", png_ptr->height);
+   png_debug1(3, "iwidth = %u,", png_ptr->iwidth);
+   png_debug1(3, "num_rows = %u,", png_ptr->num_rows);
+   png_debug1(3, "rowbytes = %lu,", (unsigned long)png_ptr->rowbytes);
+   png_debug1(3, "irowbytes = %lu",
+       (unsigned long)PNG_ROWBYTES(png_ptr->pixel_depth, png_ptr->iwidth) + 1);
+   png_ptr->flags |= PNG_FLAG_ROW_INIT;
+}
+#endif /* PNG_READ_SUPPORTED */
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngset.c b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngset.c
new file mode 100644
index 0000000..e753ca8
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngset.c
@@ -0,0 +1,1284 @@
+/* pngset.c - storage of image information into info struct
+ *
+ * Last changed in libpng 1.5.7 [December 15, 2011]
+ * Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * The functions here are used during reads to store data from the file
+ * into the info struct, and during writes to store application data
+ * into the info struct for writing into the file.  This abstracts the
+ * info struct and allows us to change the structure in the future.
+ */
+#include "pngpriv.h"
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+#ifdef PNG_bKGD_SUPPORTED
+void PNGAPI
+png_set_bKGD(png_structp png_ptr, png_infop info_ptr,
+    png_const_color_16p background)
+{
+   png_debug1(1, "in %s storage function", "bKGD");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+   png_memcpy(&(info_ptr->background), background, png_sizeof(png_color_16));
+   info_ptr->valid |= PNG_INFO_bKGD;
+}
+#endif
+#ifdef PNG_cHRM_SUPPORTED
+void PNGFAPI
+png_set_cHRM_fixed(png_structp png_ptr, png_infop info_ptr,
+    png_fixed_point white_x, png_fixed_point white_y, png_fixed_point red_x,
+    png_fixed_point red_y, png_fixed_point green_x, png_fixed_point green_y,
+    png_fixed_point blue_x, png_fixed_point blue_y)
+{
+   png_debug1(1, "in %s storage function", "cHRM fixed");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+#  ifdef PNG_CHECK_cHRM_SUPPORTED
+   if (png_check_cHRM_fixed(png_ptr,
+       white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y))
+#  endif
+   {
+      info_ptr->x_white = white_x;
+      info_ptr->y_white = white_y;
+      info_ptr->x_red   = red_x;
+      info_ptr->y_red   = red_y;
+      info_ptr->x_green = green_x;
+      info_ptr->y_green = green_y;
+      info_ptr->x_blue  = blue_x;
+      info_ptr->y_blue  = blue_y;
+      info_ptr->valid |= PNG_INFO_cHRM;
+   }
+}
+void PNGFAPI
+png_set_cHRM_XYZ_fixed(png_structp png_ptr, png_infop info_ptr,
+    png_fixed_point int_red_X, png_fixed_point int_red_Y,
+    png_fixed_point int_red_Z, png_fixed_point int_green_X,
+    png_fixed_point int_green_Y, png_fixed_point int_green_Z,
+    png_fixed_point int_blue_X, png_fixed_point int_blue_Y,
+    png_fixed_point int_blue_Z)
+{
+   png_XYZ XYZ;
+   png_xy xy;
+   png_debug1(1, "in %s storage function", "cHRM XYZ fixed");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+   XYZ.redX = int_red_X;
+   XYZ.redY = int_red_Y;
+   XYZ.redZ = int_red_Z;
+   XYZ.greenX = int_green_X;
+   XYZ.greenY = int_green_Y;
+   XYZ.greenZ = int_green_Z;
+   XYZ.blueX = int_blue_X;
+   XYZ.blueY = int_blue_Y;
+   XYZ.blueZ = int_blue_Z;
+   if (png_xy_from_XYZ(&xy, XYZ))
+      png_error(png_ptr, "XYZ values out of representable range");
+   png_set_cHRM_fixed(png_ptr, info_ptr, xy.whitex, xy.whitey, xy.redx, xy.redy,
+      xy.greenx, xy.greeny, xy.bluex, xy.bluey);
+}
+#  ifdef PNG_FLOATING_POINT_SUPPORTED
+void PNGAPI
+png_set_cHRM(png_structp png_ptr, png_infop info_ptr,
+    double white_x, double white_y, double red_x, double red_y,
+    double green_x, double green_y, double blue_x, double blue_y)
+{
+   png_set_cHRM_fixed(png_ptr, info_ptr,
+      png_fixed(png_ptr, white_x, "cHRM White X"),
+      png_fixed(png_ptr, white_y, "cHRM White Y"),
+      png_fixed(png_ptr, red_x, "cHRM Red X"),
+      png_fixed(png_ptr, red_y, "cHRM Red Y"),
+      png_fixed(png_ptr, green_x, "cHRM Green X"),
+      png_fixed(png_ptr, green_y, "cHRM Green Y"),
+      png_fixed(png_ptr, blue_x, "cHRM Blue X"),
+      png_fixed(png_ptr, blue_y, "cHRM Blue Y"));
+}
+void PNGAPI
+png_set_cHRM_XYZ(png_structp png_ptr, png_infop info_ptr, double red_X,
+    double red_Y, double red_Z, double green_X, double green_Y, double green_Z,
+    double blue_X, double blue_Y, double blue_Z)
+{
+   png_set_cHRM_XYZ_fixed(png_ptr, info_ptr,
+      png_fixed(png_ptr, red_X, "cHRM Red X"),
+      png_fixed(png_ptr, red_Y, "cHRM Red Y"),
+      png_fixed(png_ptr, red_Z, "cHRM Red Z"),
+      png_fixed(png_ptr, green_X, "cHRM Red X"),
+      png_fixed(png_ptr, green_Y, "cHRM Red Y"),
+      png_fixed(png_ptr, green_Z, "cHRM Red Z"),
+      png_fixed(png_ptr, blue_X, "cHRM Red X"),
+      png_fixed(png_ptr, blue_Y, "cHRM Red Y"),
+      png_fixed(png_ptr, blue_Z, "cHRM Red Z"));
+}
+#  endif /* PNG_FLOATING_POINT_SUPPORTED */
+#endif /* PNG_cHRM_SUPPORTED */
+#ifdef PNG_gAMA_SUPPORTED
+void PNGFAPI
+png_set_gAMA_fixed(png_structp png_ptr, png_infop info_ptr, png_fixed_point
+    file_gamma)
+{
+   png_debug1(1, "in %s storage function", "gAMA");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+   /* Changed in libpng-1.5.4 to limit the values to ensure overflow can't
+    * occur.  Since the fixed point representation is assymetrical it is
+    * possible for 1/gamma to overflow the limit of 21474 and this means the
+    * gamma value must be at least 5/100000 and hence at most 20000.0.  For
+    * safety the limits here are a little narrower.  The values are 0.00016 to
+    * 6250.0, which are truly ridiculous gammma values (and will produce
+    * displays that are all black or all white.)
+    */
+   if (file_gamma < 16 || file_gamma > 625000000)
+      png_warning(png_ptr, "Out of range gamma value ignored");
+   else
+   {
+      info_ptr->gamma = file_gamma;
+      info_ptr->valid |= PNG_INFO_gAMA;
+   }
+}
+#  ifdef PNG_FLOATING_POINT_SUPPORTED
+void PNGAPI
+png_set_gAMA(png_structp png_ptr, png_infop info_ptr, double file_gamma)
+{
+   png_set_gAMA_fixed(png_ptr, info_ptr, png_fixed(png_ptr, file_gamma,
+       "png_set_gAMA"));
+}
+#  endif
+#endif
+#ifdef PNG_hIST_SUPPORTED
+void PNGAPI
+png_set_hIST(png_structp png_ptr, png_infop info_ptr, png_const_uint_16p hist)
+{
+   int i;
+   png_debug1(1, "in %s storage function", "hIST");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+   if (info_ptr->num_palette == 0 || info_ptr->num_palette
+       > PNG_MAX_PALETTE_LENGTH)
+   {
+      png_warning(png_ptr,
+          "Invalid palette size, hIST allocation skipped");
+      return;
+   }
+   png_free_data(png_ptr, info_ptr, PNG_FREE_HIST, 0);
+   /* Changed from info->num_palette to PNG_MAX_PALETTE_LENGTH in
+    * version 1.2.1
+    */
+   png_ptr->hist = (png_uint_16p)png_malloc_warn(png_ptr,
+       PNG_MAX_PALETTE_LENGTH * png_sizeof(png_uint_16));
+   if (png_ptr->hist == NULL)
+   {
+      png_warning(png_ptr, "Insufficient memory for hIST chunk data");
+      return;
+   }
+   for (i = 0; i < info_ptr->num_palette; i++)
+      png_ptr->hist[i] = hist[i];
+   info_ptr->hist = png_ptr->hist;
+   info_ptr->valid |= PNG_INFO_hIST;
+   info_ptr->free_me |= PNG_FREE_HIST;
+}
+#endif
+void PNGAPI
+png_set_IHDR(png_structp png_ptr, png_infop info_ptr,
+    png_uint_32 width, png_uint_32 height, int bit_depth,
+    int color_type, int interlace_type, int compression_type,
+    int filter_type)
+{
+   png_debug1(1, "in %s storage function", "IHDR");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+   info_ptr->width = width;
+   info_ptr->height = height;
+   info_ptr->bit_depth = (png_byte)bit_depth;
+   info_ptr->color_type = (png_byte)color_type;
+   info_ptr->compression_type = (png_byte)compression_type;
+   info_ptr->filter_type = (png_byte)filter_type;
+   info_ptr->interlace_type = (png_byte)interlace_type;
+   png_check_IHDR (png_ptr, info_ptr->width, info_ptr->height,
+       info_ptr->bit_depth, info_ptr->color_type, info_ptr->interlace_type,
+       info_ptr->compression_type, info_ptr->filter_type);
+   if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+      info_ptr->channels = 1;
+   else if (info_ptr->color_type & PNG_COLOR_MASK_COLOR)
+      info_ptr->channels = 3;
+   else
+      info_ptr->channels = 1;
+   if (info_ptr->color_type & PNG_COLOR_MASK_ALPHA)
+      info_ptr->channels++;
+   info_ptr->pixel_depth = (png_byte)(info_ptr->channels * info_ptr->bit_depth);
+   /* Check for potential overflow */
+   if (width >
+       (PNG_UINT_32_MAX >> 3)      /* 8-byte RRGGBBAA pixels */
+       - 48       /* bigrowbuf hack */
+       - 1        /* filter byte */
+       - 7*8      /* rounding of width to multiple of 8 pixels */
+       - 8)       /* extra max_pixel_depth pad */
+      info_ptr->rowbytes = 0;
+   else
+      info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, width);
+}
+#ifdef PNG_oFFs_SUPPORTED
+void PNGAPI
+png_set_oFFs(png_structp png_ptr, png_infop info_ptr,
+    png_int_32 offset_x, png_int_32 offset_y, int unit_type)
+{
+   png_debug1(1, "in %s storage function", "oFFs");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+   info_ptr->x_offset = offset_x;
+   info_ptr->y_offset = offset_y;
+   info_ptr->offset_unit_type = (png_byte)unit_type;
+   info_ptr->valid |= PNG_INFO_oFFs;
+}
+#endif
+#ifdef PNG_pCAL_SUPPORTED
+void PNGAPI
+png_set_pCAL(png_structp png_ptr, png_infop info_ptr,
+    png_const_charp purpose, png_int_32 X0, png_int_32 X1, int type,
+    int nparams, png_const_charp units, png_charpp params)
+{
+   png_size_t length;
+   int i;
+   png_debug1(1, "in %s storage function", "pCAL");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+   length = png_strlen(purpose) + 1;
+   png_debug1(3, "allocating purpose for info (%lu bytes)",
+       (unsigned long)length);
+   /* TODO: validate format of calibration name and unit name */
+   /* Check that the type matches the specification. */
+   if (type < 0 || type > 3)
+      png_error(png_ptr, "Invalid pCAL equation type");
+   /* Validate params[nparams] */
+   for (i=0; i<nparams; ++i)
+      if (!png_check_fp_string(params[i], png_strlen(params[i])))
+         png_error(png_ptr, "Invalid format for pCAL parameter");
+   info_ptr->pcal_purpose = (png_charp)png_malloc_warn(png_ptr, length);
+   if (info_ptr->pcal_purpose == NULL)
+   {
+      png_warning(png_ptr, "Insufficient memory for pCAL purpose");
+      return;
+   }
+   png_memcpy(info_ptr->pcal_purpose, purpose, length);
+   png_debug(3, "storing X0, X1, type, and nparams in info");
+   info_ptr->pcal_X0 = X0;
+   info_ptr->pcal_X1 = X1;
+   info_ptr->pcal_type = (png_byte)type;
+   info_ptr->pcal_nparams = (png_byte)nparams;
+   length = png_strlen(units) + 1;
+   png_debug1(3, "allocating units for info (%lu bytes)",
+     (unsigned long)length);
+   info_ptr->pcal_units = (png_charp)png_malloc_warn(png_ptr, length);
+   if (info_ptr->pcal_units == NULL)
+   {
+      png_warning(png_ptr, "Insufficient memory for pCAL units");
+      return;
+   }
+   png_memcpy(info_ptr->pcal_units, units, length);
+   info_ptr->pcal_params = (png_charpp)png_malloc_warn(png_ptr,
+       (png_size_t)((nparams + 1) * png_sizeof(png_charp)));
+   if (info_ptr->pcal_params == NULL)
+   {
+      png_warning(png_ptr, "Insufficient memory for pCAL params");
+      return;
+   }
+   png_memset(info_ptr->pcal_params, 0, (nparams + 1) * png_sizeof(png_charp));
+   for (i = 0; i < nparams; i++)
+   {
+      length = png_strlen(params[i]) + 1;
+      png_debug2(3, "allocating parameter %d for info (%lu bytes)", i,
+          (unsigned long)length);
+      info_ptr->pcal_params[i] = (png_charp)png_malloc_warn(png_ptr, length);
+      if (info_ptr->pcal_params[i] == NULL)
+      {
+         png_warning(png_ptr, "Insufficient memory for pCAL parameter");
+         return;
+      }
+      png_memcpy(info_ptr->pcal_params[i], params[i], length);
+   }
+   info_ptr->valid |= PNG_INFO_pCAL;
+   info_ptr->free_me |= PNG_FREE_PCAL;
+}
+#endif
+#ifdef PNG_sCAL_SUPPORTED
+void PNGAPI
+png_set_sCAL_s(png_structp png_ptr, png_infop info_ptr,
+    int unit, png_const_charp swidth, png_const_charp sheight)
+{
+   png_size_t lengthw = 0, lengthh = 0;
+   png_debug1(1, "in %s storage function", "sCAL");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+   /* Double check the unit (should never get here with an invalid
+    * unit unless this is an API call.)
+    */
+   if (unit != 1 && unit != 2)
+      png_error(png_ptr, "Invalid sCAL unit");
+   if (swidth == NULL || (lengthw = png_strlen(swidth)) == 0 ||
+       swidth[0] == 45 /* '-' */ || !png_check_fp_string(swidth, lengthw))
+      png_error(png_ptr, "Invalid sCAL width");
+   if (sheight == NULL || (lengthh = png_strlen(sheight)) == 0 ||
+       sheight[0] == 45 /* '-' */ || !png_check_fp_string(sheight, lengthh))
+      png_error(png_ptr, "Invalid sCAL height");
+   info_ptr->scal_unit = (png_byte)unit;
+   ++lengthw;
+   png_debug1(3, "allocating unit for info (%u bytes)", (unsigned int)lengthw);
+   info_ptr->scal_s_width = (png_charp)png_malloc_warn(png_ptr, lengthw);
+   if (info_ptr->scal_s_width == NULL)
+   {
+      png_warning(png_ptr, "Memory allocation failed while processing sCAL");
+      return;
+   }
+   png_memcpy(info_ptr->scal_s_width, swidth, lengthw);
+   ++lengthh;
+   png_debug1(3, "allocating unit for info (%u bytes)", (unsigned int)lengthh);
+   info_ptr->scal_s_height = (png_charp)png_malloc_warn(png_ptr, lengthh);
+   if (info_ptr->scal_s_height == NULL)
+   {
+      png_free (png_ptr, info_ptr->scal_s_width);
+      info_ptr->scal_s_width = NULL;
+      png_warning(png_ptr, "Memory allocation failed while processing sCAL");
+      return;
+   }
+   png_memcpy(info_ptr->scal_s_height, sheight, lengthh);
+   info_ptr->valid |= PNG_INFO_sCAL;
+   info_ptr->free_me |= PNG_FREE_SCAL;
+}
+#  ifdef PNG_FLOATING_POINT_SUPPORTED
+void PNGAPI
+png_set_sCAL(png_structp png_ptr, png_infop info_ptr, int unit, double width,
+    double height)
+{
+   png_debug1(1, "in %s storage function", "sCAL");
+   /* Check the arguments. */
+   if (width <= 0)
+      png_warning(png_ptr, "Invalid sCAL width ignored");
+   else if (height <= 0)
+      png_warning(png_ptr, "Invalid sCAL height ignored");
+   else
+   {
+      /* Convert 'width' and 'height' to ASCII. */
+      char swidth[PNG_sCAL_MAX_DIGITS+1];
+      char sheight[PNG_sCAL_MAX_DIGITS+1];
+      png_ascii_from_fp(png_ptr, swidth, sizeof swidth, width,
+         PNG_sCAL_PRECISION);
+      png_ascii_from_fp(png_ptr, sheight, sizeof sheight, height,
+         PNG_sCAL_PRECISION);
+      png_set_sCAL_s(png_ptr, info_ptr, unit, swidth, sheight);
+   }
+}
+#  endif
+#  ifdef PNG_FIXED_POINT_SUPPORTED
+void PNGAPI
+png_set_sCAL_fixed(png_structp png_ptr, png_infop info_ptr, int unit,
+    png_fixed_point width, png_fixed_point height)
+{
+   png_debug1(1, "in %s storage function", "sCAL");
+   /* Check the arguments. */
+   if (width <= 0)
+      png_warning(png_ptr, "Invalid sCAL width ignored");
+   else if (height <= 0)
+      png_warning(png_ptr, "Invalid sCAL height ignored");
+   else
+   {
+      /* Convert 'width' and 'height' to ASCII. */
+      char swidth[PNG_sCAL_MAX_DIGITS+1];
+      char sheight[PNG_sCAL_MAX_DIGITS+1];
+      png_ascii_from_fixed(png_ptr, swidth, sizeof swidth, width);
+      png_ascii_from_fixed(png_ptr, sheight, sizeof sheight, height);
+      png_set_sCAL_s(png_ptr, info_ptr, unit, swidth, sheight);
+   }
+}
+#  endif
+#endif
+#ifdef PNG_pHYs_SUPPORTED
+void PNGAPI
+png_set_pHYs(png_structp png_ptr, png_infop info_ptr,
+    png_uint_32 res_x, png_uint_32 res_y, int unit_type)
+{
+   png_debug1(1, "in %s storage function", "pHYs");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+   info_ptr->x_pixels_per_unit = res_x;
+   info_ptr->y_pixels_per_unit = res_y;
+   info_ptr->phys_unit_type = (png_byte)unit_type;
+   info_ptr->valid |= PNG_INFO_pHYs;
+}
+#endif
+void PNGAPI
+png_set_PLTE(png_structp png_ptr, png_infop info_ptr,
+    png_const_colorp palette, int num_palette)
+{
+   png_debug1(1, "in %s storage function", "PLTE");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+   if (num_palette < 0 || num_palette > PNG_MAX_PALETTE_LENGTH)
+   {
+      if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+         png_error(png_ptr, "Invalid palette length");
+      else
+      {
+         png_warning(png_ptr, "Invalid palette length");
+         return;
+      }
+   }
+   /* It may not actually be necessary to set png_ptr->palette here;
+    * we do it for backward compatibility with the way the png_handle_tRNS
+    * function used to do the allocation.
+    */
+   png_free_data(png_ptr, info_ptr, PNG_FREE_PLTE, 0);
+   /* Changed in libpng-1.2.1 to allocate PNG_MAX_PALETTE_LENGTH instead
+    * of num_palette entries, in case of an invalid PNG file that has
+    * too-large sample values.
+    */
+   png_ptr->palette = (png_colorp)png_calloc(png_ptr,
+       PNG_MAX_PALETTE_LENGTH * png_sizeof(png_color));
+   png_memcpy(png_ptr->palette, palette, num_palette * png_sizeof(png_color));
+   info_ptr->palette = png_ptr->palette;
+   info_ptr->num_palette = png_ptr->num_palette = (png_uint_16)num_palette;
+   info_ptr->free_me |= PNG_FREE_PLTE;
+   info_ptr->valid |= PNG_INFO_PLTE;
+}
+#ifdef PNG_sBIT_SUPPORTED
+void PNGAPI
+png_set_sBIT(png_structp png_ptr, png_infop info_ptr,
+    png_const_color_8p sig_bit)
+{
+   png_debug1(1, "in %s storage function", "sBIT");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+   png_memcpy(&(info_ptr->sig_bit), sig_bit, png_sizeof(png_color_8));
+   info_ptr->valid |= PNG_INFO_sBIT;
+}
+#endif
+#ifdef PNG_sRGB_SUPPORTED
+void PNGAPI
+png_set_sRGB(png_structp png_ptr, png_infop info_ptr, int srgb_intent)
+{
+   png_debug1(1, "in %s storage function", "sRGB");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+   info_ptr->srgb_intent = (png_byte)srgb_intent;
+   info_ptr->valid |= PNG_INFO_sRGB;
+}
+void PNGAPI
+png_set_sRGB_gAMA_and_cHRM(png_structp png_ptr, png_infop info_ptr,
+    int srgb_intent)
+{
+   png_debug1(1, "in %s storage function", "sRGB_gAMA_and_cHRM");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+   png_set_sRGB(png_ptr, info_ptr, srgb_intent);
+#  ifdef PNG_gAMA_SUPPORTED
+   png_set_gAMA_fixed(png_ptr, info_ptr, PNG_GAMMA_sRGB_INVERSE);
+#  endif
+#  ifdef PNG_cHRM_SUPPORTED
+   png_set_cHRM_fixed(png_ptr, info_ptr,
+      /* color      x       y */
+      /* white */ 31270, 32900,
+      /* red   */ 64000, 33000,
+      /* green */ 30000, 60000,
+      /* blue  */ 15000,  6000
+   );
+#  endif /* cHRM */
+}
+#endif /* sRGB */
+#ifdef PNG_iCCP_SUPPORTED
+void PNGAPI
+png_set_iCCP(png_structp png_ptr, png_infop info_ptr,
+    png_const_charp name, int compression_type,
+    png_const_bytep profile, png_uint_32 proflen)
+{
+   png_charp new_iccp_name;
+   png_bytep new_iccp_profile;
+   png_size_t length;
+   png_debug1(1, "in %s storage function", "iCCP");
+   if (png_ptr == NULL || info_ptr == NULL || name == NULL || profile == NULL)
+      return;
+   length = png_strlen(name)+1;
+   new_iccp_name = (png_charp)png_malloc_warn(png_ptr, length);
+   if (new_iccp_name == NULL)
+   {
+        png_warning(png_ptr, "Insufficient memory to process iCCP chunk");
+      return;
+   }
+   png_memcpy(new_iccp_name, name, length);
+   new_iccp_profile = (png_bytep)png_malloc_warn(png_ptr, proflen);
+   if (new_iccp_profile == NULL)
+   {
+      png_free (png_ptr, new_iccp_name);
+      png_warning(png_ptr,
+          "Insufficient memory to process iCCP profile");
+      return;
+   }
+   png_memcpy(new_iccp_profile, profile, (png_size_t)proflen);
+   png_free_data(png_ptr, info_ptr, PNG_FREE_ICCP, 0);
+   info_ptr->iccp_proflen = proflen;
+   info_ptr->iccp_name = new_iccp_name;
+   info_ptr->iccp_profile = new_iccp_profile;
+   /* Compression is always zero but is here so the API and info structure
+    * does not have to change if we introduce multiple compression types
+    */
+   info_ptr->iccp_compression = (png_byte)compression_type;
+   info_ptr->free_me |= PNG_FREE_ICCP;
+   info_ptr->valid |= PNG_INFO_iCCP;
+}
+#endif
+#ifdef PNG_TEXT_SUPPORTED
+void PNGAPI
+png_set_text(png_structp png_ptr, png_infop info_ptr, png_const_textp text_ptr,
+    int num_text)
+{
+   int ret;
+   ret = png_set_text_2(png_ptr, info_ptr, text_ptr, num_text);
+   if (ret)
+      png_error(png_ptr, "Insufficient memory to store text");
+}
+int /* PRIVATE */
+png_set_text_2(png_structp png_ptr, png_infop info_ptr,
+    png_const_textp text_ptr, int num_text)
+{
+   int i;
+   png_debug1(1, "in %lx storage function", png_ptr == NULL ? "unexpected" :
+      (unsigned long)png_ptr->chunk_name);
+   if (png_ptr == NULL || info_ptr == NULL || num_text == 0)
+      return(0);
+   /* Make sure we have enough space in the "text" array in info_struct
+    * to hold all of the incoming text_ptr objects.
+    */
+   if (info_ptr->num_text + num_text > info_ptr->max_text)
+   {
+      if (info_ptr->text != NULL)
+      {
+         png_textp old_text;
+         int old_max;
+         old_max = info_ptr->max_text;
+         info_ptr->max_text = info_ptr->num_text + num_text + 8;
+         old_text = info_ptr->text;
+         info_ptr->text = (png_textp)png_malloc_warn(png_ptr,
+            (png_size_t)(info_ptr->max_text * png_sizeof(png_text)));
+         if (info_ptr->text == NULL)
+         {
+            png_free(png_ptr, old_text);
+            return(1);
+         }
+         png_memcpy(info_ptr->text, old_text, (png_size_t)(old_max *
+             png_sizeof(png_text)));
+         png_free(png_ptr, old_text);
+      }
+      else
+      {
+         info_ptr->max_text = num_text + 8;
+         info_ptr->num_text = 0;
+         info_ptr->text = (png_textp)png_malloc_warn(png_ptr,
+             (png_size_t)(info_ptr->max_text * png_sizeof(png_text)));
+         if (info_ptr->text == NULL)
+            return(1);
+         info_ptr->free_me |= PNG_FREE_TEXT;
+      }
+      png_debug1(3, "allocated %d entries for info_ptr->text",
+          info_ptr->max_text);
+   }
+   for (i = 0; i < num_text; i++)
+   {
+      png_size_t text_length, key_len;
+      png_size_t lang_len, lang_key_len;
+      png_textp textp = &(info_ptr->text[info_ptr->num_text]);
+      if (text_ptr[i].key == NULL)
+          continue;
+      if (text_ptr[i].compression < PNG_TEXT_COMPRESSION_NONE ||
+          text_ptr[i].compression >= PNG_TEXT_COMPRESSION_LAST)
+      {
+         png_warning(png_ptr, "text compression mode is out of range");
+         continue;
+      }
+      key_len = png_strlen(text_ptr[i].key);
+      if (text_ptr[i].compression <= 0)
+      {
+         lang_len = 0;
+         lang_key_len = 0;
+      }
+      else
+#  ifdef PNG_iTXt_SUPPORTED
+      {
+         /* Set iTXt data */
+         if (text_ptr[i].lang != NULL)
+            lang_len = png_strlen(text_ptr[i].lang);
+         else
+            lang_len = 0;
+         if (text_ptr[i].lang_key != NULL)
+            lang_key_len = png_strlen(text_ptr[i].lang_key);
+         else
+            lang_key_len = 0;
+      }
+#  else /* PNG_iTXt_SUPPORTED */
+      {
+         png_warning(png_ptr, "iTXt chunk not supported");
+         continue;
+      }
+#  endif
+      if (text_ptr[i].text == NULL || text_ptr[i].text[0] == '\0')
+      {
+         text_length = 0;
+#  ifdef PNG_iTXt_SUPPORTED
+         if (text_ptr[i].compression > 0)
+            textp->compression = PNG_ITXT_COMPRESSION_NONE;
+         else
+#  endif
+            textp->compression = PNG_TEXT_COMPRESSION_NONE;
+      }
+      else
+      {
+         text_length = png_strlen(text_ptr[i].text);
+         textp->compression = text_ptr[i].compression;
+      }
+      textp->key = (png_charp)png_malloc_warn(png_ptr,
+          (png_size_t)
+          (key_len + text_length + lang_len + lang_key_len + 4));
+      if (textp->key == NULL)
+         return(1);
+      png_debug2(2, "Allocated %lu bytes at %p in png_set_text",
+          (unsigned long)(png_uint_32)
+          (key_len + lang_len + lang_key_len + text_length + 4),
+          textp->key);
+      png_memcpy(textp->key, text_ptr[i].key,(png_size_t)(key_len));
+      *(textp->key + key_len) = '\0';
+      if (text_ptr[i].compression > 0)
+      {
+         textp->lang = textp->key + key_len + 1;
+         png_memcpy(textp->lang, text_ptr[i].lang, lang_len);
+         *(textp->lang + lang_len) = '\0';
+         textp->lang_key = textp->lang + lang_len + 1;
+         png_memcpy(textp->lang_key, text_ptr[i].lang_key, lang_key_len);
+         *(textp->lang_key + lang_key_len) = '\0';
+         textp->text = textp->lang_key + lang_key_len + 1;
+      }
+      else
+      {
+         textp->lang=NULL;
+         textp->lang_key=NULL;
+         textp->text = textp->key + key_len + 1;
+      }
+      if (text_length)
+         png_memcpy(textp->text, text_ptr[i].text,
+             (png_size_t)(text_length));
+      *(textp->text + text_length) = '\0';
+#  ifdef PNG_iTXt_SUPPORTED
+      if (textp->compression > 0)
+      {
+         textp->text_length = 0;
+         textp->itxt_length = text_length;
+      }
+      else
+#  endif
+      {
+         textp->text_length = text_length;
+         textp->itxt_length = 0;
+      }
+      info_ptr->num_text++;
+      png_debug1(3, "transferred text chunk %d", info_ptr->num_text);
+   }
+   return(0);
+}
+#endif
+#ifdef PNG_tIME_SUPPORTED
+void PNGAPI
+png_set_tIME(png_structp png_ptr, png_infop info_ptr, png_const_timep mod_time)
+{
+   png_debug1(1, "in %s storage function", "tIME");
+   if (png_ptr == NULL || info_ptr == NULL ||
+       (png_ptr->mode & PNG_WROTE_tIME))
+      return;
+   if (mod_time->month == 0   || mod_time->month > 12  ||
+       mod_time->day   == 0   || mod_time->day   > 31  ||
+       mod_time->hour  > 23   || mod_time->minute > 59 ||
+       mod_time->second > 60)
+   {
+      png_warning(png_ptr, "Ignoring invalid time value");
+      return;
+   }
+   png_memcpy(&(info_ptr->mod_time), mod_time, png_sizeof(png_time));
+   info_ptr->valid |= PNG_INFO_tIME;
+}
+#endif
+#ifdef PNG_tRNS_SUPPORTED
+void PNGAPI
+png_set_tRNS(png_structp png_ptr, png_infop info_ptr,
+    png_const_bytep trans_alpha, int num_trans, png_const_color_16p trans_color)
+{
+   png_debug1(1, "in %s storage function", "tRNS");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+   if (trans_alpha != NULL)
+   {
+       /* It may not actually be necessary to set png_ptr->trans_alpha here;
+        * we do it for backward compatibility with the way the png_handle_tRNS
+        * function used to do the allocation.
+        */
+       png_free_data(png_ptr, info_ptr, PNG_FREE_TRNS, 0);
+       /* Changed from num_trans to PNG_MAX_PALETTE_LENGTH in version 1.2.1 */
+       png_ptr->trans_alpha = info_ptr->trans_alpha =
+           (png_bytep)png_malloc(png_ptr, (png_size_t)PNG_MAX_PALETTE_LENGTH);
+       if (num_trans > 0 && num_trans <= PNG_MAX_PALETTE_LENGTH)
+          png_memcpy(info_ptr->trans_alpha, trans_alpha, (png_size_t)num_trans);
+   }
+   if (trans_color != NULL)
+   {
+      int sample_max = (1 << info_ptr->bit_depth);
+      if ((info_ptr->color_type == PNG_COLOR_TYPE_GRAY &&
+          (int)trans_color->gray > sample_max) ||
+          (info_ptr->color_type == PNG_COLOR_TYPE_RGB &&
+          ((int)trans_color->red > sample_max ||
+          (int)trans_color->green > sample_max ||
+          (int)trans_color->blue > sample_max)))
+         png_warning(png_ptr,
+            "tRNS chunk has out-of-range samples for bit_depth");
+      png_memcpy(&(info_ptr->trans_color), trans_color,
+         png_sizeof(png_color_16));
+      if (num_trans == 0)
+         num_trans = 1;
+   }
+   info_ptr->num_trans = (png_uint_16)num_trans;
+   if (num_trans != 0)
+   {
+      info_ptr->valid |= PNG_INFO_tRNS;
+      info_ptr->free_me |= PNG_FREE_TRNS;
+   }
+}
+#endif
+#ifdef PNG_sPLT_SUPPORTED
+void PNGAPI
+png_set_sPLT(png_structp png_ptr,
+    png_infop info_ptr, png_const_sPLT_tp entries, int nentries)
+/*
+ *  entries        - array of png_sPLT_t structures
+ *                   to be added to the list of palettes
+ *                   in the info structure.
+ *
+ *  nentries       - number of palette structures to be
+ *                   added.
+ */
+{
+   png_sPLT_tp np;
+   int i;
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+   np = (png_sPLT_tp)png_malloc_warn(png_ptr,
+       (info_ptr->splt_palettes_num + nentries) *
+       (png_size_t)png_sizeof(png_sPLT_t));
+   if (np == NULL)
+   {
+      png_warning(png_ptr, "No memory for sPLT palettes");
+      return;
+   }
+   png_memcpy(np, info_ptr->splt_palettes,
+       info_ptr->splt_palettes_num * png_sizeof(png_sPLT_t));
+   png_free(png_ptr, info_ptr->splt_palettes);
+   info_ptr->splt_palettes=NULL;
+   for (i = 0; i < nentries; i++)
+   {
+      png_sPLT_tp to = np + info_ptr->splt_palettes_num + i;
+      png_const_sPLT_tp from = entries + i;
+      png_size_t length;
+      length = png_strlen(from->name) + 1;
+      to->name = (png_charp)png_malloc_warn(png_ptr, length);
+      if (to->name == NULL)
+      {
+         png_warning(png_ptr,
+             "Out of memory while processing sPLT chunk");
+         continue;
+      }
+      png_memcpy(to->name, from->name, length);
+      to->entries = (png_sPLT_entryp)png_malloc_warn(png_ptr,
+          from->nentries * png_sizeof(png_sPLT_entry));
+      if (to->entries == NULL)
+      {
+         png_warning(png_ptr,
+             "Out of memory while processing sPLT chunk");
+         png_free(png_ptr, to->name);
+         to->name = NULL;
+         continue;
+      }
+      png_memcpy(to->entries, from->entries,
+          from->nentries * png_sizeof(png_sPLT_entry));
+      to->nentries = from->nentries;
+      to->depth = from->depth;
+   }
+   info_ptr->splt_palettes = np;
+   info_ptr->splt_palettes_num += nentries;
+   info_ptr->valid |= PNG_INFO_sPLT;
+   info_ptr->free_me |= PNG_FREE_SPLT;
+}
+#endif /* PNG_sPLT_SUPPORTED */
+#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
+void PNGAPI
+png_set_unknown_chunks(png_structp png_ptr,
+   png_infop info_ptr, png_const_unknown_chunkp unknowns, int num_unknowns)
+{
+   png_unknown_chunkp np;
+   int i;
+   if (png_ptr == NULL || info_ptr == NULL || num_unknowns == 0)
+      return;
+   np = (png_unknown_chunkp)png_malloc_warn(png_ptr,
+       (png_size_t)(info_ptr->unknown_chunks_num + num_unknowns) *
+       png_sizeof(png_unknown_chunk));
+   if (np == NULL)
+   {
+      png_warning(png_ptr,
+          "Out of memory while processing unknown chunk");
+      return;
+   }
+   png_memcpy(np, info_ptr->unknown_chunks,
+       (png_size_t)info_ptr->unknown_chunks_num *
+       png_sizeof(png_unknown_chunk));
+   png_free(png_ptr, info_ptr->unknown_chunks);
+   info_ptr->unknown_chunks = NULL;
+   for (i = 0; i < num_unknowns; i++)
+   {
+      png_unknown_chunkp to = np + info_ptr->unknown_chunks_num + i;
+      png_const_unknown_chunkp from = unknowns + i;
+      png_memcpy(to->name, from->name, png_sizeof(from->name));
+      to->name[png_sizeof(to->name)-1] = '\0';
+      to->size = from->size;
+      /* Note our location in the read or write sequence */
+      to->location = (png_byte)(png_ptr->mode & 0xff);
+      if (from->size == 0)
+         to->data=NULL;
+      else
+      {
+         to->data = (png_bytep)png_malloc_warn(png_ptr,
+             (png_size_t)from->size);
+         if (to->data == NULL)
+         {
+            png_warning(png_ptr,
+                "Out of memory while processing unknown chunk");
+            to->size = 0;
+         }
+         else
+            png_memcpy(to->data, from->data, from->size);
+      }
+   }
+   info_ptr->unknown_chunks = np;
+   info_ptr->unknown_chunks_num += num_unknowns;
+   info_ptr->free_me |= PNG_FREE_UNKN;
+}
+void PNGAPI
+png_set_unknown_chunk_location(png_structp png_ptr, png_infop info_ptr,
+    int chunk, int location)
+{
+   if (png_ptr != NULL && info_ptr != NULL && chunk >= 0 && chunk <
+       info_ptr->unknown_chunks_num)
+      info_ptr->unknown_chunks[chunk].location = (png_byte)location;
+}
+#endif
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+png_uint_32 PNGAPI
+png_permit_mng_features (png_structp png_ptr, png_uint_32 mng_features)
+{
+   png_debug(1, "in png_permit_mng_features");
+   if (png_ptr == NULL)
+      return (png_uint_32)0;
+   png_ptr->mng_features_permitted =
+       (png_byte)(mng_features & PNG_ALL_MNG_FEATURES);
+   return (png_uint_32)png_ptr->mng_features_permitted;
+}
+#endif
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+void PNGAPI
+png_set_keep_unknown_chunks(png_structp png_ptr, int keep, png_const_bytep
+    chunk_list, int num_chunks)
+{
+   png_bytep new_list, p;
+   int i, old_num_chunks;
+   if (png_ptr == NULL)
+      return;
+   if (num_chunks == 0)
+   {
+      if (keep == PNG_HANDLE_CHUNK_ALWAYS || keep == PNG_HANDLE_CHUNK_IF_SAFE)
+         png_ptr->flags |= PNG_FLAG_KEEP_UNKNOWN_CHUNKS;
+      else
+         png_ptr->flags &= ~PNG_FLAG_KEEP_UNKNOWN_CHUNKS;
+      if (keep == PNG_HANDLE_CHUNK_ALWAYS)
+         png_ptr->flags |= PNG_FLAG_KEEP_UNSAFE_CHUNKS;
+      else
+         png_ptr->flags &= ~PNG_FLAG_KEEP_UNSAFE_CHUNKS;
+      return;
+   }
+   if (chunk_list == NULL)
+      return;
+   old_num_chunks = png_ptr->num_chunk_list;
+   new_list=(png_bytep)png_malloc(png_ptr,
+       (png_size_t)(5*(num_chunks + old_num_chunks)));
+   if (png_ptr->chunk_list != NULL)
+   {
+      png_memcpy(new_list, png_ptr->chunk_list,
+          (png_size_t)(5*old_num_chunks));
+      png_free(png_ptr, png_ptr->chunk_list);
+      png_ptr->chunk_list=NULL;
+   }
+   png_memcpy(new_list + 5*old_num_chunks, chunk_list,
+       (png_size_t)(5*num_chunks));
+   for (p = new_list + 5*old_num_chunks + 4, i = 0; i<num_chunks; i++, p += 5)
+      *p=(png_byte)keep;
+   png_ptr->num_chunk_list = old_num_chunks + num_chunks;
+   png_ptr->chunk_list = new_list;
+   png_ptr->free_me |= PNG_FREE_LIST;
+}
+#endif
+#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
+void PNGAPI
+png_set_read_user_chunk_fn(png_structp png_ptr, png_voidp user_chunk_ptr,
+    png_user_chunk_ptr read_user_chunk_fn)
+{
+   png_debug(1, "in png_set_read_user_chunk_fn");
+   if (png_ptr == NULL)
+      return;
+   png_ptr->read_user_chunk_fn = read_user_chunk_fn;
+   png_ptr->user_chunk_ptr = user_chunk_ptr;
+}
+#endif
+#ifdef PNG_INFO_IMAGE_SUPPORTED
+void PNGAPI
+png_set_rows(png_structp png_ptr, png_infop info_ptr, png_bytepp row_pointers)
+{
+   png_debug1(1, "in %s storage function", "rows");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+   if (info_ptr->row_pointers && (info_ptr->row_pointers != row_pointers))
+      png_free_data(png_ptr, info_ptr, PNG_FREE_ROWS, 0);
+   info_ptr->row_pointers = row_pointers;
+   if (row_pointers)
+      info_ptr->valid |= PNG_INFO_IDAT;
+}
+#endif
+void PNGAPI
+png_set_compression_buffer_size(png_structp png_ptr, png_size_t size)
+{
+    if (png_ptr == NULL)
+       return;
+    png_free(png_ptr, png_ptr->zbuf);
+    if (size > ZLIB_IO_MAX)
+    {
+       png_warning(png_ptr, "Attempt to set buffer size beyond max ignored");
+       png_ptr->zbuf_size = ZLIB_IO_MAX;
+       size = ZLIB_IO_MAX; /* must fit */
+    }
+    else
+       png_ptr->zbuf_size = (uInt)size;
+    png_ptr->zbuf = (png_bytep)png_malloc(png_ptr, size);
+    /* The following ensures a relatively safe failure if this gets called while
+     * the buffer is actually in use.
+     */
+    png_ptr->zstream.next_out = png_ptr->zbuf;
+    png_ptr->zstream.avail_out = 0;
+    png_ptr->zstream.avail_in = 0;
+}
+void PNGAPI
+png_set_invalid(png_structp png_ptr, png_infop info_ptr, int mask)
+{
+   if (png_ptr && info_ptr)
+      info_ptr->valid &= ~mask;
+}
+#ifdef PNG_SET_USER_LIMITS_SUPPORTED
+/* This function was added to libpng 1.2.6 */
+void PNGAPI
+png_set_user_limits (png_structp png_ptr, png_uint_32 user_width_max,
+    png_uint_32 user_height_max)
+{
+   /* Images with dimensions larger than these limits will be
+    * rejected by png_set_IHDR().  To accept any PNG datastream
+    * regardless of dimensions, set both limits to 0x7ffffffL.
+    */
+   if (png_ptr == NULL)
+      return;
+   png_ptr->user_width_max = user_width_max;
+   png_ptr->user_height_max = user_height_max;
+}
+/* This function was added to libpng 1.4.0 */
+void PNGAPI
+png_set_chunk_cache_max (png_structp png_ptr,
+   png_uint_32 user_chunk_cache_max)
+{
+    if (png_ptr)
+       png_ptr->user_chunk_cache_max = user_chunk_cache_max;
+}
+/* This function was added to libpng 1.4.1 */
+void PNGAPI
+png_set_chunk_malloc_max (png_structp png_ptr,
+    png_alloc_size_t user_chunk_malloc_max)
+{
+   if (png_ptr)
+      png_ptr->user_chunk_malloc_max = user_chunk_malloc_max;
+}
+#endif /* ?PNG_SET_USER_LIMITS_SUPPORTED */
+#ifdef PNG_BENIGN_ERRORS_SUPPORTED
+void PNGAPI
+png_set_benign_errors(png_structp png_ptr, int allowed)
+{
+   png_debug(1, "in png_set_benign_errors");
+   if (allowed)
+      png_ptr->flags |= PNG_FLAG_BENIGN_ERRORS_WARN;
+   else
+      png_ptr->flags &= ~PNG_FLAG_BENIGN_ERRORS_WARN;
+}
+#endif /* PNG_BENIGN_ERRORS_SUPPORTED */
+#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngstruct.h b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngstruct.h
new file mode 100644
index 0000000..1824c49
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngstruct.h
@@ -0,0 +1,358 @@
+/* pngstruct.h - header file for PNG reference library
+ *
+ * Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * Last changed in libpng 1.5.9 [February 18, 2012]
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+/* The structure that holds the information to read and write PNG files.
+ * The only people who need to care about what is inside of this are the
+ * people who will be modifying the library for their own special needs.
+ * It should NOT be accessed directly by an application.
+ */
+#ifndef PNGSTRUCT_H
+#define PNGSTRUCT_H
+/* zlib.h defines the structure z_stream, an instance of which is included
+ * in this structure and is required for decompressing the LZ compressed
+ * data in PNG files.
+ */
+#include "zlib.h"
+struct png_struct_def
+{
+#ifdef PNG_SETJMP_SUPPORTED
+   jmp_buf longjmp_buffer;    /* used in png_error */
+   png_longjmp_ptr longjmp_fn;/* setjmp non-local goto function. */
+#endif
+   png_error_ptr error_fn;    /* function for printing errors and aborting */
+#ifdef PNG_WARNINGS_SUPPORTED
+   png_error_ptr warning_fn;  /* function for printing warnings */
+#endif
+   png_voidp error_ptr;       /* user supplied struct for error functions */
+   png_rw_ptr write_data_fn;  /* function for writing output data */
+   png_rw_ptr read_data_fn;   /* function for reading input data */
+   png_voidp io_ptr;          /* ptr to application struct for I/O functions */
+#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
+   png_user_transform_ptr read_user_transform_fn; /* user read transform */
+#endif
+#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
+   png_user_transform_ptr write_user_transform_fn; /* user write transform */
+#endif
+/* These were added in libpng-1.0.2 */
+#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
+    defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
+   png_voidp user_transform_ptr; /* user supplied struct for user transform */
+   png_byte user_transform_depth;    /* bit depth of user transformed pixels */
+   png_byte user_transform_channels; /* channels in user transformed pixels */
+#endif
+#endif
+   png_uint_32 mode;          /* tells us where we are in the PNG file */
+   png_uint_32 flags;         /* flags indicating various things to libpng */
+   png_uint_32 transformations; /* which transformations to perform */
+   z_stream zstream;          /* pointer to decompression structure (below) */
+   png_bytep zbuf;            /* buffer for zlib */
+   uInt zbuf_size;            /* size of zbuf (typically 65536) */
+#ifdef PNG_WRITE_SUPPORTED
+/* Added in 1.5.4: state to keep track of whether the zstream has been
+ * initialized and if so whether it is for IDAT or some other chunk.
+ */
+#define PNG_ZLIB_UNINITIALIZED 0
+#define PNG_ZLIB_FOR_IDAT      1
+#define PNG_ZLIB_FOR_TEXT      2 /* anything other than IDAT */
+#define PNG_ZLIB_USE_MASK      3 /* bottom two bits */
+#define PNG_ZLIB_IN_USE        4 /* a flag value */
+   png_uint_32 zlib_state;       /* State of zlib initialization */
+/* End of material added at libpng 1.5.4 */
+   int zlib_level;            /* holds zlib compression level */
+   int zlib_method;           /* holds zlib compression method */
+   int zlib_window_bits;      /* holds zlib compression window bits */
+   int zlib_mem_level;        /* holds zlib compression memory level */
+   int zlib_strategy;         /* holds zlib compression strategy */
+#endif
+/* Added at libpng 1.5.4 */
+#if defined(PNG_WRITE_COMPRESSED_TEXT_SUPPORTED) || \
+    defined(PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED)
+   int zlib_text_level;            /* holds zlib compression level */
+   int zlib_text_method;           /* holds zlib compression method */
+   int zlib_text_window_bits;      /* holds zlib compression window bits */
+   int zlib_text_mem_level;        /* holds zlib compression memory level */
+   int zlib_text_strategy;         /* holds zlib compression strategy */
+#endif
+/* End of material added at libpng 1.5.4 */
+   png_uint_32 width;         /* width of image in pixels */
+   png_uint_32 height;        /* height of image in pixels */
+   png_uint_32 num_rows;      /* number of rows in current pass */
+   png_uint_32 usr_width;     /* width of row at start of write */
+   png_size_t rowbytes;       /* size of row in bytes */
+   png_uint_32 iwidth;        /* width of current interlaced row in pixels */
+   png_uint_32 row_number;    /* current row in interlace pass */
+   png_uint_32 chunk_name;    /* PNG_CHUNK() id of current chunk */
+   png_bytep prev_row;        /* buffer to save previous (unfiltered) row.
+                               * This is a pointer into big_prev_row
+                               */
+   png_bytep row_buf;         /* buffer to save current (unfiltered) row.
+                               * This is a pointer into big_row_buf
+                               */
+   png_bytep sub_row;         /* buffer to save "sub" row when filtering */
+   png_bytep up_row;          /* buffer to save "up" row when filtering */
+   png_bytep avg_row;         /* buffer to save "avg" row when filtering */
+   png_bytep paeth_row;       /* buffer to save "Paeth" row when filtering */
+   png_size_t info_rowbytes;  /* Added in 1.5.4: cache of updated row bytes */
+   png_uint_32 idat_size;     /* current IDAT size for read */
+   png_uint_32 crc;           /* current chunk CRC value */
+   png_colorp palette;        /* palette from the input file */
+   png_uint_16 num_palette;   /* number of color entries in palette */
+   png_uint_16 num_trans;     /* number of transparency values */
+   png_byte compression;      /* file compression type (always 0) */
+   png_byte filter;           /* file filter type (always 0) */
+   png_byte interlaced;       /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
+   png_byte pass;             /* current interlace pass (0 - 6) */
+   png_byte do_filter;        /* row filter flags (see PNG_FILTER_ below ) */
+   png_byte color_type;       /* color type of file */
+   png_byte bit_depth;        /* bit depth of file */
+   png_byte usr_bit_depth;    /* bit depth of users row: write only */
+   png_byte pixel_depth;      /* number of bits per pixel */
+   png_byte channels;         /* number of channels in file */
+   png_byte usr_channels;     /* channels at start of write: write only */
+   png_byte sig_bytes;        /* magic bytes read/written from start of file */
+   png_byte maximum_pixel_depth;
+                              /* pixel depth used for the row buffers */
+   png_byte transformed_pixel_depth;
+                              /* pixel depth after read/write transforms */
+   png_byte io_chunk_string[5];
+                              /* string name of chunk */
+#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
+   png_uint_16 filler;           /* filler bytes for pixel expansion */
+#endif
+#if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
+   defined(PNG_READ_ALPHA_MODE_SUPPORTED)
+   png_byte background_gamma_type;
+   png_fixed_point background_gamma;
+   png_color_16 background;   /* background color in screen gamma space */
+#ifdef PNG_READ_GAMMA_SUPPORTED
+   png_color_16 background_1; /* background normalized to gamma 1.0 */
+#endif
+#endif /* PNG_bKGD_SUPPORTED */
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+   png_flush_ptr output_flush_fn; /* Function for flushing output */
+   png_uint_32 flush_dist;    /* how many rows apart to flush, 0 - no flush */
+   png_uint_32 flush_rows;    /* number of rows written since last flush */
+#endif
+#ifdef PNG_READ_GAMMA_SUPPORTED
+   int gamma_shift;      /* number of "insignificant" bits in 16-bit gamma */
+   png_fixed_point gamma;        /* file gamma value */
+   png_fixed_point screen_gamma; /* screen gamma value (display_exponent) */
+   png_bytep gamma_table;     /* gamma table for 8-bit depth files */
+   png_uint_16pp gamma_16_table; /* gamma table for 16-bit depth files */
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
+   defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \
+   defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+   png_bytep gamma_from_1;    /* converts from 1.0 to screen */
+   png_bytep gamma_to_1;      /* converts from file to 1.0 */
+   png_uint_16pp gamma_16_from_1; /* converts from 1.0 to screen */
+   png_uint_16pp gamma_16_to_1; /* converts from file to 1.0 */
+#endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */
+#endif
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_sBIT_SUPPORTED)
+   png_color_8 sig_bit;       /* significant bits in each available channel */
+#endif
+#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
+   png_color_8 shift;         /* shift for significant bit tranformation */
+#endif
+#if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \
+ || defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+   png_bytep trans_alpha;           /* alpha values for paletted files */
+   png_color_16 trans_color;  /* transparent color for non-paletted files */
+#endif
+   png_read_status_ptr read_row_fn;   /* called after each row is decoded */
+   png_write_status_ptr write_row_fn; /* called after each row is encoded */
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+   png_progressive_info_ptr info_fn; /* called after header data fully read */
+   png_progressive_row_ptr row_fn;   /* called after a prog. row is decoded */
+   png_progressive_end_ptr end_fn;   /* called after image is complete */
+   png_bytep save_buffer_ptr;        /* current location in save_buffer */
+   png_bytep save_buffer;            /* buffer for previously read data */
+   png_bytep current_buffer_ptr;     /* current location in current_buffer */
+   png_bytep current_buffer;         /* buffer for recently used data */
+   png_uint_32 push_length;          /* size of current input chunk */
+   png_uint_32 skip_length;          /* bytes to skip in input data */
+   png_size_t save_buffer_size;      /* amount of data now in save_buffer */
+   png_size_t save_buffer_max;       /* total size of save_buffer */
+   png_size_t buffer_size;           /* total amount of available input data */
+   png_size_t current_buffer_size;   /* amount of data now in current_buffer */
+   int process_mode;                 /* what push library is currently doing */
+   int cur_palette;                  /* current push library palette index */
+#  ifdef PNG_TEXT_SUPPORTED
+     png_size_t current_text_size;   /* current size of text input data */
+     png_size_t current_text_left;   /* how much text left to read in input */
+     png_charp current_text;         /* current text chunk buffer */
+     png_charp current_text_ptr;     /* current location in current_text */
+#  endif /* PNG_PROGRESSIVE_READ_SUPPORTED && PNG_TEXT_SUPPORTED */
+#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
+#if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
+/* For the Borland special 64K segment handler */
+   png_bytepp offset_table_ptr;
+   png_bytep offset_table;
+   png_uint_16 offset_table_number;
+   png_uint_16 offset_table_count;
+   png_uint_16 offset_table_count_free;
+#endif
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+   png_bytep palette_lookup; /* lookup table for quantizing */
+   png_bytep quantize_index; /* index translation for palette files */
+#endif
+#if defined(PNG_READ_QUANTIZE_SUPPORTED) || defined(PNG_hIST_SUPPORTED)
+   png_uint_16p hist;                /* histogram */
+#endif
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+   png_byte heuristic_method;        /* heuristic for row filter selection */
+   png_byte num_prev_filters;        /* number of weights for previous rows */
+   png_bytep prev_filters;           /* filter type(s) of previous row(s) */
+   png_uint_16p filter_weights;      /* weight(s) for previous line(s) */
+   png_uint_16p inv_filter_weights;  /* 1/weight(s) for previous line(s) */
+   png_uint_16p filter_costs;        /* relative filter calculation cost */
+   png_uint_16p inv_filter_costs;    /* 1/relative filter calculation cost */
+#endif
+#ifdef PNG_TIME_RFC1123_SUPPORTED
+   char time_buffer[29]; /* String to hold RFC 1123 time text */
+#endif
+/* New members added in libpng-1.0.6 */
+   png_uint_32 free_me;    /* flags items libpng is responsible for freeing */
+#ifdef PNG_USER_CHUNKS_SUPPORTED
+   png_voidp user_chunk_ptr;
+   png_user_chunk_ptr read_user_chunk_fn; /* user read chunk handler */
+#endif
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+   int num_chunk_list;
+   png_bytep chunk_list;
+#endif
+#ifdef PNG_READ_sRGB_SUPPORTED
+   /* Added in 1.5.5 to record an sRGB chunk in the png. */
+   png_byte is_sRGB;
+#endif
+/* New members added in libpng-1.0.3 */
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+   png_byte rgb_to_gray_status;
+   /* Added in libpng 1.5.5 to record setting of coefficients: */
+   png_byte rgb_to_gray_coefficients_set;
+   /* These were changed from png_byte in libpng-1.0.6 */
+   png_uint_16 rgb_to_gray_red_coeff;
+   png_uint_16 rgb_to_gray_green_coeff;
+   /* deleted in 1.5.5: rgb_to_gray_blue_coeff; */
+#endif
+/* New member added in libpng-1.0.4 (renamed in 1.0.9) */
+#if defined(PNG_MNG_FEATURES_SUPPORTED)
+/* Changed from png_byte to png_uint_32 at version 1.2.0 */
+   png_uint_32 mng_features_permitted;
+#endif
+/* New member added in libpng-1.0.9, ifdef'ed out in 1.0.12, enabled in 1.2.0 */
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+   png_byte filter_type;
+#endif
+/* New members added in libpng-1.2.0 */
+/* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */
+#ifdef PNG_USER_MEM_SUPPORTED
+   png_voidp mem_ptr;             /* user supplied struct for mem functions */
+   png_malloc_ptr malloc_fn;      /* function for allocating memory */
+   png_free_ptr free_fn;          /* function for freeing memory */
+#endif
+/* New member added in libpng-1.0.13 and 1.2.0 */
+   png_bytep big_row_buf;         /* buffer to save current (unfiltered) row */
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+/* The following three members were added at version 1.0.14 and 1.2.4 */
+   png_bytep quantize_sort;          /* working sort array */
+   png_bytep index_to_palette;       /* where the original index currently is
+                                        in the palette */
+   png_bytep palette_to_index;       /* which original index points to this
+                                         palette color */
+#endif
+/* New members added in libpng-1.0.16 and 1.2.6 */
+   png_byte compression_type;
+#ifdef PNG_USER_LIMITS_SUPPORTED
+   png_uint_32 user_width_max;
+   png_uint_32 user_height_max;
+   /* Added in libpng-1.4.0: Total number of sPLT, text, and unknown
+    * chunks that can be stored (0 means unlimited).
+    */
+   png_uint_32 user_chunk_cache_max;
+   /* Total memory that a zTXt, sPLT, iTXt, iCCP, or unknown chunk
+    * can occupy when decompressed.  0 means unlimited.
+    */
+   png_alloc_size_t user_chunk_malloc_max;
+#endif
+/* New member added in libpng-1.0.25 and 1.2.17 */
+#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
+   /* Storage for unknown chunk that the library doesn't recognize. */
+   png_unknown_chunk unknown_chunk;
+#endif
+/* New member added in libpng-1.2.26 */
+  png_size_t old_big_row_buf_size;
+/* New member added in libpng-1.2.30 */
+  png_charp chunkdata;  /* buffer for reading chunk data */
+#ifdef PNG_IO_STATE_SUPPORTED
+/* New member added in libpng-1.4.0 */
+   png_uint_32 io_state;
+#endif
+/* New member added in libpng-1.5.6 */
+   png_bytep big_prev_row;
+   void (*read_filter[PNG_FILTER_VALUE_LAST-1])(png_row_infop row_info,
+      png_bytep row, png_const_bytep prev_row);
+};
+#endif /* PNGSTRUCT_H */
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngtest.c b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngtest.c
new file mode 100644
index 0000000..8405174
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngtest.c
@@ -0,0 +1,1820 @@
+/* pngtest.c - a simple test program to test libpng
+ *
+ * Last changed in libpng 1.5.6 [November 3, 2011]
+ * Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * This program reads in a PNG image, writes it out again, and then
+ * compares the two files.  If the files are identical, this shows that
+ * the basic chunk handling, filtering, and (de)compression code is working
+ * properly.  It does not currently test all of the transforms, although
+ * it probably should.
+ *
+ * The program will report "FAIL" in certain legitimate cases:
+ * 1) when the compression level or filter selection method is changed.
+ * 2) when the maximum IDAT size (PNG_ZBUF_SIZE in pngconf.h) is not 8192.
+ * 3) unknown unsafe-to-copy ancillary chunks or unknown critical chunks
+ *    exist in the input file.
+ * 4) others not listed here...
+ * In these cases, it is best to check with another tool such as "pngcheck"
+ * to see what the differences between the two files are.
+ *
+ * If a filename is given on the command-line, then this file is used
+ * for the input, rather than the default "pngtest.png".  This allows
+ * testing a wide variety of files easily.  You can also test a number
+ * of files at once by typing "pngtest -m file1.png file2.png ..."
+ */
+#define _POSIX_SOURCE 1
+#include "zlib.h"
+#include "png.h"
+/* Copied from pngpriv.h but only used in error messages below. */
+#ifndef PNG_ZBUF_SIZE
+#  define PNG_ZBUF_SIZE 8192
+#endif
+#  include <stdio.h>
+#  include <stdlib.h>
+#  include <string.h>
+#  define FCLOSE(file) fclose(file)
+#ifndef PNG_STDIO_SUPPORTED
+typedef FILE                * png_FILE_p;
+#endif
+/* Makes pngtest verbose so we can find problems. */
+#ifndef PNG_DEBUG
+#  define PNG_DEBUG 0
+#endif
+#if PNG_DEBUG > 1
+#  define pngtest_debug(m)        ((void)fprintf(stderr, m "\n"))
+#  define pngtest_debug1(m,p1)    ((void)fprintf(stderr, m "\n", p1))
+#  define pngtest_debug2(m,p1,p2) ((void)fprintf(stderr, m "\n", p1, p2))
+#else
+#  define pngtest_debug(m)        ((void)0)
+#  define pngtest_debug1(m,p1)    ((void)0)
+#  define pngtest_debug2(m,p1,p2) ((void)0)
+#endif
+#if !PNG_DEBUG
+#  define SINGLE_ROWBUF_ALLOC  /* Makes buffer overruns easier to nail */
+#endif
+/* The code uses memcmp and memcpy on large objects (typically row pointers) so
+ * it is necessary to do soemthing special on certain architectures, note that
+ * the actual support for this was effectively removed in 1.4, so only the
+ * memory remains in this program:
+ */
+#define CVT_PTR(ptr)         (ptr)
+#define CVT_PTR_NOCHECK(ptr) (ptr)
+#define png_memcmp  memcmp
+#define png_memcpy  memcpy
+#define png_memset  memset
+/* Turn on CPU timing
+#define PNGTEST_TIMING
+*/
+#ifndef PNG_FLOATING_POINT_SUPPORTED
+#undef PNGTEST_TIMING
+#endif
+#ifdef PNGTEST_TIMING
+static float t_start, t_stop, t_decode, t_encode, t_misc;
+#include <time.h>
+#endif
+#ifdef PNG_TIME_RFC1123_SUPPORTED
+#define PNG_tIME_STRING_LENGTH 29
+static int tIME_chunk_present = 0;
+static char tIME_string[PNG_tIME_STRING_LENGTH] = "tIME chunk is not present";
+#endif
+static int verbose = 0;
+static int strict = 0;
+int test_one_file PNGARG((PNG_CONST char *inname, PNG_CONST char *outname));
+#ifdef __TURBOC__
+#include <mem.h>
+#endif
+/* Defined so I can write to a file on gui/windowing platforms */
+/*  #define STDERR stderr  */
+#define STDERR stdout   /* For DOS */
+/* Define png_jmpbuf() in case we are using a pre-1.0.6 version of libpng */
+#ifndef png_jmpbuf
+#  define png_jmpbuf(png_ptr) png_ptr->jmpbuf
+#endif
+/* Example of using row callbacks to make a simple progress meter */
+static int status_pass = 1;
+static int status_dots_requested = 0;
+static int status_dots = 1;
+void PNGCBAPI
+read_row_callback(png_structp png_ptr, png_uint_32 row_number, int pass);
+void PNGCBAPI
+read_row_callback(png_structp png_ptr, png_uint_32 row_number, int pass)
+{
+   if (png_ptr == NULL || row_number > PNG_UINT_31_MAX)
+      return;
+   if (status_pass != pass)
+   {
+      fprintf(stdout, "\n Pass %d: ", pass);
+      status_pass = pass;
+      status_dots = 31;
+   }
+   status_dots--;
+   if (status_dots == 0)
+   {
+      fprintf(stdout, "\n         ");
+      status_dots=30;
+   }
+   fprintf(stdout, "r");
+}
+void PNGCBAPI
+write_row_callback(png_structp png_ptr, png_uint_32 row_number, int pass);
+void PNGCBAPI
+write_row_callback(png_structp png_ptr, png_uint_32 row_number, int pass)
+{
+   if (png_ptr == NULL || row_number > PNG_UINT_31_MAX || pass > 7)
+      return;
+   fprintf(stdout, "w");
+}
+#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
+/* Example of using user transform callback (we don't transform anything,
+ * but merely examine the row filters.  We set this to 256 rather than
+ * 5 in case illegal filter values are present.)
+ */
+static png_uint_32 filters_used[256];
+void PNGCBAPI
+count_filters(png_structp png_ptr, png_row_infop row_info, png_bytep data);
+void PNGCBAPI
+count_filters(png_structp png_ptr, png_row_infop row_info, png_bytep data)
+{
+   if (png_ptr != NULL && row_info != NULL)
+      ++filters_used[*(data - 1)];
+}
+#endif
+#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
+/* Example of using user transform callback (we don't transform anything,
+ * but merely count the zero samples)
+ */
+static png_uint_32 zero_samples;
+void PNGCBAPI
+count_zero_samples(png_structp png_ptr, png_row_infop row_info, png_bytep data);
+void PNGCBAPI
+count_zero_samples(png_structp png_ptr, png_row_infop row_info, png_bytep data)
+{
+   png_bytep dp = data;
+   if (png_ptr == NULL)
+      return;
+   /* Contents of row_info:
+    *  png_uint_32 width      width of row
+    *  png_uint_32 rowbytes   number of bytes in row
+    *  png_byte color_type    color type of pixels
+    *  png_byte bit_depth     bit depth of samples
+    *  png_byte channels      number of channels (1-4)
+    *  png_byte pixel_depth   bits per pixel (depth*channels)
+    */
+    /* Counts the number of zero samples (or zero pixels if color_type is 3 */
+    if (row_info->color_type == 0 || row_info->color_type == 3)
+    {
+       int pos = 0;
+       png_uint_32 n, nstop;
+       for (n = 0, nstop=row_info->width; n<nstop; n++)
+       {
+          if (row_info->bit_depth == 1)
+          {
+             if (((*dp << pos++ ) & 0x80) == 0)
+                zero_samples++;
+             if (pos == 8)
+             {
+                pos = 0;
+                dp++;
+             }
+          }
+          if (row_info->bit_depth == 2)
+          {
+             if (((*dp << (pos+=2)) & 0xc0) == 0)
+                zero_samples++;
+             if (pos == 8)
+             {
+                pos = 0;
+                dp++;
+             }
+          }
+          if (row_info->bit_depth == 4)
+          {
+             if (((*dp << (pos+=4)) & 0xf0) == 0)
+                zero_samples++;
+             if (pos == 8)
+             {
+                pos = 0;
+                dp++;
+             }
+          }
+          if (row_info->bit_depth == 8)
+             if (*dp++ == 0)
+                zero_samples++;
+          if (row_info->bit_depth == 16)
+          {
+             if ((*dp | *(dp+1)) == 0)
+                zero_samples++;
+             dp+=2;
+          }
+       }
+    }
+    else /* Other color types */
+    {
+       png_uint_32 n, nstop;
+       int channel;
+       int color_channels = row_info->channels;
+       if (row_info->color_type > 3)color_channels--;
+       for (n = 0, nstop=row_info->width; n<nstop; n++)
+       {
+          for (channel = 0; channel < color_channels; channel++)
+          {
+             if (row_info->bit_depth == 8)
+                if (*dp++ == 0)
+                   zero_samples++;
+             if (row_info->bit_depth == 16)
+             {
+                if ((*dp | *(dp+1)) == 0)
+                   zero_samples++;
+                dp+=2;
+             }
+          }
+          if (row_info->color_type > 3)
+          {
+             dp++;
+             if (row_info->bit_depth == 16)
+                dp++;
+          }
+       }
+    }
+}
+#endif /* PNG_WRITE_USER_TRANSFORM_SUPPORTED */
+static int wrote_question = 0;
+#ifndef PNG_STDIO_SUPPORTED
+/* START of code to validate stdio-free compilation */
+/* These copies of the default read/write functions come from pngrio.c and
+ * pngwio.c.  They allow "don't include stdio" testing of the library.
+ * This is the function that does the actual reading of data.  If you are
+ * not reading from a standard C stream, you should create a replacement
+ * read_data function and use it at run time with png_set_read_fn(), rather
+ * than changing the library.
+ */
+#ifdef PNG_IO_STATE_SUPPORTED
+void
+pngtest_check_io_state(png_structp png_ptr, png_size_t data_length,
+   png_uint_32 io_op);
+void
+pngtest_check_io_state(png_structp png_ptr, png_size_t data_length,
+   png_uint_32 io_op)
+{
+   png_uint_32 io_state = png_get_io_state(png_ptr);
+   int err = 0;
+   /* Check if the current operation (reading / writing) is as expected. */
+   if ((io_state & PNG_IO_MASK_OP) != io_op)
+      png_error(png_ptr, "Incorrect operation in I/O state");
+   /* Check if the buffer size specific to the current location
+    * (file signature / header / data / crc) is as expected.
+    */
+   switch (io_state & PNG_IO_MASK_LOC)
+   {
+   case PNG_IO_SIGNATURE:
+      if (data_length > 8)
+         err = 1;
+      break;
+   case PNG_IO_CHUNK_HDR:
+      if (data_length != 8)
+         err = 1;
+      break;
+   case PNG_IO_CHUNK_DATA:
+      break;  /* no restrictions here */
+   case PNG_IO_CHUNK_CRC:
+      if (data_length != 4)
+         err = 1;
+      break;
+   default:
+      err = 1;  /* uninitialized */
+   }
+   if (err)
+      png_error(png_ptr, "Bad I/O state or buffer size");
+}
+#endif
+#ifndef USE_FAR_KEYWORD
+static void PNGCBAPI
+pngtest_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
+{
+   png_size_t check = 0;
+   png_voidp io_ptr;
+   /* fread() returns 0 on error, so it is OK to store this in a png_size_t
+    * instead of an int, which is what fread() actually returns.
+    */
+   io_ptr = png_get_io_ptr(png_ptr);
+   if (io_ptr != NULL)
+   {
+      check = fread(data, 1, length, (png_FILE_p)io_ptr);
+   }
+   if (check != length)
+   {
+      png_error(png_ptr, "Read Error");
+   }
+#ifdef PNG_IO_STATE_SUPPORTED
+   pngtest_check_io_state(png_ptr, length, PNG_IO_READING);
+#endif
+}
+#else
+/* This is the model-independent version. Since the standard I/O library
+   can't handle far buffers in the medium and small models, we have to copy
+   the data.
+*/
+#define NEAR_BUF_SIZE 1024
+#define MIN(a,b) (a <= b ? a : b)
+static void PNGCBAPI
+pngtest_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
+{
+   png_size_t check;
+   png_byte *n_data;
+   png_FILE_p io_ptr;
+   /* Check if data really is near. If so, use usual code. */
+   n_data = (png_byte *)CVT_PTR_NOCHECK(data);
+   io_ptr = (png_FILE_p)CVT_PTR(png_get_io_ptr(png_ptr));
+   if ((png_bytep)n_data == data)
+   {
+      check = fread(n_data, 1, length, io_ptr);
+   }
+   else
+   {
+      png_byte buf[NEAR_BUF_SIZE];
+      png_size_t read, remaining, err;
+      check = 0;
+      remaining = length;
+      do
+      {
+         read = MIN(NEAR_BUF_SIZE, remaining);
+         err = fread(buf, 1, 1, io_ptr);
+         png_memcpy(data, buf, read); /* Copy far buffer to near buffer */
+         if (err != read)
+            break;
+         else
+            check += err;
+         data += read;
+         remaining -= read;
+      }
+      while (remaining != 0);
+   }
+   if (check != length)
+      png_error(png_ptr, "Read Error");
+#ifdef PNG_IO_STATE_SUPPORTED
+   pngtest_check_io_state(png_ptr, length, PNG_IO_READING);
+#endif
+}
+#endif /* USE_FAR_KEYWORD */
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+static void PNGCBAPI
+pngtest_flush(png_structp png_ptr)
+{
+   /* Do nothing; fflush() is said to be just a waste of energy. */
+   PNG_UNUSED(png_ptr)   /* Stifle compiler warning */
+}
+#endif
+/* This is the function that does the actual writing of data.  If you are
+ * not writing to a standard C stream, you should create a replacement
+ * write_data function and use it at run time with png_set_write_fn(), rather
+ * than changing the library.
+ */
+#ifndef USE_FAR_KEYWORD
+static void PNGCBAPI
+pngtest_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
+{
+   png_size_t check;
+   check = fwrite(data, 1, length, (png_FILE_p)png_get_io_ptr(png_ptr));
+   if (check != length)
+   {
+      png_error(png_ptr, "Write Error");
+   }
+#ifdef PNG_IO_STATE_SUPPORTED
+   pngtest_check_io_state(png_ptr, length, PNG_IO_WRITING);
+#endif
+}
+#else
+/* This is the model-independent version. Since the standard I/O library
+   can't handle far buffers in the medium and small models, we have to copy
+   the data.
+*/
+#define NEAR_BUF_SIZE 1024
+#define MIN(a,b) (a <= b ? a : b)
+static void PNGCBAPI
+pngtest_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
+{
+   png_size_t check;
+   png_byte *near_data;  /* Needs to be "png_byte *" instead of "png_bytep" */
+   png_FILE_p io_ptr;
+   /* Check if data really is near. If so, use usual code. */
+   near_data = (png_byte *)CVT_PTR_NOCHECK(data);
+   io_ptr = (png_FILE_p)CVT_PTR(png_get_io_ptr(png_ptr));
+   if ((png_bytep)near_data == data)
+   {
+      check = fwrite(near_data, 1, length, io_ptr);
+   }
+   else
+   {
+      png_byte buf[NEAR_BUF_SIZE];
+      png_size_t written, remaining, err;
+      check = 0;
+      remaining = length;
+      do
+      {
+         written = MIN(NEAR_BUF_SIZE, remaining);
+         png_memcpy(buf, data, written); /* Copy far buffer to near buffer */
+         err = fwrite(buf, 1, written, io_ptr);
+         if (err != written)
+            break;
+         else
+            check += err;
+         data += written;
+         remaining -= written;
+      }
+      while (remaining != 0);
+   }
+   if (check != length)
+   {
+      png_error(png_ptr, "Write Error");
+   }
+#ifdef PNG_IO_STATE_SUPPORTED
+   pngtest_check_io_state(png_ptr, length, PNG_IO_WRITING);
+#endif
+}
+#endif /* USE_FAR_KEYWORD */
+/* This function is called when there is a warning, but the library thinks
+ * it can continue anyway.  Replacement functions don't have to do anything
+ * here if you don't want to.  In the default configuration, png_ptr is
+ * not used, but it is passed in case it may be useful.
+ */
+static void PNGCBAPI
+pngtest_warning(png_structp png_ptr, png_const_charp message)
+{
+   PNG_CONST char *name = "UNKNOWN (ERROR!)";
+   char *test;
+   test = png_get_error_ptr(png_ptr);
+   if (test == NULL)
+     fprintf(STDERR, "%s: libpng warning: %s\n", name, message);
+   else
+     fprintf(STDERR, "%s: libpng warning: %s\n", test, message);
+}
+/* This is the default error handling function.  Note that replacements for
+ * this function MUST NOT RETURN, or the program will likely crash.  This
+ * function is used by default, or if the program supplies NULL for the
+ * error function pointer in png_set_error_fn().
+ */
+static void PNGCBAPI
+pngtest_error(png_structp png_ptr, png_const_charp message)
+{
+   pngtest_warning(png_ptr, message);
+   /* We can return because png_error calls the default handler, which is
+    * actually OK in this case.
+    */
+}
+#endif /* !PNG_STDIO_SUPPORTED */
+/* END of code to validate stdio-free compilation */
+/* START of code to validate memory allocation and deallocation */
+#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
+/* Allocate memory.  For reasonable files, size should never exceed
+ * 64K.  However, zlib may allocate more then 64K if you don't tell
+ * it not to.  See zconf.h and png.h for more information.  zlib does
+ * need to allocate exactly 64K, so whatever you call here must
+ * have the ability to do that.
+ *
+ * This piece of code can be compiled to validate max 64K allocations
+ * by setting MAXSEG_64K in zlib zconf.h *or* PNG_MAX_MALLOC_64K.
+ */
+typedef struct memory_information
+{
+   png_alloc_size_t          size;
+   png_voidp                 pointer;
+   struct memory_information FAR *next;
+} memory_information;
+typedef memory_information FAR *memory_infop;
+static memory_infop pinformation = NULL;
+static int current_allocation = 0;
+static int maximum_allocation = 0;
+static int total_allocation = 0;
+static int num_allocations = 0;
+png_voidp PNGCBAPI png_debug_malloc PNGARG((png_structp png_ptr,
+    png_alloc_size_t size));
+void PNGCBAPI png_debug_free PNGARG((png_structp png_ptr, png_voidp ptr));
+png_voidp
+PNGCBAPI png_debug_malloc(png_structp png_ptr, png_alloc_size_t size)
+{
+   /* png_malloc has already tested for NULL; png_create_struct calls
+    * png_debug_malloc directly, with png_ptr == NULL which is OK
+    */
+   if (size == 0)
+      return (NULL);
+   /* This calls the library allocator twice, once to get the requested
+      buffer and once to get a new free list entry. */
+   {
+      /* Disable malloc_fn and free_fn */
+      memory_infop pinfo;
+      png_set_mem_fn(png_ptr, NULL, NULL, NULL);
+      pinfo = (memory_infop)png_malloc(png_ptr,
+         png_sizeof(*pinfo));
+      pinfo->size = size;
+      current_allocation += size;
+      total_allocation += size;
+      num_allocations ++;
+      if (current_allocation > maximum_allocation)
+         maximum_allocation = current_allocation;
+      pinfo->pointer = png_malloc(png_ptr, size);
+      /* Restore malloc_fn and free_fn */
+      png_set_mem_fn(png_ptr,
+          NULL, png_debug_malloc, png_debug_free);
+      if (size != 0 && pinfo->pointer == NULL)
+      {
+         current_allocation -= size;
+         total_allocation -= size;
+         png_error(png_ptr,
+           "out of memory in pngtest->png_debug_malloc");
+      }
+      pinfo->next = pinformation;
+      pinformation = pinfo;
+      /* Make sure the caller isn't assuming zeroed memory. */
+      png_memset(pinfo->pointer, 0xdd, pinfo->size);
+      if (verbose)
+         printf("png_malloc %lu bytes at %p\n", (unsigned long)size,
+            pinfo->pointer);
+      return (png_voidp)(pinfo->pointer);
+   }
+}
+/* Free a pointer.  It is removed from the list at the same time. */
+void PNGCBAPI
+png_debug_free(png_structp png_ptr, png_voidp ptr)
+{
+   if (png_ptr == NULL)
+      fprintf(STDERR, "NULL pointer to png_debug_free.\n");
+   if (ptr == 0)
+   {
+#if 0 /* This happens all the time. */
+      fprintf(STDERR, "WARNING: freeing NULL pointer\n");
+#endif
+      return;
+   }
+   /* Unlink the element from the list. */
+   {
+      memory_infop FAR *ppinfo = &pinformation;
+      for (;;)
+      {
+         memory_infop pinfo = *ppinfo;
+         if (pinfo->pointer == ptr)
+         {
+            *ppinfo = pinfo->next;
+            current_allocation -= pinfo->size;
+            if (current_allocation < 0)
+               fprintf(STDERR, "Duplicate free of memory\n");
+            /* We must free the list element too, but first kill
+               the memory that is to be freed. */
+            png_memset(ptr, 0x55, pinfo->size);
+            png_free_default(png_ptr, pinfo);
+            pinfo = NULL;
+            break;
+         }
+         if (pinfo->next == NULL)
+         {
+            fprintf(STDERR, "Pointer %x not found\n", (unsigned int)ptr);
+            break;
+         }
+         ppinfo = &pinfo->next;
+      }
+   }
+   /* Finally free the data. */
+   if (verbose)
+      printf("Freeing %p\n", ptr);
+   png_free_default(png_ptr, ptr);
+   ptr = NULL;
+}
+#endif /* PNG_USER_MEM_SUPPORTED && PNG_DEBUG */
+/* END of code to test memory allocation/deallocation */
+/* Demonstration of user chunk support of the sTER and vpAg chunks */
+#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
+/* (sTER is a public chunk not yet known by libpng.  vpAg is a private
+chunk used in ImageMagick to store "virtual page" size).  */
+static png_uint_32 user_chunk_data[4];
+    /* 0: sTER mode + 1
+     * 1: vpAg width
+     * 2: vpAg height
+     * 3: vpAg units
+     */
+static int PNGCBAPI read_user_chunk_callback(png_struct *png_ptr,
+   png_unknown_chunkp chunk)
+{
+   png_uint_32
+     *my_user_chunk_data;
+   /* Return one of the following:
+    *    return (-n);  chunk had an error
+    *    return (0);  did not recognize
+    *    return (n);  success
+    *
+    * The unknown chunk structure contains the chunk data:
+    * png_byte name[5];
+    * png_byte *data;
+    * png_size_t size;
+    *
+    * Note that libpng has already taken care of the CRC handling.
+    */
+   if (chunk->name[0] == 115 && chunk->name[1] ==  84 &&     /* s  T */
+       chunk->name[2] ==  69 && chunk->name[3] ==  82)       /* E  R */
+      {
+         /* Found sTER chunk */
+         if (chunk->size != 1)
+            return (-1); /* Error return */
+         if (chunk->data[0] != 0 && chunk->data[0] != 1)
+            return (-1);  /* Invalid mode */
+         my_user_chunk_data=(png_uint_32 *) png_get_user_chunk_ptr(png_ptr);
+         my_user_chunk_data[0]=chunk->data[0]+1;
+         return (1);
+      }
+   if (chunk->name[0] != 118 || chunk->name[1] != 112 ||    /* v  p */
+       chunk->name[2] !=  65 || chunk->name[3] != 103)      /* A  g */
+      return (0); /* Did not recognize */
+   /* Found ImageMagick vpAg chunk */
+   if (chunk->size != 9)
+      return (-1); /* Error return */
+   my_user_chunk_data=(png_uint_32 *) png_get_user_chunk_ptr(png_ptr);
+   my_user_chunk_data[1]=png_get_uint_31(png_ptr, chunk->data);
+   my_user_chunk_data[2]=png_get_uint_31(png_ptr, chunk->data + 4);
+   my_user_chunk_data[3]=(png_uint_32)chunk->data[8];
+   return (1);
+}
+#endif
+/* END of code to demonstrate user chunk support */
+/* Test one file */
+int
+test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
+{
+   static png_FILE_p fpin;
+   static png_FILE_p fpout;  /* "static" prevents setjmp corruption */
+   png_structp read_ptr;
+   png_infop read_info_ptr, end_info_ptr;
+#ifdef PNG_WRITE_SUPPORTED
+   png_structp write_ptr;
+   png_infop write_info_ptr;
+   png_infop write_end_info_ptr;
+#else
+   png_structp write_ptr = NULL;
+   png_infop write_info_ptr = NULL;
+   png_infop write_end_info_ptr = NULL;
+#endif
+   png_bytep row_buf;
+   png_uint_32 y;
+   png_uint_32 width, height;
+   int num_pass, pass;
+   int bit_depth, color_type;
+#ifdef PNG_SETJMP_SUPPORTED
+#ifdef USE_FAR_KEYWORD
+   jmp_buf tmp_jmpbuf;
+#endif
+#endif
+   char inbuf[256], outbuf[256];
+   row_buf = NULL;
+   if ((fpin = fopen(inname, "rb")) == NULL)
+   {
+      fprintf(STDERR, "Could not find input file %s\n", inname);
+      return (1);
+   }
+   if ((fpout = fopen(outname, "wb")) == NULL)
+   {
+      fprintf(STDERR, "Could not open output file %s\n", outname);
+      FCLOSE(fpin);
+      return (1);
+   }
+   pngtest_debug("Allocating read and write structures");
+#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
+   read_ptr =
+      png_create_read_struct_2(PNG_LIBPNG_VER_STRING, NULL,
+      NULL, NULL, NULL, png_debug_malloc, png_debug_free);
+#else
+   read_ptr =
+      png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+#endif
+#ifndef PNG_STDIO_SUPPORTED
+   png_set_error_fn(read_ptr, (png_voidp)inname, pngtest_error,
+       pngtest_warning);
+#endif
+#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
+   user_chunk_data[0] = 0;
+   user_chunk_data[1] = 0;
+   user_chunk_data[2] = 0;
+   user_chunk_data[3] = 0;
+   png_set_read_user_chunk_fn(read_ptr, user_chunk_data,
+     read_user_chunk_callback);
+#endif
+#ifdef PNG_WRITE_SUPPORTED
+#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
+   write_ptr =
+      png_create_write_struct_2(PNG_LIBPNG_VER_STRING, NULL,
+      NULL, NULL, NULL, png_debug_malloc, png_debug_free);
+#else
+   write_ptr =
+      png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+#endif
+#ifndef PNG_STDIO_SUPPORTED
+   png_set_error_fn(write_ptr, (png_voidp)inname, pngtest_error,
+       pngtest_warning);
+#endif
+#endif
+   pngtest_debug("Allocating read_info, write_info and end_info structures");
+   read_info_ptr = png_create_info_struct(read_ptr);
+   end_info_ptr = png_create_info_struct(read_ptr);
+#ifdef PNG_WRITE_SUPPORTED
+   write_info_ptr = png_create_info_struct(write_ptr);
+   write_end_info_ptr = png_create_info_struct(write_ptr);
+#endif
+#ifdef PNG_SETJMP_SUPPORTED
+   pngtest_debug("Setting jmpbuf for read struct");
+#ifdef USE_FAR_KEYWORD
+   if (setjmp(tmp_jmpbuf))
+#else
+   if (setjmp(png_jmpbuf(read_ptr)))
+#endif
+   {
+      fprintf(STDERR, "%s -> %s: libpng read error\n", inname, outname);
+      png_free(read_ptr, row_buf);
+      row_buf = NULL;
+      png_destroy_read_struct(&read_ptr, &read_info_ptr, &end_info_ptr);
+#ifdef PNG_WRITE_SUPPORTED
+      png_destroy_info_struct(write_ptr, &write_end_info_ptr);
+      png_destroy_write_struct(&write_ptr, &write_info_ptr);
+#endif
+      FCLOSE(fpin);
+      FCLOSE(fpout);
+      return (1);
+   }
+#ifdef USE_FAR_KEYWORD
+   png_memcpy(png_jmpbuf(read_ptr), tmp_jmpbuf, png_sizeof(jmp_buf));
+#endif
+#ifdef PNG_WRITE_SUPPORTED
+   pngtest_debug("Setting jmpbuf for write struct");
+#ifdef USE_FAR_KEYWORD
+   if (setjmp(tmp_jmpbuf))
+#else
+   if (setjmp(png_jmpbuf(write_ptr)))
+#endif
+   {
+      fprintf(STDERR, "%s -> %s: libpng write error\n", inname, outname);
+      png_destroy_read_struct(&read_ptr, &read_info_ptr, &end_info_ptr);
+      png_destroy_info_struct(write_ptr, &write_end_info_ptr);
+#ifdef PNG_WRITE_SUPPORTED
+      png_destroy_write_struct(&write_ptr, &write_info_ptr);
+#endif
+      FCLOSE(fpin);
+      FCLOSE(fpout);
+      return (1);
+   }
+#ifdef USE_FAR_KEYWORD
+   png_memcpy(png_jmpbuf(write_ptr), tmp_jmpbuf, png_sizeof(jmp_buf));
+#endif
+#endif
+#endif
+   pngtest_debug("Initializing input and output streams");
+#ifdef PNG_STDIO_SUPPORTED
+   png_init_io(read_ptr, fpin);
+#  ifdef PNG_WRITE_SUPPORTED
+   png_init_io(write_ptr, fpout);
+#  endif
+#else
+   png_set_read_fn(read_ptr, (png_voidp)fpin, pngtest_read_data);
+#  ifdef PNG_WRITE_SUPPORTED
+   png_set_write_fn(write_ptr, (png_voidp)fpout,  pngtest_write_data,
+#    ifdef PNG_WRITE_FLUSH_SUPPORTED
+      pngtest_flush);
+#    else
+      NULL);
+#    endif
+#  endif
+#endif
+#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
+   /* Normally one would use Z_DEFAULT_STRATEGY for text compression.
+    * This is here just to make pngtest replicate the results from libpng
+    * versions prior to 1.5.4, and to test this new API.
+    */
+   png_set_text_compression_strategy(write_ptr, Z_FILTERED);
+#endif
+   if (status_dots_requested == 1)
+   {
+#ifdef PNG_WRITE_SUPPORTED
+      png_set_write_status_fn(write_ptr, write_row_callback);
+#endif
+      png_set_read_status_fn(read_ptr, read_row_callback);
+   }
+   else
+   {
+#ifdef PNG_WRITE_SUPPORTED
+      png_set_write_status_fn(write_ptr, NULL);
+#endif
+      png_set_read_status_fn(read_ptr, NULL);
+   }
+#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
+   {
+      int i;
+      for (i = 0; i<256; i++)
+         filters_used[i] = 0;
+      png_set_read_user_transform_fn(read_ptr, count_filters);
+   }
+#endif
+#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
+   zero_samples = 0;
+   png_set_write_user_transform_fn(write_ptr, count_zero_samples);
+#endif
+#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+#  ifndef PNG_HANDLE_CHUNK_ALWAYS
+#    define PNG_HANDLE_CHUNK_ALWAYS       3
+#  endif
+   png_set_keep_unknown_chunks(read_ptr, PNG_HANDLE_CHUNK_ALWAYS,
+      NULL, 0);
+#endif
+#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+#  ifndef PNG_HANDLE_CHUNK_IF_SAFE
+#    define PNG_HANDLE_CHUNK_IF_SAFE      2
+#  endif
+   png_set_keep_unknown_chunks(write_ptr, PNG_HANDLE_CHUNK_IF_SAFE,
+      NULL, 0);
+#endif
+   pngtest_debug("Reading info struct");
+   png_read_info(read_ptr, read_info_ptr);
+   pngtest_debug("Transferring info struct");
+   {
+      int interlace_type, compression_type, filter_type;
+      if (png_get_IHDR(read_ptr, read_info_ptr, &width, &height, &bit_depth,
+          &color_type, &interlace_type, &compression_type, &filter_type))
+      {
+         png_set_IHDR(write_ptr, write_info_ptr, width, height, bit_depth,
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+            color_type, interlace_type, compression_type, filter_type);
+#else
+            color_type, PNG_INTERLACE_NONE, compression_type, filter_type);
+#endif
+      }
+   }
+#ifdef PNG_FIXED_POINT_SUPPORTED
+#ifdef PNG_cHRM_SUPPORTED
+   {
+      png_fixed_point white_x, white_y, red_x, red_y, green_x, green_y, blue_x,
+         blue_y;
+      if (png_get_cHRM_fixed(read_ptr, read_info_ptr, &white_x, &white_y,
+         &red_x, &red_y, &green_x, &green_y, &blue_x, &blue_y))
+      {
+         png_set_cHRM_fixed(write_ptr, write_info_ptr, white_x, white_y, red_x,
+            red_y, green_x, green_y, blue_x, blue_y);
+      }
+   }
+#endif
+#ifdef PNG_gAMA_SUPPORTED
+   {
+      png_fixed_point gamma;
+      if (png_get_gAMA_fixed(read_ptr, read_info_ptr, &gamma))
+         png_set_gAMA_fixed(write_ptr, write_info_ptr, gamma);
+   }
+#endif
+#else /* Use floating point versions */
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+#ifdef PNG_cHRM_SUPPORTED
+   {
+      double white_x, white_y, red_x, red_y, green_x, green_y, blue_x,
+         blue_y;
+      if (png_get_cHRM(read_ptr, read_info_ptr, &white_x, &white_y, &red_x,
+         &red_y, &green_x, &green_y, &blue_x, &blue_y))
+      {
+         png_set_cHRM(write_ptr, write_info_ptr, white_x, white_y, red_x,
+            red_y, green_x, green_y, blue_x, blue_y);
+      }
+   }
+#endif
+#ifdef PNG_gAMA_SUPPORTED
+   {
+      double gamma;
+      if (png_get_gAMA(read_ptr, read_info_ptr, &gamma))
+         png_set_gAMA(write_ptr, write_info_ptr, gamma);
+   }
+#endif
+#endif /* Floating point */
+#endif /* Fixed point */
+#ifdef PNG_iCCP_SUPPORTED
+   {
+      png_charp name;
+      png_bytep profile;
+      png_uint_32 proflen;
+      int compression_type;
+      if (png_get_iCCP(read_ptr, read_info_ptr, &name, &compression_type,
+                      &profile, &proflen))
+      {
+         png_set_iCCP(write_ptr, write_info_ptr, name, compression_type,
+                      profile, proflen);
+      }
+   }
+#endif
+#ifdef PNG_sRGB_SUPPORTED
+   {
+      int intent;
+      if (png_get_sRGB(read_ptr, read_info_ptr, &intent))
+         png_set_sRGB(write_ptr, write_info_ptr, intent);
+   }
+#endif
+   {
+      png_colorp palette;
+      int num_palette;
+      if (png_get_PLTE(read_ptr, read_info_ptr, &palette, &num_palette))
+         png_set_PLTE(write_ptr, write_info_ptr, palette, num_palette);
+   }
+#ifdef PNG_bKGD_SUPPORTED
+   {
+      png_color_16p background;
+      if (png_get_bKGD(read_ptr, read_info_ptr, &background))
+      {
+         png_set_bKGD(write_ptr, write_info_ptr, background);
+      }
+   }
+#endif
+#ifdef PNG_hIST_SUPPORTED
+   {
+      png_uint_16p hist;
+      if (png_get_hIST(read_ptr, read_info_ptr, &hist))
+         png_set_hIST(write_ptr, write_info_ptr, hist);
+   }
+#endif
+#ifdef PNG_oFFs_SUPPORTED
+   {
+      png_int_32 offset_x, offset_y;
+      int unit_type;
+      if (png_get_oFFs(read_ptr, read_info_ptr, &offset_x, &offset_y,
+          &unit_type))
+      {
+         png_set_oFFs(write_ptr, write_info_ptr, offset_x, offset_y, unit_type);
+      }
+   }
+#endif
+#ifdef PNG_pCAL_SUPPORTED
+   {
+      png_charp purpose, units;
+      png_charpp params;
+      png_int_32 X0, X1;
+      int type, nparams;
+      if (png_get_pCAL(read_ptr, read_info_ptr, &purpose, &X0, &X1, &type,
+         &nparams, &units, &params))
+      {
+         png_set_pCAL(write_ptr, write_info_ptr, purpose, X0, X1, type,
+            nparams, units, params);
+      }
+   }
+#endif
+#ifdef PNG_pHYs_SUPPORTED
+   {
+      png_uint_32 res_x, res_y;
+      int unit_type;
+      if (png_get_pHYs(read_ptr, read_info_ptr, &res_x, &res_y, &unit_type))
+         png_set_pHYs(write_ptr, write_info_ptr, res_x, res_y, unit_type);
+   }
+#endif
+#ifdef PNG_sBIT_SUPPORTED
+   {
+      png_color_8p sig_bit;
+      if (png_get_sBIT(read_ptr, read_info_ptr, &sig_bit))
+         png_set_sBIT(write_ptr, write_info_ptr, sig_bit);
+   }
+#endif
+#ifdef PNG_sCAL_SUPPORTED
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+   {
+      int unit;
+      double scal_width, scal_height;
+      if (png_get_sCAL(read_ptr, read_info_ptr, &unit, &scal_width,
+         &scal_height))
+      {
+         png_set_sCAL(write_ptr, write_info_ptr, unit, scal_width, scal_height);
+      }
+   }
+#else
+#ifdef PNG_FIXED_POINT_SUPPORTED
+   {
+      int unit;
+      png_charp scal_width, scal_height;
+      if (png_get_sCAL_s(read_ptr, read_info_ptr, &unit, &scal_width,
+          &scal_height))
+      {
+         png_set_sCAL_s(write_ptr, write_info_ptr, unit, scal_width,
+             scal_height);
+      }
+   }
+#endif
+#endif
+#endif
+#ifdef PNG_TEXT_SUPPORTED
+   {
+      png_textp text_ptr;
+      int num_text;
+      if (png_get_text(read_ptr, read_info_ptr, &text_ptr, &num_text) > 0)
+      {
+         pngtest_debug1("Handling %d iTXt/tEXt/zTXt chunks", num_text);
+         if (verbose)
+            printf("\n Text compression=%d\n", text_ptr->compression);
+         png_set_text(write_ptr, write_info_ptr, text_ptr, num_text);
+      }
+   }
+#endif
+#ifdef PNG_tIME_SUPPORTED
+   {
+      png_timep mod_time;
+      if (png_get_tIME(read_ptr, read_info_ptr, &mod_time))
+      {
+         png_set_tIME(write_ptr, write_info_ptr, mod_time);
+#ifdef PNG_TIME_RFC1123_SUPPORTED
+         /* We have to use png_memcpy instead of "=" because the string
+          * pointed to by png_convert_to_rfc1123() gets free'ed before
+          * we use it.
+          */
+         png_memcpy(tIME_string,
+                    png_convert_to_rfc1123(read_ptr, mod_time),
+                    png_sizeof(tIME_string));
+         tIME_string[png_sizeof(tIME_string) - 1] = '\0';
+         tIME_chunk_present++;
+#endif /* PNG_TIME_RFC1123_SUPPORTED */
+      }
+   }
+#endif
+#ifdef PNG_tRNS_SUPPORTED
+   {
+      png_bytep trans_alpha;
+      int num_trans;
+      png_color_16p trans_color;
+      if (png_get_tRNS(read_ptr, read_info_ptr, &trans_alpha, &num_trans,
+         &trans_color))
+      {
+         int sample_max = (1 << bit_depth);
+         /* libpng doesn't reject a tRNS chunk with out-of-range samples */
+         if (!((color_type == PNG_COLOR_TYPE_GRAY &&
+             (int)trans_color->gray > sample_max) ||
+             (color_type == PNG_COLOR_TYPE_RGB &&
+             ((int)trans_color->red > sample_max ||
+             (int)trans_color->green > sample_max ||
+             (int)trans_color->blue > sample_max))))
+            png_set_tRNS(write_ptr, write_info_ptr, trans_alpha, num_trans,
+               trans_color);
+      }
+   }
+#endif
+#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+   {
+      png_unknown_chunkp unknowns;
+      int num_unknowns = png_get_unknown_chunks(read_ptr, read_info_ptr,
+         &unknowns);
+      if (num_unknowns)
+      {
+         int i;
+         png_set_unknown_chunks(write_ptr, write_info_ptr, unknowns,
+           num_unknowns);
+         /* Copy the locations from the read_info_ptr.  The automatically
+          * generated locations in write_info_ptr are wrong because we
+          * haven't written anything yet.
+          */
+         for (i = 0; i < num_unknowns; i++)
+           png_set_unknown_chunk_location(write_ptr, write_info_ptr, i,
+             unknowns[i].location);
+      }
+   }
+#endif
+#ifdef PNG_WRITE_SUPPORTED
+   pngtest_debug("Writing info struct");
+/* If we wanted, we could write info in two steps:
+ * png_write_info_before_PLTE(write_ptr, write_info_ptr);
+ */
+   png_write_info(write_ptr, write_info_ptr);
+#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
+   if (user_chunk_data[0] != 0)
+   {
+      png_byte png_sTER[5] = {115,  84,  69,  82, '\0'};
+      unsigned char
+        ster_chunk_data[1];
+      if (verbose)
+         fprintf(STDERR, "\n stereo mode = %lu\n",
+           (unsigned long)(user_chunk_data[0] - 1));
+      ster_chunk_data[0]=(unsigned char)(user_chunk_data[0] - 1);
+      png_write_chunk(write_ptr, png_sTER, ster_chunk_data, 1);
+   }
+   if (user_chunk_data[1] != 0 || user_chunk_data[2] != 0)
+   {
+      png_byte png_vpAg[5] = {118, 112,  65, 103, '\0'};
+      unsigned char
+        vpag_chunk_data[9];
+      if (verbose)
+         fprintf(STDERR, " vpAg = %lu x %lu, units = %lu\n",
+           (unsigned long)user_chunk_data[1],
+           (unsigned long)user_chunk_data[2],
+           (unsigned long)user_chunk_data[3]);
+      png_save_uint_32(vpag_chunk_data, user_chunk_data[1]);
+      png_save_uint_32(vpag_chunk_data + 4, user_chunk_data[2]);
+      vpag_chunk_data[8] = (unsigned char)(user_chunk_data[3] & 0xff);
+      png_write_chunk(write_ptr, png_vpAg, vpag_chunk_data, 9);
+   }
+#endif
+#endif
+#ifdef SINGLE_ROWBUF_ALLOC
+   pngtest_debug("Allocating row buffer...");
+   row_buf = (png_bytep)png_malloc(read_ptr,
+      png_get_rowbytes(read_ptr, read_info_ptr));
+   pngtest_debug1("\t0x%08lx", (unsigned long)row_buf);
+#endif /* SINGLE_ROWBUF_ALLOC */
+   pngtest_debug("Writing row data");
+#if defined(PNG_READ_INTERLACING_SUPPORTED) || \
+  defined(PNG_WRITE_INTERLACING_SUPPORTED)
+   num_pass = png_set_interlace_handling(read_ptr);
+#  ifdef PNG_WRITE_SUPPORTED
+   png_set_interlace_handling(write_ptr);
+#  endif
+#else
+   num_pass = 1;
+#endif
+#ifdef PNGTEST_TIMING
+   t_stop = (float)clock();
+   t_misc += (t_stop - t_start);
+   t_start = t_stop;
+#endif
+   for (pass = 0; pass < num_pass; pass++)
+   {
+      pngtest_debug1("Writing row data for pass %d", pass);
+      for (y = 0; y < height; y++)
+      {
+#ifndef SINGLE_ROWBUF_ALLOC
+         pngtest_debug2("Allocating row buffer (pass %d, y = %u)...", pass, y);
+         row_buf = (png_bytep)png_malloc(read_ptr,
+            png_get_rowbytes(read_ptr, read_info_ptr));
+         pngtest_debug2("\t0x%08lx (%u bytes)", (unsigned long)row_buf,
+            png_get_rowbytes(read_ptr, read_info_ptr));
+#endif /* !SINGLE_ROWBUF_ALLOC */
+         png_read_rows(read_ptr, (png_bytepp)&row_buf, NULL, 1);
+#ifdef PNG_WRITE_SUPPORTED
+#ifdef PNGTEST_TIMING
+         t_stop = (float)clock();
+         t_decode += (t_stop - t_start);
+         t_start = t_stop;
+#endif
+         png_write_rows(write_ptr, (png_bytepp)&row_buf, 1);
+#ifdef PNGTEST_TIMING
+         t_stop = (float)clock();
+         t_encode += (t_stop - t_start);
+         t_start = t_stop;
+#endif
+#endif /* PNG_WRITE_SUPPORTED */
+#ifndef SINGLE_ROWBUF_ALLOC
+         pngtest_debug2("Freeing row buffer (pass %d, y = %u)", pass, y);
+         png_free(read_ptr, row_buf);
+         row_buf = NULL;
+#endif /* !SINGLE_ROWBUF_ALLOC */
+      }
+   }
+#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+   png_free_data(read_ptr, read_info_ptr, PNG_FREE_UNKN, -1);
+#endif
+#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+   png_free_data(write_ptr, write_info_ptr, PNG_FREE_UNKN, -1);
+#endif
+   pngtest_debug("Reading and writing end_info data");
+   png_read_end(read_ptr, end_info_ptr);
+#ifdef PNG_TEXT_SUPPORTED
+   {
+      png_textp text_ptr;
+      int num_text;
+      if (png_get_text(read_ptr, end_info_ptr, &text_ptr, &num_text) > 0)
+      {
+         pngtest_debug1("Handling %d iTXt/tEXt/zTXt chunks", num_text);
+         png_set_text(write_ptr, write_end_info_ptr, text_ptr, num_text);
+      }
+   }
+#endif
+#ifdef PNG_tIME_SUPPORTED
+   {
+      png_timep mod_time;
+      if (png_get_tIME(read_ptr, end_info_ptr, &mod_time))
+      {
+         png_set_tIME(write_ptr, write_end_info_ptr, mod_time);
+#ifdef PNG_TIME_RFC1123_SUPPORTED
+         /* We have to use png_memcpy instead of "=" because the string
+            pointed to by png_convert_to_rfc1123() gets free'ed before
+            we use it */
+         png_memcpy(tIME_string,
+                    png_convert_to_rfc1123(read_ptr, mod_time),
+                    png_sizeof(tIME_string));
+         tIME_string[png_sizeof(tIME_string) - 1] = '\0';
+         tIME_chunk_present++;
+#endif /* PNG_TIME_RFC1123_SUPPORTED */
+      }
+   }
+#endif
+#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+   {
+      png_unknown_chunkp unknowns;
+      int num_unknowns = png_get_unknown_chunks(read_ptr, end_info_ptr,
+         &unknowns);
+      if (num_unknowns)
+      {
+         int i;
+         png_set_unknown_chunks(write_ptr, write_end_info_ptr, unknowns,
+           num_unknowns);
+         /* Copy the locations from the read_info_ptr.  The automatically
+          * generated locations in write_end_info_ptr are wrong because we
+          * haven't written the end_info yet.
+          */
+         for (i = 0; i < num_unknowns; i++)
+           png_set_unknown_chunk_location(write_ptr, write_end_info_ptr, i,
+             unknowns[i].location);
+      }
+   }
+#endif
+#ifdef PNG_WRITE_SUPPORTED
+   png_write_end(write_ptr, write_end_info_ptr);
+#endif
+#ifdef PNG_EASY_ACCESS_SUPPORTED
+   if (verbose)
+   {
+      png_uint_32 iwidth, iheight;
+      iwidth = png_get_image_width(write_ptr, write_info_ptr);
+      iheight = png_get_image_height(write_ptr, write_info_ptr);
+      fprintf(STDERR, "\n Image width = %lu, height = %lu\n",
+         (unsigned long)iwidth, (unsigned long)iheight);
+   }
+#endif
+   pngtest_debug("Destroying data structs");
+#ifdef SINGLE_ROWBUF_ALLOC
+   pngtest_debug("destroying row_buf for read_ptr");
+   png_free(read_ptr, row_buf);
+   row_buf = NULL;
+#endif /* SINGLE_ROWBUF_ALLOC */
+   pngtest_debug("destroying read_ptr, read_info_ptr, end_info_ptr");
+   png_destroy_read_struct(&read_ptr, &read_info_ptr, &end_info_ptr);
+#ifdef PNG_WRITE_SUPPORTED
+   pngtest_debug("destroying write_end_info_ptr");
+   png_destroy_info_struct(write_ptr, &write_end_info_ptr);
+   pngtest_debug("destroying write_ptr, write_info_ptr");
+   png_destroy_write_struct(&write_ptr, &write_info_ptr);
+#endif
+   pngtest_debug("Destruction complete.");
+   FCLOSE(fpin);
+   FCLOSE(fpout);
+   pngtest_debug("Opening files for comparison");
+   if ((fpin = fopen(inname, "rb")) == NULL)
+   {
+      fprintf(STDERR, "Could not find file %s\n", inname);
+      return (1);
+   }
+   if ((fpout = fopen(outname, "rb")) == NULL)
+   {
+      fprintf(STDERR, "Could not find file %s\n", outname);
+      FCLOSE(fpin);
+      return (1);
+   }
+   for (;;)
+   {
+      png_size_t num_in, num_out;
+         num_in = fread(inbuf, 1, 1, fpin);
+         num_out = fread(outbuf, 1, 1, fpout);
+      if (num_in != num_out)
+      {
+         fprintf(STDERR, "\nFiles %s and %s are of a different size\n",
+                 inname, outname);
+         if (wrote_question == 0)
+         {
+            fprintf(STDERR,
+         "   Was %s written with the same maximum IDAT chunk size (%d bytes),",
+              inname, PNG_ZBUF_SIZE);
+            fprintf(STDERR,
+              "\n   filtering heuristic (libpng default), compression");
+            fprintf(STDERR,
+              " level (zlib default),\n   and zlib version (%s)?\n\n",
+              ZLIB_VERSION);
+            wrote_question = 1;
+         }
+         FCLOSE(fpin);
+         FCLOSE(fpout);
+         if (strict != 0)
+           return (1);
+         else
+           return (0);
+      }
+      if (!num_in)
+         break;
+      if (png_memcmp(inbuf, outbuf, num_in))
+      {
+         fprintf(STDERR, "\nFiles %s and %s are different\n", inname, outname);
+         if (wrote_question == 0)
+         {
+            fprintf(STDERR,
+         "   Was %s written with the same maximum IDAT chunk size (%d bytes),",
+                 inname, PNG_ZBUF_SIZE);
+            fprintf(STDERR,
+              "\n   filtering heuristic (libpng default), compression");
+            fprintf(STDERR,
+              " level (zlib default),\n   and zlib version (%s)?\n\n",
+              ZLIB_VERSION);
+            wrote_question = 1;
+         }
+         FCLOSE(fpin);
+         FCLOSE(fpout);
+         if (strict != 0)
+           return (1);
+         else
+           return (0);
+      }
+   }
+   FCLOSE(fpin);
+   FCLOSE(fpout);
+   return (0);
+}
+/* Input and output filenames */
+#ifdef RISCOS
+static PNG_CONST char *inname = "pngtest/png";
+static PNG_CONST char *outname = "pngout/png";
+#else
+static PNG_CONST char *inname = "pngtest.png";
+static PNG_CONST char *outname = "pngout.png";
+#endif
+int
+main(int argc, char *argv[])
+{
+   int multiple = 0;
+   int ierror = 0;
+   fprintf(STDERR, "\n Testing libpng version %s\n", PNG_LIBPNG_VER_STRING);
+   fprintf(STDERR, "   with zlib   version %s\n", ZLIB_VERSION);
+   fprintf(STDERR, "%s", png_get_copyright(NULL));
+   /* Show the version of libpng used in building the library */
+   fprintf(STDERR, " library (%lu):%s",
+      (unsigned long)png_access_version_number(),
+      png_get_header_version(NULL));
+   /* Show the version of libpng used in building the application */
+   fprintf(STDERR, " pngtest (%lu):%s", (unsigned long)PNG_LIBPNG_VER,
+      PNG_HEADER_VERSION_STRING);
+   /* Do some consistency checking on the memory allocation settings, I'm
+    * not sure this matters, but it is nice to know, the first of these
+    * tests should be impossible because of the way the macros are set
+    * in pngconf.h
+    */
+#if defined(MAXSEG_64K) && !defined(PNG_MAX_MALLOC_64K)
+      fprintf(STDERR, " NOTE: Zlib compiled for max 64k, libpng not\n");
+#endif
+   /* I think the following can happen. */
+#if !defined(MAXSEG_64K) && defined(PNG_MAX_MALLOC_64K)
+      fprintf(STDERR, " NOTE: libpng compiled for max 64k, zlib not\n");
+#endif
+   if (strcmp(png_libpng_ver, PNG_LIBPNG_VER_STRING))
+   {
+      fprintf(STDERR,
+         "Warning: versions are different between png.h and png.c\n");
+      fprintf(STDERR, "  png.h version: %s\n", PNG_LIBPNG_VER_STRING);
+      fprintf(STDERR, "  png.c version: %s\n\n", png_libpng_ver);
+      ++ierror;
+   }
+   if (argc > 1)
+   {
+      if (strcmp(argv[1], "-m") == 0)
+      {
+         multiple = 1;
+         status_dots_requested = 0;
+      }
+      else if (strcmp(argv[1], "-mv") == 0 ||
+               strcmp(argv[1], "-vm") == 0 )
+      {
+         multiple = 1;
+         verbose = 1;
+         status_dots_requested = 1;
+      }
+      else if (strcmp(argv[1], "-v") == 0)
+      {
+         verbose = 1;
+         status_dots_requested = 1;
+         inname = argv[2];
+      }
+      else if (strcmp(argv[1], "--strict") == 0)
+      {
+         status_dots_requested = 0;
+         verbose = 1;
+         inname = argv[2];
+         strict++;
+      }
+      else
+      {
+         inname = argv[1];
+         status_dots_requested = 0;
+      }
+   }
+   if (!multiple && argc == 3 + verbose)
+     outname = argv[2 + verbose];
+   if ((!multiple && argc > 3 + verbose) || (multiple && argc < 2))
+   {
+     fprintf(STDERR,
+       "usage: %s [infile.png] [outfile.png]\n\t%s -m {infile.png}\n",
+        argv[0], argv[0]);
+     fprintf(STDERR,
+       "  reads/writes one PNG file (without -m) or multiple files (-m)\n");
+     fprintf(STDERR,
+       "  with -m %s is used as a temporary file\n", outname);
+     exit(1);
+   }
+   if (multiple)
+   {
+      int i;
+#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
+      int allocation_now = current_allocation;
+#endif
+      for (i=2; i<argc; ++i)
+      {
+         int kerror;
+         fprintf(STDERR, "\n Testing %s:", argv[i]);
+         kerror = test_one_file(argv[i], outname);
+         if (kerror == 0)
+         {
+#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
+            int k;
+#endif
+#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
+            fprintf(STDERR, "\n PASS (%lu zero samples)\n",
+               (unsigned long)zero_samples);
+#else
+            fprintf(STDERR, " PASS\n");
+#endif
+#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
+            for (k = 0; k<256; k++)
+               if (filters_used[k])
+                  fprintf(STDERR, " Filter %d was used %lu times\n",
+                     k, (unsigned long)filters_used[k]);
+#endif
+#ifdef PNG_TIME_RFC1123_SUPPORTED
+         if (tIME_chunk_present != 0)
+            fprintf(STDERR, " tIME = %s\n", tIME_string);
+         tIME_chunk_present = 0;
+#endif /* PNG_TIME_RFC1123_SUPPORTED */
+         }
+         else
+         {
+            fprintf(STDERR, " FAIL\n");
+            ierror += kerror;
+         }
+#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
+         if (allocation_now != current_allocation)
+            fprintf(STDERR, "MEMORY ERROR: %d bytes lost\n",
+               current_allocation - allocation_now);
+         if (current_allocation != 0)
+         {
+            memory_infop pinfo = pinformation;
+            fprintf(STDERR, "MEMORY ERROR: %d bytes still allocated\n",
+               current_allocation);
+            while (pinfo != NULL)
+            {
+               fprintf(STDERR, " %lu bytes at %x\n",
+                 (unsigned long)pinfo->size,
+                 (unsigned int)pinfo->pointer);
+               pinfo = pinfo->next;
+            }
+         }
+#endif
+      }
+#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
+         fprintf(STDERR, " Current memory allocation: %10d bytes\n",
+            current_allocation);
+         fprintf(STDERR, " Maximum memory allocation: %10d bytes\n",
+            maximum_allocation);
+         fprintf(STDERR, " Total   memory allocation: %10d bytes\n",
+            total_allocation);
+         fprintf(STDERR, "     Number of allocations: %10d\n",
+            num_allocations);
+#endif
+   }
+   else
+   {
+      int i;
+      for (i = 0; i<3; ++i)
+      {
+         int kerror;
+#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
+         int allocation_now = current_allocation;
+#endif
+         if (i == 1)
+            status_dots_requested = 1;
+         else if (verbose == 0)
+            status_dots_requested = 0;
+         if (i == 0 || verbose == 1 || ierror != 0)
+            fprintf(STDERR, "\n Testing %s:", inname);
+         kerror = test_one_file(inname, outname);
+         if (kerror == 0)
+         {
+            if (verbose == 1 || i == 2)
+            {
+#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
+                int k;
+#endif
+#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
+                fprintf(STDERR, "\n PASS (%lu zero samples)\n",
+                   (unsigned long)zero_samples);
+#else
+                fprintf(STDERR, " PASS\n");
+#endif
+#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
+                for (k = 0; k<256; k++)
+                   if (filters_used[k])
+                      fprintf(STDERR, " Filter %d was used %lu times\n",
+                         k, (unsigned long)filters_used[k]);
+#endif
+#ifdef PNG_TIME_RFC1123_SUPPORTED
+             if (tIME_chunk_present != 0)
+                fprintf(STDERR, " tIME = %s\n", tIME_string);
+#endif /* PNG_TIME_RFC1123_SUPPORTED */
+            }
+         }
+         else
+         {
+            if (verbose == 0 && i != 2)
+               fprintf(STDERR, "\n Testing %s:", inname);
+            fprintf(STDERR, " FAIL\n");
+            ierror += kerror;
+         }
+#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
+         if (allocation_now != current_allocation)
+             fprintf(STDERR, "MEMORY ERROR: %d bytes lost\n",
+               current_allocation - allocation_now);
+         if (current_allocation != 0)
+         {
+             memory_infop pinfo = pinformation;
+             fprintf(STDERR, "MEMORY ERROR: %d bytes still allocated\n",
+                current_allocation);
+             while (pinfo != NULL)
+             {
+                fprintf(STDERR, " %lu bytes at %x\n",
+                   (unsigned long)pinfo->size, (unsigned int)pinfo->pointer);
+                pinfo = pinfo->next;
+             }
+          }
+#endif
+       }
+#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
+       fprintf(STDERR, " Current memory allocation: %10d bytes\n",
+          current_allocation);
+       fprintf(STDERR, " Maximum memory allocation: %10d bytes\n",
+          maximum_allocation);
+       fprintf(STDERR, " Total   memory allocation: %10d bytes\n",
+          total_allocation);
+       fprintf(STDERR, "     Number of allocations: %10d\n",
+            num_allocations);
+#endif
+   }
+#ifdef PNGTEST_TIMING
+   t_stop = (float)clock();
+   t_misc += (t_stop - t_start);
+   t_start = t_stop;
+   fprintf(STDERR, " CPU time used = %.3f seconds",
+      (t_misc+t_decode+t_encode)/(float)CLOCKS_PER_SEC);
+   fprintf(STDERR, " (decoding %.3f,\n",
+      t_decode/(float)CLOCKS_PER_SEC);
+   fprintf(STDERR, "        encoding %.3f ,",
+      t_encode/(float)CLOCKS_PER_SEC);
+   fprintf(STDERR, " other %.3f seconds)\n\n",
+      t_misc/(float)CLOCKS_PER_SEC);
+#endif
+   if (ierror == 0)
+      fprintf(STDERR, " libpng passes test\n");
+   else
+      fprintf(STDERR, " libpng FAILS test\n");
+   return (int)(ierror != 0);
+}
+/* Generate a compiler error if there is an old png.h in the search path. */
+typedef png_libpng_version_1_5_9 Your_png_h_is_not_version_1_5_9;
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngtest.png b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngtest.png
new file mode 100644
index 0000000..81f5f84
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngtest.png
Binary files differ
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngtrans.c b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngtrans.c
new file mode 100644
index 0000000..53d9a25
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngtrans.c
@@ -0,0 +1,678 @@
+/* pngtrans.c - transforms the data in a row (used by both readers and writers)
+ *
+ * Last changed in libpng 1.5.4 [July 7, 2011]
+ * Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+#include "pngpriv.h"
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
+/* Turn on BGR-to-RGB mapping */
+void PNGAPI
+png_set_bgr(png_structp png_ptr)
+{
+   png_debug(1, "in png_set_bgr");
+   if (png_ptr == NULL)
+      return;
+   png_ptr->transformations |= PNG_BGR;
+}
+#endif
+#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
+/* Turn on 16 bit byte swapping */
+void PNGAPI
+png_set_swap(png_structp png_ptr)
+{
+   png_debug(1, "in png_set_swap");
+   if (png_ptr == NULL)
+      return;
+   if (png_ptr->bit_depth == 16)
+      png_ptr->transformations |= PNG_SWAP_BYTES;
+}
+#endif
+#if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
+/* Turn on pixel packing */
+void PNGAPI
+png_set_packing(png_structp png_ptr)
+{
+   png_debug(1, "in png_set_packing");
+   if (png_ptr == NULL)
+      return;
+   if (png_ptr->bit_depth < 8)
+   {
+      png_ptr->transformations |= PNG_PACK;
+      png_ptr->usr_bit_depth = 8;
+   }
+}
+#endif
+#if defined(PNG_READ_PACKSWAP_SUPPORTED)||defined(PNG_WRITE_PACKSWAP_SUPPORTED)
+/* Turn on packed pixel swapping */
+void PNGAPI
+png_set_packswap(png_structp png_ptr)
+{
+   png_debug(1, "in png_set_packswap");
+   if (png_ptr == NULL)
+      return;
+   if (png_ptr->bit_depth < 8)
+      png_ptr->transformations |= PNG_PACKSWAP;
+}
+#endif
+#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
+void PNGAPI
+png_set_shift(png_structp png_ptr, png_const_color_8p true_bits)
+{
+   png_debug(1, "in png_set_shift");
+   if (png_ptr == NULL)
+      return;
+   png_ptr->transformations |= PNG_SHIFT;
+   png_ptr->shift = *true_bits;
+}
+#endif
+#if defined(PNG_READ_INTERLACING_SUPPORTED) || \
+    defined(PNG_WRITE_INTERLACING_SUPPORTED)
+int PNGAPI
+png_set_interlace_handling(png_structp png_ptr)
+{
+   png_debug(1, "in png_set_interlace handling");
+   if (png_ptr && png_ptr->interlaced)
+   {
+      png_ptr->transformations |= PNG_INTERLACE;
+      return (7);
+   }
+   return (1);
+}
+#endif
+#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
+/* Add a filler byte on read, or remove a filler or alpha byte on write.
+ * The filler type has changed in v0.95 to allow future 2-byte fillers
+ * for 48-bit input data, as well as to avoid problems with some compilers
+ * that don't like bytes as parameters.
+ */
+void PNGAPI
+png_set_filler(png_structp png_ptr, png_uint_32 filler, int filler_loc)
+{
+   png_debug(1, "in png_set_filler");
+   if (png_ptr == NULL)
+      return;
+   png_ptr->transformations |= PNG_FILLER;
+   png_ptr->filler = (png_uint_16)filler;
+   if (filler_loc == PNG_FILLER_AFTER)
+      png_ptr->flags |= PNG_FLAG_FILLER_AFTER;
+   else
+      png_ptr->flags &= ~PNG_FLAG_FILLER_AFTER;
+   /* This should probably go in the "do_read_filler" routine.
+    * I attempted to do that in libpng-1.0.1a but that caused problems
+    * so I restored it in libpng-1.0.2a
+   */
+   if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
+   {
+      png_ptr->usr_channels = 4;
+   }
+   /* Also I added this in libpng-1.0.2a (what happens when we expand
+    * a less-than-8-bit grayscale to GA?) */
+   if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY && png_ptr->bit_depth >= 8)
+   {
+      png_ptr->usr_channels = 2;
+   }
+}
+/* Added to libpng-1.2.7 */
+void PNGAPI
+png_set_add_alpha(png_structp png_ptr, png_uint_32 filler, int filler_loc)
+{
+   png_debug(1, "in png_set_add_alpha");
+   if (png_ptr == NULL)
+      return;
+   png_set_filler(png_ptr, filler, filler_loc);
+   png_ptr->transformations |= PNG_ADD_ALPHA;
+}
+#endif
+#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
+    defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
+void PNGAPI
+png_set_swap_alpha(png_structp png_ptr)
+{
+   png_debug(1, "in png_set_swap_alpha");
+   if (png_ptr == NULL)
+      return;
+   png_ptr->transformations |= PNG_SWAP_ALPHA;
+}
+#endif
+#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
+    defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
+void PNGAPI
+png_set_invert_alpha(png_structp png_ptr)
+{
+   png_debug(1, "in png_set_invert_alpha");
+   if (png_ptr == NULL)
+      return;
+   png_ptr->transformations |= PNG_INVERT_ALPHA;
+}
+#endif
+#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
+void PNGAPI
+png_set_invert_mono(png_structp png_ptr)
+{
+   png_debug(1, "in png_set_invert_mono");
+   if (png_ptr == NULL)
+      return;
+   png_ptr->transformations |= PNG_INVERT_MONO;
+}
+/* Invert monochrome grayscale data */
+void /* PRIVATE */
+png_do_invert(png_row_infop row_info, png_bytep row)
+{
+   png_debug(1, "in png_do_invert");
+  /* This test removed from libpng version 1.0.13 and 1.2.0:
+   *   if (row_info->bit_depth == 1 &&
+   */
+   if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
+   {
+      png_bytep rp = row;
+      png_size_t i;
+      png_size_t istop = row_info->rowbytes;
+      for (i = 0; i < istop; i++)
+      {
+         *rp = (png_byte)(~(*rp));
+         rp++;
+      }
+   }
+   else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA &&
+      row_info->bit_depth == 8)
+   {
+      png_bytep rp = row;
+      png_size_t i;
+      png_size_t istop = row_info->rowbytes;
+      for (i = 0; i < istop; i += 2)
+      {
+         *rp = (png_byte)(~(*rp));
+         rp += 2;
+      }
+   }
+#ifdef PNG_16BIT_SUPPORTED
+   else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA &&
+      row_info->bit_depth == 16)
+   {
+      png_bytep rp = row;
+      png_size_t i;
+      png_size_t istop = row_info->rowbytes;
+      for (i = 0; i < istop; i += 4)
+      {
+         *rp = (png_byte)(~(*rp));
+         *(rp + 1) = (png_byte)(~(*(rp + 1)));
+         rp += 4;
+      }
+   }
+#endif
+}
+#endif
+#ifdef PNG_16BIT_SUPPORTED
+#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
+/* Swaps byte order on 16 bit depth images */
+void /* PRIVATE */
+png_do_swap(png_row_infop row_info, png_bytep row)
+{
+   png_debug(1, "in png_do_swap");
+   if (row_info->bit_depth == 16)
+   {
+      png_bytep rp = row;
+      png_uint_32 i;
+      png_uint_32 istop= row_info->width * row_info->channels;
+      for (i = 0; i < istop; i++, rp += 2)
+      {
+         png_byte t = *rp;
+         *rp = *(rp + 1);
+         *(rp + 1) = t;
+      }
+   }
+}
+#endif
+#endif
+#if defined(PNG_READ_PACKSWAP_SUPPORTED)||defined(PNG_WRITE_PACKSWAP_SUPPORTED)
+static PNG_CONST png_byte onebppswaptable[256] = {
+   0x00, 0x80, 0x40, 0xC0, 0x20, 0xA0, 0x60, 0xE0,
+   0x10, 0x90, 0x50, 0xD0, 0x30, 0xB0, 0x70, 0xF0,
+   0x08, 0x88, 0x48, 0xC8, 0x28, 0xA8, 0x68, 0xE8,
+   0x18, 0x98, 0x58, 0xD8, 0x38, 0xB8, 0x78, 0xF8,
+   0x04, 0x84, 0x44, 0xC4, 0x24, 0xA4, 0x64, 0xE4,
+   0x14, 0x94, 0x54, 0xD4, 0x34, 0xB4, 0x74, 0xF4,
+   0x0C, 0x8C, 0x4C, 0xCC, 0x2C, 0xAC, 0x6C, 0xEC,
+   0x1C, 0x9C, 0x5C, 0xDC, 0x3C, 0xBC, 0x7C, 0xFC,
+   0x02, 0x82, 0x42, 0xC2, 0x22, 0xA2, 0x62, 0xE2,
+   0x12, 0x92, 0x52, 0xD2, 0x32, 0xB2, 0x72, 0xF2,
+   0x0A, 0x8A, 0x4A, 0xCA, 0x2A, 0xAA, 0x6A, 0xEA,
+   0x1A, 0x9A, 0x5A, 0xDA, 0x3A, 0xBA, 0x7A, 0xFA,
+   0x06, 0x86, 0x46, 0xC6, 0x26, 0xA6, 0x66, 0xE6,
+   0x16, 0x96, 0x56, 0xD6, 0x36, 0xB6, 0x76, 0xF6,
+   0x0E, 0x8E, 0x4E, 0xCE, 0x2E, 0xAE, 0x6E, 0xEE,
+   0x1E, 0x9E, 0x5E, 0xDE, 0x3E, 0xBE, 0x7E, 0xFE,
+   0x01, 0x81, 0x41, 0xC1, 0x21, 0xA1, 0x61, 0xE1,
+   0x11, 0x91, 0x51, 0xD1, 0x31, 0xB1, 0x71, 0xF1,
+   0x09, 0x89, 0x49, 0xC9, 0x29, 0xA9, 0x69, 0xE9,
+   0x19, 0x99, 0x59, 0xD9, 0x39, 0xB9, 0x79, 0xF9,
+   0x05, 0x85, 0x45, 0xC5, 0x25, 0xA5, 0x65, 0xE5,
+   0x15, 0x95, 0x55, 0xD5, 0x35, 0xB5, 0x75, 0xF5,
+   0x0D, 0x8D, 0x4D, 0xCD, 0x2D, 0xAD, 0x6D, 0xED,
+   0x1D, 0x9D, 0x5D, 0xDD, 0x3D, 0xBD, 0x7D, 0xFD,
+   0x03, 0x83, 0x43, 0xC3, 0x23, 0xA3, 0x63, 0xE3,
+   0x13, 0x93, 0x53, 0xD3, 0x33, 0xB3, 0x73, 0xF3,
+   0x0B, 0x8B, 0x4B, 0xCB, 0x2B, 0xAB, 0x6B, 0xEB,
+   0x1B, 0x9B, 0x5B, 0xDB, 0x3B, 0xBB, 0x7B, 0xFB,
+   0x07, 0x87, 0x47, 0xC7, 0x27, 0xA7, 0x67, 0xE7,
+   0x17, 0x97, 0x57, 0xD7, 0x37, 0xB7, 0x77, 0xF7,
+   0x0F, 0x8F, 0x4F, 0xCF, 0x2F, 0xAF, 0x6F, 0xEF,
+   0x1F, 0x9F, 0x5F, 0xDF, 0x3F, 0xBF, 0x7F, 0xFF
+};
+static PNG_CONST png_byte twobppswaptable[256] = {
+   0x00, 0x40, 0x80, 0xC0, 0x10, 0x50, 0x90, 0xD0,
+   0x20, 0x60, 0xA0, 0xE0, 0x30, 0x70, 0xB0, 0xF0,
+   0x04, 0x44, 0x84, 0xC4, 0x14, 0x54, 0x94, 0xD4,
+   0x24, 0x64, 0xA4, 0xE4, 0x34, 0x74, 0xB4, 0xF4,
+   0x08, 0x48, 0x88, 0xC8, 0x18, 0x58, 0x98, 0xD8,
+   0x28, 0x68, 0xA8, 0xE8, 0x38, 0x78, 0xB8, 0xF8,
+   0x0C, 0x4C, 0x8C, 0xCC, 0x1C, 0x5C, 0x9C, 0xDC,
+   0x2C, 0x6C, 0xAC, 0xEC, 0x3C, 0x7C, 0xBC, 0xFC,
+   0x01, 0x41, 0x81, 0xC1, 0x11, 0x51, 0x91, 0xD1,
+   0x21, 0x61, 0xA1, 0xE1, 0x31, 0x71, 0xB1, 0xF1,
+   0x05, 0x45, 0x85, 0xC5, 0x15, 0x55, 0x95, 0xD5,
+   0x25, 0x65, 0xA5, 0xE5, 0x35, 0x75, 0xB5, 0xF5,
+   0x09, 0x49, 0x89, 0xC9, 0x19, 0x59, 0x99, 0xD9,
+   0x29, 0x69, 0xA9, 0xE9, 0x39, 0x79, 0xB9, 0xF9,
+   0x0D, 0x4D, 0x8D, 0xCD, 0x1D, 0x5D, 0x9D, 0xDD,
+   0x2D, 0x6D, 0xAD, 0xED, 0x3D, 0x7D, 0xBD, 0xFD,
+   0x02, 0x42, 0x82, 0xC2, 0x12, 0x52, 0x92, 0xD2,
+   0x22, 0x62, 0xA2, 0xE2, 0x32, 0x72, 0xB2, 0xF2,
+   0x06, 0x46, 0x86, 0xC6, 0x16, 0x56, 0x96, 0xD6,
+   0x26, 0x66, 0xA6, 0xE6, 0x36, 0x76, 0xB6, 0xF6,
+   0x0A, 0x4A, 0x8A, 0xCA, 0x1A, 0x5A, 0x9A, 0xDA,
+   0x2A, 0x6A, 0xAA, 0xEA, 0x3A, 0x7A, 0xBA, 0xFA,
+   0x0E, 0x4E, 0x8E, 0xCE, 0x1E, 0x5E, 0x9E, 0xDE,
+   0x2E, 0x6E, 0xAE, 0xEE, 0x3E, 0x7E, 0xBE, 0xFE,
+   0x03, 0x43, 0x83, 0xC3, 0x13, 0x53, 0x93, 0xD3,
+   0x23, 0x63, 0xA3, 0xE3, 0x33, 0x73, 0xB3, 0xF3,
+   0x07, 0x47, 0x87, 0xC7, 0x17, 0x57, 0x97, 0xD7,
+   0x27, 0x67, 0xA7, 0xE7, 0x37, 0x77, 0xB7, 0xF7,
+   0x0B, 0x4B, 0x8B, 0xCB, 0x1B, 0x5B, 0x9B, 0xDB,
+   0x2B, 0x6B, 0xAB, 0xEB, 0x3B, 0x7B, 0xBB, 0xFB,
+   0x0F, 0x4F, 0x8F, 0xCF, 0x1F, 0x5F, 0x9F, 0xDF,
+   0x2F, 0x6F, 0xAF, 0xEF, 0x3F, 0x7F, 0xBF, 0xFF
+};
+static PNG_CONST png_byte fourbppswaptable[256] = {
+   0x00, 0x10, 0x20, 0x30, 0x40, 0x50, 0x60, 0x70,
+   0x80, 0x90, 0xA0, 0xB0, 0xC0, 0xD0, 0xE0, 0xF0,
+   0x01, 0x11, 0x21, 0x31, 0x41, 0x51, 0x61, 0x71,
+   0x81, 0x91, 0xA1, 0xB1, 0xC1, 0xD1, 0xE1, 0xF1,
+   0x02, 0x12, 0x22, 0x32, 0x42, 0x52, 0x62, 0x72,
+   0x82, 0x92, 0xA2, 0xB2, 0xC2, 0xD2, 0xE2, 0xF2,
+   0x03, 0x13, 0x23, 0x33, 0x43, 0x53, 0x63, 0x73,
+   0x83, 0x93, 0xA3, 0xB3, 0xC3, 0xD3, 0xE3, 0xF3,
+   0x04, 0x14, 0x24, 0x34, 0x44, 0x54, 0x64, 0x74,
+   0x84, 0x94, 0xA4, 0xB4, 0xC4, 0xD4, 0xE4, 0xF4,
+   0x05, 0x15, 0x25, 0x35, 0x45, 0x55, 0x65, 0x75,
+   0x85, 0x95, 0xA5, 0xB5, 0xC5, 0xD5, 0xE5, 0xF5,
+   0x06, 0x16, 0x26, 0x36, 0x46, 0x56, 0x66, 0x76,
+   0x86, 0x96, 0xA6, 0xB6, 0xC6, 0xD6, 0xE6, 0xF6,
+   0x07, 0x17, 0x27, 0x37, 0x47, 0x57, 0x67, 0x77,
+   0x87, 0x97, 0xA7, 0xB7, 0xC7, 0xD7, 0xE7, 0xF7,
+   0x08, 0x18, 0x28, 0x38, 0x48, 0x58, 0x68, 0x78,
+   0x88, 0x98, 0xA8, 0xB8, 0xC8, 0xD8, 0xE8, 0xF8,
+   0x09, 0x19, 0x29, 0x39, 0x49, 0x59, 0x69, 0x79,
+   0x89, 0x99, 0xA9, 0xB9, 0xC9, 0xD9, 0xE9, 0xF9,
+   0x0A, 0x1A, 0x2A, 0x3A, 0x4A, 0x5A, 0x6A, 0x7A,
+   0x8A, 0x9A, 0xAA, 0xBA, 0xCA, 0xDA, 0xEA, 0xFA,
+   0x0B, 0x1B, 0x2B, 0x3B, 0x4B, 0x5B, 0x6B, 0x7B,
+   0x8B, 0x9B, 0xAB, 0xBB, 0xCB, 0xDB, 0xEB, 0xFB,
+   0x0C, 0x1C, 0x2C, 0x3C, 0x4C, 0x5C, 0x6C, 0x7C,
+   0x8C, 0x9C, 0xAC, 0xBC, 0xCC, 0xDC, 0xEC, 0xFC,
+   0x0D, 0x1D, 0x2D, 0x3D, 0x4D, 0x5D, 0x6D, 0x7D,
+   0x8D, 0x9D, 0xAD, 0xBD, 0xCD, 0xDD, 0xED, 0xFD,
+   0x0E, 0x1E, 0x2E, 0x3E, 0x4E, 0x5E, 0x6E, 0x7E,
+   0x8E, 0x9E, 0xAE, 0xBE, 0xCE, 0xDE, 0xEE, 0xFE,
+   0x0F, 0x1F, 0x2F, 0x3F, 0x4F, 0x5F, 0x6F, 0x7F,
+   0x8F, 0x9F, 0xAF, 0xBF, 0xCF, 0xDF, 0xEF, 0xFF
+};
+/* Swaps pixel packing order within bytes */
+void /* PRIVATE */
+png_do_packswap(png_row_infop row_info, png_bytep row)
+{
+   png_debug(1, "in png_do_packswap");
+   if (row_info->bit_depth < 8)
+   {
+      png_bytep rp;
+      png_const_bytep end, table;
+      end = row + row_info->rowbytes;
+      if (row_info->bit_depth == 1)
+         table = onebppswaptable;
+      else if (row_info->bit_depth == 2)
+         table = twobppswaptable;
+      else if (row_info->bit_depth == 4)
+         table = fourbppswaptable;
+      else
+         return;
+      for (rp = row; rp < end; rp++)
+         *rp = table[*rp];
+   }
+}
+#endif /* PNG_READ_PACKSWAP_SUPPORTED or PNG_WRITE_PACKSWAP_SUPPORTED */
+#if defined(PNG_WRITE_FILLER_SUPPORTED) || \
+    defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
+/* Remove a channel - this used to be 'png_do_strip_filler' but it used a
+ * somewhat weird combination of flags to determine what to do.  All the calls
+ * to png_do_strip_filler are changed in 1.5.2 to call this instead with the
+ * correct arguments.
+ *
+ * The routine isn't general - the channel must be the channel at the start or
+ * end (not in the middle) of each pixel.
+ */
+void /* PRIVATE */
+png_do_strip_channel(png_row_infop row_info, png_bytep row, int at_start)
+{
+   png_bytep sp = row; /* source pointer */
+   png_bytep dp = row; /* destination pointer */
+   png_bytep ep = row + row_info->rowbytes; /* One beyond end of row */
+   /* At the start sp will point to the first byte to copy and dp to where
+    * it is copied to.  ep always points just beyond the end of the row, so
+    * the loop simply copies (channels-1) channels until sp reaches ep.
+    *
+    * at_start:        0 -- convert AG, XG, ARGB, XRGB, AAGG, XXGG, etc.
+    *            nonzero -- convert GA, GX, RGBA, RGBX, GGAA, RRGGBBXX, etc.
+    */
+   /* GA, GX, XG cases */
+   if (row_info->channels == 2)
+   {
+      if (row_info->bit_depth == 8)
+      {
+         if (at_start) /* Skip initial filler */
+            ++sp;
+         else          /* Skip initial channel and, for sp, the filler */
+            sp += 2, ++dp;
+         /* For a 1 pixel wide image there is nothing to do */
+         while (sp < ep)
+            *dp++ = *sp, sp += 2;
+         row_info->pixel_depth = 8;
+      }
+      else if (row_info->bit_depth == 16)
+      {
+         if (at_start) /* Skip initial filler */
+            sp += 2;
+         else          /* Skip initial channel and, for sp, the filler */
+            sp += 4, dp += 2;
+         while (sp < ep)
+            *dp++ = *sp++, *dp++ = *sp, sp += 3;
+         row_info->pixel_depth = 16;
+      }
+      else
+         return; /* bad bit depth */
+      row_info->channels = 1;
+      /* Finally fix the color type if it records an alpha channel */
+      if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+         row_info->color_type = PNG_COLOR_TYPE_GRAY;
+   }
+   /* RGBA, RGBX, XRGB cases */
+   else if (row_info->channels == 4)
+   {
+      if (row_info->bit_depth == 8)
+      {
+         if (at_start) /* Skip initial filler */
+            ++sp;
+         else          /* Skip initial channels and, for sp, the filler */
+            sp += 4, dp += 3;
+         /* Note that the loop adds 3 to dp and 4 to sp each time. */
+         while (sp < ep)
+            *dp++ = *sp++, *dp++ = *sp++, *dp++ = *sp, sp += 2;
+         row_info->pixel_depth = 24;
+      }
+      else if (row_info->bit_depth == 16)
+      {
+         if (at_start) /* Skip initial filler */
+            sp += 2;
+         else          /* Skip initial channels and, for sp, the filler */
+            sp += 8, dp += 6;
+         while (sp < ep)
+         {
+            /* Copy 6 bytes, skip 2 */
+            *dp++ = *sp++, *dp++ = *sp++;
+            *dp++ = *sp++, *dp++ = *sp++;
+            *dp++ = *sp++, *dp++ = *sp, sp += 3;
+         }
+         row_info->pixel_depth = 48;
+      }
+      else
+         return; /* bad bit depth */
+      row_info->channels = 3;
+      /* Finally fix the color type if it records an alpha channel */
+      if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+         row_info->color_type = PNG_COLOR_TYPE_RGB;
+   }
+   else
+      return; /* The filler channel has gone already */
+   /* Fix the rowbytes value. */
+   row_info->rowbytes = dp-row;
+}
+#endif
+#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
+/* Swaps red and blue bytes within a pixel */
+void /* PRIVATE */
+png_do_bgr(png_row_infop row_info, png_bytep row)
+{
+   png_debug(1, "in png_do_bgr");
+   if ((row_info->color_type & PNG_COLOR_MASK_COLOR))
+   {
+      png_uint_32 row_width = row_info->width;
+      if (row_info->bit_depth == 8)
+      {
+         if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+         {
+            png_bytep rp;
+            png_uint_32 i;
+            for (i = 0, rp = row; i < row_width; i++, rp += 3)
+            {
+               png_byte save = *rp;
+               *rp = *(rp + 2);
+               *(rp + 2) = save;
+            }
+         }
+         else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+         {
+            png_bytep rp;
+            png_uint_32 i;
+            for (i = 0, rp = row; i < row_width; i++, rp += 4)
+            {
+               png_byte save = *rp;
+               *rp = *(rp + 2);
+               *(rp + 2) = save;
+            }
+         }
+      }
+#ifdef PNG_16BIT_SUPPORTED
+      else if (row_info->bit_depth == 16)
+      {
+         if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+         {
+            png_bytep rp;
+            png_uint_32 i;
+            for (i = 0, rp = row; i < row_width; i++, rp += 6)
+            {
+               png_byte save = *rp;
+               *rp = *(rp + 4);
+               *(rp + 4) = save;
+               save = *(rp + 1);
+               *(rp + 1) = *(rp + 5);
+               *(rp + 5) = save;
+            }
+         }
+         else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+         {
+            png_bytep rp;
+            png_uint_32 i;
+            for (i = 0, rp = row; i < row_width; i++, rp += 8)
+            {
+               png_byte save = *rp;
+               *rp = *(rp + 4);
+               *(rp + 4) = save;
+               save = *(rp + 1);
+               *(rp + 1) = *(rp + 5);
+               *(rp + 5) = save;
+            }
+         }
+      }
+#endif
+   }
+}
+#endif /* PNG_READ_BGR_SUPPORTED or PNG_WRITE_BGR_SUPPORTED */
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
+    defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
+#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
+void PNGAPI
+png_set_user_transform_info(png_structp png_ptr, png_voidp
+   user_transform_ptr, int user_transform_depth, int user_transform_channels)
+{
+   png_debug(1, "in png_set_user_transform_info");
+   if (png_ptr == NULL)
+      return;
+   png_ptr->user_transform_ptr = user_transform_ptr;
+   png_ptr->user_transform_depth = (png_byte)user_transform_depth;
+   png_ptr->user_transform_channels = (png_byte)user_transform_channels;
+}
+#endif
+/* This function returns a pointer to the user_transform_ptr associated with
+ * the user transform functions.  The application should free any memory
+ * associated with this pointer before png_write_destroy and png_read_destroy
+ * are called.
+ */
+#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
+png_voidp PNGAPI
+png_get_user_transform_ptr(png_const_structp png_ptr)
+{
+   if (png_ptr == NULL)
+      return (NULL);
+   return ((png_voidp)png_ptr->user_transform_ptr);
+}
+#endif
+#ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED
+png_uint_32 PNGAPI
+png_get_current_row_number(png_const_structp png_ptr)
+{
+   /* See the comments in png.h - this is the sub-image row when reading and
+    * interlaced image.
+    */
+   if (png_ptr != NULL)
+      return png_ptr->row_number;
+   return PNG_UINT_32_MAX; /* help the app not to fail silently */
+}
+png_byte PNGAPI
+png_get_current_pass_number(png_const_structp png_ptr)
+{
+   if (png_ptr != NULL)
+      return png_ptr->pass;
+   return 8; /* invalid */
+}
+#endif /* PNG_USER_TRANSFORM_INFO_SUPPORTED */
+#endif /* PNG_READ_USER_TRANSFORM_SUPPORTED ||
+          PNG_WRITE_USER_TRANSFORM_SUPPORTED */
+#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngwio.c b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngwio.c
new file mode 100644
index 0000000..8eacf9f
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngwio.c
@@ -0,0 +1,254 @@
+/* pngwio.c - functions for data output
+ *
+ * Last changed in libpng 1.5.0 [January 6, 2011]
+ * Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * This file provides a location for all output.  Users who need
+ * special handling are expected to write functions that have the same
+ * arguments as these and perform similar functions, but that possibly
+ * use different output methods.  Note that you shouldn't change these
+ * functions, but rather write replacement functions and then change
+ * them at run time with png_set_write_fn(...).
+ */
+#include "pngpriv.h"
+#ifdef PNG_WRITE_SUPPORTED
+/* Write the data to whatever output you are using.  The default routine
+ * writes to a file pointer.  Note that this routine sometimes gets called
+ * with very small lengths, so you should implement some kind of simple
+ * buffering if you are using unbuffered writes.  This should never be asked
+ * to write more than 64K on a 16 bit machine.
+ */
+void /* PRIVATE */
+png_write_data(png_structp png_ptr, png_const_bytep data, png_size_t length)
+{
+   /* NOTE: write_data_fn must not change the buffer! */
+   if (png_ptr->write_data_fn != NULL )
+      (*(png_ptr->write_data_fn))(png_ptr, (png_bytep)data, length);
+   else
+      png_error(png_ptr, "Call to NULL write function");
+}
+#ifdef PNG_STDIO_SUPPORTED
+/* This is the function that does the actual writing of data.  If you are
+ * not writing to a standard C stream, you should create a replacement
+ * write_data function and use it at run time with png_set_write_fn(), rather
+ * than changing the library.
+ */
+#ifndef USE_FAR_KEYWORD
+void PNGCBAPI
+png_default_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
+{
+   png_size_t check;
+   if (png_ptr == NULL)
+      return;
+   check = fwrite(data, 1, length, (png_FILE_p)(png_ptr->io_ptr));
+   if (check != length)
+      png_error(png_ptr, "Write Error");
+}
+#else
+/* This is the model-independent version. Since the standard I/O library
+ * can't handle far buffers in the medium and small models, we have to copy
+ * the data.
+ */
+#define NEAR_BUF_SIZE 1024
+#define MIN(a,b) (a <= b ? a : b)
+void PNGCBAPI
+png_default_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
+{
+   png_uint_32 check;
+   png_byte *near_data;  /* Needs to be "png_byte *" instead of "png_bytep" */
+   png_FILE_p io_ptr;
+   if (png_ptr == NULL)
+      return;
+   /* Check if data really is near. If so, use usual code. */
+   near_data = (png_byte *)CVT_PTR_NOCHECK(data);
+   io_ptr = (png_FILE_p)CVT_PTR(png_ptr->io_ptr);
+   if ((png_bytep)near_data == data)
+   {
+      check = fwrite(near_data, 1, length, io_ptr);
+   }
+   else
+   {
+      png_byte buf[NEAR_BUF_SIZE];
+      png_size_t written, remaining, err;
+      check = 0;
+      remaining = length;
+      do
+      {
+         written = MIN(NEAR_BUF_SIZE, remaining);
+         png_memcpy(buf, data, written); /* Copy far buffer to near buffer */
+         err = fwrite(buf, 1, written, io_ptr);
+         if (err != written)
+            break;
+         else
+            check += err;
+         data += written;
+         remaining -= written;
+      }
+      while (remaining != 0);
+   }
+   if (check != length)
+      png_error(png_ptr, "Write Error");
+}
+#endif
+#endif
+/* This function is called to output any data pending writing (normally
+ * to disk).  After png_flush is called, there should be no data pending
+ * writing in any buffers.
+ */
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+void /* PRIVATE */
+png_flush(png_structp png_ptr)
+{
+   if (png_ptr->output_flush_fn != NULL)
+      (*(png_ptr->output_flush_fn))(png_ptr);
+}
+#  ifdef PNG_STDIO_SUPPORTED
+void PNGCBAPI
+png_default_flush(png_structp png_ptr)
+{
+   png_FILE_p io_ptr;
+   if (png_ptr == NULL)
+      return;
+   io_ptr = (png_FILE_p)CVT_PTR((png_ptr->io_ptr));
+   fflush(io_ptr);
+}
+#  endif
+#endif
+/* This function allows the application to supply new output functions for
+ * libpng if standard C streams aren't being used.
+ *
+ * This function takes as its arguments:
+ * png_ptr       - pointer to a png output data structure
+ * io_ptr        - pointer to user supplied structure containing info about
+ *                 the output functions.  May be NULL.
+ * write_data_fn - pointer to a new output function that takes as its
+ *                 arguments a pointer to a png_struct, a pointer to
+ *                 data to be written, and a 32-bit unsigned int that is
+ *                 the number of bytes to be written.  The new write
+ *                 function should call png_error(png_ptr, "Error msg")
+ *                 to exit and output any fatal error messages.  May be
+ *                 NULL, in which case libpng's default function will
+ *                 be used.
+ * flush_data_fn - pointer to a new flush function that takes as its
+ *                 arguments a pointer to a png_struct.  After a call to
+ *                 the flush function, there should be no data in any buffers
+ *                 or pending transmission.  If the output method doesn't do
+ *                 any buffering of output, a function prototype must still be
+ *                 supplied although it doesn't have to do anything.  If
+ *                 PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile
+ *                 time, output_flush_fn will be ignored, although it must be
+ *                 supplied for compatibility.  May be NULL, in which case
+ *                 libpng's default function will be used, if
+ *                 PNG_WRITE_FLUSH_SUPPORTED is defined.  This is not
+ *                 a good idea if io_ptr does not point to a standard
+ *                 *FILE structure.
+ */
+void PNGAPI
+png_set_write_fn(png_structp png_ptr, png_voidp io_ptr,
+    png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn)
+{
+   if (png_ptr == NULL)
+      return;
+   png_ptr->io_ptr = io_ptr;
+#ifdef PNG_STDIO_SUPPORTED
+   if (write_data_fn != NULL)
+      png_ptr->write_data_fn = write_data_fn;
+   else
+      png_ptr->write_data_fn = png_default_write_data;
+#else
+   png_ptr->write_data_fn = write_data_fn;
+#endif
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+#  ifdef PNG_STDIO_SUPPORTED
+   if (output_flush_fn != NULL)
+      png_ptr->output_flush_fn = output_flush_fn;
+   else
+      png_ptr->output_flush_fn = png_default_flush;
+#  else
+   png_ptr->output_flush_fn = output_flush_fn;
+#  endif
+#endif /* PNG_WRITE_FLUSH_SUPPORTED */
+   /* It is an error to read while writing a png file */
+   if (png_ptr->read_data_fn != NULL)
+   {
+      png_ptr->read_data_fn = NULL;
+      png_warning(png_ptr,
+          "Can't set both read_data_fn and write_data_fn in the"
+          " same structure");
+   }
+}
+#ifdef USE_FAR_KEYWORD
+#  ifdef _MSC_VER
+void *png_far_to_near(png_structp png_ptr, png_voidp ptr, int check)
+{
+   void *near_ptr;
+   void FAR *far_ptr;
+   FP_OFF(near_ptr) = FP_OFF(ptr);
+   far_ptr = (void FAR *)near_ptr;
+   if (check != 0)
+      if (FP_SEG(ptr) != FP_SEG(far_ptr))
+         png_error(png_ptr, "segment lost in conversion");
+   return(near_ptr);
+}
+#  else
+void *png_far_to_near(png_structp png_ptr, png_voidp ptr, int check)
+{
+   void *near_ptr;
+   void FAR *far_ptr;
+   near_ptr = (void FAR *)ptr;
+   far_ptr = (void FAR *)near_ptr;
+   if (check != 0)
+      if (far_ptr != ptr)
+         png_error(png_ptr, "segment lost in conversion");
+   return(near_ptr);
+}
+#  endif
+#endif
+#endif /* PNG_WRITE_SUPPORTED */
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngwrite.c b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngwrite.c
new file mode 100644
index 0000000..dc12a20
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngwrite.c
@@ -0,0 +1,1655 @@
+/* pngwrite.c - general routines to write a PNG file
+ *
+ * Last changed in libpng 1.5.7 [December 15, 2011]
+ * Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+#include "pngpriv.h"
+#ifdef PNG_WRITE_SUPPORTED
+/* Writes all the PNG information.  This is the suggested way to use the
+ * library.  If you have a new chunk to add, make a function to write it,
+ * and put it in the correct location here.  If you want the chunk written
+ * after the image data, put it in png_write_end().  I strongly encourage
+ * you to supply a PNG_INFO_ flag, and check info_ptr->valid before writing
+ * the chunk, as that will keep the code from breaking if you want to just
+ * write a plain PNG file.  If you have long comments, I suggest writing
+ * them in png_write_end(), and compressing them.
+ */
+void PNGAPI
+png_write_info_before_PLTE(png_structp png_ptr, png_infop info_ptr)
+{
+   png_debug(1, "in png_write_info_before_PLTE");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+   if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE))
+   {
+   /* Write PNG signature */
+   png_write_sig(png_ptr);
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+   if ((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE) && \
+       (png_ptr->mng_features_permitted))
+   {
+      png_warning(png_ptr, "MNG features are not allowed in a PNG datastream");
+      png_ptr->mng_features_permitted = 0;
+   }
+#endif
+   /* Write IHDR information. */
+   png_write_IHDR(png_ptr, info_ptr->width, info_ptr->height,
+       info_ptr->bit_depth, info_ptr->color_type, info_ptr->compression_type,
+       info_ptr->filter_type,
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+       info_ptr->interlace_type);
+#else
+       0);
+#endif
+   /* The rest of these check to see if the valid field has the appropriate
+    * flag set, and if it does, writes the chunk.
+    */
+#ifdef PNG_WRITE_gAMA_SUPPORTED
+   if (info_ptr->valid & PNG_INFO_gAMA)
+      png_write_gAMA_fixed(png_ptr, info_ptr->gamma);
+#endif
+#ifdef PNG_WRITE_sRGB_SUPPORTED
+   if (info_ptr->valid & PNG_INFO_sRGB)
+      png_write_sRGB(png_ptr, (int)info_ptr->srgb_intent);
+#endif
+#ifdef PNG_WRITE_iCCP_SUPPORTED
+   if (info_ptr->valid & PNG_INFO_iCCP)
+      png_write_iCCP(png_ptr, info_ptr->iccp_name, PNG_COMPRESSION_TYPE_BASE,
+          (png_charp)info_ptr->iccp_profile, (int)info_ptr->iccp_proflen);
+#endif
+#ifdef PNG_WRITE_sBIT_SUPPORTED
+   if (info_ptr->valid & PNG_INFO_sBIT)
+      png_write_sBIT(png_ptr, &(info_ptr->sig_bit), info_ptr->color_type);
+#endif
+#ifdef PNG_WRITE_cHRM_SUPPORTED
+   if (info_ptr->valid & PNG_INFO_cHRM)
+      png_write_cHRM_fixed(png_ptr,
+          info_ptr->x_white, info_ptr->y_white,
+          info_ptr->x_red, info_ptr->y_red,
+          info_ptr->x_green, info_ptr->y_green,
+          info_ptr->x_blue, info_ptr->y_blue);
+#endif
+#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+   if (info_ptr->unknown_chunks_num)
+   {
+      png_unknown_chunk *up;
+      png_debug(5, "writing extra chunks");
+      for (up = info_ptr->unknown_chunks;
+           up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
+           up++)
+      {
+         int keep = png_handle_as_unknown(png_ptr, up->name);
+         if (keep != PNG_HANDLE_CHUNK_NEVER &&
+             up->location &&
+             !(up->location & PNG_HAVE_PLTE) &&
+             !(up->location & PNG_HAVE_IDAT) &&
+             !(up->location & PNG_AFTER_IDAT) &&
+             ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
+             (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
+         {
+            if (up->size == 0)
+               png_warning(png_ptr, "Writing zero-length unknown chunk");
+            png_write_chunk(png_ptr, up->name, up->data, up->size);
+         }
+      }
+   }
+#endif
+      png_ptr->mode |= PNG_WROTE_INFO_BEFORE_PLTE;
+   }
+}
+void PNGAPI
+png_write_info(png_structp png_ptr, png_infop info_ptr)
+{
+#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
+   int i;
+#endif
+   png_debug(1, "in png_write_info");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+   png_write_info_before_PLTE(png_ptr, info_ptr);
+   if (info_ptr->valid & PNG_INFO_PLTE)
+      png_write_PLTE(png_ptr, info_ptr->palette,
+          (png_uint_32)info_ptr->num_palette);
+   else if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+      png_error(png_ptr, "Valid palette required for paletted images");
+#ifdef PNG_WRITE_tRNS_SUPPORTED
+   if (info_ptr->valid & PNG_INFO_tRNS)
+   {
+#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
+      /* Invert the alpha channel (in tRNS) */
+      if ((png_ptr->transformations & PNG_INVERT_ALPHA) &&
+          info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+      {
+         int j;
+         for (j = 0; j<(int)info_ptr->num_trans; j++)
+            info_ptr->trans_alpha[j] =
+               (png_byte)(255 - info_ptr->trans_alpha[j]);
+      }
+#endif
+      png_write_tRNS(png_ptr, info_ptr->trans_alpha, &(info_ptr->trans_color),
+          info_ptr->num_trans, info_ptr->color_type);
+   }
+#endif
+#ifdef PNG_WRITE_bKGD_SUPPORTED
+   if (info_ptr->valid & PNG_INFO_bKGD)
+      png_write_bKGD(png_ptr, &(info_ptr->background), info_ptr->color_type);
+#endif
+#ifdef PNG_WRITE_hIST_SUPPORTED
+   if (info_ptr->valid & PNG_INFO_hIST)
+      png_write_hIST(png_ptr, info_ptr->hist, info_ptr->num_palette);
+#endif
+#ifdef PNG_WRITE_oFFs_SUPPORTED
+   if (info_ptr->valid & PNG_INFO_oFFs)
+      png_write_oFFs(png_ptr, info_ptr->x_offset, info_ptr->y_offset,
+          info_ptr->offset_unit_type);
+#endif
+#ifdef PNG_WRITE_pCAL_SUPPORTED
+   if (info_ptr->valid & PNG_INFO_pCAL)
+      png_write_pCAL(png_ptr, info_ptr->pcal_purpose, info_ptr->pcal_X0,
+          info_ptr->pcal_X1, info_ptr->pcal_type, info_ptr->pcal_nparams,
+          info_ptr->pcal_units, info_ptr->pcal_params);
+#endif
+#ifdef PNG_WRITE_sCAL_SUPPORTED
+   if (info_ptr->valid & PNG_INFO_sCAL)
+      png_write_sCAL_s(png_ptr, (int)info_ptr->scal_unit,
+          info_ptr->scal_s_width, info_ptr->scal_s_height);
+#endif /* sCAL */
+#ifdef PNG_WRITE_pHYs_SUPPORTED
+   if (info_ptr->valid & PNG_INFO_pHYs)
+      png_write_pHYs(png_ptr, info_ptr->x_pixels_per_unit,
+          info_ptr->y_pixels_per_unit, info_ptr->phys_unit_type);
+#endif /* pHYs */
+#ifdef PNG_WRITE_tIME_SUPPORTED
+   if (info_ptr->valid & PNG_INFO_tIME)
+   {
+      png_write_tIME(png_ptr, &(info_ptr->mod_time));
+      png_ptr->mode |= PNG_WROTE_tIME;
+   }
+#endif /* tIME */
+#ifdef PNG_WRITE_sPLT_SUPPORTED
+   if (info_ptr->valid & PNG_INFO_sPLT)
+      for (i = 0; i < (int)info_ptr->splt_palettes_num; i++)
+         png_write_sPLT(png_ptr, info_ptr->splt_palettes + i);
+#endif /* sPLT */
+#ifdef PNG_WRITE_TEXT_SUPPORTED
+   /* Check to see if we need to write text chunks */
+   for (i = 0; i < info_ptr->num_text; i++)
+   {
+      png_debug2(2, "Writing header text chunk %d, type %d", i,
+          info_ptr->text[i].compression);
+      /* An internationalized chunk? */
+      if (info_ptr->text[i].compression > 0)
+      {
+#ifdef PNG_WRITE_iTXt_SUPPORTED
+         /* Write international chunk */
+         png_write_iTXt(png_ptr,
+             info_ptr->text[i].compression,
+             info_ptr->text[i].key,
+             info_ptr->text[i].lang,
+             info_ptr->text[i].lang_key,
+             info_ptr->text[i].text);
+#else
+          png_warning(png_ptr, "Unable to write international text");
+#endif
+          /* Mark this chunk as written */
+          info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
+      }
+      /* If we want a compressed text chunk */
+      else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_zTXt)
+      {
+#ifdef PNG_WRITE_zTXt_SUPPORTED
+         /* Write compressed chunk */
+         png_write_zTXt(png_ptr, info_ptr->text[i].key,
+             info_ptr->text[i].text, 0,
+             info_ptr->text[i].compression);
+#else
+         png_warning(png_ptr, "Unable to write compressed text");
+#endif
+         /* Mark this chunk as written */
+         info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
+      }
+      else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
+      {
+#ifdef PNG_WRITE_tEXt_SUPPORTED
+         /* Write uncompressed chunk */
+         png_write_tEXt(png_ptr, info_ptr->text[i].key,
+             info_ptr->text[i].text,
+             0);
+         /* Mark this chunk as written */
+         info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
+#else
+         /* Can't get here */
+         png_warning(png_ptr, "Unable to write uncompressed text");
+#endif
+      }
+   }
+#endif /* tEXt */
+#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+   if (info_ptr->unknown_chunks_num)
+   {
+      png_unknown_chunk *up;
+      png_debug(5, "writing extra chunks");
+      for (up = info_ptr->unknown_chunks;
+           up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
+           up++)
+      {
+         int keep = png_handle_as_unknown(png_ptr, up->name);
+         if (keep != PNG_HANDLE_CHUNK_NEVER &&
+             up->location &&
+             (up->location & PNG_HAVE_PLTE) &&
+             !(up->location & PNG_HAVE_IDAT) &&
+             !(up->location & PNG_AFTER_IDAT) &&
+             ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
+             (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
+         {
+            png_write_chunk(png_ptr, up->name, up->data, up->size);
+         }
+      }
+   }
+#endif
+}
+/* Writes the end of the PNG file.  If you don't want to write comments or
+ * time information, you can pass NULL for info.  If you already wrote these
+ * in png_write_info(), do not write them again here.  If you have long
+ * comments, I suggest writing them here, and compressing them.
+ */
+void PNGAPI
+png_write_end(png_structp png_ptr, png_infop info_ptr)
+{
+   png_debug(1, "in png_write_end");
+   if (png_ptr == NULL)
+      return;
+   if (!(png_ptr->mode & PNG_HAVE_IDAT))
+      png_error(png_ptr, "No IDATs written into file");
+   /* See if user wants us to write information chunks */
+   if (info_ptr != NULL)
+   {
+#ifdef PNG_WRITE_TEXT_SUPPORTED
+      int i; /* local index variable */
+#endif
+#ifdef PNG_WRITE_tIME_SUPPORTED
+      /* Check to see if user has supplied a time chunk */
+      if ((info_ptr->valid & PNG_INFO_tIME) &&
+          !(png_ptr->mode & PNG_WROTE_tIME))
+         png_write_tIME(png_ptr, &(info_ptr->mod_time));
+#endif
+#ifdef PNG_WRITE_TEXT_SUPPORTED
+      /* Loop through comment chunks */
+      for (i = 0; i < info_ptr->num_text; i++)
+      {
+         png_debug2(2, "Writing trailer text chunk %d, type %d", i,
+            info_ptr->text[i].compression);
+         /* An internationalized chunk? */
+         if (info_ptr->text[i].compression > 0)
+         {
+#ifdef PNG_WRITE_iTXt_SUPPORTED
+            /* Write international chunk */
+            png_write_iTXt(png_ptr,
+                info_ptr->text[i].compression,
+                info_ptr->text[i].key,
+                info_ptr->text[i].lang,
+                info_ptr->text[i].lang_key,
+                info_ptr->text[i].text);
+#else
+            png_warning(png_ptr, "Unable to write international text");
+#endif
+            /* Mark this chunk as written */
+            info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
+         }
+         else if (info_ptr->text[i].compression >= PNG_TEXT_COMPRESSION_zTXt)
+         {
+#ifdef PNG_WRITE_zTXt_SUPPORTED
+            /* Write compressed chunk */
+            png_write_zTXt(png_ptr, info_ptr->text[i].key,
+                info_ptr->text[i].text, 0,
+                info_ptr->text[i].compression);
+#else
+            png_warning(png_ptr, "Unable to write compressed text");
+#endif
+            /* Mark this chunk as written */
+            info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
+         }
+         else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
+         {
+#ifdef PNG_WRITE_tEXt_SUPPORTED
+            /* Write uncompressed chunk */
+            png_write_tEXt(png_ptr, info_ptr->text[i].key,
+                info_ptr->text[i].text, 0);
+#else
+            png_warning(png_ptr, "Unable to write uncompressed text");
+#endif
+            /* Mark this chunk as written */
+            info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
+         }
+      }
+#endif
+#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+   if (info_ptr->unknown_chunks_num)
+   {
+      png_unknown_chunk *up;
+      png_debug(5, "writing extra chunks");
+      for (up = info_ptr->unknown_chunks;
+           up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
+           up++)
+      {
+         int keep = png_handle_as_unknown(png_ptr, up->name);
+         if (keep != PNG_HANDLE_CHUNK_NEVER &&
+             up->location &&
+             (up->location & PNG_AFTER_IDAT) &&
+             ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
+             (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
+         {
+            png_write_chunk(png_ptr, up->name, up->data, up->size);
+         }
+      }
+   }
+#endif
+   }
+   png_ptr->mode |= PNG_AFTER_IDAT;
+   /* Write end of PNG file */
+   png_write_IEND(png_ptr);
+   /* This flush, added in libpng-1.0.8, removed from libpng-1.0.9beta03,
+    * and restored again in libpng-1.2.30, may cause some applications that
+    * do not set png_ptr->output_flush_fn to crash.  If your application
+    * experiences a problem, please try building libpng with
+    * PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED defined, and report the event to
+    * png-mng-implement at lists.sf.net .
+    */
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+#  ifdef PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED
+   png_flush(png_ptr);
+#  endif
+#endif
+}
+#ifdef PNG_CONVERT_tIME_SUPPORTED
+/* "tm" structure is not supported on WindowsCE */
+void PNGAPI
+png_convert_from_struct_tm(png_timep ptime, PNG_CONST struct tm FAR * ttime)
+{
+   png_debug(1, "in png_convert_from_struct_tm");
+   ptime->year = (png_uint_16)(1900 + ttime->tm_year);
+   ptime->month = (png_byte)(ttime->tm_mon + 1);
+   ptime->day = (png_byte)ttime->tm_mday;
+   ptime->hour = (png_byte)ttime->tm_hour;
+   ptime->minute = (png_byte)ttime->tm_min;
+   ptime->second = (png_byte)ttime->tm_sec;
+}
+void PNGAPI
+png_convert_from_time_t(png_timep ptime, time_t ttime)
+{
+   struct tm *tbuf;
+   png_debug(1, "in png_convert_from_time_t");
+   tbuf = gmtime(&ttime);
+   png_convert_from_struct_tm(ptime, tbuf);
+}
+#endif
+/* Initialize png_ptr structure, and allocate any memory needed */
+PNG_FUNCTION(png_structp,PNGAPI
+png_create_write_struct,(png_const_charp user_png_ver, png_voidp error_ptr,
+    png_error_ptr error_fn, png_error_ptr warn_fn),PNG_ALLOCATED)
+{
+#ifdef PNG_USER_MEM_SUPPORTED
+   return (png_create_write_struct_2(user_png_ver, error_ptr, error_fn,
+       warn_fn, NULL, NULL, NULL));
+}
+/* Alternate initialize png_ptr structure, and allocate any memory needed */
+static void png_reset_filter_heuristics(png_structp png_ptr); /* forward decl */
+PNG_FUNCTION(png_structp,PNGAPI
+png_create_write_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
+    png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
+    png_malloc_ptr malloc_fn, png_free_ptr free_fn),PNG_ALLOCATED)
+{
+#endif /* PNG_USER_MEM_SUPPORTED */
+   volatile int png_cleanup_needed = 0;
+#ifdef PNG_SETJMP_SUPPORTED
+   volatile
+#endif
+   png_structp png_ptr;
+#ifdef PNG_SETJMP_SUPPORTED
+#ifdef USE_FAR_KEYWORD
+   jmp_buf tmp_jmpbuf;
+#endif
+#endif
+   png_debug(1, "in png_create_write_struct");
+#ifdef PNG_USER_MEM_SUPPORTED
+   png_ptr = (png_structp)png_create_struct_2(PNG_STRUCT_PNG,
+       (png_malloc_ptr)malloc_fn, (png_voidp)mem_ptr);
+#else
+   png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
+#endif /* PNG_USER_MEM_SUPPORTED */
+   if (png_ptr == NULL)
+      return (NULL);
+   /* Added at libpng-1.2.6 */
+#ifdef PNG_SET_USER_LIMITS_SUPPORTED
+   png_ptr->user_width_max = PNG_USER_WIDTH_MAX;
+   png_ptr->user_height_max = PNG_USER_HEIGHT_MAX;
+#endif
+#ifdef PNG_SETJMP_SUPPORTED
+/* Applications that neglect to set up their own setjmp() and then
+ * encounter a png_error() will longjmp here.  Since the jmpbuf is
+ * then meaningless we abort instead of returning.
+ */
+#ifdef USE_FAR_KEYWORD
+   if (setjmp(tmp_jmpbuf))
+#else
+   if (setjmp(png_jmpbuf(png_ptr))) /* sets longjmp to match setjmp */
+#endif
+#ifdef USE_FAR_KEYWORD
+   png_memcpy(png_jmpbuf(png_ptr), tmp_jmpbuf, png_sizeof(jmp_buf));
+#endif
+      PNG_ABORT();
+#endif
+#ifdef PNG_USER_MEM_SUPPORTED
+   png_set_mem_fn(png_ptr, mem_ptr, malloc_fn, free_fn);
+#endif /* PNG_USER_MEM_SUPPORTED */
+   png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn);
+   if (!png_user_version_check(png_ptr, user_png_ver))
+      png_cleanup_needed = 1;
+   /* Initialize zbuf - compression buffer */
+   png_ptr->zbuf_size = PNG_ZBUF_SIZE;
+   if (!png_cleanup_needed)
+   {
+      png_ptr->zbuf = (png_bytep)png_malloc_warn(png_ptr,
+          png_ptr->zbuf_size);
+      if (png_ptr->zbuf == NULL)
+         png_cleanup_needed = 1;
+   }
+   if (png_cleanup_needed)
+   {
+       /* Clean up PNG structure and deallocate any memory. */
+       png_free(png_ptr, png_ptr->zbuf);
+       png_ptr->zbuf = NULL;
+#ifdef PNG_USER_MEM_SUPPORTED
+       png_destroy_struct_2((png_voidp)png_ptr,
+           (png_free_ptr)free_fn, (png_voidp)mem_ptr);
+#else
+       png_destroy_struct((png_voidp)png_ptr);
+#endif
+       return (NULL);
+   }
+   png_set_write_fn(png_ptr, NULL, NULL, NULL);
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+   png_reset_filter_heuristics(png_ptr);
+#endif
+   return (png_ptr);
+}
+/* Write a few rows of image data.  If the image is interlaced,
+ * either you will have to write the 7 sub images, or, if you
+ * have called png_set_interlace_handling(), you will have to
+ * "write" the image seven times.
+ */
+void PNGAPI
+png_write_rows(png_structp png_ptr, png_bytepp row,
+    png_uint_32 num_rows)
+{
+   png_uint_32 i; /* row counter */
+   png_bytepp rp; /* row pointer */
+   png_debug(1, "in png_write_rows");
+   if (png_ptr == NULL)
+      return;
+   /* Loop through the rows */
+   for (i = 0, rp = row; i < num_rows; i++, rp++)
+   {
+      png_write_row(png_ptr, *rp);
+   }
+}
+/* Write the image.  You only need to call this function once, even
+ * if you are writing an interlaced image.
+ */
+void PNGAPI
+png_write_image(png_structp png_ptr, png_bytepp image)
+{
+   png_uint_32 i; /* row index */
+   int pass, num_pass; /* pass variables */
+   png_bytepp rp; /* points to current row */
+   if (png_ptr == NULL)
+      return;
+   png_debug(1, "in png_write_image");
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+   /* Initialize interlace handling.  If image is not interlaced,
+    * this will set pass to 1
+    */
+   num_pass = png_set_interlace_handling(png_ptr);
+#else
+   num_pass = 1;
+#endif
+   /* Loop through passes */
+   for (pass = 0; pass < num_pass; pass++)
+   {
+      /* Loop through image */
+      for (i = 0, rp = image; i < png_ptr->height; i++, rp++)
+      {
+         png_write_row(png_ptr, *rp);
+      }
+   }
+}
+/* Called by user to write a row of image data */
+void PNGAPI
+png_write_row(png_structp png_ptr, png_const_bytep row)
+{
+   /* 1.5.6: moved from png_struct to be a local structure: */
+   png_row_info row_info;
+   if (png_ptr == NULL)
+      return;
+   png_debug2(1, "in png_write_row (row %u, pass %d)",
+      png_ptr->row_number, png_ptr->pass);
+   /* Initialize transformations and other stuff if first time */
+   if (png_ptr->row_number == 0 && png_ptr->pass == 0)
+   {
+      /* Make sure we wrote the header info */
+      if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE))
+         png_error(png_ptr,
+             "png_write_info was never called before png_write_row");
+      /* Check for transforms that have been set but were defined out */
+#if !defined(PNG_WRITE_INVERT_SUPPORTED) && defined(PNG_READ_INVERT_SUPPORTED)
+      if (png_ptr->transformations & PNG_INVERT_MONO)
+         png_warning(png_ptr, "PNG_WRITE_INVERT_SUPPORTED is not defined");
+#endif
+#if !defined(PNG_WRITE_FILLER_SUPPORTED) && defined(PNG_READ_FILLER_SUPPORTED)
+      if (png_ptr->transformations & PNG_FILLER)
+         png_warning(png_ptr, "PNG_WRITE_FILLER_SUPPORTED is not defined");
+#endif
+#if !defined(PNG_WRITE_PACKSWAP_SUPPORTED) && \
+    defined(PNG_READ_PACKSWAP_SUPPORTED)
+      if (png_ptr->transformations & PNG_PACKSWAP)
+         png_warning(png_ptr,
+             "PNG_WRITE_PACKSWAP_SUPPORTED is not defined");
+#endif
+#if !defined(PNG_WRITE_PACK_SUPPORTED) && defined(PNG_READ_PACK_SUPPORTED)
+      if (png_ptr->transformations & PNG_PACK)
+         png_warning(png_ptr, "PNG_WRITE_PACK_SUPPORTED is not defined");
+#endif
+#if !defined(PNG_WRITE_SHIFT_SUPPORTED) && defined(PNG_READ_SHIFT_SUPPORTED)
+      if (png_ptr->transformations & PNG_SHIFT)
+         png_warning(png_ptr, "PNG_WRITE_SHIFT_SUPPORTED is not defined");
+#endif
+#if !defined(PNG_WRITE_BGR_SUPPORTED) && defined(PNG_READ_BGR_SUPPORTED)
+      if (png_ptr->transformations & PNG_BGR)
+         png_warning(png_ptr, "PNG_WRITE_BGR_SUPPORTED is not defined");
+#endif
+#if !defined(PNG_WRITE_SWAP_SUPPORTED) && defined(PNG_READ_SWAP_SUPPORTED)
+      if (png_ptr->transformations & PNG_SWAP_BYTES)
+         png_warning(png_ptr, "PNG_WRITE_SWAP_SUPPORTED is not defined");
+#endif
+      png_write_start_row(png_ptr);
+   }
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+   /* If interlaced and not interested in row, return */
+   if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
+   {
+      switch (png_ptr->pass)
+      {
+         case 0:
+            if (png_ptr->row_number & 0x07)
+            {
+               png_write_finish_row(png_ptr);
+               return;
+            }
+            break;
+         case 1:
+            if ((png_ptr->row_number & 0x07) || png_ptr->width < 5)
+            {
+               png_write_finish_row(png_ptr);
+               return;
+            }
+            break;
+         case 2:
+            if ((png_ptr->row_number & 0x07) != 4)
+            {
+               png_write_finish_row(png_ptr);
+               return;
+            }
+            break;
+         case 3:
+            if ((png_ptr->row_number & 0x03) || png_ptr->width < 3)
+            {
+               png_write_finish_row(png_ptr);
+               return;
+            }
+            break;
+         case 4:
+            if ((png_ptr->row_number & 0x03) != 2)
+            {
+               png_write_finish_row(png_ptr);
+               return;
+            }
+            break;
+         case 5:
+            if ((png_ptr->row_number & 0x01) || png_ptr->width < 2)
+            {
+               png_write_finish_row(png_ptr);
+               return;
+            }
+            break;
+         case 6:
+            if (!(png_ptr->row_number & 0x01))
+            {
+               png_write_finish_row(png_ptr);
+               return;
+            }
+            break;
+         default: /* error: ignore it */
+            break;
+      }
+   }
+#endif
+   /* Set up row info for transformations */
+   row_info.color_type = png_ptr->color_type;
+   row_info.width = png_ptr->usr_width;
+   row_info.channels = png_ptr->usr_channels;
+   row_info.bit_depth = png_ptr->usr_bit_depth;
+   row_info.pixel_depth = (png_byte)(row_info.bit_depth * row_info.channels);
+   row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width);
+   png_debug1(3, "row_info->color_type = %d", row_info.color_type);
+   png_debug1(3, "row_info->width = %u", row_info.width);
+   png_debug1(3, "row_info->channels = %d", row_info.channels);
+   png_debug1(3, "row_info->bit_depth = %d", row_info.bit_depth);
+   png_debug1(3, "row_info->pixel_depth = %d", row_info.pixel_depth);
+   png_debug1(3, "row_info->rowbytes = %lu", (unsigned long)row_info.rowbytes);
+   /* Copy user's row into buffer, leaving room for filter byte. */
+   png_memcpy(png_ptr->row_buf + 1, row, row_info.rowbytes);
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+   /* Handle interlacing */
+   if (png_ptr->interlaced && png_ptr->pass < 6 &&
+       (png_ptr->transformations & PNG_INTERLACE))
+   {
+      png_do_write_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass);
+      /* This should always get caught above, but still ... */
+      if (!(row_info.width))
+      {
+         png_write_finish_row(png_ptr);
+         return;
+      }
+   }
+#endif
+#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
+   /* Handle other transformations */
+   if (png_ptr->transformations)
+      png_do_write_transformations(png_ptr, &row_info);
+#endif
+   /* At this point the row_info pixel depth must match the 'transformed' depth,
+    * which is also the output depth.
+    */
+   if (row_info.pixel_depth != png_ptr->pixel_depth ||
+      row_info.pixel_depth != png_ptr->transformed_pixel_depth)
+      png_error(png_ptr, "internal write transform logic error");
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+   /* Write filter_method 64 (intrapixel differencing) only if
+    * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
+    * 2. Libpng did not write a PNG signature (this filter_method is only
+    *    used in PNG datastreams that are embedded in MNG datastreams) and
+    * 3. The application called png_permit_mng_features with a mask that
+    *    included PNG_FLAG_MNG_FILTER_64 and
+    * 4. The filter_method is 64 and
+    * 5. The color_type is RGB or RGBA
+    */
+   if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
+       (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
+   {
+      /* Intrapixel differencing */
+      png_do_write_intrapixel(&row_info, png_ptr->row_buf + 1);
+   }
+#endif
+   /* Find a filter if necessary, filter the row and write it out. */
+   png_write_find_filter(png_ptr, &row_info);
+   if (png_ptr->write_row_fn != NULL)
+      (*(png_ptr->write_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);
+}
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+/* Set the automatic flush interval or 0 to turn flushing off */
+void PNGAPI
+png_set_flush(png_structp png_ptr, int nrows)
+{
+   png_debug(1, "in png_set_flush");
+   if (png_ptr == NULL)
+      return;
+   png_ptr->flush_dist = (nrows < 0 ? 0 : nrows);
+}
+/* Flush the current output buffers now */
+void PNGAPI
+png_write_flush(png_structp png_ptr)
+{
+   int wrote_IDAT;
+   png_debug(1, "in png_write_flush");
+   if (png_ptr == NULL)
+      return;
+   /* We have already written out all of the data */
+   if (png_ptr->row_number >= png_ptr->num_rows)
+      return;
+   do
+   {
+      int ret;
+      /* Compress the data */
+      ret = deflate(&png_ptr->zstream, Z_SYNC_FLUSH);
+      wrote_IDAT = 0;
+      /* Check for compression errors */
+      if (ret != Z_OK)
+      {
+         if (png_ptr->zstream.msg != NULL)
+            png_error(png_ptr, png_ptr->zstream.msg);
+         else
+            png_error(png_ptr, "zlib error");
+      }
+      if (!(png_ptr->zstream.avail_out))
+      {
+         /* Write the IDAT and reset the zlib output buffer */
+         png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
+         wrote_IDAT = 1;
+      }
+   } while (wrote_IDAT == 1);
+   /* If there is any data left to be output, write it into a new IDAT */
+   if (png_ptr->zbuf_size != png_ptr->zstream.avail_out)
+   {
+      /* Write the IDAT and reset the zlib output buffer */
+      png_write_IDAT(png_ptr, png_ptr->zbuf,
+          png_ptr->zbuf_size - png_ptr->zstream.avail_out);
+   }
+   png_ptr->flush_rows = 0;
+   png_flush(png_ptr);
+}
+#endif /* PNG_WRITE_FLUSH_SUPPORTED */
+/* Free all memory used by the write */
+void PNGAPI
+png_destroy_write_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr)
+{
+   png_structp png_ptr = NULL;
+   png_infop info_ptr = NULL;
+#ifdef PNG_USER_MEM_SUPPORTED
+   png_free_ptr free_fn = NULL;
+   png_voidp mem_ptr = NULL;
+#endif
+   png_debug(1, "in png_destroy_write_struct");
+   if (png_ptr_ptr != NULL)
+      png_ptr = *png_ptr_ptr;
+#ifdef PNG_USER_MEM_SUPPORTED
+   if (png_ptr != NULL)
+   {
+      free_fn = png_ptr->free_fn;
+      mem_ptr = png_ptr->mem_ptr;
+   }
+#endif
+   if (info_ptr_ptr != NULL)
+      info_ptr = *info_ptr_ptr;
+   if (info_ptr != NULL)
+   {
+      if (png_ptr != NULL)
+      {
+         png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1);
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+         if (png_ptr->num_chunk_list)
+         {
+            png_free(png_ptr, png_ptr->chunk_list);
+            png_ptr->num_chunk_list = 0;
+         }
+#endif
+      }
+#ifdef PNG_USER_MEM_SUPPORTED
+      png_destroy_struct_2((png_voidp)info_ptr, (png_free_ptr)free_fn,
+          (png_voidp)mem_ptr);
+#else
+      png_destroy_struct((png_voidp)info_ptr);
+#endif
+      *info_ptr_ptr = NULL;
+   }
+   if (png_ptr != NULL)
+   {
+      png_write_destroy(png_ptr);
+#ifdef PNG_USER_MEM_SUPPORTED
+      png_destroy_struct_2((png_voidp)png_ptr, (png_free_ptr)free_fn,
+          (png_voidp)mem_ptr);
+#else
+      png_destroy_struct((png_voidp)png_ptr);
+#endif
+      *png_ptr_ptr = NULL;
+   }
+}
+/* Free any memory used in png_ptr struct (old method) */
+void /* PRIVATE */
+png_write_destroy(png_structp png_ptr)
+{
+#ifdef PNG_SETJMP_SUPPORTED
+   jmp_buf tmp_jmp; /* Save jump buffer */
+#endif
+   png_error_ptr error_fn;
+#ifdef PNG_WARNINGS_SUPPORTED
+   png_error_ptr warning_fn;
+#endif
+   png_voidp error_ptr;
+#ifdef PNG_USER_MEM_SUPPORTED
+   png_free_ptr free_fn;
+#endif
+   png_debug(1, "in png_write_destroy");
+   /* Free any memory zlib uses */
+   if (png_ptr->zlib_state != PNG_ZLIB_UNINITIALIZED)
+      deflateEnd(&png_ptr->zstream);
+   /* Free our memory.  png_free checks NULL for us. */
+   png_free(png_ptr, png_ptr->zbuf);
+   png_free(png_ptr, png_ptr->row_buf);
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+   png_free(png_ptr, png_ptr->prev_row);
+   png_free(png_ptr, png_ptr->sub_row);
+   png_free(png_ptr, png_ptr->up_row);
+   png_free(png_ptr, png_ptr->avg_row);
+   png_free(png_ptr, png_ptr->paeth_row);
+#endif
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+   /* Use this to save a little code space, it doesn't free the filter_costs */
+   png_reset_filter_heuristics(png_ptr);
+   png_free(png_ptr, png_ptr->filter_costs);
+   png_free(png_ptr, png_ptr->inv_filter_costs);
+#endif
+#ifdef PNG_SETJMP_SUPPORTED
+   /* Reset structure */
+   png_memcpy(tmp_jmp, png_ptr->longjmp_buffer, png_sizeof(jmp_buf));
+#endif
+   error_fn = png_ptr->error_fn;
+#ifdef PNG_WARNINGS_SUPPORTED
+   warning_fn = png_ptr->warning_fn;
+#endif
+   error_ptr = png_ptr->error_ptr;
+#ifdef PNG_USER_MEM_SUPPORTED
+   free_fn = png_ptr->free_fn;
+#endif
+   png_memset(png_ptr, 0, png_sizeof(png_struct));
+   png_ptr->error_fn = error_fn;
+#ifdef PNG_WARNINGS_SUPPORTED
+   png_ptr->warning_fn = warning_fn;
+#endif
+   png_ptr->error_ptr = error_ptr;
+#ifdef PNG_USER_MEM_SUPPORTED
+   png_ptr->free_fn = free_fn;
+#endif
+#ifdef PNG_SETJMP_SUPPORTED
+   png_memcpy(png_ptr->longjmp_buffer, tmp_jmp, png_sizeof(jmp_buf));
+#endif
+}
+/* Allow the application to select one or more row filters to use. */
+void PNGAPI
+png_set_filter(png_structp png_ptr, int method, int filters)
+{
+   png_debug(1, "in png_set_filter");
+   if (png_ptr == NULL)
+      return;
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+   if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
+       (method == PNG_INTRAPIXEL_DIFFERENCING))
+      method = PNG_FILTER_TYPE_BASE;
+#endif
+   if (method == PNG_FILTER_TYPE_BASE)
+   {
+      switch (filters & (PNG_ALL_FILTERS | 0x07))
+      {
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+         case 5:
+         case 6:
+         case 7: png_warning(png_ptr, "Unknown row filter for method 0");
+#endif /* PNG_WRITE_FILTER_SUPPORTED */
+         case PNG_FILTER_VALUE_NONE:
+            png_ptr->do_filter = PNG_FILTER_NONE; break;
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+         case PNG_FILTER_VALUE_SUB:
+            png_ptr->do_filter = PNG_FILTER_SUB; break;
+         case PNG_FILTER_VALUE_UP:
+            png_ptr->do_filter = PNG_FILTER_UP; break;
+         case PNG_FILTER_VALUE_AVG:
+            png_ptr->do_filter = PNG_FILTER_AVG; break;
+         case PNG_FILTER_VALUE_PAETH:
+            png_ptr->do_filter = PNG_FILTER_PAETH; break;
+         default:
+            png_ptr->do_filter = (png_byte)filters; break;
+#else
+         default:
+            png_warning(png_ptr, "Unknown row filter for method 0");
+#endif /* PNG_WRITE_FILTER_SUPPORTED */
+      }
+      /* If we have allocated the row_buf, this means we have already started
+       * with the image and we should have allocated all of the filter buffers
+       * that have been selected.  If prev_row isn't already allocated, then
+       * it is too late to start using the filters that need it, since we
+       * will be missing the data in the previous row.  If an application
+       * wants to start and stop using particular filters during compression,
+       * it should start out with all of the filters, and then add and
+       * remove them after the start of compression.
+       */
+      if (png_ptr->row_buf != NULL)
+      {
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+         if ((png_ptr->do_filter & PNG_FILTER_SUB) && png_ptr->sub_row == NULL)
+         {
+            png_ptr->sub_row = (png_bytep)png_malloc(png_ptr,
+                (png_ptr->rowbytes + 1));
+            png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;
+         }
+         if ((png_ptr->do_filter & PNG_FILTER_UP) && png_ptr->up_row == NULL)
+         {
+            if (png_ptr->prev_row == NULL)
+            {
+               png_warning(png_ptr, "Can't add Up filter after starting");
+               png_ptr->do_filter = (png_byte)(png_ptr->do_filter &
+                   ~PNG_FILTER_UP);
+            }
+            else
+            {
+               png_ptr->up_row = (png_bytep)png_malloc(png_ptr,
+                   (png_ptr->rowbytes + 1));
+               png_ptr->up_row[0] = PNG_FILTER_VALUE_UP;
+            }
+         }
+         if ((png_ptr->do_filter & PNG_FILTER_AVG) && png_ptr->avg_row == NULL)
+         {
+            if (png_ptr->prev_row == NULL)
+            {
+               png_warning(png_ptr, "Can't add Average filter after starting");
+               png_ptr->do_filter = (png_byte)(png_ptr->do_filter &
+                   ~PNG_FILTER_AVG);
+            }
+            else
+            {
+               png_ptr->avg_row = (png_bytep)png_malloc(png_ptr,
+                   (png_ptr->rowbytes + 1));
+               png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG;
+            }
+         }
+         if ((png_ptr->do_filter & PNG_FILTER_PAETH) &&
+             png_ptr->paeth_row == NULL)
+         {
+            if (png_ptr->prev_row == NULL)
+            {
+               png_warning(png_ptr, "Can't add Paeth filter after starting");
+               png_ptr->do_filter &= (png_byte)(~PNG_FILTER_PAETH);
+            }
+            else
+            {
+               png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr,
+                   (png_ptr->rowbytes + 1));
+               png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH;
+            }
+         }
+         if (png_ptr->do_filter == PNG_NO_FILTERS)
+#endif /* PNG_WRITE_FILTER_SUPPORTED */
+            png_ptr->do_filter = PNG_FILTER_NONE;
+      }
+   }
+   else
+      png_error(png_ptr, "Unknown custom filter method");
+}
+/* This allows us to influence the way in which libpng chooses the "best"
+ * filter for the current scanline.  While the "minimum-sum-of-absolute-
+ * differences metric is relatively fast and effective, there is some
+ * question as to whether it can be improved upon by trying to keep the
+ * filtered data going to zlib more consistent, hopefully resulting in
+ * better compression.
+ */
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED      /* GRR 970116 */
+/* Convenience reset API. */
+static void
+png_reset_filter_heuristics(png_structp png_ptr)
+{
+   /* Clear out any old values in the 'weights' - this must be done because if
+    * the app calls set_filter_heuristics multiple times with different
+    * 'num_weights' values we would otherwise potentially have wrong sized
+    * arrays.
+    */
+   png_ptr->num_prev_filters = 0;
+   png_ptr->heuristic_method = PNG_FILTER_HEURISTIC_UNWEIGHTED;
+   if (png_ptr->prev_filters != NULL)
+   {
+      png_bytep old = png_ptr->prev_filters;
+      png_ptr->prev_filters = NULL;
+      png_free(png_ptr, old);
+   }
+   if (png_ptr->filter_weights != NULL)
+   {
+      png_uint_16p old = png_ptr->filter_weights;
+      png_ptr->filter_weights = NULL;
+      png_free(png_ptr, old);
+   }
+   if (png_ptr->inv_filter_weights != NULL)
+   {
+      png_uint_16p old = png_ptr->inv_filter_weights;
+      png_ptr->inv_filter_weights = NULL;
+      png_free(png_ptr, old);
+   }
+   /* Leave the filter_costs - this array is fixed size. */
+}
+static int
+png_init_filter_heuristics(png_structp png_ptr, int heuristic_method,
+   int num_weights)
+{
+   if (png_ptr == NULL)
+      return 0;
+   /* Clear out the arrays */
+   png_reset_filter_heuristics(png_ptr);
+   /* Check arguments; the 'reset' function makes the correct settings for the
+    * unweighted case, but we must handle the weight case by initializing the
+    * arrays for the caller.
+    */
+   if (heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
+   {
+      int i;
+      if (num_weights > 0)
+      {
+         png_ptr->prev_filters = (png_bytep)png_malloc(png_ptr,
+             (png_uint_32)(png_sizeof(png_byte) * num_weights));
+         /* To make sure that the weighting starts out fairly */
+         for (i = 0; i < num_weights; i++)
+         {
+            png_ptr->prev_filters[i] = 255;
+         }
+         png_ptr->filter_weights = (png_uint_16p)png_malloc(png_ptr,
+             (png_uint_32)(png_sizeof(png_uint_16) * num_weights));
+         png_ptr->inv_filter_weights = (png_uint_16p)png_malloc(png_ptr,
+             (png_uint_32)(png_sizeof(png_uint_16) * num_weights));
+         for (i = 0; i < num_weights; i++)
+         {
+            png_ptr->inv_filter_weights[i] =
+            png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
+         }
+         /* Safe to set this now */
+         png_ptr->num_prev_filters = (png_byte)num_weights;
+      }
+      /* If, in the future, there are other filter methods, this would
+       * need to be based on png_ptr->filter.
+       */
+      if (png_ptr->filter_costs == NULL)
+      {
+         png_ptr->filter_costs = (png_uint_16p)png_malloc(png_ptr,
+             (png_uint_32)(png_sizeof(png_uint_16) * PNG_FILTER_VALUE_LAST));
+         png_ptr->inv_filter_costs = (png_uint_16p)png_malloc(png_ptr,
+             (png_uint_32)(png_sizeof(png_uint_16) * PNG_FILTER_VALUE_LAST));
+      }
+      for (i = 0; i < PNG_FILTER_VALUE_LAST; i++)
+      {
+         png_ptr->inv_filter_costs[i] =
+         png_ptr->filter_costs[i] = PNG_COST_FACTOR;
+      }
+      /* All the arrays are inited, safe to set this: */
+      png_ptr->heuristic_method = PNG_FILTER_HEURISTIC_WEIGHTED;
+      /* Return the 'ok' code. */
+      return 1;
+   }
+   else if (heuristic_method == PNG_FILTER_HEURISTIC_DEFAULT ||
+      heuristic_method == PNG_FILTER_HEURISTIC_UNWEIGHTED)
+   {
+      return 1;
+   }
+   else
+   {
+      png_warning(png_ptr, "Unknown filter heuristic method");
+      return 0;
+   }
+}
+/* Provide floating and fixed point APIs */
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+void PNGAPI
+png_set_filter_heuristics(png_structp png_ptr, int heuristic_method,
+    int num_weights, png_const_doublep filter_weights,
+    png_const_doublep filter_costs)
+{
+   png_debug(1, "in png_set_filter_heuristics");
+   /* The internal API allocates all the arrays and ensures that the elements of
+    * those arrays are set to the default value.
+    */
+   if (!png_init_filter_heuristics(png_ptr, heuristic_method, num_weights))
+      return;
+   /* If using the weighted method copy in the weights. */
+   if (heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
+   {
+      int i;
+      for (i = 0; i < num_weights; i++)
+      {
+         if (filter_weights[i] <= 0.0)
+         {
+            png_ptr->inv_filter_weights[i] =
+            png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
+         }
+         else
+         {
+            png_ptr->inv_filter_weights[i] =
+                (png_uint_16)(PNG_WEIGHT_FACTOR*filter_weights[i]+.5);
+            png_ptr->filter_weights[i] =
+                (png_uint_16)(PNG_WEIGHT_FACTOR/filter_weights[i]+.5);
+         }
+      }
+      /* Here is where we set the relative costs of the different filters.  We
+       * should take the desired compression level into account when setting
+       * the costs, so that Paeth, for instance, has a high relative cost at low
+       * compression levels, while it has a lower relative cost at higher
+       * compression settings.  The filter types are in order of increasing
+       * relative cost, so it would be possible to do this with an algorithm.
+       */
+      for (i = 0; i < PNG_FILTER_VALUE_LAST; i++) if (filter_costs[i] >= 1.0)
+      {
+         png_ptr->inv_filter_costs[i] =
+             (png_uint_16)(PNG_COST_FACTOR / filter_costs[i] + .5);
+         png_ptr->filter_costs[i] =
+             (png_uint_16)(PNG_COST_FACTOR * filter_costs[i] + .5);
+      }
+   }
+}
+#endif /* FLOATING_POINT */
+#ifdef PNG_FIXED_POINT_SUPPORTED
+void PNGAPI
+png_set_filter_heuristics_fixed(png_structp png_ptr, int heuristic_method,
+    int num_weights, png_const_fixed_point_p filter_weights,
+    png_const_fixed_point_p filter_costs)
+{
+   png_debug(1, "in png_set_filter_heuristics_fixed");
+   /* The internal API allocates all the arrays and ensures that the elements of
+    * those arrays are set to the default value.
+    */
+   if (!png_init_filter_heuristics(png_ptr, heuristic_method, num_weights))
+      return;
+   /* If using the weighted method copy in the weights. */
+   if (heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
+   {
+      int i;
+      for (i = 0; i < num_weights; i++)
+      {
+         if (filter_weights[i] <= 0)
+         {
+            png_ptr->inv_filter_weights[i] =
+            png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
+         }
+         else
+         {
+            png_ptr->inv_filter_weights[i] = (png_uint_16)
+               ((PNG_WEIGHT_FACTOR*filter_weights[i]+PNG_FP_HALF)/PNG_FP_1);
+            png_ptr->filter_weights[i] = (png_uint_16)((PNG_WEIGHT_FACTOR*
+               PNG_FP_1+(filter_weights[i]/2))/filter_weights[i]);
+         }
+      }
+      /* Here is where we set the relative costs of the different filters.  We
+       * should take the desired compression level into account when setting
+       * the costs, so that Paeth, for instance, has a high relative cost at low
+       * compression levels, while it has a lower relative cost at higher
+       * compression settings.  The filter types are in order of increasing
+       * relative cost, so it would be possible to do this with an algorithm.
+       */
+      for (i = 0; i < PNG_FILTER_VALUE_LAST; i++)
+         if (filter_costs[i] >= PNG_FP_1)
+      {
+         png_uint_32 tmp;
+         /* Use a 32 bit unsigned temporary here because otherwise the
+          * intermediate value will be a 32 bit *signed* integer (ANSI rules)
+          * and this will get the wrong answer on division.
+          */
+         tmp = PNG_COST_FACTOR*PNG_FP_1 + (filter_costs[i]/2);
+         tmp /= filter_costs[i];
+         png_ptr->inv_filter_costs[i] = (png_uint_16)tmp;
+         tmp = PNG_COST_FACTOR * filter_costs[i] + PNG_FP_HALF;
+         tmp /= PNG_FP_1;
+         png_ptr->filter_costs[i] = (png_uint_16)tmp;
+      }
+   }
+}
+#endif /* FIXED_POINT */
+#endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
+void PNGAPI
+png_set_compression_level(png_structp png_ptr, int level)
+{
+   png_debug(1, "in png_set_compression_level");
+   if (png_ptr == NULL)
+      return;
+   png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_LEVEL;
+   png_ptr->zlib_level = level;
+}
+void PNGAPI
+png_set_compression_mem_level(png_structp png_ptr, int mem_level)
+{
+   png_debug(1, "in png_set_compression_mem_level");
+   if (png_ptr == NULL)
+      return;
+   png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL;
+   png_ptr->zlib_mem_level = mem_level;
+}
+void PNGAPI
+png_set_compression_strategy(png_structp png_ptr, int strategy)
+{
+   png_debug(1, "in png_set_compression_strategy");
+   if (png_ptr == NULL)
+      return;
+   png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_STRATEGY;
+   png_ptr->zlib_strategy = strategy;
+}
+/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
+ * smaller value of window_bits if it can do so safely.
+ */
+void PNGAPI
+png_set_compression_window_bits(png_structp png_ptr, int window_bits)
+{
+   if (png_ptr == NULL)
+      return;
+   if (window_bits > 15)
+      png_warning(png_ptr, "Only compression windows <= 32k supported by PNG");
+   else if (window_bits < 8)
+      png_warning(png_ptr, "Only compression windows >= 256 supported by PNG");
+#ifndef WBITS_8_OK
+   /* Avoid libpng bug with 256-byte windows */
+   if (window_bits == 8)
+      {
+        png_warning(png_ptr, "Compression window is being reset to 512");
+        window_bits = 9;
+      }
+#endif
+   png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS;
+   png_ptr->zlib_window_bits = window_bits;
+}
+void PNGAPI
+png_set_compression_method(png_structp png_ptr, int method)
+{
+   png_debug(1, "in png_set_compression_method");
+   if (png_ptr == NULL)
+      return;
+   if (method != 8)
+      png_warning(png_ptr, "Only compression method 8 is supported by PNG");
+   png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_METHOD;
+   png_ptr->zlib_method = method;
+}
+/* The following were added to libpng-1.5.4 */
+#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
+void PNGAPI
+png_set_text_compression_level(png_structp png_ptr, int level)
+{
+   png_debug(1, "in png_set_text_compression_level");
+   if (png_ptr == NULL)
+      return;
+   png_ptr->flags |= PNG_FLAG_ZTXT_CUSTOM_LEVEL;
+   png_ptr->zlib_text_level = level;
+}
+void PNGAPI
+png_set_text_compression_mem_level(png_structp png_ptr, int mem_level)
+{
+   png_debug(1, "in png_set_text_compression_mem_level");
+   if (png_ptr == NULL)
+      return;
+   png_ptr->flags |= PNG_FLAG_ZTXT_CUSTOM_MEM_LEVEL;
+   png_ptr->zlib_text_mem_level = mem_level;
+}
+void PNGAPI
+png_set_text_compression_strategy(png_structp png_ptr, int strategy)
+{
+   png_debug(1, "in png_set_text_compression_strategy");
+   if (png_ptr == NULL)
+      return;
+   png_ptr->flags |= PNG_FLAG_ZTXT_CUSTOM_STRATEGY;
+   png_ptr->zlib_text_strategy = strategy;
+}
+/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
+ * smaller value of window_bits if it can do so safely.
+ */
+void PNGAPI
+png_set_text_compression_window_bits(png_structp png_ptr, int window_bits)
+{
+   if (png_ptr == NULL)
+      return;
+   if (window_bits > 15)
+      png_warning(png_ptr, "Only compression windows <= 32k supported by PNG");
+   else if (window_bits < 8)
+      png_warning(png_ptr, "Only compression windows >= 256 supported by PNG");
+#ifndef WBITS_8_OK
+   /* Avoid libpng bug with 256-byte windows */
+   if (window_bits == 8)
+      {
+        png_warning(png_ptr, "Text compression window is being reset to 512");
+        window_bits = 9;
+      }
+#endif
+   png_ptr->flags |= PNG_FLAG_ZTXT_CUSTOM_WINDOW_BITS;
+   png_ptr->zlib_text_window_bits = window_bits;
+}
+void PNGAPI
+png_set_text_compression_method(png_structp png_ptr, int method)
+{
+   png_debug(1, "in png_set_text_compression_method");
+   if (png_ptr == NULL)
+      return;
+   if (method != 8)
+      png_warning(png_ptr, "Only compression method 8 is supported by PNG");
+   png_ptr->flags |= PNG_FLAG_ZTXT_CUSTOM_METHOD;
+   png_ptr->zlib_text_method = method;
+}
+#endif /* PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED */
+/* end of API added to libpng-1.5.4 */
+void PNGAPI
+png_set_write_status_fn(png_structp png_ptr, png_write_status_ptr write_row_fn)
+{
+   if (png_ptr == NULL)
+      return;
+   png_ptr->write_row_fn = write_row_fn;
+}
+#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
+void PNGAPI
+png_set_write_user_transform_fn(png_structp png_ptr, png_user_transform_ptr
+    write_user_transform_fn)
+{
+   png_debug(1, "in png_set_write_user_transform_fn");
+   if (png_ptr == NULL)
+      return;
+   png_ptr->transformations |= PNG_USER_TRANSFORM;
+   png_ptr->write_user_transform_fn = write_user_transform_fn;
+}
+#endif
+#ifdef PNG_INFO_IMAGE_SUPPORTED
+void PNGAPI
+png_write_png(png_structp png_ptr, png_infop info_ptr,
+    int transforms, voidp params)
+{
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+   /* Write the file header information. */
+   png_write_info(png_ptr, info_ptr);
+   /* ------ these transformations don't touch the info structure ------- */
+#ifdef PNG_WRITE_INVERT_SUPPORTED
+   /* Invert monochrome pixels */
+   if (transforms & PNG_TRANSFORM_INVERT_MONO)
+      png_set_invert_mono(png_ptr);
+#endif
+#ifdef PNG_WRITE_SHIFT_SUPPORTED
+   /* Shift the pixels up to a legal bit depth and fill in
+    * as appropriate to correctly scale the image.
+    */
+   if ((transforms & PNG_TRANSFORM_SHIFT)
+       && (info_ptr->valid & PNG_INFO_sBIT))
+      png_set_shift(png_ptr, &info_ptr->sig_bit);
+#endif
+#ifdef PNG_WRITE_PACK_SUPPORTED
+   /* Pack pixels into bytes */
+   if (transforms & PNG_TRANSFORM_PACKING)
+       png_set_packing(png_ptr);
+#endif
+#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
+   /* Swap location of alpha bytes from ARGB to RGBA */
+   if (transforms & PNG_TRANSFORM_SWAP_ALPHA)
+      png_set_swap_alpha(png_ptr);
+#endif
+#ifdef PNG_WRITE_FILLER_SUPPORTED
+   /* Pack XRGB/RGBX/ARGB/RGBA into RGB (4 channels -> 3 channels) */
+   if (transforms & PNG_TRANSFORM_STRIP_FILLER_AFTER)
+      png_set_filler(png_ptr, 0, PNG_FILLER_AFTER);
+   else if (transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE)
+      png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE);
+#endif
+#ifdef PNG_WRITE_BGR_SUPPORTED
+   /* Flip BGR pixels to RGB */
+   if (transforms & PNG_TRANSFORM_BGR)
+      png_set_bgr(png_ptr);
+#endif
+#ifdef PNG_WRITE_SWAP_SUPPORTED
+   /* Swap bytes of 16-bit files to most significant byte first */
+   if (transforms & PNG_TRANSFORM_SWAP_ENDIAN)
+      png_set_swap(png_ptr);
+#endif
+#ifdef PNG_WRITE_PACKSWAP_SUPPORTED
+   /* Swap bits of 1, 2, 4 bit packed pixel formats */
+   if (transforms & PNG_TRANSFORM_PACKSWAP)
+      png_set_packswap(png_ptr);
+#endif
+#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
+   /* Invert the alpha channel from opacity to transparency */
+   if (transforms & PNG_TRANSFORM_INVERT_ALPHA)
+      png_set_invert_alpha(png_ptr);
+#endif
+   /* ----------------------- end of transformations ------------------- */
+   /* Write the bits */
+   if (info_ptr->valid & PNG_INFO_IDAT)
+       png_write_image(png_ptr, info_ptr->row_pointers);
+   /* It is REQUIRED to call this to finish writing the rest of the file */
+   png_write_end(png_ptr, info_ptr);
+   PNG_UNUSED(transforms)   /* Quiet compiler warnings */
+   PNG_UNUSED(params)
+}
+#endif
+#endif /* PNG_WRITE_SUPPORTED */
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngwtran.c b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngwtran.c
new file mode 100644
index 0000000..b598149
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngwtran.c
@@ -0,0 +1,633 @@
+/* pngwtran.c - transforms the data in a row for PNG writers
+ *
+ * Last changed in libpng 1.5.6 [November 3, 2011]
+ * Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+#include "pngpriv.h"
+#ifdef PNG_WRITE_SUPPORTED
+#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
+/* Transform the data according to the user's wishes.  The order of
+ * transformations is significant.
+ */
+void /* PRIVATE */
+png_do_write_transformations(png_structp png_ptr, png_row_infop row_info)
+{
+   png_debug(1, "in png_do_write_transformations");
+   if (png_ptr == NULL)
+      return;
+#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
+   if (png_ptr->transformations & PNG_USER_TRANSFORM)
+      if (png_ptr->write_user_transform_fn != NULL)
+         (*(png_ptr->write_user_transform_fn)) /* User write transform
+                                                 function */
+             (png_ptr,  /* png_ptr */
+             row_info,  /* row_info: */
+                /*  png_uint_32 width;       width of row */
+                /*  png_size_t rowbytes;     number of bytes in row */
+                /*  png_byte color_type;     color type of pixels */
+                /*  png_byte bit_depth;      bit depth of samples */
+                /*  png_byte channels;       number of channels (1-4) */
+                /*  png_byte pixel_depth;    bits per pixel (depth*channels) */
+             png_ptr->row_buf + 1);      /* start of pixel data for row */
+#endif
+#ifdef PNG_WRITE_FILLER_SUPPORTED
+   if (png_ptr->transformations & PNG_FILLER)
+      png_do_strip_channel(row_info, png_ptr->row_buf + 1,
+         !(png_ptr->flags & PNG_FLAG_FILLER_AFTER));
+#endif
+#ifdef PNG_WRITE_PACKSWAP_SUPPORTED
+   if (png_ptr->transformations & PNG_PACKSWAP)
+      png_do_packswap(row_info, png_ptr->row_buf + 1);
+#endif
+#ifdef PNG_WRITE_PACK_SUPPORTED
+   if (png_ptr->transformations & PNG_PACK)
+      png_do_pack(row_info, png_ptr->row_buf + 1,
+          (png_uint_32)png_ptr->bit_depth);
+#endif
+#ifdef PNG_WRITE_SWAP_SUPPORTED
+   if (png_ptr->transformations & PNG_SWAP_BYTES)
+      png_do_swap(row_info, png_ptr->row_buf + 1);
+#endif
+#ifdef PNG_WRITE_SHIFT_SUPPORTED
+   if (png_ptr->transformations & PNG_SHIFT)
+      png_do_shift(row_info, png_ptr->row_buf + 1,
+          &(png_ptr->shift));
+#endif
+#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
+   if (png_ptr->transformations & PNG_SWAP_ALPHA)
+      png_do_write_swap_alpha(row_info, png_ptr->row_buf + 1);
+#endif
+#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
+   if (png_ptr->transformations & PNG_INVERT_ALPHA)
+      png_do_write_invert_alpha(row_info, png_ptr->row_buf + 1);
+#endif
+#ifdef PNG_WRITE_BGR_SUPPORTED
+   if (png_ptr->transformations & PNG_BGR)
+      png_do_bgr(row_info, png_ptr->row_buf + 1);
+#endif
+#ifdef PNG_WRITE_INVERT_SUPPORTED
+   if (png_ptr->transformations & PNG_INVERT_MONO)
+      png_do_invert(row_info, png_ptr->row_buf + 1);
+#endif
+}
+#ifdef PNG_WRITE_PACK_SUPPORTED
+/* Pack pixels into bytes.  Pass the true bit depth in bit_depth.  The
+ * row_info bit depth should be 8 (one pixel per byte).  The channels
+ * should be 1 (this only happens on grayscale and paletted images).
+ */
+void /* PRIVATE */
+png_do_pack(png_row_infop row_info, png_bytep row, png_uint_32 bit_depth)
+{
+   png_debug(1, "in png_do_pack");
+   if (row_info->bit_depth == 8 &&
+      row_info->channels == 1)
+   {
+      switch ((int)bit_depth)
+      {
+         case 1:
+         {
+            png_bytep sp, dp;
+            int mask, v;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+            sp = row;
+            dp = row;
+            mask = 0x80;
+            v = 0;
+            for (i = 0; i < row_width; i++)
+            {
+               if (*sp != 0)
+                  v |= mask;
+               sp++;
+               if (mask > 1)
+                  mask >>= 1;
+               else
+               {
+                  mask = 0x80;
+                  *dp = (png_byte)v;
+                  dp++;
+                  v = 0;
+               }
+            }
+            if (mask != 0x80)
+               *dp = (png_byte)v;
+            break;
+         }
+         case 2:
+         {
+            png_bytep sp, dp;
+            int shift, v;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+            sp = row;
+            dp = row;
+            shift = 6;
+            v = 0;
+            for (i = 0; i < row_width; i++)
+            {
+               png_byte value;
+               value = (png_byte)(*sp & 0x03);
+               v |= (value << shift);
+               if (shift == 0)
+               {
+                  shift = 6;
+                  *dp = (png_byte)v;
+                  dp++;
+                  v = 0;
+               }
+               else
+                  shift -= 2;
+               sp++;
+            }
+            if (shift != 6)
+               *dp = (png_byte)v;
+            break;
+         }
+         case 4:
+         {
+            png_bytep sp, dp;
+            int shift, v;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+            sp = row;
+            dp = row;
+            shift = 4;
+            v = 0;
+            for (i = 0; i < row_width; i++)
+            {
+               png_byte value;
+               value = (png_byte)(*sp & 0x0f);
+               v |= (value << shift);
+               if (shift == 0)
+               {
+                  shift = 4;
+                  *dp = (png_byte)v;
+                  dp++;
+                  v = 0;
+               }
+               else
+                  shift -= 4;
+               sp++;
+            }
+            if (shift != 4)
+               *dp = (png_byte)v;
+            break;
+         }
+         default:
+            break;
+      }
+      row_info->bit_depth = (png_byte)bit_depth;
+      row_info->pixel_depth = (png_byte)(bit_depth * row_info->channels);
+      row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
+          row_info->width);
+   }
+}
+#endif
+#ifdef PNG_WRITE_SHIFT_SUPPORTED
+/* Shift pixel values to take advantage of whole range.  Pass the
+ * true number of bits in bit_depth.  The row should be packed
+ * according to row_info->bit_depth.  Thus, if you had a row of
+ * bit depth 4, but the pixels only had values from 0 to 7, you
+ * would pass 3 as bit_depth, and this routine would translate the
+ * data to 0 to 15.
+ */
+void /* PRIVATE */
+png_do_shift(png_row_infop row_info, png_bytep row,
+    png_const_color_8p bit_depth)
+{
+   png_debug(1, "in png_do_shift");
+   if (row_info->color_type != PNG_COLOR_TYPE_PALETTE)
+   {
+      int shift_start[4], shift_dec[4];
+      int channels = 0;
+      if (row_info->color_type & PNG_COLOR_MASK_COLOR)
+      {
+         shift_start[channels] = row_info->bit_depth - bit_depth->red;
+         shift_dec[channels] = bit_depth->red;
+         channels++;
+         shift_start[channels] = row_info->bit_depth - bit_depth->green;
+         shift_dec[channels] = bit_depth->green;
+         channels++;
+         shift_start[channels] = row_info->bit_depth - bit_depth->blue;
+         shift_dec[channels] = bit_depth->blue;
+         channels++;
+      }
+      else
+      {
+         shift_start[channels] = row_info->bit_depth - bit_depth->gray;
+         shift_dec[channels] = bit_depth->gray;
+         channels++;
+      }
+      if (row_info->color_type & PNG_COLOR_MASK_ALPHA)
+      {
+         shift_start[channels] = row_info->bit_depth - bit_depth->alpha;
+         shift_dec[channels] = bit_depth->alpha;
+         channels++;
+      }
+      /* With low row depths, could only be grayscale, so one channel */
+      if (row_info->bit_depth < 8)
+      {
+         png_bytep bp = row;
+         png_size_t i;
+         png_byte mask;
+         png_size_t row_bytes = row_info->rowbytes;
+         if (bit_depth->gray == 1 && row_info->bit_depth == 2)
+            mask = 0x55;
+         else if (row_info->bit_depth == 4 && bit_depth->gray == 3)
+            mask = 0x11;
+         else
+            mask = 0xff;
+         for (i = 0; i < row_bytes; i++, bp++)
+         {
+            png_uint_16 v;
+            int j;
+            v = *bp;
+            *bp = 0;
+            for (j = shift_start[0]; j > -shift_dec[0]; j -= shift_dec[0])
+            {
+               if (j > 0)
+                  *bp |= (png_byte)((v << j) & 0xff);
+               else
+                  *bp |= (png_byte)((v >> (-j)) & mask);
+            }
+         }
+      }
+      else if (row_info->bit_depth == 8)
+      {
+         png_bytep bp = row;
+         png_uint_32 i;
+         png_uint_32 istop = channels * row_info->width;
+         for (i = 0; i < istop; i++, bp++)
+         {
+            png_uint_16 v;
+            int j;
+            int c = (int)(i%channels);
+            v = *bp;
+            *bp = 0;
+            for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c])
+            {
+               if (j > 0)
+                  *bp |= (png_byte)((v << j) & 0xff);
+               else
+                  *bp |= (png_byte)((v >> (-j)) & 0xff);
+            }
+         }
+      }
+      else
+      {
+         png_bytep bp;
+         png_uint_32 i;
+         png_uint_32 istop = channels * row_info->width;
+         for (bp = row, i = 0; i < istop; i++)
+         {
+            int c = (int)(i%channels);
+            png_uint_16 value, v;
+            int j;
+            v = (png_uint_16)(((png_uint_16)(*bp) << 8) + *(bp + 1));
+            value = 0;
+            for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c])
+            {
+               if (j > 0)
+                  value |= (png_uint_16)((v << j) & (png_uint_16)0xffff);
+               else
+                  value |= (png_uint_16)((v >> (-j)) & (png_uint_16)0xffff);
+            }
+            *bp++ = (png_byte)(value >> 8);
+            *bp++ = (png_byte)(value & 0xff);
+         }
+      }
+   }
+}
+#endif
+#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
+void /* PRIVATE */
+png_do_write_swap_alpha(png_row_infop row_info, png_bytep row)
+{
+   png_debug(1, "in png_do_write_swap_alpha");
+   {
+      if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+      {
+         if (row_info->bit_depth == 8)
+         {
+            /* This converts from ARGB to RGBA */
+            png_bytep sp, dp;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+            for (i = 0, sp = dp = row; i < row_width; i++)
+            {
+               png_byte save = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = save;
+            }
+         }
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+         else
+         {
+            /* This converts from AARRGGBB to RRGGBBAA */
+            png_bytep sp, dp;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+            for (i = 0, sp = dp = row; i < row_width; i++)
+            {
+               png_byte save[2];
+               save[0] = *(sp++);
+               save[1] = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = save[0];
+               *(dp++) = save[1];
+            }
+         }
+#endif /* PNG_WRITE_16BIT_SUPPORTED */
+      }
+      else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+      {
+         if (row_info->bit_depth == 8)
+         {
+            /* This converts from AG to GA */
+            png_bytep sp, dp;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+            for (i = 0, sp = dp = row; i < row_width; i++)
+            {
+               png_byte save = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = save;
+            }
+         }
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+         else
+         {
+            /* This converts from AAGG to GGAA */
+            png_bytep sp, dp;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+            for (i = 0, sp = dp = row; i < row_width; i++)
+            {
+               png_byte save[2];
+               save[0] = *(sp++);
+               save[1] = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = save[0];
+               *(dp++) = save[1];
+            }
+         }
+#endif /* PNG_WRITE_16BIT_SUPPORTED */
+      }
+   }
+}
+#endif
+#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
+void /* PRIVATE */
+png_do_write_invert_alpha(png_row_infop row_info, png_bytep row)
+{
+   png_debug(1, "in png_do_write_invert_alpha");
+   {
+      if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+      {
+         if (row_info->bit_depth == 8)
+         {
+            /* This inverts the alpha channel in RGBA */
+            png_bytep sp, dp;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+            for (i = 0, sp = dp = row; i < row_width; i++)
+            {
+               /* Does nothing
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               */
+               sp+=3; dp = sp;
+               *(dp++) = (png_byte)(255 - *(sp++));
+            }
+         }
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+         else
+         {
+            /* This inverts the alpha channel in RRGGBBAA */
+            png_bytep sp, dp;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+            for (i = 0, sp = dp = row; i < row_width; i++)
+            {
+               /* Does nothing
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               */
+               sp+=6; dp = sp;
+               *(dp++) = (png_byte)(255 - *(sp++));
+               *(dp++) = (png_byte)(255 - *(sp++));
+            }
+         }
+#endif /* PNG_WRITE_16BIT_SUPPORTED */
+      }
+      else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+      {
+         if (row_info->bit_depth == 8)
+         {
+            /* This inverts the alpha channel in GA */
+            png_bytep sp, dp;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+            for (i = 0, sp = dp = row; i < row_width; i++)
+            {
+               *(dp++) = *(sp++);
+               *(dp++) = (png_byte)(255 - *(sp++));
+            }
+         }
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+         else
+         {
+            /* This inverts the alpha channel in GGAA */
+            png_bytep sp, dp;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+            for (i = 0, sp = dp = row; i < row_width; i++)
+            {
+               /* Does nothing
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               */
+               sp+=2; dp = sp;
+               *(dp++) = (png_byte)(255 - *(sp++));
+               *(dp++) = (png_byte)(255 - *(sp++));
+            }
+         }
+#endif /* PNG_WRITE_16BIT_SUPPORTED */
+      }
+   }
+}
+#endif
+#endif /* PNG_WRITE_TRANSFORMS_SUPPORTED */
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+/* Undoes intrapixel differencing  */
+void /* PRIVATE */
+png_do_write_intrapixel(png_row_infop row_info, png_bytep row)
+{
+   png_debug(1, "in png_do_write_intrapixel");
+   if ((row_info->color_type & PNG_COLOR_MASK_COLOR))
+   {
+      int bytes_per_pixel;
+      png_uint_32 row_width = row_info->width;
+      if (row_info->bit_depth == 8)
+      {
+         png_bytep rp;
+         png_uint_32 i;
+         if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+            bytes_per_pixel = 3;
+         else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+            bytes_per_pixel = 4;
+         else
+            return;
+         for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
+         {
+            *(rp)     = (png_byte)((*rp       - *(rp + 1)) & 0xff);
+            *(rp + 2) = (png_byte)((*(rp + 2) - *(rp + 1)) & 0xff);
+         }
+      }
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+      else if (row_info->bit_depth == 16)
+      {
+         png_bytep rp;
+         png_uint_32 i;
+         if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+            bytes_per_pixel = 6;
+         else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+            bytes_per_pixel = 8;
+         else
+            return;
+         for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
+         {
+            png_uint_32 s0   = (*(rp    ) << 8) | *(rp + 1);
+            png_uint_32 s1   = (*(rp + 2) << 8) | *(rp + 3);
+            png_uint_32 s2   = (*(rp + 4) << 8) | *(rp + 5);
+            png_uint_32 red  = (png_uint_32)((s0 - s1) & 0xffffL);
+            png_uint_32 blue = (png_uint_32)((s2 - s1) & 0xffffL);
+            *(rp    ) = (png_byte)((red >> 8) & 0xff);
+            *(rp + 1) = (png_byte)(red & 0xff);
+            *(rp + 4) = (png_byte)((blue >> 8) & 0xff);
+            *(rp + 5) = (png_byte)(blue & 0xff);
+         }
+      }
+#endif /* PNG_WRITE_16BIT_SUPPORTED */
+   }
+}
+#endif /* PNG_MNG_FEATURES_SUPPORTED */
+#endif /* PNG_WRITE_SUPPORTED */
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngwutil.c b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngwutil.c
new file mode 100644
index 0000000..64888f7
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngwutil.c
@@ -0,0 +1,3180 @@
+/* pngwutil.c - utilities to write a PNG file
+ *
+ * Last changed in libpng 1.5.6 [November 3, 2011]
+ * Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+#include "pngpriv.h"
+#ifdef PNG_WRITE_SUPPORTED
+#ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
+/* Place a 32-bit number into a buffer in PNG byte order.  We work
+ * with unsigned numbers for convenience, although one supported
+ * ancillary chunk uses signed (two's complement) numbers.
+ */
+void PNGAPI
+png_save_uint_32(png_bytep buf, png_uint_32 i)
+{
+   buf[0] = (png_byte)((i >> 24) & 0xff);
+   buf[1] = (png_byte)((i >> 16) & 0xff);
+   buf[2] = (png_byte)((i >> 8) & 0xff);
+   buf[3] = (png_byte)(i & 0xff);
+}
+#ifdef PNG_SAVE_INT_32_SUPPORTED
+/* The png_save_int_32 function assumes integers are stored in two's
+ * complement format.  If this isn't the case, then this routine needs to
+ * be modified to write data in two's complement format.  Note that,
+ * the following works correctly even if png_int_32 has more than 32 bits
+ * (compare the more complex code required on read for sign extention.)
+ */
+void PNGAPI
+png_save_int_32(png_bytep buf, png_int_32 i)
+{
+   buf[0] = (png_byte)((i >> 24) & 0xff);
+   buf[1] = (png_byte)((i >> 16) & 0xff);
+   buf[2] = (png_byte)((i >> 8) & 0xff);
+   buf[3] = (png_byte)(i & 0xff);
+}
+#endif
+/* Place a 16-bit number into a buffer in PNG byte order.
+ * The parameter is declared unsigned int, not png_uint_16,
+ * just to avoid potential problems on pre-ANSI C compilers.
+ */
+void PNGAPI
+png_save_uint_16(png_bytep buf, unsigned int i)
+{
+   buf[0] = (png_byte)((i >> 8) & 0xff);
+   buf[1] = (png_byte)(i & 0xff);
+}
+#endif
+/* Simple function to write the signature.  If we have already written
+ * the magic bytes of the signature, or more likely, the PNG stream is
+ * being embedded into another stream and doesn't need its own signature,
+ * we should call png_set_sig_bytes() to tell libpng how many of the
+ * bytes have already been written.
+ */
+void PNGAPI
+png_write_sig(png_structp png_ptr)
+{
+   png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};
+#ifdef PNG_IO_STATE_SUPPORTED
+   /* Inform the I/O callback that the signature is being written */
+   png_ptr->io_state = PNG_IO_WRITING | PNG_IO_SIGNATURE;
+#endif
+   /* Write the rest of the 8 byte signature */
+   png_write_data(png_ptr, &png_signature[png_ptr->sig_bytes],
+      (png_size_t)(8 - png_ptr->sig_bytes));
+   if (png_ptr->sig_bytes < 3)
+      png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
+}
+/* Write the start of a PNG chunk.  The type is the chunk type.
+ * The total_length is the sum of the lengths of all the data you will be
+ * passing in png_write_chunk_data().
+ */
+static void
+png_write_chunk_header(png_structp png_ptr, png_uint_32 chunk_name,
+    png_uint_32 length)
+{
+   png_byte buf[8];
+#if defined(PNG_DEBUG) && (PNG_DEBUG > 0)
+   PNG_CSTRING_FROM_CHUNK(buf, chunk_name);
+   png_debug2(0, "Writing %s chunk, length = %lu", buf, (unsigned long)length);
+#endif
+   if (png_ptr == NULL)
+      return;
+#ifdef PNG_IO_STATE_SUPPORTED
+   /* Inform the I/O callback that the chunk header is being written.
+    * PNG_IO_CHUNK_HDR requires a single I/O call.
+    */
+   png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_HDR;
+#endif
+   /* Write the length and the chunk name */
+   png_save_uint_32(buf, length);
+   png_save_uint_32(buf + 4, chunk_name);
+   png_write_data(png_ptr, buf, 8);
+   /* Put the chunk name into png_ptr->chunk_name */
+   png_ptr->chunk_name = chunk_name;
+   /* Reset the crc and run it over the chunk name */
+   png_reset_crc(png_ptr);
+   png_calculate_crc(png_ptr, buf + 4, 4);
+#ifdef PNG_IO_STATE_SUPPORTED
+   /* Inform the I/O callback that chunk data will (possibly) be written.
+    * PNG_IO_CHUNK_DATA does NOT require a specific number of I/O calls.
+    */
+   png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_DATA;
+#endif
+}
+void PNGAPI
+png_write_chunk_start(png_structp png_ptr, png_const_bytep chunk_string,
+    png_uint_32 length)
+{
+   png_write_chunk_header(png_ptr, PNG_CHUNK_FROM_STRING(chunk_string), length);
+}
+/* Write the data of a PNG chunk started with png_write_chunk_header().
+ * Note that multiple calls to this function are allowed, and that the
+ * sum of the lengths from these calls *must* add up to the total_length
+ * given to png_write_chunk_header().
+ */
+void PNGAPI
+png_write_chunk_data(png_structp png_ptr, png_const_bytep data,
+    png_size_t length)
+{
+   /* Write the data, and run the CRC over it */
+   if (png_ptr == NULL)
+      return;
+   if (data != NULL && length > 0)
+   {
+      png_write_data(png_ptr, data, length);
+      /* Update the CRC after writing the data,
+       * in case that the user I/O routine alters it.
+       */
+      png_calculate_crc(png_ptr, data, length);
+   }
+}
+/* Finish a chunk started with png_write_chunk_header(). */
+void PNGAPI
+png_write_chunk_end(png_structp png_ptr)
+{
+   png_byte buf[4];
+   if (png_ptr == NULL) return;
+#ifdef PNG_IO_STATE_SUPPORTED
+   /* Inform the I/O callback that the chunk CRC is being written.
+    * PNG_IO_CHUNK_CRC requires a single I/O function call.
+    */
+   png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_CRC;
+#endif
+   /* Write the crc in a single operation */
+   png_save_uint_32(buf, png_ptr->crc);
+   png_write_data(png_ptr, buf, (png_size_t)4);
+}
+/* Write a PNG chunk all at once.  The type is an array of ASCII characters
+ * representing the chunk name.  The array must be at least 4 bytes in
+ * length, and does not need to be null terminated.  To be safe, pass the
+ * pre-defined chunk names here, and if you need a new one, define it
+ * where the others are defined.  The length is the length of the data.
+ * All the data must be present.  If that is not possible, use the
+ * png_write_chunk_start(), png_write_chunk_data(), and png_write_chunk_end()
+ * functions instead.
+ */
+static void
+png_write_complete_chunk(png_structp png_ptr, png_uint_32 chunk_name,
+   png_const_bytep data, png_size_t length)
+{
+   if (png_ptr == NULL)
+      return;
+   /* On 64 bit architectures 'length' may not fit in a png_uint_32. */
+   if (length > PNG_UINT_32_MAX)
+      png_error(png_ptr, "length exceeds PNG maxima");
+   png_write_chunk_header(png_ptr, chunk_name, (png_uint_32)length);
+   png_write_chunk_data(png_ptr, data, length);
+   png_write_chunk_end(png_ptr);
+}
+/* This is the API that calls the internal function above. */
+void PNGAPI
+png_write_chunk(png_structp png_ptr, png_const_bytep chunk_string,
+   png_const_bytep data, png_size_t length)
+{
+   png_write_complete_chunk(png_ptr, PNG_CHUNK_FROM_STRING(chunk_string), data,
+      length);
+}
+/* Initialize the compressor for the appropriate type of compression. */
+static void
+png_zlib_claim(png_structp png_ptr, png_uint_32 state)
+{
+   if (!(png_ptr->zlib_state & PNG_ZLIB_IN_USE))
+   {
+      /* If already initialized for 'state' do not re-init. */
+      if (png_ptr->zlib_state != state)
+      {
+         int ret = Z_OK;
+         png_const_charp who = "-";
+         /* If actually initialized for another state do a deflateEnd. */
+         if (png_ptr->zlib_state != PNG_ZLIB_UNINITIALIZED)
+         {
+            ret = deflateEnd(&png_ptr->zstream);
+            who = "end";
+            png_ptr->zlib_state = PNG_ZLIB_UNINITIALIZED;
+         }
+         /* zlib itself detects an incomplete state on deflateEnd */
+         if (ret == Z_OK) switch (state)
+         {
+#           ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
+               case PNG_ZLIB_FOR_TEXT:
+                  ret = deflateInit2(&png_ptr->zstream,
+                     png_ptr->zlib_text_level, png_ptr->zlib_text_method,
+                     png_ptr->zlib_text_window_bits,
+                     png_ptr->zlib_text_mem_level, png_ptr->zlib_text_strategy);
+                  who = "text";
+                  break;
+#           endif
+            case PNG_ZLIB_FOR_IDAT:
+               ret = deflateInit2(&png_ptr->zstream, png_ptr->zlib_level,
+                   png_ptr->zlib_method, png_ptr->zlib_window_bits,
+                   png_ptr->zlib_mem_level, png_ptr->zlib_strategy);
+               who = "IDAT";
+               break;
+            default:
+               png_error(png_ptr, "invalid zlib state");
+         }
+         if (ret == Z_OK)
+            png_ptr->zlib_state = state;
+         else /* an error in deflateEnd or deflateInit2 */
+         {
+            size_t pos = 0;
+            char msg[64];
+            pos = png_safecat(msg, sizeof msg, pos,
+               "zlib failed to initialize compressor (");
+            pos = png_safecat(msg, sizeof msg, pos, who);
+            switch (ret)
+            {
+               case Z_VERSION_ERROR:
+                  pos = png_safecat(msg, sizeof msg, pos, ") version error");
+                  break;
+               case Z_STREAM_ERROR:
+                  pos = png_safecat(msg, sizeof msg, pos, ") stream error");
+                  break;
+               case Z_MEM_ERROR:
+                  pos = png_safecat(msg, sizeof msg, pos, ") memory error");
+                  break;
+               default:
+                  pos = png_safecat(msg, sizeof msg, pos, ") unknown error");
+                  break;
+            }
+            png_error(png_ptr, msg);
+         }
+      }
+      /* Here on success, claim the zstream: */
+      png_ptr->zlib_state |= PNG_ZLIB_IN_USE;
+   }
+   else
+      png_error(png_ptr, "zstream already in use (internal error)");
+}
+/* The opposite: release the stream.  It is also reset, this API will warn on
+ * error but will not fail.
+ */
+static void
+png_zlib_release(png_structp png_ptr)
+{
+   if (png_ptr->zlib_state & PNG_ZLIB_IN_USE)
+   {
+      int ret = deflateReset(&png_ptr->zstream);
+      png_ptr->zlib_state &= ~PNG_ZLIB_IN_USE;
+      if (ret != Z_OK)
+      {
+         png_const_charp err;
+         PNG_WARNING_PARAMETERS(p)
+         switch (ret)
+         {
+            case Z_VERSION_ERROR:
+               err = "version";
+               break;
+            case Z_STREAM_ERROR:
+               err = "stream";
+               break;
+            case Z_MEM_ERROR:
+               err = "memory";
+               break;
+            default:
+               err = "unknown";
+               break;
+         }
+         png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_d, ret);
+         png_warning_parameter(p, 2, err);
+         if (png_ptr->zstream.msg)
+            err = png_ptr->zstream.msg;
+         else
+            err = "[no zlib message]";
+         png_warning_parameter(p, 3, err);
+         png_formatted_warning(png_ptr, p,
+            "zlib failed to reset compressor: @1(@2): @3");
+      }
+   }
+   else
+      png_warning(png_ptr, "zstream not in use (internal error)");
+}
+#ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
+/* This pair of functions encapsulates the operation of (a) compressing a
+ * text string, and (b) issuing it later as a series of chunk data writes.
+ * The compression_state structure is shared context for these functions
+ * set up by the caller in order to make the whole mess thread-safe.
+ */
+typedef struct
+{
+   png_const_bytep input;   /* The uncompressed input data */
+   png_size_t input_len;    /* Its length */
+   int num_output_ptr;      /* Number of output pointers used */
+   int max_output_ptr;      /* Size of output_ptr */
+   png_bytep *output_ptr;   /* Array of pointers to output */
+} compression_state;
+/* Compress given text into storage in the png_ptr structure */
+static int /* PRIVATE */
+png_text_compress(png_structp png_ptr,
+    png_const_charp text, png_size_t text_len, int compression,
+    compression_state *comp)
+{
+   int ret;
+   comp->num_output_ptr = 0;
+   comp->max_output_ptr = 0;
+   comp->output_ptr = NULL;
+   comp->input = NULL;
+   comp->input_len = text_len;
+   /* We may just want to pass the text right through */
+   if (compression == PNG_TEXT_COMPRESSION_NONE)
+   {
+      comp->input = (png_const_bytep)text;
+      return((int)text_len);
+   }
+   if (compression >= PNG_TEXT_COMPRESSION_LAST)
+   {
+      PNG_WARNING_PARAMETERS(p)
+      png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_d,
+         compression);
+      png_formatted_warning(png_ptr, p, "Unknown compression type @1");
+   }
+   /* We can't write the chunk until we find out how much data we have,
+    * which means we need to run the compressor first and save the
+    * output.  This shouldn't be a problem, as the vast majority of
+    * comments should be reasonable, but we will set up an array of
+    * malloc'd pointers to be sure.
+    *
+    * If we knew the application was well behaved, we could simplify this
+    * greatly by assuming we can always malloc an output buffer large
+    * enough to hold the compressed text ((1001 * text_len / 1000) + 12)
+    * and malloc this directly.  The only time this would be a bad idea is
+    * if we can't malloc more than 64K and we have 64K of random input
+    * data, or if the input string is incredibly large (although this
+    * wouldn't cause a failure, just a slowdown due to swapping).
+    */
+   png_zlib_claim(png_ptr, PNG_ZLIB_FOR_TEXT);
+   /* Set up the compression buffers */
+   /* TODO: the following cast hides a potential overflow problem. */
+   png_ptr->zstream.avail_in = (uInt)text_len;
+   /* NOTE: assume zlib doesn't overwrite the input */
+   png_ptr->zstream.next_in = (Bytef *)text;
+   png_ptr->zstream.avail_out = png_ptr->zbuf_size;
+   png_ptr->zstream.next_out = png_ptr->zbuf;
+   /* This is the same compression loop as in png_write_row() */
+   do
+   {
+      /* Compress the data */
+      ret = deflate(&png_ptr->zstream, Z_NO_FLUSH);
+      if (ret != Z_OK)
+      {
+         /* Error */
+         if (png_ptr->zstream.msg != NULL)
+            png_error(png_ptr, png_ptr->zstream.msg);
+         else
+            png_error(png_ptr, "zlib error");
+      }
+      /* Check to see if we need more room */
+      if (!(png_ptr->zstream.avail_out))
+      {
+         /* Make sure the output array has room */
+         if (comp->num_output_ptr >= comp->max_output_ptr)
+         {
+            int old_max;
+            old_max = comp->max_output_ptr;
+            comp->max_output_ptr = comp->num_output_ptr + 4;
+            if (comp->output_ptr != NULL)
+            {
+               png_bytepp old_ptr;
+               old_ptr = comp->output_ptr;
+               comp->output_ptr = (png_bytepp)png_malloc(png_ptr,
+                   (png_alloc_size_t)
+                   (comp->max_output_ptr * png_sizeof(png_charpp)));
+               png_memcpy(comp->output_ptr, old_ptr, old_max
+                   * png_sizeof(png_charp));
+               png_free(png_ptr, old_ptr);
+            }
+            else
+               comp->output_ptr = (png_bytepp)png_malloc(png_ptr,
+                   (png_alloc_size_t)
+                   (comp->max_output_ptr * png_sizeof(png_charp)));
+         }
+         /* Save the data */
+         comp->output_ptr[comp->num_output_ptr] =
+             (png_bytep)png_malloc(png_ptr,
+             (png_alloc_size_t)png_ptr->zbuf_size);
+         png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf,
+             png_ptr->zbuf_size);
+         comp->num_output_ptr++;
+         /* and reset the buffer */
+         png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
+         png_ptr->zstream.next_out = png_ptr->zbuf;
+      }
+   /* Continue until we don't have any more to compress */
+   } while (png_ptr->zstream.avail_in);
+   /* Finish the compression */
+   do
+   {
+      /* Tell zlib we are finished */
+      ret = deflate(&png_ptr->zstream, Z_FINISH);
+      if (ret == Z_OK)
+      {
+         /* Check to see if we need more room */
+         if (!(png_ptr->zstream.avail_out))
+         {
+            /* Check to make sure our output array has room */
+            if (comp->num_output_ptr >= comp->max_output_ptr)
+            {
+               int old_max;
+               old_max = comp->max_output_ptr;
+               comp->max_output_ptr = comp->num_output_ptr + 4;
+               if (comp->output_ptr != NULL)
+               {
+                  png_bytepp old_ptr;
+                  old_ptr = comp->output_ptr;
+                  /* This could be optimized to realloc() */
+                  comp->output_ptr = (png_bytepp)png_malloc(png_ptr,
+                      (png_alloc_size_t)(comp->max_output_ptr *
+                      png_sizeof(png_charp)));
+                  png_memcpy(comp->output_ptr, old_ptr,
+                      old_max * png_sizeof(png_charp));
+                  png_free(png_ptr, old_ptr);
+               }
+               else
+                  comp->output_ptr = (png_bytepp)png_malloc(png_ptr,
+                      (png_alloc_size_t)(comp->max_output_ptr *
+                      png_sizeof(png_charp)));
+            }
+            /* Save the data */
+            comp->output_ptr[comp->num_output_ptr] =
+                (png_bytep)png_malloc(png_ptr,
+                (png_alloc_size_t)png_ptr->zbuf_size);
+            png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf,
+                png_ptr->zbuf_size);
+            comp->num_output_ptr++;
+            /* and reset the buffer pointers */
+            png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
+            png_ptr->zstream.next_out = png_ptr->zbuf;
+         }
+      }
+      else if (ret != Z_STREAM_END)
+      {
+         /* We got an error */
+         if (png_ptr->zstream.msg != NULL)
+            png_error(png_ptr, png_ptr->zstream.msg);
+         else
+            png_error(png_ptr, "zlib error");
+      }
+   } while (ret != Z_STREAM_END);
+   /* Text length is number of buffers plus last buffer */
+   text_len = png_ptr->zbuf_size * comp->num_output_ptr;
+   if (png_ptr->zstream.avail_out < png_ptr->zbuf_size)
+      text_len += png_ptr->zbuf_size - (png_size_t)png_ptr->zstream.avail_out;
+   return((int)text_len);
+}
+/* Ship the compressed text out via chunk writes */
+static void /* PRIVATE */
+png_write_compressed_data_out(png_structp png_ptr, compression_state *comp)
+{
+   int i;
+   /* Handle the no-compression case */
+   if (comp->input)
+   {
+      png_write_chunk_data(png_ptr, comp->input, comp->input_len);
+      return;
+   }
+#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED
+   /* The zbuf_size test is because the code below doesn't work if zbuf_size is
+    * '1'; simply skip it to avoid memory overwrite.
+    */
+   if (comp->input_len >= 2 && comp->input_len < 16384 && png_ptr->zbuf_size > 1)
+   {
+      unsigned int z_cmf;  /* zlib compression method and flags */
+      /* Optimize the CMF field in the zlib stream.  This hack of the zlib
+       * stream is compliant to the stream specification.
+       */
+      if (comp->num_output_ptr)
+        z_cmf = comp->output_ptr[0][0];
+      else
+        z_cmf = png_ptr->zbuf[0];
+      if ((z_cmf & 0x0f) == 8 && (z_cmf & 0xf0) <= 0x70)
+      {
+         unsigned int z_cinfo;
+         unsigned int half_z_window_size;
+         png_size_t uncompressed_text_size = comp->input_len;
+         z_cinfo = z_cmf >> 4;
+         half_z_window_size = 1 << (z_cinfo + 7);
+         while (uncompressed_text_size <= half_z_window_size &&
+             half_z_window_size >= 256)
+         {
+            z_cinfo--;
+            half_z_window_size >>= 1;
+         }
+         z_cmf = (z_cmf & 0x0f) | (z_cinfo << 4);
+         if (comp->num_output_ptr)
+         {
+           if (comp->output_ptr[0][0] != z_cmf)
+           {
+              int tmp;
+              comp->output_ptr[0][0] = (png_byte)z_cmf;
+              tmp = comp->output_ptr[0][1] & 0xe0;
+              tmp += 0x1f - ((z_cmf << 8) + tmp) % 0x1f;
+              comp->output_ptr[0][1] = (png_byte)tmp;
+           }
+         }
+         else
+         {
+            int tmp;
+            png_ptr->zbuf[0] = (png_byte)z_cmf;
+            tmp = png_ptr->zbuf[1] & 0xe0;
+            tmp += 0x1f - ((z_cmf << 8) + tmp) % 0x1f;
+            png_ptr->zbuf[1] = (png_byte)tmp;
+         }
+      }
+      else
+         png_error(png_ptr,
+             "Invalid zlib compression method or flags in non-IDAT chunk");
+   }
+#endif /* PNG_WRITE_OPTIMIZE_CMF_SUPPORTED */
+   /* Write saved output buffers, if any */
+   for (i = 0; i < comp->num_output_ptr; i++)
+   {
+      png_write_chunk_data(png_ptr, comp->output_ptr[i],
+          (png_size_t)png_ptr->zbuf_size);
+      png_free(png_ptr, comp->output_ptr[i]);
+   }
+   if (comp->max_output_ptr != 0)
+      png_free(png_ptr, comp->output_ptr);
+   /* Write anything left in zbuf */
+   if (png_ptr->zstream.avail_out < (png_uint_32)png_ptr->zbuf_size)
+      png_write_chunk_data(png_ptr, png_ptr->zbuf,
+          (png_size_t)(png_ptr->zbuf_size - png_ptr->zstream.avail_out));
+   /* Reset zlib for another zTXt/iTXt or image data */
+   png_zlib_release(png_ptr);
+}
+#endif /* PNG_WRITE_COMPRESSED_TEXT_SUPPORTED */
+/* Write the IHDR chunk, and update the png_struct with the necessary
+ * information.  Note that the rest of this code depends upon this
+ * information being correct.
+ */
+void /* PRIVATE */
+png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height,
+    int bit_depth, int color_type, int compression_type, int filter_type,
+    int interlace_type)
+{
+   png_byte buf[13]; /* Buffer to store the IHDR info */
+   png_debug(1, "in png_write_IHDR");
+   /* Check that we have valid input data from the application info */
+   switch (color_type)
+   {
+      case PNG_COLOR_TYPE_GRAY:
+         switch (bit_depth)
+         {
+            case 1:
+            case 2:
+            case 4:
+            case 8:
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+            case 16:
+#endif
+               png_ptr->channels = 1; break;
+            default:
+               png_error(png_ptr,
+                   "Invalid bit depth for grayscale image");
+         }
+         break;
+      case PNG_COLOR_TYPE_RGB:
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+         if (bit_depth != 8 && bit_depth != 16)
+#else
+         if (bit_depth != 8)
+#endif
+            png_error(png_ptr, "Invalid bit depth for RGB image");
+         png_ptr->channels = 3;
+         break;
+      case PNG_COLOR_TYPE_PALETTE:
+         switch (bit_depth)
+         {
+            case 1:
+            case 2:
+            case 4:
+            case 8:
+               png_ptr->channels = 1;
+               break;
+            default:
+               png_error(png_ptr, "Invalid bit depth for paletted image");
+         }
+         break;
+      case PNG_COLOR_TYPE_GRAY_ALPHA:
+         if (bit_depth != 8 && bit_depth != 16)
+            png_error(png_ptr, "Invalid bit depth for grayscale+alpha image");
+         png_ptr->channels = 2;
+         break;
+      case PNG_COLOR_TYPE_RGB_ALPHA:
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+         if (bit_depth != 8 && bit_depth != 16)
+#else
+         if (bit_depth != 8)
+#endif
+            png_error(png_ptr, "Invalid bit depth for RGBA image");
+         png_ptr->channels = 4;
+         break;
+      default:
+         png_error(png_ptr, "Invalid image color type specified");
+   }
+   if (compression_type != PNG_COMPRESSION_TYPE_BASE)
+   {
+      png_warning(png_ptr, "Invalid compression type specified");
+      compression_type = PNG_COMPRESSION_TYPE_BASE;
+   }
+   /* Write filter_method 64 (intrapixel differencing) only if
+    * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
+    * 2. Libpng did not write a PNG signature (this filter_method is only
+    *    used in PNG datastreams that are embedded in MNG datastreams) and
+    * 3. The application called png_permit_mng_features with a mask that
+    *    included PNG_FLAG_MNG_FILTER_64 and
+    * 4. The filter_method is 64 and
+    * 5. The color_type is RGB or RGBA
+    */
+   if (
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+       !((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
+       ((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE) == 0) &&
+       (color_type == PNG_COLOR_TYPE_RGB ||
+        color_type == PNG_COLOR_TYPE_RGB_ALPHA) &&
+       (filter_type == PNG_INTRAPIXEL_DIFFERENCING)) &&
+#endif
+       filter_type != PNG_FILTER_TYPE_BASE)
+   {
+      png_warning(png_ptr, "Invalid filter type specified");
+      filter_type = PNG_FILTER_TYPE_BASE;
+   }
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+   if (interlace_type != PNG_INTERLACE_NONE &&
+       interlace_type != PNG_INTERLACE_ADAM7)
+   {
+      png_warning(png_ptr, "Invalid interlace type specified");
+      interlace_type = PNG_INTERLACE_ADAM7;
+   }
+#else
+   interlace_type=PNG_INTERLACE_NONE;
+#endif
+   /* Save the relevent information */
+   png_ptr->bit_depth = (png_byte)bit_depth;
+   png_ptr->color_type = (png_byte)color_type;
+   png_ptr->interlaced = (png_byte)interlace_type;
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+   png_ptr->filter_type = (png_byte)filter_type;
+#endif
+   png_ptr->compression_type = (png_byte)compression_type;
+   png_ptr->width = width;
+   png_ptr->height = height;
+   png_ptr->pixel_depth = (png_byte)(bit_depth * png_ptr->channels);
+   png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, width);
+   /* Set the usr info, so any transformations can modify it */
+   png_ptr->usr_width = png_ptr->width;
+   png_ptr->usr_bit_depth = png_ptr->bit_depth;
+   png_ptr->usr_channels = png_ptr->channels;
+   /* Pack the header information into the buffer */
+   png_save_uint_32(buf, width);
+   png_save_uint_32(buf + 4, height);
+   buf[8] = (png_byte)bit_depth;
+   buf[9] = (png_byte)color_type;
+   buf[10] = (png_byte)compression_type;
+   buf[11] = (png_byte)filter_type;
+   buf[12] = (png_byte)interlace_type;
+   /* Write the chunk */
+   png_write_complete_chunk(png_ptr, png_IHDR, buf, (png_size_t)13);
+   /* Initialize zlib with PNG info */
+   png_ptr->zstream.zalloc = png_zalloc;
+   png_ptr->zstream.zfree = png_zfree;
+   png_ptr->zstream.opaque = (voidpf)png_ptr;
+   if (!(png_ptr->do_filter))
+   {
+      if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE ||
+          png_ptr->bit_depth < 8)
+         png_ptr->do_filter = PNG_FILTER_NONE;
+      else
+         png_ptr->do_filter = PNG_ALL_FILTERS;
+   }
+   if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_STRATEGY))
+   {
+      if (png_ptr->do_filter != PNG_FILTER_NONE)
+         png_ptr->zlib_strategy = Z_FILTERED;
+      else
+         png_ptr->zlib_strategy = Z_DEFAULT_STRATEGY;
+   }
+   if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_LEVEL))
+      png_ptr->zlib_level = Z_DEFAULT_COMPRESSION;
+   if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL))
+      png_ptr->zlib_mem_level = 8;
+   if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS))
+      png_ptr->zlib_window_bits = 15;
+   if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_METHOD))
+      png_ptr->zlib_method = 8;
+#ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
+#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
+   if (!(png_ptr->flags & PNG_FLAG_ZTXT_CUSTOM_STRATEGY))
+      png_ptr->zlib_text_strategy = Z_DEFAULT_STRATEGY;
+   if (!(png_ptr->flags & PNG_FLAG_ZTXT_CUSTOM_LEVEL))
+      png_ptr->zlib_text_level = png_ptr->zlib_level;
+   if (!(png_ptr->flags & PNG_FLAG_ZTXT_CUSTOM_MEM_LEVEL))
+      png_ptr->zlib_text_mem_level = png_ptr->zlib_mem_level;
+   if (!(png_ptr->flags & PNG_FLAG_ZTXT_CUSTOM_WINDOW_BITS))
+      png_ptr->zlib_text_window_bits = png_ptr->zlib_window_bits;
+   if (!(png_ptr->flags & PNG_FLAG_ZTXT_CUSTOM_METHOD))
+      png_ptr->zlib_text_method = png_ptr->zlib_method;
+#else
+   png_ptr->zlib_text_strategy = Z_DEFAULT_STRATEGY;
+   png_ptr->zlib_text_level = png_ptr->zlib_level;
+   png_ptr->zlib_text_mem_level = png_ptr->zlib_mem_level;
+   png_ptr->zlib_text_window_bits = png_ptr->zlib_window_bits;
+   png_ptr->zlib_text_method = png_ptr->zlib_method;
+#endif /* PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED */
+#endif /* PNG_WRITE_COMPRESSED_TEXT_SUPPORTED */
+   /* Record that the compressor has not yet been initialized. */
+   png_ptr->zlib_state = PNG_ZLIB_UNINITIALIZED;
+   png_ptr->mode = PNG_HAVE_IHDR; /* not READY_FOR_ZTXT */
+}
+/* Write the palette.  We are careful not to trust png_color to be in the
+ * correct order for PNG, so people can redefine it to any convenient
+ * structure.
+ */
+void /* PRIVATE */
+png_write_PLTE(png_structp png_ptr, png_const_colorp palette,
+    png_uint_32 num_pal)
+{
+   png_uint_32 i;
+   png_const_colorp pal_ptr;
+   png_byte buf[3];
+   png_debug(1, "in png_write_PLTE");
+   if ((
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+       !(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) &&
+#endif
+       num_pal == 0) || num_pal > 256)
+   {
+      if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+      {
+         png_error(png_ptr, "Invalid number of colors in palette");
+      }
+      else
+      {
+         png_warning(png_ptr, "Invalid number of colors in palette");
+         return;
+      }
+   }
+   if (!(png_ptr->color_type&PNG_COLOR_MASK_COLOR))
+   {
+      png_warning(png_ptr,
+          "Ignoring request to write a PLTE chunk in grayscale PNG");
+      return;
+   }
+   png_ptr->num_palette = (png_uint_16)num_pal;
+   png_debug1(3, "num_palette = %d", png_ptr->num_palette);
+   png_write_chunk_header(png_ptr, png_PLTE, (png_uint_32)(num_pal * 3));
+#ifdef PNG_POINTER_INDEXING_SUPPORTED
+   for (i = 0, pal_ptr = palette; i < num_pal; i++, pal_ptr++)
+   {
+      buf[0] = pal_ptr->red;
+      buf[1] = pal_ptr->green;
+      buf[2] = pal_ptr->blue;
+      png_write_chunk_data(png_ptr, buf, (png_size_t)3);
+   }
+#else
+   /* This is a little slower but some buggy compilers need to do this
+    * instead
+    */
+   pal_ptr=palette;
+   for (i = 0; i < num_pal; i++)
+   {
+      buf[0] = pal_ptr[i].red;
+      buf[1] = pal_ptr[i].green;
+      buf[2] = pal_ptr[i].blue;
+      png_write_chunk_data(png_ptr, buf, (png_size_t)3);
+   }
+#endif
+   png_write_chunk_end(png_ptr);
+   png_ptr->mode |= PNG_HAVE_PLTE;
+}
+/* Write an IDAT chunk */
+void /* PRIVATE */
+png_write_IDAT(png_structp png_ptr, png_bytep data, png_size_t length)
+{
+   png_debug(1, "in png_write_IDAT");
+#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED
+   if (!(png_ptr->mode & PNG_HAVE_IDAT) &&
+       png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE)
+   {
+      /* Optimize the CMF field in the zlib stream.  This hack of the zlib
+       * stream is compliant to the stream specification.
+       */
+      unsigned int z_cmf = data[0];  /* zlib compression method and flags */
+      if ((z_cmf & 0x0f) == 8 && (z_cmf & 0xf0) <= 0x70)
+      {
+         /* Avoid memory underflows and multiplication overflows.
+          *
+          * The conditions below are practically always satisfied;
+          * however, they still must be checked.
+          */
+         if (length >= 2 &&
+             png_ptr->height < 16384 && png_ptr->width < 16384)
+         {
+            /* Compute the maximum possible length of the datastream */
+            /* Number of pixels, plus for each row a filter byte
+             * and possibly a padding byte, so increase the maximum
+             * size to account for these.
+             */
+            unsigned int z_cinfo;
+            unsigned int half_z_window_size;
+            png_uint_32 uncompressed_idat_size = png_ptr->height *
+                ((png_ptr->width *
+                png_ptr->channels * png_ptr->bit_depth + 15) >> 3);
+            /* If it's interlaced, each block of 8 rows is sent as up to
+             * 14 rows, i.e., 6 additional rows, each with a filter byte
+             * and possibly a padding byte
+             */
+            if (png_ptr->interlaced)
+               uncompressed_idat_size += ((png_ptr->height + 7)/8) *
+                   (png_ptr->bit_depth < 8 ? 12 : 6);
+            z_cinfo = z_cmf >> 4;
+            half_z_window_size = 1 << (z_cinfo + 7);
+            while (uncompressed_idat_size <= half_z_window_size &&
+                half_z_window_size >= 256)
+            {
+               z_cinfo--;
+               half_z_window_size >>= 1;
+            }
+            z_cmf = (z_cmf & 0x0f) | (z_cinfo << 4);
+            if (data[0] != z_cmf)
+            {
+               int tmp;
+               data[0] = (png_byte)z_cmf;
+               tmp = data[1] & 0xe0;
+               tmp += 0x1f - ((z_cmf << 8) + tmp) % 0x1f;
+               data[1] = (png_byte)tmp;
+            }
+         }
+      }
+      else
+         png_error(png_ptr,
+             "Invalid zlib compression method or flags in IDAT");
+   }
+#endif /* PNG_WRITE_OPTIMIZE_CMF_SUPPORTED */
+   png_write_complete_chunk(png_ptr, png_IDAT, data, length);
+   png_ptr->mode |= PNG_HAVE_IDAT;
+   /* Prior to 1.5.4 this code was replicated in every caller (except at the
+    * end, where it isn't technically necessary).  Since this function has
+    * flushed the data we can safely reset the zlib output buffer here.
+    */
+   png_ptr->zstream.next_out = png_ptr->zbuf;
+   png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
+}
+/* Write an IEND chunk */
+void /* PRIVATE */
+png_write_IEND(png_structp png_ptr)
+{
+   png_debug(1, "in png_write_IEND");
+   png_write_complete_chunk(png_ptr, png_IEND, NULL, (png_size_t)0);
+   png_ptr->mode |= PNG_HAVE_IEND;
+}
+#ifdef PNG_WRITE_gAMA_SUPPORTED
+/* Write a gAMA chunk */
+void /* PRIVATE */
+png_write_gAMA_fixed(png_structp png_ptr, png_fixed_point file_gamma)
+{
+   png_byte buf[4];
+   png_debug(1, "in png_write_gAMA");
+   /* file_gamma is saved in 1/100,000ths */
+   png_save_uint_32(buf, (png_uint_32)file_gamma);
+   png_write_complete_chunk(png_ptr, png_gAMA, buf, (png_size_t)4);
+}
+#endif
+#ifdef PNG_WRITE_sRGB_SUPPORTED
+/* Write a sRGB chunk */
+void /* PRIVATE */
+png_write_sRGB(png_structp png_ptr, int srgb_intent)
+{
+   png_byte buf[1];
+   png_debug(1, "in png_write_sRGB");
+   if (srgb_intent >= PNG_sRGB_INTENT_LAST)
+      png_warning(png_ptr,
+          "Invalid sRGB rendering intent specified");
+   buf[0]=(png_byte)srgb_intent;
+   png_write_complete_chunk(png_ptr, png_sRGB, buf, (png_size_t)1);
+}
+#endif
+#ifdef PNG_WRITE_iCCP_SUPPORTED
+/* Write an iCCP chunk */
+void /* PRIVATE */
+png_write_iCCP(png_structp png_ptr, png_const_charp name, int compression_type,
+    png_const_charp profile, int profile_len)
+{
+   png_size_t name_len;
+   png_charp new_name;
+   compression_state comp;
+   int embedded_profile_len = 0;
+   png_debug(1, "in png_write_iCCP");
+   comp.num_output_ptr = 0;
+   comp.max_output_ptr = 0;
+   comp.output_ptr = NULL;
+   comp.input = NULL;
+   comp.input_len = 0;
+   if ((name_len = png_check_keyword(png_ptr, name, &new_name)) == 0)
+      return;
+   if (compression_type != PNG_COMPRESSION_TYPE_BASE)
+      png_warning(png_ptr, "Unknown compression type in iCCP chunk");
+   if (profile == NULL)
+      profile_len = 0;
+   if (profile_len > 3)
+      embedded_profile_len =
+          ((*( (png_const_bytep)profile    ))<<24) |
+          ((*( (png_const_bytep)profile + 1))<<16) |
+          ((*( (png_const_bytep)profile + 2))<< 8) |
+          ((*( (png_const_bytep)profile + 3))    );
+   if (embedded_profile_len < 0)
+   {
+      png_warning(png_ptr,
+          "Embedded profile length in iCCP chunk is negative");
+      png_free(png_ptr, new_name);
+      return;
+   }
+   if (profile_len < embedded_profile_len)
+   {
+      png_warning(png_ptr,
+          "Embedded profile length too large in iCCP chunk");
+      png_free(png_ptr, new_name);
+      return;
+   }
+   if (profile_len > embedded_profile_len)
+   {
+      png_warning(png_ptr,
+          "Truncating profile to actual length in iCCP chunk");
+      profile_len = embedded_profile_len;
+   }
+   if (profile_len)
+      profile_len = png_text_compress(png_ptr, profile,
+          (png_size_t)profile_len, PNG_COMPRESSION_TYPE_BASE, &comp);
+   /* Make sure we include the NULL after the name and the compression type */
+   png_write_chunk_header(png_ptr, png_iCCP,
+       (png_uint_32)(name_len + profile_len + 2));
+   new_name[name_len + 1] = 0x00;
+   png_write_chunk_data(png_ptr, (png_bytep)new_name,
+       (png_size_t)(name_len + 2));
+   if (profile_len)
+   {
+      comp.input_len = profile_len;
+      png_write_compressed_data_out(png_ptr, &comp);
+   }
+   png_write_chunk_end(png_ptr);
+   png_free(png_ptr, new_name);
+}
+#endif
+#ifdef PNG_WRITE_sPLT_SUPPORTED
+/* Write a sPLT chunk */
+void /* PRIVATE */
+png_write_sPLT(png_structp png_ptr, png_const_sPLT_tp spalette)
+{
+   png_size_t name_len;
+   png_charp new_name;
+   png_byte entrybuf[10];
+   png_size_t entry_size = (spalette->depth == 8 ? 6 : 10);
+   png_size_t palette_size = entry_size * spalette->nentries;
+   png_sPLT_entryp ep;
+#ifndef PNG_POINTER_INDEXING_SUPPORTED
+   int i;
+#endif
+   png_debug(1, "in png_write_sPLT");
+   if ((name_len = png_check_keyword(png_ptr,spalette->name, &new_name))==0)
+      return;
+   /* Make sure we include the NULL after the name */
+   png_write_chunk_header(png_ptr, png_sPLT,
+       (png_uint_32)(name_len + 2 + palette_size));
+   png_write_chunk_data(png_ptr, (png_bytep)new_name,
+       (png_size_t)(name_len + 1));
+   png_write_chunk_data(png_ptr, &spalette->depth, (png_size_t)1);
+   /* Loop through each palette entry, writing appropriately */
+#ifdef PNG_POINTER_INDEXING_SUPPORTED
+   for (ep = spalette->entries; ep<spalette->entries + spalette->nentries; ep++)
+   {
+      if (spalette->depth == 8)
+      {
+         entrybuf[0] = (png_byte)ep->red;
+         entrybuf[1] = (png_byte)ep->green;
+         entrybuf[2] = (png_byte)ep->blue;
+         entrybuf[3] = (png_byte)ep->alpha;
+         png_save_uint_16(entrybuf + 4, ep->frequency);
+      }
+      else
+      {
+         png_save_uint_16(entrybuf + 0, ep->red);
+         png_save_uint_16(entrybuf + 2, ep->green);
+         png_save_uint_16(entrybuf + 4, ep->blue);
+         png_save_uint_16(entrybuf + 6, ep->alpha);
+         png_save_uint_16(entrybuf + 8, ep->frequency);
+      }
+      png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size);
+   }
+#else
+   ep=spalette->entries;
+   for (i = 0; i>spalette->nentries; i++)
+   {
+      if (spalette->depth == 8)
+      {
+         entrybuf[0] = (png_byte)ep[i].red;
+         entrybuf[1] = (png_byte)ep[i].green;
+         entrybuf[2] = (png_byte)ep[i].blue;
+         entrybuf[3] = (png_byte)ep[i].alpha;
+         png_save_uint_16(entrybuf + 4, ep[i].frequency);
+      }
+      else
+      {
+         png_save_uint_16(entrybuf + 0, ep[i].red);
+         png_save_uint_16(entrybuf + 2, ep[i].green);
+         png_save_uint_16(entrybuf + 4, ep[i].blue);
+         png_save_uint_16(entrybuf + 6, ep[i].alpha);
+         png_save_uint_16(entrybuf + 8, ep[i].frequency);
+      }
+      png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size);
+   }
+#endif
+   png_write_chunk_end(png_ptr);
+   png_free(png_ptr, new_name);
+}
+#endif
+#ifdef PNG_WRITE_sBIT_SUPPORTED
+/* Write the sBIT chunk */
+void /* PRIVATE */
+png_write_sBIT(png_structp png_ptr, png_const_color_8p sbit, int color_type)
+{
+   png_byte buf[4];
+   png_size_t size;
+   png_debug(1, "in png_write_sBIT");
+   /* Make sure we don't depend upon the order of PNG_COLOR_8 */
+   if (color_type & PNG_COLOR_MASK_COLOR)
+   {
+      png_byte maxbits;
+      maxbits = (png_byte)(color_type==PNG_COLOR_TYPE_PALETTE ? 8 :
+          png_ptr->usr_bit_depth);
+      if (sbit->red == 0 || sbit->red > maxbits ||
+          sbit->green == 0 || sbit->green > maxbits ||
+          sbit->blue == 0 || sbit->blue > maxbits)
+      {
+         png_warning(png_ptr, "Invalid sBIT depth specified");
+         return;
+      }
+      buf[0] = sbit->red;
+      buf[1] = sbit->green;
+      buf[2] = sbit->blue;
+      size = 3;
+   }
+   else
+   {
+      if (sbit->gray == 0 || sbit->gray > png_ptr->usr_bit_depth)
+      {
+         png_warning(png_ptr, "Invalid sBIT depth specified");
+         return;
+      }
+      buf[0] = sbit->gray;
+      size = 1;
+   }
+   if (color_type & PNG_COLOR_MASK_ALPHA)
+   {
+      if (sbit->alpha == 0 || sbit->alpha > png_ptr->usr_bit_depth)
+      {
+         png_warning(png_ptr, "Invalid sBIT depth specified");
+         return;
+      }
+      buf[size++] = sbit->alpha;
+   }
+   png_write_complete_chunk(png_ptr, png_sBIT, buf, size);
+}
+#endif
+#ifdef PNG_WRITE_cHRM_SUPPORTED
+/* Write the cHRM chunk */
+void /* PRIVATE */
+png_write_cHRM_fixed(png_structp png_ptr, png_fixed_point white_x,
+    png_fixed_point white_y, png_fixed_point red_x, png_fixed_point red_y,
+    png_fixed_point green_x, png_fixed_point green_y, png_fixed_point blue_x,
+    png_fixed_point blue_y)
+{
+   png_byte buf[32];
+   png_debug(1, "in png_write_cHRM");
+   /* Each value is saved in 1/100,000ths */
+#ifdef PNG_CHECK_cHRM_SUPPORTED
+   if (png_check_cHRM_fixed(png_ptr, white_x, white_y, red_x, red_y,
+       green_x, green_y, blue_x, blue_y))
+#endif
+   {
+      png_save_uint_32(buf, (png_uint_32)white_x);
+      png_save_uint_32(buf + 4, (png_uint_32)white_y);
+      png_save_uint_32(buf + 8, (png_uint_32)red_x);
+      png_save_uint_32(buf + 12, (png_uint_32)red_y);
+      png_save_uint_32(buf + 16, (png_uint_32)green_x);
+      png_save_uint_32(buf + 20, (png_uint_32)green_y);
+      png_save_uint_32(buf + 24, (png_uint_32)blue_x);
+      png_save_uint_32(buf + 28, (png_uint_32)blue_y);
+      png_write_complete_chunk(png_ptr, png_cHRM, buf, (png_size_t)32);
+   }
+}
+#endif
+#ifdef PNG_WRITE_tRNS_SUPPORTED
+/* Write the tRNS chunk */
+void /* PRIVATE */
+png_write_tRNS(png_structp png_ptr, png_const_bytep trans_alpha,
+    png_const_color_16p tran, int num_trans, int color_type)
+{
+   png_byte buf[6];
+   png_debug(1, "in png_write_tRNS");
+   if (color_type == PNG_COLOR_TYPE_PALETTE)
+   {
+      if (num_trans <= 0 || num_trans > (int)png_ptr->num_palette)
+      {
+         png_warning(png_ptr, "Invalid number of transparent colors specified");
+         return;
+      }
+      /* Write the chunk out as it is */
+      png_write_complete_chunk(png_ptr, png_tRNS, trans_alpha, (png_size_t)num_trans);
+   }
+   else if (color_type == PNG_COLOR_TYPE_GRAY)
+   {
+      /* One 16 bit value */
+      if (tran->gray >= (1 << png_ptr->bit_depth))
+      {
+         png_warning(png_ptr,
+             "Ignoring attempt to write tRNS chunk out-of-range for bit_depth");
+         return;
+      }
+      png_save_uint_16(buf, tran->gray);
+      png_write_complete_chunk(png_ptr, png_tRNS, buf, (png_size_t)2);
+   }
+   else if (color_type == PNG_COLOR_TYPE_RGB)
+   {
+      /* Three 16 bit values */
+      png_save_uint_16(buf, tran->red);
+      png_save_uint_16(buf + 2, tran->green);
+      png_save_uint_16(buf + 4, tran->blue);
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+      if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]))
+#else
+      if (buf[0] | buf[2] | buf[4])
+#endif
+      {
+         png_warning(png_ptr,
+           "Ignoring attempt to write 16-bit tRNS chunk when bit_depth is 8");
+         return;
+      }
+      png_write_complete_chunk(png_ptr, png_tRNS, buf, (png_size_t)6);
+   }
+   else
+   {
+      png_warning(png_ptr, "Can't write tRNS with an alpha channel");
+   }
+}
+#endif
+#ifdef PNG_WRITE_bKGD_SUPPORTED
+/* Write the background chunk */
+void /* PRIVATE */
+png_write_bKGD(png_structp png_ptr, png_const_color_16p back, int color_type)
+{
+   png_byte buf[6];
+   png_debug(1, "in png_write_bKGD");
+   if (color_type == PNG_COLOR_TYPE_PALETTE)
+   {
+      if (
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+          (png_ptr->num_palette ||
+          (!(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE))) &&
+#endif
+         back->index >= png_ptr->num_palette)
+      {
+         png_warning(png_ptr, "Invalid background palette index");
+         return;
+      }
+      buf[0] = back->index;
+      png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)1);
+   }
+   else if (color_type & PNG_COLOR_MASK_COLOR)
+   {
+      png_save_uint_16(buf, back->red);
+      png_save_uint_16(buf + 2, back->green);
+      png_save_uint_16(buf + 4, back->blue);
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+      if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]))
+#else
+      if (buf[0] | buf[2] | buf[4])
+#endif
+      {
+         png_warning(png_ptr,
+             "Ignoring attempt to write 16-bit bKGD chunk when bit_depth is 8");
+         return;
+      }
+      png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)6);
+   }
+   else
+   {
+      if (back->gray >= (1 << png_ptr->bit_depth))
+      {
+         png_warning(png_ptr,
+             "Ignoring attempt to write bKGD chunk out-of-range for bit_depth");
+         return;
+      }
+      png_save_uint_16(buf, back->gray);
+      png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)2);
+   }
+}
+#endif
+#ifdef PNG_WRITE_hIST_SUPPORTED
+/* Write the histogram */
+void /* PRIVATE */
+png_write_hIST(png_structp png_ptr, png_const_uint_16p hist, int num_hist)
+{
+   int i;
+   png_byte buf[3];
+   png_debug(1, "in png_write_hIST");
+   if (num_hist > (int)png_ptr->num_palette)
+   {
+      png_debug2(3, "num_hist = %d, num_palette = %d", num_hist,
+          png_ptr->num_palette);
+      png_warning(png_ptr, "Invalid number of histogram entries specified");
+      return;
+   }
+   png_write_chunk_header(png_ptr, png_hIST, (png_uint_32)(num_hist * 2));
+   for (i = 0; i < num_hist; i++)
+   {
+      png_save_uint_16(buf, hist[i]);
+      png_write_chunk_data(png_ptr, buf, (png_size_t)2);
+   }
+   png_write_chunk_end(png_ptr);
+}
+#endif
+#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \
+    defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
+/* Check that the tEXt or zTXt keyword is valid per PNG 1.0 specification,
+ * and if invalid, correct the keyword rather than discarding the entire
+ * chunk.  The PNG 1.0 specification requires keywords 1-79 characters in
+ * length, forbids leading or trailing whitespace, multiple internal spaces,
+ * and the non-break space (0x80) from ISO 8859-1.  Returns keyword length.
+ *
+ * The new_key is allocated to hold the corrected keyword and must be freed
+ * by the calling routine.  This avoids problems with trying to write to
+ * static keywords without having to have duplicate copies of the strings.
+ */
+png_size_t /* PRIVATE */
+png_check_keyword(png_structp png_ptr, png_const_charp key, png_charpp new_key)
+{
+   png_size_t key_len;
+   png_const_charp ikp;
+   png_charp kp, dp;
+   int kflag;
+   int kwarn=0;
+   png_debug(1, "in png_check_keyword");
+   *new_key = NULL;
+   if (key == NULL || (key_len = png_strlen(key)) == 0)
+   {
+      png_warning(png_ptr, "zero length keyword");
+      return ((png_size_t)0);
+   }
+   png_debug1(2, "Keyword to be checked is '%s'", key);
+   *new_key = (png_charp)png_malloc_warn(png_ptr, (png_uint_32)(key_len + 2));
+   if (*new_key == NULL)
+   {
+      png_warning(png_ptr, "Out of memory while procesing keyword");
+      return ((png_size_t)0);
+   }
+   /* Replace non-printing characters with a blank and print a warning */
+   for (ikp = key, dp = *new_key; *ikp != '\0'; ikp++, dp++)
+   {
+      if ((png_byte)*ikp < 0x20 ||
+         ((png_byte)*ikp > 0x7E && (png_byte)*ikp < 0xA1))
+      {
+         PNG_WARNING_PARAMETERS(p)
+         png_warning_parameter_unsigned(p, 1, PNG_NUMBER_FORMAT_02x,
+            (png_byte)*ikp);
+         png_formatted_warning(png_ptr, p, "invalid keyword character 0x@1");
+         *dp = ' ';
+      }
+      else
+      {
+         *dp = *ikp;
+      }
+   }
+   *dp = '\0';
+   /* Remove any trailing white space. */
+   kp = *new_key + key_len - 1;
+   if (*kp == ' ')
+   {
+      png_warning(png_ptr, "trailing spaces removed from keyword");
+      while (*kp == ' ')
+      {
+         *(kp--) = '\0';
+         key_len--;
+      }
+   }
+   /* Remove any leading white space. */
+   kp = *new_key;
+   if (*kp == ' ')
+   {
+      png_warning(png_ptr, "leading spaces removed from keyword");
+      while (*kp == ' ')
+      {
+         kp++;
+         key_len--;
+      }
+   }
+   png_debug1(2, "Checking for multiple internal spaces in '%s'", kp);
+   /* Remove multiple internal spaces. */
+   for (kflag = 0, dp = *new_key; *kp != '\0'; kp++)
+   {
+      if (*kp == ' ' && kflag == 0)
+      {
+         *(dp++) = *kp;
+         kflag = 1;
+      }
+      else if (*kp == ' ')
+      {
+         key_len--;
+         kwarn = 1;
+      }
+      else
+      {
+         *(dp++) = *kp;
+         kflag = 0;
+      }
+   }
+   *dp = '\0';
+   if (kwarn)
+      png_warning(png_ptr, "extra interior spaces removed from keyword");
+   if (key_len == 0)
+   {
+      png_free(png_ptr, *new_key);
+      png_warning(png_ptr, "Zero length keyword");
+   }
+   if (key_len > 79)
+   {
+      png_warning(png_ptr, "keyword length must be 1 - 79 characters");
+      (*new_key)[79] = '\0';
+      key_len = 79;
+   }
+   return (key_len);
+}
+#endif
+#ifdef PNG_WRITE_tEXt_SUPPORTED
+/* Write a tEXt chunk */
+void /* PRIVATE */
+png_write_tEXt(png_structp png_ptr, png_const_charp key, png_const_charp text,
+    png_size_t text_len)
+{
+   png_size_t key_len;
+   png_charp new_key;
+   png_debug(1, "in png_write_tEXt");
+   if ((key_len = png_check_keyword(png_ptr, key, &new_key))==0)
+      return;
+   if (text == NULL || *text == '\0')
+      text_len = 0;
+   else
+      text_len = png_strlen(text);
+   /* Make sure we include the 0 after the key */
+   png_write_chunk_header(png_ptr, png_tEXt,
+       (png_uint_32)(key_len + text_len + 1));
+   /*
+    * We leave it to the application to meet PNG-1.0 requirements on the
+    * contents of the text.  PNG-1.0 through PNG-1.2 discourage the use of
+    * any non-Latin-1 characters except for NEWLINE.  ISO PNG will forbid them.
+    * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.
+    */
+   png_write_chunk_data(png_ptr, (png_bytep)new_key,
+       (png_size_t)(key_len + 1));
+   if (text_len)
+      png_write_chunk_data(png_ptr, (png_const_bytep)text,
+          (png_size_t)text_len);
+   png_write_chunk_end(png_ptr);
+   png_free(png_ptr, new_key);
+}
+#endif
+#ifdef PNG_WRITE_zTXt_SUPPORTED
+/* Write a compressed text chunk */
+void /* PRIVATE */
+png_write_zTXt(png_structp png_ptr, png_const_charp key, png_const_charp text,
+    png_size_t text_len, int compression)
+{
+   png_size_t key_len;
+   png_byte buf;
+   png_charp new_key;
+   compression_state comp;
+   png_debug(1, "in png_write_zTXt");
+   comp.num_output_ptr = 0;
+   comp.max_output_ptr = 0;
+   comp.output_ptr = NULL;
+   comp.input = NULL;
+   comp.input_len = 0;
+   if ((key_len = png_check_keyword(png_ptr, key, &new_key)) == 0)
+   {
+      png_free(png_ptr, new_key);
+      return;
+   }
+   if (text == NULL || *text == '\0' || compression==PNG_TEXT_COMPRESSION_NONE)
+   {
+      png_write_tEXt(png_ptr, new_key, text, (png_size_t)0);
+      png_free(png_ptr, new_key);
+      return;
+   }
+   text_len = png_strlen(text);
+   /* Compute the compressed data; do it now for the length */
+   text_len = png_text_compress(png_ptr, text, text_len, compression,
+       &comp);
+   /* Write start of chunk */
+   png_write_chunk_header(png_ptr, png_zTXt,
+       (png_uint_32)(key_len+text_len + 2));
+   /* Write key */
+   png_write_chunk_data(png_ptr, (png_bytep)new_key,
+       (png_size_t)(key_len + 1));
+   png_free(png_ptr, new_key);
+   buf = (png_byte)compression;
+   /* Write compression */
+   png_write_chunk_data(png_ptr, &buf, (png_size_t)1);
+   /* Write the compressed data */
+   comp.input_len = text_len;
+   png_write_compressed_data_out(png_ptr, &comp);
+   /* Close the chunk */
+   png_write_chunk_end(png_ptr);
+}
+#endif
+#ifdef PNG_WRITE_iTXt_SUPPORTED
+/* Write an iTXt chunk */
+void /* PRIVATE */
+png_write_iTXt(png_structp png_ptr, int compression, png_const_charp key,
+    png_const_charp lang, png_const_charp lang_key, png_const_charp text)
+{
+   png_size_t lang_len, key_len, lang_key_len, text_len;
+   png_charp new_lang;
+   png_charp new_key = NULL;
+   png_byte cbuf[2];
+   compression_state comp;
+   png_debug(1, "in png_write_iTXt");
+   comp.num_output_ptr = 0;
+   comp.max_output_ptr = 0;
+   comp.output_ptr = NULL;
+   comp.input = NULL;
+   if ((key_len = png_check_keyword(png_ptr, key, &new_key)) == 0)
+      return;
+   if ((lang_len = png_check_keyword(png_ptr, lang, &new_lang)) == 0)
+   {
+      png_warning(png_ptr, "Empty language field in iTXt chunk");
+      new_lang = NULL;
+      lang_len = 0;
+   }
+   if (lang_key == NULL)
+      lang_key_len = 0;
+   else
+      lang_key_len = png_strlen(lang_key);
+   if (text == NULL)
+      text_len = 0;
+   else
+      text_len = png_strlen(text);
+   /* Compute the compressed data; do it now for the length */
+   text_len = png_text_compress(png_ptr, text, text_len, compression - 2,
+       &comp);
+   /* Make sure we include the compression flag, the compression byte,
+    * and the NULs after the key, lang, and lang_key parts
+    */
+   png_write_chunk_header(png_ptr, png_iTXt, (png_uint_32)(
+        5 /* comp byte, comp flag, terminators for key, lang and lang_key */
+        + key_len
+        + lang_len
+        + lang_key_len
+        + text_len));
+   /* We leave it to the application to meet PNG-1.0 requirements on the
+    * contents of the text.  PNG-1.0 through PNG-1.2 discourage the use of
+    * any non-Latin-1 characters except for NEWLINE.  ISO PNG will forbid them.
+    * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.
+    */
+   png_write_chunk_data(png_ptr, (png_bytep)new_key, (png_size_t)(key_len + 1));
+   /* Set the compression flag */
+   if (compression == PNG_ITXT_COMPRESSION_NONE ||
+       compression == PNG_TEXT_COMPRESSION_NONE)
+      cbuf[0] = 0;
+   else /* compression == PNG_ITXT_COMPRESSION_zTXt */
+      cbuf[0] = 1;
+   /* Set the compression method */
+   cbuf[1] = 0;
+   png_write_chunk_data(png_ptr, cbuf, (png_size_t)2);
+   cbuf[0] = 0;
+   png_write_chunk_data(png_ptr, (new_lang ? (png_const_bytep)new_lang : cbuf),
+       (png_size_t)(lang_len + 1));
+   png_write_chunk_data(png_ptr, (lang_key ? (png_const_bytep)lang_key : cbuf),
+       (png_size_t)(lang_key_len + 1));
+   png_write_compressed_data_out(png_ptr, &comp);
+   png_write_chunk_end(png_ptr);
+   png_free(png_ptr, new_key);
+   png_free(png_ptr, new_lang);
+}
+#endif
+#ifdef PNG_WRITE_oFFs_SUPPORTED
+/* Write the oFFs chunk */
+void /* PRIVATE */
+png_write_oFFs(png_structp png_ptr, png_int_32 x_offset, png_int_32 y_offset,
+    int unit_type)
+{
+   png_byte buf[9];
+   png_debug(1, "in png_write_oFFs");
+   if (unit_type >= PNG_OFFSET_LAST)
+      png_warning(png_ptr, "Unrecognized unit type for oFFs chunk");
+   png_save_int_32(buf, x_offset);
+   png_save_int_32(buf + 4, y_offset);
+   buf[8] = (png_byte)unit_type;
+   png_write_complete_chunk(png_ptr, png_oFFs, buf, (png_size_t)9);
+}
+#endif
+#ifdef PNG_WRITE_pCAL_SUPPORTED
+/* Write the pCAL chunk (described in the PNG extensions document) */
+void /* PRIVATE */
+png_write_pCAL(png_structp png_ptr, png_charp purpose, png_int_32 X0,
+    png_int_32 X1, int type, int nparams, png_const_charp units,
+    png_charpp params)
+{
+   png_size_t purpose_len, units_len, total_len;
+   png_size_tp params_len;
+   png_byte buf[10];
+   png_charp new_purpose;
+   int i;
+   png_debug1(1, "in png_write_pCAL (%d parameters)", nparams);
+   if (type >= PNG_EQUATION_LAST)
+      png_warning(png_ptr, "Unrecognized equation type for pCAL chunk");
+   purpose_len = png_check_keyword(png_ptr, purpose, &new_purpose) + 1;
+   png_debug1(3, "pCAL purpose length = %d", (int)purpose_len);
+   units_len = png_strlen(units) + (nparams == 0 ? 0 : 1);
+   png_debug1(3, "pCAL units length = %d", (int)units_len);
+   total_len = purpose_len + units_len + 10;
+   params_len = (png_size_tp)png_malloc(png_ptr,
+       (png_alloc_size_t)(nparams * png_sizeof(png_size_t)));
+   /* Find the length of each parameter, making sure we don't count the
+    * null terminator for the last parameter.
+    */
+   for (i = 0; i < nparams; i++)
+   {
+      params_len[i] = png_strlen(params[i]) + (i == nparams - 1 ? 0 : 1);
+      png_debug2(3, "pCAL parameter %d length = %lu", i,
+          (unsigned long)params_len[i]);
+      total_len += params_len[i];
+   }
+   png_debug1(3, "pCAL total length = %d", (int)total_len);
+   png_write_chunk_header(png_ptr, png_pCAL, (png_uint_32)total_len);
+   png_write_chunk_data(png_ptr, (png_const_bytep)new_purpose, purpose_len);
+   png_save_int_32(buf, X0);
+   png_save_int_32(buf + 4, X1);
+   buf[8] = (png_byte)type;
+   buf[9] = (png_byte)nparams;
+   png_write_chunk_data(png_ptr, buf, (png_size_t)10);
+   png_write_chunk_data(png_ptr, (png_const_bytep)units, (png_size_t)units_len);
+   png_free(png_ptr, new_purpose);
+   for (i = 0; i < nparams; i++)
+   {
+      png_write_chunk_data(png_ptr, (png_const_bytep)params[i], params_len[i]);
+   }
+   png_free(png_ptr, params_len);
+   png_write_chunk_end(png_ptr);
+}
+#endif
+#ifdef PNG_WRITE_sCAL_SUPPORTED
+/* Write the sCAL chunk */
+void /* PRIVATE */
+png_write_sCAL_s(png_structp png_ptr, int unit, png_const_charp width,
+    png_const_charp height)
+{
+   png_byte buf[64];
+   png_size_t wlen, hlen, total_len;
+   png_debug(1, "in png_write_sCAL_s");
+   wlen = png_strlen(width);
+   hlen = png_strlen(height);
+   total_len = wlen + hlen + 2;
+   if (total_len > 64)
+   {
+      png_warning(png_ptr, "Can't write sCAL (buffer too small)");
+      return;
+   }
+   buf[0] = (png_byte)unit;
+   png_memcpy(buf + 1, width, wlen + 1);      /* Append the '\0' here */
+   png_memcpy(buf + wlen + 2, height, hlen);  /* Do NOT append the '\0' here */
+   png_debug1(3, "sCAL total length = %u", (unsigned int)total_len);
+   png_write_complete_chunk(png_ptr, png_sCAL, buf, total_len);
+}
+#endif
+#ifdef PNG_WRITE_pHYs_SUPPORTED
+/* Write the pHYs chunk */
+void /* PRIVATE */
+png_write_pHYs(png_structp png_ptr, png_uint_32 x_pixels_per_unit,
+    png_uint_32 y_pixels_per_unit,
+    int unit_type)
+{
+   png_byte buf[9];
+   png_debug(1, "in png_write_pHYs");
+   if (unit_type >= PNG_RESOLUTION_LAST)
+      png_warning(png_ptr, "Unrecognized unit type for pHYs chunk");
+   png_save_uint_32(buf, x_pixels_per_unit);
+   png_save_uint_32(buf + 4, y_pixels_per_unit);
+   buf[8] = (png_byte)unit_type;
+   png_write_complete_chunk(png_ptr, png_pHYs, buf, (png_size_t)9);
+}
+#endif
+#ifdef PNG_WRITE_tIME_SUPPORTED
+/* Write the tIME chunk.  Use either png_convert_from_struct_tm()
+ * or png_convert_from_time_t(), or fill in the structure yourself.
+ */
+void /* PRIVATE */
+png_write_tIME(png_structp png_ptr, png_const_timep mod_time)
+{
+   png_byte buf[7];
+   png_debug(1, "in png_write_tIME");
+   if (mod_time->month  > 12 || mod_time->month  < 1 ||
+       mod_time->day    > 31 || mod_time->day    < 1 ||
+       mod_time->hour   > 23 || mod_time->second > 60)
+   {
+      png_warning(png_ptr, "Invalid time specified for tIME chunk");
+      return;
+   }
+   png_save_uint_16(buf, mod_time->year);
+   buf[2] = mod_time->month;
+   buf[3] = mod_time->day;
+   buf[4] = mod_time->hour;
+   buf[5] = mod_time->minute;
+   buf[6] = mod_time->second;
+   png_write_complete_chunk(png_ptr, png_tIME, buf, (png_size_t)7);
+}
+#endif
+/* Initializes the row writing capability of libpng */
+void /* PRIVATE */
+png_write_start_row(png_structp png_ptr)
+{
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+   /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+   /* Start of interlace block */
+   static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
+   /* Offset to next interlace block */
+   static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+   /* Start of interlace block in the y direction */
+   static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
+   /* Offset to next interlace block in the y direction */
+   static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
+#endif
+   png_alloc_size_t buf_size;
+   int usr_pixel_depth;
+   png_debug(1, "in png_write_start_row");
+   usr_pixel_depth = png_ptr->usr_channels * png_ptr->usr_bit_depth;
+   buf_size = PNG_ROWBYTES(usr_pixel_depth, png_ptr->width) + 1;
+   /* 1.5.6: added to allow checking in the row write code. */
+   png_ptr->transformed_pixel_depth = png_ptr->pixel_depth;
+   png_ptr->maximum_pixel_depth = (png_byte)usr_pixel_depth;
+   /* Set up row buffer */
+   png_ptr->row_buf = (png_bytep)png_malloc(png_ptr, buf_size);
+   png_ptr->row_buf[0] = PNG_FILTER_VALUE_NONE;
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+   /* Set up filtering buffer, if using this filter */
+   if (png_ptr->do_filter & PNG_FILTER_SUB)
+   {
+      png_ptr->sub_row = (png_bytep)png_malloc(png_ptr, png_ptr->rowbytes + 1);
+      png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;
+   }
+   /* We only need to keep the previous row if we are using one of these. */
+   if (png_ptr->do_filter & (PNG_FILTER_AVG | PNG_FILTER_UP | PNG_FILTER_PAETH))
+   {
+      /* Set up previous row buffer */
+      png_ptr->prev_row = (png_bytep)png_calloc(png_ptr, buf_size);
+      if (png_ptr->do_filter & PNG_FILTER_UP)
+      {
+         png_ptr->up_row = (png_bytep)png_malloc(png_ptr,
+            png_ptr->rowbytes + 1);
+         png_ptr->up_row[0] = PNG_FILTER_VALUE_UP;
+      }
+      if (png_ptr->do_filter & PNG_FILTER_AVG)
+      {
+         png_ptr->avg_row = (png_bytep)png_malloc(png_ptr,
+             png_ptr->rowbytes + 1);
+         png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG;
+      }
+      if (png_ptr->do_filter & PNG_FILTER_PAETH)
+      {
+         png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr,
+             png_ptr->rowbytes + 1);
+         png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH;
+      }
+   }
+#endif /* PNG_WRITE_FILTER_SUPPORTED */
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+   /* If interlaced, we need to set up width and height of pass */
+   if (png_ptr->interlaced)
+   {
+      if (!(png_ptr->transformations & PNG_INTERLACE))
+      {
+         png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 -
+             png_pass_ystart[0]) / png_pass_yinc[0];
+         png_ptr->usr_width = (png_ptr->width + png_pass_inc[0] - 1 -
+             png_pass_start[0]) / png_pass_inc[0];
+      }
+      else
+      {
+         png_ptr->num_rows = png_ptr->height;
+         png_ptr->usr_width = png_ptr->width;
+      }
+   }
+   else
+#endif
+   {
+      png_ptr->num_rows = png_ptr->height;
+      png_ptr->usr_width = png_ptr->width;
+   }
+   png_zlib_claim(png_ptr, PNG_ZLIB_FOR_IDAT);
+   png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
+   png_ptr->zstream.next_out = png_ptr->zbuf;
+}
+/* Internal use only.  Called when finished processing a row of data. */
+void /* PRIVATE */
+png_write_finish_row(png_structp png_ptr)
+{
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+   /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+   /* Start of interlace block */
+   static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
+   /* Offset to next interlace block */
+   static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+   /* Start of interlace block in the y direction */
+   static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
+   /* Offset to next interlace block in the y direction */
+   static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
+#endif
+   int ret;
+   png_debug(1, "in png_write_finish_row");
+   /* Next row */
+   png_ptr->row_number++;
+   /* See if we are done */
+   if (png_ptr->row_number < png_ptr->num_rows)
+      return;
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+   /* If interlaced, go to next pass */
+   if (png_ptr->interlaced)
+   {
+      png_ptr->row_number = 0;
+      if (png_ptr->transformations & PNG_INTERLACE)
+      {
+         png_ptr->pass++;
+      }
+      else
+      {
+         /* Loop until we find a non-zero width or height pass */
+         do
+         {
+            png_ptr->pass++;
+            if (png_ptr->pass >= 7)
+               break;
+            png_ptr->usr_width = (png_ptr->width +
+                png_pass_inc[png_ptr->pass] - 1 -
+                png_pass_start[png_ptr->pass]) /
+                png_pass_inc[png_ptr->pass];
+            png_ptr->num_rows = (png_ptr->height +
+                png_pass_yinc[png_ptr->pass] - 1 -
+                png_pass_ystart[png_ptr->pass]) /
+                png_pass_yinc[png_ptr->pass];
+            if (png_ptr->transformations & PNG_INTERLACE)
+               break;
+         } while (png_ptr->usr_width == 0 || png_ptr->num_rows == 0);
+      }
+      /* Reset the row above the image for the next pass */
+      if (png_ptr->pass < 7)
+      {
+         if (png_ptr->prev_row != NULL)
+            png_memset(png_ptr->prev_row, 0,
+                (png_size_t)(PNG_ROWBYTES(png_ptr->usr_channels*
+                png_ptr->usr_bit_depth, png_ptr->width)) + 1);
+         return;
+      }
+   }
+#endif
+   /* If we get here, we've just written the last row, so we need
+      to flush the compressor */
+   do
+   {
+      /* Tell the compressor we are done */
+      ret = deflate(&png_ptr->zstream, Z_FINISH);
+      /* Check for an error */
+      if (ret == Z_OK)
+      {
+         /* Check to see if we need more room */
+         if (!(png_ptr->zstream.avail_out))
+         {
+            png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
+            png_ptr->zstream.next_out = png_ptr->zbuf;
+            png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
+         }
+      }
+      else if (ret != Z_STREAM_END)
+      {
+         if (png_ptr->zstream.msg != NULL)
+            png_error(png_ptr, png_ptr->zstream.msg);
+         else
+            png_error(png_ptr, "zlib error");
+      }
+   } while (ret != Z_STREAM_END);
+   /* Write any extra space */
+   if (png_ptr->zstream.avail_out < png_ptr->zbuf_size)
+   {
+      png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size -
+          png_ptr->zstream.avail_out);
+   }
+   png_zlib_release(png_ptr);
+   png_ptr->zstream.data_type = Z_BINARY;
+}
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+/* Pick out the correct pixels for the interlace pass.
+ * The basic idea here is to go through the row with a source
+ * pointer and a destination pointer (sp and dp), and copy the
+ * correct pixels for the pass.  As the row gets compacted,
+ * sp will always be >= dp, so we should never overwrite anything.
+ * See the default: case for the easiest code to understand.
+ */
+void /* PRIVATE */
+png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass)
+{
+   /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+   /* Start of interlace block */
+   static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
+   /* Offset to next interlace block */
+   static PNG_CONST png_byte  png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+   png_debug(1, "in png_do_write_interlace");
+   /* We don't have to do anything on the last pass (6) */
+   if (pass < 6)
+   {
+      /* Each pixel depth is handled separately */
+      switch (row_info->pixel_depth)
+      {
+         case 1:
+         {
+            png_bytep sp;
+            png_bytep dp;
+            int shift;
+            int d;
+            int value;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+            dp = row;
+            d = 0;
+            shift = 7;
+            for (i = png_pass_start[pass]; i < row_width;
+               i += png_pass_inc[pass])
+            {
+               sp = row + (png_size_t)(i >> 3);
+               value = (int)(*sp >> (7 - (int)(i & 0x07))) & 0x01;
+               d |= (value << shift);
+               if (shift == 0)
+               {
+                  shift = 7;
+                  *dp++ = (png_byte)d;
+                  d = 0;
+               }
+               else
+                  shift--;
+            }
+            if (shift != 7)
+               *dp = (png_byte)d;
+            break;
+         }
+         case 2:
+         {
+            png_bytep sp;
+            png_bytep dp;
+            int shift;
+            int d;
+            int value;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+            dp = row;
+            shift = 6;
+            d = 0;
+            for (i = png_pass_start[pass]; i < row_width;
+               i += png_pass_inc[pass])
+            {
+               sp = row + (png_size_t)(i >> 2);
+               value = (*sp >> ((3 - (int)(i & 0x03)) << 1)) & 0x03;
+               d |= (value << shift);
+               if (shift == 0)
+               {
+                  shift = 6;
+                  *dp++ = (png_byte)d;
+                  d = 0;
+               }
+               else
+                  shift -= 2;
+            }
+            if (shift != 6)
+               *dp = (png_byte)d;
+            break;
+         }
+         case 4:
+         {
+            png_bytep sp;
+            png_bytep dp;
+            int shift;
+            int d;
+            int value;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+            dp = row;
+            shift = 4;
+            d = 0;
+            for (i = png_pass_start[pass]; i < row_width;
+                i += png_pass_inc[pass])
+            {
+               sp = row + (png_size_t)(i >> 1);
+               value = (*sp >> ((1 - (int)(i & 0x01)) << 2)) & 0x0f;
+               d |= (value << shift);
+               if (shift == 0)
+               {
+                  shift = 4;
+                  *dp++ = (png_byte)d;
+                  d = 0;
+               }
+               else
+                  shift -= 4;
+            }
+            if (shift != 4)
+               *dp = (png_byte)d;
+            break;
+         }
+         default:
+         {
+            png_bytep sp;
+            png_bytep dp;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+            png_size_t pixel_bytes;
+            /* Start at the beginning */
+            dp = row;
+            /* Find out how many bytes each pixel takes up */
+            pixel_bytes = (row_info->pixel_depth >> 3);
+            /* Loop through the row, only looking at the pixels that matter */
+            for (i = png_pass_start[pass]; i < row_width;
+               i += png_pass_inc[pass])
+            {
+               /* Find out where the original pixel is */
+               sp = row + (png_size_t)i * pixel_bytes;
+               /* Move the pixel */
+               if (dp != sp)
+                  png_memcpy(dp, sp, pixel_bytes);
+               /* Next pixel */
+               dp += pixel_bytes;
+            }
+            break;
+         }
+      }
+      /* Set new row width */
+      row_info->width = (row_info->width +
+          png_pass_inc[pass] - 1 -
+          png_pass_start[pass]) /
+          png_pass_inc[pass];
+      row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
+          row_info->width);
+   }
+}
+#endif
+/* This filters the row, chooses which filter to use, if it has not already
+ * been specified by the application, and then writes the row out with the
+ * chosen filter.
+ */
+static void png_write_filtered_row(png_structp png_ptr, png_bytep filtered_row,
+   png_size_t row_bytes);
+#define PNG_MAXSUM (((png_uint_32)(-1)) >> 1)
+#define PNG_HISHIFT 10
+#define PNG_LOMASK ((png_uint_32)0xffffL)
+#define PNG_HIMASK ((png_uint_32)(~PNG_LOMASK >> PNG_HISHIFT))
+void /* PRIVATE */
+png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
+{
+   png_bytep best_row;
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+   png_bytep prev_row, row_buf;
+   png_uint_32 mins, bpp;
+   png_byte filter_to_do = png_ptr->do_filter;
+   png_size_t row_bytes = row_info->rowbytes;
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+   int num_p_filters = png_ptr->num_prev_filters;
+#endif
+   png_debug(1, "in png_write_find_filter");
+#ifndef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+  if (png_ptr->row_number == 0 && filter_to_do == PNG_ALL_FILTERS)
+  {
+     /* These will never be selected so we need not test them. */
+     filter_to_do &= ~(PNG_FILTER_UP | PNG_FILTER_PAETH);
+  }
+#endif
+   /* Find out how many bytes offset each pixel is */
+   bpp = (row_info->pixel_depth + 7) >> 3;
+   prev_row = png_ptr->prev_row;
+#endif
+   best_row = png_ptr->row_buf;
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+   row_buf = best_row;
+   mins = PNG_MAXSUM;
+   /* The prediction method we use is to find which method provides the
+    * smallest value when summing the absolute values of the distances
+    * from zero, using anything >= 128 as negative numbers.  This is known
+    * as the "minimum sum of absolute differences" heuristic.  Other
+    * heuristics are the "weighted minimum sum of absolute differences"
+    * (experimental and can in theory improve compression), and the "zlib
+    * predictive" method (not implemented yet), which does test compressions
+    * of lines using different filter methods, and then chooses the
+    * (series of) filter(s) that give minimum compressed data size (VERY
+    * computationally expensive).
+    *
+    * GRR 980525:  consider also
+    *
+    *   (1) minimum sum of absolute differences from running average (i.e.,
+    *       keep running sum of non-absolute differences & count of bytes)
+    *       [track dispersion, too?  restart average if dispersion too large?]
+    *
+    *  (1b) minimum sum of absolute differences from sliding average, probably
+    *       with window size <= deflate window (usually 32K)
+    *
+    *   (2) minimum sum of squared differences from zero or running average
+    *       (i.e., ~ root-mean-square approach)
+    */
+   /* We don't need to test the 'no filter' case if this is the only filter
+    * that has been chosen, as it doesn't actually do anything to the data.
+    */
+   if ((filter_to_do & PNG_FILTER_NONE) && filter_to_do != PNG_FILTER_NONE)
+   {
+      png_bytep rp;
+      png_uint_32 sum = 0;
+      png_size_t i;
+      int v;
+      for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++)
+      {
+         v = *rp;
+         sum += (v < 128) ? v : 256 - v;
+      }
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+      if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
+      {
+         png_uint_32 sumhi, sumlo;
+         int j;
+         sumlo = sum & PNG_LOMASK;
+         sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; /* Gives us some footroom */
+         /* Reduce the sum if we match any of the previous rows */
+         for (j = 0; j < num_p_filters; j++)
+         {
+            if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE)
+            {
+               sumlo = (sumlo * png_ptr->filter_weights[j]) >>
+                   PNG_WEIGHT_SHIFT;
+               sumhi = (sumhi * png_ptr->filter_weights[j]) >>
+                   PNG_WEIGHT_SHIFT;
+            }
+         }
+         /* Factor in the cost of this filter (this is here for completeness,
+          * but it makes no sense to have a "cost" for the NONE filter, as
+          * it has the minimum possible computational cost - none).
+          */
+         sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >>
+             PNG_COST_SHIFT;
+         sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >>
+             PNG_COST_SHIFT;
+         if (sumhi > PNG_HIMASK)
+            sum = PNG_MAXSUM;
+         else
+            sum = (sumhi << PNG_HISHIFT) + sumlo;
+      }
+#endif
+      mins = sum;
+   }
+   /* Sub filter */
+   if (filter_to_do == PNG_FILTER_SUB)
+   /* It's the only filter so no testing is needed */
+   {
+      png_bytep rp, lp, dp;
+      png_size_t i;
+      for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp;
+           i++, rp++, dp++)
+      {
+         *dp = *rp;
+      }
+      for (lp = row_buf + 1; i < row_bytes;
+         i++, rp++, lp++, dp++)
+      {
+         *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);
+      }
+      best_row = png_ptr->sub_row;
+   }
+   else if (filter_to_do & PNG_FILTER_SUB)
+   {
+      png_bytep rp, dp, lp;
+      png_uint_32 sum = 0, lmins = mins;
+      png_size_t i;
+      int v;
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+      /* We temporarily increase the "minimum sum" by the factor we
+       * would reduce the sum of this filter, so that we can do the
+       * early exit comparison without scaling the sum each time.
+       */
+      if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
+      {
+         int j;
+         png_uint_32 lmhi, lmlo;
+         lmlo = lmins & PNG_LOMASK;
+         lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
+         for (j = 0; j < num_p_filters; j++)
+         {
+            if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB)
+            {
+               lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
+                   PNG_WEIGHT_SHIFT;
+               lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
+                   PNG_WEIGHT_SHIFT;
+            }
+         }
+         lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
+             PNG_COST_SHIFT;
+         lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
+             PNG_COST_SHIFT;
+         if (lmhi > PNG_HIMASK)
+            lmins = PNG_MAXSUM;
+         else
+            lmins = (lmhi << PNG_HISHIFT) + lmlo;
+      }
+#endif
+      for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp;
+           i++, rp++, dp++)
+      {
+         v = *dp = *rp;
+         sum += (v < 128) ? v : 256 - v;
+      }
+      for (lp = row_buf + 1; i < row_bytes;
+         i++, rp++, lp++, dp++)
+      {
+         v = *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);
+         sum += (v < 128) ? v : 256 - v;
+         if (sum > lmins)  /* We are already worse, don't continue. */
+            break;
+      }
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+      if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
+      {
+         int j;
+         png_uint_32 sumhi, sumlo;
+         sumlo = sum & PNG_LOMASK;
+         sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
+         for (j = 0; j < num_p_filters; j++)
+         {
+            if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB)
+            {
+               sumlo = (sumlo * png_ptr->inv_filter_weights[j]) >>
+                   PNG_WEIGHT_SHIFT;
+               sumhi = (sumhi * png_ptr->inv_filter_weights[j]) >>
+                   PNG_WEIGHT_SHIFT;
+            }
+         }
+         sumlo = (sumlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
+             PNG_COST_SHIFT;
+         sumhi = (sumhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
+             PNG_COST_SHIFT;
+         if (sumhi > PNG_HIMASK)
+            sum = PNG_MAXSUM;
+         else
+            sum = (sumhi << PNG_HISHIFT) + sumlo;
+      }
+#endif
+      if (sum < mins)
+      {
+         mins = sum;
+         best_row = png_ptr->sub_row;
+      }
+   }
+   /* Up filter */
+   if (filter_to_do == PNG_FILTER_UP)
+   {
+      png_bytep rp, dp, pp;
+      png_size_t i;
+      for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1,
+          pp = prev_row + 1; i < row_bytes;
+          i++, rp++, pp++, dp++)
+      {
+         *dp = (png_byte)(((int)*rp - (int)*pp) & 0xff);
+      }
+      best_row = png_ptr->up_row;
+   }
+   else if (filter_to_do & PNG_FILTER_UP)
+   {
+      png_bytep rp, dp, pp;
+      png_uint_32 sum = 0, lmins = mins;
+      png_size_t i;
+      int v;
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+      if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
+      {
+         int j;
+         png_uint_32 lmhi, lmlo;
+         lmlo = lmins & PNG_LOMASK;
+         lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
+         for (j = 0; j < num_p_filters; j++)
+         {
+            if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP)
+            {
+               lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
+                   PNG_WEIGHT_SHIFT;
+               lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
+                   PNG_WEIGHT_SHIFT;
+            }
+         }
+         lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >>
+             PNG_COST_SHIFT;
+         lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >>
+             PNG_COST_SHIFT;
+         if (lmhi > PNG_HIMASK)
+            lmins = PNG_MAXSUM;
+         else
+            lmins = (lmhi << PNG_HISHIFT) + lmlo;
+      }
+#endif
+      for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1,
+          pp = prev_row + 1; i < row_bytes; i++)
+      {
+         v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
+         sum += (v < 128) ? v : 256 - v;
+         if (sum > lmins)  /* We are already worse, don't continue. */
+            break;
+      }
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+      if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
+      {
+         int j;
+         png_uint_32 sumhi, sumlo;
+         sumlo = sum & PNG_LOMASK;
+         sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
+         for (j = 0; j < num_p_filters; j++)
+         {
+            if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP)
+            {
+               sumlo = (sumlo * png_ptr->filter_weights[j]) >>
+                   PNG_WEIGHT_SHIFT;
+               sumhi = (sumhi * png_ptr->filter_weights[j]) >>
+                   PNG_WEIGHT_SHIFT;
+            }
+         }
+         sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >>
+             PNG_COST_SHIFT;
+         sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >>
+             PNG_COST_SHIFT;
+         if (sumhi > PNG_HIMASK)
+            sum = PNG_MAXSUM;
+         else
+            sum = (sumhi << PNG_HISHIFT) + sumlo;
+      }
+#endif
+      if (sum < mins)
+      {
+         mins = sum;
+         best_row = png_ptr->up_row;
+      }
+   }
+   /* Avg filter */
+   if (filter_to_do == PNG_FILTER_AVG)
+   {
+      png_bytep rp, dp, pp, lp;
+      png_uint_32 i;
+      for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1,
+           pp = prev_row + 1; i < bpp; i++)
+      {
+         *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);
+      }
+      for (lp = row_buf + 1; i < row_bytes; i++)
+      {
+         *dp++ = (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2))
+                 & 0xff);
+      }
+      best_row = png_ptr->avg_row;
+   }
+   else if (filter_to_do & PNG_FILTER_AVG)
+   {
+      png_bytep rp, dp, pp, lp;
+      png_uint_32 sum = 0, lmins = mins;
+      png_size_t i;
+      int v;
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+      if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
+      {
+         int j;
+         png_uint_32 lmhi, lmlo;
+         lmlo = lmins & PNG_LOMASK;
+         lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
+         for (j = 0; j < num_p_filters; j++)
+         {
+            if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_AVG)
+            {
+               lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
+                   PNG_WEIGHT_SHIFT;
+               lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
+                   PNG_WEIGHT_SHIFT;
+            }
+         }
+         lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >>
+             PNG_COST_SHIFT;
+         lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >>
+             PNG_COST_SHIFT;
+         if (lmhi > PNG_HIMASK)
+            lmins = PNG_MAXSUM;
+         else
+            lmins = (lmhi << PNG_HISHIFT) + lmlo;
+      }
+#endif
+      for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1,
+           pp = prev_row + 1; i < bpp; i++)
+      {
+         v = *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);
+         sum += (v < 128) ? v : 256 - v;
+      }
+      for (lp = row_buf + 1; i < row_bytes; i++)
+      {
+         v = *dp++ =
+             (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2)) & 0xff);
+         sum += (v < 128) ? v : 256 - v;
+         if (sum > lmins)  /* We are already worse, don't continue. */
+            break;
+      }
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+      if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
+      {
+         int j;
+         png_uint_32 sumhi, sumlo;
+         sumlo = sum & PNG_LOMASK;
+         sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
+         for (j = 0; j < num_p_filters; j++)
+         {
+            if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE)
+            {
+               sumlo = (sumlo * png_ptr->filter_weights[j]) >>
+                   PNG_WEIGHT_SHIFT;
+               sumhi = (sumhi * png_ptr->filter_weights[j]) >>
+                   PNG_WEIGHT_SHIFT;
+            }
+         }
+         sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >>
+             PNG_COST_SHIFT;
+         sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >>
+             PNG_COST_SHIFT;
+         if (sumhi > PNG_HIMASK)
+            sum = PNG_MAXSUM;
+         else
+            sum = (sumhi << PNG_HISHIFT) + sumlo;
+      }
+#endif
+      if (sum < mins)
+      {
+         mins = sum;
+         best_row = png_ptr->avg_row;
+      }
+   }
+   /* Paeth filter */
+   if (filter_to_do == PNG_FILTER_PAETH)
+   {
+      png_bytep rp, dp, pp, cp, lp;
+      png_size_t i;
+      for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1,
+          pp = prev_row + 1; i < bpp; i++)
+      {
+         *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
+      }
+      for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++)
+      {
+         int a, b, c, pa, pb, pc, p;
+         b = *pp++;
+         c = *cp++;
+         a = *lp++;
+         p = b - c;
+         pc = a - c;
+#ifdef PNG_USE_ABS
+         pa = abs(p);
+         pb = abs(pc);
+         pc = abs(p + pc);
+#else
+         pa = p < 0 ? -p : p;
+         pb = pc < 0 ? -pc : pc;
+         pc = (p + pc) < 0 ? -(p + pc) : p + pc;
+#endif
+         p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
+         *dp++ = (png_byte)(((int)*rp++ - p) & 0xff);
+      }
+      best_row = png_ptr->paeth_row;
+   }
+   else if (filter_to_do & PNG_FILTER_PAETH)
+   {
+      png_bytep rp, dp, pp, cp, lp;
+      png_uint_32 sum = 0, lmins = mins;
+      png_size_t i;
+      int v;
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+      if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
+      {
+         int j;
+         png_uint_32 lmhi, lmlo;
+         lmlo = lmins & PNG_LOMASK;
+         lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
+         for (j = 0; j < num_p_filters; j++)
+         {
+            if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH)
+            {
+               lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
+                   PNG_WEIGHT_SHIFT;
+               lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
+                   PNG_WEIGHT_SHIFT;
+            }
+         }
+         lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >>
+             PNG_COST_SHIFT;
+         lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >>
+             PNG_COST_SHIFT;
+         if (lmhi > PNG_HIMASK)
+            lmins = PNG_MAXSUM;
+         else
+            lmins = (lmhi << PNG_HISHIFT) + lmlo;
+      }
+#endif
+      for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1,
+          pp = prev_row + 1; i < bpp; i++)
+      {
+         v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
+         sum += (v < 128) ? v : 256 - v;
+      }
+      for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++)
+      {
+         int a, b, c, pa, pb, pc, p;
+         b = *pp++;
+         c = *cp++;
+         a = *lp++;
+#ifndef PNG_SLOW_PAETH
+         p = b - c;
+         pc = a - c;
+#ifdef PNG_USE_ABS
+         pa = abs(p);
+         pb = abs(pc);
+         pc = abs(p + pc);
+#else
+         pa = p < 0 ? -p : p;
+         pb = pc < 0 ? -pc : pc;
+         pc = (p + pc) < 0 ? -(p + pc) : p + pc;
+#endif
+         p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
+#else /* PNG_SLOW_PAETH */
+         p = a + b - c;
+         pa = abs(p - a);
+         pb = abs(p - b);
+         pc = abs(p - c);
+         if (pa <= pb && pa <= pc)
+            p = a;
+         else if (pb <= pc)
+            p = b;
+         else
+            p = c;
+#endif /* PNG_SLOW_PAETH */
+         v = *dp++ = (png_byte)(((int)*rp++ - p) & 0xff);
+         sum += (v < 128) ? v : 256 - v;
+         if (sum > lmins)  /* We are already worse, don't continue. */
+            break;
+      }
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+      if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
+      {
+         int j;
+         png_uint_32 sumhi, sumlo;
+         sumlo = sum & PNG_LOMASK;
+         sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
+         for (j = 0; j < num_p_filters; j++)
+         {
+            if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH)
+            {
+               sumlo = (sumlo * png_ptr->filter_weights[j]) >>
+                   PNG_WEIGHT_SHIFT;
+               sumhi = (sumhi * png_ptr->filter_weights[j]) >>
+                   PNG_WEIGHT_SHIFT;
+            }
+         }
+         sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >>
+             PNG_COST_SHIFT;
+         sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >>
+             PNG_COST_SHIFT;
+         if (sumhi > PNG_HIMASK)
+            sum = PNG_MAXSUM;
+         else
+            sum = (sumhi << PNG_HISHIFT) + sumlo;
+      }
+#endif
+      if (sum < mins)
+      {
+         best_row = png_ptr->paeth_row;
+      }
+   }
+#endif /* PNG_WRITE_FILTER_SUPPORTED */
+   /* Do the actual writing of the filtered row data from the chosen filter. */
+   png_write_filtered_row(png_ptr, best_row, row_info->rowbytes+1);
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+   /* Save the type of filter we picked this time for future calculations */
+   if (png_ptr->num_prev_filters > 0)
+   {
+      int j;
+      for (j = 1; j < num_p_filters; j++)
+      {
+         png_ptr->prev_filters[j] = png_ptr->prev_filters[j - 1];
+      }
+      png_ptr->prev_filters[j] = best_row[0];
+   }
+#endif
+#endif /* PNG_WRITE_FILTER_SUPPORTED */
+}
+/* Do the actual writing of a previously filtered row. */
+static void
+png_write_filtered_row(png_structp png_ptr, png_bytep filtered_row,
+   png_size_t avail/*includes filter byte*/)
+{
+   png_debug(1, "in png_write_filtered_row");
+   png_debug1(2, "filter = %d", filtered_row[0]);
+   /* Set up the zlib input buffer */
+   png_ptr->zstream.next_in = filtered_row;
+   png_ptr->zstream.avail_in = 0;
+   /* Repeat until we have compressed all the data */
+   do
+   {
+      int ret; /* Return of zlib */
+      /* Record the number of bytes available - zlib supports at least 65535
+       * bytes at one step, depending on the size of the zlib type 'uInt', the
+       * maximum size zlib can write at once is ZLIB_IO_MAX (from pngpriv.h).
+       * Use this because on 16 bit systems 'rowbytes' can be up to 65536 (i.e.
+       * one more than 16 bits) and, in this case 'rowbytes+1' can overflow a
+       * uInt.  ZLIB_IO_MAX can be safely reduced to cause zlib to be called
+       * with smaller chunks of data.
+       */
+      if (png_ptr->zstream.avail_in == 0)
+      {
+         if (avail > ZLIB_IO_MAX)
+         {
+            png_ptr->zstream.avail_in  = ZLIB_IO_MAX;
+            avail -= ZLIB_IO_MAX;
+         }
+         else
+         {
+            /* So this will fit in the available uInt space: */
+            png_ptr->zstream.avail_in = (uInt)avail;
+            avail = 0;
+         }
+      }
+      /* Compress the data */
+      ret = deflate(&png_ptr->zstream, Z_NO_FLUSH);
+      /* Check for compression errors */
+      if (ret != Z_OK)
+      {
+         if (png_ptr->zstream.msg != NULL)
+            png_error(png_ptr, png_ptr->zstream.msg);
+         else
+            png_error(png_ptr, "zlib error");
+      }
+      /* See if it is time to write another IDAT */
+      if (!(png_ptr->zstream.avail_out))
+      {
+         /* Write the IDAT and reset the zlib output buffer */
+         png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
+      }
+   /* Repeat until all data has been compressed */
+   } while (avail > 0 || png_ptr->zstream.avail_in > 0);
+   /* Swap the current and previous rows */
+   if (png_ptr->prev_row != NULL)
+   {
+      png_bytep tptr;
+      tptr = png_ptr->prev_row;
+      png_ptr->prev_row = png_ptr->row_buf;
+      png_ptr->row_buf = tptr;
+   }
+   /* Finish row - updates counters and flushes zlib if last row */
+   png_write_finish_row(png_ptr);
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+   png_ptr->flush_rows++;
+   if (png_ptr->flush_dist > 0 &&
+       png_ptr->flush_rows >= png_ptr->flush_dist)
+   {
+      png_write_flush(png_ptr);
+   }
+#endif
+}
+#endif /* PNG_WRITE_SUPPORTED */
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/projects/visualc71/PRJ0041.mak b/libraries/irrlicht-1.8/source/Irrlicht/libpng/projects/visualc71/PRJ0041.mak
new file mode 100644
index 0000000..d8b3aff
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/projects/visualc71/PRJ0041.mak
@@ -0,0 +1,21 @@
+# Prevent "Cannot find missing dependency..." warnings while compiling
+# pngwin.rc (PRJ0041).
+all: $(IntDir)\alloc.h \
+         $(IntDir)\fp.h \
+         $(IntDir)\m68881.h \
+         $(IntDir)\mem.h \
+         $(IntDir)\pngusr.h \
+         $(IntDir)\strings.h \
+         $(IntDir)\unistd.h \
+         $(IntDir)\unixio.h
+$(IntDir)\alloc.h \
+$(IntDir)\fp.h \
+$(IntDir)\m68881.h \
+$(IntDir)\mem.h \
+$(IntDir)\pngusr.h \
+$(IntDir)\strings.h \
+$(IntDir)\unistd.h \
+$(IntDir)\unixio.h:
+        @!echo.>$@
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/projects/visualc71/README.txt b/libraries/irrlicht-1.8/source/Irrlicht/libpng/projects/visualc71/README.txt
new file mode 100644
index 0000000..6edc04c
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/projects/visualc71/README.txt
@@ -0,0 +1,58 @@
+Microsoft Developer Studio Project File, Format Version 7.10 for libpng.
+Copyright (C) 2004 Simon-Pierre Cadieux.
+This code is released under the libpng license.
+For conditions of distribution and use, see copyright notice in png.h
+NOTE: This project will be removed from libpng-1.5.0.  It has
+been replaced with the "vstudio" project.
+Assumptions:
+* The libpng source files are in ..\..
+* The zlib source files are in ..\..\..\zlib
+* The zlib project file is in . /* Warning: This is until the zlib project
+  files get intergrated into the next zlib release. The final zlib project
+  directory will then be ..\..\..\zlib\projects\visualc71. */
+To use:
+1) On the main menu, select "File | Open Solution".
+   Open "libpng.sln".
+2) Display the Solution Explorer view (Ctrl+Alt+L)
+3) Set one of the project as the StartUp project. If you just want to build the
+   binaries set "libpng" as the startup project (Select "libpng" tree view
+   item + Project | Set as StartUp project). If you want to build and test the
+   binaries set it to "pngtest" (Select "pngtest" tree view item +
+   Project | Set as StartUp project)
+4) Select "Build | Configuration Manager...".
+   Choose the configuration you wish to build.
+5) Select "Build | Clean Solution".
+6) Select "Build | Build Solution (Ctrl-Shift-B)"
+This project builds the libpng binaries as follows:
+* Win32_DLL_Release\libpng15.dll      DLL build
+* Win32_DLL_Debug\libpng15d.dll       DLL build (debug version)
+* Win32_DLL_VB\libpng15vb.dll         DLL build for Visual Basic, using stdcall
+* Win32_LIB_Release\libpng.lib        static build
+* Win32_LIB_Debug\libpngd.lib         static build (debug version)
+Notes:
+If you change anything in the source files, or select different compiler
+settings, please change the DLL name to something different than any of
+the above names. Also, make sure that in your "pngusr.h" you define
+PNG_USER_PRIVATEBUILD and PNG_USER_DLLFNAME_POSTFIX according to the
+instructions provided in "pngconf.h".
+All DLLs built by this project use the Microsoft dynamic C runtime library
+MSVCR71.DLL (MSVCR71D.DLL for debug versions).  If you distribute any of the
+above mentioned libraries you may have to include this DLL in your package.
+For a list of files that are redistributable in Visual Studio see
+$(VCINSTALLDIR)\redist.txt.
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/projects/visualc71/README_zlib.txt b/libraries/irrlicht-1.8/source/Irrlicht/libpng/projects/visualc71/README_zlib.txt
new file mode 100644
index 0000000..56a735b
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/projects/visualc71/README_zlib.txt
@@ -0,0 +1,44 @@
+/* WARNING: This file was put in the LibPNG distribution for convenience only.
+            It is expected to be part of the next zlib release under
+            "projects\visualc71\README.txt." */
+Microsoft Developer Studio Project File, Format Version 7.10 for zlib.
+Copyright (C) 2004 Simon-Pierre Cadieux.
+Copyright (C) 2004 Cosmin Truta.
+This code is released under the libpng license.
+For conditions of distribution and use, see copyright notice in zlib.h.
+NOTE: This project will be removed from libpng-1.5.0.  It has
+been replaced with the "vstudio" project.
+To use:
+1) On the main menu, select "File | Open Solution".
+   Open "zlib.sln".
+2) Display the Solution Explorer view (Ctrl+Alt+L)
+3) Set one of the project as the StartUp project. If you just want to build the
+   binaries set "zlib" as the startup project (Select "zlib" tree view item +
+   Project | Set as StartUp project). If you want to build and test the
+   binaries set it to "example" (Select "example" tree view item + Project |
+   Set as StartUp project), If you want to build the minigzip utility set it to
+   "minigzip" (Select "minigzip" tree view item + Project | Set as StartUp
+   project
+4) Select "Build | Configuration Manager...".
+   Choose the configuration you wish to build.
+5) Select "Build | Clean Solution".
+6) Select "Build | Build Solution (Ctrl-Shift-B)"
+This project builds the zlib binaries as follows:
+* Win32_DLL_Release\zlib1.dll       DLL build
+* Win32_DLL_Debug\zlib1d.dll        DLL build (debug version)
+* Win32_LIB_Release\zlib.lib        static build
+* Win32_LIB_Debug\zlibd.lib         static build (debug version)
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/projects/visualc71/libpng.sln b/libraries/irrlicht-1.8/source/Irrlicht/libpng/projects/visualc71/libpng.sln
new file mode 100644
index 0000000..adce68a
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/projects/visualc71/libpng.sln
@@ -0,0 +1,60 @@
+Microsoft Visual Studio Solution File, Format Version 8.00
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "libpng", "libpng.vcproj", "{0008960E-E0DD-41A6-8265-00B31DDB4C21}"
+        ProjectSection(ProjectDependencies) = postProject
+                {2D4F8105-7D21-454C-9932-B47CAB71A5C0} = {2D4F8105-7D21-454C-9932-B47CAB71A5C0}
+        EndProjectSection
+EndProject
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "pngtest", "pngtest.vcproj", "{FD1C2F86-9EEF-47BD-95A4-530917E17FDA}"
+        ProjectSection(ProjectDependencies) = postProject
+                {0008960E-E0DD-41A6-8265-00B31DDB4C21} = {0008960E-E0DD-41A6-8265-00B31DDB4C21}
+        EndProjectSection
+EndProject
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "zlib", "zlib.vcproj", "{2D4F8105-7D21-454C-9932-B47CAB71A5C0}"
+        ProjectSection(ProjectDependencies) = postProject
+        EndProjectSection
+EndProject
+Global
+        GlobalSection(SolutionConfiguration) = preSolution
+                DLL Debug = DLL Debug
+                DLL Release = DLL Release
+                DLL VB = DLL VB
+                LIB Debug = LIB Debug
+                LIB Release = LIB Release
+        EndGlobalSection
+        GlobalSection(ProjectConfiguration) = postSolution
+                {0008960E-E0DD-41A6-8265-00B31DDB4C21}.DLL Debug.ActiveCfg = DLL Debug|Win32
+                {0008960E-E0DD-41A6-8265-00B31DDB4C21}.DLL Debug.Build.0 = DLL Debug|Win32
+                {0008960E-E0DD-41A6-8265-00B31DDB4C21}.DLL Release.ActiveCfg = DLL Release|Win32
+                {0008960E-E0DD-41A6-8265-00B31DDB4C21}.DLL Release.Build.0 = DLL Release|Win32
+                {0008960E-E0DD-41A6-8265-00B31DDB4C21}.DLL VB.ActiveCfg = DLL VB|Win32
+                {0008960E-E0DD-41A6-8265-00B31DDB4C21}.DLL VB.Build.0 = DLL VB|Win32
+                {0008960E-E0DD-41A6-8265-00B31DDB4C21}.LIB Debug.ActiveCfg = LIB Debug|Win32
+                {0008960E-E0DD-41A6-8265-00B31DDB4C21}.LIB Debug.Build.0 = LIB Debug|Win32
+                {0008960E-E0DD-41A6-8265-00B31DDB4C21}.LIB Release.ActiveCfg = LIB Release|Win32
+                {0008960E-E0DD-41A6-8265-00B31DDB4C21}.LIB Release.Build.0 = LIB Release|Win32
+                {FD1C2F86-9EEF-47BD-95A4-530917E17FDA}.DLL Debug.ActiveCfg = DLL Debug|Win32
+                {FD1C2F86-9EEF-47BD-95A4-530917E17FDA}.DLL Debug.Build.0 = DLL Debug|Win32
+                {FD1C2F86-9EEF-47BD-95A4-530917E17FDA}.DLL Release.ActiveCfg = DLL Release|Win32
+                {FD1C2F86-9EEF-47BD-95A4-530917E17FDA}.DLL Release.Build.0 = DLL Release|Win32
+                {FD1C2F86-9EEF-47BD-95A4-530917E17FDA}.DLL VB.ActiveCfg = DLL VB|Win32
+                {FD1C2F86-9EEF-47BD-95A4-530917E17FDA}.DLL VB.Build.0 = DLL VB|Win32
+                {FD1C2F86-9EEF-47BD-95A4-530917E17FDA}.LIB Debug.ActiveCfg = LIB Debug|Win32
+                {FD1C2F86-9EEF-47BD-95A4-530917E17FDA}.LIB Debug.Build.0 = LIB Debug|Win32
+                {FD1C2F86-9EEF-47BD-95A4-530917E17FDA}.LIB Release.ActiveCfg = LIB Release|Win32
+                {FD1C2F86-9EEF-47BD-95A4-530917E17FDA}.LIB Release.Build.0 = LIB Release|Win32
+                {2D4F8105-7D21-454C-9932-B47CAB71A5C0}.DLL Debug.ActiveCfg = DLL Debug|Win32
+                {2D4F8105-7D21-454C-9932-B47CAB71A5C0}.DLL Debug.Build.0 = DLL Debug|Win32
+                {2D4F8105-7D21-454C-9932-B47CAB71A5C0}.DLL Release.ActiveCfg = DLL Release|Win32
+                {2D4F8105-7D21-454C-9932-B47CAB71A5C0}.DLL Release.Build.0 = DLL Release|Win32
+                {2D4F8105-7D21-454C-9932-B47CAB71A5C0}.DLL VB.ActiveCfg = DLL Release|Win32
+                {2D4F8105-7D21-454C-9932-B47CAB71A5C0}.DLL VB.Build.0 = DLL Release|Win32
+                {2D4F8105-7D21-454C-9932-B47CAB71A5C0}.LIB Debug.ActiveCfg = LIB Debug|Win32
+                {2D4F8105-7D21-454C-9932-B47CAB71A5C0}.LIB Debug.Build.0 = LIB Debug|Win32
+                {2D4F8105-7D21-454C-9932-B47CAB71A5C0}.LIB Release.ActiveCfg = LIB Release|Win32
+                {2D4F8105-7D21-454C-9932-B47CAB71A5C0}.LIB Release.Build.0 = LIB Release|Win32
+        EndGlobalSection
+        GlobalSection(ExtensibilityGlobals) = postSolution
+        EndGlobalSection
+        GlobalSection(ExtensibilityAddIns) = postSolution
+        EndGlobalSection
+EndGlobal
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/projects/visualc71/libpng.vcproj b/libraries/irrlicht-1.8/source/Irrlicht/libpng/projects/visualc71/libpng.vcproj
new file mode 100644
index 0000000..e17f4f7
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/projects/visualc71/libpng.vcproj
@@ -0,0 +1,419 @@
+<?xml version="1.0" encoding="Windows-1252"?>
+<VisualStudioProject
+        ProjectType="Visual C++"
+        Version="7.10"
+        Name="libpng"
+        RootNamespace="libpng">
+        <Platforms>
+                <Platform
+                        Name="Win32"/>
+        </Platforms>
+        <Configurations>
+                <Configuration
+                        Name="DLL Release|Win32"
+                        OutputDirectory=".\Win32_DLL_Release"
+                        IntermediateDirectory=".\Win32_DLL_Release"
+                        ConfigurationType="2">
+                        <Tool
+                                Name="VCCLCompilerTool"
+                                InlineFunctionExpansion="1"
+                                AdditionalIncludeDirectories="..\..;..\..\..\zlib"
+                                PreprocessorDefinitions="WIN32;NDEBUG;PNG_BUILD_DLL;ZLIB_DLL;_CRT_SECURE_NO_WARNINGS"
+                                StringPooling="TRUE"
+                                RuntimeLibrary="2"
+                                EnableFunctionLevelLinking="TRUE"
+                                UsePrecompiledHeader="3"
+                                PrecompiledHeaderThrough="pngpriv.h"
+                                WarningLevel="3"
+                                CompileAs="0"/>
+                        <Tool
+                                Name="VCCustomBuildTool"/>
+                        <Tool
+                                Name="VCLinkerTool"
+                                OutputFile="$(OutDir)/libpng15.dll"
+                                LinkIncremental="1"/>
+                        <Tool
+                                Name="VCMIDLTool"/>
+                        <Tool
+                                Name="VCPostBuildEventTool"/>
+                        <Tool
+                                Name="VCPreBuildEventTool"
+                                CommandLine="copy ..\..\scripts\pnglibconf.h.prebuilt ..\..\pnglibconf.h"/>
+                        <Tool
+                                Name="VCPreLinkEventTool"/>
+                        <Tool
+                                Name="VCResourceCompilerTool"
+                                PreprocessorDefinitions="NDEBUG"
+                                Culture="1033"
+                                AdditionalIncludeDirectories="..\..;..\..\..\zlib;$(IntDir)"/>
+                        <Tool
+                                Name="VCWebServiceProxyGeneratorTool"/>
+                        <Tool
+                                Name="VCXMLDataGeneratorTool"/>
+                        <Tool
+                                Name="VCWebDeploymentTool"/>
+                        <Tool
+                                Name="VCManagedWrapperGeneratorTool"/>
+                        <Tool
+                                Name="VCAuxiliaryManagedWrapperGeneratorTool"/>
+                </Configuration>
+                <Configuration
+                        Name="DLL Debug|Win32"
+                        OutputDirectory=".\Win32_DLL_Debug"
+                        IntermediateDirectory=".\Win32_DLL_Debug"
+                        ConfigurationType="2">
+                        <Tool
+                                Name="VCCLCompilerTool"
+                                Optimization="0"
+                                AdditionalIncludeDirectories="..\..;..\..\..\zlib"
+                                PreprocessorDefinitions="WIN32;_DEBUG;DEBUG;PNG_DEBUG=1;PNG_BUILD_DLL;ZLIB_DLL;_CRT_SECURE_NO_WARNINGS"
+                                BasicRuntimeChecks="3"
+                                RuntimeLibrary="3"
+                                UsePrecompiledHeader="3"
+                                PrecompiledHeaderThrough="pngpriv.h"
+                                WarningLevel="3"
+                                DebugInformationFormat="4"
+                                CompileAs="0"/>
+                        <Tool
+                                Name="VCCustomBuildTool"/>
+                        <Tool
+                                Name="VCLinkerTool"
+                                OutputFile="$(OutDir)/libpng15d.dll"
+                                GenerateDebugInformation="TRUE"/>
+                        <Tool
+                                Name="VCMIDLTool"/>
+                        <Tool
+                                Name="VCPostBuildEventTool"/>
+                        <Tool
+                                Name="VCPreBuildEventTool"
+                                CommandLine="copy ..\..\scripts\pnglibconf.h.prebuilt ..\..\pnglibconf.h"/>
+                        <Tool
+                                Name="VCPreLinkEventTool"/>
+                        <Tool
+                                Name="VCResourceCompilerTool"
+                                PreprocessorDefinitions="_DEBUG,PNG_DEBUG=1"
+                                Culture="1033"
+                                AdditionalIncludeDirectories="..\..;..\..\..\zlib;$(IntDir)"/>
+                        <Tool
+                                Name="VCWebServiceProxyGeneratorTool"/>
+                        <Tool
+                                Name="VCXMLDataGeneratorTool"/>
+                        <Tool
+                                Name="VCWebDeploymentTool"/>
+                        <Tool
+                                Name="VCManagedWrapperGeneratorTool"/>
+                        <Tool
+                                Name="VCAuxiliaryManagedWrapperGeneratorTool"/>
+                </Configuration>
+                <Configuration
+                        Name="DLL VB|Win32"
+                        OutputDirectory=".\Win32_DLL_VB"
+                        IntermediateDirectory=".\Win32_DLL_VB"
+                        ConfigurationType="2">
+                        <Tool
+                                Name="VCCLCompilerTool"
+                                InlineFunctionExpansion="1"
+                                AdditionalIncludeDirectories="..\..;..\..\..\zlib"
+                                PreprocessorDefinitions="WIN32;NDEBUG;PNG_BUILD_DLL;ZLIB_DLL;PNGAPI=__stdcall;PNG_NO_MODULEDEF;PNG_LIBPNG_SPECIALBUILD;PNG_USER_PRIVATEBUILD;_CRT_SECURE_NO_WARNINGS"
+                                StringPooling="TRUE"
+                                RuntimeLibrary="2"
+                                EnableFunctionLevelLinking="TRUE"
+                                UsePrecompiledHeader="3"
+                                PrecompiledHeaderThrough="pngpriv.h"
+                                WarningLevel="3"
+                                CompileAs="0"/>
+                        <Tool
+                                Name="VCCustomBuildTool"/>
+                        <Tool
+                                Name="VCLinkerTool"
+                                OutputFile="$(OutDir)/libpng15vb.dll"
+                                LinkIncremental="1"/>
+                        <Tool
+                                Name="VCMIDLTool"/>
+                        <Tool
+                                Name="VCPostBuildEventTool"/>
+                        <Tool
+                                Name="VCPreBuildEventTool"
+                                CommandLine="copy ..\..\scripts\pnglibconf.h.prebuilt ..\..\pnglibconf.h"/>
+                        <Tool
+                                Name="VCPreLinkEventTool"/>
+                        <Tool
+                                Name="VCResourceCompilerTool"
+                                AdditionalOptions="/d PNG_NO_PEDANTIC_WARNINGS /d PNG_LIBPNG_DLLFNAME_POSTFIX=&quot;&quot;&quot;&quot;VB&quot;&quot;&quot;&quot; /d PNG_LIBPNG_SPECIALBUILD=&quot;&quot;&quot;&quot;__stdcall calling convention used for exported functions&quot;&quot;&quot;&quot;"
+                                PreprocessorDefinitions="NDEBUG"
+                                Culture="1033"
+                                AdditionalIncludeDirectories="..\..;..\..\..\zlib;$(IntDir)"/>
+                        <Tool
+                                Name="VCWebServiceProxyGeneratorTool"/>
+                        <Tool
+                                Name="VCXMLDataGeneratorTool"/>
+                        <Tool
+                                Name="VCWebDeploymentTool"/>
+                        <Tool
+                                Name="VCManagedWrapperGeneratorTool"/>
+                        <Tool
+                                Name="VCAuxiliaryManagedWrapperGeneratorTool"/>
+                </Configuration>
+                <Configuration
+                        Name="LIB Release|Win32"
+                        OutputDirectory=".\Win32_LIB_Release"
+                        IntermediateDirectory=".\Win32_LIB_Release"
+                        ConfigurationType="4">
+                        <Tool
+                                Name="VCCLCompilerTool"
+                                InlineFunctionExpansion="1"
+                                AdditionalIncludeDirectories="..\..;..\..\..\zlib"
+                                PreprocessorDefinitions="WIN32;NDEBUG;_CRT_SECURE_NO_WARNINGS"
+                                StringPooling="TRUE"
+                                RuntimeLibrary="0"
+                                EnableFunctionLevelLinking="TRUE"
+                                UsePrecompiledHeader="3"
+                                PrecompiledHeaderThrough="pngpriv.h"
+                                WarningLevel="3"
+                                CompileAs="0"/>
+                        <Tool
+                                Name="VCCustomBuildTool"/>
+                        <Tool
+                                Name="VCLibrarianTool"
+                                OutputFile="$(OutDir)/libpng.lib"/>
+                        <Tool
+                                Name="VCMIDLTool"/>
+                        <Tool
+                                Name="VCPostBuildEventTool"/>
+                        <Tool
+                                Name="VCPreBuildEventTool"
+                                CommandLine="copy ..\..\scripts\pnglibconf.h.prebuilt ..\..\pnglibconf.h"/>
+                        <Tool
+                                Name="VCPreLinkEventTool"/>
+                        <Tool
+                                Name="VCResourceCompilerTool"/>
+                        <Tool
+                                Name="VCWebServiceProxyGeneratorTool"/>
+                        <Tool
+                                Name="VCXMLDataGeneratorTool"/>
+                        <Tool
+                                Name="VCManagedWrapperGeneratorTool"/>
+                        <Tool
+                                Name="VCAuxiliaryManagedWrapperGeneratorTool"/>
+                </Configuration>
+                <Configuration
+                        Name="LIB Debug|Win32"
+                        OutputDirectory=".\Win32_LIB_Debug"
+                        IntermediateDirectory=".\Win32_LIB_Debug"
+                        ConfigurationType="4">
+                        <Tool
+                                Name="VCCLCompilerTool"
+                                Optimization="0"
+                                AdditionalIncludeDirectories="..\..;..\..\..\zlib"
+                                PreprocessorDefinitions="WIN32;_DEBUG;DEBUG;PNG_DEBUG=1;_CRT_SECURE_NO_WARNINGS"
+                                BasicRuntimeChecks="3"
+                                RuntimeLibrary="1"
+                                UsePrecompiledHeader="3"
+                                PrecompiledHeaderThrough="pngpriv.h"
+                                WarningLevel="3"
+                                DebugInformationFormat="4"
+                                CompileAs="0"/>
+                        <Tool
+                                Name="VCCustomBuildTool"/>
+                        <Tool
+                                Name="VCLibrarianTool"
+                                OutputFile="$(OutDir)/libpngd.lib"/>
+                        <Tool
+                                Name="VCMIDLTool"/>
+                        <Tool
+                                Name="VCPostBuildEventTool"/>
+                        <Tool
+                                Name="VCPreBuildEventTool"
+                                CommandLine="copy ..\..\scripts\pnglibconf.h.prebuilt ..\..\pnglibconf.h"/>
+                        <Tool
+                                Name="VCPreLinkEventTool"/>
+                        <Tool
+                                Name="VCResourceCompilerTool"/>
+                        <Tool
+                                Name="VCWebServiceProxyGeneratorTool"/>
+                        <Tool
+                                Name="VCXMLDataGeneratorTool"/>
+                        <Tool
+                                Name="VCManagedWrapperGeneratorTool"/>
+                        <Tool
+                                Name="VCAuxiliaryManagedWrapperGeneratorTool"/>
+                </Configuration>
+        </Configurations>
+        <References>
+        </References>
+        <Files>
+                <Filter
+                        Name="Source Files"
+                        Filter="cpp;c;cxx;rc;def;r;odl;idl;hpj;bat">
+                        <File
+                                RelativePath="..\..\png.c">
+                                <FileConfiguration
+                                        Name="DLL Release|Win32">
+                                        <Tool
+                                                Name="VCCLCompilerTool"
+                                                UsePrecompiledHeader="0"/>
+                                </FileConfiguration>
+                                <FileConfiguration
+                                        Name="DLL Debug|Win32">
+                                        <Tool
+                                                Name="VCCLCompilerTool"
+                                                UsePrecompiledHeader="0"/>
+                                </FileConfiguration>
+                                <FileConfiguration
+                                        Name="DLL VB|Win32">
+                                        <Tool
+                                                Name="VCCLCompilerTool"
+                                                UsePrecompiledHeader="0"/>
+                                </FileConfiguration>
+                                <FileConfiguration
+                                        Name="LIB Release|Win32">
+                                        <Tool
+                                                Name="VCCLCompilerTool"
+                                                UsePrecompiledHeader="0"/>
+                                </FileConfiguration>
+                                <FileConfiguration
+                                        Name="LIB Debug|Win32">
+                                        <Tool
+                                                Name="VCCLCompilerTool"
+                                                UsePrecompiledHeader="0"/>
+                                </FileConfiguration>
+                        </File>
+                        <File
+                                RelativePath="..\..\pngerror.c">
+                                <FileConfiguration
+                                        Name="DLL Release|Win32">
+                                        <Tool
+                                                Name="VCCLCompilerTool"
+                                                UsePrecompiledHeader="1"/>
+                                </FileConfiguration>
+                                <FileConfiguration
+                                        Name="DLL Debug|Win32">
+                                        <Tool
+                                                Name="VCCLCompilerTool"
+                                                UsePrecompiledHeader="1"/>
+                                </FileConfiguration>
+                                <FileConfiguration
+                                        Name="DLL VB|Win32">
+                                        <Tool
+                                                Name="VCCLCompilerTool"
+                                                UsePrecompiledHeader="1"/>
+                                </FileConfiguration>
+                                <FileConfiguration
+                                        Name="LIB Release|Win32">
+                                        <Tool
+                                                Name="VCCLCompilerTool"
+                                                UsePrecompiledHeader="1"/>
+                                </FileConfiguration>
+                                <FileConfiguration
+                                        Name="LIB Debug|Win32">
+                                        <Tool
+                                                Name="VCCLCompilerTool"
+                                                UsePrecompiledHeader="1"/>
+                                </FileConfiguration>
+                        </File>
+                        <File
+                                RelativePath="..\..\pngget.c">
+                        </File>
+                        <File
+                                RelativePath="..\..\pngmem.c">
+                        </File>
+                        <File
+                                RelativePath="..\..\pngpread.c">
+                        </File>
+                        <File
+                                RelativePath="..\..\pngread.c">
+                        </File>
+                        <File
+                                RelativePath="..\..\pngrio.c">
+                        </File>
+                        <File
+                                RelativePath="..\..\pngrtran.c">
+                        </File>
+                        <File
+                                RelativePath="..\..\pngrutil.c">
+                        </File>
+                        <File
+                                RelativePath="..\..\pngset.c">
+                        </File>
+                        <File
+                                RelativePath="..\..\pngtrans.c">
+                        </File>
+                        <File
+                                RelativePath="..\..\pngwio.c">
+                        </File>
+                        <File
+                                RelativePath="..\..\pngwrite.c">
+                        </File>
+                        <File
+                                RelativePath="..\..\pngwtran.c">
+                        </File>
+                        <File
+                                RelativePath="..\..\pngwutil.c">
+                        </File>
+                </Filter>
+                <Filter
+                        Name="Header Files"
+                        Filter="h;hpp;hxx;hm;inl">
+                        <File
+                                RelativePath="..\..\png.h">
+                        </File>
+                        <File
+                                RelativePath="..\..\pngconf.h">
+                        </File>
+                        <File
+                                RelativePath="..\..\pngpriv.h">
+                        </File>
+                </Filter>
+                <Filter
+                        Name="Resource Files"
+                        Filter="ico;cur;bmp;dlg;rc2;rct;bin;rgs;gif;jpg;jpeg;jpe">
+                        <File
+                                RelativePath="..\..\scripts\pngwin.rc">
+                                <FileConfiguration
+                                        Name="LIB Release|Win32"
+                                        ExcludedFromBuild="TRUE">
+                                        <Tool
+                                                Name="VCResourceCompilerTool"/>
+                                </FileConfiguration>
+                                <FileConfiguration
+                                        Name="LIB Debug|Win32"
+                                        ExcludedFromBuild="TRUE">
+                                        <Tool
+                                                Name="VCResourceCompilerTool"/>
+                                </FileConfiguration>
+                        </File>
+                </Filter>
+                <File
+                        RelativePath=".\PRJ0041.mak">
+                        <FileConfiguration
+                                Name="DLL Release|Win32">
+                                <Tool
+                                        Name="VCCustomBuildTool"
+                                        Description="Create dummy include files to prevent &quot;Cannot find missing dependency...&quot; warnings."
+                                        CommandLine="nmake -f PRJ0041.mak IntDir=$(IntDir)"
+                                        Outputs="$(IntDir)\alloc.h;$(IntDir)\fp.h;$(IntDir)\m68881.h;$(IntDir)\mem.h;$(IntDir)\pngusr.h;$(IntDir)\strings.h;$(IntDir)\unistd.h;$(IntDir)\unixio.h"/>
+                        </FileConfiguration>
+                        <FileConfiguration
+                                Name="DLL Debug|Win32">
+                                <Tool
+                                        Name="VCCustomBuildTool"
+                                        Description="Create dummy include files to prevent &quot;Cannot find missing dependency...&quot; warnings."
+                                        CommandLine="nmake -f PRJ0041.mak IntDir=$(IntDir)"
+                                        Outputs="$(IntDir)\alloc.h;$(IntDir)\fp.h;$(IntDir)\m68881.h;$(IntDir)\mem.h;$(IntDir)\pngusr.h;$(IntDir)\strings.h;$(IntDir)\unistd.h;$(IntDir)\unixio.h"/>
+                        </FileConfiguration>
+                        <FileConfiguration
+                                Name="DLL VB|Win32">
+                                <Tool
+                                        Name="VCCustomBuildTool"
+                                        Description="Create dummy include files to prevent &quot;Cannot find missing dependency...&quot; warnings."
+                                        CommandLine="nmake -f PRJ0041.mak IntDir=$(IntDir)"
+                                        Outputs="$(IntDir)\alloc.h;$(IntDir)\fp.h;$(IntDir)\m68881.h;$(IntDir)\mem.h;$(IntDir)\pngusr.h;$(IntDir)\strings.h;$(IntDir)\unistd.h;$(IntDir)\unixio.h"/>
+                        </FileConfiguration>
+                </File>
+                <File
+                        RelativePath="README.txt">
+                </File>
+        </Files>
+        <Globals>
+        </Globals>
+</VisualStudioProject>
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/projects/visualc71/pngtest.vcproj b/libraries/irrlicht-1.8/source/Irrlicht/libpng/projects/visualc71/pngtest.vcproj
new file mode 100644
index 0000000..ac82ff9
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/projects/visualc71/pngtest.vcproj
@@ -0,0 +1,267 @@
+<?xml version="1.0" encoding="Windows-1252"?>
+<VisualStudioProject
+        ProjectType="Visual C++"
+        Version="7.10"
+        Name="pngtest"
+        RootNamespace="pngtest">
+        <Platforms>
+                <Platform
+                        Name="Win32"/>
+        </Platforms>
+        <Configurations>
+                <Configuration
+                        Name="DLL Release|Win32"
+                        OutputDirectory=".\Win32_DLL_Release\Test"
+                        IntermediateDirectory=".\Win32_DLL_Release\Test"
+                        ConfigurationType="1">
+                        <Tool
+                                Name="VCCLCompilerTool"
+                                InlineFunctionExpansion="1"
+                                AdditionalIncludeDirectories="..\..\scripts;..\..\..\zlib"
+                                PreprocessorDefinitions="WIN32;NDEBUG;PNG_DLL;PNG_NO_STDIO;_CRT_SECURE_NO_WARNINGS"
+                                StringPooling="TRUE"
+                                RuntimeLibrary="2"
+                                EnableFunctionLevelLinking="TRUE"
+                                WarningLevel="3"
+                                CompileAs="0"/>
+                        <Tool
+                                Name="VCCustomBuildTool"
+                                Description="Testing..."
+                                CommandLine="set path=$(OutDir)\..;$(OutDir)\..\ZLib
+$(TargetPath) ..\..\pngtest.png $(IntDir)\pngout.png"
+                                Outputs="$(IntDir)\pngout.png"/>
+                        <Tool
+                                Name="VCLinkerTool"
+                                OutputFile="$(OutDir)/pngtest.exe"
+                                LinkIncremental="1"
+                                SubSystem="1"/>
+                        <Tool
+                                Name="VCMIDLTool"/>
+                        <Tool
+                                Name="VCPostBuildEventTool"/>
+                        <Tool
+                                Name="VCPreBuildEventTool"/>
+                        <Tool
+                                Name="VCPreLinkEventTool"/>
+                        <Tool
+                                Name="VCResourceCompilerTool"/>
+                        <Tool
+                                Name="VCWebServiceProxyGeneratorTool"/>
+                        <Tool
+                                Name="VCXMLDataGeneratorTool"/>
+                        <Tool
+                                Name="VCWebDeploymentTool"/>
+                        <Tool
+                                Name="VCManagedWrapperGeneratorTool"/>
+                        <Tool
+                                Name="VCAuxiliaryManagedWrapperGeneratorTool"/>
+                </Configuration>
+                <Configuration
+                        Name="DLL Debug|Win32"
+                        OutputDirectory=".\Win32_DLL_Debug\Test"
+                        IntermediateDirectory=".\Win32_DLL_Debug\Test"
+                        ConfigurationType="1">
+                        <Tool
+                                Name="VCCLCompilerTool"
+                                Optimization="0"
+                                AdditionalIncludeDirectories="..\..\scripts;..\..\..\zlib"
+                                PreprocessorDefinitions="WIN32;_DEBUG;PNG_DLL;PNG_NO_STDIO;_CRT_SECURE_NO_WARNINGS"
+                                BasicRuntimeChecks="3"
+                                RuntimeLibrary="3"
+                                WarningLevel="3"
+                                DebugInformationFormat="4"
+                                CompileAs="0"/>
+                        <Tool
+                                Name="VCCustomBuildTool"
+                                Description="Testing..."
+                                CommandLine="set path=$(OutDir)\..;$(OutDir)\..\ZLib
+$(TargetPath) ..\..\pngtest.png $(IntDir)\pngout.png"
+                                Outputs="$(IntDir)\pngout.png"/>
+                        <Tool
+                                Name="VCLinkerTool"
+                                OutputFile="$(OutDir)/pngtest.exe"
+                                GenerateDebugInformation="TRUE"
+                                SubSystem="1"
+                                TargetMachine="1"/>
+                        <Tool
+                                Name="VCMIDLTool"/>
+                        <Tool
+                                Name="VCPostBuildEventTool"/>
+                        <Tool
+                                Name="VCPreBuildEventTool"/>
+                        <Tool
+                                Name="VCPreLinkEventTool"/>
+                        <Tool
+                                Name="VCResourceCompilerTool"/>
+                        <Tool
+                                Name="VCWebServiceProxyGeneratorTool"/>
+                        <Tool
+                                Name="VCXMLDataGeneratorTool"/>
+                        <Tool
+                                Name="VCWebDeploymentTool"/>
+                        <Tool
+                                Name="VCManagedWrapperGeneratorTool"/>
+                        <Tool
+                                Name="VCAuxiliaryManagedWrapperGeneratorTool"/>
+                </Configuration>
+                <Configuration
+                        Name="DLL VB|Win32"
+                        OutputDirectory=".\Win32_DLL_VB\Test"
+                        IntermediateDirectory=".\Win32_DLL_VB\Test"
+                        ConfigurationType="1">
+                        <Tool
+                                Name="VCCLCompilerTool"
+                                InlineFunctionExpansion="1"
+                                AdditionalIncludeDirectories="..\..\scripts;..\..\..\zlib"
+                                PreprocessorDefinitions="WIN32;NDEBUG;PNG_DLL;PNG_NO_STDIO;PNGAPI=__stdcall;PNG_USER_PRIVATEBUILD;_CRT_SECURE_NO_WARNINGS"
+                                StringPooling="TRUE"
+                                RuntimeLibrary="2"
+                                EnableFunctionLevelLinking="TRUE"
+                                WarningLevel="2"
+                                CallingConvention="2"
+                                CompileAs="0"/>
+                        <Tool
+                                Name="VCCustomBuildTool"
+                                Description="Testing..."
+                                CommandLine="set path=$(OutDir)\..;$(OutDir)\..\..\Win32_DLL_Release\ZLib
+$(TargetPath) ..\..\pngtest.png $(IntDir)\pngout.png"
+                                Outputs="$(IntDir)\pngout.png"/>
+                        <Tool
+                                Name="VCLinkerTool"
+                                OutputFile="$(OutDir)/pngtest.exe"
+                                LinkIncremental="1"
+                                IgnoreDefaultLibraryNames="$(IntDir)\libpng15b.lib"
+                                SubSystem="1"
+                                TargetMachine="1"/>
+                        <Tool
+                                Name="VCMIDLTool"/>
+                        <Tool
+                                Name="VCPostBuildEventTool"/>
+                        <Tool
+                                Name="VCPreBuildEventTool"/>
+                        <Tool
+                                Name="VCPreLinkEventTool"/>
+                        <Tool
+                                Name="VCResourceCompilerTool"/>
+                        <Tool
+                                Name="VCWebServiceProxyGeneratorTool"/>
+                        <Tool
+                                Name="VCXMLDataGeneratorTool"/>
+                        <Tool
+                                Name="VCWebDeploymentTool"/>
+                        <Tool
+                                Name="VCManagedWrapperGeneratorTool"/>
+                        <Tool
+                                Name="VCAuxiliaryManagedWrapperGeneratorTool"/>
+                </Configuration>
+                <Configuration
+                        Name="LIB Release|Win32"
+                        OutputDirectory=".\Win32_LIB_Release\Test"
+                        IntermediateDirectory=".\Win32_LIB_Release\Test"
+                        ConfigurationType="1">
+                        <Tool
+                                Name="VCCLCompilerTool"
+                                InlineFunctionExpansion="1"
+                                AdditionalIncludeDirectories="..\..\scripts;..\..\..\zlib"
+                                PreprocessorDefinitions="WIN32;_DEBUG;_CRT_SECURE_NO_WARNINGS"
+                                StringPooling="TRUE"
+                                RuntimeLibrary="0"
+                                EnableFunctionLevelLinking="TRUE"
+                                WarningLevel="3"
+                                CompileAs="0"/>
+                        <Tool
+                                Name="VCCustomBuildTool"
+                                Description="Testing..."
+                                CommandLine="set path=$(OutDir)\..;$(OutDir)\..\ZLib
+$(TargetPath) ..\..\pngtest.png $(IntDir)\pngout.png"
+                                Outputs="$(IntDir)\pngout.png"/>
+                        <Tool
+                                Name="VCLinkerTool"
+                                OutputFile="$(OutDir)/pngtest.exe"
+                                LinkIncremental="1"
+                                SubSystem="1"
+                                TargetMachine="1"/>
+                        <Tool
+                                Name="VCMIDLTool"/>
+                        <Tool
+                                Name="VCPostBuildEventTool"/>
+                        <Tool
+                                Name="VCPreBuildEventTool"/>
+                        <Tool
+                                Name="VCPreLinkEventTool"/>
+                        <Tool
+                                Name="VCResourceCompilerTool"/>
+                        <Tool
+                                Name="VCWebServiceProxyGeneratorTool"/>
+                        <Tool
+                                Name="VCXMLDataGeneratorTool"/>
+                        <Tool
+                                Name="VCWebDeploymentTool"/>
+                        <Tool
+                                Name="VCManagedWrapperGeneratorTool"/>
+                        <Tool
+                                Name="VCAuxiliaryManagedWrapperGeneratorTool"/>
+                </Configuration>
+                <Configuration
+                        Name="LIB Debug|Win32"
+                        OutputDirectory=".\Win32_LIB_Debug\Test"
+                        IntermediateDirectory=".\Win32_LIB_Debug\Test"
+                        ConfigurationType="1">
+                        <Tool
+                                Name="VCCLCompilerTool"
+                                Optimization="0"
+                                AdditionalIncludeDirectories="..\..\scripts;..\..\..\zlib"
+                                PreprocessorDefinitions="WIN32;_DEBUG;_CRT_SECURE_NO_WARNINGS"
+                                BasicRuntimeChecks="3"
+                                RuntimeLibrary="1"
+                                WarningLevel="3"
+                                DebugInformationFormat="4"
+                                CompileAs="0"/>
+                        <Tool
+                                Name="VCCustomBuildTool"
+                                Description="Testing..."
+                                CommandLine="set path=$(OutDir)\..;$(OutDir)\..\ZLib
+$(TargetPath) ..\..\pngtest.png $(IntDir)\pngout.png"
+                                Outputs="$(IntDir)\pngout.png"/>
+                        <Tool
+                                Name="VCLinkerTool"
+                                OutputFile="$(OutDir)/pngtest.exe"
+                                GenerateDebugInformation="TRUE"
+                                SubSystem="1"
+                                TargetMachine="1"/>
+                        <Tool
+                                Name="VCMIDLTool"/>
+                        <Tool
+                                Name="VCPostBuildEventTool"/>
+                        <Tool
+                                Name="VCPreBuildEventTool"/>
+                        <Tool
+                                Name="VCPreLinkEventTool"/>
+                        <Tool
+                                Name="VCResourceCompilerTool"/>
+                        <Tool
+                                Name="VCWebServiceProxyGeneratorTool"/>
+                        <Tool
+                                Name="VCXMLDataGeneratorTool"/>
+                        <Tool
+                                Name="VCWebDeploymentTool"/>
+                        <Tool
+                                Name="VCManagedWrapperGeneratorTool"/>
+                        <Tool
+                                Name="VCAuxiliaryManagedWrapperGeneratorTool"/>
+                </Configuration>
+        </Configurations>
+        <References>
+        </References>
+        <Files>
+                <Filter
+                        Name="Source Files"
+                        Filter="cpp;c;cxx;rc;def;r;odl;idl;hpj;bat">
+                        <File
+                                RelativePath="..\..\pngtest.c">
+                        </File>
+                </Filter>
+        </Files>
+        <Globals>
+        </Globals>
+</VisualStudioProject>
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/projects/visualc71/zlib.vcproj b/libraries/irrlicht-1.8/source/Irrlicht/libpng/projects/visualc71/zlib.vcproj
new file mode 100644
index 0000000..614b869
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/projects/visualc71/zlib.vcproj
@@ -0,0 +1,391 @@
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+                                Name="VCWebDeploymentTool"/>
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+                                Name="VCManagedWrapperGeneratorTool"/>
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+                                Name="VCLinkerTool"
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+                                Name="VCResourceCompilerTool"
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+                                Name="VCWebServiceProxyGeneratorTool"/>
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+                                Name="VCXMLDataGeneratorTool"/>
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+                                Name="VCWebDeploymentTool"/>
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+                                Name="VCManagedWrapperGeneratorTool"/>
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+                                Name="VCAuxiliaryManagedWrapperGeneratorTool"/>
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+                                Name="VCCustomBuildTool"/>
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+                                Name="VCLibrarianTool"
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+                                Name="VCPostBuildEventTool"/>
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+                                Name="VCPreBuildEventTool"/>
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+                                Name="VCPreLinkEventTool"/>
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+                                Name="VCResourceCompilerTool"/>
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+                                Name="VCWebServiceProxyGeneratorTool"/>
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+                                Name="VCXMLDataGeneratorTool"/>
+                        <Tool
+                                Name="VCManagedWrapperGeneratorTool"/>
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+                                Name="VCAuxiliaryManagedWrapperGeneratorTool"/>
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+                <Configuration
+                        Name="LIB Debug|Win32"
+                        OutputDirectory=".\Win32_LIB_Debug\ZLib"
+                        IntermediateDirectory=".\Win32_LIB_Debug\ZLib"
+                        ConfigurationType="4">
+                        <Tool
+                                Name="VCCLCompilerTool"
+                                Optimization="0"
+                                AdditionalIncludeDirectories="..\..\..\zlib"
+                                PreprocessorDefinitions="WIN32;_DEBUG;_CRT_SECURE_NO_WARNINGS;_CRT_NONSTDC_NO_WARNINGS"
+                                BasicRuntimeChecks="3"
+                                RuntimeLibrary="1"
+                                WarningLevel="3"
+                                DebugInformationFormat="4"
+                                CompileAs="1"/>
+                        <Tool
+                                Name="VCCustomBuildTool"/>
+                        <Tool
+                                Name="VCLibrarianTool"
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+                                Name="VCPreBuildEventTool"/>
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+                        </File>
+                        <File
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+                        <File
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+                        </File>
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+                        <File
+                                RelativePath="..\..\..\zlib\win32\zlib1.rc">
+                                <FileConfiguration
+                                        Name="LIB Release|Win32"
+                                        ExcludedFromBuild="TRUE">
+                                        <Tool
+                                                Name="VCResourceCompilerTool"/>
+                                </FileConfiguration>
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+                                        ExcludedFromBuild="TRUE">
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+                                                Name="VCResourceCompilerTool"/>
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+                </Filter>
+                <Filter
+                        Name="Assembler Files (Unsupported)"
+                        Filter="asm;obj;c;cpp;cxx;h;hpp;hxx">
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+                                RelativePath="..\..\..\zlib\contrib\masmx86\gvmat32.asm">
+                                <FileConfiguration
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+                                        ExcludedFromBuild="TRUE">
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diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/projects/vstudio/libpng/libpng.vcxproj b/libraries/irrlicht-1.8/source/Irrlicht/libpng/projects/vstudio/libpng/libpng.vcxproj
new file mode 100644
index 0000000..165bfa6
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/projects/vstudio/libpng/libpng.vcxproj
@@ -0,0 +1,233 @@
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+    </ClCompile>
+    <Link>
+      <SubSystem>Console</SubSystem>
+      <GenerateDebugInformation>true</GenerateDebugInformation>
+      <EnableCOMDATFolding>true</EnableCOMDATFolding>
+      <OptimizeReferences>true</OptimizeReferences>
+      <AdditionalDependencies>libpng15.lib;zlib.lib</AdditionalDependencies>
+      <AdditionalLibraryDirectories>$(OutDir)</AdditionalLibraryDirectories>
+      <LinkTimeCodeGeneration>UseLinkTimeCodeGeneration</LinkTimeCodeGeneration>
+    </Link>
+    <CustomBuildStep>
+      <Message>Executing PNG validation program</Message>
+      <Command>"$(OutDir)pngvalid.exe" --touch "$(IntDir)pngvalid.out"</Command>
+      <Outputs>$(IntDir)pngvalid.out</Outputs>
+      <Inputs>$(OutDir)pngvalid.exe</Inputs>
+    </CustomBuildStep>
+  </ItemDefinitionGroup>
+  <ItemGroup>
+    <ClCompile Include="..\..\..\contrib\libtests\pngvalid.c" />
+  </ItemGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
+  <ImportGroup Label="ExtensionTargets">
+  </ImportGroup>
+</Project>
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/projects/vstudio/readme.txt b/libraries/irrlicht-1.8/source/Irrlicht/libpng/projects/vstudio/readme.txt
new file mode 100644
index 0000000..4828f55
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/projects/vstudio/readme.txt
@@ -0,0 +1,64 @@
+VisualStudio instructions
+libpng version 1.5.9 - February 18, 2012
+Copyright (c) 1998-2010 Glenn Randers-Pehrson
+This code is released under the libpng license.
+For conditions of distribution and use, see the disclaimer
+and license in png.h
+This directory  contains support for building libpng under MicroSoft
+VisualStudio 2010.  It may also work under later versions of VisualStudio.
+You should be familiar with VisualStudio before using this directory.
+Initial preparations
+====================
+You must enter some information in zlib.props before attempting to build
+with this 'solution'.  Please read and edit zlib.props first.  You will
+probably not be familiar with the contents of zlib.props - do not worry,
+it is mostly harmless.
+This is all you need to do to build the 'release' and 'release library'
+configurations.
+Debugging
+=========
+The release configurations default to /Ox optimization.  Full debugging
+information is produced (in the .pdb), but if you encounter a problem the
+optimization may make it difficult to debug.  Simply rebuild with a lower
+optimization level (e.g. /Od.)
+Linking your application
+========================
+Normally you should link against the 'release' configuration.  This builds a
+DLL for libpng 1.5 with the default runtime options used by Visual Studio
+2010.  In particular the runtime library is the "MultiThreaded DLL" version.
+If you use Visual Studio defaults to build your application you will have no
+problems.
+If you don't use the Visual Studio defaults your application must still be built
+with the default runtime option (/MD).  If, for some reason, it is not then your
+application will crash inside libpng15.dll as soon as libpng tries to read
+from a file handle you pass in.
+If you do not want to use the DLL, for example for a very small application,
+the 'release library' configuration may be more appropriate.  This is built
+with a non-standard runtime library - the "MultiThreaded" version.  When you
+build your application it must be compiled with this option (/MT), otherwise
+it will not build (if you are lucky) or crash (if you are not.)
+Stop reading here
+=================
+You have enough information to build a working application.
+Debug versions have limited support
+===================================
+This solution includes limited support for debug versions of libpng.  You
+do not need these unless your own solution itself uses debug builds (it is
+far more effective to debug on the release builds, there is no point building
+a special debug build.)
+The debug build of libpng is minimally supported.  Support for debug builds of
+zlib is also minimal.  You really don't want to do this.
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/projects/vstudio/vstudio.sln b/libraries/irrlicht-1.8/source/Irrlicht/libpng/projects/vstudio/vstudio.sln
new file mode 100644
index 0000000..c6c50e4
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/projects/vstudio/vstudio.sln
@@ -0,0 +1,87 @@
+Microsoft Visual Studio Solution File, Format Version 11.00
+# Visual Studio 2010
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "libpng", "libpng\libpng.vcxproj", "{D6973076-9317-4EF2-A0B8-B7A18AC0713E}"
+        ProjectSection(ProjectDependencies) = postProject
+                {60F89955-91C6-3A36-8000-13C592FEC2DF} = {60F89955-91C6-3A36-8000-13C592FEC2DF}
+                {EB33566E-DA7F-4D28-9077-88C0B7C77E35} = {EB33566E-DA7F-4D28-9077-88C0B7C77E35}
+        EndProjectSection
+EndProject
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "pngtest", "pngtest\pngtest.vcxproj", "{228BA965-50D5-42B2-8BCF-AFCC227E3C1D}"
+        ProjectSection(ProjectDependencies) = postProject
+                {60F89955-91C6-3A36-8000-13C592FEC2DF} = {60F89955-91C6-3A36-8000-13C592FEC2DF}
+                {EB33566E-DA7F-4D28-9077-88C0B7C77E35} = {EB33566E-DA7F-4D28-9077-88C0B7C77E35}
+                {D6973076-9317-4EF2-A0B8-B7A18AC0713E} = {D6973076-9317-4EF2-A0B8-B7A18AC0713E}
+        EndProjectSection
+EndProject
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "zlib", "zlib\zlib.vcxproj", "{60F89955-91C6-3A36-8000-13C592FEC2DF}"
+EndProject
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "pngvalid", "pngvalid\pngvalid.vcxproj", "{9B36B6FE-7FC0-434F-A71F-BBEF8099F1D8}"
+        ProjectSection(ProjectDependencies) = postProject
+                {60F89955-91C6-3A36-8000-13C592FEC2DF} = {60F89955-91C6-3A36-8000-13C592FEC2DF}
+                {EB33566E-DA7F-4D28-9077-88C0B7C77E35} = {EB33566E-DA7F-4D28-9077-88C0B7C77E35}
+                {D6973076-9317-4EF2-A0B8-B7A18AC0713E} = {D6973076-9317-4EF2-A0B8-B7A18AC0713E}
+        EndProjectSection
+EndProject
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "pnglibconf", "pnglibconf\pnglibconf.vcxproj", "{EB33566E-DA7F-4D28-9077-88C0B7C77E35}"
+EndProject
+Global
+        GlobalSection(SolutionConfigurationPlatforms) = preSolution
+                Debug Library|Win32 = Debug Library|Win32
+                Debug|Win32 = Debug|Win32
+                Release Library|Win32 = Release Library|Win32
+                Release|Win32 = Release|Win32
+        EndGlobalSection
+        GlobalSection(ProjectConfigurationPlatforms) = postSolution
+                {D6973076-9317-4EF2-A0B8-B7A18AC0713E}.Debug Library|Win32.ActiveCfg = Debug Library|Win32
+                {D6973076-9317-4EF2-A0B8-B7A18AC0713E}.Debug Library|Win32.Build.0 = Debug Library|Win32
+                {D6973076-9317-4EF2-A0B8-B7A18AC0713E}.Debug|Win32.ActiveCfg = Debug|Win32
+                {D6973076-9317-4EF2-A0B8-B7A18AC0713E}.Debug|Win32.Build.0 = Debug|Win32
+                {D6973076-9317-4EF2-A0B8-B7A18AC0713E}.Release Library|Win32.ActiveCfg = Release Library|Win32
+                {D6973076-9317-4EF2-A0B8-B7A18AC0713E}.Release Library|Win32.Build.0 = Release Library|Win32
+                {D6973076-9317-4EF2-A0B8-B7A18AC0713E}.Release|Win32.ActiveCfg = Release|Win32
+                {D6973076-9317-4EF2-A0B8-B7A18AC0713E}.Release|Win32.Build.0 = Release|Win32
+                {228BA965-50D5-42B2-8BCF-AFCC227E3C1D}.Debug Library|Win32.ActiveCfg = Debug Library|Win32
+                {228BA965-50D5-42B2-8BCF-AFCC227E3C1D}.Debug Library|Win32.Build.0 = Debug Library|Win32
+                {228BA965-50D5-42B2-8BCF-AFCC227E3C1D}.Debug|Win32.ActiveCfg = Debug|Win32
+                {228BA965-50D5-42B2-8BCF-AFCC227E3C1D}.Debug|Win32.Build.0 = Debug|Win32
+                {228BA965-50D5-42B2-8BCF-AFCC227E3C1D}.Release Library|Win32.ActiveCfg = Release Library|Win32
+                {228BA965-50D5-42B2-8BCF-AFCC227E3C1D}.Release Library|Win32.Build.0 = Release Library|Win32
+                {228BA965-50D5-42B2-8BCF-AFCC227E3C1D}.Release|Win32.ActiveCfg = Release|Win32
+                {228BA965-50D5-42B2-8BCF-AFCC227E3C1D}.Release|Win32.Build.0 = Release|Win32
+                {60F89955-91C6-3A36-8000-13C592FEC2DF}.Debug Library|Win32.ActiveCfg = Debug Library|Win32
+                {60F89955-91C6-3A36-8000-13C592FEC2DF}.Debug Library|Win32.Build.0 = Debug Library|Win32
+                {60F89955-91C6-3A36-8000-13C592FEC2DF}.Debug|Win32.ActiveCfg = Debug|Win32
+                {60F89955-91C6-3A36-8000-13C592FEC2DF}.Debug|Win32.Build.0 = Debug|Win32
+                {60F89955-91C6-3A36-8000-13C592FEC2DF}.Release Library|Win32.ActiveCfg = Release Library|Win32
+                {60F89955-91C6-3A36-8000-13C592FEC2DF}.Release Library|Win32.Build.0 = Release Library|Win32
+                {60F89955-91C6-3A36-8000-13C592FEC2DF}.Release|Win32.ActiveCfg = Release|Win32
+                {60F89955-91C6-3A36-8000-13C592FEC2DF}.Release|Win32.Build.0 = Release|Win32
+                {9B36B6FE-7FC0-434F-A71F-BBEF8099F1D8}.Debug Library|Win32.ActiveCfg = Debug Library|Win32
+                {9B36B6FE-7FC0-434F-A71F-BBEF8099F1D8}.Debug Library|Win32.Build.0 = Debug Library|Win32
+                {9B36B6FE-7FC0-434F-A71F-BBEF8099F1D8}.Debug|Win32.ActiveCfg = Debug|Win32
+                {9B36B6FE-7FC0-434F-A71F-BBEF8099F1D8}.Debug|Win32.Build.0 = Debug|Win32
+                {9B36B6FE-7FC0-434F-A71F-BBEF8099F1D8}.Release Library|Win32.ActiveCfg = Release Library|Win32
+                {9B36B6FE-7FC0-434F-A71F-BBEF8099F1D8}.Release Library|Win32.Build.0 = Release Library|Win32
+                {9B36B6FE-7FC0-434F-A71F-BBEF8099F1D8}.Release|Win32.ActiveCfg = Release|Win32
+                {9B36B6FE-7FC0-434F-A71F-BBEF8099F1D8}.Release|Win32.Build.0 = Release|Win32
+                {EB33566E-DA7F-4D28-9077-88C0B7C77E35}.Debug Library|Win32.ActiveCfg = Release|Win32
+                {EB33566E-DA7F-4D28-9077-88C0B7C77E35}.Debug Library|Win32.Build.0 = Release|Win32
+                {EB33566E-DA7F-4D28-9077-88C0B7C77E35}.Debug|Win32.ActiveCfg = Release|Win32
+                {EB33566E-DA7F-4D28-9077-88C0B7C77E35}.Debug|Win32.Build.0 = Release|Win32
+                {EB33566E-DA7F-4D28-9077-88C0B7C77E35}.Release Library|Win32.ActiveCfg = Release|Win32
+                {EB33566E-DA7F-4D28-9077-88C0B7C77E35}.Release Library|Win32.Build.0 = Release|Win32
+                {EB33566E-DA7F-4D28-9077-88C0B7C77E35}.Release|Win32.ActiveCfg = Release|Win32
+                {EB33566E-DA7F-4D28-9077-88C0B7C77E35}.Release|Win32.Build.0 = Release|Win32
+                {277AC57F-313B-4D06-B119-A3CDB672D2FF}.Debug Library|Win32.ActiveCfg = Debug Library|Win32
+                {277AC57F-313B-4D06-B119-A3CDB672D2FF}.Debug Library|Win32.Build.0 = Debug Library|Win32
+                {277AC57F-313B-4D06-B119-A3CDB672D2FF}.Debug|Win32.ActiveCfg = Debug|Win32
+                {277AC57F-313B-4D06-B119-A3CDB672D2FF}.Debug|Win32.Build.0 = Debug|Win32
+                {277AC57F-313B-4D06-B119-A3CDB672D2FF}.Release Library|Win32.ActiveCfg = Release Library|Win32
+                {277AC57F-313B-4D06-B119-A3CDB672D2FF}.Release Library|Win32.Build.0 = Release Library|Win32
+                {277AC57F-313B-4D06-B119-A3CDB672D2FF}.Release|Win32.ActiveCfg = Release|Win32
+                {277AC57F-313B-4D06-B119-A3CDB672D2FF}.Release|Win32.Build.0 = Release|Win32
+        EndGlobalSection
+        GlobalSection(SolutionProperties) = preSolution
+                HideSolutionNode = FALSE
+        EndGlobalSection
+EndGlobal
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/projects/vstudio/zlib.props b/libraries/irrlicht-1.8/source/Irrlicht/libpng/projects/vstudio/zlib.props
new file mode 100644
index 0000000..eaec606
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/projects/vstudio/zlib.props
@@ -0,0 +1,37 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+ * zlib.props - location of zlib source
+ *
+ * libpng version 1.5.9 - February 18, 2012
+ *
+ * Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ * You must edit this file to record the location of the zlib
+ * source code.
+ -->
+<Project ToolsVersion="4.0"
+   xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <PropertyGroup Label="Globals">
+    <!-- Place the name of the directory containing the source of zlib used for
+         debugging in this property.
+         The directory need only contain the '.c' and '.h' files from the
+         source.
+         If you use a relative directory name (as below) then it must be
+         relative to the project directories; these are one level deepers than
+         the directories containing this file.
+         If the version of zlib you use does not match that used when the
+         distribution was built you will get warnings from pngtest that the zlib
+         versions do not match.  The zlib version used in this build is recorded
+         below:
+     -->
+    <ZLibSrcDir>..\..\..\..\zlib-1.2.5</ZLibSrcDir>
+  </PropertyGroup>
+</Project>
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/projects/vstudio/zlib/zlib.vcxproj b/libraries/irrlicht-1.8/source/Irrlicht/libpng/projects/vstudio/zlib/zlib.vcxproj
new file mode 100644
index 0000000..45dbeb5
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/projects/vstudio/zlib/zlib.vcxproj
@@ -0,0 +1,174 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <ItemGroup Label="ProjectConfigurations">
+    <ProjectConfiguration Include="Debug Library|Win32">
+      <Configuration>Debug Library</Configuration>
+      <Platform>Win32</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Debug|Win32">
+      <Configuration>Debug</Configuration>
+      <Platform>Win32</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Release Library|Win32">
+      <Configuration>Release Library</Configuration>
+      <Platform>Win32</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Release|Win32">
+      <Configuration>Release</Configuration>
+      <Platform>Win32</Platform>
+    </ProjectConfiguration>
+  </ItemGroup>
+  <ItemGroup>
+    <ClCompile Include="$(ZLibSrcDir)\adler32.c" />
+    <ClCompile Include="$(ZLibSrcDir)\compress.c" />
+    <ClCompile Include="$(ZLibSrcDir)\crc32.c" />
+    <ClCompile Include="$(ZLibSrcDir)\deflate.c" />
+    <ClCompile Include="$(ZLibSrcDir)\infback.c" />
+    <ClCompile Include="$(ZLibSrcDir)\inffast.c" />
+    <ClCompile Include="$(ZLibSrcDir)\inflate.c" />
+    <ClCompile Include="$(ZLibSrcDir)\inftrees.c" />
+    <ClCompile Include="$(ZLibSrcDir)\trees.c" />
+    <ClCompile Include="$(ZLibSrcDir)\uncompr.c" />
+    <ClCompile Include="$(ZLibSrcDir)\zutil.c" />
+  </ItemGroup>
+  <PropertyGroup Label="Globals">
+    <Keyword>Win32Proj</Keyword>
+  </PropertyGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
+  <Import Project="$(SolutionDir)\zlib.props" />
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug Library|Win32'" Label="Configuration">
+    <ConfigurationType>StaticLibrary</ConfigurationType>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" Label="Configuration">
+    <ConfigurationType>StaticLibrary</ConfigurationType>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release Library|Win32'" Label="Configuration">
+    <ConfigurationType>StaticLibrary</ConfigurationType>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'" Label="Configuration">
+    <ConfigurationType>StaticLibrary</ConfigurationType>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'" Label="Configuration">
+    <ConfigurationType>StaticLibrary</ConfigurationType>
+  </PropertyGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
+  <ImportGroup Label="ExtensionSettings">
+  </ImportGroup>
+  <ImportGroup Condition="'$(Configuration)|$(Platform)'=='Debug Library|Win32'" Label="PropertySheets">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" />
+  </ImportGroup>
+  <ImportGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" Label="PropertySheets">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" />
+  </ImportGroup>
+  <ImportGroup Condition="'$(Configuration)|$(Platform)'=='Release Library|Win32'" Label="PropertySheets">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" />
+  </ImportGroup>
+  <ImportGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'" Label="PropertySheets">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
+  </ImportGroup>
+  <PropertyGroup Label="UserMacros" />
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug Library|Win32'">
+    <LinkIncremental>true</LinkIncremental>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
+    <LinkIncremental>true</LinkIncremental>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release Library|Win32'">
+    <LinkIncremental>true</LinkIncremental>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
+    <LinkIncremental>true</LinkIncremental>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
+    <LinkIncremental>true</LinkIncremental>
+  </PropertyGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug Library|Win32'">
+    <ClCompile>
+      <PreprocessorDefinitions>WIN32;_DEBUG;_WINDOWS;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <RuntimeLibrary>MultiThreadedDebug</RuntimeLibrary>
+      <WarningLevel>TurnOffAllWarnings</WarningLevel>
+      <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
+      <Optimization>Disabled</Optimization>
+      <BrowseInformation>true</BrowseInformation>
+    </ClCompile>
+    <Link>
+      <TargetMachine>MachineX86</TargetMachine>
+      <GenerateDebugInformation>true</GenerateDebugInformation>
+      <SubSystem>Windows</SubSystem>
+    </Link>
+  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
+    <ClCompile>
+      <PreprocessorDefinitions>WIN32;_DEBUG;_WINDOWS;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <WarningLevel>TurnOffAllWarnings</WarningLevel>
+      <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
+      <Optimization>Disabled</Optimization>
+      <BrowseInformation>true</BrowseInformation>
+    </ClCompile>
+    <Link>
+      <TargetMachine>MachineX86</TargetMachine>
+      <GenerateDebugInformation>true</GenerateDebugInformation>
+      <SubSystem>Windows</SubSystem>
+    </Link>
+  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release Library|Win32'">
+    <ClCompile>
+      <WarningLevel>Level3</WarningLevel>
+      <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
+      <Optimization>Full</Optimization>
+      <IntrinsicFunctions>true</IntrinsicFunctions>
+      <WholeProgramOptimization>true</WholeProgramOptimization>
+      <BufferSecurityCheck>false</BufferSecurityCheck>
+      <BrowseInformation>true</BrowseInformation>
+      <FunctionLevelLinking>true</FunctionLevelLinking>
+      <TreatWarningAsError>true</TreatWarningAsError>
+      <RuntimeLibrary>MultiThreaded</RuntimeLibrary>
+    </ClCompile>
+    <Link>
+      <TargetMachine>MachineX86</TargetMachine>
+      <GenerateDebugInformation>true</GenerateDebugInformation>
+      <SubSystem>Windows</SubSystem>
+    </Link>
+    <Lib>
+      <LinkTimeCodeGeneration>true</LinkTimeCodeGeneration>
+    </Lib>
+  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
+    <ClCompile>
+      <WarningLevel>Level3</WarningLevel>
+      <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
+      <Optimization>Full</Optimization>
+      <IntrinsicFunctions>true</IntrinsicFunctions>
+      <WholeProgramOptimization>true</WholeProgramOptimization>
+      <BufferSecurityCheck>false</BufferSecurityCheck>
+      <BrowseInformation>true</BrowseInformation>
+      <FunctionLevelLinking>true</FunctionLevelLinking>
+      <TreatWarningAsError>true</TreatWarningAsError>
+    </ClCompile>
+    <Link>
+      <TargetMachine>MachineX86</TargetMachine>
+      <GenerateDebugInformation>true</GenerateDebugInformation>
+      <SubSystem>Windows</SubSystem>
+    </Link>
+    <Lib>
+      <LinkTimeCodeGeneration>true</LinkTimeCodeGeneration>
+    </Lib>
+  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
+    <ClCompile>
+      <PreprocessorDefinitions>WIN32;NDEBUG;_WINDOWS;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <WarningLevel>Level3</WarningLevel>
+      <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
+    </ClCompile>
+    <Link>
+      <TargetMachine>MachineX86</TargetMachine>
+      <GenerateDebugInformation>true</GenerateDebugInformation>
+      <SubSystem>Windows</SubSystem>
+      <EnableCOMDATFolding>true</EnableCOMDATFolding>
+      <OptimizeReferences>true</OptimizeReferences>
+    </Link>
+  </ItemDefinitionGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
+  <ImportGroup Label="ExtensionTargets">
+  </ImportGroup>
+</Project>
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/README.txt b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/README.txt
new file mode 100644
index 0000000..e0a229f
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/README.txt
@@ -0,0 +1,76 @@
+Makefiles for  libpng version 1.5.9 - February 18, 2012
+pnglibconf.h.prebuilt       =>  Stores configuration settings
+ makefile.linux    =>  Linux/ELF makefile
+                       (gcc, creates libpng15.so.15.1.5.9)
+ makefile.gcc      =>  Generic makefile (gcc, creates static libpng.a)
+ makefile.knr      =>  Archaic UNIX Makefile that converts files with
+                       ansi2knr (Requires ansi2knr.c from
+                       ftp://ftp.cs.wisc.edu/ghost)
+ makefile.acorn    =>  Acorn makefile
+ makefile.aix      =>  AIX/gcc makefile
+ makefile.amiga    =>  Amiga makefile
+ makefile.atari    =>  Atari makefile
+ makefile.bc32     =>  32-bit Borland C++ (all modules compiled in C mode)
+ makefile.beos     =>  beos makefile
+ makefile.bor      =>  Borland makefile (uses bcc)
+ makefile.cegcc    =>  minge32ce for Windows CE makefile
+ makefile.darwin   =>  Darwin makefile, can use on MacosX
+ makefile.dec      =>  DEC Alpha UNIX makefile
+ makefile.dj2      =>  DJGPP 2 makefile
+ makefile.elf      =>  Linux/ELF makefile symbol versioning,
+                       (gcc, creates libpng15.so.15.1.5.9)
+ makefile.freebsd  =>  FreeBSD makefile
+ makefile.gcc      =>  Generic gcc makefile
+ makefile.hpgcc    =>  HPUX makefile using gcc
+ makefile.hpux     =>  HPUX (10.20 and 11.00) makefile
+ makefile.hp64     =>  HPUX (10.20 and 11.00) makefile, 64-bit
+ makefile.ibmc     =>  IBM C/C++ version 3.x for Win32 and OS/2 (static)
+ makefile.intel    =>  Intel C/C++ version 4.0 and later
+ makefile.mips     =>  MIPS makefile
+ makefile.msc      =>  Microsoft C makefile
+ makefile.netbsd   =>  NetBSD/cc makefile, makes libpng.so.
+ makefile.openbsd  =>  OpenBSD makefile
+ makefile.os2      =>  OS/2 Makefile (gcc and emx, requires libpng.def)
+ makefile.sco      =>  For SCO OSr5  ELF and Unixware 7 with Native cc
+ makefile.sggcc    =>  Silicon Graphics (gcc,
+                       creates libpng15.so.15.1.5.9)
+ makefile.sgi      =>  Silicon Graphics IRIX makefile (cc, creates static lib)
+ makefile.solaris  =>  Solaris 2.X makefile (gcc,
+                       creates libpng15.so.15.1.5.9)
+ makefile.so9      =>  Solaris 9 makefile (gcc,
+                       creates libpng15.so.15.1.5.9)
+ makefile.std      =>  Generic UNIX makefile (cc, creates static libpng.a)
+ makefile.sunos    =>  Sun makefile
+ makefile.32sunu   =>  Sun Ultra 32-bit makefile
+ makefile.64sunu   =>  Sun Ultra 64-bit makefile
+ makefile.tc3      =>  Turbo C 3.0 makefile
+ makefile.vcwin32  =>  makefile for Microsoft Visual C++ 4.0 and later
+ makevms.com       =>  VMS build script
+ smakefile.ppc     =>  AMIGA smakefile for SAS C V6.58/7.00 PPC compiler
+                       (Requires SCOPTIONS, copied from scripts/SCOPTIONS.ppc)
+Other supporting scripts:
+ README.txt        =>  This file
+ descrip.mms       =>  VMS makefile for MMS or MMK
+ libpng-config-body.in => used by several makefiles to create libpng-config
+ libpng-config-head.in => used by several makefiles to create libpng-config
+ libpng.pc.in      =>  Used by several makefiles to create libpng.pc
+ pngwin.rc         =>  Used by the visualc71 project.
+ pngwin.def        =>  Used by makefile.os2
+ pngwin.dfn        =>  Used to maintain pngwin.def
+ SCOPTIONS.ppc     =>  Used with smakefile.ppc
+checksym.awk       =>  Used for maintaining pnglibconf.h
+def.dfn            =>  Used for maintaining pnglibconf.h
+options.awk        =>  Used for maintaining pnglibconf.h
+pnglibconf.dfa     =>  Used for maintaining pnglibconf.h
+pnglibconf.mak     =>  Used for maintaining pnglibconf.h
+sym.dfn            =>  Used for symbol versioning
+symbols.def        =>  Used for symbol versioning
+symbols.dfn        =>  Used for symbol versioning
+vers.dfn           =>  Used for symbol versioning
+Further information can be found in comments in the individual makefiles.
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/SCOPTIONS.ppc b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/SCOPTIONS.ppc
new file mode 100644
index 0000000..7090fd4
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/SCOPTIONS.ppc
@@ -0,0 +1,7 @@
+OPTIMIZE
+OPTPEEP
+OPTTIME
+OPTSCHED
+AUTOREGISTER
+PARMS=REGISTERS
+INCLUDEDIR=hlp:ppc/include
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/checksym.awk b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/checksym.awk
new file mode 100644
index 0000000..5bafa8c
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/checksym.awk
@@ -0,0 +1,161 @@
+#!/bin/awk -f
+# Check a list of symbols against the master definition
+# (official) list.  Arguments:
+#
+# awk -f checksym.awk official-def list-to-check
+#
+# Output is a file in the current directory called 'symbols.new',
+# stdout holds error messages.  Error code indicates success or
+# failure.
+#
+# NOTE: this is a pure, old fashioned, awk script.  It will
+# work with any awk
+BEGIN{
+   err=0
+   master=""        # master file
+   official[1] = "" # defined symbols from master file
+   symbol[1] = ""   # defined symbols from png.h
+   removed[1] = ""  # removed symbols from png.h
+   lasto = 0        # last ordinal value from png.h
+   mastero = 0      # highest ordinal in master file
+   symbolo = 0      # highest ordinal in png.h
+   missing = "error"# log an error on missing symbols
+}
+# Read existing definitions from the master file (the first
+# file on the command line.)  This must be a def file and it
+# has definition lines (others are ignored) of the form:
+#
+#   symbol @ordinal
+#
+master == "" {
+   master = FILENAME
+}
+FILENAME==master && NF==2 && $2~/^@/ && $1!~/^;/ {
+   o=0+substr($2,2)
+   if (o > 0) {
+      if (official[o] == "") {
+         official[o] = $1
+         if (o > mastero) mastero = o
+         next
+      } else
+         print master ": duplicated symbol:", official[o] ":", $0
+   } else
+      print master ": bad export line format:", $0
+   err = 1
+}
+FILENAME==master && $1==";missing" && NF==2{
+   # This allows the master file to control how missing symbols
+   # are handled; symbols that aren't in either the master or
+   # the new file.  Valid values are 'ignore', 'warning' and
+   # 'error'
+   missing = $2
+}
+FILENAME==master {
+   next
+}
+# Read new definitions, these are free form but the lines must
+# just be symbol definitions.  Lines will be commented out for
+# 'removed' symbols, introduced in png.h using PNG_REMOVED rather
+# than PNG_EXPORT.  Use symbols.dfn or pngwin.dfn to generate the
+# input file.
+#
+#  symbol @ordinal   # two fields, exported symbol
+#  ; symbol @ordinal # three fields, removed symbol
+#  ; @ordinal        # two fields, the last ordinal
+NF==2 && $1 == ";" && $2 ~ /^@[1-9][0-9]*$/ { # last ordinal
+   o=0+substr($2,2)
+   if (lasto == 0 || lasto == o)
+      lasto=o
+   else {
+      print "png.h: duplicated last ordinal:", lasto, o
+      err = 1
+   }
+   next
+}
+NF==3 && $1 == ";" && $3 ~ /^@[1-9][0-9]*$/ { # removed symbol
+   o=0+substr($3,2)
+   if (removed[o] == "" || removed[o] == $2) {
+      removed[o] = $2
+      if (o > symbolo) symbolo = o
+   } else {
+      print "png.h: duplicated removed symbol", o ": '" removed[o] "' != '" $2 "'"
+      err = 1
+   }
+   next
+}
+NF==2 && $2 ~ /^@[1-9][0-9]*$/ { # exported symbol
+   o=0+substr($2,2)
+   if (symbol[o] == "" || symbol[o] == $1) {
+      symbol[o] = $1
+      if (o > symbolo) symbolo = o
+   } else {
+      print "png.h: duplicated symbol", o ": '" symbol[o] "' != '" $1 "'"
+      err = 1
+   }
+}
+{
+   next # skip all other lines
+}
+# At the end check for symbols marked as both duplicated and removed
+END{
+   if (symbolo > lasto) {
+      print "highest symbol ordinal in png.h,", symbolo ", exceeds last ordinal from png.h", lasto
+      err = 1
+   }
+   if (mastero > lasto) {
+      print "highest symbol ordinal in", master ",", mastero ", exceeds last ordinal from png.h", lasto
+      err = 1
+   }
+   unexported=0
+   for (o=1; o<=lasto; ++o) {
+      if (symbol[o] == "" && removed[o] == "") {
+         if (unexported == 0) unexported = o
+         if (official[o] == "") {
+            # missing in export list too, so ok
+            if (o < lasto) continue
+         }
+      }
+      if (unexported != 0) {
+         # Symbols in the .def but not in the new file are errors, but
+         # the 'unexported' symbols aren't in either.  By default this
+         # is an error too (see the setting of 'missing' at the start),
+         # but this can be reset on the command line or by stuff in the
+         # file - see the comments above.
+         if (missing != "ignore") {
+            if (o-1 > unexported)
+               print "png.h:", missing ": missing symbols:", unexported "-" o-1
+            else
+               print "png.h:", missing ": missing symbol:", unexported
+            if (missing != "warning")
+               err = 1
+         }
+         unexported = 0
+      }
+      if (symbol[o] != "" && removed[o] != "") {
+         print "png.h: symbol", o, "both exported as '" symbol[o] "' and removed as '" removed[o] "'"
+         err = 1
+      } else if (symbol[o] != official[o]) {
+         # either the symbol is missing somewhere or it changed
+         err = 1
+         if (symbol[o] == "")
+            print "png.h: symbol", o, "is exported as '" official[o] "' in", master
+         else if (official[o] == "")
+            print "png.h: exported symbol", o, "'" symbol[o] "' not present in", master
+         else
+            print "png.h: exported symbol", o, "'" symbol[o] "' exists as '" official[o] "' in", master
+      }
+      # Finally generate symbols.new
+      if (symbol[o] != "")
+         print " " symbol[o], "@" o > "symbols.new"
+   }
+   if (err != 0) {
+      print "*** A new list is in symbols.new ***"
+      exit 1
+   }
+}
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/chkfmt b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/chkfmt
new file mode 100644
index 0000000..80b4917
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/chkfmt
@@ -0,0 +1,137 @@
+#!/bin/sh
+#
+# Check the format of the source files in the current directory - checks for a
+# line length of 80 characters max and no tab characters.
+#
+# Optionally arguments are files or directories to check.
+#
+# -v: output the long lines (makes fixing them easier)
+# -e: spawn an editor for each file that needs a change ($EDITOR must be
+#     defined).  When using -e the script MUST be run from an interactive
+#     command line.
+verbose=
+edit=
+vers=
+test "$1" = "-v" && {
+   shift
+   verbose=yes
+}
+test "$1" = "-e" && {
+   shift
+   if test -n "$EDITOR"
+   then
+      edit=yes
+      # Copy the standard streams for the editor
+      exec 3>&0 4>&1 5>&2
+   else
+      echo "chkfmt -e: EDITOR must be defined" >&2
+      exit 1
+   fi
+}
+# Function to edit a single file - if the file isn't changed ask the user
+# whether or not to continue.  This stuff only works if the script is run from
+# the command line (otherwise, don't specify -e or you will be sorry).
+doed(){
+   cp "$file" "$file".orig
+   "$EDITOR" "$file" 0>&3 1>&4 2>&5 3>&- 4>&- 5>&- || exit 1
+   if cmp -s "$file".orig "$file"
+   then
+      rm "$file".orig
+      echo -n "$file: file not changed, type anything to continue: " >&5
+      read ans 0>&3
+      test -n "$ans" || return 1
+   fi
+   return 0
+}
+# In beta versions the version string which appears in files can be a little
+# long and cause spuriously overlong lines.  To avoid this subtitute the version
+# string with a 'standard' version a.b.cc before checking for long lines.
+if test -r png.h
+then
+   vers="`sed -n -e \
+   's/^#define PNG_LIBPNG_VER_STRING .\([0-9]\.[0-9]\.[0-9][0-9a-z]*\).$/\1/p' \
+   png.h`"
+   echo "chkfmt: checking version $vers"
+fi
+if test -z "$vers"
+then
+   echo "chkfmt: png.h not found, ignoring version number" >&2
+fi
+test -n "$1" || set -- .
+find "$@" \( -type d \( -name '.git' -o -name '.libs' -o -name 'projects' \) \
+   -prune \) -o \( -type f \
+   ! -name '*.[oa]' ! -name '*.l[oa]' !  -name '*.png' ! -name '*.out' \
+   ! -name '*.jpg' ! -name '*.patch' ! -name '*.obj' ! -name '*.exe' \
+   ! -name '*.com' ! -name '*.tar.*' ! -name '*.zip' ! -name '*.ico' \
+   ! -name '*.res' ! -name '*.rc' ! -name '*.mms' ! -name '*.rej' \
+   ! -name '*.dsp' ! -name '*.orig' ! -name '*.dfn' ! -name '*.swp' \
+   ! -name '~*' ! -name '*.3' \
+   ! -name 'missing' ! -name 'mkinstalldirs' ! -name 'depcomp' \
+   ! -name 'aclocal.m4' ! -name 'install-sh' ! -name 'Makefile.in' \
+   ! -name 'ltmain.sh' ! -name 'config*' -print \) | {
+   st=0
+   while read file
+   do
+      case "$file" in
+      *.mak|*[Mm]akefile.*|*[Mm]akefile)
+         # Makefiles require tabs, dependency lines can be this long.
+         check_tabs=
+         line_length=100;;
+      *.awk)
+         # Includes literal tabs
+         check_tabs=
+         # The following is arbitrary
+         line_length=132;;
+      *contrib/*/*.[ch])
+         check_tabs=yes
+         line_length=96;;
+      *)
+         check_tabs=yes
+         line_length=80;;
+      esac
+      # Note that vers can only contain 0-9, . and a-z
+      if test -n "$vers"
+      then
+         sed -e "s/$vers/a.b.cc/g" "$file" >"$file".$$
+      else
+         cp "$file" "$file".$$
+      fi
+      splt="`fold -$line_length "$file".$$ | diff -c "$file".$$ -`"
+      rm "$file".$$
+      if test -n "$splt"
+      then
+         echo "$file: lines too long"
+         st=1
+         if test -n "$EDITOR" -a -n "$edit"
+         then
+            doed "$file" || exit 1
+         elif test -n "$verbose"
+         then
+            echo "$splt"
+         fi
+      fi
+      if test -n "$check_tabs"
+      then
+         tab="`tr -c -d '\t' <"$file"`"
+         if test -n "$tab"
+         then
+            echo "$file: file contains tab characters"
+            st=1
+            if test -n "$EDITOR" -a -n "$edit"
+            then
+               doed "$file" || exit 1
+            elif test -n "$verbose"
+            then
+               echo "$splt"
+            fi
+         fi
+      fi
+   done
+   exit $st
+}
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/def.dfn b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/def.dfn
new file mode 100644
index 0000000..c7ed8ab
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/def.dfn
@@ -0,0 +1,38 @@
+/* def.dfn - define format of libpng.def
+ *
+ * Last changed in libpng version 1.5.7 [December 15, 2011]
+ * Copyright (c) 2010-2011 Glenn Randers-Pehrson
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+/* These macros exist to make the header and trailer shorter below: */
+#define S PNG_DEFN_MAGIC
+#define E PNG_DEFN_END
+/* Write the export file header: */
+S-;---------------------------------------------------------------E
+S-; LIBPNG module definition file for OS/2-E
+S-;---------------------------------------------------------------E
+S--E
+S-; If you give the library an explicit name one or other files-E
+S-; may need modifying to support the new name on one or more-E
+S-; systems.-E
+S-LIBRARY-E
+S-OS2 DESCRIPTION "PNG image compression library"-E
+S-OS2 CODE PRELOAD MOVEABLE DISCARDABLE-E
+S--E
+S-EXPORTS-E
+S-;Version 1.5.0beta58-E
+/* NOTE: PNG_JOIN is interpreted by the calling script as a signal to
+ * join the two things on either side, so we can do symbol
+ * substitution within the name, regular C ## joins the pp-tokens,
+ * not their final values.
+ */
+#define PNG_EXPORTA(ordinal, type, name, args, attributes)\
+        PNG_DEFN_MAGIC- SYMBOL_PREFIX PNG_JOIN name-PNG_DEFN_END
+#include "../png.h"
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/descrip.mms b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/descrip.mms
new file mode 100644
index 0000000..9ba2d5f
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/descrip.mms
@@ -0,0 +1,52 @@
+cc_defs = /inc=$(ZLIBSRC)
+c_deb =
+.ifdef __DECC__
+pref = /prefix=all
+.endif
+OBJS = png.obj, pngset.obj, pngget.obj, pngrutil.obj, pngtrans.obj,\
+        pngwutil.obj, pngread.obj, pngmem.obj, pngwrite.obj, pngrtran.obj,\
+        pngwtran.obj, pngrio.obj, pngwio.obj, pngerror.obj, pngpread.obj
+CFLAGS= $(C_DEB) $(CC_DEFS) $(PREF)
+all : pngtest.exe libpng.olb
+                @ write sys$output " pngtest available"
+libpng.olb : libpng.olb($(OBJS))
+        @ write sys$output " Libpng available"
+pngtest.exe : pngtest.obj libpng.olb
+              link pngtest,libpng.olb/lib,$(ZLIBSRC)libz.olb/lib
+test : pngtest.exe
+   run pngtest
+clean :
+        delete *.obj;*,*.exe;
+# Other dependencies.
+png.obj : png.h, pngconf.h, pnglibconf.h, pngpriv.h, pngstruct.h, pnginfo.h, pngdebug.h
+pngpread.obj : png.h, pngconf.h, pnglibconf.h, pngpriv.h, pngstruct.h, pnginfo.h, pngdebug.h
+pngset.obj : png.h, pngconf.h, pnglibconf.h, pngpriv.h, pngstruct.h, pnginfo.h, pngdebug.h
+pngget.obj : png.h, pngconf.h, pnglibconf.h, pngpriv.h, pngstruct.h, pnginfo.h, pngdebug.h
+pngread.obj : png.h, pngconf.h, pnglibconf.h, pngpriv.h, pngstruct.h, pnginfo.h, pngdebug.h
+pngrtran.obj : png.h, pngconf.h, pnglibconf.h, pngpriv.h, pngstruct.h, pnginfo.h, pngdebug.h
+pngrutil.obj : png.h, pngconf.h, pnglibconf.h, pngpriv.h, pngstruct.h, pnginfo.h, pngdebug.h
+pngerror.obj : png.h, pngconf.h, pnglibconf.h, pngpriv.h, pngstruct.h, pnginfo.h, pngdebug.h
+pngmem.obj : png.h, pngconf.h, pnglibconf.h, pngpriv.h, pngstruct.h, pnginfo.h, pngdebug.h
+pngrio.obj : png.h, pngconf.h, pnglibconf.h, pngpriv.h, pngstruct.h, pnginfo.h, pngdebug.h
+pngwio.obj : png.h, pngconf.h, pnglibconf.h, pngpriv.h, pngstruct.h, pnginfo.h, pngdebug.h
+pngtrans.obj : png.h, pngconf.h, pnglibconf.h, pngpriv.h, pngstruct.h, pnginfo.h, pngdebug.h
+pngwrite.obj : png.h, pngconf.h, pnglibconf.h, pngpriv.h, pngstruct.h, pnginfo.h, pngdebug.h
+pngwtran.obj : png.h, pngconf.h, pnglibconf.h, pngpriv.h, pngstruct.h, pnginfo.h, pngdebug.h
+pngwutil.obj : png.h, pngconf.h, pnglibconf.h, pngpriv.h, pngstruct.h, pnginfo.h, pngdebug.h
+pngtest.obj : png.h, pngconf.h
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/libpng-config-body.in b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/libpng-config-body.in
new file mode 100644
index 0000000..0db8898
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/libpng-config-body.in
@@ -0,0 +1,96 @@
+usage()
+{
+    cat <<EOF
+Usage: libpng-config [OPTION] ...
+Known values for OPTION are:
+  --prefix        print libpng prefix
+  --libdir        print path to directory containing library
+  --libs          print library linking information
+  --ccopts        print compiler options
+  --cppflags      print pre-processor flags
+  --cflags        print preprocessor flags, I_opts, and compiler options
+  --I_opts        print "-I" include options
+  --L_opts        print linker "-L" flags for dynamic linking
+  --R_opts        print dynamic linker "-R" or "-rpath" flags
+  --ldopts        print linker options
+  --ldflags       print linker flags (ldopts, L_opts, R_opts, and libs)
+  --static        revise subsequent outputs for static linking
+  --help          print this help and exit
+  --version       print version information
+EOF
+    exit $1
+}
+if test $# -eq 0; then
+    usage 1
+fi
+while test $# -gt 0; do
+    case "$1" in
+    --prefix)
+        echo ${prefix}
+        ;;
+    --version)
+        echo ${version}
+        exit 0
+        ;;
+    --help)
+        usage 0
+        ;;
+    --ccopts)
+        echo ${ccopts}
+        ;;
+    --cppflags)
+        echo ${cppflags}
+        ;;
+    --cflags)
+        echo ${I_opts} ${cppflags} ${ccopts}
+        ;;
+    --libdir)
+        echo ${libdir}
+        ;;
+    --libs)
+        echo ${libs}
+        ;;
+    --I_opts)
+        echo ${I_opts}
+        ;;
+    --L_opts)
+        echo ${L_opts}
+        ;;
+    --R_opts)
+        echo ${R_opts}
+        ;;
+    --ldflags)
+        echo ${ldflags} ${L_opts} ${R_opts} ${libs}
+        ;;
+    --static)
+        R_opts=""
+        ;;
+    *)
+        usage
+        exit 1
+        ;;
+    esac
+    shift
+done
+exit 0
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/libpng-config-head.in b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/libpng-config-head.in
new file mode 100644
index 0000000..154bb39
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/libpng-config-head.in
@@ -0,0 +1,24 @@
+#! /bin/sh
+# libpng-config
+# provides configuration info for libpng.
+# Copyright (C) 2002 Glenn Randers-Pehrson
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+# Modeled after libxml-config.
+version=1.5.9
+prefix=""
+libdir=""
+libs=""
+I_opts=""
+L_opts=""
+R_opts=""
+cppflags=""
+ccopts=""
+ldopts=""
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/libpng.pc.in b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/libpng.pc.in
new file mode 100644
index 0000000..2f647c2
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/libpng.pc.in
@@ -0,0 +1,10 @@
+prefix=@prefix@
+exec_prefix=@exec_prefix@
+libdir=@libdir@
+includedir=@includedir@/libpng15
+Name: libpng
+Description: Loads and saves PNG files
+Version: 1.5.9
+Libs: -L${libdir} -lpng15
+Cflags: -I${includedir}
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.32sunu b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.32sunu
new file mode 100644
index 0000000..a6279ad
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.32sunu
@@ -0,0 +1,241 @@
+# makefile for libpng on Solaris 2.x with cc
+# Contributed by William L. Sebok, based on makefile.linux
+# Copyright (C) 2002, 2006, 2010-2011 Glenn Randers-Pehrson
+# Copyright (C) 1998 Greg Roelofs
+# Copyright (C) 1996, 1997 Andreas Dilger
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+# Library name:
+LIBNAME=libpng15
+PNGMAJ = 15
+# Shared library names:
+LIBSO=$(LIBNAME).so
+LIBSOMAJ=$(LIBNAME).so.$(PNGMAJ)
+LIBSOREL=$(LIBSOMAJ).$(RELEASE)
+OLDSO=libpng.so
+# Utilities:
+CC=cc
+AR_RC=ar rc
+MKDIR_P=mkdir -p
+LN_SF=ln -f -s
+RANLIB=echo
+RM_F=/bin/rm -f
+SUN_CC_FLAGS=-fast -xtarget=ultra
+SUN_LD_FLAGS=-fast -xtarget=ultra
+# where make install puts libpng.a, libpng15.so and libpng15/png.h
+prefix=/a
+exec_prefix=$(prefix)
+# Where the zlib library and include files are located
+# Changing these to ../zlib poses a security risk.  If you want
+# to have zlib in an adjacent directory, specify the full path instead of "..".
+#ZLIBLIB=../zlib
+#ZLIBINC=../zlib
+ZLIBLIB=/usr/lib
+ZLIBINC=/usr/include
+WARNMORE=-Wwrite-strings -Wpointer-arith -Wshadow \
+        -Wmissing-declarations -Wtraditional -Wcast-align \
+        -Wstrict-prototypes -Wmissing-prototypes #-Wconversion
+CFLAGS=-I$(ZLIBINC) $(SUN_CC_FLAGS) \
+        # $(WARNMORE) -g -DPNG_DEBUG=5
+LDFLAGS=$(SUN_LD_FLAGS) -L$(ZLIBLIB) -R$(ZLIBLIB) libpng.a -lz -lm
+INCPATH=$(prefix)/include
+LIBPATH=$(exec_prefix)/lib
+MANPATH=$(prefix)/man
+BINPATH=$(exec_prefix)/bin
+# override DESTDIR= on the make install command line to easily support
+# installing into a temporary location.  Example:
+#
+#    make install DESTDIR=/tmp/build/libpng
+#
+# If you're going to install into a temporary location
+# via DESTDIR, $(DESTDIR)$(prefix) must already exist before
+# you execute make install.
+DESTDIR=
+DB=$(DESTDIR)$(BINPATH)
+DI=$(DESTDIR)$(INCPATH)
+DL=$(DESTDIR)$(LIBPATH)
+DM=$(DESTDIR)$(MANPATH)
+OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
+        pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
+        pngwtran.o pngmem.o pngerror.o pngpread.o
+OBJSDLL = $(OBJS:.o=.pic.o)
+.SUFFIXES:      .c .o .pic.o
+.c.pic.o:
+        $(CC) -c $(CFLAGS) -KPIC -o $@ $*.c
+all: libpng.a $(LIBSO) pngtest libpng.pc libpng-config
+include scripts/pnglibconf.mak
+DELETE = $(RM_F)
+DFNFLAGS = $(DEFS) $(CPPFLAGS)
+libpng.a: $(OBJS)
+        $(AR_RC) $@ $(OBJS)
+        $(RANLIB) $@
+libpng.pc:
+        cat scripts/libpng.pc.in | sed -e s!@prefix@!$(prefix)! \
+        -e s!@exec_prefix@!$(exec_prefix)! \
+        -e s!@libdir@!$(LIBPATH)! \
+        -e s!@includedir@!$(INCPATH)! \
+        -e s!-lpng15!-lpng15\ -lz\ -lm! > libpng.pc
+libpng-config:
+        ( cat scripts/libpng-config-head.in; \
+        echo prefix=\"$(prefix)\"; \
+        echo libdir=\"$(LIBPATH)\"; \
+        echo I_opts=\"-I$(INCPATH)/$(LIBNAME)\"; \
+        echo L_opts=\"-L$(LIBPATH)\"; \
+        echo R_opts=\"-R$(LIBPATH)\"; \
+        echo ccopts=\"-xtarget=ultra\"; \
+        echo ldopts=\"-xtarget=ultra\"; \
+        echo libs=\"-lpng15 -lz -lm\"; \
+        cat scripts/libpng-config-body.in ) > libpng-config
+        chmod +x libpng-config
+$(LIBSO): $(LIBSOMAJ)
+        $(LN_SF) $(LIBSOMAJ) $(LIBSO)
+$(LIBSOMAJ): $(OBJSDLL)
+        @case "`type ld`" in *ucb*) \
+        echo; \
+        echo '## WARNING:'; \
+        echo '## The commands "CC" and "LD" must NOT refer to /usr/ucb/cc'; \
+        echo '## and /usr/ucb/ld.  If they do, you need to adjust your PATH'; \
+        echo '## environment variable to put /usr/ccs/bin ahead of /usr/ucb.'; \
+        echo '## The environment variable LD_LIBRARY_PATH should not be set'; \
+        echo '## at all.  If it is, things are likely to break because of'; \
+        echo '## the libucb dependency that is created.'; \
+        echo; \
+        ;; \
+        esac
+        $(LD) -G -L$(ZLIBLIB) -R$(ZLIBLIB) -h $(LIBSOMAJ) \
+         -o $(LIBSOMAJ) $(OBJSDLL)
+pngtest: pngtest.o $(LIBSO)
+        $(CC) -o pngtest $(CFLAGS) pngtest.o $(LDFLAGS)
+test: pngtest
+        ./pngtest
+install-headers: png.h pngconf.h pnglibconf.h
+        -@if [ ! -d $(DI) ]; then $(MKDIR_P) $(DI); fi
+        -@if [ ! -d $(DI)/$(LIBNAME) ]; then $(MKDIR_P) $(DI)/$(LIBNAME); fi
+        cp png.h pngconf.h pnglibconf.h $(DI)/$(LIBNAME)
+        chmod 644 $(DI)/$(LIBNAME)/png.h $(DI)/$(LIBNAME)/pngconf.h $(DI)/$(LIBNAME)/pnglibconf.h
+        -@$(RM_F) $(DI)/png.h $(DI)/pngconf.h $(DI)/pnglibconf.h
+        -@$(RM_F) $(DI)/libpng
+        (cd $(DI); $(LN_SF) $(LIBNAME) libpng; $(LN_SF) $(LIBNAME)/* .)
+install-static: install-headers libpng.a
+        -@if [ ! -d $(DL) ]; then $(MKDIR_P) $(DL); fi
+        cp libpng.a $(DL)/$(LIBNAME).a
+        chmod 644 $(DL)/$(LIBNAME).a
+        -@$(RM_F) $(DL)/libpng.a
+        (cd $(DL); $(LN_SF) $(LIBNAME).a libpng.a)
+install-shared: install-headers $(LIBSOMAJ) libpng.pc
+        -@if [ ! -d $(DL) ]; then $(MKDIR_P) $(DL); fi
+        -@$(RM_F) $(DL)/$(LIBSO)
+        -@$(RM_F) $(DL)/$(LIBSOREL)
+        -@$(RM_F) $(DL)/$(OLDSO)
+        cp $(LIBSOMAJ) $(DL)/$(LIBSOREL)
+        chmod 755 $(DL)/$(LIBSOREL)
+        (cd $(DL); \
+        $(LN_SF) $(LIBSOREL) $(LIBSO); \
+        $(LN_SF) $(LIBSO) $(OLDSO))
+        -@if [ ! -d $(DL)/pkgconfig ]; then $(MKDIR_P) $(DL)/pkgconfig; fi
+        -@$(RM_F) $(DL)/pkgconfig/$(LIBNAME).pc
+        -@$(RM_F) $(DL)/pkgconfig/libpng.pc
+        cp libpng.pc $(DL)/pkgconfig/$(LIBNAME).pc
+        chmod 644 $(DL)/pkgconfig/$(LIBNAME).pc
+        (cd $(DL)/pkgconfig; $(LN_SF) $(LIBNAME).pc libpng.pc)
+install-man: libpng.3 libpngpf.3 png.5
+        -@if [ ! -d $(DM) ]; then $(MKDIR_P) $(DM); fi
+        -@if [ ! -d $(DM)/man3 ]; then $(MKDIR_P) $(DM)/man3; fi
+        -@$(RM_F) $(DM)/man3/libpng.3
+        -@$(RM_F) $(DM)/man3/libpngpf.3
+        cp libpng.3 $(DM)/man3
+        cp libpngpf.3 $(DM)/man3
+        -@if [ ! -d $(DM)/man5 ]; then $(MKDIR_P) $(DM)/man5; fi
+        -@$(RM_F) $(DM)/man5/png.5
+        cp png.5 $(DM)/man5
+install-config: libpng-config
+        -@if [ ! -d $(DB) ]; then $(MKDIR_P) $(DB); fi
+        -@$(RM_F) $(DB)/libpng-config
+        -@$(RM_F) $(DB)/$(LIBNAME)-config
+        cp libpng-config $(DB)/$(LIBNAME)-config
+        chmod 755 $(DB)/$(LIBNAME)-config
+        (cd $(DB); $(LN_SF) $(LIBNAME)-config libpng-config)
+install: install-static install-shared install-man install-config
+# If you installed in $(DESTDIR), test-installed won't work until you
+# move the library to its final location.  Use test-dd to test it
+# before then.
+test-dd:
+        echo
+        echo Testing installed dynamic shared library in $(DL).
+        $(CC) $(SUN_CC_FLAGS) -I$(DI) -I$(ZLIBINC) \
+           `$(BINPATH)/$(LIBNAME)-config --cflags` pngtest.c \
+           -o pngtestd -L$(DL) -R$(DL) `$(BINPATH)/$(LIBNAME)-config --ldflags` \
+           $(SUN_LD_FLAGS) -L$(ZLIBLIB) -R$(ZLIBLIB)
+        ./pngtestd pngtest.png
+test-installed:
+        echo
+        echo Testing installed dynamic shared library.
+        $(CC) $(SUN_CC_FLAGS) -I$(ZLIBINC) \
+           `$(BINPATH)/$(LIBNAME)-config --cflags` pngtest.c \
+           -o pngtesti `$(BINPATH)/$(LIBNAME)-config --ldflags` \
+           $(SUN_LD_FLAGS) -L$(ZLIBLIB) -R$(ZLIBLIB)
+        ./pngtesti pngtest.png
+clean:
+        $(RM_F) *.o libpng.a pngtest pngtesti pngout.png \
+        libpng-config $(LIBSO) $(LIBSOMAJ)* \
+        libpng.pc
+DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
+writelock:
+        chmod a-w *.[ch35] $(DOCS) scripts/*
+# DO NOT DELETE THIS LINE -- make depend depends on it.
+png.o png.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngerror.o pngerror.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrio.o pngrio.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwio.o pngwio.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngmem.o pngmem.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngset.o pngset.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngget.o pngget.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngread.o pngread.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrtran.o pngrtran.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrutil.o pngrutil.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtrans.o pngtrans.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwrite.o pngwrite.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwtran.o pngwtran.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwutil.o pngwutil.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngpread.o pngpread.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtest.o: png.h pngconf.h pnglibconf.h
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.64sunu b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.64sunu
new file mode 100644
index 0000000..5a5195d
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.64sunu
@@ -0,0 +1,241 @@
+# makefile for libpng on Solaris 2.x with cc
+# Contributed by William L. Sebok, based on makefile.linux
+# Copyright (C) 2002, 2006, 2010-2011 Glenn Randers-Pehrson
+# Copyright (C) 1998 Greg Roelofs
+# Copyright (C) 1996, 1997 Andreas Dilger
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+# Library name:
+LIBNAME=libpng15
+PNGMAJ = 15
+# Shared library names:
+LIBSO=$(LIBNAME).so
+LIBSOMAJ=$(LIBNAME).so.$(PNGMAJ)
+LIBSOREL=$(LIBSOMAJ).$(RELEASE)
+OLDSO=libpng.so
+# Utilities:
+CC=cc
+AR_RC=ar rc
+MKDIR_P=mkdir -p
+LN_SF=ln -f -s
+RANLIB=echo
+RM_F=/bin/rm -f
+SUN_CC_FLAGS=-fast -xtarget=ultra -xarch=v9
+SUN_LD_FLAGS=-fast -xtarget=ultra -xarch=v9
+# where make install puts libpng.a, libpng15.so and libpng15/png.h
+prefix=/a
+exec_prefix=$(prefix)
+# Where the zlib library and include files are located
+# Changing these to ../zlib poses a security risk.  If you want
+# to have zlib in an adjacent directory, specify the full path instead of "..".
+#ZLIBLIB=../zlib
+#ZLIBINC=../zlib
+ZLIBLIB=/usr/lib
+ZLIBINC=/usr/include
+WARNMORE=-Wwrite-strings -Wpointer-arith -Wshadow \
+        -Wmissing-declarations -Wtraditional -Wcast-align \
+        -Wstrict-prototypes -Wmissing-prototypes #-Wconversion
+CFLAGS=-I$(ZLIBINC) $(SUN_CC_FLAGS) \
+        # $(WARNMORE) -g -DPNG_DEBUG=5
+LDFLAGS=-L. -R. $(SUN_LD_FLAGS) -L$(ZLIBLIB) -R$(ZLIBLIB) -lpng15 -lz -lm
+INCPATH=$(prefix)/include
+LIBPATH=$(exec_prefix)/lib
+MANPATH=$(prefix)/man
+BINPATH=$(exec_prefix)/bin
+# override DESTDIR= on the make install command line to easily support
+# installing into a temporary location.  Example:
+#
+#    make install DESTDIR=/tmp/build/libpng
+#
+# If you're going to install into a temporary location
+# via DESTDIR, $(DESTDIR)$(prefix) must already exist before
+# you execute make install.
+DESTDIR=
+DB=$(DESTDIR)$(BINPATH)
+DI=$(DESTDIR)$(INCPATH)
+DL=$(DESTDIR)$(LIBPATH)
+DM=$(DESTDIR)$(MANPATH)
+OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
+        pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
+        pngwtran.o pngmem.o pngerror.o pngpread.o
+OBJSDLL = $(OBJS:.o=.pic.o)
+.SUFFIXES:      .c .o .pic.o
+.c.pic.o:
+        $(CC) -c $(CFLAGS) -KPIC -o $@ $*.c
+all: libpng.a $(LIBSO) pngtest libpng.pc libpng-config
+include scripts/pnglibconf.mak
+DELETE = $(RM_F)
+DFNFLAGS = $(DEFS) $(CPPFLAGS)
+libpng.a: $(OBJS)
+        $(AR_RC) $@ $(OBJS)
+        $(RANLIB) $@
+libpng.pc:
+        cat scripts/libpng.pc.in | sed -e s!@prefix@!$(prefix)! \
+        -e s!@exec_prefix@!$(exec_prefix)! \
+        -e s!@libdir@!$(LIBPATH)! \
+        -e s!@includedir@!$(INCPATH)! \
+        -e s!-lpng15!-lpng15\ -lz\ -lm! > libpng.pc
+libpng-config:
+        ( cat scripts/libpng-config-head.in; \
+        echo prefix=\"$(prefix)\"; \
+        echo libdir=\"$(LIBPATH)\"; \
+        echo I_opts=\"-I$(INCPATH)/$(LIBNAME)\"; \
+        echo L_opts=\"-L$(LIBPATH)\"; \
+        echo R_opts=\"-R$(LIBPATH)\"; \
+        echo ccopts=\"-xtarget=ultra -xarch=v9\"; \
+        echo ldopts=\"-xtarget=ultra -xarch=v9\"; \
+        echo libs=\"-lpng15 -lz -lm\"; \
+        cat scripts/libpng-config-body.in ) > libpng-config
+        chmod +x libpng-config
+$(LIBSO): $(LIBSOMAJ)
+        $(LN_SF) $(LIBSOMAJ) $(LIBSO)
+$(LIBSOMAJ): $(OBJSDLL)
+        @case "`type ld`" in *ucb*) \
+        echo; \
+        echo '## WARNING:'; \
+        echo '## The commands "CC" and "LD" must NOT refer to /usr/ucb/cc'; \
+        echo '## and /usr/ucb/ld.  If they do, you need to adjust your PATH'; \
+        echo '## environment variable to put /usr/ccs/bin ahead of /usr/ucb.'; \
+        echo '## The environment variable LD_LIBRARY_PATH should not be set'; \
+        echo '## at all.  If it is, things are likely to break because of'; \
+        echo '## the libucb dependency that is created.'; \
+        echo; \
+        ;; \
+        esac
+        $(LD) -G -L$(ZLIBLIB) -R$(ZLIBLIB) -h $(LIBSOMAJ) \
+         -o $(LIBSOMAJ) $(OBJSDLL)
+pngtest: pngtest.o $(LIBSO)
+        $(CC) -o pngtest $(CFLAGS) pngtest.o $(LDFLAGS)
+test: pngtest
+        ./pngtest
+install-headers: png.h pngconf.h
+        -@if [ ! -d $(DI) ]; then $(MKDIR_P) $(DI); fi
+        -@if [ ! -d $(DI)/$(LIBNAME) ]; then $(MKDIR_P) $(DI)/$(LIBNAME); fi
+        cp png.h pngconf.h pnglibconf.h $(DI)/$(LIBNAME)
+        chmod 644 $(DI)/$(LIBNAME)/png.h $(DI)/$(LIBNAME)/pngconf.h $(DI)/$(LIBNAME)/pnglibconf.h
+        -@$(RM_F) $(DI)/png.h $(DI)/pngconf.h $(DI)/pnglibconf.h
+        -@$(RM_F) $(DI)/libpng
+        (cd $(DI); $(LN_SF) $(LIBNAME) libpng; $(LN_SF) $(LIBNAME)/* .)
+install-static: install-headers libpng.a
+        -@if [ ! -d $(DL) ]; then $(MKDIR_P) $(DL); fi
+        cp libpng.a $(DL)/$(LIBNAME).a
+        chmod 644 $(DL)/$(LIBNAME).a
+        -@$(RM_F) $(DL)/libpng.a
+        (cd $(DL); $(LN_SF) $(LIBNAME).a libpng.a)
+install-shared: install-headers $(LIBSOMAJ) libpng.pc
+        -@if [ ! -d $(DL) ]; then $(MKDIR_P) $(DL); fi
+        -@$(RM_F) $(DL)/$(LIBSO)
+        -@$(RM_F) $(DL)/$(LIBSOREL)
+        -@$(RM_F) $(DL)/$(OLDSO)
+        cp $(LIBSOMAJ) $(DL)/$(LIBSOREL)
+        chmod 755 $(DL)/$(LIBSOREL)
+        (cd $(DL); \
+        $(LN_SF) $(LIBSOREL) $(LIBSO); \
+        $(LN_SF) $(LIBSO) $(OLDSO))
+        -@if [ ! -d $(DL)/pkgconfig ]; then $(MKDIR_P) $(DL)/pkgconfig; fi
+        -@$(RM_F) $(DL)/pkgconfig/$(LIBNAME).pc
+        -@$(RM_F) $(DL)/pkgconfig/libpng.pc
+        cp libpng.pc $(DL)/pkgconfig/$(LIBNAME).pc
+        chmod 644 $(DL)/pkgconfig/$(LIBNAME).pc
+        (cd $(DL)/pkgconfig; $(LN_SF) $(LIBNAME).pc libpng.pc)
+install-man: libpng.3 libpngpf.3 png.5
+        -@if [ ! -d $(DM) ]; then $(MKDIR_P) $(DM); fi
+        -@if [ ! -d $(DM)/man3 ]; then $(MKDIR_P) $(DM)/man3; fi
+        -@$(RM_F) $(DM)/man3/libpng.3
+        -@$(RM_F) $(DM)/man3/libpngpf.3
+        cp libpng.3 $(DM)/man3
+        cp libpngpf.3 $(DM)/man3
+        -@if [ ! -d $(DM)/man5 ]; then $(MKDIR_P) $(DM)/man5; fi
+        -@$(RM_F) $(DM)/man5/png.5
+        cp png.5 $(DM)/man5
+install-config: libpng-config
+        -@if [ ! -d $(DB) ]; then $(MKDIR_P) $(DB); fi
+        -@$(RM_F) $(DB)/libpng-config
+        -@$(RM_F) $(DB)/$(LIBNAME)-config
+        cp libpng-config $(DB)/$(LIBNAME)-config
+        chmod 755 $(DB)/$(LIBNAME)-config
+        (cd $(DB); $(LN_SF) $(LIBNAME)-config libpng-config)
+install: install-static install-shared install-man install-config
+# If you installed in $(DESTDIR), test-installed won't work until you
+# move the library to its final location.  Use test-dd to test it
+# before then.
+test-dd:
+        echo
+        echo Testing installed dynamic shared library in $(DL).
+        $(CC) $(SUN_CC_FLAGS) -I$(DI) -I$(ZLIBINC) \
+           `$(BINPATH)/$(LIBNAME)-config --cflags` pngtest.c \
+           -o pngtestd -L$(DL) -R$(DL) `$(BINPATH)/$(LIBNAME)-config --ldflags` \
+           $(SUN_LD_FLAGS) -L$(ZLIBLIB) -R$(ZLIBLIB)
+        ./pngtestd pngtest.png
+test-installed:
+        echo
+        echo Testing installed dynamic shared library.
+        $(CC) $(SUN_CC_FLAGS) -I$(ZLIBINC) \
+           `$(BINPATH)/$(LIBNAME)-config --cflags` pngtest.c \
+           -o pngtesti `$(BINPATH)/$(LIBNAME)-config --ldflags` \
+           $(SUN_LD_FLAGS) -L$(ZLIBLIB) -R$(ZLIBLIB)
+        ./pngtesti pngtest.png
+clean:
+        $(RM_F) *.o libpng.a pngtest pngtesti pngout.png \
+        libpng-config $(LIBSO) $(LIBSOMAJ)* \
+        libpng.pc
+DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
+writelock:
+        chmod a-w *.[ch35] $(DOCS) scripts/*
+# DO NOT DELETE THIS LINE -- make depend depends on it.
+png.o png.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngerror.o pngerror.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrio.o pngrio.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwio.o pngwio.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngmem.o pngmem.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngset.o pngset.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngget.o pngget.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngread.o pngread.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrtran.o pngrtran.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrutil.o pngrutil.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtrans.o pngtrans.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwrite.o pngwrite.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwtran.o pngwtran.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwutil.o pngwutil.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngpread.o pngpread.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtest.o: png.h pngconf.h pnglibconf.h
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.acorn b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.acorn
new file mode 100644
index 0000000..4181913
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.acorn
@@ -0,0 +1,57 @@
+# Project:   libpng
+# Toolflags:
+CCflags = -c -depend !Depend -IC:,Zlib: -g -throwback  -DRISCOS  -fnah
+C++flags = -c -depend !Depend -IC: -throwback
+Linkflags = -aif -c++ -o $@
+ObjAsmflags = -throwback -NoCache -depend !Depend
+CMHGflags =
+LibFileflags = -c -l -o $@
+Squeezeflags = -o $@
+# Final targets:
+@.libpng-lib:   @.o.png @.o.pngerror @.o.pngrio @.o.pngwio @.o.pngmem \
+        @.o.pngpread @.o.pngset @.o.pngget @.o.pngread @.o.pngrtran \
+        @.o.pngrutil @.o.pngtrans @.o.pngwrite @.o.pngwtran @.o.pngwutil
+        LibFile $(LibFileflags) @.o.png @.o.pngerror @.o.pngrio @.o.pngrtran \
+        @.o.pngmem @.o.pngpread @.o.pngset @.o.pngget @.o.pngread @.o.pngwio \
+        @.o.pngrutil @.o.pngtrans  @.o.pngwrite @.o.pngwtran @.o.pngwutil
+@.mm-libpng-lib:   @.mm.png @.mm.pngerror @.mm.pngrio @.mm.pngwio @.mm.pngmem \
+        @.mm.pngpread @.mm.pngset @.mm.pngget @.mm.pngread @.mm.pngrtran \
+        @.mm.pngrutil @.mm.pngtrans @.mm.pngwrite @.mm.pngwtran @.mm.pngwutil
+        LibFile $(LibFileflags) @.mm.png @.mm.pngerror @.mm.pngrio \
+        @.mm.pngwio @.mm.pngmem @.mm.pngpread @.mm.pngset @.mm.pngget \
+        @.mm.pngread @.mm.pngrtran @.mm.pngrutil @.mm.pngtrans @.mm.pngwrite \
+        @.mm.pngwtran @.mm.pngwutil
+# User-editable dependencies:
+# (C) Copyright 1997 Tom Tanner
+Test: @.pngtest
+        <Prefix$Dir>.pngtest
+        @remove <Prefix$Dir>.pngtest
+#It would be nice if you could stop "make" listing from here on!
+@.pngtest:   @.o.pngtest @.libpng-lib C:o.Stubs Zlib:zlib_lib
+        Link $(Linkflags) @.o.pngtest @.libpng-lib C:o.Stubs Zlib:zlib_lib
+.SUFFIXES: .o .mm .c
+.c.mm:
+        MemCheck.CC cc $(ccflags) -o $@ LibPng:$<
+.c.o:
+        cc $(ccflags) -o $@ $<
+# See scripts.mak.libpngconf for how to generate this:
+@.h.libpngconf: @.scripts.h.libpngconf
+        copy @.scripts.h.libpngconf $@
+# Static dependencies:
+@.o.png @.o.pngerror @.o.pngrio @.o.pngwio @.o.pngmem \
+@.o.pngpread @.o.pngset @.o.pngget @.o.pngread @.o.pngrtran \
+@.o.pngrutil @.o.pngtrans @.o.pngwrite @.o.pngwtran @.o.pngwutil \
+@.o.pngtest: @.h.libpngconf
+# Dynamic dependencies:
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.aix b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.aix
new file mode 100644
index 0000000..1b1e18f
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.aix
@@ -0,0 +1,121 @@
+# makefile for libpng using gcc (generic, static library)
+# Copyright (C) 2002, 2006-2009 Glenn Randers-Pehrson
+# Copyright (C) 2000 Cosmin Truta
+# Copyright (C) 2000 Marc O. Gloor (AIX support added, from makefile.gcc)
+# Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
+#
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+# Location of the zlib library and include files
+ZLIBINC = ../zlib
+ZLIBLIB = ../zlib
+# Compiler, linker, lib and other tools
+CC = gcc
+LD = $(CC)
+AR_RC = ar rcs
+MKDIR_P = mkdir -p
+RANLIB = ranlib
+RM_F = rm -f
+LN_SF = ln -f -s
+LIBNAME=libpng15
+PNGMAJ = 15
+prefix=/usr/local
+INCPATH=$(prefix)/include
+LIBPATH=$(prefix)/lib
+# override DESTDIR= on the make install command line to easily support
+# installing into a temporary location.  Example:
+#
+#    make install DESTDIR=/tmp/build/libpng
+#
+# If you're going to install into a temporary location
+# via DESTDIR, $(DESTDIR)$(prefix) must already exist before
+# you execute make install.
+DESTDIR=
+DI=$(DESTDIR)$(INCPATH)
+DL=$(DESTDIR)$(LIBPATH)
+CDEBUG = -g -DPNG_DEBUG=5
+LDDEBUG =
+CRELEASE = -O2
+LDRELEASE = -s
+WARNMORE=-W -Wall
+CFLAGS = -I$(ZLIBINC) $(WARNMORE) $(CRELEASE)
+LDFLAGS = -L. -L$(ZLIBLIB) -lpng15 -lz -lm $(LDRELEASE)
+# File extensions
+O=.o
+A=.a
+E=
+# Variables
+OBJS =  png$(O) pngerror$(O) pngget$(O) pngmem$(O) pngpread$(O) \
+        pngread$(O) pngrio$(O) pngrtran$(O) pngrutil$(O) pngset$(O) \
+        pngtrans$(O) pngwio$(O) pngwrite$(O) pngwtran$(O) pngwutil$(O)
+# Targets
+all: $(LIBNAME)$(A) pngtest$(E)
+include scripts/pnglibconf.mak
+REMOVE = $(RM_F)
+DFNFLAGS = $(DEFS) $(CPPFLAGS)
+$(LIBNAME)$(A): $(OBJS)
+        $(AR_RC) $@ $(OBJS)
+        $(RANLIB) $@
+test: pngtest$(E)
+        ./pngtest$(E)
+pngtest$(E): pngtest$(O) $(LIBNAME)$(A)
+        $(LD) -o $@ pngtest$(O) $(LDFLAGS)
+install: $(LIBNAME)$(A)
+        -@if [ ! -d $(DI)  ]; then $(MKDIR_P) $(DI); fi
+        -@if [ ! -d $(DI)/$(LIBNAME)  ]; then $(MKDIR_P) $(DI)/$(LIBNAME); fi
+        -@if [ ! -d $(DL) ]; then $(MKDIR_P) $(DL); fi
+        -@$(RM_F) $(DI)/$(LIBNAME)/png.h
+        -@$(RM_F) $(DI)/$(LIBNAME)/pngconf.h
+        -@$(RM_F) $(DI)/$(LIBNAME)/pnglibconf.h
+        -@$(RM_F) $(DI)/png.h
+        -@$(RM_F) $(DI)/pngconf.h
+        -@$(RM_F) $(DI)/pnglibconf.h
+        cp png.h pngconf.h pnglibconf.h $(DI)/$(LIBNAME)
+        chmod 644 $(DI)/$(LIBNAME)/png.h \
+        $(DI)/$(LIBNAME)/pngconf.h \
+        $(DI)/$(LIBNAME)/pnglibconf.h
+        -@$(RM_F) -r $(DI)/libpng
+        (cd $(DI); $(LN_SF) $(LIBNAME) libpng; $(LN_SF) $(LIBNAME)/* .)
+        -@$(RM_F) $(DL)/$(LIBNAME)$(A)
+        -@$(RM_F) $(DL)/libpng$(A)
+        cp $(LIBNAME)$(A) $(DL)/$(LIBNAME)$(A)
+        chmod 644 $(DL)/$(LIBNAME)$(A)
+        (cd $(DL); $(LN_SF) $(LIBNAME)$(A) libpng$(A))
+        (cd $(DI); $(LN_SF) libpng/* .;)
+clean:
+        $(RM_F) *.o $(LIBNAME)$(A) pngtest pngout.png pnglibconf.h
+png$(O):      png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngerror$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngget$(O):   png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngmem$(O):   png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngpread$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngread$(O):  png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrio$(O):   png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrtran$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrutil$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngset$(O):   png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtrans$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwio$(O):   png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwrite$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwtran$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwutil$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtest$(O):  png.h pngconf.h pnglibconf.h
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.amiga b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.amiga
new file mode 100644
index 0000000..f23f254
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.amiga
@@ -0,0 +1,56 @@
+# Commodore Amiga Makefile
+# makefile for libpng and SAS C V6.5x compiler
+# Copyright (C) 1995-2000 Wolf Faust
+#
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+#
+# Location/path of zlib include files
+ZLIB=/zlib
+#compiler
+CC=sc
+#compiler flags
+# WARNING: a bug in V6.51 causes bad code with OPTGO
+#          So use V6.55 or set NOOPTGO!!!!!!!!!
+CFLAGS= NOSTKCHK PARMS=REG OPTIMIZE OPTGO OPTPEEP OPTINLOCAL OPTINL\
+        OPTLOOP OPTRDEP=4 OPTDEP=4 OPTCOMP=4 INCLUDEDIR=$(ZLIB) \
+        DEFINE=PNG_INTERNAL
+#linker flags
+LDFLAGS= SD ND BATCH
+#link libs
+LDLIBS= libpng.lib libgz.lib LIB:scm.lib LIB:sc.lib Lib:amiga.lib
+# linker
+LN= slink
+# file deletion command
+RM= delete quiet
+# file copy command?
+CP= copy
+# library (.lib) file creation command
+AR= oml
+# make directory command
+MKDIR= makedir
+OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
+        pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
+        pngwtran.o pngmem.o pngerror.o pngpread.o
+all: libpng.lib pngtest
+libpng.lib: $(OBJS)
+-$(RM) libpng.lib
+$(AR) libpng.lib r $(OBJS)
+$(OBJS): pngpriv.h png.h pngconf.h pnglibconf.h pnginfo.h pngstruct.h pngdebug.h
+pnglibconf.h: scripts/pnglibconf.h.prebuilt
+$(CP) scripts/pnglibconf.h.prebuilt pnglibconf.h
+pngtest: pngtest.o libpng.lib
+$(LN) <WITH <
+$(LDFLAGS)
+TO pngtest
+FROM LIB:c.o pngtest.o
+LIB $(LDLIBS)
+<
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.atari b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.atari
new file mode 100644
index 0000000..aa28ce5
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.atari
@@ -0,0 +1,63 @@
+# makefile for libpng
+# Copyright (C) 2002 Glenn Randers-Pehrson
+# Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
+#
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+#
+# Modified for LC56/ATARI assumes libz.lib is in same dir and uses default
+# rules for library management
+#
+CFLAGS=-I..\zlib -O
+LBR = png.lib
+LDFLAGS=-lpng -lz -lm
+# where make install puts libpng.a and png.h
+prefix=/usr/local
+INCPATH=$(prefix)/include
+LIBPATH=$(prefix)/lib
+# override DESTDIR= on the make install command line to easily support
+# installing into a temporary location.  Example:
+#
+#    make install DESTDIR=/tmp/build/libpng
+#
+# If you're going to install into a temporary location
+# via DESTDIR, $(DESTDIR)$(prefix) must already exist before
+# you execute make install.
+DESTDIR=
+OBJS = $(LBR)(png.o) $(LBR)(pngset.o) $(LBR)(pngget.o) $(LBR)(pngrutil.o)\
+        $(LBR)(pngtrans.o) $(LBR)(pngwutil.o)\
+        $(LBR)(pngread.o) $(LBR)(pngerror.o) $(LBR)(pngwrite.o)\
+        $(LBR)(pngrtran.o) $(LBR)(pngwtran.o)\
+        $(LBR)(pngmem.o) $(LBR)(pngrio.o) $(LBR)(pngwio.o) $(LBR)(pngpread.o)
+all: $(LBR) pngtest.ttp
+$(LBR): $(OBJS)
+$(OBJS): pngpriv.h png.h pngconf.h pnglibconf.h pnginfo.h pngstruct.h pngdebug.h
+pnglibconf.h: scripts/pnglibconf.h.prebuilt
+        cp scripts/pnglibconf.h.prebuilt pnglibconf.h
+pngtest.ttp: pngtest.o $(LBR)
+        $(CC) $(CFLAGS) $(LDFLAGS) -o$@ pngtest.o
+install: libpng.a
+        -@mkdir $(DESTDIR)$(INCPATH)
+        -@mkdir $(DESTDIR)$(INCPATH)/libpng
+        -@mkdir $(DESTDIR)$(LIBPATH)
+        -@rm -f $(DESTDIR)$(INCPATH)/png.h
+        -@rm -f $(DESTDIR)$(INCPATH)/pngconf.h
+        -@rm -f $(DESTDIR)$(INCPATH)/pnglibconf.h
+        cp png.h $(DESTDIR)$(INCPATH)/libpng
+        cp pngconf.h $(DESTDIR)$(INCPATH)/libpng
+        cp pnglibconf.h $(DESTDIR)$(INCPATH)/libpng
+        chmod 644 $(DESTDIR)$(INCPATH)/libpng/png.h
+        chmod 644 $(DESTDIR)$(INCPATH)/libpng/pngconf.h
+        chmod 644 $(DESTDIR)$(INCPATH)/libpng/pnglibconf.h
+        (cd $(DESTDIR)$(INCPATH); ln -f -s $(LIBNAME) libpng; \
+        ln -f -s $(LIBNAME)/* .)
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.bc32 b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.bc32
new file mode 100644
index 0000000..48311e9
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.bc32
@@ -0,0 +1,151 @@
+# Makefile for libpng
+# 32-bit Borland C++ (Note: All modules are compiled in C mode)
+# To build the library, do:
+#       "make -fmakefile.bc32"
+#
+# -------------------- 32-bit Borland C++ --------------------
+### Absolutely necessary for this makefile to work
+.AUTODEPEND
+## Where zlib.h, zconf.h and zlib.lib are
+ZLIB_DIR=..\zlib
+## Compiler, linker and lib stuff
+CC=bcc32
+LD=bcc32
+LIB=tlib
+# -3 = 386, -4 = 486, -5 = Pentium etc.
+!ifndef TARGET_CPU
+#TARGET_CPU=-6
+!endif
+# Use this if you don't want Borland's fancy exception handling
+# (Caution: doesn't work with CBuilderX)
+#NOEHLIB=noeh32.lib
+!ifdef DEBUG
+CDEBUG=-v
+LDEBUG=-v
+!else
+CDEBUG=
+LDEBUG=
+!endif
+# STACKOFLOW=1
+!ifdef STACKOFLOW
+CDEBUG=$(CDEBUG) -N
+LDEBUG=$(LDEBUG) -N
+!endif
+# -O2 optimize for speed
+# -d  merge duplicate strings
+# -k- turn off standard stack frame
+# -w  display all warnings
+CFLAGS=-I$(ZLIB_DIR) -O2 -d -k- -w $(TARGET_CPU) $(CDEBUG)
+# -M  generate map file
+LDFLAGS=-L$(ZLIB_DIR) -M $(LDEBUG)
+## Variables
+OBJS = \
+        png.obj \
+        pngerror.obj \
+        pngget.obj \
+        pngmem.obj \
+        pngpread.obj \
+        pngread.obj \
+        pngrio.obj \
+        pngrtran.obj \
+        pngrutil.obj \
+        pngset.obj \
+        pngtrans.obj \
+        pngwio.obj \
+        pngwrite.obj \
+        pngwtran.obj \
+        pngwutil.obj
+LIBOBJS = \
+        +png.obj \
+        +pngerror.obj \
+        +pngget.obj \
+        +pngmem.obj \
+        +pngpread.obj \
+        +pngread.obj \
+        +pngrio.obj \
+        +pngrtran.obj \
+        +pngrutil.obj \
+        +pngset.obj \
+        +pngtrans.obj \
+        +pngwio.obj \
+        +pngwrite.obj \
+        +pngwtran.obj \
+        +pngwutil.obj
+LIBNAME=libpng.lib
+## Implicit rules
+# Braces let make "batch" calls to the compiler,
+# 2 calls instead of 12; space is important.
+.c.obj:
+        $(CC) $(CFLAGS) -c {$*.c }
+.c.exe:
+        $(CC) $(CFLAGS) $(LDFLAGS) $*.c $(LIBNAME) zlib.lib $(NOEHLIB)
+.obj.exe:
+        $(LD) $(LDFLAGS) $*.obj $(LIBNAME) zlib.lib $(NOEHLIB)
+## Major targets
+all: libpng pngtest
+libpng: $(LIBNAME)
+pngtest: pngtest.exe
+test: pngtest.exe
+        pngtest
+## Minor Targets
+# see scripts\pnglibconf.mak for how to make this file
+# with different options
+pnglibconf.h: scripts\pnglibconf.h.prebuilt
+        copy scripts\pnglibconf.h.prebuilt $@
+png.obj: png.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngerror.obj: pngerror.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngget.obj: pngget.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngmem.obj: pngmem.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngpread.obj: pngpread.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngread.obj: pngread.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrio.obj: pngrio.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrtran.obj: pngrtran.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrutil.obj: pngrutil.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngset.obj: pngset.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtrans.obj: pngtrans.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwio.obj: pngwio.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwrite.obj: pngwrite.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwtran.obj: pngwtran.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwutil.obj: pngwutil.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtest.obj: pngtest.c png.h pngconf.h pnglibconf.h
+$(LIBNAME): $(OBJS)
+        -del $(LIBNAME)
+        $(LIB) $(LIBNAME) @&&|
+$(LIBOBJS), libpng
+|
+# Cleanup
+clean:
+        -del pnglibconf.h
+        -del *.obj
+        -del $(LIBNAME)
+        -del pngtest.exe
+        -del *.lst
+        -del *.map
+        -del *.tds
+        -del pngout.png
+# End of makefile for libpng
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.beos b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.beos
new file mode 100644
index 0000000..ff1743c
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.beos
@@ -0,0 +1,215 @@
+# makefile for libpng on BeOS x86 ELF with gcc
+# modified from makefile.linux by Sander Stoks
+# Copyright (C) 2002, 2006, 2008, 2010-2011 Glenn Randers-Pehrson
+# Copyright (C) 1999 Greg Roelofs
+# Copyright (C) 1996, 1997 Andreas Dilger
+#
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+# Library name:
+LIBNAME=libpng15
+PNGMAJ = 15
+# Shared library names:
+LIBSO=$(LIBNAME).so
+LIBSOMAJ=$(LIBNAME).so.$(PNGMAJ)
+LIBSOREL=$(LIBSOMAJ).$(RELEASE)
+OLDSO=libpng.so
+# Utilities:
+CC=gcc
+AR_RC=ar rc
+MKDIR_P=mkdir -p
+LN_SF=ln -sf
+RANLIB=ranlib
+RM_F=/bin/rm -f
+# Where the zlib library and include files are located
+ZLIBLIB=/usr/local/lib
+ZLIBINC=/usr/local/include
+ALIGN=
+# For i386:
+# ALIGN=-malign-loops=2 -malign-functions=2
+WARNMORE=-Wwrite-strings -Wpointer-arith -Wshadow \
+        -Wmissing-declarations -Wtraditional -Wcast-align \
+        -Wstrict-prototypes -Wmissing-prototypes #-Wconversion
+# On BeOS, -O1 is actually better than -O3.  This is a known bug but it's
+# still here in R4.5
+CFLAGS=-I$(ZLIBINC) -W -Wall -O1 -funroll-loops \
+        $(ALIGN) # $(WARNMORE) -g -DPNG_DEBUG=5
+# LDFLAGS=-L. -Wl,-rpath,. -L$(ZLIBLIB) -Wl,-rpath,$(ZLIBLIB) -lpng -lz
+LDFLAGS=-L. -Wl,-soname=$(LIBSOMAJ) -L$(ZLIBLIB) -lz
+# where make install puts libpng.a, libpng15.so*, and png.h
+prefix=/usr/local
+exec_prefix=$(prefix)
+INCPATH=$(prefix)/include
+LIBPATH=$(exec_prefix)/lib
+MANPATH=$(prefix)/man
+BINPATH=$(exec_prefix)/bin
+# override DESTDIR= on the make install command line to easily support
+# installing into a temporary location.  Example:
+#
+#    make install DESTDIR=/tmp/build/libpng
+#
+# If you're going to install into a temporary location
+# via DESTDIR, $(DESTDIR)$(prefix) must already exist before
+# you execute make install.
+DESTDIR=
+DB=$(DESTDIR)$(BINPATH)
+DI=$(DESTDIR)$(INCPATH)
+DL=$(DESTDIR)$(LIBPATH)
+DM=$(DESTDIR)$(MANPATH)
+OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
+        pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
+        pngwtran.o pngmem.o pngerror.o pngpread.o
+OBJSDLL = $(OBJS)
+.SUFFIXES:      .c .o
+all: libpng.a $(LIBSO) pngtest libpng.pc libpng-config
+# try include scripts/pnglibconf.mak for more options
+pnglibconf.h: scripts/pnglibconf.h.prebuilt
+        cp scripts/pnglibconf.h.prebuilt $@
+libpng.a: $(OBJS)
+        $(AR_RC) $@ $(OBJS)
+        $(RANLIB) $@
+libpng.pc:
+        cat scripts/libpng.pc.in | sed -e s!@prefix@!$(prefix)! \
+        -e s!@exec_prefix@!$(exec_prefix)! \
+        -e s!@libdir@!$(LIBPATH)! \
+        -e s!@includedir@!$(INCPATH)! \
+        -e s!-lpng15!-lpng15\ -lz\ -lm! > libpng.pc
+libpng-config:
+        ( cat scripts/libpng-config-head.in; \
+        echo prefix=\"$(prefix)\"; \
+        echo I_opts=\"-I$(INCPATH)/$(LIBNAME)\"; \
+        echo libs=\"-lpng15 -lz \"; \
+        cat scripts/libpng-config-body.in ) > libpng-config
+        chmod +x libpng-config
+$(LIBSO): $(LIBSOMAJ)
+        $(LN_SF) $(LIBSOMAJ) $(LIBSO)
+        cp $(LIBSO)* /boot/home/config/lib
+$(LIBSOMAJ): $(OBJSDLL)
+        $(CC) -nostart -Wl,-soname,$(LIBSOMAJ) -o \
+        $(LIBSOMAJ) $(OBJSDLL) $(LDFLAGS)
+pngtest: pngtest.o $(LIBSO)
+        $(CC) -L$(ZLIBLIB) -L. -lz -lpng15 -o pngtest pngtest.o
+test: pngtest
+        ./pngtest
+install-headers: png.h pngconf.h pnglibconf.h
+        -@if [ ! -d $(DI) ]; then $(MKDIR_P) $(DI); fi
+        -@if [ ! -d $(DI)/$(LIBNAME) ]; then $(MKDIR_P) $(DI)/$(LIBNAME); fi
+        cp png.h pngconf.h pnglibconf.h $(DI)/$(LIBNAME)
+        chmod 644 $(DI)/$(LIBNAME)/png.h $(DI)/$(LIBNAME)/pngconf.h $(DI)/$(LIBNAME)/pnglibconf.h
+        -@$(RM_F) $(DI)/png.h $(DI)/pngconf.h $(DI)/pnglibconf.h
+        -@$(RM_F) $(DI)/libpng
+        (cd $(DI); $(LN_SF) $(LIBNAME) libpng; $(LN_SF) $(LIBNAME)/* .)
+install-static: install-headers libpng.a
+        -@if [ ! -d $(DL) ]; then $(MKDIR_P) $(DL); fi
+        cp libpng.a $(DL)/$(LIBNAME).a
+        chmod 644 $(DL)/$(LIBNAME).a
+        -@$(RM_F) $(DL)/libpng.a
+        (cd $(DL); $(LN_SF) $(LIBNAME).a libpng.a)
+install-shared: install-headers $(LIBSOMAJ) libpng.pc
+        -@if [ ! -d $(DL) ]; then $(MKDIR_P) $(DL); fi
+        -@$(RM_F) $(DL)/$(LIBSO)
+        -@$(RM_F) $(DL)/$(LIBSOREL)
+        -@$(RM_F) $(DL)/$(OLDSO)
+        cp $(LIBSOMAJ) $(DL)/$(LIBSOREL)
+        chmod 755 $(DL)/$(LIBSOREL)
+        (cd $(DL); \
+        $(LN_SF) $(LIBSOREL) $(LIBSO); \
+        $(LN_SF) $(LIBSO) $(OLDSO))
+        -@if [ ! -d $(DL)/pkgconfig ]; then $(MKDIR_P) $(DL)/pkgconfig; fi
+        -@$(RM_F) $(DL)/pkgconfig/$(LIBNAME).pc
+        -@$(RM_F) $(DL)/pkgconfig/libpng.pc
+        cp libpng.pc $(DL)/pkgconfig/$(LIBNAME).pc
+        chmod 644 $(DL)/pkgconfig/$(LIBNAME).pc
+        (cd $(DL)/pkgconfig; $(LN_SF) $(LIBNAME).pc libpng.pc)
+install-man: libpng.3 libpngpf.3 png.5
+        -@if [ ! -d $(DM) ]; then $(MKDIR_P) $(DM); fi
+        -@if [ ! -d $(DM)/man3 ]; then $(MKDIR_P) $(DM)/man3; fi
+        -@$(RM_F) $(DM)/man3/libpng.3
+        -@$(RM_F) $(DM)/man3/libpngpf.3
+        cp libpng.3 $(DM)/man3
+        cp libpngpf.3 $(DM)/man3
+        -@if [ ! -d $(DM)/man5 ]; then $(MKDIR_P) $(DM)/man5; fi
+        -@$(RM_F) $(DM)/man5/png.5
+        cp png.5 $(DM)/man5
+install-config: libpng-config
+        -@if [ ! -d $(DB) ]; then $(MKDIR_P) $(DB); fi
+        -@$(RM_F) $(DB)/libpng-config
+        -@$(RM_F) $(DB)/$(LIBNAME)-config
+        cp libpng-config $(DB)/$(LIBNAME)-config
+        chmod 755 $(DB)/$(LIBNAME)-config
+        (cd $(DB); $(LN_SF) $(LIBNAME)-config libpng-config)
+install: install-static install-shared install-man install-config
+# If you installed in $(DESTDIR), test-installed won't work until you
+# move the library to its final location.  Use test-dd to test it
+# before then.
+test-dd:
+        echo
+        echo Testing installed dynamic shared library in $(DL).
+        $(CC) -I$(DI) $(CFLAGS) \
+           `$(BINPATH)/$(LIBNAME)-config --cflags` pngtest.c \
+           -L$(DL) -L$(ZLIBLIB) -Wl,-rpath $(ZLIBLIB):$(DL) \
+           -o pngtestd `$(BINPATH)/$(LIBNAME)-config --ldflags`
+        ./pngtestd pngtest.png
+test-installed:
+        $(CC) $(CFLAGS) \
+           `$(BINPATH)/$(LIBNAME)-config --cflags` pngtest.c \
+           -L$(ZLIBLIB) -Wl,-rpath,$(ZLIBLIB) \
+           -o pngtesti `$(BINPATH)/$(LIBNAME)-config --ldflags`
+        ./pngtesti pngtest.png
+clean:
+        $(RM_F) *.o libpng.a pngtest pngout.png libpng-config \
+        $(LIBSO) $(LIBSOMAJ)* pngtesti \
+        pnglibconf.h libpng.pc
+# DO NOT DELETE THIS LINE -- make depend depends on it.
+png.o png.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngerror.o pngerror.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrio.o pngrio.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwio.o pngwio.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngmem.o pngmem.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngset.o pngset.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngget.o pngget.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngread.o pngread.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrtran.o pngrtran.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrutil.o pngrutil.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtrans.o pngtrans.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwrite.o pngwrite.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwtran.o pngwtran.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwutil.o pngwutil.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngpread.o pngpread.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtest.o: png.h pngconf.h pnglibconf.h
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.bor b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.bor
new file mode 100644
index 0000000..8251503
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.bor
@@ -0,0 +1,161 @@
+# Makefile for libpng
+# 16-bit Borland C++ (Note: All modules are compiled in C mode)
+# To build the library, do:
+#       "make -fmakefile.bor -DMODEL=c"
+# or:   "make -fmakefile.bor -DMODEL=l"
+#
+# ------------ Borland C++ ------------
+### Absolutely necessary for this makefile to work
+.AUTODEPEND
+## Where zlib.h, zconf.h and zlib_MODEL.lib are
+ZLIB_DIR=..\zlib
+## Compiler, linker and lib stuff
+CC=bcc
+LD=bcc
+LIB=tlib
+!ifndef MODEL
+MODEL=l
+!endif
+MODEL_ARG=-m$(MODEL)
+#TARGET_CPU=3
+# 2 = 286, 3 = 386, etc.
+!ifndef TARGET_CPU
+TARGET_CPU=2
+!endif
+# Use this if you don't want Borland's fancy exception handling
+# (for Borland C++ 4.0 or later)
+#NOEHLIB=noeh$(MODEL).lib
+!ifdef DEBUG
+CDEBUG=-v
+LDEBUG=-v
+!else
+CDEBUG=
+LDEBUG=
+!endif
+# STACKOFLOW=1
+!ifdef STACKOFLOW
+CDEBUG=$(CDEBUG) -N
+LDEBUG=$(LDEBUG) -N
+!endif
+# -X- turn on dependency generation in the object file
+# -w  set all warnings on
+# -O2 optimize for speed
+# -Z  global optimization
+CFLAGS=-O2 -Z -X- -w -I$(ZLIB_DIR) -$(TARGET_CPU) $(MODEL_ARG) $(CDEBUG)
+# -M  generate map file
+LDFLAGS=-M -L$(ZLIB_DIR) $(MODEL_ARG) $(LDEBUG)
+## Variables
+OBJS = \
+        png.obj \
+        pngerror.obj \
+        pngget.obj \
+        pngmem.obj \
+        pngpread.obj \
+        pngread.obj \
+        pngrio.obj \
+        pngrtran.obj \
+        pngrutil.obj \
+        pngset.obj \
+        pngtrans.obj \
+        pngwio.obj \
+        pngwrite.obj \
+        pngwtran.obj \
+        pngwutil.obj
+LIBOBJS = \
+        +png.obj \
+        +pngerror.obj \
+        +pngget.obj \
+        +pngmem.obj \
+        +pngpread.obj \
+        +pngread.obj \
+        +pngrio.obj \
+        +pngrtran.obj \
+        +pngrutil.obj \
+        +pngset.obj \
+        +pngtrans.obj \
+        +pngwio.obj \
+        +pngwrite.obj \
+        +pngwtran.obj \
+        +pngwutil.obj
+LIBNAME=libpng$(MODEL).lib
+## Implicit rules
+# Braces let make "batch" calls to the compiler,
+# 2 calls instead of 12; space is important.
+.c.obj:
+        $(CC) $(CFLAGS) -c {$*.c }
+.c.exe:
+        $(CC) $(CFLAGS) $(LDFLAGS) $*.c $(LIBNAME) zlib_$(MODEL).lib $(NOEHLIB)
+## Major targets
+all: libpng pngtest
+# try !inlude scripts\pnglibconf.mak for more options
+pnglibconf.h: scripts\pnglibconf.h.prebuilt
+        copy scripts\pnglibconf.h.prebuilt $@
+libpng: $(LIBNAME)
+pngtest: pngtest$(MODEL).exe
+test: pngtest$(MODEL).exe
+        pngtest$(MODEL)
+## Minor Targets
+png.obj: png.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngerror.obj: pngerror.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngget.obj: pngget.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngmem.obj: pngmem.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngpread.obj: pngpread.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngread.obj: pngread.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrio.obj: pngrio.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrtran.obj: pngrtran.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrutil.obj: pngrutil.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngset.obj: pngset.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtrans.obj: pngtrans.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwio.obj: pngwio.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwrite.obj: pngwrite.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwtran.obj: pngwtran.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwutil.obj: pngwutil.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+$(LIBNAME): $(OBJS)
+        -del $(LIBNAME)
+        $(LIB) $(LIBNAME) @&&|
+$(LIBOBJS), libpng$(MODEL)
+|
+pngtest$(MODEL).obj: pngtest.c png.h pngconf.h pnglibconf.h
+        $(CC) $(CFLAGS) -opngtest$(MODEL) -c pngtest.c
+pngtest$(MODEL).exe: pngtest$(MODEL).obj
+        $(LD) $(LDFLAGS) pngtest$(MODEL).obj $(LIBNAME) zlib_$(MODEL).lib $(NOEHLIB)
+# Clean up anything else you want
+clean:
+        -del pnglibconf.h
+        -del *.obj
+        -del *.exe
+        -del *.lib
+        -del *.lst
+        -del *.map
+# End of makefile for libpng
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.cegcc b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.cegcc
new file mode 100644
index 0000000..6d4f6ef
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.cegcc
@@ -0,0 +1,116 @@
+# Makefile for creating Windows CE release archives, with the
+# mingw32ce compiler.
+# Last updated: 22-Jul-2008
+# Copyright (C) 2008 Vincent Torri
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+# To get some help, type
+#
+# make help
+#
+# To create the archives
+#
+# make
+#
+# To remove everything, type:
+#
+# make clean
+VERMAJ = 1
+VERMIN = 5
+VERMIC = 9
+VER = $(VERMAJ).$(VERMIN).$(VERMIC)
+NAME = libpng
+PACKAGE = $(NAME)-$(VER)
+BIN = libpng15-0.dll
+LIB = libpng15.a libpng15.dll.a libpng.a libpng.dll.a
+INCLUDE = png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+PC = libpng15.pc libpng.pc
+MANIFESTVERBIN = "Libpng-$(VER): Binary files"
+MANIFESTVERDEV = "Libpng-$(VER): Developer files"
+MANIFESTVERDESC = "Libpng: the official PNG reference library"
+all: $(NAME)
+$(NAME): remove-old copy-src compilation copy manifest archive
+        @echo " * Removal of the directories"
+        @rm -rf $(PACKAGE)/ $(PACKAGE)-bin/ $(PACKAGE)-dev/
+remove-old:
+        @echo " * Removal of the old files"
+        @rm -rf $(PACKAGE)-bin*
+        @rm -rf $(PACKAGE)-dev*
+copy-src:
+        @echo " * Copy of source files"
+        @cp -R ../src/$(PACKAGE) .
+        @echo " * Creation of directories and files"
+        @mkdir -p $(PACKAGE)-bin/bin
+        @mkdir -p $(PACKAGE)-bin/manifest
+        @mkdir -p $(PACKAGE)-dev/lib/pkgconfig
+        @mkdir -p $(PACKAGE)-dev/include/$(NAME)$(VERMAJ)$(VERMIN)
+        @mkdir -p $(PACKAGE)-dev/manifest
+        @touch $(PACKAGE)-bin/manifest/$(PACKAGE)-bin.mft
+        @touch $(PACKAGE)-bin/manifest/$(PACKAGE)-bin.ver
+        @touch $(PACKAGE)-dev/manifest/$(PACKAGE)-dev.mft
+        @touch $(PACKAGE)-dev/manifest/$(PACKAGE)-dev.ver
+compilation:
+        @echo " * Compilation of $(PACKAGE)"
+        cd $(PACKAGE) && CPPFLAGS="$(CPPFLAGS) -DPNG_CONSOLE_IO_SUPPORTED -D_WIN32_WCE=0x0420" \
+                CFLAGS="$(CFLAGS) -mms-bitfields -O3 -pipe -fomit-frame-pointer" \
+                LDFLAGS="$(LDFLAGS) -Wl,--enable-auto-import -Wl,-s" \
+                ./configure --prefix=/opt/wince --host=arm-mingw32ce && make
+copy:
+        @echo " * Copy of binary and development files"
+        @for i in $(BIN); do \
+          cp $(PACKAGE)/.libs/$$i $(PACKAGE)-bin/bin; \
+        done
+        @for i in $(LIB); do \
+          cp $(PACKAGE)/.libs/$$i $(PACKAGE)-dev/lib; \
+        done
+        @for i in $(INCLUDE); do \
+          cp $(PACKAGE)/$$i $(PACKAGE)-dev/include/$(NAME)$(VERMAJ)$(VERMIN); \
+        done
+        @for i in $(PC); do \
+          cp $(PACKAGE)/$$i $(PACKAGE)-dev/lib/pkgconfig; \
+        done
+manifest:
+        @echo " * Creation of the manifest"
+        @cd $(PACKAGE)-bin && find * >> manifest/$(PACKAGE)-bin.mft
+        @cd $(PACKAGE)-bin && \
+          echo $(MANIFESTVERBIN) >> manifest/$(PACKAGE)-bin.ver && \
+          echo $(MANIFESTVERDESC) >> manifest/$(PACKAGE)-bin.ver
+        @cd $(PACKAGE)-dev && find * >> manifest/$(PACKAGE)-dev.mft
+        @cd $(PACKAGE)-dev && \
+          echo $(MANIFESTVERDEV) >> manifest/$(PACKAGE)-dev.ver && \
+          echo $(MANIFESTVERDESC) >> manifest/$(PACKAGE)-dev.ver
+archive:
+        @echo " * Creation of the archives"
+        @tar cf $(PACKAGE)-bin.tar $(PACKAGE)-bin
+        @bzip2 -9 $(PACKAGE)-bin.tar
+        @tar cf $(PACKAGE)-dev.tar $(PACKAGE)-dev
+        @bzip2 -9 $(PACKAGE)-dev.tar
+clean:
+        @echo " * Cleaning"
+        @rm -rf $(PACKAGE)*
+help:
+        @echo
+        @echo "To create the archives, type:"
+        @echo " make"
+        @echo
+        @echo "To remove everything, type:"
+        @echo " make clean"
+        @echo
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.darwin b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.darwin
new file mode 100644
index 0000000..bb62b09
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.darwin
@@ -0,0 +1,220 @@
+# makefile for libpng on Darwin / Mac OS X
+# Copyright (C) 2002, 2004, 2006, 2008, 2010-2011 Glenn Randers-Pehrson
+# Copyright (C) 2001 Christoph Pfisterer
+# derived from makefile.linux:
+#  Copyright (C) 1998, 1999 Greg Roelofs
+#  Copyright (C) 1996, 1997 Andreas Dilger
+#
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+# where "make install" puts libpng.a, libpng15.dylib, png.h, pngconf.h,
+# and pnglibconf.h
+prefix=/usr/local
+exec_prefix=$(prefix)
+# Where the zlib library and include files are located
+#ZLIBLIB=/usr/local/lib
+#ZLIBINC=/usr/local/include
+ZLIBLIB=../zlib
+ZLIBINC=../zlib
+# Library name:
+LIBNAME = libpng15
+PNGMAJ = 15
+# Shared library names:
+LIBSO=$(LIBNAME).dylib
+LIBSOMAJ=$(LIBNAME).$(PNGMAJ).dylib
+LIBSOREL=$(LIBNAME).$(PNGMAJ).$(RELEASE).dylib
+OLDSO=libpng.dylib
+# Utilities:
+CC=cc
+AR_RC=ar rc
+MKDIR_P=mkdir -p
+LN_SF=ln -sf
+RANLIB=ranlib
+RM_F=/bin/rm -f
+ARCH="-arch i386 -arch x86_64"
+# CFLAGS=-I$(ZLIBINC) -W -Wall -O3 -funroll-loops
+CFLAGS=-I$(ZLIBINC) -W -Wall -O -funroll-loops $(ARCH)
+LDFLAGS=-L. -L$(ZLIBLIB) -lpng15 -lz $(ARCH)
+INCPATH=$(prefix)/include
+LIBPATH=$(exec_prefix)/lib
+MANPATH=$(prefix)/man
+BINPATH=$(exec_prefix)/bin
+# override DESTDIR= on the make install command line to easily support
+# installing into a temporary location.  Example:
+#
+#    make install DESTDIR=/tmp/build/libpng
+#
+# If you're going to install into a temporary location
+# via DESTDIR, $(DESTDIR)$(prefix) must already exist before
+# you execute make install.
+DESTDIR=
+DB=$(DESTDIR)$(BINPATH)
+DI=$(DESTDIR)$(INCPATH)
+DL=$(DESTDIR)$(LIBPATH)
+DM=$(DESTDIR)$(MANPATH)
+OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
+        pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
+        pngwtran.o pngmem.o pngerror.o pngpread.o
+OBJSDLL = $(OBJS:.o=.pic.o)
+.SUFFIXES:      .c .o .pic.o
+.c.pic.o:
+        $(CC) -c $(CFLAGS) -fno-common -o $@ $*.c
+all: libpng.a $(LIBSO) pngtest libpng.pc libpng-config
+# see scripts/pnglibconf.mak for more options
+pnglibconf.h: scripts/pnglibconf.h.prebuilt
+        cp scripts/pnglibconf.h.prebuilt $@
+libpng.a: $(OBJS)
+        $(AR_RC) $@ $(OBJS)
+        $(RANLIB) $@
+libpng.pc:
+        cat scripts/libpng.pc.in | sed -e s!@prefix@!$(prefix)! \
+        -e s!@exec_prefix@!$(exec_prefix)! \
+        -e s!@libdir@!$(LIBPATH)! \
+        -e s!@includedir@!$(INCPATH)! \
+        -e s!-lpng15!-lpng15\ -lz! > libpng.pc
+libpng-config:
+        ( cat scripts/libpng-config-head.in; \
+        echo prefix=\"$(prefix)\"; \
+        echo I_opts=\"-I$(INCPATH)/$(LIBNAME)\"; \
+        echo L_opts=\"-L$(LIBPATH)\"; \
+        echo libs=\"-lpng15 -lz\"; \
+        cat scripts/libpng-config-body.in ) > libpng-config
+        chmod +x libpng-config
+$(LIBSO): $(LIBSOMAJ)
+        $(LN_SF) $(LIBSOMAJ) $(LIBSO)
+$(LIBSOMAJ): $(OBJSDLL)
+        $(CC) -dynamiclib \
+         -install_name $(LIBPATH)/$(LIBSOMAJ) \
+         -current_version 15 -compatibility_version 15 \
+         -o $(LIBSOMAJ) \
+         $(OBJSDLL) -L$(ZLIBLIB) -lz
+pngtest: pngtest.o $(LIBSO)
+        $(CC) -o pngtest $(CFLAGS) pngtest.o $(LDFLAGS)
+test: pngtest
+        ./pngtest
+install-headers: png.h pngconf.h pnglibconf.h
+        -@if [ ! -d $(DI) ]; then $(MKDIR_P) $(DI); fi
+        -@if [ ! -d $(DI)/$(LIBNAME) ]; then $(MKDIR_P) $(DI)/$(LIBNAME); fi
+        cp png.h pngconf.h pnglibconf.h $(DI)/$(LIBNAME)
+        chmod 644 $(DI)/$(LIBNAME)/png.h $(DI)/$(LIBNAME)/pngconf.h $(DI)/$(LIBNAME)/pnglibconf.h
+        -@$(RM_F) $(DI)/png.h $(DI)/pngconf.h $(DI)/pnglibconf.h
+        -@$(RM_F) $(DI)/libpng
+        (cd $(DI); $(LN_SF) $(LIBNAME) libpng; $(LN_SF) $(LIBNAME)/* .)
+install-static: install-headers libpng.a
+        -@if [ ! -d $(DL) ]; then $(MKDIR_P) $(DL); fi
+        cp libpng.a $(DL)/$(LIBNAME).a
+        chmod 644 $(DL)/$(LIBNAME).a
+        $(RANLIB) $(DL)/$(LIBNAME).a
+        -@$(RM_F) $(DL)/libpng.a
+        (cd $(DL); $(LN_SF) $(LIBNAME).a libpng.a)
+install-shared: install-headers $(LIBSOMAJ) libpng.pc
+        -@if [ ! -d $(DL) ]; then $(MKDIR_P) $(DL); fi
+        -@$(RM_F) $(DL)/$(LIBSO)
+        -@$(RM_F) $(DL)/$(LIBSOREL)
+        -@$(RM_F) $(DL)/$(OLDSO)
+        cp $(LIBSOMAJ) $(DL)/$(LIBSOREL)
+        chmod 755 $(DL)/$(LIBSOREL)
+        (cd $(DL); \
+        $(LN_SF) $(LIBSOREL) $(LIBSO); \
+        $(LN_SF) $(LIBSO) $(OLDSO))
+        -@if [ ! -d $(DL)/pkgconfig ]; then $(MKDIR_P) $(DL)/pkgconfig; fi
+        -@$(RM_F) $(DL)/pkgconfig/$(LIBNAME).pc
+        -@$(RM_F) $(DL)/pkgconfig/libpng.pc
+        cp libpng.pc $(DL)/pkgconfig/$(LIBNAME).pc
+        chmod 644 $(DL)/pkgconfig/$(LIBNAME).pc
+        (cd $(DL)/pkgconfig; $(LN_SF) $(LIBNAME).pc libpng.pc)
+install-man: libpng.3 libpngpf.3 png.5
+        -@if [ ! -d $(DM) ]; then $(MKDIR_P) $(DM); fi
+        -@if [ ! -d $(DM)/man3 ]; then $(MKDIR_P) $(DM)/man3; fi
+        -@$(RM_F) $(DM)/man3/libpng.3
+        -@$(RM_F) $(DM)/man3/libpngpf.3
+        cp libpng.3 $(DM)/man3
+        cp libpngpf.3 $(DM)/man3
+        -@if [ ! -d $(DM)/man5 ]; then $(MKDIR_P) $(DM)/man5; fi
+        -@$(RM_F) $(DM)/man5/png.5
+        cp png.5 $(DM)/man5
+install-config: libpng-config
+        -@if [ ! -d $(DB) ]; then $(MKDIR_P) $(DB); fi
+        -@$(RM_F) $(DB)/libpng-config
+        -@$(RM_F) $(DB)/$(LIBNAME)-config
+        cp libpng-config $(DB)/$(LIBNAME)-config
+        chmod 755 $(DB)/$(LIBNAME)-config
+        (cd $(DB); $(LN_SF) $(LIBNAME)-config libpng-config)
+install: install-static install-shared install-man install-config
+# If you installed in $(DESTDIR), test-installed won't work until you
+# move the library to its final location.  Use test-dd to test it
+# before then.
+test-dd:
+        echo
+        echo Testing installed dynamic shared library in $(DL).
+        $(CC) -I$(DI) -I$(ZLIBINC) \
+           `$(BINPATH)/$(LIBNAME)-config --cflags` pngtest.c \
+           -L$(DL) -L$(ZLIBLIB) \
+           -o pngtestd `$(BINPATH)/$(LIBNAME)-config --ldflags`
+        ./pngtestd pngtest.png
+test-installed:
+        $(CC) $(CFLAGS) \
+           `$(BINPATH)/$(LIBNAME)-config --cflags` pngtest.c \
+           -L$(ZLIBLIB) \
+           -o pngtesti `$(BINPATH)/$(LIBNAME)-config --ldflags`
+        ./pngtesti pngtest.png
+clean:
+        $(RM_F) *.o libpng.a pngtest pngout.png libpng-config \
+        libpng.pc $(LIBNAME).*dylib pngtesti pnglibconf.h
+DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
+writelock:
+        chmod a-w *.[ch35] $(DOCS) scripts/*
+# DO NOT DELETE THIS LINE -- make depend depends on it.
+png.o png.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngerror.o pngerror.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrio.o pngrio.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwio.o pngwio.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngmem.o pngmem.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngset.o pngset.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngget.o pngget.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngread.o pngread.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrtran.o pngrtran.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrutil.o pngrutil.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtrans.o pngtrans.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwrite.o pngwrite.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwtran.o pngwtran.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwutil.o pngwutil.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngpread.o pngpread.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtest.o: png.h pngconf.h pnglibconf.h
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.dec b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.dec
new file mode 100644
index 0000000..5687ca1
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.dec
@@ -0,0 +1,202 @@
+# makefile for libpng on DEC Alpha Unix
+# Copyright (C) 2000-2002, 2006, 2010-2011 Glenn Randers-Pehrson
+# Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
+#
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+# Library name:
+PNGMAJ = 15
+LIBNAME = libpng15
+# Shared library names:
+LIBSO=$(LIBNAME).so
+LIBSOMAJ=$(LIBNAME).so.$(PNGMAJ)
+LIBSOREL=$(LIBSOMAJ).$(RELEASE)
+OLDSO=libpng.so
+# Utilities:
+AR_RC=ar rc
+CC=cc
+MKDIR_P=mkdir
+LN_SF=ln -f -s
+RANLIB=ranlib
+RM_F=/bin/rm -f
+# where make install puts libpng.a and png.h
+prefix=/usr/local
+exec_prefix=$(prefix)
+INCPATH=$(prefix)/include
+LIBPATH=$(exec_prefix)/lib
+MANPATH=$(prefix)/man
+BINPATH=$(exec_prefix)/bin
+# override DESTDIR= on the make install command line to easily support
+# installing into a temporary location.  Example:
+#
+#    make install DESTDIR=/tmp/build/libpng
+#
+# If you're going to install into a temporary location
+# via DESTDIR, $(DESTDIR)$(prefix) must already exist before
+# you execute make install.
+DESTDIR=
+DB=$(DESTDIR)$(BINPATH)
+DI=$(DESTDIR)$(INCPATH)
+DL=$(DESTDIR)$(LIBPATH)
+DM=$(DESTDIR)$(MANPATH)
+# Where the zlib library and include files are located
+#ZLIBLIB=/usr/local/lib
+#ZLIBINC=/usr/local/include
+ZLIBLIB=../zlib
+ZLIBINC=../zlib
+CFLAGS=-std -w1 -I$(ZLIBINC) -O # -g -DPNG_DEBUG=1
+LDFLAGS=-L$(ZLIBLIB) -rpath $(ZLIBLIB) libpng.a -lz -lm
+OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
+        pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
+        pngwtran.o pngmem.o pngerror.o pngpread.o
+all: $(LIBSO) libpng.a pngtest libpng.pc libpng-config
+# see scripts/pnglibconf.mak for more options
+pnglibconf.h: scripts/pnglibconf.h.prebuilt
+        cp scripts/pnglibconf.h.prebuilt $@
+libpng.a: $(OBJS)
+        $(AR_RC) $@  $(OBJS)
+        $(RANLIB) $@
+libpng.pc:
+        cat scripts/libpng.pc.in | sed -e s!@prefix@!$(prefix)! \
+        -e s!@exec_prefix@!$(exec_prefix)! \
+        -e s!@libdir@!$(LIBPATH)! \
+        -e s!@includedir@!$(INCPATH)! \
+        -e s!-lpng15!-lpng15\ -lz\ -lm! > libpng.pc
+libpng-config:
+        ( cat scripts/libpng-config-head.in; \
+        echo prefix=\"$(prefix)\"; \
+        echo I_opts=\"-I$(INCPATH)/$(LIBNAME)\"; \
+        echo ccopts=\"-std\"; \
+        echo L_opts=\"-L$(LIBPATH)\"; \
+        echo libs=\"-lpng15 -lz -lm\"; \
+        cat scripts/libpng-config-body.in ) > libpng-config
+        chmod +x libpng-config
+$(LIBSO): $(LIBSOMAJ)
+        $(LN_SF) $(LIBSOMAJ) $(LIBSO)
+$(LIBSOMAJ): $(OBJS)
+        $(CC) -shared -o $@ $(OBJS) -L$(ZLIBLIB) \
+        -soname $(LIBSOMAJ)
+pngtest: pngtest.o libpng.a
+        $(CC) -o pngtest $(CFLAGS) pngtest.o $(LDFLAGS)
+test: pngtest
+        ./pngtest
+install-headers: png.h pngconf.h pnglibconf.h
+        -@if [ ! -d $(DI) ]; then $(MKDIR_P) $(DI); fi
+        -@if [ ! -d $(DI)/$(LIBNAME) ]; then $(MKDIR_P) $(DI)/$(LIBNAME); fi
+        cp png.h pngconf.h pnglibconf.h $(DI)/$(LIBNAME)
+        chmod 644 $(DI)/$(LIBNAME)/png.h $(DI)/$(LIBNAME)/pngconf.h $(DI)/$(LIBNAME)/pnglibconf.h
+        -@/bin/rm -f $(DI)/png.h $(DI)/pngconf.h $(DI)/pnglibconf.h
+        -@/bin/rm -f $(DI)/libpng
+        (cd $(DI); $(LN_SF)(LIBNAME) libpng; $(LN_SF)(LIBNAME)/* .)
+install-static: install-headers libpng.a
+        -@if [ ! -d $(DL) ]; then $(MKDIR_P) $(DL); fi
+        cp libpng.a $(DL)/$(LIBNAME).a
+        chmod 644 $(DL)/$(LIBNAME).a
+        -@/bin/rm -f $(DL)/libpng.a
+        (cd $(DL); $(LN_SF)(LIBNAME).a libpng.a)
+install-shared: install-headers $(LIBSOMAJ) libpng.pc
+        -@if [ ! -d $(DL) ]; then $(MKDIR_P) $(DL); fi
+        -@$(RM_F) $(DL)/$(LIBSO)
+        -@$(RM_F) $(DL)/$(LIBSOREL)
+        -@$(RM_F) $(DL)/$(OLDSO)
+        cp $(LIBSOMAJ) $(DL)/$(LIBSOREL)
+        chmod 755 $(DL)/$(LIBSOREL)
+        (cd $(DL); \
+        $(LN_SF) $(LIBSOREL) $(LIBSO); \
+        $(LN_SF) $(LIBSO) $(OLDSO))
+        -@if [ ! -d $(DL)/pkgconfig ]; then $(MKDIR_P) $(DL)/pkgconfig; fi
+        -@$(RM_F) $(DL)/pkgconfig/$(LIBNAME).pc
+        -@$(RM_F) $(DL)/pkgconfig/libpng.pc
+        cp libpng.pc $(DL)/pkgconfig/$(LIBNAME).pc
+        chmod 644 $(DL)/pkgconfig/$(LIBNAME).pc
+        (cd $(DL)/pkgconfig; $(LN_SF) $(LIBNAME).pc libpng.pc)
+install-man: libpng.3 libpngpf.3 png.5
+        -@if [ ! -d $(DM) ]; then $(MKDIR_P) $(DM); fi
+        -@if [ ! -d $(DM)/man3 ]; then $(MKDIR_P) $(DM)/man3; fi
+        -@/bin/rm -f $(DM)/man3/libpng.3
+        -@/bin/rm -f $(DM)/man3/libpngpf.3
+        cp libpng.3 $(DM)/man3
+        cp libpngpf.3 $(DM)/man3
+        -@if [ ! -d $(DM)/man5 ]; then $(MKDIR_P) $(DM)/man5; fi
+        -@/bin/rm -f $(DM)/man5/png.5
+        cp png.5 $(DM)/man5
+install-config: libpng-config
+        -@if [ ! -d $(DB) ]; then $(MKDIR_P) $(DB); fi
+        -@/bin/rm -f $(DB)/libpng-config
+        -@/bin/rm -f $(DB)/$(LIBNAME)-config
+        cp libpng-config $(DB)/$(LIBNAME)-config
+        chmod 755 $(DB)/$(LIBNAME)-config
+        (cd $(DB); $(LN_SF)(LIBNAME)-config libpng-config)
+install: install-static install-shared install-man install-config
+# If you installed in $(DESTDIR), test-installed won't work until you
+# move the library to its final location.  Use test-dd to test it
+# before then.
+test-dd:
+        echo
+        echo Testing installed dynamic shared library in $(DL).
+        $(CC) -w1 -I$(DI) -I$(ZLIBINC) \
+           `$(BINPATH)/$(LIBNAME)-config --cflags` pngtest.c \
+           -L$(DL) -L$(ZLIBLIB)  -R$(ZLIBLIB) -R$(DL) \
+           -o pngtestd `$(BINPATH)/$(LIBNAME)-config --ldflags`
+        ./pngtestd pngtest.png
+test-installed:
+        echo
+        echo Testing installed dynamic shared library.
+        $(CC) -w1 -I$(ZLIBINC) \
+           `$(BINPATH)/$(LIBNAME)-config --cflags` pngtest.c \
+           -L$(ZLIBLIB) -R$(ZLIBLIB) \
+           -o pngtesti `$(BINPATH)/$(LIBNAME)-config --ldflags`
+        ./pngtesti pngtest.png
+clean:
+        /bin/rm -f *.o libpng.a pngtest pngtesti pngout.png \
+        libpng-config $(LIBSO) $(LIBSOMAJ)* \
+        libpng.pc pnglibconf.h
+# DO NOT DELETE THIS LINE -- make depend depends on it.
+png.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngerror.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrio.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwio.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngmem.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngset.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngget.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngread.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrtran.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrutil.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtrans.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwrite.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwtran.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwutil.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngpread.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtest.o: png.h pngconf.h pnglibconf.h
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.dj2 b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.dj2
new file mode 100644
index 0000000..48fea81
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.dj2
@@ -0,0 +1,62 @@
+# DJGPP (DOS gcc) makefile for libpng
+# Copyright (C) 2002, 2006, 2009-2010-2011 Glenn Randers-Pehrson
+# Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
+#
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+# where make install will put libpng.a and png.h
+#prefix=/usr/local
+prefix=.
+INCPATH=$(prefix)/include
+LIBPATH=$(prefix)/lib
+CC=gcc
+CFLAGS=-I../zlib -O -DPNG_NO_SNPRINTF
+LDFLAGS=-L. -L../zlib/ -lpng -lz -lm
+RANLIB=ranlib
+OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
+        pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o pngwtran.o \
+        pngmem.o pngerror.o pngpread.o
+all: libpng.a pngtest
+# see scripts/pnglibconf.mak for more options
+pnglibconf.h: scripts/pnglibconf.h.prebuilt
+        cp scripts/pnglibconf.h.prebuilt $@
+libpng.a: $(OBJS)
+        ar rc $@  $(OBJS)
+        $(RANLIB) $@
+pngtest: pngtest.o libpng.a
+        $(CC) -o pngtest $(CFLAGS) pngtest.o $(LDFLAGS)
+        coff2exe pngtest
+test: pngtest
+        ./pngtest
+clean:
+        rm -f *.o libpng.a pngtest pngout.png pnglibconf.h
+# DO NOT DELETE THIS LINE -- make depend depends on it.
+png.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngerror.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrio.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwio.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngmem.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngset.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngget.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngread.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngpread.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrtran.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrutil.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtrans.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwrite.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwtran.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwutil.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtest.o: png.h pngconf.h pnglibconf.h
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.elf b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.elf
new file mode 100644
index 0000000..ceea7fc
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.elf
@@ -0,0 +1,263 @@
+# makefile for libpng.a and libpng15.so on Linux ELF with gcc
+# Copyright (C) 1998, 1999, 2002, 2006, 2008, 2010-2011 Greg Roelofs
+# and Glenn Randers-Pehrson
+# Copyright (C) 1996, 1997 Andreas Dilger
+#
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+# Modified for Debian by Junichi Uekawa and Josselin Mouette
+# Major modifications are:
+#    * link libpng explicitly with libz and libm
+#    * $(OLDSO).15 is a symlink rather than a different library
+#    * versioned symbols
+# Library name:
+LIBNAME = libpng15
+PNGMAJ = 15
+# Shared library names:
+LIBSO=$(LIBNAME).so
+LIBSOMAJ=$(LIBNAME).so.$(PNGMAJ)
+LIBSOREL=$(LIBSOMAJ).$(RELEASE)
+OLDSO=libpng.so
+OLDSOMAJ=libpng.so.15
+# Utilities:
+AR_RC=ar rc
+CC=gcc
+MKDIR_P=mkdir -p
+LN_SF=ln -sf
+RANLIB=ranlib
+RM_F=/bin/rm -f
+# where "make install" puts libpng15.a, libpng15.so*,
+# libpng15/png.h, libpng15/pngconf.h, and libpng15/pnglibconf.h
+# Prefix must be a full pathname.
+prefix=/usr/local
+exec_prefix=$(prefix)
+# Where the zlib library and include files are located.
+ZLIBLIB=/usr/local/lib
+ZLIBINC=/usr/local/include
+# ZLIBLIB=../zlib
+# ZLIBINC=../zlib
+ALIGN=
+# for i386:
+#ALIGN=-malign-loops=2 -malign-functions=2
+WARNMORE=-Wwrite-strings -Wpointer-arith -Wshadow \
+        -Wmissing-declarations -Wtraditional -Wcast-align \
+        -Wstrict-prototypes -Wmissing-prototypes #-Wconversion
+# for pgcc version 2.95.1, -O3 is buggy; don't use it.
+CFLAGS=-W -Wall -D_REENTRANT -O2 \
+        $(ALIGN) # $(WARNMORE) -g -DPNG_DEBUG=5
+LDFLAGS=-L. -lpng15
+LDFLAGS_A=libpng.a -lz -lm
+LIBADDFLAGS=-lz -lm
+INCPATH=$(prefix)/include
+LIBPATH=$(exec_prefix)/lib
+MANPATH=$(prefix)/man
+BINPATH=$(exec_prefix)/bin
+# override DESTDIR= on the make install command line to easily support
+# installing into a temporary location.  Example:
+#
+#    make install DESTDIR=/tmp/build/libpng
+#
+# If you're going to install into a temporary location
+# via DESTDIR, $(DESTDIR)$(prefix) must already exist before
+# you execute make install.
+DESTDIR=
+DB=$(DESTDIR)$(BINPATH)
+DI=$(DESTDIR)$(INCPATH)
+DL=$(DESTDIR)$(LIBPATH)
+DM=$(DESTDIR)$(MANPATH)
+OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
+        pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
+        pngwtran.o pngmem.o pngerror.o pngpread.o
+OBJSDLL = $(OBJS:.o=.pic.o)
+.SUFFIXES:      .c .o .pic.o
+.c.pic.o:
+        $(CC) -c $(CFLAGS) -fPIC -o $@ $*.c
+all: libpng.a $(LIBSO) pngtest pngtest-static libpng.pc libpng-config
+# see scripts/pnglibconf.mak for more options
+pnglibconf.h: scripts/pnglibconf.h.prebuilt
+        cp scripts/pnglibconf.h.prebuilt $@
+libpng.a: $(OBJS)
+        $(AR_RC) $@ $(OBJS)
+        $(RANLIB) $@
+libpng.pc:
+        cat scripts/libpng.pc.in | sed -e s!@prefix@!$(prefix)! \
+        -e s!@exec_prefix@!$(exec_prefix)! \
+        -e s!@libdir@!$(LIBPATH)! \
+        -e s!@includedir@!$(INCPATH)! \
+        -e s!-lpng15!-lpng15\ -lz\ -lm! > libpng.pc
+libpng.syms: png.h pngconf.h pnglibconf.h
+        $(CC) $(CFLAGS) -E -DPNG_BUILDSYMS -DPNG_INTERNAL png.h |\
+        awk -F '[\t [\\]();]' -v PNGMAJ=$(PNGMAJ) 'BEGIN{printf("PNG15_%s {global:\n",PNGMAJ)}\
+        { for (i=1;i+2<=NF;++i)\
+                if ($$(i)=="PNG_FUNCTION_EXPORT" && $$(i+2)=="END")\
+                        print $$(i+1) ";";\
+        for (i=1;i+1<=NF;++i)\
+                if ($$(i)=="PNG_DATA_EXPORT")\
+                        print $$(i+1) ";";}\
+        END{print "local: *; };"}' >$@.new
+        $(RM_F) $@
+        mv $@.new $@
+libpng-config:
+        ( cat scripts/libpng-config-head.in; \
+        echo prefix=\"$(prefix)\"; \
+        echo I_opts=\"-I$(INCPATH)/$(LIBNAME)\"; \
+        echo L_opts=\"\"; \
+        echo R_opts=\"\"; \
+        echo libs=\"-lpng15\"; \
+        echo all_libs=\"-lpng15 $(LIBADDFLAGS)\"; \
+        cat scripts/libpng-config-body.in ) > libpng-config
+        chmod +x libpng-config
+$(LIBSO): $(LIBSOMAJ)
+        $(LN_SF) $(LIBSOMAJ) $(LIBSO)
+$(LIBSOMAJ): $(OBJSDLL) libpng.syms
+        $(CC) -shared -Wl,-soname,$(LIBSOMAJ) \
+        -Wl,-version-script,libpng.syms \
+        -o $(LIBSOMAJ) \
+        $(OBJSDLL)
+pngtest: pngtest.o $(LIBSO)
+        $(CC) -o pngtest $(CFLAGS) pngtest.o $(LDFLAGS)
+pngtest-static: pngtest.o libpng.a
+        $(CC) -o pngtest-static $(CFLAGS) pngtest.o $(LDFLAGS_A)
+test: pngtest pngtest-static
+        @echo ""
+        @echo "   Running pngtest dynamically linked with $(LIBSO):"
+        @echo ""
+        LD_LIBRARY_PATH=".:${LD_LIBRARY_PATH}" ./pngtest
+        @echo ""
+        @echo "   Running pngtest statically linked with libpng.a:"
+        @echo ""
+        ./pngtest-static
+install-headers: png.h pngconf.h pnglibconf.h
+        -@if [ ! -d $(DI) ]; then $(MKDIR_P) $(DI); fi
+        -@if [ ! -d $(DI)/$(LIBNAME) ]; then $(MKDIR_P) $(DI)/$(LIBNAME); fi
+        cp png.h pngconf.h pnglibconf.h $(DI)/$(LIBNAME)
+        chmod 644 $(DI)/$(LIBNAME)/png.h $(DI)/$(LIBNAME)/pngconf.h $(DI)/$(LIBNAME)/pnglibconf.h
+        -@$(RM_F) $(DI)/png.h $(DI)/pngconf.h $(DI)/pnglibconf.h
+        -@$(RM_F) $(DI)/libpng
+        (cd $(DI); $(LN_SF) $(LIBNAME) libpng; $(LN_SF) $(LIBNAME)/* .)
+install-static: install-headers libpng.a
+        -@if [ ! -d $(DL) ]; then $(MKDIR_P) $(DL); fi
+        cp libpng.a $(DL)/$(LIBNAME).a
+        chmod 644 $(DL)/$(LIBNAME).a
+        -@$(RM_F) $(DL)/libpng.a
+        (cd $(DL); $(LN_SF) $(LIBNAME).a libpng.a)
+install-shared: install-headers $(LIBSOMAJ) libpng.pc
+        -@if [ ! -d $(DL) ]; then $(MKDIR_P) $(DL); fi
+        -@$(RM_F) $(DL)/$(LIBSO)
+        -@$(RM_F) $(DL)/$(LIBSOREL)
+        -@$(RM_F) $(DL)/$(OLDSO)
+        cp $(LIBSOMAJ) $(DL)/$(LIBSOREL)
+        chmod 755 $(DL)/$(LIBSOREL)
+        (cd $(DL); \
+        $(LN_SF) $(LIBSOREL) $(LIBSO); \
+        $(LN_SF) $(LIBSO) $(OLDSO))
+        -@if [ ! -d $(DL)/pkgconfig ]; then $(MKDIR_P) $(DL)/pkgconfig; fi
+        -@$(RM_F) $(DL)/pkgconfig/$(LIBNAME).pc
+        -@$(RM_F) $(DL)/pkgconfig/libpng.pc
+        cp libpng.pc $(DL)/pkgconfig/$(LIBNAME).pc
+        chmod 644 $(DL)/pkgconfig/$(LIBNAME).pc
+        (cd $(DL)/pkgconfig; $(LN_SF) $(LIBNAME).pc libpng.pc)
+install-man: libpng.3 libpngpf.3 png.5
+        -@if [ ! -d $(DM) ]; then $(MKDIR_P) $(DM); fi
+        -@if [ ! -d $(DM)/man3 ]; then $(MKDIR_P) $(DM)/man3; fi
+        -@$(RM_F) $(DM)/man3/libpng.3
+        -@$(RM_F) $(DM)/man3/libpngpf.3
+        cp libpng.3 $(DM)/man3
+        cp libpngpf.3 $(DM)/man3
+        -@if [ ! -d $(DM)/man5 ]; then $(MKDIR_P) $(DM)/man5; fi
+        -@$(RM_F) $(DM)/man5/png.5
+        cp png.5 $(DM)/man5
+install-config: libpng-config
+        -@if [ ! -d $(DB) ]; then $(MKDIR_P) $(DB); fi
+        -@$(RM_F) $(DB)/libpng-config
+        -@$(RM_F) $(DB)/$(LIBNAME)-config
+        cp libpng-config $(DB)/$(LIBNAME)-config
+        chmod 755 $(DB)/$(LIBNAME)-config
+        (cd $(DB); $(LN_SF) $(LIBNAME)-config libpng-config)
+install: install-static install-shared install-man install-config
+# If you installed in $(DESTDIR), test-installed won't work until you
+# move the library to its final location.  Use test-dd to test it
+# before then.
+test-dd:
+        echo
+        echo Testing installed dynamic shared library in $(DL).
+        $(CC) -I$(DI) -I$(ZLIBINC) \
+           `$(BINPATH)/$(LIBNAME)-config --cflags` pngtest.c \
+           -L$(DL) -L$(ZLIBLIB) -Wl, -rpath,$(DL) -Wl,-rpath,$(ZLIBLIB) \
+           -o pngtestd `$(BINPATH)/$(LIBNAME)-config --ldflags`
+        ./pngtestd pngtest.png
+test-installed:
+        $(CC) -I$(ZLIBINC) \
+           `$(BINPATH)/$(LIBNAME)-config --cflags` pngtest.c \
+           -L$(ZLIBLIB) -Wl,-rpath,$(ZLIBLIB) \
+           -o pngtesti `$(BINPATH)/$(LIBNAME)-config --ldflags`
+        ./pngtesti pngtest.png
+clean:
+        $(RM_F) *.o libpng.a libpng.syms pngtest pngout.png libpng-config \
+        $(LIBSO) $(LIBSOMAJ)* pngtest-static pngtesti \
+        libpng.pc pnglibconf.h
+DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
+writelock:
+        chmod a-w *.[ch35] $(DOCS) scripts/*
+# DO NOT DELETE THIS LINE -- make depend depends on it.
+png.o png.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngerror.o pngerror.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrio.o pngrio.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwio.o pngwio.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngmem.o pngmem.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngset.o pngset.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngget.o pngget.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngread.o pngread.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrtran.o pngrtran.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrutil.o pngrutil.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtrans.o pngtrans.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwrite.o pngwrite.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwtran.o pngwtran.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwutil.o pngwutil.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngpread.o pngpread.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtest.o: png.h pngconf.h pnglibconf.h
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.freebsd b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.freebsd
new file mode 100644
index 0000000..ced7be2
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.freebsd
@@ -0,0 +1,53 @@
+# makefile for libpng under FreeBSD
+# Copyright (C) 2002, 2007, 2009 Glenn Randers-Pehrson and Andrey A. Chernov
+#
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+PREFIX?=        /usr/local
+SHLIB_VER?=     15
+LIB=            png
+SHLIB_MAJOR=    ${SHLIB_VER}
+SHLIB_MINOR=    0
+NOPROFILE=      YES
+NOOBJ=          YES
+# where make install puts libpng.a and png.h
+DESTDIR=        ${PREFIX}
+LIBDIR=         /lib
+INCS=           png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+INCSDIR=        /include/libpng
+INCDIR=         ${INCSDIR}              # for 4.x bsd.lib.mk
+MAN=            libpng.3 libpngpf.3 png.5
+MANDIR=         /man/man
+SYMLINKS=       libpng/png.h ${INCSDIR}/../png.h \
+                libpng/pngconf.h ${INCSDIR}/../pngconf.h \
+                libpng/pnglibconf.h ${INCSDIR}/../pnglibconf.h
+LDADD+=         -lm -lz
+DPADD+=         ${LIBM} ${LIBZ}
+CFLAGS+= -I.
+SRCS=   png.c pngset.c pngget.c pngrutil.c pngtrans.c pngwutil.c \
+        pngread.c pngrio.c pngwio.c pngwrite.c pngrtran.c \
+        pngwtran.c pngmem.c pngerror.c pngpread.c
+pngtest: pngtest.o libpng.a
+        ${CC} ${CFLAGS} -L. -static -o pngtest pngtest.o -lpng -lz -lm
+CLEANFILES= pngtest pngtest.o pngout.png
+test: pngtest
+        ./pngtest
+# see scripts/pnglibconf.mak for more options
+pnglibconf.h: scripts/pnglibconf.h.prebuilt
+        cp scripts/pnglibconf.h.prebuilt $@
+DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
+writelock:
+        chmod a-w *.[ch35] $(DOCS) scripts/*
+.include <bsd.lib.mk>
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.gcc b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.gcc
new file mode 100644
index 0000000..c871f7d
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.gcc
@@ -0,0 +1,87 @@
+# makefile for libpng using gcc (generic, static library)
+# Copyright (C) 2008 Glenn Randers-Pehrson
+# Copyright (C) 2000 Cosmin Truta
+# Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
+#
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+# Location of the zlib library and include files
+ZLIBINC = ../zlib
+ZLIBLIB = ../zlib
+# Compiler, linker, lib and other tools
+CC = gcc
+LD = $(CC)
+AR_RC = ar rcs
+RANLIB = ranlib
+RM_F = rm -f
+CDEBUG = -g -DPNG_DEBUG=5
+LDDEBUG =
+CRELEASE = -O2
+LDRELEASE = -s
+#CFLAGS = -W -Wall $(CDEBUG)
+CFLAGS = -W -Wall $(CRELEASE)
+#LDFLAGS = $(LDDEBUG)
+LDFLAGS = $(LDRELEASE)
+LIBS = -lz -lm
+# File extensions
+O=.o
+A=.a
+EXE=
+# Variables
+OBJS =  png$(O) pngerror$(O) pngget$(O) pngmem$(O) pngpread$(O) \
+        pngread$(O) pngrio$(O) pngrtran$(O) pngrutil$(O) pngset$(O) \
+        pngtrans$(O) pngwio$(O) pngwrite$(O) pngwtran$(O) pngwutil$(O)
+# Targets
+all: static
+# see scripts/pnglibconf.mak for more options
+pnglibconf.h: scripts/pnglibconf.h.prebuilt
+        cp scripts/pnglibconf.h.prebuilt $@
+.c$(O):
+        $(CC) -c $(CFLAGS) -I$(ZLIBINC) $<
+static: libpng$(A) pngtest$(EXE)
+shared:
+        @echo This is a generic makefile that cannot create shared libraries.
+        @echo Please use a configuration that is specific to your platform.
+        @false
+libpng$(A): $(OBJS)
+        $(AR_RC) $@ $(OBJS)
+        $(RANLIB) $@
+test: pngtest$(EXE)
+        ./pngtest$(EXE)
+pngtest$(EXE): pngtest$(O) libpng$(A)
+        $(LD) $(LDFLAGS) -L$(ZLIBLIB) -o $@ pngtest$(O) libpng$(A) $(LIBS)
+clean:
+        $(RM_F) *$(O) libpng$(A) pngtest$(EXE) pngout.png pnglibconf.h
+png$(O):      png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngerror$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngget$(O):   png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngmem$(O):   png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngpread$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngread$(O):  png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrio$(O):   png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrtran$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrutil$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngset$(O):   png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtrans$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwio$(O):   png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwrite$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwtran$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwutil$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtest$(O):  png.h pngconf.h pnglibconf.h
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.hp64 b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.hp64
new file mode 100644
index 0000000..0f4f7ac
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.hp64
@@ -0,0 +1,224 @@
+# makefile for libpng, HPUX (10.20 and 11.00) using the ANSI/C product.
+# Copyright (C) 1999-2002, 2006, 2009, 2010-2011 Glenn Randers-Pehrson
+# Copyright (C) 1995 Guy Eric Schalnat, Group 42
+# contributed by Jim Rice and updated by Chris Schleicher, Hewlett Packard
+#
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+# Where the zlib library and include files are located
+ZLIBLIB=/opt/zlib/lib
+ZLIBINC=/opt/zlib/include
+# Note that if you plan to build a libpng shared library, zlib must also
+# be a shared library, which zlib's configure does not do.  After running
+# zlib's configure, edit the appropriate lines of makefile to read:
+#   CFLAGS=-O1 -DHAVE_UNISTD -DUSE_MAP -fPIC \
+#   LDSHARED=ld -b
+#   SHAREDLIB=libz.sl
+# Library name:
+LIBNAME = libpng15
+PNGMAJ = 15
+# Shared library names:
+LIBSO=$(LIBNAME).sl
+LIBSOMAJ=$(LIBNAME).sl.$(PNGMAJ)
+LIBSOREL=$(LIBSOMAJ).$(RELEASE)
+OLDSO=libpng.sl
+# Utilities:
+AR_RC=ar rc
+CC=cc
+MKDIR_P=mkdir -p
+LN_SF=ln -sf
+RANLIB=ranlib
+RM_F=/bin/rm -f
+CFLAGS=-I$(ZLIBINC) -O -Ae -Wl,+vnocompatwarnings +DD64 \
+-D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 +Z -DHAVE_UNISTD_H -DUSE_MMAP
+# Caution: be sure you have built zlib with the same CFLAGS.
+CCFLAGS=-I$(ZLIBINC) -O -Ae -Wl,+vnocompatwarnings +DD64 \
+-D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 +Z -DHAVE_UNISTD_H -DUSE_MMAP
+LDFLAGS=-L. -L$(ZLIBLIB) -lpng -lz -lm
+# where make install puts libpng.a, libpng15.sl, and png.h
+prefix=/opt/libpng
+exec_prefix=$(prefix)
+INCPATH=$(prefix)/include
+LIBPATH=$(exec_prefix)/lib
+MANPATH=$(prefix)/man
+BINPATH=$(exec_prefix)/bin
+# override DESTDIR= on the make install command line to easily support
+# installing into a temporary location.  Example:
+#
+#    make install DESTDIR=/tmp/build/libpng
+#
+# If you're going to install into a temporary location
+# via DESTDIR, $(DESTDIR)$(prefix) must already exist before
+# you execute make install.
+DESTDIR=
+DB=$(DESTDIR)$(BINPATH)
+DI=$(DESTDIR)$(INCPATH)
+DL=$(DESTDIR)$(LIBPATH)
+DM=$(DESTDIR)$(MANPATH)
+OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
+        pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
+        pngwtran.o pngmem.o pngerror.o pngpread.o
+OBJSDLL = $(OBJS:.o=.pic.o)
+.SUFFIXES:      .c .o .pic.o
+.c.pic.o:
+        $(CC) -c $(CFLAGS) +z -o $@ $*.c
+all: libpng.a $(LIBSO) pngtest libpng.pc libpng-config
+# see scripts/pnglibconf.mak for more options
+pnglibconf.h: scripts/pnglibconf.h.prebuilt
+        cp scripts/pnglibconf.h.prebuilt $@
+libpng.a: $(OBJS)
+        $(AR_RC) $@ $(OBJS)
+        $(RANLIB) $@
+libpng.pc:
+        cat scripts/libpng.pc.in | sed -e s!@prefix@!$(prefix)! \
+        -e s!@exec_prefix@!$(exec_prefix)! \
+        -e s!@libdir@!$(LIBPATH)! \
+        -e s!@includedir@!$(INCPATH)! \
+        -e s!-lpng15!-lpng15\ -lz\ -lm! > libpng.pc
+libpng-config:
+        ( cat scripts/libpng-config-head.in; \
+        echo prefix=\"$(prefix)\"; \
+        echo I_opts=\"-I$(INCPATH)/$(LIBNAME)\"; \
+        echo ccopts=\"-Ae +DA1.1 +DS2.0\"; \
+        echo L_opts=\"-L$(LIBPATH)\"; \
+        echo libs=\"-lpng15 -lz -lm\"; \
+        cat scripts/libpng-config-body.in ) > libpng-config
+        chmod +x libpng-config
+$(LIBSO): $(LIBSOMAJ)
+        $(LN_SF) $(LIBSOMAJ) $(LIBSO)
+$(LIBSOMAJ): $(OBJSDLL)
+        $(LD) -b +s \
+        +h $(LIBSOMAJ) -o $(LIBSOMAJ) $(OBJSDLL)
+pngtest: pngtest.o libpng.a
+        $(CC) -o pngtest $(CCFLAGS) pngtest.o $(LDFLAGS)
+test: pngtest
+        ./pngtest
+install-headers: png.h pngconf.h pnglibconf.h
+        -@if [ ! -d $(DI) ]; then $(MKDIR_P) $(DI); fi
+        -@if [ ! -d $(DI)/$(LIBNAME) ]; then $(MKDIR_P) $(DI)/$(LIBNAME); fi
+        cp png.h pngconf.h pnglibconf.h $(DI)/$(LIBNAME)
+        chmod 644 $(DI)/$(LIBNAME)/png.h $(DI)/$(LIBNAME)/pngconf.h $(DI)/$(LIBNAME)/pnglibconf.h
+        -@$(RM_F) $(DI)/png.h $(DI)/pngconf.h $(DI)/pnglibconf.h
+        -@$(RM_F) $(DI)/libpng
+        (cd $(DI); $(LN_SF) $(LIBNAME) libpng; $(LN_SF) $(LIBNAME)/* .)
+install-static: install-headers libpng.a
+        -@if [ ! -d $(DL) ]; then $(MKDIR_P) $(DL); fi
+        cp libpng.a $(DL)/$(LIBNAME).a
+        chmod 644 $(DL)/$(LIBNAME).a
+        -@$(RM_F) $(DL)/libpng.a
+        (cd $(DL); $(LN_SF) $(LIBNAME).a libpng.a)
+install-shared: install-headers $(LIBSOMAJ) libpng.pc
+        -@if [ ! -d $(DL) ]; then $(MKDIR_P) $(DL); fi
+        -@$(RM_F) $(DL)/$(LIBSO)
+        -@$(RM_F) $(DL)/$(LIBSOREL)
+        -@$(RM_F) $(DL)/$(OLDSO)
+        cp $(LIBSOMAJ) $(DL)/$(LIBSOREL)
+        chmod 755 $(DL)/$(LIBSOREL)
+        (cd $(DL); \
+        $(LN_SF) $(LIBSOREL) $(LIBSO); \
+        $(LN_SF) $(LIBSO) $(OLDSO))
+        -@if [ ! -d $(DL)/pkgconfig ]; then $(MKDIR_P) $(DL)/pkgconfig; fi
+        -@$(RM_F) $(DL)/pkgconfig/$(LIBNAME).pc
+        -@$(RM_F) $(DL)/pkgconfig/libpng.pc
+        cp libpng.pc $(DL)/pkgconfig/$(LIBNAME).pc
+        chmod 644 $(DL)/pkgconfig/$(LIBNAME).pc
+        (cd $(DL)/pkgconfig; $(LN_SF) $(LIBNAME).pc libpng.pc)
+install-man: libpng.3 libpngpf.3 png.5
+        -@if [ ! -d $(DM) ]; then $(MKDIR_P) $(DM); fi
+        -@if [ ! -d $(DM)/man3 ]; then $(MKDIR_P) $(DM)/man3; fi
+        -@$(RM_F) $(DM)/man3/libpng.3
+        -@$(RM_F) $(DM)/man3/libpngpf.3
+        cp libpng.3 $(DM)/man3
+        cp libpngpf.3 $(DM)/man3
+        -@if [ ! -d $(DM)/man5 ]; then $(MKDIR_P) $(DM)/man5; fi
+        -@$(RM_F) $(DM)/man5/png.5
+        cp png.5 $(DM)/man5
+install-config: libpng-config
+        -@if [ ! -d $(DB) ]; then $(MKDIR_P) $(DB); fi
+        -@$(RM_F) $(DB)/libpng-config
+        -@$(RM_F) $(DB)/$(LIBNAME)-config
+        cp libpng-config $(DB)/$(LIBNAME)-config
+        chmod 755 $(DB)/$(LIBNAME)-config
+        (cd $(DB); $(LN_SF) $(LIBNAME)-config libpng-config)
+install: install-static install-shared install-man install-config
+# If you installed in $(DESTDIR), test-installed won't work until you
+# move the library to its final location.  Use test-dd to test it
+# before then.
+test-dd:
+        echo
+        echo Testing installed dynamic shared library in $(DL).
+        $(CC) -I$(DI) -I$(ZLIBINC) $(CCFLAGS) \
+           `$(BINPATH)/$(LIBNAME)-config --cflags` pngtest.c \
+           -L$(DL) -L$(ZLIBLIB) \
+           -o pngtestd `$(BINPATH)/$(LIBNAME)-config --ldflags`
+        ./pngtestd pngtest.png
+test-installed:
+        echo
+        echo Testing installed dynamic shared library.
+        $(CC) $(CCFLAGS) \
+           `$(BINPATH)/$(LIBNAME)-config --cflags` pngtest.c \
+           -L$(ZLIBLIB) \
+           -o pngtesti `$(BINPATH)/$(LIBNAME)-config --ldflags`
+        ./pngtesti pngtest.png
+clean:
+        $(RM_F) *.o libpng.a pngtest pngtesti pngout.png \
+        libpng-config $(LIBSO) $(LIBSOMAJ)* \
+        libpng.pc pnglibconf.h
+DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
+writelock:
+        chmod a-w *.[ch35] $(DOCS) scripts/*
+# DO NOT DELETE THIS LINE -- make depend depends on it.
+png.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngerror.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrio.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwio.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngmem.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngset.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngget.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngread.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrtran.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrutil.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtrans.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwrite.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwtran.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwutil.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngpread.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtest.o: png.h pngconf.h pnglibconf.h
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.hpgcc b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.hpgcc
new file mode 100644
index 0000000..28ca7bb
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.hpgcc
@@ -0,0 +1,230 @@
+# makefile for libpng on HP-UX using GCC with the HP ANSI/C linker.
+# Copyright (C) 2002, 2006-2008, 2010-2011 Glenn Randers-Pehrson
+# Copyright (C) 2001, Laurent faillie
+# Copyright (C) 1998, 1999 Greg Roelofs
+# Copyright (C) 1996, 1997 Andreas Dilger
+#
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+# Library name:
+LIBNAME = libpng15
+PNGMAJ = 15
+# Shared library names:
+LIBSO=$(LIBNAME).sl
+LIBSOMAJ=$(LIBNAME).sl.$(PNGMAJ)
+LIBSOREL=$(LIBSOMAJ).$(RELEASE)
+OLDSO=libpng.sl
+# Utilities:
+CC=gcc
+LD=ld
+AR_RC=ar rc
+MKDIR_P=mkdir -p
+LN_SF=ln -sf
+RANLIB=ranlib
+RM_F=/bin/rm -f
+# where "make install" puts libpng.a, $(OLDSO)*, png.h, pngconf.h
+# and pnglibconf.h
+prefix=/usr/local
+exec_prefix=$(prefix)
+# Where the zlib library and include files are located
+ZLIBLIB=/opt/zlib/lib
+ZLIBINC=/opt/zlib/include
+# Note that if you plan to build a libpng shared library, zlib must also
+# be a shared library, which zlib's configure does not do.  After running
+# zlib's configure, edit the appropriate lines of makefile to read:
+#   CFLAGS=-O1 -DHAVE_UNISTD -DUSE_MAP -fPIC \
+#   LDSHARED=ld -b
+#   SHAREDLIB=libz.sl
+ALIGN=
+# for i386:
+#ALIGN=-malign-loops=2 -malign-functions=2
+WARNMORE=-Wwrite-strings -Wpointer-arith -Wshadow \
+        -Wmissing-declarations -Wtraditional -Wcast-align \
+        -Wstrict-prototypes -Wmissing-prototypes #-Wconversion
+# for pgcc version 2.95.1, -O3 is buggy; don't use it.
+CFLAGS=-I$(ZLIBINC) -W -Wall -O3 -funroll-loops -DPNG_NO_MMX_CODE \
+        $(ALIGN) # $(WARNMORE) -g -DPNG_DEBUG=5
+#LDFLAGS=-L. -Wl,-rpath,. -L$(ZLIBLIB) -Wl,-rpath,$(ZLIBLIB) -lpng15 -lz -lm
+LDFLAGS=-L. -L$(ZLIBLIB) -lpng15 -lz -lm
+INCPATH=$(prefix)/include
+LIBPATH=$(exec_prefix)/lib
+MANPATH=$(prefix)/man
+BINPATH=$(exec_prefix)/bin
+# override DESTDIR= on the make install command line to easily support
+# installing into a temporary location.  Example:
+#
+#    make install DESTDIR=/tmp/build/libpng
+#
+# If you're going to install into a temporary location
+# via DESTDIR, $(DESTDIR)$(prefix) must already exist before
+# you execute make install.
+DESTDIR=
+DB=$(DESTDIR)$(BINPATH)
+DI=$(DESTDIR)$(INCPATH)
+DL=$(DESTDIR)$(LIBPATH)
+DM=$(DESTDIR)$(MANPATH)
+OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
+        pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
+        pngwtran.o pngmem.o pngerror.o pngpread.o
+OBJSDLL = $(OBJS:.o=.pic.o)
+.SUFFIXES:      .c .o .pic.o
+.c.pic.o:
+        $(CC) -c $(CFLAGS) -fPIC -o $@ $*.c
+all: libpng.a $(LIBSO) pngtest libpng.pc libpng-config
+libpng.a: $(OBJS)
+        $(AR_RC) $@ $(OBJS)
+        $(RANLIB) $@
+libpng.pc:
+        cat scripts/libpng.pc.in | sed -e s!@prefix@!$(prefix)! \
+        -e s!@exec_prefix@!$(exec_prefix)! \
+        -e s!@libdir@!$(LIBPATH)! \
+        -e s!@includedir@!$(INCPATH)! \
+        -e s!-lpng15!-lpng15\ -lz\ -lm! > libpng.pc
+libpng-config:
+        ( cat scripts/libpng-config-head.in; \
+        echo prefix=\"$(prefix)\"; \
+        echo I_opts=\"-I$(INCPATH)/$(LIBNAME)\"; \
+        echo libs=\"-lpng15 -lz -lm\"; \
+        cat scripts/libpng-config-body.in ) > libpng-config
+        chmod +x libpng-config
+$(LIBSO): $(LIBSOMAJ)
+        $(LN_SF) $(LIBSOMAJ) $(LIBSO)
+$(LIBSOMAJ): $(OBJSDLL)
+        $(LD) -b +s \
+        +h $(LIBSOMAJ) -o $(LIBSOMAJ) $(OBJSDLL)
+pngtest: pngtest.o $(LIBSO)
+        $(CC) -o pngtest $(CFLAGS) pngtest.o $(LDFLAGS)
+test: pngtest
+        ./pngtest
+install-headers: png.h pngconf.h pnglibconf.h
+        -@if [ ! -d $(DI) ]; then $(MKDIR_P) $(DI); fi
+        -@if [ ! -d $(DI)/$(LIBNAME) ]; then $(MKDIR_P) $(DI)/$(LIBNAME); fi
+        cp png.h pngconf.h pnglibconf.h $(DI)/$(LIBNAME)
+        chmod 644 $(DI)/$(LIBNAME)/png.h $(DI)/$(LIBNAME)/pngconf.h $(DI)/$(LIBNAME)/pnglibconf.h
+        -@$(RM_F) $(DI)/png.h $(DI)/pngconf.h $(DI)/pnglibconf.h
+        -@$(RM_F) $(DI)/libpng
+        (cd $(DI); $(LN_SF) $(LIBNAME) libpng; $(LN_SF) $(LIBNAME)/* .)
+install-static: install-headers libpng.a
+        -@if [ ! -d $(DL) ]; then $(MKDIR_P) $(DL); fi
+        cp libpng.a $(DL)/$(LIBNAME).a
+        chmod 644 $(DL)/$(LIBNAME).a
+        -@$(RM_F) $(DL)/libpng.a
+        (cd $(DL); $(LN_SF) $(LIBNAME).a libpng.a)
+install-shared: install-headers $(LIBSOMAJ) libpng.pc
+        -@if [ ! -d $(DL) ]; then $(MKDIR_P) $(DL); fi
+        -@$(RM_F) $(DL)/$(LIBSO)
+        -@$(RM_F) $(DL)/$(LIBSOREL)
+        -@$(RM_F) $(DL)/$(OLDSO)
+        cp $(LIBSOMAJ) $(DL)/$(LIBSOREL)
+        chmod 755 $(DL)/$(LIBSOREL)
+        (cd $(DL); \
+        $(LN_SF) $(LIBSOREL) $(LIBSO); \
+        $(LN_SF) $(LIBSO) $(OLDSO))
+        -@if [ ! -d $(DL)/pkgconfig ]; then $(MKDIR_P) $(DL)/pkgconfig; fi
+        -@$(RM_F) $(DL)/pkgconfig/$(LIBNAME).pc
+        -@$(RM_F) $(DL)/pkgconfig/libpng.pc
+        cp libpng.pc $(DL)/pkgconfig/$(LIBNAME).pc
+        chmod 644 $(DL)/pkgconfig/$(LIBNAME).pc
+        (cd $(DL)/pkgconfig; $(LN_SF) $(LIBNAME).pc libpng.pc)
+install-man: libpng.3 libpngpf.3 png.5
+        -@if [ ! -d $(DM) ]; then $(MKDIR_P) $(DM); fi
+        -@if [ ! -d $(DM)/man3 ]; then $(MKDIR_P) $(DM)/man3; fi
+        -@$(RM_F) $(DM)/man3/libpng.3
+        -@$(RM_F) $(DM)/man3/libpngpf.3
+        cp libpng.3 $(DM)/man3
+        cp libpngpf.3 $(DM)/man3
+        -@if [ ! -d $(DM)/man5 ]; then $(MKDIR_P) $(DM)/man5; fi
+        -@$(RM_F) $(DM)/man5/png.5
+        cp png.5 $(DM)/man5
+install-config: libpng-config
+        -@if [ ! -d $(DB) ]; then $(MKDIR_P) $(DB); fi
+        -@$(RM_F) $(DB)/libpng-config
+        -@$(RM_F) $(DB)/$(LIBNAME)-config
+        cp libpng-config $(DB)/$(LIBNAME)-config
+        chmod 755 $(DB)/$(LIBNAME)-config
+        (cd $(DB); $(LN_SF) $(LIBNAME)-config libpng-config)
+install: install-static install-shared install-man install-config
+# If you installed in $(DESTDIR), test-installed won't work until you
+# move the library to its final location.  Use test-dd to test it
+# before then.
+test-dd:
+        echo
+        echo Testing installed dynamic shared library in $(DL).
+        $(CC) -I$(DI) -I$(ZLIBINC) \
+           `$(BINPATH)/$(LIBNAME)-config --cflags` pngtest.c \
+           -L$(DL) -L$(ZLIBLIB) -Wl,-rpath,$(DL) -Wl,-rpath,$(ZLIBLIB) \
+           -o pngtestd `$(BINPATH)/$(LIBNAME)-config --ldflags`
+        ./pngtestd pngtest.png
+test-installed:
+        echo
+        echo Testing installed dynamic shared library.
+        $(CC) -I$(ZLIBINC) \
+           `$(BINPATH)/$(LIBNAME)-config --cflags` pngtest.c \
+           -L$(ZLIBLIB) -Wl,-rpath,$(ZLIBLIB) \
+           -o pngtesti `$(BINPATH)/$(LIBNAME)-config --ldflags`
+        ./pngtesti pngtest.png
+clean:
+        $(RM_F) *.o libpng.a pngtest pngtesti pngout.png \
+        libpng-config $(LIBSO) $(LIBSOMAJ)* \
+        libpng.pc pnglibconf.h
+DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
+writelock:
+        chmod a-w *.[ch35] $(DOCS) scripts/*
+# DO NOT DELETE THIS LINE -- make depend depends on it.
+png.o png.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngerror.o pngerror.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrio.o pngrio.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwio.o pngwio.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngmem.o pngmem.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngset.o pngset.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngget.o pngget.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngread.o pngread.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrtran.o pngrtran.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrutil.o pngrutil.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtrans.o pngtrans.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwrite.o pngwrite.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwtran.o pngwtran.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwutil.o pngwutil.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngpread.o pngpread.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtest.o: png.h pngconf.h pnglibconf.h
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.hpux b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.hpux
new file mode 100644
index 0000000..fd3a20d
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.hpux
@@ -0,0 +1,221 @@
+# makefile for libpng, HPUX (10.20 and 11.00) using the ANSI/C product.
+# Copyright (C) 1999-2002, 2006, 2010-2011 Glenn Randers-Pehrson
+# Copyright (C) 1995 Guy Eric Schalnat, Group 42
+# contributed by Jim Rice and updated by Chris Schleicher, Hewlett Packard
+#
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+# Where the zlib library and include files are located
+ZLIBLIB=/opt/zlib/lib
+ZLIBINC=/opt/zlib/include
+# Note that if you plan to build a libpng shared library, zlib must also
+# be a shared library, which zlib's configure does not do.  After running
+# zlib's configure, edit the appropriate lines of makefile to read:
+#   CFLAGS=-O1 -DHAVE_UNISTD -DUSE_MAP -fPIC \
+#   LDSHARED=ld -b
+#   SHAREDLIB=libz.sl
+# Library name:
+LIBNAME = libpng15
+PNGMAJ = 15
+# Shared library names:
+LIBSO=$(LIBNAME).sl
+LIBSOMAJ=$(LIBNAME).sl.$(PNGMAJ)
+LIBSOREL=$(LIBSOMAJ).$(RELEASE)
+OLDSO=libpng.sl
+# Utilities:
+AR_RC=ar rc
+CC=cc
+MKDIR_P=mkdir -p
+LN_SF=ln -sf
+RANLIB=ranlib
+RM_F=/bin/rm -f
+# where make install puts libpng.a, libpng15.sl, and png.h
+prefix=/opt/libpng
+exec_prefix=$(prefix)
+INCPATH=$(prefix)/include
+LIBPATH=$(exec_prefix)/lib
+MANPATH=$(prefix)/man
+BINPATH=$(exec_prefix)/bin
+CFLAGS=-I$(ZLIBINC) -O -Ae +DA1.1 +DS2.0
+# Caution: be sure you have built zlib with the same CFLAGS.
+CCFLAGS=-I$(ZLIBINC) -O -Ae +DA1.1 +DS2.0
+LDFLAGS=-L. -L$(ZLIBLIB) -lpng -lz -lm
+# override DESTDIR= on the make install command line to easily support
+# installing into a temporary location.  Example:
+#
+#    make install DESTDIR=/tmp/build/libpng
+#
+# If you're going to install into a temporary location
+# via DESTDIR, $(DESTDIR)$(prefix) must already exist before
+# you execute make install.
+DESTDIR=
+DB=$(DESTDIR)$(BINPATH)
+DI=$(DESTDIR)$(INCPATH)
+DL=$(DESTDIR)$(LIBPATH)
+DM=$(DESTDIR)$(MANPATH)
+OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
+        pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
+        pngwtran.o pngmem.o pngerror.o pngpread.o
+OBJSDLL = $(OBJS:.o=.pic.o)
+.SUFFIXES:      .c .o .pic.o
+.c.pic.o:
+        $(CC) -c $(CFLAGS) +z -o $@ $*.c
+all: libpng.a $(LIBSO) pngtest libpng.pc libpng-config
+# see scripts/pnglibconf.mak for more options
+pnglibconf.h: scripts/pnglibconf.h.prebuilt
+        cp scripts/pnglibconf.h.prebuilt $@
+libpng.a: $(OBJS)
+        $(AR_RC) $@ $(OBJS)
+        $(RANLIB) $@
+libpng.pc:
+        cat scripts/libpng.pc.in | sed -e s!@prefix@!$(prefix)! \
+        -e s!@exec_prefix@!$(exec_prefix)! \
+        -e s!@libdir@!$(LIBPATH)! \
+        -e s!@includedir@!$(INCPATH)! \
+        -e s!-lpng15!-lpng15\ -lz\ -lm! > libpng.pc
+libpng-config:
+        ( cat scripts/libpng-config-head.in; \
+        echo prefix=\"$(prefix)\"; \
+        echo I_opts=\"-I$(INCPATH)/$(LIBNAME)\"; \
+        echo ccopts=\"-Ae +DA1.1 +DS2.0\"; \
+        echo L_opts=\"-L$(LIBPATH)\"; \
+        echo libs=\"-lpng15 -lz -lm\"; \
+        cat scripts/libpng-config-body.in ) > libpng-config
+        chmod +x libpng-config
+$(LIBSO): $(LIBSOMAJ)
+        $(LN_SF) $(LIBSOMAJ) $(LIBSO)
+$(LIBSOMAJ): $(OBJSDLL)
+        $(LD) -b +s \
+        +h $(LIBSOMAJ) -o $(LIBSOMAJ) $(OBJSDLL)
+pngtest: pngtest.o libpng.a
+        $(CC) -o pngtest $(CCFLAGS) pngtest.o $(LDFLAGS)
+test: pngtest
+        ./pngtest
+install-headers: png.h pngconf.h pnglibconf.h
+        -@if [ ! -d $(DI) ]; then $(MKDIR_P) $(DI); fi
+        -@if [ ! -d $(DI)/$(LIBNAME) ]; then $(MKDIR_P) $(DI)/$(LIBNAME); fi
+        cp png.h pngconf.h pnglibconf.h $(DI)/$(LIBNAME)
+        chmod 644 $(DI)/$(LIBNAME)/png.h $(DI)/$(LIBNAME)/pngconf.h $(DI)/$(LIBNAME)/pnglibconf.h
+        -@$(RM_F) $(DI)/png.h $(DI)/pngconf.h $(DI)/pnglibconf.h
+        -@$(RM_F) $(DI)/libpng
+        (cd $(DI); $(LN_SF) $(LIBNAME) libpng; $(LN_SF) $(LIBNAME)/* .)
+install-static: install-headers libpng.a
+        -@if [ ! -d $(DL) ]; then $(MKDIR_P) $(DL); fi
+        cp libpng.a $(DL)/$(LIBNAME).a
+        chmod 644 $(DL)/$(LIBNAME).a
+        -@$(RM_F) $(DL)/libpng.a
+        (cd $(DL); $(LN_SF) $(LIBNAME).a libpng.a)
+install-shared: install-headers $(LIBSOMAJ) libpng.pc
+        -@if [ ! -d $(DL) ]; then $(MKDIR_P) $(DL); fi
+        -@$(RM_F) $(DL)/$(LIBSO)
+        -@$(RM_F) $(DL)/$(LIBSOREL)
+        -@$(RM_F) $(DL)/$(OLDSO)
+        cp $(LIBSOMAJ) $(DL)/$(LIBSOREL)
+        chmod 755 $(DL)/$(LIBSOREL)
+        (cd $(DL); \
+        $(LN_SF) $(LIBSOREL) $(LIBSO); \
+        $(LN_SF) $(LIBSO) $(OLDSO))
+        -@if [ ! -d $(DL)/pkgconfig ]; then $(MKDIR_P) $(DL)/pkgconfig; fi
+        -@$(RM_F) $(DL)/pkgconfig/$(LIBNAME).pc
+        -@$(RM_F) $(DL)/pkgconfig/libpng.pc
+        cp libpng.pc $(DL)/pkgconfig/$(LIBNAME).pc
+        chmod 644 $(DL)/pkgconfig/$(LIBNAME).pc
+        (cd $(DL)/pkgconfig; $(LN_SF) $(LIBNAME).pc libpng.pc)
+install-man: libpng.3 libpngpf.3 png.5
+        -@if [ ! -d $(DM) ]; then $(MKDIR_P) $(DM); fi
+        -@if [ ! -d $(DM)/man3 ]; then $(MKDIR_P) $(DM)/man3; fi
+        -@$(RM_F) $(DM)/man3/libpng.3
+        -@$(RM_F) $(DM)/man3/libpngpf.3
+        cp libpng.3 $(DM)/man3
+        cp libpngpf.3 $(DM)/man3
+        -@if [ ! -d $(DM)/man5 ]; then $(MKDIR_P) $(DM)/man5; fi
+        -@$(RM_F) $(DM)/man5/png.5
+        cp png.5 $(DM)/man5
+install-config: libpng-config
+        -@if [ ! -d $(DB) ]; then $(MKDIR_P) $(DB); fi
+        -@$(RM_F) $(DB)/libpng-config
+        -@$(RM_F) $(DB)/$(LIBNAME)-config
+        cp libpng-config $(DB)/$(LIBNAME)-config
+        chmod 755 $(DB)/$(LIBNAME)-config
+        (cd $(DB); $(LN_SF) $(LIBNAME)-config libpng-config)
+install: install-static install-shared install-man install-config
+# If you installed in $(DESTDIR), test-installed won't work until you
+# move the library to its final location.  Use test-dd to test it
+# before then.
+test-dd:
+        echo
+        echo Testing installed dynamic shared library in $(DL).
+        $(CC) -I$(DI) -I$(ZLIBINC) $(CCFLAGS) \
+           `$(BINPATH)/$(LIBNAME)-config --cflags` pngtest.c \
+           -L$(DL) -L$(ZLIBLIB) \
+           -o pngtestd `$(BINPATH)/$(LIBNAME)-config --ldflags`
+        ./pngtestd pngtest.png
+test-installed:
+        echo
+        echo Testing installed dynamic shared library.
+        $(CC) $(CCFLAGS) \
+           `$(BINPATH)/$(LIBNAME)-config --cflags` pngtest.c \
+           -L$(ZLIBLIB) \
+           -o pngtesti `$(BINPATH)/$(LIBNAME)-config --ldflags`
+        ./pngtesti pngtest.png
+clean:
+        $(RM_F) *.o libpng.a pngtest pngtesti pngout.png \
+        libpng-config $(LIBSO) $(LIBSOMAJ)* \
+        libpng.pc pnglibconf.h
+DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
+writelock:
+        chmod a-w *.[ch35] $(DOCS) scripts/*
+# DO NOT DELETE THIS LINE -- make depend depends on it.
+png.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngerror.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrio.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwio.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngmem.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngset.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngget.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngread.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrtran.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrutil.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtrans.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwrite.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwtran.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwutil.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngpread.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtest.o: png.h pngconf.h pnglibconf.h
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.ibmc b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.ibmc
new file mode 100644
index 0000000..8c9440a
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.ibmc
@@ -0,0 +1,82 @@
+# Makefile for libpng (static)
+# IBM C version 3.x for Win32 and OS/2
+# Copyright (C) 2006 Glenn Randers-Pehrson
+# Copyright (C) 2000 Cosmin Truta
+#
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+#
+# Notes:
+#   Derived from makefile.std
+#   All modules are compiled in C mode
+#   Tested under Win32, expected to work under OS/2
+#   Can be easily adapted for IBM VisualAge/C++ for AIX
+# Location of the zlib library and include files
+ZLIBINC = ../zlib
+ZLIBLIB = ../zlib
+# Compiler, linker, lib and other tools
+CC = icc
+LD = ilink
+AR = ilib
+RM = del
+CFLAGS = -I$(ZLIBINC) -Mc -O2 -W3
+LDFLAGS =
+# File extensions
+O=.obj
+A=.lib
+E=.exe
+# Variables
+OBJS = png$(O) pngerror$(O) pngget$(O) pngmem$(O) pngpread$(O) \
+        pngread$(O) pngrio$(O) pngrtran$(O) pngrutil$(O) pngset$(O) \
+        pngtrans$(O) pngwio$(O) pngwrite$(O) pngwtran$(O) pngwutil$(O)
+LIBS = libpng$(A) $(ZLIBLIB)/zlib$(A)
+# Targets
+all: libpng$(A) pngtest$(E)
+# see scripts/pnglibconf.mak for more options
+pnglibconf.h: scripts/pnglibconf.h.prebuilt
+        cp scripts/pnglibconf.h.prebuilt $@
+libpng$(A): $(OBJS)
+        $(AR) -out:$@ $(OBJS)
+test: pngtest$(E)
+        pngtest$(E)
+pngtest: pngtest$(E)
+pngtest$(E): pngtest$(O) libpng$(A)
+        $(LD) $(LDFLAGS) pngtest$(O) $(LIBS)
+clean:
+        $(RM) *$(O)
+        $(RM) libpng$(A)
+        $(RM) pnglibconf.h
+        $(RM) pngtest$(E)
+        $(RM) pngout.png
+png$(O):      png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngerror$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngget$(O):   png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngmem$(O):   png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngpread$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngread$(O):  png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrio$(O):   png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrtran$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrutil$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngset$(O):   png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtrans$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwio$(O):   png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwrite$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwtran$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwutil$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtest$(O):  png.h pngconf.h pnglibconf.h
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.intel b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.intel
new file mode 100644
index 0000000..4231078
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.intel
@@ -0,0 +1,110 @@
+# Makefile for libpng
+# Microsoft Visual C++ with Intel C/C++ Compiler 4.0 and later
+# Copyright (C) 2006 Glenn Randers-Pehrson
+# Copyright (C) 2000, Pawel Mrochen, based on makefile.msc which is
+# copyright 1995 Guy Eric Schalnat, Group 42, Inc.
+#
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+#
+# To use, do "nmake /f scripts\makefile.intel"
+#
+# ------------------- Intel C/C++ Compiler 4.0 and later -------------------
+# Where the zlib library and include files are located
+ZLIBLIB=..\zlib
+ZLIBINC=..\zlib
+# Target CPU
+CPU=6           # Pentium II
+#CPU=5          # Pentium
+# Calling convention
+CALLING=r       # __fastcall
+#CALLING=z      # __stdcall
+#CALLING=d      # __cdecl
+# Uncomment next to put error messages in a file
+#ERRFILE=>>pngerrs
+# --------------------------------------------------------------------------
+CC=icl -c
+CFLAGS=-O2 -G$(CPU)$(CALLING) -Qip -Qunroll4 -I$(ZLIBINC) -nologo
+LD=link
+LDFLAGS=/SUBSYSTEM:CONSOLE /NOLOGO
+O=.obj
+OBJS=png$(O) pngset$(O) pngget$(O) pngrutil$(O) pngtrans$(O) pngwutil$(O) \
+pngmem$(O) pngpread$(O) pngread$(O) pngerror$(O) pngwrite$(O) \
+pngrtran$(O) pngwtran$(O) pngrio$(O) pngwio$(O)
+all: test
+# see scripts/pnglibconf.mak for more options
+pnglibconf.h: scripts/pnglibconf.h.prebuilt
+        cp scripts/pnglibconf.h.prebuilt $@
+png$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) $(CFLAGS) $*.c $(ERRFILE)
+pngset$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) $(CFLAGS) $*.c $(ERRFILE)
+pngget$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) $(CFLAGS) $*.c $(ERRFILE)
+pngread$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) $(CFLAGS) $*.c $(ERRFILE)
+pngpread$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) $(CFLAGS) $*.c $(ERRFILE)
+pngrtran$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) $(CFLAGS) $*.c $(ERRFILE)
+pngrutil$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) $(CFLAGS) $*.c $(ERRFILE)
+pngerror$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) $(CFLAGS) $*.c $(ERRFILE)
+pngmem$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) $(CFLAGS) $*.c $(ERRFILE)
+pngrio$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) $(CFLAGS) $*.c $(ERRFILE)
+pngwio$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) $(CFLAGS) $*.c $(ERRFILE)
+pngtrans$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) $(CFLAGS) $*.c $(ERRFILE)
+pngwrite$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) $(CFLAGS) $*.c $(ERRFILE)
+pngwtran$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) $(CFLAGS) $*.c $(ERRFILE)
+pngwutil$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) $(CFLAGS) $*.c $(ERRFILE)
+libpng.lib: $(OBJS)
+        if exist libpng.lib del libpng.lib
+        lib /NOLOGO /OUT:libpng.lib $(OBJS)
+pngtest.exe: pngtest.obj libpng.lib
+        $(LD) $(LDFLAGS) /OUT:pngtest.exe pngtest.obj libpng.lib $(ZLIBLIB)\zlib.lib
+pngtest$(O): png.h pngconf.h pnglibconf.h
+        $(CC) $(CFLAGS) $*.c $(ERRFILE)
+test: pngtest.exe
+        pngtest.exe
+# End of makefile for libpng
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.knr b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.knr
new file mode 100644
index 0000000..912c542
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.knr
@@ -0,0 +1,109 @@
+# makefile for libpng
+# Copyright (C) 2002, 2006, 2009 Glenn Randers-Pehrson
+# Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
+#
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+#
+# This makefile requires the file ansi2knr.c, which you can get
+# from the Ghostscript ftp site at ftp://ftp.cs.wisc.edu/ghost/
+# If you have libjpeg, you probably already have ansi2knr.c in the jpeg
+# source distribution.
+# where make install puts libpng.a and png.h
+prefix=/usr/local
+INCPATH=$(prefix)/include
+LIBPATH=$(prefix)/lib
+# override DESTDIR= on the make install command line to easily support
+# installing into a temporary location.  Example:
+#
+#    make install DESTDIR=/tmp/build/libpng
+#
+# If you're going to install into a temporary location
+# via DESTDIR, $(DESTDIR)$(prefix) must already exist before
+# you execute make install.
+DESTDIR=
+CC=cc
+CFLAGS=-I../zlib -O
+LDFLAGS=-L. -L../zlib/ -lpng -lz -lm
+# flags for ansi2knr
+ANSI2KNRFLAGS=
+RANLIB=ranlib
+#RANLIB=echo
+OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
+        pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
+        pngwtran.o pngmem.o pngerror.o pngpread.o
+all: ansi2knr libpng.a pngtest
+# see scripts/pnglibconf.mak for more options
+pnglibconf.h: scripts/pnglibconf.h.prebuilt
+        cp scripts/pnglibconf.h.prebuilt $@
+# general rule to allow ansi2knr to work
+.c.o:
+        ./ansi2knr $*.c T$*.c
+        $(CC) $(CFLAGS) -c T$*.c
+        rm -f T$*.c $*.o
+        mv T$*.o $*.o
+ansi2knr: ansi2knr.c
+        $(CC) $(CFLAGS) $(ANSI2KNRFLAGS) -o ansi2knr ansi2knr.c
+libpng.a: ansi2knr $(OBJS)
+        ar rc $@  $(OBJS)
+        $(RANLIB) $@
+pngtest: pngtest.o libpng.a
+        $(CC) -o pngtest $(CFLAGS) pngtest.o $(LDFLAGS)
+test: pngtest
+        ./pngtest
+install: libpng.a png.h pngconf.h pnglibconf.h
+        -@mkdir $(DESTDIR)$(INCPATH)
+        -@mkdir $(DESTDIR)$(INCPATH)/libpng
+        -@mkdir $(DESTDIR)$(LIBPATH)
+        -@rm -f $(DESTDIR)$(INCPATH)/png.h
+        -@rm -f $(DESTDIR)$(INCPATH)/pngconf.h
+        cp png.h $(DESTDIR)$(INCPATH)/libpng
+        cp pngconf.h $(DESTDIR)$(INCPATH)/libpng
+        cp pnglibconf.h $(DESTDIR)$(INCPATH)/libpng
+        chmod 644 $(DESTDIR)$(INCPATH)/libpng/png.h
+        chmod 644 $(DESTDIR)$(INCPATH)/libpng/pngconf.h
+        chmod 644 $(DESTDIR)$(INCPATH)/libpng/pnglibconf.h
+        (cd $(DESTDIR)$(INCPATH); ln -f -s libpng/* .)
+        cp libpng.a $(DESTDIR)$(LIBPATH)
+        chmod 644 $(DESTDIR)$(LIBPATH)/libpng.a
+clean:
+        rm -f *.o libpng.a pngtest pngout.png ansi2knr pnglibconf.h
+DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
+writelock:
+        chmod a-w *.[ch35] $(DOCS) scripts/*
+# DO NOT DELETE THIS LINE -- make depend depends on it.
+png.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngerror.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrio.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwio.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngmem.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngset.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngget.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngread.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngpread.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrtran.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrutil.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtrans.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwrite.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwtran.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwutil.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtest.o: png.h pngconf.h pnglibconf.h
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.linux b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.linux
new file mode 100644
index 0000000..95680f6
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.linux
@@ -0,0 +1,239 @@
+# makefile for libpng.a and libpng15.so on Linux ELF with gcc
+# Copyright (C) 1998, 1999, 2002, 2006, 2008, 2010-2011 Greg Roelofs and
+# Glenn Randers-Pehrson
+# Copyright (C) 1996, 1997 Andreas Dilger
+#
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+# Library name:
+LIBNAME = libpng15
+PNGMAJ = 15
+RELEASE = 9
+# Shared library names:
+LIBSO=$(LIBNAME).so
+LIBSOMAJ=$(LIBNAME).so.$(PNGMAJ)
+LIBSOREL=$(LIBSOMAJ).$(RELEASE)
+OLDSO=libpng.so
+# Utilities:
+AR_RC=ar rc
+CC=gcc
+MKDIR_P=mkdir -p
+LN_SF=ln -sf
+RANLIB=ranlib
+RM_F=/bin/rm -f
+# where "make install" puts libpng15.a, libpng15.so*,
+# libpng15/png.h, libpng15/pngconf.h, and libpng15/pnglibconf.h
+# Prefix must be a full pathname.
+prefix=/usr/local
+exec_prefix=$(prefix)
+# Where the zlib library and include files are located.
+#ZLIBLIB=/usr/local/lib
+#ZLIBINC=/usr/local/include
+ZLIBLIB=../zlib
+ZLIBINC=../zlib
+ALIGN=
+# for i386:
+#ALIGN=-malign-loops=2 -malign-functions=2
+WARNMORE=-Wwrite-strings -Wpointer-arith -Wshadow \
+        -Wmissing-declarations -Wtraditional -Wcast-align \
+        -Wstrict-prototypes -Wmissing-prototypes #-Wconversion
+# for pgcc version 2.95.1, -O3 is buggy; don't use it.
+CFLAGS=-I$(ZLIBINC) -W -Wall -O3 -funroll-loops \
+        $(ALIGN) # $(WARNMORE) -g -DPNG_DEBUG=5
+LDFLAGS=-L. -Wl,-rpath,. -L$(ZLIBLIB) -Wl,-rpath,$(ZLIBLIB) -lpng15 -lz -lm
+LDFLAGS_A=-L$(ZLIBLIB) -Wl,-rpath,$(ZLIBLIB) libpng.a -lz -lm
+INCPATH=$(prefix)/include
+LIBPATH=$(exec_prefix)/lib
+MANPATH=$(prefix)/man
+BINPATH=$(exec_prefix)/bin
+# override DESTDIR= on the make install command line to easily support
+# installing into a temporary location.  Example:
+#
+#    make install DESTDIR=/tmp/build/libpng
+#
+# If you're going to install into a temporary location
+# via DESTDIR, $(DESTDIR)$(prefix) must already exist before
+# you execute make install.
+DESTDIR=
+DB=$(DESTDIR)$(BINPATH)
+DI=$(DESTDIR)$(INCPATH)
+DL=$(DESTDIR)$(LIBPATH)
+DM=$(DESTDIR)$(MANPATH)
+OBJS =  png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
+        pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
+        pngwtran.o pngmem.o pngerror.o pngpread.o
+OBJSDLL = $(OBJS:.o=.pic.o)
+.SUFFIXES:      .c .o .pic.o
+.c.pic.o:
+        $(CC) -c $(CFLAGS) -fPIC -o $@ $*.c
+all: libpng.a $(LIBSO) pngtest pngtest-static libpng.pc libpng-config
+# see scripts/pnglibconf.mak for more options
+pnglibconf.h: scripts/pnglibconf.h.prebuilt
+        cp scripts/pnglibconf.h.prebuilt $@
+libpng.a: $(OBJS)
+        $(AR_RC) $@ $(OBJS)
+        $(RANLIB) $@
+libpng.pc:
+        cat scripts/libpng.pc.in | sed -e s!@prefix@!$(prefix)! \
+        -e s!@exec_prefix@!$(exec_prefix)! \
+        -e s!@libdir@!$(LIBPATH)! \
+        -e s!@includedir@!$(INCPATH)! \
+        -e s!-lpng15!-lpng15\ -lz\ -lm! > libpng.pc
+libpng-config:
+        ( cat scripts/libpng-config-head.in; \
+        echo prefix=\"$(prefix)\"; \
+        echo I_opts=\"-I$(INCPATH)/$(LIBNAME)\"; \
+        echo L_opts=\"-L$(LIBPATH)\"; \
+        echo R_opts=\"-Wl,-rpath,$(LIBPATH)\"; \
+        echo libs=\"-lpng15 -lz -lm\"; \
+        cat scripts/libpng-config-body.in ) > libpng-config
+        chmod +x libpng-config
+$(LIBSO): $(LIBSOMAJ)
+        $(LN_SF) $(LIBSOMAJ) $(LIBSO)
+$(LIBSOMAJ): $(OBJSDLL)
+        $(CC) -shared -Wl,-soname,$(LIBSOMAJ) -o $(LIBSOMAJ) $(OBJSDLL)
+pngtest: pngtest.o $(LIBSO)
+        $(CC) -o pngtest $(CFLAGS) pngtest.o $(LDFLAGS)
+pngtest-static: pngtest.o libpng.a
+        $(CC) -o pngtest-static $(CFLAGS) pngtest.o $(LDFLAGS_A)
+test: pngtest pngtest-static
+        @echo ""
+        @echo "   Running pngtest dynamically linked with $(LIBSO):"
+        @echo ""
+        ./pngtest
+        @echo ""
+        @echo "   Running pngtest statically linked with libpng.a:"
+        @echo ""
+        ./pngtest-static
+install-headers: png.h pngconf.h pnglibconf.h
+        -@if [ ! -d $(DI) ]; then $(MKDIR_P) $(DI); fi
+        -@if [ ! -d $(DI)/$(LIBNAME) ]; then $(MKDIR_P) $(DI)/$(LIBNAME); fi
+        cp png.h pngconf.h pnglibconf.h $(DI)/$(LIBNAME)
+        chmod 644 $(DI)/$(LIBNAME)/png.h $(DI)/$(LIBNAME)/pngconf.h $(DI)/$(LIBNAME)/pnglibconf.h
+        -@$(RM_F) $(DI)/png.h $(DI)/pngconf.h $(DI)/pnglibconf.h
+        -@$(RM_F) $(DI)/libpng
+        (cd $(DI); $(LN_SF) $(LIBNAME) libpng; $(LN_SF) $(LIBNAME)/* .)
+install-static: install-headers libpng.a
+        -@if [ ! -d $(DL) ]; then $(MKDIR_P) $(DL); fi
+        cp libpng.a $(DL)/$(LIBNAME).a
+        chmod 644 $(DL)/$(LIBNAME).a
+        -@$(RM_F) $(DL)/libpng.a
+        (cd $(DL); $(LN_SF) $(LIBNAME).a libpng.a)
+install-shared: install-headers $(LIBSOMAJ) libpng.pc
+        -@if [ ! -d $(DL) ]; then $(MKDIR_P) $(DL); fi
+        -@$(RM_F) $(DL)/$(LIBSO)
+        -@$(RM_F) $(DL)/$(LIBSOREL)
+        -@$(RM_F) $(DL)/$(OLDSO)
+        cp $(LIBSOMAJ) $(DL)/$(LIBSOREL)
+        chmod 755 $(DL)/$(LIBSOREL)
+        (cd $(DL); \
+        $(LN_SF) $(LIBSOREL) $(LIBSO); \
+        $(LN_SF) $(LIBSO) $(OLDSO))
+        -@if [ ! -d $(DL)/pkgconfig ]; then $(MKDIR_P) $(DL)/pkgconfig; fi
+        -@$(RM_F) $(DL)/pkgconfig/$(LIBNAME).pc
+        -@$(RM_F) $(DL)/pkgconfig/libpng.pc
+        cp libpng.pc $(DL)/pkgconfig/$(LIBNAME).pc
+        chmod 644 $(DL)/pkgconfig/$(LIBNAME).pc
+        (cd $(DL)/pkgconfig; $(LN_SF) $(LIBNAME).pc libpng.pc)
+install-man: libpng.3 libpngpf.3 png.5
+        -@if [ ! -d $(DM) ]; then $(MKDIR_P) $(DM); fi
+        -@if [ ! -d $(DM)/man3 ]; then $(MKDIR_P) $(DM)/man3; fi
+        -@$(RM_F) $(DM)/man3/libpng.3
+        -@$(RM_F) $(DM)/man3/libpngpf.3
+        cp libpng.3 $(DM)/man3
+        cp libpngpf.3 $(DM)/man3
+        -@if [ ! -d $(DM)/man5 ]; then $(MKDIR_P) $(DM)/man5; fi
+        -@$(RM_F) $(DM)/man5/png.5
+        cp png.5 $(DM)/man5
+install-config: libpng-config
+        -@if [ ! -d $(DB) ]; then $(MKDIR_P) $(DB); fi
+        -@$(RM_F) $(DB)/libpng-config
+        -@$(RM_F) $(DB)/$(LIBNAME)-config
+        cp libpng-config $(DB)/$(LIBNAME)-config
+        chmod 755 $(DB)/$(LIBNAME)-config
+        (cd $(DB); $(LN_SF) $(LIBNAME)-config libpng-config)
+install: install-static install-shared install-man install-config
+# If you installed in $(DESTDIR), test-installed won't work until you
+# move the library to its final location.  Use test-dd to test it
+# before then.
+test-dd:
+        echo
+        echo Testing installed dynamic shared library in $(DL).
+        $(CC) -I$(DI) -I$(ZLIBINC) \
+           `$(BINPATH)/$(LIBNAME)-config --cflags` pngtest.c \
+           -L$(DL) -L$(ZLIBLIB) -Wl, -rpath,$(DL) -Wl,-rpath,$(ZLIBLIB) \
+           -o pngtestd `$(BINPATH)/$(LIBNAME)-config --ldflags`
+        ./pngtestd pngtest.png
+test-installed:
+        $(CC) -I$(ZLIBINC) \
+           `$(BINPATH)/$(LIBNAME)-config --cflags` pngtest.c \
+           -L$(ZLIBLIB) -Wl,-rpath,$(ZLIBLIB) \
+           -o pngtesti `$(BINPATH)/$(LIBNAME)-config --ldflags`
+        ./pngtesti pngtest.png
+clean:
+        $(RM_F) *.o libpng.a pngtest pngout.png libpng-config \
+        $(LIBSO) $(LIBSOMAJ)* pngtest-static pngtesti \
+        libpng.pc pnglibconf.h
+DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
+writelock:
+        chmod a-w *.[ch35] $(DOCS) scripts/*
+# DO NOT DELETE THIS LINE -- make depend depends on it.
+png.o png.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngerror.o pngerror.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrio.o pngrio.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwio.o pngwio.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngmem.o pngmem.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngset.o pngset.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngget.o pngget.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngread.o pngread.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrtran.o pngrtran.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrutil.o pngrutil.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtrans.o pngtrans.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwrite.o pngwrite.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwtran.o pngwtran.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwutil.o pngwutil.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngpread.o pngpread.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtest.o: png.h pngconf.h
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.mips b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.mips
new file mode 100644
index 0000000..bd254fc
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.mips
@@ -0,0 +1,94 @@
+# makefile for libpng
+# Copyright (C) Glenn Randers-Pehrson
+# Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
+#
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+# where make install puts libpng.a and png.h
+prefix=/usr/local
+INCPATH=$(prefix)/include
+LIBPATH=$(prefix)/lib
+# override DESTDIR= on the make install command line to easily support
+# installing into a temporary location.  Example:
+#
+#    make install DESTDIR=/tmp/build/libpng
+#
+# If you're going to install into a temporary location
+# via DESTDIR, $(DESTDIR)$(prefix) must already exist before
+# you execute make install.
+DESTDIR=
+CC=cc
+CFLAGS=-I../zlib -O -systype sysv -DSYSV -w -Dmips
+#CFLAGS=-O
+LDFLAGS=-L. -L../zlib/ -lpng -lz -lm
+#RANLIB=ranlib
+RANLIB=echo
+OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
+        pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
+        pngwtran.o pngmem.o pngerror.o pngpread.o
+all: libpng.a pngtest
+# see scripts/pnglibconf.mak for more options
+pnglibconf.h: scripts/pnglibconf.h.prebuilt
+        cp scripts/pnglibconf.h.prebuilt $@
+libpng.a: $(OBJS)
+        ar rc $@  $(OBJS)
+        $(RANLIB) $@
+pngtest: pngtest.o libpng.a
+        $(CC) -o pngtest $(CFLAGS) pngtest.o $(LDFLAGS)
+test: pngtest
+        ./pngtest
+install: libpng.a
+        -@mkdir $(DESTDIR)$(INCPATH)
+        -@mkdir $(DESTDIR)$(INCPATH)/libpng
+        -@mkdir $(DESTDIR)$(LIBPATH)
+        -@rm -f $(DESTDIR)$(INCPATH)/png.h
+        -@rm -f $(DESTDIR)$(INCPATH)/pngconf.h
+        -@rm -f $(DESTDIR)$(INCPATH)/pnglibconf.h
+        cp png.h $(DESTDIR)$(INCPATH)/libpng
+        cp pngconf.h $(DESTDIR)$(INCPATH)/libpng
+        cp pnglibconf.h $(DESTDIR)$(INCPATH)/libpng
+        chmod 644 $(DESTDIR)$(INCPATH)/libpng/png.h
+        chmod 644 $(DESTDIR)$(INCPATH)/libpng/pngconf.h
+        chmod 644 $(DESTDIR)$(INCPATH)/libpng/pnglibconf.h
+        (cd $(DESTDIR)$(INCPATH); ln -f -s libpng/* .)
+        cp libpng.a $(DESTDIR)$(LIBPATH)
+        chmod 644 $(DESTDIR)$(LIBPATH)/libpng.a
+clean:
+        rm -f *.o libpng.a pngtest pngout.png pnglibconf.h
+DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
+writelock:
+        chmod a-w *.[ch35] $(DOCS) scripts/*
+# DO NOT DELETE THIS LINE -- make depend depends on it.
+png.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngerror.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrio.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwio.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngmem.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngset.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngget.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngread.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngpread.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrtran.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrutil.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtrans.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwrite.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwtran.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwutil.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtest.o: png.h pngconf.h pnglibconf.h
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.msc b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.msc
new file mode 100644
index 0000000..25adbb4
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.msc
@@ -0,0 +1,95 @@
+# makefile for libpng
+# Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
+# Copyright (C) 2006, 2009 Glenn Randers-Pehrson
+#
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+#
+# Assumes that zlib.lib, zconf.h, and zlib.h have been copied to ..\zlib
+# -------- Microsoft C 5.1 and later, does not use assembler code --------
+MODEL=L
+CFLAGS=-Oait -Gs -nologo -W3 -A$(MODEL) -I..\zlib
+#-Ox generates bad code with MSC 5.1
+CC=cl
+LD=link
+LDFLAGS=/e/st:0x1500/noe
+O=.obj
+#uncomment next to put error messages in a file
+ERRFILE= >> pngerrs
+# variables
+OBJS1 = png$(O) pngset$(O) pngget$(O) pngrutil$(O) pngtrans$(O) pngwutil$(O)
+OBJS2 = pngmem$(O) pngpread$(O) pngread$(O) pngerror$(O) pngwrite$(O)
+OBJS3 = pngrtran$(O) pngwtran$(O) pngrio$(O) pngwio$(O)
+all: libpng.lib
+# see scripts/pnglibconf.mak for more options
+pnglibconf.h: scripts/pnglibconf.h.prebuilt
+        cp scripts/pnglibconf.h.prebuilt $@
+png$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+                  $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+pngset$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+pngget$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+pngread$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+pngpread$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+                  $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+pngrtran$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+pngrutil$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+pngerror$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+pngmem$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+pngrio$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+pngwio$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+pngtrans$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+pngwrite$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+pngwtran$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+pngwutil$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+libpng.lib: $(OBJS1) $(OBJS2) $(OBJS3)
+        del libpng.lib
+        lib libpng $(OBJS1);
+        lib libpng $(OBJS2);
+        lib libpng $(OBJS3);
+pngtest$(O): png.h pngconf.h pnglibconf.h
+        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+pngtest.exe: pngtest.obj libpng.lib
+        $(LD) $(LDFLAGS) pngtest.obj,,,libpng.lib ..\zlib\zlib.lib ;
+test: pngtest.exe
+        pngtest
+# End of makefile for libpng
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.ne12bsd b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.ne12bsd
new file mode 100644
index 0000000..526284f
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.ne12bsd
@@ -0,0 +1,50 @@
+# makefile for libpng for NetBSD for the standard
+# make obj && make depend && make && make test
+# make includes && make install
+# Copyright (C) 2002 Patrick R.L. Welche
+# Copyright (C) 2007, 2009 Glenn Randers-Pehrson
+#
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+# You should also run makefile.netbsd
+LOCALBASE?=/usr/local
+LIBDIR= ${LOCALBASE}/lib
+MANDIR= ${LOCALBASE}/man
+INCSDIR=${LOCALBASE}/include/libpng15
+LIB=    png15
+SHLIB_MAJOR=    0
+SHLIB_MINOR=    1.5.9
+SRCS=   png.c pngset.c pngget.c pngrutil.c pngtrans.c pngwutil.c \
+        pngread.c pngrio.c pngwio.c pngwrite.c pngrtran.c \
+        pngwtran.c pngmem.c pngerror.c pngpread.c
+INCS=   png.h pngconf.h pnglibconf.h
+MAN=    libpng.3 libpngpf.3 png.5
+CPPFLAGS+=-I${.CURDIR}
+# We should be able to do something like this instead of the manual
+# uncommenting, but it core dumps for me at the moment:
+# .if ${MACHINE_ARCH} == "i386"
+#   MKLINT= no
+# .endif
+CLEANFILES+=pngtest.o pngtest pnglibconf.h
+# see scripts/pnglibconf.mak for more options
+pnglibconf.h: scripts/pnglibconf.h.prebuilt
+        cp scripts/pnglibconf.h.prebuilt $@
+pngtest.o:      pngtest.c
+        ${CC} -c ${CPPFLAGS} ${CFLAGS} ${.ALLSRC} -o ${.TARGET}
+pngtest:        pngtest.o libpng.a
+        ${CC} ${LDFLAGS} ${.ALLSRC} -o${.TARGET} -lz -lm
+test:   pngtest
+        cd ${.CURDIR} && ${.OBJDIR}/pngtest
+.include <bsd.lib.mk>
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.netbsd b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.netbsd
new file mode 100644
index 0000000..5dec277
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.netbsd
@@ -0,0 +1,50 @@
+# makefile for libpng for NetBSD for the standard
+# make obj && make depend && make && make test
+# make includes && make install
+# Copyright (C) 2002 Patrick R.L. Welche
+# Copyright (C) 2007-2009 Glenn Randers-Pehrson
+#
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+# You should also run makefile.ne15bsd
+LOCALBASE?=/usr/local
+LIBDIR= ${LOCALBASE}/lib
+MANDIR= ${LOCALBASE}/man
+INCSDIR=${LOCALBASE}/include
+LIB=    png
+SHLIB_MAJOR=    15
+SHLIB_MINOR=    1.5.9
+SRCS=   png.c pngset.c pngget.c pngrutil.c pngtrans.c pngwutil.c \
+        pngread.c pngrio.c pngwio.c pngwrite.c pngrtran.c \
+        pngwtran.c pngmem.c pngerror.c pngpread.c
+INCS=   png.h pngconf.h pnglibconf.h
+MAN=    libpng.3 libpngpf.3 png.5
+CPPFLAGS+=-I${.CURDIR}
+# We should be able to do something like this instead of the manual
+# uncommenting, but it core dumps for me at the moment:
+# .if ${MACHINE_ARCH} == "i386"
+#   MKLINT= no
+# .endif
+CLEANFILES+=pngtest.o pngtest pnglibconf.h
+# see scripts/pnglibconf.mak for more options
+pnglibconf.h: scripts/pnglibconf.h.prebuilt
+        cp scripts/pnglibconf.h.prebuilt $@
+pngtest.o:      pngtest.c
+        ${CC} -c ${CPPFLAGS} ${CFLAGS} ${.ALLSRC} -o ${.TARGET}
+pngtest:        pngtest.o libpng.a
+        ${CC} ${LDFLAGS} ${.ALLSRC} -o${.TARGET} -lz -lm
+test:   pngtest
+        cd ${.CURDIR} && ${.OBJDIR}/pngtest
+.include <bsd.lib.mk>
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.openbsd b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.openbsd
new file mode 100644
index 0000000..c4e7e07
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.openbsd
@@ -0,0 +1,82 @@
+# makefile for libpng
+# Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
+# Copyright (C) 2007-2009 Glenn Randers-Pehrson
+#
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+PREFIX?= /usr/local
+LIBDIR= ${PREFIX}/lib
+MANDIR= ${PREFIX}/man/cat
+SHLIB_MAJOR=    15
+SHLIB_MINOR=    1.5.9
+LIB=    png
+SRCS=   png.c pngerror.c pngget.c pngmem.c pngpread.c \
+        pngread.c pngrio.c pngrtran.c pngrutil.c pngset.c pngtrans.c \
+        pngwio.c pngwrite.c pngwtran.c pngwutil.c
+HDRS=   png.h pngconf.h pnglibconf.h
+CFLAGS+= -W -Wall
+CPPFLAGS+= -I${.CURDIR}
+NOPROFILE= Yes
+CLEANFILES+= pngtest.o pngtest pnglibconf.h
+MAN=    libpng.3 libpngpf.3 png.5
+DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO \
+       libpng-manual.txt
+# see scripts/pnglibconf.mak for more options
+pnglibconf.h: scripts/pnglibconf.h.prebuilt
+        cp scripts/pnglibconf.h.prebuilt $@
+pngtest.o:      pngtest.c
+        ${CC} ${CPPFLAGS} ${CFLAGS} -c ${.ALLSRC} -o ${.TARGET}
+pngtest:        pngtest.o
+        ${CC} ${LDFLAGS} ${.ALLSRC} -o ${.TARGET} -L${.OBJDIR} -lpng -lz -lm
+test:   pngtest
+        cd ${.OBJDIR} && env \
+                LD_LIBRARY_PATH="${.OBJDIR}" ${.OBJDIR}/pngtest
+beforeinstall:
+        if [ ! -d ${DESTDIR}${PREFIX}/include/libpng ]; then \
+          ${INSTALL} -d -o root -g wheel ${DESTDIR}${PREFIX}/include; \
+        fi
+        if [ ! -d ${DESTDIR}${LIBDIR} ]; then \
+          ${INSTALL} -d -o root -g wheel ${DESTDIR}${LIBDIR}; \
+        fi
+        if [ ! -d ${DESTDIR}${LIBDIR}/debug ]; then \
+          ${INSTALL} -d -o root -g wheel ${DESTDIR}${LIBDIR}/debug; \
+        fi
+        if [ ! -d ${DESTDIR}${MANDIR}3 ]; then \
+          ${INSTALL} -d -o root -g wheel ${DESTDIR}${MANDIR}3; \
+        fi
+        if [ ! -d ${DESTDIR}${MANDIR}5 ]; then \
+          ${INSTALL} -d -o root -g wheel ${DESTDIR}${MANDIR}5; \
+        fi
+        if [ ! -d ${DESTDIR}${PREFIX}/share/doc/png ]; then \
+          ${INSTALL} -d -o root -g wheel ${DESTDIR}${PREFIX}/share/doc/png; \
+        fi
+afterinstall:
+        @rm -f ${DESTDIR}${LIBDIR}/libpng_pic.a
+        @rm -f ${DESTDIR}${LIBDIR}/debug/libpng.a
+        @rm -f ${DESTDIR}${PREFIX}/include/png.h
+        @rm -f ${DESTDIR}${PREFIX}/include/pngconf.h
+        @rm -f ${DESTDIR}${PREFIX}/include/pnglibconf.h
+        @rmdir ${DESTDIR}${LIBDIR}/debug 2>/dev/null || true
+        ${INSTALL} ${INSTALL_COPY} -o ${SHAREOWN} -g ${SHAREGRP} \
+                -m ${NONBINMODE} ${HDRS} ${DESTDIR}${PREFIX}/include
+        ${INSTALL} ${INSTALL_COPY} -o ${SHAREOWN} -g ${SHAREGRP} \
+                -m ${NONBINMODE} ${HDRS} ${DESTDIR}${PREFIX}/include
+        ${INSTALL} ${INSTALL_COPY} -o ${SHAREOWN} -g ${SHAREGRP} \
+                -m ${NONBINMODE} ${DOCS} ${DESTDIR}${PREFIX}/share/doc/png
+.include <bsd.lib.mk>
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.sco b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.sco
new file mode 100644
index 0000000..9841e89
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.sco
@@ -0,0 +1,218 @@
+# makefile for SCO OSr5  ELF and Unixware 7 with Native cc
+# Contributed by Mike Hopkirk (hops@sco.com) modified from Makefile.lnx
+#   force ELF build dynamic linking, SONAME setting in lib and RPATH in app
+# Copyright (C) 2002, 2006, 2010-2011 Glenn Randers-Pehrson
+# Copyright (C) 1998 Greg Roelofs
+# Copyright (C) 1996, 1997 Andreas Dilger
+#
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+# Library name:
+LIBNAME = libpng15
+PNGMAJ = 15
+# Shared library names:
+LIBSO=$(LIBNAME).so
+LIBSOMAJ=$(LIBNAME).so.$(PNGMAJ)
+LIBSOREL=$(LIBSOMAJ).$(RELEASE)
+OLDSO=libpng.so
+# Utilities:
+CC=cc
+AR_RC=ar rc
+MKDIR_P=mkdir
+LN_SF=ln -f -s
+RANLIB=echo
+RM_F=/bin/rm -f
+# where make install puts libpng.a, $(OLDSO)*, and png.h
+prefix=/usr/local
+exec_prefix=$(prefix)
+# Where the zlib library and include files are located
+#ZLIBLIB=/usr/local/lib
+#ZLIBINC=/usr/local/include
+ZLIBLIB=../zlib
+ZLIBINC=../zlib
+CFLAGS= -dy -belf -I$(ZLIBINC) -O3
+LDFLAGS=-L. -L$(ZLIBLIB) -lpng15 -lz -lm
+INCPATH=$(prefix)/include
+LIBPATH=$(exec_prefix)/lib
+MANPATH=$(prefix)/man
+BINPATH=$(exec_prefix)/bin
+# override DESTDIR= on the make install command line to easily support
+# installing into a temporary location.  Example:
+#
+#    make install DESTDIR=/tmp/build/libpng
+#
+# If you're going to install into a temporary location
+# via DESTDIR, $(DESTDIR)$(prefix) must already exist before
+# you execute make install.
+DESTDIR=
+DB=$(DESTDIR)$(BINPATH)
+DI=$(DESTDIR)$(INCPATH)
+DL=$(DESTDIR)$(LIBPATH)
+DM=$(DESTDIR)$(MANPATH)
+OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
+        pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
+        pngwtran.o pngmem.o pngerror.o pngpread.o
+OBJSDLL = $(OBJS:.o=.pic.o)
+.SUFFIXES:      .c .o .pic.o
+.c.pic.o:
+        $(CC) -c $(CFLAGS) -KPIC -o $@ $*.c
+all: libpng.a $(LIBSO) pngtest libpng.pc libpng-config
+# see scripts/pnglibconf.mak for more options
+pnglibconf.h: scripts/pnglibconf.h.prebuilt
+        cp scripts/pnglibconf.h.prebuilt $@
+libpng.a: $(OBJS)
+        $(AR_RC) $@ $(OBJS)
+        $(RANLIB) $@
+libpng.pc:
+        cat scripts/libpng.pc.in | sed -e s!@prefix@!$(prefix)! \
+        -e s!@exec_prefix@!$(exec_prefix)! \
+        -e s!@libdir@!$(LIBPATH)! \
+        -e s!@includedir@!$(INCPATH)! \
+        -e s!-lpng15!-lpng15\ -lz\ -lm! > libpng.pc
+libpng-config:
+        ( cat scripts/libpng-config-head.in; \
+        echo prefix=\"$(prefix)\"; \
+        echo I_opts=\"-I$(INCPATH)/$(LIBNAME)\"; \
+        echo ccopts=\"-belf\"; \
+        echo L_opts=\"-L$(LIBPATH)\"; \
+        echo libs=\"-lpng15 -lz -lm\"; \
+        cat scripts/libpng-config-body.in ) > libpng-config
+        chmod +x libpng-config
+$(LIBSO): $(LIBSOMAJ)
+        $(LN_SF) $(LIBSOMAJ) $(LIBSO)
+$(LIBSOMAJ): $(OBJSDLL)
+        $(CC) -G  -Wl,-h,$(LIBSOMAJ) -o $(LIBSOMAJ) \
+         $(OBJSDLL)
+pngtest: pngtest.o $(LIBSO)
+        LD_RUN_PATH=.:$(ZLIBLIB) $(CC) -o pngtest $(CFLAGS) pngtest.o $(LDFLAGS)
+test: pngtest
+        ./pngtest
+install-headers: png.h pngconf.h pnglibconf.h
+        -@if [ ! -d $(DI) ]; then $(MKDIR_P) $(DI); fi
+        -@if [ ! -d $(DI)/$(LIBNAME) ]; then $(MKDIR_P) $(DI)/$(LIBNAME); fi
+        -@$(RM_F) $(DI)/png.h
+        -@$(RM_F) $(DI)/pngconf.h
+        -@$(RM_F) $(DI)/pnglibconf.h
+        cp png.h pngconf.h pnglibconf.h $(DI)/$(LIBNAME)
+        chmod 644 $(DI)/$(LIBNAME)/png.h $(DI)/$(LIBNAME)/pngconf.h $(DI)/$(LIBNAME)/pnglibconf.h
+        -@$(RM_F) $(DI)/png.h $(DI)/pngconf.h $(DI)/pnglibconf.h
+        -@$(RM_F) $(DI)/libpng
+        (cd $(DI); $(LN_SF) $(LIBNAME) libpng; $(LN_SF) $(LIBNAME)/* .)
+install-static: install-headers libpng.a
+        -@if [ ! -d $(DL) ]; then $(MKDIR_P) $(DL); fi
+        cp libpng.a $(DL)/$(LIBNAME).a
+        chmod 644 $(DL)/$(LIBNAME).a
+        -@$(RM_F) $(DL)/libpng.a
+        (cd $(DL); $(LN_SF) $(LIBNAME).a libpng.a)
+install-shared: install-headers $(LIBSOMAJ) libpng.pc
+        -@if [ ! -d $(DL) ]; then $(MKDIR_P) $(DL); fi
+        -@$(RM_F) $(DL)/$(LIBSO)
+        -@$(RM_F) $(DL)/$(LIBSOREL)
+        -@$(RM_F) $(DL)/$(OLDSO)
+        cp $(LIBSOMAJ) $(DL)/$(LIBSOREL)
+        chmod 755 $(DL)/$(LIBSOREL)
+        (cd $(DL); \
+        $(LN_SF) $(LIBSOREL) $(LIBSO); \
+        $(LN_SF) $(LIBSO) $(OLDSO))
+        -@if [ ! -d $(DL)/pkgconfig ]; then $(MKDIR_P) $(DL)/pkgconfig; fi
+        -@$(RM_F) $(DL)/pkgconfig/$(LIBNAME).pc
+        -@$(RM_F) $(DL)/pkgconfig/libpng.pc
+        cp libpng.pc $(DL)/pkgconfig/$(LIBNAME).pc
+        chmod 644 $(DL)/pkgconfig/$(LIBNAME).pc
+        (cd $(DL)/pkgconfig; $(LN_SF) $(LIBNAME).pc libpng.pc)
+install-man: libpng.3 libpngpf.3 png.5
+        -@if [ ! -d $(DM) ]; then $(MKDIR_P) $(DM); fi
+        -@if [ ! -d $(DM)/man3 ]; then $(MKDIR_P) $(DM)/man3; fi
+        -@$(RM_F) $(DM)/man3/libpng.3
+        -@$(RM_F) $(DM)/man3/libpngpf.3
+        cp libpng.3 $(DM)/man3
+        cp libpngpf.3 $(DM)/man3
+        -@if [ ! -d $(DM)/man5 ]; then $(MKDIR_P) $(DM)/man5; fi
+        -@$(RM_F) $(DM)/man5/png.5
+        cp png.5 $(DM)/man5
+install-config: libpng-config
+        -@if [ ! -d $(DB) ]; then $(MKDIR_P) $(DB); fi
+        -@$(RM_F) $(DB)/libpng-config
+        -@$(RM_F) $(DB)/$(LIBNAME)-config
+        cp libpng-config $(DB)/$(LIBNAME)-config
+        chmod 755 $(DB)/$(LIBNAME)-config
+        (cd $(DB); $(LN_SF) $(LIBNAME)-config libpng-config)
+install: install-static install-shared install-man install-config
+# If you installed in $(DESTDIR), test-installed won't work until you
+# move the library to its final location.  Use test-dd to test it
+# before then.
+test-dd:
+        echo
+        echo Testing installed dynamic shared library in $(DL).
+        $(CC) -I$(DI) $(CFLAGS) \
+           `$(BINPATH)/$(LIBNAME)-config --cflags` pngtest.c \
+           -L$(DL) -L$(ZLIBLIB) \
+           -o pngtestd `$(BINPATH)/$(LIBNAME)-config --ldflags`
+        ./pngtestd pngtest.png
+test-installed:
+        $(CC) $(CFLAGS) \
+           `$(BINPATH)/$(LIBNAME)-config --cflags` pngtest.c \
+           -L$(ZLIBLIB) \
+           -o pngtesti `$(BINPATH)/$(LIBNAME)-config --ldflags`
+        ./pngtesti pngtest.png
+clean:
+        $(RM_F) *.o libpng.a pngtest pngout.png libpng-config \
+        $(LIBSO) $(LIBSOMAJ)* pngtest-static pngtesti \
+        pnglibconf.h libpng.pc
+DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
+writelock:
+        chmod a-w *.[ch35] $(DOCS) scripts/*
+# DO NOT DELETE THIS LINE -- make depend depends on it.
+png.o png.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngerror.o pngerror.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrio.o pngrio.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwio.o pngwio.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngmem.o pngmem.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngset.o pngset.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngget.o pngget.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngread.o pngread.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrtran.o pngrtran.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrutil.o pngrutil.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtrans.o pngtrans.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwrite.o pngwrite.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwtran.o pngwtran.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwutil.o pngwutil.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngpread.o pngpread.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtest.o: png.h pngconf.h pnglibconf.h
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.sggcc b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.sggcc
new file mode 100644
index 0000000..acc1006
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.sggcc
@@ -0,0 +1,228 @@
+# makefile for libpng.a and libpng15.so, SGI IRIX with 'cc'
+# Copyright (C) 2001-2002, 2006, 2010-2011 Glenn Randers-Pehrson
+# Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
+#
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+# Library name:
+LIBNAME=libpng15
+PNGMAJ = 15
+# Shared library names:
+LIBSO=$(LIBNAME).so
+LIBSOMAJ=$(LIBNAME).so.$(PNGMAJ)
+LIBSOREL=$(LIBSOMAJ).$(RELEASE)
+OLDSO=libpng.so
+# Utilities:
+AR_RC=ar rc
+CC=gcc
+MKDIR_P=mkdir -p
+LN_SF=ln -sf
+RANLIB=echo
+RM_F=/bin/rm -f
+# Where make install puts libpng.a, libpng15.so, and libpng15/png.h
+# Prefix must be a full pathname.
+prefix=/usr/local
+exec_prefix=$(prefix)
+# Where the zlib library and include files are located
+#ZLIBLIB=/usr/local/lib32
+#ZLIBINC=/usr/local/include
+#ZLIBLIB=/usr/local/lib
+#ZLIBINC=/usr/local/include
+ZLIBLIB=../zlib
+ZLIBINC=../zlib
+# ABI can be blank to use default for your system, -32, -o32, -n32, or -64
+# See "man abi".  zlib must be built with the same ABI.
+ABI=
+WARNMORE= # -g -DPNG_DEBUG=5
+CFLAGS=$(ABI) -I$(ZLIBINC) -O $(WARNMORE) -fPIC -mabi=n32
+LDFLAGS=$(ABI) -L. -L$(ZLIBLIB) -lpng -lz -lm
+LDSHARED=cc $(ABI) -shared -soname $(LIBSOMAJ) \
+        -set_version sgi$(PNGMAJ).0
+# See "man dso" for info about shared objects
+INCPATH=$(prefix)/include
+LIBPATH=$(exec_prefix)/lib
+#LIBPATH=$(exec_prefix)/lib32
+MANPATH=$(prefix)/man
+BINPATH=$(exec_prefix)/bin
+# override DESTDIR= on the make install command line to easily support
+# installing into a temporary location.  Example:
+#
+#    make install DESTDIR=/tmp/build/libpng
+#
+# If you're going to install into a temporary location
+# via DESTDIR, $(DESTDIR)$(prefix) must already exist before
+# you execute make install.
+DESTDIR=
+DB=$(DESTDIR)$(BINPATH)
+DI=$(DESTDIR)$(INCPATH)
+DL=$(DESTDIR)$(LIBPATH)
+DM=$(DESTDIR)$(MANPATH)
+OBJS =  png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
+        pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
+        pngwtran.o pngmem.o pngerror.o pngpread.o
+all: libpng.a pngtest shared libpng.pc libpng-config
+# see scripts/pnglibconf.mak for more options
+pnglibconf.h: scripts/pnglibconf.h.prebuilt
+        cp scripts/pnglibconf.h.prebuilt $@
+libpng.a: $(OBJS)
+        $(AR_RC) $@ $(OBJS)
+        $(RANLIB) $@
+shared: $(LIBSOMAJ)
+libpng.pc:
+        cat scripts/libpng.pc.in | sed -e s!@prefix@!$(prefix)! \
+        -e s!@exec_prefix@!$(exec_prefix)! \
+        -e s!@libdir@!$(LIBPATH)! \
+        -e s!@includedir@!$(INCPATH)! \
+        -e s!-lpng15!-lpng15\ -lz\ -lm! > libpng.pc
+libpng-config:
+        ( cat scripts/libpng-config-head.in; \
+        echo prefix=\"$(prefix)\"; \
+        echo I_opts=\"-I$(INCPATH)/$(LIBNAME)\"; \
+        echo ccopts=\"$(ABI)\"; \
+        echo cppflags=\"\"; \
+        echo ldopts=\"$(ABI)\"; \
+        echo L_opts=\"-L$(LIBPATH)\"; \
+        echo libdir=\"$(LIBPATH)\"; \
+        echo libs=\"-lpng15 -lz -lm\"; \
+        cat scripts/libpng-config-body.in ) > libpng-config
+        chmod +x libpng-config
+$(LIBSO): $(LIBSOMAJ)
+        $(LN_SF) $(LIBSOMAJ) $(LIBSO)
+$(LIBSOMAJ): $(OBJS)
+        $(LDSHARED) -o $@ $(OBJS)
+        $(RM_F) $(LIBSO) $(LIBSOMAJ)
+pngtest: pngtest.o libpng.a
+        $(CC) -o pngtest $(CFLAGS) pngtest.o $(LDFLAGS)
+test: pngtest
+        echo
+        echo Testing local static library.
+        ./pngtest
+install-headers: png.h pngconf.h pnglibconf.h
+        -@if [ ! -d $(DI) ]; then $(MKDIR_P) $(DI); fi
+        -@if [ ! -d $(DI)/$(LIBNAME) ]; then $(MKDIR_P) $(DI)/$(LIBNAME); fi
+        cp png.h pngconf.h pnglibconf.h $(DI)/$(LIBNAME)
+        chmod 644 $(DI)/$(LIBNAME)/png.h $(DI)/$(LIBNAME)/pngconf.h $(DI)/$(LIBNAME)/pnglibconf.h
+        -@$(RM_F) $(DI)/png.h $(DI)/pngconf.h $(DI)/pnglibconf.h
+        -@$(RM_F) $(DI)/libpng
+        (cd $(DI); $(LN_SF) $(LIBNAME) libpng; $(LN_SF) $(LIBNAME)/* .)
+install-static: install-headers libpng.a
+        -@if [ ! -d $(DL) ]; then $(MKDIR_P) $(DL); fi
+        cp libpng.a $(DL)/$(LIBNAME).a
+        chmod 644 $(DL)/$(LIBNAME).a
+        -@$(RM_F) $(DL)/libpng.a
+        (cd $(DL); $(LN_SF) $(LIBNAME).a libpng.a)
+install-shared: install-headers $(LIBSOMAJ) libpng.pc
+        -@if [ ! -d $(DL) ]; then $(MKDIR_P) $(DL); fi
+        -@$(RM_F) $(DL)/$(LIBSO)
+        -@$(RM_F) $(DL)/$(LIBSOREL)
+        -@$(RM_F) $(DL)/$(OLDSO)
+        cp $(LIBSOMAJ) $(DL)/$(LIBSOREL)
+        chmod 755 $(DL)/$(LIBSOREL)
+        (cd $(DL); \
+        $(LN_SF) $(LIBSOREL) $(LIBSO); \
+        $(LN_SF) $(LIBSO) $(OLDSO))
+        -@if [ ! -d $(DL)/pkgconfig ]; then $(MKDIR_P) $(DL)/pkgconfig; fi
+        -@$(RM_F) $(DL)/pkgconfig/$(LIBNAME).pc
+        -@$(RM_F) $(DL)/pkgconfig/libpng.pc
+        cp libpng.pc $(DL)/pkgconfig/$(LIBNAME).pc
+        chmod 644 $(DL)/pkgconfig/$(LIBNAME).pc
+        (cd $(DL)/pkgconfig; $(LN_SF) $(LIBNAME).pc libpng.pc)
+install-man: libpng.3 libpngpf.3 png.5
+        -@if [ ! -d $(DM) ]; then $(MKDIR_P) $(DM); fi
+        -@if [ ! -d $(DM)/man3 ]; then $(MKDIR_P) $(DM)/man3; fi
+        -@$(RM_F) $(DM)/man3/libpng.3
+        -@$(RM_F) $(DM)/man3/libpngpf.3
+        cp libpng.3 $(DM)/man3
+        cp libpngpf.3 $(DM)/man3
+        -@if [ ! -d $(DM)/man5 ]; then $(MKDIR_P) $(DM)/man5; fi
+        -@$(RM_F) $(DM)/man5/png.5
+        cp png.5 $(DM)/man5
+install-config: libpng-config
+        -@if [ ! -d $(DB) ]; then $(MKDIR_P) $(DB); fi
+        -@$(RM_F) $(DB)/libpng-config
+        -@$(RM_F) $(DB)/$(LIBNAME)-config
+        cp libpng-config $(DB)/$(LIBNAME)-config
+        chmod 755 $(DB)/$(LIBNAME)-config
+        (cd $(DB); $(LN_SF) $(LIBNAME)-config libpng-config)
+install: install-static install-shared install-man install-config
+# If you installed in $(DESTDIR), test-installed won't work until you
+# move the library to its final location.  Use test-dd to test it
+# before then.
+test-dd:
+        echo
+        echo Testing installed dynamic shared library in $(DL).
+        $(CC) -I$(DI) -I$(ZLIBINC) \
+           `$(BINPATH)/$(LIBNAME)-config --cflags` pngtest.c \
+           -L$(DL) -L$(ZLIBLIB) \
+           -rpath $(ZLIBLIB):$(DL) \
+           -o pngtestd `$(BINPATH)/$(LIBNAME)-config --ldflags`
+        ./pngtestd pngtest.png
+test-installed:
+        echo
+        echo Testing installed dynamic shared library.
+        $(CC) -I$(ZLIBINC) \
+           `$(BINPATH)/$(LIBNAME)-config --cflags` pngtest.c \
+           -L$(ZLIBLIB) \
+           -rpath $(ZLIBLIB):`$(BINPATH)/$(LIBNAME)-config --libdir` \
+           -o pngtesti `$(BINPATH)/$(LIBNAME)-config --ldflags`
+        ./pngtesti pngtest.png
+clean:
+        $(RM_F) libpng.a pngtest pngtesti pngout.png libpng.pc \
+        so_locations libpng-config $(LIBSO) $(LIBSOMAJ)* pnglibconf.h
+DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
+writelock:
+        chmod a-w *.[ch35] $(DOCS) scripts/*
+# DO NOT DELETE THIS LINE -- make depend depends on it.
+png.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngerror.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrio.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwio.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngmem.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngset.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngget.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngread.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrtran.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrutil.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtrans.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwrite.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwtran.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwutil.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngpread.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtest.o: png.h pngconf.h pnglibconf.h
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.sgi b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.sgi
new file mode 100644
index 0000000..ab44f2d
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.sgi
@@ -0,0 +1,229 @@
+# makefile for libpng.a and libpng15.so, SGI IRIX with 'cc'
+# Copyright (C) 2001-2002, 2006, 2007, 2010-2011 Glenn Randers-Pehrson
+# Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
+#
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+# Library name:
+LIBNAME=libpng15
+PNGMAJ = 15
+# Shared library names:
+LIBSO=$(LIBNAME).so
+LIBSOMAJ=$(LIBNAME).so.$(PNGMAJ)
+LIBSOREL=$(LIBSOMAJ).$(RELEASE)
+OLDSO=libpng.so
+# Utilities:
+AR_RC=ar rc
+CC=cc
+MKDIR_P=mkdir -p
+LN_SF=ln -sf
+RANLIB=echo
+RM_F=/bin/rm -f
+# Where make install puts libpng.a, libpng15.so, and libpng15/png.h
+# Prefix must be a full pathname.
+prefix=/usr/local
+exec_prefix=$(prefix)
+# Where the zlib library and include files are located
+#ZLIBLIB=/usr/local/lib32
+#ZLIBINC=/usr/local/include
+#ZLIBLIB=/usr/local/lib
+#ZLIBINC=/usr/local/include
+ZLIBLIB=../zlib
+ZLIBINC=../zlib
+# ABI can be blank to use default for your system, -32, -o32, -n32, or -64
+# See "man abi".  zlib must be built with the same ABI.
+ABI=
+WARNMORE=-fullwarn
+# Note: -KPIC is the default anyhow
+#CFLAGS= $(ABI) -I$(ZLIBINC) -O $(WARNMORE) -KPIC # -g -DPNG_DEBUG=5
+CFLAGS=$(ABI) -I$(ZLIBINC) -O $(WARNMORE)
+LDFLAGS_A=$(ABI) -L. -L$(ZLIBLIB) -lpng15 -lz -lm
+LDFLAGS=$(ABI) -L. -L$(ZLIBLIB) -lpng -lz -lm
+LDSHARED=cc $(ABI) -shared -soname $(LIBSOMAJ) \
+        -set_version sgi$(PNGMAJ).0
+# See "man dso" for info about shared objects
+INCPATH=$(prefix)/include
+LIBPATH=$(exec_prefix)/lib
+#LIBPATH=$(exec_prefix)/lib32
+MANPATH=$(prefix)/man
+BINPATH=$(exec_prefix)/bin
+# override DESTDIR= on the make install command line to easily support
+# installing into a temporary location.  Example:
+#
+#    make install DESTDIR=/tmp/build/libpng
+#
+# If you're going to install into a temporary location
+# via DESTDIR, $(DESTDIR)$(prefix) must already exist before
+# you execute make install.
+DESTDIR=
+DB=$(DESTDIR)$(BINPATH)
+DI=$(DESTDIR)$(INCPATH)
+DL=$(DESTDIR)$(LIBPATH)
+DM=$(DESTDIR)$(MANPATH)
+OBJS =  png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
+        pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
+        pngwtran.o pngmem.o pngerror.o pngpread.o
+all: libpng.a pngtest shared libpng.pc libpng-config
+# see scripts/pnglibconf.mak for more options
+pnglibconf.h: scripts/pnglibconf.h.prebuilt
+        cp scripts/pnglibconf.h.prebuilt $@
+libpng.a: $(OBJS)
+        $(AR_RC) $@ $(OBJS)
+        $(RANLIB) $@
+libpng.pc:
+        cat scripts/libpng.pc.in | sed -e s!@prefix@!$(prefix)! \
+        -e s!@exec_prefix@!$(exec_prefix)! \
+        -e s!@libdir@!$(LIBPATH)! \
+        -e s!@includedir@!$(INCPATH)! \
+        -e s!-lpng15!-lpng15\ -lz\ -lm! > libpng.pc
+libpng-config:
+        ( cat scripts/libpng-config-head.in; \
+        echo prefix=\"$(prefix)\"; \
+        echo I_opts=\"-I$(INCPATH)/$(LIBNAME)\"; \
+        echo ccopts=\"$(ABI)\"; \
+        echo ldopts=\"$(ABI)\"; \
+        echo L_opts=\"-L$(LIBPATH)\"; \
+        echo libdir=\"$(LIBPATH)\"; \
+        echo libs=\"-lpng15 -lz -lm\"; \
+        cat scripts/libpng-config-body.in ) > libpng-config
+        chmod +x libpng-config
+$(LIBSO): $(LIBSOMAJ)
+        $(LN_SF) $(LIBSOMAJ) $(LIBSO)
+$(LIBSOMAJ): $(OBJS)
+        $(LDSHARED) -o $@ $(OBJS)
+        $(RM_F) $(LIBSO) $(LIBSOMAJ)
+pngtest: pngtest.o libpng.a
+        $(CC) -o pngtest $(CFLAGS) pngtest.o $(LDFLAGS)
+test: pngtest
+        echo
+        echo Testing local static library.
+        ./pngtest
+install-headers: png.h pngconf.h pnglibconf.h
+        -@if [ ! -d $(DI) ]; then $(MKDIR_P) $(DI); fi
+        -@if [ ! -d $(DI)/$(LIBNAME) ]; then $(MKDIR_P) $(DI)/$(LIBNAME); fi
+        cp png.h pngconf.h pnglibconf.h $(DI)/$(LIBNAME)
+        chmod 644 $(DI)/$(LIBNAME)/png.h $(DI)/$(LIBNAME)/pngconf.h $(DI)/$(LIBNAME)/pnglibconf.h
+        -@$(RM_F) $(DI)/png.h $(DI)/pngconf.h $(DI)/pnglibconf.h
+        -@$(RM_F) $(DI)/libpng
+        (cd $(DI); $(LN_SF) $(LIBNAME) libpng; $(LN_SF) $(LIBNAME)/* .)
+install-static: install-headers libpng.a
+        -@if [ ! -d $(DL) ]; then $(MKDIR_P) $(DL); fi
+        cp libpng.a $(DL)/$(LIBNAME).a
+        chmod 644 $(DL)/$(LIBNAME).a
+        -@$(RM_F) $(DL)/libpng.a
+        (cd $(DL); $(LN_SF) $(LIBNAME).a libpng.a)
+install-shared: install-headers $(LIBSOMAJ) libpng.pc
+        -@if [ ! -d $(DL) ]; then $(MKDIR_P) $(DL); fi
+        -@$(RM_F) $(DL)/$(LIBSO)
+        -@$(RM_F) $(DL)/$(LIBSOREL)
+        -@$(RM_F) $(DL)/$(OLDSO)
+        cp $(LIBSOMAJ) $(DL)/$(LIBSOREL)
+        chmod 755 $(DL)/$(LIBSOREL)
+        (cd $(DL); \
+        $(LN_SF) $(LIBSOREL) $(LIBSO); \
+        $(LN_SF) $(LIBSO) $(OLDSO))
+        -@if [ ! -d $(DL)/pkgconfig ]; then $(MKDIR_P) $(DL)/pkgconfig; fi
+        -@$(RM_F) $(DL)/pkgconfig/$(LIBNAME).pc
+        -@$(RM_F) $(DL)/pkgconfig/libpng.pc
+        cp libpng.pc $(DL)/pkgconfig/$(LIBNAME).pc
+        chmod 644 $(DL)/pkgconfig/$(LIBNAME).pc
+        (cd $(DL)/pkgconfig; $(LN_SF) $(LIBNAME).pc libpng.pc)
+install-man: libpng.3 libpngpf.3 png.5
+        -@if [ ! -d $(DM) ]; then $(MKDIR_P) $(DM); fi
+        -@if [ ! -d $(DM)/man3 ]; then $(MKDIR_P) $(DM)/man3; fi
+        -@$(RM_F) $(DM)/man3/libpng.3
+        -@$(RM_F) $(DM)/man3/libpngpf.3
+        cp libpng.3 $(DM)/man3
+        cp libpngpf.3 $(DM)/man3
+        -@if [ ! -d $(DM)/man5 ]; then $(MKDIR_P) $(DM)/man5; fi
+        -@$(RM_F) $(DM)/man5/png.5
+        cp png.5 $(DM)/man5
+install-config: libpng-config
+        -@if [ ! -d $(DB) ]; then $(MKDIR_P) $(DB); fi
+        -@$(RM_F) $(DB)/libpng-config
+        -@$(RM_F) $(DB)/$(LIBNAME)-config
+        cp libpng-config $(DB)/$(LIBNAME)-config
+        chmod 755 $(DB)/$(LIBNAME)-config
+        (cd $(DB); $(LN_SF) $(LIBNAME)-config libpng-config)
+install: install-static install-shared install-man install-config
+# If you installed in $(DESTDIR), test-installed won't work until you
+# move the library to its final location.  Use test-dd to test it
+# before then.
+test-dd:
+        echo
+        echo Testing installed dynamic shared library in $(DL).
+        $(CC) -I$(DI) -I$(ZLIBINC) \
+           `$(BINPATH)/$(LIBNAME)-config --cflags` pngtest.c \
+           -L$(DL) -L$(ZLIBLIB) \
+           -rpath $(ZLIBLIB):$(DL) \
+           -o pngtestd `$(BINPATH)/$(LIBNAME)-config --ldflags`
+        ./pngtestd pngtest.png
+test-installed:
+        echo
+        echo Testing installed dynamic shared library.
+        $(CC) -I$(ZLIBINC) \
+           `$(BINPATH)/$(LIBNAME)-config --cflags` pngtest.c \
+           -L$(ZLIBLIB) \
+           -rpath $(ZLIBLIB):`$(BINPATH)/$(LIBNAME)-config --libdir` \
+           -o pngtesti `$(BINPATH)/$(LIBNAME)-config --ldflags`
+        ./pngtesti pngtest.png
+clean:
+        $(RM_F) *.o libpng.a pngtest pngtesti pngout.png libpng.pc libpng-config \
+        $(LIBSO) $(LIBSOMAJ)* \
+        so_locations pnglibconf.h
+DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
+writelock:
+        chmod a-w *.[ch35] $(DOCS) scripts/*
+# DO NOT DELETE THIS LINE -- make depend depends on it.
+png.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngerror.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrio.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwio.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngmem.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngset.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngget.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngread.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrtran.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrutil.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtrans.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwrite.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwtran.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwutil.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngpread.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtest.o: png.h pngconf.h pnglibconf.h
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.so9 b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.so9
new file mode 100644
index 0000000..967b342
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.so9
@@ -0,0 +1,239 @@
+# makefile for libpng on Solaris 9 (beta) with Forte cc
+# Updated by Chad Schrock for Solaris 9
+# Contributed by William L. Sebok, based on makefile.linux
+# Copyright (C) 2002, 2006, 2008, 2010-2011 Glenn Randers-Pehrson
+# Copyright (C) 1998-2001 Greg Roelofs
+# Copyright (C) 1996-1997 Andreas Dilger
+#
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+# Library name:
+PNGMAJ = 15
+LIBNAME = libpng15
+# Shared library names:
+LIBSO=$(LIBNAME).so
+LIBSOMAJ=$(LIBNAME).so.$(PNGMAJ)
+LIBSOREL=$(LIBSOMAJ).$(RELEASE)
+OLDSO=libpng.so
+# Utilities:
+# gcc 2.95 doesn't work.
+CC=cc
+AR_RC=ar rc
+MKDIR_P=mkdir -p
+LN_SF=ln -f -s
+RANLIB=echo
+RM_F=/bin/rm -f
+# Where make install puts libpng.a, $(OLDSO)*, and png.h
+prefix=/usr/local
+exec_prefix=$(prefix)
+# Where the zlib library and include files are located
+# Changing these to ../zlib poses a security risk.  If you want
+# to have zlib in an adjacent directory, specify the full path instead of "..".
+#ZLIBLIB=../zlib
+#ZLIBINC=../zlib
+#ZLIBLIB=/usr/local/lib
+#ZLIBINC=/usr/local/include
+#Use the preinstalled zlib that comes with Solaris 9:
+ZLIBLIB=/usr/lib
+ZLIBINC=/usr/include
+#WARNMORE=-Wwrite-strings -Wpointer-arith -Wshadow \
+        -Wmissing-declarations -Wtraditional -Wcast-align \
+        -Wstrict-prototypes -Wmissing-prototypes #-Wconversion
+#CFLAGS=-I$(ZLIBINC) -W -Wall -O3 $(WARNMORE) -g -DPNG_DEBUG=5 -DPNG_NO_MMX_CODE
+CFLAGS=-I$(ZLIBINC) -O3 -DPNG_NO_MMX_CODE
+LDFLAGS=-L. -R. -L$(ZLIBLIB) -R$(ZLIBLIB) -lpng15 -lz -lm
+INCPATH=$(prefix)/include
+LIBPATH=$(exec_prefix)/lib
+MANPATH=$(prefix)/man
+BINPATH=$(exec_prefix)/bin
+# override DESTDIR= on the make install command line to easily support
+# installing into a temporary location.  Example:
+#
+#    make install DESTDIR=/tmp/build/libpng
+#
+# If you're going to install into a temporary location
+# via DESTDIR, $(DESTDIR)$(prefix) must already exist before
+# you execute make install.
+DESTDIR=
+DB=$(DESTDIR)$(BINPATH)
+DI=$(DESTDIR)$(INCPATH)
+DL=$(DESTDIR)$(LIBPATH)
+DM=$(DESTDIR)$(MANPATH)
+OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
+        pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
+        pngwtran.o pngmem.o pngerror.o pngpread.o
+OBJSDLL = $(OBJS:.o=.pic.o)
+.SUFFIXES:      .c .o .pic.o
+.c.pic.o:
+        $(CC) -c $(CFLAGS) -KPIC -o $@ $*.c
+all: libpng.a $(LIBSO) pngtest libpng.pc libpng-config
+# see scripts/pnglibconf.mak for more options
+pnglibconf.h: scripts/pnglibconf.h.prebuilt
+        cp scripts/pnglibconf.h.prebuilt $@
+libpng.a: $(OBJS)
+        $(AR_RC) $@ $(OBJS)
+        $(RANLIB) $@
+libpng.pc:
+        cat scripts/libpng.pc.in | sed -e s!@prefix@!$(prefix)! \
+        -e s!@exec_prefix@!$(exec_prefix)! \
+        -e s!@libdir@!$(LIBPATH)! \
+        -e s!@includedir@!$(INCPATH)! \
+        -e s!-lpng15!-lpng15\ -lz\ -lm! > libpng.pc
+libpng-config:
+        ( cat scripts/libpng-config-head.in; \
+        echo prefix=\"$(prefix)\"; \
+        echo I_opts=\"-I$(INCPATH)/$(LIBNAME)\"; \
+        echo L_opts=\"-L$(LIBPATH)\"; \
+        echo R_opts=\"-R$(LIBPATH)\"; \
+        echo libs=\"-lpng15 -lz -lm\"; \
+        cat scripts/libpng-config-body.in ) > libpng-config
+        chmod +x libpng-config
+$(LIBSO): $(LIBSOMAJ)
+        $(LN_SF) $(LIBSOMAJ) $(LIBSO)
+$(LIBSOMAJ): $(OBJSDLL)
+        @case "`type ld`" in *ucb*) \
+        echo; \
+        echo '## WARNING:'; \
+        echo '## The commands "CC" and "LD" must NOT refer to /usr/ucb/cc'; \
+        echo '## and /usr/ucb/ld.  If they do, you need to adjust your PATH'; \
+        echo '## environment variable to put /usr/ccs/bin ahead of /usr/ucb.'; \
+        echo '## The environment variable LD_LIBRARY_PATH should not be set'; \
+        echo '## at all.  If it is, things are likely to break because of'; \
+        echo '## the libucb dependency that is created.'; \
+        echo; \
+        ;; \
+        esac
+        $(LD) -G -h $(LIBSOMAJ) \
+         -o $(LIBSOMAJ) $(OBJSDLL)
+pngtest: pngtest.o $(LIBSO)
+        $(CC) -o pngtest $(CFLAGS) pngtest.o $(LDFLAGS)
+test: pngtest
+        ./pngtest
+install-headers: png.h pngconf.h pnglibconf.h
+        -@if [ ! -d $(DI) ]; then $(MKDIR_P) $(DI); fi
+        -@if [ ! -d $(DI)/$(LIBNAME) ]; then $(MKDIR_P) $(DI)/$(LIBNAME); fi
+        cp png.h pngconf.h pnglibconf.h $(DI)/$(LIBNAME)
+        chmod 644 $(DI)/$(LIBNAME)/png.h $(DI)/$(LIBNAME)/pngconf.h $(DI)/$(LIBNAME)/pnglibconf.h
+        -@$(RM_F) $(DI)/png.h $(DI)/pngconf.h $(DI)/pnglibconf.h
+        -@$(RM_F) $(DI)/libpng
+        (cd $(DI); $(LN_SF) $(LIBNAME) libpng; $(LN_SF) $(LIBNAME)/* .)
+install-static: install-headers libpng.a
+        -@if [ ! -d $(DL) ]; then $(MKDIR_P) $(DL); fi
+        cp libpng.a $(DL)/$(LIBNAME).a
+        chmod 644 $(DL)/$(LIBNAME).a
+        -@$(RM_F) $(DL)/libpng.a
+        (cd $(DL); $(LN_SF) $(LIBNAME).a libpng.a)
+install-shared: install-headers $(LIBSOMAJ) libpng.pc
+        -@if [ ! -d $(DL) ]; then $(MKDIR_P) $(DL); fi
+        -@$(RM_F) $(DL)/$(LIBSO)
+        -@$(RM_F) $(DL)/$(LIBSOREL)
+        -@$(RM_F) $(DL)/$(OLDSO)
+        cp $(LIBSOMAJ) $(DL)/$(LIBSOREL)
+        chmod 755 $(DL)/$(LIBSOREL)
+        (cd $(DL); \
+        $(LN_SF) $(LIBSOREL) $(LIBSO); \
+        $(LN_SF) $(LIBSO) $(OLDSO))
+        -@if [ ! -d $(DL)/pkgconfig ]; then $(MKDIR_P) $(DL)/pkgconfig; fi
+        -@$(RM_F) $(DL)/pkgconfig/$(LIBNAME).pc
+        -@$(RM_F) $(DL)/pkgconfig/libpng.pc
+        cp libpng.pc $(DL)/pkgconfig/$(LIBNAME).pc
+        chmod 644 $(DL)/pkgconfig/$(LIBNAME).pc
+        (cd $(DL)/pkgconfig; $(LN_SF) $(LIBNAME).pc libpng.pc)
+install-man: libpng.3 libpngpf.3 png.5
+        -@if [ ! -d $(DM) ]; then $(MKDIR_P) $(DM); fi
+        -@if [ ! -d $(DM)/man3 ]; then $(MKDIR_P) $(DM)/man3; fi
+        -@$(RM_F) $(DM)/man3/libpng.3
+        -@$(RM_F) $(DM)/man3/libpngpf.3
+        cp libpng.3 $(DM)/man3
+        cp libpngpf.3 $(DM)/man3
+        -@if [ ! -d $(DM)/man5 ]; then $(MKDIR_P) $(DM)/man5; fi
+        -@$(RM_F) $(DM)/man5/png.5
+        cp png.5 $(DM)/man5
+install-config: libpng-config
+        -@if [ ! -d $(DB) ]; then $(MKDIR_P) $(DB); fi
+        -@$(RM_F) $(DB)/libpng-config
+        -@$(RM_F) $(DB)/$(LIBNAME)-config
+        cp libpng-config $(DB)/$(LIBNAME)-config
+        chmod 755 $(DB)/$(LIBNAME)-config
+        (cd $(DB); $(LN_SF) $(LIBNAME)-config libpng-config)
+install: install-static install-shared install-man install-config
+# If you installed in $(DESTDIR), test-installed won't work until you
+# move the library to its final location.  Use test-dd to test it
+# before then.
+test-dd:
+        echo
+        echo Testing installed dynamic shared library in $(DL).
+        $(CC) -I$(DI) -I$(ZLIBINC) \
+           `$(BINPATH)/$(LIBNAME)-config --cflags` pngtest.c \
+           -o pngtestd `$(BINPATH)/$(LIBNAME)-config --ldflags` \
+           -L$(DL) -L$(ZLIBLIB)  -R$(ZLIBLIB) -R$(DL)
+        ./pngtestd pngtest.png
+test-installed:
+        echo
+        echo Testing installed dynamic shared library.
+        $(CC) -I$(ZLIBINC) \
+           `$(BINPATH)/$(LIBNAME)-config --cflags` pngtest.c \
+           -o pngtesti `$(BINPATH)/$(LIBNAME)-config --ldflags` \
+           -L$(ZLIBLIB) -R$(ZLIBLIB)
+        ./pngtesti pngtest.png
+clean:
+        $(RM_F) *.o libpng.a pngtest pngtesti pngout.png \
+        libpng-config $(LIBSO) $(LIBSOMAJ)* \
+        libpng.pc pnglibconf.h
+DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
+writelock:
+        chmod a-w *.[ch35] $(DOCS) scripts/*
+# DO NOT DELETE THIS LINE -- make depend depends on it.
+png.o png.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngerror.o pngerror.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrio.o pngrio.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwio.o pngwio.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngmem.o pngmem.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngset.o pngset.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngget.o pngget.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngread.o pngread.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrtran.o pngrtran.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrutil.o pngrutil.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtrans.o pngtrans.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwrite.o pngwrite.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwtran.o pngwtran.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwutil.o pngwutil.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngpread.o pngpread.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtest.o: png.h pngconf.h pnglibconf.h
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.solaris b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.solaris
new file mode 100644
index 0000000..03fb314
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.solaris
@@ -0,0 +1,236 @@
+# makefile for libpng on Solaris 2.x with gcc
+# Copyright (C) 2004, 2006-2008, 2010-2011 Glenn Randers-Pehrson
+# Contributed by William L. Sebok, based on makefile.linux
+# Copyright (C) 1998 Greg Roelofs
+# Copyright (C) 1996, 1997 Andreas Dilger
+#
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+# Library name:
+LIBNAME = libpng15
+PNGMAJ = 15
+# Shared library names:
+LIBSO=$(LIBNAME).so
+LIBSOMAJ=$(LIBNAME).so.$(PNGMAJ)
+LIBSOREL=$(LIBSOMAJ).$(RELEASE)
+OLDSO=libpng.so
+# Utilities:
+AR_RC=ar rc
+CC=gcc
+MKDIR_P=mkdir -p
+LN_SF=ln -f -s
+RANLIB=echo
+RM_F=/bin/rm -f
+# Where make install puts libpng.a, libpng15.so*, and png.h
+prefix=/usr/local
+exec_prefix=$(prefix)
+# Where the zlib library and include files are located
+# Changing these to ../zlib poses a security risk.  If you want
+# to have zlib in an adjacent directory, specify the full path instead of "..".
+#ZLIBLIB=../zlib
+#ZLIBINC=../zlib
+ZLIBLIB=/usr/local/lib
+ZLIBINC=/usr/local/include
+WARNMORE=-Wwrite-strings -Wpointer-arith -Wshadow \
+        -Wmissing-declarations -Wtraditional -Wcast-align \
+        -Wstrict-prototypes -Wmissing-prototypes #-Wconversion
+CFLAGS=-I$(ZLIBINC) -W -Wall -O \
+        # $(WARNMORE) -g -DPNG_DEBUG=5
+LDFLAGS=-L. -R. -L$(ZLIBLIB) -R$(ZLIBLIB) -lpng15 -lz -lm
+INCPATH=$(prefix)/include
+LIBPATH=$(exec_prefix)/lib
+MANPATH=$(prefix)/man
+BINPATH=$(exec_prefix)/bin
+# override DESTDIR= on the make install command line to easily support
+# installing into a temporary location.  Example:
+#
+#    make install DESTDIR=/tmp/build/libpng
+#
+# If you're going to install into a temporary location
+# via DESTDIR, $(DESTDIR)$(prefix) must already exist before
+# you execute make install.
+DESTDIR=
+DB=$(DESTDIR)$(BINPATH)
+DI=$(DESTDIR)$(INCPATH)
+DL=$(DESTDIR)$(LIBPATH)
+DM=$(DESTDIR)$(MANPATH)
+OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
+        pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
+        pngwtran.o pngmem.o pngerror.o pngpread.o
+OBJSDLL = $(OBJS:.o=.pic.o)
+.SUFFIXES:      .c .o .pic.o
+.c.pic.o:
+        $(CC) -c $(CFLAGS) -fPIC -o $@ $*.c
+all: libpng.a $(LIBSO) pngtest libpng.pc libpng-config
+# see scripts/pnglibconf.mak for more options
+pnglibconf.h: scripts/pnglibconf.h.prebuilt
+        cp scripts/pnglibconf.h.prebuilt $@
+libpng.a: $(OBJS)
+        $(AR_RC) $@ $(OBJS)
+        $(RANLIB) $@
+libpng.pc:
+        cat scripts/libpng.pc.in | sed -e s!@prefix@!$(prefix)! \
+        -e s!@exec_prefix@!$(exec_prefix)! \
+        -e s!@libdir@!$(LIBPATH)! \
+        -e s!@includedir@!$(INCPATH)! \
+        -e s!-lpng15!-lpng15\ -lz\ -lm! > libpng.pc
+libpng-config:
+        ( cat scripts/libpng-config-head.in; \
+        echo prefix=\"$(prefix)\"; \
+        echo I_opts=\"-I$(INCPATH)/$(LIBNAME)\"; \
+        echo cppflags=\"\"; \
+        echo L_opts=\"-L$(LIBPATH)\"; \
+        echo R_opts=\"-R$(LIBPATH)\"; \
+        echo libs=\"-lpng15 -lz -lm\"; \
+        cat scripts/libpng-config-body.in ) > libpng-config
+        chmod +x libpng-config
+$(LIBSO): $(LIBSOMAJ)
+        $(LN_SF) $(LIBSOMAJ) $(LIBSO)
+$(LIBSOMAJ): $(OBJSDLL)
+        @case "`type ld`" in *ucb*) \
+        echo; \
+        echo '## WARNING:'; \
+        echo '## The commands "CC" and "LD" must NOT refer to /usr/ucb/cc'; \
+        echo '## and /usr/ucb/ld.  If they do, you need to adjust your PATH'; \
+        echo '## environment variable to put /usr/ccs/bin ahead of /usr/ucb.'; \
+        echo '## The environment variable LD_LIBRARY_PATH should not be set'; \
+        echo '## at all.  If it is, things are likely to break because of'; \
+        echo '## the libucb dependency that is created.'; \
+        echo; \
+        ;; \
+        esac
+        $(LD) -G -h $(LIBSOMAJ) \
+         -o $(LIBSOMAJ) $(OBJSDLL)
+pngtest: pngtest.o $(LIBSO)
+        $(CC) -o pngtest $(CFLAGS) pngtest.o $(LDFLAGS)
+test: pngtest
+        ./pngtest
+install-headers: png.h pngconf.h pnglibconf.h
+        -@if [ ! -d $(DI) ]; then $(MKDIR_P) $(DI); fi
+        -@if [ ! -d $(DI)/$(LIBNAME) ]; then $(MKDIR_P) $(DI)/$(LIBNAME); fi
+        cp png.h pngconf.h pnglibconf.h $(DI)/$(LIBNAME)
+        chmod 644 $(DI)/$(LIBNAME)/png.h $(DI)/$(LIBNAME)/pngconf.h $(DI)/$(LIBNAME)/pnglibconf.h
+        -@$(RM_F) $(DI)/png.h $(DI)/pngconf.h $(DI)/pnglibconf.h
+        -@$(RM_F) $(DI)/libpng
+        (cd $(DI); $(LN_SF) $(LIBNAME) libpng; $(LN_SF) $(LIBNAME)/* .)
+install-static: install-headers libpng.a
+        -@if [ ! -d $(DL) ]; then $(MKDIR_P) $(DL); fi
+        cp libpng.a $(DL)/$(LIBNAME).a
+        chmod 644 $(DL)/$(LIBNAME).a
+        -@$(RM_F) $(DL)/libpng.a
+        (cd $(DL); $(LN_SF) $(LIBNAME).a libpng.a)
+install-shared: install-headers $(LIBSOMAJ) libpng.pc
+        -@if [ ! -d $(DL) ]; then $(MKDIR_P) $(DL); fi
+        -@$(RM_F) $(DL)/$(LIBSO)
+        -@$(RM_F) $(DL)/$(LIBSOREL)
+        -@$(RM_F) $(DL)/$(OLDSO)
+        cp $(LIBSOMAJ) $(DL)/$(LIBSOREL)
+        chmod 755 $(DL)/$(LIBSOREL)
+        (cd $(DL); \
+        $(LN_SF) $(LIBSOREL) $(LIBSO); \
+        $(LN_SF) $(LIBSO) $(OLDSO))
+        -@if [ ! -d $(DL)/pkgconfig ]; then $(MKDIR_P) $(DL)/pkgconfig; fi
+        -@$(RM_F) $(DL)/pkgconfig/$(LIBNAME).pc
+        -@$(RM_F) $(DL)/pkgconfig/libpng.pc
+        cp libpng.pc $(DL)/pkgconfig/$(LIBNAME).pc
+        chmod 644 $(DL)/pkgconfig/$(LIBNAME).pc
+        (cd $(DL)/pkgconfig; $(LN_SF) $(LIBNAME).pc libpng.pc)
+install-man: libpng.3 libpngpf.3 png.5
+        -@if [ ! -d $(DM) ]; then $(MKDIR_P) $(DM); fi
+        -@if [ ! -d $(DM)/man3 ]; then $(MKDIR_P) $(DM)/man3; fi
+        -@$(RM_F) $(DM)/man3/libpng.3
+        -@$(RM_F) $(DM)/man3/libpngpf.3
+        cp libpng.3 $(DM)/man3
+        cp libpngpf.3 $(DM)/man3
+        -@if [ ! -d $(DM)/man5 ]; then $(MKDIR_P) $(DM)/man5; fi
+        -@$(RM_F) $(DM)/man5/png.5
+        cp png.5 $(DM)/man5
+install-config: libpng-config
+        -@if [ ! -d $(DB) ]; then $(MKDIR_P) $(DB); fi
+        -@$(RM_F) $(DB)/libpng-config
+        -@$(RM_F) $(DB)/$(LIBNAME)-config
+        cp libpng-config $(DB)/$(LIBNAME)-config
+        chmod 755 $(DB)/$(LIBNAME)-config
+        (cd $(DB); $(LN_SF) $(LIBNAME)-config libpng-config)
+install: install-static install-shared install-man install-config
+# If you installed in $(DESTDIR), test-installed won't work until you
+# move the library to its final location.  Use test-dd to test it
+# before then.
+test-dd:
+        echo
+        echo Testing installed dynamic shared library in $(DL).
+        $(CC) -I$(DI) -I$(ZLIBINC) \
+           `$(BINPATH)/$(LIBNAME)-config --cflags` pngtest.c \
+           -o pngtestd `$(BINPATH)/$(LIBNAME)-config --ldflags` \
+           -L$(DL) -L$(ZLIBLIB) -R$(ZLIBLIB) -R$(DL)
+        ./pngtestd pngtest.png
+test-installed:
+        echo
+        echo Testing installed dynamic shared library.
+        $(CC) -I$(ZLIBINC) \
+           `$(BINPATH)/$(LIBNAME)-config --cflags` pngtest.c \
+           -o pngtesti `$(BINPATH)/$(LIBNAME)-config --ldflags` \
+           -L$(ZLIBLIB) -R$(ZLIBLIB)
+        ./pngtesti pngtest.png
+clean:
+        $(RM_F) *.o libpng.a pngtest pngtesti pngout.png \
+        libpng-config $(LIBSO) $(LIBSOMAJ)* \
+        libpng.pc pnglibconf.h
+DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
+writelock:
+        chmod a-w *.[ch35] $(DOCS) scripts/*
+# DO NOT DELETE THIS LINE -- make depend depends on it.
+png.o png.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngerror.o pngerror.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrio.o pngrio.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwio.o pngwio.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngmem.o pngmem.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngset.o pngset.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngget.o pngget.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngread.o pngread.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrtran.o pngrtran.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrutil.o pngrutil.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtrans.o pngtrans.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwrite.o pngwrite.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwtran.o pngwtran.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwutil.o pngwutil.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngpread.o pngpread.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtest.o: png.h pngconf.h pnglibconf.h
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.solaris-x86 b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.solaris-x86
new file mode 100644
index 0000000..4a43e53
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.solaris-x86
@@ -0,0 +1,236 @@
+# makefile for libpng on Solaris 2.x with gcc
+# Copyright (C) 2004, 2006-2008, 2010-2011 Glenn Randers-Pehrson
+# Contributed by William L. Sebok, based on makefile.linux
+# Copyright (C) 1998 Greg Roelofs
+# Copyright (C) 1996, 1997 Andreas Dilger
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+# Library name:
+LIBNAME = libpng15
+PNGMAJ = 15
+# Shared library names:
+LIBSO=$(LIBNAME).so
+LIBSOMAJ=$(LIBNAME).so.$(PNGMAJ)
+LIBSOREL=$(LIBSOMAJ).$(RELEASE)
+OLDSO=libpng.so
+# Utilities:
+AR_RC=ar rc
+CC=gcc
+MKDIR_P=mkdir -p
+LN_SF=ln -f -s
+RANLIB=echo
+RM_F=/bin/rm -f
+# Where make install puts libpng.a, libpng15.so*, and png.h
+prefix=/usr/local
+exec_prefix=$(prefix)
+# Where the zlib library and include files are located
+# Changing these to ../zlib poses a security risk.  If you want
+# to have zlib in an adjacent directory, specify the full path instead of "..".
+#ZLIBLIB=../zlib
+#ZLIBINC=../zlib
+ZLIBLIB=/usr/local/lib
+ZLIBINC=/usr/local/include
+WARNMORE=-Wwrite-strings -Wpointer-arith -Wshadow \
+        -Wmissing-declarations -Wtraditional -Wcast-align \
+        -Wstrict-prototypes -Wmissing-prototypes #-Wconversion
+CFLAGS=-I$(ZLIBINC) -W -Wall -O \
+        # $(WARNMORE) -g -DPNG_DEBUG=5
+LDFLAGS=-L. -R. -L$(ZLIBLIB) -R$(ZLIBLIB) -lpng15 -lz -lm
+INCPATH=$(prefix)/include
+LIBPATH=$(exec_prefix)/lib
+MANPATH=$(prefix)/man
+BINPATH=$(exec_prefix)/bin
+# override DESTDIR= on the make install command line to easily support
+# installing into a temporary location.  Example:
+#
+#    make install DESTDIR=/tmp/build/libpng
+#
+# If you're going to install into a temporary location
+# via DESTDIR, $(DESTDIR)$(prefix) must already exist before
+# you execute make install.
+DESTDIR=
+DB=$(DESTDIR)$(BINPATH)
+DI=$(DESTDIR)$(INCPATH)
+DL=$(DESTDIR)$(LIBPATH)
+DM=$(DESTDIR)$(MANPATH)
+OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
+        pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
+        pngwtran.o pngmem.o pngerror.o pngpread.o
+OBJSDLL = $(OBJS:.o=.pic.o)
+.SUFFIXES:      .c .o .pic.o
+.c.pic.o:
+        $(CC) -c $(CFLAGS) -fPIC -o $@ $*.c
+all: libpng.a $(LIBSO) pngtest libpng.pc libpng-config
+# see scripts/pnglibconf.mak for more options
+pnglibconf.h: scripts/pnglibconf.h.prebuilt
+        cp scripts/pnglibconf.h.prebuilt $@
+libpng.a: $(OBJS)
+        $(AR_RC) $@ $(OBJS)
+        $(RANLIB) $@
+libpng.pc:
+        cat scripts/libpng.pc.in | sed -e s!@prefix@!$(prefix)! \
+        -e s!@exec_prefix@!$(exec_prefix)! \
+        -e s!@libdir@!$(LIBPATH)! \
+        -e s!@includedir@!$(INCPATH)! \
+        -e s!-lpng15!-lpng15\ -lz\ -lm! > libpng.pc
+libpng-config:
+        ( cat scripts/libpng-config-head.in; \
+        echo prefix=\"$(prefix)\"; \
+        echo I_opts=\"-I$(INCPATH)/$(LIBNAME)\"; \
+        echo cppflags=\""; \
+        echo L_opts=\"-L$(LIBPATH)\"; \
+        echo R_opts=\"-R$(LIBPATH)\"; \
+        echo libs=\"-lpng15 -lz -lm\"; \
+        cat scripts/libpng-config-body.in ) > libpng-config
+        chmod +x libpng-config
+$(LIBSO): $(LIBSOMAJ)
+        $(LN_SF) $(LIBSOMAJ) $(LIBSO)
+$(LIBSOMAJ): $(OBJSDLL)
+        @case "`type ld`" in *ucb*) \
+        echo; \
+        echo '## WARNING:'; \
+        echo '## The commands "CC" and "LD" must NOT refer to /usr/ucb/cc'; \
+        echo '## and /usr/ucb/ld.  If they do, you need to adjust your PATH'; \
+        echo '## environment variable to put /usr/ccs/bin ahead of /usr/ucb.'; \
+        echo '## The environment variable LD_LIBRARY_PATH should not be set'; \
+        echo '## at all.  If it is, things are likely to break because of'; \
+        echo '## the libucb dependency that is created.'; \
+        echo; \
+        ;; \
+        esac
+        $(LD) -G -h $(LIBSOMAJ) \
+         -o $(LIBSOMAJ) $(OBJSDLL)
+pngtest: pngtest.o $(LIBSO)
+        $(CC) -o pngtest $(CFLAGS) pngtest.o $(LDFLAGS)
+test: pngtest
+        ./pngtest
+install-headers: png.h pngconf.h pnglibconf.h
+        -@if [ ! -d $(DI) ]; then $(MKDIR_P) $(DI); fi
+        -@if [ ! -d $(DI)/$(LIBNAME) ]; then $(MKDIR_P) $(DI)/$(LIBNAME); fi
+        cp png.h pngconf.h pnglibconf.h $(DI)/$(LIBNAME)
+        chmod 644 $(DI)/$(LIBNAME)/png.h $(DI)/$(LIBNAME)/pngconf.h $(DI)/$(LIBNAME)/pnglibconf.h
+        -@$(RM_F) $(DI)/png.h $(DI)/pngconf.h $(DI)/pnglibconf.h
+        -@$(RM_F) $(DI)/libpng
+        (cd $(DI); $(LN_SF) $(LIBNAME) libpng; $(LN_SF) $(LIBNAME)/* .)
+install-static: install-headers libpng.a
+        -@if [ ! -d $(DL) ]; then $(MKDIR_P) $(DL); fi
+        cp libpng.a $(DL)/$(LIBNAME).a
+        chmod 644 $(DL)/$(LIBNAME).a
+        -@$(RM_F) $(DL)/libpng.a
+        (cd $(DL); $(LN_SF) $(LIBNAME).a libpng.a)
+install-shared: install-headers $(LIBSOMAJ) libpng.pc
+        -@if [ ! -d $(DL) ]; then $(MKDIR_P) $(DL); fi
+        -@$(RM_F) $(DL)/$(LIBSO)
+        -@$(RM_F) $(DL)/$(LIBSOREL)
+        -@$(RM_F) $(DL)/$(OLDSO)
+        cp $(LIBSOMAJ) $(DL)/$(LIBSOREL)
+        chmod 755 $(DL)/$(LIBSOREL)
+        (cd $(DL); \
+        $(LN_SF) $(LIBSOREL) $(LIBSO); \
+        $(LN_SF) $(LIBSO) $(OLDSO))
+        -@if [ ! -d $(DL)/pkgconfig ]; then $(MKDIR_P) $(DL)/pkgconfig; fi
+        -@$(RM_F) $(DL)/pkgconfig/$(LIBNAME).pc
+        -@$(RM_F) $(DL)/pkgconfig/libpng.pc
+        cp libpng.pc $(DL)/pkgconfig/$(LIBNAME).pc
+        chmod 644 $(DL)/pkgconfig/$(LIBNAME).pc
+        (cd $(DL)/pkgconfig; $(LN_SF) $(LIBNAME).pc libpng.pc)
+install-man: libpng.3 libpngpf.3 png.5
+        -@if [ ! -d $(DM) ]; then $(MKDIR_P) $(DM); fi
+        -@if [ ! -d $(DM)/man3 ]; then $(MKDIR_P) $(DM)/man3; fi
+        -@$(RM_F) $(DM)/man3/libpng.3
+        -@$(RM_F) $(DM)/man3/libpngpf.3
+        cp libpng.3 $(DM)/man3
+        cp libpngpf.3 $(DM)/man3
+        -@if [ ! -d $(DM)/man5 ]; then $(MKDIR_P) $(DM)/man5; fi
+        -@$(RM_F) $(DM)/man5/png.5
+        cp png.5 $(DM)/man5
+install-config: libpng-config
+        -@if [ ! -d $(DB) ]; then $(MKDIR_P) $(DB); fi
+        -@$(RM_F) $(DB)/libpng-config
+        -@$(RM_F) $(DB)/$(LIBNAME)-config
+        cp libpng-config $(DB)/$(LIBNAME)-config
+        chmod 755 $(DB)/$(LIBNAME)-config
+        (cd $(DB); $(LN_SF) $(LIBNAME)-config libpng-config)
+install: install-static install-shared install-man install-config
+# If you installed in $(DESTDIR), test-installed won't work until you
+# move the library to its final location.  Use test-dd to test it
+# before then.
+test-dd:
+        echo
+        echo Testing installed dynamic shared library in $(DL).
+        $(CC) -I$(DI) -I$(ZLIBINC) \
+           `$(BINPATH)/$(LIBNAME)-config --cflags` pngtest.c \
+           -o pngtestd `$(BINPATH)/$(LIBNAME)-config --ldflags` \
+           -L$(DL) -L$(ZLIBLIB) -R$(ZLIBLIB) -R$(DL)
+        ./pngtestd pngtest.png
+test-installed:
+        echo
+        echo Testing installed dynamic shared library.
+        $(CC) -I$(ZLIBINC) \
+           `$(BINPATH)/$(LIBNAME)-config --cflags` pngtest.c \
+           -o pngtesti `$(BINPATH)/$(LIBNAME)-config --ldflags` \
+           -L$(ZLIBLIB) -R$(ZLIBLIB)
+        ./pngtesti pngtest.png
+clean:
+        $(RM_F) *.o libpng.a pngtest pngtesti pngout.png \
+        libpng-config $(LIBSO) $(LIBSOMAJ)* \
+        libpng.pc pnglibconf.h
+DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
+writelock:
+        chmod a-w *.[ch35] $(DOCS) scripts/*
+# DO NOT DELETE THIS LINE -- make depend depends on it.
+png.o png.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngerror.o pngerror.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrio.o pngrio.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwio.o pngwio.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngmem.o pngmem.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngset.o pngset.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngget.o pngget.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngread.o pngread.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrtran.o pngrtran.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrutil.o pngrutil.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtrans.o pngtrans.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwrite.o pngwrite.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwtran.o pngwtran.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwutil.o pngwutil.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngpread.o pngpread.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtest.o: png.h pngconf.h pnglibconf.h
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.std b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.std
new file mode 100644
index 0000000..d394f96
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.std
@@ -0,0 +1,123 @@
+# makefile for libpng
+# Copyright (C) 2002, 2006 Glenn Randers-Pehrson
+# Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
+#
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+# where make install puts libpng.a and png.h
+prefix=/usr/local
+INCPATH=$(prefix)/include
+LIBPATH=$(prefix)/lib
+# override DESTDIR= on the make install command line to easily support
+# installing into a temporary location.  Example:
+#
+#    make install DESTDIR=/tmp/build/libpng
+#
+# If you're going to install into a temporary location
+# via DESTDIR, $(DESTDIR)$(prefix) must already exist before
+# you execute make install.
+DESTDIR=
+# Where the zlib library and include files are located
+#ZLIBLIB=/usr/local/lib
+#ZLIBINC=/usr/local/include
+ZLIBLIB=../zlib
+ZLIBINC=../zlib
+CC=cc
+AR_RC=ar rc
+MKDIR_P=mkdir
+LN_SF=ln -sf
+RANLIB=ranlib
+RM_F=rm -f
+AWK = awk
+SED = sed
+CPP = $(CC) -E
+ECHO = echo
+DFNFLAGS = # DFNFLAGS contains -D options to use in the libpng build
+CFLAGS=-I$(ZLIBINC) -O # -g -DPNG_DEBUG=5
+LDFLAGS=-L. -L$(ZLIBLIB) -lpng -lz -lm
+OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
+        pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
+        pngwtran.o pngmem.o pngerror.o pngpread.o
+all: libpng.a pngtest
+# The standard pnglibconf.h exists as scripts/pnglibconf.h.prebuilt,
+# copy this if the following doesn't work.
+pnglibconf.dfn: scripts/pnglibconf.dfa scripts/options.awk pngconf.h
+        $(RM_F) $@ dfn?.out
+        $(AWK) -f scripts/options.awk out=dfn1.out version=search pngconf.h\
+            scripts/pnglibconf.dfa $(DFA_XTRA) 1>&2
+        $(AWK) -f scripts/options.awk out=dfn2.out dfn1.out 1>&2
+        cp dfn2.out $@
+        $(RM_F) dfn?.out
+pnglibconf.h: pnglibconf.dfn
+        $(RM_F) $@ dfn.c dfn?.out
+        $(ECHO) '#include "pnglibconf.dfn"' >dfn.c
+        $(CPP) $(DFNFLAGS) dfn.c >dfn1.out
+        $(SED) -n -e 's|^.*PNG_DEFN_MAGIC *-\(.*\)- *PNG_DEFN_END.*$$|\1|p'\
+            dfn1.out >dfn2.out
+        $(SED) -e 's| *PNG_JOIN *||g' -e 's| *$$||' dfn2.out >dfn3.out
+        cp dfn3.out $@
+        $(RM_F) dfn.c dfn?.out
+libpng.a: $(OBJS)
+        $(AR_RC) $@  $(OBJS)
+        $(RANLIB) $@
+pngtest: pngtest.o libpng.a
+        $(CC) -o pngtest $(CFLAGS) pngtest.o $(LDFLAGS)
+test: pngtest
+        ./pngtest
+install: libpng.a pnglibconf.h
+        -@$(MKDIR_P) $(DESTDIR)$(INCPATH)
+        -@$(MKDIR_P) $(DESTDIR)$(INCPATH)/libpng
+        -@$(MKDIR_P) $(DESTDIR)$(LIBPATH)
+        -@$(RM_F) $(DESTDIR)$(INCPATH)/png.h
+        -@$(RM_F) $(DESTDIR)$(INCPATH)/pngconf.h
+        -@$(RM_F) $(DESTDIR)$(INCPATH)/pnglibconf.h
+        cp png.h $(DESTDIR)$(INCPATH)/libpng
+        cp pngconf.h $(DESTDIR)$(INCPATH)/libpng
+        cp pnglibconf.h $(DESTDIR)$(INCPATH)/libpng
+        chmod 644 $(DESTDIR)$(INCPATH)/libpng/png.h
+        chmod 644 $(DESTDIR)$(INCPATH)/libpng/pngconf.h
+        chmod 644 $(DESTDIR)$(INCPATH)/libpng/pnglibconf.h
+        (cd $(DESTDIR)$(INCPATH); ln -f -s libpng/* .)
+        cp libpng.a $(DESTDIR)$(LIBPATH)
+        chmod 644 $(DESTDIR)$(LIBPATH)/libpng.a
+clean:
+        $(RM_F) *.o libpng.a pngtest pngout.png pnglibconf.* dfn.c dfn?.out
+DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
+writelock:
+        chmod a-w *.[ch35] $(DOCS) scripts/*
+# DO NOT DELETE THIS LINE -- make depend depends on it.
+png.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngerror.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrio.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwio.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngmem.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngset.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngget.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngread.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrtran.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrutil.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtrans.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwrite.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwtran.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwutil.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngpread.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtest.o: png.h pngconf.h pnglibconf.h
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.sunos b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.sunos
new file mode 100644
index 0000000..52cd4d4
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.sunos
@@ -0,0 +1,107 @@
+# makefile for libpng
+# Copyright (C) 2002, 2006 Glenn Randers-Pehrson
+# Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
+#
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+# where make install puts libpng.a and png.h
+prefix=/usr/local
+INCPATH=$(prefix)/include
+LIBPATH=$(prefix)/lib
+# override DESTDIR= on the make install command line to easily support
+# installing into a temporary location.  Example:
+#
+#    make install DESTDIR=/tmp/build/libpng
+#
+# If you're going to install into a temporary location
+# via DESTDIR, $(DESTDIR)$(prefix) must already exist before
+# you execute make install.
+DESTDIR=
+# Where the zlib library and include files are located
+#ZLIBLIB=/usr/local/lib
+#ZLIBINC=/usr/local/include
+ZLIBLIB=../zlib
+ZLIBINC=../zlib
+WARNMORE=-Wwrite-strings -Wpointer-arith -Wshadow -Wconversion \
+        -Wmissing-declarations -Wtraditional -Wcast-align \
+        -Wstrict-prototypes -Wmissing-prototypes
+CC=gcc
+AR_RC=ar rc
+MKDIR_P=mkdir -p
+LN_SF=ln -f -s
+RANLIB=ranlib
+RM_F=/bin/rm -f
+CFLAGS=-I$(ZLIBINC) -O # $(WARNMORE) -DPNG_DEBUG=5
+LDFLAGS=-L. -L$(ZLIBLIB) -lpng -lz -lm
+OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
+        pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
+        pngwtran.o pngmem.o pngerror.o pngpread.o
+all: libpng.a pngtest
+# see scripts/pnglibconf.mak for more options
+pnglibconf.h: scripts/pnglibconf.h.prebuilt
+        cp scripts/pnglibconf.h.prebuilt $@
+libpng.a: $(OBJS)
+        $(AR_RC) $@  $(OBJS)
+        $(RANLIB) $@
+pngtest: pngtest.o libpng.a
+        $(CC) -o pngtest $(CFLAGS) pngtest.o $(LDFLAGS)
+test: pngtest
+        ./pngtest
+install: libpng.a
+        -@$(MKDIR_P) $(DESTDIR)$(INCPATH)
+        -@$(MKDIR_P) $(DESTDIR)$(INCPATH)/libpng
+        -@$(MKDIR_P) $(DESTDIR)$(LIBPATH)
+        -@$(RM_F) $(DESTDIR)$(INCPATH)/png.h
+        -@$(RM_F) $(DESTDIR)$(INCPATH)/pngconf.h
+        -@$(RM_F) $(DESTDIR)$(INCPATH)/pnglibconf.h
+        cp png.h $(DESTDIR)$(INCPATH)/libpng
+        cp pngconf.h $(DESTDIR)$(INCPATH)/libpng
+        cp pnglibconf.h $(DESTDIR)$(INCPATH)/libpng
+        chmod 644 $(DESTDIR)$(INCPATH)/libpng/png.h
+        chmod 644 $(DESTDIR)$(INCPATH)/libpng/pngconf.h
+        chmod 644 $(DESTDIR)$(INCPATH)/libpng/pnglibconf.h
+        (cd $(DESTDIR)$(INCPATH); $(LN_SF) libpng/* .)
+        cp libpng.a $(DESTDIR)$(LIBPATH)
+        chmod 644 $(DESTDIR)$(LIBPATH)/libpng.a
+clean:
+        $(RM_F) *.o libpng.a pngtest pngout.png pnglibconf.h
+DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
+writelock:
+        chmod a-w *.[ch35] $(DOCS) scripts/*
+# DO NOT DELETE THIS LINE -- make depend depends on it.
+png.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngerror.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrio.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwio.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngmem.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngset.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngget.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngread.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrtran.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngrutil.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtrans.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwrite.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwtran.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngwutil.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngpread.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+pngtest.o: png.h pngconf.h pnglibconf.h
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.tc3 b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.tc3
new file mode 100644
index 0000000..311acfb
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.tc3
@@ -0,0 +1,93 @@
+# Makefile for libpng
+# TurboC/C++ (Note: All modules are compiled in C mode)
+# To use, do "make -fmakefile.tc3"
+# ----- Turbo C 3.00 (can be modified to work with earlier versions) -----
+MODEL=l
+CFLAGS=-O2 -Z -m$(MODEL) -I..\zlib
+#CFLAGS=-D_NO_PROTO -O2 -Z -m$(MODEL) -I..\zlib  # Turbo C older than 3.00
+CC=tcc
+LD=tcc
+LIB=tlib
+LDFLAGS=-m$(MODEL) -L..\zlib
+O=.obj
+E=.exe
+# variables
+OBJS1 = png$(O) pngset$(O) pngget$(O) pngrutil$(O) pngtrans$(O) pngwutil$(O)
+OBJS2 = pngmem$(O) pngpread$(O) pngread$(O) pngerror$(O) pngwrite$(O)
+OBJS3 = pngrtran$(O) pngwtran$(O) pngrio$(O) pngwio$(O)
+OBJSL1 = +png$(O) +pngset$(O) +pngget$(O) +pngrutil$(O) +pngtrans$(O)
+OBJSL2 = +pngwutil$(O) +pngmem$(O) +pngpread$(O) +pngread$(O) +pngerror$(O)
+OBJSL3 = +pngwrite$(O) +pngrtran$(O) +pngwtran$(O) +pngrio$(O) +pngwio$(O)
+all: libpng$(MODEL).lib pngtest$(E)
+# see scripts/pnglibconf.mak for more options
+pnglibconf.h: scripts/pnglibconf.h.prebuilt
+        cp scripts/pnglibconf.h.prebuilt $@
+pngtest: pngtest$(E)
+test: pngtest$(E)
+        pngtest$(E)
+png$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+                  $(CC) -c $(CFLAGS) $*.c
+pngset$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+                  $(CC) -c $(CFLAGS) $*.c
+pngget$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+                  $(CC) -c $(CFLAGS) $*.c
+pngread$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+                  $(CC) -c $(CFLAGS) $*.c
+pngpread$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+                  $(CC) -c $(CFLAGS) $*.c
+pngrtran$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+                  $(CC) -c $(CFLAGS) $*.c
+pngrutil$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+                  $(CC) -c $(CFLAGS) $*.c
+pngerror$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) -c $(CFLAGS) $*.c
+pngmem$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) -c $(CFLAGS) $*.c
+pngrio$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) -c $(CFLAGS) $*.c
+pngwio$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) -c $(CFLAGS) $*.c
+pngtest$(O): png.h pngconf.h pnglibconf.h
+        $(CC) -c $(CFLAGS) $*.c
+pngtrans$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) -c $(CFLAGS) $*.c
+pngwrite$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) -c $(CFLAGS) $*.c
+pngwtran$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) -c $(CFLAGS) $*.c
+pngwutil$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) -c $(CFLAGS) $*.c
+libpng$(MODEL).lib: $(OBJS1) $(OBJS2) $(OBJS3)
+        $(LIB) libpng$(MODEL) +$(OBJSL1)
+        $(LIB) libpng$(MODEL) +$(OBJSL2)
+        $(LIB) libpng$(MODEL) +$(OBJSL3)
+pngtest$(E): pngtest$(O) libpng$(MODEL).lib
+        $(LD) $(LDFLAGS) pngtest.obj libpng$(MODEL).lib zlib_$(MODEL).lib
+# End of makefile for libpng
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.vcwin32 b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.vcwin32
new file mode 100644
index 0000000..bdcc508
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makefile.vcwin32
@@ -0,0 +1,108 @@
+# makefile for libpng
+# Copyright (C) 1998 Tim Wegner
+# Copyright (C) 2006,2009,2011 Glenn Randers-Pehrson
+#
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+#
+# Assumes that zlib.lib, zconf.h, and zlib.h have been copied to ..\zlib
+# To use, do "nmake /f scripts\makefile.vcwin32"
+# -------- Microsoft Visual C++ 2.0 and later, no assembler code --------
+# Compiler, linker, librarian, and other tools
+CC = cl
+LD = link
+AR = lib
+CFLAGS  = -nologo -D_CRT_SECURE_NO_DEPRECATE -MD -O2 -W3 -I..\zlib
+LDFLAGS = -nologo
+ARFLAGS = -nologo
+RM = del
+# File extensions
+O=.obj
+#uncomment next to put error messages in a file
+#ERRFILE= >> pngerrs.log
+# Variables
+OBJS1 = png$(O) pngerror$(O) pngget$(O) pngmem$(O) pngpread$(O)
+OBJS2 = pngread$(O) pngrio$(O) pngrtran$(O) pngrutil$(O) pngset$(O)
+OBJS3 = pngtrans$(O) pngwio$(O) pngwrite$(O) pngwtran$(O) pngwutil$(O)
+OBJS  = $(OBJS1) $(OBJS2) $(OBJS3)
+# Targets
+all: libpng.lib
+# see scripts/pnglibconf.mak for more options
+pnglibconf.h: scripts\pnglibconf.h.prebuilt
+       copy scripts\pnglibconf.h.prebuilt $@
+png$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+pngset$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+pngget$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+pngread$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+pngpread$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+pngrtran$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+pngrutil$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+pngerror$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+pngmem$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+pngrio$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+pngwio$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+pngtrans$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+pngwrite$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+pngwtran$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+pngwutil$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+libpng.lib: $(OBJS)
+        -$(RM) $@
+        $(AR) $(ARFLAGS) -out:$@ $(OBJS) $(ERRFILE)
+pngtest$(O): png.h pngconf.h pnglibconf.h
+        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+pngtest.exe: pngtest$(O) libpng.lib
+        $(LD) $(LDFLAGS) -out:$@ pngtest$(O) libpng.lib ..\zlib\zlib.lib $(ERRFILE)
+test: pngtest.exe
+        pngtest
+clean:
+        -$(RM) *$(O)
+        -$(RM) libpng.lib
+        -$(RM) pnglibconf.h
+        -$(RM) pngtest.exe
+        -$(RM) pngout.png
+# End of makefile for libpng
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makevms.com b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makevms.com
new file mode 100644
index 0000000..6563684
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/makevms.com
@@ -0,0 +1,142 @@
+$! make libpng under VMS
+$!
+$!
+$! Check for MMK/MMS
+$!
+$! This procedure accepts one parameter (contrib), which causes it to build
+$! the programs from the contrib directory instead of libpng.
+$!
+$ p1 = f$edit(p1,"UPCASE")
+$ if p1 .eqs. "CONTRIB"
+$ then
+$   set def [.contrib.gregbook]
+$   @makevms
+$   set def [-.pngminus]
+$   @makevms
+$   set def [--]
+$   exit
+$ endif
+$ Make = ""
+$ If F$Search ("Sys$System:MMS.EXE") .nes. "" Then Make = "MMS"
+$ If F$Type (MMK) .eqs. "STRING" Then Make = "MMK"
+$!
+$! Look for the compiler used
+$!
+$ zlibsrc = "[-.zlib]"
+$ ccopt="/include=''zlibsrc'"
+$ if f$getsyi("HW_MODEL").ge.1024
+$ then
+$  ccopt = "/prefix=all"+ccopt
+$  comp  = "__decc__=1"
+$  if f$trnlnm("SYS").eqs."" then define sys sys$library:
+$ else
+$  if f$search("SYS$SYSTEM:DECC$COMPILER.EXE").eqs.""
+$   then
+$    if f$trnlnm("SYS").eqs."" then define sys sys$library:
+$    if f$search("SYS$SYSTEM:VAXC.EXE").eqs.""
+$     then
+$      comp  = "__gcc__=1"
+$      CC :== GCC
+$     else
+$      comp = "__vaxc__=1"
+$     endif
+$   else
+$    if f$trnlnm("SYS").eqs."" then define sys decc$library_include:
+$    ccopt = "/decc/prefix=all"+ccopt
+$    comp  = "__decc__=1"
+$  endif
+$ endif
+$!
+$! Build the thing plain or with mms/mmk
+$!
+$ write sys$output "Compiling Libpng sources ..."
+$ if make.eqs.""
+$  then
+$   dele pngtest.obj;*
+$   CALL MAKE png.OBJ "cc ''CCOPT' png" -
+        png.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+$   CALL MAKE pngset.OBJ "cc ''CCOPT' pngset" -
+        pngset.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+$   CALL MAKE pngget.OBJ "cc ''CCOPT' pngget" -
+        pngget.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+$   CALL MAKE pngread.OBJ "cc ''CCOPT' pngread" -
+        pngread.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+$   CALL MAKE pngpread.OBJ "cc ''CCOPT' pngpread" -
+        pngpread.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+$   CALL MAKE pngrtran.OBJ "cc ''CCOPT' pngrtran" -
+        pngrtran.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+$   CALL MAKE pngrutil.OBJ "cc ''CCOPT' pngrutil" -
+        pngrutil.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+$   CALL MAKE pngerror.OBJ "cc ''CCOPT' pngerror" -
+        pngerror.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+$   CALL MAKE pngmem.OBJ "cc ''CCOPT' pngmem" -
+        pngmem.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+$   CALL MAKE pngrio.OBJ "cc ''CCOPT' pngrio" -
+        pngrio.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+$   CALL MAKE pngwio.OBJ "cc ''CCOPT' pngwio" -
+        pngwio.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+$   CALL MAKE pngtrans.OBJ "cc ''CCOPT' pngtrans" -
+        pngtrans.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+$   CALL MAKE pngwrite.OBJ "cc ''CCOPT' pngwrite" -
+        pngwrite.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+$   CALL MAKE pngwtran.OBJ "cc ''CCOPT' pngwtran" -
+        pngwtran.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+$   CALL MAKE pngwutil.OBJ "cc ''CCOPT' pngwutil" -
+        pngwutil.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
+$   write sys$output "Building Libpng ..."
+$   CALL MAKE libpng.OLB "lib/crea libpng.olb *.obj" *.OBJ
+$   write sys$output "Building pngtest..."
+$   CALL MAKE pngtest.OBJ "cc ''CCOPT' pngtest" -
+        pngtest.c png.h pngconf.h pnglibconf.h
+$   call make pngtest.exe -
+        "LINK pngtest,libpng.olb/lib,''zlibsrc'libz.olb/lib" -
+        pngtest.obj libpng.olb
+$   write sys$output "Testing Libpng..."
+$   run pngtest
+$  else
+$   if f$search("DESCRIP.MMS") .eqs. "" then copy/nolog [.SCRIPTS]DESCRIP.MMS []
+$   'make'/macro=('comp',zlibsrc='zlibsrc')
+$  endif
+$ write sys$output "Libpng build completed"
+$ exit
+$!
+$!
+$MAKE: SUBROUTINE   !SUBROUTINE TO CHECK DEPENDENCIES
+$ V = 'F$Verify(0)
+$! P1 = What we are trying to make
+$! P2 = Command to make it
+$! P3 - P8  What it depends on
+$
+$ If F$Search(P1) .Eqs. "" Then Goto Makeit
+$ Time = F$CvTime(F$File(P1,"RDT"))
+$arg=3
+$Loop:
+$       Argument = P'arg
+$       If Argument .Eqs. "" Then Goto Exit
+$       El=0
+$Loop2:
+$       File = F$Element(El," ",Argument)
+$       If File .Eqs. " " Then Goto Endl
+$       AFile = ""
+$Loop3:
+$       OFile = AFile
+$       AFile = F$Search(File)
+$       If AFile .Eqs. "" .Or. AFile .Eqs. OFile Then Goto NextEl
+$       If F$CvTime(F$File(AFile,"RDT")) .Ges. Time Then Goto Makeit
+$       Goto Loop3
+$NextEL:
+$       El = El + 1
+$       Goto Loop2
+$EndL:
+$ arg=arg+1
+$ If arg .Le. 8 Then Goto Loop
+$ Goto Exit
+$
+$Makeit:
+$ VV=F$VERIFY(0)
+$ write sys$output P2
+$ 'P2
+$ VV='F$Verify(VV)
+$Exit:
+$ If V Then Set Verify
+$ENDSUBROUTINE
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/options.awk b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/options.awk
new file mode 100644
index 0000000..29ea31d
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/options.awk
@@ -0,0 +1,777 @@
+#!/bin/awk -f
+# scripts/options.awk - library build configuration control
+#
+# last changed in libpng version 1.5.7 - December 15, 2011
+#
+# Copyright (c) 1998-2011 Glenn Randers-Pehrson
+#
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+# The output of this script is written to the file given by
+# the variable 'out'.  The script is run twice, once with
+# an intermediate output file, 'options.tmp' then again on
+# that file to produce the final output:
+#
+#  awk -f scripts/options.awk out=options.tmp scripts/options.dfa 1>&2
+#  awk -f scripts/options.awk out=options.dfn options.tmp 1>&2
+#
+# Some options may be specified on the command line:
+#
+#  deb=1            Causes debugging to be output
+#  logunsupported=1 Causes all options to be recorded in the output
+#  everything=off   Causes all options to be disabled by default
+#  everything=on    Causes all options to be enabled by default
+#
+# If awk fails on your platform, try nawk instead.
+#
+# These options may also be specified in the original input file (and
+# are copied to the preprocessed file).
+BEGIN{
+   out="/dev/null"              # intermediate, preprocessed, file
+   pre=-1                       # preprocess (first line)
+   version="libpng version unknown" # version information
+   version_file=""              # where to find the version
+   err=0                        # in-line exit sets this
+   start="PNG_DEFN_MAGIC-"      # Arbitrary start
+   end="-PNG_DEFN_END"          # Arbitrary end
+   ct="PNG_JOIN"                # Join two tokens
+   cx= "/" ct "*"               # Open C comment for output file
+   comment=start cx             # Comment start
+   cend="*/" end                # Comment end
+   def=start "#define PNG_" ct  # Arbitrary define
+   sup=ct "_SUPPORTED" end      # end supported option
+   und=comment "#undef PNG_" ct # Unsupported option
+   une=ct "_SUPPORTED" cend     # end unsupported option
+   error=start "ERROR:"         # error message
+   # Variables
+   deb=0                        # debug - set on command line
+   everything=""                # do not override defaults
+   logunsupported=0             # write unsupported options too
+   # Precreate arrays
+   option[""] = ""    # list of all options: default enabled/disabled
+   done[""] = 1       # marks option as having been output
+   requires[""] = ""  # requires by option
+   iffs[""] = ""      # if by option
+   enabledby[""] = "" # options that enable it by option
+   setting[""] = ""   # requires by setting
+   defaults[""] = ""  # used for a defaulted value
+   doneset[""] = 1    # marks setting as having been output
+   r[""] = ""         # Temporary array
+   # For decorating the output file
+   protect = ""
+}
+# The output file must be specified before any input:
+out == "/dev/null" {
+   print "out=output.file must be given on the command line"
+   err = 1
+   exit 1
+}
+# The very first line indicates whether we are reading pre-processed
+# input or not, this must come *first* because 'PREPROCESSED' needs
+# to be the very first line in the temporary file.
+pre == -1{
+   if ($0 == "PREPROCESSED") {
+      pre = 0
+      next
+   } else {
+      pre = 1
+      print "PREPROCESSED" >out
+      # And fall through to continue processing
+   }
+}
+# While pre-processing if version is set to "search" look for a version string
+# in the following file.
+pre && version == "search" && version_file == ""{
+   version_file = FILENAME
+}
+pre && version == "search" && version_file != FILENAME{
+   print "version string not found in", version_file
+   err = 1
+   exit 1
+}
+pre && version == "search" && $0 ~ /^ \* libpng version/{
+   version = substr($0, 4)
+   print "version =", version >out
+   next
+}
+pre && FILENAME == version_file{
+   next
+}
+# variable=value
+#   Sets the given variable to the given value (the syntax is fairly
+#   free form, except for deb (you are expected to understand how to
+#   set the debug variable...)
+#
+#   This happens before the check on 'pre' below skips most of the
+#   rest of the actions, so the variable settings happen during
+#   preprocessing but are recorded in the END action too.  This
+#   allows them to be set on the command line too.
+$0 ~ /^[        ]*version[      ]*=/{
+   sub(/^[  ]*version[  ]*=[  ]*/, "")
+   version = $0
+   next
+}
+$0 ~ /^[        ]*everything[   =]*off[         ]*$/{
+   everything = "off"
+   next
+}
+$0 ~ /^[        ]*everything[   =]*on[  ]*$/{
+   everything = "on"
+   next
+}
+$0 ~ /^[        ]*logunsupported[       =]*0[   ]*$/{
+   logunsupported = 0
+   next
+}
+$0 ~ /^[        ]*logunsupported[       =]*1[   ]*$/{
+   logunsupported = 1
+   next
+}
+$1 == "deb" && $2 == "=" && NF == 3{
+   deb = $3
+   next
+}
+# Preprocessing - this just copies the input file with lines
+# that need preprocessing (just chunk at present) expanded
+# The bare "pre" instead of "pre != 0" crashes under Sunos awk
+pre && $1 != "chunk"{
+   print >out
+   next
+}
+# The first characters of the line determine how it is processed,
+# leading spaces are ignored.  In general tokens that are not
+# keywords are the names of options.  An option 'name' is
+# controlled by the definition of the corresponding macros:
+#
+#   PNG_name_SUPPORTED    The option is turned on
+#   PNG_NO_name
+#   PNG_NO_name_SUPPORTED If the first macro is not defined
+#                         either of these will turn the option off
+#
+# If none of these macros are defined the option is turned on, unless
+# the keyword 'off' is given in a line relating to the option.  The
+# keyword 'on' can also be given, but it will be ignored (since it is
+# the default.)
+#
+# In the syntax below a 'name' is indicated by "NAME", other macro
+# values are indicated by "MACRO", as with "NAME" the leading "PNG_"
+# is omitted, but in this case the "NO_" prefix and the "_SUPPORTED"
+# suffix are never used.
+#
+# Each line is introduced by a keyword - the first non-space characters
+# on the line.  A line starting with a '#' is a comment - it is totally
+# ignored.  Keywords are as follows, a NAME, is simply a macro name
+# without the leading PNG_, PNG_NO_ or the trailing _SUPPORTED.
+$1 ~ /^#/ || $0 ~ /^[   ]*$/{
+   next
+}
+# com <comment>
+#   The whole line is placed in the output file as a comment with
+#   the preceding 'com' removed
+$1 == "com"{
+   if (NF > 1) {
+      # sub(/^[         ]*com[  ]*/, "")
+      $1 = ""
+      print comment, $0, cend >out
+   } else
+      print start end >out
+   next
+}
+# version
+#   Inserts a version comment
+$1 == "version" && NF == 1{
+   if (version == "") {
+      print "ERROR: no version string set"
+      err = 1 # prevent END{} running
+      exit 1
+   }
+   print comment, version, cend >out
+   next
+}
+# file output input protect
+#   Informational: the official name of the input file (without
+#   make generated local directories), the official name of the
+#   output file and, if required, a name to use in a protection
+#   macro for the contents.
+$1 == "file" && NF >= 2{
+   print comment, $2, cend >out
+   print comment, "Machine generated file: DO NOT EDIT", cend >out
+   if (NF >= 3)
+      print comment, "Derived from:", $3, cend >out
+   protect = $4
+   if (protect != "") {
+      print start "#ifndef", protect end >out
+      print start "#define", protect end >out
+   }
+   next
+}
+# option NAME ( (requires|enables|if) NAME* | on | off | disabled )*
+#   Declares an option 'NAME' and describes its default setting (disabled)
+#   and its relationship to other options.  The option is disabled
+#   unless *all* the options listed after 'requires' are set and at
+#   least one of the options listed after 'if' is set.  If the
+#   option is set then it turns on all the options listed after 'enables'.
+#
+#   Note that "enables" takes priority over the required/if/disabled/off
+#   setting of the target option.
+#
+#   The definition file may list an option as 'disabled': off by default,
+#   otherwise the option is enabled: on by default.  A later (and it must
+#   be later) entry may turn an option on or off explicitly.
+$1 == "option" && NF >= 2{
+   onoff = option[$2]  # records current (and the default is "", enabled)
+   key = ""
+   for (i=3; i<=NF; ++i) {
+      if ($(i) == "on" || $(i) == "off" || $(i) == "disabled") {
+         key = ""
+         if (onoff != $(i)) {
+            # on or off can zap disabled or enabled:
+            if (onoff == "" || (onoff == "disabled" || onoff == "enabled") && ($(i) == "on" || $(i) == "off")) {
+               # It's easy to mis-spell the option when turning it
+               # on or off, so warn about it here:
+               if (onoff == "" && ($(i) == "on" || $(i) == "off")) {
+                  print $2 ": ERROR: turning unrecognized option", $(i)
+                  # For the moment error out - it is safer
+                  err = 1 # prevent END{} running
+                  exit 1
+               }
+               onoff = $(i)
+            } else {
+               # Print a message, otherwise the error
+               # below is incomprehensible
+               print $2 ": currently", onoff ": attempt to turn", $(i)
+               break
+            }
+         }
+      } else if ($(i) == "requires" || $(i) == "if" || $(i) == "enables") {
+         key = $(i)
+      } else if (key == "requires") {
+         requires[$2] = requires[$2] " " $(i)
+      } else if (key == "if") {
+         iffs[$2] = iffs[$2] " " $(i)
+      } else if (key == "enables") {
+         enabledby[$(i)] = enabledby[$(i)] " " $2
+      } else
+         break # bad line format
+   }
+   if (i > NF) {
+      # Set the option, defaulting to 'enabled'
+      if (onoff == "") onoff = "enabled"
+      option[$2] = onoff
+      next
+   }
+   # Else fall through to the error handler
+}
+# chunk NAME [requires OPT] [on|off|disabled]
+#   Expands to the 'option' settings appropriate to the reading and
+#   writing of an ancilliary PNG chunk 'NAME':
+#
+#   option READ_NAME requires READ_ANCILLARY_CHUNKS [READ_OPT]
+#   option READ_NAME enables NAME
+#   [option READ_NAME off]
+#   option WRITE_NAME requires WRITE_ANCILLARY_CHUNKS [WRITE_OPT]
+#   option WRITE_NAME enables NAME
+#   [option WRITE_NAME off]
+pre != 0 && $1 == "chunk" && NF >= 2{
+   # 'chunk' is handled on the first pass by writing appropriate
+   # 'option' lines into the intermediate file.
+   onoff = ""
+   reqread = ""
+   reqwrite = ""
+   i = 3 # indicates format error
+   if (NF > 2) {
+      # read the keywords/additional OPTS
+      req = 0
+      for (i=3; i<=NF; ++i) {
+         if ($(i) == "on" || $(i) == "off" || $(i) == "disabled") {
+            if (onoff != $(i)) {
+               if (onoff == "")
+                  onoff = $(i)
+               else
+                  break # on/off conflict
+            }
+         } else if ($(i) == "requires")
+            req = 1
+         else if (req != 1)
+            break # bad line: handled below
+         else {
+            reqread = reqread " READ_" $(i)
+            reqwrite = reqwrite " WRITE_" $(i)
+         }
+      }
+   }
+   if (i > NF) {
+      # Output new 'option' lines to the intermediate file (out)
+      print "option READ_" $2, "requires READ_ANCILLARY_CHUNKS" reqread, "enables", $2, onoff >out
+      print "option WRITE_" $2, "requires WRITE_ANCILLARY_CHUNKS" reqwrite, "enables", $2, onoff >out
+      next
+   }
+   # Else hit the error handler below - bad line format!
+}
+# setting MACRO ( requires MACRO* )* [ default VALUE ]
+#   Behaves in a similar way to 'option' without looking for NO_ or
+#   _SUPPORTED; the macro is enabled if it is defined so long as all
+#   the 'requires' macros are also defined.  The definitions may be
+#   empty, an error will be issued if the 'requires' macros are
+#   *not* defined.  If given the 'default' value is used if the
+#   macro is not defined.  The default value will be re-tokenised.
+#   (BTW: this is somewhat restrictive, it mainly exists for the
+#   support of non-standard configurations and numeric parameters,
+#   see the uses in scripts/options.dat
+$1 == "setting" && (NF == 2 || NF >= 3 && ($3 == "requires" || $3 == "default")){
+   reqs = ""
+   deflt = ""
+   isdef = 0
+   key = ""
+   for (i=3; i<=NF; ++i)
+      if ($(i) == "requires" || $(i) == "default") {
+         key = $(i)
+         if (key == "default") isdef = 1
+      } else if (key == "requires")
+         reqs = reqs " " $(i)
+      else if (key == "default")
+         deflt = deflt " " $(i)
+      else
+         break # Format error, handled below
+   setting[$2] = reqs
+   # NOTE: this overwrites a previous value silently
+   if (isdef && deflt == "")
+      deflt = " " # as a flag to force output
+   defaults[$2] = deflt
+   next
+}
+# The order of the dependency lines (option, chunk, setting) is irrelevant
+# - the 'enables', 'requires' and 'if' settings will be used to determine
+# the correct order in the output and the final values in pnglibconf.h are
+# not order dependent.  'requires' and 'if' entries take precedence over
+# 'enables' from other options; if an option requires another option it
+# won't be set regardless of any options that enable it unless the other
+# option is also enabled.
+#
+# Similarly 'enables' trumps a NO_ definition in CFLAGS or pngusr.h
+#
+# For simplicity cycles in the definitions are regarded as errors,
+# even if they are not ambiguous.
+# A given NAME can be specified in as many 'option' lines as required, the
+# definitions are additive.
+# For backwards compatibility equivalent macros may be listed thus:
+#
+# = [NO_]NAME MACRO
+#   Makes -DMACRO equivalent to -DPNG_NO_NAME or -DPNG_NAME_SUPPORTED
+#   as appropriate.
+#
+# The definition is injected into the C compiler input when encountered
+# in the second pass (so all these definitions appear *after* the @
+# lines!)
+#
+# 'NAME' is as above, but 'MACRO' is the full text of the equivalent
+# old, deprecated, macro.
+$1 == "=" && NF == 3{
+   print "#ifdef PNG_" $3 >out
+   if ($2 ~ /^NO_/)
+      print "#   define PNG_" $2 >out
+   else
+      print "#   define PNG_" $2 "_SUPPORTED" >out
+   print "#endif" >out
+   next
+}
+# Lines may be injected into the C compiler input by preceding them
+# with an "@" character.  The line is copied with just the leading
+# @ removed.
+$1 ~ /^@/{
+   # sub(/^[    ]*@/, "")
+   $1 = substr($1, 2)
+   print >out
+   next
+}
+# Check for unreognized lines, because of the preprocessing chunk
+# format errors will be detected on the first pass independent of
+# any other format errors.
+{
+   print "options.awk: bad line (" NR "):", $0
+   err = 1 # prevent END{} running
+   exit 1
+}
+# For checking purposes names that start with "ok_" or "fail_" are
+# not output to pnglibconf.h and must be either enabled or disabled
+# respectively for the build to succeed.  This allows interdependencies
+# between options of the form "at least one of" or "at most one of"
+# to be checked.  For example:
+#
+# option FLOATING_POINT enables ok_math
+# option FIXED_POINT enables ok_math
+#   This ensures that at least one of FLOATING_POINT and FIXED_POINT
+#   must be set for the build to succeed.
+#
+# option fail_math requires FLOATING_POINT FIXED_POINT
+#   This means the build will fail if *both* FLOATING_POINT and
+#   FIXED_POINT are set (this is an example; in fact both are allowed.)
+#
+# If all these options were given the build would require exactly one
+# of the names to be enabled.
+END{
+   # END{} gets run on an exit (a traditional awk feature)
+   if (err) exit 1
+   if (pre) {
+      # Record the final value of the variables
+      print "deb =", deb >out
+      if (everything != "") {
+         print "everything =", everything >out
+      }
+      print "logunsupported =", logunsupported >out
+      exit 0
+   }
+   # Do the 'setting' values first, the algorithm the standard
+   # tree walk (O(1)) done in an O(2) while/for loop; interations
+   # settings x depth, outputing the deepest required macros
+   # first.
+   print "" >out
+   print "/* SETTINGS */" >out
+   print comment, "settings", cend >out
+   finished = 0
+   while (!finished) {
+      finished = 1
+      movement = 0 # done nothing
+      for (i in setting) if (!doneset[i]) {
+         nreqs = split(setting[i], r)
+         if (nreqs > 0) {
+            for (j=1; j<=nreqs; ++j) if (!doneset[r[j]]) {
+               break
+            }
+            if (j<=nreqs) {
+               finished = 0
+               continue # try a different setting
+            }
+         }
+         # All the requirements have been processed, output
+         # this setting.
+         if (deb) print "setting", i
+         print "" >out
+         print "/* setting: ", i >out
+         print " *   requires:" setting[i] >out
+         print " *   default: ", defaults[i], "*/" >out
+         if (defaults[i] == "") { # no default, only check if defined
+            print "#ifdef PNG_" i >out
+         }
+         for (j=1; j<=nreqs; ++j) {
+            print "# ifndef PNG_" r[j] >out
+            print error, i, "requires", r[j] end >out
+            print "# endif" >out
+         }
+         if (defaults[i] != "") { # default handling
+            print "#ifdef PNG_" i >out
+         }
+         print def i, "PNG_" i end >out
+         if (defaults[i] != "") {
+            print "#else /*default*/" >out
+            # And add the default definition for the benefit
+            # of later settings an options test:
+            print "# define PNG_" i defaults[i] >out
+            print def i defaults[i] end >out
+         }
+         print "#endif" >out
+         doneset[i] = 1
+         ++movement
+      }
+      if (!finished && !movement) {
+         print "setting: loop or missing setting in 'requires', cannot process:"
+         for (i in setting) if (!doneset[i]) {
+            print "  setting", i, "requires" setting[i]
+         }
+         exit 1
+      }
+   }
+   print comment, "end of settings", cend >out
+   # Now do the options - somewhat more complex.  The dependency
+   # tree is thus:
+   #
+   #   name     >     name
+   #   name requires  name
+   #   name if        name
+   #   name enabledby name
+   #
+   # First build a list 'tree' by option of all the things on which
+   # it depends.
+   print "" >out
+   print "/* OPTIONS */" >out
+   print comment, "options", cend >out
+   for (opt in enabledby) tree[opt] = 1  # may not be explicit options
+   for (opt in option) if (opt != "") {
+      o = option[opt]
+      # option should always be one of the following values
+      if (o != "on" && o != "off" && o != "disabled" && o != "enabled") {
+         print "internal option error (" o ")"
+         exit 1
+      }
+      tree[opt] = ""   # so unlisted options marked
+   }
+   for (opt in tree) if (opt != "") {
+      if (tree[opt] == 1) {
+         tree[opt] = ""
+         if (option[opt] != "") {
+            print "internal error (1)"
+            exit 1
+         }
+         # Macros only listed in 'enables' remain off unless
+         # one of the enabling macros is on.
+         option[opt] = "disabled"
+      }
+      split("", list) # clear 'list'
+      # Now add every requires, iffs or enabledby entry to 'list'
+      # so that we can add a unique list of requirements to tree[i]
+      split(requires[opt] iffs[opt] enabledby[opt], r)
+      for (i in r) list[r[i]] = 1
+      for (i in list) tree[opt] = tree[opt] " " i
+   }
+   # print the tree for extreme debugging
+   if (deb > 2) for (i in tree) if (i != "") print i, "depends-on" tree[i]
+   # Ok, now check all options marked explicitly 'on' or 'off':
+   #
+   # If an option[opt] is 'on' then turn on all requires[opt]
+   # If an option[opt] is 'off' then turn off all enabledby[opt]
+   #
+   # Error out if we have to turn 'on' an 'off' option or vice versa.
+   npending = 0
+   for (opt in option) if (opt != "") {
+      if (option[opt] == "on" || option[opt] == "off") {
+         pending[++npending] = opt
+      }
+   }
+   err = 0 # set on error
+   while (npending > 0) {
+      opt = pending[npending--]
+      if (option[opt] == "on") {
+         nreqs = split(requires[opt], r)
+         for (j=1; j<=nreqs; ++j) {
+            if (option[r[j]] == "off") {
+               print "option", opt, "turned on, but requirement", r[j], "is turned off"
+               err = 1
+            } else if (option[r[j]] != "on") {
+               option[r[j]] = "on"
+               pending[++npending] = r[j]
+            }
+         }
+      } else {
+         if (option[opt] != "off") {
+            print "internal error (2)"
+            exit 1
+         }
+         nreqs = split(enabledby[opt], r)
+         for (j=1; j<=nreqs; ++j) {
+            if (option[r[j]] == "on") {
+               print "option", opt, "turned off, but enabled by", r[j], "which is turned on"
+               err = 1
+            } else if (option[r[j]] != "off") {
+               option[r[j]] = "off"
+               pending[++npending] = r[j]
+            }
+         }
+      }
+   }
+   if (err) exit 1
+   # option[i] is now the complete list of all the tokens we may
+   # need to output, go through it as above, depth first.
+   finished = 0
+   while (!finished) {
+      finished = 1
+      movement = 0 # done nothing
+      for (i in option) if (!done[i]) {
+         nreqs = split(tree[i], r)
+         if (nreqs > 0) {
+            for (j=1; j<=nreqs; ++j) if (!done[r[j]]) {
+               break
+            }
+            if (j<=nreqs) {
+               finished = 0
+               continue  # next option
+            }
+         }
+         # All the requirements have been processed, output
+         # this option.  An option is _SUPPORTED if:
+         #
+         # all 'requires' are _SUPPORTED AND
+         # at least one of the 'if' options are _SUPPORTED AND
+         # EITHER:
+         #   The name is _SUPPORTED (on the command line)
+         # OR:
+         #   an 'enabledby' is _SUPPORTED
+         # OR:
+         #   NO_name is not defined AND
+         #   the option is not disabled; an option is disabled if:
+         #    option == off
+         #    option == disabled && everything != on
+         #    option == "" && everything == off
+         if (deb) print "option", i
+         print "" >out
+         print "/* option:", i, option[i] >out
+         print " *   requires:  " requires[i] >out
+         print " *   if:      " iffs[i] >out
+         print " *   enabled-by:" enabledby[i], "*/" >out
+         print "#undef PNG_on" >out
+         print "#define PNG_on 1" >out
+         # requires
+         nreqs = split(requires[i], r)
+         for (j=1; j<=nreqs; ++j) {
+            print "#ifndef PNG_" r[j] "_SUPPORTED" >out
+            print "#   undef PNG_on /*!" r[j] "*/" >out
+            # this error appears in the final output if something
+            # was switched 'on' but the processing above to force
+            # the requires did not work
+            if (option[i] == "on") {
+               print error, i, "requires", r[j] end >out
+            }
+            print "#endif" >out
+         }
+         # if
+         nreqs = split(iffs[i], r)
+         print "#undef PNG_no_if" >out
+         if (nreqs > 0) {
+            print "/* if" iffs[i], "*/" >out
+            print "#define PNG_no_if 1" >out
+            for (j=1; j<=nreqs; ++j) {
+               print "#ifdef PNG_" r[j] "_SUPPORTED" >out
+               print "#   undef PNG_no_if /*" r[j] "*/" >out
+               print "#endif" >out
+            }
+            print "#ifdef PNG_no_if /*missing if*/" >out
+            print "#   undef PNG_on" >out
+            # There is no checking above for this, because we
+            # don't know which 'if' to choose, so whine about
+            # it here:
+            if (option[i] == "on") {
+               print error, i, "needs one of:", iffs[i] end >out
+            }
+            print "#endif" >out
+         }
+         print "#ifdef PNG_on /*requires, if*/" >out
+         # enables
+         print "#   undef PNG_not_enabled" >out
+         print "#   define PNG_not_enabled 1" >out
+         print "   /* enabled by" enabledby[i], "*/" >out
+         nreqs = split(enabledby[i], r)
+         for (j=1; j<=nreqs; ++j) {
+            print "#ifdef PNG_" r[j] "_SUPPORTED" >out
+            print "#   undef PNG_not_enabled /*" r[j] "*/" >out
+            # Oops, probably not intended (should be factored
+            # out by the checks above).
+            if (option[i] == "off") {
+               print error, i, "enabled by:", r[j] end >out
+            }
+            print "#endif" >out
+         }
+         print "#   ifndef PNG_" i "_SUPPORTED /*!command line*/" >out
+         print "#    ifdef PNG_not_enabled /*!enabled*/" >out
+         if (option[i] == "off" || option[i] == "disabled" && everything != "on" || option[i] == "enabled" && everything == "off") {
+            print "#      undef PNG_on /*default off*/" >out
+         } else {
+            print "#      ifdef PNG_NO_" i >out
+            print "#       undef PNG_on /*turned off*/" >out
+            print "#      endif" >out
+            print "#      ifdef PNG_NO_" i "_SUPPORTED" >out
+            print "#       undef PNG_on /*turned off*/" >out
+            print "#      endif" >out
+         }
+         print "#    endif /*!enabled*/" >out
+         print "#    ifdef PNG_on" >out
+         # The _SUPPORTED macro must be defined so that dependent
+         # options output later work.
+         print "#      define PNG_" i "_SUPPORTED" >out
+         print "#    endif" >out
+         print "#   endif /*!command line*/" >out
+         # If PNG_on is still set the option should be defined in
+         # pnglibconf.h
+         print "#   ifdef PNG_on" >out
+         if (i ~ /^fail_/) {
+            print error, i, "is on: enabled by:" iffs[i] enabledby[i] ", requires" requires[i] end >out
+         } else if (i !~ /^ok_/) {
+            print def i sup >out
+         }
+         print "#   endif /* definition */" >out
+         print "#endif /*requires, if*/" >out
+         if (logunsupported || i ~ /^ok_/) {
+            print "#ifndef  PNG_on" >out
+            if (logunsupported) {
+               print und i une >out
+            }
+            if (i ~ /^ok_/) {
+               print error, i, "not enabled: requires:" requires[i] ", enabled by:" iffs[i] enabledby[i] end >out
+            }
+            print "#endif" >out
+         }
+         done[i] = 1
+         ++movement
+      }
+      if (!finished && !movement) {
+         print "option: loop or missing option in dependency tree, cannot process:"
+         for (i in option) if (!done[i]) {
+            print "  option", i, "depends on" tree[i], "needs:"
+            nreqs = split(tree[i], r)
+            if (nreqs > 0) for (j=1; j<=nreqs; ++j) if (!done[r[j]]) {
+               print "   " r[j]
+            }
+         }
+         exit 1
+      }
+   }
+   print comment, "end of options", cend >out
+   # Regular end - everything looks ok
+   if (protect != "") {
+      print start "#endif", cx, protect, "*/" end >out
+   }
+}
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/pnglibconf.dfa b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/pnglibconf.dfa
new file mode 100644
index 0000000..b0ccd39
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/pnglibconf.dfa
@@ -0,0 +1,578 @@
+# scripts/pnglibconf.dfa - library build configuration control
+#
+@/*- pnglibconf.dfn intermediate file
+@ *  generated from scripts/pnglibconf.dfa
+@ */
+#
+com pnglibconf.h - library build configuration
+com
+version
+com
+com Copyright (c) 1998-2011 Glenn Randers-Pehrson
+com
+com This code is released under the libpng license.
+com For conditions of distribution and use, see the disclaimer
+com and license in png.h
+com
+file pnglibconf.h scripts/pnglibconf.dfa PNGLCONF_H
+# This file is preprocessed by scripts/options.awk and the
+# C compiler to generate 'pnglibconf.h' - a list of all the
+# configuration options.  The file lists the various options
+# that can *only* be specified during the libpng build;
+# pnglibconf.h freezes the definitons selected for the specific
+# build.
+#
+# The syntax is detailed in scripts/options.awk, this is a summary
+# only:
+#
+# setting <name> [requires ...] [default]
+#    #define PNG_<name> <value>  /* value comes from current setting */
+# option <name> [requires ...] [if ...] [enables ...] [disabled]
+#    #define PNG_<name>_SUPPORTED if the requirements are met and
+#    enable the other options listed
+# chunk <name> [requires ...] [disabled]
+#    Enable chunk processing for the given ancillary chunk
+#
+# Note that the 'on' and 'off' keywords, while valid on both option
+# and chunk, should not be used in this file because they force the
+# relevant options on or off.
+#----------------------------------------------------------------------
+# The following setting, option and chunk values can all be changed
+# while building libpng:
+#
+# setting: change 'setting' lines to fine tune library performance,
+#   changes to the settings don't affect the libpng API functionally
+#
+# option: change 'option' lines to remove or add capabilities from
+#   or to the library; options change the library API
+#
+# chunk: change 'chunk' lines to remove capabilities to process
+#   optional ('ancillary') chunks.  This does not prevent PNG
+#   decoding but does change the libpng API because some chunks
+#   will be ignored.
+#
+# There are three ways of disabling features, in no particular order:
+#
+# 1) Create 'pngusr.h', enter the required private build information
+# detailed below and #define PNG_NO_<option> for each option you
+# don't want in that file in that file.  You can also turn on options
+# using PNG_<option>_SUPPORTED.  When you have finished rerun
+# configure and rebuild pnglibconf.h file with -DPNG_USER_CONFIG:
+#
+#  make clean
+#  CPPFLAGS='-DPNG_USER_CONFIG' ./configure
+#  make pnglibconf.h
+#
+# pngusr.h is only used during the creation of pnglibconf.h, but it
+# is safer to ensure that -DPNG_USER_CONFIG is specified throughout
+# the build by changing the CPPFLAGS passed to the initial ./configure
+#
+# 2) Add definitions of the settings you want to change to
+# CPPFLAGS; for example:
+#
+#   -DPNG_DEFAULT_READ_MACROS=0
+#
+# (This would change the default to *not* use read macros.)  Be
+# very careful to change only settings that don't alter the API
+# because this approach bypasses the private build checking.  You
+# can also change settings from pngpriv.h (read pngpriv.h) safely
+# without API changes.  Do that in the same way.
+#
+# 3) Write a new '.dfa' file (say 'pngusr.dfa') and in this file
+# provide override values for setting entries and turn option or
+# chunk values explicitly 'on' or 'off':
+#
+#    setting FOO default VALUE
+#    option BAR [on|off]
+#
+# Then add this file to the options.awk command line (the *first*
+# one) after this file.  The make macro DFA_XTRA is provided to make
+# this easier (set it like CPPFLAGS prior to running ./configure).
+# Look at the builds below contrib/pngminim for some extreme examples
+# of how this can be used.
+#
+# Don't edit this file unless you are contributing a patch to
+# libpng and need new or modified options/settings.
+#----------------------------------------------------------------------
+# The following causes commented out #undef lines to be written to
+# pnglibconf.h; this can be stopped by logunsupported=0 in a later
+# file or on the command line (after pnglibconf.dfa)
+logunsupported = 1
+# PNG_USER_CONFIG has to be defined on the compiler command line
+# to cause pngusr.h to be read while constructing pnglibconf.h
+#
+# If you create a private DLL you need to define the following
+# macros in the file 'pngusr.h' and set -DPNG_USER_CONFIG for
+# compilation (i.e. in CFLAGS.)
+# #define PNG_USER_PRIVATEBUILD \
+#     <Describes by whom and why this version of the DLL was built>
+#  e.g. #define PNG_USER_PRIVATEBUILD "Build by MyCompany for xyz reasons."
+# #define PNG_USER_DLLFNAME_POSTFIX <two-letter postfix that serve to
+#        distinguish your DLL from those of the official release. These
+#        correspond to the trailing letters that come after the version
+#        number and must match your private DLL name>
+#  e.g. // private DLL "libpng13gx.dll"
+#       #define PNG_USER_DLLFNAME_POSTFIX "gx"
+#
+# The following macros are also at your disposal if you want to complete the
+# DLL VERSIONINFO structure.
+# - PNG_USER_VERSIONINFO_COMMENTS
+# - PNG_USER_VERSIONINFO_COMPANYNAME
+# - PNG_USER_VERSIONINFO_LEGALTRADEMARKS
+@#ifdef PNG_USER_CONFIG
+@#  include "pngusr.h"
+@#endif
+# This is a special fixup for the Watcom C compiler on Windows, which has
+# multiple procedure call standards.  Unless PNG_API_RULE is set explicitly
+# (i.e. if it is not defined at this point) it will be forced to '2' here when
+# using Watcom.  This indicates to the other header files that Watcom behaviour
+# is required where appropriate.
+@#ifdef __WATCOMC__
+@#  ifndef PNG_API_RULE
+@#     define PNG_API_RULE 2 /* Use Watcom calling conventions */
+@#  endif
+@#endif
+# Note that PNG_USR_CONFIG only has an effect when building
+# pnglibconf.h
+setting USER_CONFIG
+setting USER_PRIVATEBUILD
+setting USER_DLLFNAME_POSTFIX
+setting USER_VERSIONINFO_COMMENTS
+setting USER_VERSIONINFO_COMPANYNAME
+setting USER_VERSIONINFO_LEGALTRADEMARKS
+# Record the 'API rule' used to select calling conventions on
+# those systems that support such things (see all the comments in
+# pngconf.h)
+# Changing this setting has a fundamental affect on the PNG ABI,
+# do not release shared libraries with this changed.
+setting API_RULE default 0
+# Default to using the read macros
+setting DEFAULT_READ_MACROS default 1
+# The alternative is to call functions to read PNG values, if
+# the functions are turned *off* the read macros must always
+# be enabled, so turning this off will actually force the
+# USE_READ_MACROS option on (see pngconf.h)
+option READ_INT_FUNCTIONS requires READ
+# The same for write, but these can only be switched off if
+# no writing is required at all - hence the use of an 'enables'
+# not a 'requires' below:
+option WRITE_INT_FUNCTIONS disabled
+option WRITE enables WRITE_INT_FUNCTIONS
+# Generic options - affect both read and write.
+option WARNINGS
+option BENIGN_ERRORS
+option MNG_FEATURES
+# Arithmetic options, the first is the big switch that chooses between internal
+# floating and fixed point arithmetic implementations - it does not affect any
+# APIs.  The second two (the _POINT settings) switch off individual APIs.
+option FLOATING_ARITHMETIC
+option FLOATING_POINT enables ok_math
+option FIXED_POINT enables ok_math
+# Added at libpng version 1.4.0
+option ERROR_TEXT
+# The following is always on (defined empty)
+setting CALLOC_SUPPORTED default
+# This protects us against compilers that run on a windowing system
+# and thus don't have or would rather us not use the stdio types:
+# stdin, stdout, and stderr.  The only one currently used is stderr
+# in png_error() and png_warning().  #defining PNG_NO_CONSOLE_IO will
+# prevent these from being compiled and used. #defining PNG_NO_STDIO
+# will also prevent these, plus will prevent the entire set of stdio
+# macros and functions (FILE *, printf, etc.) from being compiled and used,
+# unless (PNG_DEBUG > 0) has been #defined.
+option STDIO
+option CONSOLE_IO requires STDIO
+# Note: prior to 1.5.0 this option could not be disabled if STDIO
+# was enabled.  Prior to 1.5.3 this option required STDIO
+option TIME_RFC1123
+# PNG_SETJMP_NOT_SUPPORTED is an old equivalent for NO_SETJMP
+option SETJMP
+= NO_SETJMP SETJMP_NOT_SUPPORTED
+# For the moment this is disabled (no code support):
+option ERROR_NUMBERS disabled
+# If this is disabled it is not possible for apps to get the
+# values from the 'info' structure, this effectively removes
+# quite a lot of the READ API.
+option EASY_ACCESS
+# Added at libpng-1.2.0
+option USER_MEM
+# Added at libpng-1.4.0
+option IO_STATE
+# This is only for PowerPC big-endian and 680x0 systems
+# some testing, not enabled by default.
+# NO LONGER USED
+#option READ_BIG_ENDIAN disabled
+# Allow users to control limits on what the READ code will
+# read:
+# Added at libpng-1.2.43; adds limit fields to png_struct,
+# allows some usages of these fields
+option USER_LIMITS
+# Added at libpng-1.2.6; adds setting APIs, allows additional
+# usage of this field (UTSL)
+option SET_USER_LIMITS requires USER_LIMITS
+# Feature added at libpng-1.4.0, this flag added at 1.4.1
+option SET_USER_LIMITS enables SET_CHUNK_CACHE_LIMIT
+# Feature added at libpng-1.4.1, this flag added at 1.4.1
+option SET_USER_LIMITS enables SET_CHUNK_MALLOC_LIMIT
+# Added at libpng-1.0.16 and 1.2.6.  To accept all valid PNGs no matter
+# how large, set these two limits to 0x7fffffff
+setting USER_WIDTH_MAX default 1000000
+setting USER_HEIGHT_MAX default 1000000
+# Added at libpng-1.2.43.  To accept all valid PNGs no matter
+# how large, set these two limits to 0.
+setting USER_CHUNK_CACHE_MAX default 0
+# Added at libpng-1.2.43
+setting USER_CHUNK_MALLOC_MAX default 0
+# All of the following options relate to code capabilities for
+# processing image data before creating a PNG or after reading one.
+# You can remove these capabilities safely and still be PNG
+# conformant, however the library that results is still non-standard.
+# See the comments above about how to change options and settings.
+# READ options
+option READ enables READ_INTERLACING
+# Disabling READ_16BIT does not disable reading 16-bit PNG files, but it
+# forces them to be chopped down to 8-bit, and disables any 16-bit
+# processing after that has happened.  You need to be sure to enable
+# READ_SCALE_16_TO_8 or READ_STRIP_16_TO_8 when you disable READ_16BIT for
+# this to work properly.  You should disable the other option if you need to
+# ensure a particular conversion (otherwise the app can chose.)
+option READ_16BIT requires READ enables 16BIT
+option READ_QUANTIZE requires READ
+option READ_TRANSFORMS requires READ
+= NO_READ_TRANSFORMS READ_TRANSFORMS_NOT_SUPPORTED
+option READ_EXPAND requires READ_TRANSFORMS
+option READ_EXPAND_16 requires READ_TRANSFORMS READ_16BIT enables READ_EXPAND
+option READ_SHIFT requires READ_TRANSFORMS
+option READ_PACK requires READ_TRANSFORMS
+option READ_BGR requires READ_TRANSFORMS
+option READ_SWAP requires READ_TRANSFORMS READ_16BIT
+option READ_PACKSWAP requires READ_TRANSFORMS
+option READ_INVERT requires READ_TRANSFORMS
+option READ_BACKGROUND requires READ_TRANSFORMS enables READ_STRIP_ALPHA
+option READ_STRIP_16_TO_8 requires READ_TRANSFORMS
+option READ_SCALE_16_TO_8 requires READ_TRANSFORMS
+option READ_FILLER requires READ_TRANSFORMS
+option READ_GAMMA requires READ_TRANSFORMS enables READ_gAMA
+option READ_GRAY_TO_RGB requires READ_TRANSFORMS
+option READ_ALPHA_MODE requires READ_TRANSFORMS enables READ_GAMMA
+option READ_SWAP_ALPHA requires READ_TRANSFORMS
+option READ_INVERT_ALPHA requires READ_TRANSFORMS
+option READ_STRIP_ALPHA requires READ_TRANSFORMS
+option READ_USER_TRANSFORM requires READ_TRANSFORMS
+option READ_RGB_TO_GRAY requires READ_TRANSFORMS
+option PROGRESSIVE_READ requires READ
+option SEQUENTIAL_READ requires READ
+# You can define PNG_NO_PROGRESSIVE_READ if you don't do progressive reading.
+# This is not talking about interlacing capability!  You'll still have
+# interlacing unless you turn off the following which is required
+# for PNG-compliant decoders.  (In other words, do not do this - in
+# fact it can't be disabled from the command line!)
+#option READ_INTERLACING requires READ
+option READ_COMPOSITE_NODIV requires READ
+= NO_READ_COMPOSITE_NODIV NO_READ_COMPOSITED_NODIV
+# Inch conversions
+option INCH_CONVERSIONS
+= INCH_CONVERSIONS INCH_CONVERSIONS
+# API to build a grayscale palette
+option BUILD_GRAYSCALE_PALETTE
+# IN DEVELOPMENT
+# These are currently experimental features; define them if you want
+# NOTHING HERE
+# WRITE options
+option WRITE
+# Disabling WRITE_16BIT prevents 16-bit PNG files from being
+# generated.
+option WRITE_16BIT requires WRITE enables 16BIT
+option WRITE_TRANSFORMS requires WRITE
+= NO_WRITE_TRANSFORMS WRITE_TRANSFORMS_NOT_SUPPORTED
+option WRITE_SHIFT requires WRITE_TRANSFORMS
+option WRITE_PACK requires WRITE_TRANSFORMS
+option WRITE_BGR requires WRITE_TRANSFORMS
+option WRITE_SWAP requires WRITE_TRANSFORMS WRITE_16BIT
+option WRITE_PACKSWAP requires WRITE_TRANSFORMS
+option WRITE_INVERT requires WRITE_TRANSFORMS
+option WRITE_FILLER requires WRITE_TRANSFORMS
+option WRITE_SWAP_ALPHA requires WRITE_TRANSFORMS
+option WRITE_INVERT_ALPHA requires WRITE_TRANSFORMS
+option WRITE_USER_TRANSFORM requires WRITE_TRANSFORMS
+# This is not required for PNG-compliant encoders, but can cause
+# trouble if left undefined
+option WRITE_INTERLACING requires WRITE
+# The following depends, internally, on WEIGHT_SHIFT and COST_SHIFT
+# where are set below.
+option WRITE_WEIGHTED_FILTER requires WRITE
+option WRITE_FLUSH requires WRITE
+# Note: these can be turned off explicitly if not required by the
+# apps implementing the user transforms
+option USER_TRANSFORM_PTR if READ_USER_TRANSFORM WRITE_USER_TRANSFORM
+option USER_TRANSFORM_INFO if READ_USER_TRANSFORM WRITE_USER_TRANSFORM
+# This enables API to set compression parameters for compressing
+# non-IDAT chunks (zTXt, iTXt, iCCP, and unknown chunks).  This feature
+# was added at libpng-1.5.3.
+option WRITE_CUSTOMIZE_ZTXT_COMPRESSION requires WRITE
+# Any chunks you are not interested in, you can undef here.  The
+# ones that allocate memory may be expecially important (hIST,
+# tEXt, zTXt, tRNS, pCAL).  Others will just save time and make png_info
+# a bit smaller.
+# The size of the png_text structure changed in libpng-1.0.6 when
+# iTXt support was added.  iTXt support was turned off by default through
+# libpng-1.2.x, to support old apps that malloc the png_text structure
+# instead of calling png_set_text() and letting libpng malloc it.  It
+# was turned on by default in libpng-1.4.0.
+option READ_ANCILLARY_CHUNKS requires READ
+# PNG_READ_ANCILLARY_CHUNKS_NOT_SUPPORTED is deprecated.
+= NO_READ_ANCILLARY_CHUNKS READ_ANCILLARY_CHUNKS_NOT_SUPPORTED
+option WRITE_ANCILLARY_CHUNKS requires WRITE
+# PNG_WRITE_ANCILLARY_CHUNKS_NOT_SUPPORTED is deprecated.
+= NO_WRITE_ANCILLARY_CHUNKS WRITE_ANCILLARY_CHUNKS_NOT_SUPPORTED
+# These options disable *all* the text chunks if turned off
+option READ_TEXT requires READ_ANCILLARY_CHUNKS enables TEXT
+option WRITE_TEXT requires WRITE_ANCILLARY_CHUNKS enables TEXT
+# Moved to pnglibconf.h at libpng-1.5.0
+# Feature support: in 1.4 this was in pngconf.h, but the following
+# features have no affect on the libpng API.  Add library
+# only features to the end of this list.  Add features that
+# affect the API above.  (Note: the list of chunks follows
+# the library-only settings.)
+#
+# BUILD TIME ONLY OPTIONS
+#   These options do not affect the API but rather alter how the
+#   API is implemented, they get recorded in pnglibconf.h, but
+#   can't be changed by the application.
+# Check the correctness of cHRM chunks
+option CHECK_cHRM requires cHRM
+#
+# Artificially align memory - the code typically aligns to 8 byte
+# boundaries if this is switched on, it's a small waste of space
+# but can help (in theory) on some architectures.  Only affects
+# internal structures.  Added at libpng 1.4.0
+option ALIGN_MEMORY
+# Buggy compilers (e.g., gcc 2.7.2.2) need PNG_NO_POINTER_INDEXING
+# See png[wr]util.c, normally this should always be *on*
+option POINTER_INDEXING
+# Other defines for things like memory and the like can go here.
+# BUILD TIME SETTINGS
+# Like build time options these do not affect the API, but they
+# may be useful to applications because they record details of
+# how the API will behave particularly with regard to overall
+# accuracy.
+# This controls how fine the quantizing gets.  As this allocates
+# a largish chunk of memory (32K), those who are not as concerned
+# with quantizing quality can decrease some or all of these.
+setting QUANTIZE_RED_BITS default 5
+setting QUANTIZE_GREEN_BITS default 5
+setting QUANTIZE_BLUE_BITS default 5
+# This controls how fine the gamma correction becomes when you
+# are only interested in 8 bits anyway.  Increasing this value
+# results in more memory being used, and more pow() functions
+# being called to fill in the gamma tables.  Don't set this value
+# less then 8, and even that may not work (I haven't tested it).
+setting MAX_GAMMA_8 default 11
+# This controls how much a difference in gamma we can tolerate before
+# we actually start doing gamma conversion, it's a fixed point value,
+# so the default below is 0.05, meaning libpng ignores corrections in
+# the range 0.95 to 1.05
+setting GAMMA_THRESHOLD_FIXED default 5000
+# Scaling factor for filter heuristic weighting calculations
+setting WEIGHT_SHIFT default 8
+setting COST_SHIFT default 3
+# Precision to use when converting a floating point value to a PNG
+# extension format string in an sCAL chunk (only relevant if the
+# floating point API is enabled)
+setting sCAL_PRECISION default 5
+# This is the size of the compression buffer, and thus the size of
+# an IDAT chunk.  Make this whatever size you feel is best for your
+# machine.  One of these will be allocated per png_struct.  When this
+# is full, it writes the data to the disk, and does some other
+# calculations.  Making this an extremely small size may slow
+# the library down, but you may want to experiment to determine
+# where it becomes significant, if you are concerned with memory
+# usage.  Note that zlib allocates at least 32Kb also.  For readers,
+# this describes the size of the buffer available to read the data in.
+# Unless this gets smaller than the size of a row (compressed),
+# it should not make much difference how big this is.
+setting ZBUF_SIZE default 8192
+# Ancillary chunks
+chunk bKGD
+chunk cHRM
+chunk gAMA
+chunk hIST
+chunk iCCP
+chunk iTXt
+chunk oFFs
+chunk pCAL
+chunk sCAL
+chunk pHYs
+chunk sBIT
+chunk sPLT
+chunk sRGB
+chunk tEXt requires TEXT
+chunk tIME
+chunk tRNS
+chunk zTXt
+# This only affects support of the optional PLTE chunk in RGB and RGBA
+# images.  Notice that READ_ANCILLARY_CHUNKS therefore disables part
+# of the regular chunk reading too.
+option READ_OPT_PLTE requires READ_ANCILLARY_CHUNKS
+option READ_UNKNOWN_CHUNKS requires READ
+option READ_UNKNOWN_CHUNKS enables UNKNOWN_CHUNKS READ_USER_CHUNKS
+option READ_USER_CHUNKS requires READ enables USER_CHUNKS
+option CONVERT_tIME requires WRITE_ANCILLARY_CHUNKS
+# The "tm" structure is not supported on WindowsCE
+@#ifdef _WIN32_WCE
+@#   define PNG_NO_CONVERT_tIME
+@#endif
+option WRITE_FILTER requires WRITE
+option WRITE_UNKNOWN_CHUNKS requires WRITE
+option HANDLE_AS_UNKNOWN
+option SAVE_INT_32 requires WRITE
+# png_save_int_32 is required by the ancillary chunks oFFs and pCAL
+# added at libpng-1.5.4
+option WRITE_OPTIMIZE_CMF requires WRITE
+option READ_COMPRESSED_TEXT disabled
+option READ_iCCP enables READ_COMPRESSED_TEXT
+option READ_iTXt enables READ_COMPRESSED_TEXT
+option READ_zTXt enables READ_COMPRESSED_TEXT
+option READ_COMPRESSED_TEXT enables READ_TEXT
+option WRITE_oFFs enables SAVE_INT_32
+option WRITE_pCAL enables SAVE_INT_32
+option WRITE_COMPRESSED_TEXT disabled
+option WRITE_iCCP enables WRITE_COMPRESSED_TEXT
+option WRITE_iTXt enables WRITE_COMPRESSED_TEXT
+option WRITE_zTXt enables WRITE_COMPRESSED_TEXT
+option WRITE_COMPRESSED_TEXT enables WRITE_TEXT
+# Turn this off to disable png_read_png() and png_write_png() and
+# leave the row_pointers member out of the info structure.
+option INFO_IMAGE
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/pnglibconf.h.prebuilt b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/pnglibconf.h.prebuilt
new file mode 100644
index 0000000..36447ce
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/pnglibconf.h.prebuilt
@@ -0,0 +1,187 @@
+/* libpng STANDARD API DEFINITION */
+/* pnglibconf.h - library build configuration */
+/* Libpng 1.5.9 - February 18, 2012 */
+/* Copyright (c) 1998-2011 Glenn Randers-Pehrson */
+/* This code is released under the libpng license. */
+/* For conditions of distribution and use, see the disclaimer */
+/* and license in png.h */
+/* pnglibconf.h */
+/* Derived from: scripts/pnglibconf.dfa */
+/* If you edit this file by hand you must obey the rules expressed in */
+/* pnglibconf.dfa with respect to the dependencies between the following */
+/* symbols.  It is much better to generate a new file using */
+/* scripts/libpngconf.mak */
+#ifndef PNGLCONF_H
+#define PNGLCONF_H
+/* settings */
+#define PNG_API_RULE 0
+#define PNG_CALLOC_SUPPORTED
+#define PNG_COST_SHIFT 3
+#define PNG_DEFAULT_READ_MACROS 1
+#define PNG_GAMMA_THRESHOLD_FIXED 5000
+#define PNG_MAX_GAMMA_8 11
+#define PNG_QUANTIZE_BLUE_BITS 5
+#define PNG_QUANTIZE_GREEN_BITS 5
+#define PNG_QUANTIZE_RED_BITS 5
+#define PNG_sCAL_PRECISION 5
+#define PNG_USER_CHUNK_CACHE_MAX 0
+#define PNG_USER_CHUNK_MALLOC_MAX 0
+#define PNG_USER_HEIGHT_MAX 1000000
+#define PNG_USER_WIDTH_MAX 1000000
+#define PNG_WEIGHT_SHIFT 8
+#define PNG_ZBUF_SIZE 8192
+/* end of settings */
+/* options */
+#define PNG_16BIT_SUPPORTED
+#define PNG_ALIGN_MEMORY_SUPPORTED
+#define PNG_BENIGN_ERRORS_SUPPORTED
+#define PNG_bKGD_SUPPORTED
+#define PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED
+#define PNG_CHECK_cHRM_SUPPORTED
+#define PNG_cHRM_SUPPORTED
+#define PNG_CONSOLE_IO_SUPPORTED
+#define PNG_CONVERT_tIME_SUPPORTED
+#define PNG_EASY_ACCESS_SUPPORTED
+/*#undef PNG_ERROR_NUMBERS_SUPPORTED*/
+#define PNG_ERROR_TEXT_SUPPORTED
+#define PNG_FIXED_POINT_SUPPORTED
+#define PNG_FLOATING_ARITHMETIC_SUPPORTED
+#define PNG_FLOATING_POINT_SUPPORTED
+#define PNG_gAMA_SUPPORTED
+#define PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+#define PNG_hIST_SUPPORTED
+#define PNG_iCCP_SUPPORTED
+#define PNG_INCH_CONVERSIONS_SUPPORTED
+#define PNG_INFO_IMAGE_SUPPORTED
+#define PNG_IO_STATE_SUPPORTED
+#define PNG_iTXt_SUPPORTED
+#define PNG_MNG_FEATURES_SUPPORTED
+#define PNG_oFFs_SUPPORTED
+#define PNG_pCAL_SUPPORTED
+#define PNG_pHYs_SUPPORTED
+#define PNG_POINTER_INDEXING_SUPPORTED
+#define PNG_PROGRESSIVE_READ_SUPPORTED
+#define PNG_READ_16BIT_SUPPORTED
+#define PNG_READ_ALPHA_MODE_SUPPORTED
+#define PNG_READ_ANCILLARY_CHUNKS_SUPPORTED
+#define PNG_READ_BACKGROUND_SUPPORTED
+#define PNG_READ_BGR_SUPPORTED
+#define PNG_READ_bKGD_SUPPORTED
+#define PNG_READ_cHRM_SUPPORTED
+#define PNG_READ_COMPOSITE_NODIV_SUPPORTED
+#define PNG_READ_COMPRESSED_TEXT_SUPPORTED
+#define PNG_READ_EXPAND_16_SUPPORTED
+#define PNG_READ_EXPAND_SUPPORTED
+#define PNG_READ_FILLER_SUPPORTED
+#define PNG_READ_gAMA_SUPPORTED
+#define PNG_READ_GAMMA_SUPPORTED
+#define PNG_READ_GRAY_TO_RGB_SUPPORTED
+#define PNG_READ_hIST_SUPPORTED
+#define PNG_READ_iCCP_SUPPORTED
+#define PNG_READ_INTERLACING_SUPPORTED
+#define PNG_READ_INT_FUNCTIONS_SUPPORTED
+#define PNG_READ_INVERT_ALPHA_SUPPORTED
+#define PNG_READ_INVERT_SUPPORTED
+#define PNG_READ_iTXt_SUPPORTED
+#define PNG_READ_oFFs_SUPPORTED
+#define PNG_READ_OPT_PLTE_SUPPORTED
+#define PNG_READ_PACK_SUPPORTED
+#define PNG_READ_PACKSWAP_SUPPORTED
+#define PNG_READ_pCAL_SUPPORTED
+#define PNG_READ_pHYs_SUPPORTED
+#define PNG_READ_QUANTIZE_SUPPORTED
+#define PNG_READ_RGB_TO_GRAY_SUPPORTED
+#define PNG_READ_sBIT_SUPPORTED
+#define PNG_READ_SCALE_16_TO_8_SUPPORTED
+#define PNG_READ_sCAL_SUPPORTED
+#define PNG_READ_SHIFT_SUPPORTED
+#define PNG_READ_sPLT_SUPPORTED
+#define PNG_READ_sRGB_SUPPORTED
+#define PNG_READ_STRIP_16_TO_8_SUPPORTED
+#define PNG_READ_STRIP_ALPHA_SUPPORTED
+#define PNG_READ_SUPPORTED
+#define PNG_READ_SWAP_ALPHA_SUPPORTED
+#define PNG_READ_SWAP_SUPPORTED
+#define PNG_READ_tEXt_SUPPORTED
+#define PNG_READ_TEXT_SUPPORTED
+#define PNG_READ_tIME_SUPPORTED
+#define PNG_READ_TRANSFORMS_SUPPORTED
+#define PNG_READ_tRNS_SUPPORTED
+#define PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+#define PNG_READ_USER_CHUNKS_SUPPORTED
+#define PNG_READ_USER_TRANSFORM_SUPPORTED
+#define PNG_READ_zTXt_SUPPORTED
+#define PNG_SAVE_INT_32_SUPPORTED
+#define PNG_sBIT_SUPPORTED
+#define PNG_sCAL_SUPPORTED
+#define PNG_SEQUENTIAL_READ_SUPPORTED
+#define PNG_SET_CHUNK_CACHE_LIMIT_SUPPORTED
+#define PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED
+#define PNG_SETJMP_SUPPORTED
+#define PNG_SET_USER_LIMITS_SUPPORTED
+#define PNG_sPLT_SUPPORTED
+#define PNG_sRGB_SUPPORTED
+#define PNG_STDIO_SUPPORTED
+#define PNG_tEXt_SUPPORTED
+#define PNG_TEXT_SUPPORTED
+#define PNG_TIME_RFC1123_SUPPORTED
+#define PNG_tIME_SUPPORTED
+#define PNG_tRNS_SUPPORTED
+#define PNG_UNKNOWN_CHUNKS_SUPPORTED
+#define PNG_USER_CHUNKS_SUPPORTED
+#define PNG_USER_LIMITS_SUPPORTED
+#define PNG_USER_MEM_SUPPORTED
+#define PNG_USER_TRANSFORM_INFO_SUPPORTED
+#define PNG_USER_TRANSFORM_PTR_SUPPORTED
+#define PNG_WARNINGS_SUPPORTED
+#define PNG_WRITE_16BIT_SUPPORTED
+#define PNG_WRITE_ANCILLARY_CHUNKS_SUPPORTED
+#define PNG_WRITE_BGR_SUPPORTED
+#define PNG_WRITE_bKGD_SUPPORTED
+#define PNG_WRITE_cHRM_SUPPORTED
+#define PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
+#define PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
+#define PNG_WRITE_FILLER_SUPPORTED
+#define PNG_WRITE_FILTER_SUPPORTED
+#define PNG_WRITE_FLUSH_SUPPORTED
+#define PNG_WRITE_gAMA_SUPPORTED
+#define PNG_WRITE_hIST_SUPPORTED
+#define PNG_WRITE_iCCP_SUPPORTED
+#define PNG_WRITE_INTERLACING_SUPPORTED
+#define PNG_WRITE_INT_FUNCTIONS_SUPPORTED
+#define PNG_WRITE_INVERT_ALPHA_SUPPORTED
+#define PNG_WRITE_INVERT_SUPPORTED
+#define PNG_WRITE_iTXt_SUPPORTED
+#define PNG_WRITE_oFFs_SUPPORTED
+#define PNG_WRITE_OPTIMIZE_CMF_SUPPORTED
+#define PNG_WRITE_PACK_SUPPORTED
+#define PNG_WRITE_PACKSWAP_SUPPORTED
+#define PNG_WRITE_pCAL_SUPPORTED
+#define PNG_WRITE_pHYs_SUPPORTED
+#define PNG_WRITE_sBIT_SUPPORTED
+#define PNG_WRITE_sCAL_SUPPORTED
+#define PNG_WRITE_SHIFT_SUPPORTED
+#define PNG_WRITE_sPLT_SUPPORTED
+#define PNG_WRITE_sRGB_SUPPORTED
+#define PNG_WRITE_SUPPORTED
+#define PNG_WRITE_SWAP_ALPHA_SUPPORTED
+#define PNG_WRITE_SWAP_SUPPORTED
+#define PNG_WRITE_tEXt_SUPPORTED
+#define PNG_WRITE_TEXT_SUPPORTED
+#define PNG_WRITE_tIME_SUPPORTED
+#define PNG_WRITE_TRANSFORMS_SUPPORTED
+#define PNG_WRITE_tRNS_SUPPORTED
+#define PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+#define PNG_WRITE_USER_TRANSFORM_SUPPORTED
+#define PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+#define PNG_WRITE_zTXt_SUPPORTED
+#define PNG_zTXt_SUPPORTED
+/* end of options */
+#endif /* PNGLCONF_H */
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/pnglibconf.mak b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/pnglibconf.mak
new file mode 100644
index 0000000..1dbb232
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/pnglibconf.mak
@@ -0,0 +1,58 @@
+#!/usr/bin/make -f
+# pnglibconf.mak - standard make lines for pnglibconf.h
+#
+# These lines are copied from Makefile.am, they illustrate
+# how to automate the build of pnglibconf.h from scripts/pnglibconf.dfa
+# given 'awk' and 'sed'
+# Override as appropriate, these definitions can be overridden on
+# the make command line (AWK='nawk' for example).
+AWK = gawk
+AWK = mawk
+AWK = nawk
+AWK = one-true-awk
+AWK = awk  # Crashes on SunOS 5.10 - use 'nawk'
+CPP = $(CC) -E # Does not work on SUN OS 5.10 - use /lib/cpp
+SED = sed
+COPY = cp
+DELETE = rm -f
+ECHO = echo
+DFA_XTRA = # Appended to scripts/options.awk
+# CPPFLAGS should contain the options to control the result,
+# but DEFS and CFLAGS are also supported here, override
+# as appropriate
+DFNFLAGS = $(DEFS) $(CPPFLAGS) $(CFLAGS)
+# srcdir is a defacto standard for the location of the source
+srcdir = .
+# The standard pnglibconf.h exists as scripts/pnglibconf.h.prebuilt,
+# copy this if the following doesn't work.
+pnglibconf.h: pnglibconf.dfn
+        $(DELETE) $@ dfn.c dfn1.out dfn2.out dfn3.out
+        $(ECHO) '#include "pnglibconf.dfn"' >dfn.c
+        $(CPP) $(DFNFLAGS) dfn.c >dfn1.out
+        $(ECHO) "If 'cpp -e' crashes try /lib/cpp (e.g. CPP='/lib/cpp')" >&2
+        $(SED) -n -e 's|^.*PNG_DEFN_MAGIC *-\(.*\)- *PNG_DEFN_END.*$$|\1|p'\
+            dfn1.out >dfn2.out
+        $(SED) -e 's| *PNG_JOIN *||g' -e 's| *$$||' dfn2.out >dfn3.out
+        $(COPY) dfn3.out $@
+        $(DELETE) dfn.c dfn1.out dfn2.out dfn3.out
+pnglibconf.dfn: $(srcdir)/scripts/pnglibconf.dfa $(srcdir)/scripts/options.awk $(srcdir)/pngconf.h
+        $(DELETE) $@ dfn1.out dfn2.out
+        $(ECHO) "Calling $(AWK) from scripts/pnglibconf.mak" >&2
+        $(ECHO) "If 'awk' crashes try a better awk (e.g. AWK='nawk')" >&2
+        $(AWK) -f $(srcdir)/scripts/options.awk out=dfn1.out version=search\
+                $(srcdir)/pngconf.h $(srcdir)/scripts/pnglibconf.dfa\
+                $(DFA_XTRA) 1>&2
+        $(AWK) -f $(srcdir)/scripts/options.awk out=dfn2.out dfn1.out 1>&2
+        $(COPY) dfn2.out $@
+        $(DELETE) dfn1.out dfn2.out
+clean-pnglibconf:
+        $(DELETE) pnglibconf.h pnglibconf.dfn dfn.c dfn1.out dfn2.out dfn3.out
+clean: clean-pnglibconf
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/pngwin.rc b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/pngwin.rc
new file mode 100644
index 0000000..ccca0d3
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/pngwin.rc
@@ -0,0 +1,112 @@
+#define PNG_VERSION_INFO_ONLY
+#include <windows.h>
+#include "../png.h"
+#define _QUOTE(x) # x
+#define QUOTE(x) _QUOTE(x)
+#define PNG_LIBPNG_DLLFNAME "LIBPNG"
+/* Support deprecated PRIVATEBUILD macro */
+#if defined(PRIVATEBUILD) && !defined(PNG_USER_PRIVATEBUILD)
+#  define PNG_USER_PRIVATEBUILD PRIVATEBUILD
+#endif
+#if defined(PNG_USER_DLLFNAME_POSTFIX) && !defined(PNG_USER_PRIVATEBUILD)
+#  error "PNG_USER_PRIVATEBUILD must be defined as a string describing the\
+ custom changes made to the library."
+#endif
+/* Prioritize PNG_USER_x over PNG_LIBPNG_x */
+#ifdef PNG_USER_DLLFNAME_POSTFIX
+#  undef PNG_LIBPNG_DLLFNAME_POSTFIX
+#  define PNG_LIBPNG_DLLFNAME_POSTFIX PNG_USER_DLLFNAME_POSTFIX
+#endif
+#ifdef PNG_USER_VERSIONINFO_COMMENTS
+#  undef PNG_LIBPNG_VERSIONINFO_COMMENTS
+#  define PNG_LIBPNG_VERSIONINFO_COMMENTS PNG_USER_VERSIONINFO_COMMENTS
+#endif
+#if defined(PNG_DEBUG) && (PNG_DEBUG > 0)
+#  define VS_DEBUG VS_FF_DEBUG
+#  ifndef PNG_LIBPNG_DLLFNAME_POSTFIX
+#    define PNG_LIBPNG_DLLFNAME_POSTFIX "D"
+#  endif /* PNG_LIBPNG_DLLFNAME_POSTFIX */
+#  ifndef PNG_LIBPNG_VERSIONINFO_COMMENTS
+#    define PNG_LIBPNG_VERSIONINFO_COMMENTS "PNG_DEBUG=" QUOTE(PNG_DEBUG)
+#  endif /* PNG_LIBPNG_VERSIONINFO_COMMENTS */
+#else
+#  define VS_DEBUG 0
+#  ifndef PNG_LIBPNG_DLLFNAME_POSTFIX
+#     define PNG_LIBPNG_DLLFNAME_POSTFIX
+#  endif /* PNG_LIBPNG_DLLFNAME_POSTFIX */
+#endif /* defined(DEBUG)... */
+#ifdef PNG_USER_PRIVATEBUILD
+#  define VS_PRIVATEBUILD VS_FF_PRIVATEBUILD
+#else
+#  define VS_PRIVATEBUILD 0
+#endif /* PNG_USER_PRIVATEBUILD */
+#ifdef PNG_LIBPNG_SPECIALBUILD
+#  define VS_SPECIALBUILD VS_FF_SPECIALBUILD
+#else
+#  define VS_SPECIALBUILD 0
+#endif /* PNG_LIBPNG_BUILD_SPECIAL */
+#if ((PNG_LIBPNG_BUILD_BASE_TYPE & PNG_LIBPNG_RELEASE_STATUS_MASK) !=\
+      PNG_LIBPNG_BUILD_STABLE)
+#  define VS_PRERELEASE VS_FF_PRERELEASE
+#  define VS_PATCHED 0
+#else
+#  define VS_PRERELEASE 0
+#  if (PNG_LIBPNG_BUILD_BASE_TYPE & PNG_LIBPNG_BUILD_PATCHED)
+#    define VS_PATCHED VS_FF_PATCHED
+#  else
+#    define VS_PATCHED 0
+#  endif
+#endif
+VS_VERSION_INFO VERSIONINFO
+FILEVERSION PNG_LIBPNG_VER_MAJOR, PNG_LIBPNG_VER_MINOR, PNG_LIBPNG_VER_RELEASE, PNG_LIBPNG_VER_BUILD
+PRODUCTVERSION PNG_LIBPNG_VER_MAJOR, PNG_LIBPNG_VER_MINOR, PNG_LIBPNG_VER_RELEASE, PNG_LIBPNG_VER_BUILD
+FILEFLAGSMASK VS_FFI_FILEFLAGSMASK
+FILEFLAGS VS_DEBUG | VS_PRIVATEBUILD | VS_SPECIALBUILD | VS_PRERELEASE | VS_PATCHED
+FILEOS VOS__WINDOWS32
+FILETYPE VFT_DLL
+FILESUBTYPE VFT2_UNKNOWN
+BEGIN
+  BLOCK "StringFileInfo"
+  BEGIN BLOCK "040904E4" /* Language type = U.S English(0x0409) and Character Set = Windows, Multilingual(0x04E4) */
+    BEGIN
+#ifdef PNG_LIBPNG_VERSIONINFO_COMMENTS
+      VALUE "Comments", PNG_LIBPNG_VERSIONINFO_COMMENTS "\000"
+#endif /* PNG_LIBPNG_VERSIONINFO_COMMENTS */
+#ifdef PNG_USER_VERSIONINFO_COMPANYNAME
+      VALUE "CompanyName", PNG_USER_VERSIONINFO_COMPANYNAME "\000"
+#endif /* PNG_USER_VERSIONINFO_COMPANYNAME */
+      VALUE "FileDescription", "PNG image compression library\000"
+      VALUE "FileVersion", PNG_LIBPNG_VER_STRING "\000"
+      VALUE "InternalName", PNG_LIBPNG_DLLFNAME QUOTE(PNG_LIBPNG_VER_DLLNUM) PNG_LIBPNG_DLLFNAME_POSTFIX " (Windows 32 bit)\000"
+      VALUE "LegalCopyright", "\251 1998-2009 Glenn Randers-Pehrson et al.\000"
+#ifdef PNG_USER_VERSIONINFO_LEGALTRADEMARKS
+      VALUE "LegalTrademarks", PNG_USER_VERSIONINFO_LEGALTRADEMARKS "\000"
+#endif /* PNG_USER_VERSIONINFO_LEGALTRADEMARKS */
+      VALUE "OriginalFilename", PNG_LIBPNG_DLLFNAME QUOTE(PNG_LIBPNG_VER_DLLNUM) PNG_LIBPNG_DLLFNAME_POSTFIX ".DLL\000"
+#ifdef PNG_USER_PRIVATEBUILD
+      VALUE "PrivateBuild", PNG_USER_PRIVATEBUILD "\000"
+#endif /* PNG_USER_PRIVATEBUILD */
+      VALUE "ProductName", "LibPNG\000"
+      VALUE "ProductVersion", "1\000"
+#ifdef PNG_LIBPNG_SPECIALBUILD
+      VALUE "SpecialBuild", PNG_LIBPNG_SPECIALBUILD "\000"
+#endif /* PNG_LIBPNG_SPECIALBUILD */
+    END
+  END
+  BLOCK "VarFileInfo"
+  BEGIN
+    VALUE "Translation", 0x0409, 0x04E4
+  END
+END
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/smakefile.ppc b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/smakefile.ppc
new file mode 100644
index 0000000..a85c7cf
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/smakefile.ppc
@@ -0,0 +1,34 @@
+# Amiga powerUP (TM) Makefile
+# makefile for libpng and SAS C V6.58/7.00 PPC compiler
+# Copyright (C) 1998 by Andreas R. Kleinert
+#
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+CC       = scppc
+CFLAGS   = NOSTKCHK NOSINT OPTIMIZE OPTGO OPTPEEP OPTINLOCAL OPTINL IDIR /zlib \
+           OPTLOOP OPTRDEP=8 OPTDEP=8 OPTCOMP=8
+LIBNAME  = libpng.a
+AR       = ppc-amigaos-ar
+AR_FLAGS = cr
+RANLIB   = ppc-amigaos-ranlib
+LDFLAGS  = -r -o
+LDLIBS   =  ../zlib/libzip.a LIB:scppc.a
+LN       = ppc-amigaos-ld
+RM       = delete quiet
+MKDIR    = makedir
+OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o pngread.o \
+       pngerror.o pngpread.o pngwrite.o pngrtran.o pngwtran.o pngrio.o \
+       pngwio.o pngmem.o
+all: $(LIBNAME) pngtest
+$(LIBNAME): $(OBJS)
+            $(AR) $(AR_FLAGS) $@ $(OBJS)
+            $(RANLIB) $@
+pngtest: pngtest.o $(LIBNAME)
+        $(LN) $(LDFLAGS) pngtest LIB:c_ppc.o pngtest.o $(LIBNAME) $(LDLIBS) \
+LIB:end.o
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/sym.dfn b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/sym.dfn
new file mode 100644
index 0000000..83b70d8
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/sym.dfn
@@ -0,0 +1,15 @@
+/* sym.dfn - define format of libpng.sym
+ *
+ * Last changed in libpng version 1.5.0 [January 6, 2011]
+ * Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+#define PNG_EXPORTA(ordinal, type, name, args, attributes)\
+        PNG_DEFN_MAGIC-SYMBOL_PREFIX PNG_JOIN name-PNG_DEFN_END
+#include "../png.h"
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/symbols.def b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/symbols.def
new file mode 100644
index 0000000..c102a3f
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/symbols.def
@@ -0,0 +1,241 @@
+;--------------------------------------------------------------
+; LIBPNG symbol list as a Win32 DEF file
+; Contains all the symbols that can be exported from libpng
+;--------------------------------------------------------------
+LIBRARY
+EXPORTS
+;Version 1.5.9
+ png_access_version_number @1
+ png_set_sig_bytes @2
+ png_sig_cmp @3
+ png_create_read_struct @4
+ png_create_write_struct @5
+ png_get_compression_buffer_size @6
+ png_set_compression_buffer_size @7
+ png_set_longjmp_fn @8
+ png_longjmp @9
+ png_reset_zstream @10
+ png_create_read_struct_2 @11
+ png_create_write_struct_2 @12
+ png_write_sig @13
+ png_write_chunk @14
+ png_write_chunk_start @15
+ png_write_chunk_data @16
+ png_write_chunk_end @17
+ png_create_info_struct @18
+ png_info_init_3 @19
+ png_write_info_before_PLTE @20
+ png_write_info @21
+ png_read_info @22
+ png_convert_to_rfc1123 @23
+ png_convert_from_struct_tm @24
+ png_convert_from_time_t @25
+ png_set_expand @26
+ png_set_expand_gray_1_2_4_to_8 @27
+ png_set_palette_to_rgb @28
+ png_set_tRNS_to_alpha @29
+ png_set_bgr @30
+ png_set_gray_to_rgb @31
+ png_set_rgb_to_gray @32
+ png_set_rgb_to_gray_fixed @33
+ png_get_rgb_to_gray_status @34
+ png_build_grayscale_palette @35
+ png_set_strip_alpha @36
+ png_set_swap_alpha @37
+ png_set_invert_alpha @38
+ png_set_filler @39
+ png_set_add_alpha @40
+ png_set_swap @41
+ png_set_packing @42
+ png_set_packswap @43
+ png_set_shift @44
+ png_set_interlace_handling @45
+ png_set_invert_mono @46
+ png_set_background @47
+ png_set_strip_16 @48
+ png_set_quantize @49
+ png_set_gamma @50
+ png_set_flush @51
+ png_write_flush @52
+ png_start_read_image @53
+ png_read_update_info @54
+ png_read_rows @55
+ png_read_row @56
+ png_read_image @57
+ png_write_row @58
+ png_write_rows @59
+ png_write_image @60
+ png_write_end @61
+ png_read_end @62
+ png_destroy_info_struct @63
+ png_destroy_read_struct @64
+ png_destroy_write_struct @65
+ png_set_crc_action @66
+ png_set_filter @67
+ png_set_filter_heuristics @68
+ png_set_compression_level @69
+ png_set_compression_mem_level @70
+ png_set_compression_strategy @71
+ png_set_compression_window_bits @72
+ png_set_compression_method @73
+ png_init_io @74
+ png_set_error_fn @75
+ png_get_error_ptr @76
+ png_set_write_fn @77
+ png_set_read_fn @78
+ png_get_io_ptr @79
+ png_set_read_status_fn @80
+ png_set_write_status_fn @81
+ png_set_mem_fn @82
+ png_get_mem_ptr @83
+ png_set_read_user_transform_fn @84
+ png_set_write_user_transform_fn @85
+ png_set_user_transform_info @86
+ png_get_user_transform_ptr @87
+ png_set_read_user_chunk_fn @88
+ png_get_user_chunk_ptr @89
+ png_set_progressive_read_fn @90
+ png_get_progressive_ptr @91
+ png_process_data @92
+ png_progressive_combine_row @93
+ png_malloc @94
+ png_calloc @95
+ png_malloc_warn @96
+ png_free @97
+ png_free_data @98
+ png_data_freer @99
+ png_malloc_default @100
+ png_free_default @101
+ png_error @102
+ png_chunk_error @103
+ png_err @104
+ png_warning @105
+ png_chunk_warning @106
+ png_benign_error @107
+ png_chunk_benign_error @108
+ png_set_benign_errors @109
+ png_get_valid @110
+ png_get_rowbytes @111
+ png_get_rows @112
+ png_set_rows @113
+ png_get_channels @114
+ png_get_image_width @115
+ png_get_image_height @116
+ png_get_bit_depth @117
+ png_get_color_type @118
+ png_get_filter_type @119
+ png_get_interlace_type @120
+ png_get_compression_type @121
+ png_get_pixels_per_meter @122
+ png_get_x_pixels_per_meter @123
+ png_get_y_pixels_per_meter @124
+ png_get_pixel_aspect_ratio @125
+ png_get_x_offset_pixels @126
+ png_get_y_offset_pixels @127
+ png_get_x_offset_microns @128
+ png_get_y_offset_microns @129
+ png_get_signature @130
+ png_get_bKGD @131
+ png_set_bKGD @132
+ png_get_cHRM @133
+ png_get_cHRM_fixed @134
+ png_set_cHRM @135
+ png_set_cHRM_fixed @136
+ png_get_gAMA @137
+ png_get_gAMA_fixed @138
+ png_set_gAMA @139
+ png_set_gAMA_fixed @140
+ png_get_hIST @141
+ png_set_hIST @142
+ png_get_IHDR @143
+ png_set_IHDR @144
+ png_get_oFFs @145
+ png_set_oFFs @146
+ png_get_pCAL @147
+ png_set_pCAL @148
+ png_get_pHYs @149
+ png_set_pHYs @150
+ png_get_PLTE @151
+ png_set_PLTE @152
+ png_get_sBIT @153
+ png_set_sBIT @154
+ png_get_sRGB @155
+ png_set_sRGB @156
+ png_set_sRGB_gAMA_and_cHRM @157
+ png_get_iCCP @158
+ png_set_iCCP @159
+ png_get_sPLT @160
+ png_set_sPLT @161
+ png_get_text @162
+ png_set_text @163
+ png_get_tIME @164
+ png_set_tIME @165
+ png_get_tRNS @166
+ png_set_tRNS @167
+ png_get_sCAL @168
+ png_get_sCAL_s @169
+ png_set_sCAL @170
+ png_set_sCAL_s @171
+ png_set_keep_unknown_chunks @172
+ png_handle_as_unknown @173
+ png_set_unknown_chunks @174
+ png_set_unknown_chunk_location @175
+ png_get_unknown_chunks @176
+ png_set_invalid @177
+ png_read_png @178
+ png_write_png @179
+ png_get_copyright @180
+ png_get_header_ver @181
+ png_get_header_version @182
+ png_get_libpng_ver @183
+ png_permit_mng_features @184
+ png_set_strip_error_numbers @185
+ png_set_user_limits @186
+ png_get_user_width_max @187
+ png_get_user_height_max @188
+ png_set_chunk_cache_max @189
+ png_get_chunk_cache_max @190
+ png_set_chunk_malloc_max @191
+ png_get_chunk_malloc_max @192
+ png_get_pixels_per_inch @193
+ png_get_x_pixels_per_inch @194
+ png_get_y_pixels_per_inch @195
+ png_get_x_offset_inches @196
+ png_get_y_offset_inches @197
+ png_get_pHYs_dpi @198
+ png_get_io_state @199
+ png_get_io_chunk_name @200
+ png_get_uint_32 @201
+ png_get_uint_16 @202
+ png_get_int_32 @203
+ png_get_uint_31 @204
+ png_save_uint_32 @205
+ png_save_int_32 @206
+ png_save_uint_16 @207
+ png_set_gamma_fixed @208
+ png_set_filter_heuristics_fixed @209
+ png_get_pixel_aspect_ratio_fixed @210
+ png_get_x_offset_inches_fixed @211
+ png_get_y_offset_inches_fixed @212
+ png_set_sCAL_fixed @213
+ png_get_sCAL_fixed @214
+ png_set_background_fixed @215
+ png_get_io_chunk_type @216
+ png_get_current_row_number @217
+ png_get_current_pass_number @218
+ png_process_data_pause @219
+ png_process_data_skip @220
+ png_set_expand_16 @221
+ png_set_text_compression_level @222
+ png_set_text_compression_mem_level @223
+ png_set_text_compression_strategy @224
+ png_set_text_compression_window_bits @225
+ png_set_text_compression_method @226
+ png_set_alpha_mode @227
+ png_set_alpha_mode_fixed @228
+ png_set_scale_16 @229
+ png_get_cHRM_XYZ @230
+ png_get_cHRM_XYZ_fixed @231
+ png_set_cHRM_XYZ @232
+ png_set_cHRM_XYZ_fixed @233
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/symbols.dfn b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/symbols.dfn
new file mode 100644
index 0000000..1596dde
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/symbols.dfn
@@ -0,0 +1,57 @@
+/* symbols.dfn - find all exported symbols
+ *
+ * Last changed in libpng version 1.5.0 [January 6, 2011]
+ * Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+/* NOTE: making 'symbols.chk' checks both that the exported
+ * symbols in the library don't change and (implicitly) that
+ * scripts/pnglibconf.h.prebuilt is as expected.  If scripts/pnglibconf.h.prebuilt
+ * is remade using scripts/pnglibconf.dfa then this checks the
+ * .dfa file too.
+ */
+#define PNG_EXPORTA(ordinal, type, name, args, attributes)\
+        PNG_DEFN_MAGIC-name @ordinal-PNG_DEFN_END
+#define PNG_REMOVED(ordinal, type, name, args, attributes)\
+        PNG_DEFN_MAGIC-; name @ordinal-PNG_DEFN_END
+#define PNG_EXPORT_LAST_ORDINAL(ordinal)\
+        PNG_DEFN_MAGIC-; @ordinal-PNG_DEFN_END
+/* Read the defaults, but use scripts/pnglibconf.h.prebuilt; the 'standard'
+ * header file.
+ */
+#include "pnglibconf.h.prebuilt"
+#include "../png.h"
+/* Some things are turned off by default.  Turn these things
+ * on here (by hand) to get the APIs they expose and validate
+ * that no harm is done.  This list is the set of options
+ * defaulted to 'off' in scripts/pnglibconf.dfa
+ *
+ * Maintenance: if scripts/pnglibconf.dfa options are changed
+ * from, or to, 'off' this needs updating!
+ */
+#define PNG_BENIGN_ERRORS_SUPPORTED
+#define PNG_ERROR_NUMBERS_SUPPORTED
+#define PNG_READ_BIG_ENDIAN_SUPPORTED  /* should do nothing! */
+#define PNG_INCH_CONVERSIONS_SUPPORTED
+#define PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED
+#undef PNG_H
+#include "../png.h"
+/* Finally there are a couple of places where option support
+ * actually changes the APIs revealed using a #if/#else/#endif
+ * test in png.h, test these here.
+ */
+#undef  PNG_FLOATING_POINT_SUPPORTED /* Exposes 'fixed' APIs */
+#undef  PNG_ERROR_TEXT_SUPPORTED     /* Exposes unsupported APIs */
+#undef PNG_H
+#include "../png.h"
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/vers.dfn b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/vers.dfn
new file mode 100644
index 0000000..548cfb4
--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/scripts/vers.dfn
@@ -0,0 +1,26 @@
+/* vers.dfn - define format of libpng.vers
+ *
+ * Last changed in libpng version 1.5.0 [January 6, 2011]
+ * Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+#define HEADER PNG_DEFN_MAGIC-PNGLIB_LIBNAME {global:-PNG_DEFN_END
+/* NOTE: PNG_JOIN is interpreted by the calling script as a signal to
+ * join the two things on either side, so we can do symbol
+ * substitution within the name, regular C ## joins the pp-tokens,
+ * not their final values.
+ */
+#define PNG_EXPORTA(ordinal, type, name, args, attributes)\
+        PNG_DEFN_MAGIC- SYMBOL_PREFIX PNG_JOIN name;-PNG_DEFN_END
+#define TRAILER PNG_DEFN_MAGIC-local: *; };-PNG_DEFN_END
+HEADER
+#include "../png.h"
+TRAILER