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authorDavid Walter Seikel2013-01-13 17:24:39 +1000
committerDavid Walter Seikel2013-01-13 17:24:39 +1000
commit393b5cd1dc438872af89d334ef6e5fcc59f27d47 (patch)
tree6a14521219942a08a1b95cb2f5a923a9edd60f63 /libraries/irrlicht-1.8/source/Irrlicht/libpng/pngwutil.c
parentAdd a note about rasters suggested start up code. (diff)
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Added Irrlicht 1.8, but without all the Windows binaries.
Diffstat (limited to 'libraries/irrlicht-1.8/source/Irrlicht/libpng/pngwutil.c')
-rw-r--r--libraries/irrlicht-1.8/source/Irrlicht/libpng/pngwutil.c3180
1 files changed, 3180 insertions, 0 deletions
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
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--- /dev/null
+++ b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngwutil.c
@@ -0,0 +1,3180 @@
1
2/* pngwutil.c - utilities to write a PNG file
3 *
4 * Last changed in libpng 1.5.6 [November 3, 2011]
5 * Copyright (c) 1998-2011 Glenn Randers-Pehrson
6 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
7 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
8 *
9 * This code is released under the libpng license.
10 * For conditions of distribution and use, see the disclaimer
11 * and license in png.h
12 */
13
14#include "pngpriv.h"
15
16#ifdef PNG_WRITE_SUPPORTED
17
18#ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
19/* Place a 32-bit number into a buffer in PNG byte order. We work
20 * with unsigned numbers for convenience, although one supported
21 * ancillary chunk uses signed (two's complement) numbers.
22 */
23void PNGAPI
24png_save_uint_32(png_bytep buf, png_uint_32 i)
25{
26 buf[0] = (png_byte)((i >> 24) & 0xff);
27 buf[1] = (png_byte)((i >> 16) & 0xff);
28 buf[2] = (png_byte)((i >> 8) & 0xff);
29 buf[3] = (png_byte)(i & 0xff);
30}
31
32#ifdef PNG_SAVE_INT_32_SUPPORTED
33/* The png_save_int_32 function assumes integers are stored in two's
34 * complement format. If this isn't the case, then this routine needs to
35 * be modified to write data in two's complement format. Note that,
36 * the following works correctly even if png_int_32 has more than 32 bits
37 * (compare the more complex code required on read for sign extention.)
38 */
39void PNGAPI
40png_save_int_32(png_bytep buf, png_int_32 i)
41{
42 buf[0] = (png_byte)((i >> 24) & 0xff);
43 buf[1] = (png_byte)((i >> 16) & 0xff);
44 buf[2] = (png_byte)((i >> 8) & 0xff);
45 buf[3] = (png_byte)(i & 0xff);
46}
47#endif
48
49/* Place a 16-bit number into a buffer in PNG byte order.
50 * The parameter is declared unsigned int, not png_uint_16,
51 * just to avoid potential problems on pre-ANSI C compilers.
52 */
53void PNGAPI
54png_save_uint_16(png_bytep buf, unsigned int i)
55{
56 buf[0] = (png_byte)((i >> 8) & 0xff);
57 buf[1] = (png_byte)(i & 0xff);
58}
59#endif
60
61/* Simple function to write the signature. If we have already written
62 * the magic bytes of the signature, or more likely, the PNG stream is
63 * being embedded into another stream and doesn't need its own signature,
64 * we should call png_set_sig_bytes() to tell libpng how many of the
65 * bytes have already been written.
66 */
67void PNGAPI
68png_write_sig(png_structp png_ptr)
69{
70 png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};
71
72#ifdef PNG_IO_STATE_SUPPORTED
73 /* Inform the I/O callback that the signature is being written */
74 png_ptr->io_state = PNG_IO_WRITING | PNG_IO_SIGNATURE;
75#endif
76
77 /* Write the rest of the 8 byte signature */
78 png_write_data(png_ptr, &png_signature[png_ptr->sig_bytes],
79 (png_size_t)(8 - png_ptr->sig_bytes));
80
81 if (png_ptr->sig_bytes < 3)
82 png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
83}
84
85/* Write the start of a PNG chunk. The type is the chunk type.
86 * The total_length is the sum of the lengths of all the data you will be
87 * passing in png_write_chunk_data().
88 */
89static void
90png_write_chunk_header(png_structp png_ptr, png_uint_32 chunk_name,
91 png_uint_32 length)
92{
93 png_byte buf[8];
94
95#if defined(PNG_DEBUG) && (PNG_DEBUG > 0)
96 PNG_CSTRING_FROM_CHUNK(buf, chunk_name);
97 png_debug2(0, "Writing %s chunk, length = %lu", buf, (unsigned long)length);
98#endif
99
100 if (png_ptr == NULL)
101 return;
102
103#ifdef PNG_IO_STATE_SUPPORTED
104 /* Inform the I/O callback that the chunk header is being written.
105 * PNG_IO_CHUNK_HDR requires a single I/O call.
106 */
107 png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_HDR;
108#endif
109
110 /* Write the length and the chunk name */
111 png_save_uint_32(buf, length);
112 png_save_uint_32(buf + 4, chunk_name);
113 png_write_data(png_ptr, buf, 8);
114
115 /* Put the chunk name into png_ptr->chunk_name */
116 png_ptr->chunk_name = chunk_name;
117
118 /* Reset the crc and run it over the chunk name */
119 png_reset_crc(png_ptr);
120
121 png_calculate_crc(png_ptr, buf + 4, 4);
122
123#ifdef PNG_IO_STATE_SUPPORTED
124 /* Inform the I/O callback that chunk data will (possibly) be written.
125 * PNG_IO_CHUNK_DATA does NOT require a specific number of I/O calls.
126 */
127 png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_DATA;
128#endif
129}
130
131void PNGAPI
132png_write_chunk_start(png_structp png_ptr, png_const_bytep chunk_string,
133 png_uint_32 length)
134{
135 png_write_chunk_header(png_ptr, PNG_CHUNK_FROM_STRING(chunk_string), length);
136}
137
138/* Write the data of a PNG chunk started with png_write_chunk_header().
139 * Note that multiple calls to this function are allowed, and that the
140 * sum of the lengths from these calls *must* add up to the total_length
141 * given to png_write_chunk_header().
142 */
143void PNGAPI
144png_write_chunk_data(png_structp png_ptr, png_const_bytep data,
145 png_size_t length)
146{
147 /* Write the data, and run the CRC over it */
148 if (png_ptr == NULL)
149 return;
150
151 if (data != NULL && length > 0)
152 {
153 png_write_data(png_ptr, data, length);
154
155 /* Update the CRC after writing the data,
156 * in case that the user I/O routine alters it.
157 */
158 png_calculate_crc(png_ptr, data, length);
159 }
160}
161
162/* Finish a chunk started with png_write_chunk_header(). */
163void PNGAPI
164png_write_chunk_end(png_structp png_ptr)
165{
166 png_byte buf[4];
167
168 if (png_ptr == NULL) return;
169
170#ifdef PNG_IO_STATE_SUPPORTED
171 /* Inform the I/O callback that the chunk CRC is being written.
172 * PNG_IO_CHUNK_CRC requires a single I/O function call.
173 */
174 png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_CRC;
175#endif
176
177 /* Write the crc in a single operation */
178 png_save_uint_32(buf, png_ptr->crc);
179
180 png_write_data(png_ptr, buf, (png_size_t)4);
181}
182
183/* Write a PNG chunk all at once. The type is an array of ASCII characters
184 * representing the chunk name. The array must be at least 4 bytes in
185 * length, and does not need to be null terminated. To be safe, pass the
186 * pre-defined chunk names here, and if you need a new one, define it
187 * where the others are defined. The length is the length of the data.
188 * All the data must be present. If that is not possible, use the
189 * png_write_chunk_start(), png_write_chunk_data(), and png_write_chunk_end()
190 * functions instead.
191 */
192static void
193png_write_complete_chunk(png_structp png_ptr, png_uint_32 chunk_name,
194 png_const_bytep data, png_size_t length)
195{
196 if (png_ptr == NULL)
197 return;
198
199 /* On 64 bit architectures 'length' may not fit in a png_uint_32. */
200 if (length > PNG_UINT_32_MAX)
201 png_error(png_ptr, "length exceeds PNG maxima");
202
203 png_write_chunk_header(png_ptr, chunk_name, (png_uint_32)length);
204 png_write_chunk_data(png_ptr, data, length);
205 png_write_chunk_end(png_ptr);
206}
207
208/* This is the API that calls the internal function above. */
209void PNGAPI
210png_write_chunk(png_structp png_ptr, png_const_bytep chunk_string,
211 png_const_bytep data, png_size_t length)
212{
213 png_write_complete_chunk(png_ptr, PNG_CHUNK_FROM_STRING(chunk_string), data,
214 length);
215}
216
217/* Initialize the compressor for the appropriate type of compression. */
218static void
219png_zlib_claim(png_structp png_ptr, png_uint_32 state)
220{
221 if (!(png_ptr->zlib_state & PNG_ZLIB_IN_USE))
222 {
223 /* If already initialized for 'state' do not re-init. */
224 if (png_ptr->zlib_state != state)
225 {
226 int ret = Z_OK;
227 png_const_charp who = "-";
228
229 /* If actually initialized for another state do a deflateEnd. */
230 if (png_ptr->zlib_state != PNG_ZLIB_UNINITIALIZED)
231 {
232 ret = deflateEnd(&png_ptr->zstream);
233 who = "end";
234 png_ptr->zlib_state = PNG_ZLIB_UNINITIALIZED;
235 }
236
237 /* zlib itself detects an incomplete state on deflateEnd */
238 if (ret == Z_OK) switch (state)
239 {
240# ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
241 case PNG_ZLIB_FOR_TEXT:
242 ret = deflateInit2(&png_ptr->zstream,
243 png_ptr->zlib_text_level, png_ptr->zlib_text_method,
244 png_ptr->zlib_text_window_bits,
245 png_ptr->zlib_text_mem_level, png_ptr->zlib_text_strategy);
246 who = "text";
247 break;
248# endif
249
250 case PNG_ZLIB_FOR_IDAT:
251 ret = deflateInit2(&png_ptr->zstream, png_ptr->zlib_level,
252 png_ptr->zlib_method, png_ptr->zlib_window_bits,
253 png_ptr->zlib_mem_level, png_ptr->zlib_strategy);
254 who = "IDAT";
255 break;
256
257 default:
258 png_error(png_ptr, "invalid zlib state");
259 }
260
261 if (ret == Z_OK)
262 png_ptr->zlib_state = state;
263
264 else /* an error in deflateEnd or deflateInit2 */
265 {
266 size_t pos = 0;
267 char msg[64];
268
269 pos = png_safecat(msg, sizeof msg, pos,
270 "zlib failed to initialize compressor (");
271 pos = png_safecat(msg, sizeof msg, pos, who);
272
273 switch (ret)
274 {
275 case Z_VERSION_ERROR:
276 pos = png_safecat(msg, sizeof msg, pos, ") version error");
277 break;
278
279 case Z_STREAM_ERROR:
280 pos = png_safecat(msg, sizeof msg, pos, ") stream error");
281 break;
282
283 case Z_MEM_ERROR:
284 pos = png_safecat(msg, sizeof msg, pos, ") memory error");
285 break;
286
287 default:
288 pos = png_safecat(msg, sizeof msg, pos, ") unknown error");
289 break;
290 }
291
292 png_error(png_ptr, msg);
293 }
294 }
295
296 /* Here on success, claim the zstream: */
297 png_ptr->zlib_state |= PNG_ZLIB_IN_USE;
298 }
299
300 else
301 png_error(png_ptr, "zstream already in use (internal error)");
302}
303
304/* The opposite: release the stream. It is also reset, this API will warn on
305 * error but will not fail.
306 */
307static void
308png_zlib_release(png_structp png_ptr)
309{
310 if (png_ptr->zlib_state & PNG_ZLIB_IN_USE)
311 {
312 int ret = deflateReset(&png_ptr->zstream);
313
314 png_ptr->zlib_state &= ~PNG_ZLIB_IN_USE;
315
316 if (ret != Z_OK)
317 {
318 png_const_charp err;
319 PNG_WARNING_PARAMETERS(p)
320
321 switch (ret)
322 {
323 case Z_VERSION_ERROR:
324 err = "version";
325 break;
326
327 case Z_STREAM_ERROR:
328 err = "stream";
329 break;
330
331 case Z_MEM_ERROR:
332 err = "memory";
333 break;
334
335 default:
336 err = "unknown";
337 break;
338 }
339
340 png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_d, ret);
341 png_warning_parameter(p, 2, err);
342
343 if (png_ptr->zstream.msg)
344 err = png_ptr->zstream.msg;
345 else
346 err = "[no zlib message]";
347
348 png_warning_parameter(p, 3, err);
349
350 png_formatted_warning(png_ptr, p,
351 "zlib failed to reset compressor: @1(@2): @3");
352 }
353 }
354
355 else
356 png_warning(png_ptr, "zstream not in use (internal error)");
357}
358
359#ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
360/* This pair of functions encapsulates the operation of (a) compressing a
361 * text string, and (b) issuing it later as a series of chunk data writes.
362 * The compression_state structure is shared context for these functions
363 * set up by the caller in order to make the whole mess thread-safe.
364 */
365
366typedef struct
367{
368 png_const_bytep input; /* The uncompressed input data */
369 png_size_t input_len; /* Its length */
370 int num_output_ptr; /* Number of output pointers used */
371 int max_output_ptr; /* Size of output_ptr */
372 png_bytep *output_ptr; /* Array of pointers to output */
373} compression_state;
374
375/* Compress given text into storage in the png_ptr structure */
376static int /* PRIVATE */
377png_text_compress(png_structp png_ptr,
378 png_const_charp text, png_size_t text_len, int compression,
379 compression_state *comp)
380{
381 int ret;
382
383 comp->num_output_ptr = 0;
384 comp->max_output_ptr = 0;
385 comp->output_ptr = NULL;
386 comp->input = NULL;
387 comp->input_len = text_len;
388
389 /* We may just want to pass the text right through */
390 if (compression == PNG_TEXT_COMPRESSION_NONE)
391 {
392 comp->input = (png_const_bytep)text;
393 return((int)text_len);
394 }
395
396 if (compression >= PNG_TEXT_COMPRESSION_LAST)
397 {
398 PNG_WARNING_PARAMETERS(p)
399
400 png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_d,
401 compression);
402 png_formatted_warning(png_ptr, p, "Unknown compression type @1");
403 }
404
405 /* We can't write the chunk until we find out how much data we have,
406 * which means we need to run the compressor first and save the
407 * output. This shouldn't be a problem, as the vast majority of
408 * comments should be reasonable, but we will set up an array of
409 * malloc'd pointers to be sure.
410 *
411 * If we knew the application was well behaved, we could simplify this
412 * greatly by assuming we can always malloc an output buffer large
413 * enough to hold the compressed text ((1001 * text_len / 1000) + 12)
414 * and malloc this directly. The only time this would be a bad idea is
415 * if we can't malloc more than 64K and we have 64K of random input
416 * data, or if the input string is incredibly large (although this
417 * wouldn't cause a failure, just a slowdown due to swapping).
418 */
419 png_zlib_claim(png_ptr, PNG_ZLIB_FOR_TEXT);
420
421 /* Set up the compression buffers */
422 /* TODO: the following cast hides a potential overflow problem. */
423 png_ptr->zstream.avail_in = (uInt)text_len;
424
425 /* NOTE: assume zlib doesn't overwrite the input */
426 png_ptr->zstream.next_in = (Bytef *)text;
427 png_ptr->zstream.avail_out = png_ptr->zbuf_size;
428 png_ptr->zstream.next_out = png_ptr->zbuf;
429
430 /* This is the same compression loop as in png_write_row() */
431 do
432 {
433 /* Compress the data */
434 ret = deflate(&png_ptr->zstream, Z_NO_FLUSH);
435
436 if (ret != Z_OK)
437 {
438 /* Error */
439 if (png_ptr->zstream.msg != NULL)
440 png_error(png_ptr, png_ptr->zstream.msg);
441
442 else
443 png_error(png_ptr, "zlib error");
444 }
445
446 /* Check to see if we need more room */
447 if (!(png_ptr->zstream.avail_out))
448 {
449 /* Make sure the output array has room */
450 if (comp->num_output_ptr >= comp->max_output_ptr)
451 {
452 int old_max;
453
454 old_max = comp->max_output_ptr;
455 comp->max_output_ptr = comp->num_output_ptr + 4;
456 if (comp->output_ptr != NULL)
457 {
458 png_bytepp old_ptr;
459
460 old_ptr = comp->output_ptr;
461
462 comp->output_ptr = (png_bytepp)png_malloc(png_ptr,
463 (png_alloc_size_t)
464 (comp->max_output_ptr * png_sizeof(png_charpp)));
465
466 png_memcpy(comp->output_ptr, old_ptr, old_max
467 * png_sizeof(png_charp));
468
469 png_free(png_ptr, old_ptr);
470 }
471 else
472 comp->output_ptr = (png_bytepp)png_malloc(png_ptr,
473 (png_alloc_size_t)
474 (comp->max_output_ptr * png_sizeof(png_charp)));
475 }
476
477 /* Save the data */
478 comp->output_ptr[comp->num_output_ptr] =
479 (png_bytep)png_malloc(png_ptr,
480 (png_alloc_size_t)png_ptr->zbuf_size);
481
482 png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf,
483 png_ptr->zbuf_size);
484
485 comp->num_output_ptr++;
486
487 /* and reset the buffer */
488 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
489 png_ptr->zstream.next_out = png_ptr->zbuf;
490 }
491 /* Continue until we don't have any more to compress */
492 } while (png_ptr->zstream.avail_in);
493
494 /* Finish the compression */
495 do
496 {
497 /* Tell zlib we are finished */
498 ret = deflate(&png_ptr->zstream, Z_FINISH);
499
500 if (ret == Z_OK)
501 {
502 /* Check to see if we need more room */
503 if (!(png_ptr->zstream.avail_out))
504 {
505 /* Check to make sure our output array has room */
506 if (comp->num_output_ptr >= comp->max_output_ptr)
507 {
508 int old_max;
509
510 old_max = comp->max_output_ptr;
511 comp->max_output_ptr = comp->num_output_ptr + 4;
512 if (comp->output_ptr != NULL)
513 {
514 png_bytepp old_ptr;
515
516 old_ptr = comp->output_ptr;
517
518 /* This could be optimized to realloc() */
519 comp->output_ptr = (png_bytepp)png_malloc(png_ptr,
520 (png_alloc_size_t)(comp->max_output_ptr *
521 png_sizeof(png_charp)));
522
523 png_memcpy(comp->output_ptr, old_ptr,
524 old_max * png_sizeof(png_charp));
525
526 png_free(png_ptr, old_ptr);
527 }
528
529 else
530 comp->output_ptr = (png_bytepp)png_malloc(png_ptr,
531 (png_alloc_size_t)(comp->max_output_ptr *
532 png_sizeof(png_charp)));
533 }
534
535 /* Save the data */
536 comp->output_ptr[comp->num_output_ptr] =
537 (png_bytep)png_malloc(png_ptr,
538 (png_alloc_size_t)png_ptr->zbuf_size);
539
540 png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf,
541 png_ptr->zbuf_size);
542
543 comp->num_output_ptr++;
544
545 /* and reset the buffer pointers */
546 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
547 png_ptr->zstream.next_out = png_ptr->zbuf;
548 }
549 }
550 else if (ret != Z_STREAM_END)
551 {
552 /* We got an error */
553 if (png_ptr->zstream.msg != NULL)
554 png_error(png_ptr, png_ptr->zstream.msg);
555
556 else
557 png_error(png_ptr, "zlib error");
558 }
559 } while (ret != Z_STREAM_END);
560
561 /* Text length is number of buffers plus last buffer */
562 text_len = png_ptr->zbuf_size * comp->num_output_ptr;
563
564 if (png_ptr->zstream.avail_out < png_ptr->zbuf_size)
565 text_len += png_ptr->zbuf_size - (png_size_t)png_ptr->zstream.avail_out;
566
567 return((int)text_len);
568}
569
570/* Ship the compressed text out via chunk writes */
571static void /* PRIVATE */
572png_write_compressed_data_out(png_structp png_ptr, compression_state *comp)
573{
574 int i;
575
576 /* Handle the no-compression case */
577 if (comp->input)
578 {
579 png_write_chunk_data(png_ptr, comp->input, comp->input_len);
580
581 return;
582 }
583
584#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED
585 /* The zbuf_size test is because the code below doesn't work if zbuf_size is
586 * '1'; simply skip it to avoid memory overwrite.
587 */
588 if (comp->input_len >= 2 && comp->input_len < 16384 && png_ptr->zbuf_size > 1)
589 {
590 unsigned int z_cmf; /* zlib compression method and flags */
591
592 /* Optimize the CMF field in the zlib stream. This hack of the zlib
593 * stream is compliant to the stream specification.
594 */
595
596 if (comp->num_output_ptr)
597 z_cmf = comp->output_ptr[0][0];
598 else
599 z_cmf = png_ptr->zbuf[0];
600
601 if ((z_cmf & 0x0f) == 8 && (z_cmf & 0xf0) <= 0x70)
602 {
603 unsigned int z_cinfo;
604 unsigned int half_z_window_size;
605 png_size_t uncompressed_text_size = comp->input_len;
606
607 z_cinfo = z_cmf >> 4;
608 half_z_window_size = 1 << (z_cinfo + 7);
609
610 while (uncompressed_text_size <= half_z_window_size &&
611 half_z_window_size >= 256)
612 {
613 z_cinfo--;
614 half_z_window_size >>= 1;
615 }
616
617 z_cmf = (z_cmf & 0x0f) | (z_cinfo << 4);
618
619 if (comp->num_output_ptr)
620 {
621
622 if (comp->output_ptr[0][0] != z_cmf)
623 {
624 int tmp;
625
626 comp->output_ptr[0][0] = (png_byte)z_cmf;
627 tmp = comp->output_ptr[0][1] & 0xe0;
628 tmp += 0x1f - ((z_cmf << 8) + tmp) % 0x1f;
629 comp->output_ptr[0][1] = (png_byte)tmp;
630 }
631 }
632 else
633 {
634 int tmp;
635
636 png_ptr->zbuf[0] = (png_byte)z_cmf;
637 tmp = png_ptr->zbuf[1] & 0xe0;
638 tmp += 0x1f - ((z_cmf << 8) + tmp) % 0x1f;
639 png_ptr->zbuf[1] = (png_byte)tmp;
640 }
641 }
642
643 else
644 png_error(png_ptr,
645 "Invalid zlib compression method or flags in non-IDAT chunk");
646 }
647#endif /* PNG_WRITE_OPTIMIZE_CMF_SUPPORTED */
648
649 /* Write saved output buffers, if any */
650 for (i = 0; i < comp->num_output_ptr; i++)
651 {
652 png_write_chunk_data(png_ptr, comp->output_ptr[i],
653 (png_size_t)png_ptr->zbuf_size);
654
655 png_free(png_ptr, comp->output_ptr[i]);
656 }
657
658 if (comp->max_output_ptr != 0)
659 png_free(png_ptr, comp->output_ptr);
660
661 /* Write anything left in zbuf */
662 if (png_ptr->zstream.avail_out < (png_uint_32)png_ptr->zbuf_size)
663 png_write_chunk_data(png_ptr, png_ptr->zbuf,
664 (png_size_t)(png_ptr->zbuf_size - png_ptr->zstream.avail_out));
665
666 /* Reset zlib for another zTXt/iTXt or image data */
667 png_zlib_release(png_ptr);
668}
669#endif /* PNG_WRITE_COMPRESSED_TEXT_SUPPORTED */
670
671/* Write the IHDR chunk, and update the png_struct with the necessary
672 * information. Note that the rest of this code depends upon this
673 * information being correct.
674 */
675void /* PRIVATE */
676png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height,
677 int bit_depth, int color_type, int compression_type, int filter_type,
678 int interlace_type)
679{
680 png_byte buf[13]; /* Buffer to store the IHDR info */
681
682 png_debug(1, "in png_write_IHDR");
683
684 /* Check that we have valid input data from the application info */
685 switch (color_type)
686 {
687 case PNG_COLOR_TYPE_GRAY:
688 switch (bit_depth)
689 {
690 case 1:
691 case 2:
692 case 4:
693 case 8:
694#ifdef PNG_WRITE_16BIT_SUPPORTED
695 case 16:
696#endif
697 png_ptr->channels = 1; break;
698
699 default:
700 png_error(png_ptr,
701 "Invalid bit depth for grayscale image");
702 }
703 break;
704
705 case PNG_COLOR_TYPE_RGB:
706#ifdef PNG_WRITE_16BIT_SUPPORTED
707 if (bit_depth != 8 && bit_depth != 16)
708#else
709 if (bit_depth != 8)
710#endif
711 png_error(png_ptr, "Invalid bit depth for RGB image");
712
713 png_ptr->channels = 3;
714 break;
715
716 case PNG_COLOR_TYPE_PALETTE:
717 switch (bit_depth)
718 {
719 case 1:
720 case 2:
721 case 4:
722 case 8:
723 png_ptr->channels = 1;
724 break;
725
726 default:
727 png_error(png_ptr, "Invalid bit depth for paletted image");
728 }
729 break;
730
731 case PNG_COLOR_TYPE_GRAY_ALPHA:
732 if (bit_depth != 8 && bit_depth != 16)
733 png_error(png_ptr, "Invalid bit depth for grayscale+alpha image");
734
735 png_ptr->channels = 2;
736 break;
737
738 case PNG_COLOR_TYPE_RGB_ALPHA:
739#ifdef PNG_WRITE_16BIT_SUPPORTED
740 if (bit_depth != 8 && bit_depth != 16)
741#else
742 if (bit_depth != 8)
743#endif
744 png_error(png_ptr, "Invalid bit depth for RGBA image");
745
746 png_ptr->channels = 4;
747 break;
748
749 default:
750 png_error(png_ptr, "Invalid image color type specified");
751 }
752
753 if (compression_type != PNG_COMPRESSION_TYPE_BASE)
754 {
755 png_warning(png_ptr, "Invalid compression type specified");
756 compression_type = PNG_COMPRESSION_TYPE_BASE;
757 }
758
759 /* Write filter_method 64 (intrapixel differencing) only if
760 * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
761 * 2. Libpng did not write a PNG signature (this filter_method is only
762 * used in PNG datastreams that are embedded in MNG datastreams) and
763 * 3. The application called png_permit_mng_features with a mask that
764 * included PNG_FLAG_MNG_FILTER_64 and
765 * 4. The filter_method is 64 and
766 * 5. The color_type is RGB or RGBA
767 */
768 if (
769#ifdef PNG_MNG_FEATURES_SUPPORTED
770 !((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
771 ((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE) == 0) &&
772 (color_type == PNG_COLOR_TYPE_RGB ||
773 color_type == PNG_COLOR_TYPE_RGB_ALPHA) &&
774 (filter_type == PNG_INTRAPIXEL_DIFFERENCING)) &&
775#endif
776 filter_type != PNG_FILTER_TYPE_BASE)
777 {
778 png_warning(png_ptr, "Invalid filter type specified");
779 filter_type = PNG_FILTER_TYPE_BASE;
780 }
781
782#ifdef PNG_WRITE_INTERLACING_SUPPORTED
783 if (interlace_type != PNG_INTERLACE_NONE &&
784 interlace_type != PNG_INTERLACE_ADAM7)
785 {
786 png_warning(png_ptr, "Invalid interlace type specified");
787 interlace_type = PNG_INTERLACE_ADAM7;
788 }
789#else
790 interlace_type=PNG_INTERLACE_NONE;
791#endif
792
793 /* Save the relevent information */
794 png_ptr->bit_depth = (png_byte)bit_depth;
795 png_ptr->color_type = (png_byte)color_type;
796 png_ptr->interlaced = (png_byte)interlace_type;
797#ifdef PNG_MNG_FEATURES_SUPPORTED
798 png_ptr->filter_type = (png_byte)filter_type;
799#endif
800 png_ptr->compression_type = (png_byte)compression_type;
801 png_ptr->width = width;
802 png_ptr->height = height;
803
804 png_ptr->pixel_depth = (png_byte)(bit_depth * png_ptr->channels);
805 png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, width);
806 /* Set the usr info, so any transformations can modify it */
807 png_ptr->usr_width = png_ptr->width;
808 png_ptr->usr_bit_depth = png_ptr->bit_depth;
809 png_ptr->usr_channels = png_ptr->channels;
810
811 /* Pack the header information into the buffer */
812 png_save_uint_32(buf, width);
813 png_save_uint_32(buf + 4, height);
814 buf[8] = (png_byte)bit_depth;
815 buf[9] = (png_byte)color_type;
816 buf[10] = (png_byte)compression_type;
817 buf[11] = (png_byte)filter_type;
818 buf[12] = (png_byte)interlace_type;
819
820 /* Write the chunk */
821 png_write_complete_chunk(png_ptr, png_IHDR, buf, (png_size_t)13);
822
823 /* Initialize zlib with PNG info */
824 png_ptr->zstream.zalloc = png_zalloc;
825 png_ptr->zstream.zfree = png_zfree;
826 png_ptr->zstream.opaque = (voidpf)png_ptr;
827
828 if (!(png_ptr->do_filter))
829 {
830 if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE ||
831 png_ptr->bit_depth < 8)
832 png_ptr->do_filter = PNG_FILTER_NONE;
833
834 else
835 png_ptr->do_filter = PNG_ALL_FILTERS;
836 }
837
838 if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_STRATEGY))
839 {
840 if (png_ptr->do_filter != PNG_FILTER_NONE)
841 png_ptr->zlib_strategy = Z_FILTERED;
842
843 else
844 png_ptr->zlib_strategy = Z_DEFAULT_STRATEGY;
845 }
846
847 if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_LEVEL))
848 png_ptr->zlib_level = Z_DEFAULT_COMPRESSION;
849
850 if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL))
851 png_ptr->zlib_mem_level = 8;
852
853 if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS))
854 png_ptr->zlib_window_bits = 15;
855
856 if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_METHOD))
857 png_ptr->zlib_method = 8;
858
859#ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
860#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
861 if (!(png_ptr->flags & PNG_FLAG_ZTXT_CUSTOM_STRATEGY))
862 png_ptr->zlib_text_strategy = Z_DEFAULT_STRATEGY;
863
864 if (!(png_ptr->flags & PNG_FLAG_ZTXT_CUSTOM_LEVEL))
865 png_ptr->zlib_text_level = png_ptr->zlib_level;
866
867 if (!(png_ptr->flags & PNG_FLAG_ZTXT_CUSTOM_MEM_LEVEL))
868 png_ptr->zlib_text_mem_level = png_ptr->zlib_mem_level;
869
870 if (!(png_ptr->flags & PNG_FLAG_ZTXT_CUSTOM_WINDOW_BITS))
871 png_ptr->zlib_text_window_bits = png_ptr->zlib_window_bits;
872
873 if (!(png_ptr->flags & PNG_FLAG_ZTXT_CUSTOM_METHOD))
874 png_ptr->zlib_text_method = png_ptr->zlib_method;
875#else
876 png_ptr->zlib_text_strategy = Z_DEFAULT_STRATEGY;
877 png_ptr->zlib_text_level = png_ptr->zlib_level;
878 png_ptr->zlib_text_mem_level = png_ptr->zlib_mem_level;
879 png_ptr->zlib_text_window_bits = png_ptr->zlib_window_bits;
880 png_ptr->zlib_text_method = png_ptr->zlib_method;
881#endif /* PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED */
882#endif /* PNG_WRITE_COMPRESSED_TEXT_SUPPORTED */
883
884 /* Record that the compressor has not yet been initialized. */
885 png_ptr->zlib_state = PNG_ZLIB_UNINITIALIZED;
886
887 png_ptr->mode = PNG_HAVE_IHDR; /* not READY_FOR_ZTXT */
888}
889
890/* Write the palette. We are careful not to trust png_color to be in the
891 * correct order for PNG, so people can redefine it to any convenient
892 * structure.
893 */
894void /* PRIVATE */
895png_write_PLTE(png_structp png_ptr, png_const_colorp palette,
896 png_uint_32 num_pal)
897{
898 png_uint_32 i;
899 png_const_colorp pal_ptr;
900 png_byte buf[3];
901
902 png_debug(1, "in png_write_PLTE");
903
904 if ((
905#ifdef PNG_MNG_FEATURES_SUPPORTED
906 !(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) &&
907#endif
908 num_pal == 0) || num_pal > 256)
909 {
910 if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
911 {
912 png_error(png_ptr, "Invalid number of colors in palette");
913 }
914
915 else
916 {
917 png_warning(png_ptr, "Invalid number of colors in palette");
918 return;
919 }
920 }
921
922 if (!(png_ptr->color_type&PNG_COLOR_MASK_COLOR))
923 {
924 png_warning(png_ptr,
925 "Ignoring request to write a PLTE chunk in grayscale PNG");
926
927 return;
928 }
929
930 png_ptr->num_palette = (png_uint_16)num_pal;
931 png_debug1(3, "num_palette = %d", png_ptr->num_palette);
932
933 png_write_chunk_header(png_ptr, png_PLTE, (png_uint_32)(num_pal * 3));
934#ifdef PNG_POINTER_INDEXING_SUPPORTED
935
936 for (i = 0, pal_ptr = palette; i < num_pal; i++, pal_ptr++)
937 {
938 buf[0] = pal_ptr->red;
939 buf[1] = pal_ptr->green;
940 buf[2] = pal_ptr->blue;
941 png_write_chunk_data(png_ptr, buf, (png_size_t)3);
942 }
943
944#else
945 /* This is a little slower but some buggy compilers need to do this
946 * instead
947 */
948 pal_ptr=palette;
949
950 for (i = 0; i < num_pal; i++)
951 {
952 buf[0] = pal_ptr[i].red;
953 buf[1] = pal_ptr[i].green;
954 buf[2] = pal_ptr[i].blue;
955 png_write_chunk_data(png_ptr, buf, (png_size_t)3);
956 }
957
958#endif
959 png_write_chunk_end(png_ptr);
960 png_ptr->mode |= PNG_HAVE_PLTE;
961}
962
963/* Write an IDAT chunk */
964void /* PRIVATE */
965png_write_IDAT(png_structp png_ptr, png_bytep data, png_size_t length)
966{
967 png_debug(1, "in png_write_IDAT");
968
969#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED
970 if (!(png_ptr->mode & PNG_HAVE_IDAT) &&
971 png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE)
972 {
973 /* Optimize the CMF field in the zlib stream. This hack of the zlib
974 * stream is compliant to the stream specification.
975 */
976 unsigned int z_cmf = data[0]; /* zlib compression method and flags */
977
978 if ((z_cmf & 0x0f) == 8 && (z_cmf & 0xf0) <= 0x70)
979 {
980 /* Avoid memory underflows and multiplication overflows.
981 *
982 * The conditions below are practically always satisfied;
983 * however, they still must be checked.
984 */
985 if (length >= 2 &&
986 png_ptr->height < 16384 && png_ptr->width < 16384)
987 {
988 /* Compute the maximum possible length of the datastream */
989
990 /* Number of pixels, plus for each row a filter byte
991 * and possibly a padding byte, so increase the maximum
992 * size to account for these.
993 */
994 unsigned int z_cinfo;
995 unsigned int half_z_window_size;
996 png_uint_32 uncompressed_idat_size = png_ptr->height *
997 ((png_ptr->width *
998 png_ptr->channels * png_ptr->bit_depth + 15) >> 3);
999
1000 /* If it's interlaced, each block of 8 rows is sent as up to
1001 * 14 rows, i.e., 6 additional rows, each with a filter byte
1002 * and possibly a padding byte
1003 */
1004 if (png_ptr->interlaced)
1005 uncompressed_idat_size += ((png_ptr->height + 7)/8) *
1006 (png_ptr->bit_depth < 8 ? 12 : 6);
1007
1008 z_cinfo = z_cmf >> 4;
1009 half_z_window_size = 1 << (z_cinfo + 7);
1010
1011 while (uncompressed_idat_size <= half_z_window_size &&
1012 half_z_window_size >= 256)
1013 {
1014 z_cinfo--;
1015 half_z_window_size >>= 1;
1016 }
1017
1018 z_cmf = (z_cmf & 0x0f) | (z_cinfo << 4);
1019
1020 if (data[0] != z_cmf)
1021 {
1022 int tmp;
1023 data[0] = (png_byte)z_cmf;
1024 tmp = data[1] & 0xe0;
1025 tmp += 0x1f - ((z_cmf << 8) + tmp) % 0x1f;
1026 data[1] = (png_byte)tmp;
1027 }
1028 }
1029 }
1030
1031 else
1032 png_error(png_ptr,
1033 "Invalid zlib compression method or flags in IDAT");
1034 }
1035#endif /* PNG_WRITE_OPTIMIZE_CMF_SUPPORTED */
1036
1037 png_write_complete_chunk(png_ptr, png_IDAT, data, length);
1038 png_ptr->mode |= PNG_HAVE_IDAT;
1039
1040 /* Prior to 1.5.4 this code was replicated in every caller (except at the
1041 * end, where it isn't technically necessary). Since this function has
1042 * flushed the data we can safely reset the zlib output buffer here.
1043 */
1044 png_ptr->zstream.next_out = png_ptr->zbuf;
1045 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
1046}
1047
1048/* Write an IEND chunk */
1049void /* PRIVATE */
1050png_write_IEND(png_structp png_ptr)
1051{
1052 png_debug(1, "in png_write_IEND");
1053
1054 png_write_complete_chunk(png_ptr, png_IEND, NULL, (png_size_t)0);
1055 png_ptr->mode |= PNG_HAVE_IEND;
1056}
1057
1058#ifdef PNG_WRITE_gAMA_SUPPORTED
1059/* Write a gAMA chunk */
1060void /* PRIVATE */
1061png_write_gAMA_fixed(png_structp png_ptr, png_fixed_point file_gamma)
1062{
1063 png_byte buf[4];
1064
1065 png_debug(1, "in png_write_gAMA");
1066
1067 /* file_gamma is saved in 1/100,000ths */
1068 png_save_uint_32(buf, (png_uint_32)file_gamma);
1069 png_write_complete_chunk(png_ptr, png_gAMA, buf, (png_size_t)4);
1070}
1071#endif
1072
1073#ifdef PNG_WRITE_sRGB_SUPPORTED
1074/* Write a sRGB chunk */
1075void /* PRIVATE */
1076png_write_sRGB(png_structp png_ptr, int srgb_intent)
1077{
1078 png_byte buf[1];
1079
1080 png_debug(1, "in png_write_sRGB");
1081
1082 if (srgb_intent >= PNG_sRGB_INTENT_LAST)
1083 png_warning(png_ptr,
1084 "Invalid sRGB rendering intent specified");
1085
1086 buf[0]=(png_byte)srgb_intent;
1087 png_write_complete_chunk(png_ptr, png_sRGB, buf, (png_size_t)1);
1088}
1089#endif
1090
1091#ifdef PNG_WRITE_iCCP_SUPPORTED
1092/* Write an iCCP chunk */
1093void /* PRIVATE */
1094png_write_iCCP(png_structp png_ptr, png_const_charp name, int compression_type,
1095 png_const_charp profile, int profile_len)
1096{
1097 png_size_t name_len;
1098 png_charp new_name;
1099 compression_state comp;
1100 int embedded_profile_len = 0;
1101
1102 png_debug(1, "in png_write_iCCP");
1103
1104 comp.num_output_ptr = 0;
1105 comp.max_output_ptr = 0;
1106 comp.output_ptr = NULL;
1107 comp.input = NULL;
1108 comp.input_len = 0;
1109
1110 if ((name_len = png_check_keyword(png_ptr, name, &new_name)) == 0)
1111 return;
1112
1113 if (compression_type != PNG_COMPRESSION_TYPE_BASE)
1114 png_warning(png_ptr, "Unknown compression type in iCCP chunk");
1115
1116 if (profile == NULL)
1117 profile_len = 0;
1118
1119 if (profile_len > 3)
1120 embedded_profile_len =
1121 ((*( (png_const_bytep)profile ))<<24) |
1122 ((*( (png_const_bytep)profile + 1))<<16) |
1123 ((*( (png_const_bytep)profile + 2))<< 8) |
1124 ((*( (png_const_bytep)profile + 3)) );
1125
1126 if (embedded_profile_len < 0)
1127 {
1128 png_warning(png_ptr,
1129 "Embedded profile length in iCCP chunk is negative");
1130
1131 png_free(png_ptr, new_name);
1132 return;
1133 }
1134
1135 if (profile_len < embedded_profile_len)
1136 {
1137 png_warning(png_ptr,
1138 "Embedded profile length too large in iCCP chunk");
1139
1140 png_free(png_ptr, new_name);
1141 return;
1142 }
1143
1144 if (profile_len > embedded_profile_len)
1145 {
1146 png_warning(png_ptr,
1147 "Truncating profile to actual length in iCCP chunk");
1148
1149 profile_len = embedded_profile_len;
1150 }
1151
1152 if (profile_len)
1153 profile_len = png_text_compress(png_ptr, profile,
1154 (png_size_t)profile_len, PNG_COMPRESSION_TYPE_BASE, &comp);
1155
1156 /* Make sure we include the NULL after the name and the compression type */
1157 png_write_chunk_header(png_ptr, png_iCCP,
1158 (png_uint_32)(name_len + profile_len + 2));
1159
1160 new_name[name_len + 1] = 0x00;
1161
1162 png_write_chunk_data(png_ptr, (png_bytep)new_name,
1163 (png_size_t)(name_len + 2));
1164
1165 if (profile_len)
1166 {
1167 comp.input_len = profile_len;
1168 png_write_compressed_data_out(png_ptr, &comp);
1169 }
1170
1171 png_write_chunk_end(png_ptr);
1172 png_free(png_ptr, new_name);
1173}
1174#endif
1175
1176#ifdef PNG_WRITE_sPLT_SUPPORTED
1177/* Write a sPLT chunk */
1178void /* PRIVATE */
1179png_write_sPLT(png_structp png_ptr, png_const_sPLT_tp spalette)
1180{
1181 png_size_t name_len;
1182 png_charp new_name;
1183 png_byte entrybuf[10];
1184 png_size_t entry_size = (spalette->depth == 8 ? 6 : 10);
1185 png_size_t palette_size = entry_size * spalette->nentries;
1186 png_sPLT_entryp ep;
1187#ifndef PNG_POINTER_INDEXING_SUPPORTED
1188 int i;
1189#endif
1190
1191 png_debug(1, "in png_write_sPLT");
1192
1193 if ((name_len = png_check_keyword(png_ptr,spalette->name, &new_name))==0)
1194 return;
1195
1196 /* Make sure we include the NULL after the name */
1197 png_write_chunk_header(png_ptr, png_sPLT,
1198 (png_uint_32)(name_len + 2 + palette_size));
1199
1200 png_write_chunk_data(png_ptr, (png_bytep)new_name,
1201 (png_size_t)(name_len + 1));
1202
1203 png_write_chunk_data(png_ptr, &spalette->depth, (png_size_t)1);
1204
1205 /* Loop through each palette entry, writing appropriately */
1206#ifdef PNG_POINTER_INDEXING_SUPPORTED
1207 for (ep = spalette->entries; ep<spalette->entries + spalette->nentries; ep++)
1208 {
1209 if (spalette->depth == 8)
1210 {
1211 entrybuf[0] = (png_byte)ep->red;
1212 entrybuf[1] = (png_byte)ep->green;
1213 entrybuf[2] = (png_byte)ep->blue;
1214 entrybuf[3] = (png_byte)ep->alpha;
1215 png_save_uint_16(entrybuf + 4, ep->frequency);
1216 }
1217
1218 else
1219 {
1220 png_save_uint_16(entrybuf + 0, ep->red);
1221 png_save_uint_16(entrybuf + 2, ep->green);
1222 png_save_uint_16(entrybuf + 4, ep->blue);
1223 png_save_uint_16(entrybuf + 6, ep->alpha);
1224 png_save_uint_16(entrybuf + 8, ep->frequency);
1225 }
1226
1227 png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size);
1228 }
1229#else
1230 ep=spalette->entries;
1231 for (i = 0; i>spalette->nentries; i++)
1232 {
1233 if (spalette->depth == 8)
1234 {
1235 entrybuf[0] = (png_byte)ep[i].red;
1236 entrybuf[1] = (png_byte)ep[i].green;
1237 entrybuf[2] = (png_byte)ep[i].blue;
1238 entrybuf[3] = (png_byte)ep[i].alpha;
1239 png_save_uint_16(entrybuf + 4, ep[i].frequency);
1240 }
1241
1242 else
1243 {
1244 png_save_uint_16(entrybuf + 0, ep[i].red);
1245 png_save_uint_16(entrybuf + 2, ep[i].green);
1246 png_save_uint_16(entrybuf + 4, ep[i].blue);
1247 png_save_uint_16(entrybuf + 6, ep[i].alpha);
1248 png_save_uint_16(entrybuf + 8, ep[i].frequency);
1249 }
1250
1251 png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size);
1252 }
1253#endif
1254
1255 png_write_chunk_end(png_ptr);
1256 png_free(png_ptr, new_name);
1257}
1258#endif
1259
1260#ifdef PNG_WRITE_sBIT_SUPPORTED
1261/* Write the sBIT chunk */
1262void /* PRIVATE */
1263png_write_sBIT(png_structp png_ptr, png_const_color_8p sbit, int color_type)
1264{
1265 png_byte buf[4];
1266 png_size_t size;
1267
1268 png_debug(1, "in png_write_sBIT");
1269
1270 /* Make sure we don't depend upon the order of PNG_COLOR_8 */
1271 if (color_type & PNG_COLOR_MASK_COLOR)
1272 {
1273 png_byte maxbits;
1274
1275 maxbits = (png_byte)(color_type==PNG_COLOR_TYPE_PALETTE ? 8 :
1276 png_ptr->usr_bit_depth);
1277
1278 if (sbit->red == 0 || sbit->red > maxbits ||
1279 sbit->green == 0 || sbit->green > maxbits ||
1280 sbit->blue == 0 || sbit->blue > maxbits)
1281 {
1282 png_warning(png_ptr, "Invalid sBIT depth specified");
1283 return;
1284 }
1285
1286 buf[0] = sbit->red;
1287 buf[1] = sbit->green;
1288 buf[2] = sbit->blue;
1289 size = 3;
1290 }
1291
1292 else
1293 {
1294 if (sbit->gray == 0 || sbit->gray > png_ptr->usr_bit_depth)
1295 {
1296 png_warning(png_ptr, "Invalid sBIT depth specified");
1297 return;
1298 }
1299
1300 buf[0] = sbit->gray;
1301 size = 1;
1302 }
1303
1304 if (color_type & PNG_COLOR_MASK_ALPHA)
1305 {
1306 if (sbit->alpha == 0 || sbit->alpha > png_ptr->usr_bit_depth)
1307 {
1308 png_warning(png_ptr, "Invalid sBIT depth specified");
1309 return;
1310 }
1311
1312 buf[size++] = sbit->alpha;
1313 }
1314
1315 png_write_complete_chunk(png_ptr, png_sBIT, buf, size);
1316}
1317#endif
1318
1319#ifdef PNG_WRITE_cHRM_SUPPORTED
1320/* Write the cHRM chunk */
1321void /* PRIVATE */
1322png_write_cHRM_fixed(png_structp png_ptr, png_fixed_point white_x,
1323 png_fixed_point white_y, png_fixed_point red_x, png_fixed_point red_y,
1324 png_fixed_point green_x, png_fixed_point green_y, png_fixed_point blue_x,
1325 png_fixed_point blue_y)
1326{
1327 png_byte buf[32];
1328
1329 png_debug(1, "in png_write_cHRM");
1330
1331 /* Each value is saved in 1/100,000ths */
1332#ifdef PNG_CHECK_cHRM_SUPPORTED
1333 if (png_check_cHRM_fixed(png_ptr, white_x, white_y, red_x, red_y,
1334 green_x, green_y, blue_x, blue_y))
1335#endif
1336 {
1337 png_save_uint_32(buf, (png_uint_32)white_x);
1338 png_save_uint_32(buf + 4, (png_uint_32)white_y);
1339
1340 png_save_uint_32(buf + 8, (png_uint_32)red_x);
1341 png_save_uint_32(buf + 12, (png_uint_32)red_y);
1342
1343 png_save_uint_32(buf + 16, (png_uint_32)green_x);
1344 png_save_uint_32(buf + 20, (png_uint_32)green_y);
1345
1346 png_save_uint_32(buf + 24, (png_uint_32)blue_x);
1347 png_save_uint_32(buf + 28, (png_uint_32)blue_y);
1348
1349 png_write_complete_chunk(png_ptr, png_cHRM, buf, (png_size_t)32);
1350 }
1351}
1352#endif
1353
1354#ifdef PNG_WRITE_tRNS_SUPPORTED
1355/* Write the tRNS chunk */
1356void /* PRIVATE */
1357png_write_tRNS(png_structp png_ptr, png_const_bytep trans_alpha,
1358 png_const_color_16p tran, int num_trans, int color_type)
1359{
1360 png_byte buf[6];
1361
1362 png_debug(1, "in png_write_tRNS");
1363
1364 if (color_type == PNG_COLOR_TYPE_PALETTE)
1365 {
1366 if (num_trans <= 0 || num_trans > (int)png_ptr->num_palette)
1367 {
1368 png_warning(png_ptr, "Invalid number of transparent colors specified");
1369 return;
1370 }
1371
1372 /* Write the chunk out as it is */
1373 png_write_complete_chunk(png_ptr, png_tRNS, trans_alpha, (png_size_t)num_trans);
1374 }
1375
1376 else if (color_type == PNG_COLOR_TYPE_GRAY)
1377 {
1378 /* One 16 bit value */
1379 if (tran->gray >= (1 << png_ptr->bit_depth))
1380 {
1381 png_warning(png_ptr,
1382 "Ignoring attempt to write tRNS chunk out-of-range for bit_depth");
1383
1384 return;
1385 }
1386
1387 png_save_uint_16(buf, tran->gray);
1388 png_write_complete_chunk(png_ptr, png_tRNS, buf, (png_size_t)2);
1389 }
1390
1391 else if (color_type == PNG_COLOR_TYPE_RGB)
1392 {
1393 /* Three 16 bit values */
1394 png_save_uint_16(buf, tran->red);
1395 png_save_uint_16(buf + 2, tran->green);
1396 png_save_uint_16(buf + 4, tran->blue);
1397#ifdef PNG_WRITE_16BIT_SUPPORTED
1398 if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]))
1399#else
1400 if (buf[0] | buf[2] | buf[4])
1401#endif
1402 {
1403 png_warning(png_ptr,
1404 "Ignoring attempt to write 16-bit tRNS chunk when bit_depth is 8");
1405 return;
1406 }
1407
1408 png_write_complete_chunk(png_ptr, png_tRNS, buf, (png_size_t)6);
1409 }
1410
1411 else
1412 {
1413 png_warning(png_ptr, "Can't write tRNS with an alpha channel");
1414 }
1415}
1416#endif
1417
1418#ifdef PNG_WRITE_bKGD_SUPPORTED
1419/* Write the background chunk */
1420void /* PRIVATE */
1421png_write_bKGD(png_structp png_ptr, png_const_color_16p back, int color_type)
1422{
1423 png_byte buf[6];
1424
1425 png_debug(1, "in png_write_bKGD");
1426
1427 if (color_type == PNG_COLOR_TYPE_PALETTE)
1428 {
1429 if (
1430#ifdef PNG_MNG_FEATURES_SUPPORTED
1431 (png_ptr->num_palette ||
1432 (!(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE))) &&
1433#endif
1434 back->index >= png_ptr->num_palette)
1435 {
1436 png_warning(png_ptr, "Invalid background palette index");
1437 return;
1438 }
1439
1440 buf[0] = back->index;
1441 png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)1);
1442 }
1443
1444 else if (color_type & PNG_COLOR_MASK_COLOR)
1445 {
1446 png_save_uint_16(buf, back->red);
1447 png_save_uint_16(buf + 2, back->green);
1448 png_save_uint_16(buf + 4, back->blue);
1449#ifdef PNG_WRITE_16BIT_SUPPORTED
1450 if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]))
1451#else
1452 if (buf[0] | buf[2] | buf[4])
1453#endif
1454 {
1455 png_warning(png_ptr,
1456 "Ignoring attempt to write 16-bit bKGD chunk when bit_depth is 8");
1457
1458 return;
1459 }
1460
1461 png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)6);
1462 }
1463
1464 else
1465 {
1466 if (back->gray >= (1 << png_ptr->bit_depth))
1467 {
1468 png_warning(png_ptr,
1469 "Ignoring attempt to write bKGD chunk out-of-range for bit_depth");
1470
1471 return;
1472 }
1473
1474 png_save_uint_16(buf, back->gray);
1475 png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)2);
1476 }
1477}
1478#endif
1479
1480#ifdef PNG_WRITE_hIST_SUPPORTED
1481/* Write the histogram */
1482void /* PRIVATE */
1483png_write_hIST(png_structp png_ptr, png_const_uint_16p hist, int num_hist)
1484{
1485 int i;
1486 png_byte buf[3];
1487
1488 png_debug(1, "in png_write_hIST");
1489
1490 if (num_hist > (int)png_ptr->num_palette)
1491 {
1492 png_debug2(3, "num_hist = %d, num_palette = %d", num_hist,
1493 png_ptr->num_palette);
1494
1495 png_warning(png_ptr, "Invalid number of histogram entries specified");
1496 return;
1497 }
1498
1499 png_write_chunk_header(png_ptr, png_hIST, (png_uint_32)(num_hist * 2));
1500
1501 for (i = 0; i < num_hist; i++)
1502 {
1503 png_save_uint_16(buf, hist[i]);
1504 png_write_chunk_data(png_ptr, buf, (png_size_t)2);
1505 }
1506
1507 png_write_chunk_end(png_ptr);
1508}
1509#endif
1510
1511#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \
1512 defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
1513/* Check that the tEXt or zTXt keyword is valid per PNG 1.0 specification,
1514 * and if invalid, correct the keyword rather than discarding the entire
1515 * chunk. The PNG 1.0 specification requires keywords 1-79 characters in
1516 * length, forbids leading or trailing whitespace, multiple internal spaces,
1517 * and the non-break space (0x80) from ISO 8859-1. Returns keyword length.
1518 *
1519 * The new_key is allocated to hold the corrected keyword and must be freed
1520 * by the calling routine. This avoids problems with trying to write to
1521 * static keywords without having to have duplicate copies of the strings.
1522 */
1523png_size_t /* PRIVATE */
1524png_check_keyword(png_structp png_ptr, png_const_charp key, png_charpp new_key)
1525{
1526 png_size_t key_len;
1527 png_const_charp ikp;
1528 png_charp kp, dp;
1529 int kflag;
1530 int kwarn=0;
1531
1532 png_debug(1, "in png_check_keyword");
1533
1534 *new_key = NULL;
1535
1536 if (key == NULL || (key_len = png_strlen(key)) == 0)
1537 {
1538 png_warning(png_ptr, "zero length keyword");
1539 return ((png_size_t)0);
1540 }
1541
1542 png_debug1(2, "Keyword to be checked is '%s'", key);
1543
1544 *new_key = (png_charp)png_malloc_warn(png_ptr, (png_uint_32)(key_len + 2));
1545
1546 if (*new_key == NULL)
1547 {
1548 png_warning(png_ptr, "Out of memory while procesing keyword");
1549 return ((png_size_t)0);
1550 }
1551
1552 /* Replace non-printing characters with a blank and print a warning */
1553 for (ikp = key, dp = *new_key; *ikp != '\0'; ikp++, dp++)
1554 {
1555 if ((png_byte)*ikp < 0x20 ||
1556 ((png_byte)*ikp > 0x7E && (png_byte)*ikp < 0xA1))
1557 {
1558 PNG_WARNING_PARAMETERS(p)
1559
1560 png_warning_parameter_unsigned(p, 1, PNG_NUMBER_FORMAT_02x,
1561 (png_byte)*ikp);
1562 png_formatted_warning(png_ptr, p, "invalid keyword character 0x@1");
1563 *dp = ' ';
1564 }
1565
1566 else
1567 {
1568 *dp = *ikp;
1569 }
1570 }
1571 *dp = '\0';
1572
1573 /* Remove any trailing white space. */
1574 kp = *new_key + key_len - 1;
1575 if (*kp == ' ')
1576 {
1577 png_warning(png_ptr, "trailing spaces removed from keyword");
1578
1579 while (*kp == ' ')
1580 {
1581 *(kp--) = '\0';
1582 key_len--;
1583 }
1584 }
1585
1586 /* Remove any leading white space. */
1587 kp = *new_key;
1588 if (*kp == ' ')
1589 {
1590 png_warning(png_ptr, "leading spaces removed from keyword");
1591
1592 while (*kp == ' ')
1593 {
1594 kp++;
1595 key_len--;
1596 }
1597 }
1598
1599 png_debug1(2, "Checking for multiple internal spaces in '%s'", kp);
1600
1601 /* Remove multiple internal spaces. */
1602 for (kflag = 0, dp = *new_key; *kp != '\0'; kp++)
1603 {
1604 if (*kp == ' ' && kflag == 0)
1605 {
1606 *(dp++) = *kp;
1607 kflag = 1;
1608 }
1609
1610 else if (*kp == ' ')
1611 {
1612 key_len--;
1613 kwarn = 1;
1614 }
1615
1616 else
1617 {
1618 *(dp++) = *kp;
1619 kflag = 0;
1620 }
1621 }
1622 *dp = '\0';
1623 if (kwarn)
1624 png_warning(png_ptr, "extra interior spaces removed from keyword");
1625
1626 if (key_len == 0)
1627 {
1628 png_free(png_ptr, *new_key);
1629 png_warning(png_ptr, "Zero length keyword");
1630 }
1631
1632 if (key_len > 79)
1633 {
1634 png_warning(png_ptr, "keyword length must be 1 - 79 characters");
1635 (*new_key)[79] = '\0';
1636 key_len = 79;
1637 }
1638
1639 return (key_len);
1640}
1641#endif
1642
1643#ifdef PNG_WRITE_tEXt_SUPPORTED
1644/* Write a tEXt chunk */
1645void /* PRIVATE */
1646png_write_tEXt(png_structp png_ptr, png_const_charp key, png_const_charp text,
1647 png_size_t text_len)
1648{
1649 png_size_t key_len;
1650 png_charp new_key;
1651
1652 png_debug(1, "in png_write_tEXt");
1653
1654 if ((key_len = png_check_keyword(png_ptr, key, &new_key))==0)
1655 return;
1656
1657 if (text == NULL || *text == '\0')
1658 text_len = 0;
1659
1660 else
1661 text_len = png_strlen(text);
1662
1663 /* Make sure we include the 0 after the key */
1664 png_write_chunk_header(png_ptr, png_tEXt,
1665 (png_uint_32)(key_len + text_len + 1));
1666 /*
1667 * We leave it to the application to meet PNG-1.0 requirements on the
1668 * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of
1669 * any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them.
1670 * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.
1671 */
1672 png_write_chunk_data(png_ptr, (png_bytep)new_key,
1673 (png_size_t)(key_len + 1));
1674
1675 if (text_len)
1676 png_write_chunk_data(png_ptr, (png_const_bytep)text,
1677 (png_size_t)text_len);
1678
1679 png_write_chunk_end(png_ptr);
1680 png_free(png_ptr, new_key);
1681}
1682#endif
1683
1684#ifdef PNG_WRITE_zTXt_SUPPORTED
1685/* Write a compressed text chunk */
1686void /* PRIVATE */
1687png_write_zTXt(png_structp png_ptr, png_const_charp key, png_const_charp text,
1688 png_size_t text_len, int compression)
1689{
1690 png_size_t key_len;
1691 png_byte buf;
1692 png_charp new_key;
1693 compression_state comp;
1694
1695 png_debug(1, "in png_write_zTXt");
1696
1697 comp.num_output_ptr = 0;
1698 comp.max_output_ptr = 0;
1699 comp.output_ptr = NULL;
1700 comp.input = NULL;
1701 comp.input_len = 0;
1702
1703 if ((key_len = png_check_keyword(png_ptr, key, &new_key)) == 0)
1704 {
1705 png_free(png_ptr, new_key);
1706 return;
1707 }
1708
1709 if (text == NULL || *text == '\0' || compression==PNG_TEXT_COMPRESSION_NONE)
1710 {
1711 png_write_tEXt(png_ptr, new_key, text, (png_size_t)0);
1712 png_free(png_ptr, new_key);
1713 return;
1714 }
1715
1716 text_len = png_strlen(text);
1717
1718 /* Compute the compressed data; do it now for the length */
1719 text_len = png_text_compress(png_ptr, text, text_len, compression,
1720 &comp);
1721
1722 /* Write start of chunk */
1723 png_write_chunk_header(png_ptr, png_zTXt,
1724 (png_uint_32)(key_len+text_len + 2));
1725
1726 /* Write key */
1727 png_write_chunk_data(png_ptr, (png_bytep)new_key,
1728 (png_size_t)(key_len + 1));
1729
1730 png_free(png_ptr, new_key);
1731
1732 buf = (png_byte)compression;
1733
1734 /* Write compression */
1735 png_write_chunk_data(png_ptr, &buf, (png_size_t)1);
1736
1737 /* Write the compressed data */
1738 comp.input_len = text_len;
1739 png_write_compressed_data_out(png_ptr, &comp);
1740
1741 /* Close the chunk */
1742 png_write_chunk_end(png_ptr);
1743}
1744#endif
1745
1746#ifdef PNG_WRITE_iTXt_SUPPORTED
1747/* Write an iTXt chunk */
1748void /* PRIVATE */
1749png_write_iTXt(png_structp png_ptr, int compression, png_const_charp key,
1750 png_const_charp lang, png_const_charp lang_key, png_const_charp text)
1751{
1752 png_size_t lang_len, key_len, lang_key_len, text_len;
1753 png_charp new_lang;
1754 png_charp new_key = NULL;
1755 png_byte cbuf[2];
1756 compression_state comp;
1757
1758 png_debug(1, "in png_write_iTXt");
1759
1760 comp.num_output_ptr = 0;
1761 comp.max_output_ptr = 0;
1762 comp.output_ptr = NULL;
1763 comp.input = NULL;
1764
1765 if ((key_len = png_check_keyword(png_ptr, key, &new_key)) == 0)
1766 return;
1767
1768 if ((lang_len = png_check_keyword(png_ptr, lang, &new_lang)) == 0)
1769 {
1770 png_warning(png_ptr, "Empty language field in iTXt chunk");
1771 new_lang = NULL;
1772 lang_len = 0;
1773 }
1774
1775 if (lang_key == NULL)
1776 lang_key_len = 0;
1777
1778 else
1779 lang_key_len = png_strlen(lang_key);
1780
1781 if (text == NULL)
1782 text_len = 0;
1783
1784 else
1785 text_len = png_strlen(text);
1786
1787 /* Compute the compressed data; do it now for the length */
1788 text_len = png_text_compress(png_ptr, text, text_len, compression - 2,
1789 &comp);
1790
1791
1792 /* Make sure we include the compression flag, the compression byte,
1793 * and the NULs after the key, lang, and lang_key parts
1794 */
1795
1796 png_write_chunk_header(png_ptr, png_iTXt, (png_uint_32)(
1797 5 /* comp byte, comp flag, terminators for key, lang and lang_key */
1798 + key_len
1799 + lang_len
1800 + lang_key_len
1801 + text_len));
1802
1803 /* We leave it to the application to meet PNG-1.0 requirements on the
1804 * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of
1805 * any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them.
1806 * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.
1807 */
1808 png_write_chunk_data(png_ptr, (png_bytep)new_key, (png_size_t)(key_len + 1));
1809
1810 /* Set the compression flag */
1811 if (compression == PNG_ITXT_COMPRESSION_NONE ||
1812 compression == PNG_TEXT_COMPRESSION_NONE)
1813 cbuf[0] = 0;
1814
1815 else /* compression == PNG_ITXT_COMPRESSION_zTXt */
1816 cbuf[0] = 1;
1817
1818 /* Set the compression method */
1819 cbuf[1] = 0;
1820
1821 png_write_chunk_data(png_ptr, cbuf, (png_size_t)2);
1822
1823 cbuf[0] = 0;
1824 png_write_chunk_data(png_ptr, (new_lang ? (png_const_bytep)new_lang : cbuf),
1825 (png_size_t)(lang_len + 1));
1826
1827 png_write_chunk_data(png_ptr, (lang_key ? (png_const_bytep)lang_key : cbuf),
1828 (png_size_t)(lang_key_len + 1));
1829
1830 png_write_compressed_data_out(png_ptr, &comp);
1831
1832 png_write_chunk_end(png_ptr);
1833
1834 png_free(png_ptr, new_key);
1835 png_free(png_ptr, new_lang);
1836}
1837#endif
1838
1839#ifdef PNG_WRITE_oFFs_SUPPORTED
1840/* Write the oFFs chunk */
1841void /* PRIVATE */
1842png_write_oFFs(png_structp png_ptr, png_int_32 x_offset, png_int_32 y_offset,
1843 int unit_type)
1844{
1845 png_byte buf[9];
1846
1847 png_debug(1, "in png_write_oFFs");
1848
1849 if (unit_type >= PNG_OFFSET_LAST)
1850 png_warning(png_ptr, "Unrecognized unit type for oFFs chunk");
1851
1852 png_save_int_32(buf, x_offset);
1853 png_save_int_32(buf + 4, y_offset);
1854 buf[8] = (png_byte)unit_type;
1855
1856 png_write_complete_chunk(png_ptr, png_oFFs, buf, (png_size_t)9);
1857}
1858#endif
1859#ifdef PNG_WRITE_pCAL_SUPPORTED
1860/* Write the pCAL chunk (described in the PNG extensions document) */
1861void /* PRIVATE */
1862png_write_pCAL(png_structp png_ptr, png_charp purpose, png_int_32 X0,
1863 png_int_32 X1, int type, int nparams, png_const_charp units,
1864 png_charpp params)
1865{
1866 png_size_t purpose_len, units_len, total_len;
1867 png_size_tp params_len;
1868 png_byte buf[10];
1869 png_charp new_purpose;
1870 int i;
1871
1872 png_debug1(1, "in png_write_pCAL (%d parameters)", nparams);
1873
1874 if (type >= PNG_EQUATION_LAST)
1875 png_warning(png_ptr, "Unrecognized equation type for pCAL chunk");
1876
1877 purpose_len = png_check_keyword(png_ptr, purpose, &new_purpose) + 1;
1878 png_debug1(3, "pCAL purpose length = %d", (int)purpose_len);
1879 units_len = png_strlen(units) + (nparams == 0 ? 0 : 1);
1880 png_debug1(3, "pCAL units length = %d", (int)units_len);
1881 total_len = purpose_len + units_len + 10;
1882
1883 params_len = (png_size_tp)png_malloc(png_ptr,
1884 (png_alloc_size_t)(nparams * png_sizeof(png_size_t)));
1885
1886 /* Find the length of each parameter, making sure we don't count the
1887 * null terminator for the last parameter.
1888 */
1889 for (i = 0; i < nparams; i++)
1890 {
1891 params_len[i] = png_strlen(params[i]) + (i == nparams - 1 ? 0 : 1);
1892 png_debug2(3, "pCAL parameter %d length = %lu", i,
1893 (unsigned long)params_len[i]);
1894 total_len += params_len[i];
1895 }
1896
1897 png_debug1(3, "pCAL total length = %d", (int)total_len);
1898 png_write_chunk_header(png_ptr, png_pCAL, (png_uint_32)total_len);
1899 png_write_chunk_data(png_ptr, (png_const_bytep)new_purpose, purpose_len);
1900 png_save_int_32(buf, X0);
1901 png_save_int_32(buf + 4, X1);
1902 buf[8] = (png_byte)type;
1903 buf[9] = (png_byte)nparams;
1904 png_write_chunk_data(png_ptr, buf, (png_size_t)10);
1905 png_write_chunk_data(png_ptr, (png_const_bytep)units, (png_size_t)units_len);
1906
1907 png_free(png_ptr, new_purpose);
1908
1909 for (i = 0; i < nparams; i++)
1910 {
1911 png_write_chunk_data(png_ptr, (png_const_bytep)params[i], params_len[i]);
1912 }
1913
1914 png_free(png_ptr, params_len);
1915 png_write_chunk_end(png_ptr);
1916}
1917#endif
1918
1919#ifdef PNG_WRITE_sCAL_SUPPORTED
1920/* Write the sCAL chunk */
1921void /* PRIVATE */
1922png_write_sCAL_s(png_structp png_ptr, int unit, png_const_charp width,
1923 png_const_charp height)
1924{
1925 png_byte buf[64];
1926 png_size_t wlen, hlen, total_len;
1927
1928 png_debug(1, "in png_write_sCAL_s");
1929
1930 wlen = png_strlen(width);
1931 hlen = png_strlen(height);
1932 total_len = wlen + hlen + 2;
1933
1934 if (total_len > 64)
1935 {
1936 png_warning(png_ptr, "Can't write sCAL (buffer too small)");
1937 return;
1938 }
1939
1940 buf[0] = (png_byte)unit;
1941 png_memcpy(buf + 1, width, wlen + 1); /* Append the '\0' here */
1942 png_memcpy(buf + wlen + 2, height, hlen); /* Do NOT append the '\0' here */
1943
1944 png_debug1(3, "sCAL total length = %u", (unsigned int)total_len);
1945 png_write_complete_chunk(png_ptr, png_sCAL, buf, total_len);
1946}
1947#endif
1948
1949#ifdef PNG_WRITE_pHYs_SUPPORTED
1950/* Write the pHYs chunk */
1951void /* PRIVATE */
1952png_write_pHYs(png_structp png_ptr, png_uint_32 x_pixels_per_unit,
1953 png_uint_32 y_pixels_per_unit,
1954 int unit_type)
1955{
1956 png_byte buf[9];
1957
1958 png_debug(1, "in png_write_pHYs");
1959
1960 if (unit_type >= PNG_RESOLUTION_LAST)
1961 png_warning(png_ptr, "Unrecognized unit type for pHYs chunk");
1962
1963 png_save_uint_32(buf, x_pixels_per_unit);
1964 png_save_uint_32(buf + 4, y_pixels_per_unit);
1965 buf[8] = (png_byte)unit_type;
1966
1967 png_write_complete_chunk(png_ptr, png_pHYs, buf, (png_size_t)9);
1968}
1969#endif
1970
1971#ifdef PNG_WRITE_tIME_SUPPORTED
1972/* Write the tIME chunk. Use either png_convert_from_struct_tm()
1973 * or png_convert_from_time_t(), or fill in the structure yourself.
1974 */
1975void /* PRIVATE */
1976png_write_tIME(png_structp png_ptr, png_const_timep mod_time)
1977{
1978 png_byte buf[7];
1979
1980 png_debug(1, "in png_write_tIME");
1981
1982 if (mod_time->month > 12 || mod_time->month < 1 ||
1983 mod_time->day > 31 || mod_time->day < 1 ||
1984 mod_time->hour > 23 || mod_time->second > 60)
1985 {
1986 png_warning(png_ptr, "Invalid time specified for tIME chunk");
1987 return;
1988 }
1989
1990 png_save_uint_16(buf, mod_time->year);
1991 buf[2] = mod_time->month;
1992 buf[3] = mod_time->day;
1993 buf[4] = mod_time->hour;
1994 buf[5] = mod_time->minute;
1995 buf[6] = mod_time->second;
1996
1997 png_write_complete_chunk(png_ptr, png_tIME, buf, (png_size_t)7);
1998}
1999#endif
2000
2001/* Initializes the row writing capability of libpng */
2002void /* PRIVATE */
2003png_write_start_row(png_structp png_ptr)
2004{
2005#ifdef PNG_WRITE_INTERLACING_SUPPORTED
2006 /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
2007
2008 /* Start of interlace block */
2009 static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
2010
2011 /* Offset to next interlace block */
2012 static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
2013
2014 /* Start of interlace block in the y direction */
2015 static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
2016
2017 /* Offset to next interlace block in the y direction */
2018 static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
2019#endif
2020
2021 png_alloc_size_t buf_size;
2022 int usr_pixel_depth;
2023
2024 png_debug(1, "in png_write_start_row");
2025
2026 usr_pixel_depth = png_ptr->usr_channels * png_ptr->usr_bit_depth;
2027 buf_size = PNG_ROWBYTES(usr_pixel_depth, png_ptr->width) + 1;
2028
2029 /* 1.5.6: added to allow checking in the row write code. */
2030 png_ptr->transformed_pixel_depth = png_ptr->pixel_depth;
2031 png_ptr->maximum_pixel_depth = (png_byte)usr_pixel_depth;
2032
2033 /* Set up row buffer */
2034 png_ptr->row_buf = (png_bytep)png_malloc(png_ptr, buf_size);
2035
2036 png_ptr->row_buf[0] = PNG_FILTER_VALUE_NONE;
2037
2038#ifdef PNG_WRITE_FILTER_SUPPORTED
2039 /* Set up filtering buffer, if using this filter */
2040 if (png_ptr->do_filter & PNG_FILTER_SUB)
2041 {
2042 png_ptr->sub_row = (png_bytep)png_malloc(png_ptr, png_ptr->rowbytes + 1);
2043
2044 png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;
2045 }
2046
2047 /* We only need to keep the previous row if we are using one of these. */
2048 if (png_ptr->do_filter & (PNG_FILTER_AVG | PNG_FILTER_UP | PNG_FILTER_PAETH))
2049 {
2050 /* Set up previous row buffer */
2051 png_ptr->prev_row = (png_bytep)png_calloc(png_ptr, buf_size);
2052
2053 if (png_ptr->do_filter & PNG_FILTER_UP)
2054 {
2055 png_ptr->up_row = (png_bytep)png_malloc(png_ptr,
2056 png_ptr->rowbytes + 1);
2057
2058 png_ptr->up_row[0] = PNG_FILTER_VALUE_UP;
2059 }
2060
2061 if (png_ptr->do_filter & PNG_FILTER_AVG)
2062 {
2063 png_ptr->avg_row = (png_bytep)png_malloc(png_ptr,
2064 png_ptr->rowbytes + 1);
2065
2066 png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG;
2067 }
2068
2069 if (png_ptr->do_filter & PNG_FILTER_PAETH)
2070 {
2071 png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr,
2072 png_ptr->rowbytes + 1);
2073
2074 png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH;
2075 }
2076 }
2077#endif /* PNG_WRITE_FILTER_SUPPORTED */
2078
2079#ifdef PNG_WRITE_INTERLACING_SUPPORTED
2080 /* If interlaced, we need to set up width and height of pass */
2081 if (png_ptr->interlaced)
2082 {
2083 if (!(png_ptr->transformations & PNG_INTERLACE))
2084 {
2085 png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 -
2086 png_pass_ystart[0]) / png_pass_yinc[0];
2087
2088 png_ptr->usr_width = (png_ptr->width + png_pass_inc[0] - 1 -
2089 png_pass_start[0]) / png_pass_inc[0];
2090 }
2091
2092 else
2093 {
2094 png_ptr->num_rows = png_ptr->height;
2095 png_ptr->usr_width = png_ptr->width;
2096 }
2097 }
2098
2099 else
2100#endif
2101 {
2102 png_ptr->num_rows = png_ptr->height;
2103 png_ptr->usr_width = png_ptr->width;
2104 }
2105
2106 png_zlib_claim(png_ptr, PNG_ZLIB_FOR_IDAT);
2107 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
2108 png_ptr->zstream.next_out = png_ptr->zbuf;
2109}
2110
2111/* Internal use only. Called when finished processing a row of data. */
2112void /* PRIVATE */
2113png_write_finish_row(png_structp png_ptr)
2114{
2115#ifdef PNG_WRITE_INTERLACING_SUPPORTED
2116 /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
2117
2118 /* Start of interlace block */
2119 static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
2120
2121 /* Offset to next interlace block */
2122 static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
2123
2124 /* Start of interlace block in the y direction */
2125 static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
2126
2127 /* Offset to next interlace block in the y direction */
2128 static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
2129#endif
2130
2131 int ret;
2132
2133 png_debug(1, "in png_write_finish_row");
2134
2135 /* Next row */
2136 png_ptr->row_number++;
2137
2138 /* See if we are done */
2139 if (png_ptr->row_number < png_ptr->num_rows)
2140 return;
2141
2142#ifdef PNG_WRITE_INTERLACING_SUPPORTED
2143 /* If interlaced, go to next pass */
2144 if (png_ptr->interlaced)
2145 {
2146 png_ptr->row_number = 0;
2147 if (png_ptr->transformations & PNG_INTERLACE)
2148 {
2149 png_ptr->pass++;
2150 }
2151
2152 else
2153 {
2154 /* Loop until we find a non-zero width or height pass */
2155 do
2156 {
2157 png_ptr->pass++;
2158
2159 if (png_ptr->pass >= 7)
2160 break;
2161
2162 png_ptr->usr_width = (png_ptr->width +
2163 png_pass_inc[png_ptr->pass] - 1 -
2164 png_pass_start[png_ptr->pass]) /
2165 png_pass_inc[png_ptr->pass];
2166
2167 png_ptr->num_rows = (png_ptr->height +
2168 png_pass_yinc[png_ptr->pass] - 1 -
2169 png_pass_ystart[png_ptr->pass]) /
2170 png_pass_yinc[png_ptr->pass];
2171
2172 if (png_ptr->transformations & PNG_INTERLACE)
2173 break;
2174
2175 } while (png_ptr->usr_width == 0 || png_ptr->num_rows == 0);
2176
2177 }
2178
2179 /* Reset the row above the image for the next pass */
2180 if (png_ptr->pass < 7)
2181 {
2182 if (png_ptr->prev_row != NULL)
2183 png_memset(png_ptr->prev_row, 0,
2184 (png_size_t)(PNG_ROWBYTES(png_ptr->usr_channels*
2185 png_ptr->usr_bit_depth, png_ptr->width)) + 1);
2186
2187 return;
2188 }
2189 }
2190#endif
2191
2192 /* If we get here, we've just written the last row, so we need
2193 to flush the compressor */
2194 do
2195 {
2196 /* Tell the compressor we are done */
2197 ret = deflate(&png_ptr->zstream, Z_FINISH);
2198
2199 /* Check for an error */
2200 if (ret == Z_OK)
2201 {
2202 /* Check to see if we need more room */
2203 if (!(png_ptr->zstream.avail_out))
2204 {
2205 png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
2206 png_ptr->zstream.next_out = png_ptr->zbuf;
2207 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
2208 }
2209 }
2210
2211 else if (ret != Z_STREAM_END)
2212 {
2213 if (png_ptr->zstream.msg != NULL)
2214 png_error(png_ptr, png_ptr->zstream.msg);
2215
2216 else
2217 png_error(png_ptr, "zlib error");
2218 }
2219 } while (ret != Z_STREAM_END);
2220
2221 /* Write any extra space */
2222 if (png_ptr->zstream.avail_out < png_ptr->zbuf_size)
2223 {
2224 png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size -
2225 png_ptr->zstream.avail_out);
2226 }
2227
2228 png_zlib_release(png_ptr);
2229 png_ptr->zstream.data_type = Z_BINARY;
2230}
2231
2232#ifdef PNG_WRITE_INTERLACING_SUPPORTED
2233/* Pick out the correct pixels for the interlace pass.
2234 * The basic idea here is to go through the row with a source
2235 * pointer and a destination pointer (sp and dp), and copy the
2236 * correct pixels for the pass. As the row gets compacted,
2237 * sp will always be >= dp, so we should never overwrite anything.
2238 * See the default: case for the easiest code to understand.
2239 */
2240void /* PRIVATE */
2241png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass)
2242{
2243 /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
2244
2245 /* Start of interlace block */
2246 static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
2247
2248 /* Offset to next interlace block */
2249 static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
2250
2251 png_debug(1, "in png_do_write_interlace");
2252
2253 /* We don't have to do anything on the last pass (6) */
2254 if (pass < 6)
2255 {
2256 /* Each pixel depth is handled separately */
2257 switch (row_info->pixel_depth)
2258 {
2259 case 1:
2260 {
2261 png_bytep sp;
2262 png_bytep dp;
2263 int shift;
2264 int d;
2265 int value;
2266 png_uint_32 i;
2267 png_uint_32 row_width = row_info->width;
2268
2269 dp = row;
2270 d = 0;
2271 shift = 7;
2272
2273 for (i = png_pass_start[pass]; i < row_width;
2274 i += png_pass_inc[pass])
2275 {
2276 sp = row + (png_size_t)(i >> 3);
2277 value = (int)(*sp >> (7 - (int)(i & 0x07))) & 0x01;
2278 d |= (value << shift);
2279
2280 if (shift == 0)
2281 {
2282 shift = 7;
2283 *dp++ = (png_byte)d;
2284 d = 0;
2285 }
2286
2287 else
2288 shift--;
2289
2290 }
2291 if (shift != 7)
2292 *dp = (png_byte)d;
2293
2294 break;
2295 }
2296
2297 case 2:
2298 {
2299 png_bytep sp;
2300 png_bytep dp;
2301 int shift;
2302 int d;
2303 int value;
2304 png_uint_32 i;
2305 png_uint_32 row_width = row_info->width;
2306
2307 dp = row;
2308 shift = 6;
2309 d = 0;
2310
2311 for (i = png_pass_start[pass]; i < row_width;
2312 i += png_pass_inc[pass])
2313 {
2314 sp = row + (png_size_t)(i >> 2);
2315 value = (*sp >> ((3 - (int)(i & 0x03)) << 1)) & 0x03;
2316 d |= (value << shift);
2317
2318 if (shift == 0)
2319 {
2320 shift = 6;
2321 *dp++ = (png_byte)d;
2322 d = 0;
2323 }
2324
2325 else
2326 shift -= 2;
2327 }
2328 if (shift != 6)
2329 *dp = (png_byte)d;
2330
2331 break;
2332 }
2333
2334 case 4:
2335 {
2336 png_bytep sp;
2337 png_bytep dp;
2338 int shift;
2339 int d;
2340 int value;
2341 png_uint_32 i;
2342 png_uint_32 row_width = row_info->width;
2343
2344 dp = row;
2345 shift = 4;
2346 d = 0;
2347 for (i = png_pass_start[pass]; i < row_width;
2348 i += png_pass_inc[pass])
2349 {
2350 sp = row + (png_size_t)(i >> 1);
2351 value = (*sp >> ((1 - (int)(i & 0x01)) << 2)) & 0x0f;
2352 d |= (value << shift);
2353
2354 if (shift == 0)
2355 {
2356 shift = 4;
2357 *dp++ = (png_byte)d;
2358 d = 0;
2359 }
2360
2361 else
2362 shift -= 4;
2363 }
2364 if (shift != 4)
2365 *dp = (png_byte)d;
2366
2367 break;
2368 }
2369
2370 default:
2371 {
2372 png_bytep sp;
2373 png_bytep dp;
2374 png_uint_32 i;
2375 png_uint_32 row_width = row_info->width;
2376 png_size_t pixel_bytes;
2377
2378 /* Start at the beginning */
2379 dp = row;
2380
2381 /* Find out how many bytes each pixel takes up */
2382 pixel_bytes = (row_info->pixel_depth >> 3);
2383
2384 /* Loop through the row, only looking at the pixels that matter */
2385 for (i = png_pass_start[pass]; i < row_width;
2386 i += png_pass_inc[pass])
2387 {
2388 /* Find out where the original pixel is */
2389 sp = row + (png_size_t)i * pixel_bytes;
2390
2391 /* Move the pixel */
2392 if (dp != sp)
2393 png_memcpy(dp, sp, pixel_bytes);
2394
2395 /* Next pixel */
2396 dp += pixel_bytes;
2397 }
2398 break;
2399 }
2400 }
2401 /* Set new row width */
2402 row_info->width = (row_info->width +
2403 png_pass_inc[pass] - 1 -
2404 png_pass_start[pass]) /
2405 png_pass_inc[pass];
2406
2407 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
2408 row_info->width);
2409 }
2410}
2411#endif
2412
2413/* This filters the row, chooses which filter to use, if it has not already
2414 * been specified by the application, and then writes the row out with the
2415 * chosen filter.
2416 */
2417static void png_write_filtered_row(png_structp png_ptr, png_bytep filtered_row,
2418 png_size_t row_bytes);
2419
2420#define PNG_MAXSUM (((png_uint_32)(-1)) >> 1)
2421#define PNG_HISHIFT 10
2422#define PNG_LOMASK ((png_uint_32)0xffffL)
2423#define PNG_HIMASK ((png_uint_32)(~PNG_LOMASK >> PNG_HISHIFT))
2424void /* PRIVATE */
2425png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
2426{
2427 png_bytep best_row;
2428#ifdef PNG_WRITE_FILTER_SUPPORTED
2429 png_bytep prev_row, row_buf;
2430 png_uint_32 mins, bpp;
2431 png_byte filter_to_do = png_ptr->do_filter;
2432 png_size_t row_bytes = row_info->rowbytes;
2433#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
2434 int num_p_filters = png_ptr->num_prev_filters;
2435#endif
2436
2437 png_debug(1, "in png_write_find_filter");
2438
2439#ifndef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
2440 if (png_ptr->row_number == 0 && filter_to_do == PNG_ALL_FILTERS)
2441 {
2442 /* These will never be selected so we need not test them. */
2443 filter_to_do &= ~(PNG_FILTER_UP | PNG_FILTER_PAETH);
2444 }
2445#endif
2446
2447 /* Find out how many bytes offset each pixel is */
2448 bpp = (row_info->pixel_depth + 7) >> 3;
2449
2450 prev_row = png_ptr->prev_row;
2451#endif
2452 best_row = png_ptr->row_buf;
2453#ifdef PNG_WRITE_FILTER_SUPPORTED
2454 row_buf = best_row;
2455 mins = PNG_MAXSUM;
2456
2457 /* The prediction method we use is to find which method provides the
2458 * smallest value when summing the absolute values of the distances
2459 * from zero, using anything >= 128 as negative numbers. This is known
2460 * as the "minimum sum of absolute differences" heuristic. Other
2461 * heuristics are the "weighted minimum sum of absolute differences"
2462 * (experimental and can in theory improve compression), and the "zlib
2463 * predictive" method (not implemented yet), which does test compressions
2464 * of lines using different filter methods, and then chooses the
2465 * (series of) filter(s) that give minimum compressed data size (VERY
2466 * computationally expensive).
2467 *
2468 * GRR 980525: consider also
2469 *
2470 * (1) minimum sum of absolute differences from running average (i.e.,
2471 * keep running sum of non-absolute differences & count of bytes)
2472 * [track dispersion, too? restart average if dispersion too large?]
2473 *
2474 * (1b) minimum sum of absolute differences from sliding average, probably
2475 * with window size <= deflate window (usually 32K)
2476 *
2477 * (2) minimum sum of squared differences from zero or running average
2478 * (i.e., ~ root-mean-square approach)
2479 */
2480
2481
2482 /* We don't need to test the 'no filter' case if this is the only filter
2483 * that has been chosen, as it doesn't actually do anything to the data.
2484 */
2485 if ((filter_to_do & PNG_FILTER_NONE) && filter_to_do != PNG_FILTER_NONE)
2486 {
2487 png_bytep rp;
2488 png_uint_32 sum = 0;
2489 png_size_t i;
2490 int v;
2491
2492 for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++)
2493 {
2494 v = *rp;
2495 sum += (v < 128) ? v : 256 - v;
2496 }
2497
2498#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
2499 if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2500 {
2501 png_uint_32 sumhi, sumlo;
2502 int j;
2503 sumlo = sum & PNG_LOMASK;
2504 sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; /* Gives us some footroom */
2505
2506 /* Reduce the sum if we match any of the previous rows */
2507 for (j = 0; j < num_p_filters; j++)
2508 {
2509 if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE)
2510 {
2511 sumlo = (sumlo * png_ptr->filter_weights[j]) >>
2512 PNG_WEIGHT_SHIFT;
2513
2514 sumhi = (sumhi * png_ptr->filter_weights[j]) >>
2515 PNG_WEIGHT_SHIFT;
2516 }
2517 }
2518
2519 /* Factor in the cost of this filter (this is here for completeness,
2520 * but it makes no sense to have a "cost" for the NONE filter, as
2521 * it has the minimum possible computational cost - none).
2522 */
2523 sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >>
2524 PNG_COST_SHIFT;
2525
2526 sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >>
2527 PNG_COST_SHIFT;
2528
2529 if (sumhi > PNG_HIMASK)
2530 sum = PNG_MAXSUM;
2531
2532 else
2533 sum = (sumhi << PNG_HISHIFT) + sumlo;
2534 }
2535#endif
2536 mins = sum;
2537 }
2538
2539 /* Sub filter */
2540 if (filter_to_do == PNG_FILTER_SUB)
2541 /* It's the only filter so no testing is needed */
2542 {
2543 png_bytep rp, lp, dp;
2544 png_size_t i;
2545
2546 for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp;
2547 i++, rp++, dp++)
2548 {
2549 *dp = *rp;
2550 }
2551
2552 for (lp = row_buf + 1; i < row_bytes;
2553 i++, rp++, lp++, dp++)
2554 {
2555 *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);
2556 }
2557
2558 best_row = png_ptr->sub_row;
2559 }
2560
2561 else if (filter_to_do & PNG_FILTER_SUB)
2562 {
2563 png_bytep rp, dp, lp;
2564 png_uint_32 sum = 0, lmins = mins;
2565 png_size_t i;
2566 int v;
2567
2568#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
2569 /* We temporarily increase the "minimum sum" by the factor we
2570 * would reduce the sum of this filter, so that we can do the
2571 * early exit comparison without scaling the sum each time.
2572 */
2573 if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2574 {
2575 int j;
2576 png_uint_32 lmhi, lmlo;
2577 lmlo = lmins & PNG_LOMASK;
2578 lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
2579
2580 for (j = 0; j < num_p_filters; j++)
2581 {
2582 if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB)
2583 {
2584 lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
2585 PNG_WEIGHT_SHIFT;
2586
2587 lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
2588 PNG_WEIGHT_SHIFT;
2589 }
2590 }
2591
2592 lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
2593 PNG_COST_SHIFT;
2594
2595 lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
2596 PNG_COST_SHIFT;
2597
2598 if (lmhi > PNG_HIMASK)
2599 lmins = PNG_MAXSUM;
2600
2601 else
2602 lmins = (lmhi << PNG_HISHIFT) + lmlo;
2603 }
2604#endif
2605
2606 for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp;
2607 i++, rp++, dp++)
2608 {
2609 v = *dp = *rp;
2610
2611 sum += (v < 128) ? v : 256 - v;
2612 }
2613
2614 for (lp = row_buf + 1; i < row_bytes;
2615 i++, rp++, lp++, dp++)
2616 {
2617 v = *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);
2618
2619 sum += (v < 128) ? v : 256 - v;
2620
2621 if (sum > lmins) /* We are already worse, don't continue. */
2622 break;
2623 }
2624
2625#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
2626 if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2627 {
2628 int j;
2629 png_uint_32 sumhi, sumlo;
2630 sumlo = sum & PNG_LOMASK;
2631 sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
2632
2633 for (j = 0; j < num_p_filters; j++)
2634 {
2635 if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB)
2636 {
2637 sumlo = (sumlo * png_ptr->inv_filter_weights[j]) >>
2638 PNG_WEIGHT_SHIFT;
2639
2640 sumhi = (sumhi * png_ptr->inv_filter_weights[j]) >>
2641 PNG_WEIGHT_SHIFT;
2642 }
2643 }
2644
2645 sumlo = (sumlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
2646 PNG_COST_SHIFT;
2647
2648 sumhi = (sumhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
2649 PNG_COST_SHIFT;
2650
2651 if (sumhi > PNG_HIMASK)
2652 sum = PNG_MAXSUM;
2653
2654 else
2655 sum = (sumhi << PNG_HISHIFT) + sumlo;
2656 }
2657#endif
2658
2659 if (sum < mins)
2660 {
2661 mins = sum;
2662 best_row = png_ptr->sub_row;
2663 }
2664 }
2665
2666 /* Up filter */
2667 if (filter_to_do == PNG_FILTER_UP)
2668 {
2669 png_bytep rp, dp, pp;
2670 png_size_t i;
2671
2672 for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1,
2673 pp = prev_row + 1; i < row_bytes;
2674 i++, rp++, pp++, dp++)
2675 {
2676 *dp = (png_byte)(((int)*rp - (int)*pp) & 0xff);
2677 }
2678
2679 best_row = png_ptr->up_row;
2680 }
2681
2682 else if (filter_to_do & PNG_FILTER_UP)
2683 {
2684 png_bytep rp, dp, pp;
2685 png_uint_32 sum = 0, lmins = mins;
2686 png_size_t i;
2687 int v;
2688
2689
2690#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
2691 if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2692 {
2693 int j;
2694 png_uint_32 lmhi, lmlo;
2695 lmlo = lmins & PNG_LOMASK;
2696 lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
2697
2698 for (j = 0; j < num_p_filters; j++)
2699 {
2700 if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP)
2701 {
2702 lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
2703 PNG_WEIGHT_SHIFT;
2704
2705 lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
2706 PNG_WEIGHT_SHIFT;
2707 }
2708 }
2709
2710 lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >>
2711 PNG_COST_SHIFT;
2712
2713 lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >>
2714 PNG_COST_SHIFT;
2715
2716 if (lmhi > PNG_HIMASK)
2717 lmins = PNG_MAXSUM;
2718
2719 else
2720 lmins = (lmhi << PNG_HISHIFT) + lmlo;
2721 }
2722#endif
2723
2724 for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1,
2725 pp = prev_row + 1; i < row_bytes; i++)
2726 {
2727 v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
2728
2729 sum += (v < 128) ? v : 256 - v;
2730
2731 if (sum > lmins) /* We are already worse, don't continue. */
2732 break;
2733 }
2734
2735#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
2736 if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2737 {
2738 int j;
2739 png_uint_32 sumhi, sumlo;
2740 sumlo = sum & PNG_LOMASK;
2741 sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
2742
2743 for (j = 0; j < num_p_filters; j++)
2744 {
2745 if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP)
2746 {
2747 sumlo = (sumlo * png_ptr->filter_weights[j]) >>
2748 PNG_WEIGHT_SHIFT;
2749
2750 sumhi = (sumhi * png_ptr->filter_weights[j]) >>
2751 PNG_WEIGHT_SHIFT;
2752 }
2753 }
2754
2755 sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >>
2756 PNG_COST_SHIFT;
2757
2758 sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >>
2759 PNG_COST_SHIFT;
2760
2761 if (sumhi > PNG_HIMASK)
2762 sum = PNG_MAXSUM;
2763
2764 else
2765 sum = (sumhi << PNG_HISHIFT) + sumlo;
2766 }
2767#endif
2768
2769 if (sum < mins)
2770 {
2771 mins = sum;
2772 best_row = png_ptr->up_row;
2773 }
2774 }
2775
2776 /* Avg filter */
2777 if (filter_to_do == PNG_FILTER_AVG)
2778 {
2779 png_bytep rp, dp, pp, lp;
2780 png_uint_32 i;
2781
2782 for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1,
2783 pp = prev_row + 1; i < bpp; i++)
2784 {
2785 *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);
2786 }
2787
2788 for (lp = row_buf + 1; i < row_bytes; i++)
2789 {
2790 *dp++ = (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2))
2791 & 0xff);
2792 }
2793 best_row = png_ptr->avg_row;
2794 }
2795
2796 else if (filter_to_do & PNG_FILTER_AVG)
2797 {
2798 png_bytep rp, dp, pp, lp;
2799 png_uint_32 sum = 0, lmins = mins;
2800 png_size_t i;
2801 int v;
2802
2803#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
2804 if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2805 {
2806 int j;
2807 png_uint_32 lmhi, lmlo;
2808 lmlo = lmins & PNG_LOMASK;
2809 lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
2810
2811 for (j = 0; j < num_p_filters; j++)
2812 {
2813 if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_AVG)
2814 {
2815 lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
2816 PNG_WEIGHT_SHIFT;
2817
2818 lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
2819 PNG_WEIGHT_SHIFT;
2820 }
2821 }
2822
2823 lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >>
2824 PNG_COST_SHIFT;
2825
2826 lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >>
2827 PNG_COST_SHIFT;
2828
2829 if (lmhi > PNG_HIMASK)
2830 lmins = PNG_MAXSUM;
2831
2832 else
2833 lmins = (lmhi << PNG_HISHIFT) + lmlo;
2834 }
2835#endif
2836
2837 for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1,
2838 pp = prev_row + 1; i < bpp; i++)
2839 {
2840 v = *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);
2841
2842 sum += (v < 128) ? v : 256 - v;
2843 }
2844
2845 for (lp = row_buf + 1; i < row_bytes; i++)
2846 {
2847 v = *dp++ =
2848 (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2)) & 0xff);
2849
2850 sum += (v < 128) ? v : 256 - v;
2851
2852 if (sum > lmins) /* We are already worse, don't continue. */
2853 break;
2854 }
2855
2856#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
2857 if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2858 {
2859 int j;
2860 png_uint_32 sumhi, sumlo;
2861 sumlo = sum & PNG_LOMASK;
2862 sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
2863
2864 for (j = 0; j < num_p_filters; j++)
2865 {
2866 if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE)
2867 {
2868 sumlo = (sumlo * png_ptr->filter_weights[j]) >>
2869 PNG_WEIGHT_SHIFT;
2870
2871 sumhi = (sumhi * png_ptr->filter_weights[j]) >>
2872 PNG_WEIGHT_SHIFT;
2873 }
2874 }
2875
2876 sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >>
2877 PNG_COST_SHIFT;
2878
2879 sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >>
2880 PNG_COST_SHIFT;
2881
2882 if (sumhi > PNG_HIMASK)
2883 sum = PNG_MAXSUM;
2884
2885 else
2886 sum = (sumhi << PNG_HISHIFT) + sumlo;
2887 }
2888#endif
2889
2890 if (sum < mins)
2891 {
2892 mins = sum;
2893 best_row = png_ptr->avg_row;
2894 }
2895 }
2896
2897 /* Paeth filter */
2898 if (filter_to_do == PNG_FILTER_PAETH)
2899 {
2900 png_bytep rp, dp, pp, cp, lp;
2901 png_size_t i;
2902
2903 for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1,
2904 pp = prev_row + 1; i < bpp; i++)
2905 {
2906 *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
2907 }
2908
2909 for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++)
2910 {
2911 int a, b, c, pa, pb, pc, p;
2912
2913 b = *pp++;
2914 c = *cp++;
2915 a = *lp++;
2916
2917 p = b - c;
2918 pc = a - c;
2919
2920#ifdef PNG_USE_ABS
2921 pa = abs(p);
2922 pb = abs(pc);
2923 pc = abs(p + pc);
2924#else
2925 pa = p < 0 ? -p : p;
2926 pb = pc < 0 ? -pc : pc;
2927 pc = (p + pc) < 0 ? -(p + pc) : p + pc;
2928#endif
2929
2930 p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
2931
2932 *dp++ = (png_byte)(((int)*rp++ - p) & 0xff);
2933 }
2934 best_row = png_ptr->paeth_row;
2935 }
2936
2937 else if (filter_to_do & PNG_FILTER_PAETH)
2938 {
2939 png_bytep rp, dp, pp, cp, lp;
2940 png_uint_32 sum = 0, lmins = mins;
2941 png_size_t i;
2942 int v;
2943
2944#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
2945 if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2946 {
2947 int j;
2948 png_uint_32 lmhi, lmlo;
2949 lmlo = lmins & PNG_LOMASK;
2950 lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
2951
2952 for (j = 0; j < num_p_filters; j++)
2953 {
2954 if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH)
2955 {
2956 lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
2957 PNG_WEIGHT_SHIFT;
2958
2959 lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
2960 PNG_WEIGHT_SHIFT;
2961 }
2962 }
2963
2964 lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >>
2965 PNG_COST_SHIFT;
2966
2967 lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >>
2968 PNG_COST_SHIFT;
2969
2970 if (lmhi > PNG_HIMASK)
2971 lmins = PNG_MAXSUM;
2972
2973 else
2974 lmins = (lmhi << PNG_HISHIFT) + lmlo;
2975 }
2976#endif
2977
2978 for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1,
2979 pp = prev_row + 1; i < bpp; i++)
2980 {
2981 v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
2982
2983 sum += (v < 128) ? v : 256 - v;
2984 }
2985
2986 for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++)
2987 {
2988 int a, b, c, pa, pb, pc, p;
2989
2990 b = *pp++;
2991 c = *cp++;
2992 a = *lp++;
2993
2994#ifndef PNG_SLOW_PAETH
2995 p = b - c;
2996 pc = a - c;
2997#ifdef PNG_USE_ABS
2998 pa = abs(p);
2999 pb = abs(pc);
3000 pc = abs(p + pc);
3001#else
3002 pa = p < 0 ? -p : p;
3003 pb = pc < 0 ? -pc : pc;
3004 pc = (p + pc) < 0 ? -(p + pc) : p + pc;
3005#endif
3006 p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
3007#else /* PNG_SLOW_PAETH */
3008 p = a + b - c;
3009 pa = abs(p - a);
3010 pb = abs(p - b);
3011 pc = abs(p - c);
3012
3013 if (pa <= pb && pa <= pc)
3014 p = a;
3015
3016 else if (pb <= pc)
3017 p = b;
3018
3019 else
3020 p = c;
3021#endif /* PNG_SLOW_PAETH */
3022
3023 v = *dp++ = (png_byte)(((int)*rp++ - p) & 0xff);
3024
3025 sum += (v < 128) ? v : 256 - v;
3026
3027 if (sum > lmins) /* We are already worse, don't continue. */
3028 break;
3029 }
3030
3031#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
3032 if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
3033 {
3034 int j;
3035 png_uint_32 sumhi, sumlo;
3036 sumlo = sum & PNG_LOMASK;
3037 sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
3038
3039 for (j = 0; j < num_p_filters; j++)
3040 {
3041 if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH)
3042 {
3043 sumlo = (sumlo * png_ptr->filter_weights[j]) >>
3044 PNG_WEIGHT_SHIFT;
3045
3046 sumhi = (sumhi * png_ptr->filter_weights[j]) >>
3047 PNG_WEIGHT_SHIFT;
3048 }
3049 }
3050
3051 sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >>
3052 PNG_COST_SHIFT;
3053
3054 sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >>
3055 PNG_COST_SHIFT;
3056
3057 if (sumhi > PNG_HIMASK)
3058 sum = PNG_MAXSUM;
3059
3060 else
3061 sum = (sumhi << PNG_HISHIFT) + sumlo;
3062 }
3063#endif
3064
3065 if (sum < mins)
3066 {
3067 best_row = png_ptr->paeth_row;
3068 }
3069 }
3070#endif /* PNG_WRITE_FILTER_SUPPORTED */
3071
3072 /* Do the actual writing of the filtered row data from the chosen filter. */
3073 png_write_filtered_row(png_ptr, best_row, row_info->rowbytes+1);
3074
3075#ifdef PNG_WRITE_FILTER_SUPPORTED
3076#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
3077 /* Save the type of filter we picked this time for future calculations */
3078 if (png_ptr->num_prev_filters > 0)
3079 {
3080 int j;
3081
3082 for (j = 1; j < num_p_filters; j++)
3083 {
3084 png_ptr->prev_filters[j] = png_ptr->prev_filters[j - 1];
3085 }
3086
3087 png_ptr->prev_filters[j] = best_row[0];
3088 }
3089#endif
3090#endif /* PNG_WRITE_FILTER_SUPPORTED */
3091}
3092
3093
3094/* Do the actual writing of a previously filtered row. */
3095static void
3096png_write_filtered_row(png_structp png_ptr, png_bytep filtered_row,
3097 png_size_t avail/*includes filter byte*/)
3098{
3099 png_debug(1, "in png_write_filtered_row");
3100
3101 png_debug1(2, "filter = %d", filtered_row[0]);
3102 /* Set up the zlib input buffer */
3103
3104 png_ptr->zstream.next_in = filtered_row;
3105 png_ptr->zstream.avail_in = 0;
3106 /* Repeat until we have compressed all the data */
3107 do
3108 {
3109 int ret; /* Return of zlib */
3110
3111 /* Record the number of bytes available - zlib supports at least 65535
3112 * bytes at one step, depending on the size of the zlib type 'uInt', the
3113 * maximum size zlib can write at once is ZLIB_IO_MAX (from pngpriv.h).
3114 * Use this because on 16 bit systems 'rowbytes' can be up to 65536 (i.e.
3115 * one more than 16 bits) and, in this case 'rowbytes+1' can overflow a
3116 * uInt. ZLIB_IO_MAX can be safely reduced to cause zlib to be called
3117 * with smaller chunks of data.
3118 */
3119 if (png_ptr->zstream.avail_in == 0)
3120 {
3121 if (avail > ZLIB_IO_MAX)
3122 {
3123 png_ptr->zstream.avail_in = ZLIB_IO_MAX;
3124 avail -= ZLIB_IO_MAX;
3125 }
3126
3127 else
3128 {
3129 /* So this will fit in the available uInt space: */
3130 png_ptr->zstream.avail_in = (uInt)avail;
3131 avail = 0;
3132 }
3133 }
3134
3135 /* Compress the data */
3136 ret = deflate(&png_ptr->zstream, Z_NO_FLUSH);
3137
3138 /* Check for compression errors */
3139 if (ret != Z_OK)
3140 {
3141 if (png_ptr->zstream.msg != NULL)
3142 png_error(png_ptr, png_ptr->zstream.msg);
3143
3144 else
3145 png_error(png_ptr, "zlib error");
3146 }
3147
3148 /* See if it is time to write another IDAT */
3149 if (!(png_ptr->zstream.avail_out))
3150 {
3151 /* Write the IDAT and reset the zlib output buffer */
3152 png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
3153 }
3154 /* Repeat until all data has been compressed */
3155 } while (avail > 0 || png_ptr->zstream.avail_in > 0);
3156
3157 /* Swap the current and previous rows */
3158 if (png_ptr->prev_row != NULL)
3159 {
3160 png_bytep tptr;
3161
3162 tptr = png_ptr->prev_row;
3163 png_ptr->prev_row = png_ptr->row_buf;
3164 png_ptr->row_buf = tptr;
3165 }
3166
3167 /* Finish row - updates counters and flushes zlib if last row */
3168 png_write_finish_row(png_ptr);
3169
3170#ifdef PNG_WRITE_FLUSH_SUPPORTED
3171 png_ptr->flush_rows++;
3172
3173 if (png_ptr->flush_dist > 0 &&
3174 png_ptr->flush_rows >= png_ptr->flush_dist)
3175 {
3176 png_write_flush(png_ptr);
3177 }
3178#endif
3179}
3180#endif /* PNG_WRITE_SUPPORTED */
generated by cgit v1.1 at 2024-07-11 22:53:03 +0000