aboutsummaryrefslogtreecommitdiffstatshomepage
path: root/libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/readpng.c
diff options
context:
space:
mode:
Diffstat (limited to 'libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/readpng.c')
-rw-r--r--libraries/irrlicht-1.8/source/Irrlicht/libpng/contrib/gregbook/readpng.c311
1 files changed, 311 insertions, 0 deletions
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 @@
1/*---------------------------------------------------------------------------
2
3 rpng - simple PNG display program readpng.c
4
5 ---------------------------------------------------------------------------
6
7 Copyright (c) 1998-2007 Greg Roelofs. All rights reserved.
8
9 This software is provided "as is," without warranty of any kind,
10 express or implied. In no event shall the author or contributors
11 be held liable for any damages arising in any way from the use of
12 this software.
13
14 The contents of this file are DUAL-LICENSED. You may modify and/or
15 redistribute this software according to the terms of one of the
16 following two licenses (at your option):
17
18
19 LICENSE 1 ("BSD-like with advertising clause"):
20
21 Permission is granted to anyone to use this software for any purpose,
22 including commercial applications, and to alter it and redistribute
23 it freely, subject to the following restrictions:
24
25 1. Redistributions of source code must retain the above copyright
26 notice, disclaimer, and this list of conditions.
27 2. Redistributions in binary form must reproduce the above copyright
28 notice, disclaimer, and this list of conditions in the documenta-
29 tion and/or other materials provided with the distribution.
30 3. All advertising materials mentioning features or use of this
31 software must display the following acknowledgment:
32
33 This product includes software developed by Greg Roelofs
34 and contributors for the book, "PNG: The Definitive Guide,"
35 published by O'Reilly and Associates.
36
37
38 LICENSE 2 (GNU GPL v2 or later):
39
40 This program is free software; you can redistribute it and/or modify
41 it under the terms of the GNU General Public License as published by
42 the Free Software Foundation; either version 2 of the License, or
43 (at your option) any later version.
44
45 This program is distributed in the hope that it will be useful,
46 but WITHOUT ANY WARRANTY; without even the implied warranty of
47 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
48 GNU General Public License for more details.
49
50 You should have received a copy of the GNU General Public License
51 along with this program; if not, write to the Free Software Foundation,
52 Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
53
54 ---------------------------------------------------------------------------*/
55
56#include <stdio.h>
57#include <stdlib.h>
58
59#include "png.h" /* libpng header; includes zlib.h */
60#include "readpng.h" /* typedefs, common macros, public prototypes */
61
62/* future versions of libpng will provide this macro: */
63#ifndef png_jmpbuf
64# define png_jmpbuf(png_ptr) ((png_ptr)->jmpbuf)
65#endif
66
67
68static png_structp png_ptr = NULL;
69static png_infop info_ptr = NULL;
70
71png_uint_32 width, height;
72int bit_depth, color_type;
73uch *image_data = NULL;
74
75
76void readpng_version_info(void)
77{
78 fprintf(stderr, " Compiled with libpng %s; using libpng %s.\n",
79 PNG_LIBPNG_VER_STRING, png_libpng_ver);
80 fprintf(stderr, " Compiled with zlib %s; using zlib %s.\n",
81 ZLIB_VERSION, zlib_version);
82}
83
84
85/* return value = 0 for success, 1 for bad sig, 2 for bad IHDR, 4 for no mem */
86
87int readpng_init(FILE *infile, ulg *pWidth, ulg *pHeight)
88{
89 uch sig[8];
90
91
92 /* first do a quick check that the file really is a PNG image; could
93 * have used slightly more general png_sig_cmp() function instead */
94
95 fread(sig, 1, 8, infile);
96 if (png_sig_cmp(sig, 0, 8))
97 return 1; /* bad signature */
98
99
100 /* could pass pointers to user-defined error handlers instead of NULLs: */
101
102 png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
103 if (!png_ptr)
104 return 4; /* out of memory */
105
106 info_ptr = png_create_info_struct(png_ptr);
107 if (!info_ptr) {
108 png_destroy_read_struct(&png_ptr, NULL, NULL);
109 return 4; /* out of memory */
110 }
111
112
113 /* we could create a second info struct here (end_info), but it's only
114 * useful if we want to keep pre- and post-IDAT chunk info separated
115 * (mainly for PNG-aware image editors and converters) */
116
117
118 /* setjmp() must be called in every function that calls a PNG-reading
119 * libpng function */
120
121 if (setjmp(png_jmpbuf(png_ptr))) {
122 png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
123 return 2;
124 }
125
126
127 png_init_io(png_ptr, infile);
128 png_set_sig_bytes(png_ptr, 8); /* we already read the 8 signature bytes */
129
130 png_read_info(png_ptr, info_ptr); /* read all PNG info up to image data */
131
132
133 /* alternatively, could make separate calls to png_get_image_width(),
134 * etc., but want bit_depth and color_type for later [don't care about
135 * compression_type and filter_type => NULLs] */
136
137 png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type,
138 NULL, NULL, NULL);
139 *pWidth = width;
140 *pHeight = height;
141
142
143 /* OK, that's all we need for now; return happy */
144
145 return 0;
146}
147
148
149
150
151/* returns 0 if succeeds, 1 if fails due to no bKGD chunk, 2 if libpng error;
152 * scales values to 8-bit if necessary */
153
154int readpng_get_bgcolor(uch *red, uch *green, uch *blue)
155{
156 png_color_16p pBackground;
157
158
159 /* setjmp() must be called in every function that calls a PNG-reading
160 * libpng function */
161
162 if (setjmp(png_jmpbuf(png_ptr))) {
163 png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
164 return 2;
165 }
166
167
168 if (!png_get_valid(png_ptr, info_ptr, PNG_INFO_bKGD))
169 return 1;
170
171 /* it is not obvious from the libpng documentation, but this function
172 * takes a pointer to a pointer, and it always returns valid red, green
173 * and blue values, regardless of color_type: */
174
175 png_get_bKGD(png_ptr, info_ptr, &pBackground);
176
177
178 /* however, it always returns the raw bKGD data, regardless of any
179 * bit-depth transformations, so check depth and adjust if necessary */
180
181 if (bit_depth == 16) {
182 *red = pBackground->red >> 8;
183 *green = pBackground->green >> 8;
184 *blue = pBackground->blue >> 8;
185 } else if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8) {
186 if (bit_depth == 1)
187 *red = *green = *blue = pBackground->gray? 255 : 0;
188 else if (bit_depth == 2)
189 *red = *green = *blue = (255/3) * pBackground->gray;
190 else /* bit_depth == 4 */
191 *red = *green = *blue = (255/15) * pBackground->gray;
192 } else {
193 *red = (uch)pBackground->red;
194 *green = (uch)pBackground->green;
195 *blue = (uch)pBackground->blue;
196 }
197
198 return 0;
199}
200
201
202
203
204/* display_exponent == LUT_exponent * CRT_exponent */
205
206uch *readpng_get_image(double display_exponent, int *pChannels, ulg *pRowbytes)
207{
208 double gamma;
209 png_uint_32 i, rowbytes;
210 png_bytepp row_pointers = NULL;
211
212
213 /* setjmp() must be called in every function that calls a PNG-reading
214 * libpng function */
215
216 if (setjmp(png_jmpbuf(png_ptr))) {
217 png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
218 return NULL;
219 }
220
221
222 /* expand palette images to RGB, low-bit-depth grayscale images to 8 bits,
223 * transparency chunks to full alpha channel; strip 16-bit-per-sample
224 * images to 8 bits per sample; and convert grayscale to RGB[A] */
225
226 if (color_type == PNG_COLOR_TYPE_PALETTE)
227 png_set_expand(png_ptr);
228 if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8)
229 png_set_expand(png_ptr);
230 if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))
231 png_set_expand(png_ptr);
232#ifdef PNG_READ_16_TO_8_SUPPORTED
233 if (bit_depth == 16)
234# ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
235 png_set_scale_16(png_ptr);
236# else
237 png_set_strip_16(png_ptr);
238# endif
239#endif
240 if (color_type == PNG_COLOR_TYPE_GRAY ||
241 color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
242 png_set_gray_to_rgb(png_ptr);
243
244
245 /* unlike the example in the libpng documentation, we have *no* idea where
246 * this file may have come from--so if it doesn't have a file gamma, don't
247 * do any correction ("do no harm") */
248
249 if (png_get_gAMA(png_ptr, info_ptr, &gamma))
250 png_set_gamma(png_ptr, display_exponent, gamma);
251
252
253 /* all transformations have been registered; now update info_ptr data,
254 * get rowbytes and channels, and allocate image memory */
255
256 png_read_update_info(png_ptr, info_ptr);
257
258 *pRowbytes = rowbytes = png_get_rowbytes(png_ptr, info_ptr);
259 *pChannels = (int)png_get_channels(png_ptr, info_ptr);
260
261 if ((image_data = (uch *)malloc(rowbytes*height)) == NULL) {
262 png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
263 return NULL;
264 }
265 if ((row_pointers = (png_bytepp)malloc(height*sizeof(png_bytep))) == NULL) {
266 png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
267 free(image_data);
268 image_data = NULL;
269 return NULL;
270 }
271
272 Trace((stderr, "readpng_get_image: channels = %d, rowbytes = %ld, height = %ld\n",
273 *pChannels, rowbytes, height));
274
275
276 /* set the individual row_pointers to point at the correct offsets */
277
278 for (i = 0; i < height; ++i)
279 row_pointers[i] = image_data + i*rowbytes;
280
281
282 /* now we can go ahead and just read the whole image */
283
284 png_read_image(png_ptr, row_pointers);
285
286
287 /* and we're done! (png_read_end() can be omitted if no processing of
288 * post-IDAT text/time/etc. is desired) */
289
290 free(row_pointers);
291 row_pointers = NULL;
292
293 png_read_end(png_ptr, NULL);
294
295 return image_data;
296}
297
298
299void readpng_cleanup(int free_image_data)
300{
301 if (free_image_data && image_data) {
302 free(image_data);
303 image_data = NULL;
304 }
305
306 if (png_ptr && info_ptr) {
307 png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
308 png_ptr = NULL;
309 info_ptr = NULL;
310 }
311}
generated by cgit v1.1 at 2024-07-12 03:58:15 +0000