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2 /* png.h - header file for PNG reference library | |
3 * | |
4 * libpng version 1.6.20, December 3, 2015 | |
5 * | |
6 * Copyright (c) 1998-2015 Glenn Randers-Pehrson | |
7 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) | |
8 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) | |
9 * | |
10 * This code is released under the libpng license (See LICENSE, below) | |
11 * | |
12 * Authors and maintainers: | |
13 * libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat | |
14 * libpng versions 0.89, June 1996, through 0.96, May 1997: Andreas Dilger | |
15 * libpng versions 0.97, January 1998, through 1.6.20, December 3, 2015: | |
16 * Glenn Randers-Pehrson. | |
17 * See also "Contributing Authors", below. | |
18 */ | |
19 | |
20 /* | |
21 * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE: | |
22 * | |
23 * If you modify libpng you may insert additional notices immediately following | |
24 * this sentence. | |
25 * | |
26 * This code is released under the libpng license. | |
27 * | |
28 * libpng versions 1.0.7, July 1, 2000, through 1.6.20, December 3, 2015, are | |
29 * Copyright (c) 2000-2002, 2004, 2006-2015 Glenn Randers-Pehrson, are | |
30 * derived from libpng-1.0.6, and are distributed according to the same | |
31 * disclaimer and license as libpng-1.0.6 with the following individuals | |
32 * added to the list of Contributing Authors: | |
33 * | |
34 * Simon-Pierre Cadieux | |
35 * Eric S. Raymond | |
36 * Mans Rullgard | |
37 * Cosmin Truta | |
38 * Gilles Vollant | |
39 * James Yu | |
40 * | |
41 * and with the following additions to the disclaimer: | |
42 * | |
43 * There is no warranty against interference with your enjoyment of the | |
44 * library or against infringement. There is no warranty that our | |
45 * efforts or the library will fulfill any of your particular purposes | |
46 * or needs. This library is provided with all faults, and the entire | |
47 * risk of satisfactory quality, performance, accuracy, and effort is with | |
48 * the user. | |
49 * | |
50 * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are | |
51 * Copyright (c) 1998-2000 Glenn Randers-Pehrson, are derived from | |
52 * libpng-0.96, and are distributed according to the same disclaimer and | |
53 * license as libpng-0.96, with the following individuals added to the list | |
54 * of Contributing Authors: | |
55 * | |
56 * Tom Lane | |
57 * Glenn Randers-Pehrson | |
58 * Willem van Schaik | |
59 * | |
60 * libpng versions 0.89, June 1996, through 0.96, May 1997, are | |
61 * Copyright (c) 1996-1997 Andreas Dilger, are derived from libpng-0.88, | |
62 * and are distributed according to the same disclaimer and license as | |
63 * libpng-0.88, with the following individuals added to the list of | |
64 * Contributing Authors: | |
65 * | |
66 * John Bowler | |
67 * Kevin Bracey | |
68 * Sam Bushell | |
69 * Magnus Holmgren | |
70 * Greg Roelofs | |
71 * Tom Tanner | |
72 * | |
73 * libpng versions 0.5, May 1995, through 0.88, January 1996, are | |
74 * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. | |
75 * | |
76 * For the purposes of this copyright and license, "Contributing Authors" | |
77 * is defined as the following set of individuals: | |
78 * | |
79 * Andreas Dilger | |
80 * Dave Martindale | |
81 * Guy Eric Schalnat | |
82 * Paul Schmidt | |
83 * Tim Wegner | |
84 * | |
85 * The PNG Reference Library is supplied "AS IS". The Contributing Authors | |
86 * and Group 42, Inc. disclaim all warranties, expressed or implied, | |
87 * including, without limitation, the warranties of merchantability and of | |
88 * fitness for any purpose. The Contributing Authors and Group 42, Inc. | |
89 * assume no liability for direct, indirect, incidental, special, exemplary, | |
90 * or consequential damages, which may result from the use of the PNG | |
91 * Reference Library, even if advised of the possibility of such damage. | |
92 * | |
93 * Permission is hereby granted to use, copy, modify, and distribute this | |
94 * source code, or portions hereof, for any purpose, without fee, subject | |
95 * to the following restrictions: | |
96 * | |
97 * 1. The origin of this source code must not be misrepresented. | |
98 * | |
99 * 2. Altered versions must be plainly marked as such and must not | |
100 * be misrepresented as being the original source. | |
101 * | |
102 * 3. This Copyright notice may not be removed or altered from any | |
103 * source or altered source distribution. | |
104 * | |
105 * The Contributing Authors and Group 42, Inc. specifically permit, without | |
106 * fee, and encourage the use of this source code as a component to | |
107 * supporting the PNG file format in commercial products. If you use this | |
108 * source code in a product, acknowledgment is not required but would be | |
109 * appreciated. | |
110 * | |
111 * END OF COPYRIGHT NOTICE, DISCLAIMER, and LICENSE. | |
112 */ | |
113 | |
114 /* | |
115 * A "png_get_copyright" function is available, for convenient use in "about" | |
116 * boxes and the like: | |
117 * | |
118 * printf("%s", png_get_copyright(NULL)); | |
119 * | |
120 * Also, the PNG logo (in PNG format, of course) is supplied in the | |
121 * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31). | |
122 */ | |
123 | |
124 /* | |
125 * Libpng is OSI Certified Open Source Software. OSI Certified Open Source is | |
126 * a certification mark of the Open Source Initiative. OSI has not addressed | |
127 * the additional disclaimers inserted at version 1.0.7. | |
128 */ | |
129 | |
130 /* | |
131 * The contributing authors would like to thank all those who helped | |
132 * with testing, bug fixes, and patience. This wouldn't have been | |
133 * possible without all of you. | |
134 * | |
135 * Thanks to Frank J. T. Wojcik for helping with the documentation. | |
136 */ | |
137 | |
138 /* Note about libpng version numbers: | |
139 * | |
140 * Due to various miscommunications, unforeseen code incompatibilities | |
141 * and occasional factors outside the authors' control, version numbering | |
142 * on the library has not always been consistent and straightforward. | |
143 * The following table summarizes matters since version 0.89c, which was | |
144 * the first widely used release: | |
145 * | |
146 * source png.h png.h shared-lib | |
147 * version string int version | |
148 * ------- ------ ----- ---------- | |
149 * 0.89c "1.0 beta 3" 0.89 89 1.0.89 | |
150 * 0.90 "1.0 beta 4" 0.90 90 0.90 [should have been 2.0.90] | |
151 * 0.95 "1.0 beta 5" 0.95 95 0.95 [should have been 2.0.95] | |
152 * 0.96 "1.0 beta 6" 0.96 96 0.96 [should have been 2.0.96] | |
153 * 0.97b "1.00.97 beta 7" 1.00.97 97 1.0.1 [should have been 2.0.97] | |
154 * 0.97c 0.97 97 2.0.97 | |
155 * 0.98 0.98 98 2.0.98 | |
156 * 0.99 0.99 98 2.0.99 | |
157 * 0.99a-m 0.99 99 2.0.99 | |
158 * 1.00 1.00 100 2.1.0 [100 should be 10000] | |
159 * 1.0.0 (from here on, the 100 2.1.0 [100 should be 10000] | |
160 * 1.0.1 png.h string is 10001 2.1.0 | |
161 * 1.0.1a-e identical to the 10002 from here on, the shared library | |
162 * 1.0.2 source version) 10002 is 2.V where V is the source code | |
163 * 1.0.2a-b 10003 version, except as noted. | |
164 * 1.0.3 10003 | |
165 * 1.0.3a-d 10004 | |
166 * 1.0.4 10004 | |
167 * 1.0.4a-f 10005 | |
168 * 1.0.5 (+ 2 patches) 10005 | |
169 * 1.0.5a-d 10006 | |
170 * 1.0.5e-r 10100 (not source compatible) | |
171 * 1.0.5s-v 10006 (not binary compatible) | |
172 * 1.0.6 (+ 3 patches) 10006 (still binary incompatible) | |
173 * 1.0.6d-f 10007 (still binary incompatible) | |
174 * 1.0.6g 10007 | |
175 * 1.0.6h 10007 10.6h (testing xy.z so-numbering) | |
176 * 1.0.6i 10007 10.6i | |
177 * 1.0.6j 10007 2.1.0.6j (incompatible with 1.0.0) | |
178 * 1.0.7beta11-14 DLLNUM 10007 2.1.0.7beta11-14 (binary compatible) | |
179 * 1.0.7beta15-18 1 10007 2.1.0.7beta15-18 (binary compatible) | |
180 * 1.0.7rc1-2 1 10007 2.1.0.7rc1-2 (binary compatible) | |
181 * 1.0.7 1 10007 (still compatible) | |
182 * ... | |
183 * 1.0.19 10 10019 10.so.0.19[.0] | |
184 * ... | |
185 * 1.2.53 13 10253 12.so.0.53[.0] | |
186 * ... | |
187 * 1.5.23 15 10523 15.so.15.23[.0] | |
188 * ... | |
189 * 1.6.20 16 10620 16.so.16.20[.0] | |
190 * | |
191 * Henceforth the source version will match the shared-library major | |
192 * and minor numbers; the shared-library major version number will be | |
193 * used for changes in backward compatibility, as it is intended. The | |
194 * PNG_LIBPNG_VER macro, which is not used within libpng but is available | |
195 * for applications, is an unsigned integer of the form xyyzz corresponding | |
196 * to the source version x.y.z (leading zeros in y and z). Beta versions | |
197 * were given the previous public release number plus a letter, until | |
198 * version 1.0.6j; from then on they were given the upcoming public | |
199 * release number plus "betaNN" or "rcNN". | |
200 * | |
201 * Binary incompatibility exists only when applications make direct access | |
202 * to the info_ptr or png_ptr members through png.h, and the compiled | |
203 * application is loaded with a different version of the library. | |
204 * | |
205 * DLLNUM will change each time there are forward or backward changes | |
206 * in binary compatibility (e.g., when a new feature is added). | |
207 * | |
208 * See libpng.txt or libpng.3 for more information. The PNG specification | |
209 * is available as a W3C Recommendation and as an ISO Specification, | |
210 * <http://www.w3.org/TR/2003/REC-PNG-20031110/ | |
211 */ | |
212 | |
213 /* | |
214 * Y2K compliance in libpng: | |
215 * ========================= | |
216 * | |
217 * December 3, 2015 | |
218 * | |
219 * Since the PNG Development group is an ad-hoc body, we can't make | |
220 * an official declaration. | |
221 * | |
222 * This is your unofficial assurance that libpng from version 0.71 and | |
223 * upward through 1.6.20 are Y2K compliant. It is my belief that | |
224 * earlier versions were also Y2K compliant. | |
225 * | |
226 * Libpng only has two year fields. One is a 2-byte unsigned integer | |
227 * that will hold years up to 65535. The other, which is deprecated, | |
228 * holds the date in text format, and will hold years up to 9999. | |
229 * | |
230 * The integer is | |
231 * "png_uint_16 year" in png_time_struct. | |
232 * | |
233 * The string is | |
234 * "char time_buffer[29]" in png_struct. This is no longer used | |
235 * in libpng-1.6.x and will be removed from libpng-1.7.0. | |
236 * | |
237 * There are seven time-related functions: | |
238 * png.c: png_convert_to_rfc_1123_buffer() in png.c | |
239 * (formerly png_convert_to_rfc_1123() prior to libpng-1.5.x and | |
240 * png_convert_to_rfc_1152() in error prior to libpng-0.98) | |
241 * png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c | |
242 * png_convert_from_time_t() in pngwrite.c | |
243 * png_get_tIME() in pngget.c | |
244 * png_handle_tIME() in pngrutil.c, called in pngread.c | |
245 * png_set_tIME() in pngset.c | |
246 * png_write_tIME() in pngwutil.c, called in pngwrite.c | |
247 * | |
248 * All handle dates properly in a Y2K environment. The | |
249 * png_convert_from_time_t() function calls gmtime() to convert from system | |
250 * clock time, which returns (year - 1900), which we properly convert to | |
251 * the full 4-digit year. There is a possibility that libpng applications | |
252 * are not passing 4-digit years into the png_convert_to_rfc_1123_buffer() | |
253 * function, or that they are incorrectly passing only a 2-digit year | |
254 * instead of "year - 1900" into the png_convert_from_struct_tm() function, | |
255 * but this is not under our control. The libpng documentation has always | |
256 * stated that it works with 4-digit years, and the APIs have been | |
257 * documented as such. | |
258 * | |
259 * The tIME chunk itself is also Y2K compliant. It uses a 2-byte unsigned | |
260 * integer to hold the year, and can hold years as large as 65535. | |
261 * | |
262 * zlib, upon which libpng depends, is also Y2K compliant. It contains | |
263 * no date-related code. | |
264 * | |
265 * Glenn Randers-Pehrson | |
266 * libpng maintainer | |
267 * PNG Development Group | |
268 */ | |
269 | |
270 #ifndef PNG_H | |
271 #define PNG_H | |
272 | |
273 /* This is not the place to learn how to use libpng. The file libpng-manual.txt | |
274 * describes how to use libpng, and the file example.c summarizes it | |
275 * with some code on which to build. This file is useful for looking | |
276 * at the actual function definitions and structure components. If that | |
277 * file has been stripped from your copy of libpng, you can find it at | |
278 * <http://www.libpng.org/pub/png/libpng-manual.txt> | |
279 * | |
280 * If you just need to read a PNG file and don't want to read the documentation | |
281 * skip to the end of this file and read the section entitled 'simplified API'. | |
282 */ | |
283 | |
284 /* Version information for png.h - this should match the version in png.c */ | |
285 #define PNG_LIBPNG_VER_STRING "1.6.20" | |
286 #define PNG_HEADER_VERSION_STRING \ | |
287 " libpng version 1.6.20 - December 3, 2015\n" | |
288 | |
289 #define PNG_LIBPNG_VER_SONUM 16 | |
290 #define PNG_LIBPNG_VER_DLLNUM 16 | |
291 | |
292 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */ | |
293 #define PNG_LIBPNG_VER_MAJOR 1 | |
294 #define PNG_LIBPNG_VER_MINOR 6 | |
295 #define PNG_LIBPNG_VER_RELEASE 20 | |
296 | |
297 /* This should match the numeric part of the final component of | |
298 * PNG_LIBPNG_VER_STRING, omitting any leading zero: | |
299 */ | |
300 | |
301 #define PNG_LIBPNG_VER_BUILD 0 | |
302 | |
303 /* Release Status */ | |
304 #define PNG_LIBPNG_BUILD_ALPHA 1 | |
305 #define PNG_LIBPNG_BUILD_BETA 2 | |
306 #define PNG_LIBPNG_BUILD_RC 3 | |
307 #define PNG_LIBPNG_BUILD_STABLE 4 | |
308 #define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7 | |
309 | |
310 /* Release-Specific Flags */ | |
311 #define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with | |
312 PNG_LIBPNG_BUILD_STABLE only */ | |
313 #define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with | |
314 PNG_LIBPNG_BUILD_SPECIAL */ | |
315 #define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with | |
316 PNG_LIBPNG_BUILD_PRIVATE */ | |
317 | |
318 #define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE | |
319 | |
320 /* Careful here. At one time, Guy wanted to use 082, but that would be octal. | |
321 * We must not include leading zeros. | |
322 * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only | |
323 * version 1.0.0 was mis-numbered 100 instead of 10000). From | |
324 * version 1.0.1 it's xxyyzz, where x=major, y=minor, z=release | |
325 */ | |
326 #define PNG_LIBPNG_VER 10620 /* 1.6.20 */ | |
327 | |
328 /* Library configuration: these options cannot be changed after | |
329 * the library has been built. | |
330 */ | |
331 #ifndef PNGLCONF_H | |
332 /* If pnglibconf.h is missing, you can | |
333 * copy scripts/pnglibconf.h.prebuilt to pnglibconf.h | |
334 */ | |
335 # include "pnglibconf.h" | |
336 #endif | |
337 | |
338 #ifndef PNG_VERSION_INFO_ONLY | |
339 /* Machine specific configuration. */ | |
340 # include "pngconf.h" | |
341 #endif | |
342 | |
343 /* | |
344 * Added at libpng-1.2.8 | |
345 * | |
346 * Ref MSDN: Private as priority over Special | |
347 * VS_FF_PRIVATEBUILD File *was not* built using standard release | |
348 * procedures. If this value is given, the StringFileInfo block must | |
349 * contain a PrivateBuild string. | |
350 * | |
351 * VS_FF_SPECIALBUILD File *was* built by the original company using | |
352 * standard release procedures but is a variation of the standard | |
353 * file of the same version number. If this value is given, the | |
354 * StringFileInfo block must contain a SpecialBuild string. | |
355 */ | |
356 | |
357 #ifdef PNG_USER_PRIVATEBUILD /* From pnglibconf.h */ | |
358 # define PNG_LIBPNG_BUILD_TYPE \ | |
359 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE) | |
360 #else | |
361 # ifdef PNG_LIBPNG_SPECIALBUILD | |
362 # define PNG_LIBPNG_BUILD_TYPE \ | |
363 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL) | |
364 # else | |
365 # define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE) | |
366 # endif | |
367 #endif | |
368 | |
369 #ifndef PNG_VERSION_INFO_ONLY | |
370 | |
371 /* Inhibit C++ name-mangling for libpng functions but not for system calls. */ | |
372 #ifdef __cplusplus | |
373 extern "C" { | |
374 #endif /* __cplusplus */ | |
375 | |
376 /* Version information for C files, stored in png.c. This had better match | |
377 * the version above. | |
378 */ | |
379 #define png_libpng_ver png_get_header_ver(NULL) | |
380 | |
381 /* This file is arranged in several sections: | |
382 * | |
383 * 1. [omitted] | |
384 * 2. Any configuration options that can be specified by for the application | |
385 * code when it is built. (Build time configuration is in pnglibconf.h) | |
386 * 3. Type definitions (base types are defined in pngconf.h), structure | |
387 * definitions. | |
388 * 4. Exported library functions. | |
389 * 5. Simplified API. | |
390 * 6. Implementation options. | |
391 * | |
392 * The library source code has additional files (principally pngpriv.h) that | |
393 * allow configuration of the library. | |
394 */ | |
395 | |
396 /* Section 1: [omitted] */ | |
397 | |
398 /* Section 2: run time configuration | |
399 * See pnglibconf.h for build time configuration | |
400 * | |
401 * Run time configuration allows the application to choose between | |
402 * implementations of certain arithmetic APIs. The default is set | |
403 * at build time and recorded in pnglibconf.h, but it is safe to | |
404 * override these (and only these) settings. Note that this won't | |
405 * change what the library does, only application code, and the | |
406 * settings can (and probably should) be made on a per-file basis | |
407 * by setting the #defines before including png.h | |
408 * | |
409 * Use macros to read integers from PNG data or use the exported | |
410 * functions? | |
411 * PNG_USE_READ_MACROS: use the macros (see below) Note that | |
412 * the macros evaluate their argument multiple times. | |
413 * PNG_NO_USE_READ_MACROS: call the relevant library function. | |
414 * | |
415 * Use the alternative algorithm for compositing alpha samples that | |
416 * does not use division? | |
417 * PNG_READ_COMPOSITE_NODIV_SUPPORTED: use the 'no division' | |
418 * algorithm. | |
419 * PNG_NO_READ_COMPOSITE_NODIV: use the 'division' algorithm. | |
420 * | |
421 * How to handle benign errors if PNG_ALLOW_BENIGN_ERRORS is | |
422 * false? | |
423 * PNG_ALLOW_BENIGN_ERRORS: map calls to the benign error | |
424 * APIs to png_warning. | |
425 * Otherwise the calls are mapped to png_error. | |
426 */ | |
427 | |
428 /* Section 3: type definitions, including structures and compile time | |
429 * constants. | |
430 * See pngconf.h for base types that vary by machine/system | |
431 */ | |
432 | |
433 /* This triggers a compiler error in png.c, if png.c and png.h | |
434 * do not agree upon the version number. | |
435 */ | |
436 typedef char* png_libpng_version_1_6_20; | |
437 | |
438 /* Basic control structions. Read libpng-manual.txt or libpng.3 for more info. | |
439 * | |
440 * png_struct is the cache of information used while reading or writing a single | |
441 * PNG file. One of these is always required, although the simplified API | |
442 * (below) hides the creation and destruction of it. | |
443 */ | |
444 typedef struct png_struct_def png_struct; | |
445 typedef const png_struct * png_const_structp; | |
446 typedef png_struct * png_structp; | |
447 typedef png_struct * * png_structpp; | |
448 | |
449 /* png_info contains information read from or to be written to a PNG file. One | |
450 * or more of these must exist while reading or creating a PNG file. The | |
451 * information is not used by libpng during read but is used to control what | |
452 * gets written when a PNG file is created. "png_get_" function calls read | |
453 * information during read and "png_set_" functions calls write information | |
454 * when creating a PNG. | |
455 * been moved into a separate header file that is not accessible to | |
456 * applications. Read libpng-manual.txt or libpng.3 for more info. | |
457 */ | |
458 typedef struct png_info_def png_info; | |
459 typedef png_info * png_infop; | |
460 typedef const png_info * png_const_infop; | |
461 typedef png_info * * png_infopp; | |
462 | |
463 /* Types with names ending 'p' are pointer types. The corresponding types with | |
464 * names ending 'rp' are identical pointer types except that the pointer is | |
465 * marked 'restrict', which means that it is the only pointer to the object | |
466 * passed to the function. Applications should not use the 'restrict' types; | |
467 * it is always valid to pass 'p' to a pointer with a function argument of the | |
468 * corresponding 'rp' type. Different compilers have different rules with | |
469 * regard to type matching in the presence of 'restrict'. For backward | |
470 * compatibility libpng callbacks never have 'restrict' in their parameters and, | |
471 * consequentially, writing portable application code is extremely difficult if | |
472 * an attempt is made to use 'restrict'. | |
473 */ | |
474 typedef png_struct * PNG_RESTRICT png_structrp; | |
475 typedef const png_struct * PNG_RESTRICT png_const_structrp; | |
476 typedef png_info * PNG_RESTRICT png_inforp; | |
477 typedef const png_info * PNG_RESTRICT png_const_inforp; | |
478 | |
479 /* Three color definitions. The order of the red, green, and blue, (and the | |
480 * exact size) is not important, although the size of the fields need to | |
481 * be png_byte or png_uint_16 (as defined below). | |
482 */ | |
483 typedef struct png_color_struct | |
484 { | |
485 png_byte red; | |
486 png_byte green; | |
487 png_byte blue; | |
488 } png_color; | |
489 typedef png_color * png_colorp; | |
490 typedef const png_color * png_const_colorp; | |
491 typedef png_color * * png_colorpp; | |
492 | |
493 typedef struct png_color_16_struct | |
494 { | |
495 png_byte index; /* used for palette files */ | |
496 png_uint_16 red; /* for use in red green blue files */ | |
497 png_uint_16 green; | |
498 png_uint_16 blue; | |
499 png_uint_16 gray; /* for use in grayscale files */ | |
500 } png_color_16; | |
501 typedef png_color_16 * png_color_16p; | |
502 typedef const png_color_16 * png_const_color_16p; | |
503 typedef png_color_16 * * png_color_16pp; | |
504 | |
505 typedef struct png_color_8_struct | |
506 { | |
507 png_byte red; /* for use in red green blue files */ | |
508 png_byte green; | |
509 png_byte blue; | |
510 png_byte gray; /* for use in grayscale files */ | |
511 png_byte alpha; /* for alpha channel files */ | |
512 } png_color_8; | |
513 typedef png_color_8 * png_color_8p; | |
514 typedef const png_color_8 * png_const_color_8p; | |
515 typedef png_color_8 * * png_color_8pp; | |
516 | |
517 /* | |
518 * The following two structures are used for the in-core representation | |
519 * of sPLT chunks. | |
520 */ | |
521 typedef struct png_sPLT_entry_struct | |
522 { | |
523 png_uint_16 red; | |
524 png_uint_16 green; | |
525 png_uint_16 blue; | |
526 png_uint_16 alpha; | |
527 png_uint_16 frequency; | |
528 } png_sPLT_entry; | |
529 typedef png_sPLT_entry * png_sPLT_entryp; | |
530 typedef const png_sPLT_entry * png_const_sPLT_entryp; | |
531 typedef png_sPLT_entry * * png_sPLT_entrypp; | |
532 | |
533 /* When the depth of the sPLT palette is 8 bits, the color and alpha samples | |
534 * occupy the LSB of their respective members, and the MSB of each member | |
535 * is zero-filled. The frequency member always occupies the full 16 bits. | |
536 */ | |
537 | |
538 typedef struct png_sPLT_struct | |
539 { | |
540 png_charp name; /* palette name */ | |
541 png_byte depth; /* depth of palette samples */ | |
542 png_sPLT_entryp entries; /* palette entries */ | |
543 png_int_32 nentries; /* number of palette entries */ | |
544 } png_sPLT_t; | |
545 typedef png_sPLT_t * png_sPLT_tp; | |
546 typedef const png_sPLT_t * png_const_sPLT_tp; | |
547 typedef png_sPLT_t * * png_sPLT_tpp; | |
548 | |
549 #ifdef PNG_TEXT_SUPPORTED | |
550 /* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file, | |
551 * and whether that contents is compressed or not. The "key" field | |
552 * points to a regular zero-terminated C string. The "text" fields can be a | |
553 * regular C string, an empty string, or a NULL pointer. | |
554 * However, the structure returned by png_get_text() will always contain | |
555 * the "text" field as a regular zero-terminated C string (possibly | |
556 * empty), never a NULL pointer, so it can be safely used in printf() and | |
557 * other string-handling functions. Note that the "itxt_length", "lang", and | |
558 * "lang_key" members of the structure only exist when the library is built | |
559 * with iTXt chunk support. Prior to libpng-1.4.0 the library was built by | |
560 * default without iTXt support. Also note that when iTXt *is* supported, | |
561 * the "lang" and "lang_key" fields contain NULL pointers when the | |
562 * "compression" field contains * PNG_TEXT_COMPRESSION_NONE or | |
563 * PNG_TEXT_COMPRESSION_zTXt. Note that the "compression value" is not the | |
564 * same as what appears in the PNG tEXt/zTXt/iTXt chunk's "compression flag" | |
565 * which is always 0 or 1, or its "compression method" which is always 0. | |
566 */ | |
567 typedef struct png_text_struct | |
568 { | |
569 int compression; /* compression value: | |
570 -1: tEXt, none | |
571 0: zTXt, deflate | |
572 1: iTXt, none | |
573 2: iTXt, deflate */ | |
574 png_charp key; /* keyword, 1-79 character description of "text" */ | |
575 png_charp text; /* comment, may be an empty string (ie "") | |
576 or a NULL pointer */ | |
577 png_size_t text_length; /* length of the text string */ | |
578 png_size_t itxt_length; /* length of the itxt string */ | |
579 png_charp lang; /* language code, 0-79 characters | |
580 or a NULL pointer */ | |
581 png_charp lang_key; /* keyword translated UTF-8 string, 0 or more | |
582 chars or a NULL pointer */ | |
583 } png_text; | |
584 typedef png_text * png_textp; | |
585 typedef const png_text * png_const_textp; | |
586 typedef png_text * * png_textpp; | |
587 #endif | |
588 | |
589 /* Supported compression types for text in PNG files (tEXt, and zTXt). | |
590 * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */ | |
591 #define PNG_TEXT_COMPRESSION_NONE_WR -3 | |
592 #define PNG_TEXT_COMPRESSION_zTXt_WR -2 | |
593 #define PNG_TEXT_COMPRESSION_NONE -1 | |
594 #define PNG_TEXT_COMPRESSION_zTXt 0 | |
595 #define PNG_ITXT_COMPRESSION_NONE 1 | |
596 #define PNG_ITXT_COMPRESSION_zTXt 2 | |
597 #define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */ | |
598 | |
599 /* png_time is a way to hold the time in an machine independent way. | |
600 * Two conversions are provided, both from time_t and struct tm. There | |
601 * is no portable way to convert to either of these structures, as far | |
602 * as I know. If you know of a portable way, send it to me. As a side | |
603 * note - PNG has always been Year 2000 compliant! | |
604 */ | |
605 typedef struct png_time_struct | |
606 { | |
607 png_uint_16 year; /* full year, as in, 1995 */ | |
608 png_byte month; /* month of year, 1 - 12 */ | |
609 png_byte day; /* day of month, 1 - 31 */ | |
610 png_byte hour; /* hour of day, 0 - 23 */ | |
611 png_byte minute; /* minute of hour, 0 - 59 */ | |
612 png_byte second; /* second of minute, 0 - 60 (for leap seconds) */ | |
613 } png_time; | |
614 typedef png_time * png_timep; | |
615 typedef const png_time * png_const_timep; | |
616 typedef png_time * * png_timepp; | |
617 | |
618 #if defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) ||\ | |
619 defined(PNG_USER_CHUNKS_SUPPORTED) | |
620 /* png_unknown_chunk is a structure to hold queued chunks for which there is | |
621 * no specific support. The idea is that we can use this to queue | |
622 * up private chunks for output even though the library doesn't actually | |
623 * know about their semantics. | |
624 * | |
625 * The data in the structure is set by libpng on read and used on write. | |
626 */ | |
627 typedef struct png_unknown_chunk_t | |
628 { | |
629 png_byte name[5]; /* Textual chunk name with '\0' terminator */ | |
630 png_byte *data; /* Data, should not be modified on read! */ | |
631 png_size_t size; | |
632 | |
633 /* On write 'location' must be set using the flag values listed below. | |
634 * Notice that on read it is set by libpng however the values stored have | |
635 * more bits set than are listed below. Always treat the value as a | |
636 * bitmask. On write set only one bit - setting multiple bits may cause the | |
637 * chunk to be written in multiple places. | |
638 */ | |
639 png_byte location; /* mode of operation at read time */ | |
640 } | |
641 png_unknown_chunk; | |
642 | |
643 typedef png_unknown_chunk * png_unknown_chunkp; | |
644 typedef const png_unknown_chunk * png_const_unknown_chunkp; | |
645 typedef png_unknown_chunk * * png_unknown_chunkpp; | |
646 #endif | |
647 | |
648 /* Flag values for the unknown chunk location byte. */ | |
649 #define PNG_HAVE_IHDR 0x01 | |
650 #define PNG_HAVE_PLTE 0x02 | |
651 #define PNG_AFTER_IDAT 0x08 | |
652 | |
653 /* Maximum positive integer used in PNG is (2^31)-1 */ | |
654 #define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL) | |
655 #define PNG_UINT_32_MAX ((png_uint_32)(-1)) | |
656 #define PNG_SIZE_MAX ((png_size_t)(-1)) | |
657 | |
658 /* These are constants for fixed point values encoded in the | |
659 * PNG specification manner (x100000) | |
660 */ | |
661 #define PNG_FP_1 100000 | |
662 #define PNG_FP_HALF 50000 | |
663 #define PNG_FP_MAX ((png_fixed_point)0x7fffffffL) | |
664 #define PNG_FP_MIN (-PNG_FP_MAX) | |
665 | |
666 /* These describe the color_type field in png_info. */ | |
667 /* color type masks */ | |
668 #define PNG_COLOR_MASK_PALETTE 1 | |
669 #define PNG_COLOR_MASK_COLOR 2 | |
670 #define PNG_COLOR_MASK_ALPHA 4 | |
671 | |
672 /* color types. Note that not all combinations are legal */ | |
673 #define PNG_COLOR_TYPE_GRAY 0 | |
674 #define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE) | |
675 #define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR) | |
676 #define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA) | |
677 #define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA) | |
678 /* aliases */ | |
679 #define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA | |
680 #define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA | |
681 | |
682 /* This is for compression type. PNG 1.0-1.2 only define the single type. */ | |
683 #define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */ | |
684 #define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE | |
685 | |
686 /* This is for filter type. PNG 1.0-1.2 only define the single type. */ | |
687 #define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */ | |
688 #define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */ | |
689 #define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE | |
690 | |
691 /* These are for the interlacing type. These values should NOT be changed. */ | |
692 #define PNG_INTERLACE_NONE 0 /* Non-interlaced image */ | |
693 #define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */ | |
694 #define PNG_INTERLACE_LAST 2 /* Not a valid value */ | |
695 | |
696 /* These are for the oFFs chunk. These values should NOT be changed. */ | |
697 #define PNG_OFFSET_PIXEL 0 /* Offset in pixels */ | |
698 #define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */ | |
699 #define PNG_OFFSET_LAST 2 /* Not a valid value */ | |
700 | |
701 /* These are for the pCAL chunk. These values should NOT be changed. */ | |
702 #define PNG_EQUATION_LINEAR 0 /* Linear transformation */ | |
703 #define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */ | |
704 #define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */ | |
705 #define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */ | |
706 #define PNG_EQUATION_LAST 4 /* Not a valid value */ | |
707 | |
708 /* These are for the sCAL chunk. These values should NOT be changed. */ | |
709 #define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */ | |
710 #define PNG_SCALE_METER 1 /* meters per pixel */ | |
711 #define PNG_SCALE_RADIAN 2 /* radians per pixel */ | |
712 #define PNG_SCALE_LAST 3 /* Not a valid value */ | |
713 | |
714 /* These are for the pHYs chunk. These values should NOT be changed. */ | |
715 #define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */ | |
716 #define PNG_RESOLUTION_METER 1 /* pixels/meter */ | |
717 #define PNG_RESOLUTION_LAST 2 /* Not a valid value */ | |
718 | |
719 /* These are for the sRGB chunk. These values should NOT be changed. */ | |
720 #define PNG_sRGB_INTENT_PERCEPTUAL 0 | |
721 #define PNG_sRGB_INTENT_RELATIVE 1 | |
722 #define PNG_sRGB_INTENT_SATURATION 2 | |
723 #define PNG_sRGB_INTENT_ABSOLUTE 3 | |
724 #define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */ | |
725 | |
726 /* This is for text chunks */ | |
727 #define PNG_KEYWORD_MAX_LENGTH 79 | |
728 | |
729 /* Maximum number of entries in PLTE/sPLT/tRNS arrays */ | |
730 #define PNG_MAX_PALETTE_LENGTH 256 | |
731 | |
732 /* These determine if an ancillary chunk's data has been successfully read | |
733 * from the PNG header, or if the application has filled in the corresponding | |
734 * data in the info_struct to be written into the output file. The values | |
735 * of the PNG_INFO_<chunk> defines should NOT be changed. | |
736 */ | |
737 #define PNG_INFO_gAMA 0x0001 | |
738 #define PNG_INFO_sBIT 0x0002 | |
739 #define PNG_INFO_cHRM 0x0004 | |
740 #define PNG_INFO_PLTE 0x0008 | |
741 #define PNG_INFO_tRNS 0x0010 | |
742 #define PNG_INFO_bKGD 0x0020 | |
743 #define PNG_INFO_hIST 0x0040 | |
744 #define PNG_INFO_pHYs 0x0080 | |
745 #define PNG_INFO_oFFs 0x0100 | |
746 #define PNG_INFO_tIME 0x0200 | |
747 #define PNG_INFO_pCAL 0x0400 | |
748 #define PNG_INFO_sRGB 0x0800 /* GR-P, 0.96a */ | |
749 #define PNG_INFO_iCCP 0x1000 /* ESR, 1.0.6 */ | |
750 #define PNG_INFO_sPLT 0x2000 /* ESR, 1.0.6 */ | |
751 #define PNG_INFO_sCAL 0x4000 /* ESR, 1.0.6 */ | |
752 #if INT_MAX >= 0x8000 /* else this might break */ | |
753 #define PNG_INFO_IDAT 0x8000 /* ESR, 1.0.6 */ | |
754 #endif | |
755 | |
756 /* This is used for the transformation routines, as some of them | |
757 * change these values for the row. It also should enable using | |
758 * the routines for other purposes. | |
759 */ | |
760 typedef struct png_row_info_struct | |
761 { | |
762 png_uint_32 width; /* width of row */ | |
763 png_size_t rowbytes; /* number of bytes in row */ | |
764 png_byte color_type; /* color type of row */ | |
765 png_byte bit_depth; /* bit depth of row */ | |
766 png_byte channels; /* number of channels (1, 2, 3, or 4) */ | |
767 png_byte pixel_depth; /* bits per pixel (depth * channels) */ | |
768 } png_row_info; | |
769 | |
770 typedef png_row_info * png_row_infop; | |
771 typedef png_row_info * * png_row_infopp; | |
772 | |
773 /* These are the function types for the I/O functions and for the functions | |
774 * that allow the user to override the default I/O functions with his or her | |
775 * own. The png_error_ptr type should match that of user-supplied warning | |
776 * and error functions, while the png_rw_ptr type should match that of the | |
777 * user read/write data functions. Note that the 'write' function must not | |
778 * modify the buffer it is passed. The 'read' function, on the other hand, is | |
779 * expected to return the read data in the buffer. | |
780 */ | |
781 typedef PNG_CALLBACK(void, *png_error_ptr, (png_structp, png_const_charp)); | |
782 typedef PNG_CALLBACK(void, *png_rw_ptr, (png_structp, png_bytep, png_size_t)); | |
783 typedef PNG_CALLBACK(void, *png_flush_ptr, (png_structp)); | |
784 typedef PNG_CALLBACK(void, *png_read_status_ptr, (png_structp, png_uint_32, | |
785 int)); | |
786 typedef PNG_CALLBACK(void, *png_write_status_ptr, (png_structp, png_uint_32, | |
787 int)); | |
788 | |
789 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED | |
790 typedef PNG_CALLBACK(void, *png_progressive_info_ptr, (png_structp, png_infop)); | |
791 typedef PNG_CALLBACK(void, *png_progressive_end_ptr, (png_structp, png_infop)); | |
792 | |
793 /* The following callback receives png_uint_32 row_number, int pass for the | |
794 * png_bytep data of the row. When transforming an interlaced image the | |
795 * row number is the row number within the sub-image of the interlace pass, so | |
796 * the value will increase to the height of the sub-image (not the full image) | |
797 * then reset to 0 for the next pass. | |
798 * | |
799 * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to | |
800 * find the output pixel (x,y) given an interlaced sub-image pixel | |
801 * (row,col,pass). (See below for these macros.) | |
802 */ | |
803 typedef PNG_CALLBACK(void, *png_progressive_row_ptr, (png_structp, png_bytep, | |
804 png_uint_32, int)); | |
805 #endif | |
806 | |
807 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ | |
808 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) | |
809 typedef PNG_CALLBACK(void, *png_user_transform_ptr, (png_structp, png_row_infop, | |
810 png_bytep)); | |
811 #endif | |
812 | |
813 #ifdef PNG_USER_CHUNKS_SUPPORTED | |
814 typedef PNG_CALLBACK(int, *png_user_chunk_ptr, (png_structp, | |
815 png_unknown_chunkp)); | |
816 #endif | |
817 #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED | |
818 /* not used anywhere */ | |
819 /* typedef PNG_CALLBACK(void, *png_unknown_chunk_ptr, (png_structp)); */ | |
820 #endif | |
821 | |
822 #ifdef PNG_SETJMP_SUPPORTED | |
823 /* This must match the function definition in <setjmp.h>, and the application | |
824 * must include this before png.h to obtain the definition of jmp_buf. The | |
825 * function is required to be PNG_NORETURN, but this is not checked. If the | |
826 * function does return the application will crash via an abort() or similar | |
827 * system level call. | |
828 * | |
829 * If you get a warning here while building the library you may need to make | |
830 * changes to ensure that pnglibconf.h records the calling convention used by | |
831 * your compiler. This may be very difficult - try using a different compiler | |
832 * to build the library! | |
833 */ | |
834 PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)), typedef); | |
835 #endif | |
836 | |
837 /* Transform masks for the high-level interface */ | |
838 #define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */ | |
839 #define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */ | |
840 #define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */ | |
841 #define PNG_TRANSFORM_PACKING 0x0004 /* read and write */ | |
842 #define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */ | |
843 #define PNG_TRANSFORM_EXPAND 0x0010 /* read only */ | |
844 #define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */ | |
845 #define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */ | |
846 #define PNG_TRANSFORM_BGR 0x0080 /* read and write */ | |
847 #define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */ | |
848 #define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */ | |
849 #define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */ | |
850 #define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* write only */ | |
851 /* Added to libpng-1.2.34 */ | |
852 #define PNG_TRANSFORM_STRIP_FILLER_BEFORE PNG_TRANSFORM_STRIP_FILLER | |
853 #define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */ | |
854 /* Added to libpng-1.4.0 */ | |
855 #define PNG_TRANSFORM_GRAY_TO_RGB 0x2000 /* read only */ | |
856 /* Added to libpng-1.5.4 */ | |
857 #define PNG_TRANSFORM_EXPAND_16 0x4000 /* read only */ | |
858 #if INT_MAX >= 0x8000 /* else this might break */ | |
859 #define PNG_TRANSFORM_SCALE_16 0x8000 /* read only */ | |
860 #endif | |
861 | |
862 /* Flags for MNG supported features */ | |
863 #define PNG_FLAG_MNG_EMPTY_PLTE 0x01 | |
864 #define PNG_FLAG_MNG_FILTER_64 0x04 | |
865 #define PNG_ALL_MNG_FEATURES 0x05 | |
866 | |
867 /* NOTE: prior to 1.5 these functions had no 'API' style declaration, | |
868 * this allowed the zlib default functions to be used on Windows | |
869 * platforms. In 1.5 the zlib default malloc (which just calls malloc and | |
870 * ignores the first argument) should be completely compatible with the | |
871 * following. | |
872 */ | |
873 typedef PNG_CALLBACK(png_voidp, *png_malloc_ptr, (png_structp, | |
874 png_alloc_size_t)); | |
875 typedef PNG_CALLBACK(void, *png_free_ptr, (png_structp, png_voidp)); | |
876 | |
877 /* Section 4: exported functions | |
878 * Here are the function definitions most commonly used. This is not | |
879 * the place to find out how to use libpng. See libpng-manual.txt for the | |
880 * full explanation, see example.c for the summary. This just provides | |
881 * a simple one line description of the use of each function. | |
882 * | |
883 * The PNG_EXPORT() and PNG_EXPORTA() macros used below are defined in | |
884 * pngconf.h and in the *.dfn files in the scripts directory. | |
885 * | |
886 * PNG_EXPORT(ordinal, type, name, (args)); | |
887 * | |
888 * ordinal: ordinal that is used while building | |
889 * *.def files. The ordinal value is only | |
890 * relevant when preprocessing png.h with | |
891 * the *.dfn files for building symbol table | |
892 * entries, and are removed by pngconf.h. | |
893 * type: return type of the function | |
894 * name: function name | |
895 * args: function arguments, with types | |
896 * | |
897 * When we wish to append attributes to a function prototype we use | |
898 * the PNG_EXPORTA() macro instead. | |
899 * | |
900 * PNG_EXPORTA(ordinal, type, name, (args), attributes); | |
901 * | |
902 * ordinal, type, name, and args: same as in PNG_EXPORT(). | |
903 * attributes: function attributes | |
904 */ | |
905 | |
906 /* Returns the version number of the library */ | |
907 PNG_EXPORT(1, png_uint_32, png_access_version_number, (void)); | |
908 | |
909 /* Tell lib we have already handled the first <num_bytes> magic bytes. | |
910 * Handling more than 8 bytes from the beginning of the file is an error. | |
911 */ | |
912 PNG_EXPORT(2, void, png_set_sig_bytes, (png_structrp png_ptr, int num_bytes)); | |
913 | |
914 /* Check sig[start] through sig[start + num_to_check - 1] to see if it's a | |
915 * PNG file. Returns zero if the supplied bytes match the 8-byte PNG | |
916 * signature, and non-zero otherwise. Having num_to_check == 0 or | |
917 * start > 7 will always fail (ie return non-zero). | |
918 */ | |
919 PNG_EXPORT(3, int, png_sig_cmp, (png_const_bytep sig, png_size_t start, | |
920 png_size_t num_to_check)); | |
921 | |
922 /* Simple signature checking function. This is the same as calling | |
923 * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n). | |
924 */ | |
925 #define png_check_sig(sig, n) !png_sig_cmp((sig), 0, (n)) | |
926 | |
927 /* Allocate and initialize png_ptr struct for reading, and any other memory. */ | |
928 PNG_EXPORTA(4, png_structp, png_create_read_struct, | |
929 (png_const_charp user_png_ver, png_voidp error_ptr, | |
930 png_error_ptr error_fn, png_error_ptr warn_fn), | |
931 PNG_ALLOCATED); | |
932 | |
933 /* Allocate and initialize png_ptr struct for writing, and any other memory */ | |
934 PNG_EXPORTA(5, png_structp, png_create_write_struct, | |
935 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, | |
936 png_error_ptr warn_fn), | |
937 PNG_ALLOCATED); | |
938 | |
939 PNG_EXPORT(6, png_size_t, png_get_compression_buffer_size, | |
940 (png_const_structrp png_ptr)); | |
941 | |
942 PNG_EXPORT(7, void, png_set_compression_buffer_size, (png_structrp png_ptr, | |
943 png_size_t size)); | |
944 | |
945 /* Moved from pngconf.h in 1.4.0 and modified to ensure setjmp/longjmp | |
946 * match up. | |
947 */ | |
948 #ifdef PNG_SETJMP_SUPPORTED | |
949 /* This function returns the jmp_buf built in to *png_ptr. It must be | |
950 * supplied with an appropriate 'longjmp' function to use on that jmp_buf | |
951 * unless the default error function is overridden in which case NULL is | |
952 * acceptable. The size of the jmp_buf is checked against the actual size | |
953 * allocated by the library - the call will return NULL on a mismatch | |
954 * indicating an ABI mismatch. | |
955 */ | |
956 PNG_EXPORT(8, jmp_buf*, png_set_longjmp_fn, (png_structrp png_ptr, | |
957 png_longjmp_ptr longjmp_fn, size_t jmp_buf_size)); | |
958 # define png_jmpbuf(png_ptr) \ | |
959 (*png_set_longjmp_fn((png_ptr), longjmp, (sizeof (jmp_buf)))) | |
960 #else | |
961 # define png_jmpbuf(png_ptr) \ | |
962 (LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP) | |
963 #endif | |
964 /* This function should be used by libpng applications in place of | |
965 * longjmp(png_ptr->jmpbuf, val). If longjmp_fn() has been set, it | |
966 * will use it; otherwise it will call PNG_ABORT(). This function was | |
967 * added in libpng-1.5.0. | |
968 */ | |
969 PNG_EXPORTA(9, void, png_longjmp, (png_const_structrp png_ptr, int val), | |
970 PNG_NORETURN); | |
971 | |
972 #ifdef PNG_READ_SUPPORTED | |
973 /* Reset the compression stream */ | |
974 PNG_EXPORTA(10, int, png_reset_zstream, (png_structrp png_ptr), PNG_DEPRECATED); | |
975 #endif | |
976 | |
977 /* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */ | |
978 #ifdef PNG_USER_MEM_SUPPORTED | |
979 PNG_EXPORTA(11, png_structp, png_create_read_struct_2, | |
980 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, | |
981 png_error_ptr warn_fn, | |
982 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn), | |
983 PNG_ALLOCATED); | |
984 PNG_EXPORTA(12, png_structp, png_create_write_struct_2, | |
985 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, | |
986 png_error_ptr warn_fn, | |
987 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn), | |
988 PNG_ALLOCATED); | |
989 #endif | |
990 | |
991 /* Write the PNG file signature. */ | |
992 PNG_EXPORT(13, void, png_write_sig, (png_structrp png_ptr)); | |
993 | |
994 /* Write a PNG chunk - size, type, (optional) data, CRC. */ | |
995 PNG_EXPORT(14, void, png_write_chunk, (png_structrp png_ptr, png_const_bytep | |
996 chunk_name, png_const_bytep data, png_size_t length)); | |
997 | |
998 /* Write the start of a PNG chunk - length and chunk name. */ | |
999 PNG_EXPORT(15, void, png_write_chunk_start, (png_structrp png_ptr, | |
1000 png_const_bytep chunk_name, png_uint_32 length)); | |
1001 | |
1002 /* Write the data of a PNG chunk started with png_write_chunk_start(). */ | |
1003 PNG_EXPORT(16, void, png_write_chunk_data, (png_structrp png_ptr, | |
1004 png_const_bytep data, png_size_t length)); | |
1005 | |
1006 /* Finish a chunk started with png_write_chunk_start() (includes CRC). */ | |
1007 PNG_EXPORT(17, void, png_write_chunk_end, (png_structrp png_ptr)); | |
1008 | |
1009 /* Allocate and initialize the info structure */ | |
1010 PNG_EXPORTA(18, png_infop, png_create_info_struct, (png_const_structrp png_ptr), | |
1011 PNG_ALLOCATED); | |
1012 | |
1013 /* DEPRECATED: this function allowed init structures to be created using the | |
1014 * default allocation method (typically malloc). Use is deprecated in 1.6.0 and | |
1015 * the API will be removed in the future. | |
1016 */ | |
1017 PNG_EXPORTA(19, void, png_info_init_3, (png_infopp info_ptr, | |
1018 png_size_t png_info_struct_size), PNG_DEPRECATED); | |
1019 | |
1020 /* Writes all the PNG information before the image. */ | |
1021 PNG_EXPORT(20, void, png_write_info_before_PLTE, | |
1022 (png_structrp png_ptr, png_const_inforp info_ptr)); | |
1023 PNG_EXPORT(21, void, png_write_info, | |
1024 (png_structrp png_ptr, png_const_inforp info_ptr)); | |
1025 | |
1026 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED | |
1027 /* Read the information before the actual image data. */ | |
1028 PNG_EXPORT(22, void, png_read_info, | |
1029 (png_structrp png_ptr, png_inforp info_ptr)); | |
1030 #endif | |
1031 | |
1032 #ifdef PNG_TIME_RFC1123_SUPPORTED | |
1033 /* Convert to a US string format: there is no localization support in this | |
1034 * routine. The original implementation used a 29 character buffer in | |
1035 * png_struct, this will be removed in future versions. | |
1036 */ | |
1037 #if PNG_LIBPNG_VER < 10700 | |
1038 /* To do: remove this from libpng17 (and from libpng17/png.c and pngstruct.h) */ | |
1039 PNG_EXPORTA(23, png_const_charp, png_convert_to_rfc1123, (png_structrp png_ptr, | |
1040 png_const_timep ptime),PNG_DEPRECATED); | |
1041 #endif | |
1042 PNG_EXPORT(241, int, png_convert_to_rfc1123_buffer, (char out[29], | |
1043 png_const_timep ptime)); | |
1044 #endif | |
1045 | |
1046 #ifdef PNG_CONVERT_tIME_SUPPORTED | |
1047 /* Convert from a struct tm to png_time */ | |
1048 PNG_EXPORT(24, void, png_convert_from_struct_tm, (png_timep ptime, | |
1049 const struct tm * ttime)); | |
1050 | |
1051 /* Convert from time_t to png_time. Uses gmtime() */ | |
1052 PNG_EXPORT(25, void, png_convert_from_time_t, (png_timep ptime, time_t ttime)); | |
1053 #endif /* CONVERT_tIME */ | |
1054 | |
1055 #ifdef PNG_READ_EXPAND_SUPPORTED | |
1056 /* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */ | |
1057 PNG_EXPORT(26, void, png_set_expand, (png_structrp png_ptr)); | |
1058 PNG_EXPORT(27, void, png_set_expand_gray_1_2_4_to_8, (png_structrp png_ptr)); | |
1059 PNG_EXPORT(28, void, png_set_palette_to_rgb, (png_structrp png_ptr)); | |
1060 PNG_EXPORT(29, void, png_set_tRNS_to_alpha, (png_structrp png_ptr)); | |
1061 #endif | |
1062 | |
1063 #ifdef PNG_READ_EXPAND_16_SUPPORTED | |
1064 /* Expand to 16-bit channels, forces conversion of palette to RGB and expansion | |
1065 * of a tRNS chunk if present. | |
1066 */ | |
1067 PNG_EXPORT(221, void, png_set_expand_16, (png_structrp png_ptr)); | |
1068 #endif | |
1069 | |
1070 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED) | |
1071 /* Use blue, green, red order for pixels. */ | |
1072 PNG_EXPORT(30, void, png_set_bgr, (png_structrp png_ptr)); | |
1073 #endif | |
1074 | |
1075 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED | |
1076 /* Expand the grayscale to 24-bit RGB if necessary. */ | |
1077 PNG_EXPORT(31, void, png_set_gray_to_rgb, (png_structrp png_ptr)); | |
1078 #endif | |
1079 | |
1080 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED | |
1081 /* Reduce RGB to grayscale. */ | |
1082 #define PNG_ERROR_ACTION_NONE 1 | |
1083 #define PNG_ERROR_ACTION_WARN 2 | |
1084 #define PNG_ERROR_ACTION_ERROR 3 | |
1085 #define PNG_RGB_TO_GRAY_DEFAULT (-1)/*for red/green coefficients*/ | |
1086 | |
1087 PNG_FP_EXPORT(32, void, png_set_rgb_to_gray, (png_structrp png_ptr, | |
1088 int error_action, double red, double green)) | |
1089 PNG_FIXED_EXPORT(33, void, png_set_rgb_to_gray_fixed, (png_structrp png_ptr, | |
1090 int error_action, png_fixed_point red, png_fixed_point green)) | |
1091 | |
1092 PNG_EXPORT(34, png_byte, png_get_rgb_to_gray_status, (png_const_structrp | |
1093 png_ptr)); | |
1094 #endif | |
1095 | |
1096 #ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED | |
1097 PNG_EXPORT(35, void, png_build_grayscale_palette, (int bit_depth, | |
1098 png_colorp palette)); | |
1099 #endif | |
1100 | |
1101 #ifdef PNG_READ_ALPHA_MODE_SUPPORTED | |
1102 /* How the alpha channel is interpreted - this affects how the color channels | |
1103 * of a PNG file are returned to the calling application when an alpha channel, | |
1104 * or a tRNS chunk in a palette file, is present. | |
1105 * | |
1106 * This has no effect on the way pixels are written into a PNG output | |
1107 * datastream. The color samples in a PNG datastream are never premultiplied | |
1108 * with the alpha samples. | |
1109 * | |
1110 * The default is to return data according to the PNG specification: the alpha | |
1111 * channel is a linear measure of the contribution of the pixel to the | |
1112 * corresponding composited pixel, and the color channels are unassociated | |
1113 * (not premultiplied). The gamma encoded color channels must be scaled | |
1114 * according to the contribution and to do this it is necessary to undo | |
1115 * the encoding, scale the color values, perform the composition and reencode | |
1116 * the values. This is the 'PNG' mode. | |
1117 * | |
1118 * The alternative is to 'associate' the alpha with the color information by | |
1119 * storing color channel values that have been scaled by the alpha. | |
1120 * image. These are the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' modes | |
1121 * (the latter being the two common names for associated alpha color channels). | |
1122 * | |
1123 * For the 'OPTIMIZED' mode, a pixel is treated as opaque only if the alpha | |
1124 * value is equal to the maximum value. | |
1125 * | |
1126 * The final choice is to gamma encode the alpha channel as well. This is | |
1127 * broken because, in practice, no implementation that uses this choice | |
1128 * correctly undoes the encoding before handling alpha composition. Use this | |
1129 * choice only if other serious errors in the software or hardware you use | |
1130 * mandate it; the typical serious error is for dark halos to appear around | |
1131 * opaque areas of the composited PNG image because of arithmetic overflow. | |
1132 * | |
1133 * The API function png_set_alpha_mode specifies which of these choices to use | |
1134 * with an enumerated 'mode' value and the gamma of the required output: | |
1135 */ | |
1136 #define PNG_ALPHA_PNG 0 /* according to the PNG standard */ | |
1137 #define PNG_ALPHA_STANDARD 1 /* according to Porter/Duff */ | |
1138 #define PNG_ALPHA_ASSOCIATED 1 /* as above; this is the normal practice */ | |
1139 #define PNG_ALPHA_PREMULTIPLIED 1 /* as above */ | |
1140 #define PNG_ALPHA_OPTIMIZED 2 /* 'PNG' for opaque pixels, else 'STANDARD' */ | |
1141 #define PNG_ALPHA_BROKEN 3 /* the alpha channel is gamma encoded */ | |
1142 | |
1143 PNG_FP_EXPORT(227, void, png_set_alpha_mode, (png_structrp png_ptr, int mode, | |
1144 double output_gamma)) | |
1145 PNG_FIXED_EXPORT(228, void, png_set_alpha_mode_fixed, (png_structrp png_ptr, | |
1146 int mode, png_fixed_point output_gamma)) | |
1147 #endif | |
1148 | |
1149 #if defined(PNG_GAMMA_SUPPORTED) || defined(PNG_READ_ALPHA_MODE_SUPPORTED) | |
1150 /* The output_gamma value is a screen gamma in libpng terminology: it expresses | |
1151 * how to decode the output values, not how they are encoded. | |
1152 */ | |
1153 #define PNG_DEFAULT_sRGB -1 /* sRGB gamma and color space */ | |
1154 #define PNG_GAMMA_MAC_18 -2 /* Old Mac '1.8' gamma and color space */ | |
1155 #define PNG_GAMMA_sRGB 220000 /* Television standards--matches sRGB gamma */ | |
1156 #define PNG_GAMMA_LINEAR PNG_FP_1 /* Linear */ | |
1157 #endif | |
1158 | |
1159 /* The following are examples of calls to png_set_alpha_mode to achieve the | |
1160 * required overall gamma correction and, where necessary, alpha | |
1161 * premultiplication. | |
1162 * | |
1163 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB); | |
1164 * This is the default libpng handling of the alpha channel - it is not | |
1165 * pre-multiplied into the color components. In addition the call states | |
1166 * that the output is for a sRGB system and causes all PNG files without gAMA | |
1167 * chunks to be assumed to be encoded using sRGB. | |
1168 * | |
1169 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC); | |
1170 * In this case the output is assumed to be something like an sRGB conformant | |
1171 * display preceeded by a power-law lookup table of power 1.45. This is how | |
1172 * early Mac systems behaved. | |
1173 * | |
1174 * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR); | |
1175 * This is the classic Jim Blinn approach and will work in academic | |
1176 * environments where everything is done by the book. It has the shortcoming | |
1177 * of assuming that input PNG data with no gamma information is linear - this | |
1178 * is unlikely to be correct unless the PNG files where generated locally. | |
1179 * Most of the time the output precision will be so low as to show | |
1180 * significant banding in dark areas of the image. | |
1181 * | |
1182 * png_set_expand_16(pp); | |
1183 * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB); | |
1184 * This is a somewhat more realistic Jim Blinn inspired approach. PNG files | |
1185 * are assumed to have the sRGB encoding if not marked with a gamma value and | |
1186 * the output is always 16 bits per component. This permits accurate scaling | |
1187 * and processing of the data. If you know that your input PNG files were | |
1188 * generated locally you might need to replace PNG_DEFAULT_sRGB with the | |
1189 * correct value for your system. | |
1190 * | |
1191 * png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB); | |
1192 * If you just need to composite the PNG image onto an existing background | |
1193 * and if you control the code that does this you can use the optimization | |
1194 * setting. In this case you just copy completely opaque pixels to the | |
1195 * output. For pixels that are not completely transparent (you just skip | |
1196 * those) you do the composition math using png_composite or png_composite_16 | |
1197 * below then encode the resultant 8-bit or 16-bit values to match the output | |
1198 * encoding. | |
1199 * | |
1200 * Other cases | |
1201 * If neither the PNG nor the standard linear encoding work for you because | |
1202 * of the software or hardware you use then you have a big problem. The PNG | |
1203 * case will probably result in halos around the image. The linear encoding | |
1204 * will probably result in a washed out, too bright, image (it's actually too | |
1205 * contrasty.) Try the ALPHA_OPTIMIZED mode above - this will probably | |
1206 * substantially reduce the halos. Alternatively try: | |
1207 * | |
1208 * png_set_alpha_mode(pp, PNG_ALPHA_BROKEN, PNG_DEFAULT_sRGB); | |
1209 * This option will also reduce the halos, but there will be slight dark | |
1210 * halos round the opaque parts of the image where the background is light. | |
1211 * In the OPTIMIZED mode the halos will be light halos where the background | |
1212 * is dark. Take your pick - the halos are unavoidable unless you can get | |
1213 * your hardware/software fixed! (The OPTIMIZED approach is slightly | |
1214 * faster.) | |
1215 * | |
1216 * When the default gamma of PNG files doesn't match the output gamma. | |
1217 * If you have PNG files with no gamma information png_set_alpha_mode allows | |
1218 * you to provide a default gamma, but it also sets the ouput gamma to the | |
1219 * matching value. If you know your PNG files have a gamma that doesn't | |
1220 * match the output you can take advantage of the fact that | |
1221 * png_set_alpha_mode always sets the output gamma but only sets the PNG | |
1222 * default if it is not already set: | |
1223 * | |
1224 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB); | |
1225 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC); | |
1226 * The first call sets both the default and the output gamma values, the | |
1227 * second call overrides the output gamma without changing the default. This | |
1228 * is easier than achieving the same effect with png_set_gamma. You must use | |
1229 * PNG_ALPHA_PNG for the first call - internal checking in png_set_alpha will | |
1230 * fire if more than one call to png_set_alpha_mode and png_set_background is | |
1231 * made in the same read operation, however multiple calls with PNG_ALPHA_PNG | |
1232 * are ignored. | |
1233 */ | |
1234 | |
1235 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED | |
1236 PNG_EXPORT(36, void, png_set_strip_alpha, (png_structrp png_ptr)); | |
1237 #endif | |
1238 | |
1239 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \ | |
1240 defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED) | |
1241 PNG_EXPORT(37, void, png_set_swap_alpha, (png_structrp png_ptr)); | |
1242 #endif | |
1243 | |
1244 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \ | |
1245 defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED) | |
1246 PNG_EXPORT(38, void, png_set_invert_alpha, (png_structrp png_ptr)); | |
1247 #endif | |
1248 | |
1249 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED) | |
1250 /* Add a filler byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */ | |
1251 PNG_EXPORT(39, void, png_set_filler, (png_structrp png_ptr, png_uint_32 filler, | |
1252 int flags)); | |
1253 /* The values of the PNG_FILLER_ defines should NOT be changed */ | |
1254 # define PNG_FILLER_BEFORE 0 | |
1255 # define PNG_FILLER_AFTER 1 | |
1256 /* Add an alpha byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */ | |
1257 PNG_EXPORT(40, void, png_set_add_alpha, (png_structrp png_ptr, | |
1258 png_uint_32 filler, int flags)); | |
1259 #endif /* READ_FILLER || WRITE_FILLER */ | |
1260 | |
1261 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED) | |
1262 /* Swap bytes in 16-bit depth files. */ | |
1263 PNG_EXPORT(41, void, png_set_swap, (png_structrp png_ptr)); | |
1264 #endif | |
1265 | |
1266 #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED) | |
1267 /* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */ | |
1268 PNG_EXPORT(42, void, png_set_packing, (png_structrp png_ptr)); | |
1269 #endif | |
1270 | |
1271 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || \ | |
1272 defined(PNG_WRITE_PACKSWAP_SUPPORTED) | |
1273 /* Swap packing order of pixels in bytes. */ | |
1274 PNG_EXPORT(43, void, png_set_packswap, (png_structrp png_ptr)); | |
1275 #endif | |
1276 | |
1277 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED) | |
1278 /* Converts files to legal bit depths. */ | |
1279 PNG_EXPORT(44, void, png_set_shift, (png_structrp png_ptr, png_const_color_8p | |
1280 true_bits)); | |
1281 #endif | |
1282 | |
1283 #if defined(PNG_READ_INTERLACING_SUPPORTED) || \ | |
1284 defined(PNG_WRITE_INTERLACING_SUPPORTED) | |
1285 /* Have the code handle the interlacing. Returns the number of passes. | |
1286 * MUST be called before png_read_update_info or png_start_read_image, | |
1287 * otherwise it will not have the desired effect. Note that it is still | |
1288 * necessary to call png_read_row or png_read_rows png_get_image_height | |
1289 * times for each pass. | |
1290 */ | |
1291 PNG_EXPORT(45, int, png_set_interlace_handling, (png_structrp png_ptr)); | |
1292 #endif | |
1293 | |
1294 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED) | |
1295 /* Invert monochrome files */ | |
1296 PNG_EXPORT(46, void, png_set_invert_mono, (png_structrp png_ptr)); | |
1297 #endif | |
1298 | |
1299 #ifdef PNG_READ_BACKGROUND_SUPPORTED | |
1300 /* Handle alpha and tRNS by replacing with a background color. Prior to | |
1301 * libpng-1.5.4 this API must not be called before the PNG file header has been | |
1302 * read. Doing so will result in unexpected behavior and possible warnings or | |
1303 * errors if the PNG file contains a bKGD chunk. | |
1304 */ | |
1305 PNG_FP_EXPORT(47, void, png_set_background, (png_structrp png_ptr, | |
1306 png_const_color_16p background_color, int background_gamma_code, | |
1307 int need_expand, double background_gamma)) | |
1308 PNG_FIXED_EXPORT(215, void, png_set_background_fixed, (png_structrp png_ptr, | |
1309 png_const_color_16p background_color, int background_gamma_code, | |
1310 int need_expand, png_fixed_point background_gamma)) | |
1311 #endif | |
1312 #ifdef PNG_READ_BACKGROUND_SUPPORTED | |
1313 # define PNG_BACKGROUND_GAMMA_UNKNOWN 0 | |
1314 # define PNG_BACKGROUND_GAMMA_SCREEN 1 | |
1315 # define PNG_BACKGROUND_GAMMA_FILE 2 | |
1316 # define PNG_BACKGROUND_GAMMA_UNIQUE 3 | |
1317 #endif | |
1318 | |
1319 #ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED | |
1320 /* Scale a 16-bit depth file down to 8-bit, accurately. */ | |
1321 PNG_EXPORT(229, void, png_set_scale_16, (png_structrp png_ptr)); | |
1322 #endif | |
1323 | |
1324 #ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED | |
1325 #define PNG_READ_16_TO_8 SUPPORTED /* Name prior to 1.5.4 */ | |
1326 /* Strip the second byte of information from a 16-bit depth file. */ | |
1327 PNG_EXPORT(48, void, png_set_strip_16, (png_structrp png_ptr)); | |
1328 #endif | |
1329 | |
1330 #ifdef PNG_READ_QUANTIZE_SUPPORTED | |
1331 /* Turn on quantizing, and reduce the palette to the number of colors | |
1332 * available. | |
1333 */ | |
1334 PNG_EXPORT(49, void, png_set_quantize, (png_structrp png_ptr, | |
1335 png_colorp palette, int num_palette, int maximum_colors, | |
1336 png_const_uint_16p histogram, int full_quantize)); | |
1337 #endif | |
1338 | |
1339 #ifdef PNG_READ_GAMMA_SUPPORTED | |
1340 /* The threshold on gamma processing is configurable but hard-wired into the | |
1341 * library. The following is the floating point variant. | |
1342 */ | |
1343 #define PNG_GAMMA_THRESHOLD (PNG_GAMMA_THRESHOLD_FIXED*.00001) | |
1344 | |
1345 /* Handle gamma correction. Screen_gamma=(display_exponent). | |
1346 * NOTE: this API simply sets the screen and file gamma values. It will | |
1347 * therefore override the value for gamma in a PNG file if it is called after | |
1348 * the file header has been read - use with care - call before reading the PNG | |
1349 * file for best results! | |
1350 * | |
1351 * These routines accept the same gamma values as png_set_alpha_mode (described | |
1352 * above). The PNG_GAMMA_ defines and PNG_DEFAULT_sRGB can be passed to either | |
1353 * API (floating point or fixed.) Notice, however, that the 'file_gamma' value | |
1354 * is the inverse of a 'screen gamma' value. | |
1355 */ | |
1356 PNG_FP_EXPORT(50, void, png_set_gamma, (png_structrp png_ptr, | |
1357 double screen_gamma, double override_file_gamma)) | |
1358 PNG_FIXED_EXPORT(208, void, png_set_gamma_fixed, (png_structrp png_ptr, | |
1359 png_fixed_point screen_gamma, png_fixed_point override_file_gamma)) | |
1360 #endif | |
1361 | |
1362 #ifdef PNG_WRITE_FLUSH_SUPPORTED | |
1363 /* Set how many lines between output flushes - 0 for no flushing */ | |
1364 PNG_EXPORT(51, void, png_set_flush, (png_structrp png_ptr, int nrows)); | |
1365 /* Flush the current PNG output buffer */ | |
1366 PNG_EXPORT(52, void, png_write_flush, (png_structrp png_ptr)); | |
1367 #endif | |
1368 | |
1369 /* Optional update palette with requested transformations */ | |
1370 PNG_EXPORT(53, void, png_start_read_image, (png_structrp png_ptr)); | |
1371 | |
1372 /* Optional call to update the users info structure */ | |
1373 PNG_EXPORT(54, void, png_read_update_info, (png_structrp png_ptr, | |
1374 png_inforp info_ptr)); | |
1375 | |
1376 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED | |
1377 /* Read one or more rows of image data. */ | |
1378 PNG_EXPORT(55, void, png_read_rows, (png_structrp png_ptr, png_bytepp row, | |
1379 png_bytepp display_row, png_uint_32 num_rows)); | |
1380 #endif | |
1381 | |
1382 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED | |
1383 /* Read a row of data. */ | |
1384 PNG_EXPORT(56, void, png_read_row, (png_structrp png_ptr, png_bytep row, | |
1385 png_bytep display_row)); | |
1386 #endif | |
1387 | |
1388 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED | |
1389 /* Read the whole image into memory at once. */ | |
1390 PNG_EXPORT(57, void, png_read_image, (png_structrp png_ptr, png_bytepp image)); | |
1391 #endif | |
1392 | |
1393 /* Write a row of image data */ | |
1394 PNG_EXPORT(58, void, png_write_row, (png_structrp png_ptr, | |
1395 png_const_bytep row)); | |
1396 | |
1397 /* Write a few rows of image data: (*row) is not written; however, the type | |
1398 * is declared as writeable to maintain compatibility with previous versions | |
1399 * of libpng and to allow the 'display_row' array from read_rows to be passed | |
1400 * unchanged to write_rows. | |
1401 */ | |
1402 PNG_EXPORT(59, void, png_write_rows, (png_structrp png_ptr, png_bytepp row, | |
1403 png_uint_32 num_rows)); | |
1404 | |
1405 /* Write the image data */ | |
1406 PNG_EXPORT(60, void, png_write_image, (png_structrp png_ptr, png_bytepp image)); | |
1407 | |
1408 /* Write the end of the PNG file. */ | |
1409 PNG_EXPORT(61, void, png_write_end, (png_structrp png_ptr, | |
1410 png_inforp info_ptr)); | |
1411 | |
1412 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED | |
1413 /* Read the end of the PNG file. */ | |
1414 PNG_EXPORT(62, void, png_read_end, (png_structrp png_ptr, png_inforp info_ptr)); | |
1415 #endif | |
1416 | |
1417 /* Free any memory associated with the png_info_struct */ | |
1418 PNG_EXPORT(63, void, png_destroy_info_struct, (png_const_structrp png_ptr, | |
1419 png_infopp info_ptr_ptr)); | |
1420 | |
1421 /* Free any memory associated with the png_struct and the png_info_structs */ | |
1422 PNG_EXPORT(64, void, png_destroy_read_struct, (png_structpp png_ptr_ptr, | |
1423 png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr)); | |
1424 | |
1425 /* Free any memory associated with the png_struct and the png_info_structs */ | |
1426 PNG_EXPORT(65, void, png_destroy_write_struct, (png_structpp png_ptr_ptr, | |
1427 png_infopp info_ptr_ptr)); | |
1428 | |
1429 /* Set the libpng method of handling chunk CRC errors */ | |
1430 PNG_EXPORT(66, void, png_set_crc_action, (png_structrp png_ptr, int crit_action, | |
1431 int ancil_action)); | |
1432 | |
1433 /* Values for png_set_crc_action() say how to handle CRC errors in | |
1434 * ancillary and critical chunks, and whether to use the data contained | |
1435 * therein. Note that it is impossible to "discard" data in a critical | |
1436 * chunk. For versions prior to 0.90, the action was always error/quit, | |
1437 * whereas in version 0.90 and later, the action for CRC errors in ancillary | |
1438 * chunks is warn/discard. These values should NOT be changed. | |
1439 * | |
1440 * value action:critical action:ancillary | |
1441 */ | |
1442 #define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */ | |
1443 #define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */ | |
1444 #define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */ | |
1445 #define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */ | |
1446 #define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */ | |
1447 #define PNG_CRC_NO_CHANGE 5 /* use current value use current value */ | |
1448 | |
1449 #ifdef PNG_WRITE_SUPPORTED | |
1450 /* These functions give the user control over the scan-line filtering in | |
1451 * libpng and the compression methods used by zlib. These functions are | |
1452 * mainly useful for testing, as the defaults should work with most users. | |
1453 * Those users who are tight on memory or want faster performance at the | |
1454 * expense of compression can modify them. See the compression library | |
1455 * header file (zlib.h) for an explination of the compression functions. | |
1456 */ | |
1457 | |
1458 /* Set the filtering method(s) used by libpng. Currently, the only valid | |
1459 * value for "method" is 0. | |
1460 */ | |
1461 PNG_EXPORT(67, void, png_set_filter, (png_structrp png_ptr, int method, | |
1462 int filters)); | |
1463 #endif /* WRITE */ | |
1464 | |
1465 /* Flags for png_set_filter() to say which filters to use. The flags | |
1466 * are chosen so that they don't conflict with real filter types | |
1467 * below, in case they are supplied instead of the #defined constants. | |
1468 * These values should NOT be changed. | |
1469 */ | |
1470 #define PNG_NO_FILTERS 0x00 | |
1471 #define PNG_FILTER_NONE 0x08 | |
1472 #define PNG_FILTER_SUB 0x10 | |
1473 #define PNG_FILTER_UP 0x20 | |
1474 #define PNG_FILTER_AVG 0x40 | |
1475 #define PNG_FILTER_PAETH 0x80 | |
1476 #define PNG_ALL_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP | \ | |
1477 PNG_FILTER_AVG | PNG_FILTER_PAETH) | |
1478 | |
1479 /* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now. | |
1480 * These defines should NOT be changed. | |
1481 */ | |
1482 #define PNG_FILTER_VALUE_NONE 0 | |
1483 #define PNG_FILTER_VALUE_SUB 1 | |
1484 #define PNG_FILTER_VALUE_UP 2 | |
1485 #define PNG_FILTER_VALUE_AVG 3 | |
1486 #define PNG_FILTER_VALUE_PAETH 4 | |
1487 #define PNG_FILTER_VALUE_LAST 5 | |
1488 | |
1489 #ifdef PNG_WRITE_SUPPORTED | |
1490 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* DEPRECATED */ | |
1491 PNG_FP_EXPORT(68, void, png_set_filter_heuristics, (png_structrp png_ptr, | |
1492 int heuristic_method, int num_weights, png_const_doublep filter_weights, | |
1493 png_const_doublep filter_costs)) | |
1494 PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed, | |
1495 (png_structrp png_ptr, int heuristic_method, int num_weights, | |
1496 png_const_fixed_point_p filter_weights, | |
1497 png_const_fixed_point_p filter_costs)) | |
1498 #endif /* WRITE_WEIGHTED_FILTER */ | |
1499 | |
1500 /* The following are no longer used and will be removed from libpng-1.7: */ | |
1501 #define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */ | |
1502 #define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */ | |
1503 #define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */ | |
1504 #define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */ | |
1505 | |
1506 /* Set the library compression level. Currently, valid values range from | |
1507 * 0 - 9, corresponding directly to the zlib compression levels 0 - 9 | |
1508 * (0 - no compression, 9 - "maximal" compression). Note that tests have | |
1509 * shown that zlib compression levels 3-6 usually perform as well as level 9 | |
1510 * for PNG images, and do considerably fewer caclulations. In the future, | |
1511 * these values may not correspond directly to the zlib compression levels. | |
1512 */ | |
1513 #ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED | |
1514 PNG_EXPORT(69, void, png_set_compression_level, (png_structrp png_ptr, | |
1515 int level)); | |
1516 | |
1517 PNG_EXPORT(70, void, png_set_compression_mem_level, (png_structrp png_ptr, | |
1518 int mem_level)); | |
1519 | |
1520 PNG_EXPORT(71, void, png_set_compression_strategy, (png_structrp png_ptr, | |
1521 int strategy)); | |
1522 | |
1523 /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a | |
1524 * smaller value of window_bits if it can do so safely. | |
1525 */ | |
1526 PNG_EXPORT(72, void, png_set_compression_window_bits, (png_structrp png_ptr, | |
1527 int window_bits)); | |
1528 | |
1529 PNG_EXPORT(73, void, png_set_compression_method, (png_structrp png_ptr, | |
1530 int method)); | |
1531 #endif /* WRITE_CUSTOMIZE_COMPRESSION */ | |
1532 | |
1533 #ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED | |
1534 /* Also set zlib parameters for compressing non-IDAT chunks */ | |
1535 PNG_EXPORT(222, void, png_set_text_compression_level, (png_structrp png_ptr, | |
1536 int level)); | |
1537 | |
1538 PNG_EXPORT(223, void, png_set_text_compression_mem_level, (png_structrp png_ptr, | |
1539 int mem_level)); | |
1540 | |
1541 PNG_EXPORT(224, void, png_set_text_compression_strategy, (png_structrp png_ptr, | |
1542 int strategy)); | |
1543 | |
1544 /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a | |
1545 * smaller value of window_bits if it can do so safely. | |
1546 */ | |
1547 PNG_EXPORT(225, void, png_set_text_compression_window_bits, | |
1548 (png_structrp png_ptr, int window_bits)); | |
1549 | |
1550 PNG_EXPORT(226, void, png_set_text_compression_method, (png_structrp png_ptr, | |
1551 int method)); | |
1552 #endif /* WRITE_CUSTOMIZE_ZTXT_COMPRESSION */ | |
1553 #endif /* WRITE */ | |
1554 | |
1555 /* These next functions are called for input/output, memory, and error | |
1556 * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c, | |
1557 * and call standard C I/O routines such as fread(), fwrite(), and | |
1558 * fprintf(). These functions can be made to use other I/O routines | |
1559 * at run time for those applications that need to handle I/O in a | |
1560 * different manner by calling png_set_???_fn(). See libpng-manual.txt for | |
1561 * more information. | |
1562 */ | |
1563 | |
1564 #ifdef PNG_STDIO_SUPPORTED | |
1565 /* Initialize the input/output for the PNG file to the default functions. */ | |
1566 PNG_EXPORT(74, void, png_init_io, (png_structrp png_ptr, png_FILE_p fp)); | |
1567 #endif | |
1568 | |
1569 /* Replace the (error and abort), and warning functions with user | |
1570 * supplied functions. If no messages are to be printed you must still | |
1571 * write and use replacement functions. The replacement error_fn should | |
1572 * still do a longjmp to the last setjmp location if you are using this | |
1573 * method of error handling. If error_fn or warning_fn is NULL, the | |
1574 * default function will be used. | |
1575 */ | |
1576 | |
1577 PNG_EXPORT(75, void, png_set_error_fn, (png_structrp png_ptr, | |
1578 png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn)); | |
1579 | |
1580 /* Return the user pointer associated with the error functions */ | |
1581 PNG_EXPORT(76, png_voidp, png_get_error_ptr, (png_const_structrp png_ptr)); | |
1582 | |
1583 /* Replace the default data output functions with a user supplied one(s). | |
1584 * If buffered output is not used, then output_flush_fn can be set to NULL. | |
1585 * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time | |
1586 * output_flush_fn will be ignored (and thus can be NULL). | |
1587 * It is probably a mistake to use NULL for output_flush_fn if | |
1588 * write_data_fn is not also NULL unless you have built libpng with | |
1589 * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's | |
1590 * default flush function, which uses the standard *FILE structure, will | |
1591 * be used. | |
1592 */ | |
1593 PNG_EXPORT(77, void, png_set_write_fn, (png_structrp png_ptr, png_voidp io_ptr, | |
1594 png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn)); | |
1595 | |
1596 /* Replace the default data input function with a user supplied one. */ | |
1597 PNG_EXPORT(78, void, png_set_read_fn, (png_structrp png_ptr, png_voidp io_ptr, | |
1598 png_rw_ptr read_data_fn)); | |
1599 | |
1600 /* Return the user pointer associated with the I/O functions */ | |
1601 PNG_EXPORT(79, png_voidp, png_get_io_ptr, (png_const_structrp png_ptr)); | |
1602 | |
1603 PNG_EXPORT(80, void, png_set_read_status_fn, (png_structrp png_ptr, | |
1604 png_read_status_ptr read_row_fn)); | |
1605 | |
1606 PNG_EXPORT(81, void, png_set_write_status_fn, (png_structrp png_ptr, | |
1607 png_write_status_ptr write_row_fn)); | |
1608 | |
1609 #ifdef PNG_USER_MEM_SUPPORTED | |
1610 /* Replace the default memory allocation functions with user supplied one(s). */ | |
1611 PNG_EXPORT(82, void, png_set_mem_fn, (png_structrp png_ptr, png_voidp mem_ptr, | |
1612 png_malloc_ptr malloc_fn, png_free_ptr free_fn)); | |
1613 /* Return the user pointer associated with the memory functions */ | |
1614 PNG_EXPORT(83, png_voidp, png_get_mem_ptr, (png_const_structrp png_ptr)); | |
1615 #endif | |
1616 | |
1617 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED | |
1618 PNG_EXPORT(84, void, png_set_read_user_transform_fn, (png_structrp png_ptr, | |
1619 png_user_transform_ptr read_user_transform_fn)); | |
1620 #endif | |
1621 | |
1622 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED | |
1623 PNG_EXPORT(85, void, png_set_write_user_transform_fn, (png_structrp png_ptr, | |
1624 png_user_transform_ptr write_user_transform_fn)); | |
1625 #endif | |
1626 | |
1627 #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED | |
1628 PNG_EXPORT(86, void, png_set_user_transform_info, (png_structrp png_ptr, | |
1629 png_voidp user_transform_ptr, int user_transform_depth, | |
1630 int user_transform_channels)); | |
1631 /* Return the user pointer associated with the user transform functions */ | |
1632 PNG_EXPORT(87, png_voidp, png_get_user_transform_ptr, | |
1633 (png_const_structrp png_ptr)); | |
1634 #endif | |
1635 | |
1636 #ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED | |
1637 /* Return information about the row currently being processed. Note that these | |
1638 * APIs do not fail but will return unexpected results if called outside a user | |
1639 * transform callback. Also note that when transforming an interlaced image the | |
1640 * row number is the row number within the sub-image of the interlace pass, so | |
1641 * the value will increase to the height of the sub-image (not the full image) | |
1642 * then reset to 0 for the next pass. | |
1643 * | |
1644 * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to | |
1645 * find the output pixel (x,y) given an interlaced sub-image pixel | |
1646 * (row,col,pass). (See below for these macros.) | |
1647 */ | |
1648 PNG_EXPORT(217, png_uint_32, png_get_current_row_number, (png_const_structrp)); | |
1649 PNG_EXPORT(218, png_byte, png_get_current_pass_number, (png_const_structrp)); | |
1650 #endif | |
1651 | |
1652 #ifdef PNG_READ_USER_CHUNKS_SUPPORTED | |
1653 /* This callback is called only for *unknown* chunks. If | |
1654 * PNG_HANDLE_AS_UNKNOWN_SUPPORTED is set then it is possible to set known | |
1655 * chunks to be treated as unknown, however in this case the callback must do | |
1656 * any processing required by the chunk (e.g. by calling the appropriate | |
1657 * png_set_ APIs.) | |
1658 * | |
1659 * There is no write support - on write, by default, all the chunks in the | |
1660 * 'unknown' list are written in the specified position. | |
1661 * | |
1662 * The integer return from the callback function is interpreted thus: | |
1663 * | |
1664 * negative: An error occurred; png_chunk_error will be called. | |
1665 * zero: The chunk was not handled, the chunk will be saved. A critical | |
1666 * chunk will cause an error at this point unless it is to be saved. | |
1667 * positive: The chunk was handled, libpng will ignore/discard it. | |
1668 * | |
1669 * See "INTERACTION WTIH USER CHUNK CALLBACKS" below for important notes about | |
1670 * how this behavior will change in libpng 1.7 | |
1671 */ | |
1672 PNG_EXPORT(88, void, png_set_read_user_chunk_fn, (png_structrp png_ptr, | |
1673 png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn)); | |
1674 #endif | |
1675 | |
1676 #ifdef PNG_USER_CHUNKS_SUPPORTED | |
1677 PNG_EXPORT(89, png_voidp, png_get_user_chunk_ptr, (png_const_structrp png_ptr)); | |
1678 #endif | |
1679 | |
1680 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED | |
1681 /* Sets the function callbacks for the push reader, and a pointer to a | |
1682 * user-defined structure available to the callback functions. | |
1683 */ | |
1684 PNG_EXPORT(90, void, png_set_progressive_read_fn, (png_structrp png_ptr, | |
1685 png_voidp progressive_ptr, png_progressive_info_ptr info_fn, | |
1686 png_progressive_row_ptr row_fn, png_progressive_end_ptr end_fn)); | |
1687 | |
1688 /* Returns the user pointer associated with the push read functions */ | |
1689 PNG_EXPORT(91, png_voidp, png_get_progressive_ptr, | |
1690 (png_const_structrp png_ptr)); | |
1691 | |
1692 /* Function to be called when data becomes available */ | |
1693 PNG_EXPORT(92, void, png_process_data, (png_structrp png_ptr, | |
1694 png_inforp info_ptr, png_bytep buffer, png_size_t buffer_size)); | |
1695 | |
1696 /* A function which may be called *only* within png_process_data to stop the | |
1697 * processing of any more data. The function returns the number of bytes | |
1698 * remaining, excluding any that libpng has cached internally. A subsequent | |
1699 * call to png_process_data must supply these bytes again. If the argument | |
1700 * 'save' is set to true the routine will first save all the pending data and | |
1701 * will always return 0. | |
1702 */ | |
1703 PNG_EXPORT(219, png_size_t, png_process_data_pause, (png_structrp, int save)); | |
1704 | |
1705 /* A function which may be called *only* outside (after) a call to | |
1706 * png_process_data. It returns the number of bytes of data to skip in the | |
1707 * input. Normally it will return 0, but if it returns a non-zero value the | |
1708 * application must skip than number of bytes of input data and pass the | |
1709 * following data to the next call to png_process_data. | |
1710 */ | |
1711 PNG_EXPORT(220, png_uint_32, png_process_data_skip, (png_structrp)); | |
1712 | |
1713 /* Function that combines rows. 'new_row' is a flag that should come from | |
1714 * the callback and be non-NULL if anything needs to be done; the library | |
1715 * stores its own version of the new data internally and ignores the passed | |
1716 * in value. | |
1717 */ | |
1718 PNG_EXPORT(93, void, png_progressive_combine_row, (png_const_structrp png_ptr, | |
1719 png_bytep old_row, png_const_bytep new_row)); | |
1720 #endif /* PROGRESSIVE_READ */ | |
1721 | |
1722 PNG_EXPORTA(94, png_voidp, png_malloc, (png_const_structrp png_ptr, | |
1723 png_alloc_size_t size), PNG_ALLOCATED); | |
1724 /* Added at libpng version 1.4.0 */ | |
1725 PNG_EXPORTA(95, png_voidp, png_calloc, (png_const_structrp png_ptr, | |
1726 png_alloc_size_t size), PNG_ALLOCATED); | |
1727 | |
1728 /* Added at libpng version 1.2.4 */ | |
1729 PNG_EXPORTA(96, png_voidp, png_malloc_warn, (png_const_structrp png_ptr, | |
1730 png_alloc_size_t size), PNG_ALLOCATED); | |
1731 | |
1732 /* Frees a pointer allocated by png_malloc() */ | |
1733 PNG_EXPORT(97, void, png_free, (png_const_structrp png_ptr, png_voidp ptr)); | |
1734 | |
1735 /* Free data that was allocated internally */ | |
1736 PNG_EXPORT(98, void, png_free_data, (png_const_structrp png_ptr, | |
1737 png_inforp info_ptr, png_uint_32 free_me, int num)); | |
1738 | |
1739 /* Reassign responsibility for freeing existing data, whether allocated | |
1740 * by libpng or by the application; this works on the png_info structure passed | |
1741 * in, it does not change the state for other png_info structures. | |
1742 * | |
1743 * It is unlikely that this function works correctly as of 1.6.0 and using it | |
1744 * may result either in memory leaks or double free of allocated data. | |
1745 */ | |
1746 PNG_EXPORT(99, void, png_data_freer, (png_const_structrp png_ptr, | |
1747 png_inforp info_ptr, int freer, png_uint_32 mask)); | |
1748 | |
1749 /* Assignments for png_data_freer */ | |
1750 #define PNG_DESTROY_WILL_FREE_DATA 1 | |
1751 #define PNG_SET_WILL_FREE_DATA 1 | |
1752 #define PNG_USER_WILL_FREE_DATA 2 | |
1753 /* Flags for png_ptr->free_me and info_ptr->free_me */ | |
1754 #define PNG_FREE_HIST 0x0008 | |
1755 #define PNG_FREE_ICCP 0x0010 | |
1756 #define PNG_FREE_SPLT 0x0020 | |
1757 #define PNG_FREE_ROWS 0x0040 | |
1758 #define PNG_FREE_PCAL 0x0080 | |
1759 #define PNG_FREE_SCAL 0x0100 | |
1760 #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED | |
1761 # define PNG_FREE_UNKN 0x0200 | |
1762 #endif | |
1763 /* PNG_FREE_LIST 0x0400 removed in 1.6.0 because it is ignored */ | |
1764 #define PNG_FREE_PLTE 0x1000 | |
1765 #define PNG_FREE_TRNS 0x2000 | |
1766 #define PNG_FREE_TEXT 0x4000 | |
1767 #define PNG_FREE_ALL 0x7fff | |
1768 #define PNG_FREE_MUL 0x4220 /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */ | |
1769 | |
1770 #ifdef PNG_USER_MEM_SUPPORTED | |
1771 PNG_EXPORTA(100, png_voidp, png_malloc_default, (png_const_structrp png_ptr, | |
1772 png_alloc_size_t size), PNG_ALLOCATED PNG_DEPRECATED); | |
1773 PNG_EXPORTA(101, void, png_free_default, (png_const_structrp png_ptr, | |
1774 png_voidp ptr), PNG_DEPRECATED); | |
1775 #endif | |
1776 | |
1777 #ifdef PNG_ERROR_TEXT_SUPPORTED | |
1778 /* Fatal error in PNG image of libpng - can't continue */ | |
1779 PNG_EXPORTA(102, void, png_error, (png_const_structrp png_ptr, | |
1780 png_const_charp error_message), PNG_NORETURN); | |
1781 | |
1782 /* The same, but the chunk name is prepended to the error string. */ | |
1783 PNG_EXPORTA(103, void, png_chunk_error, (png_const_structrp png_ptr, | |
1784 png_const_charp error_message), PNG_NORETURN); | |
1785 | |
1786 #else | |
1787 /* Fatal error in PNG image of libpng - can't continue */ | |
1788 PNG_EXPORTA(104, void, png_err, (png_const_structrp png_ptr), PNG_NORETURN); | |
1789 # define png_error(s1,s2) png_err(s1) | |
1790 # define png_chunk_error(s1,s2) png_err(s1) | |
1791 #endif | |
1792 | |
1793 #ifdef PNG_WARNINGS_SUPPORTED | |
1794 /* Non-fatal error in libpng. Can continue, but may have a problem. */ | |
1795 PNG_EXPORT(105, void, png_warning, (png_const_structrp png_ptr, | |
1796 png_const_charp warning_message)); | |
1797 | |
1798 /* Non-fatal error in libpng, chunk name is prepended to message. */ | |
1799 PNG_EXPORT(106, void, png_chunk_warning, (png_const_structrp png_ptr, | |
1800 png_const_charp warning_message)); | |
1801 #else | |
1802 # define png_warning(s1,s2) ((void)(s1)) | |
1803 # define png_chunk_warning(s1,s2) ((void)(s1)) | |
1804 #endif | |
1805 | |
1806 #ifdef PNG_BENIGN_ERRORS_SUPPORTED | |
1807 /* Benign error in libpng. Can continue, but may have a problem. | |
1808 * User can choose whether to handle as a fatal error or as a warning. */ | |
1809 PNG_EXPORT(107, void, png_benign_error, (png_const_structrp png_ptr, | |
1810 png_const_charp warning_message)); | |
1811 | |
1812 #ifdef PNG_READ_SUPPORTED | |
1813 /* Same, chunk name is prepended to message (only during read) */ | |
1814 PNG_EXPORT(108, void, png_chunk_benign_error, (png_const_structrp png_ptr, | |
1815 png_const_charp warning_message)); | |
1816 #endif | |
1817 | |
1818 PNG_EXPORT(109, void, png_set_benign_errors, | |
1819 (png_structrp png_ptr, int allowed)); | |
1820 #else | |
1821 # ifdef PNG_ALLOW_BENIGN_ERRORS | |
1822 # define png_benign_error png_warning | |
1823 # define png_chunk_benign_error png_chunk_warning | |
1824 # else | |
1825 # define png_benign_error png_error | |
1826 # define png_chunk_benign_error png_chunk_error | |
1827 # endif | |
1828 #endif | |
1829 | |
1830 /* The png_set_<chunk> functions are for storing values in the png_info_struct. | |
1831 * Similarly, the png_get_<chunk> calls are used to read values from the | |
1832 * png_info_struct, either storing the parameters in the passed variables, or | |
1833 * setting pointers into the png_info_struct where the data is stored. The | |
1834 * png_get_<chunk> functions return a non-zero value if the data was available | |
1835 * in info_ptr, or return zero and do not change any of the parameters if the | |
1836 * data was not available. | |
1837 * | |
1838 * These functions should be used instead of directly accessing png_info | |
1839 * to avoid problems with future changes in the size and internal layout of | |
1840 * png_info_struct. | |
1841 */ | |
1842 /* Returns "flag" if chunk data is valid in info_ptr. */ | |
1843 PNG_EXPORT(110, png_uint_32, png_get_valid, (png_const_structrp png_ptr, | |
1844 png_const_inforp info_ptr, png_uint_32 flag)); | |
1845 | |
1846 /* Returns number of bytes needed to hold a transformed row. */ | |
1847 PNG_EXPORT(111, png_size_t, png_get_rowbytes, (png_const_structrp png_ptr, | |
1848 png_const_inforp info_ptr)); | |
1849 | |
1850 #ifdef PNG_INFO_IMAGE_SUPPORTED | |
1851 /* Returns row_pointers, which is an array of pointers to scanlines that was | |
1852 * returned from png_read_png(). | |
1853 */ | |
1854 PNG_EXPORT(112, png_bytepp, png_get_rows, (png_const_structrp png_ptr, | |
1855 png_const_inforp info_ptr)); | |
1856 | |
1857 /* Set row_pointers, which is an array of pointers to scanlines for use | |
1858 * by png_write_png(). | |
1859 */ | |
1860 PNG_EXPORT(113, void, png_set_rows, (png_const_structrp png_ptr, | |
1861 png_inforp info_ptr, png_bytepp row_pointers)); | |
1862 #endif | |
1863 | |
1864 /* Returns number of color channels in image. */ | |
1865 PNG_EXPORT(114, png_byte, png_get_channels, (png_const_structrp png_ptr, | |
1866 png_const_inforp info_ptr)); | |
1867 | |
1868 #ifdef PNG_EASY_ACCESS_SUPPORTED | |
1869 /* Returns image width in pixels. */ | |
1870 PNG_EXPORT(115, png_uint_32, png_get_image_width, (png_const_structrp png_ptr, | |
1871 png_const_inforp info_ptr)); | |
1872 | |
1873 /* Returns image height in pixels. */ | |
1874 PNG_EXPORT(116, png_uint_32, png_get_image_height, (png_const_structrp png_ptr, | |
1875 png_const_inforp info_ptr)); | |
1876 | |
1877 /* Returns image bit_depth. */ | |
1878 PNG_EXPORT(117, png_byte, png_get_bit_depth, (png_const_structrp png_ptr, | |
1879 png_const_inforp info_ptr)); | |
1880 | |
1881 /* Returns image color_type. */ | |
1882 PNG_EXPORT(118, png_byte, png_get_color_type, (png_const_structrp png_ptr, | |
1883 png_const_inforp info_ptr)); | |
1884 | |
1885 /* Returns image filter_type. */ | |
1886 PNG_EXPORT(119, png_byte, png_get_filter_type, (png_const_structrp png_ptr, | |
1887 png_const_inforp info_ptr)); | |
1888 | |
1889 /* Returns image interlace_type. */ | |
1890 PNG_EXPORT(120, png_byte, png_get_interlace_type, (png_const_structrp png_ptr, | |
1891 png_const_inforp info_ptr)); | |
1892 | |
1893 /* Returns image compression_type. */ | |
1894 PNG_EXPORT(121, png_byte, png_get_compression_type, (png_const_structrp png_ptr, | |
1895 png_const_inforp info_ptr)); | |
1896 | |
1897 /* Returns image resolution in pixels per meter, from pHYs chunk data. */ | |
1898 PNG_EXPORT(122, png_uint_32, png_get_pixels_per_meter, | |
1899 (png_const_structrp png_ptr, png_const_inforp info_ptr)); | |
1900 PNG_EXPORT(123, png_uint_32, png_get_x_pixels_per_meter, | |
1901 (png_const_structrp png_ptr, png_const_inforp info_ptr)); | |
1902 PNG_EXPORT(124, png_uint_32, png_get_y_pixels_per_meter, | |
1903 (png_const_structrp png_ptr, png_const_inforp info_ptr)); | |
1904 | |
1905 /* Returns pixel aspect ratio, computed from pHYs chunk data. */ | |
1906 PNG_FP_EXPORT(125, float, png_get_pixel_aspect_ratio, | |
1907 (png_const_structrp png_ptr, png_const_inforp info_ptr)) | |
1908 PNG_FIXED_EXPORT(210, png_fixed_point, png_get_pixel_aspect_ratio_fixed, | |
1909 (png_const_structrp png_ptr, png_const_inforp info_ptr)) | |
1910 | |
1911 /* Returns image x, y offset in pixels or microns, from oFFs chunk data. */ | |
1912 PNG_EXPORT(126, png_int_32, png_get_x_offset_pixels, | |
1913 (png_const_structrp png_ptr, png_const_inforp info_ptr)); | |
1914 PNG_EXPORT(127, png_int_32, png_get_y_offset_pixels, | |
1915 (png_const_structrp png_ptr, png_const_inforp info_ptr)); | |
1916 PNG_EXPORT(128, png_int_32, png_get_x_offset_microns, | |
1917 (png_const_structrp png_ptr, png_const_inforp info_ptr)); | |
1918 PNG_EXPORT(129, png_int_32, png_get_y_offset_microns, | |
1919 (png_const_structrp png_ptr, png_const_inforp info_ptr)); | |
1920 | |
1921 #endif /* EASY_ACCESS */ | |
1922 | |
1923 #ifdef PNG_READ_SUPPORTED | |
1924 /* Returns pointer to signature string read from PNG header */ | |
1925 PNG_EXPORT(130, png_const_bytep, png_get_signature, (png_const_structrp png_ptr, | |
1926 png_const_inforp info_ptr)); | |
1927 #endif | |
1928 | |
1929 #ifdef PNG_bKGD_SUPPORTED | |
1930 PNG_EXPORT(131, png_uint_32, png_get_bKGD, (png_const_structrp png_ptr, | |
1931 png_inforp info_ptr, png_color_16p *background)); | |
1932 #endif | |
1933 | |
1934 #ifdef PNG_bKGD_SUPPORTED | |
1935 PNG_EXPORT(132, void, png_set_bKGD, (png_const_structrp png_ptr, | |
1936 png_inforp info_ptr, png_const_color_16p background)); | |
1937 #endif | |
1938 | |
1939 #ifdef PNG_cHRM_SUPPORTED | |
1940 PNG_FP_EXPORT(133, png_uint_32, png_get_cHRM, (png_const_structrp png_ptr, | |
1941 png_const_inforp info_ptr, double *white_x, double *white_y, double *red_x, | |
1942 double *red_y, double *green_x, double *green_y, double *blue_x, | |
1943 double *blue_y)) | |
1944 PNG_FP_EXPORT(230, png_uint_32, png_get_cHRM_XYZ, (png_const_structrp png_ptr, | |
1945 png_const_inforp info_ptr, double *red_X, double *red_Y, double *red_Z, | |
1946 double *green_X, double *green_Y, double *green_Z, double *blue_X, | |
1947 double *blue_Y, double *blue_Z)) | |
1948 PNG_FIXED_EXPORT(134, png_uint_32, png_get_cHRM_fixed, | |
1949 (png_const_structrp png_ptr, png_const_inforp info_ptr, | |
1950 png_fixed_point *int_white_x, png_fixed_point *int_white_y, | |
1951 png_fixed_point *int_red_x, png_fixed_point *int_red_y, | |
1952 png_fixed_point *int_green_x, png_fixed_point *int_green_y, | |
1953 png_fixed_point *int_blue_x, png_fixed_point *int_blue_y)) | |
1954 PNG_FIXED_EXPORT(231, png_uint_32, png_get_cHRM_XYZ_fixed, | |
1955 (png_const_structrp png_ptr, png_const_inforp info_ptr, | |
1956 png_fixed_point *int_red_X, png_fixed_point *int_red_Y, | |
1957 png_fixed_point *int_red_Z, png_fixed_point *int_green_X, | |
1958 png_fixed_point *int_green_Y, png_fixed_point *int_green_Z, | |
1959 png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y, | |
1960 png_fixed_point *int_blue_Z)) | |
1961 #endif | |
1962 | |
1963 #ifdef PNG_cHRM_SUPPORTED | |
1964 PNG_FP_EXPORT(135, void, png_set_cHRM, (png_const_structrp png_ptr, | |
1965 png_inforp info_ptr, | |
1966 double white_x, double white_y, double red_x, double red_y, double green_x, | |
1967 double green_y, double blue_x, double blue_y)) | |
1968 PNG_FP_EXPORT(232, void, png_set_cHRM_XYZ, (png_const_structrp png_ptr, | |
1969 png_inforp info_ptr, double red_X, double red_Y, double red_Z, | |
1970 double green_X, double green_Y, double green_Z, double blue_X, | |
1971 double blue_Y, double blue_Z)) | |
1972 PNG_FIXED_EXPORT(136, void, png_set_cHRM_fixed, (png_const_structrp png_ptr, | |
1973 png_inforp info_ptr, png_fixed_point int_white_x, | |
1974 png_fixed_point int_white_y, png_fixed_point int_red_x, | |
1975 png_fixed_point int_red_y, png_fixed_point int_green_x, | |
1976 png_fixed_point int_green_y, png_fixed_point int_blue_x, | |
1977 png_fixed_point int_blue_y)) | |
1978 PNG_FIXED_EXPORT(233, void, png_set_cHRM_XYZ_fixed, (png_const_structrp png_ptr, | |
1979 png_inforp info_ptr, png_fixed_point int_red_X, png_fixed_point int_red_Y, | |
1980 png_fixed_point int_red_Z, png_fixed_point int_green_X, | |
1981 png_fixed_point int_green_Y, png_fixed_point int_green_Z, | |
1982 png_fixed_point int_blue_X, png_fixed_point int_blue_Y, | |
1983 png_fixed_point int_blue_Z)) | |
1984 #endif | |
1985 | |
1986 #ifdef PNG_gAMA_SUPPORTED | |
1987 PNG_FP_EXPORT(137, png_uint_32, png_get_gAMA, (png_const_structrp png_ptr, | |
1988 png_const_inforp info_ptr, double *file_gamma)) | |
1989 PNG_FIXED_EXPORT(138, png_uint_32, png_get_gAMA_fixed, | |
1990 (png_const_structrp png_ptr, png_const_inforp info_ptr, | |
1991 png_fixed_point *int_file_gamma)) | |
1992 #endif | |
1993 | |
1994 #ifdef PNG_gAMA_SUPPORTED | |
1995 PNG_FP_EXPORT(139, void, png_set_gAMA, (png_const_structrp png_ptr, | |
1996 png_inforp info_ptr, double file_gamma)) | |
1997 PNG_FIXED_EXPORT(140, void, png_set_gAMA_fixed, (png_const_structrp png_ptr, | |
1998 png_inforp info_ptr, png_fixed_point int_file_gamma)) | |
1999 #endif | |
2000 | |
2001 #ifdef PNG_hIST_SUPPORTED | |
2002 PNG_EXPORT(141, png_uint_32, png_get_hIST, (png_const_structrp png_ptr, | |
2003 png_inforp info_ptr, png_uint_16p *hist)); | |
2004 #endif | |
2005 | |
2006 #ifdef PNG_hIST_SUPPORTED | |
2007 PNG_EXPORT(142, void, png_set_hIST, (png_const_structrp png_ptr, | |
2008 png_inforp info_ptr, png_const_uint_16p hist)); | |
2009 #endif | |
2010 | |
2011 PNG_EXPORT(143, png_uint_32, png_get_IHDR, (png_const_structrp png_ptr, | |
2012 png_const_inforp info_ptr, png_uint_32 *width, png_uint_32 *height, | |
2013 int *bit_depth, int *color_type, int *interlace_method, | |
2014 int *compression_method, int *filter_method)); | |
2015 | |
2016 PNG_EXPORT(144, void, png_set_IHDR, (png_const_structrp png_ptr, | |
2017 png_inforp info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth, | |
2018 int color_type, int interlace_method, int compression_method, | |
2019 int filter_method)); | |
2020 | |
2021 #ifdef PNG_oFFs_SUPPORTED | |
2022 PNG_EXPORT(145, png_uint_32, png_get_oFFs, (png_const_structrp png_ptr, | |
2023 png_const_inforp info_ptr, png_int_32 *offset_x, png_int_32 *offset_y, | |
2024 int *unit_type)); | |
2025 #endif | |
2026 | |
2027 #ifdef PNG_oFFs_SUPPORTED | |
2028 PNG_EXPORT(146, void, png_set_oFFs, (png_const_structrp png_ptr, | |
2029 png_inforp info_ptr, png_int_32 offset_x, png_int_32 offset_y, | |
2030 int unit_type)); | |
2031 #endif | |
2032 | |
2033 #ifdef PNG_pCAL_SUPPORTED | |
2034 PNG_EXPORT(147, png_uint_32, png_get_pCAL, (png_const_structrp png_ptr, | |
2035 png_inforp info_ptr, png_charp *purpose, png_int_32 *X0, | |
2036 png_int_32 *X1, int *type, int *nparams, png_charp *units, | |
2037 png_charpp *params)); | |
2038 #endif | |
2039 | |
2040 #ifdef PNG_pCAL_SUPPORTED | |
2041 PNG_EXPORT(148, void, png_set_pCAL, (png_const_structrp png_ptr, | |
2042 png_inforp info_ptr, png_const_charp purpose, png_int_32 X0, png_int_32 X1, | |
2043 int type, int nparams, png_const_charp units, png_charpp params)); | |
2044 #endif | |
2045 | |
2046 #ifdef PNG_pHYs_SUPPORTED | |
2047 PNG_EXPORT(149, png_uint_32, png_get_pHYs, (png_const_structrp png_ptr, | |
2048 png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, | |
2049 int *unit_type)); | |
2050 #endif | |
2051 | |
2052 #ifdef PNG_pHYs_SUPPORTED | |
2053 PNG_EXPORT(150, void, png_set_pHYs, (png_const_structrp png_ptr, | |
2054 png_inforp info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type)); | |
2055 #endif | |
2056 | |
2057 PNG_EXPORT(151, png_uint_32, png_get_PLTE, (png_const_structrp png_ptr, | |
2058 png_inforp info_ptr, png_colorp *palette, int *num_palette)); | |
2059 | |
2060 PNG_EXPORT(152, void, png_set_PLTE, (png_structrp png_ptr, | |
2061 png_inforp info_ptr, png_const_colorp palette, int num_palette)); | |
2062 | |
2063 #ifdef PNG_sBIT_SUPPORTED | |
2064 PNG_EXPORT(153, png_uint_32, png_get_sBIT, (png_const_structrp png_ptr, | |
2065 png_inforp info_ptr, png_color_8p *sig_bit)); | |
2066 #endif | |
2067 | |
2068 #ifdef PNG_sBIT_SUPPORTED | |
2069 PNG_EXPORT(154, void, png_set_sBIT, (png_const_structrp png_ptr, | |
2070 png_inforp info_ptr, png_const_color_8p sig_bit)); | |
2071 #endif | |
2072 | |
2073 #ifdef PNG_sRGB_SUPPORTED | |
2074 PNG_EXPORT(155, png_uint_32, png_get_sRGB, (png_const_structrp png_ptr, | |
2075 png_const_inforp info_ptr, int *file_srgb_intent)); | |
2076 #endif | |
2077 | |
2078 #ifdef PNG_sRGB_SUPPORTED | |
2079 PNG_EXPORT(156, void, png_set_sRGB, (png_const_structrp png_ptr, | |
2080 png_inforp info_ptr, int srgb_intent)); | |
2081 PNG_EXPORT(157, void, png_set_sRGB_gAMA_and_cHRM, (png_const_structrp png_ptr, | |
2082 png_inforp info_ptr, int srgb_intent)); | |
2083 #endif | |
2084 | |
2085 #ifdef PNG_iCCP_SUPPORTED | |
2086 PNG_EXPORT(158, png_uint_32, png_get_iCCP, (png_const_structrp png_ptr, | |
2087 png_inforp info_ptr, png_charpp name, int *compression_type, | |
2088 png_bytepp profile, png_uint_32 *proflen)); | |
2089 #endif | |
2090 | |
2091 #ifdef PNG_iCCP_SUPPORTED | |
2092 PNG_EXPORT(159, void, png_set_iCCP, (png_const_structrp png_ptr, | |
2093 png_inforp info_ptr, png_const_charp name, int compression_type, | |
2094 png_const_bytep profile, png_uint_32 proflen)); | |
2095 #endif | |
2096 | |
2097 #ifdef PNG_sPLT_SUPPORTED | |
2098 PNG_EXPORT(160, int, png_get_sPLT, (png_const_structrp png_ptr, | |
2099 png_inforp info_ptr, png_sPLT_tpp entries)); | |
2100 #endif | |
2101 | |
2102 #ifdef PNG_sPLT_SUPPORTED | |
2103 PNG_EXPORT(161, void, png_set_sPLT, (png_const_structrp png_ptr, | |
2104 png_inforp info_ptr, png_const_sPLT_tp entries, int nentries)); | |
2105 #endif | |
2106 | |
2107 #ifdef PNG_TEXT_SUPPORTED | |
2108 /* png_get_text also returns the number of text chunks in *num_text */ | |
2109 PNG_EXPORT(162, int, png_get_text, (png_const_structrp png_ptr, | |
2110 png_inforp info_ptr, png_textp *text_ptr, int *num_text)); | |
2111 #endif | |
2112 | |
2113 /* Note while png_set_text() will accept a structure whose text, | |
2114 * language, and translated keywords are NULL pointers, the structure | |
2115 * returned by png_get_text will always contain regular | |
2116 * zero-terminated C strings. They might be empty strings but | |
2117 * they will never be NULL pointers. | |
2118 */ | |
2119 | |
2120 #ifdef PNG_TEXT_SUPPORTED | |
2121 PNG_EXPORT(163, void, png_set_text, (png_const_structrp png_ptr, | |
2122 png_inforp info_ptr, png_const_textp text_ptr, int num_text)); | |
2123 #endif | |
2124 | |
2125 #ifdef PNG_tIME_SUPPORTED | |
2126 PNG_EXPORT(164, png_uint_32, png_get_tIME, (png_const_structrp png_ptr, | |
2127 png_inforp info_ptr, png_timep *mod_time)); | |
2128 #endif | |
2129 | |
2130 #ifdef PNG_tIME_SUPPORTED | |
2131 PNG_EXPORT(165, void, png_set_tIME, (png_const_structrp png_ptr, | |
2132 png_inforp info_ptr, png_const_timep mod_time)); | |
2133 #endif | |
2134 | |
2135 #ifdef PNG_tRNS_SUPPORTED | |
2136 PNG_EXPORT(166, png_uint_32, png_get_tRNS, (png_const_structrp png_ptr, | |
2137 png_inforp info_ptr, png_bytep *trans_alpha, int *num_trans, | |
2138 png_color_16p *trans_color)); | |
2139 #endif | |
2140 | |
2141 #ifdef PNG_tRNS_SUPPORTED | |
2142 PNG_EXPORT(167, void, png_set_tRNS, (png_structrp png_ptr, | |
2143 png_inforp info_ptr, png_const_bytep trans_alpha, int num_trans, | |
2144 png_const_color_16p trans_color)); | |
2145 #endif | |
2146 | |
2147 #ifdef PNG_sCAL_SUPPORTED | |
2148 PNG_FP_EXPORT(168, png_uint_32, png_get_sCAL, (png_const_structrp png_ptr, | |
2149 png_const_inforp info_ptr, int *unit, double *width, double *height)) | |
2150 #if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || \ | |
2151 defined(PNG_FLOATING_POINT_SUPPORTED) | |
2152 /* NOTE: this API is currently implemented using floating point arithmetic, | |
2153 * consequently it can only be used on systems with floating point support. | |
2154 * In any case the range of values supported by png_fixed_point is small and it | |
2155 * is highly recommended that png_get_sCAL_s be used instead. | |
2156 */ | |
2157 PNG_FIXED_EXPORT(214, png_uint_32, png_get_sCAL_fixed, | |
2158 (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit, | |
2159 png_fixed_point *width, png_fixed_point *height)) | |
2160 #endif | |
2161 PNG_EXPORT(169, png_uint_32, png_get_sCAL_s, | |
2162 (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit, | |
2163 png_charpp swidth, png_charpp sheight)); | |
2164 | |
2165 PNG_FP_EXPORT(170, void, png_set_sCAL, (png_const_structrp png_ptr, | |
2166 png_inforp info_ptr, int unit, double width, double height)) | |
2167 PNG_FIXED_EXPORT(213, void, png_set_sCAL_fixed, (png_const_structrp png_ptr, | |
2168 png_inforp info_ptr, int unit, png_fixed_point width, | |
2169 png_fixed_point height)) | |
2170 PNG_EXPORT(171, void, png_set_sCAL_s, (png_const_structrp png_ptr, | |
2171 png_inforp info_ptr, int unit, | |
2172 png_const_charp swidth, png_const_charp sheight)); | |
2173 #endif /* sCAL */ | |
2174 | |
2175 #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED | |
2176 /* Provide the default handling for all unknown chunks or, optionally, for | |
2177 * specific unknown chunks. | |
2178 * | |
2179 * NOTE: prior to 1.6.0 the handling specified for particular chunks on read was | |
2180 * ignored and the default was used, the per-chunk setting only had an effect on | |
2181 * write. If you wish to have chunk-specific handling on read in code that must | |
2182 * work on earlier versions you must use a user chunk callback to specify the | |
2183 * desired handling (keep or discard.) | |
2184 * | |
2185 * The 'keep' parameter is a PNG_HANDLE_CHUNK_ value as listed below. The | |
2186 * parameter is interpreted as follows: | |
2187 * | |
2188 * READ: | |
2189 * PNG_HANDLE_CHUNK_AS_DEFAULT: | |
2190 * Known chunks: do normal libpng processing, do not keep the chunk (but | |
2191 * see the comments below about PNG_HANDLE_AS_UNKNOWN_SUPPORTED) | |
2192 * Unknown chunks: for a specific chunk use the global default, when used | |
2193 * as the default discard the chunk data. | |
2194 * PNG_HANDLE_CHUNK_NEVER: | |
2195 * Discard the chunk data. | |
2196 * PNG_HANDLE_CHUNK_IF_SAFE: | |
2197 * Keep the chunk data if the chunk is not critical else raise a chunk | |
2198 * error. | |
2199 * PNG_HANDLE_CHUNK_ALWAYS: | |
2200 * Keep the chunk data. | |
2201 * | |
2202 * If the chunk data is saved it can be retrieved using png_get_unknown_chunks, | |
2203 * below. Notice that specifying "AS_DEFAULT" as a global default is equivalent | |
2204 * to specifying "NEVER", however when "AS_DEFAULT" is used for specific chunks | |
2205 * it simply resets the behavior to the libpng default. | |
2206 * | |
2207 * INTERACTION WTIH USER CHUNK CALLBACKS: | |
2208 * The per-chunk handling is always used when there is a png_user_chunk_ptr | |
2209 * callback and the callback returns 0; the chunk is then always stored *unless* | |
2210 * it is critical and the per-chunk setting is other than ALWAYS. Notice that | |
2211 * the global default is *not* used in this case. (In effect the per-chunk | |
2212 * value is incremented to at least IF_SAFE.) | |
2213 * | |
2214 * IMPORTANT NOTE: this behavior will change in libpng 1.7 - the global and | |
2215 * per-chunk defaults will be honored. If you want to preserve the current | |
2216 * behavior when your callback returns 0 you must set PNG_HANDLE_CHUNK_IF_SAFE | |
2217 * as the default - if you don't do this libpng 1.6 will issue a warning. | |
2218 * | |
2219 * If you want unhandled unknown chunks to be discarded in libpng 1.6 and | |
2220 * earlier simply return '1' (handled). | |
2221 * | |
2222 * PNG_HANDLE_AS_UNKNOWN_SUPPORTED: | |
2223 * If this is *not* set known chunks will always be handled by libpng and | |
2224 * will never be stored in the unknown chunk list. Known chunks listed to | |
2225 * png_set_keep_unknown_chunks will have no effect. If it is set then known | |
2226 * chunks listed with a keep other than AS_DEFAULT will *never* be processed | |
2227 * by libpng, in addition critical chunks must either be processed by the | |
2228 * callback or saved. | |
2229 * | |
2230 * The IHDR and IEND chunks must not be listed. Because this turns off the | |
2231 * default handling for chunks that would otherwise be recognized the | |
2232 * behavior of libpng transformations may well become incorrect! | |
2233 * | |
2234 * WRITE: | |
2235 * When writing chunks the options only apply to the chunks specified by | |
2236 * png_set_unknown_chunks (below), libpng will *always* write known chunks | |
2237 * required by png_set_ calls and will always write the core critical chunks | |
2238 * (as required for PLTE). | |
2239 * | |
2240 * Each chunk in the png_set_unknown_chunks list is looked up in the | |
2241 * png_set_keep_unknown_chunks list to find the keep setting, this is then | |
2242 * interpreted as follows: | |
2243 * | |
2244 * PNG_HANDLE_CHUNK_AS_DEFAULT: | |
2245 * Write safe-to-copy chunks and write other chunks if the global | |
2246 * default is set to _ALWAYS, otherwise don't write this chunk. | |
2247 * PNG_HANDLE_CHUNK_NEVER: | |
2248 * Do not write the chunk. | |
2249 * PNG_HANDLE_CHUNK_IF_SAFE: | |
2250 * Write the chunk if it is safe-to-copy, otherwise do not write it. | |
2251 * PNG_HANDLE_CHUNK_ALWAYS: | |
2252 * Write the chunk. | |
2253 * | |
2254 * Note that the default behavior is effectively the opposite of the read case - | |
2255 * in read unknown chunks are not stored by default, in write they are written | |
2256 * by default. Also the behavior of PNG_HANDLE_CHUNK_IF_SAFE is very different | |
2257 * - on write the safe-to-copy bit is checked, on read the critical bit is | |
2258 * checked and on read if the chunk is critical an error will be raised. | |
2259 * | |
2260 * num_chunks: | |
2261 * =========== | |
2262 * If num_chunks is positive, then the "keep" parameter specifies the manner | |
2263 * for handling only those chunks appearing in the chunk_list array, | |
2264 * otherwise the chunk list array is ignored. | |
2265 * | |
2266 * If num_chunks is 0 the "keep" parameter specifies the default behavior for | |
2267 * unknown chunks, as described above. | |
2268 * | |
2269 * If num_chunks is negative, then the "keep" parameter specifies the manner | |
2270 * for handling all unknown chunks plus all chunks recognized by libpng | |
2271 * except for the IHDR, PLTE, tRNS, IDAT, and IEND chunks (which continue to | |
2272 * be processed by libpng. | |
2273 */ | |
2274 PNG_EXPORT(172, void, png_set_keep_unknown_chunks, (png_structrp png_ptr, | |
2275 int keep, png_const_bytep chunk_list, int num_chunks)); | |
2276 | |
2277 /* The "keep" PNG_HANDLE_CHUNK_ parameter for the specified chunk is returned; | |
2278 * the result is therefore true (non-zero) if special handling is required, | |
2279 * false for the default handling. | |
2280 */ | |
2281 PNG_EXPORT(173, int, png_handle_as_unknown, (png_const_structrp png_ptr, | |
2282 png_const_bytep chunk_name)); | |
2283 #endif | |
2284 | |
2285 #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED | |
2286 PNG_EXPORT(174, void, png_set_unknown_chunks, (png_const_structrp png_ptr, | |
2287 png_inforp info_ptr, png_const_unknown_chunkp unknowns, | |
2288 int num_unknowns)); | |
2289 /* NOTE: prior to 1.6.0 this routine set the 'location' field of the added | |
2290 * unknowns to the location currently stored in the png_struct. This is | |
2291 * invariably the wrong value on write. To fix this call the following API | |
2292 * for each chunk in the list with the correct location. If you know your | |
2293 * code won't be compiled on earlier versions you can rely on | |
2294 * png_set_unknown_chunks(write-ptr, png_get_unknown_chunks(read-ptr)) doing | |
2295 * the correct thing. | |
2296 */ | |
2297 | |
2298 PNG_EXPORT(175, void, png_set_unknown_chunk_location, | |
2299 (png_const_structrp png_ptr, png_inforp info_ptr, int chunk, int location)); | |
2300 | |
2301 PNG_EXPORT(176, int, png_get_unknown_chunks, (png_const_structrp png_ptr, | |
2302 png_inforp info_ptr, png_unknown_chunkpp entries)); | |
2303 #endif | |
2304 | |
2305 /* Png_free_data() will turn off the "valid" flag for anything it frees. | |
2306 * If you need to turn it off for a chunk that your application has freed, | |
2307 * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK); | |
2308 */ | |
2309 PNG_EXPORT(177, void, png_set_invalid, (png_const_structrp png_ptr, | |
2310 png_inforp info_ptr, int mask)); | |
2311 | |
2312 #ifdef PNG_INFO_IMAGE_SUPPORTED | |
2313 /* The "params" pointer is currently not used and is for future expansion. */ | |
2314 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED | |
2315 PNG_EXPORT(178, void, png_read_png, (png_structrp png_ptr, png_inforp info_ptr, | |
2316 int transforms, png_voidp params)); | |
2317 #endif | |
2318 #ifdef PNG_WRITE_SUPPORTED | |
2319 PNG_EXPORT(179, void, png_write_png, (png_structrp png_ptr, png_inforp info_ptr, | |
2320 int transforms, png_voidp params)); | |
2321 #endif | |
2322 #endif | |
2323 | |
2324 PNG_EXPORT(180, png_const_charp, png_get_copyright, | |
2325 (png_const_structrp png_ptr)); | |
2326 PNG_EXPORT(181, png_const_charp, png_get_header_ver, | |
2327 (png_const_structrp png_ptr)); | |
2328 PNG_EXPORT(182, png_const_charp, png_get_header_version, | |
2329 (png_const_structrp png_ptr)); | |
2330 PNG_EXPORT(183, png_const_charp, png_get_libpng_ver, | |
2331 (png_const_structrp png_ptr)); | |
2332 | |
2333 #ifdef PNG_MNG_FEATURES_SUPPORTED | |
2334 PNG_EXPORT(184, png_uint_32, png_permit_mng_features, (png_structrp png_ptr, | |
2335 png_uint_32 mng_features_permitted)); | |
2336 #endif | |
2337 | |
2338 /* For use in png_set_keep_unknown, added to version 1.2.6 */ | |
2339 #define PNG_HANDLE_CHUNK_AS_DEFAULT 0 | |
2340 #define PNG_HANDLE_CHUNK_NEVER 1 | |
2341 #define PNG_HANDLE_CHUNK_IF_SAFE 2 | |
2342 #define PNG_HANDLE_CHUNK_ALWAYS 3 | |
2343 #define PNG_HANDLE_CHUNK_LAST 4 | |
2344 | |
2345 /* Strip the prepended error numbers ("#nnn ") from error and warning | |
2346 * messages before passing them to the error or warning handler. | |
2347 */ | |
2348 #ifdef PNG_ERROR_NUMBERS_SUPPORTED | |
2349 PNG_EXPORT(185, void, png_set_strip_error_numbers, (png_structrp png_ptr, | |
2350 png_uint_32 strip_mode)); | |
2351 #endif | |
2352 | |
2353 /* Added in libpng-1.2.6 */ | |
2354 #ifdef PNG_SET_USER_LIMITS_SUPPORTED | |
2355 PNG_EXPORT(186, void, png_set_user_limits, (png_structrp png_ptr, | |
2356 png_uint_32 user_width_max, png_uint_32 user_height_max)); | |
2357 PNG_EXPORT(187, png_uint_32, png_get_user_width_max, | |
2358 (png_const_structrp png_ptr)); | |
2359 PNG_EXPORT(188, png_uint_32, png_get_user_height_max, | |
2360 (png_const_structrp png_ptr)); | |
2361 /* Added in libpng-1.4.0 */ | |
2362 PNG_EXPORT(189, void, png_set_chunk_cache_max, (png_structrp png_ptr, | |
2363 png_uint_32 user_chunk_cache_max)); | |
2364 PNG_EXPORT(190, png_uint_32, png_get_chunk_cache_max, | |
2365 (png_const_structrp png_ptr)); | |
2366 /* Added in libpng-1.4.1 */ | |
2367 PNG_EXPORT(191, void, png_set_chunk_malloc_max, (png_structrp png_ptr, | |
2368 png_alloc_size_t user_chunk_cache_max)); | |
2369 PNG_EXPORT(192, png_alloc_size_t, png_get_chunk_malloc_max, | |
2370 (png_const_structrp png_ptr)); | |
2371 #endif | |
2372 | |
2373 #if defined(PNG_INCH_CONVERSIONS_SUPPORTED) | |
2374 PNG_EXPORT(193, png_uint_32, png_get_pixels_per_inch, | |
2375 (png_const_structrp png_ptr, png_const_inforp info_ptr)); | |
2376 | |
2377 PNG_EXPORT(194, png_uint_32, png_get_x_pixels_per_inch, | |
2378 (png_const_structrp png_ptr, png_const_inforp info_ptr)); | |
2379 | |
2380 PNG_EXPORT(195, png_uint_32, png_get_y_pixels_per_inch, | |
2381 (png_const_structrp png_ptr, png_const_inforp info_ptr)); | |
2382 | |
2383 PNG_FP_EXPORT(196, float, png_get_x_offset_inches, | |
2384 (png_const_structrp png_ptr, png_const_inforp info_ptr)) | |
2385 #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */ | |
2386 PNG_FIXED_EXPORT(211, png_fixed_point, png_get_x_offset_inches_fixed, | |
2387 (png_const_structrp png_ptr, png_const_inforp info_ptr)) | |
2388 #endif | |
2389 | |
2390 PNG_FP_EXPORT(197, float, png_get_y_offset_inches, (png_const_structrp png_ptr, | |
2391 png_const_inforp info_ptr)) | |
2392 #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */ | |
2393 PNG_FIXED_EXPORT(212, png_fixed_point, png_get_y_offset_inches_fixed, | |
2394 (png_const_structrp png_ptr, png_const_inforp info_ptr)) | |
2395 #endif | |
2396 | |
2397 # ifdef PNG_pHYs_SUPPORTED | |
2398 PNG_EXPORT(198, png_uint_32, png_get_pHYs_dpi, (png_const_structrp png_ptr, | |
2399 png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, | |
2400 int *unit_type)); | |
2401 # endif /* pHYs */ | |
2402 #endif /* INCH_CONVERSIONS */ | |
2403 | |
2404 /* Added in libpng-1.4.0 */ | |
2405 #ifdef PNG_IO_STATE_SUPPORTED | |
2406 PNG_EXPORT(199, png_uint_32, png_get_io_state, (png_const_structrp png_ptr)); | |
2407 | |
2408 /* Removed from libpng 1.6; use png_get_io_chunk_type. */ | |
2409 PNG_REMOVED(200, png_const_bytep, png_get_io_chunk_name, (png_structrp png_ptr), | |
2410 PNG_DEPRECATED) | |
2411 | |
2412 PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type, | |
2413 (png_const_structrp png_ptr)); | |
2414 | |
2415 /* The flags returned by png_get_io_state() are the following: */ | |
2416 # define PNG_IO_NONE 0x0000 /* no I/O at this moment */ | |
2417 # define PNG_IO_READING 0x0001 /* currently reading */ | |
2418 # define PNG_IO_WRITING 0x0002 /* currently writing */ | |
2419 # define PNG_IO_SIGNATURE 0x0010 /* currently at the file signature */ | |
2420 # define PNG_IO_CHUNK_HDR 0x0020 /* currently at the chunk header */ | |
2421 # define PNG_IO_CHUNK_DATA 0x0040 /* currently at the chunk data */ | |
2422 # define PNG_IO_CHUNK_CRC 0x0080 /* currently at the chunk crc */ | |
2423 # define PNG_IO_MASK_OP 0x000f /* current operation: reading/writing */ | |
2424 # define PNG_IO_MASK_LOC 0x00f0 /* current location: sig/hdr/data/crc */ | |
2425 #endif /* IO_STATE */ | |
2426 | |
2427 /* Interlace support. The following macros are always defined so that if | |
2428 * libpng interlace handling is turned off the macros may be used to handle | |
2429 * interlaced images within the application. | |
2430 */ | |
2431 #define PNG_INTERLACE_ADAM7_PASSES 7 | |
2432 | |
2433 /* Two macros to return the first row and first column of the original, | |
2434 * full, image which appears in a given pass. 'pass' is in the range 0 | |
2435 * to 6 and the result is in the range 0 to 7. | |
2436 */ | |
2437 #define PNG_PASS_START_ROW(pass) (((1&~(pass))<<(3-((pass)>>1)))&7) | |
2438 #define PNG_PASS_START_COL(pass) (((1& (pass))<<(3-(((pass)+1)>>1)))&7) | |
2439 | |
2440 /* A macro to return the offset between pixels in the output row for a pair of | |
2441 * pixels in the input - effectively the inverse of the 'COL_SHIFT' macro that | |
2442 * follows. Note that ROW_OFFSET is the offset from one row to the next whereas | |
2443 * COL_OFFSET is from one column to the next, within a row. | |
2444 */ | |
2445 #define PNG_PASS_ROW_OFFSET(pass) ((pass)>2?(8>>(((pass)-1)>>1)):8) | |
2446 #define PNG_PASS_COL_OFFSET(pass) (1<<((7-(pass))>>1)) | |
2447 | |
2448 /* Two macros to help evaluate the number of rows or columns in each | |
2449 * pass. This is expressed as a shift - effectively log2 of the number or | |
2450 * rows or columns in each 8x8 tile of the original image. | |
2451 */ | |
2452 #define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3) | |
2453 #define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3) | |
2454 | |
2455 /* Hence two macros to determine the number of rows or columns in a given | |
2456 * pass of an image given its height or width. In fact these macros may | |
2457 * return non-zero even though the sub-image is empty, because the other | |
2458 * dimension may be empty for a small image. | |
2459 */ | |
2460 #define PNG_PASS_ROWS(height, pass) (((height)+(((1<<PNG_PASS_ROW_SHIFT(pass))\ | |
2461 -1)-PNG_PASS_START_ROW(pass)))>>PNG_PASS_ROW_SHIFT(pass)) | |
2462 #define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\ | |
2463 -1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass)) | |
2464 | |
2465 /* For the reader row callbacks (both progressive and sequential) it is | |
2466 * necessary to find the row in the output image given a row in an interlaced | |
2467 * image, so two more macros: | |
2468 */ | |
2469 #define PNG_ROW_FROM_PASS_ROW(y_in, pass) \ | |
2470 (((y_in)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass)) | |
2471 #define PNG_COL_FROM_PASS_COL(x_in, pass) \ | |
2472 (((x_in)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass)) | |
2473 | |
2474 /* Two macros which return a boolean (0 or 1) saying whether the given row | |
2475 * or column is in a particular pass. These use a common utility macro that | |
2476 * returns a mask for a given pass - the offset 'off' selects the row or | |
2477 * column version. The mask has the appropriate bit set for each column in | |
2478 * the tile. | |
2479 */ | |
2480 #define PNG_PASS_MASK(pass,off) ( \ | |
2481 ((0x110145AF>>(((7-(off))-(pass))<<2)) & 0xF) | \ | |
2482 ((0x01145AF0>>(((7-(off))-(pass))<<2)) & 0xF0)) | |
2483 | |
2484 #define PNG_ROW_IN_INTERLACE_PASS(y, pass) \ | |
2485 ((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1) | |
2486 #define PNG_COL_IN_INTERLACE_PASS(x, pass) \ | |
2487 ((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1) | |
2488 | |
2489 #ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED | |
2490 /* With these routines we avoid an integer divide, which will be slower on | |
2491 * most machines. However, it does take more operations than the corresponding | |
2492 * divide method, so it may be slower on a few RISC systems. There are two | |
2493 * shifts (by 8 or 16 bits) and an addition, versus a single integer divide. | |
2494 * | |
2495 * Note that the rounding factors are NOT supposed to be the same! 128 and | |
2496 * 32768 are correct for the NODIV code; 127 and 32767 are correct for the | |
2497 * standard method. | |
2498 * | |
2499 * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ] | |
2500 */ | |
2501 | |
2502 /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */ | |
2503 | |
2504 # define png_composite(composite, fg, alpha, bg) \ | |
2505 { png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \ | |
2506 * (png_uint_16)(alpha) \ | |
2507 + (png_uint_16)(bg)*(png_uint_16)(255 \ | |
2508 - (png_uint_16)(alpha)) + 128); \ | |
2509 (composite) = (png_byte)(((temp + (temp >> 8)) >> 8) & 0xff); } | |
2510 | |
2511 # define png_composite_16(composite, fg, alpha, bg) \ | |
2512 { png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) \ | |
2513 * (png_uint_32)(alpha) \ | |
2514 + (png_uint_32)(bg)*(65535 \ | |
2515 - (png_uint_32)(alpha)) + 32768); \ | |
2516 (composite) = (png_uint_16)(0xffff & ((temp + (temp >> 16)) >> 16)); } | |
2517 | |
2518 #else /* Standard method using integer division */ | |
2519 | |
2520 # define png_composite(composite, fg, alpha, bg) \ | |
2521 (composite) = \ | |
2522 (png_byte)(0xff & (((png_uint_16)(fg) * (png_uint_16)(alpha) + \ | |
2523 (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \ | |
2524 127) / 255)) | |
2525 | |
2526 # define png_composite_16(composite, fg, alpha, bg) \ | |
2527 (composite) = \ | |
2528 (png_uint_16)(0xffff & (((png_uint_32)(fg) * (png_uint_32)(alpha) + \ | |
2529 (png_uint_32)(bg)*(png_uint_32)(65535 - (png_uint_32)(alpha)) + \ | |
2530 32767) / 65535)) | |
2531 #endif /* READ_COMPOSITE_NODIV */ | |
2532 | |
2533 #ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED | |
2534 PNG_EXPORT(201, png_uint_32, png_get_uint_32, (png_const_bytep buf)); | |
2535 PNG_EXPORT(202, png_uint_16, png_get_uint_16, (png_const_bytep buf)); | |
2536 PNG_EXPORT(203, png_int_32, png_get_int_32, (png_const_bytep buf)); | |
2537 #endif | |
2538 | |
2539 PNG_EXPORT(204, png_uint_32, png_get_uint_31, (png_const_structrp png_ptr, | |
2540 png_const_bytep buf)); | |
2541 /* No png_get_int_16 -- may be added if there's a real need for it. */ | |
2542 | |
2543 /* Place a 32-bit number into a buffer in PNG byte order (big-endian). */ | |
2544 #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED | |
2545 PNG_EXPORT(205, void, png_save_uint_32, (png_bytep buf, png_uint_32 i)); | |
2546 #endif | |
2547 #ifdef PNG_SAVE_INT_32_SUPPORTED | |
2548 PNG_EXPORT(206, void, png_save_int_32, (png_bytep buf, png_int_32 i)); | |
2549 #endif | |
2550 | |
2551 /* Place a 16-bit number into a buffer in PNG byte order. | |
2552 * The parameter is declared unsigned int, not png_uint_16, | |
2553 * just to avoid potential problems on pre-ANSI C compilers. | |
2554 */ | |
2555 #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED | |
2556 PNG_EXPORT(207, void, png_save_uint_16, (png_bytep buf, unsigned int i)); | |
2557 /* No png_save_int_16 -- may be added if there's a real need for it. */ | |
2558 #endif | |
2559 | |
2560 #ifdef PNG_USE_READ_MACROS | |
2561 /* Inline macros to do direct reads of bytes from the input buffer. | |
2562 * The png_get_int_32() routine assumes we are using two's complement | |
2563 * format for negative values, which is almost certainly true. | |
2564 */ | |
2565 # define PNG_get_uint_32(buf) \ | |
2566 (((png_uint_32)(*(buf)) << 24) + \ | |
2567 ((png_uint_32)(*((buf) + 1)) << 16) + \ | |
2568 ((png_uint_32)(*((buf) + 2)) << 8) + \ | |
2569 ((png_uint_32)(*((buf) + 3)))) | |
2570 | |
2571 /* From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the | |
2572 * function) incorrectly returned a value of type png_uint_32. | |
2573 */ | |
2574 # define PNG_get_uint_16(buf) \ | |
2575 ((png_uint_16) \ | |
2576 (((unsigned int)(*(buf)) << 8) + \ | |
2577 ((unsigned int)(*((buf) + 1))))) | |
2578 | |
2579 # define PNG_get_int_32(buf) \ | |
2580 ((png_int_32)((*(buf) & 0x80) \ | |
2581 ? -((png_int_32)(((png_get_uint_32(buf)^0xffffffffU)+1U)&0x7fffffffU)) \ | |
2582 : (png_int_32)png_get_uint_32(buf))) | |
2583 | |
2584 /* If PNG_PREFIX is defined the same thing as below happens in pnglibconf.h, | |
2585 * but defining a macro name prefixed with PNG_PREFIX. | |
2586 */ | |
2587 # ifndef PNG_PREFIX | |
2588 # define png_get_uint_32(buf) PNG_get_uint_32(buf) | |
2589 # define png_get_uint_16(buf) PNG_get_uint_16(buf) | |
2590 # define png_get_int_32(buf) PNG_get_int_32(buf) | |
2591 # endif | |
2592 #else | |
2593 # ifdef PNG_PREFIX | |
2594 /* No macros; revert to the (redefined) function */ | |
2595 # define PNG_get_uint_32 (png_get_uint_32) | |
2596 # define PNG_get_uint_16 (png_get_uint_16) | |
2597 # define PNG_get_int_32 (png_get_int_32) | |
2598 # endif | |
2599 #endif | |
2600 | |
2601 #ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED | |
2602 PNG_EXPORT(242, void, png_set_check_for_invalid_index, | |
2603 (png_structrp png_ptr, int allowed)); | |
2604 # ifdef PNG_GET_PALETTE_MAX_SUPPORTED | |
2605 PNG_EXPORT(243, int, png_get_palette_max, (png_const_structp png_ptr, | |
2606 png_const_infop info_ptr)); | |
2607 # endif | |
2608 #endif /* CHECK_FOR_INVALID_INDEX */ | |
2609 | |
2610 /******************************************************************************* | |
2611 * Section 5: SIMPLIFIED API | |
2612 ******************************************************************************* | |
2613 * | |
2614 * Please read the documentation in libpng-manual.txt (TODO: write said | |
2615 * documentation) if you don't understand what follows. | |
2616 * | |
2617 * The simplified API hides the details of both libpng and the PNG file format | |
2618 * itself. It allows PNG files to be read into a very limited number of | |
2619 * in-memory bitmap formats or to be written from the same formats. If these | |
2620 * formats do not accomodate your needs then you can, and should, use the more | |
2621 * sophisticated APIs above - these support a wide variety of in-memory formats | |
2622 * and a wide variety of sophisticated transformations to those formats as well | |
2623 * as a wide variety of APIs to manipulate ancillary information. | |
2624 * | |
2625 * To read a PNG file using the simplified API: | |
2626 * | |
2627 * 1) Declare a 'png_image' structure (see below) on the stack, set the | |
2628 * version field to PNG_IMAGE_VERSION and the 'opaque' pointer to NULL | |
2629 * (this is REQUIRED, your program may crash if you don't do it.) | |
2630 * 2) Call the appropriate png_image_begin_read... function. | |
2631 * 3) Set the png_image 'format' member to the required sample format. | |
2632 * 4) Allocate a buffer for the image and, if required, the color-map. | |
2633 * 5) Call png_image_finish_read to read the image and, if required, the | |
2634 * color-map into your buffers. | |
2635 * | |
2636 * There are no restrictions on the format of the PNG input itself; all valid | |
2637 * color types, bit depths, and interlace methods are acceptable, and the | |
2638 * input image is transformed as necessary to the requested in-memory format | |
2639 * during the png_image_finish_read() step. The only caveat is that if you | |
2640 * request a color-mapped image from a PNG that is full-color or makes | |
2641 * complex use of an alpha channel the transformation is extremely lossy and the | |
2642 * result may look terrible. | |
2643 * | |
2644 * To write a PNG file using the simplified API: | |
2645 * | |
2646 * 1) Declare a 'png_image' structure on the stack and memset() it to all zero. | |
2647 * 2) Initialize the members of the structure that describe the image, setting | |
2648 * the 'format' member to the format of the image samples. | |
2649 * 3) Call the appropriate png_image_write... function with a pointer to the | |
2650 * image and, if necessary, the color-map to write the PNG data. | |
2651 * | |
2652 * png_image is a structure that describes the in-memory format of an image | |
2653 * when it is being read or defines the in-memory format of an image that you | |
2654 * need to write: | |
2655 */ | |
2656 #if defined(PNG_SIMPLIFIED_READ_SUPPORTED) || \ | |
2657 defined(PNG_SIMPLIFIED_WRITE_SUPPORTED) | |
2658 | |
2659 #define PNG_IMAGE_VERSION 1 | |
2660 | |
2661 typedef struct png_control *png_controlp; | |
2662 typedef struct | |
2663 { | |
2664 png_controlp opaque; /* Initialize to NULL, free with png_image_free */ | |
2665 png_uint_32 version; /* Set to PNG_IMAGE_VERSION */ | |
2666 png_uint_32 width; /* Image width in pixels (columns) */ | |
2667 png_uint_32 height; /* Image height in pixels (rows) */ | |
2668 png_uint_32 format; /* Image format as defined below */ | |
2669 png_uint_32 flags; /* A bit mask containing informational flags */ | |
2670 png_uint_32 colormap_entries; | |
2671 /* Number of entries in the color-map */ | |
2672 | |
2673 /* In the event of an error or warning the following field will be set to a | |
2674 * non-zero value and the 'message' field will contain a '\0' terminated | |
2675 * string with the libpng error or warning message. If both warnings and | |
2676 * an error were encountered, only the error is recorded. If there | |
2677 * are multiple warnings, only the first one is recorded. | |
2678 * | |
2679 * The upper 30 bits of this value are reserved, the low two bits contain | |
2680 * a value as follows: | |
2681 */ | |
2682 # define PNG_IMAGE_WARNING 1 | |
2683 # define PNG_IMAGE_ERROR 2 | |
2684 /* | |
2685 * The result is a two-bit code such that a value more than 1 indicates | |
2686 * a failure in the API just called: | |
2687 * | |
2688 * 0 - no warning or error | |
2689 * 1 - warning | |
2690 * 2 - error | |
2691 * 3 - error preceded by warning | |
2692 */ | |
2693 # define PNG_IMAGE_FAILED(png_cntrl) ((((png_cntrl).warning_or_error)&0x03)>1) | |
2694 | |
2695 png_uint_32 warning_or_error; | |
2696 | |
2697 char message[64]; | |
2698 } png_image, *png_imagep; | |
2699 | |
2700 /* The samples of the image have one to four channels whose components have | |
2701 * original values in the range 0 to 1.0: | |
2702 * | |
2703 * 1: A single gray or luminance channel (G). | |
2704 * 2: A gray/luminance channel and an alpha channel (GA). | |
2705 * 3: Three red, green, blue color channels (RGB). | |
2706 * 4: Three color channels and an alpha channel (RGBA). | |
2707 * | |
2708 * The components are encoded in one of two ways: | |
2709 * | |
2710 * a) As a small integer, value 0..255, contained in a single byte. For the | |
2711 * alpha channel the original value is simply value/255. For the color or | |
2712 * luminance channels the value is encoded according to the sRGB specification | |
2713 * and matches the 8-bit format expected by typical display devices. | |
2714 * | |
2715 * The color/gray channels are not scaled (pre-multiplied) by the alpha | |
2716 * channel and are suitable for passing to color management software. | |
2717 * | |
2718 * b) As a value in the range 0..65535, contained in a 2-byte integer. All | |
2719 * channels can be converted to the original value by dividing by 65535; all | |
2720 * channels are linear. Color channels use the RGB encoding (RGB end-points) of | |
2721 * the sRGB specification. This encoding is identified by the | |
2722 * PNG_FORMAT_FLAG_LINEAR flag below. | |
2723 * | |
2724 * When the simplified API needs to convert between sRGB and linear colorspaces, | |
2725 * the actual sRGB transfer curve defined in the sRGB specification (see the | |
2726 * article at http://en.wikipedia.org/wiki/SRGB) is used, not the gamma=1/2.2 | |
2727 * approximation used elsewhere in libpng. | |
2728 * | |
2729 * When an alpha channel is present it is expected to denote pixel coverage | |
2730 * of the color or luminance channels and is returned as an associated alpha | |
2731 * channel: the color/gray channels are scaled (pre-multiplied) by the alpha | |
2732 * value. | |
2733 * | |
2734 * The samples are either contained directly in the image data, between 1 and 8 | |
2735 * bytes per pixel according to the encoding, or are held in a color-map indexed | |
2736 * by bytes in the image data. In the case of a color-map the color-map entries | |
2737 * are individual samples, encoded as above, and the image data has one byte per | |
2738 * pixel to select the relevant sample from the color-map. | |
2739 */ | |
2740 | |
2741 /* PNG_FORMAT_* | |
2742 * | |
2743 * #defines to be used in png_image::format. Each #define identifies a | |
2744 * particular layout of sample data and, if present, alpha values. There are | |
2745 * separate defines for each of the two component encodings. | |
2746 * | |
2747 * A format is built up using single bit flag values. All combinations are | |
2748 * valid. Formats can be built up from the flag values or you can use one of | |
2749 * the predefined values below. When testing formats always use the FORMAT_FLAG | |
2750 * macros to test for individual features - future versions of the library may | |
2751 * add new flags. | |
2752 * | |
2753 * When reading or writing color-mapped images the format should be set to the | |
2754 * format of the entries in the color-map then png_image_{read,write}_colormap | |
2755 * called to read or write the color-map and set the format correctly for the | |
2756 * image data. Do not set the PNG_FORMAT_FLAG_COLORMAP bit directly! | |
2757 * | |
2758 * NOTE: libpng can be built with particular features disabled. If you see | |
2759 * compiler errors because the definition of one of the following flags has been | |
2760 * compiled out it is because libpng does not have the required support. It is | |
2761 * possible, however, for the libpng configuration to enable the format on just | |
2762 * read or just write; in that case you may see an error at run time. You can | |
2763 * guard against this by checking for the definition of the appropriate | |
2764 * "_SUPPORTED" macro, one of: | |
2765 * | |
2766 * PNG_SIMPLIFIED_{READ,WRITE}_{BGR,AFIRST}_SUPPORTED | |
2767 */ | |
2768 #define PNG_FORMAT_FLAG_ALPHA 0x01U /* format with an alpha channel */ | |
2769 #define PNG_FORMAT_FLAG_COLOR 0x02U /* color format: otherwise grayscale */ | |
2770 #define PNG_FORMAT_FLAG_LINEAR 0x04U /* 2-byte channels else 1-byte */ | |
2771 #define PNG_FORMAT_FLAG_COLORMAP 0x08U /* image data is color-mapped */ | |
2772 | |
2773 #ifdef PNG_FORMAT_BGR_SUPPORTED | |
2774 # define PNG_FORMAT_FLAG_BGR 0x10U /* BGR colors, else order is RGB */ | |
2775 #endif | |
2776 | |
2777 #ifdef PNG_FORMAT_AFIRST_SUPPORTED | |
2778 # define PNG_FORMAT_FLAG_AFIRST 0x20U /* alpha channel comes first */ | |
2779 #endif | |
2780 | |
2781 /* Commonly used formats have predefined macros. | |
2782 * | |
2783 * First the single byte (sRGB) formats: | |
2784 */ | |
2785 #define PNG_FORMAT_GRAY 0 | |
2786 #define PNG_FORMAT_GA PNG_FORMAT_FLAG_ALPHA | |
2787 #define PNG_FORMAT_AG (PNG_FORMAT_GA|PNG_FORMAT_FLAG_AFIRST) | |
2788 #define PNG_FORMAT_RGB PNG_FORMAT_FLAG_COLOR | |
2789 #define PNG_FORMAT_BGR (PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_BGR) | |
2790 #define PNG_FORMAT_RGBA (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_ALPHA) | |
2791 #define PNG_FORMAT_ARGB (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_AFIRST) | |
2792 #define PNG_FORMAT_BGRA (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_ALPHA) | |
2793 #define PNG_FORMAT_ABGR (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_AFIRST) | |
2794 | |
2795 /* Then the linear 2-byte formats. When naming these "Y" is used to | |
2796 * indicate a luminance (gray) channel. | |
2797 */ | |
2798 #define PNG_FORMAT_LINEAR_Y PNG_FORMAT_FLAG_LINEAR | |
2799 #define PNG_FORMAT_LINEAR_Y_ALPHA (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_ALPHA) | |
2800 #define PNG_FORMAT_LINEAR_RGB (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR) | |
2801 #define PNG_FORMAT_LINEAR_RGB_ALPHA \ | |
2802 (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA) | |
2803 | |
2804 /* With color-mapped formats the image data is one byte for each pixel, the byte | |
2805 * is an index into the color-map which is formatted as above. To obtain a | |
2806 * color-mapped format it is sufficient just to add the PNG_FOMAT_FLAG_COLORMAP | |
2807 * to one of the above definitions, or you can use one of the definitions below. | |
2808 */ | |
2809 #define PNG_FORMAT_RGB_COLORMAP (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_COLORMAP) | |
2810 #define PNG_FORMAT_BGR_COLORMAP (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_COLORMAP) | |
2811 #define PNG_FORMAT_RGBA_COLORMAP (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_COLORMAP) | |
2812 #define PNG_FORMAT_ARGB_COLORMAP (PNG_FORMAT_ARGB|PNG_FORMAT_FLAG_COLORMAP) | |
2813 #define PNG_FORMAT_BGRA_COLORMAP (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_COLORMAP) | |
2814 #define PNG_FORMAT_ABGR_COLORMAP (PNG_FORMAT_ABGR|PNG_FORMAT_FLAG_COLORMAP) | |
2815 | |
2816 /* PNG_IMAGE macros | |
2817 * | |
2818 * These are convenience macros to derive information from a png_image | |
2819 * structure. The PNG_IMAGE_SAMPLE_ macros return values appropriate to the | |
2820 * actual image sample values - either the entries in the color-map or the | |
2821 * pixels in the image. The PNG_IMAGE_PIXEL_ macros return corresponding values | |
2822 * for the pixels and will always return 1 for color-mapped formats. The | |
2823 * remaining macros return information about the rows in the image and the | |
2824 * complete image. | |
2825 * | |
2826 * NOTE: All the macros that take a png_image::format parameter are compile time | |
2827 * constants if the format parameter is, itself, a constant. Therefore these | |
2828 * macros can be used in array declarations and case labels where required. | |
2829 * Similarly the macros are also pre-processor constants (sizeof is not used) so | |
2830 * they can be used in #if tests. | |
2831 * | |
2832 * First the information about the samples. | |
2833 */ | |
2834 #define PNG_IMAGE_SAMPLE_CHANNELS(fmt)\ | |
2835 (((fmt)&(PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA))+1) | |
2836 /* Return the total number of channels in a given format: 1..4 */ | |
2837 | |
2838 #define PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)\ | |
2839 ((((fmt) & PNG_FORMAT_FLAG_LINEAR) >> 2)+1) | |
2840 /* Return the size in bytes of a single component of a pixel or color-map | |
2841 * entry (as appropriate) in the image: 1 or 2. | |
2842 */ | |
2843 | |
2844 #define PNG_IMAGE_SAMPLE_SIZE(fmt)\ | |
2845 (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)) | |
2846 /* This is the size of the sample data for one sample. If the image is | |
2847 * color-mapped it is the size of one color-map entry (and image pixels are | |
2848 * one byte in size), otherwise it is the size of one image pixel. | |
2849 */ | |
2850 | |
2851 #define PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(fmt)\ | |
2852 (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * 256) | |
2853 /* The maximum size of the color-map required by the format expressed in a | |
2854 * count of components. This can be used to compile-time allocate a | |
2855 * color-map: | |
2856 * | |
2857 * png_uint_16 colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(linear_fmt)]; | |
2858 * | |
2859 * png_byte colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(sRGB_fmt)]; | |
2860 * | |
2861 * Alternatively use the PNG_IMAGE_COLORMAP_SIZE macro below to use the | |
2862 * information from one of the png_image_begin_read_ APIs and dynamically | |
2863 * allocate the required memory. | |
2864 */ | |
2865 | |
2866 /* Corresponding information about the pixels */ | |
2867 #define PNG_IMAGE_PIXEL_(test,fmt)\ | |
2868 (((fmt)&PNG_FORMAT_FLAG_COLORMAP)?1:test(fmt)) | |
2869 | |
2870 #define PNG_IMAGE_PIXEL_CHANNELS(fmt)\ | |
2871 PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_CHANNELS,fmt) | |
2872 /* The number of separate channels (components) in a pixel; 1 for a | |
2873 * color-mapped image. | |
2874 */ | |
2875 | |
2876 #define PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt)\ | |
2877 PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_COMPONENT_SIZE,fmt) | |
2878 /* The size, in bytes, of each component in a pixel; 1 for a color-mapped | |
2879 * image. | |
2880 */ | |
2881 | |
2882 #define PNG_IMAGE_PIXEL_SIZE(fmt) PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_SIZE,fmt) | |
2883 /* The size, in bytes, of a complete pixel; 1 for a color-mapped image. */ | |
2884 | |
2885 /* Information about the whole row, or whole image */ | |
2886 #define PNG_IMAGE_ROW_STRIDE(image)\ | |
2887 (PNG_IMAGE_PIXEL_CHANNELS((image).format) * (image).width) | |
2888 /* Return the total number of components in a single row of the image; this | |
2889 * is the minimum 'row stride', the minimum count of components between each | |
2890 * row. For a color-mapped image this is the minimum number of bytes in a | |
2891 * row. | |
2892 */ | |
2893 | |
2894 #define PNG_IMAGE_BUFFER_SIZE(image, row_stride)\ | |
2895 (PNG_IMAGE_PIXEL_COMPONENT_SIZE((image).format)*(image).height*(row_stride)) | |
2896 /* Return the size, in bytes, of an image buffer given a png_image and a row | |
2897 * stride - the number of components to leave space for in each row. | |
2898 */ | |
2899 | |
2900 #define PNG_IMAGE_SIZE(image)\ | |
2901 PNG_IMAGE_BUFFER_SIZE(image, PNG_IMAGE_ROW_STRIDE(image)) | |
2902 /* Return the size, in bytes, of the image in memory given just a png_image; | |
2903 * the row stride is the minimum stride required for the image. | |
2904 */ | |
2905 | |
2906 #define PNG_IMAGE_COLORMAP_SIZE(image)\ | |
2907 (PNG_IMAGE_SAMPLE_SIZE((image).format) * (image).colormap_entries) | |
2908 /* Return the size, in bytes, of the color-map of this image. If the image | |
2909 * format is not a color-map format this will return a size sufficient for | |
2910 * 256 entries in the given format; check PNG_FORMAT_FLAG_COLORMAP if | |
2911 * you don't want to allocate a color-map in this case. | |
2912 */ | |
2913 | |
2914 /* PNG_IMAGE_FLAG_* | |
2915 * | |
2916 * Flags containing additional information about the image are held in the | |
2917 * 'flags' field of png_image. | |
2918 */ | |
2919 #define PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB 0x01 | |
2920 /* This indicates the the RGB values of the in-memory bitmap do not | |
2921 * correspond to the red, green and blue end-points defined by sRGB. | |
2922 */ | |
2923 | |
2924 #define PNG_IMAGE_FLAG_FAST 0x02 | |
2925 /* On write emphasise speed over compression; the resultant PNG file will be | |
2926 * larger but will be produced significantly faster, particular for large | |
2927 * images. Do not use this option for images which will be distributed, only | |
2928 * used it when producing intermediate files that will be read back in | |
2929 * repeatedly. For a typical 24-bit image the option will double the read | |
2930 * speed at the cost of increasing the image size by 25%, however for many | |
2931 * more compressible images the PNG file can be 10 times larger with only a | |
2932 * slight speed gain. | |
2933 */ | |
2934 | |
2935 #define PNG_IMAGE_FLAG_16BIT_sRGB 0x04 | |
2936 /* On read if the image is a 16-bit per component image and there is no gAMA | |
2937 * or sRGB chunk assume that the components are sRGB encoded. Notice that | |
2938 * images output by the simplified API always have gamma information; setting | |
2939 * this flag only affects the interpretation of 16-bit images from an | |
2940 * external source. It is recommended that the application expose this flag | |
2941 * to the user; the user can normally easily recognize the difference between | |
2942 * linear and sRGB encoding. This flag has no effect on write - the data | |
2943 * passed to the write APIs must have the correct encoding (as defined | |
2944 * above.) | |
2945 * | |
2946 * If the flag is not set (the default) input 16-bit per component data is | |
2947 * assumed to be linear. | |
2948 * | |
2949 * NOTE: the flag can only be set after the png_image_begin_read_ call, | |
2950 * because that call initializes the 'flags' field. | |
2951 */ | |
2952 | |
2953 #ifdef PNG_SIMPLIFIED_READ_SUPPORTED | |
2954 /* READ APIs | |
2955 * --------- | |
2956 * | |
2957 * The png_image passed to the read APIs must have been initialized by setting | |
2958 * the png_controlp field 'opaque' to NULL (or, safer, memset the whole thing.) | |
2959 */ | |
2960 #ifdef PNG_STDIO_SUPPORTED | |
2961 PNG_EXPORT(234, int, png_image_begin_read_from_file, (png_imagep image, | |
2962 const char *file_name)); | |
2963 /* The named file is opened for read and the image header is filled in | |
2964 * from the PNG header in the file. | |
2965 */ | |
2966 | |
2967 PNG_EXPORT(235, int, png_image_begin_read_from_stdio, (png_imagep image, | |
2968 FILE* file)); | |
2969 /* The PNG header is read from the stdio FILE object. */ | |
2970 #endif /* STDIO */ | |
2971 | |
2972 PNG_EXPORT(236, int, png_image_begin_read_from_memory, (png_imagep image, | |
2973 png_const_voidp memory, png_size_t size)); | |
2974 /* The PNG header is read from the given memory buffer. */ | |
2975 | |
2976 PNG_EXPORT(237, int, png_image_finish_read, (png_imagep image, | |
2977 png_const_colorp background, void *buffer, png_int_32 row_stride, | |
2978 void *colormap)); | |
2979 /* Finish reading the image into the supplied buffer and clean up the | |
2980 * png_image structure. | |
2981 * | |
2982 * row_stride is the step, in byte or 2-byte units as appropriate, | |
2983 * between adjacent rows. A positive stride indicates that the top-most row | |
2984 * is first in the buffer - the normal top-down arrangement. A negative | |
2985 * stride indicates that the bottom-most row is first in the buffer. | |
2986 * | |
2987 * background need only be supplied if an alpha channel must be removed from | |
2988 * a png_byte format and the removal is to be done by compositing on a solid | |
2989 * color; otherwise it may be NULL and any composition will be done directly | |
2990 * onto the buffer. The value is an sRGB color to use for the background, | |
2991 * for grayscale output the green channel is used. | |
2992 * | |
2993 * background must be supplied when an alpha channel must be removed from a | |
2994 * single byte color-mapped output format, in other words if: | |
2995 * | |
2996 * 1) The original format from png_image_begin_read_from_* had | |
2997 * PNG_FORMAT_FLAG_ALPHA set. | |
2998 * 2) The format set by the application does not. | |
2999 * 3) The format set by the application has PNG_FORMAT_FLAG_COLORMAP set and | |
3000 * PNG_FORMAT_FLAG_LINEAR *not* set. | |
3001 * | |
3002 * For linear output removing the alpha channel is always done by compositing | |
3003 * on black and background is ignored. | |
3004 * | |
3005 * colormap must be supplied when PNG_FORMAT_FLAG_COLORMAP is set. It must | |
3006 * be at least the size (in bytes) returned by PNG_IMAGE_COLORMAP_SIZE. | |
3007 * image->colormap_entries will be updated to the actual number of entries | |
3008 * written to the colormap; this may be less than the original value. | |
3009 */ | |
3010 | |
3011 PNG_EXPORT(238, void, png_image_free, (png_imagep image)); | |
3012 /* Free any data allocated by libpng in image->opaque, setting the pointer to | |
3013 * NULL. May be called at any time after the structure is initialized. | |
3014 */ | |
3015 #endif /* SIMPLIFIED_READ */ | |
3016 | |
3017 #ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED | |
3018 #ifdef PNG_STDIO_SUPPORTED | |
3019 /* WRITE APIS | |
3020 * ---------- | |
3021 * For write you must initialize a png_image structure to describe the image to | |
3022 * be written. To do this use memset to set the whole structure to 0 then | |
3023 * initialize fields describing your image. | |
3024 * | |
3025 * version: must be set to PNG_IMAGE_VERSION | |
3026 * opaque: must be initialized to NULL | |
3027 * width: image width in pixels | |
3028 * height: image height in rows | |
3029 * format: the format of the data (image and color-map) you wish to write | |
3030 * flags: set to 0 unless one of the defined flags applies; set | |
3031 * PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB for color format images where the RGB | |
3032 * values do not correspond to the colors in sRGB. | |
3033 * colormap_entries: set to the number of entries in the color-map (0 to 256) | |
3034 */ | |
3035 PNG_EXPORT(239, int, png_image_write_to_file, (png_imagep image, | |
3036 const char *file, int convert_to_8bit, const void *buffer, | |
3037 png_int_32 row_stride, const void *colormap)); | |
3038 /* Write the image to the named file. */ | |
3039 | |
3040 PNG_EXPORT(240, int, png_image_write_to_stdio, (png_imagep image, FILE *file, | |
3041 int convert_to_8_bit, const void *buffer, png_int_32 row_stride, | |
3042 const void *colormap)); | |
3043 /* Write the image to the given (FILE*). */ | |
3044 | |
3045 /* With both write APIs if image is in one of the linear formats with 16-bit | |
3046 * data then setting convert_to_8_bit will cause the output to be an 8-bit PNG | |
3047 * gamma encoded according to the sRGB specification, otherwise a 16-bit linear | |
3048 * encoded PNG file is written. | |
3049 * | |
3050 * With color-mapped data formats the colormap parameter point to a color-map | |
3051 * with at least image->colormap_entries encoded in the specified format. If | |
3052 * the format is linear the written PNG color-map will be converted to sRGB | |
3053 * regardless of the convert_to_8_bit flag. | |
3054 * | |
3055 * With all APIs row_stride is handled as in the read APIs - it is the spacing | |
3056 * from one row to the next in component sized units (1 or 2 bytes) and if | |
3057 * negative indicates a bottom-up row layout in the buffer. If row_stride is ze
ro, | |
3058 * libpng will calculate it for you from the image width and number of channels. | |
3059 * | |
3060 * Note that the write API does not support interlacing, sub-8-bit pixels, index
ed | |
3061 * PNG (color_type 3) or most ancillary chunks. | |
3062 */ | |
3063 #endif /* STDIO */ | |
3064 #endif /* SIMPLIFIED_WRITE */ | |
3065 /******************************************************************************* | |
3066 * END OF SIMPLIFIED API | |
3067 ******************************************************************************/ | |
3068 #endif /* SIMPLIFIED_{READ|WRITE} */ | |
3069 | |
3070 /******************************************************************************* | |
3071 * Section 6: IMPLEMENTATION OPTIONS | |
3072 ******************************************************************************* | |
3073 * | |
3074 * Support for arbitrary implementation-specific optimizations. The API allows | |
3075 * particular options to be turned on or off. 'Option' is the number of the | |
3076 * option and 'onoff' is 0 (off) or non-0 (on). The value returned is given | |
3077 * by the PNG_OPTION_ defines below. | |
3078 * | |
3079 * HARDWARE: normally hardware capabilites, such as the Intel SSE instructions, | |
3080 * are detected at run time, however sometimes it may be impossible | |
3081 * to do this in user mode, in which case it is necessary to discover | |
3082 * the capabilities in an OS specific way. Such capabilities are | |
3083 * listed here when libpng has support for them and must be turned | |
3084 * ON by the application if present. | |
3085 * | |
3086 * SOFTWARE: sometimes software optimizations actually result in performance | |
3087 * decrease on some architectures or systems, or with some sets of | |
3088 * PNG images. 'Software' options allow such optimizations to be | |
3089 * selected at run time. | |
3090 */ | |
3091 #ifdef PNG_SET_OPTION_SUPPORTED | |
3092 #ifdef PNG_ARM_NEON_API_SUPPORTED | |
3093 # define PNG_ARM_NEON 0 /* HARDWARE: ARM Neon SIMD instructions supported */ | |
3094 #endif | |
3095 #define PNG_MAXIMUM_INFLATE_WINDOW 2 /* SOFTWARE: force maximum window */ | |
3096 #define PNG_SKIP_sRGB_CHECK_PROFILE 4 /* SOFTWARE: Check ICC profile for sRGB */ | |
3097 #define PNG_OPTION_NEXT 6 /* Next option - numbers must be even */ | |
3098 | |
3099 /* Return values: NOTE: there are four values and 'off' is *not* zero */ | |
3100 #define PNG_OPTION_UNSET 0 /* Unset - defaults to off */ | |
3101 #define PNG_OPTION_INVALID 1 /* Option number out of range */ | |
3102 #define PNG_OPTION_OFF 2 | |
3103 #define PNG_OPTION_ON 3 | |
3104 | |
3105 PNG_EXPORT(244, int, png_set_option, (png_structrp png_ptr, int option, | |
3106 int onoff)); | |
3107 #endif /* SET_OPTION */ | |
3108 | |
3109 /******************************************************************************* | |
3110 * END OF HARDWARE AND SOFTWARE OPTIONS | |
3111 ******************************************************************************/ | |
3112 | |
3113 /* Maintainer: Put new public prototypes here ^, in libpng.3, in project | |
3114 * defs, and in scripts/symbols.def. | |
3115 */ | |
3116 | |
3117 /* The last ordinal number (this is the *last* one already used; the next | |
3118 * one to use is one more than this.) | |
3119 */ | |
3120 #ifdef PNG_EXPORT_LAST_ORDINAL | |
3121 PNG_EXPORT_LAST_ORDINAL(244); | |
3122 #endif | |
3123 | |
3124 #ifdef __cplusplus | |
3125 } | |
3126 #endif | |
3127 | |
3128 #endif /* PNG_VERSION_INFO_ONLY */ | |
3129 /* Do not put anything past this line */ | |
3130 #endif /* PNG_H */ | |
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