1
2/* png.h - header file for PNG reference library
3 *
4 * libpng version 1.6.25, September 1, 2016
5 *
6 * Copyright (c) 1998-2002,2004,2006-2016 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 1.6.25, September 1, 2016:
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 * Some files in the "contrib" directory and some configure-generated
29 * files that are distributed with libpng have other copyright owners and
30 * are released under other open source licenses.
31 *
32 * libpng versions 1.0.7, July 1, 2000 through 1.6.25, September 1, 2016 are
33 * Copyright (c) 2000-2002, 2004, 2006-2016 Glenn Randers-Pehrson, are
34 * derived from libpng-1.0.6, and are distributed according to the same
35 * disclaimer and license as libpng-1.0.6 with the following individuals
36 * added to the list of Contributing Authors:
37 *
38 * Simon-Pierre Cadieux
39 * Eric S. Raymond
40 * Mans Rullgard
41 * Cosmin Truta
42 * Gilles Vollant
43 * James Yu
44 * Mandar Sahastrabuddhe
45 *
46 * and with the following additions to the disclaimer:
47 *
48 * There is no warranty against interference with your enjoyment of the
49 * library or against infringement. There is no warranty that our
50 * efforts or the library will fulfill any of your particular purposes
51 * or needs. This library is provided with all faults, and the entire
52 * risk of satisfactory quality, performance, accuracy, and effort is with
53 * the user.
54 *
55 * Some files in the "contrib" directory have other copyright owners and
56 * are released under other open source licenses.
57 *
58 *
59 * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
60 * Copyright (c) 1998-2000 Glenn Randers-Pehrson, are derived from
61 * libpng-0.96, and are distributed according to the same disclaimer and
62 * license as libpng-0.96, with the following individuals added to the list
63 * of Contributing Authors:
64 *
65 * Tom Lane
66 * Glenn Randers-Pehrson
67 * Willem van Schaik
68 *
69 * Some files in the "scripts" directory have different copyright owners
70 * but are also released under this license.
71 *
72 * libpng versions 0.89, June 1996, through 0.96, May 1997, are
73 * Copyright (c) 1996-1997 Andreas Dilger, are derived from libpng-0.88,
74 * and are distributed according to the same disclaimer and license as
75 * libpng-0.88, with the following individuals added to the list of
76 * Contributing Authors:
77 *
78 * John Bowler
79 * Kevin Bracey
80 * Sam Bushell
81 * Magnus Holmgren
82 * Greg Roelofs
83 * Tom Tanner
84 *
85 * Some files in the "scripts" directory have other copyright owners
86 * but are released under this license.
87 *
88 * libpng versions 0.5, May 1995, through 0.88, January 1996, are
89 * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
90 *
91 * For the purposes of this copyright and license, "Contributing Authors"
92 * is defined as the following set of individuals:
93 *
94 * Andreas Dilger
95 * Dave Martindale
96 * Guy Eric Schalnat
97 * Paul Schmidt
98 * Tim Wegner
99 *
100 * The PNG Reference Library is supplied "AS IS". The Contributing Authors
101 * and Group 42, Inc. disclaim all warranties, expressed or implied,
102 * including, without limitation, the warranties of merchantability and of
103 * fitness for any purpose. The Contributing Authors and Group 42, Inc.
104 * assume no liability for direct, indirect, incidental, special, exemplary,
105 * or consequential damages, which may result from the use of the PNG
106 * Reference Library, even if advised of the possibility of such damage.
107 *
108 * Permission is hereby granted to use, copy, modify, and distribute this
109 * source code, or portions hereof, for any purpose, without fee, subject
110 * to the following restrictions:
111 *
112 * 1. The origin of this source code must not be misrepresented.
113 *
114 * 2. Altered versions must be plainly marked as such and must not
115 * be misrepresented as being the original source.
116 *
117 * 3. This Copyright notice may not be removed or altered from any
118 * source or altered source distribution.
119 *
120 * The Contributing Authors and Group 42, Inc. specifically permit, without
121 * fee, and encourage the use of this source code as a component to
122 * supporting the PNG file format in commercial products. If you use this
123 * source code in a product, acknowledgment is not required but would be
124 * appreciated.
125 *
126 * END OF COPYRIGHT NOTICE, DISCLAIMER, and LICENSE.
127 *
128 * TRADEMARK:
129 *
130 * The name "libpng" has not been registered by the Copyright owner
131 * as a trademark in any jurisdiction. However, because libpng has
132 * been distributed and maintained world-wide, continually since 1995,
133 * the Copyright owner claims "common-law trademark protection" in any
134 * jurisdiction where common-law trademark is recognized.
135 *
136 * OSI CERTIFICATION:
137 *
138 * Libpng is OSI Certified Open Source Software. OSI Certified Open Source is
139 * a certification mark of the Open Source Initiative. OSI has not addressed
140 * the additional disclaimers inserted at version 1.0.7.
141 *
142 * EXPORT CONTROL:
143 *
144 * The Copyright owner believes that the Export Control Classification
145 * Number (ECCN) for libpng is EAR99, which means not subject to export
146 * controls or International Traffic in Arms Regulations (ITAR) because
147 * it is open source, publicly available software, that does not contain
148 * any encryption software. See the EAR, paragraphs 734.3(b)(3) and
149 * 734.7(b).
150 */
151
152/*
153 * A "png_get_copyright" function is available, for convenient use in "about"
154 * boxes and the like:
155 *
156 * printf("%s", png_get_copyright(NULL));
157 *
158 * Also, the PNG logo (in PNG format, of course) is supplied in the
159 * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
160 */
161
162/*
163 * The contributing authors would like to thank all those who helped
164 * with testing, bug fixes, and patience. This wouldn't have been
165 * possible without all of you.
166 *
167 * Thanks to Frank J. T. Wojcik for helping with the documentation.
168 */
169
170/* Note about libpng version numbers:
171 *
172 * Due to various miscommunications, unforeseen code incompatibilities
173 * and occasional factors outside the authors' control, version numbering
174 * on the library has not always been consistent and straightforward.
175 * The following table summarizes matters since version 0.89c, which was
176 * the first widely used release:
177 *
178 * source png.h png.h shared-lib
179 * version string int version
180 * ------- ------ ----- ----------
181 * 0.89c "1.0 beta 3" 0.89 89 1.0.89
182 * 0.90 "1.0 beta 4" 0.90 90 0.90 [should have been 2.0.90]
183 * 0.95 "1.0 beta 5" 0.95 95 0.95 [should have been 2.0.95]
184 * 0.96 "1.0 beta 6" 0.96 96 0.96 [should have been 2.0.96]
185 * 0.97b "1.00.97 beta 7" 1.00.97 97 1.0.1 [should have been 2.0.97]
186 * 0.97c 0.97 97 2.0.97
187 * 0.98 0.98 98 2.0.98
188 * 0.99 0.99 98 2.0.99
189 * 0.99a-m 0.99 99 2.0.99
190 * 1.00 1.00 100 2.1.0 [100 should be 10000]
191 * 1.0.0 (from here on, the 100 2.1.0 [100 should be 10000]
192 * 1.0.1 png.h string is 10001 2.1.0
193 * 1.0.1a-e identical to the 10002 from here on, the shared library
194 * 1.0.2 source version) 10002 is 2.V where V is the source code
195 * 1.0.2a-b 10003 version, except as noted.
196 * 1.0.3 10003
197 * 1.0.3a-d 10004
198 * 1.0.4 10004
199 * 1.0.4a-f 10005
200 * 1.0.5 (+ 2 patches) 10005
201 * 1.0.5a-d 10006
202 * 1.0.5e-r 10100 (not source compatible)
203 * 1.0.5s-v 10006 (not binary compatible)
204 * 1.0.6 (+ 3 patches) 10006 (still binary incompatible)
205 * 1.0.6d-f 10007 (still binary incompatible)
206 * 1.0.6g 10007
207 * 1.0.6h 10007 10.6h (testing xy.z so-numbering)
208 * 1.0.6i 10007 10.6i
209 * 1.0.6j 10007 2.1.0.6j (incompatible with 1.0.0)
210 * 1.0.7beta11-14 DLLNUM 10007 2.1.0.7beta11-14 (binary compatible)
211 * 1.0.7beta15-18 1 10007 2.1.0.7beta15-18 (binary compatible)
212 * 1.0.7rc1-2 1 10007 2.1.0.7rc1-2 (binary compatible)
213 * 1.0.7 1 10007 (still compatible)
214 * ...
215 * 1.0.19 10 10019 10.so.0.19[.0]
216 * ...
217 * 1.2.56 13 10256 12.so.0.56[.0]
218 * ...
219 * 1.5.27 15 10527 15.so.15.27[.0]
220 * ...
221 * 1.6.25 16 10625 16.so.16.25[.0]
222 *
223 * Henceforth the source version will match the shared-library major
224 * and minor numbers; the shared-library major version number will be
225 * used for changes in backward compatibility, as it is intended. The
226 * PNG_LIBPNG_VER macro, which is not used within libpng but is available
227 * for applications, is an unsigned integer of the form xyyzz corresponding
228 * to the source version x.y.z (leading zeros in y and z). Beta versions
229 * were given the previous public release number plus a letter, until
230 * version 1.0.6j; from then on they were given the upcoming public
231 * release number plus "betaNN" or "rcNN".
232 *
233 * Binary incompatibility exists only when applications make direct access
234 * to the info_ptr or png_ptr members through png.h, and the compiled
235 * application is loaded with a different version of the library.
236 *
237 * DLLNUM will change each time there are forward or backward changes
238 * in binary compatibility (e.g., when a new feature is added).
239 *
240 * See libpng.txt or libpng.3 for more information. The PNG specification
241 * is available as a W3C Recommendation and as an ISO Specification,
242 * <http://www.w3.org/TR/2003/REC-PNG-20031110/
243 */
244
245/*
246 * Y2K compliance in libpng:
247 * =========================
248 *
249 * September 1, 2016
250 *
251 * Since the PNG Development group is an ad-hoc body, we can't make
252 * an official declaration.
253 *
254 * This is your unofficial assurance that libpng from version 0.71 and
255 * upward through 1.6.25 are Y2K compliant. It is my belief that
256 * earlier versions were also Y2K compliant.
257 *
258 * Libpng only has two year fields. One is a 2-byte unsigned integer
259 * that will hold years up to 65535. The other, which is deprecated,
260 * holds the date in text format, and will hold years up to 9999.
261 *
262 * The integer is
263 * "png_uint_16 year" in png_time_struct.
264 *
265 * The string is
266 * "char time_buffer[29]" in png_struct. This is no longer used
267 * in libpng-1.6.x and will be removed from libpng-1.7.0.
268 *
269 * There are seven time-related functions:
270 * png.c: png_convert_to_rfc_1123_buffer() in png.c
271 * (formerly png_convert_to_rfc_1123() prior to libpng-1.5.x and
272 * png_convert_to_rfc_1152() in error prior to libpng-0.98)
273 * png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
274 * png_convert_from_time_t() in pngwrite.c
275 * png_get_tIME() in pngget.c
276 * png_handle_tIME() in pngrutil.c, called in pngread.c
277 * png_set_tIME() in pngset.c
278 * png_write_tIME() in pngwutil.c, called in pngwrite.c
279 *
280 * All handle dates properly in a Y2K environment. The
281 * png_convert_from_time_t() function calls gmtime() to convert from system
282 * clock time, which returns (year - 1900), which we properly convert to
283 * the full 4-digit year. There is a possibility that libpng applications
284 * are not passing 4-digit years into the png_convert_to_rfc_1123_buffer()
285 * function, or that they are incorrectly passing only a 2-digit year
286 * instead of "year - 1900" into the png_convert_from_struct_tm() function,
287 * but this is not under our control. The libpng documentation has always
288 * stated that it works with 4-digit years, and the APIs have been
289 * documented as such.
290 *
291 * The tIME chunk itself is also Y2K compliant. It uses a 2-byte unsigned
292 * integer to hold the year, and can hold years as large as 65535.
293 *
294 * zlib, upon which libpng depends, is also Y2K compliant. It contains
295 * no date-related code.
296 *
297 * Glenn Randers-Pehrson
298 * libpng maintainer
299 * PNG Development Group
300 */
301
302#ifndef PNG_H
303#define PNG_H
304
305/* This is not the place to learn how to use libpng. The file libpng-manual.txt
306 * describes how to use libpng, and the file example.c summarizes it
307 * with some code on which to build. This file is useful for looking
308 * at the actual function definitions and structure components. If that
309 * file has been stripped from your copy of libpng, you can find it at
310 * <http://www.libpng.org/pub/png/libpng-manual.txt>
311 *
312 * If you just need to read a PNG file and don't want to read the documentation
313 * skip to the end of this file and read the section entitled 'simplified API'.
314 */
315
316/* Version information for png.h - this should match the version in png.c */
317#define PNG_LIBPNG_VER_STRING "1.6.25"
318#define PNG_HEADER_VERSION_STRING " libpng version 1.6.25 - September 1, 2016\n"
319
320#define PNG_LIBPNG_VER_SONUM 16
321#define PNG_LIBPNG_VER_DLLNUM 16
322
323/* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
324#define PNG_LIBPNG_VER_MAJOR 1
325#define PNG_LIBPNG_VER_MINOR 6
326#define PNG_LIBPNG_VER_RELEASE 25
327
328/* This should match the numeric part of the final component of
329 * PNG_LIBPNG_VER_STRING, omitting any leading zero:
330 */
331
332#define PNG_LIBPNG_VER_BUILD 0
333
334/* Release Status */
335#define PNG_LIBPNG_BUILD_ALPHA 1
336#define PNG_LIBPNG_BUILD_BETA 2
337#define PNG_LIBPNG_BUILD_RC 3
338#define PNG_LIBPNG_BUILD_STABLE 4
339#define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7
340
341/* Release-Specific Flags */
342#define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with
343 PNG_LIBPNG_BUILD_STABLE only */
344#define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with
345 PNG_LIBPNG_BUILD_SPECIAL */
346#define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with
347 PNG_LIBPNG_BUILD_PRIVATE */
348
349#define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE
350
351/* Careful here. At one time, Guy wanted to use 082, but that would be octal.
352 * We must not include leading zeros.
353 * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only
354 * version 1.0.0 was mis-numbered 100 instead of 10000). From
355 * version 1.0.1 it's xxyyzz, where x=major, y=minor, z=release
356 */
357#define PNG_LIBPNG_VER 10625 /* 1.6.25 */
358
359/* Library configuration: these options cannot be changed after
360 * the library has been built.
361 */
362#ifndef PNGLCONF_H
363/* If pnglibconf.h is missing, you can
364 * copy scripts/pnglibconf.h.prebuilt to pnglibconf.h
365 */
366# include "pnglibconf.h"
367#endif
368
369#define PNG_APNG_SUPPORTED
370#define PNG_READ_APNG_SUPPORTED
371#define PNG_WRITE_APNG_SUPPORTED
372
373#ifndef PNG_VERSION_INFO_ONLY
374/* Machine specific configuration. */
375# include "pngconf.h"
376#endif
377
378/*
379 * Added at libpng-1.2.8
380 *
381 * Ref MSDN: Private as priority over Special
382 * VS_FF_PRIVATEBUILD File *was not* built using standard release
383 * procedures. If this value is given, the StringFileInfo block must
384 * contain a PrivateBuild string.
385 *
386 * VS_FF_SPECIALBUILD File *was* built by the original company using
387 * standard release procedures but is a variation of the standard
388 * file of the same version number. If this value is given, the
389 * StringFileInfo block must contain a SpecialBuild string.
390 */
391
392#ifdef PNG_USER_PRIVATEBUILD /* From pnglibconf.h */
393# define PNG_LIBPNG_BUILD_TYPE \
394 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE)
395#else
396# ifdef PNG_LIBPNG_SPECIALBUILD
397# define PNG_LIBPNG_BUILD_TYPE \
398 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL)
399# else
400# define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE)
401# endif
402#endif
403
404#ifndef PNG_VERSION_INFO_ONLY
405
406/* Inhibit C++ name-mangling for libpng functions but not for system calls. */
407#ifdef __cplusplus
408extern "C" {
409#endif /* __cplusplus */
410
411/* Version information for C files, stored in png.c. This had better match
412 * the version above.
413 */
414#define png_libpng_ver png_get_header_ver(NULL)
415
416/* This file is arranged in several sections:
417 *
418 * 1. [omitted]
419 * 2. Any configuration options that can be specified by for the application
420 * code when it is built. (Build time configuration is in pnglibconf.h)
421 * 3. Type definitions (base types are defined in pngconf.h), structure
422 * definitions.
423 * 4. Exported library functions.
424 * 5. Simplified API.
425 * 6. Implementation options.
426 *
427 * The library source code has additional files (principally pngpriv.h) that
428 * allow configuration of the library.
429 */
430
431/* Section 1: [omitted] */
432
433/* Section 2: run time configuration
434 * See pnglibconf.h for build time configuration
435 *
436 * Run time configuration allows the application to choose between
437 * implementations of certain arithmetic APIs. The default is set
438 * at build time and recorded in pnglibconf.h, but it is safe to
439 * override these (and only these) settings. Note that this won't
440 * change what the library does, only application code, and the
441 * settings can (and probably should) be made on a per-file basis
442 * by setting the #defines before including png.h
443 *
444 * Use macros to read integers from PNG data or use the exported
445 * functions?
446 * PNG_USE_READ_MACROS: use the macros (see below) Note that
447 * the macros evaluate their argument multiple times.
448 * PNG_NO_USE_READ_MACROS: call the relevant library function.
449 *
450 * Use the alternative algorithm for compositing alpha samples that
451 * does not use division?
452 * PNG_READ_COMPOSITE_NODIV_SUPPORTED: use the 'no division'
453 * algorithm.
454 * PNG_NO_READ_COMPOSITE_NODIV: use the 'division' algorithm.
455 *
456 * How to handle benign errors if PNG_ALLOW_BENIGN_ERRORS is
457 * false?
458 * PNG_ALLOW_BENIGN_ERRORS: map calls to the benign error
459 * APIs to png_warning.
460 * Otherwise the calls are mapped to png_error.
461 */
462
463/* Section 3: type definitions, including structures and compile time
464 * constants.
465 * See pngconf.h for base types that vary by machine/system
466 */
467
468#ifdef PNG_APNG_SUPPORTED
469/* dispose_op flags from inside fcTL */
470#define PNG_DISPOSE_OP_NONE 0x00
471#define PNG_DISPOSE_OP_BACKGROUND 0x01
472#define PNG_DISPOSE_OP_PREVIOUS 0x02
473
474/* blend_op flags from inside fcTL */
475#define PNG_BLEND_OP_SOURCE 0x00
476#define PNG_BLEND_OP_OVER 0x01
477#endif /* PNG_APNG_SUPPORTED */
478
479/* This triggers a compiler error in png.c, if png.c and png.h
480 * do not agree upon the version number.
481 */
482typedef char* png_libpng_version_1_6_25;
483
484/* Basic control structions. Read libpng-manual.txt or libpng.3 for more info.
485 *
486 * png_struct is the cache of information used while reading or writing a single
487 * PNG file. One of these is always required, although the simplified API
488 * (below) hides the creation and destruction of it.
489 */
490typedef struct png_struct_def png_struct;
491typedef const png_struct * png_const_structp;
492typedef png_struct * png_structp;
493typedef png_struct * * png_structpp;
494
495/* png_info contains information read from or to be written to a PNG file. One
496 * or more of these must exist while reading or creating a PNG file. The
497 * information is not used by libpng during read but is used to control what
498 * gets written when a PNG file is created. "png_get_" function calls read
499 * information during read and "png_set_" functions calls write information
500 * when creating a PNG.
501 * been moved into a separate header file that is not accessible to
502 * applications. Read libpng-manual.txt or libpng.3 for more info.
503 */
504typedef struct png_info_def png_info;
505typedef png_info * png_infop;
506typedef const png_info * png_const_infop;
507typedef png_info * * png_infopp;
508
509/* Types with names ending 'p' are pointer types. The corresponding types with
510 * names ending 'rp' are identical pointer types except that the pointer is
511 * marked 'restrict', which means that it is the only pointer to the object
512 * passed to the function. Applications should not use the 'restrict' types;
513 * it is always valid to pass 'p' to a pointer with a function argument of the
514 * corresponding 'rp' type. Different compilers have different rules with
515 * regard to type matching in the presence of 'restrict'. For backward
516 * compatibility libpng callbacks never have 'restrict' in their parameters and,
517 * consequentially, writing portable application code is extremely difficult if
518 * an attempt is made to use 'restrict'.
519 */
520typedef png_struct * PNG_RESTRICT png_structrp;
521typedef const png_struct * PNG_RESTRICT png_const_structrp;
522typedef png_info * PNG_RESTRICT png_inforp;
523typedef const png_info * PNG_RESTRICT png_const_inforp;
524
525/* Three color definitions. The order of the red, green, and blue, (and the
526 * exact size) is not important, although the size of the fields need to
527 * be png_byte or png_uint_16 (as defined below).
528 */
529typedef struct png_color_struct
530{
531 png_byte red;
532 png_byte green;
533 png_byte blue;
534} png_color;
535typedef png_color * png_colorp;
536typedef const png_color * png_const_colorp;
537typedef png_color * * png_colorpp;
538
539typedef struct png_color_16_struct
540{
541 png_byte index; /* used for palette files */
542 png_uint_16 red; /* for use in red green blue files */
543 png_uint_16 green;
544 png_uint_16 blue;
545 png_uint_16 gray; /* for use in grayscale files */
546} png_color_16;
547typedef png_color_16 * png_color_16p;
548typedef const png_color_16 * png_const_color_16p;
549typedef png_color_16 * * png_color_16pp;
550
551typedef struct png_color_8_struct
552{
553 png_byte red; /* for use in red green blue files */
554 png_byte green;
555 png_byte blue;
556 png_byte gray; /* for use in grayscale files */
557 png_byte alpha; /* for alpha channel files */
558} png_color_8;
559typedef png_color_8 * png_color_8p;
560typedef const png_color_8 * png_const_color_8p;
561typedef png_color_8 * * png_color_8pp;
562
563/*
564 * The following two structures are used for the in-core representation
565 * of sPLT chunks.
566 */
567typedef struct png_sPLT_entry_struct
568{
569 png_uint_16 red;
570 png_uint_16 green;
571 png_uint_16 blue;
572 png_uint_16 alpha;
573 png_uint_16 frequency;
574} png_sPLT_entry;
575typedef png_sPLT_entry * png_sPLT_entryp;
576typedef const png_sPLT_entry * png_const_sPLT_entryp;
577typedef png_sPLT_entry * * png_sPLT_entrypp;
578
579/* When the depth of the sPLT palette is 8 bits, the color and alpha samples
580 * occupy the LSB of their respective members, and the MSB of each member
581 * is zero-filled. The frequency member always occupies the full 16 bits.
582 */
583
584typedef struct png_sPLT_struct
585{
586 png_charp name; /* palette name */
587 png_byte depth; /* depth of palette samples */
588 png_sPLT_entryp entries; /* palette entries */
589 png_int_32 nentries; /* number of palette entries */
590} png_sPLT_t;
591typedef png_sPLT_t * png_sPLT_tp;
592typedef const png_sPLT_t * png_const_sPLT_tp;
593typedef png_sPLT_t * * png_sPLT_tpp;
594
595#ifdef PNG_TEXT_SUPPORTED
596/* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,
597 * and whether that contents is compressed or not. The "key" field
598 * points to a regular zero-terminated C string. The "text" fields can be a
599 * regular C string, an empty string, or a NULL pointer.
600 * However, the structure returned by png_get_text() will always contain
601 * the "text" field as a regular zero-terminated C string (possibly
602 * empty), never a NULL pointer, so it can be safely used in printf() and
603 * other string-handling functions. Note that the "itxt_length", "lang", and
604 * "lang_key" members of the structure only exist when the library is built
605 * with iTXt chunk support. Prior to libpng-1.4.0 the library was built by
606 * default without iTXt support. Also note that when iTXt *is* supported,
607 * the "lang" and "lang_key" fields contain NULL pointers when the
608 * "compression" field contains * PNG_TEXT_COMPRESSION_NONE or
609 * PNG_TEXT_COMPRESSION_zTXt. Note that the "compression value" is not the
610 * same as what appears in the PNG tEXt/zTXt/iTXt chunk's "compression flag"
611 * which is always 0 or 1, or its "compression method" which is always 0.
612 */
613typedef struct png_text_struct
614{
615 int compression; /* compression value:
616 -1: tEXt, none
617 0: zTXt, deflate
618 1: iTXt, none
619 2: iTXt, deflate */
620 png_charp key; /* keyword, 1-79 character description of "text" */
621 png_charp text; /* comment, may be an empty string (ie "")
622 or a NULL pointer */
623 png_size_t text_length; /* length of the text string */
624 png_size_t itxt_length; /* length of the itxt string */
625 png_charp lang; /* language code, 0-79 characters
626 or a NULL pointer */
627 png_charp lang_key; /* keyword translated UTF-8 string, 0 or more
628 chars or a NULL pointer */
629} png_text;
630typedef png_text * png_textp;
631typedef const png_text * png_const_textp;
632typedef png_text * * png_textpp;
633#endif
634
635/* Supported compression types for text in PNG files (tEXt, and zTXt).
636 * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */
637#define PNG_TEXT_COMPRESSION_NONE_WR -3
638#define PNG_TEXT_COMPRESSION_zTXt_WR -2
639#define PNG_TEXT_COMPRESSION_NONE -1
640#define PNG_TEXT_COMPRESSION_zTXt 0
641#define PNG_ITXT_COMPRESSION_NONE 1
642#define PNG_ITXT_COMPRESSION_zTXt 2
643#define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */
644
645/* png_time is a way to hold the time in an machine independent way.
646 * Two conversions are provided, both from time_t and struct tm. There
647 * is no portable way to convert to either of these structures, as far
648 * as I know. If you know of a portable way, send it to me. As a side
649 * note - PNG has always been Year 2000 compliant!
650 */
651typedef struct png_time_struct
652{
653 png_uint_16 year; /* full year, as in, 1995 */
654 png_byte month; /* month of year, 1 - 12 */
655 png_byte day; /* day of month, 1 - 31 */
656 png_byte hour; /* hour of day, 0 - 23 */
657 png_byte minute; /* minute of hour, 0 - 59 */
658 png_byte second; /* second of minute, 0 - 60 (for leap seconds) */
659} png_time;
660typedef png_time * png_timep;
661typedef const png_time * png_const_timep;
662typedef png_time * * png_timepp;
663
664#if defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) ||\
665 defined(PNG_USER_CHUNKS_SUPPORTED)
666/* png_unknown_chunk is a structure to hold queued chunks for which there is
667 * no specific support. The idea is that we can use this to queue
668 * up private chunks for output even though the library doesn't actually
669 * know about their semantics.
670 *
671 * The data in the structure is set by libpng on read and used on write.
672 */
673typedef struct png_unknown_chunk_t
674{
675 png_byte name[5]; /* Textual chunk name with '\0' terminator */
676 png_byte *data; /* Data, should not be modified on read! */
677 png_size_t size;
678
679 /* On write 'location' must be set using the flag values listed below.
680 * Notice that on read it is set by libpng however the values stored have
681 * more bits set than are listed below. Always treat the value as a
682 * bitmask. On write set only one bit - setting multiple bits may cause the
683 * chunk to be written in multiple places.
684 */
685 png_byte location; /* mode of operation at read time */
686}
687png_unknown_chunk;
688
689typedef png_unknown_chunk * png_unknown_chunkp;
690typedef const png_unknown_chunk * png_const_unknown_chunkp;
691typedef png_unknown_chunk * * png_unknown_chunkpp;
692#endif
693
694/* Flag values for the unknown chunk location byte. */
695#define PNG_HAVE_IHDR 0x01
696#define PNG_HAVE_PLTE 0x02
697#define PNG_AFTER_IDAT 0x08
698
699/* Maximum positive integer used in PNG is (2^31)-1 */
700#define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL)
701#define PNG_UINT_32_MAX ((png_uint_32)(-1))
702#define PNG_SIZE_MAX ((png_size_t)(-1))
703
704/* These are constants for fixed point values encoded in the
705 * PNG specification manner (x100000)
706 */
707#define PNG_FP_1 100000
708#define PNG_FP_HALF 50000
709#define PNG_FP_MAX ((png_fixed_point)0x7fffffffL)
710#define PNG_FP_MIN (-PNG_FP_MAX)
711
712/* These describe the color_type field in png_info. */
713/* color type masks */
714#define PNG_COLOR_MASK_PALETTE 1
715#define PNG_COLOR_MASK_COLOR 2
716#define PNG_COLOR_MASK_ALPHA 4
717
718/* color types. Note that not all combinations are legal */
719#define PNG_COLOR_TYPE_GRAY 0
720#define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
721#define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR)
722#define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
723#define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
724/* aliases */
725#define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA
726#define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA
727
728/* This is for compression type. PNG 1.0-1.2 only define the single type. */
729#define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */
730#define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE
731
732/* This is for filter type. PNG 1.0-1.2 only define the single type. */
733#define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */
734#define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */
735#define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE
736
737/* These are for the interlacing type. These values should NOT be changed. */
738#define PNG_INTERLACE_NONE 0 /* Non-interlaced image */
739#define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */
740#define PNG_INTERLACE_LAST 2 /* Not a valid value */
741
742/* These are for the oFFs chunk. These values should NOT be changed. */
743#define PNG_OFFSET_PIXEL 0 /* Offset in pixels */
744#define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */
745#define PNG_OFFSET_LAST 2 /* Not a valid value */
746
747/* These are for the pCAL chunk. These values should NOT be changed. */
748#define PNG_EQUATION_LINEAR 0 /* Linear transformation */
749#define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */
750#define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */
751#define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */
752#define PNG_EQUATION_LAST 4 /* Not a valid value */
753
754/* These are for the sCAL chunk. These values should NOT be changed. */
755#define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */
756#define PNG_SCALE_METER 1 /* meters per pixel */
757#define PNG_SCALE_RADIAN 2 /* radians per pixel */
758#define PNG_SCALE_LAST 3 /* Not a valid value */
759
760/* These are for the pHYs chunk. These values should NOT be changed. */
761#define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */
762#define PNG_RESOLUTION_METER 1 /* pixels/meter */
763#define PNG_RESOLUTION_LAST 2 /* Not a valid value */
764
765/* These are for the sRGB chunk. These values should NOT be changed. */
766#define PNG_sRGB_INTENT_PERCEPTUAL 0
767#define PNG_sRGB_INTENT_RELATIVE 1
768#define PNG_sRGB_INTENT_SATURATION 2
769#define PNG_sRGB_INTENT_ABSOLUTE 3
770#define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */
771
772/* This is for text chunks */
773#define PNG_KEYWORD_MAX_LENGTH 79
774
775/* Maximum number of entries in PLTE/sPLT/tRNS arrays */
776#define PNG_MAX_PALETTE_LENGTH 256
777
778/* These determine if an ancillary chunk's data has been successfully read
779 * from the PNG header, or if the application has filled in the corresponding
780 * data in the info_struct to be written into the output file. The values
781 * of the PNG_INFO_<chunk> defines should NOT be changed.
782 */
783#define PNG_INFO_gAMA 0x0001U
784#define PNG_INFO_sBIT 0x0002U
785#define PNG_INFO_cHRM 0x0004U
786#define PNG_INFO_PLTE 0x0008U
787#define PNG_INFO_tRNS 0x0010U
788#define PNG_INFO_bKGD 0x0020U
789#define PNG_INFO_hIST 0x0040U
790#define PNG_INFO_pHYs 0x0080U
791#define PNG_INFO_oFFs 0x0100U
792#define PNG_INFO_tIME 0x0200U
793#define PNG_INFO_pCAL 0x0400U
794#define PNG_INFO_sRGB 0x0800U /* GR-P, 0.96a */
795#define PNG_INFO_iCCP 0x1000U /* ESR, 1.0.6 */
796#define PNG_INFO_sPLT 0x2000U /* ESR, 1.0.6 */
797#define PNG_INFO_sCAL 0x4000U /* ESR, 1.0.6 */
798#define PNG_INFO_IDAT 0x8000U /* ESR, 1.0.6 */
799#ifdef PNG_APNG_SUPPORTED
800#define PNG_INFO_acTL 0x10000
801#define PNG_INFO_fcTL 0x20000
802#endif
803
804/* This is used for the transformation routines, as some of them
805 * change these values for the row. It also should enable using
806 * the routines for other purposes.
807 */
808typedef struct png_row_info_struct
809{
810 png_uint_32 width; /* width of row */
811 png_size_t rowbytes; /* number of bytes in row */
812 png_byte color_type; /* color type of row */
813 png_byte bit_depth; /* bit depth of row */
814 png_byte channels; /* number of channels (1, 2, 3, or 4) */
815 png_byte pixel_depth; /* bits per pixel (depth * channels) */
816} png_row_info;
817
818typedef png_row_info * png_row_infop;
819typedef png_row_info * * png_row_infopp;
820
821/* These are the function types for the I/O functions and for the functions
822 * that allow the user to override the default I/O functions with his or her
823 * own. The png_error_ptr type should match that of user-supplied warning
824 * and error functions, while the png_rw_ptr type should match that of the
825 * user read/write data functions. Note that the 'write' function must not
826 * modify the buffer it is passed. The 'read' function, on the other hand, is
827 * expected to return the read data in the buffer.
828 */
829typedef PNG_CALLBACK(void, *png_error_ptr, (png_structp, png_const_charp));
830typedef PNG_CALLBACK(void, *png_rw_ptr, (png_structp, png_bytep, png_size_t));
831typedef PNG_CALLBACK(void, *png_flush_ptr, (png_structp));
832typedef PNG_CALLBACK(void, *png_read_status_ptr, (png_structp, png_uint_32,
833 int));
834typedef PNG_CALLBACK(void, *png_write_status_ptr, (png_structp, png_uint_32,
835 int));
836
837#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
838typedef PNG_CALLBACK(void, *png_progressive_info_ptr, (png_structp, png_infop));
839typedef PNG_CALLBACK(void, *png_progressive_end_ptr, (png_structp, png_infop));
840#ifdef PNG_APNG_SUPPORTED
841typedef PNG_CALLBACK(void, *png_progressive_frame_ptr, (png_structp,
842 png_uint_32));
843#endif
844
845/* The following callback receives png_uint_32 row_number, int pass for the
846 * png_bytep data of the row. When transforming an interlaced image the
847 * row number is the row number within the sub-image of the interlace pass, so
848 * the value will increase to the height of the sub-image (not the full image)
849 * then reset to 0 for the next pass.
850 *
851 * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
852 * find the output pixel (x,y) given an interlaced sub-image pixel
853 * (row,col,pass). (See below for these macros.)
854 */
855typedef PNG_CALLBACK(void, *png_progressive_row_ptr, (png_structp, png_bytep,
856 png_uint_32, int));
857#endif
858
859#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
860 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
861typedef PNG_CALLBACK(void, *png_user_transform_ptr, (png_structp, png_row_infop,
862 png_bytep));
863#endif
864
865#ifdef PNG_USER_CHUNKS_SUPPORTED
866typedef PNG_CALLBACK(int, *png_user_chunk_ptr, (png_structp,
867 png_unknown_chunkp));
868#endif
869#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
870/* not used anywhere */
871/* typedef PNG_CALLBACK(void, *png_unknown_chunk_ptr, (png_structp)); */
872#endif
873
874#ifdef PNG_SETJMP_SUPPORTED
875/* This must match the function definition in <setjmp.h>, and the application
876 * must include this before png.h to obtain the definition of jmp_buf. The
877 * function is required to be PNG_NORETURN, but this is not checked. If the
878 * function does return the application will crash via an abort() or similar
879 * system level call.
880 *
881 * If you get a warning here while building the library you may need to make
882 * changes to ensure that pnglibconf.h records the calling convention used by
883 * your compiler. This may be very difficult - try using a different compiler
884 * to build the library!
885 */
886PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)), typedef);
887#endif
888
889/* Transform masks for the high-level interface */
890#define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */
891#define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */
892#define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */
893#define PNG_TRANSFORM_PACKING 0x0004 /* read and write */
894#define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */
895#define PNG_TRANSFORM_EXPAND 0x0010 /* read only */
896#define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */
897#define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */
898#define PNG_TRANSFORM_BGR 0x0080 /* read and write */
899#define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */
900#define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */
901#define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */
902#define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* write only */
903/* Added to libpng-1.2.34 */
904#define PNG_TRANSFORM_STRIP_FILLER_BEFORE PNG_TRANSFORM_STRIP_FILLER
905#define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */
906/* Added to libpng-1.4.0 */
907#define PNG_TRANSFORM_GRAY_TO_RGB 0x2000 /* read only */
908/* Added to libpng-1.5.4 */
909#define PNG_TRANSFORM_EXPAND_16 0x4000 /* read only */
910#if INT_MAX >= 0x8000 /* else this might break */
911#define PNG_TRANSFORM_SCALE_16 0x8000 /* read only */
912#endif
913
914/* Flags for MNG supported features */
915#define PNG_FLAG_MNG_EMPTY_PLTE 0x01
916#define PNG_FLAG_MNG_FILTER_64 0x04
917#define PNG_ALL_MNG_FEATURES 0x05
918
919/* NOTE: prior to 1.5 these functions had no 'API' style declaration,
920 * this allowed the zlib default functions to be used on Windows
921 * platforms. In 1.5 the zlib default malloc (which just calls malloc and
922 * ignores the first argument) should be completely compatible with the
923 * following.
924 */
925typedef PNG_CALLBACK(png_voidp, *png_malloc_ptr, (png_structp,
926 png_alloc_size_t));
927typedef PNG_CALLBACK(void, *png_free_ptr, (png_structp, png_voidp));
928
929/* Section 4: exported functions
930 * Here are the function definitions most commonly used. This is not
931 * the place to find out how to use libpng. See libpng-manual.txt for the
932 * full explanation, see example.c for the summary. This just provides
933 * a simple one line description of the use of each function.
934 *
935 * The PNG_EXPORT() and PNG_EXPORTA() macros used below are defined in
936 * pngconf.h and in the *.dfn files in the scripts directory.
937 *
938 * PNG_EXPORT(ordinal, type, name, (args));
939 *
940 * ordinal: ordinal that is used while building
941 * *.def files. The ordinal value is only
942 * relevant when preprocessing png.h with
943 * the *.dfn files for building symbol table
944 * entries, and are removed by pngconf.h.
945 * type: return type of the function
946 * name: function name
947 * args: function arguments, with types
948 *
949 * When we wish to append attributes to a function prototype we use
950 * the PNG_EXPORTA() macro instead.
951 *
952 * PNG_EXPORTA(ordinal, type, name, (args), attributes);
953 *
954 * ordinal, type, name, and args: same as in PNG_EXPORT().
955 * attributes: function attributes
956 */
957
958/* Returns the version number of the library */
959PNG_EXPORT(1, png_uint_32, png_access_version_number, (void));
960
961/* Tell lib we have already handled the first <num_bytes> magic bytes.
962 * Handling more than 8 bytes from the beginning of the file is an error.
963 */
964PNG_EXPORT(2, void, png_set_sig_bytes, (png_structrp png_ptr, int num_bytes));
965
966/* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
967 * PNG file. Returns zero if the supplied bytes match the 8-byte PNG
968 * signature, and non-zero otherwise. Having num_to_check == 0 or
969 * start > 7 will always fail (ie return non-zero).
970 */
971PNG_EXPORT(3, int, png_sig_cmp, (png_const_bytep sig, png_size_t start,
972 png_size_t num_to_check));
973
974/* Simple signature checking function. This is the same as calling
975 * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n).
976 */
977#define png_check_sig(sig, n) !png_sig_cmp((sig), 0, (n))
978
979/* Allocate and initialize png_ptr struct for reading, and any other memory. */
980PNG_EXPORTA(4, png_structp, png_create_read_struct,
981 (png_const_charp user_png_ver, png_voidp error_ptr,
982 png_error_ptr error_fn, png_error_ptr warn_fn),
983 PNG_ALLOCATED);
984
985/* Allocate and initialize png_ptr struct for writing, and any other memory */
986PNG_EXPORTA(5, png_structp, png_create_write_struct,
987 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
988 png_error_ptr warn_fn),
989 PNG_ALLOCATED);
990
991PNG_EXPORT(6, png_size_t, png_get_compression_buffer_size,
992 (png_const_structrp png_ptr));
993
994PNG_EXPORT(7, void, png_set_compression_buffer_size, (png_structrp png_ptr,
995 png_size_t size));
996
997/* Moved from pngconf.h in 1.4.0 and modified to ensure setjmp/longjmp
998 * match up.
999 */
1000#ifdef PNG_SETJMP_SUPPORTED
1001/* This function returns the jmp_buf built in to *png_ptr. It must be
1002 * supplied with an appropriate 'longjmp' function to use on that jmp_buf
1003 * unless the default error function is overridden in which case NULL is
1004 * acceptable. The size of the jmp_buf is checked against the actual size
1005 * allocated by the library - the call will return NULL on a mismatch
1006 * indicating an ABI mismatch.
1007 */
1008PNG_EXPORT(8, jmp_buf*, png_set_longjmp_fn, (png_structrp png_ptr,
1009 png_longjmp_ptr longjmp_fn, size_t jmp_buf_size));
1010# define png_jmpbuf(png_ptr) \
1011 (*png_set_longjmp_fn((png_ptr), longjmp, (sizeof (jmp_buf))))
1012#else
1013# define png_jmpbuf(png_ptr) \
1014 (LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP)
1015#endif
1016/* This function should be used by libpng applications in place of
1017 * longjmp(png_ptr->jmpbuf, val). If longjmp_fn() has been set, it
1018 * will use it; otherwise it will call PNG_ABORT(). This function was
1019 * added in libpng-1.5.0.
1020 */
1021PNG_EXPORTA(9, void, png_longjmp, (png_const_structrp png_ptr, int val),
1022 PNG_NORETURN);
1023
1024#ifdef PNG_READ_SUPPORTED
1025/* Reset the compression stream */
1026PNG_EXPORTA(10, int, png_reset_zstream, (png_structrp png_ptr), PNG_DEPRECATED);
1027#endif
1028
1029/* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */
1030#ifdef PNG_USER_MEM_SUPPORTED
1031PNG_EXPORTA(11, png_structp, png_create_read_struct_2,
1032 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
1033 png_error_ptr warn_fn,
1034 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn),
1035 PNG_ALLOCATED);
1036PNG_EXPORTA(12, png_structp, png_create_write_struct_2,
1037 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
1038 png_error_ptr warn_fn,
1039 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn),
1040 PNG_ALLOCATED);
1041#endif
1042
1043/* Write the PNG file signature. */
1044PNG_EXPORT(13, void, png_write_sig, (png_structrp png_ptr));
1045
1046/* Write a PNG chunk - size, type, (optional) data, CRC. */
1047PNG_EXPORT(14, void, png_write_chunk, (png_structrp png_ptr, png_const_bytep
1048 chunk_name, png_const_bytep data, png_size_t length));
1049
1050/* Write the start of a PNG chunk - length and chunk name. */
1051PNG_EXPORT(15, void, png_write_chunk_start, (png_structrp png_ptr,
1052 png_const_bytep chunk_name, png_uint_32 length));
1053
1054/* Write the data of a PNG chunk started with png_write_chunk_start(). */
1055PNG_EXPORT(16, void, png_write_chunk_data, (png_structrp png_ptr,
1056 png_const_bytep data, png_size_t length));
1057
1058/* Finish a chunk started with png_write_chunk_start() (includes CRC). */
1059PNG_EXPORT(17, void, png_write_chunk_end, (png_structrp png_ptr));
1060
1061/* Allocate and initialize the info structure */
1062PNG_EXPORTA(18, png_infop, png_create_info_struct, (png_const_structrp png_ptr),
1063 PNG_ALLOCATED);
1064
1065/* DEPRECATED: this function allowed init structures to be created using the
1066 * default allocation method (typically malloc). Use is deprecated in 1.6.0 and
1067 * the API will be removed in the future.
1068 */
1069PNG_EXPORTA(19, void, png_info_init_3, (png_infopp info_ptr,
1070 png_size_t png_info_struct_size), PNG_DEPRECATED);
1071
1072/* Writes all the PNG information before the image. */
1073PNG_EXPORT(20, void, png_write_info_before_PLTE,
1074 (png_structrp png_ptr, png_const_inforp info_ptr));
1075PNG_EXPORT(21, void, png_write_info,
1076 (png_structrp png_ptr, png_const_inforp info_ptr));
1077
1078#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1079/* Read the information before the actual image data. */
1080PNG_EXPORT(22, void, png_read_info,
1081 (png_structrp png_ptr, png_inforp info_ptr));
1082#endif
1083
1084#ifdef PNG_TIME_RFC1123_SUPPORTED
1085 /* Convert to a US string format: there is no localization support in this
1086 * routine. The original implementation used a 29 character buffer in
1087 * png_struct, this will be removed in future versions.
1088 */
1089#if PNG_LIBPNG_VER < 10700
1090/* To do: remove this from libpng17 (and from libpng17/png.c and pngstruct.h) */
1091PNG_EXPORTA(23, png_const_charp, png_convert_to_rfc1123, (png_structrp png_ptr,
1092 png_const_timep ptime),PNG_DEPRECATED);
1093#endif
1094PNG_EXPORT(241, int, png_convert_to_rfc1123_buffer, (char out[29],
1095 png_const_timep ptime));
1096#endif
1097
1098#ifdef PNG_CONVERT_tIME_SUPPORTED
1099/* Convert from a struct tm to png_time */
1100PNG_EXPORT(24, void, png_convert_from_struct_tm, (png_timep ptime,
1101 const struct tm * ttime));
1102
1103/* Convert from time_t to png_time. Uses gmtime() */
1104PNG_EXPORT(25, void, png_convert_from_time_t, (png_timep ptime, time_t ttime));
1105#endif /* CONVERT_tIME */
1106
1107#ifdef PNG_READ_EXPAND_SUPPORTED
1108/* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
1109PNG_EXPORT(26, void, png_set_expand, (png_structrp png_ptr));
1110PNG_EXPORT(27, void, png_set_expand_gray_1_2_4_to_8, (png_structrp png_ptr));
1111PNG_EXPORT(28, void, png_set_palette_to_rgb, (png_structrp png_ptr));
1112PNG_EXPORT(29, void, png_set_tRNS_to_alpha, (png_structrp png_ptr));
1113#endif
1114
1115#ifdef PNG_READ_EXPAND_16_SUPPORTED
1116/* Expand to 16-bit channels, forces conversion of palette to RGB and expansion
1117 * of a tRNS chunk if present.
1118 */
1119PNG_EXPORT(221, void, png_set_expand_16, (png_structrp png_ptr));
1120#endif
1121
1122#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
1123/* Use blue, green, red order for pixels. */
1124PNG_EXPORT(30, void, png_set_bgr, (png_structrp png_ptr));
1125#endif
1126
1127#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
1128/* Expand the grayscale to 24-bit RGB if necessary. */
1129PNG_EXPORT(31, void, png_set_gray_to_rgb, (png_structrp png_ptr));
1130#endif
1131
1132#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1133/* Reduce RGB to grayscale. */
1134#define PNG_ERROR_ACTION_NONE 1
1135#define PNG_ERROR_ACTION_WARN 2
1136#define PNG_ERROR_ACTION_ERROR 3
1137#define PNG_RGB_TO_GRAY_DEFAULT (-1)/*for red/green coefficients*/
1138
1139PNG_FP_EXPORT(32, void, png_set_rgb_to_gray, (png_structrp png_ptr,
1140 int error_action, double red, double green))
1141PNG_FIXED_EXPORT(33, void, png_set_rgb_to_gray_fixed, (png_structrp png_ptr,
1142 int error_action, png_fixed_point red, png_fixed_point green))
1143
1144PNG_EXPORT(34, png_byte, png_get_rgb_to_gray_status, (png_const_structrp
1145 png_ptr));
1146#endif
1147
1148#ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED
1149PNG_EXPORT(35, void, png_build_grayscale_palette, (int bit_depth,
1150 png_colorp palette));
1151#endif
1152
1153#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
1154/* How the alpha channel is interpreted - this affects how the color channels
1155 * of a PNG file are returned to the calling application when an alpha channel,
1156 * or a tRNS chunk in a palette file, is present.
1157 *
1158 * This has no effect on the way pixels are written into a PNG output
1159 * datastream. The color samples in a PNG datastream are never premultiplied
1160 * with the alpha samples.
1161 *
1162 * The default is to return data according to the PNG specification: the alpha
1163 * channel is a linear measure of the contribution of the pixel to the
1164 * corresponding composited pixel, and the color channels are unassociated
1165 * (not premultiplied). The gamma encoded color channels must be scaled
1166 * according to the contribution and to do this it is necessary to undo
1167 * the encoding, scale the color values, perform the composition and reencode
1168 * the values. This is the 'PNG' mode.
1169 *
1170 * The alternative is to 'associate' the alpha with the color information by
1171 * storing color channel values that have been scaled by the alpha.
1172 * image. These are the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' modes
1173 * (the latter being the two common names for associated alpha color channels).
1174 *
1175 * For the 'OPTIMIZED' mode, a pixel is treated as opaque only if the alpha
1176 * value is equal to the maximum value.
1177 *
1178 * The final choice is to gamma encode the alpha channel as well. This is
1179 * broken because, in practice, no implementation that uses this choice
1180 * correctly undoes the encoding before handling alpha composition. Use this
1181 * choice only if other serious errors in the software or hardware you use
1182 * mandate it; the typical serious error is for dark halos to appear around
1183 * opaque areas of the composited PNG image because of arithmetic overflow.
1184 *
1185 * The API function png_set_alpha_mode specifies which of these choices to use
1186 * with an enumerated 'mode' value and the gamma of the required output:
1187 */
1188#define PNG_ALPHA_PNG 0 /* according to the PNG standard */
1189#define PNG_ALPHA_STANDARD 1 /* according to Porter/Duff */
1190#define PNG_ALPHA_ASSOCIATED 1 /* as above; this is the normal practice */
1191#define PNG_ALPHA_PREMULTIPLIED 1 /* as above */
1192#define PNG_ALPHA_OPTIMIZED 2 /* 'PNG' for opaque pixels, else 'STANDARD' */
1193#define PNG_ALPHA_BROKEN 3 /* the alpha channel is gamma encoded */
1194
1195PNG_FP_EXPORT(227, void, png_set_alpha_mode, (png_structrp png_ptr, int mode,
1196 double output_gamma))
1197PNG_FIXED_EXPORT(228, void, png_set_alpha_mode_fixed, (png_structrp png_ptr,
1198 int mode, png_fixed_point output_gamma))
1199#endif
1200
1201#if defined(PNG_GAMMA_SUPPORTED) || defined(PNG_READ_ALPHA_MODE_SUPPORTED)
1202/* The output_gamma value is a screen gamma in libpng terminology: it expresses
1203 * how to decode the output values, not how they are encoded.
1204 */
1205#define PNG_DEFAULT_sRGB -1 /* sRGB gamma and color space */
1206#define PNG_GAMMA_MAC_18 -2 /* Old Mac '1.8' gamma and color space */
1207#define PNG_GAMMA_sRGB 220000 /* Television standards--matches sRGB gamma */
1208#define PNG_GAMMA_LINEAR PNG_FP_1 /* Linear */
1209#endif
1210
1211/* The following are examples of calls to png_set_alpha_mode to achieve the
1212 * required overall gamma correction and, where necessary, alpha
1213 * premultiplication.
1214 *
1215 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
1216 * This is the default libpng handling of the alpha channel - it is not
1217 * pre-multiplied into the color components. In addition the call states
1218 * that the output is for a sRGB system and causes all PNG files without gAMA
1219 * chunks to be assumed to be encoded using sRGB.
1220 *
1221 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
1222 * In this case the output is assumed to be something like an sRGB conformant
1223 * display preceeded by a power-law lookup table of power 1.45. This is how
1224 * early Mac systems behaved.
1225 *
1226 * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR);
1227 * This is the classic Jim Blinn approach and will work in academic
1228 * environments where everything is done by the book. It has the shortcoming
1229 * of assuming that input PNG data with no gamma information is linear - this
1230 * is unlikely to be correct unless the PNG files where generated locally.
1231 * Most of the time the output precision will be so low as to show
1232 * significant banding in dark areas of the image.
1233 *
1234 * png_set_expand_16(pp);
1235 * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB);
1236 * This is a somewhat more realistic Jim Blinn inspired approach. PNG files
1237 * are assumed to have the sRGB encoding if not marked with a gamma value and
1238 * the output is always 16 bits per component. This permits accurate scaling
1239 * and processing of the data. If you know that your input PNG files were
1240 * generated locally you might need to replace PNG_DEFAULT_sRGB with the
1241 * correct value for your system.
1242 *
1243 * png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB);
1244 * If you just need to composite the PNG image onto an existing background
1245 * and if you control the code that does this you can use the optimization
1246 * setting. In this case you just copy completely opaque pixels to the
1247 * output. For pixels that are not completely transparent (you just skip
1248 * those) you do the composition math using png_composite or png_composite_16
1249 * below then encode the resultant 8-bit or 16-bit values to match the output
1250 * encoding.
1251 *
1252 * Other cases
1253 * If neither the PNG nor the standard linear encoding work for you because
1254 * of the software or hardware you use then you have a big problem. The PNG
1255 * case will probably result in halos around the image. The linear encoding
1256 * will probably result in a washed out, too bright, image (it's actually too
1257 * contrasty.) Try the ALPHA_OPTIMIZED mode above - this will probably
1258 * substantially reduce the halos. Alternatively try:
1259 *
1260 * png_set_alpha_mode(pp, PNG_ALPHA_BROKEN, PNG_DEFAULT_sRGB);
1261 * This option will also reduce the halos, but there will be slight dark
1262 * halos round the opaque parts of the image where the background is light.
1263 * In the OPTIMIZED mode the halos will be light halos where the background
1264 * is dark. Take your pick - the halos are unavoidable unless you can get
1265 * your hardware/software fixed! (The OPTIMIZED approach is slightly
1266 * faster.)
1267 *
1268 * When the default gamma of PNG files doesn't match the output gamma.
1269 * If you have PNG files with no gamma information png_set_alpha_mode allows
1270 * you to provide a default gamma, but it also sets the ouput gamma to the
1271 * matching value. If you know your PNG files have a gamma that doesn't
1272 * match the output you can take advantage of the fact that
1273 * png_set_alpha_mode always sets the output gamma but only sets the PNG
1274 * default if it is not already set:
1275 *
1276 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
1277 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
1278 * The first call sets both the default and the output gamma values, the
1279 * second call overrides the output gamma without changing the default. This
1280 * is easier than achieving the same effect with png_set_gamma. You must use
1281 * PNG_ALPHA_PNG for the first call - internal checking in png_set_alpha will
1282 * fire if more than one call to png_set_alpha_mode and png_set_background is
1283 * made in the same read operation, however multiple calls with PNG_ALPHA_PNG
1284 * are ignored.
1285 */
1286
1287#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
1288PNG_EXPORT(36, void, png_set_strip_alpha, (png_structrp png_ptr));
1289#endif
1290
1291#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
1292 defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
1293PNG_EXPORT(37, void, png_set_swap_alpha, (png_structrp png_ptr));
1294#endif
1295
1296#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
1297 defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
1298PNG_EXPORT(38, void, png_set_invert_alpha, (png_structrp png_ptr));
1299#endif
1300
1301#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
1302/* Add a filler byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */
1303PNG_EXPORT(39, void, png_set_filler, (png_structrp png_ptr, png_uint_32 filler,
1304 int flags));
1305/* The values of the PNG_FILLER_ defines should NOT be changed */
1306# define PNG_FILLER_BEFORE 0
1307# define PNG_FILLER_AFTER 1
1308/* Add an alpha byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */
1309PNG_EXPORT(40, void, png_set_add_alpha, (png_structrp png_ptr,
1310 png_uint_32 filler, int flags));
1311#endif /* READ_FILLER || WRITE_FILLER */
1312
1313#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
1314/* Swap bytes in 16-bit depth files. */
1315PNG_EXPORT(41, void, png_set_swap, (png_structrp png_ptr));
1316#endif
1317
1318#if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
1319/* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
1320PNG_EXPORT(42, void, png_set_packing, (png_structrp png_ptr));
1321#endif
1322
1323#if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
1324 defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1325/* Swap packing order of pixels in bytes. */
1326PNG_EXPORT(43, void, png_set_packswap, (png_structrp png_ptr));
1327#endif
1328
1329#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
1330/* Converts files to legal bit depths. */
1331PNG_EXPORT(44, void, png_set_shift, (png_structrp png_ptr, png_const_color_8p
1332 true_bits));
1333#endif
1334
1335#if defined(PNG_READ_INTERLACING_SUPPORTED) || \
1336 defined(PNG_WRITE_INTERLACING_SUPPORTED)
1337/* Have the code handle the interlacing. Returns the number of passes.
1338 * MUST be called before png_read_update_info or png_start_read_image,
1339 * otherwise it will not have the desired effect. Note that it is still
1340 * necessary to call png_read_row or png_read_rows png_get_image_height
1341 * times for each pass.
1342*/
1343PNG_EXPORT(45, int, png_set_interlace_handling, (png_structrp png_ptr));
1344#endif
1345
1346#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
1347/* Invert monochrome files */
1348PNG_EXPORT(46, void, png_set_invert_mono, (png_structrp png_ptr));
1349#endif
1350
1351#ifdef PNG_READ_BACKGROUND_SUPPORTED
1352/* Handle alpha and tRNS by replacing with a background color. Prior to
1353 * libpng-1.5.4 this API must not be called before the PNG file header has been
1354 * read. Doing so will result in unexpected behavior and possible warnings or
1355 * errors if the PNG file contains a bKGD chunk.
1356 */
1357PNG_FP_EXPORT(47, void, png_set_background, (png_structrp png_ptr,
1358 png_const_color_16p background_color, int background_gamma_code,
1359 int need_expand, double background_gamma))
1360PNG_FIXED_EXPORT(215, void, png_set_background_fixed, (png_structrp png_ptr,
1361 png_const_color_16p background_color, int background_gamma_code,
1362 int need_expand, png_fixed_point background_gamma))
1363#endif
1364#ifdef PNG_READ_BACKGROUND_SUPPORTED
1365# define PNG_BACKGROUND_GAMMA_UNKNOWN 0
1366# define PNG_BACKGROUND_GAMMA_SCREEN 1
1367# define PNG_BACKGROUND_GAMMA_FILE 2
1368# define PNG_BACKGROUND_GAMMA_UNIQUE 3
1369#endif
1370
1371#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
1372/* Scale a 16-bit depth file down to 8-bit, accurately. */
1373PNG_EXPORT(229, void, png_set_scale_16, (png_structrp png_ptr));
1374#endif
1375
1376#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
1377#define PNG_READ_16_TO_8_SUPPORTED /* Name prior to 1.5.4 */
1378/* Strip the second byte of information from a 16-bit depth file. */
1379PNG_EXPORT(48, void, png_set_strip_16, (png_structrp png_ptr));
1380#endif
1381
1382#ifdef PNG_READ_QUANTIZE_SUPPORTED
1383/* Turn on quantizing, and reduce the palette to the number of colors
1384 * available.
1385 */
1386PNG_EXPORT(49, void, png_set_quantize, (png_structrp png_ptr,
1387 png_colorp palette, int num_palette, int maximum_colors,
1388 png_const_uint_16p histogram, int full_quantize));
1389#endif
1390
1391#ifdef PNG_READ_GAMMA_SUPPORTED
1392/* The threshold on gamma processing is configurable but hard-wired into the
1393 * library. The following is the floating point variant.
1394 */
1395#define PNG_GAMMA_THRESHOLD (PNG_GAMMA_THRESHOLD_FIXED*.00001)
1396
1397/* Handle gamma correction. Screen_gamma=(display_exponent).
1398 * NOTE: this API simply sets the screen and file gamma values. It will
1399 * therefore override the value for gamma in a PNG file if it is called after
1400 * the file header has been read - use with care - call before reading the PNG
1401 * file for best results!
1402 *
1403 * These routines accept the same gamma values as png_set_alpha_mode (described
1404 * above). The PNG_GAMMA_ defines and PNG_DEFAULT_sRGB can be passed to either
1405 * API (floating point or fixed.) Notice, however, that the 'file_gamma' value
1406 * is the inverse of a 'screen gamma' value.
1407 */
1408PNG_FP_EXPORT(50, void, png_set_gamma, (png_structrp png_ptr,
1409 double screen_gamma, double override_file_gamma))
1410PNG_FIXED_EXPORT(208, void, png_set_gamma_fixed, (png_structrp png_ptr,
1411 png_fixed_point screen_gamma, png_fixed_point override_file_gamma))
1412#endif
1413
1414#ifdef PNG_WRITE_FLUSH_SUPPORTED
1415/* Set how many lines between output flushes - 0 for no flushing */
1416PNG_EXPORT(51, void, png_set_flush, (png_structrp png_ptr, int nrows));
1417/* Flush the current PNG output buffer */
1418PNG_EXPORT(52, void, png_write_flush, (png_structrp png_ptr));
1419#endif
1420
1421/* Optional update palette with requested transformations */
1422PNG_EXPORT(53, void, png_start_read_image, (png_structrp png_ptr));
1423
1424/* Optional call to update the users info structure */
1425PNG_EXPORT(54, void, png_read_update_info, (png_structrp png_ptr,
1426 png_inforp info_ptr));
1427
1428#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1429/* Read one or more rows of image data. */
1430PNG_EXPORT(55, void, png_read_rows, (png_structrp png_ptr, png_bytepp row,
1431 png_bytepp display_row, png_uint_32 num_rows));
1432#endif
1433
1434#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1435/* Read a row of data. */
1436PNG_EXPORT(56, void, png_read_row, (png_structrp png_ptr, png_bytep row,
1437 png_bytep display_row));
1438#endif
1439
1440#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1441/* Read the whole image into memory at once. */
1442PNG_EXPORT(57, void, png_read_image, (png_structrp png_ptr, png_bytepp image));
1443#endif
1444
1445/* Write a row of image data */
1446PNG_EXPORT(58, void, png_write_row, (png_structrp png_ptr,
1447 png_const_bytep row));
1448
1449/* Write a few rows of image data: (*row) is not written; however, the type
1450 * is declared as writeable to maintain compatibility with previous versions
1451 * of libpng and to allow the 'display_row' array from read_rows to be passed
1452 * unchanged to write_rows.
1453 */
1454PNG_EXPORT(59, void, png_write_rows, (png_structrp png_ptr, png_bytepp row,
1455 png_uint_32 num_rows));
1456
1457/* Write the image data */
1458PNG_EXPORT(60, void, png_write_image, (png_structrp png_ptr, png_bytepp image));
1459
1460/* Write the end of the PNG file. */
1461PNG_EXPORT(61, void, png_write_end, (png_structrp png_ptr,
1462 png_inforp info_ptr));
1463
1464#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1465/* Read the end of the PNG file. */
1466PNG_EXPORT(62, void, png_read_end, (png_structrp png_ptr, png_inforp info_ptr));
1467#endif
1468
1469/* Free any memory associated with the png_info_struct */
1470PNG_EXPORT(63, void, png_destroy_info_struct, (png_const_structrp png_ptr,
1471 png_infopp info_ptr_ptr));
1472
1473/* Free any memory associated with the png_struct and the png_info_structs */
1474PNG_EXPORT(64, void, png_destroy_read_struct, (png_structpp png_ptr_ptr,
1475 png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr));
1476
1477/* Free any memory associated with the png_struct and the png_info_structs */
1478PNG_EXPORT(65, void, png_destroy_write_struct, (png_structpp png_ptr_ptr,
1479 png_infopp info_ptr_ptr));
1480
1481/* Set the libpng method of handling chunk CRC errors */
1482PNG_EXPORT(66, void, png_set_crc_action, (png_structrp png_ptr, int crit_action,
1483 int ancil_action));
1484
1485/* Values for png_set_crc_action() say how to handle CRC errors in
1486 * ancillary and critical chunks, and whether to use the data contained
1487 * therein. Note that it is impossible to "discard" data in a critical
1488 * chunk. For versions prior to 0.90, the action was always error/quit,
1489 * whereas in version 0.90 and later, the action for CRC errors in ancillary
1490 * chunks is warn/discard. These values should NOT be changed.
1491 *
1492 * value action:critical action:ancillary
1493 */
1494#define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */
1495#define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */
1496#define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */
1497#define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */
1498#define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */
1499#define PNG_CRC_NO_CHANGE 5 /* use current value use current value */
1500
1501#ifdef PNG_WRITE_SUPPORTED
1502/* These functions give the user control over the scan-line filtering in
1503 * libpng and the compression methods used by zlib. These functions are
1504 * mainly useful for testing, as the defaults should work with most users.
1505 * Those users who are tight on memory or want faster performance at the
1506 * expense of compression can modify them. See the compression library
1507 * header file (zlib.h) for an explination of the compression functions.
1508 */
1509
1510/* Set the filtering method(s) used by libpng. Currently, the only valid
1511 * value for "method" is 0.
1512 */
1513PNG_EXPORT(67, void, png_set_filter, (png_structrp png_ptr, int method,
1514 int filters));
1515#endif /* WRITE */
1516
1517/* Flags for png_set_filter() to say which filters to use. The flags
1518 * are chosen so that they don't conflict with real filter types
1519 * below, in case they are supplied instead of the #defined constants.
1520 * These values should NOT be changed.
1521 */
1522#define PNG_NO_FILTERS 0x00
1523#define PNG_FILTER_NONE 0x08
1524#define PNG_FILTER_SUB 0x10
1525#define PNG_FILTER_UP 0x20
1526#define PNG_FILTER_AVG 0x40
1527#define PNG_FILTER_PAETH 0x80
1528#define PNG_FAST_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP)
1529#define PNG_ALL_FILTERS (PNG_FAST_FILTERS | PNG_FILTER_AVG | PNG_FILTER_PAETH)
1530
1531/* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
1532 * These defines should NOT be changed.
1533 */
1534#define PNG_FILTER_VALUE_NONE 0
1535#define PNG_FILTER_VALUE_SUB 1
1536#define PNG_FILTER_VALUE_UP 2
1537#define PNG_FILTER_VALUE_AVG 3
1538#define PNG_FILTER_VALUE_PAETH 4
1539#define PNG_FILTER_VALUE_LAST 5
1540
1541#ifdef PNG_WRITE_SUPPORTED
1542#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* DEPRECATED */
1543PNG_FP_EXPORT(68, void, png_set_filter_heuristics, (png_structrp png_ptr,
1544 int heuristic_method, int num_weights, png_const_doublep filter_weights,
1545 png_const_doublep filter_costs))
1546PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed,
1547 (png_structrp png_ptr, int heuristic_method, int num_weights,
1548 png_const_fixed_point_p filter_weights,
1549 png_const_fixed_point_p filter_costs))
1550#endif /* WRITE_WEIGHTED_FILTER */
1551
1552/* The following are no longer used and will be removed from libpng-1.7: */
1553#define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */
1554#define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */
1555#define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */
1556#define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */
1557
1558/* Set the library compression level. Currently, valid values range from
1559 * 0 - 9, corresponding directly to the zlib compression levels 0 - 9
1560 * (0 - no compression, 9 - "maximal" compression). Note that tests have
1561 * shown that zlib compression levels 3-6 usually perform as well as level 9
1562 * for PNG images, and do considerably fewer caclulations. In the future,
1563 * these values may not correspond directly to the zlib compression levels.
1564 */
1565#ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED
1566PNG_EXPORT(69, void, png_set_compression_level, (png_structrp png_ptr,
1567 int level));
1568
1569PNG_EXPORT(70, void, png_set_compression_mem_level, (png_structrp png_ptr,
1570 int mem_level));
1571
1572PNG_EXPORT(71, void, png_set_compression_strategy, (png_structrp png_ptr,
1573 int strategy));
1574
1575/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
1576 * smaller value of window_bits if it can do so safely.
1577 */
1578PNG_EXPORT(72, void, png_set_compression_window_bits, (png_structrp png_ptr,
1579 int window_bits));
1580
1581PNG_EXPORT(73, void, png_set_compression_method, (png_structrp png_ptr,
1582 int method));
1583#endif /* WRITE_CUSTOMIZE_COMPRESSION */
1584
1585#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
1586/* Also set zlib parameters for compressing non-IDAT chunks */
1587PNG_EXPORT(222, void, png_set_text_compression_level, (png_structrp png_ptr,
1588 int level));
1589
1590PNG_EXPORT(223, void, png_set_text_compression_mem_level, (png_structrp png_ptr,
1591 int mem_level));
1592
1593PNG_EXPORT(224, void, png_set_text_compression_strategy, (png_structrp png_ptr,
1594 int strategy));
1595
1596/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
1597 * smaller value of window_bits if it can do so safely.
1598 */
1599PNG_EXPORT(225, void, png_set_text_compression_window_bits,
1600 (png_structrp png_ptr, int window_bits));
1601
1602PNG_EXPORT(226, void, png_set_text_compression_method, (png_structrp png_ptr,
1603 int method));
1604#endif /* WRITE_CUSTOMIZE_ZTXT_COMPRESSION */
1605#endif /* WRITE */
1606
1607/* These next functions are called for input/output, memory, and error
1608 * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c,
1609 * and call standard C I/O routines such as fread(), fwrite(), and
1610 * fprintf(). These functions can be made to use other I/O routines
1611 * at run time for those applications that need to handle I/O in a
1612 * different manner by calling png_set_???_fn(). See libpng-manual.txt for
1613 * more information.
1614 */
1615
1616#ifdef PNG_STDIO_SUPPORTED
1617/* Initialize the input/output for the PNG file to the default functions. */
1618PNG_EXPORT(74, void, png_init_io, (png_structrp png_ptr, png_FILE_p fp));
1619#endif
1620
1621/* Replace the (error and abort), and warning functions with user
1622 * supplied functions. If no messages are to be printed you must still
1623 * write and use replacement functions. The replacement error_fn should
1624 * still do a longjmp to the last setjmp location if you are using this
1625 * method of error handling. If error_fn or warning_fn is NULL, the
1626 * default function will be used.
1627 */
1628
1629PNG_EXPORT(75, void, png_set_error_fn, (png_structrp png_ptr,
1630 png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn));
1631
1632/* Return the user pointer associated with the error functions */
1633PNG_EXPORT(76, png_voidp, png_get_error_ptr, (png_const_structrp png_ptr));
1634
1635/* Replace the default data output functions with a user supplied one(s).
1636 * If buffered output is not used, then output_flush_fn can be set to NULL.
1637 * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time
1638 * output_flush_fn will be ignored (and thus can be NULL).
1639 * It is probably a mistake to use NULL for output_flush_fn if
1640 * write_data_fn is not also NULL unless you have built libpng with
1641 * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's
1642 * default flush function, which uses the standard *FILE structure, will
1643 * be used.
1644 */
1645PNG_EXPORT(77, void, png_set_write_fn, (png_structrp png_ptr, png_voidp io_ptr,
1646 png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn));
1647
1648/* Replace the default data input function with a user supplied one. */
1649PNG_EXPORT(78, void, png_set_read_fn, (png_structrp png_ptr, png_voidp io_ptr,
1650 png_rw_ptr read_data_fn));
1651
1652/* Return the user pointer associated with the I/O functions */
1653PNG_EXPORT(79, png_voidp, png_get_io_ptr, (png_const_structrp png_ptr));
1654
1655PNG_EXPORT(80, void, png_set_read_status_fn, (png_structrp png_ptr,
1656 png_read_status_ptr read_row_fn));
1657
1658PNG_EXPORT(81, void, png_set_write_status_fn, (png_structrp png_ptr,
1659 png_write_status_ptr write_row_fn));
1660
1661#ifdef PNG_USER_MEM_SUPPORTED
1662/* Replace the default memory allocation functions with user supplied one(s). */
1663PNG_EXPORT(82, void, png_set_mem_fn, (png_structrp png_ptr, png_voidp mem_ptr,
1664 png_malloc_ptr malloc_fn, png_free_ptr free_fn));
1665/* Return the user pointer associated with the memory functions */
1666PNG_EXPORT(83, png_voidp, png_get_mem_ptr, (png_const_structrp png_ptr));
1667#endif
1668
1669#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
1670PNG_EXPORT(84, void, png_set_read_user_transform_fn, (png_structrp png_ptr,
1671 png_user_transform_ptr read_user_transform_fn));
1672#endif
1673
1674#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
1675PNG_EXPORT(85, void, png_set_write_user_transform_fn, (png_structrp png_ptr,
1676 png_user_transform_ptr write_user_transform_fn));
1677#endif
1678
1679#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
1680PNG_EXPORT(86, void, png_set_user_transform_info, (png_structrp png_ptr,
1681 png_voidp user_transform_ptr, int user_transform_depth,
1682 int user_transform_channels));
1683/* Return the user pointer associated with the user transform functions */
1684PNG_EXPORT(87, png_voidp, png_get_user_transform_ptr,
1685 (png_const_structrp png_ptr));
1686#endif
1687
1688#ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED
1689/* Return information about the row currently being processed. Note that these
1690 * APIs do not fail but will return unexpected results if called outside a user
1691 * transform callback. Also note that when transforming an interlaced image the
1692 * row number is the row number within the sub-image of the interlace pass, so
1693 * the value will increase to the height of the sub-image (not the full image)
1694 * then reset to 0 for the next pass.
1695 *
1696 * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
1697 * find the output pixel (x,y) given an interlaced sub-image pixel
1698 * (row,col,pass). (See below for these macros.)
1699 */
1700PNG_EXPORT(217, png_uint_32, png_get_current_row_number, (png_const_structrp));
1701PNG_EXPORT(218, png_byte, png_get_current_pass_number, (png_const_structrp));
1702#endif
1703
1704#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
1705/* This callback is called only for *unknown* chunks. If
1706 * PNG_HANDLE_AS_UNKNOWN_SUPPORTED is set then it is possible to set known
1707 * chunks to be treated as unknown, however in this case the callback must do
1708 * any processing required by the chunk (e.g. by calling the appropriate
1709 * png_set_ APIs.)
1710 *
1711 * There is no write support - on write, by default, all the chunks in the
1712 * 'unknown' list are written in the specified position.
1713 *
1714 * The integer return from the callback function is interpreted thus:
1715 *
1716 * negative: An error occurred; png_chunk_error will be called.
1717 * zero: The chunk was not handled, the chunk will be saved. A critical
1718 * chunk will cause an error at this point unless it is to be saved.
1719 * positive: The chunk was handled, libpng will ignore/discard it.
1720 *
1721 * See "INTERACTION WTIH USER CHUNK CALLBACKS" below for important notes about
1722 * how this behavior will change in libpng 1.7
1723 */
1724PNG_EXPORT(88, void, png_set_read_user_chunk_fn, (png_structrp png_ptr,
1725 png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));
1726#endif
1727
1728#ifdef PNG_USER_CHUNKS_SUPPORTED
1729PNG_EXPORT(89, png_voidp, png_get_user_chunk_ptr, (png_const_structrp png_ptr));
1730#endif
1731
1732#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1733/* Sets the function callbacks for the push reader, and a pointer to a
1734 * user-defined structure available to the callback functions.
1735 */
1736PNG_EXPORT(90, void, png_set_progressive_read_fn, (png_structrp png_ptr,
1737 png_voidp progressive_ptr, png_progressive_info_ptr info_fn,
1738 png_progressive_row_ptr row_fn, png_progressive_end_ptr end_fn));
1739
1740/* Returns the user pointer associated with the push read functions */
1741PNG_EXPORT(91, png_voidp, png_get_progressive_ptr,
1742 (png_const_structrp png_ptr));
1743
1744/* Function to be called when data becomes available */
1745PNG_EXPORT(92, void, png_process_data, (png_structrp png_ptr,
1746 png_inforp info_ptr, png_bytep buffer, png_size_t buffer_size));
1747
1748/* A function which may be called *only* within png_process_data to stop the
1749 * processing of any more data. The function returns the number of bytes
1750 * remaining, excluding any that libpng has cached internally. A subsequent
1751 * call to png_process_data must supply these bytes again. If the argument
1752 * 'save' is set to true the routine will first save all the pending data and
1753 * will always return 0.
1754 */
1755PNG_EXPORT(219, png_size_t, png_process_data_pause, (png_structrp, int save));
1756
1757/* A function which may be called *only* outside (after) a call to
1758 * png_process_data. It returns the number of bytes of data to skip in the
1759 * input. Normally it will return 0, but if it returns a non-zero value the
1760 * application must skip than number of bytes of input data and pass the
1761 * following data to the next call to png_process_data.
1762 */
1763PNG_EXPORT(220, png_uint_32, png_process_data_skip, (png_structrp));
1764
1765/* Function that combines rows. 'new_row' is a flag that should come from
1766 * the callback and be non-NULL if anything needs to be done; the library
1767 * stores its own version of the new data internally and ignores the passed
1768 * in value.
1769 */
1770PNG_EXPORT(93, void, png_progressive_combine_row, (png_const_structrp png_ptr,
1771 png_bytep old_row, png_const_bytep new_row));
1772#endif /* PROGRESSIVE_READ */
1773
1774PNG_EXPORTA(94, png_voidp, png_malloc, (png_const_structrp png_ptr,
1775 png_alloc_size_t size), PNG_ALLOCATED);
1776/* Added at libpng version 1.4.0 */
1777PNG_EXPORTA(95, png_voidp, png_calloc, (png_const_structrp png_ptr,
1778 png_alloc_size_t size), PNG_ALLOCATED);
1779
1780/* Added at libpng version 1.2.4 */
1781PNG_EXPORTA(96, png_voidp, png_malloc_warn, (png_const_structrp png_ptr,
1782 png_alloc_size_t size), PNG_ALLOCATED);
1783
1784/* Frees a pointer allocated by png_malloc() */
1785PNG_EXPORT(97, void, png_free, (png_const_structrp png_ptr, png_voidp ptr));
1786
1787/* Free data that was allocated internally */
1788PNG_EXPORT(98, void, png_free_data, (png_const_structrp png_ptr,
1789 png_inforp info_ptr, png_uint_32 free_me, int num));
1790
1791/* Reassign responsibility for freeing existing data, whether allocated
1792 * by libpng or by the application; this works on the png_info structure passed
1793 * in, it does not change the state for other png_info structures.
1794 *
1795 * It is unlikely that this function works correctly as of 1.6.0 and using it
1796 * may result either in memory leaks or double free of allocated data.
1797 */
1798PNG_EXPORT(99, void, png_data_freer, (png_const_structrp png_ptr,
1799 png_inforp info_ptr, int freer, png_uint_32 mask));
1800
1801/* Assignments for png_data_freer */
1802#define PNG_DESTROY_WILL_FREE_DATA 1
1803#define PNG_SET_WILL_FREE_DATA 1
1804#define PNG_USER_WILL_FREE_DATA 2
1805/* Flags for png_ptr->free_me and info_ptr->free_me */
1806#define PNG_FREE_HIST 0x0008U
1807#define PNG_FREE_ICCP 0x0010U
1808#define PNG_FREE_SPLT 0x0020U
1809#define PNG_FREE_ROWS 0x0040U
1810#define PNG_FREE_PCAL 0x0080U
1811#define PNG_FREE_SCAL 0x0100U
1812#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
1813# define PNG_FREE_UNKN 0x0200U
1814#endif
1815/* PNG_FREE_LIST 0x0400U removed in 1.6.0 because it is ignored */
1816#define PNG_FREE_PLTE 0x1000U
1817#define PNG_FREE_TRNS 0x2000U
1818#define PNG_FREE_TEXT 0x4000U
1819#define PNG_FREE_ALL 0x7fffU
1820#define PNG_FREE_MUL 0x4220U /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */
1821
1822#ifdef PNG_USER_MEM_SUPPORTED
1823PNG_EXPORTA(100, png_voidp, png_malloc_default, (png_const_structrp png_ptr,
1824 png_alloc_size_t size), PNG_ALLOCATED PNG_DEPRECATED);
1825PNG_EXPORTA(101, void, png_free_default, (png_const_structrp png_ptr,
1826 png_voidp ptr), PNG_DEPRECATED);
1827#endif
1828
1829#ifdef PNG_ERROR_TEXT_SUPPORTED
1830/* Fatal error in PNG image of libpng - can't continue */
1831PNG_EXPORTA(102, void, png_error, (png_const_structrp png_ptr,
1832 png_const_charp error_message), PNG_NORETURN);
1833
1834/* The same, but the chunk name is prepended to the error string. */
1835PNG_EXPORTA(103, void, png_chunk_error, (png_const_structrp png_ptr,
1836 png_const_charp error_message), PNG_NORETURN);
1837
1838#else
1839/* Fatal error in PNG image of libpng - can't continue */
1840PNG_EXPORTA(104, void, png_err, (png_const_structrp png_ptr), PNG_NORETURN);
1841# define png_error(s1,s2) png_err(s1)
1842# define png_chunk_error(s1,s2) png_err(s1)
1843#endif
1844
1845#ifdef PNG_WARNINGS_SUPPORTED
1846/* Non-fatal error in libpng. Can continue, but may have a problem. */
1847PNG_EXPORT(105, void, png_warning, (png_const_structrp png_ptr,
1848 png_const_charp warning_message));
1849
1850/* Non-fatal error in libpng, chunk name is prepended to message. */
1851PNG_EXPORT(106, void, png_chunk_warning, (png_const_structrp png_ptr,
1852 png_const_charp warning_message));
1853#else
1854# define png_warning(s1,s2) ((void)(s1))
1855# define png_chunk_warning(s1,s2) ((void)(s1))
1856#endif
1857
1858#ifdef PNG_BENIGN_ERRORS_SUPPORTED
1859/* Benign error in libpng. Can continue, but may have a problem.
1860 * User can choose whether to handle as a fatal error or as a warning. */
1861PNG_EXPORT(107, void, png_benign_error, (png_const_structrp png_ptr,
1862 png_const_charp warning_message));
1863
1864#ifdef PNG_READ_SUPPORTED
1865/* Same, chunk name is prepended to message (only during read) */
1866PNG_EXPORT(108, void, png_chunk_benign_error, (png_const_structrp png_ptr,
1867 png_const_charp warning_message));
1868#endif
1869
1870PNG_EXPORT(109, void, png_set_benign_errors,
1871 (png_structrp png_ptr, int allowed));
1872#else
1873# ifdef PNG_ALLOW_BENIGN_ERRORS
1874# define png_benign_error png_warning
1875# define png_chunk_benign_error png_chunk_warning
1876# else
1877# define png_benign_error png_error
1878# define png_chunk_benign_error png_chunk_error
1879# endif
1880#endif
1881
1882/* The png_set_<chunk> functions are for storing values in the png_info_struct.
1883 * Similarly, the png_get_<chunk> calls are used to read values from the
1884 * png_info_struct, either storing the parameters in the passed variables, or
1885 * setting pointers into the png_info_struct where the data is stored. The
1886 * png_get_<chunk> functions return a non-zero value if the data was available
1887 * in info_ptr, or return zero and do not change any of the parameters if the
1888 * data was not available.
1889 *
1890 * These functions should be used instead of directly accessing png_info
1891 * to avoid problems with future changes in the size and internal layout of
1892 * png_info_struct.
1893 */
1894/* Returns "flag" if chunk data is valid in info_ptr. */
1895PNG_EXPORT(110, png_uint_32, png_get_valid, (png_const_structrp png_ptr,
1896 png_const_inforp info_ptr, png_uint_32 flag));
1897
1898/* Returns number of bytes needed to hold a transformed row. */
1899PNG_EXPORT(111, png_size_t, png_get_rowbytes, (png_const_structrp png_ptr,
1900 png_const_inforp info_ptr));
1901
1902#ifdef PNG_INFO_IMAGE_SUPPORTED
1903/* Returns row_pointers, which is an array of pointers to scanlines that was
1904 * returned from png_read_png().
1905 */
1906PNG_EXPORT(112, png_bytepp, png_get_rows, (png_const_structrp png_ptr,
1907 png_const_inforp info_ptr));
1908
1909/* Set row_pointers, which is an array of pointers to scanlines for use
1910 * by png_write_png().
1911 */
1912PNG_EXPORT(113, void, png_set_rows, (png_const_structrp png_ptr,
1913 png_inforp info_ptr, png_bytepp row_pointers));
1914#endif
1915
1916/* Returns number of color channels in image. */
1917PNG_EXPORT(114, png_byte, png_get_channels, (png_const_structrp png_ptr,
1918 png_const_inforp info_ptr));
1919
1920#ifdef PNG_EASY_ACCESS_SUPPORTED
1921/* Returns image width in pixels. */
1922PNG_EXPORT(115, png_uint_32, png_get_image_width, (png_const_structrp png_ptr,
1923 png_const_inforp info_ptr));
1924
1925/* Returns image height in pixels. */
1926PNG_EXPORT(116, png_uint_32, png_get_image_height, (png_const_structrp png_ptr,
1927 png_const_inforp info_ptr));
1928
1929/* Returns image bit_depth. */
1930PNG_EXPORT(117, png_byte, png_get_bit_depth, (png_const_structrp png_ptr,
1931 png_const_inforp info_ptr));
1932
1933/* Returns image color_type. */
1934PNG_EXPORT(118, png_byte, png_get_color_type, (png_const_structrp png_ptr,
1935 png_const_inforp info_ptr));
1936
1937/* Returns image filter_type. */
1938PNG_EXPORT(119, png_byte, png_get_filter_type, (png_const_structrp png_ptr,
1939 png_const_inforp info_ptr));
1940
1941/* Returns image interlace_type. */
1942PNG_EXPORT(120, png_byte, png_get_interlace_type, (png_const_structrp png_ptr,
1943 png_const_inforp info_ptr));
1944
1945/* Returns image compression_type. */
1946PNG_EXPORT(121, png_byte, png_get_compression_type, (png_const_structrp png_ptr,
1947 png_const_inforp info_ptr));
1948
1949/* Returns image resolution in pixels per meter, from pHYs chunk data. */
1950PNG_EXPORT(122, png_uint_32, png_get_pixels_per_meter,
1951 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1952PNG_EXPORT(123, png_uint_32, png_get_x_pixels_per_meter,
1953 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1954PNG_EXPORT(124, png_uint_32, png_get_y_pixels_per_meter,
1955 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1956
1957/* Returns pixel aspect ratio, computed from pHYs chunk data. */
1958PNG_FP_EXPORT(125, float, png_get_pixel_aspect_ratio,
1959 (png_const_structrp png_ptr, png_const_inforp info_ptr))
1960PNG_FIXED_EXPORT(210, png_fixed_point, png_get_pixel_aspect_ratio_fixed,
1961 (png_const_structrp png_ptr, png_const_inforp info_ptr))
1962
1963/* Returns image x, y offset in pixels or microns, from oFFs chunk data. */
1964PNG_EXPORT(126, png_int_32, png_get_x_offset_pixels,
1965 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1966PNG_EXPORT(127, png_int_32, png_get_y_offset_pixels,
1967 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1968PNG_EXPORT(128, png_int_32, png_get_x_offset_microns,
1969 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1970PNG_EXPORT(129, png_int_32, png_get_y_offset_microns,
1971 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1972
1973#endif /* EASY_ACCESS */
1974
1975#ifdef PNG_READ_SUPPORTED
1976/* Returns pointer to signature string read from PNG header */
1977PNG_EXPORT(130, png_const_bytep, png_get_signature, (png_const_structrp png_ptr,
1978 png_const_inforp info_ptr));
1979#endif
1980
1981#ifdef PNG_bKGD_SUPPORTED
1982PNG_EXPORT(131, png_uint_32, png_get_bKGD, (png_const_structrp png_ptr,
1983 png_inforp info_ptr, png_color_16p *background));
1984#endif
1985
1986#ifdef PNG_bKGD_SUPPORTED
1987PNG_EXPORT(132, void, png_set_bKGD, (png_const_structrp png_ptr,
1988 png_inforp info_ptr, png_const_color_16p background));
1989#endif
1990
1991#ifdef PNG_cHRM_SUPPORTED
1992PNG_FP_EXPORT(133, png_uint_32, png_get_cHRM, (png_const_structrp png_ptr,
1993 png_const_inforp info_ptr, double *white_x, double *white_y, double *red_x,
1994 double *red_y, double *green_x, double *green_y, double *blue_x,
1995 double *blue_y))
1996PNG_FP_EXPORT(230, png_uint_32, png_get_cHRM_XYZ, (png_const_structrp png_ptr,
1997 png_const_inforp info_ptr, double *red_X, double *red_Y, double *red_Z,
1998 double *green_X, double *green_Y, double *green_Z, double *blue_X,
1999 double *blue_Y, double *blue_Z))
2000PNG_FIXED_EXPORT(134, png_uint_32, png_get_cHRM_fixed,
2001 (png_const_structrp png_ptr, png_const_inforp info_ptr,
2002 png_fixed_point *int_white_x, png_fixed_point *int_white_y,
2003 png_fixed_point *int_red_x, png_fixed_point *int_red_y,
2004 png_fixed_point *int_green_x, png_fixed_point *int_green_y,
2005 png_fixed_point *int_blue_x, png_fixed_point *int_blue_y))
2006PNG_FIXED_EXPORT(231, png_uint_32, png_get_cHRM_XYZ_fixed,
2007 (png_const_structrp png_ptr, png_const_inforp info_ptr,
2008 png_fixed_point *int_red_X, png_fixed_point *int_red_Y,
2009 png_fixed_point *int_red_Z, png_fixed_point *int_green_X,
2010 png_fixed_point *int_green_Y, png_fixed_point *int_green_Z,
2011 png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y,
2012 png_fixed_point *int_blue_Z))
2013#endif
2014
2015#ifdef PNG_cHRM_SUPPORTED
2016PNG_FP_EXPORT(135, void, png_set_cHRM, (png_const_structrp png_ptr,
2017 png_inforp info_ptr,
2018 double white_x, double white_y, double red_x, double red_y, double green_x,
2019 double green_y, double blue_x, double blue_y))
2020PNG_FP_EXPORT(232, void, png_set_cHRM_XYZ, (png_const_structrp png_ptr,
2021 png_inforp info_ptr, double red_X, double red_Y, double red_Z,
2022 double green_X, double green_Y, double green_Z, double blue_X,
2023 double blue_Y, double blue_Z))
2024PNG_FIXED_EXPORT(136, void, png_set_cHRM_fixed, (png_const_structrp png_ptr,
2025 png_inforp info_ptr, png_fixed_point int_white_x,
2026 png_fixed_point int_white_y, png_fixed_point int_red_x,
2027 png_fixed_point int_red_y, png_fixed_point int_green_x,
2028 png_fixed_point int_green_y, png_fixed_point int_blue_x,
2029 png_fixed_point int_blue_y))
2030PNG_FIXED_EXPORT(233, void, png_set_cHRM_XYZ_fixed, (png_const_structrp png_ptr,
2031 png_inforp info_ptr, png_fixed_point int_red_X, png_fixed_point int_red_Y,
2032 png_fixed_point int_red_Z, png_fixed_point int_green_X,
2033 png_fixed_point int_green_Y, png_fixed_point int_green_Z,
2034 png_fixed_point int_blue_X, png_fixed_point int_blue_Y,
2035 png_fixed_point int_blue_Z))
2036#endif
2037
2038#ifdef PNG_gAMA_SUPPORTED
2039PNG_FP_EXPORT(137, png_uint_32, png_get_gAMA, (png_const_structrp png_ptr,
2040 png_const_inforp info_ptr, double *file_gamma))
2041PNG_FIXED_EXPORT(138, png_uint_32, png_get_gAMA_fixed,
2042 (png_const_structrp png_ptr, png_const_inforp info_ptr,
2043 png_fixed_point *int_file_gamma))
2044#endif
2045
2046#ifdef PNG_gAMA_SUPPORTED
2047PNG_FP_EXPORT(139, void, png_set_gAMA, (png_const_structrp png_ptr,
2048 png_inforp info_ptr, double file_gamma))
2049PNG_FIXED_EXPORT(140, void, png_set_gAMA_fixed, (png_const_structrp png_ptr,
2050 png_inforp info_ptr, png_fixed_point int_file_gamma))
2051#endif
2052
2053#ifdef PNG_hIST_SUPPORTED
2054PNG_EXPORT(141, png_uint_32, png_get_hIST, (png_const_structrp png_ptr,
2055 png_inforp info_ptr, png_uint_16p *hist));
2056#endif
2057
2058#ifdef PNG_hIST_SUPPORTED
2059PNG_EXPORT(142, void, png_set_hIST, (png_const_structrp png_ptr,
2060 png_inforp info_ptr, png_const_uint_16p hist));
2061#endif
2062
2063PNG_EXPORT(143, png_uint_32, png_get_IHDR, (png_const_structrp png_ptr,
2064 png_const_inforp info_ptr, png_uint_32 *width, png_uint_32 *height,
2065 int *bit_depth, int *color_type, int *interlace_method,
2066 int *compression_method, int *filter_method));
2067
2068PNG_EXPORT(144, void, png_set_IHDR, (png_const_structrp png_ptr,
2069 png_inforp info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth,
2070 int color_type, int interlace_method, int compression_method,
2071 int filter_method));
2072
2073#ifdef PNG_oFFs_SUPPORTED
2074PNG_EXPORT(145, png_uint_32, png_get_oFFs, (png_const_structrp png_ptr,
2075 png_const_inforp info_ptr, png_int_32 *offset_x, png_int_32 *offset_y,
2076 int *unit_type));
2077#endif
2078
2079#ifdef PNG_oFFs_SUPPORTED
2080PNG_EXPORT(146, void, png_set_oFFs, (png_const_structrp png_ptr,
2081 png_inforp info_ptr, png_int_32 offset_x, png_int_32 offset_y,
2082 int unit_type));
2083#endif
2084
2085#ifdef PNG_pCAL_SUPPORTED
2086PNG_EXPORT(147, png_uint_32, png_get_pCAL, (png_const_structrp png_ptr,
2087 png_inforp info_ptr, png_charp *purpose, png_int_32 *X0,
2088 png_int_32 *X1, int *type, int *nparams, png_charp *units,
2089 png_charpp *params));
2090#endif
2091
2092#ifdef PNG_pCAL_SUPPORTED
2093PNG_EXPORT(148, void, png_set_pCAL, (png_const_structrp png_ptr,
2094 png_inforp info_ptr, png_const_charp purpose, png_int_32 X0, png_int_32 X1,
2095 int type, int nparams, png_const_charp units, png_charpp params));
2096#endif
2097
2098#ifdef PNG_pHYs_SUPPORTED
2099PNG_EXPORT(149, png_uint_32, png_get_pHYs, (png_const_structrp png_ptr,
2100 png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y,
2101 int *unit_type));
2102#endif
2103
2104#ifdef PNG_pHYs_SUPPORTED
2105PNG_EXPORT(150, void, png_set_pHYs, (png_const_structrp png_ptr,
2106 png_inforp info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type));
2107#endif
2108
2109PNG_EXPORT(151, png_uint_32, png_get_PLTE, (png_const_structrp png_ptr,
2110 png_inforp info_ptr, png_colorp *palette, int *num_palette));
2111
2112PNG_EXPORT(152, void, png_set_PLTE, (png_structrp png_ptr,
2113 png_inforp info_ptr, png_const_colorp palette, int num_palette));
2114
2115#ifdef PNG_sBIT_SUPPORTED
2116PNG_EXPORT(153, png_uint_32, png_get_sBIT, (png_const_structrp png_ptr,
2117 png_inforp info_ptr, png_color_8p *sig_bit));
2118#endif
2119
2120#ifdef PNG_sBIT_SUPPORTED
2121PNG_EXPORT(154, void, png_set_sBIT, (png_const_structrp png_ptr,
2122 png_inforp info_ptr, png_const_color_8p sig_bit));
2123#endif
2124
2125#ifdef PNG_sRGB_SUPPORTED
2126PNG_EXPORT(155, png_uint_32, png_get_sRGB, (png_const_structrp png_ptr,
2127 png_const_inforp info_ptr, int *file_srgb_intent));
2128#endif
2129
2130#ifdef PNG_sRGB_SUPPORTED
2131PNG_EXPORT(156, void, png_set_sRGB, (png_const_structrp png_ptr,
2132 png_inforp info_ptr, int srgb_intent));
2133PNG_EXPORT(157, void, png_set_sRGB_gAMA_and_cHRM, (png_const_structrp png_ptr,
2134 png_inforp info_ptr, int srgb_intent));
2135#endif
2136
2137#ifdef PNG_iCCP_SUPPORTED
2138PNG_EXPORT(158, png_uint_32, png_get_iCCP, (png_const_structrp png_ptr,
2139 png_inforp info_ptr, png_charpp name, int *compression_type,
2140 png_bytepp profile, png_uint_32 *proflen));
2141#endif
2142
2143#ifdef PNG_iCCP_SUPPORTED
2144PNG_EXPORT(159, void, png_set_iCCP, (png_const_structrp png_ptr,
2145 png_inforp info_ptr, png_const_charp name, int compression_type,
2146 png_const_bytep profile, png_uint_32 proflen));
2147#endif
2148
2149#ifdef PNG_sPLT_SUPPORTED
2150PNG_EXPORT(160, int, png_get_sPLT, (png_const_structrp png_ptr,
2151 png_inforp info_ptr, png_sPLT_tpp entries));
2152#endif
2153
2154#ifdef PNG_sPLT_SUPPORTED
2155PNG_EXPORT(161, void, png_set_sPLT, (png_const_structrp png_ptr,
2156 png_inforp info_ptr, png_const_sPLT_tp entries, int nentries));
2157#endif
2158
2159#ifdef PNG_TEXT_SUPPORTED
2160/* png_get_text also returns the number of text chunks in *num_text */
2161PNG_EXPORT(162, int, png_get_text, (png_const_structrp png_ptr,
2162 png_inforp info_ptr, png_textp *text_ptr, int *num_text));
2163#endif
2164
2165/* Note while png_set_text() will accept a structure whose text,
2166 * language, and translated keywords are NULL pointers, the structure
2167 * returned by png_get_text will always contain regular
2168 * zero-terminated C strings. They might be empty strings but
2169 * they will never be NULL pointers.
2170 */
2171
2172#ifdef PNG_TEXT_SUPPORTED
2173PNG_EXPORT(163, void, png_set_text, (png_const_structrp png_ptr,
2174 png_inforp info_ptr, png_const_textp text_ptr, int num_text));
2175#endif
2176
2177#ifdef PNG_tIME_SUPPORTED
2178PNG_EXPORT(164, png_uint_32, png_get_tIME, (png_const_structrp png_ptr,
2179 png_inforp info_ptr, png_timep *mod_time));
2180#endif
2181
2182#ifdef PNG_tIME_SUPPORTED
2183PNG_EXPORT(165, void, png_set_tIME, (png_const_structrp png_ptr,
2184 png_inforp info_ptr, png_const_timep mod_time));
2185#endif
2186
2187#ifdef PNG_tRNS_SUPPORTED
2188PNG_EXPORT(166, png_uint_32, png_get_tRNS, (png_const_structrp png_ptr,
2189 png_inforp info_ptr, png_bytep *trans_alpha, int *num_trans,
2190 png_color_16p *trans_color));
2191#endif
2192
2193#ifdef PNG_tRNS_SUPPORTED
2194PNG_EXPORT(167, void, png_set_tRNS, (png_structrp png_ptr,
2195 png_inforp info_ptr, png_const_bytep trans_alpha, int num_trans,
2196 png_const_color_16p trans_color));
2197#endif
2198
2199#ifdef PNG_sCAL_SUPPORTED
2200PNG_FP_EXPORT(168, png_uint_32, png_get_sCAL, (png_const_structrp png_ptr,
2201 png_const_inforp info_ptr, int *unit, double *width, double *height))
2202#if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || \
2203 defined(PNG_FLOATING_POINT_SUPPORTED)
2204/* NOTE: this API is currently implemented using floating point arithmetic,
2205 * consequently it can only be used on systems with floating point support.
2206 * In any case the range of values supported by png_fixed_point is small and it
2207 * is highly recommended that png_get_sCAL_s be used instead.
2208 */
2209PNG_FIXED_EXPORT(214, png_uint_32, png_get_sCAL_fixed,
2210 (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit,
2211 png_fixed_point *width, png_fixed_point *height))
2212#endif
2213PNG_EXPORT(169, png_uint_32, png_get_sCAL_s,
2214 (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit,
2215 png_charpp swidth, png_charpp sheight));
2216
2217PNG_FP_EXPORT(170, void, png_set_sCAL, (png_const_structrp png_ptr,
2218 png_inforp info_ptr, int unit, double width, double height))
2219PNG_FIXED_EXPORT(213, void, png_set_sCAL_fixed, (png_const_structrp png_ptr,
2220 png_inforp info_ptr, int unit, png_fixed_point width,
2221 png_fixed_point height))
2222PNG_EXPORT(171, void, png_set_sCAL_s, (png_const_structrp png_ptr,
2223 png_inforp info_ptr, int unit,
2224 png_const_charp swidth, png_const_charp sheight));
2225#endif /* sCAL */
2226
2227#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
2228/* Provide the default handling for all unknown chunks or, optionally, for
2229 * specific unknown chunks.
2230 *
2231 * NOTE: prior to 1.6.0 the handling specified for particular chunks on read was
2232 * ignored and the default was used, the per-chunk setting only had an effect on
2233 * write. If you wish to have chunk-specific handling on read in code that must
2234 * work on earlier versions you must use a user chunk callback to specify the
2235 * desired handling (keep or discard.)
2236 *
2237 * The 'keep' parameter is a PNG_HANDLE_CHUNK_ value as listed below. The
2238 * parameter is interpreted as follows:
2239 *
2240 * READ:
2241 * PNG_HANDLE_CHUNK_AS_DEFAULT:
2242 * Known chunks: do normal libpng processing, do not keep the chunk (but
2243 * see the comments below about PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
2244 * Unknown chunks: for a specific chunk use the global default, when used
2245 * as the default discard the chunk data.
2246 * PNG_HANDLE_CHUNK_NEVER:
2247 * Discard the chunk data.
2248 * PNG_HANDLE_CHUNK_IF_SAFE:
2249 * Keep the chunk data if the chunk is not critical else raise a chunk
2250 * error.
2251 * PNG_HANDLE_CHUNK_ALWAYS:
2252 * Keep the chunk data.
2253 *
2254 * If the chunk data is saved it can be retrieved using png_get_unknown_chunks,
2255 * below. Notice that specifying "AS_DEFAULT" as a global default is equivalent
2256 * to specifying "NEVER", however when "AS_DEFAULT" is used for specific chunks
2257 * it simply resets the behavior to the libpng default.
2258 *
2259 * INTERACTION WTIH USER CHUNK CALLBACKS:
2260 * The per-chunk handling is always used when there is a png_user_chunk_ptr
2261 * callback and the callback returns 0; the chunk is then always stored *unless*
2262 * it is critical and the per-chunk setting is other than ALWAYS. Notice that
2263 * the global default is *not* used in this case. (In effect the per-chunk
2264 * value is incremented to at least IF_SAFE.)
2265 *
2266 * IMPORTANT NOTE: this behavior will change in libpng 1.7 - the global and
2267 * per-chunk defaults will be honored. If you want to preserve the current
2268 * behavior when your callback returns 0 you must set PNG_HANDLE_CHUNK_IF_SAFE
2269 * as the default - if you don't do this libpng 1.6 will issue a warning.
2270 *
2271 * If you want unhandled unknown chunks to be discarded in libpng 1.6 and
2272 * earlier simply return '1' (handled).
2273 *
2274 * PNG_HANDLE_AS_UNKNOWN_SUPPORTED:
2275 * If this is *not* set known chunks will always be handled by libpng and
2276 * will never be stored in the unknown chunk list. Known chunks listed to
2277 * png_set_keep_unknown_chunks will have no effect. If it is set then known
2278 * chunks listed with a keep other than AS_DEFAULT will *never* be processed
2279 * by libpng, in addition critical chunks must either be processed by the
2280 * callback or saved.
2281 *
2282 * The IHDR and IEND chunks must not be listed. Because this turns off the
2283 * default handling for chunks that would otherwise be recognized the
2284 * behavior of libpng transformations may well become incorrect!
2285 *
2286 * WRITE:
2287 * When writing chunks the options only apply to the chunks specified by
2288 * png_set_unknown_chunks (below), libpng will *always* write known chunks
2289 * required by png_set_ calls and will always write the core critical chunks
2290 * (as required for PLTE).
2291 *
2292 * Each chunk in the png_set_unknown_chunks list is looked up in the
2293 * png_set_keep_unknown_chunks list to find the keep setting, this is then
2294 * interpreted as follows:
2295 *
2296 * PNG_HANDLE_CHUNK_AS_DEFAULT:
2297 * Write safe-to-copy chunks and write other chunks if the global
2298 * default is set to _ALWAYS, otherwise don't write this chunk.
2299 * PNG_HANDLE_CHUNK_NEVER:
2300 * Do not write the chunk.
2301 * PNG_HANDLE_CHUNK_IF_SAFE:
2302 * Write the chunk if it is safe-to-copy, otherwise do not write it.
2303 * PNG_HANDLE_CHUNK_ALWAYS:
2304 * Write the chunk.
2305 *
2306 * Note that the default behavior is effectively the opposite of the read case -
2307 * in read unknown chunks are not stored by default, in write they are written
2308 * by default. Also the behavior of PNG_HANDLE_CHUNK_IF_SAFE is very different
2309 * - on write the safe-to-copy bit is checked, on read the critical bit is
2310 * checked and on read if the chunk is critical an error will be raised.
2311 *
2312 * num_chunks:
2313 * ===========
2314 * If num_chunks is positive, then the "keep" parameter specifies the manner
2315 * for handling only those chunks appearing in the chunk_list array,
2316 * otherwise the chunk list array is ignored.
2317 *
2318 * If num_chunks is 0 the "keep" parameter specifies the default behavior for
2319 * unknown chunks, as described above.
2320 *
2321 * If num_chunks is negative, then the "keep" parameter specifies the manner
2322 * for handling all unknown chunks plus all chunks recognized by libpng
2323 * except for the IHDR, PLTE, tRNS, IDAT, and IEND chunks (which continue to
2324 * be processed by libpng.
2325 */
2326#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
2327PNG_EXPORT(172, void, png_set_keep_unknown_chunks, (png_structrp png_ptr,
2328 int keep, png_const_bytep chunk_list, int num_chunks));
2329#endif /* HANDLE_AS_UNKNOWN */
2330
2331/* The "keep" PNG_HANDLE_CHUNK_ parameter for the specified chunk is returned;
2332 * the result is therefore true (non-zero) if special handling is required,
2333 * false for the default handling.
2334 */
2335PNG_EXPORT(173, int, png_handle_as_unknown, (png_const_structrp png_ptr,
2336 png_const_bytep chunk_name));
2337#endif /* SET_UNKNOWN_CHUNKS */
2338
2339#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
2340PNG_EXPORT(174, void, png_set_unknown_chunks, (png_const_structrp png_ptr,
2341 png_inforp info_ptr, png_const_unknown_chunkp unknowns,
2342 int num_unknowns));
2343 /* NOTE: prior to 1.6.0 this routine set the 'location' field of the added
2344 * unknowns to the location currently stored in the png_struct. This is
2345 * invariably the wrong value on write. To fix this call the following API
2346 * for each chunk in the list with the correct location. If you know your
2347 * code won't be compiled on earlier versions you can rely on
2348 * png_set_unknown_chunks(write-ptr, png_get_unknown_chunks(read-ptr)) doing
2349 * the correct thing.
2350 */
2351
2352PNG_EXPORT(175, void, png_set_unknown_chunk_location,
2353 (png_const_structrp png_ptr, png_inforp info_ptr, int chunk, int location));
2354
2355PNG_EXPORT(176, int, png_get_unknown_chunks, (png_const_structrp png_ptr,
2356 png_inforp info_ptr, png_unknown_chunkpp entries));
2357#endif
2358
2359/* Png_free_data() will turn off the "valid" flag for anything it frees.
2360 * If you need to turn it off for a chunk that your application has freed,
2361 * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK);
2362 */
2363PNG_EXPORT(177, void, png_set_invalid, (png_const_structrp png_ptr,
2364 png_inforp info_ptr, int mask));
2365
2366#ifdef PNG_INFO_IMAGE_SUPPORTED
2367/* The "params" pointer is currently not used and is for future expansion. */
2368#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
2369PNG_EXPORT(178, void, png_read_png, (png_structrp png_ptr, png_inforp info_ptr,
2370 int transforms, png_voidp params));
2371#endif
2372#ifdef PNG_WRITE_SUPPORTED
2373PNG_EXPORT(179, void, png_write_png, (png_structrp png_ptr, png_inforp info_ptr,
2374 int transforms, png_voidp params));
2375#endif
2376#endif
2377
2378PNG_EXPORT(180, png_const_charp, png_get_copyright,
2379 (png_const_structrp png_ptr));
2380PNG_EXPORT(181, png_const_charp, png_get_header_ver,
2381 (png_const_structrp png_ptr));
2382PNG_EXPORT(182, png_const_charp, png_get_header_version,
2383 (png_const_structrp png_ptr));
2384PNG_EXPORT(183, png_const_charp, png_get_libpng_ver,
2385 (png_const_structrp png_ptr));
2386
2387#ifdef PNG_MNG_FEATURES_SUPPORTED
2388PNG_EXPORT(184, png_uint_32, png_permit_mng_features, (png_structrp png_ptr,
2389 png_uint_32 mng_features_permitted));
2390#endif
2391
2392/* For use in png_set_keep_unknown, added to version 1.2.6 */
2393#define PNG_HANDLE_CHUNK_AS_DEFAULT 0
2394#define PNG_HANDLE_CHUNK_NEVER 1
2395#define PNG_HANDLE_CHUNK_IF_SAFE 2
2396#define PNG_HANDLE_CHUNK_ALWAYS 3
2397#define PNG_HANDLE_CHUNK_LAST 4
2398
2399/* Strip the prepended error numbers ("#nnn ") from error and warning
2400 * messages before passing them to the error or warning handler.
2401 */
2402#ifdef PNG_ERROR_NUMBERS_SUPPORTED
2403PNG_EXPORT(185, void, png_set_strip_error_numbers, (png_structrp png_ptr,
2404 png_uint_32 strip_mode));
2405#endif
2406
2407/* Added in libpng-1.2.6 */
2408#ifdef PNG_SET_USER_LIMITS_SUPPORTED
2409PNG_EXPORT(186, void, png_set_user_limits, (png_structrp png_ptr,
2410 png_uint_32 user_width_max, png_uint_32 user_height_max));
2411PNG_EXPORT(187, png_uint_32, png_get_user_width_max,
2412 (png_const_structrp png_ptr));
2413PNG_EXPORT(188, png_uint_32, png_get_user_height_max,
2414 (png_const_structrp png_ptr));
2415/* Added in libpng-1.4.0 */
2416PNG_EXPORT(189, void, png_set_chunk_cache_max, (png_structrp png_ptr,
2417 png_uint_32 user_chunk_cache_max));
2418PNG_EXPORT(190, png_uint_32, png_get_chunk_cache_max,
2419 (png_const_structrp png_ptr));
2420/* Added in libpng-1.4.1 */
2421PNG_EXPORT(191, void, png_set_chunk_malloc_max, (png_structrp png_ptr,
2422 png_alloc_size_t user_chunk_cache_max));
2423PNG_EXPORT(192, png_alloc_size_t, png_get_chunk_malloc_max,
2424 (png_const_structrp png_ptr));
2425#endif
2426
2427#if defined(PNG_INCH_CONVERSIONS_SUPPORTED)
2428PNG_EXPORT(193, png_uint_32, png_get_pixels_per_inch,
2429 (png_const_structrp png_ptr, png_const_inforp info_ptr));
2430
2431PNG_EXPORT(194, png_uint_32, png_get_x_pixels_per_inch,
2432 (png_const_structrp png_ptr, png_const_inforp info_ptr));
2433
2434PNG_EXPORT(195, png_uint_32, png_get_y_pixels_per_inch,
2435 (png_const_structrp png_ptr, png_const_inforp info_ptr));
2436
2437PNG_FP_EXPORT(196, float, png_get_x_offset_inches,
2438 (png_const_structrp png_ptr, png_const_inforp info_ptr))
2439#ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */
2440PNG_FIXED_EXPORT(211, png_fixed_point, png_get_x_offset_inches_fixed,
2441 (png_const_structrp png_ptr, png_const_inforp info_ptr))
2442#endif
2443
2444PNG_FP_EXPORT(197, float, png_get_y_offset_inches, (png_const_structrp png_ptr,
2445 png_const_inforp info_ptr))
2446#ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */
2447PNG_FIXED_EXPORT(212, png_fixed_point, png_get_y_offset_inches_fixed,
2448 (png_const_structrp png_ptr, png_const_inforp info_ptr))
2449#endif
2450
2451# ifdef PNG_pHYs_SUPPORTED
2452PNG_EXPORT(198, png_uint_32, png_get_pHYs_dpi, (png_const_structrp png_ptr,
2453 png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y,
2454 int *unit_type));
2455# endif /* pHYs */
2456#endif /* INCH_CONVERSIONS */
2457
2458/* Added in libpng-1.4.0 */
2459#ifdef PNG_IO_STATE_SUPPORTED
2460PNG_EXPORT(199, png_uint_32, png_get_io_state, (png_const_structrp png_ptr));
2461
2462/* Removed from libpng 1.6; use png_get_io_chunk_type. */
2463PNG_REMOVED(200, png_const_bytep, png_get_io_chunk_name, (png_structrp png_ptr),
2464 PNG_DEPRECATED)
2465
2466PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type,
2467 (png_const_structrp png_ptr));
2468
2469/* The flags returned by png_get_io_state() are the following: */
2470# define PNG_IO_NONE 0x0000 /* no I/O at this moment */
2471# define PNG_IO_READING 0x0001 /* currently reading */
2472# define PNG_IO_WRITING 0x0002 /* currently writing */
2473# define PNG_IO_SIGNATURE 0x0010 /* currently at the file signature */
2474# define PNG_IO_CHUNK_HDR 0x0020 /* currently at the chunk header */
2475# define PNG_IO_CHUNK_DATA 0x0040 /* currently at the chunk data */
2476# define PNG_IO_CHUNK_CRC 0x0080 /* currently at the chunk crc */
2477# define PNG_IO_MASK_OP 0x000f /* current operation: reading/writing */
2478# define PNG_IO_MASK_LOC 0x00f0 /* current location: sig/hdr/data/crc */
2479#endif /* IO_STATE */
2480
2481/* Interlace support. The following macros are always defined so that if
2482 * libpng interlace handling is turned off the macros may be used to handle
2483 * interlaced images within the application.
2484 */
2485#define PNG_INTERLACE_ADAM7_PASSES 7
2486
2487/* Two macros to return the first row and first column of the original,
2488 * full, image which appears in a given pass. 'pass' is in the range 0
2489 * to 6 and the result is in the range 0 to 7.
2490 */
2491#define PNG_PASS_START_ROW(pass) (((1&~(pass))<<(3-((pass)>>1)))&7)
2492#define PNG_PASS_START_COL(pass) (((1& (pass))<<(3-(((pass)+1)>>1)))&7)
2493
2494/* A macro to return the offset between pixels in the output row for a pair of
2495 * pixels in the input - effectively the inverse of the 'COL_SHIFT' macro that
2496 * follows. Note that ROW_OFFSET is the offset from one row to the next whereas
2497 * COL_OFFSET is from one column to the next, within a row.
2498 */
2499#define PNG_PASS_ROW_OFFSET(pass) ((pass)>2?(8>>(((pass)-1)>>1)):8)
2500#define PNG_PASS_COL_OFFSET(pass) (1<<((7-(pass))>>1))
2501
2502/* Two macros to help evaluate the number of rows or columns in each
2503 * pass. This is expressed as a shift - effectively log2 of the number or
2504 * rows or columns in each 8x8 tile of the original image.
2505 */
2506#define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3)
2507#define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3)
2508
2509/* Hence two macros to determine the number of rows or columns in a given
2510 * pass of an image given its height or width. In fact these macros may
2511 * return non-zero even though the sub-image is empty, because the other
2512 * dimension may be empty for a small image.
2513 */
2514#define PNG_PASS_ROWS(height, pass) (((height)+(((1<<PNG_PASS_ROW_SHIFT(pass))\
2515 -1)-PNG_PASS_START_ROW(pass)))>>PNG_PASS_ROW_SHIFT(pass))
2516#define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\
2517 -1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass))
2518
2519/* For the reader row callbacks (both progressive and sequential) it is
2520 * necessary to find the row in the output image given a row in an interlaced
2521 * image, so two more macros:
2522 */
2523#define PNG_ROW_FROM_PASS_ROW(y_in, pass) \
2524 (((y_in)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass))
2525#define PNG_COL_FROM_PASS_COL(x_in, pass) \
2526 (((x_in)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass))
2527
2528/* Two macros which return a boolean (0 or 1) saying whether the given row
2529 * or column is in a particular pass. These use a common utility macro that
2530 * returns a mask for a given pass - the offset 'off' selects the row or
2531 * column version. The mask has the appropriate bit set for each column in
2532 * the tile.
2533 */
2534#define PNG_PASS_MASK(pass,off) ( \
2535 ((0x110145AF>>(((7-(off))-(pass))<<2)) & 0xF) | \
2536 ((0x01145AF0>>(((7-(off))-(pass))<<2)) & 0xF0))
2537
2538#define PNG_ROW_IN_INTERLACE_PASS(y, pass) \
2539 ((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1)
2540#define PNG_COL_IN_INTERLACE_PASS(x, pass) \
2541 ((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1)
2542
2543#ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
2544/* With these routines we avoid an integer divide, which will be slower on
2545 * most machines. However, it does take more operations than the corresponding
2546 * divide method, so it may be slower on a few RISC systems. There are two
2547 * shifts (by 8 or 16 bits) and an addition, versus a single integer divide.
2548 *
2549 * Note that the rounding factors are NOT supposed to be the same! 128 and
2550 * 32768 are correct for the NODIV code; 127 and 32767 are correct for the
2551 * standard method.
2552 *
2553 * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
2554 */
2555
2556 /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */
2557
2558# define png_composite(composite, fg, alpha, bg) \
2559 { \
2560 png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \
2561 * (png_uint_16)(alpha) \
2562 + (png_uint_16)(bg)*(png_uint_16)(255 \
2563 - (png_uint_16)(alpha)) + 128); \
2564 (composite) = (png_byte)(((temp + (temp >> 8)) >> 8) & 0xff); \
2565 }
2566
2567# define png_composite_16(composite, fg, alpha, bg) \
2568 { \
2569 png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) \
2570 * (png_uint_32)(alpha) \
2571 + (png_uint_32)(bg)*(65535 \
2572 - (png_uint_32)(alpha)) + 32768); \
2573 (composite) = (png_uint_16)(0xffff & ((temp + (temp >> 16)) >> 16)); \
2574 }
2575
2576#else /* Standard method using integer division */
2577
2578# define png_composite(composite, fg, alpha, bg) \
2579 (composite) = \
2580 (png_byte)(0xff & (((png_uint_16)(fg) * (png_uint_16)(alpha) + \
2581 (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \
2582 127) / 255))
2583
2584# define png_composite_16(composite, fg, alpha, bg) \
2585 (composite) = \
2586 (png_uint_16)(0xffff & (((png_uint_32)(fg) * (png_uint_32)(alpha) + \
2587 (png_uint_32)(bg)*(png_uint_32)(65535 - (png_uint_32)(alpha)) + \
2588 32767) / 65535))
2589#endif /* READ_COMPOSITE_NODIV */
2590
2591#ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED
2592PNG_EXPORT(201, png_uint_32, png_get_uint_32, (png_const_bytep buf));
2593PNG_EXPORT(202, png_uint_16, png_get_uint_16, (png_const_bytep buf));
2594PNG_EXPORT(203, png_int_32, png_get_int_32, (png_const_bytep buf));
2595#endif
2596
2597PNG_EXPORT(204, png_uint_32, png_get_uint_31, (png_const_structrp png_ptr,
2598 png_const_bytep buf));
2599/* No png_get_int_16 -- may be added if there's a real need for it. */
2600
2601/* Place a 32-bit number into a buffer in PNG byte order (big-endian). */
2602#ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
2603PNG_EXPORT(205, void, png_save_uint_32, (png_bytep buf, png_uint_32 i));
2604#endif
2605#ifdef PNG_SAVE_INT_32_SUPPORTED
2606PNG_EXPORT(206, void, png_save_int_32, (png_bytep buf, png_int_32 i));
2607#endif
2608
2609/* Place a 16-bit number into a buffer in PNG byte order.
2610 * The parameter is declared unsigned int, not png_uint_16,
2611 * just to avoid potential problems on pre-ANSI C compilers.
2612 */
2613#ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
2614PNG_EXPORT(207, void, png_save_uint_16, (png_bytep buf, unsigned int i));
2615/* No png_save_int_16 -- may be added if there's a real need for it. */
2616#endif
2617
2618#ifdef PNG_USE_READ_MACROS
2619/* Inline macros to do direct reads of bytes from the input buffer.
2620 * The png_get_int_32() routine assumes we are using two's complement
2621 * format for negative values, which is almost certainly true.
2622 */
2623# define PNG_get_uint_32(buf) \
2624 (((png_uint_32)(*(buf)) << 24) + \
2625 ((png_uint_32)(*((buf) + 1)) << 16) + \
2626 ((png_uint_32)(*((buf) + 2)) << 8) + \
2627 ((png_uint_32)(*((buf) + 3))))
2628
2629 /* From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the
2630 * function) incorrectly returned a value of type png_uint_32.
2631 */
2632# define PNG_get_uint_16(buf) \
2633 ((png_uint_16) \
2634 (((unsigned int)(*(buf)) << 8) + \
2635 ((unsigned int)(*((buf) + 1)))))
2636
2637# define PNG_get_int_32(buf) \
2638 ((png_int_32)((*(buf) & 0x80) \
2639 ? -((png_int_32)(((png_get_uint_32(buf)^0xffffffffU)+1U)&0x7fffffffU)) \
2640 : (png_int_32)png_get_uint_32(buf)))
2641
2642/* If PNG_PREFIX is defined the same thing as below happens in pnglibconf.h,
2643 * but defining a macro name prefixed with PNG_PREFIX.
2644 */
2645# ifndef PNG_PREFIX
2646# define png_get_uint_32(buf) PNG_get_uint_32(buf)
2647# define png_get_uint_16(buf) PNG_get_uint_16(buf)
2648# define png_get_int_32(buf) PNG_get_int_32(buf)
2649# endif
2650#else
2651# ifdef PNG_PREFIX
2652 /* No macros; revert to the (redefined) function */
2653# define PNG_get_uint_32 (png_get_uint_32)
2654# define PNG_get_uint_16 (png_get_uint_16)
2655# define PNG_get_int_32 (png_get_int_32)
2656# endif
2657#endif
2658
2659#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
2660PNG_EXPORT(242, void, png_set_check_for_invalid_index,
2661 (png_structrp png_ptr, int allowed));
2662# ifdef PNG_GET_PALETTE_MAX_SUPPORTED
2663PNG_EXPORT(243, int, png_get_palette_max, (png_const_structp png_ptr,
2664 png_const_infop info_ptr));
2665# endif
2666#endif /* CHECK_FOR_INVALID_INDEX */
2667
2668/*******************************************************************************
2669 * Section 5: SIMPLIFIED API
2670 *******************************************************************************
2671 *
2672 * Please read the documentation in libpng-manual.txt (TODO: write said
2673 * documentation) if you don't understand what follows.
2674 *
2675 * The simplified API hides the details of both libpng and the PNG file format
2676 * itself. It allows PNG files to be read into a very limited number of
2677 * in-memory bitmap formats or to be written from the same formats. If these
2678 * formats do not accomodate your needs then you can, and should, use the more
2679 * sophisticated APIs above - these support a wide variety of in-memory formats
2680 * and a wide variety of sophisticated transformations to those formats as well
2681 * as a wide variety of APIs to manipulate ancillary information.
2682 *
2683 * To read a PNG file using the simplified API:
2684 *
2685 * 1) Declare a 'png_image' structure (see below) on the stack, set the
2686 * version field to PNG_IMAGE_VERSION and the 'opaque' pointer to NULL
2687 * (this is REQUIRED, your program may crash if you don't do it.)
2688 * 2) Call the appropriate png_image_begin_read... function.
2689 * 3) Set the png_image 'format' member to the required sample format.
2690 * 4) Allocate a buffer for the image and, if required, the color-map.
2691 * 5) Call png_image_finish_read to read the image and, if required, the
2692 * color-map into your buffers.
2693 *
2694 * There are no restrictions on the format of the PNG input itself; all valid
2695 * color types, bit depths, and interlace methods are acceptable, and the
2696 * input image is transformed as necessary to the requested in-memory format
2697 * during the png_image_finish_read() step. The only caveat is that if you
2698 * request a color-mapped image from a PNG that is full-color or makes
2699 * complex use of an alpha channel the transformation is extremely lossy and the
2700 * result may look terrible.
2701 *
2702 * To write a PNG file using the simplified API:
2703 *
2704 * 1) Declare a 'png_image' structure on the stack and memset() it to all zero.
2705 * 2) Initialize the members of the structure that describe the image, setting
2706 * the 'format' member to the format of the image samples.
2707 * 3) Call the appropriate png_image_write... function with a pointer to the
2708 * image and, if necessary, the color-map to write the PNG data.
2709 *
2710 * png_image is a structure that describes the in-memory format of an image
2711 * when it is being read or defines the in-memory format of an image that you
2712 * need to write:
2713 */
2714#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) || \
2715 defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
2716
2717#define PNG_IMAGE_VERSION 1
2718
2719typedef struct png_control *png_controlp;
2720typedef struct
2721{
2722 png_controlp opaque; /* Initialize to NULL, free with png_image_free */
2723 png_uint_32 version; /* Set to PNG_IMAGE_VERSION */
2724 png_uint_32 width; /* Image width in pixels (columns) */
2725 png_uint_32 height; /* Image height in pixels (rows) */
2726 png_uint_32 format; /* Image format as defined below */
2727 png_uint_32 flags; /* A bit mask containing informational flags */
2728 png_uint_32 colormap_entries;
2729 /* Number of entries in the color-map */
2730
2731 /* In the event of an error or warning the following field will be set to a
2732 * non-zero value and the 'message' field will contain a '\0' terminated
2733 * string with the libpng error or warning message. If both warnings and
2734 * an error were encountered, only the error is recorded. If there
2735 * are multiple warnings, only the first one is recorded.
2736 *
2737 * The upper 30 bits of this value are reserved, the low two bits contain
2738 * a value as follows:
2739 */
2740# define PNG_IMAGE_WARNING 1
2741# define PNG_IMAGE_ERROR 2
2742 /*
2743 * The result is a two-bit code such that a value more than 1 indicates
2744 * a failure in the API just called:
2745 *
2746 * 0 - no warning or error
2747 * 1 - warning
2748 * 2 - error
2749 * 3 - error preceded by warning
2750 */
2751# define PNG_IMAGE_FAILED(png_cntrl) ((((png_cntrl).warning_or_error)&0x03)>1)
2752
2753 png_uint_32 warning_or_error;
2754
2755 char message[64];
2756} png_image, *png_imagep;
2757
2758/* The samples of the image have one to four channels whose components have
2759 * original values in the range 0 to 1.0:
2760 *
2761 * 1: A single gray or luminance channel (G).
2762 * 2: A gray/luminance channel and an alpha channel (GA).
2763 * 3: Three red, green, blue color channels (RGB).
2764 * 4: Three color channels and an alpha channel (RGBA).
2765 *
2766 * The components are encoded in one of two ways:
2767 *
2768 * a) As a small integer, value 0..255, contained in a single byte. For the
2769 * alpha channel the original value is simply value/255. For the color or
2770 * luminance channels the value is encoded according to the sRGB specification
2771 * and matches the 8-bit format expected by typical display devices.
2772 *
2773 * The color/gray channels are not scaled (pre-multiplied) by the alpha
2774 * channel and are suitable for passing to color management software.
2775 *
2776 * b) As a value in the range 0..65535, contained in a 2-byte integer. All
2777 * channels can be converted to the original value by dividing by 65535; all
2778 * channels are linear. Color channels use the RGB encoding (RGB end-points) of
2779 * the sRGB specification. This encoding is identified by the
2780 * PNG_FORMAT_FLAG_LINEAR flag below.
2781 *
2782 * When the simplified API needs to convert between sRGB and linear colorspaces,
2783 * the actual sRGB transfer curve defined in the sRGB specification (see the
2784 * article at http://en.wikipedia.org/wiki/SRGB) is used, not the gamma=1/2.2
2785 * approximation used elsewhere in libpng.
2786 *
2787 * When an alpha channel is present it is expected to denote pixel coverage
2788 * of the color or luminance channels and is returned as an associated alpha
2789 * channel: the color/gray channels are scaled (pre-multiplied) by the alpha
2790 * value.
2791 *
2792 * The samples are either contained directly in the image data, between 1 and 8
2793 * bytes per pixel according to the encoding, or are held in a color-map indexed
2794 * by bytes in the image data. In the case of a color-map the color-map entries
2795 * are individual samples, encoded as above, and the image data has one byte per
2796 * pixel to select the relevant sample from the color-map.
2797 */
2798
2799/* PNG_FORMAT_*
2800 *
2801 * #defines to be used in png_image::format. Each #define identifies a
2802 * particular layout of sample data and, if present, alpha values. There are
2803 * separate defines for each of the two component encodings.
2804 *
2805 * A format is built up using single bit flag values. All combinations are
2806 * valid. Formats can be built up from the flag values or you can use one of
2807 * the predefined values below. When testing formats always use the FORMAT_FLAG
2808 * macros to test for individual features - future versions of the library may
2809 * add new flags.
2810 *
2811 * When reading or writing color-mapped images the format should be set to the
2812 * format of the entries in the color-map then png_image_{read,write}_colormap
2813 * called to read or write the color-map and set the format correctly for the
2814 * image data. Do not set the PNG_FORMAT_FLAG_COLORMAP bit directly!
2815 *
2816 * NOTE: libpng can be built with particular features disabled. If you see
2817 * compiler errors because the definition of one of the following flags has been
2818 * compiled out it is because libpng does not have the required support. It is
2819 * possible, however, for the libpng configuration to enable the format on just
2820 * read or just write; in that case you may see an error at run time. You can
2821 * guard against this by checking for the definition of the appropriate
2822 * "_SUPPORTED" macro, one of:
2823 *
2824 * PNG_SIMPLIFIED_{READ,WRITE}_{BGR,AFIRST}_SUPPORTED
2825 */
2826#define PNG_FORMAT_FLAG_ALPHA 0x01U /* format with an alpha channel */
2827#define PNG_FORMAT_FLAG_COLOR 0x02U /* color format: otherwise grayscale */
2828#define PNG_FORMAT_FLAG_LINEAR 0x04U /* 2-byte channels else 1-byte */
2829#define PNG_FORMAT_FLAG_COLORMAP 0x08U /* image data is color-mapped */
2830
2831#ifdef PNG_FORMAT_BGR_SUPPORTED
2832# define PNG_FORMAT_FLAG_BGR 0x10U /* BGR colors, else order is RGB */
2833#endif
2834
2835#ifdef PNG_FORMAT_AFIRST_SUPPORTED
2836# define PNG_FORMAT_FLAG_AFIRST 0x20U /* alpha channel comes first */
2837#endif
2838
2839/* Commonly used formats have predefined macros.
2840 *
2841 * First the single byte (sRGB) formats:
2842 */
2843#define PNG_FORMAT_GRAY 0
2844#define PNG_FORMAT_GA PNG_FORMAT_FLAG_ALPHA
2845#define PNG_FORMAT_AG (PNG_FORMAT_GA|PNG_FORMAT_FLAG_AFIRST)
2846#define PNG_FORMAT_RGB PNG_FORMAT_FLAG_COLOR
2847#define PNG_FORMAT_BGR (PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_BGR)
2848#define PNG_FORMAT_RGBA (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_ALPHA)
2849#define PNG_FORMAT_ARGB (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_AFIRST)
2850#define PNG_FORMAT_BGRA (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_ALPHA)
2851#define PNG_FORMAT_ABGR (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_AFIRST)
2852
2853/* Then the linear 2-byte formats. When naming these "Y" is used to
2854 * indicate a luminance (gray) channel.
2855 */
2856#define PNG_FORMAT_LINEAR_Y PNG_FORMAT_FLAG_LINEAR
2857#define PNG_FORMAT_LINEAR_Y_ALPHA (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_ALPHA)
2858#define PNG_FORMAT_LINEAR_RGB (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR)
2859#define PNG_FORMAT_LINEAR_RGB_ALPHA \
2860 (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA)
2861
2862/* With color-mapped formats the image data is one byte for each pixel, the byte
2863 * is an index into the color-map which is formatted as above. To obtain a
2864 * color-mapped format it is sufficient just to add the PNG_FOMAT_FLAG_COLORMAP
2865 * to one of the above definitions, or you can use one of the definitions below.
2866 */
2867#define PNG_FORMAT_RGB_COLORMAP (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_COLORMAP)
2868#define PNG_FORMAT_BGR_COLORMAP (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_COLORMAP)
2869#define PNG_FORMAT_RGBA_COLORMAP (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_COLORMAP)
2870#define PNG_FORMAT_ARGB_COLORMAP (PNG_FORMAT_ARGB|PNG_FORMAT_FLAG_COLORMAP)
2871#define PNG_FORMAT_BGRA_COLORMAP (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_COLORMAP)
2872#define PNG_FORMAT_ABGR_COLORMAP (PNG_FORMAT_ABGR|PNG_FORMAT_FLAG_COLORMAP)
2873
2874/* PNG_IMAGE macros
2875 *
2876 * These are convenience macros to derive information from a png_image
2877 * structure. The PNG_IMAGE_SAMPLE_ macros return values appropriate to the
2878 * actual image sample values - either the entries in the color-map or the
2879 * pixels in the image. The PNG_IMAGE_PIXEL_ macros return corresponding values
2880 * for the pixels and will always return 1 for color-mapped formats. The
2881 * remaining macros return information about the rows in the image and the
2882 * complete image.
2883 *
2884 * NOTE: All the macros that take a png_image::format parameter are compile time
2885 * constants if the format parameter is, itself, a constant. Therefore these
2886 * macros can be used in array declarations and case labels where required.
2887 * Similarly the macros are also pre-processor constants (sizeof is not used) so
2888 * they can be used in #if tests.
2889 *
2890 * First the information about the samples.
2891 */
2892#define PNG_IMAGE_SAMPLE_CHANNELS(fmt)\
2893 (((fmt)&(PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA))+1)
2894 /* Return the total number of channels in a given format: 1..4 */
2895
2896#define PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)\
2897 ((((fmt) & PNG_FORMAT_FLAG_LINEAR) >> 2)+1)
2898 /* Return the size in bytes of a single component of a pixel or color-map
2899 * entry (as appropriate) in the image: 1 or 2.
2900 */
2901
2902#define PNG_IMAGE_SAMPLE_SIZE(fmt)\
2903 (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt))
2904 /* This is the size of the sample data for one sample. If the image is
2905 * color-mapped it is the size of one color-map entry (and image pixels are
2906 * one byte in size), otherwise it is the size of one image pixel.
2907 */
2908
2909#define PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(fmt)\
2910 (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * 256)
2911 /* The maximum size of the color-map required by the format expressed in a
2912 * count of components. This can be used to compile-time allocate a
2913 * color-map:
2914 *
2915 * png_uint_16 colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(linear_fmt)];
2916 *
2917 * png_byte colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(sRGB_fmt)];
2918 *
2919 * Alternatively use the PNG_IMAGE_COLORMAP_SIZE macro below to use the
2920 * information from one of the png_image_begin_read_ APIs and dynamically
2921 * allocate the required memory.
2922 */
2923
2924/* Corresponding information about the pixels */
2925#define PNG_IMAGE_PIXEL_(test,fmt)\
2926 (((fmt)&PNG_FORMAT_FLAG_COLORMAP)?1:test(fmt))
2927
2928#define PNG_IMAGE_PIXEL_CHANNELS(fmt)\
2929 PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_CHANNELS,fmt)
2930 /* The number of separate channels (components) in a pixel; 1 for a
2931 * color-mapped image.
2932 */
2933
2934#define PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt)\
2935 PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_COMPONENT_SIZE,fmt)
2936 /* The size, in bytes, of each component in a pixel; 1 for a color-mapped
2937 * image.
2938 */
2939
2940#define PNG_IMAGE_PIXEL_SIZE(fmt) PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_SIZE,fmt)
2941 /* The size, in bytes, of a complete pixel; 1 for a color-mapped image. */
2942
2943/* Information about the whole row, or whole image */
2944#define PNG_IMAGE_ROW_STRIDE(image)\
2945 (PNG_IMAGE_PIXEL_CHANNELS((image).format) * (image).width)
2946 /* Return the total number of components in a single row of the image; this
2947 * is the minimum 'row stride', the minimum count of components between each
2948 * row. For a color-mapped image this is the minimum number of bytes in a
2949 * row.
2950 *
2951 * WARNING: this macro overflows for some images with more than one component
2952 * and very large image widths. libpng will refuse to process an image where
2953 * this macro would overflow.
2954 */
2955
2956#define PNG_IMAGE_BUFFER_SIZE(image, row_stride)\
2957 (PNG_IMAGE_PIXEL_COMPONENT_SIZE((image).format)*(image).height*(row_stride))
2958 /* Return the size, in bytes, of an image buffer given a png_image and a row
2959 * stride - the number of components to leave space for in each row.
2960 *
2961 * WARNING: this macro overflows a 32-bit integer for some large PNG images,
2962 * libpng will refuse to process an image where such an overflow would occur.
2963 */
2964
2965#define PNG_IMAGE_SIZE(image)\
2966 PNG_IMAGE_BUFFER_SIZE(image, PNG_IMAGE_ROW_STRIDE(image))
2967 /* Return the size, in bytes, of the image in memory given just a png_image;
2968 * the row stride is the minimum stride required for the image.
2969 */
2970
2971#define PNG_IMAGE_COLORMAP_SIZE(image)\
2972 (PNG_IMAGE_SAMPLE_SIZE((image).format) * (image).colormap_entries)
2973 /* Return the size, in bytes, of the color-map of this image. If the image
2974 * format is not a color-map format this will return a size sufficient for
2975 * 256 entries in the given format; check PNG_FORMAT_FLAG_COLORMAP if
2976 * you don't want to allocate a color-map in this case.
2977 */
2978
2979/* PNG_IMAGE_FLAG_*
2980 *
2981 * Flags containing additional information about the image are held in the
2982 * 'flags' field of png_image.
2983 */
2984#define PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB 0x01
2985 /* This indicates the the RGB values of the in-memory bitmap do not
2986 * correspond to the red, green and blue end-points defined by sRGB.
2987 */
2988
2989#define PNG_IMAGE_FLAG_FAST 0x02
2990 /* On write emphasise speed over compression; the resultant PNG file will be
2991 * larger but will be produced significantly faster, particular for large
2992 * images. Do not use this option for images which will be distributed, only
2993 * used it when producing intermediate files that will be read back in
2994 * repeatedly. For a typical 24-bit image the option will double the read
2995 * speed at the cost of increasing the image size by 25%, however for many
2996 * more compressible images the PNG file can be 10 times larger with only a
2997 * slight speed gain.
2998 */
2999
3000#define PNG_IMAGE_FLAG_16BIT_sRGB 0x04
3001 /* On read if the image is a 16-bit per component image and there is no gAMA
3002 * or sRGB chunk assume that the components are sRGB encoded. Notice that
3003 * images output by the simplified API always have gamma information; setting
3004 * this flag only affects the interpretation of 16-bit images from an
3005 * external source. It is recommended that the application expose this flag
3006 * to the user; the user can normally easily recognize the difference between
3007 * linear and sRGB encoding. This flag has no effect on write - the data
3008 * passed to the write APIs must have the correct encoding (as defined
3009 * above.)
3010 *
3011 * If the flag is not set (the default) input 16-bit per component data is
3012 * assumed to be linear.
3013 *
3014 * NOTE: the flag can only be set after the png_image_begin_read_ call,
3015 * because that call initializes the 'flags' field.
3016 */
3017
3018#ifdef PNG_SIMPLIFIED_READ_SUPPORTED
3019/* READ APIs
3020 * ---------
3021 *
3022 * The png_image passed to the read APIs must have been initialized by setting
3023 * the png_controlp field 'opaque' to NULL (or, safer, memset the whole thing.)
3024 */
3025#ifdef PNG_STDIO_SUPPORTED
3026PNG_EXPORT(234, int, png_image_begin_read_from_file, (png_imagep image,
3027 const char *file_name));
3028 /* The named file is opened for read and the image header is filled in
3029 * from the PNG header in the file.
3030 */
3031
3032PNG_EXPORT(235, int, png_image_begin_read_from_stdio, (png_imagep image,
3033 FILE* file));
3034 /* The PNG header is read from the stdio FILE object. */
3035#endif /* STDIO */
3036
3037PNG_EXPORT(236, int, png_image_begin_read_from_memory, (png_imagep image,
3038 png_const_voidp memory, png_size_t size));
3039 /* The PNG header is read from the given memory buffer. */
3040
3041PNG_EXPORT(237, int, png_image_finish_read, (png_imagep image,
3042 png_const_colorp background, void *buffer, png_int_32 row_stride,
3043 void *colormap));
3044 /* Finish reading the image into the supplied buffer and clean up the
3045 * png_image structure.
3046 *
3047 * row_stride is the step, in byte or 2-byte units as appropriate,
3048 * between adjacent rows. A positive stride indicates that the top-most row
3049 * is first in the buffer - the normal top-down arrangement. A negative
3050 * stride indicates that the bottom-most row is first in the buffer.
3051 *
3052 * background need only be supplied if an alpha channel must be removed from
3053 * a png_byte format and the removal is to be done by compositing on a solid
3054 * color; otherwise it may be NULL and any composition will be done directly
3055 * onto the buffer. The value is an sRGB color to use for the background,
3056 * for grayscale output the green channel is used.
3057 *
3058 * background must be supplied when an alpha channel must be removed from a
3059 * single byte color-mapped output format, in other words if:
3060 *
3061 * 1) The original format from png_image_begin_read_from_* had
3062 * PNG_FORMAT_FLAG_ALPHA set.
3063 * 2) The format set by the application does not.
3064 * 3) The format set by the application has PNG_FORMAT_FLAG_COLORMAP set and
3065 * PNG_FORMAT_FLAG_LINEAR *not* set.
3066 *
3067 * For linear output removing the alpha channel is always done by compositing
3068 * on black and background is ignored.
3069 *
3070 * colormap must be supplied when PNG_FORMAT_FLAG_COLORMAP is set. It must
3071 * be at least the size (in bytes) returned by PNG_IMAGE_COLORMAP_SIZE.
3072 * image->colormap_entries will be updated to the actual number of entries
3073 * written to the colormap; this may be less than the original value.
3074 */
3075
3076PNG_EXPORT(238, void, png_image_free, (png_imagep image));
3077 /* Free any data allocated by libpng in image->opaque, setting the pointer to
3078 * NULL. May be called at any time after the structure is initialized.
3079 */
3080#endif /* SIMPLIFIED_READ */
3081
3082#ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED
3083/* WRITE APIS
3084 * ----------
3085 * For write you must initialize a png_image structure to describe the image to
3086 * be written. To do this use memset to set the whole structure to 0 then
3087 * initialize fields describing your image.
3088 *
3089 * version: must be set to PNG_IMAGE_VERSION
3090 * opaque: must be initialized to NULL
3091 * width: image width in pixels
3092 * height: image height in rows
3093 * format: the format of the data (image and color-map) you wish to write
3094 * flags: set to 0 unless one of the defined flags applies; set
3095 * PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB for color format images where the RGB
3096 * values do not correspond to the colors in sRGB.
3097 * colormap_entries: set to the number of entries in the color-map (0 to 256)
3098 */
3099#ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED
3100PNG_EXPORT(239, int, png_image_write_to_file, (png_imagep image,
3101 const char *file, int convert_to_8bit, const void *buffer,
3102 png_int_32 row_stride, const void *colormap));
3103 /* Write the image to the named file. */
3104
3105PNG_EXPORT(240, int, png_image_write_to_stdio, (png_imagep image, FILE *file,
3106 int convert_to_8_bit, const void *buffer, png_int_32 row_stride,
3107 const void *colormap));
3108 /* Write the image to the given (FILE*). */
3109#endif /* SIMPLIFIED_WRITE_STDIO */
3110
3111/* With all write APIs if image is in one of the linear formats with 16-bit
3112 * data then setting convert_to_8_bit will cause the output to be an 8-bit PNG
3113 * gamma encoded according to the sRGB specification, otherwise a 16-bit linear
3114 * encoded PNG file is written.
3115 *
3116 * With color-mapped data formats the colormap parameter point to a color-map
3117 * with at least image->colormap_entries encoded in the specified format. If
3118 * the format is linear the written PNG color-map will be converted to sRGB
3119 * regardless of the convert_to_8_bit flag.
3120 *
3121 * With all APIs row_stride is handled as in the read APIs - it is the spacing
3122 * from one row to the next in component sized units (1 or 2 bytes) and if
3123 * negative indicates a bottom-up row layout in the buffer. If row_stride is
3124 * zero, libpng will calculate it for you from the image width and number of
3125 * channels.
3126 *
3127 * Note that the write API does not support interlacing, sub-8-bit pixels or
3128 * most ancillary chunks. If you need to write text chunks (e.g. for copyright
3129 * notices) you need to use one of the other APIs.
3130 */
3131
3132PNG_EXPORT(245, int, png_image_write_to_memory, (png_imagep image, void *memory,
3133 png_alloc_size_t * PNG_RESTRICT memory_bytes, int convert_to_8_bit,
3134 const void *buffer, png_int_32 row_stride, const void *colormap));
3135 /* Write the image to the given memory buffer. The function both writes the
3136 * whole PNG data stream to *memory and updates *memory_bytes with the count
3137 * of bytes written.
3138 *
3139 * 'memory' may be NULL. In this case *memory_bytes is not read however on
3140 * success the number of bytes which would have been written will still be
3141 * stored in *memory_bytes. On failure *memory_bytes will contain 0.
3142 *
3143 * If 'memory' is not NULL it must point to memory[*memory_bytes] of
3144 * writeable memory.
3145 *
3146 * If the function returns success memory[*memory_bytes] (if 'memory' is not
3147 * NULL) contains the written PNG data. *memory_bytes will always be less
3148 * than or equal to the original value.
3149 *
3150 * If the function returns false and *memory_bytes was not changed an error
3151 * occured during write. If *memory_bytes was changed, or is not 0 if
3152 * 'memory' was NULL, the write would have succeeded but for the memory
3153 * buffer being too small. *memory_bytes contains the required number of
3154 * bytes and will be bigger that the original value.
3155 */
3156
3157#define png_image_write_get_memory_size(image, size, convert_to_8_bit, buffer,\
3158 row_stride, colormap)\
3159 png_image_write_to_memory(&(image), 0, &(size), convert_to_8_bit, buffer,\
3160 row_stride, colormap)
3161 /* Return the amount of memory in 'size' required to compress this image.
3162 * The png_image structure 'image' must be filled in as in the above
3163 * function and must not be changed before the actual write call, the buffer
3164 * and all other parameters must also be identical to that in the final
3165 * write call. The 'size' variable need not be initialized.
3166 *
3167 * NOTE: the macro returns true/false, if false is returned 'size' will be
3168 * set to zero and the write failed and probably will fail if tried again.
3169 */
3170
3171/* You can pre-allocate the buffer by making sure it is of sufficient size
3172 * regardless of the amount of compression achieved. The buffer size will
3173 * always be bigger than the original image and it will never be filled. The
3174 * following macros are provided to assist in allocating the buffer.
3175 */
3176#define PNG_IMAGE_DATA_SIZE(image) (PNG_IMAGE_SIZE(image)+(image).height)
3177 /* The number of uncompressed bytes in the PNG byte encoding of the image;
3178 * uncompressing the PNG IDAT data will give this number of bytes.
3179 *
3180 * NOTE: while PNG_IMAGE_SIZE cannot overflow for an image in memory this
3181 * macro can because of the extra bytes used in the PNG byte encoding. You
3182 * need to avoid this macro if your image size approaches 2^30 in width or
3183 * height. The same goes for the remainder of these macros; they all produce
3184 * bigger numbers than the actual in-memory image size.
3185 */
3186#ifndef PNG_ZLIB_MAX_SIZE
3187# define PNG_ZLIB_MAX_SIZE(b) ((b)+(((b)+7U)>>3)+(((b)+63U)>>6)+11U)
3188 /* An upper bound on the number of compressed bytes given 'b' uncompressed
3189 * bytes. This is based on deflateBounds() in zlib; different
3190 * implementations of zlib compression may conceivably produce more data so
3191 * if your zlib implementation is not zlib itself redefine this macro
3192 * appropriately.
3193 */
3194#endif
3195
3196#define PNG_IMAGE_COMPRESSED_SIZE_MAX(image)\
3197 PNG_ZLIB_MAX_SIZE((png_alloc_size_t)PNG_IMAGE_DATA_SIZE(image))
3198 /* An upper bound on the size of the data in the PNG IDAT chunks. */
3199
3200#define PNG_IMAGE_PNG_SIZE_MAX_(image, image_size)\
3201 ((8U/*sig*/+25U/*IHDR*/+16U/*gAMA*/+44U/*cHRM*/+12U/*IEND*/+\
3202 (((image).format&PNG_FORMAT_FLAG_COLORMAP)?/*colormap: PLTE, tRNS*/\
3203 12U+3U*(image).colormap_entries/*PLTE data*/+\
3204 (((image).format&PNG_FORMAT_FLAG_ALPHA)?\
3205 12U/*tRNS*/+(image).colormap_entries:0U):0U)+\
3206 12U)+(12U*((image_size)/PNG_ZBUF_SIZE))/*IDAT*/+(image_size))
3207 /* A helper for the following macro; if your compiler cannot handle the
3208 * following macro use this one with the result of
3209 * PNG_IMAGE_COMPRESSED_SIZE_MAX(image) as the second argument (most
3210 * compilers should handle this just fine.)
3211 */
3212
3213#define PNG_IMAGE_PNG_SIZE_MAX(image)\
3214 PNG_IMAGE_PNG_SIZE_MAX_(image, PNG_IMAGE_COMPRESSED_SIZE_MAX(image))
3215 /* An upper bound on the total length of the PNG data stream for 'image'.
3216 * The result is of type png_alloc_size_t, on 32-bit systems this may
3217 * overflow even though PNG_IMAGE_DATA_SIZE does not overflow; the write will
3218 * run out of buffer space but return a corrected size which should work.
3219 */
3220#endif /* SIMPLIFIED_WRITE */
3221/*******************************************************************************
3222 * END OF SIMPLIFIED API
3223 ******************************************************************************/
3224#endif /* SIMPLIFIED_{READ|WRITE} */
3225
3226/*******************************************************************************
3227 * Section 6: IMPLEMENTATION OPTIONS
3228 *******************************************************************************
3229 *
3230 * Support for arbitrary implementation-specific optimizations. The API allows
3231 * particular options to be turned on or off. 'Option' is the number of the
3232 * option and 'onoff' is 0 (off) or non-0 (on). The value returned is given
3233 * by the PNG_OPTION_ defines below.
3234 *
3235 * HARDWARE: normally hardware capabilites, such as the Intel SSE instructions,
3236 * are detected at run time, however sometimes it may be impossible
3237 * to do this in user mode, in which case it is necessary to discover
3238 * the capabilities in an OS specific way. Such capabilities are
3239 * listed here when libpng has support for them and must be turned
3240 * ON by the application if present.
3241 *
3242 * SOFTWARE: sometimes software optimizations actually result in performance
3243 * decrease on some architectures or systems, or with some sets of
3244 * PNG images. 'Software' options allow such optimizations to be
3245 * selected at run time.
3246 */
3247#ifdef PNG_SET_OPTION_SUPPORTED
3248#ifdef PNG_ARM_NEON_API_SUPPORTED
3249# define PNG_ARM_NEON 0 /* HARDWARE: ARM Neon SIMD instructions supported */
3250#endif
3251#define PNG_MAXIMUM_INFLATE_WINDOW 2 /* SOFTWARE: force maximum window */
3252#define PNG_SKIP_sRGB_CHECK_PROFILE 4 /* SOFTWARE: Check ICC profile for sRGB */
3253#ifdef PNG_MIPS_MSA_API_SUPPORTED
3254# define PNG_MIPS_MSA 6 /* HARDWARE: MIPS Msa SIMD instructions supported */
3255#endif
3256#define PNG_OPTION_NEXT 8 /* Next option - numbers must be even */
3257
3258/* Return values: NOTE: there are four values and 'off' is *not* zero */
3259#define PNG_OPTION_UNSET 0 /* Unset - defaults to off */
3260#define PNG_OPTION_INVALID 1 /* Option number out of range */
3261#define PNG_OPTION_OFF 2
3262#define PNG_OPTION_ON 3
3263
3264PNG_EXPORT(244, int, png_set_option, (png_structrp png_ptr, int option,
3265 int onoff));
3266#endif /* SET_OPTION */
3267
3268/*******************************************************************************
3269 * END OF HARDWARE AND SOFTWARE OPTIONS
3270 ******************************************************************************/
3271#ifdef PNG_APNG_SUPPORTED
3272PNG_EXPORT(246, png_uint_32, png_get_acTL, (png_structp png_ptr,
3273 png_infop info_ptr, png_uint_32 *num_frames, png_uint_32 *num_plays));
3274
3275PNG_EXPORT(247, png_uint_32, png_set_acTL, (png_structp png_ptr,
3276 png_infop info_ptr, png_uint_32 num_frames, png_uint_32 num_plays));
3277
3278PNG_EXPORT(248, png_uint_32, png_get_num_frames, (png_structp png_ptr,
3279 png_infop info_ptr));
3280
3281PNG_EXPORT(249, png_uint_32, png_get_num_plays, (png_structp png_ptr,
3282 png_infop info_ptr));
3283
3284PNG_EXPORT(250, png_uint_32, png_get_next_frame_fcTL,
3285 (png_structp png_ptr, png_infop info_ptr, png_uint_32 *width,
3286 png_uint_32 *height, png_uint_32 *x_offset, png_uint_32 *y_offset,
3287 png_uint_16 *delay_num, png_uint_16 *delay_den, png_byte *dispose_op,
3288 png_byte *blend_op));
3289
3290PNG_EXPORT(251, png_uint_32, png_set_next_frame_fcTL,
3291 (png_structp png_ptr, png_infop info_ptr, png_uint_32 width,
3292 png_uint_32 height, png_uint_32 x_offset, png_uint_32 y_offset,
3293 png_uint_16 delay_num, png_uint_16 delay_den, png_byte dispose_op,
3294 png_byte blend_op));
3295
3296PNG_EXPORT(252, png_uint_32, png_get_next_frame_width,
3297 (png_structp png_ptr, png_infop info_ptr));
3298PNG_EXPORT(253, png_uint_32, png_get_next_frame_height,
3299 (png_structp png_ptr, png_infop info_ptr));
3300PNG_EXPORT(254, png_uint_32, png_get_next_frame_x_offset,
3301 (png_structp png_ptr, png_infop info_ptr));
3302PNG_EXPORT(255, png_uint_32, png_get_next_frame_y_offset,
3303 (png_structp png_ptr, png_infop info_ptr));
3304PNG_EXPORT(256, png_uint_16, png_get_next_frame_delay_num,
3305 (png_structp png_ptr, png_infop info_ptr));
3306PNG_EXPORT(257, png_uint_16, png_get_next_frame_delay_den,
3307 (png_structp png_ptr, png_infop info_ptr));
3308PNG_EXPORT(258, png_byte, png_get_next_frame_dispose_op,
3309 (png_structp png_ptr, png_infop info_ptr));
3310PNG_EXPORT(259, png_byte, png_get_next_frame_blend_op,
3311 (png_structp png_ptr, png_infop info_ptr));
3312PNG_EXPORT(260, png_byte, png_get_first_frame_is_hidden,
3313 (png_structp png_ptr, png_infop info_ptr));
3314PNG_EXPORT(261, png_uint_32, png_set_first_frame_is_hidden,
3315 (png_structp png_ptr, png_infop info_ptr, png_byte is_hidden));
3316
3317#ifdef PNG_READ_APNG_SUPPORTED
3318PNG_EXPORT(262, void, png_read_frame_head, (png_structp png_ptr,
3319 png_infop info_ptr));
3320#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
3321PNG_EXPORT(263, void, png_set_progressive_frame_fn, (png_structp png_ptr,
3322 png_progressive_frame_ptr frame_info_fn,
3323 png_progressive_frame_ptr frame_end_fn));
3324#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
3325#endif /* PNG_READ_APNG_SUPPORTED */
3326
3327#ifdef PNG_WRITE_APNG_SUPPORTED
3328PNG_EXPORT(264, void, png_write_frame_head, (png_structp png_ptr,
3329 png_infop info_ptr, png_bytepp row_pointers,
3330 png_uint_32 width, png_uint_32 height,
3331 png_uint_32 x_offset, png_uint_32 y_offset,
3332 png_uint_16 delay_num, png_uint_16 delay_den, png_byte dispose_op,
3333 png_byte blend_op));
3334
3335PNG_EXPORT(265, void, png_write_frame_tail, (png_structp png_ptr,
3336 png_infop info_ptr));
3337#endif /* PNG_WRITE_APNG_SUPPORTED */
3338#endif /* PNG_APNG_SUPPORTED */
3339
3340/* Maintainer: Put new public prototypes here ^, in libpng.3, in project
3341 * defs, and in scripts/symbols.def.
3342 */
3343
3344/* The last ordinal number (this is the *last* one already used; the next
3345 * one to use is one more than this.)
3346 */
3347#ifdef PNG_EXPORT_LAST_ORDINAL
3348#ifdef PNG_APNG_SUPPORTED
3349 PNG_EXPORT_LAST_ORDINAL(265);
3350#else
3351 PNG_EXPORT_LAST_ORDINAL(245);
3352#endif /* PNG_APNG_SUPPORTED */
3353#endif
3354
3355#ifdef __cplusplus
3356}
3357#endif
3358
3359#endif /* PNG_VERSION_INFO_ONLY */
3360/* Do not put anything past this line */
3361#endif /* PNG_H */
3362