1/* png.h - header file for PNG reference library
2 *
3 * libpng version 1.6.55
4 *
5 * Copyright (c) 2018-2026 Cosmin Truta
6 * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
7 * Copyright (c) 1996-1997 Andreas Dilger
8 * 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 1.6.35, July 2018:
16 * Glenn Randers-Pehrson
17 * libpng versions 1.6.36, December 2018, through 1.6.55, February 2026:
18 * Cosmin Truta
19 * See also "Contributing Authors", below.
20 */
21
22/*
23 * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE
24 * =========================================
25 *
26 * PNG Reference Library License version 2
27 * ---------------------------------------
28 *
29 * * Copyright (c) 1995-2026 The PNG Reference Library Authors.
30 * * Copyright (c) 2018-2026 Cosmin Truta.
31 * * Copyright (c) 2000-2002, 2004, 2006-2018 Glenn Randers-Pehrson.
32 * * Copyright (c) 1996-1997 Andreas Dilger.
33 * * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
34 *
35 * The software is supplied "as is", without warranty of any kind,
36 * express or implied, including, without limitation, the warranties
37 * of merchantability, fitness for a particular purpose, title, and
38 * non-infringement. In no event shall the Copyright owners, or
39 * anyone distributing the software, be liable for any damages or
40 * other liability, whether in contract, tort or otherwise, arising
41 * from, out of, or in connection with the software, or the use or
42 * other dealings in the software, even if advised of the possibility
43 * of such damage.
44 *
45 * Permission is hereby granted to use, copy, modify, and distribute
46 * this software, or portions hereof, for any purpose, without fee,
47 * subject to the following restrictions:
48 *
49 * 1. The origin of this software must not be misrepresented; you
50 * must not claim that you wrote the original software. If you
51 * use this software in a product, an acknowledgment in the product
52 * documentation would be appreciated, but is not required.
53 *
54 * 2. Altered source versions must be plainly marked as such, and must
55 * not be misrepresented as being the original software.
56 *
57 * 3. This Copyright notice may not be removed or altered from any
58 * source or altered source distribution.
59 *
60 *
61 * PNG Reference Library License version 1 (for libpng 0.5 through 1.6.35)
62 * -----------------------------------------------------------------------
63 *
64 * libpng versions 1.0.7, July 1, 2000, through 1.6.35, July 15, 2018 are
65 * Copyright (c) 2000-2002, 2004, 2006-2018 Glenn Randers-Pehrson, are
66 * derived from libpng-1.0.6, and are distributed according to the same
67 * disclaimer and license as libpng-1.0.6 with the following individuals
68 * added to the list of Contributing Authors:
69 *
70 * Simon-Pierre Cadieux
71 * Eric S. Raymond
72 * Mans Rullgard
73 * Cosmin Truta
74 * Gilles Vollant
75 * James Yu
76 * Mandar Sahastrabuddhe
77 * Google Inc.
78 * Vadim Barkov
79 *
80 * and with the following additions to the disclaimer:
81 *
82 * There is no warranty against interference with your enjoyment of
83 * the library or against infringement. There is no warranty that our
84 * efforts or the library will fulfill any of your particular purposes
85 * or needs. This library is provided with all faults, and the entire
86 * risk of satisfactory quality, performance, accuracy, and effort is
87 * with the user.
88 *
89 * Some files in the "contrib" directory and some configure-generated
90 * files that are distributed with libpng have other copyright owners, and
91 * are released under other open source licenses.
92 *
93 * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
94 * Copyright (c) 1998-2000 Glenn Randers-Pehrson, are derived from
95 * libpng-0.96, and are distributed according to the same disclaimer and
96 * license as libpng-0.96, with the following individuals added to the
97 * list of Contributing Authors:
98 *
99 * Tom Lane
100 * Glenn Randers-Pehrson
101 * Willem van Schaik
102 *
103 * libpng versions 0.89, June 1996, through 0.96, May 1997, are
104 * Copyright (c) 1996-1997 Andreas Dilger, are derived from libpng-0.88,
105 * and are distributed according to the same disclaimer and license as
106 * libpng-0.88, with the following individuals added to the list of
107 * Contributing Authors:
108 *
109 * John Bowler
110 * Kevin Bracey
111 * Sam Bushell
112 * Magnus Holmgren
113 * Greg Roelofs
114 * Tom Tanner
115 *
116 * Some files in the "scripts" directory have other copyright owners,
117 * but are released under this license.
118 *
119 * libpng versions 0.5, May 1995, through 0.88, January 1996, are
120 * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
121 *
122 * For the purposes of this copyright and license, "Contributing Authors"
123 * is defined as the following set of individuals:
124 *
125 * Andreas Dilger
126 * Dave Martindale
127 * Guy Eric Schalnat
128 * Paul Schmidt
129 * Tim Wegner
130 *
131 * The PNG Reference Library is supplied "AS IS". The Contributing
132 * Authors and Group 42, Inc. disclaim all warranties, expressed or
133 * implied, including, without limitation, the warranties of
134 * merchantability and of fitness for any purpose. The Contributing
135 * Authors and Group 42, Inc. assume no liability for direct, indirect,
136 * incidental, special, exemplary, or consequential damages, which may
137 * result from the use of the PNG Reference Library, even if advised of
138 * the possibility of such damage.
139 *
140 * Permission is hereby granted to use, copy, modify, and distribute this
141 * source code, or portions hereof, for any purpose, without fee, subject
142 * to the following restrictions:
143 *
144 * 1. The origin of this source code must not be misrepresented.
145 *
146 * 2. Altered versions must be plainly marked as such and must not
147 * be misrepresented as being the original source.
148 *
149 * 3. This Copyright notice may not be removed or altered from any
150 * source or altered source distribution.
151 *
152 * The Contributing Authors and Group 42, Inc. specifically permit,
153 * without fee, and encourage the use of this source code as a component
154 * to supporting the PNG file format in commercial products. If you use
155 * this source code in a product, acknowledgment is not required but would
156 * be appreciated.
157 *
158 * END OF COPYRIGHT NOTICE, DISCLAIMER, and LICENSE.
159 *
160 * TRADEMARK
161 * =========
162 *
163 * The name "libpng" has not been registered by the Copyright owners
164 * as a trademark in any jurisdiction. However, because libpng has
165 * been distributed and maintained world-wide, continually since 1995,
166 * the Copyright owners claim "common-law trademark protection" in any
167 * jurisdiction where common-law trademark is recognized.
168 */
169
170/*
171 * A "png_get_copyright" function is available, for convenient use in "about"
172 * boxes and the like:
173 *
174 * printf("%s", png_get_copyright(NULL));
175 *
176 * Also, the PNG logo (in PNG format, of course) is supplied in the
177 * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
178 */
179
180/*
181 * The contributing authors would like to thank all those who helped
182 * with testing, bug fixes, and patience. This wouldn't have been
183 * possible without all of you.
184 *
185 * Thanks to Frank J. T. Wojcik for helping with the documentation.
186 */
187
188/* Note about libpng version numbers:
189 *
190 * Due to various miscommunications, unforeseen code incompatibilities
191 * and occasional factors outside the authors' control, version numbering
192 * on the library has not always been consistent and straightforward.
193 * The following table summarizes matters since version 0.89c, which was
194 * the first widely used release:
195 *
196 * source png.h png.h shared-lib
197 * version string int version
198 * ------- ------ ----- ----------
199 * 0.89c "1.0 beta 3" 0.89 89 1.0.89
200 * 0.90 "1.0 beta 4" 0.90 90 0.90 [should have been 2.0.90]
201 * 0.95 "1.0 beta 5" 0.95 95 0.95 [should have been 2.0.95]
202 * 0.96 "1.0 beta 6" 0.96 96 0.96 [should have been 2.0.96]
203 * 0.97b "1.00.97 beta 7" 1.00.97 97 1.0.1 [should have been 2.0.97]
204 * 0.97c 0.97 97 2.0.97
205 * 0.98 0.98 98 2.0.98
206 * 0.99 0.99 98 2.0.99
207 * 0.99a-m 0.99 99 2.0.99
208 * 1.00 1.00 100 2.1.0 [100 should be 10000]
209 * 1.0.0 (from here on, the 100 2.1.0 [100 should be 10000]
210 * 1.0.1 png.h string is 10001 2.1.0
211 * 1.0.1a-e identical to the 10002 from here on, the shared library
212 * 1.0.2 source version) 10002 is 2.V where V is the source code
213 * 1.0.2a-b 10003 version, except as noted.
214 * 1.0.3 10003
215 * 1.0.3a-d 10004
216 * 1.0.4 10004
217 * 1.0.4a-f 10005
218 * 1.0.5 (+ 2 patches) 10005
219 * 1.0.5a-d 10006
220 * 1.0.5e-r 10100 (not source compatible)
221 * 1.0.5s-v 10006 (not binary compatible)
222 * 1.0.6 (+ 3 patches) 10006 (still binary incompatible)
223 * 1.0.6d-f 10007 (still binary incompatible)
224 * 1.0.6g 10007
225 * 1.0.6h 10007 10.6h (testing xy.z so-numbering)
226 * 1.0.6i 10007 10.6i
227 * 1.0.6j 10007 2.1.0.6j (incompatible with 1.0.0)
228 * 1.0.7beta11-14 DLLNUM 10007 2.1.0.7beta11-14 (binary compatible)
229 * 1.0.7beta15-18 1 10007 2.1.0.7beta15-18 (binary compatible)
230 * 1.0.7rc1-2 1 10007 2.1.0.7rc1-2 (binary compatible)
231 * 1.0.7 1 10007 (still compatible)
232 * ...
233 * 1.0.69 10 10069 10.so.0.69[.0]
234 * ...
235 * 1.2.59 13 10259 12.so.0.59[.0]
236 * ...
237 * 1.4.20 14 10420 14.so.0.20[.0]
238 * ...
239 * 1.5.30 15 10530 15.so.15.30[.0]
240 * ...
241 * 1.6.55 16 10655 16.so.16.55[.0]
242 *
243 * Henceforth the source version will match the shared-library major and
244 * minor numbers; the shared-library major version number will be used for
245 * changes in backward compatibility, as it is intended.
246 * The PNG_LIBPNG_VER macro, which is not used within libpng but is
247 * available for applications, is an unsigned integer of the form XYYZZ
248 * corresponding to the source version X.Y.Z (leading zeros in Y and Z).
249 * Beta versions were given the previous public release number plus a
250 * letter, until version 1.0.6j; from then on they were given the upcoming
251 * public release number plus "betaNN" or "rcNN".
252 *
253 * Binary incompatibility exists only when applications make direct access
254 * to the info_ptr or png_ptr members through png.h, and the compiled
255 * application is loaded with a different version of the library.
256 *
257 * See libpng.txt or libpng.3 for more information. The PNG specification
258 * is available as a W3C Recommendation and as an ISO/IEC Standard; see
259 * <https://www.w3.org/TR/2003/REC-PNG-20031110/>
260 */
261
262#ifndef PNG_H
263#define PNG_H
264
265/* This is not the place to learn how to use libpng. The file libpng-manual.txt
266 * describes how to use libpng, and the file example.c summarizes it
267 * with some code on which to build. This file is useful for looking
268 * at the actual function definitions and structure components. If that
269 * file has been stripped from your copy of libpng, you can find it at
270 * <http://www.libpng.org/pub/png/libpng-manual.txt>
271 *
272 * If you just need to read a PNG file and don't want to read the documentation
273 * skip to the end of this file and read the section entitled 'simplified API'.
274 */
275
276/* Version information for png.h - this should match the version in png.c */
277#define PNG_LIBPNG_VER_STRING "1.6.55"
278#define PNG_HEADER_VERSION_STRING " libpng version " PNG_LIBPNG_VER_STRING "\n"
279
280/* The versions of shared library builds should stay in sync, going forward */
281#define PNG_LIBPNG_VER_SHAREDLIB 16
282#define PNG_LIBPNG_VER_SONUM PNG_LIBPNG_VER_SHAREDLIB /* [Deprecated] */
283#define PNG_LIBPNG_VER_DLLNUM PNG_LIBPNG_VER_SHAREDLIB /* [Deprecated] */
284
285/* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
286#define PNG_LIBPNG_VER_MAJOR 1
287#define PNG_LIBPNG_VER_MINOR 6
288#define PNG_LIBPNG_VER_RELEASE 55
289
290/* This should be zero for a public release, or non-zero for a
291 * development version.
292 */
293#define PNG_LIBPNG_VER_BUILD 0
294
295/* Release Status */
296#define PNG_LIBPNG_BUILD_ALPHA 1
297#define PNG_LIBPNG_BUILD_BETA 2
298#define PNG_LIBPNG_BUILD_RC 3
299#define PNG_LIBPNG_BUILD_STABLE 4
300#define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7
301
302/* Release-Specific Flags */
303#define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with
304 PNG_LIBPNG_BUILD_STABLE only */
305#define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with
306 PNG_LIBPNG_BUILD_SPECIAL */
307#define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with
308 PNG_LIBPNG_BUILD_PRIVATE */
309
310#define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE
311
312/* Careful here. At one time, Guy wanted to use 082, but that
313 * would be octal. We must not include leading zeros.
314 * Versions 0.7 through 1.0.0 were in the range 0 to 100 here
315 * (only version 1.0.0 was mis-numbered 100 instead of 10000).
316 * From version 1.0.1 it is:
317 * XXYYZZ, where XX=major, YY=minor, ZZ=release
318 */
319#define PNG_LIBPNG_VER 10655 /* 1.6.55 */
320
321/* Library configuration: these options cannot be changed after
322 * the library has been built.
323 */
324#ifndef PNGLCONF_H
325/* If pnglibconf.h is missing, you can
326 * copy scripts/pnglibconf.h.prebuilt to pnglibconf.h
327 */
328# include "pnglibconf.h"
329#endif
330
331#ifndef PNG_VERSION_INFO_ONLY
332/* Machine specific configuration. */
333# include "pngconf.h"
334#endif
335
336/*
337 * Added at libpng-1.2.8
338 *
339 * Ref MSDN: Private as priority over Special
340 * VS_FF_PRIVATEBUILD File *was not* built using standard release
341 * procedures. If this value is given, the StringFileInfo block must
342 * contain a PrivateBuild string.
343 *
344 * VS_FF_SPECIALBUILD File *was* built by the original company using
345 * standard release procedures but is a variation of the standard
346 * file of the same version number. If this value is given, the
347 * StringFileInfo block must contain a SpecialBuild string.
348 */
349
350#ifdef PNG_USER_PRIVATEBUILD /* From pnglibconf.h */
351# define PNG_LIBPNG_BUILD_TYPE \
352 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE)
353#else
354# ifdef PNG_LIBPNG_SPECIALBUILD
355# define PNG_LIBPNG_BUILD_TYPE \
356 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL)
357# else
358# define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE)
359# endif
360#endif
361
362#ifndef PNG_VERSION_INFO_ONLY
363
364/* Inhibit C++ name-mangling for libpng functions but not for system calls. */
365#ifdef __cplusplus
366extern "C" {
367#endif /* __cplusplus */
368
369/* Version information for C files, stored in png.c. This had better match
370 * the version above.
371 */
372#define png_libpng_ver png_get_header_ver(NULL)
373
374/* This file is arranged in several sections:
375 *
376 * 1. [omitted]
377 * 2. Any configuration options that can be specified by for the application
378 * code when it is built. (Build time configuration is in pnglibconf.h)
379 * 3. Type definitions (base types are defined in pngconf.h), structure
380 * definitions.
381 * 4. Exported library functions.
382 * 5. Simplified API.
383 * 6. Implementation options.
384 *
385 * The library source code has additional files (principally pngpriv.h) that
386 * allow configuration of the library.
387 */
388
389/* Section 1: [omitted] */
390
391/* Section 2: run time configuration
392 * See pnglibconf.h for build time configuration
393 *
394 * Run time configuration allows the application to choose between
395 * implementations of certain arithmetic APIs. The default is set
396 * at build time and recorded in pnglibconf.h, but it is safe to
397 * override these (and only these) settings. Note that this won't
398 * change what the library does, only application code, and the
399 * settings can (and probably should) be made on a per-file basis
400 * by setting the #defines before including png.h
401 *
402 * Use macros to read integers from PNG data or use the exported
403 * functions?
404 * PNG_USE_READ_MACROS: use the macros (see below) Note that
405 * the macros evaluate their argument multiple times.
406 * PNG_NO_USE_READ_MACROS: call the relevant library function.
407 *
408 * Use the alternative algorithm for compositing alpha samples that
409 * does not use division?
410 * PNG_READ_COMPOSITE_NODIV_SUPPORTED: use the 'no division'
411 * algorithm.
412 * PNG_NO_READ_COMPOSITE_NODIV: use the 'division' algorithm.
413 *
414 * How to handle benign errors if PNG_ALLOW_BENIGN_ERRORS is
415 * false?
416 * PNG_ALLOW_BENIGN_ERRORS: map calls to the benign error
417 * APIs to png_warning.
418 * Otherwise the calls are mapped to png_error.
419 */
420
421/* Section 3: type definitions, including structures and compile time
422 * constants.
423 * See pngconf.h for base types that vary by machine/system
424 */
425
426/* This triggers a compiler error in png.c, if png.c and png.h
427 * do not agree upon the version number.
428 */
429typedef char *png_libpng_version_1_6_55;
430
431/* Basic control structions. Read libpng-manual.txt or libpng.3 for more info.
432 *
433 * png_struct is the cache of information used while reading or writing a single
434 * PNG file. One of these is always required, although the simplified API
435 * (below) hides the creation and destruction of it.
436 */
437typedef struct png_struct_def png_struct;
438typedef const png_struct * png_const_structp;
439typedef png_struct * png_structp;
440typedef png_struct * * png_structpp;
441
442/* png_info contains information read from or to be written to a PNG file. One
443 * or more of these must exist while reading or creating a PNG file. The
444 * information is not used by libpng during read but is used to control what
445 * gets written when a PNG file is created. "png_get_" function calls read
446 * information during read and "png_set_" functions calls write information
447 * when creating a PNG.
448 * been moved into a separate header file that is not accessible to
449 * applications. Read libpng-manual.txt or libpng.3 for more info.
450 */
451typedef struct png_info_def png_info;
452typedef png_info * png_infop;
453typedef const png_info * png_const_infop;
454typedef png_info * * png_infopp;
455
456/* Types with names ending 'p' are pointer types. The corresponding types with
457 * names ending 'rp' are identical pointer types except that the pointer is
458 * marked 'restrict', which means that it is the only pointer to the object
459 * passed to the function. Applications should not use the 'restrict' types;
460 * it is always valid to pass 'p' to a pointer with a function argument of the
461 * corresponding 'rp' type. Different compilers have different rules with
462 * regard to type matching in the presence of 'restrict'. For backward
463 * compatibility libpng callbacks never have 'restrict' in their parameters and,
464 * consequentially, writing portable application code is extremely difficult if
465 * an attempt is made to use 'restrict'.
466 */
467typedef png_struct * PNG_RESTRICT png_structrp;
468typedef const png_struct * PNG_RESTRICT png_const_structrp;
469typedef png_info * PNG_RESTRICT png_inforp;
470typedef const png_info * PNG_RESTRICT png_const_inforp;
471
472/* Three color definitions. The order of the red, green, and blue, (and the
473 * exact size) is not important, although the size of the fields need to
474 * be png_byte or png_uint_16 (as defined below).
475 */
476typedef struct png_color_struct
477{
478 png_byte red;
479 png_byte green;
480 png_byte blue;
481} png_color;
482typedef png_color * png_colorp;
483typedef const png_color * png_const_colorp;
484typedef png_color * * png_colorpp;
485
486typedef struct png_color_16_struct
487{
488 png_byte index; /* used for palette files */
489 png_uint_16 red; /* for use in red green blue files */
490 png_uint_16 green;
491 png_uint_16 blue;
492 png_uint_16 gray; /* for use in grayscale files */
493} png_color_16;
494typedef png_color_16 * png_color_16p;
495typedef const png_color_16 * png_const_color_16p;
496typedef png_color_16 * * png_color_16pp;
497
498typedef struct png_color_8_struct
499{
500 png_byte red; /* for use in red green blue files */
501 png_byte green;
502 png_byte blue;
503 png_byte gray; /* for use in grayscale files */
504 png_byte alpha; /* for alpha channel files */
505} png_color_8;
506typedef png_color_8 * png_color_8p;
507typedef const png_color_8 * png_const_color_8p;
508typedef png_color_8 * * png_color_8pp;
509
510/*
511 * The following two structures are used for the in-core representation
512 * of sPLT chunks.
513 */
514typedef struct png_sPLT_entry_struct
515{
516 png_uint_16 red;
517 png_uint_16 green;
518 png_uint_16 blue;
519 png_uint_16 alpha;
520 png_uint_16 frequency;
521} png_sPLT_entry;
522typedef png_sPLT_entry * png_sPLT_entryp;
523typedef const png_sPLT_entry * png_const_sPLT_entryp;
524typedef png_sPLT_entry * * png_sPLT_entrypp;
525
526/* When the depth of the sPLT palette is 8 bits, the color and alpha samples
527 * occupy the LSB of their respective members, and the MSB of each member
528 * is zero-filled. The frequency member always occupies the full 16 bits.
529 */
530
531typedef struct png_sPLT_struct
532{
533 png_charp name; /* palette name */
534 png_byte depth; /* depth of palette samples */
535 png_sPLT_entryp entries; /* palette entries */
536 png_int_32 nentries; /* number of palette entries */
537} png_sPLT_t;
538typedef png_sPLT_t * png_sPLT_tp;
539typedef const png_sPLT_t * png_const_sPLT_tp;
540typedef png_sPLT_t * * png_sPLT_tpp;
541
542#ifdef PNG_TEXT_SUPPORTED
543/* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,
544 * and whether that contents is compressed or not. The "key" field
545 * points to a regular zero-terminated C string. The "text" fields can be a
546 * regular C string, an empty string, or a NULL pointer.
547 * However, the structure returned by png_get_text() will always contain
548 * the "text" field as a regular zero-terminated C string (possibly
549 * empty), never a NULL pointer, so it can be safely used in printf() and
550 * other string-handling functions. Note that the "itxt_length", "lang", and
551 * "lang_key" members of the structure only exist when the library is built
552 * with iTXt chunk support. Prior to libpng-1.4.0 the library was built by
553 * default without iTXt support. Also note that when iTXt *is* supported,
554 * the "lang" and "lang_key" fields contain NULL pointers when the
555 * "compression" field contains * PNG_TEXT_COMPRESSION_NONE or
556 * PNG_TEXT_COMPRESSION_zTXt. Note that the "compression value" is not the
557 * same as what appears in the PNG tEXt/zTXt/iTXt chunk's "compression flag"
558 * which is always 0 or 1, or its "compression method" which is always 0.
559 */
560typedef struct png_text_struct
561{
562 int compression; /* compression value:
563 -1: tEXt, none
564 0: zTXt, deflate
565 1: iTXt, none
566 2: iTXt, deflate */
567 png_charp key; /* keyword, 1-79 character description of "text" */
568 png_charp text; /* comment, may be an empty string (ie "")
569 or a NULL pointer */
570 size_t text_length; /* length of the text string */
571 size_t itxt_length; /* length of the itxt string */
572 png_charp lang; /* language code, 0-79 characters
573 or a NULL pointer */
574 png_charp lang_key; /* keyword translated UTF-8 string, 0 or more
575 chars or a NULL pointer */
576} png_text;
577typedef png_text * png_textp;
578typedef const png_text * png_const_textp;
579typedef png_text * * png_textpp;
580#endif
581
582/* Supported compression types for text in PNG files (tEXt, and zTXt).
583 * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */
584#define PNG_TEXT_COMPRESSION_NONE_WR -3
585#define PNG_TEXT_COMPRESSION_zTXt_WR -2
586#define PNG_TEXT_COMPRESSION_NONE -1
587#define PNG_TEXT_COMPRESSION_zTXt 0
588#define PNG_ITXT_COMPRESSION_NONE 1
589#define PNG_ITXT_COMPRESSION_zTXt 2
590#define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */
591
592/* png_time is a way to hold the time in an machine independent way.
593 * Two conversions are provided, both from time_t and struct tm. There
594 * is no portable way to convert to either of these structures, as far
595 * as I know. If you know of a portable way, send it to me. As a side
596 * note - PNG has always been Year 2000 compliant!
597 */
598typedef struct png_time_struct
599{
600 png_uint_16 year; /* full year, as in, 1995 */
601 png_byte month; /* month of year, 1 - 12 */
602 png_byte day; /* day of month, 1 - 31 */
603 png_byte hour; /* hour of day, 0 - 23 */
604 png_byte minute; /* minute of hour, 0 - 59 */
605 png_byte second; /* second of minute, 0 - 60 (for leap seconds) */
606} png_time;
607typedef png_time * png_timep;
608typedef const png_time * png_const_timep;
609typedef png_time * * png_timepp;
610
611#if defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) ||\
612 defined(PNG_USER_CHUNKS_SUPPORTED)
613/* png_unknown_chunk is a structure to hold queued chunks for which there is
614 * no specific support. The idea is that we can use this to queue
615 * up private chunks for output even though the library doesn't actually
616 * know about their semantics.
617 *
618 * The data in the structure is set by libpng on read and used on write.
619 */
620typedef struct png_unknown_chunk_t
621{
622 png_byte name[5]; /* Textual chunk name with '\0' terminator */
623 png_byte *data; /* Data, should not be modified on read! */
624 size_t size;
625
626 /* On write 'location' must be set using the flag values listed below.
627 * Notice that on read it is set by libpng however the values stored have
628 * more bits set than are listed below. Always treat the value as a
629 * bitmask. On write set only one bit - setting multiple bits may cause the
630 * chunk to be written in multiple places.
631 */
632 png_byte location; /* mode of operation at read time */
633}
634png_unknown_chunk;
635
636typedef png_unknown_chunk * png_unknown_chunkp;
637typedef const png_unknown_chunk * png_const_unknown_chunkp;
638typedef png_unknown_chunk * * png_unknown_chunkpp;
639#endif
640
641/* Flag values for the unknown chunk location byte. */
642#define PNG_HAVE_IHDR 0x01
643#define PNG_HAVE_PLTE 0x02
644#define PNG_AFTER_IDAT 0x08
645
646/* Maximum positive integer used in PNG is (2^31)-1 */
647#define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL)
648#define PNG_UINT_32_MAX ((png_uint_32)(-1))
649#define PNG_SIZE_MAX ((size_t)(-1))
650
651/* These are constants for fixed point values encoded in the
652 * PNG specification manner (x100000)
653 */
654#define PNG_FP_1 100000
655#define PNG_FP_HALF 50000
656#define PNG_FP_MAX ((png_fixed_point)0x7fffffffL)
657#define PNG_FP_MIN (-PNG_FP_MAX)
658
659/* These describe the color_type field in png_info. */
660/* color type masks */
661#define PNG_COLOR_MASK_PALETTE 1
662#define PNG_COLOR_MASK_COLOR 2
663#define PNG_COLOR_MASK_ALPHA 4
664
665/* color types. Note that not all combinations are legal */
666#define PNG_COLOR_TYPE_GRAY 0
667#define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
668#define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR)
669#define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
670#define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
671/* aliases */
672#define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA
673#define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA
674
675/* This is for compression type. PNG 1.0-1.2 only define the single type. */
676#define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */
677#define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE
678
679/* This is for filter type. PNG 1.0-1.2 only define the single type. */
680#define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */
681#define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */
682#define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE
683
684/* These are for the interlacing type. These values should NOT be changed. */
685#define PNG_INTERLACE_NONE 0 /* Non-interlaced image */
686#define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */
687#define PNG_INTERLACE_LAST 2 /* Not a valid value */
688
689/* These are for the oFFs chunk. These values should NOT be changed. */
690#define PNG_OFFSET_PIXEL 0 /* Offset in pixels */
691#define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */
692#define PNG_OFFSET_LAST 2 /* Not a valid value */
693
694/* These are for the pCAL chunk. These values should NOT be changed. */
695#define PNG_EQUATION_LINEAR 0 /* Linear transformation */
696#define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */
697#define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */
698#define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */
699#define PNG_EQUATION_LAST 4 /* Not a valid value */
700
701/* These are for the sCAL chunk. These values should NOT be changed. */
702#define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */
703#define PNG_SCALE_METER 1 /* meters per pixel */
704#define PNG_SCALE_RADIAN 2 /* radians per pixel */
705#define PNG_SCALE_LAST 3 /* Not a valid value */
706
707/* These are for the pHYs chunk. These values should NOT be changed. */
708#define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */
709#define PNG_RESOLUTION_METER 1 /* pixels/meter */
710#define PNG_RESOLUTION_LAST 2 /* Not a valid value */
711
712/* These are for the sRGB chunk. These values should NOT be changed. */
713#define PNG_sRGB_INTENT_PERCEPTUAL 0
714#define PNG_sRGB_INTENT_RELATIVE 1
715#define PNG_sRGB_INTENT_SATURATION 2
716#define PNG_sRGB_INTENT_ABSOLUTE 3
717#define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */
718
719/* This is for text chunks */
720#define PNG_KEYWORD_MAX_LENGTH 79
721
722/* Maximum number of entries in PLTE/sPLT/tRNS arrays */
723#define PNG_MAX_PALETTE_LENGTH 256
724
725/* These determine if an ancillary chunk's data has been successfully read
726 * from the PNG header, or if the application has filled in the corresponding
727 * data in the info_struct to be written into the output file. The values
728 * of the PNG_INFO_<chunk> defines should NOT be changed.
729 */
730#define PNG_INFO_gAMA 0x0001U
731#define PNG_INFO_sBIT 0x0002U
732#define PNG_INFO_cHRM 0x0004U
733#define PNG_INFO_PLTE 0x0008U
734#define PNG_INFO_tRNS 0x0010U
735#define PNG_INFO_bKGD 0x0020U
736#define PNG_INFO_hIST 0x0040U
737#define PNG_INFO_pHYs 0x0080U
738#define PNG_INFO_oFFs 0x0100U
739#define PNG_INFO_tIME 0x0200U
740#define PNG_INFO_pCAL 0x0400U
741#define PNG_INFO_sRGB 0x0800U /* GR-P, 0.96a */
742#define PNG_INFO_iCCP 0x1000U /* ESR, 1.0.6 */
743#define PNG_INFO_sPLT 0x2000U /* ESR, 1.0.6 */
744#define PNG_INFO_sCAL 0x4000U /* ESR, 1.0.6 */
745#define PNG_INFO_IDAT 0x8000U /* ESR, 1.0.6 */
746#define PNG_INFO_eXIf 0x10000U /* GR-P, 1.6.31 */
747#define PNG_INFO_cICP 0x20000U /* PNGv3: 1.6.45 */
748#define PNG_INFO_cLLI 0x40000U /* PNGv3: 1.6.45 */
749#define PNG_INFO_mDCV 0x80000U /* PNGv3: 1.6.45 */
750/* APNG: these chunks are stored as unknown, these flags are never set
751 * however they are provided as a convenience for implementors of APNG and
752 * avoids any merge conflicts.
753 *
754 * Private chunks: these chunk names violate the chunk name recommendations
755 * because the chunk definitions have no signature and because the private
756 * chunks with these names have been reserved. Private definitions should
757 * avoid them.
758 */
759#define PNG_INFO_acTL 0x100000U /* PNGv3: 1.6.45: unknown */
760#define PNG_INFO_fcTL 0x200000U /* PNGv3: 1.6.45: unknown */
761#define PNG_INFO_fdAT 0x400000U /* PNGv3: 1.6.45: unknown */
762
763/* This is used for the transformation routines, as some of them
764 * change these values for the row. It also should enable using
765 * the routines for other purposes.
766 */
767typedef struct png_row_info_struct
768{
769 png_uint_32 width; /* width of row */
770 size_t rowbytes; /* number of bytes in row */
771 png_byte color_type; /* color type of row */
772 png_byte bit_depth; /* bit depth of row */
773 png_byte channels; /* number of channels (1, 2, 3, or 4) */
774 png_byte pixel_depth; /* bits per pixel (depth * channels) */
775} png_row_info;
776
777typedef png_row_info * png_row_infop;
778typedef png_row_info * * png_row_infopp;
779
780/* These are the function types for the I/O functions and for the functions
781 * that allow the user to override the default I/O functions with his or her
782 * own. The png_error_ptr type should match that of user-supplied warning
783 * and error functions, while the png_rw_ptr type should match that of the
784 * user read/write data functions. Note that the 'write' function must not
785 * modify the buffer it is passed. The 'read' function, on the other hand, is
786 * expected to return the read data in the buffer.
787 */
788typedef PNG_CALLBACK(void, *png_error_ptr,
789 (png_structp, png_const_charp));
790typedef PNG_CALLBACK(void, *png_rw_ptr,
791 (png_structp, png_bytep, size_t));
792typedef PNG_CALLBACK(void, *png_flush_ptr,
793 (png_structp));
794typedef PNG_CALLBACK(void, *png_read_status_ptr,
795 (png_structp, png_uint_32, int));
796typedef PNG_CALLBACK(void, *png_write_status_ptr,
797 (png_structp, png_uint_32, int));
798
799#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
800typedef PNG_CALLBACK(void, *png_progressive_info_ptr,
801 (png_structp, png_infop));
802typedef PNG_CALLBACK(void, *png_progressive_end_ptr,
803 (png_structp, png_infop));
804
805/* The following callback receives png_uint_32 row_number, int pass for the
806 * png_bytep data of the row. When transforming an interlaced image the
807 * row number is the row number within the sub-image of the interlace pass, so
808 * the value will increase to the height of the sub-image (not the full image)
809 * then reset to 0 for the next pass.
810 *
811 * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
812 * find the output pixel (x,y) given an interlaced sub-image pixel
813 * (row,col,pass). (See below for these macros.)
814 */
815typedef PNG_CALLBACK(void, *png_progressive_row_ptr,
816 (png_structp, png_bytep, png_uint_32, int));
817#endif
818
819#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
820 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
821typedef PNG_CALLBACK(void, *png_user_transform_ptr,
822 (png_structp, png_row_infop, png_bytep));
823#endif
824
825#ifdef PNG_USER_CHUNKS_SUPPORTED
826typedef PNG_CALLBACK(int, *png_user_chunk_ptr,
827 (png_structp, png_unknown_chunkp));
828#endif
829#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
830/* not used anywhere */
831/* typedef PNG_CALLBACK(void, *png_unknown_chunk_ptr, (png_structp)); */
832#endif
833
834#ifdef PNG_SETJMP_SUPPORTED
835/* This must match the function definition in <setjmp.h>, and the application
836 * must include this before png.h to obtain the definition of jmp_buf. The
837 * function is required to be PNG_NORETURN, but this is not checked. If the
838 * function does return the application will crash via an abort() or similar
839 * system level call.
840 *
841 * If you get a warning here while building the library you may need to make
842 * changes to ensure that pnglibconf.h records the calling convention used by
843 * your compiler. This may be very difficult - try using a different compiler
844 * to build the library!
845 */
846PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), (jmp_buf, int), typedef);
847#endif
848
849/* Transform masks for the high-level interface */
850#define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */
851#define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */
852#define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */
853#define PNG_TRANSFORM_PACKING 0x0004 /* read and write */
854#define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */
855#define PNG_TRANSFORM_EXPAND 0x0010 /* read only */
856#define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */
857#define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */
858#define PNG_TRANSFORM_BGR 0x0080 /* read and write */
859#define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */
860#define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */
861#define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */
862#define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* write only */
863/* Added to libpng-1.2.34 */
864#define PNG_TRANSFORM_STRIP_FILLER_BEFORE PNG_TRANSFORM_STRIP_FILLER
865#define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */
866/* Added to libpng-1.4.0 */
867#define PNG_TRANSFORM_GRAY_TO_RGB 0x2000 /* read only */
868/* Added to libpng-1.5.4 */
869#define PNG_TRANSFORM_EXPAND_16 0x4000 /* read only */
870#if ~0U > 0xffffU /* or else this might break on a 16-bit machine */
871#define PNG_TRANSFORM_SCALE_16 0x8000 /* read only */
872#endif
873
874/* Flags for MNG supported features */
875#define PNG_FLAG_MNG_EMPTY_PLTE 0x01
876#define PNG_FLAG_MNG_FILTER_64 0x04
877#define PNG_ALL_MNG_FEATURES 0x05
878
879/* NOTE: prior to 1.5 these functions had no 'API' style declaration,
880 * this allowed the zlib default functions to be used on Windows
881 * platforms. In 1.5 the zlib default malloc (which just calls malloc and
882 * ignores the first argument) should be completely compatible with the
883 * following.
884 */
885typedef PNG_CALLBACK(png_voidp, *png_malloc_ptr,
886 (png_structp, png_alloc_size_t));
887typedef PNG_CALLBACK(void, *png_free_ptr,
888 (png_structp, png_voidp));
889
890/* Section 4: exported functions
891 * Here are the function definitions most commonly used. This is not
892 * the place to find out how to use libpng. See libpng-manual.txt for the
893 * full explanation, see example.c for the summary. This just provides
894 * a simple one line description of the use of each function.
895 *
896 * The PNG_EXPORT() and PNG_EXPORTA() macros used below are defined in
897 * pngconf.h and in the *.dfn files in the scripts directory.
898 *
899 * PNG_EXPORT(ordinal, type, name, (args));
900 *
901 * ordinal: ordinal that is used while building
902 * *.def files. The ordinal value is only
903 * relevant when preprocessing png.h with
904 * the *.dfn files for building symbol table
905 * entries, and are removed by pngconf.h.
906 * type: return type of the function
907 * name: function name
908 * args: function arguments, with types
909 *
910 * When we wish to append attributes to a function prototype we use
911 * the PNG_EXPORTA() macro instead.
912 *
913 * PNG_EXPORTA(ordinal, type, name, (args), attributes);
914 *
915 * ordinal, type, name, and args: same as in PNG_EXPORT().
916 * attributes: function attributes
917 */
918
919/* Returns the version number of the library */
920PNG_EXPORT(1, png_uint_32, png_access_version_number,
921 (void));
922
923/* Tell lib we have already handled the first <num_bytes> magic bytes.
924 * Handling more than 8 bytes from the beginning of the file is an error.
925 */
926PNG_EXPORT(2, void, png_set_sig_bytes,
927 (png_structrp png_ptr, int num_bytes));
928
929/* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
930 * PNG file. Returns zero if the supplied bytes match the 8-byte PNG
931 * signature, and non-zero otherwise. Having num_to_check == 0 or
932 * start > 7 will always fail (i.e. return non-zero).
933 */
934PNG_EXPORT(3, int, png_sig_cmp,
935 (png_const_bytep sig, size_t start, size_t num_to_check));
936
937/* Simple signature checking function. This is the same as calling
938 * png_check_sig(sig, n) := (png_sig_cmp(sig, 0, n) == 0).
939 */
940#define png_check_sig(sig, n) (png_sig_cmp((sig), 0, (n)) == 0) /* DEPRECATED */
941
942/* Allocate and initialize png_ptr struct for reading, and any other memory. */
943PNG_EXPORTA(4, png_structp, png_create_read_struct,
944 (png_const_charp user_png_ver,
945 png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warn_fn),
946 PNG_ALLOCATED);
947
948/* Allocate and initialize png_ptr struct for writing, and any other memory */
949PNG_EXPORTA(5, png_structp, png_create_write_struct,
950 (png_const_charp user_png_ver,
951 png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warn_fn),
952 PNG_ALLOCATED);
953
954PNG_EXPORT(6, size_t, png_get_compression_buffer_size,
955 (png_const_structrp png_ptr));
956
957PNG_EXPORT(7, void, png_set_compression_buffer_size,
958 (png_structrp png_ptr, size_t size));
959
960/* Moved from pngconf.h in 1.4.0 and modified to ensure setjmp/longjmp
961 * match up.
962 */
963#ifdef PNG_SETJMP_SUPPORTED
964/* This function returns the jmp_buf built in to *png_ptr. It must be
965 * supplied with an appropriate 'longjmp' function to use on that jmp_buf
966 * unless the default error function is overridden in which case NULL is
967 * acceptable. The size of the jmp_buf is checked against the actual size
968 * allocated by the library - the call will return NULL on a mismatch
969 * indicating an ABI mismatch.
970 */
971PNG_EXPORT(8, jmp_buf*, png_set_longjmp_fn,
972 (png_structrp png_ptr, png_longjmp_ptr longjmp_fn, size_t jmp_buf_size));
973# define png_jmpbuf(png_ptr) \
974 (*png_set_longjmp_fn((png_ptr), longjmp, (sizeof (jmp_buf))))
975#else
976# define png_jmpbuf(png_ptr) \
977 (LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP)
978#endif
979/* This function should be used by libpng applications in place of
980 * longjmp(png_ptr->jmpbuf, val). If longjmp_fn() has been set, it
981 * will use it; otherwise it will call PNG_ABORT(). This function was
982 * added in libpng-1.5.0.
983 */
984PNG_EXPORTA(9, void, png_longjmp,
985 (png_const_structrp png_ptr, int val),
986 PNG_NORETURN);
987
988#ifdef PNG_READ_SUPPORTED
989/* Reset the compression stream */
990PNG_EXPORTA(10, int, png_reset_zstream,
991 (png_structrp png_ptr),
992 PNG_DEPRECATED);
993#endif
994
995/* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */
996#ifdef PNG_USER_MEM_SUPPORTED
997PNG_EXPORTA(11, png_structp, png_create_read_struct_2,
998 (png_const_charp user_png_ver,
999 png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warn_fn,
1000 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn),
1001 PNG_ALLOCATED);
1002PNG_EXPORTA(12, png_structp, png_create_write_struct_2,
1003 (png_const_charp user_png_ver,
1004 png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warn_fn,
1005 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn),
1006 PNG_ALLOCATED);
1007#endif
1008
1009/* Write the PNG file signature. */
1010PNG_EXPORT(13, void, png_write_sig,
1011 (png_structrp png_ptr));
1012
1013/* Write a PNG chunk - size, type, (optional) data, CRC. */
1014PNG_EXPORT(14, void, png_write_chunk,
1015 (png_structrp png_ptr,
1016 png_const_bytep chunk_name, png_const_bytep data, size_t length));
1017
1018/* Write the start of a PNG chunk - length and chunk name. */
1019PNG_EXPORT(15, void, png_write_chunk_start,
1020 (png_structrp png_ptr,
1021 png_const_bytep chunk_name, png_uint_32 length));
1022
1023/* Write the data of a PNG chunk started with png_write_chunk_start(). */
1024PNG_EXPORT(16, void, png_write_chunk_data,
1025 (png_structrp png_ptr,
1026 png_const_bytep data, size_t length));
1027
1028/* Finish a chunk started with png_write_chunk_start() (includes CRC). */
1029PNG_EXPORT(17, void, png_write_chunk_end,
1030 (png_structrp png_ptr));
1031
1032/* Allocate and initialize the info structure */
1033PNG_EXPORTA(18, png_infop, png_create_info_struct,
1034 (png_const_structrp png_ptr),
1035 PNG_ALLOCATED);
1036
1037/* DEPRECATED: this function allowed init structures to be created using the
1038 * default allocation method (typically malloc). Use is deprecated in 1.6.0 and
1039 * the API will be removed in the future.
1040 */
1041PNG_EXPORTA(19, void, png_info_init_3,
1042 (png_infopp info_ptr, size_t png_info_struct_size),
1043 PNG_DEPRECATED);
1044
1045/* Writes all the PNG information before the image. */
1046PNG_EXPORT(20, void, png_write_info_before_PLTE,
1047 (png_structrp png_ptr, png_const_inforp info_ptr));
1048PNG_EXPORT(21, void, png_write_info,
1049 (png_structrp png_ptr, png_const_inforp info_ptr));
1050
1051#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1052/* Read the information before the actual image data. */
1053PNG_EXPORT(22, void, png_read_info,
1054 (png_structrp png_ptr, png_inforp info_ptr));
1055#endif
1056
1057#ifdef PNG_TIME_RFC1123_SUPPORTED
1058 /* Convert to a US string format: there is no localization support in this
1059 * routine. The original implementation used a 29 character buffer in
1060 * png_struct, this will be removed in future versions.
1061 */
1062#if PNG_LIBPNG_VER < 10700
1063/* To do: remove this from libpng17 (and from libpng17/png.c and pngstruct.h) */
1064PNG_EXPORTA(23, png_const_charp, png_convert_to_rfc1123,
1065 (png_structrp png_ptr, png_const_timep ptime),
1066 PNG_DEPRECATED);
1067#endif
1068PNG_EXPORT(241, int, png_convert_to_rfc1123_buffer,
1069 (char out[29], png_const_timep ptime));
1070#endif
1071
1072#ifdef PNG_CONVERT_tIME_SUPPORTED
1073/* Convert from a struct tm to png_time */
1074PNG_EXPORT(24, void, png_convert_from_struct_tm,
1075 (png_timep ptime, const struct tm * ttime));
1076
1077/* Convert from time_t to png_time. Uses gmtime() */
1078PNG_EXPORT(25, void, png_convert_from_time_t,
1079 (png_timep ptime, time_t ttime));
1080#endif /* CONVERT_tIME */
1081
1082#ifdef PNG_READ_EXPAND_SUPPORTED
1083/* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
1084PNG_EXPORT(26, void, png_set_expand,
1085 (png_structrp png_ptr));
1086PNG_EXPORT(27, void, png_set_expand_gray_1_2_4_to_8,
1087 (png_structrp png_ptr));
1088PNG_EXPORT(28, void, png_set_palette_to_rgb,
1089 (png_structrp png_ptr));
1090PNG_EXPORT(29, void, png_set_tRNS_to_alpha,
1091 (png_structrp png_ptr));
1092#endif
1093
1094#ifdef PNG_READ_EXPAND_16_SUPPORTED
1095/* Expand to 16-bit channels, forces conversion of palette to RGB and expansion
1096 * of a tRNS chunk if present.
1097 */
1098PNG_EXPORT(221, void, png_set_expand_16,
1099 (png_structrp png_ptr));
1100#endif
1101
1102#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
1103/* Use blue, green, red order for pixels. */
1104PNG_EXPORT(30, void, png_set_bgr,
1105 (png_structrp png_ptr));
1106#endif
1107
1108#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
1109/* Expand the grayscale to 24-bit RGB if necessary. */
1110PNG_EXPORT(31, void, png_set_gray_to_rgb,
1111 (png_structrp png_ptr));
1112#endif
1113
1114#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1115/* Reduce RGB to grayscale. */
1116#define PNG_ERROR_ACTION_NONE 1
1117#define PNG_ERROR_ACTION_WARN 2
1118#define PNG_ERROR_ACTION_ERROR 3
1119#define PNG_RGB_TO_GRAY_DEFAULT (-1)/*for red/green coefficients*/
1120
1121PNG_FP_EXPORT(32, void, png_set_rgb_to_gray,
1122 (png_structrp png_ptr,
1123 int error_action, double red, double green))
1124PNG_FIXED_EXPORT(33, void, png_set_rgb_to_gray_fixed,
1125 (png_structrp png_ptr,
1126 int error_action, png_fixed_point red, png_fixed_point green))
1127
1128PNG_EXPORT(34, png_byte, png_get_rgb_to_gray_status,
1129 (png_const_structrp png_ptr));
1130#endif
1131
1132#ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED
1133PNG_EXPORT(35, void, png_build_grayscale_palette,
1134 (int bit_depth, png_colorp palette));
1135#endif
1136
1137#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
1138/* How the alpha channel is interpreted - this affects how the color channels
1139 * of a PNG file are returned to the calling application when an alpha channel,
1140 * or a tRNS chunk in a palette file, is present.
1141 *
1142 * This has no effect on the way pixels are written into a PNG output
1143 * datastream. The color samples in a PNG datastream are never premultiplied
1144 * with the alpha samples.
1145 *
1146 * The default is to return data according to the PNG specification: the alpha
1147 * channel is a linear measure of the contribution of the pixel to the
1148 * corresponding composited pixel, and the color channels are unassociated
1149 * (not premultiplied). The gamma encoded color channels must be scaled
1150 * according to the contribution and to do this it is necessary to undo
1151 * the encoding, scale the color values, perform the composition and re-encode
1152 * the values. This is the 'PNG' mode.
1153 *
1154 * The alternative is to 'associate' the alpha with the color information by
1155 * storing color channel values that have been scaled by the alpha.
1156 * image. These are the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' modes
1157 * (the latter being the two common names for associated alpha color channels).
1158 *
1159 * For the 'OPTIMIZED' mode, a pixel is treated as opaque only if the alpha
1160 * value is equal to the maximum value.
1161 *
1162 * The final choice is to gamma encode the alpha channel as well. This is
1163 * broken because, in practice, no implementation that uses this choice
1164 * correctly undoes the encoding before handling alpha composition. Use this
1165 * choice only if other serious errors in the software or hardware you use
1166 * mandate it; the typical serious error is for dark halos to appear around
1167 * opaque areas of the composited PNG image because of arithmetic overflow.
1168 *
1169 * The API function png_set_alpha_mode specifies which of these choices to use
1170 * with an enumerated 'mode' value and the gamma of the required output:
1171 */
1172#define PNG_ALPHA_PNG 0 /* according to the PNG standard */
1173#define PNG_ALPHA_STANDARD 1 /* according to Porter/Duff */
1174#define PNG_ALPHA_ASSOCIATED 1 /* as above; this is the normal practice */
1175#define PNG_ALPHA_PREMULTIPLIED 1 /* as above */
1176#define PNG_ALPHA_OPTIMIZED 2 /* 'PNG' for opaque pixels, else 'STANDARD' */
1177#define PNG_ALPHA_BROKEN 3 /* the alpha channel is gamma encoded */
1178
1179PNG_FP_EXPORT(227, void, png_set_alpha_mode,
1180 (png_structrp png_ptr, int mode, double output_gamma))
1181PNG_FIXED_EXPORT(228, void, png_set_alpha_mode_fixed,
1182 (png_structrp png_ptr, int mode, png_fixed_point output_gamma))
1183#endif
1184
1185#if defined(PNG_GAMMA_SUPPORTED) || defined(PNG_READ_ALPHA_MODE_SUPPORTED)
1186/* The output_gamma value is a screen gamma in libpng terminology: it expresses
1187 * how to decode the output values, not how they are encoded.
1188 */
1189#define PNG_DEFAULT_sRGB -1 /* sRGB gamma and color space */
1190#define PNG_GAMMA_MAC_18 -2 /* Old Mac '1.8' gamma and color space */
1191#define PNG_GAMMA_sRGB 220000 /* Television standards--matches sRGB gamma */
1192#define PNG_GAMMA_LINEAR PNG_FP_1 /* Linear */
1193#endif
1194
1195/* The following are examples of calls to png_set_alpha_mode to achieve the
1196 * required overall gamma correction and, where necessary, alpha
1197 * premultiplication.
1198 *
1199 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
1200 * This is the default libpng handling of the alpha channel - it is not
1201 * pre-multiplied into the color components. In addition the call states
1202 * that the output is for a sRGB system and causes all PNG files without gAMA
1203 * chunks to be assumed to be encoded using sRGB.
1204 *
1205 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
1206 * In this case the output is assumed to be something like an sRGB conformant
1207 * display preceded by a power-law lookup table of power 1.45. This is how
1208 * early Mac systems behaved.
1209 *
1210 * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR);
1211 * This is the classic Jim Blinn approach and will work in academic
1212 * environments where everything is done by the book. It has the shortcoming
1213 * of assuming that input PNG data with no gamma information is linear - this
1214 * is unlikely to be correct unless the PNG files where generated locally.
1215 * Most of the time the output precision will be so low as to show
1216 * significant banding in dark areas of the image.
1217 *
1218 * png_set_expand_16(pp);
1219 * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB);
1220 * This is a somewhat more realistic Jim Blinn inspired approach. PNG files
1221 * are assumed to have the sRGB encoding if not marked with a gamma value and
1222 * the output is always 16 bits per component. This permits accurate scaling
1223 * and processing of the data. If you know that your input PNG files were
1224 * generated locally you might need to replace PNG_DEFAULT_sRGB with the
1225 * correct value for your system.
1226 *
1227 * png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB);
1228 * If you just need to composite the PNG image onto an existing background
1229 * and if you control the code that does this you can use the optimization
1230 * setting. In this case you just copy completely opaque pixels to the
1231 * output. For pixels that are not completely transparent (you just skip
1232 * those) you do the composition math using png_composite or png_composite_16
1233 * below then encode the resultant 8-bit or 16-bit values to match the output
1234 * encoding.
1235 *
1236 * Other cases
1237 * If neither the PNG nor the standard linear encoding work for you because
1238 * of the software or hardware you use then you have a big problem. The PNG
1239 * case will probably result in halos around the image. The linear encoding
1240 * will probably result in a washed out, too bright, image (it's actually too
1241 * contrasty.) Try the ALPHA_OPTIMIZED mode above - this will probably
1242 * substantially reduce the halos. Alternatively try:
1243 *
1244 * png_set_alpha_mode(pp, PNG_ALPHA_BROKEN, PNG_DEFAULT_sRGB);
1245 * This option will also reduce the halos, but there will be slight dark
1246 * halos round the opaque parts of the image where the background is light.
1247 * In the OPTIMIZED mode the halos will be light halos where the background
1248 * is dark. Take your pick - the halos are unavoidable unless you can get
1249 * your hardware/software fixed! (The OPTIMIZED approach is slightly
1250 * faster.)
1251 *
1252 * When the default gamma of PNG files doesn't match the output gamma.
1253 * If you have PNG files with no gamma information png_set_alpha_mode allows
1254 * you to provide a default gamma, but it also sets the output gamma to the
1255 * matching value. If you know your PNG files have a gamma that doesn't
1256 * match the output you can take advantage of the fact that
1257 * png_set_alpha_mode always sets the output gamma but only sets the PNG
1258 * default if it is not already set:
1259 *
1260 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
1261 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
1262 * The first call sets both the default and the output gamma values, the
1263 * second call overrides the output gamma without changing the default. This
1264 * is easier than achieving the same effect with png_set_gamma. You must use
1265 * PNG_ALPHA_PNG for the first call - internal checking in png_set_alpha will
1266 * fire if more than one call to png_set_alpha_mode and png_set_background is
1267 * made in the same read operation, however multiple calls with PNG_ALPHA_PNG
1268 * are ignored.
1269 */
1270
1271#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
1272PNG_EXPORT(36, void, png_set_strip_alpha,
1273 (png_structrp png_ptr));
1274#endif
1275
1276#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
1277 defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
1278PNG_EXPORT(37, void, png_set_swap_alpha,
1279 (png_structrp png_ptr));
1280#endif
1281
1282#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
1283 defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
1284PNG_EXPORT(38, void, png_set_invert_alpha,
1285 (png_structrp png_ptr));
1286#endif
1287
1288#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
1289/* Add a filler byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */
1290PNG_EXPORT(39, void, png_set_filler,
1291 (png_structrp png_ptr, png_uint_32 filler, int flags));
1292/* The values of the PNG_FILLER_ defines should NOT be changed */
1293# define PNG_FILLER_BEFORE 0
1294# define PNG_FILLER_AFTER 1
1295/* Add an alpha byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */
1296PNG_EXPORT(40, void, png_set_add_alpha,
1297 (png_structrp png_ptr, png_uint_32 filler, int flags));
1298#endif /* READ_FILLER || WRITE_FILLER */
1299
1300#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
1301/* Swap bytes in 16-bit depth files. */
1302PNG_EXPORT(41, void, png_set_swap,
1303 (png_structrp png_ptr));
1304#endif
1305
1306#if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
1307/* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
1308PNG_EXPORT(42, void, png_set_packing,
1309 (png_structrp png_ptr));
1310#endif
1311
1312#if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
1313 defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1314/* Swap packing order of pixels in bytes. */
1315PNG_EXPORT(43, void, png_set_packswap,
1316 (png_structrp png_ptr));
1317#endif
1318
1319#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
1320/* Converts files to legal bit depths. */
1321PNG_EXPORT(44, void, png_set_shift,
1322 (png_structrp png_ptr, png_const_color_8p true_bits));
1323#endif
1324
1325#if defined(PNG_READ_INTERLACING_SUPPORTED) || \
1326 defined(PNG_WRITE_INTERLACING_SUPPORTED)
1327/* Have the code handle the interlacing. Returns the number of passes.
1328 * MUST be called before png_read_update_info or png_start_read_image,
1329 * otherwise it will not have the desired effect. Note that it is still
1330 * necessary to call png_read_row or png_read_rows png_get_image_height
1331 * times for each pass.
1332*/
1333PNG_EXPORT(45, int, png_set_interlace_handling,
1334 (png_structrp png_ptr));
1335#endif
1336
1337#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
1338/* Invert monochrome files */
1339PNG_EXPORT(46, void, png_set_invert_mono,
1340 (png_structrp png_ptr));
1341#endif
1342
1343#ifdef PNG_READ_BACKGROUND_SUPPORTED
1344/* Handle alpha and tRNS by replacing with a background color. Prior to
1345 * libpng-1.5.4 this API must not be called before the PNG file header has been
1346 * read. Doing so will result in unexpected behavior and possible warnings or
1347 * errors if the PNG file contains a bKGD chunk.
1348 */
1349PNG_FP_EXPORT(47, void, png_set_background,
1350 (png_structrp png_ptr,
1351 png_const_color_16p background_color, int background_gamma_code,
1352 int need_expand, double background_gamma))
1353PNG_FIXED_EXPORT(215, void, png_set_background_fixed,
1354 (png_structrp png_ptr,
1355 png_const_color_16p background_color, int background_gamma_code,
1356 int need_expand, png_fixed_point background_gamma))
1357#endif
1358#ifdef PNG_READ_BACKGROUND_SUPPORTED
1359# define PNG_BACKGROUND_GAMMA_UNKNOWN 0
1360# define PNG_BACKGROUND_GAMMA_SCREEN 1
1361# define PNG_BACKGROUND_GAMMA_FILE 2
1362# define PNG_BACKGROUND_GAMMA_UNIQUE 3
1363#endif
1364
1365#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
1366/* Scale a 16-bit depth file down to 8-bit, accurately. */
1367PNG_EXPORT(229, void, png_set_scale_16,
1368 (png_structrp png_ptr));
1369#endif
1370
1371#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
1372#define PNG_READ_16_TO_8_SUPPORTED /* Name prior to 1.5.4 */
1373/* Strip the second byte of information from a 16-bit depth file. */
1374PNG_EXPORT(48, void, png_set_strip_16,
1375 (png_structrp png_ptr));
1376#endif
1377
1378#ifdef PNG_READ_QUANTIZE_SUPPORTED
1379/* Turn on quantizing, and reduce the palette to the number of colors
1380 * available.
1381 */
1382PNG_EXPORT(49, void, png_set_quantize,
1383 (png_structrp png_ptr,
1384 png_colorp palette, int num_palette, int maximum_colors,
1385 png_const_uint_16p histogram, int full_quantize));
1386#endif
1387
1388#ifdef PNG_READ_GAMMA_SUPPORTED
1389/* The threshold on gamma processing is configurable but hard-wired into the
1390 * library. The following is the floating point variant.
1391 */
1392#define PNG_GAMMA_THRESHOLD (PNG_GAMMA_THRESHOLD_FIXED*.00001)
1393
1394/* Handle gamma correction. Screen_gamma=(display_exponent).
1395 * NOTE: this API simply sets the screen and file gamma values. It will
1396 * therefore override the value for gamma in a PNG file if it is called after
1397 * the file header has been read - use with care - call before reading the PNG
1398 * file for best results!
1399 *
1400 * These routines accept the same gamma values as png_set_alpha_mode (described
1401 * above). The PNG_GAMMA_ defines and PNG_DEFAULT_sRGB can be passed to either
1402 * API (floating point or fixed.) Notice, however, that the 'file_gamma' value
1403 * is the inverse of a 'screen gamma' value.
1404 */
1405PNG_FP_EXPORT(50, void, png_set_gamma,
1406 (png_structrp png_ptr,
1407 double screen_gamma, double override_file_gamma))
1408PNG_FIXED_EXPORT(208, void, png_set_gamma_fixed,
1409 (png_structrp png_ptr,
1410 png_fixed_point screen_gamma, png_fixed_point override_file_gamma))
1411#endif
1412
1413#ifdef PNG_WRITE_FLUSH_SUPPORTED
1414/* Set how many lines between output flushes - 0 for no flushing */
1415PNG_EXPORT(51, void, png_set_flush,
1416 (png_structrp png_ptr, int nrows));
1417/* Flush the current PNG output buffer */
1418PNG_EXPORT(52, void, png_write_flush,
1419 (png_structrp png_ptr));
1420#endif
1421
1422/* Optional update palette with requested transformations */
1423PNG_EXPORT(53, void, png_start_read_image,
1424 (png_structrp png_ptr));
1425
1426/* Optional call to update the users info structure */
1427PNG_EXPORT(54, void, png_read_update_info,
1428 (png_structrp png_ptr, png_inforp info_ptr));
1429
1430#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1431/* Read one or more rows of image data. */
1432PNG_EXPORT(55, void, png_read_rows,
1433 (png_structrp png_ptr, png_bytepp row,
1434 png_bytepp display_row, png_uint_32 num_rows));
1435#endif
1436
1437#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1438/* Read a row of data. */
1439PNG_EXPORT(56, void, png_read_row,
1440 (png_structrp png_ptr, png_bytep row, png_bytep display_row));
1441#endif
1442
1443#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1444/* Read the whole image into memory at once. */
1445PNG_EXPORT(57, void, png_read_image,
1446 (png_structrp png_ptr, png_bytepp image));
1447#endif
1448
1449/* Write a row of image data */
1450PNG_EXPORT(58, void, png_write_row,
1451 (png_structrp png_ptr, png_const_bytep row));
1452
1453/* Write a few rows of image data: (*row) is not written; however, the type
1454 * is declared as writeable to maintain compatibility with previous versions
1455 * of libpng and to allow the 'display_row' array from read_rows to be passed
1456 * unchanged to write_rows.
1457 */
1458PNG_EXPORT(59, void, png_write_rows,
1459 (png_structrp png_ptr, png_bytepp row, png_uint_32 num_rows));
1460
1461/* Write the image data */
1462PNG_EXPORT(60, void, png_write_image,
1463 (png_structrp png_ptr, png_bytepp image));
1464
1465/* Write the end of the PNG file. */
1466PNG_EXPORT(61, void, png_write_end,
1467 (png_structrp png_ptr, png_inforp info_ptr));
1468
1469#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1470/* Read the end of the PNG file. */
1471PNG_EXPORT(62, void, png_read_end,
1472 (png_structrp png_ptr, png_inforp info_ptr));
1473#endif
1474
1475/* Free any memory associated with the png_info_struct */
1476PNG_EXPORT(63, void, png_destroy_info_struct,
1477 (png_const_structrp png_ptr, png_infopp info_ptr_ptr));
1478
1479/* Free any memory associated with the png_struct and the png_info_structs */
1480PNG_EXPORT(64, void, png_destroy_read_struct,
1481 (png_structpp png_ptr_ptr,
1482 png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr));
1483
1484/* Free any memory associated with the png_struct and the png_info_structs */
1485PNG_EXPORT(65, void, png_destroy_write_struct,
1486 (png_structpp png_ptr_ptr, png_infopp info_ptr_ptr));
1487
1488/* Set the libpng method of handling chunk CRC errors */
1489PNG_EXPORT(66, void, png_set_crc_action,
1490 (png_structrp png_ptr, int crit_action, int ancil_action));
1491
1492/* Values for png_set_crc_action() say how to handle CRC errors in
1493 * ancillary and critical chunks, and whether to use the data contained
1494 * therein. Note that it is impossible to "discard" data in a critical
1495 * chunk. For versions prior to 0.90, the action was always error/quit,
1496 * whereas in version 0.90 and later, the action for CRC errors in ancillary
1497 * chunks is warn/discard. These values should NOT be changed.
1498 *
1499 * value action:critical action:ancillary
1500 */
1501#define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */
1502#define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */
1503#define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */
1504#define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */
1505#define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */
1506#define PNG_CRC_NO_CHANGE 5 /* use current value use current value */
1507
1508#ifdef PNG_WRITE_SUPPORTED
1509/* These functions give the user control over the scan-line filtering in
1510 * libpng and the compression methods used by zlib. These functions are
1511 * mainly useful for testing, as the defaults should work with most users.
1512 * Those users who are tight on memory or want faster performance at the
1513 * expense of compression can modify them. See the compression library
1514 * header file (zlib.h) for an explanation of the compression functions.
1515 */
1516
1517/* Set the filtering method(s) used by libpng. Currently, the only valid
1518 * value for "method" is 0.
1519 */
1520PNG_EXPORT(67, void, png_set_filter,
1521 (png_structrp png_ptr, int method, int filters));
1522#endif /* WRITE */
1523
1524/* Flags for png_set_filter() to say which filters to use. The flags
1525 * are chosen so that they don't conflict with real filter types
1526 * below, in case they are supplied instead of the #defined constants.
1527 * These values should NOT be changed.
1528 */
1529#define PNG_NO_FILTERS 0x00
1530#define PNG_FILTER_NONE 0x08
1531#define PNG_FILTER_SUB 0x10
1532#define PNG_FILTER_UP 0x20
1533#define PNG_FILTER_AVG 0x40
1534#define PNG_FILTER_PAETH 0x80
1535#define PNG_FAST_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP)
1536#define PNG_ALL_FILTERS (PNG_FAST_FILTERS | PNG_FILTER_AVG | PNG_FILTER_PAETH)
1537
1538/* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
1539 * These defines should NOT be changed.
1540 */
1541#define PNG_FILTER_VALUE_NONE 0
1542#define PNG_FILTER_VALUE_SUB 1
1543#define PNG_FILTER_VALUE_UP 2
1544#define PNG_FILTER_VALUE_AVG 3
1545#define PNG_FILTER_VALUE_PAETH 4
1546#define PNG_FILTER_VALUE_LAST 5
1547
1548#ifdef PNG_WRITE_SUPPORTED
1549#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* DEPRECATED */
1550PNG_FP_EXPORT(68, void, png_set_filter_heuristics,
1551 (png_structrp png_ptr,
1552 int heuristic_method, int num_weights,
1553 png_const_doublep filter_weights,
1554 png_const_doublep filter_costs))
1555PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed,
1556 (png_structrp png_ptr,
1557 int heuristic_method, int num_weights,
1558 png_const_fixed_point_p filter_weights,
1559 png_const_fixed_point_p filter_costs))
1560#endif /* WRITE_WEIGHTED_FILTER */
1561
1562/* The following are no longer used and will be removed from libpng-1.7: */
1563#define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */
1564#define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */
1565#define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */
1566#define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */
1567
1568/* Set the library compression level. Currently, valid values range from
1569 * 0 - 9, corresponding directly to the zlib compression levels 0 - 9
1570 * (0 - no compression, 9 - "maximal" compression). Note that tests have
1571 * shown that zlib compression levels 3-6 usually perform as well as level 9
1572 * for PNG images, and do considerably fewer calculations. In the future,
1573 * these values may not correspond directly to the zlib compression levels.
1574 */
1575#ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED
1576PNG_EXPORT(69, void, png_set_compression_level,
1577 (png_structrp png_ptr, int level));
1578
1579PNG_EXPORT(70, void, png_set_compression_mem_level,
1580 (png_structrp png_ptr, int mem_level));
1581
1582PNG_EXPORT(71, void, png_set_compression_strategy,
1583 (png_structrp png_ptr, int strategy));
1584
1585/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
1586 * smaller value of window_bits if it can do so safely.
1587 */
1588PNG_EXPORT(72, void, png_set_compression_window_bits,
1589 (png_structrp png_ptr, int window_bits));
1590
1591PNG_EXPORT(73, void, png_set_compression_method,
1592 (png_structrp png_ptr, int method));
1593#endif /* WRITE_CUSTOMIZE_COMPRESSION */
1594
1595#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
1596/* Also set zlib parameters for compressing non-IDAT chunks */
1597PNG_EXPORT(222, void, png_set_text_compression_level,
1598 (png_structrp png_ptr, int level));
1599
1600PNG_EXPORT(223, void, png_set_text_compression_mem_level,
1601 (png_structrp png_ptr, int mem_level));
1602
1603PNG_EXPORT(224, void, png_set_text_compression_strategy,
1604 (png_structrp png_ptr, int strategy));
1605
1606/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
1607 * smaller value of window_bits if it can do so safely.
1608 */
1609PNG_EXPORT(225, void, png_set_text_compression_window_bits,
1610 (png_structrp png_ptr, int window_bits));
1611
1612PNG_EXPORT(226, void, png_set_text_compression_method,
1613 (png_structrp png_ptr, int method));
1614#endif /* WRITE_CUSTOMIZE_ZTXT_COMPRESSION */
1615#endif /* WRITE */
1616
1617/* These next functions are called for input/output, memory, and error
1618 * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c,
1619 * and call standard C I/O routines such as fread(), fwrite(), and
1620 * fprintf(). These functions can be made to use other I/O routines
1621 * at run time for those applications that need to handle I/O in a
1622 * different manner by calling png_set_???_fn(). See libpng-manual.txt for
1623 * more information.
1624 */
1625
1626#ifdef PNG_STDIO_SUPPORTED
1627/* Initialize the input/output for the PNG file to the default functions. */
1628PNG_EXPORT(74, void, png_init_io,
1629 (png_structrp png_ptr, FILE *fp));
1630#endif
1631
1632/* Replace the (error and abort), and warning functions with user
1633 * supplied functions. If no messages are to be printed you must still
1634 * write and use replacement functions. The replacement error_fn should
1635 * still do a longjmp to the last setjmp location if you are using this
1636 * method of error handling. If error_fn or warning_fn is NULL, the
1637 * default function will be used.
1638 */
1639
1640PNG_EXPORT(75, void, png_set_error_fn,
1641 (png_structrp png_ptr,
1642 png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn));
1643
1644/* Return the user pointer associated with the error functions */
1645PNG_EXPORT(76, png_voidp, png_get_error_ptr,
1646 (png_const_structrp png_ptr));
1647
1648/* Replace the default data output functions with a user supplied one(s).
1649 * If buffered output is not used, then output_flush_fn can be set to NULL.
1650 * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time
1651 * output_flush_fn will be ignored (and thus can be NULL).
1652 * It is probably a mistake to use NULL for output_flush_fn if
1653 * write_data_fn is not also NULL unless you have built libpng with
1654 * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's
1655 * default flush function, which uses the standard *FILE structure, will
1656 * be used.
1657 */
1658PNG_EXPORT(77, void, png_set_write_fn,
1659 (png_structrp png_ptr,
1660 png_voidp io_ptr,
1661 png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn));
1662
1663/* Replace the default data input function with a user supplied one. */
1664PNG_EXPORT(78, void, png_set_read_fn,
1665 (png_structrp png_ptr,
1666 png_voidp io_ptr, png_rw_ptr read_data_fn));
1667
1668/* Return the user pointer associated with the I/O functions */
1669PNG_EXPORT(79, png_voidp, png_get_io_ptr,
1670 (png_const_structrp png_ptr));
1671
1672PNG_EXPORT(80, void, png_set_read_status_fn,
1673 (png_structrp png_ptr, png_read_status_ptr read_row_fn));
1674
1675PNG_EXPORT(81, void, png_set_write_status_fn,
1676 (png_structrp png_ptr, png_write_status_ptr write_row_fn));
1677
1678#ifdef PNG_USER_MEM_SUPPORTED
1679/* Replace the default memory allocation functions with user supplied one(s). */
1680PNG_EXPORT(82, void, png_set_mem_fn,
1681 (png_structrp png_ptr,
1682 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn));
1683/* Return the user pointer associated with the memory functions */
1684PNG_EXPORT(83, png_voidp, png_get_mem_ptr,
1685 (png_const_structrp png_ptr));
1686#endif
1687
1688#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
1689PNG_EXPORT(84, void, png_set_read_user_transform_fn,
1690 (png_structrp png_ptr, png_user_transform_ptr read_user_transform_fn));
1691#endif
1692
1693#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
1694PNG_EXPORT(85, void, png_set_write_user_transform_fn,
1695 (png_structrp png_ptr, png_user_transform_ptr write_user_transform_fn));
1696#endif
1697
1698#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
1699PNG_EXPORT(86, void, png_set_user_transform_info,
1700 (png_structrp png_ptr,
1701 png_voidp user_transform_ptr,
1702 int user_transform_depth, int user_transform_channels));
1703/* Return the user pointer associated with the user transform functions */
1704PNG_EXPORT(87, png_voidp, png_get_user_transform_ptr,
1705 (png_const_structrp png_ptr));
1706#endif
1707
1708#ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED
1709/* Return information about the row currently being processed. Note that these
1710 * APIs do not fail but will return unexpected results if called outside a user
1711 * transform callback. Also note that when transforming an interlaced image the
1712 * row number is the row number within the sub-image of the interlace pass, so
1713 * the value will increase to the height of the sub-image (not the full image)
1714 * then reset to 0 for the next pass.
1715 *
1716 * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
1717 * find the output pixel (x,y) given an interlaced sub-image pixel
1718 * (row,col,pass). (See below for these macros.)
1719 */
1720PNG_EXPORT(217, png_uint_32, png_get_current_row_number,
1721 (png_const_structrp));
1722PNG_EXPORT(218, png_byte, png_get_current_pass_number,
1723 (png_const_structrp));
1724#endif
1725
1726#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
1727/* This callback is called only for *unknown* chunks. If
1728 * PNG_HANDLE_AS_UNKNOWN_SUPPORTED is set then it is possible to set known
1729 * chunks to be treated as unknown, however in this case the callback must do
1730 * any processing required by the chunk (e.g. by calling the appropriate
1731 * png_set_ APIs.)
1732 *
1733 * There is no write support - on write, by default, all the chunks in the
1734 * 'unknown' list are written in the specified position.
1735 *
1736 * The integer return from the callback function is interpreted thus:
1737 *
1738 * negative: An error occurred; png_chunk_error will be called.
1739 * zero: The chunk was not handled, the chunk will be saved. A critical
1740 * chunk will cause an error at this point unless it is to be saved.
1741 * positive: The chunk was handled, libpng will ignore/discard it.
1742 *
1743 * See "INTERACTION WITH USER CHUNK CALLBACKS" below for important notes about
1744 * how this behavior will change in libpng 1.7
1745 */
1746PNG_EXPORT(88, void, png_set_read_user_chunk_fn,
1747 (png_structrp png_ptr,
1748 png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));
1749#endif
1750
1751#ifdef PNG_USER_CHUNKS_SUPPORTED
1752PNG_EXPORT(89, png_voidp, png_get_user_chunk_ptr,
1753 (png_const_structrp png_ptr));
1754#endif
1755
1756#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1757/* Sets the function callbacks for the push reader, and a pointer to a
1758 * user-defined structure available to the callback functions.
1759 */
1760PNG_EXPORT(90, void, png_set_progressive_read_fn,
1761 (png_structrp png_ptr,
1762 png_voidp progressive_ptr, png_progressive_info_ptr info_fn,
1763 png_progressive_row_ptr row_fn, png_progressive_end_ptr end_fn));
1764
1765/* Returns the user pointer associated with the push read functions */
1766PNG_EXPORT(91, png_voidp, png_get_progressive_ptr,
1767 (png_const_structrp png_ptr));
1768
1769/* Function to be called when data becomes available */
1770PNG_EXPORT(92, void, png_process_data,
1771 (png_structrp png_ptr,
1772 png_inforp info_ptr, png_bytep buffer, size_t buffer_size));
1773
1774/* A function which may be called *only* within png_process_data to stop the
1775 * processing of any more data. The function returns the number of bytes
1776 * remaining, excluding any that libpng has cached internally. A subsequent
1777 * call to png_process_data must supply these bytes again. If the argument
1778 * 'save' is set to true the routine will first save all the pending data and
1779 * will always return 0.
1780 */
1781PNG_EXPORT(219, size_t, png_process_data_pause,
1782 (png_structrp, int save));
1783
1784/* A function which may be called *only* outside (after) a call to
1785 * png_process_data. It returns the number of bytes of data to skip in the
1786 * input. Normally it will return 0, but if it returns a non-zero value the
1787 * application must skip than number of bytes of input data and pass the
1788 * following data to the next call to png_process_data.
1789 */
1790PNG_EXPORT(220, png_uint_32, png_process_data_skip,
1791 (png_structrp));
1792
1793/* Function that combines rows. 'new_row' is a flag that should come from
1794 * the callback and be non-NULL if anything needs to be done; the library
1795 * stores its own version of the new data internally and ignores the passed
1796 * in value.
1797 */
1798PNG_EXPORT(93, void, png_progressive_combine_row,
1799 (png_const_structrp png_ptr,
1800 png_bytep old_row, png_const_bytep new_row));
1801#endif /* PROGRESSIVE_READ */
1802
1803PNG_EXPORTA(94, png_voidp, png_malloc,
1804 (png_const_structrp png_ptr, png_alloc_size_t size),
1805 PNG_ALLOCATED);
1806/* Added at libpng version 1.4.0 */
1807PNG_EXPORTA(95, png_voidp, png_calloc,
1808 (png_const_structrp png_ptr, png_alloc_size_t size),
1809 PNG_ALLOCATED);
1810
1811/* Added at libpng version 1.2.4 */
1812PNG_EXPORTA(96, png_voidp, png_malloc_warn,
1813 (png_const_structrp png_ptr, png_alloc_size_t size),
1814 PNG_ALLOCATED);
1815
1816/* Frees a pointer allocated by png_malloc() */
1817PNG_EXPORT(97, void, png_free,
1818 (png_const_structrp png_ptr, png_voidp ptr));
1819
1820/* Free data that was allocated internally */
1821PNG_EXPORT(98, void, png_free_data,
1822 (png_const_structrp png_ptr, png_inforp info_ptr,
1823 png_uint_32 free_me, int num));
1824
1825/* Reassign the responsibility for freeing existing data, whether allocated
1826 * by libpng or by the application; this works on the png_info structure passed
1827 * in, without changing the state for other png_info structures.
1828 */
1829PNG_EXPORT(99, void, png_data_freer,
1830 (png_const_structrp png_ptr, png_inforp info_ptr,
1831 int freer, png_uint_32 mask));
1832
1833/* Assignments for png_data_freer */
1834#define PNG_DESTROY_WILL_FREE_DATA 1
1835#define PNG_SET_WILL_FREE_DATA 1
1836#define PNG_USER_WILL_FREE_DATA 2
1837/* Flags for png_ptr->free_me and info_ptr->free_me */
1838#define PNG_FREE_HIST 0x0008U
1839#define PNG_FREE_ICCP 0x0010U
1840#define PNG_FREE_SPLT 0x0020U
1841#define PNG_FREE_ROWS 0x0040U
1842#define PNG_FREE_PCAL 0x0080U
1843#define PNG_FREE_SCAL 0x0100U
1844#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
1845# define PNG_FREE_UNKN 0x0200U
1846#endif
1847/* PNG_FREE_LIST 0x0400U removed in 1.6.0 because it is ignored */
1848#define PNG_FREE_PLTE 0x1000U
1849#define PNG_FREE_TRNS 0x2000U
1850#define PNG_FREE_TEXT 0x4000U
1851#define PNG_FREE_EXIF 0x8000U /* Added at libpng-1.6.31 */
1852#define PNG_FREE_ALL 0xffffU
1853#define PNG_FREE_MUL 0x4220U /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */
1854
1855#ifdef PNG_USER_MEM_SUPPORTED
1856PNG_EXPORTA(100, png_voidp, png_malloc_default,
1857 (png_const_structrp png_ptr, png_alloc_size_t size),
1858 PNG_ALLOCATED PNG_DEPRECATED);
1859PNG_EXPORTA(101, void, png_free_default,
1860 (png_const_structrp png_ptr, png_voidp ptr),
1861 PNG_DEPRECATED);
1862#endif
1863
1864#ifdef PNG_ERROR_TEXT_SUPPORTED
1865/* Fatal error in PNG image of libpng - can't continue */
1866PNG_EXPORTA(102, void, png_error,
1867 (png_const_structrp png_ptr, png_const_charp error_message),
1868 PNG_NORETURN);
1869
1870/* The same, but the chunk name is prepended to the error string. */
1871PNG_EXPORTA(103, void, png_chunk_error,
1872 (png_const_structrp png_ptr, png_const_charp error_message),
1873 PNG_NORETURN);
1874
1875#else
1876/* Fatal error in PNG image of libpng - can't continue */
1877PNG_EXPORTA(104, void, png_err,
1878 (png_const_structrp png_ptr),
1879 PNG_NORETURN);
1880# define png_error(s1,s2) png_err(s1)
1881# define png_chunk_error(s1,s2) png_err(s1)
1882#endif
1883
1884#ifdef PNG_WARNINGS_SUPPORTED
1885/* Non-fatal error in libpng. Can continue, but may have a problem. */
1886PNG_EXPORT(105, void, png_warning,
1887 (png_const_structrp png_ptr, png_const_charp warning_message));
1888
1889/* Non-fatal error in libpng, chunk name is prepended to message. */
1890PNG_EXPORT(106, void, png_chunk_warning,
1891 (png_const_structrp png_ptr, png_const_charp warning_message));
1892#else
1893# define png_warning(s1,s2) ((void)(s1))
1894# define png_chunk_warning(s1,s2) ((void)(s1))
1895#endif
1896
1897#ifdef PNG_BENIGN_ERRORS_SUPPORTED
1898/* Benign error in libpng. Can continue, but may have a problem.
1899 * User can choose whether to handle as a fatal error or as a warning. */
1900PNG_EXPORT(107, void, png_benign_error,
1901 (png_const_structrp png_ptr, png_const_charp warning_message));
1902
1903#ifdef PNG_READ_SUPPORTED
1904/* Same, chunk name is prepended to message (only during read) */
1905PNG_EXPORT(108, void, png_chunk_benign_error,
1906 (png_const_structrp png_ptr, png_const_charp warning_message));
1907#endif
1908
1909PNG_EXPORT(109, void, png_set_benign_errors,
1910 (png_structrp png_ptr, int allowed));
1911#else
1912# ifdef PNG_ALLOW_BENIGN_ERRORS
1913# define png_benign_error png_warning
1914# define png_chunk_benign_error png_chunk_warning
1915# else
1916# define png_benign_error png_error
1917# define png_chunk_benign_error png_chunk_error
1918# endif
1919#endif
1920
1921/* The png_set_<chunk> functions are for storing values in the png_info_struct.
1922 * Similarly, the png_get_<chunk> calls are used to read values from the
1923 * png_info_struct, either storing the parameters in the passed variables, or
1924 * setting pointers into the png_info_struct where the data is stored. The
1925 * png_get_<chunk> functions return a non-zero value if the data was available
1926 * in info_ptr, or return zero and do not change any of the parameters if the
1927 * data was not available.
1928 *
1929 * These functions should be used instead of directly accessing png_info
1930 * to avoid problems with future changes in the size and internal layout of
1931 * png_info_struct.
1932 */
1933/* Returns "flag" if chunk data is valid in info_ptr. */
1934PNG_EXPORT(110, png_uint_32, png_get_valid,
1935 (png_const_structrp png_ptr, png_const_inforp info_ptr, png_uint_32 flag));
1936
1937/* Returns number of bytes needed to hold a transformed row. */
1938PNG_EXPORT(111, size_t, png_get_rowbytes,
1939 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1940
1941#ifdef PNG_INFO_IMAGE_SUPPORTED
1942/* Returns row_pointers, which is an array of pointers to scanlines that was
1943 * returned from png_read_png().
1944 */
1945PNG_EXPORT(112, png_bytepp, png_get_rows,
1946 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1947
1948/* Set row_pointers, which is an array of pointers to scanlines for use
1949 * by png_write_png().
1950 */
1951PNG_EXPORT(113, void, png_set_rows,
1952 (png_const_structrp png_ptr, png_inforp info_ptr, png_bytepp row_pointers));
1953#endif
1954
1955/* Returns number of color channels in image. */
1956PNG_EXPORT(114, png_byte, png_get_channels,
1957 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1958
1959#ifdef PNG_EASY_ACCESS_SUPPORTED
1960/* Returns image width in pixels. */
1961PNG_EXPORT(115, png_uint_32, png_get_image_width,
1962 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1963
1964/* Returns image height in pixels. */
1965PNG_EXPORT(116, png_uint_32, png_get_image_height,
1966 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1967
1968/* Returns image bit_depth. */
1969PNG_EXPORT(117, png_byte, png_get_bit_depth,
1970 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1971
1972/* Returns image color_type. */
1973PNG_EXPORT(118, png_byte, png_get_color_type,
1974 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1975
1976/* Returns image filter_type. */
1977PNG_EXPORT(119, png_byte, png_get_filter_type,
1978 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1979
1980/* Returns image interlace_type. */
1981PNG_EXPORT(120, png_byte, png_get_interlace_type,
1982 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1983
1984/* Returns image compression_type. */
1985PNG_EXPORT(121, png_byte, png_get_compression_type,
1986 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1987
1988/* Returns image resolution in pixels per meter, from pHYs chunk data. */
1989PNG_EXPORT(122, png_uint_32, png_get_pixels_per_meter,
1990 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1991PNG_EXPORT(123, png_uint_32, png_get_x_pixels_per_meter,
1992 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1993PNG_EXPORT(124, png_uint_32, png_get_y_pixels_per_meter,
1994 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1995
1996/* Returns pixel aspect ratio, computed from pHYs chunk data. */
1997PNG_FP_EXPORT(125, float, png_get_pixel_aspect_ratio,
1998 (png_const_structrp png_ptr, png_const_inforp info_ptr))
1999PNG_FIXED_EXPORT(210, png_fixed_point, png_get_pixel_aspect_ratio_fixed,
2000 (png_const_structrp png_ptr, png_const_inforp info_ptr))
2001
2002/* Returns image x, y offset in pixels or microns, from oFFs chunk data. */
2003PNG_EXPORT(126, png_int_32, png_get_x_offset_pixels,
2004 (png_const_structrp png_ptr, png_const_inforp info_ptr));
2005PNG_EXPORT(127, png_int_32, png_get_y_offset_pixels,
2006 (png_const_structrp png_ptr, png_const_inforp info_ptr));
2007PNG_EXPORT(128, png_int_32, png_get_x_offset_microns,
2008 (png_const_structrp png_ptr, png_const_inforp info_ptr));
2009PNG_EXPORT(129, png_int_32, png_get_y_offset_microns,
2010 (png_const_structrp png_ptr, png_const_inforp info_ptr));
2011
2012#endif /* EASY_ACCESS */
2013
2014#ifdef PNG_READ_SUPPORTED
2015/* Returns pointer to signature string read from PNG header */
2016PNG_EXPORT(130, png_const_bytep, png_get_signature,
2017 (png_const_structrp png_ptr, png_const_inforp info_ptr));
2018#endif
2019
2020#ifdef PNG_bKGD_SUPPORTED
2021PNG_EXPORT(131, png_uint_32, png_get_bKGD,
2022 (png_const_structrp png_ptr, png_inforp info_ptr,
2023 png_color_16p *background));
2024#endif
2025
2026#ifdef PNG_bKGD_SUPPORTED
2027PNG_EXPORT(132, void, png_set_bKGD,
2028 (png_const_structrp png_ptr, png_inforp info_ptr,
2029 png_const_color_16p background));
2030#endif
2031
2032#ifdef PNG_cHRM_SUPPORTED
2033PNG_FP_EXPORT(133, png_uint_32, png_get_cHRM,
2034 (png_const_structrp png_ptr, png_const_inforp info_ptr,
2035 double *white_x, double *white_y,
2036 double *red_x, double *red_y,
2037 double *green_x, double *green_y,
2038 double *blue_x, double *blue_y))
2039PNG_FP_EXPORT(230, png_uint_32, png_get_cHRM_XYZ,
2040 (png_const_structrp png_ptr, png_const_inforp info_ptr,
2041 double *red_X, double *red_Y, double *red_Z,
2042 double *green_X, double *green_Y, double *green_Z,
2043 double *blue_X, double *blue_Y, double *blue_Z))
2044PNG_FIXED_EXPORT(134, png_uint_32, png_get_cHRM_fixed,
2045 (png_const_structrp png_ptr, png_const_inforp info_ptr,
2046 png_fixed_point *int_white_x, png_fixed_point *int_white_y,
2047 png_fixed_point *int_red_x, png_fixed_point *int_red_y,
2048 png_fixed_point *int_green_x, png_fixed_point *int_green_y,
2049 png_fixed_point *int_blue_x, png_fixed_point *int_blue_y))
2050PNG_FIXED_EXPORT(231, png_uint_32, png_get_cHRM_XYZ_fixed,
2051 (png_const_structrp png_ptr, png_const_inforp info_ptr,
2052 png_fixed_point *int_red_X, png_fixed_point *int_red_Y,
2053 png_fixed_point *int_red_Z,
2054 png_fixed_point *int_green_X, png_fixed_point *int_green_Y,
2055 png_fixed_point *int_green_Z,
2056 png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y,
2057 png_fixed_point *int_blue_Z))
2058#endif
2059
2060#ifdef PNG_cHRM_SUPPORTED
2061PNG_FP_EXPORT(135, void, png_set_cHRM,
2062 (png_const_structrp png_ptr, png_inforp info_ptr,
2063 double white_x, double white_y,
2064 double red_x, double red_y,
2065 double green_x, double green_y,
2066 double blue_x, double blue_y))
2067PNG_FP_EXPORT(232, void, png_set_cHRM_XYZ,
2068 (png_const_structrp png_ptr, png_inforp info_ptr,
2069 double red_X, double red_Y, double red_Z,
2070 double green_X, double green_Y, double green_Z,
2071 double blue_X, double blue_Y, double blue_Z))
2072PNG_FIXED_EXPORT(136, void, png_set_cHRM_fixed,
2073 (png_const_structrp png_ptr, png_inforp info_ptr,
2074 png_fixed_point int_white_x, png_fixed_point int_white_y,
2075 png_fixed_point int_red_x, png_fixed_point int_red_y,
2076 png_fixed_point int_green_x, png_fixed_point int_green_y,
2077 png_fixed_point int_blue_x, png_fixed_point int_blue_y))
2078PNG_FIXED_EXPORT(233, void, png_set_cHRM_XYZ_fixed,
2079 (png_const_structrp png_ptr, png_inforp info_ptr,
2080 png_fixed_point int_red_X, png_fixed_point int_red_Y,
2081 png_fixed_point int_red_Z,
2082 png_fixed_point int_green_X, png_fixed_point int_green_Y,
2083 png_fixed_point int_green_Z,
2084 png_fixed_point int_blue_X, png_fixed_point int_blue_Y,
2085 png_fixed_point int_blue_Z))
2086#endif
2087
2088#ifdef PNG_cICP_SUPPORTED
2089PNG_EXPORT(250, png_uint_32, png_get_cICP,
2090 (png_const_structrp png_ptr, png_const_inforp info_ptr,
2091 png_bytep colour_primaries, png_bytep transfer_function,
2092 png_bytep matrix_coefficients, png_bytep video_full_range_flag));
2093#endif
2094
2095#ifdef PNG_cICP_SUPPORTED
2096PNG_EXPORT(251, void, png_set_cICP,
2097 (png_const_structrp png_ptr, png_inforp info_ptr,
2098 png_byte colour_primaries, png_byte transfer_function,
2099 png_byte matrix_coefficients, png_byte video_full_range_flag));
2100#endif
2101
2102#ifdef PNG_cLLI_SUPPORTED
2103PNG_FP_EXPORT(252, png_uint_32, png_get_cLLI,
2104 (png_const_structrp png_ptr, png_const_inforp info_ptr,
2105 double *maximum_content_light_level,
2106 double *maximum_frame_average_light_level))
2107PNG_FIXED_EXPORT(253, png_uint_32, png_get_cLLI_fixed,
2108 (png_const_structrp png_ptr, png_const_inforp info_ptr,
2109 /* The values below are in cd/m2 (nits) and are scaled by 10,000; not
2110 * 100,000 as in the case of png_fixed_point.
2111 */
2112 png_uint_32p maximum_content_light_level_scaled_by_10000,
2113 png_uint_32p maximum_frame_average_light_level_scaled_by_10000))
2114#endif
2115
2116#ifdef PNG_cLLI_SUPPORTED
2117PNG_FP_EXPORT(254, void, png_set_cLLI,
2118 (png_const_structrp png_ptr, png_inforp info_ptr,
2119 double maximum_content_light_level,
2120 double maximum_frame_average_light_level))
2121PNG_FIXED_EXPORT(255, void, png_set_cLLI_fixed,
2122 (png_const_structrp png_ptr, png_inforp info_ptr,
2123 /* The values below are in cd/m2 (nits) and are scaled by 10,000; not
2124 * 100,000 as in the case of png_fixed_point.
2125 */
2126 png_uint_32 maximum_content_light_level_scaled_by_10000,
2127 png_uint_32 maximum_frame_average_light_level_scaled_by_10000))
2128#endif
2129
2130#ifdef PNG_eXIf_SUPPORTED
2131PNG_EXPORT(246, png_uint_32, png_get_eXIf,
2132 (png_const_structrp png_ptr, png_inforp info_ptr, png_bytep *exif));
2133PNG_EXPORT(247, void, png_set_eXIf,
2134 (png_const_structrp png_ptr, png_inforp info_ptr, png_bytep exif));
2135
2136PNG_EXPORT(248, png_uint_32, png_get_eXIf_1,
2137 (png_const_structrp png_ptr, png_const_inforp info_ptr,
2138 png_uint_32 *num_exif, png_bytep *exif));
2139PNG_EXPORT(249, void, png_set_eXIf_1,
2140 (png_const_structrp png_ptr, png_inforp info_ptr,
2141 png_uint_32 num_exif, png_bytep exif));
2142#endif
2143
2144#ifdef PNG_gAMA_SUPPORTED
2145PNG_FP_EXPORT(137, png_uint_32, png_get_gAMA,
2146 (png_const_structrp png_ptr, png_const_inforp info_ptr,
2147 double *file_gamma))
2148PNG_FIXED_EXPORT(138, png_uint_32, png_get_gAMA_fixed,
2149 (png_const_structrp png_ptr, png_const_inforp info_ptr,
2150 png_fixed_point *int_file_gamma))
2151#endif
2152
2153#ifdef PNG_gAMA_SUPPORTED
2154PNG_FP_EXPORT(139, void, png_set_gAMA,
2155 (png_const_structrp png_ptr, png_inforp info_ptr,
2156 double file_gamma))
2157PNG_FIXED_EXPORT(140, void, png_set_gAMA_fixed,
2158 (png_const_structrp png_ptr, png_inforp info_ptr,
2159 png_fixed_point int_file_gamma))
2160#endif
2161
2162#ifdef PNG_hIST_SUPPORTED
2163PNG_EXPORT(141, png_uint_32, png_get_hIST,
2164 (png_const_structrp png_ptr, png_inforp info_ptr, png_uint_16p *hist));
2165PNG_EXPORT(142, void, png_set_hIST,
2166 (png_const_structrp png_ptr, png_inforp info_ptr, png_const_uint_16p hist));
2167#endif
2168
2169PNG_EXPORT(143, png_uint_32, png_get_IHDR,
2170 (png_const_structrp png_ptr, png_const_inforp info_ptr,
2171 png_uint_32 *width, png_uint_32 *height,
2172 int *bit_depth, int *color_type,
2173 int *interlace_method, int *compression_method, int *filter_method));
2174
2175PNG_EXPORT(144, void, png_set_IHDR,
2176 (png_const_structrp png_ptr, png_inforp info_ptr,
2177 png_uint_32 width, png_uint_32 height,
2178 int bit_depth, int color_type,
2179 int interlace_method, int compression_method, int filter_method));
2180
2181#ifdef PNG_mDCV_SUPPORTED
2182PNG_FP_EXPORT(256, png_uint_32, png_get_mDCV,
2183 (png_const_structrp png_ptr, png_const_inforp info_ptr,
2184 /* The chromaticities of the mastering display. As cHRM, but independent of
2185 * the encoding endpoints in cHRM, or cICP, or iCCP. These values will
2186 * always be in the range 0 to 1.3107.
2187 */
2188 double *white_x, double *white_y,
2189 double *red_x, double *red_y,
2190 double *green_x, double *green_y,
2191 double *blue_x, double *blue_y,
2192 /* Mastering display luminance in cd/m2 (nits). */
2193 double *mastering_display_maximum_luminance,
2194 double *mastering_display_minimum_luminance))
2195
2196PNG_FIXED_EXPORT(257, png_uint_32, png_get_mDCV_fixed,
2197 (png_const_structrp png_ptr, png_const_inforp info_ptr,
2198 png_fixed_point *int_white_x, png_fixed_point *int_white_y,
2199 png_fixed_point *int_red_x, png_fixed_point *int_red_y,
2200 png_fixed_point *int_green_x, png_fixed_point *int_green_y,
2201 png_fixed_point *int_blue_x, png_fixed_point *int_blue_y,
2202 /* Mastering display luminance in cd/m2 (nits) multiplied (scaled) by
2203 * 10,000.
2204 */
2205 png_uint_32p mastering_display_maximum_luminance_scaled_by_10000,
2206 png_uint_32p mastering_display_minimum_luminance_scaled_by_10000))
2207#endif
2208
2209#ifdef PNG_mDCV_SUPPORTED
2210PNG_FP_EXPORT(258, void, png_set_mDCV,
2211 (png_const_structrp png_ptr, png_inforp info_ptr,
2212 /* The chromaticities of the mastering display. As cHRM, but independent of
2213 * the encoding endpoints in cHRM, or cICP, or iCCP.
2214 */
2215 double white_x, double white_y,
2216 double red_x, double red_y,
2217 double green_x, double green_y,
2218 double blue_x, double blue_y,
2219 /* Mastering display luminance in cd/m2 (nits). */
2220 double mastering_display_maximum_luminance,
2221 double mastering_display_minimum_luminance))
2222
2223PNG_FIXED_EXPORT(259, void, png_set_mDCV_fixed,
2224 (png_const_structrp png_ptr, png_inforp info_ptr,
2225 /* The admissible range of these values is not the full range of a PNG
2226 * fixed point value. Negative values cannot be encoded and the maximum
2227 * value is about 1.3 */
2228 png_fixed_point int_white_x, png_fixed_point int_white_y,
2229 png_fixed_point int_red_x, png_fixed_point int_red_y,
2230 png_fixed_point int_green_x, png_fixed_point int_green_y,
2231 png_fixed_point int_blue_x, png_fixed_point int_blue_y,
2232 /* These are PNG unsigned 4 byte values: 31-bit unsigned values. The MSB
2233 * must be zero.
2234 */
2235 png_uint_32 mastering_display_maximum_luminance_scaled_by_10000,
2236 png_uint_32 mastering_display_minimum_luminance_scaled_by_10000))
2237#endif
2238
2239#ifdef PNG_oFFs_SUPPORTED
2240PNG_EXPORT(145, png_uint_32, png_get_oFFs,
2241 (png_const_structrp png_ptr, png_const_inforp info_ptr,
2242 png_int_32 *offset_x, png_int_32 *offset_y, int *unit_type));
2243#endif
2244
2245#ifdef PNG_oFFs_SUPPORTED
2246PNG_EXPORT(146, void, png_set_oFFs,
2247 (png_const_structrp png_ptr, png_inforp info_ptr,
2248 png_int_32 offset_x, png_int_32 offset_y, int unit_type));
2249#endif
2250
2251#ifdef PNG_pCAL_SUPPORTED
2252PNG_EXPORT(147, png_uint_32, png_get_pCAL,
2253 (png_const_structrp png_ptr, png_inforp info_ptr,
2254 png_charp *purpose, png_int_32 *X0, png_int_32 *X1,
2255 int *type, int *nparams, png_charp *units, png_charpp *params));
2256#endif
2257
2258#ifdef PNG_pCAL_SUPPORTED
2259PNG_EXPORT(148, void, png_set_pCAL,
2260 (png_const_structrp png_ptr, png_inforp info_ptr,
2261 png_const_charp purpose, png_int_32 X0, png_int_32 X1,
2262 int type, int nparams, png_const_charp units, png_charpp params));
2263#endif
2264
2265#ifdef PNG_pHYs_SUPPORTED
2266PNG_EXPORT(149, png_uint_32, png_get_pHYs,
2267 (png_const_structrp png_ptr, png_const_inforp info_ptr,
2268 png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type));
2269#endif
2270
2271#ifdef PNG_pHYs_SUPPORTED
2272PNG_EXPORT(150, void, png_set_pHYs,
2273 (png_const_structrp png_ptr, png_inforp info_ptr,
2274 png_uint_32 res_x, png_uint_32 res_y, int unit_type));
2275#endif
2276
2277PNG_EXPORT(151, png_uint_32, png_get_PLTE,
2278 (png_const_structrp png_ptr, png_inforp info_ptr,
2279 png_colorp *palette, int *num_palette));
2280
2281PNG_EXPORT(152, void, png_set_PLTE,
2282 (png_structrp png_ptr, png_inforp info_ptr,
2283 png_const_colorp palette, int num_palette));
2284
2285#ifdef PNG_sBIT_SUPPORTED
2286PNG_EXPORT(153, png_uint_32, png_get_sBIT,
2287 (png_const_structrp png_ptr, png_inforp info_ptr,
2288 png_color_8p *sig_bit));
2289#endif
2290
2291#ifdef PNG_sBIT_SUPPORTED
2292PNG_EXPORT(154, void, png_set_sBIT,
2293 (png_const_structrp png_ptr, png_inforp info_ptr,
2294 png_const_color_8p sig_bit));
2295#endif
2296
2297#ifdef PNG_sRGB_SUPPORTED
2298PNG_EXPORT(155, png_uint_32, png_get_sRGB,
2299 (png_const_structrp png_ptr, png_const_inforp info_ptr,
2300 int *file_srgb_intent));
2301#endif
2302
2303#ifdef PNG_sRGB_SUPPORTED
2304PNG_EXPORT(156, void, png_set_sRGB,
2305 (png_const_structrp png_ptr, png_inforp info_ptr, int srgb_intent));
2306PNG_EXPORT(157, void, png_set_sRGB_gAMA_and_cHRM,
2307 (png_const_structrp png_ptr, png_inforp info_ptr, int srgb_intent));
2308#endif
2309
2310#ifdef PNG_iCCP_SUPPORTED
2311PNG_EXPORT(158, png_uint_32, png_get_iCCP,
2312 (png_const_structrp png_ptr, png_inforp info_ptr,
2313 png_charpp name, int *compression_type,
2314 png_bytepp profile, png_uint_32 *proflen));
2315#endif
2316
2317#ifdef PNG_iCCP_SUPPORTED
2318PNG_EXPORT(159, void, png_set_iCCP,
2319 (png_const_structrp png_ptr, png_inforp info_ptr,
2320 png_const_charp name, int compression_type,
2321 png_const_bytep profile, png_uint_32 proflen));
2322#endif
2323
2324#ifdef PNG_sPLT_SUPPORTED
2325PNG_EXPORT(160, int, png_get_sPLT,
2326 (png_const_structrp png_ptr, png_inforp info_ptr,
2327 png_sPLT_tpp entries));
2328#endif
2329
2330#ifdef PNG_sPLT_SUPPORTED
2331PNG_EXPORT(161, void, png_set_sPLT,
2332 (png_const_structrp png_ptr, png_inforp info_ptr,
2333 png_const_sPLT_tp entries, int nentries));
2334#endif
2335
2336#ifdef PNG_TEXT_SUPPORTED
2337/* png_get_text also returns the number of text chunks in *num_text */
2338PNG_EXPORT(162, int, png_get_text,
2339 (png_const_structrp png_ptr, png_inforp info_ptr,
2340 png_textp *text_ptr, int *num_text));
2341#endif
2342
2343/* Note while png_set_text() will accept a structure whose text,
2344 * language, and translated keywords are NULL pointers, the structure
2345 * returned by png_get_text will always contain regular
2346 * zero-terminated C strings. They might be empty strings but
2347 * they will never be NULL pointers.
2348 */
2349
2350#ifdef PNG_TEXT_SUPPORTED
2351PNG_EXPORT(163, void, png_set_text,
2352 (png_const_structrp png_ptr, png_inforp info_ptr,
2353 png_const_textp text_ptr, int num_text));
2354#endif
2355
2356#ifdef PNG_tIME_SUPPORTED
2357PNG_EXPORT(164, png_uint_32, png_get_tIME,
2358 (png_const_structrp png_ptr, png_inforp info_ptr,
2359 png_timep *mod_time));
2360#endif
2361
2362#ifdef PNG_tIME_SUPPORTED
2363PNG_EXPORT(165, void, png_set_tIME,
2364 (png_const_structrp png_ptr, png_inforp info_ptr,
2365 png_const_timep mod_time));
2366#endif
2367
2368#ifdef PNG_tRNS_SUPPORTED
2369PNG_EXPORT(166, png_uint_32, png_get_tRNS,
2370 (png_const_structrp png_ptr, png_inforp info_ptr,
2371 png_bytep *trans_alpha, int *num_trans,
2372 png_color_16p *trans_color));
2373#endif
2374
2375#ifdef PNG_tRNS_SUPPORTED
2376PNG_EXPORT(167, void, png_set_tRNS,
2377 (png_structrp png_ptr, png_inforp info_ptr,
2378 png_const_bytep trans_alpha, int num_trans,
2379 png_const_color_16p trans_color));
2380#endif
2381
2382#ifdef PNG_sCAL_SUPPORTED
2383PNG_FP_EXPORT(168, png_uint_32, png_get_sCAL,
2384 (png_const_structrp png_ptr, png_const_inforp info_ptr,
2385 int *unit, double *width, double *height))
2386#if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || \
2387 defined(PNG_FLOATING_POINT_SUPPORTED)
2388/* NOTE: this API is currently implemented using floating point arithmetic,
2389 * consequently it can only be used on systems with floating point support.
2390 * In any case the range of values supported by png_fixed_point is small and it
2391 * is highly recommended that png_get_sCAL_s be used instead.
2392 */
2393PNG_FIXED_EXPORT(214, png_uint_32, png_get_sCAL_fixed,
2394 (png_const_structrp png_ptr, png_const_inforp info_ptr,
2395 int *unit, png_fixed_point *width, png_fixed_point *height))
2396#endif
2397PNG_EXPORT(169, png_uint_32, png_get_sCAL_s,
2398 (png_const_structrp png_ptr, png_const_inforp info_ptr,
2399 int *unit, png_charpp swidth, png_charpp sheight));
2400
2401PNG_FP_EXPORT(170, void, png_set_sCAL,
2402 (png_const_structrp png_ptr, png_inforp info_ptr,
2403 int unit, double width, double height))
2404PNG_FIXED_EXPORT(213, void, png_set_sCAL_fixed,
2405 (png_const_structrp png_ptr, png_inforp info_ptr,
2406 int unit, png_fixed_point width, png_fixed_point height))
2407PNG_EXPORT(171, void, png_set_sCAL_s,
2408 (png_const_structrp png_ptr, png_inforp info_ptr,
2409 int unit, png_const_charp swidth, png_const_charp sheight));
2410#endif /* sCAL */
2411
2412#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
2413/* Provide the default handling for all unknown chunks or, optionally, for
2414 * specific unknown chunks.
2415 *
2416 * NOTE: prior to 1.6.0 the handling specified for particular chunks on read was
2417 * ignored and the default was used, the per-chunk setting only had an effect on
2418 * write. If you wish to have chunk-specific handling on read in code that must
2419 * work on earlier versions you must use a user chunk callback to specify the
2420 * desired handling (keep or discard.)
2421 *
2422 * The 'keep' parameter is a PNG_HANDLE_CHUNK_ value as listed below. The
2423 * parameter is interpreted as follows:
2424 *
2425 * READ:
2426 * PNG_HANDLE_CHUNK_AS_DEFAULT:
2427 * Known chunks: do normal libpng processing, do not keep the chunk (but
2428 * see the comments below about PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
2429 * Unknown chunks: for a specific chunk use the global default, when used
2430 * as the default discard the chunk data.
2431 * PNG_HANDLE_CHUNK_NEVER:
2432 * Discard the chunk data.
2433 * PNG_HANDLE_CHUNK_IF_SAFE:
2434 * Keep the chunk data if the chunk is not critical else raise a chunk
2435 * error.
2436 * PNG_HANDLE_CHUNK_ALWAYS:
2437 * Keep the chunk data.
2438 *
2439 * If the chunk data is saved it can be retrieved using png_get_unknown_chunks,
2440 * below. Notice that specifying "AS_DEFAULT" as a global default is equivalent
2441 * to specifying "NEVER", however when "AS_DEFAULT" is used for specific chunks
2442 * it simply resets the behavior to the libpng default.
2443 *
2444 * INTERACTION WITH USER CHUNK CALLBACKS:
2445 * The per-chunk handling is always used when there is a png_user_chunk_ptr
2446 * callback and the callback returns 0; the chunk is then always stored *unless*
2447 * it is critical and the per-chunk setting is other than ALWAYS. Notice that
2448 * the global default is *not* used in this case. (In effect the per-chunk
2449 * value is incremented to at least IF_SAFE.)
2450 *
2451 * IMPORTANT NOTE: this behavior will change in libpng 1.7 - the global and
2452 * per-chunk defaults will be honored. If you want to preserve the current
2453 * behavior when your callback returns 0 you must set PNG_HANDLE_CHUNK_IF_SAFE
2454 * as the default - if you don't do this libpng 1.6 will issue a warning.
2455 *
2456 * If you want unhandled unknown chunks to be discarded in libpng 1.6 and
2457 * earlier simply return '1' (handled).
2458 *
2459 * PNG_HANDLE_AS_UNKNOWN_SUPPORTED:
2460 * If this is *not* set known chunks will always be handled by libpng and
2461 * will never be stored in the unknown chunk list. Known chunks listed to
2462 * png_set_keep_unknown_chunks will have no effect. If it is set then known
2463 * chunks listed with a keep other than AS_DEFAULT will *never* be processed
2464 * by libpng, in addition critical chunks must either be processed by the
2465 * callback or saved.
2466 *
2467 * The IHDR and IEND chunks must not be listed. Because this turns off the
2468 * default handling for chunks that would otherwise be recognized the
2469 * behavior of libpng transformations may well become incorrect!
2470 *
2471 * WRITE:
2472 * When writing chunks the options only apply to the chunks specified by
2473 * png_set_unknown_chunks (below), libpng will *always* write known chunks
2474 * required by png_set_ calls and will always write the core critical chunks
2475 * (as required for PLTE).
2476 *
2477 * Each chunk in the png_set_unknown_chunks list is looked up in the
2478 * png_set_keep_unknown_chunks list to find the keep setting, this is then
2479 * interpreted as follows:
2480 *
2481 * PNG_HANDLE_CHUNK_AS_DEFAULT:
2482 * Write safe-to-copy chunks and write other chunks if the global
2483 * default is set to _ALWAYS, otherwise don't write this chunk.
2484 * PNG_HANDLE_CHUNK_NEVER:
2485 * Do not write the chunk.
2486 * PNG_HANDLE_CHUNK_IF_SAFE:
2487 * Write the chunk if it is safe-to-copy, otherwise do not write it.
2488 * PNG_HANDLE_CHUNK_ALWAYS:
2489 * Write the chunk.
2490 *
2491 * Note that the default behavior is effectively the opposite of the read case -
2492 * in read unknown chunks are not stored by default, in write they are written
2493 * by default. Also the behavior of PNG_HANDLE_CHUNK_IF_SAFE is very different
2494 * - on write the safe-to-copy bit is checked, on read the critical bit is
2495 * checked and on read if the chunk is critical an error will be raised.
2496 *
2497 * num_chunks:
2498 * ===========
2499 * If num_chunks is positive, then the "keep" parameter specifies the manner
2500 * for handling only those chunks appearing in the chunk_list array,
2501 * otherwise the chunk list array is ignored.
2502 *
2503 * If num_chunks is 0 the "keep" parameter specifies the default behavior for
2504 * unknown chunks, as described above.
2505 *
2506 * If num_chunks is negative, then the "keep" parameter specifies the manner
2507 * for handling all unknown chunks plus all chunks recognized by libpng
2508 * except for the IHDR, PLTE, tRNS, IDAT, and IEND chunks (which continue to
2509 * be processed by libpng.
2510 */
2511#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
2512PNG_EXPORT(172, void, png_set_keep_unknown_chunks,
2513 (png_structrp png_ptr,
2514 int keep, png_const_bytep chunk_list, int num_chunks));
2515#endif /* HANDLE_AS_UNKNOWN */
2516
2517/* The "keep" PNG_HANDLE_CHUNK_ parameter for the specified chunk is returned;
2518 * the result is therefore true (non-zero) if special handling is required,
2519 * false for the default handling.
2520 */
2521PNG_EXPORT(173, int, png_handle_as_unknown,
2522 (png_const_structrp png_ptr, png_const_bytep chunk_name));
2523#endif /* SET_UNKNOWN_CHUNKS */
2524
2525#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
2526PNG_EXPORT(174, void, png_set_unknown_chunks,
2527 (png_const_structrp png_ptr, png_inforp info_ptr,
2528 png_const_unknown_chunkp unknowns, int num_unknowns));
2529 /* NOTE: prior to 1.6.0 this routine set the 'location' field of the added
2530 * unknowns to the location currently stored in the png_struct. This is
2531 * invariably the wrong value on write. To fix this call the following API
2532 * for each chunk in the list with the correct location. If you know your
2533 * code won't be compiled on earlier versions you can rely on
2534 * png_set_unknown_chunks(write-ptr, png_get_unknown_chunks(read-ptr)) doing
2535 * the correct thing.
2536 */
2537
2538PNG_EXPORT(175, void, png_set_unknown_chunk_location,
2539 (png_const_structrp png_ptr, png_inforp info_ptr,
2540 int chunk, int location));
2541
2542PNG_EXPORT(176, int, png_get_unknown_chunks,
2543 (png_const_structrp png_ptr, png_inforp info_ptr,
2544 png_unknown_chunkpp entries));
2545#endif
2546
2547/* Png_free_data() will turn off the "valid" flag for anything it frees.
2548 * If you need to turn it off for a chunk that your application has freed,
2549 * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK);
2550 */
2551PNG_EXPORT(177, void, png_set_invalid,
2552 (png_const_structrp png_ptr, png_inforp info_ptr, int mask));
2553
2554#ifdef PNG_INFO_IMAGE_SUPPORTED
2555/* The "params" pointer is currently not used and is for future expansion. */
2556#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
2557PNG_EXPORT(178, void, png_read_png,
2558 (png_structrp png_ptr, png_inforp info_ptr,
2559 int transforms, png_voidp params));
2560#endif
2561#ifdef PNG_WRITE_SUPPORTED
2562PNG_EXPORT(179, void, png_write_png,
2563 (png_structrp png_ptr, png_inforp info_ptr,
2564 int transforms, png_voidp params));
2565#endif
2566#endif
2567
2568PNG_EXPORT(180, png_const_charp, png_get_copyright,
2569 (png_const_structrp png_ptr));
2570PNG_EXPORT(181, png_const_charp, png_get_header_ver,
2571 (png_const_structrp png_ptr));
2572PNG_EXPORT(182, png_const_charp, png_get_header_version,
2573 (png_const_structrp png_ptr));
2574PNG_EXPORT(183, png_const_charp, png_get_libpng_ver,
2575 (png_const_structrp png_ptr));
2576
2577#ifdef PNG_MNG_FEATURES_SUPPORTED
2578PNG_EXPORT(184, png_uint_32, png_permit_mng_features,
2579 (png_structrp png_ptr, png_uint_32 mng_features_permitted));
2580#endif
2581
2582/* For use in png_set_keep_unknown, added to version 1.2.6 */
2583#define PNG_HANDLE_CHUNK_AS_DEFAULT 0
2584#define PNG_HANDLE_CHUNK_NEVER 1
2585#define PNG_HANDLE_CHUNK_IF_SAFE 2
2586#define PNG_HANDLE_CHUNK_ALWAYS 3
2587#define PNG_HANDLE_CHUNK_LAST 4
2588
2589/* Strip the prepended error numbers ("#nnn ") from error and warning
2590 * messages before passing them to the error or warning handler.
2591 */
2592#ifdef PNG_ERROR_NUMBERS_SUPPORTED
2593PNG_EXPORT(185, void, png_set_strip_error_numbers,
2594 (png_structrp png_ptr, png_uint_32 strip_mode));
2595#endif
2596
2597/* Added in libpng-1.2.6 */
2598#ifdef PNG_SET_USER_LIMITS_SUPPORTED
2599PNG_EXPORT(186, void, png_set_user_limits,
2600 (png_structrp png_ptr,
2601 png_uint_32 user_width_max, png_uint_32 user_height_max));
2602PNG_EXPORT(187, png_uint_32, png_get_user_width_max,
2603 (png_const_structrp png_ptr));
2604PNG_EXPORT(188, png_uint_32, png_get_user_height_max,
2605 (png_const_structrp png_ptr));
2606/* Added in libpng-1.4.0 */
2607PNG_EXPORT(189, void, png_set_chunk_cache_max,
2608 (png_structrp png_ptr, png_uint_32 user_chunk_cache_max));
2609PNG_EXPORT(190, png_uint_32, png_get_chunk_cache_max,
2610 (png_const_structrp png_ptr));
2611/* Added in libpng-1.4.1 */
2612PNG_EXPORT(191, void, png_set_chunk_malloc_max,
2613 (png_structrp png_ptr, png_alloc_size_t user_chunk_cache_max));
2614PNG_EXPORT(192, png_alloc_size_t, png_get_chunk_malloc_max,
2615 (png_const_structrp png_ptr));
2616#endif
2617
2618#if defined(PNG_INCH_CONVERSIONS_SUPPORTED)
2619PNG_EXPORT(193, png_uint_32, png_get_pixels_per_inch,
2620 (png_const_structrp png_ptr, png_const_inforp info_ptr));
2621
2622PNG_EXPORT(194, png_uint_32, png_get_x_pixels_per_inch,
2623 (png_const_structrp png_ptr, png_const_inforp info_ptr));
2624
2625PNG_EXPORT(195, png_uint_32, png_get_y_pixels_per_inch,
2626 (png_const_structrp png_ptr, png_const_inforp info_ptr));
2627
2628PNG_FP_EXPORT(196, float, png_get_x_offset_inches,
2629 (png_const_structrp png_ptr, png_const_inforp info_ptr))
2630#ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */
2631PNG_FIXED_EXPORT(211, png_fixed_point, png_get_x_offset_inches_fixed,
2632 (png_const_structrp png_ptr, png_const_inforp info_ptr))
2633#endif
2634
2635PNG_FP_EXPORT(197, float, png_get_y_offset_inches,
2636 (png_const_structrp png_ptr, png_const_inforp info_ptr))
2637#ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */
2638PNG_FIXED_EXPORT(212, png_fixed_point, png_get_y_offset_inches_fixed,
2639 (png_const_structrp png_ptr, png_const_inforp info_ptr))
2640#endif
2641
2642# ifdef PNG_pHYs_SUPPORTED
2643PNG_EXPORT(198, png_uint_32, png_get_pHYs_dpi,
2644 (png_const_structrp png_ptr, png_const_inforp info_ptr,
2645 png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type));
2646# endif /* pHYs */
2647#endif /* INCH_CONVERSIONS */
2648
2649/* Added in libpng-1.4.0 */
2650#ifdef PNG_IO_STATE_SUPPORTED
2651PNG_EXPORT(199, png_uint_32, png_get_io_state,
2652 (png_const_structrp png_ptr));
2653
2654/* Removed from libpng 1.6; use png_get_io_chunk_type. */
2655PNG_REMOVED(200, png_const_bytep, png_get_io_chunk_name,
2656 (png_structrp png_ptr),
2657 PNG_DEPRECATED)
2658
2659PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type,
2660 (png_const_structrp png_ptr));
2661
2662/* The flags returned by png_get_io_state() are the following: */
2663# define PNG_IO_NONE 0x0000 /* no I/O at this moment */
2664# define PNG_IO_READING 0x0001 /* currently reading */
2665# define PNG_IO_WRITING 0x0002 /* currently writing */
2666# define PNG_IO_SIGNATURE 0x0010 /* currently at the file signature */
2667# define PNG_IO_CHUNK_HDR 0x0020 /* currently at the chunk header */
2668# define PNG_IO_CHUNK_DATA 0x0040 /* currently at the chunk data */
2669# define PNG_IO_CHUNK_CRC 0x0080 /* currently at the chunk crc */
2670# define PNG_IO_MASK_OP 0x000f /* current operation: reading/writing */
2671# define PNG_IO_MASK_LOC 0x00f0 /* current location: sig/hdr/data/crc */
2672#endif /* IO_STATE */
2673
2674/* Interlace support. The following macros are always defined so that if
2675 * libpng interlace handling is turned off the macros may be used to handle
2676 * interlaced images within the application.
2677 */
2678#define PNG_INTERLACE_ADAM7_PASSES 7
2679
2680/* Two macros to return the first row and first column of the original,
2681 * full, image which appears in a given pass. 'pass' is in the range 0
2682 * to 6 and the result is in the range 0 to 7.
2683 */
2684#define PNG_PASS_START_ROW(pass) (((1&~(pass))<<(3-((pass)>>1)))&7)
2685#define PNG_PASS_START_COL(pass) (((1& (pass))<<(3-(((pass)+1)>>1)))&7)
2686
2687/* A macro to return the offset between pixels in the output row for a pair of
2688 * pixels in the input - effectively the inverse of the 'COL_SHIFT' macro that
2689 * follows. Note that ROW_OFFSET is the offset from one row to the next whereas
2690 * COL_OFFSET is from one column to the next, within a row.
2691 */
2692#define PNG_PASS_ROW_OFFSET(pass) ((pass)>2?(8>>(((pass)-1)>>1)):8)
2693#define PNG_PASS_COL_OFFSET(pass) (1<<((7-(pass))>>1))
2694
2695/* Two macros to help evaluate the number of rows or columns in each
2696 * pass. This is expressed as a shift - effectively log2 of the number or
2697 * rows or columns in each 8x8 tile of the original image.
2698 */
2699#define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3)
2700#define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3)
2701
2702/* Hence two macros to determine the number of rows or columns in a given
2703 * pass of an image given its height or width. In fact these macros may
2704 * return non-zero even though the sub-image is empty, because the other
2705 * dimension may be empty for a small image.
2706 */
2707#define PNG_PASS_ROWS(height, pass) (((height)+(((1<<PNG_PASS_ROW_SHIFT(pass))\
2708 -1)-PNG_PASS_START_ROW(pass)))>>PNG_PASS_ROW_SHIFT(pass))
2709#define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\
2710 -1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass))
2711
2712/* For the reader row callbacks (both progressive and sequential) it is
2713 * necessary to find the row in the output image given a row in an interlaced
2714 * image, so two more macros:
2715 */
2716#define PNG_ROW_FROM_PASS_ROW(y_in, pass) \
2717 (((y_in)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass))
2718#define PNG_COL_FROM_PASS_COL(x_in, pass) \
2719 (((x_in)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass))
2720
2721/* Two macros which return a boolean (0 or 1) saying whether the given row
2722 * or column is in a particular pass. These use a common utility macro that
2723 * returns a mask for a given pass - the offset 'off' selects the row or
2724 * column version. The mask has the appropriate bit set for each column in
2725 * the tile.
2726 */
2727#define PNG_PASS_MASK(pass,off) ( \
2728 ((0x110145AF>>(((7-(off))-(pass))<<2)) & 0xF) | \
2729 ((0x01145AF0>>(((7-(off))-(pass))<<2)) & 0xF0))
2730
2731#define PNG_ROW_IN_INTERLACE_PASS(y, pass) \
2732 ((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1)
2733#define PNG_COL_IN_INTERLACE_PASS(x, pass) \
2734 ((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1)
2735
2736#ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
2737/* With these routines we avoid an integer divide, which will be slower on
2738 * most machines. However, it does take more operations than the corresponding
2739 * divide method, so it may be slower on a few RISC systems. There are two
2740 * shifts (by 8 or 16 bits) and an addition, versus a single integer divide.
2741 *
2742 * Note that the rounding factors are NOT supposed to be the same! 128 and
2743 * 32768 are correct for the NODIV code; 127 and 32767 are correct for the
2744 * standard method.
2745 *
2746 * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
2747 */
2748
2749 /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */
2750
2751# define png_composite(composite, fg, alpha, bg) \
2752 { \
2753 png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \
2754 * (png_uint_16)(alpha) \
2755 + (png_uint_16)(bg)*(png_uint_16)(255 \
2756 - (png_uint_16)(alpha)) + 128); \
2757 (composite) = (png_byte)(((temp + (temp >> 8)) >> 8) & 0xff); \
2758 }
2759
2760# define png_composite_16(composite, fg, alpha, bg) \
2761 { \
2762 png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) \
2763 * (png_uint_32)(alpha) \
2764 + (png_uint_32)(bg)*(65535 \
2765 - (png_uint_32)(alpha)) + 32768); \
2766 (composite) = (png_uint_16)(0xffff & ((temp + (temp >> 16)) >> 16)); \
2767 }
2768
2769#else /* Standard method using integer division */
2770
2771# define png_composite(composite, fg, alpha, bg) \
2772 (composite) = \
2773 (png_byte)(0xff & (((png_uint_16)(fg) * (png_uint_16)(alpha) + \
2774 (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \
2775 127) / 255))
2776
2777# define png_composite_16(composite, fg, alpha, bg) \
2778 (composite) = \
2779 (png_uint_16)(0xffff & (((png_uint_32)(fg) * (png_uint_32)(alpha) + \
2780 (png_uint_32)(bg)*(png_uint_32)(65535 - (png_uint_32)(alpha)) + \
2781 32767) / 65535))
2782#endif /* READ_COMPOSITE_NODIV */
2783
2784#ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED
2785PNG_EXPORT(201, png_uint_32, png_get_uint_32,
2786 (png_const_bytep buf));
2787PNG_EXPORT(202, png_uint_16, png_get_uint_16,
2788 (png_const_bytep buf));
2789PNG_EXPORT(203, png_int_32, png_get_int_32,
2790 (png_const_bytep buf));
2791#endif
2792
2793PNG_EXPORT(204, png_uint_32, png_get_uint_31,
2794 (png_const_structrp png_ptr, png_const_bytep buf));
2795/* No png_get_int_16 -- may be added if there's a real need for it. */
2796
2797/* Place a 32-bit number into a buffer in PNG byte order (big-endian). */
2798#ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
2799PNG_EXPORT(205, void, png_save_uint_32,
2800 (png_bytep buf, png_uint_32 i));
2801#endif
2802#ifdef PNG_SAVE_INT_32_SUPPORTED
2803PNG_EXPORT(206, void, png_save_int_32,
2804 (png_bytep buf, png_int_32 i));
2805#endif
2806
2807/* Place a 16-bit number into a buffer in PNG byte order.
2808 * The parameter is declared unsigned int, not png_uint_16,
2809 * just to avoid potential problems on pre-ANSI C compilers.
2810 */
2811#ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
2812PNG_EXPORT(207, void, png_save_uint_16,
2813 (png_bytep buf, unsigned int i));
2814/* No png_save_int_16 -- may be added if there's a real need for it. */
2815#endif
2816
2817#ifdef PNG_USE_READ_MACROS
2818/* Inline macros to do direct reads of bytes from the input buffer.
2819 * The png_get_int_32() routine assumes we are using two's complement
2820 * format for negative values, which is almost certainly true.
2821 */
2822# define PNG_get_uint_32(buf) \
2823 (((png_uint_32)(*(buf)) << 24) + \
2824 ((png_uint_32)(*((buf) + 1)) << 16) + \
2825 ((png_uint_32)(*((buf) + 2)) << 8) + \
2826 ((png_uint_32)(*((buf) + 3))))
2827
2828 /* From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the
2829 * function) incorrectly returned a value of type png_uint_32.
2830 */
2831# define PNG_get_uint_16(buf) \
2832 ((png_uint_16) \
2833 (((unsigned int)(*(buf)) << 8) + \
2834 ((unsigned int)(*((buf) + 1)))))
2835
2836# define PNG_get_int_32(buf) \
2837 ((png_int_32)((*(buf) & 0x80) \
2838 ? -((png_int_32)(((png_get_uint_32(buf)^0xffffffffU)+1U)&0x7fffffffU)) \
2839 : (png_int_32)png_get_uint_32(buf)))
2840
2841/* If PNG_PREFIX is defined the same thing as below happens in pnglibconf.h,
2842 * but defining a macro name prefixed with PNG_PREFIX.
2843 */
2844# ifndef PNG_PREFIX
2845# define png_get_uint_32(buf) PNG_get_uint_32(buf)
2846# define png_get_uint_16(buf) PNG_get_uint_16(buf)
2847# define png_get_int_32(buf) PNG_get_int_32(buf)
2848# endif
2849#else
2850# ifdef PNG_PREFIX
2851 /* No macros; revert to the (redefined) function */
2852# define PNG_get_uint_32 (png_get_uint_32)
2853# define PNG_get_uint_16 (png_get_uint_16)
2854# define PNG_get_int_32 (png_get_int_32)
2855# endif
2856#endif
2857
2858#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
2859PNG_EXPORT(242, void, png_set_check_for_invalid_index,
2860 (png_structrp png_ptr, int allowed));
2861# ifdef PNG_GET_PALETTE_MAX_SUPPORTED
2862PNG_EXPORT(243, int, png_get_palette_max,
2863 (png_const_structp png_ptr, png_const_infop info_ptr));
2864# endif
2865#endif /* CHECK_FOR_INVALID_INDEX */
2866
2867/*******************************************************************************
2868 * Section 5: SIMPLIFIED API
2869 *******************************************************************************
2870 *
2871 * Please read the documentation in libpng-manual.txt (TODO: write said
2872 * documentation) if you don't understand what follows.
2873 *
2874 * The simplified API hides the details of both libpng and the PNG file format
2875 * itself. It allows PNG files to be read into a very limited number of
2876 * in-memory bitmap formats or to be written from the same formats. If these
2877 * formats do not accommodate your needs then you can, and should, use the more
2878 * sophisticated APIs above - these support a wide variety of in-memory formats
2879 * and a wide variety of sophisticated transformations to those formats as well
2880 * as a wide variety of APIs to manipulate ancillary information.
2881 *
2882 * To read a PNG file using the simplified API:
2883 *
2884 * 1) Declare a 'png_image' structure (see below) on the stack, set the
2885 * version field to PNG_IMAGE_VERSION and the 'opaque' pointer to NULL
2886 * (this is REQUIRED, your program may crash if you don't do it.)
2887 * 2) Call the appropriate png_image_begin_read... function.
2888 * 3) Set the png_image 'format' member to the required sample format.
2889 * 4) Allocate a buffer for the image and, if required, the color-map.
2890 * 5) Call png_image_finish_read to read the image and, if required, the
2891 * color-map into your buffers.
2892 *
2893 * There are no restrictions on the format of the PNG input itself; all valid
2894 * color types, bit depths, and interlace methods are acceptable, and the
2895 * input image is transformed as necessary to the requested in-memory format
2896 * during the png_image_finish_read() step. The only caveat is that if you
2897 * request a color-mapped image from a PNG that is full-color or makes
2898 * complex use of an alpha channel the transformation is extremely lossy and the
2899 * result may look terrible.
2900 *
2901 * To write a PNG file using the simplified API:
2902 *
2903 * 1) Declare a 'png_image' structure on the stack and memset() it to all zero.
2904 * 2) Initialize the members of the structure that describe the image, setting
2905 * the 'format' member to the format of the image samples.
2906 * 3) Call the appropriate png_image_write... function with a pointer to the
2907 * image and, if necessary, the color-map to write the PNG data.
2908 *
2909 * png_image is a structure that describes the in-memory format of an image
2910 * when it is being read or defines the in-memory format of an image that you
2911 * need to write:
2912 */
2913#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) || \
2914 defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
2915
2916#define PNG_IMAGE_VERSION 1
2917
2918typedef struct png_control *png_controlp;
2919typedef struct
2920{
2921 png_controlp opaque; /* Initialize to NULL, free with png_image_free */
2922 png_uint_32 version; /* Set to PNG_IMAGE_VERSION */
2923 png_uint_32 width; /* Image width in pixels (columns) */
2924 png_uint_32 height; /* Image height in pixels (rows) */
2925 png_uint_32 format; /* Image format as defined below */
2926 png_uint_32 flags; /* A bit mask containing informational flags */
2927 png_uint_32 colormap_entries;
2928 /* Number of entries in the color-map */
2929
2930 /* In the event of an error or warning the following field will be set to a
2931 * non-zero value and the 'message' field will contain a '\0' terminated
2932 * string with the libpng error or warning message. If both warnings and
2933 * an error were encountered, only the error is recorded. If there
2934 * are multiple warnings, only the first one is recorded.
2935 *
2936 * The upper 30 bits of this value are reserved, the low two bits contain
2937 * a value as follows:
2938 */
2939# define PNG_IMAGE_WARNING 1
2940# define PNG_IMAGE_ERROR 2
2941 /*
2942 * The result is a two-bit code such that a value more than 1 indicates
2943 * a failure in the API just called:
2944 *
2945 * 0 - no warning or error
2946 * 1 - warning
2947 * 2 - error
2948 * 3 - error preceded by warning
2949 */
2950# define PNG_IMAGE_FAILED(png_cntrl) ((((png_cntrl).warning_or_error)&0x03)>1)
2951
2952 png_uint_32 warning_or_error;
2953
2954 char message[64];
2955} png_image, *png_imagep;
2956
2957/* The samples of the image have one to four channels whose components have
2958 * original values in the range 0 to 1.0:
2959 *
2960 * 1: A single gray or luminance channel (G).
2961 * 2: A gray/luminance channel and an alpha channel (GA).
2962 * 3: Three red, green, blue color channels (RGB).
2963 * 4: Three color channels and an alpha channel (RGBA).
2964 *
2965 * The components are encoded in one of two ways:
2966 *
2967 * a) As a small integer, value 0..255, contained in a single byte. For the
2968 * alpha channel the original value is simply value/255. For the color or
2969 * luminance channels the value is encoded according to the sRGB specification
2970 * and matches the 8-bit format expected by typical display devices.
2971 *
2972 * The color/gray channels are not scaled (pre-multiplied) by the alpha
2973 * channel and are suitable for passing to color management software.
2974 *
2975 * b) As a value in the range 0..65535, contained in a 2-byte integer. All
2976 * channels can be converted to the original value by dividing by 65535; all
2977 * channels are linear. Color channels use the RGB encoding (RGB end-points) of
2978 * the sRGB specification. This encoding is identified by the
2979 * PNG_FORMAT_FLAG_LINEAR flag below.
2980 *
2981 * When the simplified API needs to convert between sRGB and linear colorspaces,
2982 * the actual sRGB transfer curve defined in the sRGB specification (see the
2983 * article at <https://en.wikipedia.org/wiki/SRGB>) is used, not the gamma=1/2.2
2984 * approximation used elsewhere in libpng.
2985 *
2986 * When an alpha channel is present it is expected to denote pixel coverage
2987 * of the color or luminance channels and is returned as an associated alpha
2988 * channel: the color/gray channels are scaled (pre-multiplied) by the alpha
2989 * value.
2990 *
2991 * The samples are either contained directly in the image data, between 1 and 8
2992 * bytes per pixel according to the encoding, or are held in a color-map indexed
2993 * by bytes in the image data. In the case of a color-map the color-map entries
2994 * are individual samples, encoded as above, and the image data has one byte per
2995 * pixel to select the relevant sample from the color-map.
2996 */
2997
2998/* PNG_FORMAT_*
2999 *
3000 * #defines to be used in png_image::format. Each #define identifies a
3001 * particular layout of sample data and, if present, alpha values. There are
3002 * separate defines for each of the two component encodings.
3003 *
3004 * A format is built up using single bit flag values. All combinations are
3005 * valid. Formats can be built up from the flag values or you can use one of
3006 * the predefined values below. When testing formats always use the FORMAT_FLAG
3007 * macros to test for individual features - future versions of the library may
3008 * add new flags.
3009 *
3010 * When reading or writing color-mapped images the format should be set to the
3011 * format of the entries in the color-map then png_image_{read,write}_colormap
3012 * called to read or write the color-map and set the format correctly for the
3013 * image data. Do not set the PNG_FORMAT_FLAG_COLORMAP bit directly!
3014 *
3015 * NOTE: libpng can be built with particular features disabled. If you see
3016 * compiler errors because the definition of one of the following flags has been
3017 * compiled out it is because libpng does not have the required support. It is
3018 * possible, however, for the libpng configuration to enable the format on just
3019 * read or just write; in that case you may see an error at run time. You can
3020 * guard against this by checking for the definition of the appropriate
3021 * "_SUPPORTED" macro, one of:
3022 *
3023 * PNG_SIMPLIFIED_{READ,WRITE}_{BGR,AFIRST}_SUPPORTED
3024 */
3025#define PNG_FORMAT_FLAG_ALPHA 0x01U /* format with an alpha channel */
3026#define PNG_FORMAT_FLAG_COLOR 0x02U /* color format: otherwise grayscale */
3027#define PNG_FORMAT_FLAG_LINEAR 0x04U /* 2-byte channels else 1-byte */
3028#define PNG_FORMAT_FLAG_COLORMAP 0x08U /* image data is color-mapped */
3029
3030#ifdef PNG_FORMAT_BGR_SUPPORTED
3031# define PNG_FORMAT_FLAG_BGR 0x10U /* BGR colors, else order is RGB */
3032#endif
3033
3034#ifdef PNG_FORMAT_AFIRST_SUPPORTED
3035# define PNG_FORMAT_FLAG_AFIRST 0x20U /* alpha channel comes first */
3036#endif
3037
3038#define PNG_FORMAT_FLAG_ASSOCIATED_ALPHA 0x40U /* alpha channel is associated */
3039
3040/* Commonly used formats have predefined macros.
3041 *
3042 * First the single byte (sRGB) formats:
3043 */
3044#define PNG_FORMAT_GRAY 0
3045#define PNG_FORMAT_GA PNG_FORMAT_FLAG_ALPHA
3046#define PNG_FORMAT_AG (PNG_FORMAT_GA|PNG_FORMAT_FLAG_AFIRST)
3047#define PNG_FORMAT_RGB PNG_FORMAT_FLAG_COLOR
3048#define PNG_FORMAT_BGR (PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_BGR)
3049#define PNG_FORMAT_RGBA (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_ALPHA)
3050#define PNG_FORMAT_ARGB (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_AFIRST)
3051#define PNG_FORMAT_BGRA (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_ALPHA)
3052#define PNG_FORMAT_ABGR (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_AFIRST)
3053
3054/* Then the linear 2-byte formats. When naming these "Y" is used to
3055 * indicate a luminance (gray) channel.
3056 */
3057#define PNG_FORMAT_LINEAR_Y PNG_FORMAT_FLAG_LINEAR
3058#define PNG_FORMAT_LINEAR_Y_ALPHA (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_ALPHA)
3059#define PNG_FORMAT_LINEAR_RGB (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR)
3060#define PNG_FORMAT_LINEAR_RGB_ALPHA \
3061 (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA)
3062
3063/* With color-mapped formats the image data is one byte for each pixel, the byte
3064 * is an index into the color-map which is formatted as above. To obtain a
3065 * color-mapped format it is sufficient just to add the PNG_FOMAT_FLAG_COLORMAP
3066 * to one of the above definitions, or you can use one of the definitions below.
3067 */
3068#define PNG_FORMAT_RGB_COLORMAP (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_COLORMAP)
3069#define PNG_FORMAT_BGR_COLORMAP (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_COLORMAP)
3070#define PNG_FORMAT_RGBA_COLORMAP (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_COLORMAP)
3071#define PNG_FORMAT_ARGB_COLORMAP (PNG_FORMAT_ARGB|PNG_FORMAT_FLAG_COLORMAP)
3072#define PNG_FORMAT_BGRA_COLORMAP (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_COLORMAP)
3073#define PNG_FORMAT_ABGR_COLORMAP (PNG_FORMAT_ABGR|PNG_FORMAT_FLAG_COLORMAP)
3074
3075/* PNG_IMAGE macros
3076 *
3077 * These are convenience macros to derive information from a png_image
3078 * structure. The PNG_IMAGE_SAMPLE_ macros return values appropriate to the
3079 * actual image sample values - either the entries in the color-map or the
3080 * pixels in the image. The PNG_IMAGE_PIXEL_ macros return corresponding values
3081 * for the pixels and will always return 1 for color-mapped formats. The
3082 * remaining macros return information about the rows in the image and the
3083 * complete image.
3084 *
3085 * NOTE: All the macros that take a png_image::format parameter are compile time
3086 * constants if the format parameter is, itself, a constant. Therefore these
3087 * macros can be used in array declarations and case labels where required.
3088 * Similarly the macros are also pre-processor constants (sizeof is not used) so
3089 * they can be used in #if tests.
3090 *
3091 * First the information about the samples.
3092 */
3093#define PNG_IMAGE_SAMPLE_CHANNELS(fmt)\
3094 (((fmt)&(PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA))+1)
3095 /* Return the total number of channels in a given format: 1..4 */
3096
3097#define PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)\
3098 ((((fmt) & PNG_FORMAT_FLAG_LINEAR) >> 2)+1)
3099 /* Return the size in bytes of a single component of a pixel or color-map
3100 * entry (as appropriate) in the image: 1 or 2.
3101 */
3102
3103#define PNG_IMAGE_SAMPLE_SIZE(fmt)\
3104 (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt))
3105 /* This is the size of the sample data for one sample. If the image is
3106 * color-mapped it is the size of one color-map entry (and image pixels are
3107 * one byte in size), otherwise it is the size of one image pixel.
3108 */
3109
3110#define PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(fmt)\
3111 (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * 256)
3112 /* The maximum size of the color-map required by the format expressed in a
3113 * count of components. This can be used to compile-time allocate a
3114 * color-map:
3115 *
3116 * png_uint_16 colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(linear_fmt)];
3117 *
3118 * png_byte colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(sRGB_fmt)];
3119 *
3120 * Alternatively use the PNG_IMAGE_COLORMAP_SIZE macro below to use the
3121 * information from one of the png_image_begin_read_ APIs and dynamically
3122 * allocate the required memory.
3123 */
3124
3125/* Corresponding information about the pixels */
3126#define PNG_IMAGE_PIXEL_(test,fmt)\
3127 (((fmt)&PNG_FORMAT_FLAG_COLORMAP)?1:test(fmt))
3128
3129#define PNG_IMAGE_PIXEL_CHANNELS(fmt)\
3130 PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_CHANNELS,fmt)
3131 /* The number of separate channels (components) in a pixel; 1 for a
3132 * color-mapped image.
3133 */
3134
3135#define PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt)\
3136 PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_COMPONENT_SIZE,fmt)
3137 /* The size, in bytes, of each component in a pixel; 1 for a color-mapped
3138 * image.
3139 */
3140
3141#define PNG_IMAGE_PIXEL_SIZE(fmt) PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_SIZE,fmt)
3142 /* The size, in bytes, of a complete pixel; 1 for a color-mapped image. */
3143
3144/* Information about the whole row, or whole image */
3145#define PNG_IMAGE_ROW_STRIDE(image)\
3146 (PNG_IMAGE_PIXEL_CHANNELS((image).format) * (image).width)
3147 /* Return the total number of components in a single row of the image; this
3148 * is the minimum 'row stride', the minimum count of components between each
3149 * row. For a color-mapped image this is the minimum number of bytes in a
3150 * row.
3151 *
3152 * WARNING: this macro overflows for some images with more than one component
3153 * and very large image widths. libpng will refuse to process an image where
3154 * this macro would overflow.
3155 */
3156
3157#define PNG_IMAGE_BUFFER_SIZE(image, row_stride)\
3158 (PNG_IMAGE_PIXEL_COMPONENT_SIZE((image).format)*(image).height*(row_stride))
3159 /* Return the size, in bytes, of an image buffer given a png_image and a row
3160 * stride - the number of components to leave space for in each row.
3161 *
3162 * WARNING: this macro overflows a 32-bit integer for some large PNG images,
3163 * libpng will refuse to process an image where such an overflow would occur.
3164 */
3165
3166#define PNG_IMAGE_SIZE(image)\
3167 PNG_IMAGE_BUFFER_SIZE(image, PNG_IMAGE_ROW_STRIDE(image))
3168 /* Return the size, in bytes, of the image in memory given just a png_image;
3169 * the row stride is the minimum stride required for the image.
3170 */
3171
3172#define PNG_IMAGE_COLORMAP_SIZE(image)\
3173 (PNG_IMAGE_SAMPLE_SIZE((image).format) * (image).colormap_entries)
3174 /* Return the size, in bytes, of the color-map of this image. If the image
3175 * format is not a color-map format this will return a size sufficient for
3176 * 256 entries in the given format; check PNG_FORMAT_FLAG_COLORMAP if
3177 * you don't want to allocate a color-map in this case.
3178 */
3179
3180/* PNG_IMAGE_FLAG_*
3181 *
3182 * Flags containing additional information about the image are held in the
3183 * 'flags' field of png_image.
3184 */
3185#define PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB 0x01
3186 /* This indicates that the RGB values of the in-memory bitmap do not
3187 * correspond to the red, green and blue end-points defined by sRGB.
3188 */
3189
3190#define PNG_IMAGE_FLAG_FAST 0x02
3191 /* On write emphasise speed over compression; the resultant PNG file will be
3192 * larger but will be produced significantly faster, particular for large
3193 * images. Do not use this option for images which will be distributed, only
3194 * used it when producing intermediate files that will be read back in
3195 * repeatedly. For a typical 24-bit image the option will double the read
3196 * speed at the cost of increasing the image size by 25%, however for many
3197 * more compressible images the PNG file can be 10 times larger with only a
3198 * slight speed gain.
3199 */
3200
3201#define PNG_IMAGE_FLAG_16BIT_sRGB 0x04
3202 /* On read if the image is a 16-bit per component image and there is no gAMA
3203 * or sRGB chunk assume that the components are sRGB encoded. Notice that
3204 * images output by the simplified API always have gamma information; setting
3205 * this flag only affects the interpretation of 16-bit images from an
3206 * external source. It is recommended that the application expose this flag
3207 * to the user; the user can normally easily recognize the difference between
3208 * linear and sRGB encoding. This flag has no effect on write - the data
3209 * passed to the write APIs must have the correct encoding (as defined
3210 * above.)
3211 *
3212 * If the flag is not set (the default) input 16-bit per component data is
3213 * assumed to be linear.
3214 *
3215 * NOTE: the flag can only be set after the png_image_begin_read_ call,
3216 * because that call initializes the 'flags' field.
3217 */
3218
3219#ifdef PNG_SIMPLIFIED_READ_SUPPORTED
3220/* READ APIs
3221 * ---------
3222 *
3223 * The png_image passed to the read APIs must have been initialized by setting
3224 * the png_controlp field 'opaque' to NULL (or, safer, memset the whole thing.)
3225 */
3226#ifdef PNG_STDIO_SUPPORTED
3227PNG_EXPORT(234, int, png_image_begin_read_from_file,
3228 (png_imagep image, const char *file_name));
3229 /* The named file is opened for read and the image header is filled in
3230 * from the PNG header in the file.
3231 */
3232
3233PNG_EXPORT(235, int, png_image_begin_read_from_stdio,
3234 (png_imagep image, FILE *file));
3235 /* The PNG header is read from the stdio FILE object. */
3236#endif /* STDIO */
3237
3238PNG_EXPORT(236, int, png_image_begin_read_from_memory,
3239 (png_imagep image, png_const_voidp memory, size_t size));
3240 /* The PNG header is read from the given memory buffer. */
3241
3242PNG_EXPORT(237, int, png_image_finish_read,
3243 (png_imagep image,
3244 png_const_colorp background, void *buffer, png_int_32 row_stride,
3245 void *colormap));
3246 /* Finish reading the image into the supplied buffer and clean up the
3247 * png_image structure.
3248 *
3249 * row_stride is the step, in byte or 2-byte units as appropriate,
3250 * between adjacent rows. A positive stride indicates that the top-most row
3251 * is first in the buffer - the normal top-down arrangement. A negative
3252 * stride indicates that the bottom-most row is first in the buffer.
3253 *
3254 * background need only be supplied if an alpha channel must be removed from
3255 * a png_byte format and the removal is to be done by compositing on a solid
3256 * color; otherwise it may be NULL and any composition will be done directly
3257 * onto the buffer. The value is an sRGB color to use for the background,
3258 * for grayscale output the green channel is used.
3259 *
3260 * background must be supplied when an alpha channel must be removed from a
3261 * single byte color-mapped output format, in other words if:
3262 *
3263 * 1) The original format from png_image_begin_read_from_* had
3264 * PNG_FORMAT_FLAG_ALPHA set.
3265 * 2) The format set by the application does not.
3266 * 3) The format set by the application has PNG_FORMAT_FLAG_COLORMAP set and
3267 * PNG_FORMAT_FLAG_LINEAR *not* set.
3268 *
3269 * For linear output removing the alpha channel is always done by compositing
3270 * on black and background is ignored.
3271 *
3272 * colormap must be supplied when PNG_FORMAT_FLAG_COLORMAP is set. It must
3273 * be at least the size (in bytes) returned by PNG_IMAGE_COLORMAP_SIZE.
3274 * image->colormap_entries will be updated to the actual number of entries
3275 * written to the colormap; this may be less than the original value.
3276 */
3277
3278PNG_EXPORT(238, void, png_image_free,
3279 (png_imagep image));
3280 /* Free any data allocated by libpng in image->opaque, setting the pointer to
3281 * NULL. May be called at any time after the structure is initialized.
3282 */
3283#endif /* SIMPLIFIED_READ */
3284
3285#ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED
3286/* WRITE APIS
3287 * ----------
3288 * For write you must initialize a png_image structure to describe the image to
3289 * be written. To do this use memset to set the whole structure to 0 then
3290 * initialize fields describing your image.
3291 *
3292 * version: must be set to PNG_IMAGE_VERSION
3293 * opaque: must be initialized to NULL
3294 * width: image width in pixels
3295 * height: image height in rows
3296 * format: the format of the data (image and color-map) you wish to write
3297 * flags: set to 0 unless one of the defined flags applies; set
3298 * PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB for color format images where the RGB
3299 * values do not correspond to the colors in sRGB.
3300 * colormap_entries: set to the number of entries in the color-map (0 to 256)
3301 */
3302#ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED
3303PNG_EXPORT(239, int, png_image_write_to_file,
3304 (png_imagep image,
3305 const char *file, int convert_to_8bit, const void *buffer,
3306 png_int_32 row_stride, const void *colormap));
3307 /* Write the image to the named file. */
3308
3309PNG_EXPORT(240, int, png_image_write_to_stdio,
3310 (png_imagep image,
3311 FILE *file, int convert_to_8_bit, const void *buffer,
3312 png_int_32 row_stride, const void *colormap));
3313 /* Write the image to the given FILE object. */
3314#endif /* SIMPLIFIED_WRITE_STDIO */
3315
3316/* With all write APIs if image is in one of the linear formats with 16-bit
3317 * data then setting convert_to_8_bit will cause the output to be an 8-bit PNG
3318 * gamma encoded according to the sRGB specification, otherwise a 16-bit linear
3319 * encoded PNG file is written.
3320 *
3321 * With color-mapped data formats the colormap parameter point to a color-map
3322 * with at least image->colormap_entries encoded in the specified format. If
3323 * the format is linear the written PNG color-map will be converted to sRGB
3324 * regardless of the convert_to_8_bit flag.
3325 *
3326 * With all APIs row_stride is handled as in the read APIs - it is the spacing
3327 * from one row to the next in component sized units (1 or 2 bytes) and if
3328 * negative indicates a bottom-up row layout in the buffer. If row_stride is
3329 * zero, libpng will calculate it for you from the image width and number of
3330 * channels.
3331 *
3332 * Note that the write API does not support interlacing, sub-8-bit pixels or
3333 * most ancillary chunks. If you need to write text chunks (e.g. for copyright
3334 * notices) you need to use one of the other APIs.
3335 */
3336
3337PNG_EXPORT(245, int, png_image_write_to_memory,
3338 (png_imagep image,
3339 void *memory, png_alloc_size_t * PNG_RESTRICT memory_bytes,
3340 int convert_to_8_bit,
3341 const void *buffer, png_int_32 row_stride, const void *colormap));
3342 /* Write the image to the given memory buffer. The function both writes the
3343 * whole PNG data stream to *memory and updates *memory_bytes with the count
3344 * of bytes written.
3345 *
3346 * 'memory' may be NULL. In this case *memory_bytes is not read however on
3347 * success the number of bytes which would have been written will still be
3348 * stored in *memory_bytes. On failure *memory_bytes will contain 0.
3349 *
3350 * If 'memory' is not NULL it must point to memory[*memory_bytes] of
3351 * writeable memory.
3352 *
3353 * If the function returns success memory[*memory_bytes] (if 'memory' is not
3354 * NULL) contains the written PNG data. *memory_bytes will always be less
3355 * than or equal to the original value.
3356 *
3357 * If the function returns false and *memory_bytes was not changed an error
3358 * occurred during write. If *memory_bytes was changed, or is not 0 if
3359 * 'memory' was NULL, the write would have succeeded but for the memory
3360 * buffer being too small. *memory_bytes contains the required number of
3361 * bytes and will be bigger that the original value.
3362 */
3363
3364#define png_image_write_get_memory_size(image, size, convert_to_8_bit, buffer,\
3365 row_stride, colormap)\
3366 png_image_write_to_memory(&(image), 0, &(size), convert_to_8_bit, buffer,\
3367 row_stride, colormap)
3368 /* Return the amount of memory in 'size' required to compress this image.
3369 * The png_image structure 'image' must be filled in as in the above
3370 * function and must not be changed before the actual write call, the buffer
3371 * and all other parameters must also be identical to that in the final
3372 * write call. The 'size' variable need not be initialized.
3373 *
3374 * NOTE: the macro returns true/false, if false is returned 'size' will be
3375 * set to zero and the write failed and probably will fail if tried again.
3376 */
3377
3378/* You can pre-allocate the buffer by making sure it is of sufficient size
3379 * regardless of the amount of compression achieved. The buffer size will
3380 * always be bigger than the original image and it will never be filled. The
3381 * following macros are provided to assist in allocating the buffer.
3382 */
3383#define PNG_IMAGE_DATA_SIZE(image) (PNG_IMAGE_SIZE(image)+(image).height)
3384 /* The number of uncompressed bytes in the PNG byte encoding of the image;
3385 * uncompressing the PNG IDAT data will give this number of bytes.
3386 *
3387 * NOTE: while PNG_IMAGE_SIZE cannot overflow for an image in memory this
3388 * macro can because of the extra bytes used in the PNG byte encoding. You
3389 * need to avoid this macro if your image size approaches 2^30 in width or
3390 * height. The same goes for the remainder of these macros; they all produce
3391 * bigger numbers than the actual in-memory image size.
3392 */
3393#ifndef PNG_ZLIB_MAX_SIZE
3394# define PNG_ZLIB_MAX_SIZE(b) ((b)+(((b)+7U)>>3)+(((b)+63U)>>6)+11U)
3395 /* An upper bound on the number of compressed bytes given 'b' uncompressed
3396 * bytes. This is based on deflateBounds() in zlib; different
3397 * implementations of zlib compression may conceivably produce more data so
3398 * if your zlib implementation is not zlib itself redefine this macro
3399 * appropriately.
3400 */
3401#endif
3402
3403#define PNG_IMAGE_COMPRESSED_SIZE_MAX(image)\
3404 PNG_ZLIB_MAX_SIZE((png_alloc_size_t)PNG_IMAGE_DATA_SIZE(image))
3405 /* An upper bound on the size of the data in the PNG IDAT chunks. */
3406
3407#define PNG_IMAGE_PNG_SIZE_MAX_(image, image_size)\
3408 ((8U/*sig*/+25U/*IHDR*/+16U/*gAMA*/+44U/*cHRM*/+12U/*IEND*/+\
3409 (((image).format&PNG_FORMAT_FLAG_COLORMAP)?/*colormap: PLTE, tRNS*/\
3410 12U+3U*(image).colormap_entries/*PLTE data*/+\
3411 (((image).format&PNG_FORMAT_FLAG_ALPHA)?\
3412 12U/*tRNS*/+(image).colormap_entries:0U):0U)+\
3413 12U)+(12U*((image_size)/PNG_ZBUF_SIZE))/*IDAT*/+(image_size))
3414 /* A helper for the following macro; if your compiler cannot handle the
3415 * following macro use this one with the result of
3416 * PNG_IMAGE_COMPRESSED_SIZE_MAX(image) as the second argument (most
3417 * compilers should handle this just fine.)
3418 */
3419
3420#define PNG_IMAGE_PNG_SIZE_MAX(image)\
3421 PNG_IMAGE_PNG_SIZE_MAX_(image, PNG_IMAGE_COMPRESSED_SIZE_MAX(image))
3422 /* An upper bound on the total length of the PNG data stream for 'image'.
3423 * The result is of type png_alloc_size_t, on 32-bit systems this may
3424 * overflow even though PNG_IMAGE_DATA_SIZE does not overflow; the write will
3425 * run out of buffer space but return a corrected size which should work.
3426 */
3427#endif /* SIMPLIFIED_WRITE */
3428/*******************************************************************************
3429 * END OF SIMPLIFIED API
3430 ******************************************************************************/
3431#endif /* SIMPLIFIED_{READ|WRITE} */
3432
3433/*******************************************************************************
3434 * Section 6: IMPLEMENTATION OPTIONS
3435 *******************************************************************************
3436 *
3437 * Support for arbitrary implementation-specific optimizations. The API allows
3438 * particular options to be turned on or off. 'Option' is the number of the
3439 * option and 'onoff' is 0 (off) or non-0 (on). The value returned is given
3440 * by the PNG_OPTION_ defines below.
3441 *
3442 * HARDWARE: normally hardware capabilities, such as the Intel SSE instructions,
3443 * are detected at run time, however sometimes it may be impossible
3444 * to do this in user mode, in which case it is necessary to discover
3445 * the capabilities in an OS specific way. Such capabilities are
3446 * listed here when libpng has support for them and must be turned
3447 * ON by the application if present.
3448 *
3449 * SOFTWARE: sometimes software optimizations actually result in performance
3450 * decrease on some architectures or systems, or with some sets of
3451 * PNG images. 'Software' options allow such optimizations to be
3452 * selected at run time.
3453 */
3454#ifdef PNG_SET_OPTION_SUPPORTED
3455
3456/* HARDWARE: ARM Neon SIMD instructions supported */
3457#ifdef PNG_ARM_NEON_API_SUPPORTED
3458# define PNG_ARM_NEON 0
3459#endif
3460
3461/* SOFTWARE: Force maximum window */
3462#define PNG_MAXIMUM_INFLATE_WINDOW 2
3463
3464/* SOFTWARE: Check ICC profile for sRGB */
3465#define PNG_SKIP_sRGB_CHECK_PROFILE 4
3466
3467/* HARDWARE: MIPS MSA SIMD instructions supported */
3468#ifdef PNG_MIPS_MSA_API_SUPPORTED
3469# define PNG_MIPS_MSA 6
3470#endif
3471
3472/* SOFTWARE: Disable Adler32 check on IDAT */
3473#ifdef PNG_DISABLE_ADLER32_CHECK_SUPPORTED
3474# define PNG_IGNORE_ADLER32 8
3475#endif
3476
3477/* HARDWARE: PowerPC VSX SIMD instructions supported */
3478#ifdef PNG_POWERPC_VSX_API_SUPPORTED
3479# define PNG_POWERPC_VSX 10
3480#endif
3481
3482/* HARDWARE: MIPS MMI SIMD instructions supported */
3483#ifdef PNG_MIPS_MMI_API_SUPPORTED
3484# define PNG_MIPS_MMI 12
3485#endif
3486
3487/* HARDWARE: RISC-V RVV SIMD instructions supported */
3488#ifdef PNG_RISCV_RVV_API_SUPPORTED
3489# define PNG_RISCV_RVV 14
3490#endif
3491
3492/* Next option - numbers must be even */
3493#define PNG_OPTION_NEXT 16
3494
3495/* Return values: NOTE: there are four values and 'off' is *not* zero */
3496#define PNG_OPTION_UNSET 0 /* Unset - defaults to off */
3497#define PNG_OPTION_INVALID 1 /* Option number out of range */
3498#define PNG_OPTION_OFF 2
3499#define PNG_OPTION_ON 3
3500
3501PNG_EXPORT(244, int, png_set_option, (png_structrp png_ptr, int option,
3502 int onoff));
3503#endif /* SET_OPTION */
3504
3505/*******************************************************************************
3506 * END OF HARDWARE AND SOFTWARE OPTIONS
3507 ******************************************************************************/
3508
3509/* Maintainer: Put new public prototypes here ^, in libpng.3, in project
3510 * defs, and in scripts/symbols.def.
3511 */
3512
3513/* The last ordinal number (this is the *last* one already used; the next
3514 * one to use is one more than this.)
3515 */
3516#ifdef PNG_EXPORT_LAST_ORDINAL
3517 PNG_EXPORT_LAST_ORDINAL(259);
3518#endif
3519
3520#ifdef __cplusplus
3521}
3522#endif
3523
3524#endif /* PNG_VERSION_INFO_ONLY */
3525/* Do not put anything past this line */
3526#endif /* PNG_H */
3527