1 /*
2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
3 *
4 * This code is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License version 2 only, as
6 * published by the Free Software Foundation. Oracle designates this
7 * particular file as subject to the "Classpath" exception as provided
8 * by Oracle in the LICENSE file that accompanied this code.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 */
24
25 /* png.h - header file for PNG reference library
26 *
27 * This file is available under and governed by the GNU General Public
28 * License version 2 only, as published by the Free Software Foundation.
29 * However, the following notice accompanied the original version of this
30 * file and, per its terms, should not be removed:
31 *
32 * libpng version 1.6.35, July 15, 2018
33 *
34 * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
35 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
36 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
37 *
38 * This code is released under the libpng license (See LICENSE, below)
39 *
40 * Authors and maintainers:
41 * libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
42 * libpng versions 0.89, June 1996, through 0.96, May 1997: Andreas Dilger
43 * libpng versions 0.97, January 1998, through 1.6.35, July 15, 2018:
44 * Glenn Randers-Pehrson.
45 * See also "Contributing Authors", below.
46 */
47
48 /*
49 * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
50 *
51 * If you modify libpng you may insert additional notices immediately following
52 * this sentence.
53 *
54 * This code is released under the libpng license.
55 *
56 * libpng versions 1.0.7, July 1, 2000 through 1.6.35, July 15, 2018 are
57 * Copyright (c) 2000-2002, 2004, 2006-2018 Glenn Randers-Pehrson, are
58 * derived from libpng-1.0.6, and are distributed according to the same
59 * disclaimer and license as libpng-1.0.6 with the following individuals
60 * added to the list of Contributing Authors:
61 *
62 * Simon-Pierre Cadieux
63 * Eric S. Raymond
64 * Mans Rullgard
65 * Cosmin Truta
66 * Gilles Vollant
67 * James Yu
68 * Mandar Sahastrabuddhe
69 * Google Inc.
70 * Vadim Barkov
71 *
72 * and with the following additions to the disclaimer:
73 *
74 * There is no warranty against interference with your enjoyment of the
75 * library or against infringement. There is no warranty that our
76 * efforts or the library will fulfill any of your particular purposes
77 * or needs. This library is provided with all faults, and the entire
78 * risk of satisfactory quality, performance, accuracy, and effort is with
79 * the user.
80 *
81 * Some files in the "contrib" directory and some configure-generated
82 * files that are distributed with libpng have other copyright owners and
83 * are released under other open source licenses.
84 *
85 * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
86 * Copyright (c) 1998-2000 Glenn Randers-Pehrson, are derived from
87 * libpng-0.96, and are distributed according to the same disclaimer and
88 * license as libpng-0.96, with the following individuals added to the list
89 * of Contributing Authors:
90 *
91 * Tom Lane
92 * Glenn Randers-Pehrson
93 * Willem van Schaik
94 *
95 * libpng versions 0.89, June 1996, through 0.96, May 1997, are
96 * Copyright (c) 1996-1997 Andreas Dilger, are derived from libpng-0.88,
97 * and are distributed according to the same disclaimer and license as
98 * libpng-0.88, with the following individuals added to the list of
99 * Contributing Authors:
100 *
101 * John Bowler
102 * Kevin Bracey
103 * Sam Bushell
104 * Magnus Holmgren
105 * Greg Roelofs
106 * Tom Tanner
107 *
108 * Some files in the "scripts" directory have other copyright owners
109 * but are released under this license.
110 *
111 * libpng versions 0.5, May 1995, through 0.88, January 1996, are
112 * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
113 *
114 * For the purposes of this copyright and license, "Contributing Authors"
115 * is defined as the following set of individuals:
116 *
117 * Andreas Dilger
118 * Dave Martindale
119 * Guy Eric Schalnat
120 * Paul Schmidt
121 * Tim Wegner
122 *
123 * The PNG Reference Library is supplied "AS IS". The Contributing Authors
124 * and Group 42, Inc. disclaim all warranties, expressed or implied,
125 * including, without limitation, the warranties of merchantability and of
126 * fitness for any purpose. The Contributing Authors and Group 42, Inc.
127 * assume no liability for direct, indirect, incidental, special, exemplary,
128 * or consequential damages, which may result from the use of the PNG
129 * Reference Library, even if advised of the possibility of such damage.
130 *
131 * Permission is hereby granted to use, copy, modify, and distribute this
132 * source code, or portions hereof, for any purpose, without fee, subject
133 * to the following restrictions:
134 *
135 * 1. The origin of this source code must not be misrepresented.
136 *
137 * 2. Altered versions must be plainly marked as such and must not
138 * be misrepresented as being the original source.
139 *
140 * 3. This Copyright notice may not be removed or altered from any
141 * source or altered source distribution.
142 *
143 * The Contributing Authors and Group 42, Inc. specifically permit, without
144 * fee, and encourage the use of this source code as a component to
145 * supporting the PNG file format in commercial products. If you use this
146 * source code in a product, acknowledgment is not required but would be
147 * appreciated.
148 *
149 * END OF COPYRIGHT NOTICE, DISCLAIMER, and LICENSE.
150 *
151 * TRADEMARK:
152 *
153 * The name "libpng" has not been registered by the Copyright owner
154 * as a trademark in any jurisdiction. However, because libpng has
155 * been distributed and maintained world-wide, continually since 1995,
156 * the Copyright owner claims "common-law trademark protection" in any
157 * jurisdiction where common-law trademark is recognized.
158 *
159 * OSI CERTIFICATION:
160 *
161 * Libpng is OSI Certified Open Source Software. OSI Certified Open Source is
162 * a certification mark of the Open Source Initiative. OSI has not addressed
163 * the additional disclaimers inserted at version 1.0.7.
164 *
165 * EXPORT CONTROL:
166 *
167 * The Copyright owner believes that the Export Control Classification
168 * Number (ECCN) for libpng is EAR99, which means not subject to export
169 * controls or International Traffic in Arms Regulations (ITAR) because
170 * it is open source, publicly available software, that does not contain
171 * any encryption software. See the EAR, paragraphs 734.3(b)(3) and
172 * 734.7(b).
173 */
174
175 /*
176 * A "png_get_copyright" function is available, for convenient use in "about"
177 * boxes and the like:
178 *
179 * printf("%s", png_get_copyright(NULL));
180 *
181 * Also, the PNG logo (in PNG format, of course) is supplied in the
182 * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
183 */
184
185 /*
186 * The contributing authors would like to thank all those who helped
187 * with testing, bug fixes, and patience. This wouldn't have been
188 * possible without all of you.
189 *
190 * Thanks to Frank J. T. Wojcik for helping with the documentation.
191 */
192
193 /* Note about libpng version numbers:
194 *
195 * Due to various miscommunications, unforeseen code incompatibilities
196 * and occasional factors outside the authors' control, version numbering
197 * on the library has not always been consistent and straightforward.
198 * The following table summarizes matters since version 0.89c, which was
199 * the first widely used release:
200 *
201 * source png.h png.h shared-lib
202 * version string int version
203 * ------- ------ ----- ----------
204 * 0.89c "1.0 beta 3" 0.89 89 1.0.89
205 * 0.90 "1.0 beta 4" 0.90 90 0.90 [should have been 2.0.90]
206 * 0.95 "1.0 beta 5" 0.95 95 0.95 [should have been 2.0.95]
207 * 0.96 "1.0 beta 6" 0.96 96 0.96 [should have been 2.0.96]
208 * 0.97b "1.00.97 beta 7" 1.00.97 97 1.0.1 [should have been 2.0.97]
209 * 0.97c 0.97 97 2.0.97
210 * 0.98 0.98 98 2.0.98
211 * 0.99 0.99 98 2.0.99
212 * 0.99a-m 0.99 99 2.0.99
213 * 1.00 1.00 100 2.1.0 [100 should be 10000]
214 * 1.0.0 (from here on, the 100 2.1.0 [100 should be 10000]
215 * 1.0.1 png.h string is 10001 2.1.0
216 * 1.0.1a-e identical to the 10002 from here on, the shared library
217 * 1.0.2 source version) 10002 is 2.V where V is the source code
218 * 1.0.2a-b 10003 version, except as noted.
219 * 1.0.3 10003
220 * 1.0.3a-d 10004
221 * 1.0.4 10004
222 * 1.0.4a-f 10005
223 * 1.0.5 (+ 2 patches) 10005
224 * 1.0.5a-d 10006
225 * 1.0.5e-r 10100 (not source compatible)
226 * 1.0.5s-v 10006 (not binary compatible)
227 * 1.0.6 (+ 3 patches) 10006 (still binary incompatible)
228 * 1.0.6d-f 10007 (still binary incompatible)
229 * 1.0.6g 10007
230 * 1.0.6h 10007 10.6h (testing xy.z so-numbering)
231 * 1.0.6i 10007 10.6i
232 * 1.0.6j 10007 2.1.0.6j (incompatible with 1.0.0)
233 * 1.0.7beta11-14 DLLNUM 10007 2.1.0.7beta11-14 (binary compatible)
234 * 1.0.7beta15-18 1 10007 2.1.0.7beta15-18 (binary compatible)
235 * 1.0.7rc1-2 1 10007 2.1.0.7rc1-2 (binary compatible)
236 * 1.0.7 1 10007 (still compatible)
237 * ...
238 * 1.0.19 10 10019 10.so.0.19[.0]
239 * ...
240 * 1.2.59 13 10257 12.so.0.59[.0]
241 * ...
242 * 1.5.30 15 10527 15.so.15.30[.0]
243 * ...
244 * 1.6.35 16 10635 16.so.16.35[.0]
245 *
246 * Henceforth the source version will match the shared-library major
247 * and minor numbers; the shared-library major version number will be
248 * used for changes in backward compatibility, as it is intended. The
249 * PNG_LIBPNG_VER macro, which is not used within libpng but is available
250 * for applications, is an unsigned integer of the form xyyzz corresponding
251 * to the source version x.y.z (leading zeros in y and z). Beta versions
252 * were given the previous public release number plus a letter, until
253 * version 1.0.6j; from then on they were given the upcoming public
254 * release number plus "betaNN" or "rcNN".
255 *
256 * Binary incompatibility exists only when applications make direct access
257 * to the info_ptr or png_ptr members through png.h, and the compiled
258 * application is loaded with a different version of the library.
259 *
260 * DLLNUM will change each time there are forward or backward changes
261 * in binary compatibility (e.g., when a new feature is added).
262 *
263 * See libpng.txt or libpng.3 for more information. The PNG specification
264 * is available as a W3C Recommendation and as an ISO Specification,
265 * <https://www.w3.org/TR/2003/REC-PNG-20031110/
266 */
267
268 /*
269 * Y2K compliance in libpng:
270 * =========================
271 *
272 * July 15, 2018
273 *
274 * Since the PNG Development group is an ad-hoc body, we can't make
275 * an official declaration.
276 *
277 * This is your unofficial assurance that libpng from version 0.71 and
278 * upward through 1.6.35 are Y2K compliant. It is my belief that
279 * earlier versions were also Y2K compliant.
280 *
281 * Libpng only has two year fields. One is a 2-byte unsigned integer
282 * that will hold years up to 65535. The other, which is deprecated,
283 * holds the date in text format, and will hold years up to 9999.
284 *
285 * The integer is
286 * "png_uint_16 year" in png_time_struct.
287 *
288 * The string is
289 * "char time_buffer[29]" in png_struct. This is no longer used
290 * in libpng-1.6.x and will be removed from libpng-1.7.0.
291 *
292 * There are seven time-related functions:
293 * png.c: png_convert_to_rfc_1123_buffer() in png.c
294 * (formerly png_convert_to_rfc_1123() prior to libpng-1.5.x and
295 * png_convert_to_rfc_1152() in error prior to libpng-0.98)
296 * png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
297 * png_convert_from_time_t() in pngwrite.c
298 * png_get_tIME() in pngget.c
299 * png_handle_tIME() in pngrutil.c, called in pngread.c
300 * png_set_tIME() in pngset.c
301 * png_write_tIME() in pngwutil.c, called in pngwrite.c
302 *
303 * All handle dates properly in a Y2K environment. The
304 * png_convert_from_time_t() function calls gmtime() to convert from system
305 * clock time, which returns (year - 1900), which we properly convert to
306 * the full 4-digit year. There is a possibility that libpng applications
307 * are not passing 4-digit years into the png_convert_to_rfc_1123_buffer()
308 * function, or that they are incorrectly passing only a 2-digit year
309 * instead of "year - 1900" into the png_convert_from_struct_tm() function,
310 * but this is not under our control. The libpng documentation has always
311 * stated that it works with 4-digit years, and the APIs have been
312 * documented as such.
313 *
314 * The tIME chunk itself is also Y2K compliant. It uses a 2-byte unsigned
315 * integer to hold the year, and can hold years as large as 65535.
316 *
317 * zlib, upon which libpng depends, is also Y2K compliant. It contains
318 * no date-related code.
319 *
320 * Glenn Randers-Pehrson
321 * libpng maintainer
322 * PNG Development Group
323 */
324
325 #ifndef PNG_H
326 #define PNG_H
327
328 /* This is not the place to learn how to use libpng. The file libpng-manual.txt
329 * describes how to use libpng, and the file example.c summarizes it
330 * with some code on which to build. This file is useful for looking
331 * at the actual function definitions and structure components. If that
332 * file has been stripped from your copy of libpng, you can find it at
333 * <http://www.libpng.org/pub/png/libpng-manual.txt>
334 *
335 * If you just need to read a PNG file and don't want to read the documentation
336 * skip to the end of this file and read the section entitled 'simplified API'.
337 */
338
339 /* Version information for png.h - this should match the version in png.c */
340 #define PNG_LIBPNG_VER_STRING "1.6.35"
341 #define PNG_HEADER_VERSION_STRING " libpng version 1.6.35 - July 15, 2018\n"
342
343 #define PNG_LIBPNG_VER_SONUM 16
344 #define PNG_LIBPNG_VER_DLLNUM 16
345
346 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
347 #define PNG_LIBPNG_VER_MAJOR 1
348 #define PNG_LIBPNG_VER_MINOR 6
349 #define PNG_LIBPNG_VER_RELEASE 35
350
351 /* This should match the numeric part of the final component of
352 * PNG_LIBPNG_VER_STRING, omitting any leading zero:
353 */
354
355 #define PNG_LIBPNG_VER_BUILD 02
356
357 /* Release Status */
358 #define PNG_LIBPNG_BUILD_ALPHA 1
359 #define PNG_LIBPNG_BUILD_BETA 2
360 #define PNG_LIBPNG_BUILD_RC 3
361 #define PNG_LIBPNG_BUILD_STABLE 4
362 #define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7
363
364 /* Release-Specific Flags */
365 #define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with
366 PNG_LIBPNG_BUILD_STABLE only */
367 #define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with
368 PNG_LIBPNG_BUILD_SPECIAL */
369 #define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with
370 PNG_LIBPNG_BUILD_PRIVATE */
371
372 #define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_BETA
373
374 /* Careful here. At one time, Guy wanted to use 082, but that would be octal.
375 * We must not include leading zeros.
376 * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only
377 * version 1.0.0 was mis-numbered 100 instead of 10000). From
378 * version 1.0.1 it's xxyyzz, where x=major, y=minor, z=release
379 */
380 #define PNG_LIBPNG_VER 10635 /* 1.6.35 */
381
382 /* Library configuration: these options cannot be changed after
383 * the library has been built.
384 */
385 #ifndef PNGLCONF_H
386 /* If pnglibconf.h is missing, you can
387 * copy scripts/pnglibconf.h.prebuilt to pnglibconf.h
388 */
389 # include "pnglibconf.h"
390 #endif
391
392 #ifndef PNG_VERSION_INFO_ONLY
393 /* Machine specific configuration. */
394 # include "pngconf.h"
395 #endif
396
397 /*
398 * Added at libpng-1.2.8
399 *
400 * Ref MSDN: Private as priority over Special
401 * VS_FF_PRIVATEBUILD File *was not* built using standard release
402 * procedures. If this value is given, the StringFileInfo block must
403 * contain a PrivateBuild string.
404 *
405 * VS_FF_SPECIALBUILD File *was* built by the original company using
406 * standard release procedures but is a variation of the standard
407 * file of the same version number. If this value is given, the
408 * StringFileInfo block must contain a SpecialBuild string.
409 */
410
411 #ifdef PNG_USER_PRIVATEBUILD /* From pnglibconf.h */
412 # define PNG_LIBPNG_BUILD_TYPE \
413 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE)
414 #else
415 # ifdef PNG_LIBPNG_SPECIALBUILD
416 # define PNG_LIBPNG_BUILD_TYPE \
417 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL)
418 # else
419 # define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE)
420 # endif
421 #endif
422
423 #ifndef PNG_VERSION_INFO_ONLY
424
425 /* Inhibit C++ name-mangling for libpng functions but not for system calls. */
426 #ifdef __cplusplus
427 extern "C" {
428 #endif /* __cplusplus */
429
430 /* Version information for C files, stored in png.c. This had better match
431 * the version above.
432 */
433 #define png_libpng_ver png_get_header_ver(NULL)
434
435 /* This file is arranged in several sections:
436 *
437 * 1. [omitted]
438 * 2. Any configuration options that can be specified by for the application
439 * code when it is built. (Build time configuration is in pnglibconf.h)
440 * 3. Type definitions (base types are defined in pngconf.h), structure
441 * definitions.
442 * 4. Exported library functions.
443 * 5. Simplified API.
444 * 6. Implementation options.
445 *
446 * The library source code has additional files (principally pngpriv.h) that
447 * allow configuration of the library.
448 */
449
450 /* Section 1: [omitted] */
451
452 /* Section 2: run time configuration
453 * See pnglibconf.h for build time configuration
454 *
455 * Run time configuration allows the application to choose between
456 * implementations of certain arithmetic APIs. The default is set
457 * at build time and recorded in pnglibconf.h, but it is safe to
458 * override these (and only these) settings. Note that this won't
459 * change what the library does, only application code, and the
460 * settings can (and probably should) be made on a per-file basis
461 * by setting the #defines before including png.h
462 *
463 * Use macros to read integers from PNG data or use the exported
464 * functions?
465 * PNG_USE_READ_MACROS: use the macros (see below) Note that
466 * the macros evaluate their argument multiple times.
467 * PNG_NO_USE_READ_MACROS: call the relevant library function.
468 *
469 * Use the alternative algorithm for compositing alpha samples that
470 * does not use division?
471 * PNG_READ_COMPOSITE_NODIV_SUPPORTED: use the 'no division'
472 * algorithm.
473 * PNG_NO_READ_COMPOSITE_NODIV: use the 'division' algorithm.
474 *
475 * How to handle benign errors if PNG_ALLOW_BENIGN_ERRORS is
476 * false?
477 * PNG_ALLOW_BENIGN_ERRORS: map calls to the benign error
478 * APIs to png_warning.
479 * Otherwise the calls are mapped to png_error.
480 */
481
482 /* Section 3: type definitions, including structures and compile time
483 * constants.
484 * See pngconf.h for base types that vary by machine/system
485 */
486
487 /* This triggers a compiler error in png.c, if png.c and png.h
488 * do not agree upon the version number.
489 */
490 typedef char* png_libpng_version_1_6_35;
491
492 /* Basic control structions. Read libpng-manual.txt or libpng.3 for more info.
493 *
494 * png_struct is the cache of information used while reading or writing a single
495 * PNG file. One of these is always required, although the simplified API
496 * (below) hides the creation and destruction of it.
497 */
498 typedef struct png_struct_def png_struct;
499 typedef const png_struct * png_const_structp;
500 typedef png_struct * png_structp;
501 typedef png_struct * * png_structpp;
502
503 /* png_info contains information read from or to be written to a PNG file. One
504 * or more of these must exist while reading or creating a PNG file. The
505 * information is not used by libpng during read but is used to control what
506 * gets written when a PNG file is created. "png_get_" function calls read
507 * information during read and "png_set_" functions calls write information
508 * when creating a PNG.
509 * been moved into a separate header file that is not accessible to
510 * applications. Read libpng-manual.txt or libpng.3 for more info.
511 */
512 typedef struct png_info_def png_info;
513 typedef png_info * png_infop;
514 typedef const png_info * png_const_infop;
515 typedef png_info * * png_infopp;
516
517 /* Types with names ending 'p' are pointer types. The corresponding types with
518 * names ending 'rp' are identical pointer types except that the pointer is
519 * marked 'restrict', which means that it is the only pointer to the object
520 * passed to the function. Applications should not use the 'restrict' types;
521 * it is always valid to pass 'p' to a pointer with a function argument of the
522 * corresponding 'rp' type. Different compilers have different rules with
523 * regard to type matching in the presence of 'restrict'. For backward
524 * compatibility libpng callbacks never have 'restrict' in their parameters and,
525 * consequentially, writing portable application code is extremely difficult if
526 * an attempt is made to use 'restrict'.
527 */
528 typedef png_struct * PNG_RESTRICT png_structrp;
529 typedef const png_struct * PNG_RESTRICT png_const_structrp;
530 typedef png_info * PNG_RESTRICT png_inforp;
531 typedef const png_info * PNG_RESTRICT png_const_inforp;
532
533 /* Three color definitions. The order of the red, green, and blue, (and the
534 * exact size) is not important, although the size of the fields need to
535 * be png_byte or png_uint_16 (as defined below).
536 */
537 typedef struct png_color_struct
538 {
539 png_byte red;
540 png_byte green;
541 png_byte blue;
542 } png_color;
543 typedef png_color * png_colorp;
544 typedef const png_color * png_const_colorp;
545 typedef png_color * * png_colorpp;
546
547 typedef struct png_color_16_struct
548 {
549 png_byte index; /* used for palette files */
550 png_uint_16 red; /* for use in red green blue files */
551 png_uint_16 green;
552 png_uint_16 blue;
553 png_uint_16 gray; /* for use in grayscale files */
554 } png_color_16;
555 typedef png_color_16 * png_color_16p;
556 typedef const png_color_16 * png_const_color_16p;
557 typedef png_color_16 * * png_color_16pp;
558
559 typedef struct png_color_8_struct
560 {
561 png_byte red; /* for use in red green blue files */
562 png_byte green;
563 png_byte blue;
564 png_byte gray; /* for use in grayscale files */
565 png_byte alpha; /* for alpha channel files */
566 } png_color_8;
567 typedef png_color_8 * png_color_8p;
568 typedef const png_color_8 * png_const_color_8p;
569 typedef png_color_8 * * png_color_8pp;
570
571 /*
572 * The following two structures are used for the in-core representation
573 * of sPLT chunks.
574 */
575 typedef struct png_sPLT_entry_struct
576 {
577 png_uint_16 red;
578 png_uint_16 green;
579 png_uint_16 blue;
580 png_uint_16 alpha;
581 png_uint_16 frequency;
582 } png_sPLT_entry;
583 typedef png_sPLT_entry * png_sPLT_entryp;
584 typedef const png_sPLT_entry * png_const_sPLT_entryp;
585 typedef png_sPLT_entry * * png_sPLT_entrypp;
586
587 /* When the depth of the sPLT palette is 8 bits, the color and alpha samples
588 * occupy the LSB of their respective members, and the MSB of each member
589 * is zero-filled. The frequency member always occupies the full 16 bits.
590 */
591
592 typedef struct png_sPLT_struct
593 {
594 png_charp name; /* palette name */
595 png_byte depth; /* depth of palette samples */
596 png_sPLT_entryp entries; /* palette entries */
597 png_int_32 nentries; /* number of palette entries */
598 } png_sPLT_t;
599 typedef png_sPLT_t * png_sPLT_tp;
600 typedef const png_sPLT_t * png_const_sPLT_tp;
601 typedef png_sPLT_t * * png_sPLT_tpp;
602
603 #ifdef PNG_TEXT_SUPPORTED
604 /* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,
605 * and whether that contents is compressed or not. The "key" field
606 * points to a regular zero-terminated C string. The "text" fields can be a
607 * regular C string, an empty string, or a NULL pointer.
608 * However, the structure returned by png_get_text() will always contain
609 * the "text" field as a regular zero-terminated C string (possibly
610 * empty), never a NULL pointer, so it can be safely used in printf() and
611 * other string-handling functions. Note that the "itxt_length", "lang", and
612 * "lang_key" members of the structure only exist when the library is built
613 * with iTXt chunk support. Prior to libpng-1.4.0 the library was built by
614 * default without iTXt support. Also note that when iTXt *is* supported,
615 * the "lang" and "lang_key" fields contain NULL pointers when the
616 * "compression" field contains * PNG_TEXT_COMPRESSION_NONE or
617 * PNG_TEXT_COMPRESSION_zTXt. Note that the "compression value" is not the
618 * same as what appears in the PNG tEXt/zTXt/iTXt chunk's "compression flag"
619 * which is always 0 or 1, or its "compression method" which is always 0.
620 */
621 typedef struct png_text_struct
622 {
623 int compression; /* compression value:
624 -1: tEXt, none
625 0: zTXt, deflate
626 1: iTXt, none
627 2: iTXt, deflate */
628 png_charp key; /* keyword, 1-79 character description of "text" */
629 png_charp text; /* comment, may be an empty string (ie "")
630 or a NULL pointer */
631 size_t text_length; /* length of the text string */
632 size_t itxt_length; /* length of the itxt string */
633 png_charp lang; /* language code, 0-79 characters
634 or a NULL pointer */
635 png_charp lang_key; /* keyword translated UTF-8 string, 0 or more
636 chars or a NULL pointer */
637 } png_text;
638 typedef png_text * png_textp;
639 typedef const png_text * png_const_textp;
640 typedef png_text * * png_textpp;
641 #endif
642
643 /* Supported compression types for text in PNG files (tEXt, and zTXt).
644 * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */
645 #define PNG_TEXT_COMPRESSION_NONE_WR -3
646 #define PNG_TEXT_COMPRESSION_zTXt_WR -2
647 #define PNG_TEXT_COMPRESSION_NONE -1
648 #define PNG_TEXT_COMPRESSION_zTXt 0
649 #define PNG_ITXT_COMPRESSION_NONE 1
650 #define PNG_ITXT_COMPRESSION_zTXt 2
651 #define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */
652
653 /* png_time is a way to hold the time in an machine independent way.
654 * Two conversions are provided, both from time_t and struct tm. There
655 * is no portable way to convert to either of these structures, as far
656 * as I know. If you know of a portable way, send it to me. As a side
657 * note - PNG has always been Year 2000 compliant!
658 */
659 typedef struct png_time_struct
660 {
661 png_uint_16 year; /* full year, as in, 1995 */
662 png_byte month; /* month of year, 1 - 12 */
663 png_byte day; /* day of month, 1 - 31 */
664 png_byte hour; /* hour of day, 0 - 23 */
665 png_byte minute; /* minute of hour, 0 - 59 */
666 png_byte second; /* second of minute, 0 - 60 (for leap seconds) */
667 } png_time;
668 typedef png_time * png_timep;
669 typedef const png_time * png_const_timep;
670 typedef png_time * * png_timepp;
671
672 #if defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) ||\
673 defined(PNG_USER_CHUNKS_SUPPORTED)
674 /* png_unknown_chunk is a structure to hold queued chunks for which there is
675 * no specific support. The idea is that we can use this to queue
676 * up private chunks for output even though the library doesn't actually
677 * know about their semantics.
678 *
679 * The data in the structure is set by libpng on read and used on write.
680 */
681 typedef struct png_unknown_chunk_t
682 {
683 png_byte name[5]; /* Textual chunk name with '\0' terminator */
684 png_byte *data; /* Data, should not be modified on read! */
685 size_t size;
686
687 /* On write 'location' must be set using the flag values listed below.
688 * Notice that on read it is set by libpng however the values stored have
689 * more bits set than are listed below. Always treat the value as a
690 * bitmask. On write set only one bit - setting multiple bits may cause the
691 * chunk to be written in multiple places.
692 */
693 png_byte location; /* mode of operation at read time */
694 }
695 png_unknown_chunk;
696
697 typedef png_unknown_chunk * png_unknown_chunkp;
698 typedef const png_unknown_chunk * png_const_unknown_chunkp;
699 typedef png_unknown_chunk * * png_unknown_chunkpp;
700 #endif
701
702 /* Flag values for the unknown chunk location byte. */
703 #define PNG_HAVE_IHDR 0x01
704 #define PNG_HAVE_PLTE 0x02
705 #define PNG_AFTER_IDAT 0x08
706
707 /* Maximum positive integer used in PNG is (2^31)-1 */
708 #define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL)
709 #define PNG_UINT_32_MAX ((png_uint_32)(-1))
710 #define PNG_SIZE_MAX ((size_t)(-1))
711
712 /* These are constants for fixed point values encoded in the
713 * PNG specification manner (x100000)
714 */
715 #define PNG_FP_1 100000
716 #define PNG_FP_HALF 50000
717 #define PNG_FP_MAX ((png_fixed_point)0x7fffffffL)
718 #define PNG_FP_MIN (-PNG_FP_MAX)
719
720 /* These describe the color_type field in png_info. */
721 /* color type masks */
722 #define PNG_COLOR_MASK_PALETTE 1
723 #define PNG_COLOR_MASK_COLOR 2
724 #define PNG_COLOR_MASK_ALPHA 4
725
726 /* color types. Note that not all combinations are legal */
727 #define PNG_COLOR_TYPE_GRAY 0
728 #define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
729 #define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR)
730 #define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
731 #define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
732 /* aliases */
733 #define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA
734 #define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA
735
736 /* This is for compression type. PNG 1.0-1.2 only define the single type. */
737 #define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */
738 #define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE
739
740 /* This is for filter type. PNG 1.0-1.2 only define the single type. */
741 #define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */
742 #define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */
743 #define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE
744
745 /* These are for the interlacing type. These values should NOT be changed. */
746 #define PNG_INTERLACE_NONE 0 /* Non-interlaced image */
747 #define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */
748 #define PNG_INTERLACE_LAST 2 /* Not a valid value */
749
750 /* These are for the oFFs chunk. These values should NOT be changed. */
751 #define PNG_OFFSET_PIXEL 0 /* Offset in pixels */
752 #define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */
753 #define PNG_OFFSET_LAST 2 /* Not a valid value */
754
755 /* These are for the pCAL chunk. These values should NOT be changed. */
756 #define PNG_EQUATION_LINEAR 0 /* Linear transformation */
757 #define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */
758 #define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */
759 #define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */
760 #define PNG_EQUATION_LAST 4 /* Not a valid value */
761
762 /* These are for the sCAL chunk. These values should NOT be changed. */
763 #define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */
764 #define PNG_SCALE_METER 1 /* meters per pixel */
765 #define PNG_SCALE_RADIAN 2 /* radians per pixel */
766 #define PNG_SCALE_LAST 3 /* Not a valid value */
767
768 /* These are for the pHYs chunk. These values should NOT be changed. */
769 #define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */
770 #define PNG_RESOLUTION_METER 1 /* pixels/meter */
771 #define PNG_RESOLUTION_LAST 2 /* Not a valid value */
772
773 /* These are for the sRGB chunk. These values should NOT be changed. */
774 #define PNG_sRGB_INTENT_PERCEPTUAL 0
775 #define PNG_sRGB_INTENT_RELATIVE 1
776 #define PNG_sRGB_INTENT_SATURATION 2
777 #define PNG_sRGB_INTENT_ABSOLUTE 3
778 #define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */
779
780 /* This is for text chunks */
781 #define PNG_KEYWORD_MAX_LENGTH 79
782
783 /* Maximum number of entries in PLTE/sPLT/tRNS arrays */
784 #define PNG_MAX_PALETTE_LENGTH 256
785
786 /* These determine if an ancillary chunk's data has been successfully read
787 * from the PNG header, or if the application has filled in the corresponding
788 * data in the info_struct to be written into the output file. The values
789 * of the PNG_INFO_<chunk> defines should NOT be changed.
790 */
791 #define PNG_INFO_gAMA 0x0001U
792 #define PNG_INFO_sBIT 0x0002U
793 #define PNG_INFO_cHRM 0x0004U
794 #define PNG_INFO_PLTE 0x0008U
795 #define PNG_INFO_tRNS 0x0010U
796 #define PNG_INFO_bKGD 0x0020U
797 #define PNG_INFO_hIST 0x0040U
798 #define PNG_INFO_pHYs 0x0080U
799 #define PNG_INFO_oFFs 0x0100U
800 #define PNG_INFO_tIME 0x0200U
801 #define PNG_INFO_pCAL 0x0400U
802 #define PNG_INFO_sRGB 0x0800U /* GR-P, 0.96a */
803 #define PNG_INFO_iCCP 0x1000U /* ESR, 1.0.6 */
804 #define PNG_INFO_sPLT 0x2000U /* ESR, 1.0.6 */
805 #define PNG_INFO_sCAL 0x4000U /* ESR, 1.0.6 */
806 #define PNG_INFO_IDAT 0x8000U /* ESR, 1.0.6 */
807 #define PNG_INFO_eXIf 0x10000U /* GR-P, 1.6.31 */
808
809 /* This is used for the transformation routines, as some of them
810 * change these values for the row. It also should enable using
811 * the routines for other purposes.
812 */
813 typedef struct png_row_info_struct
814 {
815 png_uint_32 width; /* width of row */
816 size_t rowbytes; /* number of bytes in row */
817 png_byte color_type; /* color type of row */
818 png_byte bit_depth; /* bit depth of row */
819 png_byte channels; /* number of channels (1, 2, 3, or 4) */
820 png_byte pixel_depth; /* bits per pixel (depth * channels) */
821 } png_row_info;
822
823 typedef png_row_info * png_row_infop;
824 typedef png_row_info * * png_row_infopp;
825
826 /* These are the function types for the I/O functions and for the functions
827 * that allow the user to override the default I/O functions with his or her
828 * own. The png_error_ptr type should match that of user-supplied warning
829 * and error functions, while the png_rw_ptr type should match that of the
830 * user read/write data functions. Note that the 'write' function must not
831 * modify the buffer it is passed. The 'read' function, on the other hand, is
832 * expected to return the read data in the buffer.
833 */
834 typedef PNG_CALLBACK(void, *png_error_ptr, (png_structp, png_const_charp));
835 typedef PNG_CALLBACK(void, *png_rw_ptr, (png_structp, png_bytep, size_t));
836 typedef PNG_CALLBACK(void, *png_flush_ptr, (png_structp));
837 typedef PNG_CALLBACK(void, *png_read_status_ptr, (png_structp, png_uint_32,
838 int));
839 typedef PNG_CALLBACK(void, *png_write_status_ptr, (png_structp, png_uint_32,
840 int));
841
842 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
843 typedef PNG_CALLBACK(void, *png_progressive_info_ptr, (png_structp, png_infop));
844 typedef PNG_CALLBACK(void, *png_progressive_end_ptr, (png_structp, png_infop));
845
846 /* The following callback receives png_uint_32 row_number, int pass for the
847 * png_bytep data of the row. When transforming an interlaced image the
848 * row number is the row number within the sub-image of the interlace pass, so
849 * the value will increase to the height of the sub-image (not the full image)
850 * then reset to 0 for the next pass.
851 *
852 * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
853 * find the output pixel (x,y) given an interlaced sub-image pixel
854 * (row,col,pass). (See below for these macros.)
855 */
856 typedef PNG_CALLBACK(void, *png_progressive_row_ptr, (png_structp, png_bytep,
857 png_uint_32, int));
858 #endif
859
860 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
861 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
862 typedef PNG_CALLBACK(void, *png_user_transform_ptr, (png_structp, png_row_infop,
863 png_bytep));
864 #endif
865
866 #ifdef PNG_USER_CHUNKS_SUPPORTED
867 typedef PNG_CALLBACK(int, *png_user_chunk_ptr, (png_structp,
868 png_unknown_chunkp));
869 #endif
870 #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
871 /* not used anywhere */
872 /* typedef PNG_CALLBACK(void, *png_unknown_chunk_ptr, (png_structp)); */
873 #endif
874
875 #ifdef PNG_SETJMP_SUPPORTED
876 /* This must match the function definition in <setjmp.h>, and the application
877 * must include this before png.h to obtain the definition of jmp_buf. The
878 * function is required to be PNG_NORETURN, but this is not checked. If the
879 * function does return the application will crash via an abort() or similar
880 * system level call.
881 *
882 * If you get a warning here while building the library you may need to make
883 * changes to ensure that pnglibconf.h records the calling convention used by
884 * your compiler. This may be very difficult - try using a different compiler
885 * to build the library!
886 */
887 PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)), typedef);
888 #endif
889
890 /* Transform masks for the high-level interface */
891 #define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */
892 #define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */
893 #define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */
894 #define PNG_TRANSFORM_PACKING 0x0004 /* read and write */
895 #define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */
896 #define PNG_TRANSFORM_EXPAND 0x0010 /* read only */
897 #define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */
898 #define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */
899 #define PNG_TRANSFORM_BGR 0x0080 /* read and write */
900 #define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */
901 #define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */
902 #define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */
903 #define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* write only */
904 /* Added to libpng-1.2.34 */
905 #define PNG_TRANSFORM_STRIP_FILLER_BEFORE PNG_TRANSFORM_STRIP_FILLER
906 #define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */
907 /* Added to libpng-1.4.0 */
908 #define PNG_TRANSFORM_GRAY_TO_RGB 0x2000 /* read only */
909 /* Added to libpng-1.5.4 */
910 #define PNG_TRANSFORM_EXPAND_16 0x4000 /* read only */
911 #if INT_MAX >= 0x8000 /* else this might break */
912 #define PNG_TRANSFORM_SCALE_16 0x8000 /* read only */
913 #endif
914
915 /* Flags for MNG supported features */
916 #define PNG_FLAG_MNG_EMPTY_PLTE 0x01
917 #define PNG_FLAG_MNG_FILTER_64 0x04
918 #define PNG_ALL_MNG_FEATURES 0x05
919
920 /* NOTE: prior to 1.5 these functions had no 'API' style declaration,
921 * this allowed the zlib default functions to be used on Windows
922 * platforms. In 1.5 the zlib default malloc (which just calls malloc and
923 * ignores the first argument) should be completely compatible with the
924 * following.
925 */
926 typedef PNG_CALLBACK(png_voidp, *png_malloc_ptr, (png_structp,
927 png_alloc_size_t));
928 typedef PNG_CALLBACK(void, *png_free_ptr, (png_structp, png_voidp));
929
930 /* Section 4: exported functions
931 * Here are the function definitions most commonly used. This is not
932 * the place to find out how to use libpng. See libpng-manual.txt for the
933 * full explanation, see example.c for the summary. This just provides
934 * a simple one line description of the use of each function.
935 *
936 * The PNG_EXPORT() and PNG_EXPORTA() macros used below are defined in
937 * pngconf.h and in the *.dfn files in the scripts directory.
938 *
939 * PNG_EXPORT(ordinal, type, name, (args));
940 *
941 * ordinal: ordinal that is used while building
942 * *.def files. The ordinal value is only
943 * relevant when preprocessing png.h with
944 * the *.dfn files for building symbol table
945 * entries, and are removed by pngconf.h.
946 * type: return type of the function
947 * name: function name
948 * args: function arguments, with types
949 *
950 * When we wish to append attributes to a function prototype we use
951 * the PNG_EXPORTA() macro instead.
952 *
953 * PNG_EXPORTA(ordinal, type, name, (args), attributes);
954 *
955 * ordinal, type, name, and args: same as in PNG_EXPORT().
956 * attributes: function attributes
957 */
958
959 /* Returns the version number of the library */
960 PNG_EXPORT(1, png_uint_32, png_access_version_number, (void));
961
962 /* Tell lib we have already handled the first <num_bytes> magic bytes.
963 * Handling more than 8 bytes from the beginning of the file is an error.
964 */
965 PNG_EXPORT(2, void, png_set_sig_bytes, (png_structrp png_ptr, int num_bytes));
966
967 /* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
968 * PNG file. Returns zero if the supplied bytes match the 8-byte PNG
969 * signature, and non-zero otherwise. Having num_to_check == 0 or
970 * start > 7 will always fail (ie return non-zero).
971 */
972 PNG_EXPORT(3, int, png_sig_cmp, (png_const_bytep sig, size_t start,
973 size_t num_to_check));
974
975 /* Simple signature checking function. This is the same as calling
976 * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n).
977 */
978 #define png_check_sig(sig, n) !png_sig_cmp((sig), 0, (n))
979
980 /* Allocate and initialize png_ptr struct for reading, and any other memory. */
981 PNG_EXPORTA(4, png_structp, png_create_read_struct,
982 (png_const_charp user_png_ver, png_voidp error_ptr,
983 png_error_ptr error_fn, png_error_ptr warn_fn),
984 PNG_ALLOCATED);
985
986 /* Allocate and initialize png_ptr struct for writing, and any other memory */
987 PNG_EXPORTA(5, png_structp, png_create_write_struct,
988 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
989 png_error_ptr warn_fn),
990 PNG_ALLOCATED);
991
992 PNG_EXPORT(6, size_t, png_get_compression_buffer_size,
993 (png_const_structrp png_ptr));
994
995 PNG_EXPORT(7, void, png_set_compression_buffer_size, (png_structrp png_ptr,
996 size_t size));
997
998 /* Moved from pngconf.h in 1.4.0 and modified to ensure setjmp/longjmp
999 * match up.
1000 */
1001 #ifdef PNG_SETJMP_SUPPORTED
1002 /* This function returns the jmp_buf built in to *png_ptr. It must be
1003 * supplied with an appropriate 'longjmp' function to use on that jmp_buf
1004 * unless the default error function is overridden in which case NULL is
1005 * acceptable. The size of the jmp_buf is checked against the actual size
1006 * allocated by the library - the call will return NULL on a mismatch
1007 * indicating an ABI mismatch.
1008 */
1009 PNG_EXPORT(8, jmp_buf*, png_set_longjmp_fn, (png_structrp png_ptr,
1010 png_longjmp_ptr longjmp_fn, size_t jmp_buf_size));
1011 # define png_jmpbuf(png_ptr) \
1012 (*png_set_longjmp_fn((png_ptr), longjmp, (sizeof (jmp_buf))))
1013 #else
1014 # define png_jmpbuf(png_ptr) \
1015 (LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP)
1016 #endif
1017 /* This function should be used by libpng applications in place of
1018 * longjmp(png_ptr->jmpbuf, val). If longjmp_fn() has been set, it
1019 * will use it; otherwise it will call PNG_ABORT(). This function was
1020 * added in libpng-1.5.0.
1021 */
1022 PNG_EXPORTA(9, void, png_longjmp, (png_const_structrp png_ptr, int val),
1023 PNG_NORETURN);
1024
1025 #ifdef PNG_READ_SUPPORTED
1026 /* Reset the compression stream */
1027 PNG_EXPORTA(10, int, png_reset_zstream, (png_structrp png_ptr), PNG_DEPRECATED);
1028 #endif
1029
1030 /* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */
1031 #ifdef PNG_USER_MEM_SUPPORTED
1032 PNG_EXPORTA(11, png_structp, png_create_read_struct_2,
1033 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
1034 png_error_ptr warn_fn,
1035 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn),
1036 PNG_ALLOCATED);
1037 PNG_EXPORTA(12, png_structp, png_create_write_struct_2,
1038 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
1039 png_error_ptr warn_fn,
1040 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn),
1041 PNG_ALLOCATED);
1042 #endif
1043
1044 /* Write the PNG file signature. */
1045 PNG_EXPORT(13, void, png_write_sig, (png_structrp png_ptr));
1046
1047 /* Write a PNG chunk - size, type, (optional) data, CRC. */
1048 PNG_EXPORT(14, void, png_write_chunk, (png_structrp png_ptr, png_const_bytep
1049 chunk_name, png_const_bytep data, size_t length));
1050
1051 /* Write the start of a PNG chunk - length and chunk name. */
1052 PNG_EXPORT(15, void, png_write_chunk_start, (png_structrp png_ptr,
1053 png_const_bytep chunk_name, png_uint_32 length));
1054
1055 /* Write the data of a PNG chunk started with png_write_chunk_start(). */
1056 PNG_EXPORT(16, void, png_write_chunk_data, (png_structrp png_ptr,
1057 png_const_bytep data, size_t length));
1058
1059 /* Finish a chunk started with png_write_chunk_start() (includes CRC). */
1060 PNG_EXPORT(17, void, png_write_chunk_end, (png_structrp png_ptr));
1061
1062 /* Allocate and initialize the info structure */
1063 PNG_EXPORTA(18, png_infop, png_create_info_struct, (png_const_structrp png_ptr),
1064 PNG_ALLOCATED);
1065
1066 /* DEPRECATED: this function allowed init structures to be created using the
1067 * default allocation method (typically malloc). Use is deprecated in 1.6.0 and
1068 * the API will be removed in the future.
1069 */
1070 PNG_EXPORTA(19, void, png_info_init_3, (png_infopp info_ptr,
1071 size_t png_info_struct_size), PNG_DEPRECATED);
1072
1073 /* Writes all the PNG information before the image. */
1074 PNG_EXPORT(20, void, png_write_info_before_PLTE,
1075 (png_structrp png_ptr, png_const_inforp info_ptr));
1076 PNG_EXPORT(21, void, png_write_info,
1077 (png_structrp png_ptr, png_const_inforp info_ptr));
1078
1079 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1080 /* Read the information before the actual image data. */
1081 PNG_EXPORT(22, void, png_read_info,
1082 (png_structrp png_ptr, png_inforp info_ptr));
1083 #endif
1084
1085 #ifdef PNG_TIME_RFC1123_SUPPORTED
1086 /* Convert to a US string format: there is no localization support in this
1087 * routine. The original implementation used a 29 character buffer in
1088 * png_struct, this will be removed in future versions.
1089 */
1090 #if PNG_LIBPNG_VER < 10700
1091 /* To do: remove this from libpng17 (and from libpng17/png.c and pngstruct.h) */
1092 PNG_EXPORTA(23, png_const_charp, png_convert_to_rfc1123, (png_structrp png_ptr,
1093 png_const_timep ptime),PNG_DEPRECATED);
1094 #endif
1095 PNG_EXPORT(241, int, png_convert_to_rfc1123_buffer, (char out[29],
1096 png_const_timep ptime));
1097 #endif
1098
1099 #ifdef PNG_CONVERT_tIME_SUPPORTED
1100 /* Convert from a struct tm to png_time */
1101 PNG_EXPORT(24, void, png_convert_from_struct_tm, (png_timep ptime,
1102 const struct tm * ttime));
1103
1104 /* Convert from time_t to png_time. Uses gmtime() */
1105 PNG_EXPORT(25, void, png_convert_from_time_t, (png_timep ptime, time_t ttime));
1106 #endif /* CONVERT_tIME */
1107
1108 #ifdef PNG_READ_EXPAND_SUPPORTED
1109 /* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
1110 PNG_EXPORT(26, void, png_set_expand, (png_structrp png_ptr));
1111 PNG_EXPORT(27, void, png_set_expand_gray_1_2_4_to_8, (png_structrp png_ptr));
1112 PNG_EXPORT(28, void, png_set_palette_to_rgb, (png_structrp png_ptr));
1113 PNG_EXPORT(29, void, png_set_tRNS_to_alpha, (png_structrp png_ptr));
1114 #endif
1115
1116 #ifdef PNG_READ_EXPAND_16_SUPPORTED
1117 /* Expand to 16-bit channels, forces conversion of palette to RGB and expansion
1118 * of a tRNS chunk if present.
1119 */
1120 PNG_EXPORT(221, void, png_set_expand_16, (png_structrp png_ptr));
1121 #endif
1122
1123 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
1124 /* Use blue, green, red order for pixels. */
1125 PNG_EXPORT(30, void, png_set_bgr, (png_structrp png_ptr));
1126 #endif
1127
1128 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
1129 /* Expand the grayscale to 24-bit RGB if necessary. */
1130 PNG_EXPORT(31, void, png_set_gray_to_rgb, (png_structrp png_ptr));
1131 #endif
1132
1133 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1134 /* Reduce RGB to grayscale. */
1135 #define PNG_ERROR_ACTION_NONE 1
1136 #define PNG_ERROR_ACTION_WARN 2
1137 #define PNG_ERROR_ACTION_ERROR 3
1138 #define PNG_RGB_TO_GRAY_DEFAULT (-1)/*for red/green coefficients*/
1139
1140 PNG_FP_EXPORT(32, void, png_set_rgb_to_gray, (png_structrp png_ptr,
1141 int error_action, double red, double green))
1142 PNG_FIXED_EXPORT(33, void, png_set_rgb_to_gray_fixed, (png_structrp png_ptr,
1143 int error_action, png_fixed_point red, png_fixed_point green))
1144
1145 PNG_EXPORT(34, png_byte, png_get_rgb_to_gray_status, (png_const_structrp
1146 png_ptr));
1147 #endif
1148
1149 #ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED
1150 PNG_EXPORT(35, void, png_build_grayscale_palette, (int bit_depth,
1151 png_colorp palette));
1152 #endif
1153
1154 #ifdef PNG_READ_ALPHA_MODE_SUPPORTED
1155 /* How the alpha channel is interpreted - this affects how the color channels
1156 * of a PNG file are returned to the calling application when an alpha channel,
1157 * or a tRNS chunk in a palette file, is present.
1158 *
1159 * This has no effect on the way pixels are written into a PNG output
1160 * datastream. The color samples in a PNG datastream are never premultiplied
1161 * with the alpha samples.
1162 *
1163 * The default is to return data according to the PNG specification: the alpha
1164 * channel is a linear measure of the contribution of the pixel to the
1165 * corresponding composited pixel, and the color channels are unassociated
1166 * (not premultiplied). The gamma encoded color channels must be scaled
1167 * according to the contribution and to do this it is necessary to undo
1168 * the encoding, scale the color values, perform the composition and re-encode
1169 * the values. This is the 'PNG' mode.
1170 *
1171 * The alternative is to 'associate' the alpha with the color information by
1172 * storing color channel values that have been scaled by the alpha.
1173 * image. These are the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' modes
1174 * (the latter being the two common names for associated alpha color channels).
1175 *
1176 * For the 'OPTIMIZED' mode, a pixel is treated as opaque only if the alpha
1177 * value is equal to the maximum value.
1178 *
1179 * The final choice is to gamma encode the alpha channel as well. This is
1180 * broken because, in practice, no implementation that uses this choice
1181 * correctly undoes the encoding before handling alpha composition. Use this
1182 * choice only if other serious errors in the software or hardware you use
1183 * mandate it; the typical serious error is for dark halos to appear around
1184 * opaque areas of the composited PNG image because of arithmetic overflow.
1185 *
1186 * The API function png_set_alpha_mode specifies which of these choices to use
1187 * with an enumerated 'mode' value and the gamma of the required output:
1188 */
1189 #define PNG_ALPHA_PNG 0 /* according to the PNG standard */
1190 #define PNG_ALPHA_STANDARD 1 /* according to Porter/Duff */
1191 #define PNG_ALPHA_ASSOCIATED 1 /* as above; this is the normal practice */
1192 #define PNG_ALPHA_PREMULTIPLIED 1 /* as above */
1193 #define PNG_ALPHA_OPTIMIZED 2 /* 'PNG' for opaque pixels, else 'STANDARD' */
1194 #define PNG_ALPHA_BROKEN 3 /* the alpha channel is gamma encoded */
1195
1196 PNG_FP_EXPORT(227, void, png_set_alpha_mode, (png_structrp png_ptr, int mode,
1197 double output_gamma))
1198 PNG_FIXED_EXPORT(228, void, png_set_alpha_mode_fixed, (png_structrp png_ptr,
1199 int mode, png_fixed_point output_gamma))
1200 #endif
1201
1202 #if defined(PNG_GAMMA_SUPPORTED) || defined(PNG_READ_ALPHA_MODE_SUPPORTED)
1203 /* The output_gamma value is a screen gamma in libpng terminology: it expresses
1204 * how to decode the output values, not how they are encoded.
1205 */
1206 #define PNG_DEFAULT_sRGB -1 /* sRGB gamma and color space */
1207 #define PNG_GAMMA_MAC_18 -2 /* Old Mac '1.8' gamma and color space */
1208 #define PNG_GAMMA_sRGB 220000 /* Television standards--matches sRGB gamma */
1209 #define PNG_GAMMA_LINEAR PNG_FP_1 /* Linear */
1210 #endif
1211
1212 /* The following are examples of calls to png_set_alpha_mode to achieve the
1213 * required overall gamma correction and, where necessary, alpha
1214 * premultiplication.
1215 *
1216 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
1217 * This is the default libpng handling of the alpha channel - it is not
1218 * pre-multiplied into the color components. In addition the call states
1219 * that the output is for a sRGB system and causes all PNG files without gAMA
1220 * chunks to be assumed to be encoded using sRGB.
1221 *
1222 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
1223 * In this case the output is assumed to be something like an sRGB conformant
1224 * display preceded by a power-law lookup table of power 1.45. This is how
1225 * early Mac systems behaved.
1226 *
1227 * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR);
1228 * This is the classic Jim Blinn approach and will work in academic
1229 * environments where everything is done by the book. It has the shortcoming
1230 * of assuming that input PNG data with no gamma information is linear - this
1231 * is unlikely to be correct unless the PNG files where generated locally.
1232 * Most of the time the output precision will be so low as to show
1233 * significant banding in dark areas of the image.
1234 *
1235 * png_set_expand_16(pp);
1236 * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB);
1237 * This is a somewhat more realistic Jim Blinn inspired approach. PNG files
1238 * are assumed to have the sRGB encoding if not marked with a gamma value and
1239 * the output is always 16 bits per component. This permits accurate scaling
1240 * and processing of the data. If you know that your input PNG files were
1241 * generated locally you might need to replace PNG_DEFAULT_sRGB with the
1242 * correct value for your system.
1243 *
1244 * png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB);
1245 * If you just need to composite the PNG image onto an existing background
1246 * and if you control the code that does this you can use the optimization
1247 * setting. In this case you just copy completely opaque pixels to the
1248 * output. For pixels that are not completely transparent (you just skip
1249 * those) you do the composition math using png_composite or png_composite_16
1250 * below then encode the resultant 8-bit or 16-bit values to match the output
1251 * encoding.
1252 *
1253 * Other cases
1254 * If neither the PNG nor the standard linear encoding work for you because
1255 * of the software or hardware you use then you have a big problem. The PNG
1256 * case will probably result in halos around the image. The linear encoding
1257 * will probably result in a washed out, too bright, image (it's actually too
1258 * contrasty.) Try the ALPHA_OPTIMIZED mode above - this will probably
1259 * substantially reduce the halos. Alternatively try:
1260 *
1261 * png_set_alpha_mode(pp, PNG_ALPHA_BROKEN, PNG_DEFAULT_sRGB);
1262 * This option will also reduce the halos, but there will be slight dark
1263 * halos round the opaque parts of the image where the background is light.
1264 * In the OPTIMIZED mode the halos will be light halos where the background
1265 * is dark. Take your pick - the halos are unavoidable unless you can get
1266 * your hardware/software fixed! (The OPTIMIZED approach is slightly
1267 * faster.)
1268 *
1269 * When the default gamma of PNG files doesn't match the output gamma.
1270 * If you have PNG files with no gamma information png_set_alpha_mode allows
1271 * you to provide a default gamma, but it also sets the output gamma to the
1272 * matching value. If you know your PNG files have a gamma that doesn't
1273 * match the output you can take advantage of the fact that
1274 * png_set_alpha_mode always sets the output gamma but only sets the PNG
1275 * default if it is not already set:
1276 *
1277 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
1278 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
1279 * The first call sets both the default and the output gamma values, the
1280 * second call overrides the output gamma without changing the default. This
1281 * is easier than achieving the same effect with png_set_gamma. You must use
1282 * PNG_ALPHA_PNG for the first call - internal checking in png_set_alpha will
1283 * fire if more than one call to png_set_alpha_mode and png_set_background is
1284 * made in the same read operation, however multiple calls with PNG_ALPHA_PNG
1285 * are ignored.
1286 */
1287
1288 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
1289 PNG_EXPORT(36, void, png_set_strip_alpha, (png_structrp png_ptr));
1290 #endif
1291
1292 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
1293 defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
1294 PNG_EXPORT(37, void, png_set_swap_alpha, (png_structrp png_ptr));
1295 #endif
1296
1297 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
1298 defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
1299 PNG_EXPORT(38, void, png_set_invert_alpha, (png_structrp png_ptr));
1300 #endif
1301
1302 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
1303 /* Add a filler byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */
1304 PNG_EXPORT(39, void, png_set_filler, (png_structrp png_ptr, png_uint_32 filler,
1305 int flags));
1306 /* The values of the PNG_FILLER_ defines should NOT be changed */
1307 # define PNG_FILLER_BEFORE 0
1308 # define PNG_FILLER_AFTER 1
1309 /* Add an alpha byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */
1310 PNG_EXPORT(40, void, png_set_add_alpha, (png_structrp png_ptr,
1311 png_uint_32 filler, int flags));
1312 #endif /* READ_FILLER || WRITE_FILLER */
1313
1314 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
1315 /* Swap bytes in 16-bit depth files. */
1316 PNG_EXPORT(41, void, png_set_swap, (png_structrp png_ptr));
1317 #endif
1318
1319 #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
1320 /* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
1321 PNG_EXPORT(42, void, png_set_packing, (png_structrp png_ptr));
1322 #endif
1323
1324 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
1325 defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1326 /* Swap packing order of pixels in bytes. */
1327 PNG_EXPORT(43, void, png_set_packswap, (png_structrp png_ptr));
1328 #endif
1329
1330 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
1331 /* Converts files to legal bit depths. */
1332 PNG_EXPORT(44, void, png_set_shift, (png_structrp png_ptr, png_const_color_8p
1333 true_bits));
1334 #endif
1335
1336 #if defined(PNG_READ_INTERLACING_SUPPORTED) || \
1337 defined(PNG_WRITE_INTERLACING_SUPPORTED)
1338 /* Have the code handle the interlacing. Returns the number of passes.
1339 * MUST be called before png_read_update_info or png_start_read_image,
1340 * otherwise it will not have the desired effect. Note that it is still
1341 * necessary to call png_read_row or png_read_rows png_get_image_height
1342 * times for each pass.
1343 */
1344 PNG_EXPORT(45, int, png_set_interlace_handling, (png_structrp png_ptr));
1345 #endif
1346
1347 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
1348 /* Invert monochrome files */
1349 PNG_EXPORT(46, void, png_set_invert_mono, (png_structrp png_ptr));
1350 #endif
1351
1352 #ifdef PNG_READ_BACKGROUND_SUPPORTED
1353 /* Handle alpha and tRNS by replacing with a background color. Prior to
1354 * libpng-1.5.4 this API must not be called before the PNG file header has been
1355 * read. Doing so will result in unexpected behavior and possible warnings or
1356 * errors if the PNG file contains a bKGD chunk.
1357 */
1358 PNG_FP_EXPORT(47, void, png_set_background, (png_structrp png_ptr,
1359 png_const_color_16p background_color, int background_gamma_code,
1360 int need_expand, double background_gamma))
1361 PNG_FIXED_EXPORT(215, void, png_set_background_fixed, (png_structrp png_ptr,
1362 png_const_color_16p background_color, int background_gamma_code,
1363 int need_expand, png_fixed_point background_gamma))
1364 #endif
1365 #ifdef PNG_READ_BACKGROUND_SUPPORTED
1366 # define PNG_BACKGROUND_GAMMA_UNKNOWN 0
1367 # define PNG_BACKGROUND_GAMMA_SCREEN 1
1368 # define PNG_BACKGROUND_GAMMA_FILE 2
1369 # define PNG_BACKGROUND_GAMMA_UNIQUE 3
1370 #endif
1371
1372 #ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
1373 /* Scale a 16-bit depth file down to 8-bit, accurately. */
1374 PNG_EXPORT(229, void, png_set_scale_16, (png_structrp png_ptr));
1375 #endif
1376
1377 #ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
1378 #define PNG_READ_16_TO_8_SUPPORTED /* Name prior to 1.5.4 */
1379 /* Strip the second byte of information from a 16-bit depth file. */
1380 PNG_EXPORT(48, void, png_set_strip_16, (png_structrp png_ptr));
1381 #endif
1382
1383 #ifdef PNG_READ_QUANTIZE_SUPPORTED
1384 /* Turn on quantizing, and reduce the palette to the number of colors
1385 * available.
1386 */
1387 PNG_EXPORT(49, void, png_set_quantize, (png_structrp png_ptr,
1388 png_colorp palette, int num_palette, int maximum_colors,
1389 png_const_uint_16p histogram, int full_quantize));
1390 #endif
1391
1392 #ifdef PNG_READ_GAMMA_SUPPORTED
1393 /* The threshold on gamma processing is configurable but hard-wired into the
1394 * library. The following is the floating point variant.
1395 */
1396 #define PNG_GAMMA_THRESHOLD (PNG_GAMMA_THRESHOLD_FIXED*.00001)
1397
1398 /* Handle gamma correction. Screen_gamma=(display_exponent).
1399 * NOTE: this API simply sets the screen and file gamma values. It will
1400 * therefore override the value for gamma in a PNG file if it is called after
1401 * the file header has been read - use with care - call before reading the PNG
1402 * file for best results!
1403 *
1404 * These routines accept the same gamma values as png_set_alpha_mode (described
1405 * above). The PNG_GAMMA_ defines and PNG_DEFAULT_sRGB can be passed to either
1406 * API (floating point or fixed.) Notice, however, that the 'file_gamma' value
1407 * is the inverse of a 'screen gamma' value.
1408 */
1409 PNG_FP_EXPORT(50, void, png_set_gamma, (png_structrp png_ptr,
1410 double screen_gamma, double override_file_gamma))
1411 PNG_FIXED_EXPORT(208, void, png_set_gamma_fixed, (png_structrp png_ptr,
1412 png_fixed_point screen_gamma, png_fixed_point override_file_gamma))
1413 #endif
1414
1415 #ifdef PNG_WRITE_FLUSH_SUPPORTED
1416 /* Set how many lines between output flushes - 0 for no flushing */
1417 PNG_EXPORT(51, void, png_set_flush, (png_structrp png_ptr, int nrows));
1418 /* Flush the current PNG output buffer */
1419 PNG_EXPORT(52, void, png_write_flush, (png_structrp png_ptr));
1420 #endif
1421
1422 /* Optional update palette with requested transformations */
1423 PNG_EXPORT(53, void, png_start_read_image, (png_structrp png_ptr));
1424
1425 /* Optional call to update the users info structure */
1426 PNG_EXPORT(54, void, png_read_update_info, (png_structrp png_ptr,
1427 png_inforp info_ptr));
1428
1429 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1430 /* Read one or more rows of image data. */
1431 PNG_EXPORT(55, void, png_read_rows, (png_structrp png_ptr, png_bytepp row,
1432 png_bytepp display_row, png_uint_32 num_rows));
1433 #endif
1434
1435 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1436 /* Read a row of data. */
1437 PNG_EXPORT(56, void, png_read_row, (png_structrp png_ptr, png_bytep row,
1438 png_bytep display_row));
1439 #endif
1440
1441 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1442 /* Read the whole image into memory at once. */
1443 PNG_EXPORT(57, void, png_read_image, (png_structrp png_ptr, png_bytepp image));
1444 #endif
1445
1446 /* Write a row of image data */
1447 PNG_EXPORT(58, void, png_write_row, (png_structrp png_ptr,
1448 png_const_bytep row));
1449
1450 /* Write a few rows of image data: (*row) is not written; however, the type
1451 * is declared as writeable to maintain compatibility with previous versions
1452 * of libpng and to allow the 'display_row' array from read_rows to be passed
1453 * unchanged to write_rows.
1454 */
1455 PNG_EXPORT(59, void, png_write_rows, (png_structrp png_ptr, png_bytepp row,
1456 png_uint_32 num_rows));
1457
1458 /* Write the image data */
1459 PNG_EXPORT(60, void, png_write_image, (png_structrp png_ptr, png_bytepp image));
1460
1461 /* Write the end of the PNG file. */
1462 PNG_EXPORT(61, void, png_write_end, (png_structrp png_ptr,
1463 png_inforp info_ptr));
1464
1465 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1466 /* Read the end of the PNG file. */
1467 PNG_EXPORT(62, void, png_read_end, (png_structrp png_ptr, png_inforp info_ptr));
1468 #endif
1469
1470 /* Free any memory associated with the png_info_struct */
1471 PNG_EXPORT(63, void, png_destroy_info_struct, (png_const_structrp png_ptr,
1472 png_infopp info_ptr_ptr));
1473
1474 /* Free any memory associated with the png_struct and the png_info_structs */
1475 PNG_EXPORT(64, void, png_destroy_read_struct, (png_structpp png_ptr_ptr,
1476 png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr));
1477
1478 /* Free any memory associated with the png_struct and the png_info_structs */
1479 PNG_EXPORT(65, void, png_destroy_write_struct, (png_structpp png_ptr_ptr,
1480 png_infopp info_ptr_ptr));
1481
1482 /* Set the libpng method of handling chunk CRC errors */
1483 PNG_EXPORT(66, void, png_set_crc_action, (png_structrp png_ptr, int crit_action,
1484 int ancil_action));
1485
1486 /* Values for png_set_crc_action() say how to handle CRC errors in
1487 * ancillary and critical chunks, and whether to use the data contained
1488 * therein. Note that it is impossible to "discard" data in a critical
1489 * chunk. For versions prior to 0.90, the action was always error/quit,
1490 * whereas in version 0.90 and later, the action for CRC errors in ancillary
1491 * chunks is warn/discard. These values should NOT be changed.
1492 *
1493 * value action:critical action:ancillary
1494 */
1495 #define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */
1496 #define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */
1497 #define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */
1498 #define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */
1499 #define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */
1500 #define PNG_CRC_NO_CHANGE 5 /* use current value use current value */
1501
1502 #ifdef PNG_WRITE_SUPPORTED
1503 /* These functions give the user control over the scan-line filtering in
1504 * libpng and the compression methods used by zlib. These functions are
1505 * mainly useful for testing, as the defaults should work with most users.
1506 * Those users who are tight on memory or want faster performance at the
1507 * expense of compression can modify them. See the compression library
1508 * header file (zlib.h) for an explination of the compression functions.
1509 */
1510
1511 /* Set the filtering method(s) used by libpng. Currently, the only valid
1512 * value for "method" is 0.
1513 */
1514 PNG_EXPORT(67, void, png_set_filter, (png_structrp png_ptr, int method,
1515 int filters));
1516 #endif /* WRITE */
1517
1518 /* Flags for png_set_filter() to say which filters to use. The flags
1519 * are chosen so that they don't conflict with real filter types
1520 * below, in case they are supplied instead of the #defined constants.
1521 * These values should NOT be changed.
1522 */
1523 #define PNG_NO_FILTERS 0x00
1524 #define PNG_FILTER_NONE 0x08
1525 #define PNG_FILTER_SUB 0x10
1526 #define PNG_FILTER_UP 0x20
1527 #define PNG_FILTER_AVG 0x40
1528 #define PNG_FILTER_PAETH 0x80
1529 #define PNG_FAST_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP)
1530 #define PNG_ALL_FILTERS (PNG_FAST_FILTERS | PNG_FILTER_AVG | PNG_FILTER_PAETH)
1531
1532 /* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
1533 * These defines should NOT be changed.
1534 */
1535 #define PNG_FILTER_VALUE_NONE 0
1536 #define PNG_FILTER_VALUE_SUB 1
1537 #define PNG_FILTER_VALUE_UP 2
1538 #define PNG_FILTER_VALUE_AVG 3
1539 #define PNG_FILTER_VALUE_PAETH 4
1540 #define PNG_FILTER_VALUE_LAST 5
1541
1542 #ifdef PNG_WRITE_SUPPORTED
1543 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* DEPRECATED */
1544 PNG_FP_EXPORT(68, void, png_set_filter_heuristics, (png_structrp png_ptr,
1545 int heuristic_method, int num_weights, png_const_doublep filter_weights,
1546 png_const_doublep filter_costs))
1547 PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed,
1548 (png_structrp png_ptr, int heuristic_method, int num_weights,
1549 png_const_fixed_point_p filter_weights,
1550 png_const_fixed_point_p filter_costs))
1551 #endif /* WRITE_WEIGHTED_FILTER */
1552
1553 /* The following are no longer used and will be removed from libpng-1.7: */
1554 #define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */
1555 #define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */
1556 #define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */
1557 #define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */
1558
1559 /* Set the library compression level. Currently, valid values range from
1560 * 0 - 9, corresponding directly to the zlib compression levels 0 - 9
1561 * (0 - no compression, 9 - "maximal" compression). Note that tests have
1562 * shown that zlib compression levels 3-6 usually perform as well as level 9
1563 * for PNG images, and do considerably fewer caclulations. In the future,
1564 * these values may not correspond directly to the zlib compression levels.
1565 */
1566 #ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED
1567 PNG_EXPORT(69, void, png_set_compression_level, (png_structrp png_ptr,
1568 int level));
1569
1570 PNG_EXPORT(70, void, png_set_compression_mem_level, (png_structrp png_ptr,
1571 int mem_level));
1572
1573 PNG_EXPORT(71, void, png_set_compression_strategy, (png_structrp png_ptr,
1574 int strategy));
1575
1576 /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
1577 * smaller value of window_bits if it can do so safely.
1578 */
1579 PNG_EXPORT(72, void, png_set_compression_window_bits, (png_structrp png_ptr,
1580 int window_bits));
1581
1582 PNG_EXPORT(73, void, png_set_compression_method, (png_structrp png_ptr,
1583 int method));
1584 #endif /* WRITE_CUSTOMIZE_COMPRESSION */
1585
1586 #ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
1587 /* Also set zlib parameters for compressing non-IDAT chunks */
1588 PNG_EXPORT(222, void, png_set_text_compression_level, (png_structrp png_ptr,
1589 int level));
1590
1591 PNG_EXPORT(223, void, png_set_text_compression_mem_level, (png_structrp png_ptr,
1592 int mem_level));
1593
1594 PNG_EXPORT(224, void, png_set_text_compression_strategy, (png_structrp png_ptr,
1595 int strategy));
1596
1597 /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
1598 * smaller value of window_bits if it can do so safely.
1599 */
1600 PNG_EXPORT(225, void, png_set_text_compression_window_bits,
1601 (png_structrp png_ptr, int window_bits));
1602
1603 PNG_EXPORT(226, void, png_set_text_compression_method, (png_structrp png_ptr,
1604 int method));
1605 #endif /* WRITE_CUSTOMIZE_ZTXT_COMPRESSION */
1606 #endif /* WRITE */
1607
1608 /* These next functions are called for input/output, memory, and error
1609 * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c,
1610 * and call standard C I/O routines such as fread(), fwrite(), and
1611 * fprintf(). These functions can be made to use other I/O routines
1612 * at run time for those applications that need to handle I/O in a
1613 * different manner by calling png_set_???_fn(). See libpng-manual.txt for
1614 * more information.
1615 */
1616
1617 #ifdef PNG_STDIO_SUPPORTED
1618 /* Initialize the input/output for the PNG file to the default functions. */
1619 PNG_EXPORT(74, void, png_init_io, (png_structrp png_ptr, png_FILE_p fp));
1620 #endif
1621
1622 /* Replace the (error and abort), and warning functions with user
1623 * supplied functions. If no messages are to be printed you must still
1624 * write and use replacement functions. The replacement error_fn should
1625 * still do a longjmp to the last setjmp location if you are using this
1626 * method of error handling. If error_fn or warning_fn is NULL, the
1627 * default function will be used.
1628 */
1629
1630 PNG_EXPORT(75, void, png_set_error_fn, (png_structrp png_ptr,
1631 png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn));
1632
1633 /* Return the user pointer associated with the error functions */
1634 PNG_EXPORT(76, png_voidp, png_get_error_ptr, (png_const_structrp png_ptr));
1635
1636 /* Replace the default data output functions with a user supplied one(s).
1637 * If buffered output is not used, then output_flush_fn can be set to NULL.
1638 * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time
1639 * output_flush_fn will be ignored (and thus can be NULL).
1640 * It is probably a mistake to use NULL for output_flush_fn if
1641 * write_data_fn is not also NULL unless you have built libpng with
1642 * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's
1643 * default flush function, which uses the standard *FILE structure, will
1644 * be used.
1645 */
1646 PNG_EXPORT(77, void, png_set_write_fn, (png_structrp png_ptr, png_voidp io_ptr,
1647 png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn));
1648
1649 /* Replace the default data input function with a user supplied one. */
1650 PNG_EXPORT(78, void, png_set_read_fn, (png_structrp png_ptr, png_voidp io_ptr,
1651 png_rw_ptr read_data_fn));
1652
1653 /* Return the user pointer associated with the I/O functions */
1654 PNG_EXPORT(79, png_voidp, png_get_io_ptr, (png_const_structrp png_ptr));
1655
1656 PNG_EXPORT(80, void, png_set_read_status_fn, (png_structrp png_ptr,
1657 png_read_status_ptr read_row_fn));
1658
1659 PNG_EXPORT(81, void, png_set_write_status_fn, (png_structrp png_ptr,
1660 png_write_status_ptr write_row_fn));
1661
1662 #ifdef PNG_USER_MEM_SUPPORTED
1663 /* Replace the default memory allocation functions with user supplied one(s). */
1664 PNG_EXPORT(82, void, png_set_mem_fn, (png_structrp png_ptr, png_voidp mem_ptr,
1665 png_malloc_ptr malloc_fn, png_free_ptr free_fn));
1666 /* Return the user pointer associated with the memory functions */
1667 PNG_EXPORT(83, png_voidp, png_get_mem_ptr, (png_const_structrp png_ptr));
1668 #endif
1669
1670 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
1671 PNG_EXPORT(84, void, png_set_read_user_transform_fn, (png_structrp png_ptr,
1672 png_user_transform_ptr read_user_transform_fn));
1673 #endif
1674
1675 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
1676 PNG_EXPORT(85, void, png_set_write_user_transform_fn, (png_structrp png_ptr,
1677 png_user_transform_ptr write_user_transform_fn));
1678 #endif
1679
1680 #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
1681 PNG_EXPORT(86, void, png_set_user_transform_info, (png_structrp png_ptr,
1682 png_voidp user_transform_ptr, int user_transform_depth,
1683 int user_transform_channels));
1684 /* Return the user pointer associated with the user transform functions */
1685 PNG_EXPORT(87, png_voidp, png_get_user_transform_ptr,
1686 (png_const_structrp png_ptr));
1687 #endif
1688
1689 #ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED
1690 /* Return information about the row currently being processed. Note that these
1691 * APIs do not fail but will return unexpected results if called outside a user
1692 * transform callback. Also note that when transforming an interlaced image the
1693 * row number is the row number within the sub-image of the interlace pass, so
1694 * the value will increase to the height of the sub-image (not the full image)
1695 * then reset to 0 for the next pass.
1696 *
1697 * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
1698 * find the output pixel (x,y) given an interlaced sub-image pixel
1699 * (row,col,pass). (See below for these macros.)
1700 */
1701 PNG_EXPORT(217, png_uint_32, png_get_current_row_number, (png_const_structrp));
1702 PNG_EXPORT(218, png_byte, png_get_current_pass_number, (png_const_structrp));
1703 #endif
1704
1705 #ifdef PNG_READ_USER_CHUNKS_SUPPORTED
1706 /* This callback is called only for *unknown* chunks. If
1707 * PNG_HANDLE_AS_UNKNOWN_SUPPORTED is set then it is possible to set known
1708 * chunks to be treated as unknown, however in this case the callback must do
1709 * any processing required by the chunk (e.g. by calling the appropriate
1710 * png_set_ APIs.)
1711 *
1712 * There is no write support - on write, by default, all the chunks in the
1713 * 'unknown' list are written in the specified position.
1714 *
1715 * The integer return from the callback function is interpreted thus:
1716 *
1717 * negative: An error occurred; png_chunk_error will be called.
1718 * zero: The chunk was not handled, the chunk will be saved. A critical
1719 * chunk will cause an error at this point unless it is to be saved.
1720 * positive: The chunk was handled, libpng will ignore/discard it.
1721 *
1722 * See "INTERACTION WITH USER CHUNK CALLBACKS" below for important notes about
1723 * how this behavior will change in libpng 1.7
1724 */
1725 PNG_EXPORT(88, void, png_set_read_user_chunk_fn, (png_structrp png_ptr,
1726 png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));
1727 #endif
1728
1729 #ifdef PNG_USER_CHUNKS_SUPPORTED
1730 PNG_EXPORT(89, png_voidp, png_get_user_chunk_ptr, (png_const_structrp png_ptr));
1731 #endif
1732
1733 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1734 /* Sets the function callbacks for the push reader, and a pointer to a
1735 * user-defined structure available to the callback functions.
1736 */
1737 PNG_EXPORT(90, void, png_set_progressive_read_fn, (png_structrp png_ptr,
1738 png_voidp progressive_ptr, png_progressive_info_ptr info_fn,
1739 png_progressive_row_ptr row_fn, png_progressive_end_ptr end_fn));
1740
1741 /* Returns the user pointer associated with the push read functions */
1742 PNG_EXPORT(91, png_voidp, png_get_progressive_ptr,
1743 (png_const_structrp png_ptr));
1744
1745 /* Function to be called when data becomes available */
1746 PNG_EXPORT(92, void, png_process_data, (png_structrp png_ptr,
1747 png_inforp info_ptr, png_bytep buffer, size_t buffer_size));
1748
1749 /* A function which may be called *only* within png_process_data to stop the
1750 * processing of any more data. The function returns the number of bytes
1751 * remaining, excluding any that libpng has cached internally. A subsequent
1752 * call to png_process_data must supply these bytes again. If the argument
1753 * 'save' is set to true the routine will first save all the pending data and
1754 * will always return 0.
1755 */
1756 PNG_EXPORT(219, size_t, png_process_data_pause, (png_structrp, int save));
1757
1758 /* A function which may be called *only* outside (after) a call to
1759 * png_process_data. It returns the number of bytes of data to skip in the
1760 * input. Normally it will return 0, but if it returns a non-zero value the
1761 * application must skip than number of bytes of input data and pass the
1762 * following data to the next call to png_process_data.
1763 */
1764 PNG_EXPORT(220, png_uint_32, png_process_data_skip, (png_structrp));
1765
1766 /* Function that combines rows. 'new_row' is a flag that should come from
1767 * the callback and be non-NULL if anything needs to be done; the library
1768 * stores its own version of the new data internally and ignores the passed
1769 * in value.
1770 */
1771 PNG_EXPORT(93, void, png_progressive_combine_row, (png_const_structrp png_ptr,
1772 png_bytep old_row, png_const_bytep new_row));
1773 #endif /* PROGRESSIVE_READ */
1774
1775 PNG_EXPORTA(94, png_voidp, png_malloc, (png_const_structrp png_ptr,
1776 png_alloc_size_t size), PNG_ALLOCATED);
1777 /* Added at libpng version 1.4.0 */
1778 PNG_EXPORTA(95, png_voidp, png_calloc, (png_const_structrp png_ptr,
1779 png_alloc_size_t size), PNG_ALLOCATED);
1780
1781 /* Added at libpng version 1.2.4 */
1782 PNG_EXPORTA(96, png_voidp, png_malloc_warn, (png_const_structrp png_ptr,
1783 png_alloc_size_t size), PNG_ALLOCATED);
1784
1785 /* Frees a pointer allocated by png_malloc() */
1786 PNG_EXPORT(97, void, png_free, (png_const_structrp png_ptr, png_voidp ptr));
1787
1788 /* Free data that was allocated internally */
1789 PNG_EXPORT(98, void, png_free_data, (png_const_structrp png_ptr,
1790 png_inforp info_ptr, png_uint_32 free_me, int num));
1791
1792 /* Reassign responsibility for freeing existing data, whether allocated
1793 * by libpng or by the application; this works on the png_info structure passed
1794 * in, it does not change the state for other png_info structures.
1795 *
1796 * It is unlikely that this function works correctly as of 1.6.0 and using it
1797 * may result either in memory leaks or double free of allocated data.
1798 */
1799 PNG_EXPORT(99, void, png_data_freer, (png_const_structrp png_ptr,
1800 png_inforp info_ptr, int freer, png_uint_32 mask));
1801
1802 /* Assignments for png_data_freer */
1803 #define PNG_DESTROY_WILL_FREE_DATA 1
1804 #define PNG_SET_WILL_FREE_DATA 1
1805 #define PNG_USER_WILL_FREE_DATA 2
1806 /* Flags for png_ptr->free_me and info_ptr->free_me */
1807 #define PNG_FREE_HIST 0x0008U
1808 #define PNG_FREE_ICCP 0x0010U
1809 #define PNG_FREE_SPLT 0x0020U
1810 #define PNG_FREE_ROWS 0x0040U
1811 #define PNG_FREE_PCAL 0x0080U
1812 #define PNG_FREE_SCAL 0x0100U
1813 #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
1814 # define PNG_FREE_UNKN 0x0200U
1815 #endif
1816 /* PNG_FREE_LIST 0x0400U removed in 1.6.0 because it is ignored */
1817 #define PNG_FREE_PLTE 0x1000U
1818 #define PNG_FREE_TRNS 0x2000U
1819 #define PNG_FREE_TEXT 0x4000U
1820 #define PNG_FREE_EXIF 0x8000U /* Added at libpng-1.6.31 */
1821 #define PNG_FREE_ALL 0xffffU
1822 #define PNG_FREE_MUL 0x4220U /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */
1823
1824 #ifdef PNG_USER_MEM_SUPPORTED
1825 PNG_EXPORTA(100, png_voidp, png_malloc_default, (png_const_structrp png_ptr,
1826 png_alloc_size_t size), PNG_ALLOCATED PNG_DEPRECATED);
1827 PNG_EXPORTA(101, void, png_free_default, (png_const_structrp png_ptr,
1828 png_voidp ptr), PNG_DEPRECATED);
1829 #endif
1830
1831 #ifdef PNG_ERROR_TEXT_SUPPORTED
1832 /* Fatal error in PNG image of libpng - can't continue */
1833 PNG_EXPORTA(102, void, png_error, (png_const_structrp png_ptr,
1834 png_const_charp error_message), PNG_NORETURN);
1835
1836 /* The same, but the chunk name is prepended to the error string. */
1837 PNG_EXPORTA(103, void, png_chunk_error, (png_const_structrp png_ptr,
1838 png_const_charp error_message), PNG_NORETURN);
1839
1840 #else
1841 /* Fatal error in PNG image of libpng - can't continue */
1842 PNG_EXPORTA(104, void, png_err, (png_const_structrp png_ptr), PNG_NORETURN);
1843 # define png_error(s1,s2) png_err(s1)
1844 # define png_chunk_error(s1,s2) png_err(s1)
1845 #endif
1846
1847 #ifdef PNG_WARNINGS_SUPPORTED
1848 /* Non-fatal error in libpng. Can continue, but may have a problem. */
1849 PNG_EXPORT(105, void, png_warning, (png_const_structrp png_ptr,
1850 png_const_charp warning_message));
1851
1852 /* Non-fatal error in libpng, chunk name is prepended to message. */
1853 PNG_EXPORT(106, void, png_chunk_warning, (png_const_structrp png_ptr,
1854 png_const_charp warning_message));
1855 #else
1856 # define png_warning(s1,s2) ((void)(s1))
1857 # define png_chunk_warning(s1,s2) ((void)(s1))
1858 #endif
1859
1860 #ifdef PNG_BENIGN_ERRORS_SUPPORTED
1861 /* Benign error in libpng. Can continue, but may have a problem.
1862 * User can choose whether to handle as a fatal error or as a warning. */
1863 PNG_EXPORT(107, void, png_benign_error, (png_const_structrp png_ptr,
1864 png_const_charp warning_message));
1865
1866 #ifdef PNG_READ_SUPPORTED
1867 /* Same, chunk name is prepended to message (only during read) */
1868 PNG_EXPORT(108, void, png_chunk_benign_error, (png_const_structrp png_ptr,
1869 png_const_charp warning_message));
1870 #endif
1871
1872 PNG_EXPORT(109, void, png_set_benign_errors,
1873 (png_structrp png_ptr, int allowed));
1874 #else
1875 # ifdef PNG_ALLOW_BENIGN_ERRORS
1876 # define png_benign_error png_warning
1877 # define png_chunk_benign_error png_chunk_warning
1878 # else
1879 # define png_benign_error png_error
1880 # define png_chunk_benign_error png_chunk_error
1881 # endif
1882 #endif
1883
1884 /* The png_set_<chunk> functions are for storing values in the png_info_struct.
1885 * Similarly, the png_get_<chunk> calls are used to read values from the
1886 * png_info_struct, either storing the parameters in the passed variables, or
1887 * setting pointers into the png_info_struct where the data is stored. The
1888 * png_get_<chunk> functions return a non-zero value if the data was available
1889 * in info_ptr, or return zero and do not change any of the parameters if the
1890 * data was not available.
1891 *
1892 * These functions should be used instead of directly accessing png_info
1893 * to avoid problems with future changes in the size and internal layout of
1894 * png_info_struct.
1895 */
1896 /* Returns "flag" if chunk data is valid in info_ptr. */
1897 PNG_EXPORT(110, png_uint_32, png_get_valid, (png_const_structrp png_ptr,
1898 png_const_inforp info_ptr, png_uint_32 flag));
1899
1900 /* Returns number of bytes needed to hold a transformed row. */
1901 PNG_EXPORT(111, size_t, png_get_rowbytes, (png_const_structrp png_ptr,
1902 png_const_inforp info_ptr));
1903
1904 #ifdef PNG_INFO_IMAGE_SUPPORTED
1905 /* Returns row_pointers, which is an array of pointers to scanlines that was
1906 * returned from png_read_png().
1907 */
1908 PNG_EXPORT(112, png_bytepp, png_get_rows, (png_const_structrp png_ptr,
1909 png_const_inforp info_ptr));
1910
1911 /* Set row_pointers, which is an array of pointers to scanlines for use
1912 * by png_write_png().
1913 */
1914 PNG_EXPORT(113, void, png_set_rows, (png_const_structrp png_ptr,
1915 png_inforp info_ptr, png_bytepp row_pointers));
1916 #endif
1917
1918 /* Returns number of color channels in image. */
1919 PNG_EXPORT(114, png_byte, png_get_channels, (png_const_structrp png_ptr,
1920 png_const_inforp info_ptr));
1921
1922 #ifdef PNG_EASY_ACCESS_SUPPORTED
1923 /* Returns image width in pixels. */
1924 PNG_EXPORT(115, png_uint_32, png_get_image_width, (png_const_structrp png_ptr,
1925 png_const_inforp info_ptr));
1926
1927 /* Returns image height in pixels. */
1928 PNG_EXPORT(116, png_uint_32, png_get_image_height, (png_const_structrp png_ptr,
1929 png_const_inforp info_ptr));
1930
1931 /* Returns image bit_depth. */
1932 PNG_EXPORT(117, png_byte, png_get_bit_depth, (png_const_structrp png_ptr,
1933 png_const_inforp info_ptr));
1934
1935 /* Returns image color_type. */
1936 PNG_EXPORT(118, png_byte, png_get_color_type, (png_const_structrp png_ptr,
1937 png_const_inforp info_ptr));
1938
1939 /* Returns image filter_type. */
1940 PNG_EXPORT(119, png_byte, png_get_filter_type, (png_const_structrp png_ptr,
1941 png_const_inforp info_ptr));
1942
1943 /* Returns image interlace_type. */
1944 PNG_EXPORT(120, png_byte, png_get_interlace_type, (png_const_structrp png_ptr,
1945 png_const_inforp info_ptr));
1946
1947 /* Returns image compression_type. */
1948 PNG_EXPORT(121, png_byte, png_get_compression_type, (png_const_structrp png_ptr,
1949 png_const_inforp info_ptr));
1950
1951 /* Returns image resolution in pixels per meter, from pHYs chunk data. */
1952 PNG_EXPORT(122, png_uint_32, png_get_pixels_per_meter,
1953 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1954 PNG_EXPORT(123, png_uint_32, png_get_x_pixels_per_meter,
1955 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1956 PNG_EXPORT(124, png_uint_32, png_get_y_pixels_per_meter,
1957 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1958
1959 /* Returns pixel aspect ratio, computed from pHYs chunk data. */
1960 PNG_FP_EXPORT(125, float, png_get_pixel_aspect_ratio,
1961 (png_const_structrp png_ptr, png_const_inforp info_ptr))
1962 PNG_FIXED_EXPORT(210, png_fixed_point, png_get_pixel_aspect_ratio_fixed,
1963 (png_const_structrp png_ptr, png_const_inforp info_ptr))
1964
1965 /* Returns image x, y offset in pixels or microns, from oFFs chunk data. */
1966 PNG_EXPORT(126, png_int_32, png_get_x_offset_pixels,
1967 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1968 PNG_EXPORT(127, png_int_32, png_get_y_offset_pixels,
1969 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1970 PNG_EXPORT(128, png_int_32, png_get_x_offset_microns,
1971 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1972 PNG_EXPORT(129, png_int_32, png_get_y_offset_microns,
1973 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1974
1975 #endif /* EASY_ACCESS */
1976
1977 #ifdef PNG_READ_SUPPORTED
1978 /* Returns pointer to signature string read from PNG header */
1979 PNG_EXPORT(130, png_const_bytep, png_get_signature, (png_const_structrp png_ptr,
1980 png_const_inforp info_ptr));
1981 #endif
1982
1983 #ifdef PNG_bKGD_SUPPORTED
1984 PNG_EXPORT(131, png_uint_32, png_get_bKGD, (png_const_structrp png_ptr,
1985 png_inforp info_ptr, png_color_16p *background));
1986 #endif
1987
1988 #ifdef PNG_bKGD_SUPPORTED
1989 PNG_EXPORT(132, void, png_set_bKGD, (png_const_structrp png_ptr,
1990 png_inforp info_ptr, png_const_color_16p background));
1991 #endif
1992
1993 #ifdef PNG_cHRM_SUPPORTED
1994 PNG_FP_EXPORT(133, png_uint_32, png_get_cHRM, (png_const_structrp png_ptr,
1995 png_const_inforp info_ptr, double *white_x, double *white_y, double *red_x,
1996 double *red_y, double *green_x, double *green_y, double *blue_x,
1997 double *blue_y))
1998 PNG_FP_EXPORT(230, png_uint_32, png_get_cHRM_XYZ, (png_const_structrp png_ptr,
1999 png_const_inforp info_ptr, double *red_X, double *red_Y, double *red_Z,
2000 double *green_X, double *green_Y, double *green_Z, double *blue_X,
2001 double *blue_Y, double *blue_Z))
2002 PNG_FIXED_EXPORT(134, png_uint_32, png_get_cHRM_fixed,
2003 (png_const_structrp png_ptr, png_const_inforp info_ptr,
2004 png_fixed_point *int_white_x, png_fixed_point *int_white_y,
2005 png_fixed_point *int_red_x, png_fixed_point *int_red_y,
2006 png_fixed_point *int_green_x, png_fixed_point *int_green_y,
2007 png_fixed_point *int_blue_x, png_fixed_point *int_blue_y))
2008 PNG_FIXED_EXPORT(231, png_uint_32, png_get_cHRM_XYZ_fixed,
2009 (png_const_structrp png_ptr, png_const_inforp info_ptr,
2010 png_fixed_point *int_red_X, png_fixed_point *int_red_Y,
2011 png_fixed_point *int_red_Z, png_fixed_point *int_green_X,
2012 png_fixed_point *int_green_Y, png_fixed_point *int_green_Z,
2013 png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y,
2014 png_fixed_point *int_blue_Z))
2015 #endif
2016
2017 #ifdef PNG_cHRM_SUPPORTED
2018 PNG_FP_EXPORT(135, void, png_set_cHRM, (png_const_structrp png_ptr,
2019 png_inforp info_ptr,
2020 double white_x, double white_y, double red_x, double red_y, double green_x,
2021 double green_y, double blue_x, double blue_y))
2022 PNG_FP_EXPORT(232, void, png_set_cHRM_XYZ, (png_const_structrp png_ptr,
2023 png_inforp info_ptr, double red_X, double red_Y, double red_Z,
2024 double green_X, double green_Y, double green_Z, double blue_X,
2025 double blue_Y, double blue_Z))
2026 PNG_FIXED_EXPORT(136, void, png_set_cHRM_fixed, (png_const_structrp png_ptr,
2027 png_inforp info_ptr, png_fixed_point int_white_x,
2028 png_fixed_point int_white_y, png_fixed_point int_red_x,
2029 png_fixed_point int_red_y, png_fixed_point int_green_x,
2030 png_fixed_point int_green_y, png_fixed_point int_blue_x,
2031 png_fixed_point int_blue_y))
2032 PNG_FIXED_EXPORT(233, void, png_set_cHRM_XYZ_fixed, (png_const_structrp png_ptr,
2033 png_inforp info_ptr, png_fixed_point int_red_X, png_fixed_point int_red_Y,
2034 png_fixed_point int_red_Z, png_fixed_point int_green_X,
2035 png_fixed_point int_green_Y, png_fixed_point int_green_Z,
2036 png_fixed_point int_blue_X, png_fixed_point int_blue_Y,
2037 png_fixed_point int_blue_Z))
2038 #endif
2039
2040 #ifdef PNG_eXIf_SUPPORTED
2041 PNG_EXPORT(246, png_uint_32, png_get_eXIf, (png_const_structrp png_ptr,
2042 png_inforp info_ptr, png_bytep *exif));
2043 PNG_EXPORT(247, void, png_set_eXIf, (png_const_structrp png_ptr,
2044 png_inforp info_ptr, const png_bytep exif));
2045
2046 PNG_EXPORT(248, png_uint_32, png_get_eXIf_1, (png_const_structrp png_ptr,
2047 png_const_inforp info_ptr, png_uint_32 *num_exif, png_bytep *exif));
2048 PNG_EXPORT(249, void, png_set_eXIf_1, (png_const_structrp png_ptr,
2049 png_inforp info_ptr, const png_uint_32 num_exif, const png_bytep exif));
2050 #endif
2051
2052 #ifdef PNG_gAMA_SUPPORTED
2053 PNG_FP_EXPORT(137, png_uint_32, png_get_gAMA, (png_const_structrp png_ptr,
2054 png_const_inforp info_ptr, double *file_gamma))
2055 PNG_FIXED_EXPORT(138, png_uint_32, png_get_gAMA_fixed,
2056 (png_const_structrp png_ptr, png_const_inforp info_ptr,
2057 png_fixed_point *int_file_gamma))
2058 #endif
2059
2060 #ifdef PNG_gAMA_SUPPORTED
2061 PNG_FP_EXPORT(139, void, png_set_gAMA, (png_const_structrp png_ptr,
2062 png_inforp info_ptr, double file_gamma))
2063 PNG_FIXED_EXPORT(140, void, png_set_gAMA_fixed, (png_const_structrp png_ptr,
2064 png_inforp info_ptr, png_fixed_point int_file_gamma))
2065 #endif
2066
2067 #ifdef PNG_hIST_SUPPORTED
2068 PNG_EXPORT(141, png_uint_32, png_get_hIST, (png_const_structrp png_ptr,
2069 png_inforp info_ptr, png_uint_16p *hist));
2070 PNG_EXPORT(142, void, png_set_hIST, (png_const_structrp png_ptr,
2071 png_inforp info_ptr, png_const_uint_16p hist));
2072 #endif
2073
2074 PNG_EXPORT(143, png_uint_32, png_get_IHDR, (png_const_structrp png_ptr,
2075 png_const_inforp info_ptr, png_uint_32 *width, png_uint_32 *height,
2076 int *bit_depth, int *color_type, int *interlace_method,
2077 int *compression_method, int *filter_method));
2078
2079 PNG_EXPORT(144, void, png_set_IHDR, (png_const_structrp png_ptr,
2080 png_inforp info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth,
2081 int color_type, int interlace_method, int compression_method,
2082 int filter_method));
2083
2084 #ifdef PNG_oFFs_SUPPORTED
2085 PNG_EXPORT(145, png_uint_32, png_get_oFFs, (png_const_structrp png_ptr,
2086 png_const_inforp info_ptr, png_int_32 *offset_x, png_int_32 *offset_y,
2087 int *unit_type));
2088 #endif
2089
2090 #ifdef PNG_oFFs_SUPPORTED
2091 PNG_EXPORT(146, void, png_set_oFFs, (png_const_structrp png_ptr,
2092 png_inforp info_ptr, png_int_32 offset_x, png_int_32 offset_y,
2093 int unit_type));
2094 #endif
2095
2096 #ifdef PNG_pCAL_SUPPORTED
2097 PNG_EXPORT(147, png_uint_32, png_get_pCAL, (png_const_structrp png_ptr,
2098 png_inforp info_ptr, png_charp *purpose, png_int_32 *X0,
2099 png_int_32 *X1, int *type, int *nparams, png_charp *units,
2100 png_charpp *params));
2101 #endif
2102
2103 #ifdef PNG_pCAL_SUPPORTED
2104 PNG_EXPORT(148, void, png_set_pCAL, (png_const_structrp png_ptr,
2105 png_inforp info_ptr, png_const_charp purpose, png_int_32 X0, png_int_32 X1,
2106 int type, int nparams, png_const_charp units, png_charpp params));
2107 #endif
2108
2109 #ifdef PNG_pHYs_SUPPORTED
2110 PNG_EXPORT(149, png_uint_32, png_get_pHYs, (png_const_structrp png_ptr,
2111 png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y,
2112 int *unit_type));
2113 #endif
2114
2115 #ifdef PNG_pHYs_SUPPORTED
2116 PNG_EXPORT(150, void, png_set_pHYs, (png_const_structrp png_ptr,
2117 png_inforp info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type));
2118 #endif
2119
2120 PNG_EXPORT(151, png_uint_32, png_get_PLTE, (png_const_structrp png_ptr,
2121 png_inforp info_ptr, png_colorp *palette, int *num_palette));
2122
2123 PNG_EXPORT(152, void, png_set_PLTE, (png_structrp png_ptr,
2124 png_inforp info_ptr, png_const_colorp palette, int num_palette));
2125
2126 #ifdef PNG_sBIT_SUPPORTED
2127 PNG_EXPORT(153, png_uint_32, png_get_sBIT, (png_const_structrp png_ptr,
2128 png_inforp info_ptr, png_color_8p *sig_bit));
2129 #endif
2130
2131 #ifdef PNG_sBIT_SUPPORTED
2132 PNG_EXPORT(154, void, png_set_sBIT, (png_const_structrp png_ptr,
2133 png_inforp info_ptr, png_const_color_8p sig_bit));
2134 #endif
2135
2136 #ifdef PNG_sRGB_SUPPORTED
2137 PNG_EXPORT(155, png_uint_32, png_get_sRGB, (png_const_structrp png_ptr,
2138 png_const_inforp info_ptr, int *file_srgb_intent));
2139 #endif
2140
2141 #ifdef PNG_sRGB_SUPPORTED
2142 PNG_EXPORT(156, void, png_set_sRGB, (png_const_structrp png_ptr,
2143 png_inforp info_ptr, int srgb_intent));
2144 PNG_EXPORT(157, void, png_set_sRGB_gAMA_and_cHRM, (png_const_structrp png_ptr,
2145 png_inforp info_ptr, int srgb_intent));
2146 #endif
2147
2148 #ifdef PNG_iCCP_SUPPORTED
2149 PNG_EXPORT(158, png_uint_32, png_get_iCCP, (png_const_structrp png_ptr,
2150 png_inforp info_ptr, png_charpp name, int *compression_type,
2151 png_bytepp profile, png_uint_32 *proflen));
2152 #endif
2153
2154 #ifdef PNG_iCCP_SUPPORTED
2155 PNG_EXPORT(159, void, png_set_iCCP, (png_const_structrp png_ptr,
2156 png_inforp info_ptr, png_const_charp name, int compression_type,
2157 png_const_bytep profile, png_uint_32 proflen));
2158 #endif
2159
2160 #ifdef PNG_sPLT_SUPPORTED
2161 PNG_EXPORT(160, int, png_get_sPLT, (png_const_structrp png_ptr,
2162 png_inforp info_ptr, png_sPLT_tpp entries));
2163 #endif
2164
2165 #ifdef PNG_sPLT_SUPPORTED
2166 PNG_EXPORT(161, void, png_set_sPLT, (png_const_structrp png_ptr,
2167 png_inforp info_ptr, png_const_sPLT_tp entries, int nentries));
2168 #endif
2169
2170 #ifdef PNG_TEXT_SUPPORTED
2171 /* png_get_text also returns the number of text chunks in *num_text */
2172 PNG_EXPORT(162, int, png_get_text, (png_const_structrp png_ptr,
2173 png_inforp info_ptr, png_textp *text_ptr, int *num_text));
2174 #endif
2175
2176 /* Note while png_set_text() will accept a structure whose text,
2177 * language, and translated keywords are NULL pointers, the structure
2178 * returned by png_get_text will always contain regular
2179 * zero-terminated C strings. They might be empty strings but
2180 * they will never be NULL pointers.
2181 */
2182
2183 #ifdef PNG_TEXT_SUPPORTED
2184 PNG_EXPORT(163, void, png_set_text, (png_const_structrp png_ptr,
2185 png_inforp info_ptr, png_const_textp text_ptr, int num_text));
2186 #endif
2187
2188 #ifdef PNG_tIME_SUPPORTED
2189 PNG_EXPORT(164, png_uint_32, png_get_tIME, (png_const_structrp png_ptr,
2190 png_inforp info_ptr, png_timep *mod_time));
2191 #endif
2192
2193 #ifdef PNG_tIME_SUPPORTED
2194 PNG_EXPORT(165, void, png_set_tIME, (png_const_structrp png_ptr,
2195 png_inforp info_ptr, png_const_timep mod_time));
2196 #endif
2197
2198 #ifdef PNG_tRNS_SUPPORTED
2199 PNG_EXPORT(166, png_uint_32, png_get_tRNS, (png_const_structrp png_ptr,
2200 png_inforp info_ptr, png_bytep *trans_alpha, int *num_trans,
2201 png_color_16p *trans_color));
2202 #endif
2203
2204 #ifdef PNG_tRNS_SUPPORTED
2205 PNG_EXPORT(167, void, png_set_tRNS, (png_structrp png_ptr,
2206 png_inforp info_ptr, png_const_bytep trans_alpha, int num_trans,
2207 png_const_color_16p trans_color));
2208 #endif
2209
2210 #ifdef PNG_sCAL_SUPPORTED
2211 PNG_FP_EXPORT(168, png_uint_32, png_get_sCAL, (png_const_structrp png_ptr,
2212 png_const_inforp info_ptr, int *unit, double *width, double *height))
2213 #if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || \
2214 defined(PNG_FLOATING_POINT_SUPPORTED)
2215 /* NOTE: this API is currently implemented using floating point arithmetic,
2216 * consequently it can only be used on systems with floating point support.
2217 * In any case the range of values supported by png_fixed_point is small and it
2218 * is highly recommended that png_get_sCAL_s be used instead.
2219 */
2220 PNG_FIXED_EXPORT(214, png_uint_32, png_get_sCAL_fixed,
2221 (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit,
2222 png_fixed_point *width, png_fixed_point *height))
2223 #endif
2224 PNG_EXPORT(169, png_uint_32, png_get_sCAL_s,
2225 (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit,
2226 png_charpp swidth, png_charpp sheight));
2227
2228 PNG_FP_EXPORT(170, void, png_set_sCAL, (png_const_structrp png_ptr,
2229 png_inforp info_ptr, int unit, double width, double height))
2230 PNG_FIXED_EXPORT(213, void, png_set_sCAL_fixed, (png_const_structrp png_ptr,
2231 png_inforp info_ptr, int unit, png_fixed_point width,
2232 png_fixed_point height))
2233 PNG_EXPORT(171, void, png_set_sCAL_s, (png_const_structrp png_ptr,
2234 png_inforp info_ptr, int unit,
2235 png_const_charp swidth, png_const_charp sheight));
2236 #endif /* sCAL */
2237
2238 #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
2239 /* Provide the default handling for all unknown chunks or, optionally, for
2240 * specific unknown chunks.
2241 *
2242 * NOTE: prior to 1.6.0 the handling specified for particular chunks on read was
2243 * ignored and the default was used, the per-chunk setting only had an effect on
2244 * write. If you wish to have chunk-specific handling on read in code that must
2245 * work on earlier versions you must use a user chunk callback to specify the
2246 * desired handling (keep or discard.)
2247 *
2248 * The 'keep' parameter is a PNG_HANDLE_CHUNK_ value as listed below. The
2249 * parameter is interpreted as follows:
2250 *
2251 * READ:
2252 * PNG_HANDLE_CHUNK_AS_DEFAULT:
2253 * Known chunks: do normal libpng processing, do not keep the chunk (but
2254 * see the comments below about PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
2255 * Unknown chunks: for a specific chunk use the global default, when used
2256 * as the default discard the chunk data.
2257 * PNG_HANDLE_CHUNK_NEVER:
2258 * Discard the chunk data.
2259 * PNG_HANDLE_CHUNK_IF_SAFE:
2260 * Keep the chunk data if the chunk is not critical else raise a chunk
2261 * error.
2262 * PNG_HANDLE_CHUNK_ALWAYS:
2263 * Keep the chunk data.
2264 *
2265 * If the chunk data is saved it can be retrieved using png_get_unknown_chunks,
2266 * below. Notice that specifying "AS_DEFAULT" as a global default is equivalent
2267 * to specifying "NEVER", however when "AS_DEFAULT" is used for specific chunks
2268 * it simply resets the behavior to the libpng default.
2269 *
2270 * INTERACTION WITH USER CHUNK CALLBACKS:
2271 * The per-chunk handling is always used when there is a png_user_chunk_ptr
2272 * callback and the callback returns 0; the chunk is then always stored *unless*
2273 * it is critical and the per-chunk setting is other than ALWAYS. Notice that
2274 * the global default is *not* used in this case. (In effect the per-chunk
2275 * value is incremented to at least IF_SAFE.)
2276 *
2277 * IMPORTANT NOTE: this behavior will change in libpng 1.7 - the global and
2278 * per-chunk defaults will be honored. If you want to preserve the current
2279 * behavior when your callback returns 0 you must set PNG_HANDLE_CHUNK_IF_SAFE
2280 * as the default - if you don't do this libpng 1.6 will issue a warning.
2281 *
2282 * If you want unhandled unknown chunks to be discarded in libpng 1.6 and
2283 * earlier simply return '1' (handled).
2284 *
2285 * PNG_HANDLE_AS_UNKNOWN_SUPPORTED:
2286 * If this is *not* set known chunks will always be handled by libpng and
2287 * will never be stored in the unknown chunk list. Known chunks listed to
2288 * png_set_keep_unknown_chunks will have no effect. If it is set then known
2289 * chunks listed with a keep other than AS_DEFAULT will *never* be processed
2290 * by libpng, in addition critical chunks must either be processed by the
2291 * callback or saved.
2292 *
2293 * The IHDR and IEND chunks must not be listed. Because this turns off the
2294 * default handling for chunks that would otherwise be recognized the
2295 * behavior of libpng transformations may well become incorrect!
2296 *
2297 * WRITE:
2298 * When writing chunks the options only apply to the chunks specified by
2299 * png_set_unknown_chunks (below), libpng will *always* write known chunks
2300 * required by png_set_ calls and will always write the core critical chunks
2301 * (as required for PLTE).
2302 *
2303 * Each chunk in the png_set_unknown_chunks list is looked up in the
2304 * png_set_keep_unknown_chunks list to find the keep setting, this is then
2305 * interpreted as follows:
2306 *
2307 * PNG_HANDLE_CHUNK_AS_DEFAULT:
2308 * Write safe-to-copy chunks and write other chunks if the global
2309 * default is set to _ALWAYS, otherwise don't write this chunk.
2310 * PNG_HANDLE_CHUNK_NEVER:
2311 * Do not write the chunk.
2312 * PNG_HANDLE_CHUNK_IF_SAFE:
2313 * Write the chunk if it is safe-to-copy, otherwise do not write it.
2314 * PNG_HANDLE_CHUNK_ALWAYS:
2315 * Write the chunk.
2316 *
2317 * Note that the default behavior is effectively the opposite of the read case -
2318 * in read unknown chunks are not stored by default, in write they are written
2319 * by default. Also the behavior of PNG_HANDLE_CHUNK_IF_SAFE is very different
2320 * - on write the safe-to-copy bit is checked, on read the critical bit is
2321 * checked and on read if the chunk is critical an error will be raised.
2322 *
2323 * num_chunks:
2324 * ===========
2325 * If num_chunks is positive, then the "keep" parameter specifies the manner
2326 * for handling only those chunks appearing in the chunk_list array,
2327 * otherwise the chunk list array is ignored.
2328 *
2329 * If num_chunks is 0 the "keep" parameter specifies the default behavior for
2330 * unknown chunks, as described above.
2331 *
2332 * If num_chunks is negative, then the "keep" parameter specifies the manner
2333 * for handling all unknown chunks plus all chunks recognized by libpng
2334 * except for the IHDR, PLTE, tRNS, IDAT, and IEND chunks (which continue to
2335 * be processed by libpng.
2336 */
2337 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
2338 PNG_EXPORT(172, void, png_set_keep_unknown_chunks, (png_structrp png_ptr,
2339 int keep, png_const_bytep chunk_list, int num_chunks));
2340 #endif /* HANDLE_AS_UNKNOWN */
2341
2342 /* The "keep" PNG_HANDLE_CHUNK_ parameter for the specified chunk is returned;
2343 * the result is therefore true (non-zero) if special handling is required,
2344 * false for the default handling.
2345 */
2346 PNG_EXPORT(173, int, png_handle_as_unknown, (png_const_structrp png_ptr,
2347 png_const_bytep chunk_name));
2348 #endif /* SET_UNKNOWN_CHUNKS */
2349
2350 #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
2351 PNG_EXPORT(174, void, png_set_unknown_chunks, (png_const_structrp png_ptr,
2352 png_inforp info_ptr, png_const_unknown_chunkp unknowns,
2353 int num_unknowns));
2354 /* NOTE: prior to 1.6.0 this routine set the 'location' field of the added
2355 * unknowns to the location currently stored in the png_struct. This is
2356 * invariably the wrong value on write. To fix this call the following API
2357 * for each chunk in the list with the correct location. If you know your
2358 * code won't be compiled on earlier versions you can rely on
2359 * png_set_unknown_chunks(write-ptr, png_get_unknown_chunks(read-ptr)) doing
2360 * the correct thing.
2361 */
2362
2363 PNG_EXPORT(175, void, png_set_unknown_chunk_location,
2364 (png_const_structrp png_ptr, png_inforp info_ptr, int chunk, int location));
2365
2366 PNG_EXPORT(176, int, png_get_unknown_chunks, (png_const_structrp png_ptr,
2367 png_inforp info_ptr, png_unknown_chunkpp entries));
2368 #endif
2369
2370 /* Png_free_data() will turn off the "valid" flag for anything it frees.
2371 * If you need to turn it off for a chunk that your application has freed,
2372 * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK);
2373 */
2374 PNG_EXPORT(177, void, png_set_invalid, (png_const_structrp png_ptr,
2375 png_inforp info_ptr, int mask));
2376
2377 #ifdef PNG_INFO_IMAGE_SUPPORTED
2378 /* The "params" pointer is currently not used and is for future expansion. */
2379 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
2380 PNG_EXPORT(178, void, png_read_png, (png_structrp png_ptr, png_inforp info_ptr,
2381 int transforms, png_voidp params));
2382 #endif
2383 #ifdef PNG_WRITE_SUPPORTED
2384 PNG_EXPORT(179, void, png_write_png, (png_structrp png_ptr, png_inforp info_ptr,
2385 int transforms, png_voidp params));
2386 #endif
2387 #endif
2388
2389 PNG_EXPORT(180, png_const_charp, png_get_copyright,
2390 (png_const_structrp png_ptr));
2391 PNG_EXPORT(181, png_const_charp, png_get_header_ver,
2392 (png_const_structrp png_ptr));
2393 PNG_EXPORT(182, png_const_charp, png_get_header_version,
2394 (png_const_structrp png_ptr));
2395 PNG_EXPORT(183, png_const_charp, png_get_libpng_ver,
2396 (png_const_structrp png_ptr));
2397
2398 #ifdef PNG_MNG_FEATURES_SUPPORTED
2399 PNG_EXPORT(184, png_uint_32, png_permit_mng_features, (png_structrp png_ptr,
2400 png_uint_32 mng_features_permitted));
2401 #endif
2402
2403 /* For use in png_set_keep_unknown, added to version 1.2.6 */
2404 #define PNG_HANDLE_CHUNK_AS_DEFAULT 0
2405 #define PNG_HANDLE_CHUNK_NEVER 1
2406 #define PNG_HANDLE_CHUNK_IF_SAFE 2
2407 #define PNG_HANDLE_CHUNK_ALWAYS 3
2408 #define PNG_HANDLE_CHUNK_LAST 4
2409
2410 /* Strip the prepended error numbers ("#nnn ") from error and warning
2411 * messages before passing them to the error or warning handler.
2412 */
2413 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
2414 PNG_EXPORT(185, void, png_set_strip_error_numbers, (png_structrp png_ptr,
2415 png_uint_32 strip_mode));
2416 #endif
2417
2418 /* Added in libpng-1.2.6 */
2419 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
2420 PNG_EXPORT(186, void, png_set_user_limits, (png_structrp png_ptr,
2421 png_uint_32 user_width_max, png_uint_32 user_height_max));
2422 PNG_EXPORT(187, png_uint_32, png_get_user_width_max,
2423 (png_const_structrp png_ptr));
2424 PNG_EXPORT(188, png_uint_32, png_get_user_height_max,
2425 (png_const_structrp png_ptr));
2426 /* Added in libpng-1.4.0 */
2427 PNG_EXPORT(189, void, png_set_chunk_cache_max, (png_structrp png_ptr,
2428 png_uint_32 user_chunk_cache_max));
2429 PNG_EXPORT(190, png_uint_32, png_get_chunk_cache_max,
2430 (png_const_structrp png_ptr));
2431 /* Added in libpng-1.4.1 */
2432 PNG_EXPORT(191, void, png_set_chunk_malloc_max, (png_structrp png_ptr,
2433 png_alloc_size_t user_chunk_cache_max));
2434 PNG_EXPORT(192, png_alloc_size_t, png_get_chunk_malloc_max,
2435 (png_const_structrp png_ptr));
2436 #endif
2437
2438 #if defined(PNG_INCH_CONVERSIONS_SUPPORTED)
2439 PNG_EXPORT(193, png_uint_32, png_get_pixels_per_inch,
2440 (png_const_structrp png_ptr, png_const_inforp info_ptr));
2441
2442 PNG_EXPORT(194, png_uint_32, png_get_x_pixels_per_inch,
2443 (png_const_structrp png_ptr, png_const_inforp info_ptr));
2444
2445 PNG_EXPORT(195, png_uint_32, png_get_y_pixels_per_inch,
2446 (png_const_structrp png_ptr, png_const_inforp info_ptr));
2447
2448 PNG_FP_EXPORT(196, float, png_get_x_offset_inches,
2449 (png_const_structrp png_ptr, png_const_inforp info_ptr))
2450 #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */
2451 PNG_FIXED_EXPORT(211, png_fixed_point, png_get_x_offset_inches_fixed,
2452 (png_const_structrp png_ptr, png_const_inforp info_ptr))
2453 #endif
2454
2455 PNG_FP_EXPORT(197, float, png_get_y_offset_inches, (png_const_structrp png_ptr,
2456 png_const_inforp info_ptr))
2457 #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */
2458 PNG_FIXED_EXPORT(212, png_fixed_point, png_get_y_offset_inches_fixed,
2459 (png_const_structrp png_ptr, png_const_inforp info_ptr))
2460 #endif
2461
2462 # ifdef PNG_pHYs_SUPPORTED
2463 PNG_EXPORT(198, png_uint_32, png_get_pHYs_dpi, (png_const_structrp png_ptr,
2464 png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y,
2465 int *unit_type));
2466 # endif /* pHYs */
2467 #endif /* INCH_CONVERSIONS */
2468
2469 /* Added in libpng-1.4.0 */
2470 #ifdef PNG_IO_STATE_SUPPORTED
2471 PNG_EXPORT(199, png_uint_32, png_get_io_state, (png_const_structrp png_ptr));
2472
2473 /* Removed from libpng 1.6; use png_get_io_chunk_type. */
2474 PNG_REMOVED(200, png_const_bytep, png_get_io_chunk_name, (png_structrp png_ptr),
2475 PNG_DEPRECATED)
2476
2477 PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type,
2478 (png_const_structrp png_ptr));
2479
2480 /* The flags returned by png_get_io_state() are the following: */
2481 # define PNG_IO_NONE 0x0000 /* no I/O at this moment */
2482 # define PNG_IO_READING 0x0001 /* currently reading */
2483 # define PNG_IO_WRITING 0x0002 /* currently writing */
2484 # define PNG_IO_SIGNATURE 0x0010 /* currently at the file signature */
2485 # define PNG_IO_CHUNK_HDR 0x0020 /* currently at the chunk header */
2486 # define PNG_IO_CHUNK_DATA 0x0040 /* currently at the chunk data */
2487 # define PNG_IO_CHUNK_CRC 0x0080 /* currently at the chunk crc */
2488 # define PNG_IO_MASK_OP 0x000f /* current operation: reading/writing */
2489 # define PNG_IO_MASK_LOC 0x00f0 /* current location: sig/hdr/data/crc */
2490 #endif /* IO_STATE */
2491
2492 /* Interlace support. The following macros are always defined so that if
2493 * libpng interlace handling is turned off the macros may be used to handle
2494 * interlaced images within the application.
2495 */
2496 #define PNG_INTERLACE_ADAM7_PASSES 7
2497
2498 /* Two macros to return the first row and first column of the original,
2499 * full, image which appears in a given pass. 'pass' is in the range 0
2500 * to 6 and the result is in the range 0 to 7.
2501 */
2502 #define PNG_PASS_START_ROW(pass) (((1&~(pass))<<(3-((pass)>>1)))&7)
2503 #define PNG_PASS_START_COL(pass) (((1& (pass))<<(3-(((pass)+1)>>1)))&7)
2504
2505 /* A macro to return the offset between pixels in the output row for a pair of
2506 * pixels in the input - effectively the inverse of the 'COL_SHIFT' macro that
2507 * follows. Note that ROW_OFFSET is the offset from one row to the next whereas
2508 * COL_OFFSET is from one column to the next, within a row.
2509 */
2510 #define PNG_PASS_ROW_OFFSET(pass) ((pass)>2?(8>>(((pass)-1)>>1)):8)
2511 #define PNG_PASS_COL_OFFSET(pass) (1<<((7-(pass))>>1))
2512
2513 /* Two macros to help evaluate the number of rows or columns in each
2514 * pass. This is expressed as a shift - effectively log2 of the number or
2515 * rows or columns in each 8x8 tile of the original image.
2516 */
2517 #define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3)
2518 #define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3)
2519
2520 /* Hence two macros to determine the number of rows or columns in a given
2521 * pass of an image given its height or width. In fact these macros may
2522 * return non-zero even though the sub-image is empty, because the other
2523 * dimension may be empty for a small image.
2524 */
2525 #define PNG_PASS_ROWS(height, pass) (((height)+(((1<<PNG_PASS_ROW_SHIFT(pass))\
2526 -1)-PNG_PASS_START_ROW(pass)))>>PNG_PASS_ROW_SHIFT(pass))
2527 #define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\
2528 -1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass))
2529
2530 /* For the reader row callbacks (both progressive and sequential) it is
2531 * necessary to find the row in the output image given a row in an interlaced
2532 * image, so two more macros:
2533 */
2534 #define PNG_ROW_FROM_PASS_ROW(y_in, pass) \
2535 (((y_in)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass))
2536 #define PNG_COL_FROM_PASS_COL(x_in, pass) \
2537 (((x_in)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass))
2538
2539 /* Two macros which return a boolean (0 or 1) saying whether the given row
2540 * or column is in a particular pass. These use a common utility macro that
2541 * returns a mask for a given pass - the offset 'off' selects the row or
2542 * column version. The mask has the appropriate bit set for each column in
2543 * the tile.
2544 */
2545 #define PNG_PASS_MASK(pass,off) ( \
2546 ((0x110145AF>>(((7-(off))-(pass))<<2)) & 0xF) | \
2547 ((0x01145AF0>>(((7-(off))-(pass))<<2)) & 0xF0))
2548
2549 #define PNG_ROW_IN_INTERLACE_PASS(y, pass) \
2550 ((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1)
2551 #define PNG_COL_IN_INTERLACE_PASS(x, pass) \
2552 ((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1)
2553
2554 #ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
2555 /* With these routines we avoid an integer divide, which will be slower on
2556 * most machines. However, it does take more operations than the corresponding
2557 * divide method, so it may be slower on a few RISC systems. There are two
2558 * shifts (by 8 or 16 bits) and an addition, versus a single integer divide.
2559 *
2560 * Note that the rounding factors are NOT supposed to be the same! 128 and
2561 * 32768 are correct for the NODIV code; 127 and 32767 are correct for the
2562 * standard method.
2563 *
2564 * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
2565 */
2566
2567 /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */
2568
2569 # define png_composite(composite, fg, alpha, bg) \
2570 { \
2571 png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \
2572 * (png_uint_16)(alpha) \
2573 + (png_uint_16)(bg)*(png_uint_16)(255 \
2574 - (png_uint_16)(alpha)) + 128); \
2575 (composite) = (png_byte)(((temp + (temp >> 8)) >> 8) & 0xff); \
2576 }
2577
2578 # define png_composite_16(composite, fg, alpha, bg) \
2579 { \
2580 png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) \
2581 * (png_uint_32)(alpha) \
2582 + (png_uint_32)(bg)*(65535 \
2583 - (png_uint_32)(alpha)) + 32768); \
2584 (composite) = (png_uint_16)(0xffff & ((temp + (temp >> 16)) >> 16)); \
2585 }
2586
2587 #else /* Standard method using integer division */
2588
2589 # define png_composite(composite, fg, alpha, bg) \
2590 (composite) = \
2591 (png_byte)(0xff & (((png_uint_16)(fg) * (png_uint_16)(alpha) + \
2592 (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \
2593 127) / 255))
2594
2595 # define png_composite_16(composite, fg, alpha, bg) \
2596 (composite) = \
2597 (png_uint_16)(0xffff & (((png_uint_32)(fg) * (png_uint_32)(alpha) + \
2598 (png_uint_32)(bg)*(png_uint_32)(65535 - (png_uint_32)(alpha)) + \
2599 32767) / 65535))
2600 #endif /* READ_COMPOSITE_NODIV */
2601
2602 #ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED
2603 PNG_EXPORT(201, png_uint_32, png_get_uint_32, (png_const_bytep buf));
2604 PNG_EXPORT(202, png_uint_16, png_get_uint_16, (png_const_bytep buf));
2605 PNG_EXPORT(203, png_int_32, png_get_int_32, (png_const_bytep buf));
2606 #endif
2607
2608 PNG_EXPORT(204, png_uint_32, png_get_uint_31, (png_const_structrp png_ptr,
2609 png_const_bytep buf));
2610 /* No png_get_int_16 -- may be added if there's a real need for it. */
2611
2612 /* Place a 32-bit number into a buffer in PNG byte order (big-endian). */
2613 #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
2614 PNG_EXPORT(205, void, png_save_uint_32, (png_bytep buf, png_uint_32 i));
2615 #endif
2616 #ifdef PNG_SAVE_INT_32_SUPPORTED
2617 PNG_EXPORT(206, void, png_save_int_32, (png_bytep buf, png_int_32 i));
2618 #endif
2619
2620 /* Place a 16-bit number into a buffer in PNG byte order.
2621 * The parameter is declared unsigned int, not png_uint_16,
2622 * just to avoid potential problems on pre-ANSI C compilers.
2623 */
2624 #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
2625 PNG_EXPORT(207, void, png_save_uint_16, (png_bytep buf, unsigned int i));
2626 /* No png_save_int_16 -- may be added if there's a real need for it. */
2627 #endif
2628
2629 #ifdef PNG_USE_READ_MACROS
2630 /* Inline macros to do direct reads of bytes from the input buffer.
2631 * The png_get_int_32() routine assumes we are using two's complement
2632 * format for negative values, which is almost certainly true.
2633 */
2634 # define PNG_get_uint_32(buf) \
2635 (((png_uint_32)(*(buf)) << 24) + \
2636 ((png_uint_32)(*((buf) + 1)) << 16) + \
2637 ((png_uint_32)(*((buf) + 2)) << 8) + \
2638 ((png_uint_32)(*((buf) + 3))))
2639
2640 /* From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the
2641 * function) incorrectly returned a value of type png_uint_32.
2642 */
2643 # define PNG_get_uint_16(buf) \
2644 ((png_uint_16) \
2645 (((unsigned int)(*(buf)) << 8) + \
2646 ((unsigned int)(*((buf) + 1)))))
2647
2648 # define PNG_get_int_32(buf) \
2649 ((png_int_32)((*(buf) & 0x80) \
2650 ? -((png_int_32)(((png_get_uint_32(buf)^0xffffffffU)+1U)&0x7fffffffU)) \
2651 : (png_int_32)png_get_uint_32(buf)))
2652
2653 /* If PNG_PREFIX is defined the same thing as below happens in pnglibconf.h,
2654 * but defining a macro name prefixed with PNG_PREFIX.
2655 */
2656 # ifndef PNG_PREFIX
2657 # define png_get_uint_32(buf) PNG_get_uint_32(buf)
2658 # define png_get_uint_16(buf) PNG_get_uint_16(buf)
2659 # define png_get_int_32(buf) PNG_get_int_32(buf)
2660 # endif
2661 #else
2662 # ifdef PNG_PREFIX
2663 /* No macros; revert to the (redefined) function */
2664 # define PNG_get_uint_32 (png_get_uint_32)
2665 # define PNG_get_uint_16 (png_get_uint_16)
2666 # define PNG_get_int_32 (png_get_int_32)
2667 # endif
2668 #endif
2669
2670 #ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
2671 PNG_EXPORT(242, void, png_set_check_for_invalid_index,
2672 (png_structrp png_ptr, int allowed));
2673 # ifdef PNG_GET_PALETTE_MAX_SUPPORTED
2674 PNG_EXPORT(243, int, png_get_palette_max, (png_const_structp png_ptr,
2675 png_const_infop info_ptr));
2676 # endif
2677 #endif /* CHECK_FOR_INVALID_INDEX */
2678
2679 /*******************************************************************************
2680 * Section 5: SIMPLIFIED API
2681 *******************************************************************************
2682 *
2683 * Please read the documentation in libpng-manual.txt (TODO: write said
2684 * documentation) if you don't understand what follows.
2685 *
2686 * The simplified API hides the details of both libpng and the PNG file format
2687 * itself. It allows PNG files to be read into a very limited number of
2688 * in-memory bitmap formats or to be written from the same formats. If these
2689 * formats do not accommodate your needs then you can, and should, use the more
2690 * sophisticated APIs above - these support a wide variety of in-memory formats
2691 * and a wide variety of sophisticated transformations to those formats as well
2692 * as a wide variety of APIs to manipulate ancillary information.
2693 *
2694 * To read a PNG file using the simplified API:
2695 *
2696 * 1) Declare a 'png_image' structure (see below) on the stack, set the
2697 * version field to PNG_IMAGE_VERSION and the 'opaque' pointer to NULL
2698 * (this is REQUIRED, your program may crash if you don't do it.)
2699 * 2) Call the appropriate png_image_begin_read... function.
2700 * 3) Set the png_image 'format' member to the required sample format.
2701 * 4) Allocate a buffer for the image and, if required, the color-map.
2702 * 5) Call png_image_finish_read to read the image and, if required, the
2703 * color-map into your buffers.
2704 *
2705 * There are no restrictions on the format of the PNG input itself; all valid
2706 * color types, bit depths, and interlace methods are acceptable, and the
2707 * input image is transformed as necessary to the requested in-memory format
2708 * during the png_image_finish_read() step. The only caveat is that if you
2709 * request a color-mapped image from a PNG that is full-color or makes
2710 * complex use of an alpha channel the transformation is extremely lossy and the
2711 * result may look terrible.
2712 *
2713 * To write a PNG file using the simplified API:
2714 *
2715 * 1) Declare a 'png_image' structure on the stack and memset() it to all zero.
2716 * 2) Initialize the members of the structure that describe the image, setting
2717 * the 'format' member to the format of the image samples.
2718 * 3) Call the appropriate png_image_write... function with a pointer to the
2719 * image and, if necessary, the color-map to write the PNG data.
2720 *
2721 * png_image is a structure that describes the in-memory format of an image
2722 * when it is being read or defines the in-memory format of an image that you
2723 * need to write:
2724 */
2725 #if defined(PNG_SIMPLIFIED_READ_SUPPORTED) || \
2726 defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
2727
2728 #define PNG_IMAGE_VERSION 1
2729
2730 typedef struct png_control *png_controlp;
2731 typedef struct
2732 {
2733 png_controlp opaque; /* Initialize to NULL, free with png_image_free */
2734 png_uint_32 version; /* Set to PNG_IMAGE_VERSION */
2735 png_uint_32 width; /* Image width in pixels (columns) */
2736 png_uint_32 height; /* Image height in pixels (rows) */
2737 png_uint_32 format; /* Image format as defined below */
2738 png_uint_32 flags; /* A bit mask containing informational flags */
2739 png_uint_32 colormap_entries;
2740 /* Number of entries in the color-map */
2741
2742 /* In the event of an error or warning the following field will be set to a
2743 * non-zero value and the 'message' field will contain a '\0' terminated
2744 * string with the libpng error or warning message. If both warnings and
2745 * an error were encountered, only the error is recorded. If there
2746 * are multiple warnings, only the first one is recorded.
2747 *
2748 * The upper 30 bits of this value are reserved, the low two bits contain
2749 * a value as follows:
2750 */
2751 # define PNG_IMAGE_WARNING 1
2752 # define PNG_IMAGE_ERROR 2
2753 /*
2754 * The result is a two-bit code such that a value more than 1 indicates
2755 * a failure in the API just called:
2756 *
2757 * 0 - no warning or error
2758 * 1 - warning
2759 * 2 - error
2760 * 3 - error preceded by warning
2761 */
2762 # define PNG_IMAGE_FAILED(png_cntrl) ((((png_cntrl).warning_or_error)&0x03)>1)
2763
2764 png_uint_32 warning_or_error;
2765
2766 char message[64];
2767 } png_image, *png_imagep;
2768
2769 /* The samples of the image have one to four channels whose components have
2770 * original values in the range 0 to 1.0:
2771 *
2772 * 1: A single gray or luminance channel (G).
2773 * 2: A gray/luminance channel and an alpha channel (GA).
2774 * 3: Three red, green, blue color channels (RGB).
2775 * 4: Three color channels and an alpha channel (RGBA).
2776 *
2777 * The components are encoded in one of two ways:
2778 *
2779 * a) As a small integer, value 0..255, contained in a single byte. For the
2780 * alpha channel the original value is simply value/255. For the color or
2781 * luminance channels the value is encoded according to the sRGB specification
2782 * and matches the 8-bit format expected by typical display devices.
2783 *
2784 * The color/gray channels are not scaled (pre-multiplied) by the alpha
2785 * channel and are suitable for passing to color management software.
2786 *
2787 * b) As a value in the range 0..65535, contained in a 2-byte integer. All
2788 * channels can be converted to the original value by dividing by 65535; all
2789 * channels are linear. Color channels use the RGB encoding (RGB end-points) of
2790 * the sRGB specification. This encoding is identified by the
2791 * PNG_FORMAT_FLAG_LINEAR flag below.
2792 *
2793 * When the simplified API needs to convert between sRGB and linear colorspaces,
2794 * the actual sRGB transfer curve defined in the sRGB specification (see the
2795 * article at https://en.wikipedia.org/wiki/SRGB) is used, not the gamma=1/2.2
2796 * approximation used elsewhere in libpng.
2797 *
2798 * When an alpha channel is present it is expected to denote pixel coverage
2799 * of the color or luminance channels and is returned as an associated alpha
2800 * channel: the color/gray channels are scaled (pre-multiplied) by the alpha
2801 * value.
2802 *
2803 * The samples are either contained directly in the image data, between 1 and 8
2804 * bytes per pixel according to the encoding, or are held in a color-map indexed
2805 * by bytes in the image data. In the case of a color-map the color-map entries
2806 * are individual samples, encoded as above, and the image data has one byte per
2807 * pixel to select the relevant sample from the color-map.
2808 */
2809
2810 /* PNG_FORMAT_*
2811 *
2812 * #defines to be used in png_image::format. Each #define identifies a
2813 * particular layout of sample data and, if present, alpha values. There are
2814 * separate defines for each of the two component encodings.
2815 *
2816 * A format is built up using single bit flag values. All combinations are
2817 * valid. Formats can be built up from the flag values or you can use one of
2818 * the predefined values below. When testing formats always use the FORMAT_FLAG
2819 * macros to test for individual features - future versions of the library may
2820 * add new flags.
2821 *
2822 * When reading or writing color-mapped images the format should be set to the
2823 * format of the entries in the color-map then png_image_{read,write}_colormap
2824 * called to read or write the color-map and set the format correctly for the
2825 * image data. Do not set the PNG_FORMAT_FLAG_COLORMAP bit directly!
2826 *
2827 * NOTE: libpng can be built with particular features disabled. If you see
2828 * compiler errors because the definition of one of the following flags has been
2829 * compiled out it is because libpng does not have the required support. It is
2830 * possible, however, for the libpng configuration to enable the format on just
2831 * read or just write; in that case you may see an error at run time. You can
2832 * guard against this by checking for the definition of the appropriate
2833 * "_SUPPORTED" macro, one of:
2834 *
2835 * PNG_SIMPLIFIED_{READ,WRITE}_{BGR,AFIRST}_SUPPORTED
2836 */
2837 #define PNG_FORMAT_FLAG_ALPHA 0x01U /* format with an alpha channel */
2838 #define PNG_FORMAT_FLAG_COLOR 0x02U /* color format: otherwise grayscale */
2839 #define PNG_FORMAT_FLAG_LINEAR 0x04U /* 2-byte channels else 1-byte */
2840 #define PNG_FORMAT_FLAG_COLORMAP 0x08U /* image data is color-mapped */
2841
2842 #ifdef PNG_FORMAT_BGR_SUPPORTED
2843 # define PNG_FORMAT_FLAG_BGR 0x10U /* BGR colors, else order is RGB */
2844 #endif
2845
2846 #ifdef PNG_FORMAT_AFIRST_SUPPORTED
2847 # define PNG_FORMAT_FLAG_AFIRST 0x20U /* alpha channel comes first */
2848 #endif
2849
2850 #define PNG_FORMAT_FLAG_ASSOCIATED_ALPHA 0x40U /* alpha channel is associated */
2851
2852 /* Commonly used formats have predefined macros.
2853 *
2854 * First the single byte (sRGB) formats:
2855 */
2856 #define PNG_FORMAT_GRAY 0
2857 #define PNG_FORMAT_GA PNG_FORMAT_FLAG_ALPHA
2858 #define PNG_FORMAT_AG (PNG_FORMAT_GA|PNG_FORMAT_FLAG_AFIRST)
2859 #define PNG_FORMAT_RGB PNG_FORMAT_FLAG_COLOR
2860 #define PNG_FORMAT_BGR (PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_BGR)
2861 #define PNG_FORMAT_RGBA (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_ALPHA)
2862 #define PNG_FORMAT_ARGB (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_AFIRST)
2863 #define PNG_FORMAT_BGRA (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_ALPHA)
2864 #define PNG_FORMAT_ABGR (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_AFIRST)
2865
2866 /* Then the linear 2-byte formats. When naming these "Y" is used to
2867 * indicate a luminance (gray) channel.
2868 */
2869 #define PNG_FORMAT_LINEAR_Y PNG_FORMAT_FLAG_LINEAR
2870 #define PNG_FORMAT_LINEAR_Y_ALPHA (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_ALPHA)
2871 #define PNG_FORMAT_LINEAR_RGB (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR)
2872 #define PNG_FORMAT_LINEAR_RGB_ALPHA \
2873 (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA)
2874
2875 /* With color-mapped formats the image data is one byte for each pixel, the byte
2876 * is an index into the color-map which is formatted as above. To obtain a
2877 * color-mapped format it is sufficient just to add the PNG_FOMAT_FLAG_COLORMAP
2878 * to one of the above definitions, or you can use one of the definitions below.
2879 */
2880 #define PNG_FORMAT_RGB_COLORMAP (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_COLORMAP)
2881 #define PNG_FORMAT_BGR_COLORMAP (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_COLORMAP)
2882 #define PNG_FORMAT_RGBA_COLORMAP (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_COLORMAP)
2883 #define PNG_FORMAT_ARGB_COLORMAP (PNG_FORMAT_ARGB|PNG_FORMAT_FLAG_COLORMAP)
2884 #define PNG_FORMAT_BGRA_COLORMAP (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_COLORMAP)
2885 #define PNG_FORMAT_ABGR_COLORMAP (PNG_FORMAT_ABGR|PNG_FORMAT_FLAG_COLORMAP)
2886
2887 /* PNG_IMAGE macros
2888 *
2889 * These are convenience macros to derive information from a png_image
2890 * structure. The PNG_IMAGE_SAMPLE_ macros return values appropriate to the
2891 * actual image sample values - either the entries in the color-map or the
2892 * pixels in the image. The PNG_IMAGE_PIXEL_ macros return corresponding values
2893 * for the pixels and will always return 1 for color-mapped formats. The
2894 * remaining macros return information about the rows in the image and the
2895 * complete image.
2896 *
2897 * NOTE: All the macros that take a png_image::format parameter are compile time
2898 * constants if the format parameter is, itself, a constant. Therefore these
2899 * macros can be used in array declarations and case labels where required.
2900 * Similarly the macros are also pre-processor constants (sizeof is not used) so
2901 * they can be used in #if tests.
2902 *
2903 * First the information about the samples.
2904 */
2905 #define PNG_IMAGE_SAMPLE_CHANNELS(fmt)\
2906 (((fmt)&(PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA))+1)
2907 /* Return the total number of channels in a given format: 1..4 */
2908
2909 #define PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)\
2910 ((((fmt) & PNG_FORMAT_FLAG_LINEAR) >> 2)+1)
2911 /* Return the size in bytes of a single component of a pixel or color-map
2912 * entry (as appropriate) in the image: 1 or 2.
2913 */
2914
2915 #define PNG_IMAGE_SAMPLE_SIZE(fmt)\
2916 (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt))
2917 /* This is the size of the sample data for one sample. If the image is
2918 * color-mapped it is the size of one color-map entry (and image pixels are
2919 * one byte in size), otherwise it is the size of one image pixel.
2920 */
2921
2922 #define PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(fmt)\
2923 (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * 256)
2924 /* The maximum size of the color-map required by the format expressed in a
2925 * count of components. This can be used to compile-time allocate a
2926 * color-map:
2927 *
2928 * png_uint_16 colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(linear_fmt)];
2929 *
2930 * png_byte colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(sRGB_fmt)];
2931 *
2932 * Alternatively use the PNG_IMAGE_COLORMAP_SIZE macro below to use the
2933 * information from one of the png_image_begin_read_ APIs and dynamically
2934 * allocate the required memory.
2935 */
2936
2937 /* Corresponding information about the pixels */
2938 #define PNG_IMAGE_PIXEL_(test,fmt)\
2939 (((fmt)&PNG_FORMAT_FLAG_COLORMAP)?1:test(fmt))
2940
2941 #define PNG_IMAGE_PIXEL_CHANNELS(fmt)\
2942 PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_CHANNELS,fmt)
2943 /* The number of separate channels (components) in a pixel; 1 for a
2944 * color-mapped image.
2945 */
2946
2947 #define PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt)\
2948 PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_COMPONENT_SIZE,fmt)
2949 /* The size, in bytes, of each component in a pixel; 1 for a color-mapped
2950 * image.
2951 */
2952
2953 #define PNG_IMAGE_PIXEL_SIZE(fmt) PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_SIZE,fmt)
2954 /* The size, in bytes, of a complete pixel; 1 for a color-mapped image. */
2955
2956 /* Information about the whole row, or whole image */
2957 #define PNG_IMAGE_ROW_STRIDE(image)\
2958 (PNG_IMAGE_PIXEL_CHANNELS((image).format) * (image).width)
2959 /* Return the total number of components in a single row of the image; this
2960 * is the minimum 'row stride', the minimum count of components between each
2961 * row. For a color-mapped image this is the minimum number of bytes in a
2962 * row.
2963 *
2964 * WARNING: this macro overflows for some images with more than one component
2965 * and very large image widths. libpng will refuse to process an image where
2966 * this macro would overflow.
2967 */
2968
2969 #define PNG_IMAGE_BUFFER_SIZE(image, row_stride)\
2970 (PNG_IMAGE_PIXEL_COMPONENT_SIZE((image).format)*(image).height*(row_stride))
2971 /* Return the size, in bytes, of an image buffer given a png_image and a row
2972 * stride - the number of components to leave space for in each row.
2973 *
2974 * WARNING: this macro overflows a 32-bit integer for some large PNG images,
2975 * libpng will refuse to process an image where such an overflow would occur.
2976 */
2977
2978 #define PNG_IMAGE_SIZE(image)\
2979 PNG_IMAGE_BUFFER_SIZE(image, PNG_IMAGE_ROW_STRIDE(image))
2980 /* Return the size, in bytes, of the image in memory given just a png_image;
2981 * the row stride is the minimum stride required for the image.
2982 */
2983
2984 #define PNG_IMAGE_COLORMAP_SIZE(image)\
2985 (PNG_IMAGE_SAMPLE_SIZE((image).format) * (image).colormap_entries)
2986 /* Return the size, in bytes, of the color-map of this image. If the image
2987 * format is not a color-map format this will return a size sufficient for
2988 * 256 entries in the given format; check PNG_FORMAT_FLAG_COLORMAP if
2989 * you don't want to allocate a color-map in this case.
2990 */
2991
2992 /* PNG_IMAGE_FLAG_*
2993 *
2994 * Flags containing additional information about the image are held in the
2995 * 'flags' field of png_image.
2996 */
2997 #define PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB 0x01
2998 /* This indicates the the RGB values of the in-memory bitmap do not
2999 * correspond to the red, green and blue end-points defined by sRGB.
3000 */
3001
3002 #define PNG_IMAGE_FLAG_FAST 0x02
3003 /* On write emphasise speed over compression; the resultant PNG file will be
3004 * larger but will be produced significantly faster, particular for large
3005 * images. Do not use this option for images which will be distributed, only
3006 * used it when producing intermediate files that will be read back in
3007 * repeatedly. For a typical 24-bit image the option will double the read
3008 * speed at the cost of increasing the image size by 25%, however for many
3009 * more compressible images the PNG file can be 10 times larger with only a
3010 * slight speed gain.
3011 */
3012
3013 #define PNG_IMAGE_FLAG_16BIT_sRGB 0x04
3014 /* On read if the image is a 16-bit per component image and there is no gAMA
3015 * or sRGB chunk assume that the components are sRGB encoded. Notice that
3016 * images output by the simplified API always have gamma information; setting
3017 * this flag only affects the interpretation of 16-bit images from an
3018 * external source. It is recommended that the application expose this flag
3019 * to the user; the user can normally easily recognize the difference between
3020 * linear and sRGB encoding. This flag has no effect on write - the data
3021 * passed to the write APIs must have the correct encoding (as defined
3022 * above.)
3023 *
3024 * If the flag is not set (the default) input 16-bit per component data is
3025 * assumed to be linear.
3026 *
3027 * NOTE: the flag can only be set after the png_image_begin_read_ call,
3028 * because that call initializes the 'flags' field.
3029 */
3030
3031 #ifdef PNG_SIMPLIFIED_READ_SUPPORTED
3032 /* READ APIs
3033 * ---------
3034 *
3035 * The png_image passed to the read APIs must have been initialized by setting
3036 * the png_controlp field 'opaque' to NULL (or, safer, memset the whole thing.)
3037 */
3038 #ifdef PNG_STDIO_SUPPORTED
3039 PNG_EXPORT(234, int, png_image_begin_read_from_file, (png_imagep image,
3040 const char *file_name));
3041 /* The named file is opened for read and the image header is filled in
3042 * from the PNG header in the file.
3043 */
3044
3045 PNG_EXPORT(235, int, png_image_begin_read_from_stdio, (png_imagep image,
3046 FILE* file));
3047 /* The PNG header is read from the stdio FILE object. */
3048 #endif /* STDIO */
3049
3050 PNG_EXPORT(236, int, png_image_begin_read_from_memory, (png_imagep image,
3051 png_const_voidp memory, size_t size));
3052 /* The PNG header is read from the given memory buffer. */
3053
3054 PNG_EXPORT(237, int, png_image_finish_read, (png_imagep image,
3055 png_const_colorp background, void *buffer, png_int_32 row_stride,
3056 void *colormap));
3057 /* Finish reading the image into the supplied buffer and clean up the
3058 * png_image structure.
3059 *
3060 * row_stride is the step, in byte or 2-byte units as appropriate,
3061 * between adjacent rows. A positive stride indicates that the top-most row
3062 * is first in the buffer - the normal top-down arrangement. A negative
3063 * stride indicates that the bottom-most row is first in the buffer.
3064 *
3065 * background need only be supplied if an alpha channel must be removed from
3066 * a png_byte format and the removal is to be done by compositing on a solid
3067 * color; otherwise it may be NULL and any composition will be done directly
3068 * onto the buffer. The value is an sRGB color to use for the background,
3069 * for grayscale output the green channel is used.
3070 *
3071 * background must be supplied when an alpha channel must be removed from a
3072 * single byte color-mapped output format, in other words if:
3073 *
3074 * 1) The original format from png_image_begin_read_from_* had
3075 * PNG_FORMAT_FLAG_ALPHA set.
3076 * 2) The format set by the application does not.
3077 * 3) The format set by the application has PNG_FORMAT_FLAG_COLORMAP set and
3078 * PNG_FORMAT_FLAG_LINEAR *not* set.
3079 *
3080 * For linear output removing the alpha channel is always done by compositing
3081 * on black and background is ignored.
3082 *
3083 * colormap must be supplied when PNG_FORMAT_FLAG_COLORMAP is set. It must
3084 * be at least the size (in bytes) returned by PNG_IMAGE_COLORMAP_SIZE.
3085 * image->colormap_entries will be updated to the actual number of entries
3086 * written to the colormap; this may be less than the original value.
3087 */
3088
3089 PNG_EXPORT(238, void, png_image_free, (png_imagep image));
3090 /* Free any data allocated by libpng in image->opaque, setting the pointer to
3091 * NULL. May be called at any time after the structure is initialized.
3092 */
3093 #endif /* SIMPLIFIED_READ */
3094
3095 #ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED
3096 /* WRITE APIS
3097 * ----------
3098 * For write you must initialize a png_image structure to describe the image to
3099 * be written. To do this use memset to set the whole structure to 0 then
3100 * initialize fields describing your image.
3101 *
3102 * version: must be set to PNG_IMAGE_VERSION
3103 * opaque: must be initialized to NULL
3104 * width: image width in pixels
3105 * height: image height in rows
3106 * format: the format of the data (image and color-map) you wish to write
3107 * flags: set to 0 unless one of the defined flags applies; set
3108 * PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB for color format images where the RGB
3109 * values do not correspond to the colors in sRGB.
3110 * colormap_entries: set to the number of entries in the color-map (0 to 256)
3111 */
3112 #ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED
3113 PNG_EXPORT(239, int, png_image_write_to_file, (png_imagep image,
3114 const char *file, int convert_to_8bit, const void *buffer,
3115 png_int_32 row_stride, const void *colormap));
3116 /* Write the image to the named file. */
3117
3118 PNG_EXPORT(240, int, png_image_write_to_stdio, (png_imagep image, FILE *file,
3119 int convert_to_8_bit, const void *buffer, png_int_32 row_stride,
3120 const void *colormap));
3121 /* Write the image to the given (FILE*). */
3122 #endif /* SIMPLIFIED_WRITE_STDIO */
3123
3124 /* With all write APIs if image is in one of the linear formats with 16-bit
3125 * data then setting convert_to_8_bit will cause the output to be an 8-bit PNG
3126 * gamma encoded according to the sRGB specification, otherwise a 16-bit linear
3127 * encoded PNG file is written.
3128 *
3129 * With color-mapped data formats the colormap parameter point to a color-map
3130 * with at least image->colormap_entries encoded in the specified format. If
3131 * the format is linear the written PNG color-map will be converted to sRGB
3132 * regardless of the convert_to_8_bit flag.
3133 *
3134 * With all APIs row_stride is handled as in the read APIs - it is the spacing
3135 * from one row to the next in component sized units (1 or 2 bytes) and if
3136 * negative indicates a bottom-up row layout in the buffer. If row_stride is
3137 * zero, libpng will calculate it for you from the image width and number of
3138 * channels.
3139 *
3140 * Note that the write API does not support interlacing, sub-8-bit pixels or
3141 * most ancillary chunks. If you need to write text chunks (e.g. for copyright
3142 * notices) you need to use one of the other APIs.
3143 */
3144
3145 PNG_EXPORT(245, int, png_image_write_to_memory, (png_imagep image, void *memory,
3146 png_alloc_size_t * PNG_RESTRICT memory_bytes, int convert_to_8_bit,
3147 const void *buffer, png_int_32 row_stride, const void *colormap));
3148 /* Write the image to the given memory buffer. The function both writes the
3149 * whole PNG data stream to *memory and updates *memory_bytes with the count
3150 * of bytes written.
3151 *
3152 * 'memory' may be NULL. In this case *memory_bytes is not read however on
3153 * success the number of bytes which would have been written will still be
3154 * stored in *memory_bytes. On failure *memory_bytes will contain 0.
3155 *
3156 * If 'memory' is not NULL it must point to memory[*memory_bytes] of
3157 * writeable memory.
3158 *
3159 * If the function returns success memory[*memory_bytes] (if 'memory' is not
3160 * NULL) contains the written PNG data. *memory_bytes will always be less
3161 * than or equal to the original value.
3162 *
3163 * If the function returns false and *memory_bytes was not changed an error
3164 * occurred during write. If *memory_bytes was changed, or is not 0 if
3165 * 'memory' was NULL, the write would have succeeded but for the memory
3166 * buffer being too small. *memory_bytes contains the required number of
3167 * bytes and will be bigger that the original value.
3168 */
3169
3170 #define png_image_write_get_memory_size(image, size, convert_to_8_bit, buffer,\
3171 row_stride, colormap)\
3172 png_image_write_to_memory(&(image), 0, &(size), convert_to_8_bit, buffer,\
3173 row_stride, colormap)
3174 /* Return the amount of memory in 'size' required to compress this image.
3175 * The png_image structure 'image' must be filled in as in the above
3176 * function and must not be changed before the actual write call, the buffer
3177 * and all other parameters must also be identical to that in the final
3178 * write call. The 'size' variable need not be initialized.
3179 *
3180 * NOTE: the macro returns true/false, if false is returned 'size' will be
3181 * set to zero and the write failed and probably will fail if tried again.
3182 */
3183
3184 /* You can pre-allocate the buffer by making sure it is of sufficient size
3185 * regardless of the amount of compression achieved. The buffer size will
3186 * always be bigger than the original image and it will never be filled. The
3187 * following macros are provided to assist in allocating the buffer.
3188 */
3189 #define PNG_IMAGE_DATA_SIZE(image) (PNG_IMAGE_SIZE(image)+(image).height)
3190 /* The number of uncompressed bytes in the PNG byte encoding of the image;
3191 * uncompressing the PNG IDAT data will give this number of bytes.
3192 *
3193 * NOTE: while PNG_IMAGE_SIZE cannot overflow for an image in memory this
3194 * macro can because of the extra bytes used in the PNG byte encoding. You
3195 * need to avoid this macro if your image size approaches 2^30 in width or
3196 * height. The same goes for the remainder of these macros; they all produce
3197 * bigger numbers than the actual in-memory image size.
3198 */
3199 #ifndef PNG_ZLIB_MAX_SIZE
3200 # define PNG_ZLIB_MAX_SIZE(b) ((b)+(((b)+7U)>>3)+(((b)+63U)>>6)+11U)
3201 /* An upper bound on the number of compressed bytes given 'b' uncompressed
3202 * bytes. This is based on deflateBounds() in zlib; different
3203 * implementations of zlib compression may conceivably produce more data so
3204 * if your zlib implementation is not zlib itself redefine this macro
3205 * appropriately.
3206 */
3207 #endif
3208
3209 #define PNG_IMAGE_COMPRESSED_SIZE_MAX(image)\
3210 PNG_ZLIB_MAX_SIZE((png_alloc_size_t)PNG_IMAGE_DATA_SIZE(image))
3211 /* An upper bound on the size of the data in the PNG IDAT chunks. */
3212
3213 #define PNG_IMAGE_PNG_SIZE_MAX_(image, image_size)\
3214 ((8U/*sig*/+25U/*IHDR*/+16U/*gAMA*/+44U/*cHRM*/+12U/*IEND*/+\
3215 (((image).format&PNG_FORMAT_FLAG_COLORMAP)?/*colormap: PLTE, tRNS*/\
3216 12U+3U*(image).colormap_entries/*PLTE data*/+\
3217 (((image).format&PNG_FORMAT_FLAG_ALPHA)?\
3218 12U/*tRNS*/+(image).colormap_entries:0U):0U)+\
3219 12U)+(12U*((image_size)/PNG_ZBUF_SIZE))/*IDAT*/+(image_size))
3220 /* A helper for the following macro; if your compiler cannot handle the
3221 * following macro use this one with the result of
3222 * PNG_IMAGE_COMPRESSED_SIZE_MAX(image) as the second argument (most
3223 * compilers should handle this just fine.)
3224 */
3225
3226 #define PNG_IMAGE_PNG_SIZE_MAX(image)\
3227 PNG_IMAGE_PNG_SIZE_MAX_(image, PNG_IMAGE_COMPRESSED_SIZE_MAX(image))
3228 /* An upper bound on the total length of the PNG data stream for 'image'.
3229 * The result is of type png_alloc_size_t, on 32-bit systems this may
3230 * overflow even though PNG_IMAGE_DATA_SIZE does not overflow; the write will
3231 * run out of buffer space but return a corrected size which should work.
3232 */
3233 #endif /* SIMPLIFIED_WRITE */
3234 /*******************************************************************************
3235 * END OF SIMPLIFIED API
3236 ******************************************************************************/
3237 #endif /* SIMPLIFIED_{READ|WRITE} */
3238
3239 /*******************************************************************************
3240 * Section 6: IMPLEMENTATION OPTIONS
3241 *******************************************************************************
3242 *
3243 * Support for arbitrary implementation-specific optimizations. The API allows
3244 * particular options to be turned on or off. 'Option' is the number of the
3245 * option and 'onoff' is 0 (off) or non-0 (on). The value returned is given
3246 * by the PNG_OPTION_ defines below.
3247 *
3248 * HARDWARE: normally hardware capabilities, such as the Intel SSE instructions,
3249 * are detected at run time, however sometimes it may be impossible
3250 * to do this in user mode, in which case it is necessary to discover
3251 * the capabilities in an OS specific way. Such capabilities are
3252 * listed here when libpng has support for them and must be turned
3253 * ON by the application if present.
3254 *
3255 * SOFTWARE: sometimes software optimizations actually result in performance
3256 * decrease on some architectures or systems, or with some sets of
3257 * PNG images. 'Software' options allow such optimizations to be
3258 * selected at run time.
3259 */
3260 #ifdef PNG_SET_OPTION_SUPPORTED
3261 #ifdef PNG_ARM_NEON_API_SUPPORTED
3262 # define PNG_ARM_NEON 0 /* HARDWARE: ARM Neon SIMD instructions supported */
3263 #endif
3264 #define PNG_MAXIMUM_INFLATE_WINDOW 2 /* SOFTWARE: force maximum window */
3265 #define PNG_SKIP_sRGB_CHECK_PROFILE 4 /* SOFTWARE: Check ICC profile for sRGB */
3266 #ifdef PNG_MIPS_MSA_API_SUPPORTED
3267 # define PNG_MIPS_MSA 6 /* HARDWARE: MIPS Msa SIMD instructions supported */
3268 #endif
3269 #define PNG_IGNORE_ADLER32 8
3270 #ifdef PNG_POWERPC_VSX_API_SUPPORTED
3271 # define PNG_POWERPC_VSX 10 /* HARDWARE: PowerPC VSX SIMD instructions supported */
3272 #endif
3273 #define PNG_OPTION_NEXT 12 /* Next option - numbers must be even */
3274
3275 /* Return values: NOTE: there are four values and 'off' is *not* zero */
3276 #define PNG_OPTION_UNSET 0 /* Unset - defaults to off */
3277 #define PNG_OPTION_INVALID 1 /* Option number out of range */
3278 #define PNG_OPTION_OFF 2
3279 #define PNG_OPTION_ON 3
3280
3281 PNG_EXPORT(244, int, png_set_option, (png_structrp png_ptr, int option,
3282 int onoff));
3283 #endif /* SET_OPTION */
3284
3285 /*******************************************************************************
3286 * END OF HARDWARE AND SOFTWARE OPTIONS
3287 ******************************************************************************/
3288
3289 /* Maintainer: Put new public prototypes here ^, in libpng.3, in project
3290 * defs, and in scripts/symbols.def.
3291 */
3292
3293 /* The last ordinal number (this is the *last* one already used; the next
3294 * one to use is one more than this.)
3295 */
3296 #ifdef PNG_EXPORT_LAST_ORDINAL
3297 PNG_EXPORT_LAST_ORDINAL(249);
3298 #endif
3299
3300 #ifdef __cplusplus
3301 }
3302 #endif
3303
3304 #endif /* PNG_VERSION_INFO_ONLY */
3305 /* Do not put anything past this line */
3306 #endif /* PNG_H */