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 1.6.28, January 5, 2017
33 *
34 * Copyright (c) 1998-2002,2004,2006-2017 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 1.6.28, January 5, 2017:
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 1.6.28, January 5, 2017 are
57 * Copyright (c) 2000-2002, 2004, 2006-2017 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 *
70 * and with the following additions to the disclaimer:
71 *
72 * There is no warranty against interference with your enjoyment of the
73 * library or against infringement. There is no warranty that our
74 * efforts or the library will fulfill any of your particular purposes
75 * or needs. This library is provided with all faults, and the entire
76 * risk of satisfactory quality, performance, accuracy, and effort is with
77 * the user.
78 *
79 * Some files in the "contrib" directory and some configure-generated
80 * files that are distributed with libpng have other copyright owners and
81 * are released under other open source licenses.
82 *
83 * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
84 * Copyright (c) 1998-2000 Glenn Randers-Pehrson, are derived from
85 * libpng-0.96, and are distributed according to the same disclaimer and
86 * license as libpng-0.96, with the following individuals added to the list
87 * of Contributing Authors:
88 *
89 * Tom Lane
90 * Glenn Randers-Pehrson
91 * Willem van Schaik
92 *
93 * libpng versions 0.89, June 1996, through 0.96, May 1997, are
94 * Copyright (c) 1996-1997 Andreas Dilger, are derived from libpng-0.88,
95 * and are distributed according to the same disclaimer and license as
96 * libpng-0.88, with the following individuals added to the list of
97 * Contributing Authors:
98 *
99 * John Bowler
100 * Kevin Bracey
101 * Sam Bushell
102 * Magnus Holmgren
103 * Greg Roelofs
104 * Tom Tanner
105 *
106 * Some files in the "scripts" directory have other copyright owners
107 * but are released under this license.
108 *
109 * libpng versions 0.5, May 1995, through 0.88, January 1996, are
110 * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
111 *
112 * For the purposes of this copyright and license, "Contributing Authors"
113 * is defined as the following set of individuals:
114 *
115 * Andreas Dilger
116 * Dave Martindale
117 * Guy Eric Schalnat
118 * Paul Schmidt
119 * Tim Wegner
120 *
121 * The PNG Reference Library is supplied "AS IS". The Contributing Authors
122 * and Group 42, Inc. disclaim all warranties, expressed or implied,
123 * including, without limitation, the warranties of merchantability and of
124 * fitness for any purpose. The Contributing Authors and Group 42, Inc.
125 * assume no liability for direct, indirect, incidental, special, exemplary,
126 * or consequential damages, which may result from the use of the PNG
127 * Reference Library, even if advised of the possibility of such damage.
128 *
129 * Permission is hereby granted to use, copy, modify, and distribute this
130 * source code, or portions hereof, for any purpose, without fee, subject
131 * to the following restrictions:
132 *
133 * 1. The origin of this source code must not be misrepresented.
134 *
135 * 2. Altered versions must be plainly marked as such and must not
136 * be misrepresented as being the original source.
137 *
138 * 3. This Copyright notice may not be removed or altered from any
139 * source or altered source distribution.
140 *
141 * The Contributing Authors and Group 42, Inc. specifically permit, without
142 * fee, and encourage the use of this source code as a component to
143 * supporting the PNG file format in commercial products. If you use this
144 * source code in a product, acknowledgment is not required but would be
145 * appreciated.
146 *
147 * END OF COPYRIGHT NOTICE, DISCLAIMER, and LICENSE.
148 *
149 * TRADEMARK:
150 *
151 * The name "libpng" has not been registered by the Copyright owner
152 * as a trademark in any jurisdiction. However, because libpng has
153 * been distributed and maintained world-wide, continually since 1995,
154 * the Copyright owner claims "common-law trademark protection" in any
155 * jurisdiction where common-law trademark is recognized.
156 *
157 * OSI CERTIFICATION:
158 *
159 * Libpng is OSI Certified Open Source Software. OSI Certified Open Source is
160 * a certification mark of the Open Source Initiative. OSI has not addressed
161 * the additional disclaimers inserted at version 1.0.7.
162 *
163 * EXPORT CONTROL:
164 *
165 * The Copyright owner believes that the Export Control Classification
166 * Number (ECCN) for libpng is EAR99, which means not subject to export
167 * controls or International Traffic in Arms Regulations (ITAR) because
168 * it is open source, publicly available software, that does not contain
169 * any encryption software. See the EAR, paragraphs 734.3(b)(3) and
170 * 734.7(b).
171 */
172
173 /*
174 * A "png_get_copyright" function is available, for convenient use in "about"
175 * boxes and the like:
176 *
177 * printf("%s", png_get_copyright(NULL));
178 *
179 * Also, the PNG logo (in PNG format, of course) is supplied in the
180 * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
181 */
182
183 /*
184 * The contributing authors would like to thank all those who helped
185 * with testing, bug fixes, and patience. This wouldn't have been
186 * possible without all of you.
187 *
188 * Thanks to Frank J. T. Wojcik for helping with the documentation.
189 */
190
191 /* Note about libpng version numbers:
192 *
193 * Due to various miscommunications, unforeseen code incompatibilities
194 * and occasional factors outside the authors' control, version numbering
195 * on the library has not always been consistent and straightforward.
196 * The following table summarizes matters since version 0.89c, which was
197 * the first widely used release:
198 *
199 * source png.h png.h shared-lib
200 * version string int version
201 * ------- ------ ----- ----------
202 * 0.89c "1.0 beta 3" 0.89 89 1.0.89
203 * 0.90 "1.0 beta 4" 0.90 90 0.90 [should have been 2.0.90]
204 * 0.95 "1.0 beta 5" 0.95 95 0.95 [should have been 2.0.95]
205 * 0.96 "1.0 beta 6" 0.96 96 0.96 [should have been 2.0.96]
206 * 0.97b "1.00.97 beta 7" 1.00.97 97 1.0.1 [should have been 2.0.97]
207 * 0.97c 0.97 97 2.0.97
208 * 0.98 0.98 98 2.0.98
209 * 0.99 0.99 98 2.0.99
210 * 0.99a-m 0.99 99 2.0.99
211 * 1.00 1.00 100 2.1.0 [100 should be 10000]
212 * 1.0.0 (from here on, the 100 2.1.0 [100 should be 10000]
213 * 1.0.1 png.h string is 10001 2.1.0
214 * 1.0.1a-e identical to the 10002 from here on, the shared library
215 * 1.0.2 source version) 10002 is 2.V where V is the source code
216 * 1.0.2a-b 10003 version, except as noted.
217 * 1.0.3 10003
218 * 1.0.3a-d 10004
219 * 1.0.4 10004
220 * 1.0.4a-f 10005
221 * 1.0.5 (+ 2 patches) 10005
222 * 1.0.5a-d 10006
223 * 1.0.5e-r 10100 (not source compatible)
224 * 1.0.5s-v 10006 (not binary compatible)
225 * 1.0.6 (+ 3 patches) 10006 (still binary incompatible)
226 * 1.0.6d-f 10007 (still binary incompatible)
227 * 1.0.6g 10007
228 * 1.0.6h 10007 10.6h (testing xy.z so-numbering)
229 * 1.0.6i 10007 10.6i
230 * 1.0.6j 10007 2.1.0.6j (incompatible with 1.0.0)
231 * 1.0.7beta11-14 DLLNUM 10007 2.1.0.7beta11-14 (binary compatible)
232 * 1.0.7beta15-18 1 10007 2.1.0.7beta15-18 (binary compatible)
233 * 1.0.7rc1-2 1 10007 2.1.0.7rc1-2 (binary compatible)
234 * 1.0.7 1 10007 (still compatible)
235 * ...
236 * 1.0.19 10 10019 10.so.0.19[.0]
237 * ...
238 * 1.2.57 13 10257 12.so.0.57[.0]
239 * ...
240 * 1.5.28 15 10527 15.so.15.28[.0]
241 * ...
242 * 1.6.28 16 10628 16.so.16.28[.0]
243 *
244 * Henceforth the source version will match the shared-library major
245 * and minor numbers; the shared-library major version number will be
246 * used for changes in backward compatibility, as it is intended. The
247 * PNG_LIBPNG_VER macro, which is not used within libpng but is available
248 * for applications, is an unsigned integer of the form xyyzz corresponding
249 * to the source version x.y.z (leading zeros in y and z). Beta versions
250 * were given the previous public release number plus a letter, until
251 * version 1.0.6j; from then on they were given the upcoming public
252 * release number plus "betaNN" or "rcNN".
253 *
254 * Binary incompatibility exists only when applications make direct access
255 * to the info_ptr or png_ptr members through png.h, and the compiled
256 * application is loaded with a different version of the library.
257 *
258 * DLLNUM will change each time there are forward or backward changes
259 * in binary compatibility (e.g., when a new feature is added).
260 *
261 * See libpng.txt or libpng.3 for more information. The PNG specification
262 * is available as a W3C Recommendation and as an ISO Specification,
263 * <http://www.w3.org/TR/2003/REC-PNG-20031110/
264 */
265
266 /*
267 * Y2K compliance in libpng:
268 * =========================
269 *
270 * January 5, 2017
271 *
272 * Since the PNG Development group is an ad-hoc body, we can't make
273 * an official declaration.
274 *
275 * This is your unofficial assurance that libpng from version 0.71 and
276 * upward through 1.6.28 are Y2K compliant. It is my belief that
277 * earlier versions were also Y2K compliant.
278 *
279 * Libpng only has two year fields. One is a 2-byte unsigned integer
280 * that will hold years up to 65535. The other, which is deprecated,
281 * holds the date in text format, and will hold years up to 9999.
282 *
283 * The integer is
284 * "png_uint_16 year" in png_time_struct.
285 *
286 * The string is
287 * "char time_buffer[29]" in png_struct. This is no longer used
288 * in libpng-1.6.x and will be removed from libpng-1.7.0.
289 *
290 * There are seven time-related functions:
291 * png.c: png_convert_to_rfc_1123_buffer() in png.c
292 * (formerly png_convert_to_rfc_1123() prior to libpng-1.5.x and
293 * png_convert_to_rfc_1152() in error prior to libpng-0.98)
294 * png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
295 * png_convert_from_time_t() in pngwrite.c
296 * png_get_tIME() in pngget.c
297 * png_handle_tIME() in pngrutil.c, called in pngread.c
298 * png_set_tIME() in pngset.c
299 * png_write_tIME() in pngwutil.c, called in pngwrite.c
300 *
301 * All handle dates properly in a Y2K environment. The
302 * png_convert_from_time_t() function calls gmtime() to convert from system
303 * clock time, which returns (year - 1900), which we properly convert to
304 * the full 4-digit year. There is a possibility that libpng applications
305 * are not passing 4-digit years into the png_convert_to_rfc_1123_buffer()
306 * function, or that they are incorrectly passing only a 2-digit year
307 * instead of "year - 1900" into the png_convert_from_struct_tm() function,
308 * but this is not under our control. The libpng documentation has always
309 * stated that it works with 4-digit years, and the APIs have been
310 * documented as such.
311 *
312 * The tIME chunk itself is also Y2K compliant. It uses a 2-byte unsigned
313 * integer to hold the year, and can hold years as large as 65535.
314 *
315 * zlib, upon which libpng depends, is also Y2K compliant. It contains
316 * no date-related code.
317 *
318 * Glenn Randers-Pehrson
319 * libpng maintainer
320 * PNG Development Group
321 */
322
323 #ifndef PNG_H
324 #define PNG_H
325
326 /* This is not the place to learn how to use libpng. The file libpng-manual.txt
327 * describes how to use libpng, and the file example.c summarizes it
328 * with some code on which to build. This file is useful for looking
329 * at the actual function definitions and structure components. If that
330 * file has been stripped from your copy of libpng, you can find it at
331 * <http://www.libpng.org/pub/png/libpng-manual.txt>
332 *
333 * If you just need to read a PNG file and don't want to read the documentation
334 * skip to the end of this file and read the section entitled 'simplified API'.
335 */
336
337 /* Version information for png.h - this should match the version in png.c */
338 #define PNG_LIBPNG_VER_STRING "1.6.28"
339 #define PNG_HEADER_VERSION_STRING " libpng version 1.6.28 - January 5, 2017\n"
340
341 #define PNG_LIBPNG_VER_SONUM 16
342 #define PNG_LIBPNG_VER_DLLNUM 16
343
344 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
345 #define PNG_LIBPNG_VER_MAJOR 1
346 #define PNG_LIBPNG_VER_MINOR 6
347 #define PNG_LIBPNG_VER_RELEASE 28
348
349 /* This should match the numeric part of the final component of
350 * PNG_LIBPNG_VER_STRING, omitting any leading zero:
351 */
352
353 #define PNG_LIBPNG_VER_BUILD 0
354
355 /* Release Status */
356 #define PNG_LIBPNG_BUILD_ALPHA 1
357 #define PNG_LIBPNG_BUILD_BETA 2
358 #define PNG_LIBPNG_BUILD_RC 3
359 #define PNG_LIBPNG_BUILD_STABLE 4
360 #define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7
361
362 /* Release-Specific Flags */
363 #define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with
364 PNG_LIBPNG_BUILD_STABLE only */
365 #define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with
366 PNG_LIBPNG_BUILD_SPECIAL */
367 #define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with
368 PNG_LIBPNG_BUILD_PRIVATE */
369
370 #define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE
371
372 /* Careful here. At one time, Guy wanted to use 082, but that would be octal.
373 * We must not include leading zeros.
374 * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only
375 * version 1.0.0 was mis-numbered 100 instead of 10000). From
376 * version 1.0.1 it's xxyyzz, where x=major, y=minor, z=release
377 */
378 #define PNG_LIBPNG_VER 10628 /* 1.6.28 */
379
380 /* Library configuration: these options cannot be changed after
381 * the library has been built.
382 */
383 #ifndef PNGLCONF_H
384 /* If pnglibconf.h is missing, you can
385 * copy scripts/pnglibconf.h.prebuilt to pnglibconf.h
386 */
387 # include "pnglibconf.h"
388 #endif
389
390 #ifndef PNG_VERSION_INFO_ONLY
391 /* Machine specific configuration. */
392 # include "pngconf.h"
393 #endif
394
395 /*
396 * Added at libpng-1.2.8
397 *
398 * Ref MSDN: Private as priority over Special
399 * VS_FF_PRIVATEBUILD File *was not* built using standard release
400 * procedures. If this value is given, the StringFileInfo block must
401 * contain a PrivateBuild string.
402 *
403 * VS_FF_SPECIALBUILD File *was* built by the original company using
404 * standard release procedures but is a variation of the standard
405 * file of the same version number. If this value is given, the
406 * StringFileInfo block must contain a SpecialBuild string.
407 */
408
409 #ifdef PNG_USER_PRIVATEBUILD /* From pnglibconf.h */
410 # define PNG_LIBPNG_BUILD_TYPE \
411 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE)
412 #else
413 # ifdef PNG_LIBPNG_SPECIALBUILD
414 # define PNG_LIBPNG_BUILD_TYPE \
415 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL)
416 # else
417 # define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE)
418 # endif
419 #endif
420
421 #ifndef PNG_VERSION_INFO_ONLY
422
423 /* Inhibit C++ name-mangling for libpng functions but not for system calls. */
424 #ifdef __cplusplus
425 extern "C" {
426 #endif /* __cplusplus */
427
428 /* Version information for C files, stored in png.c. This had better match
429 * the version above.
430 */
431 #define png_libpng_ver png_get_header_ver(NULL)
432
433 /* This file is arranged in several sections:
434 *
435 * 1. [omitted]
436 * 2. Any configuration options that can be specified by for the application
437 * code when it is built. (Build time configuration is in pnglibconf.h)
438 * 3. Type definitions (base types are defined in pngconf.h), structure
439 * definitions.
440 * 4. Exported library functions.
441 * 5. Simplified API.
442 * 6. Implementation options.
443 *
444 * The library source code has additional files (principally pngpriv.h) that
445 * allow configuration of the library.
446 */
447
448 /* Section 1: [omitted] */
449
450 /* Section 2: run time configuration
451 * See pnglibconf.h for build time configuration
452 *
453 * Run time configuration allows the application to choose between
454 * implementations of certain arithmetic APIs. The default is set
455 * at build time and recorded in pnglibconf.h, but it is safe to
456 * override these (and only these) settings. Note that this won't
457 * change what the library does, only application code, and the
458 * settings can (and probably should) be made on a per-file basis
459 * by setting the #defines before including png.h
460 *
461 * Use macros to read integers from PNG data or use the exported
462 * functions?
463 * PNG_USE_READ_MACROS: use the macros (see below) Note that
464 * the macros evaluate their argument multiple times.
465 * PNG_NO_USE_READ_MACROS: call the relevant library function.
466 *
467 * Use the alternative algorithm for compositing alpha samples that
468 * does not use division?
469 * PNG_READ_COMPOSITE_NODIV_SUPPORTED: use the 'no division'
470 * algorithm.
471 * PNG_NO_READ_COMPOSITE_NODIV: use the 'division' algorithm.
472 *
473 * How to handle benign errors if PNG_ALLOW_BENIGN_ERRORS is
474 * false?
475 * PNG_ALLOW_BENIGN_ERRORS: map calls to the benign error
476 * APIs to png_warning.
477 * Otherwise the calls are mapped to png_error.
478 */
479
480 /* Section 3: type definitions, including structures and compile time
481 * constants.
482 * See pngconf.h for base types that vary by machine/system
483 */
484
485 /* This triggers a compiler error in png.c, if png.c and png.h
486 * do not agree upon the version number.
487 */
488 typedef char* png_libpng_version_1_6_28;
489
490 /* Basic control structions. Read libpng-manual.txt or libpng.3 for more info.
491 *
492 * png_struct is the cache of information used while reading or writing a single
493 * PNG file. One of these is always required, although the simplified API
494 * (below) hides the creation and destruction of it.
495 */
496 typedef struct png_struct_def png_struct;
497 typedef const png_struct * png_const_structp;
498 typedef png_struct * png_structp;
499 typedef png_struct * * png_structpp;
500
501 /* png_info contains information read from or to be written to a PNG file. One
502 * or more of these must exist while reading or creating a PNG file. The
503 * information is not used by libpng during read but is used to control what
504 * gets written when a PNG file is created. "png_get_" function calls read
505 * information during read and "png_set_" functions calls write information
506 * when creating a PNG.
507 * been moved into a separate header file that is not accessible to
508 * applications. Read libpng-manual.txt or libpng.3 for more info.
509 */
510 typedef struct png_info_def png_info;
511 typedef png_info * png_infop;
512 typedef const png_info * png_const_infop;
513 typedef png_info * * png_infopp;
514
515 /* Types with names ending 'p' are pointer types. The corresponding types with
516 * names ending 'rp' are identical pointer types except that the pointer is
517 * marked 'restrict', which means that it is the only pointer to the object
518 * passed to the function. Applications should not use the 'restrict' types;
519 * it is always valid to pass 'p' to a pointer with a function argument of the
520 * corresponding 'rp' type. Different compilers have different rules with
521 * regard to type matching in the presence of 'restrict'. For backward
522 * compatibility libpng callbacks never have 'restrict' in their parameters and,
523 * consequentially, writing portable application code is extremely difficult if
524 * an attempt is made to use 'restrict'.
525 */
526 typedef png_struct * PNG_RESTRICT png_structrp;
527 typedef const png_struct * PNG_RESTRICT png_const_structrp;
528 typedef png_info * PNG_RESTRICT png_inforp;
529 typedef const png_info * PNG_RESTRICT png_const_inforp;
530
531 /* Three color definitions. The order of the red, green, and blue, (and the
532 * exact size) is not important, although the size of the fields need to
533 * be png_byte or png_uint_16 (as defined below).
534 */
535 typedef struct png_color_struct
536 {
537 png_byte red;
538 png_byte green;
539 png_byte blue;
540 } png_color;
541 typedef png_color * png_colorp;
542 typedef const png_color * png_const_colorp;
543 typedef png_color * * png_colorpp;
544
545 typedef struct png_color_16_struct
546 {
547 png_byte index; /* used for palette files */
548 png_uint_16 red; /* for use in red green blue files */
549 png_uint_16 green;
550 png_uint_16 blue;
551 png_uint_16 gray; /* for use in grayscale files */
552 } png_color_16;
553 typedef png_color_16 * png_color_16p;
554 typedef const png_color_16 * png_const_color_16p;
555 typedef png_color_16 * * png_color_16pp;
556
557 typedef struct png_color_8_struct
558 {
559 png_byte red; /* for use in red green blue files */
560 png_byte green;
561 png_byte blue;
562 png_byte gray; /* for use in grayscale files */
563 png_byte alpha; /* for alpha channel files */
564 } png_color_8;
565 typedef png_color_8 * png_color_8p;
566 typedef const png_color_8 * png_const_color_8p;
567 typedef png_color_8 * * png_color_8pp;
568
569 /*
570 * The following two structures are used for the in-core representation
571 * of sPLT chunks.
572 */
573 typedef struct png_sPLT_entry_struct
574 {
575 png_uint_16 red;
576 png_uint_16 green;
577 png_uint_16 blue;
578 png_uint_16 alpha;
579 png_uint_16 frequency;
580 } png_sPLT_entry;
581 typedef png_sPLT_entry * png_sPLT_entryp;
582 typedef const png_sPLT_entry * png_const_sPLT_entryp;
583 typedef png_sPLT_entry * * png_sPLT_entrypp;
584
585 /* When the depth of the sPLT palette is 8 bits, the color and alpha samples
586 * occupy the LSB of their respective members, and the MSB of each member
587 * is zero-filled. The frequency member always occupies the full 16 bits.
588 */
589
590 typedef struct png_sPLT_struct
591 {
592 png_charp name; /* palette name */
593 png_byte depth; /* depth of palette samples */
594 png_sPLT_entryp entries; /* palette entries */
595 png_int_32 nentries; /* number of palette entries */
596 } png_sPLT_t;
597 typedef png_sPLT_t * png_sPLT_tp;
598 typedef const png_sPLT_t * png_const_sPLT_tp;
599 typedef png_sPLT_t * * png_sPLT_tpp;
600
601 #ifdef PNG_TEXT_SUPPORTED
602 /* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,
603 * and whether that contents is compressed or not. The "key" field
604 * points to a regular zero-terminated C string. The "text" fields can be a
605 * regular C string, an empty string, or a NULL pointer.
606 * However, the structure returned by png_get_text() will always contain
607 * the "text" field as a regular zero-terminated C string (possibly
608 * empty), never a NULL pointer, so it can be safely used in printf() and
609 * other string-handling functions. Note that the "itxt_length", "lang", and
610 * "lang_key" members of the structure only exist when the library is built
611 * with iTXt chunk support. Prior to libpng-1.4.0 the library was built by
612 * default without iTXt support. Also note that when iTXt *is* supported,
613 * the "lang" and "lang_key" fields contain NULL pointers when the
614 * "compression" field contains * PNG_TEXT_COMPRESSION_NONE or
615 * PNG_TEXT_COMPRESSION_zTXt. Note that the "compression value" is not the
616 * same as what appears in the PNG tEXt/zTXt/iTXt chunk's "compression flag"
617 * which is always 0 or 1, or its "compression method" which is always 0.
618 */
619 typedef struct png_text_struct
620 {
621 int compression; /* compression value:
622 -1: tEXt, none
623 0: zTXt, deflate
624 1: iTXt, none
625 2: iTXt, deflate */
626 png_charp key; /* keyword, 1-79 character description of "text" */
627 png_charp text; /* comment, may be an empty string (ie "")
628 or a NULL pointer */
629 png_size_t text_length; /* length of the text string */
630 png_size_t itxt_length; /* length of the itxt string */
631 png_charp lang; /* language code, 0-79 characters
632 or a NULL pointer */
633 png_charp lang_key; /* keyword translated UTF-8 string, 0 or more
634 chars or a NULL pointer */
635 } png_text;
636 typedef png_text * png_textp;
637 typedef const png_text * png_const_textp;
638 typedef png_text * * png_textpp;
639 #endif
640
641 /* Supported compression types for text in PNG files (tEXt, and zTXt).
642 * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */
643 #define PNG_TEXT_COMPRESSION_NONE_WR -3
644 #define PNG_TEXT_COMPRESSION_zTXt_WR -2
645 #define PNG_TEXT_COMPRESSION_NONE -1
646 #define PNG_TEXT_COMPRESSION_zTXt 0
647 #define PNG_ITXT_COMPRESSION_NONE 1
648 #define PNG_ITXT_COMPRESSION_zTXt 2
649 #define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */
650
651 /* png_time is a way to hold the time in an machine independent way.
652 * Two conversions are provided, both from time_t and struct tm. There
653 * is no portable way to convert to either of these structures, as far
654 * as I know. If you know of a portable way, send it to me. As a side
655 * note - PNG has always been Year 2000 compliant!
656 */
657 typedef struct png_time_struct
658 {
659 png_uint_16 year; /* full year, as in, 1995 */
660 png_byte month; /* month of year, 1 - 12 */
661 png_byte day; /* day of month, 1 - 31 */
662 png_byte hour; /* hour of day, 0 - 23 */
663 png_byte minute; /* minute of hour, 0 - 59 */
664 png_byte second; /* second of minute, 0 - 60 (for leap seconds) */
665 } png_time;
666 typedef png_time * png_timep;
667 typedef const png_time * png_const_timep;
668 typedef png_time * * png_timepp;
669
670 #if defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) ||\
671 defined(PNG_USER_CHUNKS_SUPPORTED)
672 /* png_unknown_chunk is a structure to hold queued chunks for which there is
673 * no specific support. The idea is that we can use this to queue
674 * up private chunks for output even though the library doesn't actually
675 * know about their semantics.
676 *
677 * The data in the structure is set by libpng on read and used on write.
678 */
679 typedef struct png_unknown_chunk_t
680 {
681 png_byte name[5]; /* Textual chunk name with '\0' terminator */
682 png_byte *data; /* Data, should not be modified on read! */
683 png_size_t size;
684
685 /* On write 'location' must be set using the flag values listed below.
686 * Notice that on read it is set by libpng however the values stored have
687 * more bits set than are listed below. Always treat the value as a
688 * bitmask. On write set only one bit - setting multiple bits may cause the
689 * chunk to be written in multiple places.
690 */
691 png_byte location; /* mode of operation at read time */
692 }
693 png_unknown_chunk;
694
695 typedef png_unknown_chunk * png_unknown_chunkp;
696 typedef const png_unknown_chunk * png_const_unknown_chunkp;
697 typedef png_unknown_chunk * * png_unknown_chunkpp;
698 #endif
699
700 /* Flag values for the unknown chunk location byte. */
701 #define PNG_HAVE_IHDR 0x01
702 #define PNG_HAVE_PLTE 0x02
703 #define PNG_AFTER_IDAT 0x08
704
705 /* Maximum positive integer used in PNG is (2^31)-1 */
706 #define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL)
707 #define PNG_UINT_32_MAX ((png_uint_32)(-1))
708 #define PNG_SIZE_MAX ((png_size_t)(-1))
709
710 /* These are constants for fixed point values encoded in the
711 * PNG specification manner (x100000)
712 */
713 #define PNG_FP_1 100000
714 #define PNG_FP_HALF 50000
715 #define PNG_FP_MAX ((png_fixed_point)0x7fffffffL)
716 #define PNG_FP_MIN (-PNG_FP_MAX)
717
718 /* These describe the color_type field in png_info. */
719 /* color type masks */
720 #define PNG_COLOR_MASK_PALETTE 1
721 #define PNG_COLOR_MASK_COLOR 2
722 #define PNG_COLOR_MASK_ALPHA 4
723
724 /* color types. Note that not all combinations are legal */
725 #define PNG_COLOR_TYPE_GRAY 0
726 #define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
727 #define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR)
728 #define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
729 #define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
730 /* aliases */
731 #define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA
732 #define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA
733
734 /* This is for compression type. PNG 1.0-1.2 only define the single type. */
735 #define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */
736 #define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE
737
738 /* This is for filter type. PNG 1.0-1.2 only define the single type. */
739 #define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */
740 #define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */
741 #define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE
742
743 /* These are for the interlacing type. These values should NOT be changed. */
744 #define PNG_INTERLACE_NONE 0 /* Non-interlaced image */
745 #define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */
746 #define PNG_INTERLACE_LAST 2 /* Not a valid value */
747
748 /* These are for the oFFs chunk. These values should NOT be changed. */
749 #define PNG_OFFSET_PIXEL 0 /* Offset in pixels */
750 #define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */
751 #define PNG_OFFSET_LAST 2 /* Not a valid value */
752
753 /* These are for the pCAL chunk. These values should NOT be changed. */
754 #define PNG_EQUATION_LINEAR 0 /* Linear transformation */
755 #define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */
756 #define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */
757 #define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */
758 #define PNG_EQUATION_LAST 4 /* Not a valid value */
759
760 /* These are for the sCAL chunk. These values should NOT be changed. */
761 #define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */
762 #define PNG_SCALE_METER 1 /* meters per pixel */
763 #define PNG_SCALE_RADIAN 2 /* radians per pixel */
764 #define PNG_SCALE_LAST 3 /* Not a valid value */
765
766 /* These are for the pHYs chunk. These values should NOT be changed. */
767 #define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */
768 #define PNG_RESOLUTION_METER 1 /* pixels/meter */
769 #define PNG_RESOLUTION_LAST 2 /* Not a valid value */
770
771 /* These are for the sRGB chunk. These values should NOT be changed. */
772 #define PNG_sRGB_INTENT_PERCEPTUAL 0
773 #define PNG_sRGB_INTENT_RELATIVE 1
774 #define PNG_sRGB_INTENT_SATURATION 2
775 #define PNG_sRGB_INTENT_ABSOLUTE 3
776 #define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */
777
778 /* This is for text chunks */
779 #define PNG_KEYWORD_MAX_LENGTH 79
780
781 /* Maximum number of entries in PLTE/sPLT/tRNS arrays */
782 #define PNG_MAX_PALETTE_LENGTH 256
783
784 /* These determine if an ancillary chunk's data has been successfully read
785 * from the PNG header, or if the application has filled in the corresponding
786 * data in the info_struct to be written into the output file. The values
787 * of the PNG_INFO_<chunk> defines should NOT be changed.
788 */
789 #define PNG_INFO_gAMA 0x0001U
790 #define PNG_INFO_sBIT 0x0002U
791 #define PNG_INFO_cHRM 0x0004U
792 #define PNG_INFO_PLTE 0x0008U
793 #define PNG_INFO_tRNS 0x0010U
794 #define PNG_INFO_bKGD 0x0020U
795 #define PNG_INFO_hIST 0x0040U
796 #define PNG_INFO_pHYs 0x0080U
797 #define PNG_INFO_oFFs 0x0100U
798 #define PNG_INFO_tIME 0x0200U
799 #define PNG_INFO_pCAL 0x0400U
800 #define PNG_INFO_sRGB 0x0800U /* GR-P, 0.96a */
801 #define PNG_INFO_iCCP 0x1000U /* ESR, 1.0.6 */
802 #define PNG_INFO_sPLT 0x2000U /* ESR, 1.0.6 */
803 #define PNG_INFO_sCAL 0x4000U /* ESR, 1.0.6 */
804 #define PNG_INFO_IDAT 0x8000U /* ESR, 1.0.6 */
805
806 /* This is used for the transformation routines, as some of them
807 * change these values for the row. It also should enable using
808 * the routines for other purposes.
809 */
810 typedef struct png_row_info_struct
811 {
812 png_uint_32 width; /* width of row */
813 png_size_t rowbytes; /* number of bytes in row */
814 png_byte color_type; /* color type of row */
815 png_byte bit_depth; /* bit depth of row */
816 png_byte channels; /* number of channels (1, 2, 3, or 4) */
817 png_byte pixel_depth; /* bits per pixel (depth * channels) */
818 } png_row_info;
819
820 typedef png_row_info * png_row_infop;
821 typedef png_row_info * * png_row_infopp;
822
823 /* These are the function types for the I/O functions and for the functions
824 * that allow the user to override the default I/O functions with his or her
825 * own. The png_error_ptr type should match that of user-supplied warning
826 * and error functions, while the png_rw_ptr type should match that of the
827 * user read/write data functions. Note that the 'write' function must not
828 * modify the buffer it is passed. The 'read' function, on the other hand, is
829 * expected to return the read data in the buffer.
830 */
831 typedef PNG_CALLBACK(void, *png_error_ptr, (png_structp, png_const_charp));
832 typedef PNG_CALLBACK(void, *png_rw_ptr, (png_structp, png_bytep, png_size_t));
833 typedef PNG_CALLBACK(void, *png_flush_ptr, (png_structp));
834 typedef PNG_CALLBACK(void, *png_read_status_ptr, (png_structp, png_uint_32,
835 int));
836 typedef PNG_CALLBACK(void, *png_write_status_ptr, (png_structp, png_uint_32,
837 int));
838
839 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
840 typedef PNG_CALLBACK(void, *png_progressive_info_ptr, (png_structp, png_infop));
841 typedef PNG_CALLBACK(void, *png_progressive_end_ptr, (png_structp, png_infop));
842
843 /* The following callback receives png_uint_32 row_number, int pass for the
844 * png_bytep data of the row. When transforming an interlaced image the
845 * row number is the row number within the sub-image of the interlace pass, so
846 * the value will increase to the height of the sub-image (not the full image)
847 * then reset to 0 for the next pass.
848 *
849 * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
850 * find the output pixel (x,y) given an interlaced sub-image pixel
851 * (row,col,pass). (See below for these macros.)
852 */
853 typedef PNG_CALLBACK(void, *png_progressive_row_ptr, (png_structp, png_bytep,
854 png_uint_32, int));
855 #endif
856
857 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
858 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
859 typedef PNG_CALLBACK(void, *png_user_transform_ptr, (png_structp, png_row_infop,
860 png_bytep));
861 #endif
862
863 #ifdef PNG_USER_CHUNKS_SUPPORTED
864 typedef PNG_CALLBACK(int, *png_user_chunk_ptr, (png_structp,
865 png_unknown_chunkp));
866 #endif
867 #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
868 /* not used anywhere */
869 /* typedef PNG_CALLBACK(void, *png_unknown_chunk_ptr, (png_structp)); */
870 #endif
871
872 #ifdef PNG_SETJMP_SUPPORTED
873 /* This must match the function definition in <setjmp.h>, and the application
874 * must include this before png.h to obtain the definition of jmp_buf. The
875 * function is required to be PNG_NORETURN, but this is not checked. If the
876 * function does return the application will crash via an abort() or similar
877 * system level call.
878 *
879 * If you get a warning here while building the library you may need to make
880 * changes to ensure that pnglibconf.h records the calling convention used by
881 * your compiler. This may be very difficult - try using a different compiler
882 * to build the library!
883 */
884 PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)), typedef);
885 #endif
886
887 /* Transform masks for the high-level interface */
888 #define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */
889 #define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */
890 #define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */
891 #define PNG_TRANSFORM_PACKING 0x0004 /* read and write */
892 #define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */
893 #define PNG_TRANSFORM_EXPAND 0x0010 /* read only */
894 #define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */
895 #define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */
896 #define PNG_TRANSFORM_BGR 0x0080 /* read and write */
897 #define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */
898 #define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */
899 #define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */
900 #define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* write only */
901 /* Added to libpng-1.2.34 */
902 #define PNG_TRANSFORM_STRIP_FILLER_BEFORE PNG_TRANSFORM_STRIP_FILLER
903 #define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */
904 /* Added to libpng-1.4.0 */
905 #define PNG_TRANSFORM_GRAY_TO_RGB 0x2000 /* read only */
906 /* Added to libpng-1.5.4 */
907 #define PNG_TRANSFORM_EXPAND_16 0x4000 /* read only */
908 #if INT_MAX >= 0x8000 /* else this might break */
909 #define PNG_TRANSFORM_SCALE_16 0x8000 /* read only */
910 #endif
911
912 /* Flags for MNG supported features */
913 #define PNG_FLAG_MNG_EMPTY_PLTE 0x01
914 #define PNG_FLAG_MNG_FILTER_64 0x04
915 #define PNG_ALL_MNG_FEATURES 0x05
916
917 /* NOTE: prior to 1.5 these functions had no 'API' style declaration,
918 * this allowed the zlib default functions to be used on Windows
919 * platforms. In 1.5 the zlib default malloc (which just calls malloc and
920 * ignores the first argument) should be completely compatible with the
921 * following.
922 */
923 typedef PNG_CALLBACK(png_voidp, *png_malloc_ptr, (png_structp,
924 png_alloc_size_t));
925 typedef PNG_CALLBACK(void, *png_free_ptr, (png_structp, png_voidp));
926
927 /* Section 4: exported functions
928 * Here are the function definitions most commonly used. This is not
929 * the place to find out how to use libpng. See libpng-manual.txt for the
930 * full explanation, see example.c for the summary. This just provides
931 * a simple one line description of the use of each function.
932 *
933 * The PNG_EXPORT() and PNG_EXPORTA() macros used below are defined in
934 * pngconf.h and in the *.dfn files in the scripts directory.
935 *
936 * PNG_EXPORT(ordinal, type, name, (args));
937 *
938 * ordinal: ordinal that is used while building
939 * *.def files. The ordinal value is only
940 * relevant when preprocessing png.h with
941 * the *.dfn files for building symbol table
942 * entries, and are removed by pngconf.h.
943 * type: return type of the function
944 * name: function name
945 * args: function arguments, with types
946 *
947 * When we wish to append attributes to a function prototype we use
948 * the PNG_EXPORTA() macro instead.
949 *
950 * PNG_EXPORTA(ordinal, type, name, (args), attributes);
951 *
952 * ordinal, type, name, and args: same as in PNG_EXPORT().
953 * attributes: function attributes
954 */
955
956 /* Returns the version number of the library */
957 PNG_EXPORT(1, png_uint_32, png_access_version_number, (void));
958
959 /* Tell lib we have already handled the first <num_bytes> magic bytes.
960 * Handling more than 8 bytes from the beginning of the file is an error.
961 */
962 PNG_EXPORT(2, void, png_set_sig_bytes, (png_structrp png_ptr, int num_bytes));
963
964 /* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
965 * PNG file. Returns zero if the supplied bytes match the 8-byte PNG
966 * signature, and non-zero otherwise. Having num_to_check == 0 or
967 * start > 7 will always fail (ie return non-zero).
968 */
969 PNG_EXPORT(3, int, png_sig_cmp, (png_const_bytep sig, png_size_t start,
970 png_size_t num_to_check));
971
972 /* Simple signature checking function. This is the same as calling
973 * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n).
974 */
975 #define png_check_sig(sig, n) !png_sig_cmp((sig), 0, (n))
976
977 /* Allocate and initialize png_ptr struct for reading, and any other memory. */
978 PNG_EXPORTA(4, png_structp, png_create_read_struct,
979 (png_const_charp user_png_ver, png_voidp error_ptr,
980 png_error_ptr error_fn, png_error_ptr warn_fn),
981 PNG_ALLOCATED);
982
983 /* Allocate and initialize png_ptr struct for writing, and any other memory */
984 PNG_EXPORTA(5, png_structp, png_create_write_struct,
985 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
986 png_error_ptr warn_fn),
987 PNG_ALLOCATED);
988
989 PNG_EXPORT(6, png_size_t, png_get_compression_buffer_size,
990 (png_const_structrp png_ptr));
991
992 PNG_EXPORT(7, void, png_set_compression_buffer_size, (png_structrp png_ptr,
993 png_size_t size));
994
995 /* Moved from pngconf.h in 1.4.0 and modified to ensure setjmp/longjmp
996 * match up.
997 */
998 #ifdef PNG_SETJMP_SUPPORTED
999 /* This function returns the jmp_buf built in to *png_ptr. It must be
1000 * supplied with an appropriate 'longjmp' function to use on that jmp_buf
1001 * unless the default error function is overridden in which case NULL is
1002 * acceptable. The size of the jmp_buf is checked against the actual size
1003 * allocated by the library - the call will return NULL on a mismatch
1004 * indicating an ABI mismatch.
1005 */
1006 PNG_EXPORT(8, jmp_buf*, png_set_longjmp_fn, (png_structrp png_ptr,
1007 png_longjmp_ptr longjmp_fn, size_t jmp_buf_size));
1008 # define png_jmpbuf(png_ptr) \
1009 (*png_set_longjmp_fn((png_ptr), longjmp, (sizeof (jmp_buf))))
1010 #else
1011 # define png_jmpbuf(png_ptr) \
1012 (LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP)
1013 #endif
1014 /* This function should be used by libpng applications in place of
1015 * longjmp(png_ptr->jmpbuf, val). If longjmp_fn() has been set, it
1016 * will use it; otherwise it will call PNG_ABORT(). This function was
1017 * added in libpng-1.5.0.
1018 */
1019 PNG_EXPORTA(9, void, png_longjmp, (png_const_structrp png_ptr, int val),
1020 PNG_NORETURN);
1021
1022 #ifdef PNG_READ_SUPPORTED
1023 /* Reset the compression stream */
1024 PNG_EXPORTA(10, int, png_reset_zstream, (png_structrp png_ptr), PNG_DEPRECATED);
1025 #endif
1026
1027 /* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */
1028 #ifdef PNG_USER_MEM_SUPPORTED
1029 PNG_EXPORTA(11, png_structp, png_create_read_struct_2,
1030 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
1031 png_error_ptr warn_fn,
1032 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn),
1033 PNG_ALLOCATED);
1034 PNG_EXPORTA(12, png_structp, png_create_write_struct_2,
1035 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
1036 png_error_ptr warn_fn,
1037 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn),
1038 PNG_ALLOCATED);
1039 #endif
1040
1041 /* Write the PNG file signature. */
1042 PNG_EXPORT(13, void, png_write_sig, (png_structrp png_ptr));
1043
1044 /* Write a PNG chunk - size, type, (optional) data, CRC. */
1045 PNG_EXPORT(14, void, png_write_chunk, (png_structrp png_ptr, png_const_bytep
1046 chunk_name, png_const_bytep data, png_size_t length));
1047
1048 /* Write the start of a PNG chunk - length and chunk name. */
1049 PNG_EXPORT(15, void, png_write_chunk_start, (png_structrp png_ptr,
1050 png_const_bytep chunk_name, png_uint_32 length));
1051
1052 /* Write the data of a PNG chunk started with png_write_chunk_start(). */
1053 PNG_EXPORT(16, void, png_write_chunk_data, (png_structrp png_ptr,
1054 png_const_bytep data, png_size_t length));
1055
1056 /* Finish a chunk started with png_write_chunk_start() (includes CRC). */
1057 PNG_EXPORT(17, void, png_write_chunk_end, (png_structrp png_ptr));
1058
1059 /* Allocate and initialize the info structure */
1060 PNG_EXPORTA(18, png_infop, png_create_info_struct, (png_const_structrp png_ptr),
1061 PNG_ALLOCATED);
1062
1063 /* DEPRECATED: this function allowed init structures to be created using the
1064 * default allocation method (typically malloc). Use is deprecated in 1.6.0 and
1065 * the API will be removed in the future.
1066 */
1067 PNG_EXPORTA(19, void, png_info_init_3, (png_infopp info_ptr,
1068 png_size_t png_info_struct_size), PNG_DEPRECATED);
1069
1070 /* Writes all the PNG information before the image. */
1071 PNG_EXPORT(20, void, png_write_info_before_PLTE,
1072 (png_structrp png_ptr, png_const_inforp info_ptr));
1073 PNG_EXPORT(21, void, png_write_info,
1074 (png_structrp png_ptr, png_const_inforp info_ptr));
1075
1076 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1077 /* Read the information before the actual image data. */
1078 PNG_EXPORT(22, void, png_read_info,
1079 (png_structrp png_ptr, png_inforp info_ptr));
1080 #endif
1081
1082 #ifdef PNG_TIME_RFC1123_SUPPORTED
1083 /* Convert to a US string format: there is no localization support in this
1084 * routine. The original implementation used a 29 character buffer in
1085 * png_struct, this will be removed in future versions.
1086 */
1087 #if PNG_LIBPNG_VER < 10700
1088 /* To do: remove this from libpng17 (and from libpng17/png.c and pngstruct.h) */
1089 PNG_EXPORTA(23, png_const_charp, png_convert_to_rfc1123, (png_structrp png_ptr,
1090 png_const_timep ptime),PNG_DEPRECATED);
1091 #endif
1092 PNG_EXPORT(241, int, png_convert_to_rfc1123_buffer, (char out[29],
1093 png_const_timep ptime));
1094 #endif
1095
1096 #ifdef PNG_CONVERT_tIME_SUPPORTED
1097 /* Convert from a struct tm to png_time */
1098 PNG_EXPORT(24, void, png_convert_from_struct_tm, (png_timep ptime,
1099 const struct tm * ttime));
1100
1101 /* Convert from time_t to png_time. Uses gmtime() */
1102 PNG_EXPORT(25, void, png_convert_from_time_t, (png_timep ptime, time_t ttime));
1103 #endif /* CONVERT_tIME */
1104
1105 #ifdef PNG_READ_EXPAND_SUPPORTED
1106 /* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
1107 PNG_EXPORT(26, void, png_set_expand, (png_structrp png_ptr));
1108 PNG_EXPORT(27, void, png_set_expand_gray_1_2_4_to_8, (png_structrp png_ptr));
1109 PNG_EXPORT(28, void, png_set_palette_to_rgb, (png_structrp png_ptr));
1110 PNG_EXPORT(29, void, png_set_tRNS_to_alpha, (png_structrp png_ptr));
1111 #endif
1112
1113 #ifdef PNG_READ_EXPAND_16_SUPPORTED
1114 /* Expand to 16-bit channels, forces conversion of palette to RGB and expansion
1115 * of a tRNS chunk if present.
1116 */
1117 PNG_EXPORT(221, void, png_set_expand_16, (png_structrp png_ptr));
1118 #endif
1119
1120 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
1121 /* Use blue, green, red order for pixels. */
1122 PNG_EXPORT(30, void, png_set_bgr, (png_structrp png_ptr));
1123 #endif
1124
1125 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
1126 /* Expand the grayscale to 24-bit RGB if necessary. */
1127 PNG_EXPORT(31, void, png_set_gray_to_rgb, (png_structrp png_ptr));
1128 #endif
1129
1130 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1131 /* Reduce RGB to grayscale. */
1132 #define PNG_ERROR_ACTION_NONE 1
1133 #define PNG_ERROR_ACTION_WARN 2
1134 #define PNG_ERROR_ACTION_ERROR 3
1135 #define PNG_RGB_TO_GRAY_DEFAULT (-1)/*for red/green coefficients*/
1136
1137 PNG_FP_EXPORT(32, void, png_set_rgb_to_gray, (png_structrp png_ptr,
1138 int error_action, double red, double green))
1139 PNG_FIXED_EXPORT(33, void, png_set_rgb_to_gray_fixed, (png_structrp png_ptr,
1140 int error_action, png_fixed_point red, png_fixed_point green))
1141
1142 PNG_EXPORT(34, png_byte, png_get_rgb_to_gray_status, (png_const_structrp
1143 png_ptr));
1144 #endif
1145
1146 #ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED
1147 PNG_EXPORT(35, void, png_build_grayscale_palette, (int bit_depth,
1148 png_colorp palette));
1149 #endif
1150
1151 #ifdef PNG_READ_ALPHA_MODE_SUPPORTED
1152 /* How the alpha channel is interpreted - this affects how the color channels
1153 * of a PNG file are returned to the calling application when an alpha channel,
1154 * or a tRNS chunk in a palette file, is present.
1155 *
1156 * This has no effect on the way pixels are written into a PNG output
1157 * datastream. The color samples in a PNG datastream are never premultiplied
1158 * with the alpha samples.
1159 *
1160 * The default is to return data according to the PNG specification: the alpha
1161 * channel is a linear measure of the contribution of the pixel to the
1162 * corresponding composited pixel, and the color channels are unassociated
1163 * (not premultiplied). The gamma encoded color channels must be scaled
1164 * according to the contribution and to do this it is necessary to undo
1165 * the encoding, scale the color values, perform the composition and reencode
1166 * the values. This is the 'PNG' mode.
1167 *
1168 * The alternative is to 'associate' the alpha with the color information by
1169 * storing color channel values that have been scaled by the alpha.
1170 * image. These are the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' modes
1171 * (the latter being the two common names for associated alpha color channels).
1172 *
1173 * For the 'OPTIMIZED' mode, a pixel is treated as opaque only if the alpha
1174 * value is equal to the maximum value.
1175 *
1176 * The final choice is to gamma encode the alpha channel as well. This is
1177 * broken because, in practice, no implementation that uses this choice
1178 * correctly undoes the encoding before handling alpha composition. Use this
1179 * choice only if other serious errors in the software or hardware you use
1180 * mandate it; the typical serious error is for dark halos to appear around
1181 * opaque areas of the composited PNG image because of arithmetic overflow.
1182 *
1183 * The API function png_set_alpha_mode specifies which of these choices to use
1184 * with an enumerated 'mode' value and the gamma of the required output:
1185 */
1186 #define PNG_ALPHA_PNG 0 /* according to the PNG standard */
1187 #define PNG_ALPHA_STANDARD 1 /* according to Porter/Duff */
1188 #define PNG_ALPHA_ASSOCIATED 1 /* as above; this is the normal practice */
1189 #define PNG_ALPHA_PREMULTIPLIED 1 /* as above */
1190 #define PNG_ALPHA_OPTIMIZED 2 /* 'PNG' for opaque pixels, else 'STANDARD' */
1191 #define PNG_ALPHA_BROKEN 3 /* the alpha channel is gamma encoded */
1192
1193 PNG_FP_EXPORT(227, void, png_set_alpha_mode, (png_structrp png_ptr, int mode,
1194 double output_gamma))
1195 PNG_FIXED_EXPORT(228, void, png_set_alpha_mode_fixed, (png_structrp png_ptr,
1196 int mode, png_fixed_point output_gamma))
1197 #endif
1198
1199 #if defined(PNG_GAMMA_SUPPORTED) || defined(PNG_READ_ALPHA_MODE_SUPPORTED)
1200 /* The output_gamma value is a screen gamma in libpng terminology: it expresses
1201 * how to decode the output values, not how they are encoded.
1202 */
1203 #define PNG_DEFAULT_sRGB -1 /* sRGB gamma and color space */
1204 #define PNG_GAMMA_MAC_18 -2 /* Old Mac '1.8' gamma and color space */
1205 #define PNG_GAMMA_sRGB 220000 /* Television standards--matches sRGB gamma */
1206 #define PNG_GAMMA_LINEAR PNG_FP_1 /* Linear */
1207 #endif
1208
1209 /* The following are examples of calls to png_set_alpha_mode to achieve the
1210 * required overall gamma correction and, where necessary, alpha
1211 * premultiplication.
1212 *
1213 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
1214 * This is the default libpng handling of the alpha channel - it is not
1215 * pre-multiplied into the color components. In addition the call states
1216 * that the output is for a sRGB system and causes all PNG files without gAMA
1217 * chunks to be assumed to be encoded using sRGB.
1218 *
1219 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
1220 * In this case the output is assumed to be something like an sRGB conformant
1221 * display preceeded by a power-law lookup table of power 1.45. This is how
1222 * early Mac systems behaved.
1223 *
1224 * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR);
1225 * This is the classic Jim Blinn approach and will work in academic
1226 * environments where everything is done by the book. It has the shortcoming
1227 * of assuming that input PNG data with no gamma information is linear - this
1228 * is unlikely to be correct unless the PNG files where generated locally.
1229 * Most of the time the output precision will be so low as to show
1230 * significant banding in dark areas of the image.
1231 *
1232 * png_set_expand_16(pp);
1233 * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB);
1234 * This is a somewhat more realistic Jim Blinn inspired approach. PNG files
1235 * are assumed to have the sRGB encoding if not marked with a gamma value and
1236 * the output is always 16 bits per component. This permits accurate scaling
1237 * and processing of the data. If you know that your input PNG files were
1238 * generated locally you might need to replace PNG_DEFAULT_sRGB with the
1239 * correct value for your system.
1240 *
1241 * png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB);
1242 * If you just need to composite the PNG image onto an existing background
1243 * and if you control the code that does this you can use the optimization
1244 * setting. In this case you just copy completely opaque pixels to the
1245 * output. For pixels that are not completely transparent (you just skip
1246 * those) you do the composition math using png_composite or png_composite_16
1247 * below then encode the resultant 8-bit or 16-bit values to match the output
1248 * encoding.
1249 *
1250 * Other cases
1251 * If neither the PNG nor the standard linear encoding work for you because
1252 * of the software or hardware you use then you have a big problem. The PNG
1253 * case will probably result in halos around the image. The linear encoding
1254 * will probably result in a washed out, too bright, image (it's actually too
1255 * contrasty.) Try the ALPHA_OPTIMIZED mode above - this will probably
1256 * substantially reduce the halos. Alternatively try:
1257 *
1258 * png_set_alpha_mode(pp, PNG_ALPHA_BROKEN, PNG_DEFAULT_sRGB);
1259 * This option will also reduce the halos, but there will be slight dark
1260 * halos round the opaque parts of the image where the background is light.
1261 * In the OPTIMIZED mode the halos will be light halos where the background
1262 * is dark. Take your pick - the halos are unavoidable unless you can get
1263 * your hardware/software fixed! (The OPTIMIZED approach is slightly
1264 * faster.)
1265 *
1266 * When the default gamma of PNG files doesn't match the output gamma.
1267 * If you have PNG files with no gamma information png_set_alpha_mode allows
1268 * you to provide a default gamma, but it also sets the ouput gamma to the
1269 * matching value. If you know your PNG files have a gamma that doesn't
1270 * match the output you can take advantage of the fact that
1271 * png_set_alpha_mode always sets the output gamma but only sets the PNG
1272 * default if it is not already set:
1273 *
1274 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
1275 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
1276 * The first call sets both the default and the output gamma values, the
1277 * second call overrides the output gamma without changing the default. This
1278 * is easier than achieving the same effect with png_set_gamma. You must use
1279 * PNG_ALPHA_PNG for the first call - internal checking in png_set_alpha will
1280 * fire if more than one call to png_set_alpha_mode and png_set_background is
1281 * made in the same read operation, however multiple calls with PNG_ALPHA_PNG
1282 * are ignored.
1283 */
1284
1285 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
1286 PNG_EXPORT(36, void, png_set_strip_alpha, (png_structrp png_ptr));
1287 #endif
1288
1289 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
1290 defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
1291 PNG_EXPORT(37, void, png_set_swap_alpha, (png_structrp png_ptr));
1292 #endif
1293
1294 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
1295 defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
1296 PNG_EXPORT(38, void, png_set_invert_alpha, (png_structrp png_ptr));
1297 #endif
1298
1299 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
1300 /* Add a filler byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */
1301 PNG_EXPORT(39, void, png_set_filler, (png_structrp png_ptr, png_uint_32 filler,
1302 int flags));
1303 /* The values of the PNG_FILLER_ defines should NOT be changed */
1304 # define PNG_FILLER_BEFORE 0
1305 # define PNG_FILLER_AFTER 1
1306 /* Add an alpha byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */
1307 PNG_EXPORT(40, void, png_set_add_alpha, (png_structrp png_ptr,
1308 png_uint_32 filler, int flags));
1309 #endif /* READ_FILLER || WRITE_FILLER */
1310
1311 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
1312 /* Swap bytes in 16-bit depth files. */
1313 PNG_EXPORT(41, void, png_set_swap, (png_structrp png_ptr));
1314 #endif
1315
1316 #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
1317 /* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
1318 PNG_EXPORT(42, void, png_set_packing, (png_structrp png_ptr));
1319 #endif
1320
1321 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
1322 defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1323 /* Swap packing order of pixels in bytes. */
1324 PNG_EXPORT(43, void, png_set_packswap, (png_structrp png_ptr));
1325 #endif
1326
1327 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
1328 /* Converts files to legal bit depths. */
1329 PNG_EXPORT(44, void, png_set_shift, (png_structrp png_ptr, png_const_color_8p
1330 true_bits));
1331 #endif
1332
1333 #if defined(PNG_READ_INTERLACING_SUPPORTED) || \
1334 defined(PNG_WRITE_INTERLACING_SUPPORTED)
1335 /* Have the code handle the interlacing. Returns the number of passes.
1336 * MUST be called before png_read_update_info or png_start_read_image,
1337 * otherwise it will not have the desired effect. Note that it is still
1338 * necessary to call png_read_row or png_read_rows png_get_image_height
1339 * times for each pass.
1340 */
1341 PNG_EXPORT(45, int, png_set_interlace_handling, (png_structrp png_ptr));
1342 #endif
1343
1344 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
1345 /* Invert monochrome files */
1346 PNG_EXPORT(46, void, png_set_invert_mono, (png_structrp png_ptr));
1347 #endif
1348
1349 #ifdef PNG_READ_BACKGROUND_SUPPORTED
1350 /* Handle alpha and tRNS by replacing with a background color. Prior to
1351 * libpng-1.5.4 this API must not be called before the PNG file header has been
1352 * read. Doing so will result in unexpected behavior and possible warnings or
1353 * errors if the PNG file contains a bKGD chunk.
1354 */
1355 PNG_FP_EXPORT(47, void, png_set_background, (png_structrp png_ptr,
1356 png_const_color_16p background_color, int background_gamma_code,
1357 int need_expand, double background_gamma))
1358 PNG_FIXED_EXPORT(215, void, png_set_background_fixed, (png_structrp png_ptr,
1359 png_const_color_16p background_color, int background_gamma_code,
1360 int need_expand, png_fixed_point background_gamma))
1361 #endif
1362 #ifdef PNG_READ_BACKGROUND_SUPPORTED
1363 # define PNG_BACKGROUND_GAMMA_UNKNOWN 0
1364 # define PNG_BACKGROUND_GAMMA_SCREEN 1
1365 # define PNG_BACKGROUND_GAMMA_FILE 2
1366 # define PNG_BACKGROUND_GAMMA_UNIQUE 3
1367 #endif
1368
1369 #ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
1370 /* Scale a 16-bit depth file down to 8-bit, accurately. */
1371 PNG_EXPORT(229, void, png_set_scale_16, (png_structrp png_ptr));
1372 #endif
1373
1374 #ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
1375 #define PNG_READ_16_TO_8_SUPPORTED /* Name prior to 1.5.4 */
1376 /* Strip the second byte of information from a 16-bit depth file. */
1377 PNG_EXPORT(48, void, png_set_strip_16, (png_structrp png_ptr));
1378 #endif
1379
1380 #ifdef PNG_READ_QUANTIZE_SUPPORTED
1381 /* Turn on quantizing, and reduce the palette to the number of colors
1382 * available.
1383 */
1384 PNG_EXPORT(49, void, png_set_quantize, (png_structrp png_ptr,
1385 png_colorp palette, int num_palette, int maximum_colors,
1386 png_const_uint_16p histogram, int full_quantize));
1387 #endif
1388
1389 #ifdef PNG_READ_GAMMA_SUPPORTED
1390 /* The threshold on gamma processing is configurable but hard-wired into the
1391 * library. The following is the floating point variant.
1392 */
1393 #define PNG_GAMMA_THRESHOLD (PNG_GAMMA_THRESHOLD_FIXED*.00001)
1394
1395 /* Handle gamma correction. Screen_gamma=(display_exponent).
1396 * NOTE: this API simply sets the screen and file gamma values. It will
1397 * therefore override the value for gamma in a PNG file if it is called after
1398 * the file header has been read - use with care - call before reading the PNG
1399 * file for best results!
1400 *
1401 * These routines accept the same gamma values as png_set_alpha_mode (described
1402 * above). The PNG_GAMMA_ defines and PNG_DEFAULT_sRGB can be passed to either
1403 * API (floating point or fixed.) Notice, however, that the 'file_gamma' value
1404 * is the inverse of a 'screen gamma' value.
1405 */
1406 PNG_FP_EXPORT(50, void, png_set_gamma, (png_structrp png_ptr,
1407 double screen_gamma, double override_file_gamma))
1408 PNG_FIXED_EXPORT(208, void, png_set_gamma_fixed, (png_structrp png_ptr,
1409 png_fixed_point screen_gamma, png_fixed_point override_file_gamma))
1410 #endif
1411
1412 #ifdef PNG_WRITE_FLUSH_SUPPORTED
1413 /* Set how many lines between output flushes - 0 for no flushing */
1414 PNG_EXPORT(51, void, png_set_flush, (png_structrp png_ptr, int nrows));
1415 /* Flush the current PNG output buffer */
1416 PNG_EXPORT(52, void, png_write_flush, (png_structrp png_ptr));
1417 #endif
1418
1419 /* Optional update palette with requested transformations */
1420 PNG_EXPORT(53, void, png_start_read_image, (png_structrp png_ptr));
1421
1422 /* Optional call to update the users info structure */
1423 PNG_EXPORT(54, void, png_read_update_info, (png_structrp png_ptr,
1424 png_inforp info_ptr));
1425
1426 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1427 /* Read one or more rows of image data. */
1428 PNG_EXPORT(55, void, png_read_rows, (png_structrp png_ptr, png_bytepp row,
1429 png_bytepp display_row, png_uint_32 num_rows));
1430 #endif
1431
1432 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1433 /* Read a row of data. */
1434 PNG_EXPORT(56, void, png_read_row, (png_structrp png_ptr, png_bytep row,
1435 png_bytep display_row));
1436 #endif
1437
1438 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1439 /* Read the whole image into memory at once. */
1440 PNG_EXPORT(57, void, png_read_image, (png_structrp png_ptr, png_bytepp image));
1441 #endif
1442
1443 /* Write a row of image data */
1444 PNG_EXPORT(58, void, png_write_row, (png_structrp png_ptr,
1445 png_const_bytep row));
1446
1447 /* Write a few rows of image data: (*row) is not written; however, the type
1448 * is declared as writeable to maintain compatibility with previous versions
1449 * of libpng and to allow the 'display_row' array from read_rows to be passed
1450 * unchanged to write_rows.
1451 */
1452 PNG_EXPORT(59, void, png_write_rows, (png_structrp png_ptr, png_bytepp row,
1453 png_uint_32 num_rows));
1454
1455 /* Write the image data */
1456 PNG_EXPORT(60, void, png_write_image, (png_structrp png_ptr, png_bytepp image));
1457
1458 /* Write the end of the PNG file. */
1459 PNG_EXPORT(61, void, png_write_end, (png_structrp png_ptr,
1460 png_inforp info_ptr));
1461
1462 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1463 /* Read the end of the PNG file. */
1464 PNG_EXPORT(62, void, png_read_end, (png_structrp png_ptr, png_inforp info_ptr));
1465 #endif
1466
1467 /* Free any memory associated with the png_info_struct */
1468 PNG_EXPORT(63, void, png_destroy_info_struct, (png_const_structrp png_ptr,
1469 png_infopp info_ptr_ptr));
1470
1471 /* Free any memory associated with the png_struct and the png_info_structs */
1472 PNG_EXPORT(64, void, png_destroy_read_struct, (png_structpp png_ptr_ptr,
1473 png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr));
1474
1475 /* Free any memory associated with the png_struct and the png_info_structs */
1476 PNG_EXPORT(65, void, png_destroy_write_struct, (png_structpp png_ptr_ptr,
1477 png_infopp info_ptr_ptr));
1478
1479 /* Set the libpng method of handling chunk CRC errors */
1480 PNG_EXPORT(66, void, png_set_crc_action, (png_structrp png_ptr, int crit_action,
1481 int ancil_action));
1482
1483 /* Values for png_set_crc_action() say how to handle CRC errors in
1484 * ancillary and critical chunks, and whether to use the data contained
1485 * therein. Note that it is impossible to "discard" data in a critical
1486 * chunk. For versions prior to 0.90, the action was always error/quit,
1487 * whereas in version 0.90 and later, the action for CRC errors in ancillary
1488 * chunks is warn/discard. These values should NOT be changed.
1489 *
1490 * value action:critical action:ancillary
1491 */
1492 #define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */
1493 #define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */
1494 #define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */
1495 #define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */
1496 #define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */
1497 #define PNG_CRC_NO_CHANGE 5 /* use current value use current value */
1498
1499 #ifdef PNG_WRITE_SUPPORTED
1500 /* These functions give the user control over the scan-line filtering in
1501 * libpng and the compression methods used by zlib. These functions are
1502 * mainly useful for testing, as the defaults should work with most users.
1503 * Those users who are tight on memory or want faster performance at the
1504 * expense of compression can modify them. See the compression library
1505 * header file (zlib.h) for an explination of the compression functions.
1506 */
1507
1508 /* Set the filtering method(s) used by libpng. Currently, the only valid
1509 * value for "method" is 0.
1510 */
1511 PNG_EXPORT(67, void, png_set_filter, (png_structrp png_ptr, int method,
1512 int filters));
1513 #endif /* WRITE */
1514
1515 /* Flags for png_set_filter() to say which filters to use. The flags
1516 * are chosen so that they don't conflict with real filter types
1517 * below, in case they are supplied instead of the #defined constants.
1518 * These values should NOT be changed.
1519 */
1520 #define PNG_NO_FILTERS 0x00
1521 #define PNG_FILTER_NONE 0x08
1522 #define PNG_FILTER_SUB 0x10
1523 #define PNG_FILTER_UP 0x20
1524 #define PNG_FILTER_AVG 0x40
1525 #define PNG_FILTER_PAETH 0x80
1526 #define PNG_FAST_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP)
1527 #define PNG_ALL_FILTERS (PNG_FAST_FILTERS | PNG_FILTER_AVG | PNG_FILTER_PAETH)
1528
1529 /* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
1530 * These defines should NOT be changed.
1531 */
1532 #define PNG_FILTER_VALUE_NONE 0
1533 #define PNG_FILTER_VALUE_SUB 1
1534 #define PNG_FILTER_VALUE_UP 2
1535 #define PNG_FILTER_VALUE_AVG 3
1536 #define PNG_FILTER_VALUE_PAETH 4
1537 #define PNG_FILTER_VALUE_LAST 5
1538
1539 #ifdef PNG_WRITE_SUPPORTED
1540 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* DEPRECATED */
1541 PNG_FP_EXPORT(68, void, png_set_filter_heuristics, (png_structrp png_ptr,
1542 int heuristic_method, int num_weights, png_const_doublep filter_weights,
1543 png_const_doublep filter_costs))
1544 PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed,
1545 (png_structrp png_ptr, int heuristic_method, int num_weights,
1546 png_const_fixed_point_p filter_weights,
1547 png_const_fixed_point_p filter_costs))
1548 #endif /* WRITE_WEIGHTED_FILTER */
1549
1550 /* The following are no longer used and will be removed from libpng-1.7: */
1551 #define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */
1552 #define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */
1553 #define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */
1554 #define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */
1555
1556 /* Set the library compression level. Currently, valid values range from
1557 * 0 - 9, corresponding directly to the zlib compression levels 0 - 9
1558 * (0 - no compression, 9 - "maximal" compression). Note that tests have
1559 * shown that zlib compression levels 3-6 usually perform as well as level 9
1560 * for PNG images, and do considerably fewer caclulations. In the future,
1561 * these values may not correspond directly to the zlib compression levels.
1562 */
1563 #ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED
1564 PNG_EXPORT(69, void, png_set_compression_level, (png_structrp png_ptr,
1565 int level));
1566
1567 PNG_EXPORT(70, void, png_set_compression_mem_level, (png_structrp png_ptr,
1568 int mem_level));
1569
1570 PNG_EXPORT(71, void, png_set_compression_strategy, (png_structrp png_ptr,
1571 int strategy));
1572
1573 /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
1574 * smaller value of window_bits if it can do so safely.
1575 */
1576 PNG_EXPORT(72, void, png_set_compression_window_bits, (png_structrp png_ptr,
1577 int window_bits));
1578
1579 PNG_EXPORT(73, void, png_set_compression_method, (png_structrp png_ptr,
1580 int method));
1581 #endif /* WRITE_CUSTOMIZE_COMPRESSION */
1582
1583 #ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
1584 /* Also set zlib parameters for compressing non-IDAT chunks */
1585 PNG_EXPORT(222, void, png_set_text_compression_level, (png_structrp png_ptr,
1586 int level));
1587
1588 PNG_EXPORT(223, void, png_set_text_compression_mem_level, (png_structrp png_ptr,
1589 int mem_level));
1590
1591 PNG_EXPORT(224, void, png_set_text_compression_strategy, (png_structrp png_ptr,
1592 int strategy));
1593
1594 /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
1595 * smaller value of window_bits if it can do so safely.
1596 */
1597 PNG_EXPORT(225, void, png_set_text_compression_window_bits,
1598 (png_structrp png_ptr, int window_bits));
1599
1600 PNG_EXPORT(226, void, png_set_text_compression_method, (png_structrp png_ptr,
1601 int method));
1602 #endif /* WRITE_CUSTOMIZE_ZTXT_COMPRESSION */
1603 #endif /* WRITE */
1604
1605 /* These next functions are called for input/output, memory, and error
1606 * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c,
1607 * and call standard C I/O routines such as fread(), fwrite(), and
1608 * fprintf(). These functions can be made to use other I/O routines
1609 * at run time for those applications that need to handle I/O in a
1610 * different manner by calling png_set_???_fn(). See libpng-manual.txt for
1611 * more information.
1612 */
1613
1614 #ifdef PNG_STDIO_SUPPORTED
1615 /* Initialize the input/output for the PNG file to the default functions. */
1616 PNG_EXPORT(74, void, png_init_io, (png_structrp png_ptr, png_FILE_p fp));
1617 #endif
1618
1619 /* Replace the (error and abort), and warning functions with user
1620 * supplied functions. If no messages are to be printed you must still
1621 * write and use replacement functions. The replacement error_fn should
1622 * still do a longjmp to the last setjmp location if you are using this
1623 * method of error handling. If error_fn or warning_fn is NULL, the
1624 * default function will be used.
1625 */
1626
1627 PNG_EXPORT(75, void, png_set_error_fn, (png_structrp png_ptr,
1628 png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn));
1629
1630 /* Return the user pointer associated with the error functions */
1631 PNG_EXPORT(76, png_voidp, png_get_error_ptr, (png_const_structrp png_ptr));
1632
1633 /* Replace the default data output functions with a user supplied one(s).
1634 * If buffered output is not used, then output_flush_fn can be set to NULL.
1635 * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time
1636 * output_flush_fn will be ignored (and thus can be NULL).
1637 * It is probably a mistake to use NULL for output_flush_fn if
1638 * write_data_fn is not also NULL unless you have built libpng with
1639 * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's
1640 * default flush function, which uses the standard *FILE structure, will
1641 * be used.
1642 */
1643 PNG_EXPORT(77, void, png_set_write_fn, (png_structrp png_ptr, png_voidp io_ptr,
1644 png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn));
1645
1646 /* Replace the default data input function with a user supplied one. */
1647 PNG_EXPORT(78, void, png_set_read_fn, (png_structrp png_ptr, png_voidp io_ptr,
1648 png_rw_ptr read_data_fn));
1649
1650 /* Return the user pointer associated with the I/O functions */
1651 PNG_EXPORT(79, png_voidp, png_get_io_ptr, (png_const_structrp png_ptr));
1652
1653 PNG_EXPORT(80, void, png_set_read_status_fn, (png_structrp png_ptr,
1654 png_read_status_ptr read_row_fn));
1655
1656 PNG_EXPORT(81, void, png_set_write_status_fn, (png_structrp png_ptr,
1657 png_write_status_ptr write_row_fn));
1658
1659 #ifdef PNG_USER_MEM_SUPPORTED
1660 /* Replace the default memory allocation functions with user supplied one(s). */
1661 PNG_EXPORT(82, void, png_set_mem_fn, (png_structrp png_ptr, png_voidp mem_ptr,
1662 png_malloc_ptr malloc_fn, png_free_ptr free_fn));
1663 /* Return the user pointer associated with the memory functions */
1664 PNG_EXPORT(83, png_voidp, png_get_mem_ptr, (png_const_structrp png_ptr));
1665 #endif
1666
1667 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
1668 PNG_EXPORT(84, void, png_set_read_user_transform_fn, (png_structrp png_ptr,
1669 png_user_transform_ptr read_user_transform_fn));
1670 #endif
1671
1672 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
1673 PNG_EXPORT(85, void, png_set_write_user_transform_fn, (png_structrp png_ptr,
1674 png_user_transform_ptr write_user_transform_fn));
1675 #endif
1676
1677 #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
1678 PNG_EXPORT(86, void, png_set_user_transform_info, (png_structrp png_ptr,
1679 png_voidp user_transform_ptr, int user_transform_depth,
1680 int user_transform_channels));
1681 /* Return the user pointer associated with the user transform functions */
1682 PNG_EXPORT(87, png_voidp, png_get_user_transform_ptr,
1683 (png_const_structrp png_ptr));
1684 #endif
1685
1686 #ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED
1687 /* Return information about the row currently being processed. Note that these
1688 * APIs do not fail but will return unexpected results if called outside a user
1689 * transform callback. Also note that when transforming an interlaced image the
1690 * row number is the row number within the sub-image of the interlace pass, so
1691 * the value will increase to the height of the sub-image (not the full image)
1692 * then reset to 0 for the next pass.
1693 *
1694 * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
1695 * find the output pixel (x,y) given an interlaced sub-image pixel
1696 * (row,col,pass). (See below for these macros.)
1697 */
1698 PNG_EXPORT(217, png_uint_32, png_get_current_row_number, (png_const_structrp));
1699 PNG_EXPORT(218, png_byte, png_get_current_pass_number, (png_const_structrp));
1700 #endif
1701
1702 #ifdef PNG_READ_USER_CHUNKS_SUPPORTED
1703 /* This callback is called only for *unknown* chunks. If
1704 * PNG_HANDLE_AS_UNKNOWN_SUPPORTED is set then it is possible to set known
1705 * chunks to be treated as unknown, however in this case the callback must do
1706 * any processing required by the chunk (e.g. by calling the appropriate
1707 * png_set_ APIs.)
1708 *
1709 * There is no write support - on write, by default, all the chunks in the
1710 * 'unknown' list are written in the specified position.
1711 *
1712 * The integer return from the callback function is interpreted thus:
1713 *
1714 * negative: An error occurred; png_chunk_error will be called.
1715 * zero: The chunk was not handled, the chunk will be saved. A critical
1716 * chunk will cause an error at this point unless it is to be saved.
1717 * positive: The chunk was handled, libpng will ignore/discard it.
1718 *
1719 * See "INTERACTION WTIH USER CHUNK CALLBACKS" below for important notes about
1720 * how this behavior will change in libpng 1.7
1721 */
1722 PNG_EXPORT(88, void, png_set_read_user_chunk_fn, (png_structrp png_ptr,
1723 png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));
1724 #endif
1725
1726 #ifdef PNG_USER_CHUNKS_SUPPORTED
1727 PNG_EXPORT(89, png_voidp, png_get_user_chunk_ptr, (png_const_structrp png_ptr));
1728 #endif
1729
1730 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1731 /* Sets the function callbacks for the push reader, and a pointer to a
1732 * user-defined structure available to the callback functions.
1733 */
1734 PNG_EXPORT(90, void, png_set_progressive_read_fn, (png_structrp png_ptr,
1735 png_voidp progressive_ptr, png_progressive_info_ptr info_fn,
1736 png_progressive_row_ptr row_fn, png_progressive_end_ptr end_fn));
1737
1738 /* Returns the user pointer associated with the push read functions */
1739 PNG_EXPORT(91, png_voidp, png_get_progressive_ptr,
1740 (png_const_structrp png_ptr));
1741
1742 /* Function to be called when data becomes available */
1743 PNG_EXPORT(92, void, png_process_data, (png_structrp png_ptr,
1744 png_inforp info_ptr, png_bytep buffer, png_size_t buffer_size));
1745
1746 /* A function which may be called *only* within png_process_data to stop the
1747 * processing of any more data. The function returns the number of bytes
1748 * remaining, excluding any that libpng has cached internally. A subsequent
1749 * call to png_process_data must supply these bytes again. If the argument
1750 * 'save' is set to true the routine will first save all the pending data and
1751 * will always return 0.
1752 */
1753 PNG_EXPORT(219, png_size_t, png_process_data_pause, (png_structrp, int save));
1754
1755 /* A function which may be called *only* outside (after) a call to
1756 * png_process_data. It returns the number of bytes of data to skip in the
1757 * input. Normally it will return 0, but if it returns a non-zero value the
1758 * application must skip than number of bytes of input data and pass the
1759 * following data to the next call to png_process_data.
1760 */
1761 PNG_EXPORT(220, png_uint_32, png_process_data_skip, (png_structrp));
1762
1763 /* Function that combines rows. 'new_row' is a flag that should come from
1764 * the callback and be non-NULL if anything needs to be done; the library
1765 * stores its own version of the new data internally and ignores the passed
1766 * in value.
1767 */
1768 PNG_EXPORT(93, void, png_progressive_combine_row, (png_const_structrp png_ptr,
1769 png_bytep old_row, png_const_bytep new_row));
1770 #endif /* PROGRESSIVE_READ */
1771
1772 PNG_EXPORTA(94, png_voidp, png_malloc, (png_const_structrp png_ptr,
1773 png_alloc_size_t size), PNG_ALLOCATED);
1774 /* Added at libpng version 1.4.0 */
1775 PNG_EXPORTA(95, png_voidp, png_calloc, (png_const_structrp png_ptr,
1776 png_alloc_size_t size), PNG_ALLOCATED);
1777
1778 /* Added at libpng version 1.2.4 */
1779 PNG_EXPORTA(96, png_voidp, png_malloc_warn, (png_const_structrp png_ptr,
1780 png_alloc_size_t size), PNG_ALLOCATED);
1781
1782 /* Frees a pointer allocated by png_malloc() */
1783 PNG_EXPORT(97, void, png_free, (png_const_structrp png_ptr, png_voidp ptr));
1784
1785 /* Free data that was allocated internally */
1786 PNG_EXPORT(98, void, png_free_data, (png_const_structrp png_ptr,
1787 png_inforp info_ptr, png_uint_32 free_me, int num));
1788
1789 /* Reassign responsibility for freeing existing data, whether allocated
1790 * by libpng or by the application; this works on the png_info structure passed
1791 * in, it does not change the state for other png_info structures.
1792 *
1793 * It is unlikely that this function works correctly as of 1.6.0 and using it
1794 * may result either in memory leaks or double free of allocated data.
1795 */
1796 PNG_EXPORT(99, void, png_data_freer, (png_const_structrp png_ptr,
1797 png_inforp info_ptr, int freer, png_uint_32 mask));
1798
1799 /* Assignments for png_data_freer */
1800 #define PNG_DESTROY_WILL_FREE_DATA 1
1801 #define PNG_SET_WILL_FREE_DATA 1
1802 #define PNG_USER_WILL_FREE_DATA 2
1803 /* Flags for png_ptr->free_me and info_ptr->free_me */
1804 #define PNG_FREE_HIST 0x0008U
1805 #define PNG_FREE_ICCP 0x0010U
1806 #define PNG_FREE_SPLT 0x0020U
1807 #define PNG_FREE_ROWS 0x0040U
1808 #define PNG_FREE_PCAL 0x0080U
1809 #define PNG_FREE_SCAL 0x0100U
1810 #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
1811 # define PNG_FREE_UNKN 0x0200U
1812 #endif
1813 /* PNG_FREE_LIST 0x0400U removed in 1.6.0 because it is ignored */
1814 #define PNG_FREE_PLTE 0x1000U
1815 #define PNG_FREE_TRNS 0x2000U
1816 #define PNG_FREE_TEXT 0x4000U
1817 #define PNG_FREE_ALL 0x7fffU
1818 #define PNG_FREE_MUL 0x4220U /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */
1819
1820 #ifdef PNG_USER_MEM_SUPPORTED
1821 PNG_EXPORTA(100, png_voidp, png_malloc_default, (png_const_structrp png_ptr,
1822 png_alloc_size_t size), PNG_ALLOCATED PNG_DEPRECATED);
1823 PNG_EXPORTA(101, void, png_free_default, (png_const_structrp png_ptr,
1824 png_voidp ptr), PNG_DEPRECATED);
1825 #endif
1826
1827 #ifdef PNG_ERROR_TEXT_SUPPORTED
1828 /* Fatal error in PNG image of libpng - can't continue */
1829 PNG_EXPORTA(102, void, png_error, (png_const_structrp png_ptr,
1830 png_const_charp error_message), PNG_NORETURN);
1831
1832 /* The same, but the chunk name is prepended to the error string. */
1833 PNG_EXPORTA(103, void, png_chunk_error, (png_const_structrp png_ptr,
1834 png_const_charp error_message), PNG_NORETURN);
1835
1836 #else
1837 /* Fatal error in PNG image of libpng - can't continue */
1838 PNG_EXPORTA(104, void, png_err, (png_const_structrp png_ptr), PNG_NORETURN);
1839 # define png_error(s1,s2) png_err(s1)
1840 # define png_chunk_error(s1,s2) png_err(s1)
1841 #endif
1842
1843 #ifdef PNG_WARNINGS_SUPPORTED
1844 /* Non-fatal error in libpng. Can continue, but may have a problem. */
1845 PNG_EXPORT(105, void, png_warning, (png_const_structrp png_ptr,
1846 png_const_charp warning_message));
1847
1848 /* Non-fatal error in libpng, chunk name is prepended to message. */
1849 PNG_EXPORT(106, void, png_chunk_warning, (png_const_structrp png_ptr,
1850 png_const_charp warning_message));
1851 #else
1852 # define png_warning(s1,s2) ((void)(s1))
1853 # define png_chunk_warning(s1,s2) ((void)(s1))
1854 #endif
1855
1856 #ifdef PNG_BENIGN_ERRORS_SUPPORTED
1857 /* Benign error in libpng. Can continue, but may have a problem.
1858 * User can choose whether to handle as a fatal error or as a warning. */
1859 PNG_EXPORT(107, void, png_benign_error, (png_const_structrp png_ptr,
1860 png_const_charp warning_message));
1861
1862 #ifdef PNG_READ_SUPPORTED
1863 /* Same, chunk name is prepended to message (only during read) */
1864 PNG_EXPORT(108, void, png_chunk_benign_error, (png_const_structrp png_ptr,
1865 png_const_charp warning_message));
1866 #endif
1867
1868 PNG_EXPORT(109, void, png_set_benign_errors,
1869 (png_structrp png_ptr, int allowed));
1870 #else
1871 # ifdef PNG_ALLOW_BENIGN_ERRORS
1872 # define png_benign_error png_warning
1873 # define png_chunk_benign_error png_chunk_warning
1874 # else
1875 # define png_benign_error png_error
1876 # define png_chunk_benign_error png_chunk_error
1877 # endif
1878 #endif
1879
1880 /* The png_set_<chunk> functions are for storing values in the png_info_struct.
1881 * Similarly, the png_get_<chunk> calls are used to read values from the
1882 * png_info_struct, either storing the parameters in the passed variables, or
1883 * setting pointers into the png_info_struct where the data is stored. The
1884 * png_get_<chunk> functions return a non-zero value if the data was available
1885 * in info_ptr, or return zero and do not change any of the parameters if the
1886 * data was not available.
1887 *
1888 * These functions should be used instead of directly accessing png_info
1889 * to avoid problems with future changes in the size and internal layout of
1890 * png_info_struct.
1891 */
1892 /* Returns "flag" if chunk data is valid in info_ptr. */
1893 PNG_EXPORT(110, png_uint_32, png_get_valid, (png_const_structrp png_ptr,
1894 png_const_inforp info_ptr, png_uint_32 flag));
1895
1896 /* Returns number of bytes needed to hold a transformed row. */
1897 PNG_EXPORT(111, png_size_t, png_get_rowbytes, (png_const_structrp png_ptr,
1898 png_const_inforp info_ptr));
1899
1900 #ifdef PNG_INFO_IMAGE_SUPPORTED
1901 /* Returns row_pointers, which is an array of pointers to scanlines that was
1902 * returned from png_read_png().
1903 */
1904 PNG_EXPORT(112, png_bytepp, png_get_rows, (png_const_structrp png_ptr,
1905 png_const_inforp info_ptr));
1906
1907 /* Set row_pointers, which is an array of pointers to scanlines for use
1908 * by png_write_png().
1909 */
1910 PNG_EXPORT(113, void, png_set_rows, (png_const_structrp png_ptr,
1911 png_inforp info_ptr, png_bytepp row_pointers));
1912 #endif
1913
1914 /* Returns number of color channels in image. */
1915 PNG_EXPORT(114, png_byte, png_get_channels, (png_const_structrp png_ptr,
1916 png_const_inforp info_ptr));
1917
1918 #ifdef PNG_EASY_ACCESS_SUPPORTED
1919 /* Returns image width in pixels. */
1920 PNG_EXPORT(115, png_uint_32, png_get_image_width, (png_const_structrp png_ptr,
1921 png_const_inforp info_ptr));
1922
1923 /* Returns image height in pixels. */
1924 PNG_EXPORT(116, png_uint_32, png_get_image_height, (png_const_structrp png_ptr,
1925 png_const_inforp info_ptr));
1926
1927 /* Returns image bit_depth. */
1928 PNG_EXPORT(117, png_byte, png_get_bit_depth, (png_const_structrp png_ptr,
1929 png_const_inforp info_ptr));
1930
1931 /* Returns image color_type. */
1932 PNG_EXPORT(118, png_byte, png_get_color_type, (png_const_structrp png_ptr,
1933 png_const_inforp info_ptr));
1934
1935 /* Returns image filter_type. */
1936 PNG_EXPORT(119, png_byte, png_get_filter_type, (png_const_structrp png_ptr,
1937 png_const_inforp info_ptr));
1938
1939 /* Returns image interlace_type. */
1940 PNG_EXPORT(120, png_byte, png_get_interlace_type, (png_const_structrp png_ptr,
1941 png_const_inforp info_ptr));
1942
1943 /* Returns image compression_type. */
1944 PNG_EXPORT(121, png_byte, png_get_compression_type, (png_const_structrp png_ptr,
1945 png_const_inforp info_ptr));
1946
1947 /* Returns image resolution in pixels per meter, from pHYs chunk data. */
1948 PNG_EXPORT(122, png_uint_32, png_get_pixels_per_meter,
1949 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1950 PNG_EXPORT(123, png_uint_32, png_get_x_pixels_per_meter,
1951 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1952 PNG_EXPORT(124, png_uint_32, png_get_y_pixels_per_meter,
1953 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1954
1955 /* Returns pixel aspect ratio, computed from pHYs chunk data. */
1956 PNG_FP_EXPORT(125, float, png_get_pixel_aspect_ratio,
1957 (png_const_structrp png_ptr, png_const_inforp info_ptr))
1958 PNG_FIXED_EXPORT(210, png_fixed_point, png_get_pixel_aspect_ratio_fixed,
1959 (png_const_structrp png_ptr, png_const_inforp info_ptr))
1960
1961 /* Returns image x, y offset in pixels or microns, from oFFs chunk data. */
1962 PNG_EXPORT(126, png_int_32, png_get_x_offset_pixels,
1963 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1964 PNG_EXPORT(127, png_int_32, png_get_y_offset_pixels,
1965 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1966 PNG_EXPORT(128, png_int_32, png_get_x_offset_microns,
1967 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1968 PNG_EXPORT(129, png_int_32, png_get_y_offset_microns,
1969 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1970
1971 #endif /* EASY_ACCESS */
1972
1973 #ifdef PNG_READ_SUPPORTED
1974 /* Returns pointer to signature string read from PNG header */
1975 PNG_EXPORT(130, png_const_bytep, png_get_signature, (png_const_structrp png_ptr,
1976 png_const_inforp info_ptr));
1977 #endif
1978
1979 #ifdef PNG_bKGD_SUPPORTED
1980 PNG_EXPORT(131, png_uint_32, png_get_bKGD, (png_const_structrp png_ptr,
1981 png_inforp info_ptr, png_color_16p *background));
1982 #endif
1983
1984 #ifdef PNG_bKGD_SUPPORTED
1985 PNG_EXPORT(132, void, png_set_bKGD, (png_const_structrp png_ptr,
1986 png_inforp info_ptr, png_const_color_16p background));
1987 #endif
1988
1989 #ifdef PNG_cHRM_SUPPORTED
1990 PNG_FP_EXPORT(133, png_uint_32, png_get_cHRM, (png_const_structrp png_ptr,
1991 png_const_inforp info_ptr, double *white_x, double *white_y, double *red_x,
1992 double *red_y, double *green_x, double *green_y, double *blue_x,
1993 double *blue_y))
1994 PNG_FP_EXPORT(230, png_uint_32, png_get_cHRM_XYZ, (png_const_structrp png_ptr,
1995 png_const_inforp info_ptr, double *red_X, double *red_Y, double *red_Z,
1996 double *green_X, double *green_Y, double *green_Z, double *blue_X,
1997 double *blue_Y, double *blue_Z))
1998 PNG_FIXED_EXPORT(134, png_uint_32, png_get_cHRM_fixed,
1999 (png_const_structrp png_ptr, png_const_inforp info_ptr,
2000 png_fixed_point *int_white_x, png_fixed_point *int_white_y,
2001 png_fixed_point *int_red_x, png_fixed_point *int_red_y,
2002 png_fixed_point *int_green_x, png_fixed_point *int_green_y,
2003 png_fixed_point *int_blue_x, png_fixed_point *int_blue_y))
2004 PNG_FIXED_EXPORT(231, png_uint_32, png_get_cHRM_XYZ_fixed,
2005 (png_const_structrp png_ptr, png_const_inforp info_ptr,
2006 png_fixed_point *int_red_X, png_fixed_point *int_red_Y,
2007 png_fixed_point *int_red_Z, png_fixed_point *int_green_X,
2008 png_fixed_point *int_green_Y, png_fixed_point *int_green_Z,
2009 png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y,
2010 png_fixed_point *int_blue_Z))
2011 #endif
2012
2013 #ifdef PNG_cHRM_SUPPORTED
2014 PNG_FP_EXPORT(135, void, png_set_cHRM, (png_const_structrp png_ptr,
2015 png_inforp info_ptr,
2016 double white_x, double white_y, double red_x, double red_y, double green_x,
2017 double green_y, double blue_x, double blue_y))
2018 PNG_FP_EXPORT(232, void, png_set_cHRM_XYZ, (png_const_structrp png_ptr,
2019 png_inforp info_ptr, double red_X, double red_Y, double red_Z,
2020 double green_X, double green_Y, double green_Z, double blue_X,
2021 double blue_Y, double blue_Z))
2022 PNG_FIXED_EXPORT(136, void, png_set_cHRM_fixed, (png_const_structrp png_ptr,
2023 png_inforp info_ptr, png_fixed_point int_white_x,
2024 png_fixed_point int_white_y, png_fixed_point int_red_x,
2025 png_fixed_point int_red_y, png_fixed_point int_green_x,
2026 png_fixed_point int_green_y, png_fixed_point int_blue_x,
2027 png_fixed_point int_blue_y))
2028 PNG_FIXED_EXPORT(233, void, png_set_cHRM_XYZ_fixed, (png_const_structrp png_ptr,
2029 png_inforp info_ptr, png_fixed_point int_red_X, png_fixed_point int_red_Y,
2030 png_fixed_point int_red_Z, png_fixed_point int_green_X,
2031 png_fixed_point int_green_Y, png_fixed_point int_green_Z,
2032 png_fixed_point int_blue_X, png_fixed_point int_blue_Y,
2033 png_fixed_point int_blue_Z))
2034 #endif
2035
2036 #ifdef PNG_gAMA_SUPPORTED
2037 PNG_FP_EXPORT(137, png_uint_32, png_get_gAMA, (png_const_structrp png_ptr,
2038 png_const_inforp info_ptr, double *file_gamma))
2039 PNG_FIXED_EXPORT(138, png_uint_32, png_get_gAMA_fixed,
2040 (png_const_structrp png_ptr, png_const_inforp info_ptr,
2041 png_fixed_point *int_file_gamma))
2042 #endif
2043
2044 #ifdef PNG_gAMA_SUPPORTED
2045 PNG_FP_EXPORT(139, void, png_set_gAMA, (png_const_structrp png_ptr,
2046 png_inforp info_ptr, double file_gamma))
2047 PNG_FIXED_EXPORT(140, void, png_set_gAMA_fixed, (png_const_structrp png_ptr,
2048 png_inforp info_ptr, png_fixed_point int_file_gamma))
2049 #endif
2050
2051 #ifdef PNG_hIST_SUPPORTED
2052 PNG_EXPORT(141, png_uint_32, png_get_hIST, (png_const_structrp png_ptr,
2053 png_inforp info_ptr, png_uint_16p *hist));
2054 #endif
2055
2056 #ifdef PNG_hIST_SUPPORTED
2057 PNG_EXPORT(142, void, png_set_hIST, (png_const_structrp png_ptr,
2058 png_inforp info_ptr, png_const_uint_16p hist));
2059 #endif
2060
2061 PNG_EXPORT(143, png_uint_32, png_get_IHDR, (png_const_structrp png_ptr,
2062 png_const_inforp info_ptr, png_uint_32 *width, png_uint_32 *height,
2063 int *bit_depth, int *color_type, int *interlace_method,
2064 int *compression_method, int *filter_method));
2065
2066 PNG_EXPORT(144, void, png_set_IHDR, (png_const_structrp png_ptr,
2067 png_inforp info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth,
2068 int color_type, int interlace_method, int compression_method,
2069 int filter_method));
2070
2071 #ifdef PNG_oFFs_SUPPORTED
2072 PNG_EXPORT(145, png_uint_32, png_get_oFFs, (png_const_structrp png_ptr,
2073 png_const_inforp info_ptr, png_int_32 *offset_x, png_int_32 *offset_y,
2074 int *unit_type));
2075 #endif
2076
2077 #ifdef PNG_oFFs_SUPPORTED
2078 PNG_EXPORT(146, void, png_set_oFFs, (png_const_structrp png_ptr,
2079 png_inforp info_ptr, png_int_32 offset_x, png_int_32 offset_y,
2080 int unit_type));
2081 #endif
2082
2083 #ifdef PNG_pCAL_SUPPORTED
2084 PNG_EXPORT(147, png_uint_32, png_get_pCAL, (png_const_structrp png_ptr,
2085 png_inforp info_ptr, png_charp *purpose, png_int_32 *X0,
2086 png_int_32 *X1, int *type, int *nparams, png_charp *units,
2087 png_charpp *params));
2088 #endif
2089
2090 #ifdef PNG_pCAL_SUPPORTED
2091 PNG_EXPORT(148, void, png_set_pCAL, (png_const_structrp png_ptr,
2092 png_inforp info_ptr, png_const_charp purpose, png_int_32 X0, png_int_32 X1,
2093 int type, int nparams, png_const_charp units, png_charpp params));
2094 #endif
2095
2096 #ifdef PNG_pHYs_SUPPORTED
2097 PNG_EXPORT(149, png_uint_32, png_get_pHYs, (png_const_structrp png_ptr,
2098 png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y,
2099 int *unit_type));
2100 #endif
2101
2102 #ifdef PNG_pHYs_SUPPORTED
2103 PNG_EXPORT(150, void, png_set_pHYs, (png_const_structrp png_ptr,
2104 png_inforp info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type));
2105 #endif
2106
2107 PNG_EXPORT(151, png_uint_32, png_get_PLTE, (png_const_structrp png_ptr,
2108 png_inforp info_ptr, png_colorp *palette, int *num_palette));
2109
2110 PNG_EXPORT(152, void, png_set_PLTE, (png_structrp png_ptr,
2111 png_inforp info_ptr, png_const_colorp palette, int num_palette));
2112
2113 #ifdef PNG_sBIT_SUPPORTED
2114 PNG_EXPORT(153, png_uint_32, png_get_sBIT, (png_const_structrp png_ptr,
2115 png_inforp info_ptr, png_color_8p *sig_bit));
2116 #endif
2117
2118 #ifdef PNG_sBIT_SUPPORTED
2119 PNG_EXPORT(154, void, png_set_sBIT, (png_const_structrp png_ptr,
2120 png_inforp info_ptr, png_const_color_8p sig_bit));
2121 #endif
2122
2123 #ifdef PNG_sRGB_SUPPORTED
2124 PNG_EXPORT(155, png_uint_32, png_get_sRGB, (png_const_structrp png_ptr,
2125 png_const_inforp info_ptr, int *file_srgb_intent));
2126 #endif
2127
2128 #ifdef PNG_sRGB_SUPPORTED
2129 PNG_EXPORT(156, void, png_set_sRGB, (png_const_structrp png_ptr,
2130 png_inforp info_ptr, int srgb_intent));
2131 PNG_EXPORT(157, void, png_set_sRGB_gAMA_and_cHRM, (png_const_structrp png_ptr,
2132 png_inforp info_ptr, int srgb_intent));
2133 #endif
2134
2135 #ifdef PNG_iCCP_SUPPORTED
2136 PNG_EXPORT(158, png_uint_32, png_get_iCCP, (png_const_structrp png_ptr,
2137 png_inforp info_ptr, png_charpp name, int *compression_type,
2138 png_bytepp profile, png_uint_32 *proflen));
2139 #endif
2140
2141 #ifdef PNG_iCCP_SUPPORTED
2142 PNG_EXPORT(159, void, png_set_iCCP, (png_const_structrp png_ptr,
2143 png_inforp info_ptr, png_const_charp name, int compression_type,
2144 png_const_bytep profile, png_uint_32 proflen));
2145 #endif
2146
2147 #ifdef PNG_sPLT_SUPPORTED
2148 PNG_EXPORT(160, int, png_get_sPLT, (png_const_structrp png_ptr,
2149 png_inforp info_ptr, png_sPLT_tpp entries));
2150 #endif
2151
2152 #ifdef PNG_sPLT_SUPPORTED
2153 PNG_EXPORT(161, void, png_set_sPLT, (png_const_structrp png_ptr,
2154 png_inforp info_ptr, png_const_sPLT_tp entries, int nentries));
2155 #endif
2156
2157 #ifdef PNG_TEXT_SUPPORTED
2158 /* png_get_text also returns the number of text chunks in *num_text */
2159 PNG_EXPORT(162, int, png_get_text, (png_const_structrp png_ptr,
2160 png_inforp info_ptr, png_textp *text_ptr, int *num_text));
2161 #endif
2162
2163 /* Note while png_set_text() will accept a structure whose text,
2164 * language, and translated keywords are NULL pointers, the structure
2165 * returned by png_get_text will always contain regular
2166 * zero-terminated C strings. They might be empty strings but
2167 * they will never be NULL pointers.
2168 */
2169
2170 #ifdef PNG_TEXT_SUPPORTED
2171 PNG_EXPORT(163, void, png_set_text, (png_const_structrp png_ptr,
2172 png_inforp info_ptr, png_const_textp text_ptr, int num_text));
2173 #endif
2174
2175 #ifdef PNG_tIME_SUPPORTED
2176 PNG_EXPORT(164, png_uint_32, png_get_tIME, (png_const_structrp png_ptr,
2177 png_inforp info_ptr, png_timep *mod_time));
2178 #endif
2179
2180 #ifdef PNG_tIME_SUPPORTED
2181 PNG_EXPORT(165, void, png_set_tIME, (png_const_structrp png_ptr,
2182 png_inforp info_ptr, png_const_timep mod_time));
2183 #endif
2184
2185 #ifdef PNG_tRNS_SUPPORTED
2186 PNG_EXPORT(166, png_uint_32, png_get_tRNS, (png_const_structrp png_ptr,
2187 png_inforp info_ptr, png_bytep *trans_alpha, int *num_trans,
2188 png_color_16p *trans_color));
2189 #endif
2190
2191 #ifdef PNG_tRNS_SUPPORTED
2192 PNG_EXPORT(167, void, png_set_tRNS, (png_structrp png_ptr,
2193 png_inforp info_ptr, png_const_bytep trans_alpha, int num_trans,
2194 png_const_color_16p trans_color));
2195 #endif
2196
2197 #ifdef PNG_sCAL_SUPPORTED
2198 PNG_FP_EXPORT(168, png_uint_32, png_get_sCAL, (png_const_structrp png_ptr,
2199 png_const_inforp info_ptr, int *unit, double *width, double *height))
2200 #if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || \
2201 defined(PNG_FLOATING_POINT_SUPPORTED)
2202 /* NOTE: this API is currently implemented using floating point arithmetic,
2203 * consequently it can only be used on systems with floating point support.
2204 * In any case the range of values supported by png_fixed_point is small and it
2205 * is highly recommended that png_get_sCAL_s be used instead.
2206 */
2207 PNG_FIXED_EXPORT(214, png_uint_32, png_get_sCAL_fixed,
2208 (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit,
2209 png_fixed_point *width, png_fixed_point *height))
2210 #endif
2211 PNG_EXPORT(169, png_uint_32, png_get_sCAL_s,
2212 (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit,
2213 png_charpp swidth, png_charpp sheight));
2214
2215 PNG_FP_EXPORT(170, void, png_set_sCAL, (png_const_structrp png_ptr,
2216 png_inforp info_ptr, int unit, double width, double height))
2217 PNG_FIXED_EXPORT(213, void, png_set_sCAL_fixed, (png_const_structrp png_ptr,
2218 png_inforp info_ptr, int unit, png_fixed_point width,
2219 png_fixed_point height))
2220 PNG_EXPORT(171, void, png_set_sCAL_s, (png_const_structrp png_ptr,
2221 png_inforp info_ptr, int unit,
2222 png_const_charp swidth, png_const_charp sheight));
2223 #endif /* sCAL */
2224
2225 #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
2226 /* Provide the default handling for all unknown chunks or, optionally, for
2227 * specific unknown chunks.
2228 *
2229 * NOTE: prior to 1.6.0 the handling specified for particular chunks on read was
2230 * ignored and the default was used, the per-chunk setting only had an effect on
2231 * write. If you wish to have chunk-specific handling on read in code that must
2232 * work on earlier versions you must use a user chunk callback to specify the
2233 * desired handling (keep or discard.)
2234 *
2235 * The 'keep' parameter is a PNG_HANDLE_CHUNK_ value as listed below. The
2236 * parameter is interpreted as follows:
2237 *
2238 * READ:
2239 * PNG_HANDLE_CHUNK_AS_DEFAULT:
2240 * Known chunks: do normal libpng processing, do not keep the chunk (but
2241 * see the comments below about PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
2242 * Unknown chunks: for a specific chunk use the global default, when used
2243 * as the default discard the chunk data.
2244 * PNG_HANDLE_CHUNK_NEVER:
2245 * Discard the chunk data.
2246 * PNG_HANDLE_CHUNK_IF_SAFE:
2247 * Keep the chunk data if the chunk is not critical else raise a chunk
2248 * error.
2249 * PNG_HANDLE_CHUNK_ALWAYS:
2250 * Keep the chunk data.
2251 *
2252 * If the chunk data is saved it can be retrieved using png_get_unknown_chunks,
2253 * below. Notice that specifying "AS_DEFAULT" as a global default is equivalent
2254 * to specifying "NEVER", however when "AS_DEFAULT" is used for specific chunks
2255 * it simply resets the behavior to the libpng default.
2256 *
2257 * INTERACTION WTIH USER CHUNK CALLBACKS:
2258 * The per-chunk handling is always used when there is a png_user_chunk_ptr
2259 * callback and the callback returns 0; the chunk is then always stored *unless*
2260 * it is critical and the per-chunk setting is other than ALWAYS. Notice that
2261 * the global default is *not* used in this case. (In effect the per-chunk
2262 * value is incremented to at least IF_SAFE.)
2263 *
2264 * IMPORTANT NOTE: this behavior will change in libpng 1.7 - the global and
2265 * per-chunk defaults will be honored. If you want to preserve the current
2266 * behavior when your callback returns 0 you must set PNG_HANDLE_CHUNK_IF_SAFE
2267 * as the default - if you don't do this libpng 1.6 will issue a warning.
2268 *
2269 * If you want unhandled unknown chunks to be discarded in libpng 1.6 and
2270 * earlier simply return '1' (handled).
2271 *
2272 * PNG_HANDLE_AS_UNKNOWN_SUPPORTED:
2273 * If this is *not* set known chunks will always be handled by libpng and
2274 * will never be stored in the unknown chunk list. Known chunks listed to
2275 * png_set_keep_unknown_chunks will have no effect. If it is set then known
2276 * chunks listed with a keep other than AS_DEFAULT will *never* be processed
2277 * by libpng, in addition critical chunks must either be processed by the
2278 * callback or saved.
2279 *
2280 * The IHDR and IEND chunks must not be listed. Because this turns off the
2281 * default handling for chunks that would otherwise be recognized the
2282 * behavior of libpng transformations may well become incorrect!
2283 *
2284 * WRITE:
2285 * When writing chunks the options only apply to the chunks specified by
2286 * png_set_unknown_chunks (below), libpng will *always* write known chunks
2287 * required by png_set_ calls and will always write the core critical chunks
2288 * (as required for PLTE).
2289 *
2290 * Each chunk in the png_set_unknown_chunks list is looked up in the
2291 * png_set_keep_unknown_chunks list to find the keep setting, this is then
2292 * interpreted as follows:
2293 *
2294 * PNG_HANDLE_CHUNK_AS_DEFAULT:
2295 * Write safe-to-copy chunks and write other chunks if the global
2296 * default is set to _ALWAYS, otherwise don't write this chunk.
2297 * PNG_HANDLE_CHUNK_NEVER:
2298 * Do not write the chunk.
2299 * PNG_HANDLE_CHUNK_IF_SAFE:
2300 * Write the chunk if it is safe-to-copy, otherwise do not write it.
2301 * PNG_HANDLE_CHUNK_ALWAYS:
2302 * Write the chunk.
2303 *
2304 * Note that the default behavior is effectively the opposite of the read case -
2305 * in read unknown chunks are not stored by default, in write they are written
2306 * by default. Also the behavior of PNG_HANDLE_CHUNK_IF_SAFE is very different
2307 * - on write the safe-to-copy bit is checked, on read the critical bit is
2308 * checked and on read if the chunk is critical an error will be raised.
2309 *
2310 * num_chunks:
2311 * ===========
2312 * If num_chunks is positive, then the "keep" parameter specifies the manner
2313 * for handling only those chunks appearing in the chunk_list array,
2314 * otherwise the chunk list array is ignored.
2315 *
2316 * If num_chunks is 0 the "keep" parameter specifies the default behavior for
2317 * unknown chunks, as described above.
2318 *
2319 * If num_chunks is negative, then the "keep" parameter specifies the manner
2320 * for handling all unknown chunks plus all chunks recognized by libpng
2321 * except for the IHDR, PLTE, tRNS, IDAT, and IEND chunks (which continue to
2322 * be processed by libpng.
2323 */
2324 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
2325 PNG_EXPORT(172, void, png_set_keep_unknown_chunks, (png_structrp png_ptr,
2326 int keep, png_const_bytep chunk_list, int num_chunks));
2327 #endif /* HANDLE_AS_UNKNOWN */
2328
2329 /* The "keep" PNG_HANDLE_CHUNK_ parameter for the specified chunk is returned;
2330 * the result is therefore true (non-zero) if special handling is required,
2331 * false for the default handling.
2332 */
2333 PNG_EXPORT(173, int, png_handle_as_unknown, (png_const_structrp png_ptr,
2334 png_const_bytep chunk_name));
2335 #endif /* SET_UNKNOWN_CHUNKS */
2336
2337 #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
2338 PNG_EXPORT(174, void, png_set_unknown_chunks, (png_const_structrp png_ptr,
2339 png_inforp info_ptr, png_const_unknown_chunkp unknowns,
2340 int num_unknowns));
2341 /* NOTE: prior to 1.6.0 this routine set the 'location' field of the added
2342 * unknowns to the location currently stored in the png_struct. This is
2343 * invariably the wrong value on write. To fix this call the following API
2344 * for each chunk in the list with the correct location. If you know your
2345 * code won't be compiled on earlier versions you can rely on
2346 * png_set_unknown_chunks(write-ptr, png_get_unknown_chunks(read-ptr)) doing
2347 * the correct thing.
2348 */
2349
2350 PNG_EXPORT(175, void, png_set_unknown_chunk_location,
2351 (png_const_structrp png_ptr, png_inforp info_ptr, int chunk, int location));
2352
2353 PNG_EXPORT(176, int, png_get_unknown_chunks, (png_const_structrp png_ptr,
2354 png_inforp info_ptr, png_unknown_chunkpp entries));
2355 #endif
2356
2357 /* Png_free_data() will turn off the "valid" flag for anything it frees.
2358 * If you need to turn it off for a chunk that your application has freed,
2359 * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK);
2360 */
2361 PNG_EXPORT(177, void, png_set_invalid, (png_const_structrp png_ptr,
2362 png_inforp info_ptr, int mask));
2363
2364 #ifdef PNG_INFO_IMAGE_SUPPORTED
2365 /* The "params" pointer is currently not used and is for future expansion. */
2366 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
2367 PNG_EXPORT(178, void, png_read_png, (png_structrp png_ptr, png_inforp info_ptr,
2368 int transforms, png_voidp params));
2369 #endif
2370 #ifdef PNG_WRITE_SUPPORTED
2371 PNG_EXPORT(179, void, png_write_png, (png_structrp png_ptr, png_inforp info_ptr,
2372 int transforms, png_voidp params));
2373 #endif
2374 #endif
2375
2376 PNG_EXPORT(180, png_const_charp, png_get_copyright,
2377 (png_const_structrp png_ptr));
2378 PNG_EXPORT(181, png_const_charp, png_get_header_ver,
2379 (png_const_structrp png_ptr));
2380 PNG_EXPORT(182, png_const_charp, png_get_header_version,
2381 (png_const_structrp png_ptr));
2382 PNG_EXPORT(183, png_const_charp, png_get_libpng_ver,
2383 (png_const_structrp png_ptr));
2384
2385 #ifdef PNG_MNG_FEATURES_SUPPORTED
2386 PNG_EXPORT(184, png_uint_32, png_permit_mng_features, (png_structrp png_ptr,
2387 png_uint_32 mng_features_permitted));
2388 #endif
2389
2390 /* For use in png_set_keep_unknown, added to version 1.2.6 */
2391 #define PNG_HANDLE_CHUNK_AS_DEFAULT 0
2392 #define PNG_HANDLE_CHUNK_NEVER 1
2393 #define PNG_HANDLE_CHUNK_IF_SAFE 2
2394 #define PNG_HANDLE_CHUNK_ALWAYS 3
2395 #define PNG_HANDLE_CHUNK_LAST 4
2396
2397 /* Strip the prepended error numbers ("#nnn ") from error and warning
2398 * messages before passing them to the error or warning handler.
2399 */
2400 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
2401 PNG_EXPORT(185, void, png_set_strip_error_numbers, (png_structrp png_ptr,
2402 png_uint_32 strip_mode));
2403 #endif
2404
2405 /* Added in libpng-1.2.6 */
2406 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
2407 PNG_EXPORT(186, void, png_set_user_limits, (png_structrp png_ptr,
2408 png_uint_32 user_width_max, png_uint_32 user_height_max));
2409 PNG_EXPORT(187, png_uint_32, png_get_user_width_max,
2410 (png_const_structrp png_ptr));
2411 PNG_EXPORT(188, png_uint_32, png_get_user_height_max,
2412 (png_const_structrp png_ptr));
2413 /* Added in libpng-1.4.0 */
2414 PNG_EXPORT(189, void, png_set_chunk_cache_max, (png_structrp png_ptr,
2415 png_uint_32 user_chunk_cache_max));
2416 PNG_EXPORT(190, png_uint_32, png_get_chunk_cache_max,
2417 (png_const_structrp png_ptr));
2418 /* Added in libpng-1.4.1 */
2419 PNG_EXPORT(191, void, png_set_chunk_malloc_max, (png_structrp png_ptr,
2420 png_alloc_size_t user_chunk_cache_max));
2421 PNG_EXPORT(192, png_alloc_size_t, png_get_chunk_malloc_max,
2422 (png_const_structrp png_ptr));
2423 #endif
2424
2425 #if defined(PNG_INCH_CONVERSIONS_SUPPORTED)
2426 PNG_EXPORT(193, png_uint_32, png_get_pixels_per_inch,
2427 (png_const_structrp png_ptr, png_const_inforp info_ptr));
2428
2429 PNG_EXPORT(194, png_uint_32, png_get_x_pixels_per_inch,
2430 (png_const_structrp png_ptr, png_const_inforp info_ptr));
2431
2432 PNG_EXPORT(195, png_uint_32, png_get_y_pixels_per_inch,
2433 (png_const_structrp png_ptr, png_const_inforp info_ptr));
2434
2435 PNG_FP_EXPORT(196, float, png_get_x_offset_inches,
2436 (png_const_structrp png_ptr, png_const_inforp info_ptr))
2437 #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */
2438 PNG_FIXED_EXPORT(211, png_fixed_point, png_get_x_offset_inches_fixed,
2439 (png_const_structrp png_ptr, png_const_inforp info_ptr))
2440 #endif
2441
2442 PNG_FP_EXPORT(197, float, png_get_y_offset_inches, (png_const_structrp png_ptr,
2443 png_const_inforp info_ptr))
2444 #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */
2445 PNG_FIXED_EXPORT(212, png_fixed_point, png_get_y_offset_inches_fixed,
2446 (png_const_structrp png_ptr, png_const_inforp info_ptr))
2447 #endif
2448
2449 # ifdef PNG_pHYs_SUPPORTED
2450 PNG_EXPORT(198, png_uint_32, png_get_pHYs_dpi, (png_const_structrp png_ptr,
2451 png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y,
2452 int *unit_type));
2453 # endif /* pHYs */
2454 #endif /* INCH_CONVERSIONS */
2455
2456 /* Added in libpng-1.4.0 */
2457 #ifdef PNG_IO_STATE_SUPPORTED
2458 PNG_EXPORT(199, png_uint_32, png_get_io_state, (png_const_structrp png_ptr));
2459
2460 /* Removed from libpng 1.6; use png_get_io_chunk_type. */
2461 PNG_REMOVED(200, png_const_bytep, png_get_io_chunk_name, (png_structrp png_ptr),
2462 PNG_DEPRECATED)
2463
2464 PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type,
2465 (png_const_structrp png_ptr));
2466
2467 /* The flags returned by png_get_io_state() are the following: */
2468 # define PNG_IO_NONE 0x0000 /* no I/O at this moment */
2469 # define PNG_IO_READING 0x0001 /* currently reading */
2470 # define PNG_IO_WRITING 0x0002 /* currently writing */
2471 # define PNG_IO_SIGNATURE 0x0010 /* currently at the file signature */
2472 # define PNG_IO_CHUNK_HDR 0x0020 /* currently at the chunk header */
2473 # define PNG_IO_CHUNK_DATA 0x0040 /* currently at the chunk data */
2474 # define PNG_IO_CHUNK_CRC 0x0080 /* currently at the chunk crc */
2475 # define PNG_IO_MASK_OP 0x000f /* current operation: reading/writing */
2476 # define PNG_IO_MASK_LOC 0x00f0 /* current location: sig/hdr/data/crc */
2477 #endif /* IO_STATE */
2478
2479 /* Interlace support. The following macros are always defined so that if
2480 * libpng interlace handling is turned off the macros may be used to handle
2481 * interlaced images within the application.
2482 */
2483 #define PNG_INTERLACE_ADAM7_PASSES 7
2484
2485 /* Two macros to return the first row and first column of the original,
2486 * full, image which appears in a given pass. 'pass' is in the range 0
2487 * to 6 and the result is in the range 0 to 7.
2488 */
2489 #define PNG_PASS_START_ROW(pass) (((1&~(pass))<<(3-((pass)>>1)))&7)
2490 #define PNG_PASS_START_COL(pass) (((1& (pass))<<(3-(((pass)+1)>>1)))&7)
2491
2492 /* A macro to return the offset between pixels in the output row for a pair of
2493 * pixels in the input - effectively the inverse of the 'COL_SHIFT' macro that
2494 * follows. Note that ROW_OFFSET is the offset from one row to the next whereas
2495 * COL_OFFSET is from one column to the next, within a row.
2496 */
2497 #define PNG_PASS_ROW_OFFSET(pass) ((pass)>2?(8>>(((pass)-1)>>1)):8)
2498 #define PNG_PASS_COL_OFFSET(pass) (1<<((7-(pass))>>1))
2499
2500 /* Two macros to help evaluate the number of rows or columns in each
2501 * pass. This is expressed as a shift - effectively log2 of the number or
2502 * rows or columns in each 8x8 tile of the original image.
2503 */
2504 #define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3)
2505 #define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3)
2506
2507 /* Hence two macros to determine the number of rows or columns in a given
2508 * pass of an image given its height or width. In fact these macros may
2509 * return non-zero even though the sub-image is empty, because the other
2510 * dimension may be empty for a small image.
2511 */
2512 #define PNG_PASS_ROWS(height, pass) (((height)+(((1<<PNG_PASS_ROW_SHIFT(pass))\
2513 -1)-PNG_PASS_START_ROW(pass)))>>PNG_PASS_ROW_SHIFT(pass))
2514 #define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\
2515 -1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass))
2516
2517 /* For the reader row callbacks (both progressive and sequential) it is
2518 * necessary to find the row in the output image given a row in an interlaced
2519 * image, so two more macros:
2520 */
2521 #define PNG_ROW_FROM_PASS_ROW(y_in, pass) \
2522 (((y_in)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass))
2523 #define PNG_COL_FROM_PASS_COL(x_in, pass) \
2524 (((x_in)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass))
2525
2526 /* Two macros which return a boolean (0 or 1) saying whether the given row
2527 * or column is in a particular pass. These use a common utility macro that
2528 * returns a mask for a given pass - the offset 'off' selects the row or
2529 * column version. The mask has the appropriate bit set for each column in
2530 * the tile.
2531 */
2532 #define PNG_PASS_MASK(pass,off) ( \
2533 ((0x110145AF>>(((7-(off))-(pass))<<2)) & 0xF) | \
2534 ((0x01145AF0>>(((7-(off))-(pass))<<2)) & 0xF0))
2535
2536 #define PNG_ROW_IN_INTERLACE_PASS(y, pass) \
2537 ((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1)
2538 #define PNG_COL_IN_INTERLACE_PASS(x, pass) \
2539 ((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1)
2540
2541 #ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
2542 /* With these routines we avoid an integer divide, which will be slower on
2543 * most machines. However, it does take more operations than the corresponding
2544 * divide method, so it may be slower on a few RISC systems. There are two
2545 * shifts (by 8 or 16 bits) and an addition, versus a single integer divide.
2546 *
2547 * Note that the rounding factors are NOT supposed to be the same! 128 and
2548 * 32768 are correct for the NODIV code; 127 and 32767 are correct for the
2549 * standard method.
2550 *
2551 * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
2552 */
2553
2554 /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */
2555
2556 # define png_composite(composite, fg, alpha, bg) \
2557 { \
2558 png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \
2559 * (png_uint_16)(alpha) \
2560 + (png_uint_16)(bg)*(png_uint_16)(255 \
2561 - (png_uint_16)(alpha)) + 128); \
2562 (composite) = (png_byte)(((temp + (temp >> 8)) >> 8) & 0xff); \
2563 }
2564
2565 # define png_composite_16(composite, fg, alpha, bg) \
2566 { \
2567 png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) \
2568 * (png_uint_32)(alpha) \
2569 + (png_uint_32)(bg)*(65535 \
2570 - (png_uint_32)(alpha)) + 32768); \
2571 (composite) = (png_uint_16)(0xffff & ((temp + (temp >> 16)) >> 16)); \
2572 }
2573
2574 #else /* Standard method using integer division */
2575
2576 # define png_composite(composite, fg, alpha, bg) \
2577 (composite) = \
2578 (png_byte)(0xff & (((png_uint_16)(fg) * (png_uint_16)(alpha) + \
2579 (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \
2580 127) / 255))
2581
2582 # define png_composite_16(composite, fg, alpha, bg) \
2583 (composite) = \
2584 (png_uint_16)(0xffff & (((png_uint_32)(fg) * (png_uint_32)(alpha) + \
2585 (png_uint_32)(bg)*(png_uint_32)(65535 - (png_uint_32)(alpha)) + \
2586 32767) / 65535))
2587 #endif /* READ_COMPOSITE_NODIV */
2588
2589 #ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED
2590 PNG_EXPORT(201, png_uint_32, png_get_uint_32, (png_const_bytep buf));
2591 PNG_EXPORT(202, png_uint_16, png_get_uint_16, (png_const_bytep buf));
2592 PNG_EXPORT(203, png_int_32, png_get_int_32, (png_const_bytep buf));
2593 #endif
2594
2595 PNG_EXPORT(204, png_uint_32, png_get_uint_31, (png_const_structrp png_ptr,
2596 png_const_bytep buf));
2597 /* No png_get_int_16 -- may be added if there's a real need for it. */
2598
2599 /* Place a 32-bit number into a buffer in PNG byte order (big-endian). */
2600 #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
2601 PNG_EXPORT(205, void, png_save_uint_32, (png_bytep buf, png_uint_32 i));
2602 #endif
2603 #ifdef PNG_SAVE_INT_32_SUPPORTED
2604 PNG_EXPORT(206, void, png_save_int_32, (png_bytep buf, png_int_32 i));
2605 #endif
2606
2607 /* Place a 16-bit number into a buffer in PNG byte order.
2608 * The parameter is declared unsigned int, not png_uint_16,
2609 * just to avoid potential problems on pre-ANSI C compilers.
2610 */
2611 #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
2612 PNG_EXPORT(207, void, png_save_uint_16, (png_bytep buf, unsigned int i));
2613 /* No png_save_int_16 -- may be added if there's a real need for it. */
2614 #endif
2615
2616 #ifdef PNG_USE_READ_MACROS
2617 /* Inline macros to do direct reads of bytes from the input buffer.
2618 * The png_get_int_32() routine assumes we are using two's complement
2619 * format for negative values, which is almost certainly true.
2620 */
2621 # define PNG_get_uint_32(buf) \
2622 (((png_uint_32)(*(buf)) << 24) + \
2623 ((png_uint_32)(*((buf) + 1)) << 16) + \
2624 ((png_uint_32)(*((buf) + 2)) << 8) + \
2625 ((png_uint_32)(*((buf) + 3))))
2626
2627 /* From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the
2628 * function) incorrectly returned a value of type png_uint_32.
2629 */
2630 # define PNG_get_uint_16(buf) \
2631 ((png_uint_16) \
2632 (((unsigned int)(*(buf)) << 8) + \
2633 ((unsigned int)(*((buf) + 1)))))
2634
2635 # define PNG_get_int_32(buf) \
2636 ((png_int_32)((*(buf) & 0x80) \
2637 ? -((png_int_32)(((png_get_uint_32(buf)^0xffffffffU)+1U)&0x7fffffffU)) \
2638 : (png_int_32)png_get_uint_32(buf)))
2639
2640 /* If PNG_PREFIX is defined the same thing as below happens in pnglibconf.h,
2641 * but defining a macro name prefixed with PNG_PREFIX.
2642 */
2643 # ifndef PNG_PREFIX
2644 # define png_get_uint_32(buf) PNG_get_uint_32(buf)
2645 # define png_get_uint_16(buf) PNG_get_uint_16(buf)
2646 # define png_get_int_32(buf) PNG_get_int_32(buf)
2647 # endif
2648 #else
2649 # ifdef PNG_PREFIX
2650 /* No macros; revert to the (redefined) function */
2651 # define PNG_get_uint_32 (png_get_uint_32)
2652 # define PNG_get_uint_16 (png_get_uint_16)
2653 # define PNG_get_int_32 (png_get_int_32)
2654 # endif
2655 #endif
2656
2657 #ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
2658 PNG_EXPORT(242, void, png_set_check_for_invalid_index,
2659 (png_structrp png_ptr, int allowed));
2660 # ifdef PNG_GET_PALETTE_MAX_SUPPORTED
2661 PNG_EXPORT(243, int, png_get_palette_max, (png_const_structp png_ptr,
2662 png_const_infop info_ptr));
2663 # endif
2664 #endif /* CHECK_FOR_INVALID_INDEX */
2665
2666 /*******************************************************************************
2667 * Section 5: SIMPLIFIED API
2668 *******************************************************************************
2669 *
2670 * Please read the documentation in libpng-manual.txt (TODO: write said
2671 * documentation) if you don't understand what follows.
2672 *
2673 * The simplified API hides the details of both libpng and the PNG file format
2674 * itself. It allows PNG files to be read into a very limited number of
2675 * in-memory bitmap formats or to be written from the same formats. If these
2676 * formats do not accomodate your needs then you can, and should, use the more
2677 * sophisticated APIs above - these support a wide variety of in-memory formats
2678 * and a wide variety of sophisticated transformations to those formats as well
2679 * as a wide variety of APIs to manipulate ancillary information.
2680 *
2681 * To read a PNG file using the simplified API:
2682 *
2683 * 1) Declare a 'png_image' structure (see below) on the stack, set the
2684 * version field to PNG_IMAGE_VERSION and the 'opaque' pointer to NULL
2685 * (this is REQUIRED, your program may crash if you don't do it.)
2686 * 2) Call the appropriate png_image_begin_read... function.
2687 * 3) Set the png_image 'format' member to the required sample format.
2688 * 4) Allocate a buffer for the image and, if required, the color-map.
2689 * 5) Call png_image_finish_read to read the image and, if required, the
2690 * color-map into your buffers.
2691 *
2692 * There are no restrictions on the format of the PNG input itself; all valid
2693 * color types, bit depths, and interlace methods are acceptable, and the
2694 * input image is transformed as necessary to the requested in-memory format
2695 * during the png_image_finish_read() step. The only caveat is that if you
2696 * request a color-mapped image from a PNG that is full-color or makes
2697 * complex use of an alpha channel the transformation is extremely lossy and the
2698 * result may look terrible.
2699 *
2700 * To write a PNG file using the simplified API:
2701 *
2702 * 1) Declare a 'png_image' structure on the stack and memset() it to all zero.
2703 * 2) Initialize the members of the structure that describe the image, setting
2704 * the 'format' member to the format of the image samples.
2705 * 3) Call the appropriate png_image_write... function with a pointer to the
2706 * image and, if necessary, the color-map to write the PNG data.
2707 *
2708 * png_image is a structure that describes the in-memory format of an image
2709 * when it is being read or defines the in-memory format of an image that you
2710 * need to write:
2711 */
2712 #if defined(PNG_SIMPLIFIED_READ_SUPPORTED) || \
2713 defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
2714
2715 #define PNG_IMAGE_VERSION 1
2716
2717 typedef struct png_control *png_controlp;
2718 typedef struct
2719 {
2720 png_controlp opaque; /* Initialize to NULL, free with png_image_free */
2721 png_uint_32 version; /* Set to PNG_IMAGE_VERSION */
2722 png_uint_32 width; /* Image width in pixels (columns) */
2723 png_uint_32 height; /* Image height in pixels (rows) */
2724 png_uint_32 format; /* Image format as defined below */
2725 png_uint_32 flags; /* A bit mask containing informational flags */
2726 png_uint_32 colormap_entries;
2727 /* Number of entries in the color-map */
2728
2729 /* In the event of an error or warning the following field will be set to a
2730 * non-zero value and the 'message' field will contain a '\0' terminated
2731 * string with the libpng error or warning message. If both warnings and
2732 * an error were encountered, only the error is recorded. If there
2733 * are multiple warnings, only the first one is recorded.
2734 *
2735 * The upper 30 bits of this value are reserved, the low two bits contain
2736 * a value as follows:
2737 */
2738 # define PNG_IMAGE_WARNING 1
2739 # define PNG_IMAGE_ERROR 2
2740 /*
2741 * The result is a two-bit code such that a value more than 1 indicates
2742 * a failure in the API just called:
2743 *
2744 * 0 - no warning or error
2745 * 1 - warning
2746 * 2 - error
2747 * 3 - error preceded by warning
2748 */
2749 # define PNG_IMAGE_FAILED(png_cntrl) ((((png_cntrl).warning_or_error)&0x03)>1)
2750
2751 png_uint_32 warning_or_error;
2752
2753 char message[64];
2754 } png_image, *png_imagep;
2755
2756 /* The samples of the image have one to four channels whose components have
2757 * original values in the range 0 to 1.0:
2758 *
2759 * 1: A single gray or luminance channel (G).
2760 * 2: A gray/luminance channel and an alpha channel (GA).
2761 * 3: Three red, green, blue color channels (RGB).
2762 * 4: Three color channels and an alpha channel (RGBA).
2763 *
2764 * The components are encoded in one of two ways:
2765 *
2766 * a) As a small integer, value 0..255, contained in a single byte. For the
2767 * alpha channel the original value is simply value/255. For the color or
2768 * luminance channels the value is encoded according to the sRGB specification
2769 * and matches the 8-bit format expected by typical display devices.
2770 *
2771 * The color/gray channels are not scaled (pre-multiplied) by the alpha
2772 * channel and are suitable for passing to color management software.
2773 *
2774 * b) As a value in the range 0..65535, contained in a 2-byte integer. All
2775 * channels can be converted to the original value by dividing by 65535; all
2776 * channels are linear. Color channels use the RGB encoding (RGB end-points) of
2777 * the sRGB specification. This encoding is identified by the
2778 * PNG_FORMAT_FLAG_LINEAR flag below.
2779 *
2780 * When the simplified API needs to convert between sRGB and linear colorspaces,
2781 * the actual sRGB transfer curve defined in the sRGB specification (see the
2782 * article at http://en.wikipedia.org/wiki/SRGB) is used, not the gamma=1/2.2
2783 * approximation used elsewhere in libpng.
2784 *
2785 * When an alpha channel is present it is expected to denote pixel coverage
2786 * of the color or luminance channels and is returned as an associated alpha
2787 * channel: the color/gray channels are scaled (pre-multiplied) by the alpha
2788 * value.
2789 *
2790 * The samples are either contained directly in the image data, between 1 and 8
2791 * bytes per pixel according to the encoding, or are held in a color-map indexed
2792 * by bytes in the image data. In the case of a color-map the color-map entries
2793 * are individual samples, encoded as above, and the image data has one byte per
2794 * pixel to select the relevant sample from the color-map.
2795 */
2796
2797 /* PNG_FORMAT_*
2798 *
2799 * #defines to be used in png_image::format. Each #define identifies a
2800 * particular layout of sample data and, if present, alpha values. There are
2801 * separate defines for each of the two component encodings.
2802 *
2803 * A format is built up using single bit flag values. All combinations are
2804 * valid. Formats can be built up from the flag values or you can use one of
2805 * the predefined values below. When testing formats always use the FORMAT_FLAG
2806 * macros to test for individual features - future versions of the library may
2807 * add new flags.
2808 *
2809 * When reading or writing color-mapped images the format should be set to the
2810 * format of the entries in the color-map then png_image_{read,write}_colormap
2811 * called to read or write the color-map and set the format correctly for the
2812 * image data. Do not set the PNG_FORMAT_FLAG_COLORMAP bit directly!
2813 *
2814 * NOTE: libpng can be built with particular features disabled. If you see
2815 * compiler errors because the definition of one of the following flags has been
2816 * compiled out it is because libpng does not have the required support. It is
2817 * possible, however, for the libpng configuration to enable the format on just
2818 * read or just write; in that case you may see an error at run time. You can
2819 * guard against this by checking for the definition of the appropriate
2820 * "_SUPPORTED" macro, one of:
2821 *
2822 * PNG_SIMPLIFIED_{READ,WRITE}_{BGR,AFIRST}_SUPPORTED
2823 */
2824 #define PNG_FORMAT_FLAG_ALPHA 0x01U /* format with an alpha channel */
2825 #define PNG_FORMAT_FLAG_COLOR 0x02U /* color format: otherwise grayscale */
2826 #define PNG_FORMAT_FLAG_LINEAR 0x04U /* 2-byte channels else 1-byte */
2827 #define PNG_FORMAT_FLAG_COLORMAP 0x08U /* image data is color-mapped */
2828
2829 #ifdef PNG_FORMAT_BGR_SUPPORTED
2830 # define PNG_FORMAT_FLAG_BGR 0x10U /* BGR colors, else order is RGB */
2831 #endif
2832
2833 #ifdef PNG_FORMAT_AFIRST_SUPPORTED
2834 # define PNG_FORMAT_FLAG_AFIRST 0x20U /* alpha channel comes first */
2835 #endif
2836
2837 /* Commonly used formats have predefined macros.
2838 *
2839 * First the single byte (sRGB) formats:
2840 */
2841 #define PNG_FORMAT_GRAY 0
2842 #define PNG_FORMAT_GA PNG_FORMAT_FLAG_ALPHA
2843 #define PNG_FORMAT_AG (PNG_FORMAT_GA|PNG_FORMAT_FLAG_AFIRST)
2844 #define PNG_FORMAT_RGB PNG_FORMAT_FLAG_COLOR
2845 #define PNG_FORMAT_BGR (PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_BGR)
2846 #define PNG_FORMAT_RGBA (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_ALPHA)
2847 #define PNG_FORMAT_ARGB (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_AFIRST)
2848 #define PNG_FORMAT_BGRA (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_ALPHA)
2849 #define PNG_FORMAT_ABGR (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_AFIRST)
2850
2851 /* Then the linear 2-byte formats. When naming these "Y" is used to
2852 * indicate a luminance (gray) channel.
2853 */
2854 #define PNG_FORMAT_LINEAR_Y PNG_FORMAT_FLAG_LINEAR
2855 #define PNG_FORMAT_LINEAR_Y_ALPHA (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_ALPHA)
2856 #define PNG_FORMAT_LINEAR_RGB (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR)
2857 #define PNG_FORMAT_LINEAR_RGB_ALPHA \
2858 (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA)
2859
2860 /* With color-mapped formats the image data is one byte for each pixel, the byte
2861 * is an index into the color-map which is formatted as above. To obtain a
2862 * color-mapped format it is sufficient just to add the PNG_FOMAT_FLAG_COLORMAP
2863 * to one of the above definitions, or you can use one of the definitions below.
2864 */
2865 #define PNG_FORMAT_RGB_COLORMAP (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_COLORMAP)
2866 #define PNG_FORMAT_BGR_COLORMAP (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_COLORMAP)
2867 #define PNG_FORMAT_RGBA_COLORMAP (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_COLORMAP)
2868 #define PNG_FORMAT_ARGB_COLORMAP (PNG_FORMAT_ARGB|PNG_FORMAT_FLAG_COLORMAP)
2869 #define PNG_FORMAT_BGRA_COLORMAP (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_COLORMAP)
2870 #define PNG_FORMAT_ABGR_COLORMAP (PNG_FORMAT_ABGR|PNG_FORMAT_FLAG_COLORMAP)
2871
2872 /* PNG_IMAGE macros
2873 *
2874 * These are convenience macros to derive information from a png_image
2875 * structure. The PNG_IMAGE_SAMPLE_ macros return values appropriate to the
2876 * actual image sample values - either the entries in the color-map or the
2877 * pixels in the image. The PNG_IMAGE_PIXEL_ macros return corresponding values
2878 * for the pixels and will always return 1 for color-mapped formats. The
2879 * remaining macros return information about the rows in the image and the
2880 * complete image.
2881 *
2882 * NOTE: All the macros that take a png_image::format parameter are compile time
2883 * constants if the format parameter is, itself, a constant. Therefore these
2884 * macros can be used in array declarations and case labels where required.
2885 * Similarly the macros are also pre-processor constants (sizeof is not used) so
2886 * they can be used in #if tests.
2887 *
2888 * First the information about the samples.
2889 */
2890 #define PNG_IMAGE_SAMPLE_CHANNELS(fmt)\
2891 (((fmt)&(PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA))+1)
2892 /* Return the total number of channels in a given format: 1..4 */
2893
2894 #define PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)\
2895 ((((fmt) & PNG_FORMAT_FLAG_LINEAR) >> 2)+1)
2896 /* Return the size in bytes of a single component of a pixel or color-map
2897 * entry (as appropriate) in the image: 1 or 2.
2898 */
2899
2900 #define PNG_IMAGE_SAMPLE_SIZE(fmt)\
2901 (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt))
2902 /* This is the size of the sample data for one sample. If the image is
2903 * color-mapped it is the size of one color-map entry (and image pixels are
2904 * one byte in size), otherwise it is the size of one image pixel.
2905 */
2906
2907 #define PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(fmt)\
2908 (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * 256)
2909 /* The maximum size of the color-map required by the format expressed in a
2910 * count of components. This can be used to compile-time allocate a
2911 * color-map:
2912 *
2913 * png_uint_16 colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(linear_fmt)];
2914 *
2915 * png_byte colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(sRGB_fmt)];
2916 *
2917 * Alternatively use the PNG_IMAGE_COLORMAP_SIZE macro below to use the
2918 * information from one of the png_image_begin_read_ APIs and dynamically
2919 * allocate the required memory.
2920 */
2921
2922 /* Corresponding information about the pixels */
2923 #define PNG_IMAGE_PIXEL_(test,fmt)\
2924 (((fmt)&PNG_FORMAT_FLAG_COLORMAP)?1:test(fmt))
2925
2926 #define PNG_IMAGE_PIXEL_CHANNELS(fmt)\
2927 PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_CHANNELS,fmt)
2928 /* The number of separate channels (components) in a pixel; 1 for a
2929 * color-mapped image.
2930 */
2931
2932 #define PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt)\
2933 PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_COMPONENT_SIZE,fmt)
2934 /* The size, in bytes, of each component in a pixel; 1 for a color-mapped
2935 * image.
2936 */
2937
2938 #define PNG_IMAGE_PIXEL_SIZE(fmt) PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_SIZE,fmt)
2939 /* The size, in bytes, of a complete pixel; 1 for a color-mapped image. */
2940
2941 /* Information about the whole row, or whole image */
2942 #define PNG_IMAGE_ROW_STRIDE(image)\
2943 (PNG_IMAGE_PIXEL_CHANNELS((image).format) * (image).width)
2944 /* Return the total number of components in a single row of the image; this
2945 * is the minimum 'row stride', the minimum count of components between each
2946 * row. For a color-mapped image this is the minimum number of bytes in a
2947 * row.
2948 *
2949 * WARNING: this macro overflows for some images with more than one component
2950 * and very large image widths. libpng will refuse to process an image where
2951 * this macro would overflow.
2952 */
2953
2954 #define PNG_IMAGE_BUFFER_SIZE(image, row_stride)\
2955 (PNG_IMAGE_PIXEL_COMPONENT_SIZE((image).format)*(image).height*(row_stride))
2956 /* Return the size, in bytes, of an image buffer given a png_image and a row
2957 * stride - the number of components to leave space for in each row.
2958 *
2959 * WARNING: this macro overflows a 32-bit integer for some large PNG images,
2960 * libpng will refuse to process an image where such an overflow would occur.
2961 */
2962
2963 #define PNG_IMAGE_SIZE(image)\
2964 PNG_IMAGE_BUFFER_SIZE(image, PNG_IMAGE_ROW_STRIDE(image))
2965 /* Return the size, in bytes, of the image in memory given just a png_image;
2966 * the row stride is the minimum stride required for the image.
2967 */
2968
2969 #define PNG_IMAGE_COLORMAP_SIZE(image)\
2970 (PNG_IMAGE_SAMPLE_SIZE((image).format) * (image).colormap_entries)
2971 /* Return the size, in bytes, of the color-map of this image. If the image
2972 * format is not a color-map format this will return a size sufficient for
2973 * 256 entries in the given format; check PNG_FORMAT_FLAG_COLORMAP if
2974 * you don't want to allocate a color-map in this case.
2975 */
2976
2977 /* PNG_IMAGE_FLAG_*
2978 *
2979 * Flags containing additional information about the image are held in the
2980 * 'flags' field of png_image.
2981 */
2982 #define PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB 0x01
2983 /* This indicates the the RGB values of the in-memory bitmap do not
2984 * correspond to the red, green and blue end-points defined by sRGB.
2985 */
2986
2987 #define PNG_IMAGE_FLAG_FAST 0x02
2988 /* On write emphasise speed over compression; the resultant PNG file will be
2989 * larger but will be produced significantly faster, particular for large
2990 * images. Do not use this option for images which will be distributed, only
2991 * used it when producing intermediate files that will be read back in
2992 * repeatedly. For a typical 24-bit image the option will double the read
2993 * speed at the cost of increasing the image size by 25%, however for many
2994 * more compressible images the PNG file can be 10 times larger with only a
2995 * slight speed gain.
2996 */
2997
2998 #define PNG_IMAGE_FLAG_16BIT_sRGB 0x04
2999 /* On read if the image is a 16-bit per component image and there is no gAMA
3000 * or sRGB chunk assume that the components are sRGB encoded. Notice that
3001 * images output by the simplified API always have gamma information; setting
3002 * this flag only affects the interpretation of 16-bit images from an
3003 * external source. It is recommended that the application expose this flag
3004 * to the user; the user can normally easily recognize the difference between
3005 * linear and sRGB encoding. This flag has no effect on write - the data
3006 * passed to the write APIs must have the correct encoding (as defined
3007 * above.)
3008 *
3009 * If the flag is not set (the default) input 16-bit per component data is
3010 * assumed to be linear.
3011 *
3012 * NOTE: the flag can only be set after the png_image_begin_read_ call,
3013 * because that call initializes the 'flags' field.
3014 */
3015
3016 #ifdef PNG_SIMPLIFIED_READ_SUPPORTED
3017 /* READ APIs
3018 * ---------
3019 *
3020 * The png_image passed to the read APIs must have been initialized by setting
3021 * the png_controlp field 'opaque' to NULL (or, safer, memset the whole thing.)
3022 */
3023 #ifdef PNG_STDIO_SUPPORTED
3024 PNG_EXPORT(234, int, png_image_begin_read_from_file, (png_imagep image,
3025 const char *file_name));
3026 /* The named file is opened for read and the image header is filled in
3027 * from the PNG header in the file.
3028 */
3029
3030 PNG_EXPORT(235, int, png_image_begin_read_from_stdio, (png_imagep image,
3031 FILE* file));
3032 /* The PNG header is read from the stdio FILE object. */
3033 #endif /* STDIO */
3034
3035 PNG_EXPORT(236, int, png_image_begin_read_from_memory, (png_imagep image,
3036 png_const_voidp memory, png_size_t size));
3037 /* The PNG header is read from the given memory buffer. */
3038
3039 PNG_EXPORT(237, int, png_image_finish_read, (png_imagep image,
3040 png_const_colorp background, void *buffer, png_int_32 row_stride,
3041 void *colormap));
3042 /* Finish reading the image into the supplied buffer and clean up the
3043 * png_image structure.
3044 *
3045 * row_stride is the step, in byte or 2-byte units as appropriate,
3046 * between adjacent rows. A positive stride indicates that the top-most row
3047 * is first in the buffer - the normal top-down arrangement. A negative
3048 * stride indicates that the bottom-most row is first in the buffer.
3049 *
3050 * background need only be supplied if an alpha channel must be removed from
3051 * a png_byte format and the removal is to be done by compositing on a solid
3052 * color; otherwise it may be NULL and any composition will be done directly
3053 * onto the buffer. The value is an sRGB color to use for the background,
3054 * for grayscale output the green channel is used.
3055 *
3056 * background must be supplied when an alpha channel must be removed from a
3057 * single byte color-mapped output format, in other words if:
3058 *
3059 * 1) The original format from png_image_begin_read_from_* had
3060 * PNG_FORMAT_FLAG_ALPHA set.
3061 * 2) The format set by the application does not.
3062 * 3) The format set by the application has PNG_FORMAT_FLAG_COLORMAP set and
3063 * PNG_FORMAT_FLAG_LINEAR *not* set.
3064 *
3065 * For linear output removing the alpha channel is always done by compositing
3066 * on black and background is ignored.
3067 *
3068 * colormap must be supplied when PNG_FORMAT_FLAG_COLORMAP is set. It must
3069 * be at least the size (in bytes) returned by PNG_IMAGE_COLORMAP_SIZE.
3070 * image->colormap_entries will be updated to the actual number of entries
3071 * written to the colormap; this may be less than the original value.
3072 */
3073
3074 PNG_EXPORT(238, void, png_image_free, (png_imagep image));
3075 /* Free any data allocated by libpng in image->opaque, setting the pointer to
3076 * NULL. May be called at any time after the structure is initialized.
3077 */
3078 #endif /* SIMPLIFIED_READ */
3079
3080 #ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED
3081 /* WRITE APIS
3082 * ----------
3083 * For write you must initialize a png_image structure to describe the image to
3084 * be written. To do this use memset to set the whole structure to 0 then
3085 * initialize fields describing your image.
3086 *
3087 * version: must be set to PNG_IMAGE_VERSION
3088 * opaque: must be initialized to NULL
3089 * width: image width in pixels
3090 * height: image height in rows
3091 * format: the format of the data (image and color-map) you wish to write
3092 * flags: set to 0 unless one of the defined flags applies; set
3093 * PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB for color format images where the RGB
3094 * values do not correspond to the colors in sRGB.
3095 * colormap_entries: set to the number of entries in the color-map (0 to 256)
3096 */
3097 #ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED
3098 PNG_EXPORT(239, int, png_image_write_to_file, (png_imagep image,
3099 const char *file, int convert_to_8bit, const void *buffer,
3100 png_int_32 row_stride, const void *colormap));
3101 /* Write the image to the named file. */
3102
3103 PNG_EXPORT(240, int, png_image_write_to_stdio, (png_imagep image, FILE *file,
3104 int convert_to_8_bit, const void *buffer, png_int_32 row_stride,
3105 const void *colormap));
3106 /* Write the image to the given (FILE*). */
3107 #endif /* SIMPLIFIED_WRITE_STDIO */
3108
3109 /* With all write APIs if image is in one of the linear formats with 16-bit
3110 * data then setting convert_to_8_bit will cause the output to be an 8-bit PNG
3111 * gamma encoded according to the sRGB specification, otherwise a 16-bit linear
3112 * encoded PNG file is written.
3113 *
3114 * With color-mapped data formats the colormap parameter point to a color-map
3115 * with at least image->colormap_entries encoded in the specified format. If
3116 * the format is linear the written PNG color-map will be converted to sRGB
3117 * regardless of the convert_to_8_bit flag.
3118 *
3119 * With all APIs row_stride is handled as in the read APIs - it is the spacing
3120 * from one row to the next in component sized units (1 or 2 bytes) and if
3121 * negative indicates a bottom-up row layout in the buffer. If row_stride is
3122 * zero, libpng will calculate it for you from the image width and number of
3123 * channels.
3124 *
3125 * Note that the write API does not support interlacing, sub-8-bit pixels or
3126 * most ancillary chunks. If you need to write text chunks (e.g. for copyright
3127 * notices) you need to use one of the other APIs.
3128 */
3129
3130 PNG_EXPORT(245, int, png_image_write_to_memory, (png_imagep image, void *memory,
3131 png_alloc_size_t * PNG_RESTRICT memory_bytes, int convert_to_8_bit,
3132 const void *buffer, png_int_32 row_stride, const void *colormap));
3133 /* Write the image to the given memory buffer. The function both writes the
3134 * whole PNG data stream to *memory and updates *memory_bytes with the count
3135 * of bytes written.
3136 *
3137 * 'memory' may be NULL. In this case *memory_bytes is not read however on
3138 * success the number of bytes which would have been written will still be
3139 * stored in *memory_bytes. On failure *memory_bytes will contain 0.
3140 *
3141 * If 'memory' is not NULL it must point to memory[*memory_bytes] of
3142 * writeable memory.
3143 *
3144 * If the function returns success memory[*memory_bytes] (if 'memory' is not
3145 * NULL) contains the written PNG data. *memory_bytes will always be less
3146 * than or equal to the original value.
3147 *
3148 * If the function returns false and *memory_bytes was not changed an error
3149 * occured during write. If *memory_bytes was changed, or is not 0 if
3150 * 'memory' was NULL, the write would have succeeded but for the memory
3151 * buffer being too small. *memory_bytes contains the required number of
3152 * bytes and will be bigger that the original value.
3153 */
3154
3155 #define png_image_write_get_memory_size(image, size, convert_to_8_bit, buffer,\
3156 row_stride, colormap)\
3157 png_image_write_to_memory(&(image), 0, &(size), convert_to_8_bit, buffer,\
3158 row_stride, colormap)
3159 /* Return the amount of memory in 'size' required to compress this image.
3160 * The png_image structure 'image' must be filled in as in the above
3161 * function and must not be changed before the actual write call, the buffer
3162 * and all other parameters must also be identical to that in the final
3163 * write call. The 'size' variable need not be initialized.
3164 *
3165 * NOTE: the macro returns true/false, if false is returned 'size' will be
3166 * set to zero and the write failed and probably will fail if tried again.
3167 */
3168
3169 /* You can pre-allocate the buffer by making sure it is of sufficient size
3170 * regardless of the amount of compression achieved. The buffer size will
3171 * always be bigger than the original image and it will never be filled. The
3172 * following macros are provided to assist in allocating the buffer.
3173 */
3174 #define PNG_IMAGE_DATA_SIZE(image) (PNG_IMAGE_SIZE(image)+(image).height)
3175 /* The number of uncompressed bytes in the PNG byte encoding of the image;
3176 * uncompressing the PNG IDAT data will give this number of bytes.
3177 *
3178 * NOTE: while PNG_IMAGE_SIZE cannot overflow for an image in memory this
3179 * macro can because of the extra bytes used in the PNG byte encoding. You
3180 * need to avoid this macro if your image size approaches 2^30 in width or
3181 * height. The same goes for the remainder of these macros; they all produce
3182 * bigger numbers than the actual in-memory image size.
3183 */
3184 #ifndef PNG_ZLIB_MAX_SIZE
3185 # define PNG_ZLIB_MAX_SIZE(b) ((b)+(((b)+7U)>>3)+(((b)+63U)>>6)+11U)
3186 /* An upper bound on the number of compressed bytes given 'b' uncompressed
3187 * bytes. This is based on deflateBounds() in zlib; different
3188 * implementations of zlib compression may conceivably produce more data so
3189 * if your zlib implementation is not zlib itself redefine this macro
3190 * appropriately.
3191 */
3192 #endif
3193
3194 #define PNG_IMAGE_COMPRESSED_SIZE_MAX(image)\
3195 PNG_ZLIB_MAX_SIZE((png_alloc_size_t)PNG_IMAGE_DATA_SIZE(image))
3196 /* An upper bound on the size of the data in the PNG IDAT chunks. */
3197
3198 #define PNG_IMAGE_PNG_SIZE_MAX_(image, image_size)\
3199 ((8U/*sig*/+25U/*IHDR*/+16U/*gAMA*/+44U/*cHRM*/+12U/*IEND*/+\
3200 (((image).format&PNG_FORMAT_FLAG_COLORMAP)?/*colormap: PLTE, tRNS*/\
3201 12U+3U*(image).colormap_entries/*PLTE data*/+\
3202 (((image).format&PNG_FORMAT_FLAG_ALPHA)?\
3203 12U/*tRNS*/+(image).colormap_entries:0U):0U)+\
3204 12U)+(12U*((image_size)/PNG_ZBUF_SIZE))/*IDAT*/+(image_size))
3205 /* A helper for the following macro; if your compiler cannot handle the
3206 * following macro use this one with the result of
3207 * PNG_IMAGE_COMPRESSED_SIZE_MAX(image) as the second argument (most
3208 * compilers should handle this just fine.)
3209 */
3210
3211 #define PNG_IMAGE_PNG_SIZE_MAX(image)\
3212 PNG_IMAGE_PNG_SIZE_MAX_(image, PNG_IMAGE_COMPRESSED_SIZE_MAX(image))
3213 /* An upper bound on the total length of the PNG data stream for 'image'.
3214 * The result is of type png_alloc_size_t, on 32-bit systems this may
3215 * overflow even though PNG_IMAGE_DATA_SIZE does not overflow; the write will
3216 * run out of buffer space but return a corrected size which should work.
3217 */
3218 #endif /* SIMPLIFIED_WRITE */
3219 /*******************************************************************************
3220 * END OF SIMPLIFIED API
3221 ******************************************************************************/
3222 #endif /* SIMPLIFIED_{READ|WRITE} */
3223
3224 /*******************************************************************************
3225 * Section 6: IMPLEMENTATION OPTIONS
3226 *******************************************************************************
3227 *
3228 * Support for arbitrary implementation-specific optimizations. The API allows
3229 * particular options to be turned on or off. 'Option' is the number of the
3230 * option and 'onoff' is 0 (off) or non-0 (on). The value returned is given
3231 * by the PNG_OPTION_ defines below.
3232 *
3233 * HARDWARE: normally hardware capabilites, such as the Intel SSE instructions,
3234 * are detected at run time, however sometimes it may be impossible
3235 * to do this in user mode, in which case it is necessary to discover
3236 * the capabilities in an OS specific way. Such capabilities are
3237 * listed here when libpng has support for them and must be turned
3238 * ON by the application if present.
3239 *
3240 * SOFTWARE: sometimes software optimizations actually result in performance
3241 * decrease on some architectures or systems, or with some sets of
3242 * PNG images. 'Software' options allow such optimizations to be
3243 * selected at run time.
3244 */
3245 #ifdef PNG_SET_OPTION_SUPPORTED
3246 #ifdef PNG_ARM_NEON_API_SUPPORTED
3247 # define PNG_ARM_NEON 0 /* HARDWARE: ARM Neon SIMD instructions supported */
3248 #endif
3249 #define PNG_MAXIMUM_INFLATE_WINDOW 2 /* SOFTWARE: force maximum window */
3250 #define PNG_SKIP_sRGB_CHECK_PROFILE 4 /* SOFTWARE: Check ICC profile for sRGB */
3251 #ifdef PNG_MIPS_MSA_API_SUPPORTED
3252 # define PNG_MIPS_MSA 6 /* HARDWARE: MIPS Msa SIMD instructions supported */
3253 #endif
3254 #define PNG_IGNORE_ADLER32 8
3255 #define PNG_OPTION_NEXT 10 /* Next option - numbers must be even */
3256
3257 /* Return values: NOTE: there are four values and 'off' is *not* zero */
3258 #define PNG_OPTION_UNSET 0 /* Unset - defaults to off */
3259 #define PNG_OPTION_INVALID 1 /* Option number out of range */
3260 #define PNG_OPTION_OFF 2
3261 #define PNG_OPTION_ON 3
3262
3263 PNG_EXPORT(244, int, png_set_option, (png_structrp png_ptr, int option,
3264 int onoff));
3265 #endif /* SET_OPTION */
3266
3267 /*******************************************************************************
3268 * END OF HARDWARE AND SOFTWARE OPTIONS
3269 ******************************************************************************/
3270
3271 /* Maintainer: Put new public prototypes here ^, in libpng.3, in project
3272 * defs, and in scripts/symbols.def.
3273 */
3274
3275 /* The last ordinal number (this is the *last* one already used; the next
3276 * one to use is one more than this.)
3277 */
3278 #ifdef PNG_EXPORT_LAST_ORDINAL
3279 PNG_EXPORT_LAST_ORDINAL(245);
3280 #endif
3281
3282 #ifdef __cplusplus
3283 }
3284 #endif
3285
3286 #endif /* PNG_VERSION_INFO_ONLY */
3287 /* Do not put anything past this line */
3288 #endif /* PNG_H */