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 1.6.23, June 9, 2016
33 *
34 * Copyright (c) 1998-2002,2004,2006-2016 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 1.6.23, June 9, 2016:
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 * Some files in the "contrib" directory and some configure-generated
57 * files that are distributed with libpng have other copyright owners and
58 * are released under other open source licenses.
59 *
60 * libpng versions 1.0.7, July 1, 2000 through 1.6.23, June 9, 2016 are
61 * Copyright (c) 2000-2002, 2004, 2006-2016 Glenn Randers-Pehrson, are
62 * derived from libpng-1.0.6, and are distributed according to the same
63 * disclaimer and license as libpng-1.0.6 with the following individuals
64 * added to the list of Contributing Authors:
65 *
66 * Simon-Pierre Cadieux
67 * Eric S. Raymond
68 * Mans Rullgard
69 * Cosmin Truta
70 * Gilles Vollant
71 * James Yu
72 *
73 * and with the following additions to the disclaimer:
74 *
75 * There is no warranty against interference with your enjoyment of the
76 * library or against infringement. There is no warranty that our
77 * efforts or the library will fulfill any of your particular purposes
78 * or needs. This library is provided with all faults, and the entire
79 * risk of satisfactory quality, performance, accuracy, and effort is with
80 * the user.
81 *
82 * Some files in the "contrib" directory have other copyright owners and
83 * are released under other open source licenses.
84 *
85 *
86 * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
87 * Copyright (c) 1998-2000 Glenn Randers-Pehrson, are derived from
88 * libpng-0.96, and are distributed according to the same disclaimer and
89 * license as libpng-0.96, with the following individuals added to the list
90 * of Contributing Authors:
91 *
92 * Tom Lane
93 * Glenn Randers-Pehrson
94 * Willem van Schaik
95 *
96 * Some files in the "scripts" directory have different copyright owners
97 * but are also released under this license.
98 *
99 * libpng versions 0.89, June 1996, through 0.96, May 1997, are
100 * Copyright (c) 1996-1997 Andreas Dilger, are derived from libpng-0.88,
101 * and are distributed according to the same disclaimer and license as
102 * libpng-0.88, with the following individuals added to the list of
103 * Contributing Authors:
104 *
105 * John Bowler
106 * Kevin Bracey
107 * Sam Bushell
108 * Magnus Holmgren
109 * Greg Roelofs
110 * Tom Tanner
111 *
112 * Some files in the "scripts" directory have other copyright owners
113 * but are released under this license.
114 *
115 * libpng versions 0.5, May 1995, through 0.88, January 1996, are
116 * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
117 *
118 * For the purposes of this copyright and license, "Contributing Authors"
119 * is defined as the following set of individuals:
120 *
121 * Andreas Dilger
122 * Dave Martindale
123 * Guy Eric Schalnat
124 * Paul Schmidt
125 * Tim Wegner
126 *
127 * The PNG Reference Library is supplied "AS IS". The Contributing Authors
128 * and Group 42, Inc. disclaim all warranties, expressed or implied,
129 * including, without limitation, the warranties of merchantability and of
130 * fitness for any purpose. The Contributing Authors and Group 42, Inc.
131 * assume no liability for direct, indirect, incidental, special, exemplary,
132 * or consequential damages, which may result from the use of the PNG
133 * Reference Library, even if advised of the possibility of such damage.
134 *
135 * Permission is hereby granted to use, copy, modify, and distribute this
136 * source code, or portions hereof, for any purpose, without fee, subject
137 * to the following restrictions:
138 *
139 * 1. The origin of this source code must not be misrepresented.
140 *
141 * 2. Altered versions must be plainly marked as such and must not
142 * be misrepresented as being the original source.
143 *
144 * 3. This Copyright notice may not be removed or altered from any
145 * source or altered source distribution.
146 *
147 * The Contributing Authors and Group 42, Inc. specifically permit, without
148 * fee, and encourage the use of this source code as a component to
149 * supporting the PNG file format in commercial products. If you use this
150 * source code in a product, acknowledgment is not required but would be
151 * appreciated.
152 *
153 * END OF COPYRIGHT NOTICE, DISCLAIMER, and LICENSE.
154 *
155 * TRADEMARK:
156 *
157 * The name "libpng" has not been registered by the Copyright owner
158 * as a trademark in any jurisdiction. However, because libpng has
159 * been distributed and maintained world-wide, continually since 1995,
160 * the Copyright owner claims "common-law trademark protection" in any
161 * jurisdiction where common-law trademark is recognized.
162 *
163 * OSI CERTIFICATION:
164 *
165 * Libpng is OSI Certified Open Source Software. OSI Certified Open Source is
166 * a certification mark of the Open Source Initiative. OSI has not addressed
167 * the additional disclaimers inserted at version 1.0.7.
168 *
169 * EXPORT CONTROL:
170 *
171 * The Copyright owner believes that the Export Control Classification
172 * Number (ECCN) for libpng is EAR99, which means not subject to export
173 * controls or International Traffic in Arms Regulations (ITAR) because
174 * it is open source, publicly available software, that does not contain
175 * any encryption software. See the EAR, paragraphs 734.3(b)(3) and
176 * 734.7(b).
177 */
178
179 /*
180 * A "png_get_copyright" function is available, for convenient use in "about"
181 * boxes and the like:
182 *
183 * printf("%s", png_get_copyright(NULL));
184 *
185 * Also, the PNG logo (in PNG format, of course) is supplied in the
186 * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
187 */
188
189 /*
190 * The contributing authors would like to thank all those who helped
191 * with testing, bug fixes, and patience. This wouldn't have been
192 * possible without all of you.
193 *
194 * Thanks to Frank J. T. Wojcik for helping with the documentation.
195 */
196
197 /* Note about libpng version numbers:
198 *
199 * Due to various miscommunications, unforeseen code incompatibilities
200 * and occasional factors outside the authors' control, version numbering
201 * on the library has not always been consistent and straightforward.
202 * The following table summarizes matters since version 0.89c, which was
203 * the first widely used release:
204 *
205 * source png.h png.h shared-lib
206 * version string int version
207 * ------- ------ ----- ----------
208 * 0.89c "1.0 beta 3" 0.89 89 1.0.89
209 * 0.90 "1.0 beta 4" 0.90 90 0.90 [should have been 2.0.90]
210 * 0.95 "1.0 beta 5" 0.95 95 0.95 [should have been 2.0.95]
211 * 0.96 "1.0 beta 6" 0.96 96 0.96 [should have been 2.0.96]
212 * 0.97b "1.00.97 beta 7" 1.00.97 97 1.0.1 [should have been 2.0.97]
213 * 0.97c 0.97 97 2.0.97
214 * 0.98 0.98 98 2.0.98
215 * 0.99 0.99 98 2.0.99
216 * 0.99a-m 0.99 99 2.0.99
217 * 1.00 1.00 100 2.1.0 [100 should be 10000]
218 * 1.0.0 (from here on, the 100 2.1.0 [100 should be 10000]
219 * 1.0.1 png.h string is 10001 2.1.0
220 * 1.0.1a-e identical to the 10002 from here on, the shared library
221 * 1.0.2 source version) 10002 is 2.V where V is the source code
222 * 1.0.2a-b 10003 version, except as noted.
223 * 1.0.3 10003
224 * 1.0.3a-d 10004
225 * 1.0.4 10004
226 * 1.0.4a-f 10005
227 * 1.0.5 (+ 2 patches) 10005
228 * 1.0.5a-d 10006
229 * 1.0.5e-r 10100 (not source compatible)
230 * 1.0.5s-v 10006 (not binary compatible)
231 * 1.0.6 (+ 3 patches) 10006 (still binary incompatible)
232 * 1.0.6d-f 10007 (still binary incompatible)
233 * 1.0.6g 10007
234 * 1.0.6h 10007 10.6h (testing xy.z so-numbering)
235 * 1.0.6i 10007 10.6i
236 * 1.0.6j 10007 2.1.0.6j (incompatible with 1.0.0)
237 * 1.0.7beta11-14 DLLNUM 10007 2.1.0.7beta11-14 (binary compatible)
238 * 1.0.7beta15-18 1 10007 2.1.0.7beta15-18 (binary compatible)
239 * 1.0.7rc1-2 1 10007 2.1.0.7rc1-2 (binary compatible)
240 * 1.0.7 1 10007 (still compatible)
241 * ...
242 * 1.0.19 10 10019 10.so.0.19[.0]
243 * ...
244 * 1.2.56 13 10256 12.so.0.56[.0]
245 * ...
246 * 1.5.27 15 10527 15.so.15.27[.0]
247 * ...
248 * 1.6.23 16 10623 16.so.16.23[.0]
249 *
250 * Henceforth the source version will match the shared-library major
251 * and minor numbers; the shared-library major version number will be
252 * used for changes in backward compatibility, as it is intended. The
253 * PNG_LIBPNG_VER macro, which is not used within libpng but is available
254 * for applications, is an unsigned integer of the form xyyzz corresponding
255 * to the source version x.y.z (leading zeros in y and z). Beta versions
256 * were given the previous public release number plus a letter, until
257 * version 1.0.6j; from then on they were given the upcoming public
258 * release number plus "betaNN" or "rcNN".
259 *
260 * Binary incompatibility exists only when applications make direct access
261 * to the info_ptr or png_ptr members through png.h, and the compiled
262 * application is loaded with a different version of the library.
263 *
264 * DLLNUM will change each time there are forward or backward changes
265 * in binary compatibility (e.g., when a new feature is added).
266 *
267 * See libpng.txt or libpng.3 for more information. The PNG specification
268 * is available as a W3C Recommendation and as an ISO Specification,
269 * <http://www.w3.org/TR/2003/REC-PNG-20031110/
270 */
271
272 /*
273 * Y2K compliance in libpng:
274 * =========================
275 *
276 * June 9, 2016
277 *
278 * Since the PNG Development group is an ad-hoc body, we can't make
279 * an official declaration.
280 *
281 * This is your unofficial assurance that libpng from version 0.71 and
282 * upward through 1.6.23 are Y2K compliant. It is my belief that
283 * earlier versions were also Y2K compliant.
284 *
285 * Libpng only has two year fields. One is a 2-byte unsigned integer
286 * that will hold years up to 65535. The other, which is deprecated,
287 * holds the date in text format, and will hold years up to 9999.
288 *
289 * The integer is
290 * "png_uint_16 year" in png_time_struct.
291 *
292 * The string is
293 * "char time_buffer[29]" in png_struct. This is no longer used
294 * in libpng-1.6.x and will be removed from libpng-1.7.0.
295 *
296 * There are seven time-related functions:
297 * png.c: png_convert_to_rfc_1123_buffer() in png.c
298 * (formerly png_convert_to_rfc_1123() prior to libpng-1.5.x and
299 * png_convert_to_rfc_1152() in error prior to libpng-0.98)
300 * png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
301 * png_convert_from_time_t() in pngwrite.c
302 * png_get_tIME() in pngget.c
303 * png_handle_tIME() in pngrutil.c, called in pngread.c
304 * png_set_tIME() in pngset.c
305 * png_write_tIME() in pngwutil.c, called in pngwrite.c
306 *
307 * All handle dates properly in a Y2K environment. The
308 * png_convert_from_time_t() function calls gmtime() to convert from system
309 * clock time, which returns (year - 1900), which we properly convert to
310 * the full 4-digit year. There is a possibility that libpng applications
311 * are not passing 4-digit years into the png_convert_to_rfc_1123_buffer()
312 * function, or that they are incorrectly passing only a 2-digit year
313 * instead of "year - 1900" into the png_convert_from_struct_tm() function,
314 * but this is not under our control. The libpng documentation has always
315 * stated that it works with 4-digit years, and the APIs have been
316 * documented as such.
317 *
318 * The tIME chunk itself is also Y2K compliant. It uses a 2-byte unsigned
319 * integer to hold the year, and can hold years as large as 65535.
320 *
321 * zlib, upon which libpng depends, is also Y2K compliant. It contains
322 * no date-related code.
323 *
324 * Glenn Randers-Pehrson
325 * libpng maintainer
326 * PNG Development Group
327 */
328
329 #ifndef PNG_H
330 #define PNG_H
331
332 /* This is not the place to learn how to use libpng. The file libpng-manual.txt
333 * describes how to use libpng, and the file example.c summarizes it
334 * with some code on which to build. This file is useful for looking
335 * at the actual function definitions and structure components. If that
336 * file has been stripped from your copy of libpng, you can find it at
337 * <http://www.libpng.org/pub/png/libpng-manual.txt>
338 *
339 * If you just need to read a PNG file and don't want to read the documentation
340 * skip to the end of this file and read the section entitled 'simplified API'.
341 */
342
343 /* Version information for png.h - this should match the version in png.c */
344 #define PNG_LIBPNG_VER_STRING "1.6.23"
345 #define PNG_HEADER_VERSION_STRING \
346 " libpng version 1.6.23 - June 9, 2016\n"
347
348 #define PNG_LIBPNG_VER_SONUM 16
349 #define PNG_LIBPNG_VER_DLLNUM 16
350
351 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
352 #define PNG_LIBPNG_VER_MAJOR 1
353 #define PNG_LIBPNG_VER_MINOR 6
354 #define PNG_LIBPNG_VER_RELEASE 23
355
356 /* This should match the numeric part of the final component of
357 * PNG_LIBPNG_VER_STRING, omitting any leading zero:
358 */
359
360 #define PNG_LIBPNG_VER_BUILD 0
361
362 /* Release Status */
363 #define PNG_LIBPNG_BUILD_ALPHA 1
364 #define PNG_LIBPNG_BUILD_BETA 2
365 #define PNG_LIBPNG_BUILD_RC 3
366 #define PNG_LIBPNG_BUILD_STABLE 4
367 #define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7
368
369 /* Release-Specific Flags */
370 #define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with
371 PNG_LIBPNG_BUILD_STABLE only */
372 #define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with
373 PNG_LIBPNG_BUILD_SPECIAL */
374 #define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with
375 PNG_LIBPNG_BUILD_PRIVATE */
376
377 #define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE
378
379 /* Careful here. At one time, Guy wanted to use 082, but that would be octal.
380 * We must not include leading zeros.
381 * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only
382 * version 1.0.0 was mis-numbered 100 instead of 10000). From
383 * version 1.0.1 it's xxyyzz, where x=major, y=minor, z=release
384 */
385 #define PNG_LIBPNG_VER 10623 /* 1.6.23 */
386
387 /* Library configuration: these options cannot be changed after
388 * the library has been built.
389 */
390 #ifndef PNGLCONF_H
391 /* If pnglibconf.h is missing, you can
392 * copy scripts/pnglibconf.h.prebuilt to pnglibconf.h
393 */
394 # include "pnglibconf.h"
395 #endif
396
397 #ifndef PNG_VERSION_INFO_ONLY
398 /* Machine specific configuration. */
399 # include "pngconf.h"
400 #endif
401
402 /*
403 * Added at libpng-1.2.8
404 *
405 * Ref MSDN: Private as priority over Special
406 * VS_FF_PRIVATEBUILD File *was not* built using standard release
407 * procedures. If this value is given, the StringFileInfo block must
408 * contain a PrivateBuild string.
409 *
410 * VS_FF_SPECIALBUILD File *was* built by the original company using
411 * standard release procedures but is a variation of the standard
412 * file of the same version number. If this value is given, the
413 * StringFileInfo block must contain a SpecialBuild string.
414 */
415
416 #ifdef PNG_USER_PRIVATEBUILD /* From pnglibconf.h */
417 # define PNG_LIBPNG_BUILD_TYPE \
418 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE)
419 #else
420 # ifdef PNG_LIBPNG_SPECIALBUILD
421 # define PNG_LIBPNG_BUILD_TYPE \
422 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL)
423 # else
424 # define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE)
425 # endif
426 #endif
427
428 #ifndef PNG_VERSION_INFO_ONLY
429
430 /* Inhibit C++ name-mangling for libpng functions but not for system calls. */
431 #ifdef __cplusplus
432 extern "C" {
433 #endif /* __cplusplus */
434
435 /* Version information for C files, stored in png.c. This had better match
436 * the version above.
437 */
438 #define png_libpng_ver png_get_header_ver(NULL)
439
440 /* This file is arranged in several sections:
441 *
442 * 1. [omitted]
443 * 2. Any configuration options that can be specified by for the application
444 * code when it is built. (Build time configuration is in pnglibconf.h)
445 * 3. Type definitions (base types are defined in pngconf.h), structure
446 * definitions.
447 * 4. Exported library functions.
448 * 5. Simplified API.
449 * 6. Implementation options.
450 *
451 * The library source code has additional files (principally pngpriv.h) that
452 * allow configuration of the library.
453 */
454
455 /* Section 1: [omitted] */
456
457 /* Section 2: run time configuration
458 * See pnglibconf.h for build time configuration
459 *
460 * Run time configuration allows the application to choose between
461 * implementations of certain arithmetic APIs. The default is set
462 * at build time and recorded in pnglibconf.h, but it is safe to
463 * override these (and only these) settings. Note that this won't
464 * change what the library does, only application code, and the
465 * settings can (and probably should) be made on a per-file basis
466 * by setting the #defines before including png.h
467 *
468 * Use macros to read integers from PNG data or use the exported
469 * functions?
470 * PNG_USE_READ_MACROS: use the macros (see below) Note that
471 * the macros evaluate their argument multiple times.
472 * PNG_NO_USE_READ_MACROS: call the relevant library function.
473 *
474 * Use the alternative algorithm for compositing alpha samples that
475 * does not use division?
476 * PNG_READ_COMPOSITE_NODIV_SUPPORTED: use the 'no division'
477 * algorithm.
478 * PNG_NO_READ_COMPOSITE_NODIV: use the 'division' algorithm.
479 *
480 * How to handle benign errors if PNG_ALLOW_BENIGN_ERRORS is
481 * false?
482 * PNG_ALLOW_BENIGN_ERRORS: map calls to the benign error
483 * APIs to png_warning.
484 * Otherwise the calls are mapped to png_error.
485 */
486
487 /* Section 3: type definitions, including structures and compile time
488 * constants.
489 * See pngconf.h for base types that vary by machine/system
490 */
491
492 /* This triggers a compiler error in png.c, if png.c and png.h
493 * do not agree upon the version number.
494 */
495 typedef char* png_libpng_version_1_6_23;
496
497 /* Basic control structions. Read libpng-manual.txt or libpng.3 for more info.
498 *
499 * png_struct is the cache of information used while reading or writing a single
500 * PNG file. One of these is always required, although the simplified API
501 * (below) hides the creation and destruction of it.
502 */
503 typedef struct png_struct_def png_struct;
504 typedef const png_struct * png_const_structp;
505 typedef png_struct * png_structp;
506 typedef png_struct * * png_structpp;
507
508 /* png_info contains information read from or to be written to a PNG file. One
509 * or more of these must exist while reading or creating a PNG file. The
510 * information is not used by libpng during read but is used to control what
511 * gets written when a PNG file is created. "png_get_" function calls read
512 * information during read and "png_set_" functions calls write information
513 * when creating a PNG.
514 * been moved into a separate header file that is not accessible to
515 * applications. Read libpng-manual.txt or libpng.3 for more info.
516 */
517 typedef struct png_info_def png_info;
518 typedef png_info * png_infop;
519 typedef const png_info * png_const_infop;
520 typedef png_info * * png_infopp;
521
522 /* Types with names ending 'p' are pointer types. The corresponding types with
523 * names ending 'rp' are identical pointer types except that the pointer is
524 * marked 'restrict', which means that it is the only pointer to the object
525 * passed to the function. Applications should not use the 'restrict' types;
526 * it is always valid to pass 'p' to a pointer with a function argument of the
527 * corresponding 'rp' type. Different compilers have different rules with
528 * regard to type matching in the presence of 'restrict'. For backward
529 * compatibility libpng callbacks never have 'restrict' in their parameters and,
530 * consequentially, writing portable application code is extremely difficult if
531 * an attempt is made to use 'restrict'.
532 */
533 typedef png_struct * PNG_RESTRICT png_structrp;
534 typedef const png_struct * PNG_RESTRICT png_const_structrp;
535 typedef png_info * PNG_RESTRICT png_inforp;
536 typedef const png_info * PNG_RESTRICT png_const_inforp;
537
538 /* Three color definitions. The order of the red, green, and blue, (and the
539 * exact size) is not important, although the size of the fields need to
540 * be png_byte or png_uint_16 (as defined below).
541 */
542 typedef struct png_color_struct
543 {
544 png_byte red;
545 png_byte green;
546 png_byte blue;
547 } png_color;
548 typedef png_color * png_colorp;
549 typedef const png_color * png_const_colorp;
550 typedef png_color * * png_colorpp;
551
552 typedef struct png_color_16_struct
553 {
554 png_byte index; /* used for palette files */
555 png_uint_16 red; /* for use in red green blue files */
556 png_uint_16 green;
557 png_uint_16 blue;
558 png_uint_16 gray; /* for use in grayscale files */
559 } png_color_16;
560 typedef png_color_16 * png_color_16p;
561 typedef const png_color_16 * png_const_color_16p;
562 typedef png_color_16 * * png_color_16pp;
563
564 typedef struct png_color_8_struct
565 {
566 png_byte red; /* for use in red green blue files */
567 png_byte green;
568 png_byte blue;
569 png_byte gray; /* for use in grayscale files */
570 png_byte alpha; /* for alpha channel files */
571 } png_color_8;
572 typedef png_color_8 * png_color_8p;
573 typedef const png_color_8 * png_const_color_8p;
574 typedef png_color_8 * * png_color_8pp;
575
576 /*
577 * The following two structures are used for the in-core representation
578 * of sPLT chunks.
579 */
580 typedef struct png_sPLT_entry_struct
581 {
582 png_uint_16 red;
583 png_uint_16 green;
584 png_uint_16 blue;
585 png_uint_16 alpha;
586 png_uint_16 frequency;
587 } png_sPLT_entry;
588 typedef png_sPLT_entry * png_sPLT_entryp;
589 typedef const png_sPLT_entry * png_const_sPLT_entryp;
590 typedef png_sPLT_entry * * png_sPLT_entrypp;
591
592 /* When the depth of the sPLT palette is 8 bits, the color and alpha samples
593 * occupy the LSB of their respective members, and the MSB of each member
594 * is zero-filled. The frequency member always occupies the full 16 bits.
595 */
596
597 typedef struct png_sPLT_struct
598 {
599 png_charp name; /* palette name */
600 png_byte depth; /* depth of palette samples */
601 png_sPLT_entryp entries; /* palette entries */
602 png_int_32 nentries; /* number of palette entries */
603 } png_sPLT_t;
604 typedef png_sPLT_t * png_sPLT_tp;
605 typedef const png_sPLT_t * png_const_sPLT_tp;
606 typedef png_sPLT_t * * png_sPLT_tpp;
607
608 #ifdef PNG_TEXT_SUPPORTED
609 /* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,
610 * and whether that contents is compressed or not. The "key" field
611 * points to a regular zero-terminated C string. The "text" fields can be a
612 * regular C string, an empty string, or a NULL pointer.
613 * However, the structure returned by png_get_text() will always contain
614 * the "text" field as a regular zero-terminated C string (possibly
615 * empty), never a NULL pointer, so it can be safely used in printf() and
616 * other string-handling functions. Note that the "itxt_length", "lang", and
617 * "lang_key" members of the structure only exist when the library is built
618 * with iTXt chunk support. Prior to libpng-1.4.0 the library was built by
619 * default without iTXt support. Also note that when iTXt *is* supported,
620 * the "lang" and "lang_key" fields contain NULL pointers when the
621 * "compression" field contains * PNG_TEXT_COMPRESSION_NONE or
622 * PNG_TEXT_COMPRESSION_zTXt. Note that the "compression value" is not the
623 * same as what appears in the PNG tEXt/zTXt/iTXt chunk's "compression flag"
624 * which is always 0 or 1, or its "compression method" which is always 0.
625 */
626 typedef struct png_text_struct
627 {
628 int compression; /* compression value:
629 -1: tEXt, none
630 0: zTXt, deflate
631 1: iTXt, none
632 2: iTXt, deflate */
633 png_charp key; /* keyword, 1-79 character description of "text" */
634 png_charp text; /* comment, may be an empty string (ie "")
635 or a NULL pointer */
636 png_size_t text_length; /* length of the text string */
637 png_size_t itxt_length; /* length of the itxt string */
638 png_charp lang; /* language code, 0-79 characters
639 or a NULL pointer */
640 png_charp lang_key; /* keyword translated UTF-8 string, 0 or more
641 chars or a NULL pointer */
642 } png_text;
643 typedef png_text * png_textp;
644 typedef const png_text * png_const_textp;
645 typedef png_text * * png_textpp;
646 #endif
647
648 /* Supported compression types for text in PNG files (tEXt, and zTXt).
649 * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */
650 #define PNG_TEXT_COMPRESSION_NONE_WR -3
651 #define PNG_TEXT_COMPRESSION_zTXt_WR -2
652 #define PNG_TEXT_COMPRESSION_NONE -1
653 #define PNG_TEXT_COMPRESSION_zTXt 0
654 #define PNG_ITXT_COMPRESSION_NONE 1
655 #define PNG_ITXT_COMPRESSION_zTXt 2
656 #define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */
657
658 /* png_time is a way to hold the time in an machine independent way.
659 * Two conversions are provided, both from time_t and struct tm. There
660 * is no portable way to convert to either of these structures, as far
661 * as I know. If you know of a portable way, send it to me. As a side
662 * note - PNG has always been Year 2000 compliant!
663 */
664 typedef struct png_time_struct
665 {
666 png_uint_16 year; /* full year, as in, 1995 */
667 png_byte month; /* month of year, 1 - 12 */
668 png_byte day; /* day of month, 1 - 31 */
669 png_byte hour; /* hour of day, 0 - 23 */
670 png_byte minute; /* minute of hour, 0 - 59 */
671 png_byte second; /* second of minute, 0 - 60 (for leap seconds) */
672 } png_time;
673 typedef png_time * png_timep;
674 typedef const png_time * png_const_timep;
675 typedef png_time * * png_timepp;
676
677 #if defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) ||\
678 defined(PNG_USER_CHUNKS_SUPPORTED)
679 /* png_unknown_chunk is a structure to hold queued chunks for which there is
680 * no specific support. The idea is that we can use this to queue
681 * up private chunks for output even though the library doesn't actually
682 * know about their semantics.
683 *
684 * The data in the structure is set by libpng on read and used on write.
685 */
686 typedef struct png_unknown_chunk_t
687 {
688 png_byte name[5]; /* Textual chunk name with '\0' terminator */
689 png_byte *data; /* Data, should not be modified on read! */
690 png_size_t size;
691
692 /* On write 'location' must be set using the flag values listed below.
693 * Notice that on read it is set by libpng however the values stored have
694 * more bits set than are listed below. Always treat the value as a
695 * bitmask. On write set only one bit - setting multiple bits may cause the
696 * chunk to be written in multiple places.
697 */
698 png_byte location; /* mode of operation at read time */
699 }
700 png_unknown_chunk;
701
702 typedef png_unknown_chunk * png_unknown_chunkp;
703 typedef const png_unknown_chunk * png_const_unknown_chunkp;
704 typedef png_unknown_chunk * * png_unknown_chunkpp;
705 #endif
706
707 /* Flag values for the unknown chunk location byte. */
708 #define PNG_HAVE_IHDR 0x01
709 #define PNG_HAVE_PLTE 0x02
710 #define PNG_AFTER_IDAT 0x08
711
712 /* Maximum positive integer used in PNG is (2^31)-1 */
713 #define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL)
714 #define PNG_UINT_32_MAX ((png_uint_32)(-1))
715 #define PNG_SIZE_MAX ((png_size_t)(-1))
716
717 /* These are constants for fixed point values encoded in the
718 * PNG specification manner (x100000)
719 */
720 #define PNG_FP_1 100000
721 #define PNG_FP_HALF 50000
722 #define PNG_FP_MAX ((png_fixed_point)0x7fffffffL)
723 #define PNG_FP_MIN (-PNG_FP_MAX)
724
725 /* These describe the color_type field in png_info. */
726 /* color type masks */
727 #define PNG_COLOR_MASK_PALETTE 1
728 #define PNG_COLOR_MASK_COLOR 2
729 #define PNG_COLOR_MASK_ALPHA 4
730
731 /* color types. Note that not all combinations are legal */
732 #define PNG_COLOR_TYPE_GRAY 0
733 #define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
734 #define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR)
735 #define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
736 #define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
737 /* aliases */
738 #define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA
739 #define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA
740
741 /* This is for compression type. PNG 1.0-1.2 only define the single type. */
742 #define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */
743 #define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE
744
745 /* This is for filter type. PNG 1.0-1.2 only define the single type. */
746 #define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */
747 #define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */
748 #define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE
749
750 /* These are for the interlacing type. These values should NOT be changed. */
751 #define PNG_INTERLACE_NONE 0 /* Non-interlaced image */
752 #define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */
753 #define PNG_INTERLACE_LAST 2 /* Not a valid value */
754
755 /* These are for the oFFs chunk. These values should NOT be changed. */
756 #define PNG_OFFSET_PIXEL 0 /* Offset in pixels */
757 #define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */
758 #define PNG_OFFSET_LAST 2 /* Not a valid value */
759
760 /* These are for the pCAL chunk. These values should NOT be changed. */
761 #define PNG_EQUATION_LINEAR 0 /* Linear transformation */
762 #define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */
763 #define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */
764 #define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */
765 #define PNG_EQUATION_LAST 4 /* Not a valid value */
766
767 /* These are for the sCAL chunk. These values should NOT be changed. */
768 #define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */
769 #define PNG_SCALE_METER 1 /* meters per pixel */
770 #define PNG_SCALE_RADIAN 2 /* radians per pixel */
771 #define PNG_SCALE_LAST 3 /* Not a valid value */
772
773 /* These are for the pHYs chunk. These values should NOT be changed. */
774 #define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */
775 #define PNG_RESOLUTION_METER 1 /* pixels/meter */
776 #define PNG_RESOLUTION_LAST 2 /* Not a valid value */
777
778 /* These are for the sRGB chunk. These values should NOT be changed. */
779 #define PNG_sRGB_INTENT_PERCEPTUAL 0
780 #define PNG_sRGB_INTENT_RELATIVE 1
781 #define PNG_sRGB_INTENT_SATURATION 2
782 #define PNG_sRGB_INTENT_ABSOLUTE 3
783 #define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */
784
785 /* This is for text chunks */
786 #define PNG_KEYWORD_MAX_LENGTH 79
787
788 /* Maximum number of entries in PLTE/sPLT/tRNS arrays */
789 #define PNG_MAX_PALETTE_LENGTH 256
790
791 /* These determine if an ancillary chunk's data has been successfully read
792 * from the PNG header, or if the application has filled in the corresponding
793 * data in the info_struct to be written into the output file. The values
794 * of the PNG_INFO_<chunk> defines should NOT be changed.
795 */
796 #define PNG_INFO_gAMA 0x0001U
797 #define PNG_INFO_sBIT 0x0002U
798 #define PNG_INFO_cHRM 0x0004U
799 #define PNG_INFO_PLTE 0x0008U
800 #define PNG_INFO_tRNS 0x0010U
801 #define PNG_INFO_bKGD 0x0020U
802 #define PNG_INFO_hIST 0x0040U
803 #define PNG_INFO_pHYs 0x0080U
804 #define PNG_INFO_oFFs 0x0100U
805 #define PNG_INFO_tIME 0x0200U
806 #define PNG_INFO_pCAL 0x0400U
807 #define PNG_INFO_sRGB 0x0800U /* GR-P, 0.96a */
808 #define PNG_INFO_iCCP 0x1000U /* ESR, 1.0.6 */
809 #define PNG_INFO_sPLT 0x2000U /* ESR, 1.0.6 */
810 #define PNG_INFO_sCAL 0x4000U /* ESR, 1.0.6 */
811 #define PNG_INFO_IDAT 0x8000U /* ESR, 1.0.6 */
812
813 /* This is used for the transformation routines, as some of them
814 * change these values for the row. It also should enable using
815 * the routines for other purposes.
816 */
817 typedef struct png_row_info_struct
818 {
819 png_uint_32 width; /* width of row */
820 png_size_t rowbytes; /* number of bytes in row */
821 png_byte color_type; /* color type of row */
822 png_byte bit_depth; /* bit depth of row */
823 png_byte channels; /* number of channels (1, 2, 3, or 4) */
824 png_byte pixel_depth; /* bits per pixel (depth * channels) */
825 } png_row_info;
826
827 typedef png_row_info * png_row_infop;
828 typedef png_row_info * * png_row_infopp;
829
830 /* These are the function types for the I/O functions and for the functions
831 * that allow the user to override the default I/O functions with his or her
832 * own. The png_error_ptr type should match that of user-supplied warning
833 * and error functions, while the png_rw_ptr type should match that of the
834 * user read/write data functions. Note that the 'write' function must not
835 * modify the buffer it is passed. The 'read' function, on the other hand, is
836 * expected to return the read data in the buffer.
837 */
838 typedef PNG_CALLBACK(void, *png_error_ptr, (png_structp, png_const_charp));
839 typedef PNG_CALLBACK(void, *png_rw_ptr, (png_structp, png_bytep, png_size_t));
840 typedef PNG_CALLBACK(void, *png_flush_ptr, (png_structp));
841 typedef PNG_CALLBACK(void, *png_read_status_ptr, (png_structp, png_uint_32,
842 int));
843 typedef PNG_CALLBACK(void, *png_write_status_ptr, (png_structp, png_uint_32,
844 int));
845
846 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
847 typedef PNG_CALLBACK(void, *png_progressive_info_ptr, (png_structp, png_infop));
848 typedef PNG_CALLBACK(void, *png_progressive_end_ptr, (png_structp, png_infop));
849
850 /* The following callback receives png_uint_32 row_number, int pass for the
851 * png_bytep data of the row. When transforming an interlaced image the
852 * row number is the row number within the sub-image of the interlace pass, so
853 * the value will increase to the height of the sub-image (not the full image)
854 * then reset to 0 for the next pass.
855 *
856 * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
857 * find the output pixel (x,y) given an interlaced sub-image pixel
858 * (row,col,pass). (See below for these macros.)
859 */
860 typedef PNG_CALLBACK(void, *png_progressive_row_ptr, (png_structp, png_bytep,
861 png_uint_32, int));
862 #endif
863
864 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
865 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
866 typedef PNG_CALLBACK(void, *png_user_transform_ptr, (png_structp, png_row_infop,
867 png_bytep));
868 #endif
869
870 #ifdef PNG_USER_CHUNKS_SUPPORTED
871 typedef PNG_CALLBACK(int, *png_user_chunk_ptr, (png_structp,
872 png_unknown_chunkp));
873 #endif
874 #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
875 /* not used anywhere */
876 /* typedef PNG_CALLBACK(void, *png_unknown_chunk_ptr, (png_structp)); */
877 #endif
878
879 #ifdef PNG_SETJMP_SUPPORTED
880 /* This must match the function definition in <setjmp.h>, and the application
881 * must include this before png.h to obtain the definition of jmp_buf. The
882 * function is required to be PNG_NORETURN, but this is not checked. If the
883 * function does return the application will crash via an abort() or similar
884 * system level call.
885 *
886 * If you get a warning here while building the library you may need to make
887 * changes to ensure that pnglibconf.h records the calling convention used by
888 * your compiler. This may be very difficult - try using a different compiler
889 * to build the library!
890 */
891 PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)), typedef);
892 #endif
893
894 /* Transform masks for the high-level interface */
895 #define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */
896 #define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */
897 #define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */
898 #define PNG_TRANSFORM_PACKING 0x0004 /* read and write */
899 #define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */
900 #define PNG_TRANSFORM_EXPAND 0x0010 /* read only */
901 #define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */
902 #define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */
903 #define PNG_TRANSFORM_BGR 0x0080 /* read and write */
904 #define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */
905 #define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */
906 #define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */
907 #define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* write only */
908 /* Added to libpng-1.2.34 */
909 #define PNG_TRANSFORM_STRIP_FILLER_BEFORE PNG_TRANSFORM_STRIP_FILLER
910 #define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */
911 /* Added to libpng-1.4.0 */
912 #define PNG_TRANSFORM_GRAY_TO_RGB 0x2000 /* read only */
913 /* Added to libpng-1.5.4 */
914 #define PNG_TRANSFORM_EXPAND_16 0x4000 /* read only */
915 #if INT_MAX >= 0x8000 /* else this might break */
916 #define PNG_TRANSFORM_SCALE_16 0x8000 /* read only */
917 #endif
918
919 /* Flags for MNG supported features */
920 #define PNG_FLAG_MNG_EMPTY_PLTE 0x01
921 #define PNG_FLAG_MNG_FILTER_64 0x04
922 #define PNG_ALL_MNG_FEATURES 0x05
923
924 /* NOTE: prior to 1.5 these functions had no 'API' style declaration,
925 * this allowed the zlib default functions to be used on Windows
926 * platforms. In 1.5 the zlib default malloc (which just calls malloc and
927 * ignores the first argument) should be completely compatible with the
928 * following.
929 */
930 typedef PNG_CALLBACK(png_voidp, *png_malloc_ptr, (png_structp,
931 png_alloc_size_t));
932 typedef PNG_CALLBACK(void, *png_free_ptr, (png_structp, png_voidp));
933
934 /* Section 4: exported functions
935 * Here are the function definitions most commonly used. This is not
936 * the place to find out how to use libpng. See libpng-manual.txt for the
937 * full explanation, see example.c for the summary. This just provides
938 * a simple one line description of the use of each function.
939 *
940 * The PNG_EXPORT() and PNG_EXPORTA() macros used below are defined in
941 * pngconf.h and in the *.dfn files in the scripts directory.
942 *
943 * PNG_EXPORT(ordinal, type, name, (args));
944 *
945 * ordinal: ordinal that is used while building
946 * *.def files. The ordinal value is only
947 * relevant when preprocessing png.h with
948 * the *.dfn files for building symbol table
949 * entries, and are removed by pngconf.h.
950 * type: return type of the function
951 * name: function name
952 * args: function arguments, with types
953 *
954 * When we wish to append attributes to a function prototype we use
955 * the PNG_EXPORTA() macro instead.
956 *
957 * PNG_EXPORTA(ordinal, type, name, (args), attributes);
958 *
959 * ordinal, type, name, and args: same as in PNG_EXPORT().
960 * attributes: function attributes
961 */
962
963 /* Returns the version number of the library */
964 PNG_EXPORT(1, png_uint_32, png_access_version_number, (void));
965
966 /* Tell lib we have already handled the first <num_bytes> magic bytes.
967 * Handling more than 8 bytes from the beginning of the file is an error.
968 */
969 PNG_EXPORT(2, void, png_set_sig_bytes, (png_structrp png_ptr, int num_bytes));
970
971 /* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
972 * PNG file. Returns zero if the supplied bytes match the 8-byte PNG
973 * signature, and non-zero otherwise. Having num_to_check == 0 or
974 * start > 7 will always fail (ie return non-zero).
975 */
976 PNG_EXPORT(3, int, png_sig_cmp, (png_const_bytep sig, png_size_t start,
977 png_size_t num_to_check));
978
979 /* Simple signature checking function. This is the same as calling
980 * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n).
981 */
982 #define png_check_sig(sig, n) !png_sig_cmp((sig), 0, (n))
983
984 /* Allocate and initialize png_ptr struct for reading, and any other memory. */
985 PNG_EXPORTA(4, png_structp, png_create_read_struct,
986 (png_const_charp user_png_ver, png_voidp error_ptr,
987 png_error_ptr error_fn, png_error_ptr warn_fn),
988 PNG_ALLOCATED);
989
990 /* Allocate and initialize png_ptr struct for writing, and any other memory */
991 PNG_EXPORTA(5, png_structp, png_create_write_struct,
992 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
993 png_error_ptr warn_fn),
994 PNG_ALLOCATED);
995
996 PNG_EXPORT(6, png_size_t, png_get_compression_buffer_size,
997 (png_const_structrp png_ptr));
998
999 PNG_EXPORT(7, void, png_set_compression_buffer_size, (png_structrp png_ptr,
1000 png_size_t size));
1001
1002 /* Moved from pngconf.h in 1.4.0 and modified to ensure setjmp/longjmp
1003 * match up.
1004 */
1005 #ifdef PNG_SETJMP_SUPPORTED
1006 /* This function returns the jmp_buf built in to *png_ptr. It must be
1007 * supplied with an appropriate 'longjmp' function to use on that jmp_buf
1008 * unless the default error function is overridden in which case NULL is
1009 * acceptable. The size of the jmp_buf is checked against the actual size
1010 * allocated by the library - the call will return NULL on a mismatch
1011 * indicating an ABI mismatch.
1012 */
1013 PNG_EXPORT(8, jmp_buf*, png_set_longjmp_fn, (png_structrp png_ptr,
1014 png_longjmp_ptr longjmp_fn, size_t jmp_buf_size));
1015 # define png_jmpbuf(png_ptr) \
1016 (*png_set_longjmp_fn((png_ptr), longjmp, (sizeof (jmp_buf))))
1017 #else
1018 # define png_jmpbuf(png_ptr) \
1019 (LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP)
1020 #endif
1021 /* This function should be used by libpng applications in place of
1022 * longjmp(png_ptr->jmpbuf, val). If longjmp_fn() has been set, it
1023 * will use it; otherwise it will call PNG_ABORT(). This function was
1024 * added in libpng-1.5.0.
1025 */
1026 PNG_EXPORTA(9, void, png_longjmp, (png_const_structrp png_ptr, int val),
1027 PNG_NORETURN);
1028
1029 #ifdef PNG_READ_SUPPORTED
1030 /* Reset the compression stream */
1031 PNG_EXPORTA(10, int, png_reset_zstream, (png_structrp png_ptr), PNG_DEPRECATED);
1032 #endif
1033
1034 /* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */
1035 #ifdef PNG_USER_MEM_SUPPORTED
1036 PNG_EXPORTA(11, png_structp, png_create_read_struct_2,
1037 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
1038 png_error_ptr warn_fn,
1039 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn),
1040 PNG_ALLOCATED);
1041 PNG_EXPORTA(12, png_structp, png_create_write_struct_2,
1042 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
1043 png_error_ptr warn_fn,
1044 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn),
1045 PNG_ALLOCATED);
1046 #endif
1047
1048 /* Write the PNG file signature. */
1049 PNG_EXPORT(13, void, png_write_sig, (png_structrp png_ptr));
1050
1051 /* Write a PNG chunk - size, type, (optional) data, CRC. */
1052 PNG_EXPORT(14, void, png_write_chunk, (png_structrp png_ptr, png_const_bytep
1053 chunk_name, png_const_bytep data, png_size_t length));
1054
1055 /* Write the start of a PNG chunk - length and chunk name. */
1056 PNG_EXPORT(15, void, png_write_chunk_start, (png_structrp png_ptr,
1057 png_const_bytep chunk_name, png_uint_32 length));
1058
1059 /* Write the data of a PNG chunk started with png_write_chunk_start(). */
1060 PNG_EXPORT(16, void, png_write_chunk_data, (png_structrp png_ptr,
1061 png_const_bytep data, png_size_t length));
1062
1063 /* Finish a chunk started with png_write_chunk_start() (includes CRC). */
1064 PNG_EXPORT(17, void, png_write_chunk_end, (png_structrp png_ptr));
1065
1066 /* Allocate and initialize the info structure */
1067 PNG_EXPORTA(18, png_infop, png_create_info_struct, (png_const_structrp png_ptr),
1068 PNG_ALLOCATED);
1069
1070 /* DEPRECATED: this function allowed init structures to be created using the
1071 * default allocation method (typically malloc). Use is deprecated in 1.6.0 and
1072 * the API will be removed in the future.
1073 */
1074 PNG_EXPORTA(19, void, png_info_init_3, (png_infopp info_ptr,
1075 png_size_t png_info_struct_size), PNG_DEPRECATED);
1076
1077 /* Writes all the PNG information before the image. */
1078 PNG_EXPORT(20, void, png_write_info_before_PLTE,
1079 (png_structrp png_ptr, png_const_inforp info_ptr));
1080 PNG_EXPORT(21, void, png_write_info,
1081 (png_structrp png_ptr, png_const_inforp info_ptr));
1082
1083 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1084 /* Read the information before the actual image data. */
1085 PNG_EXPORT(22, void, png_read_info,
1086 (png_structrp png_ptr, png_inforp info_ptr));
1087 #endif
1088
1089 #ifdef PNG_TIME_RFC1123_SUPPORTED
1090 /* Convert to a US string format: there is no localization support in this
1091 * routine. The original implementation used a 29 character buffer in
1092 * png_struct, this will be removed in future versions.
1093 */
1094 #if PNG_LIBPNG_VER < 10700
1095 /* To do: remove this from libpng17 (and from libpng17/png.c and pngstruct.h) */
1096 PNG_EXPORTA(23, png_const_charp, png_convert_to_rfc1123, (png_structrp png_ptr,
1097 png_const_timep ptime),PNG_DEPRECATED);
1098 #endif
1099 PNG_EXPORT(241, int, png_convert_to_rfc1123_buffer, (char out[29],
1100 png_const_timep ptime));
1101 #endif
1102
1103 #ifdef PNG_CONVERT_tIME_SUPPORTED
1104 /* Convert from a struct tm to png_time */
1105 PNG_EXPORT(24, void, png_convert_from_struct_tm, (png_timep ptime,
1106 const struct tm * ttime));
1107
1108 /* Convert from time_t to png_time. Uses gmtime() */
1109 PNG_EXPORT(25, void, png_convert_from_time_t, (png_timep ptime, time_t ttime));
1110 #endif /* CONVERT_tIME */
1111
1112 #ifdef PNG_READ_EXPAND_SUPPORTED
1113 /* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
1114 PNG_EXPORT(26, void, png_set_expand, (png_structrp png_ptr));
1115 PNG_EXPORT(27, void, png_set_expand_gray_1_2_4_to_8, (png_structrp png_ptr));
1116 PNG_EXPORT(28, void, png_set_palette_to_rgb, (png_structrp png_ptr));
1117 PNG_EXPORT(29, void, png_set_tRNS_to_alpha, (png_structrp png_ptr));
1118 #endif
1119
1120 #ifdef PNG_READ_EXPAND_16_SUPPORTED
1121 /* Expand to 16-bit channels, forces conversion of palette to RGB and expansion
1122 * of a tRNS chunk if present.
1123 */
1124 PNG_EXPORT(221, void, png_set_expand_16, (png_structrp png_ptr));
1125 #endif
1126
1127 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
1128 /* Use blue, green, red order for pixels. */
1129 PNG_EXPORT(30, void, png_set_bgr, (png_structrp png_ptr));
1130 #endif
1131
1132 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
1133 /* Expand the grayscale to 24-bit RGB if necessary. */
1134 PNG_EXPORT(31, void, png_set_gray_to_rgb, (png_structrp png_ptr));
1135 #endif
1136
1137 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1138 /* Reduce RGB to grayscale. */
1139 #define PNG_ERROR_ACTION_NONE 1
1140 #define PNG_ERROR_ACTION_WARN 2
1141 #define PNG_ERROR_ACTION_ERROR 3
1142 #define PNG_RGB_TO_GRAY_DEFAULT (-1)/*for red/green coefficients*/
1143
1144 PNG_FP_EXPORT(32, void, png_set_rgb_to_gray, (png_structrp png_ptr,
1145 int error_action, double red, double green))
1146 PNG_FIXED_EXPORT(33, void, png_set_rgb_to_gray_fixed, (png_structrp png_ptr,
1147 int error_action, png_fixed_point red, png_fixed_point green))
1148
1149 PNG_EXPORT(34, png_byte, png_get_rgb_to_gray_status, (png_const_structrp
1150 png_ptr));
1151 #endif
1152
1153 #ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED
1154 PNG_EXPORT(35, void, png_build_grayscale_palette, (int bit_depth,
1155 png_colorp palette));
1156 #endif
1157
1158 #ifdef PNG_READ_ALPHA_MODE_SUPPORTED
1159 /* How the alpha channel is interpreted - this affects how the color channels
1160 * of a PNG file are returned to the calling application when an alpha channel,
1161 * or a tRNS chunk in a palette file, is present.
1162 *
1163 * This has no effect on the way pixels are written into a PNG output
1164 * datastream. The color samples in a PNG datastream are never premultiplied
1165 * with the alpha samples.
1166 *
1167 * The default is to return data according to the PNG specification: the alpha
1168 * channel is a linear measure of the contribution of the pixel to the
1169 * corresponding composited pixel, and the color channels are unassociated
1170 * (not premultiplied). The gamma encoded color channels must be scaled
1171 * according to the contribution and to do this it is necessary to undo
1172 * the encoding, scale the color values, perform the composition and reencode
1173 * the values. This is the 'PNG' mode.
1174 *
1175 * The alternative is to 'associate' the alpha with the color information by
1176 * storing color channel values that have been scaled by the alpha.
1177 * image. These are the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' modes
1178 * (the latter being the two common names for associated alpha color channels).
1179 *
1180 * For the 'OPTIMIZED' mode, a pixel is treated as opaque only if the alpha
1181 * value is equal to the maximum value.
1182 *
1183 * The final choice is to gamma encode the alpha channel as well. This is
1184 * broken because, in practice, no implementation that uses this choice
1185 * correctly undoes the encoding before handling alpha composition. Use this
1186 * choice only if other serious errors in the software or hardware you use
1187 * mandate it; the typical serious error is for dark halos to appear around
1188 * opaque areas of the composited PNG image because of arithmetic overflow.
1189 *
1190 * The API function png_set_alpha_mode specifies which of these choices to use
1191 * with an enumerated 'mode' value and the gamma of the required output:
1192 */
1193 #define PNG_ALPHA_PNG 0 /* according to the PNG standard */
1194 #define PNG_ALPHA_STANDARD 1 /* according to Porter/Duff */
1195 #define PNG_ALPHA_ASSOCIATED 1 /* as above; this is the normal practice */
1196 #define PNG_ALPHA_PREMULTIPLIED 1 /* as above */
1197 #define PNG_ALPHA_OPTIMIZED 2 /* 'PNG' for opaque pixels, else 'STANDARD' */
1198 #define PNG_ALPHA_BROKEN 3 /* the alpha channel is gamma encoded */
1199
1200 PNG_FP_EXPORT(227, void, png_set_alpha_mode, (png_structrp png_ptr, int mode,
1201 double output_gamma))
1202 PNG_FIXED_EXPORT(228, void, png_set_alpha_mode_fixed, (png_structrp png_ptr,
1203 int mode, png_fixed_point output_gamma))
1204 #endif
1205
1206 #if defined(PNG_GAMMA_SUPPORTED) || defined(PNG_READ_ALPHA_MODE_SUPPORTED)
1207 /* The output_gamma value is a screen gamma in libpng terminology: it expresses
1208 * how to decode the output values, not how they are encoded.
1209 */
1210 #define PNG_DEFAULT_sRGB -1 /* sRGB gamma and color space */
1211 #define PNG_GAMMA_MAC_18 -2 /* Old Mac '1.8' gamma and color space */
1212 #define PNG_GAMMA_sRGB 220000 /* Television standards--matches sRGB gamma */
1213 #define PNG_GAMMA_LINEAR PNG_FP_1 /* Linear */
1214 #endif
1215
1216 /* The following are examples of calls to png_set_alpha_mode to achieve the
1217 * required overall gamma correction and, where necessary, alpha
1218 * premultiplication.
1219 *
1220 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
1221 * This is the default libpng handling of the alpha channel - it is not
1222 * pre-multiplied into the color components. In addition the call states
1223 * that the output is for a sRGB system and causes all PNG files without gAMA
1224 * chunks to be assumed to be encoded using sRGB.
1225 *
1226 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
1227 * In this case the output is assumed to be something like an sRGB conformant
1228 * display preceeded by a power-law lookup table of power 1.45. This is how
1229 * early Mac systems behaved.
1230 *
1231 * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR);
1232 * This is the classic Jim Blinn approach and will work in academic
1233 * environments where everything is done by the book. It has the shortcoming
1234 * of assuming that input PNG data with no gamma information is linear - this
1235 * is unlikely to be correct unless the PNG files where generated locally.
1236 * Most of the time the output precision will be so low as to show
1237 * significant banding in dark areas of the image.
1238 *
1239 * png_set_expand_16(pp);
1240 * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB);
1241 * This is a somewhat more realistic Jim Blinn inspired approach. PNG files
1242 * are assumed to have the sRGB encoding if not marked with a gamma value and
1243 * the output is always 16 bits per component. This permits accurate scaling
1244 * and processing of the data. If you know that your input PNG files were
1245 * generated locally you might need to replace PNG_DEFAULT_sRGB with the
1246 * correct value for your system.
1247 *
1248 * png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB);
1249 * If you just need to composite the PNG image onto an existing background
1250 * and if you control the code that does this you can use the optimization
1251 * setting. In this case you just copy completely opaque pixels to the
1252 * output. For pixels that are not completely transparent (you just skip
1253 * those) you do the composition math using png_composite or png_composite_16
1254 * below then encode the resultant 8-bit or 16-bit values to match the output
1255 * encoding.
1256 *
1257 * Other cases
1258 * If neither the PNG nor the standard linear encoding work for you because
1259 * of the software or hardware you use then you have a big problem. The PNG
1260 * case will probably result in halos around the image. The linear encoding
1261 * will probably result in a washed out, too bright, image (it's actually too
1262 * contrasty.) Try the ALPHA_OPTIMIZED mode above - this will probably
1263 * substantially reduce the halos. Alternatively try:
1264 *
1265 * png_set_alpha_mode(pp, PNG_ALPHA_BROKEN, PNG_DEFAULT_sRGB);
1266 * This option will also reduce the halos, but there will be slight dark
1267 * halos round the opaque parts of the image where the background is light.
1268 * In the OPTIMIZED mode the halos will be light halos where the background
1269 * is dark. Take your pick - the halos are unavoidable unless you can get
1270 * your hardware/software fixed! (The OPTIMIZED approach is slightly
1271 * faster.)
1272 *
1273 * When the default gamma of PNG files doesn't match the output gamma.
1274 * If you have PNG files with no gamma information png_set_alpha_mode allows
1275 * you to provide a default gamma, but it also sets the ouput gamma to the
1276 * matching value. If you know your PNG files have a gamma that doesn't
1277 * match the output you can take advantage of the fact that
1278 * png_set_alpha_mode always sets the output gamma but only sets the PNG
1279 * default if it is not already set:
1280 *
1281 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
1282 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
1283 * The first call sets both the default and the output gamma values, the
1284 * second call overrides the output gamma without changing the default. This
1285 * is easier than achieving the same effect with png_set_gamma. You must use
1286 * PNG_ALPHA_PNG for the first call - internal checking in png_set_alpha will
1287 * fire if more than one call to png_set_alpha_mode and png_set_background is
1288 * made in the same read operation, however multiple calls with PNG_ALPHA_PNG
1289 * are ignored.
1290 */
1291
1292 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
1293 PNG_EXPORT(36, void, png_set_strip_alpha, (png_structrp png_ptr));
1294 #endif
1295
1296 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
1297 defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
1298 PNG_EXPORT(37, void, png_set_swap_alpha, (png_structrp png_ptr));
1299 #endif
1300
1301 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
1302 defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
1303 PNG_EXPORT(38, void, png_set_invert_alpha, (png_structrp png_ptr));
1304 #endif
1305
1306 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
1307 /* Add a filler byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */
1308 PNG_EXPORT(39, void, png_set_filler, (png_structrp png_ptr, png_uint_32 filler,
1309 int flags));
1310 /* The values of the PNG_FILLER_ defines should NOT be changed */
1311 # define PNG_FILLER_BEFORE 0
1312 # define PNG_FILLER_AFTER 1
1313 /* Add an alpha byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */
1314 PNG_EXPORT(40, void, png_set_add_alpha, (png_structrp png_ptr,
1315 png_uint_32 filler, int flags));
1316 #endif /* READ_FILLER || WRITE_FILLER */
1317
1318 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
1319 /* Swap bytes in 16-bit depth files. */
1320 PNG_EXPORT(41, void, png_set_swap, (png_structrp png_ptr));
1321 #endif
1322
1323 #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
1324 /* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
1325 PNG_EXPORT(42, void, png_set_packing, (png_structrp png_ptr));
1326 #endif
1327
1328 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
1329 defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1330 /* Swap packing order of pixels in bytes. */
1331 PNG_EXPORT(43, void, png_set_packswap, (png_structrp png_ptr));
1332 #endif
1333
1334 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
1335 /* Converts files to legal bit depths. */
1336 PNG_EXPORT(44, void, png_set_shift, (png_structrp png_ptr, png_const_color_8p
1337 true_bits));
1338 #endif
1339
1340 #if defined(PNG_READ_INTERLACING_SUPPORTED) || \
1341 defined(PNG_WRITE_INTERLACING_SUPPORTED)
1342 /* Have the code handle the interlacing. Returns the number of passes.
1343 * MUST be called before png_read_update_info or png_start_read_image,
1344 * otherwise it will not have the desired effect. Note that it is still
1345 * necessary to call png_read_row or png_read_rows png_get_image_height
1346 * times for each pass.
1347 */
1348 PNG_EXPORT(45, int, png_set_interlace_handling, (png_structrp png_ptr));
1349 #endif
1350
1351 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
1352 /* Invert monochrome files */
1353 PNG_EXPORT(46, void, png_set_invert_mono, (png_structrp png_ptr));
1354 #endif
1355
1356 #ifdef PNG_READ_BACKGROUND_SUPPORTED
1357 /* Handle alpha and tRNS by replacing with a background color. Prior to
1358 * libpng-1.5.4 this API must not be called before the PNG file header has been
1359 * read. Doing so will result in unexpected behavior and possible warnings or
1360 * errors if the PNG file contains a bKGD chunk.
1361 */
1362 PNG_FP_EXPORT(47, void, png_set_background, (png_structrp png_ptr,
1363 png_const_color_16p background_color, int background_gamma_code,
1364 int need_expand, double background_gamma))
1365 PNG_FIXED_EXPORT(215, void, png_set_background_fixed, (png_structrp png_ptr,
1366 png_const_color_16p background_color, int background_gamma_code,
1367 int need_expand, png_fixed_point background_gamma))
1368 #endif
1369 #ifdef PNG_READ_BACKGROUND_SUPPORTED
1370 # define PNG_BACKGROUND_GAMMA_UNKNOWN 0
1371 # define PNG_BACKGROUND_GAMMA_SCREEN 1
1372 # define PNG_BACKGROUND_GAMMA_FILE 2
1373 # define PNG_BACKGROUND_GAMMA_UNIQUE 3
1374 #endif
1375
1376 #ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
1377 /* Scale a 16-bit depth file down to 8-bit, accurately. */
1378 PNG_EXPORT(229, void, png_set_scale_16, (png_structrp png_ptr));
1379 #endif
1380
1381 #ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
1382 #define PNG_READ_16_TO_8_SUPPORTED /* Name prior to 1.5.4 */
1383 /* Strip the second byte of information from a 16-bit depth file. */
1384 PNG_EXPORT(48, void, png_set_strip_16, (png_structrp png_ptr));
1385 #endif
1386
1387 #ifdef PNG_READ_QUANTIZE_SUPPORTED
1388 /* Turn on quantizing, and reduce the palette to the number of colors
1389 * available.
1390 */
1391 PNG_EXPORT(49, void, png_set_quantize, (png_structrp png_ptr,
1392 png_colorp palette, int num_palette, int maximum_colors,
1393 png_const_uint_16p histogram, int full_quantize));
1394 #endif
1395
1396 #ifdef PNG_READ_GAMMA_SUPPORTED
1397 /* The threshold on gamma processing is configurable but hard-wired into the
1398 * library. The following is the floating point variant.
1399 */
1400 #define PNG_GAMMA_THRESHOLD (PNG_GAMMA_THRESHOLD_FIXED*.00001)
1401
1402 /* Handle gamma correction. Screen_gamma=(display_exponent).
1403 * NOTE: this API simply sets the screen and file gamma values. It will
1404 * therefore override the value for gamma in a PNG file if it is called after
1405 * the file header has been read - use with care - call before reading the PNG
1406 * file for best results!
1407 *
1408 * These routines accept the same gamma values as png_set_alpha_mode (described
1409 * above). The PNG_GAMMA_ defines and PNG_DEFAULT_sRGB can be passed to either
1410 * API (floating point or fixed.) Notice, however, that the 'file_gamma' value
1411 * is the inverse of a 'screen gamma' value.
1412 */
1413 PNG_FP_EXPORT(50, void, png_set_gamma, (png_structrp png_ptr,
1414 double screen_gamma, double override_file_gamma))
1415 PNG_FIXED_EXPORT(208, void, png_set_gamma_fixed, (png_structrp png_ptr,
1416 png_fixed_point screen_gamma, png_fixed_point override_file_gamma))
1417 #endif
1418
1419 #ifdef PNG_WRITE_FLUSH_SUPPORTED
1420 /* Set how many lines between output flushes - 0 for no flushing */
1421 PNG_EXPORT(51, void, png_set_flush, (png_structrp png_ptr, int nrows));
1422 /* Flush the current PNG output buffer */
1423 PNG_EXPORT(52, void, png_write_flush, (png_structrp png_ptr));
1424 #endif
1425
1426 /* Optional update palette with requested transformations */
1427 PNG_EXPORT(53, void, png_start_read_image, (png_structrp png_ptr));
1428
1429 /* Optional call to update the users info structure */
1430 PNG_EXPORT(54, void, png_read_update_info, (png_structrp png_ptr,
1431 png_inforp info_ptr));
1432
1433 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1434 /* Read one or more rows of image data. */
1435 PNG_EXPORT(55, void, png_read_rows, (png_structrp png_ptr, png_bytepp row,
1436 png_bytepp display_row, png_uint_32 num_rows));
1437 #endif
1438
1439 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1440 /* Read a row of data. */
1441 PNG_EXPORT(56, void, png_read_row, (png_structrp png_ptr, png_bytep row,
1442 png_bytep display_row));
1443 #endif
1444
1445 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1446 /* Read the whole image into memory at once. */
1447 PNG_EXPORT(57, void, png_read_image, (png_structrp png_ptr, png_bytepp image));
1448 #endif
1449
1450 /* Write a row of image data */
1451 PNG_EXPORT(58, void, png_write_row, (png_structrp png_ptr,
1452 png_const_bytep row));
1453
1454 /* Write a few rows of image data: (*row) is not written; however, the type
1455 * is declared as writeable to maintain compatibility with previous versions
1456 * of libpng and to allow the 'display_row' array from read_rows to be passed
1457 * unchanged to write_rows.
1458 */
1459 PNG_EXPORT(59, void, png_write_rows, (png_structrp png_ptr, png_bytepp row,
1460 png_uint_32 num_rows));
1461
1462 /* Write the image data */
1463 PNG_EXPORT(60, void, png_write_image, (png_structrp png_ptr, png_bytepp image));
1464
1465 /* Write the end of the PNG file. */
1466 PNG_EXPORT(61, void, png_write_end, (png_structrp png_ptr,
1467 png_inforp info_ptr));
1468
1469 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1470 /* Read the end of the PNG file. */
1471 PNG_EXPORT(62, void, png_read_end, (png_structrp png_ptr, png_inforp info_ptr));
1472 #endif
1473
1474 /* Free any memory associated with the png_info_struct */
1475 PNG_EXPORT(63, void, png_destroy_info_struct, (png_const_structrp png_ptr,
1476 png_infopp info_ptr_ptr));
1477
1478 /* Free any memory associated with the png_struct and the png_info_structs */
1479 PNG_EXPORT(64, void, png_destroy_read_struct, (png_structpp png_ptr_ptr,
1480 png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr));
1481
1482 /* Free any memory associated with the png_struct and the png_info_structs */
1483 PNG_EXPORT(65, void, png_destroy_write_struct, (png_structpp png_ptr_ptr,
1484 png_infopp info_ptr_ptr));
1485
1486 /* Set the libpng method of handling chunk CRC errors */
1487 PNG_EXPORT(66, void, png_set_crc_action, (png_structrp png_ptr, int crit_action,
1488 int ancil_action));
1489
1490 /* Values for png_set_crc_action() say how to handle CRC errors in
1491 * ancillary and critical chunks, and whether to use the data contained
1492 * therein. Note that it is impossible to "discard" data in a critical
1493 * chunk. For versions prior to 0.90, the action was always error/quit,
1494 * whereas in version 0.90 and later, the action for CRC errors in ancillary
1495 * chunks is warn/discard. These values should NOT be changed.
1496 *
1497 * value action:critical action:ancillary
1498 */
1499 #define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */
1500 #define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */
1501 #define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */
1502 #define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */
1503 #define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */
1504 #define PNG_CRC_NO_CHANGE 5 /* use current value use current value */
1505
1506 #ifdef PNG_WRITE_SUPPORTED
1507 /* These functions give the user control over the scan-line filtering in
1508 * libpng and the compression methods used by zlib. These functions are
1509 * mainly useful for testing, as the defaults should work with most users.
1510 * Those users who are tight on memory or want faster performance at the
1511 * expense of compression can modify them. See the compression library
1512 * header file (zlib.h) for an explination of the compression functions.
1513 */
1514
1515 /* Set the filtering method(s) used by libpng. Currently, the only valid
1516 * value for "method" is 0.
1517 */
1518 PNG_EXPORT(67, void, png_set_filter, (png_structrp png_ptr, int method,
1519 int filters));
1520 #endif /* WRITE */
1521
1522 /* Flags for png_set_filter() to say which filters to use. The flags
1523 * are chosen so that they don't conflict with real filter types
1524 * below, in case they are supplied instead of the #defined constants.
1525 * These values should NOT be changed.
1526 */
1527 #define PNG_NO_FILTERS 0x00
1528 #define PNG_FILTER_NONE 0x08
1529 #define PNG_FILTER_SUB 0x10
1530 #define PNG_FILTER_UP 0x20
1531 #define PNG_FILTER_AVG 0x40
1532 #define PNG_FILTER_PAETH 0x80
1533 #define PNG_FAST_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP)
1534 #define PNG_ALL_FILTERS (PNG_FAST_FILTERS | PNG_FILTER_AVG | PNG_FILTER_PAETH)
1535
1536 /* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
1537 * These defines should NOT be changed.
1538 */
1539 #define PNG_FILTER_VALUE_NONE 0
1540 #define PNG_FILTER_VALUE_SUB 1
1541 #define PNG_FILTER_VALUE_UP 2
1542 #define PNG_FILTER_VALUE_AVG 3
1543 #define PNG_FILTER_VALUE_PAETH 4
1544 #define PNG_FILTER_VALUE_LAST 5
1545
1546 #ifdef PNG_WRITE_SUPPORTED
1547 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* DEPRECATED */
1548 PNG_FP_EXPORT(68, void, png_set_filter_heuristics, (png_structrp png_ptr,
1549 int heuristic_method, int num_weights, png_const_doublep filter_weights,
1550 png_const_doublep filter_costs))
1551 PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed,
1552 (png_structrp png_ptr, int heuristic_method, int num_weights,
1553 png_const_fixed_point_p filter_weights,
1554 png_const_fixed_point_p filter_costs))
1555 #endif /* WRITE_WEIGHTED_FILTER */
1556
1557 /* The following are no longer used and will be removed from libpng-1.7: */
1558 #define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */
1559 #define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */
1560 #define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */
1561 #define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */
1562
1563 /* Set the library compression level. Currently, valid values range from
1564 * 0 - 9, corresponding directly to the zlib compression levels 0 - 9
1565 * (0 - no compression, 9 - "maximal" compression). Note that tests have
1566 * shown that zlib compression levels 3-6 usually perform as well as level 9
1567 * for PNG images, and do considerably fewer caclulations. In the future,
1568 * these values may not correspond directly to the zlib compression levels.
1569 */
1570 #ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED
1571 PNG_EXPORT(69, void, png_set_compression_level, (png_structrp png_ptr,
1572 int level));
1573
1574 PNG_EXPORT(70, void, png_set_compression_mem_level, (png_structrp png_ptr,
1575 int mem_level));
1576
1577 PNG_EXPORT(71, void, png_set_compression_strategy, (png_structrp png_ptr,
1578 int strategy));
1579
1580 /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
1581 * smaller value of window_bits if it can do so safely.
1582 */
1583 PNG_EXPORT(72, void, png_set_compression_window_bits, (png_structrp png_ptr,
1584 int window_bits));
1585
1586 PNG_EXPORT(73, void, png_set_compression_method, (png_structrp png_ptr,
1587 int method));
1588 #endif /* WRITE_CUSTOMIZE_COMPRESSION */
1589
1590 #ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
1591 /* Also set zlib parameters for compressing non-IDAT chunks */
1592 PNG_EXPORT(222, void, png_set_text_compression_level, (png_structrp png_ptr,
1593 int level));
1594
1595 PNG_EXPORT(223, void, png_set_text_compression_mem_level, (png_structrp png_ptr,
1596 int mem_level));
1597
1598 PNG_EXPORT(224, void, png_set_text_compression_strategy, (png_structrp png_ptr,
1599 int strategy));
1600
1601 /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
1602 * smaller value of window_bits if it can do so safely.
1603 */
1604 PNG_EXPORT(225, void, png_set_text_compression_window_bits,
1605 (png_structrp png_ptr, int window_bits));
1606
1607 PNG_EXPORT(226, void, png_set_text_compression_method, (png_structrp png_ptr,
1608 int method));
1609 #endif /* WRITE_CUSTOMIZE_ZTXT_COMPRESSION */
1610 #endif /* WRITE */
1611
1612 /* These next functions are called for input/output, memory, and error
1613 * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c,
1614 * and call standard C I/O routines such as fread(), fwrite(), and
1615 * fprintf(). These functions can be made to use other I/O routines
1616 * at run time for those applications that need to handle I/O in a
1617 * different manner by calling png_set_???_fn(). See libpng-manual.txt for
1618 * more information.
1619 */
1620
1621 #ifdef PNG_STDIO_SUPPORTED
1622 /* Initialize the input/output for the PNG file to the default functions. */
1623 PNG_EXPORT(74, void, png_init_io, (png_structrp png_ptr, png_FILE_p fp));
1624 #endif
1625
1626 /* Replace the (error and abort), and warning functions with user
1627 * supplied functions. If no messages are to be printed you must still
1628 * write and use replacement functions. The replacement error_fn should
1629 * still do a longjmp to the last setjmp location if you are using this
1630 * method of error handling. If error_fn or warning_fn is NULL, the
1631 * default function will be used.
1632 */
1633
1634 PNG_EXPORT(75, void, png_set_error_fn, (png_structrp png_ptr,
1635 png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn));
1636
1637 /* Return the user pointer associated with the error functions */
1638 PNG_EXPORT(76, png_voidp, png_get_error_ptr, (png_const_structrp png_ptr));
1639
1640 /* Replace the default data output functions with a user supplied one(s).
1641 * If buffered output is not used, then output_flush_fn can be set to NULL.
1642 * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time
1643 * output_flush_fn will be ignored (and thus can be NULL).
1644 * It is probably a mistake to use NULL for output_flush_fn if
1645 * write_data_fn is not also NULL unless you have built libpng with
1646 * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's
1647 * default flush function, which uses the standard *FILE structure, will
1648 * be used.
1649 */
1650 PNG_EXPORT(77, void, png_set_write_fn, (png_structrp png_ptr, png_voidp io_ptr,
1651 png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn));
1652
1653 /* Replace the default data input function with a user supplied one. */
1654 PNG_EXPORT(78, void, png_set_read_fn, (png_structrp png_ptr, png_voidp io_ptr,
1655 png_rw_ptr read_data_fn));
1656
1657 /* Return the user pointer associated with the I/O functions */
1658 PNG_EXPORT(79, png_voidp, png_get_io_ptr, (png_const_structrp png_ptr));
1659
1660 PNG_EXPORT(80, void, png_set_read_status_fn, (png_structrp png_ptr,
1661 png_read_status_ptr read_row_fn));
1662
1663 PNG_EXPORT(81, void, png_set_write_status_fn, (png_structrp png_ptr,
1664 png_write_status_ptr write_row_fn));
1665
1666 #ifdef PNG_USER_MEM_SUPPORTED
1667 /* Replace the default memory allocation functions with user supplied one(s). */
1668 PNG_EXPORT(82, void, png_set_mem_fn, (png_structrp png_ptr, png_voidp mem_ptr,
1669 png_malloc_ptr malloc_fn, png_free_ptr free_fn));
1670 /* Return the user pointer associated with the memory functions */
1671 PNG_EXPORT(83, png_voidp, png_get_mem_ptr, (png_const_structrp png_ptr));
1672 #endif
1673
1674 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
1675 PNG_EXPORT(84, void, png_set_read_user_transform_fn, (png_structrp png_ptr,
1676 png_user_transform_ptr read_user_transform_fn));
1677 #endif
1678
1679 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
1680 PNG_EXPORT(85, void, png_set_write_user_transform_fn, (png_structrp png_ptr,
1681 png_user_transform_ptr write_user_transform_fn));
1682 #endif
1683
1684 #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
1685 PNG_EXPORT(86, void, png_set_user_transform_info, (png_structrp png_ptr,
1686 png_voidp user_transform_ptr, int user_transform_depth,
1687 int user_transform_channels));
1688 /* Return the user pointer associated with the user transform functions */
1689 PNG_EXPORT(87, png_voidp, png_get_user_transform_ptr,
1690 (png_const_structrp png_ptr));
1691 #endif
1692
1693 #ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED
1694 /* Return information about the row currently being processed. Note that these
1695 * APIs do not fail but will return unexpected results if called outside a user
1696 * transform callback. Also note that when transforming an interlaced image the
1697 * row number is the row number within the sub-image of the interlace pass, so
1698 * the value will increase to the height of the sub-image (not the full image)
1699 * then reset to 0 for the next pass.
1700 *
1701 * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
1702 * find the output pixel (x,y) given an interlaced sub-image pixel
1703 * (row,col,pass). (See below for these macros.)
1704 */
1705 PNG_EXPORT(217, png_uint_32, png_get_current_row_number, (png_const_structrp));
1706 PNG_EXPORT(218, png_byte, png_get_current_pass_number, (png_const_structrp));
1707 #endif
1708
1709 #ifdef PNG_READ_USER_CHUNKS_SUPPORTED
1710 /* This callback is called only for *unknown* chunks. If
1711 * PNG_HANDLE_AS_UNKNOWN_SUPPORTED is set then it is possible to set known
1712 * chunks to be treated as unknown, however in this case the callback must do
1713 * any processing required by the chunk (e.g. by calling the appropriate
1714 * png_set_ APIs.)
1715 *
1716 * There is no write support - on write, by default, all the chunks in the
1717 * 'unknown' list are written in the specified position.
1718 *
1719 * The integer return from the callback function is interpreted thus:
1720 *
1721 * negative: An error occurred; png_chunk_error will be called.
1722 * zero: The chunk was not handled, the chunk will be saved. A critical
1723 * chunk will cause an error at this point unless it is to be saved.
1724 * positive: The chunk was handled, libpng will ignore/discard it.
1725 *
1726 * See "INTERACTION WTIH USER CHUNK CALLBACKS" below for important notes about
1727 * how this behavior will change in libpng 1.7
1728 */
1729 PNG_EXPORT(88, void, png_set_read_user_chunk_fn, (png_structrp png_ptr,
1730 png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));
1731 #endif
1732
1733 #ifdef PNG_USER_CHUNKS_SUPPORTED
1734 PNG_EXPORT(89, png_voidp, png_get_user_chunk_ptr, (png_const_structrp png_ptr));
1735 #endif
1736
1737 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1738 /* Sets the function callbacks for the push reader, and a pointer to a
1739 * user-defined structure available to the callback functions.
1740 */
1741 PNG_EXPORT(90, void, png_set_progressive_read_fn, (png_structrp png_ptr,
1742 png_voidp progressive_ptr, png_progressive_info_ptr info_fn,
1743 png_progressive_row_ptr row_fn, png_progressive_end_ptr end_fn));
1744
1745 /* Returns the user pointer associated with the push read functions */
1746 PNG_EXPORT(91, png_voidp, png_get_progressive_ptr,
1747 (png_const_structrp png_ptr));
1748
1749 /* Function to be called when data becomes available */
1750 PNG_EXPORT(92, void, png_process_data, (png_structrp png_ptr,
1751 png_inforp info_ptr, png_bytep buffer, png_size_t buffer_size));
1752
1753 /* A function which may be called *only* within png_process_data to stop the
1754 * processing of any more data. The function returns the number of bytes
1755 * remaining, excluding any that libpng has cached internally. A subsequent
1756 * call to png_process_data must supply these bytes again. If the argument
1757 * 'save' is set to true the routine will first save all the pending data and
1758 * will always return 0.
1759 */
1760 PNG_EXPORT(219, png_size_t, png_process_data_pause, (png_structrp, int save));
1761
1762 /* A function which may be called *only* outside (after) a call to
1763 * png_process_data. It returns the number of bytes of data to skip in the
1764 * input. Normally it will return 0, but if it returns a non-zero value the
1765 * application must skip than number of bytes of input data and pass the
1766 * following data to the next call to png_process_data.
1767 */
1768 PNG_EXPORT(220, png_uint_32, png_process_data_skip, (png_structrp));
1769
1770 /* Function that combines rows. 'new_row' is a flag that should come from
1771 * the callback and be non-NULL if anything needs to be done; the library
1772 * stores its own version of the new data internally and ignores the passed
1773 * in value.
1774 */
1775 PNG_EXPORT(93, void, png_progressive_combine_row, (png_const_structrp png_ptr,
1776 png_bytep old_row, png_const_bytep new_row));
1777 #endif /* PROGRESSIVE_READ */
1778
1779 PNG_EXPORTA(94, png_voidp, png_malloc, (png_const_structrp png_ptr,
1780 png_alloc_size_t size), PNG_ALLOCATED);
1781 /* Added at libpng version 1.4.0 */
1782 PNG_EXPORTA(95, png_voidp, png_calloc, (png_const_structrp png_ptr,
1783 png_alloc_size_t size), PNG_ALLOCATED);
1784
1785 /* Added at libpng version 1.2.4 */
1786 PNG_EXPORTA(96, png_voidp, png_malloc_warn, (png_const_structrp png_ptr,
1787 png_alloc_size_t size), PNG_ALLOCATED);
1788
1789 /* Frees a pointer allocated by png_malloc() */
1790 PNG_EXPORT(97, void, png_free, (png_const_structrp png_ptr, png_voidp ptr));
1791
1792 /* Free data that was allocated internally */
1793 PNG_EXPORT(98, void, png_free_data, (png_const_structrp png_ptr,
1794 png_inforp info_ptr, png_uint_32 free_me, int num));
1795
1796 /* Reassign responsibility for freeing existing data, whether allocated
1797 * by libpng or by the application; this works on the png_info structure passed
1798 * in, it does not change the state for other png_info structures.
1799 *
1800 * It is unlikely that this function works correctly as of 1.6.0 and using it
1801 * may result either in memory leaks or double free of allocated data.
1802 */
1803 PNG_EXPORT(99, void, png_data_freer, (png_const_structrp png_ptr,
1804 png_inforp info_ptr, int freer, png_uint_32 mask));
1805
1806 /* Assignments for png_data_freer */
1807 #define PNG_DESTROY_WILL_FREE_DATA 1
1808 #define PNG_SET_WILL_FREE_DATA 1
1809 #define PNG_USER_WILL_FREE_DATA 2
1810 /* Flags for png_ptr->free_me and info_ptr->free_me */
1811 #define PNG_FREE_HIST 0x0008U
1812 #define PNG_FREE_ICCP 0x0010U
1813 #define PNG_FREE_SPLT 0x0020U
1814 #define PNG_FREE_ROWS 0x0040U
1815 #define PNG_FREE_PCAL 0x0080U
1816 #define PNG_FREE_SCAL 0x0100U
1817 #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
1818 # define PNG_FREE_UNKN 0x0200U
1819 #endif
1820 /* PNG_FREE_LIST 0x0400U removed in 1.6.0 because it is ignored */
1821 #define PNG_FREE_PLTE 0x1000U
1822 #define PNG_FREE_TRNS 0x2000U
1823 #define PNG_FREE_TEXT 0x4000U
1824 #define PNG_FREE_ALL 0x7fffU
1825 #define PNG_FREE_MUL 0x4220U /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */
1826
1827 #ifdef PNG_USER_MEM_SUPPORTED
1828 PNG_EXPORTA(100, png_voidp, png_malloc_default, (png_const_structrp png_ptr,
1829 png_alloc_size_t size), PNG_ALLOCATED PNG_DEPRECATED);
1830 PNG_EXPORTA(101, void, png_free_default, (png_const_structrp png_ptr,
1831 png_voidp ptr), PNG_DEPRECATED);
1832 #endif
1833
1834 #ifdef PNG_ERROR_TEXT_SUPPORTED
1835 /* Fatal error in PNG image of libpng - can't continue */
1836 PNG_EXPORTA(102, void, png_error, (png_const_structrp png_ptr,
1837 png_const_charp error_message), PNG_NORETURN);
1838
1839 /* The same, but the chunk name is prepended to the error string. */
1840 PNG_EXPORTA(103, void, png_chunk_error, (png_const_structrp png_ptr,
1841 png_const_charp error_message), PNG_NORETURN);
1842
1843 #else
1844 /* Fatal error in PNG image of libpng - can't continue */
1845 PNG_EXPORTA(104, void, png_err, (png_const_structrp png_ptr), PNG_NORETURN);
1846 # define png_error(s1,s2) png_err(s1)
1847 # define png_chunk_error(s1,s2) png_err(s1)
1848 #endif
1849
1850 #ifdef PNG_WARNINGS_SUPPORTED
1851 /* Non-fatal error in libpng. Can continue, but may have a problem. */
1852 PNG_EXPORT(105, void, png_warning, (png_const_structrp png_ptr,
1853 png_const_charp warning_message));
1854
1855 /* Non-fatal error in libpng, chunk name is prepended to message. */
1856 PNG_EXPORT(106, void, png_chunk_warning, (png_const_structrp png_ptr,
1857 png_const_charp warning_message));
1858 #else
1859 # define png_warning(s1,s2) ((void)(s1))
1860 # define png_chunk_warning(s1,s2) ((void)(s1))
1861 #endif
1862
1863 #ifdef PNG_BENIGN_ERRORS_SUPPORTED
1864 /* Benign error in libpng. Can continue, but may have a problem.
1865 * User can choose whether to handle as a fatal error or as a warning. */
1866 PNG_EXPORT(107, void, png_benign_error, (png_const_structrp png_ptr,
1867 png_const_charp warning_message));
1868
1869 #ifdef PNG_READ_SUPPORTED
1870 /* Same, chunk name is prepended to message (only during read) */
1871 PNG_EXPORT(108, void, png_chunk_benign_error, (png_const_structrp png_ptr,
1872 png_const_charp warning_message));
1873 #endif
1874
1875 PNG_EXPORT(109, void, png_set_benign_errors,
1876 (png_structrp png_ptr, int allowed));
1877 #else
1878 # ifdef PNG_ALLOW_BENIGN_ERRORS
1879 # define png_benign_error png_warning
1880 # define png_chunk_benign_error png_chunk_warning
1881 # else
1882 # define png_benign_error png_error
1883 # define png_chunk_benign_error png_chunk_error
1884 # endif
1885 #endif
1886
1887 /* The png_set_<chunk> functions are for storing values in the png_info_struct.
1888 * Similarly, the png_get_<chunk> calls are used to read values from the
1889 * png_info_struct, either storing the parameters in the passed variables, or
1890 * setting pointers into the png_info_struct where the data is stored. The
1891 * png_get_<chunk> functions return a non-zero value if the data was available
1892 * in info_ptr, or return zero and do not change any of the parameters if the
1893 * data was not available.
1894 *
1895 * These functions should be used instead of directly accessing png_info
1896 * to avoid problems with future changes in the size and internal layout of
1897 * png_info_struct.
1898 */
1899 /* Returns "flag" if chunk data is valid in info_ptr. */
1900 PNG_EXPORT(110, png_uint_32, png_get_valid, (png_const_structrp png_ptr,
1901 png_const_inforp info_ptr, png_uint_32 flag));
1902
1903 /* Returns number of bytes needed to hold a transformed row. */
1904 PNG_EXPORT(111, png_size_t, png_get_rowbytes, (png_const_structrp png_ptr,
1905 png_const_inforp info_ptr));
1906
1907 #ifdef PNG_INFO_IMAGE_SUPPORTED
1908 /* Returns row_pointers, which is an array of pointers to scanlines that was
1909 * returned from png_read_png().
1910 */
1911 PNG_EXPORT(112, png_bytepp, png_get_rows, (png_const_structrp png_ptr,
1912 png_const_inforp info_ptr));
1913
1914 /* Set row_pointers, which is an array of pointers to scanlines for use
1915 * by png_write_png().
1916 */
1917 PNG_EXPORT(113, void, png_set_rows, (png_const_structrp png_ptr,
1918 png_inforp info_ptr, png_bytepp row_pointers));
1919 #endif
1920
1921 /* Returns number of color channels in image. */
1922 PNG_EXPORT(114, png_byte, png_get_channels, (png_const_structrp png_ptr,
1923 png_const_inforp info_ptr));
1924
1925 #ifdef PNG_EASY_ACCESS_SUPPORTED
1926 /* Returns image width in pixels. */
1927 PNG_EXPORT(115, png_uint_32, png_get_image_width, (png_const_structrp png_ptr,
1928 png_const_inforp info_ptr));
1929
1930 /* Returns image height in pixels. */
1931 PNG_EXPORT(116, png_uint_32, png_get_image_height, (png_const_structrp png_ptr,
1932 png_const_inforp info_ptr));
1933
1934 /* Returns image bit_depth. */
1935 PNG_EXPORT(117, png_byte, png_get_bit_depth, (png_const_structrp png_ptr,
1936 png_const_inforp info_ptr));
1937
1938 /* Returns image color_type. */
1939 PNG_EXPORT(118, png_byte, png_get_color_type, (png_const_structrp png_ptr,
1940 png_const_inforp info_ptr));
1941
1942 /* Returns image filter_type. */
1943 PNG_EXPORT(119, png_byte, png_get_filter_type, (png_const_structrp png_ptr,
1944 png_const_inforp info_ptr));
1945
1946 /* Returns image interlace_type. */
1947 PNG_EXPORT(120, png_byte, png_get_interlace_type, (png_const_structrp png_ptr,
1948 png_const_inforp info_ptr));
1949
1950 /* Returns image compression_type. */
1951 PNG_EXPORT(121, png_byte, png_get_compression_type, (png_const_structrp png_ptr,
1952 png_const_inforp info_ptr));
1953
1954 /* Returns image resolution in pixels per meter, from pHYs chunk data. */
1955 PNG_EXPORT(122, png_uint_32, png_get_pixels_per_meter,
1956 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1957 PNG_EXPORT(123, png_uint_32, png_get_x_pixels_per_meter,
1958 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1959 PNG_EXPORT(124, png_uint_32, png_get_y_pixels_per_meter,
1960 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1961
1962 /* Returns pixel aspect ratio, computed from pHYs chunk data. */
1963 PNG_FP_EXPORT(125, float, png_get_pixel_aspect_ratio,
1964 (png_const_structrp png_ptr, png_const_inforp info_ptr))
1965 PNG_FIXED_EXPORT(210, png_fixed_point, png_get_pixel_aspect_ratio_fixed,
1966 (png_const_structrp png_ptr, png_const_inforp info_ptr))
1967
1968 /* Returns image x, y offset in pixels or microns, from oFFs chunk data. */
1969 PNG_EXPORT(126, png_int_32, png_get_x_offset_pixels,
1970 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1971 PNG_EXPORT(127, png_int_32, png_get_y_offset_pixels,
1972 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1973 PNG_EXPORT(128, png_int_32, png_get_x_offset_microns,
1974 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1975 PNG_EXPORT(129, png_int_32, png_get_y_offset_microns,
1976 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1977
1978 #endif /* EASY_ACCESS */
1979
1980 #ifdef PNG_READ_SUPPORTED
1981 /* Returns pointer to signature string read from PNG header */
1982 PNG_EXPORT(130, png_const_bytep, png_get_signature, (png_const_structrp png_ptr,
1983 png_const_inforp info_ptr));
1984 #endif
1985
1986 #ifdef PNG_bKGD_SUPPORTED
1987 PNG_EXPORT(131, png_uint_32, png_get_bKGD, (png_const_structrp png_ptr,
1988 png_inforp info_ptr, png_color_16p *background));
1989 #endif
1990
1991 #ifdef PNG_bKGD_SUPPORTED
1992 PNG_EXPORT(132, void, png_set_bKGD, (png_const_structrp png_ptr,
1993 png_inforp info_ptr, png_const_color_16p background));
1994 #endif
1995
1996 #ifdef PNG_cHRM_SUPPORTED
1997 PNG_FP_EXPORT(133, png_uint_32, png_get_cHRM, (png_const_structrp png_ptr,
1998 png_const_inforp info_ptr, double *white_x, double *white_y, double *red_x,
1999 double *red_y, double *green_x, double *green_y, double *blue_x,
2000 double *blue_y))
2001 PNG_FP_EXPORT(230, png_uint_32, png_get_cHRM_XYZ, (png_const_structrp png_ptr,
2002 png_const_inforp info_ptr, double *red_X, double *red_Y, double *red_Z,
2003 double *green_X, double *green_Y, double *green_Z, double *blue_X,
2004 double *blue_Y, double *blue_Z))
2005 PNG_FIXED_EXPORT(134, png_uint_32, png_get_cHRM_fixed,
2006 (png_const_structrp png_ptr, png_const_inforp info_ptr,
2007 png_fixed_point *int_white_x, png_fixed_point *int_white_y,
2008 png_fixed_point *int_red_x, png_fixed_point *int_red_y,
2009 png_fixed_point *int_green_x, png_fixed_point *int_green_y,
2010 png_fixed_point *int_blue_x, png_fixed_point *int_blue_y))
2011 PNG_FIXED_EXPORT(231, png_uint_32, png_get_cHRM_XYZ_fixed,
2012 (png_const_structrp png_ptr, png_const_inforp info_ptr,
2013 png_fixed_point *int_red_X, png_fixed_point *int_red_Y,
2014 png_fixed_point *int_red_Z, png_fixed_point *int_green_X,
2015 png_fixed_point *int_green_Y, png_fixed_point *int_green_Z,
2016 png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y,
2017 png_fixed_point *int_blue_Z))
2018 #endif
2019
2020 #ifdef PNG_cHRM_SUPPORTED
2021 PNG_FP_EXPORT(135, void, png_set_cHRM, (png_const_structrp png_ptr,
2022 png_inforp info_ptr,
2023 double white_x, double white_y, double red_x, double red_y, double green_x,
2024 double green_y, double blue_x, double blue_y))
2025 PNG_FP_EXPORT(232, void, png_set_cHRM_XYZ, (png_const_structrp png_ptr,
2026 png_inforp info_ptr, double red_X, double red_Y, double red_Z,
2027 double green_X, double green_Y, double green_Z, double blue_X,
2028 double blue_Y, double blue_Z))
2029 PNG_FIXED_EXPORT(136, void, png_set_cHRM_fixed, (png_const_structrp png_ptr,
2030 png_inforp info_ptr, png_fixed_point int_white_x,
2031 png_fixed_point int_white_y, png_fixed_point int_red_x,
2032 png_fixed_point int_red_y, png_fixed_point int_green_x,
2033 png_fixed_point int_green_y, png_fixed_point int_blue_x,
2034 png_fixed_point int_blue_y))
2035 PNG_FIXED_EXPORT(233, void, png_set_cHRM_XYZ_fixed, (png_const_structrp png_ptr,
2036 png_inforp info_ptr, png_fixed_point int_red_X, png_fixed_point int_red_Y,
2037 png_fixed_point int_red_Z, png_fixed_point int_green_X,
2038 png_fixed_point int_green_Y, png_fixed_point int_green_Z,
2039 png_fixed_point int_blue_X, png_fixed_point int_blue_Y,
2040 png_fixed_point int_blue_Z))
2041 #endif
2042
2043 #ifdef PNG_gAMA_SUPPORTED
2044 PNG_FP_EXPORT(137, png_uint_32, png_get_gAMA, (png_const_structrp png_ptr,
2045 png_const_inforp info_ptr, double *file_gamma))
2046 PNG_FIXED_EXPORT(138, png_uint_32, png_get_gAMA_fixed,
2047 (png_const_structrp png_ptr, png_const_inforp info_ptr,
2048 png_fixed_point *int_file_gamma))
2049 #endif
2050
2051 #ifdef PNG_gAMA_SUPPORTED
2052 PNG_FP_EXPORT(139, void, png_set_gAMA, (png_const_structrp png_ptr,
2053 png_inforp info_ptr, double file_gamma))
2054 PNG_FIXED_EXPORT(140, void, png_set_gAMA_fixed, (png_const_structrp png_ptr,
2055 png_inforp info_ptr, png_fixed_point int_file_gamma))
2056 #endif
2057
2058 #ifdef PNG_hIST_SUPPORTED
2059 PNG_EXPORT(141, png_uint_32, png_get_hIST, (png_const_structrp png_ptr,
2060 png_inforp info_ptr, png_uint_16p *hist));
2061 #endif
2062
2063 #ifdef PNG_hIST_SUPPORTED
2064 PNG_EXPORT(142, void, png_set_hIST, (png_const_structrp png_ptr,
2065 png_inforp info_ptr, png_const_uint_16p hist));
2066 #endif
2067
2068 PNG_EXPORT(143, png_uint_32, png_get_IHDR, (png_const_structrp png_ptr,
2069 png_const_inforp info_ptr, png_uint_32 *width, png_uint_32 *height,
2070 int *bit_depth, int *color_type, int *interlace_method,
2071 int *compression_method, int *filter_method));
2072
2073 PNG_EXPORT(144, void, png_set_IHDR, (png_const_structrp png_ptr,
2074 png_inforp info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth,
2075 int color_type, int interlace_method, int compression_method,
2076 int filter_method));
2077
2078 #ifdef PNG_oFFs_SUPPORTED
2079 PNG_EXPORT(145, png_uint_32, png_get_oFFs, (png_const_structrp png_ptr,
2080 png_const_inforp info_ptr, png_int_32 *offset_x, png_int_32 *offset_y,
2081 int *unit_type));
2082 #endif
2083
2084 #ifdef PNG_oFFs_SUPPORTED
2085 PNG_EXPORT(146, void, png_set_oFFs, (png_const_structrp png_ptr,
2086 png_inforp info_ptr, png_int_32 offset_x, png_int_32 offset_y,
2087 int unit_type));
2088 #endif
2089
2090 #ifdef PNG_pCAL_SUPPORTED
2091 PNG_EXPORT(147, png_uint_32, png_get_pCAL, (png_const_structrp png_ptr,
2092 png_inforp info_ptr, png_charp *purpose, png_int_32 *X0,
2093 png_int_32 *X1, int *type, int *nparams, png_charp *units,
2094 png_charpp *params));
2095 #endif
2096
2097 #ifdef PNG_pCAL_SUPPORTED
2098 PNG_EXPORT(148, void, png_set_pCAL, (png_const_structrp png_ptr,
2099 png_inforp info_ptr, png_const_charp purpose, png_int_32 X0, png_int_32 X1,
2100 int type, int nparams, png_const_charp units, png_charpp params));
2101 #endif
2102
2103 #ifdef PNG_pHYs_SUPPORTED
2104 PNG_EXPORT(149, png_uint_32, png_get_pHYs, (png_const_structrp png_ptr,
2105 png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y,
2106 int *unit_type));
2107 #endif
2108
2109 #ifdef PNG_pHYs_SUPPORTED
2110 PNG_EXPORT(150, void, png_set_pHYs, (png_const_structrp png_ptr,
2111 png_inforp info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type));
2112 #endif
2113
2114 PNG_EXPORT(151, png_uint_32, png_get_PLTE, (png_const_structrp png_ptr,
2115 png_inforp info_ptr, png_colorp *palette, int *num_palette));
2116
2117 PNG_EXPORT(152, void, png_set_PLTE, (png_structrp png_ptr,
2118 png_inforp info_ptr, png_const_colorp palette, int num_palette));
2119
2120 #ifdef PNG_sBIT_SUPPORTED
2121 PNG_EXPORT(153, png_uint_32, png_get_sBIT, (png_const_structrp png_ptr,
2122 png_inforp info_ptr, png_color_8p *sig_bit));
2123 #endif
2124
2125 #ifdef PNG_sBIT_SUPPORTED
2126 PNG_EXPORT(154, void, png_set_sBIT, (png_const_structrp png_ptr,
2127 png_inforp info_ptr, png_const_color_8p sig_bit));
2128 #endif
2129
2130 #ifdef PNG_sRGB_SUPPORTED
2131 PNG_EXPORT(155, png_uint_32, png_get_sRGB, (png_const_structrp png_ptr,
2132 png_const_inforp info_ptr, int *file_srgb_intent));
2133 #endif
2134
2135 #ifdef PNG_sRGB_SUPPORTED
2136 PNG_EXPORT(156, void, png_set_sRGB, (png_const_structrp png_ptr,
2137 png_inforp info_ptr, int srgb_intent));
2138 PNG_EXPORT(157, void, png_set_sRGB_gAMA_and_cHRM, (png_const_structrp png_ptr,
2139 png_inforp info_ptr, int srgb_intent));
2140 #endif
2141
2142 #ifdef PNG_iCCP_SUPPORTED
2143 PNG_EXPORT(158, png_uint_32, png_get_iCCP, (png_const_structrp png_ptr,
2144 png_inforp info_ptr, png_charpp name, int *compression_type,
2145 png_bytepp profile, png_uint_32 *proflen));
2146 #endif
2147
2148 #ifdef PNG_iCCP_SUPPORTED
2149 PNG_EXPORT(159, void, png_set_iCCP, (png_const_structrp png_ptr,
2150 png_inforp info_ptr, png_const_charp name, int compression_type,
2151 png_const_bytep profile, png_uint_32 proflen));
2152 #endif
2153
2154 #ifdef PNG_sPLT_SUPPORTED
2155 PNG_EXPORT(160, int, png_get_sPLT, (png_const_structrp png_ptr,
2156 png_inforp info_ptr, png_sPLT_tpp entries));
2157 #endif
2158
2159 #ifdef PNG_sPLT_SUPPORTED
2160 PNG_EXPORT(161, void, png_set_sPLT, (png_const_structrp png_ptr,
2161 png_inforp info_ptr, png_const_sPLT_tp entries, int nentries));
2162 #endif
2163
2164 #ifdef PNG_TEXT_SUPPORTED
2165 /* png_get_text also returns the number of text chunks in *num_text */
2166 PNG_EXPORT(162, int, png_get_text, (png_const_structrp png_ptr,
2167 png_inforp info_ptr, png_textp *text_ptr, int *num_text));
2168 #endif
2169
2170 /* Note while png_set_text() will accept a structure whose text,
2171 * language, and translated keywords are NULL pointers, the structure
2172 * returned by png_get_text will always contain regular
2173 * zero-terminated C strings. They might be empty strings but
2174 * they will never be NULL pointers.
2175 */
2176
2177 #ifdef PNG_TEXT_SUPPORTED
2178 PNG_EXPORT(163, void, png_set_text, (png_const_structrp png_ptr,
2179 png_inforp info_ptr, png_const_textp text_ptr, int num_text));
2180 #endif
2181
2182 #ifdef PNG_tIME_SUPPORTED
2183 PNG_EXPORT(164, png_uint_32, png_get_tIME, (png_const_structrp png_ptr,
2184 png_inforp info_ptr, png_timep *mod_time));
2185 #endif
2186
2187 #ifdef PNG_tIME_SUPPORTED
2188 PNG_EXPORT(165, void, png_set_tIME, (png_const_structrp png_ptr,
2189 png_inforp info_ptr, png_const_timep mod_time));
2190 #endif
2191
2192 #ifdef PNG_tRNS_SUPPORTED
2193 PNG_EXPORT(166, png_uint_32, png_get_tRNS, (png_const_structrp png_ptr,
2194 png_inforp info_ptr, png_bytep *trans_alpha, int *num_trans,
2195 png_color_16p *trans_color));
2196 #endif
2197
2198 #ifdef PNG_tRNS_SUPPORTED
2199 PNG_EXPORT(167, void, png_set_tRNS, (png_structrp png_ptr,
2200 png_inforp info_ptr, png_const_bytep trans_alpha, int num_trans,
2201 png_const_color_16p trans_color));
2202 #endif
2203
2204 #ifdef PNG_sCAL_SUPPORTED
2205 PNG_FP_EXPORT(168, png_uint_32, png_get_sCAL, (png_const_structrp png_ptr,
2206 png_const_inforp info_ptr, int *unit, double *width, double *height))
2207 #if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || \
2208 defined(PNG_FLOATING_POINT_SUPPORTED)
2209 /* NOTE: this API is currently implemented using floating point arithmetic,
2210 * consequently it can only be used on systems with floating point support.
2211 * In any case the range of values supported by png_fixed_point is small and it
2212 * is highly recommended that png_get_sCAL_s be used instead.
2213 */
2214 PNG_FIXED_EXPORT(214, png_uint_32, png_get_sCAL_fixed,
2215 (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit,
2216 png_fixed_point *width, png_fixed_point *height))
2217 #endif
2218 PNG_EXPORT(169, png_uint_32, png_get_sCAL_s,
2219 (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit,
2220 png_charpp swidth, png_charpp sheight));
2221
2222 PNG_FP_EXPORT(170, void, png_set_sCAL, (png_const_structrp png_ptr,
2223 png_inforp info_ptr, int unit, double width, double height))
2224 PNG_FIXED_EXPORT(213, void, png_set_sCAL_fixed, (png_const_structrp png_ptr,
2225 png_inforp info_ptr, int unit, png_fixed_point width,
2226 png_fixed_point height))
2227 PNG_EXPORT(171, void, png_set_sCAL_s, (png_const_structrp png_ptr,
2228 png_inforp info_ptr, int unit,
2229 png_const_charp swidth, png_const_charp sheight));
2230 #endif /* sCAL */
2231
2232 #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
2233 /* Provide the default handling for all unknown chunks or, optionally, for
2234 * specific unknown chunks.
2235 *
2236 * NOTE: prior to 1.6.0 the handling specified for particular chunks on read was
2237 * ignored and the default was used, the per-chunk setting only had an effect on
2238 * write. If you wish to have chunk-specific handling on read in code that must
2239 * work on earlier versions you must use a user chunk callback to specify the
2240 * desired handling (keep or discard.)
2241 *
2242 * The 'keep' parameter is a PNG_HANDLE_CHUNK_ value as listed below. The
2243 * parameter is interpreted as follows:
2244 *
2245 * READ:
2246 * PNG_HANDLE_CHUNK_AS_DEFAULT:
2247 * Known chunks: do normal libpng processing, do not keep the chunk (but
2248 * see the comments below about PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
2249 * Unknown chunks: for a specific chunk use the global default, when used
2250 * as the default discard the chunk data.
2251 * PNG_HANDLE_CHUNK_NEVER:
2252 * Discard the chunk data.
2253 * PNG_HANDLE_CHUNK_IF_SAFE:
2254 * Keep the chunk data if the chunk is not critical else raise a chunk
2255 * error.
2256 * PNG_HANDLE_CHUNK_ALWAYS:
2257 * Keep the chunk data.
2258 *
2259 * If the chunk data is saved it can be retrieved using png_get_unknown_chunks,
2260 * below. Notice that specifying "AS_DEFAULT" as a global default is equivalent
2261 * to specifying "NEVER", however when "AS_DEFAULT" is used for specific chunks
2262 * it simply resets the behavior to the libpng default.
2263 *
2264 * INTERACTION WTIH USER CHUNK CALLBACKS:
2265 * The per-chunk handling is always used when there is a png_user_chunk_ptr
2266 * callback and the callback returns 0; the chunk is then always stored *unless*
2267 * it is critical and the per-chunk setting is other than ALWAYS. Notice that
2268 * the global default is *not* used in this case. (In effect the per-chunk
2269 * value is incremented to at least IF_SAFE.)
2270 *
2271 * IMPORTANT NOTE: this behavior will change in libpng 1.7 - the global and
2272 * per-chunk defaults will be honored. If you want to preserve the current
2273 * behavior when your callback returns 0 you must set PNG_HANDLE_CHUNK_IF_SAFE
2274 * as the default - if you don't do this libpng 1.6 will issue a warning.
2275 *
2276 * If you want unhandled unknown chunks to be discarded in libpng 1.6 and
2277 * earlier simply return '1' (handled).
2278 *
2279 * PNG_HANDLE_AS_UNKNOWN_SUPPORTED:
2280 * If this is *not* set known chunks will always be handled by libpng and
2281 * will never be stored in the unknown chunk list. Known chunks listed to
2282 * png_set_keep_unknown_chunks will have no effect. If it is set then known
2283 * chunks listed with a keep other than AS_DEFAULT will *never* be processed
2284 * by libpng, in addition critical chunks must either be processed by the
2285 * callback or saved.
2286 *
2287 * The IHDR and IEND chunks must not be listed. Because this turns off the
2288 * default handling for chunks that would otherwise be recognized the
2289 * behavior of libpng transformations may well become incorrect!
2290 *
2291 * WRITE:
2292 * When writing chunks the options only apply to the chunks specified by
2293 * png_set_unknown_chunks (below), libpng will *always* write known chunks
2294 * required by png_set_ calls and will always write the core critical chunks
2295 * (as required for PLTE).
2296 *
2297 * Each chunk in the png_set_unknown_chunks list is looked up in the
2298 * png_set_keep_unknown_chunks list to find the keep setting, this is then
2299 * interpreted as follows:
2300 *
2301 * PNG_HANDLE_CHUNK_AS_DEFAULT:
2302 * Write safe-to-copy chunks and write other chunks if the global
2303 * default is set to _ALWAYS, otherwise don't write this chunk.
2304 * PNG_HANDLE_CHUNK_NEVER:
2305 * Do not write the chunk.
2306 * PNG_HANDLE_CHUNK_IF_SAFE:
2307 * Write the chunk if it is safe-to-copy, otherwise do not write it.
2308 * PNG_HANDLE_CHUNK_ALWAYS:
2309 * Write the chunk.
2310 *
2311 * Note that the default behavior is effectively the opposite of the read case -
2312 * in read unknown chunks are not stored by default, in write they are written
2313 * by default. Also the behavior of PNG_HANDLE_CHUNK_IF_SAFE is very different
2314 * - on write the safe-to-copy bit is checked, on read the critical bit is
2315 * checked and on read if the chunk is critical an error will be raised.
2316 *
2317 * num_chunks:
2318 * ===========
2319 * If num_chunks is positive, then the "keep" parameter specifies the manner
2320 * for handling only those chunks appearing in the chunk_list array,
2321 * otherwise the chunk list array is ignored.
2322 *
2323 * If num_chunks is 0 the "keep" parameter specifies the default behavior for
2324 * unknown chunks, as described above.
2325 *
2326 * If num_chunks is negative, then the "keep" parameter specifies the manner
2327 * for handling all unknown chunks plus all chunks recognized by libpng
2328 * except for the IHDR, PLTE, tRNS, IDAT, and IEND chunks (which continue to
2329 * be processed by libpng.
2330 */
2331 PNG_EXPORT(172, void, png_set_keep_unknown_chunks, (png_structrp png_ptr,
2332 int keep, png_const_bytep chunk_list, int num_chunks));
2333
2334 /* The "keep" PNG_HANDLE_CHUNK_ parameter for the specified chunk is returned;
2335 * the result is therefore true (non-zero) if special handling is required,
2336 * false for the default handling.
2337 */
2338 PNG_EXPORT(173, int, png_handle_as_unknown, (png_const_structrp png_ptr,
2339 png_const_bytep chunk_name));
2340 #endif
2341
2342 #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
2343 PNG_EXPORT(174, void, png_set_unknown_chunks, (png_const_structrp png_ptr,
2344 png_inforp info_ptr, png_const_unknown_chunkp unknowns,
2345 int num_unknowns));
2346 /* NOTE: prior to 1.6.0 this routine set the 'location' field of the added
2347 * unknowns to the location currently stored in the png_struct. This is
2348 * invariably the wrong value on write. To fix this call the following API
2349 * for each chunk in the list with the correct location. If you know your
2350 * code won't be compiled on earlier versions you can rely on
2351 * png_set_unknown_chunks(write-ptr, png_get_unknown_chunks(read-ptr)) doing
2352 * the correct thing.
2353 */
2354
2355 PNG_EXPORT(175, void, png_set_unknown_chunk_location,
2356 (png_const_structrp png_ptr, png_inforp info_ptr, int chunk, int location));
2357
2358 PNG_EXPORT(176, int, png_get_unknown_chunks, (png_const_structrp png_ptr,
2359 png_inforp info_ptr, png_unknown_chunkpp entries));
2360 #endif
2361
2362 /* Png_free_data() will turn off the "valid" flag for anything it frees.
2363 * If you need to turn it off for a chunk that your application has freed,
2364 * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK);
2365 */
2366 PNG_EXPORT(177, void, png_set_invalid, (png_const_structrp png_ptr,
2367 png_inforp info_ptr, int mask));
2368
2369 #ifdef PNG_INFO_IMAGE_SUPPORTED
2370 /* The "params" pointer is currently not used and is for future expansion. */
2371 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
2372 PNG_EXPORT(178, void, png_read_png, (png_structrp png_ptr, png_inforp info_ptr,
2373 int transforms, png_voidp params));
2374 #endif
2375 #ifdef PNG_WRITE_SUPPORTED
2376 PNG_EXPORT(179, void, png_write_png, (png_structrp png_ptr, png_inforp info_ptr,
2377 int transforms, png_voidp params));
2378 #endif
2379 #endif
2380
2381 PNG_EXPORT(180, png_const_charp, png_get_copyright,
2382 (png_const_structrp png_ptr));
2383 PNG_EXPORT(181, png_const_charp, png_get_header_ver,
2384 (png_const_structrp png_ptr));
2385 PNG_EXPORT(182, png_const_charp, png_get_header_version,
2386 (png_const_structrp png_ptr));
2387 PNG_EXPORT(183, png_const_charp, png_get_libpng_ver,
2388 (png_const_structrp png_ptr));
2389
2390 #ifdef PNG_MNG_FEATURES_SUPPORTED
2391 PNG_EXPORT(184, png_uint_32, png_permit_mng_features, (png_structrp png_ptr,
2392 png_uint_32 mng_features_permitted));
2393 #endif
2394
2395 /* For use in png_set_keep_unknown, added to version 1.2.6 */
2396 #define PNG_HANDLE_CHUNK_AS_DEFAULT 0
2397 #define PNG_HANDLE_CHUNK_NEVER 1
2398 #define PNG_HANDLE_CHUNK_IF_SAFE 2
2399 #define PNG_HANDLE_CHUNK_ALWAYS 3
2400 #define PNG_HANDLE_CHUNK_LAST 4
2401
2402 /* Strip the prepended error numbers ("#nnn ") from error and warning
2403 * messages before passing them to the error or warning handler.
2404 */
2405 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
2406 PNG_EXPORT(185, void, png_set_strip_error_numbers, (png_structrp png_ptr,
2407 png_uint_32 strip_mode));
2408 #endif
2409
2410 /* Added in libpng-1.2.6 */
2411 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
2412 PNG_EXPORT(186, void, png_set_user_limits, (png_structrp png_ptr,
2413 png_uint_32 user_width_max, png_uint_32 user_height_max));
2414 PNG_EXPORT(187, png_uint_32, png_get_user_width_max,
2415 (png_const_structrp png_ptr));
2416 PNG_EXPORT(188, png_uint_32, png_get_user_height_max,
2417 (png_const_structrp png_ptr));
2418 /* Added in libpng-1.4.0 */
2419 PNG_EXPORT(189, void, png_set_chunk_cache_max, (png_structrp png_ptr,
2420 png_uint_32 user_chunk_cache_max));
2421 PNG_EXPORT(190, png_uint_32, png_get_chunk_cache_max,
2422 (png_const_structrp png_ptr));
2423 /* Added in libpng-1.4.1 */
2424 PNG_EXPORT(191, void, png_set_chunk_malloc_max, (png_structrp png_ptr,
2425 png_alloc_size_t user_chunk_cache_max));
2426 PNG_EXPORT(192, png_alloc_size_t, png_get_chunk_malloc_max,
2427 (png_const_structrp png_ptr));
2428 #endif
2429
2430 #if defined(PNG_INCH_CONVERSIONS_SUPPORTED)
2431 PNG_EXPORT(193, png_uint_32, png_get_pixels_per_inch,
2432 (png_const_structrp png_ptr, png_const_inforp info_ptr));
2433
2434 PNG_EXPORT(194, png_uint_32, png_get_x_pixels_per_inch,
2435 (png_const_structrp png_ptr, png_const_inforp info_ptr));
2436
2437 PNG_EXPORT(195, png_uint_32, png_get_y_pixels_per_inch,
2438 (png_const_structrp png_ptr, png_const_inforp info_ptr));
2439
2440 PNG_FP_EXPORT(196, float, png_get_x_offset_inches,
2441 (png_const_structrp png_ptr, png_const_inforp info_ptr))
2442 #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */
2443 PNG_FIXED_EXPORT(211, png_fixed_point, png_get_x_offset_inches_fixed,
2444 (png_const_structrp png_ptr, png_const_inforp info_ptr))
2445 #endif
2446
2447 PNG_FP_EXPORT(197, float, png_get_y_offset_inches, (png_const_structrp png_ptr,
2448 png_const_inforp info_ptr))
2449 #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */
2450 PNG_FIXED_EXPORT(212, png_fixed_point, png_get_y_offset_inches_fixed,
2451 (png_const_structrp png_ptr, png_const_inforp info_ptr))
2452 #endif
2453
2454 # ifdef PNG_pHYs_SUPPORTED
2455 PNG_EXPORT(198, png_uint_32, png_get_pHYs_dpi, (png_const_structrp png_ptr,
2456 png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y,
2457 int *unit_type));
2458 # endif /* pHYs */
2459 #endif /* INCH_CONVERSIONS */
2460
2461 /* Added in libpng-1.4.0 */
2462 #ifdef PNG_IO_STATE_SUPPORTED
2463 PNG_EXPORT(199, png_uint_32, png_get_io_state, (png_const_structrp png_ptr));
2464
2465 /* Removed from libpng 1.6; use png_get_io_chunk_type. */
2466 PNG_REMOVED(200, png_const_bytep, png_get_io_chunk_name, (png_structrp png_ptr),
2467 PNG_DEPRECATED)
2468
2469 PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type,
2470 (png_const_structrp png_ptr));
2471
2472 /* The flags returned by png_get_io_state() are the following: */
2473 # define PNG_IO_NONE 0x0000 /* no I/O at this moment */
2474 # define PNG_IO_READING 0x0001 /* currently reading */
2475 # define PNG_IO_WRITING 0x0002 /* currently writing */
2476 # define PNG_IO_SIGNATURE 0x0010 /* currently at the file signature */
2477 # define PNG_IO_CHUNK_HDR 0x0020 /* currently at the chunk header */
2478 # define PNG_IO_CHUNK_DATA 0x0040 /* currently at the chunk data */
2479 # define PNG_IO_CHUNK_CRC 0x0080 /* currently at the chunk crc */
2480 # define PNG_IO_MASK_OP 0x000f /* current operation: reading/writing */
2481 # define PNG_IO_MASK_LOC 0x00f0 /* current location: sig/hdr/data/crc */
2482 #endif /* IO_STATE */
2483
2484 /* Interlace support. The following macros are always defined so that if
2485 * libpng interlace handling is turned off the macros may be used to handle
2486 * interlaced images within the application.
2487 */
2488 #define PNG_INTERLACE_ADAM7_PASSES 7
2489
2490 /* Two macros to return the first row and first column of the original,
2491 * full, image which appears in a given pass. 'pass' is in the range 0
2492 * to 6 and the result is in the range 0 to 7.
2493 */
2494 #define PNG_PASS_START_ROW(pass) (((1&~(pass))<<(3-((pass)>>1)))&7)
2495 #define PNG_PASS_START_COL(pass) (((1& (pass))<<(3-(((pass)+1)>>1)))&7)
2496
2497 /* A macro to return the offset between pixels in the output row for a pair of
2498 * pixels in the input - effectively the inverse of the 'COL_SHIFT' macro that
2499 * follows. Note that ROW_OFFSET is the offset from one row to the next whereas
2500 * COL_OFFSET is from one column to the next, within a row.
2501 */
2502 #define PNG_PASS_ROW_OFFSET(pass) ((pass)>2?(8>>(((pass)-1)>>1)):8)
2503 #define PNG_PASS_COL_OFFSET(pass) (1<<((7-(pass))>>1))
2504
2505 /* Two macros to help evaluate the number of rows or columns in each
2506 * pass. This is expressed as a shift - effectively log2 of the number or
2507 * rows or columns in each 8x8 tile of the original image.
2508 */
2509 #define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3)
2510 #define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3)
2511
2512 /* Hence two macros to determine the number of rows or columns in a given
2513 * pass of an image given its height or width. In fact these macros may
2514 * return non-zero even though the sub-image is empty, because the other
2515 * dimension may be empty for a small image.
2516 */
2517 #define PNG_PASS_ROWS(height, pass) (((height)+(((1<<PNG_PASS_ROW_SHIFT(pass))\
2518 -1)-PNG_PASS_START_ROW(pass)))>>PNG_PASS_ROW_SHIFT(pass))
2519 #define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\
2520 -1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass))
2521
2522 /* For the reader row callbacks (both progressive and sequential) it is
2523 * necessary to find the row in the output image given a row in an interlaced
2524 * image, so two more macros:
2525 */
2526 #define PNG_ROW_FROM_PASS_ROW(y_in, pass) \
2527 (((y_in)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass))
2528 #define PNG_COL_FROM_PASS_COL(x_in, pass) \
2529 (((x_in)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass))
2530
2531 /* Two macros which return a boolean (0 or 1) saying whether the given row
2532 * or column is in a particular pass. These use a common utility macro that
2533 * returns a mask for a given pass - the offset 'off' selects the row or
2534 * column version. The mask has the appropriate bit set for each column in
2535 * the tile.
2536 */
2537 #define PNG_PASS_MASK(pass,off) ( \
2538 ((0x110145AF>>(((7-(off))-(pass))<<2)) & 0xF) | \
2539 ((0x01145AF0>>(((7-(off))-(pass))<<2)) & 0xF0))
2540
2541 #define PNG_ROW_IN_INTERLACE_PASS(y, pass) \
2542 ((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1)
2543 #define PNG_COL_IN_INTERLACE_PASS(x, pass) \
2544 ((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1)
2545
2546 #ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
2547 /* With these routines we avoid an integer divide, which will be slower on
2548 * most machines. However, it does take more operations than the corresponding
2549 * divide method, so it may be slower on a few RISC systems. There are two
2550 * shifts (by 8 or 16 bits) and an addition, versus a single integer divide.
2551 *
2552 * Note that the rounding factors are NOT supposed to be the same! 128 and
2553 * 32768 are correct for the NODIV code; 127 and 32767 are correct for the
2554 * standard method.
2555 *
2556 * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
2557 */
2558
2559 /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */
2560
2561 # define png_composite(composite, fg, alpha, bg) \
2562 { png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \
2563 * (png_uint_16)(alpha) \
2564 + (png_uint_16)(bg)*(png_uint_16)(255 \
2565 - (png_uint_16)(alpha)) + 128); \
2566 (composite) = (png_byte)(((temp + (temp >> 8)) >> 8) & 0xff); }
2567
2568 # define png_composite_16(composite, fg, alpha, bg) \
2569 { png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) \
2570 * (png_uint_32)(alpha) \
2571 + (png_uint_32)(bg)*(65535 \
2572 - (png_uint_32)(alpha)) + 32768); \
2573 (composite) = (png_uint_16)(0xffff & ((temp + (temp >> 16)) >> 16)); }
2574
2575 #else /* Standard method using integer division */
2576
2577 # define png_composite(composite, fg, alpha, bg) \
2578 (composite) = \
2579 (png_byte)(0xff & (((png_uint_16)(fg) * (png_uint_16)(alpha) + \
2580 (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \
2581 127) / 255))
2582
2583 # define png_composite_16(composite, fg, alpha, bg) \
2584 (composite) = \
2585 (png_uint_16)(0xffff & (((png_uint_32)(fg) * (png_uint_32)(alpha) + \
2586 (png_uint_32)(bg)*(png_uint_32)(65535 - (png_uint_32)(alpha)) + \
2587 32767) / 65535))
2588 #endif /* READ_COMPOSITE_NODIV */
2589
2590 #ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED
2591 PNG_EXPORT(201, png_uint_32, png_get_uint_32, (png_const_bytep buf));
2592 PNG_EXPORT(202, png_uint_16, png_get_uint_16, (png_const_bytep buf));
2593 PNG_EXPORT(203, png_int_32, png_get_int_32, (png_const_bytep buf));
2594 #endif
2595
2596 PNG_EXPORT(204, png_uint_32, png_get_uint_31, (png_const_structrp png_ptr,
2597 png_const_bytep buf));
2598 /* No png_get_int_16 -- may be added if there's a real need for it. */
2599
2600 /* Place a 32-bit number into a buffer in PNG byte order (big-endian). */
2601 #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
2602 PNG_EXPORT(205, void, png_save_uint_32, (png_bytep buf, png_uint_32 i));
2603 #endif
2604 #ifdef PNG_SAVE_INT_32_SUPPORTED
2605 PNG_EXPORT(206, void, png_save_int_32, (png_bytep buf, png_int_32 i));
2606 #endif
2607
2608 /* Place a 16-bit number into a buffer in PNG byte order.
2609 * The parameter is declared unsigned int, not png_uint_16,
2610 * just to avoid potential problems on pre-ANSI C compilers.
2611 */
2612 #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
2613 PNG_EXPORT(207, void, png_save_uint_16, (png_bytep buf, unsigned int i));
2614 /* No png_save_int_16 -- may be added if there's a real need for it. */
2615 #endif
2616
2617 #ifdef PNG_USE_READ_MACROS
2618 /* Inline macros to do direct reads of bytes from the input buffer.
2619 * The png_get_int_32() routine assumes we are using two's complement
2620 * format for negative values, which is almost certainly true.
2621 */
2622 # define PNG_get_uint_32(buf) \
2623 (((png_uint_32)(*(buf)) << 24) + \
2624 ((png_uint_32)(*((buf) + 1)) << 16) + \
2625 ((png_uint_32)(*((buf) + 2)) << 8) + \
2626 ((png_uint_32)(*((buf) + 3))))
2627
2628 /* From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the
2629 * function) incorrectly returned a value of type png_uint_32.
2630 */
2631 # define PNG_get_uint_16(buf) \
2632 ((png_uint_16) \
2633 (((unsigned int)(*(buf)) << 8) + \
2634 ((unsigned int)(*((buf) + 1)))))
2635
2636 # define PNG_get_int_32(buf) \
2637 ((png_int_32)((*(buf) & 0x80) \
2638 ? -((png_int_32)(((png_get_uint_32(buf)^0xffffffffU)+1U)&0x7fffffffU)) \
2639 : (png_int_32)png_get_uint_32(buf)))
2640
2641 /* If PNG_PREFIX is defined the same thing as below happens in pnglibconf.h,
2642 * but defining a macro name prefixed with PNG_PREFIX.
2643 */
2644 # ifndef PNG_PREFIX
2645 # define png_get_uint_32(buf) PNG_get_uint_32(buf)
2646 # define png_get_uint_16(buf) PNG_get_uint_16(buf)
2647 # define png_get_int_32(buf) PNG_get_int_32(buf)
2648 # endif
2649 #else
2650 # ifdef PNG_PREFIX
2651 /* No macros; revert to the (redefined) function */
2652 # define PNG_get_uint_32 (png_get_uint_32)
2653 # define PNG_get_uint_16 (png_get_uint_16)
2654 # define PNG_get_int_32 (png_get_int_32)
2655 # endif
2656 #endif
2657
2658 #ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
2659 PNG_EXPORT(242, void, png_set_check_for_invalid_index,
2660 (png_structrp png_ptr, int allowed));
2661 # ifdef PNG_GET_PALETTE_MAX_SUPPORTED
2662 PNG_EXPORT(243, int, png_get_palette_max, (png_const_structp png_ptr,
2663 png_const_infop info_ptr));
2664 # endif
2665 #endif /* CHECK_FOR_INVALID_INDEX */
2666
2667 /*******************************************************************************
2668 * Section 5: SIMPLIFIED API
2669 *******************************************************************************
2670 *
2671 * Please read the documentation in libpng-manual.txt (TODO: write said
2672 * documentation) if you don't understand what follows.
2673 *
2674 * The simplified API hides the details of both libpng and the PNG file format
2675 * itself. It allows PNG files to be read into a very limited number of
2676 * in-memory bitmap formats or to be written from the same formats. If these
2677 * formats do not accomodate your needs then you can, and should, use the more
2678 * sophisticated APIs above - these support a wide variety of in-memory formats
2679 * and a wide variety of sophisticated transformations to those formats as well
2680 * as a wide variety of APIs to manipulate ancillary information.
2681 *
2682 * To read a PNG file using the simplified API:
2683 *
2684 * 1) Declare a 'png_image' structure (see below) on the stack, set the
2685 * version field to PNG_IMAGE_VERSION and the 'opaque' pointer to NULL
2686 * (this is REQUIRED, your program may crash if you don't do it.)
2687 * 2) Call the appropriate png_image_begin_read... function.
2688 * 3) Set the png_image 'format' member to the required sample format.
2689 * 4) Allocate a buffer for the image and, if required, the color-map.
2690 * 5) Call png_image_finish_read to read the image and, if required, the
2691 * color-map into your buffers.
2692 *
2693 * There are no restrictions on the format of the PNG input itself; all valid
2694 * color types, bit depths, and interlace methods are acceptable, and the
2695 * input image is transformed as necessary to the requested in-memory format
2696 * during the png_image_finish_read() step. The only caveat is that if you
2697 * request a color-mapped image from a PNG that is full-color or makes
2698 * complex use of an alpha channel the transformation is extremely lossy and the
2699 * result may look terrible.
2700 *
2701 * To write a PNG file using the simplified API:
2702 *
2703 * 1) Declare a 'png_image' structure on the stack and memset() it to all zero.
2704 * 2) Initialize the members of the structure that describe the image, setting
2705 * the 'format' member to the format of the image samples.
2706 * 3) Call the appropriate png_image_write... function with a pointer to the
2707 * image and, if necessary, the color-map to write the PNG data.
2708 *
2709 * png_image is a structure that describes the in-memory format of an image
2710 * when it is being read or defines the in-memory format of an image that you
2711 * need to write:
2712 */
2713 #if defined(PNG_SIMPLIFIED_READ_SUPPORTED) || \
2714 defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
2715
2716 #define PNG_IMAGE_VERSION 1
2717
2718 typedef struct png_control *png_controlp;
2719 typedef struct
2720 {
2721 png_controlp opaque; /* Initialize to NULL, free with png_image_free */
2722 png_uint_32 version; /* Set to PNG_IMAGE_VERSION */
2723 png_uint_32 width; /* Image width in pixels (columns) */
2724 png_uint_32 height; /* Image height in pixels (rows) */
2725 png_uint_32 format; /* Image format as defined below */
2726 png_uint_32 flags; /* A bit mask containing informational flags */
2727 png_uint_32 colormap_entries;
2728 /* Number of entries in the color-map */
2729
2730 /* In the event of an error or warning the following field will be set to a
2731 * non-zero value and the 'message' field will contain a '\0' terminated
2732 * string with the libpng error or warning message. If both warnings and
2733 * an error were encountered, only the error is recorded. If there
2734 * are multiple warnings, only the first one is recorded.
2735 *
2736 * The upper 30 bits of this value are reserved, the low two bits contain
2737 * a value as follows:
2738 */
2739 # define PNG_IMAGE_WARNING 1
2740 # define PNG_IMAGE_ERROR 2
2741 /*
2742 * The result is a two-bit code such that a value more than 1 indicates
2743 * a failure in the API just called:
2744 *
2745 * 0 - no warning or error
2746 * 1 - warning
2747 * 2 - error
2748 * 3 - error preceded by warning
2749 */
2750 # define PNG_IMAGE_FAILED(png_cntrl) ((((png_cntrl).warning_or_error)&0x03)>1)
2751
2752 png_uint_32 warning_or_error;
2753
2754 char message[64];
2755 } png_image, *png_imagep;
2756
2757 /* The samples of the image have one to four channels whose components have
2758 * original values in the range 0 to 1.0:
2759 *
2760 * 1: A single gray or luminance channel (G).
2761 * 2: A gray/luminance channel and an alpha channel (GA).
2762 * 3: Three red, green, blue color channels (RGB).
2763 * 4: Three color channels and an alpha channel (RGBA).
2764 *
2765 * The components are encoded in one of two ways:
2766 *
2767 * a) As a small integer, value 0..255, contained in a single byte. For the
2768 * alpha channel the original value is simply value/255. For the color or
2769 * luminance channels the value is encoded according to the sRGB specification
2770 * and matches the 8-bit format expected by typical display devices.
2771 *
2772 * The color/gray channels are not scaled (pre-multiplied) by the alpha
2773 * channel and are suitable for passing to color management software.
2774 *
2775 * b) As a value in the range 0..65535, contained in a 2-byte integer. All
2776 * channels can be converted to the original value by dividing by 65535; all
2777 * channels are linear. Color channels use the RGB encoding (RGB end-points) of
2778 * the sRGB specification. This encoding is identified by the
2779 * PNG_FORMAT_FLAG_LINEAR flag below.
2780 *
2781 * When the simplified API needs to convert between sRGB and linear colorspaces,
2782 * the actual sRGB transfer curve defined in the sRGB specification (see the
2783 * article at http://en.wikipedia.org/wiki/SRGB) is used, not the gamma=1/2.2
2784 * approximation used elsewhere in libpng.
2785 *
2786 * When an alpha channel is present it is expected to denote pixel coverage
2787 * of the color or luminance channels and is returned as an associated alpha
2788 * channel: the color/gray channels are scaled (pre-multiplied) by the alpha
2789 * value.
2790 *
2791 * The samples are either contained directly in the image data, between 1 and 8
2792 * bytes per pixel according to the encoding, or are held in a color-map indexed
2793 * by bytes in the image data. In the case of a color-map the color-map entries
2794 * are individual samples, encoded as above, and the image data has one byte per
2795 * pixel to select the relevant sample from the color-map.
2796 */
2797
2798 /* PNG_FORMAT_*
2799 *
2800 * #defines to be used in png_image::format. Each #define identifies a
2801 * particular layout of sample data and, if present, alpha values. There are
2802 * separate defines for each of the two component encodings.
2803 *
2804 * A format is built up using single bit flag values. All combinations are
2805 * valid. Formats can be built up from the flag values or you can use one of
2806 * the predefined values below. When testing formats always use the FORMAT_FLAG
2807 * macros to test for individual features - future versions of the library may
2808 * add new flags.
2809 *
2810 * When reading or writing color-mapped images the format should be set to the
2811 * format of the entries in the color-map then png_image_{read,write}_colormap
2812 * called to read or write the color-map and set the format correctly for the
2813 * image data. Do not set the PNG_FORMAT_FLAG_COLORMAP bit directly!
2814 *
2815 * NOTE: libpng can be built with particular features disabled. If you see
2816 * compiler errors because the definition of one of the following flags has been
2817 * compiled out it is because libpng does not have the required support. It is
2818 * possible, however, for the libpng configuration to enable the format on just
2819 * read or just write; in that case you may see an error at run time. You can
2820 * guard against this by checking for the definition of the appropriate
2821 * "_SUPPORTED" macro, one of:
2822 *
2823 * PNG_SIMPLIFIED_{READ,WRITE}_{BGR,AFIRST}_SUPPORTED
2824 */
2825 #define PNG_FORMAT_FLAG_ALPHA 0x01U /* format with an alpha channel */
2826 #define PNG_FORMAT_FLAG_COLOR 0x02U /* color format: otherwise grayscale */
2827 #define PNG_FORMAT_FLAG_LINEAR 0x04U /* 2-byte channels else 1-byte */
2828 #define PNG_FORMAT_FLAG_COLORMAP 0x08U /* image data is color-mapped */
2829
2830 #ifdef PNG_FORMAT_BGR_SUPPORTED
2831 # define PNG_FORMAT_FLAG_BGR 0x10U /* BGR colors, else order is RGB */
2832 #endif
2833
2834 #ifdef PNG_FORMAT_AFIRST_SUPPORTED
2835 # define PNG_FORMAT_FLAG_AFIRST 0x20U /* alpha channel comes first */
2836 #endif
2837
2838 /* Commonly used formats have predefined macros.
2839 *
2840 * First the single byte (sRGB) formats:
2841 */
2842 #define PNG_FORMAT_GRAY 0
2843 #define PNG_FORMAT_GA PNG_FORMAT_FLAG_ALPHA
2844 #define PNG_FORMAT_AG (PNG_FORMAT_GA|PNG_FORMAT_FLAG_AFIRST)
2845 #define PNG_FORMAT_RGB PNG_FORMAT_FLAG_COLOR
2846 #define PNG_FORMAT_BGR (PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_BGR)
2847 #define PNG_FORMAT_RGBA (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_ALPHA)
2848 #define PNG_FORMAT_ARGB (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_AFIRST)
2849 #define PNG_FORMAT_BGRA (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_ALPHA)
2850 #define PNG_FORMAT_ABGR (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_AFIRST)
2851
2852 /* Then the linear 2-byte formats. When naming these "Y" is used to
2853 * indicate a luminance (gray) channel.
2854 */
2855 #define PNG_FORMAT_LINEAR_Y PNG_FORMAT_FLAG_LINEAR
2856 #define PNG_FORMAT_LINEAR_Y_ALPHA (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_ALPHA)
2857 #define PNG_FORMAT_LINEAR_RGB (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR)
2858 #define PNG_FORMAT_LINEAR_RGB_ALPHA \
2859 (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA)
2860
2861 /* With color-mapped formats the image data is one byte for each pixel, the byte
2862 * is an index into the color-map which is formatted as above. To obtain a
2863 * color-mapped format it is sufficient just to add the PNG_FOMAT_FLAG_COLORMAP
2864 * to one of the above definitions, or you can use one of the definitions below.
2865 */
2866 #define PNG_FORMAT_RGB_COLORMAP (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_COLORMAP)
2867 #define PNG_FORMAT_BGR_COLORMAP (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_COLORMAP)
2868 #define PNG_FORMAT_RGBA_COLORMAP (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_COLORMAP)
2869 #define PNG_FORMAT_ARGB_COLORMAP (PNG_FORMAT_ARGB|PNG_FORMAT_FLAG_COLORMAP)
2870 #define PNG_FORMAT_BGRA_COLORMAP (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_COLORMAP)
2871 #define PNG_FORMAT_ABGR_COLORMAP (PNG_FORMAT_ABGR|PNG_FORMAT_FLAG_COLORMAP)
2872
2873 /* PNG_IMAGE macros
2874 *
2875 * These are convenience macros to derive information from a png_image
2876 * structure. The PNG_IMAGE_SAMPLE_ macros return values appropriate to the
2877 * actual image sample values - either the entries in the color-map or the
2878 * pixels in the image. The PNG_IMAGE_PIXEL_ macros return corresponding values
2879 * for the pixels and will always return 1 for color-mapped formats. The
2880 * remaining macros return information about the rows in the image and the
2881 * complete image.
2882 *
2883 * NOTE: All the macros that take a png_image::format parameter are compile time
2884 * constants if the format parameter is, itself, a constant. Therefore these
2885 * macros can be used in array declarations and case labels where required.
2886 * Similarly the macros are also pre-processor constants (sizeof is not used) so
2887 * they can be used in #if tests.
2888 *
2889 * First the information about the samples.
2890 */
2891 #define PNG_IMAGE_SAMPLE_CHANNELS(fmt)\
2892 (((fmt)&(PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA))+1)
2893 /* Return the total number of channels in a given format: 1..4 */
2894
2895 #define PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)\
2896 ((((fmt) & PNG_FORMAT_FLAG_LINEAR) >> 2)+1)
2897 /* Return the size in bytes of a single component of a pixel or color-map
2898 * entry (as appropriate) in the image: 1 or 2.
2899 */
2900
2901 #define PNG_IMAGE_SAMPLE_SIZE(fmt)\
2902 (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt))
2903 /* This is the size of the sample data for one sample. If the image is
2904 * color-mapped it is the size of one color-map entry (and image pixels are
2905 * one byte in size), otherwise it is the size of one image pixel.
2906 */
2907
2908 #define PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(fmt)\
2909 (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * 256)
2910 /* The maximum size of the color-map required by the format expressed in a
2911 * count of components. This can be used to compile-time allocate a
2912 * color-map:
2913 *
2914 * png_uint_16 colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(linear_fmt)];
2915 *
2916 * png_byte colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(sRGB_fmt)];
2917 *
2918 * Alternatively use the PNG_IMAGE_COLORMAP_SIZE macro below to use the
2919 * information from one of the png_image_begin_read_ APIs and dynamically
2920 * allocate the required memory.
2921 */
2922
2923 /* Corresponding information about the pixels */
2924 #define PNG_IMAGE_PIXEL_(test,fmt)\
2925 (((fmt)&PNG_FORMAT_FLAG_COLORMAP)?1:test(fmt))
2926
2927 #define PNG_IMAGE_PIXEL_CHANNELS(fmt)\
2928 PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_CHANNELS,fmt)
2929 /* The number of separate channels (components) in a pixel; 1 for a
2930 * color-mapped image.
2931 */
2932
2933 #define PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt)\
2934 PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_COMPONENT_SIZE,fmt)
2935 /* The size, in bytes, of each component in a pixel; 1 for a color-mapped
2936 * image.
2937 */
2938
2939 #define PNG_IMAGE_PIXEL_SIZE(fmt) PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_SIZE,fmt)
2940 /* The size, in bytes, of a complete pixel; 1 for a color-mapped image. */
2941
2942 /* Information about the whole row, or whole image */
2943 #define PNG_IMAGE_ROW_STRIDE(image)\
2944 (PNG_IMAGE_PIXEL_CHANNELS((image).format) * (image).width)
2945 /* Return the total number of components in a single row of the image; this
2946 * is the minimum 'row stride', the minimum count of components between each
2947 * row. For a color-mapped image this is the minimum number of bytes in a
2948 * row.
2949 *
2950 * WARNING: this macro overflows for some images with more than one component
2951 * and very large image widths. libpng will refuse to process an image where
2952 * this macro would overflow.
2953 */
2954
2955 #define PNG_IMAGE_BUFFER_SIZE(image, row_stride)\
2956 (PNG_IMAGE_PIXEL_COMPONENT_SIZE((image).format)*(image).height*(row_stride))
2957 /* Return the size, in bytes, of an image buffer given a png_image and a row
2958 * stride - the number of components to leave space for in each row.
2959 *
2960 * WARNING: this macro overflows a 32-bit integer for some large PNG images,
2961 * libpng will refuse to process an image where such an overflow would occur.
2962 */
2963
2964 #define PNG_IMAGE_SIZE(image)\
2965 PNG_IMAGE_BUFFER_SIZE(image, PNG_IMAGE_ROW_STRIDE(image))
2966 /* Return the size, in bytes, of the image in memory given just a png_image;
2967 * the row stride is the minimum stride required for the image.
2968 */
2969
2970 #define PNG_IMAGE_COLORMAP_SIZE(image)\
2971 (PNG_IMAGE_SAMPLE_SIZE((image).format) * (image).colormap_entries)
2972 /* Return the size, in bytes, of the color-map of this image. If the image
2973 * format is not a color-map format this will return a size sufficient for
2974 * 256 entries in the given format; check PNG_FORMAT_FLAG_COLORMAP if
2975 * you don't want to allocate a color-map in this case.
2976 */
2977
2978 /* PNG_IMAGE_FLAG_*
2979 *
2980 * Flags containing additional information about the image are held in the
2981 * 'flags' field of png_image.
2982 */
2983 #define PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB 0x01
2984 /* This indicates the the RGB values of the in-memory bitmap do not
2985 * correspond to the red, green and blue end-points defined by sRGB.
2986 */
2987
2988 #define PNG_IMAGE_FLAG_FAST 0x02
2989 /* On write emphasise speed over compression; the resultant PNG file will be
2990 * larger but will be produced significantly faster, particular for large
2991 * images. Do not use this option for images which will be distributed, only
2992 * used it when producing intermediate files that will be read back in
2993 * repeatedly. For a typical 24-bit image the option will double the read
2994 * speed at the cost of increasing the image size by 25%, however for many
2995 * more compressible images the PNG file can be 10 times larger with only a
2996 * slight speed gain.
2997 */
2998
2999 #define PNG_IMAGE_FLAG_16BIT_sRGB 0x04
3000 /* On read if the image is a 16-bit per component image and there is no gAMA
3001 * or sRGB chunk assume that the components are sRGB encoded. Notice that
3002 * images output by the simplified API always have gamma information; setting
3003 * this flag only affects the interpretation of 16-bit images from an
3004 * external source. It is recommended that the application expose this flag
3005 * to the user; the user can normally easily recognize the difference between
3006 * linear and sRGB encoding. This flag has no effect on write - the data
3007 * passed to the write APIs must have the correct encoding (as defined
3008 * above.)
3009 *
3010 * If the flag is not set (the default) input 16-bit per component data is
3011 * assumed to be linear.
3012 *
3013 * NOTE: the flag can only be set after the png_image_begin_read_ call,
3014 * because that call initializes the 'flags' field.
3015 */
3016
3017 #ifdef PNG_SIMPLIFIED_READ_SUPPORTED
3018 /* READ APIs
3019 * ---------
3020 *
3021 * The png_image passed to the read APIs must have been initialized by setting
3022 * the png_controlp field 'opaque' to NULL (or, safer, memset the whole thing.)
3023 */
3024 #ifdef PNG_STDIO_SUPPORTED
3025 PNG_EXPORT(234, int, png_image_begin_read_from_file, (png_imagep image,
3026 const char *file_name));
3027 /* The named file is opened for read and the image header is filled in
3028 * from the PNG header in the file.
3029 */
3030
3031 PNG_EXPORT(235, int, png_image_begin_read_from_stdio, (png_imagep image,
3032 FILE* file));
3033 /* The PNG header is read from the stdio FILE object. */
3034 #endif /* STDIO */
3035
3036 PNG_EXPORT(236, int, png_image_begin_read_from_memory, (png_imagep image,
3037 png_const_voidp memory, png_size_t size));
3038 /* The PNG header is read from the given memory buffer. */
3039
3040 PNG_EXPORT(237, int, png_image_finish_read, (png_imagep image,
3041 png_const_colorp background, void *buffer, png_int_32 row_stride,
3042 void *colormap));
3043 /* Finish reading the image into the supplied buffer and clean up the
3044 * png_image structure.
3045 *
3046 * row_stride is the step, in byte or 2-byte units as appropriate,
3047 * between adjacent rows. A positive stride indicates that the top-most row
3048 * is first in the buffer - the normal top-down arrangement. A negative
3049 * stride indicates that the bottom-most row is first in the buffer.
3050 *
3051 * background need only be supplied if an alpha channel must be removed from
3052 * a png_byte format and the removal is to be done by compositing on a solid
3053 * color; otherwise it may be NULL and any composition will be done directly
3054 * onto the buffer. The value is an sRGB color to use for the background,
3055 * for grayscale output the green channel is used.
3056 *
3057 * background must be supplied when an alpha channel must be removed from a
3058 * single byte color-mapped output format, in other words if:
3059 *
3060 * 1) The original format from png_image_begin_read_from_* had
3061 * PNG_FORMAT_FLAG_ALPHA set.
3062 * 2) The format set by the application does not.
3063 * 3) The format set by the application has PNG_FORMAT_FLAG_COLORMAP set and
3064 * PNG_FORMAT_FLAG_LINEAR *not* set.
3065 *
3066 * For linear output removing the alpha channel is always done by compositing
3067 * on black and background is ignored.
3068 *
3069 * colormap must be supplied when PNG_FORMAT_FLAG_COLORMAP is set. It must
3070 * be at least the size (in bytes) returned by PNG_IMAGE_COLORMAP_SIZE.
3071 * image->colormap_entries will be updated to the actual number of entries
3072 * written to the colormap; this may be less than the original value.
3073 */
3074
3075 PNG_EXPORT(238, void, png_image_free, (png_imagep image));
3076 /* Free any data allocated by libpng in image->opaque, setting the pointer to
3077 * NULL. May be called at any time after the structure is initialized.
3078 */
3079 #endif /* SIMPLIFIED_READ */
3080
3081 #ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED
3082 /* WRITE APIS
3083 * ----------
3084 * For write you must initialize a png_image structure to describe the image to
3085 * be written. To do this use memset to set the whole structure to 0 then
3086 * initialize fields describing your image.
3087 *
3088 * version: must be set to PNG_IMAGE_VERSION
3089 * opaque: must be initialized to NULL
3090 * width: image width in pixels
3091 * height: image height in rows
3092 * format: the format of the data (image and color-map) you wish to write
3093 * flags: set to 0 unless one of the defined flags applies; set
3094 * PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB for color format images where the RGB
3095 * values do not correspond to the colors in sRGB.
3096 * colormap_entries: set to the number of entries in the color-map (0 to 256)
3097 */
3098 #ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED
3099 PNG_EXPORT(239, int, png_image_write_to_file, (png_imagep image,
3100 const char *file, int convert_to_8bit, const void *buffer,
3101 png_int_32 row_stride, const void *colormap));
3102 /* Write the image to the named file. */
3103
3104 PNG_EXPORT(240, int, png_image_write_to_stdio, (png_imagep image, FILE *file,
3105 int convert_to_8_bit, const void *buffer, png_int_32 row_stride,
3106 const void *colormap));
3107 /* Write the image to the given (FILE*). */
3108 #endif /* SIMPLIFIED_WRITE_STDIO */
3109
3110 /* With all write APIs if image is in one of the linear formats with 16-bit
3111 * data then setting convert_to_8_bit will cause the output to be an 8-bit PNG
3112 * gamma encoded according to the sRGB specification, otherwise a 16-bit linear
3113 * encoded PNG file is written.
3114 *
3115 * With color-mapped data formats the colormap parameter point to a color-map
3116 * with at least image->colormap_entries encoded in the specified format. If
3117 * the format is linear the written PNG color-map will be converted to sRGB
3118 * regardless of the convert_to_8_bit flag.
3119 *
3120 * With all APIs row_stride is handled as in the read APIs - it is the spacing
3121 * from one row to the next in component sized units (1 or 2 bytes) and if
3122 * negative indicates a bottom-up row layout in the buffer. If row_stride is
3123 * zero, libpng will calculate it for you from the image width and number of
3124 * channels.
3125 *
3126 * Note that the write API does not support interlacing, sub-8-bit pixels or
3127 * most ancillary chunks. If you need to write text chunks (e.g. for copyright
3128 * notices) you need to use one of the other APIs.
3129 */
3130
3131 PNG_EXPORT(245, int, png_image_write_to_memory, (png_imagep image, void *memory,
3132 png_alloc_size_t * PNG_RESTRICT memory_bytes, int convert_to_8_bit,
3133 const void *buffer, png_int_32 row_stride, const void *colormap));
3134 /* Write the image to the given memory buffer. The function both writes the
3135 * whole PNG data stream to *memory and updates *memory_bytes with the count
3136 * of bytes written.
3137 *
3138 * 'memory' may be NULL. In this case *memory_bytes is not read however on
3139 * success the number of bytes which would have been written will still be
3140 * stored in *memory_bytes. On failure *memory_bytes will contain 0.
3141 *
3142 * If 'memory' is not NULL it must point to memory[*memory_bytes] of
3143 * writeable memory.
3144 *
3145 * If the function returns success memory[*memory_bytes] (if 'memory' is not
3146 * NULL) contains the written PNG data. *memory_bytes will always be less
3147 * than or equal to the original value.
3148 *
3149 * If the function returns false and *memory_bytes was not changed an error
3150 * occured during write. If *memory_bytes was changed, or is not 0 if
3151 * 'memory' was NULL, the write would have succeeded but for the memory
3152 * buffer being too small. *memory_bytes contains the required number of
3153 * bytes and will be bigger that the original value.
3154 */
3155
3156 #define png_image_write_get_memory_size(image, size, convert_to_8_bit, buffer,\
3157 row_stride, colormap)\
3158 png_image_write_to_memory(&(image), 0, &(size), convert_to_8_bit, buffer,\
3159 row_stride, colormap)
3160 /* Return the amount of memory in 'size' required to compress this image.
3161 * The png_image structure 'image' must be filled in as in the above
3162 * function and must not be changed before the actual write call, the buffer
3163 * and all other parameters must also be identical to that in the final
3164 * write call. The 'size' variable need not be initialized.
3165 *
3166 * NOTE: the macro returns true/false, if false is returned 'size' will be
3167 * set to zero and the write failed and probably will fail if tried again.
3168 */
3169
3170 /* You can pre-allocate the buffer by making sure it is of sufficient size
3171 * regardless of the amount of compression achieved. The buffer size will
3172 * always be bigger than the original image and it will never be filled. The
3173 * following macros are provided to assist in allocating the buffer.
3174 */
3175 #define PNG_IMAGE_DATA_SIZE(image) (PNG_IMAGE_SIZE(image)+(image).height)
3176 /* The number of uncompressed bytes in the PNG byte encoding of the image;
3177 * uncompressing the PNG IDAT data will give this number of bytes.
3178 *
3179 * NOTE: while PNG_IMAGE_SIZE cannot overflow for an image in memory this
3180 * macro can because of the extra bytes used in the PNG byte encoding. You
3181 * need to avoid this macro if your image size approaches 2^30 in width or
3182 * height. The same goes for the remainder of these macros; they all produce
3183 * bigger numbers than the actual in-memory image size.
3184 */
3185 #ifndef PNG_ZLIB_MAX_SIZE
3186 # define PNG_ZLIB_MAX_SIZE(b) ((b)+(((b)+7U)>>3)+(((b)+63U)>>6)+11U)
3187 /* An upper bound on the number of compressed bytes given 'b' uncompressed
3188 * bytes. This is based on deflateBounds() in zlib; different
3189 * implementations of zlib compression may conceivably produce more data so
3190 * if your zlib implementation is not zlib itself redefine this macro
3191 * appropriately.
3192 */
3193 #endif
3194
3195 #define PNG_IMAGE_COMPRESSED_SIZE_MAX(image)\
3196 PNG_ZLIB_MAX_SIZE((png_alloc_size_t)PNG_IMAGE_DATA_SIZE(image))
3197 /* An upper bound on the size of the data in the PNG IDAT chunks. */
3198
3199 #define PNG_IMAGE_PNG_SIZE_MAX_(image, image_size)\
3200 ((8U/*sig*/+25U/*IHDR*/+16U/*gAMA*/+44U/*cHRM*/+12U/*IEND*/+\
3201 (((image).format&PNG_FORMAT_FLAG_COLORMAP)?/*colormap: PLTE, tRNS*/\
3202 12U+3U*(image).colormap_entries/*PLTE data*/+\
3203 (((image).format&PNG_FORMAT_FLAG_ALPHA)?\
3204 12U/*tRNS*/+(image).colormap_entries:0U):0U)+\
3205 12U)+(12U*((image_size)/PNG_ZBUF_SIZE))/*IDAT*/+(image_size))
3206 /* A helper for the following macro; if your compiler cannot handle the
3207 * following macro use this one with the result of
3208 * PNG_IMAGE_COMPRESSED_SIZE_MAX(image) as the second argument (most
3209 * compilers should handle this just fine.)
3210 */
3211
3212 #define PNG_IMAGE_PNG_SIZE_MAX(image)\
3213 PNG_IMAGE_PNG_SIZE_MAX_(image, PNG_IMAGE_COMPRESSED_SIZE_MAX(image))
3214 /* An upper bound on the total length of the PNG data stream for 'image'.
3215 * The result is of type png_alloc_size_t, on 32-bit systems this may
3216 * overflow even though PNG_IMAGE_DATA_SIZE does not overflow; the write will
3217 * run out of buffer space but return a corrected size which should work.
3218 */
3219 #endif /* SIMPLIFIED_WRITE */
3220 /*******************************************************************************
3221 * END OF SIMPLIFIED API
3222 ******************************************************************************/
3223 #endif /* SIMPLIFIED_{READ|WRITE} */
3224
3225 /*******************************************************************************
3226 * Section 6: IMPLEMENTATION OPTIONS
3227 *******************************************************************************
3228 *
3229 * Support for arbitrary implementation-specific optimizations. The API allows
3230 * particular options to be turned on or off. 'Option' is the number of the
3231 * option and 'onoff' is 0 (off) or non-0 (on). The value returned is given
3232 * by the PNG_OPTION_ defines below.
3233 *
3234 * HARDWARE: normally hardware capabilites, such as the Intel SSE instructions,
3235 * are detected at run time, however sometimes it may be impossible
3236 * to do this in user mode, in which case it is necessary to discover
3237 * the capabilities in an OS specific way. Such capabilities are
3238 * listed here when libpng has support for them and must be turned
3239 * ON by the application if present.
3240 *
3241 * SOFTWARE: sometimes software optimizations actually result in performance
3242 * decrease on some architectures or systems, or with some sets of
3243 * PNG images. 'Software' options allow such optimizations to be
3244 * selected at run time.
3245 */
3246 #ifdef PNG_SET_OPTION_SUPPORTED
3247 #ifdef PNG_ARM_NEON_API_SUPPORTED
3248 # define PNG_ARM_NEON 0 /* HARDWARE: ARM Neon SIMD instructions supported */
3249 #endif
3250 #define PNG_MAXIMUM_INFLATE_WINDOW 2 /* SOFTWARE: force maximum window */
3251 #define PNG_SKIP_sRGB_CHECK_PROFILE 4 /* SOFTWARE: Check ICC profile for sRGB */
3252 #define PNG_OPTION_NEXT 6 /* Next option - numbers must be even */
3253
3254 /* Return values: NOTE: there are four values and 'off' is *not* zero */
3255 #define PNG_OPTION_UNSET 0 /* Unset - defaults to off */
3256 #define PNG_OPTION_INVALID 1 /* Option number out of range */
3257 #define PNG_OPTION_OFF 2
3258 #define PNG_OPTION_ON 3
3259
3260 PNG_EXPORT(244, int, png_set_option, (png_structrp png_ptr, int option,
3261 int onoff));
3262 #endif /* SET_OPTION */
3263
3264 /*******************************************************************************
3265 * END OF HARDWARE AND SOFTWARE OPTIONS
3266 ******************************************************************************/
3267
3268 /* Maintainer: Put new public prototypes here ^, in libpng.3, in project
3269 * defs, and in scripts/symbols.def.
3270 */
3271
3272 /* The last ordinal number (this is the *last* one already used; the next
3273 * one to use is one more than this.)
3274 */
3275 #ifdef PNG_EXPORT_LAST_ORDINAL
3276 PNG_EXPORT_LAST_ORDINAL(245);
3277 #endif
3278
3279 #ifdef __cplusplus
3280 }
3281 #endif
3282
3283 #endif /* PNG_VERSION_INFO_ONLY */
3284 /* Do not put anything past this line */
3285 #endif /* PNG_H */