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 * libpng version 1.6.37 - April 14, 2019
28 *
29 * Copyright (c) 2018-2019 Cosmin Truta
30 * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
31 * Copyright (c) 1996-1997 Andreas Dilger
32 * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
33 *
34 * This code is released under the libpng license. (See LICENSE, below.)
35 *
36 * Authors and maintainers:
37 * libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
38 * libpng versions 0.89, June 1996, through 0.96, May 1997: Andreas Dilger
39 * libpng versions 0.97, January 1998, through 1.6.35, July 2018:
40 * Glenn Randers-Pehrson
41 * libpng versions 1.6.36, December 2018, through 1.6.37, April 2019:
42 * Cosmin Truta
43 * See also "Contributing Authors", below.
44 */
45
46 /*
47 * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE
48 * =========================================
49 *
50 * PNG Reference Library License version 2
51 * ---------------------------------------
52 *
53 * * Copyright (c) 1995-2019 The PNG Reference Library Authors.
54 * * Copyright (c) 2018-2019 Cosmin Truta.
55 * * Copyright (c) 2000-2002, 2004, 2006-2018 Glenn Randers-Pehrson.
56 * * Copyright (c) 1996-1997 Andreas Dilger.
57 * * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
58 *
59 * The software is supplied "as is", without warranty of any kind,
60 * express or implied, including, without limitation, the warranties
61 * of merchantability, fitness for a particular purpose, title, and
62 * non-infringement. In no event shall the Copyright owners, or
63 * anyone distributing the software, be liable for any damages or
64 * other liability, whether in contract, tort or otherwise, arising
65 * from, out of, or in connection with the software, or the use or
66 * other dealings in the software, even if advised of the possibility
67 * of such damage.
68 *
69 * Permission is hereby granted to use, copy, modify, and distribute
70 * this software, or portions hereof, for any purpose, without fee,
71 * subject to the following restrictions:
72 *
73 * 1. The origin of this software must not be misrepresented; you
74 * must not claim that you wrote the original software. If you
75 * use this software in a product, an acknowledgment in the product
76 * documentation would be appreciated, but is not required.
77 *
78 * 2. Altered source versions must be plainly marked as such, and must
79 * not be misrepresented as being the original software.
80 *
81 * 3. This Copyright notice may not be removed or altered from any
82 * source or altered source distribution.
83 *
84 *
85 * PNG Reference Library License version 1 (for libpng 0.5 through 1.6.35)
86 * -----------------------------------------------------------------------
87 *
88 * libpng versions 1.0.7, July 1, 2000, through 1.6.35, July 15, 2018 are
89 * Copyright (c) 2000-2002, 2004, 2006-2018 Glenn Randers-Pehrson, are
90 * derived from libpng-1.0.6, and are distributed according to the same
91 * disclaimer and license as libpng-1.0.6 with the following individuals
92 * added to the list of Contributing Authors:
93 *
94 * Simon-Pierre Cadieux
95 * Eric S. Raymond
96 * Mans Rullgard
97 * Cosmin Truta
98 * Gilles Vollant
99 * James Yu
100 * Mandar Sahastrabuddhe
101 * Google Inc.
102 * Vadim Barkov
103 *
104 * and with the following additions to the disclaimer:
105 *
106 * There is no warranty against interference with your enjoyment of
107 * the library or against infringement. There is no warranty that our
108 * efforts or the library will fulfill any of your particular purposes
109 * or needs. This library is provided with all faults, and the entire
110 * risk of satisfactory quality, performance, accuracy, and effort is
111 * with the user.
112 *
113 * Some files in the "contrib" directory and some configure-generated
114 * files that are distributed with libpng have other copyright owners, and
115 * are released under other open source licenses.
116 *
117 * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
118 * Copyright (c) 1998-2000 Glenn Randers-Pehrson, are derived from
119 * libpng-0.96, and are distributed according to the same disclaimer and
120 * license as libpng-0.96, with the following individuals added to the
121 * list of Contributing Authors:
122 *
123 * Tom Lane
124 * Glenn Randers-Pehrson
125 * Willem van Schaik
126 *
127 * libpng versions 0.89, June 1996, through 0.96, May 1997, are
128 * Copyright (c) 1996-1997 Andreas Dilger, are derived from libpng-0.88,
129 * and are distributed according to the same disclaimer and license as
130 * libpng-0.88, with the following individuals added to the list of
131 * Contributing Authors:
132 *
133 * John Bowler
134 * Kevin Bracey
135 * Sam Bushell
136 * Magnus Holmgren
137 * Greg Roelofs
138 * Tom Tanner
139 *
140 * Some files in the "scripts" directory have other copyright owners,
141 * but are released under this license.
142 *
143 * libpng versions 0.5, May 1995, through 0.88, January 1996, are
144 * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
145 *
146 * For the purposes of this copyright and license, "Contributing Authors"
147 * is defined as the following set of individuals:
148 *
149 * Andreas Dilger
150 * Dave Martindale
151 * Guy Eric Schalnat
152 * Paul Schmidt
153 * Tim Wegner
154 *
155 * The PNG Reference Library is supplied "AS IS". The Contributing
156 * Authors and Group 42, Inc. disclaim all warranties, expressed or
157 * implied, including, without limitation, the warranties of
158 * merchantability and of fitness for any purpose. The Contributing
159 * Authors and Group 42, Inc. assume no liability for direct, indirect,
160 * incidental, special, exemplary, or consequential damages, which may
161 * result from the use of the PNG Reference Library, even if advised of
162 * the possibility of such damage.
163 *
164 * Permission is hereby granted to use, copy, modify, and distribute this
165 * source code, or portions hereof, for any purpose, without fee, subject
166 * to the following restrictions:
167 *
168 * 1. The origin of this source code must not be misrepresented.
169 *
170 * 2. Altered versions must be plainly marked as such and must not
171 * be misrepresented as being the original source.
172 *
173 * 3. This Copyright notice may not be removed or altered from any
174 * source or altered source distribution.
175 *
176 * The Contributing Authors and Group 42, Inc. specifically permit,
177 * without fee, and encourage the use of this source code as a component
178 * to supporting the PNG file format in commercial products. If you use
179 * this source code in a product, acknowledgment is not required but would
180 * be appreciated.
181 *
182 * END OF COPYRIGHT NOTICE, DISCLAIMER, and LICENSE.
183 *
184 * TRADEMARK
185 * =========
186 *
187 * The name "libpng" has not been registered by the Copyright owners
188 * as a trademark in any jurisdiction. However, because libpng has
189 * been distributed and maintained world-wide, continually since 1995,
190 * the Copyright owners claim "common-law trademark protection" in any
191 * jurisdiction where common-law trademark is recognized.
192 */
193
194 /*
195 * A "png_get_copyright" function is available, for convenient use in "about"
196 * boxes and the like:
197 *
198 * printf("%s", png_get_copyright(NULL));
199 *
200 * Also, the PNG logo (in PNG format, of course) is supplied in the
201 * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
202 */
203
204 /*
205 * The contributing authors would like to thank all those who helped
206 * with testing, bug fixes, and patience. This wouldn't have been
207 * possible without all of you.
208 *
209 * Thanks to Frank J. T. Wojcik for helping with the documentation.
210 */
211
212 /* Note about libpng version numbers:
213 *
214 * Due to various miscommunications, unforeseen code incompatibilities
215 * and occasional factors outside the authors' control, version numbering
216 * on the library has not always been consistent and straightforward.
217 * The following table summarizes matters since version 0.89c, which was
218 * the first widely used release:
219 *
220 * source png.h png.h shared-lib
221 * version string int version
222 * ------- ------ ----- ----------
223 * 0.89c "1.0 beta 3" 0.89 89 1.0.89
224 * 0.90 "1.0 beta 4" 0.90 90 0.90 [should have been 2.0.90]
225 * 0.95 "1.0 beta 5" 0.95 95 0.95 [should have been 2.0.95]
226 * 0.96 "1.0 beta 6" 0.96 96 0.96 [should have been 2.0.96]
227 * 0.97b "1.00.97 beta 7" 1.00.97 97 1.0.1 [should have been 2.0.97]
228 * 0.97c 0.97 97 2.0.97
229 * 0.98 0.98 98 2.0.98
230 * 0.99 0.99 98 2.0.99
231 * 0.99a-m 0.99 99 2.0.99
232 * 1.00 1.00 100 2.1.0 [100 should be 10000]
233 * 1.0.0 (from here on, the 100 2.1.0 [100 should be 10000]
234 * 1.0.1 png.h string is 10001 2.1.0
235 * 1.0.1a-e identical to the 10002 from here on, the shared library
236 * 1.0.2 source version) 10002 is 2.V where V is the source code
237 * 1.0.2a-b 10003 version, except as noted.
238 * 1.0.3 10003
239 * 1.0.3a-d 10004
240 * 1.0.4 10004
241 * 1.0.4a-f 10005
242 * 1.0.5 (+ 2 patches) 10005
243 * 1.0.5a-d 10006
244 * 1.0.5e-r 10100 (not source compatible)
245 * 1.0.5s-v 10006 (not binary compatible)
246 * 1.0.6 (+ 3 patches) 10006 (still binary incompatible)
247 * 1.0.6d-f 10007 (still binary incompatible)
248 * 1.0.6g 10007
249 * 1.0.6h 10007 10.6h (testing xy.z so-numbering)
250 * 1.0.6i 10007 10.6i
251 * 1.0.6j 10007 2.1.0.6j (incompatible with 1.0.0)
252 * 1.0.7beta11-14 DLLNUM 10007 2.1.0.7beta11-14 (binary compatible)
253 * 1.0.7beta15-18 1 10007 2.1.0.7beta15-18 (binary compatible)
254 * 1.0.7rc1-2 1 10007 2.1.0.7rc1-2 (binary compatible)
255 * 1.0.7 1 10007 (still compatible)
256 * ...
257 * 1.0.69 10 10069 10.so.0.69[.0]
258 * ...
259 * 1.2.59 13 10259 12.so.0.59[.0]
260 * ...
261 * 1.4.20 14 10420 14.so.0.20[.0]
262 * ...
263 * 1.5.30 15 10530 15.so.15.30[.0]
264 * ...
265 * 1.6.37 16 10637 16.so.16.37[.0]
266 *
267 * Henceforth the source version will match the shared-library major and
268 * minor numbers; the shared-library major version number will be used for
269 * changes in backward compatibility, as it is intended.
270 * The PNG_LIBPNG_VER macro, which is not used within libpng but is
271 * available for applications, is an unsigned integer of the form XYYZZ
272 * corresponding to the source version X.Y.Z (leading zeros in Y and Z).
273 * Beta versions were given the previous public release number plus a
274 * letter, until version 1.0.6j; from then on they were given the upcoming
275 * public release number plus "betaNN" or "rcNN".
276 *
277 * Binary incompatibility exists only when applications make direct access
278 * to the info_ptr or png_ptr members through png.h, and the compiled
279 * application is loaded with a different version of the library.
280 *
281 * DLLNUM will change each time there are forward or backward changes
282 * in binary compatibility (e.g., when a new feature is added).
283 *
284 * See libpng.txt or libpng.3 for more information. The PNG specification
285 * is available as a W3C Recommendation and as an ISO/IEC Standard; see
286 * <https://www.w3.org/TR/2003/REC-PNG-20031110/>
287 */
288
289 #ifndef PNG_H
290 #define PNG_H
291
292 /* This is not the place to learn how to use libpng. The file libpng-manual.txt
293 * describes how to use libpng, and the file example.c summarizes it
294 * with some code on which to build. This file is useful for looking
295 * at the actual function definitions and structure components. If that
296 * file has been stripped from your copy of libpng, you can find it at
297 * <http://www.libpng.org/pub/png/libpng-manual.txt>
298 *
299 * If you just need to read a PNG file and don't want to read the documentation
300 * skip to the end of this file and read the section entitled 'simplified API'.
301 */
302
303 /* Version information for png.h - this should match the version in png.c */
304 #define PNG_LIBPNG_VER_STRING "1.6.37"
305 #define PNG_HEADER_VERSION_STRING " libpng version 1.6.37 - April 14, 2019\n"
306
307 #define PNG_LIBPNG_VER_SONUM 16
308 #define PNG_LIBPNG_VER_DLLNUM 16
309
310 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
311 #define PNG_LIBPNG_VER_MAJOR 1
312 #define PNG_LIBPNG_VER_MINOR 6
313 #define PNG_LIBPNG_VER_RELEASE 37
314
315 /* This should be zero for a public release, or non-zero for a
316 * development version. [Deprecated]
317 */
318 #define PNG_LIBPNG_VER_BUILD 0
319
320 /* Release Status */
321 #define PNG_LIBPNG_BUILD_ALPHA 1
322 #define PNG_LIBPNG_BUILD_BETA 2
323 #define PNG_LIBPNG_BUILD_RC 3
324 #define PNG_LIBPNG_BUILD_STABLE 4
325 #define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7
326
327 /* Release-Specific Flags */
328 #define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with
329 PNG_LIBPNG_BUILD_STABLE only */
330 #define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with
331 PNG_LIBPNG_BUILD_SPECIAL */
332 #define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with
333 PNG_LIBPNG_BUILD_PRIVATE */
334
335 #define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE
336
337 /* Careful here. At one time, Guy wanted to use 082, but that
338 * would be octal. We must not include leading zeros.
339 * Versions 0.7 through 1.0.0 were in the range 0 to 100 here
340 * (only version 1.0.0 was mis-numbered 100 instead of 10000).
341 * From version 1.0.1 it is:
342 * XXYYZZ, where XX=major, YY=minor, ZZ=release
343 */
344 #define PNG_LIBPNG_VER 10637 /* 1.6.37 */
345
346 /* Library configuration: these options cannot be changed after
347 * the library has been built.
348 */
349 #ifndef PNGLCONF_H
350 /* If pnglibconf.h is missing, you can
351 * copy scripts/pnglibconf.h.prebuilt to pnglibconf.h
352 */
353 # include "pnglibconf.h"
354 #endif
355
356 #ifndef PNG_VERSION_INFO_ONLY
357 /* Machine specific configuration. */
358 # include "pngconf.h"
359 #endif
360
361 /*
362 * Added at libpng-1.2.8
363 *
364 * Ref MSDN: Private as priority over Special
365 * VS_FF_PRIVATEBUILD File *was not* built using standard release
366 * procedures. If this value is given, the StringFileInfo block must
367 * contain a PrivateBuild string.
368 *
369 * VS_FF_SPECIALBUILD File *was* built by the original company using
370 * standard release procedures but is a variation of the standard
371 * file of the same version number. If this value is given, the
372 * StringFileInfo block must contain a SpecialBuild string.
373 */
374
375 #ifdef PNG_USER_PRIVATEBUILD /* From pnglibconf.h */
376 # define PNG_LIBPNG_BUILD_TYPE \
377 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE)
378 #else
379 # ifdef PNG_LIBPNG_SPECIALBUILD
380 # define PNG_LIBPNG_BUILD_TYPE \
381 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL)
382 # else
383 # define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE)
384 # endif
385 #endif
386
387 #ifndef PNG_VERSION_INFO_ONLY
388
389 /* Inhibit C++ name-mangling for libpng functions but not for system calls. */
390 #ifdef __cplusplus
391 extern "C" {
392 #endif /* __cplusplus */
393
394 /* Version information for C files, stored in png.c. This had better match
395 * the version above.
396 */
397 #define png_libpng_ver png_get_header_ver(NULL)
398
399 /* This file is arranged in several sections:
400 *
401 * 1. [omitted]
402 * 2. Any configuration options that can be specified by for the application
403 * code when it is built. (Build time configuration is in pnglibconf.h)
404 * 3. Type definitions (base types are defined in pngconf.h), structure
405 * definitions.
406 * 4. Exported library functions.
407 * 5. Simplified API.
408 * 6. Implementation options.
409 *
410 * The library source code has additional files (principally pngpriv.h) that
411 * allow configuration of the library.
412 */
413
414 /* Section 1: [omitted] */
415
416 /* Section 2: run time configuration
417 * See pnglibconf.h for build time configuration
418 *
419 * Run time configuration allows the application to choose between
420 * implementations of certain arithmetic APIs. The default is set
421 * at build time and recorded in pnglibconf.h, but it is safe to
422 * override these (and only these) settings. Note that this won't
423 * change what the library does, only application code, and the
424 * settings can (and probably should) be made on a per-file basis
425 * by setting the #defines before including png.h
426 *
427 * Use macros to read integers from PNG data or use the exported
428 * functions?
429 * PNG_USE_READ_MACROS: use the macros (see below) Note that
430 * the macros evaluate their argument multiple times.
431 * PNG_NO_USE_READ_MACROS: call the relevant library function.
432 *
433 * Use the alternative algorithm for compositing alpha samples that
434 * does not use division?
435 * PNG_READ_COMPOSITE_NODIV_SUPPORTED: use the 'no division'
436 * algorithm.
437 * PNG_NO_READ_COMPOSITE_NODIV: use the 'division' algorithm.
438 *
439 * How to handle benign errors if PNG_ALLOW_BENIGN_ERRORS is
440 * false?
441 * PNG_ALLOW_BENIGN_ERRORS: map calls to the benign error
442 * APIs to png_warning.
443 * Otherwise the calls are mapped to png_error.
444 */
445
446 /* Section 3: type definitions, including structures and compile time
447 * constants.
448 * See pngconf.h for base types that vary by machine/system
449 */
450
451 /* This triggers a compiler error in png.c, if png.c and png.h
452 * do not agree upon the version number.
453 */
454 typedef char* png_libpng_version_1_6_37;
455
456 /* Basic control structions. Read libpng-manual.txt or libpng.3 for more info.
457 *
458 * png_struct is the cache of information used while reading or writing a single
459 * PNG file. One of these is always required, although the simplified API
460 * (below) hides the creation and destruction of it.
461 */
462 typedef struct png_struct_def png_struct;
463 typedef const png_struct * png_const_structp;
464 typedef png_struct * png_structp;
465 typedef png_struct * * png_structpp;
466
467 /* png_info contains information read from or to be written to a PNG file. One
468 * or more of these must exist while reading or creating a PNG file. The
469 * information is not used by libpng during read but is used to control what
470 * gets written when a PNG file is created. "png_get_" function calls read
471 * information during read and "png_set_" functions calls write information
472 * when creating a PNG.
473 * been moved into a separate header file that is not accessible to
474 * applications. Read libpng-manual.txt or libpng.3 for more info.
475 */
476 typedef struct png_info_def png_info;
477 typedef png_info * png_infop;
478 typedef const png_info * png_const_infop;
479 typedef png_info * * png_infopp;
480
481 /* Types with names ending 'p' are pointer types. The corresponding types with
482 * names ending 'rp' are identical pointer types except that the pointer is
483 * marked 'restrict', which means that it is the only pointer to the object
484 * passed to the function. Applications should not use the 'restrict' types;
485 * it is always valid to pass 'p' to a pointer with a function argument of the
486 * corresponding 'rp' type. Different compilers have different rules with
487 * regard to type matching in the presence of 'restrict'. For backward
488 * compatibility libpng callbacks never have 'restrict' in their parameters and,
489 * consequentially, writing portable application code is extremely difficult if
490 * an attempt is made to use 'restrict'.
491 */
492 typedef png_struct * PNG_RESTRICT png_structrp;
493 typedef const png_struct * PNG_RESTRICT png_const_structrp;
494 typedef png_info * PNG_RESTRICT png_inforp;
495 typedef const png_info * PNG_RESTRICT png_const_inforp;
496
497 /* Three color definitions. The order of the red, green, and blue, (and the
498 * exact size) is not important, although the size of the fields need to
499 * be png_byte or png_uint_16 (as defined below).
500 */
501 typedef struct png_color_struct
502 {
503 png_byte red;
504 png_byte green;
505 png_byte blue;
506 } png_color;
507 typedef png_color * png_colorp;
508 typedef const png_color * png_const_colorp;
509 typedef png_color * * png_colorpp;
510
511 typedef struct png_color_16_struct
512 {
513 png_byte index; /* used for palette files */
514 png_uint_16 red; /* for use in red green blue files */
515 png_uint_16 green;
516 png_uint_16 blue;
517 png_uint_16 gray; /* for use in grayscale files */
518 } png_color_16;
519 typedef png_color_16 * png_color_16p;
520 typedef const png_color_16 * png_const_color_16p;
521 typedef png_color_16 * * png_color_16pp;
522
523 typedef struct png_color_8_struct
524 {
525 png_byte red; /* for use in red green blue files */
526 png_byte green;
527 png_byte blue;
528 png_byte gray; /* for use in grayscale files */
529 png_byte alpha; /* for alpha channel files */
530 } png_color_8;
531 typedef png_color_8 * png_color_8p;
532 typedef const png_color_8 * png_const_color_8p;
533 typedef png_color_8 * * png_color_8pp;
534
535 /*
536 * The following two structures are used for the in-core representation
537 * of sPLT chunks.
538 */
539 typedef struct png_sPLT_entry_struct
540 {
541 png_uint_16 red;
542 png_uint_16 green;
543 png_uint_16 blue;
544 png_uint_16 alpha;
545 png_uint_16 frequency;
546 } png_sPLT_entry;
547 typedef png_sPLT_entry * png_sPLT_entryp;
548 typedef const png_sPLT_entry * png_const_sPLT_entryp;
549 typedef png_sPLT_entry * * png_sPLT_entrypp;
550
551 /* When the depth of the sPLT palette is 8 bits, the color and alpha samples
552 * occupy the LSB of their respective members, and the MSB of each member
553 * is zero-filled. The frequency member always occupies the full 16 bits.
554 */
555
556 typedef struct png_sPLT_struct
557 {
558 png_charp name; /* palette name */
559 png_byte depth; /* depth of palette samples */
560 png_sPLT_entryp entries; /* palette entries */
561 png_int_32 nentries; /* number of palette entries */
562 } png_sPLT_t;
563 typedef png_sPLT_t * png_sPLT_tp;
564 typedef const png_sPLT_t * png_const_sPLT_tp;
565 typedef png_sPLT_t * * png_sPLT_tpp;
566
567 #ifdef PNG_TEXT_SUPPORTED
568 /* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,
569 * and whether that contents is compressed or not. The "key" field
570 * points to a regular zero-terminated C string. The "text" fields can be a
571 * regular C string, an empty string, or a NULL pointer.
572 * However, the structure returned by png_get_text() will always contain
573 * the "text" field as a regular zero-terminated C string (possibly
574 * empty), never a NULL pointer, so it can be safely used in printf() and
575 * other string-handling functions. Note that the "itxt_length", "lang", and
576 * "lang_key" members of the structure only exist when the library is built
577 * with iTXt chunk support. Prior to libpng-1.4.0 the library was built by
578 * default without iTXt support. Also note that when iTXt *is* supported,
579 * the "lang" and "lang_key" fields contain NULL pointers when the
580 * "compression" field contains * PNG_TEXT_COMPRESSION_NONE or
581 * PNG_TEXT_COMPRESSION_zTXt. Note that the "compression value" is not the
582 * same as what appears in the PNG tEXt/zTXt/iTXt chunk's "compression flag"
583 * which is always 0 or 1, or its "compression method" which is always 0.
584 */
585 typedef struct png_text_struct
586 {
587 int compression; /* compression value:
588 -1: tEXt, none
589 0: zTXt, deflate
590 1: iTXt, none
591 2: iTXt, deflate */
592 png_charp key; /* keyword, 1-79 character description of "text" */
593 png_charp text; /* comment, may be an empty string (ie "")
594 or a NULL pointer */
595 size_t text_length; /* length of the text string */
596 size_t itxt_length; /* length of the itxt string */
597 png_charp lang; /* language code, 0-79 characters
598 or a NULL pointer */
599 png_charp lang_key; /* keyword translated UTF-8 string, 0 or more
600 chars or a NULL pointer */
601 } png_text;
602 typedef png_text * png_textp;
603 typedef const png_text * png_const_textp;
604 typedef png_text * * png_textpp;
605 #endif
606
607 /* Supported compression types for text in PNG files (tEXt, and zTXt).
608 * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */
609 #define PNG_TEXT_COMPRESSION_NONE_WR -3
610 #define PNG_TEXT_COMPRESSION_zTXt_WR -2
611 #define PNG_TEXT_COMPRESSION_NONE -1
612 #define PNG_TEXT_COMPRESSION_zTXt 0
613 #define PNG_ITXT_COMPRESSION_NONE 1
614 #define PNG_ITXT_COMPRESSION_zTXt 2
615 #define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */
616
617 /* png_time is a way to hold the time in an machine independent way.
618 * Two conversions are provided, both from time_t and struct tm. There
619 * is no portable way to convert to either of these structures, as far
620 * as I know. If you know of a portable way, send it to me. As a side
621 * note - PNG has always been Year 2000 compliant!
622 */
623 typedef struct png_time_struct
624 {
625 png_uint_16 year; /* full year, as in, 1995 */
626 png_byte month; /* month of year, 1 - 12 */
627 png_byte day; /* day of month, 1 - 31 */
628 png_byte hour; /* hour of day, 0 - 23 */
629 png_byte minute; /* minute of hour, 0 - 59 */
630 png_byte second; /* second of minute, 0 - 60 (for leap seconds) */
631 } png_time;
632 typedef png_time * png_timep;
633 typedef const png_time * png_const_timep;
634 typedef png_time * * png_timepp;
635
636 #if defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) ||\
637 defined(PNG_USER_CHUNKS_SUPPORTED)
638 /* png_unknown_chunk is a structure to hold queued chunks for which there is
639 * no specific support. The idea is that we can use this to queue
640 * up private chunks for output even though the library doesn't actually
641 * know about their semantics.
642 *
643 * The data in the structure is set by libpng on read and used on write.
644 */
645 typedef struct png_unknown_chunk_t
646 {
647 png_byte name[5]; /* Textual chunk name with '\0' terminator */
648 png_byte *data; /* Data, should not be modified on read! */
649 size_t size;
650
651 /* On write 'location' must be set using the flag values listed below.
652 * Notice that on read it is set by libpng however the values stored have
653 * more bits set than are listed below. Always treat the value as a
654 * bitmask. On write set only one bit - setting multiple bits may cause the
655 * chunk to be written in multiple places.
656 */
657 png_byte location; /* mode of operation at read time */
658 }
659 png_unknown_chunk;
660
661 typedef png_unknown_chunk * png_unknown_chunkp;
662 typedef const png_unknown_chunk * png_const_unknown_chunkp;
663 typedef png_unknown_chunk * * png_unknown_chunkpp;
664 #endif
665
666 /* Flag values for the unknown chunk location byte. */
667 #define PNG_HAVE_IHDR 0x01
668 #define PNG_HAVE_PLTE 0x02
669 #define PNG_AFTER_IDAT 0x08
670
671 /* Maximum positive integer used in PNG is (2^31)-1 */
672 #define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL)
673 #define PNG_UINT_32_MAX ((png_uint_32)(-1))
674 #define PNG_SIZE_MAX ((size_t)(-1))
675
676 /* These are constants for fixed point values encoded in the
677 * PNG specification manner (x100000)
678 */
679 #define PNG_FP_1 100000
680 #define PNG_FP_HALF 50000
681 #define PNG_FP_MAX ((png_fixed_point)0x7fffffffL)
682 #define PNG_FP_MIN (-PNG_FP_MAX)
683
684 /* These describe the color_type field in png_info. */
685 /* color type masks */
686 #define PNG_COLOR_MASK_PALETTE 1
687 #define PNG_COLOR_MASK_COLOR 2
688 #define PNG_COLOR_MASK_ALPHA 4
689
690 /* color types. Note that not all combinations are legal */
691 #define PNG_COLOR_TYPE_GRAY 0
692 #define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
693 #define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR)
694 #define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
695 #define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
696 /* aliases */
697 #define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA
698 #define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA
699
700 /* This is for compression type. PNG 1.0-1.2 only define the single type. */
701 #define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */
702 #define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE
703
704 /* This is for filter type. PNG 1.0-1.2 only define the single type. */
705 #define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */
706 #define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */
707 #define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE
708
709 /* These are for the interlacing type. These values should NOT be changed. */
710 #define PNG_INTERLACE_NONE 0 /* Non-interlaced image */
711 #define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */
712 #define PNG_INTERLACE_LAST 2 /* Not a valid value */
713
714 /* These are for the oFFs chunk. These values should NOT be changed. */
715 #define PNG_OFFSET_PIXEL 0 /* Offset in pixels */
716 #define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */
717 #define PNG_OFFSET_LAST 2 /* Not a valid value */
718
719 /* These are for the pCAL chunk. These values should NOT be changed. */
720 #define PNG_EQUATION_LINEAR 0 /* Linear transformation */
721 #define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */
722 #define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */
723 #define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */
724 #define PNG_EQUATION_LAST 4 /* Not a valid value */
725
726 /* These are for the sCAL chunk. These values should NOT be changed. */
727 #define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */
728 #define PNG_SCALE_METER 1 /* meters per pixel */
729 #define PNG_SCALE_RADIAN 2 /* radians per pixel */
730 #define PNG_SCALE_LAST 3 /* Not a valid value */
731
732 /* These are for the pHYs chunk. These values should NOT be changed. */
733 #define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */
734 #define PNG_RESOLUTION_METER 1 /* pixels/meter */
735 #define PNG_RESOLUTION_LAST 2 /* Not a valid value */
736
737 /* These are for the sRGB chunk. These values should NOT be changed. */
738 #define PNG_sRGB_INTENT_PERCEPTUAL 0
739 #define PNG_sRGB_INTENT_RELATIVE 1
740 #define PNG_sRGB_INTENT_SATURATION 2
741 #define PNG_sRGB_INTENT_ABSOLUTE 3
742 #define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */
743
744 /* This is for text chunks */
745 #define PNG_KEYWORD_MAX_LENGTH 79
746
747 /* Maximum number of entries in PLTE/sPLT/tRNS arrays */
748 #define PNG_MAX_PALETTE_LENGTH 256
749
750 /* These determine if an ancillary chunk's data has been successfully read
751 * from the PNG header, or if the application has filled in the corresponding
752 * data in the info_struct to be written into the output file. The values
753 * of the PNG_INFO_<chunk> defines should NOT be changed.
754 */
755 #define PNG_INFO_gAMA 0x0001U
756 #define PNG_INFO_sBIT 0x0002U
757 #define PNG_INFO_cHRM 0x0004U
758 #define PNG_INFO_PLTE 0x0008U
759 #define PNG_INFO_tRNS 0x0010U
760 #define PNG_INFO_bKGD 0x0020U
761 #define PNG_INFO_hIST 0x0040U
762 #define PNG_INFO_pHYs 0x0080U
763 #define PNG_INFO_oFFs 0x0100U
764 #define PNG_INFO_tIME 0x0200U
765 #define PNG_INFO_pCAL 0x0400U
766 #define PNG_INFO_sRGB 0x0800U /* GR-P, 0.96a */
767 #define PNG_INFO_iCCP 0x1000U /* ESR, 1.0.6 */
768 #define PNG_INFO_sPLT 0x2000U /* ESR, 1.0.6 */
769 #define PNG_INFO_sCAL 0x4000U /* ESR, 1.0.6 */
770 #define PNG_INFO_IDAT 0x8000U /* ESR, 1.0.6 */
771 #define PNG_INFO_eXIf 0x10000U /* GR-P, 1.6.31 */
772
773 /* This is used for the transformation routines, as some of them
774 * change these values for the row. It also should enable using
775 * the routines for other purposes.
776 */
777 typedef struct png_row_info_struct
778 {
779 png_uint_32 width; /* width of row */
780 size_t rowbytes; /* number of bytes in row */
781 png_byte color_type; /* color type of row */
782 png_byte bit_depth; /* bit depth of row */
783 png_byte channels; /* number of channels (1, 2, 3, or 4) */
784 png_byte pixel_depth; /* bits per pixel (depth * channels) */
785 } png_row_info;
786
787 typedef png_row_info * png_row_infop;
788 typedef png_row_info * * png_row_infopp;
789
790 /* These are the function types for the I/O functions and for the functions
791 * that allow the user to override the default I/O functions with his or her
792 * own. The png_error_ptr type should match that of user-supplied warning
793 * and error functions, while the png_rw_ptr type should match that of the
794 * user read/write data functions. Note that the 'write' function must not
795 * modify the buffer it is passed. The 'read' function, on the other hand, is
796 * expected to return the read data in the buffer.
797 */
798 typedef PNG_CALLBACK(void, *png_error_ptr, (png_structp, png_const_charp));
799 typedef PNG_CALLBACK(void, *png_rw_ptr, (png_structp, png_bytep, size_t));
800 typedef PNG_CALLBACK(void, *png_flush_ptr, (png_structp));
801 typedef PNG_CALLBACK(void, *png_read_status_ptr, (png_structp, png_uint_32,
802 int));
803 typedef PNG_CALLBACK(void, *png_write_status_ptr, (png_structp, png_uint_32,
804 int));
805
806 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
807 typedef PNG_CALLBACK(void, *png_progressive_info_ptr, (png_structp, png_infop));
808 typedef PNG_CALLBACK(void, *png_progressive_end_ptr, (png_structp, png_infop));
809
810 /* The following callback receives png_uint_32 row_number, int pass for the
811 * png_bytep data of the row. When transforming an interlaced image the
812 * row number is the row number within the sub-image of the interlace pass, so
813 * the value will increase to the height of the sub-image (not the full image)
814 * then reset to 0 for the next pass.
815 *
816 * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
817 * find the output pixel (x,y) given an interlaced sub-image pixel
818 * (row,col,pass). (See below for these macros.)
819 */
820 typedef PNG_CALLBACK(void, *png_progressive_row_ptr, (png_structp, png_bytep,
821 png_uint_32, int));
822 #endif
823
824 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
825 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
826 typedef PNG_CALLBACK(void, *png_user_transform_ptr, (png_structp, png_row_infop,
827 png_bytep));
828 #endif
829
830 #ifdef PNG_USER_CHUNKS_SUPPORTED
831 typedef PNG_CALLBACK(int, *png_user_chunk_ptr, (png_structp,
832 png_unknown_chunkp));
833 #endif
834 #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
835 /* not used anywhere */
836 /* typedef PNG_CALLBACK(void, *png_unknown_chunk_ptr, (png_structp)); */
837 #endif
838
839 #ifdef PNG_SETJMP_SUPPORTED
840 /* This must match the function definition in <setjmp.h>, and the application
841 * must include this before png.h to obtain the definition of jmp_buf. The
842 * function is required to be PNG_NORETURN, but this is not checked. If the
843 * function does return the application will crash via an abort() or similar
844 * system level call.
845 *
846 * If you get a warning here while building the library you may need to make
847 * changes to ensure that pnglibconf.h records the calling convention used by
848 * your compiler. This may be very difficult - try using a different compiler
849 * to build the library!
850 */
851 PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)), typedef);
852 #endif
853
854 /* Transform masks for the high-level interface */
855 #define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */
856 #define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */
857 #define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */
858 #define PNG_TRANSFORM_PACKING 0x0004 /* read and write */
859 #define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */
860 #define PNG_TRANSFORM_EXPAND 0x0010 /* read only */
861 #define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */
862 #define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */
863 #define PNG_TRANSFORM_BGR 0x0080 /* read and write */
864 #define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */
865 #define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */
866 #define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */
867 #define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* write only */
868 /* Added to libpng-1.2.34 */
869 #define PNG_TRANSFORM_STRIP_FILLER_BEFORE PNG_TRANSFORM_STRIP_FILLER
870 #define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */
871 /* Added to libpng-1.4.0 */
872 #define PNG_TRANSFORM_GRAY_TO_RGB 0x2000 /* read only */
873 /* Added to libpng-1.5.4 */
874 #define PNG_TRANSFORM_EXPAND_16 0x4000 /* read only */
875 #if INT_MAX >= 0x8000 /* else this might break */
876 #define PNG_TRANSFORM_SCALE_16 0x8000 /* read only */
877 #endif
878
879 /* Flags for MNG supported features */
880 #define PNG_FLAG_MNG_EMPTY_PLTE 0x01
881 #define PNG_FLAG_MNG_FILTER_64 0x04
882 #define PNG_ALL_MNG_FEATURES 0x05
883
884 /* NOTE: prior to 1.5 these functions had no 'API' style declaration,
885 * this allowed the zlib default functions to be used on Windows
886 * platforms. In 1.5 the zlib default malloc (which just calls malloc and
887 * ignores the first argument) should be completely compatible with the
888 * following.
889 */
890 typedef PNG_CALLBACK(png_voidp, *png_malloc_ptr, (png_structp,
891 png_alloc_size_t));
892 typedef PNG_CALLBACK(void, *png_free_ptr, (png_structp, png_voidp));
893
894 /* Section 4: exported functions
895 * Here are the function definitions most commonly used. This is not
896 * the place to find out how to use libpng. See libpng-manual.txt for the
897 * full explanation, see example.c for the summary. This just provides
898 * a simple one line description of the use of each function.
899 *
900 * The PNG_EXPORT() and PNG_EXPORTA() macros used below are defined in
901 * pngconf.h and in the *.dfn files in the scripts directory.
902 *
903 * PNG_EXPORT(ordinal, type, name, (args));
904 *
905 * ordinal: ordinal that is used while building
906 * *.def files. The ordinal value is only
907 * relevant when preprocessing png.h with
908 * the *.dfn files for building symbol table
909 * entries, and are removed by pngconf.h.
910 * type: return type of the function
911 * name: function name
912 * args: function arguments, with types
913 *
914 * When we wish to append attributes to a function prototype we use
915 * the PNG_EXPORTA() macro instead.
916 *
917 * PNG_EXPORTA(ordinal, type, name, (args), attributes);
918 *
919 * ordinal, type, name, and args: same as in PNG_EXPORT().
920 * attributes: function attributes
921 */
922
923 /* Returns the version number of the library */
924 PNG_EXPORT(1, png_uint_32, png_access_version_number, (void));
925
926 /* Tell lib we have already handled the first <num_bytes> magic bytes.
927 * Handling more than 8 bytes from the beginning of the file is an error.
928 */
929 PNG_EXPORT(2, void, png_set_sig_bytes, (png_structrp png_ptr, int num_bytes));
930
931 /* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
932 * PNG file. Returns zero if the supplied bytes match the 8-byte PNG
933 * signature, and non-zero otherwise. Having num_to_check == 0 or
934 * start > 7 will always fail (ie return non-zero).
935 */
936 PNG_EXPORT(3, int, png_sig_cmp, (png_const_bytep sig, size_t start,
937 size_t num_to_check));
938
939 /* Simple signature checking function. This is the same as calling
940 * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n).
941 */
942 #define png_check_sig(sig, n) !png_sig_cmp((sig), 0, (n))
943
944 /* Allocate and initialize png_ptr struct for reading, and any other memory. */
945 PNG_EXPORTA(4, png_structp, png_create_read_struct,
946 (png_const_charp user_png_ver, png_voidp error_ptr,
947 png_error_ptr error_fn, png_error_ptr warn_fn),
948 PNG_ALLOCATED);
949
950 /* Allocate and initialize png_ptr struct for writing, and any other memory */
951 PNG_EXPORTA(5, png_structp, png_create_write_struct,
952 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
953 png_error_ptr warn_fn),
954 PNG_ALLOCATED);
955
956 PNG_EXPORT(6, size_t, png_get_compression_buffer_size,
957 (png_const_structrp png_ptr));
958
959 PNG_EXPORT(7, void, png_set_compression_buffer_size, (png_structrp png_ptr,
960 size_t size));
961
962 /* Moved from pngconf.h in 1.4.0 and modified to ensure setjmp/longjmp
963 * match up.
964 */
965 #ifdef PNG_SETJMP_SUPPORTED
966 /* This function returns the jmp_buf built in to *png_ptr. It must be
967 * supplied with an appropriate 'longjmp' function to use on that jmp_buf
968 * unless the default error function is overridden in which case NULL is
969 * acceptable. The size of the jmp_buf is checked against the actual size
970 * allocated by the library - the call will return NULL on a mismatch
971 * indicating an ABI mismatch.
972 */
973 PNG_EXPORT(8, jmp_buf*, png_set_longjmp_fn, (png_structrp png_ptr,
974 png_longjmp_ptr longjmp_fn, size_t jmp_buf_size));
975 # define png_jmpbuf(png_ptr) \
976 (*png_set_longjmp_fn((png_ptr), longjmp, (sizeof (jmp_buf))))
977 #else
978 # define png_jmpbuf(png_ptr) \
979 (LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP)
980 #endif
981 /* This function should be used by libpng applications in place of
982 * longjmp(png_ptr->jmpbuf, val). If longjmp_fn() has been set, it
983 * will use it; otherwise it will call PNG_ABORT(). This function was
984 * added in libpng-1.5.0.
985 */
986 PNG_EXPORTA(9, void, png_longjmp, (png_const_structrp png_ptr, int val),
987 PNG_NORETURN);
988
989 #ifdef PNG_READ_SUPPORTED
990 /* Reset the compression stream */
991 PNG_EXPORTA(10, int, png_reset_zstream, (png_structrp png_ptr), PNG_DEPRECATED);
992 #endif
993
994 /* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */
995 #ifdef PNG_USER_MEM_SUPPORTED
996 PNG_EXPORTA(11, png_structp, png_create_read_struct_2,
997 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
998 png_error_ptr warn_fn,
999 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn),
1000 PNG_ALLOCATED);
1001 PNG_EXPORTA(12, png_structp, png_create_write_struct_2,
1002 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
1003 png_error_ptr warn_fn,
1004 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn),
1005 PNG_ALLOCATED);
1006 #endif
1007
1008 /* Write the PNG file signature. */
1009 PNG_EXPORT(13, void, png_write_sig, (png_structrp png_ptr));
1010
1011 /* Write a PNG chunk - size, type, (optional) data, CRC. */
1012 PNG_EXPORT(14, void, png_write_chunk, (png_structrp png_ptr, png_const_bytep
1013 chunk_name, png_const_bytep data, size_t length));
1014
1015 /* Write the start of a PNG chunk - length and chunk name. */
1016 PNG_EXPORT(15, void, png_write_chunk_start, (png_structrp png_ptr,
1017 png_const_bytep chunk_name, png_uint_32 length));
1018
1019 /* Write the data of a PNG chunk started with png_write_chunk_start(). */
1020 PNG_EXPORT(16, void, png_write_chunk_data, (png_structrp png_ptr,
1021 png_const_bytep data, size_t length));
1022
1023 /* Finish a chunk started with png_write_chunk_start() (includes CRC). */
1024 PNG_EXPORT(17, void, png_write_chunk_end, (png_structrp png_ptr));
1025
1026 /* Allocate and initialize the info structure */
1027 PNG_EXPORTA(18, png_infop, png_create_info_struct, (png_const_structrp png_ptr),
1028 PNG_ALLOCATED);
1029
1030 /* DEPRECATED: this function allowed init structures to be created using the
1031 * default allocation method (typically malloc). Use is deprecated in 1.6.0 and
1032 * the API will be removed in the future.
1033 */
1034 PNG_EXPORTA(19, void, png_info_init_3, (png_infopp info_ptr,
1035 size_t png_info_struct_size), PNG_DEPRECATED);
1036
1037 /* Writes all the PNG information before the image. */
1038 PNG_EXPORT(20, void, png_write_info_before_PLTE,
1039 (png_structrp png_ptr, png_const_inforp info_ptr));
1040 PNG_EXPORT(21, void, png_write_info,
1041 (png_structrp png_ptr, png_const_inforp info_ptr));
1042
1043 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1044 /* Read the information before the actual image data. */
1045 PNG_EXPORT(22, void, png_read_info,
1046 (png_structrp png_ptr, png_inforp info_ptr));
1047 #endif
1048
1049 #ifdef PNG_TIME_RFC1123_SUPPORTED
1050 /* Convert to a US string format: there is no localization support in this
1051 * routine. The original implementation used a 29 character buffer in
1052 * png_struct, this will be removed in future versions.
1053 */
1054 #if PNG_LIBPNG_VER < 10700
1055 /* To do: remove this from libpng17 (and from libpng17/png.c and pngstruct.h) */
1056 PNG_EXPORTA(23, png_const_charp, png_convert_to_rfc1123, (png_structrp png_ptr,
1057 png_const_timep ptime),PNG_DEPRECATED);
1058 #endif
1059 PNG_EXPORT(241, int, png_convert_to_rfc1123_buffer, (char out[29],
1060 png_const_timep ptime));
1061 #endif
1062
1063 #ifdef PNG_CONVERT_tIME_SUPPORTED
1064 /* Convert from a struct tm to png_time */
1065 PNG_EXPORT(24, void, png_convert_from_struct_tm, (png_timep ptime,
1066 const struct tm * ttime));
1067
1068 /* Convert from time_t to png_time. Uses gmtime() */
1069 PNG_EXPORT(25, void, png_convert_from_time_t, (png_timep ptime, time_t ttime));
1070 #endif /* CONVERT_tIME */
1071
1072 #ifdef PNG_READ_EXPAND_SUPPORTED
1073 /* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
1074 PNG_EXPORT(26, void, png_set_expand, (png_structrp png_ptr));
1075 PNG_EXPORT(27, void, png_set_expand_gray_1_2_4_to_8, (png_structrp png_ptr));
1076 PNG_EXPORT(28, void, png_set_palette_to_rgb, (png_structrp png_ptr));
1077 PNG_EXPORT(29, void, png_set_tRNS_to_alpha, (png_structrp png_ptr));
1078 #endif
1079
1080 #ifdef PNG_READ_EXPAND_16_SUPPORTED
1081 /* Expand to 16-bit channels, forces conversion of palette to RGB and expansion
1082 * of a tRNS chunk if present.
1083 */
1084 PNG_EXPORT(221, void, png_set_expand_16, (png_structrp png_ptr));
1085 #endif
1086
1087 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
1088 /* Use blue, green, red order for pixels. */
1089 PNG_EXPORT(30, void, png_set_bgr, (png_structrp png_ptr));
1090 #endif
1091
1092 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
1093 /* Expand the grayscale to 24-bit RGB if necessary. */
1094 PNG_EXPORT(31, void, png_set_gray_to_rgb, (png_structrp png_ptr));
1095 #endif
1096
1097 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1098 /* Reduce RGB to grayscale. */
1099 #define PNG_ERROR_ACTION_NONE 1
1100 #define PNG_ERROR_ACTION_WARN 2
1101 #define PNG_ERROR_ACTION_ERROR 3
1102 #define PNG_RGB_TO_GRAY_DEFAULT (-1)/*for red/green coefficients*/
1103
1104 PNG_FP_EXPORT(32, void, png_set_rgb_to_gray, (png_structrp png_ptr,
1105 int error_action, double red, double green))
1106 PNG_FIXED_EXPORT(33, void, png_set_rgb_to_gray_fixed, (png_structrp png_ptr,
1107 int error_action, png_fixed_point red, png_fixed_point green))
1108
1109 PNG_EXPORT(34, png_byte, png_get_rgb_to_gray_status, (png_const_structrp
1110 png_ptr));
1111 #endif
1112
1113 #ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED
1114 PNG_EXPORT(35, void, png_build_grayscale_palette, (int bit_depth,
1115 png_colorp palette));
1116 #endif
1117
1118 #ifdef PNG_READ_ALPHA_MODE_SUPPORTED
1119 /* How the alpha channel is interpreted - this affects how the color channels
1120 * of a PNG file are returned to the calling application when an alpha channel,
1121 * or a tRNS chunk in a palette file, is present.
1122 *
1123 * This has no effect on the way pixels are written into a PNG output
1124 * datastream. The color samples in a PNG datastream are never premultiplied
1125 * with the alpha samples.
1126 *
1127 * The default is to return data according to the PNG specification: the alpha
1128 * channel is a linear measure of the contribution of the pixel to the
1129 * corresponding composited pixel, and the color channels are unassociated
1130 * (not premultiplied). The gamma encoded color channels must be scaled
1131 * according to the contribution and to do this it is necessary to undo
1132 * the encoding, scale the color values, perform the composition and re-encode
1133 * the values. This is the 'PNG' mode.
1134 *
1135 * The alternative is to 'associate' the alpha with the color information by
1136 * storing color channel values that have been scaled by the alpha.
1137 * image. These are the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' modes
1138 * (the latter being the two common names for associated alpha color channels).
1139 *
1140 * For the 'OPTIMIZED' mode, a pixel is treated as opaque only if the alpha
1141 * value is equal to the maximum value.
1142 *
1143 * The final choice is to gamma encode the alpha channel as well. This is
1144 * broken because, in practice, no implementation that uses this choice
1145 * correctly undoes the encoding before handling alpha composition. Use this
1146 * choice only if other serious errors in the software or hardware you use
1147 * mandate it; the typical serious error is for dark halos to appear around
1148 * opaque areas of the composited PNG image because of arithmetic overflow.
1149 *
1150 * The API function png_set_alpha_mode specifies which of these choices to use
1151 * with an enumerated 'mode' value and the gamma of the required output:
1152 */
1153 #define PNG_ALPHA_PNG 0 /* according to the PNG standard */
1154 #define PNG_ALPHA_STANDARD 1 /* according to Porter/Duff */
1155 #define PNG_ALPHA_ASSOCIATED 1 /* as above; this is the normal practice */
1156 #define PNG_ALPHA_PREMULTIPLIED 1 /* as above */
1157 #define PNG_ALPHA_OPTIMIZED 2 /* 'PNG' for opaque pixels, else 'STANDARD' */
1158 #define PNG_ALPHA_BROKEN 3 /* the alpha channel is gamma encoded */
1159
1160 PNG_FP_EXPORT(227, void, png_set_alpha_mode, (png_structrp png_ptr, int mode,
1161 double output_gamma))
1162 PNG_FIXED_EXPORT(228, void, png_set_alpha_mode_fixed, (png_structrp png_ptr,
1163 int mode, png_fixed_point output_gamma))
1164 #endif
1165
1166 #if defined(PNG_GAMMA_SUPPORTED) || defined(PNG_READ_ALPHA_MODE_SUPPORTED)
1167 /* The output_gamma value is a screen gamma in libpng terminology: it expresses
1168 * how to decode the output values, not how they are encoded.
1169 */
1170 #define PNG_DEFAULT_sRGB -1 /* sRGB gamma and color space */
1171 #define PNG_GAMMA_MAC_18 -2 /* Old Mac '1.8' gamma and color space */
1172 #define PNG_GAMMA_sRGB 220000 /* Television standards--matches sRGB gamma */
1173 #define PNG_GAMMA_LINEAR PNG_FP_1 /* Linear */
1174 #endif
1175
1176 /* The following are examples of calls to png_set_alpha_mode to achieve the
1177 * required overall gamma correction and, where necessary, alpha
1178 * premultiplication.
1179 *
1180 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
1181 * This is the default libpng handling of the alpha channel - it is not
1182 * pre-multiplied into the color components. In addition the call states
1183 * that the output is for a sRGB system and causes all PNG files without gAMA
1184 * chunks to be assumed to be encoded using sRGB.
1185 *
1186 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
1187 * In this case the output is assumed to be something like an sRGB conformant
1188 * display preceded by a power-law lookup table of power 1.45. This is how
1189 * early Mac systems behaved.
1190 *
1191 * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR);
1192 * This is the classic Jim Blinn approach and will work in academic
1193 * environments where everything is done by the book. It has the shortcoming
1194 * of assuming that input PNG data with no gamma information is linear - this
1195 * is unlikely to be correct unless the PNG files where generated locally.
1196 * Most of the time the output precision will be so low as to show
1197 * significant banding in dark areas of the image.
1198 *
1199 * png_set_expand_16(pp);
1200 * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB);
1201 * This is a somewhat more realistic Jim Blinn inspired approach. PNG files
1202 * are assumed to have the sRGB encoding if not marked with a gamma value and
1203 * the output is always 16 bits per component. This permits accurate scaling
1204 * and processing of the data. If you know that your input PNG files were
1205 * generated locally you might need to replace PNG_DEFAULT_sRGB with the
1206 * correct value for your system.
1207 *
1208 * png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB);
1209 * If you just need to composite the PNG image onto an existing background
1210 * and if you control the code that does this you can use the optimization
1211 * setting. In this case you just copy completely opaque pixels to the
1212 * output. For pixels that are not completely transparent (you just skip
1213 * those) you do the composition math using png_composite or png_composite_16
1214 * below then encode the resultant 8-bit or 16-bit values to match the output
1215 * encoding.
1216 *
1217 * Other cases
1218 * If neither the PNG nor the standard linear encoding work for you because
1219 * of the software or hardware you use then you have a big problem. The PNG
1220 * case will probably result in halos around the image. The linear encoding
1221 * will probably result in a washed out, too bright, image (it's actually too
1222 * contrasty.) Try the ALPHA_OPTIMIZED mode above - this will probably
1223 * substantially reduce the halos. Alternatively try:
1224 *
1225 * png_set_alpha_mode(pp, PNG_ALPHA_BROKEN, PNG_DEFAULT_sRGB);
1226 * This option will also reduce the halos, but there will be slight dark
1227 * halos round the opaque parts of the image where the background is light.
1228 * In the OPTIMIZED mode the halos will be light halos where the background
1229 * is dark. Take your pick - the halos are unavoidable unless you can get
1230 * your hardware/software fixed! (The OPTIMIZED approach is slightly
1231 * faster.)
1232 *
1233 * When the default gamma of PNG files doesn't match the output gamma.
1234 * If you have PNG files with no gamma information png_set_alpha_mode allows
1235 * you to provide a default gamma, but it also sets the output gamma to the
1236 * matching value. If you know your PNG files have a gamma that doesn't
1237 * match the output you can take advantage of the fact that
1238 * png_set_alpha_mode always sets the output gamma but only sets the PNG
1239 * default if it is not already set:
1240 *
1241 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
1242 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
1243 * The first call sets both the default and the output gamma values, the
1244 * second call overrides the output gamma without changing the default. This
1245 * is easier than achieving the same effect with png_set_gamma. You must use
1246 * PNG_ALPHA_PNG for the first call - internal checking in png_set_alpha will
1247 * fire if more than one call to png_set_alpha_mode and png_set_background is
1248 * made in the same read operation, however multiple calls with PNG_ALPHA_PNG
1249 * are ignored.
1250 */
1251
1252 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
1253 PNG_EXPORT(36, void, png_set_strip_alpha, (png_structrp png_ptr));
1254 #endif
1255
1256 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
1257 defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
1258 PNG_EXPORT(37, void, png_set_swap_alpha, (png_structrp png_ptr));
1259 #endif
1260
1261 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
1262 defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
1263 PNG_EXPORT(38, void, png_set_invert_alpha, (png_structrp png_ptr));
1264 #endif
1265
1266 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
1267 /* Add a filler byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */
1268 PNG_EXPORT(39, void, png_set_filler, (png_structrp png_ptr, png_uint_32 filler,
1269 int flags));
1270 /* The values of the PNG_FILLER_ defines should NOT be changed */
1271 # define PNG_FILLER_BEFORE 0
1272 # define PNG_FILLER_AFTER 1
1273 /* Add an alpha byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */
1274 PNG_EXPORT(40, void, png_set_add_alpha, (png_structrp png_ptr,
1275 png_uint_32 filler, int flags));
1276 #endif /* READ_FILLER || WRITE_FILLER */
1277
1278 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
1279 /* Swap bytes in 16-bit depth files. */
1280 PNG_EXPORT(41, void, png_set_swap, (png_structrp png_ptr));
1281 #endif
1282
1283 #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
1284 /* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
1285 PNG_EXPORT(42, void, png_set_packing, (png_structrp png_ptr));
1286 #endif
1287
1288 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
1289 defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1290 /* Swap packing order of pixels in bytes. */
1291 PNG_EXPORT(43, void, png_set_packswap, (png_structrp png_ptr));
1292 #endif
1293
1294 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
1295 /* Converts files to legal bit depths. */
1296 PNG_EXPORT(44, void, png_set_shift, (png_structrp png_ptr, png_const_color_8p
1297 true_bits));
1298 #endif
1299
1300 #if defined(PNG_READ_INTERLACING_SUPPORTED) || \
1301 defined(PNG_WRITE_INTERLACING_SUPPORTED)
1302 /* Have the code handle the interlacing. Returns the number of passes.
1303 * MUST be called before png_read_update_info or png_start_read_image,
1304 * otherwise it will not have the desired effect. Note that it is still
1305 * necessary to call png_read_row or png_read_rows png_get_image_height
1306 * times for each pass.
1307 */
1308 PNG_EXPORT(45, int, png_set_interlace_handling, (png_structrp png_ptr));
1309 #endif
1310
1311 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
1312 /* Invert monochrome files */
1313 PNG_EXPORT(46, void, png_set_invert_mono, (png_structrp png_ptr));
1314 #endif
1315
1316 #ifdef PNG_READ_BACKGROUND_SUPPORTED
1317 /* Handle alpha and tRNS by replacing with a background color. Prior to
1318 * libpng-1.5.4 this API must not be called before the PNG file header has been
1319 * read. Doing so will result in unexpected behavior and possible warnings or
1320 * errors if the PNG file contains a bKGD chunk.
1321 */
1322 PNG_FP_EXPORT(47, void, png_set_background, (png_structrp png_ptr,
1323 png_const_color_16p background_color, int background_gamma_code,
1324 int need_expand, double background_gamma))
1325 PNG_FIXED_EXPORT(215, void, png_set_background_fixed, (png_structrp png_ptr,
1326 png_const_color_16p background_color, int background_gamma_code,
1327 int need_expand, png_fixed_point background_gamma))
1328 #endif
1329 #ifdef PNG_READ_BACKGROUND_SUPPORTED
1330 # define PNG_BACKGROUND_GAMMA_UNKNOWN 0
1331 # define PNG_BACKGROUND_GAMMA_SCREEN 1
1332 # define PNG_BACKGROUND_GAMMA_FILE 2
1333 # define PNG_BACKGROUND_GAMMA_UNIQUE 3
1334 #endif
1335
1336 #ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
1337 /* Scale a 16-bit depth file down to 8-bit, accurately. */
1338 PNG_EXPORT(229, void, png_set_scale_16, (png_structrp png_ptr));
1339 #endif
1340
1341 #ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
1342 #define PNG_READ_16_TO_8_SUPPORTED /* Name prior to 1.5.4 */
1343 /* Strip the second byte of information from a 16-bit depth file. */
1344 PNG_EXPORT(48, void, png_set_strip_16, (png_structrp png_ptr));
1345 #endif
1346
1347 #ifdef PNG_READ_QUANTIZE_SUPPORTED
1348 /* Turn on quantizing, and reduce the palette to the number of colors
1349 * available.
1350 */
1351 PNG_EXPORT(49, void, png_set_quantize, (png_structrp png_ptr,
1352 png_colorp palette, int num_palette, int maximum_colors,
1353 png_const_uint_16p histogram, int full_quantize));
1354 #endif
1355
1356 #ifdef PNG_READ_GAMMA_SUPPORTED
1357 /* The threshold on gamma processing is configurable but hard-wired into the
1358 * library. The following is the floating point variant.
1359 */
1360 #define PNG_GAMMA_THRESHOLD (PNG_GAMMA_THRESHOLD_FIXED*.00001)
1361
1362 /* Handle gamma correction. Screen_gamma=(display_exponent).
1363 * NOTE: this API simply sets the screen and file gamma values. It will
1364 * therefore override the value for gamma in a PNG file if it is called after
1365 * the file header has been read - use with care - call before reading the PNG
1366 * file for best results!
1367 *
1368 * These routines accept the same gamma values as png_set_alpha_mode (described
1369 * above). The PNG_GAMMA_ defines and PNG_DEFAULT_sRGB can be passed to either
1370 * API (floating point or fixed.) Notice, however, that the 'file_gamma' value
1371 * is the inverse of a 'screen gamma' value.
1372 */
1373 PNG_FP_EXPORT(50, void, png_set_gamma, (png_structrp png_ptr,
1374 double screen_gamma, double override_file_gamma))
1375 PNG_FIXED_EXPORT(208, void, png_set_gamma_fixed, (png_structrp png_ptr,
1376 png_fixed_point screen_gamma, png_fixed_point override_file_gamma))
1377 #endif
1378
1379 #ifdef PNG_WRITE_FLUSH_SUPPORTED
1380 /* Set how many lines between output flushes - 0 for no flushing */
1381 PNG_EXPORT(51, void, png_set_flush, (png_structrp png_ptr, int nrows));
1382 /* Flush the current PNG output buffer */
1383 PNG_EXPORT(52, void, png_write_flush, (png_structrp png_ptr));
1384 #endif
1385
1386 /* Optional update palette with requested transformations */
1387 PNG_EXPORT(53, void, png_start_read_image, (png_structrp png_ptr));
1388
1389 /* Optional call to update the users info structure */
1390 PNG_EXPORT(54, void, png_read_update_info, (png_structrp png_ptr,
1391 png_inforp info_ptr));
1392
1393 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1394 /* Read one or more rows of image data. */
1395 PNG_EXPORT(55, void, png_read_rows, (png_structrp png_ptr, png_bytepp row,
1396 png_bytepp display_row, png_uint_32 num_rows));
1397 #endif
1398
1399 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1400 /* Read a row of data. */
1401 PNG_EXPORT(56, void, png_read_row, (png_structrp png_ptr, png_bytep row,
1402 png_bytep display_row));
1403 #endif
1404
1405 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1406 /* Read the whole image into memory at once. */
1407 PNG_EXPORT(57, void, png_read_image, (png_structrp png_ptr, png_bytepp image));
1408 #endif
1409
1410 /* Write a row of image data */
1411 PNG_EXPORT(58, void, png_write_row, (png_structrp png_ptr,
1412 png_const_bytep row));
1413
1414 /* Write a few rows of image data: (*row) is not written; however, the type
1415 * is declared as writeable to maintain compatibility with previous versions
1416 * of libpng and to allow the 'display_row' array from read_rows to be passed
1417 * unchanged to write_rows.
1418 */
1419 PNG_EXPORT(59, void, png_write_rows, (png_structrp png_ptr, png_bytepp row,
1420 png_uint_32 num_rows));
1421
1422 /* Write the image data */
1423 PNG_EXPORT(60, void, png_write_image, (png_structrp png_ptr, png_bytepp image));
1424
1425 /* Write the end of the PNG file. */
1426 PNG_EXPORT(61, void, png_write_end, (png_structrp png_ptr,
1427 png_inforp info_ptr));
1428
1429 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1430 /* Read the end of the PNG file. */
1431 PNG_EXPORT(62, void, png_read_end, (png_structrp png_ptr, png_inforp info_ptr));
1432 #endif
1433
1434 /* Free any memory associated with the png_info_struct */
1435 PNG_EXPORT(63, void, png_destroy_info_struct, (png_const_structrp png_ptr,
1436 png_infopp info_ptr_ptr));
1437
1438 /* Free any memory associated with the png_struct and the png_info_structs */
1439 PNG_EXPORT(64, void, png_destroy_read_struct, (png_structpp png_ptr_ptr,
1440 png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr));
1441
1442 /* Free any memory associated with the png_struct and the png_info_structs */
1443 PNG_EXPORT(65, void, png_destroy_write_struct, (png_structpp png_ptr_ptr,
1444 png_infopp info_ptr_ptr));
1445
1446 /* Set the libpng method of handling chunk CRC errors */
1447 PNG_EXPORT(66, void, png_set_crc_action, (png_structrp png_ptr, int crit_action,
1448 int ancil_action));
1449
1450 /* Values for png_set_crc_action() say how to handle CRC errors in
1451 * ancillary and critical chunks, and whether to use the data contained
1452 * therein. Note that it is impossible to "discard" data in a critical
1453 * chunk. For versions prior to 0.90, the action was always error/quit,
1454 * whereas in version 0.90 and later, the action for CRC errors in ancillary
1455 * chunks is warn/discard. These values should NOT be changed.
1456 *
1457 * value action:critical action:ancillary
1458 */
1459 #define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */
1460 #define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */
1461 #define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */
1462 #define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */
1463 #define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */
1464 #define PNG_CRC_NO_CHANGE 5 /* use current value use current value */
1465
1466 #ifdef PNG_WRITE_SUPPORTED
1467 /* These functions give the user control over the scan-line filtering in
1468 * libpng and the compression methods used by zlib. These functions are
1469 * mainly useful for testing, as the defaults should work with most users.
1470 * Those users who are tight on memory or want faster performance at the
1471 * expense of compression can modify them. See the compression library
1472 * header file (zlib.h) for an explination of the compression functions.
1473 */
1474
1475 /* Set the filtering method(s) used by libpng. Currently, the only valid
1476 * value for "method" is 0.
1477 */
1478 PNG_EXPORT(67, void, png_set_filter, (png_structrp png_ptr, int method,
1479 int filters));
1480 #endif /* WRITE */
1481
1482 /* Flags for png_set_filter() to say which filters to use. The flags
1483 * are chosen so that they don't conflict with real filter types
1484 * below, in case they are supplied instead of the #defined constants.
1485 * These values should NOT be changed.
1486 */
1487 #define PNG_NO_FILTERS 0x00
1488 #define PNG_FILTER_NONE 0x08
1489 #define PNG_FILTER_SUB 0x10
1490 #define PNG_FILTER_UP 0x20
1491 #define PNG_FILTER_AVG 0x40
1492 #define PNG_FILTER_PAETH 0x80
1493 #define PNG_FAST_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP)
1494 #define PNG_ALL_FILTERS (PNG_FAST_FILTERS | PNG_FILTER_AVG | PNG_FILTER_PAETH)
1495
1496 /* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
1497 * These defines should NOT be changed.
1498 */
1499 #define PNG_FILTER_VALUE_NONE 0
1500 #define PNG_FILTER_VALUE_SUB 1
1501 #define PNG_FILTER_VALUE_UP 2
1502 #define PNG_FILTER_VALUE_AVG 3
1503 #define PNG_FILTER_VALUE_PAETH 4
1504 #define PNG_FILTER_VALUE_LAST 5
1505
1506 #ifdef PNG_WRITE_SUPPORTED
1507 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* DEPRECATED */
1508 PNG_FP_EXPORT(68, void, png_set_filter_heuristics, (png_structrp png_ptr,
1509 int heuristic_method, int num_weights, png_const_doublep filter_weights,
1510 png_const_doublep filter_costs))
1511 PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed,
1512 (png_structrp png_ptr, int heuristic_method, int num_weights,
1513 png_const_fixed_point_p filter_weights,
1514 png_const_fixed_point_p filter_costs))
1515 #endif /* WRITE_WEIGHTED_FILTER */
1516
1517 /* The following are no longer used and will be removed from libpng-1.7: */
1518 #define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */
1519 #define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */
1520 #define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */
1521 #define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */
1522
1523 /* Set the library compression level. Currently, valid values range from
1524 * 0 - 9, corresponding directly to the zlib compression levels 0 - 9
1525 * (0 - no compression, 9 - "maximal" compression). Note that tests have
1526 * shown that zlib compression levels 3-6 usually perform as well as level 9
1527 * for PNG images, and do considerably fewer caclulations. In the future,
1528 * these values may not correspond directly to the zlib compression levels.
1529 */
1530 #ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED
1531 PNG_EXPORT(69, void, png_set_compression_level, (png_structrp png_ptr,
1532 int level));
1533
1534 PNG_EXPORT(70, void, png_set_compression_mem_level, (png_structrp png_ptr,
1535 int mem_level));
1536
1537 PNG_EXPORT(71, void, png_set_compression_strategy, (png_structrp png_ptr,
1538 int strategy));
1539
1540 /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
1541 * smaller value of window_bits if it can do so safely.
1542 */
1543 PNG_EXPORT(72, void, png_set_compression_window_bits, (png_structrp png_ptr,
1544 int window_bits));
1545
1546 PNG_EXPORT(73, void, png_set_compression_method, (png_structrp png_ptr,
1547 int method));
1548 #endif /* WRITE_CUSTOMIZE_COMPRESSION */
1549
1550 #ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
1551 /* Also set zlib parameters for compressing non-IDAT chunks */
1552 PNG_EXPORT(222, void, png_set_text_compression_level, (png_structrp png_ptr,
1553 int level));
1554
1555 PNG_EXPORT(223, void, png_set_text_compression_mem_level, (png_structrp png_ptr,
1556 int mem_level));
1557
1558 PNG_EXPORT(224, void, png_set_text_compression_strategy, (png_structrp png_ptr,
1559 int strategy));
1560
1561 /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
1562 * smaller value of window_bits if it can do so safely.
1563 */
1564 PNG_EXPORT(225, void, png_set_text_compression_window_bits,
1565 (png_structrp png_ptr, int window_bits));
1566
1567 PNG_EXPORT(226, void, png_set_text_compression_method, (png_structrp png_ptr,
1568 int method));
1569 #endif /* WRITE_CUSTOMIZE_ZTXT_COMPRESSION */
1570 #endif /* WRITE */
1571
1572 /* These next functions are called for input/output, memory, and error
1573 * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c,
1574 * and call standard C I/O routines such as fread(), fwrite(), and
1575 * fprintf(). These functions can be made to use other I/O routines
1576 * at run time for those applications that need to handle I/O in a
1577 * different manner by calling png_set_???_fn(). See libpng-manual.txt for
1578 * more information.
1579 */
1580
1581 #ifdef PNG_STDIO_SUPPORTED
1582 /* Initialize the input/output for the PNG file to the default functions. */
1583 PNG_EXPORT(74, void, png_init_io, (png_structrp png_ptr, png_FILE_p fp));
1584 #endif
1585
1586 /* Replace the (error and abort), and warning functions with user
1587 * supplied functions. If no messages are to be printed you must still
1588 * write and use replacement functions. The replacement error_fn should
1589 * still do a longjmp to the last setjmp location if you are using this
1590 * method of error handling. If error_fn or warning_fn is NULL, the
1591 * default function will be used.
1592 */
1593
1594 PNG_EXPORT(75, void, png_set_error_fn, (png_structrp png_ptr,
1595 png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn));
1596
1597 /* Return the user pointer associated with the error functions */
1598 PNG_EXPORT(76, png_voidp, png_get_error_ptr, (png_const_structrp png_ptr));
1599
1600 /* Replace the default data output functions with a user supplied one(s).
1601 * If buffered output is not used, then output_flush_fn can be set to NULL.
1602 * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time
1603 * output_flush_fn will be ignored (and thus can be NULL).
1604 * It is probably a mistake to use NULL for output_flush_fn if
1605 * write_data_fn is not also NULL unless you have built libpng with
1606 * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's
1607 * default flush function, which uses the standard *FILE structure, will
1608 * be used.
1609 */
1610 PNG_EXPORT(77, void, png_set_write_fn, (png_structrp png_ptr, png_voidp io_ptr,
1611 png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn));
1612
1613 /* Replace the default data input function with a user supplied one. */
1614 PNG_EXPORT(78, void, png_set_read_fn, (png_structrp png_ptr, png_voidp io_ptr,
1615 png_rw_ptr read_data_fn));
1616
1617 /* Return the user pointer associated with the I/O functions */
1618 PNG_EXPORT(79, png_voidp, png_get_io_ptr, (png_const_structrp png_ptr));
1619
1620 PNG_EXPORT(80, void, png_set_read_status_fn, (png_structrp png_ptr,
1621 png_read_status_ptr read_row_fn));
1622
1623 PNG_EXPORT(81, void, png_set_write_status_fn, (png_structrp png_ptr,
1624 png_write_status_ptr write_row_fn));
1625
1626 #ifdef PNG_USER_MEM_SUPPORTED
1627 /* Replace the default memory allocation functions with user supplied one(s). */
1628 PNG_EXPORT(82, void, png_set_mem_fn, (png_structrp png_ptr, png_voidp mem_ptr,
1629 png_malloc_ptr malloc_fn, png_free_ptr free_fn));
1630 /* Return the user pointer associated with the memory functions */
1631 PNG_EXPORT(83, png_voidp, png_get_mem_ptr, (png_const_structrp png_ptr));
1632 #endif
1633
1634 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
1635 PNG_EXPORT(84, void, png_set_read_user_transform_fn, (png_structrp png_ptr,
1636 png_user_transform_ptr read_user_transform_fn));
1637 #endif
1638
1639 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
1640 PNG_EXPORT(85, void, png_set_write_user_transform_fn, (png_structrp png_ptr,
1641 png_user_transform_ptr write_user_transform_fn));
1642 #endif
1643
1644 #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
1645 PNG_EXPORT(86, void, png_set_user_transform_info, (png_structrp png_ptr,
1646 png_voidp user_transform_ptr, int user_transform_depth,
1647 int user_transform_channels));
1648 /* Return the user pointer associated with the user transform functions */
1649 PNG_EXPORT(87, png_voidp, png_get_user_transform_ptr,
1650 (png_const_structrp png_ptr));
1651 #endif
1652
1653 #ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED
1654 /* Return information about the row currently being processed. Note that these
1655 * APIs do not fail but will return unexpected results if called outside a user
1656 * transform callback. Also note that when transforming an interlaced image the
1657 * row number is the row number within the sub-image of the interlace pass, so
1658 * the value will increase to the height of the sub-image (not the full image)
1659 * then reset to 0 for the next pass.
1660 *
1661 * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
1662 * find the output pixel (x,y) given an interlaced sub-image pixel
1663 * (row,col,pass). (See below for these macros.)
1664 */
1665 PNG_EXPORT(217, png_uint_32, png_get_current_row_number, (png_const_structrp));
1666 PNG_EXPORT(218, png_byte, png_get_current_pass_number, (png_const_structrp));
1667 #endif
1668
1669 #ifdef PNG_READ_USER_CHUNKS_SUPPORTED
1670 /* This callback is called only for *unknown* chunks. If
1671 * PNG_HANDLE_AS_UNKNOWN_SUPPORTED is set then it is possible to set known
1672 * chunks to be treated as unknown, however in this case the callback must do
1673 * any processing required by the chunk (e.g. by calling the appropriate
1674 * png_set_ APIs.)
1675 *
1676 * There is no write support - on write, by default, all the chunks in the
1677 * 'unknown' list are written in the specified position.
1678 *
1679 * The integer return from the callback function is interpreted thus:
1680 *
1681 * negative: An error occurred; png_chunk_error will be called.
1682 * zero: The chunk was not handled, the chunk will be saved. A critical
1683 * chunk will cause an error at this point unless it is to be saved.
1684 * positive: The chunk was handled, libpng will ignore/discard it.
1685 *
1686 * See "INTERACTION WITH USER CHUNK CALLBACKS" below for important notes about
1687 * how this behavior will change in libpng 1.7
1688 */
1689 PNG_EXPORT(88, void, png_set_read_user_chunk_fn, (png_structrp png_ptr,
1690 png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));
1691 #endif
1692
1693 #ifdef PNG_USER_CHUNKS_SUPPORTED
1694 PNG_EXPORT(89, png_voidp, png_get_user_chunk_ptr, (png_const_structrp png_ptr));
1695 #endif
1696
1697 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1698 /* Sets the function callbacks for the push reader, and a pointer to a
1699 * user-defined structure available to the callback functions.
1700 */
1701 PNG_EXPORT(90, void, png_set_progressive_read_fn, (png_structrp png_ptr,
1702 png_voidp progressive_ptr, png_progressive_info_ptr info_fn,
1703 png_progressive_row_ptr row_fn, png_progressive_end_ptr end_fn));
1704
1705 /* Returns the user pointer associated with the push read functions */
1706 PNG_EXPORT(91, png_voidp, png_get_progressive_ptr,
1707 (png_const_structrp png_ptr));
1708
1709 /* Function to be called when data becomes available */
1710 PNG_EXPORT(92, void, png_process_data, (png_structrp png_ptr,
1711 png_inforp info_ptr, png_bytep buffer, size_t buffer_size));
1712
1713 /* A function which may be called *only* within png_process_data to stop the
1714 * processing of any more data. The function returns the number of bytes
1715 * remaining, excluding any that libpng has cached internally. A subsequent
1716 * call to png_process_data must supply these bytes again. If the argument
1717 * 'save' is set to true the routine will first save all the pending data and
1718 * will always return 0.
1719 */
1720 PNG_EXPORT(219, size_t, png_process_data_pause, (png_structrp, int save));
1721
1722 /* A function which may be called *only* outside (after) a call to
1723 * png_process_data. It returns the number of bytes of data to skip in the
1724 * input. Normally it will return 0, but if it returns a non-zero value the
1725 * application must skip than number of bytes of input data and pass the
1726 * following data to the next call to png_process_data.
1727 */
1728 PNG_EXPORT(220, png_uint_32, png_process_data_skip, (png_structrp));
1729
1730 /* Function that combines rows. 'new_row' is a flag that should come from
1731 * the callback and be non-NULL if anything needs to be done; the library
1732 * stores its own version of the new data internally and ignores the passed
1733 * in value.
1734 */
1735 PNG_EXPORT(93, void, png_progressive_combine_row, (png_const_structrp png_ptr,
1736 png_bytep old_row, png_const_bytep new_row));
1737 #endif /* PROGRESSIVE_READ */
1738
1739 PNG_EXPORTA(94, png_voidp, png_malloc, (png_const_structrp png_ptr,
1740 png_alloc_size_t size), PNG_ALLOCATED);
1741 /* Added at libpng version 1.4.0 */
1742 PNG_EXPORTA(95, png_voidp, png_calloc, (png_const_structrp png_ptr,
1743 png_alloc_size_t size), PNG_ALLOCATED);
1744
1745 /* Added at libpng version 1.2.4 */
1746 PNG_EXPORTA(96, png_voidp, png_malloc_warn, (png_const_structrp png_ptr,
1747 png_alloc_size_t size), PNG_ALLOCATED);
1748
1749 /* Frees a pointer allocated by png_malloc() */
1750 PNG_EXPORT(97, void, png_free, (png_const_structrp png_ptr, png_voidp ptr));
1751
1752 /* Free data that was allocated internally */
1753 PNG_EXPORT(98, void, png_free_data, (png_const_structrp png_ptr,
1754 png_inforp info_ptr, png_uint_32 free_me, int num));
1755
1756 /* Reassign responsibility for freeing existing data, whether allocated
1757 * by libpng or by the application; this works on the png_info structure passed
1758 * in, it does not change the state for other png_info structures.
1759 *
1760 * It is unlikely that this function works correctly as of 1.6.0 and using it
1761 * may result either in memory leaks or double free of allocated data.
1762 */
1763 PNG_EXPORT(99, void, png_data_freer, (png_const_structrp png_ptr,
1764 png_inforp info_ptr, int freer, png_uint_32 mask));
1765
1766 /* Assignments for png_data_freer */
1767 #define PNG_DESTROY_WILL_FREE_DATA 1
1768 #define PNG_SET_WILL_FREE_DATA 1
1769 #define PNG_USER_WILL_FREE_DATA 2
1770 /* Flags for png_ptr->free_me and info_ptr->free_me */
1771 #define PNG_FREE_HIST 0x0008U
1772 #define PNG_FREE_ICCP 0x0010U
1773 #define PNG_FREE_SPLT 0x0020U
1774 #define PNG_FREE_ROWS 0x0040U
1775 #define PNG_FREE_PCAL 0x0080U
1776 #define PNG_FREE_SCAL 0x0100U
1777 #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
1778 # define PNG_FREE_UNKN 0x0200U
1779 #endif
1780 /* PNG_FREE_LIST 0x0400U removed in 1.6.0 because it is ignored */
1781 #define PNG_FREE_PLTE 0x1000U
1782 #define PNG_FREE_TRNS 0x2000U
1783 #define PNG_FREE_TEXT 0x4000U
1784 #define PNG_FREE_EXIF 0x8000U /* Added at libpng-1.6.31 */
1785 #define PNG_FREE_ALL 0xffffU
1786 #define PNG_FREE_MUL 0x4220U /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */
1787
1788 #ifdef PNG_USER_MEM_SUPPORTED
1789 PNG_EXPORTA(100, png_voidp, png_malloc_default, (png_const_structrp png_ptr,
1790 png_alloc_size_t size), PNG_ALLOCATED PNG_DEPRECATED);
1791 PNG_EXPORTA(101, void, png_free_default, (png_const_structrp png_ptr,
1792 png_voidp ptr), PNG_DEPRECATED);
1793 #endif
1794
1795 #ifdef PNG_ERROR_TEXT_SUPPORTED
1796 /* Fatal error in PNG image of libpng - can't continue */
1797 PNG_EXPORTA(102, void, png_error, (png_const_structrp png_ptr,
1798 png_const_charp error_message), PNG_NORETURN);
1799
1800 /* The same, but the chunk name is prepended to the error string. */
1801 PNG_EXPORTA(103, void, png_chunk_error, (png_const_structrp png_ptr,
1802 png_const_charp error_message), PNG_NORETURN);
1803
1804 #else
1805 /* Fatal error in PNG image of libpng - can't continue */
1806 PNG_EXPORTA(104, void, png_err, (png_const_structrp png_ptr), PNG_NORETURN);
1807 # define png_error(s1,s2) png_err(s1)
1808 # define png_chunk_error(s1,s2) png_err(s1)
1809 #endif
1810
1811 #ifdef PNG_WARNINGS_SUPPORTED
1812 /* Non-fatal error in libpng. Can continue, but may have a problem. */
1813 PNG_EXPORT(105, void, png_warning, (png_const_structrp png_ptr,
1814 png_const_charp warning_message));
1815
1816 /* Non-fatal error in libpng, chunk name is prepended to message. */
1817 PNG_EXPORT(106, void, png_chunk_warning, (png_const_structrp png_ptr,
1818 png_const_charp warning_message));
1819 #else
1820 # define png_warning(s1,s2) ((void)(s1))
1821 # define png_chunk_warning(s1,s2) ((void)(s1))
1822 #endif
1823
1824 #ifdef PNG_BENIGN_ERRORS_SUPPORTED
1825 /* Benign error in libpng. Can continue, but may have a problem.
1826 * User can choose whether to handle as a fatal error or as a warning. */
1827 PNG_EXPORT(107, void, png_benign_error, (png_const_structrp png_ptr,
1828 png_const_charp warning_message));
1829
1830 #ifdef PNG_READ_SUPPORTED
1831 /* Same, chunk name is prepended to message (only during read) */
1832 PNG_EXPORT(108, void, png_chunk_benign_error, (png_const_structrp png_ptr,
1833 png_const_charp warning_message));
1834 #endif
1835
1836 PNG_EXPORT(109, void, png_set_benign_errors,
1837 (png_structrp png_ptr, int allowed));
1838 #else
1839 # ifdef PNG_ALLOW_BENIGN_ERRORS
1840 # define png_benign_error png_warning
1841 # define png_chunk_benign_error png_chunk_warning
1842 # else
1843 # define png_benign_error png_error
1844 # define png_chunk_benign_error png_chunk_error
1845 # endif
1846 #endif
1847
1848 /* The png_set_<chunk> functions are for storing values in the png_info_struct.
1849 * Similarly, the png_get_<chunk> calls are used to read values from the
1850 * png_info_struct, either storing the parameters in the passed variables, or
1851 * setting pointers into the png_info_struct where the data is stored. The
1852 * png_get_<chunk> functions return a non-zero value if the data was available
1853 * in info_ptr, or return zero and do not change any of the parameters if the
1854 * data was not available.
1855 *
1856 * These functions should be used instead of directly accessing png_info
1857 * to avoid problems with future changes in the size and internal layout of
1858 * png_info_struct.
1859 */
1860 /* Returns "flag" if chunk data is valid in info_ptr. */
1861 PNG_EXPORT(110, png_uint_32, png_get_valid, (png_const_structrp png_ptr,
1862 png_const_inforp info_ptr, png_uint_32 flag));
1863
1864 /* Returns number of bytes needed to hold a transformed row. */
1865 PNG_EXPORT(111, size_t, png_get_rowbytes, (png_const_structrp png_ptr,
1866 png_const_inforp info_ptr));
1867
1868 #ifdef PNG_INFO_IMAGE_SUPPORTED
1869 /* Returns row_pointers, which is an array of pointers to scanlines that was
1870 * returned from png_read_png().
1871 */
1872 PNG_EXPORT(112, png_bytepp, png_get_rows, (png_const_structrp png_ptr,
1873 png_const_inforp info_ptr));
1874
1875 /* Set row_pointers, which is an array of pointers to scanlines for use
1876 * by png_write_png().
1877 */
1878 PNG_EXPORT(113, void, png_set_rows, (png_const_structrp png_ptr,
1879 png_inforp info_ptr, png_bytepp row_pointers));
1880 #endif
1881
1882 /* Returns number of color channels in image. */
1883 PNG_EXPORT(114, png_byte, png_get_channels, (png_const_structrp png_ptr,
1884 png_const_inforp info_ptr));
1885
1886 #ifdef PNG_EASY_ACCESS_SUPPORTED
1887 /* Returns image width in pixels. */
1888 PNG_EXPORT(115, png_uint_32, png_get_image_width, (png_const_structrp png_ptr,
1889 png_const_inforp info_ptr));
1890
1891 /* Returns image height in pixels. */
1892 PNG_EXPORT(116, png_uint_32, png_get_image_height, (png_const_structrp png_ptr,
1893 png_const_inforp info_ptr));
1894
1895 /* Returns image bit_depth. */
1896 PNG_EXPORT(117, png_byte, png_get_bit_depth, (png_const_structrp png_ptr,
1897 png_const_inforp info_ptr));
1898
1899 /* Returns image color_type. */
1900 PNG_EXPORT(118, png_byte, png_get_color_type, (png_const_structrp png_ptr,
1901 png_const_inforp info_ptr));
1902
1903 /* Returns image filter_type. */
1904 PNG_EXPORT(119, png_byte, png_get_filter_type, (png_const_structrp png_ptr,
1905 png_const_inforp info_ptr));
1906
1907 /* Returns image interlace_type. */
1908 PNG_EXPORT(120, png_byte, png_get_interlace_type, (png_const_structrp png_ptr,
1909 png_const_inforp info_ptr));
1910
1911 /* Returns image compression_type. */
1912 PNG_EXPORT(121, png_byte, png_get_compression_type, (png_const_structrp png_ptr,
1913 png_const_inforp info_ptr));
1914
1915 /* Returns image resolution in pixels per meter, from pHYs chunk data. */
1916 PNG_EXPORT(122, png_uint_32, png_get_pixels_per_meter,
1917 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1918 PNG_EXPORT(123, png_uint_32, png_get_x_pixels_per_meter,
1919 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1920 PNG_EXPORT(124, png_uint_32, png_get_y_pixels_per_meter,
1921 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1922
1923 /* Returns pixel aspect ratio, computed from pHYs chunk data. */
1924 PNG_FP_EXPORT(125, float, png_get_pixel_aspect_ratio,
1925 (png_const_structrp png_ptr, png_const_inforp info_ptr))
1926 PNG_FIXED_EXPORT(210, png_fixed_point, png_get_pixel_aspect_ratio_fixed,
1927 (png_const_structrp png_ptr, png_const_inforp info_ptr))
1928
1929 /* Returns image x, y offset in pixels or microns, from oFFs chunk data. */
1930 PNG_EXPORT(126, png_int_32, png_get_x_offset_pixels,
1931 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1932 PNG_EXPORT(127, png_int_32, png_get_y_offset_pixels,
1933 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1934 PNG_EXPORT(128, png_int_32, png_get_x_offset_microns,
1935 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1936 PNG_EXPORT(129, png_int_32, png_get_y_offset_microns,
1937 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1938
1939 #endif /* EASY_ACCESS */
1940
1941 #ifdef PNG_READ_SUPPORTED
1942 /* Returns pointer to signature string read from PNG header */
1943 PNG_EXPORT(130, png_const_bytep, png_get_signature, (png_const_structrp png_ptr,
1944 png_const_inforp info_ptr));
1945 #endif
1946
1947 #ifdef PNG_bKGD_SUPPORTED
1948 PNG_EXPORT(131, png_uint_32, png_get_bKGD, (png_const_structrp png_ptr,
1949 png_inforp info_ptr, png_color_16p *background));
1950 #endif
1951
1952 #ifdef PNG_bKGD_SUPPORTED
1953 PNG_EXPORT(132, void, png_set_bKGD, (png_const_structrp png_ptr,
1954 png_inforp info_ptr, png_const_color_16p background));
1955 #endif
1956
1957 #ifdef PNG_cHRM_SUPPORTED
1958 PNG_FP_EXPORT(133, png_uint_32, png_get_cHRM, (png_const_structrp png_ptr,
1959 png_const_inforp info_ptr, double *white_x, double *white_y, double *red_x,
1960 double *red_y, double *green_x, double *green_y, double *blue_x,
1961 double *blue_y))
1962 PNG_FP_EXPORT(230, png_uint_32, png_get_cHRM_XYZ, (png_const_structrp png_ptr,
1963 png_const_inforp info_ptr, double *red_X, double *red_Y, double *red_Z,
1964 double *green_X, double *green_Y, double *green_Z, double *blue_X,
1965 double *blue_Y, double *blue_Z))
1966 PNG_FIXED_EXPORT(134, png_uint_32, png_get_cHRM_fixed,
1967 (png_const_structrp png_ptr, png_const_inforp info_ptr,
1968 png_fixed_point *int_white_x, png_fixed_point *int_white_y,
1969 png_fixed_point *int_red_x, png_fixed_point *int_red_y,
1970 png_fixed_point *int_green_x, png_fixed_point *int_green_y,
1971 png_fixed_point *int_blue_x, png_fixed_point *int_blue_y))
1972 PNG_FIXED_EXPORT(231, png_uint_32, png_get_cHRM_XYZ_fixed,
1973 (png_const_structrp png_ptr, png_const_inforp info_ptr,
1974 png_fixed_point *int_red_X, png_fixed_point *int_red_Y,
1975 png_fixed_point *int_red_Z, png_fixed_point *int_green_X,
1976 png_fixed_point *int_green_Y, png_fixed_point *int_green_Z,
1977 png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y,
1978 png_fixed_point *int_blue_Z))
1979 #endif
1980
1981 #ifdef PNG_cHRM_SUPPORTED
1982 PNG_FP_EXPORT(135, void, png_set_cHRM, (png_const_structrp png_ptr,
1983 png_inforp info_ptr,
1984 double white_x, double white_y, double red_x, double red_y, double green_x,
1985 double green_y, double blue_x, double blue_y))
1986 PNG_FP_EXPORT(232, void, png_set_cHRM_XYZ, (png_const_structrp png_ptr,
1987 png_inforp info_ptr, double red_X, double red_Y, double red_Z,
1988 double green_X, double green_Y, double green_Z, double blue_X,
1989 double blue_Y, double blue_Z))
1990 PNG_FIXED_EXPORT(136, void, png_set_cHRM_fixed, (png_const_structrp png_ptr,
1991 png_inforp info_ptr, png_fixed_point int_white_x,
1992 png_fixed_point int_white_y, png_fixed_point int_red_x,
1993 png_fixed_point int_red_y, png_fixed_point int_green_x,
1994 png_fixed_point int_green_y, png_fixed_point int_blue_x,
1995 png_fixed_point int_blue_y))
1996 PNG_FIXED_EXPORT(233, void, png_set_cHRM_XYZ_fixed, (png_const_structrp png_ptr,
1997 png_inforp info_ptr, png_fixed_point int_red_X, png_fixed_point int_red_Y,
1998 png_fixed_point int_red_Z, png_fixed_point int_green_X,
1999 png_fixed_point int_green_Y, png_fixed_point int_green_Z,
2000 png_fixed_point int_blue_X, png_fixed_point int_blue_Y,
2001 png_fixed_point int_blue_Z))
2002 #endif
2003
2004 #ifdef PNG_eXIf_SUPPORTED
2005 PNG_EXPORT(246, png_uint_32, png_get_eXIf, (png_const_structrp png_ptr,
2006 png_inforp info_ptr, png_bytep *exif));
2007 PNG_EXPORT(247, void, png_set_eXIf, (png_const_structrp png_ptr,
2008 png_inforp info_ptr, png_bytep exif));
2009
2010 PNG_EXPORT(248, png_uint_32, png_get_eXIf_1, (png_const_structrp png_ptr,
2011 png_const_inforp info_ptr, png_uint_32 *num_exif, png_bytep *exif));
2012 PNG_EXPORT(249, void, png_set_eXIf_1, (png_const_structrp png_ptr,
2013 png_inforp info_ptr, png_uint_32 num_exif, png_bytep exif));
2014 #endif
2015
2016 #ifdef PNG_gAMA_SUPPORTED
2017 PNG_FP_EXPORT(137, png_uint_32, png_get_gAMA, (png_const_structrp png_ptr,
2018 png_const_inforp info_ptr, double *file_gamma))
2019 PNG_FIXED_EXPORT(138, png_uint_32, png_get_gAMA_fixed,
2020 (png_const_structrp png_ptr, png_const_inforp info_ptr,
2021 png_fixed_point *int_file_gamma))
2022 #endif
2023
2024 #ifdef PNG_gAMA_SUPPORTED
2025 PNG_FP_EXPORT(139, void, png_set_gAMA, (png_const_structrp png_ptr,
2026 png_inforp info_ptr, double file_gamma))
2027 PNG_FIXED_EXPORT(140, void, png_set_gAMA_fixed, (png_const_structrp png_ptr,
2028 png_inforp info_ptr, png_fixed_point int_file_gamma))
2029 #endif
2030
2031 #ifdef PNG_hIST_SUPPORTED
2032 PNG_EXPORT(141, png_uint_32, png_get_hIST, (png_const_structrp png_ptr,
2033 png_inforp info_ptr, png_uint_16p *hist));
2034 PNG_EXPORT(142, void, png_set_hIST, (png_const_structrp png_ptr,
2035 png_inforp info_ptr, png_const_uint_16p hist));
2036 #endif
2037
2038 PNG_EXPORT(143, png_uint_32, png_get_IHDR, (png_const_structrp png_ptr,
2039 png_const_inforp info_ptr, png_uint_32 *width, png_uint_32 *height,
2040 int *bit_depth, int *color_type, int *interlace_method,
2041 int *compression_method, int *filter_method));
2042
2043 PNG_EXPORT(144, void, png_set_IHDR, (png_const_structrp png_ptr,
2044 png_inforp info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth,
2045 int color_type, int interlace_method, int compression_method,
2046 int filter_method));
2047
2048 #ifdef PNG_oFFs_SUPPORTED
2049 PNG_EXPORT(145, png_uint_32, png_get_oFFs, (png_const_structrp png_ptr,
2050 png_const_inforp info_ptr, png_int_32 *offset_x, png_int_32 *offset_y,
2051 int *unit_type));
2052 #endif
2053
2054 #ifdef PNG_oFFs_SUPPORTED
2055 PNG_EXPORT(146, void, png_set_oFFs, (png_const_structrp png_ptr,
2056 png_inforp info_ptr, png_int_32 offset_x, png_int_32 offset_y,
2057 int unit_type));
2058 #endif
2059
2060 #ifdef PNG_pCAL_SUPPORTED
2061 PNG_EXPORT(147, png_uint_32, png_get_pCAL, (png_const_structrp png_ptr,
2062 png_inforp info_ptr, png_charp *purpose, png_int_32 *X0,
2063 png_int_32 *X1, int *type, int *nparams, png_charp *units,
2064 png_charpp *params));
2065 #endif
2066
2067 #ifdef PNG_pCAL_SUPPORTED
2068 PNG_EXPORT(148, void, png_set_pCAL, (png_const_structrp png_ptr,
2069 png_inforp info_ptr, png_const_charp purpose, png_int_32 X0, png_int_32 X1,
2070 int type, int nparams, png_const_charp units, png_charpp params));
2071 #endif
2072
2073 #ifdef PNG_pHYs_SUPPORTED
2074 PNG_EXPORT(149, png_uint_32, png_get_pHYs, (png_const_structrp png_ptr,
2075 png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y,
2076 int *unit_type));
2077 #endif
2078
2079 #ifdef PNG_pHYs_SUPPORTED
2080 PNG_EXPORT(150, void, png_set_pHYs, (png_const_structrp png_ptr,
2081 png_inforp info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type));
2082 #endif
2083
2084 PNG_EXPORT(151, png_uint_32, png_get_PLTE, (png_const_structrp png_ptr,
2085 png_inforp info_ptr, png_colorp *palette, int *num_palette));
2086
2087 PNG_EXPORT(152, void, png_set_PLTE, (png_structrp png_ptr,
2088 png_inforp info_ptr, png_const_colorp palette, int num_palette));
2089
2090 #ifdef PNG_sBIT_SUPPORTED
2091 PNG_EXPORT(153, png_uint_32, png_get_sBIT, (png_const_structrp png_ptr,
2092 png_inforp info_ptr, png_color_8p *sig_bit));
2093 #endif
2094
2095 #ifdef PNG_sBIT_SUPPORTED
2096 PNG_EXPORT(154, void, png_set_sBIT, (png_const_structrp png_ptr,
2097 png_inforp info_ptr, png_const_color_8p sig_bit));
2098 #endif
2099
2100 #ifdef PNG_sRGB_SUPPORTED
2101 PNG_EXPORT(155, png_uint_32, png_get_sRGB, (png_const_structrp png_ptr,
2102 png_const_inforp info_ptr, int *file_srgb_intent));
2103 #endif
2104
2105 #ifdef PNG_sRGB_SUPPORTED
2106 PNG_EXPORT(156, void, png_set_sRGB, (png_const_structrp png_ptr,
2107 png_inforp info_ptr, int srgb_intent));
2108 PNG_EXPORT(157, void, png_set_sRGB_gAMA_and_cHRM, (png_const_structrp png_ptr,
2109 png_inforp info_ptr, int srgb_intent));
2110 #endif
2111
2112 #ifdef PNG_iCCP_SUPPORTED
2113 PNG_EXPORT(158, png_uint_32, png_get_iCCP, (png_const_structrp png_ptr,
2114 png_inforp info_ptr, png_charpp name, int *compression_type,
2115 png_bytepp profile, png_uint_32 *proflen));
2116 #endif
2117
2118 #ifdef PNG_iCCP_SUPPORTED
2119 PNG_EXPORT(159, void, png_set_iCCP, (png_const_structrp png_ptr,
2120 png_inforp info_ptr, png_const_charp name, int compression_type,
2121 png_const_bytep profile, png_uint_32 proflen));
2122 #endif
2123
2124 #ifdef PNG_sPLT_SUPPORTED
2125 PNG_EXPORT(160, int, png_get_sPLT, (png_const_structrp png_ptr,
2126 png_inforp info_ptr, png_sPLT_tpp entries));
2127 #endif
2128
2129 #ifdef PNG_sPLT_SUPPORTED
2130 PNG_EXPORT(161, void, png_set_sPLT, (png_const_structrp png_ptr,
2131 png_inforp info_ptr, png_const_sPLT_tp entries, int nentries));
2132 #endif
2133
2134 #ifdef PNG_TEXT_SUPPORTED
2135 /* png_get_text also returns the number of text chunks in *num_text */
2136 PNG_EXPORT(162, int, png_get_text, (png_const_structrp png_ptr,
2137 png_inforp info_ptr, png_textp *text_ptr, int *num_text));
2138 #endif
2139
2140 /* Note while png_set_text() will accept a structure whose text,
2141 * language, and translated keywords are NULL pointers, the structure
2142 * returned by png_get_text will always contain regular
2143 * zero-terminated C strings. They might be empty strings but
2144 * they will never be NULL pointers.
2145 */
2146
2147 #ifdef PNG_TEXT_SUPPORTED
2148 PNG_EXPORT(163, void, png_set_text, (png_const_structrp png_ptr,
2149 png_inforp info_ptr, png_const_textp text_ptr, int num_text));
2150 #endif
2151
2152 #ifdef PNG_tIME_SUPPORTED
2153 PNG_EXPORT(164, png_uint_32, png_get_tIME, (png_const_structrp png_ptr,
2154 png_inforp info_ptr, png_timep *mod_time));
2155 #endif
2156
2157 #ifdef PNG_tIME_SUPPORTED
2158 PNG_EXPORT(165, void, png_set_tIME, (png_const_structrp png_ptr,
2159 png_inforp info_ptr, png_const_timep mod_time));
2160 #endif
2161
2162 #ifdef PNG_tRNS_SUPPORTED
2163 PNG_EXPORT(166, png_uint_32, png_get_tRNS, (png_const_structrp png_ptr,
2164 png_inforp info_ptr, png_bytep *trans_alpha, int *num_trans,
2165 png_color_16p *trans_color));
2166 #endif
2167
2168 #ifdef PNG_tRNS_SUPPORTED
2169 PNG_EXPORT(167, void, png_set_tRNS, (png_structrp png_ptr,
2170 png_inforp info_ptr, png_const_bytep trans_alpha, int num_trans,
2171 png_const_color_16p trans_color));
2172 #endif
2173
2174 #ifdef PNG_sCAL_SUPPORTED
2175 PNG_FP_EXPORT(168, png_uint_32, png_get_sCAL, (png_const_structrp png_ptr,
2176 png_const_inforp info_ptr, int *unit, double *width, double *height))
2177 #if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || \
2178 defined(PNG_FLOATING_POINT_SUPPORTED)
2179 /* NOTE: this API is currently implemented using floating point arithmetic,
2180 * consequently it can only be used on systems with floating point support.
2181 * In any case the range of values supported by png_fixed_point is small and it
2182 * is highly recommended that png_get_sCAL_s be used instead.
2183 */
2184 PNG_FIXED_EXPORT(214, png_uint_32, png_get_sCAL_fixed,
2185 (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit,
2186 png_fixed_point *width, png_fixed_point *height))
2187 #endif
2188 PNG_EXPORT(169, png_uint_32, png_get_sCAL_s,
2189 (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit,
2190 png_charpp swidth, png_charpp sheight));
2191
2192 PNG_FP_EXPORT(170, void, png_set_sCAL, (png_const_structrp png_ptr,
2193 png_inforp info_ptr, int unit, double width, double height))
2194 PNG_FIXED_EXPORT(213, void, png_set_sCAL_fixed, (png_const_structrp png_ptr,
2195 png_inforp info_ptr, int unit, png_fixed_point width,
2196 png_fixed_point height))
2197 PNG_EXPORT(171, void, png_set_sCAL_s, (png_const_structrp png_ptr,
2198 png_inforp info_ptr, int unit,
2199 png_const_charp swidth, png_const_charp sheight));
2200 #endif /* sCAL */
2201
2202 #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
2203 /* Provide the default handling for all unknown chunks or, optionally, for
2204 * specific unknown chunks.
2205 *
2206 * NOTE: prior to 1.6.0 the handling specified for particular chunks on read was
2207 * ignored and the default was used, the per-chunk setting only had an effect on
2208 * write. If you wish to have chunk-specific handling on read in code that must
2209 * work on earlier versions you must use a user chunk callback to specify the
2210 * desired handling (keep or discard.)
2211 *
2212 * The 'keep' parameter is a PNG_HANDLE_CHUNK_ value as listed below. The
2213 * parameter is interpreted as follows:
2214 *
2215 * READ:
2216 * PNG_HANDLE_CHUNK_AS_DEFAULT:
2217 * Known chunks: do normal libpng processing, do not keep the chunk (but
2218 * see the comments below about PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
2219 * Unknown chunks: for a specific chunk use the global default, when used
2220 * as the default discard the chunk data.
2221 * PNG_HANDLE_CHUNK_NEVER:
2222 * Discard the chunk data.
2223 * PNG_HANDLE_CHUNK_IF_SAFE:
2224 * Keep the chunk data if the chunk is not critical else raise a chunk
2225 * error.
2226 * PNG_HANDLE_CHUNK_ALWAYS:
2227 * Keep the chunk data.
2228 *
2229 * If the chunk data is saved it can be retrieved using png_get_unknown_chunks,
2230 * below. Notice that specifying "AS_DEFAULT" as a global default is equivalent
2231 * to specifying "NEVER", however when "AS_DEFAULT" is used for specific chunks
2232 * it simply resets the behavior to the libpng default.
2233 *
2234 * INTERACTION WITH USER CHUNK CALLBACKS:
2235 * The per-chunk handling is always used when there is a png_user_chunk_ptr
2236 * callback and the callback returns 0; the chunk is then always stored *unless*
2237 * it is critical and the per-chunk setting is other than ALWAYS. Notice that
2238 * the global default is *not* used in this case. (In effect the per-chunk
2239 * value is incremented to at least IF_SAFE.)
2240 *
2241 * IMPORTANT NOTE: this behavior will change in libpng 1.7 - the global and
2242 * per-chunk defaults will be honored. If you want to preserve the current
2243 * behavior when your callback returns 0 you must set PNG_HANDLE_CHUNK_IF_SAFE
2244 * as the default - if you don't do this libpng 1.6 will issue a warning.
2245 *
2246 * If you want unhandled unknown chunks to be discarded in libpng 1.6 and
2247 * earlier simply return '1' (handled).
2248 *
2249 * PNG_HANDLE_AS_UNKNOWN_SUPPORTED:
2250 * If this is *not* set known chunks will always be handled by libpng and
2251 * will never be stored in the unknown chunk list. Known chunks listed to
2252 * png_set_keep_unknown_chunks will have no effect. If it is set then known
2253 * chunks listed with a keep other than AS_DEFAULT will *never* be processed
2254 * by libpng, in addition critical chunks must either be processed by the
2255 * callback or saved.
2256 *
2257 * The IHDR and IEND chunks must not be listed. Because this turns off the
2258 * default handling for chunks that would otherwise be recognized the
2259 * behavior of libpng transformations may well become incorrect!
2260 *
2261 * WRITE:
2262 * When writing chunks the options only apply to the chunks specified by
2263 * png_set_unknown_chunks (below), libpng will *always* write known chunks
2264 * required by png_set_ calls and will always write the core critical chunks
2265 * (as required for PLTE).
2266 *
2267 * Each chunk in the png_set_unknown_chunks list is looked up in the
2268 * png_set_keep_unknown_chunks list to find the keep setting, this is then
2269 * interpreted as follows:
2270 *
2271 * PNG_HANDLE_CHUNK_AS_DEFAULT:
2272 * Write safe-to-copy chunks and write other chunks if the global
2273 * default is set to _ALWAYS, otherwise don't write this chunk.
2274 * PNG_HANDLE_CHUNK_NEVER:
2275 * Do not write the chunk.
2276 * PNG_HANDLE_CHUNK_IF_SAFE:
2277 * Write the chunk if it is safe-to-copy, otherwise do not write it.
2278 * PNG_HANDLE_CHUNK_ALWAYS:
2279 * Write the chunk.
2280 *
2281 * Note that the default behavior is effectively the opposite of the read case -
2282 * in read unknown chunks are not stored by default, in write they are written
2283 * by default. Also the behavior of PNG_HANDLE_CHUNK_IF_SAFE is very different
2284 * - on write the safe-to-copy bit is checked, on read the critical bit is
2285 * checked and on read if the chunk is critical an error will be raised.
2286 *
2287 * num_chunks:
2288 * ===========
2289 * If num_chunks is positive, then the "keep" parameter specifies the manner
2290 * for handling only those chunks appearing in the chunk_list array,
2291 * otherwise the chunk list array is ignored.
2292 *
2293 * If num_chunks is 0 the "keep" parameter specifies the default behavior for
2294 * unknown chunks, as described above.
2295 *
2296 * If num_chunks is negative, then the "keep" parameter specifies the manner
2297 * for handling all unknown chunks plus all chunks recognized by libpng
2298 * except for the IHDR, PLTE, tRNS, IDAT, and IEND chunks (which continue to
2299 * be processed by libpng.
2300 */
2301 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
2302 PNG_EXPORT(172, void, png_set_keep_unknown_chunks, (png_structrp png_ptr,
2303 int keep, png_const_bytep chunk_list, int num_chunks));
2304 #endif /* HANDLE_AS_UNKNOWN */
2305
2306 /* The "keep" PNG_HANDLE_CHUNK_ parameter for the specified chunk is returned;
2307 * the result is therefore true (non-zero) if special handling is required,
2308 * false for the default handling.
2309 */
2310 PNG_EXPORT(173, int, png_handle_as_unknown, (png_const_structrp png_ptr,
2311 png_const_bytep chunk_name));
2312 #endif /* SET_UNKNOWN_CHUNKS */
2313
2314 #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
2315 PNG_EXPORT(174, void, png_set_unknown_chunks, (png_const_structrp png_ptr,
2316 png_inforp info_ptr, png_const_unknown_chunkp unknowns,
2317 int num_unknowns));
2318 /* NOTE: prior to 1.6.0 this routine set the 'location' field of the added
2319 * unknowns to the location currently stored in the png_struct. This is
2320 * invariably the wrong value on write. To fix this call the following API
2321 * for each chunk in the list with the correct location. If you know your
2322 * code won't be compiled on earlier versions you can rely on
2323 * png_set_unknown_chunks(write-ptr, png_get_unknown_chunks(read-ptr)) doing
2324 * the correct thing.
2325 */
2326
2327 PNG_EXPORT(175, void, png_set_unknown_chunk_location,
2328 (png_const_structrp png_ptr, png_inforp info_ptr, int chunk, int location));
2329
2330 PNG_EXPORT(176, int, png_get_unknown_chunks, (png_const_structrp png_ptr,
2331 png_inforp info_ptr, png_unknown_chunkpp entries));
2332 #endif
2333
2334 /* Png_free_data() will turn off the "valid" flag for anything it frees.
2335 * If you need to turn it off for a chunk that your application has freed,
2336 * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK);
2337 */
2338 PNG_EXPORT(177, void, png_set_invalid, (png_const_structrp png_ptr,
2339 png_inforp info_ptr, int mask));
2340
2341 #ifdef PNG_INFO_IMAGE_SUPPORTED
2342 /* The "params" pointer is currently not used and is for future expansion. */
2343 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
2344 PNG_EXPORT(178, void, png_read_png, (png_structrp png_ptr, png_inforp info_ptr,
2345 int transforms, png_voidp params));
2346 #endif
2347 #ifdef PNG_WRITE_SUPPORTED
2348 PNG_EXPORT(179, void, png_write_png, (png_structrp png_ptr, png_inforp info_ptr,
2349 int transforms, png_voidp params));
2350 #endif
2351 #endif
2352
2353 PNG_EXPORT(180, png_const_charp, png_get_copyright,
2354 (png_const_structrp png_ptr));
2355 PNG_EXPORT(181, png_const_charp, png_get_header_ver,
2356 (png_const_structrp png_ptr));
2357 PNG_EXPORT(182, png_const_charp, png_get_header_version,
2358 (png_const_structrp png_ptr));
2359 PNG_EXPORT(183, png_const_charp, png_get_libpng_ver,
2360 (png_const_structrp png_ptr));
2361
2362 #ifdef PNG_MNG_FEATURES_SUPPORTED
2363 PNG_EXPORT(184, png_uint_32, png_permit_mng_features, (png_structrp png_ptr,
2364 png_uint_32 mng_features_permitted));
2365 #endif
2366
2367 /* For use in png_set_keep_unknown, added to version 1.2.6 */
2368 #define PNG_HANDLE_CHUNK_AS_DEFAULT 0
2369 #define PNG_HANDLE_CHUNK_NEVER 1
2370 #define PNG_HANDLE_CHUNK_IF_SAFE 2
2371 #define PNG_HANDLE_CHUNK_ALWAYS 3
2372 #define PNG_HANDLE_CHUNK_LAST 4
2373
2374 /* Strip the prepended error numbers ("#nnn ") from error and warning
2375 * messages before passing them to the error or warning handler.
2376 */
2377 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
2378 PNG_EXPORT(185, void, png_set_strip_error_numbers, (png_structrp png_ptr,
2379 png_uint_32 strip_mode));
2380 #endif
2381
2382 /* Added in libpng-1.2.6 */
2383 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
2384 PNG_EXPORT(186, void, png_set_user_limits, (png_structrp png_ptr,
2385 png_uint_32 user_width_max, png_uint_32 user_height_max));
2386 PNG_EXPORT(187, png_uint_32, png_get_user_width_max,
2387 (png_const_structrp png_ptr));
2388 PNG_EXPORT(188, png_uint_32, png_get_user_height_max,
2389 (png_const_structrp png_ptr));
2390 /* Added in libpng-1.4.0 */
2391 PNG_EXPORT(189, void, png_set_chunk_cache_max, (png_structrp png_ptr,
2392 png_uint_32 user_chunk_cache_max));
2393 PNG_EXPORT(190, png_uint_32, png_get_chunk_cache_max,
2394 (png_const_structrp png_ptr));
2395 /* Added in libpng-1.4.1 */
2396 PNG_EXPORT(191, void, png_set_chunk_malloc_max, (png_structrp png_ptr,
2397 png_alloc_size_t user_chunk_cache_max));
2398 PNG_EXPORT(192, png_alloc_size_t, png_get_chunk_malloc_max,
2399 (png_const_structrp png_ptr));
2400 #endif
2401
2402 #if defined(PNG_INCH_CONVERSIONS_SUPPORTED)
2403 PNG_EXPORT(193, png_uint_32, png_get_pixels_per_inch,
2404 (png_const_structrp png_ptr, png_const_inforp info_ptr));
2405
2406 PNG_EXPORT(194, png_uint_32, png_get_x_pixels_per_inch,
2407 (png_const_structrp png_ptr, png_const_inforp info_ptr));
2408
2409 PNG_EXPORT(195, png_uint_32, png_get_y_pixels_per_inch,
2410 (png_const_structrp png_ptr, png_const_inforp info_ptr));
2411
2412 PNG_FP_EXPORT(196, float, png_get_x_offset_inches,
2413 (png_const_structrp png_ptr, png_const_inforp info_ptr))
2414 #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */
2415 PNG_FIXED_EXPORT(211, png_fixed_point, png_get_x_offset_inches_fixed,
2416 (png_const_structrp png_ptr, png_const_inforp info_ptr))
2417 #endif
2418
2419 PNG_FP_EXPORT(197, float, png_get_y_offset_inches, (png_const_structrp png_ptr,
2420 png_const_inforp info_ptr))
2421 #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */
2422 PNG_FIXED_EXPORT(212, png_fixed_point, png_get_y_offset_inches_fixed,
2423 (png_const_structrp png_ptr, png_const_inforp info_ptr))
2424 #endif
2425
2426 # ifdef PNG_pHYs_SUPPORTED
2427 PNG_EXPORT(198, png_uint_32, png_get_pHYs_dpi, (png_const_structrp png_ptr,
2428 png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y,
2429 int *unit_type));
2430 # endif /* pHYs */
2431 #endif /* INCH_CONVERSIONS */
2432
2433 /* Added in libpng-1.4.0 */
2434 #ifdef PNG_IO_STATE_SUPPORTED
2435 PNG_EXPORT(199, png_uint_32, png_get_io_state, (png_const_structrp png_ptr));
2436
2437 /* Removed from libpng 1.6; use png_get_io_chunk_type. */
2438 PNG_REMOVED(200, png_const_bytep, png_get_io_chunk_name, (png_structrp png_ptr),
2439 PNG_DEPRECATED)
2440
2441 PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type,
2442 (png_const_structrp png_ptr));
2443
2444 /* The flags returned by png_get_io_state() are the following: */
2445 # define PNG_IO_NONE 0x0000 /* no I/O at this moment */
2446 # define PNG_IO_READING 0x0001 /* currently reading */
2447 # define PNG_IO_WRITING 0x0002 /* currently writing */
2448 # define PNG_IO_SIGNATURE 0x0010 /* currently at the file signature */
2449 # define PNG_IO_CHUNK_HDR 0x0020 /* currently at the chunk header */
2450 # define PNG_IO_CHUNK_DATA 0x0040 /* currently at the chunk data */
2451 # define PNG_IO_CHUNK_CRC 0x0080 /* currently at the chunk crc */
2452 # define PNG_IO_MASK_OP 0x000f /* current operation: reading/writing */
2453 # define PNG_IO_MASK_LOC 0x00f0 /* current location: sig/hdr/data/crc */
2454 #endif /* IO_STATE */
2455
2456 /* Interlace support. The following macros are always defined so that if
2457 * libpng interlace handling is turned off the macros may be used to handle
2458 * interlaced images within the application.
2459 */
2460 #define PNG_INTERLACE_ADAM7_PASSES 7
2461
2462 /* Two macros to return the first row and first column of the original,
2463 * full, image which appears in a given pass. 'pass' is in the range 0
2464 * to 6 and the result is in the range 0 to 7.
2465 */
2466 #define PNG_PASS_START_ROW(pass) (((1&~(pass))<<(3-((pass)>>1)))&7)
2467 #define PNG_PASS_START_COL(pass) (((1& (pass))<<(3-(((pass)+1)>>1)))&7)
2468
2469 /* A macro to return the offset between pixels in the output row for a pair of
2470 * pixels in the input - effectively the inverse of the 'COL_SHIFT' macro that
2471 * follows. Note that ROW_OFFSET is the offset from one row to the next whereas
2472 * COL_OFFSET is from one column to the next, within a row.
2473 */
2474 #define PNG_PASS_ROW_OFFSET(pass) ((pass)>2?(8>>(((pass)-1)>>1)):8)
2475 #define PNG_PASS_COL_OFFSET(pass) (1<<((7-(pass))>>1))
2476
2477 /* Two macros to help evaluate the number of rows or columns in each
2478 * pass. This is expressed as a shift - effectively log2 of the number or
2479 * rows or columns in each 8x8 tile of the original image.
2480 */
2481 #define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3)
2482 #define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3)
2483
2484 /* Hence two macros to determine the number of rows or columns in a given
2485 * pass of an image given its height or width. In fact these macros may
2486 * return non-zero even though the sub-image is empty, because the other
2487 * dimension may be empty for a small image.
2488 */
2489 #define PNG_PASS_ROWS(height, pass) (((height)+(((1<<PNG_PASS_ROW_SHIFT(pass))\
2490 -1)-PNG_PASS_START_ROW(pass)))>>PNG_PASS_ROW_SHIFT(pass))
2491 #define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\
2492 -1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass))
2493
2494 /* For the reader row callbacks (both progressive and sequential) it is
2495 * necessary to find the row in the output image given a row in an interlaced
2496 * image, so two more macros:
2497 */
2498 #define PNG_ROW_FROM_PASS_ROW(y_in, pass) \
2499 (((y_in)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass))
2500 #define PNG_COL_FROM_PASS_COL(x_in, pass) \
2501 (((x_in)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass))
2502
2503 /* Two macros which return a boolean (0 or 1) saying whether the given row
2504 * or column is in a particular pass. These use a common utility macro that
2505 * returns a mask for a given pass - the offset 'off' selects the row or
2506 * column version. The mask has the appropriate bit set for each column in
2507 * the tile.
2508 */
2509 #define PNG_PASS_MASK(pass,off) ( \
2510 ((0x110145AF>>(((7-(off))-(pass))<<2)) & 0xF) | \
2511 ((0x01145AF0>>(((7-(off))-(pass))<<2)) & 0xF0))
2512
2513 #define PNG_ROW_IN_INTERLACE_PASS(y, pass) \
2514 ((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1)
2515 #define PNG_COL_IN_INTERLACE_PASS(x, pass) \
2516 ((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1)
2517
2518 #ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
2519 /* With these routines we avoid an integer divide, which will be slower on
2520 * most machines. However, it does take more operations than the corresponding
2521 * divide method, so it may be slower on a few RISC systems. There are two
2522 * shifts (by 8 or 16 bits) and an addition, versus a single integer divide.
2523 *
2524 * Note that the rounding factors are NOT supposed to be the same! 128 and
2525 * 32768 are correct for the NODIV code; 127 and 32767 are correct for the
2526 * standard method.
2527 *
2528 * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
2529 */
2530
2531 /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */
2532
2533 # define png_composite(composite, fg, alpha, bg) \
2534 { \
2535 png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \
2536 * (png_uint_16)(alpha) \
2537 + (png_uint_16)(bg)*(png_uint_16)(255 \
2538 - (png_uint_16)(alpha)) + 128); \
2539 (composite) = (png_byte)(((temp + (temp >> 8)) >> 8) & 0xff); \
2540 }
2541
2542 # define png_composite_16(composite, fg, alpha, bg) \
2543 { \
2544 png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) \
2545 * (png_uint_32)(alpha) \
2546 + (png_uint_32)(bg)*(65535 \
2547 - (png_uint_32)(alpha)) + 32768); \
2548 (composite) = (png_uint_16)(0xffff & ((temp + (temp >> 16)) >> 16)); \
2549 }
2550
2551 #else /* Standard method using integer division */
2552
2553 # define png_composite(composite, fg, alpha, bg) \
2554 (composite) = \
2555 (png_byte)(0xff & (((png_uint_16)(fg) * (png_uint_16)(alpha) + \
2556 (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \
2557 127) / 255))
2558
2559 # define png_composite_16(composite, fg, alpha, bg) \
2560 (composite) = \
2561 (png_uint_16)(0xffff & (((png_uint_32)(fg) * (png_uint_32)(alpha) + \
2562 (png_uint_32)(bg)*(png_uint_32)(65535 - (png_uint_32)(alpha)) + \
2563 32767) / 65535))
2564 #endif /* READ_COMPOSITE_NODIV */
2565
2566 #ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED
2567 PNG_EXPORT(201, png_uint_32, png_get_uint_32, (png_const_bytep buf));
2568 PNG_EXPORT(202, png_uint_16, png_get_uint_16, (png_const_bytep buf));
2569 PNG_EXPORT(203, png_int_32, png_get_int_32, (png_const_bytep buf));
2570 #endif
2571
2572 PNG_EXPORT(204, png_uint_32, png_get_uint_31, (png_const_structrp png_ptr,
2573 png_const_bytep buf));
2574 /* No png_get_int_16 -- may be added if there's a real need for it. */
2575
2576 /* Place a 32-bit number into a buffer in PNG byte order (big-endian). */
2577 #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
2578 PNG_EXPORT(205, void, png_save_uint_32, (png_bytep buf, png_uint_32 i));
2579 #endif
2580 #ifdef PNG_SAVE_INT_32_SUPPORTED
2581 PNG_EXPORT(206, void, png_save_int_32, (png_bytep buf, png_int_32 i));
2582 #endif
2583
2584 /* Place a 16-bit number into a buffer in PNG byte order.
2585 * The parameter is declared unsigned int, not png_uint_16,
2586 * just to avoid potential problems on pre-ANSI C compilers.
2587 */
2588 #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
2589 PNG_EXPORT(207, void, png_save_uint_16, (png_bytep buf, unsigned int i));
2590 /* No png_save_int_16 -- may be added if there's a real need for it. */
2591 #endif
2592
2593 #ifdef PNG_USE_READ_MACROS
2594 /* Inline macros to do direct reads of bytes from the input buffer.
2595 * The png_get_int_32() routine assumes we are using two's complement
2596 * format for negative values, which is almost certainly true.
2597 */
2598 # define PNG_get_uint_32(buf) \
2599 (((png_uint_32)(*(buf)) << 24) + \
2600 ((png_uint_32)(*((buf) + 1)) << 16) + \
2601 ((png_uint_32)(*((buf) + 2)) << 8) + \
2602 ((png_uint_32)(*((buf) + 3))))
2603
2604 /* From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the
2605 * function) incorrectly returned a value of type png_uint_32.
2606 */
2607 # define PNG_get_uint_16(buf) \
2608 ((png_uint_16) \
2609 (((unsigned int)(*(buf)) << 8) + \
2610 ((unsigned int)(*((buf) + 1)))))
2611
2612 # define PNG_get_int_32(buf) \
2613 ((png_int_32)((*(buf) & 0x80) \
2614 ? -((png_int_32)(((png_get_uint_32(buf)^0xffffffffU)+1U)&0x7fffffffU)) \
2615 : (png_int_32)png_get_uint_32(buf)))
2616
2617 /* If PNG_PREFIX is defined the same thing as below happens in pnglibconf.h,
2618 * but defining a macro name prefixed with PNG_PREFIX.
2619 */
2620 # ifndef PNG_PREFIX
2621 # define png_get_uint_32(buf) PNG_get_uint_32(buf)
2622 # define png_get_uint_16(buf) PNG_get_uint_16(buf)
2623 # define png_get_int_32(buf) PNG_get_int_32(buf)
2624 # endif
2625 #else
2626 # ifdef PNG_PREFIX
2627 /* No macros; revert to the (redefined) function */
2628 # define PNG_get_uint_32 (png_get_uint_32)
2629 # define PNG_get_uint_16 (png_get_uint_16)
2630 # define PNG_get_int_32 (png_get_int_32)
2631 # endif
2632 #endif
2633
2634 #ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
2635 PNG_EXPORT(242, void, png_set_check_for_invalid_index,
2636 (png_structrp png_ptr, int allowed));
2637 # ifdef PNG_GET_PALETTE_MAX_SUPPORTED
2638 PNG_EXPORT(243, int, png_get_palette_max, (png_const_structp png_ptr,
2639 png_const_infop info_ptr));
2640 # endif
2641 #endif /* CHECK_FOR_INVALID_INDEX */
2642
2643 /*******************************************************************************
2644 * Section 5: SIMPLIFIED API
2645 *******************************************************************************
2646 *
2647 * Please read the documentation in libpng-manual.txt (TODO: write said
2648 * documentation) if you don't understand what follows.
2649 *
2650 * The simplified API hides the details of both libpng and the PNG file format
2651 * itself. It allows PNG files to be read into a very limited number of
2652 * in-memory bitmap formats or to be written from the same formats. If these
2653 * formats do not accommodate your needs then you can, and should, use the more
2654 * sophisticated APIs above - these support a wide variety of in-memory formats
2655 * and a wide variety of sophisticated transformations to those formats as well
2656 * as a wide variety of APIs to manipulate ancillary information.
2657 *
2658 * To read a PNG file using the simplified API:
2659 *
2660 * 1) Declare a 'png_image' structure (see below) on the stack, set the
2661 * version field to PNG_IMAGE_VERSION and the 'opaque' pointer to NULL
2662 * (this is REQUIRED, your program may crash if you don't do it.)
2663 * 2) Call the appropriate png_image_begin_read... function.
2664 * 3) Set the png_image 'format' member to the required sample format.
2665 * 4) Allocate a buffer for the image and, if required, the color-map.
2666 * 5) Call png_image_finish_read to read the image and, if required, the
2667 * color-map into your buffers.
2668 *
2669 * There are no restrictions on the format of the PNG input itself; all valid
2670 * color types, bit depths, and interlace methods are acceptable, and the
2671 * input image is transformed as necessary to the requested in-memory format
2672 * during the png_image_finish_read() step. The only caveat is that if you
2673 * request a color-mapped image from a PNG that is full-color or makes
2674 * complex use of an alpha channel the transformation is extremely lossy and the
2675 * result may look terrible.
2676 *
2677 * To write a PNG file using the simplified API:
2678 *
2679 * 1) Declare a 'png_image' structure on the stack and memset() it to all zero.
2680 * 2) Initialize the members of the structure that describe the image, setting
2681 * the 'format' member to the format of the image samples.
2682 * 3) Call the appropriate png_image_write... function with a pointer to the
2683 * image and, if necessary, the color-map to write the PNG data.
2684 *
2685 * png_image is a structure that describes the in-memory format of an image
2686 * when it is being read or defines the in-memory format of an image that you
2687 * need to write:
2688 */
2689 #if defined(PNG_SIMPLIFIED_READ_SUPPORTED) || \
2690 defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
2691
2692 #define PNG_IMAGE_VERSION 1
2693
2694 typedef struct png_control *png_controlp;
2695 typedef struct
2696 {
2697 png_controlp opaque; /* Initialize to NULL, free with png_image_free */
2698 png_uint_32 version; /* Set to PNG_IMAGE_VERSION */
2699 png_uint_32 width; /* Image width in pixels (columns) */
2700 png_uint_32 height; /* Image height in pixels (rows) */
2701 png_uint_32 format; /* Image format as defined below */
2702 png_uint_32 flags; /* A bit mask containing informational flags */
2703 png_uint_32 colormap_entries;
2704 /* Number of entries in the color-map */
2705
2706 /* In the event of an error or warning the following field will be set to a
2707 * non-zero value and the 'message' field will contain a '\0' terminated
2708 * string with the libpng error or warning message. If both warnings and
2709 * an error were encountered, only the error is recorded. If there
2710 * are multiple warnings, only the first one is recorded.
2711 *
2712 * The upper 30 bits of this value are reserved, the low two bits contain
2713 * a value as follows:
2714 */
2715 # define PNG_IMAGE_WARNING 1
2716 # define PNG_IMAGE_ERROR 2
2717 /*
2718 * The result is a two-bit code such that a value more than 1 indicates
2719 * a failure in the API just called:
2720 *
2721 * 0 - no warning or error
2722 * 1 - warning
2723 * 2 - error
2724 * 3 - error preceded by warning
2725 */
2726 # define PNG_IMAGE_FAILED(png_cntrl) ((((png_cntrl).warning_or_error)&0x03)>1)
2727
2728 png_uint_32 warning_or_error;
2729
2730 char message[64];
2731 } png_image, *png_imagep;
2732
2733 /* The samples of the image have one to four channels whose components have
2734 * original values in the range 0 to 1.0:
2735 *
2736 * 1: A single gray or luminance channel (G).
2737 * 2: A gray/luminance channel and an alpha channel (GA).
2738 * 3: Three red, green, blue color channels (RGB).
2739 * 4: Three color channels and an alpha channel (RGBA).
2740 *
2741 * The components are encoded in one of two ways:
2742 *
2743 * a) As a small integer, value 0..255, contained in a single byte. For the
2744 * alpha channel the original value is simply value/255. For the color or
2745 * luminance channels the value is encoded according to the sRGB specification
2746 * and matches the 8-bit format expected by typical display devices.
2747 *
2748 * The color/gray channels are not scaled (pre-multiplied) by the alpha
2749 * channel and are suitable for passing to color management software.
2750 *
2751 * b) As a value in the range 0..65535, contained in a 2-byte integer. All
2752 * channels can be converted to the original value by dividing by 65535; all
2753 * channels are linear. Color channels use the RGB encoding (RGB end-points) of
2754 * the sRGB specification. This encoding is identified by the
2755 * PNG_FORMAT_FLAG_LINEAR flag below.
2756 *
2757 * When the simplified API needs to convert between sRGB and linear colorspaces,
2758 * the actual sRGB transfer curve defined in the sRGB specification (see the
2759 * article at <https://en.wikipedia.org/wiki/SRGB>) is used, not the gamma=1/2.2
2760 * approximation used elsewhere in libpng.
2761 *
2762 * When an alpha channel is present it is expected to denote pixel coverage
2763 * of the color or luminance channels and is returned as an associated alpha
2764 * channel: the color/gray channels are scaled (pre-multiplied) by the alpha
2765 * value.
2766 *
2767 * The samples are either contained directly in the image data, between 1 and 8
2768 * bytes per pixel according to the encoding, or are held in a color-map indexed
2769 * by bytes in the image data. In the case of a color-map the color-map entries
2770 * are individual samples, encoded as above, and the image data has one byte per
2771 * pixel to select the relevant sample from the color-map.
2772 */
2773
2774 /* PNG_FORMAT_*
2775 *
2776 * #defines to be used in png_image::format. Each #define identifies a
2777 * particular layout of sample data and, if present, alpha values. There are
2778 * separate defines for each of the two component encodings.
2779 *
2780 * A format is built up using single bit flag values. All combinations are
2781 * valid. Formats can be built up from the flag values or you can use one of
2782 * the predefined values below. When testing formats always use the FORMAT_FLAG
2783 * macros to test for individual features - future versions of the library may
2784 * add new flags.
2785 *
2786 * When reading or writing color-mapped images the format should be set to the
2787 * format of the entries in the color-map then png_image_{read,write}_colormap
2788 * called to read or write the color-map and set the format correctly for the
2789 * image data. Do not set the PNG_FORMAT_FLAG_COLORMAP bit directly!
2790 *
2791 * NOTE: libpng can be built with particular features disabled. If you see
2792 * compiler errors because the definition of one of the following flags has been
2793 * compiled out it is because libpng does not have the required support. It is
2794 * possible, however, for the libpng configuration to enable the format on just
2795 * read or just write; in that case you may see an error at run time. You can
2796 * guard against this by checking for the definition of the appropriate
2797 * "_SUPPORTED" macro, one of:
2798 *
2799 * PNG_SIMPLIFIED_{READ,WRITE}_{BGR,AFIRST}_SUPPORTED
2800 */
2801 #define PNG_FORMAT_FLAG_ALPHA 0x01U /* format with an alpha channel */
2802 #define PNG_FORMAT_FLAG_COLOR 0x02U /* color format: otherwise grayscale */
2803 #define PNG_FORMAT_FLAG_LINEAR 0x04U /* 2-byte channels else 1-byte */
2804 #define PNG_FORMAT_FLAG_COLORMAP 0x08U /* image data is color-mapped */
2805
2806 #ifdef PNG_FORMAT_BGR_SUPPORTED
2807 # define PNG_FORMAT_FLAG_BGR 0x10U /* BGR colors, else order is RGB */
2808 #endif
2809
2810 #ifdef PNG_FORMAT_AFIRST_SUPPORTED
2811 # define PNG_FORMAT_FLAG_AFIRST 0x20U /* alpha channel comes first */
2812 #endif
2813
2814 #define PNG_FORMAT_FLAG_ASSOCIATED_ALPHA 0x40U /* alpha channel is associated */
2815
2816 /* Commonly used formats have predefined macros.
2817 *
2818 * First the single byte (sRGB) formats:
2819 */
2820 #define PNG_FORMAT_GRAY 0
2821 #define PNG_FORMAT_GA PNG_FORMAT_FLAG_ALPHA
2822 #define PNG_FORMAT_AG (PNG_FORMAT_GA|PNG_FORMAT_FLAG_AFIRST)
2823 #define PNG_FORMAT_RGB PNG_FORMAT_FLAG_COLOR
2824 #define PNG_FORMAT_BGR (PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_BGR)
2825 #define PNG_FORMAT_RGBA (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_ALPHA)
2826 #define PNG_FORMAT_ARGB (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_AFIRST)
2827 #define PNG_FORMAT_BGRA (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_ALPHA)
2828 #define PNG_FORMAT_ABGR (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_AFIRST)
2829
2830 /* Then the linear 2-byte formats. When naming these "Y" is used to
2831 * indicate a luminance (gray) channel.
2832 */
2833 #define PNG_FORMAT_LINEAR_Y PNG_FORMAT_FLAG_LINEAR
2834 #define PNG_FORMAT_LINEAR_Y_ALPHA (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_ALPHA)
2835 #define PNG_FORMAT_LINEAR_RGB (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR)
2836 #define PNG_FORMAT_LINEAR_RGB_ALPHA \
2837 (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA)
2838
2839 /* With color-mapped formats the image data is one byte for each pixel, the byte
2840 * is an index into the color-map which is formatted as above. To obtain a
2841 * color-mapped format it is sufficient just to add the PNG_FOMAT_FLAG_COLORMAP
2842 * to one of the above definitions, or you can use one of the definitions below.
2843 */
2844 #define PNG_FORMAT_RGB_COLORMAP (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_COLORMAP)
2845 #define PNG_FORMAT_BGR_COLORMAP (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_COLORMAP)
2846 #define PNG_FORMAT_RGBA_COLORMAP (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_COLORMAP)
2847 #define PNG_FORMAT_ARGB_COLORMAP (PNG_FORMAT_ARGB|PNG_FORMAT_FLAG_COLORMAP)
2848 #define PNG_FORMAT_BGRA_COLORMAP (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_COLORMAP)
2849 #define PNG_FORMAT_ABGR_COLORMAP (PNG_FORMAT_ABGR|PNG_FORMAT_FLAG_COLORMAP)
2850
2851 /* PNG_IMAGE macros
2852 *
2853 * These are convenience macros to derive information from a png_image
2854 * structure. The PNG_IMAGE_SAMPLE_ macros return values appropriate to the
2855 * actual image sample values - either the entries in the color-map or the
2856 * pixels in the image. The PNG_IMAGE_PIXEL_ macros return corresponding values
2857 * for the pixels and will always return 1 for color-mapped formats. The
2858 * remaining macros return information about the rows in the image and the
2859 * complete image.
2860 *
2861 * NOTE: All the macros that take a png_image::format parameter are compile time
2862 * constants if the format parameter is, itself, a constant. Therefore these
2863 * macros can be used in array declarations and case labels where required.
2864 * Similarly the macros are also pre-processor constants (sizeof is not used) so
2865 * they can be used in #if tests.
2866 *
2867 * First the information about the samples.
2868 */
2869 #define PNG_IMAGE_SAMPLE_CHANNELS(fmt)\
2870 (((fmt)&(PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA))+1)
2871 /* Return the total number of channels in a given format: 1..4 */
2872
2873 #define PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)\
2874 ((((fmt) & PNG_FORMAT_FLAG_LINEAR) >> 2)+1)
2875 /* Return the size in bytes of a single component of a pixel or color-map
2876 * entry (as appropriate) in the image: 1 or 2.
2877 */
2878
2879 #define PNG_IMAGE_SAMPLE_SIZE(fmt)\
2880 (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt))
2881 /* This is the size of the sample data for one sample. If the image is
2882 * color-mapped it is the size of one color-map entry (and image pixels are
2883 * one byte in size), otherwise it is the size of one image pixel.
2884 */
2885
2886 #define PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(fmt)\
2887 (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * 256)
2888 /* The maximum size of the color-map required by the format expressed in a
2889 * count of components. This can be used to compile-time allocate a
2890 * color-map:
2891 *
2892 * png_uint_16 colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(linear_fmt)];
2893 *
2894 * png_byte colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(sRGB_fmt)];
2895 *
2896 * Alternatively use the PNG_IMAGE_COLORMAP_SIZE macro below to use the
2897 * information from one of the png_image_begin_read_ APIs and dynamically
2898 * allocate the required memory.
2899 */
2900
2901 /* Corresponding information about the pixels */
2902 #define PNG_IMAGE_PIXEL_(test,fmt)\
2903 (((fmt)&PNG_FORMAT_FLAG_COLORMAP)?1:test(fmt))
2904
2905 #define PNG_IMAGE_PIXEL_CHANNELS(fmt)\
2906 PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_CHANNELS,fmt)
2907 /* The number of separate channels (components) in a pixel; 1 for a
2908 * color-mapped image.
2909 */
2910
2911 #define PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt)\
2912 PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_COMPONENT_SIZE,fmt)
2913 /* The size, in bytes, of each component in a pixel; 1 for a color-mapped
2914 * image.
2915 */
2916
2917 #define PNG_IMAGE_PIXEL_SIZE(fmt) PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_SIZE,fmt)
2918 /* The size, in bytes, of a complete pixel; 1 for a color-mapped image. */
2919
2920 /* Information about the whole row, or whole image */
2921 #define PNG_IMAGE_ROW_STRIDE(image)\
2922 (PNG_IMAGE_PIXEL_CHANNELS((image).format) * (image).width)
2923 /* Return the total number of components in a single row of the image; this
2924 * is the minimum 'row stride', the minimum count of components between each
2925 * row. For a color-mapped image this is the minimum number of bytes in a
2926 * row.
2927 *
2928 * WARNING: this macro overflows for some images with more than one component
2929 * and very large image widths. libpng will refuse to process an image where
2930 * this macro would overflow.
2931 */
2932
2933 #define PNG_IMAGE_BUFFER_SIZE(image, row_stride)\
2934 (PNG_IMAGE_PIXEL_COMPONENT_SIZE((image).format)*(image).height*(row_stride))
2935 /* Return the size, in bytes, of an image buffer given a png_image and a row
2936 * stride - the number of components to leave space for in each row.
2937 *
2938 * WARNING: this macro overflows a 32-bit integer for some large PNG images,
2939 * libpng will refuse to process an image where such an overflow would occur.
2940 */
2941
2942 #define PNG_IMAGE_SIZE(image)\
2943 PNG_IMAGE_BUFFER_SIZE(image, PNG_IMAGE_ROW_STRIDE(image))
2944 /* Return the size, in bytes, of the image in memory given just a png_image;
2945 * the row stride is the minimum stride required for the image.
2946 */
2947
2948 #define PNG_IMAGE_COLORMAP_SIZE(image)\
2949 (PNG_IMAGE_SAMPLE_SIZE((image).format) * (image).colormap_entries)
2950 /* Return the size, in bytes, of the color-map of this image. If the image
2951 * format is not a color-map format this will return a size sufficient for
2952 * 256 entries in the given format; check PNG_FORMAT_FLAG_COLORMAP if
2953 * you don't want to allocate a color-map in this case.
2954 */
2955
2956 /* PNG_IMAGE_FLAG_*
2957 *
2958 * Flags containing additional information about the image are held in the
2959 * 'flags' field of png_image.
2960 */
2961 #define PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB 0x01
2962 /* This indicates that the RGB values of the in-memory bitmap do not
2963 * correspond to the red, green and blue end-points defined by sRGB.
2964 */
2965
2966 #define PNG_IMAGE_FLAG_FAST 0x02
2967 /* On write emphasise speed over compression; the resultant PNG file will be
2968 * larger but will be produced significantly faster, particular for large
2969 * images. Do not use this option for images which will be distributed, only
2970 * used it when producing intermediate files that will be read back in
2971 * repeatedly. For a typical 24-bit image the option will double the read
2972 * speed at the cost of increasing the image size by 25%, however for many
2973 * more compressible images the PNG file can be 10 times larger with only a
2974 * slight speed gain.
2975 */
2976
2977 #define PNG_IMAGE_FLAG_16BIT_sRGB 0x04
2978 /* On read if the image is a 16-bit per component image and there is no gAMA
2979 * or sRGB chunk assume that the components are sRGB encoded. Notice that
2980 * images output by the simplified API always have gamma information; setting
2981 * this flag only affects the interpretation of 16-bit images from an
2982 * external source. It is recommended that the application expose this flag
2983 * to the user; the user can normally easily recognize the difference between
2984 * linear and sRGB encoding. This flag has no effect on write - the data
2985 * passed to the write APIs must have the correct encoding (as defined
2986 * above.)
2987 *
2988 * If the flag is not set (the default) input 16-bit per component data is
2989 * assumed to be linear.
2990 *
2991 * NOTE: the flag can only be set after the png_image_begin_read_ call,
2992 * because that call initializes the 'flags' field.
2993 */
2994
2995 #ifdef PNG_SIMPLIFIED_READ_SUPPORTED
2996 /* READ APIs
2997 * ---------
2998 *
2999 * The png_image passed to the read APIs must have been initialized by setting
3000 * the png_controlp field 'opaque' to NULL (or, safer, memset the whole thing.)
3001 */
3002 #ifdef PNG_STDIO_SUPPORTED
3003 PNG_EXPORT(234, int, png_image_begin_read_from_file, (png_imagep image,
3004 const char *file_name));
3005 /* The named file is opened for read and the image header is filled in
3006 * from the PNG header in the file.
3007 */
3008
3009 PNG_EXPORT(235, int, png_image_begin_read_from_stdio, (png_imagep image,
3010 FILE* file));
3011 /* The PNG header is read from the stdio FILE object. */
3012 #endif /* STDIO */
3013
3014 PNG_EXPORT(236, int, png_image_begin_read_from_memory, (png_imagep image,
3015 png_const_voidp memory, size_t size));
3016 /* The PNG header is read from the given memory buffer. */
3017
3018 PNG_EXPORT(237, int, png_image_finish_read, (png_imagep image,
3019 png_const_colorp background, void *buffer, png_int_32 row_stride,
3020 void *colormap));
3021 /* Finish reading the image into the supplied buffer and clean up the
3022 * png_image structure.
3023 *
3024 * row_stride is the step, in byte or 2-byte units as appropriate,
3025 * between adjacent rows. A positive stride indicates that the top-most row
3026 * is first in the buffer - the normal top-down arrangement. A negative
3027 * stride indicates that the bottom-most row is first in the buffer.
3028 *
3029 * background need only be supplied if an alpha channel must be removed from
3030 * a png_byte format and the removal is to be done by compositing on a solid
3031 * color; otherwise it may be NULL and any composition will be done directly
3032 * onto the buffer. The value is an sRGB color to use for the background,
3033 * for grayscale output the green channel is used.
3034 *
3035 * background must be supplied when an alpha channel must be removed from a
3036 * single byte color-mapped output format, in other words if:
3037 *
3038 * 1) The original format from png_image_begin_read_from_* had
3039 * PNG_FORMAT_FLAG_ALPHA set.
3040 * 2) The format set by the application does not.
3041 * 3) The format set by the application has PNG_FORMAT_FLAG_COLORMAP set and
3042 * PNG_FORMAT_FLAG_LINEAR *not* set.
3043 *
3044 * For linear output removing the alpha channel is always done by compositing
3045 * on black and background is ignored.
3046 *
3047 * colormap must be supplied when PNG_FORMAT_FLAG_COLORMAP is set. It must
3048 * be at least the size (in bytes) returned by PNG_IMAGE_COLORMAP_SIZE.
3049 * image->colormap_entries will be updated to the actual number of entries
3050 * written to the colormap; this may be less than the original value.
3051 */
3052
3053 PNG_EXPORT(238, void, png_image_free, (png_imagep image));
3054 /* Free any data allocated by libpng in image->opaque, setting the pointer to
3055 * NULL. May be called at any time after the structure is initialized.
3056 */
3057 #endif /* SIMPLIFIED_READ */
3058
3059 #ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED
3060 /* WRITE APIS
3061 * ----------
3062 * For write you must initialize a png_image structure to describe the image to
3063 * be written. To do this use memset to set the whole structure to 0 then
3064 * initialize fields describing your image.
3065 *
3066 * version: must be set to PNG_IMAGE_VERSION
3067 * opaque: must be initialized to NULL
3068 * width: image width in pixels
3069 * height: image height in rows
3070 * format: the format of the data (image and color-map) you wish to write
3071 * flags: set to 0 unless one of the defined flags applies; set
3072 * PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB for color format images where the RGB
3073 * values do not correspond to the colors in sRGB.
3074 * colormap_entries: set to the number of entries in the color-map (0 to 256)
3075 */
3076 #ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED
3077 PNG_EXPORT(239, int, png_image_write_to_file, (png_imagep image,
3078 const char *file, int convert_to_8bit, const void *buffer,
3079 png_int_32 row_stride, const void *colormap));
3080 /* Write the image to the named file. */
3081
3082 PNG_EXPORT(240, int, png_image_write_to_stdio, (png_imagep image, FILE *file,
3083 int convert_to_8_bit, const void *buffer, png_int_32 row_stride,
3084 const void *colormap));
3085 /* Write the image to the given (FILE*). */
3086 #endif /* SIMPLIFIED_WRITE_STDIO */
3087
3088 /* With all write APIs if image is in one of the linear formats with 16-bit
3089 * data then setting convert_to_8_bit will cause the output to be an 8-bit PNG
3090 * gamma encoded according to the sRGB specification, otherwise a 16-bit linear
3091 * encoded PNG file is written.
3092 *
3093 * With color-mapped data formats the colormap parameter point to a color-map
3094 * with at least image->colormap_entries encoded in the specified format. If
3095 * the format is linear the written PNG color-map will be converted to sRGB
3096 * regardless of the convert_to_8_bit flag.
3097 *
3098 * With all APIs row_stride is handled as in the read APIs - it is the spacing
3099 * from one row to the next in component sized units (1 or 2 bytes) and if
3100 * negative indicates a bottom-up row layout in the buffer. If row_stride is
3101 * zero, libpng will calculate it for you from the image width and number of
3102 * channels.
3103 *
3104 * Note that the write API does not support interlacing, sub-8-bit pixels or
3105 * most ancillary chunks. If you need to write text chunks (e.g. for copyright
3106 * notices) you need to use one of the other APIs.
3107 */
3108
3109 PNG_EXPORT(245, int, png_image_write_to_memory, (png_imagep image, void *memory,
3110 png_alloc_size_t * PNG_RESTRICT memory_bytes, int convert_to_8_bit,
3111 const void *buffer, png_int_32 row_stride, const void *colormap));
3112 /* Write the image to the given memory buffer. The function both writes the
3113 * whole PNG data stream to *memory and updates *memory_bytes with the count
3114 * of bytes written.
3115 *
3116 * 'memory' may be NULL. In this case *memory_bytes is not read however on
3117 * success the number of bytes which would have been written will still be
3118 * stored in *memory_bytes. On failure *memory_bytes will contain 0.
3119 *
3120 * If 'memory' is not NULL it must point to memory[*memory_bytes] of
3121 * writeable memory.
3122 *
3123 * If the function returns success memory[*memory_bytes] (if 'memory' is not
3124 * NULL) contains the written PNG data. *memory_bytes will always be less
3125 * than or equal to the original value.
3126 *
3127 * If the function returns false and *memory_bytes was not changed an error
3128 * occurred during write. If *memory_bytes was changed, or is not 0 if
3129 * 'memory' was NULL, the write would have succeeded but for the memory
3130 * buffer being too small. *memory_bytes contains the required number of
3131 * bytes and will be bigger that the original value.
3132 */
3133
3134 #define png_image_write_get_memory_size(image, size, convert_to_8_bit, buffer,\
3135 row_stride, colormap)\
3136 png_image_write_to_memory(&(image), 0, &(size), convert_to_8_bit, buffer,\
3137 row_stride, colormap)
3138 /* Return the amount of memory in 'size' required to compress this image.
3139 * The png_image structure 'image' must be filled in as in the above
3140 * function and must not be changed before the actual write call, the buffer
3141 * and all other parameters must also be identical to that in the final
3142 * write call. The 'size' variable need not be initialized.
3143 *
3144 * NOTE: the macro returns true/false, if false is returned 'size' will be
3145 * set to zero and the write failed and probably will fail if tried again.
3146 */
3147
3148 /* You can pre-allocate the buffer by making sure it is of sufficient size
3149 * regardless of the amount of compression achieved. The buffer size will
3150 * always be bigger than the original image and it will never be filled. The
3151 * following macros are provided to assist in allocating the buffer.
3152 */
3153 #define PNG_IMAGE_DATA_SIZE(image) (PNG_IMAGE_SIZE(image)+(image).height)
3154 /* The number of uncompressed bytes in the PNG byte encoding of the image;
3155 * uncompressing the PNG IDAT data will give this number of bytes.
3156 *
3157 * NOTE: while PNG_IMAGE_SIZE cannot overflow for an image in memory this
3158 * macro can because of the extra bytes used in the PNG byte encoding. You
3159 * need to avoid this macro if your image size approaches 2^30 in width or
3160 * height. The same goes for the remainder of these macros; they all produce
3161 * bigger numbers than the actual in-memory image size.
3162 */
3163 #ifndef PNG_ZLIB_MAX_SIZE
3164 # define PNG_ZLIB_MAX_SIZE(b) ((b)+(((b)+7U)>>3)+(((b)+63U)>>6)+11U)
3165 /* An upper bound on the number of compressed bytes given 'b' uncompressed
3166 * bytes. This is based on deflateBounds() in zlib; different
3167 * implementations of zlib compression may conceivably produce more data so
3168 * if your zlib implementation is not zlib itself redefine this macro
3169 * appropriately.
3170 */
3171 #endif
3172
3173 #define PNG_IMAGE_COMPRESSED_SIZE_MAX(image)\
3174 PNG_ZLIB_MAX_SIZE((png_alloc_size_t)PNG_IMAGE_DATA_SIZE(image))
3175 /* An upper bound on the size of the data in the PNG IDAT chunks. */
3176
3177 #define PNG_IMAGE_PNG_SIZE_MAX_(image, image_size)\
3178 ((8U/*sig*/+25U/*IHDR*/+16U/*gAMA*/+44U/*cHRM*/+12U/*IEND*/+\
3179 (((image).format&PNG_FORMAT_FLAG_COLORMAP)?/*colormap: PLTE, tRNS*/\
3180 12U+3U*(image).colormap_entries/*PLTE data*/+\
3181 (((image).format&PNG_FORMAT_FLAG_ALPHA)?\
3182 12U/*tRNS*/+(image).colormap_entries:0U):0U)+\
3183 12U)+(12U*((image_size)/PNG_ZBUF_SIZE))/*IDAT*/+(image_size))
3184 /* A helper for the following macro; if your compiler cannot handle the
3185 * following macro use this one with the result of
3186 * PNG_IMAGE_COMPRESSED_SIZE_MAX(image) as the second argument (most
3187 * compilers should handle this just fine.)
3188 */
3189
3190 #define PNG_IMAGE_PNG_SIZE_MAX(image)\
3191 PNG_IMAGE_PNG_SIZE_MAX_(image, PNG_IMAGE_COMPRESSED_SIZE_MAX(image))
3192 /* An upper bound on the total length of the PNG data stream for 'image'.
3193 * The result is of type png_alloc_size_t, on 32-bit systems this may
3194 * overflow even though PNG_IMAGE_DATA_SIZE does not overflow; the write will
3195 * run out of buffer space but return a corrected size which should work.
3196 */
3197 #endif /* SIMPLIFIED_WRITE */
3198 /*******************************************************************************
3199 * END OF SIMPLIFIED API
3200 ******************************************************************************/
3201 #endif /* SIMPLIFIED_{READ|WRITE} */
3202
3203 /*******************************************************************************
3204 * Section 6: IMPLEMENTATION OPTIONS
3205 *******************************************************************************
3206 *
3207 * Support for arbitrary implementation-specific optimizations. The API allows
3208 * particular options to be turned on or off. 'Option' is the number of the
3209 * option and 'onoff' is 0 (off) or non-0 (on). The value returned is given
3210 * by the PNG_OPTION_ defines below.
3211 *
3212 * HARDWARE: normally hardware capabilities, such as the Intel SSE instructions,
3213 * are detected at run time, however sometimes it may be impossible
3214 * to do this in user mode, in which case it is necessary to discover
3215 * the capabilities in an OS specific way. Such capabilities are
3216 * listed here when libpng has support for them and must be turned
3217 * ON by the application if present.
3218 *
3219 * SOFTWARE: sometimes software optimizations actually result in performance
3220 * decrease on some architectures or systems, or with some sets of
3221 * PNG images. 'Software' options allow such optimizations to be
3222 * selected at run time.
3223 */
3224 #ifdef PNG_SET_OPTION_SUPPORTED
3225 #ifdef PNG_ARM_NEON_API_SUPPORTED
3226 # define PNG_ARM_NEON 0 /* HARDWARE: ARM Neon SIMD instructions supported */
3227 #endif
3228 #define PNG_MAXIMUM_INFLATE_WINDOW 2 /* SOFTWARE: force maximum window */
3229 #define PNG_SKIP_sRGB_CHECK_PROFILE 4 /* SOFTWARE: Check ICC profile for sRGB */
3230 #ifdef PNG_MIPS_MSA_API_SUPPORTED
3231 # define PNG_MIPS_MSA 6 /* HARDWARE: MIPS Msa SIMD instructions supported */
3232 #endif
3233 #define PNG_IGNORE_ADLER32 8
3234 #ifdef PNG_POWERPC_VSX_API_SUPPORTED
3235 # define PNG_POWERPC_VSX 10 /* HARDWARE: PowerPC VSX SIMD instructions supported */
3236 #endif
3237 #define PNG_OPTION_NEXT 12 /* Next option - numbers must be even */
3238
3239 /* Return values: NOTE: there are four values and 'off' is *not* zero */
3240 #define PNG_OPTION_UNSET 0 /* Unset - defaults to off */
3241 #define PNG_OPTION_INVALID 1 /* Option number out of range */
3242 #define PNG_OPTION_OFF 2
3243 #define PNG_OPTION_ON 3
3244
3245 PNG_EXPORT(244, int, png_set_option, (png_structrp png_ptr, int option,
3246 int onoff));
3247 #endif /* SET_OPTION */
3248
3249 /*******************************************************************************
3250 * END OF HARDWARE AND SOFTWARE OPTIONS
3251 ******************************************************************************/
3252
3253 /* Maintainer: Put new public prototypes here ^, in libpng.3, in project
3254 * defs, and in scripts/symbols.def.
3255 */
3256
3257 /* The last ordinal number (this is the *last* one already used; the next
3258 * one to use is one more than this.)
3259 */
3260 #ifdef PNG_EXPORT_LAST_ORDINAL
3261 PNG_EXPORT_LAST_ORDINAL(249);
3262 #endif
3263
3264 #ifdef __cplusplus
3265 }
3266 #endif
3267
3268 #endif /* PNG_VERSION_INFO_ONLY */
3269 /* Do not put anything past this line */
3270 #endif /* PNG_H */