1 /*
2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
3 *
4 * This code is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License version 2 only, as
6 * published by the Free Software Foundation. Oracle designates this
7 * particular file as subject to the "Classpath" exception as provided
8 * by Oracle in the LICENSE file that accompanied this code.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 */
24
25 /* png.h - header file for PNG reference library
26 *
27 * This file is available under and governed by the GNU General Public
28 * License version 2 only, as published by the Free Software Foundation.
29 * However, the following notice accompanied the original version of this
30 * file and, per its terms, should not be removed:
31 *
32 * libpng version 1.6.20, December 3, 2015
33 *
34 * Copyright (c) 1998-2015 Glenn Randers-Pehrson
35 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
36 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
37 *
38 * This code is released under the libpng license (See LICENSE, below)
39 *
40 * Authors and maintainers:
41 * libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
42 * libpng versions 0.89, June 1996, through 0.96, May 1997: Andreas Dilger
43 * libpng versions 0.97, January 1998, through 1.6.20, December 3, 2015:
44 * Glenn Randers-Pehrson.
45 * See also "Contributing Authors", below.
46 */
47
48 /*
49 * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
50 *
51 * If you modify libpng you may insert additional notices immediately following
52 * this sentence.
53 *
54 * This code is released under the libpng license.
55 *
56 * libpng versions 1.0.7, July 1, 2000, through 1.6.20, December 3, 2015, are
57 * Copyright (c) 2000-2002, 2004, 2006-2015 Glenn Randers-Pehrson, are
58 * derived from libpng-1.0.6, and are distributed according to the same
59 * disclaimer and license as libpng-1.0.6 with the following individuals
60 * added to the list of Contributing Authors:
61 *
62 * Simon-Pierre Cadieux
63 * Eric S. Raymond
64 * Mans Rullgard
65 * Cosmin Truta
66 * Gilles Vollant
67 * James Yu
68 *
69 * and with the following additions to the disclaimer:
70 *
71 * There is no warranty against interference with your enjoyment of the
72 * library or against infringement. There is no warranty that our
73 * efforts or the library will fulfill any of your particular purposes
74 * or needs. This library is provided with all faults, and the entire
75 * risk of satisfactory quality, performance, accuracy, and effort is with
76 * the user.
77 *
78 * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
79 * Copyright (c) 1998-2000 Glenn Randers-Pehrson, are derived from
80 * libpng-0.96, and are distributed according to the same disclaimer and
81 * license as libpng-0.96, with the following individuals added to the list
82 * of Contributing Authors:
83 *
84 * Tom Lane
85 * Glenn Randers-Pehrson
86 * Willem van Schaik
87 *
88 * libpng versions 0.89, June 1996, through 0.96, May 1997, are
89 * Copyright (c) 1996-1997 Andreas Dilger, are derived from libpng-0.88,
90 * and are distributed according to the same disclaimer and license as
91 * libpng-0.88, with the following individuals added to the list of
92 * Contributing Authors:
93 *
94 * John Bowler
95 * Kevin Bracey
96 * Sam Bushell
97 * Magnus Holmgren
98 * Greg Roelofs
99 * Tom Tanner
100 *
101 * libpng versions 0.5, May 1995, through 0.88, January 1996, are
102 * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
103 *
104 * For the purposes of this copyright and license, "Contributing Authors"
105 * is defined as the following set of individuals:
106 *
107 * Andreas Dilger
108 * Dave Martindale
109 * Guy Eric Schalnat
110 * Paul Schmidt
111 * Tim Wegner
112 *
113 * The PNG Reference Library is supplied "AS IS". The Contributing Authors
114 * and Group 42, Inc. disclaim all warranties, expressed or implied,
115 * including, without limitation, the warranties of merchantability and of
116 * fitness for any purpose. The Contributing Authors and Group 42, Inc.
117 * assume no liability for direct, indirect, incidental, special, exemplary,
118 * or consequential damages, which may result from the use of the PNG
119 * Reference Library, even if advised of the possibility of such damage.
120 *
121 * Permission is hereby granted to use, copy, modify, and distribute this
122 * source code, or portions hereof, for any purpose, without fee, subject
123 * to the following restrictions:
124 *
125 * 1. The origin of this source code must not be misrepresented.
126 *
127 * 2. Altered versions must be plainly marked as such and must not
128 * be misrepresented as being the original source.
129 *
130 * 3. This Copyright notice may not be removed or altered from any
131 * source or altered source distribution.
132 *
133 * The Contributing Authors and Group 42, Inc. specifically permit, without
134 * fee, and encourage the use of this source code as a component to
135 * supporting the PNG file format in commercial products. If you use this
136 * source code in a product, acknowledgment is not required but would be
137 * appreciated.
138 *
139 * END OF COPYRIGHT NOTICE, DISCLAIMER, and LICENSE.
140 */
141
142 /*
143 * A "png_get_copyright" function is available, for convenient use in "about"
144 * boxes and the like:
145 *
146 * printf("%s", png_get_copyright(NULL));
147 *
148 * Also, the PNG logo (in PNG format, of course) is supplied in the
149 * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
150 */
151
152 /*
153 * Libpng is OSI Certified Open Source Software. OSI Certified Open Source is
154 * a certification mark of the Open Source Initiative. OSI has not addressed
155 * the additional disclaimers inserted at version 1.0.7.
156 */
157
158 /*
159 * The contributing authors would like to thank all those who helped
160 * with testing, bug fixes, and patience. This wouldn't have been
161 * possible without all of you.
162 *
163 * Thanks to Frank J. T. Wojcik for helping with the documentation.
164 */
165
166 /* Note about libpng version numbers:
167 *
168 * Due to various miscommunications, unforeseen code incompatibilities
169 * and occasional factors outside the authors' control, version numbering
170 * on the library has not always been consistent and straightforward.
171 * The following table summarizes matters since version 0.89c, which was
172 * the first widely used release:
173 *
174 * source png.h png.h shared-lib
175 * version string int version
176 * ------- ------ ----- ----------
177 * 0.89c "1.0 beta 3" 0.89 89 1.0.89
178 * 0.90 "1.0 beta 4" 0.90 90 0.90 [should have been 2.0.90]
179 * 0.95 "1.0 beta 5" 0.95 95 0.95 [should have been 2.0.95]
180 * 0.96 "1.0 beta 6" 0.96 96 0.96 [should have been 2.0.96]
181 * 0.97b "1.00.97 beta 7" 1.00.97 97 1.0.1 [should have been 2.0.97]
182 * 0.97c 0.97 97 2.0.97
183 * 0.98 0.98 98 2.0.98
184 * 0.99 0.99 98 2.0.99
185 * 0.99a-m 0.99 99 2.0.99
186 * 1.00 1.00 100 2.1.0 [100 should be 10000]
187 * 1.0.0 (from here on, the 100 2.1.0 [100 should be 10000]
188 * 1.0.1 png.h string is 10001 2.1.0
189 * 1.0.1a-e identical to the 10002 from here on, the shared library
190 * 1.0.2 source version) 10002 is 2.V where V is the source code
191 * 1.0.2a-b 10003 version, except as noted.
192 * 1.0.3 10003
193 * 1.0.3a-d 10004
194 * 1.0.4 10004
195 * 1.0.4a-f 10005
196 * 1.0.5 (+ 2 patches) 10005
197 * 1.0.5a-d 10006
198 * 1.0.5e-r 10100 (not source compatible)
199 * 1.0.5s-v 10006 (not binary compatible)
200 * 1.0.6 (+ 3 patches) 10006 (still binary incompatible)
201 * 1.0.6d-f 10007 (still binary incompatible)
202 * 1.0.6g 10007
203 * 1.0.6h 10007 10.6h (testing xy.z so-numbering)
204 * 1.0.6i 10007 10.6i
205 * 1.0.6j 10007 2.1.0.6j (incompatible with 1.0.0)
206 * 1.0.7beta11-14 DLLNUM 10007 2.1.0.7beta11-14 (binary compatible)
207 * 1.0.7beta15-18 1 10007 2.1.0.7beta15-18 (binary compatible)
208 * 1.0.7rc1-2 1 10007 2.1.0.7rc1-2 (binary compatible)
209 * 1.0.7 1 10007 (still compatible)
210 * ...
211 * 1.0.19 10 10019 10.so.0.19[.0]
212 * ...
213 * 1.2.53 13 10253 12.so.0.53[.0]
214 * ...
215 * 1.5.23 15 10523 15.so.15.23[.0]
216 * ...
217 * 1.6.20 16 10620 16.so.16.20[.0]
218 *
219 * Henceforth the source version will match the shared-library major
220 * and minor numbers; the shared-library major version number will be
221 * used for changes in backward compatibility, as it is intended. The
222 * PNG_LIBPNG_VER macro, which is not used within libpng but is available
223 * for applications, is an unsigned integer of the form xyyzz corresponding
224 * to the source version x.y.z (leading zeros in y and z). Beta versions
225 * were given the previous public release number plus a letter, until
226 * version 1.0.6j; from then on they were given the upcoming public
227 * release number plus "betaNN" or "rcNN".
228 *
229 * Binary incompatibility exists only when applications make direct access
230 * to the info_ptr or png_ptr members through png.h, and the compiled
231 * application is loaded with a different version of the library.
232 *
233 * DLLNUM will change each time there are forward or backward changes
234 * in binary compatibility (e.g., when a new feature is added).
235 *
236 * See libpng.txt or libpng.3 for more information. The PNG specification
237 * is available as a W3C Recommendation and as an ISO Specification,
238 * <http://www.w3.org/TR/2003/REC-PNG-20031110/
239 */
240
241 /*
242 * Y2K compliance in libpng:
243 * =========================
244 *
245 * December 3, 2015
246 *
247 * Since the PNG Development group is an ad-hoc body, we can't make
248 * an official declaration.
249 *
250 * This is your unofficial assurance that libpng from version 0.71 and
251 * upward through 1.6.20 are Y2K compliant. It is my belief that
252 * earlier versions were also Y2K compliant.
253 *
254 * Libpng only has two year fields. One is a 2-byte unsigned integer
255 * that will hold years up to 65535. The other, which is deprecated,
256 * holds the date in text format, and will hold years up to 9999.
257 *
258 * The integer is
259 * "png_uint_16 year" in png_time_struct.
260 *
261 * The string is
262 * "char time_buffer[29]" in png_struct. This is no longer used
263 * in libpng-1.6.x and will be removed from libpng-1.7.0.
264 *
265 * There are seven time-related functions:
266 * png.c: png_convert_to_rfc_1123_buffer() in png.c
267 * (formerly png_convert_to_rfc_1123() prior to libpng-1.5.x and
268 * png_convert_to_rfc_1152() in error prior to libpng-0.98)
269 * png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
270 * png_convert_from_time_t() in pngwrite.c
271 * png_get_tIME() in pngget.c
272 * png_handle_tIME() in pngrutil.c, called in pngread.c
273 * png_set_tIME() in pngset.c
274 * png_write_tIME() in pngwutil.c, called in pngwrite.c
275 *
276 * All handle dates properly in a Y2K environment. The
277 * png_convert_from_time_t() function calls gmtime() to convert from system
278 * clock time, which returns (year - 1900), which we properly convert to
279 * the full 4-digit year. There is a possibility that libpng applications
280 * are not passing 4-digit years into the png_convert_to_rfc_1123_buffer()
281 * function, or that they are incorrectly passing only a 2-digit year
282 * instead of "year - 1900" into the png_convert_from_struct_tm() function,
283 * but this is not under our control. The libpng documentation has always
284 * stated that it works with 4-digit years, and the APIs have been
285 * documented as such.
286 *
287 * The tIME chunk itself is also Y2K compliant. It uses a 2-byte unsigned
288 * integer to hold the year, and can hold years as large as 65535.
289 *
290 * zlib, upon which libpng depends, is also Y2K compliant. It contains
291 * no date-related code.
292 *
293 * Glenn Randers-Pehrson
294 * libpng maintainer
295 * PNG Development Group
296 */
297
298 #ifndef PNG_H
299 #define PNG_H
300
301 /* This is not the place to learn how to use libpng. The file libpng-manual.txt
302 * describes how to use libpng, and the file example.c summarizes it
303 * with some code on which to build. This file is useful for looking
304 * at the actual function definitions and structure components. If that
305 * file has been stripped from your copy of libpng, you can find it at
306 * <http://www.libpng.org/pub/png/libpng-manual.txt>
307 *
308 * If you just need to read a PNG file and don't want to read the documentation
309 * skip to the end of this file and read the section entitled 'simplified API'.
310 */
311
312 /* Version information for png.h - this should match the version in png.c */
313 #define PNG_LIBPNG_VER_STRING "1.6.20"
314 #define PNG_HEADER_VERSION_STRING \
315 " libpng version 1.6.20 - December 3, 2015\n"
316
317 #define PNG_LIBPNG_VER_SONUM 16
318 #define PNG_LIBPNG_VER_DLLNUM 16
319
320 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
321 #define PNG_LIBPNG_VER_MAJOR 1
322 #define PNG_LIBPNG_VER_MINOR 6
323 #define PNG_LIBPNG_VER_RELEASE 20
324
325 /* This should match the numeric part of the final component of
326 * PNG_LIBPNG_VER_STRING, omitting any leading zero:
327 */
328
329 #define PNG_LIBPNG_VER_BUILD 0
330
331 /* Release Status */
332 #define PNG_LIBPNG_BUILD_ALPHA 1
333 #define PNG_LIBPNG_BUILD_BETA 2
334 #define PNG_LIBPNG_BUILD_RC 3
335 #define PNG_LIBPNG_BUILD_STABLE 4
336 #define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7
337
338 /* Release-Specific Flags */
339 #define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with
340 PNG_LIBPNG_BUILD_STABLE only */
341 #define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with
342 PNG_LIBPNG_BUILD_SPECIAL */
343 #define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with
344 PNG_LIBPNG_BUILD_PRIVATE */
345
346 #define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE
347
348 /* Careful here. At one time, Guy wanted to use 082, but that would be octal.
349 * We must not include leading zeros.
350 * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only
351 * version 1.0.0 was mis-numbered 100 instead of 10000). From
352 * version 1.0.1 it's xxyyzz, where x=major, y=minor, z=release
353 */
354 #define PNG_LIBPNG_VER 10620 /* 1.6.20 */
355
356 /* Library configuration: these options cannot be changed after
357 * the library has been built.
358 */
359 #ifndef PNGLCONF_H
360 /* If pnglibconf.h is missing, you can
361 * copy scripts/pnglibconf.h.prebuilt to pnglibconf.h
362 */
363 # include "pnglibconf.h"
364 #endif
365
366 #ifndef PNG_VERSION_INFO_ONLY
367 /* Machine specific configuration. */
368 # include "pngconf.h"
369 #endif
370
371 /*
372 * Added at libpng-1.2.8
373 *
374 * Ref MSDN: Private as priority over Special
375 * VS_FF_PRIVATEBUILD File *was not* built using standard release
376 * procedures. If this value is given, the StringFileInfo block must
377 * contain a PrivateBuild string.
378 *
379 * VS_FF_SPECIALBUILD File *was* built by the original company using
380 * standard release procedures but is a variation of the standard
381 * file of the same version number. If this value is given, the
382 * StringFileInfo block must contain a SpecialBuild string.
383 */
384
385 #ifdef PNG_USER_PRIVATEBUILD /* From pnglibconf.h */
386 # define PNG_LIBPNG_BUILD_TYPE \
387 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE)
388 #else
389 # ifdef PNG_LIBPNG_SPECIALBUILD
390 # define PNG_LIBPNG_BUILD_TYPE \
391 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL)
392 # else
393 # define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE)
394 # endif
395 #endif
396
397 #ifndef PNG_VERSION_INFO_ONLY
398
399 /* Inhibit C++ name-mangling for libpng functions but not for system calls. */
400 #ifdef __cplusplus
401 extern "C" {
402 #endif /* __cplusplus */
403
404 /* Version information for C files, stored in png.c. This had better match
405 * the version above.
406 */
407 #define png_libpng_ver png_get_header_ver(NULL)
408
409 /* This file is arranged in several sections:
410 *
411 * 1. [omitted]
412 * 2. Any configuration options that can be specified by for the application
413 * code when it is built. (Build time configuration is in pnglibconf.h)
414 * 3. Type definitions (base types are defined in pngconf.h), structure
415 * definitions.
416 * 4. Exported library functions.
417 * 5. Simplified API.
418 * 6. Implementation options.
419 *
420 * The library source code has additional files (principally pngpriv.h) that
421 * allow configuration of the library.
422 */
423
424 /* Section 1: [omitted] */
425
426 /* Section 2: run time configuration
427 * See pnglibconf.h for build time configuration
428 *
429 * Run time configuration allows the application to choose between
430 * implementations of certain arithmetic APIs. The default is set
431 * at build time and recorded in pnglibconf.h, but it is safe to
432 * override these (and only these) settings. Note that this won't
433 * change what the library does, only application code, and the
434 * settings can (and probably should) be made on a per-file basis
435 * by setting the #defines before including png.h
436 *
437 * Use macros to read integers from PNG data or use the exported
438 * functions?
439 * PNG_USE_READ_MACROS: use the macros (see below) Note that
440 * the macros evaluate their argument multiple times.
441 * PNG_NO_USE_READ_MACROS: call the relevant library function.
442 *
443 * Use the alternative algorithm for compositing alpha samples that
444 * does not use division?
445 * PNG_READ_COMPOSITE_NODIV_SUPPORTED: use the 'no division'
446 * algorithm.
447 * PNG_NO_READ_COMPOSITE_NODIV: use the 'division' algorithm.
448 *
449 * How to handle benign errors if PNG_ALLOW_BENIGN_ERRORS is
450 * false?
451 * PNG_ALLOW_BENIGN_ERRORS: map calls to the benign error
452 * APIs to png_warning.
453 * Otherwise the calls are mapped to png_error.
454 */
455
456 /* Section 3: type definitions, including structures and compile time
457 * constants.
458 * See pngconf.h for base types that vary by machine/system
459 */
460
461 /* This triggers a compiler error in png.c, if png.c and png.h
462 * do not agree upon the version number.
463 */
464 typedef char* png_libpng_version_1_6_20;
465
466 /* Basic control structions. Read libpng-manual.txt or libpng.3 for more info.
467 *
468 * png_struct is the cache of information used while reading or writing a single
469 * PNG file. One of these is always required, although the simplified API
470 * (below) hides the creation and destruction of it.
471 */
472 typedef struct png_struct_def png_struct;
473 typedef const png_struct * png_const_structp;
474 typedef png_struct * png_structp;
475 typedef png_struct * * png_structpp;
476
477 /* png_info contains information read from or to be written to a PNG file. One
478 * or more of these must exist while reading or creating a PNG file. The
479 * information is not used by libpng during read but is used to control what
480 * gets written when a PNG file is created. "png_get_" function calls read
481 * information during read and "png_set_" functions calls write information
482 * when creating a PNG.
483 * been moved into a separate header file that is not accessible to
484 * applications. Read libpng-manual.txt or libpng.3 for more info.
485 */
486 typedef struct png_info_def png_info;
487 typedef png_info * png_infop;
488 typedef const png_info * png_const_infop;
489 typedef png_info * * png_infopp;
490
491 /* Types with names ending 'p' are pointer types. The corresponding types with
492 * names ending 'rp' are identical pointer types except that the pointer is
493 * marked 'restrict', which means that it is the only pointer to the object
494 * passed to the function. Applications should not use the 'restrict' types;
495 * it is always valid to pass 'p' to a pointer with a function argument of the
496 * corresponding 'rp' type. Different compilers have different rules with
497 * regard to type matching in the presence of 'restrict'. For backward
498 * compatibility libpng callbacks never have 'restrict' in their parameters and,
499 * consequentially, writing portable application code is extremely difficult if
500 * an attempt is made to use 'restrict'.
501 */
502 typedef png_struct * PNG_RESTRICT png_structrp;
503 typedef const png_struct * PNG_RESTRICT png_const_structrp;
504 typedef png_info * PNG_RESTRICT png_inforp;
505 typedef const png_info * PNG_RESTRICT png_const_inforp;
506
507 /* Three color definitions. The order of the red, green, and blue, (and the
508 * exact size) is not important, although the size of the fields need to
509 * be png_byte or png_uint_16 (as defined below).
510 */
511 typedef struct png_color_struct
512 {
513 png_byte red;
514 png_byte green;
515 png_byte blue;
516 } png_color;
517 typedef png_color * png_colorp;
518 typedef const png_color * png_const_colorp;
519 typedef png_color * * png_colorpp;
520
521 typedef struct png_color_16_struct
522 {
523 png_byte index; /* used for palette files */
524 png_uint_16 red; /* for use in red green blue files */
525 png_uint_16 green;
526 png_uint_16 blue;
527 png_uint_16 gray; /* for use in grayscale files */
528 } png_color_16;
529 typedef png_color_16 * png_color_16p;
530 typedef const png_color_16 * png_const_color_16p;
531 typedef png_color_16 * * png_color_16pp;
532
533 typedef struct png_color_8_struct
534 {
535 png_byte red; /* for use in red green blue files */
536 png_byte green;
537 png_byte blue;
538 png_byte gray; /* for use in grayscale files */
539 png_byte alpha; /* for alpha channel files */
540 } png_color_8;
541 typedef png_color_8 * png_color_8p;
542 typedef const png_color_8 * png_const_color_8p;
543 typedef png_color_8 * * png_color_8pp;
544
545 /*
546 * The following two structures are used for the in-core representation
547 * of sPLT chunks.
548 */
549 typedef struct png_sPLT_entry_struct
550 {
551 png_uint_16 red;
552 png_uint_16 green;
553 png_uint_16 blue;
554 png_uint_16 alpha;
555 png_uint_16 frequency;
556 } png_sPLT_entry;
557 typedef png_sPLT_entry * png_sPLT_entryp;
558 typedef const png_sPLT_entry * png_const_sPLT_entryp;
559 typedef png_sPLT_entry * * png_sPLT_entrypp;
560
561 /* When the depth of the sPLT palette is 8 bits, the color and alpha samples
562 * occupy the LSB of their respective members, and the MSB of each member
563 * is zero-filled. The frequency member always occupies the full 16 bits.
564 */
565
566 typedef struct png_sPLT_struct
567 {
568 png_charp name; /* palette name */
569 png_byte depth; /* depth of palette samples */
570 png_sPLT_entryp entries; /* palette entries */
571 png_int_32 nentries; /* number of palette entries */
572 } png_sPLT_t;
573 typedef png_sPLT_t * png_sPLT_tp;
574 typedef const png_sPLT_t * png_const_sPLT_tp;
575 typedef png_sPLT_t * * png_sPLT_tpp;
576
577 #ifdef PNG_TEXT_SUPPORTED
578 /* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,
579 * and whether that contents is compressed or not. The "key" field
580 * points to a regular zero-terminated C string. The "text" fields can be a
581 * regular C string, an empty string, or a NULL pointer.
582 * However, the structure returned by png_get_text() will always contain
583 * the "text" field as a regular zero-terminated C string (possibly
584 * empty), never a NULL pointer, so it can be safely used in printf() and
585 * other string-handling functions. Note that the "itxt_length", "lang", and
586 * "lang_key" members of the structure only exist when the library is built
587 * with iTXt chunk support. Prior to libpng-1.4.0 the library was built by
588 * default without iTXt support. Also note that when iTXt *is* supported,
589 * the "lang" and "lang_key" fields contain NULL pointers when the
590 * "compression" field contains * PNG_TEXT_COMPRESSION_NONE or
591 * PNG_TEXT_COMPRESSION_zTXt. Note that the "compression value" is not the
592 * same as what appears in the PNG tEXt/zTXt/iTXt chunk's "compression flag"
593 * which is always 0 or 1, or its "compression method" which is always 0.
594 */
595 typedef struct png_text_struct
596 {
597 int compression; /* compression value:
598 -1: tEXt, none
599 0: zTXt, deflate
600 1: iTXt, none
601 2: iTXt, deflate */
602 png_charp key; /* keyword, 1-79 character description of "text" */
603 png_charp text; /* comment, may be an empty string (ie "")
604 or a NULL pointer */
605 png_size_t text_length; /* length of the text string */
606 png_size_t itxt_length; /* length of the itxt string */
607 png_charp lang; /* language code, 0-79 characters
608 or a NULL pointer */
609 png_charp lang_key; /* keyword translated UTF-8 string, 0 or more
610 chars or a NULL pointer */
611 } png_text;
612 typedef png_text * png_textp;
613 typedef const png_text * png_const_textp;
614 typedef png_text * * png_textpp;
615 #endif
616
617 /* Supported compression types for text in PNG files (tEXt, and zTXt).
618 * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */
619 #define PNG_TEXT_COMPRESSION_NONE_WR -3
620 #define PNG_TEXT_COMPRESSION_zTXt_WR -2
621 #define PNG_TEXT_COMPRESSION_NONE -1
622 #define PNG_TEXT_COMPRESSION_zTXt 0
623 #define PNG_ITXT_COMPRESSION_NONE 1
624 #define PNG_ITXT_COMPRESSION_zTXt 2
625 #define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */
626
627 /* png_time is a way to hold the time in an machine independent way.
628 * Two conversions are provided, both from time_t and struct tm. There
629 * is no portable way to convert to either of these structures, as far
630 * as I know. If you know of a portable way, send it to me. As a side
631 * note - PNG has always been Year 2000 compliant!
632 */
633 typedef struct png_time_struct
634 {
635 png_uint_16 year; /* full year, as in, 1995 */
636 png_byte month; /* month of year, 1 - 12 */
637 png_byte day; /* day of month, 1 - 31 */
638 png_byte hour; /* hour of day, 0 - 23 */
639 png_byte minute; /* minute of hour, 0 - 59 */
640 png_byte second; /* second of minute, 0 - 60 (for leap seconds) */
641 } png_time;
642 typedef png_time * png_timep;
643 typedef const png_time * png_const_timep;
644 typedef png_time * * png_timepp;
645
646 #if defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) ||\
647 defined(PNG_USER_CHUNKS_SUPPORTED)
648 /* png_unknown_chunk is a structure to hold queued chunks for which there is
649 * no specific support. The idea is that we can use this to queue
650 * up private chunks for output even though the library doesn't actually
651 * know about their semantics.
652 *
653 * The data in the structure is set by libpng on read and used on write.
654 */
655 typedef struct png_unknown_chunk_t
656 {
657 png_byte name[5]; /* Textual chunk name with '\0' terminator */
658 png_byte *data; /* Data, should not be modified on read! */
659 png_size_t size;
660
661 /* On write 'location' must be set using the flag values listed below.
662 * Notice that on read it is set by libpng however the values stored have
663 * more bits set than are listed below. Always treat the value as a
664 * bitmask. On write set only one bit - setting multiple bits may cause the
665 * chunk to be written in multiple places.
666 */
667 png_byte location; /* mode of operation at read time */
668 }
669 png_unknown_chunk;
670
671 typedef png_unknown_chunk * png_unknown_chunkp;
672 typedef const png_unknown_chunk * png_const_unknown_chunkp;
673 typedef png_unknown_chunk * * png_unknown_chunkpp;
674 #endif
675
676 /* Flag values for the unknown chunk location byte. */
677 #define PNG_HAVE_IHDR 0x01
678 #define PNG_HAVE_PLTE 0x02
679 #define PNG_AFTER_IDAT 0x08
680
681 /* Maximum positive integer used in PNG is (2^31)-1 */
682 #define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL)
683 #define PNG_UINT_32_MAX ((png_uint_32)(-1))
684 #define PNG_SIZE_MAX ((png_size_t)(-1))
685
686 /* These are constants for fixed point values encoded in the
687 * PNG specification manner (x100000)
688 */
689 #define PNG_FP_1 100000
690 #define PNG_FP_HALF 50000
691 #define PNG_FP_MAX ((png_fixed_point)0x7fffffffL)
692 #define PNG_FP_MIN (-PNG_FP_MAX)
693
694 /* These describe the color_type field in png_info. */
695 /* color type masks */
696 #define PNG_COLOR_MASK_PALETTE 1
697 #define PNG_COLOR_MASK_COLOR 2
698 #define PNG_COLOR_MASK_ALPHA 4
699
700 /* color types. Note that not all combinations are legal */
701 #define PNG_COLOR_TYPE_GRAY 0
702 #define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
703 #define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR)
704 #define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
705 #define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
706 /* aliases */
707 #define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA
708 #define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA
709
710 /* This is for compression type. PNG 1.0-1.2 only define the single type. */
711 #define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */
712 #define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE
713
714 /* This is for filter type. PNG 1.0-1.2 only define the single type. */
715 #define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */
716 #define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */
717 #define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE
718
719 /* These are for the interlacing type. These values should NOT be changed. */
720 #define PNG_INTERLACE_NONE 0 /* Non-interlaced image */
721 #define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */
722 #define PNG_INTERLACE_LAST 2 /* Not a valid value */
723
724 /* These are for the oFFs chunk. These values should NOT be changed. */
725 #define PNG_OFFSET_PIXEL 0 /* Offset in pixels */
726 #define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */
727 #define PNG_OFFSET_LAST 2 /* Not a valid value */
728
729 /* These are for the pCAL chunk. These values should NOT be changed. */
730 #define PNG_EQUATION_LINEAR 0 /* Linear transformation */
731 #define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */
732 #define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */
733 #define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */
734 #define PNG_EQUATION_LAST 4 /* Not a valid value */
735
736 /* These are for the sCAL chunk. These values should NOT be changed. */
737 #define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */
738 #define PNG_SCALE_METER 1 /* meters per pixel */
739 #define PNG_SCALE_RADIAN 2 /* radians per pixel */
740 #define PNG_SCALE_LAST 3 /* Not a valid value */
741
742 /* These are for the pHYs chunk. These values should NOT be changed. */
743 #define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */
744 #define PNG_RESOLUTION_METER 1 /* pixels/meter */
745 #define PNG_RESOLUTION_LAST 2 /* Not a valid value */
746
747 /* These are for the sRGB chunk. These values should NOT be changed. */
748 #define PNG_sRGB_INTENT_PERCEPTUAL 0
749 #define PNG_sRGB_INTENT_RELATIVE 1
750 #define PNG_sRGB_INTENT_SATURATION 2
751 #define PNG_sRGB_INTENT_ABSOLUTE 3
752 #define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */
753
754 /* This is for text chunks */
755 #define PNG_KEYWORD_MAX_LENGTH 79
756
757 /* Maximum number of entries in PLTE/sPLT/tRNS arrays */
758 #define PNG_MAX_PALETTE_LENGTH 256
759
760 /* These determine if an ancillary chunk's data has been successfully read
761 * from the PNG header, or if the application has filled in the corresponding
762 * data in the info_struct to be written into the output file. The values
763 * of the PNG_INFO_<chunk> defines should NOT be changed.
764 */
765 #define PNG_INFO_gAMA 0x0001
766 #define PNG_INFO_sBIT 0x0002
767 #define PNG_INFO_cHRM 0x0004
768 #define PNG_INFO_PLTE 0x0008
769 #define PNG_INFO_tRNS 0x0010
770 #define PNG_INFO_bKGD 0x0020
771 #define PNG_INFO_hIST 0x0040
772 #define PNG_INFO_pHYs 0x0080
773 #define PNG_INFO_oFFs 0x0100
774 #define PNG_INFO_tIME 0x0200
775 #define PNG_INFO_pCAL 0x0400
776 #define PNG_INFO_sRGB 0x0800 /* GR-P, 0.96a */
777 #define PNG_INFO_iCCP 0x1000 /* ESR, 1.0.6 */
778 #define PNG_INFO_sPLT 0x2000 /* ESR, 1.0.6 */
779 #define PNG_INFO_sCAL 0x4000 /* ESR, 1.0.6 */
780 #if INT_MAX >= 0x8000 /* else this might break */
781 #define PNG_INFO_IDAT 0x8000 /* ESR, 1.0.6 */
782 #endif
783
784 /* This is used for the transformation routines, as some of them
785 * change these values for the row. It also should enable using
786 * the routines for other purposes.
787 */
788 typedef struct png_row_info_struct
789 {
790 png_uint_32 width; /* width of row */
791 png_size_t rowbytes; /* number of bytes in row */
792 png_byte color_type; /* color type of row */
793 png_byte bit_depth; /* bit depth of row */
794 png_byte channels; /* number of channels (1, 2, 3, or 4) */
795 png_byte pixel_depth; /* bits per pixel (depth * channels) */
796 } png_row_info;
797
798 typedef png_row_info * png_row_infop;
799 typedef png_row_info * * png_row_infopp;
800
801 /* These are the function types for the I/O functions and for the functions
802 * that allow the user to override the default I/O functions with his or her
803 * own. The png_error_ptr type should match that of user-supplied warning
804 * and error functions, while the png_rw_ptr type should match that of the
805 * user read/write data functions. Note that the 'write' function must not
806 * modify the buffer it is passed. The 'read' function, on the other hand, is
807 * expected to return the read data in the buffer.
808 */
809 typedef PNG_CALLBACK(void, *png_error_ptr, (png_structp, png_const_charp));
810 typedef PNG_CALLBACK(void, *png_rw_ptr, (png_structp, png_bytep, png_size_t));
811 typedef PNG_CALLBACK(void, *png_flush_ptr, (png_structp));
812 typedef PNG_CALLBACK(void, *png_read_status_ptr, (png_structp, png_uint_32,
813 int));
814 typedef PNG_CALLBACK(void, *png_write_status_ptr, (png_structp, png_uint_32,
815 int));
816
817 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
818 typedef PNG_CALLBACK(void, *png_progressive_info_ptr, (png_structp, png_infop));
819 typedef PNG_CALLBACK(void, *png_progressive_end_ptr, (png_structp, png_infop));
820
821 /* The following callback receives png_uint_32 row_number, int pass for the
822 * png_bytep data of the row. When transforming an interlaced image the
823 * row number is the row number within the sub-image of the interlace pass, so
824 * the value will increase to the height of the sub-image (not the full image)
825 * then reset to 0 for the next pass.
826 *
827 * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
828 * find the output pixel (x,y) given an interlaced sub-image pixel
829 * (row,col,pass). (See below for these macros.)
830 */
831 typedef PNG_CALLBACK(void, *png_progressive_row_ptr, (png_structp, png_bytep,
832 png_uint_32, int));
833 #endif
834
835 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
836 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
837 typedef PNG_CALLBACK(void, *png_user_transform_ptr, (png_structp, png_row_infop,
838 png_bytep));
839 #endif
840
841 #ifdef PNG_USER_CHUNKS_SUPPORTED
842 typedef PNG_CALLBACK(int, *png_user_chunk_ptr, (png_structp,
843 png_unknown_chunkp));
844 #endif
845 #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
846 /* not used anywhere */
847 /* typedef PNG_CALLBACK(void, *png_unknown_chunk_ptr, (png_structp)); */
848 #endif
849
850 #ifdef PNG_SETJMP_SUPPORTED
851 /* This must match the function definition in <setjmp.h>, and the application
852 * must include this before png.h to obtain the definition of jmp_buf. The
853 * function is required to be PNG_NORETURN, but this is not checked. If the
854 * function does return the application will crash via an abort() or similar
855 * system level call.
856 *
857 * If you get a warning here while building the library you may need to make
858 * changes to ensure that pnglibconf.h records the calling convention used by
859 * your compiler. This may be very difficult - try using a different compiler
860 * to build the library!
861 */
862 PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)), typedef);
863 #endif
864
865 /* Transform masks for the high-level interface */
866 #define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */
867 #define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */
868 #define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */
869 #define PNG_TRANSFORM_PACKING 0x0004 /* read and write */
870 #define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */
871 #define PNG_TRANSFORM_EXPAND 0x0010 /* read only */
872 #define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */
873 #define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */
874 #define PNG_TRANSFORM_BGR 0x0080 /* read and write */
875 #define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */
876 #define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */
877 #define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */
878 #define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* write only */
879 /* Added to libpng-1.2.34 */
880 #define PNG_TRANSFORM_STRIP_FILLER_BEFORE PNG_TRANSFORM_STRIP_FILLER
881 #define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */
882 /* Added to libpng-1.4.0 */
883 #define PNG_TRANSFORM_GRAY_TO_RGB 0x2000 /* read only */
884 /* Added to libpng-1.5.4 */
885 #define PNG_TRANSFORM_EXPAND_16 0x4000 /* read only */
886 #if INT_MAX >= 0x8000 /* else this might break */
887 #define PNG_TRANSFORM_SCALE_16 0x8000 /* read only */
888 #endif
889
890 /* Flags for MNG supported features */
891 #define PNG_FLAG_MNG_EMPTY_PLTE 0x01
892 #define PNG_FLAG_MNG_FILTER_64 0x04
893 #define PNG_ALL_MNG_FEATURES 0x05
894
895 /* NOTE: prior to 1.5 these functions had no 'API' style declaration,
896 * this allowed the zlib default functions to be used on Windows
897 * platforms. In 1.5 the zlib default malloc (which just calls malloc and
898 * ignores the first argument) should be completely compatible with the
899 * following.
900 */
901 typedef PNG_CALLBACK(png_voidp, *png_malloc_ptr, (png_structp,
902 png_alloc_size_t));
903 typedef PNG_CALLBACK(void, *png_free_ptr, (png_structp, png_voidp));
904
905 /* Section 4: exported functions
906 * Here are the function definitions most commonly used. This is not
907 * the place to find out how to use libpng. See libpng-manual.txt for the
908 * full explanation, see example.c for the summary. This just provides
909 * a simple one line description of the use of each function.
910 *
911 * The PNG_EXPORT() and PNG_EXPORTA() macros used below are defined in
912 * pngconf.h and in the *.dfn files in the scripts directory.
913 *
914 * PNG_EXPORT(ordinal, type, name, (args));
915 *
916 * ordinal: ordinal that is used while building
917 * *.def files. The ordinal value is only
918 * relevant when preprocessing png.h with
919 * the *.dfn files for building symbol table
920 * entries, and are removed by pngconf.h.
921 * type: return type of the function
922 * name: function name
923 * args: function arguments, with types
924 *
925 * When we wish to append attributes to a function prototype we use
926 * the PNG_EXPORTA() macro instead.
927 *
928 * PNG_EXPORTA(ordinal, type, name, (args), attributes);
929 *
930 * ordinal, type, name, and args: same as in PNG_EXPORT().
931 * attributes: function attributes
932 */
933
934 /* Returns the version number of the library */
935 PNG_EXPORT(1, png_uint_32, png_access_version_number, (void));
936
937 /* Tell lib we have already handled the first <num_bytes> magic bytes.
938 * Handling more than 8 bytes from the beginning of the file is an error.
939 */
940 PNG_EXPORT(2, void, png_set_sig_bytes, (png_structrp png_ptr, int num_bytes));
941
942 /* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
943 * PNG file. Returns zero if the supplied bytes match the 8-byte PNG
944 * signature, and non-zero otherwise. Having num_to_check == 0 or
945 * start > 7 will always fail (ie return non-zero).
946 */
947 PNG_EXPORT(3, int, png_sig_cmp, (png_const_bytep sig, png_size_t start,
948 png_size_t num_to_check));
949
950 /* Simple signature checking function. This is the same as calling
951 * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n).
952 */
953 #define png_check_sig(sig, n) !png_sig_cmp((sig), 0, (n))
954
955 /* Allocate and initialize png_ptr struct for reading, and any other memory. */
956 PNG_EXPORTA(4, png_structp, png_create_read_struct,
957 (png_const_charp user_png_ver, png_voidp error_ptr,
958 png_error_ptr error_fn, png_error_ptr warn_fn),
959 PNG_ALLOCATED);
960
961 /* Allocate and initialize png_ptr struct for writing, and any other memory */
962 PNG_EXPORTA(5, png_structp, png_create_write_struct,
963 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
964 png_error_ptr warn_fn),
965 PNG_ALLOCATED);
966
967 PNG_EXPORT(6, png_size_t, png_get_compression_buffer_size,
968 (png_const_structrp png_ptr));
969
970 PNG_EXPORT(7, void, png_set_compression_buffer_size, (png_structrp png_ptr,
971 png_size_t size));
972
973 /* Moved from pngconf.h in 1.4.0 and modified to ensure setjmp/longjmp
974 * match up.
975 */
976 #ifdef PNG_SETJMP_SUPPORTED
977 /* This function returns the jmp_buf built in to *png_ptr. It must be
978 * supplied with an appropriate 'longjmp' function to use on that jmp_buf
979 * unless the default error function is overridden in which case NULL is
980 * acceptable. The size of the jmp_buf is checked against the actual size
981 * allocated by the library - the call will return NULL on a mismatch
982 * indicating an ABI mismatch.
983 */
984 PNG_EXPORT(8, jmp_buf*, png_set_longjmp_fn, (png_structrp png_ptr,
985 png_longjmp_ptr longjmp_fn, size_t jmp_buf_size));
986 # define png_jmpbuf(png_ptr) \
987 (*png_set_longjmp_fn((png_ptr), longjmp, (sizeof (jmp_buf))))
988 #else
989 # define png_jmpbuf(png_ptr) \
990 (LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP)
991 #endif
992 /* This function should be used by libpng applications in place of
993 * longjmp(png_ptr->jmpbuf, val). If longjmp_fn() has been set, it
994 * will use it; otherwise it will call PNG_ABORT(). This function was
995 * added in libpng-1.5.0.
996 */
997 PNG_EXPORTA(9, void, png_longjmp, (png_const_structrp png_ptr, int val),
998 PNG_NORETURN);
999
1000 #ifdef PNG_READ_SUPPORTED
1001 /* Reset the compression stream */
1002 PNG_EXPORTA(10, int, png_reset_zstream, (png_structrp png_ptr), PNG_DEPRECATED);
1003 #endif
1004
1005 /* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */
1006 #ifdef PNG_USER_MEM_SUPPORTED
1007 PNG_EXPORTA(11, png_structp, png_create_read_struct_2,
1008 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
1009 png_error_ptr warn_fn,
1010 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn),
1011 PNG_ALLOCATED);
1012 PNG_EXPORTA(12, png_structp, png_create_write_struct_2,
1013 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
1014 png_error_ptr warn_fn,
1015 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn),
1016 PNG_ALLOCATED);
1017 #endif
1018
1019 /* Write the PNG file signature. */
1020 PNG_EXPORT(13, void, png_write_sig, (png_structrp png_ptr));
1021
1022 /* Write a PNG chunk - size, type, (optional) data, CRC. */
1023 PNG_EXPORT(14, void, png_write_chunk, (png_structrp png_ptr, png_const_bytep
1024 chunk_name, png_const_bytep data, png_size_t length));
1025
1026 /* Write the start of a PNG chunk - length and chunk name. */
1027 PNG_EXPORT(15, void, png_write_chunk_start, (png_structrp png_ptr,
1028 png_const_bytep chunk_name, png_uint_32 length));
1029
1030 /* Write the data of a PNG chunk started with png_write_chunk_start(). */
1031 PNG_EXPORT(16, void, png_write_chunk_data, (png_structrp png_ptr,
1032 png_const_bytep data, png_size_t length));
1033
1034 /* Finish a chunk started with png_write_chunk_start() (includes CRC). */
1035 PNG_EXPORT(17, void, png_write_chunk_end, (png_structrp png_ptr));
1036
1037 /* Allocate and initialize the info structure */
1038 PNG_EXPORTA(18, png_infop, png_create_info_struct, (png_const_structrp png_ptr),
1039 PNG_ALLOCATED);
1040
1041 /* DEPRECATED: this function allowed init structures to be created using the
1042 * default allocation method (typically malloc). Use is deprecated in 1.6.0 and
1043 * the API will be removed in the future.
1044 */
1045 PNG_EXPORTA(19, void, png_info_init_3, (png_infopp info_ptr,
1046 png_size_t png_info_struct_size), PNG_DEPRECATED);
1047
1048 /* Writes all the PNG information before the image. */
1049 PNG_EXPORT(20, void, png_write_info_before_PLTE,
1050 (png_structrp png_ptr, png_const_inforp info_ptr));
1051 PNG_EXPORT(21, void, png_write_info,
1052 (png_structrp png_ptr, png_const_inforp info_ptr));
1053
1054 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1055 /* Read the information before the actual image data. */
1056 PNG_EXPORT(22, void, png_read_info,
1057 (png_structrp png_ptr, png_inforp info_ptr));
1058 #endif
1059
1060 #ifdef PNG_TIME_RFC1123_SUPPORTED
1061 /* Convert to a US string format: there is no localization support in this
1062 * routine. The original implementation used a 29 character buffer in
1063 * png_struct, this will be removed in future versions.
1064 */
1065 #if PNG_LIBPNG_VER < 10700
1066 /* To do: remove this from libpng17 (and from libpng17/png.c and pngstruct.h) */
1067 PNG_EXPORTA(23, png_const_charp, png_convert_to_rfc1123, (png_structrp png_ptr,
1068 png_const_timep ptime),PNG_DEPRECATED);
1069 #endif
1070 PNG_EXPORT(241, int, png_convert_to_rfc1123_buffer, (char out[29],
1071 png_const_timep ptime));
1072 #endif
1073
1074 #ifdef PNG_CONVERT_tIME_SUPPORTED
1075 /* Convert from a struct tm to png_time */
1076 PNG_EXPORT(24, void, png_convert_from_struct_tm, (png_timep ptime,
1077 const struct tm * ttime));
1078
1079 /* Convert from time_t to png_time. Uses gmtime() */
1080 PNG_EXPORT(25, void, png_convert_from_time_t, (png_timep ptime, time_t ttime));
1081 #endif /* CONVERT_tIME */
1082
1083 #ifdef PNG_READ_EXPAND_SUPPORTED
1084 /* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
1085 PNG_EXPORT(26, void, png_set_expand, (png_structrp png_ptr));
1086 PNG_EXPORT(27, void, png_set_expand_gray_1_2_4_to_8, (png_structrp png_ptr));
1087 PNG_EXPORT(28, void, png_set_palette_to_rgb, (png_structrp png_ptr));
1088 PNG_EXPORT(29, void, png_set_tRNS_to_alpha, (png_structrp png_ptr));
1089 #endif
1090
1091 #ifdef PNG_READ_EXPAND_16_SUPPORTED
1092 /* Expand to 16-bit channels, forces conversion of palette to RGB and expansion
1093 * of a tRNS chunk if present.
1094 */
1095 PNG_EXPORT(221, void, png_set_expand_16, (png_structrp png_ptr));
1096 #endif
1097
1098 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
1099 /* Use blue, green, red order for pixels. */
1100 PNG_EXPORT(30, void, png_set_bgr, (png_structrp png_ptr));
1101 #endif
1102
1103 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
1104 /* Expand the grayscale to 24-bit RGB if necessary. */
1105 PNG_EXPORT(31, void, png_set_gray_to_rgb, (png_structrp png_ptr));
1106 #endif
1107
1108 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1109 /* Reduce RGB to grayscale. */
1110 #define PNG_ERROR_ACTION_NONE 1
1111 #define PNG_ERROR_ACTION_WARN 2
1112 #define PNG_ERROR_ACTION_ERROR 3
1113 #define PNG_RGB_TO_GRAY_DEFAULT (-1)/*for red/green coefficients*/
1114
1115 PNG_FP_EXPORT(32, void, png_set_rgb_to_gray, (png_structrp png_ptr,
1116 int error_action, double red, double green))
1117 PNG_FIXED_EXPORT(33, void, png_set_rgb_to_gray_fixed, (png_structrp png_ptr,
1118 int error_action, png_fixed_point red, png_fixed_point green))
1119
1120 PNG_EXPORT(34, png_byte, png_get_rgb_to_gray_status, (png_const_structrp
1121 png_ptr));
1122 #endif
1123
1124 #ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED
1125 PNG_EXPORT(35, void, png_build_grayscale_palette, (int bit_depth,
1126 png_colorp palette));
1127 #endif
1128
1129 #ifdef PNG_READ_ALPHA_MODE_SUPPORTED
1130 /* How the alpha channel is interpreted - this affects how the color channels
1131 * of a PNG file are returned to the calling application when an alpha channel,
1132 * or a tRNS chunk in a palette file, is present.
1133 *
1134 * This has no effect on the way pixels are written into a PNG output
1135 * datastream. The color samples in a PNG datastream are never premultiplied
1136 * with the alpha samples.
1137 *
1138 * The default is to return data according to the PNG specification: the alpha
1139 * channel is a linear measure of the contribution of the pixel to the
1140 * corresponding composited pixel, and the color channels are unassociated
1141 * (not premultiplied). The gamma encoded color channels must be scaled
1142 * according to the contribution and to do this it is necessary to undo
1143 * the encoding, scale the color values, perform the composition and reencode
1144 * the values. This is the 'PNG' mode.
1145 *
1146 * The alternative is to 'associate' the alpha with the color information by
1147 * storing color channel values that have been scaled by the alpha.
1148 * image. These are the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' modes
1149 * (the latter being the two common names for associated alpha color channels).
1150 *
1151 * For the 'OPTIMIZED' mode, a pixel is treated as opaque only if the alpha
1152 * value is equal to the maximum value.
1153 *
1154 * The final choice is to gamma encode the alpha channel as well. This is
1155 * broken because, in practice, no implementation that uses this choice
1156 * correctly undoes the encoding before handling alpha composition. Use this
1157 * choice only if other serious errors in the software or hardware you use
1158 * mandate it; the typical serious error is for dark halos to appear around
1159 * opaque areas of the composited PNG image because of arithmetic overflow.
1160 *
1161 * The API function png_set_alpha_mode specifies which of these choices to use
1162 * with an enumerated 'mode' value and the gamma of the required output:
1163 */
1164 #define PNG_ALPHA_PNG 0 /* according to the PNG standard */
1165 #define PNG_ALPHA_STANDARD 1 /* according to Porter/Duff */
1166 #define PNG_ALPHA_ASSOCIATED 1 /* as above; this is the normal practice */
1167 #define PNG_ALPHA_PREMULTIPLIED 1 /* as above */
1168 #define PNG_ALPHA_OPTIMIZED 2 /* 'PNG' for opaque pixels, else 'STANDARD' */
1169 #define PNG_ALPHA_BROKEN 3 /* the alpha channel is gamma encoded */
1170
1171 PNG_FP_EXPORT(227, void, png_set_alpha_mode, (png_structrp png_ptr, int mode,
1172 double output_gamma))
1173 PNG_FIXED_EXPORT(228, void, png_set_alpha_mode_fixed, (png_structrp png_ptr,
1174 int mode, png_fixed_point output_gamma))
1175 #endif
1176
1177 #if defined(PNG_GAMMA_SUPPORTED) || defined(PNG_READ_ALPHA_MODE_SUPPORTED)
1178 /* The output_gamma value is a screen gamma in libpng terminology: it expresses
1179 * how to decode the output values, not how they are encoded.
1180 */
1181 #define PNG_DEFAULT_sRGB -1 /* sRGB gamma and color space */
1182 #define PNG_GAMMA_MAC_18 -2 /* Old Mac '1.8' gamma and color space */
1183 #define PNG_GAMMA_sRGB 220000 /* Television standards--matches sRGB gamma */
1184 #define PNG_GAMMA_LINEAR PNG_FP_1 /* Linear */
1185 #endif
1186
1187 /* The following are examples of calls to png_set_alpha_mode to achieve the
1188 * required overall gamma correction and, where necessary, alpha
1189 * premultiplication.
1190 *
1191 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
1192 * This is the default libpng handling of the alpha channel - it is not
1193 * pre-multiplied into the color components. In addition the call states
1194 * that the output is for a sRGB system and causes all PNG files without gAMA
1195 * chunks to be assumed to be encoded using sRGB.
1196 *
1197 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
1198 * In this case the output is assumed to be something like an sRGB conformant
1199 * display preceeded by a power-law lookup table of power 1.45. This is how
1200 * early Mac systems behaved.
1201 *
1202 * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR);
1203 * This is the classic Jim Blinn approach and will work in academic
1204 * environments where everything is done by the book. It has the shortcoming
1205 * of assuming that input PNG data with no gamma information is linear - this
1206 * is unlikely to be correct unless the PNG files where generated locally.
1207 * Most of the time the output precision will be so low as to show
1208 * significant banding in dark areas of the image.
1209 *
1210 * png_set_expand_16(pp);
1211 * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB);
1212 * This is a somewhat more realistic Jim Blinn inspired approach. PNG files
1213 * are assumed to have the sRGB encoding if not marked with a gamma value and
1214 * the output is always 16 bits per component. This permits accurate scaling
1215 * and processing of the data. If you know that your input PNG files were
1216 * generated locally you might need to replace PNG_DEFAULT_sRGB with the
1217 * correct value for your system.
1218 *
1219 * png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB);
1220 * If you just need to composite the PNG image onto an existing background
1221 * and if you control the code that does this you can use the optimization
1222 * setting. In this case you just copy completely opaque pixels to the
1223 * output. For pixels that are not completely transparent (you just skip
1224 * those) you do the composition math using png_composite or png_composite_16
1225 * below then encode the resultant 8-bit or 16-bit values to match the output
1226 * encoding.
1227 *
1228 * Other cases
1229 * If neither the PNG nor the standard linear encoding work for you because
1230 * of the software or hardware you use then you have a big problem. The PNG
1231 * case will probably result in halos around the image. The linear encoding
1232 * will probably result in a washed out, too bright, image (it's actually too
1233 * contrasty.) Try the ALPHA_OPTIMIZED mode above - this will probably
1234 * substantially reduce the halos. Alternatively try:
1235 *
1236 * png_set_alpha_mode(pp, PNG_ALPHA_BROKEN, PNG_DEFAULT_sRGB);
1237 * This option will also reduce the halos, but there will be slight dark
1238 * halos round the opaque parts of the image where the background is light.
1239 * In the OPTIMIZED mode the halos will be light halos where the background
1240 * is dark. Take your pick - the halos are unavoidable unless you can get
1241 * your hardware/software fixed! (The OPTIMIZED approach is slightly
1242 * faster.)
1243 *
1244 * When the default gamma of PNG files doesn't match the output gamma.
1245 * If you have PNG files with no gamma information png_set_alpha_mode allows
1246 * you to provide a default gamma, but it also sets the ouput gamma to the
1247 * matching value. If you know your PNG files have a gamma that doesn't
1248 * match the output you can take advantage of the fact that
1249 * png_set_alpha_mode always sets the output gamma but only sets the PNG
1250 * default if it is not already set:
1251 *
1252 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
1253 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
1254 * The first call sets both the default and the output gamma values, the
1255 * second call overrides the output gamma without changing the default. This
1256 * is easier than achieving the same effect with png_set_gamma. You must use
1257 * PNG_ALPHA_PNG for the first call - internal checking in png_set_alpha will
1258 * fire if more than one call to png_set_alpha_mode and png_set_background is
1259 * made in the same read operation, however multiple calls with PNG_ALPHA_PNG
1260 * are ignored.
1261 */
1262
1263 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
1264 PNG_EXPORT(36, void, png_set_strip_alpha, (png_structrp png_ptr));
1265 #endif
1266
1267 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
1268 defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
1269 PNG_EXPORT(37, void, png_set_swap_alpha, (png_structrp png_ptr));
1270 #endif
1271
1272 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
1273 defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
1274 PNG_EXPORT(38, void, png_set_invert_alpha, (png_structrp png_ptr));
1275 #endif
1276
1277 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
1278 /* Add a filler byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */
1279 PNG_EXPORT(39, void, png_set_filler, (png_structrp png_ptr, png_uint_32 filler,
1280 int flags));
1281 /* The values of the PNG_FILLER_ defines should NOT be changed */
1282 # define PNG_FILLER_BEFORE 0
1283 # define PNG_FILLER_AFTER 1
1284 /* Add an alpha byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */
1285 PNG_EXPORT(40, void, png_set_add_alpha, (png_structrp png_ptr,
1286 png_uint_32 filler, int flags));
1287 #endif /* READ_FILLER || WRITE_FILLER */
1288
1289 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
1290 /* Swap bytes in 16-bit depth files. */
1291 PNG_EXPORT(41, void, png_set_swap, (png_structrp png_ptr));
1292 #endif
1293
1294 #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
1295 /* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
1296 PNG_EXPORT(42, void, png_set_packing, (png_structrp png_ptr));
1297 #endif
1298
1299 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
1300 defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1301 /* Swap packing order of pixels in bytes. */
1302 PNG_EXPORT(43, void, png_set_packswap, (png_structrp png_ptr));
1303 #endif
1304
1305 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
1306 /* Converts files to legal bit depths. */
1307 PNG_EXPORT(44, void, png_set_shift, (png_structrp png_ptr, png_const_color_8p
1308 true_bits));
1309 #endif
1310
1311 #if defined(PNG_READ_INTERLACING_SUPPORTED) || \
1312 defined(PNG_WRITE_INTERLACING_SUPPORTED)
1313 /* Have the code handle the interlacing. Returns the number of passes.
1314 * MUST be called before png_read_update_info or png_start_read_image,
1315 * otherwise it will not have the desired effect. Note that it is still
1316 * necessary to call png_read_row or png_read_rows png_get_image_height
1317 * times for each pass.
1318 */
1319 PNG_EXPORT(45, int, png_set_interlace_handling, (png_structrp png_ptr));
1320 #endif
1321
1322 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
1323 /* Invert monochrome files */
1324 PNG_EXPORT(46, void, png_set_invert_mono, (png_structrp png_ptr));
1325 #endif
1326
1327 #ifdef PNG_READ_BACKGROUND_SUPPORTED
1328 /* Handle alpha and tRNS by replacing with a background color. Prior to
1329 * libpng-1.5.4 this API must not be called before the PNG file header has been
1330 * read. Doing so will result in unexpected behavior and possible warnings or
1331 * errors if the PNG file contains a bKGD chunk.
1332 */
1333 PNG_FP_EXPORT(47, void, png_set_background, (png_structrp png_ptr,
1334 png_const_color_16p background_color, int background_gamma_code,
1335 int need_expand, double background_gamma))
1336 PNG_FIXED_EXPORT(215, void, png_set_background_fixed, (png_structrp png_ptr,
1337 png_const_color_16p background_color, int background_gamma_code,
1338 int need_expand, png_fixed_point background_gamma))
1339 #endif
1340 #ifdef PNG_READ_BACKGROUND_SUPPORTED
1341 # define PNG_BACKGROUND_GAMMA_UNKNOWN 0
1342 # define PNG_BACKGROUND_GAMMA_SCREEN 1
1343 # define PNG_BACKGROUND_GAMMA_FILE 2
1344 # define PNG_BACKGROUND_GAMMA_UNIQUE 3
1345 #endif
1346
1347 #ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
1348 /* Scale a 16-bit depth file down to 8-bit, accurately. */
1349 PNG_EXPORT(229, void, png_set_scale_16, (png_structrp png_ptr));
1350 #endif
1351
1352 #ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
1353 #define PNG_READ_16_TO_8 SUPPORTED /* Name prior to 1.5.4 */
1354 /* Strip the second byte of information from a 16-bit depth file. */
1355 PNG_EXPORT(48, void, png_set_strip_16, (png_structrp png_ptr));
1356 #endif
1357
1358 #ifdef PNG_READ_QUANTIZE_SUPPORTED
1359 /* Turn on quantizing, and reduce the palette to the number of colors
1360 * available.
1361 */
1362 PNG_EXPORT(49, void, png_set_quantize, (png_structrp png_ptr,
1363 png_colorp palette, int num_palette, int maximum_colors,
1364 png_const_uint_16p histogram, int full_quantize));
1365 #endif
1366
1367 #ifdef PNG_READ_GAMMA_SUPPORTED
1368 /* The threshold on gamma processing is configurable but hard-wired into the
1369 * library. The following is the floating point variant.
1370 */
1371 #define PNG_GAMMA_THRESHOLD (PNG_GAMMA_THRESHOLD_FIXED*.00001)
1372
1373 /* Handle gamma correction. Screen_gamma=(display_exponent).
1374 * NOTE: this API simply sets the screen and file gamma values. It will
1375 * therefore override the value for gamma in a PNG file if it is called after
1376 * the file header has been read - use with care - call before reading the PNG
1377 * file for best results!
1378 *
1379 * These routines accept the same gamma values as png_set_alpha_mode (described
1380 * above). The PNG_GAMMA_ defines and PNG_DEFAULT_sRGB can be passed to either
1381 * API (floating point or fixed.) Notice, however, that the 'file_gamma' value
1382 * is the inverse of a 'screen gamma' value.
1383 */
1384 PNG_FP_EXPORT(50, void, png_set_gamma, (png_structrp png_ptr,
1385 double screen_gamma, double override_file_gamma))
1386 PNG_FIXED_EXPORT(208, void, png_set_gamma_fixed, (png_structrp png_ptr,
1387 png_fixed_point screen_gamma, png_fixed_point override_file_gamma))
1388 #endif
1389
1390 #ifdef PNG_WRITE_FLUSH_SUPPORTED
1391 /* Set how many lines between output flushes - 0 for no flushing */
1392 PNG_EXPORT(51, void, png_set_flush, (png_structrp png_ptr, int nrows));
1393 /* Flush the current PNG output buffer */
1394 PNG_EXPORT(52, void, png_write_flush, (png_structrp png_ptr));
1395 #endif
1396
1397 /* Optional update palette with requested transformations */
1398 PNG_EXPORT(53, void, png_start_read_image, (png_structrp png_ptr));
1399
1400 /* Optional call to update the users info structure */
1401 PNG_EXPORT(54, void, png_read_update_info, (png_structrp png_ptr,
1402 png_inforp info_ptr));
1403
1404 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1405 /* Read one or more rows of image data. */
1406 PNG_EXPORT(55, void, png_read_rows, (png_structrp png_ptr, png_bytepp row,
1407 png_bytepp display_row, png_uint_32 num_rows));
1408 #endif
1409
1410 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1411 /* Read a row of data. */
1412 PNG_EXPORT(56, void, png_read_row, (png_structrp png_ptr, png_bytep row,
1413 png_bytep display_row));
1414 #endif
1415
1416 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1417 /* Read the whole image into memory at once. */
1418 PNG_EXPORT(57, void, png_read_image, (png_structrp png_ptr, png_bytepp image));
1419 #endif
1420
1421 /* Write a row of image data */
1422 PNG_EXPORT(58, void, png_write_row, (png_structrp png_ptr,
1423 png_const_bytep row));
1424
1425 /* Write a few rows of image data: (*row) is not written; however, the type
1426 * is declared as writeable to maintain compatibility with previous versions
1427 * of libpng and to allow the 'display_row' array from read_rows to be passed
1428 * unchanged to write_rows.
1429 */
1430 PNG_EXPORT(59, void, png_write_rows, (png_structrp png_ptr, png_bytepp row,
1431 png_uint_32 num_rows));
1432
1433 /* Write the image data */
1434 PNG_EXPORT(60, void, png_write_image, (png_structrp png_ptr, png_bytepp image));
1435
1436 /* Write the end of the PNG file. */
1437 PNG_EXPORT(61, void, png_write_end, (png_structrp png_ptr,
1438 png_inforp info_ptr));
1439
1440 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1441 /* Read the end of the PNG file. */
1442 PNG_EXPORT(62, void, png_read_end, (png_structrp png_ptr, png_inforp info_ptr));
1443 #endif
1444
1445 /* Free any memory associated with the png_info_struct */
1446 PNG_EXPORT(63, void, png_destroy_info_struct, (png_const_structrp png_ptr,
1447 png_infopp info_ptr_ptr));
1448
1449 /* Free any memory associated with the png_struct and the png_info_structs */
1450 PNG_EXPORT(64, void, png_destroy_read_struct, (png_structpp png_ptr_ptr,
1451 png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr));
1452
1453 /* Free any memory associated with the png_struct and the png_info_structs */
1454 PNG_EXPORT(65, void, png_destroy_write_struct, (png_structpp png_ptr_ptr,
1455 png_infopp info_ptr_ptr));
1456
1457 /* Set the libpng method of handling chunk CRC errors */
1458 PNG_EXPORT(66, void, png_set_crc_action, (png_structrp png_ptr, int crit_action,
1459 int ancil_action));
1460
1461 /* Values for png_set_crc_action() say how to handle CRC errors in
1462 * ancillary and critical chunks, and whether to use the data contained
1463 * therein. Note that it is impossible to "discard" data in a critical
1464 * chunk. For versions prior to 0.90, the action was always error/quit,
1465 * whereas in version 0.90 and later, the action for CRC errors in ancillary
1466 * chunks is warn/discard. These values should NOT be changed.
1467 *
1468 * value action:critical action:ancillary
1469 */
1470 #define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */
1471 #define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */
1472 #define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */
1473 #define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */
1474 #define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */
1475 #define PNG_CRC_NO_CHANGE 5 /* use current value use current value */
1476
1477 #ifdef PNG_WRITE_SUPPORTED
1478 /* These functions give the user control over the scan-line filtering in
1479 * libpng and the compression methods used by zlib. These functions are
1480 * mainly useful for testing, as the defaults should work with most users.
1481 * Those users who are tight on memory or want faster performance at the
1482 * expense of compression can modify them. See the compression library
1483 * header file (zlib.h) for an explination of the compression functions.
1484 */
1485
1486 /* Set the filtering method(s) used by libpng. Currently, the only valid
1487 * value for "method" is 0.
1488 */
1489 PNG_EXPORT(67, void, png_set_filter, (png_structrp png_ptr, int method,
1490 int filters));
1491 #endif /* WRITE */
1492
1493 /* Flags for png_set_filter() to say which filters to use. The flags
1494 * are chosen so that they don't conflict with real filter types
1495 * below, in case they are supplied instead of the #defined constants.
1496 * These values should NOT be changed.
1497 */
1498 #define PNG_NO_FILTERS 0x00
1499 #define PNG_FILTER_NONE 0x08
1500 #define PNG_FILTER_SUB 0x10
1501 #define PNG_FILTER_UP 0x20
1502 #define PNG_FILTER_AVG 0x40
1503 #define PNG_FILTER_PAETH 0x80
1504 #define PNG_ALL_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP | \
1505 PNG_FILTER_AVG | PNG_FILTER_PAETH)
1506
1507 /* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
1508 * These defines should NOT be changed.
1509 */
1510 #define PNG_FILTER_VALUE_NONE 0
1511 #define PNG_FILTER_VALUE_SUB 1
1512 #define PNG_FILTER_VALUE_UP 2
1513 #define PNG_FILTER_VALUE_AVG 3
1514 #define PNG_FILTER_VALUE_PAETH 4
1515 #define PNG_FILTER_VALUE_LAST 5
1516
1517 #ifdef PNG_WRITE_SUPPORTED
1518 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* DEPRECATED */
1519 PNG_FP_EXPORT(68, void, png_set_filter_heuristics, (png_structrp png_ptr,
1520 int heuristic_method, int num_weights, png_const_doublep filter_weights,
1521 png_const_doublep filter_costs))
1522 PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed,
1523 (png_structrp png_ptr, int heuristic_method, int num_weights,
1524 png_const_fixed_point_p filter_weights,
1525 png_const_fixed_point_p filter_costs))
1526 #endif /* WRITE_WEIGHTED_FILTER */
1527
1528 /* The following are no longer used and will be removed from libpng-1.7: */
1529 #define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */
1530 #define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */
1531 #define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */
1532 #define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */
1533
1534 /* Set the library compression level. Currently, valid values range from
1535 * 0 - 9, corresponding directly to the zlib compression levels 0 - 9
1536 * (0 - no compression, 9 - "maximal" compression). Note that tests have
1537 * shown that zlib compression levels 3-6 usually perform as well as level 9
1538 * for PNG images, and do considerably fewer caclulations. In the future,
1539 * these values may not correspond directly to the zlib compression levels.
1540 */
1541 #ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED
1542 PNG_EXPORT(69, void, png_set_compression_level, (png_structrp png_ptr,
1543 int level));
1544
1545 PNG_EXPORT(70, void, png_set_compression_mem_level, (png_structrp png_ptr,
1546 int mem_level));
1547
1548 PNG_EXPORT(71, void, png_set_compression_strategy, (png_structrp png_ptr,
1549 int strategy));
1550
1551 /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
1552 * smaller value of window_bits if it can do so safely.
1553 */
1554 PNG_EXPORT(72, void, png_set_compression_window_bits, (png_structrp png_ptr,
1555 int window_bits));
1556
1557 PNG_EXPORT(73, void, png_set_compression_method, (png_structrp png_ptr,
1558 int method));
1559 #endif /* WRITE_CUSTOMIZE_COMPRESSION */
1560
1561 #ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
1562 /* Also set zlib parameters for compressing non-IDAT chunks */
1563 PNG_EXPORT(222, void, png_set_text_compression_level, (png_structrp png_ptr,
1564 int level));
1565
1566 PNG_EXPORT(223, void, png_set_text_compression_mem_level, (png_structrp png_ptr,
1567 int mem_level));
1568
1569 PNG_EXPORT(224, void, png_set_text_compression_strategy, (png_structrp png_ptr,
1570 int strategy));
1571
1572 /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
1573 * smaller value of window_bits if it can do so safely.
1574 */
1575 PNG_EXPORT(225, void, png_set_text_compression_window_bits,
1576 (png_structrp png_ptr, int window_bits));
1577
1578 PNG_EXPORT(226, void, png_set_text_compression_method, (png_structrp png_ptr,
1579 int method));
1580 #endif /* WRITE_CUSTOMIZE_ZTXT_COMPRESSION */
1581 #endif /* WRITE */
1582
1583 /* These next functions are called for input/output, memory, and error
1584 * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c,
1585 * and call standard C I/O routines such as fread(), fwrite(), and
1586 * fprintf(). These functions can be made to use other I/O routines
1587 * at run time for those applications that need to handle I/O in a
1588 * different manner by calling png_set_???_fn(). See libpng-manual.txt for
1589 * more information.
1590 */
1591
1592 #ifdef PNG_STDIO_SUPPORTED
1593 /* Initialize the input/output for the PNG file to the default functions. */
1594 PNG_EXPORT(74, void, png_init_io, (png_structrp png_ptr, png_FILE_p fp));
1595 #endif
1596
1597 /* Replace the (error and abort), and warning functions with user
1598 * supplied functions. If no messages are to be printed you must still
1599 * write and use replacement functions. The replacement error_fn should
1600 * still do a longjmp to the last setjmp location if you are using this
1601 * method of error handling. If error_fn or warning_fn is NULL, the
1602 * default function will be used.
1603 */
1604
1605 PNG_EXPORT(75, void, png_set_error_fn, (png_structrp png_ptr,
1606 png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn));
1607
1608 /* Return the user pointer associated with the error functions */
1609 PNG_EXPORT(76, png_voidp, png_get_error_ptr, (png_const_structrp png_ptr));
1610
1611 /* Replace the default data output functions with a user supplied one(s).
1612 * If buffered output is not used, then output_flush_fn can be set to NULL.
1613 * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time
1614 * output_flush_fn will be ignored (and thus can be NULL).
1615 * It is probably a mistake to use NULL for output_flush_fn if
1616 * write_data_fn is not also NULL unless you have built libpng with
1617 * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's
1618 * default flush function, which uses the standard *FILE structure, will
1619 * be used.
1620 */
1621 PNG_EXPORT(77, void, png_set_write_fn, (png_structrp png_ptr, png_voidp io_ptr,
1622 png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn));
1623
1624 /* Replace the default data input function with a user supplied one. */
1625 PNG_EXPORT(78, void, png_set_read_fn, (png_structrp png_ptr, png_voidp io_ptr,
1626 png_rw_ptr read_data_fn));
1627
1628 /* Return the user pointer associated with the I/O functions */
1629 PNG_EXPORT(79, png_voidp, png_get_io_ptr, (png_const_structrp png_ptr));
1630
1631 PNG_EXPORT(80, void, png_set_read_status_fn, (png_structrp png_ptr,
1632 png_read_status_ptr read_row_fn));
1633
1634 PNG_EXPORT(81, void, png_set_write_status_fn, (png_structrp png_ptr,
1635 png_write_status_ptr write_row_fn));
1636
1637 #ifdef PNG_USER_MEM_SUPPORTED
1638 /* Replace the default memory allocation functions with user supplied one(s). */
1639 PNG_EXPORT(82, void, png_set_mem_fn, (png_structrp png_ptr, png_voidp mem_ptr,
1640 png_malloc_ptr malloc_fn, png_free_ptr free_fn));
1641 /* Return the user pointer associated with the memory functions */
1642 PNG_EXPORT(83, png_voidp, png_get_mem_ptr, (png_const_structrp png_ptr));
1643 #endif
1644
1645 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
1646 PNG_EXPORT(84, void, png_set_read_user_transform_fn, (png_structrp png_ptr,
1647 png_user_transform_ptr read_user_transform_fn));
1648 #endif
1649
1650 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
1651 PNG_EXPORT(85, void, png_set_write_user_transform_fn, (png_structrp png_ptr,
1652 png_user_transform_ptr write_user_transform_fn));
1653 #endif
1654
1655 #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
1656 PNG_EXPORT(86, void, png_set_user_transform_info, (png_structrp png_ptr,
1657 png_voidp user_transform_ptr, int user_transform_depth,
1658 int user_transform_channels));
1659 /* Return the user pointer associated with the user transform functions */
1660 PNG_EXPORT(87, png_voidp, png_get_user_transform_ptr,
1661 (png_const_structrp png_ptr));
1662 #endif
1663
1664 #ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED
1665 /* Return information about the row currently being processed. Note that these
1666 * APIs do not fail but will return unexpected results if called outside a user
1667 * transform callback. Also note that when transforming an interlaced image the
1668 * row number is the row number within the sub-image of the interlace pass, so
1669 * the value will increase to the height of the sub-image (not the full image)
1670 * then reset to 0 for the next pass.
1671 *
1672 * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
1673 * find the output pixel (x,y) given an interlaced sub-image pixel
1674 * (row,col,pass). (See below for these macros.)
1675 */
1676 PNG_EXPORT(217, png_uint_32, png_get_current_row_number, (png_const_structrp));
1677 PNG_EXPORT(218, png_byte, png_get_current_pass_number, (png_const_structrp));
1678 #endif
1679
1680 #ifdef PNG_READ_USER_CHUNKS_SUPPORTED
1681 /* This callback is called only for *unknown* chunks. If
1682 * PNG_HANDLE_AS_UNKNOWN_SUPPORTED is set then it is possible to set known
1683 * chunks to be treated as unknown, however in this case the callback must do
1684 * any processing required by the chunk (e.g. by calling the appropriate
1685 * png_set_ APIs.)
1686 *
1687 * There is no write support - on write, by default, all the chunks in the
1688 * 'unknown' list are written in the specified position.
1689 *
1690 * The integer return from the callback function is interpreted thus:
1691 *
1692 * negative: An error occurred; png_chunk_error will be called.
1693 * zero: The chunk was not handled, the chunk will be saved. A critical
1694 * chunk will cause an error at this point unless it is to be saved.
1695 * positive: The chunk was handled, libpng will ignore/discard it.
1696 *
1697 * See "INTERACTION WTIH USER CHUNK CALLBACKS" below for important notes about
1698 * how this behavior will change in libpng 1.7
1699 */
1700 PNG_EXPORT(88, void, png_set_read_user_chunk_fn, (png_structrp png_ptr,
1701 png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));
1702 #endif
1703
1704 #ifdef PNG_USER_CHUNKS_SUPPORTED
1705 PNG_EXPORT(89, png_voidp, png_get_user_chunk_ptr, (png_const_structrp png_ptr));
1706 #endif
1707
1708 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1709 /* Sets the function callbacks for the push reader, and a pointer to a
1710 * user-defined structure available to the callback functions.
1711 */
1712 PNG_EXPORT(90, void, png_set_progressive_read_fn, (png_structrp png_ptr,
1713 png_voidp progressive_ptr, png_progressive_info_ptr info_fn,
1714 png_progressive_row_ptr row_fn, png_progressive_end_ptr end_fn));
1715
1716 /* Returns the user pointer associated with the push read functions */
1717 PNG_EXPORT(91, png_voidp, png_get_progressive_ptr,
1718 (png_const_structrp png_ptr));
1719
1720 /* Function to be called when data becomes available */
1721 PNG_EXPORT(92, void, png_process_data, (png_structrp png_ptr,
1722 png_inforp info_ptr, png_bytep buffer, png_size_t buffer_size));
1723
1724 /* A function which may be called *only* within png_process_data to stop the
1725 * processing of any more data. The function returns the number of bytes
1726 * remaining, excluding any that libpng has cached internally. A subsequent
1727 * call to png_process_data must supply these bytes again. If the argument
1728 * 'save' is set to true the routine will first save all the pending data and
1729 * will always return 0.
1730 */
1731 PNG_EXPORT(219, png_size_t, png_process_data_pause, (png_structrp, int save));
1732
1733 /* A function which may be called *only* outside (after) a call to
1734 * png_process_data. It returns the number of bytes of data to skip in the
1735 * input. Normally it will return 0, but if it returns a non-zero value the
1736 * application must skip than number of bytes of input data and pass the
1737 * following data to the next call to png_process_data.
1738 */
1739 PNG_EXPORT(220, png_uint_32, png_process_data_skip, (png_structrp));
1740
1741 /* Function that combines rows. 'new_row' is a flag that should come from
1742 * the callback and be non-NULL if anything needs to be done; the library
1743 * stores its own version of the new data internally and ignores the passed
1744 * in value.
1745 */
1746 PNG_EXPORT(93, void, png_progressive_combine_row, (png_const_structrp png_ptr,
1747 png_bytep old_row, png_const_bytep new_row));
1748 #endif /* PROGRESSIVE_READ */
1749
1750 PNG_EXPORTA(94, png_voidp, png_malloc, (png_const_structrp png_ptr,
1751 png_alloc_size_t size), PNG_ALLOCATED);
1752 /* Added at libpng version 1.4.0 */
1753 PNG_EXPORTA(95, png_voidp, png_calloc, (png_const_structrp png_ptr,
1754 png_alloc_size_t size), PNG_ALLOCATED);
1755
1756 /* Added at libpng version 1.2.4 */
1757 PNG_EXPORTA(96, png_voidp, png_malloc_warn, (png_const_structrp png_ptr,
1758 png_alloc_size_t size), PNG_ALLOCATED);
1759
1760 /* Frees a pointer allocated by png_malloc() */
1761 PNG_EXPORT(97, void, png_free, (png_const_structrp png_ptr, png_voidp ptr));
1762
1763 /* Free data that was allocated internally */
1764 PNG_EXPORT(98, void, png_free_data, (png_const_structrp png_ptr,
1765 png_inforp info_ptr, png_uint_32 free_me, int num));
1766
1767 /* Reassign responsibility for freeing existing data, whether allocated
1768 * by libpng or by the application; this works on the png_info structure passed
1769 * in, it does not change the state for other png_info structures.
1770 *
1771 * It is unlikely that this function works correctly as of 1.6.0 and using it
1772 * may result either in memory leaks or double free of allocated data.
1773 */
1774 PNG_EXPORT(99, void, png_data_freer, (png_const_structrp png_ptr,
1775 png_inforp info_ptr, int freer, png_uint_32 mask));
1776
1777 /* Assignments for png_data_freer */
1778 #define PNG_DESTROY_WILL_FREE_DATA 1
1779 #define PNG_SET_WILL_FREE_DATA 1
1780 #define PNG_USER_WILL_FREE_DATA 2
1781 /* Flags for png_ptr->free_me and info_ptr->free_me */
1782 #define PNG_FREE_HIST 0x0008
1783 #define PNG_FREE_ICCP 0x0010
1784 #define PNG_FREE_SPLT 0x0020
1785 #define PNG_FREE_ROWS 0x0040
1786 #define PNG_FREE_PCAL 0x0080
1787 #define PNG_FREE_SCAL 0x0100
1788 #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
1789 # define PNG_FREE_UNKN 0x0200
1790 #endif
1791 /* PNG_FREE_LIST 0x0400 removed in 1.6.0 because it is ignored */
1792 #define PNG_FREE_PLTE 0x1000
1793 #define PNG_FREE_TRNS 0x2000
1794 #define PNG_FREE_TEXT 0x4000
1795 #define PNG_FREE_ALL 0x7fff
1796 #define PNG_FREE_MUL 0x4220 /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */
1797
1798 #ifdef PNG_USER_MEM_SUPPORTED
1799 PNG_EXPORTA(100, png_voidp, png_malloc_default, (png_const_structrp png_ptr,
1800 png_alloc_size_t size), PNG_ALLOCATED PNG_DEPRECATED);
1801 PNG_EXPORTA(101, void, png_free_default, (png_const_structrp png_ptr,
1802 png_voidp ptr), PNG_DEPRECATED);
1803 #endif
1804
1805 #ifdef PNG_ERROR_TEXT_SUPPORTED
1806 /* Fatal error in PNG image of libpng - can't continue */
1807 PNG_EXPORTA(102, void, png_error, (png_const_structrp png_ptr,
1808 png_const_charp error_message), PNG_NORETURN);
1809
1810 /* The same, but the chunk name is prepended to the error string. */
1811 PNG_EXPORTA(103, void, png_chunk_error, (png_const_structrp png_ptr,
1812 png_const_charp error_message), PNG_NORETURN);
1813
1814 #else
1815 /* Fatal error in PNG image of libpng - can't continue */
1816 PNG_EXPORTA(104, void, png_err, (png_const_structrp png_ptr), PNG_NORETURN);
1817 # define png_error(s1,s2) png_err(s1)
1818 # define png_chunk_error(s1,s2) png_err(s1)
1819 #endif
1820
1821 #ifdef PNG_WARNINGS_SUPPORTED
1822 /* Non-fatal error in libpng. Can continue, but may have a problem. */
1823 PNG_EXPORT(105, void, png_warning, (png_const_structrp png_ptr,
1824 png_const_charp warning_message));
1825
1826 /* Non-fatal error in libpng, chunk name is prepended to message. */
1827 PNG_EXPORT(106, void, png_chunk_warning, (png_const_structrp png_ptr,
1828 png_const_charp warning_message));
1829 #else
1830 # define png_warning(s1,s2) ((void)(s1))
1831 # define png_chunk_warning(s1,s2) ((void)(s1))
1832 #endif
1833
1834 #ifdef PNG_BENIGN_ERRORS_SUPPORTED
1835 /* Benign error in libpng. Can continue, but may have a problem.
1836 * User can choose whether to handle as a fatal error or as a warning. */
1837 PNG_EXPORT(107, void, png_benign_error, (png_const_structrp png_ptr,
1838 png_const_charp warning_message));
1839
1840 #ifdef PNG_READ_SUPPORTED
1841 /* Same, chunk name is prepended to message (only during read) */
1842 PNG_EXPORT(108, void, png_chunk_benign_error, (png_const_structrp png_ptr,
1843 png_const_charp warning_message));
1844 #endif
1845
1846 PNG_EXPORT(109, void, png_set_benign_errors,
1847 (png_structrp png_ptr, int allowed));
1848 #else
1849 # ifdef PNG_ALLOW_BENIGN_ERRORS
1850 # define png_benign_error png_warning
1851 # define png_chunk_benign_error png_chunk_warning
1852 # else
1853 # define png_benign_error png_error
1854 # define png_chunk_benign_error png_chunk_error
1855 # endif
1856 #endif
1857
1858 /* The png_set_<chunk> functions are for storing values in the png_info_struct.
1859 * Similarly, the png_get_<chunk> calls are used to read values from the
1860 * png_info_struct, either storing the parameters in the passed variables, or
1861 * setting pointers into the png_info_struct where the data is stored. The
1862 * png_get_<chunk> functions return a non-zero value if the data was available
1863 * in info_ptr, or return zero and do not change any of the parameters if the
1864 * data was not available.
1865 *
1866 * These functions should be used instead of directly accessing png_info
1867 * to avoid problems with future changes in the size and internal layout of
1868 * png_info_struct.
1869 */
1870 /* Returns "flag" if chunk data is valid in info_ptr. */
1871 PNG_EXPORT(110, png_uint_32, png_get_valid, (png_const_structrp png_ptr,
1872 png_const_inforp info_ptr, png_uint_32 flag));
1873
1874 /* Returns number of bytes needed to hold a transformed row. */
1875 PNG_EXPORT(111, png_size_t, png_get_rowbytes, (png_const_structrp png_ptr,
1876 png_const_inforp info_ptr));
1877
1878 #ifdef PNG_INFO_IMAGE_SUPPORTED
1879 /* Returns row_pointers, which is an array of pointers to scanlines that was
1880 * returned from png_read_png().
1881 */
1882 PNG_EXPORT(112, png_bytepp, png_get_rows, (png_const_structrp png_ptr,
1883 png_const_inforp info_ptr));
1884
1885 /* Set row_pointers, which is an array of pointers to scanlines for use
1886 * by png_write_png().
1887 */
1888 PNG_EXPORT(113, void, png_set_rows, (png_const_structrp png_ptr,
1889 png_inforp info_ptr, png_bytepp row_pointers));
1890 #endif
1891
1892 /* Returns number of color channels in image. */
1893 PNG_EXPORT(114, png_byte, png_get_channels, (png_const_structrp png_ptr,
1894 png_const_inforp info_ptr));
1895
1896 #ifdef PNG_EASY_ACCESS_SUPPORTED
1897 /* Returns image width in pixels. */
1898 PNG_EXPORT(115, png_uint_32, png_get_image_width, (png_const_structrp png_ptr,
1899 png_const_inforp info_ptr));
1900
1901 /* Returns image height in pixels. */
1902 PNG_EXPORT(116, png_uint_32, png_get_image_height, (png_const_structrp png_ptr,
1903 png_const_inforp info_ptr));
1904
1905 /* Returns image bit_depth. */
1906 PNG_EXPORT(117, png_byte, png_get_bit_depth, (png_const_structrp png_ptr,
1907 png_const_inforp info_ptr));
1908
1909 /* Returns image color_type. */
1910 PNG_EXPORT(118, png_byte, png_get_color_type, (png_const_structrp png_ptr,
1911 png_const_inforp info_ptr));
1912
1913 /* Returns image filter_type. */
1914 PNG_EXPORT(119, png_byte, png_get_filter_type, (png_const_structrp png_ptr,
1915 png_const_inforp info_ptr));
1916
1917 /* Returns image interlace_type. */
1918 PNG_EXPORT(120, png_byte, png_get_interlace_type, (png_const_structrp png_ptr,
1919 png_const_inforp info_ptr));
1920
1921 /* Returns image compression_type. */
1922 PNG_EXPORT(121, png_byte, png_get_compression_type, (png_const_structrp png_ptr,
1923 png_const_inforp info_ptr));
1924
1925 /* Returns image resolution in pixels per meter, from pHYs chunk data. */
1926 PNG_EXPORT(122, png_uint_32, png_get_pixels_per_meter,
1927 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1928 PNG_EXPORT(123, png_uint_32, png_get_x_pixels_per_meter,
1929 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1930 PNG_EXPORT(124, png_uint_32, png_get_y_pixels_per_meter,
1931 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1932
1933 /* Returns pixel aspect ratio, computed from pHYs chunk data. */
1934 PNG_FP_EXPORT(125, float, png_get_pixel_aspect_ratio,
1935 (png_const_structrp png_ptr, png_const_inforp info_ptr))
1936 PNG_FIXED_EXPORT(210, png_fixed_point, png_get_pixel_aspect_ratio_fixed,
1937 (png_const_structrp png_ptr, png_const_inforp info_ptr))
1938
1939 /* Returns image x, y offset in pixels or microns, from oFFs chunk data. */
1940 PNG_EXPORT(126, png_int_32, png_get_x_offset_pixels,
1941 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1942 PNG_EXPORT(127, png_int_32, png_get_y_offset_pixels,
1943 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1944 PNG_EXPORT(128, png_int_32, png_get_x_offset_microns,
1945 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1946 PNG_EXPORT(129, png_int_32, png_get_y_offset_microns,
1947 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1948
1949 #endif /* EASY_ACCESS */
1950
1951 #ifdef PNG_READ_SUPPORTED
1952 /* Returns pointer to signature string read from PNG header */
1953 PNG_EXPORT(130, png_const_bytep, png_get_signature, (png_const_structrp png_ptr,
1954 png_const_inforp info_ptr));
1955 #endif
1956
1957 #ifdef PNG_bKGD_SUPPORTED
1958 PNG_EXPORT(131, png_uint_32, png_get_bKGD, (png_const_structrp png_ptr,
1959 png_inforp info_ptr, png_color_16p *background));
1960 #endif
1961
1962 #ifdef PNG_bKGD_SUPPORTED
1963 PNG_EXPORT(132, void, png_set_bKGD, (png_const_structrp png_ptr,
1964 png_inforp info_ptr, png_const_color_16p background));
1965 #endif
1966
1967 #ifdef PNG_cHRM_SUPPORTED
1968 PNG_FP_EXPORT(133, png_uint_32, png_get_cHRM, (png_const_structrp png_ptr,
1969 png_const_inforp info_ptr, double *white_x, double *white_y, double *red_x,
1970 double *red_y, double *green_x, double *green_y, double *blue_x,
1971 double *blue_y))
1972 PNG_FP_EXPORT(230, png_uint_32, png_get_cHRM_XYZ, (png_const_structrp png_ptr,
1973 png_const_inforp info_ptr, double *red_X, double *red_Y, double *red_Z,
1974 double *green_X, double *green_Y, double *green_Z, double *blue_X,
1975 double *blue_Y, double *blue_Z))
1976 PNG_FIXED_EXPORT(134, png_uint_32, png_get_cHRM_fixed,
1977 (png_const_structrp png_ptr, png_const_inforp info_ptr,
1978 png_fixed_point *int_white_x, png_fixed_point *int_white_y,
1979 png_fixed_point *int_red_x, png_fixed_point *int_red_y,
1980 png_fixed_point *int_green_x, png_fixed_point *int_green_y,
1981 png_fixed_point *int_blue_x, png_fixed_point *int_blue_y))
1982 PNG_FIXED_EXPORT(231, png_uint_32, png_get_cHRM_XYZ_fixed,
1983 (png_const_structrp png_ptr, png_const_inforp info_ptr,
1984 png_fixed_point *int_red_X, png_fixed_point *int_red_Y,
1985 png_fixed_point *int_red_Z, png_fixed_point *int_green_X,
1986 png_fixed_point *int_green_Y, png_fixed_point *int_green_Z,
1987 png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y,
1988 png_fixed_point *int_blue_Z))
1989 #endif
1990
1991 #ifdef PNG_cHRM_SUPPORTED
1992 PNG_FP_EXPORT(135, void, png_set_cHRM, (png_const_structrp png_ptr,
1993 png_inforp info_ptr,
1994 double white_x, double white_y, double red_x, double red_y, double green_x,
1995 double green_y, double blue_x, double blue_y))
1996 PNG_FP_EXPORT(232, void, png_set_cHRM_XYZ, (png_const_structrp png_ptr,
1997 png_inforp info_ptr, double red_X, double red_Y, double red_Z,
1998 double green_X, double green_Y, double green_Z, double blue_X,
1999 double blue_Y, double blue_Z))
2000 PNG_FIXED_EXPORT(136, void, png_set_cHRM_fixed, (png_const_structrp png_ptr,
2001 png_inforp info_ptr, png_fixed_point int_white_x,
2002 png_fixed_point int_white_y, png_fixed_point int_red_x,
2003 png_fixed_point int_red_y, png_fixed_point int_green_x,
2004 png_fixed_point int_green_y, png_fixed_point int_blue_x,
2005 png_fixed_point int_blue_y))
2006 PNG_FIXED_EXPORT(233, void, png_set_cHRM_XYZ_fixed, (png_const_structrp png_ptr,
2007 png_inforp info_ptr, png_fixed_point int_red_X, png_fixed_point int_red_Y,
2008 png_fixed_point int_red_Z, png_fixed_point int_green_X,
2009 png_fixed_point int_green_Y, png_fixed_point int_green_Z,
2010 png_fixed_point int_blue_X, png_fixed_point int_blue_Y,
2011 png_fixed_point int_blue_Z))
2012 #endif
2013
2014 #ifdef PNG_gAMA_SUPPORTED
2015 PNG_FP_EXPORT(137, png_uint_32, png_get_gAMA, (png_const_structrp png_ptr,
2016 png_const_inforp info_ptr, double *file_gamma))
2017 PNG_FIXED_EXPORT(138, png_uint_32, png_get_gAMA_fixed,
2018 (png_const_structrp png_ptr, png_const_inforp info_ptr,
2019 png_fixed_point *int_file_gamma))
2020 #endif
2021
2022 #ifdef PNG_gAMA_SUPPORTED
2023 PNG_FP_EXPORT(139, void, png_set_gAMA, (png_const_structrp png_ptr,
2024 png_inforp info_ptr, double file_gamma))
2025 PNG_FIXED_EXPORT(140, void, png_set_gAMA_fixed, (png_const_structrp png_ptr,
2026 png_inforp info_ptr, png_fixed_point int_file_gamma))
2027 #endif
2028
2029 #ifdef PNG_hIST_SUPPORTED
2030 PNG_EXPORT(141, png_uint_32, png_get_hIST, (png_const_structrp png_ptr,
2031 png_inforp info_ptr, png_uint_16p *hist));
2032 #endif
2033
2034 #ifdef PNG_hIST_SUPPORTED
2035 PNG_EXPORT(142, void, png_set_hIST, (png_const_structrp png_ptr,
2036 png_inforp info_ptr, png_const_uint_16p hist));
2037 #endif
2038
2039 PNG_EXPORT(143, png_uint_32, png_get_IHDR, (png_const_structrp png_ptr,
2040 png_const_inforp info_ptr, png_uint_32 *width, png_uint_32 *height,
2041 int *bit_depth, int *color_type, int *interlace_method,
2042 int *compression_method, int *filter_method));
2043
2044 PNG_EXPORT(144, void, png_set_IHDR, (png_const_structrp png_ptr,
2045 png_inforp info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth,
2046 int color_type, int interlace_method, int compression_method,
2047 int filter_method));
2048
2049 #ifdef PNG_oFFs_SUPPORTED
2050 PNG_EXPORT(145, png_uint_32, png_get_oFFs, (png_const_structrp png_ptr,
2051 png_const_inforp info_ptr, png_int_32 *offset_x, png_int_32 *offset_y,
2052 int *unit_type));
2053 #endif
2054
2055 #ifdef PNG_oFFs_SUPPORTED
2056 PNG_EXPORT(146, void, png_set_oFFs, (png_const_structrp png_ptr,
2057 png_inforp info_ptr, png_int_32 offset_x, png_int_32 offset_y,
2058 int unit_type));
2059 #endif
2060
2061 #ifdef PNG_pCAL_SUPPORTED
2062 PNG_EXPORT(147, png_uint_32, png_get_pCAL, (png_const_structrp png_ptr,
2063 png_inforp info_ptr, png_charp *purpose, png_int_32 *X0,
2064 png_int_32 *X1, int *type, int *nparams, png_charp *units,
2065 png_charpp *params));
2066 #endif
2067
2068 #ifdef PNG_pCAL_SUPPORTED
2069 PNG_EXPORT(148, void, png_set_pCAL, (png_const_structrp png_ptr,
2070 png_inforp info_ptr, png_const_charp purpose, png_int_32 X0, png_int_32 X1,
2071 int type, int nparams, png_const_charp units, png_charpp params));
2072 #endif
2073
2074 #ifdef PNG_pHYs_SUPPORTED
2075 PNG_EXPORT(149, png_uint_32, png_get_pHYs, (png_const_structrp png_ptr,
2076 png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y,
2077 int *unit_type));
2078 #endif
2079
2080 #ifdef PNG_pHYs_SUPPORTED
2081 PNG_EXPORT(150, void, png_set_pHYs, (png_const_structrp png_ptr,
2082 png_inforp info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type));
2083 #endif
2084
2085 PNG_EXPORT(151, png_uint_32, png_get_PLTE, (png_const_structrp png_ptr,
2086 png_inforp info_ptr, png_colorp *palette, int *num_palette));
2087
2088 PNG_EXPORT(152, void, png_set_PLTE, (png_structrp png_ptr,
2089 png_inforp info_ptr, png_const_colorp palette, int num_palette));
2090
2091 #ifdef PNG_sBIT_SUPPORTED
2092 PNG_EXPORT(153, png_uint_32, png_get_sBIT, (png_const_structrp png_ptr,
2093 png_inforp info_ptr, png_color_8p *sig_bit));
2094 #endif
2095
2096 #ifdef PNG_sBIT_SUPPORTED
2097 PNG_EXPORT(154, void, png_set_sBIT, (png_const_structrp png_ptr,
2098 png_inforp info_ptr, png_const_color_8p sig_bit));
2099 #endif
2100
2101 #ifdef PNG_sRGB_SUPPORTED
2102 PNG_EXPORT(155, png_uint_32, png_get_sRGB, (png_const_structrp png_ptr,
2103 png_const_inforp info_ptr, int *file_srgb_intent));
2104 #endif
2105
2106 #ifdef PNG_sRGB_SUPPORTED
2107 PNG_EXPORT(156, void, png_set_sRGB, (png_const_structrp png_ptr,
2108 png_inforp info_ptr, int srgb_intent));
2109 PNG_EXPORT(157, void, png_set_sRGB_gAMA_and_cHRM, (png_const_structrp png_ptr,
2110 png_inforp info_ptr, int srgb_intent));
2111 #endif
2112
2113 #ifdef PNG_iCCP_SUPPORTED
2114 PNG_EXPORT(158, png_uint_32, png_get_iCCP, (png_const_structrp png_ptr,
2115 png_inforp info_ptr, png_charpp name, int *compression_type,
2116 png_bytepp profile, png_uint_32 *proflen));
2117 #endif
2118
2119 #ifdef PNG_iCCP_SUPPORTED
2120 PNG_EXPORT(159, void, png_set_iCCP, (png_const_structrp png_ptr,
2121 png_inforp info_ptr, png_const_charp name, int compression_type,
2122 png_const_bytep profile, png_uint_32 proflen));
2123 #endif
2124
2125 #ifdef PNG_sPLT_SUPPORTED
2126 PNG_EXPORT(160, int, png_get_sPLT, (png_const_structrp png_ptr,
2127 png_inforp info_ptr, png_sPLT_tpp entries));
2128 #endif
2129
2130 #ifdef PNG_sPLT_SUPPORTED
2131 PNG_EXPORT(161, void, png_set_sPLT, (png_const_structrp png_ptr,
2132 png_inforp info_ptr, png_const_sPLT_tp entries, int nentries));
2133 #endif
2134
2135 #ifdef PNG_TEXT_SUPPORTED
2136 /* png_get_text also returns the number of text chunks in *num_text */
2137 PNG_EXPORT(162, int, png_get_text, (png_const_structrp png_ptr,
2138 png_inforp info_ptr, png_textp *text_ptr, int *num_text));
2139 #endif
2140
2141 /* Note while png_set_text() will accept a structure whose text,
2142 * language, and translated keywords are NULL pointers, the structure
2143 * returned by png_get_text will always contain regular
2144 * zero-terminated C strings. They might be empty strings but
2145 * they will never be NULL pointers.
2146 */
2147
2148 #ifdef PNG_TEXT_SUPPORTED
2149 PNG_EXPORT(163, void, png_set_text, (png_const_structrp png_ptr,
2150 png_inforp info_ptr, png_const_textp text_ptr, int num_text));
2151 #endif
2152
2153 #ifdef PNG_tIME_SUPPORTED
2154 PNG_EXPORT(164, png_uint_32, png_get_tIME, (png_const_structrp png_ptr,
2155 png_inforp info_ptr, png_timep *mod_time));
2156 #endif
2157
2158 #ifdef PNG_tIME_SUPPORTED
2159 PNG_EXPORT(165, void, png_set_tIME, (png_const_structrp png_ptr,
2160 png_inforp info_ptr, png_const_timep mod_time));
2161 #endif
2162
2163 #ifdef PNG_tRNS_SUPPORTED
2164 PNG_EXPORT(166, png_uint_32, png_get_tRNS, (png_const_structrp png_ptr,
2165 png_inforp info_ptr, png_bytep *trans_alpha, int *num_trans,
2166 png_color_16p *trans_color));
2167 #endif
2168
2169 #ifdef PNG_tRNS_SUPPORTED
2170 PNG_EXPORT(167, void, png_set_tRNS, (png_structrp png_ptr,
2171 png_inforp info_ptr, png_const_bytep trans_alpha, int num_trans,
2172 png_const_color_16p trans_color));
2173 #endif
2174
2175 #ifdef PNG_sCAL_SUPPORTED
2176 PNG_FP_EXPORT(168, png_uint_32, png_get_sCAL, (png_const_structrp png_ptr,
2177 png_const_inforp info_ptr, int *unit, double *width, double *height))
2178 #if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || \
2179 defined(PNG_FLOATING_POINT_SUPPORTED)
2180 /* NOTE: this API is currently implemented using floating point arithmetic,
2181 * consequently it can only be used on systems with floating point support.
2182 * In any case the range of values supported by png_fixed_point is small and it
2183 * is highly recommended that png_get_sCAL_s be used instead.
2184 */
2185 PNG_FIXED_EXPORT(214, png_uint_32, png_get_sCAL_fixed,
2186 (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit,
2187 png_fixed_point *width, png_fixed_point *height))
2188 #endif
2189 PNG_EXPORT(169, png_uint_32, png_get_sCAL_s,
2190 (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit,
2191 png_charpp swidth, png_charpp sheight));
2192
2193 PNG_FP_EXPORT(170, void, png_set_sCAL, (png_const_structrp png_ptr,
2194 png_inforp info_ptr, int unit, double width, double height))
2195 PNG_FIXED_EXPORT(213, void, png_set_sCAL_fixed, (png_const_structrp png_ptr,
2196 png_inforp info_ptr, int unit, png_fixed_point width,
2197 png_fixed_point height))
2198 PNG_EXPORT(171, void, png_set_sCAL_s, (png_const_structrp png_ptr,
2199 png_inforp info_ptr, int unit,
2200 png_const_charp swidth, png_const_charp sheight));
2201 #endif /* sCAL */
2202
2203 #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
2204 /* Provide the default handling for all unknown chunks or, optionally, for
2205 * specific unknown chunks.
2206 *
2207 * NOTE: prior to 1.6.0 the handling specified for particular chunks on read was
2208 * ignored and the default was used, the per-chunk setting only had an effect on
2209 * write. If you wish to have chunk-specific handling on read in code that must
2210 * work on earlier versions you must use a user chunk callback to specify the
2211 * desired handling (keep or discard.)
2212 *
2213 * The 'keep' parameter is a PNG_HANDLE_CHUNK_ value as listed below. The
2214 * parameter is interpreted as follows:
2215 *
2216 * READ:
2217 * PNG_HANDLE_CHUNK_AS_DEFAULT:
2218 * Known chunks: do normal libpng processing, do not keep the chunk (but
2219 * see the comments below about PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
2220 * Unknown chunks: for a specific chunk use the global default, when used
2221 * as the default discard the chunk data.
2222 * PNG_HANDLE_CHUNK_NEVER:
2223 * Discard the chunk data.
2224 * PNG_HANDLE_CHUNK_IF_SAFE:
2225 * Keep the chunk data if the chunk is not critical else raise a chunk
2226 * error.
2227 * PNG_HANDLE_CHUNK_ALWAYS:
2228 * Keep the chunk data.
2229 *
2230 * If the chunk data is saved it can be retrieved using png_get_unknown_chunks,
2231 * below. Notice that specifying "AS_DEFAULT" as a global default is equivalent
2232 * to specifying "NEVER", however when "AS_DEFAULT" is used for specific chunks
2233 * it simply resets the behavior to the libpng default.
2234 *
2235 * INTERACTION WTIH USER CHUNK CALLBACKS:
2236 * The per-chunk handling is always used when there is a png_user_chunk_ptr
2237 * callback and the callback returns 0; the chunk is then always stored *unless*
2238 * it is critical and the per-chunk setting is other than ALWAYS. Notice that
2239 * the global default is *not* used in this case. (In effect the per-chunk
2240 * value is incremented to at least IF_SAFE.)
2241 *
2242 * IMPORTANT NOTE: this behavior will change in libpng 1.7 - the global and
2243 * per-chunk defaults will be honored. If you want to preserve the current
2244 * behavior when your callback returns 0 you must set PNG_HANDLE_CHUNK_IF_SAFE
2245 * as the default - if you don't do this libpng 1.6 will issue a warning.
2246 *
2247 * If you want unhandled unknown chunks to be discarded in libpng 1.6 and
2248 * earlier simply return '1' (handled).
2249 *
2250 * PNG_HANDLE_AS_UNKNOWN_SUPPORTED:
2251 * If this is *not* set known chunks will always be handled by libpng and
2252 * will never be stored in the unknown chunk list. Known chunks listed to
2253 * png_set_keep_unknown_chunks will have no effect. If it is set then known
2254 * chunks listed with a keep other than AS_DEFAULT will *never* be processed
2255 * by libpng, in addition critical chunks must either be processed by the
2256 * callback or saved.
2257 *
2258 * The IHDR and IEND chunks must not be listed. Because this turns off the
2259 * default handling for chunks that would otherwise be recognized the
2260 * behavior of libpng transformations may well become incorrect!
2261 *
2262 * WRITE:
2263 * When writing chunks the options only apply to the chunks specified by
2264 * png_set_unknown_chunks (below), libpng will *always* write known chunks
2265 * required by png_set_ calls and will always write the core critical chunks
2266 * (as required for PLTE).
2267 *
2268 * Each chunk in the png_set_unknown_chunks list is looked up in the
2269 * png_set_keep_unknown_chunks list to find the keep setting, this is then
2270 * interpreted as follows:
2271 *
2272 * PNG_HANDLE_CHUNK_AS_DEFAULT:
2273 * Write safe-to-copy chunks and write other chunks if the global
2274 * default is set to _ALWAYS, otherwise don't write this chunk.
2275 * PNG_HANDLE_CHUNK_NEVER:
2276 * Do not write the chunk.
2277 * PNG_HANDLE_CHUNK_IF_SAFE:
2278 * Write the chunk if it is safe-to-copy, otherwise do not write it.
2279 * PNG_HANDLE_CHUNK_ALWAYS:
2280 * Write the chunk.
2281 *
2282 * Note that the default behavior is effectively the opposite of the read case -
2283 * in read unknown chunks are not stored by default, in write they are written
2284 * by default. Also the behavior of PNG_HANDLE_CHUNK_IF_SAFE is very different
2285 * - on write the safe-to-copy bit is checked, on read the critical bit is
2286 * checked and on read if the chunk is critical an error will be raised.
2287 *
2288 * num_chunks:
2289 * ===========
2290 * If num_chunks is positive, then the "keep" parameter specifies the manner
2291 * for handling only those chunks appearing in the chunk_list array,
2292 * otherwise the chunk list array is ignored.
2293 *
2294 * If num_chunks is 0 the "keep" parameter specifies the default behavior for
2295 * unknown chunks, as described above.
2296 *
2297 * If num_chunks is negative, then the "keep" parameter specifies the manner
2298 * for handling all unknown chunks plus all chunks recognized by libpng
2299 * except for the IHDR, PLTE, tRNS, IDAT, and IEND chunks (which continue to
2300 * be processed by libpng.
2301 */
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
2305 /* The "keep" PNG_HANDLE_CHUNK_ parameter for the specified chunk is returned;
2306 * the result is therefore true (non-zero) if special handling is required,
2307 * false for the default handling.
2308 */
2309 PNG_EXPORT(173, int, png_handle_as_unknown, (png_const_structrp png_ptr,
2310 png_const_bytep chunk_name));
2311 #endif
2312
2313 #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
2314 PNG_EXPORT(174, void, png_set_unknown_chunks, (png_const_structrp png_ptr,
2315 png_inforp info_ptr, png_const_unknown_chunkp unknowns,
2316 int num_unknowns));
2317 /* NOTE: prior to 1.6.0 this routine set the 'location' field of the added
2318 * unknowns to the location currently stored in the png_struct. This is
2319 * invariably the wrong value on write. To fix this call the following API
2320 * for each chunk in the list with the correct location. If you know your
2321 * code won't be compiled on earlier versions you can rely on
2322 * png_set_unknown_chunks(write-ptr, png_get_unknown_chunks(read-ptr)) doing
2323 * the correct thing.
2324 */
2325
2326 PNG_EXPORT(175, void, png_set_unknown_chunk_location,
2327 (png_const_structrp png_ptr, png_inforp info_ptr, int chunk, int location));
2328
2329 PNG_EXPORT(176, int, png_get_unknown_chunks, (png_const_structrp png_ptr,
2330 png_inforp info_ptr, png_unknown_chunkpp entries));
2331 #endif
2332
2333 /* Png_free_data() will turn off the "valid" flag for anything it frees.
2334 * If you need to turn it off for a chunk that your application has freed,
2335 * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK);
2336 */
2337 PNG_EXPORT(177, void, png_set_invalid, (png_const_structrp png_ptr,
2338 png_inforp info_ptr, int mask));
2339
2340 #ifdef PNG_INFO_IMAGE_SUPPORTED
2341 /* The "params" pointer is currently not used and is for future expansion. */
2342 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
2343 PNG_EXPORT(178, void, png_read_png, (png_structrp png_ptr, png_inforp info_ptr,
2344 int transforms, png_voidp params));
2345 #endif
2346 #ifdef PNG_WRITE_SUPPORTED
2347 PNG_EXPORT(179, void, png_write_png, (png_structrp png_ptr, png_inforp info_ptr,
2348 int transforms, png_voidp params));
2349 #endif
2350 #endif
2351
2352 PNG_EXPORT(180, png_const_charp, png_get_copyright,
2353 (png_const_structrp png_ptr));
2354 PNG_EXPORT(181, png_const_charp, png_get_header_ver,
2355 (png_const_structrp png_ptr));
2356 PNG_EXPORT(182, png_const_charp, png_get_header_version,
2357 (png_const_structrp png_ptr));
2358 PNG_EXPORT(183, png_const_charp, png_get_libpng_ver,
2359 (png_const_structrp png_ptr));
2360
2361 #ifdef PNG_MNG_FEATURES_SUPPORTED
2362 PNG_EXPORT(184, png_uint_32, png_permit_mng_features, (png_structrp png_ptr,
2363 png_uint_32 mng_features_permitted));
2364 #endif
2365
2366 /* For use in png_set_keep_unknown, added to version 1.2.6 */
2367 #define PNG_HANDLE_CHUNK_AS_DEFAULT 0
2368 #define PNG_HANDLE_CHUNK_NEVER 1
2369 #define PNG_HANDLE_CHUNK_IF_SAFE 2
2370 #define PNG_HANDLE_CHUNK_ALWAYS 3
2371 #define PNG_HANDLE_CHUNK_LAST 4
2372
2373 /* Strip the prepended error numbers ("#nnn ") from error and warning
2374 * messages before passing them to the error or warning handler.
2375 */
2376 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
2377 PNG_EXPORT(185, void, png_set_strip_error_numbers, (png_structrp png_ptr,
2378 png_uint_32 strip_mode));
2379 #endif
2380
2381 /* Added in libpng-1.2.6 */
2382 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
2383 PNG_EXPORT(186, void, png_set_user_limits, (png_structrp png_ptr,
2384 png_uint_32 user_width_max, png_uint_32 user_height_max));
2385 PNG_EXPORT(187, png_uint_32, png_get_user_width_max,
2386 (png_const_structrp png_ptr));
2387 PNG_EXPORT(188, png_uint_32, png_get_user_height_max,
2388 (png_const_structrp png_ptr));
2389 /* Added in libpng-1.4.0 */
2390 PNG_EXPORT(189, void, png_set_chunk_cache_max, (png_structrp png_ptr,
2391 png_uint_32 user_chunk_cache_max));
2392 PNG_EXPORT(190, png_uint_32, png_get_chunk_cache_max,
2393 (png_const_structrp png_ptr));
2394 /* Added in libpng-1.4.1 */
2395 PNG_EXPORT(191, void, png_set_chunk_malloc_max, (png_structrp png_ptr,
2396 png_alloc_size_t user_chunk_cache_max));
2397 PNG_EXPORT(192, png_alloc_size_t, png_get_chunk_malloc_max,
2398 (png_const_structrp png_ptr));
2399 #endif
2400
2401 #if defined(PNG_INCH_CONVERSIONS_SUPPORTED)
2402 PNG_EXPORT(193, png_uint_32, png_get_pixels_per_inch,
2403 (png_const_structrp png_ptr, png_const_inforp info_ptr));
2404
2405 PNG_EXPORT(194, png_uint_32, png_get_x_pixels_per_inch,
2406 (png_const_structrp png_ptr, png_const_inforp info_ptr));
2407
2408 PNG_EXPORT(195, png_uint_32, png_get_y_pixels_per_inch,
2409 (png_const_structrp png_ptr, png_const_inforp info_ptr));
2410
2411 PNG_FP_EXPORT(196, float, png_get_x_offset_inches,
2412 (png_const_structrp png_ptr, png_const_inforp info_ptr))
2413 #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */
2414 PNG_FIXED_EXPORT(211, png_fixed_point, png_get_x_offset_inches_fixed,
2415 (png_const_structrp png_ptr, png_const_inforp info_ptr))
2416 #endif
2417
2418 PNG_FP_EXPORT(197, float, png_get_y_offset_inches, (png_const_structrp png_ptr,
2419 png_const_inforp info_ptr))
2420 #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */
2421 PNG_FIXED_EXPORT(212, png_fixed_point, png_get_y_offset_inches_fixed,
2422 (png_const_structrp png_ptr, png_const_inforp info_ptr))
2423 #endif
2424
2425 # ifdef PNG_pHYs_SUPPORTED
2426 PNG_EXPORT(198, png_uint_32, png_get_pHYs_dpi, (png_const_structrp png_ptr,
2427 png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y,
2428 int *unit_type));
2429 # endif /* pHYs */
2430 #endif /* INCH_CONVERSIONS */
2431
2432 /* Added in libpng-1.4.0 */
2433 #ifdef PNG_IO_STATE_SUPPORTED
2434 PNG_EXPORT(199, png_uint_32, png_get_io_state, (png_const_structrp png_ptr));
2435
2436 /* Removed from libpng 1.6; use png_get_io_chunk_type. */
2437 PNG_REMOVED(200, png_const_bytep, png_get_io_chunk_name, (png_structrp png_ptr),
2438 PNG_DEPRECATED)
2439
2440 PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type,
2441 (png_const_structrp png_ptr));
2442
2443 /* The flags returned by png_get_io_state() are the following: */
2444 # define PNG_IO_NONE 0x0000 /* no I/O at this moment */
2445 # define PNG_IO_READING 0x0001 /* currently reading */
2446 # define PNG_IO_WRITING 0x0002 /* currently writing */
2447 # define PNG_IO_SIGNATURE 0x0010 /* currently at the file signature */
2448 # define PNG_IO_CHUNK_HDR 0x0020 /* currently at the chunk header */
2449 # define PNG_IO_CHUNK_DATA 0x0040 /* currently at the chunk data */
2450 # define PNG_IO_CHUNK_CRC 0x0080 /* currently at the chunk crc */
2451 # define PNG_IO_MASK_OP 0x000f /* current operation: reading/writing */
2452 # define PNG_IO_MASK_LOC 0x00f0 /* current location: sig/hdr/data/crc */
2453 #endif /* IO_STATE */
2454
2455 /* Interlace support. The following macros are always defined so that if
2456 * libpng interlace handling is turned off the macros may be used to handle
2457 * interlaced images within the application.
2458 */
2459 #define PNG_INTERLACE_ADAM7_PASSES 7
2460
2461 /* Two macros to return the first row and first column of the original,
2462 * full, image which appears in a given pass. 'pass' is in the range 0
2463 * to 6 and the result is in the range 0 to 7.
2464 */
2465 #define PNG_PASS_START_ROW(pass) (((1&~(pass))<<(3-((pass)>>1)))&7)
2466 #define PNG_PASS_START_COL(pass) (((1& (pass))<<(3-(((pass)+1)>>1)))&7)
2467
2468 /* A macro to return the offset between pixels in the output row for a pair of
2469 * pixels in the input - effectively the inverse of the 'COL_SHIFT' macro that
2470 * follows. Note that ROW_OFFSET is the offset from one row to the next whereas
2471 * COL_OFFSET is from one column to the next, within a row.
2472 */
2473 #define PNG_PASS_ROW_OFFSET(pass) ((pass)>2?(8>>(((pass)-1)>>1)):8)
2474 #define PNG_PASS_COL_OFFSET(pass) (1<<((7-(pass))>>1))
2475
2476 /* Two macros to help evaluate the number of rows or columns in each
2477 * pass. This is expressed as a shift - effectively log2 of the number or
2478 * rows or columns in each 8x8 tile of the original image.
2479 */
2480 #define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3)
2481 #define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3)
2482
2483 /* Hence two macros to determine the number of rows or columns in a given
2484 * pass of an image given its height or width. In fact these macros may
2485 * return non-zero even though the sub-image is empty, because the other
2486 * dimension may be empty for a small image.
2487 */
2488 #define PNG_PASS_ROWS(height, pass) (((height)+(((1<<PNG_PASS_ROW_SHIFT(pass))\
2489 -1)-PNG_PASS_START_ROW(pass)))>>PNG_PASS_ROW_SHIFT(pass))
2490 #define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\
2491 -1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass))
2492
2493 /* For the reader row callbacks (both progressive and sequential) it is
2494 * necessary to find the row in the output image given a row in an interlaced
2495 * image, so two more macros:
2496 */
2497 #define PNG_ROW_FROM_PASS_ROW(y_in, pass) \
2498 (((y_in)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass))
2499 #define PNG_COL_FROM_PASS_COL(x_in, pass) \
2500 (((x_in)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass))
2501
2502 /* Two macros which return a boolean (0 or 1) saying whether the given row
2503 * or column is in a particular pass. These use a common utility macro that
2504 * returns a mask for a given pass - the offset 'off' selects the row or
2505 * column version. The mask has the appropriate bit set for each column in
2506 * the tile.
2507 */
2508 #define PNG_PASS_MASK(pass,off) ( \
2509 ((0x110145AF>>(((7-(off))-(pass))<<2)) & 0xF) | \
2510 ((0x01145AF0>>(((7-(off))-(pass))<<2)) & 0xF0))
2511
2512 #define PNG_ROW_IN_INTERLACE_PASS(y, pass) \
2513 ((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1)
2514 #define PNG_COL_IN_INTERLACE_PASS(x, pass) \
2515 ((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1)
2516
2517 #ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
2518 /* With these routines we avoid an integer divide, which will be slower on
2519 * most machines. However, it does take more operations than the corresponding
2520 * divide method, so it may be slower on a few RISC systems. There are two
2521 * shifts (by 8 or 16 bits) and an addition, versus a single integer divide.
2522 *
2523 * Note that the rounding factors are NOT supposed to be the same! 128 and
2524 * 32768 are correct for the NODIV code; 127 and 32767 are correct for the
2525 * standard method.
2526 *
2527 * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
2528 */
2529
2530 /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */
2531
2532 # define png_composite(composite, fg, alpha, bg) \
2533 { png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \
2534 * (png_uint_16)(alpha) \
2535 + (png_uint_16)(bg)*(png_uint_16)(255 \
2536 - (png_uint_16)(alpha)) + 128); \
2537 (composite) = (png_byte)(((temp + (temp >> 8)) >> 8) & 0xff); }
2538
2539 # define png_composite_16(composite, fg, alpha, bg) \
2540 { png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) \
2541 * (png_uint_32)(alpha) \
2542 + (png_uint_32)(bg)*(65535 \
2543 - (png_uint_32)(alpha)) + 32768); \
2544 (composite) = (png_uint_16)(0xffff & ((temp + (temp >> 16)) >> 16)); }
2545
2546 #else /* Standard method using integer division */
2547
2548 # define png_composite(composite, fg, alpha, bg) \
2549 (composite) = \
2550 (png_byte)(0xff & (((png_uint_16)(fg) * (png_uint_16)(alpha) + \
2551 (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \
2552 127) / 255))
2553
2554 # define png_composite_16(composite, fg, alpha, bg) \
2555 (composite) = \
2556 (png_uint_16)(0xffff & (((png_uint_32)(fg) * (png_uint_32)(alpha) + \
2557 (png_uint_32)(bg)*(png_uint_32)(65535 - (png_uint_32)(alpha)) + \
2558 32767) / 65535))
2559 #endif /* READ_COMPOSITE_NODIV */
2560
2561 #ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED
2562 PNG_EXPORT(201, png_uint_32, png_get_uint_32, (png_const_bytep buf));
2563 PNG_EXPORT(202, png_uint_16, png_get_uint_16, (png_const_bytep buf));
2564 PNG_EXPORT(203, png_int_32, png_get_int_32, (png_const_bytep buf));
2565 #endif
2566
2567 PNG_EXPORT(204, png_uint_32, png_get_uint_31, (png_const_structrp png_ptr,
2568 png_const_bytep buf));
2569 /* No png_get_int_16 -- may be added if there's a real need for it. */
2570
2571 /* Place a 32-bit number into a buffer in PNG byte order (big-endian). */
2572 #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
2573 PNG_EXPORT(205, void, png_save_uint_32, (png_bytep buf, png_uint_32 i));
2574 #endif
2575 #ifdef PNG_SAVE_INT_32_SUPPORTED
2576 PNG_EXPORT(206, void, png_save_int_32, (png_bytep buf, png_int_32 i));
2577 #endif
2578
2579 /* Place a 16-bit number into a buffer in PNG byte order.
2580 * The parameter is declared unsigned int, not png_uint_16,
2581 * just to avoid potential problems on pre-ANSI C compilers.
2582 */
2583 #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
2584 PNG_EXPORT(207, void, png_save_uint_16, (png_bytep buf, unsigned int i));
2585 /* No png_save_int_16 -- may be added if there's a real need for it. */
2586 #endif
2587
2588 #ifdef PNG_USE_READ_MACROS
2589 /* Inline macros to do direct reads of bytes from the input buffer.
2590 * The png_get_int_32() routine assumes we are using two's complement
2591 * format for negative values, which is almost certainly true.
2592 */
2593 # define PNG_get_uint_32(buf) \
2594 (((png_uint_32)(*(buf)) << 24) + \
2595 ((png_uint_32)(*((buf) + 1)) << 16) + \
2596 ((png_uint_32)(*((buf) + 2)) << 8) + \
2597 ((png_uint_32)(*((buf) + 3))))
2598
2599 /* From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the
2600 * function) incorrectly returned a value of type png_uint_32.
2601 */
2602 # define PNG_get_uint_16(buf) \
2603 ((png_uint_16) \
2604 (((unsigned int)(*(buf)) << 8) + \
2605 ((unsigned int)(*((buf) + 1)))))
2606
2607 # define PNG_get_int_32(buf) \
2608 ((png_int_32)((*(buf) & 0x80) \
2609 ? -((png_int_32)(((png_get_uint_32(buf)^0xffffffffU)+1U)&0x7fffffffU)) \
2610 : (png_int_32)png_get_uint_32(buf)))
2611
2612 /* If PNG_PREFIX is defined the same thing as below happens in pnglibconf.h,
2613 * but defining a macro name prefixed with PNG_PREFIX.
2614 */
2615 # ifndef PNG_PREFIX
2616 # define png_get_uint_32(buf) PNG_get_uint_32(buf)
2617 # define png_get_uint_16(buf) PNG_get_uint_16(buf)
2618 # define png_get_int_32(buf) PNG_get_int_32(buf)
2619 # endif
2620 #else
2621 # ifdef PNG_PREFIX
2622 /* No macros; revert to the (redefined) function */
2623 # define PNG_get_uint_32 (png_get_uint_32)
2624 # define PNG_get_uint_16 (png_get_uint_16)
2625 # define PNG_get_int_32 (png_get_int_32)
2626 # endif
2627 #endif
2628
2629 #ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
2630 PNG_EXPORT(242, void, png_set_check_for_invalid_index,
2631 (png_structrp png_ptr, int allowed));
2632 # ifdef PNG_GET_PALETTE_MAX_SUPPORTED
2633 PNG_EXPORT(243, int, png_get_palette_max, (png_const_structp png_ptr,
2634 png_const_infop info_ptr));
2635 # endif
2636 #endif /* CHECK_FOR_INVALID_INDEX */
2637
2638 /*******************************************************************************
2639 * Section 5: SIMPLIFIED API
2640 *******************************************************************************
2641 *
2642 * Please read the documentation in libpng-manual.txt (TODO: write said
2643 * documentation) if you don't understand what follows.
2644 *
2645 * The simplified API hides the details of both libpng and the PNG file format
2646 * itself. It allows PNG files to be read into a very limited number of
2647 * in-memory bitmap formats or to be written from the same formats. If these
2648 * formats do not accomodate your needs then you can, and should, use the more
2649 * sophisticated APIs above - these support a wide variety of in-memory formats
2650 * and a wide variety of sophisticated transformations to those formats as well
2651 * as a wide variety of APIs to manipulate ancillary information.
2652 *
2653 * To read a PNG file using the simplified API:
2654 *
2655 * 1) Declare a 'png_image' structure (see below) on the stack, set the
2656 * version field to PNG_IMAGE_VERSION and the 'opaque' pointer to NULL
2657 * (this is REQUIRED, your program may crash if you don't do it.)
2658 * 2) Call the appropriate png_image_begin_read... function.
2659 * 3) Set the png_image 'format' member to the required sample format.
2660 * 4) Allocate a buffer for the image and, if required, the color-map.
2661 * 5) Call png_image_finish_read to read the image and, if required, the
2662 * color-map into your buffers.
2663 *
2664 * There are no restrictions on the format of the PNG input itself; all valid
2665 * color types, bit depths, and interlace methods are acceptable, and the
2666 * input image is transformed as necessary to the requested in-memory format
2667 * during the png_image_finish_read() step. The only caveat is that if you
2668 * request a color-mapped image from a PNG that is full-color or makes
2669 * complex use of an alpha channel the transformation is extremely lossy and the
2670 * result may look terrible.
2671 *
2672 * To write a PNG file using the simplified API:
2673 *
2674 * 1) Declare a 'png_image' structure on the stack and memset() it to all zero.
2675 * 2) Initialize the members of the structure that describe the image, setting
2676 * the 'format' member to the format of the image samples.
2677 * 3) Call the appropriate png_image_write... function with a pointer to the
2678 * image and, if necessary, the color-map to write the PNG data.
2679 *
2680 * png_image is a structure that describes the in-memory format of an image
2681 * when it is being read or defines the in-memory format of an image that you
2682 * need to write:
2683 */
2684 #if defined(PNG_SIMPLIFIED_READ_SUPPORTED) || \
2685 defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
2686
2687 #define PNG_IMAGE_VERSION 1
2688
2689 typedef struct png_control *png_controlp;
2690 typedef struct
2691 {
2692 png_controlp opaque; /* Initialize to NULL, free with png_image_free */
2693 png_uint_32 version; /* Set to PNG_IMAGE_VERSION */
2694 png_uint_32 width; /* Image width in pixels (columns) */
2695 png_uint_32 height; /* Image height in pixels (rows) */
2696 png_uint_32 format; /* Image format as defined below */
2697 png_uint_32 flags; /* A bit mask containing informational flags */
2698 png_uint_32 colormap_entries;
2699 /* Number of entries in the color-map */
2700
2701 /* In the event of an error or warning the following field will be set to a
2702 * non-zero value and the 'message' field will contain a '\0' terminated
2703 * string with the libpng error or warning message. If both warnings and
2704 * an error were encountered, only the error is recorded. If there
2705 * are multiple warnings, only the first one is recorded.
2706 *
2707 * The upper 30 bits of this value are reserved, the low two bits contain
2708 * a value as follows:
2709 */
2710 # define PNG_IMAGE_WARNING 1
2711 # define PNG_IMAGE_ERROR 2
2712 /*
2713 * The result is a two-bit code such that a value more than 1 indicates
2714 * a failure in the API just called:
2715 *
2716 * 0 - no warning or error
2717 * 1 - warning
2718 * 2 - error
2719 * 3 - error preceded by warning
2720 */
2721 # define PNG_IMAGE_FAILED(png_cntrl) ((((png_cntrl).warning_or_error)&0x03)>1)
2722
2723 png_uint_32 warning_or_error;
2724
2725 char message[64];
2726 } png_image, *png_imagep;
2727
2728 /* The samples of the image have one to four channels whose components have
2729 * original values in the range 0 to 1.0:
2730 *
2731 * 1: A single gray or luminance channel (G).
2732 * 2: A gray/luminance channel and an alpha channel (GA).
2733 * 3: Three red, green, blue color channels (RGB).
2734 * 4: Three color channels and an alpha channel (RGBA).
2735 *
2736 * The components are encoded in one of two ways:
2737 *
2738 * a) As a small integer, value 0..255, contained in a single byte. For the
2739 * alpha channel the original value is simply value/255. For the color or
2740 * luminance channels the value is encoded according to the sRGB specification
2741 * and matches the 8-bit format expected by typical display devices.
2742 *
2743 * The color/gray channels are not scaled (pre-multiplied) by the alpha
2744 * channel and are suitable for passing to color management software.
2745 *
2746 * b) As a value in the range 0..65535, contained in a 2-byte integer. All
2747 * channels can be converted to the original value by dividing by 65535; all
2748 * channels are linear. Color channels use the RGB encoding (RGB end-points) of
2749 * the sRGB specification. This encoding is identified by the
2750 * PNG_FORMAT_FLAG_LINEAR flag below.
2751 *
2752 * When the simplified API needs to convert between sRGB and linear colorspaces,
2753 * the actual sRGB transfer curve defined in the sRGB specification (see the
2754 * article at http://en.wikipedia.org/wiki/SRGB) is used, not the gamma=1/2.2
2755 * approximation used elsewhere in libpng.
2756 *
2757 * When an alpha channel is present it is expected to denote pixel coverage
2758 * of the color or luminance channels and is returned as an associated alpha
2759 * channel: the color/gray channels are scaled (pre-multiplied) by the alpha
2760 * value.
2761 *
2762 * The samples are either contained directly in the image data, between 1 and 8
2763 * bytes per pixel according to the encoding, or are held in a color-map indexed
2764 * by bytes in the image data. In the case of a color-map the color-map entries
2765 * are individual samples, encoded as above, and the image data has one byte per
2766 * pixel to select the relevant sample from the color-map.
2767 */
2768
2769 /* PNG_FORMAT_*
2770 *
2771 * #defines to be used in png_image::format. Each #define identifies a
2772 * particular layout of sample data and, if present, alpha values. There are
2773 * separate defines for each of the two component encodings.
2774 *
2775 * A format is built up using single bit flag values. All combinations are
2776 * valid. Formats can be built up from the flag values or you can use one of
2777 * the predefined values below. When testing formats always use the FORMAT_FLAG
2778 * macros to test for individual features - future versions of the library may
2779 * add new flags.
2780 *
2781 * When reading or writing color-mapped images the format should be set to the
2782 * format of the entries in the color-map then png_image_{read,write}_colormap
2783 * called to read or write the color-map and set the format correctly for the
2784 * image data. Do not set the PNG_FORMAT_FLAG_COLORMAP bit directly!
2785 *
2786 * NOTE: libpng can be built with particular features disabled. If you see
2787 * compiler errors because the definition of one of the following flags has been
2788 * compiled out it is because libpng does not have the required support. It is
2789 * possible, however, for the libpng configuration to enable the format on just
2790 * read or just write; in that case you may see an error at run time. You can
2791 * guard against this by checking for the definition of the appropriate
2792 * "_SUPPORTED" macro, one of:
2793 *
2794 * PNG_SIMPLIFIED_{READ,WRITE}_{BGR,AFIRST}_SUPPORTED
2795 */
2796 #define PNG_FORMAT_FLAG_ALPHA 0x01U /* format with an alpha channel */
2797 #define PNG_FORMAT_FLAG_COLOR 0x02U /* color format: otherwise grayscale */
2798 #define PNG_FORMAT_FLAG_LINEAR 0x04U /* 2-byte channels else 1-byte */
2799 #define PNG_FORMAT_FLAG_COLORMAP 0x08U /* image data is color-mapped */
2800
2801 #ifdef PNG_FORMAT_BGR_SUPPORTED
2802 # define PNG_FORMAT_FLAG_BGR 0x10U /* BGR colors, else order is RGB */
2803 #endif
2804
2805 #ifdef PNG_FORMAT_AFIRST_SUPPORTED
2806 # define PNG_FORMAT_FLAG_AFIRST 0x20U /* alpha channel comes first */
2807 #endif
2808
2809 /* Commonly used formats have predefined macros.
2810 *
2811 * First the single byte (sRGB) formats:
2812 */
2813 #define PNG_FORMAT_GRAY 0
2814 #define PNG_FORMAT_GA PNG_FORMAT_FLAG_ALPHA
2815 #define PNG_FORMAT_AG (PNG_FORMAT_GA|PNG_FORMAT_FLAG_AFIRST)
2816 #define PNG_FORMAT_RGB PNG_FORMAT_FLAG_COLOR
2817 #define PNG_FORMAT_BGR (PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_BGR)
2818 #define PNG_FORMAT_RGBA (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_ALPHA)
2819 #define PNG_FORMAT_ARGB (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_AFIRST)
2820 #define PNG_FORMAT_BGRA (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_ALPHA)
2821 #define PNG_FORMAT_ABGR (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_AFIRST)
2822
2823 /* Then the linear 2-byte formats. When naming these "Y" is used to
2824 * indicate a luminance (gray) channel.
2825 */
2826 #define PNG_FORMAT_LINEAR_Y PNG_FORMAT_FLAG_LINEAR
2827 #define PNG_FORMAT_LINEAR_Y_ALPHA (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_ALPHA)
2828 #define PNG_FORMAT_LINEAR_RGB (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR)
2829 #define PNG_FORMAT_LINEAR_RGB_ALPHA \
2830 (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA)
2831
2832 /* With color-mapped formats the image data is one byte for each pixel, the byte
2833 * is an index into the color-map which is formatted as above. To obtain a
2834 * color-mapped format it is sufficient just to add the PNG_FOMAT_FLAG_COLORMAP
2835 * to one of the above definitions, or you can use one of the definitions below.
2836 */
2837 #define PNG_FORMAT_RGB_COLORMAP (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_COLORMAP)
2838 #define PNG_FORMAT_BGR_COLORMAP (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_COLORMAP)
2839 #define PNG_FORMAT_RGBA_COLORMAP (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_COLORMAP)
2840 #define PNG_FORMAT_ARGB_COLORMAP (PNG_FORMAT_ARGB|PNG_FORMAT_FLAG_COLORMAP)
2841 #define PNG_FORMAT_BGRA_COLORMAP (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_COLORMAP)
2842 #define PNG_FORMAT_ABGR_COLORMAP (PNG_FORMAT_ABGR|PNG_FORMAT_FLAG_COLORMAP)
2843
2844 /* PNG_IMAGE macros
2845 *
2846 * These are convenience macros to derive information from a png_image
2847 * structure. The PNG_IMAGE_SAMPLE_ macros return values appropriate to the
2848 * actual image sample values - either the entries in the color-map or the
2849 * pixels in the image. The PNG_IMAGE_PIXEL_ macros return corresponding values
2850 * for the pixels and will always return 1 for color-mapped formats. The
2851 * remaining macros return information about the rows in the image and the
2852 * complete image.
2853 *
2854 * NOTE: All the macros that take a png_image::format parameter are compile time
2855 * constants if the format parameter is, itself, a constant. Therefore these
2856 * macros can be used in array declarations and case labels where required.
2857 * Similarly the macros are also pre-processor constants (sizeof is not used) so
2858 * they can be used in #if tests.
2859 *
2860 * First the information about the samples.
2861 */
2862 #define PNG_IMAGE_SAMPLE_CHANNELS(fmt)\
2863 (((fmt)&(PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA))+1)
2864 /* Return the total number of channels in a given format: 1..4 */
2865
2866 #define PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)\
2867 ((((fmt) & PNG_FORMAT_FLAG_LINEAR) >> 2)+1)
2868 /* Return the size in bytes of a single component of a pixel or color-map
2869 * entry (as appropriate) in the image: 1 or 2.
2870 */
2871
2872 #define PNG_IMAGE_SAMPLE_SIZE(fmt)\
2873 (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt))
2874 /* This is the size of the sample data for one sample. If the image is
2875 * color-mapped it is the size of one color-map entry (and image pixels are
2876 * one byte in size), otherwise it is the size of one image pixel.
2877 */
2878
2879 #define PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(fmt)\
2880 (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * 256)
2881 /* The maximum size of the color-map required by the format expressed in a
2882 * count of components. This can be used to compile-time allocate a
2883 * color-map:
2884 *
2885 * png_uint_16 colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(linear_fmt)];
2886 *
2887 * png_byte colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(sRGB_fmt)];
2888 *
2889 * Alternatively use the PNG_IMAGE_COLORMAP_SIZE macro below to use the
2890 * information from one of the png_image_begin_read_ APIs and dynamically
2891 * allocate the required memory.
2892 */
2893
2894 /* Corresponding information about the pixels */
2895 #define PNG_IMAGE_PIXEL_(test,fmt)\
2896 (((fmt)&PNG_FORMAT_FLAG_COLORMAP)?1:test(fmt))
2897
2898 #define PNG_IMAGE_PIXEL_CHANNELS(fmt)\
2899 PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_CHANNELS,fmt)
2900 /* The number of separate channels (components) in a pixel; 1 for a
2901 * color-mapped image.
2902 */
2903
2904 #define PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt)\
2905 PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_COMPONENT_SIZE,fmt)
2906 /* The size, in bytes, of each component in a pixel; 1 for a color-mapped
2907 * image.
2908 */
2909
2910 #define PNG_IMAGE_PIXEL_SIZE(fmt) PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_SIZE,fmt)
2911 /* The size, in bytes, of a complete pixel; 1 for a color-mapped image. */
2912
2913 /* Information about the whole row, or whole image */
2914 #define PNG_IMAGE_ROW_STRIDE(image)\
2915 (PNG_IMAGE_PIXEL_CHANNELS((image).format) * (image).width)
2916 /* Return the total number of components in a single row of the image; this
2917 * is the minimum 'row stride', the minimum count of components between each
2918 * row. For a color-mapped image this is the minimum number of bytes in a
2919 * row.
2920 */
2921
2922 #define PNG_IMAGE_BUFFER_SIZE(image, row_stride)\
2923 (PNG_IMAGE_PIXEL_COMPONENT_SIZE((image).format)*(image).height*(row_stride))
2924 /* Return the size, in bytes, of an image buffer given a png_image and a row
2925 * stride - the number of components to leave space for in each row.
2926 */
2927
2928 #define PNG_IMAGE_SIZE(image)\
2929 PNG_IMAGE_BUFFER_SIZE(image, PNG_IMAGE_ROW_STRIDE(image))
2930 /* Return the size, in bytes, of the image in memory given just a png_image;
2931 * the row stride is the minimum stride required for the image.
2932 */
2933
2934 #define PNG_IMAGE_COLORMAP_SIZE(image)\
2935 (PNG_IMAGE_SAMPLE_SIZE((image).format) * (image).colormap_entries)
2936 /* Return the size, in bytes, of the color-map of this image. If the image
2937 * format is not a color-map format this will return a size sufficient for
2938 * 256 entries in the given format; check PNG_FORMAT_FLAG_COLORMAP if
2939 * you don't want to allocate a color-map in this case.
2940 */
2941
2942 /* PNG_IMAGE_FLAG_*
2943 *
2944 * Flags containing additional information about the image are held in the
2945 * 'flags' field of png_image.
2946 */
2947 #define PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB 0x01
2948 /* This indicates the the RGB values of the in-memory bitmap do not
2949 * correspond to the red, green and blue end-points defined by sRGB.
2950 */
2951
2952 #define PNG_IMAGE_FLAG_FAST 0x02
2953 /* On write emphasise speed over compression; the resultant PNG file will be
2954 * larger but will be produced significantly faster, particular for large
2955 * images. Do not use this option for images which will be distributed, only
2956 * used it when producing intermediate files that will be read back in
2957 * repeatedly. For a typical 24-bit image the option will double the read
2958 * speed at the cost of increasing the image size by 25%, however for many
2959 * more compressible images the PNG file can be 10 times larger with only a
2960 * slight speed gain.
2961 */
2962
2963 #define PNG_IMAGE_FLAG_16BIT_sRGB 0x04
2964 /* On read if the image is a 16-bit per component image and there is no gAMA
2965 * or sRGB chunk assume that the components are sRGB encoded. Notice that
2966 * images output by the simplified API always have gamma information; setting
2967 * this flag only affects the interpretation of 16-bit images from an
2968 * external source. It is recommended that the application expose this flag
2969 * to the user; the user can normally easily recognize the difference between
2970 * linear and sRGB encoding. This flag has no effect on write - the data
2971 * passed to the write APIs must have the correct encoding (as defined
2972 * above.)
2973 *
2974 * If the flag is not set (the default) input 16-bit per component data is
2975 * assumed to be linear.
2976 *
2977 * NOTE: the flag can only be set after the png_image_begin_read_ call,
2978 * because that call initializes the 'flags' field.
2979 */
2980
2981 #ifdef PNG_SIMPLIFIED_READ_SUPPORTED
2982 /* READ APIs
2983 * ---------
2984 *
2985 * The png_image passed to the read APIs must have been initialized by setting
2986 * the png_controlp field 'opaque' to NULL (or, safer, memset the whole thing.)
2987 */
2988 #ifdef PNG_STDIO_SUPPORTED
2989 PNG_EXPORT(234, int, png_image_begin_read_from_file, (png_imagep image,
2990 const char *file_name));
2991 /* The named file is opened for read and the image header is filled in
2992 * from the PNG header in the file.
2993 */
2994
2995 PNG_EXPORT(235, int, png_image_begin_read_from_stdio, (png_imagep image,
2996 FILE* file));
2997 /* The PNG header is read from the stdio FILE object. */
2998 #endif /* STDIO */
2999
3000 PNG_EXPORT(236, int, png_image_begin_read_from_memory, (png_imagep image,
3001 png_const_voidp memory, png_size_t size));
3002 /* The PNG header is read from the given memory buffer. */
3003
3004 PNG_EXPORT(237, int, png_image_finish_read, (png_imagep image,
3005 png_const_colorp background, void *buffer, png_int_32 row_stride,
3006 void *colormap));
3007 /* Finish reading the image into the supplied buffer and clean up the
3008 * png_image structure.
3009 *
3010 * row_stride is the step, in byte or 2-byte units as appropriate,
3011 * between adjacent rows. A positive stride indicates that the top-most row
3012 * is first in the buffer - the normal top-down arrangement. A negative
3013 * stride indicates that the bottom-most row is first in the buffer.
3014 *
3015 * background need only be supplied if an alpha channel must be removed from
3016 * a png_byte format and the removal is to be done by compositing on a solid
3017 * color; otherwise it may be NULL and any composition will be done directly
3018 * onto the buffer. The value is an sRGB color to use for the background,
3019 * for grayscale output the green channel is used.
3020 *
3021 * background must be supplied when an alpha channel must be removed from a
3022 * single byte color-mapped output format, in other words if:
3023 *
3024 * 1) The original format from png_image_begin_read_from_* had
3025 * PNG_FORMAT_FLAG_ALPHA set.
3026 * 2) The format set by the application does not.
3027 * 3) The format set by the application has PNG_FORMAT_FLAG_COLORMAP set and
3028 * PNG_FORMAT_FLAG_LINEAR *not* set.
3029 *
3030 * For linear output removing the alpha channel is always done by compositing
3031 * on black and background is ignored.
3032 *
3033 * colormap must be supplied when PNG_FORMAT_FLAG_COLORMAP is set. It must
3034 * be at least the size (in bytes) returned by PNG_IMAGE_COLORMAP_SIZE.
3035 * image->colormap_entries will be updated to the actual number of entries
3036 * written to the colormap; this may be less than the original value.
3037 */
3038
3039 PNG_EXPORT(238, void, png_image_free, (png_imagep image));
3040 /* Free any data allocated by libpng in image->opaque, setting the pointer to
3041 * NULL. May be called at any time after the structure is initialized.
3042 */
3043 #endif /* SIMPLIFIED_READ */
3044
3045 #ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED
3046 #ifdef PNG_STDIO_SUPPORTED
3047 /* WRITE APIS
3048 * ----------
3049 * For write you must initialize a png_image structure to describe the image to
3050 * be written. To do this use memset to set the whole structure to 0 then
3051 * initialize fields describing your image.
3052 *
3053 * version: must be set to PNG_IMAGE_VERSION
3054 * opaque: must be initialized to NULL
3055 * width: image width in pixels
3056 * height: image height in rows
3057 * format: the format of the data (image and color-map) you wish to write
3058 * flags: set to 0 unless one of the defined flags applies; set
3059 * PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB for color format images where the RGB
3060 * values do not correspond to the colors in sRGB.
3061 * colormap_entries: set to the number of entries in the color-map (0 to 256)
3062 */
3063 PNG_EXPORT(239, int, png_image_write_to_file, (png_imagep image,
3064 const char *file, int convert_to_8bit, const void *buffer,
3065 png_int_32 row_stride, const void *colormap));
3066 /* Write the image to the named file. */
3067
3068 PNG_EXPORT(240, int, png_image_write_to_stdio, (png_imagep image, FILE *file,
3069 int convert_to_8_bit, const void *buffer, png_int_32 row_stride,
3070 const void *colormap));
3071 /* Write the image to the given (FILE*). */
3072
3073 /* With both write APIs if image is in one of the linear formats with 16-bit
3074 * data then setting convert_to_8_bit will cause the output to be an 8-bit PNG
3075 * gamma encoded according to the sRGB specification, otherwise a 16-bit linear
3076 * encoded PNG file is written.
3077 *
3078 * With color-mapped data formats the colormap parameter point to a color-map
3079 * with at least image->colormap_entries encoded in the specified format. If
3080 * the format is linear the written PNG color-map will be converted to sRGB
3081 * regardless of the convert_to_8_bit flag.
3082 *
3083 * With all APIs row_stride is handled as in the read APIs - it is the spacing
3084 * from one row to the next in component sized units (1 or 2 bytes) and if
3085 * negative indicates a bottom-up row layout in the buffer. If row_stride is zero,
3086 * libpng will calculate it for you from the image width and number of channels.
3087 *
3088 * Note that the write API does not support interlacing, sub-8-bit pixels, indexed
3089 * PNG (color_type 3) or most ancillary chunks.
3090 */
3091 #endif /* STDIO */
3092 #endif /* SIMPLIFIED_WRITE */
3093 /*******************************************************************************
3094 * END OF SIMPLIFIED API
3095 ******************************************************************************/
3096 #endif /* SIMPLIFIED_{READ|WRITE} */
3097
3098 /*******************************************************************************
3099 * Section 6: IMPLEMENTATION OPTIONS
3100 *******************************************************************************
3101 *
3102 * Support for arbitrary implementation-specific optimizations. The API allows
3103 * particular options to be turned on or off. 'Option' is the number of the
3104 * option and 'onoff' is 0 (off) or non-0 (on). The value returned is given
3105 * by the PNG_OPTION_ defines below.
3106 *
3107 * HARDWARE: normally hardware capabilites, such as the Intel SSE instructions,
3108 * are detected at run time, however sometimes it may be impossible
3109 * to do this in user mode, in which case it is necessary to discover
3110 * the capabilities in an OS specific way. Such capabilities are
3111 * listed here when libpng has support for them and must be turned
3112 * ON by the application if present.
3113 *
3114 * SOFTWARE: sometimes software optimizations actually result in performance
3115 * decrease on some architectures or systems, or with some sets of
3116 * PNG images. 'Software' options allow such optimizations to be
3117 * selected at run time.
3118 */
3119 #ifdef PNG_SET_OPTION_SUPPORTED
3120 #ifdef PNG_ARM_NEON_API_SUPPORTED
3121 # define PNG_ARM_NEON 0 /* HARDWARE: ARM Neon SIMD instructions supported */
3122 #endif
3123 #define PNG_MAXIMUM_INFLATE_WINDOW 2 /* SOFTWARE: force maximum window */
3124 #define PNG_SKIP_sRGB_CHECK_PROFILE 4 /* SOFTWARE: Check ICC profile for sRGB */
3125 #define PNG_OPTION_NEXT 6 /* Next option - numbers must be even */
3126
3127 /* Return values: NOTE: there are four values and 'off' is *not* zero */
3128 #define PNG_OPTION_UNSET 0 /* Unset - defaults to off */
3129 #define PNG_OPTION_INVALID 1 /* Option number out of range */
3130 #define PNG_OPTION_OFF 2
3131 #define PNG_OPTION_ON 3
3132
3133 PNG_EXPORT(244, int, png_set_option, (png_structrp png_ptr, int option,
3134 int onoff));
3135 #endif /* SET_OPTION */
3136
3137 /*******************************************************************************
3138 * END OF HARDWARE AND SOFTWARE OPTIONS
3139 ******************************************************************************/
3140
3141 /* Maintainer: Put new public prototypes here ^, in libpng.3, in project
3142 * defs, and in scripts/symbols.def.
3143 */
3144
3145 /* The last ordinal number (this is the *last* one already used; the next
3146 * one to use is one more than this.)
3147 */
3148 #ifdef PNG_EXPORT_LAST_ORDINAL
3149 PNG_EXPORT_LAST_ORDINAL(244);
3150 #endif
3151
3152 #ifdef __cplusplus
3153 }
3154 #endif
3155
3156 #endif /* PNG_VERSION_INFO_ONLY */
3157 /* Do not put anything past this line */
3158 #endif /* PNG_H */