c83051b1ca7949f45ca0a5cfaa71e9456cb1c790
[reactos.git] / reactos / include / reactos / libs / libpng / png.h
1
2 /* png.h - header file for PNG reference library
3 *
4 * libpng version 1.6.19, November 12, 2015
5 *
6 * Copyright (c) 1998-2015 Glenn Randers-Pehrson
7 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
8 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
9 *
10 * This code is released under the libpng license (See LICENSE, below)
11 *
12 * Authors and maintainers:
13 * libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
14 * libpng versions 0.89, June 1996, through 0.96, May 1997: Andreas Dilger
15 * libpng versions 0.97, January 1998, through 1.6.19, November 12, 2015: Glenn
16 * See also "Contributing Authors", below.
17 */
18
19 /*
20 * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
21 *
22 * If you modify libpng you may insert additional notices immediately following
23 * this sentence.
24 *
25 * This code is released under the libpng license.
26 *
27 * libpng versions 1.0.7, July 1, 2000, through 1.6.19, November 12, 2015, are
28 * Copyright (c) 2000-2002, 2004, 2006-2015 Glenn Randers-Pehrson, are
29 * derived from libpng-1.0.6, and are distributed according to the same
30 * disclaimer and license as libpng-1.0.6 with the following individuals
31 * added to the list of Contributing Authors:
32 *
33 * Simon-Pierre Cadieux
34 * Eric S. Raymond
35 * Mans Rullgard
36 * Cosmin Truta
37 * Gilles Vollant
38 * James Yu
39 *
40 * and with the following additions to the disclaimer:
41 *
42 * There is no warranty against interference with your enjoyment of the
43 * library or against infringement. There is no warranty that our
44 * efforts or the library will fulfill any of your particular purposes
45 * or needs. This library is provided with all faults, and the entire
46 * risk of satisfactory quality, performance, accuracy, and effort is with
47 * the user.
48 *
49 * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
50 * Copyright (c) 1998-2000 Glenn Randers-Pehrson, are derived from
51 * libpng-0.96, and are distributed according to the same disclaimer and
52 * license as libpng-0.96, with the following individuals added to the list
53 * of Contributing Authors:
54 *
55 * Tom Lane
56 * Glenn Randers-Pehrson
57 * Willem van Schaik
58 *
59 * libpng versions 0.89, June 1996, through 0.96, May 1997, are
60 * Copyright (c) 1996-1997 Andreas Dilger, are derived from libpng-0.88,
61 * and are distributed according to the same disclaimer and license as
62 * libpng-0.88, with the following individuals added to the list of
63 * Contributing Authors:
64 *
65 * John Bowler
66 * Kevin Bracey
67 * Sam Bushell
68 * Magnus Holmgren
69 * Greg Roelofs
70 * Tom Tanner
71 *
72 * libpng versions 0.5, May 1995, through 0.88, January 1996, are
73 * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
74 *
75 * For the purposes of this copyright and license, "Contributing Authors"
76 * is defined as the following set of individuals:
77 *
78 * Andreas Dilger
79 * Dave Martindale
80 * Guy Eric Schalnat
81 * Paul Schmidt
82 * Tim Wegner
83 *
84 * The PNG Reference Library is supplied "AS IS". The Contributing Authors
85 * and Group 42, Inc. disclaim all warranties, expressed or implied,
86 * including, without limitation, the warranties of merchantability and of
87 * fitness for any purpose. The Contributing Authors and Group 42, Inc.
88 * assume no liability for direct, indirect, incidental, special, exemplary,
89 * or consequential damages, which may result from the use of the PNG
90 * Reference Library, even if advised of the possibility of such damage.
91 *
92 * Permission is hereby granted to use, copy, modify, and distribute this
93 * source code, or portions hereof, for any purpose, without fee, subject
94 * to the following restrictions:
95 *
96 * 1. The origin of this source code must not be misrepresented.
97 *
98 * 2. Altered versions must be plainly marked as such and must not
99 * be misrepresented as being the original source.
100 *
101 * 3. This Copyright notice may not be removed or altered from any
102 * source or altered source distribution.
103 *
104 * The Contributing Authors and Group 42, Inc. specifically permit, without
105 * fee, and encourage the use of this source code as a component to
106 * supporting the PNG file format in commercial products. If you use this
107 * source code in a product, acknowledgment is not required but would be
108 * appreciated.
109 *
110 * END OF COPYRIGHT NOTICE, DISCLAIMER, and LICENSE.
111 */
112
113 /*
114 * A "png_get_copyright" function is available, for convenient use in "about"
115 * boxes and the like:
116 *
117 * printf("%s", png_get_copyright(NULL));
118 *
119 * Also, the PNG logo (in PNG format, of course) is supplied in the
120 * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
121 */
122
123 /*
124 * Libpng is OSI Certified Open Source Software. OSI Certified Open Source is
125 * a certification mark of the Open Source Initiative. OSI has not addressed
126 * the additional disclaimers inserted at version 1.0.7.
127 */
128
129 /*
130 * The contributing authors would like to thank all those who helped
131 * with testing, bug fixes, and patience. This wouldn't have been
132 * possible without all of you.
133 *
134 * Thanks to Frank J. T. Wojcik for helping with the documentation.
135 */
136
137 /* Note about libpng version numbers:
138 *
139 * Due to various miscommunications, unforeseen code incompatibilities
140 * and occasional factors outside the authors' control, version numbering
141 * on the library has not always been consistent and straightforward.
142 * The following table summarizes matters since version 0.89c, which was
143 * the first widely used release:
144 *
145 * source png.h png.h shared-lib
146 * version string int version
147 * ------- ------ ----- ----------
148 * 0.89c "1.0 beta 3" 0.89 89 1.0.89
149 * 0.90 "1.0 beta 4" 0.90 90 0.90 [should have been 2.0.90]
150 * 0.95 "1.0 beta 5" 0.95 95 0.95 [should have been 2.0.95]
151 * 0.96 "1.0 beta 6" 0.96 96 0.96 [should have been 2.0.96]
152 * 0.97b "1.00.97 beta 7" 1.00.97 97 1.0.1 [should have been 2.0.97]
153 * 0.97c 0.97 97 2.0.97
154 * 0.98 0.98 98 2.0.98
155 * 0.99 0.99 98 2.0.99
156 * 0.99a-m 0.99 99 2.0.99
157 * 1.00 1.00 100 2.1.0 [100 should be 10000]
158 * 1.0.0 (from here on, the 100 2.1.0 [100 should be 10000]
159 * 1.0.1 png.h string is 10001 2.1.0
160 * 1.0.1a-e identical to the 10002 from here on, the shared library
161 * 1.0.2 source version) 10002 is 2.V where V is the source code
162 * 1.0.2a-b 10003 version, except as noted.
163 * 1.0.3 10003
164 * 1.0.3a-d 10004
165 * 1.0.4 10004
166 * 1.0.4a-f 10005
167 * 1.0.5 (+ 2 patches) 10005
168 * 1.0.5a-d 10006
169 * 1.0.5e-r 10100 (not source compatible)
170 * 1.0.5s-v 10006 (not binary compatible)
171 * 1.0.6 (+ 3 patches) 10006 (still binary incompatible)
172 * 1.0.6d-f 10007 (still binary incompatible)
173 * 1.0.6g 10007
174 * 1.0.6h 10007 10.6h (testing xy.z so-numbering)
175 * 1.0.6i 10007 10.6i
176 * 1.0.6j 10007 2.1.0.6j (incompatible with 1.0.0)
177 * 1.0.7beta11-14 DLLNUM 10007 2.1.0.7beta11-14 (binary compatible)
178 * 1.0.7beta15-18 1 10007 2.1.0.7beta15-18 (binary compatible)
179 * 1.0.7rc1-2 1 10007 2.1.0.7rc1-2 (binary compatible)
180 * 1.0.7 1 10007 (still compatible)
181 * ...
182 * 1.0.19 10 10019 10.so.0.19[.0]
183 * ...
184 * 1.2.53 13 10253 12.so.0.53[.0]
185 * ...
186 * 1.5.23 15 10523 15.so.15.23[.0]
187 * ...
188 * 1.6.19 16 10619 16.so.16.19[.0]
189 *
190 * Henceforth the source version will match the shared-library major
191 * and minor numbers; the shared-library major version number will be
192 * used for changes in backward compatibility, as it is intended. The
193 * PNG_LIBPNG_VER macro, which is not used within libpng but is available
194 * for applications, is an unsigned integer of the form xyyzz corresponding
195 * to the source version x.y.z (leading zeros in y and z). Beta versions
196 * were given the previous public release number plus a letter, until
197 * version 1.0.6j; from then on they were given the upcoming public
198 * release number plus "betaNN" or "rcNN".
199 *
200 * Binary incompatibility exists only when applications make direct access
201 * to the info_ptr or png_ptr members through png.h, and the compiled
202 * application is loaded with a different version of the library.
203 *
204 * DLLNUM will change each time there are forward or backward changes
205 * in binary compatibility (e.g., when a new feature is added).
206 *
207 * See libpng.txt or libpng.3 for more information. The PNG specification
208 * is available as a W3C Recommendation and as an ISO Specification,
209 * <http://www.w3.org/TR/2003/REC-PNG-20031110/
210 */
211
212 /*
213 * Y2K compliance in libpng:
214 * =========================
215 *
216 * November 12, 2015
217 *
218 * Since the PNG Development group is an ad-hoc body, we can't make
219 * an official declaration.
220 *
221 * This is your unofficial assurance that libpng from version 0.71 and
222 * upward through 1.6.19 are Y2K compliant. It is my belief that
223 * earlier versions were also Y2K compliant.
224 *
225 * Libpng only has two year fields. One is a 2-byte unsigned integer
226 * that will hold years up to 65535. The other, which is deprecated,
227 * holds the date in text format, and will hold years up to 9999.
228 *
229 * The integer is
230 * "png_uint_16 year" in png_time_struct.
231 *
232 * The string is
233 * "char time_buffer[29]" in png_struct. This is no longer used
234 * in libpng-1.6.x and will be removed from libpng-1.7.0.
235 *
236 * There are seven time-related functions:
237 * png.c: png_convert_to_rfc_1123_buffer() in png.c
238 * (formerly png_convert_to_rfc_1123() prior to libpng-1.5.x and
239 * png_convert_to_rfc_1152() in error prior to libpng-0.98)
240 * png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
241 * png_convert_from_time_t() in pngwrite.c
242 * png_get_tIME() in pngget.c
243 * png_handle_tIME() in pngrutil.c, called in pngread.c
244 * png_set_tIME() in pngset.c
245 * png_write_tIME() in pngwutil.c, called in pngwrite.c
246 *
247 * All handle dates properly in a Y2K environment. The
248 * png_convert_from_time_t() function calls gmtime() to convert from system
249 * clock time, which returns (year - 1900), which we properly convert to
250 * the full 4-digit year. There is a possibility that libpng applications
251 * are not passing 4-digit years into the png_convert_to_rfc_1123_buffer()
252 * function, or that they are incorrectly passing only a 2-digit year
253 * instead of "year - 1900" into the png_convert_from_struct_tm() function,
254 * but this is not under our control. The libpng documentation has always
255 * stated that it works with 4-digit years, and the APIs have been
256 * documented as such.
257 *
258 * The tIME chunk itself is also Y2K compliant. It uses a 2-byte unsigned
259 * integer to hold the year, and can hold years as large as 65535.
260 *
261 * zlib, upon which libpng depends, is also Y2K compliant. It contains
262 * no date-related code.
263 *
264 * Glenn Randers-Pehrson
265 * libpng maintainer
266 * PNG Development Group
267 */
268
269 #ifndef PNG_H
270 #define PNG_H
271
272 /* This is not the place to learn how to use libpng. The file libpng-manual.txt
273 * describes how to use libpng, and the file example.c summarizes it
274 * with some code on which to build. This file is useful for looking
275 * at the actual function definitions and structure components. If that
276 * file has been stripped from your copy of libpng, you can find it at
277 * <http://www.libpng.org/pub/png/libpng-manual.txt>
278 *
279 * If you just need to read a PNG file and don't want to read the documentation
280 * skip to the end of this file and read the section entitled 'simplified API'.
281 */
282
283 /* Version information for png.h - this should match the version in png.c */
284 #define PNG_LIBPNG_VER_STRING "1.6.19"
285 #define PNG_HEADER_VERSION_STRING \
286 " libpng version 1.6.19 - November 12, 2015\n"
287
288 #define PNG_LIBPNG_VER_SONUM 16
289 #define PNG_LIBPNG_VER_DLLNUM 16
290
291 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
292 #define PNG_LIBPNG_VER_MAJOR 1
293 #define PNG_LIBPNG_VER_MINOR 6
294 #define PNG_LIBPNG_VER_RELEASE 19
295
296 /* This should match the numeric part of the final component of
297 * PNG_LIBPNG_VER_STRING, omitting any leading zero:
298 */
299
300 #define PNG_LIBPNG_VER_BUILD 0
301
302 /* Release Status */
303 #define PNG_LIBPNG_BUILD_ALPHA 1
304 #define PNG_LIBPNG_BUILD_BETA 2
305 #define PNG_LIBPNG_BUILD_RC 3
306 #define PNG_LIBPNG_BUILD_STABLE 4
307 #define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7
308
309 /* Release-Specific Flags */
310 #define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with
311 PNG_LIBPNG_BUILD_STABLE only */
312 #define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with
313 PNG_LIBPNG_BUILD_SPECIAL */
314 #define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with
315 PNG_LIBPNG_BUILD_PRIVATE */
316
317 #define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE
318
319 /* Careful here. At one time, Guy wanted to use 082, but that would be octal.
320 * We must not include leading zeros.
321 * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only
322 * version 1.0.0 was mis-numbered 100 instead of 10000). From
323 * version 1.0.1 it's xxyyzz, where x=major, y=minor, z=release
324 */
325 #define PNG_LIBPNG_VER 10619 /* 1.6.19 */
326
327 /* Library configuration: these options cannot be changed after
328 * the library has been built.
329 */
330 #ifndef PNGLCONF_H
331 /* If pnglibconf.h is missing, you can
332 * copy scripts/pnglibconf.h.prebuilt to pnglibconf.h
333 */
334 # include "pnglibconf.h"
335 #endif
336
337 #ifndef PNG_VERSION_INFO_ONLY
338 /* Machine specific configuration. */
339 # include "pngconf.h"
340 #endif
341
342 /*
343 * Added at libpng-1.2.8
344 *
345 * Ref MSDN: Private as priority over Special
346 * VS_FF_PRIVATEBUILD File *was not* built using standard release
347 * procedures. If this value is given, the StringFileInfo block must
348 * contain a PrivateBuild string.
349 *
350 * VS_FF_SPECIALBUILD File *was* built by the original company using
351 * standard release procedures but is a variation of the standard
352 * file of the same version number. If this value is given, the
353 * StringFileInfo block must contain a SpecialBuild string.
354 */
355
356 #ifdef PNG_USER_PRIVATEBUILD /* From pnglibconf.h */
357 # define PNG_LIBPNG_BUILD_TYPE \
358 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE)
359 #else
360 # ifdef PNG_LIBPNG_SPECIALBUILD
361 # define PNG_LIBPNG_BUILD_TYPE \
362 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL)
363 # else
364 # define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE)
365 # endif
366 #endif
367
368 #ifndef PNG_VERSION_INFO_ONLY
369
370 /* Inhibit C++ name-mangling for libpng functions but not for system calls. */
371 #ifdef __cplusplus
372 extern "C" {
373 #endif /* __cplusplus */
374
375 /* Version information for C files, stored in png.c. This had better match
376 * the version above.
377 */
378 #define png_libpng_ver png_get_header_ver(NULL)
379
380 /* This file is arranged in several sections:
381 *
382 * 1. [omitted]
383 * 2. Any configuration options that can be specified by for the application
384 * code when it is built. (Build time configuration is in pnglibconf.h)
385 * 3. Type definitions (base types are defined in pngconf.h), structure
386 * definitions.
387 * 4. Exported library functions.
388 * 5. Simplified API.
389 * 6. Implementation options.
390 *
391 * The library source code has additional files (principally pngpriv.h) that
392 * allow configuration of the library.
393 */
394
395 /* Section 1: [omitted] */
396
397 /* Section 2: run time configuration
398 * See pnglibconf.h for build time configuration
399 *
400 * Run time configuration allows the application to choose between
401 * implementations of certain arithmetic APIs. The default is set
402 * at build time and recorded in pnglibconf.h, but it is safe to
403 * override these (and only these) settings. Note that this won't
404 * change what the library does, only application code, and the
405 * settings can (and probably should) be made on a per-file basis
406 * by setting the #defines before including png.h
407 *
408 * Use macros to read integers from PNG data or use the exported
409 * functions?
410 * PNG_USE_READ_MACROS: use the macros (see below) Note that
411 * the macros evaluate their argument multiple times.
412 * PNG_NO_USE_READ_MACROS: call the relevant library function.
413 *
414 * Use the alternative algorithm for compositing alpha samples that
415 * does not use division?
416 * PNG_READ_COMPOSITE_NODIV_SUPPORTED: use the 'no division'
417 * algorithm.
418 * PNG_NO_READ_COMPOSITE_NODIV: use the 'division' algorithm.
419 *
420 * How to handle benign errors if PNG_ALLOW_BENIGN_ERRORS is
421 * false?
422 * PNG_ALLOW_BENIGN_ERRORS: map calls to the benign error
423 * APIs to png_warning.
424 * Otherwise the calls are mapped to png_error.
425 */
426
427 /* Section 3: type definitions, including structures and compile time
428 * constants.
429 * See pngconf.h for base types that vary by machine/system
430 */
431
432 /* This triggers a compiler error in png.c, if png.c and png.h
433 * do not agree upon the version number.
434 */
435 typedef char* png_libpng_version_1_6_19;
436
437 /* Basic control structions. Read libpng-manual.txt or libpng.3 for more info.
438 *
439 * png_struct is the cache of information used while reading or writing a single
440 * PNG file. One of these is always required, although the simplified API
441 * (below) hides the creation and destruction of it.
442 */
443 typedef struct png_struct_def png_struct;
444 typedef const png_struct * png_const_structp;
445 typedef png_struct * png_structp;
446 typedef png_struct * * png_structpp;
447
448 /* png_info contains information read from or to be written to a PNG file. One
449 * or more of these must exist while reading or creating a PNG file. The
450 * information is not used by libpng during read but is used to control what
451 * gets written when a PNG file is created. "png_get_" function calls read
452 * information during read and "png_set_" functions calls write information
453 * when creating a PNG.
454 * been moved into a separate header file that is not accessible to
455 * applications. Read libpng-manual.txt or libpng.3 for more info.
456 */
457 typedef struct png_info_def png_info;
458 typedef png_info * png_infop;
459 typedef const png_info * png_const_infop;
460 typedef png_info * * png_infopp;
461
462 /* Types with names ending 'p' are pointer types. The corresponding types with
463 * names ending 'rp' are identical pointer types except that the pointer is
464 * marked 'restrict', which means that it is the only pointer to the object
465 * passed to the function. Applications should not use the 'restrict' types;
466 * it is always valid to pass 'p' to a pointer with a function argument of the
467 * corresponding 'rp' type. Different compilers have different rules with
468 * regard to type matching in the presence of 'restrict'. For backward
469 * compatibility libpng callbacks never have 'restrict' in their parameters and,
470 * consequentially, writing portable application code is extremely difficult if
471 * an attempt is made to use 'restrict'.
472 */
473 typedef png_struct * PNG_RESTRICT png_structrp;
474 typedef const png_struct * PNG_RESTRICT png_const_structrp;
475 typedef png_info * PNG_RESTRICT png_inforp;
476 typedef const png_info * PNG_RESTRICT png_const_inforp;
477
478 /* Three color definitions. The order of the red, green, and blue, (and the
479 * exact size) is not important, although the size of the fields need to
480 * be png_byte or png_uint_16 (as defined below).
481 */
482 typedef struct png_color_struct
483 {
484 png_byte red;
485 png_byte green;
486 png_byte blue;
487 } png_color;
488 typedef png_color * png_colorp;
489 typedef const png_color * png_const_colorp;
490 typedef png_color * * png_colorpp;
491
492 typedef struct png_color_16_struct
493 {
494 png_byte index; /* used for palette files */
495 png_uint_16 red; /* for use in red green blue files */
496 png_uint_16 green;
497 png_uint_16 blue;
498 png_uint_16 gray; /* for use in grayscale files */
499 } png_color_16;
500 typedef png_color_16 * png_color_16p;
501 typedef const png_color_16 * png_const_color_16p;
502 typedef png_color_16 * * png_color_16pp;
503
504 typedef struct png_color_8_struct
505 {
506 png_byte red; /* for use in red green blue files */
507 png_byte green;
508 png_byte blue;
509 png_byte gray; /* for use in grayscale files */
510 png_byte alpha; /* for alpha channel files */
511 } png_color_8;
512 typedef png_color_8 * png_color_8p;
513 typedef const png_color_8 * png_const_color_8p;
514 typedef png_color_8 * * png_color_8pp;
515
516 /*
517 * The following two structures are used for the in-core representation
518 * of sPLT chunks.
519 */
520 typedef struct png_sPLT_entry_struct
521 {
522 png_uint_16 red;
523 png_uint_16 green;
524 png_uint_16 blue;
525 png_uint_16 alpha;
526 png_uint_16 frequency;
527 } png_sPLT_entry;
528 typedef png_sPLT_entry * png_sPLT_entryp;
529 typedef const png_sPLT_entry * png_const_sPLT_entryp;
530 typedef png_sPLT_entry * * png_sPLT_entrypp;
531
532 /* When the depth of the sPLT palette is 8 bits, the color and alpha samples
533 * occupy the LSB of their respective members, and the MSB of each member
534 * is zero-filled. The frequency member always occupies the full 16 bits.
535 */
536
537 typedef struct png_sPLT_struct
538 {
539 png_charp name; /* palette name */
540 png_byte depth; /* depth of palette samples */
541 png_sPLT_entryp entries; /* palette entries */
542 png_int_32 nentries; /* number of palette entries */
543 } png_sPLT_t;
544 typedef png_sPLT_t * png_sPLT_tp;
545 typedef const png_sPLT_t * png_const_sPLT_tp;
546 typedef png_sPLT_t * * png_sPLT_tpp;
547
548 #ifdef PNG_TEXT_SUPPORTED
549 /* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,
550 * and whether that contents is compressed or not. The "key" field
551 * points to a regular zero-terminated C string. The "text" fields can be a
552 * regular C string, an empty string, or a NULL pointer.
553 * However, the structure returned by png_get_text() will always contain
554 * the "text" field as a regular zero-terminated C string (possibly
555 * empty), never a NULL pointer, so it can be safely used in printf() and
556 * other string-handling functions. Note that the "itxt_length", "lang", and
557 * "lang_key" members of the structure only exist when the library is built
558 * with iTXt chunk support. Prior to libpng-1.4.0 the library was built by
559 * default without iTXt support. Also note that when iTXt *is* supported,
560 * the "lang" and "lang_key" fields contain NULL pointers when the
561 * "compression" field contains * PNG_TEXT_COMPRESSION_NONE or
562 * PNG_TEXT_COMPRESSION_zTXt. Note that the "compression value" is not the
563 * same as what appears in the PNG tEXt/zTXt/iTXt chunk's "compression flag"
564 * which is always 0 or 1, or its "compression method" which is always 0.
565 */
566 typedef struct png_text_struct
567 {
568 int compression; /* compression value:
569 -1: tEXt, none
570 0: zTXt, deflate
571 1: iTXt, none
572 2: iTXt, deflate */
573 png_charp key; /* keyword, 1-79 character description of "text" */
574 png_charp text; /* comment, may be an empty string (ie "")
575 or a NULL pointer */
576 png_size_t text_length; /* length of the text string */
577 png_size_t itxt_length; /* length of the itxt string */
578 png_charp lang; /* language code, 0-79 characters
579 or a NULL pointer */
580 png_charp lang_key; /* keyword translated UTF-8 string, 0 or more
581 chars or a NULL pointer */
582 } png_text;
583 typedef png_text * png_textp;
584 typedef const png_text * png_const_textp;
585 typedef png_text * * png_textpp;
586 #endif
587
588 /* Supported compression types for text in PNG files (tEXt, and zTXt).
589 * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */
590 #define PNG_TEXT_COMPRESSION_NONE_WR -3
591 #define PNG_TEXT_COMPRESSION_zTXt_WR -2
592 #define PNG_TEXT_COMPRESSION_NONE -1
593 #define PNG_TEXT_COMPRESSION_zTXt 0
594 #define PNG_ITXT_COMPRESSION_NONE 1
595 #define PNG_ITXT_COMPRESSION_zTXt 2
596 #define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */
597
598 /* png_time is a way to hold the time in an machine independent way.
599 * Two conversions are provided, both from time_t and struct tm. There
600 * is no portable way to convert to either of these structures, as far
601 * as I know. If you know of a portable way, send it to me. As a side
602 * note - PNG has always been Year 2000 compliant!
603 */
604 typedef struct png_time_struct
605 {
606 png_uint_16 year; /* full year, as in, 1995 */
607 png_byte month; /* month of year, 1 - 12 */
608 png_byte day; /* day of month, 1 - 31 */
609 png_byte hour; /* hour of day, 0 - 23 */
610 png_byte minute; /* minute of hour, 0 - 59 */
611 png_byte second; /* second of minute, 0 - 60 (for leap seconds) */
612 } png_time;
613 typedef png_time * png_timep;
614 typedef const png_time * png_const_timep;
615 typedef png_time * * png_timepp;
616
617 #if defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) ||\
618 defined(PNG_USER_CHUNKS_SUPPORTED)
619 /* png_unknown_chunk is a structure to hold queued chunks for which there is
620 * no specific support. The idea is that we can use this to queue
621 * up private chunks for output even though the library doesn't actually
622 * know about their semantics.
623 *
624 * The data in the structure is set by libpng on read and used on write.
625 */
626 typedef struct png_unknown_chunk_t
627 {
628 png_byte name[5]; /* Textual chunk name with '\0' terminator */
629 png_byte *data; /* Data, should not be modified on read! */
630 png_size_t size;
631
632 /* On write 'location' must be set using the flag values listed below.
633 * Notice that on read it is set by libpng however the values stored have
634 * more bits set than are listed below. Always treat the value as a
635 * bitmask. On write set only one bit - setting multiple bits may cause the
636 * chunk to be written in multiple places.
637 */
638 png_byte location; /* mode of operation at read time */
639 }
640 png_unknown_chunk;
641
642 typedef png_unknown_chunk * png_unknown_chunkp;
643 typedef const png_unknown_chunk * png_const_unknown_chunkp;
644 typedef png_unknown_chunk * * png_unknown_chunkpp;
645 #endif
646
647 /* Flag values for the unknown chunk location byte. */
648 #define PNG_HAVE_IHDR 0x01
649 #define PNG_HAVE_PLTE 0x02
650 #define PNG_AFTER_IDAT 0x08
651
652 /* Maximum positive integer used in PNG is (2^31)-1 */
653 #define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL)
654 #define PNG_UINT_32_MAX ((png_uint_32)(-1))
655 #define PNG_SIZE_MAX ((png_size_t)(-1))
656
657 /* These are constants for fixed point values encoded in the
658 * PNG specification manner (x100000)
659 */
660 #define PNG_FP_1 100000
661 #define PNG_FP_HALF 50000
662 #define PNG_FP_MAX ((png_fixed_point)0x7fffffffL)
663 #define PNG_FP_MIN (-PNG_FP_MAX)
664
665 /* These describe the color_type field in png_info. */
666 /* color type masks */
667 #define PNG_COLOR_MASK_PALETTE 1
668 #define PNG_COLOR_MASK_COLOR 2
669 #define PNG_COLOR_MASK_ALPHA 4
670
671 /* color types. Note that not all combinations are legal */
672 #define PNG_COLOR_TYPE_GRAY 0
673 #define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
674 #define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR)
675 #define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
676 #define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
677 /* aliases */
678 #define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA
679 #define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA
680
681 /* This is for compression type. PNG 1.0-1.2 only define the single type. */
682 #define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */
683 #define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE
684
685 /* This is for filter type. PNG 1.0-1.2 only define the single type. */
686 #define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */
687 #define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */
688 #define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE
689
690 /* These are for the interlacing type. These values should NOT be changed. */
691 #define PNG_INTERLACE_NONE 0 /* Non-interlaced image */
692 #define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */
693 #define PNG_INTERLACE_LAST 2 /* Not a valid value */
694
695 /* These are for the oFFs chunk. These values should NOT be changed. */
696 #define PNG_OFFSET_PIXEL 0 /* Offset in pixels */
697 #define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */
698 #define PNG_OFFSET_LAST 2 /* Not a valid value */
699
700 /* These are for the pCAL chunk. These values should NOT be changed. */
701 #define PNG_EQUATION_LINEAR 0 /* Linear transformation */
702 #define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */
703 #define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */
704 #define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */
705 #define PNG_EQUATION_LAST 4 /* Not a valid value */
706
707 /* These are for the sCAL chunk. These values should NOT be changed. */
708 #define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */
709 #define PNG_SCALE_METER 1 /* meters per pixel */
710 #define PNG_SCALE_RADIAN 2 /* radians per pixel */
711 #define PNG_SCALE_LAST 3 /* Not a valid value */
712
713 /* These are for the pHYs chunk. These values should NOT be changed. */
714 #define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */
715 #define PNG_RESOLUTION_METER 1 /* pixels/meter */
716 #define PNG_RESOLUTION_LAST 2 /* Not a valid value */
717
718 /* These are for the sRGB chunk. These values should NOT be changed. */
719 #define PNG_sRGB_INTENT_PERCEPTUAL 0
720 #define PNG_sRGB_INTENT_RELATIVE 1
721 #define PNG_sRGB_INTENT_SATURATION 2
722 #define PNG_sRGB_INTENT_ABSOLUTE 3
723 #define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */
724
725 /* This is for text chunks */
726 #define PNG_KEYWORD_MAX_LENGTH 79
727
728 /* Maximum number of entries in PLTE/sPLT/tRNS arrays */
729 #define PNG_MAX_PALETTE_LENGTH 256
730
731 /* These determine if an ancillary chunk's data has been successfully read
732 * from the PNG header, or if the application has filled in the corresponding
733 * data in the info_struct to be written into the output file. The values
734 * of the PNG_INFO_<chunk> defines should NOT be changed.
735 */
736 #define PNG_INFO_gAMA 0x0001
737 #define PNG_INFO_sBIT 0x0002
738 #define PNG_INFO_cHRM 0x0004
739 #define PNG_INFO_PLTE 0x0008
740 #define PNG_INFO_tRNS 0x0010
741 #define PNG_INFO_bKGD 0x0020
742 #define PNG_INFO_hIST 0x0040
743 #define PNG_INFO_pHYs 0x0080
744 #define PNG_INFO_oFFs 0x0100
745 #define PNG_INFO_tIME 0x0200
746 #define PNG_INFO_pCAL 0x0400
747 #define PNG_INFO_sRGB 0x0800 /* GR-P, 0.96a */
748 #define PNG_INFO_iCCP 0x1000 /* ESR, 1.0.6 */
749 #define PNG_INFO_sPLT 0x2000 /* ESR, 1.0.6 */
750 #define PNG_INFO_sCAL 0x4000 /* ESR, 1.0.6 */
751 #if INT_MAX >= 0x8000 /* else this might break */
752 #define PNG_INFO_IDAT 0x8000 /* ESR, 1.0.6 */
753 #endif
754
755 /* This is used for the transformation routines, as some of them
756 * change these values for the row. It also should enable using
757 * the routines for other purposes.
758 */
759 typedef struct png_row_info_struct
760 {
761 png_uint_32 width; /* width of row */
762 png_size_t rowbytes; /* number of bytes in row */
763 png_byte color_type; /* color type of row */
764 png_byte bit_depth; /* bit depth of row */
765 png_byte channels; /* number of channels (1, 2, 3, or 4) */
766 png_byte pixel_depth; /* bits per pixel (depth * channels) */
767 } png_row_info;
768
769 typedef png_row_info * png_row_infop;
770 typedef png_row_info * * png_row_infopp;
771
772 /* These are the function types for the I/O functions and for the functions
773 * that allow the user to override the default I/O functions with his or her
774 * own. The png_error_ptr type should match that of user-supplied warning
775 * and error functions, while the png_rw_ptr type should match that of the
776 * user read/write data functions. Note that the 'write' function must not
777 * modify the buffer it is passed. The 'read' function, on the other hand, is
778 * expected to return the read data in the buffer.
779 */
780 typedef PNG_CALLBACK(void, *png_error_ptr, (png_structp, png_const_charp));
781 typedef PNG_CALLBACK(void, *png_rw_ptr, (png_structp, png_bytep, png_size_t));
782 typedef PNG_CALLBACK(void, *png_flush_ptr, (png_structp));
783 typedef PNG_CALLBACK(void, *png_read_status_ptr, (png_structp, png_uint_32,
784 int));
785 typedef PNG_CALLBACK(void, *png_write_status_ptr, (png_structp, png_uint_32,
786 int));
787
788 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
789 typedef PNG_CALLBACK(void, *png_progressive_info_ptr, (png_structp, png_infop));
790 typedef PNG_CALLBACK(void, *png_progressive_end_ptr, (png_structp, png_infop));
791
792 /* The following callback receives png_uint_32 row_number, int pass for the
793 * png_bytep data of the row. When transforming an interlaced image the
794 * row number is the row number within the sub-image of the interlace pass, so
795 * the value will increase to the height of the sub-image (not the full image)
796 * then reset to 0 for the next pass.
797 *
798 * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
799 * find the output pixel (x,y) given an interlaced sub-image pixel
800 * (row,col,pass). (See below for these macros.)
801 */
802 typedef PNG_CALLBACK(void, *png_progressive_row_ptr, (png_structp, png_bytep,
803 png_uint_32, int));
804 #endif
805
806 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
807 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
808 typedef PNG_CALLBACK(void, *png_user_transform_ptr, (png_structp, png_row_infop,
809 png_bytep));
810 #endif
811
812 #ifdef PNG_USER_CHUNKS_SUPPORTED
813 typedef PNG_CALLBACK(int, *png_user_chunk_ptr, (png_structp,
814 png_unknown_chunkp));
815 #endif
816 #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
817 /* not used anywhere */
818 /* typedef PNG_CALLBACK(void, *png_unknown_chunk_ptr, (png_structp)); */
819 #endif
820
821 #ifdef PNG_SETJMP_SUPPORTED
822 /* This must match the function definition in <setjmp.h>, and the application
823 * must include this before png.h to obtain the definition of jmp_buf. The
824 * function is required to be PNG_NORETURN, but this is not checked. If the
825 * function does return the application will crash via an abort() or similar
826 * system level call.
827 *
828 * If you get a warning here while building the library you may need to make
829 * changes to ensure that pnglibconf.h records the calling convention used by
830 * your compiler. This may be very difficult - try using a different compiler
831 * to build the library!
832 */
833 PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)), typedef);
834 #endif
835
836 /* Transform masks for the high-level interface */
837 #define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */
838 #define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */
839 #define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */
840 #define PNG_TRANSFORM_PACKING 0x0004 /* read and write */
841 #define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */
842 #define PNG_TRANSFORM_EXPAND 0x0010 /* read only */
843 #define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */
844 #define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */
845 #define PNG_TRANSFORM_BGR 0x0080 /* read and write */
846 #define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */
847 #define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */
848 #define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */
849 #define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* write only */
850 /* Added to libpng-1.2.34 */
851 #define PNG_TRANSFORM_STRIP_FILLER_BEFORE PNG_TRANSFORM_STRIP_FILLER
852 #define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */
853 /* Added to libpng-1.4.0 */
854 #define PNG_TRANSFORM_GRAY_TO_RGB 0x2000 /* read only */
855 /* Added to libpng-1.5.4 */
856 #define PNG_TRANSFORM_EXPAND_16 0x4000 /* read only */
857 #if INT_MAX >= 0x8000 /* else this might break */
858 #define PNG_TRANSFORM_SCALE_16 0x8000 /* read only */
859 #endif
860
861 /* Flags for MNG supported features */
862 #define PNG_FLAG_MNG_EMPTY_PLTE 0x01
863 #define PNG_FLAG_MNG_FILTER_64 0x04
864 #define PNG_ALL_MNG_FEATURES 0x05
865
866 /* NOTE: prior to 1.5 these functions had no 'API' style declaration,
867 * this allowed the zlib default functions to be used on Windows
868 * platforms. In 1.5 the zlib default malloc (which just calls malloc and
869 * ignores the first argument) should be completely compatible with the
870 * following.
871 */
872 typedef PNG_CALLBACK(png_voidp, *png_malloc_ptr, (png_structp,
873 png_alloc_size_t));
874 typedef PNG_CALLBACK(void, *png_free_ptr, (png_structp, png_voidp));
875
876 /* Section 4: exported functions
877 * Here are the function definitions most commonly used. This is not
878 * the place to find out how to use libpng. See libpng-manual.txt for the
879 * full explanation, see example.c for the summary. This just provides
880 * a simple one line description of the use of each function.
881 *
882 * The PNG_EXPORT() and PNG_EXPORTA() macros used below are defined in
883 * pngconf.h and in the *.dfn files in the scripts directory.
884 *
885 * PNG_EXPORT(ordinal, type, name, (args));
886 *
887 * ordinal: ordinal that is used while building
888 * *.def files. The ordinal value is only
889 * relevant when preprocessing png.h with
890 * the *.dfn files for building symbol table
891 * entries, and are removed by pngconf.h.
892 * type: return type of the function
893 * name: function name
894 * args: function arguments, with types
895 *
896 * When we wish to append attributes to a function prototype we use
897 * the PNG_EXPORTA() macro instead.
898 *
899 * PNG_EXPORTA(ordinal, type, name, (args), attributes);
900 *
901 * ordinal, type, name, and args: same as in PNG_EXPORT().
902 * attributes: function attributes
903 */
904
905 /* Returns the version number of the library */
906 PNG_EXPORT(1, png_uint_32, png_access_version_number, (void));
907
908 /* Tell lib we have already handled the first <num_bytes> magic bytes.
909 * Handling more than 8 bytes from the beginning of the file is an error.
910 */
911 PNG_EXPORT(2, void, png_set_sig_bytes, (png_structrp png_ptr, int num_bytes));
912
913 /* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
914 * PNG file. Returns zero if the supplied bytes match the 8-byte PNG
915 * signature, and non-zero otherwise. Having num_to_check == 0 or
916 * start > 7 will always fail (ie return non-zero).
917 */
918 PNG_EXPORT(3, int, png_sig_cmp, (png_const_bytep sig, png_size_t start,
919 png_size_t num_to_check));
920
921 /* Simple signature checking function. This is the same as calling
922 * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n).
923 */
924 #define png_check_sig(sig, n) !png_sig_cmp((sig), 0, (n))
925
926 /* Allocate and initialize png_ptr struct for reading, and any other memory. */
927 PNG_EXPORTA(4, png_structp, png_create_read_struct,
928 (png_const_charp user_png_ver, png_voidp error_ptr,
929 png_error_ptr error_fn, png_error_ptr warn_fn),
930 PNG_ALLOCATED);
931
932 /* Allocate and initialize png_ptr struct for writing, and any other memory */
933 PNG_EXPORTA(5, png_structp, png_create_write_struct,
934 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
935 png_error_ptr warn_fn),
936 PNG_ALLOCATED);
937
938 PNG_EXPORT(6, png_size_t, png_get_compression_buffer_size,
939 (png_const_structrp png_ptr));
940
941 PNG_EXPORT(7, void, png_set_compression_buffer_size, (png_structrp png_ptr,
942 png_size_t size));
943
944 /* Moved from pngconf.h in 1.4.0 and modified to ensure setjmp/longjmp
945 * match up.
946 */
947 #ifdef PNG_SETJMP_SUPPORTED
948 /* This function returns the jmp_buf built in to *png_ptr. It must be
949 * supplied with an appropriate 'longjmp' function to use on that jmp_buf
950 * unless the default error function is overridden in which case NULL is
951 * acceptable. The size of the jmp_buf is checked against the actual size
952 * allocated by the library - the call will return NULL on a mismatch
953 * indicating an ABI mismatch.
954 */
955 PNG_EXPORT(8, jmp_buf*, png_set_longjmp_fn, (png_structrp png_ptr,
956 png_longjmp_ptr longjmp_fn, size_t jmp_buf_size));
957 # define png_jmpbuf(png_ptr) \
958 (*png_set_longjmp_fn((png_ptr), longjmp, (sizeof (jmp_buf))))
959 #else
960 # define png_jmpbuf(png_ptr) \
961 (LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP)
962 #endif
963 /* This function should be used by libpng applications in place of
964 * longjmp(png_ptr->jmpbuf, val). If longjmp_fn() has been set, it
965 * will use it; otherwise it will call PNG_ABORT(). This function was
966 * added in libpng-1.5.0.
967 */
968 PNG_EXPORTA(9, void, png_longjmp, (png_const_structrp png_ptr, int val),
969 PNG_NORETURN);
970
971 #ifdef PNG_READ_SUPPORTED
972 /* Reset the compression stream */
973 PNG_EXPORTA(10, int, png_reset_zstream, (png_structrp png_ptr), PNG_DEPRECATED);
974 #endif
975
976 /* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */
977 #ifdef PNG_USER_MEM_SUPPORTED
978 PNG_EXPORTA(11, png_structp, png_create_read_struct_2,
979 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
980 png_error_ptr warn_fn,
981 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn),
982 PNG_ALLOCATED);
983 PNG_EXPORTA(12, png_structp, png_create_write_struct_2,
984 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
985 png_error_ptr warn_fn,
986 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn),
987 PNG_ALLOCATED);
988 #endif
989
990 /* Write the PNG file signature. */
991 PNG_EXPORT(13, void, png_write_sig, (png_structrp png_ptr));
992
993 /* Write a PNG chunk - size, type, (optional) data, CRC. */
994 PNG_EXPORT(14, void, png_write_chunk, (png_structrp png_ptr, png_const_bytep
995 chunk_name, png_const_bytep data, png_size_t length));
996
997 /* Write the start of a PNG chunk - length and chunk name. */
998 PNG_EXPORT(15, void, png_write_chunk_start, (png_structrp png_ptr,
999 png_const_bytep chunk_name, png_uint_32 length));
1000
1001 /* Write the data of a PNG chunk started with png_write_chunk_start(). */
1002 PNG_EXPORT(16, void, png_write_chunk_data, (png_structrp png_ptr,
1003 png_const_bytep data, png_size_t length));
1004
1005 /* Finish a chunk started with png_write_chunk_start() (includes CRC). */
1006 PNG_EXPORT(17, void, png_write_chunk_end, (png_structrp png_ptr));
1007
1008 /* Allocate and initialize the info structure */
1009 PNG_EXPORTA(18, png_infop, png_create_info_struct, (png_const_structrp png_ptr),
1010 PNG_ALLOCATED);
1011
1012 /* DEPRECATED: this function allowed init structures to be created using the
1013 * default allocation method (typically malloc). Use is deprecated in 1.6.0 and
1014 * the API will be removed in the future.
1015 */
1016 PNG_EXPORTA(19, void, png_info_init_3, (png_infopp info_ptr,
1017 png_size_t png_info_struct_size), PNG_DEPRECATED);
1018
1019 /* Writes all the PNG information before the image. */
1020 PNG_EXPORT(20, void, png_write_info_before_PLTE,
1021 (png_structrp png_ptr, png_const_inforp info_ptr));
1022 PNG_EXPORT(21, void, png_write_info,
1023 (png_structrp png_ptr, png_const_inforp info_ptr));
1024
1025 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1026 /* Read the information before the actual image data. */
1027 PNG_EXPORT(22, void, png_read_info,
1028 (png_structrp png_ptr, png_inforp info_ptr));
1029 #endif
1030
1031 #ifdef PNG_TIME_RFC1123_SUPPORTED
1032 /* Convert to a US string format: there is no localization support in this
1033 * routine. The original implementation used a 29 character buffer in
1034 * png_struct, this will be removed in future versions.
1035 */
1036 #if PNG_LIBPNG_VER < 10700
1037 /* To do: remove this from libpng17 (and from libpng17/png.c and pngstruct.h) */
1038 PNG_EXPORTA(23, png_const_charp, png_convert_to_rfc1123, (png_structrp png_ptr,
1039 png_const_timep ptime),PNG_DEPRECATED);
1040 #endif
1041 PNG_EXPORT(241, int, png_convert_to_rfc1123_buffer, (char out[29],
1042 png_const_timep ptime));
1043 #endif
1044
1045 #ifdef PNG_CONVERT_tIME_SUPPORTED
1046 /* Convert from a struct tm to png_time */
1047 PNG_EXPORT(24, void, png_convert_from_struct_tm, (png_timep ptime,
1048 const struct tm * ttime));
1049
1050 /* Convert from time_t to png_time. Uses gmtime() */
1051 PNG_EXPORT(25, void, png_convert_from_time_t, (png_timep ptime, time_t ttime));
1052 #endif /* CONVERT_tIME */
1053
1054 #ifdef PNG_READ_EXPAND_SUPPORTED
1055 /* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
1056 PNG_EXPORT(26, void, png_set_expand, (png_structrp png_ptr));
1057 PNG_EXPORT(27, void, png_set_expand_gray_1_2_4_to_8, (png_structrp png_ptr));
1058 PNG_EXPORT(28, void, png_set_palette_to_rgb, (png_structrp png_ptr));
1059 PNG_EXPORT(29, void, png_set_tRNS_to_alpha, (png_structrp png_ptr));
1060 #endif
1061
1062 #ifdef PNG_READ_EXPAND_16_SUPPORTED
1063 /* Expand to 16-bit channels, forces conversion of palette to RGB and expansion
1064 * of a tRNS chunk if present.
1065 */
1066 PNG_EXPORT(221, void, png_set_expand_16, (png_structrp png_ptr));
1067 #endif
1068
1069 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
1070 /* Use blue, green, red order for pixels. */
1071 PNG_EXPORT(30, void, png_set_bgr, (png_structrp png_ptr));
1072 #endif
1073
1074 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
1075 /* Expand the grayscale to 24-bit RGB if necessary. */
1076 PNG_EXPORT(31, void, png_set_gray_to_rgb, (png_structrp png_ptr));
1077 #endif
1078
1079 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1080 /* Reduce RGB to grayscale. */
1081 #define PNG_ERROR_ACTION_NONE 1
1082 #define PNG_ERROR_ACTION_WARN 2
1083 #define PNG_ERROR_ACTION_ERROR 3
1084 #define PNG_RGB_TO_GRAY_DEFAULT (-1)/*for red/green coefficients*/
1085
1086 PNG_FP_EXPORT(32, void, png_set_rgb_to_gray, (png_structrp png_ptr,
1087 int error_action, double red, double green))
1088 PNG_FIXED_EXPORT(33, void, png_set_rgb_to_gray_fixed, (png_structrp png_ptr,
1089 int error_action, png_fixed_point red, png_fixed_point green))
1090
1091 PNG_EXPORT(34, png_byte, png_get_rgb_to_gray_status, (png_const_structrp
1092 png_ptr));
1093 #endif
1094
1095 #ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED
1096 PNG_EXPORT(35, void, png_build_grayscale_palette, (int bit_depth,
1097 png_colorp palette));
1098 #endif
1099
1100 #ifdef PNG_READ_ALPHA_MODE_SUPPORTED
1101 /* How the alpha channel is interpreted - this affects how the color channels
1102 * of a PNG file are returned to the calling application when an alpha channel,
1103 * or a tRNS chunk in a palette file, is present.
1104 *
1105 * This has no effect on the way pixels are written into a PNG output
1106 * datastream. The color samples in a PNG datastream are never premultiplied
1107 * with the alpha samples.
1108 *
1109 * The default is to return data according to the PNG specification: the alpha
1110 * channel is a linear measure of the contribution of the pixel to the
1111 * corresponding composited pixel, and the color channels are unassociated
1112 * (not premultiplied). The gamma encoded color channels must be scaled
1113 * according to the contribution and to do this it is necessary to undo
1114 * the encoding, scale the color values, perform the composition and reencode
1115 * the values. This is the 'PNG' mode.
1116 *
1117 * The alternative is to 'associate' the alpha with the color information by
1118 * storing color channel values that have been scaled by the alpha.
1119 * image. These are the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' modes
1120 * (the latter being the two common names for associated alpha color channels).
1121 *
1122 * For the 'OPTIMIZED' mode, a pixel is treated as opaque only if the alpha
1123 * value is equal to the maximum value.
1124 *
1125 * The final choice is to gamma encode the alpha channel as well. This is
1126 * broken because, in practice, no implementation that uses this choice
1127 * correctly undoes the encoding before handling alpha composition. Use this
1128 * choice only if other serious errors in the software or hardware you use
1129 * mandate it; the typical serious error is for dark halos to appear around
1130 * opaque areas of the composited PNG image because of arithmetic overflow.
1131 *
1132 * The API function png_set_alpha_mode specifies which of these choices to use
1133 * with an enumerated 'mode' value and the gamma of the required output:
1134 */
1135 #define PNG_ALPHA_PNG 0 /* according to the PNG standard */
1136 #define PNG_ALPHA_STANDARD 1 /* according to Porter/Duff */
1137 #define PNG_ALPHA_ASSOCIATED 1 /* as above; this is the normal practice */
1138 #define PNG_ALPHA_PREMULTIPLIED 1 /* as above */
1139 #define PNG_ALPHA_OPTIMIZED 2 /* 'PNG' for opaque pixels, else 'STANDARD' */
1140 #define PNG_ALPHA_BROKEN 3 /* the alpha channel is gamma encoded */
1141
1142 PNG_FP_EXPORT(227, void, png_set_alpha_mode, (png_structrp png_ptr, int mode,
1143 double output_gamma))
1144 PNG_FIXED_EXPORT(228, void, png_set_alpha_mode_fixed, (png_structrp png_ptr,
1145 int mode, png_fixed_point output_gamma))
1146 #endif
1147
1148 #if defined(PNG_GAMMA_SUPPORTED) || defined(PNG_READ_ALPHA_MODE_SUPPORTED)
1149 /* The output_gamma value is a screen gamma in libpng terminology: it expresses
1150 * how to decode the output values, not how they are encoded.
1151 */
1152 #define PNG_DEFAULT_sRGB -1 /* sRGB gamma and color space */
1153 #define PNG_GAMMA_MAC_18 -2 /* Old Mac '1.8' gamma and color space */
1154 #define PNG_GAMMA_sRGB 220000 /* Television standards--matches sRGB gamma */
1155 #define PNG_GAMMA_LINEAR PNG_FP_1 /* Linear */
1156 #endif
1157
1158 /* The following are examples of calls to png_set_alpha_mode to achieve the
1159 * required overall gamma correction and, where necessary, alpha
1160 * premultiplication.
1161 *
1162 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
1163 * This is the default libpng handling of the alpha channel - it is not
1164 * pre-multiplied into the color components. In addition the call states
1165 * that the output is for a sRGB system and causes all PNG files without gAMA
1166 * chunks to be assumed to be encoded using sRGB.
1167 *
1168 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
1169 * In this case the output is assumed to be something like an sRGB conformant
1170 * display preceeded by a power-law lookup table of power 1.45. This is how
1171 * early Mac systems behaved.
1172 *
1173 * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR);
1174 * This is the classic Jim Blinn approach and will work in academic
1175 * environments where everything is done by the book. It has the shortcoming
1176 * of assuming that input PNG data with no gamma information is linear - this
1177 * is unlikely to be correct unless the PNG files where generated locally.
1178 * Most of the time the output precision will be so low as to show
1179 * significant banding in dark areas of the image.
1180 *
1181 * png_set_expand_16(pp);
1182 * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB);
1183 * This is a somewhat more realistic Jim Blinn inspired approach. PNG files
1184 * are assumed to have the sRGB encoding if not marked with a gamma value and
1185 * the output is always 16 bits per component. This permits accurate scaling
1186 * and processing of the data. If you know that your input PNG files were
1187 * generated locally you might need to replace PNG_DEFAULT_sRGB with the
1188 * correct value for your system.
1189 *
1190 * png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB);
1191 * If you just need to composite the PNG image onto an existing background
1192 * and if you control the code that does this you can use the optimization
1193 * setting. In this case you just copy completely opaque pixels to the
1194 * output. For pixels that are not completely transparent (you just skip
1195 * those) you do the composition math using png_composite or png_composite_16
1196 * below then encode the resultant 8-bit or 16-bit values to match the output
1197 * encoding.
1198 *
1199 * Other cases
1200 * If neither the PNG nor the standard linear encoding work for you because
1201 * of the software or hardware you use then you have a big problem. The PNG
1202 * case will probably result in halos around the image. The linear encoding
1203 * will probably result in a washed out, too bright, image (it's actually too
1204 * contrasty.) Try the ALPHA_OPTIMIZED mode above - this will probably
1205 * substantially reduce the halos. Alternatively try:
1206 *
1207 * png_set_alpha_mode(pp, PNG_ALPHA_BROKEN, PNG_DEFAULT_sRGB);
1208 * This option will also reduce the halos, but there will be slight dark
1209 * halos round the opaque parts of the image where the background is light.
1210 * In the OPTIMIZED mode the halos will be light halos where the background
1211 * is dark. Take your pick - the halos are unavoidable unless you can get
1212 * your hardware/software fixed! (The OPTIMIZED approach is slightly
1213 * faster.)
1214 *
1215 * When the default gamma of PNG files doesn't match the output gamma.
1216 * If you have PNG files with no gamma information png_set_alpha_mode allows
1217 * you to provide a default gamma, but it also sets the ouput gamma to the
1218 * matching value. If you know your PNG files have a gamma that doesn't
1219 * match the output you can take advantage of the fact that
1220 * png_set_alpha_mode always sets the output gamma but only sets the PNG
1221 * default if it is not already set:
1222 *
1223 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
1224 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
1225 * The first call sets both the default and the output gamma values, the
1226 * second call overrides the output gamma without changing the default. This
1227 * is easier than achieving the same effect with png_set_gamma. You must use
1228 * PNG_ALPHA_PNG for the first call - internal checking in png_set_alpha will
1229 * fire if more than one call to png_set_alpha_mode and png_set_background is
1230 * made in the same read operation, however multiple calls with PNG_ALPHA_PNG
1231 * are ignored.
1232 */
1233
1234 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
1235 PNG_EXPORT(36, void, png_set_strip_alpha, (png_structrp png_ptr));
1236 #endif
1237
1238 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
1239 defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
1240 PNG_EXPORT(37, void, png_set_swap_alpha, (png_structrp png_ptr));
1241 #endif
1242
1243 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
1244 defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
1245 PNG_EXPORT(38, void, png_set_invert_alpha, (png_structrp png_ptr));
1246 #endif
1247
1248 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
1249 /* Add a filler byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */
1250 PNG_EXPORT(39, void, png_set_filler, (png_structrp png_ptr, png_uint_32 filler,
1251 int flags));
1252 /* The values of the PNG_FILLER_ defines should NOT be changed */
1253 # define PNG_FILLER_BEFORE 0
1254 # define PNG_FILLER_AFTER 1
1255 /* Add an alpha byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */
1256 PNG_EXPORT(40, void, png_set_add_alpha, (png_structrp png_ptr,
1257 png_uint_32 filler, int flags));
1258 #endif /* READ_FILLER || WRITE_FILLER */
1259
1260 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
1261 /* Swap bytes in 16-bit depth files. */
1262 PNG_EXPORT(41, void, png_set_swap, (png_structrp png_ptr));
1263 #endif
1264
1265 #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
1266 /* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
1267 PNG_EXPORT(42, void, png_set_packing, (png_structrp png_ptr));
1268 #endif
1269
1270 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
1271 defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1272 /* Swap packing order of pixels in bytes. */
1273 PNG_EXPORT(43, void, png_set_packswap, (png_structrp png_ptr));
1274 #endif
1275
1276 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
1277 /* Converts files to legal bit depths. */
1278 PNG_EXPORT(44, void, png_set_shift, (png_structrp png_ptr, png_const_color_8p
1279 true_bits));
1280 #endif
1281
1282 #if defined(PNG_READ_INTERLACING_SUPPORTED) || \
1283 defined(PNG_WRITE_INTERLACING_SUPPORTED)
1284 /* Have the code handle the interlacing. Returns the number of passes.
1285 * MUST be called before png_read_update_info or png_start_read_image,
1286 * otherwise it will not have the desired effect. Note that it is still
1287 * necessary to call png_read_row or png_read_rows png_get_image_height
1288 * times for each pass.
1289 */
1290 PNG_EXPORT(45, int, png_set_interlace_handling, (png_structrp png_ptr));
1291 #endif
1292
1293 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
1294 /* Invert monochrome files */
1295 PNG_EXPORT(46, void, png_set_invert_mono, (png_structrp png_ptr));
1296 #endif
1297
1298 #ifdef PNG_READ_BACKGROUND_SUPPORTED
1299 /* Handle alpha and tRNS by replacing with a background color. Prior to
1300 * libpng-1.5.4 this API must not be called before the PNG file header has been
1301 * read. Doing so will result in unexpected behavior and possible warnings or
1302 * errors if the PNG file contains a bKGD chunk.
1303 */
1304 PNG_FP_EXPORT(47, void, png_set_background, (png_structrp png_ptr,
1305 png_const_color_16p background_color, int background_gamma_code,
1306 int need_expand, double background_gamma))
1307 PNG_FIXED_EXPORT(215, void, png_set_background_fixed, (png_structrp png_ptr,
1308 png_const_color_16p background_color, int background_gamma_code,
1309 int need_expand, png_fixed_point background_gamma))
1310 #endif
1311 #ifdef PNG_READ_BACKGROUND_SUPPORTED
1312 # define PNG_BACKGROUND_GAMMA_UNKNOWN 0
1313 # define PNG_BACKGROUND_GAMMA_SCREEN 1
1314 # define PNG_BACKGROUND_GAMMA_FILE 2
1315 # define PNG_BACKGROUND_GAMMA_UNIQUE 3
1316 #endif
1317
1318 #ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
1319 /* Scale a 16-bit depth file down to 8-bit, accurately. */
1320 PNG_EXPORT(229, void, png_set_scale_16, (png_structrp png_ptr));
1321 #endif
1322
1323 #ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
1324 #define PNG_READ_16_TO_8 SUPPORTED /* Name prior to 1.5.4 */
1325 /* Strip the second byte of information from a 16-bit depth file. */
1326 PNG_EXPORT(48, void, png_set_strip_16, (png_structrp png_ptr));
1327 #endif
1328
1329 #ifdef PNG_READ_QUANTIZE_SUPPORTED
1330 /* Turn on quantizing, and reduce the palette to the number of colors
1331 * available.
1332 */
1333 PNG_EXPORT(49, void, png_set_quantize, (png_structrp png_ptr,
1334 png_colorp palette, int num_palette, int maximum_colors,
1335 png_const_uint_16p histogram, int full_quantize));
1336 #endif
1337
1338 #ifdef PNG_READ_GAMMA_SUPPORTED
1339 /* The threshold on gamma processing is configurable but hard-wired into the
1340 * library. The following is the floating point variant.
1341 */
1342 #define PNG_GAMMA_THRESHOLD (PNG_GAMMA_THRESHOLD_FIXED*.00001)
1343
1344 /* Handle gamma correction. Screen_gamma=(display_exponent).
1345 * NOTE: this API simply sets the screen and file gamma values. It will
1346 * therefore override the value for gamma in a PNG file if it is called after
1347 * the file header has been read - use with care - call before reading the PNG
1348 * file for best results!
1349 *
1350 * These routines accept the same gamma values as png_set_alpha_mode (described
1351 * above). The PNG_GAMMA_ defines and PNG_DEFAULT_sRGB can be passed to either
1352 * API (floating point or fixed.) Notice, however, that the 'file_gamma' value
1353 * is the inverse of a 'screen gamma' value.
1354 */
1355 PNG_FP_EXPORT(50, void, png_set_gamma, (png_structrp png_ptr,
1356 double screen_gamma, double override_file_gamma))
1357 PNG_FIXED_EXPORT(208, void, png_set_gamma_fixed, (png_structrp png_ptr,
1358 png_fixed_point screen_gamma, png_fixed_point override_file_gamma))
1359 #endif
1360
1361 #ifdef PNG_WRITE_FLUSH_SUPPORTED
1362 /* Set how many lines between output flushes - 0 for no flushing */
1363 PNG_EXPORT(51, void, png_set_flush, (png_structrp png_ptr, int nrows));
1364 /* Flush the current PNG output buffer */
1365 PNG_EXPORT(52, void, png_write_flush, (png_structrp png_ptr));
1366 #endif
1367
1368 /* Optional update palette with requested transformations */
1369 PNG_EXPORT(53, void, png_start_read_image, (png_structrp png_ptr));
1370
1371 /* Optional call to update the users info structure */
1372 PNG_EXPORT(54, void, png_read_update_info, (png_structrp png_ptr,
1373 png_inforp info_ptr));
1374
1375 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1376 /* Read one or more rows of image data. */
1377 PNG_EXPORT(55, void, png_read_rows, (png_structrp png_ptr, png_bytepp row,
1378 png_bytepp display_row, png_uint_32 num_rows));
1379 #endif
1380
1381 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1382 /* Read a row of data. */
1383 PNG_EXPORT(56, void, png_read_row, (png_structrp png_ptr, png_bytep row,
1384 png_bytep display_row));
1385 #endif
1386
1387 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1388 /* Read the whole image into memory at once. */
1389 PNG_EXPORT(57, void, png_read_image, (png_structrp png_ptr, png_bytepp image));
1390 #endif
1391
1392 /* Write a row of image data */
1393 PNG_EXPORT(58, void, png_write_row, (png_structrp png_ptr,
1394 png_const_bytep row));
1395
1396 /* Write a few rows of image data: (*row) is not written; however, the type
1397 * is declared as writeable to maintain compatibility with previous versions
1398 * of libpng and to allow the 'display_row' array from read_rows to be passed
1399 * unchanged to write_rows.
1400 */
1401 PNG_EXPORT(59, void, png_write_rows, (png_structrp png_ptr, png_bytepp row,
1402 png_uint_32 num_rows));
1403
1404 /* Write the image data */
1405 PNG_EXPORT(60, void, png_write_image, (png_structrp png_ptr, png_bytepp image));
1406
1407 /* Write the end of the PNG file. */
1408 PNG_EXPORT(61, void, png_write_end, (png_structrp png_ptr,
1409 png_inforp info_ptr));
1410
1411 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1412 /* Read the end of the PNG file. */
1413 PNG_EXPORT(62, void, png_read_end, (png_structrp png_ptr, png_inforp info_ptr));
1414 #endif
1415
1416 /* Free any memory associated with the png_info_struct */
1417 PNG_EXPORT(63, void, png_destroy_info_struct, (png_const_structrp png_ptr,
1418 png_infopp info_ptr_ptr));
1419
1420 /* Free any memory associated with the png_struct and the png_info_structs */
1421 PNG_EXPORT(64, void, png_destroy_read_struct, (png_structpp png_ptr_ptr,
1422 png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr));
1423
1424 /* Free any memory associated with the png_struct and the png_info_structs */
1425 PNG_EXPORT(65, void, png_destroy_write_struct, (png_structpp png_ptr_ptr,
1426 png_infopp info_ptr_ptr));
1427
1428 /* Set the libpng method of handling chunk CRC errors */
1429 PNG_EXPORT(66, void, png_set_crc_action, (png_structrp png_ptr, int crit_action,
1430 int ancil_action));
1431
1432 /* Values for png_set_crc_action() say how to handle CRC errors in
1433 * ancillary and critical chunks, and whether to use the data contained
1434 * therein. Note that it is impossible to "discard" data in a critical
1435 * chunk. For versions prior to 0.90, the action was always error/quit,
1436 * whereas in version 0.90 and later, the action for CRC errors in ancillary
1437 * chunks is warn/discard. These values should NOT be changed.
1438 *
1439 * value action:critical action:ancillary
1440 */
1441 #define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */
1442 #define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */
1443 #define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */
1444 #define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */
1445 #define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */
1446 #define PNG_CRC_NO_CHANGE 5 /* use current value use current value */
1447
1448 #ifdef PNG_WRITE_SUPPORTED
1449 /* These functions give the user control over the scan-line filtering in
1450 * libpng and the compression methods used by zlib. These functions are
1451 * mainly useful for testing, as the defaults should work with most users.
1452 * Those users who are tight on memory or want faster performance at the
1453 * expense of compression can modify them. See the compression library
1454 * header file (zlib.h) for an explination of the compression functions.
1455 */
1456
1457 /* Set the filtering method(s) used by libpng. Currently, the only valid
1458 * value for "method" is 0.
1459 */
1460 PNG_EXPORT(67, void, png_set_filter, (png_structrp png_ptr, int method,
1461 int filters));
1462 #endif /* WRITE */
1463
1464 /* Flags for png_set_filter() to say which filters to use. The flags
1465 * are chosen so that they don't conflict with real filter types
1466 * below, in case they are supplied instead of the #defined constants.
1467 * These values should NOT be changed.
1468 */
1469 #define PNG_NO_FILTERS 0x00
1470 #define PNG_FILTER_NONE 0x08
1471 #define PNG_FILTER_SUB 0x10
1472 #define PNG_FILTER_UP 0x20
1473 #define PNG_FILTER_AVG 0x40
1474 #define PNG_FILTER_PAETH 0x80
1475 #define PNG_ALL_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP | \
1476 PNG_FILTER_AVG | PNG_FILTER_PAETH)
1477
1478 /* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
1479 * These defines should NOT be changed.
1480 */
1481 #define PNG_FILTER_VALUE_NONE 0
1482 #define PNG_FILTER_VALUE_SUB 1
1483 #define PNG_FILTER_VALUE_UP 2
1484 #define PNG_FILTER_VALUE_AVG 3
1485 #define PNG_FILTER_VALUE_PAETH 4
1486 #define PNG_FILTER_VALUE_LAST 5
1487
1488 #ifdef PNG_WRITE_SUPPORTED
1489 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* DEPRECATED */
1490 PNG_FP_EXPORT(68, void, png_set_filter_heuristics, (png_structrp png_ptr,
1491 int heuristic_method, int num_weights, png_const_doublep filter_weights,
1492 png_const_doublep filter_costs))
1493 PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed,
1494 (png_structrp png_ptr, int heuristic_method, int num_weights,
1495 png_const_fixed_point_p filter_weights,
1496 png_const_fixed_point_p filter_costs))
1497 #endif /* WRITE_WEIGHTED_FILTER */
1498
1499 /* The following are no longer used and will be removed from libpng-1.7: */
1500 #define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */
1501 #define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */
1502 #define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */
1503 #define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */
1504
1505 /* Set the library compression level. Currently, valid values range from
1506 * 0 - 9, corresponding directly to the zlib compression levels 0 - 9
1507 * (0 - no compression, 9 - "maximal" compression). Note that tests have
1508 * shown that zlib compression levels 3-6 usually perform as well as level 9
1509 * for PNG images, and do considerably fewer caclulations. In the future,
1510 * these values may not correspond directly to the zlib compression levels.
1511 */
1512 #ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED
1513 PNG_EXPORT(69, void, png_set_compression_level, (png_structrp png_ptr,
1514 int level));
1515
1516 PNG_EXPORT(70, void, png_set_compression_mem_level, (png_structrp png_ptr,
1517 int mem_level));
1518
1519 PNG_EXPORT(71, void, png_set_compression_strategy, (png_structrp png_ptr,
1520 int strategy));
1521
1522 /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
1523 * smaller value of window_bits if it can do so safely.
1524 */
1525 PNG_EXPORT(72, void, png_set_compression_window_bits, (png_structrp png_ptr,
1526 int window_bits));
1527
1528 PNG_EXPORT(73, void, png_set_compression_method, (png_structrp png_ptr,
1529 int method));
1530 #endif /* WRITE_CUSTOMIZE_COMPRESSION */
1531
1532 #ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
1533 /* Also set zlib parameters for compressing non-IDAT chunks */
1534 PNG_EXPORT(222, void, png_set_text_compression_level, (png_structrp png_ptr,
1535 int level));
1536
1537 PNG_EXPORT(223, void, png_set_text_compression_mem_level, (png_structrp png_ptr,
1538 int mem_level));
1539
1540 PNG_EXPORT(224, void, png_set_text_compression_strategy, (png_structrp png_ptr,
1541 int strategy));
1542
1543 /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
1544 * smaller value of window_bits if it can do so safely.
1545 */
1546 PNG_EXPORT(225, void, png_set_text_compression_window_bits,
1547 (png_structrp png_ptr, int window_bits));
1548
1549 PNG_EXPORT(226, void, png_set_text_compression_method, (png_structrp png_ptr,
1550 int method));
1551 #endif /* WRITE_CUSTOMIZE_ZTXT_COMPRESSION */
1552 #endif /* WRITE */
1553
1554 /* These next functions are called for input/output, memory, and error
1555 * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c,
1556 * and call standard C I/O routines such as fread(), fwrite(), and
1557 * fprintf(). These functions can be made to use other I/O routines
1558 * at run time for those applications that need to handle I/O in a
1559 * different manner by calling png_set_???_fn(). See libpng-manual.txt for
1560 * more information.
1561 */
1562
1563 #ifdef PNG_STDIO_SUPPORTED
1564 /* Initialize the input/output for the PNG file to the default functions. */
1565 PNG_EXPORT(74, void, png_init_io, (png_structrp png_ptr, png_FILE_p fp));
1566 #endif
1567
1568 /* Replace the (error and abort), and warning functions with user
1569 * supplied functions. If no messages are to be printed you must still
1570 * write and use replacement functions. The replacement error_fn should
1571 * still do a longjmp to the last setjmp location if you are using this
1572 * method of error handling. If error_fn or warning_fn is NULL, the
1573 * default function will be used.
1574 */
1575
1576 PNG_EXPORT(75, void, png_set_error_fn, (png_structrp png_ptr,
1577 png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn));
1578
1579 /* Return the user pointer associated with the error functions */
1580 PNG_EXPORT(76, png_voidp, png_get_error_ptr, (png_const_structrp png_ptr));
1581
1582 /* Replace the default data output functions with a user supplied one(s).
1583 * If buffered output is not used, then output_flush_fn can be set to NULL.
1584 * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time
1585 * output_flush_fn will be ignored (and thus can be NULL).
1586 * It is probably a mistake to use NULL for output_flush_fn if
1587 * write_data_fn is not also NULL unless you have built libpng with
1588 * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's
1589 * default flush function, which uses the standard *FILE structure, will
1590 * be used.
1591 */
1592 PNG_EXPORT(77, void, png_set_write_fn, (png_structrp png_ptr, png_voidp io_ptr,
1593 png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn));
1594
1595 /* Replace the default data input function with a user supplied one. */
1596 PNG_EXPORT(78, void, png_set_read_fn, (png_structrp png_ptr, png_voidp io_ptr,
1597 png_rw_ptr read_data_fn));
1598
1599 /* Return the user pointer associated with the I/O functions */
1600 PNG_EXPORT(79, png_voidp, png_get_io_ptr, (png_const_structrp png_ptr));
1601
1602 PNG_EXPORT(80, void, png_set_read_status_fn, (png_structrp png_ptr,
1603 png_read_status_ptr read_row_fn));
1604
1605 PNG_EXPORT(81, void, png_set_write_status_fn, (png_structrp png_ptr,
1606 png_write_status_ptr write_row_fn));
1607
1608 #ifdef PNG_USER_MEM_SUPPORTED
1609 /* Replace the default memory allocation functions with user supplied one(s). */
1610 PNG_EXPORT(82, void, png_set_mem_fn, (png_structrp png_ptr, png_voidp mem_ptr,
1611 png_malloc_ptr malloc_fn, png_free_ptr free_fn));
1612 /* Return the user pointer associated with the memory functions */
1613 PNG_EXPORT(83, png_voidp, png_get_mem_ptr, (png_const_structrp png_ptr));
1614 #endif
1615
1616 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
1617 PNG_EXPORT(84, void, png_set_read_user_transform_fn, (png_structrp png_ptr,
1618 png_user_transform_ptr read_user_transform_fn));
1619 #endif
1620
1621 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
1622 PNG_EXPORT(85, void, png_set_write_user_transform_fn, (png_structrp png_ptr,
1623 png_user_transform_ptr write_user_transform_fn));
1624 #endif
1625
1626 #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
1627 PNG_EXPORT(86, void, png_set_user_transform_info, (png_structrp png_ptr,
1628 png_voidp user_transform_ptr, int user_transform_depth,
1629 int user_transform_channels));
1630 /* Return the user pointer associated with the user transform functions */
1631 PNG_EXPORT(87, png_voidp, png_get_user_transform_ptr,
1632 (png_const_structrp png_ptr));
1633 #endif
1634
1635 #ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED
1636 /* Return information about the row currently being processed. Note that these
1637 * APIs do not fail but will return unexpected results if called outside a user
1638 * transform callback. Also note that when transforming an interlaced image the
1639 * row number is the row number within the sub-image of the interlace pass, so
1640 * the value will increase to the height of the sub-image (not the full image)
1641 * then reset to 0 for the next pass.
1642 *
1643 * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
1644 * find the output pixel (x,y) given an interlaced sub-image pixel
1645 * (row,col,pass). (See below for these macros.)
1646 */
1647 PNG_EXPORT(217, png_uint_32, png_get_current_row_number, (png_const_structrp));
1648 PNG_EXPORT(218, png_byte, png_get_current_pass_number, (png_const_structrp));
1649 #endif
1650
1651 #ifdef PNG_READ_USER_CHUNKS_SUPPORTED
1652 /* This callback is called only for *unknown* chunks. If
1653 * PNG_HANDLE_AS_UNKNOWN_SUPPORTED is set then it is possible to set known
1654 * chunks to be treated as unknown, however in this case the callback must do
1655 * any processing required by the chunk (e.g. by calling the appropriate
1656 * png_set_ APIs.)
1657 *
1658 * There is no write support - on write, by default, all the chunks in the
1659 * 'unknown' list are written in the specified position.
1660 *
1661 * The integer return from the callback function is interpreted thus:
1662 *
1663 * negative: An error occurred; png_chunk_error will be called.
1664 * zero: The chunk was not handled, the chunk will be saved. A critical
1665 * chunk will cause an error at this point unless it is to be saved.
1666 * positive: The chunk was handled, libpng will ignore/discard it.
1667 *
1668 * See "INTERACTION WTIH USER CHUNK CALLBACKS" below for important notes about
1669 * how this behavior will change in libpng 1.7
1670 */
1671 PNG_EXPORT(88, void, png_set_read_user_chunk_fn, (png_structrp png_ptr,
1672 png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));
1673 #endif
1674
1675 #ifdef PNG_USER_CHUNKS_SUPPORTED
1676 PNG_EXPORT(89, png_voidp, png_get_user_chunk_ptr, (png_const_structrp png_ptr));
1677 #endif
1678
1679 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1680 /* Sets the function callbacks for the push reader, and a pointer to a
1681 * user-defined structure available to the callback functions.
1682 */
1683 PNG_EXPORT(90, void, png_set_progressive_read_fn, (png_structrp png_ptr,
1684 png_voidp progressive_ptr, png_progressive_info_ptr info_fn,
1685 png_progressive_row_ptr row_fn, png_progressive_end_ptr end_fn));
1686
1687 /* Returns the user pointer associated with the push read functions */
1688 PNG_EXPORT(91, png_voidp, png_get_progressive_ptr,
1689 (png_const_structrp png_ptr));
1690
1691 /* Function to be called when data becomes available */
1692 PNG_EXPORT(92, void, png_process_data, (png_structrp png_ptr,
1693 png_inforp info_ptr, png_bytep buffer, png_size_t buffer_size));
1694
1695 /* A function which may be called *only* within png_process_data to stop the
1696 * processing of any more data. The function returns the number of bytes
1697 * remaining, excluding any that libpng has cached internally. A subsequent
1698 * call to png_process_data must supply these bytes again. If the argument
1699 * 'save' is set to true the routine will first save all the pending data and
1700 * will always return 0.
1701 */
1702 PNG_EXPORT(219, png_size_t, png_process_data_pause, (png_structrp, int save));
1703
1704 /* A function which may be called *only* outside (after) a call to
1705 * png_process_data. It returns the number of bytes of data to skip in the
1706 * input. Normally it will return 0, but if it returns a non-zero value the
1707 * application must skip than number of bytes of input data and pass the
1708 * following data to the next call to png_process_data.
1709 */
1710 PNG_EXPORT(220, png_uint_32, png_process_data_skip, (png_structrp));
1711
1712 /* Function that combines rows. 'new_row' is a flag that should come from
1713 * the callback and be non-NULL if anything needs to be done; the library
1714 * stores its own version of the new data internally and ignores the passed
1715 * in value.
1716 */
1717 PNG_EXPORT(93, void, png_progressive_combine_row, (png_const_structrp png_ptr,
1718 png_bytep old_row, png_const_bytep new_row));
1719 #endif /* PROGRESSIVE_READ */
1720
1721 PNG_EXPORTA(94, png_voidp, png_malloc, (png_const_structrp png_ptr,
1722 png_alloc_size_t size), PNG_ALLOCATED);
1723 /* Added at libpng version 1.4.0 */
1724 PNG_EXPORTA(95, png_voidp, png_calloc, (png_const_structrp png_ptr,
1725 png_alloc_size_t size), PNG_ALLOCATED);
1726
1727 /* Added at libpng version 1.2.4 */
1728 PNG_EXPORTA(96, png_voidp, png_malloc_warn, (png_const_structrp png_ptr,
1729 png_alloc_size_t size), PNG_ALLOCATED);
1730
1731 /* Frees a pointer allocated by png_malloc() */
1732 PNG_EXPORT(97, void, png_free, (png_const_structrp png_ptr, png_voidp ptr));
1733
1734 /* Free data that was allocated internally */
1735 PNG_EXPORT(98, void, png_free_data, (png_const_structrp png_ptr,
1736 png_inforp info_ptr, png_uint_32 free_me, int num));
1737
1738 /* Reassign responsibility for freeing existing data, whether allocated
1739 * by libpng or by the application; this works on the png_info structure passed
1740 * in, it does not change the state for other png_info structures.
1741 *
1742 * It is unlikely that this function works correctly as of 1.6.0 and using it
1743 * may result either in memory leaks or double free of allocated data.
1744 */
1745 PNG_EXPORT(99, void, png_data_freer, (png_const_structrp png_ptr,
1746 png_inforp info_ptr, int freer, png_uint_32 mask));
1747
1748 /* Assignments for png_data_freer */
1749 #define PNG_DESTROY_WILL_FREE_DATA 1
1750 #define PNG_SET_WILL_FREE_DATA 1
1751 #define PNG_USER_WILL_FREE_DATA 2
1752 /* Flags for png_ptr->free_me and info_ptr->free_me */
1753 #define PNG_FREE_HIST 0x0008
1754 #define PNG_FREE_ICCP 0x0010
1755 #define PNG_FREE_SPLT 0x0020
1756 #define PNG_FREE_ROWS 0x0040
1757 #define PNG_FREE_PCAL 0x0080
1758 #define PNG_FREE_SCAL 0x0100
1759 #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
1760 # define PNG_FREE_UNKN 0x0200
1761 #endif
1762 /* PNG_FREE_LIST 0x0400 removed in 1.6.0 because it is ignored */
1763 #define PNG_FREE_PLTE 0x1000
1764 #define PNG_FREE_TRNS 0x2000
1765 #define PNG_FREE_TEXT 0x4000
1766 #define PNG_FREE_ALL 0x7fff
1767 #define PNG_FREE_MUL 0x4220 /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */
1768
1769 #ifdef PNG_USER_MEM_SUPPORTED
1770 PNG_EXPORTA(100, png_voidp, png_malloc_default, (png_const_structrp png_ptr,
1771 png_alloc_size_t size), PNG_ALLOCATED PNG_DEPRECATED);
1772 PNG_EXPORTA(101, void, png_free_default, (png_const_structrp png_ptr,
1773 png_voidp ptr), PNG_DEPRECATED);
1774 #endif
1775
1776 #ifdef PNG_ERROR_TEXT_SUPPORTED
1777 /* Fatal error in PNG image of libpng - can't continue */
1778 PNG_EXPORTA(102, void, png_error, (png_const_structrp png_ptr,
1779 png_const_charp error_message), PNG_NORETURN);
1780
1781 /* The same, but the chunk name is prepended to the error string. */
1782 PNG_EXPORTA(103, void, png_chunk_error, (png_const_structrp png_ptr,
1783 png_const_charp error_message), PNG_NORETURN);
1784
1785 #else
1786 /* Fatal error in PNG image of libpng - can't continue */
1787 PNG_EXPORTA(104, void, png_err, (png_const_structrp png_ptr), PNG_NORETURN);
1788 # define png_error(s1,s2) png_err(s1)
1789 # define png_chunk_error(s1,s2) png_err(s1)
1790 #endif
1791
1792 #ifdef PNG_WARNINGS_SUPPORTED
1793 /* Non-fatal error in libpng. Can continue, but may have a problem. */
1794 PNG_EXPORT(105, void, png_warning, (png_const_structrp png_ptr,
1795 png_const_charp warning_message));
1796
1797 /* Non-fatal error in libpng, chunk name is prepended to message. */
1798 PNG_EXPORT(106, void, png_chunk_warning, (png_const_structrp png_ptr,
1799 png_const_charp warning_message));
1800 #else
1801 # define png_warning(s1,s2) ((void)(s1))
1802 # define png_chunk_warning(s1,s2) ((void)(s1))
1803 #endif
1804
1805 #ifdef PNG_BENIGN_ERRORS_SUPPORTED
1806 /* Benign error in libpng. Can continue, but may have a problem.
1807 * User can choose whether to handle as a fatal error or as a warning. */
1808 PNG_EXPORT(107, void, png_benign_error, (png_const_structrp png_ptr,
1809 png_const_charp warning_message));
1810
1811 #ifdef PNG_READ_SUPPORTED
1812 /* Same, chunk name is prepended to message (only during read) */
1813 PNG_EXPORT(108, void, png_chunk_benign_error, (png_const_structrp png_ptr,
1814 png_const_charp warning_message));
1815 #endif
1816
1817 PNG_EXPORT(109, void, png_set_benign_errors,
1818 (png_structrp png_ptr, int allowed));
1819 #else
1820 # ifdef PNG_ALLOW_BENIGN_ERRORS
1821 # define png_benign_error png_warning
1822 # define png_chunk_benign_error png_chunk_warning
1823 # else
1824 # define png_benign_error png_error
1825 # define png_chunk_benign_error png_chunk_error
1826 # endif
1827 #endif
1828
1829 /* The png_set_<chunk> functions are for storing values in the png_info_struct.
1830 * Similarly, the png_get_<chunk> calls are used to read values from the
1831 * png_info_struct, either storing the parameters in the passed variables, or
1832 * setting pointers into the png_info_struct where the data is stored. The
1833 * png_get_<chunk> functions return a non-zero value if the data was available
1834 * in info_ptr, or return zero and do not change any of the parameters if the
1835 * data was not available.
1836 *
1837 * These functions should be used instead of directly accessing png_info
1838 * to avoid problems with future changes in the size and internal layout of
1839 * png_info_struct.
1840 */
1841 /* Returns "flag" if chunk data is valid in info_ptr. */
1842 PNG_EXPORT(110, png_uint_32, png_get_valid, (png_const_structrp png_ptr,
1843 png_const_inforp info_ptr, png_uint_32 flag));
1844
1845 /* Returns number of bytes needed to hold a transformed row. */
1846 PNG_EXPORT(111, png_size_t, png_get_rowbytes, (png_const_structrp png_ptr,
1847 png_const_inforp info_ptr));
1848
1849 #ifdef PNG_INFO_IMAGE_SUPPORTED
1850 /* Returns row_pointers, which is an array of pointers to scanlines that was
1851 * returned from png_read_png().
1852 */
1853 PNG_EXPORT(112, png_bytepp, png_get_rows, (png_const_structrp png_ptr,
1854 png_const_inforp info_ptr));
1855
1856 /* Set row_pointers, which is an array of pointers to scanlines for use
1857 * by png_write_png().
1858 */
1859 PNG_EXPORT(113, void, png_set_rows, (png_const_structrp png_ptr,
1860 png_inforp info_ptr, png_bytepp row_pointers));
1861 #endif
1862
1863 /* Returns number of color channels in image. */
1864 PNG_EXPORT(114, png_byte, png_get_channels, (png_const_structrp png_ptr,
1865 png_const_inforp info_ptr));
1866
1867 #ifdef PNG_EASY_ACCESS_SUPPORTED
1868 /* Returns image width in pixels. */
1869 PNG_EXPORT(115, png_uint_32, png_get_image_width, (png_const_structrp png_ptr,
1870 png_const_inforp info_ptr));
1871
1872 /* Returns image height in pixels. */
1873 PNG_EXPORT(116, png_uint_32, png_get_image_height, (png_const_structrp png_ptr,
1874 png_const_inforp info_ptr));
1875
1876 /* Returns image bit_depth. */
1877 PNG_EXPORT(117, png_byte, png_get_bit_depth, (png_const_structrp png_ptr,
1878 png_const_inforp info_ptr));
1879
1880 /* Returns image color_type. */
1881 PNG_EXPORT(118, png_byte, png_get_color_type, (png_const_structrp png_ptr,
1882 png_const_inforp info_ptr));
1883
1884 /* Returns image filter_type. */
1885 PNG_EXPORT(119, png_byte, png_get_filter_type, (png_const_structrp png_ptr,
1886 png_const_inforp info_ptr));
1887
1888 /* Returns image interlace_type. */
1889 PNG_EXPORT(120, png_byte, png_get_interlace_type, (png_const_structrp png_ptr,
1890 png_const_inforp info_ptr));
1891
1892 /* Returns image compression_type. */
1893 PNG_EXPORT(121, png_byte, png_get_compression_type, (png_const_structrp png_ptr,
1894 png_const_inforp info_ptr));
1895
1896 /* Returns image resolution in pixels per meter, from pHYs chunk data. */
1897 PNG_EXPORT(122, png_uint_32, png_get_pixels_per_meter,
1898 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1899 PNG_EXPORT(123, png_uint_32, png_get_x_pixels_per_meter,
1900 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1901 PNG_EXPORT(124, png_uint_32, png_get_y_pixels_per_meter,
1902 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1903
1904 /* Returns pixel aspect ratio, computed from pHYs chunk data. */
1905 PNG_FP_EXPORT(125, float, png_get_pixel_aspect_ratio,
1906 (png_const_structrp png_ptr, png_const_inforp info_ptr))
1907 PNG_FIXED_EXPORT(210, png_fixed_point, png_get_pixel_aspect_ratio_fixed,
1908 (png_const_structrp png_ptr, png_const_inforp info_ptr))
1909
1910 /* Returns image x, y offset in pixels or microns, from oFFs chunk data. */
1911 PNG_EXPORT(126, png_int_32, png_get_x_offset_pixels,
1912 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1913 PNG_EXPORT(127, png_int_32, png_get_y_offset_pixels,
1914 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1915 PNG_EXPORT(128, png_int_32, png_get_x_offset_microns,
1916 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1917 PNG_EXPORT(129, png_int_32, png_get_y_offset_microns,
1918 (png_const_structrp png_ptr, png_const_inforp info_ptr));
1919
1920 #endif /* EASY_ACCESS */
1921
1922 #ifdef PNG_READ_SUPPORTED
1923 /* Returns pointer to signature string read from PNG header */
1924 PNG_EXPORT(130, png_const_bytep, png_get_signature, (png_const_structrp png_ptr,
1925 png_const_inforp info_ptr));
1926 #endif
1927
1928 #ifdef PNG_bKGD_SUPPORTED
1929 PNG_EXPORT(131, png_uint_32, png_get_bKGD, (png_const_structrp png_ptr,
1930 png_inforp info_ptr, png_color_16p *background));
1931 #endif
1932
1933 #ifdef PNG_bKGD_SUPPORTED
1934 PNG_EXPORT(132, void, png_set_bKGD, (png_const_structrp png_ptr,
1935 png_inforp info_ptr, png_const_color_16p background));
1936 #endif
1937
1938 #ifdef PNG_cHRM_SUPPORTED
1939 PNG_FP_EXPORT(133, png_uint_32, png_get_cHRM, (png_const_structrp png_ptr,
1940 png_const_inforp info_ptr, double *white_x, double *white_y, double *red_x,
1941 double *red_y, double *green_x, double *green_y, double *blue_x,
1942 double *blue_y))
1943 PNG_FP_EXPORT(230, png_uint_32, png_get_cHRM_XYZ, (png_const_structrp png_ptr,
1944 png_const_inforp info_ptr, double *red_X, double *red_Y, double *red_Z,
1945 double *green_X, double *green_Y, double *green_Z, double *blue_X,
1946 double *blue_Y, double *blue_Z))
1947 PNG_FIXED_EXPORT(134, png_uint_32, png_get_cHRM_fixed,
1948 (png_const_structrp png_ptr, png_const_inforp info_ptr,
1949 png_fixed_point *int_white_x, png_fixed_point *int_white_y,
1950 png_fixed_point *int_red_x, png_fixed_point *int_red_y,
1951 png_fixed_point *int_green_x, png_fixed_point *int_green_y,
1952 png_fixed_point *int_blue_x, png_fixed_point *int_blue_y))
1953 PNG_FIXED_EXPORT(231, png_uint_32, png_get_cHRM_XYZ_fixed,
1954 (png_const_structrp png_ptr, png_const_inforp info_ptr,
1955 png_fixed_point *int_red_X, png_fixed_point *int_red_Y,
1956 png_fixed_point *int_red_Z, png_fixed_point *int_green_X,
1957 png_fixed_point *int_green_Y, png_fixed_point *int_green_Z,
1958 png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y,
1959 png_fixed_point *int_blue_Z))
1960 #endif
1961
1962 #ifdef PNG_cHRM_SUPPORTED
1963 PNG_FP_EXPORT(135, void, png_set_cHRM, (png_const_structrp png_ptr,
1964 png_inforp info_ptr,
1965 double white_x, double white_y, double red_x, double red_y, double green_x,
1966 double green_y, double blue_x, double blue_y))
1967 PNG_FP_EXPORT(232, void, png_set_cHRM_XYZ, (png_const_structrp png_ptr,
1968 png_inforp info_ptr, double red_X, double red_Y, double red_Z,
1969 double green_X, double green_Y, double green_Z, double blue_X,
1970 double blue_Y, double blue_Z))
1971 PNG_FIXED_EXPORT(136, void, png_set_cHRM_fixed, (png_const_structrp png_ptr,
1972 png_inforp info_ptr, png_fixed_point int_white_x,
1973 png_fixed_point int_white_y, png_fixed_point int_red_x,
1974 png_fixed_point int_red_y, png_fixed_point int_green_x,
1975 png_fixed_point int_green_y, png_fixed_point int_blue_x,
1976 png_fixed_point int_blue_y))
1977 PNG_FIXED_EXPORT(233, void, png_set_cHRM_XYZ_fixed, (png_const_structrp png_ptr,
1978 png_inforp info_ptr, png_fixed_point int_red_X, png_fixed_point int_red_Y,
1979 png_fixed_point int_red_Z, png_fixed_point int_green_X,
1980 png_fixed_point int_green_Y, png_fixed_point int_green_Z,
1981 png_fixed_point int_blue_X, png_fixed_point int_blue_Y,
1982 png_fixed_point int_blue_Z))
1983 #endif
1984
1985 #ifdef PNG_gAMA_SUPPORTED
1986 PNG_FP_EXPORT(137, png_uint_32, png_get_gAMA, (png_const_structrp png_ptr,
1987 png_const_inforp info_ptr, double *file_gamma))
1988 PNG_FIXED_EXPORT(138, png_uint_32, png_get_gAMA_fixed,
1989 (png_const_structrp png_ptr, png_const_inforp info_ptr,
1990 png_fixed_point *int_file_gamma))
1991 #endif
1992
1993 #ifdef PNG_gAMA_SUPPORTED
1994 PNG_FP_EXPORT(139, void, png_set_gAMA, (png_const_structrp png_ptr,
1995 png_inforp info_ptr, double file_gamma))
1996 PNG_FIXED_EXPORT(140, void, png_set_gAMA_fixed, (png_const_structrp png_ptr,
1997 png_inforp info_ptr, png_fixed_point int_file_gamma))
1998 #endif
1999
2000 #ifdef PNG_hIST_SUPPORTED
2001 PNG_EXPORT(141, png_uint_32, png_get_hIST, (png_const_structrp png_ptr,
2002 png_inforp info_ptr, png_uint_16p *hist));
2003 #endif
2004
2005 #ifdef PNG_hIST_SUPPORTED
2006 PNG_EXPORT(142, void, png_set_hIST, (png_const_structrp png_ptr,
2007 png_inforp info_ptr, png_const_uint_16p hist));
2008 #endif
2009
2010 PNG_EXPORT(143, png_uint_32, png_get_IHDR, (png_const_structrp png_ptr,
2011 png_const_inforp info_ptr, png_uint_32 *width, png_uint_32 *height,
2012 int *bit_depth, int *color_type, int *interlace_method,
2013 int *compression_method, int *filter_method));
2014
2015 PNG_EXPORT(144, void, png_set_IHDR, (png_const_structrp png_ptr,
2016 png_inforp info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth,
2017 int color_type, int interlace_method, int compression_method,
2018 int filter_method));
2019
2020 #ifdef PNG_oFFs_SUPPORTED
2021 PNG_EXPORT(145, png_uint_32, png_get_oFFs, (png_const_structrp png_ptr,
2022 png_const_inforp info_ptr, png_int_32 *offset_x, png_int_32 *offset_y,
2023 int *unit_type));
2024 #endif
2025
2026 #ifdef PNG_oFFs_SUPPORTED
2027 PNG_EXPORT(146, void, png_set_oFFs, (png_const_structrp png_ptr,
2028 png_inforp info_ptr, png_int_32 offset_x, png_int_32 offset_y,
2029 int unit_type));
2030 #endif
2031
2032 #ifdef PNG_pCAL_SUPPORTED
2033 PNG_EXPORT(147, png_uint_32, png_get_pCAL, (png_const_structrp png_ptr,
2034 png_inforp info_ptr, png_charp *purpose, png_int_32 *X0,
2035 png_int_32 *X1, int *type, int *nparams, png_charp *units,
2036 png_charpp *params));
2037 #endif
2038
2039 #ifdef PNG_pCAL_SUPPORTED
2040 PNG_EXPORT(148, void, png_set_pCAL, (png_const_structrp png_ptr,
2041 png_inforp info_ptr, png_const_charp purpose, png_int_32 X0, png_int_32 X1,
2042 int type, int nparams, png_const_charp units, png_charpp params));
2043 #endif
2044
2045 #ifdef PNG_pHYs_SUPPORTED
2046 PNG_EXPORT(149, png_uint_32, png_get_pHYs, (png_const_structrp png_ptr,
2047 png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y,
2048 int *unit_type));
2049 #endif
2050
2051 #ifdef PNG_pHYs_SUPPORTED
2052 PNG_EXPORT(150, void, png_set_pHYs, (png_const_structrp png_ptr,
2053 png_inforp info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type));
2054 #endif
2055
2056 PNG_EXPORT(151, png_uint_32, png_get_PLTE, (png_const_structrp png_ptr,
2057 png_inforp info_ptr, png_colorp *palette, int *num_palette));
2058
2059 PNG_EXPORT(152, void, png_set_PLTE, (png_structrp png_ptr,
2060 png_inforp info_ptr, png_const_colorp palette, int num_palette));
2061
2062 #ifdef PNG_sBIT_SUPPORTED
2063 PNG_EXPORT(153, png_uint_32, png_get_sBIT, (png_const_structrp png_ptr,
2064 png_inforp info_ptr, png_color_8p *sig_bit));
2065 #endif
2066
2067 #ifdef PNG_sBIT_SUPPORTED
2068 PNG_EXPORT(154, void, png_set_sBIT, (png_const_structrp png_ptr,
2069 png_inforp info_ptr, png_const_color_8p sig_bit));
2070 #endif
2071
2072 #ifdef PNG_sRGB_SUPPORTED
2073 PNG_EXPORT(155, png_uint_32, png_get_sRGB, (png_const_structrp png_ptr,
2074 png_const_inforp info_ptr, int *file_srgb_intent));
2075 #endif
2076
2077 #ifdef PNG_sRGB_SUPPORTED
2078 PNG_EXPORT(156, void, png_set_sRGB, (png_const_structrp png_ptr,
2079 png_inforp info_ptr, int srgb_intent));
2080 PNG_EXPORT(157, void, png_set_sRGB_gAMA_and_cHRM, (png_const_structrp png_ptr,
2081 png_inforp info_ptr, int srgb_intent));
2082 #endif
2083
2084 #ifdef PNG_iCCP_SUPPORTED
2085 PNG_EXPORT(158, png_uint_32, png_get_iCCP, (png_const_structrp png_ptr,
2086 png_inforp info_ptr, png_charpp name, int *compression_type,
2087 png_bytepp profile, png_uint_32 *proflen));
2088 #endif
2089
2090 #ifdef PNG_iCCP_SUPPORTED
2091 PNG_EXPORT(159, void, png_set_iCCP, (png_const_structrp png_ptr,
2092 png_inforp info_ptr, png_const_charp name, int compression_type,
2093 png_const_bytep profile, png_uint_32 proflen));
2094 #endif
2095
2096 #ifdef PNG_sPLT_SUPPORTED
2097 PNG_EXPORT(160, int, png_get_sPLT, (png_const_structrp png_ptr,
2098 png_inforp info_ptr, png_sPLT_tpp entries));
2099 #endif
2100
2101 #ifdef PNG_sPLT_SUPPORTED
2102 PNG_EXPORT(161, void, png_set_sPLT, (png_const_structrp png_ptr,
2103 png_inforp info_ptr, png_const_sPLT_tp entries, int nentries));
2104 #endif
2105
2106 #ifdef PNG_TEXT_SUPPORTED
2107 /* png_get_text also returns the number of text chunks in *num_text */
2108 PNG_EXPORT(162, int, png_get_text, (png_const_structrp png_ptr,
2109 png_inforp info_ptr, png_textp *text_ptr, int *num_text));
2110 #endif
2111
2112 /* Note while png_set_text() will accept a structure whose text,
2113 * language, and translated keywords are NULL pointers, the structure
2114 * returned by png_get_text will always contain regular
2115 * zero-terminated C strings. They might be empty strings but
2116 * they will never be NULL pointers.
2117 */
2118
2119 #ifdef PNG_TEXT_SUPPORTED
2120 PNG_EXPORT(163, void, png_set_text, (png_const_structrp png_ptr,
2121 png_inforp info_ptr, png_const_textp text_ptr, int num_text));
2122 #endif
2123
2124 #ifdef PNG_tIME_SUPPORTED
2125 PNG_EXPORT(164, png_uint_32, png_get_tIME, (png_const_structrp png_ptr,
2126 png_inforp info_ptr, png_timep *mod_time));
2127 #endif
2128
2129 #ifdef PNG_tIME_SUPPORTED
2130 PNG_EXPORT(165, void, png_set_tIME, (png_const_structrp png_ptr,
2131 png_inforp info_ptr, png_const_timep mod_time));
2132 #endif
2133
2134 #ifdef PNG_tRNS_SUPPORTED
2135 PNG_EXPORT(166, png_uint_32, png_get_tRNS, (png_const_structrp png_ptr,
2136 png_inforp info_ptr, png_bytep *trans_alpha, int *num_trans,
2137 png_color_16p *trans_color));
2138 #endif
2139
2140 #ifdef PNG_tRNS_SUPPORTED
2141 PNG_EXPORT(167, void, png_set_tRNS, (png_structrp png_ptr,
2142 png_inforp info_ptr, png_const_bytep trans_alpha, int num_trans,
2143 png_const_color_16p trans_color));
2144 #endif
2145
2146 #ifdef PNG_sCAL_SUPPORTED
2147 PNG_FP_EXPORT(168, png_uint_32, png_get_sCAL, (png_const_structrp png_ptr,
2148 png_const_inforp info_ptr, int *unit, double *width, double *height))
2149 #if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || \
2150 defined(PNG_FLOATING_POINT_SUPPORTED)
2151 /* NOTE: this API is currently implemented using floating point arithmetic,
2152 * consequently it can only be used on systems with floating point support.
2153 * In any case the range of values supported by png_fixed_point is small and it
2154 * is highly recommended that png_get_sCAL_s be used instead.
2155 */
2156 PNG_FIXED_EXPORT(214, png_uint_32, png_get_sCAL_fixed,
2157 (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit,
2158 png_fixed_point *width, png_fixed_point *height))
2159 #endif
2160 PNG_EXPORT(169, png_uint_32, png_get_sCAL_s,
2161 (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit,
2162 png_charpp swidth, png_charpp sheight));
2163
2164 PNG_FP_EXPORT(170, void, png_set_sCAL, (png_const_structrp png_ptr,
2165 png_inforp info_ptr, int unit, double width, double height))
2166 PNG_FIXED_EXPORT(213, void, png_set_sCAL_fixed, (png_const_structrp png_ptr,
2167 png_inforp info_ptr, int unit, png_fixed_point width,
2168 png_fixed_point height))
2169 PNG_EXPORT(171, void, png_set_sCAL_s, (png_const_structrp png_ptr,
2170 png_inforp info_ptr, int unit,
2171 png_const_charp swidth, png_const_charp sheight));
2172 #endif /* sCAL */
2173
2174 #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
2175 /* Provide the default handling for all unknown chunks or, optionally, for
2176 * specific unknown chunks.
2177 *
2178 * NOTE: prior to 1.6.0 the handling specified for particular chunks on read was
2179 * ignored and the default was used, the per-chunk setting only had an effect on
2180 * write. If you wish to have chunk-specific handling on read in code that must
2181 * work on earlier versions you must use a user chunk callback to specify the
2182 * desired handling (keep or discard.)
2183 *
2184 * The 'keep' parameter is a PNG_HANDLE_CHUNK_ value as listed below. The
2185 * parameter is interpreted as follows:
2186 *
2187 * READ:
2188 * PNG_HANDLE_CHUNK_AS_DEFAULT:
2189 * Known chunks: do normal libpng processing, do not keep the chunk (but
2190 * see the comments below about PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
2191 * Unknown chunks: for a specific chunk use the global default, when used
2192 * as the default discard the chunk data.
2193 * PNG_HANDLE_CHUNK_NEVER:
2194 * Discard the chunk data.
2195 * PNG_HANDLE_CHUNK_IF_SAFE:
2196 * Keep the chunk data if the chunk is not critical else raise a chunk
2197 * error.
2198 * PNG_HANDLE_CHUNK_ALWAYS:
2199 * Keep the chunk data.
2200 *
2201 * If the chunk data is saved it can be retrieved using png_get_unknown_chunks,
2202 * below. Notice that specifying "AS_DEFAULT" as a global default is equivalent
2203 * to specifying "NEVER", however when "AS_DEFAULT" is used for specific chunks
2204 * it simply resets the behavior to the libpng default.
2205 *
2206 * INTERACTION WTIH USER CHUNK CALLBACKS:
2207 * The per-chunk handling is always used when there is a png_user_chunk_ptr
2208 * callback and the callback returns 0; the chunk is then always stored *unless*
2209 * it is critical and the per-chunk setting is other than ALWAYS. Notice that
2210 * the global default is *not* used in this case. (In effect the per-chunk
2211 * value is incremented to at least IF_SAFE.)
2212 *
2213 * IMPORTANT NOTE: this behavior will change in libpng 1.7 - the global and
2214 * per-chunk defaults will be honored. If you want to preserve the current
2215 * behavior when your callback returns 0 you must set PNG_HANDLE_CHUNK_IF_SAFE
2216 * as the default - if you don't do this libpng 1.6 will issue a warning.
2217 *
2218 * If you want unhandled unknown chunks to be discarded in libpng 1.6 and
2219 * earlier simply return '1' (handled).
2220 *
2221 * PNG_HANDLE_AS_UNKNOWN_SUPPORTED:
2222 * If this is *not* set known chunks will always be handled by libpng and
2223 * will never be stored in the unknown chunk list. Known chunks listed to
2224 * png_set_keep_unknown_chunks will have no effect. If it is set then known
2225 * chunks listed with a keep other than AS_DEFAULT will *never* be processed
2226 * by libpng, in addition critical chunks must either be processed by the
2227 * callback or saved.
2228 *
2229 * The IHDR and IEND chunks must not be listed. Because this turns off the
2230 * default handling for chunks that would otherwise be recognized the
2231 * behavior of libpng transformations may well become incorrect!
2232 *
2233 * WRITE:
2234 * When writing chunks the options only apply to the chunks specified by
2235 * png_set_unknown_chunks (below), libpng will *always* write known chunks
2236 * required by png_set_ calls and will always write the core critical chunks
2237 * (as required for PLTE).
2238 *
2239 * Each chunk in the png_set_unknown_chunks list is looked up in the
2240 * png_set_keep_unknown_chunks list to find the keep setting, this is then
2241 * interpreted as follows:
2242 *
2243 * PNG_HANDLE_CHUNK_AS_DEFAULT:
2244 * Write safe-to-copy chunks and write other chunks if the global
2245 * default is set to _ALWAYS, otherwise don't write this chunk.
2246 * PNG_HANDLE_CHUNK_NEVER:
2247 * Do not write the chunk.
2248 * PNG_HANDLE_CHUNK_IF_SAFE:
2249 * Write the chunk if it is safe-to-copy, otherwise do not write it.
2250 * PNG_HANDLE_CHUNK_ALWAYS:
2251 * Write the chunk.
2252 *
2253 * Note that the default behavior is effectively the opposite of the read case -
2254 * in read unknown chunks are not stored by default, in write they are written
2255 * by default. Also the behavior of PNG_HANDLE_CHUNK_IF_SAFE is very different
2256 * - on write the safe-to-copy bit is checked, on read the critical bit is
2257 * checked and on read if the chunk is critical an error will be raised.
2258 *
2259 * num_chunks:
2260 * ===========
2261 * If num_chunks is positive, then the "keep" parameter specifies the manner
2262 * for handling only those chunks appearing in the chunk_list array,
2263 * otherwise the chunk list array is ignored.
2264 *
2265 * If num_chunks is 0 the "keep" parameter specifies the default behavior for
2266 * unknown chunks, as described above.
2267 *
2268 * If num_chunks is negative, then the "keep" parameter specifies the manner
2269 * for handling all unknown chunks plus all chunks recognized by libpng
2270 * except for the IHDR, PLTE, tRNS, IDAT, and IEND chunks (which continue to
2271 * be processed by libpng.
2272 */
2273 PNG_EXPORT(172, void, png_set_keep_unknown_chunks, (png_structrp png_ptr,
2274 int keep, png_const_bytep chunk_list, int num_chunks));
2275
2276 /* The "keep" PNG_HANDLE_CHUNK_ parameter for the specified chunk is returned;
2277 * the result is therefore true (non-zero) if special handling is required,
2278 * false for the default handling.
2279 */
2280 PNG_EXPORT(173, int, png_handle_as_unknown, (png_const_structrp png_ptr,
2281 png_const_bytep chunk_name));
2282 #endif
2283
2284 #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
2285 PNG_EXPORT(174, void, png_set_unknown_chunks, (png_const_structrp png_ptr,
2286 png_inforp info_ptr, png_const_unknown_chunkp unknowns,
2287 int num_unknowns));
2288 /* NOTE: prior to 1.6.0 this routine set the 'location' field of the added
2289 * unknowns to the location currently stored in the png_struct. This is
2290 * invariably the wrong value on write. To fix this call the following API
2291 * for each chunk in the list with the correct location. If you know your
2292 * code won't be compiled on earlier versions you can rely on
2293 * png_set_unknown_chunks(write-ptr, png_get_unknown_chunks(read-ptr)) doing
2294 * the correct thing.
2295 */
2296
2297 PNG_EXPORT(175, void, png_set_unknown_chunk_location,
2298 (png_const_structrp png_ptr, png_inforp info_ptr, int chunk, int location));
2299
2300 PNG_EXPORT(176, int, png_get_unknown_chunks, (png_const_structrp png_ptr,
2301 png_inforp info_ptr, png_unknown_chunkpp entries));
2302 #endif
2303
2304 /* Png_free_data() will turn off the "valid" flag for anything it frees.
2305 * If you need to turn it off for a chunk that your application has freed,
2306 * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK);
2307 */
2308 PNG_EXPORT(177, void, png_set_invalid, (png_const_structrp png_ptr,
2309 png_inforp info_ptr, int mask));
2310
2311 #ifdef PNG_INFO_IMAGE_SUPPORTED
2312 /* The "params" pointer is currently not used and is for future expansion. */
2313 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
2314 PNG_EXPORT(178, void, png_read_png, (png_structrp png_ptr, png_inforp info_ptr,
2315 int transforms, png_voidp params));
2316 #endif
2317 #ifdef PNG_WRITE_SUPPORTED
2318 PNG_EXPORT(179, void, png_write_png, (png_structrp png_ptr, png_inforp info_ptr,
2319 int transforms, png_voidp params));
2320 #endif
2321 #endif
2322
2323 PNG_EXPORT(180, png_const_charp, png_get_copyright,
2324 (png_const_structrp png_ptr));
2325 PNG_EXPORT(181, png_const_charp, png_get_header_ver,
2326 (png_const_structrp png_ptr));
2327 PNG_EXPORT(182, png_const_charp, png_get_header_version,
2328 (png_const_structrp png_ptr));
2329 PNG_EXPORT(183, png_const_charp, png_get_libpng_ver,
2330 (png_const_structrp png_ptr));
2331
2332 #ifdef PNG_MNG_FEATURES_SUPPORTED
2333 PNG_EXPORT(184, png_uint_32, png_permit_mng_features, (png_structrp png_ptr,
2334 png_uint_32 mng_features_permitted));
2335 #endif
2336
2337 /* For use in png_set_keep_unknown, added to version 1.2.6 */
2338 #define PNG_HANDLE_CHUNK_AS_DEFAULT 0
2339 #define PNG_HANDLE_CHUNK_NEVER 1
2340 #define PNG_HANDLE_CHUNK_IF_SAFE 2
2341 #define PNG_HANDLE_CHUNK_ALWAYS 3
2342 #define PNG_HANDLE_CHUNK_LAST 4
2343
2344 /* Strip the prepended error numbers ("#nnn ") from error and warning
2345 * messages before passing them to the error or warning handler.
2346 */
2347 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
2348 PNG_EXPORT(185, void, png_set_strip_error_numbers, (png_structrp png_ptr,
2349 png_uint_32 strip_mode));
2350 #endif
2351
2352 /* Added in libpng-1.2.6 */
2353 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
2354 PNG_EXPORT(186, void, png_set_user_limits, (png_structrp png_ptr,
2355 png_uint_32 user_width_max, png_uint_32 user_height_max));
2356 PNG_EXPORT(187, png_uint_32, png_get_user_width_max,
2357 (png_const_structrp png_ptr));
2358 PNG_EXPORT(188, png_uint_32, png_get_user_height_max,
2359 (png_const_structrp png_ptr));
2360 /* Added in libpng-1.4.0 */
2361 PNG_EXPORT(189, void, png_set_chunk_cache_max, (png_structrp png_ptr,
2362 png_uint_32 user_chunk_cache_max));
2363 PNG_EXPORT(190, png_uint_32, png_get_chunk_cache_max,
2364 (png_const_structrp png_ptr));
2365 /* Added in libpng-1.4.1 */
2366 PNG_EXPORT(191, void, png_set_chunk_malloc_max, (png_structrp png_ptr,
2367 png_alloc_size_t user_chunk_cache_max));
2368 PNG_EXPORT(192, png_alloc_size_t, png_get_chunk_malloc_max,
2369 (png_const_structrp png_ptr));
2370 #endif
2371
2372 #if defined(PNG_INCH_CONVERSIONS_SUPPORTED)
2373 PNG_EXPORT(193, png_uint_32, png_get_pixels_per_inch,
2374 (png_const_structrp png_ptr, png_const_inforp info_ptr));
2375
2376 PNG_EXPORT(194, png_uint_32, png_get_x_pixels_per_inch,
2377 (png_const_structrp png_ptr, png_const_inforp info_ptr));
2378
2379 PNG_EXPORT(195, png_uint_32, png_get_y_pixels_per_inch,
2380 (png_const_structrp png_ptr, png_const_inforp info_ptr));
2381
2382 PNG_FP_EXPORT(196, float, png_get_x_offset_inches,
2383 (png_const_structrp png_ptr, png_const_inforp info_ptr))
2384 #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */
2385 PNG_FIXED_EXPORT(211, png_fixed_point, png_get_x_offset_inches_fixed,
2386 (png_const_structrp png_ptr, png_const_inforp info_ptr))
2387 #endif
2388
2389 PNG_FP_EXPORT(197, float, png_get_y_offset_inches, (png_const_structrp png_ptr,
2390 png_const_inforp info_ptr))
2391 #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */
2392 PNG_FIXED_EXPORT(212, png_fixed_point, png_get_y_offset_inches_fixed,
2393 (png_const_structrp png_ptr, png_const_inforp info_ptr))
2394 #endif
2395
2396 # ifdef PNG_pHYs_SUPPORTED
2397 PNG_EXPORT(198, png_uint_32, png_get_pHYs_dpi, (png_const_structrp png_ptr,
2398 png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y,
2399 int *unit_type));
2400 # endif /* pHYs */
2401 #endif /* INCH_CONVERSIONS */
2402
2403 /* Added in libpng-1.4.0 */
2404 #ifdef PNG_IO_STATE_SUPPORTED
2405 PNG_EXPORT(199, png_uint_32, png_get_io_state, (png_const_structrp png_ptr));
2406
2407 /* Removed from libpng 1.6; use png_get_io_chunk_type. */
2408 PNG_REMOVED(200, png_const_bytep, png_get_io_chunk_name, (png_structrp png_ptr),
2409 PNG_DEPRECATED)
2410
2411 PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type,
2412 (png_const_structrp png_ptr));
2413
2414 /* The flags returned by png_get_io_state() are the following: */
2415 # define PNG_IO_NONE 0x0000 /* no I/O at this moment */
2416 # define PNG_IO_READING 0x0001 /* currently reading */
2417 # define PNG_IO_WRITING 0x0002 /* currently writing */
2418 # define PNG_IO_SIGNATURE 0x0010 /* currently at the file signature */
2419 # define PNG_IO_CHUNK_HDR 0x0020 /* currently at the chunk header */
2420 # define PNG_IO_CHUNK_DATA 0x0040 /* currently at the chunk data */
2421 # define PNG_IO_CHUNK_CRC 0x0080 /* currently at the chunk crc */
2422 # define PNG_IO_MASK_OP 0x000f /* current operation: reading/writing */
2423 # define PNG_IO_MASK_LOC 0x00f0 /* current location: sig/hdr/data/crc */
2424 #endif /* IO_STATE */
2425
2426 /* Interlace support. The following macros are always defined so that if
2427 * libpng interlace handling is turned off the macros may be used to handle
2428 * interlaced images within the application.
2429 */
2430 #define PNG_INTERLACE_ADAM7_PASSES 7
2431
2432 /* Two macros to return the first row and first column of the original,
2433 * full, image which appears in a given pass. 'pass' is in the range 0
2434 * to 6 and the result is in the range 0 to 7.
2435 */
2436 #define PNG_PASS_START_ROW(pass) (((1&~(pass))<<(3-((pass)>>1)))&7)
2437 #define PNG_PASS_START_COL(pass) (((1& (pass))<<(3-(((pass)+1)>>1)))&7)
2438
2439 /* A macro to return the offset between pixels in the output row for a pair of
2440 * pixels in the input - effectively the inverse of the 'COL_SHIFT' macro that
2441 * follows. Note that ROW_OFFSET is the offset from one row to the next whereas
2442 * COL_OFFSET is from one column to the next, within a row.
2443 */
2444 #define PNG_PASS_ROW_OFFSET(pass) ((pass)>2?(8>>(((pass)-1)>>1)):8)
2445 #define PNG_PASS_COL_OFFSET(pass) (1<<((7-(pass))>>1))
2446
2447 /* Two macros to help evaluate the number of rows or columns in each
2448 * pass. This is expressed as a shift - effectively log2 of the number or
2449 * rows or columns in each 8x8 tile of the original image.
2450 */
2451 #define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3)
2452 #define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3)
2453
2454 /* Hence two macros to determine the number of rows or columns in a given
2455 * pass of an image given its height or width. In fact these macros may
2456 * return non-zero even though the sub-image is empty, because the other
2457 * dimension may be empty for a small image.
2458 */
2459 #define PNG_PASS_ROWS(height, pass) (((height)+(((1<<PNG_PASS_ROW_SHIFT(pass))\
2460 -1)-PNG_PASS_START_ROW(pass)))>>PNG_PASS_ROW_SHIFT(pass))
2461 #define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\
2462 -1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass))
2463
2464 /* For the reader row callbacks (both progressive and sequential) it is
2465 * necessary to find the row in the output image given a row in an interlaced
2466 * image, so two more macros:
2467 */
2468 #define PNG_ROW_FROM_PASS_ROW(y_in, pass) \
2469 (((y_in)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass))
2470 #define PNG_COL_FROM_PASS_COL(x_in, pass) \
2471 (((x_in)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass))
2472
2473 /* Two macros which return a boolean (0 or 1) saying whether the given row
2474 * or column is in a particular pass. These use a common utility macro that
2475 * returns a mask for a given pass - the offset 'off' selects the row or
2476 * column version. The mask has the appropriate bit set for each column in
2477 * the tile.
2478 */
2479 #define PNG_PASS_MASK(pass,off) ( \
2480 ((0x110145AF>>(((7-(off))-(pass))<<2)) & 0xF) | \
2481 ((0x01145AF0>>(((7-(off))-(pass))<<2)) & 0xF0))
2482
2483 #define PNG_ROW_IN_INTERLACE_PASS(y, pass) \
2484 ((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1)
2485 #define PNG_COL_IN_INTERLACE_PASS(x, pass) \
2486 ((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1)
2487
2488 #ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
2489 /* With these routines we avoid an integer divide, which will be slower on
2490 * most machines. However, it does take more operations than the corresponding
2491 * divide method, so it may be slower on a few RISC systems. There are two
2492 * shifts (by 8 or 16 bits) and an addition, versus a single integer divide.
2493 *
2494 * Note that the rounding factors are NOT supposed to be the same! 128 and
2495 * 32768 are correct for the NODIV code; 127 and 32767 are correct for the
2496 * standard method.
2497 *
2498 * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
2499 */
2500
2501 /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */
2502
2503 # define png_composite(composite, fg, alpha, bg) \
2504 { png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \
2505 * (png_uint_16)(alpha) \
2506 + (png_uint_16)(bg)*(png_uint_16)(255 \
2507 - (png_uint_16)(alpha)) + 128); \
2508 (composite) = (png_byte)(((temp + (temp >> 8)) >> 8) & 0xff); }
2509
2510 # define png_composite_16(composite, fg, alpha, bg) \
2511 { png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) \
2512 * (png_uint_32)(alpha) \
2513 + (png_uint_32)(bg)*(65535 \
2514 - (png_uint_32)(alpha)) + 32768); \
2515 (composite) = (png_uint_16)(0xffff & ((temp + (temp >> 16)) >> 16)); }
2516
2517 #else /* Standard method using integer division */
2518
2519 # define png_composite(composite, fg, alpha, bg) \
2520 (composite) = \
2521 (png_byte)(0xff & (((png_uint_16)(fg) * (png_uint_16)(alpha) + \
2522 (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \
2523 127) / 255))
2524
2525 # define png_composite_16(composite, fg, alpha, bg) \
2526 (composite) = \
2527 (png_uint_16)(0xffff & (((png_uint_32)(fg) * (png_uint_32)(alpha) + \
2528 (png_uint_32)(bg)*(png_uint_32)(65535 - (png_uint_32)(alpha)) + \
2529 32767) / 65535))
2530 #endif /* READ_COMPOSITE_NODIV */
2531
2532 #ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED
2533 PNG_EXPORT(201, png_uint_32, png_get_uint_32, (png_const_bytep buf));
2534 PNG_EXPORT(202, png_uint_16, png_get_uint_16, (png_const_bytep buf));
2535 PNG_EXPORT(203, png_int_32, png_get_int_32, (png_const_bytep buf));
2536 #endif
2537
2538 PNG_EXPORT(204, png_uint_32, png_get_uint_31, (png_const_structrp png_ptr,
2539 png_const_bytep buf));
2540 /* No png_get_int_16 -- may be added if there's a real need for it. */
2541
2542 /* Place a 32-bit number into a buffer in PNG byte order (big-endian). */
2543 #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
2544 PNG_EXPORT(205, void, png_save_uint_32, (png_bytep buf, png_uint_32 i));
2545 #endif
2546 #ifdef PNG_SAVE_INT_32_SUPPORTED
2547 PNG_EXPORT(206, void, png_save_int_32, (png_bytep buf, png_int_32 i));
2548 #endif
2549
2550 /* Place a 16-bit number into a buffer in PNG byte order.
2551 * The parameter is declared unsigned int, not png_uint_16,
2552 * just to avoid potential problems on pre-ANSI C compilers.
2553 */
2554 #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
2555 PNG_EXPORT(207, void, png_save_uint_16, (png_bytep buf, unsigned int i));
2556 /* No png_save_int_16 -- may be added if there's a real need for it. */
2557 #endif
2558
2559 #ifdef PNG_USE_READ_MACROS
2560 /* Inline macros to do direct reads of bytes from the input buffer.
2561 * The png_get_int_32() routine assumes we are using two's complement
2562 * format for negative values, which is almost certainly true.
2563 */
2564 # define PNG_get_uint_32(buf) \
2565 (((png_uint_32)(*(buf)) << 24) + \
2566 ((png_uint_32)(*((buf) + 1)) << 16) + \
2567 ((png_uint_32)(*((buf) + 2)) << 8) + \
2568 ((png_uint_32)(*((buf) + 3))))
2569
2570 /* From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the
2571 * function) incorrectly returned a value of type png_uint_32.
2572 */
2573 # define PNG_get_uint_16(buf) \
2574 ((png_uint_16) \
2575 (((unsigned int)(*(buf)) << 8) + \
2576 ((unsigned int)(*((buf) + 1)))))
2577
2578 # define PNG_get_int_32(buf) \
2579 ((png_int_32)((*(buf) & 0x80) \
2580 ? -((png_int_32)(((png_get_uint_32(buf)^0xffffffffU)+1U)&0x7fffffffU)) \
2581 : (png_int_32)png_get_uint_32(buf)))
2582
2583 /* If PNG_PREFIX is defined the same thing as below happens in pnglibconf.h,
2584 * but defining a macro name prefixed with PNG_PREFIX.
2585 */
2586 # ifndef PNG_PREFIX
2587 # define png_get_uint_32(buf) PNG_get_uint_32(buf)
2588 # define png_get_uint_16(buf) PNG_get_uint_16(buf)
2589 # define png_get_int_32(buf) PNG_get_int_32(buf)
2590 # endif
2591 #else
2592 # ifdef PNG_PREFIX
2593 /* No macros; revert to the (redefined) function */
2594 # define PNG_get_uint_32 (png_get_uint_32)
2595 # define PNG_get_uint_16 (png_get_uint_16)
2596 # define PNG_get_int_32 (png_get_int_32)
2597 # endif
2598 #endif
2599
2600 #ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
2601 PNG_EXPORT(242, void, png_set_check_for_invalid_index,
2602 (png_structrp png_ptr, int allowed));
2603 # ifdef PNG_GET_PALETTE_MAX_SUPPORTED
2604 PNG_EXPORT(243, int, png_get_palette_max, (png_const_structp png_ptr,
2605 png_const_infop info_ptr));
2606 # endif
2607 #endif /* CHECK_FOR_INVALID_INDEX */
2608
2609 /*******************************************************************************
2610 * Section 5: SIMPLIFIED API
2611 *******************************************************************************
2612 *
2613 * Please read the documentation in libpng-manual.txt (TODO: write said
2614 * documentation) if you don't understand what follows.
2615 *
2616 * The simplified API hides the details of both libpng and the PNG file format
2617 * itself. It allows PNG files to be read into a very limited number of
2618 * in-memory bitmap formats or to be written from the same formats. If these
2619 * formats do not accomodate your needs then you can, and should, use the more
2620 * sophisticated APIs above - these support a wide variety of in-memory formats
2621 * and a wide variety of sophisticated transformations to those formats as well
2622 * as a wide variety of APIs to manipulate ancillary information.
2623 *
2624 * To read a PNG file using the simplified API:
2625 *
2626 * 1) Declare a 'png_image' structure (see below) on the stack, set the
2627 * version field to PNG_IMAGE_VERSION and the 'opaque' pointer to NULL
2628 * (this is REQUIRED, your program may crash if you don't do it.)
2629 * 2) Call the appropriate png_image_begin_read... function.
2630 * 3) Set the png_image 'format' member to the required sample format.
2631 * 4) Allocate a buffer for the image and, if required, the color-map.
2632 * 5) Call png_image_finish_read to read the image and, if required, the
2633 * color-map into your buffers.
2634 *
2635 * There are no restrictions on the format of the PNG input itself; all valid
2636 * color types, bit depths, and interlace methods are acceptable, and the
2637 * input image is transformed as necessary to the requested in-memory format
2638 * during the png_image_finish_read() step. The only caveat is that if you
2639 * request a color-mapped image from a PNG that is full-color or makes
2640 * complex use of an alpha channel the transformation is extremely lossy and the
2641 * result may look terrible.
2642 *
2643 * To write a PNG file using the simplified API:
2644 *
2645 * 1) Declare a 'png_image' structure on the stack and memset() it to all zero.
2646 * 2) Initialize the members of the structure that describe the image, setting
2647 * the 'format' member to the format of the image samples.
2648 * 3) Call the appropriate png_image_write... function with a pointer to the
2649 * image and, if necessary, the color-map to write the PNG data.
2650 *
2651 * png_image is a structure that describes the in-memory format of an image
2652 * when it is being read or defines the in-memory format of an image that you
2653 * need to write:
2654 */
2655 #if defined(PNG_SIMPLIFIED_READ_SUPPORTED) || \
2656 defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
2657
2658 #define PNG_IMAGE_VERSION 1
2659
2660 typedef struct png_control *png_controlp;
2661 typedef struct
2662 {
2663 png_controlp opaque; /* Initialize to NULL, free with png_image_free */
2664 png_uint_32 version; /* Set to PNG_IMAGE_VERSION */
2665 png_uint_32 width; /* Image width in pixels (columns) */
2666 png_uint_32 height; /* Image height in pixels (rows) */
2667 png_uint_32 format; /* Image format as defined below */
2668 png_uint_32 flags; /* A bit mask containing informational flags */
2669 png_uint_32 colormap_entries;
2670 /* Number of entries in the color-map */
2671
2672 /* In the event of an error or warning the following field will be set to a
2673 * non-zero value and the 'message' field will contain a '\0' terminated
2674 * string with the libpng error or warning message. If both warnings and
2675 * an error were encountered, only the error is recorded. If there
2676 * are multiple warnings, only the first one is recorded.
2677 *
2678 * The upper 30 bits of this value are reserved, the low two bits contain
2679 * a value as follows:
2680 */
2681 # define PNG_IMAGE_WARNING 1
2682 # define PNG_IMAGE_ERROR 2
2683 /*
2684 * The result is a two-bit code such that a value more than 1 indicates
2685 * a failure in the API just called:
2686 *
2687 * 0 - no warning or error
2688 * 1 - warning
2689 * 2 - error
2690 * 3 - error preceded by warning
2691 */
2692 # define PNG_IMAGE_FAILED(png_cntrl) ((((png_cntrl).warning_or_error)&0x03)>1)
2693
2694 png_uint_32 warning_or_error;
2695
2696 char message[64];
2697 } png_image, *png_imagep;
2698
2699 /* The samples of the image have one to four channels whose components have
2700 * original values in the range 0 to 1.0:
2701 *
2702 * 1: A single gray or luminance channel (G).
2703 * 2: A gray/luminance channel and an alpha channel (GA).
2704 * 3: Three red, green, blue color channels (RGB).
2705 * 4: Three color channels and an alpha channel (RGBA).
2706 *
2707 * The components are encoded in one of two ways:
2708 *
2709 * a) As a small integer, value 0..255, contained in a single byte. For the
2710 * alpha channel the original value is simply value/255. For the color or
2711 * luminance channels the value is encoded according to the sRGB specification
2712 * and matches the 8-bit format expected by typical display devices.
2713 *
2714 * The color/gray channels are not scaled (pre-multiplied) by the alpha
2715 * channel and are suitable for passing to color management software.
2716 *
2717 * b) As a value in the range 0..65535, contained in a 2-byte integer. All
2718 * channels can be converted to the original value by dividing by 65535; all
2719 * channels are linear. Color channels use the RGB encoding (RGB end-points) of
2720 * the sRGB specification. This encoding is identified by the
2721 * PNG_FORMAT_FLAG_LINEAR flag below.
2722 *
2723 * When the simplified API needs to convert between sRGB and linear colorspaces,
2724 * the actual sRGB transfer curve defined in the sRGB specification (see the
2725 * article at http://en.wikipedia.org/wiki/SRGB) is used, not the gamma=1/2.2
2726 * approximation used elsewhere in libpng.
2727 *
2728 * When an alpha channel is present it is expected to denote pixel coverage
2729 * of the color or luminance channels and is returned as an associated alpha
2730 * channel: the color/gray channels are scaled (pre-multiplied) by the alpha
2731 * value.
2732 *
2733 * The samples are either contained directly in the image data, between 1 and 8
2734 * bytes per pixel according to the encoding, or are held in a color-map indexed
2735 * by bytes in the image data. In the case of a color-map the color-map entries
2736 * are individual samples, encoded as above, and the image data has one byte per
2737 * pixel to select the relevant sample from the color-map.
2738 */
2739
2740 /* PNG_FORMAT_*
2741 *
2742 * #defines to be used in png_image::format. Each #define identifies a
2743 * particular layout of sample data and, if present, alpha values. There are
2744 * separate defines for each of the two component encodings.
2745 *
2746 * A format is built up using single bit flag values. All combinations are
2747 * valid. Formats can be built up from the flag values or you can use one of
2748 * the predefined values below. When testing formats always use the FORMAT_FLAG
2749 * macros to test for individual features - future versions of the library may
2750 * add new flags.
2751 *
2752 * When reading or writing color-mapped images the format should be set to the
2753 * format of the entries in the color-map then png_image_{read,write}_colormap
2754 * called to read or write the color-map and set the format correctly for the
2755 * image data. Do not set the PNG_FORMAT_FLAG_COLORMAP bit directly!
2756 *
2757 * NOTE: libpng can be built with particular features disabled. If you see
2758 * compiler errors because the definition of one of the following flags has been
2759 * compiled out it is because libpng does not have the required support. It is
2760 * possible, however, for the libpng configuration to enable the format on just
2761 * read or just write; in that case you may see an error at run time. You can
2762 * guard against this by checking for the definition of the appropriate
2763 * "_SUPPORTED" macro, one of:
2764 *
2765 * PNG_SIMPLIFIED_{READ,WRITE}_{BGR,AFIRST}_SUPPORTED
2766 */
2767 #define PNG_FORMAT_FLAG_ALPHA 0x01U /* format with an alpha channel */
2768 #define PNG_FORMAT_FLAG_COLOR 0x02U /* color format: otherwise grayscale */
2769 #define PNG_FORMAT_FLAG_LINEAR 0x04U /* 2-byte channels else 1-byte */
2770 #define PNG_FORMAT_FLAG_COLORMAP 0x08U /* image data is color-mapped */
2771
2772 #ifdef PNG_FORMAT_BGR_SUPPORTED
2773 # define PNG_FORMAT_FLAG_BGR 0x10U /* BGR colors, else order is RGB */
2774 #endif
2775
2776 #ifdef PNG_FORMAT_AFIRST_SUPPORTED
2777 # define PNG_FORMAT_FLAG_AFIRST 0x20U /* alpha channel comes first */
2778 #endif
2779
2780 /* Commonly used formats have predefined macros.
2781 *
2782 * First the single byte (sRGB) formats:
2783 */
2784 #define PNG_FORMAT_GRAY 0
2785 #define PNG_FORMAT_GA PNG_FORMAT_FLAG_ALPHA
2786 #define PNG_FORMAT_AG (PNG_FORMAT_GA|PNG_FORMAT_FLAG_AFIRST)
2787 #define PNG_FORMAT_RGB PNG_FORMAT_FLAG_COLOR
2788 #define PNG_FORMAT_BGR (PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_BGR)
2789 #define PNG_FORMAT_RGBA (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_ALPHA)
2790 #define PNG_FORMAT_ARGB (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_AFIRST)
2791 #define PNG_FORMAT_BGRA (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_ALPHA)
2792 #define PNG_FORMAT_ABGR (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_AFIRST)
2793
2794 /* Then the linear 2-byte formats. When naming these "Y" is used to
2795 * indicate a luminance (gray) channel.
2796 */
2797 #define PNG_FORMAT_LINEAR_Y PNG_FORMAT_FLAG_LINEAR
2798 #define PNG_FORMAT_LINEAR_Y_ALPHA (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_ALPHA)
2799 #define PNG_FORMAT_LINEAR_RGB (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR)
2800 #define PNG_FORMAT_LINEAR_RGB_ALPHA \
2801 (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA)
2802
2803 /* With color-mapped formats the image data is one byte for each pixel, the byte
2804 * is an index into the color-map which is formatted as above. To obtain a
2805 * color-mapped format it is sufficient just to add the PNG_FOMAT_FLAG_COLORMAP
2806 * to one of the above definitions, or you can use one of the definitions below.
2807 */
2808 #define PNG_FORMAT_RGB_COLORMAP (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_COLORMAP)
2809 #define PNG_FORMAT_BGR_COLORMAP (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_COLORMAP)
2810 #define PNG_FORMAT_RGBA_COLORMAP (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_COLORMAP)
2811 #define PNG_FORMAT_ARGB_COLORMAP (PNG_FORMAT_ARGB|PNG_FORMAT_FLAG_COLORMAP)
2812 #define PNG_FORMAT_BGRA_COLORMAP (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_COLORMAP)
2813 #define PNG_FORMAT_ABGR_COLORMAP (PNG_FORMAT_ABGR|PNG_FORMAT_FLAG_COLORMAP)
2814
2815 /* PNG_IMAGE macros
2816 *
2817 * These are convenience macros to derive information from a png_image
2818 * structure. The PNG_IMAGE_SAMPLE_ macros return values appropriate to the
2819 * actual image sample values - either the entries in the color-map or the
2820 * pixels in the image. The PNG_IMAGE_PIXEL_ macros return corresponding values
2821 * for the pixels and will always return 1 for color-mapped formats. The
2822 * remaining macros return information about the rows in the image and the
2823 * complete image.
2824 *
2825 * NOTE: All the macros that take a png_image::format parameter are compile time
2826 * constants if the format parameter is, itself, a constant. Therefore these
2827 * macros can be used in array declarations and case labels where required.
2828 * Similarly the macros are also pre-processor constants (sizeof is not used) so
2829 * they can be used in #if tests.
2830 *
2831 * First the information about the samples.
2832 */
2833 #define PNG_IMAGE_SAMPLE_CHANNELS(fmt)\
2834 (((fmt)&(PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA))+1)
2835 /* Return the total number of channels in a given format: 1..4 */
2836
2837 #define PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)\
2838 ((((fmt) & PNG_FORMAT_FLAG_LINEAR) >> 2)+1)
2839 /* Return the size in bytes of a single component of a pixel or color-map
2840 * entry (as appropriate) in the image: 1 or 2.
2841 */
2842
2843 #define PNG_IMAGE_SAMPLE_SIZE(fmt)\
2844 (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt))
2845 /* This is the size of the sample data for one sample. If the image is
2846 * color-mapped it is the size of one color-map entry (and image pixels are
2847 * one byte in size), otherwise it is the size of one image pixel.
2848 */
2849
2850 #define PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(fmt)\
2851 (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * 256)
2852 /* The maximum size of the color-map required by the format expressed in a
2853 * count of components. This can be used to compile-time allocate a
2854 * color-map:
2855 *
2856 * png_uint_16 colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(linear_fmt)];
2857 *
2858 * png_byte colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(sRGB_fmt)];
2859 *
2860 * Alternatively use the PNG_IMAGE_COLORMAP_SIZE macro below to use the
2861 * information from one of the png_image_begin_read_ APIs and dynamically
2862 * allocate the required memory.
2863 */
2864
2865 /* Corresponding information about the pixels */
2866 #define PNG_IMAGE_PIXEL_(test,fmt)\
2867 (((fmt)&PNG_FORMAT_FLAG_COLORMAP)?1:test(fmt))
2868
2869 #define PNG_IMAGE_PIXEL_CHANNELS(fmt)\
2870 PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_CHANNELS,fmt)
2871 /* The number of separate channels (components) in a pixel; 1 for a
2872 * color-mapped image.
2873 */
2874
2875 #define PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt)\
2876 PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_COMPONENT_SIZE,fmt)
2877 /* The size, in bytes, of each component in a pixel; 1 for a color-mapped
2878 * image.
2879 */
2880
2881 #define PNG_IMAGE_PIXEL_SIZE(fmt) PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_SIZE,fmt)
2882 /* The size, in bytes, of a complete pixel; 1 for a color-mapped image. */
2883
2884 /* Information about the whole row, or whole image */
2885 #define PNG_IMAGE_ROW_STRIDE(image)\
2886 (PNG_IMAGE_PIXEL_CHANNELS((image).format) * (image).width)
2887 /* Return the total number of components in a single row of the image; this
2888 * is the minimum 'row stride', the minimum count of components between each
2889 * row. For a color-mapped image this is the minimum number of bytes in a
2890 * row.
2891 */
2892
2893 #define PNG_IMAGE_BUFFER_SIZE(image, row_stride)\
2894 (PNG_IMAGE_PIXEL_COMPONENT_SIZE((image).format)*(image).height*(row_stride))
2895 /* Return the size, in bytes, of an image buffer given a png_image and a row
2896 * stride - the number of components to leave space for in each row.
2897 */
2898
2899 #define PNG_IMAGE_SIZE(image)\
2900 PNG_IMAGE_BUFFER_SIZE(image, PNG_IMAGE_ROW_STRIDE(image))
2901 /* Return the size, in bytes, of the image in memory given just a png_image;
2902 * the row stride is the minimum stride required for the image.
2903 */
2904
2905 #define PNG_IMAGE_COLORMAP_SIZE(image)\
2906 (PNG_IMAGE_SAMPLE_SIZE((image).format) * (image).colormap_entries)
2907 /* Return the size, in bytes, of the color-map of this image. If the image
2908 * format is not a color-map format this will return a size sufficient for
2909 * 256 entries in the given format; check PNG_FORMAT_FLAG_COLORMAP if
2910 * you don't want to allocate a color-map in this case.
2911 */
2912
2913 /* PNG_IMAGE_FLAG_*
2914 *
2915 * Flags containing additional information about the image are held in the
2916 * 'flags' field of png_image.
2917 */
2918 #define PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB 0x01
2919 /* This indicates the the RGB values of the in-memory bitmap do not
2920 * correspond to the red, green and blue end-points defined by sRGB.
2921 */
2922
2923 #define PNG_IMAGE_FLAG_FAST 0x02
2924 /* On write emphasise speed over compression; the resultant PNG file will be
2925 * larger but will be produced significantly faster, particular for large
2926 * images. Do not use this option for images which will be distributed, only
2927 * used it when producing intermediate files that will be read back in
2928 * repeatedly. For a typical 24-bit image the option will double the read
2929 * speed at the cost of increasing the image size by 25%, however for many
2930 * more compressible images the PNG file can be 10 times larger with only a
2931 * slight speed gain.
2932 */
2933
2934 #define PNG_IMAGE_FLAG_16BIT_sRGB 0x04
2935 /* On read if the image is a 16-bit per component image and there is no gAMA
2936 * or sRGB chunk assume that the components are sRGB encoded. Notice that
2937 * images output by the simplified API always have gamma information; setting
2938 * this flag only affects the interpretation of 16-bit images from an
2939 * external source. It is recommended that the application expose this flag
2940 * to the user; the user can normally easily recognize the difference between
2941 * linear and sRGB encoding. This flag has no effect on write - the data
2942 * passed to the write APIs must have the correct encoding (as defined
2943 * above.)
2944 *
2945 * If the flag is not set (the default) input 16-bit per component data is
2946 * assumed to be linear.
2947 *
2948 * NOTE: the flag can only be set after the png_image_begin_read_ call,
2949 * because that call initializes the 'flags' field.
2950 */
2951
2952 #ifdef PNG_SIMPLIFIED_READ_SUPPORTED
2953 /* READ APIs
2954 * ---------
2955 *
2956 * The png_image passed to the read APIs must have been initialized by setting
2957 * the png_controlp field 'opaque' to NULL (or, safer, memset the whole thing.)
2958 */
2959 #ifdef PNG_STDIO_SUPPORTED
2960 PNG_EXPORT(234, int, png_image_begin_read_from_file, (png_imagep image,
2961 const char *file_name));
2962 /* The named file is opened for read and the image header is filled in
2963 * from the PNG header in the file.
2964 */
2965
2966 PNG_EXPORT(235, int, png_image_begin_read_from_stdio, (png_imagep image,
2967 FILE* file));
2968 /* The PNG header is read from the stdio FILE object. */
2969 #endif /* STDIO */
2970
2971 PNG_EXPORT(236, int, png_image_begin_read_from_memory, (png_imagep image,
2972 png_const_voidp memory, png_size_t size));
2973 /* The PNG header is read from the given memory buffer. */
2974
2975 PNG_EXPORT(237, int, png_image_finish_read, (png_imagep image,
2976 png_const_colorp background, void *buffer, png_int_32 row_stride,
2977 void *colormap));
2978 /* Finish reading the image into the supplied buffer and clean up the
2979 * png_image structure.
2980 *
2981 * row_stride is the step, in byte or 2-byte units as appropriate,
2982 * between adjacent rows. A positive stride indicates that the top-most row
2983 * is first in the buffer - the normal top-down arrangement. A negative
2984 * stride indicates that the bottom-most row is first in the buffer.
2985 *
2986 * background need only be supplied if an alpha channel must be removed from
2987 * a png_byte format and the removal is to be done by compositing on a solid
2988 * color; otherwise it may be NULL and any composition will be done directly
2989 * onto the buffer. The value is an sRGB color to use for the background,
2990 * for grayscale output the green channel is used.
2991 *
2992 * background must be supplied when an alpha channel must be removed from a
2993 * single byte color-mapped output format, in other words if:
2994 *
2995 * 1) The original format from png_image_begin_read_from_* had
2996 * PNG_FORMAT_FLAG_ALPHA set.
2997 * 2) The format set by the application does not.
2998 * 3) The format set by the application has PNG_FORMAT_FLAG_COLORMAP set and
2999 * PNG_FORMAT_FLAG_LINEAR *not* set.
3000 *
3001 * For linear output removing the alpha channel is always done by compositing
3002 * on black and background is ignored.
3003 *
3004 * colormap must be supplied when PNG_FORMAT_FLAG_COLORMAP is set. It must
3005 * be at least the size (in bytes) returned by PNG_IMAGE_COLORMAP_SIZE.
3006 * image->colormap_entries will be updated to the actual number of entries
3007 * written to the colormap; this may be less than the original value.
3008 */
3009
3010 PNG_EXPORT(238, void, png_image_free, (png_imagep image));
3011 /* Free any data allocated by libpng in image->opaque, setting the pointer to
3012 * NULL. May be called at any time after the structure is initialized.
3013 */
3014 #endif /* SIMPLIFIED_READ */
3015
3016 #ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED
3017 #ifdef PNG_STDIO_SUPPORTED
3018 /* WRITE APIS
3019 * ----------
3020 * For write you must initialize a png_image structure to describe the image to
3021 * be written. To do this use memset to set the whole structure to 0 then
3022 * initialize fields describing your image.
3023 *
3024 * version: must be set to PNG_IMAGE_VERSION
3025 * opaque: must be initialized to NULL
3026 * width: image width in pixels
3027 * height: image height in rows
3028 * format: the format of the data (image and color-map) you wish to write
3029 * flags: set to 0 unless one of the defined flags applies; set
3030 * PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB for color format images where the RGB
3031 * values do not correspond to the colors in sRGB.
3032 * colormap_entries: set to the number of entries in the color-map (0 to 256)
3033 */
3034 PNG_EXPORT(239, int, png_image_write_to_file, (png_imagep image,
3035 const char *file, int convert_to_8bit, const void *buffer,
3036 png_int_32 row_stride, const void *colormap));
3037 /* Write the image to the named file. */
3038
3039 PNG_EXPORT(240, int, png_image_write_to_stdio, (png_imagep image, FILE *file,
3040 int convert_to_8_bit, const void *buffer, png_int_32 row_stride,
3041 const void *colormap));
3042 /* Write the image to the given (FILE*). */
3043
3044 /* With both write APIs if image is in one of the linear formats with 16-bit
3045 * data then setting convert_to_8_bit will cause the output to be an 8-bit PNG
3046 * gamma encoded according to the sRGB specification, otherwise a 16-bit linear
3047 * encoded PNG file is written.
3048 *
3049 * With color-mapped data formats the colormap parameter point to a color-map
3050 * with at least image->colormap_entries encoded in the specified format. If
3051 * the format is linear the written PNG color-map will be converted to sRGB
3052 * regardless of the convert_to_8_bit flag.
3053 *
3054 * With all APIs row_stride is handled as in the read APIs - it is the spacing
3055 * from one row to the next in component sized units (1 or 2 bytes) and if
3056 * negative indicates a bottom-up row layout in the buffer. If row_stride is zero,
3057 * libpng will calculate it for you from the image width and number of channels.
3058 *
3059 * Note that the write API does not support interlacing, sub-8-bit pixels, indexed
3060 * PNG (color_type 3) or most ancillary chunks.
3061 */
3062 #endif /* STDIO */
3063 #endif /* SIMPLIFIED_WRITE */
3064 /*******************************************************************************
3065 * END OF SIMPLIFIED API
3066 ******************************************************************************/
3067 #endif /* SIMPLIFIED_{READ|WRITE} */
3068
3069 /*******************************************************************************
3070 * Section 6: IMPLEMENTATION OPTIONS
3071 *******************************************************************************
3072 *
3073 * Support for arbitrary implementation-specific optimizations. The API allows
3074 * particular options to be turned on or off. 'Option' is the number of the
3075 * option and 'onoff' is 0 (off) or non-0 (on). The value returned is given
3076 * by the PNG_OPTION_ defines below.
3077 *
3078 * HARDWARE: normally hardware capabilites, such as the Intel SSE instructions,
3079 * are detected at run time, however sometimes it may be impossible
3080 * to do this in user mode, in which case it is necessary to discover
3081 * the capabilities in an OS specific way. Such capabilities are
3082 * listed here when libpng has support for them and must be turned
3083 * ON by the application if present.
3084 *
3085 * SOFTWARE: sometimes software optimizations actually result in performance
3086 * decrease on some architectures or systems, or with some sets of
3087 * PNG images. 'Software' options allow such optimizations to be
3088 * selected at run time.
3089 */
3090 #ifdef PNG_SET_OPTION_SUPPORTED
3091 #ifdef PNG_ARM_NEON_API_SUPPORTED
3092 # define PNG_ARM_NEON 0 /* HARDWARE: ARM Neon SIMD instructions supported */
3093 #endif
3094 #define PNG_MAXIMUM_INFLATE_WINDOW 2 /* SOFTWARE: force maximum window */
3095 #define PNG_SKIP_sRGB_CHECK_PROFILE 4 /* SOFTWARE: Check ICC profile for sRGB */
3096 #define PNG_OPTION_NEXT 6 /* Next option - numbers must be even */
3097
3098 /* Return values: NOTE: there are four values and 'off' is *not* zero */
3099 #define PNG_OPTION_UNSET 0 /* Unset - defaults to off */
3100 #define PNG_OPTION_INVALID 1 /* Option number out of range */
3101 #define PNG_OPTION_OFF 2
3102 #define PNG_OPTION_ON 3
3103
3104 PNG_EXPORT(244, int, png_set_option, (png_structrp png_ptr, int option,
3105 int onoff));
3106 #endif /* SET_OPTION */
3107
3108 /*******************************************************************************
3109 * END OF HARDWARE AND SOFTWARE OPTIONS
3110 ******************************************************************************/
3111
3112 /* Maintainer: Put new public prototypes here ^, in libpng.3, in project
3113 * defs, and in scripts/symbols.def.
3114 */
3115
3116 /* The last ordinal number (this is the *last* one already used; the next
3117 * one to use is one more than this.)
3118 */
3119 #ifdef PNG_EXPORT_LAST_ORDINAL
3120 PNG_EXPORT_LAST_ORDINAL(244);
3121 #endif
3122
3123 #ifdef __cplusplus
3124 }
3125 #endif
3126
3127 #endif /* PNG_VERSION_INFO_ONLY */
3128 /* Do not put anything past this line */
3129 #endif /* PNG_H */