2 /* png.h - header file for PNG reference library
4 * libpng version 1.5.2 - March 31, 2011
5 * Copyright (c) 1998-2011 Glenn Randers-Pehrson
6 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
7 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
9 * This code is released under the libpng license (See LICENSE, below)
11 * Authors and maintainers:
12 * libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
13 * libpng versions 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger
14 * libpng versions 0.97, January 1998, through 1.5.2 - March 31, 2011: Glenn
15 * See also "Contributing Authors", below.
17 * Note about libpng version numbers:
19 * Due to various miscommunications, unforeseen code incompatibilities
20 * and occasional factors outside the authors' control, version numbering
21 * on the library has not always been consistent and straightforward.
22 * The following table summarizes matters since version 0.89c, which was
23 * the first widely used release:
25 * source png.h png.h shared-lib
26 * version string int version
27 * ------- ------ ----- ----------
28 * 0.89c "1.0 beta 3" 0.89 89 1.0.89
29 * 0.90 "1.0 beta 4" 0.90 90 0.90 [should have been 2.0.90]
30 * 0.95 "1.0 beta 5" 0.95 95 0.95 [should have been 2.0.95]
31 * 0.96 "1.0 beta 6" 0.96 96 0.96 [should have been 2.0.96]
32 * 0.97b "1.00.97 beta 7" 1.00.97 97 1.0.1 [should have been 2.0.97]
33 * 0.97c 0.97 97 2.0.97
36 * 0.99a-m 0.99 99 2.0.99
37 * 1.00 1.00 100 2.1.0 [100 should be 10000]
38 * 1.0.0 (from here on, the 100 2.1.0 [100 should be 10000]
39 * 1.0.1 png.h string is 10001 2.1.0
40 * 1.0.1a-e identical to the 10002 from here on, the shared library
41 * 1.0.2 source version) 10002 is 2.V where V is the source code
42 * 1.0.2a-b 10003 version, except as noted.
47 * 1.0.5 (+ 2 patches) 10005
49 * 1.0.5e-r 10100 (not source compatible)
50 * 1.0.5s-v 10006 (not binary compatible)
51 * 1.0.6 (+ 3 patches) 10006 (still binary incompatible)
52 * 1.0.6d-f 10007 (still binary incompatible)
54 * 1.0.6h 10007 10.6h (testing xy.z so-numbering)
56 * 1.0.6j 10007 2.1.0.6j (incompatible with 1.0.0)
57 * 1.0.7beta11-14 DLLNUM 10007 2.1.0.7beta11-14 (binary compatible)
58 * 1.0.7beta15-18 1 10007 2.1.0.7beta15-18 (binary compatible)
59 * 1.0.7rc1-2 1 10007 2.1.0.7rc1-2 (binary compatible)
60 * 1.0.7 1 10007 (still compatible)
61 * 1.0.8beta1-4 1 10008 2.1.0.8beta1-4
62 * 1.0.8rc1 1 10008 2.1.0.8rc1
63 * 1.0.8 1 10008 2.1.0.8
64 * 1.0.9beta1-6 1 10009 2.1.0.9beta1-6
65 * 1.0.9rc1 1 10009 2.1.0.9rc1
66 * 1.0.9beta7-10 1 10009 2.1.0.9beta7-10
67 * 1.0.9rc2 1 10009 2.1.0.9rc2
68 * 1.0.9 1 10009 2.1.0.9
69 * 1.0.10beta1 1 10010 2.1.0.10beta1
70 * 1.0.10rc1 1 10010 2.1.0.10rc1
71 * 1.0.10 1 10010 2.1.0.10
72 * 1.0.11beta1-3 1 10011 2.1.0.11beta1-3
73 * 1.0.11rc1 1 10011 2.1.0.11rc1
74 * 1.0.11 1 10011 2.1.0.11
75 * 1.0.12beta1-2 2 10012 2.1.0.12beta1-2
76 * 1.0.12rc1 2 10012 2.1.0.12rc1
77 * 1.0.12 2 10012 2.1.0.12
78 * 1.1.0a-f - 10100 2.1.1.0a-f (branch abandoned)
79 * 1.2.0beta1-2 2 10200 2.1.2.0beta1-2
80 * 1.2.0beta3-5 3 10200 3.1.2.0beta3-5
81 * 1.2.0rc1 3 10200 3.1.2.0rc1
82 * 1.2.0 3 10200 3.1.2.0
83 * 1.2.1beta1-4 3 10201 3.1.2.1beta1-4
84 * 1.2.1rc1-2 3 10201 3.1.2.1rc1-2
85 * 1.2.1 3 10201 3.1.2.1
86 * 1.2.2beta1-6 12 10202 12.so.0.1.2.2beta1-6
87 * 1.0.13beta1 10 10013 10.so.0.1.0.13beta1
88 * 1.0.13rc1 10 10013 10.so.0.1.0.13rc1
89 * 1.2.2rc1 12 10202 12.so.0.1.2.2rc1
90 * 1.0.13 10 10013 10.so.0.1.0.13
91 * 1.2.2 12 10202 12.so.0.1.2.2
92 * 1.2.3rc1-6 12 10203 12.so.0.1.2.3rc1-6
93 * 1.2.3 12 10203 12.so.0.1.2.3
94 * 1.2.4beta1-3 13 10204 12.so.0.1.2.4beta1-3
95 * 1.0.14rc1 13 10014 10.so.0.1.0.14rc1
96 * 1.2.4rc1 13 10204 12.so.0.1.2.4rc1
97 * 1.0.14 10 10014 10.so.0.1.0.14
98 * 1.2.4 13 10204 12.so.0.1.2.4
99 * 1.2.5beta1-2 13 10205 12.so.0.1.2.5beta1-2
100 * 1.0.15rc1-3 10 10015 10.so.0.1.0.15rc1-3
101 * 1.2.5rc1-3 13 10205 12.so.0.1.2.5rc1-3
102 * 1.0.15 10 10015 10.so.0.1.0.15
103 * 1.2.5 13 10205 12.so.0.1.2.5
104 * 1.2.6beta1-4 13 10206 12.so.0.1.2.6beta1-4
105 * 1.0.16 10 10016 10.so.0.1.0.16
106 * 1.2.6 13 10206 12.so.0.1.2.6
107 * 1.2.7beta1-2 13 10207 12.so.0.1.2.7beta1-2
108 * 1.0.17rc1 10 10017 12.so.0.1.0.17rc1
109 * 1.2.7rc1 13 10207 12.so.0.1.2.7rc1
110 * 1.0.17 10 10017 12.so.0.1.0.17
111 * 1.2.7 13 10207 12.so.0.1.2.7
112 * 1.2.8beta1-5 13 10208 12.so.0.1.2.8beta1-5
113 * 1.0.18rc1-5 10 10018 12.so.0.1.0.18rc1-5
114 * 1.2.8rc1-5 13 10208 12.so.0.1.2.8rc1-5
115 * 1.0.18 10 10018 12.so.0.1.0.18
116 * 1.2.8 13 10208 12.so.0.1.2.8
117 * 1.2.9beta1-3 13 10209 12.so.0.1.2.9beta1-3
118 * 1.2.9beta4-11 13 10209 12.so.0.9[.0]
119 * 1.2.9rc1 13 10209 12.so.0.9[.0]
120 * 1.2.9 13 10209 12.so.0.9[.0]
121 * 1.2.10beta1-7 13 10210 12.so.0.10[.0]
122 * 1.2.10rc1-2 13 10210 12.so.0.10[.0]
123 * 1.2.10 13 10210 12.so.0.10[.0]
124 * 1.4.0beta1-5 14 10400 14.so.0.0[.0]
125 * 1.2.11beta1-4 13 10211 12.so.0.11[.0]
126 * 1.4.0beta7-8 14 10400 14.so.0.0[.0]
127 * 1.2.11 13 10211 12.so.0.11[.0]
128 * 1.2.12 13 10212 12.so.0.12[.0]
129 * 1.4.0beta9-14 14 10400 14.so.0.0[.0]
130 * 1.2.13 13 10213 12.so.0.13[.0]
131 * 1.4.0beta15-36 14 10400 14.so.0.0[.0]
132 * 1.4.0beta37-87 14 10400 14.so.14.0[.0]
133 * 1.4.0rc01 14 10400 14.so.14.0[.0]
134 * 1.4.0beta88-109 14 10400 14.so.14.0[.0]
135 * 1.4.0rc02-08 14 10400 14.so.14.0[.0]
136 * 1.4.0 14 10400 14.so.14.0[.0]
137 * 1.4.1beta01-03 14 10401 14.so.14.1[.0]
138 * 1.4.1rc01 14 10401 14.so.14.1[.0]
139 * 1.4.1beta04-12 14 10401 14.so.14.1[.0]
140 * 1.4.1 14 10401 14.so.14.1[.0]
141 * 1.4.2 14 10402 14.so.14.2[.0]
142 * 1.4.3 14 10403 14.so.14.3[.0]
143 * 1.4.4 14 10404 14.so.14.4[.0]
144 * 1.5.0beta01-58 15 10500 15.so.15.0[.0]
145 * 1.5.0rc01-07 15 10500 15.so.15.0[.0]
146 * 1.5.0 15 10500 15.so.15.0[.0]
147 * 1.5.1beta01-11 15 10501 15.so.15.1[.0]
148 * 1.5.1rc01-02 15 10501 15.so.15.1[.0]
149 * 1.5.1 15 10501 15.so.15.1[.0]
150 * 1.5.2beta01-03 15 10502 15.so.15.2[.0]
151 * 1.5.2rc01-03 15 10502 15.so.15.2[.0]
152 * 1.5.2 15 10502 15.so.15.2[.0]
154 * Henceforth the source version will match the shared-library major
155 * and minor numbers; the shared-library major version number will be
156 * used for changes in backward compatibility, as it is intended. The
157 * PNG_LIBPNG_VER macro, which is not used within libpng but is available
158 * for applications, is an unsigned integer of the form xyyzz corresponding
159 * to the source version x.y.z (leading zeros in y and z). Beta versions
160 * were given the previous public release number plus a letter, until
161 * version 1.0.6j; from then on they were given the upcoming public
162 * release number plus "betaNN" or "rcN".
164 * Binary incompatibility exists only when applications make direct access
165 * to the info_ptr or png_ptr members through png.h, and the compiled
166 * application is loaded with a different version of the library.
168 * DLLNUM will change each time there are forward or backward changes
169 * in binary compatibility (e.g., when a new feature is added).
171 * See libpng-manual.txt or libpng.3 for more information. The PNG
172 * specification is available as a W3C Recommendation and as an ISO
173 * Specification, <http://www.w3.org/TR/2003/REC-PNG-20031110/
177 * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
179 * If you modify libpng you may insert additional notices immediately following
182 * This code is released under the libpng license.
184 * libpng versions 1.2.6, August 15, 2004, through 1.5.2, March 31, 2011, are
185 * Copyright (c) 2004, 2006-2011 Glenn Randers-Pehrson, and are
186 * distributed according to the same disclaimer and license as libpng-1.2.5
187 * with the following individual added to the list of Contributing Authors:
191 * libpng versions 1.0.7, July 1, 2000, through 1.2.5, October 3, 2002, are
192 * Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are
193 * distributed according to the same disclaimer and license as libpng-1.0.6
194 * with the following individuals added to the list of Contributing Authors:
196 * Simon-Pierre Cadieux
200 * and with the following additions to the disclaimer:
202 * There is no warranty against interference with your enjoyment of the
203 * library or against infringement. There is no warranty that our
204 * efforts or the library will fulfill any of your particular purposes
205 * or needs. This library is provided with all faults, and the entire
206 * risk of satisfactory quality, performance, accuracy, and effort is with
209 * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
210 * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson, and are
211 * distributed according to the same disclaimer and license as libpng-0.96,
212 * with the following individuals added to the list of Contributing Authors:
215 * Glenn Randers-Pehrson
218 * libpng versions 0.89, June 1996, through 0.96, May 1997, are
219 * Copyright (c) 1996, 1997 Andreas Dilger
220 * Distributed according to the same disclaimer and license as libpng-0.88,
221 * with the following individuals added to the list of Contributing Authors:
230 * libpng versions 0.5, May 1995, through 0.88, January 1996, are
231 * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
233 * For the purposes of this copyright and license, "Contributing Authors"
234 * is defined as the following set of individuals:
242 * The PNG Reference Library is supplied "AS IS". The Contributing Authors
243 * and Group 42, Inc. disclaim all warranties, expressed or implied,
244 * including, without limitation, the warranties of merchantability and of
245 * fitness for any purpose. The Contributing Authors and Group 42, Inc.
246 * assume no liability for direct, indirect, incidental, special, exemplary,
247 * or consequential damages, which may result from the use of the PNG
248 * Reference Library, even if advised of the possibility of such damage.
250 * Permission is hereby granted to use, copy, modify, and distribute this
251 * source code, or portions hereof, for any purpose, without fee, subject
252 * to the following restrictions:
254 * 1. The origin of this source code must not be misrepresented.
256 * 2. Altered versions must be plainly marked as such and must not
257 * be misrepresented as being the original source.
259 * 3. This Copyright notice may not be removed or altered from
260 * any source or altered source distribution.
262 * The Contributing Authors and Group 42, Inc. specifically permit, without
263 * fee, and encourage the use of this source code as a component to
264 * supporting the PNG file format in commercial products. If you use this
265 * source code in a product, acknowledgment is not required but would be
270 * A "png_get_copyright" function is available, for convenient use in "about"
271 * boxes and the like:
273 * printf("%s", png_get_copyright(NULL));
275 * Also, the PNG logo (in PNG format, of course) is supplied in the
276 * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
280 * Libpng is OSI Certified Open Source Software. OSI Certified is a
281 * certification mark of the Open Source Initiative.
285 * The contributing authors would like to thank all those who helped
286 * with testing, bug fixes, and patience. This wouldn't have been
287 * possible without all of you.
289 * Thanks to Frank J. T. Wojcik for helping with the documentation.
293 * Y2K compliance in libpng:
294 * =========================
298 * Since the PNG Development group is an ad-hoc body, we can't make
299 * an official declaration.
301 * This is your unofficial assurance that libpng from version 0.71 and
302 * upward through 1.5.2 are Y2K compliant. It is my belief that
303 * earlier versions were also Y2K compliant.
305 * Libpng only has three year fields. One is a 2-byte unsigned integer
306 * that will hold years up to 65535. The other two hold the date in text
307 * format, and will hold years up to 9999.
310 * "png_uint_16 year" in png_time_struct.
313 * "png_charp time_buffer" in png_struct and
314 * "near_time_buffer", which is a local character string in png.c.
316 * There are seven time-related functions:
317 * png.c: png_convert_to_rfc_1123() in png.c
318 * (formerly png_convert_to_rfc_1152() in error)
319 * png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
320 * png_convert_from_time_t() in pngwrite.c
321 * png_get_tIME() in pngget.c
322 * png_handle_tIME() in pngrutil.c, called in pngread.c
323 * png_set_tIME() in pngset.c
324 * png_write_tIME() in pngwutil.c, called in pngwrite.c
326 * All handle dates properly in a Y2K environment. The
327 * png_convert_from_time_t() function calls gmtime() to convert from system
328 * clock time, which returns (year - 1900), which we properly convert to
329 * the full 4-digit year. There is a possibility that applications using
330 * libpng are not passing 4-digit years into the png_convert_to_rfc_1123()
331 * function, or that they are incorrectly passing only a 2-digit year
332 * instead of "year - 1900" into the png_convert_from_struct_tm() function,
333 * but this is not under our control. The libpng documentation has always
334 * stated that it works with 4-digit years, and the APIs have been
335 * documented as such.
337 * The tIME chunk itself is also Y2K compliant. It uses a 2-byte unsigned
338 * integer to hold the year, and can hold years as large as 65535.
340 * zlib, upon which libpng depends, is also Y2K compliant. It contains
341 * no date-related code.
343 * Glenn Randers-Pehrson
345 * PNG Development Group
351 /* This is not the place to learn how to use libpng. The file libpng-manual.txt
352 * describes how to use libpng, and the file example.c summarizes it
353 * with some code on which to build. This file is useful for looking
354 * at the actual function definitions and structure components.
357 /* Version information for png.h - this should match the version in png.c */
358 #define PNG_LIBPNG_VER_STRING "1.5.2"
359 #define PNG_HEADER_VERSION_STRING \
360 " libpng version 1.5.2 - March 31, 2011\n"
362 #define PNG_LIBPNG_VER_SONUM 15
363 #define PNG_LIBPNG_VER_DLLNUM 15
365 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
366 #define PNG_LIBPNG_VER_MAJOR 1
367 #define PNG_LIBPNG_VER_MINOR 5
368 #define PNG_LIBPNG_VER_RELEASE 2
369 /* This should match the numeric part of the final component of
370 * PNG_LIBPNG_VER_STRING, omitting any leading zero:
373 #define PNG_LIBPNG_VER_BUILD 0
376 #define PNG_LIBPNG_BUILD_ALPHA 1
377 #define PNG_LIBPNG_BUILD_BETA 2
378 #define PNG_LIBPNG_BUILD_RC 3
379 #define PNG_LIBPNG_BUILD_STABLE 4
380 #define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7
382 /* Release-Specific Flags */
383 #define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with
384 PNG_LIBPNG_BUILD_STABLE only */
385 #define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with
386 PNG_LIBPNG_BUILD_SPECIAL */
387 #define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with
388 PNG_LIBPNG_BUILD_PRIVATE */
390 #define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_BETA
392 /* Careful here. At one time, Guy wanted to use 082, but that would be octal.
393 * We must not include leading zeros.
394 * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only
395 * version 1.0.0 was mis-numbered 100 instead of 10000). From
396 * version 1.0.1 it's xxyyzz, where x=major, y=minor, z=release
398 #define PNG_LIBPNG_VER 10502 /* 1.5.2 */
400 /* Library configuration: these options cannot be changed after
401 * the library has been built.
404 /* If pnglibconf.h is missing, you can
405 * copy scripts/pnglibconf.h.prebuilt to pnglibconf.h
407 # include "pnglibconf.h"
410 #ifndef PNG_VERSION_INFO_ONLY
411 # ifndef PNG_BUILDING_SYMBOL_TABLE
413 * Standard header files (not needed for the version info or while
414 * building symbol table -- see scripts/pnglibconf.dfa)
416 # ifdef PNG_SETJMP_SUPPORTED
420 /* Need the time information for converting tIME chunks, it
423 # ifdef PNG_CONVERT_tIME_SUPPORTED
424 /* "time.h" functions are not supported on all operating systems */
429 /* Machine specific configuration. */
430 # include "pngconf.h"
434 * Added at libpng-1.2.8
436 * Ref MSDN: Private as priority over Special
437 * VS_FF_PRIVATEBUILD File *was not* built using standard release
438 * procedures. If this value is given, the StringFileInfo block must
439 * contain a PrivateBuild string.
441 * VS_FF_SPECIALBUILD File *was* built by the original company using
442 * standard release procedures but is a variation of the standard
443 * file of the same version number. If this value is given, the
444 * StringFileInfo block must contain a SpecialBuild string.
447 #ifdef PNG_USER_PRIVATEBUILD /* From pnglibconf.h */
448 # define PNG_LIBPNG_BUILD_TYPE \
449 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE)
451 # ifdef PNG_LIBPNG_SPECIALBUILD
452 # define PNG_LIBPNG_BUILD_TYPE \
453 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL)
455 # define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE)
459 #ifndef PNG_VERSION_INFO_ONLY
461 /* Inhibit C++ name-mangling for libpng functions but not for system calls. */
464 #endif /* __cplusplus */
466 /* Version information for C files, stored in png.c. This had better match
469 #define png_libpng_ver png_get_header_ver(NULL)
471 /* This file is arranged in several sections:
473 * 1. Any configuration options that can be specified by for the application
474 * code when it is built. (Build time configuration is in pnglibconf.h)
475 * 2. Type definitions (base types are defined in pngconf.h), structure
477 * 3. Exported library functions.
479 * The library source code has additional files (principally pngpriv.h) that
480 * allow configuration of the library.
482 /* Section 1: run time configuration
483 * See pnglibconf.h for build time configuration
485 * Run time configuration allows the application to choose between
486 * implementations of certain arithmetic APIs. The default is set
487 * at build time and recorded in pnglibconf.h, but it is safe to
488 * override these (and only these) settings. Note that this won't
489 * change what the library does, only application code, and the
490 * settings can (and probably should) be made on a per-file basis
491 * by setting the #defines before including png.h
493 * Use macros to read integers from PNG data or use the exported
495 * PNG_USE_READ_MACROS: use the macros (see below) Note that
496 * the macros evaluate their argument multiple times.
497 * PNG_NO_USE_READ_MACROS: call the relevant library function.
499 * Use the alternative algorithm for compositing alpha samples that
500 * does not use division?
501 * PNG_READ_COMPOSITE_NODIV_SUPPORTED: use the 'no division'
503 * PNG_NO_READ_COMPOSITE_NODIV: use the 'division' algorithm.
505 * How to handle benign errors if PNG_ALLOW_BENIGN_ERRORS is
507 * PNG_ALLOW_BENIGN_ERRORS: map calls to the benign error
508 * APIs to png_warning.
509 * Otherwise the calls are mapped to png_error.
512 /* Section 2: type definitions, including structures and compile time
514 * See pngconf.h for base types that vary by machine/system
517 /* This triggers a compiler error in png.c, if png.c and png.h
518 * do not agree upon the version number.
520 typedef char* png_libpng_version_1_5_2;
522 /* Three color definitions. The order of the red, green, and blue, (and the
523 * exact size) is not important, although the size of the fields need to
524 * be png_byte or png_uint_16 (as defined below).
526 typedef struct png_color_struct
532 typedef png_color FAR * png_colorp;
533 typedef PNG_CONST png_color FAR * png_const_colorp;
534 typedef png_color FAR * FAR * png_colorpp;
536 typedef struct png_color_16_struct
538 png_byte index; /* used for palette files */
539 png_uint_16 red; /* for use in red green blue files */
542 png_uint_16 gray; /* for use in grayscale files */
544 typedef png_color_16 FAR * png_color_16p;
545 typedef PNG_CONST png_color_16 FAR * png_const_color_16p;
546 typedef png_color_16 FAR * FAR * png_color_16pp;
548 typedef struct png_color_8_struct
550 png_byte red; /* for use in red green blue files */
553 png_byte gray; /* for use in grayscale files */
554 png_byte alpha; /* for alpha channel files */
556 typedef png_color_8 FAR * png_color_8p;
557 typedef PNG_CONST png_color_8 FAR * png_const_color_8p;
558 typedef png_color_8 FAR * FAR * png_color_8pp;
561 * The following two structures are used for the in-core representation
564 typedef struct png_sPLT_entry_struct
570 png_uint_16 frequency;
572 typedef png_sPLT_entry FAR * png_sPLT_entryp;
573 typedef PNG_CONST png_sPLT_entry FAR * png_const_sPLT_entryp;
574 typedef png_sPLT_entry FAR * FAR * png_sPLT_entrypp;
576 /* When the depth of the sPLT palette is 8 bits, the color and alpha samples
577 * occupy the LSB of their respective members, and the MSB of each member
578 * is zero-filled. The frequency member always occupies the full 16 bits.
581 typedef struct png_sPLT_struct
583 png_charp name; /* palette name */
584 png_byte depth; /* depth of palette samples */
585 png_sPLT_entryp entries; /* palette entries */
586 png_int_32 nentries; /* number of palette entries */
588 typedef png_sPLT_t FAR * png_sPLT_tp;
589 typedef PNG_CONST png_sPLT_t FAR * png_const_sPLT_tp;
590 typedef png_sPLT_t FAR * FAR * png_sPLT_tpp;
592 #ifdef PNG_TEXT_SUPPORTED
593 /* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,
594 * and whether that contents is compressed or not. The "key" field
595 * points to a regular zero-terminated C string. The "text", "lang", and
596 * "lang_key" fields can be regular C strings, empty strings, or NULL pointers.
597 * However, the * structure returned by png_get_text() will always contain
598 * regular zero-terminated C strings (possibly empty), never NULL pointers,
599 * so they can be safely used in printf() and other string-handling functions.
601 typedef struct png_text_struct
603 int compression; /* compression value:
608 png_charp key; /* keyword, 1-79 character description of "text" */
609 png_charp text; /* comment, may be an empty string (ie "")
611 png_size_t text_length; /* length of the text string */
612 png_size_t itxt_length; /* length of the itxt string */
613 png_charp lang; /* language code, 0-79 characters
615 png_charp lang_key; /* keyword translated UTF-8 string, 0 or more
616 chars or a NULL pointer */
618 typedef png_text FAR * png_textp;
619 typedef PNG_CONST png_text FAR * png_const_textp;
620 typedef png_text FAR * FAR * png_textpp;
623 /* Supported compression types for text in PNG files (tEXt, and zTXt).
624 * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */
625 #define PNG_TEXT_COMPRESSION_NONE_WR -3
626 #define PNG_TEXT_COMPRESSION_zTXt_WR -2
627 #define PNG_TEXT_COMPRESSION_NONE -1
628 #define PNG_TEXT_COMPRESSION_zTXt 0
629 #define PNG_ITXT_COMPRESSION_NONE 1
630 #define PNG_ITXT_COMPRESSION_zTXt 2
631 #define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */
633 /* png_time is a way to hold the time in an machine independent way.
634 * Two conversions are provided, both from time_t and struct tm. There
635 * is no portable way to convert to either of these structures, as far
636 * as I know. If you know of a portable way, send it to me. As a side
637 * note - PNG has always been Year 2000 compliant!
639 typedef struct png_time_struct
641 png_uint_16 year; /* full year, as in, 1995 */
642 png_byte month; /* month of year, 1 - 12 */
643 png_byte day; /* day of month, 1 - 31 */
644 png_byte hour; /* hour of day, 0 - 23 */
645 png_byte minute; /* minute of hour, 0 - 59 */
646 png_byte second; /* second of minute, 0 - 60 (for leap seconds) */
648 typedef png_time FAR * png_timep;
649 typedef PNG_CONST png_time FAR * png_const_timep;
650 typedef png_time FAR * FAR * png_timepp;
652 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) || \
653 defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
654 /* png_unknown_chunk is a structure to hold queued chunks for which there is
655 * no specific support. The idea is that we can use this to queue
656 * up private chunks for output even though the library doesn't actually
657 * know about their semantics.
659 typedef struct png_unknown_chunk_t
665 /* libpng-using applications should NOT directly modify this byte. */
666 png_byte location; /* mode of operation at read time */
669 typedef png_unknown_chunk FAR * png_unknown_chunkp;
670 typedef PNG_CONST png_unknown_chunk FAR * png_const_unknown_chunkp;
671 typedef png_unknown_chunk FAR * FAR * png_unknown_chunkpp;
674 typedef struct png_info_def png_info;
675 typedef png_info FAR * png_infop;
676 typedef PNG_CONST png_info FAR * png_const_infop;
677 typedef png_info FAR * FAR * png_infopp;
679 /* Maximum positive integer used in PNG is (2^31)-1 */
680 #define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL)
681 #define PNG_UINT_32_MAX ((png_uint_32)(-1))
682 #define PNG_SIZE_MAX ((png_size_t)(-1))
684 /* These are constants for fixed point values encoded in the
685 * PNG specification manner (x100000)
687 #define PNG_FP_1 100000
688 #define PNG_FP_HALF 50000
690 /* These describe the color_type field in png_info. */
691 /* color type masks */
692 #define PNG_COLOR_MASK_PALETTE 1
693 #define PNG_COLOR_MASK_COLOR 2
694 #define PNG_COLOR_MASK_ALPHA 4
696 /* color types. Note that not all combinations are legal */
697 #define PNG_COLOR_TYPE_GRAY 0
698 #define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
699 #define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR)
700 #define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
701 #define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
703 #define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA
704 #define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA
706 /* This is for compression type. PNG 1.0-1.2 only define the single type. */
707 #define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */
708 #define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE
710 /* This is for filter type. PNG 1.0-1.2 only define the single type. */
711 #define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */
712 #define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */
713 #define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE
715 /* These are for the interlacing type. These values should NOT be changed. */
716 #define PNG_INTERLACE_NONE 0 /* Non-interlaced image */
717 #define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */
718 #define PNG_INTERLACE_LAST 2 /* Not a valid value */
720 /* These are for the oFFs chunk. These values should NOT be changed. */
721 #define PNG_OFFSET_PIXEL 0 /* Offset in pixels */
722 #define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */
723 #define PNG_OFFSET_LAST 2 /* Not a valid value */
725 /* These are for the pCAL chunk. These values should NOT be changed. */
726 #define PNG_EQUATION_LINEAR 0 /* Linear transformation */
727 #define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */
728 #define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */
729 #define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */
730 #define PNG_EQUATION_LAST 4 /* Not a valid value */
732 /* These are for the sCAL chunk. These values should NOT be changed. */
733 #define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */
734 #define PNG_SCALE_METER 1 /* meters per pixel */
735 #define PNG_SCALE_RADIAN 2 /* radians per pixel */
736 #define PNG_SCALE_LAST 3 /* Not a valid value */
738 /* These are for the pHYs chunk. These values should NOT be changed. */
739 #define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */
740 #define PNG_RESOLUTION_METER 1 /* pixels/meter */
741 #define PNG_RESOLUTION_LAST 2 /* Not a valid value */
743 /* These are for the sRGB chunk. These values should NOT be changed. */
744 #define PNG_sRGB_INTENT_PERCEPTUAL 0
745 #define PNG_sRGB_INTENT_RELATIVE 1
746 #define PNG_sRGB_INTENT_SATURATION 2
747 #define PNG_sRGB_INTENT_ABSOLUTE 3
748 #define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */
750 /* This is for text chunks */
751 #define PNG_KEYWORD_MAX_LENGTH 79
753 /* Maximum number of entries in PLTE/sPLT/tRNS arrays */
754 #define PNG_MAX_PALETTE_LENGTH 256
756 /* These determine if an ancillary chunk's data has been successfully read
757 * from the PNG header, or if the application has filled in the corresponding
758 * data in the info_struct to be written into the output file. The values
759 * of the PNG_INFO_<chunk> defines should NOT be changed.
761 #define PNG_INFO_gAMA 0x0001
762 #define PNG_INFO_sBIT 0x0002
763 #define PNG_INFO_cHRM 0x0004
764 #define PNG_INFO_PLTE 0x0008
765 #define PNG_INFO_tRNS 0x0010
766 #define PNG_INFO_bKGD 0x0020
767 #define PNG_INFO_hIST 0x0040
768 #define PNG_INFO_pHYs 0x0080
769 #define PNG_INFO_oFFs 0x0100
770 #define PNG_INFO_tIME 0x0200
771 #define PNG_INFO_pCAL 0x0400
772 #define PNG_INFO_sRGB 0x0800 /* GR-P, 0.96a */
773 #define PNG_INFO_iCCP 0x1000 /* ESR, 1.0.6 */
774 #define PNG_INFO_sPLT 0x2000 /* ESR, 1.0.6 */
775 #define PNG_INFO_sCAL 0x4000 /* ESR, 1.0.6 */
776 #define PNG_INFO_IDAT 0x8000L /* ESR, 1.0.6 */
778 /* This is used for the transformation routines, as some of them
779 * change these values for the row. It also should enable using
780 * the routines for other purposes.
782 typedef struct png_row_info_struct
784 png_uint_32 width; /* width of row */
785 png_size_t rowbytes; /* number of bytes in row */
786 png_byte color_type; /* color type of row */
787 png_byte bit_depth; /* bit depth of row */
788 png_byte channels; /* number of channels (1, 2, 3, or 4) */
789 png_byte pixel_depth; /* bits per pixel (depth * channels) */
792 typedef png_row_info FAR * png_row_infop;
793 typedef png_row_info FAR * FAR * png_row_infopp;
795 /* These are the function types for the I/O functions and for the functions
796 * that allow the user to override the default I/O functions with his or her
797 * own. The png_error_ptr type should match that of user-supplied warning
798 * and error functions, while the png_rw_ptr type should match that of the
799 * user read/write data functions. Note that the 'write' function must not
800 * modify the buffer it is passed. The 'read' function, on the other hand, is
801 * expected to return the read data in the buffer.
803 typedef struct png_struct_def png_struct;
804 typedef PNG_CONST png_struct FAR * png_const_structp;
805 typedef png_struct FAR * png_structp;
807 typedef PNG_CALLBACK(void, *png_error_ptr, (png_structp, png_const_charp));
808 typedef PNG_CALLBACK(void, *png_rw_ptr, (png_structp, png_bytep, png_size_t));
809 typedef PNG_CALLBACK(void, *png_flush_ptr, (png_structp));
810 typedef PNG_CALLBACK(void, *png_read_status_ptr, (png_structp, png_uint_32,
812 typedef PNG_CALLBACK(void, *png_write_status_ptr, (png_structp, png_uint_32,
815 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
816 typedef PNG_CALLBACK(void, *png_progressive_info_ptr, (png_structp, png_infop));
817 typedef PNG_CALLBACK(void, *png_progressive_end_ptr, (png_structp, png_infop));
819 /* The following callback receives png_uint_32 row_number, int pass for the
820 * png_bytep data of the row. When transforming an interlaced image the
821 * row number is the row number within the sub-image of the interlace pass, so
822 * the value will increase to the height of the sub-image (not the full image)
823 * then reset to 0 for the next pass.
825 * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
826 * find the output pixel (x,y) given an interlaced sub-image pixel
827 * (row,col,pass). (See below for these macros.)
829 typedef PNG_CALLBACK(void, *png_progressive_row_ptr, (png_structp, png_bytep,
833 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
834 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
835 typedef PNG_CALLBACK(void, *png_user_transform_ptr, (png_structp, png_row_infop,
839 #ifdef PNG_USER_CHUNKS_SUPPORTED
840 typedef PNG_CALLBACK(int, *png_user_chunk_ptr, (png_structp,
841 png_unknown_chunkp));
843 #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
844 typedef PNG_CALLBACK(void, *png_unknown_chunk_ptr, (png_structp));
847 #ifdef PNG_SETJMP_SUPPORTED
848 /* This must match the function definition in <setjmp.h>, and the
849 * application must include this before png.h to obtain the definition
850 * of jmp_buf. The function is required to be PNG_NORETURN. (Note that
851 * PNG_PTR_NORETURN is used here because current versions of the Microsoft
852 * C compiler do not support the PNG_NORETURN attribute on a pointer.)
854 * If you get a type warning from the compiler when linking against this line
855 * then your compiler has 'longjmp' that does not match the requirements of the
856 * compiler that built libpng. You will have to write a wrapper function for
857 * your compiler's longjmp and call png_set_longjmp_fn directly (not via the
860 * If you get a warning here while building the library you will need to make
861 * changes to ensure that pnglibconf.h records the calling convention used by
862 * your compiler. This may be very difficult - try using a different compiler
863 * to build the library!
865 typedef PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)),
869 /* Transform masks for the high-level interface */
870 #define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */
871 #define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */
872 #define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */
873 #define PNG_TRANSFORM_PACKING 0x0004 /* read and write */
874 #define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */
875 #define PNG_TRANSFORM_EXPAND 0x0010 /* read only */
876 #define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */
877 #define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */
878 #define PNG_TRANSFORM_BGR 0x0080 /* read and write */
879 #define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */
880 #define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */
881 #define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */
882 #define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* write only */
883 /* Added to libpng-1.2.34 */
884 #define PNG_TRANSFORM_STRIP_FILLER_BEFORE PNG_TRANSFORM_STRIP_FILLER
885 #define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */
886 /* Added to libpng-1.4.0 */
887 #define PNG_TRANSFORM_GRAY_TO_RGB 0x2000 /* read only */
889 /* Flags for MNG supported features */
890 #define PNG_FLAG_MNG_EMPTY_PLTE 0x01
891 #define PNG_FLAG_MNG_FILTER_64 0x04
892 #define PNG_ALL_MNG_FEATURES 0x05
894 /* NOTE: prior to 1.5 these functions had no 'API' style declaration,
895 * this allowed the zlib default functions to be used on Windows
896 * platforms. In 1.5 the zlib default malloc (which just calls malloc and
897 * ignores the first argument) should be completely compatible with the
900 typedef PNG_CALLBACK(png_voidp, *png_malloc_ptr, (png_structp,
902 typedef PNG_CALLBACK(void, *png_free_ptr, (png_structp, png_voidp));
904 typedef png_struct FAR * FAR * png_structpp;
906 /* Section 3: exported functions
907 * Here are the function definitions most commonly used. This is not
908 * the place to find out how to use libpng. See libpng-manual.txt for the
909 * full explanation, see example.c for the summary. This just provides
910 * a simple one line description of the use of each function.
912 * The PNG_EXPORT() and PNG_EXPORTA() macros used below are defined in
913 * pngconf.h and in the *.dfn files in the scripts directory.
915 * PNG_EXPORT(ordinal, type, name, (args));
917 * ordinal: ordinal that is used while building
918 * *.def files. The ordinal value is only
919 * relevant when preprocessing png.h with
920 * the *.dfn files for building symbol table
921 * entries, and are removed by pngconf.h.
922 * type: return type of the function
923 * name: function name
924 * args: function arguments, with types
926 * When we wish to append attributes to a function prototype we use
927 * the PNG_EXPORTA() macro instead.
929 * PNG_EXPORTA(ordinal, type, name, (args), attributes);
931 * ordinal, type, name, and args: same as in PNG_EXPORT().
932 * attributes: function attributes
935 /* Returns the version number of the library */
936 PNG_EXPORT(1, png_uint_32, png_access_version_number, (void));
938 /* Tell lib we have already handled the first <num_bytes> magic bytes.
939 * Handling more than 8 bytes from the beginning of the file is an error.
941 PNG_EXPORT(2, void, png_set_sig_bytes, (png_structp png_ptr, int num_bytes));
943 /* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
944 * PNG file. Returns zero if the supplied bytes match the 8-byte PNG
945 * signature, and non-zero otherwise. Having num_to_check == 0 or
946 * start > 7 will always fail (ie return non-zero).
948 PNG_EXPORT(3, int, png_sig_cmp, (png_const_bytep sig, png_size_t start,
949 png_size_t num_to_check));
951 /* Simple signature checking function. This is the same as calling
952 * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n).
954 #define png_check_sig(sig, n) !png_sig_cmp((sig), 0, (n))
956 /* Allocate and initialize png_ptr struct for reading, and any other memory. */
957 PNG_EXPORTA(4, png_structp, png_create_read_struct,
958 (png_const_charp user_png_ver, png_voidp error_ptr,
959 png_error_ptr error_fn, png_error_ptr warn_fn),
962 /* Allocate and initialize png_ptr struct for writing, and any other memory */
963 PNG_EXPORTA(5, png_structp, png_create_write_struct,
964 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
965 png_error_ptr warn_fn),
968 PNG_EXPORT(6, png_size_t, png_get_compression_buffer_size,
969 (png_const_structp png_ptr));
971 PNG_EXPORT(7, void, png_set_compression_buffer_size, (png_structp png_ptr,
974 /* Moved from pngconf.h in 1.4.0 and modified to ensure setjmp/longjmp
977 #ifdef PNG_SETJMP_SUPPORTED
978 /* This function returns the jmp_buf built in to *png_ptr. It must be
979 * supplied with an appropriate 'longjmp' function to use on that jmp_buf
980 * unless the default error function is overridden in which case NULL is
981 * acceptable. The size of the jmp_buf is checked against the actual size
982 * allocated by the library - the call will return NULL on a mismatch
983 * indicating an ABI mismatch.
985 PNG_EXPORT(8, jmp_buf*, png_set_longjmp_fn, (png_structp png_ptr,
986 png_longjmp_ptr longjmp_fn, size_t jmp_buf_size));
987 # define png_jmpbuf(png_ptr) \
988 (*png_set_longjmp_fn((png_ptr), longjmp, sizeof (jmp_buf)))
990 # define png_jmpbuf(png_ptr) \
991 (LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP)
993 /* This function should be used by libpng applications in place of
994 * longjmp(png_ptr->jmpbuf, val). If longjmp_fn() has been set, it
995 * will use it; otherwise it will call PNG_ABORT(). This function was
996 * added in libpng-1.5.0.
998 PNG_EXPORTA(9, void, png_longjmp, (png_structp png_ptr, int val),
1001 #ifdef PNG_READ_SUPPORTED
1002 /* Reset the compression stream */
1003 PNG_EXPORT(10, int, png_reset_zstream, (png_structp png_ptr));
1006 /* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */
1007 #ifdef PNG_USER_MEM_SUPPORTED
1008 PNG_EXPORTA(11, png_structp, png_create_read_struct_2,
1009 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
1010 png_error_ptr warn_fn,
1011 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn),
1013 PNG_EXPORTA(12, png_structp, png_create_write_struct_2,
1014 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
1015 png_error_ptr warn_fn,
1016 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn),
1020 /* Write the PNG file signature. */
1021 PNG_EXPORT(13, void, png_write_sig, (png_structp png_ptr));
1023 /* Write a PNG chunk - size, type, (optional) data, CRC. */
1024 PNG_EXPORT(14, void, png_write_chunk, (png_structp png_ptr, png_const_bytep
1025 chunk_name, png_const_bytep data, png_size_t length));
1027 /* Write the start of a PNG chunk - length and chunk name. */
1028 PNG_EXPORT(15, void, png_write_chunk_start, (png_structp png_ptr,
1029 png_const_bytep chunk_name, png_uint_32 length));
1031 /* Write the data of a PNG chunk started with png_write_chunk_start(). */
1032 PNG_EXPORT(16, void, png_write_chunk_data, (png_structp png_ptr,
1033 png_const_bytep data, png_size_t length));
1035 /* Finish a chunk started with png_write_chunk_start() (includes CRC). */
1036 PNG_EXPORT(17, void, png_write_chunk_end, (png_structp png_ptr));
1038 /* Allocate and initialize the info structure */
1039 PNG_EXPORTA(18, png_infop, png_create_info_struct, (png_structp png_ptr),
1042 PNG_EXPORT(19, void, png_info_init_3, (png_infopp info_ptr,
1043 png_size_t png_info_struct_size));
1045 /* Writes all the PNG information before the image. */
1046 PNG_EXPORT(20, void, png_write_info_before_PLTE,
1047 (png_structp png_ptr, png_infop info_ptr));
1048 PNG_EXPORT(21, void, png_write_info,
1049 (png_structp png_ptr, png_infop info_ptr));
1051 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1052 /* Read the information before the actual image data. */
1053 PNG_EXPORT(22, void, png_read_info,
1054 (png_structp png_ptr, png_infop info_ptr));
1057 #ifdef PNG_TIME_RFC1123_SUPPORTED
1058 PNG_EXPORT(23, png_const_charp, png_convert_to_rfc1123,
1059 (png_structp png_ptr,
1060 png_const_timep ptime));
1063 #ifdef PNG_CONVERT_tIME_SUPPORTED
1064 /* Convert from a struct tm to png_time */
1065 PNG_EXPORT(24, void, png_convert_from_struct_tm, (png_timep ptime,
1066 PNG_CONST struct tm FAR * ttime));
1068 /* Convert from time_t to png_time. Uses gmtime() */
1069 PNG_EXPORT(25, void, png_convert_from_time_t,
1070 (png_timep ptime, time_t ttime));
1071 #endif /* PNG_CONVERT_tIME_SUPPORTED */
1073 #ifdef PNG_READ_EXPAND_SUPPORTED
1074 /* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
1075 PNG_EXPORT(26, void, png_set_expand, (png_structp png_ptr));
1076 PNG_EXPORT(27, void, png_set_expand_gray_1_2_4_to_8, (png_structp png_ptr));
1077 PNG_EXPORT(28, void, png_set_palette_to_rgb, (png_structp png_ptr));
1078 PNG_EXPORT(29, void, png_set_tRNS_to_alpha, (png_structp png_ptr));
1081 #ifdef PNG_READ_EXPAND_16_SUPPORTED
1082 /* Expand to 16 bit channels, forces conversion of palette to RGB and expansion
1083 * of a tRNS chunk if present.
1085 PNG_EXPORT(221, void, png_set_expand_16, (png_structp png_ptr));
1088 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
1089 /* Use blue, green, red order for pixels. */
1090 PNG_EXPORT(30, void, png_set_bgr, (png_structp png_ptr));
1093 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
1094 /* Expand the grayscale to 24-bit RGB if necessary. */
1095 PNG_EXPORT(31, void, png_set_gray_to_rgb, (png_structp png_ptr));
1098 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1099 /* Reduce RGB to grayscale. */
1100 PNG_FP_EXPORT(32, void, png_set_rgb_to_gray, (png_structp png_ptr,
1101 int error_action, double red, double green));
1102 PNG_FIXED_EXPORT(33, void, png_set_rgb_to_gray_fixed, (png_structp png_ptr,
1103 int error_action, png_fixed_point red, png_fixed_point green));
1105 PNG_EXPORT(34, png_byte, png_get_rgb_to_gray_status, (png_const_structp
1109 PNG_EXPORT(35, void, png_build_grayscale_palette, (int bit_depth,
1110 png_colorp palette));
1112 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
1113 PNG_EXPORT(36, void, png_set_strip_alpha, (png_structp png_ptr));
1116 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
1117 defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
1118 PNG_EXPORT(37, void, png_set_swap_alpha, (png_structp png_ptr));
1121 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
1122 defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
1123 PNG_EXPORT(38, void, png_set_invert_alpha, (png_structp png_ptr));
1126 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
1127 /* Add a filler byte to 8-bit Gray or 24-bit RGB images. */
1128 PNG_EXPORT(39, void, png_set_filler, (png_structp png_ptr, png_uint_32 filler,
1130 /* The values of the PNG_FILLER_ defines should NOT be changed */
1131 # define PNG_FILLER_BEFORE 0
1132 # define PNG_FILLER_AFTER 1
1133 /* Add an alpha byte to 8-bit Gray or 24-bit RGB images. */
1134 PNG_EXPORT(40, void, png_set_add_alpha,
1135 (png_structp png_ptr, png_uint_32 filler,
1137 #endif /* PNG_READ_FILLER_SUPPORTED || PNG_WRITE_FILLER_SUPPORTED */
1139 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
1140 /* Swap bytes in 16-bit depth files. */
1141 PNG_EXPORT(41, void, png_set_swap, (png_structp png_ptr));
1144 #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
1145 /* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
1146 PNG_EXPORT(42, void, png_set_packing, (png_structp png_ptr));
1149 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
1150 defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1151 /* Swap packing order of pixels in bytes. */
1152 PNG_EXPORT(43, void, png_set_packswap, (png_structp png_ptr));
1155 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
1156 /* Converts files to legal bit depths. */
1157 PNG_EXPORT(44, void, png_set_shift, (png_structp png_ptr, png_const_color_8p
1161 #if defined(PNG_READ_INTERLACING_SUPPORTED) || \
1162 defined(PNG_WRITE_INTERLACING_SUPPORTED)
1163 /* Have the code handle the interlacing. Returns the number of passes.
1164 * MUST be called before png_read_update_info or png_start_read_image,
1165 * otherwise it will not have the desired effect. Note that it is still
1166 * necessary to call png_read_row or png_read_rows png_get_image_height
1167 * times for each pass.
1169 PNG_EXPORT(45, int, png_set_interlace_handling, (png_structp png_ptr));
1172 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
1173 /* Invert monochrome files */
1174 PNG_EXPORT(46, void, png_set_invert_mono, (png_structp png_ptr));
1177 #ifdef PNG_READ_BACKGROUND_SUPPORTED
1178 /* Handle alpha and tRNS by replacing with a background color. */
1179 PNG_FP_EXPORT(47, void, png_set_background, (png_structp png_ptr,
1180 png_const_color_16p background_color, int background_gamma_code,
1181 int need_expand, double background_gamma));
1182 PNG_FIXED_EXPORT(215, void, png_set_background_fixed, (png_structp png_ptr,
1183 png_const_color_16p background_color, int background_gamma_code,
1184 int need_expand, png_fixed_point background_gamma));
1186 #ifdef PNG_READ_BACKGROUND_SUPPORTED
1187 # define PNG_BACKGROUND_GAMMA_UNKNOWN 0
1188 # define PNG_BACKGROUND_GAMMA_SCREEN 1
1189 # define PNG_BACKGROUND_GAMMA_FILE 2
1190 # define PNG_BACKGROUND_GAMMA_UNIQUE 3
1193 #ifdef PNG_READ_16_TO_8_SUPPORTED
1194 /* Strip the second byte of information from a 16-bit depth file. */
1195 PNG_EXPORT(48, void, png_set_strip_16, (png_structp png_ptr));
1198 #ifdef PNG_READ_QUANTIZE_SUPPORTED
1199 /* Turn on quantizing, and reduce the palette to the number of colors
1202 PNG_EXPORT(49, void, png_set_quantize,
1203 (png_structp png_ptr, png_colorp palette,
1204 int num_palette, int maximum_colors, png_const_uint_16p histogram,
1205 int full_quantize));
1208 #ifdef PNG_READ_GAMMA_SUPPORTED
1209 /* The threshold on gamma processing is configurable but hard-wired into the
1210 * library. The following is the floating point variant.
1212 #define PNG_GAMMA_THRESHOLD (PNG_GAMMA_THRESHOLD_FIXED*.00001)
1214 /* Handle gamma correction. Screen_gamma=(display_exponent) */
1215 PNG_FP_EXPORT(50, void, png_set_gamma,
1216 (png_structp png_ptr, double screen_gamma,
1217 double default_file_gamma));
1218 PNG_FIXED_EXPORT(208, void, png_set_gamma_fixed, (png_structp png_ptr,
1219 png_fixed_point screen_gamma, png_fixed_point default_file_gamma));
1222 #ifdef PNG_WRITE_FLUSH_SUPPORTED
1223 /* Set how many lines between output flushes - 0 for no flushing */
1224 PNG_EXPORT(51, void, png_set_flush, (png_structp png_ptr, int nrows));
1225 /* Flush the current PNG output buffer */
1226 PNG_EXPORT(52, void, png_write_flush, (png_structp png_ptr));
1229 /* Optional update palette with requested transformations */
1230 PNG_EXPORT(53, void, png_start_read_image, (png_structp png_ptr));
1232 /* Optional call to update the users info structure */
1233 PNG_EXPORT(54, void, png_read_update_info,
1234 (png_structp png_ptr, png_infop info_ptr));
1236 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1237 /* Read one or more rows of image data. */
1238 PNG_EXPORT(55, void, png_read_rows, (png_structp png_ptr, png_bytepp row,
1239 png_bytepp display_row, png_uint_32 num_rows));
1242 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1243 /* Read a row of data. */
1244 PNG_EXPORT(56, void, png_read_row, (png_structp png_ptr, png_bytep row,
1245 png_bytep display_row));
1248 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1249 /* Read the whole image into memory at once. */
1250 PNG_EXPORT(57, void, png_read_image, (png_structp png_ptr, png_bytepp image));
1253 /* Write a row of image data */
1254 PNG_EXPORT(58, void, png_write_row,
1255 (png_structp png_ptr, png_const_bytep row));
1257 /* Write a few rows of image data: (*row) is not written; however, the type
1258 * is declared as writeable to maintain compatibility with previous versions
1259 * of libpng and to allow the 'display_row' array from read_rows to be passed
1260 * unchanged to write_rows.
1262 PNG_EXPORT(59, void, png_write_rows, (png_structp png_ptr, png_bytepp row,
1263 png_uint_32 num_rows));
1265 /* Write the image data */
1266 PNG_EXPORT(60, void, png_write_image,
1267 (png_structp png_ptr, png_bytepp image));
1269 /* Write the end of the PNG file. */
1270 PNG_EXPORT(61, void, png_write_end,
1271 (png_structp png_ptr, png_infop info_ptr));
1273 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1274 /* Read the end of the PNG file. */
1275 PNG_EXPORT(62, void, png_read_end, (png_structp png_ptr, png_infop info_ptr));
1278 /* Free any memory associated with the png_info_struct */
1279 PNG_EXPORT(63, void, png_destroy_info_struct, (png_structp png_ptr,
1280 png_infopp info_ptr_ptr));
1282 /* Free any memory associated with the png_struct and the png_info_structs */
1283 PNG_EXPORT(64, void, png_destroy_read_struct, (png_structpp png_ptr_ptr,
1284 png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr));
1286 /* Free any memory associated with the png_struct and the png_info_structs */
1287 PNG_EXPORT(65, void, png_destroy_write_struct, (png_structpp png_ptr_ptr,
1288 png_infopp info_ptr_ptr));
1290 /* Set the libpng method of handling chunk CRC errors */
1291 PNG_EXPORT(66, void, png_set_crc_action,
1292 (png_structp png_ptr, int crit_action, int ancil_action));
1294 /* Values for png_set_crc_action() say how to handle CRC errors in
1295 * ancillary and critical chunks, and whether to use the data contained
1296 * therein. Note that it is impossible to "discard" data in a critical
1297 * chunk. For versions prior to 0.90, the action was always error/quit,
1298 * whereas in version 0.90 and later, the action for CRC errors in ancillary
1299 * chunks is warn/discard. These values should NOT be changed.
1301 * value action:critical action:ancillary
1303 #define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */
1304 #define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */
1305 #define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */
1306 #define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */
1307 #define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */
1308 #define PNG_CRC_NO_CHANGE 5 /* use current value use current value */
1310 /* These functions give the user control over the scan-line filtering in
1311 * libpng and the compression methods used by zlib. These functions are
1312 * mainly useful for testing, as the defaults should work with most users.
1313 * Those users who are tight on memory or want faster performance at the
1314 * expense of compression can modify them. See the compression library
1315 * header file (zlib.h) for an explination of the compression functions.
1318 /* Set the filtering method(s) used by libpng. Currently, the only valid
1319 * value for "method" is 0.
1321 PNG_EXPORT(67, void, png_set_filter,
1322 (png_structp png_ptr, int method, int filters));
1324 /* Flags for png_set_filter() to say which filters to use. The flags
1325 * are chosen so that they don't conflict with real filter types
1326 * below, in case they are supplied instead of the #defined constants.
1327 * These values should NOT be changed.
1329 #define PNG_NO_FILTERS 0x00
1330 #define PNG_FILTER_NONE 0x08
1331 #define PNG_FILTER_SUB 0x10
1332 #define PNG_FILTER_UP 0x20
1333 #define PNG_FILTER_AVG 0x40
1334 #define PNG_FILTER_PAETH 0x80
1335 #define PNG_ALL_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP | \
1336 PNG_FILTER_AVG | PNG_FILTER_PAETH)
1338 /* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
1339 * These defines should NOT be changed.
1341 #define PNG_FILTER_VALUE_NONE 0
1342 #define PNG_FILTER_VALUE_SUB 1
1343 #define PNG_FILTER_VALUE_UP 2
1344 #define PNG_FILTER_VALUE_AVG 3
1345 #define PNG_FILTER_VALUE_PAETH 4
1346 #define PNG_FILTER_VALUE_LAST 5
1348 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* EXPERIMENTAL */
1349 /* The "heuristic_method" is given by one of the PNG_FILTER_HEURISTIC_
1350 * defines, either the default (minimum-sum-of-absolute-differences), or
1351 * the experimental method (weighted-minimum-sum-of-absolute-differences).
1353 * Weights are factors >= 1.0, indicating how important it is to keep the
1354 * filter type consistent between rows. Larger numbers mean the current
1355 * filter is that many times as likely to be the same as the "num_weights"
1356 * previous filters. This is cumulative for each previous row with a weight.
1357 * There needs to be "num_weights" values in "filter_weights", or it can be
1358 * NULL if the weights aren't being specified. Weights have no influence on
1359 * the selection of the first row filter. Well chosen weights can (in theory)
1360 * improve the compression for a given image.
1362 * Costs are factors >= 1.0 indicating the relative decoding costs of a
1363 * filter type. Higher costs indicate more decoding expense, and are
1364 * therefore less likely to be selected over a filter with lower computational
1365 * costs. There needs to be a value in "filter_costs" for each valid filter
1366 * type (given by PNG_FILTER_VALUE_LAST), or it can be NULL if you aren't
1367 * setting the costs. Costs try to improve the speed of decompression without
1368 * unduly increasing the compressed image size.
1370 * A negative weight or cost indicates the default value is to be used, and
1371 * values in the range [0.0, 1.0) indicate the value is to remain unchanged.
1372 * The default values for both weights and costs are currently 1.0, but may
1373 * change if good general weighting/cost heuristics can be found. If both
1374 * the weights and costs are set to 1.0, this degenerates the WEIGHTED method
1375 * to the UNWEIGHTED method, but with added encoding time/computation.
1377 PNG_FP_EXPORT(68, void, png_set_filter_heuristics, (png_structp png_ptr,
1378 int heuristic_method, int num_weights, png_const_doublep filter_weights,
1379 png_const_doublep filter_costs));
1380 PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed,
1381 (png_structp png_ptr,
1382 int heuristic_method, int num_weights, png_const_fixed_point_p
1383 filter_weights, png_const_fixed_point_p filter_costs));
1384 #endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
1386 /* Heuristic used for row filter selection. These defines should NOT be
1389 #define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */
1390 #define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */
1391 #define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */
1392 #define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */
1394 /* Set the library compression level. Currently, valid values range from
1395 * 0 - 9, corresponding directly to the zlib compression levels 0 - 9
1396 * (0 - no compression, 9 - "maximal" compression). Note that tests have
1397 * shown that zlib compression levels 3-6 usually perform as well as level 9
1398 * for PNG images, and do considerably fewer caclulations. In the future,
1399 * these values may not correspond directly to the zlib compression levels.
1401 PNG_EXPORT(69, void, png_set_compression_level,
1402 (png_structp png_ptr, int level));
1404 PNG_EXPORT(70, void, png_set_compression_mem_level, (png_structp png_ptr,
1407 PNG_EXPORT(71, void, png_set_compression_strategy, (png_structp png_ptr,
1410 PNG_EXPORT(72, void, png_set_compression_window_bits, (png_structp png_ptr,
1413 PNG_EXPORT(73, void, png_set_compression_method, (png_structp png_ptr,
1416 /* These next functions are called for input/output, memory, and error
1417 * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c,
1418 * and call standard C I/O routines such as fread(), fwrite(), and
1419 * fprintf(). These functions can be made to use other I/O routines
1420 * at run time for those applications that need to handle I/O in a
1421 * different manner by calling png_set_???_fn(). See libpng-manual.txt for
1425 #ifdef PNG_STDIO_SUPPORTED
1426 /* Initialize the input/output for the PNG file to the default functions. */
1427 PNG_EXPORT(74, void, png_init_io, (png_structp png_ptr, png_FILE_p fp));
1430 /* Replace the (error and abort), and warning functions with user
1431 * supplied functions. If no messages are to be printed you must still
1432 * write and use replacement functions. The replacement error_fn should
1433 * still do a longjmp to the last setjmp location if you are using this
1434 * method of error handling. If error_fn or warning_fn is NULL, the
1435 * default function will be used.
1438 PNG_EXPORT(75, void, png_set_error_fn,
1439 (png_structp png_ptr, png_voidp error_ptr,
1440 png_error_ptr error_fn, png_error_ptr warning_fn));
1442 /* Return the user pointer associated with the error functions */
1443 PNG_EXPORT(76, png_voidp, png_get_error_ptr, (png_const_structp png_ptr));
1445 /* Replace the default data output functions with a user supplied one(s).
1446 * If buffered output is not used, then output_flush_fn can be set to NULL.
1447 * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time
1448 * output_flush_fn will be ignored (and thus can be NULL).
1449 * It is probably a mistake to use NULL for output_flush_fn if
1450 * write_data_fn is not also NULL unless you have built libpng with
1451 * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's
1452 * default flush function, which uses the standard *FILE structure, will
1455 PNG_EXPORT(77, void, png_set_write_fn, (png_structp png_ptr, png_voidp io_ptr,
1456 png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn));
1458 /* Replace the default data input function with a user supplied one. */
1459 PNG_EXPORT(78, void, png_set_read_fn, (png_structp png_ptr, png_voidp io_ptr,
1460 png_rw_ptr read_data_fn));
1462 /* Return the user pointer associated with the I/O functions */
1463 PNG_EXPORT(79, png_voidp, png_get_io_ptr, (png_structp png_ptr));
1465 PNG_EXPORT(80, void, png_set_read_status_fn, (png_structp png_ptr,
1466 png_read_status_ptr read_row_fn));
1468 PNG_EXPORT(81, void, png_set_write_status_fn, (png_structp png_ptr,
1469 png_write_status_ptr write_row_fn));
1471 #ifdef PNG_USER_MEM_SUPPORTED
1472 /* Replace the default memory allocation functions with user supplied one(s). */
1473 PNG_EXPORT(82, void, png_set_mem_fn, (png_structp png_ptr, png_voidp mem_ptr,
1474 png_malloc_ptr malloc_fn, png_free_ptr free_fn));
1475 /* Return the user pointer associated with the memory functions */
1476 PNG_EXPORT(83, png_voidp, png_get_mem_ptr, (png_const_structp png_ptr));
1479 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
1480 PNG_EXPORT(84, void, png_set_read_user_transform_fn, (png_structp png_ptr,
1481 png_user_transform_ptr read_user_transform_fn));
1484 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
1485 PNG_EXPORT(85, void, png_set_write_user_transform_fn, (png_structp png_ptr,
1486 png_user_transform_ptr write_user_transform_fn));
1489 #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
1490 PNG_EXPORT(86, void, png_set_user_transform_info, (png_structp png_ptr,
1491 png_voidp user_transform_ptr, int user_transform_depth,
1492 int user_transform_channels));
1493 /* Return the user pointer associated with the user transform functions */
1494 PNG_EXPORT(87, png_voidp, png_get_user_transform_ptr,
1495 (png_const_structp png_ptr));
1498 #ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED
1499 /* Return information about the row currently being processed. Note that these
1500 * APIs do not fail but will return unexpected results if called outside a user
1501 * transform callback. Also note that when transforming an interlaced image the
1502 * row number is the row number within the sub-image of the interlace pass, so
1503 * the value will increase to the height of the sub-image (not the full image)
1504 * then reset to 0 for the next pass.
1506 * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
1507 * find the output pixel (x,y) given an interlaced sub-image pixel
1508 * (row,col,pass). (See below for these macros.)
1510 PNG_EXPORT(217, png_uint_32, png_get_current_row_number, (png_const_structp));
1511 PNG_EXPORT(218, png_byte, png_get_current_pass_number, (png_const_structp));
1514 #ifdef PNG_USER_CHUNKS_SUPPORTED
1515 PNG_EXPORT(88, void, png_set_read_user_chunk_fn, (png_structp png_ptr,
1516 png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));
1517 PNG_EXPORT(89, png_voidp, png_get_user_chunk_ptr, (png_const_structp png_ptr));
1520 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1521 /* Sets the function callbacks for the push reader, and a pointer to a
1522 * user-defined structure available to the callback functions.
1524 PNG_EXPORT(90, void, png_set_progressive_read_fn, (png_structp png_ptr,
1525 png_voidp progressive_ptr, png_progressive_info_ptr info_fn,
1526 png_progressive_row_ptr row_fn, png_progressive_end_ptr end_fn));
1528 /* Returns the user pointer associated with the push read functions */
1529 PNG_EXPORT(91, png_voidp, png_get_progressive_ptr, (png_const_structp png_ptr));
1531 /* Function to be called when data becomes available */
1532 PNG_EXPORT(92, void, png_process_data,
1533 (png_structp png_ptr, png_infop info_ptr,
1534 png_bytep buffer, png_size_t buffer_size));
1536 /* A function which may be called *only* within png_process_data to stop the
1537 * processing of any more data. The function returns the number of bytes
1538 * remaining, excluding any that libpng has cached internally. A subsequent
1539 * call to png_process_data must supply these bytes again. If the argument
1540 * 'save' is set to true the routine will first save all the pending data and
1541 * will always return 0.
1543 PNG_EXPORT(219, png_size_t, png_process_data_pause, (png_structp, int save));
1545 /* A function which may be called *only* outside (after) a call to
1546 * png_process_data. It returns the number of bytes of data to skip in the
1547 * input. Normally it will return 0, but if it returns a non-zero value the
1548 * application must skip than number of bytes of input data and pass the
1549 * following data to the next call to png_process_data.
1551 PNG_EXPORT(220, png_uint_32, png_process_data_skip, (png_structp));
1553 /* Function that combines rows. 'new_row' is a flag that should come from
1554 * the callback and be non-NULL if anything needs to be done; the library
1555 * stores its own version of the new data internally and ignores the passed
1558 PNG_EXPORT(93, void, png_progressive_combine_row, (png_structp png_ptr,
1559 png_bytep old_row, png_const_bytep new_row));
1560 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
1562 PNG_EXPORTA(94, png_voidp, png_malloc,
1563 (png_structp png_ptr, png_alloc_size_t size),
1565 /* Added at libpng version 1.4.0 */
1566 PNG_EXPORTA(95, png_voidp, png_calloc,
1567 (png_structp png_ptr, png_alloc_size_t size),
1570 /* Added at libpng version 1.2.4 */
1571 PNG_EXPORTA(96, png_voidp, png_malloc_warn, (png_structp png_ptr,
1572 png_alloc_size_t size), PNG_ALLOCATED);
1574 /* Frees a pointer allocated by png_malloc() */
1575 PNG_EXPORT(97, void, png_free, (png_structp png_ptr, png_voidp ptr));
1577 /* Free data that was allocated internally */
1578 PNG_EXPORT(98, void, png_free_data,
1579 (png_structp png_ptr, png_infop info_ptr, png_uint_32 free_me, int num));
1581 /* Reassign responsibility for freeing existing data, whether allocated
1582 * by libpng or by the application */
1583 PNG_EXPORT(99, void, png_data_freer,
1584 (png_structp png_ptr, png_infop info_ptr, int freer, png_uint_32 mask));
1586 /* Assignments for png_data_freer */
1587 #define PNG_DESTROY_WILL_FREE_DATA 1
1588 #define PNG_SET_WILL_FREE_DATA 1
1589 #define PNG_USER_WILL_FREE_DATA 2
1590 /* Flags for png_ptr->free_me and info_ptr->free_me */
1591 #define PNG_FREE_HIST 0x0008
1592 #define PNG_FREE_ICCP 0x0010
1593 #define PNG_FREE_SPLT 0x0020
1594 #define PNG_FREE_ROWS 0x0040
1595 #define PNG_FREE_PCAL 0x0080
1596 #define PNG_FREE_SCAL 0x0100
1597 #define PNG_FREE_UNKN 0x0200
1598 #define PNG_FREE_LIST 0x0400
1599 #define PNG_FREE_PLTE 0x1000
1600 #define PNG_FREE_TRNS 0x2000
1601 #define PNG_FREE_TEXT 0x4000
1602 #define PNG_FREE_ALL 0x7fff
1603 #define PNG_FREE_MUL 0x4220 /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */
1605 #ifdef PNG_USER_MEM_SUPPORTED
1606 PNG_EXPORTA(100, png_voidp, png_malloc_default, (png_structp png_ptr,
1607 png_alloc_size_t size), PNG_ALLOCATED);
1608 PNG_EXPORT(101, void, png_free_default, (png_structp png_ptr, png_voidp ptr));
1611 #ifdef PNG_ERROR_TEXT_SUPPORTED
1612 /* Fatal error in PNG image of libpng - can't continue */
1613 PNG_EXPORTA(102, void, png_error,
1614 (png_structp png_ptr, png_const_charp error_message),
1617 /* The same, but the chunk name is prepended to the error string. */
1618 PNG_EXPORTA(103, void, png_chunk_error, (png_structp png_ptr,
1619 png_const_charp error_message), PNG_NORETURN);
1622 /* Fatal error in PNG image of libpng - can't continue */
1623 PNG_EXPORTA(104, void, png_err, (png_structp png_ptr), PNG_NORETURN);
1626 /* Non-fatal error in libpng. Can continue, but may have a problem. */
1627 PNG_EXPORT(105, void, png_warning, (png_structp png_ptr,
1628 png_const_charp warning_message));
1630 /* Non-fatal error in libpng, chunk name is prepended to message. */
1631 PNG_EXPORT(106, void, png_chunk_warning, (png_structp png_ptr,
1632 png_const_charp warning_message));
1634 #ifdef PNG_BENIGN_ERRORS_SUPPORTED
1635 /* Benign error in libpng. Can continue, but may have a problem.
1636 * User can choose whether to handle as a fatal error or as a warning. */
1637 # undef png_benign_error
1638 PNG_EXPORT(107, void, png_benign_error, (png_structp png_ptr,
1639 png_const_charp warning_message));
1641 /* Same, chunk name is prepended to message. */
1642 # undef png_chunk_benign_error
1643 PNG_EXPORT(108, void, png_chunk_benign_error, (png_structp png_ptr,
1644 png_const_charp warning_message));
1646 PNG_EXPORT(109, void, png_set_benign_errors,
1647 (png_structp png_ptr, int allowed));
1649 # ifdef PNG_ALLOW_BENIGN_ERRORS
1650 # define png_benign_error png_warning
1651 # define png_chunk_benign_error png_chunk_warning
1653 # define png_benign_error png_error
1654 # define png_chunk_benign_error png_chunk_error
1658 /* The png_set_<chunk> functions are for storing values in the png_info_struct.
1659 * Similarly, the png_get_<chunk> calls are used to read values from the
1660 * png_info_struct, either storing the parameters in the passed variables, or
1661 * setting pointers into the png_info_struct where the data is stored. The
1662 * png_get_<chunk> functions return a non-zero value if the data was available
1663 * in info_ptr, or return zero and do not change any of the parameters if the
1664 * data was not available.
1666 * These functions should be used instead of directly accessing png_info
1667 * to avoid problems with future changes in the size and internal layout of
1670 /* Returns "flag" if chunk data is valid in info_ptr. */
1671 PNG_EXPORT(110, png_uint_32, png_get_valid,
1672 (png_const_structp png_ptr, png_const_infop info_ptr,
1675 /* Returns number of bytes needed to hold a transformed row. */
1676 PNG_EXPORT(111, png_size_t, png_get_rowbytes, (png_const_structp png_ptr,
1677 png_const_infop info_ptr));
1679 #ifdef PNG_INFO_IMAGE_SUPPORTED
1680 /* Returns row_pointers, which is an array of pointers to scanlines that was
1681 * returned from png_read_png().
1683 PNG_EXPORT(112, png_bytepp, png_get_rows,
1684 (png_const_structp png_ptr, png_const_infop info_ptr));
1685 /* Set row_pointers, which is an array of pointers to scanlines for use
1686 * by png_write_png().
1688 PNG_EXPORT(113, void, png_set_rows, (png_structp png_ptr,
1689 png_infop info_ptr, png_bytepp row_pointers));
1692 /* Returns number of color channels in image. */
1693 PNG_EXPORT(114, png_byte, png_get_channels,
1694 (png_const_structp png_ptr, png_const_infop info_ptr));
1696 #ifdef PNG_EASY_ACCESS_SUPPORTED
1697 /* Returns image width in pixels. */
1698 PNG_EXPORT(115, png_uint_32, png_get_image_width, (png_const_structp png_ptr,
1699 png_const_infop info_ptr));
1701 /* Returns image height in pixels. */
1702 PNG_EXPORT(116, png_uint_32, png_get_image_height, (png_const_structp png_ptr,
1703 png_const_infop info_ptr));
1705 /* Returns image bit_depth. */
1706 PNG_EXPORT(117, png_byte, png_get_bit_depth,
1707 (png_const_structp png_ptr, png_const_infop info_ptr));
1709 /* Returns image color_type. */
1710 PNG_EXPORT(118, png_byte, png_get_color_type, (png_const_structp png_ptr,
1711 png_const_infop info_ptr));
1713 /* Returns image filter_type. */
1714 PNG_EXPORT(119, png_byte, png_get_filter_type, (png_const_structp png_ptr,
1715 png_const_infop info_ptr));
1717 /* Returns image interlace_type. */
1718 PNG_EXPORT(120, png_byte, png_get_interlace_type, (png_const_structp png_ptr,
1719 png_const_infop info_ptr));
1721 /* Returns image compression_type. */
1722 PNG_EXPORT(121, png_byte, png_get_compression_type, (png_const_structp png_ptr,
1723 png_const_infop info_ptr));
1725 /* Returns image resolution in pixels per meter, from pHYs chunk data. */
1726 PNG_EXPORT(122, png_uint_32, png_get_pixels_per_meter,
1727 (png_const_structp png_ptr, png_const_infop info_ptr));
1728 PNG_EXPORT(123, png_uint_32, png_get_x_pixels_per_meter,
1729 (png_const_structp png_ptr, png_const_infop info_ptr));
1730 PNG_EXPORT(124, png_uint_32, png_get_y_pixels_per_meter,
1731 (png_const_structp png_ptr, png_const_infop info_ptr));
1733 /* Returns pixel aspect ratio, computed from pHYs chunk data. */
1734 PNG_FP_EXPORT(125, float, png_get_pixel_aspect_ratio,
1735 (png_const_structp png_ptr, png_const_infop info_ptr));
1736 PNG_FIXED_EXPORT(210, png_fixed_point, png_get_pixel_aspect_ratio_fixed,
1737 (png_const_structp png_ptr, png_const_infop info_ptr));
1739 /* Returns image x, y offset in pixels or microns, from oFFs chunk data. */
1740 PNG_EXPORT(126, png_int_32, png_get_x_offset_pixels,
1741 (png_const_structp png_ptr, png_const_infop info_ptr));
1742 PNG_EXPORT(127, png_int_32, png_get_y_offset_pixels,
1743 (png_const_structp png_ptr, png_const_infop info_ptr));
1744 PNG_EXPORT(128, png_int_32, png_get_x_offset_microns,
1745 (png_const_structp png_ptr, png_const_infop info_ptr));
1746 PNG_EXPORT(129, png_int_32, png_get_y_offset_microns,
1747 (png_const_structp png_ptr, png_const_infop info_ptr));
1749 #endif /* PNG_EASY_ACCESS_SUPPORTED */
1751 /* Returns pointer to signature string read from PNG header */
1752 PNG_EXPORT(130, png_const_bytep, png_get_signature,
1753 (png_const_structp png_ptr, png_infop info_ptr));
1755 #ifdef PNG_bKGD_SUPPORTED
1756 PNG_EXPORT(131, png_uint_32, png_get_bKGD,
1757 (png_const_structp png_ptr, png_infop info_ptr,
1758 png_color_16p *background));
1761 #ifdef PNG_bKGD_SUPPORTED
1762 PNG_EXPORT(132, void, png_set_bKGD, (png_structp png_ptr, png_infop info_ptr,
1763 png_const_color_16p background));
1766 #ifdef PNG_cHRM_SUPPORTED
1767 PNG_FP_EXPORT(133, png_uint_32, png_get_cHRM, (png_const_structp png_ptr,
1768 png_const_infop info_ptr, double *white_x, double *white_y, double *red_x,
1769 double *red_y, double *green_x, double *green_y, double *blue_x,
1771 #ifdef PNG_FIXED_POINT_SUPPORTED /* Otherwise not implemented */
1772 PNG_FIXED_EXPORT(134, png_uint_32, png_get_cHRM_fixed,
1773 (png_const_structp png_ptr,
1774 png_const_infop info_ptr, png_fixed_point *int_white_x,
1775 png_fixed_point *int_white_y, png_fixed_point *int_red_x,
1776 png_fixed_point *int_red_y, png_fixed_point *int_green_x,
1777 png_fixed_point *int_green_y, png_fixed_point *int_blue_x,
1778 png_fixed_point *int_blue_y));
1782 #ifdef PNG_cHRM_SUPPORTED
1783 PNG_FP_EXPORT(135, void, png_set_cHRM,
1784 (png_structp png_ptr, png_infop info_ptr,
1785 double white_x, double white_y, double red_x, double red_y, double green_x,
1786 double green_y, double blue_x, double blue_y));
1787 PNG_FIXED_EXPORT(136, void, png_set_cHRM_fixed, (png_structp png_ptr,
1788 png_infop info_ptr, png_fixed_point int_white_x,
1789 png_fixed_point int_white_y, png_fixed_point int_red_x,
1790 png_fixed_point int_red_y, png_fixed_point int_green_x,
1791 png_fixed_point int_green_y, png_fixed_point int_blue_x,
1792 png_fixed_point int_blue_y));
1795 #ifdef PNG_gAMA_SUPPORTED
1796 PNG_FP_EXPORT(137, png_uint_32, png_get_gAMA,
1797 (png_const_structp png_ptr, png_const_infop info_ptr,
1798 double *file_gamma));
1799 PNG_FIXED_EXPORT(138, png_uint_32, png_get_gAMA_fixed,
1800 (png_const_structp png_ptr, png_const_infop info_ptr,
1801 png_fixed_point *int_file_gamma));
1804 #ifdef PNG_gAMA_SUPPORTED
1805 PNG_FP_EXPORT(139, void, png_set_gAMA, (png_structp png_ptr,
1806 png_infop info_ptr, double file_gamma));
1807 PNG_FIXED_EXPORT(140, void, png_set_gAMA_fixed, (png_structp png_ptr,
1808 png_infop info_ptr, png_fixed_point int_file_gamma));
1811 #ifdef PNG_hIST_SUPPORTED
1812 PNG_EXPORT(141, png_uint_32, png_get_hIST,
1813 (png_const_structp png_ptr, png_const_infop info_ptr,
1814 png_uint_16p *hist));
1817 #ifdef PNG_hIST_SUPPORTED
1818 PNG_EXPORT(142, void, png_set_hIST, (png_structp png_ptr,
1819 png_infop info_ptr, png_const_uint_16p hist));
1822 PNG_EXPORT(143, png_uint_32, png_get_IHDR,
1823 (png_structp png_ptr, png_infop info_ptr,
1824 png_uint_32 *width, png_uint_32 *height, int *bit_depth, int *color_type,
1825 int *interlace_method, int *compression_method, int *filter_method));
1827 PNG_EXPORT(144, void, png_set_IHDR,
1828 (png_structp png_ptr, png_infop info_ptr,
1829 png_uint_32 width, png_uint_32 height, int bit_depth, int color_type,
1830 int interlace_method, int compression_method, int filter_method));
1832 #ifdef PNG_oFFs_SUPPORTED
1833 PNG_EXPORT(145, png_uint_32, png_get_oFFs,
1834 (png_const_structp png_ptr, png_const_infop info_ptr,
1835 png_int_32 *offset_x, png_int_32 *offset_y, int *unit_type));
1838 #ifdef PNG_oFFs_SUPPORTED
1839 PNG_EXPORT(146, void, png_set_oFFs,
1840 (png_structp png_ptr, png_infop info_ptr,
1841 png_int_32 offset_x, png_int_32 offset_y, int unit_type));
1844 #ifdef PNG_pCAL_SUPPORTED
1845 PNG_EXPORT(147, png_uint_32, png_get_pCAL,
1846 (png_const_structp png_ptr, png_const_infop info_ptr,
1847 png_charp *purpose, png_int_32 *X0, png_int_32 *X1, int *type,
1849 png_charp *units, png_charpp *params));
1852 #ifdef PNG_pCAL_SUPPORTED
1853 PNG_EXPORT(148, void, png_set_pCAL, (png_structp png_ptr,
1855 png_const_charp purpose, png_int_32 X0, png_int_32 X1, int type,
1856 int nparams, png_const_charp units, png_charpp params));
1859 #ifdef PNG_pHYs_SUPPORTED
1860 PNG_EXPORT(149, png_uint_32, png_get_pHYs,
1861 (png_const_structp png_ptr, png_const_infop info_ptr,
1862 png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type));
1865 #ifdef PNG_pHYs_SUPPORTED
1866 PNG_EXPORT(150, void, png_set_pHYs,
1867 (png_structp png_ptr, png_infop info_ptr,
1868 png_uint_32 res_x, png_uint_32 res_y, int unit_type));
1871 PNG_EXPORT(151, png_uint_32, png_get_PLTE,
1872 (png_const_structp png_ptr, png_const_infop info_ptr,
1873 png_colorp *palette, int *num_palette));
1875 PNG_EXPORT(152, void, png_set_PLTE,
1876 (png_structp png_ptr, png_infop info_ptr,
1877 png_const_colorp palette, int num_palette));
1879 #ifdef PNG_sBIT_SUPPORTED
1880 PNG_EXPORT(153, png_uint_32, png_get_sBIT,
1881 (png_const_structp png_ptr, png_infop info_ptr,
1882 png_color_8p *sig_bit));
1885 #ifdef PNG_sBIT_SUPPORTED
1886 PNG_EXPORT(154, void, png_set_sBIT,
1887 (png_structp png_ptr, png_infop info_ptr, png_const_color_8p sig_bit));
1890 #ifdef PNG_sRGB_SUPPORTED
1891 PNG_EXPORT(155, png_uint_32, png_get_sRGB, (png_const_structp png_ptr,
1892 png_const_infop info_ptr, int *file_srgb_intent));
1895 #ifdef PNG_sRGB_SUPPORTED
1896 PNG_EXPORT(156, void, png_set_sRGB,
1897 (png_structp png_ptr, png_infop info_ptr, int srgb_intent));
1898 PNG_EXPORT(157, void, png_set_sRGB_gAMA_and_cHRM, (png_structp png_ptr,
1899 png_infop info_ptr, int srgb_intent));
1902 #ifdef PNG_iCCP_SUPPORTED
1903 PNG_EXPORT(158, png_uint_32, png_get_iCCP,
1904 (png_const_structp png_ptr, png_const_infop info_ptr,
1905 png_charpp name, int *compression_type, png_bytepp profile,
1906 png_uint_32 *proflen));
1909 #ifdef PNG_iCCP_SUPPORTED
1910 PNG_EXPORT(159, void, png_set_iCCP,
1911 (png_structp png_ptr, png_infop info_ptr,
1912 png_const_charp name, int compression_type, png_const_bytep profile,
1913 png_uint_32 proflen));
1916 #ifdef PNG_sPLT_SUPPORTED
1917 PNG_EXPORT(160, png_uint_32, png_get_sPLT,
1918 (png_const_structp png_ptr, png_const_infop info_ptr,
1919 png_sPLT_tpp entries));
1922 #ifdef PNG_sPLT_SUPPORTED
1923 PNG_EXPORT(161, void, png_set_sPLT,
1924 (png_structp png_ptr, png_infop info_ptr,
1925 png_const_sPLT_tp entries, int nentries));
1928 #ifdef PNG_TEXT_SUPPORTED
1929 /* png_get_text also returns the number of text chunks in *num_text */
1930 PNG_EXPORT(162, png_uint_32, png_get_text,
1931 (png_const_structp png_ptr, png_const_infop info_ptr,
1932 png_textp *text_ptr, int *num_text));
1935 /* Note while png_set_text() will accept a structure whose text,
1936 * language, and translated keywords are NULL pointers, the structure
1937 * returned by png_get_text will always contain regular
1938 * zero-terminated C strings. They might be empty strings but
1939 * they will never be NULL pointers.
1942 #ifdef PNG_TEXT_SUPPORTED
1943 PNG_EXPORT(163, void, png_set_text,
1944 (png_structp png_ptr, png_infop info_ptr,
1945 png_const_textp text_ptr, int num_text));
1948 #ifdef PNG_tIME_SUPPORTED
1949 PNG_EXPORT(164, png_uint_32, png_get_tIME,
1950 (png_const_structp png_ptr, png_infop info_ptr, png_timep *mod_time));
1953 #ifdef PNG_tIME_SUPPORTED
1954 PNG_EXPORT(165, void, png_set_tIME,
1955 (png_structp png_ptr, png_infop info_ptr, png_const_timep mod_time));
1958 #ifdef PNG_tRNS_SUPPORTED
1959 PNG_EXPORT(166, png_uint_32, png_get_tRNS,
1960 (png_const_structp png_ptr, png_infop info_ptr,
1961 png_bytep *trans_alpha, int *num_trans, png_color_16p *trans_color));
1964 #ifdef PNG_tRNS_SUPPORTED
1965 PNG_EXPORT(167, void, png_set_tRNS,
1966 (png_structp png_ptr, png_infop info_ptr,
1967 png_const_bytep trans_alpha, int num_trans,
1968 png_const_color_16p trans_color));
1971 #ifdef PNG_sCAL_SUPPORTED
1972 PNG_FP_EXPORT(168, png_uint_32, png_get_sCAL,
1973 (png_const_structp png_ptr, png_const_infop info_ptr,
1974 int *unit, double *width, double *height));
1975 #ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
1976 /* NOTE: this API is currently implemented using floating point arithmetic,
1977 * consequently it can only be used on systems with floating point support.
1978 * In any case the range of values supported by png_fixed_point is small and it
1979 * is highly recommended that png_get_sCAL_s be used instead.
1981 PNG_FIXED_EXPORT(214, png_uint_32, png_get_sCAL_fixed,
1982 (png_structp png_ptr, png_const_infop info_ptr, int *unit,
1983 png_fixed_point *width,
1984 png_fixed_point *height));
1986 PNG_EXPORT(169, png_uint_32, png_get_sCAL_s,
1987 (png_const_structp png_ptr, png_const_infop info_ptr,
1988 int *unit, png_charpp swidth, png_charpp sheight));
1990 PNG_FP_EXPORT(170, void, png_set_sCAL,
1991 (png_structp png_ptr, png_infop info_ptr,
1992 int unit, double width, double height));
1993 PNG_FIXED_EXPORT(213, void, png_set_sCAL_fixed, (png_structp png_ptr,
1994 png_infop info_ptr, int unit, png_fixed_point width,
1995 png_fixed_point height));
1996 PNG_EXPORT(171, void, png_set_sCAL_s,
1997 (png_structp png_ptr, png_infop info_ptr,
1998 int unit, png_const_charp swidth, png_const_charp sheight));
1999 #endif /* PNG_sCAL_SUPPORTED */
2001 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
2002 /* Provide a list of chunks and how they are to be handled, if the built-in
2003 handling or default unknown chunk handling is not desired. Any chunks not
2004 listed will be handled in the default manner. The IHDR and IEND chunks
2006 keep = 0: follow default behaviour
2008 = 2: keep only if safe-to-copy
2009 = 3: keep even if unsafe-to-copy
2011 PNG_EXPORT(172, void, png_set_keep_unknown_chunks,
2012 (png_structp png_ptr, int keep,
2013 png_const_bytep chunk_list, int num_chunks));
2014 PNG_EXPORT(173, int, png_handle_as_unknown, (png_structp png_ptr,
2015 png_const_bytep chunk_name));
2017 #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
2018 PNG_EXPORT(174, void, png_set_unknown_chunks, (png_structp png_ptr,
2019 png_infop info_ptr, png_const_unknown_chunkp unknowns,
2021 PNG_EXPORT(175, void, png_set_unknown_chunk_location,
2022 (png_structp png_ptr, png_infop info_ptr, int chunk, int location));
2023 PNG_EXPORT(176, int, png_get_unknown_chunks, (png_const_structp png_ptr,
2024 png_const_infop info_ptr, png_unknown_chunkpp entries));
2027 /* Png_free_data() will turn off the "valid" flag for anything it frees.
2028 * If you need to turn it off for a chunk that your application has freed,
2029 * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK);
2031 PNG_EXPORT(177, void, png_set_invalid,
2032 (png_structp png_ptr, png_infop info_ptr, int mask));
2034 #ifdef PNG_INFO_IMAGE_SUPPORTED
2035 /* The "params" pointer is currently not used and is for future expansion. */
2036 PNG_EXPORT(178, void, png_read_png, (png_structp png_ptr, png_infop info_ptr,
2037 int transforms, png_voidp params));
2038 PNG_EXPORT(179, void, png_write_png, (png_structp png_ptr, png_infop info_ptr,
2039 int transforms, png_voidp params));
2042 PNG_EXPORT(180, png_const_charp, png_get_copyright,
2043 (png_const_structp png_ptr));
2044 PNG_EXPORT(181, png_const_charp, png_get_header_ver,
2045 (png_const_structp png_ptr));
2046 PNG_EXPORT(182, png_const_charp, png_get_header_version,
2047 (png_const_structp png_ptr));
2048 PNG_EXPORT(183, png_const_charp, png_get_libpng_ver,
2049 (png_const_structp png_ptr));
2051 #ifdef PNG_MNG_FEATURES_SUPPORTED
2052 PNG_EXPORT(184, png_uint_32, png_permit_mng_features, (png_structp png_ptr,
2053 png_uint_32 mng_features_permitted));
2056 /* For use in png_set_keep_unknown, added to version 1.2.6 */
2057 #define PNG_HANDLE_CHUNK_AS_DEFAULT 0
2058 #define PNG_HANDLE_CHUNK_NEVER 1
2059 #define PNG_HANDLE_CHUNK_IF_SAFE 2
2060 #define PNG_HANDLE_CHUNK_ALWAYS 3
2062 /* Strip the prepended error numbers ("#nnn ") from error and warning
2063 * messages before passing them to the error or warning handler.
2065 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
2066 PNG_EXPORT(185, void, png_set_strip_error_numbers,
2067 (png_structp png_ptr,
2068 png_uint_32 strip_mode));
2071 /* Added in libpng-1.2.6 */
2072 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
2073 PNG_EXPORT(186, void, png_set_user_limits, (png_structp png_ptr,
2074 png_uint_32 user_width_max, png_uint_32 user_height_max));
2075 PNG_EXPORT(187, png_uint_32, png_get_user_width_max,
2076 (png_const_structp png_ptr));
2077 PNG_EXPORT(188, png_uint_32, png_get_user_height_max,
2078 (png_const_structp png_ptr));
2079 /* Added in libpng-1.4.0 */
2080 PNG_EXPORT(189, void, png_set_chunk_cache_max, (png_structp png_ptr,
2081 png_uint_32 user_chunk_cache_max));
2082 PNG_EXPORT(190, png_uint_32, png_get_chunk_cache_max,
2083 (png_const_structp png_ptr));
2084 /* Added in libpng-1.4.1 */
2085 PNG_EXPORT(191, void, png_set_chunk_malloc_max, (png_structp png_ptr,
2086 png_alloc_size_t user_chunk_cache_max));
2087 PNG_EXPORT(192, png_alloc_size_t, png_get_chunk_malloc_max,
2088 (png_const_structp png_ptr));
2091 #if defined(PNG_INCH_CONVERSIONS_SUPPORTED)
2092 PNG_EXPORT(193, png_uint_32, png_get_pixels_per_inch,
2093 (png_const_structp png_ptr, png_const_infop info_ptr));
2095 PNG_EXPORT(194, png_uint_32, png_get_x_pixels_per_inch,
2096 (png_const_structp png_ptr, png_const_infop info_ptr));
2098 PNG_EXPORT(195, png_uint_32, png_get_y_pixels_per_inch,
2099 (png_const_structp png_ptr, png_const_infop info_ptr));
2101 PNG_FP_EXPORT(196, float, png_get_x_offset_inches,
2102 (png_const_structp png_ptr, png_const_infop info_ptr));
2103 #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */
2104 PNG_FIXED_EXPORT(211, png_fixed_point, png_get_x_offset_inches_fixed,
2105 (png_structp png_ptr, png_const_infop info_ptr));
2108 PNG_FP_EXPORT(197, float, png_get_y_offset_inches, (png_const_structp png_ptr,
2109 png_const_infop info_ptr));
2110 #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */
2111 PNG_FIXED_EXPORT(212, png_fixed_point, png_get_y_offset_inches_fixed,
2112 (png_structp png_ptr, png_const_infop info_ptr));
2115 # ifdef PNG_pHYs_SUPPORTED
2116 PNG_EXPORT(198, png_uint_32, png_get_pHYs_dpi, (png_const_structp png_ptr,
2117 png_const_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y,
2119 # endif /* PNG_pHYs_SUPPORTED */
2120 #endif /* PNG_INCH_CONVERSIONS_SUPPORTED */
2122 /* Added in libpng-1.4.0 */
2123 #ifdef PNG_IO_STATE_SUPPORTED
2124 PNG_EXPORT(199, png_uint_32, png_get_io_state, (png_structp png_ptr));
2126 PNG_EXPORTA(200, png_const_bytep, png_get_io_chunk_name,
2127 (png_structp png_ptr), PNG_DEPRECATED);
2128 PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type,
2129 (png_const_structp png_ptr));
2131 /* The flags returned by png_get_io_state() are the following: */
2132 # define PNG_IO_NONE 0x0000 /* no I/O at this moment */
2133 # define PNG_IO_READING 0x0001 /* currently reading */
2134 # define PNG_IO_WRITING 0x0002 /* currently writing */
2135 # define PNG_IO_SIGNATURE 0x0010 /* currently at the file signature */
2136 # define PNG_IO_CHUNK_HDR 0x0020 /* currently at the chunk header */
2137 # define PNG_IO_CHUNK_DATA 0x0040 /* currently at the chunk data */
2138 # define PNG_IO_CHUNK_CRC 0x0080 /* currently at the chunk crc */
2139 # define PNG_IO_MASK_OP 0x000f /* current operation: reading/writing */
2140 # define PNG_IO_MASK_LOC 0x00f0 /* current location: sig/hdr/data/crc */
2141 #endif /* ?PNG_IO_STATE_SUPPORTED */
2143 /* Interlace support. The following macros are always defined so that if
2144 * libpng interlace handling is turned off the macros may be used to handle
2145 * interlaced images within the application.
2147 #define PNG_INTERLACE_ADAM7_PASSES 7
2149 /* Two macros to return the first row and first column of the original,
2150 * full, image which appears in a given pass. 'pass' is in the range 0
2151 * to 6 and the result is in the range 0 to 7.
2153 #define PNG_PASS_START_ROW(pass) (((1U&~(pass))<<(3-((pass)>>1)))&7)
2154 #define PNG_PASS_START_COL(pass) (((1U& (pass))<<(3-(((pass)+1)>>1)))&7)
2156 /* Two macros to help evaluate the number of rows or columns in each
2157 * pass. This is expressed as a shift - effectively log2 of the number or
2158 * rows or columns in each 8x8 tile of the original image.
2160 #define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3)
2161 #define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3)
2163 /* Hence two macros to determine the number of rows or columns in a given
2164 * pass of an image given its height or width. In fact these macros may
2165 * return non-zero even though the sub-image is empty, because the other
2166 * dimension may be empty for a small image.
2168 #define PNG_PASS_ROWS(height, pass) (((height)+(((1<<PNG_PASS_ROW_SHIFT(pass))\
2169 -1)-PNG_PASS_START_ROW(pass)))>>PNG_PASS_ROW_SHIFT(pass))
2170 #define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\
2171 -1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass))
2173 /* For the reader row callbacks (both progressive and sequential) it is
2174 * necessary to find the row in the output image given a row in an interlaced
2175 * image, so two more macros:
2177 #define PNG_ROW_FROM_PASS_ROW(yIn, pass) \
2178 (((yIn)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass))
2179 #define PNG_COL_FROM_PASS_COL(xIn, pass) \
2180 (((xIn)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass))
2182 /* Two macros which return a boolean (0 or 1) saying whether the given row
2183 * or column is in a particular pass. These use a common utility macro that
2184 * returns a mask for a given pass - the offset 'off' selects the row or
2185 * column version. The mask has the appropriate bit set for each column in
2188 #define PNG_PASS_MASK(pass,off) ( \
2189 ((0x110145AFU>>(((7-(off))-(pass))<<2)) & 0xFU) | \
2190 ((0x01145AF0U>>(((7-(off))-(pass))<<2)) & 0xF0U))
2192 #define PNG_ROW_IN_INTERLACE_PASS(y, pass) \
2193 ((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1)
2194 #define PNG_COL_IN_INTERLACE_PASS(x, pass) \
2195 ((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1)
2197 #ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
2198 /* With these routines we avoid an integer divide, which will be slower on
2199 * most machines. However, it does take more operations than the corresponding
2200 * divide method, so it may be slower on a few RISC systems. There are two
2201 * shifts (by 8 or 16 bits) and an addition, versus a single integer divide.
2203 * Note that the rounding factors are NOT supposed to be the same! 128 and
2204 * 32768 are correct for the NODIV code; 127 and 32767 are correct for the
2207 * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
2210 /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */
2212 # define png_composite(composite, fg, alpha, bg) \
2213 { png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \
2214 * (png_uint_16)(alpha) \
2215 + (png_uint_16)(bg)*(png_uint_16)(255 \
2216 - (png_uint_16)(alpha)) + (png_uint_16)128); \
2217 (composite) = (png_byte)((temp + (temp >> 8)) >> 8); }
2219 # define png_composite_16(composite, fg, alpha, bg) \
2220 { png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) \
2221 * (png_uint_32)(alpha) \
2222 + (png_uint_32)(bg)*(png_uint_32)(65535L \
2223 - (png_uint_32)(alpha)) + (png_uint_32)32768L); \
2224 (composite) = (png_uint_16)((temp + (temp >> 16)) >> 16); }
2226 #else /* Standard method using integer division */
2228 # define png_composite(composite, fg, alpha, bg) \
2229 (composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) + \
2230 (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \
2231 (png_uint_16)127) / 255)
2233 # define png_composite_16(composite, fg, alpha, bg) \
2234 (composite) = (png_uint_16)(((png_uint_32)(fg) * (png_uint_32)(alpha) + \
2235 (png_uint_32)(bg)*(png_uint_32)(65535L - (png_uint_32)(alpha)) + \
2236 (png_uint_32)32767) / (png_uint_32)65535L)
2237 #endif /* PNG_READ_COMPOSITE_NODIV_SUPPORTED */
2239 #ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED
2240 PNG_EXPORT(201, png_uint_32, png_get_uint_32, (png_const_bytep buf));
2241 PNG_EXPORT(202, png_uint_16, png_get_uint_16, (png_const_bytep buf));
2242 PNG_EXPORT(203, png_int_32, png_get_int_32, (png_const_bytep buf));
2245 PNG_EXPORT(204, png_uint_32, png_get_uint_31, (png_structp png_ptr,
2246 png_const_bytep buf));
2247 /* No png_get_int_16 -- may be added if there's a real need for it. */
2249 /* Place a 32-bit number into a buffer in PNG byte order (big-endian). */
2250 #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
2251 PNG_EXPORT(205, void, png_save_uint_32, (png_bytep buf, png_uint_32 i));
2253 #ifdef PNG_SAVE_INT_32_SUPPORTED
2254 PNG_EXPORT(206, void, png_save_int_32, (png_bytep buf, png_int_32 i));
2257 /* Place a 16-bit number into a buffer in PNG byte order.
2258 * The parameter is declared unsigned int, not png_uint_16,
2259 * just to avoid potential problems on pre-ANSI C compilers.
2261 #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
2262 PNG_EXPORT(207, void, png_save_uint_16, (png_bytep buf, unsigned int i));
2263 /* No png_save_int_16 -- may be added if there's a real need for it. */
2266 #ifdef PNG_USE_READ_MACROS
2267 /* Inline macros to do direct reads of bytes from the input buffer.
2268 * The png_get_int_32() routine assumes we are using two's complement
2269 * format for negative values, which is almost certainly true.
2271 # define png_get_uint_32(buf) \
2272 (((png_uint_32)(*(buf)) << 24) + \
2273 ((png_uint_32)(*((buf) + 1)) << 16) + \
2274 ((png_uint_32)(*((buf) + 2)) << 8) + \
2275 ((png_uint_32)(*((buf) + 3))))
2277 /* From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the
2278 * function) incorrectly returned a value of type png_uint_32.
2280 # define png_get_uint_16(buf) \
2282 (((unsigned int)(*(buf)) << 8) + \
2283 ((unsigned int)(*((buf) + 1)))))
2285 # define png_get_int_32(buf) \
2286 ((png_int_32)((*(buf) & 0x80) \
2287 ? -((png_int_32)((png_get_uint_32(buf) ^ 0xffffffffL) + 1)) \
2288 : (png_int_32)png_get_uint_32(buf)))
2291 /* Maintainer: Put new public prototypes here ^, in libpng.3, and project
2295 /* The last ordinal number (this is the *last* one already used; the next
2296 * one to use is one more than this.) Maintainer, remember to add an entry to
2297 * scripts/symbols.def as well.
2299 #ifdef PNG_EXPORT_LAST_ORDINAL
2300 PNG_EXPORT_LAST_ORDINAL(221);
2307 #endif /* PNG_VERSION_INFO_ONLY */
2308 /* Do not put anything past this line */