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1
2/* png.h - header file for PNG reference library
3 *
4 * libpng version 1.4.4 - September 23, 2010
5 * Copyright (c) 1998-2010 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.)
8 *
9 * This code is released under the libpng license (See LICENSE, below)
10 *
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 1.4.4 - September 23, 2010: Glenn
15 * See also "Contributing Authors", below.
16 *
17 * Note about libpng version numbers:
18 *
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:
24 *
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
34 * 0.98 0.98 98 2.0.98
35 * 0.99 0.99 98 2.0.99
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.
43 * 1.0.3 10003
44 * 1.0.3a-d 10004
45 * 1.0.4 10004
46 * 1.0.4a-f 10005
47 * 1.0.5 (+ 2 patches) 10005
48 * 1.0.5a-d 10006
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)
53 * 1.0.6g 10007
54 * 1.0.6h 10007 10.6h (testing xy.z so-numbering)
55 * 1.0.6i 10007 10.6i
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 * 1.4.1rc02-04 14 10401 14.so.14.1[.0]
141 * 1.4.1 14 10401 14.so.14.1[.0]
142 * 1.4.2beta01 14 10402 14.so.14.2[.0]
143 * 1.4.2rc02-06 14 10402 14.so.14.2[.0]
144 * 1.4.2 14 10402 14.so.14.2[.0]
145 * 1.4.3beta01-05 14 10403 14.so.14.3[.0]
146 * 1.4.3rc01-03 14 10403 14.so.14.3[.0]
147 * 1.4.3 14 10403 14.so.14.3[.0]
148 * 1.4.4beta01-08 14 10404 14.so.14.4[.0]
149 * 1.4.4rc01-06 14 10404 14.so.14.4[.0]
150 *
151 * Henceforth the source version will match the shared-library major
152 * and minor numbers; the shared-library major version number will be
153 * used for changes in backward compatibility, as it is intended. The
154 * PNG_LIBPNG_VER macro, which is not used within libpng but is available
155 * for applications, is an unsigned integer of the form xyyzz corresponding
156 * to the source version x.y.z (leading zeros in y and z). Beta versions
157 * were given the previous public release number plus a letter, until
158 * version 1.0.6j; from then on they were given the upcoming public
159 * release number plus "betaNN" or "rcN".
160 *
161 * Binary incompatibility exists only when applications make direct access
162 * to the info_ptr or png_ptr members through png.h, and the compiled
163 * application is loaded with a different version of the library.
164 *
165 * DLLNUM will change each time there are forward or backward changes
166 * in binary compatibility (e.g., when a new feature is added).
167 *
168 * See libpng.txt or libpng.3 for more information. The PNG specification
169 * is available as a W3C Recommendation and as an ISO Specification,
170 * <http://www.w3.org/TR/2003/REC-PNG-20031110/
171 */
172
173/*
174 * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
175 *
176 * If you modify libpng you may insert additional notices immediately following
177 * this sentence.
178 *
179 * This code is released under the libpng license.
180 *
181 * libpng versions 1.2.6, August 15, 2004, through 1.4.4, September 23, 2010, are
182 * Copyright (c) 2004, 2006-2010 Glenn Randers-Pehrson, and are
183 * distributed according to the same disclaimer and license as libpng-1.2.5
184 * with the following individual added to the list of Contributing Authors:
185 *
186 * Cosmin Truta
187 *
188 * libpng versions 1.0.7, July 1, 2000, through 1.2.5, October 3, 2002, are
189 * Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are
190 * distributed according to the same disclaimer and license as libpng-1.0.6
191 * with the following individuals added to the list of Contributing Authors:
192 *
193 * Simon-Pierre Cadieux
194 * Eric S. Raymond
195 * Gilles Vollant
196 *
197 * and with the following additions to the disclaimer:
198 *
199 * There is no warranty against interference with your enjoyment of the
200 * library or against infringement. There is no warranty that our
201 * efforts or the library will fulfill any of your particular purposes
202 * or needs. This library is provided with all faults, and the entire
203 * risk of satisfactory quality, performance, accuracy, and effort is with
204 * the user.
205 *
206 * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
207 * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson, and are
208 * distributed according to the same disclaimer and license as libpng-0.96,
209 * with the following individuals added to the list of Contributing Authors:
210 *
211 * Tom Lane
212 * Glenn Randers-Pehrson
213 * Willem van Schaik
214 *
215 * libpng versions 0.89, June 1996, through 0.96, May 1997, are
216 * Copyright (c) 1996, 1997 Andreas Dilger
217 * Distributed according to the same disclaimer and license as libpng-0.88,
218 * with the following individuals added to the list of Contributing Authors:
219 *
220 * John Bowler
221 * Kevin Bracey
222 * Sam Bushell
223 * Magnus Holmgren
224 * Greg Roelofs
225 * Tom Tanner
226 *
227 * libpng versions 0.5, May 1995, through 0.88, January 1996, are
228 * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
229 *
230 * For the purposes of this copyright and license, "Contributing Authors"
231 * is defined as the following set of individuals:
232 *
233 * Andreas Dilger
234 * Dave Martindale
235 * Guy Eric Schalnat
236 * Paul Schmidt
237 * Tim Wegner
238 *
239 * The PNG Reference Library is supplied "AS IS". The Contributing Authors
240 * and Group 42, Inc. disclaim all warranties, expressed or implied,
241 * including, without limitation, the warranties of merchantability and of
242 * fitness for any purpose. The Contributing Authors and Group 42, Inc.
243 * assume no liability for direct, indirect, incidental, special, exemplary,
244 * or consequential damages, which may result from the use of the PNG
245 * Reference Library, even if advised of the possibility of such damage.
246 *
247 * Permission is hereby granted to use, copy, modify, and distribute this
248 * source code, or portions hereof, for any purpose, without fee, subject
249 * to the following restrictions:
250 *
251 * 1. The origin of this source code must not be misrepresented.
252 *
253 * 2. Altered versions must be plainly marked as such and
254 * must not be misrepresented as being the original source.
255 *
256 * 3. This Copyright notice may not be removed or altered from
257 * any source or altered source distribution.
258 *
259 * The Contributing Authors and Group 42, Inc. specifically permit, without
260 * fee, and encourage the use of this source code as a component to
261 * supporting the PNG file format in commercial products. If you use this
262 * source code in a product, acknowledgment is not required but would be
263 * appreciated.
264 */
265
266/*
267 * A "png_get_copyright" function is available, for convenient use in "about"
268 * boxes and the like:
269 *
270 * printf("%s",png_get_copyright(NULL));
271 *
272 * Also, the PNG logo (in PNG format, of course) is supplied in the
273 * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
274 */
275
276/*
277 * Libpng is OSI Certified Open Source Software. OSI Certified is a
278 * certification mark of the Open Source Initiative.
279 */
280
281/*
282 * The contributing authors would like to thank all those who helped
283 * with testing, bug fixes, and patience. This wouldn't have been
284 * possible without all of you.
285 *
286 * Thanks to Frank J. T. Wojcik for helping with the documentation.
287 */
288
289/*
290 * Y2K compliance in libpng:
291 * =========================
292 *
293 * September 23, 2010
294 *
295 * Since the PNG Development group is an ad-hoc body, we can't make
296 * an official declaration.
297 *
298 * This is your unofficial assurance that libpng from version 0.71 and
299 * upward through 1.4.4 are Y2K compliant. It is my belief that earlier
300 * versions were also Y2K compliant.
301 *
302 * Libpng only has three year fields. One is a 2-byte unsigned integer
303 * that will hold years up to 65535. The other two hold the date in text
304 * format, and will hold years up to 9999.
305 *
306 * The integer is
307 * "png_uint_16 year" in png_time_struct.
308 *
309 * The strings are
310 * "png_charp time_buffer" in png_struct and
311 * "near_time_buffer", which is a local character string in png.c.
312 *
313 * There are seven time-related functions:
314 * png.c: png_convert_to_rfc_1123() in png.c
315 * (formerly png_convert_to_rfc_1152() in error)
316 * png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
317 * png_convert_from_time_t() in pngwrite.c
318 * png_get_tIME() in pngget.c
319 * png_handle_tIME() in pngrutil.c, called in pngread.c
320 * png_set_tIME() in pngset.c
321 * png_write_tIME() in pngwutil.c, called in pngwrite.c
322 *
323 * All handle dates properly in a Y2K environment. The
324 * png_convert_from_time_t() function calls gmtime() to convert from system
325 * clock time, which returns (year - 1900), which we properly convert to
326 * the full 4-digit year. There is a possibility that applications using
327 * libpng are not passing 4-digit years into the png_convert_to_rfc_1123()
328 * function, or that they are incorrectly passing only a 2-digit year
329 * instead of "year - 1900" into the png_convert_from_struct_tm() function,
330 * but this is not under our control. The libpng documentation has always
331 * stated that it works with 4-digit years, and the APIs have been
332 * documented as such.
333 *
334 * The tIME chunk itself is also Y2K compliant. It uses a 2-byte unsigned
335 * integer to hold the year, and can hold years as large as 65535.
336 *
337 * zlib, upon which libpng depends, is also Y2K compliant. It contains
338 * no date-related code.
339 *
340 * Glenn Randers-Pehrson
341 * libpng maintainer
342 * PNG Development Group
343 */
344
345#ifndef PNG_H
346#define PNG_H
347
348/* This is not the place to learn how to use libpng. The file libpng.txt
349 * describes how to use libpng, and the file example.c summarizes it
350 * with some code on which to build. This file is useful for looking
351 * at the actual function definitions and structure components.
352 */
353
354/* Version information for png.h - this should match the version in png.c */
355#define PNG_LIBPNG_VER_STRING "1.4.4"
356#define PNG_HEADER_VERSION_STRING \
357 " libpng version 1.4.4 - September 23, 2010\n"
358
359#define PNG_LIBPNG_VER_SONUM 14
360#define PNG_LIBPNG_VER_DLLNUM 14
361
362/* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
363#define PNG_LIBPNG_VER_MAJOR 1
364#define PNG_LIBPNG_VER_MINOR 4
365#define PNG_LIBPNG_VER_RELEASE 4
366/* This should match the numeric part of the final component of
367 * PNG_LIBPNG_VER_STRING, omitting any leading zero:
368 */
369
370#define PNG_LIBPNG_VER_BUILD 0
371
372/* Release Status */
373#define PNG_LIBPNG_BUILD_ALPHA 1
374#define PNG_LIBPNG_BUILD_BETA 2
375#define PNG_LIBPNG_BUILD_RC 3
376#define PNG_LIBPNG_BUILD_STABLE 4
377#define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7
378
379/* Release-Specific Flags */
380#define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with
381 PNG_LIBPNG_BUILD_STABLE only */
382#define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with
383 PNG_LIBPNG_BUILD_SPECIAL */
384#define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with
385 PNG_LIBPNG_BUILD_PRIVATE */
386
387#define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_BETA
388
389/* Careful here. At one time, Guy wanted to use 082, but that would be octal.
390 * We must not include leading zeros.
391 * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only
392 * version 1.0.0 was mis-numbered 100 instead of 10000). From
393 * version 1.0.1 it's xxyyzz, where x=major, y=minor, z=release
394 */
395#define PNG_LIBPNG_VER 10404 /* 1.4.4 */
396
397#ifndef PNG_VERSION_INFO_ONLY
398/* Include the compression library's header */
399#include "zlib.h"
400#endif
401
402/* Include all user configurable info, including optional assembler routines */
403#include "pngconf.h"
404
405/*
406 * Added at libpng-1.2.8
407 *
408 * Ref MSDN: Private as priority over Special
409 * VS_FF_PRIVATEBUILD File *was not* built using standard release
410 * procedures. If this value is given, the StringFileInfo block must
411 * contain a PrivateBuild string.
412 *
413 * VS_FF_SPECIALBUILD File *was* built by the original company using
414 * standard release procedures but is a variation of the standard
415 * file of the same version number. If this value is given, the
416 * StringFileInfo block must contain a SpecialBuild string.
417 */
418
419#ifdef PNG_USER_PRIVATEBUILD
420# define PNG_LIBPNG_BUILD_TYPE \
421 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE)
422#else
423# ifdef PNG_LIBPNG_SPECIALBUILD
424# define PNG_LIBPNG_BUILD_TYPE \
425 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL)
426# else
427# define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE)
428# endif
429#endif
430
431#ifndef PNG_VERSION_INFO_ONLY
432
433/* Inhibit C++ name-mangling for libpng functions but not for system calls. */
434#ifdef __cplusplus
435extern "C" {
436#endif /* __cplusplus */
437
438/* This file is arranged in several sections. The first section contains
439 * structure and type definitions. The second section contains the external
440 * library functions, while the third has the internal library functions,
441 * which applications aren't expected to use directly.
442 */
443
444/* Variables declared in png.c - only it needs to define PNG_NO_EXTERN */
445#if !defined(PNG_NO_EXTERN) || defined(PNG_ALWAYS_EXTERN)
446/* Version information for C files, stored in png.c. This had better match
447 * the version above.
448 */
449#define png_libpng_ver png_get_header_ver(NULL)
450
451#endif /* PNG_NO_EXTERN */
452
453/* Three color definitions. The order of the red, green, and blue, (and the
454 * exact size) is not important, although the size of the fields need to
455 * be png_byte or png_uint_16 (as defined below).
456 */
457typedef struct png_color_struct
458{
459 png_byte red;
460 png_byte green;
461 png_byte blue;
462} png_color;
463typedef png_color FAR * png_colorp;
464typedef png_color FAR * FAR * png_colorpp;
465
466typedef struct png_color_16_struct
467{
468 png_byte index; /* used for palette files */
469 png_uint_16 red; /* for use in red green blue files */
470 png_uint_16 green;
471 png_uint_16 blue;
472 png_uint_16 gray; /* for use in grayscale files */
473} png_color_16;
474typedef png_color_16 FAR * png_color_16p;
475typedef png_color_16 FAR * FAR * png_color_16pp;
476
477typedef struct png_color_8_struct
478{
479 png_byte red; /* for use in red green blue files */
480 png_byte green;
481 png_byte blue;
482 png_byte gray; /* for use in grayscale files */
483 png_byte alpha; /* for alpha channel files */
484} png_color_8;
485typedef png_color_8 FAR * png_color_8p;
486typedef png_color_8 FAR * FAR * png_color_8pp;
487
488/*
489 * The following two structures are used for the in-core representation
490 * of sPLT chunks.
491 */
492typedef struct png_sPLT_entry_struct
493{
494 png_uint_16 red;
495 png_uint_16 green;
496 png_uint_16 blue;
497 png_uint_16 alpha;
498 png_uint_16 frequency;
499} png_sPLT_entry;
500typedef png_sPLT_entry FAR * png_sPLT_entryp;
501typedef png_sPLT_entry FAR * FAR * png_sPLT_entrypp;
502
503/* When the depth of the sPLT palette is 8 bits, the color and alpha samples
504 * occupy the LSB of their respective members, and the MSB of each member
505 * is zero-filled. The frequency member always occupies the full 16 bits.
506 */
507
508typedef struct png_sPLT_struct
509{
510 png_charp name; /* palette name */
511 png_byte depth; /* depth of palette samples */
512 png_sPLT_entryp entries; /* palette entries */
513 png_int_32 nentries; /* number of palette entries */
514} png_sPLT_t;
515typedef png_sPLT_t FAR * png_sPLT_tp;
516typedef png_sPLT_t FAR * FAR * png_sPLT_tpp;
517
518#ifdef PNG_TEXT_SUPPORTED
519/* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,
520 * and whether that contents is compressed or not. The "key" field
521 * points to a regular zero-terminated C string. The "text", "lang", and
522 * "lang_key" fields can be regular C strings, empty strings, or NULL pointers.
523 * However, the * structure returned by png_get_text() will always contain
524 * regular zero-terminated C strings (possibly empty), never NULL pointers,
525 * so they can be safely used in printf() and other string-handling functions.
526 */
527typedef struct png_text_struct
528{
529 int compression; /* compression value:
530 -1: tEXt, none
531 0: zTXt, deflate
532 1: iTXt, none
533 2: iTXt, deflate */
534 png_charp key; /* keyword, 1-79 character description of "text" */
535 png_charp text; /* comment, may be an empty string (ie "")
536 or a NULL pointer */
537 png_size_t text_length; /* length of the text string */
538#ifdef PNG_iTXt_SUPPORTED
539 png_size_t itxt_length; /* length of the itxt string */
540 png_charp lang; /* language code, 0-79 characters
541 or a NULL pointer */
542 png_charp lang_key; /* keyword translated UTF-8 string, 0 or more
543 chars or a NULL pointer */
544#endif
545} png_text;
546typedef png_text FAR * png_textp;
547typedef png_text FAR * FAR * png_textpp;
548#endif
549
550/* Supported compression types for text in PNG files (tEXt, and zTXt).
551 * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */
552#define PNG_TEXT_COMPRESSION_NONE_WR -3
553#define PNG_TEXT_COMPRESSION_zTXt_WR -2
554#define PNG_TEXT_COMPRESSION_NONE -1
555#define PNG_TEXT_COMPRESSION_zTXt 0
556#define PNG_ITXT_COMPRESSION_NONE 1
557#define PNG_ITXT_COMPRESSION_zTXt 2
558#define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */
559
560/* png_time is a way to hold the time in an machine independent way.
561 * Two conversions are provided, both from time_t and struct tm. There
562 * is no portable way to convert to either of these structures, as far
563 * as I know. If you know of a portable way, send it to me. As a side
564 * note - PNG has always been Year 2000 compliant!
565 */
566typedef struct png_time_struct
567{
568 png_uint_16 year; /* full year, as in, 1995 */
569 png_byte month; /* month of year, 1 - 12 */
570 png_byte day; /* day of month, 1 - 31 */
571 png_byte hour; /* hour of day, 0 - 23 */
572 png_byte minute; /* minute of hour, 0 - 59 */
573 png_byte second; /* second of minute, 0 - 60 (for leap seconds) */
574} png_time;
575typedef png_time FAR * png_timep;
576typedef png_time FAR * FAR * png_timepp;
577
578#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) || \
579 defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
580/* png_unknown_chunk is a structure to hold queued chunks for which there is
581 * no specific support. The idea is that we can use this to queue
582 * up private chunks for output even though the library doesn't actually
583 * know about their semantics.
584 */
585typedef struct png_unknown_chunk_t
586{
587 png_byte name[5];
588 png_byte *data;
589 png_size_t size;
590
591 /* libpng-using applications should NOT directly modify this byte. */
592 png_byte location; /* mode of operation at read time */
593}
594png_unknown_chunk;
595typedef png_unknown_chunk FAR * png_unknown_chunkp;
596typedef png_unknown_chunk FAR * FAR * png_unknown_chunkpp;
597#endif
598
599/* png_info is a structure that holds the information in a PNG file so
600 * that the application can find out the characteristics of the image.
601 * If you are reading the file, this structure will tell you what is
602 * in the PNG file. If you are writing the file, fill in the information
603 * you want to put into the PNG file, then call png_write_info().
604 * The names chosen should be very close to the PNG specification, so
605 * consult that document for information about the meaning of each field.
606 *
607 * With libpng < 0.95, it was only possible to directly set and read the
608 * the values in the png_info_struct, which meant that the contents and
609 * order of the values had to remain fixed. With libpng 0.95 and later,
610 * however, there are now functions that abstract the contents of
611 * png_info_struct from the application, so this makes it easier to use
612 * libpng with dynamic libraries, and even makes it possible to use
613 * libraries that don't have all of the libpng ancillary chunk-handing
614 * functionality.
615 *
616 * In any case, the order of the parameters in png_info_struct should NOT
617 * be changed for as long as possible to keep compatibility with applications
618 * that use the old direct-access method with png_info_struct.
619 *
620 * The following members may have allocated storage attached that should be
621 * cleaned up before the structure is discarded: palette, trans, text,
622 * pcal_purpose, pcal_units, pcal_params, hist, iccp_name, iccp_profile,
623 * splt_palettes, scal_unit, row_pointers, and unknowns. By default, these
624 * are automatically freed when the info structure is deallocated, if they were
625 * allocated internally by libpng. This behavior can be changed by means
626 * of the png_data_freer() function.
627 *
628 * More allocation details: all the chunk-reading functions that
629 * change these members go through the corresponding png_set_*
630 * functions. A function to clear these members is available: see
631 * png_free_data(). The png_set_* functions do not depend on being
632 * able to point info structure members to any of the storage they are
633 * passed (they make their own copies), EXCEPT that the png_set_text
634 * functions use the same storage passed to them in the text_ptr or
635 * itxt_ptr structure argument, and the png_set_rows and png_set_unknowns
636 * functions do not make their own copies.
637 */
638typedef struct png_info_struct
639{
640 /* the following are necessary for every PNG file */
641 png_uint_32 width PNG_DEPSTRUCT; /* width of image in pixels (from IHDR) */
642 png_uint_32 height PNG_DEPSTRUCT; /* height of image in pixels (from IHDR) */
643 png_uint_32 valid PNG_DEPSTRUCT; /* valid chunk data (see PNG_INFO_
644 below) */
645 png_size_t rowbytes PNG_DEPSTRUCT; /* bytes needed to hold an untransformed
646 row */
647 png_colorp palette PNG_DEPSTRUCT; /* array of color values
648 (valid & PNG_INFO_PLTE) */
649 png_uint_16 num_palette PNG_DEPSTRUCT; /* number of color entries in
650 "palette" (PLTE) */
651 png_uint_16 num_trans PNG_DEPSTRUCT; /* number of transparent palette
652 color (tRNS) */
653 png_byte bit_depth PNG_DEPSTRUCT; /* 1, 2, 4, 8, or 16 bits/channel
654 (from IHDR) */
655 png_byte color_type PNG_DEPSTRUCT; /* see PNG_COLOR_TYPE_ below
656 (from IHDR) */
657 /* The following three should have been named *_method not *_type */
658 png_byte compression_type PNG_DEPSTRUCT; /* must be
659 PNG_COMPRESSION_TYPE_BASE (IHDR) */
660 png_byte filter_type PNG_DEPSTRUCT; /* must be PNG_FILTER_TYPE_BASE
661 (from IHDR) */
662 png_byte interlace_type PNG_DEPSTRUCT; /* One of PNG_INTERLACE_NONE,
663 PNG_INTERLACE_ADAM7 */
664
665 /* The following is informational only on read, and not used on writes. */
666 png_byte channels PNG_DEPSTRUCT; /* number of data channels per
667 pixel (1, 2, 3, 4) */
668 png_byte pixel_depth PNG_DEPSTRUCT; /* number of bits per pixel */
669 png_byte spare_byte PNG_DEPSTRUCT; /* to align the data, and for
670 future use */
671 png_byte signature[8] PNG_DEPSTRUCT; /* magic bytes read by libpng
672 from start of file */
673
674 /* The rest of the data is optional. If you are reading, check the
675 * valid field to see if the information in these are valid. If you
676 * are writing, set the valid field to those chunks you want written,
677 * and initialize the appropriate fields below.
678 */
679
680#if defined(PNG_gAMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
681 /* The gAMA chunk describes the gamma characteristics of the system
682 * on which the image was created, normally in the range [1.0, 2.5].
683 * Data is valid if (valid & PNG_INFO_gAMA) is non-zero.
684 */
685 float gamma PNG_DEPSTRUCT; /* gamma value of image,
686 if (valid & PNG_INFO_gAMA) */
687#endif
688
689#ifdef PNG_sRGB_SUPPORTED
690 /* GR-P, 0.96a */
691 /* Data valid if (valid & PNG_INFO_sRGB) non-zero. */
692 png_byte srgb_intent PNG_DEPSTRUCT; /* sRGB rendering intent
693 [0, 1, 2, or 3] */
694#endif
695
696#ifdef PNG_TEXT_SUPPORTED
697 /* The tEXt, and zTXt chunks contain human-readable textual data in
698 * uncompressed, compressed, and optionally compressed forms, respectively.
699 * The data in "text" is an array of pointers to uncompressed,
700 * null-terminated C strings. Each chunk has a keyword that describes the
701 * textual data contained in that chunk. Keywords are not required to be
702 * unique, and the text string may be empty. Any number of text chunks may
703 * be in an image.
704 */
705 int num_text PNG_DEPSTRUCT; /* number of comments read/to write */
706 int max_text PNG_DEPSTRUCT; /* current size of text array */
707 png_textp text PNG_DEPSTRUCT; /* array of comments read/to write */
708#endif /* PNG_TEXT_SUPPORTED */
709
710#ifdef PNG_tIME_SUPPORTED
711 /* The tIME chunk holds the last time the displayed image data was
712 * modified. See the png_time struct for the contents of this struct.
713 */
714 png_time mod_time PNG_DEPSTRUCT;
715#endif
716
717#ifdef PNG_sBIT_SUPPORTED
718 /* The sBIT chunk specifies the number of significant high-order bits
719 * in the pixel data. Values are in the range [1, bit_depth], and are
720 * only specified for the channels in the pixel data. The contents of
721 * the low-order bits is not specified. Data is valid if
722 * (valid & PNG_INFO_sBIT) is non-zero.
723 */
724 png_color_8 sig_bit PNG_DEPSTRUCT; /* significant bits in color channels */
725#endif
726
727#if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_EXPAND_SUPPORTED) || \
728defined(PNG_READ_BACKGROUND_SUPPORTED)
729 /* The tRNS chunk supplies transparency data for paletted images and
730 * other image types that don't need a full alpha channel. There are
731 * "num_trans" transparency values for a paletted image, stored in the
732 * same order as the palette colors, starting from index 0. Values
733 * for the data are in the range [0, 255], ranging from fully transparent
734 * to fully opaque, respectively. For non-paletted images, there is a
735 * single color specified that should be treated as fully transparent.
736 * Data is valid if (valid & PNG_INFO_tRNS) is non-zero.
737 */
738 png_bytep trans_alpha PNG_DEPSTRUCT; /* alpha values for paletted
739 image */
740 png_color_16 trans_color PNG_DEPSTRUCT; /* transparent color for
741 non-palette image */
742#endif
743
744#if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
745 /* The bKGD chunk gives the suggested image background color if the
746 * display program does not have its own background color and the image
747 * is needs to composited onto a background before display. The colors
748 * in "background" are normally in the same color space/depth as the
749 * pixel data. Data is valid if (valid & PNG_INFO_bKGD) is non-zero.
750 */
751 png_color_16 background PNG_DEPSTRUCT;
752#endif
753
754#ifdef PNG_oFFs_SUPPORTED
755 /* The oFFs chunk gives the offset in "offset_unit_type" units rightwards
756 * and downwards from the top-left corner of the display, page, or other
757 * application-specific co-ordinate space. See the PNG_OFFSET_ defines
758 * below for the unit types. Valid if (valid & PNG_INFO_oFFs) non-zero.
759 */
760 png_int_32 x_offset PNG_DEPSTRUCT; /* x offset on page */
761 png_int_32 y_offset PNG_DEPSTRUCT; /* y offset on page */
762 png_byte offset_unit_type PNG_DEPSTRUCT; /* offset units type */
763#endif
764
765#ifdef PNG_pHYs_SUPPORTED
766 /* The pHYs chunk gives the physical pixel density of the image for
767 * display or printing in "phys_unit_type" units (see PNG_RESOLUTION_
768 * defines below). Data is valid if (valid & PNG_INFO_pHYs) is non-zero.
769 */
770 png_uint_32 x_pixels_per_unit PNG_DEPSTRUCT; /* horizontal pixel density */
771 png_uint_32 y_pixels_per_unit PNG_DEPSTRUCT; /* vertical pixel density */
772 png_byte phys_unit_type PNG_DEPSTRUCT; /* resolution type (see
773 PNG_RESOLUTION_ below) */
774#endif
775
776#ifdef PNG_hIST_SUPPORTED
777 /* The hIST chunk contains the relative frequency or importance of the
778 * various palette entries, so that a viewer can intelligently select a
779 * reduced-color palette, if required. Data is an array of "num_palette"
780 * values in the range [0,65535]. Data valid if (valid & PNG_INFO_hIST)
781 * is non-zero.
782 */
783 png_uint_16p hist PNG_DEPSTRUCT;
784#endif
785
786#ifdef PNG_cHRM_SUPPORTED
787 /* The cHRM chunk describes the CIE color characteristics of the monitor
788 * on which the PNG was created. This data allows the viewer to do gamut
789 * mapping of the input image to ensure that the viewer sees the same
790 * colors in the image as the creator. Values are in the range
791 * [0.0, 0.8]. Data valid if (valid & PNG_INFO_cHRM) non-zero.
792 */
793#ifdef PNG_FLOATING_POINT_SUPPORTED
794 float x_white PNG_DEPSTRUCT;
795 float y_white PNG_DEPSTRUCT;
796 float x_red PNG_DEPSTRUCT;
797 float y_red PNG_DEPSTRUCT;
798 float x_green PNG_DEPSTRUCT;
799 float y_green PNG_DEPSTRUCT;
800 float x_blue PNG_DEPSTRUCT;
801 float y_blue PNG_DEPSTRUCT;
802#endif
803#endif
804
805#ifdef PNG_pCAL_SUPPORTED
806 /* The pCAL chunk describes a transformation between the stored pixel
807 * values and original physical data values used to create the image.
808 * The integer range [0, 2^bit_depth - 1] maps to the floating-point
809 * range given by [pcal_X0, pcal_X1], and are further transformed by a
810 * (possibly non-linear) transformation function given by "pcal_type"
811 * and "pcal_params" into "pcal_units". Please see the PNG_EQUATION_
812 * defines below, and the PNG-Group's PNG extensions document for a
813 * complete description of the transformations and how they should be
814 * implemented, and for a description of the ASCII parameter strings.
815 * Data values are valid if (valid & PNG_INFO_pCAL) non-zero.
816 */
817 png_charp pcal_purpose PNG_DEPSTRUCT; /* pCAL chunk description string */
818 png_int_32 pcal_X0 PNG_DEPSTRUCT; /* minimum value */
819 png_int_32 pcal_X1 PNG_DEPSTRUCT; /* maximum value */
820 png_charp pcal_units PNG_DEPSTRUCT; /* Latin-1 string giving physical
821 units */
822 png_charpp pcal_params PNG_DEPSTRUCT; /* ASCII strings containing
823 parameter values */
824 png_byte pcal_type PNG_DEPSTRUCT; /* equation type
825 (see PNG_EQUATION_ below) */
826 png_byte pcal_nparams PNG_DEPSTRUCT; /* number of parameters given
827 in pcal_params */
828#endif
829
830/* New members added in libpng-1.0.6 */
831 png_uint_32 free_me PNG_DEPSTRUCT; /* flags items libpng is
832 responsible for freeing */
833
834#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) || \
835 defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
836 /* Storage for unknown chunks that the library doesn't recognize. */
837 png_unknown_chunkp unknown_chunks PNG_DEPSTRUCT;
838 png_size_t unknown_chunks_num PNG_DEPSTRUCT;
839#endif
840
841#ifdef PNG_iCCP_SUPPORTED
842 /* iCCP chunk data. */
843 png_charp iccp_name PNG_DEPSTRUCT; /* profile name */
844 png_charp iccp_profile PNG_DEPSTRUCT; /* International Color Consortium
845 profile data */
846 /* Note to maintainer: should be png_bytep */
847 png_uint_32 iccp_proflen PNG_DEPSTRUCT; /* ICC profile data length */
848 png_byte iccp_compression PNG_DEPSTRUCT; /* Always zero */
849#endif
850
851#ifdef PNG_sPLT_SUPPORTED
852 /* Data on sPLT chunks (there may be more than one). */
853 png_sPLT_tp splt_palettes PNG_DEPSTRUCT;
854 png_uint_32 splt_palettes_num PNG_DEPSTRUCT;
855#endif
856
857#ifdef PNG_sCAL_SUPPORTED
858 /* The sCAL chunk describes the actual physical dimensions of the
859 * subject matter of the graphic. The chunk contains a unit specification
860 * a byte value, and two ASCII strings representing floating-point
861 * values. The values are width and height corresponsing to one pixel
862 * in the image. This external representation is converted to double
863 * here. Data values are valid if (valid & PNG_INFO_sCAL) is non-zero.
864 */
865 png_byte scal_unit PNG_DEPSTRUCT; /* unit of physical scale */
866#ifdef PNG_FLOATING_POINT_SUPPORTED
867 double scal_pixel_width PNG_DEPSTRUCT; /* width of one pixel */
868 double scal_pixel_height PNG_DEPSTRUCT; /* height of one pixel */
869#endif
870#ifdef PNG_FIXED_POINT_SUPPORTED
871 png_charp scal_s_width PNG_DEPSTRUCT; /* string containing height */
872 png_charp scal_s_height PNG_DEPSTRUCT; /* string containing width */
873#endif
874#endif
875
876#ifdef PNG_INFO_IMAGE_SUPPORTED
877 /* Memory has been allocated if (valid & PNG_ALLOCATED_INFO_ROWS)
878 non-zero */
879 /* Data valid if (valid & PNG_INFO_IDAT) non-zero */
880 png_bytepp row_pointers PNG_DEPSTRUCT; /* the image bits */
881#endif
882
883#if defined(PNG_FIXED_POINT_SUPPORTED) && defined(PNG_gAMA_SUPPORTED)
884 png_fixed_point int_gamma PNG_DEPSTRUCT; /* gamma of image,
885 if (valid & PNG_INFO_gAMA) */
886#endif
887
888#if defined(PNG_cHRM_SUPPORTED) && defined(PNG_FIXED_POINT_SUPPORTED)
889 png_fixed_point int_x_white PNG_DEPSTRUCT;
890 png_fixed_point int_y_white PNG_DEPSTRUCT;
891 png_fixed_point int_x_red PNG_DEPSTRUCT;
892 png_fixed_point int_y_red PNG_DEPSTRUCT;
893 png_fixed_point int_x_green PNG_DEPSTRUCT;
894 png_fixed_point int_y_green PNG_DEPSTRUCT;
895 png_fixed_point int_x_blue PNG_DEPSTRUCT;
896 png_fixed_point int_y_blue PNG_DEPSTRUCT;
897#endif
898
899} png_info;
900
901typedef png_info FAR * png_infop;
902typedef png_info FAR * FAR * png_infopp;
903
904/* Maximum positive integer used in PNG is (2^31)-1 */
905#define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL)
906#define PNG_UINT_32_MAX ((png_uint_32)(-1))
907#define PNG_SIZE_MAX ((png_size_t)(-1))
908
909/* These describe the color_type field in png_info. */
910/* color type masks */
911#define PNG_COLOR_MASK_PALETTE 1
912#define PNG_COLOR_MASK_COLOR 2
913#define PNG_COLOR_MASK_ALPHA 4
914
915/* color types. Note that not all combinations are legal */
916#define PNG_COLOR_TYPE_GRAY 0
917#define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
918#define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR)
919#define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
920#define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
921/* aliases */
922#define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA
923#define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA
924
925/* This is for compression type. PNG 1.0-1.2 only define the single type. */
926#define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */
927#define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE
928
929/* This is for filter type. PNG 1.0-1.2 only define the single type. */
930#define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */
931#define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */
932#define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE
933
934/* These are for the interlacing type. These values should NOT be changed. */
935#define PNG_INTERLACE_NONE 0 /* Non-interlaced image */
936#define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */
937#define PNG_INTERLACE_LAST 2 /* Not a valid value */
938
939/* These are for the oFFs chunk. These values should NOT be changed. */
940#define PNG_OFFSET_PIXEL 0 /* Offset in pixels */
941#define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */
942#define PNG_OFFSET_LAST 2 /* Not a valid value */
943
944/* These are for the pCAL chunk. These values should NOT be changed. */
945#define PNG_EQUATION_LINEAR 0 /* Linear transformation */
946#define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */
947#define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */
948#define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */
949#define PNG_EQUATION_LAST 4 /* Not a valid value */
950
951/* These are for the sCAL chunk. These values should NOT be changed. */
952#define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */
953#define PNG_SCALE_METER 1 /* meters per pixel */
954#define PNG_SCALE_RADIAN 2 /* radians per pixel */
955#define PNG_SCALE_LAST 3 /* Not a valid value */
956
957/* These are for the pHYs chunk. These values should NOT be changed. */
958#define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */
959#define PNG_RESOLUTION_METER 1 /* pixels/meter */
960#define PNG_RESOLUTION_LAST 2 /* Not a valid value */
961
962/* These are for the sRGB chunk. These values should NOT be changed. */
963#define PNG_sRGB_INTENT_PERCEPTUAL 0
964#define PNG_sRGB_INTENT_RELATIVE 1
965#define PNG_sRGB_INTENT_SATURATION 2
966#define PNG_sRGB_INTENT_ABSOLUTE 3
967#define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */
968
969/* This is for text chunks */
970#define PNG_KEYWORD_MAX_LENGTH 79
971
972/* Maximum number of entries in PLTE/sPLT/tRNS arrays */
973#define PNG_MAX_PALETTE_LENGTH 256
974
975/* These determine if an ancillary chunk's data has been successfully read
976 * from the PNG header, or if the application has filled in the corresponding
977 * data in the info_struct to be written into the output file. The values
978 * of the PNG_INFO_<chunk> defines should NOT be changed.
979 */
980#define PNG_INFO_gAMA 0x0001
981#define PNG_INFO_sBIT 0x0002
982#define PNG_INFO_cHRM 0x0004
983#define PNG_INFO_PLTE 0x0008
984#define PNG_INFO_tRNS 0x0010
985#define PNG_INFO_bKGD 0x0020
986#define PNG_INFO_hIST 0x0040
987#define PNG_INFO_pHYs 0x0080
988#define PNG_INFO_oFFs 0x0100
989#define PNG_INFO_tIME 0x0200
990#define PNG_INFO_pCAL 0x0400
991#define PNG_INFO_sRGB 0x0800 /* GR-P, 0.96a */
992#define PNG_INFO_iCCP 0x1000 /* ESR, 1.0.6 */
993#define PNG_INFO_sPLT 0x2000 /* ESR, 1.0.6 */
994#define PNG_INFO_sCAL 0x4000 /* ESR, 1.0.6 */
995#define PNG_INFO_IDAT 0x8000L /* ESR, 1.0.6 */
996
997/* This is used for the transformation routines, as some of them
998 * change these values for the row. It also should enable using
999 * the routines for other purposes.
1000 */
1001typedef struct png_row_info_struct
1002{
1003 png_uint_32 width; /* width of row */
1004 png_size_t rowbytes; /* number of bytes in row */
1005 png_byte color_type; /* color type of row */
1006 png_byte bit_depth; /* bit depth of row */
1007 png_byte channels; /* number of channels (1, 2, 3, or 4) */
1008 png_byte pixel_depth; /* bits per pixel (depth * channels) */
1009} png_row_info;
1010
1011typedef png_row_info FAR * png_row_infop;
1012typedef png_row_info FAR * FAR * png_row_infopp;
1013
1014/* These are the function types for the I/O functions and for the functions
1015 * that allow the user to override the default I/O functions with his or her
1016 * own. The png_error_ptr type should match that of user-supplied warning
1017 * and error functions, while the png_rw_ptr type should match that of the
1018 * user read/write data functions.
1019 */
1020typedef struct png_struct_def png_struct;
1021typedef png_struct FAR * png_structp;
1022
1023typedef void (PNGAPI *png_error_ptr) PNGARG((png_structp, png_const_charp));
1024typedef void (PNGAPI *png_rw_ptr) PNGARG((png_structp, png_bytep, png_size_t));
1025typedef void (PNGAPI *png_flush_ptr) PNGARG((png_structp));
1026typedef void (PNGAPI *png_read_status_ptr) PNGARG((png_structp, png_uint_32,
1027 int));
1028typedef void (PNGAPI *png_write_status_ptr) PNGARG((png_structp, png_uint_32,
1029 int));
1030
1031#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1032typedef void (PNGAPI *png_progressive_info_ptr) PNGARG((png_structp,
1033 png_infop));
1034typedef void (PNGAPI *png_progressive_end_ptr) PNGARG((png_structp, png_infop));
1035typedef void (PNGAPI *png_progressive_row_ptr) PNGARG((png_structp, png_bytep,
1036 png_uint_32, int));
1037#endif
1038
1039#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
1040 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
1041typedef void (PNGAPI *png_user_transform_ptr) PNGARG((png_structp,
1042 png_row_infop, png_bytep));
1043#endif
1044
1045#ifdef PNG_USER_CHUNKS_SUPPORTED
1046typedef int (PNGAPI *png_user_chunk_ptr) PNGARG((png_structp,
1047 png_unknown_chunkp));
1048#endif
1049#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
1050typedef void (PNGAPI *png_unknown_chunk_ptr) PNGARG((png_structp));
1051#endif
1052#ifdef PNG_SETJMP_SUPPORTED
1053/* This must match the function definition in <setjmp.h>, and the
1054 * application must include this before png.h to obtain the definition
1055 * of jmp_buf.
1056 */
1057typedef void (PNGAPI *png_longjmp_ptr) PNGARG((jmp_buf, int));
1058#endif
1059
1060/* Transform masks for the high-level interface */
1061#define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */
1062#define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */
1063#define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */
1064#define PNG_TRANSFORM_PACKING 0x0004 /* read and write */
1065#define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */
1066#define PNG_TRANSFORM_EXPAND 0x0010 /* read only */
1067#define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */
1068#define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */
1069#define PNG_TRANSFORM_BGR 0x0080 /* read and write */
1070#define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */
1071#define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */
1072#define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */
1073#define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* write only */
1074/* Added to libpng-1.2.34 */
1075#define PNG_TRANSFORM_STRIP_FILLER_BEFORE PNG_TRANSFORM_STRIP_FILLER
1076#define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */
1077/* Added to libpng-1.4.0 */
1078#define PNG_TRANSFORM_GRAY_TO_RGB 0x2000 /* read only */
1079
1080/* Flags for MNG supported features */
1081#define PNG_FLAG_MNG_EMPTY_PLTE 0x01
1082#define PNG_FLAG_MNG_FILTER_64 0x04
1083#define PNG_ALL_MNG_FEATURES 0x05
1084
1085typedef png_voidp (*png_malloc_ptr) PNGARG((png_structp, png_alloc_size_t));
1086typedef void (*png_free_ptr) PNGARG((png_structp, png_voidp));
1087
1088/* The structure that holds the information to read and write PNG files.
1089 * The only people who need to care about what is inside of this are the
1090 * people who will be modifying the library for their own special needs.
1091 * It should NOT be accessed directly by an application, except to store
1092 * the jmp_buf.
1093 */
1094
1095struct png_struct_def
1096{
1097#ifdef PNG_SETJMP_SUPPORTED
1098 jmp_buf jmpbuf PNG_DEPSTRUCT; /* used in png_error */
1099 png_longjmp_ptr longjmp_fn PNG_DEPSTRUCT;/* setjmp non-local goto
1100 function. */
1101#endif
1102 png_error_ptr error_fn PNG_DEPSTRUCT; /* function for printing
1103 errors and aborting */
1104 png_error_ptr warning_fn PNG_DEPSTRUCT; /* function for printing
1105 warnings */
1106 png_voidp error_ptr PNG_DEPSTRUCT; /* user supplied struct for
1107 error functions */
1108 png_rw_ptr write_data_fn PNG_DEPSTRUCT; /* function for writing
1109 output data */
1110 png_rw_ptr read_data_fn PNG_DEPSTRUCT; /* function for reading
1111 input data */
1112 png_voidp io_ptr PNG_DEPSTRUCT; /* ptr to application struct
1113 for I/O functions */
1114
1115#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
1116 png_user_transform_ptr read_user_transform_fn PNG_DEPSTRUCT; /* user read
1117 transform */
1118#endif
1119
1120#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
1121 png_user_transform_ptr write_user_transform_fn PNG_DEPSTRUCT; /* user write
1122 transform */
1123#endif
1124
1125/* These were added in libpng-1.0.2 */
1126#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
1127#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
1128 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
1129 png_voidp user_transform_ptr PNG_DEPSTRUCT; /* user supplied struct
1130 for user transform */
1131 png_byte user_transform_depth PNG_DEPSTRUCT; /* bit depth of user
1132 transformed pixels */
1133 png_byte user_transform_channels PNG_DEPSTRUCT; /* channels in user
1134 transformed pixels */
1135#endif
1136#endif
1137
1138 png_uint_32 mode PNG_DEPSTRUCT; /* tells us where we are in
1139 the PNG file */
1140 png_uint_32 flags PNG_DEPSTRUCT; /* flags indicating various
1141 things to libpng */
1142 png_uint_32 transformations PNG_DEPSTRUCT; /* which transformations
1143 to perform */
1144
1145 z_stream zstream PNG_DEPSTRUCT; /* pointer to decompression
1146 structure (below) */
1147 png_bytep zbuf PNG_DEPSTRUCT; /* buffer for zlib */
1148 png_size_t zbuf_size PNG_DEPSTRUCT; /* size of zbuf */
1149 int zlib_level PNG_DEPSTRUCT; /* holds zlib compression level */
1150 int zlib_method PNG_DEPSTRUCT; /* holds zlib compression method */
1151 int zlib_window_bits PNG_DEPSTRUCT; /* holds zlib compression window
1152 bits */
1153 int zlib_mem_level PNG_DEPSTRUCT; /* holds zlib compression memory
1154 level */
1155 int zlib_strategy PNG_DEPSTRUCT; /* holds zlib compression
1156 strategy */
1157
1158 png_uint_32 width PNG_DEPSTRUCT; /* width of image in pixels */
1159 png_uint_32 height PNG_DEPSTRUCT; /* height of image in pixels */
1160 png_uint_32 num_rows PNG_DEPSTRUCT; /* number of rows in current pass */
1161 png_uint_32 usr_width PNG_DEPSTRUCT; /* width of row at start of write */
1162 png_size_t rowbytes PNG_DEPSTRUCT; /* size of row in bytes */
1163#if 0 /* Replaced with the following in libpng-1.4.1 */
1164 png_size_t irowbytes PNG_DEPSTRUCT;
1165#endif
1166/* Added in libpng-1.4.1 */
1167#ifdef PNG_USER_LIMITS_SUPPORTED
1168 /* Total memory that a zTXt, sPLT, iTXt, iCCP, or unknown chunk
1169 * can occupy when decompressed. 0 means unlimited.
1170 * We will change the typedef from png_size_t to png_alloc_size_t
1171 * in libpng-1.6.0
1172 */
1173 png_alloc_size_t user_chunk_malloc_max PNG_DEPSTRUCT;
1174#endif
1175 png_uint_32 iwidth PNG_DEPSTRUCT; /* width of current interlaced
1176 row in pixels */
1177 png_uint_32 row_number PNG_DEPSTRUCT; /* current row in interlace pass */
1178 png_bytep prev_row PNG_DEPSTRUCT; /* buffer to save previous
1179 (unfiltered) row */
1180 png_bytep row_buf PNG_DEPSTRUCT; /* buffer to save current
1181 (unfiltered) row */
1182 png_bytep sub_row PNG_DEPSTRUCT; /* buffer to save "sub" row
1183 when filtering */
1184 png_bytep up_row PNG_DEPSTRUCT; /* buffer to save "up" row
1185 when filtering */
1186 png_bytep avg_row PNG_DEPSTRUCT; /* buffer to save "avg" row
1187 when filtering */
1188 png_bytep paeth_row PNG_DEPSTRUCT; /* buffer to save "Paeth" row
1189 when filtering */
1190 png_row_info row_info PNG_DEPSTRUCT; /* used for transformation
1191 routines */
1192
1193 png_uint_32 idat_size PNG_DEPSTRUCT; /* current IDAT size for read */
1194 png_uint_32 crc PNG_DEPSTRUCT; /* current chunk CRC value */
1195 png_colorp palette PNG_DEPSTRUCT; /* palette from the input file */
1196 png_uint_16 num_palette PNG_DEPSTRUCT; /* number of color entries in
1197 palette */
1198 png_uint_16 num_trans PNG_DEPSTRUCT; /* number of transparency values */
1199 png_byte chunk_name[5] PNG_DEPSTRUCT; /* null-terminated name of current
1200 chunk */
1201 png_byte compression PNG_DEPSTRUCT; /* file compression type
1202 (always 0) */
1203 png_byte filter PNG_DEPSTRUCT; /* file filter type (always 0) */
1204 png_byte interlaced PNG_DEPSTRUCT; /* PNG_INTERLACE_NONE,
1205 PNG_INTERLACE_ADAM7 */
1206 png_byte pass PNG_DEPSTRUCT; /* current interlace pass (0 - 6) */
1207 png_byte do_filter PNG_DEPSTRUCT; /* row filter flags (see
1208 PNG_FILTER_ below ) */
1209 png_byte color_type PNG_DEPSTRUCT; /* color type of file */
1210 png_byte bit_depth PNG_DEPSTRUCT; /* bit depth of file */
1211 png_byte usr_bit_depth PNG_DEPSTRUCT; /* bit depth of users row */
1212 png_byte pixel_depth PNG_DEPSTRUCT; /* number of bits per pixel */
1213 png_byte channels PNG_DEPSTRUCT; /* number of channels in file */
1214 png_byte usr_channels PNG_DEPSTRUCT; /* channels at start of write */
1215 png_byte sig_bytes PNG_DEPSTRUCT; /* magic bytes read/written from
1216 start of file */
1217
1218#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
1219 png_uint_16 filler PNG_DEPSTRUCT; /* filler bytes for pixel
1220 expansion */
1221#endif
1222
1223#ifdef PNG_bKGD_SUPPORTED
1224 png_byte background_gamma_type PNG_DEPSTRUCT;
1225# ifdef PNG_FLOATING_POINT_SUPPORTED
1226 float background_gamma PNG_DEPSTRUCT;
1227# endif
1228 png_color_16 background PNG_DEPSTRUCT; /* background color in
1229 screen gamma space */
1230#ifdef PNG_READ_GAMMA_SUPPORTED
1231 png_color_16 background_1 PNG_DEPSTRUCT; /* background normalized
1232 to gamma 1.0 */
1233#endif
1234#endif /* PNG_bKGD_SUPPORTED */
1235
1236#ifdef PNG_WRITE_FLUSH_SUPPORTED
1237 png_flush_ptr output_flush_fn PNG_DEPSTRUCT; /* Function for flushing
1238 output */
1239 png_uint_32 flush_dist PNG_DEPSTRUCT; /* how many rows apart to flush,
1240 0 - no flush */
1241 png_uint_32 flush_rows PNG_DEPSTRUCT; /* number of rows written since
1242 last flush */
1243#endif
1244
1245#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1246 int gamma_shift PNG_DEPSTRUCT; /* number of "insignificant" bits
1247 16-bit gamma */
1248#ifdef PNG_FLOATING_POINT_SUPPORTED
1249 float gamma PNG_DEPSTRUCT; /* file gamma value */
1250 float screen_gamma PNG_DEPSTRUCT; /* screen gamma value
1251 (display_exponent) */
1252#endif
1253#endif
1254
1255#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1256 png_bytep gamma_table PNG_DEPSTRUCT; /* gamma table for 8-bit
1257 depth files */
1258 png_bytep gamma_from_1 PNG_DEPSTRUCT; /* converts from 1.0 to screen */
1259 png_bytep gamma_to_1 PNG_DEPSTRUCT; /* converts from file to 1.0 */
1260 png_uint_16pp gamma_16_table PNG_DEPSTRUCT; /* gamma table for 16-bit
1261 depth files */
1262 png_uint_16pp gamma_16_from_1 PNG_DEPSTRUCT; /* converts from 1.0 to
1263 screen */
1264 png_uint_16pp gamma_16_to_1 PNG_DEPSTRUCT; /* converts from file to 1.0 */
1265#endif
1266
1267#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_sBIT_SUPPORTED)
1268 png_color_8 sig_bit PNG_DEPSTRUCT; /* significant bits in each
1269 available channel */
1270#endif
1271
1272#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
1273 png_color_8 shift PNG_DEPSTRUCT; /* shift for significant bit
1274 tranformation */
1275#endif
1276
1277#if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \
1278 || defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1279 png_bytep trans_alpha PNG_DEPSTRUCT; /* alpha values for
1280 paletted files */
1281 png_color_16 trans_color PNG_DEPSTRUCT; /* transparent color for
1282 non-paletted files */
1283#endif
1284
1285 png_read_status_ptr read_row_fn PNG_DEPSTRUCT; /* called after each
1286 row is decoded */
1287 png_write_status_ptr write_row_fn PNG_DEPSTRUCT; /* called after each
1288 row is encoded */
1289#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1290 png_progressive_info_ptr info_fn PNG_DEPSTRUCT; /* called after header
1291 data fully read */
1292 png_progressive_row_ptr row_fn PNG_DEPSTRUCT; /* called after each
1293 prog. row is decoded */
1294 png_progressive_end_ptr end_fn PNG_DEPSTRUCT; /* called after image
1295 is complete */
1296 png_bytep save_buffer_ptr PNG_DEPSTRUCT; /* current location in
1297 save_buffer */
1298 png_bytep save_buffer PNG_DEPSTRUCT; /* buffer for previously
1299 read data */
1300 png_bytep current_buffer_ptr PNG_DEPSTRUCT; /* current location in
1301 current_buffer */
1302 png_bytep current_buffer PNG_DEPSTRUCT; /* buffer for recently
1303 used data */
1304 png_uint_32 push_length PNG_DEPSTRUCT; /* size of current input
1305 chunk */
1306 png_uint_32 skip_length PNG_DEPSTRUCT; /* bytes to skip in
1307 input data */
1308 png_size_t save_buffer_size PNG_DEPSTRUCT; /* amount of data now
1309 in save_buffer */
1310 png_size_t save_buffer_max PNG_DEPSTRUCT; /* total size of
1311 save_buffer */
1312 png_size_t buffer_size PNG_DEPSTRUCT; /* total amount of
1313 available input data */
1314 png_size_t current_buffer_size PNG_DEPSTRUCT; /* amount of data now
1315 in current_buffer */
1316 int process_mode PNG_DEPSTRUCT; /* what push library
1317 is currently doing */
1318 int cur_palette PNG_DEPSTRUCT; /* current push library
1319 palette index */
1320
1321# ifdef PNG_TEXT_SUPPORTED
1322 png_size_t current_text_size PNG_DEPSTRUCT; /* current size of
1323 text input data */
1324 png_size_t current_text_left PNG_DEPSTRUCT; /* how much text left
1325 to read in input */
1326 png_charp current_text PNG_DEPSTRUCT; /* current text chunk
1327 buffer */
1328 png_charp current_text_ptr PNG_DEPSTRUCT; /* current location
1329 in current_text */
1330# endif /* PNG_PROGRESSIVE_READ_SUPPORTED && PNG_TEXT_SUPPORTED */
1331
1332#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
1333
1334#if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
1335/* For the Borland special 64K segment handler */
1336 png_bytepp offset_table_ptr PNG_DEPSTRUCT;
1337 png_bytep offset_table PNG_DEPSTRUCT;
1338 png_uint_16 offset_table_number PNG_DEPSTRUCT;
1339 png_uint_16 offset_table_count PNG_DEPSTRUCT;
1340 png_uint_16 offset_table_count_free PNG_DEPSTRUCT;
1341#endif
1342
1343#ifdef PNG_READ_QUANTIZE_SUPPORTED
1344 png_bytep palette_lookup PNG_DEPSTRUCT; /* lookup table for quantizing */
1345 png_bytep quantize_index PNG_DEPSTRUCT; /* index translation for palette
1346 files */
1347#endif
1348
1349#if defined(PNG_READ_QUANTIZE_SUPPORTED) || defined(PNG_hIST_SUPPORTED)
1350 png_uint_16p hist PNG_DEPSTRUCT; /* histogram */
1351#endif
1352
1353#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
1354 png_byte heuristic_method PNG_DEPSTRUCT; /* heuristic for row
1355 filter selection */
1356 png_byte num_prev_filters PNG_DEPSTRUCT; /* number of weights
1357 for previous rows */
1358 png_bytep prev_filters PNG_DEPSTRUCT; /* filter type(s) of
1359 previous row(s) */
1360 png_uint_16p filter_weights PNG_DEPSTRUCT; /* weight(s) for previous
1361 line(s) */
1362 png_uint_16p inv_filter_weights PNG_DEPSTRUCT; /* 1/weight(s) for
1363 previous line(s) */
1364 png_uint_16p filter_costs PNG_DEPSTRUCT; /* relative filter
1365 calculation cost */
1366 png_uint_16p inv_filter_costs PNG_DEPSTRUCT; /* 1/relative filter
1367 calculation cost */
1368#endif
1369
1370#ifdef PNG_TIME_RFC1123_SUPPORTED
1371 png_charp time_buffer PNG_DEPSTRUCT; /* String to hold RFC 1123 time text */
1372#endif
1373
1374/* New members added in libpng-1.0.6 */
1375
1376 png_uint_32 free_me PNG_DEPSTRUCT; /* flags items libpng is
1377 responsible for freeing */
1378
1379#ifdef PNG_USER_CHUNKS_SUPPORTED
1380 png_voidp user_chunk_ptr PNG_DEPSTRUCT;
1381 png_user_chunk_ptr read_user_chunk_fn PNG_DEPSTRUCT; /* user read
1382 chunk handler */
1383#endif
1384
1385#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
1386 int num_chunk_list PNG_DEPSTRUCT;
1387 png_bytep chunk_list PNG_DEPSTRUCT;
1388#endif
1389
1390/* New members added in libpng-1.0.3 */
1391#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1392 png_byte rgb_to_gray_status PNG_DEPSTRUCT;
1393 /* These were changed from png_byte in libpng-1.0.6 */
1394 png_uint_16 rgb_to_gray_red_coeff PNG_DEPSTRUCT;
1395 png_uint_16 rgb_to_gray_green_coeff PNG_DEPSTRUCT;
1396 png_uint_16 rgb_to_gray_blue_coeff PNG_DEPSTRUCT;
1397#endif
1398
1399/* New member added in libpng-1.0.4 (renamed in 1.0.9) */
1400#if defined(PNG_MNG_FEATURES_SUPPORTED) || \
1401 defined(PNG_READ_EMPTY_PLTE_SUPPORTED) || \
1402 defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
1403/* Changed from png_byte to png_uint_32 at version 1.2.0 */
1404 png_uint_32 mng_features_permitted PNG_DEPSTRUCT;
1405#endif
1406
1407/* New member added in libpng-1.0.7 */
1408#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1409 png_fixed_point int_gamma PNG_DEPSTRUCT;
1410#endif
1411
1412/* New member added in libpng-1.0.9, ifdef'ed out in 1.0.12, enabled in 1.2.0 */
1413#ifdef PNG_MNG_FEATURES_SUPPORTED
1414 png_byte filter_type PNG_DEPSTRUCT;
1415#endif
1416
1417/* New members added in libpng-1.2.0 */
1418
1419/* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */
1420#ifdef PNG_USER_MEM_SUPPORTED
1421 png_voidp mem_ptr PNG_DEPSTRUCT; /* user supplied struct for
1422 mem functions */
1423 png_malloc_ptr malloc_fn PNG_DEPSTRUCT; /* function for
1424 allocating memory */
1425 png_free_ptr free_fn PNG_DEPSTRUCT; /* function for
1426 freeing memory */
1427#endif
1428
1429/* New member added in libpng-1.0.13 and 1.2.0 */
1430 png_bytep big_row_buf PNG_DEPSTRUCT; /* buffer to save current
1431 (unfiltered) row */
1432
1433#ifdef PNG_READ_QUANTIZE_SUPPORTED
1434/* The following three members were added at version 1.0.14 and 1.2.4 */
1435 png_bytep quantize_sort PNG_DEPSTRUCT; /* working sort array */
1436 png_bytep index_to_palette PNG_DEPSTRUCT; /* where the original
1437 index currently is
1438 in the palette */
1439 png_bytep palette_to_index PNG_DEPSTRUCT; /* which original index
1440 points to this
1441 palette color */
1442#endif
1443
1444/* New members added in libpng-1.0.16 and 1.2.6 */
1445 png_byte compression_type PNG_DEPSTRUCT;
1446
1447#ifdef PNG_USER_LIMITS_SUPPORTED
1448 png_uint_32 user_width_max PNG_DEPSTRUCT;
1449 png_uint_32 user_height_max PNG_DEPSTRUCT;
1450 /* Added in libpng-1.4.0: Total number of sPLT, text, and unknown
1451 * chunks that can be stored (0 means unlimited).
1452 */
1453 png_uint_32 user_chunk_cache_max PNG_DEPSTRUCT;
1454#endif
1455
1456/* New member added in libpng-1.0.25 and 1.2.17 */
1457#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
1458 /* Storage for unknown chunk that the library doesn't recognize. */
1459 png_unknown_chunk unknown_chunk PNG_DEPSTRUCT;
1460#endif
1461
1462/* New members added in libpng-1.2.26 */
1463 png_uint_32 old_big_row_buf_size PNG_DEPSTRUCT;
1464 png_uint_32 old_prev_row_size PNG_DEPSTRUCT;
1465
1466/* New member added in libpng-1.2.30 */
1467 png_charp chunkdata PNG_DEPSTRUCT; /* buffer for reading chunk data */
1468
1469#ifdef PNG_IO_STATE_SUPPORTED
1470/* New member added in libpng-1.4.0 */
1471 png_uint_32 io_state PNG_DEPSTRUCT;
1472#endif
1473};
1474
1475
1476/* This triggers a compiler error in png.c, if png.c and png.h
1477 * do not agree upon the version number.
1478 */
1479typedef png_structp version_1_4_4;
1480
1481typedef png_struct FAR * FAR * png_structpp;
1482
1483/* Here are the function definitions most commonly used. This is not
1484 * the place to find out how to use libpng. See libpng.txt for the
1485 * full explanation, see example.c for the summary. This just provides
1486 * a simple one line description of the use of each function.
1487 */
1488
1489/* Returns the version number of the library */
1490PNG_EXPORT(png_uint_32,png_access_version_number) PNGARG((void));
1491
1492/* Tell lib we have already handled the first <num_bytes> magic bytes.
1493 * Handling more than 8 bytes from the beginning of the file is an error.
1494 */
1495PNG_EXPORT(void,png_set_sig_bytes) PNGARG((png_structp png_ptr,
1496 int num_bytes));
1497
1498/* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
1499 * PNG file. Returns zero if the supplied bytes match the 8-byte PNG
1500 * signature, and non-zero otherwise. Having num_to_check == 0 or
1501 * start > 7 will always fail (ie return non-zero).
1502 */
1503PNG_EXPORT(int,png_sig_cmp) PNGARG((png_bytep sig, png_size_t start,
1504 png_size_t num_to_check));
1505
1506/* Simple signature checking function. This is the same as calling
1507 * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n).
1508 */
1509#define png_check_sig(sig,n) !png_sig_cmp((sig), 0, (n))
1510
1511/* Allocate and initialize png_ptr struct for reading, and any other memory. */
1512PNG_EXPORT(png_structp,png_create_read_struct)
1513 PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1514 png_error_ptr error_fn, png_error_ptr warn_fn)) PNG_ALLOCATED;
1515
1516/* Allocate and initialize png_ptr struct for writing, and any other memory */
1517PNG_EXPORT(png_structp,png_create_write_struct)
1518 PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1519 png_error_ptr error_fn, png_error_ptr warn_fn)) PNG_ALLOCATED;
1520
1521PNG_EXPORT(png_size_t,png_get_compression_buffer_size)
1522 PNGARG((png_structp png_ptr));
1523
1524PNG_EXPORT(void,png_set_compression_buffer_size)
1525 PNGARG((png_structp png_ptr, png_size_t size));
1526
1527/* Moved from pngconf.h in 1.4.0 and modified to ensure setjmp/longjmp
1528 * match up.
1529 */
1530#ifdef PNG_SETJMP_SUPPORTED
1531/* This function returns the jmp_buf built in to *png_ptr. It must be
1532 * supplied with an appropriate 'longjmp' function to use on that jmp_buf
1533 * unless the default error function is overridden in which case NULL is
1534 * acceptable. The size of the jmp_buf is checked against the actual size
1535 * allocated by the library - the call will return NULL on a mismatch
1536 * indicating an ABI mismatch.
1537 */
1538PNG_EXPORT(jmp_buf*, png_set_longjmp_fn)
1539 PNGARG((png_structp png_ptr, png_longjmp_ptr longjmp_fn, size_t
1540 jmp_buf_size));
1541# define png_jmpbuf(png_ptr) \
1542 (*png_set_longjmp_fn((png_ptr), longjmp, sizeof (jmp_buf)))
1543#else
1544# define png_jmpbuf(png_ptr) \
1545 (LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP)
1546#endif
1547
1548#ifdef PNG_READ_SUPPORTED
1549/* Reset the compression stream */
1550PNG_EXPORT(int,png_reset_zstream) PNGARG((png_structp png_ptr));
1551#endif
1552
1553/* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */
1554#ifdef PNG_USER_MEM_SUPPORTED
1555PNG_EXPORT(png_structp,png_create_read_struct_2)
1556 PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1557 png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
1558 png_malloc_ptr malloc_fn, png_free_ptr free_fn)) PNG_ALLOCATED;
1559PNG_EXPORT(png_structp,png_create_write_struct_2)
1560 PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1561 png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
1562 png_malloc_ptr malloc_fn, png_free_ptr free_fn)) PNG_ALLOCATED;
1563#endif
1564
1565/* Write the PNG file signature. */
1566PNG_EXPORT(void,png_write_sig) PNGARG((png_structp png_ptr));
1567
1568/* Write a PNG chunk - size, type, (optional) data, CRC. */
1569PNG_EXPORT(void,png_write_chunk) PNGARG((png_structp png_ptr,
1570 png_bytep chunk_name, png_bytep data, png_size_t length));
1571
1572/* Write the start of a PNG chunk - length and chunk name. */
1573PNG_EXPORT(void,png_write_chunk_start) PNGARG((png_structp png_ptr,
1574 png_bytep chunk_name, png_uint_32 length));
1575
1576/* Write the data of a PNG chunk started with png_write_chunk_start(). */
1577PNG_EXPORT(void,png_write_chunk_data) PNGARG((png_structp png_ptr,
1578 png_bytep data, png_size_t length));
1579
1580/* Finish a chunk started with png_write_chunk_start() (includes CRC). */
1581PNG_EXPORT(void,png_write_chunk_end) PNGARG((png_structp png_ptr));
1582
1583/* Allocate and initialize the info structure */
1584PNG_EXPORT(png_infop,png_create_info_struct)
1585 PNGARG((png_structp png_ptr)) PNG_ALLOCATED;
1586
1587PNG_EXPORT(void,png_info_init_3) PNGARG((png_infopp info_ptr,
1588 png_size_t png_info_struct_size));
1589
1590/* Writes all the PNG information before the image. */
1591PNG_EXPORT(void,png_write_info_before_PLTE) PNGARG((png_structp png_ptr,
1592 png_infop info_ptr));
1593PNG_EXPORT(void,png_write_info) PNGARG((png_structp png_ptr,
1594 png_infop info_ptr));
1595
1596#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1597/* Read the information before the actual image data. */
1598PNG_EXPORT(void,png_read_info) PNGARG((png_structp png_ptr,
1599 png_infop info_ptr));
1600#endif
1601
1602#ifdef PNG_TIME_RFC1123_SUPPORTED
1603PNG_EXPORT(png_charp,png_convert_to_rfc1123)
1604 PNGARG((png_structp png_ptr, png_timep ptime));
1605#endif
1606
1607#ifdef PNG_CONVERT_tIME_SUPPORTED
1608/* Convert from a struct tm to png_time */
1609PNG_EXPORT(void,png_convert_from_struct_tm) PNGARG((png_timep ptime,
1610 struct tm FAR * ttime));
1611
1612/* Convert from time_t to png_time. Uses gmtime() */
1613PNG_EXPORT(void,png_convert_from_time_t) PNGARG((png_timep ptime,
1614 time_t ttime));
1615#endif /* PNG_CONVERT_tIME_SUPPORTED */
1616
1617#ifdef PNG_READ_EXPAND_SUPPORTED
1618/* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
1619PNG_EXPORT(void,png_set_expand) PNGARG((png_structp png_ptr));
1620PNG_EXPORT(void,png_set_expand_gray_1_2_4_to_8) PNGARG((png_structp
1621 png_ptr));
1622PNG_EXPORT(void,png_set_palette_to_rgb) PNGARG((png_structp png_ptr));
1623PNG_EXPORT(void,png_set_tRNS_to_alpha) PNGARG((png_structp png_ptr));
1624#endif
1625
1626#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
1627/* Use blue, green, red order for pixels. */
1628PNG_EXPORT(void,png_set_bgr) PNGARG((png_structp png_ptr));
1629#endif
1630
1631#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
1632/* Expand the grayscale to 24-bit RGB if necessary. */
1633PNG_EXPORT(void,png_set_gray_to_rgb) PNGARG((png_structp png_ptr));
1634#endif
1635
1636#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1637/* Reduce RGB to grayscale. */
1638#ifdef PNG_FLOATING_POINT_SUPPORTED
1639PNG_EXPORT(void,png_set_rgb_to_gray) PNGARG((png_structp png_ptr,
1640 int error_action, double red, double green ));
1641#endif
1642PNG_EXPORT(void,png_set_rgb_to_gray_fixed) PNGARG((png_structp png_ptr,
1643 int error_action, png_fixed_point red, png_fixed_point green ));
1644PNG_EXPORT(png_byte,png_get_rgb_to_gray_status) PNGARG((png_structp
1645 png_ptr));
1646#endif
1647
1648PNG_EXPORT(void,png_build_grayscale_palette) PNGARG((int bit_depth,
1649 png_colorp palette));
1650
1651#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
1652PNG_EXPORT(void,png_set_strip_alpha) PNGARG((png_structp png_ptr));
1653#endif
1654
1655#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
1656 defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
1657PNG_EXPORT(void,png_set_swap_alpha) PNGARG((png_structp png_ptr));
1658#endif
1659
1660#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
1661 defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
1662PNG_EXPORT(void,png_set_invert_alpha) PNGARG((png_structp png_ptr));
1663#endif
1664
1665#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
1666/* Add a filler byte to 8-bit Gray or 24-bit RGB images. */
1667PNG_EXPORT(void,png_set_filler) PNGARG((png_structp png_ptr,
1668 png_uint_32 filler, int flags));
1669/* The values of the PNG_FILLER_ defines should NOT be changed */
1670#define PNG_FILLER_BEFORE 0
1671#define PNG_FILLER_AFTER 1
1672/* Add an alpha byte to 8-bit Gray or 24-bit RGB images. */
1673PNG_EXPORT(void,png_set_add_alpha) PNGARG((png_structp png_ptr,
1674 png_uint_32 filler, int flags));
1675#endif /* PNG_READ_FILLER_SUPPORTED || PNG_WRITE_FILLER_SUPPORTED */
1676
1677#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
1678/* Swap bytes in 16-bit depth files. */
1679PNG_EXPORT(void,png_set_swap) PNGARG((png_structp png_ptr));
1680#endif
1681
1682#if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
1683/* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
1684PNG_EXPORT(void,png_set_packing) PNGARG((png_structp png_ptr));
1685#endif
1686
1687#if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
1688 defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1689/* Swap packing order of pixels in bytes. */
1690PNG_EXPORT(void,png_set_packswap) PNGARG((png_structp png_ptr));
1691#endif
1692
1693#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
1694/* Converts files to legal bit depths. */
1695PNG_EXPORT(void,png_set_shift) PNGARG((png_structp png_ptr,
1696 png_color_8p true_bits));
1697#endif
1698
1699#if defined(PNG_READ_INTERLACING_SUPPORTED) || \
1700 defined(PNG_WRITE_INTERLACING_SUPPORTED)
1701/* Have the code handle the interlacing. Returns the number of passes. */
1702PNG_EXPORT(int,png_set_interlace_handling) PNGARG((png_structp png_ptr));
1703#endif
1704
1705#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
1706/* Invert monochrome files */
1707PNG_EXPORT(void,png_set_invert_mono) PNGARG((png_structp png_ptr));
1708#endif
1709
1710#ifdef PNG_READ_BACKGROUND_SUPPORTED
1711/* Handle alpha and tRNS by replacing with a background color. */
1712#ifdef PNG_FLOATING_POINT_SUPPORTED
1713PNG_EXPORT(void,png_set_background) PNGARG((png_structp png_ptr,
1714 png_color_16p background_color, int background_gamma_code,
1715 int need_expand, double background_gamma));
1716#endif
1717#define PNG_BACKGROUND_GAMMA_UNKNOWN 0
1718#define PNG_BACKGROUND_GAMMA_SCREEN 1
1719#define PNG_BACKGROUND_GAMMA_FILE 2
1720#define PNG_BACKGROUND_GAMMA_UNIQUE 3
1721#endif
1722
1723#ifdef PNG_READ_16_TO_8_SUPPORTED
1724/* Strip the second byte of information from a 16-bit depth file. */
1725PNG_EXPORT(void,png_set_strip_16) PNGARG((png_structp png_ptr));
1726#endif
1727
1728#ifdef PNG_READ_QUANTIZE_SUPPORTED
1729/* Turn on quantizing, and reduce the palette to the number of colors
1730 * available. Prior to libpng-1.4.2, this was png_set_dither().
1731 */
1732PNG_EXPORT(void,png_set_quantize) PNGARG((png_structp png_ptr,
1733 png_colorp palette, int num_palette, int maximum_colors,
1734 png_uint_16p histogram, int full_quantize));
1735#endif
1736/* This migration aid will be removed from libpng-1.5.0 */
1737#define png_set_dither png_set_quantize
1738
1739#ifdef PNG_READ_GAMMA_SUPPORTED
1740/* Handle gamma correction. Screen_gamma=(display_exponent) */
1741#ifdef PNG_FLOATING_POINT_SUPPORTED
1742PNG_EXPORT(void,png_set_gamma) PNGARG((png_structp png_ptr,
1743 double screen_gamma, double default_file_gamma));
1744#endif
1745#endif
1746
1747
1748#ifdef PNG_WRITE_FLUSH_SUPPORTED
1749/* Set how many lines between output flushes - 0 for no flushing */
1750PNG_EXPORT(void,png_set_flush) PNGARG((png_structp png_ptr, int nrows));
1751/* Flush the current PNG output buffer */
1752PNG_EXPORT(void,png_write_flush) PNGARG((png_structp png_ptr));
1753#endif
1754
1755/* Optional update palette with requested transformations */
1756PNG_EXPORT(void,png_start_read_image) PNGARG((png_structp png_ptr));
1757
1758/* Optional call to update the users info structure */
1759PNG_EXPORT(void,png_read_update_info) PNGARG((png_structp png_ptr,
1760 png_infop info_ptr));
1761
1762#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1763/* Read one or more rows of image data. */
1764PNG_EXPORT(void,png_read_rows) PNGARG((png_structp png_ptr,
1765 png_bytepp row, png_bytepp display_row, png_uint_32 num_rows));
1766#endif
1767
1768#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1769/* Read a row of data. */
1770PNG_EXPORT(void,png_read_row) PNGARG((png_structp png_ptr,
1771 png_bytep row,
1772 png_bytep display_row));
1773#endif
1774
1775#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1776/* Read the whole image into memory at once. */
1777PNG_EXPORT(void,png_read_image) PNGARG((png_structp png_ptr,
1778 png_bytepp image));
1779#endif
1780
1781/* Write a row of image data */
1782PNG_EXPORT(void,png_write_row) PNGARG((png_structp png_ptr,
1783 png_bytep row));
1784
1785/* Write a few rows of image data */
1786PNG_EXPORT(void,png_write_rows) PNGARG((png_structp png_ptr,
1787 png_bytepp row, png_uint_32 num_rows));
1788
1789/* Write the image data */
1790PNG_EXPORT(void,png_write_image) PNGARG((png_structp png_ptr,
1791 png_bytepp image));
1792
1793/* Write the end of the PNG file. */
1794PNG_EXPORT(void,png_write_end) PNGARG((png_structp png_ptr,
1795 png_infop info_ptr));
1796
1797#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1798/* Read the end of the PNG file. */
1799PNG_EXPORT(void,png_read_end) PNGARG((png_structp png_ptr,
1800 png_infop info_ptr));
1801#endif
1802
1803/* Free any memory associated with the png_info_struct */
1804PNG_EXPORT(void,png_destroy_info_struct) PNGARG((png_structp png_ptr,
1805 png_infopp info_ptr_ptr));
1806
1807/* Free any memory associated with the png_struct and the png_info_structs */
1808PNG_EXPORT(void,png_destroy_read_struct) PNGARG((png_structpp
1809 png_ptr_ptr, png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr));
1810
1811/* Free any memory associated with the png_struct and the png_info_structs */
1812PNG_EXPORT(void,png_destroy_write_struct)
1813 PNGARG((png_structpp png_ptr_ptr, png_infopp info_ptr_ptr));
1814
1815/* Set the libpng method of handling chunk CRC errors */
1816PNG_EXPORT(void,png_set_crc_action) PNGARG((png_structp png_ptr,
1817 int crit_action, int ancil_action));
1818
1819/* Values for png_set_crc_action() to say how to handle CRC errors in
1820 * ancillary and critical chunks, and whether to use the data contained
1821 * therein. Note that it is impossible to "discard" data in a critical
1822 * chunk. For versions prior to 0.90, the action was always error/quit,
1823 * whereas in version 0.90 and later, the action for CRC errors in ancillary
1824 * chunks is warn/discard. These values should NOT be changed.
1825 *
1826 * value action:critical action:ancillary
1827 */
1828#define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */
1829#define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */
1830#define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */
1831#define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */
1832#define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */
1833#define PNG_CRC_NO_CHANGE 5 /* use current value use current value */
1834
1835/* These functions give the user control over the scan-line filtering in
1836 * libpng and the compression methods used by zlib. These functions are
1837 * mainly useful for testing, as the defaults should work with most users.
1838 * Those users who are tight on memory or want faster performance at the
1839 * expense of compression can modify them. See the compression library
1840 * header file (zlib.h) for an explination of the compression functions.
1841 */
1842
1843/* Set the filtering method(s) used by libpng. Currently, the only valid
1844 * value for "method" is 0.
1845 */
1846PNG_EXPORT(void,png_set_filter) PNGARG((png_structp png_ptr, int method,
1847 int filters));
1848
1849/* Flags for png_set_filter() to say which filters to use. The flags
1850 * are chosen so that they don't conflict with real filter types
1851 * below, in case they are supplied instead of the #defined constants.
1852 * These values should NOT be changed.
1853 */
1854#define PNG_NO_FILTERS 0x00
1855#define PNG_FILTER_NONE 0x08
1856#define PNG_FILTER_SUB 0x10
1857#define PNG_FILTER_UP 0x20
1858#define PNG_FILTER_AVG 0x40
1859#define PNG_FILTER_PAETH 0x80
1860#define PNG_ALL_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP | \
1861 PNG_FILTER_AVG | PNG_FILTER_PAETH)
1862
1863/* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
1864 * These defines should NOT be changed.
1865 */
1866#define PNG_FILTER_VALUE_NONE 0
1867#define PNG_FILTER_VALUE_SUB 1
1868#define PNG_FILTER_VALUE_UP 2
1869#define PNG_FILTER_VALUE_AVG 3
1870#define PNG_FILTER_VALUE_PAETH 4
1871#define PNG_FILTER_VALUE_LAST 5
1872
1873#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* EXPERIMENTAL */
1874/* The "heuristic_method" is given by one of the PNG_FILTER_HEURISTIC_
1875 * defines, either the default (minimum-sum-of-absolute-differences), or
1876 * the experimental method (weighted-minimum-sum-of-absolute-differences).
1877 *
1878 * Weights are factors >= 1.0, indicating how important it is to keep the
1879 * filter type consistent between rows. Larger numbers mean the current
1880 * filter is that many times as likely to be the same as the "num_weights"
1881 * previous filters. This is cumulative for each previous row with a weight.
1882 * There needs to be "num_weights" values in "filter_weights", or it can be
1883 * NULL if the weights aren't being specified. Weights have no influence on
1884 * the selection of the first row filter. Well chosen weights can (in theory)
1885 * improve the compression for a given image.
1886 *
1887 * Costs are factors >= 1.0 indicating the relative decoding costs of a
1888 * filter type. Higher costs indicate more decoding expense, and are
1889 * therefore less likely to be selected over a filter with lower computational
1890 * costs. There needs to be a value in "filter_costs" for each valid filter
1891 * type (given by PNG_FILTER_VALUE_LAST), or it can be NULL if you aren't
1892 * setting the costs. Costs try to improve the speed of decompression without
1893 * unduly increasing the compressed image size.
1894 *
1895 * A negative weight or cost indicates the default value is to be used, and
1896 * values in the range [0.0, 1.0) indicate the value is to remain unchanged.
1897 * The default values for both weights and costs are currently 1.0, but may
1898 * change if good general weighting/cost heuristics can be found. If both
1899 * the weights and costs are set to 1.0, this degenerates the WEIGHTED method
1900 * to the UNWEIGHTED method, but with added encoding time/computation.
1901 */
1902#ifdef PNG_FLOATING_POINT_SUPPORTED
1903PNG_EXPORT(void,png_set_filter_heuristics) PNGARG((png_structp png_ptr,
1904 int heuristic_method, int num_weights, png_doublep filter_weights,
1905 png_doublep filter_costs));
1906#endif
1907#endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
1908
1909/* Heuristic used for row filter selection. These defines should NOT be
1910 * changed.
1911 */
1912#define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */
1913#define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */
1914#define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */
1915#define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */
1916
1917/* Set the library compression level. Currently, valid values range from
1918 * 0 - 9, corresponding directly to the zlib compression levels 0 - 9
1919 * (0 - no compression, 9 - "maximal" compression). Note that tests have
1920 * shown that zlib compression levels 3-6 usually perform as well as level 9
1921 * for PNG images, and do considerably fewer caclulations. In the future,
1922 * these values may not correspond directly to the zlib compression levels.
1923 */
1924PNG_EXPORT(void,png_set_compression_level) PNGARG((png_structp png_ptr,
1925 int level));
1926
1927PNG_EXPORT(void,png_set_compression_mem_level)
1928 PNGARG((png_structp png_ptr, int mem_level));
1929
1930PNG_EXPORT(void,png_set_compression_strategy)
1931 PNGARG((png_structp png_ptr, int strategy));
1932
1933PNG_EXPORT(void,png_set_compression_window_bits)
1934 PNGARG((png_structp png_ptr, int window_bits));
1935
1936PNG_EXPORT(void,png_set_compression_method) PNGARG((png_structp png_ptr,
1937 int method));
1938
1939/* These next functions are called for input/output, memory, and error
1940 * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c,
1941 * and call standard C I/O routines such as fread(), fwrite(), and
1942 * fprintf(). These functions can be made to use other I/O routines
1943 * at run time for those applications that need to handle I/O in a
1944 * different manner by calling png_set_???_fn(). See libpng.txt for
1945 * more information.
1946 */
1947
1948#ifdef PNG_STDIO_SUPPORTED
1949/* Initialize the input/output for the PNG file to the default functions. */
1950PNG_EXPORT(void,png_init_io) PNGARG((png_structp png_ptr,
1951 png_FILE_p fp));
1952#endif
1953
1954/* Replace the (error and abort), and warning functions with user
1955 * supplied functions. If no messages are to be printed you must still
1956 * write and use replacement functions. The replacement error_fn should
1957 * still do a longjmp to the last setjmp location if you are using this
1958 * method of error handling. If error_fn or warning_fn is NULL, the
1959 * default function will be used.
1960 */
1961
1962PNG_EXPORT(void,png_set_error_fn) PNGARG((png_structp png_ptr,
1963 png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn));
1964
1965/* Return the user pointer associated with the error functions */
1966PNG_EXPORT(png_voidp,png_get_error_ptr) PNGARG((png_structp png_ptr));
1967
1968/* Replace the default data output functions with a user supplied one(s).
1969 * If buffered output is not used, then output_flush_fn can be set to NULL.
1970 * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time
1971 * output_flush_fn will be ignored (and thus can be NULL).
1972 * It is probably a mistake to use NULL for output_flush_fn if
1973 * write_data_fn is not also NULL unless you have built libpng with
1974 * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's
1975 * default flush function, which uses the standard *FILE structure, will
1976 * be used.
1977 */
1978PNG_EXPORT(void,png_set_write_fn) PNGARG((png_structp png_ptr,
1979 png_voidp io_ptr, png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn));
1980
1981/* Replace the default data input function with a user supplied one. */
1982PNG_EXPORT(void,png_set_read_fn) PNGARG((png_structp png_ptr,
1983 png_voidp io_ptr, png_rw_ptr read_data_fn));
1984
1985/* Return the user pointer associated with the I/O functions */
1986PNG_EXPORT(png_voidp,png_get_io_ptr) PNGARG((png_structp png_ptr));
1987
1988PNG_EXPORT(void,png_set_read_status_fn) PNGARG((png_structp png_ptr,
1989 png_read_status_ptr read_row_fn));
1990
1991PNG_EXPORT(void,png_set_write_status_fn) PNGARG((png_structp png_ptr,
1992 png_write_status_ptr write_row_fn));
1993
1994#ifdef PNG_USER_MEM_SUPPORTED
1995/* Replace the default memory allocation functions with user supplied one(s). */
1996PNG_EXPORT(void,png_set_mem_fn) PNGARG((png_structp png_ptr,
1997 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn));
1998/* Return the user pointer associated with the memory functions */
1999PNG_EXPORT(png_voidp,png_get_mem_ptr) PNGARG((png_structp png_ptr));
2000#endif
2001
2002#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
2003PNG_EXPORT(void,png_set_read_user_transform_fn) PNGARG((png_structp
2004 png_ptr, png_user_transform_ptr read_user_transform_fn));
2005#endif
2006
2007#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
2008PNG_EXPORT(void,png_set_write_user_transform_fn) PNGARG((png_structp
2009 png_ptr, png_user_transform_ptr write_user_transform_fn));
2010#endif
2011
2012#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
2013 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
2014PNG_EXPORT(void,png_set_user_transform_info) PNGARG((png_structp
2015 png_ptr, png_voidp user_transform_ptr, int user_transform_depth,
2016 int user_transform_channels));
2017/* Return the user pointer associated with the user transform functions */
2018PNG_EXPORT(png_voidp,png_get_user_transform_ptr)
2019 PNGARG((png_structp png_ptr));
2020#endif
2021
2022#ifdef PNG_USER_CHUNKS_SUPPORTED
2023PNG_EXPORT(void,png_set_read_user_chunk_fn) PNGARG((png_structp png_ptr,
2024 png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));
2025PNG_EXPORT(png_voidp,png_get_user_chunk_ptr) PNGARG((png_structp
2026 png_ptr));
2027#endif
2028
2029#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
2030/* Sets the function callbacks for the push reader, and a pointer to a
2031 * user-defined structure available to the callback functions.
2032 */
2033PNG_EXPORT(void,png_set_progressive_read_fn) PNGARG((png_structp png_ptr,
2034 png_voidp progressive_ptr,
2035 png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
2036 png_progressive_end_ptr end_fn));
2037
2038/* Returns the user pointer associated with the push read functions */
2039PNG_EXPORT(png_voidp,png_get_progressive_ptr)
2040 PNGARG((png_structp png_ptr));
2041
2042/* Function to be called when data becomes available */
2043PNG_EXPORT(void,png_process_data) PNGARG((png_structp png_ptr,
2044 png_infop info_ptr, png_bytep buffer, png_size_t buffer_size));
2045
2046/* Function that combines rows. Not very much different than the
2047 * png_combine_row() call. Is this even used?????
2048 */
2049PNG_EXPORT(void,png_progressive_combine_row) PNGARG((png_structp png_ptr,
2050 png_bytep old_row, png_bytep new_row));
2051#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
2052
2053PNG_EXPORT(png_voidp,png_malloc) PNGARG((png_structp png_ptr,
2054 png_alloc_size_t size)) PNG_ALLOCATED;
2055/* Added at libpng version 1.4.0 */
2056PNG_EXPORT(png_voidp,png_calloc) PNGARG((png_structp png_ptr,
2057 png_alloc_size_t size)) PNG_ALLOCATED;
2058
2059/* Added at libpng version 1.2.4 */
2060PNG_EXPORT(png_voidp,png_malloc_warn) PNGARG((png_structp png_ptr,
2061 png_alloc_size_t size)) PNG_ALLOCATED;
2062
2063/* Frees a pointer allocated by png_malloc() */
2064PNG_EXPORT(void,png_free) PNGARG((png_structp png_ptr, png_voidp ptr));
2065
2066/* Free data that was allocated internally */
2067PNG_EXPORT(void,png_free_data) PNGARG((png_structp png_ptr,
2068 png_infop info_ptr, png_uint_32 free_me, int num));
2069/* Reassign responsibility for freeing existing data, whether allocated
2070 * by libpng or by the application */
2071PNG_EXPORT(void,png_data_freer) PNGARG((png_structp png_ptr,
2072 png_infop info_ptr, int freer, png_uint_32 mask));
2073/* Assignments for png_data_freer */
2074#define PNG_DESTROY_WILL_FREE_DATA 1
2075#define PNG_SET_WILL_FREE_DATA 1
2076#define PNG_USER_WILL_FREE_DATA 2
2077/* Flags for png_ptr->free_me and info_ptr->free_me */
2078#define PNG_FREE_HIST 0x0008
2079#define PNG_FREE_ICCP 0x0010
2080#define PNG_FREE_SPLT 0x0020
2081#define PNG_FREE_ROWS 0x0040
2082#define PNG_FREE_PCAL 0x0080
2083#define PNG_FREE_SCAL 0x0100
2084#define PNG_FREE_UNKN 0x0200
2085#define PNG_FREE_LIST 0x0400
2086#define PNG_FREE_PLTE 0x1000
2087#define PNG_FREE_TRNS 0x2000
2088#define PNG_FREE_TEXT 0x4000
2089#define PNG_FREE_ALL 0x7fff
2090#define PNG_FREE_MUL 0x4220 /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */
2091
2092#ifdef PNG_USER_MEM_SUPPORTED
2093PNG_EXPORT(png_voidp,png_malloc_default) PNGARG((png_structp png_ptr,
2094 png_alloc_size_t size)) PNG_ALLOCATED;
2095PNG_EXPORT(void,png_free_default) PNGARG((png_structp png_ptr,
2096 png_voidp ptr));
2097#endif
2098
2099#ifndef PNG_NO_ERROR_TEXT
2100/* Fatal error in PNG image of libpng - can't continue */
2101PNG_EXPORT(void,png_error) PNGARG((png_structp png_ptr,
2102 png_const_charp error_message)) PNG_NORETURN;
2103
2104/* The same, but the chunk name is prepended to the error string. */
2105PNG_EXPORT(void,png_chunk_error) PNGARG((png_structp png_ptr,
2106 png_const_charp error_message)) PNG_NORETURN;
2107
2108#else
2109/* Fatal error in PNG image of libpng - can't continue */
2110PNG_EXPORT(void,png_err) PNGARG((png_structp png_ptr)) PNG_NORETURN;
2111#endif
2112
2113/* Non-fatal error in libpng. Can continue, but may have a problem. */
2114PNG_EXPORT(void,png_warning) PNGARG((png_structp png_ptr,
2115 png_const_charp warning_message));
2116
2117/* Non-fatal error in libpng, chunk name is prepended to message. */
2118PNG_EXPORT(void,png_chunk_warning) PNGARG((png_structp png_ptr,
2119 png_const_charp warning_message));
2120
2121#ifdef PNG_BENIGN_ERRORS_SUPPORTED
2122/* Benign error in libpng. Can continue, but may have a problem.
2123 * User can choose whether to handle as a fatal error or as a warning. */
2124PNG_EXPORT(void,png_benign_error) PNGARG((png_structp png_ptr,
2125 png_const_charp warning_message));
2126
2127/* Same, chunk name is prepended to message. */
2128PNG_EXPORT(void,png_chunk_benign_error) PNGARG((png_structp png_ptr,
2129 png_const_charp warning_message));
2130
2131PNG_EXPORT(void,png_set_benign_errors) PNGARG((png_structp
2132 png_ptr, int allowed));
2133#endif
2134
2135/* The png_set_<chunk> functions are for storing values in the png_info_struct.
2136 * Similarly, the png_get_<chunk> calls are used to read values from the
2137 * png_info_struct, either storing the parameters in the passed variables, or
2138 * setting pointers into the png_info_struct where the data is stored. The
2139 * png_get_<chunk> functions return a non-zero value if the data was available
2140 * in info_ptr, or return zero and do not change any of the parameters if the
2141 * data was not available.
2142 *
2143 * These functions should be used instead of directly accessing png_info
2144 * to avoid problems with future changes in the size and internal layout of
2145 * png_info_struct.
2146 */
2147/* Returns "flag" if chunk data is valid in info_ptr. */
2148PNG_EXPORT(png_uint_32,png_get_valid) PNGARG((png_structp png_ptr,
2149png_infop info_ptr, png_uint_32 flag));
2150
2151/* Returns number of bytes needed to hold a transformed row. */
2152PNG_EXPORT(png_size_t,png_get_rowbytes) PNGARG((png_structp png_ptr,
2153png_infop info_ptr));
2154
2155#ifdef PNG_INFO_IMAGE_SUPPORTED
2156/* Returns row_pointers, which is an array of pointers to scanlines that was
2157 * returned from png_read_png().
2158 */
2159PNG_EXPORT(png_bytepp,png_get_rows) PNGARG((png_structp png_ptr,
2160png_infop info_ptr));
2161/* Set row_pointers, which is an array of pointers to scanlines for use
2162 * by png_write_png().
2163 */
2164PNG_EXPORT(void,png_set_rows) PNGARG((png_structp png_ptr,
2165 png_infop info_ptr, png_bytepp row_pointers));
2166#endif
2167
2168/* Returns number of color channels in image. */
2169PNG_EXPORT(png_byte,png_get_channels) PNGARG((png_structp png_ptr,
2170png_infop info_ptr));
2171
2172#ifdef PNG_EASY_ACCESS_SUPPORTED
2173/* Returns image width in pixels. */
2174PNG_EXPORT(png_uint_32, png_get_image_width) PNGARG((png_structp
2175png_ptr, png_infop info_ptr));
2176
2177/* Returns image height in pixels. */
2178PNG_EXPORT(png_uint_32, png_get_image_height) PNGARG((png_structp
2179png_ptr, png_infop info_ptr));
2180
2181/* Returns image bit_depth. */
2182PNG_EXPORT(png_byte, png_get_bit_depth) PNGARG((png_structp
2183png_ptr, png_infop info_ptr));
2184
2185/* Returns image color_type. */
2186PNG_EXPORT(png_byte, png_get_color_type) PNGARG((png_structp
2187png_ptr, png_infop info_ptr));
2188
2189/* Returns image filter_type. */
2190PNG_EXPORT(png_byte, png_get_filter_type) PNGARG((png_structp
2191png_ptr, png_infop info_ptr));
2192
2193/* Returns image interlace_type. */
2194PNG_EXPORT(png_byte, png_get_interlace_type) PNGARG((png_structp
2195png_ptr, png_infop info_ptr));
2196
2197/* Returns image compression_type. */
2198PNG_EXPORT(png_byte, png_get_compression_type) PNGARG((png_structp
2199png_ptr, png_infop info_ptr));
2200
2201/* Returns image resolution in pixels per meter, from pHYs chunk data. */
2202PNG_EXPORT(png_uint_32, png_get_pixels_per_meter) PNGARG((png_structp
2203png_ptr, png_infop info_ptr));
2204PNG_EXPORT(png_uint_32, png_get_x_pixels_per_meter) PNGARG((png_structp
2205png_ptr, png_infop info_ptr));
2206PNG_EXPORT(png_uint_32, png_get_y_pixels_per_meter) PNGARG((png_structp
2207png_ptr, png_infop info_ptr));
2208
2209/* Returns pixel aspect ratio, computed from pHYs chunk data. */
2210#ifdef PNG_FLOATING_POINT_SUPPORTED
2211PNG_EXPORT(float, png_get_pixel_aspect_ratio) PNGARG((png_structp
2212png_ptr, png_infop info_ptr));
2213#endif
2214
2215/* Returns image x, y offset in pixels or microns, from oFFs chunk data. */
2216PNG_EXPORT(png_int_32, png_get_x_offset_pixels) PNGARG((png_structp
2217png_ptr, png_infop info_ptr));
2218PNG_EXPORT(png_int_32, png_get_y_offset_pixels) PNGARG((png_structp
2219png_ptr, png_infop info_ptr));
2220PNG_EXPORT(png_int_32, png_get_x_offset_microns) PNGARG((png_structp
2221png_ptr, png_infop info_ptr));
2222PNG_EXPORT(png_int_32, png_get_y_offset_microns) PNGARG((png_structp
2223png_ptr, png_infop info_ptr));
2224
2225#endif /* PNG_EASY_ACCESS_SUPPORTED */
2226
2227/* Returns pointer to signature string read from PNG header */
2228PNG_EXPORT(png_bytep,png_get_signature) PNGARG((png_structp png_ptr,
2229png_infop info_ptr));
2230
2231#ifdef PNG_bKGD_SUPPORTED
2232PNG_EXPORT(png_uint_32,png_get_bKGD) PNGARG((png_structp png_ptr,
2233 png_infop info_ptr, png_color_16p *background));
2234#endif
2235
2236#ifdef PNG_bKGD_SUPPORTED
2237PNG_EXPORT(void,png_set_bKGD) PNGARG((png_structp png_ptr,
2238 png_infop info_ptr, png_color_16p background));
2239#endif
2240
2241#ifdef PNG_cHRM_SUPPORTED
2242#ifdef PNG_FLOATING_POINT_SUPPORTED
2243PNG_EXPORT(png_uint_32,png_get_cHRM) PNGARG((png_structp png_ptr,
2244 png_infop info_ptr, double *white_x, double *white_y, double *red_x,
2245 double *red_y, double *green_x, double *green_y, double *blue_x,
2246 double *blue_y));
2247#endif
2248#ifdef PNG_FIXED_POINT_SUPPORTED
2249PNG_EXPORT(png_uint_32,png_get_cHRM_fixed) PNGARG((png_structp png_ptr,
2250 png_infop info_ptr, png_fixed_point *int_white_x, png_fixed_point
2251 *int_white_y, png_fixed_point *int_red_x, png_fixed_point *int_red_y,
2252 png_fixed_point *int_green_x, png_fixed_point *int_green_y, png_fixed_point
2253 *int_blue_x, png_fixed_point *int_blue_y));
2254#endif
2255#endif
2256
2257#ifdef PNG_cHRM_SUPPORTED
2258#ifdef PNG_FLOATING_POINT_SUPPORTED
2259PNG_EXPORT(void,png_set_cHRM) PNGARG((png_structp png_ptr,
2260 png_infop info_ptr, double white_x, double white_y, double red_x,
2261 double red_y, double green_x, double green_y, double blue_x, double blue_y));
2262#endif
2263#ifdef PNG_FIXED_POINT_SUPPORTED
2264PNG_EXPORT(void,png_set_cHRM_fixed) PNGARG((png_structp png_ptr,
2265 png_infop info_ptr, png_fixed_point int_white_x, png_fixed_point int_white_y,
2266 png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
2267 int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
2268 png_fixed_point int_blue_y));
2269#endif
2270#endif
2271
2272#ifdef PNG_gAMA_SUPPORTED
2273#ifdef PNG_FLOATING_POINT_SUPPORTED
2274PNG_EXPORT(png_uint_32,png_get_gAMA) PNGARG((png_structp png_ptr,
2275 png_infop info_ptr, double *file_gamma));
2276#endif
2277PNG_EXPORT(png_uint_32,png_get_gAMA_fixed) PNGARG((png_structp png_ptr,
2278 png_infop info_ptr, png_fixed_point *int_file_gamma));
2279#endif
2280
2281#ifdef PNG_gAMA_SUPPORTED
2282#ifdef PNG_FLOATING_POINT_SUPPORTED
2283PNG_EXPORT(void,png_set_gAMA) PNGARG((png_structp png_ptr,
2284 png_infop info_ptr, double file_gamma));
2285#endif
2286PNG_EXPORT(void,png_set_gAMA_fixed) PNGARG((png_structp png_ptr,
2287 png_infop info_ptr, png_fixed_point int_file_gamma));
2288#endif
2289
2290#ifdef PNG_hIST_SUPPORTED
2291PNG_EXPORT(png_uint_32,png_get_hIST) PNGARG((png_structp png_ptr,
2292 png_infop info_ptr, png_uint_16p *hist));
2293#endif
2294
2295#ifdef PNG_hIST_SUPPORTED
2296PNG_EXPORT(void,png_set_hIST) PNGARG((png_structp png_ptr,
2297 png_infop info_ptr, png_uint_16p hist));
2298#endif
2299
2300PNG_EXPORT(png_uint_32,png_get_IHDR) PNGARG((png_structp png_ptr,
2301 png_infop info_ptr, png_uint_32 *width, png_uint_32 *height,
2302 int *bit_depth, int *color_type, int *interlace_method,
2303 int *compression_method, int *filter_method));
2304
2305PNG_EXPORT(void,png_set_IHDR) PNGARG((png_structp png_ptr,
2306 png_infop info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth,
2307 int color_type, int interlace_method, int compression_method,
2308 int filter_method));
2309
2310#ifdef PNG_oFFs_SUPPORTED
2311PNG_EXPORT(png_uint_32,png_get_oFFs) PNGARG((png_structp png_ptr,
2312 png_infop info_ptr, png_int_32 *offset_x, png_int_32 *offset_y,
2313 int *unit_type));
2314#endif
2315
2316#ifdef PNG_oFFs_SUPPORTED
2317PNG_EXPORT(void,png_set_oFFs) PNGARG((png_structp png_ptr,
2318 png_infop info_ptr, png_int_32 offset_x, png_int_32 offset_y,
2319 int unit_type));
2320#endif
2321
2322#ifdef PNG_pCAL_SUPPORTED
2323PNG_EXPORT(png_uint_32,png_get_pCAL) PNGARG((png_structp png_ptr,
2324 png_infop info_ptr, png_charp *purpose, png_int_32 *X0, png_int_32 *X1,
2325 int *type, int *nparams, png_charp *units, png_charpp *params));
2326#endif
2327
2328#ifdef PNG_pCAL_SUPPORTED
2329PNG_EXPORT(void,png_set_pCAL) PNGARG((png_structp png_ptr,
2330 png_infop info_ptr, png_charp purpose, png_int_32 X0, png_int_32 X1,
2331 int type, int nparams, png_charp units, png_charpp params));
2332#endif
2333
2334#ifdef PNG_pHYs_SUPPORTED
2335PNG_EXPORT(png_uint_32,png_get_pHYs) PNGARG((png_structp png_ptr,
2336 png_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type));
2337#endif
2338
2339#ifdef PNG_pHYs_SUPPORTED
2340PNG_EXPORT(void,png_set_pHYs) PNGARG((png_structp png_ptr,
2341 png_infop info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type));
2342#endif
2343
2344PNG_EXPORT(png_uint_32,png_get_PLTE) PNGARG((png_structp png_ptr,
2345 png_infop info_ptr, png_colorp *palette, int *num_palette));
2346
2347PNG_EXPORT(void,png_set_PLTE) PNGARG((png_structp png_ptr,
2348 png_infop info_ptr, png_colorp palette, int num_palette));
2349
2350#ifdef PNG_sBIT_SUPPORTED
2351PNG_EXPORT(png_uint_32,png_get_sBIT) PNGARG((png_structp png_ptr,
2352 png_infop info_ptr, png_color_8p *sig_bit));
2353#endif
2354
2355#ifdef PNG_sBIT_SUPPORTED
2356PNG_EXPORT(void,png_set_sBIT) PNGARG((png_structp png_ptr,
2357 png_infop info_ptr, png_color_8p sig_bit));
2358#endif
2359
2360#ifdef PNG_sRGB_SUPPORTED
2361PNG_EXPORT(png_uint_32,png_get_sRGB) PNGARG((png_structp png_ptr,
2362 png_infop info_ptr, int *intent));
2363#endif
2364
2365#ifdef PNG_sRGB_SUPPORTED
2366PNG_EXPORT(void,png_set_sRGB) PNGARG((png_structp png_ptr,
2367 png_infop info_ptr, int intent));
2368PNG_EXPORT(void,png_set_sRGB_gAMA_and_cHRM) PNGARG((png_structp png_ptr,
2369 png_infop info_ptr, int intent));
2370#endif
2371
2372#ifdef PNG_iCCP_SUPPORTED
2373PNG_EXPORT(png_uint_32,png_get_iCCP) PNGARG((png_structp png_ptr,
2374 png_infop info_ptr, png_charpp name, int *compression_type,
2375 png_charpp profile, png_uint_32 *proflen));
2376 /* Note to maintainer: profile should be png_bytepp */
2377#endif
2378
2379#ifdef PNG_iCCP_SUPPORTED
2380PNG_EXPORT(void,png_set_iCCP) PNGARG((png_structp png_ptr,
2381 png_infop info_ptr, png_charp name, int compression_type,
2382 png_charp profile, png_uint_32 proflen));
2383 /* Note to maintainer: profile should be png_bytep */
2384#endif
2385
2386#ifdef PNG_sPLT_SUPPORTED
2387PNG_EXPORT(png_uint_32,png_get_sPLT) PNGARG((png_structp png_ptr,
2388 png_infop info_ptr, png_sPLT_tpp entries));
2389#endif
2390
2391#ifdef PNG_sPLT_SUPPORTED
2392PNG_EXPORT(void,png_set_sPLT) PNGARG((png_structp png_ptr,
2393 png_infop info_ptr, png_sPLT_tp entries, int nentries));
2394#endif
2395
2396#ifdef PNG_TEXT_SUPPORTED
2397/* png_get_text also returns the number of text chunks in *num_text */
2398PNG_EXPORT(png_uint_32,png_get_text) PNGARG((png_structp png_ptr,
2399 png_infop info_ptr, png_textp *text_ptr, int *num_text));
2400#endif
2401
2402/* Note while png_set_text() will accept a structure whose text,
2403 * language, and translated keywords are NULL pointers, the structure
2404 * returned by png_get_text will always contain regular
2405 * zero-terminated C strings. They might be empty strings but
2406 * they will never be NULL pointers.
2407 */
2408
2409#ifdef PNG_TEXT_SUPPORTED
2410PNG_EXPORT(void,png_set_text) PNGARG((png_structp png_ptr,
2411 png_infop info_ptr, png_textp text_ptr, int num_text));
2412#endif
2413
2414#ifdef PNG_tIME_SUPPORTED
2415PNG_EXPORT(png_uint_32,png_get_tIME) PNGARG((png_structp png_ptr,
2416 png_infop info_ptr, png_timep *mod_time));
2417#endif
2418
2419#ifdef PNG_tIME_SUPPORTED
2420PNG_EXPORT(void,png_set_tIME) PNGARG((png_structp png_ptr,
2421 png_infop info_ptr, png_timep mod_time));
2422#endif
2423
2424#ifdef PNG_tRNS_SUPPORTED
2425PNG_EXPORT(png_uint_32,png_get_tRNS) PNGARG((png_structp png_ptr,
2426 png_infop info_ptr, png_bytep *trans_alpha, int *num_trans,
2427 png_color_16p *trans_color));
2428#endif
2429
2430#ifdef PNG_tRNS_SUPPORTED
2431PNG_EXPORT(void,png_set_tRNS) PNGARG((png_structp png_ptr,
2432 png_infop info_ptr, png_bytep trans_alpha, int num_trans,
2433 png_color_16p trans_color));
2434#endif
2435
2436#ifdef PNG_tRNS_SUPPORTED
2437#endif
2438
2439#ifdef PNG_sCAL_SUPPORTED
2440#ifdef PNG_FLOATING_POINT_SUPPORTED
2441PNG_EXPORT(png_uint_32,png_get_sCAL) PNGARG((png_structp png_ptr,
2442 png_infop info_ptr, int *unit, double *width, double *height));
2443#else
2444#ifdef PNG_FIXED_POINT_SUPPORTED
2445PNG_EXPORT(png_uint_32,png_get_sCAL_s) PNGARG((png_structp png_ptr,
2446 png_infop info_ptr, int *unit, png_charpp swidth, png_charpp sheight));
2447#endif
2448#endif
2449#endif /* PNG_sCAL_SUPPORTED */
2450
2451#ifdef PNG_sCAL_SUPPORTED
2452#ifdef PNG_FLOATING_POINT_SUPPORTED
2453PNG_EXPORT(void,png_set_sCAL) PNGARG((png_structp png_ptr,
2454 png_infop info_ptr, int unit, double width, double height));
2455#else
2456#ifdef PNG_FIXED_POINT_SUPPORTED
2457PNG_EXPORT(void,png_set_sCAL_s) PNGARG((png_structp png_ptr,
2458 png_infop info_ptr, int unit, png_charp swidth, png_charp sheight));
2459#endif
2460#endif
2461#endif /* PNG_sCAL_SUPPORTED || PNG_WRITE_sCAL_SUPPORTED */
2462
2463#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
2464/* Provide a list of chunks and how they are to be handled, if the built-in
2465 handling or default unknown chunk handling is not desired. Any chunks not
2466 listed will be handled in the default manner. The IHDR and IEND chunks
2467 must not be listed.
2468 keep = 0: follow default behaviour
2469 = 1: do not keep
2470 = 2: keep only if safe-to-copy
2471 = 3: keep even if unsafe-to-copy
2472*/
2473PNG_EXPORT(void, png_set_keep_unknown_chunks) PNGARG((png_structp
2474 png_ptr, int keep, png_bytep chunk_list, int num_chunks));
2475PNG_EXPORT(int,png_handle_as_unknown) PNGARG((png_structp png_ptr, png_bytep
2476 chunk_name));
2477#endif
2478#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
2479PNG_EXPORT(void, png_set_unknown_chunks) PNGARG((png_structp png_ptr,
2480 png_infop info_ptr, png_unknown_chunkp unknowns, int num_unknowns));
2481PNG_EXPORT(void, png_set_unknown_chunk_location)
2482 PNGARG((png_structp png_ptr, png_infop info_ptr, int chunk, int location));
2483PNG_EXPORT(png_uint_32,png_get_unknown_chunks) PNGARG((png_structp
2484 png_ptr, png_infop info_ptr, png_unknown_chunkpp entries));
2485#endif
2486
2487/* Png_free_data() will turn off the "valid" flag for anything it frees.
2488 * If you need to turn it off for a chunk that your application has freed,
2489 * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK);
2490 */
2491PNG_EXPORT(void, png_set_invalid) PNGARG((png_structp png_ptr,
2492 png_infop info_ptr, int mask));
2493
2494#ifdef PNG_INFO_IMAGE_SUPPORTED
2495/* The "params" pointer is currently not used and is for future expansion. */
2496PNG_EXPORT(void, png_read_png) PNGARG((png_structp png_ptr,
2497 png_infop info_ptr,
2498 int transforms,
2499 png_voidp params));
2500PNG_EXPORT(void, png_write_png) PNGARG((png_structp png_ptr,
2501 png_infop info_ptr,
2502 int transforms,
2503 png_voidp params));
2504#endif
2505
2506PNG_EXPORT(png_charp,png_get_copyright) PNGARG((png_structp png_ptr));
2507PNG_EXPORT(png_charp,png_get_header_ver) PNGARG((png_structp png_ptr));
2508PNG_EXPORT(png_charp,png_get_header_version) PNGARG((png_structp
2509 png_ptr));
2510PNG_EXPORT(png_charp,png_get_libpng_ver) PNGARG((png_structp png_ptr));
2511
2512#ifdef PNG_MNG_FEATURES_SUPPORTED
2513PNG_EXPORT(png_uint_32,png_permit_mng_features) PNGARG((png_structp
2514 png_ptr, png_uint_32 mng_features_permitted));
2515#endif
2516
2517/* For use in png_set_keep_unknown, added to version 1.2.6 */
2518#define PNG_HANDLE_CHUNK_AS_DEFAULT 0
2519#define PNG_HANDLE_CHUNK_NEVER 1
2520#define PNG_HANDLE_CHUNK_IF_SAFE 2
2521#define PNG_HANDLE_CHUNK_ALWAYS 3
2522
2523/* Strip the prepended error numbers ("#nnn ") from error and warning
2524 * messages before passing them to the error or warning handler.
2525 */
2526#ifdef PNG_ERROR_NUMBERS_SUPPORTED
2527PNG_EXPORT(void,png_set_strip_error_numbers) PNGARG((png_structp
2528 png_ptr, png_uint_32 strip_mode));
2529#endif
2530
2531/* Added in libpng-1.2.6 */
2532#ifdef PNG_SET_USER_LIMITS_SUPPORTED
2533PNG_EXPORT(void,png_set_user_limits) PNGARG((png_structp
2534 png_ptr, png_uint_32 user_width_max, png_uint_32 user_height_max));
2535PNG_EXPORT(png_uint_32,png_get_user_width_max) PNGARG((png_structp
2536 png_ptr));
2537PNG_EXPORT(png_uint_32,png_get_user_height_max) PNGARG((png_structp
2538 png_ptr));
2539/* Added in libpng-1.4.0 */
2540PNG_EXPORT(void,png_set_chunk_cache_max) PNGARG((png_structp
2541 png_ptr, png_uint_32 user_chunk_cache_max));
2542PNG_EXPORT(png_uint_32,png_get_chunk_cache_max)
2543 PNGARG((png_structp png_ptr));
2544/* Added in libpng-1.4.1 */
2545PNG_EXPORT(void,png_set_chunk_malloc_max) PNGARG((png_structp
2546 png_ptr, png_alloc_size_t user_chunk_cache_max));
2547PNG_EXPORT(png_alloc_size_t,png_get_chunk_malloc_max)
2548 PNGARG((png_structp png_ptr));
2549#endif
2550
2551#if defined(PNG_INCH_CONVERSIONS) && defined(PNG_FLOATING_POINT_SUPPORTED)
2552PNG_EXPORT(png_uint_32,png_get_pixels_per_inch) PNGARG((png_structp png_ptr,
2553png_infop info_ptr));
2554
2555PNG_EXPORT(png_uint_32,png_get_x_pixels_per_inch) PNGARG((png_structp png_ptr,
2556png_infop info_ptr));
2557
2558PNG_EXPORT(png_uint_32,png_get_y_pixels_per_inch) PNGARG((png_structp png_ptr,
2559png_infop info_ptr));
2560
2561PNG_EXPORT(float,png_get_x_offset_inches) PNGARG((png_structp png_ptr,
2562png_infop info_ptr));
2563
2564PNG_EXPORT(float,png_get_y_offset_inches) PNGARG((png_structp png_ptr,
2565png_infop info_ptr));
2566
2567#ifdef PNG_pHYs_SUPPORTED
2568PNG_EXPORT(png_uint_32,png_get_pHYs_dpi) PNGARG((png_structp png_ptr,
2569png_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type));
2570#endif /* PNG_pHYs_SUPPORTED */
2571#endif /* PNG_INCH_CONVERSIONS && PNG_FLOATING_POINT_SUPPORTED */
2572
2573/* Added in libpng-1.4.0 */
2574#ifdef PNG_IO_STATE_SUPPORTED
2575PNG_EXPORT(png_uint_32,png_get_io_state) PNGARG((png_structp png_ptr));
2576
2577PNG_EXPORT(png_bytep,png_get_io_chunk_name)
2578 PNGARG((png_structp png_ptr));
2579
2580/* The flags returned by png_get_io_state() are the following: */
2581#define PNG_IO_NONE 0x0000 /* no I/O at this moment */
2582#define PNG_IO_READING 0x0001 /* currently reading */
2583#define PNG_IO_WRITING 0x0002 /* currently writing */
2584#define PNG_IO_SIGNATURE 0x0010 /* currently at the file signature */
2585#define PNG_IO_CHUNK_HDR 0x0020 /* currently at the chunk header */
2586#define PNG_IO_CHUNK_DATA 0x0040 /* currently at the chunk data */
2587#define PNG_IO_CHUNK_CRC 0x0080 /* currently at the chunk crc */
2588#define PNG_IO_MASK_OP 0x000f /* current operation: reading/writing */
2589#define PNG_IO_MASK_LOC 0x00f0 /* current location: sig/hdr/data/crc */
2590#endif /* ?PNG_IO_STATE_SUPPORTED */
2591
2592/* Maintainer: Put new public prototypes here ^, in libpng.3, and project
2593 * defs
2594 */
2595
2596#ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
2597/* With these routines we avoid an integer divide, which will be slower on
2598 * most machines. However, it does take more operations than the corresponding
2599 * divide method, so it may be slower on a few RISC systems. There are two
2600 * shifts (by 8 or 16 bits) and an addition, versus a single integer divide.
2601 *
2602 * Note that the rounding factors are NOT supposed to be the same! 128 and
2603 * 32768 are correct for the NODIV code; 127 and 32767 are correct for the
2604 * standard method.
2605 *
2606 * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
2607 */
2608
2609 /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */
2610
2611# define png_composite(composite, fg, alpha, bg) \
2612 { png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \
2613 * (png_uint_16)(alpha) \
2614 + (png_uint_16)(bg)*(png_uint_16)(255 \
2615 - (png_uint_16)(alpha)) + (png_uint_16)128); \
2616 (composite) = (png_byte)((temp + (temp >> 8)) >> 8); }
2617
2618# define png_composite_16(composite, fg, alpha, bg) \
2619 { png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) \
2620 * (png_uint_32)(alpha) \
2621 + (png_uint_32)(bg)*(png_uint_32)(65535L \
2622 - (png_uint_32)(alpha)) + (png_uint_32)32768L); \
2623 (composite) = (png_uint_16)((temp + (temp >> 16)) >> 16); }
2624
2625#else /* Standard method using integer division */
2626
2627# define png_composite(composite, fg, alpha, bg) \
2628 (composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) + \
2629 (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \
2630 (png_uint_16)127) / 255)
2631
2632# define png_composite_16(composite, fg, alpha, bg) \
2633 (composite) = (png_uint_16)(((png_uint_32)(fg) * (png_uint_32)(alpha) + \
2634 (png_uint_32)(bg)*(png_uint_32)(65535L - (png_uint_32)(alpha)) + \
2635 (png_uint_32)32767) / (png_uint_32)65535L)
2636#endif /* PNG_READ_COMPOSITE_NODIV_SUPPORTED */
2637
2638#ifdef PNG_USE_READ_MACROS
2639/* Inline macros to do direct reads of bytes from the input buffer.
2640 * The png_get_int_32() routine assumes we are using two's complement
2641 * format for negative values, which is almost certainly true.
2642 */
2643# define png_get_uint_32(buf) \
2644 (((png_uint_32)(*(buf)) << 24) + \
2645 ((png_uint_32)(*((buf) + 1)) << 16) + \
2646 ((png_uint_32)(*((buf) + 2)) << 8) + \
2647 ((png_uint_32)(*((buf) + 3))))
2648# define png_get_uint_16(buf) \
2649 (((png_uint_32)(*(buf)) << 8) + \
2650 ((png_uint_32)(*((buf) + 1))))
2651# define png_get_int_32(buf) \
2652 ((png_int_32)((*(buf) & 0x80) \
2653 ? -((png_int_32)((png_get_uint_32(buf) ^ 0xffffffff)+1)) \
2654 : (png_int_32)png_get_uint_32(buf)))
2655#else
2656PNG_EXPORT(png_uint_32,png_get_uint_32) PNGARG((png_bytep buf));
2657PNG_EXPORT(png_uint_16,png_get_uint_16) PNGARG((png_bytep buf));
2658#ifdef PNG_GET_INT_32_SUPPORTED
2659PNG_EXPORT(png_int_32,png_get_int_32) PNGARG((png_bytep buf));
2660#endif
2661#endif
2662PNG_EXPORT(png_uint_32,png_get_uint_31)
2663 PNGARG((png_structp png_ptr, png_bytep buf));
2664/* No png_get_int_16 -- may be added if there's a real need for it. */
2665
2666/* Place a 32-bit number into a buffer in PNG byte order (big-endian). */
2667PNG_EXPORT(void,png_save_uint_32)
2668 PNGARG((png_bytep buf, png_uint_32 i));
2669PNG_EXPORT(void,png_save_int_32)
2670 PNGARG((png_bytep buf, png_int_32 i));
2671
2672/* Place a 16-bit number into a buffer in PNG byte order.
2673 * The parameter is declared unsigned int, not png_uint_16,
2674 * just to avoid potential problems on pre-ANSI C compilers.
2675 */
2676PNG_EXPORT(void,png_save_uint_16)
2677 PNGARG((png_bytep buf, unsigned int i));
2678/* No png_save_int_16 -- may be added if there's a real need for it. */
2679
2680/* ************************************************************************* */
2681
2682/* Various modes of operation. Note that after an init, mode is set to
2683 * zero automatically when the structure is created.
2684 */
2685#define PNG_HAVE_IHDR 0x01
2686#define PNG_HAVE_PLTE 0x02
2687#define PNG_HAVE_IDAT 0x04
2688#define PNG_AFTER_IDAT 0x08 /* Have complete zlib datastream */
2689#define PNG_HAVE_IEND 0x10
2690#define PNG_HAVE_gAMA 0x20
2691#define PNG_HAVE_cHRM 0x40
2692
2693#ifdef __cplusplus
2694}
2695#endif
2696
2697#endif /* PNG_VERSION_INFO_ONLY */
2698/* Do not put anything past this line */
2699#endif /* PNG_H */
wxWidgets (Impactor)