source: trunk/src/3rdparty/libpng/png.h@ 1036

Last change on this file since 1036 was 846, checked in by Dmitry A. Kuminov, 14 years ago

trunk: Merged in qt 4.7.2 sources from branches/vendor/nokia/qt.

File size: 109.5 KB
Line 
1
2/* png.h - header file for PNG reference library
3 *
4 * libpng version 1.4.0 - January 3, 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 1.4.0 - January 3, 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 *
138 * Henceforth the source version will match the shared-library major
139 * and minor numbers; the shared-library major version number will be
140 * used for changes in backward compatibility, as it is intended. The
141 * PNG_LIBPNG_VER macro, which is not used within libpng but is available
142 * for applications, is an unsigned integer of the form xyyzz corresponding
143 * to the source version x.y.z (leading zeros in y and z). Beta versions
144 * were given the previous public release number plus a letter, until
145 * version 1.0.6j; from then on they were given the upcoming public
146 * release number plus "betaNN" or "rcN".
147 *
148 * Binary incompatibility exists only when applications make direct access
149 * to the info_ptr or png_ptr members through png.h, and the compiled
150 * application is loaded with a different version of the library.
151 *
152 * DLLNUM will change each time there are forward or backward changes
153 * in binary compatibility (e.g., when a new feature is added).
154 *
155 * See libpng.txt or libpng.3 for more information. The PNG specification
156 * is available as a W3C Recommendation and as an ISO Specification,
157 * <http://www.w3.org/TR/2003/REC-PNG-20031110/
158 */
159
160/*
161 * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
162 *
163 * If you modify libpng you may insert additional notices immediately following
164 * this sentence.
165 *
166 * This code is released under the libpng license.
167 *
168 * libpng versions 1.2.6, August 15, 2004, through 1.4.0, January 3, 2010, are
169 * Copyright (c) 2004, 2006-2010 Glenn Randers-Pehrson, and are
170 * distributed according to the same disclaimer and license as libpng-1.2.5
171 * with the following individual added to the list of Contributing Authors:
172 *
173 * Cosmin Truta
174 *
175 * libpng versions 1.0.7, July 1, 2000, through 1.2.5, October 3, 2002, are
176 * Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are
177 * distributed according to the same disclaimer and license as libpng-1.0.6
178 * with the following individuals added to the list of Contributing Authors:
179 *
180 * Simon-Pierre Cadieux
181 * Eric S. Raymond
182 * Gilles Vollant
183 *
184 * and with the following additions to the disclaimer:
185 *
186 * There is no warranty against interference with your enjoyment of the
187 * library or against infringement. There is no warranty that our
188 * efforts or the library will fulfill any of your particular purposes
189 * or needs. This library is provided with all faults, and the entire
190 * risk of satisfactory quality, performance, accuracy, and effort is with
191 * the user.
192 *
193 * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
194 * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson, and are
195 * distributed according to the same disclaimer and license as libpng-0.96,
196 * with the following individuals added to the list of Contributing Authors:
197 *
198 * Tom Lane
199 * Glenn Randers-Pehrson
200 * Willem van Schaik
201 *
202 * libpng versions 0.89, June 1996, through 0.96, May 1997, are
203 * Copyright (c) 1996, 1997 Andreas Dilger
204 * Distributed according to the same disclaimer and license as libpng-0.88,
205 * with the following individuals added to the list of Contributing Authors:
206 *
207 * John Bowler
208 * Kevin Bracey
209 * Sam Bushell
210 * Magnus Holmgren
211 * Greg Roelofs
212 * Tom Tanner
213 *
214 * libpng versions 0.5, May 1995, through 0.88, January 1996, are
215 * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
216 *
217 * For the purposes of this copyright and license, "Contributing Authors"
218 * is defined as the following set of individuals:
219 *
220 * Andreas Dilger
221 * Dave Martindale
222 * Guy Eric Schalnat
223 * Paul Schmidt
224 * Tim Wegner
225 *
226 * The PNG Reference Library is supplied "AS IS". The Contributing Authors
227 * and Group 42, Inc. disclaim all warranties, expressed or implied,
228 * including, without limitation, the warranties of merchantability and of
229 * fitness for any purpose. The Contributing Authors and Group 42, Inc.
230 * assume no liability for direct, indirect, incidental, special, exemplary,
231 * or consequential damages, which may result from the use of the PNG
232 * Reference Library, even if advised of the possibility of such damage.
233 *
234 * Permission is hereby granted to use, copy, modify, and distribute this
235 * source code, or portions hereof, for any purpose, without fee, subject
236 * to the following restrictions:
237 *
238 * 1. The origin of this source code must not be misrepresented.
239 *
240 * 2. Altered versions must be plainly marked as such and
241 * must not be misrepresented as being the original source.
242 *
243 * 3. This Copyright notice may not be removed or altered from
244 * any source or altered source distribution.
245 *
246 * The Contributing Authors and Group 42, Inc. specifically permit, without
247 * fee, and encourage the use of this source code as a component to
248 * supporting the PNG file format in commercial products. If you use this
249 * source code in a product, acknowledgment is not required but would be
250 * appreciated.
251 */
252
253/*
254 * A "png_get_copyright" function is available, for convenient use in "about"
255 * boxes and the like:
256 *
257 * printf("%s",png_get_copyright(NULL));
258 *
259 * Also, the PNG logo (in PNG format, of course) is supplied in the
260 * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
261 */
262
263/*
264 * Libpng is OSI Certified Open Source Software. OSI Certified is a
265 * certification mark of the Open Source Initiative.
266 */
267
268/*
269 * The contributing authors would like to thank all those who helped
270 * with testing, bug fixes, and patience. This wouldn't have been
271 * possible without all of you.
272 *
273 * Thanks to Frank J. T. Wojcik for helping with the documentation.
274 */
275
276/*
277 * Y2K compliance in libpng:
278 * =========================
279 *
280 * January 3, 2010
281 *
282 * Since the PNG Development group is an ad-hoc body, we can't make
283 * an official declaration.
284 *
285 * This is your unofficial assurance that libpng from version 0.71 and
286 * upward through 1.4.0 are Y2K compliant. It is my belief that earlier
287 * versions were also Y2K compliant.
288 *
289 * Libpng only has three year fields. One is a 2-byte unsigned integer
290 * that will hold years up to 65535. The other two hold the date in text
291 * format, and will hold years up to 9999.
292 *
293 * The integer is
294 * "png_uint_16 year" in png_time_struct.
295 *
296 * The strings are
297 * "png_charp time_buffer" in png_struct and
298 * "near_time_buffer", which is a local character string in png.c.
299 *
300 * There are seven time-related functions:
301 * png.c: png_convert_to_rfc_1123() in png.c
302 * (formerly png_convert_to_rfc_1152() in error)
303 * png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
304 * png_convert_from_time_t() in pngwrite.c
305 * png_get_tIME() in pngget.c
306 * png_handle_tIME() in pngrutil.c, called in pngread.c
307 * png_set_tIME() in pngset.c
308 * png_write_tIME() in pngwutil.c, called in pngwrite.c
309 *
310 * All handle dates properly in a Y2K environment. The
311 * png_convert_from_time_t() function calls gmtime() to convert from system
312 * clock time, which returns (year - 1900), which we properly convert to
313 * the full 4-digit year. There is a possibility that applications using
314 * libpng are not passing 4-digit years into the png_convert_to_rfc_1123()
315 * function, or that they are incorrectly passing only a 2-digit year
316 * instead of "year - 1900" into the png_convert_from_struct_tm() function,
317 * but this is not under our control. The libpng documentation has always
318 * stated that it works with 4-digit years, and the APIs have been
319 * documented as such.
320 *
321 * The tIME chunk itself is also Y2K compliant. It uses a 2-byte unsigned
322 * integer to hold the year, and can hold years as large as 65535.
323 *
324 * zlib, upon which libpng depends, is also Y2K compliant. It contains
325 * no date-related code.
326 *
327 * Glenn Randers-Pehrson
328 * libpng maintainer
329 * PNG Development Group
330 */
331
332#ifndef PNG_H
333#define PNG_H
334
335/* This is not the place to learn how to use libpng. The file libpng.txt
336 * describes how to use libpng, and the file example.c summarizes it
337 * with some code on which to build. This file is useful for looking
338 * at the actual function definitions and structure components.
339 */
340
341/* Version information for png.h - this should match the version in png.c */
342#define PNG_LIBPNG_VER_STRING "1.4.0"
343#define PNG_HEADER_VERSION_STRING \
344 " libpng version 1.4.0 - January 3, 2010\n"
345
346#define PNG_LIBPNG_VER_SONUM 14
347#define PNG_LIBPNG_VER_DLLNUM 14
348
349/* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
350#define PNG_LIBPNG_VER_MAJOR 1
351#define PNG_LIBPNG_VER_MINOR 4
352#define PNG_LIBPNG_VER_RELEASE 0
353/* This should match the numeric part of the final component of
354 * PNG_LIBPNG_VER_STRING, omitting any leading zero:
355 */
356
357#define PNG_LIBPNG_VER_BUILD 0
358
359/* Release Status */
360#define PNG_LIBPNG_BUILD_ALPHA 1
361#define PNG_LIBPNG_BUILD_BETA 2
362#define PNG_LIBPNG_BUILD_RC 3
363#define PNG_LIBPNG_BUILD_STABLE 4
364#define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7
365
366/* Release-Specific Flags */
367#define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with
368 PNG_LIBPNG_BUILD_STABLE only */
369#define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with
370 PNG_LIBPNG_BUILD_SPECIAL */
371#define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with
372 PNG_LIBPNG_BUILD_PRIVATE */
373
374#define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_BETA
375
376/* Careful here. At one time, Guy wanted to use 082, but that would be octal.
377 * We must not include leading zeros.
378 * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only
379 * version 1.0.0 was mis-numbered 100 instead of 10000). From
380 * version 1.0.1 it's xxyyzz, where x=major, y=minor, z=release
381 */
382#define PNG_LIBPNG_VER 10400 /* 1.4.0 */
383
384#ifndef PNG_VERSION_INFO_ONLY
385/* Include the compression library's header */
386#include "zlib.h"
387#endif
388
389#ifdef _AIX
390#define jmpbuf __jmpbuf
391#endif
392
393/* Include all user configurable info, including optional assembler routines */
394#include "pngconf.h"
395
396/*
397 * Added at libpng-1.2.8
398 *
399 * Ref MSDN: Private as priority over Special
400 * VS_FF_PRIVATEBUILD File *was not* built using standard release
401 * procedures. If this value is given, the StringFileInfo block must
402 * contain a PrivateBuild string.
403 *
404 * VS_FF_SPECIALBUILD File *was* built by the original company using
405 * standard release procedures but is a variation of the standard
406 * file of the same version number. If this value is given, the
407 * StringFileInfo block must contain a SpecialBuild string.
408 */
409
410#ifdef PNG_USER_PRIVATEBUILD
411# define PNG_LIBPNG_BUILD_TYPE \
412 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE)
413#else
414# ifdef PNG_LIBPNG_SPECIALBUILD
415# define PNG_LIBPNG_BUILD_TYPE \
416 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL)
417# else
418# define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE)
419# endif
420#endif
421
422#ifndef PNG_VERSION_INFO_ONLY
423
424/* Inhibit C++ name-mangling for libpng functions but not for system calls. */
425#ifdef __cplusplus
426extern "C" {
427#endif /* __cplusplus */
428
429/* This file is arranged in several sections. The first section contains
430 * structure and type definitions. The second section contains the external
431 * library functions, while the third has the internal library functions,
432 * which applications aren't expected to use directly.
433 */
434
435/* Variables declared in png.c - only it needs to define PNG_NO_EXTERN */
436#if !defined(PNG_NO_EXTERN) || defined(PNG_ALWAYS_EXTERN)
437/* Version information for C files, stored in png.c. This had better match
438 * the version above.
439 */
440#define png_libpng_ver png_get_header_ver(NULL)
441
442#endif /* PNG_NO_EXTERN */
443
444/* Three color definitions. The order of the red, green, and blue, (and the
445 * exact size) is not important, although the size of the fields need to
446 * be png_byte or png_uint_16 (as defined below).
447 */
448typedef struct png_color_struct
449{
450 png_byte red;
451 png_byte green;
452 png_byte blue;
453} png_color;
454typedef png_color FAR * png_colorp;
455typedef png_color FAR * FAR * png_colorpp;
456
457typedef struct png_color_16_struct
458{
459 png_byte index; /* used for palette files */
460 png_uint_16 red; /* for use in red green blue files */
461 png_uint_16 green;
462 png_uint_16 blue;
463 png_uint_16 gray; /* for use in grayscale files */
464} png_color_16;
465typedef png_color_16 FAR * png_color_16p;
466typedef png_color_16 FAR * FAR * png_color_16pp;
467
468typedef struct png_color_8_struct
469{
470 png_byte red; /* for use in red green blue files */
471 png_byte green;
472 png_byte blue;
473 png_byte gray; /* for use in grayscale files */
474 png_byte alpha; /* for alpha channel files */
475} png_color_8;
476typedef png_color_8 FAR * png_color_8p;
477typedef png_color_8 FAR * FAR * png_color_8pp;
478
479/*
480 * The following two structures are used for the in-core representation
481 * of sPLT chunks.
482 */
483typedef struct png_sPLT_entry_struct
484{
485 png_uint_16 red;
486 png_uint_16 green;
487 png_uint_16 blue;
488 png_uint_16 alpha;
489 png_uint_16 frequency;
490} png_sPLT_entry;
491typedef png_sPLT_entry FAR * png_sPLT_entryp;
492typedef png_sPLT_entry FAR * FAR * png_sPLT_entrypp;
493
494/* When the depth of the sPLT palette is 8 bits, the color and alpha samples
495 * occupy the LSB of their respective members, and the MSB of each member
496 * is zero-filled. The frequency member always occupies the full 16 bits.
497 */
498
499typedef struct png_sPLT_struct
500{
501 png_charp name; /* palette name */
502 png_byte depth; /* depth of palette samples */
503 png_sPLT_entryp entries; /* palette entries */
504 png_int_32 nentries; /* number of palette entries */
505} png_sPLT_t;
506typedef png_sPLT_t FAR * png_sPLT_tp;
507typedef png_sPLT_t FAR * FAR * png_sPLT_tpp;
508
509#ifdef PNG_TEXT_SUPPORTED
510/* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,
511 * and whether that contents is compressed or not. The "key" field
512 * points to a regular zero-terminated C string. The "text", "lang", and
513 * "lang_key" fields can be regular C strings, empty strings, or NULL pointers.
514 * However, the * structure returned by png_get_text() will always contain
515 * regular zero-terminated C strings (possibly empty), never NULL pointers,
516 * so they can be safely used in printf() and other string-handling functions.
517 */
518typedef struct png_text_struct
519{
520 int compression; /* compression value:
521 -1: tEXt, none
522 0: zTXt, deflate
523 1: iTXt, none
524 2: iTXt, deflate */
525 png_charp key; /* keyword, 1-79 character description of "text" */
526 png_charp text; /* comment, may be an empty string (ie "")
527 or a NULL pointer */
528 png_size_t text_length; /* length of the text string */
529#ifdef PNG_iTXt_SUPPORTED
530 png_size_t itxt_length; /* length of the itxt string */
531 png_charp lang; /* language code, 0-79 characters
532 or a NULL pointer */
533 png_charp lang_key; /* keyword translated UTF-8 string, 0 or more
534 chars or a NULL pointer */
535#endif
536} png_text;
537typedef png_text FAR * png_textp;
538typedef png_text FAR * FAR * png_textpp;
539#endif
540
541/* Supported compression types for text in PNG files (tEXt, and zTXt).
542 * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */
543#define PNG_TEXT_COMPRESSION_NONE_WR -3
544#define PNG_TEXT_COMPRESSION_zTXt_WR -2
545#define PNG_TEXT_COMPRESSION_NONE -1
546#define PNG_TEXT_COMPRESSION_zTXt 0
547#define PNG_ITXT_COMPRESSION_NONE 1
548#define PNG_ITXT_COMPRESSION_zTXt 2
549#define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */
550
551/* png_time is a way to hold the time in an machine independent way.
552 * Two conversions are provided, both from time_t and struct tm. There
553 * is no portable way to convert to either of these structures, as far
554 * as I know. If you know of a portable way, send it to me. As a side
555 * note - PNG has always been Year 2000 compliant!
556 */
557typedef struct png_time_struct
558{
559 png_uint_16 year; /* full year, as in, 1995 */
560 png_byte month; /* month of year, 1 - 12 */
561 png_byte day; /* day of month, 1 - 31 */
562 png_byte hour; /* hour of day, 0 - 23 */
563 png_byte minute; /* minute of hour, 0 - 59 */
564 png_byte second; /* second of minute, 0 - 60 (for leap seconds) */
565} png_time;
566typedef png_time FAR * png_timep;
567typedef png_time FAR * FAR * png_timepp;
568
569#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) || \
570 defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
571/* png_unknown_chunk is a structure to hold queued chunks for which there is
572 * no specific support. The idea is that we can use this to queue
573 * up private chunks for output even though the library doesn't actually
574 * know about their semantics.
575 */
576typedef struct png_unknown_chunk_t
577{
578 png_byte name[5];
579 png_byte *data;
580 png_size_t size;
581
582 /* libpng-using applications should NOT directly modify this byte. */
583 png_byte location; /* mode of operation at read time */
584}
585png_unknown_chunk;
586typedef png_unknown_chunk FAR * png_unknown_chunkp;
587typedef png_unknown_chunk FAR * FAR * png_unknown_chunkpp;
588#endif
589
590/* png_info is a structure that holds the information in a PNG file so
591 * that the application can find out the characteristics of the image.
592 * If you are reading the file, this structure will tell you what is
593 * in the PNG file. If you are writing the file, fill in the information
594 * you want to put into the PNG file, then call png_write_info().
595 * The names chosen should be very close to the PNG specification, so
596 * consult that document for information about the meaning of each field.
597 *
598 * With libpng < 0.95, it was only possible to directly set and read the
599 * the values in the png_info_struct, which meant that the contents and
600 * order of the values had to remain fixed. With libpng 0.95 and later,
601 * however, there are now functions that abstract the contents of
602 * png_info_struct from the application, so this makes it easier to use
603 * libpng with dynamic libraries, and even makes it possible to use
604 * libraries that don't have all of the libpng ancillary chunk-handing
605 * functionality.
606 *
607 * In any case, the order of the parameters in png_info_struct should NOT
608 * be changed for as long as possible to keep compatibility with applications
609 * that use the old direct-access method with png_info_struct.
610 *
611 * The following members may have allocated storage attached that should be
612 * cleaned up before the structure is discarded: palette, trans, text,
613 * pcal_purpose, pcal_units, pcal_params, hist, iccp_name, iccp_profile,
614 * splt_palettes, scal_unit, row_pointers, and unknowns. By default, these
615 * are automatically freed when the info structure is deallocated, if they were
616 * allocated internally by libpng. This behavior can be changed by means
617 * of the png_data_freer() function.
618 *
619 * More allocation details: all the chunk-reading functions that
620 * change these members go through the corresponding png_set_*
621 * functions. A function to clear these members is available: see
622 * png_free_data(). The png_set_* functions do not depend on being
623 * able to point info structure members to any of the storage they are
624 * passed (they make their own copies), EXCEPT that the png_set_text
625 * functions use the same storage passed to them in the text_ptr or
626 * itxt_ptr structure argument, and the png_set_rows and png_set_unknowns
627 * functions do not make their own copies.
628 */
629typedef struct png_info_struct
630{
631 /* the following are necessary for every PNG file */
632 png_uint_32 width PNG_DEPSTRUCT; /* width of image in pixels (from IHDR) */
633 png_uint_32 height PNG_DEPSTRUCT; /* height of image in pixels (from IHDR) */
634 png_uint_32 valid PNG_DEPSTRUCT; /* valid chunk data (see PNG_INFO_ below) */
635 png_size_t rowbytes PNG_DEPSTRUCT; /* bytes needed to hold an untransformed row */
636 png_colorp palette PNG_DEPSTRUCT; /* array of color values (valid & PNG_INFO_PLTE) */
637 png_uint_16 num_palette PNG_DEPSTRUCT; /* number of color entries in "palette" (PLTE) */
638 png_uint_16 num_trans PNG_DEPSTRUCT; /* number of transparent palette color (tRNS) */
639 png_byte bit_depth PNG_DEPSTRUCT; /* 1, 2, 4, 8, or 16 bits/channel (from IHDR) */
640 png_byte color_type PNG_DEPSTRUCT; /* see PNG_COLOR_TYPE_ below (from IHDR) */
641 /* The following three should have been named *_method not *_type */
642 png_byte compression_type PNG_DEPSTRUCT; /* must be PNG_COMPRESSION_TYPE_BASE (IHDR) */
643 png_byte filter_type PNG_DEPSTRUCT; /* must be PNG_FILTER_TYPE_BASE (from IHDR) */
644 png_byte interlace_type PNG_DEPSTRUCT; /* One of PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
645
646 /* The following is informational only on read, and not used on writes. */
647 png_byte channels PNG_DEPSTRUCT; /* number of data channels per pixel (1, 2, 3, 4) */
648 png_byte pixel_depth PNG_DEPSTRUCT; /* number of bits per pixel */
649 png_byte spare_byte PNG_DEPSTRUCT; /* to align the data, and for future use */
650 png_byte signature[8] PNG_DEPSTRUCT; /* magic bytes read by libpng from start of file */
651
652 /* The rest of the data is optional. If you are reading, check the
653 * valid field to see if the information in these are valid. If you
654 * are writing, set the valid field to those chunks you want written,
655 * and initialize the appropriate fields below.
656 */
657
658#if defined(PNG_gAMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
659 /* The gAMA chunk describes the gamma characteristics of the system
660 * on which the image was created, normally in the range [1.0, 2.5].
661 * Data is valid if (valid & PNG_INFO_gAMA) is non-zero.
662 */
663 float gamma PNG_DEPSTRUCT; /* gamma value of image, if (valid & PNG_INFO_gAMA) */
664#endif
665
666#ifdef PNG_sRGB_SUPPORTED
667 /* GR-P, 0.96a */
668 /* Data valid if (valid & PNG_INFO_sRGB) non-zero. */
669 png_byte srgb_intent PNG_DEPSTRUCT; /* sRGB rendering intent [0, 1, 2, or 3] */
670#endif
671
672#ifdef PNG_TEXT_SUPPORTED
673 /* The tEXt, and zTXt chunks contain human-readable textual data in
674 * uncompressed, compressed, and optionally compressed forms, respectively.
675 * The data in "text" is an array of pointers to uncompressed,
676 * null-terminated C strings. Each chunk has a keyword that describes the
677 * textual data contained in that chunk. Keywords are not required to be
678 * unique, and the text string may be empty. Any number of text chunks may
679 * be in an image.
680 */
681 int num_text PNG_DEPSTRUCT; /* number of comments read/to write */
682 int max_text PNG_DEPSTRUCT; /* current size of text array */
683 png_textp text PNG_DEPSTRUCT; /* array of comments read/to write */
684#endif /* PNG_TEXT_SUPPORTED */
685
686#ifdef PNG_tIME_SUPPORTED
687 /* The tIME chunk holds the last time the displayed image data was
688 * modified. See the png_time struct for the contents of this struct.
689 */
690 png_time mod_time PNG_DEPSTRUCT;
691#endif
692
693#ifdef PNG_sBIT_SUPPORTED
694 /* The sBIT chunk specifies the number of significant high-order bits
695 * in the pixel data. Values are in the range [1, bit_depth], and are
696 * only specified for the channels in the pixel data. The contents of
697 * the low-order bits is not specified. Data is valid if
698 * (valid & PNG_INFO_sBIT) is non-zero.
699 */
700 png_color_8 sig_bit PNG_DEPSTRUCT; /* significant bits in color channels */
701#endif
702
703#if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_EXPAND_SUPPORTED) || \
704defined(PNG_READ_BACKGROUND_SUPPORTED)
705 /* The tRNS chunk supplies transparency data for paletted images and
706 * other image types that don't need a full alpha channel. There are
707 * "num_trans" transparency values for a paletted image, stored in the
708 * same order as the palette colors, starting from index 0. Values
709 * for the data are in the range [0, 255], ranging from fully transparent
710 * to fully opaque, respectively. For non-paletted images, there is a
711 * single color specified that should be treated as fully transparent.
712 * Data is valid if (valid & PNG_INFO_tRNS) is non-zero.
713 */
714 png_bytep trans_alpha PNG_DEPSTRUCT; /* alpha values for paletted image */
715 png_color_16 trans_color PNG_DEPSTRUCT; /* transparent color for non-palette image */
716#endif
717
718#if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
719 /* The bKGD chunk gives the suggested image background color if the
720 * display program does not have its own background color and the image
721 * is needs to composited onto a background before display. The colors
722 * in "background" are normally in the same color space/depth as the
723 * pixel data. Data is valid if (valid & PNG_INFO_bKGD) is non-zero.
724 */
725 png_color_16 background PNG_DEPSTRUCT;
726#endif
727
728#ifdef PNG_oFFs_SUPPORTED
729 /* The oFFs chunk gives the offset in "offset_unit_type" units rightwards
730 * and downwards from the top-left corner of the display, page, or other
731 * application-specific co-ordinate space. See the PNG_OFFSET_ defines
732 * below for the unit types. Valid if (valid & PNG_INFO_oFFs) non-zero.
733 */
734 png_int_32 x_offset PNG_DEPSTRUCT; /* x offset on page */
735 png_int_32 y_offset PNG_DEPSTRUCT; /* y offset on page */
736 png_byte offset_unit_type PNG_DEPSTRUCT; /* offset units type */
737#endif
738
739#ifdef PNG_pHYs_SUPPORTED
740 /* The pHYs chunk gives the physical pixel density of the image for
741 * display or printing in "phys_unit_type" units (see PNG_RESOLUTION_
742 * defines below). Data is valid if (valid & PNG_INFO_pHYs) is non-zero.
743 */
744 png_uint_32 x_pixels_per_unit PNG_DEPSTRUCT; /* horizontal pixel density */
745 png_uint_32 y_pixels_per_unit PNG_DEPSTRUCT; /* vertical pixel density */
746 png_byte phys_unit_type PNG_DEPSTRUCT; /* resolution type (see PNG_RESOLUTION_ below) */
747#endif
748
749#ifdef PNG_hIST_SUPPORTED
750 /* The hIST chunk contains the relative frequency or importance of the
751 * various palette entries, so that a viewer can intelligently select a
752 * reduced-color palette, if required. Data is an array of "num_palette"
753 * values in the range [0,65535]. Data valid if (valid & PNG_INFO_hIST)
754 * is non-zero.
755 */
756 png_uint_16p hist PNG_DEPSTRUCT;
757#endif
758
759#ifdef PNG_cHRM_SUPPORTED
760 /* The cHRM chunk describes the CIE color characteristics of the monitor
761 * on which the PNG was created. This data allows the viewer to do gamut
762 * mapping of the input image to ensure that the viewer sees the same
763 * colors in the image as the creator. Values are in the range
764 * [0.0, 0.8]. Data valid if (valid & PNG_INFO_cHRM) non-zero.
765 */
766#ifdef PNG_FLOATING_POINT_SUPPORTED
767 float x_white PNG_DEPSTRUCT;
768 float y_white PNG_DEPSTRUCT;
769 float x_red PNG_DEPSTRUCT;
770 float y_red PNG_DEPSTRUCT;
771 float x_green PNG_DEPSTRUCT;
772 float y_green PNG_DEPSTRUCT;
773 float x_blue PNG_DEPSTRUCT;
774 float y_blue PNG_DEPSTRUCT;
775#endif
776#endif
777
778#ifdef PNG_pCAL_SUPPORTED
779 /* The pCAL chunk describes a transformation between the stored pixel
780 * values and original physical data values used to create the image.
781 * The integer range [0, 2^bit_depth - 1] maps to the floating-point
782 * range given by [pcal_X0, pcal_X1], and are further transformed by a
783 * (possibly non-linear) transformation function given by "pcal_type"
784 * and "pcal_params" into "pcal_units". Please see the PNG_EQUATION_
785 * defines below, and the PNG-Group's PNG extensions document for a
786 * complete description of the transformations and how they should be
787 * implemented, and for a description of the ASCII parameter strings.
788 * Data values are valid if (valid & PNG_INFO_pCAL) non-zero.
789 */
790 png_charp pcal_purpose PNG_DEPSTRUCT; /* pCAL chunk description string */
791 png_int_32 pcal_X0 PNG_DEPSTRUCT; /* minimum value */
792 png_int_32 pcal_X1 PNG_DEPSTRUCT; /* maximum value */
793 png_charp pcal_units PNG_DEPSTRUCT; /* Latin-1 string giving physical units */
794 png_charpp pcal_params PNG_DEPSTRUCT; /* ASCII strings containing parameter values */
795 png_byte pcal_type PNG_DEPSTRUCT; /* equation type (see PNG_EQUATION_ below) */
796 png_byte pcal_nparams PNG_DEPSTRUCT; /* number of parameters given in pcal_params */
797#endif
798
799/* New members added in libpng-1.0.6 */
800 png_uint_32 free_me PNG_DEPSTRUCT; /* flags items libpng is responsible for freeing */
801
802#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) || \
803 defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
804 /* Storage for unknown chunks that the library doesn't recognize. */
805 png_unknown_chunkp unknown_chunks PNG_DEPSTRUCT;
806 png_size_t unknown_chunks_num PNG_DEPSTRUCT;
807#endif
808
809#ifdef PNG_iCCP_SUPPORTED
810 /* iCCP chunk data. */
811 png_charp iccp_name PNG_DEPSTRUCT; /* profile name */
812 png_charp iccp_profile PNG_DEPSTRUCT; /* International Color Consortium profile data */
813 /* Note to maintainer: should be png_bytep */
814 png_uint_32 iccp_proflen PNG_DEPSTRUCT; /* ICC profile data length */
815 png_byte iccp_compression PNG_DEPSTRUCT; /* Always zero */
816#endif
817
818#ifdef PNG_sPLT_SUPPORTED
819 /* Data on sPLT chunks (there may be more than one). */
820 png_sPLT_tp splt_palettes PNG_DEPSTRUCT;
821 png_uint_32 splt_palettes_num PNG_DEPSTRUCT;
822#endif
823
824#ifdef PNG_sCAL_SUPPORTED
825 /* The sCAL chunk describes the actual physical dimensions of the
826 * subject matter of the graphic. The chunk contains a unit specification
827 * a byte value, and two ASCII strings representing floating-point
828 * values. The values are width and height corresponsing to one pixel
829 * in the image. This external representation is converted to double
830 * here. Data values are valid if (valid & PNG_INFO_sCAL) is non-zero.
831 */
832 png_byte scal_unit PNG_DEPSTRUCT; /* unit of physical scale */
833#ifdef PNG_FLOATING_POINT_SUPPORTED
834 double scal_pixel_width PNG_DEPSTRUCT; /* width of one pixel */
835 double scal_pixel_height PNG_DEPSTRUCT; /* height of one pixel */
836#endif
837#ifdef PNG_FIXED_POINT_SUPPORTED
838 png_charp scal_s_width PNG_DEPSTRUCT; /* string containing height */
839 png_charp scal_s_height PNG_DEPSTRUCT; /* string containing width */
840#endif
841#endif
842
843#ifdef PNG_INFO_IMAGE_SUPPORTED
844 /* Memory has been allocated if (valid & PNG_ALLOCATED_INFO_ROWS) non-zero */
845 /* Data valid if (valid & PNG_INFO_IDAT) non-zero */
846 png_bytepp row_pointers PNG_DEPSTRUCT; /* the image bits */
847#endif
848
849#if defined(PNG_FIXED_POINT_SUPPORTED) && defined(PNG_gAMA_SUPPORTED)
850 png_fixed_point int_gamma PNG_DEPSTRUCT; /* gamma of image, if (valid & PNG_INFO_gAMA) */
851#endif
852
853#if defined(PNG_cHRM_SUPPORTED) && defined(PNG_FIXED_POINT_SUPPORTED)
854 png_fixed_point int_x_white PNG_DEPSTRUCT;
855 png_fixed_point int_y_white PNG_DEPSTRUCT;
856 png_fixed_point int_x_red PNG_DEPSTRUCT;
857 png_fixed_point int_y_red PNG_DEPSTRUCT;
858 png_fixed_point int_x_green PNG_DEPSTRUCT;
859 png_fixed_point int_y_green PNG_DEPSTRUCT;
860 png_fixed_point int_x_blue PNG_DEPSTRUCT;
861 png_fixed_point int_y_blue PNG_DEPSTRUCT;
862#endif
863
864} png_info;
865
866typedef png_info FAR * png_infop;
867typedef png_info FAR * FAR * png_infopp;
868
869/* Maximum positive integer used in PNG is (2^31)-1 */
870#define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL)
871#define PNG_UINT_32_MAX ((png_uint_32)(-1))
872#define PNG_SIZE_MAX ((png_size_t)(-1))
873
874/* These describe the color_type field in png_info. */
875/* color type masks */
876#define PNG_COLOR_MASK_PALETTE 1
877#define PNG_COLOR_MASK_COLOR 2
878#define PNG_COLOR_MASK_ALPHA 4
879
880/* color types. Note that not all combinations are legal */
881#define PNG_COLOR_TYPE_GRAY 0
882#define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
883#define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR)
884#define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
885#define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
886/* aliases */
887#define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA
888#define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA
889
890/* This is for compression type. PNG 1.0-1.2 only define the single type. */
891#define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */
892#define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE
893
894/* This is for filter type. PNG 1.0-1.2 only define the single type. */
895#define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */
896#define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */
897#define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE
898
899/* These are for the interlacing type. These values should NOT be changed. */
900#define PNG_INTERLACE_NONE 0 /* Non-interlaced image */
901#define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */
902#define PNG_INTERLACE_LAST 2 /* Not a valid value */
903
904/* These are for the oFFs chunk. These values should NOT be changed. */
905#define PNG_OFFSET_PIXEL 0 /* Offset in pixels */
906#define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */
907#define PNG_OFFSET_LAST 2 /* Not a valid value */
908
909/* These are for the pCAL chunk. These values should NOT be changed. */
910#define PNG_EQUATION_LINEAR 0 /* Linear transformation */
911#define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */
912#define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */
913#define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */
914#define PNG_EQUATION_LAST 4 /* Not a valid value */
915
916/* These are for the sCAL chunk. These values should NOT be changed. */
917#define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */
918#define PNG_SCALE_METER 1 /* meters per pixel */
919#define PNG_SCALE_RADIAN 2 /* radians per pixel */
920#define PNG_SCALE_LAST 3 /* Not a valid value */
921
922/* These are for the pHYs chunk. These values should NOT be changed. */
923#define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */
924#define PNG_RESOLUTION_METER 1 /* pixels/meter */
925#define PNG_RESOLUTION_LAST 2 /* Not a valid value */
926
927/* These are for the sRGB chunk. These values should NOT be changed. */
928#define PNG_sRGB_INTENT_PERCEPTUAL 0
929#define PNG_sRGB_INTENT_RELATIVE 1
930#define PNG_sRGB_INTENT_SATURATION 2
931#define PNG_sRGB_INTENT_ABSOLUTE 3
932#define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */
933
934/* This is for text chunks */
935#define PNG_KEYWORD_MAX_LENGTH 79
936
937/* Maximum number of entries in PLTE/sPLT/tRNS arrays */
938#define PNG_MAX_PALETTE_LENGTH 256
939
940/* These determine if an ancillary chunk's data has been successfully read
941 * from the PNG header, or if the application has filled in the corresponding
942 * data in the info_struct to be written into the output file. The values
943 * of the PNG_INFO_<chunk> defines should NOT be changed.
944 */
945#define PNG_INFO_gAMA 0x0001
946#define PNG_INFO_sBIT 0x0002
947#define PNG_INFO_cHRM 0x0004
948#define PNG_INFO_PLTE 0x0008
949#define PNG_INFO_tRNS 0x0010
950#define PNG_INFO_bKGD 0x0020
951#define PNG_INFO_hIST 0x0040
952#define PNG_INFO_pHYs 0x0080
953#define PNG_INFO_oFFs 0x0100
954#define PNG_INFO_tIME 0x0200
955#define PNG_INFO_pCAL 0x0400
956#define PNG_INFO_sRGB 0x0800 /* GR-P, 0.96a */
957#define PNG_INFO_iCCP 0x1000 /* ESR, 1.0.6 */
958#define PNG_INFO_sPLT 0x2000 /* ESR, 1.0.6 */
959#define PNG_INFO_sCAL 0x4000 /* ESR, 1.0.6 */
960#define PNG_INFO_IDAT 0x8000L /* ESR, 1.0.6 */
961
962/* This is used for the transformation routines, as some of them
963 * change these values for the row. It also should enable using
964 * the routines for other purposes.
965 */
966typedef struct png_row_info_struct
967{
968 png_uint_32 width; /* width of row */
969 png_size_t rowbytes; /* number of bytes in row */
970 png_byte color_type; /* color type of row */
971 png_byte bit_depth; /* bit depth of row */
972 png_byte channels; /* number of channels (1, 2, 3, or 4) */
973 png_byte pixel_depth; /* bits per pixel (depth * channels) */
974} png_row_info;
975
976typedef png_row_info FAR * png_row_infop;
977typedef png_row_info FAR * FAR * png_row_infopp;
978
979/* These are the function types for the I/O functions and for the functions
980 * that allow the user to override the default I/O functions with his or her
981 * own. The png_error_ptr type should match that of user-supplied warning
982 * and error functions, while the png_rw_ptr type should match that of the
983 * user read/write data functions.
984 */
985typedef struct png_struct_def png_struct;
986typedef png_struct FAR * png_structp;
987
988typedef void (PNGAPI *png_error_ptr) PNGARG((png_structp, png_const_charp));
989typedef void (PNGAPI *png_rw_ptr) PNGARG((png_structp, png_bytep, png_size_t));
990typedef void (PNGAPI *png_flush_ptr) PNGARG((png_structp));
991typedef void (PNGAPI *png_read_status_ptr) PNGARG((png_structp, png_uint_32,
992 int));
993typedef void (PNGAPI *png_write_status_ptr) PNGARG((png_structp, png_uint_32,
994 int));
995
996#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
997typedef void (PNGAPI *png_progressive_info_ptr) PNGARG((png_structp, png_infop));
998typedef void (PNGAPI *png_progressive_end_ptr) PNGARG((png_structp, png_infop));
999typedef void (PNGAPI *png_progressive_row_ptr) PNGARG((png_structp, png_bytep,
1000 png_uint_32, int));
1001#endif
1002
1003#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
1004 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
1005typedef void (PNGAPI *png_user_transform_ptr) PNGARG((png_structp,
1006 png_row_infop, png_bytep));
1007#endif
1008
1009#ifdef PNG_USER_CHUNKS_SUPPORTED
1010typedef int (PNGAPI *png_user_chunk_ptr) PNGARG((png_structp, png_unknown_chunkp));
1011#endif
1012#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
1013typedef void (PNGAPI *png_unknown_chunk_ptr) PNGARG((png_structp));
1014#endif
1015#ifdef PNG_SETJMP_SUPPORTED
1016/* This must match the function definition in <setjmp.h>, and the
1017 * application must include this before png.h to obtain the definition
1018 * of jmp_buf.
1019 */
1020typedef void (PNGAPI *png_longjmp_ptr) PNGARG((jmp_buf, int));
1021#endif
1022
1023/* Transform masks for the high-level interface */
1024#define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */
1025#define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */
1026#define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */
1027#define PNG_TRANSFORM_PACKING 0x0004 /* read and write */
1028#define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */
1029#define PNG_TRANSFORM_EXPAND 0x0010 /* read only */
1030#define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */
1031#define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */
1032#define PNG_TRANSFORM_BGR 0x0080 /* read and write */
1033#define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */
1034#define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */
1035#define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */
1036#define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* write only */
1037/* Added to libpng-1.2.34 */
1038#define PNG_TRANSFORM_STRIP_FILLER_BEFORE PNG_TRANSFORM_STRIP_FILLER
1039#define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */
1040/* Added to libpng-1.4.0 */
1041#define PNG_TRANSFORM_GRAY_TO_RGB 0x2000 /* read only */
1042
1043/* Flags for MNG supported features */
1044#define PNG_FLAG_MNG_EMPTY_PLTE 0x01
1045#define PNG_FLAG_MNG_FILTER_64 0x04
1046#define PNG_ALL_MNG_FEATURES 0x05
1047
1048typedef png_voidp (*png_malloc_ptr) PNGARG((png_structp, png_alloc_size_t));
1049typedef void (*png_free_ptr) PNGARG((png_structp, png_voidp));
1050
1051/* The structure that holds the information to read and write PNG files.
1052 * The only people who need to care about what is inside of this are the
1053 * people who will be modifying the library for their own special needs.
1054 * It should NOT be accessed directly by an application, except to store
1055 * the jmp_buf.
1056 */
1057
1058struct png_struct_def
1059{
1060#ifdef PNG_SETJMP_SUPPORTED
1061 jmp_buf jmpbuf PNG_DEPSTRUCT; /* used in png_error */
1062 png_longjmp_ptr longjmp_fn PNG_DEPSTRUCT;/* setjmp non-local goto function. */
1063#endif
1064 png_error_ptr error_fn PNG_DEPSTRUCT; /* function for printing errors and aborting */
1065 png_error_ptr warning_fn PNG_DEPSTRUCT; /* function for printing warnings */
1066 png_voidp error_ptr PNG_DEPSTRUCT; /* user supplied struct for error functions */
1067 png_rw_ptr write_data_fn PNG_DEPSTRUCT; /* function for writing output data */
1068 png_rw_ptr read_data_fn PNG_DEPSTRUCT; /* function for reading input data */
1069 png_voidp io_ptr PNG_DEPSTRUCT; /* ptr to application struct for I/O functions */
1070
1071#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
1072 png_user_transform_ptr read_user_transform_fn PNG_DEPSTRUCT; /* user read transform */
1073#endif
1074
1075#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
1076 png_user_transform_ptr write_user_transform_fn PNG_DEPSTRUCT; /* user write transform */
1077#endif
1078
1079/* These were added in libpng-1.0.2 */
1080#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
1081#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
1082 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
1083 png_voidp user_transform_ptr PNG_DEPSTRUCT; /* user supplied struct for user transform */
1084 png_byte user_transform_depth PNG_DEPSTRUCT; /* bit depth of user transformed pixels */
1085 png_byte user_transform_channels PNG_DEPSTRUCT; /* channels in user transformed pixels */
1086#endif
1087#endif
1088
1089 png_uint_32 mode PNG_DEPSTRUCT; /* tells us where we are in the PNG file */
1090 png_uint_32 flags PNG_DEPSTRUCT; /* flags indicating various things to libpng */
1091 png_uint_32 transformations PNG_DEPSTRUCT; /* which transformations to perform */
1092
1093 z_stream zstream PNG_DEPSTRUCT; /* pointer to decompression structure (below) */
1094 png_bytep zbuf PNG_DEPSTRUCT; /* buffer for zlib */
1095 png_size_t zbuf_size PNG_DEPSTRUCT; /* size of zbuf */
1096 int zlib_level PNG_DEPSTRUCT; /* holds zlib compression level */
1097 int zlib_method PNG_DEPSTRUCT; /* holds zlib compression method */
1098 int zlib_window_bits PNG_DEPSTRUCT; /* holds zlib compression window bits */
1099 int zlib_mem_level PNG_DEPSTRUCT; /* holds zlib compression memory level */
1100 int zlib_strategy PNG_DEPSTRUCT; /* holds zlib compression strategy */
1101
1102 png_uint_32 width PNG_DEPSTRUCT; /* width of image in pixels */
1103 png_uint_32 height PNG_DEPSTRUCT; /* height of image in pixels */
1104 png_uint_32 num_rows PNG_DEPSTRUCT; /* number of rows in current pass */
1105 png_uint_32 usr_width PNG_DEPSTRUCT; /* width of row at start of write */
1106 png_size_t rowbytes PNG_DEPSTRUCT; /* size of row in bytes */
1107 png_size_t irowbytes PNG_DEPSTRUCT; /* size of current interlaced row in bytes */
1108 png_uint_32 iwidth PNG_DEPSTRUCT; /* width of current interlaced row in pixels */
1109 png_uint_32 row_number PNG_DEPSTRUCT; /* current row in interlace pass */
1110 png_bytep prev_row PNG_DEPSTRUCT; /* buffer to save previous (unfiltered) row */
1111 png_bytep row_buf PNG_DEPSTRUCT; /* buffer to save current (unfiltered) row */
1112 png_bytep sub_row PNG_DEPSTRUCT; /* buffer to save "sub" row when filtering */
1113 png_bytep up_row PNG_DEPSTRUCT; /* buffer to save "up" row when filtering */
1114 png_bytep avg_row PNG_DEPSTRUCT; /* buffer to save "avg" row when filtering */
1115 png_bytep paeth_row PNG_DEPSTRUCT; /* buffer to save "Paeth" row when filtering */
1116 png_row_info row_info PNG_DEPSTRUCT; /* used for transformation routines */
1117
1118 png_uint_32 idat_size PNG_DEPSTRUCT; /* current IDAT size for read */
1119 png_uint_32 crc PNG_DEPSTRUCT; /* current chunk CRC value */
1120 png_colorp palette PNG_DEPSTRUCT; /* palette from the input file */
1121 png_uint_16 num_palette PNG_DEPSTRUCT; /* number of color entries in palette */
1122 png_uint_16 num_trans PNG_DEPSTRUCT; /* number of transparency values */
1123 png_byte chunk_name[5] PNG_DEPSTRUCT; /* null-terminated name of current chunk */
1124 png_byte compression PNG_DEPSTRUCT; /* file compression type (always 0) */
1125 png_byte filter PNG_DEPSTRUCT; /* file filter type (always 0) */
1126 png_byte interlaced PNG_DEPSTRUCT; /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
1127 png_byte pass PNG_DEPSTRUCT; /* current interlace pass (0 - 6) */
1128 png_byte do_filter PNG_DEPSTRUCT; /* row filter flags (see PNG_FILTER_ below ) */
1129 png_byte color_type PNG_DEPSTRUCT; /* color type of file */
1130 png_byte bit_depth PNG_DEPSTRUCT; /* bit depth of file */
1131 png_byte usr_bit_depth PNG_DEPSTRUCT; /* bit depth of users row */
1132 png_byte pixel_depth PNG_DEPSTRUCT; /* number of bits per pixel */
1133 png_byte channels PNG_DEPSTRUCT; /* number of channels in file */
1134 png_byte usr_channels PNG_DEPSTRUCT; /* channels at start of write */
1135 png_byte sig_bytes PNG_DEPSTRUCT; /* magic bytes read/written from start of file */
1136
1137#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
1138 png_uint_16 filler PNG_DEPSTRUCT; /* filler bytes for pixel expansion */
1139#endif
1140
1141#ifdef PNG_bKGD_SUPPORTED
1142 png_byte background_gamma_type PNG_DEPSTRUCT;
1143# ifdef PNG_FLOATING_POINT_SUPPORTED
1144 float background_gamma PNG_DEPSTRUCT;
1145# endif
1146 png_color_16 background PNG_DEPSTRUCT; /* background color in screen gamma space */
1147#ifdef PNG_READ_GAMMA_SUPPORTED
1148 png_color_16 background_1 PNG_DEPSTRUCT; /* background normalized to gamma 1.0 */
1149#endif
1150#endif /* PNG_bKGD_SUPPORTED */
1151
1152#ifdef PNG_WRITE_FLUSH_SUPPORTED
1153 png_flush_ptr output_flush_fn PNG_DEPSTRUCT; /* Function for flushing output */
1154 png_uint_32 flush_dist PNG_DEPSTRUCT; /* how many rows apart to flush, 0 - no flush */
1155 png_uint_32 flush_rows PNG_DEPSTRUCT; /* number of rows written since last flush */
1156#endif
1157
1158#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1159 int gamma_shift PNG_DEPSTRUCT; /* number of "insignificant" bits 16-bit gamma */
1160#ifdef PNG_FLOATING_POINT_SUPPORTED
1161 float gamma PNG_DEPSTRUCT; /* file gamma value */
1162 float screen_gamma PNG_DEPSTRUCT; /* screen gamma value (display_exponent) */
1163#endif
1164#endif
1165
1166#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1167 png_bytep gamma_table PNG_DEPSTRUCT; /* gamma table for 8-bit depth files */
1168 png_bytep gamma_from_1 PNG_DEPSTRUCT; /* converts from 1.0 to screen */
1169 png_bytep gamma_to_1 PNG_DEPSTRUCT; /* converts from file to 1.0 */
1170 png_uint_16pp gamma_16_table PNG_DEPSTRUCT; /* gamma table for 16-bit depth files */
1171 png_uint_16pp gamma_16_from_1 PNG_DEPSTRUCT; /* converts from 1.0 to screen */
1172 png_uint_16pp gamma_16_to_1 PNG_DEPSTRUCT; /* converts from file to 1.0 */
1173#endif
1174
1175#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_sBIT_SUPPORTED)
1176 png_color_8 sig_bit PNG_DEPSTRUCT; /* significant bits in each available channel */
1177#endif
1178
1179#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
1180 png_color_8 shift PNG_DEPSTRUCT; /* shift for significant bit tranformation */
1181#endif
1182
1183#if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \
1184 || defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1185 png_bytep trans_alpha PNG_DEPSTRUCT; /* alpha values for paletted files */
1186 png_color_16 trans_color PNG_DEPSTRUCT; /* transparent color for non-paletted files */
1187#endif
1188
1189 png_read_status_ptr read_row_fn PNG_DEPSTRUCT; /* called after each row is decoded */
1190 png_write_status_ptr write_row_fn PNG_DEPSTRUCT; /* called after each row is encoded */
1191#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1192 png_progressive_info_ptr info_fn PNG_DEPSTRUCT; /* called after header data fully read */
1193 png_progressive_row_ptr row_fn PNG_DEPSTRUCT; /* called after each prog. row is decoded */
1194 png_progressive_end_ptr end_fn PNG_DEPSTRUCT; /* called after image is complete */
1195 png_bytep save_buffer_ptr PNG_DEPSTRUCT; /* current location in save_buffer */
1196 png_bytep save_buffer PNG_DEPSTRUCT; /* buffer for previously read data */
1197 png_bytep current_buffer_ptr PNG_DEPSTRUCT; /* current location in current_buffer */
1198 png_bytep current_buffer PNG_DEPSTRUCT; /* buffer for recently used data */
1199 png_uint_32 push_length PNG_DEPSTRUCT; /* size of current input chunk */
1200 png_uint_32 skip_length PNG_DEPSTRUCT; /* bytes to skip in input data */
1201 png_size_t save_buffer_size PNG_DEPSTRUCT; /* amount of data now in save_buffer */
1202 png_size_t save_buffer_max PNG_DEPSTRUCT; /* total size of save_buffer */
1203 png_size_t buffer_size PNG_DEPSTRUCT; /* total amount of available input data */
1204 png_size_t current_buffer_size PNG_DEPSTRUCT; /* amount of data now in current_buffer */
1205 int process_mode PNG_DEPSTRUCT; /* what push library is currently doing */
1206 int cur_palette PNG_DEPSTRUCT; /* current push library palette index */
1207
1208# ifdef PNG_TEXT_SUPPORTED
1209 png_size_t current_text_size PNG_DEPSTRUCT; /* current size of text input data */
1210 png_size_t current_text_left PNG_DEPSTRUCT; /* how much text left to read in input */
1211 png_charp current_text PNG_DEPSTRUCT; /* current text chunk buffer */
1212 png_charp current_text_ptr PNG_DEPSTRUCT; /* current location in current_text */
1213# endif /* PNG_PROGRESSIVE_READ_SUPPORTED && PNG_TEXT_SUPPORTED */
1214
1215#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
1216
1217#if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
1218/* For the Borland special 64K segment handler */
1219 png_bytepp offset_table_ptr PNG_DEPSTRUCT;
1220 png_bytep offset_table PNG_DEPSTRUCT;
1221 png_uint_16 offset_table_number PNG_DEPSTRUCT;
1222 png_uint_16 offset_table_count PNG_DEPSTRUCT;
1223 png_uint_16 offset_table_count_free PNG_DEPSTRUCT;
1224#endif
1225
1226#ifdef PNG_READ_DITHER_SUPPORTED
1227 png_bytep palette_lookup PNG_DEPSTRUCT; /* lookup table for dithering */
1228 png_bytep dither_index PNG_DEPSTRUCT; /* index translation for palette files */
1229#endif
1230
1231#if defined(PNG_READ_DITHER_SUPPORTED) || defined(PNG_hIST_SUPPORTED)
1232 png_uint_16p hist PNG_DEPSTRUCT; /* histogram */
1233#endif
1234
1235#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
1236 png_byte heuristic_method PNG_DEPSTRUCT; /* heuristic for row filter selection */
1237 png_byte num_prev_filters PNG_DEPSTRUCT; /* number of weights for previous rows */
1238 png_bytep prev_filters PNG_DEPSTRUCT; /* filter type(s) of previous row(s) */
1239 png_uint_16p filter_weights PNG_DEPSTRUCT; /* weight(s) for previous line(s) */
1240 png_uint_16p inv_filter_weights PNG_DEPSTRUCT; /* 1/weight(s) for previous line(s) */
1241 png_uint_16p filter_costs PNG_DEPSTRUCT; /* relative filter calculation cost */
1242 png_uint_16p inv_filter_costs PNG_DEPSTRUCT; /* 1/relative filter calculation cost */
1243#endif
1244
1245#ifdef PNG_TIME_RFC1123_SUPPORTED
1246 png_charp time_buffer PNG_DEPSTRUCT; /* String to hold RFC 1123 time text */
1247#endif
1248
1249/* New members added in libpng-1.0.6 */
1250
1251 png_uint_32 free_me PNG_DEPSTRUCT; /* flags items libpng is responsible for freeing */
1252
1253#ifdef PNG_USER_CHUNKS_SUPPORTED
1254 png_voidp user_chunk_ptr PNG_DEPSTRUCT;
1255 png_user_chunk_ptr read_user_chunk_fn PNG_DEPSTRUCT; /* user read chunk handler */
1256#endif
1257
1258#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
1259 int num_chunk_list PNG_DEPSTRUCT;
1260 png_bytep chunk_list PNG_DEPSTRUCT;
1261#endif
1262
1263/* New members added in libpng-1.0.3 */
1264#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1265 png_byte rgb_to_gray_status PNG_DEPSTRUCT;
1266 /* These were changed from png_byte in libpng-1.0.6 */
1267 png_uint_16 rgb_to_gray_red_coeff PNG_DEPSTRUCT;
1268 png_uint_16 rgb_to_gray_green_coeff PNG_DEPSTRUCT;
1269 png_uint_16 rgb_to_gray_blue_coeff PNG_DEPSTRUCT;
1270#endif
1271
1272/* New member added in libpng-1.0.4 (renamed in 1.0.9) */
1273#if defined(PNG_MNG_FEATURES_SUPPORTED) || \
1274 defined(PNG_READ_EMPTY_PLTE_SUPPORTED) || \
1275 defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
1276/* Changed from png_byte to png_uint_32 at version 1.2.0 */
1277 png_uint_32 mng_features_permitted PNG_DEPSTRUCT;
1278#endif
1279
1280/* New member added in libpng-1.0.7 */
1281#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1282 png_fixed_point int_gamma PNG_DEPSTRUCT;
1283#endif
1284
1285/* New member added in libpng-1.0.9, ifdef'ed out in 1.0.12, enabled in 1.2.0 */
1286#ifdef PNG_MNG_FEATURES_SUPPORTED
1287 png_byte filter_type PNG_DEPSTRUCT;
1288#endif
1289
1290/* New members added in libpng-1.2.0 */
1291
1292/* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */
1293#ifdef PNG_USER_MEM_SUPPORTED
1294 png_voidp mem_ptr PNG_DEPSTRUCT; /* user supplied struct for mem functions */
1295 png_malloc_ptr malloc_fn PNG_DEPSTRUCT; /* function for allocating memory */
1296 png_free_ptr free_fn PNG_DEPSTRUCT; /* function for freeing memory */
1297#endif
1298
1299/* New member added in libpng-1.0.13 and 1.2.0 */
1300 png_bytep big_row_buf PNG_DEPSTRUCT; /* buffer to save current (unfiltered) row */
1301
1302#ifdef PNG_READ_DITHER_SUPPORTED
1303/* The following three members were added at version 1.0.14 and 1.2.4 */
1304 png_bytep dither_sort PNG_DEPSTRUCT; /* working sort array */
1305 png_bytep index_to_palette PNG_DEPSTRUCT; /* where the original index currently is */
1306 /* in the palette */
1307 png_bytep palette_to_index PNG_DEPSTRUCT; /* which original index points to this */
1308 /* palette color */
1309#endif
1310
1311/* New members added in libpng-1.0.16 and 1.2.6 */
1312 png_byte compression_type PNG_DEPSTRUCT;
1313
1314#ifdef PNG_SET_USER_LIMITS_SUPPORTED
1315 png_uint_32 user_width_max PNG_DEPSTRUCT;
1316 png_uint_32 user_height_max PNG_DEPSTRUCT;
1317 /* Added in libpng-1.4.0: Total number of sPLT, text, and unknown
1318 * chunks that can be stored (0x7fffffff means unlimited).
1319 */
1320 png_uint_32 user_chunk_cache_max PNG_DEPSTRUCT;
1321#endif
1322
1323/* New member added in libpng-1.0.25 and 1.2.17 */
1324#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
1325 /* Storage for unknown chunk that the library doesn't recognize. */
1326 png_unknown_chunk unknown_chunk PNG_DEPSTRUCT;
1327#endif
1328
1329/* New members added in libpng-1.2.26 */
1330 png_uint_32 old_big_row_buf_size PNG_DEPSTRUCT;
1331 png_uint_32 old_prev_row_size PNG_DEPSTRUCT;
1332
1333/* New member added in libpng-1.2.30 */
1334 png_charp chunkdata PNG_DEPSTRUCT; /* buffer for reading chunk data */
1335
1336/* New member added in libpng-1.4.0 */
1337#ifdef PNG_IO_STATE_SUPPORTED
1338 png_uint_32 io_state PNG_DEPSTRUCT;
1339#endif
1340};
1341
1342
1343/* This triggers a compiler error in png.c, if png.c and png.h
1344 * do not agree upon the version number.
1345 */
1346typedef png_structp version_1_4_0;
1347
1348typedef png_struct FAR * FAR * png_structpp;
1349
1350/* Here are the function definitions most commonly used. This is not
1351 * the place to find out how to use libpng. See libpng.txt for the
1352 * full explanation, see example.c for the summary. This just provides
1353 * a simple one line description of the use of each function.
1354 */
1355
1356/* Returns the version number of the library */
1357extern PNG_EXPORT(png_uint_32,png_access_version_number) PNGARG((void));
1358
1359/* Tell lib we have already handled the first <num_bytes> magic bytes.
1360 * Handling more than 8 bytes from the beginning of the file is an error.
1361 */
1362extern PNG_EXPORT(void,png_set_sig_bytes) PNGARG((png_structp png_ptr,
1363 int num_bytes));
1364
1365/* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
1366 * PNG file. Returns zero if the supplied bytes match the 8-byte PNG
1367 * signature, and non-zero otherwise. Having num_to_check == 0 or
1368 * start > 7 will always fail (ie return non-zero).
1369 */
1370extern PNG_EXPORT(int,png_sig_cmp) PNGARG((png_bytep sig, png_size_t start,
1371 png_size_t num_to_check));
1372
1373/* Allocate and initialize png_ptr struct for reading, and any other memory. */
1374extern PNG_EXPORT(png_structp,png_create_read_struct)
1375 PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1376 png_error_ptr error_fn, png_error_ptr warn_fn)) PNG_ALLOCATED;
1377
1378/* Allocate and initialize png_ptr struct for writing, and any other memory */
1379extern PNG_EXPORT(png_structp,png_create_write_struct)
1380 PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1381 png_error_ptr error_fn, png_error_ptr warn_fn)) PNG_ALLOCATED;
1382
1383#ifdef PNG_WRITE_SUPPORTED
1384extern PNG_EXPORT(png_size_t,png_get_compression_buffer_size)
1385 PNGARG((png_structp png_ptr));
1386#endif
1387
1388#ifdef PNG_WRITE_SUPPORTED
1389extern PNG_EXPORT(void,png_set_compression_buffer_size)
1390 PNGARG((png_structp png_ptr, png_size_t size));
1391#endif
1392
1393/* Moved from pngconf.h in 1.4.0 and modified to ensure setjmp/longjmp
1394 * match up.
1395 */
1396#ifdef PNG_SETJMP_SUPPORTED
1397/* This function returns the jmp_buf built in to *png_ptr. It must be
1398 * supplied with an appropriate 'longjmp' function to use on that jmp_buf
1399 * unless the default error function is overridden in which case NULL is
1400 * acceptable. The size of the jmp_buf is checked against the actual size
1401 * allocated by the library - the call will return NULL on a mismatch
1402 * indicating an ABI mismatch.
1403 */
1404extern PNG_EXPORT(jmp_buf*, png_set_longjmp_fn)
1405 PNGARG((png_structp png_ptr, png_longjmp_ptr longjmp_fn, size_t jmp_buf_size));
1406# define png_jmpbuf(png_ptr) \
1407 (*png_set_longjmp_fn((png_ptr), longjmp, sizeof (jmp_buf)))
1408#else
1409# define png_jmpbuf(png_ptr) \
1410 (LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP)
1411#endif
1412
1413/* Reset the compression stream */
1414extern PNG_EXPORT(int,png_reset_zstream) PNGARG((png_structp png_ptr));
1415
1416/* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */
1417#ifdef PNG_USER_MEM_SUPPORTED
1418extern PNG_EXPORT(png_structp,png_create_read_struct_2)
1419 PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1420 png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
1421 png_malloc_ptr malloc_fn, png_free_ptr free_fn)) PNG_ALLOCATED;
1422extern PNG_EXPORT(png_structp,png_create_write_struct_2)
1423 PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1424 png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
1425 png_malloc_ptr malloc_fn, png_free_ptr free_fn)) PNG_ALLOCATED;
1426#endif
1427
1428/* Write the PNG file signature. */
1429extern PNG_EXPORT(void,png_write_sig) PNGARG((png_structp png_ptr));
1430
1431/* Write a PNG chunk - size, type, (optional) data, CRC. */
1432extern PNG_EXPORT(void,png_write_chunk) PNGARG((png_structp png_ptr,
1433 png_bytep chunk_name, png_bytep data, png_size_t length));
1434
1435/* Write the start of a PNG chunk - length and chunk name. */
1436extern PNG_EXPORT(void,png_write_chunk_start) PNGARG((png_structp png_ptr,
1437 png_bytep chunk_name, png_uint_32 length));
1438
1439/* Write the data of a PNG chunk started with png_write_chunk_start(). */
1440extern PNG_EXPORT(void,png_write_chunk_data) PNGARG((png_structp png_ptr,
1441 png_bytep data, png_size_t length));
1442
1443/* Finish a chunk started with png_write_chunk_start() (includes CRC). */
1444extern PNG_EXPORT(void,png_write_chunk_end) PNGARG((png_structp png_ptr));
1445
1446/* Allocate and initialize the info structure */
1447extern PNG_EXPORT(png_infop,png_create_info_struct)
1448 PNGARG((png_structp png_ptr)) PNG_ALLOCATED;
1449
1450extern PNG_EXPORT(void,png_info_init_3) PNGARG((png_infopp info_ptr,
1451 png_size_t png_info_struct_size));
1452
1453/* Writes all the PNG information before the image. */
1454extern PNG_EXPORT(void,png_write_info_before_PLTE) PNGARG((png_structp png_ptr,
1455 png_infop info_ptr));
1456extern PNG_EXPORT(void,png_write_info) PNGARG((png_structp png_ptr,
1457 png_infop info_ptr));
1458
1459#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1460/* Read the information before the actual image data. */
1461extern PNG_EXPORT(void,png_read_info) PNGARG((png_structp png_ptr,
1462 png_infop info_ptr));
1463#endif
1464
1465#ifdef PNG_TIME_RFC1123_SUPPORTED
1466extern PNG_EXPORT(png_charp,png_convert_to_rfc1123)
1467 PNGARG((png_structp png_ptr, png_timep ptime));
1468#endif
1469
1470#ifdef PNG_CONVERT_tIME_SUPPORTED
1471/* Convert from a struct tm to png_time */
1472extern PNG_EXPORT(void,png_convert_from_struct_tm) PNGARG((png_timep ptime,
1473 struct tm FAR * ttime));
1474
1475/* Convert from time_t to png_time. Uses gmtime() */
1476extern PNG_EXPORT(void,png_convert_from_time_t) PNGARG((png_timep ptime,
1477 time_t ttime));
1478#endif /* PNG_CONVERT_tIME_SUPPORTED */
1479
1480#ifdef PNG_READ_EXPAND_SUPPORTED
1481/* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
1482extern PNG_EXPORT(void,png_set_expand) PNGARG((png_structp png_ptr));
1483extern PNG_EXPORT(void,png_set_expand_gray_1_2_4_to_8) PNGARG((png_structp
1484 png_ptr));
1485extern PNG_EXPORT(void,png_set_palette_to_rgb) PNGARG((png_structp png_ptr));
1486extern PNG_EXPORT(void,png_set_tRNS_to_alpha) PNGARG((png_structp png_ptr));
1487#endif
1488
1489#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
1490/* Use blue, green, red order for pixels. */
1491extern PNG_EXPORT(void,png_set_bgr) PNGARG((png_structp png_ptr));
1492#endif
1493
1494#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
1495/* Expand the grayscale to 24-bit RGB if necessary. */
1496extern PNG_EXPORT(void,png_set_gray_to_rgb) PNGARG((png_structp png_ptr));
1497#endif
1498
1499#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1500/* Reduce RGB to grayscale. */
1501#ifdef PNG_FLOATING_POINT_SUPPORTED
1502extern PNG_EXPORT(void,png_set_rgb_to_gray) PNGARG((png_structp png_ptr,
1503 int error_action, double red, double green ));
1504#endif
1505extern PNG_EXPORT(void,png_set_rgb_to_gray_fixed) PNGARG((png_structp png_ptr,
1506 int error_action, png_fixed_point red, png_fixed_point green ));
1507extern PNG_EXPORT(png_byte,png_get_rgb_to_gray_status) PNGARG((png_structp
1508 png_ptr));
1509#endif
1510
1511extern PNG_EXPORT(void,png_build_grayscale_palette) PNGARG((int bit_depth,
1512 png_colorp palette));
1513
1514#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
1515extern PNG_EXPORT(void,png_set_strip_alpha) PNGARG((png_structp png_ptr));
1516#endif
1517
1518#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
1519 defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
1520extern PNG_EXPORT(void,png_set_swap_alpha) PNGARG((png_structp png_ptr));
1521#endif
1522
1523#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
1524 defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
1525extern PNG_EXPORT(void,png_set_invert_alpha) PNGARG((png_structp png_ptr));
1526#endif
1527
1528#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
1529/* Add a filler byte to 8-bit Gray or 24-bit RGB images. */
1530extern PNG_EXPORT(void,png_set_filler) PNGARG((png_structp png_ptr,
1531 png_uint_32 filler, int flags));
1532/* The values of the PNG_FILLER_ defines should NOT be changed */
1533#define PNG_FILLER_BEFORE 0
1534#define PNG_FILLER_AFTER 1
1535/* Add an alpha byte to 8-bit Gray or 24-bit RGB images. */
1536extern PNG_EXPORT(void,png_set_add_alpha) PNGARG((png_structp png_ptr,
1537 png_uint_32 filler, int flags));
1538#endif /* PNG_READ_FILLER_SUPPORTED || PNG_WRITE_FILLER_SUPPORTED */
1539
1540#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
1541/* Swap bytes in 16-bit depth files. */
1542extern PNG_EXPORT(void,png_set_swap) PNGARG((png_structp png_ptr));
1543#endif
1544
1545#if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
1546/* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
1547extern PNG_EXPORT(void,png_set_packing) PNGARG((png_structp png_ptr));
1548#endif
1549
1550#if defined(PNG_READ_PACKSWAP_SUPPORTED) || defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1551/* Swap packing order of pixels in bytes. */
1552extern PNG_EXPORT(void,png_set_packswap) PNGARG((png_structp png_ptr));
1553#endif
1554
1555#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
1556/* Converts files to legal bit depths. */
1557extern PNG_EXPORT(void,png_set_shift) PNGARG((png_structp png_ptr,
1558 png_color_8p true_bits));
1559#endif
1560
1561#if defined(PNG_READ_INTERLACING_SUPPORTED) || \
1562 defined(PNG_WRITE_INTERLACING_SUPPORTED)
1563/* Have the code handle the interlacing. Returns the number of passes. */
1564extern PNG_EXPORT(int,png_set_interlace_handling) PNGARG((png_structp png_ptr));
1565#endif
1566
1567#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
1568/* Invert monochrome files */
1569extern PNG_EXPORT(void,png_set_invert_mono) PNGARG((png_structp png_ptr));
1570#endif
1571
1572#ifdef PNG_READ_BACKGROUND_SUPPORTED
1573/* Handle alpha and tRNS by replacing with a background color. */
1574#ifdef PNG_FLOATING_POINT_SUPPORTED
1575extern PNG_EXPORT(void,png_set_background) PNGARG((png_structp png_ptr,
1576 png_color_16p background_color, int background_gamma_code,
1577 int need_expand, double background_gamma));
1578#endif
1579#define PNG_BACKGROUND_GAMMA_UNKNOWN 0
1580#define PNG_BACKGROUND_GAMMA_SCREEN 1
1581#define PNG_BACKGROUND_GAMMA_FILE 2
1582#define PNG_BACKGROUND_GAMMA_UNIQUE 3
1583#endif
1584
1585#ifdef PNG_READ_16_TO_8_SUPPORTED
1586/* Strip the second byte of information from a 16-bit depth file. */
1587extern PNG_EXPORT(void,png_set_strip_16) PNGARG((png_structp png_ptr));
1588#endif
1589
1590#ifdef PNG_READ_DITHER_SUPPORTED
1591/* Turn on dithering, and reduce the palette to the number of colors available. */
1592extern PNG_EXPORT(void,png_set_dither) PNGARG((png_structp png_ptr,
1593 png_colorp palette, int num_palette, int maximum_colors,
1594 png_uint_16p histogram, int full_dither));
1595#endif
1596
1597#ifdef PNG_READ_GAMMA_SUPPORTED
1598/* Handle gamma correction. Screen_gamma=(display_exponent) */
1599#ifdef PNG_FLOATING_POINT_SUPPORTED
1600extern PNG_EXPORT(void,png_set_gamma) PNGARG((png_structp png_ptr,
1601 double screen_gamma, double default_file_gamma));
1602#endif
1603#endif
1604
1605
1606#ifdef PNG_WRITE_FLUSH_SUPPORTED
1607/* Set how many lines between output flushes - 0 for no flushing */
1608extern PNG_EXPORT(void,png_set_flush) PNGARG((png_structp png_ptr, int nrows));
1609/* Flush the current PNG output buffer */
1610extern PNG_EXPORT(void,png_write_flush) PNGARG((png_structp png_ptr));
1611#endif
1612
1613/* Optional update palette with requested transformations */
1614extern PNG_EXPORT(void,png_start_read_image) PNGARG((png_structp png_ptr));
1615
1616/* Optional call to update the users info structure */
1617extern PNG_EXPORT(void,png_read_update_info) PNGARG((png_structp png_ptr,
1618 png_infop info_ptr));
1619
1620#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1621/* Read one or more rows of image data. */
1622extern PNG_EXPORT(void,png_read_rows) PNGARG((png_structp png_ptr,
1623 png_bytepp row, png_bytepp display_row, png_uint_32 num_rows));
1624#endif
1625
1626#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1627/* Read a row of data. */
1628extern PNG_EXPORT(void,png_read_row) PNGARG((png_structp png_ptr,
1629 png_bytep row,
1630 png_bytep display_row));
1631#endif
1632
1633#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1634/* Read the whole image into memory at once. */
1635extern PNG_EXPORT(void,png_read_image) PNGARG((png_structp png_ptr,
1636 png_bytepp image));
1637#endif
1638
1639/* Write a row of image data */
1640extern PNG_EXPORT(void,png_write_row) PNGARG((png_structp png_ptr,
1641 png_bytep row));
1642
1643/* Write a few rows of image data */
1644extern PNG_EXPORT(void,png_write_rows) PNGARG((png_structp png_ptr,
1645 png_bytepp row, png_uint_32 num_rows));
1646
1647/* Write the image data */
1648extern PNG_EXPORT(void,png_write_image) PNGARG((png_structp png_ptr,
1649 png_bytepp image));
1650
1651/* Write the end of the PNG file. */
1652extern PNG_EXPORT(void,png_write_end) PNGARG((png_structp png_ptr,
1653 png_infop info_ptr));
1654
1655#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1656/* Read the end of the PNG file. */
1657extern PNG_EXPORT(void,png_read_end) PNGARG((png_structp png_ptr,
1658 png_infop info_ptr));
1659#endif
1660
1661/* Free any memory associated with the png_info_struct */
1662extern PNG_EXPORT(void,png_destroy_info_struct) PNGARG((png_structp png_ptr,
1663 png_infopp info_ptr_ptr));
1664
1665/* Free any memory associated with the png_struct and the png_info_structs */
1666extern PNG_EXPORT(void,png_destroy_read_struct) PNGARG((png_structpp
1667 png_ptr_ptr, png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr));
1668
1669/* Free any memory associated with the png_struct and the png_info_structs */
1670extern PNG_EXPORT(void,png_destroy_write_struct)
1671 PNGARG((png_structpp png_ptr_ptr, png_infopp info_ptr_ptr));
1672
1673/* Set the libpng method of handling chunk CRC errors */
1674extern PNG_EXPORT(void,png_set_crc_action) PNGARG((png_structp png_ptr,
1675 int crit_action, int ancil_action));
1676
1677/* Values for png_set_crc_action() to say how to handle CRC errors in
1678 * ancillary and critical chunks, and whether to use the data contained
1679 * therein. Note that it is impossible to "discard" data in a critical
1680 * chunk. For versions prior to 0.90, the action was always error/quit,
1681 * whereas in version 0.90 and later, the action for CRC errors in ancillary
1682 * chunks is warn/discard. These values should NOT be changed.
1683 *
1684 * value action:critical action:ancillary
1685 */
1686#define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */
1687#define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */
1688#define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */
1689#define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */
1690#define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */
1691#define PNG_CRC_NO_CHANGE 5 /* use current value use current value */
1692
1693/* These functions give the user control over the scan-line filtering in
1694 * libpng and the compression methods used by zlib. These functions are
1695 * mainly useful for testing, as the defaults should work with most users.
1696 * Those users who are tight on memory or want faster performance at the
1697 * expense of compression can modify them. See the compression library
1698 * header file (zlib.h) for an explination of the compression functions.
1699 */
1700
1701/* Set the filtering method(s) used by libpng. Currently, the only valid
1702 * value for "method" is 0.
1703 */
1704extern PNG_EXPORT(void,png_set_filter) PNGARG((png_structp png_ptr, int method,
1705 int filters));
1706
1707/* Flags for png_set_filter() to say which filters to use. The flags
1708 * are chosen so that they don't conflict with real filter types
1709 * below, in case they are supplied instead of the #defined constants.
1710 * These values should NOT be changed.
1711 */
1712#define PNG_NO_FILTERS 0x00
1713#define PNG_FILTER_NONE 0x08
1714#define PNG_FILTER_SUB 0x10
1715#define PNG_FILTER_UP 0x20
1716#define PNG_FILTER_AVG 0x40
1717#define PNG_FILTER_PAETH 0x80
1718#define PNG_ALL_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP | \
1719 PNG_FILTER_AVG | PNG_FILTER_PAETH)
1720
1721/* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
1722 * These defines should NOT be changed.
1723 */
1724#define PNG_FILTER_VALUE_NONE 0
1725#define PNG_FILTER_VALUE_SUB 1
1726#define PNG_FILTER_VALUE_UP 2
1727#define PNG_FILTER_VALUE_AVG 3
1728#define PNG_FILTER_VALUE_PAETH 4
1729#define PNG_FILTER_VALUE_LAST 5
1730
1731#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* EXPERIMENTAL */
1732/* The "heuristic_method" is given by one of the PNG_FILTER_HEURISTIC_
1733 * defines, either the default (minimum-sum-of-absolute-differences), or
1734 * the experimental method (weighted-minimum-sum-of-absolute-differences).
1735 *
1736 * Weights are factors >= 1.0, indicating how important it is to keep the
1737 * filter type consistent between rows. Larger numbers mean the current
1738 * filter is that many times as likely to be the same as the "num_weights"
1739 * previous filters. This is cumulative for each previous row with a weight.
1740 * There needs to be "num_weights" values in "filter_weights", or it can be
1741 * NULL if the weights aren't being specified. Weights have no influence on
1742 * the selection of the first row filter. Well chosen weights can (in theory)
1743 * improve the compression for a given image.
1744 *
1745 * Costs are factors >= 1.0 indicating the relative decoding costs of a
1746 * filter type. Higher costs indicate more decoding expense, and are
1747 * therefore less likely to be selected over a filter with lower computational
1748 * costs. There needs to be a value in "filter_costs" for each valid filter
1749 * type (given by PNG_FILTER_VALUE_LAST), or it can be NULL if you aren't
1750 * setting the costs. Costs try to improve the speed of decompression without
1751 * unduly increasing the compressed image size.
1752 *
1753 * A negative weight or cost indicates the default value is to be used, and
1754 * values in the range [0.0, 1.0) indicate the value is to remain unchanged.
1755 * The default values for both weights and costs are currently 1.0, but may
1756 * change if good general weighting/cost heuristics can be found. If both
1757 * the weights and costs are set to 1.0, this degenerates the WEIGHTED method
1758 * to the UNWEIGHTED method, but with added encoding time/computation.
1759 */
1760#ifdef PNG_FLOATING_POINT_SUPPORTED
1761extern PNG_EXPORT(void,png_set_filter_heuristics) PNGARG((png_structp png_ptr,
1762 int heuristic_method, int num_weights, png_doublep filter_weights,
1763 png_doublep filter_costs));
1764#endif
1765#endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
1766
1767/* Heuristic used for row filter selection. These defines should NOT be
1768 * changed.
1769 */
1770#define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */
1771#define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */
1772#define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */
1773#define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */
1774
1775/* Set the library compression level. Currently, valid values range from
1776 * 0 - 9, corresponding directly to the zlib compression levels 0 - 9
1777 * (0 - no compression, 9 - "maximal" compression). Note that tests have
1778 * shown that zlib compression levels 3-6 usually perform as well as level 9
1779 * for PNG images, and do considerably fewer caclulations. In the future,
1780 * these values may not correspond directly to the zlib compression levels.
1781 */
1782extern PNG_EXPORT(void,png_set_compression_level) PNGARG((png_structp png_ptr,
1783 int level));
1784
1785extern PNG_EXPORT(void,png_set_compression_mem_level)
1786 PNGARG((png_structp png_ptr, int mem_level));
1787
1788extern PNG_EXPORT(void,png_set_compression_strategy)
1789 PNGARG((png_structp png_ptr, int strategy));
1790
1791extern PNG_EXPORT(void,png_set_compression_window_bits)
1792 PNGARG((png_structp png_ptr, int window_bits));
1793
1794extern PNG_EXPORT(void,png_set_compression_method) PNGARG((png_structp png_ptr,
1795 int method));
1796
1797/* These next functions are called for input/output, memory, and error
1798 * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c,
1799 * and call standard C I/O routines such as fread(), fwrite(), and
1800 * fprintf(). These functions can be made to use other I/O routines
1801 * at run time for those applications that need to handle I/O in a
1802 * different manner by calling png_set_???_fn(). See libpng.txt for
1803 * more information.
1804 */
1805
1806#ifdef PNG_STDIO_SUPPORTED
1807/* Initialize the input/output for the PNG file to the default functions. */
1808extern PNG_EXPORT(void,png_init_io) PNGARG((png_structp png_ptr, png_FILE_p fp));
1809#endif
1810
1811/* Replace the (error and abort), and warning functions with user
1812 * supplied functions. If no messages are to be printed you must still
1813 * write and use replacement functions. The replacement error_fn should
1814 * still do a longjmp to the last setjmp location if you are using this
1815 * method of error handling. If error_fn or warning_fn is NULL, the
1816 * default function will be used.
1817 */
1818
1819extern PNG_EXPORT(void,png_set_error_fn) PNGARG((png_structp png_ptr,
1820 png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn));
1821
1822/* Return the user pointer associated with the error functions */
1823extern PNG_EXPORT(png_voidp,png_get_error_ptr) PNGARG((png_structp png_ptr));
1824
1825/* Replace the default data output functions with a user supplied one(s).
1826 * If buffered output is not used, then output_flush_fn can be set to NULL.
1827 * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time
1828 * output_flush_fn will be ignored (and thus can be NULL).
1829 * It is probably a mistake to use NULL for output_flush_fn if
1830 * write_data_fn is not also NULL unless you have built libpng with
1831 * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's
1832 * default flush function, which uses the standard *FILE structure, will
1833 * be used.
1834 */
1835extern PNG_EXPORT(void,png_set_write_fn) PNGARG((png_structp png_ptr,
1836 png_voidp io_ptr, png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn));
1837
1838/* Replace the default data input function with a user supplied one. */
1839extern PNG_EXPORT(void,png_set_read_fn) PNGARG((png_structp png_ptr,
1840 png_voidp io_ptr, png_rw_ptr read_data_fn));
1841
1842/* Return the user pointer associated with the I/O functions */
1843extern PNG_EXPORT(png_voidp,png_get_io_ptr) PNGARG((png_structp png_ptr));
1844
1845extern PNG_EXPORT(void,png_set_read_status_fn) PNGARG((png_structp png_ptr,
1846 png_read_status_ptr read_row_fn));
1847
1848extern PNG_EXPORT(void,png_set_write_status_fn) PNGARG((png_structp png_ptr,
1849 png_write_status_ptr write_row_fn));
1850
1851#ifdef PNG_USER_MEM_SUPPORTED
1852/* Replace the default memory allocation functions with user supplied one(s). */
1853extern PNG_EXPORT(void,png_set_mem_fn) PNGARG((png_structp png_ptr,
1854 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn));
1855/* Return the user pointer associated with the memory functions */
1856extern PNG_EXPORT(png_voidp,png_get_mem_ptr) PNGARG((png_structp png_ptr));
1857#endif
1858
1859#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
1860extern PNG_EXPORT(void,png_set_read_user_transform_fn) PNGARG((png_structp
1861 png_ptr, png_user_transform_ptr read_user_transform_fn));
1862#endif
1863
1864#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
1865extern PNG_EXPORT(void,png_set_write_user_transform_fn) PNGARG((png_structp
1866 png_ptr, png_user_transform_ptr write_user_transform_fn));
1867#endif
1868
1869#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
1870 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
1871extern PNG_EXPORT(void,png_set_user_transform_info) PNGARG((png_structp
1872 png_ptr, png_voidp user_transform_ptr, int user_transform_depth,
1873 int user_transform_channels));
1874/* Return the user pointer associated with the user transform functions */
1875extern PNG_EXPORT(png_voidp,png_get_user_transform_ptr)
1876 PNGARG((png_structp png_ptr));
1877#endif
1878
1879#ifdef PNG_USER_CHUNKS_SUPPORTED
1880extern PNG_EXPORT(void,png_set_read_user_chunk_fn) PNGARG((png_structp png_ptr,
1881 png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));
1882extern PNG_EXPORT(png_voidp,png_get_user_chunk_ptr) PNGARG((png_structp
1883 png_ptr));
1884#endif
1885
1886#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1887/* Sets the function callbacks for the push reader, and a pointer to a
1888 * user-defined structure available to the callback functions.
1889 */
1890extern PNG_EXPORT(void,png_set_progressive_read_fn) PNGARG((png_structp png_ptr,
1891 png_voidp progressive_ptr,
1892 png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
1893 png_progressive_end_ptr end_fn));
1894
1895/* Returns the user pointer associated with the push read functions */
1896extern PNG_EXPORT(png_voidp,png_get_progressive_ptr)
1897 PNGARG((png_structp png_ptr));
1898
1899/* Function to be called when data becomes available */
1900extern PNG_EXPORT(void,png_process_data) PNGARG((png_structp png_ptr,
1901 png_infop info_ptr, png_bytep buffer, png_size_t buffer_size));
1902
1903/* Function that combines rows. Not very much different than the
1904 * png_combine_row() call. Is this even used?????
1905 */
1906extern PNG_EXPORT(void,png_progressive_combine_row) PNGARG((png_structp png_ptr,
1907 png_bytep old_row, png_bytep new_row));
1908#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
1909
1910extern PNG_EXPORT(png_voidp,png_malloc) PNGARG((png_structp png_ptr,
1911 png_alloc_size_t size)) PNG_ALLOCATED;
1912/* Added at libpng version 1.4.0 */
1913extern PNG_EXPORT(png_voidp,png_calloc) PNGARG((png_structp png_ptr,
1914 png_alloc_size_t size)) PNG_ALLOCATED;
1915
1916/* Added at libpng version 1.2.4 */
1917extern PNG_EXPORT(png_voidp,png_malloc_warn) PNGARG((png_structp png_ptr,
1918 png_alloc_size_t size)) PNG_ALLOCATED;
1919
1920/* Frees a pointer allocated by png_malloc() */
1921extern PNG_EXPORT(void,png_free) PNGARG((png_structp png_ptr, png_voidp ptr));
1922
1923/* Free data that was allocated internally */
1924extern PNG_EXPORT(void,png_free_data) PNGARG((png_structp png_ptr,
1925 png_infop info_ptr, png_uint_32 free_me, int num));
1926/* Reassign responsibility for freeing existing data, whether allocated
1927 * by libpng or by the application */
1928extern PNG_EXPORT(void,png_data_freer) PNGARG((png_structp png_ptr,
1929 png_infop info_ptr, int freer, png_uint_32 mask));
1930/* Assignments for png_data_freer */
1931#define PNG_DESTROY_WILL_FREE_DATA 1
1932#define PNG_SET_WILL_FREE_DATA 1
1933#define PNG_USER_WILL_FREE_DATA 2
1934/* Flags for png_ptr->free_me and info_ptr->free_me */
1935#define PNG_FREE_HIST 0x0008
1936#define PNG_FREE_ICCP 0x0010
1937#define PNG_FREE_SPLT 0x0020
1938#define PNG_FREE_ROWS 0x0040
1939#define PNG_FREE_PCAL 0x0080
1940#define PNG_FREE_SCAL 0x0100
1941#define PNG_FREE_UNKN 0x0200
1942#define PNG_FREE_LIST 0x0400
1943#define PNG_FREE_PLTE 0x1000
1944#define PNG_FREE_TRNS 0x2000
1945#define PNG_FREE_TEXT 0x4000
1946#define PNG_FREE_ALL 0x7fff
1947#define PNG_FREE_MUL 0x4220 /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */
1948
1949#ifdef PNG_USER_MEM_SUPPORTED
1950extern PNG_EXPORT(png_voidp,png_malloc_default) PNGARG((png_structp png_ptr,
1951 png_alloc_size_t size)) PNG_ALLOCATED;
1952extern PNG_EXPORT(void,png_free_default) PNGARG((png_structp png_ptr,
1953 png_voidp ptr));
1954#endif
1955
1956#ifndef PNG_NO_ERROR_TEXT
1957/* Fatal error in PNG image of libpng - can't continue */
1958extern PNG_EXPORT(void,png_error) PNGARG((png_structp png_ptr,
1959 png_const_charp error_message)) PNG_NORETURN;
1960
1961/* The same, but the chunk name is prepended to the error string. */
1962extern PNG_EXPORT(void,png_chunk_error) PNGARG((png_structp png_ptr,
1963 png_const_charp error_message)) PNG_NORETURN;
1964
1965#else
1966/* Fatal error in PNG image of libpng - can't continue */
1967extern PNG_EXPORT(void,png_err) PNGARG((png_structp png_ptr)) PNG_NORETURN;
1968#endif
1969
1970/* Non-fatal error in libpng. Can continue, but may have a problem. */
1971extern PNG_EXPORT(void,png_warning) PNGARG((png_structp png_ptr,
1972 png_const_charp warning_message));
1973
1974/* Non-fatal error in libpng, chunk name is prepended to message. */
1975extern PNG_EXPORT(void,png_chunk_warning) PNGARG((png_structp png_ptr,
1976 png_const_charp warning_message));
1977
1978#ifdef PNG_BENIGN_ERRORS_SUPPORTED
1979/* Benign error in libpng. Can continue, but may have a problem.
1980 * User can choose whether to handle as a fatal error or as a warning. */
1981extern PNG_EXPORT(void,png_benign_error) PNGARG((png_structp png_ptr,
1982 png_const_charp warning_message));
1983
1984/* Same, chunk name is prepended to message. */
1985extern PNG_EXPORT(void,png_chunk_benign_error) PNGARG((png_structp png_ptr,
1986 png_const_charp warning_message));
1987
1988extern PNG_EXPORT(void,png_set_benign_errors) PNGARG((png_structp
1989 png_ptr, int allowed));
1990#endif
1991
1992/* The png_set_<chunk> functions are for storing values in the png_info_struct.
1993 * Similarly, the png_get_<chunk> calls are used to read values from the
1994 * png_info_struct, either storing the parameters in the passed variables, or
1995 * setting pointers into the png_info_struct where the data is stored. The
1996 * png_get_<chunk> functions return a non-zero value if the data was available
1997 * in info_ptr, or return zero and do not change any of the parameters if the
1998 * data was not available.
1999 *
2000 * These functions should be used instead of directly accessing png_info
2001 * to avoid problems with future changes in the size and internal layout of
2002 * png_info_struct.
2003 */
2004/* Returns "flag" if chunk data is valid in info_ptr. */
2005extern PNG_EXPORT(png_uint_32,png_get_valid) PNGARG((png_structp png_ptr,
2006png_infop info_ptr, png_uint_32 flag));
2007
2008/* Returns number of bytes needed to hold a transformed row. */
2009extern PNG_EXPORT(png_size_t,png_get_rowbytes) PNGARG((png_structp png_ptr,
2010png_infop info_ptr));
2011
2012#ifdef PNG_INFO_IMAGE_SUPPORTED
2013/* Returns row_pointers, which is an array of pointers to scanlines that was
2014 * returned from png_read_png().
2015 */
2016extern PNG_EXPORT(png_bytepp,png_get_rows) PNGARG((png_structp png_ptr,
2017png_infop info_ptr));
2018/* Set row_pointers, which is an array of pointers to scanlines for use
2019 * by png_write_png().
2020 */
2021extern PNG_EXPORT(void,png_set_rows) PNGARG((png_structp png_ptr,
2022 png_infop info_ptr, png_bytepp row_pointers));
2023#endif
2024
2025/* Returns number of color channels in image. */
2026extern PNG_EXPORT(png_byte,png_get_channels) PNGARG((png_structp png_ptr,
2027png_infop info_ptr));
2028
2029#ifdef PNG_EASY_ACCESS_SUPPORTED
2030/* Returns image width in pixels. */
2031extern PNG_EXPORT(png_uint_32, png_get_image_width) PNGARG((png_structp
2032png_ptr, png_infop info_ptr));
2033
2034/* Returns image height in pixels. */
2035extern PNG_EXPORT(png_uint_32, png_get_image_height) PNGARG((png_structp
2036png_ptr, png_infop info_ptr));
2037
2038/* Returns image bit_depth. */
2039extern PNG_EXPORT(png_byte, png_get_bit_depth) PNGARG((png_structp
2040png_ptr, png_infop info_ptr));
2041
2042/* Returns image color_type. */
2043extern PNG_EXPORT(png_byte, png_get_color_type) PNGARG((png_structp
2044png_ptr, png_infop info_ptr));
2045
2046/* Returns image filter_type. */
2047extern PNG_EXPORT(png_byte, png_get_filter_type) PNGARG((png_structp
2048png_ptr, png_infop info_ptr));
2049
2050/* Returns image interlace_type. */
2051extern PNG_EXPORT(png_byte, png_get_interlace_type) PNGARG((png_structp
2052png_ptr, png_infop info_ptr));
2053
2054/* Returns image compression_type. */
2055extern PNG_EXPORT(png_byte, png_get_compression_type) PNGARG((png_structp
2056png_ptr, png_infop info_ptr));
2057
2058/* Returns image resolution in pixels per meter, from pHYs chunk data. */
2059extern PNG_EXPORT(png_uint_32, png_get_pixels_per_meter) PNGARG((png_structp
2060png_ptr, png_infop info_ptr));
2061extern PNG_EXPORT(png_uint_32, png_get_x_pixels_per_meter) PNGARG((png_structp
2062png_ptr, png_infop info_ptr));
2063extern PNG_EXPORT(png_uint_32, png_get_y_pixels_per_meter) PNGARG((png_structp
2064png_ptr, png_infop info_ptr));
2065
2066/* Returns pixel aspect ratio, computed from pHYs chunk data. */
2067#ifdef PNG_FLOATING_POINT_SUPPORTED
2068extern PNG_EXPORT(float, png_get_pixel_aspect_ratio) PNGARG((png_structp
2069png_ptr, png_infop info_ptr));
2070#endif
2071
2072/* Returns image x, y offset in pixels or microns, from oFFs chunk data. */
2073extern PNG_EXPORT(png_int_32, png_get_x_offset_pixels) PNGARG((png_structp
2074png_ptr, png_infop info_ptr));
2075extern PNG_EXPORT(png_int_32, png_get_y_offset_pixels) PNGARG((png_structp
2076png_ptr, png_infop info_ptr));
2077extern PNG_EXPORT(png_int_32, png_get_x_offset_microns) PNGARG((png_structp
2078png_ptr, png_infop info_ptr));
2079extern PNG_EXPORT(png_int_32, png_get_y_offset_microns) PNGARG((png_structp
2080png_ptr, png_infop info_ptr));
2081
2082#endif /* PNG_EASY_ACCESS_SUPPORTED */
2083
2084/* Returns pointer to signature string read from PNG header */
2085extern PNG_EXPORT(png_bytep,png_get_signature) PNGARG((png_structp png_ptr,
2086png_infop info_ptr));
2087
2088#ifdef PNG_bKGD_SUPPORTED
2089extern PNG_EXPORT(png_uint_32,png_get_bKGD) PNGARG((png_structp png_ptr,
2090 png_infop info_ptr, png_color_16p *background));
2091#endif
2092
2093#ifdef PNG_bKGD_SUPPORTED
2094extern PNG_EXPORT(void,png_set_bKGD) PNGARG((png_structp png_ptr,
2095 png_infop info_ptr, png_color_16p background));
2096#endif
2097
2098#ifdef PNG_cHRM_SUPPORTED
2099#ifdef PNG_FLOATING_POINT_SUPPORTED
2100extern PNG_EXPORT(png_uint_32,png_get_cHRM) PNGARG((png_structp png_ptr,
2101 png_infop info_ptr, double *white_x, double *white_y, double *red_x,
2102 double *red_y, double *green_x, double *green_y, double *blue_x,
2103 double *blue_y));
2104#endif
2105#ifdef PNG_FIXED_POINT_SUPPORTED
2106extern PNG_EXPORT(png_uint_32,png_get_cHRM_fixed) PNGARG((png_structp png_ptr,
2107 png_infop info_ptr, png_fixed_point *int_white_x, png_fixed_point
2108 *int_white_y, png_fixed_point *int_red_x, png_fixed_point *int_red_y,
2109 png_fixed_point *int_green_x, png_fixed_point *int_green_y, png_fixed_point
2110 *int_blue_x, png_fixed_point *int_blue_y));
2111#endif
2112#endif
2113
2114#ifdef PNG_cHRM_SUPPORTED
2115#ifdef PNG_FLOATING_POINT_SUPPORTED
2116extern PNG_EXPORT(void,png_set_cHRM) PNGARG((png_structp png_ptr,
2117 png_infop info_ptr, double white_x, double white_y, double red_x,
2118 double red_y, double green_x, double green_y, double blue_x, double blue_y));
2119#endif
2120#ifdef PNG_FIXED_POINT_SUPPORTED
2121extern PNG_EXPORT(void,png_set_cHRM_fixed) PNGARG((png_structp png_ptr,
2122 png_infop info_ptr, png_fixed_point int_white_x, png_fixed_point int_white_y,
2123 png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
2124 int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
2125 png_fixed_point int_blue_y));
2126#endif
2127#endif
2128
2129#ifdef PNG_gAMA_SUPPORTED
2130#ifdef PNG_FLOATING_POINT_SUPPORTED
2131extern PNG_EXPORT(png_uint_32,png_get_gAMA) PNGARG((png_structp png_ptr,
2132 png_infop info_ptr, double *file_gamma));
2133#endif
2134extern PNG_EXPORT(png_uint_32,png_get_gAMA_fixed) PNGARG((png_structp png_ptr,
2135 png_infop info_ptr, png_fixed_point *int_file_gamma));
2136#endif
2137
2138#ifdef PNG_gAMA_SUPPORTED
2139#ifdef PNG_FLOATING_POINT_SUPPORTED
2140extern PNG_EXPORT(void,png_set_gAMA) PNGARG((png_structp png_ptr,
2141 png_infop info_ptr, double file_gamma));
2142#endif
2143extern PNG_EXPORT(void,png_set_gAMA_fixed) PNGARG((png_structp png_ptr,
2144 png_infop info_ptr, png_fixed_point int_file_gamma));
2145#endif
2146
2147#ifdef PNG_hIST_SUPPORTED
2148extern PNG_EXPORT(png_uint_32,png_get_hIST) PNGARG((png_structp png_ptr,
2149 png_infop info_ptr, png_uint_16p *hist));
2150#endif
2151
2152#ifdef PNG_hIST_SUPPORTED
2153extern PNG_EXPORT(void,png_set_hIST) PNGARG((png_structp png_ptr,
2154 png_infop info_ptr, png_uint_16p hist));
2155#endif
2156
2157extern PNG_EXPORT(png_uint_32,png_get_IHDR) PNGARG((png_structp png_ptr,
2158 png_infop info_ptr, png_uint_32 *width, png_uint_32 *height,
2159 int *bit_depth, int *color_type, int *interlace_method,
2160 int *compression_method, int *filter_method));
2161
2162extern PNG_EXPORT(void,png_set_IHDR) PNGARG((png_structp png_ptr,
2163 png_infop info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth,
2164 int color_type, int interlace_method, int compression_method,
2165 int filter_method));
2166
2167#ifdef PNG_oFFs_SUPPORTED
2168extern PNG_EXPORT(png_uint_32,png_get_oFFs) PNGARG((png_structp png_ptr,
2169 png_infop info_ptr, png_int_32 *offset_x, png_int_32 *offset_y,
2170 int *unit_type));
2171#endif
2172
2173#ifdef PNG_oFFs_SUPPORTED
2174extern PNG_EXPORT(void,png_set_oFFs) PNGARG((png_structp png_ptr,
2175 png_infop info_ptr, png_int_32 offset_x, png_int_32 offset_y,
2176 int unit_type));
2177#endif
2178
2179#ifdef PNG_pCAL_SUPPORTED
2180extern PNG_EXPORT(png_uint_32,png_get_pCAL) PNGARG((png_structp png_ptr,
2181 png_infop info_ptr, png_charp *purpose, png_int_32 *X0, png_int_32 *X1,
2182 int *type, int *nparams, png_charp *units, png_charpp *params));
2183#endif
2184
2185#ifdef PNG_pCAL_SUPPORTED
2186extern PNG_EXPORT(void,png_set_pCAL) PNGARG((png_structp png_ptr,
2187 png_infop info_ptr, png_charp purpose, png_int_32 X0, png_int_32 X1,
2188 int type, int nparams, png_charp units, png_charpp params));
2189#endif
2190
2191#ifdef PNG_pHYs_SUPPORTED
2192extern PNG_EXPORT(png_uint_32,png_get_pHYs) PNGARG((png_structp png_ptr,
2193 png_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type));
2194#endif
2195
2196#ifdef PNG_pHYs_SUPPORTED
2197extern PNG_EXPORT(void,png_set_pHYs) PNGARG((png_structp png_ptr,
2198 png_infop info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type));
2199#endif
2200
2201extern PNG_EXPORT(png_uint_32,png_get_PLTE) PNGARG((png_structp png_ptr,
2202 png_infop info_ptr, png_colorp *palette, int *num_palette));
2203
2204extern PNG_EXPORT(void,png_set_PLTE) PNGARG((png_structp png_ptr,
2205 png_infop info_ptr, png_colorp palette, int num_palette));
2206
2207#ifdef PNG_sBIT_SUPPORTED
2208extern PNG_EXPORT(png_uint_32,png_get_sBIT) PNGARG((png_structp png_ptr,
2209 png_infop info_ptr, png_color_8p *sig_bit));
2210#endif
2211
2212#ifdef PNG_sBIT_SUPPORTED
2213extern PNG_EXPORT(void,png_set_sBIT) PNGARG((png_structp png_ptr,
2214 png_infop info_ptr, png_color_8p sig_bit));
2215#endif
2216
2217#ifdef PNG_sRGB_SUPPORTED
2218extern PNG_EXPORT(png_uint_32,png_get_sRGB) PNGARG((png_structp png_ptr,
2219 png_infop info_ptr, int *intent));
2220#endif
2221
2222#ifdef PNG_sRGB_SUPPORTED
2223extern PNG_EXPORT(void,png_set_sRGB) PNGARG((png_structp png_ptr,
2224 png_infop info_ptr, int intent));
2225extern PNG_EXPORT(void,png_set_sRGB_gAMA_and_cHRM) PNGARG((png_structp png_ptr,
2226 png_infop info_ptr, int intent));
2227#endif
2228
2229#ifdef PNG_iCCP_SUPPORTED
2230extern PNG_EXPORT(png_uint_32,png_get_iCCP) PNGARG((png_structp png_ptr,
2231 png_infop info_ptr, png_charpp name, int *compression_type,
2232 png_charpp profile, png_uint_32 *proflen));
2233 /* Note to maintainer: profile should be png_bytepp */
2234#endif
2235
2236#ifdef PNG_iCCP_SUPPORTED
2237extern PNG_EXPORT(void,png_set_iCCP) PNGARG((png_structp png_ptr,
2238 png_infop info_ptr, png_charp name, int compression_type,
2239 png_charp profile, png_uint_32 proflen));
2240 /* Note to maintainer: profile should be png_bytep */
2241#endif
2242
2243#ifdef PNG_sPLT_SUPPORTED
2244extern PNG_EXPORT(png_uint_32,png_get_sPLT) PNGARG((png_structp png_ptr,
2245 png_infop info_ptr, png_sPLT_tpp entries));
2246#endif
2247
2248#ifdef PNG_sPLT_SUPPORTED
2249extern PNG_EXPORT(void,png_set_sPLT) PNGARG((png_structp png_ptr,
2250 png_infop info_ptr, png_sPLT_tp entries, int nentries));
2251#endif
2252
2253#ifdef PNG_TEXT_SUPPORTED
2254/* png_get_text also returns the number of text chunks in *num_text */
2255extern PNG_EXPORT(png_uint_32,png_get_text) PNGARG((png_structp png_ptr,
2256 png_infop info_ptr, png_textp *text_ptr, int *num_text));
2257#endif
2258
2259/* Note while png_set_text() will accept a structure whose text,
2260 * language, and translated keywords are NULL pointers, the structure
2261 * returned by png_get_text will always contain regular
2262 * zero-terminated C strings. They might be empty strings but
2263 * they will never be NULL pointers.
2264 */
2265
2266#ifdef PNG_TEXT_SUPPORTED
2267extern PNG_EXPORT(void,png_set_text) PNGARG((png_structp png_ptr,
2268 png_infop info_ptr, png_textp text_ptr, int num_text));
2269#endif
2270
2271#ifdef PNG_tIME_SUPPORTED
2272extern PNG_EXPORT(png_uint_32,png_get_tIME) PNGARG((png_structp png_ptr,
2273 png_infop info_ptr, png_timep *mod_time));
2274#endif
2275
2276#ifdef PNG_tIME_SUPPORTED
2277extern PNG_EXPORT(void,png_set_tIME) PNGARG((png_structp png_ptr,
2278 png_infop info_ptr, png_timep mod_time));
2279#endif
2280
2281#ifdef PNG_tRNS_SUPPORTED
2282extern PNG_EXPORT(png_uint_32,png_get_tRNS) PNGARG((png_structp png_ptr,
2283 png_infop info_ptr, png_bytep *trans_alpha, int *num_trans,
2284 png_color_16p *trans_color));
2285#endif
2286
2287#ifdef PNG_tRNS_SUPPORTED
2288extern PNG_EXPORT(void,png_set_tRNS) PNGARG((png_structp png_ptr,
2289 png_infop info_ptr, png_bytep trans_alpha, int num_trans,
2290 png_color_16p trans_color));
2291#endif
2292
2293#ifdef PNG_tRNS_SUPPORTED
2294#endif
2295
2296#ifdef PNG_sCAL_SUPPORTED
2297#ifdef PNG_FLOATING_POINT_SUPPORTED
2298extern PNG_EXPORT(png_uint_32,png_get_sCAL) PNGARG((png_structp png_ptr,
2299 png_infop info_ptr, int *unit, double *width, double *height));
2300#else
2301#ifdef PNG_FIXED_POINT_SUPPORTED
2302extern PNG_EXPORT(png_uint_32,png_get_sCAL_s) PNGARG((png_structp png_ptr,
2303 png_infop info_ptr, int *unit, png_charpp swidth, png_charpp sheight));
2304#endif
2305#endif
2306#endif /* PNG_sCAL_SUPPORTED */
2307
2308#ifdef PNG_sCAL_SUPPORTED
2309#ifdef PNG_FLOATING_POINT_SUPPORTED
2310extern PNG_EXPORT(void,png_set_sCAL) PNGARG((png_structp png_ptr,
2311 png_infop info_ptr, int unit, double width, double height));
2312#else
2313#ifdef PNG_FIXED_POINT_SUPPORTED
2314extern PNG_EXPORT(void,png_set_sCAL_s) PNGARG((png_structp png_ptr,
2315 png_infop info_ptr, int unit, png_charp swidth, png_charp sheight));
2316#endif
2317#endif
2318#endif /* PNG_sCAL_SUPPORTED || PNG_WRITE_sCAL_SUPPORTED */
2319
2320#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
2321/* Provide a list of chunks and how they are to be handled, if the built-in
2322 handling or default unknown chunk handling is not desired. Any chunks not
2323 listed will be handled in the default manner. The IHDR and IEND chunks
2324 must not be listed.
2325 keep = 0: follow default behaviour
2326 = 1: do not keep
2327 = 2: keep only if safe-to-copy
2328 = 3: keep even if unsafe-to-copy
2329*/
2330extern PNG_EXPORT(void, png_set_keep_unknown_chunks) PNGARG((png_structp
2331 png_ptr, int keep, png_bytep chunk_list, int num_chunks));
2332PNG_EXPORT(int,png_handle_as_unknown) PNGARG((png_structp png_ptr, png_bytep
2333 chunk_name));
2334#endif
2335#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
2336extern PNG_EXPORT(void, png_set_unknown_chunks) PNGARG((png_structp png_ptr,
2337 png_infop info_ptr, png_unknown_chunkp unknowns, int num_unknowns));
2338extern PNG_EXPORT(void, png_set_unknown_chunk_location)
2339 PNGARG((png_structp png_ptr, png_infop info_ptr, int chunk, int location));
2340extern PNG_EXPORT(png_uint_32,png_get_unknown_chunks) PNGARG((png_structp
2341 png_ptr, png_infop info_ptr, png_unknown_chunkpp entries));
2342#endif
2343
2344/* Png_free_data() will turn off the "valid" flag for anything it frees.
2345 * If you need to turn it off for a chunk that your application has freed,
2346 * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK);
2347 */
2348extern PNG_EXPORT(void, png_set_invalid) PNGARG((png_structp png_ptr,
2349 png_infop info_ptr, int mask));
2350
2351#ifdef PNG_INFO_IMAGE_SUPPORTED
2352/* The "params" pointer is currently not used and is for future expansion. */
2353extern PNG_EXPORT(void, png_read_png) PNGARG((png_structp png_ptr,
2354 png_infop info_ptr,
2355 int transforms,
2356 png_voidp params));
2357extern PNG_EXPORT(void, png_write_png) PNGARG((png_structp png_ptr,
2358 png_infop info_ptr,
2359 int transforms,
2360 png_voidp params));
2361#endif
2362
2363extern PNG_EXPORT(png_charp,png_get_copyright) PNGARG((png_structp png_ptr));
2364extern PNG_EXPORT(png_charp,png_get_header_ver) PNGARG((png_structp png_ptr));
2365extern PNG_EXPORT(png_charp,png_get_header_version) PNGARG((png_structp png_ptr));
2366extern PNG_EXPORT(png_charp,png_get_libpng_ver) PNGARG((png_structp png_ptr));
2367
2368#ifdef PNG_MNG_FEATURES_SUPPORTED
2369extern PNG_EXPORT(png_uint_32,png_permit_mng_features) PNGARG((png_structp
2370 png_ptr, png_uint_32 mng_features_permitted));
2371#endif
2372
2373/* For use in png_set_keep_unknown, added to version 1.2.6 */
2374#define PNG_HANDLE_CHUNK_AS_DEFAULT 0
2375#define PNG_HANDLE_CHUNK_NEVER 1
2376#define PNG_HANDLE_CHUNK_IF_SAFE 2
2377#define PNG_HANDLE_CHUNK_ALWAYS 3
2378
2379/* Strip the prepended error numbers ("#nnn ") from error and warning
2380 * messages before passing them to the error or warning handler.
2381 */
2382#ifdef PNG_ERROR_NUMBERS_SUPPORTED
2383extern PNG_EXPORT(void,png_set_strip_error_numbers) PNGARG((png_structp
2384 png_ptr, png_uint_32 strip_mode));
2385#endif
2386
2387/* Added in libpng-1.2.6 */
2388#ifdef PNG_SET_USER_LIMITS_SUPPORTED
2389extern PNG_EXPORT(void,png_set_user_limits) PNGARG((png_structp
2390 png_ptr, png_uint_32 user_width_max, png_uint_32 user_height_max));
2391extern PNG_EXPORT(png_uint_32,png_get_user_width_max) PNGARG((png_structp
2392 png_ptr));
2393extern PNG_EXPORT(png_uint_32,png_get_user_height_max) PNGARG((png_structp
2394 png_ptr));
2395/* Added in libpng-1.4.0 */
2396extern PNG_EXPORT(void,png_set_chunk_cache_max) PNGARG((png_structp
2397 png_ptr, png_uint_32 user_chunk_cache_max));
2398extern PNG_EXPORT(png_uint_32,png_get_chunk_cache_max)
2399 PNGARG((png_structp png_ptr));
2400#endif
2401
2402#if defined(PNG_INCH_CONVERSIONS) && defined(PNG_FLOATING_POINT_SUPPORTED)
2403PNG_EXPORT(png_uint_32,png_get_pixels_per_inch) PNGARG((png_structp png_ptr,
2404png_infop info_ptr));
2405
2406PNG_EXPORT(png_uint_32,png_get_x_pixels_per_inch) PNGARG((png_structp png_ptr,
2407png_infop info_ptr));
2408
2409PNG_EXPORT(png_uint_32,png_get_y_pixels_per_inch) PNGARG((png_structp png_ptr,
2410png_infop info_ptr));
2411
2412PNG_EXPORT(float,png_get_x_offset_inches) PNGARG((png_structp png_ptr,
2413png_infop info_ptr));
2414
2415PNG_EXPORT(float,png_get_y_offset_inches) PNGARG((png_structp png_ptr,
2416png_infop info_ptr));
2417
2418#ifdef PNG_pHYs_SUPPORTED
2419PNG_EXPORT(png_uint_32,png_get_pHYs_dpi) PNGARG((png_structp png_ptr,
2420png_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type));
2421#endif /* PNG_pHYs_SUPPORTED */
2422#endif /* PNG_INCH_CONVERSIONS && PNG_FLOATING_POINT_SUPPORTED */
2423
2424/* Added in libpng-1.4.0 */
2425#ifdef PNG_IO_STATE_SUPPORTED
2426extern PNG_EXPORT(png_uint_32,png_get_io_state) PNGARG((png_structp png_ptr));
2427
2428extern PNG_EXPORT(png_bytep,png_get_io_chunk_name)
2429 PNGARG((png_structp png_ptr));
2430
2431/* The flags returned by png_get_io_state() are the following: */
2432#define PNG_IO_NONE 0x0000 /* no I/O at this moment */
2433#define PNG_IO_READING 0x0001 /* currently reading */
2434#define PNG_IO_WRITING 0x0002 /* currently writing */
2435#define PNG_IO_SIGNATURE 0x0010 /* currently at the file signature */
2436#define PNG_IO_CHUNK_HDR 0x0020 /* currently at the chunk header */
2437#define PNG_IO_CHUNK_DATA 0x0040 /* currently at the chunk data */
2438#define PNG_IO_CHUNK_CRC 0x0080 /* currently at the chunk crc */
2439#define PNG_IO_MASK_OP 0x000f /* current operation: reading/writing */
2440#define PNG_IO_MASK_LOC 0x00f0 /* current location: sig/hdr/data/crc */
2441#endif /* ?PNG_IO_STATE_SUPPORTED */
2442
2443/* Maintainer: Put new public prototypes here ^, in libpng.3, and project
2444 * defs
2445 */
2446
2447#ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
2448/* With these routines we avoid an integer divide, which will be slower on
2449 * most machines. However, it does take more operations than the corresponding
2450 * divide method, so it may be slower on a few RISC systems. There are two
2451 * shifts (by 8 or 16 bits) and an addition, versus a single integer divide.
2452 *
2453 * Note that the rounding factors are NOT supposed to be the same! 128 and
2454 * 32768 are correct for the NODIV code; 127 and 32767 are correct for the
2455 * standard method.
2456 *
2457 * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
2458 */
2459
2460 /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */
2461
2462# define png_composite(composite, fg, alpha, bg) \
2463 { png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) * (png_uint_16)(alpha) \
2464 + (png_uint_16)(bg)*(png_uint_16)(255 - \
2465 (png_uint_16)(alpha)) + (png_uint_16)128); \
2466 (composite) = (png_byte)((temp + (temp >> 8)) >> 8); }
2467
2468# define png_composite_16(composite, fg, alpha, bg) \
2469 { png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) * (png_uint_32)(alpha) \
2470 + (png_uint_32)(bg)*(png_uint_32)(65535L - \
2471 (png_uint_32)(alpha)) + (png_uint_32)32768L); \
2472 (composite) = (png_uint_16)((temp + (temp >> 16)) >> 16); }
2473
2474#else /* Standard method using integer division */
2475
2476# define png_composite(composite, fg, alpha, bg) \
2477 (composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) + \
2478 (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \
2479 (png_uint_16)127) / 255)
2480
2481# define png_composite_16(composite, fg, alpha, bg) \
2482 (composite) = (png_uint_16)(((png_uint_32)(fg) * (png_uint_32)(alpha) + \
2483 (png_uint_32)(bg)*(png_uint_32)(65535L - (png_uint_32)(alpha)) + \
2484 (png_uint_32)32767) / (png_uint_32)65535L)
2485#endif /* PNG_READ_COMPOSITE_NODIV_SUPPORTED */
2486
2487#ifdef PNG_USE_READ_MACROS
2488/* Inline macros to do direct reads of bytes from the input buffer.
2489 * The png_get_int_32() routine assumes we are using two's complement
2490 * format for negative values, which is almost certainly true.
2491 */
2492/* We could make special-case BIG_ENDIAN macros that do direct reads here */
2493# define png_get_uint_32(buf) \
2494 (((png_uint_32)(*(buf)) << 24) + \
2495 ((png_uint_32)(*((buf) + 1)) << 16) + \
2496 ((png_uint_32)(*((buf) + 2)) << 8) + \
2497 ((png_uint_32)(*((buf) + 3))))
2498# define png_get_uint_16(buf) \
2499 (((png_uint_32)(*(buf)) << 8) + \
2500 ((png_uint_32)(*((buf) + 1))))
2501#ifdef PNG_GET_INT_32_SUPPORTED
2502# define png_get_int_32(buf) \
2503 (((png_int_32)(*(buf)) << 24) + \
2504 ((png_int_32)(*((buf) + 1)) << 16) + \
2505 ((png_int_32)(*((buf) + 2)) << 8) + \
2506 ((png_int_32)(*((buf) + 3))))
2507#endif
2508#else
2509extern PNG_EXPORT(png_uint_32,png_get_uint_32) PNGARG((png_bytep buf));
2510extern PNG_EXPORT(png_uint_16,png_get_uint_16) PNGARG((png_bytep buf));
2511#ifdef PNG_GET_INT_32_SUPPORTED
2512extern PNG_EXPORT(png_int_32,png_get_int_32) PNGARG((png_bytep buf));
2513#endif
2514#endif
2515extern PNG_EXPORT(png_uint_32,png_get_uint_31)
2516 PNGARG((png_structp png_ptr, png_bytep buf));
2517/* No png_get_int_16 -- may be added if there's a real need for it. */
2518
2519/* Place a 32-bit number into a buffer in PNG byte order (big-endian). */
2520extern PNG_EXPORT(void,png_save_uint_32)
2521 PNGARG((png_bytep buf, png_uint_32 i));
2522extern PNG_EXPORT(void,png_save_int_32)
2523 PNGARG((png_bytep buf, png_int_32 i));
2524
2525/* Place a 16-bit number into a buffer in PNG byte order.
2526 * The parameter is declared unsigned int, not png_uint_16,
2527 * just to avoid potential problems on pre-ANSI C compilers.
2528 */
2529extern PNG_EXPORT(void,png_save_uint_16)
2530 PNGARG((png_bytep buf, unsigned int i));
2531/* No png_save_int_16 -- may be added if there's a real need for it. */
2532
2533/* ************************************************************************* */
2534
2535/* Various modes of operation. Note that after an init, mode is set to
2536 * zero automatically when the structure is created.
2537 */
2538#define PNG_HAVE_IHDR 0x01
2539#define PNG_HAVE_PLTE 0x02
2540#define PNG_HAVE_IDAT 0x04
2541#define PNG_AFTER_IDAT 0x08 /* Have complete zlib datastream */
2542#define PNG_HAVE_IEND 0x10
2543#define PNG_HAVE_gAMA 0x20
2544#define PNG_HAVE_cHRM 0x40
2545
2546#ifdef __cplusplus
2547}
2548#endif
2549
2550#endif /* PNG_VERSION_INFO_ONLY */
2551/* Do not put anything past this line */
2552#endif /* PNG_H */
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