2 /* png.h - header file for PNG reference library
4 * libpng version 1.4.1 - February 25, 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.)
9 * This code is released under the libpng license (See LICENSE, below)
11 * Authors and maintainers:
12 * libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
13 * libpng versions 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger
14 * libpng versions 0.97, January 1998, through 1.4.1 - February 25, 2010: Glenn
15 * See also "Contributing Authors", below.
17 * Note about libpng version numbers:
19 * Due to various miscommunications, unforeseen code incompatibilities
20 * and occasional factors outside the authors' control, version numbering
21 * on the library has not always been consistent and straightforward.
22 * The following table summarizes matters since version 0.89c, which was
23 * the first widely used release:
25 * source png.h png.h shared-lib
26 * version string int version
27 * ------- ------ ----- ----------
28 * 0.89c "1.0 beta 3" 0.89 89 1.0.89
29 * 0.90 "1.0 beta 4" 0.90 90 0.90 [should have been 2.0.90]
30 * 0.95 "1.0 beta 5" 0.95 95 0.95 [should have been 2.0.95]
31 * 0.96 "1.0 beta 6" 0.96 96 0.96 [should have been 2.0.96]
32 * 0.97b "1.00.97 beta 7" 1.00.97 97 1.0.1 [should have been 2.0.97]
33 * 0.97c 0.97 97 2.0.97
36 * 0.99a-m 0.99 99 2.0.99
37 * 1.00 1.00 100 2.1.0 [100 should be 10000]
38 * 1.0.0 (from here on, the 100 2.1.0 [100 should be 10000]
39 * 1.0.1 png.h string is 10001 2.1.0
40 * 1.0.1a-e identical to the 10002 from here on, the shared library
41 * 1.0.2 source version) 10002 is 2.V where V is the source code
42 * 1.0.2a-b 10003 version, except as noted.
47 * 1.0.5 (+ 2 patches) 10005
49 * 1.0.5e-r 10100 (not source compatible)
50 * 1.0.5s-v 10006 (not binary compatible)
51 * 1.0.6 (+ 3 patches) 10006 (still binary incompatible)
52 * 1.0.6d-f 10007 (still binary incompatible)
54 * 1.0.6h 10007 10.6h (testing xy.z so-numbering)
56 * 1.0.6j 10007 2.1.0.6j (incompatible with 1.0.0)
57 * 1.0.7beta11-14 DLLNUM 10007 2.1.0.7beta11-14 (binary compatible)
58 * 1.0.7beta15-18 1 10007 2.1.0.7beta15-18 (binary compatible)
59 * 1.0.7rc1-2 1 10007 2.1.0.7rc1-2 (binary compatible)
60 * 1.0.7 1 10007 (still compatible)
61 * 1.0.8beta1-4 1 10008 2.1.0.8beta1-4
62 * 1.0.8rc1 1 10008 2.1.0.8rc1
63 * 1.0.8 1 10008 2.1.0.8
64 * 1.0.9beta1-6 1 10009 2.1.0.9beta1-6
65 * 1.0.9rc1 1 10009 2.1.0.9rc1
66 * 1.0.9beta7-10 1 10009 2.1.0.9beta7-10
67 * 1.0.9rc2 1 10009 2.1.0.9rc2
68 * 1.0.9 1 10009 2.1.0.9
69 * 1.0.10beta1 1 10010 2.1.0.10beta1
70 * 1.0.10rc1 1 10010 2.1.0.10rc1
71 * 1.0.10 1 10010 2.1.0.10
72 * 1.0.11beta1-3 1 10011 2.1.0.11beta1-3
73 * 1.0.11rc1 1 10011 2.1.0.11rc1
74 * 1.0.11 1 10011 2.1.0.11
75 * 1.0.12beta1-2 2 10012 2.1.0.12beta1-2
76 * 1.0.12rc1 2 10012 2.1.0.12rc1
77 * 1.0.12 2 10012 2.1.0.12
78 * 1.1.0a-f - 10100 2.1.1.0a-f (branch abandoned)
79 * 1.2.0beta1-2 2 10200 2.1.2.0beta1-2
80 * 1.2.0beta3-5 3 10200 3.1.2.0beta3-5
81 * 1.2.0rc1 3 10200 3.1.2.0rc1
82 * 1.2.0 3 10200 3.1.2.0
83 * 1.2.1beta1-4 3 10201 3.1.2.1beta1-4
84 * 1.2.1rc1-2 3 10201 3.1.2.1rc1-2
85 * 1.2.1 3 10201 3.1.2.1
86 * 1.2.2beta1-6 12 10202 12.so.0.1.2.2beta1-6
87 * 1.0.13beta1 10 10013 10.so.0.1.0.13beta1
88 * 1.0.13rc1 10 10013 10.so.0.1.0.13rc1
89 * 1.2.2rc1 12 10202 12.so.0.1.2.2rc1
90 * 1.0.13 10 10013 10.so.0.1.0.13
91 * 1.2.2 12 10202 12.so.0.1.2.2
92 * 1.2.3rc1-6 12 10203 12.so.0.1.2.3rc1-6
93 * 1.2.3 12 10203 12.so.0.1.2.3
94 * 1.2.4beta1-3 13 10204 12.so.0.1.2.4beta1-3
95 * 1.0.14rc1 13 10014 10.so.0.1.0.14rc1
96 * 1.2.4rc1 13 10204 12.so.0.1.2.4rc1
97 * 1.0.14 10 10014 10.so.0.1.0.14
98 * 1.2.4 13 10204 12.so.0.1.2.4
99 * 1.2.5beta1-2 13 10205 12.so.0.1.2.5beta1-2
100 * 1.0.15rc1-3 10 10015 10.so.0.1.0.15rc1-3
101 * 1.2.5rc1-3 13 10205 12.so.0.1.2.5rc1-3
102 * 1.0.15 10 10015 10.so.0.1.0.15
103 * 1.2.5 13 10205 12.so.0.1.2.5
104 * 1.2.6beta1-4 13 10206 12.so.0.1.2.6beta1-4
105 * 1.0.16 10 10016 10.so.0.1.0.16
106 * 1.2.6 13 10206 12.so.0.1.2.6
107 * 1.2.7beta1-2 13 10207 12.so.0.1.2.7beta1-2
108 * 1.0.17rc1 10 10017 12.so.0.1.0.17rc1
109 * 1.2.7rc1 13 10207 12.so.0.1.2.7rc1
110 * 1.0.17 10 10017 12.so.0.1.0.17
111 * 1.2.7 13 10207 12.so.0.1.2.7
112 * 1.2.8beta1-5 13 10208 12.so.0.1.2.8beta1-5
113 * 1.0.18rc1-5 10 10018 12.so.0.1.0.18rc1-5
114 * 1.2.8rc1-5 13 10208 12.so.0.1.2.8rc1-5
115 * 1.0.18 10 10018 12.so.0.1.0.18
116 * 1.2.8 13 10208 12.so.0.1.2.8
117 * 1.2.9beta1-3 13 10209 12.so.0.1.2.9beta1-3
118 * 1.2.9beta4-11 13 10209 12.so.0.9[.0]
119 * 1.2.9rc1 13 10209 12.so.0.9[.0]
120 * 1.2.9 13 10209 12.so.0.9[.0]
121 * 1.2.10beta1-7 13 10210 12.so.0.10[.0]
122 * 1.2.10rc1-2 13 10210 12.so.0.10[.0]
123 * 1.2.10 13 10210 12.so.0.10[.0]
124 * 1.4.0beta1-5 14 10400 14.so.0.0[.0]
125 * 1.2.11beta1-4 13 10211 12.so.0.11[.0]
126 * 1.4.0beta7-8 14 10400 14.so.0.0[.0]
127 * 1.2.11 13 10211 12.so.0.11[.0]
128 * 1.2.12 13 10212 12.so.0.12[.0]
129 * 1.4.0beta9-14 14 10400 14.so.0.0[.0]
130 * 1.2.13 13 10213 12.so.0.13[.0]
131 * 1.4.0beta15-36 14 10400 14.so.0.0[.0]
132 * 1.4.0beta37-87 14 10400 14.so.14.0[.0]
133 * 1.4.0rc01 14 10400 14.so.14.0[.0]
134 * 1.4.0beta88-109 14 10400 14.so.14.0[.0]
135 * 1.4.0rc02-08 14 10400 14.so.14.0[.0]
136 * 1.4.0 14 10400 14.so.14.0[.0]
137 * 1.4.1beta01-03 14 10401 14.so.14.1[.0]
138 * 1.4.1rc01 14 10401 14.so.14.1[.0]
139 * 1.4.1beta04-12 14 10401 14.so.14.1[.0]
140 * 1.4.1rc02-04 14 10401 14.so.14.1[.0]
141 * 1.4.1 14 10401 14.so.14.1[.0]
143 * Henceforth the source version will match the shared-library major
144 * and minor numbers; the shared-library major version number will be
145 * used for changes in backward compatibility, as it is intended. The
146 * PNG_LIBPNG_VER macro, which is not used within libpng but is available
147 * for applications, is an unsigned integer of the form xyyzz corresponding
148 * to the source version x.y.z (leading zeros in y and z). Beta versions
149 * were given the previous public release number plus a letter, until
150 * version 1.0.6j; from then on they were given the upcoming public
151 * release number plus "betaNN" or "rcN".
153 * Binary incompatibility exists only when applications make direct access
154 * to the info_ptr or png_ptr members through png.h, and the compiled
155 * application is loaded with a different version of the library.
157 * DLLNUM will change each time there are forward or backward changes
158 * in binary compatibility (e.g., when a new feature is added).
160 * See libpng.txt or libpng.3 for more information. The PNG specification
161 * is available as a W3C Recommendation and as an ISO Specification,
162 * <http://www.w3.org/TR/2003/REC-PNG-20031110/
166 * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
168 * If you modify libpng you may insert additional notices immediately following
171 * This code is released under the libpng license.
173 * libpng versions 1.2.6, August 15, 2004, through 1.4.1, February 25, 2010, are
174 * Copyright (c) 2004, 2006-2010 Glenn Randers-Pehrson, and are
175 * distributed according to the same disclaimer and license as libpng-1.2.5
176 * with the following individual added to the list of Contributing Authors:
180 * libpng versions 1.0.7, July 1, 2000, through 1.2.5, October 3, 2002, are
181 * Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are
182 * distributed according to the same disclaimer and license as libpng-1.0.6
183 * with the following individuals added to the list of Contributing Authors:
185 * Simon-Pierre Cadieux
189 * and with the following additions to the disclaimer:
191 * There is no warranty against interference with your enjoyment of the
192 * library or against infringement. There is no warranty that our
193 * efforts or the library will fulfill any of your particular purposes
194 * or needs. This library is provided with all faults, and the entire
195 * risk of satisfactory quality, performance, accuracy, and effort is with
198 * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
199 * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson, and are
200 * distributed according to the same disclaimer and license as libpng-0.96,
201 * with the following individuals added to the list of Contributing Authors:
204 * Glenn Randers-Pehrson
207 * libpng versions 0.89, June 1996, through 0.96, May 1997, are
208 * Copyright (c) 1996, 1997 Andreas Dilger
209 * Distributed according to the same disclaimer and license as libpng-0.88,
210 * with the following individuals added to the list of Contributing Authors:
219 * libpng versions 0.5, May 1995, through 0.88, January 1996, are
220 * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
222 * For the purposes of this copyright and license, "Contributing Authors"
223 * is defined as the following set of individuals:
231 * The PNG Reference Library is supplied "AS IS". The Contributing Authors
232 * and Group 42, Inc. disclaim all warranties, expressed or implied,
233 * including, without limitation, the warranties of merchantability and of
234 * fitness for any purpose. The Contributing Authors and Group 42, Inc.
235 * assume no liability for direct, indirect, incidental, special, exemplary,
236 * or consequential damages, which may result from the use of the PNG
237 * Reference Library, even if advised of the possibility of such damage.
239 * Permission is hereby granted to use, copy, modify, and distribute this
240 * source code, or portions hereof, for any purpose, without fee, subject
241 * to the following restrictions:
243 * 1. The origin of this source code must not be misrepresented.
245 * 2. Altered versions must be plainly marked as such and
246 * must not be misrepresented as being the original source.
248 * 3. This Copyright notice may not be removed or altered from
249 * any source or altered source distribution.
251 * The Contributing Authors and Group 42, Inc. specifically permit, without
252 * fee, and encourage the use of this source code as a component to
253 * supporting the PNG file format in commercial products. If you use this
254 * source code in a product, acknowledgment is not required but would be
259 * A "png_get_copyright" function is available, for convenient use in "about"
260 * boxes and the like:
262 * printf("%s",png_get_copyright(NULL));
264 * Also, the PNG logo (in PNG format, of course) is supplied in the
265 * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
269 * Libpng is OSI Certified Open Source Software. OSI Certified is a
270 * certification mark of the Open Source Initiative.
274 * The contributing authors would like to thank all those who helped
275 * with testing, bug fixes, and patience. This wouldn't have been
276 * possible without all of you.
278 * Thanks to Frank J. T. Wojcik for helping with the documentation.
282 * Y2K compliance in libpng:
283 * =========================
287 * Since the PNG Development group is an ad-hoc body, we can't make
288 * an official declaration.
290 * This is your unofficial assurance that libpng from version 0.71 and
291 * upward through 1.4.1 are Y2K compliant. It is my belief that earlier
292 * versions were also Y2K compliant.
294 * Libpng only has three year fields. One is a 2-byte unsigned integer
295 * that will hold years up to 65535. The other two hold the date in text
296 * format, and will hold years up to 9999.
299 * "png_uint_16 year" in png_time_struct.
302 * "png_charp time_buffer" in png_struct and
303 * "near_time_buffer", which is a local character string in png.c.
305 * There are seven time-related functions:
306 * png.c: png_convert_to_rfc_1123() in png.c
307 * (formerly png_convert_to_rfc_1152() in error)
308 * png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
309 * png_convert_from_time_t() in pngwrite.c
310 * png_get_tIME() in pngget.c
311 * png_handle_tIME() in pngrutil.c, called in pngread.c
312 * png_set_tIME() in pngset.c
313 * png_write_tIME() in pngwutil.c, called in pngwrite.c
315 * All handle dates properly in a Y2K environment. The
316 * png_convert_from_time_t() function calls gmtime() to convert from system
317 * clock time, which returns (year - 1900), which we properly convert to
318 * the full 4-digit year. There is a possibility that applications using
319 * libpng are not passing 4-digit years into the png_convert_to_rfc_1123()
320 * function, or that they are incorrectly passing only a 2-digit year
321 * instead of "year - 1900" into the png_convert_from_struct_tm() function,
322 * but this is not under our control. The libpng documentation has always
323 * stated that it works with 4-digit years, and the APIs have been
324 * documented as such.
326 * The tIME chunk itself is also Y2K compliant. It uses a 2-byte unsigned
327 * integer to hold the year, and can hold years as large as 65535.
329 * zlib, upon which libpng depends, is also Y2K compliant. It contains
330 * no date-related code.
332 * Glenn Randers-Pehrson
334 * PNG Development Group
340 /* This is not the place to learn how to use libpng. The file libpng.txt
341 * describes how to use libpng, and the file example.c summarizes it
342 * with some code on which to build. This file is useful for looking
343 * at the actual function definitions and structure components.
346 /* Version information for png.h - this should match the version in png.c */
347 #define PNG_LIBPNG_VER_STRING "1.4.1"
348 #define PNG_HEADER_VERSION_STRING \
349 " libpng version 1.4.1 - February 25, 2010\n"
351 #define PNG_LIBPNG_VER_SONUM 14
352 #define PNG_LIBPNG_VER_DLLNUM 14
354 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
355 #define PNG_LIBPNG_VER_MAJOR 1
356 #define PNG_LIBPNG_VER_MINOR 4
357 #define PNG_LIBPNG_VER_RELEASE 1
358 /* This should match the numeric part of the final component of
359 * PNG_LIBPNG_VER_STRING, omitting any leading zero:
362 #define PNG_LIBPNG_VER_BUILD 0
365 #define PNG_LIBPNG_BUILD_ALPHA 1
366 #define PNG_LIBPNG_BUILD_BETA 2
367 #define PNG_LIBPNG_BUILD_RC 3
368 #define PNG_LIBPNG_BUILD_STABLE 4
369 #define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7
371 /* Release-Specific Flags */
372 #define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with
373 PNG_LIBPNG_BUILD_STABLE only */
374 #define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with
375 PNG_LIBPNG_BUILD_SPECIAL */
376 #define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with
377 PNG_LIBPNG_BUILD_PRIVATE */
379 #define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_BETA
381 /* Careful here. At one time, Guy wanted to use 082, but that would be octal.
382 * We must not include leading zeros.
383 * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only
384 * version 1.0.0 was mis-numbered 100 instead of 10000). From
385 * version 1.0.1 it's xxyyzz, where x=major, y=minor, z=release
387 #define PNG_LIBPNG_VER 10401 /* 1.4.1 */
389 #ifndef PNG_VERSION_INFO_ONLY
390 /* Include the compression library's header */
394 /* Include all user configurable info, including optional assembler routines */
398 * Added at libpng-1.2.8
400 * Ref MSDN: Private as priority over Special
401 * VS_FF_PRIVATEBUILD File *was not* built using standard release
402 * procedures. If this value is given, the StringFileInfo block must
403 * contain a PrivateBuild string.
405 * VS_FF_SPECIALBUILD File *was* built by the original company using
406 * standard release procedures but is a variation of the standard
407 * file of the same version number. If this value is given, the
408 * StringFileInfo block must contain a SpecialBuild string.
411 #ifdef PNG_USER_PRIVATEBUILD
412 # define PNG_LIBPNG_BUILD_TYPE \
413 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE)
415 # ifdef PNG_LIBPNG_SPECIALBUILD
416 # define PNG_LIBPNG_BUILD_TYPE \
417 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL)
419 # define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE)
423 #ifndef PNG_VERSION_INFO_ONLY
425 /* Inhibit C++ name-mangling for libpng functions but not for system calls. */
428 #endif /* __cplusplus */
430 /* This file is arranged in several sections. The first section contains
431 * structure and type definitions. The second section contains the external
432 * library functions, while the third has the internal library functions,
433 * which applications aren't expected to use directly.
436 /* Variables declared in png.c - only it needs to define PNG_NO_EXTERN */
437 #if !defined(PNG_NO_EXTERN) || defined(PNG_ALWAYS_EXTERN)
438 /* Version information for C files, stored in png.c. This had better match
441 #define png_libpng_ver png_get_header_ver(NULL)
443 #endif /* PNG_NO_EXTERN */
445 /* Three color definitions. The order of the red, green, and blue, (and the
446 * exact size) is not important, although the size of the fields need to
447 * be png_byte or png_uint_16 (as defined below).
449 typedef struct png_color_struct
455 typedef png_color FAR * png_colorp;
456 typedef png_color FAR * FAR * png_colorpp;
458 typedef struct png_color_16_struct
460 png_byte index; /* used for palette files */
461 png_uint_16 red; /* for use in red green blue files */
464 png_uint_16 gray; /* for use in grayscale files */
466 typedef png_color_16 FAR * png_color_16p;
467 typedef png_color_16 FAR * FAR * png_color_16pp;
469 typedef struct png_color_8_struct
471 png_byte red; /* for use in red green blue files */
474 png_byte gray; /* for use in grayscale files */
475 png_byte alpha; /* for alpha channel files */
477 typedef png_color_8 FAR * png_color_8p;
478 typedef png_color_8 FAR * FAR * png_color_8pp;
481 * The following two structures are used for the in-core representation
484 typedef struct png_sPLT_entry_struct
490 png_uint_16 frequency;
492 typedef png_sPLT_entry FAR * png_sPLT_entryp;
493 typedef png_sPLT_entry FAR * FAR * png_sPLT_entrypp;
495 /* When the depth of the sPLT palette is 8 bits, the color and alpha samples
496 * occupy the LSB of their respective members, and the MSB of each member
497 * is zero-filled. The frequency member always occupies the full 16 bits.
500 typedef struct png_sPLT_struct
502 png_charp name; /* palette name */
503 png_byte depth; /* depth of palette samples */
504 png_sPLT_entryp entries; /* palette entries */
505 png_int_32 nentries; /* number of palette entries */
507 typedef png_sPLT_t FAR * png_sPLT_tp;
508 typedef png_sPLT_t FAR * FAR * png_sPLT_tpp;
510 #ifdef PNG_TEXT_SUPPORTED
511 /* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,
512 * and whether that contents is compressed or not. The "key" field
513 * points to a regular zero-terminated C string. The "text", "lang", and
514 * "lang_key" fields can be regular C strings, empty strings, or NULL pointers.
515 * However, the * structure returned by png_get_text() will always contain
516 * regular zero-terminated C strings (possibly empty), never NULL pointers,
517 * so they can be safely used in printf() and other string-handling functions.
519 typedef struct png_text_struct
521 int compression; /* compression value:
526 png_charp key; /* keyword, 1-79 character description of "text" */
527 png_charp text; /* comment, may be an empty string (ie "")
529 png_size_t text_length; /* length of the text string */
530 #ifdef PNG_iTXt_SUPPORTED
531 png_size_t itxt_length; /* length of the itxt string */
532 png_charp lang; /* language code, 0-79 characters
534 png_charp lang_key; /* keyword translated UTF-8 string, 0 or more
535 chars or a NULL pointer */
538 typedef png_text FAR * png_textp;
539 typedef png_text FAR * FAR * png_textpp;
542 /* Supported compression types for text in PNG files (tEXt, and zTXt).
543 * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */
544 #define PNG_TEXT_COMPRESSION_NONE_WR -3
545 #define PNG_TEXT_COMPRESSION_zTXt_WR -2
546 #define PNG_TEXT_COMPRESSION_NONE -1
547 #define PNG_TEXT_COMPRESSION_zTXt 0
548 #define PNG_ITXT_COMPRESSION_NONE 1
549 #define PNG_ITXT_COMPRESSION_zTXt 2
550 #define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */
552 /* png_time is a way to hold the time in an machine independent way.
553 * Two conversions are provided, both from time_t and struct tm. There
554 * is no portable way to convert to either of these structures, as far
555 * as I know. If you know of a portable way, send it to me. As a side
556 * note - PNG has always been Year 2000 compliant!
558 typedef struct png_time_struct
560 png_uint_16 year; /* full year, as in, 1995 */
561 png_byte month; /* month of year, 1 - 12 */
562 png_byte day; /* day of month, 1 - 31 */
563 png_byte hour; /* hour of day, 0 - 23 */
564 png_byte minute; /* minute of hour, 0 - 59 */
565 png_byte second; /* second of minute, 0 - 60 (for leap seconds) */
567 typedef png_time FAR * png_timep;
568 typedef png_time FAR * FAR * png_timepp;
570 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) || \
571 defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
572 /* png_unknown_chunk is a structure to hold queued chunks for which there is
573 * no specific support. The idea is that we can use this to queue
574 * up private chunks for output even though the library doesn't actually
575 * know about their semantics.
577 typedef struct png_unknown_chunk_t
583 /* libpng-using applications should NOT directly modify this byte. */
584 png_byte location; /* mode of operation at read time */
587 typedef png_unknown_chunk FAR * png_unknown_chunkp;
588 typedef png_unknown_chunk FAR * FAR * png_unknown_chunkpp;
591 /* png_info is a structure that holds the information in a PNG file so
592 * that the application can find out the characteristics of the image.
593 * If you are reading the file, this structure will tell you what is
594 * in the PNG file. If you are writing the file, fill in the information
595 * you want to put into the PNG file, then call png_write_info().
596 * The names chosen should be very close to the PNG specification, so
597 * consult that document for information about the meaning of each field.
599 * With libpng < 0.95, it was only possible to directly set and read the
600 * the values in the png_info_struct, which meant that the contents and
601 * order of the values had to remain fixed. With libpng 0.95 and later,
602 * however, there are now functions that abstract the contents of
603 * png_info_struct from the application, so this makes it easier to use
604 * libpng with dynamic libraries, and even makes it possible to use
605 * libraries that don't have all of the libpng ancillary chunk-handing
608 * In any case, the order of the parameters in png_info_struct should NOT
609 * be changed for as long as possible to keep compatibility with applications
610 * that use the old direct-access method with png_info_struct.
612 * The following members may have allocated storage attached that should be
613 * cleaned up before the structure is discarded: palette, trans, text,
614 * pcal_purpose, pcal_units, pcal_params, hist, iccp_name, iccp_profile,
615 * splt_palettes, scal_unit, row_pointers, and unknowns. By default, these
616 * are automatically freed when the info structure is deallocated, if they were
617 * allocated internally by libpng. This behavior can be changed by means
618 * of the png_data_freer() function.
620 * More allocation details: all the chunk-reading functions that
621 * change these members go through the corresponding png_set_*
622 * functions. A function to clear these members is available: see
623 * png_free_data(). The png_set_* functions do not depend on being
624 * able to point info structure members to any of the storage they are
625 * passed (they make their own copies), EXCEPT that the png_set_text
626 * functions use the same storage passed to them in the text_ptr or
627 * itxt_ptr structure argument, and the png_set_rows and png_set_unknowns
628 * functions do not make their own copies.
630 typedef struct png_info_struct
632 /* the following are necessary for every PNG file */
633 png_uint_32 width PNG_DEPSTRUCT; /* width of image in pixels (from IHDR) */
634 png_uint_32 height PNG_DEPSTRUCT; /* height of image in pixels (from IHDR) */
635 png_uint_32 valid PNG_DEPSTRUCT; /* valid chunk data (see PNG_INFO_
637 png_size_t rowbytes PNG_DEPSTRUCT; /* bytes needed to hold an untransformed
639 png_colorp palette PNG_DEPSTRUCT; /* array of color values
640 (valid & PNG_INFO_PLTE) */
641 png_uint_16 num_palette PNG_DEPSTRUCT; /* number of color entries in
643 png_uint_16 num_trans PNG_DEPSTRUCT; /* number of transparent palette
645 png_byte bit_depth PNG_DEPSTRUCT; /* 1, 2, 4, 8, or 16 bits/channel
647 png_byte color_type PNG_DEPSTRUCT; /* see PNG_COLOR_TYPE_ below
649 /* The following three should have been named *_method not *_type */
650 png_byte compression_type PNG_DEPSTRUCT; /* must be
651 PNG_COMPRESSION_TYPE_BASE (IHDR) */
652 png_byte filter_type PNG_DEPSTRUCT; /* must be PNG_FILTER_TYPE_BASE
654 png_byte interlace_type PNG_DEPSTRUCT; /* One of PNG_INTERLACE_NONE,
655 PNG_INTERLACE_ADAM7 */
657 /* The following is informational only on read, and not used on writes. */
658 png_byte channels PNG_DEPSTRUCT; /* number of data channels per
659 pixel (1, 2, 3, 4) */
660 png_byte pixel_depth PNG_DEPSTRUCT; /* number of bits per pixel */
661 png_byte spare_byte PNG_DEPSTRUCT; /* to align the data, and for
663 png_byte signature[8] PNG_DEPSTRUCT; /* magic bytes read by libpng
664 from start of file */
666 /* The rest of the data is optional. If you are reading, check the
667 * valid field to see if the information in these are valid. If you
668 * are writing, set the valid field to those chunks you want written,
669 * and initialize the appropriate fields below.
672 #if defined(PNG_gAMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
673 /* The gAMA chunk describes the gamma characteristics of the system
674 * on which the image was created, normally in the range [1.0, 2.5].
675 * Data is valid if (valid & PNG_INFO_gAMA) is non-zero.
677 float gamma PNG_DEPSTRUCT; /* gamma value of image,
678 if (valid & PNG_INFO_gAMA) */
681 #ifdef PNG_sRGB_SUPPORTED
683 /* Data valid if (valid & PNG_INFO_sRGB) non-zero. */
684 png_byte srgb_intent PNG_DEPSTRUCT; /* sRGB rendering intent
688 #ifdef PNG_TEXT_SUPPORTED
689 /* The tEXt, and zTXt chunks contain human-readable textual data in
690 * uncompressed, compressed, and optionally compressed forms, respectively.
691 * The data in "text" is an array of pointers to uncompressed,
692 * null-terminated C strings. Each chunk has a keyword that describes the
693 * textual data contained in that chunk. Keywords are not required to be
694 * unique, and the text string may be empty. Any number of text chunks may
697 int num_text PNG_DEPSTRUCT; /* number of comments read/to write */
698 int max_text PNG_DEPSTRUCT; /* current size of text array */
699 png_textp text PNG_DEPSTRUCT; /* array of comments read/to write */
700 #endif /* PNG_TEXT_SUPPORTED */
702 #ifdef PNG_tIME_SUPPORTED
703 /* The tIME chunk holds the last time the displayed image data was
704 * modified. See the png_time struct for the contents of this struct.
706 png_time mod_time PNG_DEPSTRUCT;
709 #ifdef PNG_sBIT_SUPPORTED
710 /* The sBIT chunk specifies the number of significant high-order bits
711 * in the pixel data. Values are in the range [1, bit_depth], and are
712 * only specified for the channels in the pixel data. The contents of
713 * the low-order bits is not specified. Data is valid if
714 * (valid & PNG_INFO_sBIT) is non-zero.
716 png_color_8 sig_bit PNG_DEPSTRUCT; /* significant bits in color channels */
719 #if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_EXPAND_SUPPORTED) || \
720 defined(PNG_READ_BACKGROUND_SUPPORTED)
721 /* The tRNS chunk supplies transparency data for paletted images and
722 * other image types that don't need a full alpha channel. There are
723 * "num_trans" transparency values for a paletted image, stored in the
724 * same order as the palette colors, starting from index 0. Values
725 * for the data are in the range [0, 255], ranging from fully transparent
726 * to fully opaque, respectively. For non-paletted images, there is a
727 * single color specified that should be treated as fully transparent.
728 * Data is valid if (valid & PNG_INFO_tRNS) is non-zero.
730 png_bytep trans_alpha PNG_DEPSTRUCT; /* alpha values for paletted
732 png_color_16 trans_color PNG_DEPSTRUCT; /* transparent color for
736 #if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
737 /* The bKGD chunk gives the suggested image background color if the
738 * display program does not have its own background color and the image
739 * is needs to composited onto a background before display. The colors
740 * in "background" are normally in the same color space/depth as the
741 * pixel data. Data is valid if (valid & PNG_INFO_bKGD) is non-zero.
743 png_color_16 background PNG_DEPSTRUCT;
746 #ifdef PNG_oFFs_SUPPORTED
747 /* The oFFs chunk gives the offset in "offset_unit_type" units rightwards
748 * and downwards from the top-left corner of the display, page, or other
749 * application-specific co-ordinate space. See the PNG_OFFSET_ defines
750 * below for the unit types. Valid if (valid & PNG_INFO_oFFs) non-zero.
752 png_int_32 x_offset PNG_DEPSTRUCT; /* x offset on page */
753 png_int_32 y_offset PNG_DEPSTRUCT; /* y offset on page */
754 png_byte offset_unit_type PNG_DEPSTRUCT; /* offset units type */
757 #ifdef PNG_pHYs_SUPPORTED
758 /* The pHYs chunk gives the physical pixel density of the image for
759 * display or printing in "phys_unit_type" units (see PNG_RESOLUTION_
760 * defines below). Data is valid if (valid & PNG_INFO_pHYs) is non-zero.
762 png_uint_32 x_pixels_per_unit PNG_DEPSTRUCT; /* horizontal pixel density */
763 png_uint_32 y_pixels_per_unit PNG_DEPSTRUCT; /* vertical pixel density */
764 png_byte phys_unit_type PNG_DEPSTRUCT; /* resolution type (see
765 PNG_RESOLUTION_ below) */
768 #ifdef PNG_hIST_SUPPORTED
769 /* The hIST chunk contains the relative frequency or importance of the
770 * various palette entries, so that a viewer can intelligently select a
771 * reduced-color palette, if required. Data is an array of "num_palette"
772 * values in the range [0,65535]. Data valid if (valid & PNG_INFO_hIST)
775 png_uint_16p hist PNG_DEPSTRUCT;
778 #ifdef PNG_cHRM_SUPPORTED
779 /* The cHRM chunk describes the CIE color characteristics of the monitor
780 * on which the PNG was created. This data allows the viewer to do gamut
781 * mapping of the input image to ensure that the viewer sees the same
782 * colors in the image as the creator. Values are in the range
783 * [0.0, 0.8]. Data valid if (valid & PNG_INFO_cHRM) non-zero.
785 #ifdef PNG_FLOATING_POINT_SUPPORTED
786 float x_white PNG_DEPSTRUCT;
787 float y_white PNG_DEPSTRUCT;
788 float x_red PNG_DEPSTRUCT;
789 float y_red PNG_DEPSTRUCT;
790 float x_green PNG_DEPSTRUCT;
791 float y_green PNG_DEPSTRUCT;
792 float x_blue PNG_DEPSTRUCT;
793 float y_blue PNG_DEPSTRUCT;
797 #ifdef PNG_pCAL_SUPPORTED
798 /* The pCAL chunk describes a transformation between the stored pixel
799 * values and original physical data values used to create the image.
800 * The integer range [0, 2^bit_depth - 1] maps to the floating-point
801 * range given by [pcal_X0, pcal_X1], and are further transformed by a
802 * (possibly non-linear) transformation function given by "pcal_type"
803 * and "pcal_params" into "pcal_units". Please see the PNG_EQUATION_
804 * defines below, and the PNG-Group's PNG extensions document for a
805 * complete description of the transformations and how they should be
806 * implemented, and for a description of the ASCII parameter strings.
807 * Data values are valid if (valid & PNG_INFO_pCAL) non-zero.
809 png_charp pcal_purpose PNG_DEPSTRUCT; /* pCAL chunk description string */
810 png_int_32 pcal_X0 PNG_DEPSTRUCT; /* minimum value */
811 png_int_32 pcal_X1 PNG_DEPSTRUCT; /* maximum value */
812 png_charp pcal_units PNG_DEPSTRUCT; /* Latin-1 string giving physical
814 png_charpp pcal_params PNG_DEPSTRUCT; /* ASCII strings containing
816 png_byte pcal_type PNG_DEPSTRUCT; /* equation type
817 (see PNG_EQUATION_ below) */
818 png_byte pcal_nparams PNG_DEPSTRUCT; /* number of parameters given
822 /* New members added in libpng-1.0.6 */
823 png_uint_32 free_me PNG_DEPSTRUCT; /* flags items libpng is
824 responsible for freeing */
826 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) || \
827 defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
828 /* Storage for unknown chunks that the library doesn't recognize. */
829 png_unknown_chunkp unknown_chunks PNG_DEPSTRUCT;
830 png_size_t unknown_chunks_num PNG_DEPSTRUCT;
833 #ifdef PNG_iCCP_SUPPORTED
834 /* iCCP chunk data. */
835 png_charp iccp_name PNG_DEPSTRUCT; /* profile name */
836 png_charp iccp_profile PNG_DEPSTRUCT; /* International Color Consortium
838 /* Note to maintainer: should be png_bytep */
839 png_uint_32 iccp_proflen PNG_DEPSTRUCT; /* ICC profile data length */
840 png_byte iccp_compression PNG_DEPSTRUCT; /* Always zero */
843 #ifdef PNG_sPLT_SUPPORTED
844 /* Data on sPLT chunks (there may be more than one). */
845 png_sPLT_tp splt_palettes PNG_DEPSTRUCT;
846 png_uint_32 splt_palettes_num PNG_DEPSTRUCT;
849 #ifdef PNG_sCAL_SUPPORTED
850 /* The sCAL chunk describes the actual physical dimensions of the
851 * subject matter of the graphic. The chunk contains a unit specification
852 * a byte value, and two ASCII strings representing floating-point
853 * values. The values are width and height corresponsing to one pixel
854 * in the image. This external representation is converted to double
855 * here. Data values are valid if (valid & PNG_INFO_sCAL) is non-zero.
857 png_byte scal_unit PNG_DEPSTRUCT; /* unit of physical scale */
858 #ifdef PNG_FLOATING_POINT_SUPPORTED
859 double scal_pixel_width PNG_DEPSTRUCT; /* width of one pixel */
860 double scal_pixel_height PNG_DEPSTRUCT; /* height of one pixel */
862 #ifdef PNG_FIXED_POINT_SUPPORTED
863 png_charp scal_s_width PNG_DEPSTRUCT; /* string containing height */
864 png_charp scal_s_height PNG_DEPSTRUCT; /* string containing width */
868 #ifdef PNG_INFO_IMAGE_SUPPORTED
869 /* Memory has been allocated if (valid & PNG_ALLOCATED_INFO_ROWS)
871 /* Data valid if (valid & PNG_INFO_IDAT) non-zero */
872 png_bytepp row_pointers PNG_DEPSTRUCT; /* the image bits */
875 #if defined(PNG_FIXED_POINT_SUPPORTED) && defined(PNG_gAMA_SUPPORTED)
876 png_fixed_point int_gamma PNG_DEPSTRUCT; /* gamma of image,
877 if (valid & PNG_INFO_gAMA) */
880 #if defined(PNG_cHRM_SUPPORTED) && defined(PNG_FIXED_POINT_SUPPORTED)
881 png_fixed_point int_x_white PNG_DEPSTRUCT;
882 png_fixed_point int_y_white PNG_DEPSTRUCT;
883 png_fixed_point int_x_red PNG_DEPSTRUCT;
884 png_fixed_point int_y_red PNG_DEPSTRUCT;
885 png_fixed_point int_x_green PNG_DEPSTRUCT;
886 png_fixed_point int_y_green PNG_DEPSTRUCT;
887 png_fixed_point int_x_blue PNG_DEPSTRUCT;
888 png_fixed_point int_y_blue PNG_DEPSTRUCT;
893 typedef png_info FAR * png_infop;
894 typedef png_info FAR * FAR * png_infopp;
896 /* Maximum positive integer used in PNG is (2^31)-1 */
897 #define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL)
898 #define PNG_UINT_32_MAX ((png_uint_32)(-1))
899 #define PNG_SIZE_MAX ((png_size_t)(-1))
901 /* These describe the color_type field in png_info. */
902 /* color type masks */
903 #define PNG_COLOR_MASK_PALETTE 1
904 #define PNG_COLOR_MASK_COLOR 2
905 #define PNG_COLOR_MASK_ALPHA 4
907 /* color types. Note that not all combinations are legal */
908 #define PNG_COLOR_TYPE_GRAY 0
909 #define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
910 #define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR)
911 #define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
912 #define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
914 #define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA
915 #define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA
917 /* This is for compression type. PNG 1.0-1.2 only define the single type. */
918 #define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */
919 #define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE
921 /* This is for filter type. PNG 1.0-1.2 only define the single type. */
922 #define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */
923 #define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */
924 #define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE
926 /* These are for the interlacing type. These values should NOT be changed. */
927 #define PNG_INTERLACE_NONE 0 /* Non-interlaced image */
928 #define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */
929 #define PNG_INTERLACE_LAST 2 /* Not a valid value */
931 /* These are for the oFFs chunk. These values should NOT be changed. */
932 #define PNG_OFFSET_PIXEL 0 /* Offset in pixels */
933 #define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */
934 #define PNG_OFFSET_LAST 2 /* Not a valid value */
936 /* These are for the pCAL chunk. These values should NOT be changed. */
937 #define PNG_EQUATION_LINEAR 0 /* Linear transformation */
938 #define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */
939 #define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */
940 #define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */
941 #define PNG_EQUATION_LAST 4 /* Not a valid value */
943 /* These are for the sCAL chunk. These values should NOT be changed. */
944 #define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */
945 #define PNG_SCALE_METER 1 /* meters per pixel */
946 #define PNG_SCALE_RADIAN 2 /* radians per pixel */
947 #define PNG_SCALE_LAST 3 /* Not a valid value */
949 /* These are for the pHYs chunk. These values should NOT be changed. */
950 #define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */
951 #define PNG_RESOLUTION_METER 1 /* pixels/meter */
952 #define PNG_RESOLUTION_LAST 2 /* Not a valid value */
954 /* These are for the sRGB chunk. These values should NOT be changed. */
955 #define PNG_sRGB_INTENT_PERCEPTUAL 0
956 #define PNG_sRGB_INTENT_RELATIVE 1
957 #define PNG_sRGB_INTENT_SATURATION 2
958 #define PNG_sRGB_INTENT_ABSOLUTE 3
959 #define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */
961 /* This is for text chunks */
962 #define PNG_KEYWORD_MAX_LENGTH 79
964 /* Maximum number of entries in PLTE/sPLT/tRNS arrays */
965 #define PNG_MAX_PALETTE_LENGTH 256
967 /* These determine if an ancillary chunk's data has been successfully read
968 * from the PNG header, or if the application has filled in the corresponding
969 * data in the info_struct to be written into the output file. The values
970 * of the PNG_INFO_<chunk> defines should NOT be changed.
972 #define PNG_INFO_gAMA 0x0001
973 #define PNG_INFO_sBIT 0x0002
974 #define PNG_INFO_cHRM 0x0004
975 #define PNG_INFO_PLTE 0x0008
976 #define PNG_INFO_tRNS 0x0010
977 #define PNG_INFO_bKGD 0x0020
978 #define PNG_INFO_hIST 0x0040
979 #define PNG_INFO_pHYs 0x0080
980 #define PNG_INFO_oFFs 0x0100
981 #define PNG_INFO_tIME 0x0200
982 #define PNG_INFO_pCAL 0x0400
983 #define PNG_INFO_sRGB 0x0800 /* GR-P, 0.96a */
984 #define PNG_INFO_iCCP 0x1000 /* ESR, 1.0.6 */
985 #define PNG_INFO_sPLT 0x2000 /* ESR, 1.0.6 */
986 #define PNG_INFO_sCAL 0x4000 /* ESR, 1.0.6 */
987 #define PNG_INFO_IDAT 0x8000L /* ESR, 1.0.6 */
989 /* This is used for the transformation routines, as some of them
990 * change these values for the row. It also should enable using
991 * the routines for other purposes.
993 typedef struct png_row_info_struct
995 png_uint_32 width; /* width of row */
996 png_size_t rowbytes; /* number of bytes in row */
997 png_byte color_type; /* color type of row */
998 png_byte bit_depth; /* bit depth of row */
999 png_byte channels; /* number of channels (1, 2, 3, or 4) */
1000 png_byte pixel_depth; /* bits per pixel (depth * channels) */
1003 typedef png_row_info FAR * png_row_infop;
1004 typedef png_row_info FAR * FAR * png_row_infopp;
1006 /* These are the function types for the I/O functions and for the functions
1007 * that allow the user to override the default I/O functions with his or her
1008 * own. The png_error_ptr type should match that of user-supplied warning
1009 * and error functions, while the png_rw_ptr type should match that of the
1010 * user read/write data functions.
1012 typedef struct png_struct_def png_struct;
1013 typedef png_struct FAR * png_structp;
1015 typedef void (PNGAPI *png_error_ptr) PNGARG((png_structp, png_const_charp));
1016 typedef void (PNGAPI *png_rw_ptr) PNGARG((png_structp, png_bytep, png_size_t));
1017 typedef void (PNGAPI *png_flush_ptr) PNGARG((png_structp));
1018 typedef void (PNGAPI *png_read_status_ptr) PNGARG((png_structp, png_uint_32,
1020 typedef void (PNGAPI *png_write_status_ptr) PNGARG((png_structp, png_uint_32,
1023 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1024 typedef void (PNGAPI *png_progressive_info_ptr) PNGARG((png_structp,
1026 typedef void (PNGAPI *png_progressive_end_ptr) PNGARG((png_structp, png_infop));
1027 typedef void (PNGAPI *png_progressive_row_ptr) PNGARG((png_structp, png_bytep,
1031 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
1032 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
1033 typedef void (PNGAPI *png_user_transform_ptr) PNGARG((png_structp,
1034 png_row_infop, png_bytep));
1037 #ifdef PNG_USER_CHUNKS_SUPPORTED
1038 typedef int (PNGAPI *png_user_chunk_ptr) PNGARG((png_structp,
1039 png_unknown_chunkp));
1041 #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
1042 typedef void (PNGAPI *png_unknown_chunk_ptr) PNGARG((png_structp));
1044 #ifdef PNG_SETJMP_SUPPORTED
1045 /* This must match the function definition in <setjmp.h>, and the
1046 * application must include this before png.h to obtain the definition
1049 typedef void (PNGAPI *png_longjmp_ptr) PNGARG((jmp_buf, int));
1052 /* Transform masks for the high-level interface */
1053 #define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */
1054 #define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */
1055 #define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */
1056 #define PNG_TRANSFORM_PACKING 0x0004 /* read and write */
1057 #define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */
1058 #define PNG_TRANSFORM_EXPAND 0x0010 /* read only */
1059 #define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */
1060 #define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */
1061 #define PNG_TRANSFORM_BGR 0x0080 /* read and write */
1062 #define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */
1063 #define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */
1064 #define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */
1065 #define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* write only */
1066 /* Added to libpng-1.2.34 */
1067 #define PNG_TRANSFORM_STRIP_FILLER_BEFORE PNG_TRANSFORM_STRIP_FILLER
1068 #define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */
1069 /* Added to libpng-1.4.0 */
1070 #define PNG_TRANSFORM_GRAY_TO_RGB 0x2000 /* read only */
1072 /* Flags for MNG supported features */
1073 #define PNG_FLAG_MNG_EMPTY_PLTE 0x01
1074 #define PNG_FLAG_MNG_FILTER_64 0x04
1075 #define PNG_ALL_MNG_FEATURES 0x05
1077 typedef png_voidp (*png_malloc_ptr) PNGARG((png_structp, png_alloc_size_t));
1078 typedef void (*png_free_ptr) PNGARG((png_structp, png_voidp));
1080 /* The structure that holds the information to read and write PNG files.
1081 * The only people who need to care about what is inside of this are the
1082 * people who will be modifying the library for their own special needs.
1083 * It should NOT be accessed directly by an application, except to store
1087 struct png_struct_def
1089 #ifdef PNG_SETJMP_SUPPORTED
1090 jmp_buf jmpbuf PNG_DEPSTRUCT; /* used in png_error */
1091 png_longjmp_ptr longjmp_fn PNG_DEPSTRUCT;/* setjmp non-local goto
1094 png_error_ptr error_fn PNG_DEPSTRUCT; /* function for printing
1095 errors and aborting */
1096 png_error_ptr warning_fn PNG_DEPSTRUCT; /* function for printing
1098 png_voidp error_ptr PNG_DEPSTRUCT; /* user supplied struct for
1100 png_rw_ptr write_data_fn PNG_DEPSTRUCT; /* function for writing
1102 png_rw_ptr read_data_fn PNG_DEPSTRUCT; /* function for reading
1104 png_voidp io_ptr PNG_DEPSTRUCT; /* ptr to application struct
1105 for I/O functions */
1107 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
1108 png_user_transform_ptr read_user_transform_fn PNG_DEPSTRUCT; /* user read
1112 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
1113 png_user_transform_ptr write_user_transform_fn PNG_DEPSTRUCT; /* user write
1117 /* These were added in libpng-1.0.2 */
1118 #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
1119 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
1120 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
1121 png_voidp user_transform_ptr PNG_DEPSTRUCT; /* user supplied struct
1122 for user transform */
1123 png_byte user_transform_depth PNG_DEPSTRUCT; /* bit depth of user
1124 transformed pixels */
1125 png_byte user_transform_channels PNG_DEPSTRUCT; /* channels in user
1126 transformed pixels */
1130 png_uint_32 mode PNG_DEPSTRUCT; /* tells us where we are in
1132 png_uint_32 flags PNG_DEPSTRUCT; /* flags indicating various
1134 png_uint_32 transformations PNG_DEPSTRUCT; /* which transformations
1137 z_stream zstream PNG_DEPSTRUCT; /* pointer to decompression
1138 structure (below) */
1139 png_bytep zbuf PNG_DEPSTRUCT; /* buffer for zlib */
1140 png_size_t zbuf_size PNG_DEPSTRUCT; /* size of zbuf */
1141 int zlib_level PNG_DEPSTRUCT; /* holds zlib compression level */
1142 int zlib_method PNG_DEPSTRUCT; /* holds zlib compression method */
1143 int zlib_window_bits PNG_DEPSTRUCT; /* holds zlib compression window
1145 int zlib_mem_level PNG_DEPSTRUCT; /* holds zlib compression memory
1147 int zlib_strategy PNG_DEPSTRUCT; /* holds zlib compression
1150 png_uint_32 width PNG_DEPSTRUCT; /* width of image in pixels */
1151 png_uint_32 height PNG_DEPSTRUCT; /* height of image in pixels */
1152 png_uint_32 num_rows PNG_DEPSTRUCT; /* number of rows in current pass */
1153 png_uint_32 usr_width PNG_DEPSTRUCT; /* width of row at start of write */
1154 png_size_t rowbytes PNG_DEPSTRUCT; /* size of row in bytes */
1155 #if 0 /* Replaced with the following in libpng-1.4.1 */
1156 png_size_t irowbytes PNG_DEPSTRUCT;
1158 /* Added in libpng-1.4.1 */
1159 #ifdef PNG_USER_LIMITS_SUPPORTED
1160 /* Total memory that a zTXt, sPLT, iTXt, iCCP, or unknown chunk
1161 * can occupy when decompressed. 0 means unlimited.
1162 * We will change the typedef from png_size_t to png_alloc_size_t
1165 png_alloc_size_t user_chunk_malloc_max PNG_DEPSTRUCT;
1167 png_uint_32 iwidth PNG_DEPSTRUCT; /* width of current interlaced
1169 png_uint_32 row_number PNG_DEPSTRUCT; /* current row in interlace pass */
1170 png_bytep prev_row PNG_DEPSTRUCT; /* buffer to save previous
1172 png_bytep row_buf PNG_DEPSTRUCT; /* buffer to save current
1174 png_bytep sub_row PNG_DEPSTRUCT; /* buffer to save "sub" row
1176 png_bytep up_row PNG_DEPSTRUCT; /* buffer to save "up" row
1178 png_bytep avg_row PNG_DEPSTRUCT; /* buffer to save "avg" row
1180 png_bytep paeth_row PNG_DEPSTRUCT; /* buffer to save "Paeth" row
1182 png_row_info row_info PNG_DEPSTRUCT; /* used for transformation
1185 png_uint_32 idat_size PNG_DEPSTRUCT; /* current IDAT size for read */
1186 png_uint_32 crc PNG_DEPSTRUCT; /* current chunk CRC value */
1187 png_colorp palette PNG_DEPSTRUCT; /* palette from the input file */
1188 png_uint_16 num_palette PNG_DEPSTRUCT; /* number of color entries in
1190 png_uint_16 num_trans PNG_DEPSTRUCT; /* number of transparency values */
1191 png_byte chunk_name[5] PNG_DEPSTRUCT; /* null-terminated name of current
1193 png_byte compression PNG_DEPSTRUCT; /* file compression type
1195 png_byte filter PNG_DEPSTRUCT; /* file filter type (always 0) */
1196 png_byte interlaced PNG_DEPSTRUCT; /* PNG_INTERLACE_NONE,
1197 PNG_INTERLACE_ADAM7 */
1198 png_byte pass PNG_DEPSTRUCT; /* current interlace pass (0 - 6) */
1199 png_byte do_filter PNG_DEPSTRUCT; /* row filter flags (see
1200 PNG_FILTER_ below ) */
1201 png_byte color_type PNG_DEPSTRUCT; /* color type of file */
1202 png_byte bit_depth PNG_DEPSTRUCT; /* bit depth of file */
1203 png_byte usr_bit_depth PNG_DEPSTRUCT; /* bit depth of users row */
1204 png_byte pixel_depth PNG_DEPSTRUCT; /* number of bits per pixel */
1205 png_byte channels PNG_DEPSTRUCT; /* number of channels in file */
1206 png_byte usr_channels PNG_DEPSTRUCT; /* channels at start of write */
1207 png_byte sig_bytes PNG_DEPSTRUCT; /* magic bytes read/written from
1210 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
1211 png_uint_16 filler PNG_DEPSTRUCT; /* filler bytes for pixel
1215 #ifdef PNG_bKGD_SUPPORTED
1216 png_byte background_gamma_type PNG_DEPSTRUCT;
1217 # ifdef PNG_FLOATING_POINT_SUPPORTED
1218 float background_gamma PNG_DEPSTRUCT;
1220 png_color_16 background PNG_DEPSTRUCT; /* background color in
1221 screen gamma space */
1222 #ifdef PNG_READ_GAMMA_SUPPORTED
1223 png_color_16 background_1 PNG_DEPSTRUCT; /* background normalized
1226 #endif /* PNG_bKGD_SUPPORTED */
1228 #ifdef PNG_WRITE_FLUSH_SUPPORTED
1229 png_flush_ptr output_flush_fn PNG_DEPSTRUCT; /* Function for flushing
1231 png_uint_32 flush_dist PNG_DEPSTRUCT; /* how many rows apart to flush,
1233 png_uint_32 flush_rows PNG_DEPSTRUCT; /* number of rows written since
1237 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1238 int gamma_shift PNG_DEPSTRUCT; /* number of "insignificant" bits
1240 #ifdef PNG_FLOATING_POINT_SUPPORTED
1241 float gamma PNG_DEPSTRUCT; /* file gamma value */
1242 float screen_gamma PNG_DEPSTRUCT; /* screen gamma value
1243 (display_exponent) */
1247 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1248 png_bytep gamma_table PNG_DEPSTRUCT; /* gamma table for 8-bit
1250 png_bytep gamma_from_1 PNG_DEPSTRUCT; /* converts from 1.0 to screen */
1251 png_bytep gamma_to_1 PNG_DEPSTRUCT; /* converts from file to 1.0 */
1252 png_uint_16pp gamma_16_table PNG_DEPSTRUCT; /* gamma table for 16-bit
1254 png_uint_16pp gamma_16_from_1 PNG_DEPSTRUCT; /* converts from 1.0 to
1256 png_uint_16pp gamma_16_to_1 PNG_DEPSTRUCT; /* converts from file to 1.0 */
1259 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_sBIT_SUPPORTED)
1260 png_color_8 sig_bit PNG_DEPSTRUCT; /* significant bits in each
1261 available channel */
1264 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
1265 png_color_8 shift PNG_DEPSTRUCT; /* shift for significant bit
1269 #if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \
1270 || defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1271 png_bytep trans_alpha PNG_DEPSTRUCT; /* alpha values for
1273 png_color_16 trans_color PNG_DEPSTRUCT; /* transparent color for
1274 non-paletted files */
1277 png_read_status_ptr read_row_fn PNG_DEPSTRUCT; /* called after each
1279 png_write_status_ptr write_row_fn PNG_DEPSTRUCT; /* called after each
1281 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1282 png_progressive_info_ptr info_fn PNG_DEPSTRUCT; /* called after header
1284 png_progressive_row_ptr row_fn PNG_DEPSTRUCT; /* called after each
1285 prog. row is decoded */
1286 png_progressive_end_ptr end_fn PNG_DEPSTRUCT; /* called after image
1288 png_bytep save_buffer_ptr PNG_DEPSTRUCT; /* current location in
1290 png_bytep save_buffer PNG_DEPSTRUCT; /* buffer for previously
1292 png_bytep current_buffer_ptr PNG_DEPSTRUCT; /* current location in
1294 png_bytep current_buffer PNG_DEPSTRUCT; /* buffer for recently
1296 png_uint_32 push_length PNG_DEPSTRUCT; /* size of current input
1298 png_uint_32 skip_length PNG_DEPSTRUCT; /* bytes to skip in
1300 png_size_t save_buffer_size PNG_DEPSTRUCT; /* amount of data now
1302 png_size_t save_buffer_max PNG_DEPSTRUCT; /* total size of
1304 png_size_t buffer_size PNG_DEPSTRUCT; /* total amount of
1305 available input data */
1306 png_size_t current_buffer_size PNG_DEPSTRUCT; /* amount of data now
1307 in current_buffer */
1308 int process_mode PNG_DEPSTRUCT; /* what push library
1309 is currently doing */
1310 int cur_palette PNG_DEPSTRUCT; /* current push library
1313 # ifdef PNG_TEXT_SUPPORTED
1314 png_size_t current_text_size PNG_DEPSTRUCT; /* current size of
1316 png_size_t current_text_left PNG_DEPSTRUCT; /* how much text left
1318 png_charp current_text PNG_DEPSTRUCT; /* current text chunk
1320 png_charp current_text_ptr PNG_DEPSTRUCT; /* current location
1322 # endif /* PNG_PROGRESSIVE_READ_SUPPORTED && PNG_TEXT_SUPPORTED */
1324 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
1326 #if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
1327 /* For the Borland special 64K segment handler */
1328 png_bytepp offset_table_ptr PNG_DEPSTRUCT;
1329 png_bytep offset_table PNG_DEPSTRUCT;
1330 png_uint_16 offset_table_number PNG_DEPSTRUCT;
1331 png_uint_16 offset_table_count PNG_DEPSTRUCT;
1332 png_uint_16 offset_table_count_free PNG_DEPSTRUCT;
1335 #ifdef PNG_READ_DITHER_SUPPORTED
1336 png_bytep palette_lookup PNG_DEPSTRUCT; /* lookup table for dithering */
1337 png_bytep dither_index PNG_DEPSTRUCT; /* index translation for palette
1341 #if defined(PNG_READ_DITHER_SUPPORTED) || defined(PNG_hIST_SUPPORTED)
1342 png_uint_16p hist PNG_DEPSTRUCT; /* histogram */
1345 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
1346 png_byte heuristic_method PNG_DEPSTRUCT; /* heuristic for row
1348 png_byte num_prev_filters PNG_DEPSTRUCT; /* number of weights
1349 for previous rows */
1350 png_bytep prev_filters PNG_DEPSTRUCT; /* filter type(s) of
1352 png_uint_16p filter_weights PNG_DEPSTRUCT; /* weight(s) for previous
1354 png_uint_16p inv_filter_weights PNG_DEPSTRUCT; /* 1/weight(s) for
1356 png_uint_16p filter_costs PNG_DEPSTRUCT; /* relative filter
1358 png_uint_16p inv_filter_costs PNG_DEPSTRUCT; /* 1/relative filter
1362 #ifdef PNG_TIME_RFC1123_SUPPORTED
1363 png_charp time_buffer PNG_DEPSTRUCT; /* String to hold RFC 1123 time text */
1366 /* New members added in libpng-1.0.6 */
1368 png_uint_32 free_me PNG_DEPSTRUCT; /* flags items libpng is
1369 responsible for freeing */
1371 #ifdef PNG_USER_CHUNKS_SUPPORTED
1372 png_voidp user_chunk_ptr PNG_DEPSTRUCT;
1373 png_user_chunk_ptr read_user_chunk_fn PNG_DEPSTRUCT; /* user read
1377 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
1378 int num_chunk_list PNG_DEPSTRUCT;
1379 png_bytep chunk_list PNG_DEPSTRUCT;
1382 /* New members added in libpng-1.0.3 */
1383 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1384 png_byte rgb_to_gray_status PNG_DEPSTRUCT;
1385 /* These were changed from png_byte in libpng-1.0.6 */
1386 png_uint_16 rgb_to_gray_red_coeff PNG_DEPSTRUCT;
1387 png_uint_16 rgb_to_gray_green_coeff PNG_DEPSTRUCT;
1388 png_uint_16 rgb_to_gray_blue_coeff PNG_DEPSTRUCT;
1391 /* New member added in libpng-1.0.4 (renamed in 1.0.9) */
1392 #if defined(PNG_MNG_FEATURES_SUPPORTED) || \
1393 defined(PNG_READ_EMPTY_PLTE_SUPPORTED) || \
1394 defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
1395 /* Changed from png_byte to png_uint_32 at version 1.2.0 */
1396 png_uint_32 mng_features_permitted PNG_DEPSTRUCT;
1399 /* New member added in libpng-1.0.7 */
1400 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1401 png_fixed_point int_gamma PNG_DEPSTRUCT;
1404 /* New member added in libpng-1.0.9, ifdef'ed out in 1.0.12, enabled in 1.2.0 */
1405 #ifdef PNG_MNG_FEATURES_SUPPORTED
1406 png_byte filter_type PNG_DEPSTRUCT;
1409 /* New members added in libpng-1.2.0 */
1411 /* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */
1412 #ifdef PNG_USER_MEM_SUPPORTED
1413 png_voidp mem_ptr PNG_DEPSTRUCT; /* user supplied struct for
1415 png_malloc_ptr malloc_fn PNG_DEPSTRUCT; /* function for
1416 allocating memory */
1417 png_free_ptr free_fn PNG_DEPSTRUCT; /* function for
1421 /* New member added in libpng-1.0.13 and 1.2.0 */
1422 png_bytep big_row_buf PNG_DEPSTRUCT; /* buffer to save current
1425 #ifdef PNG_READ_DITHER_SUPPORTED
1426 /* The following three members were added at version 1.0.14 and 1.2.4 */
1427 png_bytep dither_sort PNG_DEPSTRUCT; /* working sort array */
1428 png_bytep index_to_palette PNG_DEPSTRUCT; /* where the original
1431 png_bytep palette_to_index PNG_DEPSTRUCT; /* which original index
1436 /* New members added in libpng-1.0.16 and 1.2.6 */
1437 png_byte compression_type PNG_DEPSTRUCT;
1439 #ifdef PNG_USER_LIMITS_SUPPORTED
1440 png_uint_32 user_width_max PNG_DEPSTRUCT;
1441 png_uint_32 user_height_max PNG_DEPSTRUCT;
1442 /* Added in libpng-1.4.0: Total number of sPLT, text, and unknown
1443 * chunks that can be stored (0 means unlimited).
1445 png_uint_32 user_chunk_cache_max PNG_DEPSTRUCT;
1448 /* New member added in libpng-1.0.25 and 1.2.17 */
1449 #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
1450 /* Storage for unknown chunk that the library doesn't recognize. */
1451 png_unknown_chunk unknown_chunk PNG_DEPSTRUCT;
1454 /* New members added in libpng-1.2.26 */
1455 png_uint_32 old_big_row_buf_size PNG_DEPSTRUCT;
1456 png_uint_32 old_prev_row_size PNG_DEPSTRUCT;
1458 /* New member added in libpng-1.2.30 */
1459 png_charp chunkdata PNG_DEPSTRUCT; /* buffer for reading chunk data */
1461 #ifdef PNG_IO_STATE_SUPPORTED
1462 /* New member added in libpng-1.4.0 */
1463 png_uint_32 io_state PNG_DEPSTRUCT;
1468 /* This triggers a compiler error in png.c, if png.c and png.h
1469 * do not agree upon the version number.
1471 typedef png_structp version_1_4_1;
1473 typedef png_struct FAR * FAR * png_structpp;
1475 /* Here are the function definitions most commonly used. This is not
1476 * the place to find out how to use libpng. See libpng.txt for the
1477 * full explanation, see example.c for the summary. This just provides
1478 * a simple one line description of the use of each function.
1481 /* Returns the version number of the library */
1482 extern PNG_EXPORT(png_uint_32,png_access_version_number) PNGARG((void));
1484 /* Tell lib we have already handled the first <num_bytes> magic bytes.
1485 * Handling more than 8 bytes from the beginning of the file is an error.
1487 extern PNG_EXPORT(void,png_set_sig_bytes) PNGARG((png_structp png_ptr,
1490 /* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
1491 * PNG file. Returns zero if the supplied bytes match the 8-byte PNG
1492 * signature, and non-zero otherwise. Having num_to_check == 0 or
1493 * start > 7 will always fail (ie return non-zero).
1495 extern PNG_EXPORT(int,png_sig_cmp) PNGARG((png_bytep sig, png_size_t start,
1496 png_size_t num_to_check));
1498 /* Allocate and initialize png_ptr struct for reading, and any other memory. */
1499 extern PNG_EXPORT(png_structp,png_create_read_struct)
1500 PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1501 png_error_ptr error_fn, png_error_ptr warn_fn)) PNG_ALLOCATED;
1503 /* Allocate and initialize png_ptr struct for writing, and any other memory */
1504 extern PNG_EXPORT(png_structp,png_create_write_struct)
1505 PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1506 png_error_ptr error_fn, png_error_ptr warn_fn)) PNG_ALLOCATED;
1508 extern PNG_EXPORT(png_size_t,png_get_compression_buffer_size)
1509 PNGARG((png_structp png_ptr));
1511 extern PNG_EXPORT(void,png_set_compression_buffer_size)
1512 PNGARG((png_structp png_ptr, png_size_t size));
1514 /* Moved from pngconf.h in 1.4.0 and modified to ensure setjmp/longjmp
1517 #ifdef PNG_SETJMP_SUPPORTED
1518 /* This function returns the jmp_buf built in to *png_ptr. It must be
1519 * supplied with an appropriate 'longjmp' function to use on that jmp_buf
1520 * unless the default error function is overridden in which case NULL is
1521 * acceptable. The size of the jmp_buf is checked against the actual size
1522 * allocated by the library - the call will return NULL on a mismatch
1523 * indicating an ABI mismatch.
1525 extern PNG_EXPORT(jmp_buf*, png_set_longjmp_fn)
1526 PNGARG((png_structp png_ptr, png_longjmp_ptr longjmp_fn, size_t
1528 # define png_jmpbuf(png_ptr) \
1529 (*png_set_longjmp_fn((png_ptr), longjmp, sizeof (jmp_buf)))
1531 # define png_jmpbuf(png_ptr) \
1532 (LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP)
1535 /* Reset the compression stream */
1536 extern PNG_EXPORT(int,png_reset_zstream) PNGARG((png_structp png_ptr));
1538 /* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */
1539 #ifdef PNG_USER_MEM_SUPPORTED
1540 extern PNG_EXPORT(png_structp,png_create_read_struct_2)
1541 PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1542 png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
1543 png_malloc_ptr malloc_fn, png_free_ptr free_fn)) PNG_ALLOCATED;
1544 extern PNG_EXPORT(png_structp,png_create_write_struct_2)
1545 PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1546 png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
1547 png_malloc_ptr malloc_fn, png_free_ptr free_fn)) PNG_ALLOCATED;
1550 /* Write the PNG file signature. */
1551 extern PNG_EXPORT(void,png_write_sig) PNGARG((png_structp png_ptr));
1553 /* Write a PNG chunk - size, type, (optional) data, CRC. */
1554 extern PNG_EXPORT(void,png_write_chunk) PNGARG((png_structp png_ptr,
1555 png_bytep chunk_name, png_bytep data, png_size_t length));
1557 /* Write the start of a PNG chunk - length and chunk name. */
1558 extern PNG_EXPORT(void,png_write_chunk_start) PNGARG((png_structp png_ptr,
1559 png_bytep chunk_name, png_uint_32 length));
1561 /* Write the data of a PNG chunk started with png_write_chunk_start(). */
1562 extern PNG_EXPORT(void,png_write_chunk_data) PNGARG((png_structp png_ptr,
1563 png_bytep data, png_size_t length));
1565 /* Finish a chunk started with png_write_chunk_start() (includes CRC). */
1566 extern PNG_EXPORT(void,png_write_chunk_end) PNGARG((png_structp png_ptr));
1568 /* Allocate and initialize the info structure */
1569 extern PNG_EXPORT(png_infop,png_create_info_struct)
1570 PNGARG((png_structp png_ptr)) PNG_ALLOCATED;
1572 extern PNG_EXPORT(void,png_info_init_3) PNGARG((png_infopp info_ptr,
1573 png_size_t png_info_struct_size));
1575 /* Writes all the PNG information before the image. */
1576 extern PNG_EXPORT(void,png_write_info_before_PLTE) PNGARG((png_structp png_ptr,
1577 png_infop info_ptr));
1578 extern PNG_EXPORT(void,png_write_info) PNGARG((png_structp png_ptr,
1579 png_infop info_ptr));
1581 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1582 /* Read the information before the actual image data. */
1583 extern PNG_EXPORT(void,png_read_info) PNGARG((png_structp png_ptr,
1584 png_infop info_ptr));
1587 #ifdef PNG_TIME_RFC1123_SUPPORTED
1588 extern PNG_EXPORT(png_charp,png_convert_to_rfc1123)
1589 PNGARG((png_structp png_ptr, png_timep ptime));
1592 #ifdef PNG_CONVERT_tIME_SUPPORTED
1593 /* Convert from a struct tm to png_time */
1594 extern PNG_EXPORT(void,png_convert_from_struct_tm) PNGARG((png_timep ptime,
1595 struct tm FAR * ttime));
1597 /* Convert from time_t to png_time. Uses gmtime() */
1598 extern PNG_EXPORT(void,png_convert_from_time_t) PNGARG((png_timep ptime,
1600 #endif /* PNG_CONVERT_tIME_SUPPORTED */
1602 #ifdef PNG_READ_EXPAND_SUPPORTED
1603 /* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
1604 extern PNG_EXPORT(void,png_set_expand) PNGARG((png_structp png_ptr));
1605 extern PNG_EXPORT(void,png_set_expand_gray_1_2_4_to_8) PNGARG((png_structp
1607 extern PNG_EXPORT(void,png_set_palette_to_rgb) PNGARG((png_structp png_ptr));
1608 extern PNG_EXPORT(void,png_set_tRNS_to_alpha) PNGARG((png_structp png_ptr));
1611 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
1612 /* Use blue, green, red order for pixels. */
1613 extern PNG_EXPORT(void,png_set_bgr) PNGARG((png_structp png_ptr));
1616 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
1617 /* Expand the grayscale to 24-bit RGB if necessary. */
1618 extern PNG_EXPORT(void,png_set_gray_to_rgb) PNGARG((png_structp png_ptr));
1621 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1622 /* Reduce RGB to grayscale. */
1623 #ifdef PNG_FLOATING_POINT_SUPPORTED
1624 extern PNG_EXPORT(void,png_set_rgb_to_gray) PNGARG((png_structp png_ptr,
1625 int error_action, double red, double green ));
1627 extern PNG_EXPORT(void,png_set_rgb_to_gray_fixed) PNGARG((png_structp png_ptr,
1628 int error_action, png_fixed_point red, png_fixed_point green ));
1629 extern PNG_EXPORT(png_byte,png_get_rgb_to_gray_status) PNGARG((png_structp
1633 extern PNG_EXPORT(void,png_build_grayscale_palette) PNGARG((int bit_depth,
1634 png_colorp palette));
1636 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
1637 extern PNG_EXPORT(void,png_set_strip_alpha) PNGARG((png_structp png_ptr));
1640 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
1641 defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
1642 extern PNG_EXPORT(void,png_set_swap_alpha) PNGARG((png_structp png_ptr));
1645 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
1646 defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
1647 extern PNG_EXPORT(void,png_set_invert_alpha) PNGARG((png_structp png_ptr));
1650 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
1651 /* Add a filler byte to 8-bit Gray or 24-bit RGB images. */
1652 extern PNG_EXPORT(void,png_set_filler) PNGARG((png_structp png_ptr,
1653 png_uint_32 filler, int flags));
1654 /* The values of the PNG_FILLER_ defines should NOT be changed */
1655 #define PNG_FILLER_BEFORE 0
1656 #define PNG_FILLER_AFTER 1
1657 /* Add an alpha byte to 8-bit Gray or 24-bit RGB images. */
1658 extern PNG_EXPORT(void,png_set_add_alpha) PNGARG((png_structp png_ptr,
1659 png_uint_32 filler, int flags));
1660 #endif /* PNG_READ_FILLER_SUPPORTED || PNG_WRITE_FILLER_SUPPORTED */
1662 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
1663 /* Swap bytes in 16-bit depth files. */
1664 extern PNG_EXPORT(void,png_set_swap) PNGARG((png_structp png_ptr));
1667 #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
1668 /* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
1669 extern PNG_EXPORT(void,png_set_packing) PNGARG((png_structp png_ptr));
1672 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
1673 defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1674 /* Swap packing order of pixels in bytes. */
1675 extern PNG_EXPORT(void,png_set_packswap) PNGARG((png_structp png_ptr));
1678 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
1679 /* Converts files to legal bit depths. */
1680 extern PNG_EXPORT(void,png_set_shift) PNGARG((png_structp png_ptr,
1681 png_color_8p true_bits));
1684 #if defined(PNG_READ_INTERLACING_SUPPORTED) || \
1685 defined(PNG_WRITE_INTERLACING_SUPPORTED)
1686 /* Have the code handle the interlacing. Returns the number of passes. */
1687 extern PNG_EXPORT(int,png_set_interlace_handling) PNGARG((png_structp png_ptr));
1690 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
1691 /* Invert monochrome files */
1692 extern PNG_EXPORT(void,png_set_invert_mono) PNGARG((png_structp png_ptr));
1695 #ifdef PNG_READ_BACKGROUND_SUPPORTED
1696 /* Handle alpha and tRNS by replacing with a background color. */
1697 #ifdef PNG_FLOATING_POINT_SUPPORTED
1698 extern PNG_EXPORT(void,png_set_background) PNGARG((png_structp png_ptr,
1699 png_color_16p background_color, int background_gamma_code,
1700 int need_expand, double background_gamma));
1702 #define PNG_BACKGROUND_GAMMA_UNKNOWN 0
1703 #define PNG_BACKGROUND_GAMMA_SCREEN 1
1704 #define PNG_BACKGROUND_GAMMA_FILE 2
1705 #define PNG_BACKGROUND_GAMMA_UNIQUE 3
1708 #ifdef PNG_READ_16_TO_8_SUPPORTED
1709 /* Strip the second byte of information from a 16-bit depth file. */
1710 extern PNG_EXPORT(void,png_set_strip_16) PNGARG((png_structp png_ptr));
1713 #ifdef PNG_READ_DITHER_SUPPORTED
1714 /* Turn on dithering, and reduce the palette to the number of colors
1717 extern PNG_EXPORT(void,png_set_dither) PNGARG((png_structp png_ptr,
1718 png_colorp palette, int num_palette, int maximum_colors,
1719 png_uint_16p histogram, int full_dither));
1722 #ifdef PNG_READ_GAMMA_SUPPORTED
1723 /* Handle gamma correction. Screen_gamma=(display_exponent) */
1724 #ifdef PNG_FLOATING_POINT_SUPPORTED
1725 extern PNG_EXPORT(void,png_set_gamma) PNGARG((png_structp png_ptr,
1726 double screen_gamma, double default_file_gamma));
1731 #ifdef PNG_WRITE_FLUSH_SUPPORTED
1732 /* Set how many lines between output flushes - 0 for no flushing */
1733 extern PNG_EXPORT(void,png_set_flush) PNGARG((png_structp png_ptr, int nrows));
1734 /* Flush the current PNG output buffer */
1735 extern PNG_EXPORT(void,png_write_flush) PNGARG((png_structp png_ptr));
1738 /* Optional update palette with requested transformations */
1739 extern PNG_EXPORT(void,png_start_read_image) PNGARG((png_structp png_ptr));
1741 /* Optional call to update the users info structure */
1742 extern PNG_EXPORT(void,png_read_update_info) PNGARG((png_structp png_ptr,
1743 png_infop info_ptr));
1745 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1746 /* Read one or more rows of image data. */
1747 extern PNG_EXPORT(void,png_read_rows) PNGARG((png_structp png_ptr,
1748 png_bytepp row, png_bytepp display_row, png_uint_32 num_rows));
1751 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1752 /* Read a row of data. */
1753 extern PNG_EXPORT(void,png_read_row) PNGARG((png_structp png_ptr,
1755 png_bytep display_row));
1758 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1759 /* Read the whole image into memory at once. */
1760 extern PNG_EXPORT(void,png_read_image) PNGARG((png_structp png_ptr,
1764 /* Write a row of image data */
1765 extern PNG_EXPORT(void,png_write_row) PNGARG((png_structp png_ptr,
1768 /* Write a few rows of image data */
1769 extern PNG_EXPORT(void,png_write_rows) PNGARG((png_structp png_ptr,
1770 png_bytepp row, png_uint_32 num_rows));
1772 /* Write the image data */
1773 extern PNG_EXPORT(void,png_write_image) PNGARG((png_structp png_ptr,
1776 /* Write the end of the PNG file. */
1777 extern PNG_EXPORT(void,png_write_end) PNGARG((png_structp png_ptr,
1778 png_infop info_ptr));
1780 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1781 /* Read the end of the PNG file. */
1782 extern PNG_EXPORT(void,png_read_end) PNGARG((png_structp png_ptr,
1783 png_infop info_ptr));
1786 /* Free any memory associated with the png_info_struct */
1787 extern PNG_EXPORT(void,png_destroy_info_struct) PNGARG((png_structp png_ptr,
1788 png_infopp info_ptr_ptr));
1790 /* Free any memory associated with the png_struct and the png_info_structs */
1791 extern PNG_EXPORT(void,png_destroy_read_struct) PNGARG((png_structpp
1792 png_ptr_ptr, png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr));
1794 /* Free any memory associated with the png_struct and the png_info_structs */
1795 extern PNG_EXPORT(void,png_destroy_write_struct)
1796 PNGARG((png_structpp png_ptr_ptr, png_infopp info_ptr_ptr));
1798 /* Set the libpng method of handling chunk CRC errors */
1799 extern PNG_EXPORT(void,png_set_crc_action) PNGARG((png_structp png_ptr,
1800 int crit_action, int ancil_action));
1802 /* Values for png_set_crc_action() to say how to handle CRC errors in
1803 * ancillary and critical chunks, and whether to use the data contained
1804 * therein. Note that it is impossible to "discard" data in a critical
1805 * chunk. For versions prior to 0.90, the action was always error/quit,
1806 * whereas in version 0.90 and later, the action for CRC errors in ancillary
1807 * chunks is warn/discard. These values should NOT be changed.
1809 * value action:critical action:ancillary
1811 #define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */
1812 #define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */
1813 #define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */
1814 #define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */
1815 #define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */
1816 #define PNG_CRC_NO_CHANGE 5 /* use current value use current value */
1818 /* These functions give the user control over the scan-line filtering in
1819 * libpng and the compression methods used by zlib. These functions are
1820 * mainly useful for testing, as the defaults should work with most users.
1821 * Those users who are tight on memory or want faster performance at the
1822 * expense of compression can modify them. See the compression library
1823 * header file (zlib.h) for an explination of the compression functions.
1826 /* Set the filtering method(s) used by libpng. Currently, the only valid
1827 * value for "method" is 0.
1829 extern PNG_EXPORT(void,png_set_filter) PNGARG((png_structp png_ptr, int method,
1832 /* Flags for png_set_filter() to say which filters to use. The flags
1833 * are chosen so that they don't conflict with real filter types
1834 * below, in case they are supplied instead of the #defined constants.
1835 * These values should NOT be changed.
1837 #define PNG_NO_FILTERS 0x00
1838 #define PNG_FILTER_NONE 0x08
1839 #define PNG_FILTER_SUB 0x10
1840 #define PNG_FILTER_UP 0x20
1841 #define PNG_FILTER_AVG 0x40
1842 #define PNG_FILTER_PAETH 0x80
1843 #define PNG_ALL_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP | \
1844 PNG_FILTER_AVG | PNG_FILTER_PAETH)
1846 /* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
1847 * These defines should NOT be changed.
1849 #define PNG_FILTER_VALUE_NONE 0
1850 #define PNG_FILTER_VALUE_SUB 1
1851 #define PNG_FILTER_VALUE_UP 2
1852 #define PNG_FILTER_VALUE_AVG 3
1853 #define PNG_FILTER_VALUE_PAETH 4
1854 #define PNG_FILTER_VALUE_LAST 5
1856 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* EXPERIMENTAL */
1857 /* The "heuristic_method" is given by one of the PNG_FILTER_HEURISTIC_
1858 * defines, either the default (minimum-sum-of-absolute-differences), or
1859 * the experimental method (weighted-minimum-sum-of-absolute-differences).
1861 * Weights are factors >= 1.0, indicating how important it is to keep the
1862 * filter type consistent between rows. Larger numbers mean the current
1863 * filter is that many times as likely to be the same as the "num_weights"
1864 * previous filters. This is cumulative for each previous row with a weight.
1865 * There needs to be "num_weights" values in "filter_weights", or it can be
1866 * NULL if the weights aren't being specified. Weights have no influence on
1867 * the selection of the first row filter. Well chosen weights can (in theory)
1868 * improve the compression for a given image.
1870 * Costs are factors >= 1.0 indicating the relative decoding costs of a
1871 * filter type. Higher costs indicate more decoding expense, and are
1872 * therefore less likely to be selected over a filter with lower computational
1873 * costs. There needs to be a value in "filter_costs" for each valid filter
1874 * type (given by PNG_FILTER_VALUE_LAST), or it can be NULL if you aren't
1875 * setting the costs. Costs try to improve the speed of decompression without
1876 * unduly increasing the compressed image size.
1878 * A negative weight or cost indicates the default value is to be used, and
1879 * values in the range [0.0, 1.0) indicate the value is to remain unchanged.
1880 * The default values for both weights and costs are currently 1.0, but may
1881 * change if good general weighting/cost heuristics can be found. If both
1882 * the weights and costs are set to 1.0, this degenerates the WEIGHTED method
1883 * to the UNWEIGHTED method, but with added encoding time/computation.
1885 #ifdef PNG_FLOATING_POINT_SUPPORTED
1886 extern PNG_EXPORT(void,png_set_filter_heuristics) PNGARG((png_structp png_ptr,
1887 int heuristic_method, int num_weights, png_doublep filter_weights,
1888 png_doublep filter_costs));
1890 #endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
1892 /* Heuristic used for row filter selection. These defines should NOT be
1895 #define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */
1896 #define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */
1897 #define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */
1898 #define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */
1900 /* Set the library compression level. Currently, valid values range from
1901 * 0 - 9, corresponding directly to the zlib compression levels 0 - 9
1902 * (0 - no compression, 9 - "maximal" compression). Note that tests have
1903 * shown that zlib compression levels 3-6 usually perform as well as level 9
1904 * for PNG images, and do considerably fewer caclulations. In the future,
1905 * these values may not correspond directly to the zlib compression levels.
1907 extern PNG_EXPORT(void,png_set_compression_level) PNGARG((png_structp png_ptr,
1910 extern PNG_EXPORT(void,png_set_compression_mem_level)
1911 PNGARG((png_structp png_ptr, int mem_level));
1913 extern PNG_EXPORT(void,png_set_compression_strategy)
1914 PNGARG((png_structp png_ptr, int strategy));
1916 extern PNG_EXPORT(void,png_set_compression_window_bits)
1917 PNGARG((png_structp png_ptr, int window_bits));
1919 extern PNG_EXPORT(void,png_set_compression_method) PNGARG((png_structp png_ptr,
1922 /* These next functions are called for input/output, memory, and error
1923 * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c,
1924 * and call standard C I/O routines such as fread(), fwrite(), and
1925 * fprintf(). These functions can be made to use other I/O routines
1926 * at run time for those applications that need to handle I/O in a
1927 * different manner by calling png_set_???_fn(). See libpng.txt for
1931 #ifdef PNG_STDIO_SUPPORTED
1932 /* Initialize the input/output for the PNG file to the default functions. */
1933 extern PNG_EXPORT(void,png_init_io) PNGARG((png_structp png_ptr,
1937 /* Replace the (error and abort), and warning functions with user
1938 * supplied functions. If no messages are to be printed you must still
1939 * write and use replacement functions. The replacement error_fn should
1940 * still do a longjmp to the last setjmp location if you are using this
1941 * method of error handling. If error_fn or warning_fn is NULL, the
1942 * default function will be used.
1945 extern PNG_EXPORT(void,png_set_error_fn) PNGARG((png_structp png_ptr,
1946 png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn));
1948 /* Return the user pointer associated with the error functions */
1949 extern PNG_EXPORT(png_voidp,png_get_error_ptr) PNGARG((png_structp png_ptr));
1951 /* Replace the default data output functions with a user supplied one(s).
1952 * If buffered output is not used, then output_flush_fn can be set to NULL.
1953 * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time
1954 * output_flush_fn will be ignored (and thus can be NULL).
1955 * It is probably a mistake to use NULL for output_flush_fn if
1956 * write_data_fn is not also NULL unless you have built libpng with
1957 * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's
1958 * default flush function, which uses the standard *FILE structure, will
1961 extern PNG_EXPORT(void,png_set_write_fn) PNGARG((png_structp png_ptr,
1962 png_voidp io_ptr, png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn));
1964 /* Replace the default data input function with a user supplied one. */
1965 extern PNG_EXPORT(void,png_set_read_fn) PNGARG((png_structp png_ptr,
1966 png_voidp io_ptr, png_rw_ptr read_data_fn));
1968 /* Return the user pointer associated with the I/O functions */
1969 extern PNG_EXPORT(png_voidp,png_get_io_ptr) PNGARG((png_structp png_ptr));
1971 extern PNG_EXPORT(void,png_set_read_status_fn) PNGARG((png_structp png_ptr,
1972 png_read_status_ptr read_row_fn));
1974 extern PNG_EXPORT(void,png_set_write_status_fn) PNGARG((png_structp png_ptr,
1975 png_write_status_ptr write_row_fn));
1977 #ifdef PNG_USER_MEM_SUPPORTED
1978 /* Replace the default memory allocation functions with user supplied one(s). */
1979 extern PNG_EXPORT(void,png_set_mem_fn) PNGARG((png_structp png_ptr,
1980 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn));
1981 /* Return the user pointer associated with the memory functions */
1982 extern PNG_EXPORT(png_voidp,png_get_mem_ptr) PNGARG((png_structp png_ptr));
1985 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
1986 extern PNG_EXPORT(void,png_set_read_user_transform_fn) PNGARG((png_structp
1987 png_ptr, png_user_transform_ptr read_user_transform_fn));
1990 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
1991 extern PNG_EXPORT(void,png_set_write_user_transform_fn) PNGARG((png_structp
1992 png_ptr, png_user_transform_ptr write_user_transform_fn));
1995 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
1996 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
1997 extern PNG_EXPORT(void,png_set_user_transform_info) PNGARG((png_structp
1998 png_ptr, png_voidp user_transform_ptr, int user_transform_depth,
1999 int user_transform_channels));
2000 /* Return the user pointer associated with the user transform functions */
2001 extern PNG_EXPORT(png_voidp,png_get_user_transform_ptr)
2002 PNGARG((png_structp png_ptr));
2005 #ifdef PNG_USER_CHUNKS_SUPPORTED
2006 extern PNG_EXPORT(void,png_set_read_user_chunk_fn) PNGARG((png_structp png_ptr,
2007 png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));
2008 extern PNG_EXPORT(png_voidp,png_get_user_chunk_ptr) PNGARG((png_structp
2012 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
2013 /* Sets the function callbacks for the push reader, and a pointer to a
2014 * user-defined structure available to the callback functions.
2016 extern PNG_EXPORT(void,png_set_progressive_read_fn) PNGARG((png_structp png_ptr,
2017 png_voidp progressive_ptr,
2018 png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
2019 png_progressive_end_ptr end_fn));
2021 /* Returns the user pointer associated with the push read functions */
2022 extern PNG_EXPORT(png_voidp,png_get_progressive_ptr)
2023 PNGARG((png_structp png_ptr));
2025 /* Function to be called when data becomes available */
2026 extern PNG_EXPORT(void,png_process_data) PNGARG((png_structp png_ptr,
2027 png_infop info_ptr, png_bytep buffer, png_size_t buffer_size));
2029 /* Function that combines rows. Not very much different than the
2030 * png_combine_row() call. Is this even used?????
2032 extern PNG_EXPORT(void,png_progressive_combine_row) PNGARG((png_structp png_ptr,
2033 png_bytep old_row, png_bytep new_row));
2034 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
2036 extern PNG_EXPORT(png_voidp,png_malloc) PNGARG((png_structp png_ptr,
2037 png_alloc_size_t size)) PNG_ALLOCATED;
2038 /* Added at libpng version 1.4.0 */
2039 extern PNG_EXPORT(png_voidp,png_calloc) PNGARG((png_structp png_ptr,
2040 png_alloc_size_t size)) PNG_ALLOCATED;
2042 /* Added at libpng version 1.2.4 */
2043 extern PNG_EXPORT(png_voidp,png_malloc_warn) PNGARG((png_structp png_ptr,
2044 png_alloc_size_t size)) PNG_ALLOCATED;
2046 /* Frees a pointer allocated by png_malloc() */
2047 extern PNG_EXPORT(void,png_free) PNGARG((png_structp png_ptr, png_voidp ptr));
2049 /* Free data that was allocated internally */
2050 extern PNG_EXPORT(void,png_free_data) PNGARG((png_structp png_ptr,
2051 png_infop info_ptr, png_uint_32 free_me, int num));
2052 /* Reassign responsibility for freeing existing data, whether allocated
2053 * by libpng or by the application */
2054 extern PNG_EXPORT(void,png_data_freer) PNGARG((png_structp png_ptr,
2055 png_infop info_ptr, int freer, png_uint_32 mask));
2056 /* Assignments for png_data_freer */
2057 #define PNG_DESTROY_WILL_FREE_DATA 1
2058 #define PNG_SET_WILL_FREE_DATA 1
2059 #define PNG_USER_WILL_FREE_DATA 2
2060 /* Flags for png_ptr->free_me and info_ptr->free_me */
2061 #define PNG_FREE_HIST 0x0008
2062 #define PNG_FREE_ICCP 0x0010
2063 #define PNG_FREE_SPLT 0x0020
2064 #define PNG_FREE_ROWS 0x0040
2065 #define PNG_FREE_PCAL 0x0080
2066 #define PNG_FREE_SCAL 0x0100
2067 #define PNG_FREE_UNKN 0x0200
2068 #define PNG_FREE_LIST 0x0400
2069 #define PNG_FREE_PLTE 0x1000
2070 #define PNG_FREE_TRNS 0x2000
2071 #define PNG_FREE_TEXT 0x4000
2072 #define PNG_FREE_ALL 0x7fff
2073 #define PNG_FREE_MUL 0x4220 /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */
2075 #ifdef PNG_USER_MEM_SUPPORTED
2076 extern PNG_EXPORT(png_voidp,png_malloc_default) PNGARG((png_structp png_ptr,
2077 png_alloc_size_t size)) PNG_ALLOCATED;
2078 extern PNG_EXPORT(void,png_free_default) PNGARG((png_structp png_ptr,
2082 #ifndef PNG_NO_ERROR_TEXT
2083 /* Fatal error in PNG image of libpng - can't continue */
2084 extern PNG_EXPORT(void,png_error) PNGARG((png_structp png_ptr,
2085 png_const_charp error_message)) PNG_NORETURN;
2087 /* The same, but the chunk name is prepended to the error string. */
2088 extern PNG_EXPORT(void,png_chunk_error) PNGARG((png_structp png_ptr,
2089 png_const_charp error_message)) PNG_NORETURN;
2092 /* Fatal error in PNG image of libpng - can't continue */
2093 extern PNG_EXPORT(void,png_err) PNGARG((png_structp png_ptr)) PNG_NORETURN;
2096 /* Non-fatal error in libpng. Can continue, but may have a problem. */
2097 extern PNG_EXPORT(void,png_warning) PNGARG((png_structp png_ptr,
2098 png_const_charp warning_message));
2100 /* Non-fatal error in libpng, chunk name is prepended to message. */
2101 extern PNG_EXPORT(void,png_chunk_warning) PNGARG((png_structp png_ptr,
2102 png_const_charp warning_message));
2104 #ifdef PNG_BENIGN_ERRORS_SUPPORTED
2105 /* Benign error in libpng. Can continue, but may have a problem.
2106 * User can choose whether to handle as a fatal error or as a warning. */
2107 extern PNG_EXPORT(void,png_benign_error) PNGARG((png_structp png_ptr,
2108 png_const_charp warning_message));
2110 /* Same, chunk name is prepended to message. */
2111 extern PNG_EXPORT(void,png_chunk_benign_error) PNGARG((png_structp png_ptr,
2112 png_const_charp warning_message));
2114 extern PNG_EXPORT(void,png_set_benign_errors) PNGARG((png_structp
2115 png_ptr, int allowed));
2118 /* The png_set_<chunk> functions are for storing values in the png_info_struct.
2119 * Similarly, the png_get_<chunk> calls are used to read values from the
2120 * png_info_struct, either storing the parameters in the passed variables, or
2121 * setting pointers into the png_info_struct where the data is stored. The
2122 * png_get_<chunk> functions return a non-zero value if the data was available
2123 * in info_ptr, or return zero and do not change any of the parameters if the
2124 * data was not available.
2126 * These functions should be used instead of directly accessing png_info
2127 * to avoid problems with future changes in the size and internal layout of
2130 /* Returns "flag" if chunk data is valid in info_ptr. */
2131 extern PNG_EXPORT(png_uint_32,png_get_valid) PNGARG((png_structp png_ptr,
2132 png_infop info_ptr, png_uint_32 flag));
2134 /* Returns number of bytes needed to hold a transformed row. */
2135 extern PNG_EXPORT(png_size_t,png_get_rowbytes) PNGARG((png_structp png_ptr,
2136 png_infop info_ptr));
2138 #ifdef PNG_INFO_IMAGE_SUPPORTED
2139 /* Returns row_pointers, which is an array of pointers to scanlines that was
2140 * returned from png_read_png().
2142 extern PNG_EXPORT(png_bytepp,png_get_rows) PNGARG((png_structp png_ptr,
2143 png_infop info_ptr));
2144 /* Set row_pointers, which is an array of pointers to scanlines for use
2145 * by png_write_png().
2147 extern PNG_EXPORT(void,png_set_rows) PNGARG((png_structp png_ptr,
2148 png_infop info_ptr, png_bytepp row_pointers));
2151 /* Returns number of color channels in image. */
2152 extern PNG_EXPORT(png_byte,png_get_channels) PNGARG((png_structp png_ptr,
2153 png_infop info_ptr));
2155 #ifdef PNG_EASY_ACCESS_SUPPORTED
2156 /* Returns image width in pixels. */
2157 extern PNG_EXPORT(png_uint_32, png_get_image_width) PNGARG((png_structp
2158 png_ptr, png_infop info_ptr));
2160 /* Returns image height in pixels. */
2161 extern PNG_EXPORT(png_uint_32, png_get_image_height) PNGARG((png_structp
2162 png_ptr, png_infop info_ptr));
2164 /* Returns image bit_depth. */
2165 extern PNG_EXPORT(png_byte, png_get_bit_depth) PNGARG((png_structp
2166 png_ptr, png_infop info_ptr));
2168 /* Returns image color_type. */
2169 extern PNG_EXPORT(png_byte, png_get_color_type) PNGARG((png_structp
2170 png_ptr, png_infop info_ptr));
2172 /* Returns image filter_type. */
2173 extern PNG_EXPORT(png_byte, png_get_filter_type) PNGARG((png_structp
2174 png_ptr, png_infop info_ptr));
2176 /* Returns image interlace_type. */
2177 extern PNG_EXPORT(png_byte, png_get_interlace_type) PNGARG((png_structp
2178 png_ptr, png_infop info_ptr));
2180 /* Returns image compression_type. */
2181 extern PNG_EXPORT(png_byte, png_get_compression_type) PNGARG((png_structp
2182 png_ptr, png_infop info_ptr));
2184 /* Returns image resolution in pixels per meter, from pHYs chunk data. */
2185 extern PNG_EXPORT(png_uint_32, png_get_pixels_per_meter) PNGARG((png_structp
2186 png_ptr, png_infop info_ptr));
2187 extern PNG_EXPORT(png_uint_32, png_get_x_pixels_per_meter) PNGARG((png_structp
2188 png_ptr, png_infop info_ptr));
2189 extern PNG_EXPORT(png_uint_32, png_get_y_pixels_per_meter) PNGARG((png_structp
2190 png_ptr, png_infop info_ptr));
2192 /* Returns pixel aspect ratio, computed from pHYs chunk data. */
2193 #ifdef PNG_FLOATING_POINT_SUPPORTED
2194 extern PNG_EXPORT(float, png_get_pixel_aspect_ratio) PNGARG((png_structp
2195 png_ptr, png_infop info_ptr));
2198 /* Returns image x, y offset in pixels or microns, from oFFs chunk data. */
2199 extern PNG_EXPORT(png_int_32, png_get_x_offset_pixels) PNGARG((png_structp
2200 png_ptr, png_infop info_ptr));
2201 extern PNG_EXPORT(png_int_32, png_get_y_offset_pixels) PNGARG((png_structp
2202 png_ptr, png_infop info_ptr));
2203 extern PNG_EXPORT(png_int_32, png_get_x_offset_microns) PNGARG((png_structp
2204 png_ptr, png_infop info_ptr));
2205 extern PNG_EXPORT(png_int_32, png_get_y_offset_microns) PNGARG((png_structp
2206 png_ptr, png_infop info_ptr));
2208 #endif /* PNG_EASY_ACCESS_SUPPORTED */
2210 /* Returns pointer to signature string read from PNG header */
2211 extern PNG_EXPORT(png_bytep,png_get_signature) PNGARG((png_structp png_ptr,
2212 png_infop info_ptr));
2214 #ifdef PNG_bKGD_SUPPORTED
2215 extern PNG_EXPORT(png_uint_32,png_get_bKGD) PNGARG((png_structp png_ptr,
2216 png_infop info_ptr, png_color_16p *background));
2219 #ifdef PNG_bKGD_SUPPORTED
2220 extern PNG_EXPORT(void,png_set_bKGD) PNGARG((png_structp png_ptr,
2221 png_infop info_ptr, png_color_16p background));
2224 #ifdef PNG_cHRM_SUPPORTED
2225 #ifdef PNG_FLOATING_POINT_SUPPORTED
2226 extern PNG_EXPORT(png_uint_32,png_get_cHRM) PNGARG((png_structp png_ptr,
2227 png_infop info_ptr, double *white_x, double *white_y, double *red_x,
2228 double *red_y, double *green_x, double *green_y, double *blue_x,
2231 #ifdef PNG_FIXED_POINT_SUPPORTED
2232 extern PNG_EXPORT(png_uint_32,png_get_cHRM_fixed) PNGARG((png_structp png_ptr,
2233 png_infop info_ptr, png_fixed_point *int_white_x, png_fixed_point
2234 *int_white_y, png_fixed_point *int_red_x, png_fixed_point *int_red_y,
2235 png_fixed_point *int_green_x, png_fixed_point *int_green_y, png_fixed_point
2236 *int_blue_x, png_fixed_point *int_blue_y));
2240 #ifdef PNG_cHRM_SUPPORTED
2241 #ifdef PNG_FLOATING_POINT_SUPPORTED
2242 extern PNG_EXPORT(void,png_set_cHRM) PNGARG((png_structp png_ptr,
2243 png_infop info_ptr, double white_x, double white_y, double red_x,
2244 double red_y, double green_x, double green_y, double blue_x, double blue_y));
2246 #ifdef PNG_FIXED_POINT_SUPPORTED
2247 extern PNG_EXPORT(void,png_set_cHRM_fixed) PNGARG((png_structp png_ptr,
2248 png_infop info_ptr, png_fixed_point int_white_x, png_fixed_point int_white_y,
2249 png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
2250 int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
2251 png_fixed_point int_blue_y));
2255 #ifdef PNG_gAMA_SUPPORTED
2256 #ifdef PNG_FLOATING_POINT_SUPPORTED
2257 extern PNG_EXPORT(png_uint_32,png_get_gAMA) PNGARG((png_structp png_ptr,
2258 png_infop info_ptr, double *file_gamma));
2260 extern PNG_EXPORT(png_uint_32,png_get_gAMA_fixed) PNGARG((png_structp png_ptr,
2261 png_infop info_ptr, png_fixed_point *int_file_gamma));
2264 #ifdef PNG_gAMA_SUPPORTED
2265 #ifdef PNG_FLOATING_POINT_SUPPORTED
2266 extern PNG_EXPORT(void,png_set_gAMA) PNGARG((png_structp png_ptr,
2267 png_infop info_ptr, double file_gamma));
2269 extern PNG_EXPORT(void,png_set_gAMA_fixed) PNGARG((png_structp png_ptr,
2270 png_infop info_ptr, png_fixed_point int_file_gamma));
2273 #ifdef PNG_hIST_SUPPORTED
2274 extern PNG_EXPORT(png_uint_32,png_get_hIST) PNGARG((png_structp png_ptr,
2275 png_infop info_ptr, png_uint_16p *hist));
2278 #ifdef PNG_hIST_SUPPORTED
2279 extern PNG_EXPORT(void,png_set_hIST) PNGARG((png_structp png_ptr,
2280 png_infop info_ptr, png_uint_16p hist));
2283 extern PNG_EXPORT(png_uint_32,png_get_IHDR) PNGARG((png_structp png_ptr,
2284 png_infop info_ptr, png_uint_32 *width, png_uint_32 *height,
2285 int *bit_depth, int *color_type, int *interlace_method,
2286 int *compression_method, int *filter_method));
2288 extern PNG_EXPORT(void,png_set_IHDR) PNGARG((png_structp png_ptr,
2289 png_infop info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth,
2290 int color_type, int interlace_method, int compression_method,
2291 int filter_method));
2293 #ifdef PNG_oFFs_SUPPORTED
2294 extern PNG_EXPORT(png_uint_32,png_get_oFFs) PNGARG((png_structp png_ptr,
2295 png_infop info_ptr, png_int_32 *offset_x, png_int_32 *offset_y,
2299 #ifdef PNG_oFFs_SUPPORTED
2300 extern PNG_EXPORT(void,png_set_oFFs) PNGARG((png_structp png_ptr,
2301 png_infop info_ptr, png_int_32 offset_x, png_int_32 offset_y,
2305 #ifdef PNG_pCAL_SUPPORTED
2306 extern PNG_EXPORT(png_uint_32,png_get_pCAL) PNGARG((png_structp png_ptr,
2307 png_infop info_ptr, png_charp *purpose, png_int_32 *X0, png_int_32 *X1,
2308 int *type, int *nparams, png_charp *units, png_charpp *params));
2311 #ifdef PNG_pCAL_SUPPORTED
2312 extern PNG_EXPORT(void,png_set_pCAL) PNGARG((png_structp png_ptr,
2313 png_infop info_ptr, png_charp purpose, png_int_32 X0, png_int_32 X1,
2314 int type, int nparams, png_charp units, png_charpp params));
2317 #ifdef PNG_pHYs_SUPPORTED
2318 extern PNG_EXPORT(png_uint_32,png_get_pHYs) PNGARG((png_structp png_ptr,
2319 png_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type));
2322 #ifdef PNG_pHYs_SUPPORTED
2323 extern PNG_EXPORT(void,png_set_pHYs) PNGARG((png_structp png_ptr,
2324 png_infop info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type));
2327 extern PNG_EXPORT(png_uint_32,png_get_PLTE) PNGARG((png_structp png_ptr,
2328 png_infop info_ptr, png_colorp *palette, int *num_palette));
2330 extern PNG_EXPORT(void,png_set_PLTE) PNGARG((png_structp png_ptr,
2331 png_infop info_ptr, png_colorp palette, int num_palette));
2333 #ifdef PNG_sBIT_SUPPORTED
2334 extern PNG_EXPORT(png_uint_32,png_get_sBIT) PNGARG((png_structp png_ptr,
2335 png_infop info_ptr, png_color_8p *sig_bit));
2338 #ifdef PNG_sBIT_SUPPORTED
2339 extern PNG_EXPORT(void,png_set_sBIT) PNGARG((png_structp png_ptr,
2340 png_infop info_ptr, png_color_8p sig_bit));
2343 #ifdef PNG_sRGB_SUPPORTED
2344 extern PNG_EXPORT(png_uint_32,png_get_sRGB) PNGARG((png_structp png_ptr,
2345 png_infop info_ptr, int *intent));
2348 #ifdef PNG_sRGB_SUPPORTED
2349 extern PNG_EXPORT(void,png_set_sRGB) PNGARG((png_structp png_ptr,
2350 png_infop info_ptr, int intent));
2351 extern PNG_EXPORT(void,png_set_sRGB_gAMA_and_cHRM) PNGARG((png_structp png_ptr,
2352 png_infop info_ptr, int intent));
2355 #ifdef PNG_iCCP_SUPPORTED
2356 extern PNG_EXPORT(png_uint_32,png_get_iCCP) PNGARG((png_structp png_ptr,
2357 png_infop info_ptr, png_charpp name, int *compression_type,
2358 png_charpp profile, png_uint_32 *proflen));
2359 /* Note to maintainer: profile should be png_bytepp */
2362 #ifdef PNG_iCCP_SUPPORTED
2363 extern PNG_EXPORT(void,png_set_iCCP) PNGARG((png_structp png_ptr,
2364 png_infop info_ptr, png_charp name, int compression_type,
2365 png_charp profile, png_uint_32 proflen));
2366 /* Note to maintainer: profile should be png_bytep */
2369 #ifdef PNG_sPLT_SUPPORTED
2370 extern PNG_EXPORT(png_uint_32,png_get_sPLT) PNGARG((png_structp png_ptr,
2371 png_infop info_ptr, png_sPLT_tpp entries));
2374 #ifdef PNG_sPLT_SUPPORTED
2375 extern PNG_EXPORT(void,png_set_sPLT) PNGARG((png_structp png_ptr,
2376 png_infop info_ptr, png_sPLT_tp entries, int nentries));
2379 #ifdef PNG_TEXT_SUPPORTED
2380 /* png_get_text also returns the number of text chunks in *num_text */
2381 extern PNG_EXPORT(png_uint_32,png_get_text) PNGARG((png_structp png_ptr,
2382 png_infop info_ptr, png_textp *text_ptr, int *num_text));
2385 /* Note while png_set_text() will accept a structure whose text,
2386 * language, and translated keywords are NULL pointers, the structure
2387 * returned by png_get_text will always contain regular
2388 * zero-terminated C strings. They might be empty strings but
2389 * they will never be NULL pointers.
2392 #ifdef PNG_TEXT_SUPPORTED
2393 extern PNG_EXPORT(void,png_set_text) PNGARG((png_structp png_ptr,
2394 png_infop info_ptr, png_textp text_ptr, int num_text));
2397 #ifdef PNG_tIME_SUPPORTED
2398 extern PNG_EXPORT(png_uint_32,png_get_tIME) PNGARG((png_structp png_ptr,
2399 png_infop info_ptr, png_timep *mod_time));
2402 #ifdef PNG_tIME_SUPPORTED
2403 extern PNG_EXPORT(void,png_set_tIME) PNGARG((png_structp png_ptr,
2404 png_infop info_ptr, png_timep mod_time));
2407 #ifdef PNG_tRNS_SUPPORTED
2408 extern PNG_EXPORT(png_uint_32,png_get_tRNS) PNGARG((png_structp png_ptr,
2409 png_infop info_ptr, png_bytep *trans_alpha, int *num_trans,
2410 png_color_16p *trans_color));
2413 #ifdef PNG_tRNS_SUPPORTED
2414 extern PNG_EXPORT(void,png_set_tRNS) PNGARG((png_structp png_ptr,
2415 png_infop info_ptr, png_bytep trans_alpha, int num_trans,
2416 png_color_16p trans_color));
2419 #ifdef PNG_tRNS_SUPPORTED
2422 #ifdef PNG_sCAL_SUPPORTED
2423 #ifdef PNG_FLOATING_POINT_SUPPORTED
2424 extern PNG_EXPORT(png_uint_32,png_get_sCAL) PNGARG((png_structp png_ptr,
2425 png_infop info_ptr, int *unit, double *width, double *height));
2427 #ifdef PNG_FIXED_POINT_SUPPORTED
2428 extern PNG_EXPORT(png_uint_32,png_get_sCAL_s) PNGARG((png_structp png_ptr,
2429 png_infop info_ptr, int *unit, png_charpp swidth, png_charpp sheight));
2432 #endif /* PNG_sCAL_SUPPORTED */
2434 #ifdef PNG_sCAL_SUPPORTED
2435 #ifdef PNG_FLOATING_POINT_SUPPORTED
2436 extern PNG_EXPORT(void,png_set_sCAL) PNGARG((png_structp png_ptr,
2437 png_infop info_ptr, int unit, double width, double height));
2439 #ifdef PNG_FIXED_POINT_SUPPORTED
2440 extern PNG_EXPORT(void,png_set_sCAL_s) PNGARG((png_structp png_ptr,
2441 png_infop info_ptr, int unit, png_charp swidth, png_charp sheight));
2444 #endif /* PNG_sCAL_SUPPORTED || PNG_WRITE_sCAL_SUPPORTED */
2446 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
2447 /* Provide a list of chunks and how they are to be handled, if the built-in
2448 handling or default unknown chunk handling is not desired. Any chunks not
2449 listed will be handled in the default manner. The IHDR and IEND chunks
2451 keep = 0: follow default behaviour
2453 = 2: keep only if safe-to-copy
2454 = 3: keep even if unsafe-to-copy
2456 extern PNG_EXPORT(void, png_set_keep_unknown_chunks) PNGARG((png_structp
2457 png_ptr, int keep, png_bytep chunk_list, int num_chunks));
2458 PNG_EXPORT(int,png_handle_as_unknown) PNGARG((png_structp png_ptr, png_bytep
2461 #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
2462 extern PNG_EXPORT(void, png_set_unknown_chunks) PNGARG((png_structp png_ptr,
2463 png_infop info_ptr, png_unknown_chunkp unknowns, int num_unknowns));
2464 extern PNG_EXPORT(void, png_set_unknown_chunk_location)
2465 PNGARG((png_structp png_ptr, png_infop info_ptr, int chunk, int location));
2466 extern PNG_EXPORT(png_uint_32,png_get_unknown_chunks) PNGARG((png_structp
2467 png_ptr, png_infop info_ptr, png_unknown_chunkpp entries));
2470 /* Png_free_data() will turn off the "valid" flag for anything it frees.
2471 * If you need to turn it off for a chunk that your application has freed,
2472 * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK);
2474 extern PNG_EXPORT(void, png_set_invalid) PNGARG((png_structp png_ptr,
2475 png_infop info_ptr, int mask));
2477 #ifdef PNG_INFO_IMAGE_SUPPORTED
2478 /* The "params" pointer is currently not used and is for future expansion. */
2479 extern PNG_EXPORT(void, png_read_png) PNGARG((png_structp png_ptr,
2483 extern PNG_EXPORT(void, png_write_png) PNGARG((png_structp png_ptr,
2489 extern PNG_EXPORT(png_charp,png_get_copyright) PNGARG((png_structp png_ptr));
2490 extern PNG_EXPORT(png_charp,png_get_header_ver) PNGARG((png_structp png_ptr));
2491 extern PNG_EXPORT(png_charp,png_get_header_version) PNGARG((png_structp
2493 extern PNG_EXPORT(png_charp,png_get_libpng_ver) PNGARG((png_structp png_ptr));
2495 #ifdef PNG_MNG_FEATURES_SUPPORTED
2496 extern PNG_EXPORT(png_uint_32,png_permit_mng_features) PNGARG((png_structp
2497 png_ptr, png_uint_32 mng_features_permitted));
2500 /* For use in png_set_keep_unknown, added to version 1.2.6 */
2501 #define PNG_HANDLE_CHUNK_AS_DEFAULT 0
2502 #define PNG_HANDLE_CHUNK_NEVER 1
2503 #define PNG_HANDLE_CHUNK_IF_SAFE 2
2504 #define PNG_HANDLE_CHUNK_ALWAYS 3
2506 /* Strip the prepended error numbers ("#nnn ") from error and warning
2507 * messages before passing them to the error or warning handler.
2509 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
2510 extern PNG_EXPORT(void,png_set_strip_error_numbers) PNGARG((png_structp
2511 png_ptr, png_uint_32 strip_mode));
2514 /* Added in libpng-1.2.6 */
2515 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
2516 extern PNG_EXPORT(void,png_set_user_limits) PNGARG((png_structp
2517 png_ptr, png_uint_32 user_width_max, png_uint_32 user_height_max));
2518 extern PNG_EXPORT(png_uint_32,png_get_user_width_max) PNGARG((png_structp
2520 extern PNG_EXPORT(png_uint_32,png_get_user_height_max) PNGARG((png_structp
2522 /* Added in libpng-1.4.0 */
2523 extern PNG_EXPORT(void,png_set_chunk_cache_max) PNGARG((png_structp
2524 png_ptr, png_uint_32 user_chunk_cache_max));
2525 extern PNG_EXPORT(png_uint_32,png_get_chunk_cache_max)
2526 PNGARG((png_structp png_ptr));
2527 /* Added in libpng-1.4.1 */
2528 extern PNG_EXPORT(void,png_set_chunk_malloc_max) PNGARG((png_structp
2529 png_ptr, png_alloc_size_t user_chunk_cache_max));
2530 extern PNG_EXPORT(png_alloc_size_t,png_get_chunk_malloc_max)
2531 PNGARG((png_structp png_ptr));
2534 #if defined(PNG_INCH_CONVERSIONS) && defined(PNG_FLOATING_POINT_SUPPORTED)
2535 PNG_EXPORT(png_uint_32,png_get_pixels_per_inch) PNGARG((png_structp png_ptr,
2536 png_infop info_ptr));
2538 PNG_EXPORT(png_uint_32,png_get_x_pixels_per_inch) PNGARG((png_structp png_ptr,
2539 png_infop info_ptr));
2541 PNG_EXPORT(png_uint_32,png_get_y_pixels_per_inch) PNGARG((png_structp png_ptr,
2542 png_infop info_ptr));
2544 PNG_EXPORT(float,png_get_x_offset_inches) PNGARG((png_structp png_ptr,
2545 png_infop info_ptr));
2547 PNG_EXPORT(float,png_get_y_offset_inches) PNGARG((png_structp png_ptr,
2548 png_infop info_ptr));
2550 #ifdef PNG_pHYs_SUPPORTED
2551 PNG_EXPORT(png_uint_32,png_get_pHYs_dpi) PNGARG((png_structp png_ptr,
2552 png_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type));
2553 #endif /* PNG_pHYs_SUPPORTED */
2554 #endif /* PNG_INCH_CONVERSIONS && PNG_FLOATING_POINT_SUPPORTED */
2556 /* Added in libpng-1.4.0 */
2557 #ifdef PNG_IO_STATE_SUPPORTED
2558 extern PNG_EXPORT(png_uint_32,png_get_io_state) PNGARG((png_structp png_ptr));
2560 extern PNG_EXPORT(png_bytep,png_get_io_chunk_name)
2561 PNGARG((png_structp png_ptr));
2563 /* The flags returned by png_get_io_state() are the following: */
2564 #define PNG_IO_NONE 0x0000 /* no I/O at this moment */
2565 #define PNG_IO_READING 0x0001 /* currently reading */
2566 #define PNG_IO_WRITING 0x0002 /* currently writing */
2567 #define PNG_IO_SIGNATURE 0x0010 /* currently at the file signature */
2568 #define PNG_IO_CHUNK_HDR 0x0020 /* currently at the chunk header */
2569 #define PNG_IO_CHUNK_DATA 0x0040 /* currently at the chunk data */
2570 #define PNG_IO_CHUNK_CRC 0x0080 /* currently at the chunk crc */
2571 #define PNG_IO_MASK_OP 0x000f /* current operation: reading/writing */
2572 #define PNG_IO_MASK_LOC 0x00f0 /* current location: sig/hdr/data/crc */
2573 #endif /* ?PNG_IO_STATE_SUPPORTED */
2575 /* Maintainer: Put new public prototypes here ^, in libpng.3, and project
2579 #ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
2580 /* With these routines we avoid an integer divide, which will be slower on
2581 * most machines. However, it does take more operations than the corresponding
2582 * divide method, so it may be slower on a few RISC systems. There are two
2583 * shifts (by 8 or 16 bits) and an addition, versus a single integer divide.
2585 * Note that the rounding factors are NOT supposed to be the same! 128 and
2586 * 32768 are correct for the NODIV code; 127 and 32767 are correct for the
2589 * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
2592 /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */
2594 # define png_composite(composite, fg, alpha, bg) \
2595 { png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \
2596 * (png_uint_16)(alpha) \
2597 + (png_uint_16)(bg)*(png_uint_16)(255 \
2598 - (png_uint_16)(alpha)) + (png_uint_16)128); \
2599 (composite) = (png_byte)((temp + (temp >> 8)) >> 8); }
2601 # define png_composite_16(composite, fg, alpha, bg) \
2602 { png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) \
2603 * (png_uint_32)(alpha) \
2604 + (png_uint_32)(bg)*(png_uint_32)(65535L \
2605 - (png_uint_32)(alpha)) + (png_uint_32)32768L); \
2606 (composite) = (png_uint_16)((temp + (temp >> 16)) >> 16); }
2608 #else /* Standard method using integer division */
2610 # define png_composite(composite, fg, alpha, bg) \
2611 (composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) + \
2612 (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \
2613 (png_uint_16)127) / 255)
2615 # define png_composite_16(composite, fg, alpha, bg) \
2616 (composite) = (png_uint_16)(((png_uint_32)(fg) * (png_uint_32)(alpha) + \
2617 (png_uint_32)(bg)*(png_uint_32)(65535L - (png_uint_32)(alpha)) + \
2618 (png_uint_32)32767) / (png_uint_32)65535L)
2619 #endif /* PNG_READ_COMPOSITE_NODIV_SUPPORTED */
2621 #ifdef PNG_USE_READ_MACROS
2622 /* Inline macros to do direct reads of bytes from the input buffer.
2623 * The png_get_int_32() routine assumes we are using two's complement
2624 * format for negative values, which is almost certainly true.
2626 /* We could make special-case BIG_ENDIAN macros that do direct reads here */
2627 # define png_get_uint_32(buf) \
2628 (((png_uint_32)(*(buf)) << 24) + \
2629 ((png_uint_32)(*((buf) + 1)) << 16) + \
2630 ((png_uint_32)(*((buf) + 2)) << 8) + \
2631 ((png_uint_32)(*((buf) + 3))))
2632 # define png_get_uint_16(buf) \
2633 (((png_uint_32)(*(buf)) << 8) + \
2634 ((png_uint_32)(*((buf) + 1))))
2635 #ifdef PNG_GET_INT_32_SUPPORTED
2636 # define png_get_int_32(buf) \
2637 (((png_int_32)(*(buf)) << 24) + \
2638 ((png_int_32)(*((buf) + 1)) << 16) + \
2639 ((png_int_32)(*((buf) + 2)) << 8) + \
2640 ((png_int_32)(*((buf) + 3))))
2643 extern PNG_EXPORT(png_uint_32,png_get_uint_32) PNGARG((png_bytep buf));
2644 extern PNG_EXPORT(png_uint_16,png_get_uint_16) PNGARG((png_bytep buf));
2645 #ifdef PNG_GET_INT_32_SUPPORTED
2646 extern PNG_EXPORT(png_int_32,png_get_int_32) PNGARG((png_bytep buf));
2649 extern PNG_EXPORT(png_uint_32,png_get_uint_31)
2650 PNGARG((png_structp png_ptr, png_bytep buf));
2651 /* No png_get_int_16 -- may be added if there's a real need for it. */
2653 /* Place a 32-bit number into a buffer in PNG byte order (big-endian). */
2654 extern PNG_EXPORT(void,png_save_uint_32)
2655 PNGARG((png_bytep buf, png_uint_32 i));
2656 extern PNG_EXPORT(void,png_save_int_32)
2657 PNGARG((png_bytep buf, png_int_32 i));
2659 /* Place a 16-bit number into a buffer in PNG byte order.
2660 * The parameter is declared unsigned int, not png_uint_16,
2661 * just to avoid potential problems on pre-ANSI C compilers.
2663 extern PNG_EXPORT(void,png_save_uint_16)
2664 PNGARG((png_bytep buf, unsigned int i));
2665 /* No png_save_int_16 -- may be added if there's a real need for it. */
2667 /* ************************************************************************* */
2669 /* Various modes of operation. Note that after an init, mode is set to
2670 * zero automatically when the structure is created.
2672 #define PNG_HAVE_IHDR 0x01
2673 #define PNG_HAVE_PLTE 0x02
2674 #define PNG_HAVE_IDAT 0x04
2675 #define PNG_AFTER_IDAT 0x08 /* Have complete zlib datastream */
2676 #define PNG_HAVE_IEND 0x10
2677 #define PNG_HAVE_gAMA 0x20
2678 #define PNG_HAVE_cHRM 0x40
2684 #endif /* PNG_VERSION_INFO_ONLY */
2685 /* Do not put anything past this line */
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