2 /* png.h - header file for PNG reference library
4 * libpng version 1.4.3 - June 26, 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 1.4.3 - June 26, 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]
142 * 1.4.2beta01 14 10402 14.so.14.2[.0]
143 * 1.4.2rc02-06 14 10402 14.so.14.2[.0]
144 * 1.4.2 14 10402 14.so.14.2[.0]
145 * 1.4.3beta01-05 14 10403 14.so.14.3[.0]
146 * 1.4.3rc01-03 14 10403 14.so.14.3[.0]
147 * 1.4.3 14 10403 14.so.14.3[.0]
149 * Henceforth the source version will match the shared-library major
150 * and minor numbers; the shared-library major version number will be
151 * used for changes in backward compatibility, as it is intended. The
152 * PNG_LIBPNG_VER macro, which is not used within libpng but is available
153 * for applications, is an unsigned integer of the form xyyzz corresponding
154 * to the source version x.y.z (leading zeros in y and z). Beta versions
155 * were given the previous public release number plus a letter, until
156 * version 1.0.6j; from then on they were given the upcoming public
157 * release number plus "betaNN" or "rcN".
159 * Binary incompatibility exists only when applications make direct access
160 * to the info_ptr or png_ptr members through png.h, and the compiled
161 * application is loaded with a different version of the library.
163 * DLLNUM will change each time there are forward or backward changes
164 * in binary compatibility (e.g., when a new feature is added).
166 * See libpng.txt or libpng.3 for more information. The PNG specification
167 * is available as a W3C Recommendation and as an ISO Specification,
168 * <http://www.w3.org/TR/2003/REC-PNG-20031110/
172 * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
174 * If you modify libpng you may insert additional notices immediately following
177 * This code is released under the libpng license.
179 * libpng versions 1.2.6, August 15, 2004, through 1.4.3, June 26, 2010, are
180 * Copyright (c) 2004, 2006-2010 Glenn Randers-Pehrson, and are
181 * distributed according to the same disclaimer and license as libpng-1.2.5
182 * with the following individual added to the list of Contributing Authors:
186 * libpng versions 1.0.7, July 1, 2000, through 1.2.5, October 3, 2002, are
187 * Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are
188 * distributed according to the same disclaimer and license as libpng-1.0.6
189 * with the following individuals added to the list of Contributing Authors:
191 * Simon-Pierre Cadieux
195 * and with the following additions to the disclaimer:
197 * There is no warranty against interference with your enjoyment of the
198 * library or against infringement. There is no warranty that our
199 * efforts or the library will fulfill any of your particular purposes
200 * or needs. This library is provided with all faults, and the entire
201 * risk of satisfactory quality, performance, accuracy, and effort is with
204 * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
205 * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson, and are
206 * distributed according to the same disclaimer and license as libpng-0.96,
207 * with the following individuals added to the list of Contributing Authors:
210 * Glenn Randers-Pehrson
213 * libpng versions 0.89, June 1996, through 0.96, May 1997, are
214 * Copyright (c) 1996, 1997 Andreas Dilger
215 * Distributed according to the same disclaimer and license as libpng-0.88,
216 * with the following individuals added to the list of Contributing Authors:
225 * libpng versions 0.5, May 1995, through 0.88, January 1996, are
226 * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
228 * For the purposes of this copyright and license, "Contributing Authors"
229 * is defined as the following set of individuals:
237 * The PNG Reference Library is supplied "AS IS". The Contributing Authors
238 * and Group 42, Inc. disclaim all warranties, expressed or implied,
239 * including, without limitation, the warranties of merchantability and of
240 * fitness for any purpose. The Contributing Authors and Group 42, Inc.
241 * assume no liability for direct, indirect, incidental, special, exemplary,
242 * or consequential damages, which may result from the use of the PNG
243 * Reference Library, even if advised of the possibility of such damage.
245 * Permission is hereby granted to use, copy, modify, and distribute this
246 * source code, or portions hereof, for any purpose, without fee, subject
247 * to the following restrictions:
249 * 1. The origin of this source code must not be misrepresented.
251 * 2. Altered versions must be plainly marked as such and
252 * must not be misrepresented as being the original source.
254 * 3. This Copyright notice may not be removed or altered from
255 * any source or altered source distribution.
257 * The Contributing Authors and Group 42, Inc. specifically permit, without
258 * fee, and encourage the use of this source code as a component to
259 * supporting the PNG file format in commercial products. If you use this
260 * source code in a product, acknowledgment is not required but would be
265 * A "png_get_copyright" function is available, for convenient use in "about"
266 * boxes and the like:
268 * printf("%s",png_get_copyright(NULL));
270 * Also, the PNG logo (in PNG format, of course) is supplied in the
271 * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
275 * Libpng is OSI Certified Open Source Software. OSI Certified is a
276 * certification mark of the Open Source Initiative.
280 * The contributing authors would like to thank all those who helped
281 * with testing, bug fixes, and patience. This wouldn't have been
282 * possible without all of you.
284 * Thanks to Frank J. T. Wojcik for helping with the documentation.
288 * Y2K compliance in libpng:
289 * =========================
293 * Since the PNG Development group is an ad-hoc body, we can't make
294 * an official declaration.
296 * This is your unofficial assurance that libpng from version 0.71 and
297 * upward through 1.4.3 are Y2K compliant. It is my belief that earlier
298 * versions were also Y2K compliant.
300 * Libpng only has three year fields. One is a 2-byte unsigned integer
301 * that will hold years up to 65535. The other two hold the date in text
302 * format, and will hold years up to 9999.
305 * "png_uint_16 year" in png_time_struct.
308 * "png_charp time_buffer" in png_struct and
309 * "near_time_buffer", which is a local character string in png.c.
311 * There are seven time-related functions:
312 * png.c: png_convert_to_rfc_1123() in png.c
313 * (formerly png_convert_to_rfc_1152() in error)
314 * png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
315 * png_convert_from_time_t() in pngwrite.c
316 * png_get_tIME() in pngget.c
317 * png_handle_tIME() in pngrutil.c, called in pngread.c
318 * png_set_tIME() in pngset.c
319 * png_write_tIME() in pngwutil.c, called in pngwrite.c
321 * All handle dates properly in a Y2K environment. The
322 * png_convert_from_time_t() function calls gmtime() to convert from system
323 * clock time, which returns (year - 1900), which we properly convert to
324 * the full 4-digit year. There is a possibility that applications using
325 * libpng are not passing 4-digit years into the png_convert_to_rfc_1123()
326 * function, or that they are incorrectly passing only a 2-digit year
327 * instead of "year - 1900" into the png_convert_from_struct_tm() function,
328 * but this is not under our control. The libpng documentation has always
329 * stated that it works with 4-digit years, and the APIs have been
330 * documented as such.
332 * The tIME chunk itself is also Y2K compliant. It uses a 2-byte unsigned
333 * integer to hold the year, and can hold years as large as 65535.
335 * zlib, upon which libpng depends, is also Y2K compliant. It contains
336 * no date-related code.
338 * Glenn Randers-Pehrson
340 * PNG Development Group
346 /* This is not the place to learn how to use libpng. The file libpng.txt
347 * describes how to use libpng, and the file example.c summarizes it
348 * with some code on which to build. This file is useful for looking
349 * at the actual function definitions and structure components.
352 /* Version information for png.h - this should match the version in png.c */
353 #define PNG_LIBPNG_VER_STRING "1.4.3"
354 #define PNG_HEADER_VERSION_STRING \
355 " libpng version 1.4.3 - June 26, 2010\n"
357 #define PNG_LIBPNG_VER_SONUM 14
358 #define PNG_LIBPNG_VER_DLLNUM 14
360 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
361 #define PNG_LIBPNG_VER_MAJOR 1
362 #define PNG_LIBPNG_VER_MINOR 4
363 #define PNG_LIBPNG_VER_RELEASE 3
364 /* This should match the numeric part of the final component of
365 * PNG_LIBPNG_VER_STRING, omitting any leading zero:
368 #define PNG_LIBPNG_VER_BUILD 0
371 #define PNG_LIBPNG_BUILD_ALPHA 1
372 #define PNG_LIBPNG_BUILD_BETA 2
373 #define PNG_LIBPNG_BUILD_RC 3
374 #define PNG_LIBPNG_BUILD_STABLE 4
375 #define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7
377 /* Release-Specific Flags */
378 #define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with
379 PNG_LIBPNG_BUILD_STABLE only */
380 #define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with
381 PNG_LIBPNG_BUILD_SPECIAL */
382 #define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with
383 PNG_LIBPNG_BUILD_PRIVATE */
385 #define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_BETA
387 /* Careful here. At one time, Guy wanted to use 082, but that would be octal.
388 * We must not include leading zeros.
389 * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only
390 * version 1.0.0 was mis-numbered 100 instead of 10000). From
391 * version 1.0.1 it's xxyyzz, where x=major, y=minor, z=release
393 #define PNG_LIBPNG_VER 10403 /* 1.4.3 */
395 #ifndef PNG_VERSION_INFO_ONLY
396 /* Include the compression library's header */
400 /* Include all user configurable info, including optional assembler routines */
404 * Added at libpng-1.2.8
406 * Ref MSDN: Private as priority over Special
407 * VS_FF_PRIVATEBUILD File *was not* built using standard release
408 * procedures. If this value is given, the StringFileInfo block must
409 * contain a PrivateBuild string.
411 * VS_FF_SPECIALBUILD File *was* built by the original company using
412 * standard release procedures but is a variation of the standard
413 * file of the same version number. If this value is given, the
414 * StringFileInfo block must contain a SpecialBuild string.
417 #ifdef PNG_USER_PRIVATEBUILD
418 # define PNG_LIBPNG_BUILD_TYPE \
419 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE)
421 # ifdef PNG_LIBPNG_SPECIALBUILD
422 # define PNG_LIBPNG_BUILD_TYPE \
423 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL)
425 # define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE)
429 #ifndef PNG_VERSION_INFO_ONLY
431 /* Inhibit C++ name-mangling for libpng functions but not for system calls. */
434 #endif /* __cplusplus */
436 /* This file is arranged in several sections. The first section contains
437 * structure and type definitions. The second section contains the external
438 * library functions, while the third has the internal library functions,
439 * which applications aren't expected to use directly.
442 /* Variables declared in png.c - only it needs to define PNG_NO_EXTERN */
443 #if !defined(PNG_NO_EXTERN) || defined(PNG_ALWAYS_EXTERN)
444 /* Version information for C files, stored in png.c. This had better match
447 #define png_libpng_ver png_get_header_ver(NULL)
449 #endif /* PNG_NO_EXTERN */
451 /* Three color definitions. The order of the red, green, and blue, (and the
452 * exact size) is not important, although the size of the fields need to
453 * be png_byte or png_uint_16 (as defined below).
455 typedef struct png_color_struct
461 typedef png_color FAR
* png_colorp
;
462 typedef png_color FAR
* FAR
* png_colorpp
;
464 typedef struct png_color_16_struct
466 png_byte index
; /* used for palette files */
467 png_uint_16 red
; /* for use in red green blue files */
470 png_uint_16 gray
; /* for use in grayscale files */
472 typedef png_color_16 FAR
* png_color_16p
;
473 typedef png_color_16 FAR
* FAR
* png_color_16pp
;
475 typedef struct png_color_8_struct
477 png_byte red
; /* for use in red green blue files */
480 png_byte gray
; /* for use in grayscale files */
481 png_byte alpha
; /* for alpha channel files */
483 typedef png_color_8 FAR
* png_color_8p
;
484 typedef png_color_8 FAR
* FAR
* png_color_8pp
;
487 * The following two structures are used for the in-core representation
490 typedef struct png_sPLT_entry_struct
496 png_uint_16 frequency
;
498 typedef png_sPLT_entry FAR
* png_sPLT_entryp
;
499 typedef png_sPLT_entry FAR
* FAR
* png_sPLT_entrypp
;
501 /* When the depth of the sPLT palette is 8 bits, the color and alpha samples
502 * occupy the LSB of their respective members, and the MSB of each member
503 * is zero-filled. The frequency member always occupies the full 16 bits.
506 typedef struct png_sPLT_struct
508 png_charp name
; /* palette name */
509 png_byte depth
; /* depth of palette samples */
510 png_sPLT_entryp entries
; /* palette entries */
511 png_int_32 nentries
; /* number of palette entries */
513 typedef png_sPLT_t FAR
* png_sPLT_tp
;
514 typedef png_sPLT_t FAR
* FAR
* png_sPLT_tpp
;
516 #ifdef PNG_TEXT_SUPPORTED
517 /* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,
518 * and whether that contents is compressed or not. The "key" field
519 * points to a regular zero-terminated C string. The "text", "lang", and
520 * "lang_key" fields can be regular C strings, empty strings, or NULL pointers.
521 * However, the * structure returned by png_get_text() will always contain
522 * regular zero-terminated C strings (possibly empty), never NULL pointers,
523 * so they can be safely used in printf() and other string-handling functions.
525 typedef struct png_text_struct
527 int compression
; /* compression value:
532 png_charp key
; /* keyword, 1-79 character description of "text" */
533 png_charp text
; /* comment, may be an empty string (ie "")
535 png_size_t text_length
; /* length of the text string */
536 #ifdef PNG_iTXt_SUPPORTED
537 png_size_t itxt_length
; /* length of the itxt string */
538 png_charp lang
; /* language code, 0-79 characters
540 png_charp lang_key
; /* keyword translated UTF-8 string, 0 or more
541 chars or a NULL pointer */
544 typedef png_text FAR
* png_textp
;
545 typedef png_text FAR
* FAR
* png_textpp
;
548 /* Supported compression types for text in PNG files (tEXt, and zTXt).
549 * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */
550 #define PNG_TEXT_COMPRESSION_NONE_WR -3
551 #define PNG_TEXT_COMPRESSION_zTXt_WR -2
552 #define PNG_TEXT_COMPRESSION_NONE -1
553 #define PNG_TEXT_COMPRESSION_zTXt 0
554 #define PNG_ITXT_COMPRESSION_NONE 1
555 #define PNG_ITXT_COMPRESSION_zTXt 2
556 #define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */
558 /* png_time is a way to hold the time in an machine independent way.
559 * Two conversions are provided, both from time_t and struct tm. There
560 * is no portable way to convert to either of these structures, as far
561 * as I know. If you know of a portable way, send it to me. As a side
562 * note - PNG has always been Year 2000 compliant!
564 typedef struct png_time_struct
566 png_uint_16 year
; /* full year, as in, 1995 */
567 png_byte month
; /* month of year, 1 - 12 */
568 png_byte day
; /* day of month, 1 - 31 */
569 png_byte hour
; /* hour of day, 0 - 23 */
570 png_byte minute
; /* minute of hour, 0 - 59 */
571 png_byte second
; /* second of minute, 0 - 60 (for leap seconds) */
573 typedef png_time FAR
* png_timep
;
574 typedef png_time FAR
* FAR
* png_timepp
;
576 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) || \
577 defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
578 /* png_unknown_chunk is a structure to hold queued chunks for which there is
579 * no specific support. The idea is that we can use this to queue
580 * up private chunks for output even though the library doesn't actually
581 * know about their semantics.
583 typedef struct png_unknown_chunk_t
589 /* libpng-using applications should NOT directly modify this byte. */
590 png_byte location
; /* mode of operation at read time */
593 typedef png_unknown_chunk FAR
* png_unknown_chunkp
;
594 typedef png_unknown_chunk FAR
* FAR
* png_unknown_chunkpp
;
597 /* png_info is a structure that holds the information in a PNG file so
598 * that the application can find out the characteristics of the image.
599 * If you are reading the file, this structure will tell you what is
600 * in the PNG file. If you are writing the file, fill in the information
601 * you want to put into the PNG file, then call png_write_info().
602 * The names chosen should be very close to the PNG specification, so
603 * consult that document for information about the meaning of each field.
605 * With libpng < 0.95, it was only possible to directly set and read the
606 * the values in the png_info_struct, which meant that the contents and
607 * order of the values had to remain fixed. With libpng 0.95 and later,
608 * however, there are now functions that abstract the contents of
609 * png_info_struct from the application, so this makes it easier to use
610 * libpng with dynamic libraries, and even makes it possible to use
611 * libraries that don't have all of the libpng ancillary chunk-handing
614 * In any case, the order of the parameters in png_info_struct should NOT
615 * be changed for as long as possible to keep compatibility with applications
616 * that use the old direct-access method with png_info_struct.
618 * The following members may have allocated storage attached that should be
619 * cleaned up before the structure is discarded: palette, trans, text,
620 * pcal_purpose, pcal_units, pcal_params, hist, iccp_name, iccp_profile,
621 * splt_palettes, scal_unit, row_pointers, and unknowns. By default, these
622 * are automatically freed when the info structure is deallocated, if they were
623 * allocated internally by libpng. This behavior can be changed by means
624 * of the png_data_freer() function.
626 * More allocation details: all the chunk-reading functions that
627 * change these members go through the corresponding png_set_*
628 * functions. A function to clear these members is available: see
629 * png_free_data(). The png_set_* functions do not depend on being
630 * able to point info structure members to any of the storage they are
631 * passed (they make their own copies), EXCEPT that the png_set_text
632 * functions use the same storage passed to them in the text_ptr or
633 * itxt_ptr structure argument, and the png_set_rows and png_set_unknowns
634 * functions do not make their own copies.
636 typedef struct png_info_struct
638 /* the following are necessary for every PNG file */
639 png_uint_32 width PNG_DEPSTRUCT
; /* width of image in pixels (from IHDR) */
640 png_uint_32 height PNG_DEPSTRUCT
; /* height of image in pixels (from IHDR) */
641 png_uint_32 valid PNG_DEPSTRUCT
; /* valid chunk data (see PNG_INFO_
643 png_size_t rowbytes PNG_DEPSTRUCT
; /* bytes needed to hold an untransformed
645 png_colorp palette PNG_DEPSTRUCT
; /* array of color values
646 (valid & PNG_INFO_PLTE) */
647 png_uint_16 num_palette PNG_DEPSTRUCT
; /* number of color entries in
649 png_uint_16 num_trans PNG_DEPSTRUCT
; /* number of transparent palette
651 png_byte bit_depth PNG_DEPSTRUCT
; /* 1, 2, 4, 8, or 16 bits/channel
653 png_byte color_type PNG_DEPSTRUCT
; /* see PNG_COLOR_TYPE_ below
655 /* The following three should have been named *_method not *_type */
656 png_byte compression_type PNG_DEPSTRUCT
; /* must be
657 PNG_COMPRESSION_TYPE_BASE (IHDR) */
658 png_byte filter_type PNG_DEPSTRUCT
; /* must be PNG_FILTER_TYPE_BASE
660 png_byte interlace_type PNG_DEPSTRUCT
; /* One of PNG_INTERLACE_NONE,
661 PNG_INTERLACE_ADAM7 */
663 /* The following is informational only on read, and not used on writes. */
664 png_byte channels PNG_DEPSTRUCT
; /* number of data channels per
665 pixel (1, 2, 3, 4) */
666 png_byte pixel_depth PNG_DEPSTRUCT
; /* number of bits per pixel */
667 png_byte spare_byte PNG_DEPSTRUCT
; /* to align the data, and for
669 png_byte signature
[8] PNG_DEPSTRUCT
; /* magic bytes read by libpng
670 from start of file */
672 /* The rest of the data is optional. If you are reading, check the
673 * valid field to see if the information in these are valid. If you
674 * are writing, set the valid field to those chunks you want written,
675 * and initialize the appropriate fields below.
678 #if defined(PNG_gAMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
679 /* The gAMA chunk describes the gamma characteristics of the system
680 * on which the image was created, normally in the range [1.0, 2.5].
681 * Data is valid if (valid & PNG_INFO_gAMA) is non-zero.
683 float gamma PNG_DEPSTRUCT
; /* gamma value of image,
684 if (valid & PNG_INFO_gAMA) */
687 #ifdef PNG_sRGB_SUPPORTED
689 /* Data valid if (valid & PNG_INFO_sRGB) non-zero. */
690 png_byte srgb_intent PNG_DEPSTRUCT
; /* sRGB rendering intent
694 #ifdef PNG_TEXT_SUPPORTED
695 /* The tEXt, and zTXt chunks contain human-readable textual data in
696 * uncompressed, compressed, and optionally compressed forms, respectively.
697 * The data in "text" is an array of pointers to uncompressed,
698 * null-terminated C strings. Each chunk has a keyword that describes the
699 * textual data contained in that chunk. Keywords are not required to be
700 * unique, and the text string may be empty. Any number of text chunks may
703 int num_text PNG_DEPSTRUCT
; /* number of comments read/to write */
704 int max_text PNG_DEPSTRUCT
; /* current size of text array */
705 png_textp text PNG_DEPSTRUCT
; /* array of comments read/to write */
706 #endif /* PNG_TEXT_SUPPORTED */
708 #ifdef PNG_tIME_SUPPORTED
709 /* The tIME chunk holds the last time the displayed image data was
710 * modified. See the png_time struct for the contents of this struct.
712 png_time mod_time PNG_DEPSTRUCT
;
715 #ifdef PNG_sBIT_SUPPORTED
716 /* The sBIT chunk specifies the number of significant high-order bits
717 * in the pixel data. Values are in the range [1, bit_depth], and are
718 * only specified for the channels in the pixel data. The contents of
719 * the low-order bits is not specified. Data is valid if
720 * (valid & PNG_INFO_sBIT) is non-zero.
722 png_color_8 sig_bit PNG_DEPSTRUCT
; /* significant bits in color channels */
725 #if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_EXPAND_SUPPORTED) || \
726 defined(PNG_READ_BACKGROUND_SUPPORTED)
727 /* The tRNS chunk supplies transparency data for paletted images and
728 * other image types that don't need a full alpha channel. There are
729 * "num_trans" transparency values for a paletted image, stored in the
730 * same order as the palette colors, starting from index 0. Values
731 * for the data are in the range [0, 255], ranging from fully transparent
732 * to fully opaque, respectively. For non-paletted images, there is a
733 * single color specified that should be treated as fully transparent.
734 * Data is valid if (valid & PNG_INFO_tRNS) is non-zero.
736 png_bytep trans_alpha PNG_DEPSTRUCT
; /* alpha values for paletted
738 png_color_16 trans_color PNG_DEPSTRUCT
; /* transparent color for
742 #if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
743 /* The bKGD chunk gives the suggested image background color if the
744 * display program does not have its own background color and the image
745 * is needs to composited onto a background before display. The colors
746 * in "background" are normally in the same color space/depth as the
747 * pixel data. Data is valid if (valid & PNG_INFO_bKGD) is non-zero.
749 png_color_16 background PNG_DEPSTRUCT
;
752 #ifdef PNG_oFFs_SUPPORTED
753 /* The oFFs chunk gives the offset in "offset_unit_type" units rightwards
754 * and downwards from the top-left corner of the display, page, or other
755 * application-specific co-ordinate space. See the PNG_OFFSET_ defines
756 * below for the unit types. Valid if (valid & PNG_INFO_oFFs) non-zero.
758 png_int_32 x_offset PNG_DEPSTRUCT
; /* x offset on page */
759 png_int_32 y_offset PNG_DEPSTRUCT
; /* y offset on page */
760 png_byte offset_unit_type PNG_DEPSTRUCT
; /* offset units type */
763 #ifdef PNG_pHYs_SUPPORTED
764 /* The pHYs chunk gives the physical pixel density of the image for
765 * display or printing in "phys_unit_type" units (see PNG_RESOLUTION_
766 * defines below). Data is valid if (valid & PNG_INFO_pHYs) is non-zero.
768 png_uint_32 x_pixels_per_unit PNG_DEPSTRUCT
; /* horizontal pixel density */
769 png_uint_32 y_pixels_per_unit PNG_DEPSTRUCT
; /* vertical pixel density */
770 png_byte phys_unit_type PNG_DEPSTRUCT
; /* resolution type (see
771 PNG_RESOLUTION_ below) */
774 #ifdef PNG_hIST_SUPPORTED
775 /* The hIST chunk contains the relative frequency or importance of the
776 * various palette entries, so that a viewer can intelligently select a
777 * reduced-color palette, if required. Data is an array of "num_palette"
778 * values in the range [0,65535]. Data valid if (valid & PNG_INFO_hIST)
781 png_uint_16p hist PNG_DEPSTRUCT
;
784 #ifdef PNG_cHRM_SUPPORTED
785 /* The cHRM chunk describes the CIE color characteristics of the monitor
786 * on which the PNG was created. This data allows the viewer to do gamut
787 * mapping of the input image to ensure that the viewer sees the same
788 * colors in the image as the creator. Values are in the range
789 * [0.0, 0.8]. Data valid if (valid & PNG_INFO_cHRM) non-zero.
791 #ifdef PNG_FLOATING_POINT_SUPPORTED
792 float x_white PNG_DEPSTRUCT
;
793 float y_white PNG_DEPSTRUCT
;
794 float x_red PNG_DEPSTRUCT
;
795 float y_red PNG_DEPSTRUCT
;
796 float x_green PNG_DEPSTRUCT
;
797 float y_green PNG_DEPSTRUCT
;
798 float x_blue PNG_DEPSTRUCT
;
799 float y_blue PNG_DEPSTRUCT
;
803 #ifdef PNG_pCAL_SUPPORTED
804 /* The pCAL chunk describes a transformation between the stored pixel
805 * values and original physical data values used to create the image.
806 * The integer range [0, 2^bit_depth - 1] maps to the floating-point
807 * range given by [pcal_X0, pcal_X1], and are further transformed by a
808 * (possibly non-linear) transformation function given by "pcal_type"
809 * and "pcal_params" into "pcal_units". Please see the PNG_EQUATION_
810 * defines below, and the PNG-Group's PNG extensions document for a
811 * complete description of the transformations and how they should be
812 * implemented, and for a description of the ASCII parameter strings.
813 * Data values are valid if (valid & PNG_INFO_pCAL) non-zero.
815 png_charp pcal_purpose PNG_DEPSTRUCT
; /* pCAL chunk description string */
816 png_int_32 pcal_X0 PNG_DEPSTRUCT
; /* minimum value */
817 png_int_32 pcal_X1 PNG_DEPSTRUCT
; /* maximum value */
818 png_charp pcal_units PNG_DEPSTRUCT
; /* Latin-1 string giving physical
820 png_charpp pcal_params PNG_DEPSTRUCT
; /* ASCII strings containing
822 png_byte pcal_type PNG_DEPSTRUCT
; /* equation type
823 (see PNG_EQUATION_ below) */
824 png_byte pcal_nparams PNG_DEPSTRUCT
; /* number of parameters given
828 /* New members added in libpng-1.0.6 */
829 png_uint_32 free_me PNG_DEPSTRUCT
; /* flags items libpng is
830 responsible for freeing */
832 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) || \
833 defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
834 /* Storage for unknown chunks that the library doesn't recognize. */
835 png_unknown_chunkp unknown_chunks PNG_DEPSTRUCT
;
836 png_size_t unknown_chunks_num PNG_DEPSTRUCT
;
839 #ifdef PNG_iCCP_SUPPORTED
840 /* iCCP chunk data. */
841 png_charp iccp_name PNG_DEPSTRUCT
; /* profile name */
842 png_charp iccp_profile PNG_DEPSTRUCT
; /* International Color Consortium
844 /* Note to maintainer: should be png_bytep */
845 png_uint_32 iccp_proflen PNG_DEPSTRUCT
; /* ICC profile data length */
846 png_byte iccp_compression PNG_DEPSTRUCT
; /* Always zero */
849 #ifdef PNG_sPLT_SUPPORTED
850 /* Data on sPLT chunks (there may be more than one). */
851 png_sPLT_tp splt_palettes PNG_DEPSTRUCT
;
852 png_uint_32 splt_palettes_num PNG_DEPSTRUCT
;
855 #ifdef PNG_sCAL_SUPPORTED
856 /* The sCAL chunk describes the actual physical dimensions of the
857 * subject matter of the graphic. The chunk contains a unit specification
858 * a byte value, and two ASCII strings representing floating-point
859 * values. The values are width and height corresponsing to one pixel
860 * in the image. This external representation is converted to double
861 * here. Data values are valid if (valid & PNG_INFO_sCAL) is non-zero.
863 png_byte scal_unit PNG_DEPSTRUCT
; /* unit of physical scale */
864 #ifdef PNG_FLOATING_POINT_SUPPORTED
865 double scal_pixel_width PNG_DEPSTRUCT
; /* width of one pixel */
866 double scal_pixel_height PNG_DEPSTRUCT
; /* height of one pixel */
868 #ifdef PNG_FIXED_POINT_SUPPORTED
869 png_charp scal_s_width PNG_DEPSTRUCT
; /* string containing height */
870 png_charp scal_s_height PNG_DEPSTRUCT
; /* string containing width */
874 #ifdef PNG_INFO_IMAGE_SUPPORTED
875 /* Memory has been allocated if (valid & PNG_ALLOCATED_INFO_ROWS)
877 /* Data valid if (valid & PNG_INFO_IDAT) non-zero */
878 png_bytepp row_pointers PNG_DEPSTRUCT
; /* the image bits */
881 #if defined(PNG_FIXED_POINT_SUPPORTED) && defined(PNG_gAMA_SUPPORTED)
882 png_fixed_point int_gamma PNG_DEPSTRUCT
; /* gamma of image,
883 if (valid & PNG_INFO_gAMA) */
886 #if defined(PNG_cHRM_SUPPORTED) && defined(PNG_FIXED_POINT_SUPPORTED)
887 png_fixed_point int_x_white PNG_DEPSTRUCT
;
888 png_fixed_point int_y_white PNG_DEPSTRUCT
;
889 png_fixed_point int_x_red PNG_DEPSTRUCT
;
890 png_fixed_point int_y_red PNG_DEPSTRUCT
;
891 png_fixed_point int_x_green PNG_DEPSTRUCT
;
892 png_fixed_point int_y_green PNG_DEPSTRUCT
;
893 png_fixed_point int_x_blue PNG_DEPSTRUCT
;
894 png_fixed_point int_y_blue PNG_DEPSTRUCT
;
899 typedef png_info FAR
* png_infop
;
900 typedef png_info FAR
* FAR
* png_infopp
;
902 /* Maximum positive integer used in PNG is (2^31)-1 */
903 #define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL)
904 #define PNG_UINT_32_MAX ((png_uint_32)(-1))
905 #define PNG_SIZE_MAX ((png_size_t)(-1))
907 /* These describe the color_type field in png_info. */
908 /* color type masks */
909 #define PNG_COLOR_MASK_PALETTE 1
910 #define PNG_COLOR_MASK_COLOR 2
911 #define PNG_COLOR_MASK_ALPHA 4
913 /* color types. Note that not all combinations are legal */
914 #define PNG_COLOR_TYPE_GRAY 0
915 #define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
916 #define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR)
917 #define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
918 #define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
920 #define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA
921 #define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA
923 /* This is for compression type. PNG 1.0-1.2 only define the single type. */
924 #define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */
925 #define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE
927 /* This is for filter type. PNG 1.0-1.2 only define the single type. */
928 #define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */
929 #define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */
930 #define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE
932 /* These are for the interlacing type. These values should NOT be changed. */
933 #define PNG_INTERLACE_NONE 0 /* Non-interlaced image */
934 #define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */
935 #define PNG_INTERLACE_LAST 2 /* Not a valid value */
937 /* These are for the oFFs chunk. These values should NOT be changed. */
938 #define PNG_OFFSET_PIXEL 0 /* Offset in pixels */
939 #define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */
940 #define PNG_OFFSET_LAST 2 /* Not a valid value */
942 /* These are for the pCAL chunk. These values should NOT be changed. */
943 #define PNG_EQUATION_LINEAR 0 /* Linear transformation */
944 #define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */
945 #define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */
946 #define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */
947 #define PNG_EQUATION_LAST 4 /* Not a valid value */
949 /* These are for the sCAL chunk. These values should NOT be changed. */
950 #define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */
951 #define PNG_SCALE_METER 1 /* meters per pixel */
952 #define PNG_SCALE_RADIAN 2 /* radians per pixel */
953 #define PNG_SCALE_LAST 3 /* Not a valid value */
955 /* These are for the pHYs chunk. These values should NOT be changed. */
956 #define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */
957 #define PNG_RESOLUTION_METER 1 /* pixels/meter */
958 #define PNG_RESOLUTION_LAST 2 /* Not a valid value */
960 /* These are for the sRGB chunk. These values should NOT be changed. */
961 #define PNG_sRGB_INTENT_PERCEPTUAL 0
962 #define PNG_sRGB_INTENT_RELATIVE 1
963 #define PNG_sRGB_INTENT_SATURATION 2
964 #define PNG_sRGB_INTENT_ABSOLUTE 3
965 #define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */
967 /* This is for text chunks */
968 #define PNG_KEYWORD_MAX_LENGTH 79
970 /* Maximum number of entries in PLTE/sPLT/tRNS arrays */
971 #define PNG_MAX_PALETTE_LENGTH 256
973 /* These determine if an ancillary chunk's data has been successfully read
974 * from the PNG header, or if the application has filled in the corresponding
975 * data in the info_struct to be written into the output file. The values
976 * of the PNG_INFO_<chunk> defines should NOT be changed.
978 #define PNG_INFO_gAMA 0x0001
979 #define PNG_INFO_sBIT 0x0002
980 #define PNG_INFO_cHRM 0x0004
981 #define PNG_INFO_PLTE 0x0008
982 #define PNG_INFO_tRNS 0x0010
983 #define PNG_INFO_bKGD 0x0020
984 #define PNG_INFO_hIST 0x0040
985 #define PNG_INFO_pHYs 0x0080
986 #define PNG_INFO_oFFs 0x0100
987 #define PNG_INFO_tIME 0x0200
988 #define PNG_INFO_pCAL 0x0400
989 #define PNG_INFO_sRGB 0x0800 /* GR-P, 0.96a */
990 #define PNG_INFO_iCCP 0x1000 /* ESR, 1.0.6 */
991 #define PNG_INFO_sPLT 0x2000 /* ESR, 1.0.6 */
992 #define PNG_INFO_sCAL 0x4000 /* ESR, 1.0.6 */
993 #define PNG_INFO_IDAT 0x8000L /* ESR, 1.0.6 */
995 /* This is used for the transformation routines, as some of them
996 * change these values for the row. It also should enable using
997 * the routines for other purposes.
999 typedef struct png_row_info_struct
1001 png_uint_32 width
; /* width of row */
1002 png_size_t rowbytes
; /* number of bytes in row */
1003 png_byte color_type
; /* color type of row */
1004 png_byte bit_depth
; /* bit depth of row */
1005 png_byte channels
; /* number of channels (1, 2, 3, or 4) */
1006 png_byte pixel_depth
; /* bits per pixel (depth * channels) */
1009 typedef png_row_info FAR
* png_row_infop
;
1010 typedef png_row_info FAR
* FAR
* png_row_infopp
;
1012 /* These are the function types for the I/O functions and for the functions
1013 * that allow the user to override the default I/O functions with his or her
1014 * own. The png_error_ptr type should match that of user-supplied warning
1015 * and error functions, while the png_rw_ptr type should match that of the
1016 * user read/write data functions.
1018 typedef struct png_struct_def png_struct
;
1019 typedef png_struct FAR
* png_structp
;
1021 typedef void (PNGAPI
*png_error_ptr
) PNGARG((png_structp
, png_const_charp
));
1022 typedef void (PNGAPI
*png_rw_ptr
) PNGARG((png_structp
, png_bytep
, png_size_t
));
1023 typedef void (PNGAPI
*png_flush_ptr
) PNGARG((png_structp
));
1024 typedef void (PNGAPI
*png_read_status_ptr
) PNGARG((png_structp
, png_uint_32
,
1026 typedef void (PNGAPI
*png_write_status_ptr
) PNGARG((png_structp
, png_uint_32
,
1029 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1030 typedef void (PNGAPI
*png_progressive_info_ptr
) PNGARG((png_structp
,
1032 typedef void (PNGAPI
*png_progressive_end_ptr
) PNGARG((png_structp
, png_infop
));
1033 typedef void (PNGAPI
*png_progressive_row_ptr
) PNGARG((png_structp
, png_bytep
,
1037 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
1038 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
1039 typedef void (PNGAPI
*png_user_transform_ptr
) PNGARG((png_structp
,
1040 png_row_infop
, png_bytep
));
1043 #ifdef PNG_USER_CHUNKS_SUPPORTED
1044 typedef int (PNGAPI
*png_user_chunk_ptr
) PNGARG((png_structp
,
1045 png_unknown_chunkp
));
1047 #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
1048 typedef void (PNGAPI
*png_unknown_chunk_ptr
) PNGARG((png_structp
));
1050 #ifdef PNG_SETJMP_SUPPORTED
1051 /* This must match the function definition in <setjmp.h>, and the
1052 * application must include this before png.h to obtain the definition
1055 typedef void (PNGAPI
*png_longjmp_ptr
) PNGARG((jmp_buf, int));
1058 /* Transform masks for the high-level interface */
1059 #define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */
1060 #define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */
1061 #define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */
1062 #define PNG_TRANSFORM_PACKING 0x0004 /* read and write */
1063 #define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */
1064 #define PNG_TRANSFORM_EXPAND 0x0010 /* read only */
1065 #define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */
1066 #define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */
1067 #define PNG_TRANSFORM_BGR 0x0080 /* read and write */
1068 #define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */
1069 #define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */
1070 #define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */
1071 #define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* write only */
1072 /* Added to libpng-1.2.34 */
1073 #define PNG_TRANSFORM_STRIP_FILLER_BEFORE PNG_TRANSFORM_STRIP_FILLER
1074 #define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */
1075 /* Added to libpng-1.4.0 */
1076 #define PNG_TRANSFORM_GRAY_TO_RGB 0x2000 /* read only */
1078 /* Flags for MNG supported features */
1079 #define PNG_FLAG_MNG_EMPTY_PLTE 0x01
1080 #define PNG_FLAG_MNG_FILTER_64 0x04
1081 #define PNG_ALL_MNG_FEATURES 0x05
1083 typedef png_voidp (*png_malloc_ptr
) PNGARG((png_structp
, png_alloc_size_t
));
1084 typedef void (*png_free_ptr
) PNGARG((png_structp
, png_voidp
));
1086 /* The structure that holds the information to read and write PNG files.
1087 * The only people who need to care about what is inside of this are the
1088 * people who will be modifying the library for their own special needs.
1089 * It should NOT be accessed directly by an application, except to store
1093 struct png_struct_def
1095 #ifdef PNG_SETJMP_SUPPORTED
1096 jmp_buf jmpbuf PNG_DEPSTRUCT
; /* used in png_error */
1097 png_longjmp_ptr longjmp_fn PNG_DEPSTRUCT
;/* setjmp non-local goto
1100 png_error_ptr error_fn PNG_DEPSTRUCT
; /* function for printing
1101 errors and aborting */
1102 png_error_ptr warning_fn PNG_DEPSTRUCT
; /* function for printing
1104 png_voidp error_ptr PNG_DEPSTRUCT
; /* user supplied struct for
1106 png_rw_ptr write_data_fn PNG_DEPSTRUCT
; /* function for writing
1108 png_rw_ptr read_data_fn PNG_DEPSTRUCT
; /* function for reading
1110 png_voidp io_ptr PNG_DEPSTRUCT
; /* ptr to application struct
1111 for I/O functions */
1113 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
1114 png_user_transform_ptr read_user_transform_fn PNG_DEPSTRUCT
; /* user read
1118 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
1119 png_user_transform_ptr write_user_transform_fn PNG_DEPSTRUCT
; /* user write
1123 /* These were added in libpng-1.0.2 */
1124 #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
1125 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
1126 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
1127 png_voidp user_transform_ptr PNG_DEPSTRUCT
; /* user supplied struct
1128 for user transform */
1129 png_byte user_transform_depth PNG_DEPSTRUCT
; /* bit depth of user
1130 transformed pixels */
1131 png_byte user_transform_channels PNG_DEPSTRUCT
; /* channels in user
1132 transformed pixels */
1136 png_uint_32 mode PNG_DEPSTRUCT
; /* tells us where we are in
1138 png_uint_32 flags PNG_DEPSTRUCT
; /* flags indicating various
1140 png_uint_32 transformations PNG_DEPSTRUCT
; /* which transformations
1143 z_stream zstream PNG_DEPSTRUCT
; /* pointer to decompression
1144 structure (below) */
1145 png_bytep zbuf PNG_DEPSTRUCT
; /* buffer for zlib */
1146 png_size_t zbuf_size PNG_DEPSTRUCT
; /* size of zbuf */
1147 int zlib_level PNG_DEPSTRUCT
; /* holds zlib compression level */
1148 int zlib_method PNG_DEPSTRUCT
; /* holds zlib compression method */
1149 int zlib_window_bits PNG_DEPSTRUCT
; /* holds zlib compression window
1151 int zlib_mem_level PNG_DEPSTRUCT
; /* holds zlib compression memory
1153 int zlib_strategy PNG_DEPSTRUCT
; /* holds zlib compression
1156 png_uint_32 width PNG_DEPSTRUCT
; /* width of image in pixels */
1157 png_uint_32 height PNG_DEPSTRUCT
; /* height of image in pixels */
1158 png_uint_32 num_rows PNG_DEPSTRUCT
; /* number of rows in current pass */
1159 png_uint_32 usr_width PNG_DEPSTRUCT
; /* width of row at start of write */
1160 png_size_t rowbytes PNG_DEPSTRUCT
; /* size of row in bytes */
1161 #if 0 /* Replaced with the following in libpng-1.4.1 */
1162 png_size_t irowbytes PNG_DEPSTRUCT
;
1164 /* Added in libpng-1.4.1 */
1165 #ifdef PNG_USER_LIMITS_SUPPORTED
1166 /* Total memory that a zTXt, sPLT, iTXt, iCCP, or unknown chunk
1167 * can occupy when decompressed. 0 means unlimited.
1168 * We will change the typedef from png_size_t to png_alloc_size_t
1171 png_alloc_size_t user_chunk_malloc_max PNG_DEPSTRUCT
;
1173 png_uint_32 iwidth PNG_DEPSTRUCT
; /* width of current interlaced
1175 png_uint_32 row_number PNG_DEPSTRUCT
; /* current row in interlace pass */
1176 png_bytep prev_row PNG_DEPSTRUCT
; /* buffer to save previous
1178 png_bytep row_buf PNG_DEPSTRUCT
; /* buffer to save current
1180 png_bytep sub_row PNG_DEPSTRUCT
; /* buffer to save "sub" row
1182 png_bytep up_row PNG_DEPSTRUCT
; /* buffer to save "up" row
1184 png_bytep avg_row PNG_DEPSTRUCT
; /* buffer to save "avg" row
1186 png_bytep paeth_row PNG_DEPSTRUCT
; /* buffer to save "Paeth" row
1188 png_row_info row_info PNG_DEPSTRUCT
; /* used for transformation
1191 png_uint_32 idat_size PNG_DEPSTRUCT
; /* current IDAT size for read */
1192 png_uint_32 crc PNG_DEPSTRUCT
; /* current chunk CRC value */
1193 png_colorp palette PNG_DEPSTRUCT
; /* palette from the input file */
1194 png_uint_16 num_palette PNG_DEPSTRUCT
; /* number of color entries in
1196 png_uint_16 num_trans PNG_DEPSTRUCT
; /* number of transparency values */
1197 png_byte chunk_name
[5] PNG_DEPSTRUCT
; /* null-terminated name of current
1199 png_byte compression PNG_DEPSTRUCT
; /* file compression type
1201 png_byte filter PNG_DEPSTRUCT
; /* file filter type (always 0) */
1202 png_byte interlaced PNG_DEPSTRUCT
; /* PNG_INTERLACE_NONE,
1203 PNG_INTERLACE_ADAM7 */
1204 png_byte pass PNG_DEPSTRUCT
; /* current interlace pass (0 - 6) */
1205 png_byte do_filter PNG_DEPSTRUCT
; /* row filter flags (see
1206 PNG_FILTER_ below ) */
1207 png_byte color_type PNG_DEPSTRUCT
; /* color type of file */
1208 png_byte bit_depth PNG_DEPSTRUCT
; /* bit depth of file */
1209 png_byte usr_bit_depth PNG_DEPSTRUCT
; /* bit depth of users row */
1210 png_byte pixel_depth PNG_DEPSTRUCT
; /* number of bits per pixel */
1211 png_byte channels PNG_DEPSTRUCT
; /* number of channels in file */
1212 png_byte usr_channels PNG_DEPSTRUCT
; /* channels at start of write */
1213 png_byte sig_bytes PNG_DEPSTRUCT
; /* magic bytes read/written from
1216 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
1217 png_uint_16 filler PNG_DEPSTRUCT
; /* filler bytes for pixel
1221 #ifdef PNG_bKGD_SUPPORTED
1222 png_byte background_gamma_type PNG_DEPSTRUCT
;
1223 # ifdef PNG_FLOATING_POINT_SUPPORTED
1224 float background_gamma PNG_DEPSTRUCT
;
1226 png_color_16 background PNG_DEPSTRUCT
; /* background color in
1227 screen gamma space */
1228 #ifdef PNG_READ_GAMMA_SUPPORTED
1229 png_color_16 background_1 PNG_DEPSTRUCT
; /* background normalized
1232 #endif /* PNG_bKGD_SUPPORTED */
1234 #ifdef PNG_WRITE_FLUSH_SUPPORTED
1235 png_flush_ptr output_flush_fn PNG_DEPSTRUCT
; /* Function for flushing
1237 png_uint_32 flush_dist PNG_DEPSTRUCT
; /* how many rows apart to flush,
1239 png_uint_32 flush_rows PNG_DEPSTRUCT
; /* number of rows written since
1243 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1244 int gamma_shift PNG_DEPSTRUCT
; /* number of "insignificant" bits
1246 #ifdef PNG_FLOATING_POINT_SUPPORTED
1247 float gamma PNG_DEPSTRUCT
; /* file gamma value */
1248 float screen_gamma PNG_DEPSTRUCT
; /* screen gamma value
1249 (display_exponent) */
1253 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1254 png_bytep gamma_table PNG_DEPSTRUCT
; /* gamma table for 8-bit
1256 png_bytep gamma_from_1 PNG_DEPSTRUCT
; /* converts from 1.0 to screen */
1257 png_bytep gamma_to_1 PNG_DEPSTRUCT
; /* converts from file to 1.0 */
1258 png_uint_16pp gamma_16_table PNG_DEPSTRUCT
; /* gamma table for 16-bit
1260 png_uint_16pp gamma_16_from_1 PNG_DEPSTRUCT
; /* converts from 1.0 to
1262 png_uint_16pp gamma_16_to_1 PNG_DEPSTRUCT
; /* converts from file to 1.0 */
1265 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_sBIT_SUPPORTED)
1266 png_color_8 sig_bit PNG_DEPSTRUCT
; /* significant bits in each
1267 available channel */
1270 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
1271 png_color_8 shift PNG_DEPSTRUCT
; /* shift for significant bit
1275 #if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \
1276 || defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1277 png_bytep trans_alpha PNG_DEPSTRUCT
; /* alpha values for
1279 png_color_16 trans_color PNG_DEPSTRUCT
; /* transparent color for
1280 non-paletted files */
1283 png_read_status_ptr read_row_fn PNG_DEPSTRUCT
; /* called after each
1285 png_write_status_ptr write_row_fn PNG_DEPSTRUCT
; /* called after each
1287 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1288 png_progressive_info_ptr info_fn PNG_DEPSTRUCT
; /* called after header
1290 png_progressive_row_ptr row_fn PNG_DEPSTRUCT
; /* called after each
1291 prog. row is decoded */
1292 png_progressive_end_ptr end_fn PNG_DEPSTRUCT
; /* called after image
1294 png_bytep save_buffer_ptr PNG_DEPSTRUCT
; /* current location in
1296 png_bytep save_buffer PNG_DEPSTRUCT
; /* buffer for previously
1298 png_bytep current_buffer_ptr PNG_DEPSTRUCT
; /* current location in
1300 png_bytep current_buffer PNG_DEPSTRUCT
; /* buffer for recently
1302 png_uint_32 push_length PNG_DEPSTRUCT
; /* size of current input
1304 png_uint_32 skip_length PNG_DEPSTRUCT
; /* bytes to skip in
1306 png_size_t save_buffer_size PNG_DEPSTRUCT
; /* amount of data now
1308 png_size_t save_buffer_max PNG_DEPSTRUCT
; /* total size of
1310 png_size_t buffer_size PNG_DEPSTRUCT
; /* total amount of
1311 available input data */
1312 png_size_t current_buffer_size PNG_DEPSTRUCT
; /* amount of data now
1313 in current_buffer */
1314 int process_mode PNG_DEPSTRUCT
; /* what push library
1315 is currently doing */
1316 int cur_palette PNG_DEPSTRUCT
; /* current push library
1319 # ifdef PNG_TEXT_SUPPORTED
1320 png_size_t current_text_size PNG_DEPSTRUCT
; /* current size of
1322 png_size_t current_text_left PNG_DEPSTRUCT
; /* how much text left
1324 png_charp current_text PNG_DEPSTRUCT
; /* current text chunk
1326 png_charp current_text_ptr PNG_DEPSTRUCT
; /* current location
1328 # endif /* PNG_PROGRESSIVE_READ_SUPPORTED && PNG_TEXT_SUPPORTED */
1330 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
1332 #if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
1333 /* For the Borland special 64K segment handler */
1334 png_bytepp offset_table_ptr PNG_DEPSTRUCT
;
1335 png_bytep offset_table PNG_DEPSTRUCT
;
1336 png_uint_16 offset_table_number PNG_DEPSTRUCT
;
1337 png_uint_16 offset_table_count PNG_DEPSTRUCT
;
1338 png_uint_16 offset_table_count_free PNG_DEPSTRUCT
;
1341 #ifdef PNG_READ_QUANTIZE_SUPPORTED
1342 png_bytep palette_lookup PNG_DEPSTRUCT
; /* lookup table for quantizing */
1343 png_bytep quantize_index PNG_DEPSTRUCT
; /* index translation for palette
1347 #if defined(PNG_READ_QUANTIZE_SUPPORTED) || defined(PNG_hIST_SUPPORTED)
1348 png_uint_16p hist PNG_DEPSTRUCT
; /* histogram */
1351 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
1352 png_byte heuristic_method PNG_DEPSTRUCT
; /* heuristic for row
1354 png_byte num_prev_filters PNG_DEPSTRUCT
; /* number of weights
1355 for previous rows */
1356 png_bytep prev_filters PNG_DEPSTRUCT
; /* filter type(s) of
1358 png_uint_16p filter_weights PNG_DEPSTRUCT
; /* weight(s) for previous
1360 png_uint_16p inv_filter_weights PNG_DEPSTRUCT
; /* 1/weight(s) for
1362 png_uint_16p filter_costs PNG_DEPSTRUCT
; /* relative filter
1364 png_uint_16p inv_filter_costs PNG_DEPSTRUCT
; /* 1/relative filter
1368 #ifdef PNG_TIME_RFC1123_SUPPORTED
1369 png_charp time_buffer PNG_DEPSTRUCT
; /* String to hold RFC 1123 time text */
1372 /* New members added in libpng-1.0.6 */
1374 png_uint_32 free_me PNG_DEPSTRUCT
; /* flags items libpng is
1375 responsible for freeing */
1377 #ifdef PNG_USER_CHUNKS_SUPPORTED
1378 png_voidp user_chunk_ptr PNG_DEPSTRUCT
;
1379 png_user_chunk_ptr read_user_chunk_fn PNG_DEPSTRUCT
; /* user read
1383 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
1384 int num_chunk_list PNG_DEPSTRUCT
;
1385 png_bytep chunk_list PNG_DEPSTRUCT
;
1388 /* New members added in libpng-1.0.3 */
1389 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1390 png_byte rgb_to_gray_status PNG_DEPSTRUCT
;
1391 /* These were changed from png_byte in libpng-1.0.6 */
1392 png_uint_16 rgb_to_gray_red_coeff PNG_DEPSTRUCT
;
1393 png_uint_16 rgb_to_gray_green_coeff PNG_DEPSTRUCT
;
1394 png_uint_16 rgb_to_gray_blue_coeff PNG_DEPSTRUCT
;
1397 /* New member added in libpng-1.0.4 (renamed in 1.0.9) */
1398 #if defined(PNG_MNG_FEATURES_SUPPORTED) || \
1399 defined(PNG_READ_EMPTY_PLTE_SUPPORTED) || \
1400 defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
1401 /* Changed from png_byte to png_uint_32 at version 1.2.0 */
1402 png_uint_32 mng_features_permitted PNG_DEPSTRUCT
;
1405 /* New member added in libpng-1.0.7 */
1406 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1407 png_fixed_point int_gamma PNG_DEPSTRUCT
;
1410 /* New member added in libpng-1.0.9, ifdef'ed out in 1.0.12, enabled in 1.2.0 */
1411 #ifdef PNG_MNG_FEATURES_SUPPORTED
1412 png_byte filter_type PNG_DEPSTRUCT
;
1415 /* New members added in libpng-1.2.0 */
1417 /* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */
1418 #ifdef PNG_USER_MEM_SUPPORTED
1419 png_voidp mem_ptr PNG_DEPSTRUCT
; /* user supplied struct for
1421 png_malloc_ptr malloc_fn PNG_DEPSTRUCT
; /* function for
1422 allocating memory */
1423 png_free_ptr free_fn PNG_DEPSTRUCT
; /* function for
1427 /* New member added in libpng-1.0.13 and 1.2.0 */
1428 png_bytep big_row_buf PNG_DEPSTRUCT
; /* buffer to save current
1431 #ifdef PNG_READ_QUANTIZE_SUPPORTED
1432 /* The following three members were added at version 1.0.14 and 1.2.4 */
1433 png_bytep quantize_sort PNG_DEPSTRUCT
; /* working sort array */
1434 png_bytep index_to_palette PNG_DEPSTRUCT
; /* where the original
1437 png_bytep palette_to_index PNG_DEPSTRUCT
; /* which original index
1442 /* New members added in libpng-1.0.16 and 1.2.6 */
1443 png_byte compression_type PNG_DEPSTRUCT
;
1445 #ifdef PNG_USER_LIMITS_SUPPORTED
1446 png_uint_32 user_width_max PNG_DEPSTRUCT
;
1447 png_uint_32 user_height_max PNG_DEPSTRUCT
;
1448 /* Added in libpng-1.4.0: Total number of sPLT, text, and unknown
1449 * chunks that can be stored (0 means unlimited).
1451 png_uint_32 user_chunk_cache_max PNG_DEPSTRUCT
;
1454 /* New member added in libpng-1.0.25 and 1.2.17 */
1455 #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
1456 /* Storage for unknown chunk that the library doesn't recognize. */
1457 png_unknown_chunk unknown_chunk PNG_DEPSTRUCT
;
1460 /* New members added in libpng-1.2.26 */
1461 png_uint_32 old_big_row_buf_size PNG_DEPSTRUCT
;
1462 png_uint_32 old_prev_row_size PNG_DEPSTRUCT
;
1464 /* New member added in libpng-1.2.30 */
1465 png_charp chunkdata PNG_DEPSTRUCT
; /* buffer for reading chunk data */
1467 #ifdef PNG_IO_STATE_SUPPORTED
1468 /* New member added in libpng-1.4.0 */
1469 png_uint_32 io_state PNG_DEPSTRUCT
;
1474 /* This triggers a compiler error in png.c, if png.c and png.h
1475 * do not agree upon the version number.
1477 typedef png_structp version_1_4_3
;
1479 typedef png_struct FAR
* FAR
* png_structpp
;
1481 /* Here are the function definitions most commonly used. This is not
1482 * the place to find out how to use libpng. See libpng.txt for the
1483 * full explanation, see example.c for the summary. This just provides
1484 * a simple one line description of the use of each function.
1487 /* Returns the version number of the library */
1488 extern PNG_EXPORT(png_uint_32
,png_access_version_number
) PNGARG((void));
1490 /* Tell lib we have already handled the first <num_bytes> magic bytes.
1491 * Handling more than 8 bytes from the beginning of the file is an error.
1493 extern PNG_EXPORT(void,png_set_sig_bytes
) PNGARG((png_structp png_ptr
,
1496 /* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
1497 * PNG file. Returns zero if the supplied bytes match the 8-byte PNG
1498 * signature, and non-zero otherwise. Having num_to_check == 0 or
1499 * start > 7 will always fail (ie return non-zero).
1501 extern PNG_EXPORT(int,png_sig_cmp
) PNGARG((png_bytep sig
, png_size_t start
,
1502 png_size_t num_to_check
));
1504 /* Simple signature checking function. This is the same as calling
1505 * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n).
1507 #define png_check_sig(sig,n) !png_sig_cmp((sig), 0, (n))
1509 /* Allocate and initialize png_ptr struct for reading, and any other memory. */
1510 extern PNG_EXPORT(png_structp
,png_create_read_struct
)
1511 PNGARG((png_const_charp user_png_ver
, png_voidp error_ptr
,
1512 png_error_ptr error_fn
, png_error_ptr warn_fn
)) PNG_ALLOCATED
;
1514 /* Allocate and initialize png_ptr struct for writing, and any other memory */
1515 extern PNG_EXPORT(png_structp
,png_create_write_struct
)
1516 PNGARG((png_const_charp user_png_ver
, png_voidp error_ptr
,
1517 png_error_ptr error_fn
, png_error_ptr warn_fn
)) PNG_ALLOCATED
;
1519 extern PNG_EXPORT(png_size_t
,png_get_compression_buffer_size
)
1520 PNGARG((png_structp png_ptr
));
1522 extern PNG_EXPORT(void,png_set_compression_buffer_size
)
1523 PNGARG((png_structp png_ptr
, png_size_t size
));
1525 /* Moved from pngconf.h in 1.4.0 and modified to ensure setjmp/longjmp
1528 #ifdef PNG_SETJMP_SUPPORTED
1529 /* This function returns the jmp_buf built in to *png_ptr. It must be
1530 * supplied with an appropriate 'longjmp' function to use on that jmp_buf
1531 * unless the default error function is overridden in which case NULL is
1532 * acceptable. The size of the jmp_buf is checked against the actual size
1533 * allocated by the library - the call will return NULL on a mismatch
1534 * indicating an ABI mismatch.
1536 extern PNG_EXPORT(jmp_buf*, png_set_longjmp_fn
)
1537 PNGARG((png_structp png_ptr
, png_longjmp_ptr longjmp_fn
, size_t
1539 # define png_jmpbuf(png_ptr) \
1540 (*png_set_longjmp_fn((png_ptr), longjmp, sizeof (jmp_buf)))
1542 # define png_jmpbuf(png_ptr) \
1543 (LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP)
1546 #ifdef PNG_READ_SUPPORTED
1547 /* Reset the compression stream */
1548 extern PNG_EXPORT(int,png_reset_zstream
) PNGARG((png_structp png_ptr
));
1551 /* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */
1552 #ifdef PNG_USER_MEM_SUPPORTED
1553 extern PNG_EXPORT(png_structp
,png_create_read_struct_2
)
1554 PNGARG((png_const_charp user_png_ver
, png_voidp error_ptr
,
1555 png_error_ptr error_fn
, png_error_ptr warn_fn
, png_voidp mem_ptr
,
1556 png_malloc_ptr malloc_fn
, png_free_ptr free_fn
)) PNG_ALLOCATED
;
1557 extern PNG_EXPORT(png_structp
,png_create_write_struct_2
)
1558 PNGARG((png_const_charp user_png_ver
, png_voidp error_ptr
,
1559 png_error_ptr error_fn
, png_error_ptr warn_fn
, png_voidp mem_ptr
,
1560 png_malloc_ptr malloc_fn
, png_free_ptr free_fn
)) PNG_ALLOCATED
;
1563 /* Write the PNG file signature. */
1564 extern PNG_EXPORT(void,png_write_sig
) PNGARG((png_structp png_ptr
));
1566 /* Write a PNG chunk - size, type, (optional) data, CRC. */
1567 extern PNG_EXPORT(void,png_write_chunk
) PNGARG((png_structp png_ptr
,
1568 png_bytep chunk_name
, png_bytep data
, png_size_t length
));
1570 /* Write the start of a PNG chunk - length and chunk name. */
1571 extern PNG_EXPORT(void,png_write_chunk_start
) PNGARG((png_structp png_ptr
,
1572 png_bytep chunk_name
, png_uint_32 length
));
1574 /* Write the data of a PNG chunk started with png_write_chunk_start(). */
1575 extern PNG_EXPORT(void,png_write_chunk_data
) PNGARG((png_structp png_ptr
,
1576 png_bytep data
, png_size_t length
));
1578 /* Finish a chunk started with png_write_chunk_start() (includes CRC). */
1579 extern PNG_EXPORT(void,png_write_chunk_end
) PNGARG((png_structp png_ptr
));
1581 /* Allocate and initialize the info structure */
1582 extern PNG_EXPORT(png_infop
,png_create_info_struct
)
1583 PNGARG((png_structp png_ptr
)) PNG_ALLOCATED
;
1585 extern PNG_EXPORT(void,png_info_init_3
) PNGARG((png_infopp info_ptr
,
1586 png_size_t png_info_struct_size
));
1588 /* Writes all the PNG information before the image. */
1589 extern PNG_EXPORT(void,png_write_info_before_PLTE
) PNGARG((png_structp png_ptr
,
1590 png_infop info_ptr
));
1591 extern PNG_EXPORT(void,png_write_info
) PNGARG((png_structp png_ptr
,
1592 png_infop info_ptr
));
1594 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1595 /* Read the information before the actual image data. */
1596 extern PNG_EXPORT(void,png_read_info
) PNGARG((png_structp png_ptr
,
1597 png_infop info_ptr
));
1600 #ifdef PNG_TIME_RFC1123_SUPPORTED
1601 extern PNG_EXPORT(png_charp
,png_convert_to_rfc1123
)
1602 PNGARG((png_structp png_ptr
, png_timep ptime
));
1605 #ifdef PNG_CONVERT_tIME_SUPPORTED
1606 /* Convert from a struct tm to png_time */
1607 extern PNG_EXPORT(void,png_convert_from_struct_tm
) PNGARG((png_timep ptime
,
1608 struct tm FAR
* ttime
));
1610 /* Convert from time_t to png_time. Uses gmtime() */
1611 extern PNG_EXPORT(void,png_convert_from_time_t
) PNGARG((png_timep ptime
,
1613 #endif /* PNG_CONVERT_tIME_SUPPORTED */
1615 #ifdef PNG_READ_EXPAND_SUPPORTED
1616 /* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
1617 extern PNG_EXPORT(void,png_set_expand
) PNGARG((png_structp png_ptr
));
1618 extern PNG_EXPORT(void,png_set_expand_gray_1_2_4_to_8
) PNGARG((png_structp
1620 extern PNG_EXPORT(void,png_set_palette_to_rgb
) PNGARG((png_structp png_ptr
));
1621 extern PNG_EXPORT(void,png_set_tRNS_to_alpha
) PNGARG((png_structp png_ptr
));
1624 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
1625 /* Use blue, green, red order for pixels. */
1626 extern PNG_EXPORT(void,png_set_bgr
) PNGARG((png_structp png_ptr
));
1629 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
1630 /* Expand the grayscale to 24-bit RGB if necessary. */
1631 extern PNG_EXPORT(void,png_set_gray_to_rgb
) PNGARG((png_structp png_ptr
));
1634 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1635 /* Reduce RGB to grayscale. */
1636 #ifdef PNG_FLOATING_POINT_SUPPORTED
1637 extern PNG_EXPORT(void,png_set_rgb_to_gray
) PNGARG((png_structp png_ptr
,
1638 int error_action
, double red
, double green
));
1640 extern PNG_EXPORT(void,png_set_rgb_to_gray_fixed
) PNGARG((png_structp png_ptr
,
1641 int error_action
, png_fixed_point red
, png_fixed_point green
));
1642 extern PNG_EXPORT(png_byte
,png_get_rgb_to_gray_status
) PNGARG((png_structp
1646 extern PNG_EXPORT(void,png_build_grayscale_palette
) PNGARG((int bit_depth
,
1647 png_colorp palette
));
1649 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
1650 extern PNG_EXPORT(void,png_set_strip_alpha
) PNGARG((png_structp png_ptr
));
1653 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
1654 defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
1655 extern PNG_EXPORT(void,png_set_swap_alpha
) PNGARG((png_structp png_ptr
));
1658 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
1659 defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
1660 extern PNG_EXPORT(void,png_set_invert_alpha
) PNGARG((png_structp png_ptr
));
1663 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
1664 /* Add a filler byte to 8-bit Gray or 24-bit RGB images. */
1665 extern PNG_EXPORT(void,png_set_filler
) PNGARG((png_structp png_ptr
,
1666 png_uint_32 filler
, int flags
));
1667 /* The values of the PNG_FILLER_ defines should NOT be changed */
1668 #define PNG_FILLER_BEFORE 0
1669 #define PNG_FILLER_AFTER 1
1670 /* Add an alpha byte to 8-bit Gray or 24-bit RGB images. */
1671 extern PNG_EXPORT(void,png_set_add_alpha
) PNGARG((png_structp png_ptr
,
1672 png_uint_32 filler
, int flags
));
1673 #endif /* PNG_READ_FILLER_SUPPORTED || PNG_WRITE_FILLER_SUPPORTED */
1675 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
1676 /* Swap bytes in 16-bit depth files. */
1677 extern PNG_EXPORT(void,png_set_swap
) PNGARG((png_structp png_ptr
));
1680 #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
1681 /* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
1682 extern PNG_EXPORT(void,png_set_packing
) PNGARG((png_structp png_ptr
));
1685 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
1686 defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1687 /* Swap packing order of pixels in bytes. */
1688 extern PNG_EXPORT(void,png_set_packswap
) PNGARG((png_structp png_ptr
));
1691 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
1692 /* Converts files to legal bit depths. */
1693 extern PNG_EXPORT(void,png_set_shift
) PNGARG((png_structp png_ptr
,
1694 png_color_8p true_bits
));
1697 #if defined(PNG_READ_INTERLACING_SUPPORTED) || \
1698 defined(PNG_WRITE_INTERLACING_SUPPORTED)
1699 /* Have the code handle the interlacing. Returns the number of passes. */
1700 extern PNG_EXPORT(int,png_set_interlace_handling
) PNGARG((png_structp png_ptr
));
1703 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
1704 /* Invert monochrome files */
1705 extern PNG_EXPORT(void,png_set_invert_mono
) PNGARG((png_structp png_ptr
));
1708 #ifdef PNG_READ_BACKGROUND_SUPPORTED
1709 /* Handle alpha and tRNS by replacing with a background color. */
1710 #ifdef PNG_FLOATING_POINT_SUPPORTED
1711 extern PNG_EXPORT(void,png_set_background
) PNGARG((png_structp png_ptr
,
1712 png_color_16p background_color
, int background_gamma_code
,
1713 int need_expand
, double background_gamma
));
1715 #define PNG_BACKGROUND_GAMMA_UNKNOWN 0
1716 #define PNG_BACKGROUND_GAMMA_SCREEN 1
1717 #define PNG_BACKGROUND_GAMMA_FILE 2
1718 #define PNG_BACKGROUND_GAMMA_UNIQUE 3
1721 #ifdef PNG_READ_16_TO_8_SUPPORTED
1722 /* Strip the second byte of information from a 16-bit depth file. */
1723 extern PNG_EXPORT(void,png_set_strip_16
) PNGARG((png_structp png_ptr
));
1726 #ifdef PNG_READ_QUANTIZE_SUPPORTED
1727 /* Turn on quantizing, and reduce the palette to the number of colors
1728 * available. Prior to libpng-1.4.2, this was png_set_dither().
1730 extern PNG_EXPORT(void,png_set_quantize
) PNGARG((png_structp png_ptr
,
1731 png_colorp palette
, int num_palette
, int maximum_colors
,
1732 png_uint_16p histogram
, int full_quantize
));
1734 /* This migration aid will be removed from libpng-1.5.0 */
1735 #define png_set_dither png_set_quantize
1737 #ifdef PNG_READ_GAMMA_SUPPORTED
1738 /* Handle gamma correction. Screen_gamma=(display_exponent) */
1739 #ifdef PNG_FLOATING_POINT_SUPPORTED
1740 extern PNG_EXPORT(void,png_set_gamma
) PNGARG((png_structp png_ptr
,
1741 double screen_gamma
, double default_file_gamma
));
1746 #ifdef PNG_WRITE_FLUSH_SUPPORTED
1747 /* Set how many lines between output flushes - 0 for no flushing */
1748 extern PNG_EXPORT(void,png_set_flush
) PNGARG((png_structp png_ptr
, int nrows
));
1749 /* Flush the current PNG output buffer */
1750 extern PNG_EXPORT(void,png_write_flush
) PNGARG((png_structp png_ptr
));
1753 /* Optional update palette with requested transformations */
1754 extern PNG_EXPORT(void,png_start_read_image
) PNGARG((png_structp png_ptr
));
1756 /* Optional call to update the users info structure */
1757 extern PNG_EXPORT(void,png_read_update_info
) PNGARG((png_structp png_ptr
,
1758 png_infop info_ptr
));
1760 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1761 /* Read one or more rows of image data. */
1762 extern PNG_EXPORT(void,png_read_rows
) PNGARG((png_structp png_ptr
,
1763 png_bytepp row
, png_bytepp display_row
, png_uint_32 num_rows
));
1766 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1767 /* Read a row of data. */
1768 extern PNG_EXPORT(void,png_read_row
) PNGARG((png_structp png_ptr
,
1770 png_bytep display_row
));
1773 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1774 /* Read the whole image into memory at once. */
1775 extern PNG_EXPORT(void,png_read_image
) PNGARG((png_structp png_ptr
,
1779 /* Write a row of image data */
1780 extern PNG_EXPORT(void,png_write_row
) PNGARG((png_structp png_ptr
,
1783 /* Write a few rows of image data */
1784 extern PNG_EXPORT(void,png_write_rows
) PNGARG((png_structp png_ptr
,
1785 png_bytepp row
, png_uint_32 num_rows
));
1787 /* Write the image data */
1788 extern PNG_EXPORT(void,png_write_image
) PNGARG((png_structp png_ptr
,
1791 /* Write the end of the PNG file. */
1792 extern PNG_EXPORT(void,png_write_end
) PNGARG((png_structp png_ptr
,
1793 png_infop info_ptr
));
1795 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1796 /* Read the end of the PNG file. */
1797 extern PNG_EXPORT(void,png_read_end
) PNGARG((png_structp png_ptr
,
1798 png_infop info_ptr
));
1801 /* Free any memory associated with the png_info_struct */
1802 extern PNG_EXPORT(void,png_destroy_info_struct
) PNGARG((png_structp png_ptr
,
1803 png_infopp info_ptr_ptr
));
1805 /* Free any memory associated with the png_struct and the png_info_structs */
1806 extern PNG_EXPORT(void,png_destroy_read_struct
) PNGARG((png_structpp
1807 png_ptr_ptr
, png_infopp info_ptr_ptr
, png_infopp end_info_ptr_ptr
));
1809 /* Free any memory associated with the png_struct and the png_info_structs */
1810 extern PNG_EXPORT(void,png_destroy_write_struct
)
1811 PNGARG((png_structpp png_ptr_ptr
, png_infopp info_ptr_ptr
));
1813 /* Set the libpng method of handling chunk CRC errors */
1814 extern PNG_EXPORT(void,png_set_crc_action
) PNGARG((png_structp png_ptr
,
1815 int crit_action
, int ancil_action
));
1817 /* Values for png_set_crc_action() to say how to handle CRC errors in
1818 * ancillary and critical chunks, and whether to use the data contained
1819 * therein. Note that it is impossible to "discard" data in a critical
1820 * chunk. For versions prior to 0.90, the action was always error/quit,
1821 * whereas in version 0.90 and later, the action for CRC errors in ancillary
1822 * chunks is warn/discard. These values should NOT be changed.
1824 * value action:critical action:ancillary
1826 #define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */
1827 #define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */
1828 #define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */
1829 #define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */
1830 #define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */
1831 #define PNG_CRC_NO_CHANGE 5 /* use current value use current value */
1833 /* These functions give the user control over the scan-line filtering in
1834 * libpng and the compression methods used by zlib. These functions are
1835 * mainly useful for testing, as the defaults should work with most users.
1836 * Those users who are tight on memory or want faster performance at the
1837 * expense of compression can modify them. See the compression library
1838 * header file (zlib.h) for an explination of the compression functions.
1841 /* Set the filtering method(s) used by libpng. Currently, the only valid
1842 * value for "method" is 0.
1844 extern PNG_EXPORT(void,png_set_filter
) PNGARG((png_structp png_ptr
, int method
,
1847 /* Flags for png_set_filter() to say which filters to use. The flags
1848 * are chosen so that they don't conflict with real filter types
1849 * below, in case they are supplied instead of the #defined constants.
1850 * These values should NOT be changed.
1852 #define PNG_NO_FILTERS 0x00
1853 #define PNG_FILTER_NONE 0x08
1854 #define PNG_FILTER_SUB 0x10
1855 #define PNG_FILTER_UP 0x20
1856 #define PNG_FILTER_AVG 0x40
1857 #define PNG_FILTER_PAETH 0x80
1858 #define PNG_ALL_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP | \
1859 PNG_FILTER_AVG | PNG_FILTER_PAETH)
1861 /* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
1862 * These defines should NOT be changed.
1864 #define PNG_FILTER_VALUE_NONE 0
1865 #define PNG_FILTER_VALUE_SUB 1
1866 #define PNG_FILTER_VALUE_UP 2
1867 #define PNG_FILTER_VALUE_AVG 3
1868 #define PNG_FILTER_VALUE_PAETH 4
1869 #define PNG_FILTER_VALUE_LAST 5
1871 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* EXPERIMENTAL */
1872 /* The "heuristic_method" is given by one of the PNG_FILTER_HEURISTIC_
1873 * defines, either the default (minimum-sum-of-absolute-differences), or
1874 * the experimental method (weighted-minimum-sum-of-absolute-differences).
1876 * Weights are factors >= 1.0, indicating how important it is to keep the
1877 * filter type consistent between rows. Larger numbers mean the current
1878 * filter is that many times as likely to be the same as the "num_weights"
1879 * previous filters. This is cumulative for each previous row with a weight.
1880 * There needs to be "num_weights" values in "filter_weights", or it can be
1881 * NULL if the weights aren't being specified. Weights have no influence on
1882 * the selection of the first row filter. Well chosen weights can (in theory)
1883 * improve the compression for a given image.
1885 * Costs are factors >= 1.0 indicating the relative decoding costs of a
1886 * filter type. Higher costs indicate more decoding expense, and are
1887 * therefore less likely to be selected over a filter with lower computational
1888 * costs. There needs to be a value in "filter_costs" for each valid filter
1889 * type (given by PNG_FILTER_VALUE_LAST), or it can be NULL if you aren't
1890 * setting the costs. Costs try to improve the speed of decompression without
1891 * unduly increasing the compressed image size.
1893 * A negative weight or cost indicates the default value is to be used, and
1894 * values in the range [0.0, 1.0) indicate the value is to remain unchanged.
1895 * The default values for both weights and costs are currently 1.0, but may
1896 * change if good general weighting/cost heuristics can be found. If both
1897 * the weights and costs are set to 1.0, this degenerates the WEIGHTED method
1898 * to the UNWEIGHTED method, but with added encoding time/computation.
1900 #ifdef PNG_FLOATING_POINT_SUPPORTED
1901 extern PNG_EXPORT(void,png_set_filter_heuristics
) PNGARG((png_structp png_ptr
,
1902 int heuristic_method
, int num_weights
, png_doublep filter_weights
,
1903 png_doublep filter_costs
));
1905 #endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
1907 /* Heuristic used for row filter selection. These defines should NOT be
1910 #define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */
1911 #define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */
1912 #define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */
1913 #define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */
1915 /* Set the library compression level. Currently, valid values range from
1916 * 0 - 9, corresponding directly to the zlib compression levels 0 - 9
1917 * (0 - no compression, 9 - "maximal" compression). Note that tests have
1918 * shown that zlib compression levels 3-6 usually perform as well as level 9
1919 * for PNG images, and do considerably fewer caclulations. In the future,
1920 * these values may not correspond directly to the zlib compression levels.
1922 extern PNG_EXPORT(void,png_set_compression_level
) PNGARG((png_structp png_ptr
,
1925 extern PNG_EXPORT(void,png_set_compression_mem_level
)
1926 PNGARG((png_structp png_ptr
, int mem_level
));
1928 extern PNG_EXPORT(void,png_set_compression_strategy
)
1929 PNGARG((png_structp png_ptr
, int strategy
));
1931 extern PNG_EXPORT(void,png_set_compression_window_bits
)
1932 PNGARG((png_structp png_ptr
, int window_bits
));
1934 extern PNG_EXPORT(void,png_set_compression_method
) PNGARG((png_structp png_ptr
,
1937 /* These next functions are called for input/output, memory, and error
1938 * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c,
1939 * and call standard C I/O routines such as fread(), fwrite(), and
1940 * fprintf(). These functions can be made to use other I/O routines
1941 * at run time for those applications that need to handle I/O in a
1942 * different manner by calling png_set_???_fn(). See libpng.txt for
1946 #ifdef PNG_STDIO_SUPPORTED
1947 /* Initialize the input/output for the PNG file to the default functions. */
1948 extern PNG_EXPORT(void,png_init_io
) PNGARG((png_structp png_ptr
,
1952 /* Replace the (error and abort), and warning functions with user
1953 * supplied functions. If no messages are to be printed you must still
1954 * write and use replacement functions. The replacement error_fn should
1955 * still do a longjmp to the last setjmp location if you are using this
1956 * method of error handling. If error_fn or warning_fn is NULL, the
1957 * default function will be used.
1960 extern PNG_EXPORT(void,png_set_error_fn
) PNGARG((png_structp png_ptr
,
1961 png_voidp error_ptr
, png_error_ptr error_fn
, png_error_ptr warning_fn
));
1963 /* Return the user pointer associated with the error functions */
1964 extern PNG_EXPORT(png_voidp
,png_get_error_ptr
) PNGARG((png_structp png_ptr
));
1966 /* Replace the default data output functions with a user supplied one(s).
1967 * If buffered output is not used, then output_flush_fn can be set to NULL.
1968 * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time
1969 * output_flush_fn will be ignored (and thus can be NULL).
1970 * It is probably a mistake to use NULL for output_flush_fn if
1971 * write_data_fn is not also NULL unless you have built libpng with
1972 * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's
1973 * default flush function, which uses the standard *FILE structure, will
1976 extern PNG_EXPORT(void,png_set_write_fn
) PNGARG((png_structp png_ptr
,
1977 png_voidp io_ptr
, png_rw_ptr write_data_fn
, png_flush_ptr output_flush_fn
));
1979 /* Replace the default data input function with a user supplied one. */
1980 extern PNG_EXPORT(void,png_set_read_fn
) PNGARG((png_structp png_ptr
,
1981 png_voidp io_ptr
, png_rw_ptr read_data_fn
));
1983 /* Return the user pointer associated with the I/O functions */
1984 extern PNG_EXPORT(png_voidp
,png_get_io_ptr
) PNGARG((png_structp png_ptr
));
1986 extern PNG_EXPORT(void,png_set_read_status_fn
) PNGARG((png_structp png_ptr
,
1987 png_read_status_ptr read_row_fn
));
1989 extern PNG_EXPORT(void,png_set_write_status_fn
) PNGARG((png_structp png_ptr
,
1990 png_write_status_ptr write_row_fn
));
1992 #ifdef PNG_USER_MEM_SUPPORTED
1993 /* Replace the default memory allocation functions with user supplied one(s). */
1994 extern PNG_EXPORT(void,png_set_mem_fn
) PNGARG((png_structp png_ptr
,
1995 png_voidp mem_ptr
, png_malloc_ptr malloc_fn
, png_free_ptr free_fn
));
1996 /* Return the user pointer associated with the memory functions */
1997 extern PNG_EXPORT(png_voidp
,png_get_mem_ptr
) PNGARG((png_structp png_ptr
));
2000 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
2001 extern PNG_EXPORT(void,png_set_read_user_transform_fn
) PNGARG((png_structp
2002 png_ptr
, png_user_transform_ptr read_user_transform_fn
));
2005 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
2006 extern PNG_EXPORT(void,png_set_write_user_transform_fn
) PNGARG((png_structp
2007 png_ptr
, png_user_transform_ptr write_user_transform_fn
));
2010 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
2011 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
2012 extern PNG_EXPORT(void,png_set_user_transform_info
) PNGARG((png_structp
2013 png_ptr
, png_voidp user_transform_ptr
, int user_transform_depth
,
2014 int user_transform_channels
));
2015 /* Return the user pointer associated with the user transform functions */
2016 extern PNG_EXPORT(png_voidp
,png_get_user_transform_ptr
)
2017 PNGARG((png_structp png_ptr
));
2020 #ifdef PNG_USER_CHUNKS_SUPPORTED
2021 extern PNG_EXPORT(void,png_set_read_user_chunk_fn
) PNGARG((png_structp png_ptr
,
2022 png_voidp user_chunk_ptr
, png_user_chunk_ptr read_user_chunk_fn
));
2023 extern PNG_EXPORT(png_voidp
,png_get_user_chunk_ptr
) PNGARG((png_structp
2027 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
2028 /* Sets the function callbacks for the push reader, and a pointer to a
2029 * user-defined structure available to the callback functions.
2031 extern PNG_EXPORT(void,png_set_progressive_read_fn
) PNGARG((png_structp png_ptr
,
2032 png_voidp progressive_ptr
,
2033 png_progressive_info_ptr info_fn
, png_progressive_row_ptr row_fn
,
2034 png_progressive_end_ptr end_fn
));
2036 /* Returns the user pointer associated with the push read functions */
2037 extern PNG_EXPORT(png_voidp
,png_get_progressive_ptr
)
2038 PNGARG((png_structp png_ptr
));
2040 /* Function to be called when data becomes available */
2041 extern PNG_EXPORT(void,png_process_data
) PNGARG((png_structp png_ptr
,
2042 png_infop info_ptr
, png_bytep buffer
, png_size_t buffer_size
));
2044 /* Function that combines rows. Not very much different than the
2045 * png_combine_row() call. Is this even used?????
2047 extern PNG_EXPORT(void,png_progressive_combine_row
) PNGARG((png_structp png_ptr
,
2048 png_bytep old_row
, png_bytep new_row
));
2049 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
2051 extern PNG_EXPORT(png_voidp
,png_malloc
) PNGARG((png_structp png_ptr
,
2052 png_alloc_size_t size
)) PNG_ALLOCATED
;
2053 /* Added at libpng version 1.4.0 */
2054 extern PNG_EXPORT(png_voidp
,png_calloc
) PNGARG((png_structp png_ptr
,
2055 png_alloc_size_t size
)) PNG_ALLOCATED
;
2057 /* Added at libpng version 1.2.4 */
2058 extern PNG_EXPORT(png_voidp
,png_malloc_warn
) PNGARG((png_structp png_ptr
,
2059 png_alloc_size_t size
)) PNG_ALLOCATED
;
2061 /* Frees a pointer allocated by png_malloc() */
2062 extern PNG_EXPORT(void,png_free
) PNGARG((png_structp png_ptr
, png_voidp ptr
));
2064 /* Free data that was allocated internally */
2065 extern PNG_EXPORT(void,png_free_data
) PNGARG((png_structp png_ptr
,
2066 png_infop info_ptr
, png_uint_32 free_me
, int num
));
2067 /* Reassign responsibility for freeing existing data, whether allocated
2068 * by libpng or by the application */
2069 extern PNG_EXPORT(void,png_data_freer
) PNGARG((png_structp png_ptr
,
2070 png_infop info_ptr
, int freer
, png_uint_32 mask
));
2071 /* Assignments for png_data_freer */
2072 #define PNG_DESTROY_WILL_FREE_DATA 1
2073 #define PNG_SET_WILL_FREE_DATA 1
2074 #define PNG_USER_WILL_FREE_DATA 2
2075 /* Flags for png_ptr->free_me and info_ptr->free_me */
2076 #define PNG_FREE_HIST 0x0008
2077 #define PNG_FREE_ICCP 0x0010
2078 #define PNG_FREE_SPLT 0x0020
2079 #define PNG_FREE_ROWS 0x0040
2080 #define PNG_FREE_PCAL 0x0080
2081 #define PNG_FREE_SCAL 0x0100
2082 #define PNG_FREE_UNKN 0x0200
2083 #define PNG_FREE_LIST 0x0400
2084 #define PNG_FREE_PLTE 0x1000
2085 #define PNG_FREE_TRNS 0x2000
2086 #define PNG_FREE_TEXT 0x4000
2087 #define PNG_FREE_ALL 0x7fff
2088 #define PNG_FREE_MUL 0x4220 /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */
2090 #ifdef PNG_USER_MEM_SUPPORTED
2091 extern PNG_EXPORT(png_voidp
,png_malloc_default
) PNGARG((png_structp png_ptr
,
2092 png_alloc_size_t size
)) PNG_ALLOCATED
;
2093 extern PNG_EXPORT(void,png_free_default
) PNGARG((png_structp png_ptr
,
2097 #ifndef PNG_NO_ERROR_TEXT
2098 /* Fatal error in PNG image of libpng - can't continue */
2099 extern PNG_EXPORT(void,png_error
) PNGARG((png_structp png_ptr
,
2100 png_const_charp error_message
)) PNG_NORETURN
;
2102 /* The same, but the chunk name is prepended to the error string. */
2103 extern PNG_EXPORT(void,png_chunk_error
) PNGARG((png_structp png_ptr
,
2104 png_const_charp error_message
)) PNG_NORETURN
;
2107 /* Fatal error in PNG image of libpng - can't continue */
2108 extern PNG_EXPORT(void,png_err
) PNGARG((png_structp png_ptr
)) PNG_NORETURN
;
2111 /* Non-fatal error in libpng. Can continue, but may have a problem. */
2112 extern PNG_EXPORT(void,png_warning
) PNGARG((png_structp png_ptr
,
2113 png_const_charp warning_message
));
2115 /* Non-fatal error in libpng, chunk name is prepended to message. */
2116 extern PNG_EXPORT(void,png_chunk_warning
) PNGARG((png_structp png_ptr
,
2117 png_const_charp warning_message
));
2119 #ifdef PNG_BENIGN_ERRORS_SUPPORTED
2120 /* Benign error in libpng. Can continue, but may have a problem.
2121 * User can choose whether to handle as a fatal error or as a warning. */
2122 extern PNG_EXPORT(void,png_benign_error
) PNGARG((png_structp png_ptr
,
2123 png_const_charp warning_message
));
2125 /* Same, chunk name is prepended to message. */
2126 extern PNG_EXPORT(void,png_chunk_benign_error
) PNGARG((png_structp png_ptr
,
2127 png_const_charp warning_message
));
2129 extern PNG_EXPORT(void,png_set_benign_errors
) PNGARG((png_structp
2130 png_ptr
, int allowed
));
2133 /* The png_set_<chunk> functions are for storing values in the png_info_struct.
2134 * Similarly, the png_get_<chunk> calls are used to read values from the
2135 * png_info_struct, either storing the parameters in the passed variables, or
2136 * setting pointers into the png_info_struct where the data is stored. The
2137 * png_get_<chunk> functions return a non-zero value if the data was available
2138 * in info_ptr, or return zero and do not change any of the parameters if the
2139 * data was not available.
2141 * These functions should be used instead of directly accessing png_info
2142 * to avoid problems with future changes in the size and internal layout of
2145 /* Returns "flag" if chunk data is valid in info_ptr. */
2146 extern PNG_EXPORT(png_uint_32
,png_get_valid
) PNGARG((png_structp png_ptr
,
2147 png_infop info_ptr
, png_uint_32 flag
));
2149 /* Returns number of bytes needed to hold a transformed row. */
2150 extern PNG_EXPORT(png_size_t
,png_get_rowbytes
) PNGARG((png_structp png_ptr
,
2151 png_infop info_ptr
));
2153 #ifdef PNG_INFO_IMAGE_SUPPORTED
2154 /* Returns row_pointers, which is an array of pointers to scanlines that was
2155 * returned from png_read_png().
2157 extern PNG_EXPORT(png_bytepp
,png_get_rows
) PNGARG((png_structp png_ptr
,
2158 png_infop info_ptr
));
2159 /* Set row_pointers, which is an array of pointers to scanlines for use
2160 * by png_write_png().
2162 extern PNG_EXPORT(void,png_set_rows
) PNGARG((png_structp png_ptr
,
2163 png_infop info_ptr
, png_bytepp row_pointers
));
2166 /* Returns number of color channels in image. */
2167 extern PNG_EXPORT(png_byte
,png_get_channels
) PNGARG((png_structp png_ptr
,
2168 png_infop info_ptr
));
2170 #ifdef PNG_EASY_ACCESS_SUPPORTED
2171 /* Returns image width in pixels. */
2172 extern PNG_EXPORT(png_uint_32
, png_get_image_width
) PNGARG((png_structp
2173 png_ptr
, png_infop info_ptr
));
2175 /* Returns image height in pixels. */
2176 extern PNG_EXPORT(png_uint_32
, png_get_image_height
) PNGARG((png_structp
2177 png_ptr
, png_infop info_ptr
));
2179 /* Returns image bit_depth. */
2180 extern PNG_EXPORT(png_byte
, png_get_bit_depth
) PNGARG((png_structp
2181 png_ptr
, png_infop info_ptr
));
2183 /* Returns image color_type. */
2184 extern PNG_EXPORT(png_byte
, png_get_color_type
) PNGARG((png_structp
2185 png_ptr
, png_infop info_ptr
));
2187 /* Returns image filter_type. */
2188 extern PNG_EXPORT(png_byte
, png_get_filter_type
) PNGARG((png_structp
2189 png_ptr
, png_infop info_ptr
));
2191 /* Returns image interlace_type. */
2192 extern PNG_EXPORT(png_byte
, png_get_interlace_type
) PNGARG((png_structp
2193 png_ptr
, png_infop info_ptr
));
2195 /* Returns image compression_type. */
2196 extern PNG_EXPORT(png_byte
, png_get_compression_type
) PNGARG((png_structp
2197 png_ptr
, png_infop info_ptr
));
2199 /* Returns image resolution in pixels per meter, from pHYs chunk data. */
2200 extern PNG_EXPORT(png_uint_32
, png_get_pixels_per_meter
) PNGARG((png_structp
2201 png_ptr
, png_infop info_ptr
));
2202 extern PNG_EXPORT(png_uint_32
, png_get_x_pixels_per_meter
) PNGARG((png_structp
2203 png_ptr
, png_infop info_ptr
));
2204 extern PNG_EXPORT(png_uint_32
, png_get_y_pixels_per_meter
) PNGARG((png_structp
2205 png_ptr
, png_infop info_ptr
));
2207 /* Returns pixel aspect ratio, computed from pHYs chunk data. */
2208 #ifdef PNG_FLOATING_POINT_SUPPORTED
2209 extern PNG_EXPORT(float, png_get_pixel_aspect_ratio
) PNGARG((png_structp
2210 png_ptr
, png_infop info_ptr
));
2213 /* Returns image x, y offset in pixels or microns, from oFFs chunk data. */
2214 extern PNG_EXPORT(png_int_32
, png_get_x_offset_pixels
) PNGARG((png_structp
2215 png_ptr
, png_infop info_ptr
));
2216 extern PNG_EXPORT(png_int_32
, png_get_y_offset_pixels
) PNGARG((png_structp
2217 png_ptr
, png_infop info_ptr
));
2218 extern PNG_EXPORT(png_int_32
, png_get_x_offset_microns
) PNGARG((png_structp
2219 png_ptr
, png_infop info_ptr
));
2220 extern PNG_EXPORT(png_int_32
, png_get_y_offset_microns
) PNGARG((png_structp
2221 png_ptr
, png_infop info_ptr
));
2223 #endif /* PNG_EASY_ACCESS_SUPPORTED */
2225 /* Returns pointer to signature string read from PNG header */
2226 extern PNG_EXPORT(png_bytep
,png_get_signature
) PNGARG((png_structp png_ptr
,
2227 png_infop info_ptr
));
2229 #ifdef PNG_bKGD_SUPPORTED
2230 extern PNG_EXPORT(png_uint_32
,png_get_bKGD
) PNGARG((png_structp png_ptr
,
2231 png_infop info_ptr
, png_color_16p
*background
));
2234 #ifdef PNG_bKGD_SUPPORTED
2235 extern PNG_EXPORT(void,png_set_bKGD
) PNGARG((png_structp png_ptr
,
2236 png_infop info_ptr
, png_color_16p background
));
2239 #ifdef PNG_cHRM_SUPPORTED
2240 #ifdef PNG_FLOATING_POINT_SUPPORTED
2241 extern PNG_EXPORT(png_uint_32
,png_get_cHRM
) PNGARG((png_structp png_ptr
,
2242 png_infop info_ptr
, double *white_x
, double *white_y
, double *red_x
,
2243 double *red_y
, double *green_x
, double *green_y
, double *blue_x
,
2246 #ifdef PNG_FIXED_POINT_SUPPORTED
2247 extern PNG_EXPORT(png_uint_32
,png_get_cHRM_fixed
) PNGARG((png_structp png_ptr
,
2248 png_infop info_ptr
, png_fixed_point
*int_white_x
, png_fixed_point
2249 *int_white_y
, png_fixed_point
*int_red_x
, png_fixed_point
*int_red_y
,
2250 png_fixed_point
*int_green_x
, png_fixed_point
*int_green_y
, png_fixed_point
2251 *int_blue_x
, png_fixed_point
*int_blue_y
));
2255 #ifdef PNG_cHRM_SUPPORTED
2256 #ifdef PNG_FLOATING_POINT_SUPPORTED
2257 extern PNG_EXPORT(void,png_set_cHRM
) PNGARG((png_structp png_ptr
,
2258 png_infop info_ptr
, double white_x
, double white_y
, double red_x
,
2259 double red_y
, double green_x
, double green_y
, double blue_x
, double blue_y
));
2261 #ifdef PNG_FIXED_POINT_SUPPORTED
2262 extern PNG_EXPORT(void,png_set_cHRM_fixed
) PNGARG((png_structp png_ptr
,
2263 png_infop info_ptr
, png_fixed_point int_white_x
, png_fixed_point int_white_y
,
2264 png_fixed_point int_red_x
, png_fixed_point int_red_y
, png_fixed_point
2265 int_green_x
, png_fixed_point int_green_y
, png_fixed_point int_blue_x
,
2266 png_fixed_point int_blue_y
));
2270 #ifdef PNG_gAMA_SUPPORTED
2271 #ifdef PNG_FLOATING_POINT_SUPPORTED
2272 extern PNG_EXPORT(png_uint_32
,png_get_gAMA
) PNGARG((png_structp png_ptr
,
2273 png_infop info_ptr
, double *file_gamma
));
2275 extern PNG_EXPORT(png_uint_32
,png_get_gAMA_fixed
) PNGARG((png_structp png_ptr
,
2276 png_infop info_ptr
, png_fixed_point
*int_file_gamma
));
2279 #ifdef PNG_gAMA_SUPPORTED
2280 #ifdef PNG_FLOATING_POINT_SUPPORTED
2281 extern PNG_EXPORT(void,png_set_gAMA
) PNGARG((png_structp png_ptr
,
2282 png_infop info_ptr
, double file_gamma
));
2284 extern PNG_EXPORT(void,png_set_gAMA_fixed
) PNGARG((png_structp png_ptr
,
2285 png_infop info_ptr
, png_fixed_point int_file_gamma
));
2288 #ifdef PNG_hIST_SUPPORTED
2289 extern PNG_EXPORT(png_uint_32
,png_get_hIST
) PNGARG((png_structp png_ptr
,
2290 png_infop info_ptr
, png_uint_16p
*hist
));
2293 #ifdef PNG_hIST_SUPPORTED
2294 extern PNG_EXPORT(void,png_set_hIST
) PNGARG((png_structp png_ptr
,
2295 png_infop info_ptr
, png_uint_16p hist
));
2298 extern PNG_EXPORT(png_uint_32
,png_get_IHDR
) PNGARG((png_structp png_ptr
,
2299 png_infop info_ptr
, png_uint_32
*width
, png_uint_32
*height
,
2300 int *bit_depth
, int *color_type
, int *interlace_method
,
2301 int *compression_method
, int *filter_method
));
2303 extern PNG_EXPORT(void,png_set_IHDR
) PNGARG((png_structp png_ptr
,
2304 png_infop info_ptr
, png_uint_32 width
, png_uint_32 height
, int bit_depth
,
2305 int color_type
, int interlace_method
, int compression_method
,
2306 int filter_method
));
2308 #ifdef PNG_oFFs_SUPPORTED
2309 extern PNG_EXPORT(png_uint_32
,png_get_oFFs
) PNGARG((png_structp png_ptr
,
2310 png_infop info_ptr
, png_int_32
*offset_x
, png_int_32
*offset_y
,
2314 #ifdef PNG_oFFs_SUPPORTED
2315 extern PNG_EXPORT(void,png_set_oFFs
) PNGARG((png_structp png_ptr
,
2316 png_infop info_ptr
, png_int_32 offset_x
, png_int_32 offset_y
,
2320 #ifdef PNG_pCAL_SUPPORTED
2321 extern PNG_EXPORT(png_uint_32
,png_get_pCAL
) PNGARG((png_structp png_ptr
,
2322 png_infop info_ptr
, png_charp
*purpose
, png_int_32
*X0
, png_int_32
*X1
,
2323 int *type
, int *nparams
, png_charp
*units
, png_charpp
*params
));
2326 #ifdef PNG_pCAL_SUPPORTED
2327 extern PNG_EXPORT(void,png_set_pCAL
) PNGARG((png_structp png_ptr
,
2328 png_infop info_ptr
, png_charp purpose
, png_int_32 X0
, png_int_32 X1
,
2329 int type
, int nparams
, png_charp units
, png_charpp params
));
2332 #ifdef PNG_pHYs_SUPPORTED
2333 extern PNG_EXPORT(png_uint_32
,png_get_pHYs
) PNGARG((png_structp png_ptr
,
2334 png_infop info_ptr
, png_uint_32
*res_x
, png_uint_32
*res_y
, int *unit_type
));
2337 #ifdef PNG_pHYs_SUPPORTED
2338 extern PNG_EXPORT(void,png_set_pHYs
) PNGARG((png_structp png_ptr
,
2339 png_infop info_ptr
, png_uint_32 res_x
, png_uint_32 res_y
, int unit_type
));
2342 extern PNG_EXPORT(png_uint_32
,png_get_PLTE
) PNGARG((png_structp png_ptr
,
2343 png_infop info_ptr
, png_colorp
*palette
, int *num_palette
));
2345 extern PNG_EXPORT(void,png_set_PLTE
) PNGARG((png_structp png_ptr
,
2346 png_infop info_ptr
, png_colorp palette
, int num_palette
));
2348 #ifdef PNG_sBIT_SUPPORTED
2349 extern PNG_EXPORT(png_uint_32
,png_get_sBIT
) PNGARG((png_structp png_ptr
,
2350 png_infop info_ptr
, png_color_8p
*sig_bit
));
2353 #ifdef PNG_sBIT_SUPPORTED
2354 extern PNG_EXPORT(void,png_set_sBIT
) PNGARG((png_structp png_ptr
,
2355 png_infop info_ptr
, png_color_8p sig_bit
));
2358 #ifdef PNG_sRGB_SUPPORTED
2359 extern PNG_EXPORT(png_uint_32
,png_get_sRGB
) PNGARG((png_structp png_ptr
,
2360 png_infop info_ptr
, int *intent
));
2363 #ifdef PNG_sRGB_SUPPORTED
2364 extern PNG_EXPORT(void,png_set_sRGB
) PNGARG((png_structp png_ptr
,
2365 png_infop info_ptr
, int intent
));
2366 extern PNG_EXPORT(void,png_set_sRGB_gAMA_and_cHRM
) PNGARG((png_structp png_ptr
,
2367 png_infop info_ptr
, int intent
));
2370 #ifdef PNG_iCCP_SUPPORTED
2371 extern PNG_EXPORT(png_uint_32
,png_get_iCCP
) PNGARG((png_structp png_ptr
,
2372 png_infop info_ptr
, png_charpp name
, int *compression_type
,
2373 png_charpp profile
, png_uint_32
*proflen
));
2374 /* Note to maintainer: profile should be png_bytepp */
2377 #ifdef PNG_iCCP_SUPPORTED
2378 extern PNG_EXPORT(void,png_set_iCCP
) PNGARG((png_structp png_ptr
,
2379 png_infop info_ptr
, png_charp name
, int compression_type
,
2380 png_charp profile
, png_uint_32 proflen
));
2381 /* Note to maintainer: profile should be png_bytep */
2384 #ifdef PNG_sPLT_SUPPORTED
2385 extern PNG_EXPORT(png_uint_32
,png_get_sPLT
) PNGARG((png_structp png_ptr
,
2386 png_infop info_ptr
, png_sPLT_tpp entries
));
2389 #ifdef PNG_sPLT_SUPPORTED
2390 extern PNG_EXPORT(void,png_set_sPLT
) PNGARG((png_structp png_ptr
,
2391 png_infop info_ptr
, png_sPLT_tp entries
, int nentries
));
2394 #ifdef PNG_TEXT_SUPPORTED
2395 /* png_get_text also returns the number of text chunks in *num_text */
2396 extern PNG_EXPORT(png_uint_32
,png_get_text
) PNGARG((png_structp png_ptr
,
2397 png_infop info_ptr
, png_textp
*text_ptr
, int *num_text
));
2400 /* Note while png_set_text() will accept a structure whose text,
2401 * language, and translated keywords are NULL pointers, the structure
2402 * returned by png_get_text will always contain regular
2403 * zero-terminated C strings. They might be empty strings but
2404 * they will never be NULL pointers.
2407 #ifdef PNG_TEXT_SUPPORTED
2408 extern PNG_EXPORT(void,png_set_text
) PNGARG((png_structp png_ptr
,
2409 png_infop info_ptr
, png_textp text_ptr
, int num_text
));
2412 #ifdef PNG_tIME_SUPPORTED
2413 extern PNG_EXPORT(png_uint_32
,png_get_tIME
) PNGARG((png_structp png_ptr
,
2414 png_infop info_ptr
, png_timep
*mod_time
));
2417 #ifdef PNG_tIME_SUPPORTED
2418 extern PNG_EXPORT(void,png_set_tIME
) PNGARG((png_structp png_ptr
,
2419 png_infop info_ptr
, png_timep mod_time
));
2422 #ifdef PNG_tRNS_SUPPORTED
2423 extern PNG_EXPORT(png_uint_32
,png_get_tRNS
) PNGARG((png_structp png_ptr
,
2424 png_infop info_ptr
, png_bytep
*trans_alpha
, int *num_trans
,
2425 png_color_16p
*trans_color
));
2428 #ifdef PNG_tRNS_SUPPORTED
2429 extern PNG_EXPORT(void,png_set_tRNS
) PNGARG((png_structp png_ptr
,
2430 png_infop info_ptr
, png_bytep trans_alpha
, int num_trans
,
2431 png_color_16p trans_color
));
2434 #ifdef PNG_tRNS_SUPPORTED
2437 #ifdef PNG_sCAL_SUPPORTED
2438 #ifdef PNG_FLOATING_POINT_SUPPORTED
2439 extern PNG_EXPORT(png_uint_32
,png_get_sCAL
) PNGARG((png_structp png_ptr
,
2440 png_infop info_ptr
, int *unit
, double *width
, double *height
));
2442 #ifdef PNG_FIXED_POINT_SUPPORTED
2443 extern PNG_EXPORT(png_uint_32
,png_get_sCAL_s
) PNGARG((png_structp png_ptr
,
2444 png_infop info_ptr
, int *unit
, png_charpp swidth
, png_charpp sheight
));
2447 #endif /* PNG_sCAL_SUPPORTED */
2449 #ifdef PNG_sCAL_SUPPORTED
2450 #ifdef PNG_FLOATING_POINT_SUPPORTED
2451 extern PNG_EXPORT(void,png_set_sCAL
) PNGARG((png_structp png_ptr
,
2452 png_infop info_ptr
, int unit
, double width
, double height
));
2454 #ifdef PNG_FIXED_POINT_SUPPORTED
2455 extern PNG_EXPORT(void,png_set_sCAL_s
) PNGARG((png_structp png_ptr
,
2456 png_infop info_ptr
, int unit
, png_charp swidth
, png_charp sheight
));
2459 #endif /* PNG_sCAL_SUPPORTED || PNG_WRITE_sCAL_SUPPORTED */
2461 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
2462 /* Provide a list of chunks and how they are to be handled, if the built-in
2463 handling or default unknown chunk handling is not desired. Any chunks not
2464 listed will be handled in the default manner. The IHDR and IEND chunks
2466 keep = 0: follow default behaviour
2468 = 2: keep only if safe-to-copy
2469 = 3: keep even if unsafe-to-copy
2471 extern PNG_EXPORT(void, png_set_keep_unknown_chunks
) PNGARG((png_structp
2472 png_ptr
, int keep
, png_bytep chunk_list
, int num_chunks
));
2473 PNG_EXPORT(int,png_handle_as_unknown
) PNGARG((png_structp png_ptr
, png_bytep
2476 #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
2477 extern PNG_EXPORT(void, png_set_unknown_chunks
) PNGARG((png_structp png_ptr
,
2478 png_infop info_ptr
, png_unknown_chunkp unknowns
, int num_unknowns
));
2479 extern PNG_EXPORT(void, png_set_unknown_chunk_location
)
2480 PNGARG((png_structp png_ptr
, png_infop info_ptr
, int chunk
, int location
));
2481 extern PNG_EXPORT(png_uint_32
,png_get_unknown_chunks
) PNGARG((png_structp
2482 png_ptr
, png_infop info_ptr
, png_unknown_chunkpp entries
));
2485 /* Png_free_data() will turn off the "valid" flag for anything it frees.
2486 * If you need to turn it off for a chunk that your application has freed,
2487 * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK);
2489 extern PNG_EXPORT(void, png_set_invalid
) PNGARG((png_structp png_ptr
,
2490 png_infop info_ptr
, int mask
));
2492 #ifdef PNG_INFO_IMAGE_SUPPORTED
2493 /* The "params" pointer is currently not used and is for future expansion. */
2494 extern PNG_EXPORT(void, png_read_png
) PNGARG((png_structp png_ptr
,
2498 extern PNG_EXPORT(void, png_write_png
) PNGARG((png_structp png_ptr
,
2504 extern PNG_EXPORT(png_charp
,png_get_copyright
) PNGARG((png_structp png_ptr
));
2505 extern PNG_EXPORT(png_charp
,png_get_header_ver
) PNGARG((png_structp png_ptr
));
2506 extern PNG_EXPORT(png_charp
,png_get_header_version
) PNGARG((png_structp
2508 extern PNG_EXPORT(png_charp
,png_get_libpng_ver
) PNGARG((png_structp png_ptr
));
2510 #ifdef PNG_MNG_FEATURES_SUPPORTED
2511 extern PNG_EXPORT(png_uint_32
,png_permit_mng_features
) PNGARG((png_structp
2512 png_ptr
, png_uint_32 mng_features_permitted
));
2515 /* For use in png_set_keep_unknown, added to version 1.2.6 */
2516 #define PNG_HANDLE_CHUNK_AS_DEFAULT 0
2517 #define PNG_HANDLE_CHUNK_NEVER 1
2518 #define PNG_HANDLE_CHUNK_IF_SAFE 2
2519 #define PNG_HANDLE_CHUNK_ALWAYS 3
2521 /* Strip the prepended error numbers ("#nnn ") from error and warning
2522 * messages before passing them to the error or warning handler.
2524 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
2525 extern PNG_EXPORT(void,png_set_strip_error_numbers
) PNGARG((png_structp
2526 png_ptr
, png_uint_32 strip_mode
));
2529 /* Added in libpng-1.2.6 */
2530 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
2531 extern PNG_EXPORT(void,png_set_user_limits
) PNGARG((png_structp
2532 png_ptr
, png_uint_32 user_width_max
, png_uint_32 user_height_max
));
2533 extern PNG_EXPORT(png_uint_32
,png_get_user_width_max
) PNGARG((png_structp
2535 extern PNG_EXPORT(png_uint_32
,png_get_user_height_max
) PNGARG((png_structp
2537 /* Added in libpng-1.4.0 */
2538 extern PNG_EXPORT(void,png_set_chunk_cache_max
) PNGARG((png_structp
2539 png_ptr
, png_uint_32 user_chunk_cache_max
));
2540 extern PNG_EXPORT(png_uint_32
,png_get_chunk_cache_max
)
2541 PNGARG((png_structp png_ptr
));
2542 /* Added in libpng-1.4.1 */
2543 extern PNG_EXPORT(void,png_set_chunk_malloc_max
) PNGARG((png_structp
2544 png_ptr
, png_alloc_size_t user_chunk_cache_max
));
2545 extern PNG_EXPORT(png_alloc_size_t
,png_get_chunk_malloc_max
)
2546 PNGARG((png_structp png_ptr
));
2549 #if defined(PNG_INCH_CONVERSIONS) && defined(PNG_FLOATING_POINT_SUPPORTED)
2550 PNG_EXPORT(png_uint_32
,png_get_pixels_per_inch
) PNGARG((png_structp png_ptr
,
2551 png_infop info_ptr
));
2553 PNG_EXPORT(png_uint_32
,png_get_x_pixels_per_inch
) PNGARG((png_structp png_ptr
,
2554 png_infop info_ptr
));
2556 PNG_EXPORT(png_uint_32
,png_get_y_pixels_per_inch
) PNGARG((png_structp png_ptr
,
2557 png_infop info_ptr
));
2559 PNG_EXPORT(float,png_get_x_offset_inches
) PNGARG((png_structp png_ptr
,
2560 png_infop info_ptr
));
2562 PNG_EXPORT(float,png_get_y_offset_inches
) PNGARG((png_structp png_ptr
,
2563 png_infop info_ptr
));
2565 #ifdef PNG_pHYs_SUPPORTED
2566 PNG_EXPORT(png_uint_32
,png_get_pHYs_dpi
) PNGARG((png_structp png_ptr
,
2567 png_infop info_ptr
, png_uint_32
*res_x
, png_uint_32
*res_y
, int *unit_type
));
2568 #endif /* PNG_pHYs_SUPPORTED */
2569 #endif /* PNG_INCH_CONVERSIONS && PNG_FLOATING_POINT_SUPPORTED */
2571 /* Added in libpng-1.4.0 */
2572 #ifdef PNG_IO_STATE_SUPPORTED
2573 extern PNG_EXPORT(png_uint_32
,png_get_io_state
) PNGARG((png_structp png_ptr
));
2575 extern PNG_EXPORT(png_bytep
,png_get_io_chunk_name
)
2576 PNGARG((png_structp png_ptr
));
2578 /* The flags returned by png_get_io_state() are the following: */
2579 #define PNG_IO_NONE 0x0000 /* no I/O at this moment */
2580 #define PNG_IO_READING 0x0001 /* currently reading */
2581 #define PNG_IO_WRITING 0x0002 /* currently writing */
2582 #define PNG_IO_SIGNATURE 0x0010 /* currently at the file signature */
2583 #define PNG_IO_CHUNK_HDR 0x0020 /* currently at the chunk header */
2584 #define PNG_IO_CHUNK_DATA 0x0040 /* currently at the chunk data */
2585 #define PNG_IO_CHUNK_CRC 0x0080 /* currently at the chunk crc */
2586 #define PNG_IO_MASK_OP 0x000f /* current operation: reading/writing */
2587 #define PNG_IO_MASK_LOC 0x00f0 /* current location: sig/hdr/data/crc */
2588 #endif /* ?PNG_IO_STATE_SUPPORTED */
2590 /* Maintainer: Put new public prototypes here ^, in libpng.3, and project
2594 #ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
2595 /* With these routines we avoid an integer divide, which will be slower on
2596 * most machines. However, it does take more operations than the corresponding
2597 * divide method, so it may be slower on a few RISC systems. There are two
2598 * shifts (by 8 or 16 bits) and an addition, versus a single integer divide.
2600 * Note that the rounding factors are NOT supposed to be the same! 128 and
2601 * 32768 are correct for the NODIV code; 127 and 32767 are correct for the
2604 * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
2607 /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */
2609 # define png_composite(composite, fg, alpha, bg) \
2610 { png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \
2611 * (png_uint_16)(alpha) \
2612 + (png_uint_16)(bg)*(png_uint_16)(255 \
2613 - (png_uint_16)(alpha)) + (png_uint_16)128); \
2614 (composite) = (png_byte)((temp + (temp >> 8)) >> 8); }
2616 # define png_composite_16(composite, fg, alpha, bg) \
2617 { png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) \
2618 * (png_uint_32)(alpha) \
2619 + (png_uint_32)(bg)*(png_uint_32)(65535L \
2620 - (png_uint_32)(alpha)) + (png_uint_32)32768L); \
2621 (composite) = (png_uint_16)((temp + (temp >> 16)) >> 16); }
2623 #else /* Standard method using integer division */
2625 # define png_composite(composite, fg, alpha, bg) \
2626 (composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) + \
2627 (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \
2628 (png_uint_16)127) / 255)
2630 # define png_composite_16(composite, fg, alpha, bg) \
2631 (composite) = (png_uint_16)(((png_uint_32)(fg) * (png_uint_32)(alpha) + \
2632 (png_uint_32)(bg)*(png_uint_32)(65535L - (png_uint_32)(alpha)) + \
2633 (png_uint_32)32767) / (png_uint_32)65535L)
2634 #endif /* PNG_READ_COMPOSITE_NODIV_SUPPORTED */
2636 #ifdef PNG_USE_READ_MACROS
2637 /* Inline macros to do direct reads of bytes from the input buffer.
2638 * The png_get_int_32() routine assumes we are using two's complement
2639 * format for negative values, which is almost certainly true.
2641 /* We could make special-case BIG_ENDIAN macros that do direct reads here */
2642 # define png_get_uint_32(buf) \
2643 (((png_uint_32)(*(buf)) << 24) + \
2644 ((png_uint_32)(*((buf) + 1)) << 16) + \
2645 ((png_uint_32)(*((buf) + 2)) << 8) + \
2646 ((png_uint_32)(*((buf) + 3))))
2647 # define png_get_uint_16(buf) \
2648 (((png_uint_32)(*(buf)) << 8) + \
2649 ((png_uint_32)(*((buf) + 1))))
2650 #ifdef PNG_GET_INT_32_SUPPORTED
2651 # define png_get_int_32(buf) \
2652 (((png_int_32)(*(buf)) << 24) + \
2653 ((png_int_32)(*((buf) + 1)) << 16) + \
2654 ((png_int_32)(*((buf) + 2)) << 8) + \
2655 ((png_int_32)(*((buf) + 3))))
2658 extern PNG_EXPORT(png_uint_32
,png_get_uint_32
) PNGARG((png_bytep buf
));
2659 extern PNG_EXPORT(png_uint_16
,png_get_uint_16
) PNGARG((png_bytep buf
));
2660 #ifdef PNG_GET_INT_32_SUPPORTED
2661 extern PNG_EXPORT(png_int_32
,png_get_int_32
) PNGARG((png_bytep buf
));
2664 extern PNG_EXPORT(png_uint_32
,png_get_uint_31
)
2665 PNGARG((png_structp png_ptr
, png_bytep buf
));
2666 /* No png_get_int_16 -- may be added if there's a real need for it. */
2668 /* Place a 32-bit number into a buffer in PNG byte order (big-endian). */
2669 extern PNG_EXPORT(void,png_save_uint_32
)
2670 PNGARG((png_bytep buf
, png_uint_32 i
));
2671 extern PNG_EXPORT(void,png_save_int_32
)
2672 PNGARG((png_bytep buf
, png_int_32 i
));
2674 /* Place a 16-bit number into a buffer in PNG byte order.
2675 * The parameter is declared unsigned int, not png_uint_16,
2676 * just to avoid potential problems on pre-ANSI C compilers.
2678 extern PNG_EXPORT(void,png_save_uint_16
)
2679 PNGARG((png_bytep buf
, unsigned int i
));
2680 /* No png_save_int_16 -- may be added if there's a real need for it. */
2682 /* ************************************************************************* */
2684 /* Various modes of operation. Note that after an init, mode is set to
2685 * zero automatically when the structure is created.
2687 #define PNG_HAVE_IHDR 0x01
2688 #define PNG_HAVE_PLTE 0x02
2689 #define PNG_HAVE_IDAT 0x04
2690 #define PNG_AFTER_IDAT 0x08 /* Have complete zlib datastream */
2691 #define PNG_HAVE_IEND 0x10
2692 #define PNG_HAVE_gAMA 0x20
2693 #define PNG_HAVE_cHRM 0x40
2699 #endif /* PNG_VERSION_INFO_ONLY */
2700 /* Do not put anything past this line */