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