1 /* png.h - header file for PNG reference library
3 * libpng version 1.2.5 - October 3, 2002
4 * Copyright (c) 1998-2002 Glenn Randers-Pehrson
5 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
6 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
8 * Authors and maintainers:
9 * libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
10 * libpng versions 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger
11 * libpng versions 0.97, January 1998, through 1.2.5 - October 3, 2002: Glenn
12 * See also "Contributing Authors", below.
14 * Note about libpng version numbers:
16 * Due to various miscommunications, unforeseen code incompatibilities
17 * and occasional factors outside the authors' control, version numbering
18 * on the library has not always been consistent and straightforward.
19 * The following table summarizes matters since version 0.89c, which was
20 * the first widely used release:
22 * source png.h png.h shared-lib
23 * version string int version
24 * ------- ------ ----- ----------
25 * 0.89c "1.0 beta 3" 0.89 89 1.0.89
26 * 0.90 "1.0 beta 4" 0.90 90 0.90 [should have been 2.0.90]
27 * 0.95 "1.0 beta 5" 0.95 95 0.95 [should have been 2.0.95]
28 * 0.96 "1.0 beta 6" 0.96 96 0.96 [should have been 2.0.96]
29 * 0.97b "1.00.97 beta 7" 1.00.97 97 1.0.1 [should have been 2.0.97]
30 * 0.97c 0.97 97 2.0.97
33 * 0.99a-m 0.99 99 2.0.99
34 * 1.00 1.00 100 2.1.0 [100 should be 10000]
35 * 1.0.0 (from here on, the 100 2.1.0 [100 should be 10000]
36 * 1.0.1 png.h string is 10001 2.1.0
37 * 1.0.1a-e identical to the 10002 from here on, the shared library
38 * 1.0.2 source version) 10002 is 2.V where V is the source code
39 * 1.0.2a-b 10003 version, except as noted.
44 * 1.0.5 (+ 2 patches) 10005
46 * 1.0.5e-r 10100 (not source compatible)
47 * 1.0.5s-v 10006 (not binary compatible)
48 * 1.0.6 (+ 3 patches) 10006 (still binary incompatible)
49 * 1.0.6d-f 10007 (still binary incompatible)
51 * 1.0.6h 10007 10.6h (testing xy.z so-numbering)
53 * 1.0.6j 10007 2.1.0.6j (incompatible with 1.0.0)
54 * 1.0.7beta11-14 DLLNUM 10007 2.1.0.7beta11-14 (binary compatible)
55 * 1.0.7beta15-18 1 10007 2.1.0.7beta15-18 (binary compatible)
56 * 1.0.7rc1-2 1 10007 2.1.0.7rc1-2 (binary compatible)
57 * 1.0.7 1 10007 (still compatible)
58 * 1.0.8beta1-4 1 10008 2.1.0.8beta1-4
59 * 1.0.8rc1 1 10008 2.1.0.8rc1
60 * 1.0.8 1 10008 2.1.0.8
61 * 1.0.9beta1-6 1 10009 2.1.0.9beta1-6
62 * 1.0.9rc1 1 10009 2.1.0.9rc1
63 * 1.0.9beta7-10 1 10009 2.1.0.9beta7-10
64 * 1.0.9rc2 1 10009 2.1.0.9rc2
65 * 1.0.9 1 10009 2.1.0.9
66 * 1.0.10beta1 1 10010 2.1.0.10beta1
67 * 1.0.10rc1 1 10010 2.1.0.10rc1
68 * 1.0.10 1 10010 2.1.0.10
69 * 1.0.11beta1-3 1 10011 2.1.0.11beta1-3
70 * 1.0.11rc1 1 10011 2.1.0.11rc1
71 * 1.0.11 1 10011 2.1.0.11
72 * 1.0.12beta1-2 2 10012 2.1.0.12beta1-2
73 * 1.0.12rc1 2 10012 2.1.0.12rc1
74 * 1.0.12 2 10012 2.1.0.12
75 * 1.1.0a-f - 10100 2.1.1.0a-f (branch abandoned)
76 * 1.2.0beta1-2 2 10200 2.1.2.0beta1-2
77 * 1.2.0beta3-5 3 10200 3.1.2.0beta3-5
78 * 1.2.0rc1 3 10200 3.1.2.0rc1
79 * 1.2.0 3 10200 3.1.2.0
80 * 1.2.1beta1-4 3 10201 3.1.2.1beta1-4
81 * 1.2.1rc1-2 3 10201 3.1.2.1rc1-2
82 * 1.2.1 3 10201 3.1.2.1
83 * 1.2.2beta1-6 12 10202 12.so.0.1.2.2beta1-6
84 * 1.0.13beta1 10 10013 10.so.0.1.0.13beta1
85 * 1.0.13rc1 10 10013 10.so.0.1.0.13rc1
86 * 1.2.2rc1 12 10202 12.so.0.1.2.2rc1
87 * 1.0.13 10 10013 10.so.0.1.0.13
88 * 1.2.2 12 10202 12.so.0.1.2.2
89 * 1.2.3rc1-6 12 10203 12.so.0.1.2.3rc1-6
90 * 1.2.3 12 10203 12.so.0.1.2.3
91 * 1.2.4beta1-3 13 10204 12.so.0.1.2.4beta1-3
92 * 1.0.14rc1 13 10014 10.so.0.1.0.14rc1
93 * 1.2.4rc1 13 10204 12.so.0.1.2.4rc1
94 * 1.0.14 10 10014 10.so.0.1.0.14
95 * 1.2.4 13 10204 12.so.0.1.2.4
96 * 1.2.5beta1-2 13 10205 12.so.0.1.2.5beta1-2
97 * 1.0.15rc1-3 10 10015 10.so.0.1.0.15rc1-3
98 * 1.2.5rc1-3 13 10205 12.so.0.1.2.5rc1-3
99 * 1.0.15 10 10015 10.so.0.1.0.15
100 * 1.2.5 13 10205 12.so.0.1.2.5
102 * Henceforth the source version will match the shared-library major
103 * and minor numbers; the shared-library major version number will be
104 * used for changes in backward compatibility, as it is intended. The
105 * PNG_LIBPNG_VER macro, which is not used within libpng but is available
106 * for applications, is an unsigned integer of the form xyyzz corresponding
107 * to the source version x.y.z (leading zeros in y and z). Beta versions
108 * were given the previous public release number plus a letter, until
109 * version 1.0.6j; from then on they were given the upcoming public
110 * release number plus "betaNN" or "rcN".
112 * Binary incompatibility exists only when applications make direct access
113 * to the info_ptr or png_ptr members through png.h, and the compiled
114 * application is loaded with a different version of the library.
116 * DLLNUM will change each time there are forward or backward changes
117 * in binary compatibility (e.g., when a new feature is added).
119 * See libpng.txt or libpng.3 for more information. The PNG specification
120 * is available as RFC 2083 <ftp://ftp.uu.net/graphics/png/documents/>
121 * and as a W3C Recommendation <http://www.w3.org/TR/REC.png.html>
125 * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
127 * If you modify libpng you may insert additional notices immediately following
130 * libpng versions 1.0.7, July 1, 2000, through 1.2.5, October 3, 2002, are
131 * Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are
132 * distributed according to the same disclaimer and license as libpng-1.0.6
133 * with the following individuals added to the list of Contributing Authors
135 * Simon-Pierre Cadieux
139 * and with the following additions to the disclaimer:
141 * There is no warranty against interference with your enjoyment of the
142 * library or against infringement. There is no warranty that our
143 * efforts or the library will fulfill any of your particular purposes
144 * or needs. This library is provided with all faults, and the entire
145 * risk of satisfactory quality, performance, accuracy, and effort is with
148 * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
149 * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson
150 * Distributed according to the same disclaimer and license as libpng-0.96,
151 * with the following individuals added to the list of Contributing Authors:
154 * Glenn Randers-Pehrson
157 * libpng versions 0.89, June 1996, through 0.96, May 1997, are
158 * Copyright (c) 1996, 1997 Andreas Dilger
159 * Distributed according to the same disclaimer and license as libpng-0.88,
160 * with the following individuals added to the list of Contributing Authors:
169 * libpng versions 0.5, May 1995, through 0.88, January 1996, are
170 * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
172 * For the purposes of this copyright and license, "Contributing Authors"
173 * is defined as the following set of individuals:
181 * The PNG Reference Library is supplied "AS IS". The Contributing Authors
182 * and Group 42, Inc. disclaim all warranties, expressed or implied,
183 * including, without limitation, the warranties of merchantability and of
184 * fitness for any purpose. The Contributing Authors and Group 42, Inc.
185 * assume no liability for direct, indirect, incidental, special, exemplary,
186 * or consequential damages, which may result from the use of the PNG
187 * Reference Library, even if advised of the possibility of such damage.
189 * Permission is hereby granted to use, copy, modify, and distribute this
190 * source code, or portions hereof, for any purpose, without fee, subject
191 * to the following restrictions:
193 * 1. The origin of this source code must not be misrepresented.
195 * 2. Altered versions must be plainly marked as such and
196 * must not be misrepresented as being the original source.
198 * 3. This Copyright notice may not be removed or altered from
199 * any source or altered source distribution.
201 * The Contributing Authors and Group 42, Inc. specifically permit, without
202 * fee, and encourage the use of this source code as a component to
203 * supporting the PNG file format in commercial products. If you use this
204 * source code in a product, acknowledgment is not required but would be
209 * A "png_get_copyright" function is available, for convenient use in "about"
210 * boxes and the like:
212 * printf("%s",png_get_copyright(NULL));
214 * Also, the PNG logo (in PNG format, of course) is supplied in the
215 * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
219 * Libpng is OSI Certified Open Source Software. OSI Certified is a
220 * certification mark of the Open Source Initiative.
224 * The contributing authors would like to thank all those who helped
225 * with testing, bug fixes, and patience. This wouldn't have been
226 * possible without all of you.
228 * Thanks to Frank J. T. Wojcik for helping with the documentation.
232 * Y2K compliance in libpng:
233 * =========================
237 * Since the PNG Development group is an ad-hoc body, we can't make
238 * an official declaration.
240 * This is your unofficial assurance that libpng from version 0.71 and
241 * upward through 1.2.5 are Y2K compliant. It is my belief that earlier
242 * versions were also Y2K compliant.
244 * Libpng only has three year fields. One is a 2-byte unsigned integer
245 * that will hold years up to 65535. The other two hold the date in text
246 * format, and will hold years up to 9999.
249 * "png_uint_16 year" in png_time_struct.
252 * "png_charp time_buffer" in png_struct and
253 * "near_time_buffer", which is a local character string in png.c.
255 * There are seven time-related functions:
256 * png.c: png_convert_to_rfc_1123() in png.c
257 * (formerly png_convert_to_rfc_1152() in error)
258 * png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
259 * png_convert_from_time_t() in pngwrite.c
260 * png_get_tIME() in pngget.c
261 * png_handle_tIME() in pngrutil.c, called in pngread.c
262 * png_set_tIME() in pngset.c
263 * png_write_tIME() in pngwutil.c, called in pngwrite.c
265 * All handle dates properly in a Y2K environment. The
266 * png_convert_from_time_t() function calls gmtime() to convert from system
267 * clock time, which returns (year - 1900), which we properly convert to
268 * the full 4-digit year. There is a possibility that applications using
269 * libpng are not passing 4-digit years into the png_convert_to_rfc_1123()
270 * function, or that they are incorrectly passing only a 2-digit year
271 * instead of "year - 1900" into the png_convert_from_struct_tm() function,
272 * but this is not under our control. The libpng documentation has always
273 * stated that it works with 4-digit years, and the APIs have been
274 * documented as such.
276 * The tIME chunk itself is also Y2K compliant. It uses a 2-byte unsigned
277 * integer to hold the year, and can hold years as large as 65535.
279 * zlib, upon which libpng depends, is also Y2K compliant. It contains
280 * no date-related code.
282 * Glenn Randers-Pehrson
284 * PNG Development Group
290 /* This is not the place to learn how to use libpng. The file libpng.txt
291 * describes how to use libpng, and the file example.c summarizes it
292 * with some code on which to build. This file is useful for looking
293 * at the actual function definitions and structure components.
296 /* Version information for png.h - this should match the version in png.c */
297 #define PNG_LIBPNG_VER_STRING "1.2.5"
299 #define PNG_LIBPNG_VER_SONUM 0
300 #define PNG_LIBPNG_VER_DLLNUM %DLLNUM%
302 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
303 #define PNG_LIBPNG_VER_MAJOR 1
304 #define PNG_LIBPNG_VER_MINOR 2
305 #define PNG_LIBPNG_VER_RELEASE 5
306 /* This should match the numeric part of the final component of
307 * PNG_LIBPNG_VER_STRING, omitting any leading zero: */
309 #define PNG_LIBPNG_VER_BUILD 0
311 #define PNG_LIBPNG_BUILD_ALPHA 1
312 #define PNG_LIBPNG_BUILD_BETA 2
313 #define PNG_LIBPNG_BUILD_RC 3
314 #define PNG_LIBPNG_BUILD_STABLE 4
315 #define PNG_LIBPNG_BUILD_TYPEMASK 7
316 #define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with STABLE only */
317 #define PNG_LIBPNG_BUILD_TYPE 4
319 /* Careful here. At one time, Guy wanted to use 082, but that would be octal.
320 * We must not include leading zeros.
321 * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only
322 * version 1.0.0 was mis-numbered 100 instead of 10000). From
323 * version 1.0.1 it's xxyyzz, where x=major, y=minor, z=release */
324 #define PNG_LIBPNG_VER 10205 /* 1.2.5 */
326 #ifndef PNG_VERSION_INFO_ONLY
328 /* include the compression library's header */
331 /* include all user configurable info, including optional assembler routines */
334 /* Inhibit C++ name-mangling for libpng functions but not for system calls. */
337 #endif /* __cplusplus */
339 /* This file is arranged in several sections. The first section contains
340 * structure and type definitions. The second section contains the external
341 * library functions, while the third has the internal library functions,
342 * which applications aren't expected to use directly.
345 #ifndef PNG_NO_TYPECAST_NULL
346 #define int_p_NULL (int *)NULL
347 #define png_bytep_NULL (png_bytep)NULL
348 #define png_bytepp_NULL (png_bytepp)NULL
349 #define png_doublep_NULL (png_doublep)NULL
350 #define png_error_ptr_NULL (png_error_ptr)NULL
351 #define png_flush_ptr_NULL (png_flush_ptr)NULL
352 #define png_free_ptr_NULL (png_free_ptr)NULL
353 #define png_infopp_NULL (png_infopp)NULL
354 #define png_malloc_ptr_NULL (png_malloc_ptr)NULL
355 #define png_read_status_ptr_NULL (png_read_status_ptr)NULL
356 #define png_rw_ptr_NULL (png_rw_ptr)NULL
357 #define png_structp_NULL (png_structp)NULL
358 #define png_uint_16p_NULL (png_uint_16p)NULL
359 #define png_voidp_NULL (png_voidp)NULL
360 #define png_write_status_ptr_NULL (png_write_status_ptr)NULL
362 #define int_p_NULL NULL
363 #define png_bytep_NULL NULL
364 #define png_bytepp_NULL NULL
365 #define png_doublep_NULL NULL
366 #define png_error_ptr_NULL NULL
367 #define png_flush_ptr_NULL NULL
368 #define png_free_ptr_NULL NULL
369 #define png_infopp_NULL NULL
370 #define png_malloc_ptr_NULL NULL
371 #define png_read_status_ptr_NULL NULL
372 #define png_rw_ptr_NULL NULL
373 #define png_structp_NULL NULL
374 #define png_uint_16p_NULL NULL
375 #define png_voidp_NULL NULL
376 #define png_write_status_ptr_NULL NULL
379 /* variables declared in png.c - only it needs to define PNG_NO_EXTERN */
380 #if !defined(PNG_NO_EXTERN) || defined(PNG_ALWAYS_EXTERN)
381 /* Version information for C files, stored in png.c. This had better match
384 #ifdef PNG_USE_GLOBAL_ARRAYS
385 PNG_EXPORT_VAR (const char) png_libpng_ver[18];
386 /* need room for 99.99.99beta99z */
388 #define png_libpng_ver png_get_header_ver(NULL)
391 #ifdef PNG_USE_GLOBAL_ARRAYS
392 /* This was removed in version 1.0.5c */
393 /* Structures to facilitate easy interlacing. See png.c for more details */
394 PNG_EXPORT_VAR (const int FARDATA) png_pass_start[7];
395 PNG_EXPORT_VAR (const int FARDATA) png_pass_inc[7];
396 PNG_EXPORT_VAR (const int FARDATA) png_pass_ystart[7];
397 PNG_EXPORT_VAR (const int FARDATA) png_pass_yinc[7];
398 PNG_EXPORT_VAR (const int FARDATA) png_pass_mask[7];
399 PNG_EXPORT_VAR (const int FARDATA) png_pass_dsp_mask[7];
400 #ifdef PNG_HAVE_ASSEMBLER_COMBINE_ROW
401 PNG_EXPORT_VAR (const int FARDATA) png_pass_width[7];
403 /* This isn't currently used. If you need it, see png.c for more details.
404 PNG_EXPORT_VAR (const int FARDATA) png_pass_height[7];
408 #endif /* PNG_NO_EXTERN */
410 /* Three color definitions. The order of the red, green, and blue, (and the
411 * exact size) is not important, although the size of the fields need to
412 * be png_byte or png_uint_16 (as defined below).
414 typedef struct png_color_struct
420 typedef png_color FAR * png_colorp;
421 typedef png_color FAR * FAR * png_colorpp;
423 typedef struct png_color_16_struct
425 png_byte index; /* used for palette files */
426 png_uint_16 red; /* for use in red green blue files */
429 png_uint_16 gray; /* for use in grayscale files */
431 typedef png_color_16 FAR * png_color_16p;
432 typedef png_color_16 FAR * FAR * png_color_16pp;
434 typedef struct png_color_8_struct
436 png_byte red; /* for use in red green blue files */
439 png_byte gray; /* for use in grayscale files */
440 png_byte alpha; /* for alpha channel files */
442 typedef png_color_8 FAR * png_color_8p;
443 typedef png_color_8 FAR * FAR * png_color_8pp;
446 * The following two structures are used for the in-core representation
449 typedef struct png_sPLT_entry_struct
455 png_uint_16 frequency;
457 typedef png_sPLT_entry FAR * png_sPLT_entryp;
458 typedef png_sPLT_entry FAR * FAR * png_sPLT_entrypp;
460 /* When the depth of the sPLT palette is 8 bits, the color and alpha samples
461 * occupy the LSB of their respective members, and the MSB of each member
462 * is zero-filled. The frequency member always occupies the full 16 bits.
465 typedef struct png_sPLT_struct
467 png_charp name; /* palette name */
468 png_byte depth; /* depth of palette samples */
469 png_sPLT_entryp entries; /* palette entries */
470 png_int_32 nentries; /* number of palette entries */
472 typedef png_sPLT_t FAR * png_sPLT_tp;
473 typedef png_sPLT_t FAR * FAR * png_sPLT_tpp;
475 #ifdef PNG_TEXT_SUPPORTED
476 /* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,
477 * and whether that contents is compressed or not. The "key" field
478 * points to a regular zero-terminated C string. The "text", "lang", and
479 * "lang_key" fields can be regular C strings, empty strings, or NULL pointers.
480 * However, the * structure returned by png_get_text() will always contain
481 * regular zero-terminated C strings (possibly empty), never NULL pointers,
482 * so they can be safely used in printf() and other string-handling functions.
484 typedef struct png_text_struct
486 int compression; /* compression value:
491 png_charp key; /* keyword, 1-79 character description of "text" */
492 png_charp text; /* comment, may be an empty string (ie "")
494 png_size_t text_length; /* length of the text string */
495 #ifdef PNG_iTXt_SUPPORTED
496 png_size_t itxt_length; /* length of the itxt string */
497 png_charp lang; /* language code, 0-79 characters
499 png_charp lang_key; /* keyword translated UTF-8 string, 0 or more
500 chars or a NULL pointer */
503 typedef png_text FAR * png_textp;
504 typedef png_text FAR * FAR * png_textpp;
507 /* Supported compression types for text in PNG files (tEXt, and zTXt).
508 * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */
509 #define PNG_TEXT_COMPRESSION_NONE_WR -3
510 #define PNG_TEXT_COMPRESSION_zTXt_WR -2
511 #define PNG_TEXT_COMPRESSION_NONE -1
512 #define PNG_TEXT_COMPRESSION_zTXt 0
513 #define PNG_ITXT_COMPRESSION_NONE 1
514 #define PNG_ITXT_COMPRESSION_zTXt 2
515 #define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */
517 /* png_time is a way to hold the time in an machine independent way.
518 * Two conversions are provided, both from time_t and struct tm. There
519 * is no portable way to convert to either of these structures, as far
520 * as I know. If you know of a portable way, send it to me. As a side
521 * note - PNG has always been Year 2000 compliant!
523 typedef struct png_time_struct
525 png_uint_16 year; /* full year, as in, 1995 */
526 png_byte month; /* month of year, 1 - 12 */
527 png_byte day; /* day of month, 1 - 31 */
528 png_byte hour; /* hour of day, 0 - 23 */
529 png_byte minute; /* minute of hour, 0 - 59 */
530 png_byte second; /* second of minute, 0 - 60 (for leap seconds) */
532 typedef png_time FAR * png_timep;
533 typedef png_time FAR * FAR * png_timepp;
535 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
536 /* png_unknown_chunk is a structure to hold queued chunks for which there is
537 * no specific support. The idea is that we can use this to queue
538 * up private chunks for output even though the library doesn't actually
539 * know about their semantics.
541 typedef struct png_unknown_chunk_t
547 /* libpng-using applications should NOT directly modify this byte. */
548 png_byte location; /* mode of operation at read time */
551 typedef png_unknown_chunk FAR * png_unknown_chunkp;
552 typedef png_unknown_chunk FAR * FAR * png_unknown_chunkpp;
555 /* png_info is a structure that holds the information in a PNG file so
556 * that the application can find out the characteristics of the image.
557 * If you are reading the file, this structure will tell you what is
558 * in the PNG file. If you are writing the file, fill in the information
559 * you want to put into the PNG file, then call png_write_info().
560 * The names chosen should be very close to the PNG specification, so
561 * consult that document for information about the meaning of each field.
563 * With libpng < 0.95, it was only possible to directly set and read the
564 * the values in the png_info_struct, which meant that the contents and
565 * order of the values had to remain fixed. With libpng 0.95 and later,
566 * however, there are now functions that abstract the contents of
567 * png_info_struct from the application, so this makes it easier to use
568 * libpng with dynamic libraries, and even makes it possible to use
569 * libraries that don't have all of the libpng ancillary chunk-handing
572 * In any case, the order of the parameters in png_info_struct should NOT
573 * be changed for as long as possible to keep compatibility with applications
574 * that use the old direct-access method with png_info_struct.
576 * The following members may have allocated storage attached that should be
577 * cleaned up before the structure is discarded: palette, trans, text,
578 * pcal_purpose, pcal_units, pcal_params, hist, iccp_name, iccp_profile,
579 * splt_palettes, scal_unit, row_pointers, and unknowns. By default, these
580 * are automatically freed when the info structure is deallocated, if they were
581 * allocated internally by libpng. This behavior can be changed by means
582 * of the png_data_freer() function.
584 * More allocation details: all the chunk-reading functions that
585 * change these members go through the corresponding png_set_*
586 * functions. A function to clear these members is available: see
587 * png_free_data(). The png_set_* functions do not depend on being
588 * able to point info structure members to any of the storage they are
589 * passed (they make their own copies), EXCEPT that the png_set_text
590 * functions use the same storage passed to them in the text_ptr or
591 * itxt_ptr structure argument, and the png_set_rows and png_set_unknowns
592 * functions do not make their own copies.
594 typedef struct png_info_struct
596 /* the following are necessary for every PNG file */
597 png_uint_32 width; /* width of image in pixels (from IHDR) */
598 png_uint_32 height; /* height of image in pixels (from IHDR) */
599 png_uint_32 valid; /* valid chunk data (see PNG_INFO_ below) */
600 png_uint_32 rowbytes; /* bytes needed to hold an untransformed row */
601 png_colorp palette; /* array of color values (valid & PNG_INFO_PLTE) */
602 png_uint_16 num_palette; /* number of color entries in "palette" (PLTE) */
603 png_uint_16 num_trans; /* number of transparent palette color (tRNS) */
604 png_byte bit_depth; /* 1, 2, 4, 8, or 16 bits/channel (from IHDR) */
605 png_byte color_type; /* see PNG_COLOR_TYPE_ below (from IHDR) */
606 /* The following three should have been named *_method not *_type */
607 png_byte compression_type; /* must be PNG_COMPRESSION_TYPE_BASE (IHDR) */
608 png_byte filter_type; /* must be PNG_FILTER_TYPE_BASE (from IHDR) */
609 png_byte interlace_type; /* One of PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
611 /* The following is informational only on read, and not used on writes. */
612 png_byte channels; /* number of data channels per pixel (1, 2, 3, 4) */
613 png_byte pixel_depth; /* number of bits per pixel */
614 png_byte spare_byte; /* to align the data, and for future use */
615 png_byte signature[8]; /* magic bytes read by libpng from start of file */
617 /* The rest of the data is optional. If you are reading, check the
618 * valid field to see if the information in these are valid. If you
619 * are writing, set the valid field to those chunks you want written,
620 * and initialize the appropriate fields below.
623 #if defined(PNG_gAMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
624 /* The gAMA chunk describes the gamma characteristics of the system
625 * on which the image was created, normally in the range [1.0, 2.5].
626 * Data is valid if (valid & PNG_INFO_gAMA) is non-zero.
628 float gamma; /* gamma value of image, if (valid & PNG_INFO_gAMA) */
631 #if defined(PNG_sRGB_SUPPORTED)
633 /* Data valid if (valid & PNG_INFO_sRGB) non-zero. */
634 png_byte srgb_intent; /* sRGB rendering intent [0, 1, 2, or 3] */
637 #if defined(PNG_TEXT_SUPPORTED)
638 /* The tEXt, and zTXt chunks contain human-readable textual data in
639 * uncompressed, compressed, and optionally compressed forms, respectively.
640 * The data in "text" is an array of pointers to uncompressed,
641 * null-terminated C strings. Each chunk has a keyword that describes the
642 * textual data contained in that chunk. Keywords are not required to be
643 * unique, and the text string may be empty. Any number of text chunks may
646 int num_text; /* number of comments read/to write */
647 int max_text; /* current size of text array */
648 png_textp text; /* array of comments read/to write */
649 #endif /* PNG_TEXT_SUPPORTED */
651 #if defined(PNG_tIME_SUPPORTED)
652 /* The tIME chunk holds the last time the displayed image data was
653 * modified. See the png_time struct for the contents of this struct.
658 #if defined(PNG_sBIT_SUPPORTED)
659 /* The sBIT chunk specifies the number of significant high-order bits
660 * in the pixel data. Values are in the range [1, bit_depth], and are
661 * only specified for the channels in the pixel data. The contents of
662 * the low-order bits is not specified. Data is valid if
663 * (valid & PNG_INFO_sBIT) is non-zero.
665 png_color_8 sig_bit; /* significant bits in color channels */
668 #if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_EXPAND_SUPPORTED) || \
669 defined(PNG_READ_BACKGROUND_SUPPORTED)
670 /* The tRNS chunk supplies transparency data for paletted images and
671 * other image types that don't need a full alpha channel. There are
672 * "num_trans" transparency values for a paletted image, stored in the
673 * same order as the palette colors, starting from index 0. Values
674 * for the data are in the range [0, 255], ranging from fully transparent
675 * to fully opaque, respectively. For non-paletted images, there is a
676 * single color specified that should be treated as fully transparent.
677 * Data is valid if (valid & PNG_INFO_tRNS) is non-zero.
679 png_bytep trans; /* transparent values for paletted image */
680 png_color_16 trans_values; /* transparent color for non-palette image */
683 #if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
684 /* The bKGD chunk gives the suggested image background color if the
685 * display program does not have its own background color and the image
686 * is needs to composited onto a background before display. The colors
687 * in "background" are normally in the same color space/depth as the
688 * pixel data. Data is valid if (valid & PNG_INFO_bKGD) is non-zero.
690 png_color_16 background;
693 #if defined(PNG_oFFs_SUPPORTED)
694 /* The oFFs chunk gives the offset in "offset_unit_type" units rightwards
695 * and downwards from the top-left corner of the display, page, or other
696 * application-specific co-ordinate space. See the PNG_OFFSET_ defines
697 * below for the unit types. Valid if (valid & PNG_INFO_oFFs) non-zero.
699 png_int_32 x_offset; /* x offset on page */
700 png_int_32 y_offset; /* y offset on page */
701 png_byte offset_unit_type; /* offset units type */
704 #if defined(PNG_pHYs_SUPPORTED)
705 /* The pHYs chunk gives the physical pixel density of the image for
706 * display or printing in "phys_unit_type" units (see PNG_RESOLUTION_
707 * defines below). Data is valid if (valid & PNG_INFO_pHYs) is non-zero.
709 png_uint_32 x_pixels_per_unit; /* horizontal pixel density */
710 png_uint_32 y_pixels_per_unit; /* vertical pixel density */
711 png_byte phys_unit_type; /* resolution type (see PNG_RESOLUTION_ below) */
714 #if defined(PNG_hIST_SUPPORTED)
715 /* The hIST chunk contains the relative frequency or importance of the
716 * various palette entries, so that a viewer can intelligently select a
717 * reduced-color palette, if required. Data is an array of "num_palette"
718 * values in the range [0,65535]. Data valid if (valid & PNG_INFO_hIST)
724 #ifdef PNG_cHRM_SUPPORTED
725 /* The cHRM chunk describes the CIE color characteristics of the monitor
726 * on which the PNG was created. This data allows the viewer to do gamut
727 * mapping of the input image to ensure that the viewer sees the same
728 * colors in the image as the creator. Values are in the range
729 * [0.0, 0.8]. Data valid if (valid & PNG_INFO_cHRM) non-zero.
731 #ifdef PNG_FLOATING_POINT_SUPPORTED
743 #if defined(PNG_pCAL_SUPPORTED)
744 /* The pCAL chunk describes a transformation between the stored pixel
745 * values and original physical data values used to create the image.
746 * The integer range [0, 2^bit_depth - 1] maps to the floating-point
747 * range given by [pcal_X0, pcal_X1], and are further transformed by a
748 * (possibly non-linear) transformation function given by "pcal_type"
749 * and "pcal_params" into "pcal_units". Please see the PNG_EQUATION_
750 * defines below, and the PNG-Group's PNG extensions document for a
751 * complete description of the transformations and how they should be
752 * implemented, and for a description of the ASCII parameter strings.
753 * Data values are valid if (valid & PNG_INFO_pCAL) non-zero.
755 png_charp pcal_purpose; /* pCAL chunk description string */
756 png_int_32 pcal_X0; /* minimum value */
757 png_int_32 pcal_X1; /* maximum value */
758 png_charp pcal_units; /* Latin-1 string giving physical units */
759 png_charpp pcal_params; /* ASCII strings containing parameter values */
760 png_byte pcal_type; /* equation type (see PNG_EQUATION_ below) */
761 png_byte pcal_nparams; /* number of parameters given in pcal_params */
764 /* New members added in libpng-1.0.6 */
765 #ifdef PNG_FREE_ME_SUPPORTED
766 png_uint_32 free_me; /* flags items libpng is responsible for freeing */
769 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
770 /* storage for unknown chunks that the library doesn't recognize. */
771 png_unknown_chunkp unknown_chunks;
772 png_size_t unknown_chunks_num;
775 #if defined(PNG_iCCP_SUPPORTED)
776 /* iCCP chunk data. */
777 png_charp iccp_name; /* profile name */
778 png_charp iccp_profile; /* International Color Consortium profile data */
779 /* Note to maintainer: should be png_bytep */
780 png_uint_32 iccp_proflen; /* ICC profile data length */
781 png_byte iccp_compression; /* Always zero */
784 #if defined(PNG_sPLT_SUPPORTED)
785 /* data on sPLT chunks (there may be more than one). */
786 png_sPLT_tp splt_palettes;
787 png_uint_32 splt_palettes_num;
790 #if defined(PNG_sCAL_SUPPORTED)
791 /* The sCAL chunk describes the actual physical dimensions of the
792 * subject matter of the graphic. The chunk contains a unit specification
793 * a byte value, and two ASCII strings representing floating-point
794 * values. The values are width and height corresponsing to one pixel
795 * in the image. This external representation is converted to double
796 * here. Data values are valid if (valid & PNG_INFO_sCAL) is non-zero.
798 png_byte scal_unit; /* unit of physical scale */
799 #ifdef PNG_FLOATING_POINT_SUPPORTED
800 double scal_pixel_width; /* width of one pixel */
801 double scal_pixel_height; /* height of one pixel */
803 #ifdef PNG_FIXED_POINT_SUPPORTED
804 png_charp scal_s_width; /* string containing height */
805 png_charp scal_s_height; /* string containing width */
809 #if defined(PNG_INFO_IMAGE_SUPPORTED)
810 /* Memory has been allocated if (valid & PNG_ALLOCATED_INFO_ROWS) non-zero */
811 /* Data valid if (valid & PNG_INFO_IDAT) non-zero */
812 png_bytepp row_pointers; /* the image bits */
815 #if defined(PNG_FIXED_POINT_SUPPORTED) && defined(PNG_gAMA_SUPPORTED)
816 png_fixed_point int_gamma; /* gamma of image, if (valid & PNG_INFO_gAMA) */
819 #if defined(PNG_cHRM_SUPPORTED) && defined(PNG_FIXED_POINT_SUPPORTED)
820 png_fixed_point int_x_white;
821 png_fixed_point int_y_white;
822 png_fixed_point int_x_red;
823 png_fixed_point int_y_red;
824 png_fixed_point int_x_green;
825 png_fixed_point int_y_green;
826 png_fixed_point int_x_blue;
827 png_fixed_point int_y_blue;
832 typedef png_info FAR * png_infop;
833 typedef png_info FAR * FAR * png_infopp;
835 /* Maximum positive integer used in PNG is (2^31)-1 */
836 #define PNG_MAX_UINT ((png_uint_32)0x7fffffffL)
838 /* These describe the color_type field in png_info. */
839 /* color type masks */
840 #define PNG_COLOR_MASK_PALETTE 1
841 #define PNG_COLOR_MASK_COLOR 2
842 #define PNG_COLOR_MASK_ALPHA 4
844 /* color types. Note that not all combinations are legal */
845 #define PNG_COLOR_TYPE_GRAY 0
846 #define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
847 #define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR)
848 #define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
849 #define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
851 #define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA
852 #define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA
854 /* This is for compression type. PNG 1.0-1.2 only define the single type. */
855 #define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */
856 #define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE
858 /* This is for filter type. PNG 1.0-1.2 only define the single type. */
859 #define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */
860 #define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */
861 #define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE
863 /* These are for the interlacing type. These values should NOT be changed. */
864 #define PNG_INTERLACE_NONE 0 /* Non-interlaced image */
865 #define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */
866 #define PNG_INTERLACE_LAST 2 /* Not a valid value */
868 /* These are for the oFFs chunk. These values should NOT be changed. */
869 #define PNG_OFFSET_PIXEL 0 /* Offset in pixels */
870 #define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */
871 #define PNG_OFFSET_LAST 2 /* Not a valid value */
873 /* These are for the pCAL chunk. These values should NOT be changed. */
874 #define PNG_EQUATION_LINEAR 0 /* Linear transformation */
875 #define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */
876 #define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */
877 #define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */
878 #define PNG_EQUATION_LAST 4 /* Not a valid value */
880 /* These are for the sCAL chunk. These values should NOT be changed. */
881 #define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */
882 #define PNG_SCALE_METER 1 /* meters per pixel */
883 #define PNG_SCALE_RADIAN 2 /* radians per pixel */
884 #define PNG_SCALE_LAST 3 /* Not a valid value */
886 /* These are for the pHYs chunk. These values should NOT be changed. */
887 #define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */
888 #define PNG_RESOLUTION_METER 1 /* pixels/meter */
889 #define PNG_RESOLUTION_LAST 2 /* Not a valid value */
891 /* These are for the sRGB chunk. These values should NOT be changed. */
892 #define PNG_sRGB_INTENT_PERCEPTUAL 0
893 #define PNG_sRGB_INTENT_RELATIVE 1
894 #define PNG_sRGB_INTENT_SATURATION 2
895 #define PNG_sRGB_INTENT_ABSOLUTE 3
896 #define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */
898 /* This is for text chunks */
899 #define PNG_KEYWORD_MAX_LENGTH 79
901 /* Maximum number of entries in PLTE/sPLT/tRNS arrays */
902 #define PNG_MAX_PALETTE_LENGTH 256
904 /* These determine if an ancillary chunk's data has been successfully read
905 * from the PNG header, or if the application has filled in the corresponding
906 * data in the info_struct to be written into the output file. The values
907 * of the PNG_INFO_<chunk> defines should NOT be changed.
909 #define PNG_INFO_gAMA 0x0001
910 #define PNG_INFO_sBIT 0x0002
911 #define PNG_INFO_cHRM 0x0004
912 #define PNG_INFO_PLTE 0x0008
913 #define PNG_INFO_tRNS 0x0010
914 #define PNG_INFO_bKGD 0x0020
915 #define PNG_INFO_hIST 0x0040
916 #define PNG_INFO_pHYs 0x0080
917 #define PNG_INFO_oFFs 0x0100
918 #define PNG_INFO_tIME 0x0200
919 #define PNG_INFO_pCAL 0x0400
920 #define PNG_INFO_sRGB 0x0800 /* GR-P, 0.96a */
921 #define PNG_INFO_iCCP 0x1000 /* ESR, 1.0.6 */
922 #define PNG_INFO_sPLT 0x2000 /* ESR, 1.0.6 */
923 #define PNG_INFO_sCAL 0x4000 /* ESR, 1.0.6 */
924 #define PNG_INFO_IDAT 0x8000L /* ESR, 1.0.6 */
926 /* This is used for the transformation routines, as some of them
927 * change these values for the row. It also should enable using
928 * the routines for other purposes.
930 typedef struct png_row_info_struct
932 png_uint_32 width; /* width of row */
933 png_uint_32 rowbytes; /* number of bytes in row */
934 png_byte color_type; /* color type of row */
935 png_byte bit_depth; /* bit depth of row */
936 png_byte channels; /* number of channels (1, 2, 3, or 4) */
937 png_byte pixel_depth; /* bits per pixel (depth * channels) */
940 typedef png_row_info FAR * png_row_infop;
941 typedef png_row_info FAR * FAR * png_row_infopp;
943 /* These are the function types for the I/O functions and for the functions
944 * that allow the user to override the default I/O functions with his or her
945 * own. The png_error_ptr type should match that of user-supplied warning
946 * and error functions, while the png_rw_ptr type should match that of the
947 * user read/write data functions.
949 typedef struct png_struct_def png_struct;
950 typedef png_struct FAR * png_structp;
952 typedef void (PNGAPI *png_error_ptr) PNGARG((png_structp, png_const_charp));
953 typedef void (PNGAPI *png_rw_ptr) PNGARG((png_structp, png_bytep, png_size_t));
954 typedef void (PNGAPI *png_flush_ptr) PNGARG((png_structp));
955 typedef void (PNGAPI *png_read_status_ptr) PNGARG((png_structp, png_uint_32,
957 typedef void (PNGAPI *png_write_status_ptr) PNGARG((png_structp, png_uint_32,
960 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
961 typedef void (PNGAPI *png_progressive_info_ptr) PNGARG((png_structp, png_infop));
962 typedef void (PNGAPI *png_progressive_end_ptr) PNGARG((png_structp, png_infop));
963 typedef void (PNGAPI *png_progressive_row_ptr) PNGARG((png_structp, png_bytep,
967 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
968 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
969 defined(PNG_LEGACY_SUPPORTED)
970 typedef void (PNGAPI *png_user_transform_ptr) PNGARG((png_structp,
971 png_row_infop, png_bytep));
974 #if defined(PNG_USER_CHUNKS_SUPPORTED)
975 typedef int (PNGAPI *png_user_chunk_ptr) PNGARG((png_structp, png_unknown_chunkp));
977 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
978 typedef void (PNGAPI *png_unknown_chunk_ptr) PNGARG((png_structp));
981 /* Transform masks for the high-level interface */
982 #define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */
983 #define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */
984 #define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */
985 #define PNG_TRANSFORM_PACKING 0x0004 /* read and write */
986 #define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */
987 #define PNG_TRANSFORM_EXPAND 0x0010 /* read only */
988 #define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */
989 #define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */
990 #define PNG_TRANSFORM_BGR 0x0080 /* read and write */
991 #define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */
992 #define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */
993 #define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */
994 #define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* WRITE only */
996 /* Flags for MNG supported features */
997 #define PNG_FLAG_MNG_EMPTY_PLTE 0x01
998 #define PNG_FLAG_MNG_FILTER_64 0x04
999 #define PNG_ALL_MNG_FEATURES 0x05
1001 typedef png_voidp (*png_malloc_ptr) PNGARG((png_structp, png_size_t));
1002 typedef void (*png_free_ptr) PNGARG((png_structp, png_voidp));
1004 /* The structure that holds the information to read and write PNG files.
1005 * The only people who need to care about what is inside of this are the
1006 * people who will be modifying the library for their own special needs.
1007 * It should NOT be accessed directly by an application, except to store
1011 struct png_struct_def
1013 #ifdef PNG_SETJMP_SUPPORTED
1014 jmp_buf jmpbuf; /* used in png_error */
1016 png_error_ptr error_fn; /* function for printing errors and aborting */
1017 png_error_ptr warning_fn; /* function for printing warnings */
1018 png_voidp error_ptr; /* user supplied struct for error functions */
1019 png_rw_ptr write_data_fn; /* function for writing output data */
1020 png_rw_ptr read_data_fn; /* function for reading input data */
1021 png_voidp io_ptr; /* ptr to application struct for I/O functions */
1023 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
1024 png_user_transform_ptr read_user_transform_fn; /* user read transform */
1027 #if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
1028 png_user_transform_ptr write_user_transform_fn; /* user write transform */
1031 /* These were added in libpng-1.0.2 */
1032 #if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
1033 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
1034 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
1035 png_voidp user_transform_ptr; /* user supplied struct for user transform */
1036 png_byte user_transform_depth; /* bit depth of user transformed pixels */
1037 png_byte user_transform_channels; /* channels in user transformed pixels */
1041 png_uint_32 mode; /* tells us where we are in the PNG file */
1042 png_uint_32 flags; /* flags indicating various things to libpng */
1043 png_uint_32 transformations; /* which transformations to perform */
1045 z_stream zstream; /* pointer to decompression structure (below) */
1046 png_bytep zbuf; /* buffer for zlib */
1047 png_size_t zbuf_size; /* size of zbuf */
1048 int zlib_level; /* holds zlib compression level */
1049 int zlib_method; /* holds zlib compression method */
1050 int zlib_window_bits; /* holds zlib compression window bits */
1051 int zlib_mem_level; /* holds zlib compression memory level */
1052 int zlib_strategy; /* holds zlib compression strategy */
1054 png_uint_32 width; /* width of image in pixels */
1055 png_uint_32 height; /* height of image in pixels */
1056 png_uint_32 num_rows; /* number of rows in current pass */
1057 png_uint_32 usr_width; /* width of row at start of write */
1058 png_uint_32 rowbytes; /* size of row in bytes */
1059 png_uint_32 irowbytes; /* size of current interlaced row in bytes */
1060 png_uint_32 iwidth; /* width of current interlaced row in pixels */
1061 png_uint_32 row_number; /* current row in interlace pass */
1062 png_bytep prev_row; /* buffer to save previous (unfiltered) row */
1063 png_bytep row_buf; /* buffer to save current (unfiltered) row */
1064 png_bytep sub_row; /* buffer to save "sub" row when filtering */
1065 png_bytep up_row; /* buffer to save "up" row when filtering */
1066 png_bytep avg_row; /* buffer to save "avg" row when filtering */
1067 png_bytep paeth_row; /* buffer to save "Paeth" row when filtering */
1068 png_row_info row_info; /* used for transformation routines */
1070 png_uint_32 idat_size; /* current IDAT size for read */
1071 png_uint_32 crc; /* current chunk CRC value */
1072 png_colorp palette; /* palette from the input file */
1073 png_uint_16 num_palette; /* number of color entries in palette */
1074 png_uint_16 num_trans; /* number of transparency values */
1075 png_byte chunk_name[5]; /* null-terminated name of current chunk */
1076 png_byte compression; /* file compression type (always 0) */
1077 png_byte filter; /* file filter type (always 0) */
1078 png_byte interlaced; /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
1079 png_byte pass; /* current interlace pass (0 - 6) */
1080 png_byte do_filter; /* row filter flags (see PNG_FILTER_ below ) */
1081 png_byte color_type; /* color type of file */
1082 png_byte bit_depth; /* bit depth of file */
1083 png_byte usr_bit_depth; /* bit depth of users row */
1084 png_byte pixel_depth; /* number of bits per pixel */
1085 png_byte channels; /* number of channels in file */
1086 png_byte usr_channels; /* channels at start of write */
1087 png_byte sig_bytes; /* magic bytes read/written from start of file */
1089 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
1090 #ifdef PNG_LEGACY_SUPPORTED
1091 png_byte filler; /* filler byte for pixel expansion */
1093 png_uint_16 filler; /* filler bytes for pixel expansion */
1097 #if defined(PNG_bKGD_SUPPORTED)
1098 png_byte background_gamma_type;
1099 # ifdef PNG_FLOATING_POINT_SUPPORTED
1100 float background_gamma;
1102 png_color_16 background; /* background color in screen gamma space */
1103 #if defined(PNG_READ_GAMMA_SUPPORTED)
1104 png_color_16 background_1; /* background normalized to gamma 1.0 */
1106 #endif /* PNG_bKGD_SUPPORTED */
1108 #if defined(PNG_WRITE_FLUSH_SUPPORTED)
1109 png_flush_ptr output_flush_fn;/* Function for flushing output */
1110 png_uint_32 flush_dist; /* how many rows apart to flush, 0 - no flush */
1111 png_uint_32 flush_rows; /* number of rows written since last flush */
1114 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1115 int gamma_shift; /* number of "insignificant" bits 16-bit gamma */
1116 #ifdef PNG_FLOATING_POINT_SUPPORTED
1117 float gamma; /* file gamma value */
1118 float screen_gamma; /* screen gamma value (display_exponent) */
1122 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1123 png_bytep gamma_table; /* gamma table for 8-bit depth files */
1124 png_bytep gamma_from_1; /* converts from 1.0 to screen */
1125 png_bytep gamma_to_1; /* converts from file to 1.0 */
1126 png_uint_16pp gamma_16_table; /* gamma table for 16-bit depth files */
1127 png_uint_16pp gamma_16_from_1; /* converts from 1.0 to screen */
1128 png_uint_16pp gamma_16_to_1; /* converts from file to 1.0 */
1131 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_sBIT_SUPPORTED)
1132 png_color_8 sig_bit; /* significant bits in each available channel */
1135 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
1136 png_color_8 shift; /* shift for significant bit tranformation */
1139 #if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \
1140 || defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1141 png_bytep trans; /* transparency values for paletted files */
1142 png_color_16 trans_values; /* transparency values for non-paletted files */
1145 png_read_status_ptr read_row_fn; /* called after each row is decoded */
1146 png_write_status_ptr write_row_fn; /* called after each row is encoded */
1147 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1148 png_progressive_info_ptr info_fn; /* called after header data fully read */
1149 png_progressive_row_ptr row_fn; /* called after each prog. row is decoded */
1150 png_progressive_end_ptr end_fn; /* called after image is complete */
1151 png_bytep save_buffer_ptr; /* current location in save_buffer */
1152 png_bytep save_buffer; /* buffer for previously read data */
1153 png_bytep current_buffer_ptr; /* current location in current_buffer */
1154 png_bytep current_buffer; /* buffer for recently used data */
1155 png_uint_32 push_length; /* size of current input chunk */
1156 png_uint_32 skip_length; /* bytes to skip in input data */
1157 png_size_t save_buffer_size; /* amount of data now in save_buffer */
1158 png_size_t save_buffer_max; /* total size of save_buffer */
1159 png_size_t buffer_size; /* total amount of available input data */
1160 png_size_t current_buffer_size; /* amount of data now in current_buffer */
1161 int process_mode; /* what push library is currently doing */
1162 int cur_palette; /* current push library palette index */
1164 # if defined(PNG_TEXT_SUPPORTED)
1165 png_size_t current_text_size; /* current size of text input data */
1166 png_size_t current_text_left; /* how much text left to read in input */
1167 png_charp current_text; /* current text chunk buffer */
1168 png_charp current_text_ptr; /* current location in current_text */
1169 # endif /* PNG_PROGRESSIVE_READ_SUPPORTED && PNG_TEXT_SUPPORTED */
1171 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
1173 #if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
1174 /* for the Borland special 64K segment handler */
1175 png_bytepp offset_table_ptr;
1176 png_bytep offset_table;
1177 png_uint_16 offset_table_number;
1178 png_uint_16 offset_table_count;
1179 png_uint_16 offset_table_count_free;
1182 #if defined(PNG_READ_DITHER_SUPPORTED)
1183 png_bytep palette_lookup; /* lookup table for dithering */
1184 png_bytep dither_index; /* index translation for palette files */
1187 #if defined(PNG_READ_DITHER_SUPPORTED) || defined(PNG_hIST_SUPPORTED)
1188 png_uint_16p hist; /* histogram */
1191 #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
1192 png_byte heuristic_method; /* heuristic for row filter selection */
1193 png_byte num_prev_filters; /* number of weights for previous rows */
1194 png_bytep prev_filters; /* filter type(s) of previous row(s) */
1195 png_uint_16p filter_weights; /* weight(s) for previous line(s) */
1196 png_uint_16p inv_filter_weights; /* 1/weight(s) for previous line(s) */
1197 png_uint_16p filter_costs; /* relative filter calculation cost */
1198 png_uint_16p inv_filter_costs; /* 1/relative filter calculation cost */
1201 #if defined(PNG_TIME_RFC1123_SUPPORTED)
1202 png_charp time_buffer; /* String to hold RFC 1123 time text */
1205 /* New members added in libpng-1.0.6 */
1207 #ifdef PNG_FREE_ME_SUPPORTED
1208 png_uint_32 free_me; /* flags items libpng is responsible for freeing */
1211 #if defined(PNG_USER_CHUNKS_SUPPORTED)
1212 png_voidp user_chunk_ptr;
1213 png_user_chunk_ptr read_user_chunk_fn; /* user read chunk handler */
1216 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
1218 png_bytep chunk_list;
1221 /* New members added in libpng-1.0.3 */
1222 #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
1223 png_byte rgb_to_gray_status;
1224 /* These were changed from png_byte in libpng-1.0.6 */
1225 png_uint_16 rgb_to_gray_red_coeff;
1226 png_uint_16 rgb_to_gray_green_coeff;
1227 png_uint_16 rgb_to_gray_blue_coeff;
1230 /* New member added in libpng-1.0.4 (renamed in 1.0.9) */
1231 #if defined(PNG_MNG_FEATURES_SUPPORTED) || \
1232 defined(PNG_READ_EMPTY_PLTE_SUPPORTED) || \
1233 defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
1234 /* changed from png_byte to png_uint_32 at version 1.2.0 */
1236 png_byte mng_features_permitted;
1238 png_uint_32 mng_features_permitted;
1239 #endif /* PNG_1_0_X */
1242 /* New member added in libpng-1.0.7 */
1243 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1244 png_fixed_point int_gamma;
1247 /* New member added in libpng-1.0.9, ifdef'ed out in 1.0.12, enabled in 1.2.0 */
1248 #if defined(PNG_MNG_FEATURES_SUPPORTED)
1249 png_byte filter_type;
1252 #if defined(PNG_1_0_X) || (defined(PNG_DEBUG) && defined(PNG_USE_PNGGCCRD))
1253 /* New member added in libpng-1.0.10, ifdef'ed out in 1.2.0 */
1254 png_uint_32 row_buf_size;
1257 /* New members added in libpng-1.2.0 */
1258 #if !defined(PNG_1_0_X) && defined(PNG_ASSEMBLER_CODE_SUPPORTED)
1259 png_byte mmx_bitdepth_threshold;
1260 png_uint_32 mmx_rowbytes_threshold;
1261 png_uint_32 asm_flags;
1264 /* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */
1265 #ifdef PNG_USER_MEM_SUPPORTED
1266 png_voidp mem_ptr; /* user supplied struct for mem functions */
1267 png_malloc_ptr malloc_fn; /* function for allocating memory */
1268 png_free_ptr free_fn; /* function for freeing memory */
1271 /* New member added in libpng-1.0.13 and 1.2.0 */
1272 png_bytep big_row_buf; /* buffer to save current (unfiltered) row */
1274 #if defined(PNG_READ_DITHER_SUPPORTED)
1275 /* The following three members were added at version 1.0.14 and 1.2.4 */
1276 png_bytep dither_sort; /* working sort array */
1277 png_bytep index_to_palette; /* where the original index currently is */
1278 /* in the palette */
1279 png_bytep palette_to_index; /* which original index points to this */
1286 /* This prevents a compiler error in png.c if png.c and png.h are both at
1289 typedef png_structp version_1_2_5;
1291 typedef png_struct FAR * FAR * png_structpp;
1293 /* Here are the function definitions most commonly used. This is not
1294 * the place to find out how to use libpng. See libpng.txt for the
1295 * full explanation, see example.c for the summary. This just provides
1296 * a simple one line description of the use of each function.
1299 /* Returns the version number of the library */
1300 extern PNG_EXPORT(png_uint_32,png_access_version_number) PNGARG((void));
1302 /* Tell lib we have already handled the first <num_bytes> magic bytes.
1303 * Handling more than 8 bytes from the beginning of the file is an error.
1305 extern PNG_EXPORT(void,png_set_sig_bytes) PNGARG((png_structp png_ptr,
1308 /* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
1309 * PNG file. Returns zero if the supplied bytes match the 8-byte PNG
1310 * signature, and non-zero otherwise. Having num_to_check == 0 or
1311 * start > 7 will always fail (ie return non-zero).
1313 extern PNG_EXPORT(int,png_sig_cmp) PNGARG((png_bytep sig, png_size_t start,
1314 png_size_t num_to_check));
1316 /* Simple signature checking function. This is the same as calling
1317 * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n).
1319 extern PNG_EXPORT(int,png_check_sig) PNGARG((png_bytep sig, int num));
1321 /* Allocate and initialize png_ptr struct for reading, and any other memory. */
1322 extern PNG_EXPORT(png_structp,png_create_read_struct)
1323 PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1324 png_error_ptr error_fn, png_error_ptr warn_fn));
1326 /* Allocate and initialize png_ptr struct for writing, and any other memory */
1327 extern PNG_EXPORT(png_structp,png_create_write_struct)
1328 PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1329 png_error_ptr error_fn, png_error_ptr warn_fn));
1331 extern PNG_EXPORT(png_uint_32,png_get_compression_buffer_size)
1332 PNGARG((png_structp png_ptr));
1334 extern PNG_EXPORT(void,png_set_compression_buffer_size)
1335 PNGARG((png_structp png_ptr, png_uint_32 size));
1337 /* Reset the compression stream */
1338 extern PNG_EXPORT(int,png_reset_zstream) PNGARG((png_structp png_ptr));
1340 /* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */
1341 #ifdef PNG_USER_MEM_SUPPORTED
1342 extern PNG_EXPORT(png_structp,png_create_read_struct_2)
1343 PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1344 png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
1345 png_malloc_ptr malloc_fn, png_free_ptr free_fn));
1346 extern PNG_EXPORT(png_structp,png_create_write_struct_2)
1347 PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1348 png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
1349 png_malloc_ptr malloc_fn, png_free_ptr free_fn));
1352 /* Write a PNG chunk - size, type, (optional) data, CRC. */
1353 extern PNG_EXPORT(void,png_write_chunk) PNGARG((png_structp png_ptr,
1354 png_bytep chunk_name, png_bytep data, png_size_t length));
1356 /* Write the start of a PNG chunk - length and chunk name. */
1357 extern PNG_EXPORT(void,png_write_chunk_start) PNGARG((png_structp png_ptr,
1358 png_bytep chunk_name, png_uint_32 length));
1360 /* Write the data of a PNG chunk started with png_write_chunk_start(). */
1361 extern PNG_EXPORT(void,png_write_chunk_data) PNGARG((png_structp png_ptr,
1362 png_bytep data, png_size_t length));
1364 /* Finish a chunk started with png_write_chunk_start() (includes CRC). */
1365 extern PNG_EXPORT(void,png_write_chunk_end) PNGARG((png_structp png_ptr));
1367 /* Allocate and initialize the info structure */
1368 extern PNG_EXPORT(png_infop,png_create_info_struct)
1369 PNGARG((png_structp png_ptr));
1371 /* Initialize the info structure (old interface - DEPRECATED) */
1372 extern PNG_EXPORT(void,png_info_init) PNGARG((png_infop info_ptr));
1373 #undef png_info_init
1374 #define png_info_init(info_ptr) png_info_init_3(&info_ptr, sizeof(png_info));
1375 extern PNG_EXPORT(void,png_info_init_3) PNGARG((png_infopp info_ptr,
1376 png_size_t png_info_struct_size));
1378 /* Writes all the PNG information before the image. */
1379 extern PNG_EXPORT(void,png_write_info_before_PLTE) PNGARG((png_structp png_ptr,
1380 png_infop info_ptr));
1381 extern PNG_EXPORT(void,png_write_info) PNGARG((png_structp png_ptr,
1382 png_infop info_ptr));
1384 /* read the information before the actual image data. */
1385 extern PNG_EXPORT(void,png_read_info) PNGARG((png_structp png_ptr,
1386 png_infop info_ptr));
1388 #if defined(PNG_TIME_RFC1123_SUPPORTED)
1389 extern PNG_EXPORT(png_charp,png_convert_to_rfc1123)
1390 PNGARG((png_structp png_ptr, png_timep ptime));
1393 #if !defined(_WIN32_WCE)
1394 /* "time.h" functions are not supported on WindowsCE */
1395 #if defined(PNG_WRITE_tIME_SUPPORTED)
1396 /* convert from a struct tm to png_time */
1397 extern PNG_EXPORT(void,png_convert_from_struct_tm) PNGARG((png_timep ptime,
1398 struct tm FAR * ttime));
1400 /* convert from time_t to png_time. Uses gmtime() */
1401 extern PNG_EXPORT(void,png_convert_from_time_t) PNGARG((png_timep ptime,
1403 #endif /* PNG_WRITE_tIME_SUPPORTED */
1404 #endif /* _WIN32_WCE */
1406 #if defined(PNG_READ_EXPAND_SUPPORTED)
1407 /* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
1408 extern PNG_EXPORT(void,png_set_expand) PNGARG((png_structp png_ptr));
1409 extern PNG_EXPORT(void,png_set_gray_1_2_4_to_8) PNGARG((png_structp png_ptr));
1410 extern PNG_EXPORT(void,png_set_palette_to_rgb) PNGARG((png_structp png_ptr));
1411 extern PNG_EXPORT(void,png_set_tRNS_to_alpha) PNGARG((png_structp png_ptr));
1414 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
1415 /* Use blue, green, red order for pixels. */
1416 extern PNG_EXPORT(void,png_set_bgr) PNGARG((png_structp png_ptr));
1419 #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
1420 /* Expand the grayscale to 24-bit RGB if necessary. */
1421 extern PNG_EXPORT(void,png_set_gray_to_rgb) PNGARG((png_structp png_ptr));
1424 #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
1425 /* Reduce RGB to grayscale. */
1426 #ifdef PNG_FLOATING_POINT_SUPPORTED
1427 extern PNG_EXPORT(void,png_set_rgb_to_gray) PNGARG((png_structp png_ptr,
1428 int error_action, double red, double green ));
1430 extern PNG_EXPORT(void,png_set_rgb_to_gray_fixed) PNGARG((png_structp png_ptr,
1431 int error_action, png_fixed_point red, png_fixed_point green ));
1432 extern PNG_EXPORT(png_byte,png_get_rgb_to_gray_status) PNGARG((png_structp
1436 extern PNG_EXPORT(void,png_build_grayscale_palette) PNGARG((int bit_depth,
1437 png_colorp palette));
1439 #if defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
1440 extern PNG_EXPORT(void,png_set_strip_alpha) PNGARG((png_structp png_ptr));
1443 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
1444 defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
1445 extern PNG_EXPORT(void,png_set_swap_alpha) PNGARG((png_structp png_ptr));
1448 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
1449 defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
1450 extern PNG_EXPORT(void,png_set_invert_alpha) PNGARG((png_structp png_ptr));
1453 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
1454 /* Add a filler byte to 24-bit RGB images. */
1455 extern PNG_EXPORT(void,png_set_filler) PNGARG((png_structp png_ptr,
1456 png_uint_32 filler, int flags));
1457 /* The values of the PNG_FILLER_ defines should NOT be changed */
1458 #define PNG_FILLER_BEFORE 0
1459 #define PNG_FILLER_AFTER 1
1460 #endif /* PNG_READ_FILLER_SUPPORTED || PNG_WRITE_FILLER_SUPPORTED */
1462 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
1463 /* Swap bytes in 16-bit depth files. */
1464 extern PNG_EXPORT(void,png_set_swap) PNGARG((png_structp png_ptr));
1467 #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
1468 /* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
1469 extern PNG_EXPORT(void,png_set_packing) PNGARG((png_structp png_ptr));
1472 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1473 /* Swap packing order of pixels in bytes. */
1474 extern PNG_EXPORT(void,png_set_packswap) PNGARG((png_structp png_ptr));
1477 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
1478 /* Converts files to legal bit depths. */
1479 extern PNG_EXPORT(void,png_set_shift) PNGARG((png_structp png_ptr,
1480 png_color_8p true_bits));
1483 #if defined(PNG_READ_INTERLACING_SUPPORTED) || \
1484 defined(PNG_WRITE_INTERLACING_SUPPORTED)
1485 /* Have the code handle the interlacing. Returns the number of passes. */
1486 extern PNG_EXPORT(int,png_set_interlace_handling) PNGARG((png_structp png_ptr));
1489 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
1490 /* Invert monochrome files */
1491 extern PNG_EXPORT(void,png_set_invert_mono) PNGARG((png_structp png_ptr));
1494 #if defined(PNG_READ_BACKGROUND_SUPPORTED)
1495 /* Handle alpha and tRNS by replacing with a background color. */
1496 #ifdef PNG_FLOATING_POINT_SUPPORTED
1497 extern PNG_EXPORT(void,png_set_background) PNGARG((png_structp png_ptr,
1498 png_color_16p background_color, int background_gamma_code,
1499 int need_expand, double background_gamma));
1501 #define PNG_BACKGROUND_GAMMA_UNKNOWN 0
1502 #define PNG_BACKGROUND_GAMMA_SCREEN 1
1503 #define PNG_BACKGROUND_GAMMA_FILE 2
1504 #define PNG_BACKGROUND_GAMMA_UNIQUE 3
1507 #if defined(PNG_READ_16_TO_8_SUPPORTED)
1508 /* strip the second byte of information from a 16-bit depth file. */
1509 extern PNG_EXPORT(void,png_set_strip_16) PNGARG((png_structp png_ptr));
1512 #if defined(PNG_READ_DITHER_SUPPORTED)
1513 /* Turn on dithering, and reduce the palette to the number of colors available. */
1514 extern PNG_EXPORT(void,png_set_dither) PNGARG((png_structp png_ptr,
1515 png_colorp palette, int num_palette, int maximum_colors,
1516 png_uint_16p histogram, int full_dither));
1519 #if defined(PNG_READ_GAMMA_SUPPORTED)
1520 /* Handle gamma correction. Screen_gamma=(display_exponent) */
1521 #ifdef PNG_FLOATING_POINT_SUPPORTED
1522 extern PNG_EXPORT(void,png_set_gamma) PNGARG((png_structp png_ptr,
1523 double screen_gamma, double default_file_gamma));
1527 #if defined(PNG_READ_EMPTY_PLTE_SUPPORTED) || \
1528 defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
1529 /* Permit or disallow empty PLTE (0: not permitted, 1: permitted) */
1530 /* Deprecated and will be removed. Use png_permit_mng_features() instead. */
1531 extern PNG_EXPORT(void,png_permit_empty_plte) PNGARG((png_structp png_ptr,
1532 int empty_plte_permitted));
1535 #if defined(PNG_WRITE_FLUSH_SUPPORTED)
1536 /* Set how many lines between output flushes - 0 for no flushing */
1537 extern PNG_EXPORT(void,png_set_flush) PNGARG((png_structp png_ptr, int nrows));
1538 /* Flush the current PNG output buffer */
1539 extern PNG_EXPORT(void,png_write_flush) PNGARG((png_structp png_ptr));
1542 /* optional update palette with requested transformations */
1543 extern PNG_EXPORT(void,png_start_read_image) PNGARG((png_structp png_ptr));
1545 /* optional call to update the users info structure */
1546 extern PNG_EXPORT(void,png_read_update_info) PNGARG((png_structp png_ptr,
1547 png_infop info_ptr));
1549 /* read one or more rows of image data. */
1550 extern PNG_EXPORT(void,png_read_rows) PNGARG((png_structp png_ptr,
1551 png_bytepp row, png_bytepp display_row, png_uint_32 num_rows));
1553 /* read a row of data. */
1554 extern PNG_EXPORT(void,png_read_row) PNGARG((png_structp png_ptr,
1556 png_bytep display_row));
1558 /* read the whole image into memory at once. */
1559 extern PNG_EXPORT(void,png_read_image) PNGARG((png_structp png_ptr,
1562 /* write a row of image data */
1563 extern PNG_EXPORT(void,png_write_row) PNGARG((png_structp png_ptr,
1566 /* write a few rows of image data */
1567 extern PNG_EXPORT(void,png_write_rows) PNGARG((png_structp png_ptr,
1568 png_bytepp row, png_uint_32 num_rows));
1570 /* write the image data */
1571 extern PNG_EXPORT(void,png_write_image) PNGARG((png_structp png_ptr,
1574 /* writes the end of the PNG file. */
1575 extern PNG_EXPORT(void,png_write_end) PNGARG((png_structp png_ptr,
1576 png_infop info_ptr));
1578 /* read the end of the PNG file. */
1579 extern PNG_EXPORT(void,png_read_end) PNGARG((png_structp png_ptr,
1580 png_infop info_ptr));
1582 /* free any memory associated with the png_info_struct */
1583 extern PNG_EXPORT(void,png_destroy_info_struct) PNGARG((png_structp png_ptr,
1584 png_infopp info_ptr_ptr));
1586 /* free any memory associated with the png_struct and the png_info_structs */
1587 extern PNG_EXPORT(void,png_destroy_read_struct) PNGARG((png_structpp
1588 png_ptr_ptr, png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr));
1590 /* free all memory used by the read (old method - NOT DLL EXPORTED) */
1591 extern void png_read_destroy PNGARG((png_structp png_ptr, png_infop info_ptr,
1592 png_infop end_info_ptr));
1594 /* free any memory associated with the png_struct and the png_info_structs */
1595 extern PNG_EXPORT(void,png_destroy_write_struct)
1596 PNGARG((png_structpp png_ptr_ptr, png_infopp info_ptr_ptr));
1598 /* free any memory used in png_ptr struct (old method - NOT DLL EXPORTED) */
1599 extern void png_write_destroy PNGARG((png_structp png_ptr));
1601 /* set the libpng method of handling chunk CRC errors */
1602 extern PNG_EXPORT(void,png_set_crc_action) PNGARG((png_structp png_ptr,
1603 int crit_action, int ancil_action));
1605 /* Values for png_set_crc_action() to say how to handle CRC errors in
1606 * ancillary and critical chunks, and whether to use the data contained
1607 * therein. Note that it is impossible to "discard" data in a critical
1608 * chunk. For versions prior to 0.90, the action was always error/quit,
1609 * whereas in version 0.90 and later, the action for CRC errors in ancillary
1610 * chunks is warn/discard. These values should NOT be changed.
1612 * value action:critical action:ancillary
1614 #define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */
1615 #define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */
1616 #define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */
1617 #define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */
1618 #define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */
1619 #define PNG_CRC_NO_CHANGE 5 /* use current value use current value */
1621 /* These functions give the user control over the scan-line filtering in
1622 * libpng and the compression methods used by zlib. These functions are
1623 * mainly useful for testing, as the defaults should work with most users.
1624 * Those users who are tight on memory or want faster performance at the
1625 * expense of compression can modify them. See the compression library
1626 * header file (zlib.h) for an explination of the compression functions.
1629 /* set the filtering method(s) used by libpng. Currently, the only valid
1630 * value for "method" is 0.
1632 extern PNG_EXPORT(void,png_set_filter) PNGARG((png_structp png_ptr, int method,
1635 /* Flags for png_set_filter() to say which filters to use. The flags
1636 * are chosen so that they don't conflict with real filter types
1637 * below, in case they are supplied instead of the #defined constants.
1638 * These values should NOT be changed.
1640 #define PNG_NO_FILTERS 0x00
1641 #define PNG_FILTER_NONE 0x08
1642 #define PNG_FILTER_SUB 0x10
1643 #define PNG_FILTER_UP 0x20
1644 #define PNG_FILTER_AVG 0x40
1645 #define PNG_FILTER_PAETH 0x80
1646 #define PNG_ALL_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP | \
1647 PNG_FILTER_AVG | PNG_FILTER_PAETH)
1649 /* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
1650 * These defines should NOT be changed.
1652 #define PNG_FILTER_VALUE_NONE 0
1653 #define PNG_FILTER_VALUE_SUB 1
1654 #define PNG_FILTER_VALUE_UP 2
1655 #define PNG_FILTER_VALUE_AVG 3
1656 #define PNG_FILTER_VALUE_PAETH 4
1657 #define PNG_FILTER_VALUE_LAST 5
1659 #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) /* EXPERIMENTAL */
1660 /* The "heuristic_method" is given by one of the PNG_FILTER_HEURISTIC_
1661 * defines, either the default (minimum-sum-of-absolute-differences), or
1662 * the experimental method (weighted-minimum-sum-of-absolute-differences).
1664 * Weights are factors >= 1.0, indicating how important it is to keep the
1665 * filter type consistent between rows. Larger numbers mean the current
1666 * filter is that many times as likely to be the same as the "num_weights"
1667 * previous filters. This is cumulative for each previous row with a weight.
1668 * There needs to be "num_weights" values in "filter_weights", or it can be
1669 * NULL if the weights aren't being specified. Weights have no influence on
1670 * the selection of the first row filter. Well chosen weights can (in theory)
1671 * improve the compression for a given image.
1673 * Costs are factors >= 1.0 indicating the relative decoding costs of a
1674 * filter type. Higher costs indicate more decoding expense, and are
1675 * therefore less likely to be selected over a filter with lower computational
1676 * costs. There needs to be a value in "filter_costs" for each valid filter
1677 * type (given by PNG_FILTER_VALUE_LAST), or it can be NULL if you aren't
1678 * setting the costs. Costs try to improve the speed of decompression without
1679 * unduly increasing the compressed image size.
1681 * A negative weight or cost indicates the default value is to be used, and
1682 * values in the range [0.0, 1.0) indicate the value is to remain unchanged.
1683 * The default values for both weights and costs are currently 1.0, but may
1684 * change if good general weighting/cost heuristics can be found. If both
1685 * the weights and costs are set to 1.0, this degenerates the WEIGHTED method
1686 * to the UNWEIGHTED method, but with added encoding time/computation.
1688 #ifdef PNG_FLOATING_POINT_SUPPORTED
1689 extern PNG_EXPORT(void,png_set_filter_heuristics) PNGARG((png_structp png_ptr,
1690 int heuristic_method, int num_weights, png_doublep filter_weights,
1691 png_doublep filter_costs));
1693 #endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
1695 /* Heuristic used for row filter selection. These defines should NOT be
1698 #define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */
1699 #define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */
1700 #define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */
1701 #define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */
1703 /* Set the library compression level. Currently, valid values range from
1704 * 0 - 9, corresponding directly to the zlib compression levels 0 - 9
1705 * (0 - no compression, 9 - "maximal" compression). Note that tests have
1706 * shown that zlib compression levels 3-6 usually perform as well as level 9
1707 * for PNG images, and do considerably fewer caclulations. In the future,
1708 * these values may not correspond directly to the zlib compression levels.
1710 extern PNG_EXPORT(void,png_set_compression_level) PNGARG((png_structp png_ptr,
1713 extern PNG_EXPORT(void,png_set_compression_mem_level)
1714 PNGARG((png_structp png_ptr, int mem_level));
1716 extern PNG_EXPORT(void,png_set_compression_strategy)
1717 PNGARG((png_structp png_ptr, int strategy));
1719 extern PNG_EXPORT(void,png_set_compression_window_bits)
1720 PNGARG((png_structp png_ptr, int window_bits));
1722 extern PNG_EXPORT(void,png_set_compression_method) PNGARG((png_structp png_ptr,
1725 /* These next functions are called for input/output, memory, and error
1726 * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c,
1727 * and call standard C I/O routines such as fread(), fwrite(), and
1728 * fprintf(). These functions can be made to use other I/O routines
1729 * at run time for those applications that need to handle I/O in a
1730 * different manner by calling png_set_???_fn(). See libpng.txt for
1734 #if !defined(PNG_NO_STDIO)
1735 /* Initialize the input/output for the PNG file to the default functions. */
1736 extern PNG_EXPORT(void,png_init_io) PNGARG((png_structp png_ptr, png_FILE_p fp));
1739 /* Replace the (error and abort), and warning functions with user
1740 * supplied functions. If no messages are to be printed you must still
1741 * write and use replacement functions. The replacement error_fn should
1742 * still do a longjmp to the last setjmp location if you are using this
1743 * method of error handling. If error_fn or warning_fn is NULL, the
1744 * default function will be used.
1747 extern PNG_EXPORT(void,png_set_error_fn) PNGARG((png_structp png_ptr,
1748 png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn));
1750 /* Return the user pointer associated with the error functions */
1751 extern PNG_EXPORT(png_voidp,png_get_error_ptr) PNGARG((png_structp png_ptr));
1753 /* Replace the default data output functions with a user supplied one(s).
1754 * If buffered output is not used, then output_flush_fn can be set to NULL.
1755 * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time
1756 * output_flush_fn will be ignored (and thus can be NULL).
1758 extern PNG_EXPORT(void,png_set_write_fn) PNGARG((png_structp png_ptr,
1759 png_voidp io_ptr, png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn));
1761 /* Replace the default data input function with a user supplied one. */
1762 extern PNG_EXPORT(void,png_set_read_fn) PNGARG((png_structp png_ptr,
1763 png_voidp io_ptr, png_rw_ptr read_data_fn));
1765 /* Return the user pointer associated with the I/O functions */
1766 extern PNG_EXPORT(png_voidp,png_get_io_ptr) PNGARG((png_structp png_ptr));
1768 extern PNG_EXPORT(void,png_set_read_status_fn) PNGARG((png_structp png_ptr,
1769 png_read_status_ptr read_row_fn));
1771 extern PNG_EXPORT(void,png_set_write_status_fn) PNGARG((png_structp png_ptr,
1772 png_write_status_ptr write_row_fn));
1774 #ifdef PNG_USER_MEM_SUPPORTED
1775 /* Replace the default memory allocation functions with user supplied one(s). */
1776 extern PNG_EXPORT(void,png_set_mem_fn) PNGARG((png_structp png_ptr,
1777 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn));
1778 /* Return the user pointer associated with the memory functions */
1779 extern PNG_EXPORT(png_voidp,png_get_mem_ptr) PNGARG((png_structp png_ptr));
1782 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
1783 defined(PNG_LEGACY_SUPPORTED)
1784 extern PNG_EXPORT(void,png_set_read_user_transform_fn) PNGARG((png_structp
1785 png_ptr, png_user_transform_ptr read_user_transform_fn));
1788 #if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
1789 defined(PNG_LEGACY_SUPPORTED)
1790 extern PNG_EXPORT(void,png_set_write_user_transform_fn) PNGARG((png_structp
1791 png_ptr, png_user_transform_ptr write_user_transform_fn));
1794 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
1795 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
1796 defined(PNG_LEGACY_SUPPORTED)
1797 extern PNG_EXPORT(void,png_set_user_transform_info) PNGARG((png_structp
1798 png_ptr, png_voidp user_transform_ptr, int user_transform_depth,
1799 int user_transform_channels));
1800 /* Return the user pointer associated with the user transform functions */
1801 extern PNG_EXPORT(png_voidp,png_get_user_transform_ptr)
1802 PNGARG((png_structp png_ptr));
1805 #ifdef PNG_USER_CHUNKS_SUPPORTED
1806 extern PNG_EXPORT(void,png_set_read_user_chunk_fn) PNGARG((png_structp png_ptr,
1807 png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));
1808 extern PNG_EXPORT(png_voidp,png_get_user_chunk_ptr) PNGARG((png_structp
1812 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1813 /* Sets the function callbacks for the push reader, and a pointer to a
1814 * user-defined structure available to the callback functions.
1816 extern PNG_EXPORT(void,png_set_progressive_read_fn) PNGARG((png_structp png_ptr,
1817 png_voidp progressive_ptr,
1818 png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
1819 png_progressive_end_ptr end_fn));
1821 /* returns the user pointer associated with the push read functions */
1822 extern PNG_EXPORT(png_voidp,png_get_progressive_ptr)
1823 PNGARG((png_structp png_ptr));
1825 /* function to be called when data becomes available */
1826 extern PNG_EXPORT(void,png_process_data) PNGARG((png_structp png_ptr,
1827 png_infop info_ptr, png_bytep buffer, png_size_t buffer_size));
1829 /* function that combines rows. Not very much different than the
1830 * png_combine_row() call. Is this even used?????
1832 extern PNG_EXPORT(void,png_progressive_combine_row) PNGARG((png_structp png_ptr,
1833 png_bytep old_row, png_bytep new_row));
1834 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
1836 extern PNG_EXPORT(png_voidp,png_malloc) PNGARG((png_structp png_ptr,
1839 #if defined(PNG_1_0_X)
1840 # define png_malloc_warn png_malloc
1842 /* Added at libpng version 1.2.4 */
1843 extern PNG_EXPORT(png_voidp,png_malloc_warn) PNGARG((png_structp png_ptr,
1847 /* frees a pointer allocated by png_malloc() */
1848 extern PNG_EXPORT(void,png_free) PNGARG((png_structp png_ptr, png_voidp ptr));
1850 #if defined(PNG_1_0_X)
1851 /* Function to allocate memory for zlib. */
1852 extern PNG_EXPORT(voidpf,png_zalloc) PNGARG((voidpf png_ptr, uInt items,
1855 /* Function to free memory for zlib */
1856 extern PNG_EXPORT(void,png_zfree) PNGARG((voidpf png_ptr, voidpf ptr));
1859 /* Free data that was allocated internally */
1860 extern PNG_EXPORT(void,png_free_data) PNGARG((png_structp png_ptr,
1861 png_infop info_ptr, png_uint_32 free_me, int num));
1862 #ifdef PNG_FREE_ME_SUPPORTED
1863 /* Reassign responsibility for freeing existing data, whether allocated
1864 * by libpng or by the application */
1865 extern PNG_EXPORT(void,png_data_freer) PNGARG((png_structp png_ptr,
1866 png_infop info_ptr, int freer, png_uint_32 mask));
1868 /* assignments for png_data_freer */
1869 #define PNG_DESTROY_WILL_FREE_DATA 1
1870 #define PNG_SET_WILL_FREE_DATA 1
1871 #define PNG_USER_WILL_FREE_DATA 2
1872 /* Flags for png_ptr->free_me and info_ptr->free_me */
1873 #define PNG_FREE_HIST 0x0008
1874 #define PNG_FREE_ICCP 0x0010
1875 #define PNG_FREE_SPLT 0x0020
1876 #define PNG_FREE_ROWS 0x0040
1877 #define PNG_FREE_PCAL 0x0080
1878 #define PNG_FREE_SCAL 0x0100
1879 #define PNG_FREE_UNKN 0x0200
1880 #define PNG_FREE_LIST 0x0400
1881 #define PNG_FREE_PLTE 0x1000
1882 #define PNG_FREE_TRNS 0x2000
1883 #define PNG_FREE_TEXT 0x4000
1884 #define PNG_FREE_ALL 0x7fff
1885 #define PNG_FREE_MUL 0x4220 /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */
1887 #ifdef PNG_USER_MEM_SUPPORTED
1888 extern PNG_EXPORT(png_voidp,png_malloc_default) PNGARG((png_structp png_ptr,
1890 extern PNG_EXPORT(void,png_free_default) PNGARG((png_structp png_ptr,
1894 extern PNG_EXPORT(png_voidp,png_memcpy_check) PNGARG((png_structp png_ptr,
1895 png_voidp s1, png_voidp s2, png_uint_32 size));
1897 extern PNG_EXPORT(png_voidp,png_memset_check) PNGARG((png_structp png_ptr,
1898 png_voidp s1, int value, png_uint_32 size));
1900 #if defined(USE_FAR_KEYWORD) /* memory model conversion function */
1901 extern void *png_far_to_near PNGARG((png_structp png_ptr,png_voidp ptr,
1903 #endif /* USE_FAR_KEYWORD */
1905 /* Fatal error in PNG image of libpng - can't continue */
1906 extern PNG_EXPORT(void,png_error) PNGARG((png_structp png_ptr,
1907 png_const_charp error_message));
1909 /* The same, but the chunk name is prepended to the error string. */
1910 extern PNG_EXPORT(void,png_chunk_error) PNGARG((png_structp png_ptr,
1911 png_const_charp error_message));
1913 /* Non-fatal error in libpng. Can continue, but may have a problem. */
1914 extern PNG_EXPORT(void,png_warning) PNGARG((png_structp png_ptr,
1915 png_const_charp warning_message));
1917 /* Non-fatal error in libpng, chunk name is prepended to message. */
1918 extern PNG_EXPORT(void,png_chunk_warning) PNGARG((png_structp png_ptr,
1919 png_const_charp warning_message));
1921 /* The png_set_<chunk> functions are for storing values in the png_info_struct.
1922 * Similarly, the png_get_<chunk> calls are used to read values from the
1923 * png_info_struct, either storing the parameters in the passed variables, or
1924 * setting pointers into the png_info_struct where the data is stored. The
1925 * png_get_<chunk> functions return a non-zero value if the data was available
1926 * in info_ptr, or return zero and do not change any of the parameters if the
1927 * data was not available.
1929 * These functions should be used instead of directly accessing png_info
1930 * to avoid problems with future changes in the size and internal layout of
1933 /* Returns "flag" if chunk data is valid in info_ptr. */
1934 extern PNG_EXPORT(png_uint_32,png_get_valid) PNGARG((png_structp png_ptr,
1935 png_infop info_ptr, png_uint_32 flag));
1937 /* Returns number of bytes needed to hold a transformed row. */
1938 extern PNG_EXPORT(png_uint_32,png_get_rowbytes) PNGARG((png_structp png_ptr,
1939 png_infop info_ptr));
1941 #if defined(PNG_INFO_IMAGE_SUPPORTED)
1942 /* Returns row_pointers, which is an array of pointers to scanlines that was
1943 returned from png_read_png(). */
1944 extern PNG_EXPORT(png_bytepp,png_get_rows) PNGARG((png_structp png_ptr,
1945 png_infop info_ptr));
1946 /* Set row_pointers, which is an array of pointers to scanlines for use
1947 by png_write_png(). */
1948 extern PNG_EXPORT(void,png_set_rows) PNGARG((png_structp png_ptr,
1949 png_infop info_ptr, png_bytepp row_pointers));
1952 /* Returns number of color channels in image. */
1953 extern PNG_EXPORT(png_byte,png_get_channels) PNGARG((png_structp png_ptr,
1954 png_infop info_ptr));
1956 #ifdef PNG_EASY_ACCESS_SUPPORTED
1957 /* Returns image width in pixels. */
1958 extern PNG_EXPORT(png_uint_32, png_get_image_width) PNGARG((png_structp
1959 png_ptr, png_infop info_ptr));
1961 /* Returns image height in pixels. */
1962 extern PNG_EXPORT(png_uint_32, png_get_image_height) PNGARG((png_structp
1963 png_ptr, png_infop info_ptr));
1965 /* Returns image bit_depth. */
1966 extern PNG_EXPORT(png_byte, png_get_bit_depth) PNGARG((png_structp
1967 png_ptr, png_infop info_ptr));
1969 /* Returns image color_type. */
1970 extern PNG_EXPORT(png_byte, png_get_color_type) PNGARG((png_structp
1971 png_ptr, png_infop info_ptr));
1973 /* Returns image filter_type. */
1974 extern PNG_EXPORT(png_byte, png_get_filter_type) PNGARG((png_structp
1975 png_ptr, png_infop info_ptr));
1977 /* Returns image interlace_type. */
1978 extern PNG_EXPORT(png_byte, png_get_interlace_type) PNGARG((png_structp
1979 png_ptr, png_infop info_ptr));
1981 /* Returns image compression_type. */
1982 extern PNG_EXPORT(png_byte, png_get_compression_type) PNGARG((png_structp
1983 png_ptr, png_infop info_ptr));
1985 /* Returns image resolution in pixels per meter, from pHYs chunk data. */
1986 extern PNG_EXPORT(png_uint_32, png_get_pixels_per_meter) PNGARG((png_structp
1987 png_ptr, png_infop info_ptr));
1988 extern PNG_EXPORT(png_uint_32, png_get_x_pixels_per_meter) PNGARG((png_structp
1989 png_ptr, png_infop info_ptr));
1990 extern PNG_EXPORT(png_uint_32, png_get_y_pixels_per_meter) PNGARG((png_structp
1991 png_ptr, png_infop info_ptr));
1993 /* Returns pixel aspect ratio, computed from pHYs chunk data. */
1994 #ifdef PNG_FLOATING_POINT_SUPPORTED
1995 extern PNG_EXPORT(float, png_get_pixel_aspect_ratio) PNGARG((png_structp
1996 png_ptr, png_infop info_ptr));
1999 /* Returns image x, y offset in pixels or microns, from oFFs chunk data. */
2000 extern PNG_EXPORT(png_int_32, png_get_x_offset_pixels) PNGARG((png_structp
2001 png_ptr, png_infop info_ptr));
2002 extern PNG_EXPORT(png_int_32, png_get_y_offset_pixels) PNGARG((png_structp
2003 png_ptr, png_infop info_ptr));
2004 extern PNG_EXPORT(png_int_32, png_get_x_offset_microns) PNGARG((png_structp
2005 png_ptr, png_infop info_ptr));
2006 extern PNG_EXPORT(png_int_32, png_get_y_offset_microns) PNGARG((png_structp
2007 png_ptr, png_infop info_ptr));
2009 #endif /* PNG_EASY_ACCESS_SUPPORTED */
2011 /* Returns pointer to signature string read from PNG header */
2012 extern PNG_EXPORT(png_bytep,png_get_signature) PNGARG((png_structp png_ptr,
2013 png_infop info_ptr));
2015 #if defined(PNG_bKGD_SUPPORTED)
2016 extern PNG_EXPORT(png_uint_32,png_get_bKGD) PNGARG((png_structp png_ptr,
2017 png_infop info_ptr, png_color_16p *background));
2020 #if defined(PNG_bKGD_SUPPORTED)
2021 extern PNG_EXPORT(void,png_set_bKGD) PNGARG((png_structp png_ptr,
2022 png_infop info_ptr, png_color_16p background));
2025 #if defined(PNG_cHRM_SUPPORTED)
2026 #ifdef PNG_FLOATING_POINT_SUPPORTED
2027 extern PNG_EXPORT(png_uint_32,png_get_cHRM) PNGARG((png_structp png_ptr,
2028 png_infop info_ptr, double *white_x, double *white_y, double *red_x,
2029 double *red_y, double *green_x, double *green_y, double *blue_x,
2032 #ifdef PNG_FIXED_POINT_SUPPORTED
2033 extern PNG_EXPORT(png_uint_32,png_get_cHRM_fixed) PNGARG((png_structp png_ptr,
2034 png_infop info_ptr, png_fixed_point *int_white_x, png_fixed_point
2035 *int_white_y, png_fixed_point *int_red_x, png_fixed_point *int_red_y,
2036 png_fixed_point *int_green_x, png_fixed_point *int_green_y, png_fixed_point
2037 *int_blue_x, png_fixed_point *int_blue_y));
2041 #if defined(PNG_cHRM_SUPPORTED)
2042 #ifdef PNG_FLOATING_POINT_SUPPORTED
2043 extern PNG_EXPORT(void,png_set_cHRM) PNGARG((png_structp png_ptr,
2044 png_infop info_ptr, double white_x, double white_y, double red_x,
2045 double red_y, double green_x, double green_y, double blue_x, double blue_y));
2047 #ifdef PNG_FIXED_POINT_SUPPORTED
2048 extern PNG_EXPORT(void,png_set_cHRM_fixed) PNGARG((png_structp png_ptr,
2049 png_infop info_ptr, png_fixed_point int_white_x, png_fixed_point int_white_y,
2050 png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
2051 int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
2052 png_fixed_point int_blue_y));
2056 #if defined(PNG_gAMA_SUPPORTED)
2057 #ifdef PNG_FLOATING_POINT_SUPPORTED
2058 extern PNG_EXPORT(png_uint_32,png_get_gAMA) PNGARG((png_structp png_ptr,
2059 png_infop info_ptr, double *file_gamma));
2061 extern PNG_EXPORT(png_uint_32,png_get_gAMA_fixed) PNGARG((png_structp png_ptr,
2062 png_infop info_ptr, png_fixed_point *int_file_gamma));
2065 #if defined(PNG_gAMA_SUPPORTED)
2066 #ifdef PNG_FLOATING_POINT_SUPPORTED
2067 extern PNG_EXPORT(void,png_set_gAMA) PNGARG((png_structp png_ptr,
2068 png_infop info_ptr, double file_gamma));
2070 extern PNG_EXPORT(void,png_set_gAMA_fixed) PNGARG((png_structp png_ptr,
2071 png_infop info_ptr, png_fixed_point int_file_gamma));
2074 #if defined(PNG_hIST_SUPPORTED)
2075 extern PNG_EXPORT(png_uint_32,png_get_hIST) PNGARG((png_structp png_ptr,
2076 png_infop info_ptr, png_uint_16p *hist));
2079 #if defined(PNG_hIST_SUPPORTED)
2080 extern PNG_EXPORT(void,png_set_hIST) PNGARG((png_structp png_ptr,
2081 png_infop info_ptr, png_uint_16p hist));
2084 extern PNG_EXPORT(png_uint_32,png_get_IHDR) PNGARG((png_structp png_ptr,
2085 png_infop info_ptr, png_uint_32 *width, png_uint_32 *height,
2086 int *bit_depth, int *color_type, int *interlace_method,
2087 int *compression_method, int *filter_method));
2089 extern PNG_EXPORT(void,png_set_IHDR) PNGARG((png_structp png_ptr,
2090 png_infop info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth,
2091 int color_type, int interlace_method, int compression_method,
2092 int filter_method));
2094 #if defined(PNG_oFFs_SUPPORTED)
2095 extern PNG_EXPORT(png_uint_32,png_get_oFFs) PNGARG((png_structp png_ptr,
2096 png_infop info_ptr, png_int_32 *offset_x, png_int_32 *offset_y,
2100 #if defined(PNG_oFFs_SUPPORTED)
2101 extern PNG_EXPORT(void,png_set_oFFs) PNGARG((png_structp png_ptr,
2102 png_infop info_ptr, png_int_32 offset_x, png_int_32 offset_y,
2106 #if defined(PNG_pCAL_SUPPORTED)
2107 extern PNG_EXPORT(png_uint_32,png_get_pCAL) PNGARG((png_structp png_ptr,
2108 png_infop info_ptr, png_charp *purpose, png_int_32 *X0, png_int_32 *X1,
2109 int *type, int *nparams, png_charp *units, png_charpp *params));
2112 #if defined(PNG_pCAL_SUPPORTED)
2113 extern PNG_EXPORT(void,png_set_pCAL) PNGARG((png_structp png_ptr,
2114 png_infop info_ptr, png_charp purpose, png_int_32 X0, png_int_32 X1,
2115 int type, int nparams, png_charp units, png_charpp params));
2118 #if defined(PNG_pHYs_SUPPORTED)
2119 extern PNG_EXPORT(png_uint_32,png_get_pHYs) PNGARG((png_structp png_ptr,
2120 png_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type));
2123 #if defined(PNG_pHYs_SUPPORTED)
2124 extern PNG_EXPORT(void,png_set_pHYs) PNGARG((png_structp png_ptr,
2125 png_infop info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type));
2128 extern PNG_EXPORT(png_uint_32,png_get_PLTE) PNGARG((png_structp png_ptr,
2129 png_infop info_ptr, png_colorp *palette, int *num_palette));
2131 extern PNG_EXPORT(void,png_set_PLTE) PNGARG((png_structp png_ptr,
2132 png_infop info_ptr, png_colorp palette, int num_palette));
2134 #if defined(PNG_sBIT_SUPPORTED)
2135 extern PNG_EXPORT(png_uint_32,png_get_sBIT) PNGARG((png_structp png_ptr,
2136 png_infop info_ptr, png_color_8p *sig_bit));
2139 #if defined(PNG_sBIT_SUPPORTED)
2140 extern PNG_EXPORT(void,png_set_sBIT) PNGARG((png_structp png_ptr,
2141 png_infop info_ptr, png_color_8p sig_bit));
2144 #if defined(PNG_sRGB_SUPPORTED)
2145 extern PNG_EXPORT(png_uint_32,png_get_sRGB) PNGARG((png_structp png_ptr,
2146 png_infop info_ptr, int *intent));
2149 #if defined(PNG_sRGB_SUPPORTED)
2150 extern PNG_EXPORT(void,png_set_sRGB) PNGARG((png_structp png_ptr,
2151 png_infop info_ptr, int intent));
2152 extern PNG_EXPORT(void,png_set_sRGB_gAMA_and_cHRM) PNGARG((png_structp png_ptr,
2153 png_infop info_ptr, int intent));
2156 #if defined(PNG_iCCP_SUPPORTED)
2157 extern PNG_EXPORT(png_uint_32,png_get_iCCP) PNGARG((png_structp png_ptr,
2158 png_infop info_ptr, png_charpp name, int *compression_type,
2159 png_charpp profile, png_uint_32 *proflen));
2160 /* Note to maintainer: profile should be png_bytepp */
2163 #if defined(PNG_iCCP_SUPPORTED)
2164 extern PNG_EXPORT(void,png_set_iCCP) PNGARG((png_structp png_ptr,
2165 png_infop info_ptr, png_charp name, int compression_type,
2166 png_charp profile, png_uint_32 proflen));
2167 /* Note to maintainer: profile should be png_bytep */
2170 #if defined(PNG_sPLT_SUPPORTED)
2171 extern PNG_EXPORT(png_uint_32,png_get_sPLT) PNGARG((png_structp png_ptr,
2172 png_infop info_ptr, png_sPLT_tpp entries));
2175 #if defined(PNG_sPLT_SUPPORTED)
2176 extern PNG_EXPORT(void,png_set_sPLT) PNGARG((png_structp png_ptr,
2177 png_infop info_ptr, png_sPLT_tp entries, int nentries));
2180 #if defined(PNG_TEXT_SUPPORTED)
2181 /* png_get_text also returns the number of text chunks in *num_text */
2182 extern PNG_EXPORT(png_uint_32,png_get_text) PNGARG((png_structp png_ptr,
2183 png_infop info_ptr, png_textp *text_ptr, int *num_text));
2187 * Note while png_set_text() will accept a structure whose text,
2188 * language, and translated keywords are NULL pointers, the structure
2189 * returned by png_get_text will always contain regular
2190 * zero-terminated C strings. They might be empty strings but
2191 * they will never be NULL pointers.
2194 #if defined(PNG_TEXT_SUPPORTED)
2195 extern PNG_EXPORT(void,png_set_text) PNGARG((png_structp png_ptr,
2196 png_infop info_ptr, png_textp text_ptr, int num_text));
2199 #if defined(PNG_tIME_SUPPORTED)
2200 extern PNG_EXPORT(png_uint_32,png_get_tIME) PNGARG((png_structp png_ptr,
2201 png_infop info_ptr, png_timep *mod_time));
2204 #if defined(PNG_tIME_SUPPORTED)
2205 extern PNG_EXPORT(void,png_set_tIME) PNGARG((png_structp png_ptr,
2206 png_infop info_ptr, png_timep mod_time));
2209 #if defined(PNG_tRNS_SUPPORTED)
2210 extern PNG_EXPORT(png_uint_32,png_get_tRNS) PNGARG((png_structp png_ptr,
2211 png_infop info_ptr, png_bytep *trans, int *num_trans,
2212 png_color_16p *trans_values));
2215 #if defined(PNG_tRNS_SUPPORTED)
2216 extern PNG_EXPORT(void,png_set_tRNS) PNGARG((png_structp png_ptr,
2217 png_infop info_ptr, png_bytep trans, int num_trans,
2218 png_color_16p trans_values));
2221 #if defined(PNG_tRNS_SUPPORTED)
2224 #if defined(PNG_sCAL_SUPPORTED)
2225 #ifdef PNG_FLOATING_POINT_SUPPORTED
2226 extern PNG_EXPORT(png_uint_32,png_get_sCAL) PNGARG((png_structp png_ptr,
2227 png_infop info_ptr, int *unit, double *width, double *height));
2229 #ifdef PNG_FIXED_POINT_SUPPORTED
2230 extern PNG_EXPORT(png_uint_32,png_get_sCAL_s) PNGARG((png_structp png_ptr,
2231 png_infop info_ptr, int *unit, png_charpp swidth, png_charpp sheight));
2234 #endif /* PNG_sCAL_SUPPORTED */
2236 #if defined(PNG_sCAL_SUPPORTED)
2237 #ifdef PNG_FLOATING_POINT_SUPPORTED
2238 extern PNG_EXPORT(void,png_set_sCAL) PNGARG((png_structp png_ptr,
2239 png_infop info_ptr, int unit, double width, double height));
2241 #ifdef PNG_FIXED_POINT_SUPPORTED
2242 extern PNG_EXPORT(void,png_set_sCAL_s) PNGARG((png_structp png_ptr,
2243 png_infop info_ptr, int unit, png_charp swidth, png_charp sheight));
2245 #endif /* PNG_sCAL_SUPPORTED || PNG_WRITE_sCAL_SUPPORTED */
2247 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
2248 /* provide a list of chunks and how they are to be handled, if the built-in
2249 handling or default unknown chunk handling is not desired. Any chunks not
2250 listed will be handled in the default manner. The IHDR and IEND chunks
2252 keep = 0: follow default behavour
2254 = 2: keep only if safe-to-copy
2255 = 3: keep even if unsafe-to-copy
2257 extern PNG_EXPORT(void, png_set_keep_unknown_chunks) PNGARG((png_structp
2258 png_ptr, int keep, png_bytep chunk_list, int num_chunks));
2259 extern PNG_EXPORT(void, png_set_unknown_chunks) PNGARG((png_structp png_ptr,
2260 png_infop info_ptr, png_unknown_chunkp unknowns, int num_unknowns));
2261 extern PNG_EXPORT(void, png_set_unknown_chunk_location)
2262 PNGARG((png_structp png_ptr, png_infop info_ptr, int chunk, int location));
2263 extern PNG_EXPORT(png_uint_32,png_get_unknown_chunks) PNGARG((png_structp
2264 png_ptr, png_infop info_ptr, png_unknown_chunkpp entries));
2266 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
2267 PNG_EXPORT(int,png_handle_as_unknown) PNGARG((png_structp png_ptr, png_bytep
2271 /* Png_free_data() will turn off the "valid" flag for anything it frees.
2272 If you need to turn it off for a chunk that your application has freed,
2273 you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK); */
2274 extern PNG_EXPORT(void, png_set_invalid) PNGARG((png_structp png_ptr,
2275 png_infop info_ptr, int mask));
2277 #if defined(PNG_INFO_IMAGE_SUPPORTED)
2278 /* The "params" pointer is currently not used and is for future expansion. */
2279 extern PNG_EXPORT(void, png_read_png) PNGARG((png_structp png_ptr,
2283 extern PNG_EXPORT(void, png_write_png) PNGARG((png_structp png_ptr,
2289 /* Define PNG_DEBUG at compile time for debugging information. Higher
2290 * numbers for PNG_DEBUG mean more debugging information. This has
2291 * only been added since version 0.95 so it is not implemented throughout
2292 * libpng yet, but more support will be added as needed.
2296 #if !defined(PNG_DEBUG_FILE) && defined(_MSC_VER)
2299 #define png_debug(l,m) _RPT0(_CRT_WARN,m)
2300 #define png_debug1(l,m,p1) _RPT1(_CRT_WARN,m,p1)
2301 #define png_debug2(l,m,p1,p2) _RPT2(_CRT_WARN,m,p1,p2)
2303 #else /* PNG_DEBUG_FILE || !_MSC_VER */
2304 #ifndef PNG_DEBUG_FILE
2305 #define PNG_DEBUG_FILE stderr
2306 #endif /* PNG_DEBUG_FILE */
2308 #define png_debug(l,m) \
2311 fprintf(PNG_DEBUG_FILE,"%s"m,(num_tabs==1 ? "\t" : \
2312 (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":"")))); \
2314 #define png_debug1(l,m,p1) \
2317 fprintf(PNG_DEBUG_FILE,"%s"m,(num_tabs==1 ? "\t" : \
2318 (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1); \
2320 #define png_debug2(l,m,p1,p2) \
2323 fprintf(PNG_DEBUG_FILE,"%s"m,(num_tabs==1 ? "\t" : \
2324 (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1,p2); \
2326 #endif /* (PNG_DEBUG > 1) */
2327 #endif /* _MSC_VER */
2328 #endif /* (PNG_DEBUG > 0) */
2329 #endif /* PNG_DEBUG */
2331 #define png_debug(l, m)
2334 #define png_debug1(l, m, p1)
2337 #define png_debug2(l, m, p1, p2)
2340 extern PNG_EXPORT(png_bytep,png_sig_bytes) PNGARG((void));
2342 extern PNG_EXPORT(png_charp,png_get_copyright) PNGARG((png_structp png_ptr));
2343 extern PNG_EXPORT(png_charp,png_get_header_ver) PNGARG((png_structp png_ptr));
2344 extern PNG_EXPORT(png_charp,png_get_header_version) PNGARG((png_structp png_ptr));
2345 extern PNG_EXPORT(png_charp,png_get_libpng_ver) PNGARG((png_structp png_ptr));
2347 #ifdef PNG_MNG_FEATURES_SUPPORTED
2348 extern PNG_EXPORT(png_uint_32,png_permit_mng_features) PNGARG((png_structp
2349 png_ptr, png_uint_32 mng_features_permitted));
2352 /* Added to version 1.2.0 */
2353 #if defined(PNG_ASSEMBLER_CODE_SUPPORTED)
2354 #define PNG_ASM_FLAG_MMX_SUPPORT_COMPILED 0x01 /* not user-settable */
2355 #define PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU 0x02 /* not user-settable */
2356 #define PNG_ASM_FLAG_MMX_READ_COMBINE_ROW 0x04
2357 #define PNG_ASM_FLAG_MMX_READ_INTERLACE 0x08
2358 #define PNG_ASM_FLAG_MMX_READ_FILTER_SUB 0x10
2359 #define PNG_ASM_FLAG_MMX_READ_FILTER_UP 0x20
2360 #define PNG_ASM_FLAG_MMX_READ_FILTER_AVG 0x40
2361 #define PNG_ASM_FLAG_MMX_READ_FILTER_PAETH 0x80
2362 #define PNG_ASM_FLAGS_INITIALIZED 0x80000000 /* not user-settable */
2364 #define PNG_MMX_READ_FLAGS ( PNG_ASM_FLAG_MMX_READ_COMBINE_ROW \
2365 | PNG_ASM_FLAG_MMX_READ_INTERLACE \
2366 | PNG_ASM_FLAG_MMX_READ_FILTER_SUB \
2367 | PNG_ASM_FLAG_MMX_READ_FILTER_UP \
2368 | PNG_ASM_FLAG_MMX_READ_FILTER_AVG \
2369 | PNG_ASM_FLAG_MMX_READ_FILTER_PAETH )
2370 #define PNG_MMX_WRITE_FLAGS ( 0 )
2372 #define PNG_MMX_FLAGS ( PNG_ASM_FLAG_MMX_SUPPORT_COMPILED \
2373 | PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU \
2374 | PNG_MMX_READ_FLAGS \
2375 | PNG_MMX_WRITE_FLAGS )
2377 #define PNG_SELECT_READ 1
2378 #define PNG_SELECT_WRITE 2
2381 #if !defined(PNG_1_0_X)
2383 extern PNG_EXPORT(png_uint_32,png_get_mmx_flagmask)
2384 PNGARG((int flag_select, int *compilerID));
2387 extern PNG_EXPORT(png_uint_32,png_get_asm_flagmask)
2388 PNGARG((int flag_select));
2391 extern PNG_EXPORT(png_uint_32,png_get_asm_flags)
2392 PNGARG((png_structp png_ptr));
2395 extern PNG_EXPORT(png_byte,png_get_mmx_bitdepth_threshold)
2396 PNGARG((png_structp png_ptr));
2399 extern PNG_EXPORT(png_uint_32,png_get_mmx_rowbytes_threshold)
2400 PNGARG((png_structp png_ptr));
2403 extern PNG_EXPORT(void,png_set_asm_flags)
2404 PNGARG((png_structp png_ptr, png_uint_32 asm_flags));
2407 extern PNG_EXPORT(void,png_set_mmx_thresholds)
2408 PNGARG((png_structp png_ptr, png_byte mmx_bitdepth_threshold,
2409 png_uint_32 mmx_rowbytes_threshold));
2411 #endif /* PNG_1_0_X */
2412 #endif /* PNG_ASSEMBLER_CODE_SUPPORTED */
2414 #if !defined(PNG_1_0_X)
2415 /* png.c, pnggccrd.c, or pngvcrd.c */
2416 extern PNG_EXPORT(int,png_mmx_support) PNGARG((void));
2418 /* Strip the prepended error numbers ("#nnn ") from error and warning
2419 * messages before passing them to the error or warning handler. */
2420 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
2421 extern PNG_EXPORT(void,png_set_strip_error_numbers) PNGARG((png_structp
2422 png_ptr, png_uint_32 strip_mode));
2424 #endif /* PNG_1_0_X */
2426 /* Maintainer: Put new public prototypes here ^, in libpng.3, and project defs */
2428 #define PNG_HEADER_VERSION_STRING \
2429 " libpng version 1.2.5 - October 3, 2002 (header)\n"
2431 #ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
2432 /* With these routines we avoid an integer divide, which will be slower on
2433 * most machines. However, it does take more operations than the corresponding
2434 * divide method, so it may be slower on a few RISC systems. There are two
2435 * shifts (by 8 or 16 bits) and an addition, versus a single integer divide.
2437 * Note that the rounding factors are NOT supposed to be the same! 128 and
2438 * 32768 are correct for the NODIV code; 127 and 32767 are correct for the
2441 * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
2444 /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */
2446 # define png_composite(composite, fg, alpha, bg) \
2447 { png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) * (png_uint_16)(alpha) \
2448 + (png_uint_16)(bg)*(png_uint_16)(255 - \
2449 (png_uint_16)(alpha)) + (png_uint_16)128); \
2450 (composite) = (png_byte)((temp + (temp >> 8)) >> 8); }
2452 # define png_composite_16(composite, fg, alpha, bg) \
2453 { png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) * (png_uint_32)(alpha) \
2454 + (png_uint_32)(bg)*(png_uint_32)(65535L - \
2455 (png_uint_32)(alpha)) + (png_uint_32)32768L); \
2456 (composite) = (png_uint_16)((temp + (temp >> 16)) >> 16); }
2458 #else /* standard method using integer division */
2460 # define png_composite(composite, fg, alpha, bg) \
2461 (composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) + \
2462 (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \
2463 (png_uint_16)127) / 255)
2465 # define png_composite_16(composite, fg, alpha, bg) \
2466 (composite) = (png_uint_16)(((png_uint_32)(fg) * (png_uint_32)(alpha) + \
2467 (png_uint_32)(bg)*(png_uint_32)(65535L - (png_uint_32)(alpha)) + \
2468 (png_uint_32)32767) / (png_uint_32)65535L)
2470 #endif /* PNG_READ_COMPOSITE_NODIV_SUPPORTED */
2472 /* These next functions are used internally in the code. They generally
2473 * shouldn't be used unless you are writing code to add or replace some
2474 * functionality in libpng. More information about most functions can
2475 * be found in the files where the functions are located.
2478 #if defined(PNG_INTERNAL)
2480 /* Various modes of operation. Note that after an init, mode is set to
2481 * zero automatically when the structure is created.
2483 #define PNG_HAVE_IHDR 0x01
2484 #define PNG_HAVE_PLTE 0x02
2485 #define PNG_HAVE_IDAT 0x04
2486 #define PNG_AFTER_IDAT 0x08
2487 #define PNG_HAVE_IEND 0x10
2488 #define PNG_HAVE_gAMA 0x20
2489 #define PNG_HAVE_cHRM 0x40
2490 #define PNG_HAVE_sRGB 0x80
2491 #define PNG_HAVE_CHUNK_HEADER 0x100
2492 #define PNG_WROTE_tIME 0x200
2493 #define PNG_WROTE_INFO_BEFORE_PLTE 0x400
2494 #define PNG_BACKGROUND_IS_GRAY 0x800
2495 #define PNG_HAVE_PNG_SIGNATURE 0x1000
2497 /* flags for the transformations the PNG library does on the image data */
2498 #define PNG_BGR 0x0001
2499 #define PNG_INTERLACE 0x0002
2500 #define PNG_PACK 0x0004
2501 #define PNG_SHIFT 0x0008
2502 #define PNG_SWAP_BYTES 0x0010
2503 #define PNG_INVERT_MONO 0x0020
2504 #define PNG_DITHER 0x0040
2505 #define PNG_BACKGROUND 0x0080
2506 #define PNG_BACKGROUND_EXPAND 0x0100
2508 #define PNG_16_TO_8 0x0400
2509 #define PNG_RGBA 0x0800
2510 #define PNG_EXPAND 0x1000
2511 #define PNG_GAMMA 0x2000
2512 #define PNG_GRAY_TO_RGB 0x4000
2513 #define PNG_FILLER 0x8000L
2514 #define PNG_PACKSWAP 0x10000L
2515 #define PNG_SWAP_ALPHA 0x20000L
2516 #define PNG_STRIP_ALPHA 0x40000L
2517 #define PNG_INVERT_ALPHA 0x80000L
2518 #define PNG_USER_TRANSFORM 0x100000L
2519 #define PNG_RGB_TO_GRAY_ERR 0x200000L
2520 #define PNG_RGB_TO_GRAY_WARN 0x400000L
2521 #define PNG_RGB_TO_GRAY 0x600000L /* two bits, RGB_TO_GRAY_ERR|WARN */
2523 /* flags for png_create_struct */
2524 #define PNG_STRUCT_PNG 0x0001
2525 #define PNG_STRUCT_INFO 0x0002
2527 /* Scaling factor for filter heuristic weighting calculations */
2528 #define PNG_WEIGHT_SHIFT 8
2529 #define PNG_WEIGHT_FACTOR (1<<(PNG_WEIGHT_SHIFT))
2530 #define PNG_COST_SHIFT 3
2531 #define PNG_COST_FACTOR (1<<(PNG_COST_SHIFT))
2533 /* flags for the png_ptr->flags rather than declaring a byte for each one */
2534 #define PNG_FLAG_ZLIB_CUSTOM_STRATEGY 0x0001
2535 #define PNG_FLAG_ZLIB_CUSTOM_LEVEL 0x0002
2536 #define PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL 0x0004
2537 #define PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS 0x0008
2538 #define PNG_FLAG_ZLIB_CUSTOM_METHOD 0x0010
2539 #define PNG_FLAG_ZLIB_FINISHED 0x0020
2540 #define PNG_FLAG_ROW_INIT 0x0040
2541 #define PNG_FLAG_FILLER_AFTER 0x0080
2542 #define PNG_FLAG_CRC_ANCILLARY_USE 0x0100
2543 #define PNG_FLAG_CRC_ANCILLARY_NOWARN 0x0200
2544 #define PNG_FLAG_CRC_CRITICAL_USE 0x0400
2545 #define PNG_FLAG_CRC_CRITICAL_IGNORE 0x0800
2546 #define PNG_FLAG_FREE_PLTE 0x1000
2547 #define PNG_FLAG_FREE_TRNS 0x2000
2548 #define PNG_FLAG_FREE_HIST 0x4000
2549 #define PNG_FLAG_KEEP_UNKNOWN_CHUNKS 0x8000L
2550 #define PNG_FLAG_KEEP_UNSAFE_CHUNKS 0x10000L
2551 #define PNG_FLAG_LIBRARY_MISMATCH 0x20000L
2552 #define PNG_FLAG_STRIP_ERROR_NUMBERS 0x40000L
2553 #define PNG_FLAG_STRIP_ERROR_TEXT 0x80000L
2554 #define PNG_FLAG_MALLOC_NULL_MEM_OK 0x100000L
2556 /* For use in png_set_keep_unknown, png_handle_as_unknown */
2557 #define HANDLE_CHUNK_AS_DEFAULT 0
2558 #define HANDLE_CHUNK_NEVER 1
2559 #define HANDLE_CHUNK_IF_SAFE 2
2560 #define HANDLE_CHUNK_ALWAYS 3
2562 #define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \
2563 PNG_FLAG_CRC_ANCILLARY_NOWARN)
2565 #define PNG_FLAG_CRC_CRITICAL_MASK (PNG_FLAG_CRC_CRITICAL_USE | \
2566 PNG_FLAG_CRC_CRITICAL_IGNORE)
2568 #define PNG_FLAG_CRC_MASK (PNG_FLAG_CRC_ANCILLARY_MASK | \
2569 PNG_FLAG_CRC_CRITICAL_MASK)
2571 /* save typing and make code easier to understand */
2572 #define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \
2573 abs((int)((c1).green) - (int)((c2).green)) + \
2574 abs((int)((c1).blue) - (int)((c2).blue)))
2576 /* variables declared in png.c - only it needs to define PNG_NO_EXTERN */
2577 #if !defined(PNG_NO_EXTERN) || defined(PNG_ALWAYS_EXTERN)
2578 /* place to hold the signature string for a PNG file. */
2579 #ifdef PNG_USE_GLOBAL_ARRAYS
2580 PNG_EXPORT_VAR (const png_byte FARDATA) png_sig[8];
2582 #define png_sig png_sig_bytes(NULL)
2584 #endif /* PNG_NO_EXTERN */
2586 /* Constant strings for known chunk types. If you need to add a chunk,
2587 * define the name here, and add an invocation of the macro in png.c and
2588 * wherever it's needed.
2590 #define PNG_IHDR const png_byte png_IHDR[5] = { 73, 72, 68, 82, '\0'}
2591 #define PNG_IDAT const png_byte png_IDAT[5] = { 73, 68, 65, 84, '\0'}
2592 #define PNG_IEND const png_byte png_IEND[5] = { 73, 69, 78, 68, '\0'}
2593 #define PNG_PLTE const png_byte png_PLTE[5] = { 80, 76, 84, 69, '\0'}
2594 #define PNG_bKGD const png_byte png_bKGD[5] = { 98, 75, 71, 68, '\0'}
2595 #define PNG_cHRM const png_byte png_cHRM[5] = { 99, 72, 82, 77, '\0'}
2596 #define PNG_gAMA const png_byte png_gAMA[5] = {103, 65, 77, 65, '\0'}
2597 #define PNG_hIST const png_byte png_hIST[5] = {104, 73, 83, 84, '\0'}
2598 #define PNG_iCCP const png_byte png_iCCP[5] = {105, 67, 67, 80, '\0'}
2599 #define PNG_iTXt const png_byte png_iTXt[5] = {105, 84, 88, 116, '\0'}
2600 #define PNG_oFFs const png_byte png_oFFs[5] = {111, 70, 70, 115, '\0'}
2601 #define PNG_pCAL const png_byte png_pCAL[5] = {112, 67, 65, 76, '\0'}
2602 #define PNG_sCAL const png_byte png_sCAL[5] = {115, 67, 65, 76, '\0'}
2603 #define PNG_pHYs const png_byte png_pHYs[5] = {112, 72, 89, 115, '\0'}
2604 #define PNG_sBIT const png_byte png_sBIT[5] = {115, 66, 73, 84, '\0'}
2605 #define PNG_sPLT const png_byte png_sPLT[5] = {115, 80, 76, 84, '\0'}
2606 #define PNG_sRGB const png_byte png_sRGB[5] = {115, 82, 71, 66, '\0'}
2607 #define PNG_tEXt const png_byte png_tEXt[5] = {116, 69, 88, 116, '\0'}
2608 #define PNG_tIME const png_byte png_tIME[5] = {116, 73, 77, 69, '\0'}
2609 #define PNG_tRNS const png_byte png_tRNS[5] = {116, 82, 78, 83, '\0'}
2610 #define PNG_zTXt const png_byte png_zTXt[5] = {122, 84, 88, 116, '\0'}
2612 #ifdef PNG_USE_GLOBAL_ARRAYS
2613 PNG_EXPORT_VAR (const png_byte FARDATA) png_IHDR[5];
2614 PNG_EXPORT_VAR (const png_byte FARDATA) png_IDAT[5];
2615 PNG_EXPORT_VAR (const png_byte FARDATA) png_IEND[5];
2616 PNG_EXPORT_VAR (const png_byte FARDATA) png_PLTE[5];
2617 PNG_EXPORT_VAR (const png_byte FARDATA) png_bKGD[5];
2618 PNG_EXPORT_VAR (const png_byte FARDATA) png_cHRM[5];
2619 PNG_EXPORT_VAR (const png_byte FARDATA) png_gAMA[5];
2620 PNG_EXPORT_VAR (const png_byte FARDATA) png_hIST[5];
2621 PNG_EXPORT_VAR (const png_byte FARDATA) png_iCCP[5];
2622 PNG_EXPORT_VAR (const png_byte FARDATA) png_iTXt[5];
2623 PNG_EXPORT_VAR (const png_byte FARDATA) png_oFFs[5];
2624 PNG_EXPORT_VAR (const png_byte FARDATA) png_pCAL[5];
2625 PNG_EXPORT_VAR (const png_byte FARDATA) png_sCAL[5];
2626 PNG_EXPORT_VAR (const png_byte FARDATA) png_pHYs[5];
2627 PNG_EXPORT_VAR (const png_byte FARDATA) png_sBIT[5];
2628 PNG_EXPORT_VAR (const png_byte FARDATA) png_sPLT[5];
2629 PNG_EXPORT_VAR (const png_byte FARDATA) png_sRGB[5];
2630 PNG_EXPORT_VAR (const png_byte FARDATA) png_tEXt[5];
2631 PNG_EXPORT_VAR (const png_byte FARDATA) png_tIME[5];
2632 PNG_EXPORT_VAR (const png_byte FARDATA) png_tRNS[5];
2633 PNG_EXPORT_VAR (const png_byte FARDATA) png_zTXt[5];
2634 #endif /* PNG_USE_GLOBAL_ARRAYS */
2637 /* Inline macros to do direct reads of bytes from the input buffer. These
2638 * require that you are using an architecture that uses PNG byte ordering
2639 * (MSB first) and supports unaligned data storage. I think that PowerPC
2640 * in big-endian mode and 680x0 are the only ones that will support this.
2641 * The x86 line of processors definitely do not. The png_get_int_32()
2642 * routine also assumes we are using two's complement format for negative
2643 * values, which is almost certainly true.
2645 #if defined(PNG_READ_BIG_ENDIAN_SUPPORTED)
2646 # if defined(PNG_pCAL_SUPPORTED) || defined(PNG_oFFs_SUPPORTED)
2647 # define png_get_int_32(buf) ( *((png_int_32p) (buf)))
2649 # define png_get_uint_32(buf) ( *((png_uint_32p) (buf)))
2650 # define png_get_uint_16(buf) ( *((png_uint_16p) (buf)))
2652 # if defined(PNG_pCAL_SUPPORTED) || defined(PNG_oFFs_SUPPORTED)
2653 PNG_EXTERN png_int_32 png_get_int_32 PNGARG((png_bytep buf));
2655 PNG_EXTERN png_uint_32 png_get_uint_32 PNGARG((png_bytep buf));
2656 PNG_EXTERN png_uint_16 png_get_uint_16 PNGARG((png_bytep buf));
2657 #endif /* !PNG_READ_BIG_ENDIAN_SUPPORTED */
2659 /* Initialize png_ptr struct for reading, and allocate any other memory.
2660 * (old interface - DEPRECATED - use png_create_read_struct instead).
2662 extern PNG_EXPORT(void,png_read_init) PNGARG((png_structp png_ptr));
2663 #undef png_read_init
2664 #define png_read_init(png_ptr) png_read_init_3(&png_ptr, \
2665 PNG_LIBPNG_VER_STRING, sizeof(png_struct));
2666 extern PNG_EXPORT(void,png_read_init_3) PNGARG((png_structpp ptr_ptr,
2667 png_const_charp user_png_ver, png_size_t png_struct_size));
2668 extern PNG_EXPORT(void,png_read_init_2) PNGARG((png_structp png_ptr,
2669 png_const_charp user_png_ver, png_size_t png_struct_size, png_size_t
2672 /* Initialize png_ptr struct for writing, and allocate any other memory.
2673 * (old interface - DEPRECATED - use png_create_write_struct instead).
2675 extern PNG_EXPORT(void,png_write_init) PNGARG((png_structp png_ptr));
2676 #undef png_write_init
2677 #define png_write_init(png_ptr) png_write_init_3(&png_ptr, \
2678 PNG_LIBPNG_VER_STRING, sizeof(png_struct));
2679 extern PNG_EXPORT(void,png_write_init_3) PNGARG((png_structpp ptr_ptr,
2680 png_const_charp user_png_ver, png_size_t png_struct_size));
2681 extern PNG_EXPORT(void,png_write_init_2) PNGARG((png_structp png_ptr,
2682 png_const_charp user_png_ver, png_size_t png_struct_size, png_size_t
2685 /* Allocate memory for an internal libpng struct */
2686 PNG_EXTERN png_voidp png_create_struct PNGARG((int type));
2688 /* Free memory from internal libpng struct */
2689 PNG_EXTERN void png_destroy_struct PNGARG((png_voidp struct_ptr));
2691 PNG_EXTERN png_voidp png_create_struct_2 PNGARG((int type, png_malloc_ptr
2692 malloc_fn, png_voidp mem_ptr));
2693 PNG_EXTERN void png_destroy_struct_2 PNGARG((png_voidp struct_ptr,
2694 png_free_ptr free_fn, png_voidp mem_ptr));
2696 /* Free any memory that info_ptr points to and reset struct. */
2697 PNG_EXTERN void png_info_destroy PNGARG((png_structp png_ptr,
2698 png_infop info_ptr));
2701 /* Function to allocate memory for zlib. */
2702 PNG_EXTERN voidpf png_zalloc PNGARG((voidpf png_ptr, uInt items, uInt size));
2704 /* Function to free memory for zlib */
2705 PNG_EXTERN void png_zfree PNGARG((voidpf png_ptr, voidpf ptr));
2707 /* Next four functions are used internally as callbacks. PNGAPI is required
2708 * but not PNG_EXPORT. PNGAPI added at libpng version 1.2.3. */
2710 PNG_EXTERN void PNGAPI png_default_read_data PNGARG((png_structp png_ptr,
2711 png_bytep data, png_size_t length));
2713 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
2714 PNG_EXTERN void PNGAPI png_push_fill_buffer PNGARG((png_structp png_ptr,
2715 png_bytep buffer, png_size_t length));
2718 PNG_EXTERN void PNGAPI png_default_write_data PNGARG((png_structp png_ptr,
2719 png_bytep data, png_size_t length));
2721 #if defined(PNG_WRITE_FLUSH_SUPPORTED)
2722 #if !defined(PNG_NO_STDIO)
2723 PNG_EXTERN void PNGAPI png_default_flush PNGARG((png_structp png_ptr));
2726 #else /* PNG_1_0_X */
2727 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
2728 PNG_EXTERN void png_push_fill_buffer PNGARG((png_structp png_ptr,
2729 png_bytep buffer, png_size_t length));
2731 #endif /* PNG_1_0_X */
2733 /* Reset the CRC variable */
2734 PNG_EXTERN void png_reset_crc PNGARG((png_structp png_ptr));
2736 /* Write the "data" buffer to whatever output you are using. */
2737 PNG_EXTERN void png_write_data PNGARG((png_structp png_ptr, png_bytep data,
2738 png_size_t length));
2740 /* Read data from whatever input you are using into the "data" buffer */
2741 PNG_EXTERN void png_read_data PNGARG((png_structp png_ptr, png_bytep data,
2742 png_size_t length));
2744 /* Read bytes into buf, and update png_ptr->crc */
2745 PNG_EXTERN void png_crc_read PNGARG((png_structp png_ptr, png_bytep buf,
2746 png_size_t length));
2748 /* Decompress data in a chunk that uses compression */
2749 #if defined(PNG_zTXt_SUPPORTED) || defined(PNG_iTXt_SUPPORTED) || \
2750 defined(PNG_iCCP_SUPPORTED) || defined(PNG_sPLT_SUPPORTED)
2751 PNG_EXTERN png_charp png_decompress_chunk PNGARG((png_structp png_ptr,
2752 int comp_type, png_charp chunkdata, png_size_t chunklength,
2753 png_size_t prefix_length, png_size_t *data_length));
2756 /* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */
2757 PNG_EXTERN int png_crc_finish PNGARG((png_structp png_ptr, png_uint_32 skip));
2759 /* Read the CRC from the file and compare it to the libpng calculated CRC */
2760 PNG_EXTERN int png_crc_error PNGARG((png_structp png_ptr));
2762 /* Calculate the CRC over a section of data. Note that we are only
2763 * passing a maximum of 64K on systems that have this as a memory limit,
2764 * since this is the maximum buffer size we can specify.
2766 PNG_EXTERN void png_calculate_crc PNGARG((png_structp png_ptr, png_bytep ptr,
2767 png_size_t length));
2769 #if defined(PNG_WRITE_FLUSH_SUPPORTED)
2770 PNG_EXTERN void png_flush PNGARG((png_structp png_ptr));
2774 /* Place a 32-bit number into a buffer in PNG byte order (big-endian).
2775 * The only currently known PNG chunks that use signed numbers are
2776 * the ancillary extension chunks, oFFs and pCAL.
2778 PNG_EXTERN void png_save_uint_32 PNGARG((png_bytep buf, png_uint_32 i));
2780 #if defined(PNG_WRITE_pCAL_SUPPORTED) || defined(PNG_WRITE_oFFs_SUPPORTED)
2781 PNG_EXTERN void png_save_int_32 PNGARG((png_bytep buf, png_int_32 i));
2784 /* Place a 16-bit number into a buffer in PNG byte order.
2785 * The parameter is declared unsigned int, not png_uint_16,
2786 * just to avoid potential problems on pre-ANSI C compilers.
2788 PNG_EXTERN void png_save_uint_16 PNGARG((png_bytep buf, unsigned int i));
2790 /* simple function to write the signature */
2791 PNG_EXTERN void png_write_sig PNGARG((png_structp png_ptr));
2793 /* write various chunks */
2795 /* Write the IHDR chunk, and update the png_struct with the necessary
2798 PNG_EXTERN void png_write_IHDR PNGARG((png_structp png_ptr, png_uint_32 width,
2800 int bit_depth, int color_type, int compression_method, int filter_method,
2801 int interlace_method));
2803 PNG_EXTERN void png_write_PLTE PNGARG((png_structp png_ptr, png_colorp palette,
2804 png_uint_32 num_pal));
2806 PNG_EXTERN void png_write_IDAT PNGARG((png_structp png_ptr, png_bytep data,
2807 png_size_t length));
2809 PNG_EXTERN void png_write_IEND PNGARG((png_structp png_ptr));
2811 #if defined(PNG_WRITE_gAMA_SUPPORTED)
2812 #ifdef PNG_FLOATING_POINT_SUPPORTED
2813 PNG_EXTERN void png_write_gAMA PNGARG((png_structp png_ptr, double file_gamma));
2815 #ifdef PNG_FIXED_POINT_SUPPORTED
2816 PNG_EXTERN void png_write_gAMA_fixed PNGARG((png_structp png_ptr, png_fixed_point
2821 #if defined(PNG_WRITE_sBIT_SUPPORTED)
2822 PNG_EXTERN void png_write_sBIT PNGARG((png_structp png_ptr, png_color_8p sbit,
2826 #if defined(PNG_WRITE_cHRM_SUPPORTED)
2827 #ifdef PNG_FLOATING_POINT_SUPPORTED
2828 PNG_EXTERN void png_write_cHRM PNGARG((png_structp png_ptr,
2829 double white_x, double white_y,
2830 double red_x, double red_y, double green_x, double green_y,
2831 double blue_x, double blue_y));
2833 #ifdef PNG_FIXED_POINT_SUPPORTED
2834 PNG_EXTERN void png_write_cHRM_fixed PNGARG((png_structp png_ptr,
2835 png_fixed_point int_white_x, png_fixed_point int_white_y,
2836 png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
2837 int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
2838 png_fixed_point int_blue_y));
2842 #if defined(PNG_WRITE_sRGB_SUPPORTED)
2843 PNG_EXTERN void png_write_sRGB PNGARG((png_structp png_ptr,
2847 #if defined(PNG_WRITE_iCCP_SUPPORTED)
2848 PNG_EXTERN void png_write_iCCP PNGARG((png_structp png_ptr,
2849 png_charp name, int compression_type,
2850 png_charp profile, int proflen));
2851 /* Note to maintainer: profile should be png_bytep */
2854 #if defined(PNG_WRITE_sPLT_SUPPORTED)
2855 PNG_EXTERN void png_write_sPLT PNGARG((png_structp png_ptr,
2856 png_sPLT_tp palette));
2859 #if defined(PNG_WRITE_tRNS_SUPPORTED)
2860 PNG_EXTERN void png_write_tRNS PNGARG((png_structp png_ptr, png_bytep trans,
2861 png_color_16p values, int number, int color_type));
2864 #if defined(PNG_WRITE_bKGD_SUPPORTED)
2865 PNG_EXTERN void png_write_bKGD PNGARG((png_structp png_ptr,
2866 png_color_16p values, int color_type));
2869 #if defined(PNG_WRITE_hIST_SUPPORTED)
2870 PNG_EXTERN void png_write_hIST PNGARG((png_structp png_ptr, png_uint_16p hist,
2874 #if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \
2875 defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
2876 PNG_EXTERN png_size_t png_check_keyword PNGARG((png_structp png_ptr,
2877 png_charp key, png_charpp new_key));
2880 #if defined(PNG_WRITE_tEXt_SUPPORTED)
2881 PNG_EXTERN void png_write_tEXt PNGARG((png_structp png_ptr, png_charp key,
2882 png_charp text, png_size_t text_len));
2885 #if defined(PNG_WRITE_zTXt_SUPPORTED)
2886 PNG_EXTERN void png_write_zTXt PNGARG((png_structp png_ptr, png_charp key,
2887 png_charp text, png_size_t text_len, int compression));
2890 #if defined(PNG_WRITE_iTXt_SUPPORTED)
2891 PNG_EXTERN void png_write_iTXt PNGARG((png_structp png_ptr,
2892 int compression, png_charp key, png_charp lang, png_charp lang_key,
2896 #if defined(PNG_TEXT_SUPPORTED) /* Added at version 1.0.14 and 1.2.4 */
2897 PNG_EXTERN int png_set_text_2 PNGARG((png_structp png_ptr,
2898 png_infop info_ptr, png_textp text_ptr, int num_text));
2901 #if defined(PNG_WRITE_oFFs_SUPPORTED)
2902 PNG_EXTERN void png_write_oFFs PNGARG((png_structp png_ptr,
2903 png_int_32 x_offset, png_int_32 y_offset, int unit_type));
2906 #if defined(PNG_WRITE_pCAL_SUPPORTED)
2907 PNG_EXTERN void png_write_pCAL PNGARG((png_structp png_ptr, png_charp purpose,
2908 png_int_32 X0, png_int_32 X1, int type, int nparams,
2909 png_charp units, png_charpp params));
2912 #if defined(PNG_WRITE_pHYs_SUPPORTED)
2913 PNG_EXTERN void png_write_pHYs PNGARG((png_structp png_ptr,
2914 png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit,
2918 #if defined(PNG_WRITE_tIME_SUPPORTED)
2919 PNG_EXTERN void png_write_tIME PNGARG((png_structp png_ptr,
2920 png_timep mod_time));
2923 #if defined(PNG_WRITE_sCAL_SUPPORTED)
2924 #if defined(PNG_FLOATING_POINT_SUPPORTED) && !defined(PNG_NO_STDIO)
2925 PNG_EXTERN void png_write_sCAL PNGARG((png_structp png_ptr,
2926 int unit, double width, double height));
2928 #ifdef PNG_FIXED_POINT_SUPPORTED
2929 PNG_EXTERN void png_write_sCAL_s PNGARG((png_structp png_ptr,
2930 int unit, png_charp width, png_charp height));
2935 /* Called when finished processing a row of data */
2936 PNG_EXTERN void png_write_finish_row PNGARG((png_structp png_ptr));
2938 /* Internal use only. Called before first row of data */
2939 PNG_EXTERN void png_write_start_row PNGARG((png_structp png_ptr));
2941 #if defined(PNG_READ_GAMMA_SUPPORTED)
2942 PNG_EXTERN void png_build_gamma_table PNGARG((png_structp png_ptr));
2945 /* combine a row of data, dealing with alpha, etc. if requested */
2946 PNG_EXTERN void png_combine_row PNGARG((png_structp png_ptr, png_bytep row,
2949 #if defined(PNG_READ_INTERLACING_SUPPORTED)
2950 /* expand an interlaced row */
2951 /* OLD pre-1.0.9 interface:
2952 PNG_EXTERN void png_do_read_interlace PNGARG((png_row_infop row_info,
2953 png_bytep row, int pass, png_uint_32 transformations));
2955 PNG_EXTERN void png_do_read_interlace PNGARG((png_structp png_ptr));
2958 /* GRR TO DO (2.0 or whenever): simplify other internal calling interfaces */
2960 #if defined(PNG_WRITE_INTERLACING_SUPPORTED)
2961 /* grab pixels out of a row for an interlaced pass */
2962 PNG_EXTERN void png_do_write_interlace PNGARG((png_row_infop row_info,
2963 png_bytep row, int pass));
2966 /* unfilter a row */
2967 PNG_EXTERN void png_read_filter_row PNGARG((png_structp png_ptr,
2968 png_row_infop row_info, png_bytep row, png_bytep prev_row, int filter));
2970 /* Choose the best filter to use and filter the row data */
2971 PNG_EXTERN void png_write_find_filter PNGARG((png_structp png_ptr,
2972 png_row_infop row_info));
2974 /* Write out the filtered row. */
2975 PNG_EXTERN void png_write_filtered_row PNGARG((png_structp png_ptr,
2976 png_bytep filtered_row));
2977 /* finish a row while reading, dealing with interlacing passes, etc. */
2978 PNG_EXTERN void png_read_finish_row PNGARG((png_structp png_ptr));
2980 /* initialize the row buffers, etc. */
2981 PNG_EXTERN void png_read_start_row PNGARG((png_structp png_ptr));
2982 /* optional call to update the users info structure */
2983 PNG_EXTERN void png_read_transform_info PNGARG((png_structp png_ptr,
2984 png_infop info_ptr));
2986 /* these are the functions that do the transformations */
2987 #if defined(PNG_READ_FILLER_SUPPORTED)
2988 PNG_EXTERN void png_do_read_filler PNGARG((png_row_infop row_info,
2989 png_bytep row, png_uint_32 filler, png_uint_32 flags));
2992 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED)
2993 PNG_EXTERN void png_do_read_swap_alpha PNGARG((png_row_infop row_info,
2997 #if defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
2998 PNG_EXTERN void png_do_write_swap_alpha PNGARG((png_row_infop row_info,
3002 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)
3003 PNG_EXTERN void png_do_read_invert_alpha PNGARG((png_row_infop row_info,
3007 #if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
3008 PNG_EXTERN void png_do_write_invert_alpha PNGARG((png_row_infop row_info,
3012 #if defined(PNG_WRITE_FILLER_SUPPORTED) || \
3013 defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
3014 PNG_EXTERN void png_do_strip_filler PNGARG((png_row_infop row_info,
3015 png_bytep row, png_uint_32 flags));
3018 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
3019 PNG_EXTERN void png_do_swap PNGARG((png_row_infop row_info, png_bytep row));
3022 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || defined(PNG_WRITE_PACKSWAP_SUPPORTED)
3023 PNG_EXTERN void png_do_packswap PNGARG((png_row_infop row_info, png_bytep row));
3026 #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
3027 PNG_EXTERN int png_do_rgb_to_gray PNGARG((png_structp png_ptr, png_row_infop
3028 row_info, png_bytep row));
3031 #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
3032 PNG_EXTERN void png_do_gray_to_rgb PNGARG((png_row_infop row_info,
3036 #if defined(PNG_READ_PACK_SUPPORTED)
3037 PNG_EXTERN void png_do_unpack PNGARG((png_row_infop row_info, png_bytep row));
3040 #if defined(PNG_READ_SHIFT_SUPPORTED)
3041 PNG_EXTERN void png_do_unshift PNGARG((png_row_infop row_info, png_bytep row,
3042 png_color_8p sig_bits));
3045 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
3046 PNG_EXTERN void png_do_invert PNGARG((png_row_infop row_info, png_bytep row));
3049 #if defined(PNG_READ_16_TO_8_SUPPORTED)
3050 PNG_EXTERN void png_do_chop PNGARG((png_row_infop row_info, png_bytep row));
3053 #if defined(PNG_READ_DITHER_SUPPORTED)
3054 PNG_EXTERN void png_do_dither PNGARG((png_row_infop row_info,
3055 png_bytep row, png_bytep palette_lookup, png_bytep dither_lookup));
3057 # if defined(PNG_CORRECT_PALETTE_SUPPORTED)
3058 PNG_EXTERN void png_correct_palette PNGARG((png_structp png_ptr,
3059 png_colorp palette, int num_palette));
3063 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
3064 PNG_EXTERN void png_do_bgr PNGARG((png_row_infop row_info, png_bytep row));
3067 #if defined(PNG_WRITE_PACK_SUPPORTED)
3068 PNG_EXTERN void png_do_pack PNGARG((png_row_infop row_info,
3069 png_bytep row, png_uint_32 bit_depth));
3072 #if defined(PNG_WRITE_SHIFT_SUPPORTED)
3073 PNG_EXTERN void png_do_shift PNGARG((png_row_infop row_info, png_bytep row,
3074 png_color_8p bit_depth));
3077 #if defined(PNG_READ_BACKGROUND_SUPPORTED)
3078 #if defined(PNG_READ_GAMMA_SUPPORTED)
3079 PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info, png_bytep row,
3080 png_color_16p trans_values, png_color_16p background,
3081 png_color_16p background_1,
3082 png_bytep gamma_table, png_bytep gamma_from_1, png_bytep gamma_to_1,
3083 png_uint_16pp gamma_16, png_uint_16pp gamma_16_from_1,
3084 png_uint_16pp gamma_16_to_1, int gamma_shift));
3086 PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info, png_bytep row,
3087 png_color_16p trans_values, png_color_16p background));
3091 #if defined(PNG_READ_GAMMA_SUPPORTED)
3092 PNG_EXTERN void png_do_gamma PNGARG((png_row_infop row_info, png_bytep row,
3093 png_bytep gamma_table, png_uint_16pp gamma_16_table,
3097 #if defined(PNG_READ_EXPAND_SUPPORTED)
3098 PNG_EXTERN void png_do_expand_palette PNGARG((png_row_infop row_info,
3099 png_bytep row, png_colorp palette, png_bytep trans, int num_trans));
3100 PNG_EXTERN void png_do_expand PNGARG((png_row_infop row_info,
3101 png_bytep row, png_color_16p trans_value));
3104 /* The following decodes the appropriate chunks, and does error correction,
3105 * then calls the appropriate callback for the chunk if it is valid.
3108 /* decode the IHDR chunk */
3109 PNG_EXTERN void png_handle_IHDR PNGARG((png_structp png_ptr, png_infop info_ptr,
3110 png_uint_32 length));
3111 PNG_EXTERN void png_handle_PLTE PNGARG((png_structp png_ptr, png_infop info_ptr,
3112 png_uint_32 length));
3113 PNG_EXTERN void png_handle_IEND PNGARG((png_structp png_ptr, png_infop info_ptr,
3114 png_uint_32 length));
3116 #if defined(PNG_READ_bKGD_SUPPORTED)
3117 PNG_EXTERN void png_handle_bKGD PNGARG((png_structp png_ptr, png_infop info_ptr,
3118 png_uint_32 length));
3121 #if defined(PNG_READ_cHRM_SUPPORTED)
3122 PNG_EXTERN void png_handle_cHRM PNGARG((png_structp png_ptr, png_infop info_ptr,
3123 png_uint_32 length));
3126 #if defined(PNG_READ_gAMA_SUPPORTED)
3127 PNG_EXTERN void png_handle_gAMA PNGARG((png_structp png_ptr, png_infop info_ptr,
3128 png_uint_32 length));
3131 #if defined(PNG_READ_hIST_SUPPORTED)
3132 PNG_EXTERN void png_handle_hIST PNGARG((png_structp png_ptr, png_infop info_ptr,
3133 png_uint_32 length));
3136 #if defined(PNG_READ_iCCP_SUPPORTED)
3137 extern void png_handle_iCCP PNGARG((png_structp png_ptr, png_infop info_ptr,
3138 png_uint_32 length));
3139 #endif /* PNG_READ_iCCP_SUPPORTED */
3141 #if defined(PNG_READ_iTXt_SUPPORTED)
3142 PNG_EXTERN void png_handle_iTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
3143 png_uint_32 length));
3146 #if defined(PNG_READ_oFFs_SUPPORTED)
3147 PNG_EXTERN void png_handle_oFFs PNGARG((png_structp png_ptr, png_infop info_ptr,
3148 png_uint_32 length));
3151 #if defined(PNG_READ_pCAL_SUPPORTED)
3152 PNG_EXTERN void png_handle_pCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
3153 png_uint_32 length));
3156 #if defined(PNG_READ_pHYs_SUPPORTED)
3157 PNG_EXTERN void png_handle_pHYs PNGARG((png_structp png_ptr, png_infop info_ptr,
3158 png_uint_32 length));
3161 #if defined(PNG_READ_sBIT_SUPPORTED)
3162 PNG_EXTERN void png_handle_sBIT PNGARG((png_structp png_ptr, png_infop info_ptr,
3163 png_uint_32 length));
3166 #if defined(PNG_READ_sCAL_SUPPORTED)
3167 PNG_EXTERN void png_handle_sCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
3168 png_uint_32 length));
3171 #if defined(PNG_READ_sPLT_SUPPORTED)
3172 extern void png_handle_sPLT PNGARG((png_structp png_ptr, png_infop info_ptr,
3173 png_uint_32 length));
3174 #endif /* PNG_READ_sPLT_SUPPORTED */
3176 #if defined(PNG_READ_sRGB_SUPPORTED)
3177 PNG_EXTERN void png_handle_sRGB PNGARG((png_structp png_ptr, png_infop info_ptr,
3178 png_uint_32 length));
3181 #if defined(PNG_READ_tEXt_SUPPORTED)
3182 PNG_EXTERN void png_handle_tEXt PNGARG((png_structp png_ptr, png_infop info_ptr,
3183 png_uint_32 length));
3186 #if defined(PNG_READ_tIME_SUPPORTED)
3187 PNG_EXTERN void png_handle_tIME PNGARG((png_structp png_ptr, png_infop info_ptr,
3188 png_uint_32 length));
3191 #if defined(PNG_READ_tRNS_SUPPORTED)
3192 PNG_EXTERN void png_handle_tRNS PNGARG((png_structp png_ptr, png_infop info_ptr,
3193 png_uint_32 length));
3196 #if defined(PNG_READ_zTXt_SUPPORTED)
3197 PNG_EXTERN void png_handle_zTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
3198 png_uint_32 length));
3201 PNG_EXTERN void png_handle_unknown PNGARG((png_structp png_ptr,
3202 png_infop info_ptr, png_uint_32 length));
3204 PNG_EXTERN void png_check_chunk_name PNGARG((png_structp png_ptr,
3205 png_bytep chunk_name));
3207 /* handle the transformations for reading and writing */
3208 PNG_EXTERN void png_do_read_transformations PNGARG((png_structp png_ptr));
3209 PNG_EXTERN void png_do_write_transformations PNGARG((png_structp png_ptr));
3211 PNG_EXTERN void png_init_read_transformations PNGARG((png_structp png_ptr));
3213 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
3214 PNG_EXTERN void png_push_read_chunk PNGARG((png_structp png_ptr,
3215 png_infop info_ptr));
3216 PNG_EXTERN void png_push_read_sig PNGARG((png_structp png_ptr,
3217 png_infop info_ptr));
3218 PNG_EXTERN void png_push_check_crc PNGARG((png_structp png_ptr));
3219 PNG_EXTERN void png_push_crc_skip PNGARG((png_structp png_ptr,
3220 png_uint_32 length));
3221 PNG_EXTERN void png_push_crc_finish PNGARG((png_structp png_ptr));
3222 PNG_EXTERN void png_push_save_buffer PNGARG((png_structp png_ptr));
3223 PNG_EXTERN void png_push_restore_buffer PNGARG((png_structp png_ptr,
3224 png_bytep buffer, png_size_t buffer_length));
3225 PNG_EXTERN void png_push_read_IDAT PNGARG((png_structp png_ptr));
3226 PNG_EXTERN void png_process_IDAT_data PNGARG((png_structp png_ptr,
3227 png_bytep buffer, png_size_t buffer_length));
3228 PNG_EXTERN void png_push_process_row PNGARG((png_structp png_ptr));
3229 PNG_EXTERN void png_push_handle_unknown PNGARG((png_structp png_ptr,
3230 png_infop info_ptr, png_uint_32 length));
3231 PNG_EXTERN void png_push_have_info PNGARG((png_structp png_ptr,
3232 png_infop info_ptr));
3233 PNG_EXTERN void png_push_have_end PNGARG((png_structp png_ptr,
3234 png_infop info_ptr));
3235 PNG_EXTERN void png_push_have_row PNGARG((png_structp png_ptr, png_bytep row));
3236 PNG_EXTERN void png_push_read_end PNGARG((png_structp png_ptr,
3237 png_infop info_ptr));
3238 PNG_EXTERN void png_process_some_data PNGARG((png_structp png_ptr,
3239 png_infop info_ptr));
3240 PNG_EXTERN void png_read_push_finish_row PNGARG((png_structp png_ptr));
3241 #if defined(PNG_READ_tEXt_SUPPORTED)
3242 PNG_EXTERN void png_push_handle_tEXt PNGARG((png_structp png_ptr,
3243 png_infop info_ptr, png_uint_32 length));
3244 PNG_EXTERN void png_push_read_tEXt PNGARG((png_structp png_ptr,
3245 png_infop info_ptr));
3247 #if defined(PNG_READ_zTXt_SUPPORTED)
3248 PNG_EXTERN void png_push_handle_zTXt PNGARG((png_structp png_ptr,
3249 png_infop info_ptr, png_uint_32 length));
3250 PNG_EXTERN void png_push_read_zTXt PNGARG((png_structp png_ptr,
3251 png_infop info_ptr));
3253 #if defined(PNG_READ_iTXt_SUPPORTED)
3254 PNG_EXTERN void png_push_handle_iTXt PNGARG((png_structp png_ptr,
3255 png_infop info_ptr, png_uint_32 length));
3256 PNG_EXTERN void png_push_read_iTXt PNGARG((png_structp png_ptr,
3257 png_infop info_ptr));
3260 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
3262 #ifdef PNG_MNG_FEATURES_SUPPORTED
3263 PNG_EXTERN void png_do_read_intrapixel PNGARG((png_row_infop row_info,
3265 PNG_EXTERN void png_do_write_intrapixel PNGARG((png_row_infop row_info,
3269 #if defined(PNG_ASSEMBLER_CODE_SUPPORTED)
3270 /* png.c */ /* PRIVATE */
3271 PNG_EXTERN void png_init_mmx_flags PNGARG((png_structp png_ptr));
3273 /* Maintainer: Put new private prototypes here ^ and in libpngpf.3 */
3275 #endif /* PNG_INTERNAL */
3281 #endif /* PNG_VERSION_INFO_ONLY */
3282 /* do not put anything past this line */