2 /* png.h - header file for PNG reference library
4 * libpng version 1.2.0 - September 1, 2001
5 * Copyright (c) 1998-2001 Glenn Randers-Pehrson
6 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
7 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
9 * Authors and maintainers:
10 * libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
11 * libpng versions 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger
12 * libpng versions 0.97, January 1998, through 1.2.0 - September 1, 2001: Glenn
13 * See also "Contributing Authors", below.
15 * Note about libpng version numbers:
17 * Due to various miscommunications, unforeseen code incompatibilities
18 * and occasional factors outside the authors' control, version numbering
19 * on the library has not always been consistent and straightforward.
20 * The following table summarizes matters since version 0.89c, which was
21 * the first widely used release:
23 * source png.h png.h shared-lib
24 * version string int version
25 * ------- ------ ----- ----------
26 * 0.89c "1.0 beta 3" 0.89 89 1.0.89
27 * 0.90 "1.0 beta 4" 0.90 90 0.90 [should have been 2.0.90]
28 * 0.95 "1.0 beta 5" 0.95 95 0.95 [should have been 2.0.95]
29 * 0.96 "1.0 beta 6" 0.96 96 0.96 [should have been 2.0.96]
30 * 0.97b "1.00.97 beta 7" 1.00.97 97 1.0.1 [should have been 2.0.97]
31 * 0.97c 0.97 97 2.0.97
34 * 0.99a-m 0.99 99 2.0.99
35 * 1.00 1.00 100 2.1.0 [100 should be 10000]
36 * 1.0.0 (from here on, the 100 2.1.0 [100 should be 10000]
37 * 1.0.1 png.h string is 10001 2.1.0
38 * 1.0.1a-e identical to the 10002 from here on, the shared library
39 * 1.0.2 source version) 10002 is 2.V where V is the source code
40 * 1.0.2a-b 10003 version, except as noted.
45 * 1.0.5 (+ 2 patches) 10005
47 * 1.0.5e-r 10100 (not source compatible)
48 * 1.0.5s-v 10006 (not binary compatible)
49 * 1.0.6 (+ 3 patches) 10006 (still binary incompatible)
50 * 1.0.6d-f 10007 (still binary incompatible)
52 * 1.0.6h 10007 10.6h (testing xy.z so-numbering)
54 * 1.0.6j 10007 2.1.0.6j (incompatible with 1.0.0)
55 * 1.0.7beta11-14 DLLNUM 10007 2.1.0.7beta11-14 (binary compatible)
56 * 1.0.7beta15-18 1 10007 2.1.0.7beta15-18 (binary compatible)
57 * 1.0.7rc1-2 1 10007 2.1.0.7rc1-2 (binary compatible)
58 * 1.0.7 1 10007 (still compatible)
59 * 1.0.8beta1-4 1 10008 2.1.0.8beta1-4
60 * 1.0.8rc1 1 10008 2.1.0.8rc1
61 * 1.0.8 1 10008 2.1.0.8
62 * 1.0.9beta1-6 1 10009 2.1.0.9beta1-6
63 * 1.0.9rc1 1 10009 2.1.0.9rc1
64 * 1.0.9beta7-10 1 10009 2.1.0.9beta7-10
65 * 1.0.9rc2 1 10009 2.1.0.9rc2
66 * 1.0.9 1 10009 2.1.0.9
67 * 1.0.10beta1 1 10010 2.1.0.10beta1
68 * 1.0.10rc1 1 10010 2.1.0.10rc1
69 * 1.0.10 1 10010 2.1.0.10
70 * 1.0.11beta1-3 1 10011 2.1.0.11beta1-3
71 * 1.0.11rc1 1 10011 2.1.0.11rc1
72 * 1.0.11 1 10011 2.1.0.11
73 * 1.0.12beta1-2 2 10012 2.1.0.12beta1-2
74 * 1.0.12rc1 2 10012 2.1.0.12rc1
75 * 1.0.12 2 10012 2.1.0.12
76 * 1.1.0a-f - 10100 2.1.1.0a-f (branch abandoned)
77 * 1.2.0beta1-2 2 10200 2.1.2.0beta1-2
78 * 1.2.0beta3-4 3 10200 3.1.2.0beta3-4
80 * Henceforth the source version will match the shared-library major
81 * and minor numbers; the shared-library major version number will be
82 * used for changes in backward compatibility, as it is intended. The
83 * PNG_LIBPNG_VER macro, which is not used within libpng but is available
84 * for applications, is an unsigned integer of the form xyyzz corresponding
85 * to the source version x.y.z (leading zeros in y and z). Beta versions
86 * were given the previous public release number plus a letter, until
87 * version 1.0.6j; from then on they were given the upcoming public
88 * release number plus "betaNN" or "rcN".
90 * Binary incompatibility exists only when applications make direct access
91 * to the info_ptr or png_ptr members through png.h, and the compiled
92 * application is loaded with a different version of the library.
94 * DLLNUM will change each time there are forward or backward changes
95 * in binary compatibility (e.g., when a new feature is added).
97 * See libpng.txt or libpng.3 for more information. The PNG specification
98 * is available as RFC 2083 <ftp://ftp.uu.net/graphics/png/documents/>
99 * and as a W3C Recommendation <http://www.w3.org/TR/REC.png.html>
103 * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
105 * If you modify libpng you may insert additional notices immediately following
108 * libpng versions 1.0.7, July 1, 2000, through 1.2.0, September 1, 2001, are
109 * Copyright (c) 2000, 2001 Glenn Randers-Pehrson, and are
110 * distributed according to the same disclaimer and license as libpng-1.0.6
111 * with the following individuals added to the list of Contributing Authors
113 * Simon-Pierre Cadieux
117 * and with the following additions to the disclaimer:
119 * There is no warranty against interference with your enjoyment of the
120 * library or against infringement. There is no warranty that our
121 * efforts or the library will fulfill any of your particular purposes
122 * or needs. This library is provided with all faults, and the entire
123 * risk of satisfactory quality, performance, accuracy, and effort is with
126 * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
127 * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson
128 * Distributed according to the same disclaimer and license as libpng-0.96,
129 * with the following individuals added to the list of Contributing Authors:
132 * Glenn Randers-Pehrson
135 * libpng versions 0.89, June 1996, through 0.96, May 1997, are
136 * Copyright (c) 1996, 1997 Andreas Dilger
137 * Distributed according to the same disclaimer and license as libpng-0.88,
138 * with the following individuals added to the list of Contributing Authors:
147 * libpng versions 0.5, May 1995, through 0.88, January 1996, are
148 * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
150 * For the purposes of this copyright and license, "Contributing Authors"
151 * is defined as the following set of individuals:
159 * The PNG Reference Library is supplied "AS IS". The Contributing Authors
160 * and Group 42, Inc. disclaim all warranties, expressed or implied,
161 * including, without limitation, the warranties of merchantability and of
162 * fitness for any purpose. The Contributing Authors and Group 42, Inc.
163 * assume no liability for direct, indirect, incidental, special, exemplary,
164 * or consequential damages, which may result from the use of the PNG
165 * Reference Library, even if advised of the possibility of such damage.
167 * Permission is hereby granted to use, copy, modify, and distribute this
168 * source code, or portions hereof, for any purpose, without fee, subject
169 * to the following restrictions:
171 * 1. The origin of this source code must not be misrepresented.
173 * 2. Altered versions must be plainly marked as such and
174 * must not be misrepresented as being the original source.
176 * 3. This Copyright notice may not be removed or altered from
177 * any source or altered source distribution.
179 * The Contributing Authors and Group 42, Inc. specifically permit, without
180 * fee, and encourage the use of this source code as a component to
181 * supporting the PNG file format in commercial products. If you use this
182 * source code in a product, acknowledgment is not required but would be
187 * A "png_get_copyright" function is available, for convenient use in "about"
188 * boxes and the like:
190 * printf("%s",png_get_copyright(NULL));
192 * Also, the PNG logo (in PNG format, of course) is supplied in the
193 * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
197 * Libpng is OSI Certified Open Source Software. OSI Certified is a
198 * certification mark of the Open Source Initiative.
202 * The contributing authors would like to thank all those who helped
203 * with testing, bug fixes, and patience. This wouldn't have been
204 * possible without all of you.
206 * Thanks to Frank J. T. Wojcik for helping with the documentation.
210 * Y2K compliance in libpng:
211 * =========================
215 * Since the PNG Development group is an ad-hoc body, we can't make
216 * an official declaration.
218 * This is your unofficial assurance that libpng from version 0.71 and
219 * upward through 1.2.0 are Y2K compliant. It is my belief that earlier
220 * versions were also Y2K compliant.
222 * Libpng only has three year fields. One is a 2-byte unsigned integer
223 * that will hold years up to 65535. The other two hold the date in text
224 * format, and will hold years up to 9999.
227 * "png_uint_16 year" in png_time_struct.
230 * "png_charp time_buffer" in png_struct and
231 * "near_time_buffer", which is a local character string in png.c.
233 * There are seven time-related functions:
234 * png.c: png_convert_to_rfc_1123() in png.c
235 * (formerly png_convert_to_rfc_1152() in error)
236 * png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
237 * png_convert_from_time_t() in pngwrite.c
238 * png_get_tIME() in pngget.c
239 * png_handle_tIME() in pngrutil.c, called in pngread.c
240 * png_set_tIME() in pngset.c
241 * png_write_tIME() in pngwutil.c, called in pngwrite.c
243 * All handle dates properly in a Y2K environment. The
244 * png_convert_from_time_t() function calls gmtime() to convert from system
245 * clock time, which returns (year - 1900), which we properly convert to
246 * the full 4-digit year. There is a possibility that applications using
247 * libpng are not passing 4-digit years into the png_convert_to_rfc_1123()
248 * function, or that they are incorrectly passing only a 2-digit year
249 * instead of "year - 1900" into the png_convert_from_struct_tm() function,
250 * but this is not under our control. The libpng documentation has always
251 * stated that it works with 4-digit years, and the APIs have been
252 * documented as such.
254 * The tIME chunk itself is also Y2K compliant. It uses a 2-byte unsigned
255 * integer to hold the year, and can hold years as large as 65535.
257 * zlib, upon which libpng depends, is also Y2K compliant. It contains
258 * no date-related code.
260 * Glenn Randers-Pehrson
262 * PNG Development Group
268 /* This is not the place to learn how to use libpng. The file libpng.txt
269 * describes how to use libpng, and the file example.c summarizes it
270 * with some code on which to build. This file is useful for looking
271 * at the actual function definitions and structure components.
274 /* Version information for png.h - this should match the version in png.c */
275 #define PNG_LIBPNG_VER_STRING "1.2.0"
277 #define PNG_LIBPNG_VER_SONUM 3
278 #define PNG_LIBPNG_VER_DLLNUM %DLLNUM%
280 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
281 #define PNG_LIBPNG_VER_MAJOR 1
282 #define PNG_LIBPNG_VER_MINOR 2
283 #define PNG_LIBPNG_VER_RELEASE 0
284 /* This should match the numeric part of the final component of
285 * PNG_LIBPNG_VER_STRING, omitting any leading zero: */
287 #define PNG_LIBPNG_VER_BUILD 0
289 #define PNG_LIBPNG_BUILD_ALPHA 1
290 #define PNG_LIBPNG_BUILD_BETA 2
291 #define PNG_LIBPNG_BUILD_RC 3
292 #define PNG_LIBPNG_BUILD_STABLE 4
293 #define PNG_LIBPNG_BUILD_TYPEMASK 7
294 #define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with STABLE only */
295 #define PNG_LIBPNG_BUILD_TYPE 4
297 /* Careful here. At one time, Guy wanted to use 082, but that would be octal.
298 * We must not include leading zeros.
299 * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only
300 * version 1.0.0 was mis-numbered 100 instead of 10000). From
301 * version 1.0.1 it's xxyyzz, where x=major, y=minor, z=release */
302 #define PNG_LIBPNG_VER 10200 /* 1.2.0 */
304 #ifndef PNG_VERSION_INFO_ONLY
306 /* include the compression library's header */
309 /* include all user configurable info, including optional assembler routines */
312 /* Inhibit C++ name-mangling for libpng functions but not for system calls. */
315 #endif /* __cplusplus */
317 /* This file is arranged in several sections. The first section contains
318 * structure and type definitions. The second section contains the external
319 * library functions, while the third has the internal library functions,
320 * which applications aren't expected to use directly.
323 /* variables declared in png.c - only it needs to define PNG_NO_EXTERN */
324 #if !defined(PNG_NO_EXTERN) || defined(PNG_ALWAYS_EXTERN)
325 /* Version information for C files, stored in png.c. This had better match
328 #ifdef PNG_USE_GLOBAL_ARRAYS
329 PNG_EXPORT_VAR (const char) png_libpng_ver[18];
330 /* need room for 99.99.99beta99z*/
332 #define png_libpng_ver png_get_header_ver(NULL)
335 #ifdef PNG_USE_GLOBAL_ARRAYS
336 /* This was removed in version 1.0.5c */
337 /* Structures to facilitate easy interlacing. See png.c for more details */
338 PNG_EXPORT_VAR (const int FARDATA) png_pass_start[7];
339 PNG_EXPORT_VAR (const int FARDATA) png_pass_inc[7];
340 PNG_EXPORT_VAR (const int FARDATA) png_pass_ystart[7];
341 PNG_EXPORT_VAR (const int FARDATA) png_pass_yinc[7];
342 PNG_EXPORT_VAR (const int FARDATA) png_pass_mask[7];
343 PNG_EXPORT_VAR (const int FARDATA) png_pass_dsp_mask[7];
344 #ifdef PNG_HAVE_ASSEMBLER_COMBINE_ROW
345 PNG_EXPORT_VAR (const int FARDATA) png_pass_width[7];
347 /* This isn't currently used. If you need it, see png.c for more details.
348 PNG_EXPORT_VAR (const int FARDATA) png_pass_height[7];
352 #endif /* PNG_NO_EXTERN */
354 /* Three color definitions. The order of the red, green, and blue, (and the
355 * exact size) is not important, although the size of the fields need to
356 * be png_byte or png_uint_16 (as defined below).
358 typedef struct png_color_struct
364 typedef png_color FAR * png_colorp;
365 typedef png_color FAR * FAR * png_colorpp;
367 typedef struct png_color_16_struct
369 png_byte index; /* used for palette files */
370 png_uint_16 red; /* for use in red green blue files */
373 png_uint_16 gray; /* for use in grayscale files */
375 typedef png_color_16 FAR * png_color_16p;
376 typedef png_color_16 FAR * FAR * png_color_16pp;
378 typedef struct png_color_8_struct
380 png_byte red; /* for use in red green blue files */
383 png_byte gray; /* for use in grayscale files */
384 png_byte alpha; /* for alpha channel files */
386 typedef png_color_8 FAR * png_color_8p;
387 typedef png_color_8 FAR * FAR * png_color_8pp;
390 * The following two structures are used for the in-core representation
393 typedef struct png_sPLT_entry_struct
399 png_uint_16 frequency;
401 typedef png_sPLT_entry FAR * png_sPLT_entryp;
402 typedef png_sPLT_entry FAR * FAR * png_sPLT_entrypp;
404 /* When the depth of the sPLT palette is 8 bits, the color and alpha samples
405 * occupy the LSB of their respective members, and the MSB of each member
406 * is zero-filled. The frequency member always occupies the full 16 bits.
409 typedef struct png_sPLT_struct
411 png_charp name; /* palette name */
412 png_byte depth; /* depth of palette samples */
413 png_sPLT_entryp entries; /* palette entries */
414 png_int_32 nentries; /* number of palette entries */
416 typedef png_sPLT_t FAR * png_sPLT_tp;
417 typedef png_sPLT_t FAR * FAR * png_sPLT_tpp;
419 #ifdef PNG_TEXT_SUPPORTED
420 /* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,
421 * and whether that contents is compressed or not. The "key" field
422 * points to a regular zero-terminated C string. The "text", "lang", and
423 * "lang_key" fields can be regular C strings, empty strings, or NULL pointers.
424 * However, the * structure returned by png_get_text() will always contain
425 * regular zero-terminated C strings (possibly empty), never NULL pointers,
426 * so they can be safely used in printf() and other string-handling functions.
428 typedef struct png_text_struct
430 int compression; /* compression value:
435 png_charp key; /* keyword, 1-79 character description of "text" */
436 png_charp text; /* comment, may be an empty string (ie "")
438 png_size_t text_length; /* length of the text string */
439 #ifdef PNG_iTXt_SUPPORTED
440 png_size_t itxt_length; /* length of the itxt string */
441 png_charp lang; /* language code, 0-79 characters
443 png_charp lang_key; /* keyword translated UTF-8 string, 0 or more
444 chars or a NULL pointer */
447 typedef png_text FAR * png_textp;
448 typedef png_text FAR * FAR * png_textpp;
451 /* Supported compression types for text in PNG files (tEXt, and zTXt).
452 * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */
453 #define PNG_TEXT_COMPRESSION_NONE_WR -3
454 #define PNG_TEXT_COMPRESSION_zTXt_WR -2
455 #define PNG_TEXT_COMPRESSION_NONE -1
456 #define PNG_TEXT_COMPRESSION_zTXt 0
457 #define PNG_ITXT_COMPRESSION_NONE 1
458 #define PNG_ITXT_COMPRESSION_zTXt 2
459 #define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */
461 /* png_time is a way to hold the time in an machine independent way.
462 * Two conversions are provided, both from time_t and struct tm. There
463 * is no portable way to convert to either of these structures, as far
464 * as I know. If you know of a portable way, send it to me. As a side
465 * note - PNG has always been Year 2000 compliant!
467 typedef struct png_time_struct
469 png_uint_16 year; /* full year, as in, 1995 */
470 png_byte month; /* month of year, 1 - 12 */
471 png_byte day; /* day of month, 1 - 31 */
472 png_byte hour; /* hour of day, 0 - 23 */
473 png_byte minute; /* minute of hour, 0 - 59 */
474 png_byte second; /* second of minute, 0 - 60 (for leap seconds) */
476 typedef png_time FAR * png_timep;
477 typedef png_time FAR * FAR * png_timepp;
479 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
480 /* png_unknown_chunk is a structure to hold queued chunks for which there is
481 * no specific support. The idea is that we can use this to queue
482 * up private chunks for output even though the library doesn't actually
483 * know about their semantics.
485 typedef struct png_unknown_chunk_t
491 /* libpng-using applications should NOT directly modify this byte. */
492 png_byte location; /* mode of operation at read time */
495 typedef png_unknown_chunk FAR * png_unknown_chunkp;
496 typedef png_unknown_chunk FAR * FAR * png_unknown_chunkpp;
499 /* png_info is a structure that holds the information in a PNG file so
500 * that the application can find out the characteristics of the image.
501 * If you are reading the file, this structure will tell you what is
502 * in the PNG file. If you are writing the file, fill in the information
503 * you want to put into the PNG file, then call png_write_info().
504 * The names chosen should be very close to the PNG specification, so
505 * consult that document for information about the meaning of each field.
507 * With libpng < 0.95, it was only possible to directly set and read the
508 * the values in the png_info_struct, which meant that the contents and
509 * order of the values had to remain fixed. With libpng 0.95 and later,
510 * however, there are now functions that abstract the contents of
511 * png_info_struct from the application, so this makes it easier to use
512 * libpng with dynamic libraries, and even makes it possible to use
513 * libraries that don't have all of the libpng ancillary chunk-handing
516 * In any case, the order of the parameters in png_info_struct should NOT
517 * be changed for as long as possible to keep compatibility with applications
518 * that use the old direct-access method with png_info_struct.
520 * The following members may have allocated storage attached that should be
521 * cleaned up before the structure is discarded: palette, trans, text,
522 * pcal_purpose, pcal_units, pcal_params, hist, iccp_name, iccp_profile,
523 * splt_palettes, scal_unit, row_pointers, and unknowns. By default, these
524 * are automatically freed when the info structure is deallocated, if they were
525 * allocated internally by libpng. This behavior can be changed by means
526 * of the png_data_freer() function.
528 * More allocation details: all the chunk-reading functions that
529 * change these members go through the corresponding png_set_*
530 * functions. A function to clear these members is available: see
531 * png_free_data(). The png_set_* functions do not depend on being
532 * able to point info structure members to any of the storage they are
533 * passed (they make their own copies), EXCEPT that the png_set_text
534 * functions use the same storage passed to them in the text_ptr or
535 * itxt_ptr structure argument, and the png_set_rows and png_set_unknowns
536 * functions do not make their own copies.
538 typedef struct png_info_struct
540 /* the following are necessary for every PNG file */
541 png_uint_32 width; /* width of image in pixels (from IHDR) */
542 png_uint_32 height; /* height of image in pixels (from IHDR) */
543 png_uint_32 valid; /* valid chunk data (see PNG_INFO_ below) */
544 png_uint_32 rowbytes; /* bytes needed to hold an untransformed row */
545 png_colorp palette; /* array of color values (valid & PNG_INFO_PLTE) */
546 png_uint_16 num_palette; /* number of color entries in "palette" (PLTE) */
547 png_uint_16 num_trans; /* number of transparent palette color (tRNS) */
548 png_byte bit_depth; /* 1, 2, 4, 8, or 16 bits/channel (from IHDR) */
549 png_byte color_type; /* see PNG_COLOR_TYPE_ below (from IHDR) */
550 /* The following three should have been named *_method not *_type */
551 png_byte compression_type; /* must be PNG_COMPRESSION_TYPE_BASE (IHDR) */
552 png_byte filter_type; /* must be PNG_FILTER_TYPE_BASE (from IHDR) */
553 png_byte interlace_type; /* One of PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
555 /* The following is informational only on read, and not used on writes. */
556 png_byte channels; /* number of data channels per pixel (1, 2, 3, 4)*/
557 png_byte pixel_depth; /* number of bits per pixel */
558 png_byte spare_byte; /* to align the data, and for future use */
559 png_byte signature[8]; /* magic bytes read by libpng from start of file */
561 /* The rest of the data is optional. If you are reading, check the
562 * valid field to see if the information in these are valid. If you
563 * are writing, set the valid field to those chunks you want written,
564 * and initialize the appropriate fields below.
567 #if defined(PNG_gAMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
568 /* The gAMA chunk describes the gamma characteristics of the system
569 * on which the image was created, normally in the range [1.0, 2.5].
570 * Data is valid if (valid & PNG_INFO_gAMA) is non-zero.
572 float gamma; /* gamma value of image, if (valid & PNG_INFO_gAMA) */
575 #if defined(PNG_sRGB_SUPPORTED)
577 /* Data valid if (valid & PNG_INFO_sRGB) non-zero. */
578 png_byte srgb_intent; /* sRGB rendering intent [0, 1, 2, or 3] */
581 #if defined(PNG_TEXT_SUPPORTED)
582 /* The tEXt, and zTXt chunks contain human-readable textual data in
583 * uncompressed, compressed, and optionally compressed forms, respectively.
584 * The data in "text" is an array of pointers to uncompressed,
585 * null-terminated C strings. Each chunk has a keyword that describes the
586 * textual data contained in that chunk. Keywords are not required to be
587 * unique, and the text string may be empty. Any number of text chunks may
590 int num_text; /* number of comments read/to write */
591 int max_text; /* current size of text array */
592 png_textp text; /* array of comments read/to write */
593 #endif /* PNG_TEXT_SUPPORTED */
595 #if defined(PNG_tIME_SUPPORTED)
596 /* The tIME chunk holds the last time the displayed image data was
597 * modified. See the png_time struct for the contents of this struct.
602 #if defined(PNG_sBIT_SUPPORTED)
603 /* The sBIT chunk specifies the number of significant high-order bits
604 * in the pixel data. Values are in the range [1, bit_depth], and are
605 * only specified for the channels in the pixel data. The contents of
606 * the low-order bits is not specified. Data is valid if
607 * (valid & PNG_INFO_sBIT) is non-zero.
609 png_color_8 sig_bit; /* significant bits in color channels */
612 #if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_EXPAND_SUPPORTED) || \
613 defined(PNG_READ_BACKGROUND_SUPPORTED)
614 /* The tRNS chunk supplies transparency data for paletted images and
615 * other image types that don't need a full alpha channel. There are
616 * "num_trans" transparency values for a paletted image, stored in the
617 * same order as the palette colors, starting from index 0. Values
618 * for the data are in the range [0, 255], ranging from fully transparent
619 * to fully opaque, respectively. For non-paletted images, there is a
620 * single color specified that should be treated as fully transparent.
621 * Data is valid if (valid & PNG_INFO_tRNS) is non-zero.
623 png_bytep trans; /* transparent values for paletted image */
624 png_color_16 trans_values; /* transparent color for non-palette image */
627 #if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
628 /* The bKGD chunk gives the suggested image background color if the
629 * display program does not have its own background color and the image
630 * is needs to composited onto a background before display. The colors
631 * in "background" are normally in the same color space/depth as the
632 * pixel data. Data is valid if (valid & PNG_INFO_bKGD) is non-zero.
634 png_color_16 background;
637 #if defined(PNG_oFFs_SUPPORTED)
638 /* The oFFs chunk gives the offset in "offset_unit_type" units rightwards
639 * and downwards from the top-left corner of the display, page, or other
640 * application-specific co-ordinate space. See the PNG_OFFSET_ defines
641 * below for the unit types. Valid if (valid & PNG_INFO_oFFs) non-zero.
643 png_int_32 x_offset; /* x offset on page */
644 png_int_32 y_offset; /* y offset on page */
645 png_byte offset_unit_type; /* offset units type */
648 #if defined(PNG_pHYs_SUPPORTED)
649 /* The pHYs chunk gives the physical pixel density of the image for
650 * display or printing in "phys_unit_type" units (see PNG_RESOLUTION_
651 * defines below). Data is valid if (valid & PNG_INFO_pHYs) is non-zero.
653 png_uint_32 x_pixels_per_unit; /* horizontal pixel density */
654 png_uint_32 y_pixels_per_unit; /* vertical pixel density */
655 png_byte phys_unit_type; /* resolution type (see PNG_RESOLUTION_ below) */
658 #if defined(PNG_hIST_SUPPORTED)
659 /* The hIST chunk contains the relative frequency or importance of the
660 * various palette entries, so that a viewer can intelligently select a
661 * reduced-color palette, if required. Data is an array of "num_palette"
662 * values in the range [0,65535]. Data valid if (valid & PNG_INFO_hIST)
668 #ifdef PNG_cHRM_SUPPORTED
669 /* The cHRM chunk describes the CIE color characteristics of the monitor
670 * on which the PNG was created. This data allows the viewer to do gamut
671 * mapping of the input image to ensure that the viewer sees the same
672 * colors in the image as the creator. Values are in the range
673 * [0.0, 0.8]. Data valid if (valid & PNG_INFO_cHRM) non-zero.
675 #ifdef PNG_FLOATING_POINT_SUPPORTED
687 #if defined(PNG_pCAL_SUPPORTED)
688 /* The pCAL chunk describes a transformation between the stored pixel
689 * values and original physical data values used to create the image.
690 * The integer range [0, 2^bit_depth - 1] maps to the floating-point
691 * range given by [pcal_X0, pcal_X1], and are further transformed by a
692 * (possibly non-linear) transformation function given by "pcal_type"
693 * and "pcal_params" into "pcal_units". Please see the PNG_EQUATION_
694 * defines below, and the PNG-Group's PNG extensions document for a
695 * complete description of the transformations and how they should be
696 * implemented, and for a description of the ASCII parameter strings.
697 * Data values are valid if (valid & PNG_INFO_pCAL) non-zero.
699 png_charp pcal_purpose; /* pCAL chunk description string */
700 png_int_32 pcal_X0; /* minimum value */
701 png_int_32 pcal_X1; /* maximum value */
702 png_charp pcal_units; /* Latin-1 string giving physical units */
703 png_charpp pcal_params; /* ASCII strings containing parameter values */
704 png_byte pcal_type; /* equation type (see PNG_EQUATION_ below) */
705 png_byte pcal_nparams; /* number of parameters given in pcal_params */
708 /* New members added in libpng-1.0.6 */
709 #ifdef PNG_FREE_ME_SUPPORTED
710 png_uint_32 free_me; /* flags items libpng is responsible for freeing */
713 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
714 /* storage for unknown chunks that the library doesn't recognize. */
715 png_unknown_chunkp unknown_chunks;
716 png_size_t unknown_chunks_num;
719 #if defined(PNG_iCCP_SUPPORTED)
720 /* iCCP chunk data. */
721 png_charp iccp_name; /* profile name */
722 png_charp iccp_profile; /* International Color Consortium profile data */
723 /* Note to maintainer: should be png_bytep */
724 png_uint_32 iccp_proflen; /* ICC profile data length */
725 png_byte iccp_compression; /* Always zero */
728 #if defined(PNG_sPLT_SUPPORTED)
729 /* data on sPLT chunks (there may be more than one). */
730 png_sPLT_tp splt_palettes;
731 png_uint_32 splt_palettes_num;
734 #if defined(PNG_sCAL_SUPPORTED)
735 /* The sCAL chunk describes the actual physical dimensions of the
736 * subject matter of the graphic. The chunk contains a unit specification
737 * a byte value, and two ASCII strings representing floating-point
738 * values. The values are width and height corresponsing to one pixel
739 * in the image. This external representation is converted to double
740 * here. Data values are valid if (valid & PNG_INFO_sCAL) is non-zero.
742 png_byte scal_unit; /* unit of physical scale */
743 #ifdef PNG_FLOATING_POINT_SUPPORTED
744 double scal_pixel_width; /* width of one pixel */
745 double scal_pixel_height; /* height of one pixel */
747 #ifdef PNG_FIXED_POINT_SUPPORTED
748 png_charp scal_s_width; /* string containing height */
749 png_charp scal_s_height; /* string containing width */
753 #if defined(PNG_INFO_IMAGE_SUPPORTED)
754 /* Memory has been allocated if (valid & PNG_ALLOCATED_INFO_ROWS) non-zero */
755 /* Data valid if (valid & PNG_INFO_IDAT) non-zero */
756 png_bytepp row_pointers; /* the image bits */
759 #if defined(PNG_FIXED_POINT_SUPPORTED) && defined(PNG_gAMA_SUPPORTED)
760 png_fixed_point int_gamma; /* gamma of image, if (valid & PNG_INFO_gAMA) */
763 #if defined(PNG_cHRM_SUPPORTED) && defined(PNG_FIXED_POINT_SUPPORTED)
764 png_fixed_point int_x_white;
765 png_fixed_point int_y_white;
766 png_fixed_point int_x_red;
767 png_fixed_point int_y_red;
768 png_fixed_point int_x_green;
769 png_fixed_point int_y_green;
770 png_fixed_point int_x_blue;
771 png_fixed_point int_y_blue;
776 typedef png_info FAR * png_infop;
777 typedef png_info FAR * FAR * png_infopp;
779 /* Maximum positive integer used in PNG is (2^31)-1 */
780 #define PNG_MAX_UINT ((png_uint_32)0x7fffffffL)
782 /* These describe the color_type field in png_info. */
783 /* color type masks */
784 #define PNG_COLOR_MASK_PALETTE 1
785 #define PNG_COLOR_MASK_COLOR 2
786 #define PNG_COLOR_MASK_ALPHA 4
788 /* color types. Note that not all combinations are legal */
789 #define PNG_COLOR_TYPE_GRAY 0
790 #define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
791 #define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR)
792 #define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
793 #define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
795 #define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA
796 #define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA
798 /* This is for compression type. PNG 1.0-1.2 only define the single type. */
799 #define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */
800 #define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE
802 /* This is for filter type. PNG 1.0-1.2 only define the single type. */
803 #define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */
804 #define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */
805 #define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE
807 /* These are for the interlacing type. These values should NOT be changed. */
808 #define PNG_INTERLACE_NONE 0 /* Non-interlaced image */
809 #define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */
810 #define PNG_INTERLACE_LAST 2 /* Not a valid value */
812 /* These are for the oFFs chunk. These values should NOT be changed. */
813 #define PNG_OFFSET_PIXEL 0 /* Offset in pixels */
814 #define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */
815 #define PNG_OFFSET_LAST 2 /* Not a valid value */
817 /* These are for the pCAL chunk. These values should NOT be changed. */
818 #define PNG_EQUATION_LINEAR 0 /* Linear transformation */
819 #define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */
820 #define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */
821 #define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */
822 #define PNG_EQUATION_LAST 4 /* Not a valid value */
824 /* These are for the sCAL chunk. These values should NOT be changed. */
825 #define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */
826 #define PNG_SCALE_METER 1 /* meters per pixel */
827 #define PNG_SCALE_RADIAN 2 /* radians per pixel */
828 #define PNG_SCALE_LAST 3 /* Not a valid value */
830 /* These are for the pHYs chunk. These values should NOT be changed. */
831 #define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */
832 #define PNG_RESOLUTION_METER 1 /* pixels/meter */
833 #define PNG_RESOLUTION_LAST 2 /* Not a valid value */
835 /* These are for the sRGB chunk. These values should NOT be changed. */
836 #define PNG_sRGB_INTENT_PERCEPTUAL 0
837 #define PNG_sRGB_INTENT_RELATIVE 1
838 #define PNG_sRGB_INTENT_SATURATION 2
839 #define PNG_sRGB_INTENT_ABSOLUTE 3
840 #define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */
842 /* This is for text chunks */
843 #define PNG_KEYWORD_MAX_LENGTH 79
845 /* Maximum number of entries in PLTE/sPLT/tRNS arrays */
846 #define PNG_MAX_PALETTE_LENGTH 256
848 /* These determine if an ancillary chunk's data has been successfully read
849 * from the PNG header, or if the application has filled in the corresponding
850 * data in the info_struct to be written into the output file. The values
851 * of the PNG_INFO_<chunk> defines should NOT be changed.
853 #define PNG_INFO_gAMA 0x0001
854 #define PNG_INFO_sBIT 0x0002
855 #define PNG_INFO_cHRM 0x0004
856 #define PNG_INFO_PLTE 0x0008
857 #define PNG_INFO_tRNS 0x0010
858 #define PNG_INFO_bKGD 0x0020
859 #define PNG_INFO_hIST 0x0040
860 #define PNG_INFO_pHYs 0x0080
861 #define PNG_INFO_oFFs 0x0100
862 #define PNG_INFO_tIME 0x0200
863 #define PNG_INFO_pCAL 0x0400
864 #define PNG_INFO_sRGB 0x0800 /* GR-P, 0.96a */
865 #define PNG_INFO_iCCP 0x1000 /* ESR, 1.0.6 */
866 #define PNG_INFO_sPLT 0x2000 /* ESR, 1.0.6 */
867 #define PNG_INFO_sCAL 0x4000 /* ESR, 1.0.6 */
868 #define PNG_INFO_IDAT 0x8000L /* ESR, 1.0.6 */
870 /* This is used for the transformation routines, as some of them
871 * change these values for the row. It also should enable using
872 * the routines for other purposes.
874 typedef struct png_row_info_struct
876 png_uint_32 width; /* width of row */
877 png_uint_32 rowbytes; /* number of bytes in row */
878 png_byte color_type; /* color type of row */
879 png_byte bit_depth; /* bit depth of row */
880 png_byte channels; /* number of channels (1, 2, 3, or 4) */
881 png_byte pixel_depth; /* bits per pixel (depth * channels) */
884 typedef png_row_info FAR * png_row_infop;
885 typedef png_row_info FAR * FAR * png_row_infopp;
887 /* These are the function types for the I/O functions and for the functions
888 * that allow the user to override the default I/O functions with his or her
889 * own. The png_error_ptr type should match that of user-supplied warning
890 * and error functions, while the png_rw_ptr type should match that of the
891 * user read/write data functions.
893 typedef struct png_struct_def png_struct;
894 typedef png_struct FAR * png_structp;
896 typedef void (PNGAPI *png_error_ptr) PNGARG((png_structp, png_const_charp));
897 typedef void (PNGAPI *png_rw_ptr) PNGARG((png_structp, png_bytep, png_size_t));
898 typedef void (PNGAPI *png_flush_ptr) PNGARG((png_structp));
899 typedef void (PNGAPI *png_read_status_ptr) PNGARG((png_structp, png_uint_32,
901 typedef void (PNGAPI *png_write_status_ptr) PNGARG((png_structp, png_uint_32,
904 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
905 typedef void (PNGAPI *png_progressive_info_ptr) PNGARG((png_structp, png_infop));
906 typedef void (PNGAPI *png_progressive_end_ptr) PNGARG((png_structp, png_infop));
907 typedef void (PNGAPI *png_progressive_row_ptr) PNGARG((png_structp, png_bytep,
911 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
912 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
913 defined(PNG_LEGACY_SUPPORTED)
914 typedef void (PNGAPI *png_user_transform_ptr) PNGARG((png_structp,
915 png_row_infop, png_bytep));
918 #if defined(PNG_USER_CHUNKS_SUPPORTED)
919 typedef int (PNGAPI *png_user_chunk_ptr) PNGARG((png_structp, png_unknown_chunkp));
921 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
922 typedef void (PNGAPI *png_unknown_chunk_ptr) PNGARG((png_structp));
925 /* Transform masks for the high-level interface */
926 #define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */
927 #define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */
928 #define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */
929 #define PNG_TRANSFORM_PACKING 0x0004 /* read and write */
930 #define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */
931 #define PNG_TRANSFORM_EXPAND 0x0010 /* read only */
932 #define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */
933 #define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */
934 #define PNG_TRANSFORM_BGR 0x0080 /* read and write */
935 #define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */
936 #define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */
937 #define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */
938 #define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* WRITE only */
940 /* Flags for MNG supported features */
941 #define PNG_FLAG_MNG_EMPTY_PLTE 0x01
942 #define PNG_FLAG_MNG_FILTER_64 0x04
943 #define PNG_ALL_MNG_FEATURES 0x05
945 typedef png_voidp (*png_malloc_ptr) PNGARG((png_structp, png_size_t));
946 typedef void (*png_free_ptr) PNGARG((png_structp, png_voidp));
948 /* The structure that holds the information to read and write PNG files.
949 * The only people who need to care about what is inside of this are the
950 * people who will be modifying the library for their own special needs.
951 * It should NOT be accessed directly by an application, except to store
955 struct png_struct_def
957 #ifdef PNG_SETJMP_SUPPORTED
958 jmp_buf jmpbuf; /* used in png_error */
960 png_error_ptr error_fn; /* function for printing errors and aborting */
961 png_error_ptr warning_fn; /* function for printing warnings */
962 png_voidp error_ptr; /* user supplied struct for error functions */
963 png_rw_ptr write_data_fn; /* function for writing output data */
964 png_rw_ptr read_data_fn; /* function for reading input data */
965 png_voidp io_ptr; /* ptr to application struct for I/O functions*/
967 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
968 png_user_transform_ptr read_user_transform_fn; /* user read transform */
971 #if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
972 png_user_transform_ptr write_user_transform_fn; /* user write transform */
975 /* These were added in libpng-1.0.2 */
976 #if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
977 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
978 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
979 png_voidp user_transform_ptr; /* user supplied struct for user transform */
980 png_byte user_transform_depth; /* bit depth of user transformed pixels */
981 png_byte user_transform_channels; /* channels in user transformed pixels */
985 png_uint_32 mode; /* tells us where we are in the PNG file */
986 png_uint_32 flags; /* flags indicating various things to libpng */
987 png_uint_32 transformations; /* which transformations to perform */
989 z_stream zstream; /* pointer to decompression structure (below) */
990 png_bytep zbuf; /* buffer for zlib */
991 png_size_t zbuf_size; /* size of zbuf */
992 int zlib_level; /* holds zlib compression level */
993 int zlib_method; /* holds zlib compression method */
994 int zlib_window_bits; /* holds zlib compression window bits */
995 int zlib_mem_level; /* holds zlib compression memory level */
996 int zlib_strategy; /* holds zlib compression strategy */
998 png_uint_32 width; /* width of image in pixels */
999 png_uint_32 height; /* height of image in pixels */
1000 png_uint_32 num_rows; /* number of rows in current pass */
1001 png_uint_32 usr_width; /* width of row at start of write */
1002 png_uint_32 rowbytes; /* size of row in bytes */
1003 png_uint_32 irowbytes; /* size of current interlaced row in bytes */
1004 png_uint_32 iwidth; /* width of current interlaced row in pixels */
1005 png_uint_32 row_number; /* current row in interlace pass */
1006 png_bytep prev_row; /* buffer to save previous (unfiltered) row */
1007 png_bytep row_buf; /* buffer to save current (unfiltered) row */
1008 png_bytep sub_row; /* buffer to save "sub" row when filtering */
1009 png_bytep up_row; /* buffer to save "up" row when filtering */
1010 png_bytep avg_row; /* buffer to save "avg" row when filtering */
1011 png_bytep paeth_row; /* buffer to save "Paeth" row when filtering */
1012 png_row_info row_info; /* used for transformation routines */
1014 png_uint_32 idat_size; /* current IDAT size for read */
1015 png_uint_32 crc; /* current chunk CRC value */
1016 png_colorp palette; /* palette from the input file */
1017 png_uint_16 num_palette; /* number of color entries in palette */
1018 png_uint_16 num_trans; /* number of transparency values */
1019 png_byte chunk_name[5]; /* null-terminated name of current chunk */
1020 png_byte compression; /* file compression type (always 0) */
1021 png_byte filter; /* file filter type (always 0) */
1022 png_byte interlaced; /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
1023 png_byte pass; /* current interlace pass (0 - 6) */
1024 png_byte do_filter; /* row filter flags (see PNG_FILTER_ below ) */
1025 png_byte color_type; /* color type of file */
1026 png_byte bit_depth; /* bit depth of file */
1027 png_byte usr_bit_depth; /* bit depth of users row */
1028 png_byte pixel_depth; /* number of bits per pixel */
1029 png_byte channels; /* number of channels in file */
1030 png_byte usr_channels; /* channels at start of write */
1031 png_byte sig_bytes; /* magic bytes read/written from start of file */
1033 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
1034 #ifdef PNG_LEGACY_SUPPORTED
1035 png_byte filler; /* filler byte for pixel expansion */
1037 png_uint_16 filler; /* filler bytes for pixel expansion */
1041 #if defined(PNG_bKGD_SUPPORTED)
1042 png_byte background_gamma_type;
1043 # ifdef PNG_FLOATING_POINT_SUPPORTED
1044 float background_gamma;
1046 png_color_16 background; /* background color in screen gamma space */
1047 # if defined(PNG_READ_GAMMA_SUPPORTED)
1048 png_color_16 background_1; /* background normalized to gamma 1.0 */
1049 # endif /* PNG_READ_GAMMA && PNG_bKGD_SUPPORTED */
1050 #endif /* PNG_bKGD_SUPPORTED */
1052 #if defined(PNG_WRITE_FLUSH_SUPPORTED)
1053 png_flush_ptr output_flush_fn;/* Function for flushing output */
1054 png_uint_32 flush_dist; /* how many rows apart to flush, 0 - no flush */
1055 png_uint_32 flush_rows; /* number of rows written since last flush */
1058 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1059 int gamma_shift; /* number of "insignificant" bits 16-bit gamma */
1060 #ifdef PNG_FLOATING_POINT_SUPPORTED
1061 float gamma; /* file gamma value */
1062 float screen_gamma; /* screen gamma value (display_exponent) */
1066 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1067 png_bytep gamma_table; /* gamma table for 8-bit depth files */
1068 png_bytep gamma_from_1; /* converts from 1.0 to screen */
1069 png_bytep gamma_to_1; /* converts from file to 1.0 */
1070 png_uint_16pp gamma_16_table; /* gamma table for 16-bit depth files */
1071 png_uint_16pp gamma_16_from_1; /* converts from 1.0 to screen */
1072 png_uint_16pp gamma_16_to_1; /* converts from file to 1.0 */
1075 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_sBIT_SUPPORTED)
1076 png_color_8 sig_bit; /* significant bits in each available channel */
1079 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
1080 png_color_8 shift; /* shift for significant bit tranformation */
1083 #if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \
1084 || defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1085 png_bytep trans; /* transparency values for paletted files */
1086 png_color_16 trans_values; /* transparency values for non-paletted files */
1089 png_read_status_ptr read_row_fn; /* called after each row is decoded */
1090 png_write_status_ptr write_row_fn; /* called after each row is encoded */
1091 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1092 png_progressive_info_ptr info_fn; /* called after header data fully read */
1093 png_progressive_row_ptr row_fn; /* called after each prog. row is decoded */
1094 png_progressive_end_ptr end_fn; /* called after image is complete */
1095 png_bytep save_buffer_ptr; /* current location in save_buffer */
1096 png_bytep save_buffer; /* buffer for previously read data */
1097 png_bytep current_buffer_ptr; /* current location in current_buffer */
1098 png_bytep current_buffer; /* buffer for recently used data */
1099 png_uint_32 push_length; /* size of current input chunk */
1100 png_uint_32 skip_length; /* bytes to skip in input data */
1101 png_size_t save_buffer_size; /* amount of data now in save_buffer */
1102 png_size_t save_buffer_max; /* total size of save_buffer */
1103 png_size_t buffer_size; /* total amount of available input data */
1104 png_size_t current_buffer_size; /* amount of data now in current_buffer */
1105 int process_mode; /* what push library is currently doing */
1106 int cur_palette; /* current push library palette index */
1108 # if defined(PNG_TEXT_SUPPORTED)
1109 png_size_t current_text_size; /* current size of text input data */
1110 png_size_t current_text_left; /* how much text left to read in input */
1111 png_charp current_text; /* current text chunk buffer */
1112 png_charp current_text_ptr; /* current location in current_text */
1113 # endif /* PNG_PROGRESSIVE_READ_SUPPORTED && PNG_TEXT_SUPPORTED */
1115 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
1117 #if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
1118 /* for the Borland special 64K segment handler */
1119 png_bytepp offset_table_ptr;
1120 png_bytep offset_table;
1121 png_uint_16 offset_table_number;
1122 png_uint_16 offset_table_count;
1123 png_uint_16 offset_table_count_free;
1126 #if defined(PNG_READ_DITHER_SUPPORTED)
1127 png_bytep palette_lookup; /* lookup table for dithering */
1128 png_bytep dither_index; /* index translation for palette files */
1131 #if defined(PNG_READ_DITHER_SUPPORTED) || defined(PNG_hIST_SUPPORTED)
1132 png_uint_16p hist; /* histogram */
1135 #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
1136 png_byte heuristic_method; /* heuristic for row filter selection */
1137 png_byte num_prev_filters; /* number of weights for previous rows */
1138 png_bytep prev_filters; /* filter type(s) of previous row(s) */
1139 png_uint_16p filter_weights; /* weight(s) for previous line(s) */
1140 png_uint_16p inv_filter_weights; /* 1/weight(s) for previous line(s) */
1141 png_uint_16p filter_costs; /* relative filter calculation cost */
1142 png_uint_16p inv_filter_costs; /* 1/relative filter calculation cost */
1145 #if defined(PNG_TIME_RFC1123_SUPPORTED)
1146 png_charp time_buffer; /* String to hold RFC 1123 time text */
1149 /* New members added in libpng-1.0.6 */
1151 #ifdef PNG_FREE_ME_SUPPORTED
1152 png_uint_32 free_me; /* flags items libpng is responsible for freeing */
1155 #if defined(PNG_USER_CHUNKS_SUPPORTED)
1156 png_voidp user_chunk_ptr;
1157 png_user_chunk_ptr read_user_chunk_fn; /* user read chunk handler */
1160 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
1162 png_bytep chunk_list;
1165 /* New members added in libpng-1.0.3 */
1166 #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
1167 png_byte rgb_to_gray_status;
1168 /* These were changed from png_byte in libpng-1.0.6 */
1169 png_uint_16 rgb_to_gray_red_coeff;
1170 png_uint_16 rgb_to_gray_green_coeff;
1171 png_uint_16 rgb_to_gray_blue_coeff;
1174 /* New member added in libpng-1.0.4 (renamed in 1.0.9) */
1175 #if defined(PNG_MNG_FEATURES_SUPPORTED) || \
1176 defined(PNG_READ_EMPTY_PLTE_SUPPORTED) || \
1177 defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
1178 /* changed from png_byte to png_uint_32 at version 1.2.0 */
1179 png_uint_32 mng_features_permitted;
1182 /* New member added in libpng-1.0.7 */
1183 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1184 png_fixed_point int_gamma;
1187 /* New member added in libpng-1.0.9, ifdef'ed out in 1.0.12, enabled in 1.2.0 */
1188 #if defined(PNG_MNG_FEATURES_SUPPORTED)
1189 png_byte filter_type;
1192 #if defined(PNG_DEBUG) && defined(PNG_USE_PNGGCCRD)
1193 /* New member added in libpng-1.0.10, ifdef'ed out in 1.2.0 */
1194 png_uint_32 row_buf_size;
1197 /* New members added in libpng-1.2.0 */
1198 #if defined(PNG_ASSEMBLER_CODE_SUPPORTED)
1199 png_byte mmx_bitdepth_threshold;
1200 png_uint_32 mmx_rowbytes_threshold;
1201 png_uint_32 asm_flags;
1204 /* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */
1205 #ifdef PNG_USER_MEM_SUPPORTED
1206 png_voidp mem_ptr; /* user supplied struct for mem functions */
1207 png_malloc_ptr malloc_fn; /* function for allocating memory */
1208 png_free_ptr free_fn; /* function for freeing memory */
1211 png_bytep big_row_buf; /* buffer to save current (unfiltered) row */
1216 /* This prevents a compiler error in png_get_copyright() in png.c if png.c
1217 and png.h are both at version 1.2.0
1219 typedef png_structp version_1_2_0;
1221 typedef png_struct FAR * FAR * png_structpp;
1223 /* Here are the function definitions most commonly used. This is not
1224 * the place to find out how to use libpng. See libpng.txt for the
1225 * full explanation, see example.c for the summary. This just provides
1226 * a simple one line description of the use of each function.
1229 /* Returns the version number of the library */
1230 extern PNG_EXPORT(png_uint_32,png_access_version_number) PNGARG((void));
1232 /* Tell lib we have already handled the first <num_bytes> magic bytes.
1233 * Handling more than 8 bytes from the beginning of the file is an error.
1235 extern PNG_EXPORT(void,png_set_sig_bytes) PNGARG((png_structp png_ptr,
1238 /* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
1239 * PNG file. Returns zero if the supplied bytes match the 8-byte PNG
1240 * signature, and non-zero otherwise. Having num_to_check == 0 or
1241 * start > 7 will always fail (ie return non-zero).
1243 extern PNG_EXPORT(int,png_sig_cmp) PNGARG((png_bytep sig, png_size_t start,
1244 png_size_t num_to_check));
1246 /* Simple signature checking function. This is the same as calling
1247 * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n).
1249 extern PNG_EXPORT(int,png_check_sig) PNGARG((png_bytep sig, int num));
1251 /* Allocate and initialize png_ptr struct for reading, and any other memory. */
1252 extern PNG_EXPORT(png_structp,png_create_read_struct)
1253 PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1254 png_error_ptr error_fn, png_error_ptr warn_fn));
1256 /* Allocate and initialize png_ptr struct for writing, and any other memory */
1257 extern PNG_EXPORT(png_structp,png_create_write_struct)
1258 PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1259 png_error_ptr error_fn, png_error_ptr warn_fn));
1261 extern PNG_EXPORT(png_uint_32,png_get_compression_buffer_size)
1262 PNGARG((png_structp png_ptr));
1264 extern PNG_EXPORT(void,png_set_compression_buffer_size)
1265 PNGARG((png_structp png_ptr, png_uint_32 size));
1267 /* Reset the compression stream */
1268 extern PNG_EXPORT(int,png_reset_zstream) PNGARG((png_structp png_ptr));
1270 /* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */
1271 #ifdef PNG_USER_MEM_SUPPORTED
1272 extern PNG_EXPORT(png_structp,png_create_read_struct_2)
1273 PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1274 png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
1275 png_malloc_ptr malloc_fn, png_free_ptr free_fn));
1276 extern PNG_EXPORT(png_structp,png_create_write_struct_2)
1277 PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1278 png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
1279 png_malloc_ptr malloc_fn, png_free_ptr free_fn));
1282 /* Write a PNG chunk - size, type, (optional) data, CRC. */
1283 extern PNG_EXPORT(void,png_write_chunk) PNGARG((png_structp png_ptr,
1284 png_bytep chunk_name, png_bytep data, png_size_t length));
1286 /* Write the start of a PNG chunk - length and chunk name. */
1287 extern PNG_EXPORT(void,png_write_chunk_start) PNGARG((png_structp png_ptr,
1288 png_bytep chunk_name, png_uint_32 length));
1290 /* Write the data of a PNG chunk started with png_write_chunk_start(). */
1291 extern PNG_EXPORT(void,png_write_chunk_data) PNGARG((png_structp png_ptr,
1292 png_bytep data, png_size_t length));
1294 /* Finish a chunk started with png_write_chunk_start() (includes CRC). */
1295 extern PNG_EXPORT(void,png_write_chunk_end) PNGARG((png_structp png_ptr));
1297 /* Allocate and initialize the info structure */
1298 extern PNG_EXPORT(png_infop,png_create_info_struct)
1299 PNGARG((png_structp png_ptr));
1301 /* Initialize the info structure (old interface - DEPRECATED) */
1302 extern PNG_EXPORT(void,png_info_init) PNGARG((png_infop info_ptr));
1303 #define png_info_init(info_ptr) png_info_init_3(&info_ptr, sizeof(png_info));
1304 extern PNG_EXPORT(void,png_info_init_3) PNGARG((png_infopp info_ptr,
1305 png_size_t png_info_struct_size));
1307 /* Writes all the PNG information before the image. */
1308 extern PNG_EXPORT(void,png_write_info_before_PLTE) PNGARG((png_structp png_ptr,
1309 png_infop info_ptr));
1310 extern PNG_EXPORT(void,png_write_info) PNGARG((png_structp png_ptr,
1311 png_infop info_ptr));
1313 /* read the information before the actual image data. */
1314 extern PNG_EXPORT(void,png_read_info) PNGARG((png_structp png_ptr,
1315 png_infop info_ptr));
1317 #if defined(PNG_TIME_RFC1123_SUPPORTED)
1318 extern PNG_EXPORT(png_charp,png_convert_to_rfc1123)
1319 PNGARG((png_structp png_ptr, png_timep ptime));
1322 #if !defined(_WIN32_WCE)
1323 /* "time.h" functions are not supported on WindowsCE */
1324 #if defined(PNG_WRITE_tIME_SUPPORTED)
1325 /* convert from a struct tm to png_time */
1326 extern PNG_EXPORT(void,png_convert_from_struct_tm) PNGARG((png_timep ptime,
1327 struct tm FAR * ttime));
1329 /* convert from time_t to png_time. Uses gmtime() */
1330 extern PNG_EXPORT(void,png_convert_from_time_t) PNGARG((png_timep ptime,
1332 #endif /* PNG_WRITE_tIME_SUPPORTED */
1333 #endif /* _WIN32_WCE */
1335 #if defined(PNG_READ_EXPAND_SUPPORTED)
1336 /* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
1337 extern PNG_EXPORT(void,png_set_expand) PNGARG((png_structp png_ptr));
1338 extern PNG_EXPORT(void,png_set_gray_1_2_4_to_8) PNGARG((png_structp png_ptr));
1339 extern PNG_EXPORT(void,png_set_palette_to_rgb) PNGARG((png_structp png_ptr));
1340 extern PNG_EXPORT(void,png_set_tRNS_to_alpha) PNGARG((png_structp png_ptr));
1343 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
1344 /* Use blue, green, red order for pixels. */
1345 extern PNG_EXPORT(void,png_set_bgr) PNGARG((png_structp png_ptr));
1348 #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
1349 /* Expand the grayscale to 24-bit RGB if necessary. */
1350 extern PNG_EXPORT(void,png_set_gray_to_rgb) PNGARG((png_structp png_ptr));
1353 #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
1354 /* Reduce RGB to grayscale. */
1355 #ifdef PNG_FLOATING_POINT_SUPPORTED
1356 extern PNG_EXPORT(void,png_set_rgb_to_gray) PNGARG((png_structp png_ptr,
1357 int error_action, double red, double green ));
1359 extern PNG_EXPORT(void,png_set_rgb_to_gray_fixed) PNGARG((png_structp png_ptr,
1360 int error_action, png_fixed_point red, png_fixed_point green ));
1361 extern PNG_EXPORT(png_byte,png_get_rgb_to_gray_status) PNGARG((png_structp
1365 extern PNG_EXPORT(void,png_build_grayscale_palette) PNGARG((int bit_depth,
1366 png_colorp palette));
1368 #if defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
1369 extern PNG_EXPORT(void,png_set_strip_alpha) PNGARG((png_structp png_ptr));
1372 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
1373 defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
1374 extern PNG_EXPORT(void,png_set_swap_alpha) PNGARG((png_structp png_ptr));
1377 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
1378 defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
1379 extern PNG_EXPORT(void,png_set_invert_alpha) PNGARG((png_structp png_ptr));
1382 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
1383 /* Add a filler byte to 24-bit RGB images. */
1384 extern PNG_EXPORT(void,png_set_filler) PNGARG((png_structp png_ptr,
1385 png_uint_32 filler, int flags));
1386 /* The values of the PNG_FILLER_ defines should NOT be changed */
1387 #define PNG_FILLER_BEFORE 0
1388 #define PNG_FILLER_AFTER 1
1389 #endif /* PNG_READ_FILLER_SUPPORTED || PNG_WRITE_FILLER_SUPPORTED */
1391 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
1392 /* Swap bytes in 16-bit depth files. */
1393 extern PNG_EXPORT(void,png_set_swap) PNGARG((png_structp png_ptr));
1396 #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
1397 /* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
1398 extern PNG_EXPORT(void,png_set_packing) PNGARG((png_structp png_ptr));
1401 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1402 /* Swap packing order of pixels in bytes. */
1403 extern PNG_EXPORT(void,png_set_packswap) PNGARG((png_structp png_ptr));
1406 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
1407 /* Converts files to legal bit depths. */
1408 extern PNG_EXPORT(void,png_set_shift) PNGARG((png_structp png_ptr,
1409 png_color_8p true_bits));
1412 #if defined(PNG_READ_INTERLACING_SUPPORTED) || \
1413 defined(PNG_WRITE_INTERLACING_SUPPORTED)
1414 /* Have the code handle the interlacing. Returns the number of passes. */
1415 extern PNG_EXPORT(int,png_set_interlace_handling) PNGARG((png_structp png_ptr));
1418 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
1419 /* Invert monochrome files */
1420 extern PNG_EXPORT(void,png_set_invert_mono) PNGARG((png_structp png_ptr));
1423 #if defined(PNG_READ_BACKGROUND_SUPPORTED)
1424 /* Handle alpha and tRNS by replacing with a background color. */
1425 #ifdef PNG_FLOATING_POINT_SUPPORTED
1426 extern PNG_EXPORT(void,png_set_background) PNGARG((png_structp png_ptr,
1427 png_color_16p background_color, int background_gamma_code,
1428 int need_expand, double background_gamma));
1430 #define PNG_BACKGROUND_GAMMA_UNKNOWN 0
1431 #define PNG_BACKGROUND_GAMMA_SCREEN 1
1432 #define PNG_BACKGROUND_GAMMA_FILE 2
1433 #define PNG_BACKGROUND_GAMMA_UNIQUE 3
1436 #if defined(PNG_READ_16_TO_8_SUPPORTED)
1437 /* strip the second byte of information from a 16-bit depth file. */
1438 extern PNG_EXPORT(void,png_set_strip_16) PNGARG((png_structp png_ptr));
1441 #if defined(PNG_READ_DITHER_SUPPORTED)
1442 /* Turn on dithering, and reduce the palette to the number of colors available. */
1443 extern PNG_EXPORT(void,png_set_dither) PNGARG((png_structp png_ptr,
1444 png_colorp palette, int num_palette, int maximum_colors,
1445 png_uint_16p histogram, int full_dither));
1448 #if defined(PNG_READ_GAMMA_SUPPORTED)
1449 /* Handle gamma correction. Screen_gamma=(display_exponent) */
1450 #ifdef PNG_FLOATING_POINT_SUPPORTED
1451 extern PNG_EXPORT(void,png_set_gamma) PNGARG((png_structp png_ptr,
1452 double screen_gamma, double default_file_gamma));
1456 #if defined(PNG_READ_EMPTY_PLTE_SUPPORTED) || \
1457 defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
1458 /* Permit or disallow empty PLTE (0: not permitted, 1: permitted) */
1459 /* Deprecated and will be removed. Use png_permit_mng_features() instead. */
1460 extern PNG_EXPORT(void,png_permit_empty_plte) PNGARG((png_structp png_ptr,
1461 int empty_plte_permitted));
1464 #if defined(PNG_WRITE_FLUSH_SUPPORTED)
1465 /* Set how many lines between output flushes - 0 for no flushing */
1466 extern PNG_EXPORT(void,png_set_flush) PNGARG((png_structp png_ptr, int nrows));
1467 /* Flush the current PNG output buffer */
1468 extern PNG_EXPORT(void,png_write_flush) PNGARG((png_structp png_ptr));
1471 /* optional update palette with requested transformations */
1472 extern PNG_EXPORT(void,png_start_read_image) PNGARG((png_structp png_ptr));
1474 /* optional call to update the users info structure */
1475 extern PNG_EXPORT(void,png_read_update_info) PNGARG((png_structp png_ptr,
1476 png_infop info_ptr));
1478 /* read a one or more rows of image data.*/
1479 extern PNG_EXPORT(void,png_read_rows) PNGARG((png_structp png_ptr,
1480 png_bytepp row, png_bytepp display_row, png_uint_32 num_rows));
1482 /* read a row of data.*/
1483 extern PNG_EXPORT(void,png_read_row) PNGARG((png_structp png_ptr,
1485 png_bytep display_row));
1487 /* read the whole image into memory at once. */
1488 extern PNG_EXPORT(void,png_read_image) PNGARG((png_structp png_ptr,
1491 /* write a row of image data */
1492 extern PNG_EXPORT(void,png_write_row) PNGARG((png_structp png_ptr,
1495 /* write a few rows of image data */
1496 extern PNG_EXPORT(void,png_write_rows) PNGARG((png_structp png_ptr,
1497 png_bytepp row, png_uint_32 num_rows));
1499 /* write the image data */
1500 extern PNG_EXPORT(void,png_write_image) PNGARG((png_structp png_ptr,
1503 /* writes the end of the PNG file. */
1504 extern PNG_EXPORT(void,png_write_end) PNGARG((png_structp png_ptr,
1505 png_infop info_ptr));
1507 /* read the end of the PNG file. */
1508 extern PNG_EXPORT(void,png_read_end) PNGARG((png_structp png_ptr,
1509 png_infop info_ptr));
1511 /* free any memory associated with the png_info_struct */
1512 extern PNG_EXPORT(void,png_destroy_info_struct) PNGARG((png_structp png_ptr,
1513 png_infopp info_ptr_ptr));
1515 /* free any memory associated with the png_struct and the png_info_structs */
1516 extern PNG_EXPORT(void,png_destroy_read_struct) PNGARG((png_structpp
1517 png_ptr_ptr, png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr));
1519 /* free all memory used by the read (old method - NOT DLL EXPORTED) */
1520 extern void png_read_destroy PNGARG((png_structp png_ptr, png_infop info_ptr,
1521 png_infop end_info_ptr));
1523 /* free any memory associated with the png_struct and the png_info_structs */
1524 extern PNG_EXPORT(void,png_destroy_write_struct)
1525 PNGARG((png_structpp png_ptr_ptr, png_infopp info_ptr_ptr));
1527 /* free any memory used in info_ptr struct (old method - NOT DLL EXPORTED) */
1528 extern void png_write_destroy_info PNGARG((png_infop info_ptr));
1530 /* free any memory used in png_ptr struct (old method - NOT DLL EXPORTED) */
1531 extern void png_write_destroy PNGARG((png_structp png_ptr));
1533 /* set the libpng method of handling chunk CRC errors */
1534 extern PNG_EXPORT(void,png_set_crc_action) PNGARG((png_structp png_ptr,
1535 int crit_action, int ancil_action));
1537 /* Values for png_set_crc_action() to say how to handle CRC errors in
1538 * ancillary and critical chunks, and whether to use the data contained
1539 * therein. Note that it is impossible to "discard" data in a critical
1540 * chunk. For versions prior to 0.90, the action was always error/quit,
1541 * whereas in version 0.90 and later, the action for CRC errors in ancillary
1542 * chunks is warn/discard. These values should NOT be changed.
1544 * value action:critical action:ancillary
1546 #define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */
1547 #define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */
1548 #define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */
1549 #define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */
1550 #define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */
1551 #define PNG_CRC_NO_CHANGE 5 /* use current value use current value */
1553 /* These functions give the user control over the scan-line filtering in
1554 * libpng and the compression methods used by zlib. These functions are
1555 * mainly useful for testing, as the defaults should work with most users.
1556 * Those users who are tight on memory or want faster performance at the
1557 * expense of compression can modify them. See the compression library
1558 * header file (zlib.h) for an explination of the compression functions.
1561 /* set the filtering method(s) used by libpng. Currently, the only valid
1562 * value for "method" is 0.
1564 extern PNG_EXPORT(void,png_set_filter) PNGARG((png_structp png_ptr, int method,
1567 /* Flags for png_set_filter() to say which filters to use. The flags
1568 * are chosen so that they don't conflict with real filter types
1569 * below, in case they are supplied instead of the #defined constants.
1570 * These values should NOT be changed.
1572 #define PNG_NO_FILTERS 0x00
1573 #define PNG_FILTER_NONE 0x08
1574 #define PNG_FILTER_SUB 0x10
1575 #define PNG_FILTER_UP 0x20
1576 #define PNG_FILTER_AVG 0x40
1577 #define PNG_FILTER_PAETH 0x80
1578 #define PNG_ALL_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP | \
1579 PNG_FILTER_AVG | PNG_FILTER_PAETH)
1581 /* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
1582 * These defines should NOT be changed.
1584 #define PNG_FILTER_VALUE_NONE 0
1585 #define PNG_FILTER_VALUE_SUB 1
1586 #define PNG_FILTER_VALUE_UP 2
1587 #define PNG_FILTER_VALUE_AVG 3
1588 #define PNG_FILTER_VALUE_PAETH 4
1589 #define PNG_FILTER_VALUE_LAST 5
1591 #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) /* EXPERIMENTAL */
1592 /* The "heuristic_method" is given by one of the PNG_FILTER_HEURISTIC_
1593 * defines, either the default (minimum-sum-of-absolute-differences), or
1594 * the experimental method (weighted-minimum-sum-of-absolute-differences).
1596 * Weights are factors >= 1.0, indicating how important it is to keep the
1597 * filter type consistent between rows. Larger numbers mean the current
1598 * filter is that many times as likely to be the same as the "num_weights"
1599 * previous filters. This is cumulative for each previous row with a weight.
1600 * There needs to be "num_weights" values in "filter_weights", or it can be
1601 * NULL if the weights aren't being specified. Weights have no influence on
1602 * the selection of the first row filter. Well chosen weights can (in theory)
1603 * improve the compression for a given image.
1605 * Costs are factors >= 1.0 indicating the relative decoding costs of a
1606 * filter type. Higher costs indicate more decoding expense, and are
1607 * therefore less likely to be selected over a filter with lower computational
1608 * costs. There needs to be a value in "filter_costs" for each valid filter
1609 * type (given by PNG_FILTER_VALUE_LAST), or it can be NULL if you aren't
1610 * setting the costs. Costs try to improve the speed of decompression without
1611 * unduly increasing the compressed image size.
1613 * A negative weight or cost indicates the default value is to be used, and
1614 * values in the range [0.0, 1.0) indicate the value is to remain unchanged.
1615 * The default values for both weights and costs are currently 1.0, but may
1616 * change if good general weighting/cost heuristics can be found. If both
1617 * the weights and costs are set to 1.0, this degenerates the WEIGHTED method
1618 * to the UNWEIGHTED method, but with added encoding time/computation.
1620 #ifdef PNG_FLOATING_POINT_SUPPORTED
1621 extern PNG_EXPORT(void,png_set_filter_heuristics) PNGARG((png_structp png_ptr,
1622 int heuristic_method, int num_weights, png_doublep filter_weights,
1623 png_doublep filter_costs));
1625 #endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
1627 /* Heuristic used for row filter selection. These defines should NOT be
1630 #define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */
1631 #define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */
1632 #define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */
1633 #define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */
1635 /* Set the library compression level. Currently, valid values range from
1636 * 0 - 9, corresponding directly to the zlib compression levels 0 - 9
1637 * (0 - no compression, 9 - "maximal" compression). Note that tests have
1638 * shown that zlib compression levels 3-6 usually perform as well as level 9
1639 * for PNG images, and do considerably fewer caclulations. In the future,
1640 * these values may not correspond directly to the zlib compression levels.
1642 extern PNG_EXPORT(void,png_set_compression_level) PNGARG((png_structp png_ptr,
1645 extern PNG_EXPORT(void,png_set_compression_mem_level)
1646 PNGARG((png_structp png_ptr, int mem_level));
1648 extern PNG_EXPORT(void,png_set_compression_strategy)
1649 PNGARG((png_structp png_ptr, int strategy));
1651 extern PNG_EXPORT(void,png_set_compression_window_bits)
1652 PNGARG((png_structp png_ptr, int window_bits));
1654 extern PNG_EXPORT(void,png_set_compression_method) PNGARG((png_structp png_ptr,
1657 /* These next functions are called for input/output, memory, and error
1658 * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c,
1659 * and call standard C I/O routines such as fread(), fwrite(), and
1660 * fprintf(). These functions can be made to use other I/O routines
1661 * at run time for those applications that need to handle I/O in a
1662 * different manner by calling png_set_???_fn(). See libpng.txt for
1666 #if !defined(PNG_NO_STDIO)
1667 /* Initialize the input/output for the PNG file to the default functions. */
1668 extern PNG_EXPORT(void,png_init_io) PNGARG((png_structp png_ptr, png_FILE_p fp));
1671 /* Replace the (error and abort), and warning functions with user
1672 * supplied functions. If no messages are to be printed you must still
1673 * write and use replacement functions. The replacement error_fn should
1674 * still do a longjmp to the last setjmp location if you are using this
1675 * method of error handling. If error_fn or warning_fn is NULL, the
1676 * default function will be used.
1679 extern PNG_EXPORT(void,png_set_error_fn) PNGARG((png_structp png_ptr,
1680 png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn));
1682 /* Return the user pointer associated with the error functions */
1683 extern PNG_EXPORT(png_voidp,png_get_error_ptr) PNGARG((png_structp png_ptr));
1685 /* Replace the default data output functions with a user supplied one(s).
1686 * If buffered output is not used, then output_flush_fn can be set to NULL.
1687 * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time
1688 * output_flush_fn will be ignored (and thus can be NULL).
1690 extern PNG_EXPORT(void,png_set_write_fn) PNGARG((png_structp png_ptr,
1691 png_voidp io_ptr, png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn));
1693 /* Replace the default data input function with a user supplied one. */
1694 extern PNG_EXPORT(void,png_set_read_fn) PNGARG((png_structp png_ptr,
1695 png_voidp io_ptr, png_rw_ptr read_data_fn));
1697 /* Return the user pointer associated with the I/O functions */
1698 extern PNG_EXPORT(png_voidp,png_get_io_ptr) PNGARG((png_structp png_ptr));
1700 extern PNG_EXPORT(void,png_set_read_status_fn) PNGARG((png_structp png_ptr,
1701 png_read_status_ptr read_row_fn));
1703 extern PNG_EXPORT(void,png_set_write_status_fn) PNGARG((png_structp png_ptr,
1704 png_write_status_ptr write_row_fn));
1706 #ifdef PNG_USER_MEM_SUPPORTED
1707 /* Replace the default memory allocation functions with user supplied one(s). */
1708 extern PNG_EXPORT(void,png_set_mem_fn) PNGARG((png_structp png_ptr,
1709 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn));
1710 /* Return the user pointer associated with the memory functions */
1711 extern PNG_EXPORT(png_voidp,png_get_mem_ptr) PNGARG((png_structp png_ptr));
1714 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
1715 defined(PNG_LEGACY_SUPPORTED)
1716 extern PNG_EXPORT(void,png_set_read_user_transform_fn) PNGARG((png_structp
1717 png_ptr, png_user_transform_ptr read_user_transform_fn));
1720 #if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
1721 defined(PNG_LEGACY_SUPPORTED)
1722 extern PNG_EXPORT(void,png_set_write_user_transform_fn) PNGARG((png_structp
1723 png_ptr, png_user_transform_ptr write_user_transform_fn));
1726 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
1727 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
1728 defined(PNG_LEGACY_SUPPORTED)
1729 extern PNG_EXPORT(void,png_set_user_transform_info) PNGARG((png_structp
1730 png_ptr, png_voidp user_transform_ptr, int user_transform_depth,
1731 int user_transform_channels));
1732 /* Return the user pointer associated with the user transform functions */
1733 extern PNG_EXPORT(png_voidp,png_get_user_transform_ptr)
1734 PNGARG((png_structp png_ptr));
1737 #ifdef PNG_USER_CHUNKS_SUPPORTED
1738 extern PNG_EXPORT(void,png_set_read_user_chunk_fn) PNGARG((png_structp png_ptr,
1739 png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));
1740 extern PNG_EXPORT(png_voidp,png_get_user_chunk_ptr) PNGARG((png_structp
1744 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1745 /* Sets the function callbacks for the push reader, and a pointer to a
1746 * user-defined structure available to the callback functions.
1748 extern PNG_EXPORT(void,png_set_progressive_read_fn) PNGARG((png_structp png_ptr,
1749 png_voidp progressive_ptr,
1750 png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
1751 png_progressive_end_ptr end_fn));
1753 /* returns the user pointer associated with the push read functions */
1754 extern PNG_EXPORT(png_voidp,png_get_progressive_ptr)
1755 PNGARG((png_structp png_ptr));
1757 /* function to be called when data becomes available */
1758 extern PNG_EXPORT(void,png_process_data) PNGARG((png_structp png_ptr,
1759 png_infop info_ptr, png_bytep buffer, png_size_t buffer_size));
1761 /* function that combines rows. Not very much different than the
1762 * png_combine_row() call. Is this even used?????
1764 extern PNG_EXPORT(void,png_progressive_combine_row) PNGARG((png_structp png_ptr,
1765 png_bytep old_row, png_bytep new_row));
1766 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
1768 extern PNG_EXPORT(png_voidp,png_malloc) PNGARG((png_structp png_ptr,
1771 /* frees a pointer allocated by png_malloc() */
1772 extern PNG_EXPORT(void,png_free) PNGARG((png_structp png_ptr, png_voidp ptr));
1774 /* Free data that was allocated internally */
1775 extern PNG_EXPORT(void,png_free_data) PNGARG((png_structp png_ptr,
1776 png_infop info_ptr, png_uint_32 free_me, int num));
1777 #ifdef PNG_FREE_ME_SUPPORTED
1778 /* Reassign responsibility for freeing existing data, whether allocated
1779 * by libpng or by the application */
1780 extern PNG_EXPORT(void,png_data_freer) PNGARG((png_structp png_ptr,
1781 png_infop info_ptr, int freer, png_uint_32 mask));
1783 /* assignments for png_data_freer */
1784 #define PNG_DESTROY_WILL_FREE_DATA 1
1785 #define PNG_SET_WILL_FREE_DATA 1
1786 #define PNG_USER_WILL_FREE_DATA 2
1787 /* Flags for png_ptr->free_me and info_ptr->free_me */
1788 #define PNG_FREE_HIST 0x0008
1789 #define PNG_FREE_ICCP 0x0010
1790 #define PNG_FREE_SPLT 0x0020
1791 #define PNG_FREE_ROWS 0x0040
1792 #define PNG_FREE_PCAL 0x0080
1793 #define PNG_FREE_SCAL 0x0100
1794 #define PNG_FREE_UNKN 0x0200
1795 #define PNG_FREE_LIST 0x0400
1796 #define PNG_FREE_PLTE 0x1000
1797 #define PNG_FREE_TRNS 0x2000
1798 #define PNG_FREE_TEXT 0x4000
1799 #define PNG_FREE_ALL 0x7fff
1800 #define PNG_FREE_MUL 0x4220 /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */
1802 #ifdef PNG_USER_MEM_SUPPORTED
1803 extern PNG_EXPORT(png_voidp,png_malloc_default) PNGARG((png_structp png_ptr,
1805 extern PNG_EXPORT(void,png_free_default) PNGARG((png_structp png_ptr,
1809 extern PNG_EXPORT(png_voidp,png_memcpy_check) PNGARG((png_structp png_ptr,
1810 png_voidp s1, png_voidp s2, png_uint_32 size));
1812 extern PNG_EXPORT(png_voidp,png_memset_check) PNGARG((png_structp png_ptr,
1813 png_voidp s1, int value, png_uint_32 size));
1815 #if defined(USE_FAR_KEYWORD) /* memory model conversion function */
1816 extern void *png_far_to_near PNGARG((png_structp png_ptr,png_voidp ptr,
1818 #endif /* USE_FAR_KEYWORD */
1820 /* Fatal error in PNG image of libpng - can't continue */
1821 extern PNG_EXPORT(void,png_error) PNGARG((png_structp png_ptr,
1822 png_const_charp error));
1824 /* The same, but the chunk name is prepended to the error string. */
1825 extern PNG_EXPORT(void,png_chunk_error) PNGARG((png_structp png_ptr,
1826 png_const_charp error));
1828 /* Non-fatal error in libpng. Can continue, but may have a problem. */
1829 extern PNG_EXPORT(void,png_warning) PNGARG((png_structp png_ptr,
1830 png_const_charp message));
1832 /* Non-fatal error in libpng, chunk name is prepended to message. */
1833 extern PNG_EXPORT(void,png_chunk_warning) PNGARG((png_structp png_ptr,
1834 png_const_charp message));
1836 /* The png_set_<chunk> functions are for storing values in the png_info_struct.
1837 * Similarly, the png_get_<chunk> calls are used to read values from the
1838 * png_info_struct, either storing the parameters in the passed variables, or
1839 * setting pointers into the png_info_struct where the data is stored. The
1840 * png_get_<chunk> functions return a non-zero value if the data was available
1841 * in info_ptr, or return zero and do not change any of the parameters if the
1842 * data was not available.
1844 * These functions should be used instead of directly accessing png_info
1845 * to avoid problems with future changes in the size and internal layout of
1848 /* Returns "flag" if chunk data is valid in info_ptr. */
1849 extern PNG_EXPORT(png_uint_32,png_get_valid) PNGARG((png_structp png_ptr,
1850 png_infop info_ptr, png_uint_32 flag));
1852 /* Returns number of bytes needed to hold a transformed row. */
1853 extern PNG_EXPORT(png_uint_32,png_get_rowbytes) PNGARG((png_structp png_ptr,
1854 png_infop info_ptr));
1856 #if defined(PNG_INFO_IMAGE_SUPPORTED)
1857 /* Returns row_pointers, which is an array of pointers to scanlines that was
1858 returned from png_read_png(). */
1859 extern PNG_EXPORT(png_bytepp,png_get_rows) PNGARG((png_structp png_ptr,
1860 png_infop info_ptr));
1861 /* Set row_pointers, which is an array of pointers to scanlines for use
1862 by png_write_png(). */
1863 extern PNG_EXPORT(void,png_set_rows) PNGARG((png_structp png_ptr,
1864 png_infop info_ptr, png_bytepp row_pointers));
1867 /* Returns number of color channels in image. */
1868 extern PNG_EXPORT(png_byte,png_get_channels) PNGARG((png_structp png_ptr,
1869 png_infop info_ptr));
1871 #ifdef PNG_EASY_ACCESS_SUPPORTED
1872 /* Returns image width in pixels. */
1873 extern PNG_EXPORT(png_uint_32, png_get_image_width) PNGARG((png_structp
1874 png_ptr, png_infop info_ptr));
1876 /* Returns image height in pixels. */
1877 extern PNG_EXPORT(png_uint_32, png_get_image_height) PNGARG((png_structp
1878 png_ptr, png_infop info_ptr));
1880 /* Returns image bit_depth. */
1881 extern PNG_EXPORT(png_byte, png_get_bit_depth) PNGARG((png_structp
1882 png_ptr, png_infop info_ptr));
1884 /* Returns image color_type. */
1885 extern PNG_EXPORT(png_byte, png_get_color_type) PNGARG((png_structp
1886 png_ptr, png_infop info_ptr));
1888 /* Returns image filter_type. */
1889 extern PNG_EXPORT(png_byte, png_get_filter_type) PNGARG((png_structp
1890 png_ptr, png_infop info_ptr));
1892 /* Returns image interlace_type. */
1893 extern PNG_EXPORT(png_byte, png_get_interlace_type) PNGARG((png_structp
1894 png_ptr, png_infop info_ptr));
1896 /* Returns image compression_type. */
1897 extern PNG_EXPORT(png_byte, png_get_compression_type) PNGARG((png_structp
1898 png_ptr, png_infop info_ptr));
1900 /* Returns image resolution in pixels per meter, from pHYs chunk data. */
1901 extern PNG_EXPORT(png_uint_32, png_get_pixels_per_meter) PNGARG((png_structp
1902 png_ptr, png_infop info_ptr));
1903 extern PNG_EXPORT(png_uint_32, png_get_x_pixels_per_meter) PNGARG((png_structp
1904 png_ptr, png_infop info_ptr));
1905 extern PNG_EXPORT(png_uint_32, png_get_y_pixels_per_meter) PNGARG((png_structp
1906 png_ptr, png_infop info_ptr));
1908 /* Returns pixel aspect ratio, computed from pHYs chunk data. */
1909 #ifdef PNG_FLOATING_POINT_SUPPORTED
1910 extern PNG_EXPORT(float, png_get_pixel_aspect_ratio) PNGARG((png_structp
1911 png_ptr, png_infop info_ptr));
1914 /* Returns image x, y offset in pixels or microns, from oFFs chunk data. */
1915 extern PNG_EXPORT(png_int_32, png_get_x_offset_pixels) PNGARG((png_structp
1916 png_ptr, png_infop info_ptr));
1917 extern PNG_EXPORT(png_int_32, png_get_y_offset_pixels) PNGARG((png_structp
1918 png_ptr, png_infop info_ptr));
1919 extern PNG_EXPORT(png_int_32, png_get_x_offset_microns) PNGARG((png_structp
1920 png_ptr, png_infop info_ptr));
1921 extern PNG_EXPORT(png_int_32, png_get_y_offset_microns) PNGARG((png_structp
1922 png_ptr, png_infop info_ptr));
1924 #endif /* PNG_EASY_ACCESS_SUPPORTED */
1926 /* Returns pointer to signature string read from PNG header */
1927 extern PNG_EXPORT(png_bytep,png_get_signature) PNGARG((png_structp png_ptr,
1928 png_infop info_ptr));
1930 #if defined(PNG_bKGD_SUPPORTED)
1931 extern PNG_EXPORT(png_uint_32,png_get_bKGD) PNGARG((png_structp png_ptr,
1932 png_infop info_ptr, png_color_16p *background));
1935 #if defined(PNG_bKGD_SUPPORTED)
1936 extern PNG_EXPORT(void,png_set_bKGD) PNGARG((png_structp png_ptr,
1937 png_infop info_ptr, png_color_16p background));
1940 #if defined(PNG_cHRM_SUPPORTED)
1941 #ifdef PNG_FLOATING_POINT_SUPPORTED
1942 extern PNG_EXPORT(png_uint_32,png_get_cHRM) PNGARG((png_structp png_ptr,
1943 png_infop info_ptr, double *white_x, double *white_y, double *red_x,
1944 double *red_y, double *green_x, double *green_y, double *blue_x,
1947 #ifdef PNG_FIXED_POINT_SUPPORTED
1948 extern PNG_EXPORT(png_uint_32,png_get_cHRM_fixed) PNGARG((png_structp png_ptr,
1949 png_infop info_ptr, png_fixed_point *int_white_x, png_fixed_point
1950 *int_white_y, png_fixed_point *int_red_x, png_fixed_point *int_red_y,
1951 png_fixed_point *int_green_x, png_fixed_point *int_green_y, png_fixed_point
1952 *int_blue_x, png_fixed_point *int_blue_y));
1956 #if defined(PNG_cHRM_SUPPORTED)
1957 #ifdef PNG_FLOATING_POINT_SUPPORTED
1958 extern PNG_EXPORT(void,png_set_cHRM) PNGARG((png_structp png_ptr,
1959 png_infop info_ptr, double white_x, double white_y, double red_x,
1960 double red_y, double green_x, double green_y, double blue_x, double blue_y));
1962 #ifdef PNG_FIXED_POINT_SUPPORTED
1963 extern PNG_EXPORT(void,png_set_cHRM_fixed) PNGARG((png_structp png_ptr,
1964 png_infop info_ptr, png_fixed_point int_white_x, png_fixed_point int_white_y,
1965 png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
1966 int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
1967 png_fixed_point int_blue_y));
1971 #if defined(PNG_gAMA_SUPPORTED)
1972 #ifdef PNG_FLOATING_POINT_SUPPORTED
1973 extern PNG_EXPORT(png_uint_32,png_get_gAMA) PNGARG((png_structp png_ptr,
1974 png_infop info_ptr, double *file_gamma));
1976 extern PNG_EXPORT(png_uint_32,png_get_gAMA_fixed) PNGARG((png_structp png_ptr,
1977 png_infop info_ptr, png_fixed_point *int_file_gamma));
1980 #if defined(PNG_gAMA_SUPPORTED)
1981 #ifdef PNG_FLOATING_POINT_SUPPORTED
1982 extern PNG_EXPORT(void,png_set_gAMA) PNGARG((png_structp png_ptr,
1983 png_infop info_ptr, double file_gamma));
1985 extern PNG_EXPORT(void,png_set_gAMA_fixed) PNGARG((png_structp png_ptr,
1986 png_infop info_ptr, png_fixed_point int_file_gamma));
1989 #if defined(PNG_hIST_SUPPORTED)
1990 extern PNG_EXPORT(png_uint_32,png_get_hIST) PNGARG((png_structp png_ptr,
1991 png_infop info_ptr, png_uint_16p *hist));
1994 #if defined(PNG_hIST_SUPPORTED)
1995 extern PNG_EXPORT(void,png_set_hIST) PNGARG((png_structp png_ptr,
1996 png_infop info_ptr, png_uint_16p hist));
1999 extern PNG_EXPORT(png_uint_32,png_get_IHDR) PNGARG((png_structp png_ptr,
2000 png_infop info_ptr, png_uint_32 *width, png_uint_32 *height,
2001 int *bit_depth, int *color_type, int *interlace_method,
2002 int *compression_method, int *filter_method));
2004 extern PNG_EXPORT(void,png_set_IHDR) PNGARG((png_structp png_ptr,
2005 png_infop info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth,
2006 int color_type, int interlace_method, int compression_method,
2007 int filter_method));
2009 #if defined(PNG_oFFs_SUPPORTED)
2010 extern PNG_EXPORT(png_uint_32,png_get_oFFs) PNGARG((png_structp png_ptr,
2011 png_infop info_ptr, png_int_32 *offset_x, png_int_32 *offset_y,
2015 #if defined(PNG_oFFs_SUPPORTED)
2016 extern PNG_EXPORT(void,png_set_oFFs) PNGARG((png_structp png_ptr,
2017 png_infop info_ptr, png_int_32 offset_x, png_int_32 offset_y,
2021 #if defined(PNG_pCAL_SUPPORTED)
2022 extern PNG_EXPORT(png_uint_32,png_get_pCAL) PNGARG((png_structp png_ptr,
2023 png_infop info_ptr, png_charp *purpose, png_int_32 *X0, png_int_32 *X1,
2024 int *type, int *nparams, png_charp *units, png_charpp *params));
2027 #if defined(PNG_pCAL_SUPPORTED)
2028 extern PNG_EXPORT(void,png_set_pCAL) PNGARG((png_structp png_ptr,
2029 png_infop info_ptr, png_charp purpose, png_int_32 X0, png_int_32 X1,
2030 int type, int nparams, png_charp units, png_charpp params));
2033 #if defined(PNG_pHYs_SUPPORTED)
2034 extern PNG_EXPORT(png_uint_32,png_get_pHYs) PNGARG((png_structp png_ptr,
2035 png_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type));
2038 #if defined(PNG_pHYs_SUPPORTED)
2039 extern PNG_EXPORT(void,png_set_pHYs) PNGARG((png_structp png_ptr,
2040 png_infop info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type));
2043 extern PNG_EXPORT(png_uint_32,png_get_PLTE) PNGARG((png_structp png_ptr,
2044 png_infop info_ptr, png_colorp *palette, int *num_palette));
2046 extern PNG_EXPORT(void,png_set_PLTE) PNGARG((png_structp png_ptr,
2047 png_infop info_ptr, png_colorp palette, int num_palette));
2049 #if defined(PNG_sBIT_SUPPORTED)
2050 extern PNG_EXPORT(png_uint_32,png_get_sBIT) PNGARG((png_structp png_ptr,
2051 png_infop info_ptr, png_color_8p *sig_bit));
2054 #if defined(PNG_sBIT_SUPPORTED)
2055 extern PNG_EXPORT(void,png_set_sBIT) PNGARG((png_structp png_ptr,
2056 png_infop info_ptr, png_color_8p sig_bit));
2059 #if defined(PNG_sRGB_SUPPORTED)
2060 extern PNG_EXPORT(png_uint_32,png_get_sRGB) PNGARG((png_structp png_ptr,
2061 png_infop info_ptr, int *intent));
2064 #if defined(PNG_sRGB_SUPPORTED)
2065 extern PNG_EXPORT(void,png_set_sRGB) PNGARG((png_structp png_ptr,
2066 png_infop info_ptr, int intent));
2067 extern PNG_EXPORT(void,png_set_sRGB_gAMA_and_cHRM) PNGARG((png_structp png_ptr,
2068 png_infop info_ptr, int intent));
2071 #if defined(PNG_iCCP_SUPPORTED)
2072 extern PNG_EXPORT(png_uint_32,png_get_iCCP) PNGARG((png_structp png_ptr,
2073 png_infop info_ptr, png_charpp name, int *compression_type,
2074 png_charpp profile, png_uint_32 *proflen));
2075 /* Note to maintainer: profile should be png_bytepp */
2078 #if defined(PNG_iCCP_SUPPORTED)
2079 extern PNG_EXPORT(void,png_set_iCCP) PNGARG((png_structp png_ptr,
2080 png_infop info_ptr, png_charp name, int compression_type,
2081 png_charp profile, png_uint_32 proflen));
2082 /* Note to maintainer: profile should be png_bytep */
2085 #if defined(PNG_sPLT_SUPPORTED)
2086 extern PNG_EXPORT(png_uint_32,png_get_sPLT) PNGARG((png_structp png_ptr,
2087 png_infop info_ptr, png_sPLT_tpp entries));
2090 #if defined(PNG_sPLT_SUPPORTED)
2091 extern PNG_EXPORT(void,png_set_sPLT) PNGARG((png_structp png_ptr,
2092 png_infop info_ptr, png_sPLT_tp entries, int nentries));
2095 #if defined(PNG_TEXT_SUPPORTED)
2096 /* png_get_text also returns the number of text chunks in *num_text */
2097 extern PNG_EXPORT(png_uint_32,png_get_text) PNGARG((png_structp png_ptr,
2098 png_infop info_ptr, png_textp *text_ptr, int *num_text));
2102 * Note while png_set_text() will accept a structure whose text,
2103 * language, and translated keywords are NULL pointers, the structure
2104 * returned by png_get_text will always contain regular
2105 * zero-terminated C strings. They might be empty strings but
2106 * they will never be NULL pointers.
2109 #if defined(PNG_TEXT_SUPPORTED)
2110 extern PNG_EXPORT(void,png_set_text) PNGARG((png_structp png_ptr,
2111 png_infop info_ptr, png_textp text_ptr, int num_text));
2114 #if defined(PNG_tIME_SUPPORTED)
2115 extern PNG_EXPORT(png_uint_32,png_get_tIME) PNGARG((png_structp png_ptr,
2116 png_infop info_ptr, png_timep *mod_time));
2119 #if defined(PNG_tIME_SUPPORTED)
2120 extern PNG_EXPORT(void,png_set_tIME) PNGARG((png_structp png_ptr,
2121 png_infop info_ptr, png_timep mod_time));
2124 #if defined(PNG_tRNS_SUPPORTED)
2125 extern PNG_EXPORT(png_uint_32,png_get_tRNS) PNGARG((png_structp png_ptr,
2126 png_infop info_ptr, png_bytep *trans, int *num_trans,
2127 png_color_16p *trans_values));
2130 #if defined(PNG_tRNS_SUPPORTED)
2131 extern PNG_EXPORT(void,png_set_tRNS) PNGARG((png_structp png_ptr,
2132 png_infop info_ptr, png_bytep trans, int num_trans,
2133 png_color_16p trans_values));
2136 #if defined(PNG_tRNS_SUPPORTED)
2139 #if defined(PNG_sCAL_SUPPORTED)
2140 #ifdef PNG_FLOATING_POINT_SUPPORTED
2141 extern PNG_EXPORT(png_uint_32,png_get_sCAL) PNGARG((png_structp png_ptr,
2142 png_infop info_ptr, int *unit, double *width, double *height));
2144 #ifdef PNG_FIXED_POINT_SUPPORTED
2145 extern PNG_EXPORT(png_uint_32,png_get_sCAL_s) PNGARG((png_structp png_ptr,
2146 png_infop info_ptr, int *unit, png_charpp swidth, png_charpp sheight));
2149 #endif /* PNG_sCAL_SUPPORTED */
2151 #if defined(PNG_sCAL_SUPPORTED)
2152 #ifdef PNG_FLOATING_POINT_SUPPORTED
2153 extern PNG_EXPORT(void,png_set_sCAL) PNGARG((png_structp png_ptr,
2154 png_infop info_ptr, int unit, double width, double height));
2156 #ifdef PNG_FIXED_POINT_SUPPORTED
2157 extern PNG_EXPORT(void,png_set_sCAL_s) PNGARG((png_structp png_ptr,
2158 png_infop info_ptr, int unit, png_charp swidth, png_charp sheight));
2160 #endif /* PNG_sCAL_SUPPORTED || PNG_WRITE_sCAL_SUPPORTED */
2162 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
2163 /* provide a list of chunks and how they are to be handled, if the built-in
2164 handling or default unknown chunk handling is not desired. Any chunks not
2165 listed will be handled in the default manner. The IHDR and IEND chunks
2167 keep = 0: follow default behavour
2169 = 2: keep only if safe-to-copy
2170 = 3: keep even if unsafe-to-copy
2172 extern PNG_EXPORT(void, png_set_keep_unknown_chunks) PNGARG((png_structp
2173 png_ptr, int keep, png_bytep chunk_list, int num_chunks));
2174 extern PNG_EXPORT(void, png_set_unknown_chunks) PNGARG((png_structp png_ptr,
2175 png_infop info_ptr, png_unknown_chunkp unknowns, int num_unknowns));
2176 extern PNG_EXPORT(void, png_set_unknown_chunk_location)
2177 PNGARG((png_structp png_ptr, png_infop info_ptr, int chunk, int location));
2178 extern PNG_EXPORT(png_uint_32,png_get_unknown_chunks) PNGARG((png_structp
2179 png_ptr, png_infop info_ptr, png_unknown_chunkpp entries));
2182 /* Png_free_data() will turn off the "valid" flag for anything it frees.
2183 If you need to turn it off for a chunk that your application has freed,
2184 you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK); */
2185 extern PNG_EXPORT(void, png_set_invalid) PNGARG((png_structp png_ptr,
2186 png_infop info_ptr, int mask));
2188 #if defined(PNG_INFO_IMAGE_SUPPORTED)
2189 /* The "params" pointer is currently not used and is for future expansion. */
2190 extern PNG_EXPORT(void, png_read_png) PNGARG((png_structp png_ptr,
2194 extern PNG_EXPORT(void, png_write_png) PNGARG((png_structp png_ptr,
2200 /* Define PNG_DEBUG at compile time for debugging information. Higher
2201 * numbers for PNG_DEBUG mean more debugging information. This has
2202 * only been added since version 0.95 so it is not implemented throughout
2203 * libpng yet, but more support will be added as needed.
2207 #if !defined(PNG_DEBUG_FILE) && defined(_MSC_VER)
2210 #define png_debug(l,m) _RPT0(_CRT_WARN,m)
2211 #define png_debug1(l,m,p1) _RPT1(_CRT_WARN,m,p1)
2212 #define png_debug2(l,m,p1,p2) _RPT2(_CRT_WARN,m,p1,p2)
2214 #else /* PNG_DEBUG_FILE || !_MSC_VER */
2215 #ifndef PNG_DEBUG_FILE
2216 #define PNG_DEBUG_FILE stderr
2217 #endif /* PNG_DEBUG_FILE */
2219 #define png_debug(l,m) \
2222 fprintf(PNG_DEBUG_FILE,"%s"m,(num_tabs==1 ? "\t" : \
2223 (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":"")))); \
2225 #define png_debug1(l,m,p1) \
2228 fprintf(PNG_DEBUG_FILE,"%s"m,(num_tabs==1 ? "\t" : \
2229 (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1); \
2231 #define png_debug2(l,m,p1,p2) \
2234 fprintf(PNG_DEBUG_FILE,"%s"m,(num_tabs==1 ? "\t" : \
2235 (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1,p2); \
2237 #endif /* (PNG_DEBUG > 1) */
2238 #endif /* _MSC_VER */
2239 #endif /* (PNG_DEBUG > 0) */
2240 #endif /* PNG_DEBUG */
2242 #define png_debug(l, m)
2245 #define png_debug1(l, m, p1)
2248 #define png_debug2(l, m, p1, p2)
2251 extern PNG_EXPORT(png_bytep,png_sig_bytes) PNGARG((void));
2253 extern PNG_EXPORT(png_charp,png_get_copyright) PNGARG((png_structp png_ptr));
2254 extern PNG_EXPORT(png_charp,png_get_header_ver) PNGARG((png_structp png_ptr));
2255 extern PNG_EXPORT(png_charp,png_get_header_version) PNGARG((png_structp png_ptr));
2256 extern PNG_EXPORT(png_charp,png_get_libpng_ver) PNGARG((png_structp png_ptr));
2258 #ifdef PNG_MNG_FEATURES_SUPPORTED
2259 extern PNG_EXPORT(png_uint_32,png_permit_mng_features) PNGARG((png_structp
2260 png_ptr, png_uint_32 mng_features_permitted));
2263 /* Added to version 1.2.0 */
2264 #if defined(PNG_ASSEMBLER_CODE_SUPPORTED)
2265 #define PNG_ASM_FLAG_MMX_SUPPORT_COMPILED 0x01 /* not user-settable */
2266 #define PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU 0x02 /* not user-settable */
2267 #define PNG_ASM_FLAG_MMX_READ_COMBINE_ROW 0x04
2268 #define PNG_ASM_FLAG_MMX_READ_INTERLACE 0x08
2269 #define PNG_ASM_FLAG_MMX_READ_FILTER_SUB 0x10
2270 #define PNG_ASM_FLAG_MMX_READ_FILTER_UP 0x20
2271 #define PNG_ASM_FLAG_MMX_READ_FILTER_AVG 0x40
2272 #define PNG_ASM_FLAG_MMX_READ_FILTER_PAETH 0x80
2273 #define PNG_ASM_FLAGS_INITIALIZED 0x80000000 /* not user-settable */
2275 #define PNG_MMX_READ_FLAGS ( PNG_ASM_FLAG_MMX_READ_COMBINE_ROW \
2276 | PNG_ASM_FLAG_MMX_READ_INTERLACE \
2277 | PNG_ASM_FLAG_MMX_READ_FILTER_SUB \
2278 | PNG_ASM_FLAG_MMX_READ_FILTER_UP \
2279 | PNG_ASM_FLAG_MMX_READ_FILTER_AVG \
2280 | PNG_ASM_FLAG_MMX_READ_FILTER_PAETH )
2281 #define PNG_MMX_WRITE_FLAGS ( 0 )
2283 #define PNG_MMX_FLAGS ( PNG_ASM_FLAG_MMX_SUPPORT_COMPILED \
2284 | PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU \
2285 | PNG_MMX_READ_FLAGS \
2286 | PNG_MMX_WRITE_FLAGS )
2288 #define PNG_SELECT_READ 1
2289 #define PNG_SELECT_WRITE 2
2293 extern PNG_EXPORT(png_uint_32,png_get_mmx_flagmask)
2294 PNGARG((int flag_select, int *compilerID));
2297 extern PNG_EXPORT(png_uint_32,png_get_asm_flagmask)
2298 PNGARG((int flag_select));
2301 extern PNG_EXPORT(png_uint_32,png_get_asm_flags)
2302 PNGARG((png_structp png_ptr));
2305 extern PNG_EXPORT(png_byte,png_get_mmx_bitdepth_threshold)
2306 PNGARG((png_structp png_ptr));
2309 extern PNG_EXPORT(png_uint_32,png_get_mmx_rowbytes_threshold)
2310 PNGARG((png_structp png_ptr));
2313 extern PNG_EXPORT(void,png_set_asm_flags)
2314 PNGARG((png_structp png_ptr, png_uint_32 asm_flags));
2317 extern PNG_EXPORT(void,png_set_mmx_thresholds)
2318 PNGARG((png_structp png_ptr, png_byte mmx_bitdepth_threshold,
2319 png_uint_32 mmx_rowbytes_threshold));
2321 #endif /* PNG_ASSEMBLER_CODE_SUPPORTED */
2323 /* png.c, pnggccrd.c, or pngvcrd.c */
2324 extern PNG_EXPORT(int,png_mmx_support) PNGARG((void));
2326 /* Strip the prepended error numbers ("#nnn ") from error and warning
2327 * messages before passing them to the error or warning handler. */
2328 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
2329 extern PNG_EXPORT(void,png_set_strip_error_numbers) PNGARG((png_structp
2330 png_ptr, png_uint_32 strip_mode));
2333 /* Maintainer: Put new public prototypes here ^, in libpng.3, and project defs */
2335 #define PNG_HEADER_VERSION_STRING \
2336 " libpng version 1.2.0 - September 1, 2001 (header)\n"
2338 #ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
2339 /* With these routines we avoid an integer divide, which will be slower on
2340 * most machines. However, it does take more operations than the corresponding
2341 * divide method, so it may be slower on a few RISC systems. There are two
2342 * shifts (by 8 or 16 bits) and an addition, versus a single integer divide.
2344 * Note that the rounding factors are NOT supposed to be the same! 128 and
2345 * 32768 are correct for the NODIV code; 127 and 32767 are correct for the
2348 * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
2351 /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */
2353 # define png_composite(composite, fg, alpha, bg) \
2354 { png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) * (png_uint_16)(alpha) \
2355 + (png_uint_16)(bg)*(png_uint_16)(255 - \
2356 (png_uint_16)(alpha)) + (png_uint_16)128); \
2357 (composite) = (png_byte)((temp + (temp >> 8)) >> 8); }
2359 # define png_composite_16(composite, fg, alpha, bg) \
2360 { png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) * (png_uint_32)(alpha) \
2361 + (png_uint_32)(bg)*(png_uint_32)(65535L - \
2362 (png_uint_32)(alpha)) + (png_uint_32)32768L); \
2363 (composite) = (png_uint_16)((temp + (temp >> 16)) >> 16); }
2365 #else /* standard method using integer division */
2367 # define png_composite(composite, fg, alpha, bg) \
2368 (composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) + \
2369 (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \
2370 (png_uint_16)127) / 255)
2372 # define png_composite_16(composite, fg, alpha, bg) \
2373 (composite) = (png_uint_16)(((png_uint_32)(fg) * (png_uint_32)(alpha) + \
2374 (png_uint_32)(bg)*(png_uint_32)(65535L - (png_uint_32)(alpha)) + \
2375 (png_uint_32)32767) / (png_uint_32)65535L)
2377 #endif /* PNG_READ_COMPOSITE_NODIV_SUPPORTED */
2379 /* These next functions are used internally in the code. They generally
2380 * shouldn't be used unless you are writing code to add or replace some
2381 * functionality in libpng. More information about most functions can
2382 * be found in the files where the functions are located.
2385 #if defined(PNG_INTERNAL)
2387 /* Various modes of operation. Note that after an init, mode is set to
2388 * zero automatically when the structure is created.
2390 #define PNG_HAVE_IHDR 0x01
2391 #define PNG_HAVE_PLTE 0x02
2392 #define PNG_HAVE_IDAT 0x04
2393 #define PNG_AFTER_IDAT 0x08
2394 #define PNG_HAVE_IEND 0x10
2395 #define PNG_HAVE_gAMA 0x20
2396 #define PNG_HAVE_cHRM 0x40
2397 #define PNG_HAVE_sRGB 0x80
2398 #define PNG_HAVE_CHUNK_HEADER 0x100
2399 #define PNG_WROTE_tIME 0x200
2400 #define PNG_WROTE_INFO_BEFORE_PLTE 0x400
2401 #define PNG_BACKGROUND_IS_GRAY 0x800
2402 #define PNG_HAVE_PNG_SIGNATURE 0x1000
2404 /* flags for the transformations the PNG library does on the image data */
2405 #define PNG_BGR 0x0001
2406 #define PNG_INTERLACE 0x0002
2407 #define PNG_PACK 0x0004
2408 #define PNG_SHIFT 0x0008
2409 #define PNG_SWAP_BYTES 0x0010
2410 #define PNG_INVERT_MONO 0x0020
2411 #define PNG_DITHER 0x0040
2412 #define PNG_BACKGROUND 0x0080
2413 #define PNG_BACKGROUND_EXPAND 0x0100
2415 #define PNG_16_TO_8 0x0400
2416 #define PNG_RGBA 0x0800
2417 #define PNG_EXPAND 0x1000
2418 #define PNG_GAMMA 0x2000
2419 #define PNG_GRAY_TO_RGB 0x4000
2420 #define PNG_FILLER 0x8000L
2421 #define PNG_PACKSWAP 0x10000L
2422 #define PNG_SWAP_ALPHA 0x20000L
2423 #define PNG_STRIP_ALPHA 0x40000L
2424 #define PNG_INVERT_ALPHA 0x80000L
2425 #define PNG_USER_TRANSFORM 0x100000L
2426 #define PNG_RGB_TO_GRAY_ERR 0x200000L
2427 #define PNG_RGB_TO_GRAY_WARN 0x400000L
2428 #define PNG_RGB_TO_GRAY 0x600000L /* two bits, RGB_TO_GRAY_ERR|WARN */
2430 /* flags for png_create_struct */
2431 #define PNG_STRUCT_PNG 0x0001
2432 #define PNG_STRUCT_INFO 0x0002
2434 /* Scaling factor for filter heuristic weighting calculations */
2435 #define PNG_WEIGHT_SHIFT 8
2436 #define PNG_WEIGHT_FACTOR (1<<(PNG_WEIGHT_SHIFT))
2437 #define PNG_COST_SHIFT 3
2438 #define PNG_COST_FACTOR (1<<(PNG_COST_SHIFT))
2440 /* flags for the png_ptr->flags rather than declaring a byte for each one */
2441 #define PNG_FLAG_ZLIB_CUSTOM_STRATEGY 0x0001
2442 #define PNG_FLAG_ZLIB_CUSTOM_LEVEL 0x0002
2443 #define PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL 0x0004
2444 #define PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS 0x0008
2445 #define PNG_FLAG_ZLIB_CUSTOM_METHOD 0x0010
2446 #define PNG_FLAG_ZLIB_FINISHED 0x0020
2447 #define PNG_FLAG_ROW_INIT 0x0040
2448 #define PNG_FLAG_FILLER_AFTER 0x0080
2449 #define PNG_FLAG_CRC_ANCILLARY_USE 0x0100
2450 #define PNG_FLAG_CRC_ANCILLARY_NOWARN 0x0200
2451 #define PNG_FLAG_CRC_CRITICAL_USE 0x0400
2452 #define PNG_FLAG_CRC_CRITICAL_IGNORE 0x0800
2453 #define PNG_FLAG_FREE_PLTE 0x1000
2454 #define PNG_FLAG_FREE_TRNS 0x2000
2455 #define PNG_FLAG_FREE_HIST 0x4000
2456 #define PNG_FLAG_KEEP_UNKNOWN_CHUNKS 0x8000L
2457 #define PNG_FLAG_KEEP_UNSAFE_CHUNKS 0x10000L
2458 #define PNG_FLAG_LIBRARY_MISMATCH 0x20000L
2459 #define PNG_FLAG_STRIP_ERROR_NUMBERS 0x40000L
2460 #define PNG_FLAG_STRIP_ERROR_TEXT 0x80000L
2462 /* For use in png_set_keep_unknown, png_handle_as_unknown */
2463 #define HANDLE_CHUNK_AS_DEFAULT 0
2464 #define HANDLE_CHUNK_NEVER 1
2465 #define HANDLE_CHUNK_IF_SAFE 2
2466 #define HANDLE_CHUNK_ALWAYS 3
2468 #define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \
2469 PNG_FLAG_CRC_ANCILLARY_NOWARN)
2471 #define PNG_FLAG_CRC_CRITICAL_MASK (PNG_FLAG_CRC_CRITICAL_USE | \
2472 PNG_FLAG_CRC_CRITICAL_IGNORE)
2474 #define PNG_FLAG_CRC_MASK (PNG_FLAG_CRC_ANCILLARY_MASK | \
2475 PNG_FLAG_CRC_CRITICAL_MASK)
2477 /* save typing and make code easier to understand */
2478 #define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \
2479 abs((int)((c1).green) - (int)((c2).green)) + \
2480 abs((int)((c1).blue) - (int)((c2).blue)))
2482 /* variables declared in png.c - only it needs to define PNG_NO_EXTERN */
2483 #if !defined(PNG_NO_EXTERN) || defined(PNG_ALWAYS_EXTERN)
2484 /* place to hold the signature string for a PNG file. */
2485 #ifdef PNG_USE_GLOBAL_ARRAYS
2486 PNG_EXPORT_VAR (const png_byte FARDATA) png_sig[8];
2488 #define png_sig png_sig_bytes(NULL)
2490 #endif /* PNG_NO_EXTERN */
2492 /* Constant strings for known chunk types. If you need to add a chunk,
2493 * define the name here, and add an invocation of the macro in png.c and
2494 * wherever it's needed.
2496 #define PNG_IHDR const png_byte png_IHDR[5] = { 73, 72, 68, 82, '\0'}
2497 #define PNG_IDAT const png_byte png_IDAT[5] = { 73, 68, 65, 84, '\0'}
2498 #define PNG_IEND const png_byte png_IEND[5] = { 73, 69, 78, 68, '\0'}
2499 #define PNG_PLTE const png_byte png_PLTE[5] = { 80, 76, 84, 69, '\0'}
2500 #define PNG_bKGD const png_byte png_bKGD[5] = { 98, 75, 71, 68, '\0'}
2501 #define PNG_cHRM const png_byte png_cHRM[5] = { 99, 72, 82, 77, '\0'}
2502 #define PNG_gAMA const png_byte png_gAMA[5] = {103, 65, 77, 65, '\0'}
2503 #define PNG_hIST const png_byte png_hIST[5] = {104, 73, 83, 84, '\0'}
2504 #define PNG_iCCP const png_byte png_iCCP[5] = {105, 67, 67, 80, '\0'}
2505 #define PNG_iTXt const png_byte png_iTXt[5] = {105, 84, 88, 116, '\0'}
2506 #define PNG_oFFs const png_byte png_oFFs[5] = {111, 70, 70, 115, '\0'}
2507 #define PNG_pCAL const png_byte png_pCAL[5] = {112, 67, 65, 76, '\0'}
2508 #define PNG_sCAL const png_byte png_sCAL[5] = {115, 67, 65, 76, '\0'}
2509 #define PNG_pHYs const png_byte png_pHYs[5] = {112, 72, 89, 115, '\0'}
2510 #define PNG_sBIT const png_byte png_sBIT[5] = {115, 66, 73, 84, '\0'}
2511 #define PNG_sPLT const png_byte png_sPLT[5] = {115, 80, 76, 84, '\0'}
2512 #define PNG_sRGB const png_byte png_sRGB[5] = {115, 82, 71, 66, '\0'}
2513 #define PNG_tEXt const png_byte png_tEXt[5] = {116, 69, 88, 116, '\0'}
2514 #define PNG_tIME const png_byte png_tIME[5] = {116, 73, 77, 69, '\0'}
2515 #define PNG_tRNS const png_byte png_tRNS[5] = {116, 82, 78, 83, '\0'}
2516 #define PNG_zTXt const png_byte png_zTXt[5] = {122, 84, 88, 116, '\0'}
2518 #ifdef PNG_USE_GLOBAL_ARRAYS
2519 PNG_EXPORT_VAR (const png_byte FARDATA) png_IHDR[5];
2520 PNG_EXPORT_VAR (const png_byte FARDATA) png_IDAT[5];
2521 PNG_EXPORT_VAR (const png_byte FARDATA) png_IEND[5];
2522 PNG_EXPORT_VAR (const png_byte FARDATA) png_PLTE[5];
2523 PNG_EXPORT_VAR (const png_byte FARDATA) png_bKGD[5];
2524 PNG_EXPORT_VAR (const png_byte FARDATA) png_cHRM[5];
2525 PNG_EXPORT_VAR (const png_byte FARDATA) png_gAMA[5];
2526 PNG_EXPORT_VAR (const png_byte FARDATA) png_hIST[5];
2527 PNG_EXPORT_VAR (const png_byte FARDATA) png_iCCP[5];
2528 PNG_EXPORT_VAR (const png_byte FARDATA) png_iTXt[5];
2529 PNG_EXPORT_VAR (const png_byte FARDATA) png_oFFs[5];
2530 PNG_EXPORT_VAR (const png_byte FARDATA) png_pCAL[5];
2531 PNG_EXPORT_VAR (const png_byte FARDATA) png_sCAL[5];
2532 PNG_EXPORT_VAR (const png_byte FARDATA) png_pHYs[5];
2533 PNG_EXPORT_VAR (const png_byte FARDATA) png_sBIT[5];
2534 PNG_EXPORT_VAR (const png_byte FARDATA) png_sPLT[5];
2535 PNG_EXPORT_VAR (const png_byte FARDATA) png_sRGB[5];
2536 PNG_EXPORT_VAR (const png_byte FARDATA) png_tEXt[5];
2537 PNG_EXPORT_VAR (const png_byte FARDATA) png_tIME[5];
2538 PNG_EXPORT_VAR (const png_byte FARDATA) png_tRNS[5];
2539 PNG_EXPORT_VAR (const png_byte FARDATA) png_zTXt[5];
2540 #endif /* PNG_USE_GLOBAL_ARRAYS */
2543 /* Inline macros to do direct reads of bytes from the input buffer. These
2544 * require that you are using an architecture that uses PNG byte ordering
2545 * (MSB first) and supports unaligned data storage. I think that PowerPC
2546 * in big-endian mode and 680x0 are the only ones that will support this.
2547 * The x86 line of processors definitely do not. The png_get_int_32()
2548 * routine also assumes we are using two's complement format for negative
2549 * values, which is almost certainly true.
2551 #if defined(PNG_READ_BIG_ENDIAN_SUPPORTED)
2552 # if defined(PNG_pCAL_SUPPORTED) || defined(PNG_oFFs_SUPPORTED)
2553 # define png_get_int_32(buf) ( *((png_int_32p) (buf)))
2555 # define png_get_uint_32(buf) ( *((png_uint_32p) (buf)))
2556 # define png_get_uint_16(buf) ( *((png_uint_16p) (buf)))
2558 # if defined(PNG_pCAL_SUPPORTED) || defined(PNG_oFFs_SUPPORTED)
2559 PNG_EXTERN png_int_32 png_get_int_32 PNGARG((png_bytep buf));
2561 PNG_EXTERN png_uint_32 png_get_uint_32 PNGARG((png_bytep buf));
2562 PNG_EXTERN png_uint_16 png_get_uint_16 PNGARG((png_bytep buf));
2563 #endif /* !PNG_READ_BIG_ENDIAN_SUPPORTED */
2565 /* Initialize png_ptr struct for reading, and allocate any other memory.
2566 * (old interface - DEPRECATED - use png_create_read_struct instead).
2568 extern PNG_EXPORT(void,png_read_init) PNGARG((png_structp png_ptr));
2569 #define png_read_init(png_ptr) png_read_init_3(&png_ptr, \
2570 PNG_LIBPNG_VER_STRING, sizeof(png_struct));
2571 extern PNG_EXPORT(void,png_read_init_3) PNGARG((png_structpp ptr_ptr,
2572 png_const_charp user_png_ver, png_size_t png_struct_size));
2573 extern PNG_EXPORT(void,png_read_init_2) PNGARG((png_structp png_ptr,
2574 png_const_charp user_png_ver, png_size_t png_struct_size, png_size_t
2577 /* Initialize png_ptr struct for writing, and allocate any other memory.
2578 * (old interface - DEPRECATED - use png_create_write_struct instead).
2580 extern PNG_EXPORT(void,png_write_init) PNGARG((png_structp png_ptr));
2581 #define png_write_init(png_ptr) png_write_init_3(&png_ptr, \
2582 PNG_LIBPNG_VER_STRING, sizeof(png_struct));
2583 extern PNG_EXPORT(void,png_write_init_3) PNGARG((png_structpp ptr_ptr,
2584 png_const_charp user_png_ver, png_size_t png_struct_size));
2585 extern PNG_EXPORT(void,png_write_init_2) PNGARG((png_structp png_ptr,
2586 png_const_charp user_png_ver, png_size_t png_struct_size, png_size_t
2589 /* Allocate memory for an internal libpng struct */
2590 PNG_EXTERN png_voidp png_create_struct PNGARG((int type));
2592 /* Free memory from internal libpng struct */
2593 PNG_EXTERN void png_destroy_struct PNGARG((png_voidp struct_ptr));
2595 PNG_EXTERN png_voidp png_create_struct_2 PNGARG((int type, png_malloc_ptr
2596 malloc_fn, png_voidp mem_ptr));
2597 PNG_EXTERN void png_destroy_struct_2 PNGARG((png_voidp struct_ptr,
2598 png_free_ptr free_fn, png_voidp mem_ptr));
2600 /* Free any memory that info_ptr points to and reset struct. */
2601 PNG_EXTERN void png_info_destroy PNGARG((png_structp png_ptr,
2602 png_infop info_ptr));
2604 /* Function to allocate memory for zlib. */
2605 PNG_EXTERN voidpf png_zalloc PNGARG((voidpf png_ptr, uInt items, uInt size));
2607 /* Function to free memory for zlib */
2608 PNG_EXTERN void png_zfree PNGARG((voidpf png_ptr, voidpf ptr));
2610 /* Reset the CRC variable */
2611 PNG_EXTERN void png_reset_crc PNGARG((png_structp png_ptr));
2613 /* Write the "data" buffer to whatever output you are using. */
2614 PNG_EXTERN void png_write_data PNGARG((png_structp png_ptr, png_bytep data,
2615 png_size_t length));
2617 /* Read data from whatever input you are using into the "data" buffer */
2618 PNG_EXTERN void png_read_data PNGARG((png_structp png_ptr, png_bytep data,
2619 png_size_t length));
2621 /* Read bytes into buf, and update png_ptr->crc */
2622 PNG_EXTERN void png_crc_read PNGARG((png_structp png_ptr, png_bytep buf,
2623 png_size_t length));
2625 /* Decompress data in a chunk that uses compression */
2626 #if defined(PNG_zTXt_SUPPORTED) || defined(PNG_iTXt_SUPPORTED) || \
2627 defined(PNG_iCCP_SUPPORTED) || defined(PNG_sPLT_SUPPORTED)
2628 PNG_EXTERN png_charp png_decompress_chunk PNGARG((png_structp png_ptr,
2629 int comp_type, png_charp chunkdata, png_size_t chunklength,
2630 png_size_t prefix_length, png_size_t *data_length));
2633 /* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */
2634 PNG_EXTERN int png_crc_finish PNGARG((png_structp png_ptr, png_uint_32 skip));
2636 /* Read the CRC from the file and compare it to the libpng calculated CRC */
2637 PNG_EXTERN int png_crc_error PNGARG((png_structp png_ptr));
2639 /* Calculate the CRC over a section of data. Note that we are only
2640 * passing a maximum of 64K on systems that have this as a memory limit,
2641 * since this is the maximum buffer size we can specify.
2643 PNG_EXTERN void png_calculate_crc PNGARG((png_structp png_ptr, png_bytep ptr,
2644 png_size_t length));
2646 #if defined(PNG_WRITE_FLUSH_SUPPORTED)
2647 PNG_EXTERN void png_flush PNGARG((png_structp png_ptr));
2650 /* Place a 32-bit number into a buffer in PNG byte order (big-endian).
2651 * The only currently known PNG chunks that use signed numbers are
2652 * the ancillary extension chunks, oFFs and pCAL.
2654 PNG_EXTERN void png_save_uint_32 PNGARG((png_bytep buf, png_uint_32 i));
2656 #if defined(PNG_WRITE_pCAL_SUPPORTED) || defined(PNG_WRITE_oFFs_SUPPORTED)
2657 PNG_EXTERN void png_save_int_32 PNGARG((png_bytep buf, png_int_32 i));
2660 /* Place a 16-bit number into a buffer in PNG byte order.
2661 * The parameter is declared unsigned int, not png_uint_16,
2662 * just to avoid potential problems on pre-ANSI C compilers.
2664 PNG_EXTERN void png_save_uint_16 PNGARG((png_bytep buf, unsigned int i));
2666 /* simple function to write the signature */
2667 PNG_EXTERN void png_write_sig PNGARG((png_structp png_ptr));
2669 /* write various chunks */
2671 /* Write the IHDR chunk, and update the png_struct with the necessary
2674 PNG_EXTERN void png_write_IHDR PNGARG((png_structp png_ptr, png_uint_32 width,
2676 int bit_depth, int color_type, int compression_method, int filter_method,
2677 int interlace_method));
2679 PNG_EXTERN void png_write_PLTE PNGARG((png_structp png_ptr, png_colorp palette,
2680 png_uint_32 num_pal));
2682 PNG_EXTERN void png_write_IDAT PNGARG((png_structp png_ptr, png_bytep data,
2683 png_size_t length));
2685 PNG_EXTERN void png_write_IEND PNGARG((png_structp png_ptr));
2687 #if defined(PNG_WRITE_gAMA_SUPPORTED)
2688 #ifdef PNG_FLOATING_POINT_SUPPORTED
2689 PNG_EXTERN void png_write_gAMA PNGARG((png_structp png_ptr, double file_gamma));
2691 #ifdef PNG_FIXED_POINT_SUPPORTED
2692 PNG_EXTERN void png_write_gAMA_fixed PNGARG((png_structp png_ptr, png_fixed_point
2697 #if defined(PNG_WRITE_sBIT_SUPPORTED)
2698 PNG_EXTERN void png_write_sBIT PNGARG((png_structp png_ptr, png_color_8p sbit,
2702 #if defined(PNG_WRITE_cHRM_SUPPORTED)
2703 #ifdef PNG_FLOATING_POINT_SUPPORTED
2704 PNG_EXTERN void png_write_cHRM PNGARG((png_structp png_ptr,
2705 double white_x, double white_y,
2706 double red_x, double red_y, double green_x, double green_y,
2707 double blue_x, double blue_y));
2709 #ifdef PNG_FIXED_POINT_SUPPORTED
2710 PNG_EXTERN void png_write_cHRM_fixed PNGARG((png_structp png_ptr,
2711 png_fixed_point int_white_x, png_fixed_point int_white_y,
2712 png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
2713 int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
2714 png_fixed_point int_blue_y));
2718 #if defined(PNG_WRITE_sRGB_SUPPORTED)
2719 PNG_EXTERN void png_write_sRGB PNGARG((png_structp png_ptr,
2723 #if defined(PNG_WRITE_iCCP_SUPPORTED)
2724 PNG_EXTERN void png_write_iCCP PNGARG((png_structp png_ptr,
2725 png_charp name, int compression_type,
2726 png_charp profile, int proflen));
2727 /* Note to maintainer: profile should be png_bytep */
2730 #if defined(PNG_WRITE_sPLT_SUPPORTED)
2731 PNG_EXTERN void png_write_sPLT PNGARG((png_structp png_ptr,
2732 png_sPLT_tp palette));
2735 #if defined(PNG_WRITE_tRNS_SUPPORTED)
2736 PNG_EXTERN void png_write_tRNS PNGARG((png_structp png_ptr, png_bytep trans,
2737 png_color_16p values, int number, int color_type));
2740 #if defined(PNG_WRITE_bKGD_SUPPORTED)
2741 PNG_EXTERN void png_write_bKGD PNGARG((png_structp png_ptr,
2742 png_color_16p values, int color_type));
2745 #if defined(PNG_WRITE_hIST_SUPPORTED)
2746 PNG_EXTERN void png_write_hIST PNGARG((png_structp png_ptr, png_uint_16p hist,
2750 #if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \
2751 defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
2752 PNG_EXTERN png_size_t png_check_keyword PNGARG((png_structp png_ptr,
2753 png_charp key, png_charpp new_key));
2756 #if defined(PNG_WRITE_tEXt_SUPPORTED)
2757 PNG_EXTERN void png_write_tEXt PNGARG((png_structp png_ptr, png_charp key,
2758 png_charp text, png_size_t text_len));
2761 #if defined(PNG_WRITE_zTXt_SUPPORTED)
2762 PNG_EXTERN void png_write_zTXt PNGARG((png_structp png_ptr, png_charp key,
2763 png_charp text, png_size_t text_len, int compression));
2766 #if defined(PNG_WRITE_iTXt_SUPPORTED)
2767 PNG_EXTERN void png_write_iTXt PNGARG((png_structp png_ptr,
2768 int compression, png_charp key, png_charp lang, png_charp lang_key,
2772 #if defined(PNG_WRITE_oFFs_SUPPORTED)
2773 PNG_EXTERN void png_write_oFFs PNGARG((png_structp png_ptr,
2774 png_int_32 x_offset, png_int_32 y_offset, int unit_type));
2777 #if defined(PNG_WRITE_pCAL_SUPPORTED)
2778 PNG_EXTERN void png_write_pCAL PNGARG((png_structp png_ptr, png_charp purpose,
2779 png_int_32 X0, png_int_32 X1, int type, int nparams,
2780 png_charp units, png_charpp params));
2783 #if defined(PNG_WRITE_pHYs_SUPPORTED)
2784 PNG_EXTERN void png_write_pHYs PNGARG((png_structp png_ptr,
2785 png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit,
2789 #if defined(PNG_WRITE_tIME_SUPPORTED)
2790 PNG_EXTERN void png_write_tIME PNGARG((png_structp png_ptr,
2791 png_timep mod_time));
2794 #if defined(PNG_WRITE_sCAL_SUPPORTED)
2795 #if defined(PNG_FLOATING_POINT_SUPPORTED) && !defined(PNG_NO_STDIO)
2796 PNG_EXTERN void png_write_sCAL PNGARG((png_structp png_ptr,
2797 int unit, double width, double height));
2799 #ifdef PNG_FIXED_POINT_SUPPORTED
2800 PNG_EXTERN void png_write_sCAL_s PNGARG((png_structp png_ptr,
2801 int unit, png_charp width, png_charp height));
2806 /* Called when finished processing a row of data */
2807 PNG_EXTERN void png_write_finish_row PNGARG((png_structp png_ptr));
2809 /* Internal use only. Called before first row of data */
2810 PNG_EXTERN void png_write_start_row PNGARG((png_structp png_ptr));
2812 #if defined(PNG_READ_GAMMA_SUPPORTED)
2813 PNG_EXTERN void png_build_gamma_table PNGARG((png_structp png_ptr));
2816 /* combine a row of data, dealing with alpha, etc. if requested */
2817 PNG_EXTERN void png_combine_row PNGARG((png_structp png_ptr, png_bytep row,
2820 #if defined(PNG_READ_INTERLACING_SUPPORTED)
2821 /* expand an interlaced row */
2822 /* OLD pre-1.0.9 interface:
2823 PNG_EXTERN void png_do_read_interlace PNGARG((png_row_infop row_info,
2824 png_bytep row, int pass, png_uint_32 transformations));
2826 PNG_EXTERN void png_do_read_interlace PNGARG((png_structp png_ptr));
2829 /* GRR TO DO (2.0 or whenever): simplify other internal calling interfaces */
2831 #if defined(PNG_WRITE_INTERLACING_SUPPORTED)
2832 /* grab pixels out of a row for an interlaced pass */
2833 PNG_EXTERN void png_do_write_interlace PNGARG((png_row_infop row_info,
2834 png_bytep row, int pass));
2837 /* unfilter a row */
2838 PNG_EXTERN void png_read_filter_row PNGARG((png_structp png_ptr,
2839 png_row_infop row_info, png_bytep row, png_bytep prev_row, int filter));
2841 /* Choose the best filter to use and filter the row data */
2842 PNG_EXTERN void png_write_find_filter PNGARG((png_structp png_ptr,
2843 png_row_infop row_info));
2845 /* Write out the filtered row. */
2846 PNG_EXTERN void png_write_filtered_row PNGARG((png_structp png_ptr,
2847 png_bytep filtered_row));
2848 /* finish a row while reading, dealing with interlacing passes, etc. */
2849 PNG_EXTERN void png_read_finish_row PNGARG((png_structp png_ptr));
2851 /* initialize the row buffers, etc. */
2852 PNG_EXTERN void png_read_start_row PNGARG((png_structp png_ptr));
2853 /* optional call to update the users info structure */
2854 PNG_EXTERN void png_read_transform_info PNGARG((png_structp png_ptr,
2855 png_infop info_ptr));
2857 /* these are the functions that do the transformations */
2858 #if defined(PNG_READ_FILLER_SUPPORTED)
2859 PNG_EXTERN void png_do_read_filler PNGARG((png_row_infop row_info,
2860 png_bytep row, png_uint_32 filler, png_uint_32 flags));
2863 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED)
2864 PNG_EXTERN void png_do_read_swap_alpha PNGARG((png_row_infop row_info,
2868 #if defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
2869 PNG_EXTERN void png_do_write_swap_alpha PNGARG((png_row_infop row_info,
2873 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)
2874 PNG_EXTERN void png_do_read_invert_alpha PNGARG((png_row_infop row_info,
2878 #if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
2879 PNG_EXTERN void png_do_write_invert_alpha PNGARG((png_row_infop row_info,
2883 #if defined(PNG_WRITE_FILLER_SUPPORTED) || \
2884 defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
2885 PNG_EXTERN void png_do_strip_filler PNGARG((png_row_infop row_info,
2886 png_bytep row, png_uint_32 flags));
2889 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
2890 PNG_EXTERN void png_do_swap PNGARG((png_row_infop row_info, png_bytep row));
2893 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || defined(PNG_WRITE_PACKSWAP_SUPPORTED)
2894 PNG_EXTERN void png_do_packswap PNGARG((png_row_infop row_info, png_bytep row));
2897 #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
2898 PNG_EXTERN int png_do_rgb_to_gray PNGARG((png_structp png_ptr, png_row_infop
2899 row_info, png_bytep row));
2902 #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
2903 PNG_EXTERN void png_do_gray_to_rgb PNGARG((png_row_infop row_info,
2907 #if defined(PNG_READ_PACK_SUPPORTED)
2908 PNG_EXTERN void png_do_unpack PNGARG((png_row_infop row_info, png_bytep row));
2911 #if defined(PNG_READ_SHIFT_SUPPORTED)
2912 PNG_EXTERN void png_do_unshift PNGARG((png_row_infop row_info, png_bytep row,
2913 png_color_8p sig_bits));
2916 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
2917 PNG_EXTERN void png_do_invert PNGARG((png_row_infop row_info, png_bytep row));
2920 #if defined(PNG_READ_16_TO_8_SUPPORTED)
2921 PNG_EXTERN void png_do_chop PNGARG((png_row_infop row_info, png_bytep row));
2924 #if defined(PNG_READ_DITHER_SUPPORTED)
2925 PNG_EXTERN void png_do_dither PNGARG((png_row_infop row_info,
2926 png_bytep row, png_bytep palette_lookup, png_bytep dither_lookup));
2928 # if defined(PNG_CORRECT_PALETTE_SUPPORTED)
2929 PNG_EXTERN void png_correct_palette PNGARG((png_structp png_ptr,
2930 png_colorp palette, int num_palette));
2934 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
2935 PNG_EXTERN void png_do_bgr PNGARG((png_row_infop row_info, png_bytep row));
2938 #if defined(PNG_WRITE_PACK_SUPPORTED)
2939 PNG_EXTERN void png_do_pack PNGARG((png_row_infop row_info,
2940 png_bytep row, png_uint_32 bit_depth));
2943 #if defined(PNG_WRITE_SHIFT_SUPPORTED)
2944 PNG_EXTERN void png_do_shift PNGARG((png_row_infop row_info, png_bytep row,
2945 png_color_8p bit_depth));
2948 #if defined(PNG_READ_BACKGROUND_SUPPORTED)
2949 PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info, png_bytep row,
2950 png_color_16p trans_values, png_color_16p background,
2951 png_color_16p background_1,
2952 png_bytep gamma_table, png_bytep gamma_from_1, png_bytep gamma_to_1,
2953 png_uint_16pp gamma_16, png_uint_16pp gamma_16_from_1,
2954 png_uint_16pp gamma_16_to_1, int gamma_shift));
2957 #if defined(PNG_READ_GAMMA_SUPPORTED)
2958 PNG_EXTERN void png_do_gamma PNGARG((png_row_infop row_info, png_bytep row,
2959 png_bytep gamma_table, png_uint_16pp gamma_16_table,
2963 #if defined(PNG_READ_EXPAND_SUPPORTED)
2964 PNG_EXTERN void png_do_expand_palette PNGARG((png_row_infop row_info,
2965 png_bytep row, png_colorp palette, png_bytep trans, int num_trans));
2966 PNG_EXTERN void png_do_expand PNGARG((png_row_infop row_info,
2967 png_bytep row, png_color_16p trans_value));
2970 /* The following decodes the appropriate chunks, and does error correction,
2971 * then calls the appropriate callback for the chunk if it is valid.
2974 /* decode the IHDR chunk */
2975 PNG_EXTERN void png_handle_IHDR PNGARG((png_structp png_ptr, png_infop info_ptr,
2976 png_uint_32 length));
2977 PNG_EXTERN void png_handle_PLTE PNGARG((png_structp png_ptr, png_infop info_ptr,
2978 png_uint_32 length));
2979 PNG_EXTERN void png_handle_IEND PNGARG((png_structp png_ptr, png_infop info_ptr,
2980 png_uint_32 length));
2982 #if defined(PNG_READ_bKGD_SUPPORTED)
2983 PNG_EXTERN void png_handle_bKGD PNGARG((png_structp png_ptr, png_infop info_ptr,
2984 png_uint_32 length));
2987 #if defined(PNG_READ_cHRM_SUPPORTED)
2988 PNG_EXTERN void png_handle_cHRM PNGARG((png_structp png_ptr, png_infop info_ptr,
2989 png_uint_32 length));
2992 #if defined(PNG_READ_gAMA_SUPPORTED)
2993 PNG_EXTERN void png_handle_gAMA PNGARG((png_structp png_ptr, png_infop info_ptr,
2994 png_uint_32 length));
2997 #if defined(PNG_READ_hIST_SUPPORTED)
2998 PNG_EXTERN void png_handle_hIST PNGARG((png_structp png_ptr, png_infop info_ptr,
2999 png_uint_32 length));
3002 #if defined(PNG_READ_iCCP_SUPPORTED)
3003 extern void png_handle_iCCP PNGARG((png_structp png_ptr, png_infop info_ptr,
3004 png_uint_32 length));
3005 #endif /* PNG_READ_iCCP_SUPPORTED */
3007 #if defined(PNG_READ_iTXt_SUPPORTED)
3008 PNG_EXTERN void png_handle_iTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
3009 png_uint_32 length));
3012 #if defined(PNG_READ_oFFs_SUPPORTED)
3013 PNG_EXTERN void png_handle_oFFs PNGARG((png_structp png_ptr, png_infop info_ptr,
3014 png_uint_32 length));
3017 #if defined(PNG_READ_pCAL_SUPPORTED)
3018 PNG_EXTERN void png_handle_pCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
3019 png_uint_32 length));
3022 #if defined(PNG_READ_pHYs_SUPPORTED)
3023 PNG_EXTERN void png_handle_pHYs PNGARG((png_structp png_ptr, png_infop info_ptr,
3024 png_uint_32 length));
3027 #if defined(PNG_READ_sBIT_SUPPORTED)
3028 PNG_EXTERN void png_handle_sBIT PNGARG((png_structp png_ptr, png_infop info_ptr,
3029 png_uint_32 length));
3032 #if defined(PNG_READ_sCAL_SUPPORTED)
3033 PNG_EXTERN void png_handle_sCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
3034 png_uint_32 length));
3037 #if defined(PNG_READ_sPLT_SUPPORTED)
3038 extern void png_handle_sPLT PNGARG((png_structp png_ptr, png_infop info_ptr,
3039 png_uint_32 length));
3040 #endif /* PNG_READ_sPLT_SUPPORTED */
3042 #if defined(PNG_READ_sRGB_SUPPORTED)
3043 PNG_EXTERN void png_handle_sRGB PNGARG((png_structp png_ptr, png_infop info_ptr,
3044 png_uint_32 length));
3047 #if defined(PNG_READ_tEXt_SUPPORTED)
3048 PNG_EXTERN void png_handle_tEXt PNGARG((png_structp png_ptr, png_infop info_ptr,
3049 png_uint_32 length));
3052 #if defined(PNG_READ_tIME_SUPPORTED)
3053 PNG_EXTERN void png_handle_tIME PNGARG((png_structp png_ptr, png_infop info_ptr,
3054 png_uint_32 length));
3057 #if defined(PNG_READ_tRNS_SUPPORTED)
3058 PNG_EXTERN void png_handle_tRNS PNGARG((png_structp png_ptr, png_infop info_ptr,
3059 png_uint_32 length));
3062 #if defined(PNG_READ_zTXt_SUPPORTED)
3063 PNG_EXTERN void png_handle_zTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
3064 png_uint_32 length));
3067 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
3068 PNG_EXTERN int png_handle_as_unknown PNGARG((png_structp png_ptr, png_bytep
3072 PNG_EXTERN void png_handle_unknown PNGARG((png_structp png_ptr,
3073 png_infop info_ptr, png_uint_32 length));
3075 PNG_EXTERN void png_check_chunk_name PNGARG((png_structp png_ptr,
3076 png_bytep chunk_name));
3078 /* handle the transformations for reading and writing */
3079 PNG_EXTERN void png_do_read_transformations PNGARG((png_structp png_ptr));
3080 PNG_EXTERN void png_do_write_transformations PNGARG((png_structp png_ptr));
3082 PNG_EXTERN void png_init_read_transformations PNGARG((png_structp png_ptr));
3084 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
3085 PNG_EXTERN void png_push_read_chunk PNGARG((png_structp png_ptr,
3086 png_infop info_ptr));
3087 PNG_EXTERN void png_push_read_sig PNGARG((png_structp png_ptr,
3088 png_infop info_ptr));
3089 PNG_EXTERN void png_push_check_crc PNGARG((png_structp png_ptr));
3090 PNG_EXTERN void png_push_crc_skip PNGARG((png_structp png_ptr,
3091 png_uint_32 length));
3092 PNG_EXTERN void png_push_crc_finish PNGARG((png_structp png_ptr));
3093 PNG_EXTERN void png_push_fill_buffer PNGARG((png_structp png_ptr,
3094 png_bytep buffer, png_size_t length));
3095 PNG_EXTERN void png_push_save_buffer PNGARG((png_structp png_ptr));
3096 PNG_EXTERN void png_push_restore_buffer PNGARG((png_structp png_ptr,
3097 png_bytep buffer, png_size_t buffer_length));
3098 PNG_EXTERN void png_push_read_IDAT PNGARG((png_structp png_ptr));
3099 PNG_EXTERN void png_process_IDAT_data PNGARG((png_structp png_ptr,
3100 png_bytep buffer, png_size_t buffer_length));
3101 PNG_EXTERN void png_push_process_row PNGARG((png_structp png_ptr));
3102 PNG_EXTERN void png_push_handle_unknown PNGARG((png_structp png_ptr,
3103 png_infop info_ptr, png_uint_32 length));
3104 PNG_EXTERN void png_push_have_info PNGARG((png_structp png_ptr,
3105 png_infop info_ptr));
3106 PNG_EXTERN void png_push_have_end PNGARG((png_structp png_ptr,
3107 png_infop info_ptr));
3108 PNG_EXTERN void png_push_have_row PNGARG((png_structp png_ptr, png_bytep row));
3109 PNG_EXTERN void png_push_read_end PNGARG((png_structp png_ptr,
3110 png_infop info_ptr));
3111 PNG_EXTERN void png_process_some_data PNGARG((png_structp png_ptr,
3112 png_infop info_ptr));
3113 PNG_EXTERN void png_read_push_finish_row PNGARG((png_structp png_ptr));
3114 #if defined(PNG_READ_tEXt_SUPPORTED)
3115 PNG_EXTERN void png_push_handle_tEXt PNGARG((png_structp png_ptr,
3116 png_infop info_ptr, png_uint_32 length));
3117 PNG_EXTERN void png_push_read_tEXt PNGARG((png_structp png_ptr,
3118 png_infop info_ptr));
3120 #if defined(PNG_READ_zTXt_SUPPORTED)
3121 PNG_EXTERN void png_push_handle_zTXt PNGARG((png_structp png_ptr,
3122 png_infop info_ptr, png_uint_32 length));
3123 PNG_EXTERN void png_push_read_zTXt PNGARG((png_structp png_ptr,
3124 png_infop info_ptr));
3126 #if defined(PNG_READ_iTXt_SUPPORTED)
3127 PNG_EXTERN void png_push_handle_iTXt PNGARG((png_structp png_ptr,
3128 png_infop info_ptr, png_uint_32 length));
3129 PNG_EXTERN void png_push_read_iTXt PNGARG((png_structp png_ptr,
3130 png_infop info_ptr));
3133 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
3135 #ifdef PNG_MNG_FEATURES_SUPPORTED
3136 PNG_EXTERN void png_do_read_intrapixel PNGARG((png_row_infop row_info,
3138 PNG_EXTERN void png_do_write_intrapixel PNGARG((png_row_infop row_info,
3142 #if defined(PNG_ASSEMBLER_CODE_SUPPORTED)
3143 /* png.c */ /* PRIVATE */
3144 PNG_EXTERN void png_init_mmx_flags PNGARG((png_structp png_ptr));
3146 /* Maintainer: Put new private prototypes here ^ and in libpngpf.3 */
3148 #endif /* PNG_INTERNAL */
3154 #endif /* PNG_VERSION_INFO_ONLY */
3155 /* do not put anything past this line */