2 /* png.h - header file for PNG reference library
4 * libpng version 1.0.9 - January 31, 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 1.0.9 - January 31, 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
68 * Henceforth the source version will match the shared-library major
69 * and minor numbers; the shared-library major version number will be
70 * used for changes in backward compatibility, as it is intended. The
71 * PNG_LIBPNG_VER macro, which is not used within libpng but is available
72 * for applications, is an unsigned integer of the form xyyzz corresponding
73 * to the source version x.y.z (leading zeros in y and z). Beta versions
74 * were given the previous public release number plus a letter, until
75 * version 1.0.6j; from then on they were given the upcoming public
76 * release number plus "betaNN" or "rcN".
78 * Binary incompatibility exists only when applications make direct access
79 * to the info_ptr or png_ptr members through png.h, and the compiled
80 * application is loaded with a different version of the library.
82 * DLLNUM will change each time there are forward or backward changes
83 * in binary compatibility (e.g., when a new feature is added).
85 * See libpng.txt or libpng.3 for more information. The PNG specification
86 * is available as RFC 2083 <ftp://ftp.uu.net/graphics/png/documents/>
87 * and as a W3C Recommendation <http://www.w3.org/TR/REC.png.html>
91 * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
93 * If you modify libpng you may insert additional notices immediately following
96 * libpng versions 1.0.7, July 1, 2000, through 1.0.9, January 31, 2001, are
97 * Copyright (c) 2000, 2001 Glenn Randers-Pehrson, and are
98 * distributed according to the same disclaimer and license as libpng-1.0.6
99 * with the following individuals added to the list of Contributing Authors
101 * Simon-Pierre Cadieux
105 * and with the following additions to the disclaimer:
107 * There is no warranty against interference with your enjoyment of the
108 * library or against infringement. There is no warranty that our
109 * efforts or the library will fulfill any of your particular purposes
110 * or needs. This library is provided with all faults, and the entire
111 * risk of satisfactory quality, performance, accuracy, and effort is with
114 * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
115 * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson
116 * Distributed according to the same disclaimer and license as libpng-0.96,
117 * with the following individuals added to the list of Contributing Authors:
120 * Glenn Randers-Pehrson
123 * libpng versions 0.89, June 1996, through 0.96, May 1997, are
124 * Copyright (c) 1996, 1997 Andreas Dilger
125 * Distributed according to the same disclaimer and license as libpng-0.88,
126 * with the following individuals added to the list of Contributing Authors:
135 * libpng versions 0.5, May 1995, through 0.88, January 1996, are
136 * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
138 * For the purposes of this copyright and license, "Contributing Authors"
139 * is defined as the following set of individuals:
147 * The PNG Reference Library is supplied "AS IS". The Contributing Authors
148 * and Group 42, Inc. disclaim all warranties, expressed or implied,
149 * including, without limitation, the warranties of merchantability and of
150 * fitness for any purpose. The Contributing Authors and Group 42, Inc.
151 * assume no liability for direct, indirect, incidental, special, exemplary,
152 * or consequential damages, which may result from the use of the PNG
153 * Reference Library, even if advised of the possibility of such damage.
155 * Permission is hereby granted to use, copy, modify, and distribute this
156 * source code, or portions hereof, for any purpose, without fee, subject
157 * to the following restrictions:
159 * 1. The origin of this source code must not be misrepresented.
161 * 2. Altered versions must be plainly marked as such and must not
162 * be misrepresented as being the original source.
164 * 3. This Copyright notice may not be removed or altered from any
165 * source or altered source distribution.
167 * The Contributing Authors and Group 42, Inc. specifically permit, without
168 * fee, and encourage the use of this source code as a component to
169 * supporting the PNG file format in commercial products. If you use this
170 * source code in a product, acknowledgment is not required but would be
175 * A "png_get_copyright" function is available, for convenient use in "about"
176 * boxes and the like:
178 * printf("%s",png_get_copyright(NULL));
180 * Also, the PNG logo (in PNG format, of course) is supplied in the
181 * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
185 * Libpng is OSI Certified Open Source Software. OSI Certified is a
186 * certification mark of the Open Source Initiative.
190 * The contributing authors would like to thank all those who helped
191 * with testing, bug fixes, and patience. This wouldn't have been
192 * possible without all of you.
194 * Thanks to Frank J. T. Wojcik for helping with the documentation.
198 * Y2K compliance in libpng:
199 * =========================
203 * Since the PNG Development group is an ad-hoc body, we can't make
204 * an official declaration.
206 * This is your unofficial assurance that libpng from version 0.71 and
207 * upward through 1.0.9 are Y2K compliant. It is my belief that earlier
208 * versions were also Y2K compliant.
210 * Libpng only has three year fields. One is a 2-byte unsigned integer
211 * that will hold years up to 65535. The other two hold the date in text
212 * format, and will hold years up to 9999.
215 * "png_uint_16 year" in png_time_struct.
218 * "png_charp time_buffer" in png_struct and
219 * "near_time_buffer", which is a local character string in png.c.
221 * There are seven time-related functions:
222 * png.c: png_convert_to_rfc_1123() in png.c
223 * (formerly png_convert_to_rfc_1152() in error)
224 * png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
225 * png_convert_from_time_t() in pngwrite.c
226 * png_get_tIME() in pngget.c
227 * png_handle_tIME() in pngrutil.c, called in pngread.c
228 * png_set_tIME() in pngset.c
229 * png_write_tIME() in pngwutil.c, called in pngwrite.c
231 * All handle dates properly in a Y2K environment. The
232 * png_convert_from_time_t() function calls gmtime() to convert from system
233 * clock time, which returns (year - 1900), which we properly convert to
234 * the full 4-digit year. There is a possibility that applications using
235 * libpng are not passing 4-digit years into the png_convert_to_rfc_1123()
236 * function, or that they are incorrectly passing only a 2-digit year
237 * instead of "year - 1900" into the png_convert_from_struct_tm() function,
238 * but this is not under our control. The libpng documentation has always
239 * stated that it works with 4-digit years, and the APIs have been
240 * documented as such.
242 * The tIME chunk itself is also Y2K compliant. It uses a 2-byte unsigned
243 * integer to hold the year, and can hold years as large as 65535.
245 * zlib, upon which libpng depends, is also Y2K compliant. It contains
246 * no date-related code.
248 * Glenn Randers-Pehrson
250 * PNG Development Group
256 /* This is not the place to learn how to use libpng. The file libpng.txt
257 * describes how to use libpng, and the file example.c summarizes it
258 * with some code on which to build. This file is useful for looking
259 * at the actual function definitions and structure components.
262 /* Version information for png.h - this should match the version in png.c */
263 #define PNG_LIBPNG_VER_STRING "1.0.9"
265 #define PNG_LIBPNG_VER_SONUM 2
266 #define PNG_LIBPNG_VER_DLLNUM %DLLNUM%
268 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
269 #define PNG_LIBPNG_VER_MAJOR 1
270 #define PNG_LIBPNG_VER_MINOR 0
271 #define PNG_LIBPNG_VER_RELEASE 9
272 /* This should match the numeric part of the final component of
273 * PNG_LIBPNG_VER_STRING, omitting any leading zero: */
275 #define PNG_LIBPNG_VER_BUILD 0
277 #define PNG_LIBPNG_BUILD_ALPHA 1
278 #define PNG_LIBPNG_BUILD_BETA 2
279 #define PNG_LIBPNG_BUILD_RC 3
280 #define PNG_LIBPNG_BUILD_STABLE 4
281 #define PNG_LIBPNG_BUILD_TYPEMASK 7
282 #define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with STABLE only */
283 #define PNG_LIBPNG_BUILD_TYPE 4
285 /* Careful here. At one time, Guy wanted to use 082, but that would be octal.
286 * We must not include leading zeros.
287 * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only
288 * version 1.0.0 was mis-numbered 100 instead of 10000). From
289 * version 1.0.1 it's xxyyzz, where x=major, y=minor, z=release */
290 #define PNG_LIBPNG_VER 10009 /* 1.0.9 */
292 #ifndef PNG_VERSION_INFO_ONLY
294 /* include the compression library's header */
297 /* include all user configurable info, including optional assembler routines */
300 /* Inhibit C++ name-mangling for libpng functions but not for system calls. */
303 #endif /* __cplusplus */
305 /* This file is arranged in several sections. The first section contains
306 * structure and type definitions. The second section contains the external
307 * library functions, while the third has the internal library functions,
308 * which applications aren't expected to use directly.
311 /* variables declared in png.c - only it needs to define PNG_NO_EXTERN */
312 #if !defined(PNG_NO_EXTERN) || defined(PNG_ALWAYS_EXTERN)
313 /* Version information for C files, stored in png.c. This had better match
316 #ifdef PNG_USE_GLOBAL_ARRAYS
317 PNG_EXPORT_VAR (const char) png_libpng_ver[18];
318 /* need room for 99.99.99beta99z*/
320 #define png_libpng_ver png_get_header_ver(NULL)
323 #ifdef PNG_USE_GLOBAL_ARRAYS
324 /* This was removed in version 1.0.5c */
325 /* Structures to facilitate easy interlacing. See png.c for more details */
326 PNG_EXPORT_VAR (const int FARDATA) png_pass_start[7];
327 PNG_EXPORT_VAR (const int FARDATA) png_pass_inc[7];
328 PNG_EXPORT_VAR (const int FARDATA) png_pass_ystart[7];
329 PNG_EXPORT_VAR (const int FARDATA) png_pass_yinc[7];
330 PNG_EXPORT_VAR (const int FARDATA) png_pass_mask[7];
331 PNG_EXPORT_VAR (const int FARDATA) png_pass_dsp_mask[7];
332 #ifdef PNG_HAVE_ASSEMBLER_COMBINE_ROW
333 PNG_EXPORT_VAR (const int FARDATA) png_pass_width[7];
335 /* This isn't currently used. If you need it, see png.c for more details.
336 PNG_EXPORT_VAR (const int FARDATA) png_pass_height[7];
340 #endif /* PNG_NO_EXTERN */
342 /* Three color definitions. The order of the red, green, and blue, (and the
343 * exact size) is not important, although the size of the fields need to
344 * be png_byte or png_uint_16 (as defined below).
346 typedef struct png_color_struct
352 typedef png_color FAR * png_colorp;
353 typedef png_color FAR * FAR * png_colorpp;
355 typedef struct png_color_16_struct
357 png_byte index; /* used for palette files */
358 png_uint_16 red; /* for use in red green blue files */
361 png_uint_16 gray; /* for use in grayscale files */
363 typedef png_color_16 FAR * png_color_16p;
364 typedef png_color_16 FAR * FAR * png_color_16pp;
366 typedef struct png_color_8_struct
368 png_byte red; /* for use in red green blue files */
371 png_byte gray; /* for use in grayscale files */
372 png_byte alpha; /* for alpha channel files */
374 typedef png_color_8 FAR * png_color_8p;
375 typedef png_color_8 FAR * FAR * png_color_8pp;
378 * The following two structures are used for the in-core representation
381 typedef struct png_sPLT_entry_struct
387 png_uint_16 frequency;
389 typedef png_sPLT_entry FAR * png_sPLT_entryp;
390 typedef png_sPLT_entry FAR * FAR * png_sPLT_entrypp;
392 /* When the depth of the sPLT palette is 8 bits, the color and alpha samples
393 * occupy the LSB of their respective members, and the MSB of each member
394 * is zero-filled. The frequency member always occupies the full 16 bits.
397 typedef struct png_sPLT_struct
399 png_charp name; /* palette name */
400 png_byte depth; /* depth of palette samples */
401 png_sPLT_entryp entries; /* palette entries */
402 png_int_32 nentries; /* number of palette entries */
404 typedef png_sPLT_t FAR * png_sPLT_tp;
405 typedef png_sPLT_t FAR * FAR * png_sPLT_tpp;
407 #ifdef PNG_TEXT_SUPPORTED
408 /* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,
409 * and whether that contents is compressed or not. The "key" field
410 * points to a regular zero-terminated C string. The "text", "lang", and
411 * "lang_key" fields can be regular C strings, empty strings, or NULL pointers.
412 * However, the * structure returned by png_get_text() will always contain
413 * regular zero-terminated C strings (possibly empty), never NULL pointers,
414 * so they can be safely used in printf() and other string-handling functions.
416 typedef struct png_text_struct
418 int compression; /* compression value:
423 png_charp key; /* keyword, 1-79 character description of "text" */
424 png_charp text; /* comment, may be an empty string (ie "")
426 png_size_t text_length; /* length of the text string */
427 #ifdef PNG_iTXt_SUPPORTED
428 png_size_t itxt_length; /* length of the itxt string */
429 png_charp lang; /* language code, 0-79 characters
431 png_charp lang_key; /* keyword translated UTF-8 string, 0 or more
432 chars or a NULL pointer */
435 typedef png_text FAR * png_textp;
436 typedef png_text FAR * FAR * png_textpp;
439 /* Supported compression types for text in PNG files (tEXt, and zTXt).
440 * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */
441 #define PNG_TEXT_COMPRESSION_NONE_WR -3
442 #define PNG_TEXT_COMPRESSION_zTXt_WR -2
443 #define PNG_TEXT_COMPRESSION_NONE -1
444 #define PNG_TEXT_COMPRESSION_zTXt 0
445 #define PNG_ITXT_COMPRESSION_NONE 1
446 #define PNG_ITXT_COMPRESSION_zTXt 2
447 #define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */
449 /* png_time is a way to hold the time in an machine independent way.
450 * Two conversions are provided, both from time_t and struct tm. There
451 * is no portable way to convert to either of these structures, as far
452 * as I know. If you know of a portable way, send it to me. As a side
453 * note - PNG has always been Year 2000 compliant!
455 typedef struct png_time_struct
457 png_uint_16 year; /* full year, as in, 1995 */
458 png_byte month; /* month of year, 1 - 12 */
459 png_byte day; /* day of month, 1 - 31 */
460 png_byte hour; /* hour of day, 0 - 23 */
461 png_byte minute; /* minute of hour, 0 - 59 */
462 png_byte second; /* second of minute, 0 - 60 (for leap seconds) */
464 typedef png_time FAR * png_timep;
465 typedef png_time FAR * FAR * png_timepp;
467 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
468 /* png_unknown_chunk is a structure to hold queued chunks for which there is
469 * no specific support. The idea is that we can use this to queue
470 * up private chunks for output even though the library doesn't actually
471 * know about their semantics.
473 typedef struct png_unknown_chunk_t
479 /* libpng-using applications should NOT directly modify this byte. */
480 png_byte location; /* mode of operation at read time */
483 typedef png_unknown_chunk FAR * png_unknown_chunkp;
484 typedef png_unknown_chunk FAR * FAR * png_unknown_chunkpp;
487 /* png_info is a structure that holds the information in a PNG file so
488 * that the application can find out the characteristics of the image.
489 * If you are reading the file, this structure will tell you what is
490 * in the PNG file. If you are writing the file, fill in the information
491 * you want to put into the PNG file, then call png_write_info().
492 * The names chosen should be very close to the PNG specification, so
493 * consult that document for information about the meaning of each field.
495 * With libpng < 0.95, it was only possible to directly set and read the
496 * the values in the png_info_struct, which meant that the contents and
497 * order of the values had to remain fixed. With libpng 0.95 and later,
498 * however, there are now functions that abstract the contents of
499 * png_info_struct from the application, so this makes it easier to use
500 * libpng with dynamic libraries, and even makes it possible to use
501 * libraries that don't have all of the libpng ancillary chunk-handing
504 * In any case, the order of the parameters in png_info_struct should NOT
505 * be changed for as long as possible to keep compatibility with applications
506 * that use the old direct-access method with png_info_struct.
508 * The following members may have allocated storage attached that should be
509 * cleaned up before the structure is discarded: palette, trans, text,
510 * pcal_purpose, pcal_units, pcal_params, hist, iccp_name, iccp_profile,
511 * splt_palettes, scal_unit, row_pointers, and unknowns. By default, these
512 * are automatically freed when the info structure is deallocated, if they were
513 * allocated internally by libpng. This behavior can be changed by means
514 * of the png_data_freer() function.
516 * More allocation details: all the chunk-reading functions that
517 * change these members go through the corresponding png_set_*
518 * functions. A function to clear these members is available: see
519 * png_free_data(). The png_set_* functions do not depend on being
520 * able to point info structure members to any of the storage they are
521 * passed (they make their own copies), EXCEPT that the png_set_text
522 * functions use the same storage passed to them in the text_ptr or
523 * itxt_ptr structure argument, and the png_set_rows and png_set_unknowns
524 * functions do not make their own copies.
526 typedef struct png_info_struct
528 /* the following are necessary for every PNG file */
529 png_uint_32 width; /* width of image in pixels (from IHDR) */
530 png_uint_32 height; /* height of image in pixels (from IHDR) */
531 png_uint_32 valid; /* valid chunk data (see PNG_INFO_ below) */
532 png_uint_32 rowbytes; /* bytes needed to hold an untransformed row */
533 png_colorp palette; /* array of color values (valid & PNG_INFO_PLTE) */
534 png_uint_16 num_palette; /* number of color entries in "palette" (PLTE) */
535 png_uint_16 num_trans; /* number of transparent palette color (tRNS) */
536 png_byte bit_depth; /* 1, 2, 4, 8, or 16 bits/channel (from IHDR) */
537 png_byte color_type; /* see PNG_COLOR_TYPE_ below (from IHDR) */
538 /* The following three should have been named *_method not *_type */
539 png_byte compression_type; /* must be PNG_COMPRESSION_TYPE_BASE (IHDR) */
540 png_byte filter_type; /* must be PNG_FILTER_TYPE_BASE (from IHDR) */
541 png_byte interlace_type; /* One of PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
543 /* The following is informational only on read, and not used on writes. */
544 png_byte channels; /* number of data channels per pixel (1, 2, 3, 4)*/
545 png_byte pixel_depth; /* number of bits per pixel */
546 png_byte spare_byte; /* to align the data, and for future use */
547 png_byte signature[8]; /* magic bytes read by libpng from start of file */
549 /* The rest of the data is optional. If you are reading, check the
550 * valid field to see if the information in these are valid. If you
551 * are writing, set the valid field to those chunks you want written,
552 * and initialize the appropriate fields below.
555 #if defined(PNG_gAMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
556 /* The gAMA chunk describes the gamma characteristics of the system
557 * on which the image was created, normally in the range [1.0, 2.5].
558 * Data is valid if (valid & PNG_INFO_gAMA) is non-zero.
560 float gamma; /* gamma value of image, if (valid & PNG_INFO_gAMA) */
563 #if defined(PNG_sRGB_SUPPORTED)
565 /* Data valid if (valid & PNG_INFO_sRGB) non-zero. */
566 png_byte srgb_intent; /* sRGB rendering intent [0, 1, 2, or 3] */
569 #if defined(PNG_TEXT_SUPPORTED)
570 /* The tEXt, and zTXt chunks contain human-readable textual data in
571 * uncompressed, compressed, and optionally compressed forms, respectively.
572 * The data in "text" is an array of pointers to uncompressed,
573 * null-terminated C strings. Each chunk has a keyword that describes the
574 * textual data contained in that chunk. Keywords are not required to be
575 * unique, and the text string may be empty. Any number of text chunks may
578 int num_text; /* number of comments read/to write */
579 int max_text; /* current size of text array */
580 png_textp text; /* array of comments read/to write */
581 #endif /* PNG_TEXT_SUPPORTED */
583 #if defined(PNG_tIME_SUPPORTED)
584 /* The tIME chunk holds the last time the displayed image data was
585 * modified. See the png_time struct for the contents of this struct.
590 #if defined(PNG_sBIT_SUPPORTED)
591 /* The sBIT chunk specifies the number of significant high-order bits
592 * in the pixel data. Values are in the range [1, bit_depth], and are
593 * only specified for the channels in the pixel data. The contents of
594 * the low-order bits is not specified. Data is valid if
595 * (valid & PNG_INFO_sBIT) is non-zero.
597 png_color_8 sig_bit; /* significant bits in color channels */
600 #if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_EXPAND_SUPPORTED) || \
601 defined(PNG_READ_BACKGROUND_SUPPORTED)
602 /* The tRNS chunk supplies transparency data for paletted images and
603 * other image types that don't need a full alpha channel. There are
604 * "num_trans" transparency values for a paletted image, stored in the
605 * same order as the palette colors, starting from index 0. Values
606 * for the data are in the range [0, 255], ranging from fully transparent
607 * to fully opaque, respectively. For non-paletted images, there is a
608 * single color specified that should be treated as fully transparent.
609 * Data is valid if (valid & PNG_INFO_tRNS) is non-zero.
611 png_bytep trans; /* transparent values for paletted image */
612 png_color_16 trans_values; /* transparent color for non-palette image */
615 #if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
616 /* The bKGD chunk gives the suggested image background color if the
617 * display program does not have its own background color and the image
618 * is needs to composited onto a background before display. The colors
619 * in "background" are normally in the same color space/depth as the
620 * pixel data. Data is valid if (valid & PNG_INFO_bKGD) is non-zero.
622 png_color_16 background;
625 #if defined(PNG_oFFs_SUPPORTED)
626 /* The oFFs chunk gives the offset in "offset_unit_type" units rightwards
627 * and downwards from the top-left corner of the display, page, or other
628 * application-specific co-ordinate space. See the PNG_OFFSET_ defines
629 * below for the unit types. Valid if (valid & PNG_INFO_oFFs) non-zero.
631 png_int_32 x_offset; /* x offset on page */
632 png_int_32 y_offset; /* y offset on page */
633 png_byte offset_unit_type; /* offset units type */
636 #if defined(PNG_pHYs_SUPPORTED)
637 /* The pHYs chunk gives the physical pixel density of the image for
638 * display or printing in "phys_unit_type" units (see PNG_RESOLUTION_
639 * defines below). Data is valid if (valid & PNG_INFO_pHYs) is non-zero.
641 png_uint_32 x_pixels_per_unit; /* horizontal pixel density */
642 png_uint_32 y_pixels_per_unit; /* vertical pixel density */
643 png_byte phys_unit_type; /* resolution type (see PNG_RESOLUTION_ below) */
646 #if defined(PNG_hIST_SUPPORTED)
647 /* The hIST chunk contains the relative frequency or importance of the
648 * various palette entries, so that a viewer can intelligently select a
649 * reduced-color palette, if required. Data is an array of "num_palette"
650 * values in the range [0,65535]. Data valid if (valid & PNG_INFO_hIST)
656 #ifdef PNG_cHRM_SUPPORTED
657 /* The cHRM chunk describes the CIE color characteristics of the monitor
658 * on which the PNG was created. This data allows the viewer to do gamut
659 * mapping of the input image to ensure that the viewer sees the same
660 * colors in the image as the creator. Values are in the range
661 * [0.0, 0.8]. Data valid if (valid & PNG_INFO_cHRM) non-zero.
663 #ifdef PNG_FLOATING_POINT_SUPPORTED
675 #if defined(PNG_pCAL_SUPPORTED)
676 /* The pCAL chunk describes a transformation between the stored pixel
677 * values and original physical data values used to create the image.
678 * The integer range [0, 2^bit_depth - 1] maps to the floating-point
679 * range given by [pcal_X0, pcal_X1], and are further transformed by a
680 * (possibly non-linear) transformation function given by "pcal_type"
681 * and "pcal_params" into "pcal_units". Please see the PNG_EQUATION_
682 * defines below, and the PNG-Group's PNG extensions document for a
683 * complete description of the transformations and how they should be
684 * implemented, and for a description of the ASCII parameter strings.
685 * Data values are valid if (valid & PNG_INFO_pCAL) non-zero.
687 png_charp pcal_purpose; /* pCAL chunk description string */
688 png_int_32 pcal_X0; /* minimum value */
689 png_int_32 pcal_X1; /* maximum value */
690 png_charp pcal_units; /* Latin-1 string giving physical units */
691 png_charpp pcal_params; /* ASCII strings containing parameter values */
692 png_byte pcal_type; /* equation type (see PNG_EQUATION_ below) */
693 png_byte pcal_nparams; /* number of parameters given in pcal_params */
696 #ifdef PNG_FREE_ME_SUPPORTED
697 png_uint_32 free_me; /* flags items libpng is responsible for freeing */
700 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
701 /* storage for unknown chunks that the library doesn't recognize. */
702 png_unknown_chunkp unknown_chunks;
703 png_size_t unknown_chunks_num;
706 #if defined(PNG_iCCP_SUPPORTED)
707 /* iCCP chunk data. */
708 png_charp iccp_name; /* profile name */
709 png_charp iccp_profile; /* International Color Consortium profile data */
710 /* Note to maintainer: should be png_bytep */
711 png_uint_32 iccp_proflen; /* ICC profile data length */
712 png_byte iccp_compression; /* Always zero */
715 #if defined(PNG_sPLT_SUPPORTED)
716 /* data on sPLT chunks (there may be more than one). */
717 png_sPLT_tp splt_palettes;
718 png_uint_32 splt_palettes_num;
721 #if defined(PNG_sCAL_SUPPORTED)
722 /* The sCAL chunk describes the actual physical dimensions of the
723 * subject matter of the graphic. The chunk contains a unit specification
724 * a byte value, and two ASCII strings representing floating-point
725 * values. The values are width and height corresponsing to one pixel
726 * in the image. This external representation is converted to double
727 * here. Data values are valid if (valid & PNG_INFO_sCAL) is non-zero.
729 png_byte scal_unit; /* unit of physical scale */
730 #ifdef PNG_FLOATING_POINT_SUPPORTED
731 double scal_pixel_width; /* width of one pixel */
732 double scal_pixel_height; /* height of one pixel */
734 #ifdef PNG_FIXED_POINT_SUPPORTED
735 png_charp scal_s_width; /* string containing height */
736 png_charp scal_s_height; /* string containing width */
740 #if defined(PNG_INFO_IMAGE_SUPPORTED)
741 /* Memory has been allocated if (valid & PNG_ALLOCATED_INFO_ROWS) non-zero */
742 /* Data valid if (valid & PNG_INFO_IDAT) non-zero */
743 png_bytepp row_pointers; /* the image bits */
746 #if defined(PNG_FIXED_POINT_SUPPORTED) && defined(PNG_gAMA_SUPPORTED)
747 png_fixed_point int_gamma; /* gamma of image, if (valid & PNG_INFO_gAMA) */
750 #if defined(PNG_cHRM_SUPPORTED) && defined(PNG_FIXED_POINT_SUPPORTED)
751 png_fixed_point int_x_white;
752 png_fixed_point int_y_white;
753 png_fixed_point int_x_red;
754 png_fixed_point int_y_red;
755 png_fixed_point int_x_green;
756 png_fixed_point int_y_green;
757 png_fixed_point int_x_blue;
758 png_fixed_point int_y_blue;
763 typedef png_info FAR * png_infop;
764 typedef png_info FAR * FAR * png_infopp;
766 /* Maximum positive integer used in PNG is (2^31)-1 */
767 #define PNG_MAX_UINT ((png_uint_32)0x7fffffffL)
769 /* These describe the color_type field in png_info. */
770 /* color type masks */
771 #define PNG_COLOR_MASK_PALETTE 1
772 #define PNG_COLOR_MASK_COLOR 2
773 #define PNG_COLOR_MASK_ALPHA 4
775 /* color types. Note that not all combinations are legal */
776 #define PNG_COLOR_TYPE_GRAY 0
777 #define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
778 #define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR)
779 #define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
780 #define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
782 #define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA
783 #define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA
785 /* This is for compression type. PNG 1.0-1.2 only define the single type. */
786 #define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */
787 #define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE
789 /* This is for filter type. PNG 1.0-1.2 only define the single type. */
790 #define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */
791 #define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */
792 #define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE
794 /* These are for the interlacing type. These values should NOT be changed. */
795 #define PNG_INTERLACE_NONE 0 /* Non-interlaced image */
796 #define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */
797 #define PNG_INTERLACE_LAST 2 /* Not a valid value */
799 /* These are for the oFFs chunk. These values should NOT be changed. */
800 #define PNG_OFFSET_PIXEL 0 /* Offset in pixels */
801 #define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */
802 #define PNG_OFFSET_LAST 2 /* Not a valid value */
804 /* These are for the pCAL chunk. These values should NOT be changed. */
805 #define PNG_EQUATION_LINEAR 0 /* Linear transformation */
806 #define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */
807 #define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */
808 #define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */
809 #define PNG_EQUATION_LAST 4 /* Not a valid value */
811 /* These are for the sCAL chunk. These values should NOT be changed. */
812 #define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */
813 #define PNG_SCALE_METER 1 /* meters per pixel */
814 #define PNG_SCALE_RADIAN 2 /* radians per pixel */
815 #define PNG_SCALE_LAST 3 /* Not a valid value */
817 /* These are for the pHYs chunk. These values should NOT be changed. */
818 #define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */
819 #define PNG_RESOLUTION_METER 1 /* pixels/meter */
820 #define PNG_RESOLUTION_LAST 2 /* Not a valid value */
822 /* These are for the sRGB chunk. These values should NOT be changed. */
823 #define PNG_sRGB_INTENT_PERCEPTUAL 0
824 #define PNG_sRGB_INTENT_RELATIVE 1
825 #define PNG_sRGB_INTENT_SATURATION 2
826 #define PNG_sRGB_INTENT_ABSOLUTE 3
827 #define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */
829 /* This is for text chunks */
830 #define PNG_KEYWORD_MAX_LENGTH 79
832 /* Maximum number of entries in PLTE/sPLT/tRNS arrays */
833 #define PNG_MAX_PALETTE_LENGTH 256
835 /* These determine if an ancillary chunk's data has been successfully read
836 * from the PNG header, or if the application has filled in the corresponding
837 * data in the info_struct to be written into the output file. The values
838 * of the PNG_INFO_<chunk> defines should NOT be changed.
840 #define PNG_INFO_gAMA 0x0001
841 #define PNG_INFO_sBIT 0x0002
842 #define PNG_INFO_cHRM 0x0004
843 #define PNG_INFO_PLTE 0x0008
844 #define PNG_INFO_tRNS 0x0010
845 #define PNG_INFO_bKGD 0x0020
846 #define PNG_INFO_hIST 0x0040
847 #define PNG_INFO_pHYs 0x0080
848 #define PNG_INFO_oFFs 0x0100
849 #define PNG_INFO_tIME 0x0200
850 #define PNG_INFO_pCAL 0x0400
851 #define PNG_INFO_sRGB 0x0800 /* GR-P, 0.96a */
852 #define PNG_INFO_iCCP 0x1000 /* ESR, 1.0.6 */
853 #define PNG_INFO_sPLT 0x2000 /* ESR, 1.0.6 */
854 #define PNG_INFO_sCAL 0x4000 /* ESR, 1.0.6 */
855 #define PNG_INFO_IDAT 0x8000L /* ESR, 1.0.6 */
857 /* This is used for the transformation routines, as some of them
858 * change these values for the row. It also should enable using
859 * the routines for other purposes.
861 typedef struct png_row_info_struct
863 png_uint_32 width; /* width of row */
864 png_uint_32 rowbytes; /* number of bytes in row */
865 png_byte color_type; /* color type of row */
866 png_byte bit_depth; /* bit depth of row */
867 png_byte channels; /* number of channels (1, 2, 3, or 4) */
868 png_byte pixel_depth; /* bits per pixel (depth * channels) */
871 typedef png_row_info FAR * png_row_infop;
872 typedef png_row_info FAR * FAR * png_row_infopp;
874 /* These are the function types for the I/O functions and for the functions
875 * that allow the user to override the default I/O functions with his or her
876 * own. The png_error_ptr type should match that of user-supplied warning
877 * and error functions, while the png_rw_ptr type should match that of the
878 * user read/write data functions.
880 typedef struct png_struct_def png_struct;
881 typedef png_struct FAR * png_structp;
883 typedef void (PNGAPI *png_error_ptr) PNGARG((png_structp, png_const_charp));
884 typedef void (PNGAPI *png_rw_ptr) PNGARG((png_structp, png_bytep, png_size_t));
885 typedef void (PNGAPI *png_flush_ptr) PNGARG((png_structp));
886 typedef void (PNGAPI *png_read_status_ptr) PNGARG((png_structp, png_uint_32,
888 typedef void (PNGAPI *png_write_status_ptr) PNGARG((png_structp, png_uint_32,
891 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
892 typedef void (PNGAPI *png_progressive_info_ptr) PNGARG((png_structp, png_infop));
893 typedef void (PNGAPI *png_progressive_end_ptr) PNGARG((png_structp, png_infop));
894 typedef void (PNGAPI *png_progressive_row_ptr) PNGARG((png_structp, png_bytep,
898 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
899 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
900 defined(PNG_LEGACY_SUPPORTED)
901 typedef void (PNGAPI *png_user_transform_ptr) PNGARG((png_structp,
902 png_row_infop, png_bytep));
905 #if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
906 typedef int (PNGAPI *png_user_chunk_ptr) PNGARG((png_structp, png_unknown_chunkp));
908 #if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
909 typedef void (PNGAPI *png_unknown_chunk_ptr) PNGARG((png_structp));
912 /* Transform masks for the high-level interface */
913 #define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */
914 #define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */
915 #define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */
916 #define PNG_TRANSFORM_PACKING 0x0004 /* read and write */
917 #define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */
918 #define PNG_TRANSFORM_EXPAND 0x0010 /* read only */
919 #define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */
920 #define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */
921 #define PNG_TRANSFORM_BGR 0x0080 /* read and write */
922 #define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */
923 #define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */
924 #define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */
925 #define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* WRITE only */
927 /* Flags for MNG supported features */
928 #define PNG_FLAG_MNG_EMPTY_PLTE 0x01
929 #define PNG_FLAG_MNG_FILTER_64 0x04
930 #define PNG_ALL_MNG_FEATURES 0x05
932 typedef png_voidp (*png_malloc_ptr) PNGARG((png_structp, png_size_t));
933 typedef void (*png_free_ptr) PNGARG((png_structp, png_voidp));
935 /* The structure that holds the information to read and write PNG files.
936 * The only people who need to care about what is inside of this are the
937 * people who will be modifying the library for their own special needs.
938 * It should NOT be accessed directly by an application, except to store
942 struct png_struct_def
944 #ifdef PNG_SETJMP_SUPPORTED
945 jmp_buf jmpbuf; /* used in png_error */
947 png_error_ptr error_fn; /* function for printing errors and aborting */
948 png_error_ptr warning_fn; /* function for printing warnings */
949 png_voidp error_ptr; /* user supplied struct for error functions */
950 png_rw_ptr write_data_fn; /* function for writing output data */
951 png_rw_ptr read_data_fn; /* function for reading input data */
952 png_voidp io_ptr; /* ptr to application struct for I/O functions*/
954 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
955 png_user_transform_ptr read_user_transform_fn; /* user read transform */
958 #if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
959 png_user_transform_ptr write_user_transform_fn; /* user write transform */
962 /* These were added in libpng-1.0.2 */
963 #if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
964 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
965 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
966 png_voidp user_transform_ptr; /* user supplied struct for user transform */
967 png_byte user_transform_depth; /* bit depth of user transformed pixels */
968 png_byte user_transform_channels; /* channels in user transformed pixels */
972 png_uint_32 mode; /* tells us where we are in the PNG file */
973 png_uint_32 flags; /* flags indicating various things to libpng */
974 png_uint_32 transformations; /* which transformations to perform */
976 z_stream zstream; /* pointer to decompression structure (below) */
977 png_bytep zbuf; /* buffer for zlib */
978 png_size_t zbuf_size; /* size of zbuf */
979 int zlib_level; /* holds zlib compression level */
980 int zlib_method; /* holds zlib compression method */
981 int zlib_window_bits; /* holds zlib compression window bits */
982 int zlib_mem_level; /* holds zlib compression memory level */
983 int zlib_strategy; /* holds zlib compression strategy */
985 png_uint_32 width; /* width of image in pixels */
986 png_uint_32 height; /* height of image in pixels */
987 png_uint_32 num_rows; /* number of rows in current pass */
988 png_uint_32 usr_width; /* width of row at start of write */
989 png_uint_32 rowbytes; /* size of row in bytes */
990 png_uint_32 irowbytes; /* size of current interlaced row in bytes */
991 png_uint_32 iwidth; /* width of current interlaced row in pixels */
992 png_uint_32 row_number; /* current row in interlace pass */
993 png_bytep prev_row; /* buffer to save previous (unfiltered) row */
994 png_bytep row_buf; /* buffer to save current (unfiltered) row */
995 png_bytep sub_row; /* buffer to save "sub" row when filtering */
996 png_bytep up_row; /* buffer to save "up" row when filtering */
997 png_bytep avg_row; /* buffer to save "avg" row when filtering */
998 png_bytep paeth_row; /* buffer to save "Paeth" row when filtering */
999 png_row_info row_info; /* used for transformation routines */
1001 png_uint_32 idat_size; /* current IDAT size for read */
1002 png_uint_32 crc; /* current chunk CRC value */
1003 png_colorp palette; /* palette from the input file */
1004 png_uint_16 num_palette; /* number of color entries in palette */
1005 png_uint_16 num_trans; /* number of transparency values */
1006 png_byte chunk_name[5]; /* null-terminated name of current chunk */
1007 png_byte compression; /* file compression type (always 0) */
1008 png_byte filter; /* file filter type (always 0) */
1009 png_byte interlaced; /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
1010 png_byte pass; /* current interlace pass (0 - 6) */
1011 png_byte do_filter; /* row filter flags (see PNG_FILTER_ below ) */
1012 png_byte color_type; /* color type of file */
1013 png_byte bit_depth; /* bit depth of file */
1014 png_byte usr_bit_depth; /* bit depth of users row */
1015 png_byte pixel_depth; /* number of bits per pixel */
1016 png_byte channels; /* number of channels in file */
1017 png_byte usr_channels; /* channels at start of write */
1018 png_byte sig_bytes; /* magic bytes read/written from start of file */
1020 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
1021 #ifdef PNG_LEGACY_SUPPORTED
1022 png_byte filler; /* filler byte for pixel expansion */
1024 png_uint_16 filler; /* filler bytes for pixel expansion */
1028 #if defined(PNG_READ_bKGD_SUPPORTED)
1029 png_byte background_gamma_type;
1030 # ifdef PNG_FLOATING_POINT_SUPPORTED
1031 float background_gamma;
1033 png_color_16 background; /* background color in screen gamma space */
1034 # if defined(PNG_READ_GAMMA_SUPPORTED)
1035 png_color_16 background_1; /* background normalized to gamma 1.0 */
1036 # endif /* PNG_READ_GAMMA && PNG_READ_bKGD_SUPPORTED */
1037 #endif /* PNG_READ_bKGD_SUPPORTED */
1039 #if defined(PNG_WRITE_FLUSH_SUPPORTED)
1040 png_flush_ptr output_flush_fn;/* Function for flushing output */
1041 png_uint_32 flush_dist; /* how many rows apart to flush, 0 - no flush */
1042 png_uint_32 flush_rows; /* number of rows written since last flush */
1045 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1046 int gamma_shift; /* number of "insignificant" bits 16-bit gamma */
1047 #ifdef PNG_FLOATING_POINT_SUPPORTED
1048 float gamma; /* file gamma value */
1049 float screen_gamma; /* screen gamma value (display_exponent) */
1053 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1054 png_bytep gamma_table; /* gamma table for 8-bit depth files */
1055 png_bytep gamma_from_1; /* converts from 1.0 to screen */
1056 png_bytep gamma_to_1; /* converts from file to 1.0 */
1057 png_uint_16pp gamma_16_table; /* gamma table for 16-bit depth files */
1058 png_uint_16pp gamma_16_from_1; /* converts from 1.0 to screen */
1059 png_uint_16pp gamma_16_to_1; /* converts from file to 1.0 */
1062 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_sBIT_SUPPORTED)
1063 png_color_8 sig_bit; /* significant bits in each available channel */
1066 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
1067 png_color_8 shift; /* shift for significant bit tranformation */
1070 #if defined(PNG_READ_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \
1071 || defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1072 png_bytep trans; /* transparency values for paletted files */
1073 png_color_16 trans_values; /* transparency values for non-paletted files */
1076 png_read_status_ptr read_row_fn; /* called after each row is decoded */
1077 png_write_status_ptr write_row_fn; /* called after each row is encoded */
1078 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1079 png_progressive_info_ptr info_fn; /* called after header data fully read */
1080 png_progressive_row_ptr row_fn; /* called after each prog. row is decoded */
1081 png_progressive_end_ptr end_fn; /* called after image is complete */
1082 png_bytep save_buffer_ptr; /* current location in save_buffer */
1083 png_bytep save_buffer; /* buffer for previously read data */
1084 png_bytep current_buffer_ptr; /* current location in current_buffer */
1085 png_bytep current_buffer; /* buffer for recently used data */
1086 png_uint_32 push_length; /* size of current input chunk */
1087 png_uint_32 skip_length; /* bytes to skip in input data */
1088 png_size_t save_buffer_size; /* amount of data now in save_buffer */
1089 png_size_t save_buffer_max; /* total size of save_buffer */
1090 png_size_t buffer_size; /* total amount of available input data */
1091 png_size_t current_buffer_size; /* amount of data now in current_buffer */
1092 int process_mode; /* what push library is currently doing */
1093 int cur_palette; /* current push library palette index */
1095 # if defined(PNG_READ_TEXT_SUPPORTED)
1096 png_size_t current_text_size; /* current size of text input data */
1097 png_size_t current_text_left; /* how much text left to read in input */
1098 png_charp current_text; /* current text chunk buffer */
1099 png_charp current_text_ptr; /* current location in current_text */
1100 # endif /* PNG_PROGRESSIVE_READ_SUPPORTED && PNG_READ_TEXT_SUPPORTED */
1102 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
1104 #if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
1105 /* for the Borland special 64K segment handler */
1106 png_bytepp offset_table_ptr;
1107 png_bytep offset_table;
1108 png_uint_16 offset_table_number;
1109 png_uint_16 offset_table_count;
1110 png_uint_16 offset_table_count_free;
1113 #if defined(PNG_READ_DITHER_SUPPORTED)
1114 png_bytep palette_lookup; /* lookup table for dithering */
1115 png_bytep dither_index; /* index translation for palette files */
1118 #if defined(PNG_READ_DITHER_SUPPORTED) || defined(PNG_READ_hIST_SUPPORTED)
1119 png_uint_16p hist; /* histogram */
1122 #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
1123 png_byte heuristic_method; /* heuristic for row filter selection */
1124 png_byte num_prev_filters; /* number of weights for previous rows */
1125 png_bytep prev_filters; /* filter type(s) of previous row(s) */
1126 png_uint_16p filter_weights; /* weight(s) for previous line(s) */
1127 png_uint_16p inv_filter_weights; /* 1/weight(s) for previous line(s) */
1128 png_uint_16p filter_costs; /* relative filter calculation cost */
1129 png_uint_16p inv_filter_costs; /* 1/relative filter calculation cost */
1132 #if defined(PNG_TIME_RFC1123_SUPPORTED)
1133 png_charp time_buffer; /* String to hold RFC 1123 time text */
1136 #ifdef PNG_USER_MEM_SUPPORTED
1137 png_voidp mem_ptr; /* user supplied struct for mem functions */
1138 png_malloc_ptr malloc_fn; /* function for allocating memory */
1139 png_free_ptr free_fn; /* function for freeing memory */
1142 /* New members added in libpng-1.0.6 */
1144 #ifdef PNG_FREE_ME_SUPPORTED
1145 png_uint_32 free_me; /* flags items libpng is responsible for freeing */
1148 #if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
1149 png_voidp user_chunk_ptr;
1150 png_user_chunk_ptr read_user_chunk_fn; /* user read chunk handler */
1153 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
1155 png_bytep chunk_list;
1158 #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
1159 png_byte rgb_to_gray_status;
1160 png_uint_16 rgb_to_gray_red_coeff;
1161 png_uint_16 rgb_to_gray_green_coeff;
1162 png_uint_16 rgb_to_gray_blue_coeff;
1165 #if defined(PNG_MNG_FEATURES_SUPPORTED) || \
1166 defined(PNG_READ_EMPTY_PLTE_SUPPORTED) || \
1167 defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
1168 /* Note to maintainer: change this to png_uint_32 at next opportunity */
1169 png_byte mng_features_permitted;
1172 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1173 png_fixed_point int_gamma;
1176 png_byte filter_type;
1181 /* This prevents a compiler error in png_get_copyright() in png.c if png.c
1182 and png.h are both at * version 1.0.9
1184 typedef png_structp version_1_0_9;
1186 typedef png_struct FAR * FAR * png_structpp;
1188 /* Here are the function definitions most commonly used. This is not
1189 * the place to find out how to use libpng. See libpng.txt for the
1190 * full explanation, see example.c for the summary. This just provides
1191 * a simple one line description of the use of each function.
1194 /* Returns the version number of the library */
1195 extern PNG_EXPORT(png_uint_32,png_access_version_number) PNGARG((void));
1197 /* Tell lib we have already handled the first <num_bytes> magic bytes.
1198 * Handling more than 8 bytes from the beginning of the file is an error.
1200 extern PNG_EXPORT(void,png_set_sig_bytes) PNGARG((png_structp png_ptr,
1203 /* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
1204 * PNG file. Returns zero if the supplied bytes match the 8-byte PNG
1205 * signature, and non-zero otherwise. Having num_to_check == 0 or
1206 * start > 7 will always fail (ie return non-zero).
1208 extern PNG_EXPORT(int,png_sig_cmp) PNGARG((png_bytep sig, png_size_t start,
1209 png_size_t num_to_check));
1211 /* Simple signature checking function. This is the same as calling
1212 * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n).
1214 extern PNG_EXPORT(int,png_check_sig) PNGARG((png_bytep sig, int num));
1216 /* Allocate and initialize png_ptr struct for reading, and any other memory. */
1217 extern PNG_EXPORT(png_structp,png_create_read_struct)
1218 PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1219 png_error_ptr error_fn, png_error_ptr warn_fn));
1221 /* Allocate and initialize png_ptr struct for writing, and any other memory */
1222 extern PNG_EXPORT(png_structp,png_create_write_struct)
1223 PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1224 png_error_ptr error_fn, png_error_ptr warn_fn));
1226 extern PNG_EXPORT(png_uint_32,png_get_compression_buffer_size)
1227 PNGARG((png_structp png_ptr));
1229 extern PNG_EXPORT(void,png_set_compression_buffer_size)
1230 PNGARG((png_structp png_ptr, png_uint_32 size));
1232 /* Reset the compression stream */
1233 extern PNG_EXPORT(int,png_reset_zstream) PNGARG((png_structp png_ptr));
1235 #ifdef PNG_USER_MEM_SUPPORTED
1236 extern PNG_EXPORT(png_structp,png_create_read_struct_2)
1237 PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1238 png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
1239 png_malloc_ptr malloc_fn, png_free_ptr free_fn));
1240 extern PNG_EXPORT(png_structp,png_create_write_struct_2)
1241 PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1242 png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
1243 png_malloc_ptr malloc_fn, png_free_ptr free_fn));
1246 /* Write a PNG chunk - size, type, (optional) data, CRC. */
1247 extern PNG_EXPORT(void,png_write_chunk) PNGARG((png_structp png_ptr,
1248 png_bytep chunk_name, png_bytep data, png_size_t length));
1250 /* Write the start of a PNG chunk - length and chunk name. */
1251 extern PNG_EXPORT(void,png_write_chunk_start) PNGARG((png_structp png_ptr,
1252 png_bytep chunk_name, png_uint_32 length));
1254 /* Write the data of a PNG chunk started with png_write_chunk_start(). */
1255 extern PNG_EXPORT(void,png_write_chunk_data) PNGARG((png_structp png_ptr,
1256 png_bytep data, png_size_t length));
1258 /* Finish a chunk started with png_write_chunk_start() (includes CRC). */
1259 extern PNG_EXPORT(void,png_write_chunk_end) PNGARG((png_structp png_ptr));
1261 /* Allocate and initialize the info structure */
1262 extern PNG_EXPORT(png_infop,png_create_info_struct)
1263 PNGARG((png_structp png_ptr));
1265 /* Initialize the info structure (old interface - NOT DLL EXPORTED) */
1266 extern void png_info_init PNGARG((png_infop info_ptr));
1268 /* Writes all the PNG information before the image. */
1269 extern PNG_EXPORT(void,png_write_info_before_PLTE) PNGARG((png_structp png_ptr,
1270 png_infop info_ptr));
1271 extern PNG_EXPORT(void,png_write_info) PNGARG((png_structp png_ptr,
1272 png_infop info_ptr));
1274 /* read the information before the actual image data. */
1275 extern PNG_EXPORT(void,png_read_info) PNGARG((png_structp png_ptr,
1276 png_infop info_ptr));
1278 #if defined(PNG_TIME_RFC1123_SUPPORTED)
1279 extern PNG_EXPORT(png_charp,png_convert_to_rfc1123)
1280 PNGARG((png_structp png_ptr, png_timep ptime));
1283 #if !defined(_WIN32_WCE)
1284 /* "time.h" functions are not supported on WindowsCE */
1285 #if defined(PNG_WRITE_tIME_SUPPORTED)
1286 /* convert from a struct tm to png_time */
1287 extern PNG_EXPORT(void,png_convert_from_struct_tm) PNGARG((png_timep ptime,
1288 struct tm FAR * ttime));
1290 /* convert from time_t to png_time. Uses gmtime() */
1291 extern PNG_EXPORT(void,png_convert_from_time_t) PNGARG((png_timep ptime,
1293 #endif /* PNG_WRITE_tIME_SUPPORTED */
1294 #endif /* _WIN32_WCE */
1296 #if defined(PNG_READ_EXPAND_SUPPORTED)
1297 /* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
1298 extern PNG_EXPORT(void,png_set_expand) PNGARG((png_structp png_ptr));
1299 extern PNG_EXPORT(void,png_set_gray_1_2_4_to_8) PNGARG((png_structp png_ptr));
1300 extern PNG_EXPORT(void,png_set_palette_to_rgb) PNGARG((png_structp png_ptr));
1301 extern PNG_EXPORT(void,png_set_tRNS_to_alpha) PNGARG((png_structp png_ptr));
1304 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
1305 /* Use blue, green, red order for pixels. */
1306 extern PNG_EXPORT(void,png_set_bgr) PNGARG((png_structp png_ptr));
1309 #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
1310 /* Expand the grayscale to 24-bit RGB if necessary. */
1311 extern PNG_EXPORT(void,png_set_gray_to_rgb) PNGARG((png_structp png_ptr));
1314 #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
1315 /* Reduce RGB to grayscale. */
1316 #ifdef PNG_FLOATING_POINT_SUPPORTED
1317 extern PNG_EXPORT(void,png_set_rgb_to_gray) PNGARG((png_structp png_ptr,
1318 int error_action, double red, double green ));
1320 extern PNG_EXPORT(void,png_set_rgb_to_gray_fixed) PNGARG((png_structp png_ptr,
1321 int error_action, png_fixed_point red, png_fixed_point green ));
1322 extern PNG_EXPORT(png_byte,png_get_rgb_to_gray_status) PNGARG((png_structp
1326 extern PNG_EXPORT(void,png_build_grayscale_palette) PNGARG((int bit_depth,
1327 png_colorp palette));
1329 #if defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
1330 extern PNG_EXPORT(void,png_set_strip_alpha) PNGARG((png_structp png_ptr));
1333 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
1334 defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
1335 extern PNG_EXPORT(void,png_set_swap_alpha) PNGARG((png_structp png_ptr));
1338 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
1339 defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
1340 extern PNG_EXPORT(void,png_set_invert_alpha) PNGARG((png_structp png_ptr));
1343 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
1344 /* Add a filler byte to 24-bit RGB images. */
1345 extern PNG_EXPORT(void,png_set_filler) PNGARG((png_structp png_ptr,
1346 png_uint_32 filler, int flags));
1347 /* The values of the PNG_FILLER_ defines should NOT be changed */
1348 #define PNG_FILLER_BEFORE 0
1349 #define PNG_FILLER_AFTER 1
1350 #endif /* PNG_READ_FILLER_SUPPORTED || PNG_WRITE_FILLER_SUPPORTED */
1352 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
1353 /* Swap bytes in 16-bit depth files. */
1354 extern PNG_EXPORT(void,png_set_swap) PNGARG((png_structp png_ptr));
1357 #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
1358 /* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
1359 extern PNG_EXPORT(void,png_set_packing) PNGARG((png_structp png_ptr));
1362 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1363 /* Swap packing order of pixels in bytes. */
1364 extern PNG_EXPORT(void,png_set_packswap) PNGARG((png_structp png_ptr));
1367 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
1368 /* Converts files to legal bit depths. */
1369 extern PNG_EXPORT(void,png_set_shift) PNGARG((png_structp png_ptr,
1370 png_color_8p true_bits));
1373 #if defined(PNG_READ_INTERLACING_SUPPORTED) || \
1374 defined(PNG_WRITE_INTERLACING_SUPPORTED)
1375 /* Have the code handle the interlacing. Returns the number of passes. */
1376 extern PNG_EXPORT(int,png_set_interlace_handling) PNGARG((png_structp png_ptr));
1379 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
1380 /* Invert monochrome files */
1381 extern PNG_EXPORT(void,png_set_invert_mono) PNGARG((png_structp png_ptr));
1384 #if defined(PNG_READ_BACKGROUND_SUPPORTED)
1385 /* Handle alpha and tRNS by replacing with a background color. */
1386 #ifdef PNG_FLOATING_POINT_SUPPORTED
1387 extern PNG_EXPORT(void,png_set_background) PNGARG((png_structp png_ptr,
1388 png_color_16p background_color, int background_gamma_code,
1389 int need_expand, double background_gamma));
1391 #define PNG_BACKGROUND_GAMMA_UNKNOWN 0
1392 #define PNG_BACKGROUND_GAMMA_SCREEN 1
1393 #define PNG_BACKGROUND_GAMMA_FILE 2
1394 #define PNG_BACKGROUND_GAMMA_UNIQUE 3
1397 #if defined(PNG_READ_16_TO_8_SUPPORTED)
1398 /* strip the second byte of information from a 16-bit depth file. */
1399 extern PNG_EXPORT(void,png_set_strip_16) PNGARG((png_structp png_ptr));
1402 #if defined(PNG_READ_DITHER_SUPPORTED)
1403 /* Turn on dithering, and reduce the palette to the number of colors available. */
1404 extern PNG_EXPORT(void,png_set_dither) PNGARG((png_structp png_ptr,
1405 png_colorp palette, int num_palette, int maximum_colors,
1406 png_uint_16p histogram, int full_dither));
1409 #if defined(PNG_READ_GAMMA_SUPPORTED)
1410 /* Handle gamma correction. Screen_gamma=(display_exponent) */
1411 #ifdef PNG_FLOATING_POINT_SUPPORTED
1412 extern PNG_EXPORT(void,png_set_gamma) PNGARG((png_structp png_ptr,
1413 double screen_gamma, double default_file_gamma));
1417 #if defined(PNG_READ_EMPTY_PLTE_SUPPORTED) || \
1418 defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
1419 /* Permit or disallow empty PLTE (0: not permitted, 1: permitted) */
1420 /* Deprecated and will be removed. Use png_permit_mng_features() instead. */
1421 extern PNG_EXPORT(void,png_permit_empty_plte) PNGARG((png_structp png_ptr,
1422 int empty_plte_permitted));
1425 #if defined(PNG_WRITE_FLUSH_SUPPORTED)
1426 /* Set how many lines between output flushes - 0 for no flushing */
1427 extern PNG_EXPORT(void,png_set_flush) PNGARG((png_structp png_ptr, int nrows));
1428 /* Flush the current PNG output buffer */
1429 extern PNG_EXPORT(void,png_write_flush) PNGARG((png_structp png_ptr));
1432 /* optional update palette with requested transformations */
1433 extern PNG_EXPORT(void,png_start_read_image) PNGARG((png_structp png_ptr));
1435 /* optional call to update the users info structure */
1436 extern PNG_EXPORT(void,png_read_update_info) PNGARG((png_structp png_ptr,
1437 png_infop info_ptr));
1439 /* read a one or more rows of image data.*/
1440 extern PNG_EXPORT(void,png_read_rows) PNGARG((png_structp png_ptr,
1441 png_bytepp row, png_bytepp display_row, png_uint_32 num_rows));
1443 /* read a row of data.*/
1444 extern PNG_EXPORT(void,png_read_row) PNGARG((png_structp png_ptr,
1446 png_bytep display_row));
1448 /* read the whole image into memory at once. */
1449 extern PNG_EXPORT(void,png_read_image) PNGARG((png_structp png_ptr,
1452 /* write a row of image data */
1453 extern PNG_EXPORT(void,png_write_row) PNGARG((png_structp png_ptr,
1456 /* write a few rows of image data */
1457 extern PNG_EXPORT(void,png_write_rows) PNGARG((png_structp png_ptr,
1458 png_bytepp row, png_uint_32 num_rows));
1460 /* write the image data */
1461 extern PNG_EXPORT(void,png_write_image) PNGARG((png_structp png_ptr,
1464 /* writes the end of the PNG file. */
1465 extern PNG_EXPORT(void,png_write_end) PNGARG((png_structp png_ptr,
1466 png_infop info_ptr));
1468 /* read the end of the PNG file. */
1469 extern PNG_EXPORT(void,png_read_end) PNGARG((png_structp png_ptr,
1470 png_infop info_ptr));
1472 /* free any memory associated with the png_info_struct */
1473 extern PNG_EXPORT(void,png_destroy_info_struct) PNGARG((png_structp png_ptr,
1474 png_infopp info_ptr_ptr));
1476 /* free any memory associated with the png_struct and the png_info_structs */
1477 extern PNG_EXPORT(void,png_destroy_read_struct) PNGARG((png_structpp
1478 png_ptr_ptr, png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr));
1480 /* free all memory used by the read (old method - NOT DLL EXPORTED) */
1481 extern void png_read_destroy PNGARG((png_structp png_ptr, png_infop info_ptr,
1482 png_infop end_info_ptr));
1484 /* free any memory associated with the png_struct and the png_info_structs */
1485 extern PNG_EXPORT(void,png_destroy_write_struct)
1486 PNGARG((png_structpp png_ptr_ptr, png_infopp info_ptr_ptr));
1488 /* free any memory used in info_ptr struct (old method - NOT DLL EXPORTED) */
1489 extern void png_write_destroy_info PNGARG((png_infop info_ptr));
1491 /* free any memory used in png_ptr struct (old method - NOT DLL EXPORTED) */
1492 extern void png_write_destroy PNGARG((png_structp png_ptr));
1494 /* set the libpng method of handling chunk CRC errors */
1495 extern PNG_EXPORT(void,png_set_crc_action) PNGARG((png_structp png_ptr,
1496 int crit_action, int ancil_action));
1498 /* Values for png_set_crc_action() to say how to handle CRC errors in
1499 * ancillary and critical chunks, and whether to use the data contained
1500 * therein. Note that it is impossible to "discard" data in a critical
1501 * chunk. For versions prior to 0.90, the action was always error/quit,
1502 * whereas in version 0.90 and later, the action for CRC errors in ancillary
1503 * chunks is warn/discard. These values should NOT be changed.
1505 * value action:critical action:ancillary
1507 #define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */
1508 #define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */
1509 #define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */
1510 #define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */
1511 #define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */
1512 #define PNG_CRC_NO_CHANGE 5 /* use current value use current value */
1514 /* These functions give the user control over the scan-line filtering in
1515 * libpng and the compression methods used by zlib. These functions are
1516 * mainly useful for testing, as the defaults should work with most users.
1517 * Those users who are tight on memory or want faster performance at the
1518 * expense of compression can modify them. See the compression library
1519 * header file (zlib.h) for an explination of the compression functions.
1522 /* set the filtering method(s) used by libpng. Currently, the only valid
1523 * value for "method" is 0.
1525 extern PNG_EXPORT(void,png_set_filter) PNGARG((png_structp png_ptr, int method,
1528 /* Flags for png_set_filter() to say which filters to use. The flags
1529 * are chosen so that they don't conflict with real filter types
1530 * below, in case they are supplied instead of the #defined constants.
1531 * These values should NOT be changed.
1533 #define PNG_NO_FILTERS 0x00
1534 #define PNG_FILTER_NONE 0x08
1535 #define PNG_FILTER_SUB 0x10
1536 #define PNG_FILTER_UP 0x20
1537 #define PNG_FILTER_AVG 0x40
1538 #define PNG_FILTER_PAETH 0x80
1539 #define PNG_ALL_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP | \
1540 PNG_FILTER_AVG | PNG_FILTER_PAETH)
1542 /* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
1543 * These defines should NOT be changed.
1545 #define PNG_FILTER_VALUE_NONE 0
1546 #define PNG_FILTER_VALUE_SUB 1
1547 #define PNG_FILTER_VALUE_UP 2
1548 #define PNG_FILTER_VALUE_AVG 3
1549 #define PNG_FILTER_VALUE_PAETH 4
1550 #define PNG_FILTER_VALUE_LAST 5
1552 #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) /* EXPERIMENTAL */
1553 /* The "heuristic_method" is given by one of the PNG_FILTER_HEURISTIC_
1554 * defines, either the default (minimum-sum-of-absolute-differences), or
1555 * the experimental method (weighted-minimum-sum-of-absolute-differences).
1557 * Weights are factors >= 1.0, indicating how important it is to keep the
1558 * filter type consistent between rows. Larger numbers mean the current
1559 * filter is that many times as likely to be the same as the "num_weights"
1560 * previous filters. This is cumulative for each previous row with a weight.
1561 * There needs to be "num_weights" values in "filter_weights", or it can be
1562 * NULL if the weights aren't being specified. Weights have no influence on
1563 * the selection of the first row filter. Well chosen weights can (in theory)
1564 * improve the compression for a given image.
1566 * Costs are factors >= 1.0 indicating the relative decoding costs of a
1567 * filter type. Higher costs indicate more decoding expense, and are
1568 * therefore less likely to be selected over a filter with lower computational
1569 * costs. There needs to be a value in "filter_costs" for each valid filter
1570 * type (given by PNG_FILTER_VALUE_LAST), or it can be NULL if you aren't
1571 * setting the costs. Costs try to improve the speed of decompression without
1572 * unduly increasing the compressed image size.
1574 * A negative weight or cost indicates the default value is to be used, and
1575 * values in the range [0.0, 1.0) indicate the value is to remain unchanged.
1576 * The default values for both weights and costs are currently 1.0, but may
1577 * change if good general weighting/cost heuristics can be found. If both
1578 * the weights and costs are set to 1.0, this degenerates the WEIGHTED method
1579 * to the UNWEIGHTED method, but with added encoding time/computation.
1581 #ifdef PNG_FLOATING_POINT_SUPPORTED
1582 extern PNG_EXPORT(void,png_set_filter_heuristics) PNGARG((png_structp png_ptr,
1583 int heuristic_method, int num_weights, png_doublep filter_weights,
1584 png_doublep filter_costs));
1586 #endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
1588 /* Heuristic used for row filter selection. These defines should NOT be
1591 #define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */
1592 #define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */
1593 #define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */
1594 #define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */
1596 /* Set the library compression level. Currently, valid values range from
1597 * 0 - 9, corresponding directly to the zlib compression levels 0 - 9
1598 * (0 - no compression, 9 - "maximal" compression). Note that tests have
1599 * shown that zlib compression levels 3-6 usually perform as well as level 9
1600 * for PNG images, and do considerably fewer caclulations. In the future,
1601 * these values may not correspond directly to the zlib compression levels.
1603 extern PNG_EXPORT(void,png_set_compression_level) PNGARG((png_structp png_ptr,
1606 extern PNG_EXPORT(void,png_set_compression_mem_level)
1607 PNGARG((png_structp png_ptr, int mem_level));
1609 extern PNG_EXPORT(void,png_set_compression_strategy)
1610 PNGARG((png_structp png_ptr, int strategy));
1612 extern PNG_EXPORT(void,png_set_compression_window_bits)
1613 PNGARG((png_structp png_ptr, int window_bits));
1615 extern PNG_EXPORT(void,png_set_compression_method) PNGARG((png_structp png_ptr,
1618 /* These next functions are called for input/output, memory, and error
1619 * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c,
1620 * and call standard C I/O routines such as fread(), fwrite(), and
1621 * fprintf(). These functions can be made to use other I/O routines
1622 * at run time for those applications that need to handle I/O in a
1623 * different manner by calling png_set_???_fn(). See libpng.txt for
1627 #if !defined(PNG_NO_STDIO)
1628 /* Initialize the input/output for the PNG file to the default functions. */
1629 extern PNG_EXPORT(void,png_init_io) PNGARG((png_structp png_ptr, png_FILE_p fp));
1632 /* Replace the (error and abort), and warning functions with user
1633 * supplied functions. If no messages are to be printed you must still
1634 * write and use replacement functions. The replacement error_fn should
1635 * still do a longjmp to the last setjmp location if you are using this
1636 * method of error handling. If error_fn or warning_fn is NULL, the
1637 * default function will be used.
1640 extern PNG_EXPORT(void,png_set_error_fn) PNGARG((png_structp png_ptr,
1641 png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn));
1643 /* Return the user pointer associated with the error functions */
1644 extern PNG_EXPORT(png_voidp,png_get_error_ptr) PNGARG((png_structp png_ptr));
1646 /* Replace the default data output functions with a user supplied one(s).
1647 * If buffered output is not used, then output_flush_fn can be set to NULL.
1648 * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time
1649 * output_flush_fn will be ignored (and thus can be NULL).
1651 extern PNG_EXPORT(void,png_set_write_fn) PNGARG((png_structp png_ptr,
1652 png_voidp io_ptr, png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn));
1654 /* Replace the default data input function with a user supplied one. */
1655 extern PNG_EXPORT(void,png_set_read_fn) PNGARG((png_structp png_ptr,
1656 png_voidp io_ptr, png_rw_ptr read_data_fn));
1658 /* Return the user pointer associated with the I/O functions */
1659 extern PNG_EXPORT(png_voidp,png_get_io_ptr) PNGARG((png_structp png_ptr));
1661 extern PNG_EXPORT(void,png_set_read_status_fn) PNGARG((png_structp png_ptr,
1662 png_read_status_ptr read_row_fn));
1664 extern PNG_EXPORT(void,png_set_write_status_fn) PNGARG((png_structp png_ptr,
1665 png_write_status_ptr write_row_fn));
1667 #ifdef PNG_USER_MEM_SUPPORTED
1668 /* Replace the default memory allocation functions with user supplied one(s). */
1669 extern PNG_EXPORT(void,png_set_mem_fn) PNGARG((png_structp png_ptr,
1670 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn));
1671 /* Return the user pointer associated with the memory functions */
1672 extern PNG_EXPORT(png_voidp,png_get_mem_ptr) PNGARG((png_structp png_ptr));
1675 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
1676 defined(PNG_LEGACY_SUPPORTED)
1677 extern PNG_EXPORT(void,png_set_read_user_transform_fn) PNGARG((png_structp
1678 png_ptr, png_user_transform_ptr read_user_transform_fn));
1681 #if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
1682 defined(PNG_LEGACY_SUPPORTED)
1683 extern PNG_EXPORT(void,png_set_write_user_transform_fn) PNGARG((png_structp
1684 png_ptr, png_user_transform_ptr write_user_transform_fn));
1687 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
1688 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
1689 defined(PNG_LEGACY_SUPPORTED)
1690 extern PNG_EXPORT(void,png_set_user_transform_info) PNGARG((png_structp
1691 png_ptr, png_voidp user_transform_ptr, int user_transform_depth,
1692 int user_transform_channels));
1693 /* Return the user pointer associated with the user transform functions */
1694 extern PNG_EXPORT(png_voidp,png_get_user_transform_ptr)
1695 PNGARG((png_structp png_ptr));
1698 #ifdef PNG_READ_USER_CHUNKS_SUPPORTED
1699 extern PNG_EXPORT(void,png_set_read_user_chunk_fn) PNGARG((png_structp png_ptr,
1700 png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));
1701 extern PNG_EXPORT(png_voidp,png_get_user_chunk_ptr) PNGARG((png_structp
1705 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1706 /* Sets the function callbacks for the push reader, and a pointer to a
1707 * user-defined structure available to the callback functions.
1709 extern PNG_EXPORT(void,png_set_progressive_read_fn) PNGARG((png_structp png_ptr,
1710 png_voidp progressive_ptr,
1711 png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
1712 png_progressive_end_ptr end_fn));
1714 /* returns the user pointer associated with the push read functions */
1715 extern PNG_EXPORT(png_voidp,png_get_progressive_ptr)
1716 PNGARG((png_structp png_ptr));
1718 /* function to be called when data becomes available */
1719 extern PNG_EXPORT(void,png_process_data) PNGARG((png_structp png_ptr,
1720 png_infop info_ptr, png_bytep buffer, png_size_t buffer_size));
1722 /* function that combines rows. Not very much different than the
1723 * png_combine_row() call. Is this even used?????
1725 extern PNG_EXPORT(void,png_progressive_combine_row) PNGARG((png_structp png_ptr,
1726 png_bytep old_row, png_bytep new_row));
1727 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
1729 extern PNG_EXPORT(png_voidp,png_malloc) PNGARG((png_structp png_ptr,
1732 /* frees a pointer allocated by png_malloc() */
1733 extern PNG_EXPORT(void,png_free) PNGARG((png_structp png_ptr, png_voidp ptr));
1735 /* Free data that was allocated internally */
1736 extern PNG_EXPORT(void,png_free_data) PNGARG((png_structp png_ptr,
1737 png_infop info_ptr, png_uint_32 free_me, int num));
1738 #ifdef PNG_FREE_ME_SUPPORTED
1739 /* Reassign responsibility for freeing existing data, whether allocated
1740 * by libpng or by the application */
1741 extern PNG_EXPORT(void,png_data_freer) PNGARG((png_structp png_ptr,
1742 png_infop info_ptr, int freer, png_uint_32 mask));
1744 /* assignments for png_data_freer */
1745 #define PNG_DESTROY_WILL_FREE_DATA 1
1746 #define PNG_SET_WILL_FREE_DATA 1
1747 #define PNG_USER_WILL_FREE_DATA 2
1748 /* Flags for png_ptr->free_me and info_ptr->free_me */
1749 #define PNG_FREE_HIST 0x0008
1750 #define PNG_FREE_ICCP 0x0010
1751 #define PNG_FREE_SPLT 0x0020
1752 #define PNG_FREE_ROWS 0x0040
1753 #define PNG_FREE_PCAL 0x0080
1754 #define PNG_FREE_SCAL 0x0100
1755 #define PNG_FREE_UNKN 0x0200
1756 #define PNG_FREE_LIST 0x0400
1757 #define PNG_FREE_PLTE 0x1000
1758 #define PNG_FREE_TRNS 0x2000
1759 #define PNG_FREE_TEXT 0x4000
1760 #define PNG_FREE_ALL 0x7fff
1761 #define PNG_FREE_MUL 0x4220 /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */
1763 #ifdef PNG_USER_MEM_SUPPORTED
1764 extern PNG_EXPORT(png_voidp,png_malloc_default) PNGARG((png_structp png_ptr,
1766 extern PNG_EXPORT(void,png_free_default) PNGARG((png_structp png_ptr,
1770 extern PNG_EXPORT(png_voidp,png_memcpy_check) PNGARG((png_structp png_ptr,
1771 png_voidp s1, png_voidp s2, png_uint_32 size));
1773 extern PNG_EXPORT(png_voidp,png_memset_check) PNGARG((png_structp png_ptr,
1774 png_voidp s1, int value, png_uint_32 size));
1776 #if defined(USE_FAR_KEYWORD) /* memory model conversion function */
1777 extern void *png_far_to_near PNGARG((png_structp png_ptr,png_voidp ptr,
1779 #endif /* USE_FAR_KEYWORD */
1781 /* Fatal error in PNG image of libpng - can't continue */
1782 extern PNG_EXPORT(void,png_error) PNGARG((png_structp png_ptr,
1783 png_const_charp error));
1785 /* The same, but the chunk name is prepended to the error string. */
1786 extern PNG_EXPORT(void,png_chunk_error) PNGARG((png_structp png_ptr,
1787 png_const_charp error));
1789 /* Non-fatal error in libpng. Can continue, but may have a problem. */
1790 extern PNG_EXPORT(void,png_warning) PNGARG((png_structp png_ptr,
1791 png_const_charp message));
1793 /* Non-fatal error in libpng, chunk name is prepended to message. */
1794 extern PNG_EXPORT(void,png_chunk_warning) PNGARG((png_structp png_ptr,
1795 png_const_charp message));
1797 /* The png_set_<chunk> functions are for storing values in the png_info_struct.
1798 * Similarly, the png_get_<chunk> calls are used to read values from the
1799 * png_info_struct, either storing the parameters in the passed variables, or
1800 * setting pointers into the png_info_struct where the data is stored. The
1801 * png_get_<chunk> functions return a non-zero value if the data was available
1802 * in info_ptr, or return zero and do not change any of the parameters if the
1803 * data was not available.
1805 * These functions should be used instead of directly accessing png_info
1806 * to avoid problems with future changes in the size and internal layout of
1809 /* Returns "flag" if chunk data is valid in info_ptr. */
1810 extern PNG_EXPORT(png_uint_32,png_get_valid) PNGARG((png_structp png_ptr,
1811 png_infop info_ptr, png_uint_32 flag));
1813 /* Returns number of bytes needed to hold a transformed row. */
1814 extern PNG_EXPORT(png_uint_32,png_get_rowbytes) PNGARG((png_structp png_ptr,
1815 png_infop info_ptr));
1817 #if defined(PNG_INFO_IMAGE_SUPPORTED)
1818 /* Returns row_pointers, which is an array of pointers to scanlines that was
1819 returned from png_read_png(). */
1820 extern PNG_EXPORT(png_bytepp,png_get_rows) PNGARG((png_structp png_ptr,
1821 png_infop info_ptr));
1822 /* Set row_pointers, which is an array of pointers to scanlines for use
1823 by png_write_png(). */
1824 extern PNG_EXPORT(void,png_set_rows) PNGARG((png_structp png_ptr,
1825 png_infop info_ptr, png_bytepp row_pointers));
1828 /* Returns number of color channels in image. */
1829 extern PNG_EXPORT(png_byte,png_get_channels) PNGARG((png_structp png_ptr,
1830 png_infop info_ptr));
1832 #ifdef PNG_EASY_ACCESS_SUPPORTED
1833 /* Returns image width in pixels. */
1834 extern PNG_EXPORT(png_uint_32, png_get_image_width) PNGARG((png_structp
1835 png_ptr, png_infop info_ptr));
1837 /* Returns image height in pixels. */
1838 extern PNG_EXPORT(png_uint_32, png_get_image_height) PNGARG((png_structp
1839 png_ptr, png_infop info_ptr));
1841 /* Returns image bit_depth. */
1842 extern PNG_EXPORT(png_byte, png_get_bit_depth) PNGARG((png_structp
1843 png_ptr, png_infop info_ptr));
1845 /* Returns image color_type. */
1846 extern PNG_EXPORT(png_byte, png_get_color_type) PNGARG((png_structp
1847 png_ptr, png_infop info_ptr));
1849 /* Returns image filter_type. */
1850 extern PNG_EXPORT(png_byte, png_get_filter_type) PNGARG((png_structp
1851 png_ptr, png_infop info_ptr));
1853 /* Returns image interlace_type. */
1854 extern PNG_EXPORT(png_byte, png_get_interlace_type) PNGARG((png_structp
1855 png_ptr, png_infop info_ptr));
1857 /* Returns image compression_type. */
1858 extern PNG_EXPORT(png_byte, png_get_compression_type) PNGARG((png_structp
1859 png_ptr, png_infop info_ptr));
1861 /* Returns image resolution in pixels per meter, from pHYs chunk data. */
1862 extern PNG_EXPORT(png_uint_32, png_get_pixels_per_meter) PNGARG((png_structp
1863 png_ptr, png_infop info_ptr));
1864 extern PNG_EXPORT(png_uint_32, png_get_x_pixels_per_meter) PNGARG((png_structp
1865 png_ptr, png_infop info_ptr));
1866 extern PNG_EXPORT(png_uint_32, png_get_y_pixels_per_meter) PNGARG((png_structp
1867 png_ptr, png_infop info_ptr));
1869 /* Returns pixel aspect ratio, computed from pHYs chunk data. */
1870 #ifdef PNG_FLOATING_POINT_SUPPORTED
1871 extern PNG_EXPORT(float, png_get_pixel_aspect_ratio) PNGARG((png_structp
1872 png_ptr, png_infop info_ptr));
1875 /* Returns image x, y offset in pixels or microns, from oFFs chunk data. */
1876 extern PNG_EXPORT(png_int_32, png_get_x_offset_pixels) PNGARG((png_structp
1877 png_ptr, png_infop info_ptr));
1878 extern PNG_EXPORT(png_int_32, png_get_y_offset_pixels) PNGARG((png_structp
1879 png_ptr, png_infop info_ptr));
1880 extern PNG_EXPORT(png_int_32, png_get_x_offset_microns) PNGARG((png_structp
1881 png_ptr, png_infop info_ptr));
1882 extern PNG_EXPORT(png_int_32, png_get_y_offset_microns) PNGARG((png_structp
1883 png_ptr, png_infop info_ptr));
1885 #endif /* PNG_EASY_ACCESS_SUPPORTED */
1887 /* Returns pointer to signature string read from PNG header */
1888 extern PNG_EXPORT(png_bytep,png_get_signature) PNGARG((png_structp png_ptr,
1889 png_infop info_ptr));
1891 #if defined(PNG_READ_bKGD_SUPPORTED)
1892 extern PNG_EXPORT(png_uint_32,png_get_bKGD) PNGARG((png_structp png_ptr,
1893 png_infop info_ptr, png_color_16p *background));
1896 #if defined(PNG_bKGD_SUPPORTED)
1897 extern PNG_EXPORT(void,png_set_bKGD) PNGARG((png_structp png_ptr,
1898 png_infop info_ptr, png_color_16p background));
1901 #if defined(PNG_READ_cHRM_SUPPORTED)
1902 #ifdef PNG_FLOATING_POINT_SUPPORTED
1903 extern PNG_EXPORT(png_uint_32,png_get_cHRM) PNGARG((png_structp png_ptr,
1904 png_infop info_ptr, double *white_x, double *white_y, double *red_x,
1905 double *red_y, double *green_x, double *green_y, double *blue_x,
1908 #ifdef PNG_FIXED_POINT_SUPPORTED
1909 extern PNG_EXPORT(png_uint_32,png_get_cHRM_fixed) PNGARG((png_structp png_ptr,
1910 png_infop info_ptr, png_fixed_point *int_white_x, png_fixed_point
1911 *int_white_y, png_fixed_point *int_red_x, png_fixed_point *int_red_y,
1912 png_fixed_point *int_green_x, png_fixed_point *int_green_y, png_fixed_point
1913 *int_blue_x, png_fixed_point *int_blue_y));
1917 #if defined(PNG_cHRM_SUPPORTED)
1918 #ifdef PNG_FLOATING_POINT_SUPPORTED
1919 extern PNG_EXPORT(void,png_set_cHRM) PNGARG((png_structp png_ptr,
1920 png_infop info_ptr, double white_x, double white_y, double red_x,
1921 double red_y, double green_x, double green_y, double blue_x, double blue_y));
1923 #ifdef PNG_FIXED_POINT_SUPPORTED
1924 extern PNG_EXPORT(void,png_set_cHRM_fixed) PNGARG((png_structp png_ptr,
1925 png_infop info_ptr, png_fixed_point int_white_x, png_fixed_point int_white_y,
1926 png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
1927 int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
1928 png_fixed_point int_blue_y));
1932 #if defined(PNG_READ_gAMA_SUPPORTED)
1933 #ifdef PNG_FLOATING_POINT_SUPPORTED
1934 extern PNG_EXPORT(png_uint_32,png_get_gAMA) PNGARG((png_structp png_ptr,
1935 png_infop info_ptr, double *file_gamma));
1937 extern PNG_EXPORT(png_uint_32,png_get_gAMA_fixed) PNGARG((png_structp png_ptr,
1938 png_infop info_ptr, png_fixed_point *int_file_gamma));
1941 #if defined(PNG_gAMA_SUPPORTED)
1942 #ifdef PNG_FLOATING_POINT_SUPPORTED
1943 extern PNG_EXPORT(void,png_set_gAMA) PNGARG((png_structp png_ptr,
1944 png_infop info_ptr, double file_gamma));
1946 extern PNG_EXPORT(void,png_set_gAMA_fixed) PNGARG((png_structp png_ptr,
1947 png_infop info_ptr, png_fixed_point int_file_gamma));
1950 #if defined(PNG_READ_hIST_SUPPORTED)
1951 extern PNG_EXPORT(png_uint_32,png_get_hIST) PNGARG((png_structp png_ptr,
1952 png_infop info_ptr, png_uint_16p *hist));
1955 #if defined(PNG_hIST_SUPPORTED)
1956 extern PNG_EXPORT(void,png_set_hIST) PNGARG((png_structp png_ptr,
1957 png_infop info_ptr, png_uint_16p hist));
1960 extern PNG_EXPORT(png_uint_32,png_get_IHDR) PNGARG((png_structp png_ptr,
1961 png_infop info_ptr, png_uint_32 *width, png_uint_32 *height,
1962 int *bit_depth, int *color_type, int *interlace_method,
1963 int *compression_method, int *filter_method));
1965 extern PNG_EXPORT(void,png_set_IHDR) PNGARG((png_structp png_ptr,
1966 png_infop info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth,
1967 int color_type, int interlace_method, int compression_method,
1968 int filter_method));
1970 #if defined(PNG_READ_oFFs_SUPPORTED)
1971 extern PNG_EXPORT(png_uint_32,png_get_oFFs) PNGARG((png_structp png_ptr,
1972 png_infop info_ptr, png_int_32 *offset_x, png_int_32 *offset_y,
1976 #if defined(PNG_oFFs_SUPPORTED)
1977 extern PNG_EXPORT(void,png_set_oFFs) PNGARG((png_structp png_ptr,
1978 png_infop info_ptr, png_int_32 offset_x, png_int_32 offset_y,
1982 #if defined(PNG_READ_pCAL_SUPPORTED)
1983 extern PNG_EXPORT(png_uint_32,png_get_pCAL) PNGARG((png_structp png_ptr,
1984 png_infop info_ptr, png_charp *purpose, png_int_32 *X0, png_int_32 *X1,
1985 int *type, int *nparams, png_charp *units, png_charpp *params));
1988 #if defined(PNG_pCAL_SUPPORTED)
1989 extern PNG_EXPORT(void,png_set_pCAL) PNGARG((png_structp png_ptr,
1990 png_infop info_ptr, png_charp purpose, png_int_32 X0, png_int_32 X1,
1991 int type, int nparams, png_charp units, png_charpp params));
1994 #if defined(PNG_READ_pHYs_SUPPORTED)
1995 extern PNG_EXPORT(png_uint_32,png_get_pHYs) PNGARG((png_structp png_ptr,
1996 png_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type));
1999 #if defined(PNG_pHYs_SUPPORTED)
2000 extern PNG_EXPORT(void,png_set_pHYs) PNGARG((png_structp png_ptr,
2001 png_infop info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type));
2004 extern PNG_EXPORT(png_uint_32,png_get_PLTE) PNGARG((png_structp png_ptr,
2005 png_infop info_ptr, png_colorp *palette, int *num_palette));
2007 extern PNG_EXPORT(void,png_set_PLTE) PNGARG((png_structp png_ptr,
2008 png_infop info_ptr, png_colorp palette, int num_palette));
2010 #if defined(PNG_READ_sBIT_SUPPORTED)
2011 extern PNG_EXPORT(png_uint_32,png_get_sBIT) PNGARG((png_structp png_ptr,
2012 png_infop info_ptr, png_color_8p *sig_bit));
2015 #if defined(PNG_sBIT_SUPPORTED)
2016 extern PNG_EXPORT(void,png_set_sBIT) PNGARG((png_structp png_ptr,
2017 png_infop info_ptr, png_color_8p sig_bit));
2020 #if defined(PNG_READ_sRGB_SUPPORTED)
2021 extern PNG_EXPORT(png_uint_32,png_get_sRGB) PNGARG((png_structp png_ptr,
2022 png_infop info_ptr, int *intent));
2025 #if defined(PNG_sRGB_SUPPORTED)
2026 extern PNG_EXPORT(void,png_set_sRGB) PNGARG((png_structp png_ptr,
2027 png_infop info_ptr, int intent));
2028 extern PNG_EXPORT(void,png_set_sRGB_gAMA_and_cHRM) PNGARG((png_structp png_ptr,
2029 png_infop info_ptr, int intent));
2032 #if defined(PNG_READ_iCCP_SUPPORTED)
2033 extern PNG_EXPORT(png_uint_32,png_get_iCCP) PNGARG((png_structp png_ptr,
2034 png_infop info_ptr, png_charpp name, int *compression_type,
2035 png_charpp profile, png_uint_32 *proflen));
2036 /* Note to maintainer: profile should be png_bytepp */
2039 #if defined(PNG_iCCP_SUPPORTED)
2040 extern PNG_EXPORT(void,png_set_iCCP) PNGARG((png_structp png_ptr,
2041 png_infop info_ptr, png_charp name, int compression_type,
2042 png_charp profile, png_uint_32 proflen));
2043 /* Note to maintainer: profile should be png_bytep */
2046 #if defined(PNG_READ_sPLT_SUPPORTED)
2047 extern PNG_EXPORT(png_uint_32,png_get_sPLT) PNGARG((png_structp png_ptr,
2048 png_infop info_ptr, png_sPLT_tpp entries));
2051 #if defined(PNG_sPLT_SUPPORTED)
2052 extern PNG_EXPORT(void,png_set_sPLT) PNGARG((png_structp png_ptr,
2053 png_infop info_ptr, png_sPLT_tp entries, int nentries));
2056 #if defined(PNG_READ_TEXT_SUPPORTED)
2057 /* png_get_text also returns the number of text chunks in *num_text */
2058 extern PNG_EXPORT(png_uint_32,png_get_text) PNGARG((png_structp png_ptr,
2059 png_infop info_ptr, png_textp *text_ptr, int *num_text));
2063 * Note while png_set_text() will accept a structure whose text,
2064 * language, and translated keywords are NULL pointers, the structure
2065 * returned by png_get_text will always contain regular
2066 * zero-terminated C strings. They might be empty strings but
2067 * they will never be NULL pointers.
2070 #if defined(PNG_TEXT_SUPPORTED)
2071 extern PNG_EXPORT(void,png_set_text) PNGARG((png_structp png_ptr,
2072 png_infop info_ptr, png_textp text_ptr, int num_text));
2075 #if defined(PNG_READ_tIME_SUPPORTED)
2076 extern PNG_EXPORT(png_uint_32,png_get_tIME) PNGARG((png_structp png_ptr,
2077 png_infop info_ptr, png_timep *mod_time));
2080 #if defined(PNG_tIME_SUPPORTED)
2081 extern PNG_EXPORT(void,png_set_tIME) PNGARG((png_structp png_ptr,
2082 png_infop info_ptr, png_timep mod_time));
2085 #if defined(PNG_READ_tRNS_SUPPORTED)
2086 extern PNG_EXPORT(png_uint_32,png_get_tRNS) PNGARG((png_structp png_ptr,
2087 png_infop info_ptr, png_bytep *trans, int *num_trans,
2088 png_color_16p *trans_values));
2091 #if defined(PNG_tRNS_SUPPORTED)
2092 extern PNG_EXPORT(void,png_set_tRNS) PNGARG((png_structp png_ptr,
2093 png_infop info_ptr, png_bytep trans, int num_trans,
2094 png_color_16p trans_values));
2097 #if defined(PNG_tRNS_SUPPORTED)
2100 #if defined(PNG_READ_sCAL_SUPPORTED)
2101 #ifdef PNG_FLOATING_POINT_SUPPORTED
2102 extern PNG_EXPORT(png_uint_32,png_get_sCAL) PNGARG((png_structp png_ptr,
2103 png_infop info_ptr, int *unit, double *width, double *height));
2105 #ifdef PNG_FIXED_POINT_SUPPORTED
2106 extern PNG_EXPORT(png_uint_32,png_get_sCAL_s) PNGARG((png_structp png_ptr,
2107 png_infop info_ptr, int *unit, png_charpp swidth, png_charpp sheight));
2110 #endif /* PNG_READ_sCAL_SUPPORTED */
2112 #if defined(PNG_sCAL_SUPPORTED)
2113 #ifdef PNG_FLOATING_POINT_SUPPORTED
2114 extern PNG_EXPORT(void,png_set_sCAL) PNGARG((png_structp png_ptr,
2115 png_infop info_ptr, int unit, double width, double height));
2117 #ifdef PNG_FIXED_POINT_SUPPORTED
2118 extern PNG_EXPORT(void,png_set_sCAL_s) PNGARG((png_structp png_ptr,
2119 png_infop info_ptr, int unit, png_charp swidth, png_charp sheight));
2121 #endif /* PNG_READ_sCAL_SUPPORTED || PNG_WRITE_sCAL_SUPPORTED */
2123 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
2124 /* provide a list of chunks and how they are to be handled, if the built-in
2125 handling or default unknown chunk handling is not desired. Any chunks not
2126 listed will be handled in the default manner. The IHDR and IEND chunks
2128 keep = 0: follow default behavour
2130 = 2: keep only if safe-to-copy
2131 = 3: keep even if unsafe-to-copy
2133 extern PNG_EXPORT(void, png_set_keep_unknown_chunks) PNGARG((png_structp
2134 png_ptr, int keep, png_bytep chunk_list, int num_chunks));
2135 extern PNG_EXPORT(void, png_set_unknown_chunks) PNGARG((png_structp png_ptr,
2136 png_infop info_ptr, png_unknown_chunkp unknowns, int num_unknowns));
2137 extern PNG_EXPORT(void, png_set_unknown_chunk_location)
2138 PNGARG((png_structp png_ptr, png_infop info_ptr, int chunk, int location));
2139 extern PNG_EXPORT(png_uint_32,png_get_unknown_chunks) PNGARG((png_structp
2140 png_ptr, png_infop info_ptr, png_unknown_chunkpp entries));
2143 /* Png_free_data() will turn off the "valid" flag for anything it frees.
2144 If you need to turn it off for a chunk that your application has freed,
2145 you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK); */
2146 extern PNG_EXPORT(void, png_set_invalid) PNGARG((png_structp png_ptr,
2147 png_infop info_ptr, int mask));
2149 #if defined(PNG_INFO_IMAGE_SUPPORTED)
2150 /* The "params" pointer is currently not used and is for future expansion. */
2151 extern PNG_EXPORT(void, png_read_png) PNGARG((png_structp png_ptr,
2155 extern PNG_EXPORT(void, png_write_png) PNGARG((png_structp png_ptr,
2161 /* Define PNG_DEBUG at compile time for debugging information. Higher
2162 * numbers for PNG_DEBUG mean more debugging information. This has
2163 * only been added since version 0.95 so it is not implemented throughout
2164 * libpng yet, but more support will be added as needed.
2168 #if !defined(PNG_DEBUG_FILE) && defined(_MSC_VER)
2171 #define png_debug(l,m) _RPT0(_CRT_WARN,m)
2172 #define png_debug1(l,m,p1) _RPT1(_CRT_WARN,m,p1)
2173 #define png_debug2(l,m,p1,p2) _RPT2(_CRT_WARN,m,p1,p2)
2175 #else /* PNG_DEBUG_FILE || !_MSC_VER */
2176 #ifndef PNG_DEBUG_FILE
2177 #define PNG_DEBUG_FILE stderr
2178 #endif /* PNG_DEBUG_FILE */
2180 #define png_debug(l,m) \
2183 fprintf(PNG_DEBUG_FILE,"%s"m,(num_tabs==1 ? "\t" : \
2184 (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":"")))); \
2186 #define png_debug1(l,m,p1) \
2189 fprintf(PNG_DEBUG_FILE,"%s"m,(num_tabs==1 ? "\t" : \
2190 (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1); \
2192 #define png_debug2(l,m,p1,p2) \
2195 fprintf(PNG_DEBUG_FILE,"%s"m,(num_tabs==1 ? "\t" : \
2196 (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1,p2); \
2198 #endif /* (PNG_DEBUG > 1) */
2199 #endif /* _MSC_VER */
2200 #endif /* (PNG_DEBUG > 0) */
2201 #endif /* PNG_DEBUG */
2203 #define png_debug(l, m)
2206 #define png_debug1(l, m, p1)
2209 #define png_debug2(l, m, p1, p2)
2212 extern PNG_EXPORT(png_bytep,png_sig_bytes) PNGARG((void));
2214 extern PNG_EXPORT(png_charp,png_get_copyright) PNGARG((png_structp png_ptr));
2215 extern PNG_EXPORT(png_charp,png_get_header_ver) PNGARG((png_structp png_ptr));
2216 extern PNG_EXPORT(png_charp,png_get_header_version) PNGARG((png_structp png_ptr));
2217 extern PNG_EXPORT(png_charp,png_get_libpng_ver) PNGARG((png_structp png_ptr));
2219 #ifdef PNG_MNG_FEATURES_SUPPORTED
2220 extern PNG_EXPORT(png_uint_32,png_permit_mng_features) PNGARG((png_structp
2221 png_ptr, png_uint_32 mng_features_permitted));
2224 #if 0 /* delay these until version 1.2.0 */
2225 /* png.c, pnggccrd.c, or pngvcrd.c */
2226 extern PNG_EXPORT(int,png_mmx_support) PNGARG((void));
2229 /* Maintainer: Put new public prototypes here ^, in libpng.3, and project defs */
2231 #define PNG_HEADER_VERSION_STRING \
2232 " libpng version 1.0.9 - January 31, 2001 (header)\n"
2234 #ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
2235 /* With these routines we avoid an integer divide, which will be slower on
2236 * most machines. However, it does take more operations than the corresponding
2237 * divide method, so it may be slower on a few RISC systems. There are two
2238 * shifts (by 8 or 16 bits) and an addition, versus a single integer divide.
2240 * Note that the rounding factors are NOT supposed to be the same! 128 and
2241 * 32768 are correct for the NODIV code; 127 and 32767 are correct for the
2244 * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
2247 /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */
2249 # define png_composite(composite, fg, alpha, bg) \
2250 { png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) * (png_uint_16)(alpha) \
2251 + (png_uint_16)(bg)*(png_uint_16)(255 - \
2252 (png_uint_16)(alpha)) + (png_uint_16)128); \
2253 (composite) = (png_byte)((temp + (temp >> 8)) >> 8); }
2255 # define png_composite_16(composite, fg, alpha, bg) \
2256 { png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) * (png_uint_32)(alpha) \
2257 + (png_uint_32)(bg)*(png_uint_32)(65535L - \
2258 (png_uint_32)(alpha)) + (png_uint_32)32768L); \
2259 (composite) = (png_uint_16)((temp + (temp >> 16)) >> 16); }
2261 #else /* standard method using integer division */
2263 # define png_composite(composite, fg, alpha, bg) \
2264 (composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) + \
2265 (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \
2266 (png_uint_16)127) / 255)
2268 # define png_composite_16(composite, fg, alpha, bg) \
2269 (composite) = (png_uint_16)(((png_uint_32)(fg) * (png_uint_32)(alpha) + \
2270 (png_uint_32)(bg)*(png_uint_32)(65535L - (png_uint_32)(alpha)) + \
2271 (png_uint_32)32767) / (png_uint_32)65535L)
2273 #endif /* PNG_READ_COMPOSITE_NODIV_SUPPORTED */
2275 /* These next functions are used internally in the code. They generally
2276 * shouldn't be used unless you are writing code to add or replace some
2277 * functionality in libpng. More information about most functions can
2278 * be found in the files where the functions are located.
2281 #if defined(PNG_INTERNAL)
2283 /* Various modes of operation. Note that after an init, mode is set to
2284 * zero automatically when the structure is created.
2286 #define PNG_HAVE_IHDR 0x01
2287 #define PNG_HAVE_PLTE 0x02
2288 #define PNG_HAVE_IDAT 0x04
2289 #define PNG_AFTER_IDAT 0x08
2290 #define PNG_HAVE_IEND 0x10
2291 #define PNG_HAVE_gAMA 0x20
2292 #define PNG_HAVE_cHRM 0x40
2293 #define PNG_HAVE_sRGB 0x80
2294 #define PNG_HAVE_CHUNK_HEADER 0x100
2295 #define PNG_WROTE_tIME 0x200
2296 #define PNG_WROTE_INFO_BEFORE_PLTE 0x400
2297 #define PNG_BACKGROUND_IS_GRAY 0x800
2298 #define PNG_HAVE_PNG_SIGNATURE 0x1000
2300 /* flags for the transformations the PNG library does on the image data */
2301 #define PNG_BGR 0x0001
2302 #define PNG_INTERLACE 0x0002
2303 #define PNG_PACK 0x0004
2304 #define PNG_SHIFT 0x0008
2305 #define PNG_SWAP_BYTES 0x0010
2306 #define PNG_INVERT_MONO 0x0020
2307 #define PNG_DITHER 0x0040
2308 #define PNG_BACKGROUND 0x0080
2309 #define PNG_BACKGROUND_EXPAND 0x0100
2311 #define PNG_16_TO_8 0x0400
2312 #define PNG_RGBA 0x0800
2313 #define PNG_EXPAND 0x1000
2314 #define PNG_GAMMA 0x2000
2315 #define PNG_GRAY_TO_RGB 0x4000
2316 #define PNG_FILLER 0x8000L
2317 #define PNG_PACKSWAP 0x10000L
2318 #define PNG_SWAP_ALPHA 0x20000L
2319 #define PNG_STRIP_ALPHA 0x40000L
2320 #define PNG_INVERT_ALPHA 0x80000L
2321 #define PNG_USER_TRANSFORM 0x100000L
2322 #define PNG_RGB_TO_GRAY_ERR 0x200000L
2323 #define PNG_RGB_TO_GRAY_WARN 0x400000L
2324 #define PNG_RGB_TO_GRAY 0x600000L /* two bits, RGB_TO_GRAY_ERR|WARN */
2326 /* flags for png_create_struct */
2327 #define PNG_STRUCT_PNG 0x0001
2328 #define PNG_STRUCT_INFO 0x0002
2330 /* Scaling factor for filter heuristic weighting calculations */
2331 #define PNG_WEIGHT_SHIFT 8
2332 #define PNG_WEIGHT_FACTOR (1<<(PNG_WEIGHT_SHIFT))
2333 #define PNG_COST_SHIFT 3
2334 #define PNG_COST_FACTOR (1<<(PNG_COST_SHIFT))
2336 /* flags for the png_ptr->flags rather than declaring a byte for each one */
2337 #define PNG_FLAG_ZLIB_CUSTOM_STRATEGY 0x0001
2338 #define PNG_FLAG_ZLIB_CUSTOM_LEVEL 0x0002
2339 #define PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL 0x0004
2340 #define PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS 0x0008
2341 #define PNG_FLAG_ZLIB_CUSTOM_METHOD 0x0010
2342 #define PNG_FLAG_ZLIB_FINISHED 0x0020
2343 #define PNG_FLAG_ROW_INIT 0x0040
2344 #define PNG_FLAG_FILLER_AFTER 0x0080
2345 #define PNG_FLAG_CRC_ANCILLARY_USE 0x0100
2346 #define PNG_FLAG_CRC_ANCILLARY_NOWARN 0x0200
2347 #define PNG_FLAG_CRC_CRITICAL_USE 0x0400
2348 #define PNG_FLAG_CRC_CRITICAL_IGNORE 0x0800
2349 #define PNG_FLAG_FREE_PLTE 0x1000
2350 #define PNG_FLAG_FREE_TRNS 0x2000
2351 #define PNG_FLAG_FREE_HIST 0x4000
2352 #define PNG_FLAG_KEEP_UNKNOWN_CHUNKS 0x8000L
2353 #define PNG_FLAG_KEEP_UNSAFE_CHUNKS 0x10000L
2354 #define PNG_FLAG_LIBRARY_MISMATCH 0x20000L
2356 /* For use in png_set_keep_unknown, png_handle_as_unknown */
2357 #define HANDLE_CHUNK_AS_DEFAULT 0
2358 #define HANDLE_CHUNK_NEVER 1
2359 #define HANDLE_CHUNK_IF_SAFE 2
2360 #define HANDLE_CHUNK_ALWAYS 3
2362 #define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \
2363 PNG_FLAG_CRC_ANCILLARY_NOWARN)
2365 #define PNG_FLAG_CRC_CRITICAL_MASK (PNG_FLAG_CRC_CRITICAL_USE | \
2366 PNG_FLAG_CRC_CRITICAL_IGNORE)
2368 #define PNG_FLAG_CRC_MASK (PNG_FLAG_CRC_ANCILLARY_MASK | \
2369 PNG_FLAG_CRC_CRITICAL_MASK)
2371 /* save typing and make code easier to understand */
2372 #define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \
2373 abs((int)((c1).green) - (int)((c2).green)) + \
2374 abs((int)((c1).blue) - (int)((c2).blue)))
2376 /* variables declared in png.c - only it needs to define PNG_NO_EXTERN */
2377 #if !defined(PNG_NO_EXTERN) || defined(PNG_ALWAYS_EXTERN)
2378 /* place to hold the signature string for a PNG file. */
2379 #ifdef PNG_USE_GLOBAL_ARRAYS
2380 PNG_EXPORT_VAR (const png_byte FARDATA) png_sig[8];
2382 #define png_sig png_sig_bytes(NULL)
2384 #endif /* PNG_NO_EXTERN */
2386 /* Constant strings for known chunk types. If you need to add a chunk,
2387 * define the name here, and add an invocation of the macro in png.c and
2388 * wherever it's needed.
2390 #define PNG_IHDR const png_byte png_IHDR[5] = { 73, 72, 68, 82, '\0'}
2391 #define PNG_IDAT const png_byte png_IDAT[5] = { 73, 68, 65, 84, '\0'}
2392 #define PNG_IEND const png_byte png_IEND[5] = { 73, 69, 78, 68, '\0'}
2393 #define PNG_PLTE const png_byte png_PLTE[5] = { 80, 76, 84, 69, '\0'}
2394 #define PNG_bKGD const png_byte png_bKGD[5] = { 98, 75, 71, 68, '\0'}
2395 #define PNG_cHRM const png_byte png_cHRM[5] = { 99, 72, 82, 77, '\0'}
2396 #define PNG_gAMA const png_byte png_gAMA[5] = {103, 65, 77, 65, '\0'}
2397 #define PNG_hIST const png_byte png_hIST[5] = {104, 73, 83, 84, '\0'}
2398 #define PNG_iCCP const png_byte png_iCCP[5] = {105, 67, 67, 80, '\0'}
2399 #define PNG_iTXt const png_byte png_iTXt[5] = {105, 84, 88, 116, '\0'}
2400 #define PNG_oFFs const png_byte png_oFFs[5] = {111, 70, 70, 115, '\0'}
2401 #define PNG_pCAL const png_byte png_pCAL[5] = {112, 67, 65, 76, '\0'}
2402 #define PNG_sCAL const png_byte png_sCAL[5] = {115, 67, 65, 76, '\0'}
2403 #define PNG_pHYs const png_byte png_pHYs[5] = {112, 72, 89, 115, '\0'}
2404 #define PNG_sBIT const png_byte png_sBIT[5] = {115, 66, 73, 84, '\0'}
2405 #define PNG_sPLT const png_byte png_sPLT[5] = {115, 80, 76, 84, '\0'}
2406 #define PNG_sRGB const png_byte png_sRGB[5] = {115, 82, 71, 66, '\0'}
2407 #define PNG_tEXt const png_byte png_tEXt[5] = {116, 69, 88, 116, '\0'}
2408 #define PNG_tIME const png_byte png_tIME[5] = {116, 73, 77, 69, '\0'}
2409 #define PNG_tRNS const png_byte png_tRNS[5] = {116, 82, 78, 83, '\0'}
2410 #define PNG_zTXt const png_byte png_zTXt[5] = {122, 84, 88, 116, '\0'}
2412 #ifdef PNG_USE_GLOBAL_ARRAYS
2413 PNG_EXPORT_VAR (const png_byte FARDATA) png_IHDR[5];
2414 PNG_EXPORT_VAR (const png_byte FARDATA) png_IDAT[5];
2415 PNG_EXPORT_VAR (const png_byte FARDATA) png_IEND[5];
2416 PNG_EXPORT_VAR (const png_byte FARDATA) png_PLTE[5];
2417 PNG_EXPORT_VAR (const png_byte FARDATA) png_bKGD[5];
2418 PNG_EXPORT_VAR (const png_byte FARDATA) png_cHRM[5];
2419 PNG_EXPORT_VAR (const png_byte FARDATA) png_gAMA[5];
2420 PNG_EXPORT_VAR (const png_byte FARDATA) png_hIST[5];
2421 PNG_EXPORT_VAR (const png_byte FARDATA) png_iCCP[5];
2422 PNG_EXPORT_VAR (const png_byte FARDATA) png_iTXt[5];
2423 PNG_EXPORT_VAR (const png_byte FARDATA) png_oFFs[5];
2424 PNG_EXPORT_VAR (const png_byte FARDATA) png_pCAL[5];
2425 PNG_EXPORT_VAR (const png_byte FARDATA) png_sCAL[5];
2426 PNG_EXPORT_VAR (const png_byte FARDATA) png_pHYs[5];
2427 PNG_EXPORT_VAR (const png_byte FARDATA) png_sBIT[5];
2428 PNG_EXPORT_VAR (const png_byte FARDATA) png_sPLT[5];
2429 PNG_EXPORT_VAR (const png_byte FARDATA) png_sRGB[5];
2430 PNG_EXPORT_VAR (const png_byte FARDATA) png_tEXt[5];
2431 PNG_EXPORT_VAR (const png_byte FARDATA) png_tIME[5];
2432 PNG_EXPORT_VAR (const png_byte FARDATA) png_tRNS[5];
2433 PNG_EXPORT_VAR (const png_byte FARDATA) png_zTXt[5];
2434 #endif /* PNG_USE_GLOBAL_ARRAYS */
2437 /* Inline macros to do direct reads of bytes from the input buffer. These
2438 * require that you are using an architecture that uses PNG byte ordering
2439 * (MSB first) and supports unaligned data storage. I think that PowerPC
2440 * in big-endian mode and 680x0 are the only ones that will support this.
2441 * The x86 line of processors definitely do not. The png_get_int_32()
2442 * routine also assumes we are using two's complement format for negative
2443 * values, which is almost certainly true.
2445 #if defined(PNG_READ_BIG_ENDIAN_SUPPORTED)
2446 # if defined(PNG_READ_pCAL_SUPPORTED) || defined(PNG_READ_oFFs_SUPPORTED)
2447 # define png_get_int_32(buf) ( *((png_int_32p) (buf)))
2449 # define png_get_uint_32(buf) ( *((png_uint_32p) (buf)))
2450 # define png_get_uint_16(buf) ( *((png_uint_16p) (buf)))
2452 # if defined(PNG_READ_pCAL_SUPPORTED) || defined(PNG_READ_oFFs_SUPPORTED)
2453 PNG_EXTERN png_int_32 png_get_int_32 PNGARG((png_bytep buf));
2455 PNG_EXTERN png_uint_32 png_get_uint_32 PNGARG((png_bytep buf));
2456 PNG_EXTERN png_uint_16 png_get_uint_16 PNGARG((png_bytep buf));
2457 #endif /* !PNG_READ_BIG_ENDIAN_SUPPORTED */
2459 /* Initialize png_ptr struct for reading, and allocate any other memory.
2460 * (old interface - DEPRECATED - use png_create_read_struct instead).
2462 extern PNG_EXPORT(void,png_read_init) PNGARG((png_structp png_ptr));
2463 #define png_read_init(png_ptr) png_read_init_2(png_ptr, \
2464 PNG_LIBPNG_VER_STRING, sizeof(png_struct), sizeof(png_info));
2465 extern PNG_EXPORT(void,png_read_init_2) PNGARG((png_structp png_ptr,
2466 png_const_charp user_png_ver, png_size_t png_struct_size, png_size_t
2469 /* Initialize png_ptr struct for writing, and allocate any other memory.
2470 * (old interface - DEPRECATED - use png_create_write_struct instead).
2472 extern PNG_EXPORT(void,png_write_init) PNGARG((png_structp png_ptr));
2473 #define png_write_init(png_ptr) png_write_init_2(png_ptr, \
2474 PNG_LIBPNG_VER_STRING, sizeof(png_struct), sizeof(png_info));
2475 extern PNG_EXPORT(void,png_write_init_2) PNGARG((png_structp png_ptr,
2476 png_const_charp user_png_ver, png_size_t png_struct_size, png_size_t
2479 /* Allocate memory for an internal libpng struct */
2480 PNG_EXTERN png_voidp png_create_struct PNGARG((int type));
2482 /* Free memory from internal libpng struct */
2483 PNG_EXTERN void png_destroy_struct PNGARG((png_voidp struct_ptr));
2485 PNG_EXTERN png_voidp png_create_struct_2 PNGARG((int type, png_malloc_ptr
2487 PNG_EXTERN void png_destroy_struct_2 PNGARG((png_voidp struct_ptr,
2488 png_free_ptr free_fn));
2490 /* Free any memory that info_ptr points to and reset struct. */
2491 PNG_EXTERN void png_info_destroy PNGARG((png_structp png_ptr,
2492 png_infop info_ptr));
2494 /* Function to allocate memory for zlib. */
2495 PNG_EXTERN voidpf png_zalloc PNGARG((voidpf png_ptr, uInt items, uInt size));
2497 /* Function to free memory for zlib */
2498 PNG_EXTERN void png_zfree PNGARG((voidpf png_ptr, voidpf ptr));
2500 /* Reset the CRC variable */
2501 PNG_EXTERN void png_reset_crc PNGARG((png_structp png_ptr));
2503 /* Write the "data" buffer to whatever output you are using. */
2504 PNG_EXTERN void png_write_data PNGARG((png_structp png_ptr, png_bytep data,
2505 png_size_t length));
2507 /* Read data from whatever input you are using into the "data" buffer */
2508 PNG_EXTERN void png_read_data PNGARG((png_structp png_ptr, png_bytep data,
2509 png_size_t length));
2511 /* Read bytes into buf, and update png_ptr->crc */
2512 PNG_EXTERN void png_crc_read PNGARG((png_structp png_ptr, png_bytep buf,
2513 png_size_t length));
2515 /* Decompress data in a chunk that uses compression */
2516 #if defined(PNG_READ_zTXt_SUPPORTED) || defined(PNG_READ_iTXt_SUPPORTED) || \
2517 defined(PNG_READ_iCCP_SUPPORTED) || defined(PNG_READ_sPLT_SUPPORTED)
2518 PNG_EXTERN png_charp png_decompress_chunk PNGARG((png_structp png_ptr,
2519 int comp_type, png_charp chunkdata, png_size_t chunklength,
2520 png_size_t prefix_length, png_size_t *data_length));
2523 /* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */
2524 PNG_EXTERN int png_crc_finish PNGARG((png_structp png_ptr, png_uint_32 skip));
2526 /* Read the CRC from the file and compare it to the libpng calculated CRC */
2527 PNG_EXTERN int png_crc_error PNGARG((png_structp png_ptr));
2529 /* Calculate the CRC over a section of data. Note that we are only
2530 * passing a maximum of 64K on systems that have this as a memory limit,
2531 * since this is the maximum buffer size we can specify.
2533 PNG_EXTERN void png_calculate_crc PNGARG((png_structp png_ptr, png_bytep ptr,
2534 png_size_t length));
2536 #if defined(PNG_WRITE_FLUSH_SUPPORTED)
2537 PNG_EXTERN void png_flush PNGARG((png_structp png_ptr));
2540 /* Place a 32-bit number into a buffer in PNG byte order (big-endian).
2541 * The only currently known PNG chunks that use signed numbers are
2542 * the ancillary extension chunks, oFFs and pCAL.
2544 PNG_EXTERN void png_save_uint_32 PNGARG((png_bytep buf, png_uint_32 i));
2546 #if defined(PNG_WRITE_pCAL_SUPPORTED)
2547 PNG_EXTERN void png_save_int_32 PNGARG((png_bytep buf, png_int_32 i));
2550 /* Place a 16-bit number into a buffer in PNG byte order.
2551 * The parameter is declared unsigned int, not png_uint_16,
2552 * just to avoid potential problems on pre-ANSI C compilers.
2554 PNG_EXTERN void png_save_uint_16 PNGARG((png_bytep buf, unsigned int i));
2556 /* simple function to write the signature */
2557 PNG_EXTERN void png_write_sig PNGARG((png_structp png_ptr));
2559 /* write various chunks */
2561 /* Write the IHDR chunk, and update the png_struct with the necessary
2564 PNG_EXTERN void png_write_IHDR PNGARG((png_structp png_ptr, png_uint_32 width,
2566 int bit_depth, int color_type, int compression_method, int filter_method,
2567 int interlace_method));
2569 PNG_EXTERN void png_write_PLTE PNGARG((png_structp png_ptr, png_colorp palette,
2570 png_uint_32 num_pal));
2572 PNG_EXTERN void png_write_IDAT PNGARG((png_structp png_ptr, png_bytep data,
2573 png_size_t length));
2575 PNG_EXTERN void png_write_IEND PNGARG((png_structp png_ptr));
2577 #if defined(PNG_WRITE_gAMA_SUPPORTED)
2578 #ifdef PNG_FLOATING_POINT_SUPPORTED
2579 PNG_EXTERN void png_write_gAMA PNGARG((png_structp png_ptr, double file_gamma));
2581 #ifdef PNG_FIXED_POINT_SUPPORTED
2582 PNG_EXTERN void png_write_gAMA_fixed PNGARG((png_structp png_ptr, png_fixed_point
2587 #if defined(PNG_WRITE_sBIT_SUPPORTED)
2588 PNG_EXTERN void png_write_sBIT PNGARG((png_structp png_ptr, png_color_8p sbit,
2592 #if defined(PNG_WRITE_cHRM_SUPPORTED)
2593 #ifdef PNG_FLOATING_POINT_SUPPORTED
2594 PNG_EXTERN void png_write_cHRM PNGARG((png_structp png_ptr,
2595 double white_x, double white_y,
2596 double red_x, double red_y, double green_x, double green_y,
2597 double blue_x, double blue_y));
2599 #ifdef PNG_FIXED_POINT_SUPPORTED
2600 PNG_EXTERN void png_write_cHRM_fixed PNGARG((png_structp png_ptr,
2601 png_fixed_point int_white_x, png_fixed_point int_white_y,
2602 png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
2603 int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
2604 png_fixed_point int_blue_y));
2608 #if defined(PNG_WRITE_sRGB_SUPPORTED)
2609 PNG_EXTERN void png_write_sRGB PNGARG((png_structp png_ptr,
2613 #if defined(PNG_WRITE_iCCP_SUPPORTED)
2614 PNG_EXTERN void png_write_iCCP PNGARG((png_structp png_ptr,
2615 png_charp name, int compression_type,
2616 png_charp profile, int proflen));
2617 /* Note to maintainer: profile should be png_bytep */
2620 #if defined(PNG_WRITE_sPLT_SUPPORTED)
2621 PNG_EXTERN void png_write_sPLT PNGARG((png_structp png_ptr,
2622 png_sPLT_tp palette));
2625 #if defined(PNG_WRITE_tRNS_SUPPORTED)
2626 PNG_EXTERN void png_write_tRNS PNGARG((png_structp png_ptr, png_bytep trans,
2627 png_color_16p values, int number, int color_type));
2630 #if defined(PNG_WRITE_bKGD_SUPPORTED)
2631 PNG_EXTERN void png_write_bKGD PNGARG((png_structp png_ptr,
2632 png_color_16p values, int color_type));
2635 #if defined(PNG_WRITE_hIST_SUPPORTED)
2636 PNG_EXTERN void png_write_hIST PNGARG((png_structp png_ptr, png_uint_16p hist,
2640 #if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \
2641 defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
2642 PNG_EXTERN png_size_t png_check_keyword PNGARG((png_structp png_ptr,
2643 png_charp key, png_charpp new_key));
2646 #if defined(PNG_WRITE_tEXt_SUPPORTED)
2647 PNG_EXTERN void png_write_tEXt PNGARG((png_structp png_ptr, png_charp key,
2648 png_charp text, png_size_t text_len));
2651 #if defined(PNG_WRITE_zTXt_SUPPORTED)
2652 PNG_EXTERN void png_write_zTXt PNGARG((png_structp png_ptr, png_charp key,
2653 png_charp text, png_size_t text_len, int compression));
2656 #if defined(PNG_WRITE_iTXt_SUPPORTED)
2657 PNG_EXTERN void png_write_iTXt PNGARG((png_structp png_ptr,
2658 int compression, png_charp key, png_charp lang, png_charp lang_key,
2662 #if defined(PNG_WRITE_oFFs_SUPPORTED)
2663 PNG_EXTERN void png_write_oFFs PNGARG((png_structp png_ptr,
2664 png_uint_32 x_offset, png_uint_32 y_offset, int unit_type));
2667 #if defined(PNG_WRITE_pCAL_SUPPORTED)
2668 PNG_EXTERN void png_write_pCAL PNGARG((png_structp png_ptr, png_charp purpose,
2669 png_int_32 X0, png_int_32 X1, int type, int nparams,
2670 png_charp units, png_charpp params));
2673 #if defined(PNG_WRITE_pHYs_SUPPORTED)
2674 PNG_EXTERN void png_write_pHYs PNGARG((png_structp png_ptr,
2675 png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit,
2679 #if defined(PNG_WRITE_tIME_SUPPORTED)
2680 PNG_EXTERN void png_write_tIME PNGARG((png_structp png_ptr,
2681 png_timep mod_time));
2684 #if defined(PNG_WRITE_sCAL_SUPPORTED)
2685 #if defined(PNG_FLOATING_POINT_SUPPORTED) && !defined(PNG_NO_STDIO)
2686 PNG_EXTERN void png_write_sCAL PNGARG((png_structp png_ptr,
2687 int unit, double width, double height));
2689 #ifdef PNG_FIXED_POINT_SUPPORTED
2690 PNG_EXTERN void png_write_sCAL_s PNGARG((png_structp png_ptr,
2691 int unit, png_charp width, png_charp height));
2696 /* Called when finished processing a row of data */
2697 PNG_EXTERN void png_write_finish_row PNGARG((png_structp png_ptr));
2699 /* Internal use only. Called before first row of data */
2700 PNG_EXTERN void png_write_start_row PNGARG((png_structp png_ptr));
2702 #if defined(PNG_READ_GAMMA_SUPPORTED)
2703 PNG_EXTERN void png_build_gamma_table PNGARG((png_structp png_ptr));
2706 /* combine a row of data, dealing with alpha, etc. if requested */
2707 PNG_EXTERN void png_combine_row PNGARG((png_structp png_ptr, png_bytep row,
2710 #if defined(PNG_READ_INTERLACING_SUPPORTED)
2711 /* expand an interlaced row */
2713 PNG_EXTERN void png_do_read_interlace PNGARG((png_row_infop row_info,
2714 png_bytep row, int pass, png_uint_32 transformations));
2716 PNG_EXTERN void png_do_read_interlace PNGARG((png_structp png_ptr));
2719 /* GRR TO DO (2.0 or whenever): simplify other internal calling interfaces */
2721 #if defined(PNG_WRITE_INTERLACING_SUPPORTED)
2722 /* grab pixels out of a row for an interlaced pass */
2723 PNG_EXTERN void png_do_write_interlace PNGARG((png_row_infop row_info,
2724 png_bytep row, int pass));
2727 /* unfilter a row */
2728 PNG_EXTERN void png_read_filter_row PNGARG((png_structp png_ptr,
2729 png_row_infop row_info, png_bytep row, png_bytep prev_row, int filter));
2731 /* Choose the best filter to use and filter the row data */
2732 PNG_EXTERN void png_write_find_filter PNGARG((png_structp png_ptr,
2733 png_row_infop row_info));
2735 /* Write out the filtered row. */
2736 PNG_EXTERN void png_write_filtered_row PNGARG((png_structp png_ptr,
2737 png_bytep filtered_row));
2738 /* finish a row while reading, dealing with interlacing passes, etc. */
2739 PNG_EXTERN void png_read_finish_row PNGARG((png_structp png_ptr));
2741 /* initialize the row buffers, etc. */
2742 PNG_EXTERN void png_read_start_row PNGARG((png_structp png_ptr));
2743 /* optional call to update the users info structure */
2744 PNG_EXTERN void png_read_transform_info PNGARG((png_structp png_ptr,
2745 png_infop info_ptr));
2747 /* these are the functions that do the transformations */
2748 #if defined(PNG_READ_FILLER_SUPPORTED)
2749 PNG_EXTERN void png_do_read_filler PNGARG((png_row_infop row_info,
2750 png_bytep row, png_uint_32 filler, png_uint_32 flags));
2753 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED)
2754 PNG_EXTERN void png_do_read_swap_alpha PNGARG((png_row_infop row_info,
2758 #if defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
2759 PNG_EXTERN void png_do_write_swap_alpha PNGARG((png_row_infop row_info,
2763 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)
2764 PNG_EXTERN void png_do_read_invert_alpha PNGARG((png_row_infop row_info,
2768 #if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
2769 PNG_EXTERN void png_do_write_invert_alpha PNGARG((png_row_infop row_info,
2773 #if defined(PNG_WRITE_FILLER_SUPPORTED) || \
2774 defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
2775 PNG_EXTERN void png_do_strip_filler PNGARG((png_row_infop row_info,
2776 png_bytep row, png_uint_32 flags));
2779 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
2780 PNG_EXTERN void png_do_swap PNGARG((png_row_infop row_info, png_bytep row));
2783 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || defined(PNG_WRITE_PACKSWAP_SUPPORTED)
2784 PNG_EXTERN void png_do_packswap PNGARG((png_row_infop row_info, png_bytep row));
2787 #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
2788 PNG_EXTERN int png_do_rgb_to_gray PNGARG((png_structp png_ptr, png_row_infop
2789 row_info, png_bytep row));
2792 #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
2793 PNG_EXTERN void png_do_gray_to_rgb PNGARG((png_row_infop row_info,
2797 #if defined(PNG_READ_PACK_SUPPORTED)
2798 PNG_EXTERN void png_do_unpack PNGARG((png_row_infop row_info, png_bytep row));
2801 #if defined(PNG_READ_SHIFT_SUPPORTED)
2802 PNG_EXTERN void png_do_unshift PNGARG((png_row_infop row_info, png_bytep row,
2803 png_color_8p sig_bits));
2806 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
2807 PNG_EXTERN void png_do_invert PNGARG((png_row_infop row_info, png_bytep row));
2810 #if defined(PNG_READ_16_TO_8_SUPPORTED)
2811 PNG_EXTERN void png_do_chop PNGARG((png_row_infop row_info, png_bytep row));
2814 #if defined(PNG_READ_DITHER_SUPPORTED)
2815 PNG_EXTERN void png_do_dither PNGARG((png_row_infop row_info,
2816 png_bytep row, png_bytep palette_lookup, png_bytep dither_lookup));
2818 # if defined(PNG_CORRECT_PALETTE_SUPPORTED)
2819 PNG_EXTERN void png_correct_palette PNGARG((png_structp png_ptr,
2820 png_colorp palette, int num_palette));
2824 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
2825 PNG_EXTERN void png_do_bgr PNGARG((png_row_infop row_info, png_bytep row));
2828 #if defined(PNG_WRITE_PACK_SUPPORTED)
2829 PNG_EXTERN void png_do_pack PNGARG((png_row_infop row_info,
2830 png_bytep row, png_uint_32 bit_depth));
2833 #if defined(PNG_WRITE_SHIFT_SUPPORTED)
2834 PNG_EXTERN void png_do_shift PNGARG((png_row_infop row_info, png_bytep row,
2835 png_color_8p bit_depth));
2838 #if defined(PNG_READ_BACKGROUND_SUPPORTED)
2839 PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info, png_bytep row,
2840 png_color_16p trans_values, png_color_16p background,
2841 png_color_16p background_1,
2842 png_bytep gamma_table, png_bytep gamma_from_1, png_bytep gamma_to_1,
2843 png_uint_16pp gamma_16, png_uint_16pp gamma_16_from_1,
2844 png_uint_16pp gamma_16_to_1, int gamma_shift));
2847 #if defined(PNG_READ_GAMMA_SUPPORTED)
2848 PNG_EXTERN void png_do_gamma PNGARG((png_row_infop row_info, png_bytep row,
2849 png_bytep gamma_table, png_uint_16pp gamma_16_table,
2853 #if defined(PNG_READ_EXPAND_SUPPORTED)
2854 PNG_EXTERN void png_do_expand_palette PNGARG((png_row_infop row_info,
2855 png_bytep row, png_colorp palette, png_bytep trans, int num_trans));
2856 PNG_EXTERN void png_do_expand PNGARG((png_row_infop row_info,
2857 png_bytep row, png_color_16p trans_value));
2860 /* The following decodes the appropriate chunks, and does error correction,
2861 * then calls the appropriate callback for the chunk if it is valid.
2864 /* decode the IHDR chunk */
2865 PNG_EXTERN void png_handle_IHDR PNGARG((png_structp png_ptr, png_infop info_ptr,
2866 png_uint_32 length));
2867 PNG_EXTERN void png_handle_PLTE PNGARG((png_structp png_ptr, png_infop info_ptr,
2868 png_uint_32 length));
2869 PNG_EXTERN void png_handle_IEND PNGARG((png_structp png_ptr, png_infop info_ptr,
2870 png_uint_32 length));
2872 #if defined(PNG_READ_bKGD_SUPPORTED)
2873 PNG_EXTERN void png_handle_bKGD PNGARG((png_structp png_ptr, png_infop info_ptr,
2874 png_uint_32 length));
2877 #if defined(PNG_READ_cHRM_SUPPORTED)
2878 PNG_EXTERN void png_handle_cHRM PNGARG((png_structp png_ptr, png_infop info_ptr,
2879 png_uint_32 length));
2882 #if defined(PNG_READ_gAMA_SUPPORTED)
2883 PNG_EXTERN void png_handle_gAMA PNGARG((png_structp png_ptr, png_infop info_ptr,
2884 png_uint_32 length));
2887 #if defined(PNG_READ_hIST_SUPPORTED)
2888 PNG_EXTERN void png_handle_hIST PNGARG((png_structp png_ptr, png_infop info_ptr,
2889 png_uint_32 length));
2892 #if defined(PNG_READ_iCCP_SUPPORTED)
2893 extern void png_handle_iCCP PNGARG((png_structp png_ptr, png_infop info_ptr,
2894 png_uint_32 length));
2895 #endif /* PNG_READ_iCCP_SUPPORTED */
2897 #if defined(PNG_READ_iTXt_SUPPORTED)
2898 PNG_EXTERN void png_handle_iTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
2899 png_uint_32 length));
2902 #if defined(PNG_READ_oFFs_SUPPORTED)
2903 PNG_EXTERN void png_handle_oFFs PNGARG((png_structp png_ptr, png_infop info_ptr,
2904 png_uint_32 length));
2907 #if defined(PNG_READ_pCAL_SUPPORTED)
2908 PNG_EXTERN void png_handle_pCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
2909 png_uint_32 length));
2912 #if defined(PNG_READ_pHYs_SUPPORTED)
2913 PNG_EXTERN void png_handle_pHYs PNGARG((png_structp png_ptr, png_infop info_ptr,
2914 png_uint_32 length));
2917 #if defined(PNG_READ_sBIT_SUPPORTED)
2918 PNG_EXTERN void png_handle_sBIT PNGARG((png_structp png_ptr, png_infop info_ptr,
2919 png_uint_32 length));
2922 #if defined(PNG_READ_sCAL_SUPPORTED)
2923 PNG_EXTERN void png_handle_sCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
2924 png_uint_32 length));
2927 #if defined(PNG_READ_sPLT_SUPPORTED)
2928 extern void png_handle_sPLT PNGARG((png_structp png_ptr, png_infop info_ptr,
2929 png_uint_32 length));
2930 #endif /* PNG_READ_sPLT_SUPPORTED */
2932 #if defined(PNG_READ_sRGB_SUPPORTED)
2933 PNG_EXTERN void png_handle_sRGB PNGARG((png_structp png_ptr, png_infop info_ptr,
2934 png_uint_32 length));
2937 #if defined(PNG_READ_tEXt_SUPPORTED)
2938 PNG_EXTERN void png_handle_tEXt PNGARG((png_structp png_ptr, png_infop info_ptr,
2939 png_uint_32 length));
2942 #if defined(PNG_READ_tIME_SUPPORTED)
2943 PNG_EXTERN void png_handle_tIME PNGARG((png_structp png_ptr, png_infop info_ptr,
2944 png_uint_32 length));
2947 #if defined(PNG_READ_tRNS_SUPPORTED)
2948 PNG_EXTERN void png_handle_tRNS PNGARG((png_structp png_ptr, png_infop info_ptr,
2949 png_uint_32 length));
2952 #if defined(PNG_READ_zTXt_SUPPORTED)
2953 PNG_EXTERN void png_handle_zTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
2954 png_uint_32 length));
2957 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
2958 PNG_EXTERN int png_handle_as_unknown PNGARG((png_structp png_ptr, png_bytep
2962 PNG_EXTERN void png_handle_unknown PNGARG((png_structp png_ptr,
2963 png_infop info_ptr, png_uint_32 length));
2965 PNG_EXTERN void png_check_chunk_name PNGARG((png_structp png_ptr,
2966 png_bytep chunk_name));
2968 /* handle the transformations for reading and writing */
2969 PNG_EXTERN void png_do_read_transformations PNGARG((png_structp png_ptr));
2970 PNG_EXTERN void png_do_write_transformations PNGARG((png_structp png_ptr));
2972 PNG_EXTERN void png_init_read_transformations PNGARG((png_structp png_ptr));
2974 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
2975 PNG_EXTERN void png_push_read_chunk PNGARG((png_structp png_ptr,
2976 png_infop info_ptr));
2977 PNG_EXTERN void png_push_read_sig PNGARG((png_structp png_ptr,
2978 png_infop info_ptr));
2979 PNG_EXTERN void png_push_check_crc PNGARG((png_structp png_ptr));
2980 PNG_EXTERN void png_push_crc_skip PNGARG((png_structp png_ptr,
2981 png_uint_32 length));
2982 PNG_EXTERN void png_push_crc_finish PNGARG((png_structp png_ptr));
2983 PNG_EXTERN void png_push_fill_buffer PNGARG((png_structp png_ptr,
2984 png_bytep buffer, png_size_t length));
2985 PNG_EXTERN void png_push_save_buffer PNGARG((png_structp png_ptr));
2986 PNG_EXTERN void png_push_restore_buffer PNGARG((png_structp png_ptr,
2987 png_bytep buffer, png_size_t buffer_length));
2988 PNG_EXTERN void png_push_read_IDAT PNGARG((png_structp png_ptr));
2989 PNG_EXTERN void png_process_IDAT_data PNGARG((png_structp png_ptr,
2990 png_bytep buffer, png_size_t buffer_length));
2991 PNG_EXTERN void png_push_process_row PNGARG((png_structp png_ptr));
2992 PNG_EXTERN void png_push_handle_unknown PNGARG((png_structp png_ptr,
2993 png_infop info_ptr, png_uint_32 length));
2994 PNG_EXTERN void png_push_have_info PNGARG((png_structp png_ptr,
2995 png_infop info_ptr));
2996 PNG_EXTERN void png_push_have_end PNGARG((png_structp png_ptr,
2997 png_infop info_ptr));
2998 PNG_EXTERN void png_push_have_row PNGARG((png_structp png_ptr, png_bytep row));
2999 PNG_EXTERN void png_push_read_end PNGARG((png_structp png_ptr,
3000 png_infop info_ptr));
3001 PNG_EXTERN void png_process_some_data PNGARG((png_structp png_ptr,
3002 png_infop info_ptr));
3003 PNG_EXTERN void png_read_push_finish_row PNGARG((png_structp png_ptr));
3004 #if defined(PNG_READ_tEXt_SUPPORTED)
3005 PNG_EXTERN void png_push_handle_tEXt PNGARG((png_structp png_ptr,
3006 png_infop info_ptr, png_uint_32 length));
3007 PNG_EXTERN void png_push_read_tEXt PNGARG((png_structp png_ptr,
3008 png_infop info_ptr));
3010 #if defined(PNG_READ_zTXt_SUPPORTED)
3011 PNG_EXTERN void png_push_handle_zTXt PNGARG((png_structp png_ptr,
3012 png_infop info_ptr, png_uint_32 length));
3013 PNG_EXTERN void png_push_read_zTXt PNGARG((png_structp png_ptr,
3014 png_infop info_ptr));
3016 #if defined(PNG_READ_iTXt_SUPPORTED)
3017 PNG_EXTERN void png_push_handle_iTXt PNGARG((png_structp png_ptr,
3018 png_infop info_ptr, png_uint_32 length));
3019 PNG_EXTERN void png_push_read_iTXt PNGARG((png_structp png_ptr,
3020 png_infop info_ptr));
3023 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
3025 #ifdef PNG_MNG_FEATURES_SUPPORTED
3026 PNG_EXTERN void png_do_read_intrapixel PNGARG((png_row_infop row_info,
3028 PNG_EXTERN void png_do_write_intrapixel PNGARG((png_row_infop row_info,
3032 /* Maintainer: Put new private prototypes here ^ and in libpngpf.3 */
3034 #endif /* PNG_INTERNAL */
3040 #endif /* PNG_VERSION_INFO_ONLY */
3041 /* do not put anything past this line */