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1/* pngpriv.h - private declarations for use inside libpng
2 *
3 * For conditions of distribution and use, see copyright notice in png.h
4 * Copyright (c) 1998-2011 Glenn Randers-Pehrson
5 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
6 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
7 *
8 * Last changed in libpng 1.5.6 [November 3, 2011]
9 *
10 * This code is released under the libpng license.
11 * For conditions of distribution and use, see the disclaimer
12 * and license in png.h
13 */
14
15/* The symbols declared in this file (including the functions declared
16 * as PNG_EXTERN) are PRIVATE. They are not part of the libpng public
17 * interface, and are not recommended for use by regular applications.
18 * Some of them may become public in the future; others may stay private,
19 * change in an incompatible way, or even disappear.
20 * Although the libpng users are not forbidden to include this header,
21 * they should be well aware of the issues that may arise from doing so.
22 */
23
24#ifndef PNGPRIV_H
25#define PNGPRIV_H
26
27/* Feature Test Macros. The following are defined here to ensure that correctly
28 * implemented libraries reveal the APIs libpng needs to build and hide those
29 * that are not needed and potentially damaging to the compilation.
30 *
31 * Feature Test Macros must be defined before any system header is included (see
32 * POSIX 1003.1 2.8.2 "POSIX Symbols."
33 *
34 * These macros only have an effect if the operating system supports either
35 * POSIX 1003.1 or C99, or both. On other operating systems (particularly
36 * Windows/Visual Studio) there is no effect; the OS specific tests below are
37 * still required (as of 2011-05-02.)
38 */
39#define _POSIX_SOURCE 1 /* Just the POSIX 1003.1 and C89 APIs */
40
41/* This is required for the definition of abort(), used as a last ditch
42 * error handler when all else fails.
43 */
44#include <stdlib.h>
45
46/* This is used to find 'offsetof', used below for alignment tests. */
47#include <stddef.h>
48
49#define PNGLIB_BUILD /*libpng is being built, not used*/
50
51#ifdef PNG_USER_CONFIG
52# include "pngusr.h"
53 /* These should have been defined in pngusr.h */
54# ifndef PNG_USER_PRIVATEBUILD
55# define PNG_USER_PRIVATEBUILD "Custom libpng build"
56# endif
57# ifndef PNG_USER_DLLFNAME_POSTFIX
58# define PNG_USER_DLLFNAME_POSTFIX "Cb"
59# endif
60#endif
61
62/* Is this a build of a DLL where compilation of the object modules requires
63 * different preprocessor settings to those required for a simple library? If
64 * so PNG_BUILD_DLL must be set.
65 *
66 * If libpng is used inside a DLL but that DLL does not export the libpng APIs
67 * PNG_BUILD_DLL must not be set. To avoid the code below kicking in build a
68 * static library of libpng then link the DLL against that.
69 */
70#ifndef PNG_BUILD_DLL
71# ifdef DLL_EXPORT
72 /* This is set by libtool when files are compiled for a DLL; libtool
73 * always compiles twice, even on systems where it isn't necessary. Set
74 * PNG_BUILD_DLL in case it is necessary:
75 */
76# define PNG_BUILD_DLL
77# else
78# ifdef _WINDLL
79 /* This is set by the Microsoft Visual Studio IDE in projects that
80 * build a DLL. It can't easily be removed from those projects (it
81 * isn't visible in the Visual Studio UI) so it is a fairly reliable
82 * indication that PNG_IMPEXP needs to be set to the DLL export
83 * attributes.
84 */
85# define PNG_BUILD_DLL
86# else
87# ifdef __DLL__
88 /* This is set by the Borland C system when compiling for a DLL
89 * (as above.)
90 */
91# define PNG_BUILD_DLL
92# else
93 /* Add additional compiler cases here. */
94# endif
95# endif
96# endif
97#endif /* Setting PNG_BUILD_DLL if required */
98
99/* See pngconf.h for more details: the builder of the library may set this on
100 * the command line to the right thing for the specific compilation system or it
101 * may be automagically set above (at present we know of no system where it does
102 * need to be set on the command line.)
103 *
104 * PNG_IMPEXP must be set here when building the library to prevent pngconf.h
105 * setting it to the "import" setting for a DLL build.
106 */
107#ifndef PNG_IMPEXP
108# ifdef PNG_BUILD_DLL
109# define PNG_IMPEXP PNG_DLL_EXPORT
110# else
111 /* Not building a DLL, or the DLL doesn't require specific export
112 * definitions.
113 */
114# define PNG_IMPEXP
115# endif
116#endif
117
118/* No warnings for private or deprecated functions in the build: */
119#ifndef PNG_DEPRECATED
120# define PNG_DEPRECATED
121#endif
122#ifndef PNG_PRIVATE
123# define PNG_PRIVATE
124#endif
125
126#include "png.h"
127#include "pnginfo.h"
128#include "pngstruct.h"
129
130/* pngconf.h does not set PNG_DLL_EXPORT unless it is required, so: */
131#ifndef PNG_DLL_EXPORT
132# define PNG_DLL_EXPORT
133#endif
134
135/* This is used for 16 bit gamma tables - only the top level pointers are const,
136 * this could be changed:
137 */
138typedef PNG_CONST png_uint_16p FAR * png_const_uint_16pp;
139
140/* Added at libpng-1.2.9 */
141/* Moved to pngpriv.h at libpng-1.5.0 */
142
143/* config.h is created by and PNG_CONFIGURE_LIBPNG is set by the "configure"
144 * script. We may need it here to get the correct configuration on things
145 * like limits.
146 */
147#ifdef PNG_CONFIGURE_LIBPNG
148# ifdef HAVE_CONFIG_H
149# include "config.h"
150# endif
151#endif
152
153/* Moved to pngpriv.h at libpng-1.5.0 */
154/* NOTE: some of these may have been used in external applications as
155 * these definitions were exposed in pngconf.h prior to 1.5.
156 */
157
158/* If you are running on a machine where you cannot allocate more
159 * than 64K of memory at once, uncomment this. While libpng will not
160 * normally need that much memory in a chunk (unless you load up a very
161 * large file), zlib needs to know how big of a chunk it can use, and
162 * libpng thus makes sure to check any memory allocation to verify it
163 * will fit into memory.
164 *
165 * zlib provides 'MAXSEG_64K' which, if defined, indicates the
166 * same limit and pngconf.h (already included) sets the limit
167 * if certain operating systems are detected.
168 */
169#if defined(MAXSEG_64K) && !defined(PNG_MAX_MALLOC_64K)
170# define PNG_MAX_MALLOC_64K
171#endif
172
173#ifndef PNG_UNUSED
174/* Unused formal parameter warnings are silenced using the following macro
175 * which is expected to have no bad effects on performance (optimizing
176 * compilers will probably remove it entirely). Note that if you replace
177 * it with something other than whitespace, you must include the terminating
178 * semicolon.
179 */
180# define PNG_UNUSED(param) (void)param;
181#endif
182
183/* Just a little check that someone hasn't tried to define something
184 * contradictory.
185 */
186#if (PNG_ZBUF_SIZE > 65536L) && defined(PNG_MAX_MALLOC_64K)
187# undef PNG_ZBUF_SIZE
188# define PNG_ZBUF_SIZE 65536L
189#endif
190
191/* PNG_STATIC is used to mark internal file scope functions if they need to be
192 * accessed for implementation tests (see the code in tests/?*).
193 */
194#ifndef PNG_STATIC
195# define PNG_STATIC static
196#endif
197
198/* If warnings or errors are turned off the code is disabled or redirected here.
199 * From 1.5.4 functions have been added to allow very limited formatting of
200 * error and warning messages - this code will also be disabled here.
201 */
202#ifdef PNG_WARNINGS_SUPPORTED
203# define PNG_WARNING_PARAMETERS(p) png_warning_parameters p;
204#else
205# define png_warning(s1,s2) ((void)(s1))
206# define png_chunk_warning(s1,s2) ((void)(s1))
207# define png_warning_parameter(p,number,string) ((void)0)
208# define png_warning_parameter_unsigned(p,number,format,value) ((void)0)
209# define png_warning_parameter_signed(p,number,format,value) ((void)0)
210# define png_formatted_warning(pp,p,message) ((void)(pp))
211# define PNG_WARNING_PARAMETERS(p)
212#endif
213#ifndef PNG_ERROR_TEXT_SUPPORTED
214# define png_error(s1,s2) png_err(s1)
215# define png_chunk_error(s1,s2) png_err(s1)
216# define png_fixed_error(s1,s2) png_err(s1)
217#endif
218
219#ifndef PNG_EXTERN
220/* The functions exported by PNG_EXTERN are internal functions, which
221 * aren't usually used outside the library (as far as I know), so it is
222 * debatable if they should be exported at all. In the future, when it
223 * is possible to have run-time registry of chunk-handling functions,
224 * some of these might be made available again.
225# define PNG_EXTERN extern
226 */
227# define PNG_EXTERN
228#endif
229
230/* Some fixed point APIs are still required even if not exported because
231 * they get used by the corresponding floating point APIs. This magic
232 * deals with this:
233 */
234#ifdef PNG_FIXED_POINT_SUPPORTED
235# define PNGFAPI PNGAPI
236#else
237# define PNGFAPI /* PRIVATE */
238#endif
239
240/* Other defines specific to compilers can go here. Try to keep
241 * them inside an appropriate ifdef/endif pair for portability.
242 */
243#if defined(PNG_FLOATING_POINT_SUPPORTED) ||\
244 defined(PNG_FLOATING_ARITHMETIC_SUPPORTED)
245 /* png.c requires the following ANSI-C constants if the conversion of
246 * floating point to ASCII is implemented therein:
247 *
248 * DBL_DIG Maximum number of decimal digits (can be set to any constant)
249 * DBL_MIN Smallest normalized fp number (can be set to an arbitrary value)
250 * DBL_MAX Maximum floating point number (can be set to an arbitrary value)
251 */
252# include <float.h>
253
254# if ( ( (defined(__MWERKS__) && defined(macintosh)) || defined(applec) || \
255 defined(THINK_C) || defined(TARGET_OS_MAC) ) && !wxOSX_USE_IPHONE ) || defined(__SC__)
256 /* We need to check that <math.h> hasn't already been included earlier
257 * as it seems it doesn't agree with <fp.h>, yet we should really use
258 * <fp.h> if possible.
259 */
260# if !defined(__MATH_H__) && !defined(__MATH_H) && !defined(__cmath__)
261# include <fp.h>
262# endif
263# else
264# include <math.h>
265# endif
266# if defined(_AMIGA) && defined(__SASC) && defined(_M68881)
267 /* Amiga SAS/C: We must include builtin FPU functions when compiling using
268 * MATH=68881
269 */
270# include <m68881.h>
271# endif
272#endif
273
274/* This provides the non-ANSI (far) memory allocation routines. */
275#if defined(__TURBOC__) && defined(__MSDOS__)
276# include <mem.h>
277# include <alloc.h>
278#endif
279
280#if defined(WIN32) || defined(_Windows) || defined(_WINDOWS) || \
281 defined(_WIN32) || defined(__WIN32__)
282# include <windows.h> /* defines _WINDOWS_ macro */
283#endif
284
285/* Moved here around 1.5.0beta36 from pngconf.h */
286/* Users may want to use these so they are not private. Any library
287 * functions that are passed far data must be model-independent.
288 */
289
290/* Memory model/platform independent fns */
291#ifndef PNG_ABORT
292# ifdef _WINDOWS_
293# define PNG_ABORT() ExitProcess(0)
294# else
295# define PNG_ABORT() abort()
296# endif
297#endif
298
299#ifdef USE_FAR_KEYWORD
300/* Use this to make far-to-near assignments */
301# define CHECK 1
302# define NOCHECK 0
303# define CVT_PTR(ptr) (png_far_to_near(png_ptr,ptr,CHECK))
304# define CVT_PTR_NOCHECK(ptr) (png_far_to_near(png_ptr,ptr,NOCHECK))
305# define png_strlen _fstrlen
306# define png_memcmp _fmemcmp /* SJT: added */
307# define png_memcpy _fmemcpy
308# define png_memset _fmemset
309#else
310# ifdef _WINDOWS_ /* Favor Windows over C runtime fns */
311# define CVT_PTR(ptr) (ptr)
312# define CVT_PTR_NOCHECK(ptr) (ptr)
313# define png_strlen lstrlenA
314# define png_memcmp memcmp
315# define png_memcpy CopyMemory
316# define png_memset memset
317# else
318# define CVT_PTR(ptr) (ptr)
319# define CVT_PTR_NOCHECK(ptr) (ptr)
320# define png_strlen strlen
321# define png_memcmp memcmp /* SJT: added */
322# define png_memcpy memcpy
323# define png_memset memset
324# endif
325#endif
326
327/* These macros may need to be architecture dependent. */
328#define PNG_ALIGN_NONE 0 /* do not use data alignment */
329#define PNG_ALIGN_ALWAYS 1 /* assume unaligned accesses are OK */
330#ifdef offsetof
331# define PNG_ALIGN_OFFSET 2 /* use offsetof to determine alignment */
332#else
333# define PNG_ALIGN_OFFSET -1 /* prevent the use of this */
334#endif
335#define PNG_ALIGN_SIZE 3 /* use sizeof to determine alignment */
336
337#ifndef PNG_ALIGN_TYPE
338 /* Default to using aligned access optimizations and requiring alignment to a
339 * multiple of the data type size. Override in a compiler specific fashion
340 * if necessary by inserting tests here:
341 */
342# define PNG_ALIGN_TYPE PNG_ALIGN_SIZE
343#endif
344
345#if PNG_ALIGN_TYPE == PNG_ALIGN_SIZE
346 /* This is used because in some compiler implementations non-aligned
347 * structure members are supported, so the offsetof approach below fails.
348 * Set PNG_ALIGN_TO_SIZE=0 for compiler combinations where unaligned access
349 * is good for performance. Do not do this unless you have tested the result
350 * and understand it.
351 */
352# define png_alignof(type) (sizeof (type))
353#else
354# if PNG_ALIGN_TYPE == PNG_ALIGN_OFFSET
355# define png_alignof(type) offsetof(struct{char c; type t;}, t)
356# else
357# if PNG_ALIGN_TYPE == PNG_ALIGN_ALWAYS
358# define png_alignof(type) (1)
359# endif
360 /* Else leave png_alignof undefined to prevent use thereof */
361# endif
362#endif
363
364/* This implicitly assumes alignment is always to a power of 2. */
365#ifdef png_alignof
366# define png_isaligned(ptr, type)\
367 ((((const char*)ptr-(const char*)0) & (png_alignof(type)-1)) == 0)
368#else
369# define png_isaligned(ptr, type) 0
370#endif
371
372/* End of memory model/platform independent support */
373/* End of 1.5.0beta36 move from pngconf.h */
374
375/* CONSTANTS and UTILITY MACROS
376 * These are used internally by libpng and not exposed in the API
377 */
378
379/* Various modes of operation. Note that after an init, mode is set to
380 * zero automatically when the structure is created. Three of these
381 * are defined in png.h because they need to be visible to applications
382 * that call png_set_unknown_chunk().
383 */
384/* #define PNG_HAVE_IHDR 0x01 (defined in png.h) */
385/* #define PNG_HAVE_PLTE 0x02 (defined in png.h) */
386#define PNG_HAVE_IDAT 0x04
387/* #define PNG_AFTER_IDAT 0x08 (defined in png.h) */
388#define PNG_HAVE_IEND 0x10
389#define PNG_HAVE_gAMA 0x20
390#define PNG_HAVE_cHRM 0x40
391#define PNG_HAVE_sRGB 0x80
392#define PNG_HAVE_CHUNK_HEADER 0x100
393#define PNG_WROTE_tIME 0x200
394#define PNG_WROTE_INFO_BEFORE_PLTE 0x400
395#define PNG_BACKGROUND_IS_GRAY 0x800
396#define PNG_HAVE_PNG_SIGNATURE 0x1000
397#define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000 /* Have another chunk after IDAT */
398
399/* Flags for the transformations the PNG library does on the image data */
400#define PNG_BGR 0x0001
401#define PNG_INTERLACE 0x0002
402#define PNG_PACK 0x0004
403#define PNG_SHIFT 0x0008
404#define PNG_SWAP_BYTES 0x0010
405#define PNG_INVERT_MONO 0x0020
406#define PNG_QUANTIZE 0x0040
407#define PNG_COMPOSE 0x0080 /* Was PNG_BACKGROUND */
408#define PNG_BACKGROUND_EXPAND 0x0100
409#define PNG_EXPAND_16 0x0200 /* Added to libpng 1.5.2 */
410#define PNG_16_TO_8 0x0400 /* Becomes 'chop' in 1.5.4 */
411#define PNG_RGBA 0x0800
412#define PNG_EXPAND 0x1000
413#define PNG_GAMMA 0x2000
414#define PNG_GRAY_TO_RGB 0x4000
415#define PNG_FILLER 0x8000
416#define PNG_PACKSWAP 0x10000
417#define PNG_SWAP_ALPHA 0x20000
418#define PNG_STRIP_ALPHA 0x40000
419#define PNG_INVERT_ALPHA 0x80000
420#define PNG_USER_TRANSFORM 0x100000
421#define PNG_RGB_TO_GRAY_ERR 0x200000
422#define PNG_RGB_TO_GRAY_WARN 0x400000
423#define PNG_RGB_TO_GRAY 0x600000 /* two bits, RGB_TO_GRAY_ERR|WARN */
424#define PNG_ENCODE_ALPHA 0x800000 /* Added to libpng-1.5.4 */
425#define PNG_ADD_ALPHA 0x1000000 /* Added to libpng-1.2.7 */
426#define PNG_EXPAND_tRNS 0x2000000 /* Added to libpng-1.2.9 */
427#define PNG_SCALE_16_TO_8 0x4000000 /* Added to libpng-1.5.4 */
428 /* 0x8000000 unused */
429 /* 0x10000000 unused */
430 /* 0x20000000 unused */
431 /* 0x40000000 unused */
432/* Flags for png_create_struct */
433#define PNG_STRUCT_PNG 0x0001
434#define PNG_STRUCT_INFO 0x0002
435
436/* Scaling factor for filter heuristic weighting calculations */
437#define PNG_WEIGHT_FACTOR (1<<(PNG_WEIGHT_SHIFT))
438#define PNG_COST_FACTOR (1<<(PNG_COST_SHIFT))
439
440/* Flags for the png_ptr->flags rather than declaring a byte for each one */
441#define PNG_FLAG_ZLIB_CUSTOM_STRATEGY 0x0001
442#define PNG_FLAG_ZLIB_CUSTOM_LEVEL 0x0002
443#define PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL 0x0004
444#define PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS 0x0008
445#define PNG_FLAG_ZLIB_CUSTOM_METHOD 0x0010
446#define PNG_FLAG_ZLIB_FINISHED 0x0020
447#define PNG_FLAG_ROW_INIT 0x0040
448#define PNG_FLAG_FILLER_AFTER 0x0080
449#define PNG_FLAG_CRC_ANCILLARY_USE 0x0100
450#define PNG_FLAG_CRC_ANCILLARY_NOWARN 0x0200
451#define PNG_FLAG_CRC_CRITICAL_USE 0x0400
452#define PNG_FLAG_CRC_CRITICAL_IGNORE 0x0800
453#define PNG_FLAG_ASSUME_sRGB 0x1000 /* Added to libpng-1.5.4 */
454#define PNG_FLAG_OPTIMIZE_ALPHA 0x2000 /* Added to libpng-1.5.4 */
455#define PNG_FLAG_DETECT_UNINITIALIZED 0x4000 /* Added to libpng-1.5.4 */
456#define PNG_FLAG_KEEP_UNKNOWN_CHUNKS 0x8000
457#define PNG_FLAG_KEEP_UNSAFE_CHUNKS 0x10000
458#define PNG_FLAG_LIBRARY_MISMATCH 0x20000
459#define PNG_FLAG_STRIP_ERROR_NUMBERS 0x40000
460#define PNG_FLAG_STRIP_ERROR_TEXT 0x80000
461#define PNG_FLAG_MALLOC_NULL_MEM_OK 0x100000
462 /* 0x200000 unused */
463 /* 0x400000 unused */
464#define PNG_FLAG_BENIGN_ERRORS_WARN 0x800000 /* Added to libpng-1.4.0 */
465#define PNG_FLAG_ZTXT_CUSTOM_STRATEGY 0x1000000 /* 5 lines added */
466#define PNG_FLAG_ZTXT_CUSTOM_LEVEL 0x2000000 /* to libpng-1.5.4 */
467#define PNG_FLAG_ZTXT_CUSTOM_MEM_LEVEL 0x4000000
468#define PNG_FLAG_ZTXT_CUSTOM_WINDOW_BITS 0x8000000
469#define PNG_FLAG_ZTXT_CUSTOM_METHOD 0x10000000
470 /* 0x20000000 unused */
471 /* 0x40000000 unused */
472
473#define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \
474 PNG_FLAG_CRC_ANCILLARY_NOWARN)
475
476#define PNG_FLAG_CRC_CRITICAL_MASK (PNG_FLAG_CRC_CRITICAL_USE | \
477 PNG_FLAG_CRC_CRITICAL_IGNORE)
478
479#define PNG_FLAG_CRC_MASK (PNG_FLAG_CRC_ANCILLARY_MASK | \
480 PNG_FLAG_CRC_CRITICAL_MASK)
481
482/* zlib.h declares a magic type 'uInt' that limits the amount of data that zlib
483 * can handle at once. This type need be no larger than 16 bits (so maximum of
484 * 65535), this define allows us to discover how big it is, but limited by the
485 * maximuum for png_size_t. The value can be overriden in a library build
486 * (pngusr.h, or set it in CPPFLAGS) and it works to set it to a considerably
487 * lower value (e.g. 255 works). A lower value may help memory usage (slightly)
488 * and may even improve performance on some systems (and degrade it on others.)
489 */
490#ifndef ZLIB_IO_MAX
491# define ZLIB_IO_MAX ((uInt)-1)
492#endif
493
494/* Save typing and make code easier to understand */
495
496#define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \
497 abs((int)((c1).green) - (int)((c2).green)) + \
498 abs((int)((c1).blue) - (int)((c2).blue)))
499
500/* Added to libpng-1.2.6 JB */
501#define PNG_ROWBYTES(pixel_bits, width) \
502 ((pixel_bits) >= 8 ? \
503 ((png_size_t)(width) * (((png_size_t)(pixel_bits)) >> 3)) : \
504 (( ((png_size_t)(width) * ((png_size_t)(pixel_bits))) + 7) >> 3) )
505
506/* PNG_OUT_OF_RANGE returns true if value is outside the range
507 * ideal-delta..ideal+delta. Each argument is evaluated twice.
508 * "ideal" and "delta" should be constants, normally simple
509 * integers, "value" a variable. Added to libpng-1.2.6 JB
510 */
511#define PNG_OUT_OF_RANGE(value, ideal, delta) \
512 ( (value) < (ideal)-(delta) || (value) > (ideal)+(delta) )
513
514/* Conversions between fixed and floating point, only defined if
515 * required (to make sure the code doesn't accidentally use float
516 * when it is supposedly disabled.)
517 */
518#ifdef PNG_FLOATING_POINT_SUPPORTED
519/* The floating point conversion can't overflow, though it can and
520 * does lose accuracy relative to the original fixed point value.
521 * In practice this doesn't matter because png_fixed_point only
522 * stores numbers with very low precision. The png_ptr and s
523 * arguments are unused by default but are there in case error
524 * checking becomes a requirement.
525 */
526#define png_float(png_ptr, fixed, s) (.00001 * (fixed))
527
528/* The fixed point conversion performs range checking and evaluates
529 * its argument multiple times, so must be used with care. The
530 * range checking uses the PNG specification values for a signed
531 * 32 bit fixed point value except that the values are deliberately
532 * rounded-to-zero to an integral value - 21474 (21474.83 is roughly
533 * (2^31-1) * 100000). 's' is a string that describes the value being
534 * converted.
535 *
536 * NOTE: this macro will raise a png_error if the range check fails,
537 * therefore it is normally only appropriate to use this on values
538 * that come from API calls or other sources where an out of range
539 * error indicates a programming error, not a data error!
540 *
541 * NOTE: by default this is off - the macro is not used - because the
542 * function call saves a lot of code.
543 */
544#ifdef PNG_FIXED_POINT_MACRO_SUPPORTED
545#define png_fixed(png_ptr, fp, s) ((fp) <= 21474 && (fp) >= -21474 ?\
546 ((png_fixed_point)(100000 * (fp))) : (png_fixed_error(png_ptr, s),0))
547#else
548PNG_EXTERN png_fixed_point png_fixed PNGARG((png_structp png_ptr, double fp,
549 png_const_charp text));
550#endif
551#endif
552
553/* Constants for known chunk types. If you need to add a chunk, define the name
554 * here. For historical reasons these constants have the form png_<name>; i.e.
555 * the prefix is lower case. Please use decimal values as the parameters to
556 * match the ISO PNG specification and to avoid relying on the C locale
557 * interpretation of character values.
558 *
559 * Prior to 1.5.6 these constants were strings, as of 1.5.6 png_uint_32 values
560 * are computed and a new macro (PNG_STRING_FROM_CHUNK) added to allow a string
561 * to be generated if required.
562 *
563 * PNG_32b correctly produces a value shifted by up to 24 bits, even on
564 * architectures where (int) is only 16 bits.
565 */
566#define PNG_32b(b,s) ((png_uint_32)(b) << (s))
567#define PNG_CHUNK(b1,b2,b3,b4) \
568 (PNG_32b(b1,24) | PNG_32b(b2,16) | PNG_32b(b3,8) | PNG_32b(b4,0))
569
570#define png_IHDR PNG_CHUNK( 73, 72, 68, 82)
571#define png_IDAT PNG_CHUNK( 73, 68, 65, 84)
572#define png_IEND PNG_CHUNK( 73, 69, 78, 68)
573#define png_PLTE PNG_CHUNK( 80, 76, 84, 69)
574#define png_bKGD PNG_CHUNK( 98, 75, 71, 68)
575#define png_cHRM PNG_CHUNK( 99, 72, 82, 77)
576#define png_gAMA PNG_CHUNK(103, 65, 77, 65)
577#define png_hIST PNG_CHUNK(104, 73, 83, 84)
578#define png_iCCP PNG_CHUNK(105, 67, 67, 80)
579#define png_iTXt PNG_CHUNK(105, 84, 88, 116)
580#define png_oFFs PNG_CHUNK(111, 70, 70, 115)
581#define png_pCAL PNG_CHUNK(112, 67, 65, 76)
582#define png_sCAL PNG_CHUNK(115, 67, 65, 76)
583#define png_pHYs PNG_CHUNK(112, 72, 89, 115)
584#define png_sBIT PNG_CHUNK(115, 66, 73, 84)
585#define png_sPLT PNG_CHUNK(115, 80, 76, 84)
586#define png_sRGB PNG_CHUNK(115, 82, 71, 66)
587#define png_sTER PNG_CHUNK(115, 84, 69, 82)
588#define png_tEXt PNG_CHUNK(116, 69, 88, 116)
589#define png_tIME PNG_CHUNK(116, 73, 77, 69)
590#define png_tRNS PNG_CHUNK(116, 82, 78, 83)
591#define png_zTXt PNG_CHUNK(122, 84, 88, 116)
592
593/* The following will work on (signed char*) strings, whereas the get_uint_32
594 * macro will fail on top-bit-set values because of the sign extension.
595 */
596#define PNG_CHUNK_FROM_STRING(s)\
597 PNG_CHUNK(0xff&(s)[0], 0xff&(s)[1], 0xff&(s)[2], 0xff&(s)[3])
598
599/* This uses (char), not (png_byte) to avoid warnings on systems where (char) is
600 * signed and the argument is a (char[]) This macro will fail miserably on
601 * systems where (char) is more than 8 bits.
602 */
603#define PNG_STRING_FROM_CHUNK(s,c)\
604 (void)(((char*)(s))[0]=(char)((c)>>24), ((char*)(s))[1]=(char)((c)>>16),\
605 ((char*)(s))[2]=(char)((c)>>8), ((char*)(s))[3]=(char)((c)))
606
607/* Do the same but terminate with a null character. */
608#define PNG_CSTRING_FROM_CHUNK(s,c)\
609 (void)(PNG_STRING_FROM_CHUNK(s,c), ((char*)(s))[4] = 0)
610
611/* Test on flag values as defined in the spec (section 5.4): */
612#define PNG_CHUNK_ANCILLIARY(c) (1 & ((c) >> 29))
613#define PNG_CHUNK_CRITICAL(c) (!PNG_CHUNK_ANCILLIARY(c))
614#define PNG_CHUNK_PRIVATE(c) (1 & ((c) >> 21))
615#define PNG_CHUNK_RESERVED(c) (1 & ((c) >> 13))
616#define PNG_CHUNK_SAFE_TO_COPY(c) (1 & ((c) >> 5))
617
618/* Gamma values (new at libpng-1.5.4): */
619#define PNG_GAMMA_MAC_OLD 151724 /* Assume '1.8' is really 2.2/1.45! */
620#define PNG_GAMMA_MAC_INVERSE 65909
621#define PNG_GAMMA_sRGB_INVERSE 45455
622
623
624/* Inhibit C++ name-mangling for libpng functions but not for system calls. */
625#ifdef __cplusplus
626extern "C" {
627#endif /* __cplusplus */
628
629/* These functions are used internally in the code. They generally
630 * shouldn't be used unless you are writing code to add or replace some
631 * functionality in libpng. More information about most functions can
632 * be found in the files where the functions are located.
633 */
634
635/* Check the user version string for compatibility, returns false if the version
636 * numbers aren't compatible.
637 */
638PNG_EXTERN int png_user_version_check(png_structp png_ptr,
639 png_const_charp user_png_ver);
640
641/* Allocate memory for an internal libpng struct */
642PNG_EXTERN PNG_FUNCTION(png_voidp,png_create_struct,PNGARG((int type)),
643 PNG_ALLOCATED);
644
645/* Free memory from internal libpng struct */
646PNG_EXTERN void png_destroy_struct PNGARG((png_voidp struct_ptr));
647
648PNG_EXTERN PNG_FUNCTION(png_voidp,png_create_struct_2,
649 PNGARG((int type, png_malloc_ptr malloc_fn, png_voidp mem_ptr)),
650 PNG_ALLOCATED);
651PNG_EXTERN void png_destroy_struct_2 PNGARG((png_voidp struct_ptr,
652 png_free_ptr free_fn, png_voidp mem_ptr));
653
654/* Free any memory that info_ptr points to and reset struct. */
655PNG_EXTERN void png_info_destroy PNGARG((png_structp png_ptr,
656 png_infop info_ptr));
657
658/* Function to allocate memory for zlib. PNGAPI is disallowed. */
659PNG_EXTERN PNG_FUNCTION(voidpf,png_zalloc,PNGARG((voidpf png_ptr, uInt items,
660 uInt size)),PNG_ALLOCATED);
661
662/* Function to free memory for zlib. PNGAPI is disallowed. */
663PNG_EXTERN void png_zfree PNGARG((voidpf png_ptr, voidpf ptr));
664
665/* Next four functions are used internally as callbacks. PNGCBAPI is required
666 * but not PNG_EXPORT. PNGAPI added at libpng version 1.2.3, changed to
667 * PNGCBAPI at 1.5.0
668 */
669
670PNG_EXTERN void PNGCBAPI png_default_read_data PNGARG((png_structp png_ptr,
671 png_bytep data, png_size_t length));
672
673#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
674PNG_EXTERN void PNGCBAPI png_push_fill_buffer PNGARG((png_structp png_ptr,
675 png_bytep buffer, png_size_t length));
676#endif
677
678PNG_EXTERN void PNGCBAPI png_default_write_data PNGARG((png_structp png_ptr,
679 png_bytep data, png_size_t length));
680
681#ifdef PNG_WRITE_FLUSH_SUPPORTED
682# ifdef PNG_STDIO_SUPPORTED
683PNG_EXTERN void PNGCBAPI png_default_flush PNGARG((png_structp png_ptr));
684# endif
685#endif
686
687/* Reset the CRC variable */
688PNG_EXTERN void png_reset_crc PNGARG((png_structp png_ptr));
689
690/* Write the "data" buffer to whatever output you are using */
691PNG_EXTERN void png_write_data PNGARG((png_structp png_ptr,
692 png_const_bytep data, png_size_t length));
693
694/* Read and check the PNG file signature */
695PNG_EXTERN void png_read_sig PNGARG((png_structp png_ptr, png_infop info_ptr));
696
697/* Read the chunk header (length + type name) */
698PNG_EXTERN png_uint_32 png_read_chunk_header PNGARG((png_structp png_ptr));
699
700/* Read data from whatever input you are using into the "data" buffer */
701PNG_EXTERN void png_read_data PNGARG((png_structp png_ptr, png_bytep data,
702 png_size_t length));
703
704/* Read bytes into buf, and update png_ptr->crc */
705PNG_EXTERN void png_crc_read PNGARG((png_structp png_ptr, png_bytep buf,
706 png_size_t length));
707
708/* Decompress data in a chunk that uses compression */
709#if defined(PNG_READ_COMPRESSED_TEXT_SUPPORTED)
710PNG_EXTERN void png_decompress_chunk PNGARG((png_structp png_ptr,
711 int comp_type, png_size_t chunklength, png_size_t prefix_length,
712 png_size_t *data_length));
713#endif
714
715/* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */
716PNG_EXTERN int png_crc_finish PNGARG((png_structp png_ptr, png_uint_32 skip));
717
718/* Read the CRC from the file and compare it to the libpng calculated CRC */
719PNG_EXTERN int png_crc_error PNGARG((png_structp png_ptr));
720
721/* Calculate the CRC over a section of data. Note that we are only
722 * passing a maximum of 64K on systems that have this as a memory limit,
723 * since this is the maximum buffer size we can specify.
724 */
725PNG_EXTERN void png_calculate_crc PNGARG((png_structp png_ptr,
726 png_const_bytep ptr, png_size_t length));
727
728#ifdef PNG_WRITE_FLUSH_SUPPORTED
729PNG_EXTERN void png_flush PNGARG((png_structp png_ptr));
730#endif
731
732/* Write various chunks */
733
734/* Write the IHDR chunk, and update the png_struct with the necessary
735 * information.
736 */
737PNG_EXTERN void png_write_IHDR PNGARG((png_structp png_ptr, png_uint_32 width,
738 png_uint_32 height,
739 int bit_depth, int color_type, int compression_method, int filter_method,
740 int interlace_method));
741
742PNG_EXTERN void png_write_PLTE PNGARG((png_structp png_ptr,
743 png_const_colorp palette, png_uint_32 num_pal));
744
745PNG_EXTERN void png_write_IDAT PNGARG((png_structp png_ptr, png_bytep data,
746 png_size_t length));
747
748PNG_EXTERN void png_write_IEND PNGARG((png_structp png_ptr));
749
750#ifdef PNG_WRITE_gAMA_SUPPORTED
751# ifdef PNG_FLOATING_POINT_SUPPORTED
752PNG_EXTERN void png_write_gAMA PNGARG((png_structp png_ptr, double file_gamma));
753# endif
754# ifdef PNG_FIXED_POINT_SUPPORTED
755PNG_EXTERN void png_write_gAMA_fixed PNGARG((png_structp png_ptr,
756 png_fixed_point file_gamma));
757# endif
758#endif
759
760#ifdef PNG_WRITE_sBIT_SUPPORTED
761PNG_EXTERN void png_write_sBIT PNGARG((png_structp png_ptr,
762 png_const_color_8p sbit, int color_type));
763#endif
764
765#ifdef PNG_WRITE_cHRM_SUPPORTED
766# ifdef PNG_FLOATING_POINT_SUPPORTED
767PNG_EXTERN void png_write_cHRM PNGARG((png_structp png_ptr,
768 double white_x, double white_y,
769 double red_x, double red_y, double green_x, double green_y,
770 double blue_x, double blue_y));
771# endif
772PNG_EXTERN void png_write_cHRM_fixed PNGARG((png_structp png_ptr,
773 png_fixed_point int_white_x, png_fixed_point int_white_y,
774 png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
775 int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
776 png_fixed_point int_blue_y));
777#endif
778
779#ifdef PNG_WRITE_sRGB_SUPPORTED
780PNG_EXTERN void png_write_sRGB PNGARG((png_structp png_ptr,
781 int intent));
782#endif
783
784#ifdef PNG_WRITE_iCCP_SUPPORTED
785PNG_EXTERN void png_write_iCCP PNGARG((png_structp png_ptr,
786 png_const_charp name, int compression_type,
787 png_const_charp profile, int proflen));
788 /* Note to maintainer: profile should be png_bytep */
789#endif
790
791#ifdef PNG_WRITE_sPLT_SUPPORTED
792PNG_EXTERN void png_write_sPLT PNGARG((png_structp png_ptr,
793 png_const_sPLT_tp palette));
794#endif
795
796#ifdef PNG_WRITE_tRNS_SUPPORTED
797PNG_EXTERN void png_write_tRNS PNGARG((png_structp png_ptr,
798 png_const_bytep trans, png_const_color_16p values, int number,
799 int color_type));
800#endif
801
802#ifdef PNG_WRITE_bKGD_SUPPORTED
803PNG_EXTERN void png_write_bKGD PNGARG((png_structp png_ptr,
804 png_const_color_16p values, int color_type));
805#endif
806
807#ifdef PNG_WRITE_hIST_SUPPORTED
808PNG_EXTERN void png_write_hIST PNGARG((png_structp png_ptr,
809 png_const_uint_16p hist, int num_hist));
810#endif
811
812/* Chunks that have keywords */
813#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \
814 defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
815PNG_EXTERN png_size_t png_check_keyword PNGARG((png_structp png_ptr,
816 png_const_charp key, png_charpp new_key));
817#endif
818
819#ifdef PNG_WRITE_tEXt_SUPPORTED
820PNG_EXTERN void png_write_tEXt PNGARG((png_structp png_ptr, png_const_charp key,
821 png_const_charp text, png_size_t text_len));
822#endif
823
824#ifdef PNG_WRITE_zTXt_SUPPORTED
825PNG_EXTERN void png_write_zTXt PNGARG((png_structp png_ptr, png_const_charp key,
826 png_const_charp text, png_size_t text_len, int compression));
827#endif
828
829#ifdef PNG_WRITE_iTXt_SUPPORTED
830PNG_EXTERN void png_write_iTXt PNGARG((png_structp png_ptr,
831 int compression, png_const_charp key, png_const_charp lang,
832 png_const_charp lang_key, png_const_charp text));
833#endif
834
835#ifdef PNG_TEXT_SUPPORTED /* Added at version 1.0.14 and 1.2.4 */
836PNG_EXTERN int png_set_text_2 PNGARG((png_structp png_ptr,
837 png_infop info_ptr, png_const_textp text_ptr, int num_text));
838#endif
839
840#ifdef PNG_WRITE_oFFs_SUPPORTED
841PNG_EXTERN void png_write_oFFs PNGARG((png_structp png_ptr,
842 png_int_32 x_offset, png_int_32 y_offset, int unit_type));
843#endif
844
845#ifdef PNG_WRITE_pCAL_SUPPORTED
846PNG_EXTERN void png_write_pCAL PNGARG((png_structp png_ptr, png_charp purpose,
847 png_int_32 X0, png_int_32 X1, int type, int nparams,
848 png_const_charp units, png_charpp params));
849#endif
850
851#ifdef PNG_WRITE_pHYs_SUPPORTED
852PNG_EXTERN void png_write_pHYs PNGARG((png_structp png_ptr,
853 png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit,
854 int unit_type));
855#endif
856
857#ifdef PNG_WRITE_tIME_SUPPORTED
858PNG_EXTERN void png_write_tIME PNGARG((png_structp png_ptr,
859 png_const_timep mod_time));
860#endif
861
862#ifdef PNG_WRITE_sCAL_SUPPORTED
863PNG_EXTERN void png_write_sCAL_s PNGARG((png_structp png_ptr,
864 int unit, png_const_charp width, png_const_charp height));
865#endif
866
867/* Called when finished processing a row of data */
868PNG_EXTERN void png_write_finish_row PNGARG((png_structp png_ptr));
869
870/* Internal use only. Called before first row of data */
871PNG_EXTERN void png_write_start_row PNGARG((png_structp png_ptr));
872
873/* Combine a row of data, dealing with alpha, etc. if requested. 'row' is an
874 * array of png_ptr->width pixels. If the image is not interlaced or this
875 * is the final pass this just does a png_memcpy, otherwise the "display" flag
876 * is used to determine whether to copy pixels that are not in the current pass.
877 *
878 * Because 'png_do_read_interlace' (below) replicates pixels this allows this
879 * function to achieve the documented 'blocky' appearance during interlaced read
880 * if display is 1 and the 'sparkle' appearance, where existing pixels in 'row'
881 * are not changed if they are not in the current pass, when display is 0.
882 *
883 * 'display' must be 0 or 1, otherwise the memcpy will be done regardless.
884 *
885 * The API always reads from the png_struct row buffer and always assumes that
886 * it is full width (png_do_read_interlace has already been called.)
887 *
888 * This function is only ever used to write to row buffers provided by the
889 * caller of the relevant libpng API and the row must have already been
890 * transformed by the read transformations.
891 *
892 * The PNG_USE_COMPILE_TIME_MASKS option causes generation of pre-computed
893 * bitmasks for use within the code, otherwise runtime generated masks are used.
894 * The default is compile time masks.
895 */
896#ifndef PNG_USE_COMPILE_TIME_MASKS
897# define PNG_USE_COMPILE_TIME_MASKS 1
898#endif
899PNG_EXTERN void png_combine_row PNGARG((png_structp png_ptr, png_bytep row,
900 int display));
901
902#ifdef PNG_READ_INTERLACING_SUPPORTED
903/* Expand an interlaced row: the 'row_info' describes the pass data that has
904 * been read in and must correspond to the pixels in 'row', the pixels are
905 * expanded (moved apart) in 'row' to match the final layout, when doing this
906 * the pixels are *replicated* to the intervening space. This is essential for
907 * the correct operation of png_combine_row, above.
908 */
909PNG_EXTERN void png_do_read_interlace PNGARG((png_row_infop row_info,
910 png_bytep row, int pass, png_uint_32 transformations));
911#endif
912
913/* GRR TO DO (2.0 or whenever): simplify other internal calling interfaces */
914
915#ifdef PNG_WRITE_INTERLACING_SUPPORTED
916/* Grab pixels out of a row for an interlaced pass */
917PNG_EXTERN void png_do_write_interlace PNGARG((png_row_infop row_info,
918 png_bytep row, int pass));
919#endif
920
921/* Unfilter a row: check the filter value before calling this, there is no point
922 * calling it for PNG_FILTER_VALUE_NONE.
923 */
924PNG_EXTERN void png_read_filter_row PNGARG((png_row_infop row_info,
925 png_bytep row, png_const_bytep prev_row, int filter));
926
927/* Choose the best filter to use and filter the row data */
928PNG_EXTERN void png_write_find_filter PNGARG((png_structp png_ptr,
929 png_row_infop row_info));
930
931/* Finish a row while reading, dealing with interlacing passes, etc. */
932PNG_EXTERN void png_read_finish_row PNGARG((png_structp png_ptr));
933
934/* Initialize the row buffers, etc. */
935PNG_EXTERN void png_read_start_row PNGARG((png_structp png_ptr));
936
937#ifdef PNG_READ_TRANSFORMS_SUPPORTED
938/* Optional call to update the users info structure */
939PNG_EXTERN void png_read_transform_info PNGARG((png_structp png_ptr,
940 png_infop info_ptr));
941#endif
942
943/* These are the functions that do the transformations */
944#ifdef PNG_READ_FILLER_SUPPORTED
945PNG_EXTERN void png_do_read_filler PNGARG((png_row_infop row_info,
946 png_bytep row, png_uint_32 filler, png_uint_32 flags));
947#endif
948
949#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
950PNG_EXTERN void png_do_read_swap_alpha PNGARG((png_row_infop row_info,
951 png_bytep row));
952#endif
953
954#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
955PNG_EXTERN void png_do_write_swap_alpha PNGARG((png_row_infop row_info,
956 png_bytep row));
957#endif
958
959#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
960PNG_EXTERN void png_do_read_invert_alpha PNGARG((png_row_infop row_info,
961 png_bytep row));
962#endif
963
964#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
965PNG_EXTERN void png_do_write_invert_alpha PNGARG((png_row_infop row_info,
966 png_bytep row));
967#endif
968
969#if defined(PNG_WRITE_FILLER_SUPPORTED) || \
970 defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
971PNG_EXTERN void png_do_strip_channel PNGARG((png_row_infop row_info,
972 png_bytep row, int at_start));
973#endif
974
975#ifdef PNG_16BIT_SUPPORTED
976#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
977PNG_EXTERN void png_do_swap PNGARG((png_row_infop row_info,
978 png_bytep row));
979#endif
980#endif
981
982#if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
983 defined(PNG_WRITE_PACKSWAP_SUPPORTED)
984PNG_EXTERN void png_do_packswap PNGARG((png_row_infop row_info,
985 png_bytep row));
986#endif
987
988#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
989PNG_EXTERN int png_do_rgb_to_gray PNGARG((png_structp png_ptr,
990 png_row_infop row_info, png_bytep row));
991#endif
992
993#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
994PNG_EXTERN void png_do_gray_to_rgb PNGARG((png_row_infop row_info,
995 png_bytep row));
996#endif
997
998#ifdef PNG_READ_PACK_SUPPORTED
999PNG_EXTERN void png_do_unpack PNGARG((png_row_infop row_info,
1000 png_bytep row));
1001#endif
1002
1003#ifdef PNG_READ_SHIFT_SUPPORTED
1004PNG_EXTERN void png_do_unshift PNGARG((png_row_infop row_info,
1005 png_bytep row, png_const_color_8p sig_bits));
1006#endif
1007
1008#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
1009PNG_EXTERN void png_do_invert PNGARG((png_row_infop row_info,
1010 png_bytep row));
1011#endif
1012
1013#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
1014PNG_EXTERN void png_do_scale_16_to_8 PNGARG((png_row_infop row_info,
1015 png_bytep row));
1016#endif
1017
1018#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
1019PNG_EXTERN void png_do_chop PNGARG((png_row_infop row_info,
1020 png_bytep row));
1021#endif
1022
1023#ifdef PNG_READ_QUANTIZE_SUPPORTED
1024PNG_EXTERN void png_do_quantize PNGARG((png_row_infop row_info,
1025 png_bytep row, png_const_bytep palette_lookup,
1026 png_const_bytep quantize_lookup));
1027
1028# ifdef PNG_CORRECT_PALETTE_SUPPORTED
1029PNG_EXTERN void png_correct_palette PNGARG((png_structp png_ptr,
1030 png_colorp palette, int num_palette));
1031# endif
1032#endif
1033
1034#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
1035PNG_EXTERN void png_do_bgr PNGARG((png_row_infop row_info,
1036 png_bytep row));
1037#endif
1038
1039#ifdef PNG_WRITE_PACK_SUPPORTED
1040PNG_EXTERN void png_do_pack PNGARG((png_row_infop row_info,
1041 png_bytep row, png_uint_32 bit_depth));
1042#endif
1043
1044#ifdef PNG_WRITE_SHIFT_SUPPORTED
1045PNG_EXTERN void png_do_shift PNGARG((png_row_infop row_info,
1046 png_bytep row, png_const_color_8p bit_depth));
1047#endif
1048
1049#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
1050 defined(PNG_READ_ALPHA_MODE_SUPPORTED)
1051PNG_EXTERN void png_do_compose PNGARG((png_row_infop row_info,
1052 png_bytep row, png_structp png_ptr));
1053#endif
1054
1055#ifdef PNG_READ_GAMMA_SUPPORTED
1056PNG_EXTERN void png_do_gamma PNGARG((png_row_infop row_info,
1057 png_bytep row, png_structp png_ptr));
1058#endif
1059
1060#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
1061PNG_EXTERN void png_do_encode_alpha PNGARG((png_row_infop row_info,
1062 png_bytep row, png_structp png_ptr));
1063#endif
1064
1065#ifdef PNG_READ_EXPAND_SUPPORTED
1066PNG_EXTERN void png_do_expand_palette PNGARG((png_row_infop row_info,
1067 png_bytep row, png_const_colorp palette, png_const_bytep trans,
1068 int num_trans));
1069PNG_EXTERN void png_do_expand PNGARG((png_row_infop row_info,
1070 png_bytep row, png_const_color_16p trans_color));
1071#endif
1072
1073#ifdef PNG_READ_EXPAND_16_SUPPORTED
1074PNG_EXTERN void png_do_expand_16 PNGARG((png_row_infop row_info,
1075 png_bytep row));
1076#endif
1077
1078/* The following decodes the appropriate chunks, and does error correction,
1079 * then calls the appropriate callback for the chunk if it is valid.
1080 */
1081
1082/* Decode the IHDR chunk */
1083PNG_EXTERN void png_handle_IHDR PNGARG((png_structp png_ptr, png_infop info_ptr,
1084 png_uint_32 length));
1085PNG_EXTERN void png_handle_PLTE PNGARG((png_structp png_ptr, png_infop info_ptr,
1086 png_uint_32 length));
1087PNG_EXTERN void png_handle_IEND PNGARG((png_structp png_ptr, png_infop info_ptr,
1088 png_uint_32 length));
1089
1090#ifdef PNG_READ_bKGD_SUPPORTED
1091PNG_EXTERN void png_handle_bKGD PNGARG((png_structp png_ptr, png_infop info_ptr,
1092 png_uint_32 length));
1093#endif
1094
1095#ifdef PNG_READ_cHRM_SUPPORTED
1096PNG_EXTERN void png_handle_cHRM PNGARG((png_structp png_ptr, png_infop info_ptr,
1097 png_uint_32 length));
1098#endif
1099
1100#ifdef PNG_READ_gAMA_SUPPORTED
1101PNG_EXTERN void png_handle_gAMA PNGARG((png_structp png_ptr, png_infop info_ptr,
1102 png_uint_32 length));
1103#endif
1104
1105#ifdef PNG_READ_hIST_SUPPORTED
1106PNG_EXTERN void png_handle_hIST PNGARG((png_structp png_ptr, png_infop info_ptr,
1107 png_uint_32 length));
1108#endif
1109
1110#ifdef PNG_READ_iCCP_SUPPORTED
1111PNG_EXTERN void png_handle_iCCP PNGARG((png_structp png_ptr, png_infop info_ptr,
1112 png_uint_32 length));
1113#endif /* PNG_READ_iCCP_SUPPORTED */
1114
1115#ifdef PNG_READ_iTXt_SUPPORTED
1116PNG_EXTERN void png_handle_iTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
1117 png_uint_32 length));
1118#endif
1119
1120#ifdef PNG_READ_oFFs_SUPPORTED
1121PNG_EXTERN void png_handle_oFFs PNGARG((png_structp png_ptr, png_infop info_ptr,
1122 png_uint_32 length));
1123#endif
1124
1125#ifdef PNG_READ_pCAL_SUPPORTED
1126PNG_EXTERN void png_handle_pCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
1127 png_uint_32 length));
1128#endif
1129
1130#ifdef PNG_READ_pHYs_SUPPORTED
1131PNG_EXTERN void png_handle_pHYs PNGARG((png_structp png_ptr, png_infop info_ptr,
1132 png_uint_32 length));
1133#endif
1134
1135#ifdef PNG_READ_sBIT_SUPPORTED
1136PNG_EXTERN void png_handle_sBIT PNGARG((png_structp png_ptr, png_infop info_ptr,
1137 png_uint_32 length));
1138#endif
1139
1140#ifdef PNG_READ_sCAL_SUPPORTED
1141PNG_EXTERN void png_handle_sCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
1142 png_uint_32 length));
1143#endif
1144
1145#ifdef PNG_READ_sPLT_SUPPORTED
1146PNG_EXTERN void png_handle_sPLT PNGARG((png_structp png_ptr, png_infop info_ptr,
1147 png_uint_32 length));
1148#endif /* PNG_READ_sPLT_SUPPORTED */
1149
1150#ifdef PNG_READ_sRGB_SUPPORTED
1151PNG_EXTERN void png_handle_sRGB PNGARG((png_structp png_ptr, png_infop info_ptr,
1152 png_uint_32 length));
1153#endif
1154
1155#ifdef PNG_READ_tEXt_SUPPORTED
1156PNG_EXTERN void png_handle_tEXt PNGARG((png_structp png_ptr, png_infop info_ptr,
1157 png_uint_32 length));
1158#endif
1159
1160#ifdef PNG_READ_tIME_SUPPORTED
1161PNG_EXTERN void png_handle_tIME PNGARG((png_structp png_ptr, png_infop info_ptr,
1162 png_uint_32 length));
1163#endif
1164
1165#ifdef PNG_READ_tRNS_SUPPORTED
1166PNG_EXTERN void png_handle_tRNS PNGARG((png_structp png_ptr, png_infop info_ptr,
1167 png_uint_32 length));
1168#endif
1169
1170#ifdef PNG_READ_zTXt_SUPPORTED
1171PNG_EXTERN void png_handle_zTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
1172 png_uint_32 length));
1173#endif
1174
1175#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
1176PNG_EXTERN void png_handle_unknown PNGARG((png_structp png_ptr,
1177 png_infop info_ptr, png_uint_32 length));
1178#endif
1179
1180PNG_EXTERN void png_check_chunk_name PNGARG((png_structp png_ptr,
1181 png_uint_32 chunk_name));
1182
1183#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
1184/* Exactly as png_handle_as_unknown() except that the argument is a 32-bit chunk
1185 * name, not a string.
1186 */
1187PNG_EXTERN int png_chunk_unknown_handling PNGARG((png_structp png_ptr,
1188 png_uint_32 chunk_name));
1189#endif
1190
1191/* Handle the transformations for reading and writing */
1192#ifdef PNG_READ_TRANSFORMS_SUPPORTED
1193PNG_EXTERN void png_do_read_transformations PNGARG((png_structp png_ptr,
1194 png_row_infop row_info));
1195#endif
1196#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
1197PNG_EXTERN void png_do_write_transformations PNGARG((png_structp png_ptr,
1198 png_row_infop row_info));
1199#endif
1200
1201#ifdef PNG_READ_TRANSFORMS_SUPPORTED
1202PNG_EXTERN void png_init_read_transformations PNGARG((png_structp png_ptr));
1203#endif
1204
1205#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1206PNG_EXTERN void png_push_read_chunk PNGARG((png_structp png_ptr,
1207 png_infop info_ptr));
1208PNG_EXTERN void png_push_read_sig PNGARG((png_structp png_ptr,
1209 png_infop info_ptr));
1210PNG_EXTERN void png_push_check_crc PNGARG((png_structp png_ptr));
1211PNG_EXTERN void png_push_crc_skip PNGARG((png_structp png_ptr,
1212 png_uint_32 length));
1213PNG_EXTERN void png_push_crc_finish PNGARG((png_structp png_ptr));
1214PNG_EXTERN void png_push_save_buffer PNGARG((png_structp png_ptr));
1215PNG_EXTERN void png_push_restore_buffer PNGARG((png_structp png_ptr,
1216 png_bytep buffer, png_size_t buffer_length));
1217PNG_EXTERN void png_push_read_IDAT PNGARG((png_structp png_ptr));
1218PNG_EXTERN void png_process_IDAT_data PNGARG((png_structp png_ptr,
1219 png_bytep buffer, png_size_t buffer_length));
1220PNG_EXTERN void png_push_process_row PNGARG((png_structp png_ptr));
1221PNG_EXTERN void png_push_handle_unknown PNGARG((png_structp png_ptr,
1222 png_infop info_ptr, png_uint_32 length));
1223PNG_EXTERN void png_push_have_info PNGARG((png_structp png_ptr,
1224 png_infop info_ptr));
1225PNG_EXTERN void png_push_have_end PNGARG((png_structp png_ptr,
1226 png_infop info_ptr));
1227PNG_EXTERN void png_push_have_row PNGARG((png_structp png_ptr, png_bytep row));
1228PNG_EXTERN void png_push_read_end PNGARG((png_structp png_ptr,
1229 png_infop info_ptr));
1230PNG_EXTERN void png_process_some_data PNGARG((png_structp png_ptr,
1231 png_infop info_ptr));
1232PNG_EXTERN void png_read_push_finish_row PNGARG((png_structp png_ptr));
1233# ifdef PNG_READ_tEXt_SUPPORTED
1234PNG_EXTERN void png_push_handle_tEXt PNGARG((png_structp png_ptr,
1235 png_infop info_ptr, png_uint_32 length));
1236PNG_EXTERN void png_push_read_tEXt PNGARG((png_structp png_ptr,
1237 png_infop info_ptr));
1238# endif
1239# ifdef PNG_READ_zTXt_SUPPORTED
1240PNG_EXTERN void png_push_handle_zTXt PNGARG((png_structp png_ptr,
1241 png_infop info_ptr, png_uint_32 length));
1242PNG_EXTERN void png_push_read_zTXt PNGARG((png_structp png_ptr,
1243 png_infop info_ptr));
1244# endif
1245# ifdef PNG_READ_iTXt_SUPPORTED
1246PNG_EXTERN void png_push_handle_iTXt PNGARG((png_structp png_ptr,
1247 png_infop info_ptr, png_uint_32 length));
1248PNG_EXTERN void png_push_read_iTXt PNGARG((png_structp png_ptr,
1249 png_infop info_ptr));
1250# endif
1251
1252#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
1253
1254#ifdef PNG_MNG_FEATURES_SUPPORTED
1255PNG_EXTERN void png_do_read_intrapixel PNGARG((png_row_infop row_info,
1256 png_bytep row));
1257PNG_EXTERN void png_do_write_intrapixel PNGARG((png_row_infop row_info,
1258 png_bytep row));
1259#endif
1260
1261/* Added at libpng version 1.4.0 */
1262#ifdef PNG_CHECK_cHRM_SUPPORTED
1263PNG_EXTERN int png_check_cHRM_fixed PNGARG((png_structp png_ptr,
1264 png_fixed_point int_white_x, png_fixed_point int_white_y,
1265 png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
1266 int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
1267 png_fixed_point int_blue_y));
1268#endif
1269
1270#ifdef PNG_CHECK_cHRM_SUPPORTED
1271/* Added at libpng version 1.2.34 and 1.4.0 */
1272/* Currently only used by png_check_cHRM_fixed */
1273PNG_EXTERN void png_64bit_product PNGARG((long v1, long v2,
1274 unsigned long *hi_product, unsigned long *lo_product));
1275#endif
1276
1277#ifdef PNG_cHRM_SUPPORTED
1278/* Added at libpng version 1.5.5 */
1279typedef struct png_xy
1280{
1281 png_fixed_point redx, redy;
1282 png_fixed_point greenx, greeny;
1283 png_fixed_point bluex, bluey;
1284 png_fixed_point whitex, whitey;
1285} png_xy;
1286
1287typedef struct png_XYZ
1288{
1289 png_fixed_point redX, redY, redZ;
1290 png_fixed_point greenX, greenY, greenZ;
1291 png_fixed_point blueX, blueY, blueZ;
1292} png_XYZ;
1293
1294/* The conversion APIs return 0 on success, non-zero on a parameter error. They
1295 * allow conversion between the above representations of a color encoding. When
1296 * converting from XYZ end points to chromaticities the absolute magnitude of
1297 * the end points is lost, when converting back the sum of the Y values of the
1298 * three end points will be 1.0
1299 */
1300PNG_EXTERN int png_xy_from_XYZ PNGARG((png_xy *xy, png_XYZ XYZ));
1301PNG_EXTERN int png_XYZ_from_xy PNGARG((png_XYZ *XYZ, png_xy xy));
1302PNG_EXTERN int png_XYZ_from_xy_checked PNGARG((png_structp png_ptr,
1303 png_XYZ *XYZ, png_xy xy));
1304#endif
1305
1306/* Added at libpng version 1.4.0 */
1307PNG_EXTERN void png_check_IHDR PNGARG((png_structp png_ptr,
1308 png_uint_32 width, png_uint_32 height, int bit_depth,
1309 int color_type, int interlace_type, int compression_type,
1310 int filter_type));
1311
1312/* Free all memory used by the read (old method - NOT DLL EXPORTED) */
1313PNG_EXTERN void png_read_destroy PNGARG((png_structp png_ptr,
1314 png_infop info_ptr, png_infop end_info_ptr));
1315
1316/* Free any memory used in png_ptr struct (old method - NOT DLL EXPORTED) */
1317PNG_EXTERN void png_write_destroy PNGARG((png_structp png_ptr));
1318
1319#ifdef USE_FAR_KEYWORD /* memory model conversion function */
1320PNG_EXTERN void *png_far_to_near PNGARG((png_structp png_ptr, png_voidp ptr,
1321 int check));
1322#endif /* USE_FAR_KEYWORD */
1323
1324#if defined(PNG_FLOATING_POINT_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED)
1325PNG_EXTERN PNG_FUNCTION(void, png_fixed_error, (png_structp png_ptr,
1326 png_const_charp name),PNG_NORETURN);
1327#endif
1328
1329/* Puts 'string' into 'buffer' at buffer[pos], taking care never to overwrite
1330 * the end. Always leaves the buffer nul terminated. Never errors out (and
1331 * there is no error code.)
1332 */
1333PNG_EXTERN size_t png_safecat(png_charp buffer, size_t bufsize, size_t pos,
1334 png_const_charp string);
1335
1336/* Various internal functions to handle formatted warning messages, currently
1337 * only implemented for warnings.
1338 */
1339#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_SUPPORTED)
1340/* Utility to dump an unsigned value into a buffer, given a start pointer and
1341 * and end pointer (which should point just *beyond* the end of the buffer!)
1342 * Returns the pointer to the start of the formatted string. This utility only
1343 * does unsigned values.
1344 */
1345PNG_EXTERN png_charp png_format_number(png_const_charp start, png_charp end,
1346 int format, png_alloc_size_t number);
1347
1348/* Convenience macro that takes an array: */
1349#define PNG_FORMAT_NUMBER(buffer,format,number) \
1350 png_format_number(buffer, buffer + (sizeof buffer), format, number)
1351
1352/* Suggested size for a number buffer (enough for 64 bits and a sign!) */
1353#define PNG_NUMBER_BUFFER_SIZE 24
1354
1355/* These are the integer formats currently supported, the name is formed from
1356 * the standard printf(3) format string.
1357 */
1358#define PNG_NUMBER_FORMAT_u 1 /* chose unsigned API! */
1359#define PNG_NUMBER_FORMAT_02u 2
1360#define PNG_NUMBER_FORMAT_d 1 /* chose signed API! */
1361#define PNG_NUMBER_FORMAT_02d 2
1362#define PNG_NUMBER_FORMAT_x 3
1363#define PNG_NUMBER_FORMAT_02x 4
1364#define PNG_NUMBER_FORMAT_fixed 5 /* choose the signed API */
1365#endif
1366
1367#ifdef PNG_WARNINGS_SUPPORTED
1368/* New defines and members adding in libpng-1.5.4 */
1369# define PNG_WARNING_PARAMETER_SIZE 32
1370# define PNG_WARNING_PARAMETER_COUNT 8
1371
1372/* An l-value of this type has to be passed to the APIs below to cache the
1373 * values of the parameters to a formatted warning message.
1374 */
1375typedef char png_warning_parameters[PNG_WARNING_PARAMETER_COUNT][
1376 PNG_WARNING_PARAMETER_SIZE];
1377
1378PNG_EXTERN void png_warning_parameter(png_warning_parameters p, int number,
1379 png_const_charp string);
1380 /* Parameters are limited in size to PNG_WARNING_PARAMETER_SIZE characters,
1381 * including the trailing '\0'.
1382 */
1383PNG_EXTERN void png_warning_parameter_unsigned(png_warning_parameters p,
1384 int number, int format, png_alloc_size_t value);
1385 /* Use png_alloc_size_t because it is an unsigned type as big as any we
1386 * need to output. Use the following for a signed value.
1387 */
1388PNG_EXTERN void png_warning_parameter_signed(png_warning_parameters p,
1389 int number, int format, png_int_32 value);
1390
1391PNG_EXTERN void png_formatted_warning(png_structp png_ptr,
1392 png_warning_parameters p, png_const_charp message);
1393 /* 'message' follows the X/Open approach of using @1, @2 to insert
1394 * parameters previously supplied using the above functions. Errors in
1395 * specifying the paramters will simple result in garbage substitutions.
1396 */
1397#endif
1398
1399/* ASCII to FP interfaces, currently only implemented if sCAL
1400 * support is required.
1401 */
1402#if defined(PNG_READ_sCAL_SUPPORTED)
1403/* MAX_DIGITS is actually the maximum number of characters in an sCAL
1404 * width or height, derived from the precision (number of significant
1405 * digits - a build time settable option) and assumpitions about the
1406 * maximum ridiculous exponent.
1407 */
1408#define PNG_sCAL_MAX_DIGITS (PNG_sCAL_PRECISION+1/*.*/+1/*E*/+10/*exponent*/)
1409
1410#ifdef PNG_FLOATING_POINT_SUPPORTED
1411PNG_EXTERN void png_ascii_from_fp PNGARG((png_structp png_ptr, png_charp ascii,
1412 png_size_t size, double fp, unsigned int precision));
1413#endif /* FLOATING_POINT */
1414
1415#ifdef PNG_FIXED_POINT_SUPPORTED
1416PNG_EXTERN void png_ascii_from_fixed PNGARG((png_structp png_ptr,
1417 png_charp ascii, png_size_t size, png_fixed_point fp));
1418#endif /* FIXED_POINT */
1419#endif /* READ_sCAL */
1420
1421#if defined(PNG_sCAL_SUPPORTED) || defined(PNG_pCAL_SUPPORTED)
1422/* An internal API to validate the format of a floating point number.
1423 * The result is the index of the next character. If the number is
1424 * not valid it will be the index of a character in the supposed number.
1425 *
1426 * The format of a number is defined in the PNG extensions specification
1427 * and this API is strictly conformant to that spec, not anyone elses!
1428 *
1429 * The format as a regular expression is:
1430 *
1431 * [+-]?[0-9]+.?([Ee][+-]?[0-9]+)?
1432 *
1433 * or:
1434 *
1435 * [+-]?.[0-9]+(.[0-9]+)?([Ee][+-]?[0-9]+)?
1436 *
1437 * The complexity is that either integer or fraction must be present and the
1438 * fraction is permitted to have no digits only if the integer is present.
1439 *
1440 * NOTE: The dangling E problem.
1441 * There is a PNG valid floating point number in the following:
1442 *
1443 * PNG floating point numb1.ers are not greedy.
1444 *
1445 * Working this out requires *TWO* character lookahead (because of the
1446 * sign), the parser does not do this - it will fail at the 'r' - this
1447 * doesn't matter for PNG sCAL chunk values, but it requires more care
1448 * if the value were ever to be embedded in something more complex. Use
1449 * ANSI-C strtod if you need the lookahead.
1450 */
1451/* State table for the parser. */
1452#define PNG_FP_INTEGER 0 /* before or in integer */
1453#define PNG_FP_FRACTION 1 /* before or in fraction */
1454#define PNG_FP_EXPONENT 2 /* before or in exponent */
1455#define PNG_FP_STATE 3 /* mask for the above */
1456#define PNG_FP_SAW_SIGN 4 /* Saw +/- in current state */
1457#define PNG_FP_SAW_DIGIT 8 /* Saw a digit in current state */
1458#define PNG_FP_SAW_DOT 16 /* Saw a dot in current state */
1459#define PNG_FP_SAW_E 32 /* Saw an E (or e) in current state */
1460#define PNG_FP_SAW_ANY 60 /* Saw any of the above 4 */
1461
1462/* These three values don't affect the parser. They are set but not used.
1463 */
1464#define PNG_FP_WAS_VALID 64 /* Preceding substring is a valid fp number */
1465#define PNG_FP_NEGATIVE 128 /* A negative number, including "-0" */
1466#define PNG_FP_NONZERO 256 /* A non-zero value */
1467#define PNG_FP_STICKY 448 /* The above three flags */
1468
1469/* This is available for the caller to store in 'state' if required. Do not
1470 * call the parser after setting it (the parser sometimes clears it.)
1471 */
1472#define PNG_FP_INVALID 512 /* Available for callers as a distinct value */
1473
1474/* Result codes for the parser (boolean - true meants ok, false means
1475 * not ok yet.)
1476 */
1477#define PNG_FP_MAYBE 0 /* The number may be valid in the future */
1478#define PNG_FP_OK 1 /* The number is valid */
1479
1480/* Tests on the sticky non-zero and negative flags. To pass these checks
1481 * the state must also indicate that the whole number is valid - this is
1482 * achieved by testing PNG_FP_SAW_DIGIT (see the implementation for why this
1483 * is equivalent to PNG_FP_OK above.)
1484 */
1485#define PNG_FP_NZ_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NEGATIVE | PNG_FP_NONZERO)
1486 /* NZ_MASK: the string is valid and a non-zero negative value */
1487#define PNG_FP_Z_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NONZERO)
1488 /* Z MASK: the string is valid and a non-zero value. */
1489 /* PNG_FP_SAW_DIGIT: the string is valid. */
1490#define PNG_FP_IS_ZERO(state) (((state) & PNG_FP_Z_MASK) == PNG_FP_SAW_DIGIT)
1491#define PNG_FP_IS_POSITIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_Z_MASK)
1492#define PNG_FP_IS_NEGATIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_NZ_MASK)
1493
1494/* The actual parser. This can be called repeatedly, it updates
1495 * the index into the string and the state variable (which must
1496 * be initialzed to 0). It returns a result code, as above. There
1497 * is no point calling the parser any more if it fails to advance to
1498 * the end of the string - it is stuck on an invalid character (or
1499 * terminated by '\0').
1500 *
1501 * Note that the pointer will consume an E or even an E+ then leave
1502 * a 'maybe' state even though a preceding integer.fraction is valid.
1503 * The PNG_FP_WAS_VALID flag indicates that a preceding substring was
1504 * a valid number. It's possible to recover from this by calling
1505 * the parser again (from the start, with state 0) but with a string
1506 * that omits the last character (i.e. set the size to the index of
1507 * the problem character.) This has not been tested within libpng.
1508 */
1509PNG_EXTERN int png_check_fp_number PNGARG((png_const_charp string,
1510 png_size_t size, int *statep, png_size_tp whereami));
1511
1512/* This is the same but it checks a complete string and returns true
1513 * only if it just contains a floating point number. As of 1.5.4 this
1514 * function also returns the state at the end of parsing the number if
1515 * it was valid (otherwise it returns 0.) This can be used for testing
1516 * for negative or zero values using the sticky flag.
1517 */
1518PNG_EXTERN int png_check_fp_string PNGARG((png_const_charp string,
1519 png_size_t size));
1520#endif /* pCAL || sCAL */
1521
1522#if defined(PNG_READ_GAMMA_SUPPORTED) ||\
1523 defined(PNG_INCH_CONVERSIONS_SUPPORTED) || defined(PNG_READ_pHYs_SUPPORTED)
1524/* Added at libpng version 1.5.0 */
1525/* This is a utility to provide a*times/div (rounded) and indicate
1526 * if there is an overflow. The result is a boolean - false (0)
1527 * for overflow, true (1) if no overflow, in which case *res
1528 * holds the result.
1529 */
1530PNG_EXTERN int png_muldiv PNGARG((png_fixed_point_p res, png_fixed_point a,
1531 png_int_32 multiplied_by, png_int_32 divided_by));
1532#endif
1533
1534#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_INCH_CONVERSIONS_SUPPORTED)
1535/* Same deal, but issue a warning on overflow and return 0. */
1536PNG_EXTERN png_fixed_point png_muldiv_warn PNGARG((png_structp png_ptr,
1537 png_fixed_point a, png_int_32 multiplied_by, png_int_32 divided_by));
1538#endif
1539
1540#ifdef PNG_READ_GAMMA_SUPPORTED
1541/* Calculate a reciprocal - used for gamma values. This returns
1542 * 0 if the argument is 0 in order to maintain an undefined value,
1543 * there are no warnings.
1544 */
1545PNG_EXTERN png_fixed_point png_reciprocal PNGARG((png_fixed_point a));
1546
1547/* The same but gives a reciprocal of the product of two fixed point
1548 * values. Accuracy is suitable for gamma calculations but this is
1549 * not exact - use png_muldiv for that.
1550 */
1551PNG_EXTERN png_fixed_point png_reciprocal2 PNGARG((png_fixed_point a,
1552 png_fixed_point b));
1553#endif
1554
1555#ifdef PNG_READ_GAMMA_SUPPORTED
1556/* Internal fixed point gamma correction. These APIs are called as
1557 * required to convert single values - they don't need to be fast,
1558 * they are not used when processing image pixel values.
1559 *
1560 * While the input is an 'unsigned' value it must actually be the
1561 * correct bit value - 0..255 or 0..65535 as required.
1562 */
1563PNG_EXTERN png_uint_16 png_gamma_correct PNGARG((png_structp png_ptr,
1564 unsigned int value, png_fixed_point gamma_value));
1565PNG_EXTERN int png_gamma_significant PNGARG((png_fixed_point gamma_value));
1566PNG_EXTERN png_uint_16 png_gamma_16bit_correct PNGARG((unsigned int value,
1567 png_fixed_point gamma_value));
1568PNG_EXTERN png_byte png_gamma_8bit_correct PNGARG((unsigned int value,
1569 png_fixed_point gamma_value));
1570PNG_EXTERN void png_destroy_gamma_table(png_structp png_ptr);
1571PNG_EXTERN void png_build_gamma_table PNGARG((png_structp png_ptr,
1572 int bit_depth));
1573#endif
1574
1575/* Maintainer: Put new private prototypes here ^ and in libpngpf.3 */
1576
1577
1578#include "pngdebug.h"
1579
1580#ifdef __cplusplus
1581}
1582#endif
1583
1584#endif /* PNGPRIV_H */