source: rtems-graphics-toolkit/libpng-1.5.11/pngpriv.h @ 248419a

Last change on this file since 248419a was 248419a, checked in by Sebastian Huber <sebastian.huber@…>, on 07/12/12 at 07:28:02

Update libpng from 1.2.41 to 1.5.11
  • Property mode set to 100644
File size: 62.9 KB
Line 
1
2/* pngpriv.h - private declarations for use inside libpng
3 *
4 * For conditions of distribution and use, see copyright notice in png.h
5 * Copyright (c) 1998-2012 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.)
8 *
9 * Last changed in libpng 1.5.10 [March 29, 2012]
10 *
11 * This code is released under the libpng license.
12 * For conditions of distribution and use, see the disclaimer
13 * and license in png.h
14 */
15
16/* The symbols declared in this file (including the functions declared
17 * as PNG_EXTERN) are PRIVATE.  They are not part of the libpng public
18 * interface, and are not recommended for use by regular applications.
19 * Some of them may become public in the future; others may stay private,
20 * change in an incompatible way, or even disappear.
21 * Although the libpng users are not forbidden to include this header,
22 * they should be well aware of the issues that may arise from doing so.
23 */
24
25#ifndef PNGPRIV_H
26#define PNGPRIV_H
27
28/* Feature Test Macros.  The following are defined here to ensure that correctly
29 * implemented libraries reveal the APIs libpng needs to build and hide those
30 * that are not needed and potentially damaging to the compilation.
31 *
32 * Feature Test Macros must be defined before any system header is included (see
33 * POSIX 1003.1 2.8.2 "POSIX Symbols."
34 *
35 * These macros only have an effect if the operating system supports either
36 * POSIX 1003.1 or C99, or both.  On other operating systems (particularly
37 * Windows/Visual Studio) there is no effect; the OS specific tests below are
38 * still required (as of 2011-05-02.)
39 */
40#define _POSIX_SOURCE 1 /* Just the POSIX 1003.1 and C89 APIs */
41
42/* This is required for the definition of abort(), used as a last ditch
43 * error handler when all else fails.
44 */
45#include <stdlib.h>
46
47/* This is used to find 'offsetof', used below for alignment tests. */
48#include <stddef.h>
49
50#define PNGLIB_BUILD /*libpng is being built, not used*/
51
52#ifdef PNG_USER_CONFIG
53#  include "pngusr.h"
54   /* These should have been defined in pngusr.h */
55#  ifndef PNG_USER_PRIVATEBUILD
56#    define PNG_USER_PRIVATEBUILD "Custom libpng build"
57#  endif
58#  ifndef PNG_USER_DLLFNAME_POSTFIX
59#    define PNG_USER_DLLFNAME_POSTFIX "Cb"
60#  endif
61#endif
62
63/* Is this a build of a DLL where compilation of the object modules requires
64 * different preprocessor settings to those required for a simple library?  If
65 * so PNG_BUILD_DLL must be set.
66 *
67 * If libpng is used inside a DLL but that DLL does not export the libpng APIs
68 * PNG_BUILD_DLL must not be set.  To avoid the code below kicking in build a
69 * static library of libpng then link the DLL against that.
70 */
71#ifndef PNG_BUILD_DLL
72#  ifdef DLL_EXPORT
73      /* This is set by libtool when files are compiled for a DLL; libtool
74       * always compiles twice, even on systems where it isn't necessary.  Set
75       * PNG_BUILD_DLL in case it is necessary:
76       */
77#     define PNG_BUILD_DLL
78#  else
79#     ifdef _WINDLL
80         /* This is set by the Microsoft Visual Studio IDE in projects that
81          * build a DLL.  It can't easily be removed from those projects (it
82          * isn't visible in the Visual Studio UI) so it is a fairly reliable
83          * indication that PNG_IMPEXP needs to be set to the DLL export
84          * attributes.
85          */
86#        define PNG_BUILD_DLL
87#     else
88#        ifdef __DLL__
89            /* This is set by the Borland C system when compiling for a DLL
90             * (as above.)
91             */
92#           define PNG_BUILD_DLL
93#        else
94            /* Add additional compiler cases here. */
95#        endif
96#     endif
97#  endif
98#endif /* Setting PNG_BUILD_DLL if required */
99
100/* See pngconf.h for more details: the builder of the library may set this on
101 * the command line to the right thing for the specific compilation system or it
102 * may be automagically set above (at present we know of no system where it does
103 * need to be set on the command line.)
104 *
105 * PNG_IMPEXP must be set here when building the library to prevent pngconf.h
106 * setting it to the "import" setting for a DLL build.
107 */
108#ifndef PNG_IMPEXP
109#  ifdef PNG_BUILD_DLL
110#     define PNG_IMPEXP PNG_DLL_EXPORT
111#  else
112      /* Not building a DLL, or the DLL doesn't require specific export
113       * definitions.
114       */
115#     define PNG_IMPEXP
116#  endif
117#endif
118
119/* No warnings for private or deprecated functions in the build: */
120#ifndef PNG_DEPRECATED
121#  define PNG_DEPRECATED
122#endif
123#ifndef PNG_PRIVATE
124#  define PNG_PRIVATE
125#endif
126
127#include "png.h"
128#include "pnginfo.h"
129#include "pngstruct.h"
130
131/* pngconf.h does not set PNG_DLL_EXPORT unless it is required, so: */
132#ifndef PNG_DLL_EXPORT
133#  define PNG_DLL_EXPORT
134#endif
135
136/* SECURITY and SAFETY:
137 *
138 * By default libpng is built without any internal limits on image size,
139 * individual heap (png_malloc) allocations or the total amount of memory used.
140 * If PNG_SAFE_LIMITS_SUPPORTED is defined, however, the limits below are used
141 * (unless individually overridden).  These limits are believed to be fairly
142 * safe, but builders of secure systems should verify the values against the
143 * real system capabilities.
144 */
145
146#ifdef PNG_SAFE_LIMITS_SUPPORTED
147   /* 'safe' limits */
148#  ifndef PNG_USER_WIDTH_MAX
149#     define PNG_USER_WIDTH_MAX 1000000
150#  endif
151#  ifndef PNG_USER_HEIGHT_MAX
152#     define PNG_USER_HEIGHT_MAX 1000000
153#  endif
154#  ifndef PNG_USER_CHUNK_CACHE_MAX
155#     define PNG_USER_CHUNK_CACHE_MAX 128
156#  endif
157#  ifndef PNG_USER_CHUNK_MALLOC_MAX
158#     define PNG_USER_CHUNK_MALLOC_MAX 8000000
159#  endif
160#else
161   /* values for no limits */
162#  ifndef PNG_USER_WIDTH_MAX
163#     define PNG_USER_WIDTH_MAX 0x7fffffff
164#  endif
165#  ifndef PNG_USER_HEIGHT_MAX
166#     define PNG_USER_HEIGHT_MAX 0x7fffffff
167#  endif
168#  ifndef PNG_USER_CHUNK_CACHE_MAX
169#     define PNG_USER_CHUNK_CACHE_MAX 0
170#  endif
171#  ifndef PNG_USER_CHUNK_MALLOC_MAX
172#     define PNG_USER_CHUNK_MALLOC_MAX 0
173#  endif
174#endif
175
176/* This is used for 16 bit gamma tables - only the top level pointers are const,
177 * this could be changed:
178 */
179typedef PNG_CONST png_uint_16p FAR * png_const_uint_16pp;
180
181/* Added at libpng-1.2.9 */
182/* Moved to pngpriv.h at libpng-1.5.0 */
183
184/* config.h is created by and PNG_CONFIGURE_LIBPNG is set by the "configure"
185 * script.  We may need it here to get the correct configuration on things
186 * like limits.
187 */
188#ifdef PNG_CONFIGURE_LIBPNG
189#  ifdef HAVE_CONFIG_H
190#    include "config.h"
191#  endif
192#endif
193
194/* Moved to pngpriv.h at libpng-1.5.0 */
195/* NOTE: some of these may have been used in external applications as
196 * these definitions were exposed in pngconf.h prior to 1.5.
197 */
198
199/* If you are running on a machine where you cannot allocate more
200 * than 64K of memory at once, uncomment this.  While libpng will not
201 * normally need that much memory in a chunk (unless you load up a very
202 * large file), zlib needs to know how big of a chunk it can use, and
203 * libpng thus makes sure to check any memory allocation to verify it
204 * will fit into memory.
205 *
206 * zlib provides 'MAXSEG_64K' which, if defined, indicates the
207 * same limit and pngconf.h (already included) sets the limit
208 * if certain operating systems are detected.
209 */
210#if defined(MAXSEG_64K) && !defined(PNG_MAX_MALLOC_64K)
211#  define PNG_MAX_MALLOC_64K
212#endif
213
214#ifndef PNG_UNUSED
215/* Unused formal parameter warnings are silenced using the following macro
216 * which is expected to have no bad effects on performance (optimizing
217 * compilers will probably remove it entirely).  Note that if you replace
218 * it with something other than whitespace, you must include the terminating
219 * semicolon.
220 */
221#  define PNG_UNUSED(param) (void)param;
222#endif
223
224/* Just a little check that someone hasn't tried to define something
225 * contradictory.
226 */
227#if (PNG_ZBUF_SIZE > 65536L) && defined(PNG_MAX_MALLOC_64K)
228#  undef PNG_ZBUF_SIZE
229#  define PNG_ZBUF_SIZE 65536L
230#endif
231
232/* PNG_STATIC is used to mark internal file scope functions if they need to be
233 * accessed for implementation tests (see the code in tests/?*).
234 */
235#ifndef PNG_STATIC
236#   define PNG_STATIC static
237#endif
238
239/* C99 restrict is used where possible, to do this 'restrict' is defined as
240 * empty if we can't be sure it is supported.  configure builds have already
241 * done this work.
242 */
243#ifdef PNG_CONFIGURE_LIBPNG
244#  define PNG_RESTRICT restrict
245#else
246   /* Modern compilers support restrict, but assume not for anything not
247    * recognized here:
248    */
249#  if defined __GNUC__ || defined _MSC_VER || defined __WATCOMC__
250#     define PNG_RESTRICT restrict
251#  else
252#     define PNG_RESTRICT
253#  endif
254#endif
255
256/* If warnings or errors are turned off the code is disabled or redirected here.
257 * From 1.5.4 functions have been added to allow very limited formatting of
258 * error and warning messages - this code will also be disabled here.
259 */
260#ifdef PNG_WARNINGS_SUPPORTED
261#  define PNG_WARNING_PARAMETERS(p) png_warning_parameters p;
262#else
263#  define png_warning(s1,s2) ((void)(s1))
264#  define png_chunk_warning(s1,s2) ((void)(s1))
265#  define png_warning_parameter(p,number,string) ((void)0)
266#  define png_warning_parameter_unsigned(p,number,format,value) ((void)0)
267#  define png_warning_parameter_signed(p,number,format,value) ((void)0)
268#  define png_formatted_warning(pp,p,message) ((void)(pp))
269#  define PNG_WARNING_PARAMETERS(p)
270#endif
271#ifndef PNG_ERROR_TEXT_SUPPORTED
272#  define png_error(s1,s2) png_err(s1)
273#  define png_chunk_error(s1,s2) png_err(s1)
274#  define png_fixed_error(s1,s2) png_err(s1)
275#endif
276
277/* C allows up-casts from (void*) to any pointer and (const void*) to any
278 * pointer to a const object.  C++ regards this as a type error and requires an
279 * explicit, static, cast and provides the static_cast<> rune to ensure that
280 * const is not cast away.
281 */
282#ifdef __cplusplus
283#  define png_voidcast(type, value) static_cast<type>(value)
284#else
285#  define png_voidcast(type, value) (value)
286#endif /* __cplusplus */
287
288#ifndef PNG_EXTERN
289/* The functions exported by PNG_EXTERN are internal functions, which
290 * aren't usually used outside the library (as far as I know), so it is
291 * debatable if they should be exported at all.  In the future, when it
292 * is possible to have run-time registry of chunk-handling functions,
293 * some of these might be made available again.
294 *
295 * 1.5.7: turned the use of 'extern' back on, since it is localized to pngpriv.h
296 * it should be safe now (it is unclear why it was turned off.)
297 */
298#  define PNG_EXTERN extern
299#endif
300
301/* Some fixed point APIs are still required even if not exported because
302 * they get used by the corresponding floating point APIs.  This magic
303 * deals with this:
304 */
305#ifdef PNG_FIXED_POINT_SUPPORTED
306#  define PNGFAPI PNGAPI
307#else
308#  define PNGFAPI /* PRIVATE */
309#endif
310
311/* Other defines specific to compilers can go here.  Try to keep
312 * them inside an appropriate ifdef/endif pair for portability.
313 */
314#if defined(PNG_FLOATING_POINT_SUPPORTED) ||\
315    defined(PNG_FLOATING_ARITHMETIC_SUPPORTED)
316   /* png.c requires the following ANSI-C constants if the conversion of
317    * floating point to ASCII is implemented therein:
318    *
319    *  DBL_DIG  Maximum number of decimal digits (can be set to any constant)
320    *  DBL_MIN  Smallest normalized fp number (can be set to an arbitrary value)
321    *  DBL_MAX  Maximum floating point number (can be set to an arbitrary value)
322    */
323#  include <float.h>
324
325#  if (defined(__MWERKS__) && defined(macintosh)) || defined(applec) || \
326    defined(THINK_C) || defined(__SC__) || defined(TARGET_OS_MAC)
327     /* We need to check that <math.h> hasn't already been included earlier
328      * as it seems it doesn't agree with <fp.h>, yet we should really use
329      * <fp.h> if possible.
330      */
331#    if !defined(__MATH_H__) && !defined(__MATH_H) && !defined(__cmath__)
332#      include <fp.h>
333#    endif
334#  else
335#    include <math.h>
336#  endif
337#  if defined(_AMIGA) && defined(__SASC) && defined(_M68881)
338     /* Amiga SAS/C: We must include builtin FPU functions when compiling using
339      * MATH=68881
340      */
341#    include <m68881.h>
342#  endif
343#endif
344
345/* This provides the non-ANSI (far) memory allocation routines. */
346#if defined(__TURBOC__) && defined(__MSDOS__)
347#  include <mem.h>
348#  include <alloc.h>
349#endif
350
351#if defined(WIN32) || defined(_Windows) || defined(_WINDOWS) || \
352    defined(_WIN32) || defined(__WIN32__)
353#  include <windows.h>  /* defines _WINDOWS_ macro */
354#endif
355
356/* Moved here around 1.5.0beta36 from pngconf.h */
357/* Users may want to use these so they are not private.  Any library
358 * functions that are passed far data must be model-independent.
359 */
360
361/* Memory model/platform independent fns */
362#ifndef PNG_ABORT
363#  ifdef _WINDOWS_
364#    define PNG_ABORT() ExitProcess(0)
365#  else
366#    define PNG_ABORT() abort()
367#  endif
368#endif
369
370#ifdef USE_FAR_KEYWORD
371/* Use this to make far-to-near assignments */
372#  define CHECK   1
373#  define NOCHECK 0
374#  define CVT_PTR(ptr) (png_far_to_near(png_ptr,ptr,CHECK))
375#  define CVT_PTR_NOCHECK(ptr) (png_far_to_near(png_ptr,ptr,NOCHECK))
376#  define png_strlen  _fstrlen
377#  define png_memcmp  _fmemcmp    /* SJT: added */
378#  define png_memcpy  _fmemcpy
379#  define png_memset  _fmemset
380#else
381#  ifdef _WINDOWS_  /* Favor Windows over C runtime fns */
382#    define CVT_PTR(ptr)         (ptr)
383#    define CVT_PTR_NOCHECK(ptr) (ptr)
384#    define png_strlen  lstrlenA
385#    define png_memcmp  memcmp
386#    define png_memcpy  CopyMemory
387#    define png_memset  memset
388#  else
389#    define CVT_PTR(ptr)         (ptr)
390#    define CVT_PTR_NOCHECK(ptr) (ptr)
391#    define png_strlen  strlen
392#    define png_memcmp  memcmp      /* SJT: added */
393#    define png_memcpy  memcpy
394#    define png_memset  memset
395#  endif
396#endif
397
398/* These macros may need to be architecture dependent. */
399#define PNG_ALIGN_NONE   0 /* do not use data alignment */
400#define PNG_ALIGN_ALWAYS 1 /* assume unaligned accesses are OK */
401#ifdef offsetof
402#  define PNG_ALIGN_OFFSET 2 /* use offsetof to determine alignment */
403#else
404#  define PNG_ALIGN_OFFSET -1 /* prevent the use of this */
405#endif
406#define PNG_ALIGN_SIZE   3 /* use sizeof to determine alignment */
407
408#ifndef PNG_ALIGN_TYPE
409   /* Default to using aligned access optimizations and requiring alignment to a
410    * multiple of the data type size.  Override in a compiler specific fashion
411    * if necessary by inserting tests here:
412    */
413#  define PNG_ALIGN_TYPE PNG_ALIGN_SIZE
414#endif
415
416#if PNG_ALIGN_TYPE == PNG_ALIGN_SIZE
417   /* This is used because in some compiler implementations non-aligned
418    * structure members are supported, so the offsetof approach below fails.
419    * Set PNG_ALIGN_TO_SIZE=0 for compiler combinations where unaligned access
420    * is good for performance.  Do not do this unless you have tested the result
421    * and understand it.
422    */
423#  define png_alignof(type) (sizeof (type))
424#else
425#  if PNG_ALIGN_TYPE == PNG_ALIGN_OFFSET
426#     define png_alignof(type) offsetof(struct{char c; type t;}, t)
427#  else
428#     if PNG_ALIGN_TYPE == PNG_ALIGN_ALWAYS
429#        define png_alignof(type) (1)
430#     endif
431      /* Else leave png_alignof undefined to prevent use thereof */
432#  endif
433#endif
434
435/* This implicitly assumes alignment is always to a power of 2. */
436#ifdef png_alignof
437#  define png_isaligned(ptr, type)\
438   ((((const char*)ptr-(const char*)0) & (png_alignof(type)-1)) == 0)
439#else
440#  define png_isaligned(ptr, type) 0
441#endif
442
443/* End of memory model/platform independent support */
444/* End of 1.5.0beta36 move from pngconf.h */
445
446/* CONSTANTS and UTILITY MACROS
447 * These are used internally by libpng and not exposed in the API
448 */
449
450/* Various modes of operation.  Note that after an init, mode is set to
451 * zero automatically when the structure is created.  Three of these
452 * are defined in png.h because they need to be visible to applications
453 * that call png_set_unknown_chunk().
454 */
455/* #define PNG_HAVE_IHDR            0x01 (defined in png.h) */
456/* #define PNG_HAVE_PLTE            0x02 (defined in png.h) */
457#define PNG_HAVE_IDAT               0x04
458/* #define PNG_AFTER_IDAT           0x08 (defined in png.h) */
459#define PNG_HAVE_IEND               0x10
460#define PNG_HAVE_gAMA               0x20
461#define PNG_HAVE_cHRM               0x40
462#define PNG_HAVE_sRGB               0x80
463#define PNG_HAVE_CHUNK_HEADER      0x100
464#define PNG_WROTE_tIME             0x200
465#define PNG_WROTE_INFO_BEFORE_PLTE 0x400
466#define PNG_BACKGROUND_IS_GRAY     0x800
467#define PNG_HAVE_PNG_SIGNATURE    0x1000
468#define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000 /* Have another chunk after IDAT */
469#define PNG_HAVE_iCCP             0x4000
470
471/* Flags for the transformations the PNG library does on the image data */
472#define PNG_BGR                 0x0001
473#define PNG_INTERLACE           0x0002
474#define PNG_PACK                0x0004
475#define PNG_SHIFT               0x0008
476#define PNG_SWAP_BYTES          0x0010
477#define PNG_INVERT_MONO         0x0020
478#define PNG_QUANTIZE            0x0040
479#define PNG_COMPOSE             0x0080     /* Was PNG_BACKGROUND */
480#define PNG_BACKGROUND_EXPAND   0x0100
481#define PNG_EXPAND_16           0x0200     /* Added to libpng 1.5.2 */
482#define PNG_16_TO_8             0x0400     /* Becomes 'chop' in 1.5.4 */
483#define PNG_RGBA                0x0800
484#define PNG_EXPAND              0x1000
485#define PNG_GAMMA               0x2000
486#define PNG_GRAY_TO_RGB         0x4000
487#define PNG_FILLER              0x8000
488#define PNG_PACKSWAP           0x10000
489#define PNG_SWAP_ALPHA         0x20000
490#define PNG_STRIP_ALPHA        0x40000
491#define PNG_INVERT_ALPHA       0x80000
492#define PNG_USER_TRANSFORM    0x100000
493#define PNG_RGB_TO_GRAY_ERR   0x200000
494#define PNG_RGB_TO_GRAY_WARN  0x400000
495#define PNG_RGB_TO_GRAY       0x600000 /* two bits, RGB_TO_GRAY_ERR|WARN */
496#define PNG_ENCODE_ALPHA      0x800000 /* Added to libpng-1.5.4 */
497#define PNG_ADD_ALPHA         0x1000000 /* Added to libpng-1.2.7 */
498#define PNG_EXPAND_tRNS       0x2000000 /* Added to libpng-1.2.9 */
499#define PNG_SCALE_16_TO_8     0x4000000 /* Added to libpng-1.5.4 */
500                       /*   0x8000000 unused */
501                       /*  0x10000000 unused */
502                       /*  0x20000000 unused */
503                       /*  0x40000000 unused */
504/* Flags for png_create_struct */
505#define PNG_STRUCT_PNG   0x0001
506#define PNG_STRUCT_INFO  0x0002
507
508/* Scaling factor for filter heuristic weighting calculations */
509#define PNG_WEIGHT_FACTOR (1<<(PNG_WEIGHT_SHIFT))
510#define PNG_COST_FACTOR (1<<(PNG_COST_SHIFT))
511
512/* Flags for the png_ptr->flags rather than declaring a byte for each one */
513#define PNG_FLAG_ZLIB_CUSTOM_STRATEGY     0x0001
514#define PNG_FLAG_ZLIB_CUSTOM_LEVEL        0x0002
515#define PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL    0x0004
516#define PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS  0x0008
517#define PNG_FLAG_ZLIB_CUSTOM_METHOD       0x0010
518#define PNG_FLAG_ZLIB_FINISHED            0x0020
519#define PNG_FLAG_ROW_INIT                 0x0040
520#define PNG_FLAG_FILLER_AFTER             0x0080
521#define PNG_FLAG_CRC_ANCILLARY_USE        0x0100
522#define PNG_FLAG_CRC_ANCILLARY_NOWARN     0x0200
523#define PNG_FLAG_CRC_CRITICAL_USE         0x0400
524#define PNG_FLAG_CRC_CRITICAL_IGNORE      0x0800
525#define PNG_FLAG_ASSUME_sRGB              0x1000  /* Added to libpng-1.5.4 */
526#define PNG_FLAG_OPTIMIZE_ALPHA           0x2000  /* Added to libpng-1.5.4 */
527#define PNG_FLAG_DETECT_UNINITIALIZED     0x4000  /* Added to libpng-1.5.4 */
528#define PNG_FLAG_KEEP_UNKNOWN_CHUNKS      0x8000
529#define PNG_FLAG_KEEP_UNSAFE_CHUNKS       0x10000
530#define PNG_FLAG_LIBRARY_MISMATCH         0x20000
531#define PNG_FLAG_STRIP_ERROR_NUMBERS      0x40000
532#define PNG_FLAG_STRIP_ERROR_TEXT         0x80000
533#define PNG_FLAG_MALLOC_NULL_MEM_OK       0x100000
534                                  /*      0x200000  unused */
535                                  /*      0x400000  unused */
536#define PNG_FLAG_BENIGN_ERRORS_WARN       0x800000  /* Added to libpng-1.4.0 */
537#define PNG_FLAG_ZTXT_CUSTOM_STRATEGY    0x1000000  /* 5 lines added */
538#define PNG_FLAG_ZTXT_CUSTOM_LEVEL       0x2000000  /* to libpng-1.5.4 */
539#define PNG_FLAG_ZTXT_CUSTOM_MEM_LEVEL   0x4000000
540#define PNG_FLAG_ZTXT_CUSTOM_WINDOW_BITS 0x8000000
541#define PNG_FLAG_ZTXT_CUSTOM_METHOD      0x10000000
542                                  /*     0x20000000  unused */
543                                  /*     0x40000000  unused */
544
545#define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \
546                                     PNG_FLAG_CRC_ANCILLARY_NOWARN)
547
548#define PNG_FLAG_CRC_CRITICAL_MASK  (PNG_FLAG_CRC_CRITICAL_USE | \
549                                     PNG_FLAG_CRC_CRITICAL_IGNORE)
550
551#define PNG_FLAG_CRC_MASK           (PNG_FLAG_CRC_ANCILLARY_MASK | \
552                                     PNG_FLAG_CRC_CRITICAL_MASK)
553
554/* zlib.h declares a magic type 'uInt' that limits the amount of data that zlib
555 * can handle at once.  This type need be no larger than 16 bits (so maximum of
556 * 65535), this define allows us to discover how big it is, but limited by the
557 * maximuum for png_size_t.  The value can be overriden in a library build
558 * (pngusr.h, or set it in CPPFLAGS) and it works to set it to a considerably
559 * lower value (e.g. 255 works).  A lower value may help memory usage (slightly)
560 * and may even improve performance on some systems (and degrade it on others.)
561 */
562#ifndef ZLIB_IO_MAX
563#  define ZLIB_IO_MAX ((uInt)-1)
564#endif
565
566/* Save typing and make code easier to understand */
567
568#define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \
569   abs((int)((c1).green) - (int)((c2).green)) + \
570   abs((int)((c1).blue) - (int)((c2).blue)))
571
572/* Added to libpng-1.2.6 JB */
573#define PNG_ROWBYTES(pixel_bits, width) \
574    ((pixel_bits) >= 8 ? \
575    ((png_size_t)(width) * (((png_size_t)(pixel_bits)) >> 3)) : \
576    (( ((png_size_t)(width) * ((png_size_t)(pixel_bits))) + 7) >> 3) )
577
578/* PNG_OUT_OF_RANGE returns true if value is outside the range
579 * ideal-delta..ideal+delta.  Each argument is evaluated twice.
580 * "ideal" and "delta" should be constants, normally simple
581 * integers, "value" a variable. Added to libpng-1.2.6 JB
582 */
583#define PNG_OUT_OF_RANGE(value, ideal, delta) \
584   ( (value) < (ideal)-(delta) || (value) > (ideal)+(delta) )
585
586/* Conversions between fixed and floating point, only defined if
587 * required (to make sure the code doesn't accidentally use float
588 * when it is supposedly disabled.)
589 */
590#ifdef PNG_FLOATING_POINT_SUPPORTED
591/* The floating point conversion can't overflow, though it can and
592 * does lose accuracy relative to the original fixed point value.
593 * In practice this doesn't matter because png_fixed_point only
594 * stores numbers with very low precision.  The png_ptr and s
595 * arguments are unused by default but are there in case error
596 * checking becomes a requirement.
597 */
598#define png_float(png_ptr, fixed, s) (.00001 * (fixed))
599
600/* The fixed point conversion performs range checking and evaluates
601 * its argument multiple times, so must be used with care.  The
602 * range checking uses the PNG specification values for a signed
603 * 32 bit fixed point value except that the values are deliberately
604 * rounded-to-zero to an integral value - 21474 (21474.83 is roughly
605 * (2^31-1) * 100000). 's' is a string that describes the value being
606 * converted.
607 *
608 * NOTE: this macro will raise a png_error if the range check fails,
609 * therefore it is normally only appropriate to use this on values
610 * that come from API calls or other sources where an out of range
611 * error indicates a programming error, not a data error!
612 *
613 * NOTE: by default this is off - the macro is not used - because the
614 * function call saves a lot of code.
615 */
616#ifdef PNG_FIXED_POINT_MACRO_SUPPORTED
617#define png_fixed(png_ptr, fp, s) ((fp) <= 21474 && (fp) >= -21474 ?\
618    ((png_fixed_point)(100000 * (fp))) : (png_fixed_error(png_ptr, s),0))
619#else
620PNG_EXTERN png_fixed_point png_fixed PNGARG((png_structp png_ptr, double fp,
621   png_const_charp text));
622#endif
623#endif
624
625/* Constants for known chunk types.  If you need to add a chunk, define the name
626 * here.  For historical reasons these constants have the form png_<name>; i.e.
627 * the prefix is lower case.  Please use decimal values as the parameters to
628 * match the ISO PNG specification and to avoid relying on the C locale
629 * interpretation of character values.
630 *
631 * Prior to 1.5.6 these constants were strings, as of 1.5.6 png_uint_32 values
632 * are computed and a new macro (PNG_STRING_FROM_CHUNK) added to allow a string
633 * to be generated if required.
634 *
635 * PNG_32b correctly produces a value shifted by up to 24 bits, even on
636 * architectures where (int) is only 16 bits.
637 */
638#define PNG_32b(b,s) ((png_uint_32)(b) << (s))
639#define PNG_CHUNK(b1,b2,b3,b4) \
640   (PNG_32b(b1,24) | PNG_32b(b2,16) | PNG_32b(b3,8) | PNG_32b(b4,0))
641
642#define png_IHDR PNG_CHUNK( 73,  72,  68,  82)
643#define png_IDAT PNG_CHUNK( 73,  68,  65,  84)
644#define png_IEND PNG_CHUNK( 73,  69,  78,  68)
645#define png_PLTE PNG_CHUNK( 80,  76,  84,  69)
646#define png_bKGD PNG_CHUNK( 98,  75,  71,  68)
647#define png_cHRM PNG_CHUNK( 99,  72,  82,  77)
648#define png_gAMA PNG_CHUNK(103,  65,  77,  65)
649#define png_hIST PNG_CHUNK(104,  73,  83,  84)
650#define png_iCCP PNG_CHUNK(105,  67,  67,  80)
651#define png_iTXt PNG_CHUNK(105,  84,  88, 116)
652#define png_oFFs PNG_CHUNK(111,  70,  70, 115)
653#define png_pCAL PNG_CHUNK(112,  67,  65,  76)
654#define png_sCAL PNG_CHUNK(115,  67,  65,  76)
655#define png_pHYs PNG_CHUNK(112,  72,  89, 115)
656#define png_sBIT PNG_CHUNK(115,  66,  73,  84)
657#define png_sPLT PNG_CHUNK(115,  80,  76,  84)
658#define png_sRGB PNG_CHUNK(115,  82,  71,  66)
659#define png_sTER PNG_CHUNK(115,  84,  69,  82)
660#define png_tEXt PNG_CHUNK(116,  69,  88, 116)
661#define png_tIME PNG_CHUNK(116,  73,  77,  69)
662#define png_tRNS PNG_CHUNK(116,  82,  78,  83)
663#define png_zTXt PNG_CHUNK(122,  84,  88, 116)
664
665/* The following will work on (signed char*) strings, whereas the get_uint_32
666 * macro will fail on top-bit-set values because of the sign extension.
667 */
668#define PNG_CHUNK_FROM_STRING(s)\
669   PNG_CHUNK(0xff&(s)[0], 0xff&(s)[1], 0xff&(s)[2], 0xff&(s)[3])
670
671/* This uses (char), not (png_byte) to avoid warnings on systems where (char) is
672 * signed and the argument is a (char[])  This macro will fail miserably on
673 * systems where (char) is more than 8 bits.
674 */
675#define PNG_STRING_FROM_CHUNK(s,c)\
676   (void)(((char*)(s))[0]=(char)((c)>>24), ((char*)(s))[1]=(char)((c)>>16),\
677   ((char*)(s))[2]=(char)((c)>>8), ((char*)(s))[3]=(char)((c)))
678
679/* Do the same but terminate with a null character. */
680#define PNG_CSTRING_FROM_CHUNK(s,c)\
681   (void)(PNG_STRING_FROM_CHUNK(s,c), ((char*)(s))[4] = 0)
682
683/* Test on flag values as defined in the spec (section 5.4): */
684#define PNG_CHUNK_ANCILLIARY(c)   (1 & ((c) >> 29))
685#define PNG_CHUNK_CRITICAL(c)     (!PNG_CHUNK_ANCILLIARY(c))
686#define PNG_CHUNK_PRIVATE(c)      (1 & ((c) >> 21))
687#define PNG_CHUNK_RESERVED(c)     (1 & ((c) >> 13))
688#define PNG_CHUNK_SAFE_TO_COPY(c) (1 & ((c) >>  5))
689
690/* Gamma values (new at libpng-1.5.4): */
691#define PNG_GAMMA_MAC_OLD 151724  /* Assume '1.8' is really 2.2/1.45! */
692#define PNG_GAMMA_MAC_INVERSE 65909
693#define PNG_GAMMA_sRGB_INVERSE 45455
694
695
696/* Inhibit C++ name-mangling for libpng functions but not for system calls. */
697#ifdef __cplusplus
698extern "C" {
699#endif /* __cplusplus */
700
701/* These functions are used internally in the code.  They generally
702 * shouldn't be used unless you are writing code to add or replace some
703 * functionality in libpng.  More information about most functions can
704 * be found in the files where the functions are located.
705 */
706
707/* Check the user version string for compatibility, returns false if the version
708 * numbers aren't compatible.
709 */
710PNG_EXTERN int png_user_version_check(png_structp png_ptr,
711   png_const_charp user_png_ver);
712
713/* Allocate memory for an internal libpng struct */
714PNG_EXTERN PNG_FUNCTION(png_voidp,png_create_struct,PNGARG((int type)),
715   PNG_ALLOCATED);
716
717/* Free memory from internal libpng struct */
718PNG_EXTERN void png_destroy_struct PNGARG((png_voidp struct_ptr));
719
720PNG_EXTERN PNG_FUNCTION(png_voidp,png_create_struct_2,
721   PNGARG((int type, png_malloc_ptr malloc_fn, png_voidp mem_ptr)),
722   PNG_ALLOCATED);
723PNG_EXTERN void png_destroy_struct_2 PNGARG((png_voidp struct_ptr,
724    png_free_ptr free_fn, png_voidp mem_ptr));
725
726/* Free any memory that info_ptr points to and reset struct. */
727PNG_EXTERN void png_info_destroy PNGARG((png_structp png_ptr,
728    png_infop info_ptr));
729
730/* Function to allocate memory for zlib.  PNGAPI is disallowed. */
731PNG_EXTERN PNG_FUNCTION(voidpf,png_zalloc,PNGARG((voidpf png_ptr, uInt items,
732   uInt size)),PNG_ALLOCATED);
733
734/* Function to free memory for zlib.  PNGAPI is disallowed. */
735PNG_EXTERN void png_zfree PNGARG((voidpf png_ptr, voidpf ptr));
736
737/* Next four functions are used internally as callbacks.  PNGCBAPI is required
738 * but not PNG_EXPORT.  PNGAPI added at libpng version 1.2.3, changed to
739 * PNGCBAPI at 1.5.0
740 */
741
742PNG_EXTERN void PNGCBAPI png_default_read_data PNGARG((png_structp png_ptr,
743    png_bytep data, png_size_t length));
744
745#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
746PNG_EXTERN void PNGCBAPI png_push_fill_buffer PNGARG((png_structp png_ptr,
747    png_bytep buffer, png_size_t length));
748#endif
749
750PNG_EXTERN void PNGCBAPI png_default_write_data PNGARG((png_structp png_ptr,
751    png_bytep data, png_size_t length));
752
753#ifdef PNG_WRITE_FLUSH_SUPPORTED
754#  ifdef PNG_STDIO_SUPPORTED
755PNG_EXTERN void PNGCBAPI png_default_flush PNGARG((png_structp png_ptr));
756#  endif
757#endif
758
759/* Reset the CRC variable */
760PNG_EXTERN void png_reset_crc PNGARG((png_structp png_ptr));
761
762/* Write the "data" buffer to whatever output you are using */
763PNG_EXTERN void png_write_data PNGARG((png_structp png_ptr,
764    png_const_bytep data, png_size_t length));
765
766/* Read and check the PNG file signature */
767PNG_EXTERN void png_read_sig PNGARG((png_structp png_ptr, png_infop info_ptr));
768
769/* Read the chunk header (length + type name) */
770PNG_EXTERN png_uint_32 png_read_chunk_header PNGARG((png_structp png_ptr));
771
772/* Read data from whatever input you are using into the "data" buffer */
773PNG_EXTERN void png_read_data PNGARG((png_structp png_ptr, png_bytep data,
774    png_size_t length));
775
776/* Read bytes into buf, and update png_ptr->crc */
777PNG_EXTERN void png_crc_read PNGARG((png_structp png_ptr, png_bytep buf,
778    png_size_t length));
779
780/* Decompress data in a chunk that uses compression */
781#if defined(PNG_READ_COMPRESSED_TEXT_SUPPORTED)
782PNG_EXTERN void png_decompress_chunk PNGARG((png_structp png_ptr,
783    int comp_type, png_size_t chunklength, png_size_t prefix_length,
784    png_size_t *data_length));
785#endif
786
787/* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */
788PNG_EXTERN int png_crc_finish PNGARG((png_structp png_ptr, png_uint_32 skip));
789
790/* Read the CRC from the file and compare it to the libpng calculated CRC */
791PNG_EXTERN int png_crc_error PNGARG((png_structp png_ptr));
792
793/* Calculate the CRC over a section of data.  Note that we are only
794 * passing a maximum of 64K on systems that have this as a memory limit,
795 * since this is the maximum buffer size we can specify.
796 */
797PNG_EXTERN void png_calculate_crc PNGARG((png_structp png_ptr,
798    png_const_bytep ptr, png_size_t length));
799
800#ifdef PNG_WRITE_FLUSH_SUPPORTED
801PNG_EXTERN void png_flush PNGARG((png_structp png_ptr));
802#endif
803
804/* Write various chunks */
805
806/* Write the IHDR chunk, and update the png_struct with the necessary
807 * information.
808 */
809PNG_EXTERN void png_write_IHDR PNGARG((png_structp png_ptr, png_uint_32 width,
810    png_uint_32 height,
811    int bit_depth, int color_type, int compression_method, int filter_method,
812    int interlace_method));
813
814PNG_EXTERN void png_write_PLTE PNGARG((png_structp png_ptr,
815    png_const_colorp palette, png_uint_32 num_pal));
816
817PNG_EXTERN void png_write_IDAT PNGARG((png_structp png_ptr, png_bytep data,
818    png_size_t length));
819
820PNG_EXTERN void png_write_IEND PNGARG((png_structp png_ptr));
821
822#ifdef PNG_WRITE_gAMA_SUPPORTED
823#  ifdef PNG_FLOATING_POINT_SUPPORTED
824PNG_EXTERN void png_write_gAMA PNGARG((png_structp png_ptr, double file_gamma));
825#  endif
826#  ifdef PNG_FIXED_POINT_SUPPORTED
827PNG_EXTERN void png_write_gAMA_fixed PNGARG((png_structp png_ptr,
828    png_fixed_point file_gamma));
829#  endif
830#endif
831
832#ifdef PNG_WRITE_sBIT_SUPPORTED
833PNG_EXTERN void png_write_sBIT PNGARG((png_structp png_ptr,
834    png_const_color_8p sbit, int color_type));
835#endif
836
837#ifdef PNG_WRITE_cHRM_SUPPORTED
838#  ifdef PNG_FLOATING_POINT_SUPPORTED
839PNG_EXTERN void png_write_cHRM PNGARG((png_structp png_ptr,
840    double white_x, double white_y,
841    double red_x, double red_y, double green_x, double green_y,
842    double blue_x, double blue_y));
843#  endif
844PNG_EXTERN void png_write_cHRM_fixed PNGARG((png_structp png_ptr,
845    png_fixed_point int_white_x, png_fixed_point int_white_y,
846    png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
847    int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
848    png_fixed_point int_blue_y));
849#endif
850
851#ifdef PNG_WRITE_sRGB_SUPPORTED
852PNG_EXTERN void png_write_sRGB PNGARG((png_structp png_ptr,
853    int intent));
854#endif
855
856#ifdef PNG_WRITE_iCCP_SUPPORTED
857PNG_EXTERN void png_write_iCCP PNGARG((png_structp png_ptr,
858    png_const_charp name, int compression_type,
859    png_const_charp profile, int proflen));
860   /* Note to maintainer: profile should be png_bytep */
861#endif
862
863#ifdef PNG_WRITE_sPLT_SUPPORTED
864PNG_EXTERN void png_write_sPLT PNGARG((png_structp png_ptr,
865    png_const_sPLT_tp palette));
866#endif
867
868#ifdef PNG_WRITE_tRNS_SUPPORTED
869PNG_EXTERN void png_write_tRNS PNGARG((png_structp png_ptr,
870    png_const_bytep trans, png_const_color_16p values, int number,
871    int color_type));
872#endif
873
874#ifdef PNG_WRITE_bKGD_SUPPORTED
875PNG_EXTERN void png_write_bKGD PNGARG((png_structp png_ptr,
876    png_const_color_16p values, int color_type));
877#endif
878
879#ifdef PNG_WRITE_hIST_SUPPORTED
880PNG_EXTERN void png_write_hIST PNGARG((png_structp png_ptr,
881    png_const_uint_16p hist, int num_hist));
882#endif
883
884/* Chunks that have keywords */
885#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \
886    defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
887PNG_EXTERN png_size_t png_check_keyword PNGARG((png_structp png_ptr,
888    png_const_charp key, png_charpp new_key));
889#endif
890
891#ifdef PNG_WRITE_tEXt_SUPPORTED
892PNG_EXTERN void png_write_tEXt PNGARG((png_structp png_ptr, png_const_charp key,
893    png_const_charp text, png_size_t text_len));
894#endif
895
896#ifdef PNG_WRITE_zTXt_SUPPORTED
897PNG_EXTERN void png_write_zTXt PNGARG((png_structp png_ptr, png_const_charp key,
898    png_const_charp text, png_size_t text_len, int compression));
899#endif
900
901#ifdef PNG_WRITE_iTXt_SUPPORTED
902PNG_EXTERN void png_write_iTXt PNGARG((png_structp png_ptr,
903    int compression, png_const_charp key, png_const_charp lang,
904    png_const_charp lang_key, png_const_charp text));
905#endif
906
907#ifdef PNG_TEXT_SUPPORTED  /* Added at version 1.0.14 and 1.2.4 */
908PNG_EXTERN int png_set_text_2 PNGARG((png_structp png_ptr,
909    png_infop info_ptr, png_const_textp text_ptr, int num_text));
910#endif
911
912#ifdef PNG_WRITE_oFFs_SUPPORTED
913PNG_EXTERN void png_write_oFFs PNGARG((png_structp png_ptr,
914    png_int_32 x_offset, png_int_32 y_offset, int unit_type));
915#endif
916
917#ifdef PNG_WRITE_pCAL_SUPPORTED
918PNG_EXTERN void png_write_pCAL PNGARG((png_structp png_ptr, png_charp purpose,
919    png_int_32 X0, png_int_32 X1, int type, int nparams,
920    png_const_charp units, png_charpp params));
921#endif
922
923#ifdef PNG_WRITE_pHYs_SUPPORTED
924PNG_EXTERN void png_write_pHYs PNGARG((png_structp png_ptr,
925    png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit,
926    int unit_type));
927#endif
928
929#ifdef PNG_WRITE_tIME_SUPPORTED
930PNG_EXTERN void png_write_tIME PNGARG((png_structp png_ptr,
931    png_const_timep mod_time));
932#endif
933
934#ifdef PNG_WRITE_sCAL_SUPPORTED
935PNG_EXTERN void png_write_sCAL_s PNGARG((png_structp png_ptr,
936    int unit, png_const_charp width, png_const_charp height));
937#endif
938
939/* Called when finished processing a row of data */
940PNG_EXTERN void png_write_finish_row PNGARG((png_structp png_ptr));
941
942/* Internal use only.   Called before first row of data */
943PNG_EXTERN void png_write_start_row PNGARG((png_structp png_ptr));
944
945/* Combine a row of data, dealing with alpha, etc. if requested.  'row' is an
946 * array of png_ptr->width pixels.  If the image is not interlaced or this
947 * is the final pass this just does a png_memcpy, otherwise the "display" flag
948 * is used to determine whether to copy pixels that are not in the current pass.
949 *
950 * Because 'png_do_read_interlace' (below) replicates pixels this allows this
951 * function to achieve the documented 'blocky' appearance during interlaced read
952 * if display is 1 and the 'sparkle' appearance, where existing pixels in 'row'
953 * are not changed if they are not in the current pass, when display is 0.
954 *
955 * 'display' must be 0 or 1, otherwise the memcpy will be done regardless.
956 *
957 * The API always reads from the png_struct row buffer and always assumes that
958 * it is full width (png_do_read_interlace has already been called.)
959 *
960 * This function is only ever used to write to row buffers provided by the
961 * caller of the relevant libpng API and the row must have already been
962 * transformed by the read transformations.
963 *
964 * The PNG_USE_COMPILE_TIME_MASKS option causes generation of pre-computed
965 * bitmasks for use within the code, otherwise runtime generated masks are used.
966 * The default is compile time masks.
967 */
968#ifndef PNG_USE_COMPILE_TIME_MASKS
969#  define PNG_USE_COMPILE_TIME_MASKS 1
970#endif
971PNG_EXTERN void png_combine_row PNGARG((png_structp png_ptr, png_bytep row,
972    int display));
973
974#ifdef PNG_READ_INTERLACING_SUPPORTED
975/* Expand an interlaced row: the 'row_info' describes the pass data that has
976 * been read in and must correspond to the pixels in 'row', the pixels are
977 * expanded (moved apart) in 'row' to match the final layout, when doing this
978 * the pixels are *replicated* to the intervening space.  This is essential for
979 * the correct operation of png_combine_row, above.
980 */
981PNG_EXTERN void png_do_read_interlace PNGARG((png_row_infop row_info,
982    png_bytep row, int pass, png_uint_32 transformations));
983#endif
984
985/* GRR TO DO (2.0 or whenever):  simplify other internal calling interfaces */
986
987#ifdef PNG_WRITE_INTERLACING_SUPPORTED
988/* Grab pixels out of a row for an interlaced pass */
989PNG_EXTERN void png_do_write_interlace PNGARG((png_row_infop row_info,
990    png_bytep row, int pass));
991#endif
992
993/* Unfilter a row: check the filter value before calling this, there is no point
994 * calling it for PNG_FILTER_VALUE_NONE.
995 */
996PNG_EXTERN void png_read_filter_row PNGARG((png_structp pp, png_row_infop row_info,
997    png_bytep row, png_const_bytep prev_row, int filter));
998
999PNG_EXTERN void png_read_filter_row_up_neon PNGARG((png_row_infop row_info,
1000    png_bytep row, png_const_bytep prev_row));
1001PNG_EXTERN void png_read_filter_row_sub3_neon PNGARG((png_row_infop row_info,
1002    png_bytep row, png_const_bytep prev_row));
1003PNG_EXTERN void png_read_filter_row_sub4_neon PNGARG((png_row_infop row_info,
1004    png_bytep row, png_const_bytep prev_row));
1005PNG_EXTERN void png_read_filter_row_avg3_neon PNGARG((png_row_infop row_info,
1006    png_bytep row, png_const_bytep prev_row));
1007PNG_EXTERN void png_read_filter_row_avg4_neon PNGARG((png_row_infop row_info,
1008    png_bytep row, png_const_bytep prev_row));
1009PNG_EXTERN void png_read_filter_row_paeth3_neon PNGARG((png_row_infop row_info,
1010    png_bytep row, png_const_bytep prev_row));
1011PNG_EXTERN void png_read_filter_row_paeth4_neon PNGARG((png_row_infop row_info,
1012    png_bytep row, png_const_bytep prev_row));
1013
1014/* Choose the best filter to use and filter the row data */
1015PNG_EXTERN void png_write_find_filter PNGARG((png_structp png_ptr,
1016    png_row_infop row_info));
1017
1018/* Finish a row while reading, dealing with interlacing passes, etc. */
1019PNG_EXTERN void png_read_finish_row PNGARG((png_structp png_ptr));
1020
1021/* Initialize the row buffers, etc. */
1022PNG_EXTERN void png_read_start_row PNGARG((png_structp png_ptr));
1023
1024#ifdef PNG_READ_TRANSFORMS_SUPPORTED
1025/* Optional call to update the users info structure */
1026PNG_EXTERN void png_read_transform_info PNGARG((png_structp png_ptr,
1027    png_infop info_ptr));
1028#endif
1029
1030/* These are the functions that do the transformations */
1031#ifdef PNG_READ_FILLER_SUPPORTED
1032PNG_EXTERN void png_do_read_filler PNGARG((png_row_infop row_info,
1033    png_bytep row, png_uint_32 filler, png_uint_32 flags));
1034#endif
1035
1036#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
1037PNG_EXTERN void png_do_read_swap_alpha PNGARG((png_row_infop row_info,
1038    png_bytep row));
1039#endif
1040
1041#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
1042PNG_EXTERN void png_do_write_swap_alpha PNGARG((png_row_infop row_info,
1043    png_bytep row));
1044#endif
1045
1046#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
1047PNG_EXTERN void png_do_read_invert_alpha PNGARG((png_row_infop row_info,
1048    png_bytep row));
1049#endif
1050
1051#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
1052PNG_EXTERN void png_do_write_invert_alpha PNGARG((png_row_infop row_info,
1053    png_bytep row));
1054#endif
1055
1056#if defined(PNG_WRITE_FILLER_SUPPORTED) || \
1057    defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
1058PNG_EXTERN void png_do_strip_channel PNGARG((png_row_infop row_info,
1059    png_bytep row, int at_start));
1060#endif
1061
1062#ifdef PNG_16BIT_SUPPORTED
1063#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
1064PNG_EXTERN void png_do_swap PNGARG((png_row_infop row_info,
1065    png_bytep row));
1066#endif
1067#endif
1068
1069#if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
1070    defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1071PNG_EXTERN void png_do_packswap PNGARG((png_row_infop row_info,
1072    png_bytep row));
1073#endif
1074
1075#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1076PNG_EXTERN int png_do_rgb_to_gray PNGARG((png_structp png_ptr,
1077    png_row_infop row_info, png_bytep row));
1078#endif
1079
1080#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
1081PNG_EXTERN void png_do_gray_to_rgb PNGARG((png_row_infop row_info,
1082    png_bytep row));
1083#endif
1084
1085#ifdef PNG_READ_PACK_SUPPORTED
1086PNG_EXTERN void png_do_unpack PNGARG((png_row_infop row_info,
1087    png_bytep row));
1088#endif
1089
1090#ifdef PNG_READ_SHIFT_SUPPORTED
1091PNG_EXTERN void png_do_unshift PNGARG((png_row_infop row_info,
1092    png_bytep row, png_const_color_8p sig_bits));
1093#endif
1094
1095#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
1096PNG_EXTERN void png_do_invert PNGARG((png_row_infop row_info,
1097    png_bytep row));
1098#endif
1099
1100#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
1101PNG_EXTERN void png_do_scale_16_to_8 PNGARG((png_row_infop row_info,
1102    png_bytep row));
1103#endif
1104
1105#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
1106PNG_EXTERN void png_do_chop PNGARG((png_row_infop row_info,
1107    png_bytep row));
1108#endif
1109
1110#ifdef PNG_READ_QUANTIZE_SUPPORTED
1111PNG_EXTERN void png_do_quantize PNGARG((png_row_infop row_info,
1112    png_bytep row, png_const_bytep palette_lookup,
1113    png_const_bytep quantize_lookup));
1114
1115#  ifdef PNG_CORRECT_PALETTE_SUPPORTED
1116PNG_EXTERN void png_correct_palette PNGARG((png_structp png_ptr,
1117    png_colorp palette, int num_palette));
1118#  endif
1119#endif
1120
1121#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
1122PNG_EXTERN void png_do_bgr PNGARG((png_row_infop row_info,
1123    png_bytep row));
1124#endif
1125
1126#ifdef PNG_WRITE_PACK_SUPPORTED
1127PNG_EXTERN void png_do_pack PNGARG((png_row_infop row_info,
1128   png_bytep row, png_uint_32 bit_depth));
1129#endif
1130
1131#ifdef PNG_WRITE_SHIFT_SUPPORTED
1132PNG_EXTERN void png_do_shift PNGARG((png_row_infop row_info,
1133    png_bytep row, png_const_color_8p bit_depth));
1134#endif
1135
1136#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
1137    defined(PNG_READ_ALPHA_MODE_SUPPORTED)
1138PNG_EXTERN void png_do_compose PNGARG((png_row_infop row_info,
1139    png_bytep row, png_structp png_ptr));
1140#endif
1141
1142#ifdef PNG_READ_GAMMA_SUPPORTED
1143PNG_EXTERN void png_do_gamma PNGARG((png_row_infop row_info,
1144    png_bytep row, png_structp png_ptr));
1145#endif
1146
1147#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
1148PNG_EXTERN void png_do_encode_alpha PNGARG((png_row_infop row_info,
1149   png_bytep row, png_structp png_ptr));
1150#endif
1151
1152#ifdef PNG_READ_EXPAND_SUPPORTED
1153PNG_EXTERN void png_do_expand_palette PNGARG((png_row_infop row_info,
1154    png_bytep row, png_const_colorp palette, png_const_bytep trans,
1155    int num_trans));
1156PNG_EXTERN void png_do_expand PNGARG((png_row_infop row_info,
1157    png_bytep row, png_const_color_16p trans_color));
1158#endif
1159
1160#ifdef PNG_READ_EXPAND_16_SUPPORTED
1161PNG_EXTERN void png_do_expand_16 PNGARG((png_row_infop row_info,
1162    png_bytep row));
1163#endif
1164
1165/* The following decodes the appropriate chunks, and does error correction,
1166 * then calls the appropriate callback for the chunk if it is valid.
1167 */
1168
1169/* Decode the IHDR chunk */
1170PNG_EXTERN void png_handle_IHDR PNGARG((png_structp png_ptr, png_infop info_ptr,
1171    png_uint_32 length));
1172PNG_EXTERN void png_handle_PLTE PNGARG((png_structp png_ptr, png_infop info_ptr,
1173    png_uint_32 length));
1174PNG_EXTERN void png_handle_IEND PNGARG((png_structp png_ptr, png_infop info_ptr,
1175    png_uint_32 length));
1176
1177#ifdef PNG_READ_bKGD_SUPPORTED
1178PNG_EXTERN void png_handle_bKGD PNGARG((png_structp png_ptr, png_infop info_ptr,
1179    png_uint_32 length));
1180#endif
1181
1182#ifdef PNG_READ_cHRM_SUPPORTED
1183PNG_EXTERN void png_handle_cHRM PNGARG((png_structp png_ptr, png_infop info_ptr,
1184    png_uint_32 length));
1185#endif
1186
1187#ifdef PNG_READ_gAMA_SUPPORTED
1188PNG_EXTERN void png_handle_gAMA PNGARG((png_structp png_ptr, png_infop info_ptr,
1189    png_uint_32 length));
1190#endif
1191
1192#ifdef PNG_READ_hIST_SUPPORTED
1193PNG_EXTERN void png_handle_hIST PNGARG((png_structp png_ptr, png_infop info_ptr,
1194    png_uint_32 length));
1195#endif
1196
1197#ifdef PNG_READ_iCCP_SUPPORTED
1198PNG_EXTERN void png_handle_iCCP PNGARG((png_structp png_ptr, png_infop info_ptr,
1199    png_uint_32 length));
1200#endif /* PNG_READ_iCCP_SUPPORTED */
1201
1202#ifdef PNG_READ_iTXt_SUPPORTED
1203PNG_EXTERN void png_handle_iTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
1204    png_uint_32 length));
1205#endif
1206
1207#ifdef PNG_READ_oFFs_SUPPORTED
1208PNG_EXTERN void png_handle_oFFs PNGARG((png_structp png_ptr, png_infop info_ptr,
1209    png_uint_32 length));
1210#endif
1211
1212#ifdef PNG_READ_pCAL_SUPPORTED
1213PNG_EXTERN void png_handle_pCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
1214    png_uint_32 length));
1215#endif
1216
1217#ifdef PNG_READ_pHYs_SUPPORTED
1218PNG_EXTERN void png_handle_pHYs PNGARG((png_structp png_ptr, png_infop info_ptr,
1219    png_uint_32 length));
1220#endif
1221
1222#ifdef PNG_READ_sBIT_SUPPORTED
1223PNG_EXTERN void png_handle_sBIT PNGARG((png_structp png_ptr, png_infop info_ptr,
1224    png_uint_32 length));
1225#endif
1226
1227#ifdef PNG_READ_sCAL_SUPPORTED
1228PNG_EXTERN void png_handle_sCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
1229    png_uint_32 length));
1230#endif
1231
1232#ifdef PNG_READ_sPLT_SUPPORTED
1233PNG_EXTERN void png_handle_sPLT PNGARG((png_structp png_ptr, png_infop info_ptr,
1234    png_uint_32 length));
1235#endif /* PNG_READ_sPLT_SUPPORTED */
1236
1237#ifdef PNG_READ_sRGB_SUPPORTED
1238PNG_EXTERN void png_handle_sRGB PNGARG((png_structp png_ptr, png_infop info_ptr,
1239    png_uint_32 length));
1240#endif
1241
1242#ifdef PNG_READ_tEXt_SUPPORTED
1243PNG_EXTERN void png_handle_tEXt PNGARG((png_structp png_ptr, png_infop info_ptr,
1244    png_uint_32 length));
1245#endif
1246
1247#ifdef PNG_READ_tIME_SUPPORTED
1248PNG_EXTERN void png_handle_tIME PNGARG((png_structp png_ptr, png_infop info_ptr,
1249    png_uint_32 length));
1250#endif
1251
1252#ifdef PNG_READ_tRNS_SUPPORTED
1253PNG_EXTERN void png_handle_tRNS PNGARG((png_structp png_ptr, png_infop info_ptr,
1254    png_uint_32 length));
1255#endif
1256
1257#ifdef PNG_READ_zTXt_SUPPORTED
1258PNG_EXTERN void png_handle_zTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
1259    png_uint_32 length));
1260#endif
1261
1262PNG_EXTERN void png_handle_unknown PNGARG((png_structp png_ptr,
1263    png_infop info_ptr, png_uint_32 length));
1264
1265PNG_EXTERN void png_check_chunk_name PNGARG((png_structp png_ptr,
1266    png_uint_32 chunk_name));
1267
1268#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
1269/* Exactly as png_handle_as_unknown() except that the argument is a 32-bit chunk
1270 * name, not a string.
1271 */
1272PNG_EXTERN int png_chunk_unknown_handling PNGARG((png_structp png_ptr,
1273    png_uint_32 chunk_name));
1274#endif
1275
1276/* Handle the transformations for reading and writing */
1277#ifdef PNG_READ_TRANSFORMS_SUPPORTED
1278PNG_EXTERN void png_do_read_transformations PNGARG((png_structp png_ptr,
1279   png_row_infop row_info));
1280#endif
1281#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
1282PNG_EXTERN void png_do_write_transformations PNGARG((png_structp png_ptr,
1283   png_row_infop row_info));
1284#endif
1285
1286#ifdef PNG_READ_TRANSFORMS_SUPPORTED
1287PNG_EXTERN void png_init_read_transformations PNGARG((png_structp png_ptr));
1288#endif
1289
1290#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1291PNG_EXTERN void png_push_read_chunk PNGARG((png_structp png_ptr,
1292    png_infop info_ptr));
1293PNG_EXTERN void png_push_read_sig PNGARG((png_structp png_ptr,
1294    png_infop info_ptr));
1295PNG_EXTERN void png_push_check_crc PNGARG((png_structp png_ptr));
1296PNG_EXTERN void png_push_crc_skip PNGARG((png_structp png_ptr,
1297    png_uint_32 length));
1298PNG_EXTERN void png_push_crc_finish PNGARG((png_structp png_ptr));
1299PNG_EXTERN void png_push_save_buffer PNGARG((png_structp png_ptr));
1300PNG_EXTERN void png_push_restore_buffer PNGARG((png_structp png_ptr,
1301    png_bytep buffer, png_size_t buffer_length));
1302PNG_EXTERN void png_push_read_IDAT PNGARG((png_structp png_ptr));
1303PNG_EXTERN void png_process_IDAT_data PNGARG((png_structp png_ptr,
1304    png_bytep buffer, png_size_t buffer_length));
1305PNG_EXTERN void png_push_process_row PNGARG((png_structp png_ptr));
1306PNG_EXTERN void png_push_handle_unknown PNGARG((png_structp png_ptr,
1307   png_infop info_ptr, png_uint_32 length));
1308PNG_EXTERN void png_push_have_info PNGARG((png_structp png_ptr,
1309   png_infop info_ptr));
1310PNG_EXTERN void png_push_have_end PNGARG((png_structp png_ptr,
1311   png_infop info_ptr));
1312PNG_EXTERN void png_push_have_row PNGARG((png_structp png_ptr, png_bytep row));
1313PNG_EXTERN void png_push_read_end PNGARG((png_structp png_ptr,
1314    png_infop info_ptr));
1315PNG_EXTERN void png_process_some_data PNGARG((png_structp png_ptr,
1316    png_infop info_ptr));
1317PNG_EXTERN void png_read_push_finish_row PNGARG((png_structp png_ptr));
1318#  ifdef PNG_READ_tEXt_SUPPORTED
1319PNG_EXTERN void png_push_handle_tEXt PNGARG((png_structp png_ptr,
1320    png_infop info_ptr, png_uint_32 length));
1321PNG_EXTERN void png_push_read_tEXt PNGARG((png_structp png_ptr,
1322    png_infop info_ptr));
1323#  endif
1324#  ifdef PNG_READ_zTXt_SUPPORTED
1325PNG_EXTERN void png_push_handle_zTXt PNGARG((png_structp png_ptr,
1326    png_infop info_ptr, png_uint_32 length));
1327PNG_EXTERN void png_push_read_zTXt PNGARG((png_structp png_ptr,
1328    png_infop info_ptr));
1329#  endif
1330#  ifdef PNG_READ_iTXt_SUPPORTED
1331PNG_EXTERN void png_push_handle_iTXt PNGARG((png_structp png_ptr,
1332    png_infop info_ptr, png_uint_32 length));
1333PNG_EXTERN void png_push_read_iTXt PNGARG((png_structp png_ptr,
1334    png_infop info_ptr));
1335#  endif
1336
1337#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
1338
1339#ifdef PNG_MNG_FEATURES_SUPPORTED
1340PNG_EXTERN void png_do_read_intrapixel PNGARG((png_row_infop row_info,
1341    png_bytep row));
1342PNG_EXTERN void png_do_write_intrapixel PNGARG((png_row_infop row_info,
1343    png_bytep row));
1344#endif
1345
1346/* Added at libpng version 1.4.0 */
1347#ifdef PNG_CHECK_cHRM_SUPPORTED
1348PNG_EXTERN int png_check_cHRM_fixed PNGARG((png_structp png_ptr,
1349    png_fixed_point int_white_x, png_fixed_point int_white_y,
1350    png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
1351    int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
1352    png_fixed_point int_blue_y));
1353#endif
1354
1355#ifdef PNG_CHECK_cHRM_SUPPORTED
1356/* Added at libpng version 1.2.34 and 1.4.0 */
1357/* Currently only used by png_check_cHRM_fixed */
1358PNG_EXTERN void png_64bit_product PNGARG((long v1, long v2,
1359    unsigned long *hi_product, unsigned long *lo_product));
1360#endif
1361
1362#ifdef PNG_cHRM_SUPPORTED
1363/* Added at libpng version 1.5.5 */
1364typedef struct png_xy
1365{
1366   png_fixed_point redx, redy;
1367   png_fixed_point greenx, greeny;
1368   png_fixed_point bluex, bluey;
1369   png_fixed_point whitex, whitey;
1370} png_xy;
1371
1372typedef struct png_XYZ
1373{
1374   png_fixed_point redX, redY, redZ;
1375   png_fixed_point greenX, greenY, greenZ;
1376   png_fixed_point blueX, blueY, blueZ;
1377} png_XYZ;
1378
1379/* The conversion APIs return 0 on success, non-zero on a parameter error. They
1380 * allow conversion between the above representations of a color encoding.  When
1381 * converting from XYZ end points to chromaticities the absolute magnitude of
1382 * the end points is lost, when converting back the sum of the Y values of the
1383 * three end points will be 1.0
1384 */
1385PNG_EXTERN int png_xy_from_XYZ PNGARG((png_xy *xy, png_XYZ XYZ));
1386PNG_EXTERN int png_XYZ_from_xy PNGARG((png_XYZ *XYZ, png_xy xy));
1387PNG_EXTERN int png_XYZ_from_xy_checked PNGARG((png_structp png_ptr,
1388   png_XYZ *XYZ, png_xy xy));
1389#endif
1390
1391/* Added at libpng version 1.4.0 */
1392PNG_EXTERN void png_check_IHDR PNGARG((png_structp png_ptr,
1393    png_uint_32 width, png_uint_32 height, int bit_depth,
1394    int color_type, int interlace_type, int compression_type,
1395    int filter_type));
1396
1397/* Added at libpng version 1.5.10 */
1398#if defined(PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED) || \
1399    defined(PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED)
1400PNG_EXTERN void png_do_check_palette_indexes PNGARG((png_structp png_ptr,
1401    png_row_infop row_info));
1402#endif
1403
1404/* Free all memory used by the read (old method - NOT DLL EXPORTED) */
1405PNG_EXTERN void png_read_destroy PNGARG((png_structp png_ptr,
1406    png_infop info_ptr, png_infop end_info_ptr));
1407
1408/* Free any memory used in png_ptr struct (old method - NOT DLL EXPORTED) */
1409PNG_EXTERN void png_write_destroy PNGARG((png_structp png_ptr));
1410
1411#ifdef USE_FAR_KEYWORD  /* memory model conversion function */
1412PNG_EXTERN void *png_far_to_near PNGARG((png_structp png_ptr, png_voidp ptr,
1413    int check));
1414#endif /* USE_FAR_KEYWORD */
1415
1416#if defined(PNG_FLOATING_POINT_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED)
1417PNG_EXTERN PNG_FUNCTION(void, png_fixed_error, (png_structp png_ptr,
1418   png_const_charp name),PNG_NORETURN);
1419#endif
1420
1421/* Puts 'string' into 'buffer' at buffer[pos], taking care never to overwrite
1422 * the end.  Always leaves the buffer nul terminated.  Never errors out (and
1423 * there is no error code.)
1424 */
1425PNG_EXTERN size_t png_safecat(png_charp buffer, size_t bufsize, size_t pos,
1426    png_const_charp string);
1427
1428/* Various internal functions to handle formatted warning messages, currently
1429 * only implemented for warnings.
1430 */
1431#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_SUPPORTED)
1432/* Utility to dump an unsigned value into a buffer, given a start pointer and
1433 * and end pointer (which should point just *beyond* the end of the buffer!)
1434 * Returns the pointer to the start of the formatted string.  This utility only
1435 * does unsigned values.
1436 */
1437PNG_EXTERN png_charp png_format_number(png_const_charp start, png_charp end,
1438   int format, png_alloc_size_t number);
1439
1440/* Convenience macro that takes an array: */
1441#define PNG_FORMAT_NUMBER(buffer,format,number) \
1442   png_format_number(buffer, buffer + (sizeof buffer), format, number)
1443
1444/* Suggested size for a number buffer (enough for 64 bits and a sign!) */
1445#define PNG_NUMBER_BUFFER_SIZE 24
1446
1447/* These are the integer formats currently supported, the name is formed from
1448 * the standard printf(3) format string.
1449 */
1450#define PNG_NUMBER_FORMAT_u     1 /* chose unsigned API! */
1451#define PNG_NUMBER_FORMAT_02u   2
1452#define PNG_NUMBER_FORMAT_d     1 /* chose signed API! */
1453#define PNG_NUMBER_FORMAT_02d   2
1454#define PNG_NUMBER_FORMAT_x     3
1455#define PNG_NUMBER_FORMAT_02x   4
1456#define PNG_NUMBER_FORMAT_fixed 5 /* choose the signed API */
1457#endif
1458
1459#ifdef PNG_WARNINGS_SUPPORTED
1460/* New defines and members adding in libpng-1.5.4 */
1461#  define PNG_WARNING_PARAMETER_SIZE 32
1462#  define PNG_WARNING_PARAMETER_COUNT 8
1463
1464/* An l-value of this type has to be passed to the APIs below to cache the
1465 * values of the parameters to a formatted warning message.
1466 */
1467typedef char png_warning_parameters[PNG_WARNING_PARAMETER_COUNT][
1468   PNG_WARNING_PARAMETER_SIZE];
1469
1470PNG_EXTERN void png_warning_parameter(png_warning_parameters p, int number,
1471    png_const_charp string);
1472    /* Parameters are limited in size to PNG_WARNING_PARAMETER_SIZE characters,
1473     * including the trailing '\0'.
1474     */
1475PNG_EXTERN void png_warning_parameter_unsigned(png_warning_parameters p,
1476    int number, int format, png_alloc_size_t value);
1477    /* Use png_alloc_size_t because it is an unsigned type as big as any we
1478     * need to output.  Use the following for a signed value.
1479     */
1480PNG_EXTERN void png_warning_parameter_signed(png_warning_parameters p,
1481    int number, int format, png_int_32 value);
1482
1483PNG_EXTERN void png_formatted_warning(png_structp png_ptr,
1484    png_warning_parameters p, png_const_charp message);
1485    /* 'message' follows the X/Open approach of using @1, @2 to insert
1486     * parameters previously supplied using the above functions.  Errors in
1487     * specifying the paramters will simple result in garbage substitutions.
1488     */
1489#endif
1490
1491/* ASCII to FP interfaces, currently only implemented if sCAL
1492 * support is required.
1493 */
1494#if defined(PNG_READ_sCAL_SUPPORTED)
1495/* MAX_DIGITS is actually the maximum number of characters in an sCAL
1496 * width or height, derived from the precision (number of significant
1497 * digits - a build time settable option) and assumpitions about the
1498 * maximum ridiculous exponent.
1499 */
1500#define PNG_sCAL_MAX_DIGITS (PNG_sCAL_PRECISION+1/*.*/+1/*E*/+10/*exponent*/)
1501
1502#ifdef PNG_FLOATING_POINT_SUPPORTED
1503PNG_EXTERN void png_ascii_from_fp PNGARG((png_structp png_ptr, png_charp ascii,
1504    png_size_t size, double fp, unsigned int precision));
1505#endif /* FLOATING_POINT */
1506
1507#ifdef PNG_FIXED_POINT_SUPPORTED
1508PNG_EXTERN void png_ascii_from_fixed PNGARG((png_structp png_ptr,
1509    png_charp ascii, png_size_t size, png_fixed_point fp));
1510#endif /* FIXED_POINT */
1511#endif /* READ_sCAL */
1512
1513#if defined(PNG_sCAL_SUPPORTED) || defined(PNG_pCAL_SUPPORTED)
1514/* An internal API to validate the format of a floating point number.
1515 * The result is the index of the next character.  If the number is
1516 * not valid it will be the index of a character in the supposed number.
1517 *
1518 * The format of a number is defined in the PNG extensions specification
1519 * and this API is strictly conformant to that spec, not anyone elses!
1520 *
1521 * The format as a regular expression is:
1522 *
1523 * [+-]?[0-9]+.?([Ee][+-]?[0-9]+)?
1524 *
1525 * or:
1526 *
1527 * [+-]?.[0-9]+(.[0-9]+)?([Ee][+-]?[0-9]+)?
1528 *
1529 * The complexity is that either integer or fraction must be present and the
1530 * fraction is permitted to have no digits only if the integer is present.
1531 *
1532 * NOTE: The dangling E problem.
1533 *   There is a PNG valid floating point number in the following:
1534 *
1535 *       PNG floating point numb1.ers are not greedy.
1536 *
1537 *   Working this out requires *TWO* character lookahead (because of the
1538 *   sign), the parser does not do this - it will fail at the 'r' - this
1539 *   doesn't matter for PNG sCAL chunk values, but it requires more care
1540 *   if the value were ever to be embedded in something more complex.  Use
1541 *   ANSI-C strtod if you need the lookahead.
1542 */
1543/* State table for the parser. */
1544#define PNG_FP_INTEGER    0  /* before or in integer */
1545#define PNG_FP_FRACTION   1  /* before or in fraction */
1546#define PNG_FP_EXPONENT   2  /* before or in exponent */
1547#define PNG_FP_STATE      3  /* mask for the above */
1548#define PNG_FP_SAW_SIGN   4  /* Saw +/- in current state */
1549#define PNG_FP_SAW_DIGIT  8  /* Saw a digit in current state */
1550#define PNG_FP_SAW_DOT   16  /* Saw a dot in current state */
1551#define PNG_FP_SAW_E     32  /* Saw an E (or e) in current state */
1552#define PNG_FP_SAW_ANY   60  /* Saw any of the above 4 */
1553
1554/* These three values don't affect the parser.  They are set but not used.
1555 */
1556#define PNG_FP_WAS_VALID 64  /* Preceding substring is a valid fp number */
1557#define PNG_FP_NEGATIVE 128  /* A negative number, including "-0" */
1558#define PNG_FP_NONZERO  256  /* A non-zero value */
1559#define PNG_FP_STICKY   448  /* The above three flags */
1560
1561/* This is available for the caller to store in 'state' if required.  Do not
1562 * call the parser after setting it (the parser sometimes clears it.)
1563 */
1564#define PNG_FP_INVALID  512  /* Available for callers as a distinct value */
1565
1566/* Result codes for the parser (boolean - true meants ok, false means
1567 * not ok yet.)
1568 */
1569#define PNG_FP_MAYBE      0  /* The number may be valid in the future */
1570#define PNG_FP_OK         1  /* The number is valid */
1571
1572/* Tests on the sticky non-zero and negative flags.  To pass these checks
1573 * the state must also indicate that the whole number is valid - this is
1574 * achieved by testing PNG_FP_SAW_DIGIT (see the implementation for why this
1575 * is equivalent to PNG_FP_OK above.)
1576 */
1577#define PNG_FP_NZ_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NEGATIVE | PNG_FP_NONZERO)
1578   /* NZ_MASK: the string is valid and a non-zero negative value */
1579#define PNG_FP_Z_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NONZERO)
1580   /* Z MASK: the string is valid and a non-zero value. */
1581   /* PNG_FP_SAW_DIGIT: the string is valid. */
1582#define PNG_FP_IS_ZERO(state) (((state) & PNG_FP_Z_MASK) == PNG_FP_SAW_DIGIT)
1583#define PNG_FP_IS_POSITIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_Z_MASK)
1584#define PNG_FP_IS_NEGATIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_NZ_MASK)
1585 
1586/* The actual parser.  This can be called repeatedly, it updates
1587 * the index into the string and the state variable (which must
1588 * be initialzed to 0).  It returns a result code, as above.  There
1589 * is no point calling the parser any more if it fails to advance to
1590 * the end of the string - it is stuck on an invalid character (or
1591 * terminated by '\0').
1592 *
1593 * Note that the pointer will consume an E or even an E+ then leave
1594 * a 'maybe' state even though a preceding integer.fraction is valid.
1595 * The PNG_FP_WAS_VALID flag indicates that a preceding substring was
1596 * a valid number.  It's possible to recover from this by calling
1597 * the parser again (from the start, with state 0) but with a string
1598 * that omits the last character (i.e. set the size to the index of
1599 * the problem character.)  This has not been tested within libpng.
1600 */
1601PNG_EXTERN int png_check_fp_number PNGARG((png_const_charp string,
1602    png_size_t size, int *statep, png_size_tp whereami));
1603
1604/* This is the same but it checks a complete string and returns true
1605 * only if it just contains a floating point number.  As of 1.5.4 this
1606 * function also returns the state at the end of parsing the number if
1607 * it was valid (otherwise it returns 0.)  This can be used for testing
1608 * for negative or zero values using the sticky flag.
1609 */
1610PNG_EXTERN int png_check_fp_string PNGARG((png_const_charp string,
1611    png_size_t size));
1612#endif /* pCAL || sCAL */
1613
1614#if defined(PNG_READ_GAMMA_SUPPORTED) ||\
1615    defined(PNG_INCH_CONVERSIONS_SUPPORTED) || defined(PNG_READ_pHYs_SUPPORTED)
1616/* Added at libpng version 1.5.0 */
1617/* This is a utility to provide a*times/div (rounded) and indicate
1618 * if there is an overflow.  The result is a boolean - false (0)
1619 * for overflow, true (1) if no overflow, in which case *res
1620 * holds the result.
1621 */
1622PNG_EXTERN int png_muldiv PNGARG((png_fixed_point_p res, png_fixed_point a,
1623    png_int_32 multiplied_by, png_int_32 divided_by));
1624#endif
1625
1626#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_INCH_CONVERSIONS_SUPPORTED)
1627/* Same deal, but issue a warning on overflow and return 0. */
1628PNG_EXTERN png_fixed_point png_muldiv_warn PNGARG((png_structp png_ptr,
1629    png_fixed_point a, png_int_32 multiplied_by, png_int_32 divided_by));
1630#endif
1631
1632#ifdef PNG_READ_GAMMA_SUPPORTED
1633/* Calculate a reciprocal - used for gamma values.  This returns
1634 * 0 if the argument is 0 in order to maintain an undefined value,
1635 * there are no warnings.
1636 */
1637PNG_EXTERN png_fixed_point png_reciprocal PNGARG((png_fixed_point a));
1638
1639/* The same but gives a reciprocal of the product of two fixed point
1640 * values.  Accuracy is suitable for gamma calculations but this is
1641 * not exact - use png_muldiv for that.
1642 */
1643PNG_EXTERN png_fixed_point png_reciprocal2 PNGARG((png_fixed_point a,
1644    png_fixed_point b));
1645#endif
1646
1647#ifdef PNG_READ_GAMMA_SUPPORTED
1648/* Internal fixed point gamma correction.  These APIs are called as
1649 * required to convert single values - they don't need to be fast,
1650 * they are not used when processing image pixel values.
1651 *
1652 * While the input is an 'unsigned' value it must actually be the
1653 * correct bit value - 0..255 or 0..65535 as required.
1654 */
1655PNG_EXTERN png_uint_16 png_gamma_correct PNGARG((png_structp png_ptr,
1656    unsigned int value, png_fixed_point gamma_value));
1657PNG_EXTERN int png_gamma_significant PNGARG((png_fixed_point gamma_value));
1658PNG_EXTERN png_uint_16 png_gamma_16bit_correct PNGARG((unsigned int value,
1659    png_fixed_point gamma_value));
1660PNG_EXTERN png_byte png_gamma_8bit_correct PNGARG((unsigned int value,
1661    png_fixed_point gamma_value));
1662PNG_EXTERN void png_destroy_gamma_table(png_structp png_ptr);
1663PNG_EXTERN void png_build_gamma_table PNGARG((png_structp png_ptr,
1664    int bit_depth));
1665#endif
1666
1667/* Maintainer: Put new private prototypes here ^ and in libpngpf.3 */
1668
1669#include "pngdebug.h"
1670
1671#ifdef __cplusplus
1672}
1673#endif
1674
1675#endif /* PNGPRIV_H */
Note: See TracBrowser for help on using the repository browser.