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) 1998-2014 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 1.6.10 [March 6, 2014]
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 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#ifndef PNG_VERSION_INFO_ONLY
43/* Standard library headers not required by png.h: */
44#  include <stdlib.h>
45#  include <string.h>
46#endif
47
48#define PNGLIB_BUILD /*libpng is being built, not used*/
49
50/* If HAVE_CONFIG_H is defined during the build then the build system must
51 * provide an appropriate "config.h" file on the include path.  The header file
52 * must provide definitions as required below (search for "HAVE_CONFIG_H");
53 * see configure.ac for more details of the requirements.  The macro
54 * "PNG_NO_CONFIG_H" is provided for maintainers to test for dependencies on
55 * 'configure'; define this macro to prevent the configure build including the
56 * configure generated config.h.  Libpng is expected to compile without *any*
57 * special build system support on a reasonably ANSI-C compliant system.
58 */
59#if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H)
60#  include <config.h>
61
62   /* Pick up the definition of 'restrict' from config.h if it was read: */
63#  define PNG_RESTRICT restrict
64#endif
65
66/* To support symbol prefixing it is necessary to know *before* including png.h
67 * whether the fixed point (and maybe other) APIs are exported, because if they
68 * are not internal definitions may be required.  This is handled below just
69 * before png.h is included, but load the configuration now if it is available.
70 */
71#ifndef PNGLCONF_H
72#  include "pnglibconf.h"
73#endif
74
75/* Local renames may change non-exported API functions from png.h */
76#if defined(PNG_PREFIX) && !defined(PNGPREFIX_H)
77#  include "pngprefix.h"
78#endif
79
80#ifdef PNG_USER_CONFIG
81#  include "pngusr.h"
82   /* These should have been defined in pngusr.h */
83#  ifndef PNG_USER_PRIVATEBUILD
84#    define PNG_USER_PRIVATEBUILD "Custom libpng build"
85#  endif
86#  ifndef PNG_USER_DLLFNAME_POSTFIX
87#    define PNG_USER_DLLFNAME_POSTFIX "Cb"
88#  endif
89#endif
90
91/* Compile time options.
92 * =====================
93 * In a multi-arch build the compiler may compile the code several times for the
94 * same object module, producing different binaries for different architectures.
95 * When this happens configure-time setting of the target host options cannot be
96 * done and this interferes with the handling of the ARM NEON optimizations, and
97 * possibly other similar optimizations.  Put additional tests here; in general
98 * this is needed when the same option can be changed at both compile time and
99 * run time depending on the target OS (i.e. iOS vs Android.)
100 *
101 * NOTE: symbol prefixing does not pass $(CFLAGS) to the preprocessor, because
102 * this is not possible with certain compilers (Oracle SUN OS CC), as a result
103 * it is necessary to ensure that all extern functions that *might* be used
104 * regardless of $(CFLAGS) get declared in this file.  The test on __ARM_NEON__
105 * below is one example of this behavior because it is controlled by the
106 * presence or not of -mfpu=neon on the GCC command line, it is possible to do
107 * this in $(CC), e.g. "CC=gcc -mfpu=neon", but people who build libpng rarely
108 * do this.
109 */
110#ifndef PNG_ARM_NEON_OPT
111   /* ARM NEON optimizations are being controlled by the compiler settings,
112    * typically the target FPU.  If the FPU has been set to NEON (-mfpu=neon
113    * with GCC) then the compiler will define __ARM_NEON__ and we can rely
114    * unconditionally on NEON instructions not crashing, otherwise we must
115    * disable use of NEON instructions.
116    *
117    * NOTE: at present these optimizations depend on 'ALIGNED_MEMORY', so they
118    * can only be turned on automatically if that is supported too.  If
119    * PNG_ARM_NEON_OPT is set in CPPFLAGS (to >0) then arm/arm_init.c will fail
120    * to compile with an appropriate #error if ALIGNED_MEMORY has been turned
121    * off.
122    *
123    * Note that gcc-4.9 defines __ARM_NEON instead of __ARM_NEON__, so we
124    * check both variants.
125    */
126#  if (defined(__ARM_NEON__) || defined(__ARM_NEON)) && \
127   defined(PNG_ALIGNED_MEMORY_SUPPORTED)
128#     define PNG_ARM_NEON_OPT 2
129#  else
130#     define PNG_ARM_NEON_OPT 0
131#  endif
132#endif
133
134#if PNG_ARM_NEON_OPT > 0
135   /* NEON optimizations are to be at least considered by libpng, so enable the
136    * callbacks to do this.
137    */
138#  define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_neon
139
140   /* By default the 'intrinsics' code in arm/filter_neon_intrinsics.c is used
141    * if possible - if __ARM_NEON__ is set and the compiler version is not known
142    * to be broken.  This is controlled by PNG_ARM_NEON_IMPLEMENTATION which can
143    * be:
144    *
145    *    1  The intrinsics code (the default with __ARM_NEON__)
146    *    2  The hand coded assembler (the default without __ARM_NEON__)
147    *
148    * It is possible to set PNG_ARM_NEON_IMPLEMENTATION in CPPFLAGS, however
149    * this is *NOT* supported and may cease to work even after a minor revision
150    * to libpng.  It *is* valid to do this for testing purposes, e.g. speed
151    * testing or a new compiler, but the results should be communicated to the
152    * libpng implementation list for incorporation in the next minor release.
153    */
154#  ifndef PNG_ARM_NEON_IMPLEMENTATION
155#     if defined(__ARM_NEON__) || defined(__ARM_NEON)
156#        if defined(__clang__)
157            /* At present it is unknown by the libpng developers which versions
158             * of clang support the intrinsics, however some or perhaps all
159             * versions do not work with the assembler so this may be
160             * irrelevant, so just use the default (do nothing here.)
161             */
162#        elif defined(__GNUC__)
163            /* GCC 4.5.4 NEON support is known to be broken.  4.6.3 is known to
164             * work, so if this *is* GCC, or G++, look for a version >4.5
165             */
166#           if __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 6)
167#              define PNG_ARM_NEON_IMPLEMENTATION 2
168#           endif /* no GNUC support */
169#        endif /* __GNUC__ */
170#     else /* !defined __ARM_NEON__ */
171         /* The 'intrinsics' code simply won't compile without this -mfpu=neon:
172          */
173#        define PNG_ARM_NEON_IMPLEMENTATION 2
174#     endif /* __ARM_NEON__ */
175#  endif /* !defined PNG_ARM_NEON_IMPLEMENTATION */
176
177#  ifndef PNG_ARM_NEON_IMPLEMENTATION
178      /* Use the intrinsics code by default. */
179#     define PNG_ARM_NEON_IMPLEMENTATION 1
180#  endif
181#endif /* PNG_ARM_NEON_OPT > 0 */
182
183/* Is this a build of a DLL where compilation of the object modules requires
184 * different preprocessor settings to those required for a simple library?  If
185 * so PNG_BUILD_DLL must be set.
186 *
187 * If libpng is used inside a DLL but that DLL does not export the libpng APIs
188 * PNG_BUILD_DLL must not be set.  To avoid the code below kicking in build a
189 * static library of libpng then link the DLL against that.
190 */
191#ifndef PNG_BUILD_DLL
192#  ifdef DLL_EXPORT
193      /* This is set by libtool when files are compiled for a DLL; libtool
194       * always compiles twice, even on systems where it isn't necessary.  Set
195       * PNG_BUILD_DLL in case it is necessary:
196       */
197#     define PNG_BUILD_DLL
198#  else
199#     ifdef _WINDLL
200         /* This is set by the Microsoft Visual Studio IDE in projects that
201          * build a DLL.  It can't easily be removed from those projects (it
202          * isn't visible in the Visual Studio UI) so it is a fairly reliable
203          * indication that PNG_IMPEXP needs to be set to the DLL export
204          * attributes.
205          */
206#        define PNG_BUILD_DLL
207#     else
208#        ifdef __DLL__
209            /* This is set by the Borland C system when compiling for a DLL
210             * (as above.)
211             */
212#           define PNG_BUILD_DLL
213#        else
214            /* Add additional compiler cases here. */
215#        endif
216#     endif
217#  endif
218#endif /* Setting PNG_BUILD_DLL if required */
219
220/* See pngconf.h for more details: the builder of the library may set this on
221 * the command line to the right thing for the specific compilation system or it
222 * may be automagically set above (at present we know of no system where it does
223 * need to be set on the command line.)
224 *
225 * PNG_IMPEXP must be set here when building the library to prevent pngconf.h
226 * setting it to the "import" setting for a DLL build.
227 */
228#ifndef PNG_IMPEXP
229#  ifdef PNG_BUILD_DLL
230#     define PNG_IMPEXP PNG_DLL_EXPORT
231#  else
232      /* Not building a DLL, or the DLL doesn't require specific export
233       * definitions.
234       */
235#     define PNG_IMPEXP
236#  endif
237#endif
238
239/* No warnings for private or deprecated functions in the build: */
240#ifndef PNG_DEPRECATED
241#  define PNG_DEPRECATED
242#endif
243#ifndef PNG_PRIVATE
244#  define PNG_PRIVATE
245#endif
246
247/* Symbol preprocessing support.
248 *
249 * To enable listing global, but internal, symbols the following macros should
250 * always be used to declare an extern data or function object in this file.
251 */
252#ifndef PNG_INTERNAL_DATA
253#  define PNG_INTERNAL_DATA(type, name, array) extern type name array
254#endif
255
256#ifndef PNG_INTERNAL_FUNCTION
257#  define PNG_INTERNAL_FUNCTION(type, name, args, attributes)\
258      extern PNG_FUNCTION(type, name, args, PNG_EMPTY attributes)
259#endif
260
261#ifndef PNG_INTERNAL_CALLBACK
262#  define PNG_INTERNAL_CALLBACK(type, name, args, attributes)\
263      extern PNG_FUNCTION(type, (PNGCBAPI name), args, PNG_EMPTY attributes)
264#endif
265
266/* If floating or fixed point APIs are disabled they may still be compiled
267 * internally.  To handle this make sure they are declared as the appropriate
268 * internal extern function (otherwise the symbol prefixing stuff won't work and
269 * the functions will be used without definitions.)
270 *
271 * NOTE: although all the API functions are declared here they are not all
272 * actually built!  Because the declarations are still made it is necessary to
273 * fake out types that they depend on.
274 */
275#ifndef PNG_FP_EXPORT
276#  ifndef PNG_FLOATING_POINT_SUPPORTED
277#     define PNG_FP_EXPORT(ordinal, type, name, args)\
278         PNG_INTERNAL_FUNCTION(type, name, args, PNG_EMPTY);
279#     ifndef PNG_VERSION_INFO_ONLY
280         typedef struct png_incomplete png_double;
281         typedef png_double*           png_doublep;
282         typedef const png_double*     png_const_doublep;
283         typedef png_double**          png_doublepp;
284#     endif
285#  endif
286#endif
287#ifndef PNG_FIXED_EXPORT
288#  ifndef PNG_FIXED_POINT_SUPPORTED
289#     define PNG_FIXED_EXPORT(ordinal, type, name, args)\
290         PNG_INTERNAL_FUNCTION(type, name, args, PNG_EMPTY);
291#  endif
292#endif
293
294#include "png.h"
295
296/* pngconf.h does not set PNG_DLL_EXPORT unless it is required, so: */
297#ifndef PNG_DLL_EXPORT
298#  define PNG_DLL_EXPORT
299#endif
300
301/* SECURITY and SAFETY:
302 *
303 * By default libpng is built without any internal limits on image size,
304 * individual heap (png_malloc) allocations or the total amount of memory used.
305 * If PNG_SAFE_LIMITS_SUPPORTED is defined, however, the limits below are used
306 * (unless individually overridden).  These limits are believed to be fairly
307 * safe, but builders of secure systems should verify the values against the
308 * real system capabilities.
309 */
310#ifdef PNG_SAFE_LIMITS_SUPPORTED
311   /* 'safe' limits */
312#  ifndef PNG_USER_WIDTH_MAX
313#     define PNG_USER_WIDTH_MAX 1000000
314#  endif
315#  ifndef PNG_USER_HEIGHT_MAX
316#     define PNG_USER_HEIGHT_MAX 1000000
317#  endif
318#  ifndef PNG_USER_CHUNK_CACHE_MAX
319#     define PNG_USER_CHUNK_CACHE_MAX 128
320#  endif
321#  ifndef PNG_USER_CHUNK_MALLOC_MAX
322#     define PNG_USER_CHUNK_MALLOC_MAX 8000000
323#  endif
324#else
325   /* values for no limits */
326#  ifndef PNG_USER_WIDTH_MAX
327#     define PNG_USER_WIDTH_MAX 0x7fffffff
328#  endif
329#  ifndef PNG_USER_HEIGHT_MAX
330#     define PNG_USER_HEIGHT_MAX 0x7fffffff
331#  endif
332#  ifndef PNG_USER_CHUNK_CACHE_MAX
333#     define PNG_USER_CHUNK_CACHE_MAX 0
334#  endif
335#  ifndef PNG_USER_CHUNK_MALLOC_MAX
336#     define PNG_USER_CHUNK_MALLOC_MAX 0
337#  endif
338#endif
339
340/* Moved to pngpriv.h at libpng-1.5.0 */
341/* NOTE: some of these may have been used in external applications as
342 * these definitions were exposed in pngconf.h prior to 1.5.
343 */
344
345/* If you are running on a machine where you cannot allocate more
346 * than 64K of memory at once, uncomment this.  While libpng will not
347 * normally need that much memory in a chunk (unless you load up a very
348 * large file), zlib needs to know how big of a chunk it can use, and
349 * libpng thus makes sure to check any memory allocation to verify it
350 * will fit into memory.
351 *
352 * zlib provides 'MAXSEG_64K' which, if defined, indicates the
353 * same limit and pngconf.h (already included) sets the limit
354 * if certain operating systems are detected.
355 */
356#if defined(MAXSEG_64K) && !defined(PNG_MAX_MALLOC_64K)
357#  define PNG_MAX_MALLOC_64K
358#endif
359
360#ifndef PNG_UNUSED
361/* Unused formal parameter warnings are silenced using the following macro
362 * which is expected to have no bad effects on performance (optimizing
363 * compilers will probably remove it entirely).  Note that if you replace
364 * it with something other than whitespace, you must include the terminating
365 * semicolon.
366 */
367#  define PNG_UNUSED(param) (void)param;
368#endif
369
370/* Just a little check that someone hasn't tried to define something
371 * contradictory.
372 */
373#if (PNG_ZBUF_SIZE > 65536L) && defined(PNG_MAX_MALLOC_64K)
374#  undef PNG_ZBUF_SIZE
375#  define PNG_ZBUF_SIZE 65536L
376#endif
377
378/* If warnings or errors are turned off the code is disabled or redirected here.
379 * From 1.5.4 functions have been added to allow very limited formatting of
380 * error and warning messages - this code will also be disabled here.
381 */
382#ifdef PNG_WARNINGS_SUPPORTED
383#  define PNG_WARNING_PARAMETERS(p) png_warning_parameters p;
384#else
385#  define png_warning_parameter(p,number,string) ((void)0)
386#  define png_warning_parameter_unsigned(p,number,format,value) ((void)0)
387#  define png_warning_parameter_signed(p,number,format,value) ((void)0)
388#  define png_formatted_warning(pp,p,message) ((void)(pp))
389#  define PNG_WARNING_PARAMETERS(p)
390#endif
391#ifndef PNG_ERROR_TEXT_SUPPORTED
392#  define png_fixed_error(s1,s2) png_err(s1)
393#endif
394
395/* C allows up-casts from (void*) to any pointer and (const void*) to any
396 * pointer to a const object.  C++ regards this as a type error and requires an
397 * explicit, static, cast and provides the static_cast<> rune to ensure that
398 * const is not cast away.
399 */
400#ifdef __cplusplus
401#  define png_voidcast(type, value) static_cast<type>(value)
402#  define png_constcast(type, value) const_cast<type>(value)
403#  define png_aligncast(type, value) \
404   static_cast<type>(static_cast<void*>(value))
405#  define png_aligncastconst(type, value) \
406   static_cast<type>(static_cast<const void*>(value))
407#else
408#  define png_voidcast(type, value) (value)
409#  define png_constcast(type, value) ((type)(value))
410#  define png_aligncast(type, value) ((void*)(value))
411#  define png_aligncastconst(type, value) ((const void*)(value))
412#endif /* __cplusplus */
413
414/* Some fixed point APIs are still required even if not exported because
415 * they get used by the corresponding floating point APIs.  This magic
416 * deals with this:
417 */
418#ifdef PNG_FIXED_POINT_SUPPORTED
419#  define PNGFAPI PNGAPI
420#else
421#  define PNGFAPI /* PRIVATE */
422#endif
423
424#ifndef PNG_VERSION_INFO_ONLY
425/* Other defines specific to compilers can go here.  Try to keep
426 * them inside an appropriate ifdef/endif pair for portability.
427 */
428#if defined(PNG_FLOATING_POINT_SUPPORTED) ||\
429    defined(PNG_FLOATING_ARITHMETIC_SUPPORTED)
430   /* png.c requires the following ANSI-C constants if the conversion of
431    * floating point to ASCII is implemented therein:
432    *
433    *  DBL_DIG  Maximum number of decimal digits (can be set to any constant)
434    *  DBL_MIN  Smallest normalized fp number (can be set to an arbitrary value)
435    *  DBL_MAX  Maximum floating point number (can be set to an arbitrary value)
436    */
437#  include <float.h>
438
439#  if (defined(__MWERKS__) && defined(macintosh)) || defined(applec) || \
440    defined(THINK_C) || defined(__SC__) || defined(TARGET_OS_MAC)
441     /* We need to check that <math.h> hasn't already been included earlier
442      * as it seems it doesn't agree with <fp.h>, yet we should really use
443      * <fp.h> if possible.
444      */
445#    if !defined(__MATH_H__) && !defined(__MATH_H) && !defined(__cmath__)
446#      include <fp.h>
447#    endif
448#  else
449#    include <math.h>
450#  endif
451#  if defined(_AMIGA) && defined(__SASC) && defined(_M68881)
452     /* Amiga SAS/C: We must include builtin FPU functions when compiling using
453      * MATH=68881
454      */
455#    include <m68881.h>
456#  endif
457#endif
458
459/* This provides the non-ANSI (far) memory allocation routines. */
460#if defined(__TURBOC__) && defined(__MSDOS__)
461#  include <mem.h>
462#  include <alloc.h>
463#endif
464
465#if defined(WIN32) || defined(_Windows) || defined(_WINDOWS) || \
466    defined(_WIN32) || defined(__WIN32__)
467#  include <windows.h>  /* defines _WINDOWS_ macro */
468#endif
469#endif /* PNG_VERSION_INFO_ONLY */
470
471/* Moved here around 1.5.0beta36 from pngconf.h */
472/* Users may want to use these so they are not private.  Any library
473 * functions that are passed far data must be model-independent.
474 */
475
476/* Memory model/platform independent fns */
477#ifndef PNG_ABORT
478#  ifdef _WINDOWS_
479#    define PNG_ABORT() ExitProcess(0)
480#  else
481#    define PNG_ABORT() abort()
482#  endif
483#endif
484
485/* These macros may need to be architecture dependent. */
486#define PNG_ALIGN_NONE   0 /* do not use data alignment */
487#define PNG_ALIGN_ALWAYS 1 /* assume unaligned accesses are OK */
488#ifdef offsetof
489#  define PNG_ALIGN_OFFSET 2 /* use offsetof to determine alignment */
490#else
491#  define PNG_ALIGN_OFFSET -1 /* prevent the use of this */
492#endif
493#define PNG_ALIGN_SIZE   3 /* use sizeof to determine alignment */
494
495#ifndef PNG_ALIGN_TYPE
496   /* Default to using aligned access optimizations and requiring alignment to a
497    * multiple of the data type size.  Override in a compiler specific fashion
498    * if necessary by inserting tests here:
499    */
500#  define PNG_ALIGN_TYPE PNG_ALIGN_SIZE
501#endif
502
503#if PNG_ALIGN_TYPE == PNG_ALIGN_SIZE
504   /* This is used because in some compiler implementations non-aligned
505    * structure members are supported, so the offsetof approach below fails.
506    * Set PNG_ALIGN_SIZE=0 for compiler combinations where unaligned access
507    * is good for performance.  Do not do this unless you have tested the result
508    * and understand it.
509    */
510#  define png_alignof(type) (sizeof (type))
511#else
512#  if PNG_ALIGN_TYPE == PNG_ALIGN_OFFSET
513#     define png_alignof(type) offsetof(struct{char c; type t;}, t)
514#  else
515#     if PNG_ALIGN_TYPE == PNG_ALIGN_ALWAYS
516#        define png_alignof(type) (1)
517#     endif
518      /* Else leave png_alignof undefined to prevent use thereof */
519#  endif
520#endif
521
522/* This implicitly assumes alignment is always to a power of 2. */
523#ifdef png_alignof
524#  define png_isaligned(ptr, type)\
525   ((((const char*)ptr-(const char*)0) & (png_alignof(type)-1)) == 0)
526#else
527#  define png_isaligned(ptr, type) 0
528#endif
529
530/* End of memory model/platform independent support */
531/* End of 1.5.0beta36 move from pngconf.h */
532
533/* CONSTANTS and UTILITY MACROS
534 * These are used internally by libpng and not exposed in the API
535 */
536
537/* Various modes of operation.  Note that after an init, mode is set to
538 * zero automatically when the structure is created.  Three of these
539 * are defined in png.h because they need to be visible to applications
540 * that call png_set_unknown_chunk().
541 */
542/* #define PNG_HAVE_IHDR            0x01 (defined in png.h) */
543/* #define PNG_HAVE_PLTE            0x02 (defined in png.h) */
544#define PNG_HAVE_IDAT               0x04
545/* #define PNG_AFTER_IDAT           0x08 (defined in png.h) */
546#define PNG_HAVE_IEND               0x10
547                   /*               0x20 (unused) */
548                   /*               0x40 (unused) */
549                   /*               0x80 (unused) */
550#define PNG_HAVE_CHUNK_HEADER      0x100
551#define PNG_WROTE_tIME             0x200
552#define PNG_WROTE_INFO_BEFORE_PLTE 0x400
553#define PNG_BACKGROUND_IS_GRAY     0x800
554#define PNG_HAVE_PNG_SIGNATURE    0x1000
555#define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000 /* Have another chunk after IDAT */
556                   /*             0x4000 (unused) */
557#define PNG_IS_READ_STRUCT        0x8000 /* Else is a write struct */
558
559/* Flags for the transformations the PNG library does on the image data */
560#define PNG_BGR                 0x0001
561#define PNG_INTERLACE           0x0002
562#define PNG_PACK                0x0004
563#define PNG_SHIFT               0x0008
564#define PNG_SWAP_BYTES          0x0010
565#define PNG_INVERT_MONO         0x0020
566#define PNG_QUANTIZE            0x0040
567#define PNG_COMPOSE             0x0080     /* Was PNG_BACKGROUND */
568#define PNG_BACKGROUND_EXPAND   0x0100
569#define PNG_EXPAND_16           0x0200     /* Added to libpng 1.5.2 */
570#define PNG_16_TO_8             0x0400     /* Becomes 'chop' in 1.5.4 */
571#define PNG_RGBA                0x0800
572#define PNG_EXPAND              0x1000
573#define PNG_GAMMA               0x2000
574#define PNG_GRAY_TO_RGB         0x4000
575#define PNG_FILLER              0x8000
576#define PNG_PACKSWAP           0x10000
577#define PNG_SWAP_ALPHA         0x20000
578#define PNG_STRIP_ALPHA        0x40000
579#define PNG_INVERT_ALPHA       0x80000
580#define PNG_USER_TRANSFORM    0x100000
581#define PNG_RGB_TO_GRAY_ERR   0x200000
582#define PNG_RGB_TO_GRAY_WARN  0x400000
583#define PNG_RGB_TO_GRAY       0x600000 /* two bits, RGB_TO_GRAY_ERR|WARN */
584#define PNG_ENCODE_ALPHA      0x800000 /* Added to libpng-1.5.4 */
585#define PNG_ADD_ALPHA         0x1000000 /* Added to libpng-1.2.7 */
586#define PNG_EXPAND_tRNS       0x2000000 /* Added to libpng-1.2.9 */
587#define PNG_SCALE_16_TO_8     0x4000000 /* Added to libpng-1.5.4 */
588                       /*   0x8000000 unused */
589                       /*  0x10000000 unused */
590                       /*  0x20000000 unused */
591                       /*  0x40000000 unused */
592/* Flags for png_create_struct */
593#define PNG_STRUCT_PNG   0x0001
594#define PNG_STRUCT_INFO  0x0002
595
596/* Scaling factor for filter heuristic weighting calculations */
597#define PNG_WEIGHT_FACTOR (1<<(PNG_WEIGHT_SHIFT))
598#define PNG_COST_FACTOR (1<<(PNG_COST_SHIFT))
599
600/* Flags for the png_ptr->flags rather than declaring a byte for each one */
601#define PNG_FLAG_ZLIB_CUSTOM_STRATEGY     0x0001
602#define PNG_FLAG_ZSTREAM_INITIALIZED      0x0002 /* Added to libpng-1.6.0 */
603                                  /*      0x0004    unused */
604#define PNG_FLAG_ZSTREAM_ENDED            0x0008 /* Added to libpng-1.6.0 */
605                                  /*      0x0010    unused */
606                                  /*      0x0020    unused */
607#define PNG_FLAG_ROW_INIT                 0x0040
608#define PNG_FLAG_FILLER_AFTER             0x0080
609#define PNG_FLAG_CRC_ANCILLARY_USE        0x0100
610#define PNG_FLAG_CRC_ANCILLARY_NOWARN     0x0200
611#define PNG_FLAG_CRC_CRITICAL_USE         0x0400
612#define PNG_FLAG_CRC_CRITICAL_IGNORE      0x0800
613#define PNG_FLAG_ASSUME_sRGB              0x1000 /* Added to libpng-1.5.4 */
614#define PNG_FLAG_OPTIMIZE_ALPHA           0x2000 /* Added to libpng-1.5.4 */
615#define PNG_FLAG_DETECT_UNINITIALIZED     0x4000 /* Added to libpng-1.5.4 */
616/* #define PNG_FLAG_KEEP_UNKNOWN_CHUNKS      0x8000 */
617/* #define PNG_FLAG_KEEP_UNSAFE_CHUNKS      0x10000 */
618#define PNG_FLAG_LIBRARY_MISMATCH        0x20000
619#define PNG_FLAG_STRIP_ERROR_NUMBERS     0x40000
620#define PNG_FLAG_STRIP_ERROR_TEXT        0x80000
621#define PNG_FLAG_BENIGN_ERRORS_WARN     0x100000 /* Added to libpng-1.4.0 */
622#define PNG_FLAG_APP_WARNINGS_WARN      0x200000 /* Added to libpng-1.6.0 */
623#define PNG_FLAG_APP_ERRORS_WARN        0x400000 /* Added to libpng-1.6.0 */
624                                  /*    0x800000    unused */
625                                  /*   0x1000000    unused */
626                                  /*   0x2000000    unused */
627                                  /*   0x4000000    unused */
628                                  /*   0x8000000    unused */
629                                  /*  0x10000000    unused */
630                                  /*  0x20000000    unused */
631                                  /*  0x40000000    unused */
632
633#define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \
634                                     PNG_FLAG_CRC_ANCILLARY_NOWARN)
635
636#define PNG_FLAG_CRC_CRITICAL_MASK  (PNG_FLAG_CRC_CRITICAL_USE | \
637                                     PNG_FLAG_CRC_CRITICAL_IGNORE)
638
639#define PNG_FLAG_CRC_MASK           (PNG_FLAG_CRC_ANCILLARY_MASK | \
640                                     PNG_FLAG_CRC_CRITICAL_MASK)
641
642/* Save typing and make code easier to understand */
643
644#define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \
645   abs((int)((c1).green) - (int)((c2).green)) + \
646   abs((int)((c1).blue) - (int)((c2).blue)))
647
648/* Added to libpng-1.6.0: scale a 16-bit value in the range 0..65535 to 0..255
649 * by dividing by 257 *with rounding*.  This macro is exact for the given range.
650 * See the discourse in pngrtran.c png_do_scale_16_to_8.  The values in the
651 * macro were established by experiment (modifying the added value).  The macro
652 * has a second variant that takes a value already scaled by 255 and divides by
653 * 65535 - this has a maximum error of .502.  Over the range 0..65535*65535 it
654 * only gives off-by-one errors and only for 0.5% (1 in 200) of the values.
655 */
656#define PNG_DIV65535(v24) (((v24) + 32895) >> 16)
657#define PNG_DIV257(v16) PNG_DIV65535((png_uint_32)(v16) * 255)
658
659/* Added to libpng-1.2.6 JB */
660#define PNG_ROWBYTES(pixel_bits, width) \
661    ((pixel_bits) >= 8 ? \
662    ((png_size_t)(width) * (((png_size_t)(pixel_bits)) >> 3)) : \
663    (( ((png_size_t)(width) * ((png_size_t)(pixel_bits))) + 7) >> 3) )
664
665/* PNG_OUT_OF_RANGE returns true if value is outside the range
666 * ideal-delta..ideal+delta.  Each argument is evaluated twice.
667 * "ideal" and "delta" should be constants, normally simple
668 * integers, "value" a variable. Added to libpng-1.2.6 JB
669 */
670#define PNG_OUT_OF_RANGE(value, ideal, delta) \
671   ( (value) < (ideal)-(delta) || (value) > (ideal)+(delta) )
672
673/* Conversions between fixed and floating point, only defined if
674 * required (to make sure the code doesn't accidentally use float
675 * when it is supposedly disabled.)
676 */
677#ifdef PNG_FLOATING_POINT_SUPPORTED
678/* The floating point conversion can't overflow, though it can and
679 * does lose accuracy relative to the original fixed point value.
680 * In practice this doesn't matter because png_fixed_point only
681 * stores numbers with very low precision.  The png_ptr and s
682 * arguments are unused by default but are there in case error
683 * checking becomes a requirement.
684 */
685#define png_float(png_ptr, fixed, s) (.00001 * (fixed))
686
687/* The fixed point conversion performs range checking and evaluates
688 * its argument multiple times, so must be used with care.  The
689 * range checking uses the PNG specification values for a signed
690 * 32 bit fixed point value except that the values are deliberately
691 * rounded-to-zero to an integral value - 21474 (21474.83 is roughly
692 * (2^31-1) * 100000). 's' is a string that describes the value being
693 * converted.
694 *
695 * NOTE: this macro will raise a png_error if the range check fails,
696 * therefore it is normally only appropriate to use this on values
697 * that come from API calls or other sources where an out of range
698 * error indicates a programming error, not a data error!
699 *
700 * NOTE: by default this is off - the macro is not used - because the
701 * function call saves a lot of code.
702 */
703#ifdef PNG_FIXED_POINT_MACRO_SUPPORTED
704#define png_fixed(png_ptr, fp, s) ((fp) <= 21474 && (fp) >= -21474 ?\
705    ((png_fixed_point)(100000 * (fp))) : (png_fixed_error(png_ptr, s),0))
706#endif
707/* else the corresponding function is defined below, inside the scope of the
708 * cplusplus test.
709 */
710#endif
711
712/* Constants for known chunk types.  If you need to add a chunk, define the name
713 * here.  For historical reasons these constants have the form png_<name>; i.e.
714 * the prefix is lower case.  Please use decimal values as the parameters to
715 * match the ISO PNG specification and to avoid relying on the C locale
716 * interpretation of character values.
717 *
718 * Prior to 1.5.6 these constants were strings, as of 1.5.6 png_uint_32 values
719 * are computed and a new macro (PNG_STRING_FROM_CHUNK) added to allow a string
720 * to be generated if required.
721 *
722 * PNG_32b correctly produces a value shifted by up to 24 bits, even on
723 * architectures where (int) is only 16 bits.
724 */
725#define PNG_32b(b,s) ((png_uint_32)(b) << (s))
726#define PNG_U32(b1,b2,b3,b4) \
727   (PNG_32b(b1,24) | PNG_32b(b2,16) | PNG_32b(b3,8) | PNG_32b(b4,0))
728
729/* Constants for known chunk types.
730 *
731 * MAINTAINERS: If you need to add a chunk, define the name here.
732 * For historical reasons these constants have the form png_<name>; i.e.
733 * the prefix is lower case.  Please use decimal values as the parameters to
734 * match the ISO PNG specification and to avoid relying on the C locale
735 * interpretation of character values.  Please keep the list sorted.
736 *
737 * Notice that PNG_U32 is used to define a 32-bit value for the 4 byte chunk
738 * type.  In fact the specification does not express chunk types this way,
739 * however using a 32-bit value means that the chunk type can be read from the
740 * stream using exactly the same code as used for a 32-bit unsigned value and
741 * can be examined far more efficiently (using one arithmetic compare).
742 *
743 * Prior to 1.5.6 the chunk type constants were expressed as C strings.  The
744 * libpng API still uses strings for 'unknown' chunks and a macro,
745 * PNG_STRING_FROM_CHUNK, allows a string to be generated if required.  Notice
746 * that for portable code numeric values must still be used; the string "IHDR"
747 * is not portable and neither is PNG_U32('I', 'H', 'D', 'R').
748 *
749 * In 1.7.0 the definitions will be made public in png.h to avoid having to
750 * duplicate the same definitions in application code.
751 */
752#define png_IDAT PNG_U32( 73,  68,  65,  84)
753#define png_IEND PNG_U32( 73,  69,  78,  68)
754#define png_IHDR PNG_U32( 73,  72,  68,  82)
755#define png_PLTE PNG_U32( 80,  76,  84,  69)
756#define png_bKGD PNG_U32( 98,  75,  71,  68)
757#define png_cHRM PNG_U32( 99,  72,  82,  77)
758#define png_fRAc PNG_U32(102,  82,  65,  99) /* registered, not defined */
759#define png_gAMA PNG_U32(103,  65,  77,  65)
760#define png_gIFg PNG_U32(103,  73,  70, 103)
761#define png_gIFt PNG_U32(103,  73,  70, 116) /* deprecated */
762#define png_gIFx PNG_U32(103,  73,  70, 120)
763#define png_hIST PNG_U32(104,  73,  83,  84)
764#define png_iCCP PNG_U32(105,  67,  67,  80)
765#define png_iTXt PNG_U32(105,  84,  88, 116)
766#define png_oFFs PNG_U32(111,  70,  70, 115)
767#define png_pCAL PNG_U32(112,  67,  65,  76)
768#define png_pHYs PNG_U32(112,  72,  89, 115)
769#define png_sBIT PNG_U32(115,  66,  73,  84)
770#define png_sCAL PNG_U32(115,  67,  65,  76)
771#define png_sPLT PNG_U32(115,  80,  76,  84)
772#define png_sRGB PNG_U32(115,  82,  71,  66)
773#define png_sTER PNG_U32(115,  84,  69,  82)
774#define png_tEXt PNG_U32(116,  69,  88, 116)
775#define png_tIME PNG_U32(116,  73,  77,  69)
776#define png_tRNS PNG_U32(116,  82,  78,  83)
777#define png_zTXt PNG_U32(122,  84,  88, 116)
778
779/* The following will work on (signed char*) strings, whereas the get_uint_32
780 * macro will fail on top-bit-set values because of the sign extension.
781 */
782#define PNG_CHUNK_FROM_STRING(s)\
783   PNG_U32(0xff&(s)[0], 0xff&(s)[1], 0xff&(s)[2], 0xff&(s)[3])
784
785/* This uses (char), not (png_byte) to avoid warnings on systems where (char) is
786 * signed and the argument is a (char[])  This macro will fail miserably on
787 * systems where (char) is more than 8 bits.
788 */
789#define PNG_STRING_FROM_CHUNK(s,c)\
790   (void)(((char*)(s))[0]=(char)((c)>>24), ((char*)(s))[1]=(char)((c)>>16),\
791   ((char*)(s))[2]=(char)((c)>>8), ((char*)(s))[3]=(char)((c)))
792
793/* Do the same but terminate with a null character. */
794#define PNG_CSTRING_FROM_CHUNK(s,c)\
795   (void)(PNG_STRING_FROM_CHUNK(s,c), ((char*)(s))[4] = 0)
796
797/* Test on flag values as defined in the spec (section 5.4): */
798#define PNG_CHUNK_ANCILLARY(c)   (1 & ((c) >> 29))
799#define PNG_CHUNK_CRITICAL(c)     (!PNG_CHUNK_ANCILLARY(c))
800#define PNG_CHUNK_PRIVATE(c)      (1 & ((c) >> 21))
801#define PNG_CHUNK_RESERVED(c)     (1 & ((c) >> 13))
802#define PNG_CHUNK_SAFE_TO_COPY(c) (1 & ((c) >>  5))
803
804/* Gamma values (new at libpng-1.5.4): */
805#define PNG_GAMMA_MAC_OLD 151724  /* Assume '1.8' is really 2.2/1.45! */
806#define PNG_GAMMA_MAC_INVERSE 65909
807#define PNG_GAMMA_sRGB_INVERSE 45455
808
809/* Almost everything below is C specific; the #defines above can be used in
810 * non-C code (so long as it is C-preprocessed) the rest of this stuff cannot.
811 */
812#ifndef PNG_VERSION_INFO_ONLY
813
814#include "pngstruct.h"
815#include "pnginfo.h"
816
817/* Validate the include paths - the include path used to generate pnglibconf.h
818 * must match that used in the build, or we must be using pnglibconf.h.prebuilt:
819 */
820#if PNG_ZLIB_VERNUM != 0 && PNG_ZLIB_VERNUM != ZLIB_VERNUM
821#  error ZLIB_VERNUM != PNG_ZLIB_VERNUM \
822      "-I (include path) error: see the notes in pngpriv.h"
823   /* This means that when pnglibconf.h was built the copy of zlib.h that it
824    * used is not the same as the one being used here.  Because the build of
825    * libpng makes decisions to use inflateInit2 and inflateReset2 based on the
826    * zlib version number and because this affects handling of certain broken
827    * PNG files the -I directives must match.
828    *
829    * The most likely explanation is that you passed a -I in CFLAGS, this will
830    * not work; all the preprocessor directories and in particular all the -I
831    * directives must be in CPPFLAGS.
832    */
833#endif
834
835/* This is used for 16 bit gamma tables -- only the top level pointers are
836 * const; this could be changed:
837 */
838typedef const png_uint_16p * png_const_uint_16pp;
839
840/* Added to libpng-1.5.7: sRGB conversion tables */
841#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
842   defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
843#ifdef PNG_SIMPLIFIED_READ_SUPPORTED
844PNG_INTERNAL_DATA(const png_uint_16, png_sRGB_table, [256]);
845   /* Convert from an sRGB encoded value 0..255 to a 16-bit linear value,
846    * 0..65535.  This table gives the closest 16-bit answers (no errors).
847    */
848#endif
849
850PNG_INTERNAL_DATA(const png_uint_16, png_sRGB_base, [512]);
851PNG_INTERNAL_DATA(const png_byte, png_sRGB_delta, [512]);
852
853#define PNG_sRGB_FROM_LINEAR(linear) ((png_byte)((png_sRGB_base[(linear)>>15] +\
854   ((((linear)&0x7fff)*png_sRGB_delta[(linear)>>15])>>12)) >> 8))
855   /* Given a value 'linear' in the range 0..255*65535 calculate the 8-bit sRGB
856    * encoded value with maximum error 0.646365.  Note that the input is not a
857    * 16-bit value; it has been multiplied by 255! */
858#endif /* PNG_SIMPLIFIED_READ/WRITE */
859
860
861/* Inhibit C++ name-mangling for libpng functions but not for system calls. */
862#ifdef __cplusplus
863extern "C" {
864#endif /* __cplusplus */
865
866/* Internal functions; these are not exported from a DLL however because they
867 * are used within several of the C source files they have to be C extern.
868 *
869 * All of these functions must be declared with PNG_INTERNAL_FUNCTION.
870 */
871
872/* Zlib support */
873#define PNG_UNEXPECTED_ZLIB_RETURN (-7)
874PNG_INTERNAL_FUNCTION(void, png_zstream_error,(png_structrp png_ptr, int ret),
875   PNG_EMPTY);
876   /* Used by the zlib handling functions to ensure that z_stream::msg is always
877    * set before they return.
878    */
879
880#ifdef PNG_WRITE_SUPPORTED
881PNG_INTERNAL_FUNCTION(void,png_free_buffer_list,(png_structrp png_ptr,
882   png_compression_bufferp *list),PNG_EMPTY);
883   /* Free the buffer list used by the compressed write code. */
884#endif
885
886#if defined(PNG_FLOATING_POINT_SUPPORTED) && \
887   !defined(PNG_FIXED_POINT_MACRO_SUPPORTED) && \
888   (defined(PNG_gAMA_SUPPORTED) || defined(PNG_cHRM_SUPPORTED) || \
889   defined(PNG_sCAL_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) || \
890   defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)) || \
891   (defined(PNG_sCAL_SUPPORTED) && \
892   defined(PNG_FLOATING_ARITHMETIC_SUPPORTED))
893PNG_INTERNAL_FUNCTION(png_fixed_point,png_fixed,(png_const_structrp png_ptr,
894   double fp, png_const_charp text),PNG_EMPTY);
895#endif
896
897/* Check the user version string for compatibility, returns false if the version
898 * numbers aren't compatible.
899 */
900PNG_INTERNAL_FUNCTION(int,png_user_version_check,(png_structrp png_ptr,
901   png_const_charp user_png_ver),PNG_EMPTY);
902
903/* Internal base allocator - no messages, NULL on failure to allocate.  This
904 * does, however, call the application provided allocator and that could call
905 * png_error (although that would be a bug in the application implementation.)
906 */
907PNG_INTERNAL_FUNCTION(png_voidp,png_malloc_base,(png_const_structrp png_ptr,
908   png_alloc_size_t size),PNG_ALLOCATED);
909
910#if defined(PNG_TEXT_SUPPORTED) || defined(PNG_sPLT_SUPPORTED) ||\
911   defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED)
912/* Internal array allocator, outputs no error or warning messages on failure,
913 * just returns NULL.
914 */
915PNG_INTERNAL_FUNCTION(png_voidp,png_malloc_array,(png_const_structrp png_ptr,
916   int nelements, size_t element_size),PNG_ALLOCATED);
917
918/* The same but an existing array is extended by add_elements.  This function
919 * also memsets the new elements to 0 and copies the old elements.  The old
920 * array is not freed or altered.
921 */
922PNG_INTERNAL_FUNCTION(png_voidp,png_realloc_array,(png_const_structrp png_ptr,
923   png_const_voidp array, int old_elements, int add_elements,
924   size_t element_size),PNG_ALLOCATED);
925#endif /* text, sPLT or unknown chunks */
926
927/* Magic to create a struct when there is no struct to call the user supplied
928 * memory allocators.  Because error handling has not been set up the memory
929 * handlers can't safely call png_error, but this is an obscure and undocumented
930 * restriction so libpng has to assume that the 'free' handler, at least, might
931 * call png_error.
932 */
933PNG_INTERNAL_FUNCTION(png_structp,png_create_png_struct,
934   (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
935    png_error_ptr warn_fn, png_voidp mem_ptr, png_malloc_ptr malloc_fn,
936    png_free_ptr free_fn),PNG_ALLOCATED);
937
938/* Free memory from internal libpng struct */
939PNG_INTERNAL_FUNCTION(void,png_destroy_png_struct,(png_structrp png_ptr),
940   PNG_EMPTY);
941
942/* Free an allocated jmp_buf (always succeeds) */
943PNG_INTERNAL_FUNCTION(void,png_free_jmpbuf,(png_structrp png_ptr),PNG_EMPTY);
944
945/* Function to allocate memory for zlib.  PNGAPI is disallowed. */
946PNG_INTERNAL_FUNCTION(voidpf,png_zalloc,(voidpf png_ptr, uInt items, uInt size),
947   PNG_ALLOCATED);
948
949/* Function to free memory for zlib.  PNGAPI is disallowed. */
950PNG_INTERNAL_FUNCTION(void,png_zfree,(voidpf png_ptr, voidpf ptr),PNG_EMPTY);
951
952/* Next four functions are used internally as callbacks.  PNGCBAPI is required
953 * but not PNG_EXPORT.  PNGAPI added at libpng version 1.2.3, changed to
954 * PNGCBAPI at 1.5.0
955 */
956
957PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_read_data,(png_structp png_ptr,
958    png_bytep data, png_size_t length),PNG_EMPTY);
959
960#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
961PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_push_fill_buffer,(png_structp png_ptr,
962    png_bytep buffer, png_size_t length),PNG_EMPTY);
963#endif
964
965PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_write_data,(png_structp png_ptr,
966    png_bytep data, png_size_t length),PNG_EMPTY);
967
968#ifdef PNG_WRITE_FLUSH_SUPPORTED
969#  ifdef PNG_STDIO_SUPPORTED
970PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_flush,(png_structp png_ptr),
971   PNG_EMPTY);
972#  endif
973#endif
974
975/* Reset the CRC variable */
976PNG_INTERNAL_FUNCTION(void,png_reset_crc,(png_structrp png_ptr),PNG_EMPTY);
977
978/* Write the "data" buffer to whatever output you are using */
979PNG_INTERNAL_FUNCTION(void,png_write_data,(png_structrp png_ptr,
980    png_const_bytep data, png_size_t length),PNG_EMPTY);
981
982/* Read and check the PNG file signature */
983PNG_INTERNAL_FUNCTION(void,png_read_sig,(png_structrp png_ptr,
984   png_inforp info_ptr),PNG_EMPTY);
985
986/* Read the chunk header (length + type name) */
987PNG_INTERNAL_FUNCTION(png_uint_32,png_read_chunk_header,(png_structrp png_ptr),
988   PNG_EMPTY);
989
990/* Read data from whatever input you are using into the "data" buffer */
991PNG_INTERNAL_FUNCTION(void,png_read_data,(png_structrp png_ptr, png_bytep data,
992    png_size_t length),PNG_EMPTY);
993
994/* Read bytes into buf, and update png_ptr->crc */
995PNG_INTERNAL_FUNCTION(void,png_crc_read,(png_structrp png_ptr, png_bytep buf,
996    png_uint_32 length),PNG_EMPTY);
997
998/* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */
999PNG_INTERNAL_FUNCTION(int,png_crc_finish,(png_structrp png_ptr,
1000   png_uint_32 skip),PNG_EMPTY);
1001
1002/* Read the CRC from the file and compare it to the libpng calculated CRC */
1003PNG_INTERNAL_FUNCTION(int,png_crc_error,(png_structrp png_ptr),PNG_EMPTY);
1004
1005/* Calculate the CRC over a section of data.  Note that we are only
1006 * passing a maximum of 64K on systems that have this as a memory limit,
1007 * since this is the maximum buffer size we can specify.
1008 */
1009PNG_INTERNAL_FUNCTION(void,png_calculate_crc,(png_structrp png_ptr,
1010   png_const_bytep ptr, png_size_t length),PNG_EMPTY);
1011
1012#ifdef PNG_WRITE_FLUSH_SUPPORTED
1013PNG_INTERNAL_FUNCTION(void,png_flush,(png_structrp png_ptr),PNG_EMPTY);
1014#endif
1015
1016/* Write various chunks */
1017
1018/* Write the IHDR chunk, and update the png_struct with the necessary
1019 * information.
1020 */
1021PNG_INTERNAL_FUNCTION(void,png_write_IHDR,(png_structrp png_ptr,
1022   png_uint_32 width, png_uint_32 height, int bit_depth, int color_type,
1023   int compression_method, int filter_method, int interlace_method),PNG_EMPTY);
1024
1025PNG_INTERNAL_FUNCTION(void,png_write_PLTE,(png_structrp png_ptr,
1026   png_const_colorp palette, png_uint_32 num_pal),PNG_EMPTY);
1027
1028PNG_INTERNAL_FUNCTION(void,png_compress_IDAT,(png_structrp png_ptr,
1029   png_const_bytep row_data, png_alloc_size_t row_data_length, int flush),
1030   PNG_EMPTY);
1031
1032PNG_INTERNAL_FUNCTION(void,png_write_IEND,(png_structrp png_ptr),PNG_EMPTY);
1033
1034#ifdef PNG_WRITE_gAMA_SUPPORTED
1035PNG_INTERNAL_FUNCTION(void,png_write_gAMA_fixed,(png_structrp png_ptr,
1036    png_fixed_point file_gamma),PNG_EMPTY);
1037#endif
1038
1039#ifdef PNG_WRITE_sBIT_SUPPORTED
1040PNG_INTERNAL_FUNCTION(void,png_write_sBIT,(png_structrp png_ptr,
1041    png_const_color_8p sbit, int color_type),PNG_EMPTY);
1042#endif
1043
1044#ifdef PNG_WRITE_cHRM_SUPPORTED
1045PNG_INTERNAL_FUNCTION(void,png_write_cHRM_fixed,(png_structrp png_ptr,
1046    const png_xy *xy), PNG_EMPTY);
1047    /* The xy value must have been previously validated */
1048#endif
1049
1050#ifdef PNG_WRITE_sRGB_SUPPORTED
1051PNG_INTERNAL_FUNCTION(void,png_write_sRGB,(png_structrp png_ptr,
1052    int intent),PNG_EMPTY);
1053#endif
1054
1055#ifdef PNG_WRITE_iCCP_SUPPORTED
1056PNG_INTERNAL_FUNCTION(void,png_write_iCCP,(png_structrp png_ptr,
1057   png_const_charp name, png_const_bytep profile), PNG_EMPTY);
1058   /* The profile must have been previously validated for correctness, the
1059    * length comes from the first four bytes.  Only the base, deflate,
1060    * compression is supported.
1061    */
1062#endif
1063
1064#ifdef PNG_WRITE_sPLT_SUPPORTED
1065PNG_INTERNAL_FUNCTION(void,png_write_sPLT,(png_structrp png_ptr,
1066    png_const_sPLT_tp palette),PNG_EMPTY);
1067#endif
1068
1069#ifdef PNG_WRITE_tRNS_SUPPORTED
1070PNG_INTERNAL_FUNCTION(void,png_write_tRNS,(png_structrp png_ptr,
1071    png_const_bytep trans, png_const_color_16p values, int number,
1072    int color_type),PNG_EMPTY);
1073#endif
1074
1075#ifdef PNG_WRITE_bKGD_SUPPORTED
1076PNG_INTERNAL_FUNCTION(void,png_write_bKGD,(png_structrp png_ptr,
1077    png_const_color_16p values, int color_type),PNG_EMPTY);
1078#endif
1079
1080#ifdef PNG_WRITE_hIST_SUPPORTED
1081PNG_INTERNAL_FUNCTION(void,png_write_hIST,(png_structrp png_ptr,
1082    png_const_uint_16p hist, int num_hist),PNG_EMPTY);
1083#endif
1084
1085/* Chunks that have keywords */
1086#ifdef PNG_WRITE_tEXt_SUPPORTED
1087PNG_INTERNAL_FUNCTION(void,png_write_tEXt,(png_structrp png_ptr,
1088   png_const_charp key, png_const_charp text, png_size_t text_len),PNG_EMPTY);
1089#endif
1090
1091#ifdef PNG_WRITE_zTXt_SUPPORTED
1092PNG_INTERNAL_FUNCTION(void,png_write_zTXt,(png_structrp png_ptr, png_const_charp
1093    key, png_const_charp text, png_size_t text_len, int compression),PNG_EMPTY);
1094#endif
1095
1096#ifdef PNG_WRITE_iTXt_SUPPORTED
1097PNG_INTERNAL_FUNCTION(void,png_write_iTXt,(png_structrp png_ptr,
1098    int compression, png_const_charp key, png_const_charp lang,
1099    png_const_charp lang_key, png_const_charp text),PNG_EMPTY);
1100#endif
1101
1102#ifdef PNG_TEXT_SUPPORTED  /* Added at version 1.0.14 and 1.2.4 */
1103PNG_INTERNAL_FUNCTION(int,png_set_text_2,(png_const_structrp png_ptr,
1104    png_inforp info_ptr, png_const_textp text_ptr, int num_text),PNG_EMPTY);
1105#endif
1106
1107#ifdef PNG_WRITE_oFFs_SUPPORTED
1108PNG_INTERNAL_FUNCTION(void,png_write_oFFs,(png_structrp png_ptr,
1109    png_int_32 x_offset, png_int_32 y_offset, int unit_type),PNG_EMPTY);
1110#endif
1111
1112#ifdef PNG_WRITE_pCAL_SUPPORTED
1113PNG_INTERNAL_FUNCTION(void,png_write_pCAL,(png_structrp png_ptr,
1114    png_charp purpose, png_int_32 X0, png_int_32 X1, int type, int nparams,
1115    png_const_charp units, png_charpp params),PNG_EMPTY);
1116#endif
1117
1118#ifdef PNG_WRITE_pHYs_SUPPORTED
1119PNG_INTERNAL_FUNCTION(void,png_write_pHYs,(png_structrp png_ptr,
1120    png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit,
1121    int unit_type),PNG_EMPTY);
1122#endif
1123
1124#ifdef PNG_WRITE_tIME_SUPPORTED
1125PNG_INTERNAL_FUNCTION(void,png_write_tIME,(png_structrp png_ptr,
1126    png_const_timep mod_time),PNG_EMPTY);
1127#endif
1128
1129#ifdef PNG_WRITE_sCAL_SUPPORTED
1130PNG_INTERNAL_FUNCTION(void,png_write_sCAL_s,(png_structrp png_ptr,
1131    int unit, png_const_charp width, png_const_charp height),PNG_EMPTY);
1132#endif
1133
1134/* Called when finished processing a row of data */
1135PNG_INTERNAL_FUNCTION(void,png_write_finish_row,(png_structrp png_ptr),
1136    PNG_EMPTY);
1137
1138/* Internal use only.   Called before first row of data */
1139PNG_INTERNAL_FUNCTION(void,png_write_start_row,(png_structrp png_ptr),
1140    PNG_EMPTY);
1141
1142/* Combine a row of data, dealing with alpha, etc. if requested.  'row' is an
1143 * array of png_ptr->width pixels.  If the image is not interlaced or this
1144 * is the final pass this just does a memcpy, otherwise the "display" flag
1145 * is used to determine whether to copy pixels that are not in the current pass.
1146 *
1147 * Because 'png_do_read_interlace' (below) replicates pixels this allows this
1148 * function to achieve the documented 'blocky' appearance during interlaced read
1149 * if display is 1 and the 'sparkle' appearance, where existing pixels in 'row'
1150 * are not changed if they are not in the current pass, when display is 0.
1151 *
1152 * 'display' must be 0 or 1, otherwise the memcpy will be done regardless.
1153 *
1154 * The API always reads from the png_struct row buffer and always assumes that
1155 * it is full width (png_do_read_interlace has already been called.)
1156 *
1157 * This function is only ever used to write to row buffers provided by the
1158 * caller of the relevant libpng API and the row must have already been
1159 * transformed by the read transformations.
1160 *
1161 * The PNG_USE_COMPILE_TIME_MASKS option causes generation of pre-computed
1162 * bitmasks for use within the code, otherwise runtime generated masks are used.
1163 * The default is compile time masks.
1164 */
1165#ifndef PNG_USE_COMPILE_TIME_MASKS
1166#  define PNG_USE_COMPILE_TIME_MASKS 1
1167#endif
1168PNG_INTERNAL_FUNCTION(void,png_combine_row,(png_const_structrp png_ptr,
1169    png_bytep row, int display),PNG_EMPTY);
1170
1171#ifdef PNG_READ_INTERLACING_SUPPORTED
1172/* Expand an interlaced row: the 'row_info' describes the pass data that has
1173 * been read in and must correspond to the pixels in 'row', the pixels are
1174 * expanded (moved apart) in 'row' to match the final layout, when doing this
1175 * the pixels are *replicated* to the intervening space.  This is essential for
1176 * the correct operation of png_combine_row, above.
1177 */
1178PNG_INTERNAL_FUNCTION(void,png_do_read_interlace,(png_row_infop row_info,
1179    png_bytep row, int pass, png_uint_32 transformations),PNG_EMPTY);
1180#endif
1181
1182/* GRR TO DO (2.0 or whenever):  simplify other internal calling interfaces */
1183
1184#ifdef PNG_WRITE_INTERLACING_SUPPORTED
1185/* Grab pixels out of a row for an interlaced pass */
1186PNG_INTERNAL_FUNCTION(void,png_do_write_interlace,(png_row_infop row_info,
1187    png_bytep row, int pass),PNG_EMPTY);
1188#endif
1189
1190/* Unfilter a row: check the filter value before calling this, there is no point
1191 * calling it for PNG_FILTER_VALUE_NONE.
1192 */
1193PNG_INTERNAL_FUNCTION(void,png_read_filter_row,(png_structrp pp, png_row_infop
1194    row_info, png_bytep row, png_const_bytep prev_row, int filter),PNG_EMPTY);
1195
1196PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_neon,(png_row_infop row_info,
1197    png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1198PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_neon,(png_row_infop
1199    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1200PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_neon,(png_row_infop
1201    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1202PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_neon,(png_row_infop
1203    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1204PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_neon,(png_row_infop
1205    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1206PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_neon,(png_row_infop
1207    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1208PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_neon,(png_row_infop
1209    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1210
1211/* Choose the best filter to use and filter the row data */
1212PNG_INTERNAL_FUNCTION(void,png_write_find_filter,(png_structrp png_ptr,
1213    png_row_infop row_info),PNG_EMPTY);
1214
1215#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1216PNG_INTERNAL_FUNCTION(void,png_read_IDAT_data,(png_structrp png_ptr,
1217   png_bytep output, png_alloc_size_t avail_out),PNG_EMPTY);
1218   /* Read 'avail_out' bytes of data from the IDAT stream.  If the output buffer
1219    * is NULL the function checks, instead, for the end of the stream.  In this
1220    * case a benign error will be issued if the stream end is not found or if
1221    * extra data has to be consumed.
1222    */
1223PNG_INTERNAL_FUNCTION(void,png_read_finish_IDAT,(png_structrp png_ptr),
1224   PNG_EMPTY);
1225   /* This cleans up when the IDAT LZ stream does not end when the last image
1226    * byte is read; there is still some pending input.
1227    */
1228
1229PNG_INTERNAL_FUNCTION(void,png_read_finish_row,(png_structrp png_ptr),
1230   PNG_EMPTY);
1231   /* Finish a row while reading, dealing with interlacing passes, etc. */
1232#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
1233
1234/* Initialize the row buffers, etc. */
1235PNG_INTERNAL_FUNCTION(void,png_read_start_row,(png_structrp png_ptr),PNG_EMPTY);
1236
1237#ifdef PNG_READ_TRANSFORMS_SUPPORTED
1238/* Optional call to update the users info structure */
1239PNG_INTERNAL_FUNCTION(void,png_read_transform_info,(png_structrp png_ptr,
1240    png_inforp info_ptr),PNG_EMPTY);
1241#endif
1242
1243/* Shared transform functions, defined in pngtran.c */
1244#if defined(PNG_WRITE_FILLER_SUPPORTED) || \
1245    defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
1246PNG_INTERNAL_FUNCTION(void,png_do_strip_channel,(png_row_infop row_info,
1247    png_bytep row, int at_start),PNG_EMPTY);
1248#endif
1249
1250#ifdef PNG_16BIT_SUPPORTED
1251#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
1252PNG_INTERNAL_FUNCTION(void,png_do_swap,(png_row_infop row_info,
1253    png_bytep row),PNG_EMPTY);
1254#endif
1255#endif
1256
1257#if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
1258    defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1259PNG_INTERNAL_FUNCTION(void,png_do_packswap,(png_row_infop row_info,
1260    png_bytep row),PNG_EMPTY);
1261#endif
1262
1263#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
1264PNG_INTERNAL_FUNCTION(void,png_do_invert,(png_row_infop row_info,
1265    png_bytep row),PNG_EMPTY);
1266#endif
1267
1268#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
1269PNG_INTERNAL_FUNCTION(void,png_do_bgr,(png_row_infop row_info,
1270    png_bytep row),PNG_EMPTY);
1271#endif
1272
1273/* The following decodes the appropriate chunks, and does error correction,
1274 * then calls the appropriate callback for the chunk if it is valid.
1275 */
1276
1277/* Decode the IHDR chunk */
1278PNG_INTERNAL_FUNCTION(void,png_handle_IHDR,(png_structrp png_ptr,
1279    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1280PNG_INTERNAL_FUNCTION(void,png_handle_PLTE,(png_structrp png_ptr,
1281    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1282PNG_INTERNAL_FUNCTION(void,png_handle_IEND,(png_structrp png_ptr,
1283    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1284
1285#ifdef PNG_READ_bKGD_SUPPORTED
1286PNG_INTERNAL_FUNCTION(void,png_handle_bKGD,(png_structrp png_ptr,
1287    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1288#endif
1289
1290#ifdef PNG_READ_cHRM_SUPPORTED
1291PNG_INTERNAL_FUNCTION(void,png_handle_cHRM,(png_structrp png_ptr,
1292    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1293#endif
1294
1295#ifdef PNG_READ_gAMA_SUPPORTED
1296PNG_INTERNAL_FUNCTION(void,png_handle_gAMA,(png_structrp png_ptr,
1297    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1298#endif
1299
1300#ifdef PNG_READ_hIST_SUPPORTED
1301PNG_INTERNAL_FUNCTION(void,png_handle_hIST,(png_structrp png_ptr,
1302    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1303#endif
1304
1305#ifdef PNG_READ_iCCP_SUPPORTED
1306PNG_INTERNAL_FUNCTION(void,png_handle_iCCP,(png_structrp png_ptr,
1307    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1308#endif /* PNG_READ_iCCP_SUPPORTED */
1309
1310#ifdef PNG_READ_iTXt_SUPPORTED
1311PNG_INTERNAL_FUNCTION(void,png_handle_iTXt,(png_structrp png_ptr,
1312    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1313#endif
1314
1315#ifdef PNG_READ_oFFs_SUPPORTED
1316PNG_INTERNAL_FUNCTION(void,png_handle_oFFs,(png_structrp png_ptr,
1317    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1318#endif
1319
1320#ifdef PNG_READ_pCAL_SUPPORTED
1321PNG_INTERNAL_FUNCTION(void,png_handle_pCAL,(png_structrp png_ptr,
1322    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1323#endif
1324
1325#ifdef PNG_READ_pHYs_SUPPORTED
1326PNG_INTERNAL_FUNCTION(void,png_handle_pHYs,(png_structrp png_ptr,
1327    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1328#endif
1329
1330#ifdef PNG_READ_sBIT_SUPPORTED
1331PNG_INTERNAL_FUNCTION(void,png_handle_sBIT,(png_structrp png_ptr,
1332    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1333#endif
1334
1335#ifdef PNG_READ_sCAL_SUPPORTED
1336PNG_INTERNAL_FUNCTION(void,png_handle_sCAL,(png_structrp png_ptr,
1337    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1338#endif
1339
1340#ifdef PNG_READ_sPLT_SUPPORTED
1341PNG_INTERNAL_FUNCTION(void,png_handle_sPLT,(png_structrp png_ptr,
1342    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1343#endif /* PNG_READ_sPLT_SUPPORTED */
1344
1345#ifdef PNG_READ_sRGB_SUPPORTED
1346PNG_INTERNAL_FUNCTION(void,png_handle_sRGB,(png_structrp png_ptr,
1347    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1348#endif
1349
1350#ifdef PNG_READ_tEXt_SUPPORTED
1351PNG_INTERNAL_FUNCTION(void,png_handle_tEXt,(png_structrp png_ptr,
1352    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1353#endif
1354
1355#ifdef PNG_READ_tIME_SUPPORTED
1356PNG_INTERNAL_FUNCTION(void,png_handle_tIME,(png_structrp png_ptr,
1357    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1358#endif
1359
1360#ifdef PNG_READ_tRNS_SUPPORTED
1361PNG_INTERNAL_FUNCTION(void,png_handle_tRNS,(png_structrp png_ptr,
1362    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1363#endif
1364
1365#ifdef PNG_READ_zTXt_SUPPORTED
1366PNG_INTERNAL_FUNCTION(void,png_handle_zTXt,(png_structrp png_ptr,
1367    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1368#endif
1369
1370PNG_INTERNAL_FUNCTION(void,png_check_chunk_name,(png_structrp png_ptr,
1371    png_uint_32 chunk_name),PNG_EMPTY);
1372
1373PNG_INTERNAL_FUNCTION(void,png_handle_unknown,(png_structrp png_ptr,
1374    png_inforp info_ptr, png_uint_32 length, int keep),PNG_EMPTY);
1375   /* This is the function that gets called for unknown chunks.  The 'keep'
1376    * argument is either non-zero for a known chunk that has been set to be
1377    * handled as unknown or zero for an unknown chunk.  By default the function
1378    * just skips the chunk or errors out if it is critical.
1379    */
1380
1381#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) ||\
1382    defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
1383PNG_INTERNAL_FUNCTION(int,png_chunk_unknown_handling,
1384    (png_const_structrp png_ptr, png_uint_32 chunk_name),PNG_EMPTY);
1385   /* Exactly as the API png_handle_as_unknown() except that the argument is a
1386    * 32-bit chunk name, not a string.
1387    */
1388#endif /* READ_UNKNOWN_CHUNKS || HANDLE_AS_UNKNOWN */
1389
1390/* Handle the transformations for reading and writing */
1391#ifdef PNG_READ_TRANSFORMS_SUPPORTED
1392PNG_INTERNAL_FUNCTION(void,png_do_read_transformations,(png_structrp png_ptr,
1393   png_row_infop row_info),PNG_EMPTY);
1394#endif
1395#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
1396PNG_INTERNAL_FUNCTION(void,png_do_write_transformations,(png_structrp png_ptr,
1397   png_row_infop row_info),PNG_EMPTY);
1398#endif
1399
1400#ifdef PNG_READ_TRANSFORMS_SUPPORTED
1401PNG_INTERNAL_FUNCTION(void,png_init_read_transformations,(png_structrp png_ptr),
1402    PNG_EMPTY);
1403#endif
1404
1405#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1406PNG_INTERNAL_FUNCTION(void,png_push_read_chunk,(png_structrp png_ptr,
1407    png_inforp info_ptr),PNG_EMPTY);
1408PNG_INTERNAL_FUNCTION(void,png_push_read_sig,(png_structrp png_ptr,
1409    png_inforp info_ptr),PNG_EMPTY);
1410PNG_INTERNAL_FUNCTION(void,png_push_check_crc,(png_structrp png_ptr),PNG_EMPTY);
1411PNG_INTERNAL_FUNCTION(void,png_push_crc_skip,(png_structrp png_ptr,
1412    png_uint_32 length),PNG_EMPTY);
1413PNG_INTERNAL_FUNCTION(void,png_push_crc_finish,(png_structrp png_ptr),
1414    PNG_EMPTY);
1415PNG_INTERNAL_FUNCTION(void,png_push_save_buffer,(png_structrp png_ptr),
1416    PNG_EMPTY);
1417PNG_INTERNAL_FUNCTION(void,png_push_restore_buffer,(png_structrp png_ptr,
1418    png_bytep buffer, png_size_t buffer_length),PNG_EMPTY);
1419PNG_INTERNAL_FUNCTION(void,png_push_read_IDAT,(png_structrp png_ptr),PNG_EMPTY);
1420PNG_INTERNAL_FUNCTION(void,png_process_IDAT_data,(png_structrp png_ptr,
1421    png_bytep buffer, png_size_t buffer_length),PNG_EMPTY);
1422PNG_INTERNAL_FUNCTION(void,png_push_process_row,(png_structrp png_ptr),
1423    PNG_EMPTY);
1424PNG_INTERNAL_FUNCTION(void,png_push_handle_unknown,(png_structrp png_ptr,
1425   png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1426PNG_INTERNAL_FUNCTION(void,png_push_have_info,(png_structrp png_ptr,
1427   png_inforp info_ptr),PNG_EMPTY);
1428PNG_INTERNAL_FUNCTION(void,png_push_have_end,(png_structrp png_ptr,
1429   png_inforp info_ptr),PNG_EMPTY);
1430PNG_INTERNAL_FUNCTION(void,png_push_have_row,(png_structrp png_ptr,
1431     png_bytep row),PNG_EMPTY);
1432PNG_INTERNAL_FUNCTION(void,png_push_read_end,(png_structrp png_ptr,
1433    png_inforp info_ptr),PNG_EMPTY);
1434PNG_INTERNAL_FUNCTION(void,png_process_some_data,(png_structrp png_ptr,
1435    png_inforp info_ptr),PNG_EMPTY);
1436PNG_INTERNAL_FUNCTION(void,png_read_push_finish_row,(png_structrp png_ptr),
1437    PNG_EMPTY);
1438#  ifdef PNG_READ_tEXt_SUPPORTED
1439PNG_INTERNAL_FUNCTION(void,png_push_handle_tEXt,(png_structrp png_ptr,
1440    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1441PNG_INTERNAL_FUNCTION(void,png_push_read_tEXt,(png_structrp png_ptr,
1442    png_inforp info_ptr),PNG_EMPTY);
1443#  endif
1444#  ifdef PNG_READ_zTXt_SUPPORTED
1445PNG_INTERNAL_FUNCTION(void,png_push_handle_zTXt,(png_structrp png_ptr,
1446    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1447PNG_INTERNAL_FUNCTION(void,png_push_read_zTXt,(png_structrp png_ptr,
1448    png_inforp info_ptr),PNG_EMPTY);
1449#  endif
1450#  ifdef PNG_READ_iTXt_SUPPORTED
1451PNG_INTERNAL_FUNCTION(void,png_push_handle_iTXt,(png_structrp png_ptr,
1452    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1453PNG_INTERNAL_FUNCTION(void,png_push_read_iTXt,(png_structrp png_ptr,
1454    png_inforp info_ptr),PNG_EMPTY);
1455#  endif
1456
1457#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
1458
1459/* Added at libpng version 1.6.0 */
1460#ifdef PNG_GAMMA_SUPPORTED
1461PNG_INTERNAL_FUNCTION(void,png_colorspace_set_gamma,(png_const_structrp png_ptr,
1462    png_colorspacerp colorspace, png_fixed_point gAMA), PNG_EMPTY);
1463   /* Set the colorspace gamma with a value provided by the application or by
1464    * the gAMA chunk on read.  The value will override anything set by an ICC
1465    * profile.
1466    */
1467
1468PNG_INTERNAL_FUNCTION(void,png_colorspace_sync_info,(png_const_structrp png_ptr,
1469    png_inforp info_ptr), PNG_EMPTY);
1470    /* Synchronize the info 'valid' flags with the colorspace */
1471
1472PNG_INTERNAL_FUNCTION(void,png_colorspace_sync,(png_const_structrp png_ptr,
1473    png_inforp info_ptr), PNG_EMPTY);
1474    /* Copy the png_struct colorspace to the info_struct and call the above to
1475     * synchronize the flags.  Checks for NULL info_ptr and does nothing.
1476     */
1477#endif
1478
1479/* Added at libpng version 1.4.0 */
1480#ifdef PNG_COLORSPACE_SUPPORTED
1481/* These internal functions are for maintaining the colorspace structure within
1482 * a png_info or png_struct (or, indeed, both).
1483 */
1484PNG_INTERNAL_FUNCTION(int,png_colorspace_set_chromaticities,
1485   (png_const_structrp png_ptr, png_colorspacerp colorspace, const png_xy *xy,
1486    int preferred), PNG_EMPTY);
1487
1488PNG_INTERNAL_FUNCTION(int,png_colorspace_set_endpoints,
1489   (png_const_structrp png_ptr, png_colorspacerp colorspace, const png_XYZ *XYZ,
1490    int preferred), PNG_EMPTY);
1491
1492#ifdef PNG_sRGB_SUPPORTED
1493PNG_INTERNAL_FUNCTION(int,png_colorspace_set_sRGB,(png_const_structrp png_ptr,
1494   png_colorspacerp colorspace, int intent), PNG_EMPTY);
1495   /* This does set the colorspace gAMA and cHRM values too, but doesn't set the
1496    * flags to write them, if it returns false there was a problem and an error
1497    * message has already been output (but the colorspace may still need to be
1498    * synced to record the invalid flag).
1499    */
1500#endif /* sRGB */
1501
1502#ifdef PNG_iCCP_SUPPORTED
1503PNG_INTERNAL_FUNCTION(int,png_colorspace_set_ICC,(png_const_structrp png_ptr,
1504   png_colorspacerp colorspace, png_const_charp name,
1505   png_uint_32 profile_length, png_const_bytep profile, int color_type),
1506   PNG_EMPTY);
1507   /* The 'name' is used for information only */
1508
1509/* Routines for checking parts of an ICC profile. */
1510PNG_INTERNAL_FUNCTION(int,png_icc_check_length,(png_const_structrp png_ptr,
1511   png_colorspacerp colorspace, png_const_charp name,
1512   png_uint_32 profile_length), PNG_EMPTY);
1513PNG_INTERNAL_FUNCTION(int,png_icc_check_header,(png_const_structrp png_ptr,
1514   png_colorspacerp colorspace, png_const_charp name,
1515   png_uint_32 profile_length,
1516   png_const_bytep profile /* first 132 bytes only */, int color_type),
1517   PNG_EMPTY);
1518PNG_INTERNAL_FUNCTION(int,png_icc_check_tag_table,(png_const_structrp png_ptr,
1519   png_colorspacerp colorspace, png_const_charp name,
1520   png_uint_32 profile_length,
1521   png_const_bytep profile /* header plus whole tag table */), PNG_EMPTY);
1522#ifdef PNG_sRGB_SUPPORTED
1523PNG_INTERNAL_FUNCTION(void,png_icc_set_sRGB,(
1524   png_const_structrp png_ptr, png_colorspacerp colorspace,
1525   png_const_bytep profile, uLong adler), PNG_EMPTY);
1526   /* 'adler' is the Adler32 checksum of the uncompressed profile data. It may
1527    * be zero to indicate that it is not available.  It is used, if provided,
1528    * as a fast check on the profile when checking to see if it is sRGB.
1529    */
1530#endif
1531#endif /* iCCP */
1532
1533#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1534PNG_INTERNAL_FUNCTION(void,png_colorspace_set_rgb_coefficients,
1535   (png_structrp png_ptr), PNG_EMPTY);
1536   /* Set the rgb_to_gray coefficients from the colorspace Y values */
1537#endif /* READ_RGB_TO_GRAY */
1538#endif /* COLORSPACE */
1539
1540/* Added at libpng version 1.4.0 */
1541PNG_INTERNAL_FUNCTION(void,png_check_IHDR,(png_const_structrp png_ptr,
1542    png_uint_32 width, png_uint_32 height, int bit_depth,
1543    int color_type, int interlace_type, int compression_type,
1544    int filter_type),PNG_EMPTY);
1545
1546/* Added at libpng version 1.5.10 */
1547#if defined(PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED) || \
1548    defined(PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED)
1549PNG_INTERNAL_FUNCTION(void,png_do_check_palette_indexes,
1550   (png_structrp png_ptr, png_row_infop row_info),PNG_EMPTY);
1551#endif
1552
1553#if defined(PNG_FLOATING_POINT_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED)
1554PNG_INTERNAL_FUNCTION(void,png_fixed_error,(png_const_structrp png_ptr,
1555   png_const_charp name),PNG_NORETURN);
1556#endif
1557
1558/* Puts 'string' into 'buffer' at buffer[pos], taking care never to overwrite
1559 * the end.  Always leaves the buffer nul terminated.  Never errors out (and
1560 * there is no error code.)
1561 */
1562PNG_INTERNAL_FUNCTION(size_t,png_safecat,(png_charp buffer, size_t bufsize,
1563   size_t pos, png_const_charp string),PNG_EMPTY);
1564
1565/* Various internal functions to handle formatted warning messages, currently
1566 * only implemented for warnings.
1567 */
1568#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_SUPPORTED)
1569/* Utility to dump an unsigned value into a buffer, given a start pointer and
1570 * and end pointer (which should point just *beyond* the end of the buffer!)
1571 * Returns the pointer to the start of the formatted string.  This utility only
1572 * does unsigned values.
1573 */
1574PNG_INTERNAL_FUNCTION(png_charp,png_format_number,(png_const_charp start,
1575   png_charp end, int format, png_alloc_size_t number),PNG_EMPTY);
1576
1577/* Convenience macro that takes an array: */
1578#define PNG_FORMAT_NUMBER(buffer,format,number) \
1579   png_format_number(buffer, buffer + (sizeof buffer), format, number)
1580
1581/* Suggested size for a number buffer (enough for 64 bits and a sign!) */
1582#define PNG_NUMBER_BUFFER_SIZE 24
1583
1584/* These are the integer formats currently supported, the name is formed from
1585 * the standard printf(3) format string.
1586 */
1587#define PNG_NUMBER_FORMAT_u     1 /* chose unsigned API! */
1588#define PNG_NUMBER_FORMAT_02u   2
1589#define PNG_NUMBER_FORMAT_d     1 /* chose signed API! */
1590#define PNG_NUMBER_FORMAT_02d   2
1591#define PNG_NUMBER_FORMAT_x     3
1592#define PNG_NUMBER_FORMAT_02x   4
1593#define PNG_NUMBER_FORMAT_fixed 5 /* choose the signed API */
1594#endif
1595
1596#ifdef PNG_WARNINGS_SUPPORTED
1597/* New defines and members adding in libpng-1.5.4 */
1598#  define PNG_WARNING_PARAMETER_SIZE 32
1599#  define PNG_WARNING_PARAMETER_COUNT 8 /* Maximum 9; see pngerror.c */
1600
1601/* An l-value of this type has to be passed to the APIs below to cache the
1602 * values of the parameters to a formatted warning message.
1603 */
1604typedef char png_warning_parameters[PNG_WARNING_PARAMETER_COUNT][
1605   PNG_WARNING_PARAMETER_SIZE];
1606
1607PNG_INTERNAL_FUNCTION(void,png_warning_parameter,(png_warning_parameters p,
1608   int number, png_const_charp string),PNG_EMPTY);
1609   /* Parameters are limited in size to PNG_WARNING_PARAMETER_SIZE characters,
1610    * including the trailing '\0'.
1611    */
1612PNG_INTERNAL_FUNCTION(void,png_warning_parameter_unsigned,
1613   (png_warning_parameters p, int number, int format, png_alloc_size_t value),
1614   PNG_EMPTY);
1615   /* Use png_alloc_size_t because it is an unsigned type as big as any we
1616    * need to output.  Use the following for a signed value.
1617    */
1618PNG_INTERNAL_FUNCTION(void,png_warning_parameter_signed,
1619   (png_warning_parameters p, int number, int format, png_int_32 value),
1620   PNG_EMPTY);
1621
1622PNG_INTERNAL_FUNCTION(void,png_formatted_warning,(png_const_structrp png_ptr,
1623   png_warning_parameters p, png_const_charp message),PNG_EMPTY);
1624   /* 'message' follows the X/Open approach of using @1, @2 to insert
1625    * parameters previously supplied using the above functions.  Errors in
1626    * specifying the parameters will simply result in garbage substitutions.
1627    */
1628#endif
1629
1630#ifdef PNG_BENIGN_ERRORS_SUPPORTED
1631/* Application errors (new in 1.6); use these functions (declared below) for
1632 * errors in the parameters or order of API function calls on read.  The
1633 * 'warning' should be used for an error that can be handled completely; the
1634 * 'error' for one which can be handled safely but which may lose application
1635 * information or settings.
1636 *
1637 * By default these both result in a png_error call prior to release, while in a
1638 * released version the 'warning' is just a warning.  However if the application
1639 * explicitly disables benign errors (explicitly permitting the code to lose
1640 * information) they both turn into warnings.
1641 *
1642 * If benign errors aren't supported they end up as the corresponding base call
1643 * (png_warning or png_error.)
1644 */
1645PNG_INTERNAL_FUNCTION(void,png_app_warning,(png_const_structrp png_ptr,
1646   png_const_charp message),PNG_EMPTY);
1647   /* The application provided invalid parameters to an API function or called
1648    * an API function at the wrong time, libpng can completely recover.
1649    */
1650
1651PNG_INTERNAL_FUNCTION(void,png_app_error,(png_const_structrp png_ptr,
1652   png_const_charp message),PNG_EMPTY);
1653   /* As above but libpng will ignore the call, or attempt some other partial
1654    * recovery from the error.
1655    */
1656#else
1657#  define png_app_warning(pp,s) png_warning(pp,s)
1658#  define png_app_error(pp,s) png_error(pp,s)
1659#endif
1660
1661PNG_INTERNAL_FUNCTION(void,png_chunk_report,(png_const_structrp png_ptr,
1662   png_const_charp message, int error),PNG_EMPTY);
1663   /* Report a recoverable issue in chunk data.  On read this is used to report
1664    * a problem found while reading a particular chunk and the
1665    * png_chunk_benign_error or png_chunk_warning function is used as
1666    * appropriate.  On write this is used to report an error that comes from
1667    * data set via an application call to a png_set_ API and png_app_error or
1668    * png_app_warning is used as appropriate.
1669    *
1670    * The 'error' parameter must have one of the following values:
1671    */
1672#define PNG_CHUNK_WARNING     0 /* never an error */
1673#define PNG_CHUNK_WRITE_ERROR 1 /* an error only on write */
1674#define PNG_CHUNK_ERROR       2 /* always an error */
1675
1676/* ASCII to FP interfaces, currently only implemented if sCAL
1677 * support is required.
1678 */
1679#if defined(PNG_sCAL_SUPPORTED)
1680/* MAX_DIGITS is actually the maximum number of characters in an sCAL
1681 * width or height, derived from the precision (number of significant
1682 * digits - a build time settable option) and assumptions about the
1683 * maximum ridiculous exponent.
1684 */
1685#define PNG_sCAL_MAX_DIGITS (PNG_sCAL_PRECISION+1/*.*/+1/*E*/+10/*exponent*/)
1686
1687#ifdef PNG_FLOATING_POINT_SUPPORTED
1688PNG_INTERNAL_FUNCTION(void,png_ascii_from_fp,(png_const_structrp png_ptr,
1689   png_charp ascii, png_size_t size, double fp, unsigned int precision),
1690   PNG_EMPTY);
1691#endif /* FLOATING_POINT */
1692
1693#ifdef PNG_FIXED_POINT_SUPPORTED
1694PNG_INTERNAL_FUNCTION(void,png_ascii_from_fixed,(png_const_structrp png_ptr,
1695   png_charp ascii, png_size_t size, png_fixed_point fp),PNG_EMPTY);
1696#endif /* FIXED_POINT */
1697#endif /* sCAL */
1698
1699#if defined(PNG_sCAL_SUPPORTED) || defined(PNG_pCAL_SUPPORTED)
1700/* An internal API to validate the format of a floating point number.
1701 * The result is the index of the next character.  If the number is
1702 * not valid it will be the index of a character in the supposed number.
1703 *
1704 * The format of a number is defined in the PNG extensions specification
1705 * and this API is strictly conformant to that spec, not anyone elses!
1706 *
1707 * The format as a regular expression is:
1708 *
1709 * [+-]?[0-9]+.?([Ee][+-]?[0-9]+)?
1710 *
1711 * or:
1712 *
1713 * [+-]?.[0-9]+(.[0-9]+)?([Ee][+-]?[0-9]+)?
1714 *
1715 * The complexity is that either integer or fraction must be present and the
1716 * fraction is permitted to have no digits only if the integer is present.
1717 *
1718 * NOTE: The dangling E problem.
1719 *   There is a PNG valid floating point number in the following:
1720 *
1721 *       PNG floating point numbers are not greedy.
1722 *
1723 *   Working this out requires *TWO* character lookahead (because of the
1724 *   sign), the parser does not do this - it will fail at the 'r' - this
1725 *   doesn't matter for PNG sCAL chunk values, but it requires more care
1726 *   if the value were ever to be embedded in something more complex.  Use
1727 *   ANSI-C strtod if you need the lookahead.
1728 */
1729/* State table for the parser. */
1730#define PNG_FP_INTEGER    0  /* before or in integer */
1731#define PNG_FP_FRACTION   1  /* before or in fraction */
1732#define PNG_FP_EXPONENT   2  /* before or in exponent */
1733#define PNG_FP_STATE      3  /* mask for the above */
1734#define PNG_FP_SAW_SIGN   4  /* Saw +/- in current state */
1735#define PNG_FP_SAW_DIGIT  8  /* Saw a digit in current state */
1736#define PNG_FP_SAW_DOT   16  /* Saw a dot in current state */
1737#define PNG_FP_SAW_E     32  /* Saw an E (or e) in current state */
1738#define PNG_FP_SAW_ANY   60  /* Saw any of the above 4 */
1739
1740/* These three values don't affect the parser.  They are set but not used.
1741 */
1742#define PNG_FP_WAS_VALID 64  /* Preceding substring is a valid fp number */
1743#define PNG_FP_NEGATIVE 128  /* A negative number, including "-0" */
1744#define PNG_FP_NONZERO  256  /* A non-zero value */
1745#define PNG_FP_STICKY   448  /* The above three flags */
1746
1747/* This is available for the caller to store in 'state' if required.  Do not
1748 * call the parser after setting it (the parser sometimes clears it.)
1749 */
1750#define PNG_FP_INVALID  512  /* Available for callers as a distinct value */
1751
1752/* Result codes for the parser (boolean - true meants ok, false means
1753 * not ok yet.)
1754 */
1755#define PNG_FP_MAYBE      0  /* The number may be valid in the future */
1756#define PNG_FP_OK         1  /* The number is valid */
1757
1758/* Tests on the sticky non-zero and negative flags.  To pass these checks
1759 * the state must also indicate that the whole number is valid - this is
1760 * achieved by testing PNG_FP_SAW_DIGIT (see the implementation for why this
1761 * is equivalent to PNG_FP_OK above.)
1762 */
1763#define PNG_FP_NZ_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NEGATIVE | PNG_FP_NONZERO)
1764   /* NZ_MASK: the string is valid and a non-zero negative value */
1765#define PNG_FP_Z_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NONZERO)
1766   /* Z MASK: the string is valid and a non-zero value. */
1767   /* PNG_FP_SAW_DIGIT: the string is valid. */
1768#define PNG_FP_IS_ZERO(state) (((state) & PNG_FP_Z_MASK) == PNG_FP_SAW_DIGIT)
1769#define PNG_FP_IS_POSITIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_Z_MASK)
1770#define PNG_FP_IS_NEGATIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_NZ_MASK)
1771
1772/* The actual parser.  This can be called repeatedly. It updates
1773 * the index into the string and the state variable (which must
1774 * be initialized to 0).  It returns a result code, as above.  There
1775 * is no point calling the parser any more if it fails to advance to
1776 * the end of the string - it is stuck on an invalid character (or
1777 * terminated by '\0').
1778 *
1779 * Note that the pointer will consume an E or even an E+ and then leave
1780 * a 'maybe' state even though a preceding integer.fraction is valid.
1781 * The PNG_FP_WAS_VALID flag indicates that a preceding substring was
1782 * a valid number.  It's possible to recover from this by calling
1783 * the parser again (from the start, with state 0) but with a string
1784 * that omits the last character (i.e. set the size to the index of
1785 * the problem character.)  This has not been tested within libpng.
1786 */
1787PNG_INTERNAL_FUNCTION(int,png_check_fp_number,(png_const_charp string,
1788   png_size_t size, int *statep, png_size_tp whereami),PNG_EMPTY);
1789
1790/* This is the same but it checks a complete string and returns true
1791 * only if it just contains a floating point number.  As of 1.5.4 this
1792 * function also returns the state at the end of parsing the number if
1793 * it was valid (otherwise it returns 0.)  This can be used for testing
1794 * for negative or zero values using the sticky flag.
1795 */
1796PNG_INTERNAL_FUNCTION(int,png_check_fp_string,(png_const_charp string,
1797   png_size_t size),PNG_EMPTY);
1798#endif /* pCAL || sCAL */
1799
1800#if defined(PNG_GAMMA_SUPPORTED) ||\
1801    defined(PNG_INCH_CONVERSIONS_SUPPORTED) || defined(PNG_READ_pHYs_SUPPORTED)
1802/* Added at libpng version 1.5.0 */
1803/* This is a utility to provide a*times/div (rounded) and indicate
1804 * if there is an overflow.  The result is a boolean - false (0)
1805 * for overflow, true (1) if no overflow, in which case *res
1806 * holds the result.
1807 */
1808PNG_INTERNAL_FUNCTION(int,png_muldiv,(png_fixed_point_p res, png_fixed_point a,
1809   png_int_32 multiplied_by, png_int_32 divided_by),PNG_EMPTY);
1810#endif
1811
1812#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_INCH_CONVERSIONS_SUPPORTED)
1813/* Same deal, but issue a warning on overflow and return 0. */
1814PNG_INTERNAL_FUNCTION(png_fixed_point,png_muldiv_warn,
1815   (png_const_structrp png_ptr, png_fixed_point a, png_int_32 multiplied_by,
1816   png_int_32 divided_by),PNG_EMPTY);
1817#endif
1818
1819#ifdef PNG_GAMMA_SUPPORTED
1820/* Calculate a reciprocal - used for gamma values.  This returns
1821 * 0 if the argument is 0 in order to maintain an undefined value;
1822 * there are no warnings.
1823 */
1824PNG_INTERNAL_FUNCTION(png_fixed_point,png_reciprocal,(png_fixed_point a),
1825   PNG_EMPTY);
1826
1827#ifdef PNG_READ_GAMMA_SUPPORTED
1828/* The same but gives a reciprocal of the product of two fixed point
1829 * values.  Accuracy is suitable for gamma calculations but this is
1830 * not exact - use png_muldiv for that.  Only required at present on read.
1831 */
1832PNG_INTERNAL_FUNCTION(png_fixed_point,png_reciprocal2,(png_fixed_point a,
1833   png_fixed_point b),PNG_EMPTY);
1834#endif
1835
1836/* Return true if the gamma value is significantly different from 1.0 */
1837PNG_INTERNAL_FUNCTION(int,png_gamma_significant,(png_fixed_point gamma_value),
1838   PNG_EMPTY);
1839#endif
1840
1841#ifdef PNG_READ_GAMMA_SUPPORTED
1842/* Internal fixed point gamma correction.  These APIs are called as
1843 * required to convert single values - they don't need to be fast,
1844 * they are not used when processing image pixel values.
1845 *
1846 * While the input is an 'unsigned' value it must actually be the
1847 * correct bit value - 0..255 or 0..65535 as required.
1848 */
1849PNG_INTERNAL_FUNCTION(png_uint_16,png_gamma_correct,(png_structrp png_ptr,
1850   unsigned int value, png_fixed_point gamma_value),PNG_EMPTY);
1851PNG_INTERNAL_FUNCTION(png_uint_16,png_gamma_16bit_correct,(unsigned int value,
1852   png_fixed_point gamma_value),PNG_EMPTY);
1853PNG_INTERNAL_FUNCTION(png_byte,png_gamma_8bit_correct,(unsigned int value,
1854   png_fixed_point gamma_value),PNG_EMPTY);
1855PNG_INTERNAL_FUNCTION(void,png_destroy_gamma_table,(png_structrp png_ptr),
1856   PNG_EMPTY);
1857PNG_INTERNAL_FUNCTION(void,png_build_gamma_table,(png_structrp png_ptr,
1858   int bit_depth),PNG_EMPTY);
1859#endif
1860
1861/* SIMPLIFIED READ/WRITE SUPPORT */
1862#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
1863   defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
1864/* The internal structure that png_image::opaque points to. */
1865typedef struct png_control
1866{
1867   png_structp png_ptr;
1868   png_infop   info_ptr;
1869   png_voidp   error_buf;           /* Always a jmp_buf at present. */
1870
1871   png_const_bytep memory;          /* Memory buffer. */
1872   png_size_t      size;            /* Size of the memory buffer. */
1873
1874   unsigned int for_write       :1; /* Otherwise it is a read structure */
1875   unsigned int owned_file      :1; /* We own the file in io_ptr */
1876} png_control;
1877
1878/* Return the pointer to the jmp_buf from a png_control: necessary because C
1879 * does not reveal the type of the elements of jmp_buf.
1880 */
1881#ifdef __cplusplus
1882#  define png_control_jmp_buf(pc) (((jmp_buf*)((pc)->error_buf))[0])
1883#else
1884#  define png_control_jmp_buf(pc) ((pc)->error_buf)
1885#endif
1886
1887/* Utility to safely execute a piece of libpng code catching and logging any
1888 * errors that might occur.  Returns true on success, false on failure (either
1889 * of the function or as a result of a png_error.)
1890 */
1891PNG_INTERNAL_CALLBACK(void,png_safe_error,(png_structp png_ptr,
1892   png_const_charp error_message),PNG_NORETURN);
1893
1894#ifdef PNG_WARNINGS_SUPPORTED
1895PNG_INTERNAL_CALLBACK(void,png_safe_warning,(png_structp png_ptr,
1896   png_const_charp warning_message),PNG_EMPTY);
1897#else
1898#  define png_safe_warning 0/*dummy argument*/
1899#endif
1900
1901PNG_INTERNAL_FUNCTION(int,png_safe_execute,(png_imagep image,
1902   int (*function)(png_voidp), png_voidp arg),PNG_EMPTY);
1903
1904/* Utility to log an error; this also cleans up the png_image; the function
1905 * always returns 0 (false).
1906 */
1907PNG_INTERNAL_FUNCTION(int,png_image_error,(png_imagep image,
1908   png_const_charp error_message),PNG_EMPTY);
1909
1910#ifndef PNG_SIMPLIFIED_READ_SUPPORTED
1911/* png_image_free is used by the write code but not exported */
1912PNG_INTERNAL_FUNCTION(void, png_image_free, (png_imagep image), PNG_EMPTY);
1913#endif /* !SIMPLIFIED_READ */
1914
1915#endif /* SIMPLIFIED READ/WRITE */
1916
1917/* These are initialization functions for hardware specific PNG filter
1918 * optimizations; list these here then select the appropriate one at compile
1919 * time using the macro PNG_FILTER_OPTIMIZATIONS.  If the macro is not defined
1920 * the generic code is used.
1921 */
1922#ifdef PNG_FILTER_OPTIMIZATIONS
1923PNG_INTERNAL_FUNCTION(void, PNG_FILTER_OPTIMIZATIONS, (png_structp png_ptr,
1924   unsigned int bpp), PNG_EMPTY);
1925   /* Just declare the optimization that will be used */
1926#else
1927   /* List *all* the possible optimizations here - this branch is required if
1928    * the builder of libpng passes the definition of PNG_FILTER_OPTIMIZATIONS in
1929    * CFLAGS in place of CPPFLAGS *and* uses symbol prefixing.
1930    */
1931PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_neon,
1932   (png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
1933#endif
1934
1935#ifdef PNG_INDEX_SUPPORTED
1936PNG_INTERNAL_FUNCTION(void, png_seek_data, (png_structp png_ptr,
1937   png_uint_32 length), PNG_EMPTY);
1938PNG_INTERNAL_FUNCTION(int, png_opt_crc_finish,(png_structrp png_ptr,
1939   png_uint_32 skip), PNG_EMPTY);
1940PNG_INTERNAL_FUNCTION(void, png_set_interlaced_pass,(png_structrp png_ptr,
1941   int pass), PNG_EMPTY);
1942#endif
1943
1944/* Maintainer: Put new private prototypes here ^ */
1945
1946#include "pngdebug.h"
1947
1948#ifdef __cplusplus
1949}
1950#endif
1951
1952#endif /* PNG_VERSION_INFO_ONLY */
1953#endif /* PNGPRIV_H */
1954