• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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   */
179  typedef 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
620  PNG_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
698  extern "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   */
710  PNG_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 */
714  PNG_EXTERN PNG_FUNCTION(png_voidp,png_create_struct,PNGARG((int type)),
715     PNG_ALLOCATED);
716  
717  /* Free memory from internal libpng struct */
718  PNG_EXTERN void png_destroy_struct PNGARG((png_voidp struct_ptr));
719  
720  PNG_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);
723  PNG_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. */
727  PNG_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. */
731  PNG_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. */
735  PNG_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  
742  PNG_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
746  PNG_EXTERN void PNGCBAPI png_push_fill_buffer PNGARG((png_structp png_ptr,
747      png_bytep buffer, png_size_t length));
748  #endif
749  
750  PNG_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
755  PNG_EXTERN void PNGCBAPI png_default_flush PNGARG((png_structp png_ptr));
756  #  endif
757  #endif
758  
759  /* Reset the CRC variable */
760  PNG_EXTERN void png_reset_crc PNGARG((png_structp png_ptr));
761  
762  /* Write the "data" buffer to whatever output you are using */
763  PNG_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 */
767  PNG_EXTERN void png_read_sig PNGARG((png_structp png_ptr, png_infop info_ptr));
768  
769  /* Read the chunk header (length + type name) */
770  PNG_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 */
773  PNG_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 */
777  PNG_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)
782  PNG_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 */
788  PNG_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 */
791  PNG_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   */
797  PNG_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
801  PNG_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   */
809  PNG_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  
814  PNG_EXTERN void png_write_PLTE PNGARG((png_structp png_ptr,
815      png_const_colorp palette, png_uint_32 num_pal));
816  
817  PNG_EXTERN void png_write_IDAT PNGARG((png_structp png_ptr, png_bytep data,
818      png_size_t length));
819  
820  PNG_EXTERN void png_write_IEND PNGARG((png_structp png_ptr));
821  
822  #ifdef PNG_WRITE_gAMA_SUPPORTED
823  #  ifdef PNG_FLOATING_POINT_SUPPORTED
824  PNG_EXTERN void png_write_gAMA PNGARG((png_structp png_ptr, double file_gamma));
825  #  endif
826  #  ifdef PNG_FIXED_POINT_SUPPORTED
827  PNG_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
833  PNG_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
839  PNG_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
844  PNG_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
852  PNG_EXTERN void png_write_sRGB PNGARG((png_structp png_ptr,
853      int intent));
854  #endif
855  
856  #ifdef PNG_WRITE_iCCP_SUPPORTED
857  PNG_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
864  PNG_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
869  PNG_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
875  PNG_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
880  PNG_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)
887  PNG_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
892  PNG_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
897  PNG_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
902  PNG_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 */
908  PNG_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
913  PNG_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
918  PNG_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
924  PNG_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
930  PNG_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
935  PNG_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 */
940  PNG_EXTERN void png_write_finish_row PNGARG((png_structp png_ptr));
941  
942  /* Internal use only.   Called before first row of data */
943  PNG_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
971  PNG_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   */
981  PNG_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 */
989  PNG_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   */
996  PNG_EXTERN void png_read_filter_row PNGARG((png_structp pp, png_row_infop
997      row_info, png_bytep row, png_const_bytep prev_row, int filter));
998  
999  PNG_EXTERN void png_read_filter_row_up_neon PNGARG((png_row_infop row_info,
1000      png_bytep row, png_const_bytep prev_row));
1001  PNG_EXTERN void png_read_filter_row_sub3_neon PNGARG((png_row_infop row_info,
1002      png_bytep row, png_const_bytep prev_row));
1003  PNG_EXTERN void png_read_filter_row_sub4_neon PNGARG((png_row_infop row_info,
1004      png_bytep row, png_const_bytep prev_row));
1005  PNG_EXTERN void png_read_filter_row_avg3_neon PNGARG((png_row_infop row_info,
1006      png_bytep row, png_const_bytep prev_row));
1007  PNG_EXTERN void png_read_filter_row_avg4_neon PNGARG((png_row_infop row_info,
1008      png_bytep row, png_const_bytep prev_row));
1009  PNG_EXTERN void png_read_filter_row_paeth3_neon PNGARG((png_row_infop row_info,
1010      png_bytep row, png_const_bytep prev_row));
1011  PNG_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 */
1015  PNG_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. */
1019  PNG_EXTERN void png_read_finish_row PNGARG((png_structp png_ptr));
1020  
1021  /* Initialize the row buffers, etc. */
1022  PNG_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 */
1026  PNG_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
1032  PNG_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
1037  PNG_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
1042  PNG_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
1047  PNG_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
1052  PNG_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)
1058  PNG_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)
1064  PNG_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)
1071  PNG_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
1076  PNG_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
1081  PNG_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
1086  PNG_EXTERN void png_do_unpack PNGARG((png_row_infop row_info,
1087      png_bytep row));
1088  #endif
1089  
1090  #ifdef PNG_READ_SHIFT_SUPPORTED
1091  PNG_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)
1096  PNG_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
1101  PNG_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
1106  PNG_EXTERN void png_do_chop PNGARG((png_row_infop row_info,
1107      png_bytep row));
1108  #endif
1109  
1110  #ifdef PNG_READ_QUANTIZE_SUPPORTED
1111  PNG_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
1116  PNG_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)
1122  PNG_EXTERN void png_do_bgr PNGARG((png_row_infop row_info,
1123      png_bytep row));
1124  #endif
1125  
1126  #ifdef PNG_WRITE_PACK_SUPPORTED
1127  PNG_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
1132  PNG_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)
1138  PNG_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
1143  PNG_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
1148  PNG_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
1153  PNG_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));
1156  PNG_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
1161  PNG_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 */
1170  PNG_EXTERN void png_handle_IHDR PNGARG((png_structp png_ptr, png_infop info_ptr,
1171      png_uint_32 length));
1172  PNG_EXTERN void png_handle_PLTE PNGARG((png_structp png_ptr, png_infop info_ptr,
1173      png_uint_32 length));
1174  PNG_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
1178  PNG_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
1183  PNG_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
1188  PNG_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
1193  PNG_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
1198  PNG_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
1203  PNG_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
1208  PNG_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
1213  PNG_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
1218  PNG_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
1223  PNG_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
1228  PNG_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
1233  PNG_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
1238  PNG_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
1243  PNG_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
1248  PNG_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
1253  PNG_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
1258  PNG_EXTERN void png_handle_zTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
1259      png_uint_32 length));
1260  #endif
1261  
1262  PNG_EXTERN void png_handle_unknown PNGARG((png_structp png_ptr,
1263      png_infop info_ptr, png_uint_32 length));
1264  
1265  PNG_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   */
1272  PNG_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
1278  PNG_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
1282  PNG_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
1287  PNG_EXTERN void png_init_read_transformations PNGARG((png_structp png_ptr));
1288  #endif
1289  
1290  #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1291  PNG_EXTERN void png_push_read_chunk PNGARG((png_structp png_ptr,
1292      png_infop info_ptr));
1293  PNG_EXTERN void png_push_read_sig PNGARG((png_structp png_ptr,
1294      png_infop info_ptr));
1295  PNG_EXTERN void png_push_check_crc PNGARG((png_structp png_ptr));
1296  PNG_EXTERN void png_push_crc_skip PNGARG((png_structp png_ptr,
1297      png_uint_32 length));
1298  PNG_EXTERN void png_push_crc_finish PNGARG((png_structp png_ptr));
1299  PNG_EXTERN void png_push_save_buffer PNGARG((png_structp png_ptr));
1300  PNG_EXTERN void png_push_restore_buffer PNGARG((png_structp png_ptr,
1301      png_bytep buffer, png_size_t buffer_length));
1302  PNG_EXTERN void png_push_read_IDAT PNGARG((png_structp png_ptr));
1303  PNG_EXTERN void png_process_IDAT_data PNGARG((png_structp png_ptr,
1304      png_bytep buffer, png_size_t buffer_length));
1305  PNG_EXTERN void png_push_process_row PNGARG((png_structp png_ptr));
1306  PNG_EXTERN void png_push_handle_unknown PNGARG((png_structp png_ptr,
1307     png_infop info_ptr, png_uint_32 length));
1308  PNG_EXTERN void png_push_have_info PNGARG((png_structp png_ptr,
1309     png_infop info_ptr));
1310  PNG_EXTERN void png_push_have_end PNGARG((png_structp png_ptr,
1311     png_infop info_ptr));
1312  PNG_EXTERN void png_push_have_row PNGARG((png_structp png_ptr, png_bytep row));
1313  PNG_EXTERN void png_push_read_end PNGARG((png_structp png_ptr,
1314      png_infop info_ptr));
1315  PNG_EXTERN void png_process_some_data PNGARG((png_structp png_ptr,
1316      png_infop info_ptr));
1317  PNG_EXTERN void png_read_push_finish_row PNGARG((png_structp png_ptr));
1318  #  ifdef PNG_READ_tEXt_SUPPORTED
1319  PNG_EXTERN void png_push_handle_tEXt PNGARG((png_structp png_ptr,
1320      png_infop info_ptr, png_uint_32 length));
1321  PNG_EXTERN void png_push_read_tEXt PNGARG((png_structp png_ptr,
1322      png_infop info_ptr));
1323  #  endif
1324  #  ifdef PNG_READ_zTXt_SUPPORTED
1325  PNG_EXTERN void png_push_handle_zTXt PNGARG((png_structp png_ptr,
1326      png_infop info_ptr, png_uint_32 length));
1327  PNG_EXTERN void png_push_read_zTXt PNGARG((png_structp png_ptr,
1328      png_infop info_ptr));
1329  #  endif
1330  #  ifdef PNG_READ_iTXt_SUPPORTED
1331  PNG_EXTERN void png_push_handle_iTXt PNGARG((png_structp png_ptr,
1332      png_infop info_ptr, png_uint_32 length));
1333  PNG_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
1340  PNG_EXTERN void png_do_read_intrapixel PNGARG((png_row_infop row_info,
1341      png_bytep row));
1342  PNG_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
1348  PNG_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 */
1358  PNG_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 */
1364  typedef 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  
1372  typedef 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   */
1385  PNG_EXTERN int png_xy_from_XYZ PNGARG((png_xy *xy, png_XYZ XYZ));
1386  PNG_EXTERN int png_XYZ_from_xy PNGARG((png_XYZ *XYZ, png_xy xy));
1387  PNG_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 */
1392  PNG_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)
1400  PNG_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) */
1405  PNG_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) */
1409  PNG_EXTERN void png_write_destroy PNGARG((png_structp png_ptr));
1410  
1411  #ifdef USE_FAR_KEYWORD  /* memory model conversion function */
1412  PNG_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)
1417  PNG_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   */
1425  PNG_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   */
1437  PNG_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   */
1467  typedef char png_warning_parameters[PNG_WARNING_PARAMETER_COUNT][
1468     PNG_WARNING_PARAMETER_SIZE];
1469  
1470  PNG_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       */
1475  PNG_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       */
1480  PNG_EXTERN void png_warning_parameter_signed(png_warning_parameters p,
1481      int number, int format, png_int_32 value);
1482  
1483  PNG_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
1503  PNG_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
1508  PNG_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   */
1601  PNG_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   */
1610  PNG_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   */
1622  PNG_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. */
1628  PNG_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   */
1637  PNG_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   */
1643  PNG_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   */
1655  PNG_EXTERN png_uint_16 png_gamma_correct PNGARG((png_structp png_ptr,
1656      unsigned int value, png_fixed_point gamma_value));
1657  PNG_EXTERN int png_gamma_significant PNGARG((png_fixed_point gamma_value));
1658  PNG_EXTERN png_uint_16 png_gamma_16bit_correct PNGARG((unsigned int value,
1659      png_fixed_point gamma_value));
1660  PNG_EXTERN png_byte png_gamma_8bit_correct PNGARG((unsigned int value,
1661      png_fixed_point gamma_value));
1662  PNG_EXTERN void png_destroy_gamma_table(png_structp png_ptr);
1663  PNG_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 */
1676