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/* pngpriv.h - private declarations for use inside libpng
* * For conditions of distribution and use, see copyright notice in png.h * Copyright (c) 1998-2011 Glenn Randers-Pehrson * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) * * Last changed in libpng 1.5.2 [March 31, 2011] * * This code is released under the libpng license. * For conditions of distribution and use, see the disclaimer * and license in png.h */
/* The symbols declared in this file (including the functions declared
* as PNG_EXTERN) are PRIVATE. They are not part of the libpng public * interface, and are not recommended for use by regular applications. * Some of them may become public in the future; others may stay private, * change in an incompatible way, or even disappear. * Although the libpng users are not forbidden to include this header, * they should be well aware of the issues that may arise from doing so. */
#ifndef PNGPRIV_H
#define PNGPRIV_H
/* This is required for the definition of abort(), used as a last ditch
* error handler when all else fails. */#include <stdlib.h>
#define PNGLIB_BUILD
#ifdef PNG_USER_CONFIG
# include "pngusr.h"
/* These should have been defined in pngusr.h */# ifndef PNG_USER_PRIVATEBUILD
# define PNG_USER_PRIVATEBUILD "Custom libpng build"
# endif
# ifndef PNG_USER_DLLFNAME_POSTFIX
# define PNG_USER_DLLFNAME_POSTFIX "Cb"
# endif
#endif
#include "png.h"
#include "pnginfo.h"
#include "pngstruct.h"
/* This is used for 16 bit gamma tables - only the top level pointers are const,
* this could be changed: */typedef PNG_CONST png_uint_16p FAR * png_const_uint_16pp;
/* Added at libpng-1.2.9 *//* Moved to pngpriv.h at libpng-1.5.0 */
/* config.h is created by and PNG_CONFIGURE_LIBPNG is set by the "configure"
* script. We may need it here to get the correct configuration on things * like limits. */#ifdef PNG_CONFIGURE_LIBPNG
# ifdef HAVE_CONFIG_H
# include "config.h"
# endif
#endif
/* Moved to pngpriv.h at libpng-1.5.0 *//* NOTE: some of these may have been used in external applications as
* these definitions were exposed in pngconf.h prior to 1.5. */
/* If you are running on a machine where you cannot allocate more
* than 64K of memory at once, uncomment this. While libpng will not * normally need that much memory in a chunk (unless you load up a very * large file), zlib needs to know how big of a chunk it can use, and * libpng thus makes sure to check any memory allocation to verify it * will fit into memory. * * zlib provides 'MAXSEG_64K' which, if defined, indicates the * same limit and pngconf.h (already included) sets the limit * if certain operating systems are detected. */#if defined(MAXSEG_64K) && !defined(PNG_MAX_MALLOC_64K)
# define PNG_MAX_MALLOC_64K
#endif
#ifndef PNG_UNUSED
/* Unused formal parameter warnings are silenced using the following macro
* which is expected to have no bad effects on performance (optimizing * compilers will probably remove it entirely). Note that if you replace * it with something other than whitespace, you must include the terminating * semicolon. */# define PNG_UNUSED(param) (void)param;
#endif
/* Just a little check that someone hasn't tried to define something
* contradictory. */#if (PNG_ZBUF_SIZE > 65536L) && defined(PNG_MAX_MALLOC_64K)
# undef PNG_ZBUF_SIZE
# define PNG_ZBUF_SIZE 65536L
#endif
/* If warnings or errors are turned off the code is disabled
* or redirected here. */#ifndef PNG_WARNINGS_SUPPORTED
# define png_warning(s1,s2) ((void)0)
# define png_chunk_warning(s1,s2) ((void)0)
#endif
#ifndef PNG_ERROR_TEXT_SUPPORTED
# define png_error(s1,s2) png_err(s1)
# define png_chunk_error(s1,s2) png_err(s1)
# define png_fixed_error(s1,s2) png_err(s1)
#endif
#ifndef PNG_EXTERN
/* The functions exported by PNG_EXTERN are internal functions, which
* aren't usually used outside the library (as far as I know), so it is * debatable if they should be exported at all. In the future, when it * is possible to have run-time registry of chunk-handling functions, * some of these might be made available again.# define PNG_EXTERN extern
*/# define PNG_EXTERN
#endif
/* Some fixed point APIs are still required even if not exported because
* they get used by the corresponding floating point APIs. This magic * deals with this: */#ifdef PNG_FIXED_POINT_SUPPORTED
# define PNGFAPI PNGAPI
#else
# define PNGFAPI /* PRIVATE */
#endif
/* Other defines specific to compilers can go here. Try to keep
* them inside an appropriate ifdef/endif pair for portability. */#if defined(PNG_FLOATING_POINT_SUPPORTED) ||\
defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) /* png.c requires the following ANSI-C constants if the conversion of
* floating point to ASCII is implemented therein: * * DBL_DIG Maximum number of decimal digits (can be set to any constant) * DBL_MIN Smallest normalized fp number (can be set to an arbitrary value) * DBL_MAX Maximum floating point number (can be set to an arbitrary value) */# include <float.h>
# if (defined(__MWERKS__) && defined(macintosh)) || defined(applec) || \
defined(THINK_C) || defined(__SC__) || defined(TARGET_OS_MAC) /* We need to check that <math.h> hasn't already been included earlier
* as it seems it doesn't agree with <fp.h>, yet we should really use * <fp.h> if possible. */# if !defined(__MATH_H__) && !defined(__MATH_H) && !defined(__cmath__)
# include <fp.h>
# endif
# else
# include <math.h>
# endif
# if defined(_AMIGA) && defined(__SASC) && defined(_M68881)
/* Amiga SAS/C: We must include builtin FPU functions when compiling using
* MATH=68881 */# include <m68881.h>
# endif
#endif
/* This provides the non-ANSI (far) memory allocation routines. */#if defined(__TURBOC__) && defined(__MSDOS__)
# include <mem.h>
# include <alloc.h>
#endif
#if defined(WIN32) || defined(_Windows) || defined(_WINDOWS) || \
defined(_WIN32) || defined(__WIN32__)# include <windows.h> /* defines _WINDOWS_ macro */
#endif
/* Moved here around 1.5.0beta36 from pngconf.h *//* Users may want to use these so they are not private. Any library
* functions that are passed far data must be model-independent. */
/* Memory model/platform independent fns */#ifndef PNG_ABORT
# ifdef _WINDOWS_
# define PNG_ABORT() ExitProcess(0)
# else
# define PNG_ABORT() abort()
# endif
#endif
#ifdef USE_FAR_KEYWORD
/* Use this to make far-to-near assignments */# define CHECK 1
# define NOCHECK 0
# define CVT_PTR(ptr) (png_far_to_near(png_ptr,ptr,CHECK))
# define CVT_PTR_NOCHECK(ptr) (png_far_to_near(png_ptr,ptr,NOCHECK))
# define png_strcpy _fstrcpy
# define png_strncpy _fstrncpy /* Added to v 1.2.6 */
# define png_strlen _fstrlen
# define png_memcmp _fmemcmp /* SJT: added */
# define png_memcpy _fmemcpy
# define png_memset _fmemset
# define png_sprintf sprintf
#else
# ifdef _WINDOWS_ /* Favor Windows over C runtime fns */
# define CVT_PTR(ptr) (ptr)
# define CVT_PTR_NOCHECK(ptr) (ptr)
# define png_strcpy lstrcpyA
# define png_strncpy lstrcpynA
# define png_strlen lstrlenA
# define png_memcmp memcmp
# define png_memcpy CopyMemory
# define png_memset memset
# define png_sprintf wsprintfA
# else
# define CVT_PTR(ptr) (ptr)
# define CVT_PTR_NOCHECK(ptr) (ptr)
# define png_strcpy strcpy
# define png_strncpy strncpy /* Added to v 1.2.6 */
# define png_strlen strlen
# define png_memcmp memcmp /* SJT: added */
# define png_memcpy memcpy
# define png_memset memset
# define png_sprintf sprintf
# endif
#endif
/* End of memory model/platform independent support */
#ifndef PNG_NO_SNPRINTF
# ifdef _MSC_VER
# define png_snprintf _snprintf /* Added to v 1.2.19 */
# define png_snprintf2 _snprintf
# define png_snprintf6 _snprintf
# else
# define png_snprintf snprintf /* Added to v 1.2.19 */
# define png_snprintf2 snprintf
# define png_snprintf6 snprintf
# endif
#else
/* You don't have or don't want to use snprintf(). Caution: Using
* sprintf instead of snprintf exposes your application to accidental * or malevolent buffer overflows. If you don't have snprintf() * as a general rule you should provide one (you can get one from * Portable OpenSSH). */# define png_snprintf(s1,n,fmt,x1) png_sprintf(s1,fmt,x1)
# define png_snprintf2(s1,n,fmt,x1,x2) png_sprintf(s1,fmt,x1,x2)
# define png_snprintf6(s1,n,fmt,x1,x2,x3,x4,x5,x6) \
png_sprintf(s1,fmt,x1,x2,x3,x4,x5,x6)#endif
/* End of 1.5.0beta36 move from pngconf.h */
/* CONSTANTS and UTILITY MACROS
* These are used internally by libpng and not exposed in the API */
/* Various modes of operation. Note that after an init, mode is set to
* zero automatically when the structure is created. */#define PNG_HAVE_IHDR 0x01
#define PNG_HAVE_PLTE 0x02
#define PNG_HAVE_IDAT 0x04
#define PNG_AFTER_IDAT 0x08 /* Have complete zlib datastream */
#define PNG_HAVE_IEND 0x10
#define PNG_HAVE_gAMA 0x20
#define PNG_HAVE_cHRM 0x40
#define PNG_HAVE_sRGB 0x80
#define PNG_HAVE_CHUNK_HEADER 0x100
#define PNG_WROTE_tIME 0x200
#define PNG_WROTE_INFO_BEFORE_PLTE 0x400
#define PNG_BACKGROUND_IS_GRAY 0x800
#define PNG_HAVE_PNG_SIGNATURE 0x1000
#define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000 /* Have another chunk after IDAT */
/* Flags for the transformations the PNG library does on the image data */#define PNG_BGR 0x0001
#define PNG_INTERLACE 0x0002
#define PNG_PACK 0x0004
#define PNG_SHIFT 0x0008
#define PNG_SWAP_BYTES 0x0010
#define PNG_INVERT_MONO 0x0020
#define PNG_QUANTIZE 0x0040
#define PNG_BACKGROUND 0x0080
#define PNG_BACKGROUND_EXPAND 0x0100
#define PNG_EXPAND_16 0x0200 /* Added to libpng 1.5.2 */
#define PNG_16_TO_8 0x0400
#define PNG_RGBA 0x0800
#define PNG_EXPAND 0x1000
#define PNG_GAMMA 0x2000
#define PNG_GRAY_TO_RGB 0x4000
#define PNG_FILLER 0x8000L
#define PNG_PACKSWAP 0x10000L
#define PNG_SWAP_ALPHA 0x20000L
#define PNG_STRIP_ALPHA 0x40000L
#define PNG_INVERT_ALPHA 0x80000L
#define PNG_USER_TRANSFORM 0x100000L
#define PNG_RGB_TO_GRAY_ERR 0x200000L
#define PNG_RGB_TO_GRAY_WARN 0x400000L
#define PNG_RGB_TO_GRAY 0x600000L /* two bits, RGB_TO_GRAY_ERR|WARN */
/* 0x800000L Unused */#define PNG_ADD_ALPHA 0x1000000L /* Added to libpng-1.2.7 */
#define PNG_EXPAND_tRNS 0x2000000L /* Added to libpng-1.2.9 */
/* 0x4000000L unused */ /* 0x8000000L unused */ /* 0x10000000L unused */ /* 0x20000000L unused */ /* 0x40000000L unused */
/* Flags for png_create_struct */#define PNG_STRUCT_PNG 0x0001
#define PNG_STRUCT_INFO 0x0002
/* Scaling factor for filter heuristic weighting calculations */#define PNG_WEIGHT_FACTOR (1<<(PNG_WEIGHT_SHIFT))
#define PNG_COST_FACTOR (1<<(PNG_COST_SHIFT))
/* Flags for the png_ptr->flags rather than declaring a byte for each one */#define PNG_FLAG_ZLIB_CUSTOM_STRATEGY 0x0001
#define PNG_FLAG_ZLIB_CUSTOM_LEVEL 0x0002
#define PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL 0x0004
#define PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS 0x0008
#define PNG_FLAG_ZLIB_CUSTOM_METHOD 0x0010
#define PNG_FLAG_ZLIB_FINISHED 0x0020
#define PNG_FLAG_ROW_INIT 0x0040
#define PNG_FLAG_FILLER_AFTER 0x0080
#define PNG_FLAG_CRC_ANCILLARY_USE 0x0100
#define PNG_FLAG_CRC_ANCILLARY_NOWARN 0x0200
#define PNG_FLAG_CRC_CRITICAL_USE 0x0400
#define PNG_FLAG_CRC_CRITICAL_IGNORE 0x0800
/* 0x1000 unused */ /* 0x2000 unused */ /* 0x4000 unused */#define PNG_FLAG_KEEP_UNKNOWN_CHUNKS 0x8000L
#define PNG_FLAG_KEEP_UNSAFE_CHUNKS 0x10000L
#define PNG_FLAG_LIBRARY_MISMATCH 0x20000L
#define PNG_FLAG_STRIP_ERROR_NUMBERS 0x40000L
#define PNG_FLAG_STRIP_ERROR_TEXT 0x80000L
#define PNG_FLAG_MALLOC_NULL_MEM_OK 0x100000L
/* 0x200000L unused */ /* 0x400000L unused */#define PNG_FLAG_BENIGN_ERRORS_WARN 0x800000L /* Added to libpng-1.4.0 */
/* 0x1000000L unused */ /* 0x2000000L unused */ /* 0x4000000L unused */ /* 0x8000000L unused */ /* 0x10000000L unused */ /* 0x20000000L unused */ /* 0x40000000L unused */
#define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \
PNG_FLAG_CRC_ANCILLARY_NOWARN)
#define PNG_FLAG_CRC_CRITICAL_MASK (PNG_FLAG_CRC_CRITICAL_USE | \
PNG_FLAG_CRC_CRITICAL_IGNORE)
#define PNG_FLAG_CRC_MASK (PNG_FLAG_CRC_ANCILLARY_MASK | \
PNG_FLAG_CRC_CRITICAL_MASK)
/* zlib.h declares a magic type 'uInt' that limits the amount of data that zlib
* can handle at once. This type need be no larger than 16 bits (so maximum of * 65535), this define allows us to discover how big it is, but limited by the * maximuum for png_size_t. The value can be overriden in a library build * (pngusr.h, or set it in CPPFLAGS) and it works to set it to a considerably * lower value (e.g. 255 works). A lower value may help memory usage (slightly) * and may even improve performance on some systems (and degrade it on others.) */#ifndef ZLIB_IO_MAX
# define ZLIB_IO_MAX ((uInt)-1)
#endif
/* Save typing and make code easier to understand */
#define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \
abs((int)((c1).green) - (int)((c2).green)) + \ abs((int)((c1).blue) - (int)((c2).blue)))
/* Added to libpng-1.2.6 JB */#define PNG_ROWBYTES(pixel_bits, width) \
((pixel_bits) >= 8 ? \ ((png_size_t)(width) * (((png_size_t)(pixel_bits)) >> 3)) : \ (( ((png_size_t)(width) * ((png_size_t)(pixel_bits))) + 7) >> 3) )
/* PNG_OUT_OF_RANGE returns true if value is outside the range
* ideal-delta..ideal+delta. Each argument is evaluated twice. * "ideal" and "delta" should be constants, normally simple * integers, "value" a variable. Added to libpng-1.2.6 JB */#define PNG_OUT_OF_RANGE(value, ideal, delta) \
( (value) < (ideal)-(delta) || (value) > (ideal)+(delta) )
/* Conversions between fixed and floating point, only defined if
* required (to make sure the code doesn't accidentally use float * when it is supposedly disabled.) */#ifdef PNG_FLOATING_POINT_SUPPORTED
/* The floating point conversion can't overflow, though it can and
* does lose accuracy relative to the original fixed point value. * In practice this doesn't matter because png_fixed_point only * stores numbers with very low precision. The png_ptr and s * arguments are unused by default but are there in case error * checking becomes a requirement. */#define png_float(png_ptr, fixed, s) (.00001 * (fixed))
/* The fixed point conversion performs range checking and evaluates
* its argument multiple times, so must be used with care. The * range checking uses the PNG specification values for a signed * 32 bit fixed point value except that the values are deliberately * rounded-to-zero to an integral value - 21474 (21474.83 is roughly * (2^31-1) * 100000). 's' is a string that describes the value being * converted. * * NOTE: this macro will raise a png_error if the range check fails, * therefore it is normally only appropriate to use this on values * that come from API calls or other sources where an out of range * error indicates a programming error, not a data error! * * NOTE: by default this is off - the macro is not used - because the * function call saves a lot of code. */#ifdef PNG_FIXED_POINT_MACRO_SUPPORTED
#define png_fixed(png_ptr, fp, s) ((fp) <= 21474 && (fp) >= -21474 ?\
((png_fixed_point)(100000 * (fp))) : (png_fixed_error(png_ptr, s),0))#else
PNG_EXTERN png_fixed_point png_fixed PNGARG((png_structp png_ptr, double fp, png_const_charp text));#endif
#endif
/* Constant strings for known chunk types. If you need to add a chunk,
* define the name here, and add an invocation of the macro wherever it's * needed. */#define PNG_IHDR PNG_CONST png_byte png_IHDR[5] = { 73, 72, 68, 82, '\0'}
#define PNG_IDAT PNG_CONST png_byte png_IDAT[5] = { 73, 68, 65, 84, '\0'}
#define PNG_IEND PNG_CONST png_byte png_IEND[5] = { 73, 69, 78, 68, '\0'}
#define PNG_PLTE PNG_CONST png_byte png_PLTE[5] = { 80, 76, 84, 69, '\0'}
#define PNG_bKGD PNG_CONST png_byte png_bKGD[5] = { 98, 75, 71, 68, '\0'}
#define PNG_cHRM PNG_CONST png_byte png_cHRM[5] = { 99, 72, 82, 77, '\0'}
#define PNG_gAMA PNG_CONST png_byte png_gAMA[5] = {103, 65, 77, 65, '\0'}
#define PNG_hIST PNG_CONST png_byte png_hIST[5] = {104, 73, 83, 84, '\0'}
#define PNG_iCCP PNG_CONST png_byte png_iCCP[5] = {105, 67, 67, 80, '\0'}
#define PNG_iTXt PNG_CONST png_byte png_iTXt[5] = {105, 84, 88, 116, '\0'}
#define PNG_oFFs PNG_CONST png_byte png_oFFs[5] = {111, 70, 70, 115, '\0'}
#define PNG_pCAL PNG_CONST png_byte png_pCAL[5] = {112, 67, 65, 76, '\0'}
#define PNG_sCAL PNG_CONST png_byte png_sCAL[5] = {115, 67, 65, 76, '\0'}
#define PNG_pHYs PNG_CONST png_byte png_pHYs[5] = {112, 72, 89, 115, '\0'}
#define PNG_sBIT PNG_CONST png_byte png_sBIT[5] = {115, 66, 73, 84, '\0'}
#define PNG_sPLT PNG_CONST png_byte png_sPLT[5] = {115, 80, 76, 84, '\0'}
#define PNG_sRGB PNG_CONST png_byte png_sRGB[5] = {115, 82, 71, 66, '\0'}
#define PNG_sTER PNG_CONST png_byte png_sTER[5] = {115, 84, 69, 82, '\0'}
#define PNG_tEXt PNG_CONST png_byte png_tEXt[5] = {116, 69, 88, 116, '\0'}
#define PNG_tIME PNG_CONST png_byte png_tIME[5] = {116, 73, 77, 69, '\0'}
#define PNG_tRNS PNG_CONST png_byte png_tRNS[5] = {116, 82, 78, 83, '\0'}
#define PNG_zTXt PNG_CONST png_byte png_zTXt[5] = {122, 84, 88, 116, '\0'}
/* Inhibit C++ name-mangling for libpng functions but not for system calls. */#ifdef __cplusplus
extern "C" {#endif /* __cplusplus */
/* These functions are used internally in the code. They generally
* shouldn't be used unless you are writing code to add or replace some * functionality in libpng. More information about most functions can * be found in the files where the functions are located. */
/* Allocate memory for an internal libpng struct */PNG_EXTERN PNG_FUNCTION(png_voidp,png_create_struct,PNGARG((int type)), PNG_ALLOCATED);
/* Free memory from internal libpng struct */PNG_EXTERN void png_destroy_struct PNGARG((png_voidp struct_ptr));
PNG_EXTERN PNG_FUNCTION(png_voidp,png_create_struct_2, PNGARG((int type, png_malloc_ptr malloc_fn, png_voidp mem_ptr)), PNG_ALLOCATED);PNG_EXTERN void png_destroy_struct_2 PNGARG((png_voidp struct_ptr, png_free_ptr free_fn, png_voidp mem_ptr));
/* Free any memory that info_ptr points to and reset struct. */PNG_EXTERN void png_info_destroy PNGARG((png_structp png_ptr, png_infop info_ptr));
/* Function to allocate memory for zlib. PNGAPI is disallowed. */PNG_EXTERN PNG_FUNCTION(voidpf,png_zalloc,PNGARG((voidpf png_ptr, uInt items, uInt size)),PNG_ALLOCATED);
/* Function to free memory for zlib. PNGAPI is disallowed. */PNG_EXTERN void png_zfree PNGARG((voidpf png_ptr, voidpf ptr));
/* Next four functions are used internally as callbacks. PNGCBAPI is required
* but not PNG_EXPORT. PNGAPI added at libpng version 1.2.3, changed to * PNGCBAPI at 1.5.0 */
PNG_EXTERN void PNGCBAPI png_default_read_data PNGARG((png_structp png_ptr, png_bytep data, png_size_t length));
#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
PNG_EXTERN void PNGCBAPI png_push_fill_buffer PNGARG((png_structp png_ptr, png_bytep buffer, png_size_t length));#endif
PNG_EXTERN void PNGCBAPI png_default_write_data PNGARG((png_structp png_ptr, png_bytep data, png_size_t length));
#ifdef PNG_WRITE_FLUSH_SUPPORTED
# ifdef PNG_STDIO_SUPPORTED
PNG_EXTERN void PNGCBAPI png_default_flush PNGARG((png_structp png_ptr));# endif
#endif
/* Reset the CRC variable */PNG_EXTERN void png_reset_crc PNGARG((png_structp png_ptr));
/* Write the "data" buffer to whatever output you are using */PNG_EXTERN void png_write_data PNGARG((png_structp png_ptr, png_const_bytep data, png_size_t length));
/* Read and check the PNG file signature */PNG_EXTERN void png_read_sig PNGARG((png_structp png_ptr, png_infop info_ptr));
/* Read the chunk header (length + type name) */PNG_EXTERN png_uint_32 png_read_chunk_header PNGARG((png_structp png_ptr));
/* Read data from whatever input you are using into the "data" buffer */PNG_EXTERN void png_read_data PNGARG((png_structp png_ptr, png_bytep data, png_size_t length));
/* Read bytes into buf, and update png_ptr->crc */PNG_EXTERN void png_crc_read PNGARG((png_structp png_ptr, png_bytep buf, png_size_t length));
/* Decompress data in a chunk that uses compression */#if defined(PNG_zTXt_SUPPORTED) || defined(PNG_iTXt_SUPPORTED) || \
defined(PNG_iCCP_SUPPORTED) || defined(PNG_sPLT_SUPPORTED)PNG_EXTERN void png_decompress_chunk PNGARG((png_structp png_ptr, int comp_type, png_size_t chunklength, png_size_t prefix_length, png_size_t *data_length));#endif
/* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */PNG_EXTERN int png_crc_finish PNGARG((png_structp png_ptr, png_uint_32 skip));
/* Read the CRC from the file and compare it to the libpng calculated CRC */PNG_EXTERN int png_crc_error PNGARG((png_structp png_ptr));
/* Calculate the CRC over a section of data. Note that we are only
* passing a maximum of 64K on systems that have this as a memory limit, * since this is the maximum buffer size we can specify. */PNG_EXTERN void png_calculate_crc PNGARG((png_structp png_ptr, png_const_bytep ptr, png_size_t length));
#ifdef PNG_WRITE_FLUSH_SUPPORTED
PNG_EXTERN void png_flush PNGARG((png_structp png_ptr));#endif
/* Write various chunks */
/* Write the IHDR chunk, and update the png_struct with the necessary
* information. */PNG_EXTERN void png_write_IHDR PNGARG((png_structp png_ptr, png_uint_32 width, png_uint_32 height, int bit_depth, int color_type, int compression_method, int filter_method, int interlace_method));
PNG_EXTERN void png_write_PLTE PNGARG((png_structp png_ptr, png_const_colorp palette, png_uint_32 num_pal));
PNG_EXTERN void png_write_IDAT PNGARG((png_structp png_ptr, png_bytep data, png_size_t length));
PNG_EXTERN void png_write_IEND PNGARG((png_structp png_ptr));
#ifdef PNG_WRITE_gAMA_SUPPORTED
# ifdef PNG_FLOATING_POINT_SUPPORTED
PNG_EXTERN void png_write_gAMA PNGARG((png_structp png_ptr, double file_gamma));# endif
# ifdef PNG_FIXED_POINT_SUPPORTED
PNG_EXTERN void png_write_gAMA_fixed PNGARG((png_structp png_ptr, png_fixed_point file_gamma));# endif
#endif
#ifdef PNG_WRITE_sBIT_SUPPORTED
PNG_EXTERN void png_write_sBIT PNGARG((png_structp png_ptr, png_const_color_8p sbit, int color_type));#endif
#ifdef PNG_WRITE_cHRM_SUPPORTED
# ifdef PNG_FLOATING_POINT_SUPPORTED
PNG_EXTERN void png_write_cHRM PNGARG((png_structp png_ptr, double white_x, double white_y, double red_x, double red_y, double green_x, double green_y, double blue_x, double blue_y));# endif
PNG_EXTERN void png_write_cHRM_fixed PNGARG((png_structp png_ptr, png_fixed_point int_white_x, png_fixed_point int_white_y, png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x, png_fixed_point int_blue_y));#endif
#ifdef PNG_WRITE_sRGB_SUPPORTED
PNG_EXTERN void png_write_sRGB PNGARG((png_structp png_ptr, int intent));#endif
#ifdef PNG_WRITE_iCCP_SUPPORTED
PNG_EXTERN void png_write_iCCP PNGARG((png_structp png_ptr, png_const_charp name, int compression_type, png_const_charp profile, int proflen)); /* Note to maintainer: profile should be png_bytep */#endif
#ifdef PNG_WRITE_sPLT_SUPPORTED
PNG_EXTERN void png_write_sPLT PNGARG((png_structp png_ptr, png_const_sPLT_tp palette));#endif
#ifdef PNG_WRITE_tRNS_SUPPORTED
PNG_EXTERN void png_write_tRNS PNGARG((png_structp png_ptr, png_const_bytep trans, png_const_color_16p values, int number, int color_type));#endif
#ifdef PNG_WRITE_bKGD_SUPPORTED
PNG_EXTERN void png_write_bKGD PNGARG((png_structp png_ptr, png_const_color_16p values, int color_type));#endif
#ifdef PNG_WRITE_hIST_SUPPORTED
PNG_EXTERN void png_write_hIST PNGARG((png_structp png_ptr, png_const_uint_16p hist, int num_hist));#endif
#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \
defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)PNG_EXTERN png_size_t png_check_keyword PNGARG((png_structp png_ptr, png_const_charp key, png_charpp new_key));#endif
#ifdef PNG_WRITE_tEXt_SUPPORTED
PNG_EXTERN void png_write_tEXt PNGARG((png_structp png_ptr, png_const_charp key, png_const_charp text, png_size_t text_len));#endif
#ifdef PNG_WRITE_zTXt_SUPPORTED
PNG_EXTERN void png_write_zTXt PNGARG((png_structp png_ptr, png_const_charp key, png_const_charp text, png_size_t text_len, int compression));#endif
#ifdef PNG_WRITE_iTXt_SUPPORTED
PNG_EXTERN void png_write_iTXt PNGARG((png_structp png_ptr, int compression, png_const_charp key, png_const_charp lang, png_const_charp lang_key, png_const_charp text));#endif
#ifdef PNG_TEXT_SUPPORTED /* Added at version 1.0.14 and 1.2.4 */
PNG_EXTERN int png_set_text_2 PNGARG((png_structp png_ptr, png_infop info_ptr, png_const_textp text_ptr, int num_text));#endif
#ifdef PNG_WRITE_oFFs_SUPPORTED
PNG_EXTERN void png_write_oFFs PNGARG((png_structp png_ptr, png_int_32 x_offset, png_int_32 y_offset, int unit_type));#endif
#ifdef PNG_WRITE_pCAL_SUPPORTED
PNG_EXTERN void png_write_pCAL PNGARG((png_structp png_ptr, png_charp purpose, png_int_32 X0, png_int_32 X1, int type, int nparams, png_const_charp units, png_charpp params));#endif
#ifdef PNG_WRITE_pHYs_SUPPORTED
PNG_EXTERN void png_write_pHYs PNGARG((png_structp png_ptr, png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit, int unit_type));#endif
#ifdef PNG_WRITE_tIME_SUPPORTED
PNG_EXTERN void png_write_tIME PNGARG((png_structp png_ptr, png_const_timep mod_time));#endif
#ifdef PNG_WRITE_sCAL_SUPPORTED
PNG_EXTERN void png_write_sCAL_s PNGARG((png_structp png_ptr, int unit, png_const_charp width, png_const_charp height));#endif
/* Called when finished processing a row of data */PNG_EXTERN void png_write_finish_row PNGARG((png_structp png_ptr));
/* Internal use only. Called before first row of data */PNG_EXTERN void png_write_start_row PNGARG((png_structp png_ptr));
/* Combine a row of data, dealing with alpha, etc. if requested */PNG_EXTERN void png_combine_row PNGARG((png_structp png_ptr, png_bytep row, int mask));
#ifdef PNG_READ_INTERLACING_SUPPORTED
/* Expand an interlaced row *//* OLD pre-1.0.9 interface:
PNG_EXTERN void png_do_read_interlace PNGARG((png_row_infop row_info, png_bytep row, int pass, png_uint_32 transformations)); */PNG_EXTERN void png_do_read_interlace PNGARG((png_structp png_ptr));#endif
/* GRR TO DO (2.0 or whenever): simplify other internal calling interfaces */
#ifdef PNG_WRITE_INTERLACING_SUPPORTED
/* Grab pixels out of a row for an interlaced pass */PNG_EXTERN void png_do_write_interlace PNGARG((png_row_infop row_info, png_bytep row, int pass));#endif
/* Unfilter a row */PNG_EXTERN void png_read_filter_row PNGARG((png_structp png_ptr, png_row_infop row_info, png_bytep row, png_const_bytep prev_row, int filter));
/* Choose the best filter to use and filter the row data */PNG_EXTERN void png_write_find_filter PNGARG((png_structp png_ptr, png_row_infop row_info));
/* Write out the filtered row. */PNG_EXTERN void png_write_filtered_row PNGARG((png_structp png_ptr, png_bytep filtered_row));/* Finish a row while reading, dealing with interlacing passes, etc. */PNG_EXTERN void png_read_finish_row PNGARG((png_structp png_ptr));
/* Initialize the row buffers, etc. */PNG_EXTERN void png_read_start_row PNGARG((png_structp png_ptr));/* Optional call to update the users info structure */PNG_EXTERN void png_read_transform_info PNGARG((png_structp png_ptr, png_infop info_ptr));
/* These are the functions that do the transformations */#ifdef PNG_READ_FILLER_SUPPORTED
PNG_EXTERN void png_do_read_filler PNGARG((png_row_infop row_info, png_bytep row, png_uint_32 filler, png_uint_32 flags));#endif
#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
PNG_EXTERN void png_do_read_swap_alpha PNGARG((png_row_infop row_info, png_bytep row));#endif
#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
PNG_EXTERN void png_do_write_swap_alpha PNGARG((png_row_infop row_info, png_bytep row));#endif
#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
PNG_EXTERN void png_do_read_invert_alpha PNGARG((png_row_infop row_info, png_bytep row));#endif
#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
PNG_EXTERN void png_do_write_invert_alpha PNGARG((png_row_infop row_info, png_bytep row));#endif
#if defined(PNG_WRITE_FILLER_SUPPORTED) || \
defined(PNG_READ_STRIP_ALPHA_SUPPORTED)PNG_EXTERN void png_do_strip_channel PNGARG((png_row_infop row_info, png_bytep row, int at_start));#endif
#ifdef PNG_16BIT_SUPPORTED
#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
PNG_EXTERN void png_do_swap PNGARG((png_row_infop row_info, png_bytep row));#endif
#endif
#if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
defined(PNG_WRITE_PACKSWAP_SUPPORTED)PNG_EXTERN void png_do_packswap PNGARG((png_row_infop row_info, png_bytep row));#endif
#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
PNG_EXTERN int png_do_rgb_to_gray PNGARG((png_structp png_ptr, png_row_infop row_info, png_bytep row));#endif
#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
PNG_EXTERN void png_do_gray_to_rgb PNGARG((png_row_infop row_info, png_bytep row));#endif
#ifdef PNG_READ_PACK_SUPPORTED
PNG_EXTERN void png_do_unpack PNGARG((png_row_infop row_info, png_bytep row));#endif
#ifdef PNG_READ_SHIFT_SUPPORTED
PNG_EXTERN void png_do_unshift PNGARG((png_row_infop row_info, png_bytep row, png_const_color_8p sig_bits));#endif
#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
PNG_EXTERN void png_do_invert PNGARG((png_row_infop row_info, png_bytep row));#endif
#ifdef PNG_READ_16_TO_8_SUPPORTED
PNG_EXTERN void png_do_chop PNGARG((png_row_infop row_info, png_bytep row));#endif
#ifdef PNG_READ_QUANTIZE_SUPPORTED
PNG_EXTERN void png_do_quantize PNGARG((png_row_infop row_info, png_bytep row, png_const_bytep palette_lookup, png_const_bytep quantize_lookup));
# ifdef PNG_CORRECT_PALETTE_SUPPORTED
PNG_EXTERN void png_correct_palette PNGARG((png_structp png_ptr, png_colorp palette, int num_palette));# endif
#endif
#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
PNG_EXTERN void png_do_bgr PNGARG((png_row_infop row_info, png_bytep row));#endif
#ifdef PNG_WRITE_PACK_SUPPORTED
PNG_EXTERN void png_do_pack PNGARG((png_row_infop row_info, png_bytep row, png_uint_32 bit_depth));#endif
#ifdef PNG_WRITE_SHIFT_SUPPORTED
PNG_EXTERN void png_do_shift PNGARG((png_row_infop row_info, png_bytep row, png_const_color_8p bit_depth));#endif
#ifdef PNG_READ_BACKGROUND_SUPPORTED
# ifdef PNG_READ_GAMMA_SUPPORTED
PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info, png_bytep row, png_const_color_16p trans_color, png_const_color_16p background, png_const_color_16p background_1, png_const_bytep gamma_table, png_const_bytep gamma_from_1, png_const_bytep gamma_to_1, png_const_uint_16pp gamma_16, png_const_uint_16pp gamma_16_from_1, png_const_uint_16pp gamma_16_to_1, int gamma_shift));# else
PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info, png_bytep row, png_const_color_16p trans_color, png_const_color_16p background));# endif
#endif
#ifdef PNG_READ_GAMMA_SUPPORTED
PNG_EXTERN void png_do_gamma PNGARG((png_row_infop row_info, png_bytep row, png_const_bytep gamma_table, png_const_uint_16pp gamma_16_table, int gamma_shift));#endif
#ifdef PNG_READ_EXPAND_SUPPORTED
PNG_EXTERN void png_do_expand_palette PNGARG((png_row_infop row_info, png_bytep row, png_const_colorp palette, png_const_bytep trans, int num_trans));PNG_EXTERN void png_do_expand PNGARG((png_row_infop row_info, png_bytep row, png_const_color_16p trans_color));#endif
#ifdef PNG_READ_EXPAND_16_SUPPORTED
PNG_EXTERN void png_do_expand_16 PNGARG((png_row_infop row_info, png_bytep row));#endif
/* The following decodes the appropriate chunks, and does error correction,
* then calls the appropriate callback for the chunk if it is valid. */
/* Decode the IHDR chunk */PNG_EXTERN void png_handle_IHDR PNGARG((png_structp png_ptr, png_infop info_ptr, png_uint_32 length));PNG_EXTERN void png_handle_PLTE PNGARG((png_structp png_ptr, png_infop info_ptr, png_uint_32 length));PNG_EXTERN void png_handle_IEND PNGARG((png_structp png_ptr, png_infop info_ptr, png_uint_32 length));
#ifdef PNG_READ_bKGD_SUPPORTED
PNG_EXTERN void png_handle_bKGD PNGARG((png_structp png_ptr, png_infop info_ptr, png_uint_32 length));#endif
#ifdef PNG_READ_cHRM_SUPPORTED
PNG_EXTERN void png_handle_cHRM PNGARG((png_structp png_ptr, png_infop info_ptr, png_uint_32 length));#endif
#ifdef PNG_READ_gAMA_SUPPORTED
PNG_EXTERN void png_handle_gAMA PNGARG((png_structp png_ptr, png_infop info_ptr, png_uint_32 length));#endif
#ifdef PNG_READ_hIST_SUPPORTED
PNG_EXTERN void png_handle_hIST PNGARG((png_structp png_ptr, png_infop info_ptr, png_uint_32 length));#endif
#ifdef PNG_READ_iCCP_SUPPORTED
PNG_EXTERN void png_handle_iCCP PNGARG((png_structp png_ptr, png_infop info_ptr, png_uint_32 length));#endif /* PNG_READ_iCCP_SUPPORTED */
#ifdef PNG_READ_iTXt_SUPPORTED
PNG_EXTERN void png_handle_iTXt PNGARG((png_structp png_ptr, png_infop info_ptr, png_uint_32 length));#endif
#ifdef PNG_READ_oFFs_SUPPORTED
PNG_EXTERN void png_handle_oFFs PNGARG((png_structp png_ptr, png_infop info_ptr, png_uint_32 length));#endif
#ifdef PNG_READ_pCAL_SUPPORTED
PNG_EXTERN void png_handle_pCAL PNGARG((png_structp png_ptr, png_infop info_ptr, png_uint_32 length));#endif
#ifdef PNG_READ_pHYs_SUPPORTED
PNG_EXTERN void png_handle_pHYs PNGARG((png_structp png_ptr, png_infop info_ptr, png_uint_32 length));#endif
#ifdef PNG_READ_sBIT_SUPPORTED
PNG_EXTERN void png_handle_sBIT PNGARG((png_structp png_ptr, png_infop info_ptr, png_uint_32 length));#endif
#ifdef PNG_READ_sCAL_SUPPORTED
PNG_EXTERN void png_handle_sCAL PNGARG((png_structp png_ptr, png_infop info_ptr, png_uint_32 length));#endif
#ifdef PNG_READ_sPLT_SUPPORTED
PNG_EXTERN void png_handle_sPLT PNGARG((png_structp png_ptr, png_infop info_ptr, png_uint_32 length));#endif /* PNG_READ_sPLT_SUPPORTED */
#ifdef PNG_READ_sRGB_SUPPORTED
PNG_EXTERN void png_handle_sRGB PNGARG((png_structp png_ptr, png_infop info_ptr, png_uint_32 length));#endif
#ifdef PNG_READ_tEXt_SUPPORTED
PNG_EXTERN void png_handle_tEXt PNGARG((png_structp png_ptr, png_infop info_ptr, png_uint_32 length));#endif
#ifdef PNG_READ_tIME_SUPPORTED
PNG_EXTERN void png_handle_tIME PNGARG((png_structp png_ptr, png_infop info_ptr, png_uint_32 length));#endif
#ifdef PNG_READ_tRNS_SUPPORTED
PNG_EXTERN void png_handle_tRNS PNGARG((png_structp png_ptr, png_infop info_ptr, png_uint_32 length));#endif
#ifdef PNG_READ_zTXt_SUPPORTED
PNG_EXTERN void png_handle_zTXt PNGARG((png_structp png_ptr, png_infop info_ptr, png_uint_32 length));#endif
PNG_EXTERN void png_handle_unknown PNGARG((png_structp png_ptr, png_infop info_ptr, png_uint_32 length));
PNG_EXTERN void png_check_chunk_name PNGARG((png_structp png_ptr, png_const_bytep chunk_name));
/* Handle the transformations for reading and writing */PNG_EXTERN void png_do_read_transformations PNGARG((png_structp png_ptr));PNG_EXTERN void png_do_write_transformations PNGARG((png_structp png_ptr));
PNG_EXTERN void png_init_read_transformations PNGARG((png_structp png_ptr));
#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
PNG_EXTERN void png_push_read_chunk PNGARG((png_structp png_ptr, png_infop info_ptr));PNG_EXTERN void png_push_read_sig PNGARG((png_structp png_ptr, png_infop info_ptr));PNG_EXTERN void png_push_check_crc PNGARG((png_structp png_ptr));PNG_EXTERN void png_push_crc_skip PNGARG((png_structp png_ptr, png_uint_32 length));PNG_EXTERN void png_push_crc_finish PNGARG((png_structp png_ptr));PNG_EXTERN void png_push_save_buffer PNGARG((png_structp png_ptr));PNG_EXTERN void png_push_restore_buffer PNGARG((png_structp png_ptr, png_bytep buffer, png_size_t buffer_length));PNG_EXTERN void png_push_read_IDAT PNGARG((png_structp png_ptr));PNG_EXTERN void png_process_IDAT_data PNGARG((png_structp png_ptr, png_bytep buffer, png_size_t buffer_length));PNG_EXTERN void png_push_process_row PNGARG((png_structp png_ptr));PNG_EXTERN void png_push_handle_unknown PNGARG((png_structp png_ptr, png_infop info_ptr, png_uint_32 length));PNG_EXTERN void png_push_have_info PNGARG((png_structp png_ptr, png_infop info_ptr));PNG_EXTERN void png_push_have_end PNGARG((png_structp png_ptr, png_infop info_ptr));PNG_EXTERN void png_push_have_row PNGARG((png_structp png_ptr, png_bytep row));PNG_EXTERN void png_push_read_end PNGARG((png_structp png_ptr, png_infop info_ptr));PNG_EXTERN void png_process_some_data PNGARG((png_structp png_ptr, png_infop info_ptr));PNG_EXTERN void png_read_push_finish_row PNGARG((png_structp png_ptr));# ifdef PNG_READ_tEXt_SUPPORTED
PNG_EXTERN void png_push_handle_tEXt PNGARG((png_structp png_ptr, png_infop info_ptr, png_uint_32 length));PNG_EXTERN void png_push_read_tEXt PNGARG((png_structp png_ptr, png_infop info_ptr));# endif
# ifdef PNG_READ_zTXt_SUPPORTED
PNG_EXTERN void png_push_handle_zTXt PNGARG((png_structp png_ptr, png_infop info_ptr, png_uint_32 length));PNG_EXTERN void png_push_read_zTXt PNGARG((png_structp png_ptr, png_infop info_ptr));# endif
# ifdef PNG_READ_iTXt_SUPPORTED
PNG_EXTERN void png_push_handle_iTXt PNGARG((png_structp png_ptr, png_infop info_ptr, png_uint_32 length));PNG_EXTERN void png_push_read_iTXt PNGARG((png_structp png_ptr, png_infop info_ptr));# endif
#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
#ifdef PNG_MNG_FEATURES_SUPPORTED
PNG_EXTERN void png_do_read_intrapixel PNGARG((png_row_infop row_info, png_bytep row));PNG_EXTERN void png_do_write_intrapixel PNGARG((png_row_infop row_info, png_bytep row));#endif
/* Added at libpng version 1.4.0 */#ifdef PNG_CHECK_cHRM_SUPPORTED
PNG_EXTERN int png_check_cHRM_fixed PNGARG((png_structp png_ptr, png_fixed_point int_white_x, png_fixed_point int_white_y, png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x, png_fixed_point int_blue_y));#endif
#ifdef PNG_CHECK_cHRM_SUPPORTED
/* Added at libpng version 1.2.34 and 1.4.0 *//* Currently only used by png_check_cHRM_fixed */PNG_EXTERN void png_64bit_product PNGARG((long v1, long v2, unsigned long *hi_product, unsigned long *lo_product));#endif
/* Added at libpng version 1.4.0 */PNG_EXTERN void png_check_IHDR PNGARG((png_structp png_ptr, png_uint_32 width, png_uint_32 height, int bit_depth, int color_type, int interlace_type, int compression_type, int filter_type));
/* Free all memory used by the read (old method - NOT DLL EXPORTED) */PNG_EXTERN void png_read_destroy PNGARG((png_structp png_ptr, png_infop info_ptr, png_infop end_info_ptr));
/* Free any memory used in png_ptr struct (old method - NOT DLL EXPORTED) */PNG_EXTERN void png_write_destroy PNGARG((png_structp png_ptr));
#ifdef USE_FAR_KEYWORD /* memory model conversion function */
PNG_EXTERN void *png_far_to_near PNGARG((png_structp png_ptr, png_voidp ptr, int check));#endif /* USE_FAR_KEYWORD */
#if defined(PNG_FLOATING_POINT_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED)
PNG_EXTERN PNG_FUNCTION(void, png_fixed_error, (png_structp png_ptr, png_const_charp name),PNG_NORETURN);#endif
/* ASCII to FP interfaces, currently only implemented if sCAL
* support is required. */#if defined(PNG_READ_sCAL_SUPPORTED)
/* MAX_DIGITS is actually the maximum number of characters in an sCAL
* width or height, derived from the precision (number of significant * digits - a build time settable option) and assumpitions about the * maximum ridiculous exponent. */#define PNG_sCAL_MAX_DIGITS (PNG_sCAL_PRECISION+1/*.*/+1/*E*/+10/*exponent*/)
#ifdef PNG_FLOATING_POINT_SUPPORTED
PNG_EXTERN void png_ascii_from_fp PNGARG((png_structp png_ptr, png_charp ascii, png_size_t size, double fp, unsigned int precision));#endif /* FLOATING_POINT */
#ifdef PNG_FIXED_POINT_SUPPORTED
PNG_EXTERN void png_ascii_from_fixed PNGARG((png_structp png_ptr, png_charp ascii, png_size_t size, png_fixed_point fp));#endif /* FIXED_POINT */
#endif /* READ_sCAL */
#if defined(PNG_sCAL_SUPPORTED) || defined(PNG_pCAL_SUPPORTED)
/* An internal API to validate the format of a floating point number.
* The result is the index of the next character. If the number is * not valid it will be the index of a character in the supposed number. * * The format of a number is defined in the PNG extensions specification * and this API is strictly conformant to that spec, not anyone elses! * * The format as a regular expression is: * * [+-]?[0-9]+.?([Ee][+-]?[0-9]+)? * * or: * * [+-]?.[0-9]+(.[0-9]+)?([Ee][+-]?[0-9]+)? * * The complexity is that either integer or fraction must be present and the * fraction is permitted to have no digits only if the integer is present. * * NOTE: The dangling E problem. * There is a PNG valid floating point number in the following: * * PNG floating point numb1.ers are not greedy. * * Working this out requires *TWO* character lookahead (because of the * sign), the parser does not do this - it will fail at the 'r' - this * doesn't matter for PNG sCAL chunk values, but it requires more care * if the value were ever to be embedded in something more complex. Use * ANSI-C strtod if you need the lookahead. *//* State table for the parser. */#define PNG_FP_INTEGER 0 /* before or in integer */
#define PNG_FP_FRACTION 1 /* before or in fraction */
#define PNG_FP_EXPONENT 2 /* before or in exponent */
#define PNG_FP_STATE 3 /* mask for the above */
#define PNG_FP_SAW_SIGN 4 /* Saw +/- in current state */
#define PNG_FP_SAW_DIGIT 8 /* Saw a digit in current state */
#define PNG_FP_SAW_DOT 16 /* Saw a dot in current state */
#define PNG_FP_SAW_E 32 /* Saw an E (or e) in current state */
#define PNG_FP_SAW_ANY 60 /* Saw any of the above 4 */
#define PNG_FP_WAS_VALID 64 /* Preceding substring is a valid fp number */
#define PNG_FP_INVALID 128 /* Available for callers as a distinct value */
/* Result codes for the parser (boolean - true meants ok, false means
* not ok yet.) */#define PNG_FP_MAYBE 0 /* The number may be valid in the future */
#define PNG_FP_OK 1 /* The number is valid */
/* The actual parser. This can be called repeatedly, it updates
* the index into the string and the state variable (which must * be initialzed to 0). It returns a result code, as above. There * is no point calling the parser any more if it fails to advance to * the end of the string - it is stuck on an invalid character (or * terminated by '\0'). * * Note that the pointer will consume an E or even an E+ then leave * a 'maybe' state even though a preceding integer.fraction is valid. * The PNG_FP_WAS_VALID flag indicates that a preceding substring was * a valid number. It's possible to recover from this by calling * the parser again (from the start, with state 0) but with a string * that omits the last character (i.e. set the size to the index of * the problem character.) This has not been tested within libpng. */PNG_EXTERN int png_check_fp_number PNGARG((png_const_charp string, png_size_t size, int *statep, png_size_tp whereami));
/* This is the same but it checks a complete string and returns true
* only if it just contains a floating point number. */PNG_EXTERN int png_check_fp_string PNGARG((png_const_charp string, png_size_t size));#endif /* pCAL || sCAL */
#if defined(PNG_READ_GAMMA_SUPPORTED) ||\
defined(PNG_INCH_CONVERSIONS_SUPPORTED) || defined(PNG_READ_pHYs_SUPPORTED)/* Added at libpng version 1.5.0 *//* This is a utility to provide a*times/div (rounded) and indicate
* if there is an overflow. The result is a boolean - false (0) * for overflow, true (1) if no overflow, in which case *res * holds the result. */PNG_EXTERN int png_muldiv PNGARG((png_fixed_point_p res, png_fixed_point a, png_int_32 multiplied_by, png_int_32 divided_by));#endif
#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_INCH_CONVERSIONS_SUPPORTED)
/* Same deal, but issue a warning on overflow and return 0. */PNG_EXTERN png_fixed_point png_muldiv_warn PNGARG((png_structp png_ptr, png_fixed_point a, png_int_32 multiplied_by, png_int_32 divided_by));#endif
#ifdef PNG_READ_GAMMA_SUPPORTED
/* Calculate a reciprocal - used for gamma values. This returns
* 0 if the argument is 0 in order to maintain an undefined value, * there are no warnings. */PNG_EXTERN png_fixed_point png_reciprocal PNGARG((png_fixed_point a));
/* The same but gives a reciprocal of the product of two fixed point
* values. Accuracy is suitable for gamma calculations but this is * not exact - use png_muldiv for that. */PNG_EXTERN png_fixed_point png_reciprocal2 PNGARG((png_fixed_point a, png_fixed_point b));#endif
#ifdef PNG_READ_GAMMA_SUPPORTED
/* Internal fixed point gamma correction. These APIs are called as
* required to convert single values - they don't need to be fast, * they are not used when processing image pixel values. * * While the input is an 'unsigned' value it must actually be the * correct bit value - 0..255 or 0..65535 as required. */PNG_EXTERN png_uint_16 png_gamma_correct PNGARG((png_structp png_ptr, unsigned int value, png_fixed_point gamma_value));PNG_EXTERN int png_gamma_significant PNGARG((png_fixed_point gamma_value));PNG_EXTERN png_uint_16 png_gamma_16bit_correct PNGARG((unsigned int value, png_fixed_point gamma_value));PNG_EXTERN png_byte png_gamma_8bit_correct PNGARG((unsigned int value, png_fixed_point gamma_value));PNG_EXTERN void png_build_gamma_table PNGARG((png_structp png_ptr, int bit_depth));#endif
/* Maintainer: Put new private prototypes here ^ and in libpngpf.3 */
#include "pngdebug.h"
#ifdef __cplusplus
}#endif
#endif /* PNGPRIV_H */
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