pngpriv.h

/* pngpriv.h - private declarations for use inside libpng
 *
 * libpng version 1.4.0beta18 - December 8, 2006
 * For conditions of distribution and use, see copyright notice in png.h
 * Copyright (c) 1998-2006 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.)
 */

/* 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

#ifndef PNG_VERSION_INFO_ONLY

#include <stdlib.h>

/* 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 will be made available again.
#define PNG_EXTERN extern
 */
#define PNG_EXTERN

/* 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)
#  if defined(MACOS)
     /* 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

/* Codewarrior on NT has linking problems without this. */
#if (defined(__MWERKS__) && defined(WIN32)) || defined(__STDC__)
#  define PNG_ALWAYS_EXTERN
#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 */
/* I have no idea why is this necessary... */
#  if defined(_MSC_VER)
#    include <malloc.h>
#  endif
#endif

/* This controls how fine the dithering gets.  As this allocates
 * a largish chunk of memory (32K), those who are not as concerned
 * with dithering quality can decrease some or all of these.
 */
#ifndef PNG_DITHER_RED_BITS
#  define PNG_DITHER_RED_BITS 5
#endif
#ifndef PNG_DITHER_GREEN_BITS
#  define PNG_DITHER_GREEN_BITS 5
#endif
#ifndef PNG_DITHER_BLUE_BITS
#  define PNG_DITHER_BLUE_BITS 5
#endif

/* This controls how fine the gamma correction becomes when you
 * are only interested in 8 bits anyway.  Increasing this value
 * results in more memory being used, and more pow() functions
 * being called to fill in the gamma tables.  Don't set this value
 * less then 8, and even that may not work (I haven't tested it).
 */

#ifndef PNG_MAX_GAMMA_8
#  define PNG_MAX_GAMMA_8 11
#endif

/* This controls how much a difference in gamma we can tolerate before
 * we actually start doing gamma conversion.
 */
#ifndef PNG_GAMMA_THRESHOLD
#  define PNG_GAMMA_THRESHOLD 0.05
#endif

/* 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_DITHER             0x0040
#define PNG_BACKGROUND         0x0080
#define PNG_BACKGROUND_EXPAND  0x0100
                          /*   0x0200 unused */
#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_SHIFT 8
#define PNG_WEIGHT_FACTOR (1<<(PNG_WEIGHT_SHIFT))
#define PNG_COST_SHIFT 3
#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
#define PNG_FLAG_FREE_PLTE                0x1000
#define PNG_FLAG_FREE_TRNS                0x2000
#define PNG_FLAG_FREE_HIST                0x4000
#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
#define PNG_FLAG_ADD_ALPHA                0x200000L  /* Added to libpng-1.2.8 */
#define PNG_FLAG_STRIP_ALPHA              0x400000L  /* Added to libpng-1.2.8 */
#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)

/* 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) )

/* variables declared in png.c - only it needs to define PNG_NO_EXTERN */
#if !defined(PNG_NO_EXTERN) || defined(PNG_ALWAYS_EXTERN)
/* place to hold the signature string for a PNG file. */
#ifdef PNG_USE_GLOBAL_ARRAYS
   PNG_EXPORT_VAR (const png_byte FARDATA) png_sig[8];
#else
#if 0
#define png_sig png_sig_bytes(NULL)
#endif
#endif
#endif /* PNG_NO_EXTERN */

/* Constant strings for known chunk types.  If you need to add a chunk,
 * define the name here, and add an invocation of the macro in png.c and
 * wherever it's needed.
 */
#define PNG_IHDR const png_byte png_IHDR[5] = { 73,  72,  68,  82, '\0'}
#define PNG_IDAT const png_byte png_IDAT[5] = { 73,  68,  65,  84, '\0'}
#define PNG_IEND const png_byte png_IEND[5] = { 73,  69,  78,  68, '\0'}
#define PNG_PLTE const png_byte png_PLTE[5] = { 80,  76,  84,  69, '\0'}
#define PNG_bKGD const png_byte png_bKGD[5] = { 98,  75,  71,  68, '\0'}
#define PNG_cHRM const png_byte png_cHRM[5] = { 99,  72,  82,  77, '\0'}
#define PNG_gAMA const png_byte png_gAMA[5] = {103,  65,  77,  65, '\0'}
#define PNG_hIST const png_byte png_hIST[5] = {104,  73,  83,  84, '\0'}
#define PNG_iCCP const png_byte png_iCCP[5] = {105,  67,  67,  80, '\0'}
#define PNG_iTXt const png_byte png_iTXt[5] = {105,  84,  88, 116, '\0'}
#define PNG_oFFs const png_byte png_oFFs[5] = {111,  70,  70, 115, '\0'}
#define PNG_pCAL const png_byte png_pCAL[5] = {112,  67,  65,  76, '\0'}
#define PNG_sCAL const png_byte png_sCAL[5] = {115,  67,  65,  76, '\0'}
#define PNG_pHYs const png_byte png_pHYs[5] = {112,  72,  89, 115, '\0'}
#define PNG_sBIT const png_byte png_sBIT[5] = {115,  66,  73,  84, '\0'}
#define PNG_sPLT const png_byte png_sPLT[5] = {115,  80,  76,  84, '\0'}
#define PNG_sRGB const png_byte png_sRGB[5] = {115,  82,  71,  66, '\0'}
#define PNG_sTER const png_byte png_sTER[5] = {115,  84,  69,  82, '\0'}
#define PNG_tEXt const png_byte png_tEXt[5] = {116,  69,  88, 116, '\0'}
#define PNG_tIME const png_byte png_tIME[5] = {116,  73,  77,  69, '\0'}
#define PNG_tRNS const png_byte png_tRNS[5] = {116,  82,  78,  83, '\0'}
#define PNG_zTXt const png_byte png_zTXt[5] = {122,  84,  88, 116, '\0'}

#ifdef PNG_USE_GLOBAL_ARRAYS
PNG_EXPORT_VAR (const png_byte FARDATA) png_IHDR[5];
PNG_EXPORT_VAR (const png_byte FARDATA) png_IDAT[5];
PNG_EXPORT_VAR (const png_byte FARDATA) png_IEND[5];
PNG_EXPORT_VAR (const png_byte FARDATA) png_PLTE[5];
PNG_EXPORT_VAR (const png_byte FARDATA) png_bKGD[5];
PNG_EXPORT_VAR (const png_byte FARDATA) png_cHRM[5];
PNG_EXPORT_VAR (const png_byte FARDATA) png_gAMA[5];
PNG_EXPORT_VAR (const png_byte FARDATA) png_hIST[5];
PNG_EXPORT_VAR (const png_byte FARDATA) png_iCCP[5];
PNG_EXPORT_VAR (const png_byte FARDATA) png_iTXt[5];
PNG_EXPORT_VAR (const png_byte FARDATA) png_oFFs[5];
PNG_EXPORT_VAR (const png_byte FARDATA) png_pCAL[5];
PNG_EXPORT_VAR (const png_byte FARDATA) png_sCAL[5];
PNG_EXPORT_VAR (const png_byte FARDATA) png_pHYs[5];
PNG_EXPORT_VAR (const png_byte FARDATA) png_sBIT[5];
PNG_EXPORT_VAR (const png_byte FARDATA) png_sPLT[5];
PNG_EXPORT_VAR (const png_byte FARDATA) png_sRGB[5];
PNG_EXPORT_VAR (const png_byte FARDATA) png_tEXt[5];
PNG_EXPORT_VAR (const png_byte FARDATA) png_tIME[5];
PNG_EXPORT_VAR (const png_byte FARDATA) png_tRNS[5];
PNG_EXPORT_VAR (const png_byte FARDATA) png_zTXt[5];
#endif /* PNG_USE_GLOBAL_ARRAYS */

/* 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.
 */

extern PNG_EXPORT(void,png_read_init_3) PNGARG((png_structpp ptr_ptr,
    png_const_charp user_png_ver, png_size_t png_struct_size));
extern PNG_EXPORT(void,png_write_init_3) PNGARG((png_structpp ptr_ptr,
    png_const_charp user_png_ver, png_size_t png_struct_size));
extern PNG_EXPORT(void,png_write_init_2) PNGARG((png_structp png_ptr,
    png_const_charp user_png_ver, png_size_t png_struct_size, png_size_t
    png_info_size));

/* Allocate memory for an internal libpng struct */
PNG_EXTERN png_voidp png_create_struct PNGARG((int type));

/* Free memory from internal libpng struct */
PNG_EXTERN void png_destroy_struct PNGARG((png_voidp struct_ptr));

PNG_EXTERN png_voidp png_create_struct_2 PNGARG((int type, png_malloc_ptr
  malloc_fn, png_voidp mem_ptr));
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 voidpf png_zalloc PNGARG((voidpf png_ptr, uInt items, uInt size));

/* 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.  PNGAPI is required
 * but not PNG_EXPORT.  PNGAPI added at libpng version 1.2.3. */

PNG_EXTERN void PNGAPI png_default_read_data PNGARG((png_structp png_ptr,
   png_bytep data, png_size_t length));

#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
PNG_EXTERN void PNGAPI png_push_fill_buffer PNGARG((png_structp png_ptr,
   png_bytep buffer, png_size_t length));
#endif

PNG_EXTERN void PNGAPI png_default_write_data PNGARG((png_structp png_ptr,
   png_bytep data, png_size_t length));

#if defined(PNG_WRITE_FLUSH_SUPPORTED)
#if !defined(PNG_NO_STDIO)
PNG_EXTERN void PNGAPI 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_bytep data,
   png_size_t length));

/* 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 png_charp png_decompress_chunk PNGARG((png_structp png_ptr,
   int comp_type, png_charp chunkdata, 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_bytep ptr,
   png_size_t length));

#if defined(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_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));

#if defined(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

#if defined(PNG_WRITE_sBIT_SUPPORTED)
PNG_EXTERN void png_write_sBIT PNGARG((png_structp png_ptr, png_color_8p sbit,
   int color_type));
#endif

#if defined(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
#ifdef PNG_FIXED_POINT_SUPPORTED
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
#endif

#if defined(PNG_WRITE_sRGB_SUPPORTED)
PNG_EXTERN void png_write_sRGB PNGARG((png_structp png_ptr,
   int intent));
#endif

#if defined(PNG_WRITE_iCCP_SUPPORTED)
PNG_EXTERN void png_write_iCCP PNGARG((png_structp png_ptr,
   png_charp name, int compression_type,
   png_charp profile, int proflen));
   /* Note to maintainer: profile should be png_bytep */
#endif

#if defined(PNG_WRITE_sPLT_SUPPORTED)
PNG_EXTERN void png_write_sPLT PNGARG((png_structp png_ptr,
   png_sPLT_tp palette));
#endif

#if defined(PNG_WRITE_tRNS_SUPPORTED)
PNG_EXTERN void png_write_tRNS PNGARG((png_structp png_ptr, png_bytep trans,
   png_color_16p values, int number, int color_type));
#endif

#if defined(PNG_WRITE_bKGD_SUPPORTED)
PNG_EXTERN void png_write_bKGD PNGARG((png_structp png_ptr,
   png_color_16p values, int color_type));
#endif

#if defined(PNG_WRITE_hIST_SUPPORTED)
PNG_EXTERN void png_write_hIST PNGARG((png_structp png_ptr, png_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_charp key, png_charpp new_key));
#endif

#if defined(PNG_WRITE_tEXt_SUPPORTED)
PNG_EXTERN void png_write_tEXt PNGARG((png_structp png_ptr, png_charp key,
   png_charp text, png_size_t text_len));
#endif

#if defined(PNG_WRITE_zTXt_SUPPORTED)
PNG_EXTERN void png_write_zTXt PNGARG((png_structp png_ptr, png_charp key,
   png_charp text, png_size_t text_len, int compression));
#endif

#if defined(PNG_WRITE_iTXt_SUPPORTED)
PNG_EXTERN void png_write_iTXt PNGARG((png_structp png_ptr,
   int compression, png_charp key, png_charp lang, png_charp lang_key,
   png_charp text));
#endif

#if defined(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_textp text_ptr, int num_text));
#endif

#if defined(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

#if defined(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_charp units, png_charpp params));
#endif

#if defined(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

#if defined(PNG_WRITE_tIME_SUPPORTED)
PNG_EXTERN void png_write_tIME PNGARG((png_structp png_ptr,
   png_timep mod_time));
#endif

#if defined(PNG_WRITE_sCAL_SUPPORTED)
#if defined(PNG_FLOATING_POINT_SUPPORTED) && !defined(PNG_NO_STDIO)
PNG_EXTERN void png_write_sCAL PNGARG((png_structp png_ptr,
   int unit, double width, double height));
#else
#ifdef PNG_FIXED_POINT_SUPPORTED
PNG_EXTERN void png_write_sCAL_s PNGARG((png_structp png_ptr,
   int unit, png_charp width, png_charp height));
#endif
#endif
#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));

#if defined(PNG_READ_GAMMA_SUPPORTED)
PNG_EXTERN void png_build_gamma_table PNGARG((png_structp png_ptr));
#endif

/* 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));

#if defined(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 */

#if defined(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_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 */
#if defined(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

#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED)
PNG_EXTERN void png_do_read_swap_alpha PNGARG((png_row_infop row_info,
   png_bytep row));
#endif

#if defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
PNG_EXTERN void png_do_write_swap_alpha PNGARG((png_row_infop row_info,
   png_bytep row));
#endif

#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)
PNG_EXTERN void png_do_read_invert_alpha PNGARG((png_row_infop row_info,
   png_bytep row));
#endif

#if defined(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_filler PNGARG((png_row_infop row_info,
   png_bytep row, png_uint_32 flags));
#endif

#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

#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

#if defined(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

#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
PNG_EXTERN void png_do_gray_to_rgb PNGARG((png_row_infop row_info,
   png_bytep row));
#endif

#if defined(PNG_READ_PACK_SUPPORTED)
PNG_EXTERN void png_do_unpack PNGARG((png_row_infop row_info, png_bytep row));
#endif

#if defined(PNG_READ_SHIFT_SUPPORTED)
PNG_EXTERN void png_do_unshift PNGARG((png_row_infop row_info, png_bytep row,
   png_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

#if defined(PNG_READ_16_TO_8_SUPPORTED)
PNG_EXTERN void png_do_chop PNGARG((png_row_infop row_info, png_bytep row));
#endif

#if defined(PNG_READ_DITHER_SUPPORTED)
PNG_EXTERN void png_do_dither PNGARG((png_row_infop row_info,
   png_bytep row, png_bytep palette_lookup, png_bytep dither_lookup));

#  if defined(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

#if defined(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

#if defined(PNG_WRITE_SHIFT_SUPPORTED)
PNG_EXTERN void png_do_shift PNGARG((png_row_infop row_info, png_bytep row,
   png_color_8p bit_depth));
#endif

#if defined(PNG_READ_BACKGROUND_SUPPORTED)
#if defined(PNG_READ_GAMMA_SUPPORTED)
PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info, png_bytep row,
   png_color_16p trans_values, png_color_16p background,
   png_color_16p background_1,
   png_bytep gamma_table, png_bytep gamma_from_1, png_bytep gamma_to_1,
   png_uint_16pp gamma_16, png_uint_16pp gamma_16_from_1,
   png_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_color_16p trans_values, png_color_16p background));
#endif
#endif

#if defined(PNG_READ_GAMMA_SUPPORTED)
PNG_EXTERN void png_do_gamma PNGARG((png_row_infop row_info, png_bytep row,
   png_bytep gamma_table, png_uint_16pp gamma_16_table,
   int gamma_shift));
#endif

#if defined(PNG_READ_EXPAND_SUPPORTED)
PNG_EXTERN void png_do_expand_palette PNGARG((png_row_infop row_info,
   png_bytep row, png_colorp palette, png_bytep trans, int num_trans));
PNG_EXTERN void png_do_expand PNGARG((png_row_infop row_info,
   png_bytep row, png_color_16p trans_value));
#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));

#if defined(PNG_READ_bKGD_SUPPORTED)
PNG_EXTERN void png_handle_bKGD PNGARG((png_structp png_ptr, png_infop info_ptr,
   png_uint_32 length));
#endif

#if defined(PNG_READ_cHRM_SUPPORTED)
PNG_EXTERN void png_handle_cHRM PNGARG((png_structp png_ptr, png_infop info_ptr,
   png_uint_32 length));
#endif

#if defined(PNG_READ_gAMA_SUPPORTED)
PNG_EXTERN void png_handle_gAMA PNGARG((png_structp png_ptr, png_infop info_ptr,
   png_uint_32 length));
#endif

#if defined(PNG_READ_hIST_SUPPORTED)
PNG_EXTERN void png_handle_hIST PNGARG((png_structp png_ptr, png_infop info_ptr,
   png_uint_32 length));
#endif

#if defined(PNG_READ_iCCP_SUPPORTED)
extern void png_handle_iCCP PNGARG((png_structp png_ptr, png_infop info_ptr,
   png_uint_32 length));
#endif /* PNG_READ_iCCP_SUPPORTED */

#if defined(PNG_READ_iTXt_SUPPORTED)
PNG_EXTERN void png_handle_iTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
   png_uint_32 length));
#endif

#if defined(PNG_READ_oFFs_SUPPORTED)
PNG_EXTERN void png_handle_oFFs PNGARG((png_structp png_ptr, png_infop info_ptr,
   png_uint_32 length));
#endif

#if defined(PNG_READ_pCAL_SUPPORTED)
PNG_EXTERN void png_handle_pCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
   png_uint_32 length));
#endif

#if defined(PNG_READ_pHYs_SUPPORTED)
PNG_EXTERN void png_handle_pHYs PNGARG((png_structp png_ptr, png_infop info_ptr,
   png_uint_32 length));
#endif

#if defined(PNG_READ_sBIT_SUPPORTED)
PNG_EXTERN void png_handle_sBIT PNGARG((png_structp png_ptr, png_infop info_ptr,
   png_uint_32 length));
#endif

#if defined(PNG_READ_sCAL_SUPPORTED)
PNG_EXTERN void png_handle_sCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
   png_uint_32 length));
#endif

#if defined(PNG_READ_sPLT_SUPPORTED)
extern void png_handle_sPLT PNGARG((png_structp png_ptr, png_infop info_ptr,
   png_uint_32 length));
#endif /* PNG_READ_sPLT_SUPPORTED */

#if defined(PNG_READ_sRGB_SUPPORTED)
PNG_EXTERN void png_handle_sRGB PNGARG((png_structp png_ptr, png_infop info_ptr,
   png_uint_32 length));
#endif

#if defined(PNG_READ_tEXt_SUPPORTED)
PNG_EXTERN void png_handle_tEXt PNGARG((png_structp png_ptr, png_infop info_ptr,
   png_uint_32 length));
#endif

#if defined(PNG_READ_tIME_SUPPORTED)
PNG_EXTERN void png_handle_tIME PNGARG((png_structp png_ptr, png_infop info_ptr,
   png_uint_32 length));
#endif

#if defined(PNG_READ_tRNS_SUPPORTED)
PNG_EXTERN void png_handle_tRNS PNGARG((png_structp png_ptr, png_infop info_ptr,
   png_uint_32 length));
#endif

#if defined(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_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));
#if defined(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
#if defined(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
#if defined(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

#if defined(PNG_MMX_CODE_SUPPORTED)
/* png.c */ /* PRIVATE */
PNG_EXTERN void png_init_mmx_flags PNGARG((png_structp png_ptr));
#endif

/* Maintainer: Put new private prototypes here ^ and in libpngpf.3 */

#ifdef PNG_READ_SUPPORTED
/* Prior to libpng-1.0.9, this block was in pngasmrd.h */

/* These are the default thresholds before the MMX code kicks in; if either
 * rowbytes or bitdepth is below the threshold, plain C code is used.  These
 * can be overridden at runtime via the png_set_mmx_thresholds() call in
 * libpng 1.2.0 and later.  The values below were chosen by Intel.
 */

#ifndef PNG_MMX_ROWBYTES_THRESHOLD_DEFAULT
#  define PNG_MMX_ROWBYTES_THRESHOLD_DEFAULT  128  /*  >=  */
#endif
#ifndef PNG_MMX_BITDEPTH_THRESHOLD_DEFAULT
#  define PNG_MMX_BITDEPTH_THRESHOLD_DEFAULT  9    /*  >=  */   
#endif

/* Set this in the makefile for VC++ on Pentium, not here. */
/* Platform must be Pentium.  Makefile must assemble and load pngvcrd.c .
 * MMX will be detected at run time and used if present.
 */
#ifdef PNG_USE_PNGVCRD
#  define PNG_HAVE_MMX_COMBINE_ROW
#  define PNG_HAVE_MMX_READ_INTERLACE
#  define PNG_HAVE_MMX_READ_FILTER_ROW
#endif

/* Set this in the makefile for gcc/as on Pentium, not here. */
/* Platform must be Pentium.  Makefile must assemble and load pnggccrd.c .
 * MMX will be detected at run time and used if present.
 */
#ifdef PNG_USE_PNGGCCRD
#  define PNG_HAVE_MMX_COMBINE_ROW
#  define PNG_HAVE_MMX_READ_INTERLACE
#  define PNG_HAVE_MMX_READ_FILTER_ROW
#endif
/* - see pnggccrd.c for info about what is currently enabled */

#endif /* PNG_READ_SUPPORTED */

#ifdef __cplusplus
}
#endif

#endif /* PNG_VERSION_INFO_ONLY */
#endif /* PNGPRIV_H */