-extern PNG_EXPORT(png_bytep,png_get_signature) PNGARG((png_structp png_ptr,
-png_infop info_ptr));
-
-#if defined(PNG_READ_bKGD_SUPPORTED)
-extern PNG_EXPORT(png_uint_32,png_get_bKGD) PNGARG((png_structp png_ptr,
- png_infop info_ptr, png_color_16p *background));
-#endif /* PNG_READ_bKGD_SUPPORTED */
-
-#if defined(PNG_READ_bKGD_SUPPORTED) || defined(PNG_WRITE_bKGD_SUPPORTED)
-extern PNG_EXPORT(void,png_set_bKGD) PNGARG((png_structp png_ptr,
- png_infop info_ptr, png_color_16p background));
-#endif /* PNG_READ_bKGD_SUPPORTED || PNG_WRITE_bKGD_SUPPORTED */
-
-#if defined(PNG_READ_cHRM_SUPPORTED)
-extern PNG_EXPORT(png_uint_32,png_get_cHRM) PNGARG((png_structp png_ptr,
- png_infop info_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_READ_cHRM_SUPPORTED */
-
-#if defined(PNG_READ_cHRM_SUPPORTED) || defined(PNG_WRITE_cHRM_SUPPORTED)
-extern PNG_EXPORT(void,png_set_cHRM) PNGARG((png_structp png_ptr,
- png_infop info_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_READ_cHRM_SUPPORTED || PNG_WRITE_cHRM_SUPPORTED */
-
-#if defined(PNG_READ_gAMA_SUPPORTED)
-extern PNG_EXPORT(png_uint_32,png_get_gAMA) PNGARG((png_structp png_ptr,
- png_infop info_ptr, double *file_gamma));
-#endif /* PNG_READ_gAMA_SUPPORTED */
-
-#if defined(PNG_READ_gAMA_SUPPORTED) || defined(PNG_WRITE_gAMA_SUPPORTED)
-extern PNG_EXPORT(void,png_set_gAMA) PNGARG((png_structp png_ptr,
- png_infop info_ptr, double file_gamma));
-#endif /* PNG_READ_gAMA_SUPPORTED || PNG_WRITE_gAMA_SUPPORTED */
-
-#if defined(PNG_READ_hIST_SUPPORTED)
-extern PNG_EXPORT(png_uint_32,png_get_hIST) PNGARG((png_structp png_ptr,
- png_infop info_ptr, png_uint_16p *hist));
-#endif /* PNG_READ_hIST_SUPPORTED */
-
-#if defined(PNG_READ_hIST_SUPPORTED) || defined(PNG_WRITE_hIST_SUPPORTED)
-extern PNG_EXPORT(void,png_set_hIST) PNGARG((png_structp png_ptr,
- png_infop info_ptr, png_uint_16p hist));
-#endif /* PNG_READ_hIST_SUPPORTED || PNG_WRITE_hIST_SUPPORTED */
-
-extern PNG_EXPORT(png_uint_32,png_get_IHDR) PNGARG((png_structp png_ptr,
- png_infop info_ptr, png_uint_32 *width, png_uint_32 *height,
- int *bit_depth, int *color_type, int *interlace_type,
- int *compression_type, int *filter_type));
-
-extern PNG_EXPORT(void,png_set_IHDR) PNGARG((png_structp png_ptr,
- png_infop info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth,
- int color_type, int interlace_type, int compression_type, int filter_type));
-
-#if defined(PNG_READ_oFFs_SUPPORTED)
-extern PNG_EXPORT(png_uint_32,png_get_oFFs) PNGARG((png_structp png_ptr,
- png_infop info_ptr, png_uint_32 *offset_x, png_uint_32 *offset_y,
- int *unit_type));
-#endif /* PNG_READ_oFFs_SUPPORTED */
-
-#if defined(PNG_READ_oFFs_SUPPORTED) || defined(PNG_WRITE_oFFs_SUPPORTED)
-extern PNG_EXPORT(void,png_set_oFFs) PNGARG((png_structp png_ptr,
- png_infop info_ptr, png_uint_32 offset_x, png_uint_32 offset_y,
- int unit_type));
-#endif /* PNG_READ_oFFs_SUPPORTED || PNG_WRITE_oFFs_SUPPORTED */
-
-#if defined(PNG_READ_pCAL_SUPPORTED)
-extern PNG_EXPORT(png_uint_32,png_get_pCAL) PNGARG((png_structp png_ptr,
- png_infop info_ptr, png_charp *purpose, png_int_32 *X0, png_int_32 *X1,
- int *type, int *nparams, png_charp *units, png_charpp *params));
-#endif /* PNG_READ_pCAL_SUPPORTED */
-
-#if defined(PNG_READ_pCAL_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED)
-extern PNG_EXPORT(void,png_set_pCAL) PNGARG((png_structp png_ptr,
- png_infop info_ptr, png_charp purpose, png_int_32 X0, png_int_32 X1,
- int type, int nparams, png_charp units, png_charpp params));
-#endif /* PNG_READ_pCAL_SUPPORTED || PNG_WRITE_pCAL_SUPPORTED */
-
-#if defined(PNG_READ_pHYs_SUPPORTED)
-extern PNG_EXPORT(png_uint_32,png_get_pHYs) PNGARG((png_structp png_ptr,
- png_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type));
-#endif /* PNG_READ_pHYs_SUPPORTED */
-
-#if defined(PNG_READ_pHYs_SUPPORTED) || defined(PNG_WRITE_pHYs_SUPPORTED)
-extern PNG_EXPORT(void,png_set_pHYs) PNGARG((png_structp png_ptr,
- png_infop info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type));
-#endif /* PNG_READ_pHYs_SUPPORTED || PNG_WRITE_pHYs_SUPPORTED */
-
-extern PNG_EXPORT(png_uint_32,png_get_PLTE) PNGARG((png_structp png_ptr,
- png_infop info_ptr, png_colorp *palette, int *num_palette));
-
-extern PNG_EXPORT(void,png_set_PLTE) PNGARG((png_structp png_ptr,
- png_infop info_ptr, png_colorp palette, int num_palette));
-
-#if defined(PNG_READ_sBIT_SUPPORTED)
-extern PNG_EXPORT(png_uint_32,png_get_sBIT) PNGARG((png_structp png_ptr,
- png_infop info_ptr, png_color_8p *sig_bit));
-#endif /* PNG_READ_sBIT_SUPPORTED */
-
-#if defined(PNG_READ_sBIT_SUPPORTED) || defined(PNG_WRITE_sBIT_SUPPORTED)
-extern PNG_EXPORT(void,png_set_sBIT) PNGARG((png_structp png_ptr,
- png_infop info_ptr, png_color_8p sig_bit));
-#endif /* PNG_READ_sBIT_SUPPORTED || PNG_WRITE_sBIT_SUPPORTED */
-
-#if defined(PNG_READ_sRGB_SUPPORTED)
-extern PNG_EXPORT(png_uint_32,png_get_sRGB) PNGARG((png_structp png_ptr,
- png_infop info_ptr, int *intent));
-#endif /* PNG_READ_sRGB_SUPPORTED */
-
-#if defined(PNG_READ_sRGB_SUPPORTED) || defined(PNG_WRITE_sRGB_SUPPORTED)
-extern PNG_EXPORT(void,png_set_sRGB) PNGARG((png_structp png_ptr,
- png_infop info_ptr, int intent));
-extern PNG_EXPORT(void,png_set_sRGB_gAMA_and_cHRM) PNGARG((png_structp png_ptr,
- png_infop info_ptr, int intent));
-#endif /* PNG_READ_sRGB_SUPPORTED || PNG_WRITE_sRGB_SUPPORTED */
-
-#if defined(PNG_READ_tEXt_SUPPORTED) || defined(PNG_READ_zTXt_SUPPORTED)
-/* png_get_text also returns the number of text chunks in text_ptr */
-extern PNG_EXPORT(png_uint_32,png_get_text) PNGARG((png_structp png_ptr,
- png_infop info_ptr, png_textp *text_ptr, int *num_text));
-#endif /* PNG_READ_tEXt_SUPPORTED || PNG_READ_zTXt_SUPPORTED */
-
-#if defined(PNG_READ_tEXt_SUPPORTED) || defined(PNG_WRITE_tEXt_SUPPORTED) || \
- defined(PNG_READ_zTXt_SUPPORTED) || defined(PNG_WRITE_zTXt_SUPPORTED)
-extern PNG_EXPORT(void,png_set_text) PNGARG((png_structp png_ptr,
- png_infop info_ptr, png_textp text_ptr, int num_text));
-#endif /* PNG_READ_tEXt_SUPPORTED || PNG_WRITE_tEXt_SUPPORTED ||
- PNG_READ_zTXt_SUPPORTED || PNG_WRITE_zTXt_SUPPORTED */
-
-#if defined(PNG_READ_tIME_SUPPORTED)
-extern PNG_EXPORT(png_uint_32,png_get_tIME) PNGARG((png_structp png_ptr,
- png_infop info_ptr, png_timep *mod_time));
-#endif /* PNG_READ_tIME_SUPPORTED */
-
-#if defined(PNG_READ_tIME_SUPPORTED) || defined(PNG_WRITE_tIME_SUPPORTED)
-extern PNG_EXPORT(void,png_set_tIME) PNGARG((png_structp png_ptr,
- png_infop info_ptr, png_timep mod_time));
-#endif /* PNG_READ_tIME_SUPPORTED || PNG_WRITE_tIME_SUPPORTED */
-
-#if defined(PNG_READ_tRNS_SUPPORTED)
-extern PNG_EXPORT(png_uint_32,png_get_tRNS) PNGARG((png_structp png_ptr,
- png_infop info_ptr, png_bytep *trans, int *num_trans,
- png_color_16p *trans_values));
-#endif /* PNG_READ_tRNS_SUPPORTED */
-
-#if defined(PNG_READ_tRNS_SUPPORTED) || defined(PNG_WRITE_tRNS_SUPPORTED)
-extern PNG_EXPORT(void,png_set_tRNS) PNGARG((png_structp png_ptr,
- png_infop info_ptr, png_bytep trans, int num_trans,
- png_color_16p trans_values));
-#endif /* PNG_READ_tRNS_SUPPORTED || PNG_WRITE_tRNS_SUPPORTED */
-
-/* Define PNG_DEBUG at compile time for debugging information. Higher
- * numbers for PNG_DEBUG mean more debugging information. This has
- * only been added since version 0.95 so it is not implemented throughout
- * libpng yet, but more support will be added as needed.
- */
-#if (PNG_DEBUG > 0)
-#ifdef PNG_NO_STDIO
-#include <stdio.h>
-#endif
-#ifndef PNG_DEBUG_FILE
-#define PNG_DEBUG_FILE stderr
-#endif /* PNG_DEBUG_FILE */
-
-#define png_debug(l,m) if (PNG_DEBUG > l) \
- fprintf(PNG_DEBUG_FILE,"%s"m,(l==1 ? "\t" : \
- (l==2 ? "\t\t":(l==3 ? "\t\t\t":""))))
-#define png_debug1(l,m,p1) if (PNG_DEBUG > l) \
- fprintf(PNG_DEBUG_FILE,"%s"m,(l==1 ? "\t" : \
- (l==2 ? "\t\t":(l==3 ? "\t\t\t":""))),p1)
-#define png_debug2(l,m,p1,p2) if (PNG_DEBUG > l) \
- fprintf(PNG_DEBUG_FILE,"%s"m,(l==1 ? "\t" : \
- (l==2 ? "\t\t":(l==3 ? "\t\t\t":""))),p1,p2)
-#else
-#define png_debug(l, m)
-#define png_debug1(l, m, p1)
-#define png_debug2(l, m, p1, p2)
-#endif /* (PNG_DEBUG > 0) */
-
-/* These next 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.
- */
-
-#if defined(PNG_INTERNAL)
-
-/* Various modes of operation. Note that after an init, mode is set to
- * zero automatically when the structure is created.
- */
-#define PNG_BEFORE_IHDR 0x00
-#define PNG_HAVE_IHDR 0x01
-#define PNG_HAVE_PLTE 0x02
-#define PNG_HAVE_IDAT 0x04
-#define PNG_AFTER_IDAT 0x08
-#define PNG_HAVE_IEND 0x10
-#define PNG_HAVE_gAMA 0x20
-#define PNG_HAVE_cHRM 0x40
-#define PNG_HAVE_sRGB 0x80
-
-/* push model modes */
-#define PNG_READ_SIG_MODE 0
-#define PNG_READ_CHUNK_MODE 1
-#define PNG_READ_IDAT_MODE 2
-#define PNG_SKIP_MODE 3
-#define PNG_READ_tEXt_MODE 4
-#define PNG_READ_zTXt_MODE 5
-#define PNG_READ_DONE_MODE 6
-#define PNG_ERROR_MODE 7
-
-/* 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
-#define PNG_RGB_TO_GRAY 0x0200 /* Not currently implemented */
-#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 0x8000
-#define PNG_PACKSWAP 0x10000L
-#define PNG_SWAP_ALPHA 0x20000L
-#define PNG_STRIP_ALPHA 0x40000L
-#define PNG_INVERT_ALPHA 0x80000L
-#define PNG_USER_TRANSFORM 0x100000L
-
-/* 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_PALETTE 0x1000
-#define PNG_FLAG_FREE_TRANS 0x2000
-#define PNG_FLAG_FREE_HIST 0x4000
-#define PNG_FLAG_HAVE_CHUNK_HEADER 0x8000L
-#define PNG_FLAG_WROTE_tIME 0x10000L
-
-#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)))
-
-/* 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. */
-extern png_byte FARDATA png_sig[8];
-
-/* Constant strings for known chunk types. If you need to add a chunk,
- * add a string holding the name here. See png.c for more details. We
- * can't selectively include these, since we still check for chunk in the
- * wrong locations with these labels.
- */
-extern png_byte FARDATA png_IHDR[5];
-extern png_byte FARDATA png_IDAT[5];
-extern png_byte FARDATA png_IEND[5];
-extern png_byte FARDATA png_PLTE[5];
-extern png_byte FARDATA png_bKGD[5];
-extern png_byte FARDATA png_cHRM[5];
-extern png_byte FARDATA png_gAMA[5];
-extern png_byte FARDATA png_hIST[5];
-extern png_byte FARDATA png_oFFs[5];
-extern png_byte FARDATA png_pCAL[5];
-extern png_byte FARDATA png_pHYs[5];
-extern png_byte FARDATA png_sBIT[5];
-extern png_byte FARDATA png_sRGB[5];
-extern png_byte FARDATA png_tEXt[5];
-extern png_byte FARDATA png_tIME[5];
-extern png_byte FARDATA png_tRNS[5];
-extern png_byte FARDATA png_zTXt[5];
-
-#endif /* PNG_NO_EXTERN */
-
-/* Inline macros to do direct reads of bytes from the input buffer. These
- * require that you are using an architecture that uses PNG byte ordering
- * (MSB first) and supports unaligned data storage. I think that PowerPC
- * in big-endian mode and 680x0 are the only ones that will support this.
- * The x86 line of processors definitely do not. The png_get_int_32()
- * routine also assumes we are using two's complement format for negative
- * values, which is almost certainly true.
- */
-#if defined(PNG_READ_BIG_ENDIAN_SUPPORTED)
-#if defined(PNG_READ_pCAL_SUPPORTED)
-#define png_get_int_32(buf) ( *((png_int_32p) (buf)))
-#endif /* PNG_READ_pCAL_SUPPORTED */
-#define png_get_uint_32(buf) ( *((png_uint_32p) (buf)))
-#define png_get_uint_16(buf) ( *((png_uint_16p) (buf)))
-#else
-#if defined(PNG_READ_pCAL_SUPPORTED)
-PNG_EXTERN png_int_32 png_get_int_32 PNGARG((png_bytep buf));
-#endif /* PNG_READ_pCAL_SUPPORTED */
-PNG_EXTERN png_uint_32 png_get_uint_32 PNGARG((png_bytep buf));
-PNG_EXTERN png_uint_16 png_get_uint_16 PNGARG((png_bytep buf));
-#endif /* PNG_BIG_ENDIAN_GET_SUPPORTED */
-
-/* Initialize png_ptr struct for reading, and allocate any other memory.
- * (old interface - NOT DLL EXPORTED).
- */
-extern void png_read_init PNGARG((png_structp png_ptr));
-
-/* Initialize png_ptr struct for writing, and allocate any other memory.
- * (old interface - NOT DLL EXPORTED).
- */
-extern void png_write_init PNGARG((png_structp png_ptr));
-
-/* 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));
-
-/* 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. */
-PNG_EXTERN voidpf png_zalloc PNGARG((voidpf png_ptr, uInt items, uInt size));
-
-/* function to free memory for zlib */
-PNG_EXTERN void png_zfree PNGARG((voidpf png_ptr, voidpf ptr));
-
-/* reset the CRC variable */
-PNG_EXTERN void png_reset_crc PNGARG((png_structp png_ptr));