-/* 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_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
-#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
-
-/* 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 */
-#define PNG_ADD_ALPHA 0x1000000L /* Added to libpng-1.2.7 */
-
-/* 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_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 ? \
- ((width) * (((png_uint_32)(pixel_bits)) >> 3)) : \
- (( ((width) * ((png_uint_32)(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
-#define png_sig png_sig_bytes(NULL)
-#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_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 */
-
-
-/* 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_pCAL_SUPPORTED) || defined(PNG_oFFs_SUPPORTED)
-# define png_get_int_32(buf) ( *((png_int_32p) (buf)))
-# endif
-# define png_get_uint_32(buf) ( *((png_uint_32p) (buf)))
-# define png_get_uint_16(buf) ( *((png_uint_16p) (buf)))
-#else
-# if defined(PNG_pCAL_SUPPORTED) || defined(PNG_oFFs_SUPPORTED)
-PNG_EXTERN png_int_32 png_get_int_32 PNGARG((png_bytep buf));
-# endif
-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_READ_BIG_ENDIAN_SUPPORTED */
-/* RN: This define is blatent hack to get png to (hopefully)
- link on OSX 10.2 and earlier versions of 10.3 due to an
- Apple linking bug introduced in 10.2 */
-#define png_get_uint_31 wxpng_get_uint_31
-PNG_EXTERN png_uint_32 png_get_uint_31 PNGARG((png_structp png_ptr,
- png_bytep buf));
-/* Initialize png_ptr struct for reading, and allocate any other memory.
- * (old interface - DEPRECATED - use png_create_read_struct instead).
- */
-extern PNG_EXPORT(void,png_read_init) PNGARG((png_structp png_ptr));
-#undef png_read_init
-#define png_read_init(png_ptr) png_read_init_3(&png_ptr, \
- PNG_LIBPNG_VER_STRING, png_sizeof(png_struct));
-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_read_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));
-
-/* Initialize png_ptr struct for writing, and allocate any other memory.
- * (old interface - DEPRECATED - use png_create_write_struct instead).
- */
-extern PNG_EXPORT(void,png_write_init) PNGARG((png_structp png_ptr));
-#undef png_write_init
-#define png_write_init(png_ptr) png_write_init_3(&png_ptr, \
- PNG_LIBPNG_VER_STRING, png_sizeof(png_struct));
-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));
-
-#ifndef PNG_1_0_X
-/* 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));
-
-#ifdef PNG_SIZE_T
-/* Function to convert a sizeof an item to png_sizeof item */
- PNG_EXTERN png_size_t PNGAPI png_convert_size PNGARG((size_t size));
-#endif
-
-/* 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));