png.h

GIS系统支持库Geospatial Data Abstraction Library代码.GDAL is a translator library for raster geospatial dat

#if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \
 || defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
   png_bytep trans;           /* transparency values for paletted files */
   png_color_16 trans_values; /* transparency values for non-paletted files */
#endif

   png_read_status_ptr read_row_fn;   /* called after each row is decoded */
   png_write_status_ptr write_row_fn; /* called after each row is encoded */
#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
   png_progressive_info_ptr info_fn; /* called after header data fully read */
   png_progressive_row_ptr row_fn;   /* called after each prog. row is decoded */
   png_progressive_end_ptr end_fn;   /* called after image is complete */
   png_bytep save_buffer_ptr;        /* current location in save_buffer */
   png_bytep save_buffer;            /* buffer for previously read data */
   png_bytep current_buffer_ptr;     /* current location in current_buffer */
   png_bytep current_buffer;         /* buffer for recently used data */
   png_uint_32 push_length;          /* size of current input chunk */
   png_uint_32 skip_length;          /* bytes to skip in input data */
   png_size_t save_buffer_size;      /* amount of data now in save_buffer */
   png_size_t save_buffer_max;       /* total size of save_buffer */
   png_size_t buffer_size;           /* total amount of available input data */
   png_size_t current_buffer_size;   /* amount of data now in current_buffer */
   int process_mode;                 /* what push library is currently doing */
   int cur_palette;                  /* current push library palette index */

#  if defined(PNG_TEXT_SUPPORTED)
     png_size_t current_text_size;   /* current size of text input data */
     png_size_t current_text_left;   /* how much text left to read in input */
     png_charp current_text;         /* current text chunk buffer */
     png_charp current_text_ptr;     /* current location in current_text */
#  endif /* PNG_PROGRESSIVE_READ_SUPPORTED && PNG_TEXT_SUPPORTED */

#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */

#if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
/* for the Borland special 64K segment handler */
   png_bytepp offset_table_ptr;
   png_bytep offset_table;
   png_uint_16 offset_table_number;
   png_uint_16 offset_table_count;
   png_uint_16 offset_table_count_free;
#endif

#if defined(PNG_READ_DITHER_SUPPORTED)
   png_bytep palette_lookup;         /* lookup table for dithering */
   png_bytep dither_index;           /* index translation for palette files */
#endif

#if defined(PNG_READ_DITHER_SUPPORTED) || defined(PNG_hIST_SUPPORTED)
   png_uint_16p hist;                /* histogram */
#endif

#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
   png_byte heuristic_method;        /* heuristic for row filter selection */
   png_byte num_prev_filters;        /* number of weights for previous rows */
   png_bytep prev_filters;           /* filter type(s) of previous row(s) */
   png_uint_16p filter_weights;      /* weight(s) for previous line(s) */
   png_uint_16p inv_filter_weights;  /* 1/weight(s) for previous line(s) */
   png_uint_16p filter_costs;        /* relative filter calculation cost */
   png_uint_16p inv_filter_costs;    /* 1/relative filter calculation cost */
#endif

#if defined(PNG_TIME_RFC1123_SUPPORTED)
   png_charp time_buffer;            /* String to hold RFC 1123 time text */
#endif

/* New members added in libpng-1.0.6 */

#ifdef PNG_FREE_ME_SUPPORTED
   png_uint_32 free_me;       /* flags items libpng is responsible for freeing */
#endif

#if defined(PNG_USER_CHUNKS_SUPPORTED)
   png_voidp user_chunk_ptr;
   png_user_chunk_ptr read_user_chunk_fn; /* user read chunk handler */
#endif

#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
   int num_chunk_list;
   png_bytep chunk_list;
#endif

/* New members added in libpng-1.0.3 */
#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
   png_byte rgb_to_gray_status;
   /* These were changed from png_byte in libpng-1.0.6 */
   png_uint_16 rgb_to_gray_red_coeff;
   png_uint_16 rgb_to_gray_green_coeff;
   png_uint_16 rgb_to_gray_blue_coeff;
#endif

/* New member added in libpng-1.0.4 (renamed in 1.0.9) */
#if defined(PNG_MNG_FEATURES_SUPPORTED) || \
    defined(PNG_READ_EMPTY_PLTE_SUPPORTED) || \
    defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
/* changed from png_byte to png_uint_32 at version 1.2.0 */
#ifdef PNG_1_0_X
   png_byte mng_features_permitted;
#else
   png_uint_32 mng_features_permitted;
#endif /* PNG_1_0_X */
#endif

/* New member added in libpng-1.0.7 */
#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
   png_fixed_point int_gamma;
#endif

/* New member added in libpng-1.0.9, ifdef'ed out in 1.0.12, enabled in 1.2.0 */
#if defined(PNG_MNG_FEATURES_SUPPORTED)
   png_byte filter_type;
#endif

#if defined(PNG_1_0_X) || (defined(PNG_DEBUG) && defined(PNG_USE_PNGGCCRD))
/* New member added in libpng-1.0.10, ifdef'ed out in 1.2.0 */
   png_uint_32 row_buf_size;
#endif

/* New members added in libpng-1.2.0 */
#if !defined(PNG_1_0_X) && defined(PNG_ASSEMBLER_CODE_SUPPORTED)
   png_byte     mmx_bitdepth_threshold;
   png_uint_32  mmx_rowbytes_threshold;
   png_uint_32  asm_flags;
#endif

/* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */
#ifdef PNG_USER_MEM_SUPPORTED
   png_voidp mem_ptr;                /* user supplied struct for mem functions */
   png_malloc_ptr malloc_fn;         /* function for allocating memory */
   png_free_ptr free_fn;             /* function for freeing memory */
#endif

/* New member added in libpng-1.0.13 and 1.2.0 */
   png_bytep big_row_buf;         /* buffer to save current (unfiltered) row */

#if defined(PNG_READ_DITHER_SUPPORTED)
/* The following three members were added at version 1.0.14 and 1.2.4 */
   png_bytep dither_sort;            /* working sort array */
   png_bytep index_to_palette;       /* where the original index currently is */
                                     /* in the palette */
   png_bytep palette_to_index;       /* which original index points to this */
                                     /* palette color */
#endif

/* New members added in libpng-1.0.16 and 1.2.6 */
   png_byte compression_type;

#ifdef PNG_SET_USER_LIMITS_SUPPORTED
   png_uint_32 user_width_max;
   png_uint_32 user_height_max;
#endif

};


/* This triggers a compiler error in png.c, if png.c and png.h
 * do not agree upon the version number.
 */
typedef png_structp version_1_2_8;

typedef png_struct FAR * FAR * png_structpp;

/* Here are the function definitions most commonly used.  This is not
 * the place to find out how to use libpng.  See libpng.txt for the
 * full explanation, see example.c for the summary.  This just provides
 * a simple one line description of the use of each function.
 */

/* Returns the version number of the library */
extern PNG_EXPORT(png_uint_32,png_access_version_number) PNGARG((void));

/* Tell lib we have already handled the first <num_bytes> magic bytes.
 * Handling more than 8 bytes from the beginning of the file is an error.
 */
extern PNG_EXPORT(void,png_set_sig_bytes) PNGARG((png_structp png_ptr,
   int num_bytes));

/* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
 * PNG file.  Returns zero if the supplied bytes match the 8-byte PNG
 * signature, and non-zero otherwise.  Having num_to_check == 0 or
 * start > 7 will always fail (ie return non-zero).
 */
extern PNG_EXPORT(int,png_sig_cmp) PNGARG((png_bytep sig, png_size_t start,
   png_size_t num_to_check));

/* Simple signature checking function.  This is the same as calling
 * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n).
 */
extern PNG_EXPORT(int,png_check_sig) PNGARG((png_bytep sig, int num));

/* Allocate and initialize png_ptr struct for reading, and any other memory. */
extern PNG_EXPORT(png_structp,png_create_read_struct)
   PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
   png_error_ptr error_fn, png_error_ptr warn_fn));

/* Allocate and initialize png_ptr struct for writing, and any other memory */
extern PNG_EXPORT(png_structp,png_create_write_struct)
   PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
   png_error_ptr error_fn, png_error_ptr warn_fn));

#ifdef PNG_WRITE_SUPPORTED
extern PNG_EXPORT(png_uint_32,png_get_compression_buffer_size)
   PNGARG((png_structp png_ptr));
#endif

#ifdef PNG_WRITE_SUPPORTED
extern PNG_EXPORT(void,png_set_compression_buffer_size)
   PNGARG((png_structp png_ptr, png_uint_32 size));
#endif

/* Reset the compression stream */
extern PNG_EXPORT(int,png_reset_zstream) PNGARG((png_structp png_ptr));

/* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */
#ifdef PNG_USER_MEM_SUPPORTED
extern PNG_EXPORT(png_structp,png_create_read_struct_2)
   PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
   png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
   png_malloc_ptr malloc_fn, png_free_ptr free_fn));
extern PNG_EXPORT(png_structp,png_create_write_struct_2)
   PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
   png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
   png_malloc_ptr malloc_fn, png_free_ptr free_fn));
#endif

/* Write a PNG chunk - size, type, (optional) data, CRC. */
extern PNG_EXPORT(void,png_write_chunk) PNGARG((png_structp png_ptr,
   png_bytep chunk_name, png_bytep data, png_size_t length));

/* Write the start of a PNG chunk - length and chunk name. */
extern PNG_EXPORT(void,png_write_chunk_start) PNGARG((png_structp png_ptr,
   png_bytep chunk_name, png_uint_32 length));

/* Write the data of a PNG chunk started with png_write_chunk_start(). */
extern PNG_EXPORT(void,png_write_chunk_data) PNGARG((png_structp png_ptr,
   png_bytep data, png_size_t length));

/* Finish a chunk started with png_write_chunk_start() (includes CRC). */
extern PNG_EXPORT(void,png_write_chunk_end) PNGARG((png_structp png_ptr));

/* Allocate and initialize the info structure */
extern PNG_EXPORT(png_infop,png_create_info_struct)
   PNGARG((png_structp png_ptr));

/* Initialize the info structure (old interface - DEPRECATED) */
extern PNG_EXPORT(void,png_info_init) PNGARG((png_infop info_ptr));
#undef png_info_init
#define png_info_init(info_ptr) png_info_init_3(&info_ptr,\
    png_sizeof(png_info));
extern PNG_EXPORT(void,png_info_init_3) PNGARG((png_infopp info_ptr,
    png_size_t png_info_struct_size));

/* Writes all the PNG information before the image. */
extern PNG_EXPORT(void,png_write_info_before_PLTE) PNGARG((png_structp png_ptr,
   png_infop info_ptr));
extern PNG_EXPORT(void,png_write_info) PNGARG((png_structp png_ptr,
   png_infop info_ptr));

#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
/* read the information before the actual image data. */
extern PNG_EXPORT(void,png_read_info) PNGARG((png_structp png_ptr,
   png_infop info_ptr));
#endif

#if defined(PNG_TIME_RFC1123_SUPPORTED)
extern PNG_EXPORT(png_charp,png_convert_to_rfc1123)
   PNGARG((png_structp png_ptr, png_timep ptime));
#endif

#if !defined(_WIN32_WCE)
/* "time.h" functions are not supported on WindowsCE */
#if defined(PNG_WRITE_tIME_SUPPORTED)
/* convert from a struct tm to png_time */
extern PNG_EXPORT(void,png_convert_from_struct_tm) PNGARG((png_timep ptime,
   struct tm FAR * ttime));

/* convert from time_t to png_time.  Uses gmtime() */
extern PNG_EXPORT(void,png_convert_from_time_t) PNGARG((png_timep ptime,
   time_t ttime));
#endif /* PNG_WRITE_tIME_SUPPORTED */
#endif /* _WIN32_WCE */

#if defined(PNG_READ_EXPAND_SUPPORTED)
/* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
extern PNG_EXPORT(void,png_set_expand) PNGARG((png_structp png_ptr));
extern PNG_EXPORT(void,png_set_gray_1_2_4_to_8) PNGARG((png_structp png_ptr));
extern PNG_EXPORT(void,png_set_palette_to_rgb) PNGARG((png_structp png_ptr));
extern PNG_EXPORT(void,png_set_tRNS_to_alpha) PNGARG((png_structp png_ptr));
#endif

#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
/* Use blue, green, red order for pixels. */
extern PNG_EXPORT(void,png_set_bgr) PNGARG((png_structp png_ptr));
#endif

#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
/* Expand the grayscale to 24-bit RGB if necessary. */
extern PNG_EXPORT(void,png_set_gray_to_rgb) PNGARG((png_structp png_p