libpng/pngstruct.h
John Bowler 808ea281a4 [libpng17] Corrected Android builds and corrected libpng.vers with symbol
prefixing. This adds an API to set optimization options externally,
providing an alternative and general solution for the non-portable
run-time tests used by the ARM Neon code.  It also makes those tests
compile and link on Android.  The order of settings vs options in
pnglibconf.h is reversed to allow settings to depend on options and
options can now set (or override) the defaults for settings.
2013-03-03 21:29:36 -06:00

561 lines
22 KiB
C

/* pngstruct.h - header file for PNG reference library
*
* Copyright (c) 1998-2013 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 1.7.0 [(PENDING RELEASE)]
*
* This code is released under the libpng license.
* For conditions of distribution and use, see the disclaimer
* and license in png.h
*/
/* The structure that holds the information to read and write PNG files.
* The only people who need to care about what is inside of this are the
* people who will be modifying the library for their own special needs.
* It should NOT be accessed directly by an application.
*/
#ifndef PNGSTRUCT_H
#define PNGSTRUCT_H
/* zlib.h defines the structure z_stream, an instance of which is included
* in this structure and is required for decompressing the LZ compressed
* data in PNG files.
*/
#ifndef ZLIB_CONST
/* We must ensure that zlib uses 'const' in declarations. */
# define ZLIB_CONST
#endif
#include PNG_ZLIB_HEADER
#ifdef const
/* zlib.h sometimes #defines const to nothing, undo this. */
# undef const
#endif
/* zlib.h has mediocre z_const use before 1.2.6, this stuff is for compatibility
* with older builds.
*/
#if ZLIB_VERNUM < 0x1260
# define PNGZ_MSG_CAST(s) png_constcast(char*,s)
# define PNGZ_INPUT_CAST(b) png_constcast(png_bytep,b)
#else
# define PNGZ_MSG_CAST(s) (s)
# define PNGZ_INPUT_CAST(b) (b)
#endif
/* 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
* maximum for size_t. The value can be overridden 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
#ifdef PNG_WRITE_SUPPORTED
/* The type of a compression buffer list used by the write code. */
typedef struct png_compression_buffer
{
struct png_compression_buffer *next;
png_byte output[1]; /* actually zbuf_size */
} png_compression_buffer, *png_compression_bufferp;
#define PNG_COMPRESSION_BUFFER_SIZE(pp)\
(offsetof(png_compression_buffer, output) + (pp)->zbuffer_size)
#endif
/* Colorspace support; structures used in png_struct, png_info and in internal
* functions to hold and communicate information about the color space.
*
* PNG_COLORSPACE_SUPPORTED is only required if the application will perform
* colorspace corrections, otherwise all the colorspace information can be
* skipped and the size of libpng can be reduced (significantly) by compiling
* out the colorspace support.
*/
#ifdef PNG_COLORSPACE_SUPPORTED
/* The chromaticities of the red, green and blue colorants and the chromaticity
* of the corresponding white point (i.e. of rgb(1.0,1.0,1.0)).
*/
typedef struct png_xy
{
png_fixed_point redx, redy;
png_fixed_point greenx, greeny;
png_fixed_point bluex, bluey;
png_fixed_point whitex, whitey;
} png_xy;
/* The same data as above but encoded as CIE XYZ values. When this data comes
* from chromaticities the sum of the Y values is assumed to be 1.0
*/
typedef struct png_XYZ
{
png_fixed_point red_X, red_Y, red_Z;
png_fixed_point green_X, green_Y, green_Z;
png_fixed_point blue_X, blue_Y, blue_Z;
} png_XYZ;
#endif /* COLORSPACE */
#if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED)
/* A colorspace is all the above plus, potentially, profile information,
* however at present libpng does not use the profile internally so it is only
* stored in the png_info struct (if iCCP is supported.) The rendering intent
* is retained here and is checked.
*
* The file gamma encoding information is also stored here and gamma correction
* is done by libpng, whereas color correction must currently be done by the
* application.
*/
typedef struct png_colorspace
{
#ifdef PNG_GAMMA_SUPPORTED
png_fixed_point gamma; /* File gamma */
#endif
#ifdef PNG_COLORSPACE_SUPPORTED
png_xy end_points_xy; /* End points as chromaticities */
png_XYZ end_points_XYZ; /* End points as CIE XYZ colorant values */
png_uint_16 rendering_intent; /* Rendering intent of a profile */
#endif
/* Flags are always defined to simplify the code. */
png_uint_16 flags; /* As defined below */
} png_colorspace, * PNG_RESTRICT png_colorspacerp;
typedef const png_colorspace * PNG_RESTRICT png_const_colorspacerp;
/* General flags for the 'flags' field */
#define PNG_COLORSPACE_HAVE_GAMMA 0x0001
#define PNG_COLORSPACE_HAVE_ENDPOINTS 0x0002
#define PNG_COLORSPACE_HAVE_INTENT 0x0004
#define PNG_COLORSPACE_FROM_gAMA 0x0008
#define PNG_COLORSPACE_FROM_cHRM 0x0010
#define PNG_COLORSPACE_FROM_sRGB 0x0020
#define PNG_COLORSPACE_ENDPOINTS_MATCH_sRGB 0x0040
#define PNG_COLORSPACE_MATCHES_sRGB 0x0080 /* exact match on profile */
#define PNG_COLORSPACE_RGB_TO_GRAY_SET 0x0100 /* user specified coeffs */
#define PNG_COLORSPACE_INVALID 0x8000
#define PNG_COLORSPACE_CANCEL(flags) (0xffff ^ (flags))
#endif /* COLORSPACE || GAMMA */
struct png_struct_def
{
/* Rearranged in libpng 1.7 to attempt to lessen padding; in general
* (char), (short), (int) and pointer types are kept separate, however
* associated members under the control of the same #define are still
* together.
*/
#ifdef PNG_SETJMP_SUPPORTED
/* jmp_buf can have very high alignment requirements on some systems, so put
* it first (the other setjmp members are later as they are infrequently
* accesed.)
*/
jmp_buf jmp_buf_local;
#endif
/* Next the frequently accessed fields. Many processors perform arithmetic
* in the address pipeline, but frequently the amount of addition or
* subtraction is limited. By putting these fields at the head of png_struct
* the hope is that such processors will generate code that is both smaller
* and faster.
*/
png_colorp palette; /* palette from the input file */
size_t rowbytes; /* size of row in bytes */
size_t info_rowbytes; /* cache of updated row bytes */
png_uint_32 width; /* width of image in pixels */
png_uint_32 height; /* height of image in pixels */
png_uint_32 num_rows; /* number of rows in current pass */
png_uint_32 usr_width; /* width of row at start of write */
png_uint_32 iwidth; /* width of current interlaced row in pixels */
png_uint_32 row_number; /* current row in interlace pass */
png_uint_32 chunk_name; /* PNG_CHUNK() id of current chunk */
png_uint_32 crc; /* current chunk CRC value */
png_uint_32 mode; /* tells us where we are in the PNG file */
png_uint_32 flags; /* flags indicating various things to libpng */
png_uint_32 transformations;/* which transformations to perform */
png_uint_32 zowner; /* ID (chunk type) of zstream owner, 0 if none */
png_uint_32 free_me; /* items libpng is responsible for freeing */
int maximum_pixel_depth; /* pixel depth used for the row buffers */
#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
int num_palette_max; /* maximum palette index found in IDAT */
#endif
png_uint_16 num_palette; /* number of color entries in palette */
png_uint_16 num_trans; /* number of transparency values */
/* Single byte values, typically used either to save space or to hold 1-byte
* values from the PNG chunk specifications.
*/
png_byte compression_type; /* file compression type (always 0) */
png_byte filter; /* file filter type (always 0) */
png_byte interlaced; /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
png_byte pass; /* current interlace pass (0 - 6) */
png_byte do_filter; /* row filter flags (see PNG_FILTER_ below ) */
png_byte color_type; /* color type of file */
png_byte bit_depth; /* bit depth of file */
png_byte pixel_depth; /* number of bits per pixel */
png_byte channels; /* number of channels in file */
png_byte sig_bytes; /* magic bytes read/written from start of file */
png_byte transformed_pixel_depth;
/* pixel depth after read/write transforms */
/* ERROR HANDLING */
#ifdef PNG_SETJMP_SUPPORTED
jmp_buf *jmp_buf_ptr; /* passed to longjmp_fn */
png_longjmp_ptr longjmp_fn; /* setjmp non-local goto function. */
size_t jmp_buf_size; /* size of *jmp_buf_ptr, if allocated */
#endif
/* Error/warning callbacks */
png_error_ptr error_fn; /* print an error message and abort */
#ifdef PNG_WARNINGS_SUPPORTED
png_error_ptr warning_fn; /* print a warning and continue */
#endif
png_voidp error_ptr; /* user supplied data for the above */
/* MEMORY ALLOCATION */
#ifdef PNG_USER_MEM_SUPPORTED
png_malloc_ptr malloc_fn; /* allocate memory */
png_free_ptr free_fn; /* free memory */
png_voidp mem_ptr; /* user supplied data for the above */
#endif
/* IO and BASIC READ/WRITE SUPPORT */
png_voidp io_ptr; /* user supplied data for IO callbacks */
#ifdef PNG_READ_SUPPORTED
png_rw_ptr read_data_fn; /* read some bytes (must succeed) */
png_read_status_ptr read_row_fn; /* called after each row is decoded */
png_bytep read_buffer; /* buffer for reading chunk data */
/* During read the following array is set up to point to the appropriate
* un-filter function, this allows per-image and per-processor optimization.
*/
void (*read_filter[PNG_FILTER_VALUE_LAST-1])(png_row_infop row_info,
png_bytep row, png_const_bytep prev_row);
#if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED)
/* The png_struct colorspace structure is only required on read - on write it
* is in (just) the info_struct.
*/
png_colorspace colorspace;
#endif
#endif /* PNG_READ_SUPPORTED */
#ifdef PNG_SET_USER_LIMITS_SUPPORTED
png_uint_32 user_width_max; /* Maximum width on read */
png_uint_32 user_height_max; /* Maximum height on read */
/* Total memory that a single zTXt, sPLT, iTXt, iCCP, or unknown chunk
* can occupy when decompressed. 0 means unlimited. This field is a counter
* - it is decremented as memory is allocated.
*/
png_alloc_size_t user_chunk_malloc_max;
#endif
#ifdef PNG_USER_LIMITS_SUPPORTED
/* limit on total *number* of sPLT, text and unknown chunks that can be
* stored. 0 means unlimited. This field is a counter - it is decremented
* as chunks are encountered.
*/
png_uint_32 user_chunk_cache_max;
#endif
/* The progressive reader gets passed data and calls application handling
* functions when appropriate.
*/
#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 a row is decoded */
png_progressive_end_ptr end_fn; /* called after image is complete */
/* Progressive read control data */
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 */
size_t save_buffer_size; /* amount of data now in save_buffer */
size_t save_buffer_max; /* total size of save_buffer */
size_t buffer_size; /* total amount of available input data */
size_t current_buffer_size; /* amount of data now in current_buffer */
png_uint_32 push_length; /* size of current input chunk */
png_uint_32 skip_length; /* bytes to skip in input data */
int process_mode; /* what push library is currently doing */
int cur_palette; /* current push library palette index */
#endif
#ifdef PNG_WRITE_SUPPORTED
png_rw_ptr write_data_fn;/* write some bytes (must succeed) */
png_write_status_ptr write_row_fn; /* called after each row is encoded */
#endif
#ifdef PNG_WRITE_FLUSH_SUPPORTED
png_flush_ptr output_flush_fn; /* Function for flushing output */
png_uint_32 flush_dist; /* how many rows apart to flush, 0 - no flush */
png_uint_32 flush_rows; /* number of rows written since last flush */
#endif
#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
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 */
png_byte heuristic_method; /* heuristic for row filter selection */
png_byte num_prev_filters; /* number of weights for previous rows */
#endif
#ifdef PNG_WRITE_SUPPORTED
png_byte usr_bit_depth; /* bit depth of users row */
png_byte usr_channels; /* channels at start of write */
#endif
#ifdef PNG_IO_STATE_SUPPORTED
png_uint_32 io_state; /* tells the app read/write progress */
#endif
/* ROW BUFFERS
*
* Members that hold pointers to the decompressed image rows.
*/
png_bytep row_buf; /* buffer for the current (unfiltered) row */
#if defined(PNG_WRITE_FILTER_SUPPORTED) || defined(PNG_READ_SUPPORTED)
png_bytep prev_row; /* buffer to save the previous (unfiltered) row */
#endif
#ifdef PNG_READ_SUPPORTED
/* The row_buf and prev_row pointers are misaligned so that the start of the
* row - after the filter byte - is aligned, the 'big_' pointers record the
* original allocated pointer.
*/
png_bytep big_row_buf;
png_bytep big_prev_row;
size_t big_row_buf_size; /* Actual size of both */
#endif
#ifdef PNG_WRITE_SUPPORTED
/* This is somewhat excessive, there is no obvious reason on write to
* allocate a buffer for each possible filtered row, only for the one being
* tested and the current best.
*
* TODO: fix this
*/
png_bytep sub_row; /* buffer to save "sub" row when filtering */
png_bytep up_row; /* buffer to save "up" row when filtering */
png_bytep avg_row; /* buffer to save "avg" row when filtering */
png_bytep paeth_row; /* buffer to save "Paeth" row when filtering */
#endif
/* UNKNOWN CHUNK HANDLING */
/* TODO: this is excessively complicated, there are multiple ways of doing
* the same thing. It should be cleaned up, possibly by finding out which
* APIs applications really use.
*/
#ifdef PNG_USER_CHUNKS_SUPPORTED
/* General purpose pointer for all user/unknown chunk handling; points to
* application supplied data for use in the read_user_chunk_fn callback
* (currently there is no write side support - the write side must use the
* set_unknown_chunks interface.)
*/
png_voidp user_chunk_ptr;
#endif
#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
/* This is called back from the unknown chunk handling */
png_user_chunk_ptr read_user_chunk_fn; /* user read chunk handler */
#endif
#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
/* Temporary storage for unknown chunk that the library doesn't recognize,
* used while reading the chunk.
*/
png_unknown_chunk unknown_chunk;
#endif
#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
png_bytep chunk_list; /* List of png_byte[5]; the textual chunk name
* followed by a PNG_HANDLE_* byte */
int unknown_default; /* As PNG_HANDLE_* */
unsigned int num_chunk_list; /* Number of entries in the list */
#endif
/* USER TRANSFORM SUPPORT */
#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
png_user_transform_ptr read_user_transform_fn; /* user read transform */
#endif
#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
png_user_transform_ptr write_user_transform_fn; /* user write transform */
#endif
#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
png_voidp user_transform_ptr; /* user supplied data for the above */
png_byte user_transform_depth; /* bit depth of user transformed pixels */
png_byte user_transform_channels; /* channels in user transformed pixels */
#endif
/* READ TRANSFORM SUPPORT
*
* Quite a lot of things can be done to the original image data on read, and
* most of these are configurable. The data required by the configurable
* read transforms should be stored here. The png_color_16 and png_color_8
* structures have low alignment requirements and odd sizes, so may cause
* misalignment when present. Member alignment is as follows:
*
* png_color_16 png_uint_16
* png_color_8 png_byte
*/
/* GAMMA/BACKGROUND/ALPHA-MODE/RGB-TO-GRAY/tRNS/sBIT
*
* These things are all interrelated because they need some or all of the
* gamma tables. Some attempt has been made below to order these members by
* size, so that as little padding as possible is required.
*/
#ifdef PNG_READ_GAMMA_SUPPORTED
png_bytep gamma_table; /* gamma table for 8-bit depth files */
png_uint_16p gamma_16_table; /* gamma table for 16-bit depth files */
#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
defined(PNG_READ_ALPHA_MODE_SUPPORTED) ||\
defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
png_bytep gamma_from_1; /* converts from 1.0 to screen */
png_uint_16p gamma_to_1; /* converts from file to 1.0 */
png_uint_16p gamma_16_from_1; /* converts from 1.0 to screen */
png_uint_16p gamma_16_to_1; /* converts from file to 1.0 */
#endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */
#endif /* PNG_READ_GAMMA_SUPPORTED */
#if defined(PNG_READ_tRNS_SUPPORTED) || \
defined(PNG_READ_BACKGROUND_SUPPORTED) || \
defined(PNG_READ_EXPAND_SUPPORTED)
png_bytep trans_alpha; /* alpha values for paletted files */
#endif
/* Integer values */
#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
defined(PNG_READ_ALPHA_MODE_SUPPORTED)
png_fixed_point background_gamma;
#endif
#ifdef PNG_READ_GAMMA_SUPPORTED
png_fixed_point screen_gamma; /* screen gamma value (display_exponent) */
int gamma_shift; /* number of "insignificant" bits in 16-bit gamma */
#endif
/* png_color_16 */
#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
defined(PNG_READ_ALPHA_MODE_SUPPORTED)
png_color_16 background; /* background color in screen gamma space */
png_color_16 background_1; /* background normalized to gamma 1.0 */
#endif
#if defined(PNG_READ_tRNS_SUPPORTED) || \
defined(PNG_READ_BACKGROUND_SUPPORTED) || \
defined(PNG_READ_EXPAND_SUPPORTED)
png_color_16 trans_color; /* transparent color for non-paletted files */
#endif
/* png_uint_16 */
#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
png_uint_16 rgb_to_gray_red_coeff;
png_uint_16 rgb_to_gray_green_coeff;
/* The blue coefficient is calculated from the above */
#endif
/* png_color_8 */
#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_sBIT_SUPPORTED)
png_color_8 sig_bit; /* significant bits in each available channel */
#endif
/* png_byte */
#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
defined(PNG_READ_ALPHA_MODE_SUPPORTED)
png_byte background_gamma_type;
#endif
#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
png_byte rgb_to_gray_status;
#endif
/* SHIFT - both READ_SHIFT and WRITE_SHIFT */
#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
png_color_8 shift; /* shift for significant bit tranformation */
#endif
/* FILLER SUPPORT (pixel expansion or read, contraction on write) */
#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
png_uint_16 filler; /* filler bytes for pixel expansion */
#endif
/* QUANTIZE (convert to color-mapped) */
#ifdef PNG_READ_QUANTIZE_SUPPORTED
png_bytep palette_lookup; /* lookup table for quantizing */
png_bytep quantize_index; /* index translation for palette files */
png_bytep quantize_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
/* MNG SUPPORT */
#ifdef PNG_MNG_FEATURES_SUPPORTED
png_uint_32 mng_features_permitted;
png_byte filter_type;
#endif
/* Options */
#ifdef PNG_SET_OPTION_SUPPORTED
png_byte options; /* On/off state (up to 4 options) */
#endif
/* COMPRESSION AND DECOMPRESSION SUPPORT.
*
* zlib expects a 'zstream' as the fundamental control structure, it allows
* all the parameters to be passed as one pointer.
*/
z_stream zstream; /* decompression structure */
#ifdef PNG_READ_SUPPORTED
/* These, and IDAT_read_size below, control how much input and output (at
* most) is available to zlib.
*/
png_uint_32 idat_size; /* current IDAT size for read */
png_alloc_size_t read_buffer_size; /* current size of the buffer */
#endif
#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
int zlib_text_level; /* holds zlib compression level */
int zlib_text_method; /* holds zlib compression method */
int zlib_text_window_bits; /* holds zlib compression window bits */
int zlib_text_mem_level; /* holds zlib compression memory level */
int zlib_text_strategy; /* holds zlib compression strategy */
#endif
#ifdef PNG_WRITE_SUPPORTED
int zlib_level; /* holds zlib compression level */
int zlib_method; /* holds zlib compression method */
int zlib_window_bits; /* holds zlib compression window bits */
int zlib_mem_level; /* holds zlib compression memory level */
int zlib_strategy; /* holds zlib compression strategy */
int zlib_set_level; /* Actual values set into the zstream on write */
int zlib_set_method;
int zlib_set_window_bits;
int zlib_set_mem_level;
int zlib_set_strategy;
png_compression_bufferp zbuffer_list; /* Created on demand during write */
uInt zbuffer_size; /* size of the actual zlib buffer */
#endif
#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
uInt IDAT_read_size; /* limit on read buffer size for IDAT */
#endif
};
#endif /* PNGSTRUCT_H */