| |
| /* pngstruct.h - header file for PNG reference library |
| * |
| * Copyright (c) 1998-2014 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 */ |
