2 /* pngstruct.h - header file for PNG reference library
4 * Copyright (c) 1998-2012 Glenn Randers-Pehrson
5 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
6 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
8 * Last changed in libpng 1.5.9 [February 18, 2012]
10 * This code is released under the libpng license.
11 * For conditions of distribution and use, see the disclaimer
12 * and license in png.h
15 /* The structure that holds the information to read and write PNG files.
16 * The only people who need to care about what is inside of this are the
17 * people who will be modifying the library for their own special needs.
18 * It should NOT be accessed directly by an application.
23 /* zlib.h defines the structure z_stream, an instance of which is included
24 * in this structure and is required for decompressing the LZ compressed
31 #ifdef PNG_SETJMP_SUPPORTED
32 jmp_buf longjmp_buffer
; /* used in png_error */
33 png_longjmp_ptr longjmp_fn
;/* setjmp non-local goto function. */
35 png_error_ptr error_fn
; /* function for printing errors and aborting */
36 #ifdef PNG_WARNINGS_SUPPORTED
37 png_error_ptr warning_fn
; /* function for printing warnings */
39 png_voidp error_ptr
; /* user supplied struct for error functions */
40 png_rw_ptr write_data_fn
; /* function for writing output data */
41 png_rw_ptr read_data_fn
; /* function for reading input data */
42 png_voidp io_ptr
; /* ptr to application struct for I/O functions */
44 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
45 png_user_transform_ptr read_user_transform_fn
; /* user read transform */
48 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
49 png_user_transform_ptr write_user_transform_fn
; /* user write transform */
52 /* These were added in libpng-1.0.2 */
53 #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
54 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
55 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
56 png_voidp user_transform_ptr
; /* user supplied struct for user transform */
57 png_byte user_transform_depth
; /* bit depth of user transformed pixels */
58 png_byte user_transform_channels
; /* channels in user transformed pixels */
62 png_uint_32 mode
; /* tells us where we are in the PNG file */
63 png_uint_32 flags
; /* flags indicating various things to libpng */
64 png_uint_32 transformations
; /* which transformations to perform */
66 z_stream zstream
; /* pointer to decompression structure (below) */
67 png_bytep zbuf
; /* buffer for zlib */
68 uInt zbuf_size
; /* size of zbuf (typically 65536) */
69 #ifdef PNG_WRITE_SUPPORTED
71 /* Added in 1.5.4: state to keep track of whether the zstream has been
72 * initialized and if so whether it is for IDAT or some other chunk.
74 #define PNG_ZLIB_UNINITIALIZED 0
75 #define PNG_ZLIB_FOR_IDAT 1
76 #define PNG_ZLIB_FOR_TEXT 2 /* anything other than IDAT */
77 #define PNG_ZLIB_USE_MASK 3 /* bottom two bits */
78 #define PNG_ZLIB_IN_USE 4 /* a flag value */
80 png_uint_32 zlib_state
; /* State of zlib initialization */
81 /* End of material added at libpng 1.5.4 */
83 int zlib_level
; /* holds zlib compression level */
84 int zlib_method
; /* holds zlib compression method */
85 int zlib_window_bits
; /* holds zlib compression window bits */
86 int zlib_mem_level
; /* holds zlib compression memory level */
87 int zlib_strategy
; /* holds zlib compression strategy */
89 /* Added at libpng 1.5.4 */
90 #if defined(PNG_WRITE_COMPRESSED_TEXT_SUPPORTED) || \
91 defined(PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED)
92 int zlib_text_level
; /* holds zlib compression level */
93 int zlib_text_method
; /* holds zlib compression method */
94 int zlib_text_window_bits
; /* holds zlib compression window bits */
95 int zlib_text_mem_level
; /* holds zlib compression memory level */
96 int zlib_text_strategy
; /* holds zlib compression strategy */
98 /* End of material added at libpng 1.5.4 */
100 png_uint_32 width
; /* width of image in pixels */
101 png_uint_32 height
; /* height of image in pixels */
102 png_uint_32 num_rows
; /* number of rows in current pass */
103 png_uint_32 usr_width
; /* width of row at start of write */
104 png_size_t rowbytes
; /* size of row in bytes */
105 png_uint_32 iwidth
; /* width of current interlaced row in pixels */
106 png_uint_32 row_number
; /* current row in interlace pass */
107 png_uint_32 chunk_name
; /* PNG_CHUNK() id of current chunk */
108 png_bytep prev_row
; /* buffer to save previous (unfiltered) row.
109 * This is a pointer into big_prev_row
111 png_bytep row_buf
; /* buffer to save current (unfiltered) row.
112 * This is a pointer into big_row_buf
114 png_bytep sub_row
; /* buffer to save "sub" row when filtering */
115 png_bytep up_row
; /* buffer to save "up" row when filtering */
116 png_bytep avg_row
; /* buffer to save "avg" row when filtering */
117 png_bytep paeth_row
; /* buffer to save "Paeth" row when filtering */
118 png_size_t info_rowbytes
; /* Added in 1.5.4: cache of updated row bytes */
120 png_uint_32 idat_size
; /* current IDAT size for read */
121 png_uint_32 crc
; /* current chunk CRC value */
122 png_colorp palette
; /* palette from the input file */
123 png_uint_16 num_palette
; /* number of color entries in palette */
125 /* Added at libpng-1.5.10 */
126 #ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
127 int num_palette_max
; /* maximum palette index found in IDAT */
130 png_uint_16 num_trans
; /* number of transparency values */
131 png_byte compression
; /* file compression type (always 0) */
132 png_byte filter
; /* file filter type (always 0) */
133 png_byte interlaced
; /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
134 png_byte pass
; /* current interlace pass (0 - 6) */
135 png_byte do_filter
; /* row filter flags (see PNG_FILTER_ below ) */
136 png_byte color_type
; /* color type of file */
137 png_byte bit_depth
; /* bit depth of file */
138 png_byte usr_bit_depth
; /* bit depth of users row: write only */
139 png_byte pixel_depth
; /* number of bits per pixel */
140 png_byte channels
; /* number of channels in file */
141 png_byte usr_channels
; /* channels at start of write: write only */
142 png_byte sig_bytes
; /* magic bytes read/written from start of file */
143 png_byte maximum_pixel_depth
;
144 /* pixel depth used for the row buffers */
145 png_byte transformed_pixel_depth
;
146 /* pixel depth after read/write transforms */
147 png_byte io_chunk_string
[5];
148 /* string name of chunk */
150 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
151 png_uint_16 filler
; /* filler bytes for pixel expansion */
154 #if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
155 defined(PNG_READ_ALPHA_MODE_SUPPORTED)
156 png_byte background_gamma_type
;
157 png_fixed_point background_gamma
;
158 png_color_16 background
; /* background color in screen gamma space */
159 #ifdef PNG_READ_GAMMA_SUPPORTED
160 png_color_16 background_1
; /* background normalized to gamma 1.0 */
162 #endif /* PNG_bKGD_SUPPORTED */
164 #ifdef PNG_WRITE_FLUSH_SUPPORTED
165 png_flush_ptr output_flush_fn
; /* Function for flushing output */
166 png_uint_32 flush_dist
; /* how many rows apart to flush, 0 - no flush */
167 png_uint_32 flush_rows
; /* number of rows written since last flush */
170 #ifdef PNG_READ_GAMMA_SUPPORTED
171 int gamma_shift
; /* number of "insignificant" bits in 16-bit gamma */
172 png_fixed_point gamma
; /* file gamma value */
173 png_fixed_point screen_gamma
; /* screen gamma value (display_exponent) */
175 png_bytep gamma_table
; /* gamma table for 8-bit depth files */
176 png_uint_16pp gamma_16_table
; /* gamma table for 16-bit depth files */
177 #if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
178 defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \
179 defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
180 png_bytep gamma_from_1
; /* converts from 1.0 to screen */
181 png_bytep gamma_to_1
; /* converts from file to 1.0 */
182 png_uint_16pp gamma_16_from_1
; /* converts from 1.0 to screen */
183 png_uint_16pp gamma_16_to_1
; /* converts from file to 1.0 */
184 #endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */
187 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_sBIT_SUPPORTED)
188 png_color_8 sig_bit
; /* significant bits in each available channel */
191 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
192 png_color_8 shift
; /* shift for significant bit tranformation */
195 #if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \
196 || defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
197 png_bytep trans_alpha
; /* alpha values for paletted files */
198 png_color_16 trans_color
; /* transparent color for non-paletted files */
201 png_read_status_ptr read_row_fn
; /* called after each row is decoded */
202 png_write_status_ptr write_row_fn
; /* called after each row is encoded */
203 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
204 png_progressive_info_ptr info_fn
; /* called after header data fully read */
205 png_progressive_row_ptr row_fn
; /* called after a prog. row is decoded */
206 png_progressive_end_ptr end_fn
; /* called after image is complete */
207 png_bytep save_buffer_ptr
; /* current location in save_buffer */
208 png_bytep save_buffer
; /* buffer for previously read data */
209 png_bytep current_buffer_ptr
; /* current location in current_buffer */
210 png_bytep current_buffer
; /* buffer for recently used data */
211 png_uint_32 push_length
; /* size of current input chunk */
212 png_uint_32 skip_length
; /* bytes to skip in input data */
213 png_size_t save_buffer_size
; /* amount of data now in save_buffer */
214 png_size_t save_buffer_max
; /* total size of save_buffer */
215 png_size_t buffer_size
; /* total amount of available input data */
216 png_size_t current_buffer_size
; /* amount of data now in current_buffer */
217 int process_mode
; /* what push library is currently doing */
218 int cur_palette
; /* current push library palette index */
220 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
222 #if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
223 /* For the Borland special 64K segment handler */
224 png_bytepp offset_table_ptr
;
225 png_bytep offset_table
;
226 png_uint_16 offset_table_number
;
227 png_uint_16 offset_table_count
;
228 png_uint_16 offset_table_count_free
;
231 #ifdef PNG_READ_QUANTIZE_SUPPORTED
232 png_bytep palette_lookup
; /* lookup table for quantizing */
233 png_bytep quantize_index
; /* index translation for palette files */
236 #if defined(PNG_READ_QUANTIZE_SUPPORTED) || defined(PNG_hIST_SUPPORTED)
237 png_uint_16p hist
; /* histogram */
240 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
241 png_byte heuristic_method
; /* heuristic for row filter selection */
242 png_byte num_prev_filters
; /* number of weights for previous rows */
243 png_bytep prev_filters
; /* filter type(s) of previous row(s) */
244 png_uint_16p filter_weights
; /* weight(s) for previous line(s) */
245 png_uint_16p inv_filter_weights
; /* 1/weight(s) for previous line(s) */
246 png_uint_16p filter_costs
; /* relative filter calculation cost */
247 png_uint_16p inv_filter_costs
; /* 1/relative filter calculation cost */
250 #ifdef PNG_TIME_RFC1123_SUPPORTED
251 /* This is going to be unused in libpng16 and removed from libpng17 */
252 char time_buffer
[29]; /* String to hold RFC 1123 time text */
255 /* New members added in libpng-1.0.6 */
257 png_uint_32 free_me
; /* flags items libpng is responsible for freeing */
259 #ifdef PNG_USER_CHUNKS_SUPPORTED
260 png_voidp user_chunk_ptr
;
261 png_user_chunk_ptr read_user_chunk_fn
; /* user read chunk handler */
264 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
266 png_bytep chunk_list
;
269 #ifdef PNG_READ_sRGB_SUPPORTED
270 /* Added in 1.5.5 to record an sRGB chunk in the png. */
274 /* New members added in libpng-1.0.3 */
275 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
276 png_byte rgb_to_gray_status
;
277 /* Added in libpng 1.5.5 to record setting of coefficients: */
278 png_byte rgb_to_gray_coefficients_set
;
279 /* These were changed from png_byte in libpng-1.0.6 */
280 png_uint_16 rgb_to_gray_red_coeff
;
281 png_uint_16 rgb_to_gray_green_coeff
;
282 /* deleted in 1.5.5: rgb_to_gray_blue_coeff; */
285 /* New member added in libpng-1.0.4 (renamed in 1.0.9) */
286 #if defined(PNG_MNG_FEATURES_SUPPORTED)
287 /* Changed from png_byte to png_uint_32 at version 1.2.0 */
288 png_uint_32 mng_features_permitted
;
291 /* New member added in libpng-1.0.9, ifdef'ed out in 1.0.12, enabled in 1.2.0 */
292 #ifdef PNG_MNG_FEATURES_SUPPORTED
293 png_byte filter_type
;
296 /* New members added in libpng-1.2.0 */
298 /* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */
299 #ifdef PNG_USER_MEM_SUPPORTED
300 png_voidp mem_ptr
; /* user supplied struct for mem functions */
301 png_malloc_ptr malloc_fn
; /* function for allocating memory */
302 png_free_ptr free_fn
; /* function for freeing memory */
305 /* New member added in libpng-1.0.13 and 1.2.0 */
306 png_bytep big_row_buf
; /* buffer to save current (unfiltered) row */
308 #ifdef PNG_READ_QUANTIZE_SUPPORTED
309 /* The following three members were added at version 1.0.14 and 1.2.4 */
310 png_bytep quantize_sort
; /* working sort array */
311 png_bytep index_to_palette
; /* where the original index currently is
313 png_bytep palette_to_index
; /* which original index points to this
317 /* New members added in libpng-1.0.16 and 1.2.6 */
318 png_byte compression_type
;
320 #ifdef PNG_USER_LIMITS_SUPPORTED
321 png_uint_32 user_width_max
;
322 png_uint_32 user_height_max
;
324 /* Added in libpng-1.4.0: Total number of sPLT, text, and unknown
325 * chunks that can be stored (0 means unlimited).
327 png_uint_32 user_chunk_cache_max
;
329 /* Total memory that a zTXt, sPLT, iTXt, iCCP, or unknown chunk
330 * can occupy when decompressed. 0 means unlimited.
332 png_alloc_size_t user_chunk_malloc_max
;
335 /* New member added in libpng-1.0.25 and 1.2.17 */
336 #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
337 /* Storage for unknown chunk that the library doesn't recognize. */
338 png_unknown_chunk unknown_chunk
;
341 /* New member added in libpng-1.2.26 */
342 png_size_t old_big_row_buf_size
;
344 /* New member added in libpng-1.2.30 */
345 png_charp chunkdata
; /* buffer for reading chunk data */
347 #ifdef PNG_IO_STATE_SUPPORTED
348 /* New member added in libpng-1.4.0 */
349 png_uint_32 io_state
;
352 /* New member added in libpng-1.5.6 */
353 png_bytep big_prev_row
;
355 void (*read_filter
[PNG_FILTER_VALUE_LAST
-1])(png_row_infop row_info
,
356 png_bytep row
, png_const_bytep prev_row
);
358 #endif /* PNGSTRUCT_H */