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libpng
author Ritor1
date Mon, 17 Mar 2014 01:21:55 +0600
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2295:6fd03869f65c 2296:6e178010fc29
1
2 /* pngstruct.h - header file for PNG reference library
3 *
4 * Copyright (c) 1998-2013 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.)
7 *
8 * Last changed in libpng 1.6.1 [March 28, 2013]
9 *
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
13 */
14
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.
19 */
20
21 #ifndef PNGSTRUCT_H
22 #define PNGSTRUCT_H
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
25 * data in PNG files.
26 */
27 #ifndef ZLIB_CONST
28 /* We must ensure that zlib uses 'const' in declarations. */
29 # define ZLIB_CONST
30 #endif
31 #include "../../lib/zlib/zlib.h"
32 #ifdef const
33 /* zlib.h sometimes #defines const to nothing, undo this. */
34 # undef const
35 #endif
36
37 /* zlib.h has mediocre z_const use before 1.2.6, this stuff is for compatibility
38 * with older builds.
39 */
40 #if ZLIB_VERNUM < 0x1260
41 # define PNGZ_MSG_CAST(s) png_constcast(char*,s)
42 # define PNGZ_INPUT_CAST(b) png_constcast(png_bytep,b)
43 #else
44 # define PNGZ_MSG_CAST(s) (s)
45 # define PNGZ_INPUT_CAST(b) (b)
46 #endif
47
48 /* zlib.h declares a magic type 'uInt' that limits the amount of data that zlib
49 * can handle at once. This type need be no larger than 16 bits (so maximum of
50 * 65535), this define allows us to discover how big it is, but limited by the
51 * maximuum for png_size_t. The value can be overriden in a library build
52 * (pngusr.h, or set it in CPPFLAGS) and it works to set it to a considerably
53 * lower value (e.g. 255 works). A lower value may help memory usage (slightly)
54 * and may even improve performance on some systems (and degrade it on others.)
55 */
56 #ifndef ZLIB_IO_MAX
57 # define ZLIB_IO_MAX ((uInt)-1)
58 #endif
59
60 #ifdef PNG_WRITE_SUPPORTED
61 /* The type of a compression buffer list used by the write code. */
62 typedef struct png_compression_buffer
63 {
64 struct png_compression_buffer *next;
65 png_byte output[1]; /* actually zbuf_size */
66 } png_compression_buffer, *png_compression_bufferp;
67
68 #define PNG_COMPRESSION_BUFFER_SIZE(pp)\
69 (offsetof(png_compression_buffer, output) + (pp)->zbuffer_size)
70 #endif
71
72 /* Colorspace support; structures used in png_struct, png_info and in internal
73 * functions to hold and communicate information about the color space.
74 *
75 * PNG_COLORSPACE_SUPPORTED is only required if the application will perform
76 * colorspace corrections, otherwise all the colorspace information can be
77 * skipped and the size of libpng can be reduced (significantly) by compiling
78 * out the colorspace support.
79 */
80 #ifdef PNG_COLORSPACE_SUPPORTED
81 /* The chromaticities of the red, green and blue colorants and the chromaticity
82 * of the corresponding white point (i.e. of rgb(1.0,1.0,1.0)).
83 */
84 typedef struct png_xy
85 {
86 png_fixed_point redx, redy;
87 png_fixed_point greenx, greeny;
88 png_fixed_point bluex, bluey;
89 png_fixed_point whitex, whitey;
90 } png_xy;
91
92 /* The same data as above but encoded as CIE XYZ values. When this data comes
93 * from chromaticities the sum of the Y values is assumed to be 1.0
94 */
95 typedef struct png_XYZ
96 {
97 png_fixed_point red_X, red_Y, red_Z;
98 png_fixed_point green_X, green_Y, green_Z;
99 png_fixed_point blue_X, blue_Y, blue_Z;
100 } png_XYZ;
101 #endif /* COLORSPACE */
102
103 #if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED)
104 /* A colorspace is all the above plus, potentially, profile information,
105 * however at present libpng does not use the profile internally so it is only
106 * stored in the png_info struct (if iCCP is supported.) The rendering intent
107 * is retained here and is checked.
108 *
109 * The file gamma encoding information is also stored here and gamma correction
110 * is done by libpng, whereas color correction must currently be done by the
111 * application.
112 */
113 typedef struct png_colorspace
114 {
115 #ifdef PNG_GAMMA_SUPPORTED
116 png_fixed_point gamma; /* File gamma */
117 #endif
118
119 #ifdef PNG_COLORSPACE_SUPPORTED
120 png_xy end_points_xy; /* End points as chromaticities */
121 png_XYZ end_points_XYZ; /* End points as CIE XYZ colorant values */
122 png_uint_16 rendering_intent; /* Rendering intent of a profile */
123 #endif
124
125 /* Flags are always defined to simplify the code. */
126 png_uint_16 flags; /* As defined below */
127 } png_colorspace, * PNG_RESTRICT png_colorspacerp;
128
129 typedef const png_colorspace * PNG_RESTRICT png_const_colorspacerp;
130
131 /* General flags for the 'flags' field */
132 #define PNG_COLORSPACE_HAVE_GAMMA 0x0001
133 #define PNG_COLORSPACE_HAVE_ENDPOINTS 0x0002
134 #define PNG_COLORSPACE_HAVE_INTENT 0x0004
135 #define PNG_COLORSPACE_FROM_gAMA 0x0008
136 #define PNG_COLORSPACE_FROM_cHRM 0x0010
137 #define PNG_COLORSPACE_FROM_sRGB 0x0020
138 #define PNG_COLORSPACE_ENDPOINTS_MATCH_sRGB 0x0040
139 #define PNG_COLORSPACE_MATCHES_sRGB 0x0080 /* exact match on profile */
140 #define PNG_COLORSPACE_INVALID 0x8000
141 #define PNG_COLORSPACE_CANCEL(flags) (0xffff ^ (flags))
142 #endif /* COLORSPACE || GAMMA */
143
144 struct png_struct_def
145 {
146 #ifdef PNG_SETJMP_SUPPORTED
147 jmp_buf jmp_buf_local; /* New name in 1.6.0 for jmp_buf in png_struct */
148 png_longjmp_ptr longjmp_fn;/* setjmp non-local goto function. */
149 jmp_buf *jmp_buf_ptr; /* passed to longjmp_fn */
150 size_t jmp_buf_size; /* size of the above, if allocated */
151 #endif
152 png_error_ptr error_fn; /* function for printing errors and aborting */
153 #ifdef PNG_WARNINGS_SUPPORTED
154 png_error_ptr warning_fn; /* function for printing warnings */
155 #endif
156 png_voidp error_ptr; /* user supplied struct for error functions */
157 png_rw_ptr write_data_fn; /* function for writing output data */
158 png_rw_ptr read_data_fn; /* function for reading input data */
159 png_voidp io_ptr; /* ptr to application struct for I/O functions */
160
161 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
162 png_user_transform_ptr read_user_transform_fn; /* user read transform */
163 #endif
164
165 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
166 png_user_transform_ptr write_user_transform_fn; /* user write transform */
167 #endif
168
169 /* These were added in libpng-1.0.2 */
170 #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
171 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
172 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
173 png_voidp user_transform_ptr; /* user supplied struct for user transform */
174 png_byte user_transform_depth; /* bit depth of user transformed pixels */
175 png_byte user_transform_channels; /* channels in user transformed pixels */
176 #endif
177 #endif
178
179 png_uint_32 mode; /* tells us where we are in the PNG file */
180 png_uint_32 flags; /* flags indicating various things to libpng */
181 png_uint_32 transformations; /* which transformations to perform */
182
183 png_uint_32 zowner; /* ID (chunk type) of zstream owner, 0 if none */
184 z_stream zstream; /* decompression structure */
185
186 #ifdef PNG_WRITE_SUPPORTED
187 png_compression_bufferp zbuffer_list; /* Created on demand during write */
188 uInt zbuffer_size; /* size of the actual buffer */
189
190 int zlib_level; /* holds zlib compression level */
191 int zlib_method; /* holds zlib compression method */
192 int zlib_window_bits; /* holds zlib compression window bits */
193 int zlib_mem_level; /* holds zlib compression memory level */
194 int zlib_strategy; /* holds zlib compression strategy */
195 #endif
196 /* Added at libpng 1.5.4 */
197 #ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
198 int zlib_text_level; /* holds zlib compression level */
199 int zlib_text_method; /* holds zlib compression method */
200 int zlib_text_window_bits; /* holds zlib compression window bits */
201 int zlib_text_mem_level; /* holds zlib compression memory level */
202 int zlib_text_strategy; /* holds zlib compression strategy */
203 #endif
204 /* End of material added at libpng 1.5.4 */
205 /* Added at libpng 1.6.0 */
206 #ifdef PNG_WRITE_SUPPORTED
207 int zlib_set_level; /* Actual values set into the zstream on write */
208 int zlib_set_method;
209 int zlib_set_window_bits;
210 int zlib_set_mem_level;
211 int zlib_set_strategy;
212 #endif
213
214 png_uint_32 width; /* width of image in pixels */
215 png_uint_32 height; /* height of image in pixels */
216 png_uint_32 num_rows; /* number of rows in current pass */
217 png_uint_32 usr_width; /* width of row at start of write */
218 png_size_t rowbytes; /* size of row in bytes */
219 png_uint_32 iwidth; /* width of current interlaced row in pixels */
220 png_uint_32 row_number; /* current row in interlace pass */
221 png_uint_32 chunk_name; /* PNG_CHUNK() id of current chunk */
222 png_bytep prev_row; /* buffer to save previous (unfiltered) row.
223 * This is a pointer into big_prev_row
224 */
225 png_bytep row_buf; /* buffer to save current (unfiltered) row.
226 * This is a pointer into big_row_buf
227 */
228 #ifdef PNG_WRITE_SUPPORTED
229 png_bytep sub_row; /* buffer to save "sub" row when filtering */
230 png_bytep up_row; /* buffer to save "up" row when filtering */
231 png_bytep avg_row; /* buffer to save "avg" row when filtering */
232 png_bytep paeth_row; /* buffer to save "Paeth" row when filtering */
233 #endif
234 png_size_t info_rowbytes; /* Added in 1.5.4: cache of updated row bytes */
235
236 png_uint_32 idat_size; /* current IDAT size for read */
237 png_uint_32 crc; /* current chunk CRC value */
238 png_colorp palette; /* palette from the input file */
239 png_uint_16 num_palette; /* number of color entries in palette */
240
241 /* Added at libpng-1.5.10 */
242 #ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
243 int num_palette_max; /* maximum palette index found in IDAT */
244 #endif
245
246 png_uint_16 num_trans; /* number of transparency values */
247 png_byte compression; /* file compression type (always 0) */
248 png_byte filter; /* file filter type (always 0) */
249 png_byte interlaced; /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
250 png_byte pass; /* current interlace pass (0 - 6) */
251 png_byte do_filter; /* row filter flags (see PNG_FILTER_ below ) */
252 png_byte color_type; /* color type of file */
253 png_byte bit_depth; /* bit depth of file */
254 png_byte usr_bit_depth; /* bit depth of users row: write only */
255 png_byte pixel_depth; /* number of bits per pixel */
256 png_byte channels; /* number of channels in file */
257 #ifdef PNG_WRITE_SUPPORTED
258 png_byte usr_channels; /* channels at start of write: write only */
259 #endif
260 png_byte sig_bytes; /* magic bytes read/written from start of file */
261 png_byte maximum_pixel_depth;
262 /* pixel depth used for the row buffers */
263 png_byte transformed_pixel_depth;
264 /* pixel depth after read/write transforms */
265 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
266 png_uint_16 filler; /* filler bytes for pixel expansion */
267 #endif
268
269 #if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
270 defined(PNG_READ_ALPHA_MODE_SUPPORTED)
271 png_byte background_gamma_type;
272 png_fixed_point background_gamma;
273 png_color_16 background; /* background color in screen gamma space */
274 #ifdef PNG_READ_GAMMA_SUPPORTED
275 png_color_16 background_1; /* background normalized to gamma 1.0 */
276 #endif
277 #endif /* PNG_bKGD_SUPPORTED */
278
279 #ifdef PNG_WRITE_FLUSH_SUPPORTED
280 png_flush_ptr output_flush_fn; /* Function for flushing output */
281 png_uint_32 flush_dist; /* how many rows apart to flush, 0 - no flush */
282 png_uint_32 flush_rows; /* number of rows written since last flush */
283 #endif
284
285 #ifdef PNG_READ_GAMMA_SUPPORTED
286 int gamma_shift; /* number of "insignificant" bits in 16-bit gamma */
287 png_fixed_point screen_gamma; /* screen gamma value (display_exponent) */
288
289 png_bytep gamma_table; /* gamma table for 8-bit depth files */
290 png_uint_16pp gamma_16_table; /* gamma table for 16-bit depth files */
291 #if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
292 defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \
293 defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
294 png_bytep gamma_from_1; /* converts from 1.0 to screen */
295 png_bytep gamma_to_1; /* converts from file to 1.0 */
296 png_uint_16pp gamma_16_from_1; /* converts from 1.0 to screen */
297 png_uint_16pp gamma_16_to_1; /* converts from file to 1.0 */
298 #endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */
299 #endif
300
301 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_sBIT_SUPPORTED)
302 png_color_8 sig_bit; /* significant bits in each available channel */
303 #endif
304
305 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
306 png_color_8 shift; /* shift for significant bit tranformation */
307 #endif
308
309 #if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \
310 || defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
311 png_bytep trans_alpha; /* alpha values for paletted files */
312 png_color_16 trans_color; /* transparent color for non-paletted files */
313 #endif
314
315 png_read_status_ptr read_row_fn; /* called after each row is decoded */
316 png_write_status_ptr write_row_fn; /* called after each row is encoded */
317 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
318 png_progressive_info_ptr info_fn; /* called after header data fully read */
319 png_progressive_row_ptr row_fn; /* called after a prog. row is decoded */
320 png_progressive_end_ptr end_fn; /* called after image is complete */
321 png_bytep save_buffer_ptr; /* current location in save_buffer */
322 png_bytep save_buffer; /* buffer for previously read data */
323 png_bytep current_buffer_ptr; /* current location in current_buffer */
324 png_bytep current_buffer; /* buffer for recently used data */
325 png_uint_32 push_length; /* size of current input chunk */
326 png_uint_32 skip_length; /* bytes to skip in input data */
327 png_size_t save_buffer_size; /* amount of data now in save_buffer */
328 png_size_t save_buffer_max; /* total size of save_buffer */
329 png_size_t buffer_size; /* total amount of available input data */
330 png_size_t current_buffer_size; /* amount of data now in current_buffer */
331 int process_mode; /* what push library is currently doing */
332 int cur_palette; /* current push library palette index */
333
334 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
335
336 #if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
337 /* For the Borland special 64K segment handler */
338 png_bytepp offset_table_ptr;
339 png_bytep offset_table;
340 png_uint_16 offset_table_number;
341 png_uint_16 offset_table_count;
342 png_uint_16 offset_table_count_free;
343 #endif
344
345 #ifdef PNG_READ_QUANTIZE_SUPPORTED
346 png_bytep palette_lookup; /* lookup table for quantizing */
347 png_bytep quantize_index; /* index translation for palette files */
348 #endif
349
350 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
351 png_byte heuristic_method; /* heuristic for row filter selection */
352 png_byte num_prev_filters; /* number of weights for previous rows */
353 png_bytep prev_filters; /* filter type(s) of previous row(s) */
354 png_uint_16p filter_weights; /* weight(s) for previous line(s) */
355 png_uint_16p inv_filter_weights; /* 1/weight(s) for previous line(s) */
356 png_uint_16p filter_costs; /* relative filter calculation cost */
357 png_uint_16p inv_filter_costs; /* 1/relative filter calculation cost */
358 #endif
359
360 /* Options */
361 #ifdef PNG_SET_OPTION_SUPPORTED
362 png_byte options; /* On/off state (up to 4 options) */
363 #endif
364
365 #if PNG_LIBPNG_VER < 10700
366 /* To do: remove this from libpng-1.7 */
367 #ifdef PNG_TIME_RFC1123_SUPPORTED
368 char time_buffer[29]; /* String to hold RFC 1123 time text */
369 #endif
370 #endif
371
372 /* New members added in libpng-1.0.6 */
373
374 png_uint_32 free_me; /* flags items libpng is responsible for freeing */
375
376 #ifdef PNG_USER_CHUNKS_SUPPORTED
377 png_voidp user_chunk_ptr;
378 #ifdef PNG_READ_USER_CHUNKS_SUPPORTED
379 png_user_chunk_ptr read_user_chunk_fn; /* user read chunk handler */
380 #endif
381 #endif
382
383 #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
384 int unknown_default; /* As PNG_HANDLE_* */
385 unsigned int num_chunk_list; /* Number of entries in the list */
386 png_bytep chunk_list; /* List of png_byte[5]; the textual chunk name
387 * followed by a PNG_HANDLE_* byte */
388 #endif
389
390 /* New members added in libpng-1.0.3 */
391 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
392 png_byte rgb_to_gray_status;
393 /* Added in libpng 1.5.5 to record setting of coefficients: */
394 png_byte rgb_to_gray_coefficients_set;
395 /* These were changed from png_byte in libpng-1.0.6 */
396 png_uint_16 rgb_to_gray_red_coeff;
397 png_uint_16 rgb_to_gray_green_coeff;
398 /* deleted in 1.5.5: rgb_to_gray_blue_coeff; */
399 #endif
400
401 /* New member added in libpng-1.0.4 (renamed in 1.0.9) */
402 #if defined(PNG_MNG_FEATURES_SUPPORTED)
403 /* Changed from png_byte to png_uint_32 at version 1.2.0 */
404 png_uint_32 mng_features_permitted;
405 #endif
406
407 /* New member added in libpng-1.0.9, ifdef'ed out in 1.0.12, enabled in 1.2.0 */
408 #ifdef PNG_MNG_FEATURES_SUPPORTED
409 png_byte filter_type;
410 #endif
411
412 /* New members added in libpng-1.2.0 */
413
414 /* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */
415 #ifdef PNG_USER_MEM_SUPPORTED
416 png_voidp mem_ptr; /* user supplied struct for mem functions */
417 png_malloc_ptr malloc_fn; /* function for allocating memory */
418 png_free_ptr free_fn; /* function for freeing memory */
419 #endif
420
421 /* New member added in libpng-1.0.13 and 1.2.0 */
422 png_bytep big_row_buf; /* buffer to save current (unfiltered) row */
423
424 #ifdef PNG_READ_QUANTIZE_SUPPORTED
425 /* The following three members were added at version 1.0.14 and 1.2.4 */
426 png_bytep quantize_sort; /* working sort array */
427 png_bytep index_to_palette; /* where the original index currently is
428 in the palette */
429 png_bytep palette_to_index; /* which original index points to this
430 palette color */
431 #endif
432
433 /* New members added in libpng-1.0.16 and 1.2.6 */
434 png_byte compression_type;
435
436 #ifdef PNG_USER_LIMITS_SUPPORTED
437 png_uint_32 user_width_max;
438 png_uint_32 user_height_max;
439
440 /* Added in libpng-1.4.0: Total number of sPLT, text, and unknown
441 * chunks that can be stored (0 means unlimited).
442 */
443 png_uint_32 user_chunk_cache_max;
444
445 /* Total memory that a zTXt, sPLT, iTXt, iCCP, or unknown chunk
446 * can occupy when decompressed. 0 means unlimited.
447 */
448 png_alloc_size_t user_chunk_malloc_max;
449 #endif
450
451 /* New member added in libpng-1.0.25 and 1.2.17 */
452 #ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
453 /* Temporary storage for unknown chunk that the library doesn't recognize,
454 * used while reading the chunk.
455 */
456 png_unknown_chunk unknown_chunk;
457 #endif
458
459 /* New member added in libpng-1.2.26 */
460 png_size_t old_big_row_buf_size;
461
462 #ifdef PNG_READ_SUPPORTED
463 /* New member added in libpng-1.2.30 */
464 png_bytep read_buffer; /* buffer for reading chunk data */
465 png_alloc_size_t read_buffer_size; /* current size of the buffer */
466 #endif
467 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
468 uInt IDAT_read_size; /* limit on read buffer size for IDAT */
469 #endif
470
471 #ifdef PNG_IO_STATE_SUPPORTED
472 /* New member added in libpng-1.4.0 */
473 png_uint_32 io_state;
474 #endif
475
476 /* New member added in libpng-1.5.6 */
477 png_bytep big_prev_row;
478
479 /* New member added in libpng-1.5.7 */
480 void (*read_filter[PNG_FILTER_VALUE_LAST-1])(png_row_infop row_info,
481 png_bytep row, png_const_bytep prev_row);
482
483 #ifdef PNG_READ_SUPPORTED
484 #if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED)
485 png_colorspace colorspace;
486 #endif
487 #endif
488 };
489 #endif /* PNGSTRUCT_H */