1 /*
2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
3 *
4 * This code is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License version 2 only, as
6 * published by the Free Software Foundation. Oracle designates this
7 * particular file as subject to the "Classpath" exception as provided
8 * by Oracle in the LICENSE file that accompanied this code.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 */
24
25 /* pngstruct.h - header file for PNG reference library
26 *
27 * This file is available under and governed by the GNU General Public
28 * License version 2 only, as published by the Free Software Foundation.
29 * However, the following notice accompanied the original version of this
30 * file and, per its terms, should not be removed:
31 *
32 * Last changed in libpng 1.6.18 [July 23, 2015]
33 * Copyright (c) 1998-2002,2004,2006-2015 Glenn Randers-Pehrson
34 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
35 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
36 *
37 * This code is released under the libpng license.
38 * For conditions of distribution and use, see the disclaimer
39 * and license in png.h
40 */
41
42 /* The structure that holds the information to read and write PNG files.
43 * The only people who need to care about what is inside of this are the
44 * people who will be modifying the library for their own special needs.
45 * It should NOT be accessed directly by an application.
46 */
47
48 #ifndef PNGSTRUCT_H
49 #define PNGSTRUCT_H
50 /* zlib.h defines the structure z_stream, an instance of which is included
51 * in this structure and is required for decompressing the LZ compressed
52 * data in PNG files.
53 */
54 #ifndef ZLIB_CONST
55 /* We must ensure that zlib uses 'const' in declarations. */
56 # define ZLIB_CONST
57 #endif
58 #include "zlib.h"
59 #ifdef const
60 /* zlib.h sometimes #defines const to nothing, undo this. */
61 # undef const
62 #endif
63
64 /* zlib.h has mediocre z_const use before 1.2.6, this stuff is for compatibility
65 * with older builds.
66 */
67 #if ZLIB_VERNUM < 0x1260
68 # define PNGZ_MSG_CAST(s) png_constcast(char*,s)
69 # define PNGZ_INPUT_CAST(b) png_constcast(png_bytep,b)
70 #else
71 # define PNGZ_MSG_CAST(s) (s)
72 # define PNGZ_INPUT_CAST(b) (b)
73 #endif
74
75 /* zlib.h declares a magic type 'uInt' that limits the amount of data that zlib
76 * can handle at once. This type need be no larger than 16 bits (so maximum of
77 * 65535), this define allows us to discover how big it is, but limited by the
78 * maximuum for png_size_t. The value can be overriden in a library build
79 * (pngusr.h, or set it in CPPFLAGS) and it works to set it to a considerably
80 * lower value (e.g. 255 works). A lower value may help memory usage (slightly)
81 * and may even improve performance on some systems (and degrade it on others.)
82 */
83 #ifndef ZLIB_IO_MAX
84 # define ZLIB_IO_MAX ((uInt)-1)
85 #endif
86
87 #ifdef PNG_WRITE_SUPPORTED
88 /* The type of a compression buffer list used by the write code. */
89 typedef struct png_compression_buffer
90 {
91 struct png_compression_buffer *next;
92 png_byte output[1]; /* actually zbuf_size */
93 } png_compression_buffer, *png_compression_bufferp;
94
95 #define PNG_COMPRESSION_BUFFER_SIZE(pp)\
96 (offsetof(png_compression_buffer, output) + (pp)->zbuffer_size)
97 #endif
98
99 /* Colorspace support; structures used in png_struct, png_info and in internal
100 * functions to hold and communicate information about the color space.
101 *
102 * PNG_COLORSPACE_SUPPORTED is only required if the application will perform
103 * colorspace corrections, otherwise all the colorspace information can be
104 * skipped and the size of libpng can be reduced (significantly) by compiling
105 * out the colorspace support.
106 */
107 #ifdef PNG_COLORSPACE_SUPPORTED
108 /* The chromaticities of the red, green and blue colorants and the chromaticity
109 * of the corresponding white point (i.e. of rgb(1.0,1.0,1.0)).
110 */
111 typedef struct png_xy
112 {
113 png_fixed_point redx, redy;
114 png_fixed_point greenx, greeny;
115 png_fixed_point bluex, bluey;
116 png_fixed_point whitex, whitey;
117 } png_xy;
118
119 /* The same data as above but encoded as CIE XYZ values. When this data comes
120 * from chromaticities the sum of the Y values is assumed to be 1.0
121 */
122 typedef struct png_XYZ
123 {
124 png_fixed_point red_X, red_Y, red_Z;
125 png_fixed_point green_X, green_Y, green_Z;
126 png_fixed_point blue_X, blue_Y, blue_Z;
127 } png_XYZ;
128 #endif /* COLORSPACE */
129
130 #if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED)
131 /* A colorspace is all the above plus, potentially, profile information;
132 * however at present libpng does not use the profile internally so it is only
133 * stored in the png_info struct (if iCCP is supported.) The rendering intent
134 * is retained here and is checked.
135 *
136 * The file gamma encoding information is also stored here and gamma correction
137 * is done by libpng, whereas color correction must currently be done by the
138 * application.
139 */
140 typedef struct png_colorspace
141 {
142 #ifdef PNG_GAMMA_SUPPORTED
143 png_fixed_point gamma; /* File gamma */
144 #endif
145
146 #ifdef PNG_COLORSPACE_SUPPORTED
147 png_xy end_points_xy; /* End points as chromaticities */
148 png_XYZ end_points_XYZ; /* End points as CIE XYZ colorant values */
149 png_uint_16 rendering_intent; /* Rendering intent of a profile */
150 #endif
151
152 /* Flags are always defined to simplify the code. */
153 png_uint_16 flags; /* As defined below */
154 } png_colorspace, * PNG_RESTRICT png_colorspacerp;
155
156 typedef const png_colorspace * PNG_RESTRICT png_const_colorspacerp;
157
158 /* General flags for the 'flags' field */
159 #define PNG_COLORSPACE_HAVE_GAMMA 0x0001
160 #define PNG_COLORSPACE_HAVE_ENDPOINTS 0x0002
161 #define PNG_COLORSPACE_HAVE_INTENT 0x0004
162 #define PNG_COLORSPACE_FROM_gAMA 0x0008
163 #define PNG_COLORSPACE_FROM_cHRM 0x0010
164 #define PNG_COLORSPACE_FROM_sRGB 0x0020
165 #define PNG_COLORSPACE_ENDPOINTS_MATCH_sRGB 0x0040
166 #define PNG_COLORSPACE_MATCHES_sRGB 0x0080 /* exact match on profile */
167 #define PNG_COLORSPACE_INVALID 0x8000
168 #define PNG_COLORSPACE_CANCEL(flags) (0xffff ^ (flags))
169 #endif /* COLORSPACE || GAMMA */
170
171 struct png_struct_def
172 {
173 #ifdef PNG_SETJMP_SUPPORTED
174 jmp_buf jmp_buf_local; /* New name in 1.6.0 for jmp_buf in png_struct */
175 png_longjmp_ptr longjmp_fn;/* setjmp non-local goto function. */
176 jmp_buf *jmp_buf_ptr; /* passed to longjmp_fn */
177 size_t jmp_buf_size; /* size of the above, if allocated */
178 #endif
179 png_error_ptr error_fn; /* function for printing errors and aborting */
180 #ifdef PNG_WARNINGS_SUPPORTED
181 png_error_ptr warning_fn; /* function for printing warnings */
182 #endif
183 png_voidp error_ptr; /* user supplied struct for error functions */
184 png_rw_ptr write_data_fn; /* function for writing output data */
185 png_rw_ptr read_data_fn; /* function for reading input data */
186 png_voidp io_ptr; /* ptr to application struct for I/O functions */
187
188 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
189 png_user_transform_ptr read_user_transform_fn; /* user read transform */
190 #endif
191
192 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
193 png_user_transform_ptr write_user_transform_fn; /* user write transform */
194 #endif
195
196 /* These were added in libpng-1.0.2 */
197 #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
198 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
199 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
200 png_voidp user_transform_ptr; /* user supplied struct for user transform */
201 png_byte user_transform_depth; /* bit depth of user transformed pixels */
202 png_byte user_transform_channels; /* channels in user transformed pixels */
203 #endif
204 #endif
205
206 png_uint_32 mode; /* tells us where we are in the PNG file */
207 png_uint_32 flags; /* flags indicating various things to libpng */
208 png_uint_32 transformations; /* which transformations to perform */
209
210 png_uint_32 zowner; /* ID (chunk type) of zstream owner, 0 if none */
211 z_stream zstream; /* decompression structure */
212
213 #ifdef PNG_WRITE_SUPPORTED
214 png_compression_bufferp zbuffer_list; /* Created on demand during write */
215 uInt zbuffer_size; /* size of the actual buffer */
216
217 int zlib_level; /* holds zlib compression level */
218 int zlib_method; /* holds zlib compression method */
219 int zlib_window_bits; /* holds zlib compression window bits */
220 int zlib_mem_level; /* holds zlib compression memory level */
221 int zlib_strategy; /* holds zlib compression strategy */
222 #endif
223 /* Added at libpng 1.5.4 */
224 #ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
225 int zlib_text_level; /* holds zlib compression level */
226 int zlib_text_method; /* holds zlib compression method */
227 int zlib_text_window_bits; /* holds zlib compression window bits */
228 int zlib_text_mem_level; /* holds zlib compression memory level */
229 int zlib_text_strategy; /* holds zlib compression strategy */
230 #endif
231 /* End of material added at libpng 1.5.4 */
232 /* Added at libpng 1.6.0 */
233 #ifdef PNG_WRITE_SUPPORTED
234 int zlib_set_level; /* Actual values set into the zstream on write */
235 int zlib_set_method;
236 int zlib_set_window_bits;
237 int zlib_set_mem_level;
238 int zlib_set_strategy;
239 #endif
240
241 png_uint_32 width; /* width of image in pixels */
242 png_uint_32 height; /* height of image in pixels */
243 png_uint_32 num_rows; /* number of rows in current pass */
244 png_uint_32 usr_width; /* width of row at start of write */
245 png_size_t rowbytes; /* size of row in bytes */
246 png_uint_32 iwidth; /* width of current interlaced row in pixels */
247 png_uint_32 row_number; /* current row in interlace pass */
248 png_uint_32 chunk_name; /* PNG_CHUNK() id of current chunk */
249 png_bytep prev_row; /* buffer to save previous (unfiltered) row.
250 * While reading this is a pointer into
251 * big_prev_row; while writing it is separately
252 * allocated if needed.
253 */
254 png_bytep row_buf; /* buffer to save current (unfiltered) row.
255 * While reading, this is a pointer into
256 * big_row_buf; while writing it is separately
257 * allocated.
258 */
259 #ifdef PNG_WRITE_FILTER_SUPPORTED
260 png_bytep try_row; /* buffer to save trial row when filtering */
261 png_bytep tst_row; /* buffer to save best trial row when filtering */
262 #endif
263 png_size_t info_rowbytes; /* Added in 1.5.4: cache of updated row bytes */
264
265 png_uint_32 idat_size; /* current IDAT size for read */
266 png_uint_32 crc; /* current chunk CRC value */
267 png_colorp palette; /* palette from the input file */
268 png_uint_16 num_palette; /* number of color entries in palette */
269
270 /* Added at libpng-1.5.10 */
271 #ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
272 int num_palette_max; /* maximum palette index found in IDAT */
273 #endif
274
275 png_uint_16 num_trans; /* number of transparency values */
276 png_byte compression; /* file compression type (always 0) */
277 png_byte filter; /* file filter type (always 0) */
278 png_byte interlaced; /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
279 png_byte pass; /* current interlace pass (0 - 6) */
280 png_byte do_filter; /* row filter flags (see PNG_FILTER_ below ) */
281 png_byte color_type; /* color type of file */
282 png_byte bit_depth; /* bit depth of file */
283 png_byte usr_bit_depth; /* bit depth of users row: write only */
284 png_byte pixel_depth; /* number of bits per pixel */
285 png_byte channels; /* number of channels in file */
286 #ifdef PNG_WRITE_SUPPORTED
287 png_byte usr_channels; /* channels at start of write: write only */
288 #endif
289 png_byte sig_bytes; /* magic bytes read/written from start of file */
290 png_byte maximum_pixel_depth;
291 /* pixel depth used for the row buffers */
292 png_byte transformed_pixel_depth;
293 /* pixel depth after read/write transforms */
294 #if PNG_ZLIB_VERNUM >= 0x1240
295 png_byte zstream_start; /* at start of an input zlib stream */
296 #endif /* Zlib >= 1.2.4 */
297 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
298 png_uint_16 filler; /* filler bytes for pixel expansion */
299 #endif
300
301 #if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
302 defined(PNG_READ_ALPHA_MODE_SUPPORTED)
303 png_byte background_gamma_type;
304 png_fixed_point background_gamma;
305 png_color_16 background; /* background color in screen gamma space */
306 #ifdef PNG_READ_GAMMA_SUPPORTED
307 png_color_16 background_1; /* background normalized to gamma 1.0 */
308 #endif
309 #endif /* bKGD */
310
311 #ifdef PNG_WRITE_FLUSH_SUPPORTED
312 png_flush_ptr output_flush_fn; /* Function for flushing output */
313 png_uint_32 flush_dist; /* how many rows apart to flush, 0 - no flush */
314 png_uint_32 flush_rows; /* number of rows written since last flush */
315 #endif
316
317 #ifdef PNG_READ_GAMMA_SUPPORTED
318 int gamma_shift; /* number of "insignificant" bits in 16-bit gamma */
319 png_fixed_point screen_gamma; /* screen gamma value (display_exponent) */
320
321 png_bytep gamma_table; /* gamma table for 8-bit depth files */
322 png_uint_16pp gamma_16_table; /* gamma table for 16-bit depth files */
323 #if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
324 defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \
325 defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
326 png_bytep gamma_from_1; /* converts from 1.0 to screen */
327 png_bytep gamma_to_1; /* converts from file to 1.0 */
328 png_uint_16pp gamma_16_from_1; /* converts from 1.0 to screen */
329 png_uint_16pp gamma_16_to_1; /* converts from file to 1.0 */
330 #endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */
331 #endif
332
333 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_sBIT_SUPPORTED)
334 png_color_8 sig_bit; /* significant bits in each available channel */
335 #endif
336
337 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
338 png_color_8 shift; /* shift for significant bit tranformation */
339 #endif
340
341 #if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \
342 || defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
343 png_bytep trans_alpha; /* alpha values for paletted files */
344 png_color_16 trans_color; /* transparent color for non-paletted files */
345 #endif
346
347 png_read_status_ptr read_row_fn; /* called after each row is decoded */
348 png_write_status_ptr write_row_fn; /* called after each row is encoded */
349 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
350 png_progressive_info_ptr info_fn; /* called after header data fully read */
351 png_progressive_row_ptr row_fn; /* called after a prog. row is decoded */
352 png_progressive_end_ptr end_fn; /* called after image is complete */
353 png_bytep save_buffer_ptr; /* current location in save_buffer */
354 png_bytep save_buffer; /* buffer for previously read data */
355 png_bytep current_buffer_ptr; /* current location in current_buffer */
356 png_bytep current_buffer; /* buffer for recently used data */
357 png_uint_32 push_length; /* size of current input chunk */
358 png_uint_32 skip_length; /* bytes to skip in input data */
359 png_size_t save_buffer_size; /* amount of data now in save_buffer */
360 png_size_t save_buffer_max; /* total size of save_buffer */
361 png_size_t buffer_size; /* total amount of available input data */
362 png_size_t current_buffer_size; /* amount of data now in current_buffer */
363 int process_mode; /* what push library is currently doing */
364 int cur_palette; /* current push library palette index */
365
366 #endif /* PROGRESSIVE_READ */
367
368 #if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
369 /* For the Borland special 64K segment handler */
370 png_bytepp offset_table_ptr;
371 png_bytep offset_table;
372 png_uint_16 offset_table_number;
373 png_uint_16 offset_table_count;
374 png_uint_16 offset_table_count_free;
375 #endif
376
377 #ifdef PNG_READ_QUANTIZE_SUPPORTED
378 png_bytep palette_lookup; /* lookup table for quantizing */
379 png_bytep quantize_index; /* index translation for palette files */
380 #endif
381
382 /* Options */
383 #ifdef PNG_SET_OPTION_SUPPORTED
384 png_byte options; /* On/off state (up to 4 options) */
385 #endif
386
387 #if PNG_LIBPNG_VER < 10700
388 /* To do: remove this from libpng-1.7 */
389 #ifdef PNG_TIME_RFC1123_SUPPORTED
390 char time_buffer[29]; /* String to hold RFC 1123 time text */
391 #endif
392 #endif
393
394 /* New members added in libpng-1.0.6 */
395
396 png_uint_32 free_me; /* flags items libpng is responsible for freeing */
397
398 #ifdef PNG_USER_CHUNKS_SUPPORTED
399 png_voidp user_chunk_ptr;
400 #ifdef PNG_READ_USER_CHUNKS_SUPPORTED
401 png_user_chunk_ptr read_user_chunk_fn; /* user read chunk handler */
402 #endif
403 #endif
404
405 #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
406 int unknown_default; /* As PNG_HANDLE_* */
407 unsigned int num_chunk_list; /* Number of entries in the list */
408 png_bytep chunk_list; /* List of png_byte[5]; the textual chunk name
409 * followed by a PNG_HANDLE_* byte */
410 #endif
411
412 /* New members added in libpng-1.0.3 */
413 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
414 png_byte rgb_to_gray_status;
415 /* Added in libpng 1.5.5 to record setting of coefficients: */
416 png_byte rgb_to_gray_coefficients_set;
417 /* These were changed from png_byte in libpng-1.0.6 */
418 png_uint_16 rgb_to_gray_red_coeff;
419 png_uint_16 rgb_to_gray_green_coeff;
420 /* deleted in 1.5.5: rgb_to_gray_blue_coeff; */
421 #endif
422
423 /* New member added in libpng-1.0.4 (renamed in 1.0.9) */
424 #if defined(PNG_MNG_FEATURES_SUPPORTED)
425 /* Changed from png_byte to png_uint_32 at version 1.2.0 */
426 png_uint_32 mng_features_permitted;
427 #endif
428
429 /* New member added in libpng-1.0.9, ifdef'ed out in 1.0.12, enabled in 1.2.0 */
430 #ifdef PNG_MNG_FEATURES_SUPPORTED
431 png_byte filter_type;
432 #endif
433
434 /* New members added in libpng-1.2.0 */
435
436 /* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */
437 #ifdef PNG_USER_MEM_SUPPORTED
438 png_voidp mem_ptr; /* user supplied struct for mem functions */
439 png_malloc_ptr malloc_fn; /* function for allocating memory */
440 png_free_ptr free_fn; /* function for freeing memory */
441 #endif
442
443 /* New member added in libpng-1.0.13 and 1.2.0 */
444 png_bytep big_row_buf; /* buffer to save current (unfiltered) row */
445
446 #ifdef PNG_READ_QUANTIZE_SUPPORTED
447 /* The following three members were added at version 1.0.14 and 1.2.4 */
448 png_bytep quantize_sort; /* working sort array */
449 png_bytep index_to_palette; /* where the original index currently is
450 in the palette */
451 png_bytep palette_to_index; /* which original index points to this
452 palette color */
453 #endif
454
455 /* New members added in libpng-1.0.16 and 1.2.6 */
456 png_byte compression_type;
457
458 #ifdef PNG_USER_LIMITS_SUPPORTED
459 png_uint_32 user_width_max;
460 png_uint_32 user_height_max;
461
462 /* Added in libpng-1.4.0: Total number of sPLT, text, and unknown
463 * chunks that can be stored (0 means unlimited).
464 */
465 png_uint_32 user_chunk_cache_max;
466
467 /* Total memory that a zTXt, sPLT, iTXt, iCCP, or unknown chunk
468 * can occupy when decompressed. 0 means unlimited.
469 */
470 png_alloc_size_t user_chunk_malloc_max;
471 #endif
472
473 /* New member added in libpng-1.0.25 and 1.2.17 */
474 #ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
475 /* Temporary storage for unknown chunk that the library doesn't recognize,
476 * used while reading the chunk.
477 */
478 png_unknown_chunk unknown_chunk;
479 #endif
480
481 /* New member added in libpng-1.2.26 */
482 png_size_t old_big_row_buf_size;
483
484 #ifdef PNG_READ_SUPPORTED
485 /* New member added in libpng-1.2.30 */
486 png_bytep read_buffer; /* buffer for reading chunk data */
487 png_alloc_size_t read_buffer_size; /* current size of the buffer */
488 #endif
489 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
490 uInt IDAT_read_size; /* limit on read buffer size for IDAT */
491 #endif
492
493 #ifdef PNG_IO_STATE_SUPPORTED
494 /* New member added in libpng-1.4.0 */
495 png_uint_32 io_state;
496 #endif
497
498 /* New member added in libpng-1.5.6 */
499 png_bytep big_prev_row;
500
501 /* New member added in libpng-1.5.7 */
502 void (*read_filter[PNG_FILTER_VALUE_LAST-1])(png_row_infop row_info,
503 png_bytep row, png_const_bytep prev_row);
504
505 #ifdef PNG_READ_SUPPORTED
506 #if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED)
507 png_colorspace colorspace;
508 #endif
509 #endif
510 };
511 #endif /* PNGSTRUCT_H */