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 1.6.28 [January 5, 2017]
33 * Copyright (c) 1998-2002,2004,2006-2017 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. */
89typedef 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 */
111typedef 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 */
122typedef 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 */
140typedef 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
156typedef 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
171struct 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_ in png.h ) */
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 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_uint_32 options;           /* On/off state (up to 16 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 */
512