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/* pnginfo.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 1.6.1 [March 28, 2013] 33 * Copyright (c) 1998-2002,2004,2006-2013 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 /* png_info is a structure that holds the information in a PNG file so 43 * that the application can find out the characteristics of the image. 44 * If you are reading the file, this structure will tell you what is 45 * in the PNG file. If you are writing the file, fill in the information 46 * you want to put into the PNG file, using png_set_*() functions, then 47 * call png_write_info(). 48 * 49 * The names chosen should be very close to the PNG specification, so 50 * consult that document for information about the meaning of each field. 51 * 52 * With libpng < 0.95, it was only possible to directly set and read the 53 * the values in the png_info_struct, which meant that the contents and 54 * order of the values had to remain fixed. With libpng 0.95 and later, 55 * however, there are now functions that abstract the contents of 56 * png_info_struct from the application, so this makes it easier to use 57 * libpng with dynamic libraries, and even makes it possible to use 58 * libraries that don't have all of the libpng ancillary chunk-handing 59 * functionality. In libpng-1.5.0 this was moved into a separate private 60 * file that is not visible to applications. 61 * 62 * The following members may have allocated storage attached that should be 63 * cleaned up before the structure is discarded: palette, trans, text, 64 * pcal_purpose, pcal_units, pcal_params, hist, iccp_name, iccp_profile, 65 * splt_palettes, scal_unit, row_pointers, and unknowns. By default, these 66 * are automatically freed when the info structure is deallocated, if they were 67 * allocated internally by libpng. This behavior can be changed by means 68 * of the png_data_freer() function. 69 * 70 * More allocation details: all the chunk-reading functions that 71 * change these members go through the corresponding png_set_* 72 * functions. A function to clear these members is available: see 73 * png_free_data(). The png_set_* functions do not depend on being 74 * able to point info structure members to any of the storage they are 75 * passed (they make their own copies), EXCEPT that the png_set_text 76 * functions use the same storage passed to them in the text_ptr or 77 * itxt_ptr structure argument, and the png_set_rows and png_set_unknowns 78 * functions do not make their own copies. 79 */ 80#ifndef PNGINFO_H 81#define PNGINFO_H 82 83struct png_info_def 84{ 85 /* The following are necessary for every PNG file */ 86 png_uint_32 width; /* width of image in pixels (from IHDR) */ 87 png_uint_32 height; /* height of image in pixels (from IHDR) */ 88 png_uint_32 valid; /* valid chunk data (see PNG_INFO_ below) */ 89 png_size_t rowbytes; /* bytes needed to hold an untransformed row */ 90 png_colorp palette; /* array of color values (valid & PNG_INFO_PLTE) */ 91 png_uint_16 num_palette; /* number of color entries in "palette" (PLTE) */ 92 png_uint_16 num_trans; /* number of transparent palette color (tRNS) */ 93 png_byte bit_depth; /* 1, 2, 4, 8, or 16 bits/channel (from IHDR) */ 94 png_byte color_type; /* see PNG_COLOR_TYPE_ below (from IHDR) */ 95 /* The following three should have been named *_method not *_type */ 96 png_byte compression_type; /* must be PNG_COMPRESSION_TYPE_BASE (IHDR) */ 97 png_byte filter_type; /* must be PNG_FILTER_TYPE_BASE (from IHDR) */ 98 png_byte interlace_type; /* One of PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */ 99 100 /* The following are set by png_set_IHDR, called from the application on 101 * write, but the are never actually used by the write code. 102 */ 103 png_byte channels; /* number of data channels per pixel (1, 2, 3, 4) */ 104 png_byte pixel_depth; /* number of bits per pixel */ 105 png_byte spare_byte; /* to align the data, and for future use */ 106 107#ifdef PNG_READ_SUPPORTED 108 /* This is never set during write */ 109 png_byte signature[8]; /* magic bytes read by libpng from start of file */ 110#endif 111 112 /* The rest of the data is optional. If you are reading, check the 113 * valid field to see if the information in these are valid. If you 114 * are writing, set the valid field to those chunks you want written, 115 * and initialize the appropriate fields below. 116 */ 117 118#if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED) 119 /* png_colorspace only contains 'flags' if neither GAMMA or COLORSPACE are 120 * defined. When COLORSPACE is switched on all the colorspace-defining 121 * chunks should be enabled, when GAMMA is switched on all the gamma-defining 122 * chunks should be enabled. If this is not done it becomes possible to read 123 * inconsistent PNG files and assign a probably incorrect interpretation to 124 * the information. (In other words, by carefully choosing which chunks to 125 * recognize the system configuration can select an interpretation for PNG 126 * files containing ambiguous data and this will result in inconsistent 127 * behavior between different libpng builds!) 128 */ 129 png_colorspace colorspace; 130#endif 131 132#ifdef PNG_iCCP_SUPPORTED 133 /* iCCP chunk data. */ 134 png_charp iccp_name; /* profile name */ 135 png_bytep iccp_profile; /* International Color Consortium profile data */ 136 png_uint_32 iccp_proflen; /* ICC profile data length */ 137#endif 138 139#ifdef PNG_TEXT_SUPPORTED 140 /* The tEXt, and zTXt chunks contain human-readable textual data in 141 * uncompressed, compressed, and optionally compressed forms, respectively. 142 * The data in "text" is an array of pointers to uncompressed, 143 * null-terminated C strings. Each chunk has a keyword that describes the 144 * textual data contained in that chunk. Keywords are not required to be 145 * unique, and the text string may be empty. Any number of text chunks may 146 * be in an image. 147 */ 148 int num_text; /* number of comments read or comments to write */ 149 int max_text; /* current size of text array */ 150 png_textp text; /* array of comments read or comments to write */ 151#endif /* TEXT */ 152 153#ifdef PNG_tIME_SUPPORTED 154 /* The tIME chunk holds the last time the displayed image data was 155 * modified. See the png_time struct for the contents of this struct. 156 */ 157 png_time mod_time; 158#endif 159 160#ifdef PNG_sBIT_SUPPORTED 161 /* The sBIT chunk specifies the number of significant high-order bits 162 * in the pixel data. Values are in the range [1, bit_depth], and are 163 * only specified for the channels in the pixel data. The contents of 164 * the low-order bits is not specified. Data is valid if 165 * (valid & PNG_INFO_sBIT) is non-zero. 166 */ 167 png_color_8 sig_bit; /* significant bits in color channels */ 168#endif 169 170#if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_EXPAND_SUPPORTED) || \ 171defined(PNG_READ_BACKGROUND_SUPPORTED) 172 /* The tRNS chunk supplies transparency data for paletted images and 173 * other image types that don't need a full alpha channel. There are 174 * "num_trans" transparency values for a paletted image, stored in the 175 * same order as the palette colors, starting from index 0. Values 176 * for the data are in the range [0, 255], ranging from fully transparent 177 * to fully opaque, respectively. For non-paletted images, there is a 178 * single color specified that should be treated as fully transparent. 179 * Data is valid if (valid & PNG_INFO_tRNS) is non-zero. 180 */ 181 png_bytep trans_alpha; /* alpha values for paletted image */ 182 png_color_16 trans_color; /* transparent color for non-palette image */ 183#endif 184 185#if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) 186 /* The bKGD chunk gives the suggested image background color if the 187 * display program does not have its own background color and the image 188 * is needs to composited onto a background before display. The colors 189 * in "background" are normally in the same color space/depth as the 190 * pixel data. Data is valid if (valid & PNG_INFO_bKGD) is non-zero. 191 */ 192 png_color_16 background; 193#endif 194 195#ifdef PNG_oFFs_SUPPORTED 196 /* The oFFs chunk gives the offset in "offset_unit_type" units rightwards 197 * and downwards from the top-left corner of the display, page, or other 198 * application-specific co-ordinate space. See the PNG_OFFSET_ defines 199 * below for the unit types. Valid if (valid & PNG_INFO_oFFs) non-zero. 200 */ 201 png_int_32 x_offset; /* x offset on page */ 202 png_int_32 y_offset; /* y offset on page */ 203 png_byte offset_unit_type; /* offset units type */ 204#endif 205 206#ifdef PNG_pHYs_SUPPORTED 207 /* The pHYs chunk gives the physical pixel density of the image for 208 * display or printing in "phys_unit_type" units (see PNG_RESOLUTION_ 209 * defines below). Data is valid if (valid & PNG_INFO_pHYs) is non-zero. 210 */ 211 png_uint_32 x_pixels_per_unit; /* horizontal pixel density */ 212 png_uint_32 y_pixels_per_unit; /* vertical pixel density */ 213 png_byte phys_unit_type; /* resolution type (see PNG_RESOLUTION_ below) */ 214#endif 215 216#ifdef PNG_hIST_SUPPORTED 217 /* The hIST chunk contains the relative frequency or importance of the 218 * various palette entries, so that a viewer can intelligently select a 219 * reduced-color palette, if required. Data is an array of "num_palette" 220 * values in the range [0,65535]. Data valid if (valid & PNG_INFO_hIST) 221 * is non-zero. 222 */ 223 png_uint_16p hist; 224#endif 225 226#ifdef PNG_pCAL_SUPPORTED 227 /* The pCAL chunk describes a transformation between the stored pixel 228 * values and original physical data values used to create the image. 229 * The integer range [0, 2^bit_depth - 1] maps to the floating-point 230 * range given by [pcal_X0, pcal_X1], and are further transformed by a 231 * (possibly non-linear) transformation function given by "pcal_type" 232 * and "pcal_params" into "pcal_units". Please see the PNG_EQUATION_ 233 * defines below, and the PNG-Group's PNG extensions document for a 234 * complete description of the transformations and how they should be 235 * implemented, and for a description of the ASCII parameter strings. 236 * Data values are valid if (valid & PNG_INFO_pCAL) non-zero. 237 */ 238 png_charp pcal_purpose; /* pCAL chunk description string */ 239 png_int_32 pcal_X0; /* minimum value */ 240 png_int_32 pcal_X1; /* maximum value */ 241 png_charp pcal_units; /* Latin-1 string giving physical units */ 242 png_charpp pcal_params; /* ASCII strings containing parameter values */ 243 png_byte pcal_type; /* equation type (see PNG_EQUATION_ below) */ 244 png_byte pcal_nparams; /* number of parameters given in pcal_params */ 245#endif 246 247/* New members added in libpng-1.0.6 */ 248 png_uint_32 free_me; /* flags items libpng is responsible for freeing */ 249 250#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED 251 /* Storage for unknown chunks that the library doesn't recognize. */ 252 png_unknown_chunkp unknown_chunks; 253 254 /* The type of this field is limited by the type of 255 * png_struct::user_chunk_cache_max, else overflow can occur. 256 */ 257 int unknown_chunks_num; 258#endif 259 260#ifdef PNG_sPLT_SUPPORTED 261 /* Data on sPLT chunks (there may be more than one). */ 262 png_sPLT_tp splt_palettes; 263 int splt_palettes_num; /* Match type returned by png_get API */ 264#endif 265 266#ifdef PNG_sCAL_SUPPORTED 267 /* The sCAL chunk describes the actual physical dimensions of the 268 * subject matter of the graphic. The chunk contains a unit specification 269 * a byte value, and two ASCII strings representing floating-point 270 * values. The values are width and height corresponsing to one pixel 271 * in the image. Data values are valid if (valid & PNG_INFO_sCAL) is 272 * non-zero. 273 */ 274 png_byte scal_unit; /* unit of physical scale */ 275 png_charp scal_s_width; /* string containing height */ 276 png_charp scal_s_height; /* string containing width */ 277#endif 278 279#ifdef PNG_INFO_IMAGE_SUPPORTED 280 /* Memory has been allocated if (valid & PNG_ALLOCATED_INFO_ROWS) 281 non-zero */ 282 /* Data valid if (valid & PNG_INFO_IDAT) non-zero */ 283 png_bytepp row_pointers; /* the image bits */ 284#endif 285 286}; 287#endif /* PNGINFO_H */ 288