rev 55557 : 8217676: Upgrade libpng to 1.6.37
Reviewed-by: prr, jdv

   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 1.6.35 [July 15, 2018]
  33  * Copyright (c) 1998-2002,2004,2006-2013,2018 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 
  83 struct 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    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) || \
 171 defined(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_eXIf_SUPPORTED
 217    int num_exif;  /* Added at libpng-1.6.31 */
 218    png_bytep exif;
 219 # ifdef PNG_READ_eXIf_SUPPORTED
 220    png_bytep eXIf_buf;  /* Added at libpng-1.6.32 */
 221 # endif
 222 #endif
 223 
 224 #ifdef PNG_hIST_SUPPORTED
 225    /* The hIST chunk contains the relative frequency or importance of the
 226     * various palette entries, so that a viewer can intelligently select a
 227     * reduced-color palette, if required.  Data is an array of "num_palette"
 228     * values in the range [0,65535]. Data valid if (valid & PNG_INFO_hIST)
 229     * is non-zero.
 230     */
 231    png_uint_16p hist;
 232 #endif
 233 
 234 #ifdef PNG_pCAL_SUPPORTED
 235    /* The pCAL chunk describes a transformation between the stored pixel
 236     * values and original physical data values used to create the image.
 237     * The integer range [0, 2^bit_depth - 1] maps to the floating-point
 238     * range given by [pcal_X0, pcal_X1], and are further transformed by a
 239     * (possibly non-linear) transformation function given by "pcal_type"
 240     * and "pcal_params" into "pcal_units".  Please see the PNG_EQUATION_
 241     * defines below, and the PNG-Group's PNG extensions document for a
 242     * complete description of the transformations and how they should be
 243     * implemented, and for a description of the ASCII parameter strings.
 244     * Data values are valid if (valid & PNG_INFO_pCAL) non-zero.
 245     */
 246    png_charp pcal_purpose;  /* pCAL chunk description string */
 247    png_int_32 pcal_X0;      /* minimum value */
 248    png_int_32 pcal_X1;      /* maximum value */
 249    png_charp pcal_units;    /* Latin-1 string giving physical units */
 250    png_charpp pcal_params;  /* ASCII strings containing parameter values */
 251    png_byte pcal_type;      /* equation type (see PNG_EQUATION_ below) */
 252    png_byte pcal_nparams;   /* number of parameters given in pcal_params */
 253 #endif
 254 
 255 /* New members added in libpng-1.0.6 */
 256    png_uint_32 free_me;     /* flags items libpng is responsible for freeing */
 257 
 258 #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
 259    /* Storage for unknown chunks that the library doesn't recognize. */
 260    png_unknown_chunkp unknown_chunks;
 261 
 262    /* The type of this field is limited by the type of
 263     * png_struct::user_chunk_cache_max, else overflow can occur.
 264     */
 265    int                unknown_chunks_num;
 266 #endif
 267 
 268 #ifdef PNG_sPLT_SUPPORTED
 269    /* Data on sPLT chunks (there may be more than one). */
 270    png_sPLT_tp splt_palettes;
 271    int         splt_palettes_num; /* Match type returned by png_get API */
 272 #endif
 273 
 274 #ifdef PNG_sCAL_SUPPORTED
 275    /* The sCAL chunk describes the actual physical dimensions of the
 276     * subject matter of the graphic.  The chunk contains a unit specification
 277     * a byte value, and two ASCII strings representing floating-point
 278     * values.  The values are width and height corresponding to one pixel
 279     * in the image.  Data values are valid if (valid & PNG_INFO_sCAL) is
 280     * non-zero.
 281     */
 282    png_byte scal_unit;         /* unit of physical scale */
 283    png_charp scal_s_width;     /* string containing height */
 284    png_charp scal_s_height;    /* string containing width */
 285 #endif
 286 
 287 #ifdef PNG_INFO_IMAGE_SUPPORTED
 288    /* Memory has been allocated if (valid & PNG_ALLOCATED_INFO_ROWS)
 289       non-zero */
 290    /* Data valid if (valid & PNG_INFO_IDAT) non-zero */
 291    png_bytepp row_pointers;        /* the image bits */
 292 #endif
 293 
 294 };
 295 #endif /* PNGINFO_H */
--- EOF ---