libraries/freetype-2.0.5/include/freetype/cache/ftcsbits.h

   1 /***************************************************************************/
   2 /*                                                                         */
   3 /*  ftcsbits.h                                                             */
   4 /*                                                                         */
   5 /*    A small-bitmap cache (specification).                                */
   6 /*                                                                         */
   7 /*  Copyright 2000-2001 by                                                 */
   8 /*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
   9 /*                                                                         */
  10 /*  This file is part of the FreeType project, and may only be used,       */
  11 /*  modified, and distributed under the terms of the FreeType project      */
  12 /*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
  13 /*  this file you indicate that you have read the license and              */
  14 /*  understand and accept it fully.                                        */
  15 /*                                                                         */
  16 /***************************************************************************/
  17
  18
  19 #ifndef __FTCSBITS_H__
  20 #define __FTCSBITS_H__
  21
  22
  23 #include <ft2build.h>
  24 #include FT_CACHE_H
  25 #include FT_CACHE_INTERNAL_CHUNK_H
  26 #include FT_CACHE_IMAGE_H
  27
  28
  29 FT_BEGIN_HEADER
  30
  31
  32   /*************************************************************************/
  33   /*                                                                       */
  34   /* <Section>                                                             */
  35   /*    cache_subsystem                                                    */
  36   /*                                                                       */
  37   /*************************************************************************/
  38
  39
  40   /*************************************************************************/
  41   /*                                                                       */
  42   /* <Type>                                                                */
  43   /*    FTC_SBit                                                           */
  44   /*                                                                       */
  45   /* <Description>                                                         */
  46   /*    A handle to a small bitmap descriptor.  See the FTC_SBitRec        */
  47   /*    structure for details.                                             */
  48   /*                                                                       */
  49   typedef struct FTC_SBitRec_*  FTC_SBit;
  50
  51
  52   /*************************************************************************/
  53   /*                                                                       */
  54   /* <Type>                                                                */
  55   /*    FTC_SBit_Cache                                                     */
  56   /*                                                                       */
  57   /* <Description>                                                         */
  58   /*    A handle to a small bitmap cache.  These are special cache objects */
  59   /*    used to store small glyph bitmaps (and anti-aliased pixmaps) in a  */
  60   /*    much more efficient way than the traditional glyph image cache     */
  61   /*    implemented by FTC_Image_Cache.                                    */
  62   /*                                                                       */
  63   typedef struct FTC_SBit_CacheRec_*  FTC_SBit_Cache;
  64
  65
  66   /*************************************************************************/
  67   /*                                                                       */
  68   /* <Struct>                                                              */
  69   /*    FTC_SBitRec                                                        */
  70   /*                                                                       */
  71   /* <Description>                                                         */
  72   /*    A very compact structure used to describe a small glyph bitmap.    */
  73   /*                                                                       */
  74   /* <Fields>                                                              */
  75   /*    width    :: The bitmap width in pixels.                            */
  76   /*                                                                       */
  77   /*    height   :: The bitmap height in pixels.                           */
  78   /*                                                                       */
  79   /*    left     :: The horizontal distance from the pen position to the   */
  80   /*                left bitmap border (a.k.a. `left side bearing', or     */
  81   /*                `lsb').                                                */
  82   /*                                                                       */
  83   /*    top      :: The vertical distance from the pen position (on the    */
  84   /*                baseline) to the upper bitmap border (a.k.a. `top side */
  85   /*                bearing').  The distance is positive for upwards       */
  86   /*                Y coordinates.                                         */
  87   /*                                                                       */
  88   /*    format   :: The format of the glyph bitmap (monochrome or gray).   */
  89   /*                                                                       */
  90   /*    pitch    :: The number of bytes per bitmap line.  May be positive  */
  91   /*                or negative.                                           */
  92   /*                                                                       */
  93   /*    xadvance :: The horizontal advance width in pixels.                */
  94   /*                                                                       */
  95   /*    yadvance :: The vertical advance height in pixels.                 */
  96   /*                                                                       */
  97   /*    buffer   :: A pointer to the bitmap pixels.                        */
  98   /*                                                                       */
  99   typedef struct  FTC_SBitRec_
 100   {
 101     FT_Byte   width;
 102     FT_Byte   height;
 103     FT_Char   left;
 104     FT_Char   top;
 105
 106     FT_Byte   format;
 107     FT_Char   pitch;
 108     FT_Char   xadvance;
 109     FT_Char   yadvance;
 110
 111     FT_Byte*  buffer;
 112
 113   } FTC_SBitRec;
 114
 115
 116   /*************************************************************************/
 117   /*                                                                       */
 118   /* <Function>                                                            */
 119   /*    FTC_SBit_Cache_New                                                 */
 120   /*                                                                       */
 121   /* <Description>                                                         */
 122   /*    Creates a new cache to store small glyph bitmaps.                  */
 123   /*                                                                       */
 124   /* <Input>                                                               */
 125   /*    manager :: A handle to the source cache manager.                   */
 126   /*                                                                       */
 127   /* <Output>                                                              */
 128   /*    acache  :: A handle to the new sbit cache.  NULL in case of error. */
 129   /*                                                                       */
 130   /* <Return>                                                              */
 131   /*    FreeType error code.  0 means success.                             */
 132   /*                                                                       */
 133   FT_EXPORT( FT_Error )
 134   FTC_SBit_Cache_New( FTC_Manager      manager,
 135                       FTC_SBit_Cache  *acache );
 136
 137
 138   /*************************************************************************/
 139   /*                                                                       */
 140   /* <Function>                                                            */
 141   /*    FTC_SBit_Cache_Lookup                                              */
 142   /*                                                                       */
 143   /* <Description>                                                         */
 144   /*    Looks up a given small glyph bitmap in a given sbit cache.         */
 145   /*                                                                       */
 146   /* <Input>                                                               */
 147   /*    cache  :: A handle to the source sbit cache.                       */
 148   /*    desc   :: A pointer to the glyph image descriptor.                 */
 149   /*    gindex :: The glyph index.                                         */
 150   /*                                                                       */
 151   /* <Output>                                                              */
 152   /*    sbit   :: A handle to a small bitmap descriptor.                   */
 153   /*                                                                       */
 154   /* <Return>                                                              */
 155   /*    FreeType error code.  0 means success.                             */
 156   /*                                                                       */
 157   /* <Note>                                                                */
 158   /*    The small bitmap descriptor and its bit buffer are owned by the    */
 159   /*    cache and should never be freed by the application.  They might    */
 160   /*    as well disappear from memory on the next cache lookup, so don't   */
 161   /*    treat them as persistent data.                                     */
 162   /*                                                                       */
 163   /*    The descriptor's `buffer' field is set to 0 to indicate a missing  */
 164   /*    glyph bitmap.                                                      */
 165   /*                                                                       */
 166   FT_EXPORT( FT_Error )
 167   FTC_SBit_Cache_Lookup( FTC_SBit_Cache   cache,
 168                          FTC_Image_Desc*  desc,
 169                          FT_UInt          gindex,
 170                          FTC_SBit        *sbit );
 171
 172
 173   /* */
 174
 175
 176 FT_END_HEADER
 177
 178 #endif /* __FTCSBITS_H__ */
 179
 180
 181 /* END */