include/freetype/internal/ftdriver.h

   1 /***************************************************************************/
   2 /*                                                                         */
   3 /*  ftdriver.h                                                             */
   4 /*                                                                         */
   5 /*    FreeType font driver interface (specification).                      */
   6 /*                                                                         */
   7 /*  Copyright 1996-2000 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 FTDRIVER_H
  20 #define FTDRIVER_H
  21
  22
  23 #include <freetype/ftmodule.h>
  24 #include <freetype/config/ftconfig.h>
  25
  26
  27   typedef FT_Error  (*FTDriver_initFace)( FT_Stream      stream,
  28                                           FT_Face        face,
  29                                           FT_Int         typeface_index,
  30                                           FT_Int         num_params,
  31                                           FT_Parameter*  parameters );
  32
  33   typedef void  (*FTDriver_doneFace)( FT_Face  face );
  34
  35
  36   typedef FT_Error  (*FTDriver_initSize)( FT_Size  size );
  37
  38   typedef void  (*FTDriver_doneSize)( FT_Size  size );
  39
  40
  41   typedef FT_Error  (*FTDriver_initGlyphSlot)( FT_GlyphSlot  slot );
  42
  43   typedef void  (*FTDriver_doneGlyphSlot)( FT_GlyphSlot  slot );
  44
  45
  46   typedef FT_Error  (*FTDriver_setCharSizes)( FT_Size     size,
  47                                               FT_F26Dot6  char_width,
  48                                               FT_F26Dot6  char_height,
  49                                               FT_UInt     horz_resolution,
  50                                               FT_UInt     vert_resolution );
  51
  52   typedef FT_Error  (*FTDriver_setPixelSizes)( FT_Size  size,
  53                                                FT_UInt  pixel_width,
  54                                                FT_UInt  pixel_height );
  55
  56   typedef FT_Error  (*FTDriver_loadGlyph)( FT_GlyphSlot  slot,
  57                                            FT_Size       size,
  58                                            FT_UInt       glyph_index,
  59                                            FT_Int        load_flags );
  60
  61
  62   typedef FT_UInt  (*FTDriver_getCharIndex)( FT_CharMap  charmap,
  63                                              FT_Long     charcode );
  64
  65   typedef FT_Error  (*FTDriver_getKerning)( FT_Face      face,
  66                                             FT_UInt      left_glyph,
  67                                             FT_UInt      right_glyph,
  68                                             FT_Vector*   kerning );
  69
  70
  71   typedef FT_Error  (*FTDriver_attachFile)( FT_Face    face,
  72                                             FT_Stream  stream );
  73
  74
  75   typedef FT_Error  (*FTDriver_getAdvances)( FT_Face     face,
  76                                              FT_UInt     first,
  77                                              FT_UInt     count,
  78                                              FT_Bool     vertical,
  79                                              FT_UShort*  advances );
  80
  81
  82   /*************************************************************************/
  83   /*                                                                       */
  84   /* <Struct>                                                              */
  85   /*    FT_Driver_Class                                                    */
  86   /*                                                                       */
  87   /* <Description>                                                         */
  88   /*    The font driver class.  This structure mostly contains pointers to */
  89   /*    driver methods.                                                    */
  90   /*                                                                       */
  91   /* <Fields>                                                              */
  92   /*    root             :: The parent module.                             */
  93   /*                                                                       */
  94   /*    face_object_size :: The size of a face object in bytes.            */
  95   /*                                                                       */
  96   /*    size_object_size :: The size of a size object in bytes.            */
  97   /*                                                                       */
  98   /*    slot_object_size :: The size of a glyph object in bytes.           */
  99   /*                                                                       */
 100   /*    init_face        :: The format-specific face constructor.          */
 101   /*                                                                       */
 102   /*    done_face        :: The format-specific face destructor.           */
 103   /*                                                                       */
 104   /*    init_size        :: The format-specific size constructor.          */
 105   /*                                                                       */
 106   /*    done_size        :: The format-specific size destructor.           */
 107   /*                                                                       */
 108   /*    init_slot        :: The format-specific slot constructor.          */
 109   /*                                                                       */
 110   /*    done_slot        :: The format-specific slot destructor.           */
 111   /*                                                                       */
 112   /*    set_char_sizes   :: A handle to a function used to set the new     */
 113   /*                        character size in points + resolution.  Can be */
 114   /*                        set to 0 to indicate default behaviour.        */
 115   /*                                                                       */
 116   /*    set_pixel_sizes  :: A handle to a function used to set the new     */
 117   /*                        character size in pixels.  Can be set to 0 to  */
 118   /*                        indicate default behaviour.                    */
 119   /*                                                                       */
 120   /*    load_glyph       :: A function handle to load a given glyph image  */
 121   /*                        in a slot.  This field is mandatory!           */
 122   /*                                                                       */
 123   /*    get_char_index   :: A function handle to return the glyph index of */
 124   /*                        a given character for a given charmap.  This   */
 125   /*                        field is mandatory!                            */
 126   /*                                                                       */
 127   /*    get_kerning      :: A function handle to return the unscaled       */
 128   /*                        kerning for a given pair of glyphs.  Can be    */
 129   /*                        set to 0 if the format doesn't support         */
 130   /*                        kerning.                                       */
 131   /*                                                                       */
 132   /*    attach_file      :: This function handle is used to read           */
 133   /*                        additional data for a face from another        */
 134   /*                        file/stream.  For example, this can be used to */
 135   /*                        add data from AFM or PFM files on a Type 1     */
 136   /*                        face, or a CIDMap on a CID-keyed face.         */
 137   /*                                                                       */
 138   /*    get_advances     :: A function handle used to return the advances  */
 139   /*                        of 'count' glyphs, starting at `index'.  the   */
 140   /*                        `vertical' flags must be set when vertical     */
 141   /*                        advances are queried.  The advances buffer is  */
 142   /*                        caller-allocated.                              */
 143   /*                                                                       */
 144   /* <Note>                                                                */
 145   /*    Most function pointers, with the exception of `load_glyph' and     */
 146   /*    `get_char_index' can be set to 0 to indicate a default behaviour.  */
 147   /*                                                                       */
 148   typedef struct  FT_Driver_Class_
 149   {
 150     FT_Module_Class         root;
 151
 152     FT_Int                  face_object_size;
 153     FT_Int                  size_object_size;
 154     FT_Int                  slot_object_size;
 155
 156     FTDriver_initFace       init_face;
 157     FTDriver_doneFace       done_face;
 158
 159     FTDriver_initSize       init_size;
 160     FTDriver_doneSize       done_size;
 161
 162     FTDriver_initGlyphSlot  init_slot;
 163     FTDriver_doneGlyphSlot  done_slot;
 164
 165     FTDriver_setCharSizes   set_char_sizes;
 166     FTDriver_setPixelSizes  set_pixel_sizes;
 167
 168     FTDriver_loadGlyph      load_glyph;
 169     FTDriver_getCharIndex   get_char_index;
 170
 171     FTDriver_getKerning     get_kerning;
 172     FTDriver_attachFile     attach_file;
 173
 174     FTDriver_getAdvances    get_advances;
 175
 176   } FT_Driver_Class;
 177
 178
 179 #endif /* FTDRIVER_H */
 180
 181
 182 /* END */