ttdriver.c

来自「一个类似windows」· C语言 代码 · 共 432 行 · 第 1/2 页

  /*    Set_Pixel_Sizes                                                    */
  /*                                                                       */
  /* <Description>                                                         */
  /*    A driver method used to reset a size's character sizes (horizontal */
  /*    and vertical) expressed in integer pixels.                         */
  /*                                                                       */
  /* <InOut>                                                               */
  /*    size         :: A handle to the target size object.                */
  /*                                                                       */
  /* <Return>                                                              */
  /*    FreeType error code.  0 means success.                             */
  /*                                                                       */
  static FT_Error
  Set_Pixel_Sizes( FT_Size  ttsize,         /* TT_Size */
                   FT_UInt  pixel_width,
                   FT_UInt  pixel_height )
  {
    TT_Size  size = (TT_Size)ttsize;

    FT_UNUSED( pixel_width );
    FT_UNUSED( pixel_height );


    /* many things have been pre-computed by the base layer */

    size->metrics         = size->root.metrics;
    size->ttmetrics.valid = FALSE;
#ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS
    size->strike_index    = 0xFFFFU;
#endif

    return tt_size_reset( size );
  }


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    Load_Glyph                                                         */
  /*                                                                       */
  /* <Description>                                                         */
  /*    A driver method used to load a glyph within a given glyph slot.    */
  /*                                                                       */
  /* <Input>                                                               */
  /*    slot        :: A handle to the target slot object where the glyph  */
  /*                   will be loaded.                                     */
  /*                                                                       */
  /*    size        :: A handle to the source face size at which the glyph */
  /*                   must be scaled, loaded, etc.                        */
  /*                                                                       */
  /*    glyph_index :: The index of the glyph in the font file.            */
  /*                                                                       */
  /*    load_flags  :: A flag indicating what to load for this glyph.  The */
  /*                   FTLOAD_??? constants can be used to control the     */
  /*                   glyph loading process (e.g., whether the outline    */
  /*                   should be scaled, whether to load bitmaps or not,   */
  /*                   whether to hint the outline, etc).                  */
  /*                                                                       */
  /* <Return>                                                              */
  /*    FreeType error code.  0 means success.                             */
  /*                                                                       */
  static FT_Error
  Load_Glyph( FT_GlyphSlot  ttslot,         /* TT_GlyphSlot */
              FT_Size       ttsize,         /* TT_Size      */
              FT_UInt       glyph_index,
              FT_Int32      load_flags )
  {
    TT_GlyphSlot  slot = (TT_GlyphSlot)ttslot;
    TT_Size       size = (TT_Size)ttsize;
    FT_Error      error;


    if ( !slot )
      return TT_Err_Invalid_Slot_Handle;

    /* check whether we want a scaled outline or bitmap */
    if ( !size )
      load_flags |= FT_LOAD_NO_SCALE | FT_LOAD_NO_HINTING;

    if ( load_flags & FT_LOAD_NO_SCALE )
      size = NULL;

    /* reset the size object if necessary */
    if ( size )
    {
      /* these two object must have the same parent */
      if ( size->root.face != slot->face )
        return TT_Err_Invalid_Face_Handle;

      if ( !size->ttmetrics.valid )
      {
        if ( FT_SET_ERROR( tt_size_reset( size ) ) )
          return error;
      }
    }

    /* now load the glyph outline if necessary */
    error = TT_Load_Glyph( size, slot, glyph_index, load_flags );

    /* force drop-out mode to 2 - irrelevant now */
    /* slot->outline.dropout_mode = 2; */

    return error;
  }


  /*************************************************************************/
  /*************************************************************************/
  /*************************************************************************/
  /****                                                                 ****/
  /****                                                                 ****/
  /****                D R I V E R  I N T E R F A C E                   ****/
  /****                                                                 ****/
  /****                                                                 ****/
  /*************************************************************************/
  /*************************************************************************/
  /*************************************************************************/

#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
  static const FT_Service_MultiMastersRec  tt_service_gx_multi_masters =
  {
    (FT_Get_MM_Func)        NULL,
    (FT_Set_MM_Design_Func) NULL,
    (FT_Set_MM_Blend_Func)  TT_Set_MM_Blend,
    (FT_Get_MM_Var_Func)    TT_Get_MM_Var,
    (FT_Set_Var_Design_Func)TT_Set_Var_Design
  };
#endif


  static const FT_ServiceDescRec  tt_services[] =
  {
    { FT_SERVICE_ID_XF86_NAME,     FT_XF86_FORMAT_TRUETYPE },
#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
    { FT_SERVICE_ID_MULTI_MASTERS, &tt_service_gx_multi_masters },
#endif
    { NULL, NULL }
  };


  FT_CALLBACK_DEF( FT_Module_Interface )
  tt_get_interface( FT_Module    driver,    /* TT_Driver */
                    const char*  tt_interface )
  {
    FT_Module_Interface  result;
    FT_Module            sfntd;
    SFNT_Service         sfnt;


    result = ft_service_list_lookup( tt_services, tt_interface );
    if ( result != NULL )
      return result;

    /* only return the default interface from the SFNT module */
    sfntd = FT_Get_Module( driver->library, "sfnt" );
    if ( sfntd )
    {
      sfnt = (SFNT_Service)( sfntd->clazz->module_interface );
      if ( sfnt )
        return sfnt->get_interface( driver, tt_interface );
    }

    return 0;
  }


  /* The FT_DriverInterface structure is defined in ftdriver.h. */

  FT_CALLBACK_TABLE_DEF
  const FT_Driver_ClassRec  tt_driver_class =
  {
    {
      FT_MODULE_FONT_DRIVER        |
      FT_MODULE_DRIVER_SCALABLE    |
#ifdef TT_CONFIG_OPTION_BYTECODE_INTERPRETER
      FT_MODULE_DRIVER_HAS_HINTER,
#else
      0,
#endif

      sizeof ( TT_DriverRec ),

      "truetype",      /* driver name                           */
      0x10000L,        /* driver version == 1.0                 */
      0x20000L,        /* driver requires FreeType 2.0 or above */

      (void*)0,        /* driver specific interface */

      tt_driver_init,
      tt_driver_done,
      tt_get_interface,
    },

    sizeof ( TT_FaceRec ),
    sizeof ( TT_SizeRec ),
    sizeof ( FT_GlyphSlotRec ),

    tt_face_init,
    tt_face_done,
    tt_size_init,
    tt_size_done,
    0,                      /* FT_Slot_InitFunc        */
    0,                      /* FT_Slot_DoneFunc        */

    Set_Char_Sizes,
    Set_Pixel_Sizes,
    Load_Glyph,

    tt_get_kerning,
    0,                      /* FT_Face_AttachFunc      */
    0                       /* FT_Face_GetAdvancesFunc */
  };


/* END */