kc3-lang/freetype/src/truetype/ttdriver.c

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• Hash : c6a92202
  Author :
  Date : 2000-07-04T18:12:13
  

  various clean-ups: - using FT_UNUSED instead of UNUSED - using FT_LONG64 and FT_INT64 instead of LONG64 & INT64 - using FT_SIZEOF_INT & FT_SIZEOF_LONG instead of... - removed the #ifdefs that used SIZEOF_INT, instead we now use FT_Int32 and FT_UInt32 when needed to support 32-bits quantity correctly on 64-bits systems..

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• src/truetype/ttdriver.c

• /***************************************************************************/
  /*                                                                         */
  /*  ttdriver.c                                                             */
  /*                                                                         */
  /*    TrueType font driver implementation (body).                          */
  /*                                                                         */
  /*  Copyright 1996-2000 by                                                 */
  /*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
  /*                                                                         */
  /*  This file is part of the FreeType project, and may only be used,       */
  /*  modified, and distributed under the terms of the FreeType project      */
  /*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
  /*  this file you indicate that you have read the license and              */
  /*  understand and accept it fully.                                        */
  /*                                                                         */
  /***************************************************************************/
  
  
  #include <freetype/internal/ftdebug.h>
  #include <freetype/internal/ftstream.h>
  #include <freetype/internal/sfnt.h>
  #include <freetype/ttnameid.h>
  
  #include <ttdriver.h>
  #include <ttgload.h>
  
  
    /*************************************************************************/
    /*                                                                       */
    /* The macro FT_COMPONENT is used in trace mode.  It is an implicit      */
    /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log  */
    /* messages during execution.                                            */
    /*                                                                       */
  #undef  FT_COMPONENT
  #define FT_COMPONENT  trace_ttdriver
  
  
    /*************************************************************************/
    /*************************************************************************/
    /*************************************************************************/
    /****                                                                 ****/
    /****                                                                 ****/
    /****                          F A C E S                              ****/
    /****                                                                 ****/
    /****                                                                 ****/
    /*************************************************************************/
    /*************************************************************************/
    /*************************************************************************/
  
  
  #undef  PAIR_TAG
  #define PAIR_TAG( left, right )  ( ( (FT_ULong)left << 16 ) | \
                                       (FT_ULong)right        )
  
  
    /*************************************************************************/
    /*                                                                       */
    /* <Function>                                                            */
    /*    Get_Kerning                                                        */
    /*                                                                       */
    /* <Description>                                                         */
    /*    A driver method used to return the kerning vector between two      */
    /*    glyphs of the same face.                                           */
    /*                                                                       */
    /* <Input>                                                               */
    /*    face        :: A handle to the source face object.                 */
    /*                                                                       */
    /*    left_glyph  :: The index of the left glyph in the kern pair.       */
    /*                                                                       */
    /*    right_glyph :: The index of the right glyph in the kern pair.      */
    /*                                                                       */
    /* <Output>                                                              */
    /*    kerning     :: The kerning vector.  This is in font units for      */
    /*                   scalable formats, and in pixels for fixed-sizes     */
    /*                   formats.                                            */
    /*                                                                       */
    /* <Return>                                                              */
    /*    FreeType error code.  0 means success.                             */
    /*                                                                       */
    /* <Note>                                                                */
    /*    Only horizontal layouts (left-to-right & right-to-left) are        */
    /*    supported by this function.  Other layouts, or more sophisticated  */
    /*    kernings, are out of scope of this method (the basic driver        */
    /*    interface is meant to be simple).                                  */
    /*                                                                       */
    /*    They can be implemented by format-specific interfaces.             */
    /*                                                                       */
    static
    FT_Error  Get_Kerning( TT_Face     face,
                           FT_UInt     left_glyph,
                           FT_UInt     right_glyph,
                           FT_Vector*  kerning )
    {
      TT_Kern_0_Pair*  pair;
  
  
      if ( !face )
        return TT_Err_Invalid_Face_Handle;
  
      kerning->x = 0;
      kerning->y = 0;
  
      if ( face->kern_pairs )
      {
        /* there are some kerning pairs in this font file! */
        FT_ULong  search_tag = PAIR_TAG( left_glyph, right_glyph );
        FT_Long   left, right;
  
  
        left  = 0;
        right = face->num_kern_pairs - 1;
  
        while ( left <= right )
        {
          FT_Int    middle = left + ( ( right - left ) >> 1 );
          FT_ULong  cur_pair;
  
  
          pair     = face->kern_pairs + middle;
          cur_pair = PAIR_TAG( pair->left, pair->right );
  
          if ( cur_pair == search_tag )
            goto Found;
  
          if ( cur_pair < search_tag )
            left = middle + 1;
          else
            right = middle - 1;
        }
      }
  
    Exit:
      return TT_Err_Ok;
  
    Found:
      kerning->x = pair->value;
      goto Exit;
    }
  
  
  #undef PAIR_TAG
  
  
    /*************************************************************************/
    /*************************************************************************/
    /*************************************************************************/
    /****                                                                 ****/
    /****                                                                 ****/
    /****                           S I Z E S                             ****/
    /****                                                                 ****/
    /****                                                                 ****/
    /*************************************************************************/
    /*************************************************************************/
    /*************************************************************************/
  
  
    /*************************************************************************/
    /*                                                                       */
    /* <Function>                                                            */
    /*    Set_Char_Sizes                                                     */
    /*                                                                       */
    /* <Description>                                                         */
    /*    A driver method used to reset a size's character sizes (horizontal */
    /*    and vertical) expressed in fractional points.                      */
    /*                                                                       */
    /* <Input>                                                               */
    /*    char_width      :: The character width expressed in 26.6           */
    /*                       fractional points.                              */
    /*                                                                       */
    /*    char_height     :: The character height expressed in 26.6          */
    /*                       fractional points.                              */
    /*                                                                       */
    /*    horz_resolution :: The horizontal resolution of the output device. */
    /*                                                                       */
    /*    vert_resolution :: The vertical resolution of the output device.   */
    /*                                                                       */
    /* <InOut>                                                               */
    /*    size            :: A handle to the target size object.             */
    /*                                                                       */
    /* <Return>                                                              */
    /*    FreeType error code.  0 means success.                             */
    /*                                                                       */
    static
    FT_Error  Set_Char_Sizes( TT_Size     size,
                              FT_F26Dot6  char_width,
                              FT_F26Dot6  char_height,
                              FT_UInt     horz_resolution,
                              FT_UInt     vert_resolution )
    {
      FT_Size_Metrics*  metrics = &size->root.metrics;
      TT_Face           face    = (TT_Face)size->root.face;
      FT_Long           dim_x, dim_y;
  
  
      /* This bit flag, when set, indicates that the pixel size must be */
      /* truncated to an integer.  Nearly all TrueType fonts have this  */
      /* bit set, as hinting won't work really well otherwise.          */
      /*                                                                */
      /* However, for those rare fonts who do not set it, we override   */
      /* the default computations performed by the base layer.  I       */
      /* really don't know whether this is useful, but hey, that's the  */
      /* spec :-)                                                       */
      /*                                                                */
      if ( ( face->header.Flags & 8 ) == 0 )
      {
        /* Compute pixel sizes in 26.6 units */
        dim_x = ( char_width  * horz_resolution ) / 72;
        dim_y = ( char_height * vert_resolution ) / 72;
  
        metrics->x_scale = FT_DivFix( dim_x, face->root.units_per_EM );
        metrics->y_scale = FT_DivFix( dim_y, face->root.units_per_EM );
  
        metrics->x_ppem  = (FT_UShort)( dim_x >> 6 );
        metrics->y_ppem  = (FT_UShort)( dim_y >> 6 );
      }
  
      size->ttmetrics.valid = FALSE;
  
      return TT_Reset_Size( size );
    }
  
  
    /*************************************************************************/
    /*                                                                       */
    /* <Function>                                                            */
    /*    Set_Pixel_Sizes                                                    */
    /*                                                                       */
    /* <Description>                                                         */
    /*    A driver method used to reset a size's character sizes (horizontal */
    /*    and vertical) expressed in integer pixels.                         */
    /*                                                                       */
    /* <Input>                                                               */
    /*    pixel_width  :: The character width expressed in integer pixels.   */
    /*                                                                       */
    /*    pixel_height :: The character height 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( TT_Size  size,
                               FT_UInt  pixel_width,
                               FT_UInt  pixel_height )
    {
      FT_UNUSED( pixel_width );
      FT_UNUSED( pixel_height );
  
      /* many things have been pre-computed by the base layer */
  
      size->ttmetrics.valid = FALSE;
  
      return TT_Reset_Size( 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( TT_GlyphSlot  slot,
                          TT_Size       size,
                          FT_UShort     glyph_index,
                          FT_UInt       load_flags )
    {
      FT_Error  error;
  
  
      if ( !slot )
        return TT_Err_Invalid_Glyph_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_Reset_Size( 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;
    }
  
  
    /*************************************************************************/
    /*************************************************************************/
    /*************************************************************************/
    /****                                                                 ****/
    /****                                                                 ****/
    /****             C H A R A C T E R   M A P P I N G S                 ****/
    /****                                                                 ****/
    /****                                                                 ****/
    /*************************************************************************/
    /*************************************************************************/
    /*************************************************************************/
  
    /*************************************************************************/
    /*                                                                       */
    /* <Function>                                                            */
    /*    Get_Char_Index                                                     */
    /*                                                                       */
    /* <Description>                                                         */
    /*    Uses a charmap to return a given character code's glyph index.     */
    /*                                                                       */
    /* <Input>                                                               */
    /*    charmap  :: A handle to the source charmap object.                 */
    /*    charcode :: The character code.                                    */
    /*                                                                       */
    /* <Return>                                                              */
    /*    Glyph index.  0 means `undefined character code'.                  */
    /*                                                                       */
    static
    FT_UInt  Get_Char_Index( TT_CharMap  charmap,
                             FT_Long     charcode )
    {
      FT_Error       error;
      TT_Face        face;
      TT_CMapTable*  cmap;
  
  
      cmap = &charmap->cmap;
      face = (TT_Face)charmap->root.face;
  
      /* Load table if needed */
      if ( !cmap->loaded )
      {
        SFNT_Interface*  sfnt = (SFNT_Interface*)face->sfnt;
  
  
        error = sfnt->load_charmap( face, cmap, face->root.stream );
        if ( error )
          return 0;
  
        cmap->loaded = TRUE;
      }
  
      if ( cmap->get_index )
        return cmap->get_index( cmap, charcode );
      else
        return 0;
    }
  
  
    /*************************************************************************/
    /*************************************************************************/
    /*************************************************************************/
    /****                                                                 ****/
    /****                                                                 ****/
    /****                D R I V E R  I N T E R F A C E                   ****/
    /****                                                                 ****/
    /****                                                                 ****/
    /*************************************************************************/
    /*************************************************************************/
    /*************************************************************************/
  
  
    static
    FT_Module_Interface  tt_get_interface( TT_Driver    driver,
                                           const char*  interface )
    {
      FT_Module        sfntd = FT_Get_Module( driver->root.root.library,
                                              "sfnt" );
      SFNT_Interface*  sfnt;
  
  
      /* only return the default interface from the SFNT module */
      if ( sfntd )
      {
        sfnt = (SFNT_Interface*)( sfntd->clazz->module_interface );
        if ( sfnt )
          return sfnt->get_interface( FT_MODULE( driver ), interface );
      }
  
      return 0;
    }
  
  
    /* The FT_DriverInterface structure is defined in ftdriver.h. */
  
    const FT_Driver_Class  tt_driver_class =
    {
      {
        ft_module_font_driver     |
        ft_module_driver_scalable |
        ft_module_driver_has_hinter,
        
        sizeof ( TT_DriverRec ),
      
        "truetype",      /* driver name                           */
        0x10000L,        /* driver version == 1.0                 */
        0x20000L,        /* driver requires FreeType 2.0 or above */
    
        (void*)0,        /* driver specific interface */
    
        (FT_Module_Constructor)TT_Init_Driver,
        (FT_Module_Destructor) TT_Done_Driver,
        (FT_Module_Requester)  tt_get_interface,
      },
      
      sizeof ( TT_FaceRec ),
      sizeof ( TT_SizeRec ),
      sizeof ( FT_GlyphSlotRec ),
  
  
      (FTDriver_initFace)     TT_Init_Face,
      (FTDriver_doneFace)     TT_Done_Face,
      (FTDriver_initSize)     TT_Init_Size,
      (FTDriver_doneSize)     TT_Done_Size,
      (FTDriver_initGlyphSlot)0,
      (FTDriver_doneGlyphSlot)0,
  
      (FTDriver_setCharSizes) Set_Char_Sizes,
      (FTDriver_setPixelSizes)Set_Pixel_Sizes,
      (FTDriver_loadGlyph)    Load_Glyph,
      (FTDriver_getCharIndex) Get_Char_Index,
      
      (FTDriver_getKerning)   Get_Kerning,
      (FTDriver_attachFile)   0,
      (FTDriver_getAdvances)  0
    };
  
  
  #ifdef FT_CONFIG_OPTION_DYNAMIC_DRIVERS
  
  
    /*************************************************************************/
    /*                                                                       */
    /* <Function>                                                            */
    /*    getDriverInterface                                                 */
    /*                                                                       */
    /* <Description>                                                         */
    /*    This function is used when compiling the TrueType driver as a      */
    /*    shared library (`.DLL' or `.so').  It will be used by the          */
    /*    high-level library of FreeType to retrieve the address of the      */
    /*    driver's generic interface.                                        */
    /*                                                                       */
    /*    It shouldn't be implemented in a static build, as each driver must */
    /*    have the same function as an exported entry point.                 */
    /*                                                                       */
    /* <Return>                                                              */
    /*    The address of the TrueType's driver generic interface.  The       */
    /*    format-specific interface can then be retrieved through the method */
    /*    interface->get_format_interface.                                   */
    /*                                                                       */
    EXPORT_FUNC( const FT_Driver_Class* )  getDriverClass( void )
    {
      return &tt_driver_class;
    }
  
  
  #endif /* CONFIG_OPTION_DYNAMIC_DRIVERS */
  
  
  /* END */
  

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