shithub: freetype+ttf2subf

ref: 18789bfe9f5b350b37fe5e9fbca36393d5dd777a
dir: /src/type1z/t1driver.c/

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/*******************************************************************
 *
 *  t1driver.c
 *
 *    High-level Type1 driver interface for FreeType 2.0
 *
 *  Copyright 1996-1998 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 <t1driver.h>
#include <t1gload.h>

#include <ftdebug.h>
#include <ftstream.h>

#undef  FT_COMPONENT
#define FT_COMPONENT  trace_t1driver

  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    Get_Interface                                                      */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Each driver can provide one or more extensions to the base         */
  /*    FreeType API.  These can be used to access format specific         */
  /*    features (e.g., all TrueType/OpenType resources share a common     */
  /*    file structure and common tables which can be accessed through the */
  /*    `sfnt' interface), or more simply generic ones (e.g., the          */
  /*    `postscript names' interface which can be used to retrieve the     */
  /*     PostScript name of a given glyph index).                          */
  /*                                                                       */
  /* <InOut>                                                               */
  /*    driver    :: A handle to a driver object.                          */
  /*                                                                       */
  /* <Input>                                                               */
  /*    interface :: A string designing the interface.  Examples are       */
  /*                 `sfnt', `post_names', `charmaps', etc.                */
  /*                                                                       */
  /* <Return>                                                              */
  /*    A typeless pointer to the extension's interface (normally a table  */
  /*    of function pointers).  Returns NULL if the requested extension    */
  /*    isn't available (i.e., wasn't compiled in the driver at build      */
  /*    time).                                                             */
  /*                                                                       */
  static
  void*  Get_Interface( FT_Driver*        driver,
                        const FT_String*  interface )
  {
    UNUSED(driver);
    UNUSED(interface);
    return 0;
  }


  /******************************************************************/
  /*                                                                */
  /* <Function> Set_Char_Sizes                                      */
  /*                                                                */
  /* <Description>                                                  */
  /*    A driver method used to reset a size's character sizes      */
  /*    (horizontal and vertical) expressed in fractional points.   */
  /*                                                                */
  /* <Input>                                                        */
  /*    size        :: handle to target size object                 */
  /*    char_width  :: character width expressed in 26.6 points     */
  /*    char_height :: character height expressed in 26.6 points    */
  /*                                                                */
  /* <Return>                                                       */
  /*    FreeType error code. 0 means success                        */
  /*                                                                */
  static
  T1_Error  Set_Char_Sizes( T1_Size      size,
                            T1_F26Dot6   char_width,
                            T1_F26Dot6   char_height,
                            T1_UInt      horz_resolution,
                            T1_UInt      vert_resolution )
  {
    UNUSED(char_width);
    UNUSED(horz_resolution);
    UNUSED(vert_resolution);

    size->valid = FALSE;
    return T1_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>                                                        */
  /*    size         :: handle to target size object                */
  /*                                                                */
  /*    pixel_width  :: character width expressed in 26.6 points    */
  /*                                                                */
  /*    pixel_height :: character height expressed in 26.6 points   */
  /*                                                                */
  /*    char_size    :: the corresponding character size in points  */
  /*                    This value is only sent to the TrueType     */
  /*                    bytecode interpreter, even though 99% of    */
  /*                    glyph programs will simply ignore it. A     */
  /*                    safe value there is the maximum of the      */
  /*                    pixel width and height (multiplied by       */
  /*                    64 to make it a 26.6 fixed float !)         */
  /* <Return>                                                       */
  /*    FreeType error code. 0 means success                        */
  /*                                                                */
  static
  T1_Error  Set_Pixel_Sizes( T1_Size     size,
                             T1_Int      pixel_width,
                             T1_Int      pixel_height )
  {
    UNUSED(pixel_width);
    UNUSED(pixel_height);

    size->valid = FALSE; 
    return T1_Reset_Size(size);
  }


  /******************************************************************/
  /*                                                                */
  /* <Struct> FT_DriverInterface                                    */
  /*                                                                */
  /* <Description>                                                  */
  /*    A structure used to hold a font driver's basic interface    */
  /*    used by the high-level parts of FreeType (or other apps)    */
  /*                                                                */
  /*    Most scalable drivers provide a specialized interface to    */
  /*    access format-specific features. It can be retrieved with   */
  /*    a call to the "get_format_interface", and should be defined */
  /*    in each font driver header (e.g. ttdriver.h, t1driver.h,..) */
  /*                                                                */
  /*    All fields are function pointers ..                         */
  /*                                                                */
  /*                                                                */
  /* <Fields>                                                       */
  /*                                                                */
  /*    new_engine ::                                               */
  /*        used to create and initialise a new driver object       */
  /*                                                                */
  /*    done_engine ::                                              */
  /*        used to finalise and destroy a given driver object      */
  /*                                                                */
  /*    get_format_interface ::                                     */
  /*        return a typeless pointer to the format-specific        */
  /*        driver interface.                                       */
  /*                                                                */
  /*    new_face ::                                                 */
  /*        create a new face object from a resource                */
  /*                                                                */
  /*    done_face ::                                                */
  /*        discards a face object, as well as all child objects    */
  /*        ( sizes, charmaps, glyph slots )                        */
  /*                                                                */
  /*    get_face_properties ::                                      */
  /*        return generic face properties                          */
  /*                                                                */
  /*    get_kerning ::                                              */
  /*        return the kerning vector corresponding to a pair       */
  /*        of glyphs, expressed in unscaled font units.            */
  /*                                                                */
  /*    new_size ::                                                 */
  /*        create and initialise a new scalable size object.       */
  /*                                                                */
  /*    new_fixed_size ::                                           */
  /*        create and initialise a new fixed-size object.          */
  /*                                                                */
  /*    done_size ::                                                */
  /*        finalize a given face size object.                      */
  /*                                                                */
  /*    set_size_resolutions ::                                     */
  /*        reset a scalable size object's output resolutions       */
  /*                                                                */
  /*    set_size_char_sizes ::                                      */
  /*        reset a scalable size object's character size           */
  /*                                                                */
  /*    set_pixel_sizes ::                                          */
  /*        reset a face size object's pixel dimensions. Applies    */
  /*        to both scalable and fixed faces.                       */
  /*                                                                */
  /*    new_glyph_slot ::                                           */
  /*        create and initialise a new glyph slot                  */
  /*                                                                */
  /*    done_glyph_slot ::                                          */
  /*        discard a given glyph slot                              */
  /*                                                                */
  /*    load_glyph ::                                               */
  /*        load a given glyph into a given slot                    */
  /*                                                                */
  /*    get_glyph_metrics ::                                        */
  /*        return a loaded glyph's metrics.                        */
  /*                                                                */

  EXPORT_FUNC
  const  FT_DriverInterface  t1_driver_interface =
  {
    sizeof( FT_DriverRec ),
    sizeof( T1_FaceRec ),
    sizeof( T1_SizeRec ),
    sizeof( T1_GlyphSlotRec ),
    
    "type1",
    100,  /* driver version == 1.0          */
    200,  /* requires FreeType 2.0 or above */

    0,   /* format interface */

    (FTDriver_initDriver)           T1_Init_Driver,
    (FTDriver_doneDriver)           T1_Done_Driver,
    (FTDriver_getInterface)         Get_Interface,

    (FTDriver_initFace)             T1_Init_Face,
    (FTDriver_doneFace)             T1_Done_Face,
    (FTDriver_getKerning)           0,

    (FTDriver_initSize)             T1_Init_Size,
    (FTDriver_doneSize)             T1_Done_Size,
    (FTDriver_setCharSizes)         Set_Char_Sizes,
    (FTDriver_setPixelSizes)        Set_Pixel_Sizes,

    (FTDriver_initGlyphSlot)        T1_Init_GlyphSlot,
    (FTDriver_doneGlyphSlot)        T1_Done_GlyphSlot,
    (FTDriver_loadGlyph)            T1_Load_Glyph,

    (FTDriver_getCharIndex)         0,
  };

  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    getDriverInterface                                                 */
  /*                                                                       */
  /* <Description>                                                         */
  /*    This function is used when compiling the font 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.                                   */
  /*                                                                       */
#ifdef FT_CONFIG_OPTION_DYNAMIC_DRIVERS

  EXPORT_FUNC
  FT_DriverInterface*  getDriverInterface( void )
  {
    return &t1_driver_interface;
  }

#endif /* CONFIG_OPTION_DYNAMIC_DRIVERS */