t1driver.c

Qt/Embedded是一个多平台的C++图形用户界面应用程序框架

/*******************************************************************
 *
 *  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 <t1afm.h>

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

#undef  FT_COMPONENT
#define FT_COMPONENT  trace_t1driver

#ifndef T1_CONFIG_OPTION_NO_AFM
  /*************************************************************************/
  /*                                                                       */
  /* <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
  FTDriver_Interface  Get_Interface( FT_Driver         driver,
                                     const FT_String*  interface )
  {
    if ( strcmp( (const char*)interface, "attach_file" ) == 0 )
      return (FTDriver_Interface)T1_Read_AFM;
      
    return 0;
  }



  /*************************************************************************/
  /*                                                                       */
  /* <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
  T1_Error  Get_Kerning( T1_Face     face,
                         T1_UInt     left_glyph,
                         T1_UInt     right_glyph,
                         T1_Vector*  kerning )
  {
    T1_AFM*  afm;
    
    kerning->x = 0;
    kerning->y = 0;

    afm = (T1_AFM*)face->afm_data;
    if (afm)
      T1_Get_Kerning( afm, left_glyph, right_glyph, kerning );

    return T1_Err_Ok;
  }
#endif

  /******************************************************************/
  /*                                                                */
  /* <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);
  }

  /*************************************************************************/
  /*                                                                       */
  /* <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
  T1_UInt  Get_Char_Index( FT_CharMap  charmap,
                           T1_Long     charcode )
  {
    T1_Face             face;
    T1_UInt             result = 0;
    PSNames_Interface*  psnames;

    face = (T1_Face)charmap->face;
    psnames = (PSNames_Interface*)face->psnames;
    if (psnames)    
      switch (charmap->encoding)
      {
       /********************************************************************/
       /*                                                                  */
       /* Unicode encoding support                                         */
       /*                                                                  */
        case ft_encoding_unicode:
          {
            /* use the "psnames" module to synthetize the Unicode charmap */
            result = psnames->lookup_unicode( &face->unicode_map,
                                              (T1_ULong)charcode );

            /* the function returns 0xFFFF when the Unicode charcode has */
            /* no corresponding glyph..                                  */
            if (result == 0xFFFF)
              result = 0;
            goto Exit;
          }
  
       /********************************************************************/
       /*                                                                  */
       /* Custom Type 1 encoding                                           */
       /*                                                                  */
        case ft_encoding_adobe_custom:
          {
            T1_Encoding*  encoding = &face->type1.encoding;
            if (charcode >= encoding->code_first &&
                charcode <= encoding->code_last)
            {
              result = encoding->char_index[charcode];
            }
            goto Exit;
          }
          
       /********************************************************************/
       /*                                                                  */
       /* Adobe Standard & Expert encoding support                         */
       /*                                                                  */
       default: