ftobjs.c

一个类似windows

    if ( !matrix )
    {
      internal->transform_matrix.xx = 0x10000L;
      internal->transform_matrix.xy = 0;
      internal->transform_matrix.yx = 0;
      internal->transform_matrix.yy = 0x10000L;
      matrix = &internal->transform_matrix;
    }
    else
      internal->transform_matrix = *matrix;

    /* set transform_flags bit flag 0 if `matrix' isn't the identity */
    if ( ( matrix->xy | matrix->yx ) ||
         matrix->xx != 0x10000L      ||
         matrix->yy != 0x10000L      )
      internal->transform_flags |= 1;

    if ( !delta )
    {
      internal->transform_delta.x = 0;
      internal->transform_delta.y = 0;
      delta = &internal->transform_delta;
    }
    else
      internal->transform_delta = *delta;

    /* set transform_flags bit flag 1 if `delta' isn't the null vector */
    if ( delta->x | delta->y )
      internal->transform_flags |= 2;
  }


  static FT_Renderer
  ft_lookup_glyph_renderer( FT_GlyphSlot  slot );


  /* documentation is in freetype.h */

  FT_EXPORT_DEF( FT_Error )
  FT_Load_Glyph( FT_Face   face,
                 FT_UInt   glyph_index,
                 FT_Int32  load_flags )
  {
    FT_Error      error;
    FT_Driver     driver;
    FT_GlyphSlot  slot;
    FT_Library    library;
    FT_Bool       autohint;
    FT_Module     hinter;


    if ( !face || !face->size || !face->glyph )
      return FT_Err_Invalid_Face_Handle;

    if ( glyph_index >= (FT_UInt)face->num_glyphs )
      return FT_Err_Invalid_Argument;

    slot = face->glyph;
    ft_glyphslot_clear( slot );

    driver = face->driver;

    /* if the flag NO_RECURSE is set, we disable hinting and scaling */
    if ( load_flags & FT_LOAD_NO_RECURSE )
    {
      /* disable scaling, hinting, and transformation */
      load_flags |= FT_LOAD_NO_SCALE         |
                    FT_LOAD_NO_HINTING       |
                    FT_LOAD_NO_BITMAP        |
                    FT_LOAD_IGNORE_TRANSFORM;

      /* disable bitmap rendering */
      load_flags &= ~FT_LOAD_RENDER;
    }

    /* do we need to load the glyph through the auto-hinter? */
    library  = driver->root.library;
    hinter   = library->auto_hinter;
    autohint =
      FT_BOOL( hinter                                      &&
               !( load_flags & ( FT_LOAD_NO_SCALE    |
                                 FT_LOAD_NO_HINTING  |
                                 FT_LOAD_NO_AUTOHINT ) )   &&
               FT_DRIVER_IS_SCALABLE( driver )             &&
               FT_DRIVER_USES_OUTLINES( driver )           );
    if ( autohint )
    {
      if ( FT_DRIVER_HAS_HINTER( driver ) &&
           !( load_flags & FT_LOAD_FORCE_AUTOHINT ) )
        autohint = 0;
    }

    /* don't apply autohinting if glyph is vertically distorted or */
    /* mirrored                                                    */
    if ( autohint && !( face->internal->transform_matrix.yy <= 0 ||
                        face->internal->transform_matrix.yx != 0 ) )
    {
      FT_AutoHinter_Service  hinting;


      /* try to load embedded bitmaps first if available            */
      /*                                                            */
      /* XXX: This is really a temporary hack that should disappear */
      /*      promptly with FreeType 2.1!                           */
      /*                                                            */
      if ( FT_HAS_FIXED_SIZES( face )             &&
          ( load_flags & FT_LOAD_NO_BITMAP ) == 0 )
      {
        error = driver->clazz->load_glyph( slot, face->size,
                                           glyph_index,
                                           load_flags | FT_LOAD_SBITS_ONLY );

        if ( !error && slot->format == FT_GLYPH_FORMAT_BITMAP )
          goto Load_Ok;
      }

      /* load auto-hinted outline */
      hinting = (FT_AutoHinter_Service)hinter->clazz->module_interface;

      error   = hinting->load_glyph( (FT_AutoHinter)hinter,
                                     slot, face->size,
                                     glyph_index, load_flags );
    }
    else
    {
      error = driver->clazz->load_glyph( slot,
                                         face->size,
                                         glyph_index,
                                         load_flags );
      if ( error )
        goto Exit;

      /* check that the loaded outline is correct */
      error = FT_Outline_Check( &slot->outline );
      if ( error )
        goto Exit;
    }

  Load_Ok:
    /* compute the advance */
    if ( load_flags & FT_LOAD_VERTICAL_LAYOUT )
    {
      slot->advance.x = 0;
      slot->advance.y = slot->metrics.vertAdvance;
    }
    else
    {
      slot->advance.x = slot->metrics.horiAdvance;
      slot->advance.y = 0;
    }

    /* compute the linear advance in 16.16 pixels */
    if ( ( load_flags & FT_LOAD_LINEAR_DESIGN ) == 0  &&
         ( face->face_flags & FT_FACE_FLAG_SCALABLE ) )
    {
      FT_Size_Metrics*  metrics = &face->size->metrics;


      slot->linearHoriAdvance = FT_MulDiv( slot->linearHoriAdvance,
                                           metrics->x_scale, 64 );

      slot->linearVertAdvance = FT_MulDiv( slot->linearVertAdvance,
                                           metrics->y_scale, 64 );
    }

    if ( ( load_flags & FT_LOAD_IGNORE_TRANSFORM ) == 0 )
    {
      FT_Face_Internal  internal = face->internal;


      /* now, transform the glyph image if needed */
      if ( internal->transform_flags )
      {
        /* get renderer */
        FT_Renderer  renderer = ft_lookup_glyph_renderer( slot );


        if ( renderer )
          error = renderer->clazz->transform_glyph(
                                     renderer, slot,
                                     &internal->transform_matrix,
                                     &internal->transform_delta );
        /* transform advance */
        FT_Vector_Transform( &slot->advance, &internal->transform_matrix );
      }
    }

    /* do we need to render the image now? */
    if ( !error                                    &&
         slot->format != FT_GLYPH_FORMAT_BITMAP    &&
         slot->format != FT_GLYPH_FORMAT_COMPOSITE &&
         load_flags & FT_LOAD_RENDER )
    {
      FT_Render_Mode  mode = FT_LOAD_TARGET_MODE( load_flags );


      if ( mode == FT_RENDER_MODE_NORMAL      &&
           (load_flags & FT_LOAD_MONOCHROME ) )
        mode = FT_RENDER_MODE_MONO;

      error = FT_Render_Glyph( slot, mode );
    }

  Exit:
    return error;
  }


  /* documentation is in freetype.h */

  FT_EXPORT_DEF( FT_Error )
  FT_Load_Char( FT_Face   face,
                FT_ULong  char_code,
                FT_Int32  load_flags )
  {
    FT_UInt  glyph_index;


    if ( !face )
      return FT_Err_Invalid_Face_Handle;

    glyph_index = (FT_UInt)char_code;
    if ( face->charmap )
      glyph_index = FT_Get_Char_Index( face, char_code );

    return FT_Load_Glyph( face, glyph_index, load_flags );
  }


  /* destructor for sizes list */
  static void
  destroy_size( FT_Memory  memory,
                FT_Size    size,
                FT_Driver  driver )
  {
    /* finalize client-specific data */
    if ( size->generic.finalizer )
      size->generic.finalizer( size );

    /* finalize format-specific stuff */
    if ( driver->clazz->done_size )
      driver->clazz->done_size( size );

    FT_FREE( size->internal );
    FT_FREE( size );
  }


  static void
  ft_cmap_done_internal( FT_CMap  cmap );


  static void
  destroy_charmaps( FT_Face    face,
                    FT_Memory  memory )
  {
    FT_Int  n;


    for ( n = 0; n < face->num_charmaps; n++ )
    {
      FT_CMap  cmap = FT_CMAP( face->charmaps[n] );


      ft_cmap_done_internal( cmap );

      face->charmaps[n] = NULL;
    }

    FT_FREE( face->charmaps );
    face->num_charmaps = 0;
  }


  /* destructor for faces list */
  static void
  destroy_face( FT_Memory  memory,
                FT_Face    face,
                FT_Driver  driver )
  {
    FT_Driver_Class  clazz = driver->clazz;


    /* discard auto-hinting data */
    if ( face->autohint.finalizer )
      face->autohint.finalizer( face->autohint.data );

    /* Discard glyph slots for this face.                           */
    /* Beware!  FT_Done_GlyphSlot() changes the field `face->glyph' */
    while ( face->glyph )
      FT_Done_GlyphSlot( face->glyph );

    /* discard all sizes for this face */
    FT_List_Finalize( &face->sizes_list,
                      (FT_List_Destructor)destroy_size,
                      memory,
                      driver );
    face->size = 0;

    /* now discard client data */
    if ( face->generic.finalizer )
      face->generic.finalizer( face );

    /* discard charmaps */
    destroy_charmaps( face, memory );

    /* finalize format-specific stuff */
    if ( clazz->done_face )
      clazz->done_face( face );

    /* close the stream for this face if needed */
    FT_Stream_Free(
      face->stream,
      ( face->face_flags & FT_FACE_FLAG_EXTERNAL_STREAM ) != 0 );

    face->stream = 0;

    /* get rid of it */
    if ( face->internal )
    {
      FT_FREE( face->internal );
    }
    FT_FREE( face );
  }


  static void
  Destroy_Driver( FT_Driver  driver )
  {
    FT_List_Finalize( &driver->faces_list,
                      (FT_List_Destructor)destroy_face,
                      driver->root.memory,
                      driver );

    /* check whether we need to drop the driver's glyph loader */
    if ( FT_DRIVER_USES_OUTLINES( driver ) )
      FT_GlyphLoader_Done( driver->glyph_loader );
  }


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    find_unicode_charmap                                               */
  /*                                                                       */
  /* <Description>                                                         */
  /*    This function finds a Unicode charmap, if there is one.            */
  /*    And if there is more than one, it tries to favour the more         */
  /*    extensive one, i.e., one that supports UCS-4 against those which   */
  /*    are limited to the BMP (said UCS-2 encoding.)                      */
  /*                                                                       */
  /*    This function is called from open_face() (just below), and also    */
  /*    from FT_Select_Charmap( ..., FT_ENCODING_UNICODE).                 */
  /*                                                                       */
  static FT_Error
  find_unicode_charmap( FT_Face  face )
  {
    FT_CharMap*  first;
    FT_CharMap*  cur;
    FT_CharMap*  unicmap = NULL;  /* some UCS-2 map, if we found it */


    /* caller should have already checked that `face' is valid */
    FT_ASSERT( face );

    first = face->charmaps;

    if ( !first )
      return FT_Err_Invalid_CharMap_Handle;

    /*
     *  The original TrueType specification(s) only specified charmap
     *  formats that are capable of mapping 8 or 16 bit character codes to
     *  glyph indices.
     *
     *  However, recent updates to the Apple and OpenType specifications
     *  introduced new formats that are capable of mapping 32-bit character
     *  codes as well.  And these are already used on some fonts, mainly to
     *  map non-BMP Asian ideographs as defined in Unicode.
     *
     *  For compatibility purposes, these fonts generally come with
     *  *several* Unicode charmaps:
     *
     *   - One of them in the "old" 16-bit format, that cannot access
     *     all glyphs in the font.
     *
     *   - Another one in the "new" 32-bit format, that can access all
     *     the glyphs.
     *
     *  This function has been written to always favor a 32-bit charmap
     *  when found.  Otherwise, a 16-bit one is returned when found.
     */

    /* Since the `interesting' table, with IDs (3,10), is normally the */
    /* last one, we loop backwards.  This looses with type1 fonts with */
    /* non-BMP characters (<.0001%), this wins with .ttf with non-BMP  */
    /* chars (.01% ?), and this is the same about 99.99% of the time!  */

    cur = first + face->num_charmaps;  /* points after the last one */

    for ( ; --cur >= first; )
    {
      if ( cur[0]->encoding == FT_ENCODING_UNICODE )
      {
        unicmap = cur;  /* record we found a Unicode charmap */

        /* XXX If some new encodings to represent UCS-4 are added,  */
        /*     they should be added here.                           */
        if ( ( cur[0]->platform_id == TT_PLATFORM_MICROSOFT &&
               cur[0]->encoding_id == TT_MS_ID_UCS_4        )          ||
             ( cur[0]->platform_id == TT_PLATFORM_APPLE_UNICODE &&
               cur[0]->encoding_id == TT_APPLE_ID_UNICODE_32    )      )

        /* Hurray!  We found a UCS-4 charmap.  We can stop the scan! */
        {
          face->charmap = cur[0];
          return 0;
        }
      }
    }

    /* We do not have any UCS-4 charmap.  Sigh.                         */
    /* Let's see if we have some other kind of Unicode charmap, though. */
    if ( unicmap != NULL )
    {
      face->charmap = unicmap[0];
      return 0;
    }

    /* Chou blanc! */
    return FT_Err_Invalid_CharMap_Handle;
  }


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    open_face                                                          */
  /*                                                                       */
  /* <Description>                                                         */