ttgload.c

奇趣公司比较新的qt/emd版本

        loader->linear     = advance_width;
      }
    }

    /* Set `offset' to the start of the glyph relative to the start of */
    /* the `glyf' table, and `byte_len' to the length of the glyph in  */
    /* bytes.                                                          */

#ifdef FT_CONFIG_OPTION_INCREMENTAL

    /* If we are loading glyph data via the incremental interface, set */
    /* the loader stream to a memory stream reading the data returned  */
    /* by the interface.                                               */
    if ( face->root.internal->incremental_interface )
    {
      error = face->root.internal->incremental_interface->funcs->get_glyph_data(
                face->root.internal->incremental_interface->object,
                glyph_index, &glyph_data );
      if ( error )
        goto Exit;

      glyph_data_loaded = 1;
      offset            = 0;
      loader->byte_len  = glyph_data.length;

      FT_MEM_ZERO( &inc_stream, sizeof ( inc_stream ) );
      FT_Stream_OpenMemory( &inc_stream,
                            glyph_data.pointer, glyph_data.length );

      loader->stream = &inc_stream;
    }
    else

#endif /* FT_CONFIG_OPTION_INCREMENTAL */

      offset = tt_face_get_location( face, glyph_index,
                                     (FT_UInt*)&loader->byte_len );

    if ( loader->byte_len == 0 )
    {
      /* as described by Frederic Loyer, these are spaces or */
      /* the unknown glyph.                                  */
      loader->bbox.xMin = 0;
      loader->bbox.xMax = 0;
      loader->bbox.yMin = 0;
      loader->bbox.yMax = 0;

      TT_LOADER_SET_PP( loader );

#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT

      if ( ((TT_Face)(loader->face))->doblend )
      {
        /* this must be done before scaling */
        FT_Memory  memory = loader->face->memory;


        error = TT_Vary_Get_Glyph_Deltas( (TT_Face)(loader->face),
                                          glyph_index, &deltas, 4 );
        if ( error )
          goto Exit;

        loader->pp1.x += deltas[0].x; loader->pp1.y += deltas[0].y;
        loader->pp2.x += deltas[1].x; loader->pp2.y += deltas[1].y;
        loader->pp3.x += deltas[2].x; loader->pp3.y += deltas[2].y;
        loader->pp4.x += deltas[3].x; loader->pp4.y += deltas[3].y;

        FT_FREE( deltas );
      }

#endif

      if ( ( loader->load_flags & FT_LOAD_NO_SCALE ) == 0 )
      {
        loader->pp1.x = FT_MulFix( loader->pp1.x, x_scale );
        loader->pp2.x = FT_MulFix( loader->pp2.x, x_scale );
        loader->pp3.y = FT_MulFix( loader->pp3.y, y_scale );
        loader->pp4.y = FT_MulFix( loader->pp4.y, y_scale );
      }

      error = TT_Err_Ok;
      goto Exit;
    }

    error = face->access_glyph_frame( loader, glyph_index,
                                      loader->glyf_offset + offset,
                                      loader->byte_len );
    if ( error )
      goto Exit;

    opened_frame = 1;

    /* read first glyph header */
    error = face->read_glyph_header( loader );
    if ( error )
      goto Exit;

    TT_LOADER_SET_PP( loader );

    /***********************************************************************/
    /***********************************************************************/
    /***********************************************************************/

    /* if it is a simple glyph, load it */

    if ( loader->n_contours >= 0 )
    {
      error = face->read_simple_glyph( loader );
      if ( error )
        goto Exit;

      /* all data have been read */
      face->forget_glyph_frame( loader );
      opened_frame = 0;

      error = TT_Process_Simple_Glyph( loader );
      if ( error )
        goto Exit;

      FT_GlyphLoader_Add( gloader );
    }

    /***********************************************************************/
    /***********************************************************************/
    /***********************************************************************/

    /* otherwise, load a composite! */
    else if ( loader->n_contours == -1 )
    {
      FT_UInt       start_point;
      FT_UInt       start_contour;
      FT_ULong      ins_pos;  /* position of composite instructions, if any */


      start_point   = gloader->base.outline.n_points;
      start_contour = gloader->base.outline.n_contours;

      /* for each subglyph, read composite header */
      error = face->read_composite_glyph( loader );
      if ( error )
        goto Exit;

      /* store the offset of instructions */
      ins_pos = loader->ins_pos;

      /* all data we need are read */
      face->forget_glyph_frame( loader );
      opened_frame = 0;

#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT

      if ( face->doblend )
      {
        FT_Int       i, limit;
        FT_SubGlyph  subglyph;
        FT_Memory    memory = face->root.memory;


        /* this provides additional offsets */
        /* for each component's translation */

        if ( (error = TT_Vary_Get_Glyph_Deltas(
                        face,
                        glyph_index,
                        &deltas,
                        gloader->current.num_subglyphs + 4 )) != 0 )
          goto Exit;

        subglyph = gloader->current.subglyphs + gloader->base.num_subglyphs;
        limit    = gloader->current.num_subglyphs;

        for ( i = 0; i < limit; ++i, ++subglyph )
        {
          if ( subglyph->flags & ARGS_ARE_XY_VALUES )
          {
            subglyph->arg1 += deltas[i].x;
            subglyph->arg2 += deltas[i].y;
          }
        }

        loader->pp1.x += deltas[i + 0].x; loader->pp1.y += deltas[i + 0].y;
        loader->pp2.x += deltas[i + 1].x; loader->pp2.y += deltas[i + 1].y;
        loader->pp3.x += deltas[i + 2].x; loader->pp3.y += deltas[i + 2].y;
        loader->pp4.x += deltas[i + 3].x; loader->pp4.y += deltas[i + 3].y;

        FT_FREE( deltas );
      }

#endif /* TT_CONFIG_OPTION_GX_VAR_SUPPORT */

      if ( ( loader->load_flags & FT_LOAD_NO_SCALE ) == 0 )
      {
        loader->pp1.x = FT_MulFix( loader->pp1.x, x_scale );
        loader->pp2.x = FT_MulFix( loader->pp2.x, x_scale );
        loader->pp3.y = FT_MulFix( loader->pp3.y, y_scale );
        loader->pp4.y = FT_MulFix( loader->pp4.y, y_scale );
      }

      /* if the flag FT_LOAD_NO_RECURSE is set, we return the subglyph */
      /* `as is' in the glyph slot (the client application will be     */
      /* responsible for interpreting these data)...                   */
      /*                                                               */
      if ( loader->load_flags & FT_LOAD_NO_RECURSE )
      {
        FT_GlyphLoader_Add( gloader );
        loader->glyph->format = FT_GLYPH_FORMAT_COMPOSITE;

        goto Exit;
      }

      /*********************************************************************/
      /*********************************************************************/
      /*********************************************************************/

      {
        FT_UInt      n, num_base_points;
        FT_SubGlyph  subglyph       = 0;

        FT_UInt      num_points     = start_point;
        FT_UInt      num_subglyphs  = gloader->current.num_subglyphs;
        FT_UInt      num_base_subgs = gloader->base.num_subglyphs;

        FT_Stream    old_stream     = loader->stream;


        FT_GlyphLoader_Add( gloader );

        /* read each subglyph independently */
        for ( n = 0; n < num_subglyphs; n++ )
        {
          FT_Vector  pp[4];


          /* Each time we call load_truetype_glyph in this loop, the   */
          /* value of `gloader.base.subglyphs' can change due to table */
          /* reallocations.  We thus need to recompute the subglyph    */
          /* pointer on each iteration.                                */
          subglyph = gloader->base.subglyphs + num_base_subgs + n;

          pp[0] = loader->pp1;
          pp[1] = loader->pp2;
          pp[2] = loader->pp3;
          pp[3] = loader->pp4;

          num_base_points = gloader->base.outline.n_points;

          error = load_truetype_glyph( loader, subglyph->index,
                                       recurse_count + 1 );
          if ( error )
            goto Exit;

          /* restore subglyph pointer */
          subglyph = gloader->base.subglyphs + num_base_subgs + n;

          if ( !( subglyph->flags & USE_MY_METRICS ) )
          {
            loader->pp1 = pp[0];
            loader->pp2 = pp[1];
            loader->pp3 = pp[2];
            loader->pp4 = pp[3];
          }

          num_points = gloader->base.outline.n_points;

          if ( num_points == num_base_points )
            continue;

          /* gloader->base.outline consists of three part:                  */
          /* 0 -(1)-> start_point -(2)-> num_base_points -(3)-> n_points.   */
          /*                                                                */
          /* (1): exist from the beginning                                  */
          /* (2): components that have been loaded so far                   */
          /* (3): the newly loaded component                                */
          TT_Process_Composite_Component( loader, subglyph, start_point,
                                          num_base_points );
        }

        loader->stream = old_stream;

        /* process the glyph */
        loader->ins_pos = ins_pos;
        if ( IS_HINTED( loader->load_flags ) &&

#ifdef TT_USE_BYTECODE_INTERPRETER

             subglyph->flags & WE_HAVE_INSTR &&

#endif

             num_points > start_point )
          TT_Process_Composite_Glyph( loader, start_point, start_contour );

      }
    }
    else
    {
      /* invalid composite count ( negative but not -1 ) */
      error = TT_Err_Invalid_Outline;
      goto Exit;
    }

    /***********************************************************************/
    /***********************************************************************/
    /***********************************************************************/

  Exit:

    if ( opened_frame )
      face->forget_glyph_frame( loader );

#ifdef FT_CONFIG_OPTION_INCREMENTAL

    if ( glyph_data_loaded )
      face->root.internal->incremental_interface->funcs->free_glyph_data(
        face->root.internal->incremental_interface->object,
        &glyph_data );

#endif

    return error;
  }


  static FT_Error
  compute_glyph_metrics( TT_Loader   loader,
                         FT_UInt     glyph_index )
  {
    FT_BBox       bbox;
    TT_Face       face = (TT_Face)loader->face;
    FT_Fixed      y_scale;
    TT_GlyphSlot  glyph = loader->glyph;
    TT_Size       size = (TT_Size)loader->size;


    y_scale = 0x10000L;
    if ( ( loader->load_flags & FT_LOAD_NO_SCALE ) == 0 )
      y_scale = size->root.metrics.y_scale;

    if ( glyph->format != FT_GLYPH_FORMAT_COMPOSITE )
      FT_Outline_Get_CBox( &glyph->outline, &bbox );
    else
      bbox = loader->bbox;

    /* get the device-independent horizontal advance.  It is scaled later */
    /* by the base layer.                                                 */
    {
      FT_Pos  advance = loader->linear;


      /* the flag FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH was introduced to */
      /* correctly support DynaLab fonts, which have an incorrect       */
      /* `advance_Width_Max' field!  It is used, to my knowledge,       */
      /* exclusively in the X-TrueType font server.                     */
      /*                                                                */
      if ( face->postscript.isFixedPitch                                     &&
           ( loader->load_flags & FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH ) == 0 )
        advance = face->horizontal.advance_Width_Max;

      /* we need to return the advance in font units in linearHoriAdvance, */
      /* it will be scaled later by the base layer.                        */
      glyph->linearHoriAdvance = advance;
    }

    glyph->metrics.horiBearingX = bbox.xMin;
    glyph->metrics.horiBearingY = bbox.yMax;
    glyph->metrics.horiAdvance  = loader->pp2.x - loader->pp1.x;

    /* Now take care of vertical metrics.  In the case where there is    */
    /* no vertical information within the font (relatively common), make */
    /* up some metrics by `hand'...                                      */

    {
      FT_Pos  top;      /* scaled vertical top side bearing  */
      FT_Pos  advance;  /* scaled vertical advance height    */


      /* Get the unscaled top bearing and advance height. */
      if ( face->vertical_info &&
           face->vertical.number_Of_VMetrics > 0 )
      {
        top = (FT_Short)FT_DivFix( loader->pp3.y - bbox.yMax,
                                   y_scale );

        if ( loader->pp3.y <= loader->pp4.y )
          advance = 0;
        else
          advance = (FT_UShort)FT_DivFix( loader->pp3.y - loader->pp4.y,