ttgload.c

奇趣公司比较新的qt/emd版本

  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    TT_Process_Composite_Component                                     */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Once a composite component has been loaded, it needs to be         */
  /*    processed.  Usually, this means transforming and translating.      */
  /*                                                                       */
  static FT_Error
  TT_Process_Composite_Component( TT_Loader    loader,
                                  FT_SubGlyph  subglyph,
                                  FT_UInt      start_point,
                                  FT_UInt      num_base_points )
  {
    FT_GlyphLoader  gloader    = loader->gloader;
    FT_Vector*      base_vec   = gloader->base.outline.points;
    FT_UInt         num_points = gloader->base.outline.n_points;
    FT_Bool         have_scale;
    FT_Pos          x, y;


    have_scale = FT_BOOL( subglyph->flags & ( WE_HAVE_A_SCALE     |
                                              WE_HAVE_AN_XY_SCALE |
                                              WE_HAVE_A_2X2       ) );

    /* perform the transform required for this subglyph */
    if ( have_scale )
    {
      FT_UInt  i;


      for ( i = num_base_points; i < num_points; i++ )
        FT_Vector_Transform( base_vec + i, &subglyph->transform );
    }

    /* get offset */
    if ( !( subglyph->flags & ARGS_ARE_XY_VALUES ) )
    {
      FT_UInt     k = subglyph->arg1;
      FT_UInt     l = subglyph->arg2;
      FT_Vector*  p1;
      FT_Vector*  p2;


      /* match l-th point of the newly loaded component to the k-th point */
      /* of the previously loaded components.                             */

      /* change to the point numbers used by our outline */
      k += start_point;
      l += num_base_points;
      if ( k >= num_base_points ||
           l >= num_points      )
        return TT_Err_Invalid_Composite;

      p1 = gloader->base.outline.points + k;
      p2 = gloader->base.outline.points + l;

      x = p1->x - p2->x;
      y = p1->y - p2->y;
    }
    else
    {
      x = subglyph->arg1;
      y = subglyph->arg2;

      if ( !x && !y )
        return TT_Err_Ok;

  /* Use a default value dependent on                                     */
  /* TT_CONFIG_OPTION_COMPONENT_OFFSET_SCALED.  This is useful for old TT */
  /* fonts which don't set the xxx_COMPONENT_OFFSET bit.                  */

      if ( have_scale &&
#ifdef TT_CONFIG_OPTION_COMPONENT_OFFSET_SCALED
           !( subglyph->flags & UNSCALED_COMPONENT_OFFSET ) )
#else
            ( subglyph->flags & SCALED_COMPONENT_OFFSET ) )
#endif
      {

#if 0

  /*************************************************************************/
  /*                                                                       */
  /* This algorithm is what Apple documents.  But it doesn't work.         */
  /*                                                                       */
        int  a = subglyph->transform.xx > 0 ?  subglyph->transform.xx
                                            : -subglyph->transform.xx;
        int  b = subglyph->transform.yx > 0 ?  subglyph->transform.yx
                                            : -subglyph->transform.yx;
        int  c = subglyph->transform.xy > 0 ?  subglyph->transform.xy
                                            : -subglyph->transform.xy;
        int  d = subglyph->transform.yy > 0 ? subglyph->transform.yy
                                            : -subglyph->transform.yy;
        int  m = a > b ? a : b;
        int  n = c > d ? c : d;


        if ( a - b <= 33 && a - b >= -33 )
          m *= 2;
        if ( c - d <= 33 && c - d >= -33 )
          n *= 2;
        x = FT_MulFix( x, m );
        y = FT_MulFix( y, n );

#else /* 0 */

  /*************************************************************************/
  /*                                                                       */
  /* This algorithm is a guess and works much better than the above.       */
  /*                                                                       */
        FT_Fixed  mac_xscale = FT_SqrtFixed(
                                 FT_MulFix( subglyph->transform.xx,
                                            subglyph->transform.xx ) +
                                 FT_MulFix( subglyph->transform.xy,
                                            subglyph->transform.xy ) );
        FT_Fixed  mac_yscale = FT_SqrtFixed(
                                 FT_MulFix( subglyph->transform.yy,
                                            subglyph->transform.yy ) +
                                 FT_MulFix( subglyph->transform.yx,
                                            subglyph->transform.yx ) );


        x = FT_MulFix( x, mac_xscale );
        y = FT_MulFix( y, mac_yscale );

#endif /* 0 */

      }

      if ( !( loader->load_flags & FT_LOAD_NO_SCALE ) )
      {
        FT_Fixed  x_scale = ((TT_Size)loader->size)->metrics.x_scale;
        FT_Fixed  y_scale = ((TT_Size)loader->size)->metrics.y_scale;


        x = FT_MulFix( x, x_scale );
        y = FT_MulFix( y, y_scale );

        if ( subglyph->flags & ROUND_XY_TO_GRID )
        {
          x = FT_PIX_ROUND( x );
          y = FT_PIX_ROUND( y );
        }
      }
    }

    if ( x || y )
      translate_array( num_points - num_base_points,
                       base_vec + num_base_points,
                       x, y );

    return TT_Err_Ok;
  }


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    TT_Process_Composite_Glyph                                         */
  /*                                                                       */
  /* <Description>                                                         */
  /*    This is slightly different from TT_Process_Simple_Glyph, in that   */
  /*    its sole purpose is to hint the glyph.  Thus this function is      */
  /*    only available when bytecode interpreter is enabled.               */
  /*                                                                       */
  static FT_Error
  TT_Process_Composite_Glyph( TT_Loader  loader,
                              FT_UInt    start_point,
                              FT_UInt    start_contour )
  {
    FT_Error     error;
    FT_Outline*  outline;
    FT_UInt      i;


    outline = &loader->gloader->base.outline;

    /* make room for phantom points */
    error = FT_GLYPHLOADER_CHECK_POINTS( loader->gloader,
                                         outline->n_points + 4,
                                         0 );
    if ( error )
      return error;

    outline->points[outline->n_points    ] = loader->pp1;
    outline->points[outline->n_points + 1] = loader->pp2;
    outline->points[outline->n_points + 2] = loader->pp3;
    outline->points[outline->n_points + 3] = loader->pp4;

    outline->tags[outline->n_points    ] = 0;
    outline->tags[outline->n_points + 1] = 0;
    outline->tags[outline->n_points + 2] = 0;
    outline->tags[outline->n_points + 3] = 0;

#ifdef TT_USE_BYTECODE_INTERPRETER

    {
      FT_Stream  stream = loader->stream;
      FT_UShort  n_ins;


      /* TT_Load_Composite_Glyph only gives us the offset of instructions */
      /* so we read them here                                             */
      if ( FT_STREAM_SEEK( loader->ins_pos ) ||
           FT_READ_USHORT( n_ins )           )
        return error;

      FT_TRACE5(( "  Instructions size = %d\n", n_ins ));

      /* check it */
      if ( n_ins > ((TT_Face)loader->face)->max_profile.maxSizeOfInstructions )
      {
        FT_TRACE0(( "Too many instructions (%d)\n", n_ins ));

        return TT_Err_Too_Many_Hints;
      }
      else if ( n_ins == 0 )
        return TT_Err_Ok;

      if ( FT_STREAM_READ( loader->exec->glyphIns, n_ins ) )
        return error;

      loader->glyph->control_data = loader->exec->glyphIns;
      loader->glyph->control_len  = n_ins;
    }

#endif

    tt_prepare_zone( &loader->zone, &loader->gloader->base,
                     start_point, start_contour );

    /* Some points are likely touched during execution of  */
    /* instructions on components.  So let's untouch them. */
    for ( i = start_point; i < loader->zone.n_points; i++ )
      loader->zone.tags[i] &= ~( FT_CURVE_TAG_TOUCH_X |
                                 FT_CURVE_TAG_TOUCH_Y );

    loader->zone.n_points += 4;

    return TT_Hint_Glyph( loader, 1 );
  }


  /* Calculate the four phantom points.                     */
  /* The first two stand for horizontal origin and advance. */
  /* The last two stand for vertical origin and advance.    */
#define TT_LOADER_SET_PP( loader )                                          \
          do {                                                              \
            (loader)->pp1.x = (loader)->bbox.xMin - (loader)->left_bearing; \
            (loader)->pp1.y = 0;                                            \
            (loader)->pp2.x = (loader)->pp1.x + (loader)->advance;          \
            (loader)->pp2.y = 0;                                            \
            (loader)->pp3.x = 0;                                            \
            (loader)->pp3.y = (loader)->top_bearing + (loader)->bbox.yMax;  \
            (loader)->pp4.x = 0;                                            \
            (loader)->pp4.y = (loader)->pp3.y - (loader)->vadvance;         \
          } while ( 0 )


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    load_truetype_glyph                                                */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Loads a given truetype glyph.  Handles composites and uses a       */
  /*    TT_Loader object.                                                  */
  /*                                                                       */
  static FT_Error
  load_truetype_glyph( TT_Loader  loader,
                       FT_UInt    glyph_index,
                       FT_UInt    recurse_count )
  {
    FT_Error        error;
    FT_Fixed        x_scale, y_scale;
    FT_ULong        offset;
    TT_Face         face         = (TT_Face)loader->face;
    FT_GlyphLoader  gloader      = loader->gloader;
    FT_Bool         opened_frame = 0;

#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
    FT_Vector*      deltas       = NULL;
#endif

#ifdef FT_CONFIG_OPTION_INCREMENTAL
    FT_StreamRec    inc_stream;
    FT_Data         glyph_data;
    FT_Bool         glyph_data_loaded = 0;
#endif


    if ( recurse_count > face->max_profile.maxComponentDepth )
    {
      error = TT_Err_Invalid_Composite;
      goto Exit;
    }

    /* check glyph index */
    if ( glyph_index >= (FT_UInt)face->root.num_glyphs )
    {
      error = TT_Err_Invalid_Glyph_Index;
      goto Exit;
    }

    loader->glyph_index = glyph_index;

    if ( ( loader->load_flags & FT_LOAD_NO_SCALE ) == 0 )
    {
      x_scale = ((TT_Size)loader->size)->metrics.x_scale;
      y_scale = ((TT_Size)loader->size)->metrics.y_scale;
    }
    else
    {
      x_scale = 0x10000L;
      y_scale = 0x10000L;
    }

    /* get metrics, horizontal and vertical */
    {
      FT_Short   left_bearing = 0, top_bearing = 0;
      FT_UShort  advance_width = 0, advance_height = 0;


      Get_HMetrics( face, glyph_index,
                    (FT_Bool)!( loader->load_flags &
                                FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH ),
                    &left_bearing,
                    &advance_width );
      Get_VMetrics( face, glyph_index,
                    (FT_Bool)!( loader->load_flags &
                                FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH ),
                    &top_bearing,
                    &advance_height );

#ifdef FT_CONFIG_OPTION_INCREMENTAL

      /* If this is an incrementally loaded font see if there are */
      /* overriding metrics for this glyph.                       */
      if ( face->root.internal->incremental_interface &&
           face->root.internal->incremental_interface->funcs->get_glyph_metrics )
      {
        FT_Incremental_MetricsRec  metrics;


        metrics.bearing_x = left_bearing;
        metrics.bearing_y = 0;
        metrics.advance = advance_width;
        error = face->root.internal->incremental_interface->funcs->get_glyph_metrics(
                  face->root.internal->incremental_interface->object,
                  glyph_index, FALSE, &metrics );
        if ( error )
          goto Exit;
        left_bearing  = (FT_Short)metrics.bearing_x;
        advance_width = (FT_UShort)metrics.advance;

#if 0

        /* GWW: Do I do the same for vertical metrics? */
        metrics.bearing_x = 0;
        metrics.bearing_y = top_bearing;
        metrics.advance = advance_height;
        error = face->root.internal->incremental_interface->funcs->get_glyph_metrics(
                  face->root.internal->incremental_interface->object,
                  glyph_index, TRUE, &metrics );
        if ( error )
          goto Exit;
        top_bearing  = (FT_Short)metrics.bearing_y;
        advance_height = (FT_UShort)metrics.advance;

#endif /* 0 */

      }

#endif /* FT_CONFIG_OPTION_INCREMENTAL */

      loader->left_bearing = left_bearing;
      loader->advance      = advance_width;
      loader->top_bearing  = top_bearing;
      loader->vadvance     = advance_height;

      if ( !loader->linear_def )
      {
        loader->linear_def = 1;