ttgload.c

来自「一个类似windows」· C语言 代码 · 共 1,925 行 · 第 1/5 页

    /* the following line sets the `error' variable through macros! */
    if ( FT_STREAM_SEEK( offset ) || FT_FRAME_ENTER( byte_count ) )
      return error;

    return TT_Err_Ok;
  }


  FT_CALLBACK_DEF( void )
  TT_Forget_Glyph_Frame( TT_Loader  loader )
  {
    FT_Stream  stream = loader->stream;


    FT_FRAME_EXIT();
  }


  FT_CALLBACK_DEF( FT_Error )
  TT_Load_Glyph_Header( TT_Loader  loader )
  {
    FT_Stream  stream   = loader->stream;
    FT_Int     byte_len = loader->byte_len - 10;


    if ( byte_len < 0 )
      return TT_Err_Invalid_Outline;

    loader->n_contours = FT_GET_SHORT();

    loader->bbox.xMin = FT_GET_SHORT();
    loader->bbox.yMin = FT_GET_SHORT();
    loader->bbox.xMax = FT_GET_SHORT();
    loader->bbox.yMax = FT_GET_SHORT();

    FT_TRACE5(( "  # of contours: %d\n", loader->n_contours ));
    FT_TRACE5(( "  xMin: %4d  xMax: %4d\n", loader->bbox.xMin,
                                            loader->bbox.xMax ));
    FT_TRACE5(( "  yMin: %4d  yMax: %4d\n", loader->bbox.yMin,
                                            loader->bbox.yMax ));
    loader->byte_len = byte_len;

    return TT_Err_Ok;
  }


  FT_CALLBACK_DEF( FT_Error )
  TT_Load_Simple_Glyph( TT_Loader  load )
  {
    FT_Error        error;
    FT_Stream       stream     = load->stream;
    FT_GlyphLoader  gloader    = load->gloader;
    FT_Int          n_contours = load->n_contours;
    FT_Outline*     outline;
    TT_Face         face       = (TT_Face)load->face;
    TT_GlyphSlot    slot       = (TT_GlyphSlot)load->glyph;
    FT_UShort       n_ins;
    FT_Int          n, n_points;
    FT_Int          byte_len   = load->byte_len;

    FT_Byte         *flag, *flag_limit;
    FT_Byte         c, count;
    FT_Vector       *vec, *vec_limit;
    FT_Pos          x;
    FT_Short        *cont, *cont_limit;


    /* reading the contours' endpoints & number of points */
    cont       = gloader->current.outline.contours;
    cont_limit = cont + n_contours;

    /* check space for contours array + instructions count */
    byte_len -= 2 * ( n_contours + 1 );
    if ( byte_len < 0 )
      goto Invalid_Outline;

    for ( ; cont < cont_limit; cont++ )
      cont[0] = FT_GET_USHORT();

    n_points = 0;
    if ( n_contours > 0 )
      n_points = cont[-1] + 1;

    error = FT_GlyphLoader_CheckPoints( gloader, n_points + 4, 0 );
    if ( error )
      goto Fail;

    /* we'd better check the contours table right now */
    outline = &gloader->current.outline;

    for ( cont = outline->contours + 1; cont < cont_limit; cont++ )
      if ( cont[-1] >= cont[0] )
        goto Invalid_Outline;

    /* reading the bytecode instructions */
    slot->control_len  = 0;
    slot->control_data = 0;

    n_ins = FT_GET_USHORT();

    FT_TRACE5(( "  Instructions size: %u\n", n_ins ));

    if ( n_ins > face->max_profile.maxSizeOfInstructions )
    {
      FT_TRACE0(( "TT_Load_Simple_Glyph: Too many instructions!\n" ));
      error = TT_Err_Too_Many_Hints;
      goto Fail;
    }

    byte_len -= (FT_Int)n_ins;
    if ( byte_len < 0 )
    {
      FT_TRACE0(( "TT_Load_Simple_Glyph: Instruction count mismatch!\n" ));
      error = TT_Err_Too_Many_Hints;
      goto Fail;
    }

#ifdef TT_CONFIG_OPTION_BYTECODE_INTERPRETER

    if ( ( load->load_flags                        &
         ( FT_LOAD_NO_SCALE | FT_LOAD_NO_HINTING ) ) == 0 &&
           load->instructions )
    {
      slot->control_len  = n_ins;
      slot->control_data = load->instructions;

      FT_MEM_COPY( load->instructions, stream->cursor, (FT_Long)n_ins );
    }

#endif /* TT_CONFIG_OPTION_BYTECODE_INTERPRETER */

    stream->cursor += (FT_Int)n_ins;

    /* reading the point tags */
    flag       = (FT_Byte*)outline->tags;
    flag_limit = flag + n_points;

    FT_ASSERT( flag != NULL );

    while ( flag < flag_limit )
    {
      if ( --byte_len < 0 )
        goto Invalid_Outline;

      *flag++ = c = FT_GET_BYTE();
      if ( c & 8 )
      {
        if ( --byte_len < 0 )
          goto Invalid_Outline;

        count = FT_GET_BYTE();
        if ( flag + (FT_Int)count > flag_limit )
          goto Invalid_Outline;

        for ( ; count > 0; count-- )
          *flag++ = c;
      }
    }

    /* check that there is enough room to load the coordinates */
    for ( flag = (FT_Byte*)outline->tags; flag < flag_limit; flag++ )
    {
      if ( *flag & 2 )
        byte_len -= 1;
      else if ( ( *flag & 16 ) == 0 )
        byte_len -= 2;

      if ( *flag & 4 )
        byte_len -= 1;
      else if ( ( *flag & 32 ) == 0 )
        byte_len -= 2;
    }

    if ( byte_len < 0 )
      goto Invalid_Outline;

    /* reading the X coordinates */

    vec       = outline->points;
    vec_limit = vec + n_points;
    flag      = (FT_Byte*)outline->tags;
    x         = 0;

    for ( ; vec < vec_limit; vec++, flag++ )
    {
      FT_Pos  y = 0;


      if ( *flag & 2 )
      {
        y = (FT_Pos)FT_GET_BYTE();
        if ( ( *flag & 16 ) == 0 )
          y = -y;
      }
      else if ( ( *flag & 16 ) == 0 )
        y = (FT_Pos)FT_GET_SHORT();

      x     += y;
      vec->x = x;
    }

    /* reading the Y coordinates */

    vec       = gloader->current.outline.points;
    vec_limit = vec + n_points;
    flag      = (FT_Byte*)outline->tags;
    x         = 0;

    for ( ; vec < vec_limit; vec++, flag++ )
    {
      FT_Pos  y = 0;


      if ( *flag & 4 )
      {
        y = (FT_Pos)FT_GET_BYTE();
        if ( ( *flag & 32 ) == 0 )
          y = -y;
      }
      else if ( ( *flag & 32 ) == 0 )
        y = (FT_Pos)FT_GET_SHORT();

      x     += y;
      vec->y = x;
    }

    /* clear the touch tags */
    for ( n = 0; n < n_points; n++ )
      outline->tags[n] &= FT_CURVE_TAG_ON;

    outline->n_points   = (FT_UShort)n_points;
    outline->n_contours = (FT_Short) n_contours;

    load->byte_len = byte_len;

  Fail:
    return error;

  Invalid_Outline:
    error = TT_Err_Invalid_Outline;
    goto Fail;
  }


  FT_CALLBACK_DEF( FT_Error )
  TT_Load_Composite_Glyph( TT_Loader  loader )
  {
    FT_Error        error;
    FT_Stream       stream  = loader->stream;
    FT_GlyphLoader  gloader = loader->gloader;
    FT_SubGlyph     subglyph;
    FT_UInt         num_subglyphs;
    FT_Int          byte_len = loader->byte_len;


    num_subglyphs = 0;

    do
    {
      FT_Fixed  xx, xy, yy, yx;


      /* check that we can load a new subglyph */
      error = FT_GlyphLoader_CheckSubGlyphs( gloader, num_subglyphs + 1 );
      if ( error )
        goto Fail;

      /* check space */
      byte_len -= 4;
      if ( byte_len < 0 )
        goto Invalid_Composite;

      subglyph = gloader->current.subglyphs + num_subglyphs;

      subglyph->arg1 = subglyph->arg2 = 0;

      subglyph->flags = FT_GET_USHORT();
      subglyph->index = FT_GET_USHORT();

      /* check space */
      byte_len -= 2;
      if ( subglyph->flags & ARGS_ARE_WORDS )
        byte_len -= 2;
      if ( subglyph->flags & WE_HAVE_A_SCALE )
        byte_len -= 2;
      else if ( subglyph->flags & WE_HAVE_AN_XY_SCALE )
        byte_len -= 4;
      else if ( subglyph->flags & WE_HAVE_A_2X2 )
        byte_len -= 8;

      if ( byte_len < 0 )
        goto Invalid_Composite;

      /* read arguments */
      if ( subglyph->flags & ARGS_ARE_WORDS )
      {
        subglyph->arg1 = FT_GET_SHORT();
        subglyph->arg2 = FT_GET_SHORT();
      }
      else
      {
        subglyph->arg1 = FT_GET_CHAR();
        subglyph->arg2 = FT_GET_CHAR();
      }

      /* read transform */
      xx = yy = 0x10000L;
      xy = yx = 0;

      if ( subglyph->flags & WE_HAVE_A_SCALE )
      {
        xx = (FT_Fixed)FT_GET_SHORT() << 2;
        yy = xx;
      }
      else if ( subglyph->flags & WE_HAVE_AN_XY_SCALE )
      {
        xx = (FT_Fixed)FT_GET_SHORT() << 2;
        yy = (FT_Fixed)FT_GET_SHORT() << 2;
      }
      else if ( subglyph->flags & WE_HAVE_A_2X2 )
      {
        xx = (FT_Fixed)FT_GET_SHORT() << 2;
        yx = (FT_Fixed)FT_GET_SHORT() << 2;
        xy = (FT_Fixed)FT_GET_SHORT() << 2;
        yy = (FT_Fixed)FT_GET_SHORT() << 2;
      }

      subglyph->transform.xx = xx;
      subglyph->transform.xy = xy;
      subglyph->transform.yx = yx;
      subglyph->transform.yy = yy;

      num_subglyphs++;

    } while ( subglyph->flags & MORE_COMPONENTS );

    gloader->current.num_subglyphs = num_subglyphs;

#ifdef TT_CONFIG_OPTION_BYTECODE_INTERPRETER
    {
      /* we must undo the FT_FRAME_ENTER in order to point to the */
      /* composite instructions, if we find some.               */
      /* we will process them later...                          */
      /*                                                        */
      loader->ins_pos = (FT_ULong)( FT_STREAM_POS() +
                                    stream->cursor - stream->limit );
    }
#endif

    loader->byte_len = byte_len;

  Fail:
    return error;

  Invalid_Composite:
    error = TT_Err_Invalid_Composite;
    goto Fail;
  }


  FT_LOCAL_DEF( void )
  TT_Init_Glyph_Loading( TT_Face  face )
  {
    face->access_glyph_frame   = TT_Access_Glyph_Frame;
    face->read_glyph_header    = TT_Load_Glyph_Header;
    face->read_simple_glyph    = TT_Load_Simple_Glyph;
    face->read_composite_glyph = TT_Load_Composite_Glyph;
    face->forget_glyph_frame   = TT_Forget_Glyph_Frame;
  }


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    TT_Process_Simple_Glyph                                            */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Once a simple glyph has been loaded, it needs to be processed.     */
  /*    Usually, this means scaling and hinting through bytecode           */
  /*    interpretation.                                                    */
  /*                                                                       */
  static FT_Error
  TT_Process_Simple_Glyph( TT_Loader  load,
                           FT_Bool    debug )