C++ TT_Face类代码示例

  tt_face_load_loca( TT_Face    face,
                     FT_Stream  stream )
  {
    FT_Error  error;
    FT_ULong  table_len;


    /* we need the size of the `glyf' table for malformed `loca' tables */
    error = face->goto_table( face, TTAG_glyf, stream, &face->glyf_len );
    if ( error )
      goto Exit;

    FT_TRACE2(( "Locations " ));
    error = face->goto_table( face, TTAG_loca, stream, &table_len );
    if ( error )
    {
      error = TT_Err_Locations_Missing;
      goto Exit;
    }

    if ( face->header.Index_To_Loc_Format != 0 )
    {
      if ( table_len >= 0x40000L )
      {
        FT_TRACE2(( "table too large!\n" ));
        error = TT_Err_Invalid_Table;
        goto Exit;
      }
      face->num_locations = (FT_UInt)( table_len >> 2 );
    }
    else
    {
      if ( table_len >= 0x20000L )

  tt_face_load_loca( TT_Face    face,
                     FT_Stream  stream )
  {
    FT_Error  error;
    FT_ULong  table_len;
    FT_Int    shift;


    /* we need the size of the `glyf' table for malformed `loca' tables */
    error = face->goto_table( face, TTAG_glyf, stream, &face->glyf_len );

    /* it is possible that a font doesn't have a glyf table at all */
    /* or its size is zero                                         */
    if ( FT_ERR_EQ( error, Table_Missing ) )
    {
      face->glyf_len    = 0;
      face->glyf_offset = 0;
    }
    else if ( error )
      goto Exit;
    else
    {
#ifdef FT_CONFIG_OPTION_INCREMENTAL
      if ( face->root.internal->incremental_interface )
        face->glyf_offset = 0;
      else
#endif
        face->glyf_offset = FT_STREAM_POS();
    }

    FT_TRACE2(( "Locations " ));
    error = face->goto_table( face, TTAG_loca, stream, &table_len );
    if ( error )
    {
      error = FT_THROW( Locations_Missing );
      goto Exit;
    }

    if ( face->header.Index_To_Loc_Format != 0 )
    {
      shift = 2;

      if ( table_len >= 0x40000L )
      {
        FT_TRACE2(( "table too large\n" ));
        table_len = 0x3FFFFL;
      }
      face->num_locations = table_len >> shift;
    }

  static FT_Error
  load_post_names( TT_Face  face )
  {
    FT_Stream  stream;
    FT_Error   error;
    FT_Fixed   format;


    /* get a stream for the face's resource */
    stream = face->root.stream;

    /* seek to the beginning of the PS names table */
    error = face->goto_table( face, TTAG_post, stream, 0 );
    if ( error )
      goto Exit;

    format = face->postscript.FormatType;

    /* go to beginning of subtable */
    if ( FT_STREAM_SKIP( 32 ) )
      goto Exit;

    /* now read postscript table */
    if ( format == 0x00020000L )
      error = load_format_20( face, stream );
    else if ( format == 0x00028000L )
      error = load_format_25( face, stream );
    else
      error = SFNT_Err_Invalid_File_Format;

    face->postscript_names.loaded = 1;

  Exit:
    return error;
  }

  tt_face_load_hmtx( TT_Face    face,
                     FT_Stream  stream,
                     FT_Bool    vertical )
  {
    FT_Error   error;
    FT_ULong   tag, table_size;
    FT_ULong*  ptable_offset;
    FT_ULong*  ptable_size;


    if ( vertical )
    {
      tag           = TTAG_vmtx;
      ptable_offset = &face->vert_metrics_offset;
      ptable_size   = &face->vert_metrics_size;
    }
    else
    {
      tag           = TTAG_hmtx;
      ptable_offset = &face->horz_metrics_offset;
      ptable_size   = &face->horz_metrics_size;
    }

    error = face->goto_table( face, tag, stream, &table_size );
    if ( error )
      goto Fail;

    *ptable_size   = table_size;
    *ptable_offset = FT_STREAM_POS();

  Fail:
    return error;
  }

  tt_size_run_prep( TT_Size  size )
  {
    TT_Face         face = (TT_Face)size->root.face;
    TT_ExecContext  exec;
    FT_Error        error;


    /* debugging instances have their own context */
    if ( size->debug )
      exec = size->context;
    else
      exec = ( (TT_Driver)FT_FACE_DRIVER( face ) )->context;

    if ( !exec )
      return TT_Err_Could_Not_Find_Context;

    TT_Load_Context( exec, face, size );

    exec->callTop = 0;
    exec->top     = 0;

    exec->instruction_trap = FALSE;

    TT_Set_CodeRange( exec,
                      tt_coderange_cvt,
                      face->cvt_program,
                      face->cvt_program_size );

    TT_Clear_CodeRange( exec, tt_coderange_glyph );

    if ( face->cvt_program_size > 0 )
    {
      error = TT_Goto_CodeRange( exec, tt_coderange_cvt, 0 );

      if ( !error && !size->debug )
        error = face->interpreter( exec );
    }
    else
      error = TT_Err_Ok;

    /* save as default graphics state */
    size->GS = exec->GS;

    TT_Save_Context( exec, size );

    return error;
  }

  tt_face_load_gasp( TT_Face    face,
                     FT_Stream  stream )
  {
    FT_Error   error;
    FT_Memory  memory = stream->memory;

    FT_UInt        j,num_ranges;
    TT_GaspRange   gaspranges;


    /* the gasp table is optional */
    error = face->goto_table( face, TTAG_gasp, stream, 0 );
    if ( error )
      goto Exit;

    if ( FT_FRAME_ENTER( 4L ) )
      goto Exit;

    face->gasp.version   = FT_GET_USHORT();
    face->gasp.numRanges = FT_GET_USHORT();

    FT_FRAME_EXIT();

    /* only support versions 0 and 1 of the table */
    if ( face->gasp.version >= 2 )
    {
      face->gasp.numRanges = 0;
      error = SFNT_Err_Invalid_Table;
      goto Exit;
    }

    num_ranges = face->gasp.numRanges;
    FT_TRACE3(( "numRanges: %u\n", num_ranges ));

    if ( FT_QNEW_ARRAY( gaspranges, num_ranges ) ||
         FT_FRAME_ENTER( num_ranges * 4L )      )
      goto Exit;

    face->gasp.gaspRanges = gaspranges;

    for ( j = 0; j < num_ranges; j++ )
    {
      gaspranges[j].maxPPEM  = FT_GET_USHORT();
      gaspranges[j].gaspFlag = FT_GET_USHORT();

      FT_TRACE3(( "gaspRange %d: rangeMaxPPEM %5d, rangeGaspBehavior 0x%x\n",
                  j,
                  gaspranges[j].maxPPEM,
                  gaspranges[j].gaspFlag ));
    }

    FT_FRAME_EXIT();

  Exit:
    return error;
  }

  static FT_Error
  tt_face_load_generic_header( TT_Face    face,
                               FT_Stream  stream,
                               FT_ULong   tag )
  {
    FT_Error    error;
    TT_Header*  header;

    static const FT_Frame_Field  header_fields[] =
    {
#undef  FT_STRUCTURE
#define FT_STRUCTURE  TT_Header

      FT_FRAME_START( 54 ),
        FT_FRAME_ULONG ( Table_Version ),
        FT_FRAME_ULONG ( Font_Revision ),
        FT_FRAME_LONG  ( CheckSum_Adjust ),
        FT_FRAME_LONG  ( Magic_Number ),
        FT_FRAME_USHORT( Flags ),
        FT_FRAME_USHORT( Units_Per_EM ),
        FT_FRAME_LONG  ( Created[0] ),
        FT_FRAME_LONG  ( Created[1] ),
        FT_FRAME_LONG  ( Modified[0] ),
        FT_FRAME_LONG  ( Modified[1] ),
        FT_FRAME_SHORT ( xMin ),
        FT_FRAME_SHORT ( yMin ),
        FT_FRAME_SHORT ( xMax ),
        FT_FRAME_SHORT ( yMax ),
        FT_FRAME_USHORT( Mac_Style ),
        FT_FRAME_USHORT( Lowest_Rec_PPEM ),
        FT_FRAME_SHORT ( Font_Direction ),
        FT_FRAME_SHORT ( Index_To_Loc_Format ),
        FT_FRAME_SHORT ( Glyph_Data_Format ),
      FT_FRAME_END
    };


    error = face->goto_table( face, tag, stream, 0 );
    if ( error )
      goto Exit;

    header = &face->header;

    if ( FT_STREAM_READ_FIELDS( header_fields, header ) )
      goto Exit;

    FT_TRACE3(( "Units per EM: %4u\n", header->Units_Per_EM ));
    FT_TRACE3(( "IndexToLoc:   %4d\n", header->Index_To_Loc_Format ));

  Exit:
    return error;
  }

  tt_face_load_loca( TT_Face    face,
                     FT_Stream  stream )
  {
    FT_Error  error;
    FT_ULong  table_len;
    FT_Int    shift;


    /* we need the size of the `glyf' table for malformed `loca' tables */
    error = face->goto_table( face, TTAG_glyf, stream, &face->glyf_len );

    /* it is possible that a font doesn't have a glyf table at all */
    /* or its size is zero                                         */
    if ( FT_ERR_EQ( error, Table_Missing ) )
      face->glyf_len = 0;
    else if ( error )
      goto Exit;

    FT_TRACE2(( "Locations " ));
    error = face->goto_table( face, TTAG_loca, stream, &table_len );
    if ( error )
    {
      error = FT_THROW( Locations_Missing );
      goto Exit;
    }

    if ( face->header.Index_To_Loc_Format != 0 )
    {
      shift = 2;

      if ( table_len >= 0x40000L )
      {
        FT_TRACE2(( "table too large\n" ));
        error = FT_THROW( Invalid_Table );
        goto Exit;
      }
      face->num_locations = table_len >> shift;
    }

  tt_face_load_hmtx( TT_Face    face,
                     FT_Stream  stream,
                     FT_Bool    vertical )
  {
    FT_Error   error;
    FT_ULong   table_size;
    FT_Byte**  ptable;
    FT_ULong*  ptable_size;
    
    
    if ( vertical )
    {
      error = face->goto_table( face, TTAG_vmtx, stream, &table_size );
      if ( error )
        goto Fail;

      ptable      = &face->vert_metrics;
      ptable_size = &face->vert_metrics_size;
    }
    else
    {
      error = face->goto_table( face, TTAG_hmtx, stream, &table_size );
      if ( error )
        goto Fail;

      ptable      = &face->horz_metrics;
      ptable_size = &face->horz_metrics_size;
    }
    
    if ( FT_FRAME_EXTRACT( table_size, *ptable ) )
      goto Fail;
      
    *ptable_size = table_size;

  Fail:
    return error;
  }

  tt_face_load_cmap( TT_Face    face,
                     FT_Stream  stream )
  {
    FT_Error  error;


    error = face->goto_table( face, TTAG_cmap, stream, &face->cmap_size );
    if ( error )
      goto Exit;

    if ( FT_FRAME_EXTRACT( face->cmap_size, face->cmap_table ) )
      face->cmap_size = 0;

  Exit:
    return error;
  }

  FT_LOCAL_DEF
  FT_Error  TT_Load_Locations( TT_Face    face,
                               FT_Stream  stream )
  {
    FT_Error   error;
    FT_Memory  memory = stream->memory;
    FT_Short   LongOffsets;
    FT_ULong   table_len;


    FT_TRACE2(( "Locations " ));
    LongOffsets = face->header.Index_To_Loc_Format;

    error = face->goto_table( face, TTAG_loca, stream, &table_len );
    if ( error )
    {
      error = TT_Err_Locations_Missing;
      goto Exit;
    }

    if ( LongOffsets != 0 )
    {
      face->num_locations = (FT_UShort)( table_len >> 2 );

      FT_TRACE2(( "(32bit offsets): %12d ", face->num_locations ));

      if ( ALLOC_ARRAY( face->glyph_locations,
                        face->num_locations,
                        FT_Long ) )
        goto Exit;

      if ( ACCESS_Frame( face->num_locations * 4L ) )
        goto Exit;

      {
        FT_Long*  loc   = face->glyph_locations;
        FT_Long*  limit = loc + face->num_locations;


        for ( ; loc < limit; loc++ )
          *loc = GET_Long();
      }

      FORGET_Frame();
    }

  static
  FT_Error  Load_Post_Names( TT_Face  face )
  {
    FT_Stream  stream;
    FT_Error   error;
    FT_Fixed   format;


    /* get a stream for the face's resource */
    stream = face->root.stream;

    /* seek to the beginning of the PS names table */
    error = face->goto_table( face, TTAG_post, stream, 0 );
    if ( error )
      goto Exit;

    format = face->postscript.FormatType;

    /* go to beginning of subtable */
    if ( FILE_Skip( 32 ) )
      goto Exit;

    /* now read postscript table */
    switch ( format )
    {
    case 0x00020000L:
      error = Load_Format_20( face, stream );
      break;

    case 0x00028000L:
      error = Load_Format_25( face, stream );
      break;

    default:
      error = TT_Err_Invalid_File_Format;
    }

    face->postscript_names.loaded = 1;

  Exit:
    return error;
  }

  tt_face_load_pclt( TT_Face    face,
                     FT_Stream  stream )
  {
    static const FT_Frame_Field  pclt_fields[] =
    {
#undef  FT_STRUCTURE
#define FT_STRUCTURE  TT_PCLT

      FT_FRAME_START( 54 ),
        FT_FRAME_ULONG ( Version ),
        FT_FRAME_ULONG ( FontNumber ),
        FT_FRAME_USHORT( Pitch ),
        FT_FRAME_USHORT( xHeight ),
        FT_FRAME_USHORT( Style ),
        FT_FRAME_USHORT( TypeFamily ),
        FT_FRAME_USHORT( CapHeight ),
        FT_FRAME_BYTES ( TypeFace, 16 ),
        FT_FRAME_BYTES ( CharacterComplement, 8 ),
        FT_FRAME_BYTES ( FileName, 6 ),
        FT_FRAME_CHAR  ( StrokeWeight ),
        FT_FRAME_CHAR  ( WidthType ),
        FT_FRAME_BYTE  ( SerifStyle ),
        FT_FRAME_BYTE  ( Reserved ),
      FT_FRAME_END
    };

    FT_Error  error;
    TT_PCLT*  pclt = &face->pclt;


    /* optional table */
    error = face->goto_table( face, TTAG_PCLT, stream, 0 );
    if ( error )
      goto Exit;

    if ( FT_STREAM_READ_FIELDS( pclt_fields, pclt ) )
      goto Exit;

  Exit:
    return error;
  }

  tt_face_load_post( TT_Face    face,
                     FT_Stream  stream )
  {
    FT_Error        error;
    TT_Postscript*  post = &face->postscript;

    static const FT_Frame_Field  post_fields[] =
    {
#undef  FT_STRUCTURE
#define FT_STRUCTURE  TT_Postscript

      FT_FRAME_START( 32 ),
        FT_FRAME_ULONG( FormatType ),
        FT_FRAME_ULONG( italicAngle ),
        FT_FRAME_SHORT( underlinePosition ),
        FT_FRAME_SHORT( underlineThickness ),
        FT_FRAME_ULONG( isFixedPitch ),
        FT_FRAME_ULONG( minMemType42 ),
        FT_FRAME_ULONG( maxMemType42 ),
        FT_FRAME_ULONG( minMemType1 ),
        FT_FRAME_ULONG( maxMemType1 ),
      FT_FRAME_END
    };


    error = face->goto_table( face, TTAG_post, stream, 0 );
    if ( error )
      return error;

    if ( FT_STREAM_READ_FIELDS( post_fields, post ) )
      return error;

    /* we don't load the glyph names, we do that in another */
    /* module (ttpost).                                     */

    FT_TRACE3(( "FormatType:   0x%x\n", post->FormatType ));
    FT_TRACE3(( "isFixedPitch:   %s\n", post->isFixedPitch
                                        ? "  yes" : "   no" ));

    return SFNT_Err_Ok;
  }

static FT_ULong
tt_get_sfnt_checksum( TT_Face    face,
                      FT_UShort  i )
{
#if 0 /* if we believe the written value, use following part. */
    if ( face->dir_tables[i].CheckSum )
        return face->dir_tables[i].CheckSum;
#endif

    if ( !face->goto_table )
        return 0;

    if ( face->goto_table( face,
                           face->dir_tables[i].Tag,
                           face->root.stream,
                           NULL ) )
        return 0;

    return (FT_ULong)tt_synth_sfnt_checksum( face->root.stream,
            face->dir_tables[i].Length );
}