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kc3-lang/freetype/src/sfnt/ttload.c

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  • Author : Werner Lemberg
    Date : 2010-11-17 11:47:53
    Hash : 05012ad9
    Message : [sfnt] While tracing, output table checksums also. * src/sfnt/ttload.c (tt_face_load_font_dir): Do it.

  • src/sfnt/ttload.c
  • /***************************************************************************/
    /*                                                                         */
    /*  ttload.c                                                               */
    /*                                                                         */
    /*    Load the basic TrueType tables, i.e., tables that can be either in   */
    /*    TTF or OTF fonts (body).                                             */
    /*                                                                         */
    /*  Copyright 1996-2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009,   */
    /*            2010 by                                                      */
    /*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
    /*                                                                         */
    /*  This file is part of the FreeType project, and may only be used,       */
    /*  modified, and distributed under the terms of the FreeType project      */
    /*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
    /*  this file you indicate that you have read the license and              */
    /*  understand and accept it fully.                                        */
    /*                                                                         */
    /***************************************************************************/
    
    
    #include <ft2build.h>
    #include FT_INTERNAL_DEBUG_H
    #include FT_INTERNAL_STREAM_H
    #include FT_TRUETYPE_TAGS_H
    #include "ttload.h"
    
    #include "sferrors.h"
    
    
      /*************************************************************************/
      /*                                                                       */
      /* The macro FT_COMPONENT is used in trace mode.  It is an implicit      */
      /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log  */
      /* messages during execution.                                            */
      /*                                                                       */
    #undef  FT_COMPONENT
    #define FT_COMPONENT  trace_ttload
    
    
      /*************************************************************************/
      /*                                                                       */
      /* <Function>                                                            */
      /*    tt_face_lookup_table                                               */
      /*                                                                       */
      /* <Description>                                                         */
      /*    Looks for a TrueType table by name.                                */
      /*                                                                       */
      /* <Input>                                                               */
      /*    face :: A face object handle.                                      */
      /*                                                                       */
      /*    tag  :: The searched tag.                                          */
      /*                                                                       */
      /* <Return>                                                              */
      /*    A pointer to the table directory entry.  0 if not found.           */
      /*                                                                       */
      FT_LOCAL_DEF( TT_Table  )
      tt_face_lookup_table( TT_Face   face,
                            FT_ULong  tag  )
      {
        TT_Table  entry;
        TT_Table  limit;
    #ifdef FT_DEBUG_LEVEL_TRACE
        FT_Bool   zero_length = FALSE;
    #endif
    
    
        FT_TRACE4(( "tt_face_lookup_table: %08p, `%c%c%c%c' -- ",
                    face,
                    (FT_Char)( tag >> 24 ),
                    (FT_Char)( tag >> 16 ),
                    (FT_Char)( tag >> 8  ),
                    (FT_Char)( tag       ) ));
    
        entry = face->dir_tables;
        limit = entry + face->num_tables;
    
        for ( ; entry < limit; entry++ )
        {
          /* For compatibility with Windows, we consider    */
          /* zero-length tables the same as missing tables. */
          if ( entry->Tag == tag )
          {
            if ( entry->Length != 0 )
            {
              FT_TRACE4(( "found table.\n" ));
              return entry;
            }
    #ifdef FT_DEBUG_LEVEL_TRACE
            zero_length = TRUE;
    #endif
          }
        }
    
    #ifdef FT_DEBUG_LEVEL_TRACE
        if ( zero_length )
          FT_TRACE4(( "ignoring empty table\n" ));
        else
          FT_TRACE4(( "could not find table\n" ));
    #endif
    
        return NULL;
      }
    
    
      /*************************************************************************/
      /*                                                                       */
      /* <Function>                                                            */
      /*    tt_face_goto_table                                                 */
      /*                                                                       */
      /* <Description>                                                         */
      /*    Looks for a TrueType table by name, then seek a stream to it.      */
      /*                                                                       */
      /* <Input>                                                               */
      /*    face   :: A face object handle.                                    */
      /*                                                                       */
      /*    tag    :: The searched tag.                                        */
      /*                                                                       */
      /*    stream :: The stream to seek when the table is found.              */
      /*                                                                       */
      /* <Output>                                                              */
      /*    length :: The length of the table if found, undefined otherwise.   */
      /*                                                                       */
      /* <Return>                                                              */
      /*    FreeType error code.  0 means success.                             */
      /*                                                                       */
      FT_LOCAL_DEF( FT_Error )
      tt_face_goto_table( TT_Face    face,
                          FT_ULong   tag,
                          FT_Stream  stream,
                          FT_ULong*  length )
      {
        TT_Table  table;
        FT_Error  error;
    
    
        table = tt_face_lookup_table( face, tag );
        if ( table )
        {
          if ( length )
            *length = table->Length;
    
          if ( FT_STREAM_SEEK( table->Offset ) )
            goto Exit;
        }
        else
          error = SFNT_Err_Table_Missing;
    
      Exit:
        return error;
      }
    
    
      /* Here, we                                                         */
      /*                                                                  */
      /* - check that `num_tables' is valid (and adjust it if necessary)  */
      /*                                                                  */
      /* - look for a `head' table, check its size, and parse it to check */
      /*   whether its `magic' field is correctly set                     */
      /*                                                                  */
      /* - errors (except errors returned by stream handling)             */
      /*                                                                  */
      /*     SFNT_Err_Unknown_File_Format:                                */
      /*       no table is defined in directory, it is not sfnt-wrapped   */
      /*       data                                                       */
      /*     SFNT_Err_Table_Missing:                                      */
      /*       table directory is valid, but essential tables             */
      /*       (head/bhed/SING) are missing                               */
      /*                                                                  */
      static FT_Error
      check_table_dir( SFNT_Header  sfnt,
                       FT_Stream    stream )
      {
        FT_Error   error;
        FT_UShort  nn, valid_entries = 0;
        FT_UInt    has_head = 0, has_sing = 0, has_meta = 0;
        FT_ULong   offset = sfnt->offset + 12;
    
        static const FT_Frame_Field  table_dir_entry_fields[] =
        {
    #undef  FT_STRUCTURE
    #define FT_STRUCTURE  TT_TableRec
    
          FT_FRAME_START( 16 ),
            FT_FRAME_ULONG( Tag ),
            FT_FRAME_ULONG( CheckSum ),
            FT_FRAME_ULONG( Offset ),
            FT_FRAME_ULONG( Length ),
          FT_FRAME_END
        };
    
    
        if ( FT_STREAM_SEEK( offset ) )
          goto Exit;
    
        for ( nn = 0; nn < sfnt->num_tables; nn++ )
        {
          TT_TableRec  table;
    
    
          if ( FT_STREAM_READ_FIELDS( table_dir_entry_fields, &table ) )
          {
            nn--;
            FT_TRACE2(( "check_table_dir:"
                        " can read only %d table%s in font (instead of %d)\n",
                        nn, nn == 1 ? "" : "s", sfnt->num_tables ));
            sfnt->num_tables = nn;
            break;
          }
    
          /* we ignore invalid tables */
          if ( table.Offset + table.Length > stream->size )
          {
            FT_TRACE2(( "check_table_dir: table entry %d invalid\n", nn ));
            continue;
          }
          else
            valid_entries++;
    
          if ( table.Tag == TTAG_head || table.Tag == TTAG_bhed )
          {
            FT_UInt32  magic;
    
    
    #ifndef TT_CONFIG_OPTION_EMBEDDED_BITMAPS
            if ( table.Tag == TTAG_head )
    #endif
              has_head = 1;
    
            /*
             * The table length should be 0x36, but certain font tools make it
             * 0x38, so we will just check that it is greater.
             *
             * Note that according to the specification, the table must be
             * padded to 32-bit lengths, but this doesn't apply to the value of
             * its `Length' field!
             *
             */
            if ( table.Length < 0x36 )
            {
              FT_TRACE2(( "check_table_dir: `head' table too small\n" ));
              error = SFNT_Err_Table_Missing;
              goto Exit;
            }
    
            if ( FT_STREAM_SEEK( table.Offset + 12 ) ||
                 FT_READ_ULONG( magic )              )
              goto Exit;
    
            if ( magic != 0x5F0F3CF5UL )
            {
              FT_TRACE2(( "check_table_dir:"
                          " no magic number found in `head' table\n"));
              error = SFNT_Err_Table_Missing;
              goto Exit;
            }
    
            if ( FT_STREAM_SEEK( offset + ( nn + 1 ) * 16 ) )
              goto Exit;
          }
          else if ( table.Tag == TTAG_SING )
            has_sing = 1;
          else if ( table.Tag == TTAG_META )
            has_meta = 1;
        }
    
        sfnt->num_tables = valid_entries;
    
        if ( sfnt->num_tables == 0 )
        {
          FT_TRACE2(( "check_table_dir: no tables found\n" ));
          error = SFNT_Err_Unknown_File_Format;
          goto Exit;
        }
    
        /* if `sing' and `meta' tables are present, there is no `head' table */
        if ( has_head || ( has_sing && has_meta ) )
        {
          error = SFNT_Err_Ok;
          goto Exit;
        }
        else
        {
          FT_TRACE2(( "check_table_dir:" ));
    #ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS
          FT_TRACE2(( " neither `head', `bhed', nor `sing' table found\n" ));
    #else
          FT_TRACE2(( " neither `head' nor `sing' table found\n" ));
    #endif
          error = SFNT_Err_Table_Missing;
        }
    
      Exit:
        return error;
      }
    
    
      /*************************************************************************/
      /*                                                                       */
      /* <Function>                                                            */
      /*    tt_face_load_font_dir                                              */
      /*                                                                       */
      /* <Description>                                                         */
      /*    Loads the header of a SFNT font file.                              */
      /*                                                                       */
      /* <Input>                                                               */
      /*    face       :: A handle to the target face object.                  */
      /*                                                                       */
      /*    stream     :: The input stream.                                    */
      /*                                                                       */
      /* <Output>                                                              */
      /*    sfnt       :: The SFNT header.                                     */
      /*                                                                       */
      /* <Return>                                                              */
      /*    FreeType error code.  0 means success.                             */
      /*                                                                       */
      /* <Note>                                                                */
      /*    The stream cursor must be at the beginning of the font directory.  */
      /*                                                                       */
      FT_LOCAL_DEF( FT_Error )
      tt_face_load_font_dir( TT_Face    face,
                             FT_Stream  stream )
      {
        SFNT_HeaderRec  sfnt;
        FT_Error        error;
        FT_Memory       memory = stream->memory;
        TT_TableRec*    entry;
        FT_Int          nn;
    
        static const FT_Frame_Field  offset_table_fields[] =
        {
    #undef  FT_STRUCTURE
    #define FT_STRUCTURE  SFNT_HeaderRec
    
          FT_FRAME_START( 8 ),
            FT_FRAME_USHORT( num_tables ),
            FT_FRAME_USHORT( search_range ),
            FT_FRAME_USHORT( entry_selector ),
            FT_FRAME_USHORT( range_shift ),
          FT_FRAME_END
        };
    
    
        FT_TRACE2(( "tt_face_load_font_dir: %08p\n", face ));
    
        /* read the offset table */
    
        sfnt.offset = FT_STREAM_POS();
    
        if ( FT_READ_ULONG( sfnt.format_tag )                    ||
             FT_STREAM_READ_FIELDS( offset_table_fields, &sfnt ) )
          goto Exit;
    
        /* many fonts don't have these fields set correctly */
    #if 0
        if ( sfnt.search_range != 1 << ( sfnt.entry_selector + 4 )        ||
             sfnt.search_range + sfnt.range_shift != sfnt.num_tables << 4 )
          return SFNT_Err_Unknown_File_Format;
    #endif
    
        /* load the table directory */
    
        FT_TRACE2(( "-- Number of tables: %10u\n",    sfnt.num_tables ));
        FT_TRACE2(( "-- Format version:   0x%08lx\n", sfnt.format_tag ));
    
        /* check first */
        error = check_table_dir( &sfnt, stream );
        if ( error )
        {
          FT_TRACE2(( "tt_face_load_font_dir:"
                      " invalid table directory for TrueType\n" ));
    
          goto Exit;
        }
    
        face->num_tables = sfnt.num_tables;
        face->format_tag = sfnt.format_tag;
    
        if ( FT_QNEW_ARRAY( face->dir_tables, face->num_tables ) )
          goto Exit;
    
        if ( FT_STREAM_SEEK( sfnt.offset + 12 )       ||
             FT_FRAME_ENTER( face->num_tables * 16L ) )
          goto Exit;
    
        entry = face->dir_tables;
    
        FT_TRACE2(( "\n"
                    "  tag    offset    length   checksum\n"
                    "  ----------------------------------\n" ));
    
        for ( nn = 0; nn < sfnt.num_tables; nn++ )
        {
          entry->Tag      = FT_GET_TAG4();
          entry->CheckSum = FT_GET_ULONG();
          entry->Offset   = FT_GET_LONG();
          entry->Length   = FT_GET_LONG();
    
          /* ignore invalid tables */
          if ( entry->Offset + entry->Length > stream->size )
            continue;
          else
          {
            FT_TRACE2(( "  %c%c%c%c  %08lx  %08lx  %08lx\n",
                        (FT_Char)( entry->Tag >> 24 ),
                        (FT_Char)( entry->Tag >> 16 ),
                        (FT_Char)( entry->Tag >> 8  ),
                        (FT_Char)( entry->Tag       ),
                        entry->Offset,
                        entry->Length,
                        entry->CheckSum ));
            entry++;
          }
        }
    
        FT_FRAME_EXIT();
    
        FT_TRACE2(( "table directory loaded\n\n" ));
    
      Exit:
        return error;
      }
    
    
      /*************************************************************************/
      /*                                                                       */
      /* <Function>                                                            */
      /*    tt_face_load_any                                                   */
      /*                                                                       */
      /* <Description>                                                         */
      /*    Loads any font table into client memory.                           */
      /*                                                                       */
      /* <Input>                                                               */
      /*    face   :: The face object to look for.                             */
      /*                                                                       */
      /*    tag    :: The tag of table to load.  Use the value 0 if you want   */
      /*              to access the whole font file, else set this parameter   */
      /*              to a valid TrueType table tag that you can forge with    */
      /*              the MAKE_TT_TAG macro.                                   */
      /*                                                                       */
      /*    offset :: The starting offset in the table (or the file if         */
      /*              tag == 0).                                               */
      /*                                                                       */
      /*    length :: The address of the decision variable:                    */
      /*                                                                       */
      /*                If length == NULL:                                     */
      /*                  Loads the whole table.  Returns an error if          */
      /*                  `offset' == 0!                                       */
      /*                                                                       */
      /*                If *length == 0:                                       */
      /*                  Exits immediately; returning the length of the given */
      /*                  table or of the font file, depending on the value of */
      /*                  `tag'.                                               */
      /*                                                                       */
      /*                If *length != 0:                                       */
      /*                  Loads the next `length' bytes of table or font,      */
      /*                  starting at offset `offset' (in table or font too).  */
      /*                                                                       */
      /* <Output>                                                              */
      /*    buffer :: The address of target buffer.                            */
      /*                                                                       */
      /* <Return>                                                              */
      /*    FreeType error code.  0 means success.                             */
      /*                                                                       */
      FT_LOCAL_DEF( FT_Error )
      tt_face_load_any( TT_Face    face,
                        FT_ULong   tag,
                        FT_Long    offset,
                        FT_Byte*   buffer,
                        FT_ULong*  length )
      {
        FT_Error   error;
        FT_Stream  stream;
        TT_Table   table;
        FT_ULong   size;
    
    
        if ( tag != 0 )
        {
          /* look for tag in font directory */
          table = tt_face_lookup_table( face, tag );
          if ( !table )
          {
            error = SFNT_Err_Table_Missing;
            goto Exit;
          }
    
          offset += table->Offset;
          size    = table->Length;
        }
        else
          /* tag == 0 -- the user wants to access the font file directly */
          size = face->root.stream->size;
    
        if ( length && *length == 0 )
        {
          *length = size;
    
          return SFNT_Err_Ok;
        }
    
        if ( length )
          size = *length;
    
        stream = face->root.stream;
        /* the `if' is syntactic sugar for picky compilers */
        if ( FT_STREAM_READ_AT( offset, buffer, size ) )
          goto Exit;
    
      Exit:
        return error;
      }
    
    
      /*************************************************************************/
      /*                                                                       */
      /* <Function>                                                            */
      /*    tt_face_load_generic_header                                        */
      /*                                                                       */
      /* <Description>                                                         */
      /*    Loads the TrueType table `head' or `bhed'.                         */
      /*                                                                       */
      /* <Input>                                                               */
      /*    face   :: A handle to the target face object.                      */
      /*                                                                       */
      /*    stream :: The input stream.                                        */
      /*                                                                       */
      /* <Return>                                                              */
      /*    FreeType error code.  0 means success.                             */
      /*                                                                       */
      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;
      }
    
    
      FT_LOCAL_DEF( FT_Error )
      tt_face_load_head( TT_Face    face,
                         FT_Stream  stream )
      {
        return tt_face_load_generic_header( face, stream, TTAG_head );
      }
    
    
    #ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS
    
      FT_LOCAL_DEF( FT_Error )
      tt_face_load_bhed( TT_Face    face,
                         FT_Stream  stream )
      {
        return tt_face_load_generic_header( face, stream, TTAG_bhed );
      }
    
    #endif /* TT_CONFIG_OPTION_EMBEDDED_BITMAPS */
    
    
      /*************************************************************************/
      /*                                                                       */
      /* <Function>                                                            */
      /*    tt_face_load_max_profile                                           */
      /*                                                                       */
      /* <Description>                                                         */
      /*    Loads the maximum profile into a face object.                      */
      /*                                                                       */
      /* <Input>                                                               */
      /*    face   :: A handle to the target face object.                      */
      /*                                                                       */
      /*    stream :: The input stream.                                        */
      /*                                                                       */
      /* <Return>                                                              */
      /*    FreeType error code.  0 means success.                             */
      /*                                                                       */
      FT_LOCAL_DEF( FT_Error )
      tt_face_load_maxp( TT_Face    face,
                         FT_Stream  stream )
      {
        FT_Error        error;
        TT_MaxProfile*  maxProfile = &face->max_profile;
    
        const FT_Frame_Field  maxp_fields[] =
        {
    #undef  FT_STRUCTURE
    #define FT_STRUCTURE  TT_MaxProfile
    
          FT_FRAME_START( 6 ),
            FT_FRAME_LONG  ( version ),
            FT_FRAME_USHORT( numGlyphs ),
          FT_FRAME_END
        };
    
        const FT_Frame_Field  maxp_fields_extra[] =
        {
          FT_FRAME_START( 26 ),
            FT_FRAME_USHORT( maxPoints ),
            FT_FRAME_USHORT( maxContours ),
            FT_FRAME_USHORT( maxCompositePoints ),
            FT_FRAME_USHORT( maxCompositeContours ),
            FT_FRAME_USHORT( maxZones ),
            FT_FRAME_USHORT( maxTwilightPoints ),
            FT_FRAME_USHORT( maxStorage ),
            FT_FRAME_USHORT( maxFunctionDefs ),
            FT_FRAME_USHORT( maxInstructionDefs ),
            FT_FRAME_USHORT( maxStackElements ),
            FT_FRAME_USHORT( maxSizeOfInstructions ),
            FT_FRAME_USHORT( maxComponentElements ),
            FT_FRAME_USHORT( maxComponentDepth ),
          FT_FRAME_END
        };
    
    
        error = face->goto_table( face, TTAG_maxp, stream, 0 );
        if ( error )
          goto Exit;
    
        if ( FT_STREAM_READ_FIELDS( maxp_fields, maxProfile ) )
          goto Exit;
    
        maxProfile->maxPoints             = 0;
        maxProfile->maxContours           = 0;
        maxProfile->maxCompositePoints    = 0;
        maxProfile->maxCompositeContours  = 0;
        maxProfile->maxZones              = 0;
        maxProfile->maxTwilightPoints     = 0;
        maxProfile->maxStorage            = 0;
        maxProfile->maxFunctionDefs       = 0;
        maxProfile->maxInstructionDefs    = 0;
        maxProfile->maxStackElements      = 0;
        maxProfile->maxSizeOfInstructions = 0;
        maxProfile->maxComponentElements  = 0;
        maxProfile->maxComponentDepth     = 0;
    
        if ( maxProfile->version >= 0x10000L )
        {
          if ( FT_STREAM_READ_FIELDS( maxp_fields_extra, maxProfile ) )
            goto Exit;
    
          /* XXX: an adjustment that is necessary to load certain */
          /*      broken fonts like `Keystrokes MT' :-(           */
          /*                                                      */
          /*   We allocate 64 function entries by default when    */
          /*   the maxFunctionDefs value is smaller.              */
    
          if ( maxProfile->maxFunctionDefs < 64 )
            maxProfile->maxFunctionDefs = 64;
    
          /* we add 4 phantom points later */
          if ( maxProfile->maxTwilightPoints > ( 0xFFFFU - 4 ) )
          {
            FT_TRACE0(( "tt_face_load_maxp:"
                        " too much twilight points in `maxp' table;\n"
                        "                  "
                        " some glyphs might be rendered incorrectly\n" ));
    
            maxProfile->maxTwilightPoints = 0xFFFFU - 4;
          }
    
          /* we arbitrarily limit recursion to avoid stack exhaustion */
          if ( maxProfile->maxComponentDepth > 100 )
          {
            FT_TRACE0(( "tt_face_load_maxp:"
                        " abnormally large component depth (%d) set to 100\n",
                        maxProfile->maxComponentDepth ));
            maxProfile->maxComponentDepth = 100;
          }
        }
    
        FT_TRACE3(( "numGlyphs: %u\n", maxProfile->numGlyphs ));
    
      Exit:
        return error;
      }
    
    
      /*************************************************************************/
      /*                                                                       */
      /* <Function>                                                            */
      /*    tt_face_load_names                                                 */
      /*                                                                       */
      /* <Description>                                                         */
      /*    Loads the name records.                                            */
      /*                                                                       */
      /* <Input>                                                               */
      /*    face   :: A handle to the target face object.                      */
      /*                                                                       */
      /*    stream :: The input stream.                                        */
      /*                                                                       */
      /* <Return>                                                              */
      /*    FreeType error code.  0 means success.                             */
      /*                                                                       */
      FT_LOCAL_DEF( FT_Error )
      tt_face_load_name( TT_Face    face,
                         FT_Stream  stream )
      {
        FT_Error      error;
        FT_Memory     memory = stream->memory;
        FT_ULong      table_pos, table_len;
        FT_ULong      storage_start, storage_limit;
        FT_UInt       count;
        TT_NameTable  table;
    
        static const FT_Frame_Field  name_table_fields[] =
        {
    #undef  FT_STRUCTURE
    #define FT_STRUCTURE  TT_NameTableRec
    
          FT_FRAME_START( 6 ),
            FT_FRAME_USHORT( format ),
            FT_FRAME_USHORT( numNameRecords ),
            FT_FRAME_USHORT( storageOffset ),
          FT_FRAME_END
        };
    
        static const FT_Frame_Field  name_record_fields[] =
        {
    #undef  FT_STRUCTURE
    #define FT_STRUCTURE  TT_NameEntryRec
    
          /* no FT_FRAME_START */
            FT_FRAME_USHORT( platformID ),
            FT_FRAME_USHORT( encodingID ),
            FT_FRAME_USHORT( languageID ),
            FT_FRAME_USHORT( nameID ),
            FT_FRAME_USHORT( stringLength ),
            FT_FRAME_USHORT( stringOffset ),
          FT_FRAME_END
        };
    
    
        table         = &face->name_table;
        table->stream = stream;
    
        error = face->goto_table( face, TTAG_name, stream, &table_len );
        if ( error )
          goto Exit;
    
        table_pos = FT_STREAM_POS();
    
    
        if ( FT_STREAM_READ_FIELDS( name_table_fields, table ) )
          goto Exit;
    
        /* Some popular Asian fonts have an invalid `storageOffset' value   */
        /* (it should be at least "6 + 12*num_names").  However, the string */
        /* offsets, computed as "storageOffset + entry->stringOffset", are  */
        /* valid pointers within the name table...                          */
        /*                                                                  */
        /* We thus can't check `storageOffset' right now.                   */
        /*                                                                  */
        storage_start = table_pos + 6 + 12*table->numNameRecords;
        storage_limit = table_pos + table_len;
    
        if ( storage_start > storage_limit )
        {
          FT_ERROR(( "tt_face_load_name: invalid `name' table\n" ));
          error = SFNT_Err_Name_Table_Missing;
          goto Exit;
        }
    
        /* Allocate the array of name records. */
        count                 = table->numNameRecords;
        table->numNameRecords = 0;
    
        if ( FT_NEW_ARRAY( table->names, count ) ||
             FT_FRAME_ENTER( count * 12 )        )
          goto Exit;
    
        /* Load the name records and determine how much storage is needed */
        /* to hold the strings themselves.                                */
        {
          TT_NameEntryRec*  entry = table->names;
    
    
          for ( ; count > 0; count-- )
          {
            if ( FT_STREAM_READ_FIELDS( name_record_fields, entry ) )
              continue;
    
            /* check that the name is not empty */
            if ( entry->stringLength == 0 )
              continue;
    
            /* check that the name string is within the table */
            entry->stringOffset += table_pos + table->storageOffset;
            if ( entry->stringOffset                       < storage_start ||
                 entry->stringOffset + entry->stringLength > storage_limit )
            {
              /* invalid entry - ignore it */
              entry->stringOffset = 0;
              entry->stringLength = 0;
              continue;
            }
    
            entry++;
          }
    
          table->numNameRecords = (FT_UInt)( entry - table->names );
        }
    
        FT_FRAME_EXIT();
    
        /* everything went well, update face->num_names */
        face->num_names = (FT_UShort) table->numNameRecords;
    
      Exit:
        return error;
      }
    
    
      /*************************************************************************/
      /*                                                                       */
      /* <Function>                                                            */
      /*    tt_face_free_names                                                 */
      /*                                                                       */
      /* <Description>                                                         */
      /*    Frees the name records.                                            */
      /*                                                                       */
      /* <Input>                                                               */
      /*    face :: A handle to the target face object.                        */
      /*                                                                       */
      FT_LOCAL_DEF( void )
      tt_face_free_name( TT_Face  face )
      {
        FT_Memory     memory = face->root.driver->root.memory;
        TT_NameTable  table  = &face->name_table;
        TT_NameEntry  entry  = table->names;
        FT_UInt       count  = table->numNameRecords;
    
    
        if ( table->names )
        {
          for ( ; count > 0; count--, entry++ )
          {
            FT_FREE( entry->string );
            entry->stringLength = 0;
          }
    
          /* free strings table */
          FT_FREE( table->names );
        }
    
        table->numNameRecords = 0;
        table->format         = 0;
        table->storageOffset  = 0;
      }
    
    
      /*************************************************************************/
      /*                                                                       */
      /* <Function>                                                            */
      /*    tt_face_load_cmap                                                  */
      /*                                                                       */
      /* <Description>                                                         */
      /*    Loads the cmap directory in a face object.  The cmaps themselves   */
      /*    are loaded on demand in the `ttcmap.c' module.                     */
      /*                                                                       */
      /* <Input>                                                               */
      /*    face   :: A handle to the target face object.                      */
      /*                                                                       */
      /*    stream :: A handle to the input stream.                            */
      /*                                                                       */
      /* <Return>                                                              */
      /*    FreeType error code.  0 means success.                             */
      /*                                                                       */
    
      FT_LOCAL_DEF( FT_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;
      }
    
    
    
      /*************************************************************************/
      /*                                                                       */
      /* <Function>                                                            */
      /*    tt_face_load_os2                                                   */
      /*                                                                       */
      /* <Description>                                                         */
      /*    Loads the OS2 table.                                               */
      /*                                                                       */
      /* <Input>                                                               */
      /*    face   :: A handle to the target face object.                      */
      /*                                                                       */
      /*    stream :: A handle to the input stream.                            */
      /*                                                                       */
      /* <Return>                                                              */
      /*    FreeType error code.  0 means success.                             */
      /*                                                                       */
      FT_LOCAL_DEF( FT_Error )
      tt_face_load_os2( TT_Face    face,
                        FT_Stream  stream )
      {
        FT_Error  error;
        TT_OS2*   os2;
    
        const FT_Frame_Field  os2_fields[] =
        {
    #undef  FT_STRUCTURE
    #define FT_STRUCTURE  TT_OS2
    
          FT_FRAME_START( 78 ),
            FT_FRAME_USHORT( version ),
            FT_FRAME_SHORT ( xAvgCharWidth ),
            FT_FRAME_USHORT( usWeightClass ),
            FT_FRAME_USHORT( usWidthClass ),
            FT_FRAME_SHORT ( fsType ),
            FT_FRAME_SHORT ( ySubscriptXSize ),
            FT_FRAME_SHORT ( ySubscriptYSize ),
            FT_FRAME_SHORT ( ySubscriptXOffset ),
            FT_FRAME_SHORT ( ySubscriptYOffset ),
            FT_FRAME_SHORT ( ySuperscriptXSize ),
            FT_FRAME_SHORT ( ySuperscriptYSize ),
            FT_FRAME_SHORT ( ySuperscriptXOffset ),
            FT_FRAME_SHORT ( ySuperscriptYOffset ),
            FT_FRAME_SHORT ( yStrikeoutSize ),
            FT_FRAME_SHORT ( yStrikeoutPosition ),
            FT_FRAME_SHORT ( sFamilyClass ),
            FT_FRAME_BYTE  ( panose[0] ),
            FT_FRAME_BYTE  ( panose[1] ),
            FT_FRAME_BYTE  ( panose[2] ),
            FT_FRAME_BYTE  ( panose[3] ),
            FT_FRAME_BYTE  ( panose[4] ),
            FT_FRAME_BYTE  ( panose[5] ),
            FT_FRAME_BYTE  ( panose[6] ),
            FT_FRAME_BYTE  ( panose[7] ),
            FT_FRAME_BYTE  ( panose[8] ),
            FT_FRAME_BYTE  ( panose[9] ),
            FT_FRAME_ULONG ( ulUnicodeRange1 ),
            FT_FRAME_ULONG ( ulUnicodeRange2 ),
            FT_FRAME_ULONG ( ulUnicodeRange3 ),
            FT_FRAME_ULONG ( ulUnicodeRange4 ),
            FT_FRAME_BYTE  ( achVendID[0] ),
            FT_FRAME_BYTE  ( achVendID[1] ),
            FT_FRAME_BYTE  ( achVendID[2] ),
            FT_FRAME_BYTE  ( achVendID[3] ),
    
            FT_FRAME_USHORT( fsSelection ),
            FT_FRAME_USHORT( usFirstCharIndex ),
            FT_FRAME_USHORT( usLastCharIndex ),
            FT_FRAME_SHORT ( sTypoAscender ),
            FT_FRAME_SHORT ( sTypoDescender ),
            FT_FRAME_SHORT ( sTypoLineGap ),
            FT_FRAME_USHORT( usWinAscent ),
            FT_FRAME_USHORT( usWinDescent ),
          FT_FRAME_END
        };
    
        const FT_Frame_Field  os2_fields_extra[] =
        {
          FT_FRAME_START( 8 ),
            FT_FRAME_ULONG( ulCodePageRange1 ),
            FT_FRAME_ULONG( ulCodePageRange2 ),
          FT_FRAME_END
        };
    
        const FT_Frame_Field  os2_fields_extra2[] =
        {
          FT_FRAME_START( 10 ),
            FT_FRAME_SHORT ( sxHeight ),
            FT_FRAME_SHORT ( sCapHeight ),
            FT_FRAME_USHORT( usDefaultChar ),
            FT_FRAME_USHORT( usBreakChar ),
            FT_FRAME_USHORT( usMaxContext ),
          FT_FRAME_END
        };
    
    
        /* We now support old Mac fonts where the OS/2 table doesn't  */
        /* exist.  Simply put, we set the `version' field to 0xFFFF   */
        /* and test this value each time we need to access the table. */
        error = face->goto_table( face, TTAG_OS2, stream, 0 );
        if ( error )
          goto Exit;
    
        os2 = &face->os2;
    
        if ( FT_STREAM_READ_FIELDS( os2_fields, os2 ) )
          goto Exit;
    
        os2->ulCodePageRange1 = 0;
        os2->ulCodePageRange2 = 0;
        os2->sxHeight         = 0;
        os2->sCapHeight       = 0;
        os2->usDefaultChar    = 0;
        os2->usBreakChar      = 0;
        os2->usMaxContext     = 0;
    
        if ( os2->version >= 0x0001 )
        {
          /* only version 1 tables */
          if ( FT_STREAM_READ_FIELDS( os2_fields_extra, os2 ) )
            goto Exit;
    
          if ( os2->version >= 0x0002 )
          {
            /* only version 2 tables */
            if ( FT_STREAM_READ_FIELDS( os2_fields_extra2, os2 ) )
              goto Exit;
          }
        }
    
        FT_TRACE3(( "sTypoAscender:  %4d\n",   os2->sTypoAscender ));
        FT_TRACE3(( "sTypoDescender: %4d\n",   os2->sTypoDescender ));
        FT_TRACE3(( "usWinAscent:    %4u\n",   os2->usWinAscent ));
        FT_TRACE3(( "usWinDescent:   %4u\n",   os2->usWinDescent ));
        FT_TRACE3(( "fsSelection:    0x%2x\n", os2->fsSelection ));
    
      Exit:
        return error;
      }
    
    
      /*************************************************************************/
      /*                                                                       */
      /* <Function>                                                            */
      /*    tt_face_load_postscript                                            */
      /*                                                                       */
      /* <Description>                                                         */
      /*    Loads the Postscript table.                                        */
      /*                                                                       */
      /* <Input>                                                               */
      /*    face   :: A handle to the target face object.                      */
      /*                                                                       */
      /*    stream :: A handle to the input stream.                            */
      /*                                                                       */
      /* <Return>                                                              */
      /*    FreeType error code.  0 means success.                             */
      /*                                                                       */
      FT_LOCAL_DEF( FT_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;
      }
    
    
      /*************************************************************************/
      /*                                                                       */
      /* <Function>                                                            */
      /*    tt_face_load_pclt                                                  */
      /*                                                                       */
      /* <Description>                                                         */
      /*    Loads the PCL 5 Table.                                             */
      /*                                                                       */
      /* <Input>                                                               */
      /*    face   :: A handle to the target face object.                      */
      /*                                                                       */
      /*    stream :: A handle to the input stream.                            */
      /*                                                                       */
      /* <Return>                                                              */
      /*    FreeType error code.  0 means success.                             */
      /*                                                                       */
      FT_LOCAL_DEF( FT_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;
      }
    
    
      /*************************************************************************/
      /*                                                                       */
      /* <Function>                                                            */
      /*    tt_face_load_gasp                                                  */
      /*                                                                       */
      /* <Description>                                                         */
      /*    Loads the `gasp' table into a face object.                         */
      /*                                                                       */
      /* <Input>                                                               */
      /*    face   :: A handle to the target face object.                      */
      /*                                                                       */
      /*    stream :: The input stream.                                        */
      /*                                                                       */
      /* <Return>                                                              */
      /*    FreeType error code.  0 means success.                             */
      /*                                                                       */
      FT_LOCAL_DEF( FT_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;
      }
    
    
    /* END */