ttload.c

奇趣公司比较新的qt/emd版本

  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 field is null.                 */

      if ( maxProfile->maxFunctionDefs == 0 )
        maxProfile->maxFunctionDefs = 64;
    }

    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(( "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 )
    {