TiledInputFile::rawTileData (int &dx, int &dy,
			     int &lx, int &ly,
                             const char *&pixelData,
			     int &pixelDataSize)
{
    try
    {
        Lock lock (*_data->_streamData);

        if (!isValidTile (dx, dy, lx, ly))
            throw IEX_NAMESPACE::ArgExc ("Tried to read a tile outside "
			       "the image file's data window.");

        TileBuffer *tileBuffer = _data->getTileBuffer (0);

        //
        // if file is a multipart file, we have to seek to the required tile
        // since we don't know where the file pointer is
        //
        int old_dx=dx;
        int old_dy=dy;
        int old_lx=lx;
        int old_ly=ly;
        if(isMultiPart(version()))
        {
            _data->_streamData->is->seekg(_data->tileOffsets(dx,dy,lx,ly));
        }
        readNextTileData (_data->_streamData, _data, dx, dy, lx, ly,
			  tileBuffer->buffer,
                          pixelDataSize);
        if(isMultiPart(version()))
        {
            if (old_dx!=dx || old_dy !=dy || old_lx!=lx || old_ly!=ly)
            {
                throw IEX_NAMESPACE::ArgExc ("rawTileData read the wrong tile");
            }
        }
        else
        {
             if(!isValidTile (dx, dy, lx, ly) )
             {
                 throw IEX_NAMESPACE::IoExc ("rawTileData read an invalid tile");
             }
        }
        pixelData = tileBuffer->buffer;
    }
    catch (IEX_NAMESPACE::BaseExc &e)
    {
        REPLACE_EXC (e, "Error reading pixel data from image "
                     "file \"" << fileName() << "\". " << e.what());
        throw;
    }
}
Unknown