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</o:shapelayout></xml><![endif]--></head><body lang=DE link="#0563C1" vlink="#954F72"><div class=WordSection1><p class=MsoNormal><span lang=EN-US>Hi!<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>I wrote a basic rasterdata plugin for gdal using the raster driver api. It should provide custom rendered overviews in Quantum GIS, which is not working yet.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>When loading the plugin in QGIS, it is displayed as VRT Format, which should not be because I never reference the VRT Dataset or anything related.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>Also I noticed that the callstack when rendering an image in QGIS is far different from what I would expect:<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>> gdal_RNDd.dll!RNDRasterBand::IRasterIO(GDALRWFlag eRWFlag, int nXOff, int nYOff, int nXSize, int nYSize, void * pData, int nBufXSize, int nBufYSize, GDALDataType eBufType, int nPixelSpace, int nLineSpace) Line 107 gdal111.dll!GDALRasterBand::RasterIO(GDALRWFlag eRWFlag, int nXOff, int nYOff, int nXSize, int nYSize, void * pData, int nBufXSize, int nBufYSize, GDALDataType eBufType, int nPixelSpace, int nLineSpace) Line 261 gdal_RNDd.dll!RNDDataset::IRasterIO(GDALRWFlag eRWFlag, int nXOff, int nYOff, int nXSize, int nYSize, void * pData, int nBufXSize, int nBufYSize, GDALDataType eBufType, int nBandCount, int * panBandMap, int nPixelSpace, int nLineSpace, int nBandSpace) Line 124 + 0x8b bytes<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> gdal111.dll!GDALDataset::RasterIO(GDALRWFlag eRWFlag, int nXOff, int nYOff, int nXSize, int nYSize, void * pData, int nBufXSize, int nBufYSize, GDALDataType eBufType, int nBandCount, int * panBandMap, int nPixelSpace, int nLineSpace, int nBandSpace) Line 1758 + 0xaa bytes<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> gdal111.dll!GDALDatasetRasterIO(void * hDS, GDALRWFlag eRWFlag, int nXOff, int nYOff, int nXSize, int nYSize, void * pData, int nBufXSize, int nBufYSize, GDALDataType eBufType, int nBandCount, int * panBandMap, int nPixelSpace, int nLineSpace, int nBandSpace) Line 1797<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> gdal111.dll!GDALWarpOperation::WarpRegionToBuffer(int nDstXOff, int nDstYOff, int nDstXSize, int nDstYSize, void * pDataBuf, GDALDataType eBufDataType, int nSrcXOff, int nSrcYOff, int nSrcXSize, int nSrcYSize, double dfProgressBase, double dfProgressScale) Line 1527 + 0xe0 bytes<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> gdal111.dll!VRTWarpedDataset::ProcessBlock(int iBlockX, int iBlockY) Line 1180 + 0xbe bytes<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> gdal111.dll!VRTWarpedRasterBand::IReadBlock(int nBlockXOff, int nBlockYOff, void * pImage) Line 1288 + 0x13 bytes<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> gdal111.dll!GDALRasterBand::GetLockedBlockRef(int nXBlockOff, int nYBlockOff, int bJustInitialize) Line 1243 + 0x50 bytes<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> gdal111.dll!GDALRasterBand::IRasterIO(GDALRWFlag eRWFlag, int nXOff, int nYOff, int nXSize, int nYSize, void * pData, int nBufXSize, int nBufYSize, GDALDataType eBufType, int nPixelSpace, int nLineSpace) Line 484 + 0x1f bytes<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> gdal111.dll!GDALRasterBand::RasterIO(GDALRWFlag eRWFlag, int nXOff, int nYOff, int nXSize, int nYSize, void * pData, int nBufXSize, int nBufYSize, GDALDataType eBufType, int nPixelSpace, int nLineSpace) Line 261<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> gdal111.dll!GDALRasterIO(void * hBand, GDALRWFlag eRWFlag, int nXOff, int nYOff, int nXSize, int nYSize, void * pData, int nBufXSize, int nBufYSize, GDALDataType eBufType, int nPixelSpace, int nLineSpace) Line 288<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> [….]<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>Notice that there are VRTWarpedDataset and VRTWarpedRasterBand functions involved which I never used anywhere in my driver source.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>I would expect GDALRasterBand::RasterIO (second from bottom) to call my overridden implementation of RNDRasterBand::IrasterIO (top) directly instead of GDALRasterBand::IRasterIO (third from bottom) and all the functions in between.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> <o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>Here are my class definitions for reference:<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas;color:blue'>class</span><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> RNDDataset : <span style='color:blue'>public</span> GDALDataset<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'>{<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> <span style='color:blue'>friend</span> <span style='color:blue'>class</span> RNDRasterBand;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas;color:blue'>public</span><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'>:<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> <span style='color:blue'>virtual</span> ~RNDDataset ();<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> <span style='color:blue'>virtual</span> CPLErr GetGeoTransform ( <span style='color:blue'>double</span> * padfTransform );<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> <span style='color:blue'>virtual</span> <span style='color:blue'>char</span> <span style='color:blue'>const</span> * GetProjectionRef();<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> <span style='color:blue'>static</span> <span style='color:blue'>int</span> Identify ( GDALOpenInfo * openInfo );<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> <span style='color:blue'>static</span> GDALDataset * Open ( GDALOpenInfo * openInfo );<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas;color:blue'>protected</span><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'>:<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> RNDDataset ();<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> <span style='color:blue'>virtual</span> CPLErr IRasterIO ( GDALRWFlag eRWFlag,<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> <span style='color:blue'>int</span> nXOff, <span style='color:blue'>int</span> nYOff, <span style='color:blue'>int</span> nXSize, <span style='color:blue'>int</span> nYSize,<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> <span style='color:blue'>void</span> * pData, <span style='color:blue'>int</span> nBufXSize, <span style='color:blue'>int</span> nBufYSize,<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> GDALDataType eBufType, <o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> <span style='color:blue'>int</span> nBandCount, <span style='color:blue'>int</span> *panBandMap,<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> <span style='color:blue'>int</span> nPixelSpace, <span style='color:blue'>int</span> nLineSpace, <span style='color:blue'>int</span> nBandSpace );<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>}<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas;color:blue'>class</span><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> RNDRasterBand : <span style='color:blue'>public</span> GDALRasterBand<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'>{<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> <span style='color:blue'>friend</span> <span style='color:blue'>class</span> RNDDataset;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas;color:blue'>public</span><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'>:<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> <span style='color:blue'>virtual</span> ~RNDRasterBand ();<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> <span style='color:blue'>virtual</span> GDALRasterBand * GetOverview ( <span style='color:blue'>int</span> a_iOverview );<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> <span style='color:blue'>virtual</span> <span style='color:blue'>int</span> GetOverviewCount ();<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> <span style='color:blue'>virtual</span> <span style='color:blue'>int</span> HasArbitraryOverviews();<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas;color:blue'>protected</span><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'>:<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> RNDRasterBand ( RNDDataset * <span style='color:blue'>const</span> a_poDS, <span style='color:blue'>int</span> <span style='color:blue'>const</span> a_nBand, GDALColorInterp <span style='color:blue'>const</span> a_eColorInterp, <span style='color:blue'>int</span> <span style='color:blue'>const</span> a_iOverview );<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> <span style='color:blue'>virtual</span> CPLErr IReadBlock ( <span style='color:blue'>int</span> a_nBlockXOff, <span style='color:blue'>int</span> a_nBlockYOff, <span style='color:blue'>void</span> * a_pImage );<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> </span><span style='font-size:9.5pt;font-family:Consolas;color:blue'>virtual</span><span style='font-size:9.5pt;font-family:Consolas'> CPLErr IRasterIO ( GDALRWFlag eRWFlag,<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> </span><span lang=EN-US style='font-size:9.5pt;font-family:Consolas;color:blue'>int</span><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> nXOff, <span style='color:blue'>int</span> nYOff, <span style='color:blue'>int</span> nXSize, <span style='color:blue'>int</span> nYSize,<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> <span style='color:blue'>void</span> * pData, <span style='color:blue'>int</span> nBufXSize, <span style='color:blue'>int</span> nBufYSize,<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> </span><span style='font-size:9.5pt;font-family:Consolas'>GDALDataType eBufType,<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> <span style='color:blue'>int</span> nPixelSpace, <span style='color:blue'>int</span> nLineSpace );<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>}<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>Any advise what I’m missing?<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>Thank you,<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>David<o:p></o:p></span></p></div></body></html>