GDALDatasetH QgsRasterCalculator::openOutputFile( GDALDriverH outputDriver )
{
//open output file
char **papszOptions = nullptr;
GDALDatasetH outputDataset = GDALCreate( outputDriver, TO8F( mOutputFile ), mNumOutputColumns, mNumOutputRows, 1, GDT_Float32, papszOptions );
if ( !outputDataset )
{
return outputDataset;
}
//assign georef information
double geotransform[6];
outputGeoTransform( geotransform );
GDALSetGeoTransform( outputDataset, geotransform );
return outputDataset;
}
GDALDatasetH QgsRasterCalculator::openOutputFile( GDALDriverH outputDriver )
{
//open output file
char **papszOptions = NULL;
GDALDatasetH outputDataset = GDALCreate( outputDriver, mOutputFile.toLocal8Bit().data(), mNumOutputColumns, mNumOutputRows, 1, GDT_Float32, papszOptions );
if ( outputDataset == NULL )
{
return outputDataset;
}
//assign georef information
double geotransform[6];
outputGeoTransform( geotransform );
GDALSetGeoTransform( outputDataset, geotransform );
return outputDataset;
}
gdal::dataset_unique_ptr QgsRasterCalculator::openOutputFile( GDALDriverH outputDriver )
{
//open output file
char **papszOptions = nullptr;
gdal::dataset_unique_ptr outputDataset( GDALCreate( outputDriver, mOutputFile.toUtf8().constData(), mNumOutputColumns, mNumOutputRows, 1, GDT_Float32, papszOptions ) );
if ( !outputDataset )
{
return nullptr;
}
//assign georef information
double geotransform[6];
outputGeoTransform( geotransform );
GDALSetGeoTransform( outputDataset.get(), geotransform );
return outputDataset;
}
int QgsRasterCalculator::processCalculation( QProgressDialog* p )
{
//prepare search string / tree
QString errorString;
QgsRasterCalcNode* calcNode = QgsRasterCalcNode::parseRasterCalcString( mFormulaString, errorString );
if ( !calcNode )
{
//error
}
double targetGeoTransform[6];
outputGeoTransform( targetGeoTransform );
//open all input rasters for reading
QMap< QString, GDALRasterBandH > mInputRasterBands; //raster references and corresponding scanline data
QMap< QString, QgsRasterMatrix* > inputScanLineData; //stores raster references and corresponding scanline data
QVector< GDALDatasetH > mInputDatasets; //raster references and corresponding dataset
QVector<QgsRasterCalculatorEntry>::const_iterator it = mRasterEntries.constBegin();
for ( ; it != mRasterEntries.constEnd(); ++it )
{
if ( !it->raster ) // no raster layer in entry
{
return 2;
}
GDALDatasetH inputDataset = GDALOpen( it->raster->source().toLocal8Bit().data(), GA_ReadOnly );
if ( inputDataset == NULL )
{
return 2;
}
//check if the input dataset is south up or rotated. If yes, use GDALAutoCreateWarpedVRT to create a north up raster
double inputGeoTransform[6];
if ( GDALGetGeoTransform( inputDataset, inputGeoTransform ) == CE_None
&& ( inputGeoTransform[1] < 0.0
|| inputGeoTransform[2] != 0.0
|| inputGeoTransform[4] != 0.0
|| inputGeoTransform[5] > 0.0 ) )
{
GDALDatasetH vDataset = GDALAutoCreateWarpedVRT( inputDataset, NULL, NULL, GRA_NearestNeighbour, 0.2, NULL );
mInputDatasets.push_back( vDataset );
mInputDatasets.push_back( inputDataset );
inputDataset = vDataset;
}
else
{
mInputDatasets.push_back( inputDataset );
}
GDALRasterBandH inputRasterBand = GDALGetRasterBand( inputDataset, it->bandNumber );
if ( inputRasterBand == NULL )
{
return 2;
}
int nodataSuccess;
double nodataValue = GDALGetRasterNoDataValue( inputRasterBand, &nodataSuccess );
mInputRasterBands.insert( it->ref, inputRasterBand );
inputScanLineData.insert( it->ref, new QgsRasterMatrix( mNumOutputColumns, 1, new float[mNumOutputColumns], nodataValue ) );
}
//open output dataset for writing
GDALDriverH outputDriver = openOutputDriver();
if ( outputDriver == NULL )
{
return 1;
}
GDALDatasetH outputDataset = openOutputFile( outputDriver );
GDALRasterBandH outputRasterBand = GDALGetRasterBand( outputDataset, 1 );
float outputNodataValue = -FLT_MAX;
GDALSetRasterNoDataValue( outputRasterBand, outputNodataValue );
float* resultScanLine = ( float * ) CPLMalloc( sizeof( float ) * mNumOutputColumns );
if ( p )
{
p->setMaximum( mNumOutputRows );
}
QgsRasterMatrix resultMatrix;
//read / write line by line
for ( int i = 0; i < mNumOutputRows; ++i )
{
if ( p )
{
p->setValue( i );
}
if ( p && p->wasCanceled() )
{
break;
}
//fill buffers
QMap< QString, QgsRasterMatrix* >::iterator bufferIt = inputScanLineData.begin();
for ( ; bufferIt != inputScanLineData.end(); ++bufferIt )
{
double sourceTransformation[6];
GDALRasterBandH sourceRasterBand = mInputRasterBands[bufferIt.key()];
GDALGetGeoTransform( GDALGetBandDataset( sourceRasterBand ), sourceTransformation );
//the function readRasterPart calls GDALRasterIO (and ev. does some conversion if raster transformations are not the same)
readRasterPart( targetGeoTransform, 0, i, mNumOutputColumns, 1, sourceTransformation, sourceRasterBand, bufferIt.value()->data() );
}
if ( calcNode->calculate( inputScanLineData, resultMatrix ) )
{
bool resultIsNumber = resultMatrix.isNumber();
float* calcData;
if ( resultIsNumber ) //scalar result. Insert number for every pixel
{
calcData = new float[mNumOutputColumns];
for ( int j = 0; j < mNumOutputColumns; ++j )
{
calcData[j] = resultMatrix.number();
}
}
else //result is real matrix
{
calcData = resultMatrix.data();
}
//replace all matrix nodata values with output nodatas
for ( int j = 0; j < mNumOutputColumns; ++j )
{
if ( calcData[j] == resultMatrix.nodataValue() )
{
calcData[j] = outputNodataValue;
}
}
//write scanline to the dataset
if ( GDALRasterIO( outputRasterBand, GF_Write, 0, i, mNumOutputColumns, 1, calcData, mNumOutputColumns, 1, GDT_Float32, 0, 0 ) != CE_None )
{
qWarning( "RasterIO error!" );
}
if ( resultIsNumber )
{
delete[] calcData;
}
}
}
if ( p )
{
p->setValue( mNumOutputRows );
}
//close datasets and release memory
delete calcNode;
QMap< QString, QgsRasterMatrix* >::iterator bufferIt = inputScanLineData.begin();
for ( ; bufferIt != inputScanLineData.end(); ++bufferIt )
{
delete bufferIt.value();
}
inputScanLineData.clear();
QVector< GDALDatasetH >::iterator datasetIt = mInputDatasets.begin();
for ( ; datasetIt != mInputDatasets.end(); ++ datasetIt )
{
GDALClose( *datasetIt );
}
if ( p && p->wasCanceled() )
{
//delete the dataset without closing (because it is faster)
GDALDeleteDataset( outputDriver, mOutputFile.toLocal8Bit().data() );
return 3;
}
GDALClose( outputDataset );
CPLFree( resultScanLine );
return 0;
}
