QVariantMap QgsExtractByExtentAlgorithm::processAlgorithm( const QVariantMap ¶meters, QgsProcessingContext &context, QgsProcessingFeedback *feedback ) { std::unique_ptr< QgsFeatureSource > featureSource( parameterAsSource( parameters, QStringLiteral( "INPUT" ), context ) ); if ( !featureSource ) return QVariantMap(); QgsRectangle extent = parameterAsExtent( parameters, QStringLiteral( "EXTENT" ), context, featureSource->sourceCrs() ); bool clip = parameterAsBool( parameters, QStringLiteral( "CLIP" ), context ); // if clipping, we force multi output QgsWkbTypes::Type outType = clip ? QgsWkbTypes::multiType( featureSource->wkbType() ) : featureSource->wkbType(); QString dest; std::unique_ptr< QgsFeatureSink > sink( parameterAsSink( parameters, QStringLiteral( "OUTPUT" ), context, dest, featureSource->fields(), outType, featureSource->sourceCrs() ) ); if ( !sink ) return QVariantMap(); QgsGeometry clipGeom = parameterAsExtentGeometry( parameters, QStringLiteral( "EXTENT" ), context, featureSource->sourceCrs() ); double step = featureSource->featureCount() > 0 ? 100.0 / featureSource->featureCount() : 1; QgsFeatureIterator inputIt = featureSource->getFeatures( QgsFeatureRequest().setFilterRect( extent ).setFlags( QgsFeatureRequest::ExactIntersect ) ); QgsFeature f; int i = -1; while ( inputIt.nextFeature( f ) ) { i++; if ( feedback->isCanceled() ) { break; } if ( clip ) { QgsGeometry g = f.geometry().intersection( clipGeom ); g.convertToMultiType(); f.setGeometry( g ); } sink->addFeature( f, QgsFeatureSink::FastInsert ); feedback->setProgress( i * step ); } QVariantMap outputs; outputs.insert( QStringLiteral( "OUTPUT" ), dest ); return outputs; }
QVariantMap QgsClipAlgorithm::processAlgorithm( const QVariantMap ¶meters, QgsProcessingContext &context, QgsProcessingFeedback *feedback ) { std::unique_ptr< QgsFeatureSource > featureSource( parameterAsSource( parameters, QStringLiteral( "INPUT" ), context ) ); if ( !featureSource ) throw QgsProcessingException( invalidSourceError( parameters, QStringLiteral( "INPUT" ) ) ); std::unique_ptr< QgsFeatureSource > maskSource( parameterAsSource( parameters, QStringLiteral( "OVERLAY" ), context ) ); if ( !maskSource ) throw QgsProcessingException( invalidSourceError( parameters, QStringLiteral( "OVERLAY" ) ) ); QString dest; QgsWkbTypes::GeometryType sinkType = QgsWkbTypes::geometryType( featureSource->wkbType() ); std::unique_ptr< QgsFeatureSink > sink( parameterAsSink( parameters, QStringLiteral( "OUTPUT" ), context, dest, featureSource->fields(), QgsWkbTypes::multiType( featureSource->wkbType() ), featureSource->sourceCrs() ) ); if ( !sink ) throw QgsProcessingException( invalidSinkError( parameters, QStringLiteral( "OUTPUT" ) ) ); // first build up a list of clip geometries QVector< QgsGeometry > clipGeoms; QgsFeatureIterator it = maskSource->getFeatures( QgsFeatureRequest().setSubsetOfAttributes( QList< int >() ).setDestinationCrs( featureSource->sourceCrs(), context.transformContext() ) ); QgsFeature f; while ( it.nextFeature( f ) ) { if ( f.hasGeometry() ) clipGeoms << f.geometry(); } QVariantMap outputs; outputs.insert( QStringLiteral( "OUTPUT" ), dest ); if ( clipGeoms.isEmpty() ) return outputs; // are we clipping against a single feature? if so, we can show finer progress reports bool singleClipFeature = false; QgsGeometry combinedClipGeom; if ( clipGeoms.length() > 1 ) { combinedClipGeom = QgsGeometry::unaryUnion( clipGeoms ); if ( combinedClipGeom.isEmpty() ) { throw QgsProcessingException( QObject::tr( "Could not create the combined clip geometry: %1" ).arg( combinedClipGeom.lastError() ) ); } singleClipFeature = false; } else { combinedClipGeom = clipGeoms.at( 0 ); singleClipFeature = true; } // use prepared geometries for faster intersection tests std::unique_ptr< QgsGeometryEngine > engine( QgsGeometry::createGeometryEngine( combinedClipGeom.constGet() ) ); engine->prepareGeometry(); QgsFeatureIds testedFeatureIds; int i = -1; Q_FOREACH ( const QgsGeometry &clipGeom, clipGeoms ) { i++; if ( feedback->isCanceled() ) { break; } QgsFeatureIterator inputIt = featureSource->getFeatures( QgsFeatureRequest().setFilterRect( clipGeom.boundingBox() ) ); QgsFeatureList inputFeatures; QgsFeature f; while ( inputIt.nextFeature( f ) ) inputFeatures << f; if ( inputFeatures.isEmpty() ) continue; double step = 0; if ( singleClipFeature ) step = 100.0 / inputFeatures.length(); int current = 0; Q_FOREACH ( const QgsFeature &inputFeature, inputFeatures ) { if ( feedback->isCanceled() ) { break; } if ( !inputFeature.hasGeometry() ) continue; if ( testedFeatureIds.contains( inputFeature.id() ) ) { // don't retest a feature we have already checked continue; } testedFeatureIds.insert( inputFeature.id() ); if ( !engine->intersects( inputFeature.geometry().constGet() ) ) continue; QgsGeometry newGeometry; if ( !engine->contains( inputFeature.geometry().constGet() ) ) { QgsGeometry currentGeometry = inputFeature.geometry(); newGeometry = combinedClipGeom.intersection( currentGeometry ); if ( newGeometry.wkbType() == QgsWkbTypes::Unknown || QgsWkbTypes::flatType( newGeometry.wkbType() ) == QgsWkbTypes::GeometryCollection ) { QgsGeometry intCom = inputFeature.geometry().combine( newGeometry ); QgsGeometry intSym = inputFeature.geometry().symDifference( newGeometry ); newGeometry = intCom.difference( intSym ); } } else { // clip geometry totally contains feature geometry, so no need to perform intersection newGeometry = inputFeature.geometry(); } if ( !QgsOverlayUtils::sanitizeIntersectionResult( newGeometry, sinkType ) ) continue; QgsFeature outputFeature; outputFeature.setGeometry( newGeometry ); outputFeature.setAttributes( inputFeature.attributes() ); sink->addFeature( outputFeature, QgsFeatureSink::FastInsert ); if ( singleClipFeature ) feedback->setProgress( current * step ); } if ( !singleClipFeature ) { // coarse progress report for multiple clip geometries feedback->setProgress( 100.0 * static_cast< double >( i ) / clipGeoms.length() ); } }