QgsFeatureList QgsConvexHullAlgorithm::processFeature( const QgsFeature &feature, QgsProcessingContext &, QgsProcessingFeedback *feedback )
{
QgsFeature f = feature;
if ( f.hasGeometry() )
{
QgsGeometry outputGeometry;
if ( QgsWkbTypes::flatType( f.geometry().wkbType() ) == QgsWkbTypes::Point )
{
feedback->reportError( QObject::tr( "Cannot calculate convex hull for a single Point feature (try 'Minimum bounding geometry' algorithm instead)." ) );
f.clearGeometry();
}
else
{
outputGeometry = f.geometry().convexHull();
if ( outputGeometry.isNull() )
feedback->reportError( outputGeometry.lastError() );
f.setGeometry( outputGeometry );
}
if ( !outputGeometry.isNull() )
{
QgsAttributes attrs = f.attributes();
attrs << outputGeometry.constGet()->area()
<< outputGeometry.constGet()->perimeter();
f.setAttributes( attrs );
}
else
{
QgsAttributes attrs = f.attributes();
attrs << QVariant()
<< QVariant();
f.setAttributes( attrs );
}
}
return QgsFeatureList() << f;
}
QgsFeature QgsConvexHullAlgorithm::processFeature( const QgsFeature &feature, QgsProcessingContext &, QgsProcessingFeedback *feedback )
{
QgsFeature f = feature;
if ( f.hasGeometry() )
{
QgsGeometry outputGeometry = f.geometry().convexHull();
if ( !outputGeometry )
feedback->reportError( outputGeometry.lastError() );
f.setGeometry( outputGeometry );
if ( outputGeometry )
{
QgsAttributes attrs = f.attributes();
attrs << outputGeometry.constGet()->area()
<< outputGeometry.constGet()->perimeter();
f.setAttributes( attrs );
}
else
{
QgsAttributes attrs = f.attributes();
attrs << QVariant()
<< QVariant();
f.setAttributes( attrs );
}
}
return f;
}
void QgsMapToolOffsetCurve::updateGeometryAndRubberBand( double offset )
{
if ( !mRubberBand || mOriginalGeometry.isNull() )
{
return;
}
if ( !mLayer )
{
return;
}
QgsGeometry offsetGeom;
QgsSettings s;
QgsGeometry::JoinStyle joinStyle = s.enumValue( QStringLiteral( "/qgis/digitizing/offset_join_style" ), QgsGeometry::JoinStyleRound );
int quadSegments = s.value( QStringLiteral( "/qgis/digitizing/offset_quad_seg" ), 8 ).toInt();
double miterLimit = s.value( QStringLiteral( "/qgis/digitizing/offset_miter_limit" ), 5.0 ).toDouble();
QgsGeometry::EndCapStyle capStyle = s.enumValue( QStringLiteral( "/qgis/digitizing/offset_cap_style" ), QgsGeometry::CapRound );
if ( QgsWkbTypes::geometryType( mOriginalGeometry.wkbType() ) == QgsWkbTypes::LineGeometry )
{
offsetGeom = mManipulatedGeometry.offsetCurve( offset, quadSegments, joinStyle, miterLimit );
}
else
{
offsetGeom = mManipulatedGeometry.buffer( offset, quadSegments, capStyle, joinStyle, miterLimit );
}
if ( !offsetGeom )
{
deleteRubberBandAndGeometry();
deleteUserInputWidget();
mLayer = nullptr;
mGeometryModified = false;
emit messageDiscarded();
emit messageEmitted( tr( "Creating offset geometry failed: %1" ).arg( offsetGeom.lastError() ), Qgis::Critical );
}
else
{
mModifiedGeometry = offsetGeom;
mRubberBand->setToGeometry( mModifiedGeometry, mLayer );
}
}
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() );
}
}
//! Makes sure that what came out from difference of two geometries is good to be used in the output
static bool sanitizeDifferenceResult( QgsGeometry &geom )
{
if ( geom.isNull() )
{
// TODO: not sure if this ever happens - if it does, that means GEOS failed badly - would be good to have a test for such situation
throw QgsProcessingException( QStringLiteral( "%1\n\n%2" ).arg( QObject::tr( "GEOS geoprocessing error: difference failed." ), geom.lastError() ) );
}
// if geomB covers the whole source geometry, we get an empty geometry collection
if ( geom.isEmpty() )
return false;
// some data providers are picky about the geometries we pass to them: we can't add single-part geometries
// when we promised multi-part geometries, so ensure we have the right type
geom.convertToMultiType();
return true;
}
bool QgsOverlayUtils::sanitizeIntersectionResult( QgsGeometry &geom, QgsWkbTypes::GeometryType geometryType )
{
if ( geom.isNull() )
{
// TODO: not sure if this ever happens - if it does, that means GEOS failed badly - would be good to have a test for such situation
throw QgsProcessingException( QStringLiteral( "%1\n\n%2" ).arg( QObject::tr( "GEOS geoprocessing error: intersection failed." ), geom.lastError() ) );
}
// Intersection of geometries may give use also geometries we do not want in our results.
// For example, two square polygons touching at the corner have a point as the intersection, but no area.
// In other cases we may get a mixture of geometries in the output - we want to keep only the expected types.
if ( QgsWkbTypes::flatType( geom.wkbType() ) == QgsWkbTypes::GeometryCollection )
{
// try to filter out irrelevant parts with different geometry type than what we want
geom.convertGeometryCollectionToSubclass( geometryType );
if ( geom.isEmpty() )
return false;
}
if ( QgsWkbTypes::geometryType( geom.wkbType() ) != geometryType )
{
// we can't make use of this resulting geometry
return false;
}
// some data providers are picky about the geometries we pass to them: we can't add single-part geometries
// when we promised multi-part geometries, so ensure we have the right type
geom.convertToMultiType();
return true;
}
