bool operator==( const QgsGeometry &g1, const QgsGeometry &g2 )
{
if ( g1.isNull() && g2.isNull() )
return true;
else
return g1.isGeosEqual( g2 );
}
QVariantMap QgsSplitWithLinesAlgorithm::processAlgorithm( const QVariantMap ¶meters, QgsProcessingContext &context, QgsProcessingFeedback *feedback )
{
std::unique_ptr< QgsFeatureSource > source( parameterAsSource( parameters, QStringLiteral( "INPUT" ), context ) );
if ( !source )
throw QgsProcessingException( invalidSourceError( parameters, QStringLiteral( "INPUT" ) ) );
std::unique_ptr< QgsFeatureSource > linesSource( parameterAsSource( parameters, QStringLiteral( "LINES" ), context ) );
if ( !linesSource )
throw QgsProcessingException( invalidSourceError( parameters, QStringLiteral( "LINES" ) ) );
bool sameLayer = parameters.value( QStringLiteral( "INPUT" ) ) == parameters.value( QStringLiteral( "LINES" ) );
QString dest;
std::unique_ptr< QgsFeatureSink > sink( parameterAsSink( parameters, QStringLiteral( "OUTPUT" ), context, dest, source->fields(),
QgsWkbTypes::multiType( source->wkbType() ), source->sourceCrs() ) );
if ( !sink )
throw QgsProcessingException( invalidSinkError( parameters, QStringLiteral( "OUTPUT" ) ) );
QgsSpatialIndex spatialIndex;
QMap< QgsFeatureId, QgsGeometry > splitGeoms;
QgsFeatureRequest request;
request.setSubsetOfAttributes( QgsAttributeList() );
request.setDestinationCrs( source->sourceCrs(), context.transformContext() );
QgsFeatureIterator splitLines = linesSource->getFeatures( request );
QgsFeature aSplitFeature;
while ( splitLines.nextFeature( aSplitFeature ) )
{
if ( feedback->isCanceled() )
{
break;
}
splitGeoms.insert( aSplitFeature.id(), aSplitFeature.geometry() );
spatialIndex.addFeature( aSplitFeature );
}
QgsFeature outFeat;
QgsFeatureIterator features = source->getFeatures();
double step = source->featureCount() > 0 ? 100.0 / source->featureCount() : 1;
int i = 0;
QgsFeature inFeatureA;
while ( features.nextFeature( inFeatureA ) )
{
i++;
if ( feedback->isCanceled() )
{
break;
}
if ( !inFeatureA.hasGeometry() )
{
sink->addFeature( inFeatureA, QgsFeatureSink::FastInsert );
continue;
}
QgsGeometry inGeom = inFeatureA.geometry();
outFeat.setAttributes( inFeatureA.attributes() );
QVector< QgsGeometry > inGeoms = inGeom.asGeometryCollection();
const QgsFeatureIds lines = spatialIndex.intersects( inGeom.boundingBox() ).toSet();
if ( !lines.empty() ) // has intersection of bounding boxes
{
QVector< QgsGeometry > splittingLines;
// use prepared geometries for faster intersection tests
std::unique_ptr< QgsGeometryEngine > engine;
for ( QgsFeatureId line : lines )
{
// check if trying to self-intersect
if ( sameLayer && inFeatureA.id() == line )
continue;
QgsGeometry splitGeom = splitGeoms.value( line );
if ( !engine )
{
engine.reset( QgsGeometry::createGeometryEngine( inGeom.constGet() ) );
engine->prepareGeometry();
}
if ( engine->intersects( splitGeom.constGet() ) )
{
QVector< QgsGeometry > splitGeomParts = splitGeom.asGeometryCollection();
splittingLines.append( splitGeomParts );
}
}
if ( !splittingLines.empty() )
{
for ( const QgsGeometry &splitGeom : qgis::as_const( splittingLines ) )
{
QVector<QgsPointXY> splitterPList;
QVector< QgsGeometry > outGeoms;
// use prepared geometries for faster intersection tests
std::unique_ptr< QgsGeometryEngine > splitGeomEngine( QgsGeometry::createGeometryEngine( splitGeom.constGet() ) );
splitGeomEngine->prepareGeometry();
while ( !inGeoms.empty() )
{
if ( feedback->isCanceled() )
{
break;
}
QgsGeometry inGeom = inGeoms.takeFirst();
if ( !inGeom )
continue;
if ( splitGeomEngine->intersects( inGeom.constGet() ) )
{
QgsGeometry before = inGeom;
if ( splitterPList.empty() )
{
const QgsCoordinateSequence sequence = splitGeom.constGet()->coordinateSequence();
for ( const QgsRingSequence &part : sequence )
{
for ( const QgsPointSequence &ring : part )
{
for ( const QgsPoint &pt : ring )
{
splitterPList << QgsPointXY( pt );
}
}
}
}
QVector< QgsGeometry > newGeometries;
QVector<QgsPointXY> topologyTestPoints;
QgsGeometry::OperationResult result = inGeom.splitGeometry( splitterPList, newGeometries, false, topologyTestPoints );
// splitGeometry: If there are several intersections
// between geometry and splitLine, only the first one is considered.
if ( result == QgsGeometry::Success ) // split occurred
{
if ( inGeom.isGeosEqual( before ) )
{
// bug in splitGeometry: sometimes it returns 0 but
// the geometry is unchanged
outGeoms.append( inGeom );
}
else
{
inGeoms.append( inGeom );
inGeoms.append( newGeometries );
}
}
else
{
outGeoms.append( inGeom );
}
}
else
{
outGeoms.append( inGeom );
}
}
inGeoms = outGeoms;
}
}
}
QVector< QgsGeometry > parts;
for ( const QgsGeometry &aGeom : qgis::as_const( inGeoms ) )
{
if ( feedback->isCanceled() )
{
break;
}
bool passed = true;
if ( QgsWkbTypes::geometryType( aGeom.wkbType() ) == QgsWkbTypes::LineGeometry )
{
int numPoints = aGeom.constGet()->nCoordinates();
if ( numPoints <= 2 )
{
if ( numPoints == 2 )
passed = !static_cast< const QgsCurve * >( aGeom.constGet() )->isClosed(); // tests if vertex 0 = vertex 1
else
passed = false; // sometimes splitting results in lines of zero length
}
}
if ( passed )
parts.append( aGeom );
}
for ( const QgsGeometry &g : parts )
{
outFeat.setGeometry( g );
sink->addFeature( outFeat, QgsFeatureSink::FastInsert );
}
feedback->setProgress( i * step );
}
QVariantMap outputs;
outputs.insert( QStringLiteral( "OUTPUT" ), dest );
return outputs;
}