QgsCoordinateTransform* QgsCoordinateTransform::clone() const
{
QgsCoordinateTransform* tr = new QgsCoordinateTransform( sourceCrs(), destCRS() );
tr->setSourceDatumTransform( sourceDatumTransform() );
tr->setDestinationDatumTransform( destinationDatumTransform() );
tr->initialise();
return tr;
}
QgsFeature QgsTransformAlgorithm::processFeature( const QgsFeature &f, QgsProcessingContext &, QgsProcessingFeedback * )
{
QgsFeature feature = f;
if ( !mCreatedTransform )
{
mCreatedTransform = true;
mTransform = QgsCoordinateTransform( sourceCrs(), mDestCrs, mTransformContext );
}
if ( feature.hasGeometry() )
{
QgsGeometry g = feature.geometry();
if ( g.transform( mTransform ) == 0 )
{
feature.setGeometry( g );
}
else
{
feature.clearGeometry();
}
}
return feature;
}
QgsVectorLayer *QgsFeatureSource::materialize( const QgsFeatureRequest &request, QgsFeedback *feedback )
{
QgsWkbTypes::Type outWkbType = request.flags() & QgsFeatureRequest::NoGeometry ? QgsWkbTypes::NoGeometry : wkbType();
QgsCoordinateReferenceSystem crs = request.destinationCrs().isValid() ? request.destinationCrs() : sourceCrs();
QgsAttributeList requestedAttrs = request.subsetOfAttributes();
QgsFields outFields;
if ( request.flags() & QgsFeatureRequest::SubsetOfAttributes )
{
int i = 0;
const QgsFields sourceFields = fields();
for ( const QgsField &field : sourceFields )
{
if ( requestedAttrs.contains( i ) )
outFields.append( field );
i++;
}
}
else
{
outFields = fields();
}
std::unique_ptr< QgsVectorLayer > layer( QgsMemoryProviderUtils::createMemoryLayer(
sourceName(),
outFields,
outWkbType,
crs ) );
QgsFeature f;
QgsFeatureIterator it = getFeatures( request );
int fieldCount = fields().count();
while ( it.nextFeature( f ) )
{
if ( feedback && feedback->isCanceled() )
break;
if ( request.flags() & QgsFeatureRequest::SubsetOfAttributes )
{
// remove unused attributes
QgsAttributes attrs;
for ( int i = 0; i < fieldCount; ++i )
{
if ( requestedAttrs.contains( i ) )
{
attrs.append( f.attributes().at( i ) );
}
}
f.setAttributes( attrs );
}
layer->dataProvider()->addFeature( f, QgsFeatureSink::FastInsert );
}
return layer.release();
}
