int QgsVectorLayerEditUtils::addTopologicalPoints( const QgsPointXY &p )
{
if ( !mLayer->isSpatial() )
return 1;
double segmentSearchEpsilon = mLayer->crs().isGeographic() ? 1e-12 : 1e-8;
//work with a tolerance because coordinate projection may introduce some rounding
double threshold = 0.0000001;
if ( mLayer->crs().mapUnits() == QgsUnitTypes::DistanceMeters )
{
threshold = 0.001;
}
else if ( mLayer->crs().mapUnits() == QgsUnitTypes::DistanceFeet )
{
threshold = 0.0001;
}
QgsRectangle searchRect( p.x() - threshold, p.y() - threshold,
p.x() + threshold, p.y() + threshold );
double sqrSnappingTolerance = threshold * threshold;
QgsFeature f;
QgsFeatureIterator fit = mLayer->getFeatures( QgsFeatureRequest()
.setFilterRect( searchRect )
.setFlags( QgsFeatureRequest::ExactIntersect )
.setSubsetOfAttributes( QgsAttributeList() ) );
QMap<QgsFeatureId, QgsGeometry> features;
QMap<QgsFeatureId, int> segments;
while ( fit.nextFeature( f ) )
{
int afterVertex;
QgsPointXY snappedPoint;
double sqrDistSegmentSnap = f.geometry().closestSegmentWithContext( p, snappedPoint, afterVertex, nullptr, segmentSearchEpsilon );
if ( sqrDistSegmentSnap < sqrSnappingTolerance )
{
segments[f.id()] = afterVertex;
features[f.id()] = f.geometry();
}
}
if ( segments.isEmpty() )
return 2;
for ( QMap<QgsFeatureId, int>::const_iterator it = segments.constBegin(); it != segments.constEnd(); ++it )
{
QgsFeatureId fid = it.key();
int segmentAfterVertex = it.value();
QgsGeometry geom = features[fid];
int atVertex, beforeVertex, afterVertex;
double sqrDistVertexSnap;
geom.closestVertex( p, atVertex, beforeVertex, afterVertex, sqrDistVertexSnap );
if ( sqrDistVertexSnap < sqrSnappingTolerance )
continue; // the vertex already exists - do not insert it
if ( !mLayer->insertVertex( p.x(), p.y(), fid, segmentAfterVertex ) )
{
QgsDebugMsg( "failed to insert topo point" );
}
}
return 0;
}
bool QgsPointDistanceRenderer::renderFeature( QgsFeature &feature, QgsRenderContext &context, int layer, bool selected, bool drawVertexMarker )
{
Q_UNUSED( drawVertexMarker );
Q_UNUSED( context );
Q_UNUSED( layer );
/*
* IMPORTANT: This algorithm is ported to Python in the processing "Points Displacement" algorithm.
* Please port any changes/improvements to that algorithm too!
*/
//check if there is already a point at that position
if ( !feature.hasGeometry() )
return false;
QgsMarkerSymbol *symbol = firstSymbolForFeature( feature, context );
//if the feature has no symbol (e.g., no matching rule in a rule-based renderer), skip it
if ( !symbol )
return false;
//point position in screen coords
QgsGeometry geom = feature.geometry();
QgsWkbTypes::Type geomType = geom.wkbType();
if ( QgsWkbTypes::flatType( geomType ) != QgsWkbTypes::Point )
{
//can only render point type
return false;
}
QString label;
if ( mDrawLabels )
{
label = getLabel( feature );
}
QgsCoordinateTransform xform = context.coordinateTransform();
QgsFeature transformedFeature = feature;
if ( xform.isValid() )
{
geom.transform( xform );
transformedFeature.setGeometry( geom );
}
double searchDistance = context.convertToMapUnits( mTolerance, mToleranceUnit, mToleranceMapUnitScale );
QgsPointXY point = transformedFeature.geometry().asPoint();
QList<QgsFeatureId> intersectList = mSpatialIndex->intersects( searchRect( point, searchDistance ) );
if ( intersectList.empty() )
{
mSpatialIndex->insertFeature( transformedFeature );
// create new group
ClusteredGroup newGroup;
newGroup << GroupedFeature( transformedFeature, symbol->clone(), selected, label );
mClusteredGroups.push_back( newGroup );
// add to group index
mGroupIndex.insert( transformedFeature.id(), mClusteredGroups.count() - 1 );
mGroupLocations.insert( transformedFeature.id(), point );
}
else
{
// find group with closest location to this point (may be more than one within search tolerance)
QgsFeatureId minDistFeatureId = intersectList.at( 0 );
double minDist = mGroupLocations.value( minDistFeatureId ).distance( point );
for ( int i = 1; i < intersectList.count(); ++i )
{
QgsFeatureId candidateId = intersectList.at( i );
double newDist = mGroupLocations.value( candidateId ).distance( point );
if ( newDist < minDist )
{
minDist = newDist;
minDistFeatureId = candidateId;
}
}
int groupIdx = mGroupIndex[ minDistFeatureId ];
ClusteredGroup &group = mClusteredGroups[groupIdx];
// calculate new centroid of group
QgsPointXY oldCenter = mGroupLocations.value( minDistFeatureId );
mGroupLocations[ minDistFeatureId ] = QgsPointXY( ( oldCenter.x() * group.size() + point.x() ) / ( group.size() + 1.0 ),
( oldCenter.y() * group.size() + point.y() ) / ( group.size() + 1.0 ) );
// add to a group
group << GroupedFeature( transformedFeature, symbol->clone(), selected, label );
// add to group index
mGroupIndex.insert( transformedFeature.id(), groupIdx );
}
return true;
}
void QgsPointDisplacementRenderer::createDisplacementGroups( QgsVectorLayer* vlayer, const QgsRectangle& viewExtent )
{
if ( !vlayer || ( vlayer->wkbType() != QGis::WKBPoint && vlayer->wkbType() != QGis::WKBPoint25D ) )
{
return;
}
mDisplacementGroups.clear();
mDisplacementIds.clear();
//use a spatial index to check if there is already a point at a position
QgsSpatialIndex spatialIndex;
//attributes
QgsAttributeList attList;
QList<QString> attributeStrings = usedAttributes();
QList<QString>::const_iterator attStringIt = attributeStrings.constBegin();
for ( ; attStringIt != attributeStrings.constEnd(); ++attStringIt )
{
attList.push_back( vlayer->fieldNameIndex( *attStringIt ) );
}
QgsFeature f;
QList<QgsFeatureId> intersectList;
vlayer->select( attList, viewExtent, true, false );
while ( vlayer->nextFeature( f ) )
{
intersectList.clear();
//check, if there is already a point at that position
if ( f.geometry() )
{
intersectList = spatialIndex.intersects( searchRect( f.geometry()->asPoint() ) );
if ( intersectList.empty() )
{
spatialIndex.insertFeature( f );
}
else
{
//go through all the displacement group maps and search an entry where the id equals the result of the spatial search
QgsFeatureId existingEntry = intersectList.at( 0 );
bool found = false;
QList< QMap<QgsFeatureId, QgsFeature> >::iterator it = mDisplacementGroups.begin();
for ( ; it != mDisplacementGroups.end(); ++it )
{
if ( it->size() > 0 && it->contains( existingEntry ) )
{
found = true;
QgsFeature feature;
it->insert( f.id(), f );
mDisplacementIds.insert( f.id() );
break;
}
}
if ( !found )//insert the already existing feature and the new one into a map
{
QMap<QgsFeatureId, QgsFeature> newMap;
QgsFeature existingFeature;
vlayer->featureAtId( existingEntry, existingFeature );
newMap.insert( existingEntry, existingFeature );
mDisplacementIds.insert( existingEntry );
newMap.insert( f.id(), f );
mDisplacementIds.insert( f.id() );
mDisplacementGroups.push_back( newMap );
}
}
}
}
//refresh the selection because the vector layer is going to step through all features now
vlayer->select( attList, viewExtent, true, false );
}
