private void ComputeOverlay(SpatialFunction opCode)
{
// copy points from input Geometries.
// This ensures that any Point geometries
// in the input are considered for inclusion in the result set
CopyPoints(0);
CopyPoints(1);
// node the input Geometries
arg[0].ComputeSelfNodes(lineIntersector, false);
arg[1].ComputeSelfNodes(lineIntersector, false);
// compute intersections between edges of the two input geometries
arg[0].ComputeEdgeIntersections(arg[1], lineIntersector, true);
IList<Edge> baseSplitEdges = new List<Edge>();
arg[0].ComputeSplitEdges(baseSplitEdges);
arg[1].ComputeSplitEdges(baseSplitEdges);
// add the noded edges to this result graph
InsertUniqueEdges(baseSplitEdges);
ComputeLabelsFromDepths();
ReplaceCollapsedEdges();
if (!NodingValidatorDisabled)
{
/*
* Check that the noding completed correctly.
*
* This test is slow, but necessary in order to catch robustness failure
* situations.
* If an exception is thrown because of a noding failure,
* then snapping will be performed, which will hopefully avoid the problem.
* In the future hopefully a faster check can be developed.
*
*/
var nv = new EdgeNodingValidator(_edgeList.Edges);
nv.CheckValid();
}
_graph.AddEdges(_edgeList.Edges);
ComputeLabelling();
LabelIncompleteNodes();
/*
* The ordering of building the result Geometries is important.
* Areas must be built before lines, which must be built before points.
* This is so that lines which are covered by areas are not included
* explicitly, and similarly for points.
*/
FindResultAreaEdges(opCode);
CancelDuplicateResultEdges();
var polyBuilder = new PolygonBuilder(_geomFact);
polyBuilder.Add(_graph);
_resultPolyList = polyBuilder.Polygons;
var lineBuilder = new LineBuilder(this, _geomFact, _ptLocator);
_resultLineList = lineBuilder.Build(opCode);
var pointBuilder = new PointBuilder(this, _geomFact, _ptLocator);
_resultPointList = pointBuilder.Build(opCode);
// gather the results from all calculations into a single Geometry for the result set
_resultGeom = ComputeGeometry(_resultPointList, _resultLineList, _resultPolyList, opCode);
}
///<summary>
/// Checks whether the supplied <see cref="Edge"/>s are correctly noded.
///</summary>
/// <param name="edges">an enumeration of Edges.</param>
/// <exception cref="TopologyException">If the SegmentStrings are not correctly noded</exception>
public static void CheckValid(IEnumerable<Edge> edges)
{
EdgeNodingValidator validator = new EdgeNodingValidator(edges);
validator.CheckValid();
}
/// <summary>
/// Checks whether the supplied <see cref="Edge"/>s are correctly noded.
/// </summary>
/// <param name="edges">an enumeration of Edges.</param>
/// <exception cref="TopologyException">If the SegmentStrings are not correctly noded</exception>
public static void CheckValid(IEnumerable <Edge> edges)
{
var validator = new EdgeNodingValidator(edges);
validator.CheckValid();
}
