Parameters:: geom0 - geom0 the first geometry argument; geom1 - geom1 the second geometry argument; opCode - opCode the code for the desired overlay operation

Returns:: the result of the overlay operation

Throws:: TopologyException - TopologyException if a robustness problem is encountered

public static boolean isResultOfOp(Label label, int opCode)

Tests whether a point with a given topological Label relative to two geometries is contained in the result of overlaying the geometries using a given overlay operation.

The method handles arguments of Location.NONE correctly

Parameters:: label - label the topological label of the point; opCode - opCode the code for the overlay operation to test

Returns:: true if the label locations correspond to the overlayOpCode

public static boolean isResultOfOp(int loc0, int loc1, int overlayOpCode)

Tests whether a point with given Locations relative to two geometries is contained in the result of overlaying the geometries using a given overlay operation.

The method handles arguments of Location.NONE correctly

Parameters:: loc0 - loc0 the code for the location in the first geometry; loc1 - loc1 the code for the location in the second geometry; overlayOpCode - overlayOpCode the code for the overlay operation to test

Returns:: true if the locations correspond to the overlayOpCode

public Geometry getResultGeometry(int overlayOpCode)

Gets the result of the overlay for a given overlay operation.

Note: this method can be called once only.

Parameters:: overlayOpCode - overlayOpCode the overlay operation to perform

Returns:: the compute result geometry

Throws:: TopologyException - TopologyException if a robustness problem is encountered

public PlanarGraph getGraph()

Gets the graph constructed to compute the overlay.

Returns:: the overlay graph

protected void insertUniqueEdge(Edge e)

Insert an edge from one of the noded input graphs. Checks edges that are inserted to see if an identical edge already exists. If so, the edge is not inserted, but its label is merged with the existing edge.

public boolean isCoveredByLA(Coordinate coord)

Tests if a point node should be included in the result or not.

Parameters:: coord - coord the point coordinate

Returns:: true if the coordinate point is covered by a result Line or Area geometry

public boolean isCoveredByA(Coordinate coord)

Tests if an L edge should be included in the result or not.

Parameters:: coord - coord the point coordinate

Returns:: true if the coordinate point is covered by a result Area geometry

public static Geometry createEmptyResult(int overlayOpCode, Geometry a, Geometry b, GeometryFactory geomFact)

Creates an empty result geometry of the appropriate dimension, based on the given overlay operation and the dimensions of the inputs. The created geometry is always an atomic geometry, not a collection.

The empty result is constructed using the following rules:

INTERSECTION - result has the dimension of the lowest input dimension
UNION - result has the dimension of the highest input dimension
DIFFERENCE - result has the dimension of the left-hand input
SYMDIFFERENCE - result has the dimension of the highest input dimension (since the symmetric Difference is the union of the differences).

Parameters:: overlayOpCode - overlayOpCode the code for the overlay operation being performed; a - a an input geometry; b - b an input geometry; geomFact - geomFact the geometry factory being used for the operation

Returns:: an empty atomic geometry of the appropriate dimension