package com.vividsolutions.jts.operation.union;
import com.vividsolutions.jts.algorithm.*;
import com.vividsolutions.jts.geom.*;
import com.vividsolutions.jts.geom.util.*;
import java.util.*;
/**
* Computes the union of a {@link Puntal} geometry with
* another arbitrary {@link Geometry}.
* Does not copy any component geometries.
*
* @author mbdavis
*
*/
public class PointGeometryUnion
{
public static Geometry union(Puntal pointGeom, Geometry otherGeom)
{
PointGeometryUnion unioner = new PointGeometryUnion(pointGeom, otherGeom);
return unioner.union();
}
private Geometry pointGeom;
private Geometry otherGeom;
private GeometryFactory geomFact;
public PointGeometryUnion(Puntal pointGeom, Geometry otherGeom)
{
this.pointGeom = (Geometry) pointGeom;
this.otherGeom = otherGeom;
geomFact = otherGeom.getFactory();
}
public Geometry union()
{
PointLocator locater = new PointLocator();
// use a set to eliminate duplicates, as required for union
Set exteriorCoords = new TreeSet();
for (int i =0 ; i < pointGeom.getNumGeometries(); i++) {
Point point = (Point) pointGeom.getGeometryN(i);
Coordinate coord = point.getCoordinate();
int loc = locater.locate(coord, otherGeom);
if (loc == Location.EXTERIOR)
exteriorCoords.add(coord);
}
// if no points are in exterior, return the other geom
if (exteriorCoords.size() == 0)
return otherGeom;
// make a puntal geometry of appropriate size
Geometry ptComp = null;
Coordinate[] coords = CoordinateArrays.toCoordinateArray(exteriorCoords);
if (coords.length == 1) {
ptComp = geomFact.createPoint(coords[0]);
}
else {
ptComp = geomFact.createMultiPoint(coords);
}
// add point component to the other geometry
return GeometryCombiner.combine(ptComp, otherGeom);
}
}