/*
* Copyright (c) 2016 Vivid Solutions.
*
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* and Eclipse Distribution License v. 1.0 which accompanies this distribution.
* The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
* and the Eclipse Distribution License is available at
*
* http://www.eclipse.org/org/documents/edl-v10.php.
*/
package org.locationtech.jts.algorithm;
import java.util.Iterator;
import org.locationtech.jts.geom.Coordinate;
import org.locationtech.jts.geom.Geometry;
import org.locationtech.jts.geom.GeometryCollection;
import org.locationtech.jts.geom.GeometryCollectionIterator;
import org.locationtech.jts.geom.LineString;
import org.locationtech.jts.geom.LinearRing;
import org.locationtech.jts.geom.Location;
import org.locationtech.jts.geom.MultiLineString;
import org.locationtech.jts.geom.MultiPolygon;
import org.locationtech.jts.geom.Point;
import org.locationtech.jts.geom.Polygon;
/**
* Computes the topological ({@link Location})
* of a single point to a {@link Geometry}.
* A {@link BoundaryNodeRule} may be specified
* to control the evaluation of whether the point lies on the boundary or not
* The default rule is to use the the <i>SFS Boundary Determination Rule</i>
* <p>
* Notes:
* <ul>
* <li>{@link LinearRing}s do not enclose any area - points inside the ring are still in the EXTERIOR of the ring.
* </ul>
* Instances of this class are not reentrant.
*
* @version 1.7
*/
public class PointLocator
{
// default is to use OGC SFS rule
private BoundaryNodeRule boundaryRule =
//BoundaryNodeRule.ENDPOINT_BOUNDARY_RULE;
BoundaryNodeRule.OGC_SFS_BOUNDARY_RULE;
private boolean isIn; // true if the point lies in or on any Geometry element
private int numBoundaries; // the number of sub-elements whose boundaries the point lies in
public PointLocator() {
}
public PointLocator(BoundaryNodeRule boundaryRule)
{
if (boundaryRule == null)
throw new IllegalArgumentException("Rule must be non-null");
this.boundaryRule = boundaryRule;
}
/**
* Convenience method to test a point for intersection with
* a Geometry
* @param p the coordinate to test
* @param geom the Geometry to test
* @return <code>true</code> if the point is in the interior or boundary of the Geometry
*/
public boolean intersects(Coordinate p, Geometry geom)
{
return locate(p, geom) != Location.EXTERIOR;
}
/**
* Computes the topological relationship ({@link Location}) of a single point
* to a Geometry.
* It handles both single-element
* and multi-element Geometries.
* The algorithm for multi-part Geometries
* takes into account the SFS Boundary Determination Rule.
*
* @return the {@link Location} of the point relative to the input Geometry
*/
public int locate(Coordinate p, Geometry geom)
{
if (geom.isEmpty()) return Location.EXTERIOR;
if (geom instanceof LineString) {
return locate(p, (LineString) geom);
}
else if (geom instanceof Polygon) {
return locate(p, (Polygon) geom);
}
isIn = false;
numBoundaries = 0;
computeLocation(p, geom);
if (boundaryRule.isInBoundary(numBoundaries))
return Location.BOUNDARY;
if (numBoundaries > 0 || isIn)
return Location.INTERIOR;
return Location.EXTERIOR;
}
private void computeLocation(Coordinate p, Geometry geom)
{
if (geom instanceof Point) {
updateLocationInfo(locate(p, (Point) geom));
}
if (geom instanceof LineString) {
updateLocationInfo(locate(p, (LineString) geom));
}
else if (geom instanceof Polygon) {
updateLocationInfo(locate(p, (Polygon) geom));
}
else if (geom instanceof MultiLineString) {
MultiLineString ml = (MultiLineString) geom;
for (int i = 0; i < ml.getNumGeometries(); i++) {
LineString l = (LineString) ml.getGeometryN(i);
updateLocationInfo(locate(p, l));
}
}
else if (geom instanceof MultiPolygon) {
MultiPolygon mpoly = (MultiPolygon) geom;
for (int i = 0; i < mpoly.getNumGeometries(); i++) {
Polygon poly = (Polygon) mpoly.getGeometryN(i);
updateLocationInfo(locate(p, poly));
}
}
else if (geom instanceof GeometryCollection) {
Iterator geomi = new GeometryCollectionIterator((GeometryCollection) geom);
while (geomi.hasNext()) {
Geometry g2 = (Geometry) geomi.next();
if (g2 != geom)
computeLocation(p, g2);
}
}
}
private void updateLocationInfo(int loc)
{
if (loc == Location.INTERIOR) isIn = true;
if (loc == Location.BOUNDARY) numBoundaries++;
}
private int locate(Coordinate p, Point pt)
{
// no point in doing envelope test, since equality test is just as fast
Coordinate ptCoord = pt.getCoordinate();
if (ptCoord.equals2D(p))
return Location.INTERIOR;
return Location.EXTERIOR;
}
private int locate(Coordinate p, LineString l)
{
// bounding-box check
if (! l.getEnvelopeInternal().intersects(p)) return Location.EXTERIOR;
Coordinate[] pt = l.getCoordinates();
if (! l.isClosed()) {
if (p.equals(pt[0])
|| p.equals(pt[pt.length - 1]) ) {
return Location.BOUNDARY;
}
}
if (CGAlgorithms.isOnLine(p, pt))
return Location.INTERIOR;
return Location.EXTERIOR;
}
private int locateInPolygonRing(Coordinate p, LinearRing ring)
{
// bounding-box check
if (! ring.getEnvelopeInternal().intersects(p)) return Location.EXTERIOR;
return CGAlgorithms.locatePointInRing(p, ring.getCoordinates());
}
private int locate(Coordinate p, Polygon poly)
{
if (poly.isEmpty()) return Location.EXTERIOR;
LinearRing shell = (LinearRing) poly.getExteriorRing();
int shellLoc = locateInPolygonRing(p, shell);
if (shellLoc == Location.EXTERIOR) return Location.EXTERIOR;
if (shellLoc == Location.BOUNDARY) return Location.BOUNDARY;
// now test if the point lies in or on the holes
for (int i = 0; i < poly.getNumInteriorRing(); i++) {
LinearRing hole = (LinearRing) poly.getInteriorRingN(i);
int holeLoc = locateInPolygonRing(p, hole);
if (holeLoc == Location.INTERIOR) return Location.EXTERIOR;
if (holeLoc == Location.BOUNDARY) return Location.BOUNDARY;
}
return Location.INTERIOR;
}
}