/*
* 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.jtslab.clean;
import java.util.ArrayList;
import java.util.List;
import org.locationtech.jts.geom.Geometry;
import org.locationtech.jts.geom.GeometryFactory;
import org.locationtech.jts.geom.LinearRing;
import org.locationtech.jts.geom.Polygon;
import org.locationtech.jts.geom.util.GeometryMapper;
import org.locationtech.jts.geom.util.GeometryMapper.MapOp;
/**
* Removes holes which match a given predicate.
*
* @author Martin Davis
*
*/
public class HoleRemover {
public interface Predicate {
boolean value(Geometry geom);
}
private Geometry geom;
private Predicate isRemoved;
/**
* Creates a new hole remover instance.
*
* @param geom the geometry to process
*/
public HoleRemover(Geometry geom, Predicate isRemoved) {
this.geom = geom;
this.isRemoved = isRemoved;
}
/**
* Gets the cleaned geometry.
*
* @return the geometry with matched holes removed.
*/
public Geometry getResult()
{
return GeometryMapper.map(geom, new HoleRemoverMapOp());
}
private class HoleRemoverMapOp implements MapOp {
public Geometry map(Geometry geom) {
if (geom instanceof Polygon)
return PolygonHoleRemover.clean((Polygon) geom, isRemoved);
return geom;
}
}
private static class PolygonHoleRemover {
public static Polygon clean(Polygon poly, Predicate isRemoved) {
PolygonHoleRemover pihr = new PolygonHoleRemover(poly, isRemoved);
return pihr.getResult();
}
private Polygon poly;
private Predicate isRemoved;
public PolygonHoleRemover(Polygon poly, Predicate isRemoved) {
this.poly = poly;
this.isRemoved = isRemoved;
}
public Polygon getResult()
{
GeometryFactory gf = poly.getFactory();
Polygon shell = gf.createPolygon((LinearRing) poly.getExteriorRing());
List holes = new ArrayList();
for (int i = 0; i < poly.getNumInteriorRing(); i++) {
LinearRing hole = (LinearRing) poly.getInteriorRingN(i);
if (! isRemoved.value(hole)) {
holes.add(hole);
}
}
// all holes valid, so return original
if (holes.size() == poly.getNumInteriorRing())
return poly;
// return new polygon with covered holes only
Polygon result = gf.createPolygon((LinearRing) poly.getExteriorRing(),
GeometryFactory.toLinearRingArray(holes));
return result;
}
}
}