/* * The JTS Topology Suite is a collection of Java classes that * implement the fundamental operations required to validate a given * geo-spatial data set to a known topological specification. * * Copyright (C) 2001 Vivid Solutions * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * * For more information, contact: * * Vivid Solutions * Suite #1A * 2328 Government Street * Victoria BC V8T 5G5 * Canada * * (250)385-6040 * www.vividsolutions.com */ package com.vividsolutions.jts.operation.valid; import java.util.*; import com.vividsolutions.jts.algorithm.*; import com.vividsolutions.jts.geom.*; import com.vividsolutions.jts.geomgraph.*; import com.vividsolutions.jts.index.sweepline.*; import com.vividsolutions.jts.util.*; /** * Tests whether any of a set of {@link LinearRing}s are * nested inside another ring in the set, using a {@link SweepLineIndex} * index to speed up the comparisons. * * @version 1.7 */ public class SweeplineNestedRingTester { private GeometryGraph graph; // used to find non-node vertices private List rings = new ArrayList(); //private Envelope totalEnv = new Envelope(); private SweepLineIndex sweepLine; private Coordinate nestedPt = null; public SweeplineNestedRingTester(GeometryGraph graph) { this.graph = graph; } public Coordinate getNestedPoint() { return nestedPt; } public void add(LinearRing ring) { rings.add(ring); } public boolean isNonNested() { buildIndex(); OverlapAction action = new OverlapAction(); sweepLine.computeOverlaps(action); return action.isNonNested; } private void buildIndex() { sweepLine = new SweepLineIndex(); for (int i = 0; i < rings.size(); i++) { LinearRing ring = (LinearRing) rings.get(i); Envelope env = ring.getEnvelopeInternal(); SweepLineInterval sweepInt = new SweepLineInterval(env.getMinX(), env.getMaxX(), ring); sweepLine.add(sweepInt); } } private boolean isInside(LinearRing innerRing, LinearRing searchRing) { Coordinate[] innerRingPts = innerRing.getCoordinates(); Coordinate[] searchRingPts = searchRing.getCoordinates(); if (! innerRing.getEnvelopeInternal().intersects(searchRing.getEnvelopeInternal())) return false; Coordinate innerRingPt = IsValidOp.findPtNotNode(innerRingPts, searchRing, graph); Assert.isTrue(innerRingPt != null, "Unable to find a ring point not a node of the search ring"); boolean isInside = CGAlgorithms.isPointInRing(innerRingPt, searchRingPts); if (isInside) { nestedPt = innerRingPt; return true; } return false; } class OverlapAction implements SweepLineOverlapAction { boolean isNonNested = true; public void overlap(SweepLineInterval s0, SweepLineInterval s1) { LinearRing innerRing = (LinearRing) s0.getItem(); LinearRing searchRing = (LinearRing) s1.getItem(); if (innerRing == searchRing) return; if (isInside(innerRing, searchRing)) isNonNested = false; } } }