/*
* 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;
}
}
}