com.vividsolutions.jts.operation.valid.IndexedNestedRingTester Maven / Gradle / Ivy
/*
* 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.SpatialIndex;
import com.vividsolutions.jts.index.strtree.STRtree;
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 spatial
* index to speed up the comparisons.
*
* @version 1.7
*/
public class IndexedNestedRingTester
{
private GeometryGraph graph; // used to find non-node vertices
private List rings = new ArrayList();
private Envelope totalEnv = new Envelope();
private SpatialIndex index;
private Coordinate nestedPt;
public IndexedNestedRingTester(GeometryGraph graph)
{
this.graph = graph;
}
public Coordinate getNestedPoint() { return nestedPt; }
public void add(LinearRing ring)
{
rings.add(ring);
totalEnv.expandToInclude(ring.getEnvelopeInternal());
}
public boolean isNonNested()
{
buildIndex();
for (int i = 0; i < rings.size(); i++) {
LinearRing innerRing = (LinearRing) rings.get(i);
Coordinate[] innerRingPts = innerRing.getCoordinates();
List results = index.query(innerRing.getEnvelopeInternal());
//System.out.println(results.size());
for (int j = 0; j < results.size(); j++) {
LinearRing searchRing = (LinearRing) results.get(j);
Coordinate[] searchRingPts = searchRing.getCoordinates();
if (innerRing == searchRing)
continue;
if (! innerRing.getEnvelopeInternal().intersects(searchRing.getEnvelopeInternal()))
continue;
Coordinate innerRingPt = IsValidOp.findPtNotNode(innerRingPts, searchRing, graph);
/**
* If no non-node pts can be found, this means
* that the searchRing touches ALL of the innerRing vertices.
* This indicates an invalid polygon, since either
* the two holes create a disconnected interior,
* or they touch in an infinite number of points
* (i.e. along a line segment).
* Both of these cases are caught by other tests,
* so it is safe to simply skip this situation here.
*/
if (innerRingPt == null)
continue;
boolean isInside = CGAlgorithms.isPointInRing(innerRingPt, searchRingPts);
if (isInside) {
nestedPt = innerRingPt;
return false;
}
}
}
return true;
}
private void buildIndex()
{
index = new STRtree();
for (int i = 0; i < rings.size(); i++) {
LinearRing ring = (LinearRing) rings.get(i);
Envelope env = ring.getEnvelopeInternal();
index.insert(env, ring);
}
}
}