com.hazelcast.shaded.org.locationtech.jts.noding.SegmentExtractingNoder Maven / Gradle / Ivy
/*
* Copyright (c) 2019 Martin Davis.
*
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License 2.0
* and Eclipse Distribution License v. 1.0 which accompanies this distribution.
* The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v20.html
* and the Eclipse Distribution License is available at
*
* http://www.eclipse.org/org/documents/edl-v10.php.
*/
package com.hazelcast.shaded.org.locationtech.jts.noding;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import com.hazelcast.shaded.org.locationtech.jts.geom.Coordinate;
/**
* A noder which extracts all line segments
* as {@link SegmentString}s.
* This enables fast overlay of geometries which are known to be already fully noded.
* In particular, it provides fast union of polygonal and linear coverages.
* Unioning a noded set of lines is an effective way
* to perform line merging and line dissolving.
*
* No precision reduction is carried out.
* If that is required, another noder must be used (such as a snap-rounding noder),
* or the input must be precision-reduced beforehand.
*
* @author Martin Davis
*
*/
public class SegmentExtractingNoder implements Noder {
private List segList;
/**
* Creates a new segment-extracting noder.
*/
public SegmentExtractingNoder() {
}
@Override
public void computeNodes(Collection segStrings) {
segList = extractSegments(segStrings);
}
private static List extractSegments(Collection segStrings) {
List segList = new ArrayList();
for (SegmentString ss : segStrings) {
extractSegments( ss, segList );
}
return segList;
}
private static void extractSegments(SegmentString ss, List segList) {
for (int i = 0; i < ss.size() - 1; i++) {
Coordinate p0 = ss.getCoordinate(i);
Coordinate p1 = ss.getCoordinate(i + 1);
SegmentString seg = new BasicSegmentString(new Coordinate[] { p0, p1 }, ss.getData());
segList.add(seg);
}
}
@Override
public Collection getNodedSubstrings() {
return segList;
}
}