com.vividsolutions.jts.operation.overlay.snap.SnapIfNeededOverlayOp Maven / Gradle / Ivy
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/*
* 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.overlay.snap;
import com.vividsolutions.jts.geom.*;
import com.vividsolutions.jts.operation.overlay.OverlayOp;
import com.vividsolutions.jts.operation.overlay.validate.OverlayResultValidator;
/**
* Performs an overlay operation using snapping and enhanced precision
* to improve the robustness of the result.
* This class only uses snapping
* if an error is detected when running the standard JTS overlay code.
* Errors detected include thrown exceptions
* (in particular, {@link TopologyException})
* and invalid overlay computations.
*
* @author Martin Davis
* @version 1.7
*/
public class SnapIfNeededOverlayOp
{
public static Geometry overlayOp(Geometry g0, Geometry g1, int opCode)
{
SnapIfNeededOverlayOp op = new SnapIfNeededOverlayOp(g0, g1);
return op.getResultGeometry(opCode);
}
public static Geometry intersection(Geometry g0, Geometry g1)
{
return overlayOp(g0, g1, OverlayOp.INTERSECTION);
}
public static Geometry union(Geometry g0, Geometry g1)
{
return overlayOp(g0, g1, OverlayOp.UNION);
}
public static Geometry difference(Geometry g0, Geometry g1)
{
return overlayOp(g0, g1, OverlayOp.DIFFERENCE);
}
public static Geometry symDifference(Geometry g0, Geometry g1)
{
return overlayOp(g0, g1, OverlayOp.SYMDIFFERENCE);
}
private Geometry[] geom = new Geometry[2];
public SnapIfNeededOverlayOp(Geometry g1, Geometry g2)
{
geom[0] = g1;
geom[1] = g2;
}
public Geometry getResultGeometry(int opCode)
{
Geometry result = null;
boolean isSuccess = false;
RuntimeException savedException = null;
try {
// try basic operation with input geometries
result = OverlayOp.overlayOp(geom[0], geom[1], opCode);
boolean isValid = true;
// not needed if noding validation is used
// boolean isValid = OverlayResultValidator.isValid(geom[0], geom[1], OverlayOp.INTERSECTION, result);
if (isValid)
isSuccess = true;
}
catch (RuntimeException ex) {
savedException = ex;
// ignore this exception, since the operation will be rerun
// System.out.println(ex.getMessage());
// ex.printStackTrace();
//System.out.println(ex.getMessage());
//System.out.println("Geom 0: " + geom[0]);
//System.out.println("Geom 1: " + geom[1]);
}
if (! isSuccess) {
// this may still throw an exception
// if so, throw the original exception since it has the input coordinates
try {
result = SnapOverlayOp.overlayOp(geom[0], geom[1], opCode);
}
catch (RuntimeException ex) {
throw savedException;
}
}
return result;
}
}