/*
* 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.revolsys.geometry.test.geomop;
import com.revolsys.geometry.model.Geometry;
import com.revolsys.geometry.model.Point;
import com.revolsys.geometry.operation.overlay.OverlayOp;
import com.revolsys.geometry.operation.overlay.validate.OverlayResultValidator;
import com.revolsys.geometry.test.testrunner.GeometryResult;
import com.revolsys.geometry.test.testrunner.Result;
import com.revolsys.record.io.format.wkt.EWktWriter;
/**
* A {@link GeometryOperation} which validates the result of overlay operations.
* If an invalid result is found, an exception is thrown (this is the most
* convenient and noticeable way of flagging the problem when using the TestRunner).
* All other Geometry methods are executed normally.
* <p>
* In order to eliminate the need to specify the precise result of an overlay,
* this class forces the final return value to be <tt>GEOMETRYCOLLECTION EMPTY</tt>.
* <p>
* This class can be used via the <tt>-geomop</tt> command-line option
* or by the <tt><geometryOperation></tt> XML test file setting.
*
* @author Martin Davis
*
*/
public class OverlayValidatedGeometryOperation implements GeometryOperation {
private static final double AREA_DIFF_TOL = 5.0;
public static double areaDiff(final Geometry g0, final Geometry g1) {
final double areaA = g0.getArea();
final double areaAdiffB = g0.difference(g1).getArea();
final double areaAintB = g0.intersection(g1).getArea();
return areaA - areaAdiffB - areaAintB;
}
public static Geometry invokeGeometryOverlayMethod(final int opCode, final Geometry g0,
final Geometry g1) {
switch (opCode) {
case OverlayOp.INTERSECTION:
return g0.intersection(g1);
case OverlayOp.UNION:
return g0.union(g1);
case OverlayOp.DIFFERENCE:
return g0.difference(g1);
case OverlayOp.SYMDIFFERENCE:
return g0.symDifference(g1);
}
throw new IllegalArgumentException("Unknown overlay op code");
}
public static int overlayOpCode(final String methodName) {
if (methodName.equals("intersection")) {
return OverlayOp.INTERSECTION;
}
if (methodName.equals("union")) {
return OverlayOp.UNION;
}
if (methodName.equals("difference")) {
return OverlayOp.DIFFERENCE;
}
if (methodName.equals("symDifference")) {
return OverlayOp.SYMDIFFERENCE;
}
return -1;
}
private GeometryMethodOperation chainOp = new GeometryMethodOperation();
private final boolean returnEmptyGC = true;
public OverlayValidatedGeometryOperation() {
}
/**
* Creates a new operation which chains to the given {@link GeometryMethodOperation}
* for non-intercepted methods.
*
* @param chainOp the operation to chain to
*/
public OverlayValidatedGeometryOperation(final GeometryMethodOperation chainOp) {
this.chainOp = chainOp;
}
private void areaValidate(final Geometry g0, final Geometry g1) {
final double areaDiff = areaDiff(g0, g1);
// System.out.println("Area diff = " + areaDiff);
if (Math.abs(areaDiff) > AREA_DIFF_TOL) {
final String msg = "Operation result is invalid [AreaTest] (" + areaDiff + ")";
reportError(msg);
}
}
@Override
public Class getReturnType(final String opName) {
return this.chainOp.getReturnType(opName);
}
/**
* Invokes the named operation
*
* @param opName
* @param geometry
* @param args
* @return the result
* @throws Exception
* @see GeometryOperation#invoke
*/
@Override
public Result invoke(final String opName, final Geometry geometry, final Object[] args)
throws Exception {
final int opCode = overlayOpCode(opName);
// if not an overlay op, do the default
if (opCode < 0) {
return this.chainOp.invoke(opName, geometry, args);
}
return invokeValidatedOverlayOp(opCode, geometry, args);
}
/**
* Invokes an overlay op, optionally using snapping,
* and optionally validating the result.
*
* @param opCode
* @param g0
* @param args
* @return the result
* @throws Exception
*/
public Result invokeValidatedOverlayOp(final int opCode, final Geometry g0, final Object[] args)
throws Exception {
Geometry result = null;
final Geometry g1 = (Geometry)args[0];
result = invokeGeometryOverlayMethod(opCode, g0, g1);
// validate
validate(opCode, g0, g1, result);
areaValidate(g0, g1);
/**
* Return an empty GeometryCollection as the result.
* This allows the test case to avoid specifying an exact result
*/
if (this.returnEmptyGC) {
result = result.getGeometryFactory().geometryCollection();
}
return new GeometryResult(result);
}
private void reportError(final String msg) {
// System.out.println(msg);
throw new RuntimeException(msg);
}
private void validate(final int opCode, final Geometry g0, final Geometry g1,
final Geometry result) {
final OverlayResultValidator validator = new OverlayResultValidator(g0, g1, result);
// check if computed result is valid
if (!validator.isValid(opCode)) {
final Point invalidLoc = validator.getInvalidLocation();
final String msg = "Operation result is invalid [OverlayResultValidator] ( "
+ EWktWriter.point(invalidLoc) + " )";
reportError(msg);
}
}
}