/*
* This is part of Geomajas, a GIS framework, http://www.geomajas.org/.
*
* Copyright 2008-2011 Geosparc nv, http://www.geosparc.com/, Belgium.
*
* The program is available in open source according to the GNU Affero
* General Public License. All contributions in this program are covered
* by the Geomajas Contributors License Agreement. For full licensing
* details, see LICENSE.txt in the project root.
*/
package org.geomajas.command.geometry;
import org.geomajas.command.Command;
import org.geomajas.command.dto.SplitPolygonRequest;
import org.geomajas.command.dto.SplitPolygonResponse;
import org.geomajas.geometry.Geometry;
import org.geomajas.global.ExceptionCode;
import org.geomajas.global.GeomajasException;
import org.geomajas.service.DtoConverterService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import com.vividsolutions.jts.geom.LineString;
import com.vividsolutions.jts.geom.MultiPolygon;
import com.vividsolutions.jts.geom.Polygon;
/**
* <p>
* This command splits a polygon or multipolygon by a linestring, and returns an array of resulting
* polygons/multipolygons.
* </p>
*
* @author Pieter De Graef
*/
@Component()
public class SplitPolygonCommand implements Command<SplitPolygonRequest, SplitPolygonResponse> {
@Autowired
private DtoConverterService converter;
public SplitPolygonResponse getEmptyCommandResponse() {
return new SplitPolygonResponse();
}
public void execute(SplitPolygonRequest request, SplitPolygonResponse response) throws Exception {
// convert to most accurate precision model
com.vividsolutions.jts.geom.Geometry jtsGeometry = converter.toInternal(request.getGeometry());
if (!(jtsGeometry instanceof Polygon)) {
throw new GeomajasException(ExceptionCode.UNEXPECTED_PROBLEM, "geometry has to be a Polygon");
}
Polygon polygon = (Polygon) converter.toInternal(request.getGeometry());
// Convert to the polygons precision model:
jtsGeometry = converter.toInternal(request.getSplitter());
if (!(jtsGeometry instanceof LineString)) {
throw new GeomajasException(ExceptionCode.UNEXPECTED_PROBLEM, "splitter has to be a LineString");
}
LineString preciseLine = (LineString) jtsGeometry;
int precision = polygon.getPrecisionModel().getMaximumSignificantDigits() - 1;
com.vividsolutions.jts.geom.Geometry bufferedLine = preciseLine.buffer(Math.pow(10.0, -precision));
com.vividsolutions.jts.geom.Geometry diff = polygon.difference(bufferedLine);
if (diff instanceof Polygon) {
response.setGeometries(new Geometry[] { converter.toDto(diff) });
} else if (diff instanceof MultiPolygon) {
Geometry[] polygons = new Geometry[diff.getNumGeometries()];
for (int i = 0; i < diff.getNumGeometries(); i++) {
polygons[i] = converter.toDto(diff.getGeometryN(i));
}
response.setGeometries(polygons);
}
}
}