/*
* 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.MergePolygonRequest;
import org.geomajas.command.dto.MergePolygonResponse;
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.Geometry;
import com.vividsolutions.jts.geom.GeometryFactory;
import com.vividsolutions.jts.geom.MultiPolygon;
import com.vividsolutions.jts.geom.Polygon;
import com.vividsolutions.jts.geom.PrecisionModel;
/**
* <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 MergePolygonCommand implements Command<MergePolygonRequest, MergePolygonResponse> {
@Autowired
private DtoConverterService converter;
public MergePolygonResponse getEmptyCommandResponse() {
return new MergePolygonResponse();
}
public void execute(MergePolygonRequest request, MergePolygonResponse response) throws Exception {
Polygon[] polygons = new Polygon[request.getPolygons().length];
for (int i = 0; i < request.getPolygons().length; i++) {
try {
polygons[i] = (Polygon) converter.toInternal(request.getPolygons()[i]);
} catch (Exception e) {
throw new GeomajasException(e, ExceptionCode.MERGE_NO_POLYGON);
}
}
int precision = polygons[0].getPrecisionModel().getMaximumSignificantDigits() - 1;
PrecisionModel precisionModel = new PrecisionModel(Math.pow(10.0, precision));
GeometryFactory factory = new GeometryFactory(precisionModel, polygons[0].getSRID());
Geometry temp = factory.createGeometry(polygons[0]);
for (int i = 1; i < polygons.length; i++) {
Geometry polygon = factory.createGeometry(polygons[i]);
temp = temp.union(polygon.buffer(Math.pow(10.0, -(precision - 1))));
}
if (temp instanceof Polygon) {
MultiPolygon mp = factory.createMultiPolygon(new Polygon[] { (Polygon) temp });
response.setGeometry(converter.toDto(mp));
} else if (temp instanceof MultiPolygon && temp.getNumGeometries() != 0
&& (request.isAllowMultiPolygon() || temp.getNumGeometries() == 1)) {
response.setGeometry(converter.toDto(temp));
} else {
throw new GeomajasException(ExceptionCode.MERGE_NO_POLYGON);
}
}
}