Application: gvSIG desktop » gvSIG geoprocess

/*

 * gvSIG. Sistema de Informaci?n Geogr?fica de la Generalitat Valenciana

 *

 * Copyright (C) 2010 Generalitat Valenciana.

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version 2

 * of the License, or (at your option) any later version.

 *

 * This program 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 General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,USA.

 */

package org.gvsig.sextante.app.algorithm.difference;

import com.vividsolutions.jts.geom.Geometry;

import com.vividsolutions.jts.precision.EnhancedPrecisionOp;

import es.unex.sextante.core.Sextante;

import org.gvsig.fmap.dal.exception.DataException;

import org.gvsig.fmap.dal.feature.EditableFeature;

import org.gvsig.fmap.dal.feature.Feature;

import org.gvsig.fmap.geom.exception.CreateGeometryException;

import org.gvsig.sextante.app.algorithm.base.core.GeometryOperation;

import org.gvsig.sextante.app.algorithm.base.util.GeometryUtil;

/**

 * Difference between two geometries

 * @author Nacho Brodin (nachobrodin@gmail.com)

 */

public class DifferenceOperation extends GeometryOperation {

        /**

         * Clipping geometry: the convex hull of the

         * clipping layer

         */

        private Geometry                         overlaysGeom     = null;

        public DifferenceOperation(org.gvsig.fmap.geom.Geometry overlays) {

                if(overlays != null)

                        this.overlaysGeom = GeometryUtil.geomToJTS(overlays);

        }

        /**

         * clips feature's geometry with the clipping geometry, preserving

         * feature's original attributes.

         * If feature's geometry doesn't touch clipping geometry, it will be

         * ignored.

         */

        public EditableFeature invoke(org.gvsig.fmap.geom.Geometry g, Feature feature) {

                if(g == null)

                        return lastEditFeature;

                com.vividsolutions.jts.geom.Geometry jtsGeom = GeometryUtil.geomToJTS(g);

                try {

                        if(overlaysGeom == null)

                                return persister.addFeature(feature, jtsGeom);

                        if(!jtsGeom.getEnvelope().intersects(overlaysGeom.getEnvelope())) {

                                lastEditFeature = persister.addFeature(feature, jtsGeom);

                                return lastEditFeature;

                        }

                        if(jtsGeom.intersects(overlaysGeom)) {

                                Geometry newGeom = EnhancedPrecisionOp.difference(jtsGeom, overlaysGeom);

                                if(!newGeom.isEmpty())

                                        lastEditFeature = persister.addFeature(feature, newGeom);

                        } else

                                lastEditFeature = persister.addFeature(feature, jtsGeom);

                } catch (CreateGeometryException e) {

                        Sextante.addErrorToLog(e);

                } catch (DataException e) {

                        Sextante.addErrorToLog(e);

                }

                return lastEditFeature;

        }

        /**

         * clips feature's geometry with the clipping geometry, preserving

         * feature's original attributes.

         * If feature's geometry doesn't touch clipping geometry, it will be

         * ignored.

         */

        public void invoke(org.gvsig.fmap.geom.Geometry g, EditableFeature feature) {

                if(g == null)

                        return;

                com.vividsolutions.jts.geom.Geometry jtsGeom = GeometryUtil.geomToJTS(g);

                try {

                        if(overlaysGeom == null)

                                persister.addFeature(feature, jtsGeom);

                        if(!jtsGeom.getEnvelope().intersects(overlaysGeom.getEnvelope()))

                                persister.addFeature(feature, jtsGeom);

                        if(jtsGeom.intersects(overlaysGeom)) {

                                try {

                                        Geometry newGeom = EnhancedPrecisionOp.difference(jtsGeom, overlaysGeom);

                                        persister.addFeature(feature, newGeom);

                                } catch (CreateGeometryException e) {

                                        Sextante.addErrorToLog(e);

                                } catch (DataException e) {

                                        Sextante.addErrorToLog(e);

                                }

                        } else

                                persister.addFeature(feature, jtsGeom);

                } catch (DataException e) {

                        Sextante.addErrorToLog(e);

                } catch (CreateGeometryException e) {

                        Sextante.addErrorToLog(e);

                }

        }

}