Application: gvSIG desktop » gvSIG geoprocess

/**

 * gvSIG. Desktop Geographic Information System.

 *

 * Copyright (C) 2007-2012 gvSIG Association.

 *

 * 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., 51 Franklin Street, Fifth Floor, Boston,

 * MA  02110-1301, USA.

 *

 * For any additional information, do not hesitate to contact us

 * at info AT gvsig.com, or visit our website www.gvsig.com.

 */

package org.gvsig.geoprocess.algorithm.buffer;

import java.util.ArrayList;

import java.util.List;

import java.util.Stack;

import com.vividsolutions.jts.geom.Geometry;

import com.vividsolutions.jts.geom.GeometryCollection;

import com.vividsolutions.jts.geom.GeometryFactory;

import com.vividsolutions.jts.geom.MultiPolygon;

import com.vividsolutions.jts.geom.Polygon;

import com.vividsolutions.jts.operation.buffer.BufferOp;

import com.vividsolutions.jts.operation.buffer.BufferParameters;

import com.vividsolutions.jts.simplify.TopologyPreservingSimplifier;

import es.unex.sextante.core.Sextante;

import es.unex.sextante.dataObjects.IVectorLayer;

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.geoprocess.algorithm.base.util.GeometryUtil;

import org.gvsig.geoprocess.algorithm.base.util.JTSFacade;

import org.gvsig.geoprocess.lib.sextante.AbstractSextanteGeoProcess;

/**

 * Buffer operation

 * 

 * @author <a href="mailto:nachobrodin@gmail.com">Nacho Brodin</a>

 */

public class InOutBufferOperation extends BufferOperation {

    /**

     * Builds an instance of this operation.

     * 

     * @param distance

     * @param layer

     * @param userDistance

     */

    public InOutBufferOperation(IDistance distance, IVectorLayer layer,

        double userDistance, AbstractSextanteGeoProcess p) {

        super(distance, layer, userDistance, p);

    }

    public EditableFeature invoke(org.gvsig.fmap.geom.Geometry g,

        Feature feature) {

        GeometryFactory geomFact = new GeometryFactory();

        Geometry newGeom = null;

        Geometry previousExteriorRing = null;

        Geometry previousInteriorRing = null;

        Geometry originalGeometry = GeometryUtil.geomToJTS(g);

        Geometry inputParam = originalGeometry;

        distance.setFeature(feature);

        double bufferDistance =

            distance.getBufferDistance(userDistance, projection,

                getDistanceUnits(), getMapUnits());

        if (originalGeometry.getDimension() != 0)

            inputParam =

                TopologyPreservingSimplifier.simplify(originalGeometry,

                    bufferDistance / 10d);

        for (int i = 1; i <= numberOfRadialBuffers; i++) {

            double distRing = i * bufferDistance;

            BufferOp bufOp = new BufferOp(inputParam);

            bufOp.setEndCapStyle(capBuffer == CAP_ROUND

                ? BufferParameters.CAP_ROUND : BufferParameters.CAP_SQUARE);

            Geometry out = bufOp.getResultGeometry(distRing);

            Geometry in = bufOp.getResultGeometry(-1 * distRing);

            boolean collapsedInterior = verifyNilGeometry(in);

            if (previousExteriorRing == null || previousInteriorRing == null) {

                if (collapsedInterior)

                    newGeom = out;

                else

                    newGeom = JTSFacade.difference(out, in);

            } else {

                if (collapsedInterior)

                    newGeom = JTSFacade.difference(out, previousExteriorRing);

                else {

                    Geometry outRing =

                        JTSFacade.difference(out, previousExteriorRing);

                    Geometry inRing =

                        JTSFacade.difference(previousInteriorRing, in);

                    Geometry[] geomArray = new Geometry[] { outRing, inRing };

                    newGeom = geomFact.createGeometryCollection(geomArray);

                    // FMap doesnt work with GeometryCollection, so we try to

                    // pass to a MultiPolygon.

                    List<Geometry> polygons = new ArrayList<Geometry>();

                    Stack<Geometry> stack = new Stack<Geometry>();

                    stack.push(newGeom);

                    while (stack.size() != 0) {

                        GeometryCollection geCol =

                            (GeometryCollection) stack.pop();

                        for (int j = 0; j < geCol.getNumGeometries(); j++) {

                            Geometry geometry = geCol.getGeometryN(j);

                            if (geometry instanceof GeometryCollection)

                                stack.push(geometry);

                            if (geometry instanceof Polygon)

                                polygons.add(geometry);

                        }

                    }

                    Polygon[] pols = new Polygon[polygons.size()];

                    pols = polygons.toArray(pols);

                    MultiPolygon newSolution =

                        geomFact.createMultiPolygon(pols);

                    newGeom = newSolution;

                }

            }

            try {

                    if (newGeom != null && !newGeom.isEmpty()) {

                            lastEditFeature =

                                    persister.addFeature(newGeom, id, -1 * distRing, distRing);

                            id++;

                    }

            } catch (CreateGeometryException e) {

                Sextante.addErrorToLog(e);

            } catch (DataException e) {

                Sextante.addErrorToLog(e);

            }

            previousExteriorRing = out;

            if (!collapsedInterior)

                previousInteriorRing = in;

        }

        return lastEditFeature;

    }

    /*

     * (non-Javadoc)

     * 

     * @see

     * org.gvsig.geoprocess.algorithm.base.core.GeometryOperation#invoke(org

     * .gvsig.fmap.geom.Geometry, org.gvsig.fmap.dal.feature.EditableFeature)

     */

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

        invoke(g, (Feature) feature);

    }

}