EditUtilities.java

/**
 * H2GIS is a library that brings spatial support to the H2 Database Engine
 * <http://www.h2database.com>. H2GIS is developed by CNRS
 * <http://www.cnrs.fr/>.
 *
 * This code is part of the H2GIS project. H2GIS 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;
 * version 3.0 of the License.
 *
 * H2GIS 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 <http://www.gnu.org/licenses/>.
 *
 *
 * For more information, please consult: <http://www.h2gis.org/>
 * or contact directly: info_at_h2gis.org
 */

package org.h2gis.functions.spatial.edit;

import com.vividsolutions.jts.geom.Geometry;
import com.vividsolutions.jts.geom.Point;
import com.vividsolutions.jts.operation.distance.DistanceOp;
import com.vividsolutions.jts.operation.distance.GeometryLocation;

/**
 * Common utilities used by the edit functions
 * 
 * @author Erwan Bocher
 */
public class EditUtilities {
    
    /**
     * Gets the coordinate of a Geometry that is the nearest of a given Point,
     * with a distance tolerance.
     *
     * @param g
     * @param p
     * @param tolerance
     * @return
     */
    public static GeometryLocation getVertexToSnap(Geometry g, Point p, double tolerance) {
        DistanceOp distanceOp = new DistanceOp(g, p);
        GeometryLocation snapedPoint = distanceOp.nearestLocations()[0];
        if (tolerance == 0 || snapedPoint.getCoordinate().distance(p.getCoordinate()) <= tolerance) {
            return snapedPoint;
        }
        return null;

    }
}