Application: gvSIG desktop

/*

 * Created on 09-nov-2006

 *

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

 *

 * Copyright (C) 2004 IVER T.I. and 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.

 *

 * For more information, contact:

 *

 *  Generalitat Valenciana

 *   Conselleria d'Infraestructures i Transport

 *   Av. Blasco Ib??ez, 50

 *   46010 VALENCIA

 *   SPAIN

 *

 *      +34 963862235

 *   gvsig@gva.es

 *      www.gvsig.gva.es

 *

 *    or

 *

 *   IVER T.I. S.A

 *   Salamanca 50

 *   46005 Valencia

 *   Spain

 *

 *   +34 963163400

 *   dac@iver.es

 */

/* CVS MESSAGES:

 *

 * $Id: SnappingCoordinateMap.java 13853 2007-09-19 15:28:42Z azabala $

 * $Log$

 * Revision 1.2  2007-09-19 15:28:42  azabala

 * added a fixed hashCode (until we fix the requeriment of compute the same hashCode for all points in the same cluster circle)

 *

 * Revision 1.1  2006/12/04 19:50:43  azabala

 * *** empty log message ***

 *

 * Revision 1.2  2006/11/13 20:41:08  azabala

 * *** empty log message ***

 *

 * Revision 1.1  2006/11/09 21:08:32  azabala

 * *** empty log message ***

 *

 *

 */

package com.iver.cit.gvsig.util;

import java.util.Comparator;

import java.util.Hashtable;

import com.vividsolutions.jts.geom.Coordinate;

import com.vividsolutions.jts.geomgraph.Node;

public class SnappingCoordinateMap extends Hashtable {

        class SnapCoordinate extends Coordinate {

                public SnapCoordinate(Coordinate arg0) {

                        super(arg0);

                }

                public boolean equals(Object obj) {

                        if(! (obj instanceof SnapCoordinate))

                                return false;

                        SnapCoordinate other = (SnapCoordinate) obj;

                        return other.distance(this) <= snapTolerance;

                }

                public int hashCode() {

//                         int result = 17;

//                         double xs = simplify(x);

//                         double ys = simplify(y);

//                         result = 37 * result + hashCode(xs);

//                         result = 37 * result + hashCode(ys);

//                         return result;

                        return 1; // this is not efficient. look for a hash algorithm to ensure

                        //all points in the same tolerance radius returns the same hash code

                }

                public double simplify(double coordinate){

                        if(scaleFactor == 0d)

                                return coordinate;

                        return Math.round(coordinate * scaleFactor) / scaleFactor;

                }

        }

        private double snapTolerance;

        private double scaleFactor;

        public SnappingCoordinateMap(double snapTolerance) {

                super();

                this.snapTolerance = snapTolerance;

                if(snapTolerance != 0d)

                        this.scaleFactor = 1d / snapTolerance;

        }

        class MinDistCoordComparator implements Comparator {

                Coordinate coord;

                MinDistCoordComparator(Coordinate coord) {

                        this.coord = coord;

                }

                public int compare(Object arg0, Object arg1) {

                        Coordinate c1 = ((Node) arg0).getCoordinate();

                        Coordinate c2 = ((Node) arg1).getCoordinate();

                        double d1 = c1.distance(coord);

                        double d2 = c2.distance(coord);

                        if (d1 < d2)

                                return 1;

                        if (d1 > d2)

                                return -1;

                        else

                                return 0;

                }

        }

        public Object put(Object key, Object obj){

                if(! (key instanceof Coordinate) )

                        return null;

                return super.put(new SnapCoordinate((Coordinate)key),

                                obj);

        }

        public Object get(Object key){

                if(! (key instanceof Coordinate) )

                        return null;

                return super.get(new SnapCoordinate((Coordinate)key));

        }

        public boolean containsKey(Object key){

                if(! (key instanceof Coordinate) )

                        return false;

                return super.containsKey(new SnapCoordinate((Coordinate)key));

        }

        public static void main(String[] args){

                SnappingCoordinateMap map = 

                        new SnappingCoordinateMap(0.1);

                Coordinate c0 = new Coordinate(0, 0);

                Coordinate c1 = new Coordinate(0.01, 0.01);

                Coordinate c2 = new Coordinate(0.31, 0.41);

                Coordinate c3 = new Coordinate(0.29, 0.39);

                Coordinate c4 = new Coordinate(0.299, 0.411);

                map.put(c0, c0);

                map.put(c1, c1);

                map.put(c2, c2);

                map.put(c3, c3);

                map.put(c4, c4);

                System.out.println(map.size());

                java.util.Set values = map.entrySet();

                System.out.println(values.size());

        }

}