Application: gvSIG desktop

/*

 * Created on 20-oct-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: TurnUtil.java 8264 2006-10-23 18:51:42Z azabala $

* $Log$

* Revision 1.2  2006-10-23 18:51:42  azabala

* *** empty log message ***

*

* Revision 1.1  2006/10/20 19:54:01  azabala

* *** empty log message ***

*

*

*/

package com.iver.cit.gvsig.graph.core;

import com.iver.cit.gvsig.fmap.core.IFeature;

import com.vividsolutions.jts.geom.Coordinate;

import com.vividsolutions.jts.geom.Geometry;

import com.vividsolutions.jts.geom.LineString;

import com.vividsolutions.jts.geom.MultiLineString;

public class TurnUtil {

        public static final int TURN_RIGHT = 0;

        public static final int TURN_LEFT = 1;

        public static final int GO_STRAIGH_ON = 2;

        public static final int TURN_U = 4;

        public static boolean checkIsLine(Geometry geometry){

                if(geometry instanceof LineString || geometry instanceof MultiLineString)

                        return true;

                else

                        return false;

        }        

        public static final int getDirection(IFeature feature1, IFeature feature2){

                Geometry geom1 = feature1.getGeometry().toJTSGeometry();

                Geometry geom2 = feature2.getGeometry().toJTSGeometry();

                if(!checkIsLine(geom1))

                        return -1;

                if(!checkIsLine(geom2))

                        return -1;

            Coordinate[] coords1 = geom1.getCoordinates();

            Coordinate p0 = coords1[coords1.length -2];

            Coordinate p1 = coords1[coords1.length -1];

            Coordinate[] coords2 = geom2.getCoordinates();

            Coordinate p2 = coords2[1];

                 double dx = p1.x - p0.x;

             double dy = p1.y - p0.y;

             double angle1 = Math.atan2(dy, dx);

             dx = p2.x - p1.x;

             dy = p2.y - p1.y;

             double angle2 = Math.atan2(dy, dx);

             double turnAngle = angle1 - angle2;

             double deegreeAngle = Math.toDegrees(turnAngle);

             if (Math.abs(deegreeAngle) > 180){

                     if(deegreeAngle < 0){

                             deegreeAngle = 360 - Math.abs(deegreeAngle);

                     }else{

                             deegreeAngle = deegreeAngle - 360;

                     }

             }

             if(Math.abs(deegreeAngle) <= 30)

                     return GO_STRAIGH_ON;

             else if(deegreeAngle <= 0)

                     return TURN_LEFT;

             else

                     return TURN_RIGHT;

        }        

        /**

         * 

         * Code extracted from JUMP

         * 

           * Returns the angle between two vectors.

           * @param a1 the angle of one vector, between -Pi and Pi

           * @param a2 the angle of the other vector, between -Pi and Pi

           * @return the angle (in radians) between the two vectors, between 0 and Pi

           */

//          public static double diff(double a1, double a2) {

//              double da;

//

//              if (a1 < a2) {

//                  da = a2 - a1;

//              } else {

//                  da = a1 - a2;

//              }

//

//              if (da > Math.PI) {

//                  da = (2 * Math.PI) - da;

//              }

//              return da;

//          }

}