Application: gvSIG desktop

/* 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

 */

package com.iver.cit.gvsig.graphtests;

import junit.framework.TestCase;

import org.gvsig.graph.core.TurnUtil;

import com.vividsolutions.jts.algorithm.CGAlgorithms;

import com.vividsolutions.jts.geom.Coordinate;

import com.vividsolutions.jts.geom.LineSegment;

public class TestAngle extends TestCase {

        public void testAngle() {

                Coordinate c1, c2, c3;

                double grados;

                // 0 grados (no hay giro

                c1 = new Coordinate(-1, 0);

                c2 = new Coordinate(0, 0);

                c3 = new Coordinate(1, 0);

                grados = TurnUtil.angle(c1, c2, c3);

                assertEquals(0.0, grados, 0.0);

                // 90 grados (giro a la izquierda)

                c1 = new Coordinate(0, -1);

                c2 = new Coordinate(0, 0);

                c3 = new Coordinate(-1, 0);

                grados = TurnUtil.angle(c1, c2, c3);

                assertEquals(90.0, grados, 0.0);

                // 180 grados (360 grados) giro completo

                c1 = new Coordinate(-1, 0);

                c2 = new Coordinate(0, 0);

                c3 = new Coordinate(-1, 0);

                grados = TurnUtil.angle(c1, c2, c3);

                assertEquals(180.0, grados, 0.0);

                // 270 grados (giro a la derecha)

                c1 = new Coordinate(-1, 0);

                c2 = new Coordinate(0, 0);

                c3 = new Coordinate(0, 1);

                grados = TurnUtil.angle(c1, c2, c3);

                assertEquals(270.0, grados, 0.0);

        }

        private double angle(Coordinate c1, Coordinate c2, Coordinate c3) {

                double resul = 0.0;

                // Normalizamos:

                Coordinate origin = new Coordinate(0.0, 0.0);

                Coordinate cAux1 = new Coordinate(c2.x-c1.x, c2.y-c1.y);

                Coordinate cAux2 = new Coordinate(c3.x-c2.x, c3.y-c2.y);

                LineSegment v1 = new LineSegment(origin, cAux1);

                LineSegment v2 = new LineSegment(origin, cAux2);

                double jtsResul = CGAlgorithms.orientationIndex(c1, c2, c3);

                double prodEscalar = cAux1.x*cAux2.x + cAux1.y*cAux2.y;

                double cosAlpha = prodEscalar / (v1.getLength() * v2.getLength()) ; 

                resul = Math.toDegrees(Math.acos(cosAlpha));

        if (cAux1.x * cAux2.y > cAux1.y * cAux2.x) {

            resul = 360 - resul;

        }

                System.out.println(resul);

                return resul;

        }

}