| gvSIG desktop 1

/* gvSIG. Geographic Information System of the Valencian Government

 *

 * Copyright (C) 2007-2008 Infrastructures and Transports Department

 * of the Valencian Government (CIT)

 * 

 * 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.

 * 

 */

/*

 * AUTHORS (In addition to CIT):

 * 2009 {Iver T.I.}   {Task}

 */

package org.gvsig.fmap.geom.operation.utils;

import org.gvsig.fmap.geom.Geometry;

import org.gvsig.fmap.geom.GeometryLocator;

import org.gvsig.fmap.geom.GeometryManager;

import org.gvsig.fmap.geom.Geometry.TYPES;

import org.gvsig.fmap.geom.operation.GeometryOperation;

import org.gvsig.fmap.geom.operation.GeometryOperationContext;

import org.gvsig.fmap.geom.operation.GeometryOperationException;

import org.gvsig.fmap.geom.operation.GeometryOperationNotSupportedException;

import org.gvsig.fmap.geom.operation.distance.PointDistance;

import org.gvsig.fmap.geom.primitive.Point;

import org.gvsig.fmap.geom.type.GeometryType;

import org.gvsig.tools.locator.LocatorException;

/**

 * @author <a href="mailto:jpiera@gvsig.org">Jorge Piera</a>

 */

public class PointGetAngle extends GeometryOperation{

    public static final String NAME = "getAngle";

        public static final int CODE = GeometryLocator.getGeometryManager().

            getGeometryOperationCode(NAME);        

        /* (non-Javadoc)

         * @see org.gvsig.fmap.geom.operation.GeometryOperation#getOperationIndex()

         */

        public int getOperationIndex() {

                return CODE;

        }

        /* (non-Javadoc)

         * @see org.gvsig.fmap.geom.operation.GeometryOperation#invoke(org.gvsig.fmap.geom.Geometry, org.gvsig.fmap.geom.operation.GeometryOperationContext)

         */

        public Object invoke(Geometry geom, GeometryOperationContext ctx)

        throws GeometryOperationException {

                Geometry geom2 = (Geometry)ctx.getAttribute("geom");

                GeometryType geomType2 = geom2.getGeometryType();

                if ((TYPES.POINT != geom.getType()) && TYPES.POINT != geomType2.getType()){

                        throw new UnsupportedOperationException("The distance only can be execudet between two points");

                }

                Point start = (Point)geom;

                Point end = (Point)geom;

                double distance;

                try {

                        distance = ((Double)GeometryLocator.getGeometryManager().invokeOperation(PointDistance.CODE, geom, ctx)).doubleValue();

                } catch (LocatorException e) {

                        throw new GeometryOperationException(e);

                } catch (GeometryOperationNotSupportedException e) {

                        throw new GeometryOperationException(e);

                }

                double angle = Math.acos((end.getX() - start.getX()) / distance);

                if (start.getY() > end.getY()) {

                        angle = -angle;

                }

                if (angle < 0) {

                        angle += (2 * Math.PI);

                }

                return new Double(angle);

        }

}