001    //$HeadURL: https://svn.wald.intevation.org/svn/deegree/base/branches/2.3_testing/src/org/deegree/ogcwebservices/wpvs/utils/SunLight.java $
002    /*----------------------------------------------------------------------------
003     This file is part of deegree, http://deegree.org/
004     Copyright (C) 2001-2009 by:
005       Department of Geography, University of Bonn
006     and
007       lat/lon GmbH
008    
009     This library is free software; you can redistribute it and/or modify it under
010     the terms of the GNU Lesser General Public License as published by the Free
011     Software Foundation; either version 2.1 of the License, or (at your option)
012     any later version.
013     This library is distributed in the hope that it will be useful, but WITHOUT
014     ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
015     FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
016     details.
017     You should have received a copy of the GNU Lesser General Public License
018     along with this library; if not, write to the Free Software Foundation, Inc.,
019     59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
020    
021     Contact information:
022    
023     lat/lon GmbH
024     Aennchenstr. 19, 53177 Bonn
025     Germany
026     http://lat-lon.de/
027    
028     Department of Geography, University of Bonn
029     Prof. Dr. Klaus Greve
030     Postfach 1147, 53001 Bonn
031     Germany
032     http://www.geographie.uni-bonn.de/deegree/
033    
034     e-mail: info@deegree.org
035    ----------------------------------------------------------------------------*/
036    package org.deegree.ogcwebservices.wpvs.utils;
037    
038    import javax.vecmath.Color3f;
039    
040    /**
041     * class for calculating sun light according to a specific tima, day of
042     * the year (northern hemisper)
043     *
044     *
045     * @version $Revision: 18195 $
046     * @author <a href="mailto:poth@lat-lon.de">Andreas Poth</a>
047     * @author last edited by: $Author: mschneider $
048     *
049     * $Revision: 18195 $, $Date: 2009-06-18 17:55:39 +0200 (Do, 18. Jun 2009) $
050     *
051     */
052    public class SunLight {
053    
054        private static final float BASE_LIGHT_INTENSITY = 0.95f;
055        private SunPosition sunPosition;
056        private double latitude;
057    
058        /**
059         * @param latitude the position on the earth
060         * @param sunPosition the Position of the sun
061         */
062        public SunLight( double latitude, SunPosition sunPosition ){
063            this.latitude = latitude;
064            this.sunPosition = sunPosition;
065        }
066    
067    
068        /**
069         * @return a Color of the sunlight
070         */
071        public Color3f calculateSunlight( ) {
072    
073            double vDir = sunPosition.getVerticalSunposition( latitude );
074            float c = 7.25f*((float)Math.sin( vDir ));
075    
076            float r = (float)(BASE_LIGHT_INTENSITY + (c/16.0) + 0.05)*0.6f;
077            float g = (float)(BASE_LIGHT_INTENSITY + (c/18.5) + 0.05)*0.6f;
078            float b = (float)(BASE_LIGHT_INTENSITY  +(c/17.0) + 0.05)*0.55f;
079            if ( r > 1 ) r = 1;
080            if ( g > 1 ) g = 1;
081            if ( b > 1 ) b = 1;
082    
083            return new Color3f( r, g, b );
084        }
085    
086        /**
087         * @param cloudFactor describing howmuch clouds cover the sun
088         * @return the intensity of the
089         */
090        public float calcSunlightIntensity( float cloudFactor) {
091            if( cloudFactor < 0 || cloudFactor > 1.0 )
092                cloudFactor = 1;
093            Color3f vec = calculateSunlight( );
094            return ((vec.x + vec.y + vec.z)* 0.33333f )* cloudFactor;
095        }
096    
097    }