    001    //$HeadURL: https://svn.wald.intevation.org/svn/deegree/base/branches/2.4_testing/src/org/deegree/crs/projections/cylindric/Mercator.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
    037    package org.deegree.crs.projections.cylindric;
    038
    039    import static org.deegree.crs.projections.ProjectionUtils.calcPhiFromConformalLatitude;
    040    import static org.deegree.crs.projections.ProjectionUtils.preCalcedThetaSeries;
    041
    042    import javax.vecmath.Point2d;
    043
    044    import org.deegree.crs.Identifiable;
    045    import org.deegree.crs.components.Unit;
    046    import org.deegree.crs.coordinatesystems.GeographicCRS;
    047    import org.deegree.crs.exceptions.ProjectionException;
    048    import org.deegree.crs.projections.ProjectionUtils;
    049    import org.deegree.framework.log.ILogger;
    050    import org.deegree.framework.log.LoggerFactory;
    051
    052    /**
    053     * The <code>Mercator</code> projection has following properties:
    054     * <ul>
    055     * <li>Cylindircal</li>
    056     * <li>Conformal</li>
    057     * <li>Meridians are equally spaced straight lines</li>
    058     * <li>Parallels are unequally spaced straight lines closest near the equator, cutting meridians at right angles.</li>
    059     * <li>Scale is true along the Equator, or along two parallels equidistant from the Equator</li>
    060     * <li>Loxodromes (rhumb lines) are straight lines</li>
    061     * <li>Not perspective</li>
    062     * <li>Poles are at infinity; great distortion or area in polar regions</li>
    063     * <li>Used for navigation</li>
    064     * <li>Presented by Mercator in 1569</li>
    065     * </ul>
    066     *
    067     * @author <a href="mailto:bezema@lat-lon.de">Rutger Bezema</a>
    068     *
    069     * @author last edited by: $Author: rbezema $
    070     *
    071     * @version $Revision: 19653 $, $Date: 2009-09-15 14:56:30 +0200 (Di, 15. Sep 2009) $
    072     *
    073     */
    074    public class Mercator extends CylindricalProjection {
    075
    076        private static final long serialVersionUID = -8410660923891924617L;
    077
    078        private static ILogger LOG = LoggerFactory.getLogger( Mercator.class );
    079
    080        private double[] preCalcedPhiSeries;
    081
    082        /**
    083         * @param geographicCRS
    084         * @param falseNorthing
    085         * @param falseEasting
    086         * @param naturalOrigin
    087         * @param units
    088         * @param scale
    089         * @param id
    090         *            an identifiable instance containing information about this projection
    091         */
    092        public Mercator( GeographicCRS geographicCRS, double falseNorthing, double falseEasting, Point2d naturalOrigin,
    093                         Unit units, double scale, Identifiable id ) {
    094            super( geographicCRS, falseNorthing, falseEasting, naturalOrigin, units, scale, true, false, id );
    095            preCalcedPhiSeries = preCalcedThetaSeries( getSquaredEccentricity() );
    096        }
    097
    098        /**
    099         * Sets the id to EPSG:9804
    100         *
    101         * @param geographicCRS
    102         * @param falseNorthing
    103         * @param falseEasting
    104         * @param naturalOrigin
    105         * @param units
    106         * @param scale
    107         */
    108        public Mercator( GeographicCRS geographicCRS, double falseNorthing, double falseEasting, Point2d naturalOrigin,
    109                         Unit units, double scale ) {
    110            this( geographicCRS, falseNorthing, falseEasting, naturalOrigin, units, scale, new Identifiable( "EPSG::9804" ) );
    111        }
    112
    113        @Override
    114        public Point2d doInverseProjection( double x, double y )
    115                                throws ProjectionException {
    116            if ( LOG.isDebug() ) {
    117                LOG.logDebug( "(Mercator incoming inv proj) x:" + x + ", y:" + y );
    118            }
    119            Point2d result = new Point2d( 0, 0 );
    120            LOG.logDebug( "InverseProjection, incoming points x: " + x + " y: " + y );
    121            x -= getFalseEasting();
    122            y -= getFalseNorthing();
    123
    124            result.x = ( x / getScaleFactor() ) + getProjectionLongitude();
    125            result.y = ProjectionUtils.HALFPI - 2. * Math.atan( Math.exp( -y / getScaleFactor() ) );
    126            if ( !isSpherical() ) {
    127                result.y = calcPhiFromConformalLatitude( result.y, preCalcedPhiSeries );
    128            }
    129            if ( LOG.isDebug() ) {
    130                LOG.logDebug( "(outgoing) lam:" + Math.toDegrees( result.x ) + ", phi:" + Math.toDegrees( result.y ) );
    131            }
    132            return result;
    133        }
    134
    135        @Override
    136        public Point2d doProjection( double lambda, double phi )
    137                                throws ProjectionException {
    138            if ( LOG.isDebug() ) {
    139                LOG.logDebug( "(Mercator incoming proj) lam: " + Math.toDegrees( lambda ) + ", phi:" + Math.toDegrees( phi ) );
    140            }
    141            Point2d result = new Point2d( 0, 0 );
    142            lambda -= getProjectionLongitude();
    143
    144            result.x = getScaleFactor() * lambda;
    145            if ( isSpherical() ) {
    146                result.y = getScaleFactor() * Math.log( Math.tan( ProjectionUtils.QUARTERPI + 0.5 * phi ) );
    147            } else {
    148                result.y = -getScaleFactor()
    149                           * Math.log( ProjectionUtils.tanHalfCoLatitude( phi, Math.sin( phi ), getEccentricity() ) );
    150            }
    151            result.x += getFalseEasting();
    152            result.y += getFalseNorthing();
    153            if ( LOG.isDebug() ) {
    154                LOG.logDebug( "(outgoing) x:" + result.x + ", y:" + result.y );
    155            }
    156            return result;
    157        }
    158
    159        @Override
    160        public String getImplementationName() {
    161            return "mercator";
    162        }
    163
    164    }