001 //$HeadURL: https://svn.wald.intevation.org/svn/deegree/base/branches/2.3_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 }