001    //$HeadURL: svn+ssh://jwilden@svn.wald.intevation.org/deegree/base/branches/2.5_testing/src/org/deegree/crs/transformations/coordinate/ConcatenatedTransform.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.transformations.coordinate;
038    
039    import java.util.List;
040    
041    import javax.vecmath.Point3d;
042    
043    import org.deegree.crs.Identifiable;
044    import org.deegree.crs.exceptions.TransformationException;
045    import org.deegree.crs.transformations.Transformation;
046    
047    /**
048     * The <code>ConcatenatedTransform</code> class allows the connection of two transformations.
049     * <p>
050     * Calling inverse on this transformation will invert the whole underlying transformation chain. For example, if A * (B
051     * *C)=D and D is this transformation calling D.inverse() will result in (C.inverse * B.inverse) * A.inverse.
052     * </p>
053     *
054     * @author <a href="mailto:bezema@lat-lon.de">Rutger Bezema</a>
055     *
056     * @author last edited by: $Author: mschneider $
057     *
058     * @version $Revision: 18195 $, $Date: 2009-06-18 17:55:39 +0200 (Do, 18 Jun 2009) $
059     *
060     */
061    
062    public class ConcatenatedTransform extends CRSTransformation {
063    
064        private static final long serialVersionUID = 9033876225805810824L;
065    
066        private boolean isIdentitiy = false;
067    
068        private Transformation firstTransform;
069    
070        private Transformation secondTransform;
071    
072        /**
073         * Creates a transform by concatenating two existing transforms. A concatenated transform applies two transforms,
074         * one after the other. The dimension of the output space of the first transform must match the dimension of the
075         * input space in the second transform.
076         *
077         * @param first
078         *            The first transformation to apply to given points.
079         * @param second
080         *            The second transformation to apply to given points.
081         * @param id
082         *            an identifiable instance containing information about this transformation
083         */
084        public ConcatenatedTransform( Transformation first, Transformation second, Identifiable id ) {
085            super( first.getSourceCRS(), second.getTargetCRS(), id );
086            if ( first.isIdentity() && second.isIdentity() ) {
087                isIdentitiy = true;
088            }
089            firstTransform = first;
090            secondTransform = second;
091        }
092    
093        /**
094         * Creates a transform by concatenating two existing transforms. A concatenated transform applies two transforms,
095         * one after the other. The dimension of the output space of the first transform must match the dimension of the
096         * input space in the second transform.
097         *
098         * Creates an Identifiable using the {@link CRSTransformation#createFromTo(String, String)} method.
099         *
100         * @param first
101         *            The first transformation to apply to given points.
102         * @param second
103         *            The second transformation to apply to given points.
104         */
105        public ConcatenatedTransform( Transformation first, Transformation second ) {
106            this( first, second, new Identifiable( Transformation.createFromTo( first.getIdentifier(),
107                                                                                second.getIdentifier() ) ) );
108        }
109    
110        @Override
111        public List<Point3d> doTransform( List<Point3d> srcPts )
112                                throws TransformationException {
113            if ( !isIdentitiy ) {
114                List<Point3d> dest = firstTransform.doTransform( srcPts );
115                return secondTransform.doTransform( dest );
116            }
117            return srcPts;
118        }
119    
120        @Override
121        public void inverse() {
122            super.inverse();
123            Transformation tmp = firstTransform;
124            firstTransform = secondTransform;
125            secondTransform = tmp;
126            firstTransform.inverse();
127            secondTransform.inverse();
128        }
129    
130        @Override
131        public boolean isIdentity() {
132            return isIdentitiy;
133        }
134    
135        /**
136         * @return the firstTransform, which is the second transformation if this transform is inverse.
137         */
138        public final Transformation getFirstTransform() {
139            return firstTransform;
140        }
141    
142        /**
143         * @return the secondTransform, which is the first transformation if this transform is inverse.
144         */
145        public final Transformation getSecondTransform() {
146            return secondTransform;
147        }
148    
149        @Override
150        public String getImplementationName() {
151            return "Concatenated-Transform";
152        }
153    
154    }