001 //$HeadURL: $
002 /*---------------- FILE HEADER ------------------------------------------
003 This file is part of deegree.
004 Copyright (C) 2001-2008 by:
005 Department of Geography, University of Bonn
006 http://www.giub.uni-bonn.de/deegree/
007 lat/lon GmbH
008 http://www.lat-lon.de
009
010 This library is free software; you can redistribute it and/or
011 modify it under the terms of the GNU Lesser General Public
012 License as published by the Free Software Foundation; either
013 version 2.1 of the License, or (at your option) any later version.
014 This library is distributed in the hope that it will be useful,
015 but WITHOUT ANY WARRANTY; without even the implied warranty of
016 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
017 Lesser General Public License for more details.
018 You should have received a copy of the GNU Lesser General Public
019 License along with this library; if not, write to the Free Software
020 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
021 Contact:
022
023 Andreas Poth
024 lat/lon GmbH
025 Aennchenstr. 19
026 53177 Bonn
027 Germany
028 E-Mail: poth@lat-lon.de
029
030 Prof. Dr. Klaus Greve
031 Department of Geography
032 University of Bonn
033 Meckenheimer Allee 166
034 53115 Bonn
035 Germany
036 E-Mail: greve@giub.uni-bonn.de
037 ---------------------------------------------------------------------------*/
038
039 package org.deegree.crs.transformations;
040
041 import java.util.List;
042
043 import javax.vecmath.Point3d;
044
045 /**
046 * The <code>ConcatenatedTransform</code> class allows the connection of two transformations.
047 * <p>
048 * Calling inverse on this transformation will invert the whole underlying transformation chain. For example, if A * (B
049 * *C)=D and D is this transformation calling D.inverse() will result in (C.inverse * B.inverse) * A.inverse.
050 * </p>
051 *
052 * @author <a href="mailto:bezema@lat-lon.de">Rutger Bezema</a>
053 *
054 * @author last edited by: $Author:$
055 *
056 * @version $Revision:$, $Date:$
057 *
058 */
059
060 public class ConcatenatedTransform extends CRSTransformation {
061
062 boolean isIdentitiy = false;
063
064 private CRSTransformation firstTransform;
065
066 private CRSTransformation secondTransform;
067
068 /**
069 * Creates a transform by concatenating two existing transforms. A concatenated transform applies two transforms,
070 * one after the other. The dimension of the output space of the first transform must match the dimension of the
071 * input space in the second transform.
072 *
073 * @param first
074 * The first transformation to apply to given points.
075 * @param second
076 * The second transformation to apply to given points.
077 * @param identifier
078 */
079 public ConcatenatedTransform( CRSTransformation first, CRSTransformation second, String identifier ) {
080 super( first.getSourceCRS(), second.getTargetCRS(), identifier, "Concatenated-Transform", null, null,null );
081 if ( first.isIdentity() && second.isIdentity() ) {
082 isIdentitiy = true;
083 }
084 firstTransform = first;
085 secondTransform = second;
086 }
087
088 /**
089 * Creates a transformation by concatenating two existing transforms. A concatenated transform applies two
090 * transforms, one after the other. The dimension of the output space of the first transform must match the
091 * dimension of the input space in the second transform. This constructor creates an identifier with following form:
092 * <code>
093 * FROM_id1_TO_id2.</code> The name will be generated the same way (with getName() instead).
094 *
095 * @param first
096 * The first transformation to apply to given points.
097 * @param second
098 * The second transformation to apply to given points.
099 * @param identifier
100 * @param name
101 */
102 public ConcatenatedTransform( CRSTransformation first, CRSTransformation second ) {
103 this( first, second, new StringBuilder( "FROM_" ).append( first.getIdentifier() )
104 .append( "_TO_" )
105 .append( second.getIdentifier() )
106 .toString() );
107 }
108
109 @Override
110 public List<Point3d> doTransform( List<Point3d> srcPts ) {
111 if ( !isIdentitiy ) {
112 List<Point3d> dest = firstTransform.doTransform( srcPts );
113 return secondTransform.doTransform( dest );
114 }
115 // System.out.println( "The concatenated transform is identity" );
116 return srcPts;
117 }
118
119 @Override
120 public void inverse() {
121 super.inverse();
122 CRSTransformation tmp = firstTransform;
123 firstTransform = secondTransform;
124 secondTransform = tmp;
125 firstTransform.inverse();
126 secondTransform.inverse();
127 }
128
129 /*
130 * (non-Javadoc)
131 *
132 * @see org.deegree.crs.transformations.CRSTransformation#isIdentity()
133 */
134 @Override
135 public boolean isIdentity() {
136 return isIdentitiy;
137 }
138
139 /**
140 * @return the firstTransform, which is the second transformation if this transform is inverse.
141 */
142 public final CRSTransformation getFirstTransform() {
143 return firstTransform;
144 }
145
146 /**
147 * @return the secondTransform, which is the first transformation if this transform is inverse.
148 */
149 public final CRSTransformation getSecondTransform() {
150 return secondTransform;
151 }
152
153 }