001 //$HeadURL: svn+ssh://rbezema@svn.wald.intevation.org/deegree/base/branches/2.2_testing/src/org/deegree/io/shpapi/SHP2WKS.java $
002 /*---------------- FILE HEADER ------------------------------------------
003
004 This file is part of deegree.
005 Copyright (C) 2001-2008 by:
006 EXSE, Department of Geography, University of Bonn
007 http://www.giub.uni-bonn.de/deegree/
008 lat/lon GmbH
009 http://www.lat-lon.de
010
011 This library is free software; you can redistribute it and/or
012 modify it under the terms of the GNU Lesser General Public
013 License as published by the Free Software Foundation; either
014 version 2.1 of the License, or (at your option) any later version.
015
016 This library is distributed in the hope that it will be useful,
017 but WITHOUT ANY WARRANTY; without even the implied warranty of
018 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
019 Lesser General Public License for more details.
020
021 You should have received a copy of the GNU Lesser General Public
022 License along with this library; if not, write to the Free Software
023 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
024
025 Contact:
026
027 Andreas Poth
028 lat/lon GmbH
029 Aennchenstr. 19
030 53177 Bonn
031 Germany
032 E-Mail: poth@lat-lon.de
033
034 Prof. Dr. Klaus Greve
035 Department of Geography
036 University of Bonn
037 Meckenheimer Allee 166
038 53115 Bonn
039 Germany
040 E-Mail: greve@giub.uni-bonn.de
041
042
043 ---------------------------------------------------------------------------*/
044 package org.deegree.io.shpapi;
045
046 import java.util.ArrayList;
047
048 import org.deegree.model.crs.CoordinateSystem;
049 import org.deegree.model.spatialschema.Curve;
050 import org.deegree.model.spatialschema.CurveSegment;
051 import org.deegree.model.spatialschema.GeometryFactory;
052 import org.deegree.model.spatialschema.Point;
053 import org.deegree.model.spatialschema.Position;
054 import org.deegree.model.spatialschema.Surface;
055 import org.deegree.model.spatialschema.SurfaceInterpolation;
056 import org.deegree.model.spatialschema.SurfaceInterpolationImpl;
057
058 /**
059 * the class SHP2WKS transforms a polygon structure read from a shape-file<BR>
060 * into a WKSLinearPolygon specified by the sf-specifications<BR>
061 *
062 * @version $Revision: 9342 $
063 * @author <a href="mailto:poth@lat-lon.de">Andreas Poth</a>
064 * @author last edited by: $Author: apoth $
065 *
066 * @version 1.0. $Revision: 9342 $, $Date: 2007-12-27 13:32:57 +0100 (Do, 27 Dez 2007) $
067 *
068 * @since 2.0
069 */
070 public class SHP2WKS {
071
072 /**
073 * method: Point transformPoint(CS_CoordinateSystem srs,<BR>
074 * SHPPoint shppoint))<BR>
075 * transforms a SHPPoint to a WKSGeometry<BR>
076 * gets a point that should be transformed<BR>
077 */
078 public Point transformPoint( CoordinateSystem crs, SHPPoint shppoint ) {
079 return GeometryFactory.createPoint( shppoint.x, shppoint.y, crs );
080 }
081
082 /**
083 * method: Point[] transformMultiPoint(CS_CoordinateSystem srs,<BR>
084 * SHPMultiPoint shpmultipoint))<BR>
085 * transforms a SHPMultiPoint to a WKSGeometry<BR>
086 * gets a multipoint that should be transformed<BR>
087 */
088 public Point[] transformMultiPoint( CoordinateSystem srs, SHPMultiPoint shpmultipoint ) {
089 Point[] gm_points = new Point[shpmultipoint.numPoints];
090
091 for ( int i = 0; i < shpmultipoint.numPoints; i++ )
092 gm_points[i] = GeometryFactory.createPoint( shpmultipoint.points[i].x,
093 shpmultipoint.points[i].y, srs );
094
095 return gm_points;
096 }
097
098 /**
099 * method: Point[][] transformPolyLine(CS_CoordinateSystem srs,<BR>
100 * SHPPolyLine shppolyline))<BR>
101 * transforms a SHPPolyLine to a WKSGeometry<BR>
102 * gets a polyline that should be transformed<BR>
103 */
104 public Curve[] transformPolyLine( CoordinateSystem crs, SHPPolyLine shppolyline ) {
105 Curve[] curve = new Curve[shppolyline.numParts];
106
107 try {
108 for ( int j = 0; j < shppolyline.numParts; j++ ) {
109 Position[] gm_points = new Position[shppolyline.points[j].length];
110
111 for ( int i = 0; i < shppolyline.points[j].length; i++ ) {
112 gm_points[i] = GeometryFactory.createPosition( shppolyline.points[j][i].x,
113 shppolyline.points[j][i].y );
114 }
115
116 CurveSegment cs = GeometryFactory.createCurveSegment( gm_points, crs );
117 curve[j] = GeometryFactory.createCurve( cs );
118 }
119 } catch ( Exception e ) {
120 e.printStackTrace();
121 }
122
123 return curve;
124 }
125
126 /**
127 * method: private boolean isInsideRing(Point[] ring, Point point)<BR>
128 * checks if a point is inside a polygon. the algorithm is taken from:<BR>
129 * http://www.ics.uci.edu/~eppstein/161/960307.html#intest<BR>
130 */
131 private boolean isInsideRing( Position[] ring, Position point ) {
132 int crossings = 0;
133
134 for ( int i = 0; i < ring.length; i++ ) {
135 int z = i + 1;
136
137 if ( ( i + 1 ) >= ring.length ) {
138 z = 0;
139 }
140
141 //check if point.x is between x of vertex i and z of ring
142 if ( ( ring[i].getX() < point.getX() && point.getX() < ring[z].getX() )
143 || ( ring[i].getX() > point.getX() && point.getX() > ring[z].getX() ) ) {
144 double t = ( point.getX() - ring[z].getX() ) / ( ring[i].getX() - ring[z].getX() );
145
146 double cy = ( t * ring[i].getY() ) + ( ( 1 - t ) * ring[z].getY() );
147
148 if ( point.getY() == cy ) { //point is on border of ring
149 return false;
150 } else if ( point.getY() > cy ) { //downwards vertical line through point crosses ring
151 crossings++;
152 }
153 }
154
155 //check if point.x equals x of vertex i of ring while point.y > ring[i].y
156 if ( ( ring[i].getX() == point.getX() ) && ( ring[i].getY() <= point.getY() ) ) {
157
158 if ( ring[i].getY() == point.getY() ) { //point is on border of ring
159 return false;
160 }
161
162 //find next point on ring with different x
163 // (adjacent points in shapefile can have equal x&y)
164 while ( ring[z].getX() == point.getX() ) {
165 if ( z == i ) {
166 return false;
167 }
168 z += 1;
169 if ( z == ring.length ) {
170 z = 0;
171 }
172 }
173
174 //find previous point on ring with different x
175 int zz = i - 1;
176 if ( zz < 0 ) {
177 zz = ring.length - 1;
178 }
179 while ( ring[zz].getX() == point.getX() ) {
180 if ( zz == i ) {
181 return false;
182 }
183 zz -= 1;
184 if ( zz < 0 ) {
185 zz = ring.length - 1;
186 }
187 }
188
189 //if point.x between previous and next x then crossing
190 if ( ring[z].getX() < point.getX() && point.getX() < ring[zz].getX()
191 || ring[z].getX() > point.getX() && point.getX() > ring[zz].getX() ) {
192 crossings++;
193 }
194
195 }
196 }
197
198 if ( ( crossings % 2 ) != 0 ) {
199 return true;
200 }
201 return false;
202 }
203
204 /**
205 * transforms the SHPPolygon to a WKSGeometry<BR>
206 * gets the polygon that should be transformed<BR>
207 */
208 public Surface[] transformPolygon( CoordinateSystem crs, SHPPolygon shppolygon ) {
209 ArrayList<Position[]> all_rings = new ArrayList<Position[]>( shppolygon.numRings );
210 ArrayList<Position[]> outer_rings = new ArrayList<Position[]>( shppolygon.numRings );
211 ArrayList<Position[]> inner_rings = new ArrayList<Position[]>( shppolygon.numRings );
212
213 for ( int i = 0; i < shppolygon.numRings; i++ ) {
214
215 Position[] ring = new Position[shppolygon.rings.points[i].length];
216
217 for ( int k = 0; k < shppolygon.rings.points[i].length; k++ ) {
218 ring[k] = GeometryFactory.createPosition( shppolygon.rings.points[i][k].x,
219 shppolygon.rings.points[i][k].y );
220 }
221 all_rings.add( ring );
222 }
223
224 // for every outer ring
225 for ( int i = 0; i < all_rings.size(); i++ ) {
226 Position[] out_ring = all_rings.get( i );
227
228 boolean inn = false;
229 for ( int j = 0; j < all_rings.size(); j++ ) {
230 if ( i == j )
231 continue;
232 Position[] inring = all_rings.get( j );
233
234 // check if one or more points of a inner ring are
235 // within the actual outer ring
236 try {
237 if ( isInsideRing( inring, out_ring[0] ) ) {
238 inn = true;
239 inner_rings.add( out_ring );
240 break;
241 }
242 } catch ( Exception e ) {
243 e.printStackTrace();
244 }
245
246 }
247 if ( !inn ) {
248 outer_rings.add( out_ring );
249 }
250
251 }
252
253 ArrayList<Surface> wkslp = new ArrayList<Surface>( outer_rings.size() );
254 SurfaceInterpolation si = new SurfaceInterpolationImpl();
255 for ( int i = 0; i < outer_rings.size(); i++ ) {
256 Position[] out_ring = outer_rings.get( i );
257
258 int count = inner_rings.size() - 1;
259 ArrayList<Position[]> list = new ArrayList<Position[]>( count + 2 );
260 // find inner rings of the current outter ring
261 for ( int k = count; k >= 0; k-- ) {
262 Position[] in_ring = inner_rings.get( k );
263 if ( isInsideRing( out_ring, in_ring[0] ) ) {
264 list.add( inner_rings.remove( k ) );
265 }
266 }
267 Position[][] inrings = list.toArray( new Position[list.size()][] );
268
269 try {
270 Surface sur = GeometryFactory.createSurface( out_ring, inrings, si, crs );
271 wkslp.add( sur );
272 } catch ( Exception e ) {
273 e.printStackTrace();
274 }
275
276 }
277
278 return wkslp.toArray( new Surface[wkslp.size()] );
279 }
280 }