001 //$HeadURL: https://svn.wald.intevation.org/svn/deegree/base/branches/2.3_testing/src/org/deegree/io/shpapi/SHP2WKS.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 package org.deegree.io.shpapi;
037
038 import java.util.ArrayList;
039
040 import org.deegree.model.crs.CoordinateSystem;
041 import org.deegree.model.spatialschema.Curve;
042 import org.deegree.model.spatialschema.CurveSegment;
043 import org.deegree.model.spatialschema.GeometryFactory;
044 import org.deegree.model.spatialschema.Point;
045 import org.deegree.model.spatialschema.Position;
046 import org.deegree.model.spatialschema.Surface;
047 import org.deegree.model.spatialschema.SurfaceInterpolation;
048 import org.deegree.model.spatialschema.SurfaceInterpolationImpl;
049
050 /**
051 * the class SHP2WKS transforms a polygon structure read from a shape-file<BR>
052 * into a WKSLinearPolygon specified by the sf-specifications<BR>
053 *
054 * @version $Revision: 18195 $
055 * @author <a href="mailto:poth@lat-lon.de">Andreas Poth</a>
056 * @author last edited by: $Author: mschneider $
057 *
058 * @version 1.0. $Revision: 18195 $, $Date: 2009-06-18 17:55:39 +0200 (Do, 18. Jun 2009) $
059 *
060 * @since 2.0
061 */
062 public class SHP2WKS {
063
064 /**
065 * method: Point transformPoint(CS_CoordinateSystem srs,<BR>
066 * SHPPoint shppoint))<BR>
067 * transforms a SHPPoint to a WKSGeometry<BR>
068 * gets a point that should be transformed<BR>
069 *
070 * @param crs
071 * @param shppoint
072 * @return the transformed point
073 */
074 public Point transformPoint( CoordinateSystem crs, SHPPoint shppoint ) {
075 return GeometryFactory.createPoint( shppoint.x, shppoint.y, crs );
076 }
077
078 /**
079 * method: Point[] transformMultiPoint(CS_CoordinateSystem srs,<BR>
080 * SHPMultiPoint shpmultipoint))<BR>
081 * transforms a SHPMultiPoint to a WKSGeometry<BR>
082 * gets a multipoint that should be transformed<BR>
083 *
084 * @param srs
085 * @param shpmultipoint
086 * @return the transformed points
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, shpmultipoint.points[i].y, srs );
093
094 return gm_points;
095 }
096
097 /**
098 * method: Point[][] transformPolyLine(CS_CoordinateSystem srs,<BR>
099 * SHPPolyLine shppolyline))<BR>
100 * transforms a SHPPolyLine to a WKSGeometry<BR>
101 * gets a polyline that should be transformed<BR>
102 *
103 * @param crs
104 * @param shppolyline
105 * @return the transformed line
106 */
107 public Curve[] transformPolyLine( CoordinateSystem crs, SHPPolyLine shppolyline ) {
108 Curve[] curve = new Curve[shppolyline.numParts];
109
110 try {
111 for ( int j = 0; j < shppolyline.numParts; j++ ) {
112 Position[] gm_points = new Position[shppolyline.points[j].length];
113
114 for ( int i = 0; i < shppolyline.points[j].length; i++ ) {
115 gm_points[i] = GeometryFactory.createPosition( shppolyline.points[j][i].x,
116 shppolyline.points[j][i].y );
117 }
118
119 CurveSegment cs = GeometryFactory.createCurveSegment( gm_points, crs );
120 curve[j] = GeometryFactory.createCurve( cs );
121 }
122 } catch ( Exception e ) {
123 e.printStackTrace();
124 }
125
126 return curve;
127 }
128
129 /**
130 * method: private boolean isInsideRing(Point[] ring, Point point)<BR>
131 * checks if a point is inside a polygon. the algorithm is taken from:<BR>
132 * http://www.ics.uci.edu/~eppstein/161/960307.html#intest<BR>
133 */
134 private boolean isInsideRing( Position[] ring, Position point ) {
135 int crossings = 0;
136
137 for ( int i = 0; i < ring.length; i++ ) {
138 int z = i + 1;
139
140 if ( ( i + 1 ) >= ring.length ) {
141 z = 0;
142 }
143
144 // check if point.x is between x of vertex i and z of ring
145 if ( ( ring[i].getX() < point.getX() && point.getX() < ring[z].getX() )
146 || ( ring[i].getX() > point.getX() && point.getX() > ring[z].getX() ) ) {
147 double t = ( point.getX() - ring[z].getX() ) / ( ring[i].getX() - ring[z].getX() );
148
149 double cy = ( t * ring[i].getY() ) + ( ( 1 - t ) * ring[z].getY() );
150
151 if ( point.getY() == cy ) { // point is on border of ring
152 return false;
153 } else if ( point.getY() > cy ) { // downwards vertical line through point crosses
154 // ring
155 crossings++;
156 }
157 }
158
159 // check if point.x equals x of vertex i of ring while point.y > ring[i].y
160 if ( ( ring[i].getX() == point.getX() ) && ( ring[i].getY() <= point.getY() ) ) {
161
162 if ( ring[i].getY() == point.getY() ) { // point is on border of ring
163 return false;
164 }
165
166 // find next point on ring with different x
167 // (adjacent points in shapefile can have equal x&y)
168 while ( ring[z].getX() == point.getX() ) {
169 if ( z == i ) {
170 return false;
171 }
172 z += 1;
173 if ( z == ring.length ) {
174 z = 0;
175 }
176 }
177
178 // find previous point on ring with different x
179 int zz = i - 1;
180 if ( zz < 0 ) {
181 zz = ring.length - 1;
182 }
183 while ( ring[zz].getX() == point.getX() ) {
184 if ( zz == i ) {
185 return false;
186 }
187 zz -= 1;
188 if ( zz < 0 ) {
189 zz = ring.length - 1;
190 }
191 }
192
193 // if point.x between previous and next x then crossing
194 if ( ring[z].getX() < point.getX() && point.getX() < ring[zz].getX() || ring[z].getX() > point.getX()
195 && point.getX() > ring[zz].getX() ) {
196 crossings++;
197 }
198
199 }
200 }
201
202 if ( ( crossings % 2 ) != 0 ) {
203 return true;
204 }
205 return false;
206 }
207
208 /**
209 * transforms the SHPPolygon to a WKSGeometry<BR>
210 * gets the polygon that should be transformed<BR>
211 *
212 * @param crs
213 * @param shppolygon
214 * @return the transformed polygon
215 */
216 public Surface[] transformPolygon( CoordinateSystem crs, SHPPolygon shppolygon ) {
217 ArrayList<Position[]> all_rings = new ArrayList<Position[]>( shppolygon.numRings );
218 ArrayList<Position[]> outer_rings = new ArrayList<Position[]>( shppolygon.numRings );
219 ArrayList<Position[]> inner_rings = new ArrayList<Position[]>( shppolygon.numRings );
220
221 for ( int i = 0; i < shppolygon.numRings; i++ ) {
222
223 Position[] ring = new Position[shppolygon.rings.points[i].length];
224
225 for ( int k = 0; k < shppolygon.rings.points[i].length; k++ ) {
226 ring[k] = GeometryFactory.createPosition( shppolygon.rings.points[i][k].x,
227 shppolygon.rings.points[i][k].y );
228 }
229 all_rings.add( ring );
230 }
231
232 // for every outer ring
233 for ( int i = 0; i < all_rings.size(); i++ ) {
234 Position[] out_ring = all_rings.get( i );
235
236 boolean inn = false;
237 for ( int j = 0; j < all_rings.size(); j++ ) {
238 if ( i == j )
239 continue;
240 Position[] inring = all_rings.get( j );
241
242 // check if one or more points of a inner ring are
243 // within the actual outer ring
244 try {
245 if ( isInsideRing( inring, out_ring[0] ) ) {
246 inn = true;
247 inner_rings.add( out_ring );
248 break;
249 }
250 } catch ( Exception e ) {
251 e.printStackTrace();
252 }
253
254 }
255 if ( !inn ) {
256 outer_rings.add( out_ring );
257 }
258
259 }
260
261 ArrayList<Surface> wkslp = new ArrayList<Surface>( outer_rings.size() );
262 SurfaceInterpolation si = new SurfaceInterpolationImpl();
263 for ( int i = 0; i < outer_rings.size(); i++ ) {
264 Position[] out_ring = outer_rings.get( i );
265
266 int count = inner_rings.size() - 1;
267 ArrayList<Position[]> list = new ArrayList<Position[]>( count + 2 );
268 // find inner rings of the current outter ring
269 for ( int k = count; k >= 0; k-- ) {
270 Position[] in_ring = inner_rings.get( k );
271 if ( isInsideRing( out_ring, in_ring[0] ) ) {
272 list.add( inner_rings.remove( k ) );
273 }
274 }
275 Position[][] inrings = list.toArray( new Position[list.size()][] );
276
277 try {
278 Surface sur = GeometryFactory.createSurface( out_ring, inrings, si, crs );
279 wkslp.add( sur );
280 } catch ( Exception e ) {
281 e.printStackTrace();
282 }
283
284 }
285
286 return wkslp.toArray( new Surface[wkslp.size()] );
287 }
288 }