001 //$HeadURL: svn+ssh://rbezema@svn.wald.intevation.org/deegree/base/tags/2.1/src/org/deegree/framework/util/MapUtils.java $
002 /*---------------- FILE HEADER ------------------------------------------
003
004 This file is part of deegree.
005 Copyright (C) 2001-2006 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 53115 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 package org.deegree.framework.util;
044
045 import org.deegree.framework.log.ILogger;
046 import org.deegree.framework.log.LoggerFactory;
047 import org.deegree.i18n.Messages;
048 import org.deegree.model.crs.CRSFactory;
049 import org.deegree.model.crs.CoordinateSystem;
050 import org.deegree.model.crs.GeoTransformer;
051 import org.deegree.model.crs.IGeoTransformer;
052 import org.deegree.model.spatialschema.Envelope;
053 import org.deegree.model.spatialschema.GeometryFactory;
054 import org.deegree.model.spatialschema.Position;
055
056 /**
057 *
058 *
059 * @version $Revision: 6259 $
060 * @author <a href="mailto:poth@lat-lon.de">Andreas Poth</a>
061 * @author last edited by: $Author: bezema $
062 *
063 * @version 1.0. $Revision: 6259 $, $Date: 2007-03-20 10:15:15 +0100 (Di, 20 Mär 2007) $
064 *
065 * @since 2.0
066 */
067 public class MapUtils {
068
069 private static ILogger LOG = LoggerFactory.getLogger( MapUtils.class );
070
071 /**
072 * The Value of sqrt(2)
073 */
074 public static final double SQRT2 = 1.4142135623730950488016887242096980785;
075
076 /**
077 * The Value of a PixelSize
078 */
079 public static final double DEFAULT_PIXEL_SIZE = 0.00028;
080
081 /**
082 * calculates the map scale (denominator) as defined in the OGC SLD 1.0.0
083 * specification
084 *
085 * @param mapWidth map width in pixel
086 * @param mapHeight map height in pixel
087 * @param bbox bounding box of the map
088 * @param crs coordinate reference system of the map
089 * @param pixelSize size of one pixel of the map measured in meter
090 *
091 * @return a maps scale based on the diagonal size of a pixel at the
092 * center of the map in meter.
093 * @throws RuntimeException
094 */
095 public static double calcScale( int mapWidth, int mapHeight, Envelope bbox,
096 CoordinateSystem crs, double pixelSize )
097 throws RuntimeException {
098
099 if( mapWidth == 0 || mapHeight == 0) {
100 return 0;
101 }
102
103 double scale = 0;
104
105 CoordinateSystem cs = crs;
106
107 if ( cs == null ) {
108 throw new RuntimeException( "Invalid crs: " + crs );
109 }
110
111 try {
112 if ( "m".equals( cs.getUnits() ) ) {
113
114 /*
115 this method to calculate a maps scale as defined in OGC WMS
116 and SLD specification is not required for maps having a projected
117 reference system. Direct calculation of scale avoids uncertaincies
118 */
119 // double tmp = Math.pow( mapWidth, 2 ) + Math.pow( mapHeight, 2 );
120 // double d1 = Math.sqrt( tmp );
121 // tmp = Math.pow( bbox.getWidth(), 2 ) + Math.pow( bbox.getHeight(), 2 );
122 // double d2 = Math.sqrt( tmp );
123 // scale = ( d2 / d1 ) / ( pixelSize / SQRT2 );
124 double bboxWidth = bbox.getWidth();
125 double bboxHeight = bbox.getHeight();
126 double d1 = (mapWidth*mapWidth) + (mapHeight*mapHeight); //Math.sqrt( tmp );
127 double d2 = (bboxWidth*bboxWidth) + (bboxHeight*bboxHeight);//Math.sqrt( tmp );
128 scale = Math.sqrt( d2 / d1 ) * ( SQRT2 / pixelSize );
129
130 } else {
131
132 if ( !crs.getName().equalsIgnoreCase( "EPSG:4326" ) ) {
133 // transform the bounding box of the request to EPSG:4326
134 IGeoTransformer trans = new GeoTransformer( CRSFactory.create( "EPSG:4326" ) );
135 bbox = trans.transform( bbox, crs );
136 }
137 double dx = bbox.getWidth() / mapWidth;
138 double dy = bbox.getHeight() / mapHeight;
139 Position min = GeometryFactory.createPosition( bbox.getMin().getX()
140 + dx * ( mapWidth / 2d - 1 ),
141 bbox.getMin().getY()
142 + dy * ( mapHeight / 2d - 1 ) );
143 Position max = GeometryFactory.createPosition( bbox.getMin().getX()
144 + dx * ( mapWidth / 2d ),
145 bbox.getMin().getY()
146 + dy * ( mapHeight / 2d ) );
147
148 double distance = calcDistance( min.getX(), min.getY(), max.getX(), max.getY() );
149
150 scale = distance * ( SQRT2 / pixelSize );
151
152 }
153 } catch ( Exception e ) {
154 LOG.logError( e.getMessage(), e );
155 throw new RuntimeException( Messages.getMessage( "FRAMEWORK_ERROR_SCALE_CALC", e.getMessage() ) );
156 }
157
158 return scale;
159
160 }
161
162 /**
163 * calculates the distance in meters between two points in EPSG:4326 coodinates.
164 * this is a convenience method assuming the world is a ball
165 * @param lon1
166 * @param lat1
167 * @param lon2
168 * @param lat2
169 * @return the distance in meters between two points in EPSG:4326 coords
170 */
171 public static double calcDistance( double lon1, double lat1, double lon2, double lat2 ) {
172 double r = 6378.137;
173 double rad = Math.PI / 180d;
174 double cose = Math.sin( rad * lon1 ) * Math.sin( rad * lon2 ) + Math.cos( rad * lon1 )
175 * Math.cos( rad * lon2 ) * Math.cos( rad * ( lat1 - lat2 ) );
176 double dist = r * Math.acos( cose ) * Math.cos( rad * Math.min( lat1, lat2 ) ) ;
177
178 // * 0.75 is just an heuristic correction factor
179 return dist * 1000 * 0.75;
180 }
181
182
183 /**
184 * The method calculates a new Envelope from the <code>requestedBarValue</code> It will either
185 * zoom in or zoom out of the <code>actualBBOX<code> depending
186 * on the ratio of the <code>requestedBarValue</code> to the <code>actualBarValue</code>
187 * @param currentEnvelope current Envelope
188 * @param currentScale the scale of the current envelope
189 * @param requestedScale requested scale value
190 * @return a new Envelope
191 */
192 public static Envelope scaleEnvelope( Envelope currentEnvelope, double currentScale,
193 double requestedScale ) {
194
195 double ratio = requestedScale / currentScale;
196 double newWidth = currentEnvelope.getWidth() * ratio;
197 double newHeight = currentEnvelope.getHeight() * ratio;
198 double midX = currentEnvelope.getMin().getX() + ( currentEnvelope.getWidth() / 2d );
199 double midY = currentEnvelope.getMin().getY() + ( currentEnvelope.getHeight() / 2d );
200
201 double minx = midX - newWidth / 2d;
202 double maxx = midX + newWidth / 2d;
203 double miny = midY - newHeight / 2d;
204 double maxy = midY + newHeight / 2d;
205
206 return GeometryFactory.createEnvelope( minx, miny, maxx, maxy,
207 currentEnvelope.getCoordinateSystem() );
208
209 }
210
211 /**
212 * This method ensures the bbox is resized (shrunk) to match the aspect ratio defined by
213 * mapHeight/mapWidth
214 *
215 * @param bbox
216 * @param mapWith
217 * @param mapHeight
218 * @return a new bounding box with the aspect ratio given my mapHeight/mapWidth
219 */
220 public static final Envelope ensureAspectRatio( Envelope bbox, double mapWith, double mapHeight ) {
221
222 double minx = bbox.getMin().getX();
223 double miny = bbox.getMin().getY();
224 double maxx = bbox.getMax().getX();
225 double maxy = bbox.getMax().getY();
226
227 double dx = maxx - minx;
228 double dy = maxy - miny;
229
230 double ratio = mapHeight / mapWith;
231
232 if ( dx >= dy ) {
233 // height has to be corrected
234 double[] normCoords = getNormalizedCoords( dx, ratio, miny, maxy );
235 miny = normCoords[0];
236 maxy = normCoords[1];
237 } else {
238 // width has to be corrected
239 ratio = mapWith / mapHeight;
240 double[] normCoords = getNormalizedCoords( dy, ratio, minx, maxx );
241 minx = normCoords[0];
242 maxx = normCoords[1];
243 }
244 CoordinateSystem crs = bbox.getCoordinateSystem();
245
246 return GeometryFactory.createEnvelope( minx, miny, maxx, maxy, crs );
247 }
248
249 private static final double[] getNormalizedCoords( double normLen, double ratio, double min,
250 double max ) {
251 double mid = ( max - min ) / 2 + min;
252 min = mid - ( normLen / 2 ) * ratio;
253 max = mid + ( normLen / 2 ) * ratio;
254 double[] newCoords = { min, max };
255 return newCoords;
256 }
257
258 }
259
260 /* ********************************************************************
261 Changes to this class. What the people have been up to:
262 $Log$
263 Revision 1.8 2006/12/13 16:07:06 mays
264 bugfix in scaleEnvelope: change from getWidth() to getHeight() for Y-coordinates
265
266 Revision 1.7 2006/11/28 13:44:56 mays
267 add method ensureAspectRatio() and depending method getNormalizedCoords()
268
269 Revision 1.6 2006/11/27 09:07:52 poth
270 JNI integration of proj4 has been removed. The CRS functionality now will be done by native deegree code.
271
272 Revision 1.5 2006/11/26 19:02:54 poth
273 bug fix
274
275 Revision 1.4 2006/11/26 18:48:16 poth
276 bug fix
277
278 Revision 1.3 2006/11/23 08:25:14 bezema
279 changed the scale calculation to be faster, added a SQRT2 and a PIXELSIZE field
280
281 Revision 1.1 2006/10/17 20:31:19 poth
282 *** empty log message ***
283
284 Revision 1.23 2006/09/27 16:46:41 poth
285 transformation method signature changed
286
287 Revision 1.22 2006/09/26 14:21:17 poth
288 bug fix
289
290 Revision 1.21 2006/09/26 13:31:11 poth
291 bug fix
292
293 Revision 1.20 2006/09/26 13:29:55 poth
294 bug fix
295
296 Revision 1.19 2006/09/26 13:16:43 poth
297 LOG statement added
298
299 Revision 1.18 2006/09/25 20:28:53 poth
300 bug fixes - map scale calculation
301
302 Revision 1.17 2006/09/25 12:47:00 poth
303 bug fixes - map scale calculation
304
305 Revision 1.16 2006/09/22 09:07:58 taddei
306 refactored: added scaleEnvelope to this class, becaus it used by many classes
307
308 Revision 1.15 2006/09/18 12:37:22 bezema
309 fixed a division by null
310
311 Revision 1.14 2006/07/28 09:24:39 poth
312 bug fix - calculating geographic distance
313
314 Revision 1.13 2006/07/25 06:21:53 poth
315 bug fix - calculating map scale
316
317 Revision 1.12 2006/07/11 13:47:52 bezema
318 changed the throws exception to throws RuntimeException
319
320 Revision 1.11 2006/07/11 13:39:02 taddei
321 *** empty log message ***
322
323 Revision 1.10 2006/05/31 12:19:34 poth
324 *** empty log message ***
325
326 Revision 1.9 2006/05/31 11:57:37 poth
327 bug fix - pixel size considered
328
329 Revision 1.8 2006/05/31 09:17:05 ncho
330 SN: calcDistance-changed private to public
331 and added NullPointerException
332
333 Revision 1.7 2006/05/03 20:09:52 poth
334 *** empty log message ***
335
336 Revision 1.6 2006/05/01 20:15:27 poth
337 *** empty log message ***
338
339 Revision 1.5 2006/04/06 20:25:28 poth
340 *** empty log message ***
341
342 Revision 1.4 2006/03/30 21:20:27 poth
343 *** empty log message ***
344
345 Revision 1.3 2005/08/19 07:45:11 poth
346 no message
347
348 Revision 1.2 2005/08/05 09:42:20 poth
349 no message
350
351 Revision 1.1 2005/07/30 18:11:20 poth
352 no message
353
354
355 ********************************************************************** */