001 // License: GPL. Copyright 2007 by Immanuel Scholz and others
002 package org.openstreetmap.josm.data.coor;
003
004 import static java.lang.Math.PI;
005 import static java.lang.Math.asin;
006 import static java.lang.Math.atan2;
007 import static java.lang.Math.cos;
008 import static java.lang.Math.sin;
009 import static java.lang.Math.sqrt;
010 import static java.lang.Math.toRadians;
011 import static org.openstreetmap.josm.tools.I18n.trc;
012
013 import java.text.DecimalFormat;
014 import java.text.NumberFormat;
015 import java.util.Locale;
016
017 import org.openstreetmap.josm.Main;
018 import org.openstreetmap.josm.data.Bounds;
019
020 /**
021 * LatLon are unprojected latitude / longitude coordinates.
022 *
023 * This class is immutable.
024 *
025 * @author Imi
026 */
027 public class LatLon extends Coordinate {
028
029
030 /**
031 * Minimum difference in location to not be represented as the same position.
032 * The API returns 7 decimals.
033 */
034 public static final double MAX_SERVER_PRECISION = 1e-7;
035 public static final double MAX_SERVER_INV_PRECISION = 1e7;
036 public static final int MAX_SERVER_DIGITS = 7;
037
038 private static DecimalFormat cDmsMinuteFormatter = new DecimalFormat("00");
039 private static DecimalFormat cDmsSecondFormatter = new DecimalFormat("00.0");
040 private static DecimalFormat cDmMinuteFormatter = new DecimalFormat("00.000");
041 public static final DecimalFormat cDdFormatter;
042 static {
043 // Don't use the localized decimal separator. This way we can present
044 // a comma separated list of coordinates.
045 cDdFormatter = (DecimalFormat) NumberFormat.getInstance(Locale.UK);
046 cDdFormatter.applyPattern("###0.0######");
047 }
048
049 private static final String cDms60 = cDmsSecondFormatter.format(60.0);
050 private static final String cDms00 = cDmsSecondFormatter.format( 0.0);
051 private static final String cDm60 = cDmMinuteFormatter.format(60.0);
052 private static final String cDm00 = cDmMinuteFormatter.format( 0.0);
053
054 /**
055 * Replies true if lat is in the range [-90,90]
056 *
057 * @param lat the latitude
058 * @return true if lat is in the range [-90,90]
059 */
060 public static boolean isValidLat(double lat) {
061 return lat >= -90d && lat <= 90d;
062 }
063
064 /**
065 * Replies true if lon is in the range [-180,180]
066 *
067 * @param lon the longitude
068 * @return true if lon is in the range [-180,180]
069 */
070 public static boolean isValidLon(double lon) {
071 return lon >= -180d && lon <= 180d;
072 }
073
074 /**
075 * Replies true if lat is in the range [-90,90] and lon is in the range [-180,180]
076 *
077 * @return true if lat is in the range [-90,90] and lon is in the range [-180,180]
078 */
079 public boolean isValid() {
080 return isValidLat(lat()) && isValidLon(lon());
081 }
082
083 public static double toIntervalLat(double value) {
084 if (value < -90)
085 return -90;
086 if (value > 90)
087 return 90;
088 return value;
089 }
090
091 /**
092 * Returns a valid OSM longitude [-180,+180] for the given extended longitude value.
093 * For example, a value of -181 will return +179, a value of +181 will return -179.
094 * @param lon A longitude value not restricted to the [-180,+180] range.
095 */
096 public static double toIntervalLon(double value) {
097 if (isValidLon(value))
098 return value;
099 else {
100 int n = (int) (value + Math.signum(value)*180.0) / 360;
101 return value - n*360.0;
102 }
103 }
104
105 /**
106 * Replies the coordinate in degrees/minutes/seconds format
107 * @param pCoordinate The coordinate to convert
108 * @return The coordinate in degrees/minutes/seconds format
109 */
110 public static String dms(double pCoordinate) {
111
112 double tAbsCoord = Math.abs(pCoordinate);
113 int tDegree = (int) tAbsCoord;
114 double tTmpMinutes = (tAbsCoord - tDegree) * 60;
115 int tMinutes = (int) tTmpMinutes;
116 double tSeconds = (tTmpMinutes - tMinutes) * 60;
117
118 String sDegrees = Integer.toString(tDegree);
119 String sMinutes = cDmsMinuteFormatter.format(tMinutes);
120 String sSeconds = cDmsSecondFormatter.format(tSeconds);
121
122 if (sSeconds.equals(cDms60)) {
123 sSeconds = cDms00;
124 sMinutes = cDmsMinuteFormatter.format(tMinutes+1);
125 }
126 if (sMinutes.equals("60")) {
127 sMinutes = "00";
128 sDegrees = Integer.toString(tDegree+1);
129 }
130
131 return sDegrees + "\u00B0" + sMinutes + "\'" + sSeconds + "\"";
132 }
133
134 /**
135 * Replies the coordinate in degrees/minutes format
136 * @param pCoordinate The coordinate to convert
137 * @return The coordinate in degrees/minutes format
138 */
139 public static String dm(double pCoordinate) {
140
141 double tAbsCoord = Math.abs(pCoordinate);
142 int tDegree = (int) tAbsCoord;
143 double tMinutes = (tAbsCoord - tDegree) * 60;
144
145 String sDegrees = Integer.toString(tDegree);
146 String sMinutes = cDmMinuteFormatter.format(tMinutes);
147
148 if (sMinutes.equals(cDm60)) {
149 sMinutes = cDm00;
150 sDegrees = Integer.toString(tDegree+1);
151 }
152
153 return sDegrees + "\u00B0" + sMinutes + "\'";
154 }
155
156 public LatLon(double lat, double lon) {
157 super(lon, lat);
158 }
159
160 public LatLon(LatLon coor) {
161 super(coor.lon(), coor.lat());
162 }
163
164 public double lat() {
165 return y;
166 }
167
168 public final static String SOUTH = trc("compass", "S");
169 public final static String NORTH = trc("compass", "N");
170 public String latToString(CoordinateFormat d) {
171 switch(d) {
172 case DECIMAL_DEGREES: return cDdFormatter.format(y);
173 case DEGREES_MINUTES_SECONDS: return dms(y) + ((y < 0) ? SOUTH : NORTH);
174 case NAUTICAL: return dm(y) + ((y < 0) ? SOUTH : NORTH);
175 case EAST_NORTH: return cDdFormatter.format(Main.getProjection().latlon2eastNorth(this).north());
176 default: return "ERR";
177 }
178 }
179
180 public double lon() {
181 return x;
182 }
183
184 public final static String WEST = trc("compass", "W");
185 public final static String EAST = trc("compass", "E");
186 public String lonToString(CoordinateFormat d) {
187 switch(d) {
188 case DECIMAL_DEGREES: return cDdFormatter.format(x);
189 case DEGREES_MINUTES_SECONDS: return dms(x) + ((x < 0) ? WEST : EAST);
190 case NAUTICAL: return dm(x) + ((x < 0) ? WEST : EAST);
191 case EAST_NORTH: return cDdFormatter.format(Main.getProjection().latlon2eastNorth(this).east());
192 default: return "ERR";
193 }
194 }
195
196 /**
197 * @return <code>true</code> if the other point has almost the same lat/lon
198 * values, only differing by no more than
199 * 1 / {@link #MAX_SERVER_PRECISION MAX_SERVER_PRECISION}.
200 */
201 public boolean equalsEpsilon(LatLon other) {
202 double p = MAX_SERVER_PRECISION / 2;
203 return Math.abs(lat()-other.lat()) <= p && Math.abs(lon()-other.lon()) <= p;
204 }
205
206 /**
207 * @return <code>true</code>, if the coordinate is outside the world, compared
208 * by using lat/lon.
209 */
210 public boolean isOutSideWorld() {
211 Bounds b = Main.getProjection().getWorldBoundsLatLon();
212 return lat() < b.getMin().lat() || lat() > b.getMax().lat() ||
213 lon() < b.getMin().lon() || lon() > b.getMax().lon();
214 }
215
216 /**
217 * @return <code>true</code> if this is within the given bounding box.
218 */
219 public boolean isWithin(Bounds b) {
220 return b.contains(this);
221 }
222
223 /**
224 * Computes the distance between this lat/lon and another point on the earth.
225 * Uses Haversine formular.
226 * @param other the other point.
227 * @return distance in metres.
228 */
229 public double greatCircleDistance(LatLon other) {
230 double R = 6378135;
231 double sinHalfLat = sin(toRadians(other.lat() - this.lat()) / 2);
232 double sinHalfLon = sin(toRadians(other.lon() - this.lon()) / 2);
233 double d = 2 * R * asin(
234 sqrt(sinHalfLat*sinHalfLat +
235 cos(toRadians(this.lat()))*cos(toRadians(other.lat()))*sinHalfLon*sinHalfLon));
236 // For points opposite to each other on the sphere,
237 // rounding errors could make the argument of asin greater than 1
238 // (This should almost never happen.)
239 if (java.lang.Double.isNaN(d)) {
240 System.err.println("Error: NaN in greatCircleDistance");
241 d = PI * R;
242 }
243 return d;
244 }
245
246 /**
247 * Returns the heading, in radians, that you have to use to get from
248 * this lat/lon to another.
249 *
250 * (I don't know the original source of this formula, but see
251 * http://math.stackexchange.com/questions/720/how-to-calculate-a-heading-on-the-earths-surface
252 * for some hints how it is derived.)
253 *
254 * @param other the "destination" position
255 * @return heading in the range 0 <= hd < 2*PI
256 */
257 public double heading(LatLon other) {
258 double hd = atan2(sin(toRadians(this.lon() - other.lon())) * cos(toRadians(other.lat())),
259 cos(toRadians(this.lat())) * sin(toRadians(other.lat())) -
260 sin(toRadians(this.lat())) * cos(toRadians(other.lat())) * cos(toRadians(this.lon() - other.lon())));
261 hd %= 2 * PI;
262 if (hd < 0) {
263 hd += 2 * PI;
264 }
265 return hd;
266 }
267
268 /**
269 * Returns this lat/lon pair in human-readable format.
270 *
271 * @return String in the format "lat=1.23456 deg, lon=2.34567 deg"
272 */
273 public String toDisplayString() {
274 NumberFormat nf = NumberFormat.getInstance();
275 nf.setMaximumFractionDigits(5);
276 return "lat=" + nf.format(lat()) + "\u00B0, lon=" + nf.format(lon()) + "\u00B0";
277 }
278
279 public LatLon interpolate(LatLon ll2, double proportion) {
280 return new LatLon(this.lat() + proportion * (ll2.lat() - this.lat()),
281 this.lon() + proportion * (ll2.lon() - this.lon()));
282 }
283
284 public LatLon getCenter(LatLon ll2) {
285 return new LatLon((this.lat() + ll2.lat())/2.0, (this.lon() + ll2.lon())/2.0);
286 }
287
288 @Override public String toString() {
289 return "LatLon[lat="+lat()+",lon="+lon()+"]";
290 }
291
292 /**
293 * Returns the value rounded to OSM precisions, i.e. to
294 * LatLon.MAX_SERVER_PRECISION
295 *
296 * @return rounded value
297 */
298 public static double roundToOsmPrecision(double value) {
299 return Math.round(value * MAX_SERVER_INV_PRECISION) / MAX_SERVER_INV_PRECISION;
300 }
301
302 /**
303 * Returns the value rounded to OSM precision. This function is now the same as
304 * {@link #roundToOsmPrecision(double)}, since the rounding error has been fixed.
305 *
306 * @return rounded value
307 */
308 public static double roundToOsmPrecisionStrict(double value) {
309 return roundToOsmPrecision(value);
310 }
311
312 /**
313 * Replies a clone of this lat LatLon, rounded to OSM precisions, i.e. to
314 * MAX_SERVER_PRECISION
315 *
316 * @return a clone of this lat LatLon
317 */
318 public LatLon getRoundedToOsmPrecision() {
319 return new LatLon(
320 roundToOsmPrecision(lat()),
321 roundToOsmPrecision(lon())
322 );
323 }
324
325 /**
326 * Replies a clone of this lat LatLon, rounded to OSM precisions, i.e. to
327 * MAX_SERVER_PRECISION
328 *
329 * @return a clone of this lat LatLon
330 */
331 public LatLon getRoundedToOsmPrecisionStrict() {
332 return new LatLon(
333 roundToOsmPrecisionStrict(lat()),
334 roundToOsmPrecisionStrict(lon())
335 );
336 }
337
338 @Override
339 public int hashCode() {
340 final int prime = 31;
341 int result = super.hashCode();
342 long temp;
343 temp = java.lang.Double.doubleToLongBits(x);
344 result = prime * result + (int) (temp ^ (temp >>> 32));
345 temp = java.lang.Double.doubleToLongBits(y);
346 result = prime * result + (int) (temp ^ (temp >>> 32));
347 return result;
348 }
349
350 @Override
351 public boolean equals(Object obj) {
352 if (this == obj)
353 return true;
354 if (!super.equals(obj))
355 return false;
356 if (getClass() != obj.getClass())
357 return false;
358 Coordinate other = (Coordinate) obj;
359 if (java.lang.Double.doubleToLongBits(x) != java.lang.Double.doubleToLongBits(other.x))
360 return false;
361 if (java.lang.Double.doubleToLongBits(y) != java.lang.Double.doubleToLongBits(other.y))
362 return false;
363 return true;
364 }
365 }