1 // Copyright (C) 2006 Mathias Froehlich - Mathias.Froehlich@web.de
3 // This library is free software; you can redistribute it and/or
4 // modify it under the terms of the GNU Library General Public
5 // License as published by the Free Software Foundation; either
6 // version 2 of the License, or (at your option) any later version.
8 // This library is distributed in the hope that it will be useful,
9 // but WITHOUT ANY WARRANTY; without even the implied warranty of
10 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 // Library General Public License for more details.
13 // You should have received a copy of the GNU General Public License
14 // along with this program; if not, write to the Free Software
15 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
21 #include <simgear/constants.h>
23 // #define SG_GEOD_NATIVE_DEGREE
25 /// Class representing a geodetic location
28 /// Default constructor, initializes the instance to lat = lon = elev = 0
31 /// Factory from angular values in radians and elevation is 0
32 static SGGeod fromRad(double lon, double lat);
33 /// Factory from angular values in degrees and elevation is 0
34 static SGGeod fromDeg(double lon, double lat);
35 /// Factory from angular values in radians and elevation in ft
36 static SGGeod fromRadFt(double lon, double lat, double elevation);
37 /// Factory from angular values in degrees and elevation in ft
38 static SGGeod fromDegFt(double lon, double lat, double elevation);
39 /// Factory from angular values in radians and elevation in m
40 static SGGeod fromRadM(double lon, double lat, double elevation);
41 /// Factory from angular values in degrees and elevation in m
42 static SGGeod fromDegM(double lon, double lat, double elevation);
43 /// Factory from an other SGGeod and a different elevation in m
44 static SGGeod fromGeodM(const SGGeod& geod, double elevation);
45 /// Factory from an other SGGeod and a different elevation in ft
46 static SGGeod fromGeodFt(const SGGeod& geod, double elevation);
47 /// Factory to convert position from a cartesian position assumed to be
48 /// in wgs84 measured in meters
49 /// Note that this conversion is relatively expensive to compute
50 static SGGeod fromCart(const SGVec3<double>& cart);
51 /// Factory to convert position from a geocentric position
52 /// Note that this conversion is relatively expensive to compute
53 static SGGeod fromGeoc(const SGGeoc& geoc);
55 /// Return the geodetic longitude in radians
56 double getLongitudeRad(void) const;
57 /// Set the geodetic longitude from the argument given in radians
58 void setLongitudeRad(double lon);
60 /// Return the geodetic longitude in degrees
61 double getLongitudeDeg(void) const;
62 /// Set the geodetic longitude from the argument given in degrees
63 void setLongitudeDeg(double lon);
65 /// Return the geodetic latitude in radians
66 double getLatitudeRad(void) const;
67 /// Set the geodetic latitude from the argument given in radians
68 void setLatitudeRad(double lat);
70 /// Return the geodetic latitude in degrees
71 double getLatitudeDeg(void) const;
72 /// Set the geodetic latitude from the argument given in degrees
73 void setLatitudeDeg(double lat);
75 /// Return the geodetic elevation in meters
76 double getElevationM(void) const;
77 /// Set the geodetic elevation from the argument given in meters
78 void setElevationM(double elevation);
80 /// Return the geodetic elevation in feet
81 double getElevationFt(void) const;
82 /// Set the geodetic elevation from the argument given in feet
83 void setElevationFt(double elevation);
85 /// Compare two geodetic positions for equality
86 bool operator == ( const SGGeod & other ) const;
88 /// check the Geod contains sane values (finite, inside appropriate
89 /// ranges for lat/lon)
92 /// This one is private since construction is not unique if you do
93 /// not know the units of the arguments. Use the factory methods for
95 SGGeod(double lon, double lat, double elevation);
97 //// FIXME: wrong comment!
98 /// The actual data, angles in degrees, elevation in meters
99 /// The rationale for storing the values in degrees is that most code places
100 /// in flightgear/terragear use degrees as a nativ input and output value.
101 /// The places where it makes sense to use radians is when we convert
102 /// to other representations or compute rotation matrices. But both tasks
103 /// are computionally intensive anyway and that additional 'toRadian'
104 /// conversion does not hurt too much
111 SGGeod::SGGeod(void) :
112 _lon(0), _lat(0), _elevation(0)
117 SGGeod::SGGeod(double lon, double lat, double elevation) :
118 _lon(lon), _lat(lat), _elevation(elevation)
124 SGGeod::fromRad(double lon, double lat)
126 #ifdef SG_GEOD_NATIVE_DEGREE
127 return SGGeod(lon*SGD_RADIANS_TO_DEGREES, lat*SGD_RADIANS_TO_DEGREES, 0);
129 return SGGeod(lon, lat, 0);
135 SGGeod::fromDeg(double lon, double lat)
137 #ifdef SG_GEOD_NATIVE_DEGREE
138 return SGGeod(lon, lat, 0);
140 return SGGeod(lon*SGD_DEGREES_TO_RADIANS, lat*SGD_DEGREES_TO_RADIANS, 0);
146 SGGeod::fromRadFt(double lon, double lat, double elevation)
148 #ifdef SG_GEOD_NATIVE_DEGREE
149 return SGGeod(lon*SGD_RADIANS_TO_DEGREES, lat*SGD_RADIANS_TO_DEGREES,
150 elevation*SG_FEET_TO_METER);
152 return SGGeod(lon, lat, elevation*SG_FEET_TO_METER);
158 SGGeod::fromDegFt(double lon, double lat, double elevation)
160 #ifdef SG_GEOD_NATIVE_DEGREE
161 return SGGeod(lon, lat, elevation*SG_FEET_TO_METER);
163 return SGGeod(lon*SGD_DEGREES_TO_RADIANS, lat*SGD_DEGREES_TO_RADIANS,
164 elevation*SG_FEET_TO_METER);
170 SGGeod::fromRadM(double lon, double lat, double elevation)
172 #ifdef SG_GEOD_NATIVE_DEGREE
173 return SGGeod(lon*SGD_RADIANS_TO_DEGREES, lat*SGD_RADIANS_TO_DEGREES,
176 return SGGeod(lon, lat, elevation);
182 SGGeod::fromDegM(double lon, double lat, double elevation)
184 #ifdef SG_GEOD_NATIVE_DEGREE
185 return SGGeod(lon, lat, elevation);
187 return SGGeod(lon*SGD_DEGREES_TO_RADIANS, lat*SGD_DEGREES_TO_RADIANS,
194 SGGeod::fromGeodM(const SGGeod& geod, double elevation)
196 return SGGeod(geod._lon, geod._lat, elevation);
201 SGGeod::fromGeodFt(const SGGeod& geod, double elevation)
203 return SGGeod(geod._lon, geod._lat, elevation*SG_FEET_TO_METER);
208 SGGeod::fromCart(const SGVec3<double>& cart)
211 SGGeodesy::SGCartToGeod(cart, geod);
217 SGGeod::fromGeoc(const SGGeoc& geoc)
220 SGGeodesy::SGGeocToCart(geoc, cart);
222 SGGeodesy::SGCartToGeod(cart, geod);
228 SGGeod::getLongitudeRad(void) const
230 #ifdef SG_GEOD_NATIVE_DEGREE
231 return _lon*SGD_DEGREES_TO_RADIANS;
239 SGGeod::setLongitudeRad(double lon)
241 #ifdef SG_GEOD_NATIVE_DEGREE
242 _lon = lon*SGD_RADIANS_TO_DEGREES;
250 SGGeod::getLongitudeDeg(void) const
252 #ifdef SG_GEOD_NATIVE_DEGREE
255 return _lon*SGD_RADIANS_TO_DEGREES;
261 SGGeod::setLongitudeDeg(double lon)
263 #ifdef SG_GEOD_NATIVE_DEGREE
266 _lon = lon*SGD_DEGREES_TO_RADIANS;
272 SGGeod::getLatitudeRad(void) const
274 #ifdef SG_GEOD_NATIVE_DEGREE
275 return _lat*SGD_DEGREES_TO_RADIANS;
283 SGGeod::setLatitudeRad(double lat)
285 #ifdef SG_GEOD_NATIVE_DEGREE
286 _lat = lat*SGD_RADIANS_TO_DEGREES;
294 SGGeod::getLatitudeDeg(void) const
296 #ifdef SG_GEOD_NATIVE_DEGREE
299 return _lat*SGD_RADIANS_TO_DEGREES;
305 SGGeod::setLatitudeDeg(double lat)
307 #ifdef SG_GEOD_NATIVE_DEGREE
310 _lat = lat*SGD_DEGREES_TO_RADIANS;
316 SGGeod::getElevationM(void) const
323 SGGeod::setElevationM(double elevation)
325 _elevation = elevation;
330 SGGeod::getElevationFt(void) const
332 return _elevation*SG_METER_TO_FEET;
337 SGGeod::setElevationFt(double elevation)
339 _elevation = elevation*SG_FEET_TO_METER;
344 SGGeod::operator == ( const SGGeod & other ) const
346 return _lon == other._lon &&
347 _lat == other._lat &&
348 _elevation == other._elevation;
353 SGGeod::isValid() const
355 if (SGMiscd::isNaN(_lon))
357 if (SGMiscd::isNaN(_lat))
359 #ifdef SG_GEOD_NATIVE_DEGREE
360 return (_lon >= -180.0) && (_lon <= 180.0) &&
361 (_lat >= -90.0) && (_lat <= 90.0);
363 return (_lon >= -SGD_PI) && (_lon <= SGD_PI) &&
364 (_lat >= -SGD_PI_2) && (_lat <= SGD_PI_2);
368 /// Output to an ostream
369 template<typename char_type, typename traits_type>
371 std::basic_ostream<char_type, traits_type>&
372 operator<<(std::basic_ostream<char_type, traits_type>& s, const SGGeod& g)
374 return s << "lon = " << g.getLongitudeDeg()
375 << "deg, lat = " << g.getLatitudeDeg()
376 << "deg, elev = " << g.getElevationM()