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>
27 // #define SG_GEOD_NATIVE_DEGREE
29 /// Class representing a geodetic location
32 /// Default constructor, initializes the instance to lat = lon = elev = 0
35 /// Factory from angular values in radians and elevation is 0
36 static SGGeod fromRad(double lon, double lat);
37 /// Factory from angular values in degrees and elevation is 0
38 static SGGeod fromDeg(double lon, double lat);
39 /// Factory from angular values in radians and elevation in ft
40 static SGGeod fromRadFt(double lon, double lat, double elevation);
41 /// Factory from angular values in degrees and elevation in ft
42 static SGGeod fromDegFt(double lon, double lat, double elevation);
43 /// Factory from angular values in radians and elevation in m
44 static SGGeod fromRadM(double lon, double lat, double elevation);
45 /// Factory from angular values in degrees and elevation in m
46 static SGGeod fromDegM(double lon, double lat, double elevation);
47 /// Factory from an other SGGeod and a different elevation in m
48 static SGGeod fromGeodM(const SGGeod& geod, double elevation);
49 /// Factory from an other SGGeod and a different elevation in ft
50 static SGGeod fromGeodFt(const SGGeod& geod, double elevation);
51 /// Factory to convert position from a cartesian position assumed to be
52 /// in wgs84 measured in meters
53 /// Note that this conversion is relatively expensive to compute
54 static SGGeod fromCart(const SGVec3<double>& cart);
55 /// Factory to convert position from a geocentric position
56 /// Note that this conversion is relatively expensive to compute
57 static SGGeod fromGeoc(const SGGeoc& geoc);
59 /// Return the geodetic longitude in radians
60 double getLongitudeRad(void) const;
61 /// Set the geodetic longitude from the argument given in radians
62 void setLongitudeRad(double lon);
64 /// Return the geodetic longitude in degrees
65 double getLongitudeDeg(void) const;
66 /// Set the geodetic longitude from the argument given in degrees
67 void setLongitudeDeg(double lon);
69 /// Return the geodetic latitude in radians
70 double getLatitudeRad(void) const;
71 /// Set the geodetic latitude from the argument given in radians
72 void setLatitudeRad(double lat);
74 /// Return the geodetic latitude in degrees
75 double getLatitudeDeg(void) const;
76 /// Set the geodetic latitude from the argument given in degrees
77 void setLatitudeDeg(double lat);
79 /// Return the geodetic elevation in meters
80 double getElevationM(void) const;
81 /// Set the geodetic elevation from the argument given in meters
82 void setElevationM(double elevation);
84 /// Return the geodetic elevation in feet
85 double getElevationFt(void) const;
86 /// Set the geodetic elevation from the argument given in feet
87 void setElevationFt(double elevation);
89 /// Compare two geodetic positions for equality
90 bool operator == ( const SGGeod & other ) const;
92 /// check the Geod contains sane values (finite, inside appropriate
93 /// ranges for lat/lon)
96 /// This one is private since construction is not unique if you do
97 /// not know the units of the arguments. Use the factory methods for
99 SGGeod(double lon, double lat, double elevation);
101 //// FIXME: wrong comment!
102 /// The actual data, angles in degrees, elevation in meters
103 /// The rationale for storing the values in degrees is that most code places
104 /// in flightgear/terragear use degrees as a nativ input and output value.
105 /// The places where it makes sense to use radians is when we convert
106 /// to other representations or compute rotation matrices. But both tasks
107 /// are computionally intensive anyway and that additional 'toRadian'
108 /// conversion does not hurt too much
115 SGGeod::SGGeod(void) :
116 _lon(0), _lat(0), _elevation(0)
121 SGGeod::SGGeod(double lon, double lat, double elevation) :
122 _lon(lon), _lat(lat), _elevation(elevation)
128 SGGeod::fromRad(double lon, double lat)
130 #ifdef SG_GEOD_NATIVE_DEGREE
131 return SGGeod(lon*SGD_RADIANS_TO_DEGREES, lat*SGD_RADIANS_TO_DEGREES, 0);
133 return SGGeod(lon, lat, 0);
139 SGGeod::fromDeg(double lon, double lat)
141 #ifdef SG_GEOD_NATIVE_DEGREE
142 return SGGeod(lon, lat, 0);
144 return SGGeod(lon*SGD_DEGREES_TO_RADIANS, lat*SGD_DEGREES_TO_RADIANS, 0);
150 SGGeod::fromRadFt(double lon, double lat, double elevation)
152 #ifdef SG_GEOD_NATIVE_DEGREE
153 return SGGeod(lon*SGD_RADIANS_TO_DEGREES, lat*SGD_RADIANS_TO_DEGREES,
154 elevation*SG_FEET_TO_METER);
156 return SGGeod(lon, lat, elevation*SG_FEET_TO_METER);
162 SGGeod::fromDegFt(double lon, double lat, double elevation)
164 #ifdef SG_GEOD_NATIVE_DEGREE
165 return SGGeod(lon, lat, elevation*SG_FEET_TO_METER);
167 return SGGeod(lon*SGD_DEGREES_TO_RADIANS, lat*SGD_DEGREES_TO_RADIANS,
168 elevation*SG_FEET_TO_METER);
174 SGGeod::fromRadM(double lon, double lat, double elevation)
176 #ifdef SG_GEOD_NATIVE_DEGREE
177 return SGGeod(lon*SGD_RADIANS_TO_DEGREES, lat*SGD_RADIANS_TO_DEGREES,
180 return SGGeod(lon, lat, elevation);
186 SGGeod::fromDegM(double lon, double lat, double elevation)
188 #ifdef SG_GEOD_NATIVE_DEGREE
189 return SGGeod(lon, lat, elevation);
191 return SGGeod(lon*SGD_DEGREES_TO_RADIANS, lat*SGD_DEGREES_TO_RADIANS,
198 SGGeod::fromGeodM(const SGGeod& geod, double elevation)
200 return SGGeod(geod._lon, geod._lat, elevation);
205 SGGeod::fromGeodFt(const SGGeod& geod, double elevation)
207 return SGGeod(geod._lon, geod._lat, elevation*SG_FEET_TO_METER);
212 SGGeod::fromCart(const SGVec3<double>& cart)
215 SGGeodesy::SGCartToGeod(cart, geod);
221 SGGeod::fromGeoc(const SGGeoc& geoc)
224 SGGeodesy::SGGeocToCart(geoc, cart);
226 SGGeodesy::SGCartToGeod(cart, geod);
232 SGGeod::getLongitudeRad(void) const
234 #ifdef SG_GEOD_NATIVE_DEGREE
235 return _lon*SGD_DEGREES_TO_RADIANS;
243 SGGeod::setLongitudeRad(double lon)
245 #ifdef SG_GEOD_NATIVE_DEGREE
246 _lon = lon*SGD_RADIANS_TO_DEGREES;
254 SGGeod::getLongitudeDeg(void) const
256 #ifdef SG_GEOD_NATIVE_DEGREE
259 return _lon*SGD_RADIANS_TO_DEGREES;
265 SGGeod::setLongitudeDeg(double lon)
267 #ifdef SG_GEOD_NATIVE_DEGREE
270 _lon = lon*SGD_DEGREES_TO_RADIANS;
276 SGGeod::getLatitudeRad(void) const
278 #ifdef SG_GEOD_NATIVE_DEGREE
279 return _lat*SGD_DEGREES_TO_RADIANS;
287 SGGeod::setLatitudeRad(double lat)
289 #ifdef SG_GEOD_NATIVE_DEGREE
290 _lat = lat*SGD_RADIANS_TO_DEGREES;
298 SGGeod::getLatitudeDeg(void) const
300 #ifdef SG_GEOD_NATIVE_DEGREE
303 return _lat*SGD_RADIANS_TO_DEGREES;
309 SGGeod::setLatitudeDeg(double lat)
311 #ifdef SG_GEOD_NATIVE_DEGREE
314 _lat = lat*SGD_DEGREES_TO_RADIANS;
320 SGGeod::getElevationM(void) const
327 SGGeod::setElevationM(double elevation)
329 _elevation = elevation;
334 SGGeod::getElevationFt(void) const
336 return _elevation*SG_METER_TO_FEET;
341 SGGeod::setElevationFt(double elevation)
343 _elevation = elevation*SG_FEET_TO_METER;
348 SGGeod::operator == ( const SGGeod & other ) const
350 return _lon == other._lon &&
351 _lat == other._lat &&
352 _elevation == other._elevation;
357 SGGeod::isValid() const
359 if (isnan(_lon) || isnan(_lat)) return false;
360 #ifdef SG_GEOD_NATIVE_DEGREE
361 return (_lon >= -180.0) && (_lon <= 180.0) &&
362 (_lat >= -90.0) && (_lat <= 90.0);
364 return (_lon >= -SGD_PI) && (_lon <= SGD_PI) &&
365 (_lat >= -SGD_PI_2) && (_lat <= SGD_PI_2);
369 /// Output to an ostream
370 template<typename char_type, typename traits_type>
372 std::basic_ostream<char_type, traits_type>&
373 operator<<(std::basic_ostream<char_type, traits_type>& s, const SGGeod& g)
375 return s << "lon = " << g.getLongitudeDeg()
376 << "deg, lat = " << g.getLatitudeDeg()
377 << "deg, elev = " << g.getElevationM()