Allow geocentric distance computations to return radians.

[simgear.git] / simgear / math / sg_geodesy.hxx

diff --git a/simgear/math/sg_geodesy.hxx b/simgear/math/sg_geodesy.hxx
index c2f9b291c29dde6a07685370d2102ee1a41305f4..f19e4358460e55965399180dc97a403ed5513835 100644 (file)
--- a/simgear/math/sg_geodesy.hxx
+++ b/simgear/math/sg_geodesy.hxx
@@ -4,38 +4,8 @@
 #include <simgear/math/point3d.hxx>
 #include "SGMath.hxx"
 
-// Returns the insersection of the line joining the center of the
-// earth and the specified cylindrical point with the surface of the
-// WGS84 ellipsoid.  Works by finding a normalization constant (in
-// squashed space) that places the squashed point on the surface of
-// the sphere.
-inline double seaLevelRadius(double r, double z)
-{
-    double sr = r * SGGeodesy::SQUASH;
-    double zz = z*z;
-    return SGGeodesy::POLRAD*sqrt((r*r + zz)/(sr*sr + zz));
-}
-
-/** 
- * Convert from geocentric coordinates to geodetic coordinates
- * @param lat_geoc (in) Geocentric latitude, radians, + = North
- * @param radius (in) C.G. radius to earth center (meters)
- * @param lat_geod (out) Geodetic latitude, radians, + = North
- * @param alt (out) C.G. altitude above mean sea level (meters)
- * @param sea_level_r (out) radius from earth center to sea level at
- *        local vertical (surface normal) of C.G. (meters)
- */
-inline void sgGeocToGeod(double lat_geoc, double radius,
-                         double *lat_geod, double *alt, double *sea_level_r)
-{
-  SGVec3<double> cart;
-  SGGeodesy::SGGeocToCart(SGGeoc::fromRadM(0, lat_geoc, radius), cart);
-  SGGeod geod;
-  SGGeodesy::SGCartToGeod(cart, geod);
-  *lat_geod = geod.getLatitudeRad();
-  *alt = geod.getElevationM();
-  *sea_level_r = SGGeodesy::SGGeodToSeaLevelRadius(geod);
-}
+// Compatibility header.
+// Please use the SGGeodesy and SGMath functions directly.
 
 /**
  * Convert from geodetic coordinates to geocentric coordinates.
@@ -56,11 +26,12 @@ inline void sgGeodToGeoc(double lat_geod, double alt,
                          double *sl_radius, double *lat_geoc)
 {
   SGVec3<double> cart;
-  SGGeodesy::SGGeodToCart(SGGeod::fromRadM(0, lat_geod, alt), cart);
+  SGGeod geod = SGGeod::fromRadM(0, lat_geod, alt);
+  SGGeodesy::SGGeodToCart(geod, cart);
   SGGeoc geoc;
   SGGeodesy::SGCartToGeoc(cart, geoc);
   *lat_geoc = geoc.getLatitudeRad();
-  *sl_radius = seaLevelRadius(cart(0), cart(2));
+  *sl_radius = SGGeodesy::SGGeodToSeaLevelRadius(geod);
 }
 
 
@@ -130,7 +101,7 @@ inline Point3D sgGeodToCart(const Point3D& geod)
 /**
  * Given a starting position and an offset radial and distance,
  * calculate an ending positon on a wgs84 ellipsoid.
- * @param alt (in) meters
+ * @param alt (in) meters (unused)
  * @param lat1 (in) degrees
  * @param lon1 (in) degrees
  * @param az1 (in) degrees
@@ -139,16 +110,42 @@ inline Point3D sgGeodToCart(const Point3D& geod)
  * @param lon2 (out) degrees
  * @param az2 (out) return course in degrees
  */
-int geo_direct_wgs_84 ( double alt, double lat1,
+inline int geo_direct_wgs_84 ( double lat1, double lon1, double az1, 
+                               double s, double *lat2, double *lon2,
+                               double *az2 )
+{
+  SGGeod p2;
+  if (!SGGeodesy::direct(SGGeod::fromDeg(lon1, lat1), az1, s, p2, *az2))
+    return 1;
+  *lat2 = p2.getLatitudeDeg();
+  *lon2 = p2.getLongitudeDeg();
+  return 0;
+}
+inline int geo_direct_wgs_84 ( double alt, double lat1,
                         double lon1, double az1, 
                        double s, double *lat2, double *lon2,
-                        double *az2 );
+                        double *az2 )
+{ return geo_direct_wgs_84(lat1, lon1, az1, s, lat2, lon2, az2); }
 
+/**
+ * Given a starting position and an offset radial and distance,
+ * calculate an ending positon on a wgs84 ellipsoid.
+ * @param p1 (in) geodetic position
+ * @param az1 (in) degrees
+ * @param s (in) distance in meters
+ * @param p2 (out) geodetic position
+ * @param az2 (out) return course in degrees
+ */
+inline int geo_direct_wgs_84(const SGGeod& p1, double az1,
+                             double s, SGGeod& p2, double *az2 )
+{
+  return !SGGeodesy::direct(p1, az1, s, p2, *az2);
+}
 
 /**
  * Given an altitude and two sets of (lat, lon) calculate great circle
  * distance between them as well as the starting and ending azimuths.
- * @param alt (in) meters
+ * @param alt (in) meters (unused)
  * @param lat1 (in) degrees
  * @param lon1 (in) degrees
  * @param lat2 (in) degrees
@@ -157,9 +154,33 @@ int geo_direct_wgs_84 ( double alt, double lat1,
  * @param az2 (out) end heading degrees
  * @param s (out) distance meters
  */
-int geo_inverse_wgs_84( double alt, double lat1,
-                        double lon1, double lat2,
-                       double lon2, double *az1, double *az2,
-                        double *s );
+inline int geo_inverse_wgs_84( double lat1, double lon1, double lat2,
+                               double lon2, double *az1, double *az2,
+                               double *s )
+{
+  return !SGGeodesy::inverse(SGGeod::fromDeg(lon1, lat1),
+                             SGGeod::fromDeg(lon2, lat2), *az1, *az2, *s);
+}
+inline int geo_inverse_wgs_84( double alt, double lat1,
+                               double lon1, double lat2,
+                               double lon2, double *az1, double *az2,
+                               double *s )
+{ return geo_inverse_wgs_84(lat1, lon1, lat2, lon2, az1, az2, s); }
+
+
+/**
+ * Given an altitude and two sets of (lat, lon) calculate great circle
+ * distance between them as well as the starting and ending azimuths.
+ * @param p1 (in) first position
+ * @param p2 (in) fsecond position
+ * @param az1 (out) start heading degrees
+ * @param az2 (out) end heading degrees
+ * @param s (out) distance meters
+ */
+inline int geo_inverse_wgs_84(const SGGeod& p1, const SGGeod& p2,
+                              double *az1, double *az2, double *s )
+{
+  return !SGGeodesy::inverse(p1, p2, *az1, *az2, *s);
+}
 
 #endif // _SG_GEODESY_HXX