-// polar.hxx -- routines to deal with polar math and transformations
-//
+/**
+ * \file polar3d.hxx
+ * Routines to deal with polar math and transformations.
+ */
+
// Written by Curtis Olson, started June 1997.
//
-// Copyright (C) 1997 Curtis L. Olson - curt@infoplane.com
+// Copyright (C) 1997 Curtis L. Olson - http://www.flightgear.org/~curt
//
-// This program is free software; you can redistribute it and/or
-// modify it under the terms of the GNU General Public License as
-// published by the Free Software Foundation; either version 2 of the
-// License, or (at your option) any later version.
+// This library is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Library General Public
+// License as published by the Free Software Foundation; either
+// version 2 of the License, or (at your option) any later version.
//
-// This program is distributed in the hope that it will be useful, but
-// WITHOUT ANY WARRANTY; without even the implied warranty of
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-// General Public License for more details.
+// Library General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
-// Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
//
// $Id$
-#ifndef _POLAR_HXX
-#define _POLAR_HXX
+#ifndef _POLAR3D_HXX
+#define _POLAR3D_HXX
-#ifndef __cplusplus
+#ifndef __cplusplus
# error This library requires C++
-#endif
+#endif
#include <simgear/constants.h>
-#include <simgear/point3d.hxx>
-
-
-// Find the Altitude above the Ellipsoid (WGS84) given the Earth
-// Centered Cartesian coordinate vector Distances are specified in
-// meters.
-double fgGeodAltFromCart(const Point3D& cp);
-
-
-// Convert a polar coordinate to a cartesian coordinate. Lon and Lat
-// must be specified in radians. The FG convention is for distances
-// to be specified in meters
-inline Point3D fgPolarToCart3d(const Point3D& p) {
- double tmp = cos( p.lat() ) * p.radius();
-
- return Point3D( cos( p.lon() ) * tmp,
- sin( p.lon() ) * tmp,
- sin( p.lat() ) * p.radius() );
+#include <simgear/math/point3d.hxx>
+
+#include "SGMath.hxx"
+
+/**
+ * Find the Altitude above the Ellipsoid (WGS84) given the Earth
+ * Centered Cartesian coordinate vector Distances are specified in
+ * meters.
+ * @param cp point specified in cartesian coordinates
+ * @return altitude above the (wgs84) earth in meters
+ */
+inline double sgGeodAltFromCart(const Point3D& p)
+{
+ SGGeod geod;
+ SGGeodesy::SGCartToGeod(SGVec3<double>(p.x(), p.y(), p.z()), geod);
+ return geod.getElevationM();
}
-// Convert a cartesian coordinate to polar coordinates (lon/lat
-// specified in radians. Distances are specified in meters.
-inline Point3D fgCartToPolar3d(const Point3D& cp) {
- return Point3D( atan2( cp.y(), cp.x() ),
- FG_PI_2 -
- atan2( sqrt(cp.x()*cp.x() + cp.y()*cp.y()), cp.z() ),
- sqrt(cp.x()*cp.x() + cp.y()*cp.y() + cp.z()*cp.z()) );
+/**
+ * Convert a polar coordinate to a cartesian coordinate. Lon and Lat
+ * must be specified in radians. The SG convention is for distances
+ * to be specified in meters
+ * @param p point specified in polar coordinates
+ * @return the same point in cartesian coordinates
+ */
+inline Point3D sgPolarToCart3d(const Point3D& p)
+{
+ SGVec3<double> cart;
+ SGGeodesy::SGGeocToCart(SGGeoc::fromRadM(p.lon(), p.lat(), p.radius()), cart);
+ return Point3D::fromSGVec3(cart);
}
-// calc new lon/lat given starting lon/lat, and offset radial, and
-// distance. NOTE: starting point is specifed in radians, distance is
-// specified in meters (and converted internally to radians)
-// ... assumes a spherical world
-inline Point3D calc_lon_lat( const Point3D& orig, double course, double dist ) {
- Point3D result;
-
- // lat=asin(sin(lat1)*cos(d)+cos(lat1)*sin(d)*cos(tc))
- // IF (cos(lat)=0)
- // lon=lon1 // endpoint a pole
- // ELSE
- // lon=mod(lon1-asin(sin(tc)*sin(d)/cos(lat))+pi,2*pi)-pi
- // ENDIF
-
- // printf("calc_lon_lat() offset.theta = %.2f offset.dist = %.2f\n",
- // offset.theta, offset.dist);
-
- dist *= METER_TO_NM * NM_TO_RAD;
-
- result.sety( asin( sin(orig.y()) * cos(dist) +
- cos(orig.y()) * sin(dist) * cos(course) ) );
-
- if ( cos(result.y()) < FG_EPSILON ) {
- result.setx( orig.x() ); // endpoint a pole
- } else {
- result.setx(
- fmod(orig.x() - asin( sin(course) * sin(dist) /
- cos(result.y()) ) + FG_PI, FG_2PI) - FG_PI );
- }
-
- return result;
+/**
+ * Convert a cartesian coordinate to polar coordinates (lon/lat
+ * specified in radians. Distances are specified in meters.
+ * @param cp point specified in cartesian coordinates
+ * @return the same point in polar coordinates
+ */
+inline Point3D sgCartToPolar3d(const Point3D& p)
+{
+ SGGeoc geoc;
+ SGGeodesy::SGCartToGeoc(SGVec3<double>(p.x(), p.y(), p.z()), geoc);
+ return Point3D::fromSGGeoc(geoc);
}
-#endif // _POLAR_HXX
-
+/**
+ * Calculate new lon/lat given starting lon/lat, and offset radial, and
+ * distance. NOTE: starting point is specifed in radians, distance is
+ * specified in meters (and converted internally to radians)
+ * ... assumes a spherical world.
+ * @param orig specified in polar coordinates
+ * @param course offset radial
+ * @param dist offset distance
+ * @return destination point in polar coordinates
+ */
+Point3D calc_gc_lon_lat( const Point3D& orig, double course, double dist );
+
+
+/**
+ * Calculate course/dist given two spherical points.
+ * @param start starting point
+ * @param dest ending point
+ * @param course resulting course
+ * @param dist resulting distance
+ */
+void calc_gc_course_dist( const Point3D& start, const Point3D& dest,
+ double *course, double *dist );
+
+#if 0
+/**
+ * Calculate course/dist given two spherical points.
+ * @param start starting point
+ * @param dest ending point
+ * @param course resulting course
+ * @param dist resulting distance
+ */
+void calc_gc_course_dist( const Point3D& start, const Point3D& dest,
+ double *course, double *dist );
+#endif // 0
+
+#endif // _POLAR3D_HXX
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