/*
 *
 *  geo-dist
 *
 *  Copyright (C) 2006 Nils Faerber <nils.faerber@kernelconcepts.de>
 *
 *
 *  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 program 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.
 *
 *  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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */

#ifndef _GEO_DIST_H
#define _GEO_DIST_H

#ifdef __cplusplus
extern "C"
{
#endif

/*
 * Calculate distances on Earth surface given geographic locations
 */

typedef enum {
	WGS84,
	NAD27,
	International,
	Krasovsky,
	Bessel,
	WGS72,
	WGS66,
	FAIsphere
} EllipsoidType;

/* nautical in kilometer */
#define NAUTICAL_MILE 1.852

/*
 * glat1, glat2: geodetic latitude in radians, N positive
 * glon1, glon2: geodetic longitude in radians E positive
 * Coordinates in radians means
 * 50°50.32N ^= 50 degree, 50 minutes and 32 seconds
 *           ^= 50 + (50 / 60) + (32 / 3600)
 *           ^= 50.84222
 *
 * returns: distance in nm (nautical miles), factor of 1.852 gives km
 */
double dist_ell(double, double, double, double, EllipsoidType);

#ifdef __cplusplus
}
#endif

#endif /* _GEO_DIST_H */