geo.cpp

#define _USE_MATH_DEFINES
#include <cmath>
#include "geo.hpp"
#include <sstream>
#include <stdexcept>

string geocoord2string(double angle) {
	if ( (angle > 180) || (angle < -180) )
		throw invalid_argument("Invalid argument : angle must be beetween -180° and 180°");
	int deg = int(floor(angle));
	double rest = angle - deg;
	int minute = int(floor( rest * 60));
	rest = rest * 60 - minute;
	int second = int(floor( rest * 60));
	ostringstream result;
	result << deg << "° " << minute << "' " << second <<"''";
	return result.str();
}

double deg2rad(double deg) {
  return (deg * M_PI / 180);
}

GeoPoint::GeoPoint(double lat, double lng) : lat(lat), lng(lng)
{}

double GeoPoint::distance(const GeoPoint &other) {

 
    double nDLat = deg2rad(other.lat - this->lat);
    double nDLon = deg2rad(other.lng - this->lng);
 
    double thisLatRad =  deg2rad(this->lat);
    double otherLatRad =  deg2rad(other.lat);
 
    double nA = pow ( sin(nDLat/2), 2 ) + cos(thisLatRad) * cos(otherLatRad) * pow ( sin(nDLon/2), 2 );
 
    double nC = 2 * atan2( sqrt(nA), sqrt( 1 - nA ));
    double nD = EARTH_RADIUS * nC;
 
    return nD; // Return our calculated distance
}