#include "../pch/pch.h"
#include "CLewaimaiDistance.h"

#define PI 3.141592657
#define EARTH_RADIUS  6378137

CLewaimaiDistance::CLewaimaiDistance()
{
}


CLewaimaiDistance::~CLewaimaiDistance()
{
}

double CLewaimaiDistance::getDistance(CLewaimaiPos pos1, CLewaimaiPos pos2)
{
	double Rad = PI / 180.0;

	double radlat1 = pos1.lat * Rad;
	double radlat2 = pos2.lat * Rad;

	double a = radlat1 - radlat2;
	double b = (pos1.lng - pos2.lng) * Rad;

	double s = 2 * asin(sqrt(pow(sin(a / 2), 2) + cos(radlat1)*cos(radlat2)*pow(sin(b / 2), 2)));
	s = s * EARTH_RADIUS;
	s = round(s * 10000) / 10000;

	return s;
}