performance-aware-programming/haversine_02/src/haversine.cpp

31 lines
656 B
C++

#include "haversine.h"
#include "aliases.h"
#include "point_types.h"
#include <math.h>
#define PI 3.14159265358979323845
#define SQUARE(X) ((X) * (X))
f64 radians(f64 degrees);
f64 haversine_of_degrees(const PointPair &pair, f64 radius) {
f64 x0 = pair.p1.x;
f64 y0 = pair.p1.y;
f64 x1 = pair.p2.x;
f64 y1 = pair.p2.y;
f64 dy = radians(y1 - y0);
f64 dx = radians(x1 - x0);
y0 = radians(y0);
y1 = radians(y1);
f64 root_term =
SQUARE(sin(dy / 2.0)) + cos(y0) * cos(y1) * SQUARE(sin(dx / 2.0));
f64 result = 2.0 * radius * asin(sqrt(root_term));
return result;
}
f64 radians(f64 degrees) { return (degrees * PI) / 180.0; }