package calc

import "math"

// shortest distance between points on torus map
func ShortDistance(w, h uint32, x1, y1, x2, y2 float64) float64 {
	return math.Hypot(Deltas(w, h, x1, y1, x2, y2))
}

func Deltas(w, h uint32, x1, y1, x2, y2 float64) (float64, float64) {
	dx := math.Abs(x2 - x1)
	dy := math.Abs(y2 - y1)
	if dx > float64(w/2) {
		dx = float64(h) - dx
	}
	if dy > float64(h/2) {
		dy = float64(h) - dy
	}
	return dx, dy
}