module Collision
where

boxArea (x, y) r = ((x - r, x + r), (y - r, y + r))

collides1d (a, b) (c, d) =
  (a < c && c < b) || (a < d && d < b) ||
  (c < a && a < d) || (c < b && b < d)

collides2d (x1, y1) (x2, y2) =
  collides1d x1 x2 && collides1d y1 y2