double distanceBetweenPoints(Point a, Point b)

Approximates the distance between two points. The returned value can be up to 6% wrong in the worst case.

Source

static double distanceBetweenPoints(Point a, Point b) {
  double dx = a.x - b.x;
  double dy = a.y - b.y;
  if (dx < 0.0) dx = -dx;
  if (dy < 0.0) dy = -dy;
  if (dx > dy) {
    return dx + dy/2.0;
  }
  else {
    return dy + dx/2.0;
  }
}