+ // we're going to divide by the difference of these pairs soon;
+ // if they're the same, we'll be dividing by zero, and we don't
+ // want to do that!
+ // \todo what should we do in this case?
+ if (min_point[0] == max_point[0]) max_point[0] += 0.001;
+ if (min_point[1] == max_point[1]) max_point[1] += 0.001;