message: sanity check to fix possible FPE
diff: @@ -495,6 +495,9 @@ std::pair<int,int> MobManager::lerp(int x1, int y1, int x2, int y2, int speed) {
  int distance = hypot(x1 - x2, y1 - y2);
  if (distance > speed) {
  + if (speed == 0)
  + speed = 1;
  +
  int lerps = distance / speed;
  // interpolate only the first point
  