public void TurnWest() { direction = horizon.West; }
public void TurnSouth() { direction = horizon.South; }
public void TurnRight() { if (direction == horizon.West) direction -= 3; else direction++; }
public void TurnNorth() { direction = horizon.North; }
public void TurnLeft() { if (direction == horizon.North) direction += 3; else direction--; }
public void TurnEast() { direction = horizon.East; }