// Start is called before the first frame update
    void Start()
    {
        bottomLeft = Camera.main.ScreenToWorldPoint(new Vector2(0, 0));
        topRight   = Camera.main.ScreenToWorldPoint(new Vector2(Screen.width, Screen.height));

        ball           = Instantiate(ball) as PongBall;
        playerPaddle   = Instantiate(paddle) as PongPaddle;
        computerPaddle = Instantiate(paddle) as PongPaddle;

        playerPaddle.Init(true, ball);
        computerPaddle.Init(false, ball);
    }