void Start()
    {
        restart           = false;
        restartText.text  = "";
        gameOverText.text = "";
        pc1 = player.GetComponent <PlayerControls1>();

        SpawnWaves();
        //check not to spawn at same spot as player
        //spawn multiple times
    }
    void OnTriggerEnter2D(Collider2D other)
    {
        //if the collision is with player
        if (other.gameObject.CompareTag("Player"))
        {
            //damage player
            PlayerControls1 player = other.gameObject.GetComponent <PlayerControls1>();

            //make player's texture flash red
            player.startFlash();

            //damage player
            player.takeDamage(10);


            //destroy bullet
            Destroy(gameObject);
        }
        if (other.gameObject.CompareTag("Wall"))
        {
            Destroy(gameObject);
        }
    }