private void OnTriggerEnter2D(Collider2D collision)
 {
     if (collision.gameObject.CompareTag("PowerUp"))
     {
         if (currentPowerUp == PowerUpScript.PowerUpType.None)
         {
             SoundManager.instance.PlayerSound(SoundManager.instance.Aura);
             currentPowerUp = collision.gameObject.GetComponent <PowerUpScript>().myType;
             powerUpUIManager.OpenPanel(collision.GetComponent <SpriteRenderer>().sprite);
             Destroy(collision.gameObject);
         }
     }
 }
    private void Update()
    {
        timer += Time.deltaTime;

        if ((Input.GetKey(KeyCode.Space) || Input.GetButton("ControllerShoot")))
        {
            if (cannonInUse)
            {
                if (timer - timerOnLastShoot > canonCooldownTime)
                {
                    Instantiate(cannonBulletPrefab, transform.position, Quaternion.identity);
                    timerOnLastShoot = timer;
                }

                if (timer - cannonStartTime > cannonPowerTime)
                {
                    cannonInUse = false;
                    cannon.gameObject.SetActive(false);
                    SpawnTrash();
                }
            }
            else
            {
                if (timer - timerOnLastShoot > cooldownTime)
                {
                    Instantiate(bulletPrefab, transform.position, Quaternion.identity);
                    timerOnLastShoot = timer;
                }
            }
        }

        if (currentPowerUp != PowerUpScript.PowerUpType.None && (Input.GetKeyDown(KeyCode.E) || Input.GetButton("ControllerPowerUp")))
        {
            // TODO: Use Power up.
            switch (currentPowerUp)
            {
            case PowerUpScript.PowerUpType.Cannon:
                cannonInUse     = true;
                cannonStartTime = timer;
                SoundManager.instance.PlayerSound(SoundManager.instance.Cannon1);
                cannon.gameObject.SetActive(true);
                break;

            case PowerUpScript.PowerUpType.Shield:
                SoundManager.instance.PlayerSound(SoundManager.instance.Construction);
                ToogleShield(true);
                SpawnTrash();
                break;

            case PowerUpScript.PowerUpType.Explosion:
                Instantiate(explosion, transform.position, Quaternion.identity);
                CameraScript.camera.SetCameraShake(0.6f, 1.5f);
                SoundManager.instance.PlayerSound(SoundManager.instance.Explosion1);
                SpawnTrash();
                break;

            case PowerUpScript.PowerUpType.Electro:
                GameObject radioEffect = Instantiate(radioEmp, transform.position, Quaternion.identity);
                Destroy(radioEffect, 1);
                SoundManager.instance.PlayerSound(SoundManager.instance.Radio);
                SpawnTrash();
                break;
            }
            currentPowerUp = PowerUpScript.PowerUpType.None;

            powerUpUIManager.ClosePanel();
        }
    }