Adding Ammo Count

In today’s blog post, we’re going to add the ammo count feature so that the player will only have a limited amount of ammo. This will make our game more challenging!

First, let’s create the AmmoCountText object by duplicating the ScoreText and changing the text to “Ammo: 15”. Also, let’s position it at the top right corner below the Score text.

Next, in the Player script, let’s create two variables: _ammoCount and _isOutOfAmmo. By default, we’ll give the player 15 lasers when they start the game and set the boolean variable to false. We’ll switch it to true when the player runs out of ammo.

[SerializeField] private int _ammoCount = 15;
[SerializeField] private bool _isOutOfAmmo = false;

We’ll need an “out-of-ammo” sound for when the player hits the space key without any ammo. Let’s create a variable for that and assign it in the inspector:

[SerializeField] private AudioClip _outOfAmmoSound;

Next, let’s modify the Fire function to accommodate the ammo logic:

public void Fire()
  {
    if (_ammoCount > 0)
      {
          if (_isTripleShotActive == true)
          {
              Instantiate(_tripleShotPrefab, new Vector3(transform.position.x, transform.position.y + 1f, 0), Quaternion.identity);
          }
          else
          {
              Instantiate(_laserPrefab, new Vector3(transform.position.x, transform.position.y + 1f, 0), Quaternion.identity);
          }
          _ammoCount--;
      }
      else
      {
          _isOutOfAmmo = true;
      }
  }

The logic checks if the player is out of ammo before instantiating regular and triple shots, and reduces the ammo count for each shot fired. It also switches the _isOutOfAmmo boolean to true when there is no ammo.

Next, let’s create a method to update the ammo count text in the UIManager script:

[SerializeField] private TMP_Text _ammoCountText;

 public void UpdateAmmo(int playerAmmo)
    {
        _ammoCountText.text = "Ammo: " + playerAmmo;
    }

Let’s call the UpdateAmmo method in the Fire function as well:

if (_ammoCount > 0)
  {
      if (_isTripleShotActive == true)
      {
          Instantiate(_tripleShotPrefab, new Vector3(transform.position.x, transform.position.y + 1f, 0), Quaternion.identity);
      }
      else
      {
          Instantiate(_laserPrefab, new Vector3(transform.position.x, transform.position.y + 1f, 0), Quaternion.identity);
      }
      _ammoCount--;
      _uiManager.UpdateAmmo(_ammoCount);
  }
  else
  {
      _isOutOfAmmo = true;
  }

We also need logic to detect when the player is out of ammo and play the fire audio accordingly:

if (_isOutOfAmmo == false)
    {
        _audioSource.PlayOneShot(_laserSound);
    }
    else
    {
        _audioSource.PlayOneShot(_outOfAmmoSound);
    }

Here’s the full code:

public void Fire()
  {
      if (_ammoCount > 0)
      {
          if (_isTripleShotActive == true)
          {
              Instantiate(_tripleShotPrefab, new Vector3(transform.position.x, transform.position.y + 1f, 0), Quaternion.identity);
          }
          else
          {
              Instantiate(_laserPrefab, new Vector3(transform.position.x, transform.position.y + 1f, 0), Quaternion.identity);
          }
          _ammoCount--;
          _uiManager.UpdateAmmo(_ammoCount);
      }
      else
      {
          _isOutOfAmmo = true;
      }

      if (_isOutOfAmmo == false)
      {
          _audioSource.PlayOneShot(_laserSound);
      }
      else
      {
          _audioSource.PlayOneShot(_outOfAmmoSound);
      }
  }

And our game is working as expected!

In the next article, we’ll add a power-up that refills the ammo count allowing the player to fire again.