//Try to get a bullet
public GameObject GetBullet()
{
//Instead of searching a list to find an inactive object, we simply get the firstAvilable object
if (firstAvailable == null)
{
//We are out of bullets so we have to instantiate another bullet (if we can)
if (bullets.Count < MAX_POOL_SIZE)
{
GenerateBullet();
//The new bullet is last in the list so get it
MoveBulletOptimized lastBullet = bullets[bullets.Count - 1];
//Add it to the linked list by reusing the method we use for deactivated bullets, so it will now be the first bullet in the linked-list
ConfigureDeactivatedBullet(lastBullet);
}
else
{
return(null);
}
}
//Remove it from the linked-list
MoveBulletOptimized newBullet = firstAvailable;
firstAvailable = newBullet.next;
return(newBullet.gameObject);
}
//A bullet has been deactivated so we need to add it to the linked list
public void ConfigureDeactivatedBullet(MoveBulletOptimized deactivatedObj)
{
//Add it as the first in the linked list so we don't have to check if the first is null
deactivatedObj.next = firstAvailable;
firstAvailable = deactivatedObj;
}
private void Start()
{
if (bulletPrefab == null)
{
Debug.LogError("Need a reference to the bullet prefab");
}
//Instantiate new bullets and put them in a list for later use
for (int i = 0; i < INITIAL_POOL_SIZE; i++)
{
GenerateBullet();
}
//Create the linked-list
firstAvailable = bullets[0];
//Each bullet points to the next
for (int i = 0; i < bullets.Count - 1; i++)
{
bullets[i].next = bullets[i + 1];
}
//The last one terminates the linked-list
bullets[bullets.Count - 1].next = null;
}
//Generate a single new bullet and put it in the list
private void GenerateBullet()
{
MoveBulletOptimized newBullet = Instantiate(bulletPrefab, transform);
newBullet.gameObject.SetActive(false);
bullets.Add(newBullet);
//The bullet needs a reference to this object pool so we can fix the linked list when its deactivated
newBullet.objectPool = this;
}