I know there are plenty of Pool Mangers out there, but another one can’t hurt. I simplified this one down to work with simple Spawn and Destroy commands. Hopefully it makes life easier for some one out there. I hope that we can all improve and maintain this simple, but incredibly useful piece of code.
The original script is based off of the Von Lehe Creative Blog. It’s changed to C# and doesn’t require you to bind it to a prefab like the original. I recorded some performance metrics if you’re interested in looking at those things also.
Unity 4.0 users will have to change the deactivation function. I believe it was updated.
using UnityEngine;
using System;
using System.Collections;
using System.Collections.Generic;
public class GameObjectPoolManager {
private static List _PoolObjectList = new List();
public static PoolObjectModel AddNewPoolObject(GameObject prefab, uint initialCapacity)
{
PoolObjectModel newPoolObject = new PoolObjectModel();
newPoolObject.Prefab = prefab;
newPoolObject.PrefabName = prefab.name + “(Clone)”;
newPoolObject.All = (initialCapacity > 0) ? new ArrayList((int) initialCapacity) : new ArrayList();
newPoolObject.Available = (initialCapacity > 0) ? new Stack((int) initialCapacity) : new Stack();
_PoolObjectList.Add(newPoolObject);
return newPoolObject;
}
public static int numActive (GameObject prefab)
{
PoolObjectModel poolObject = GetPoolObjectByPrefab(prefab);
if(poolObject == null)
return 0;
else
return poolObject.All.Count – poolObject.Available.Count;
}
public static int numAvailable (GameObject prefab)
{
PoolObjectModel poolObject = GetPoolObjectByPrefab(prefab);
if(poolObject == null)
return 0;
else
return poolObject.Available.Count;
}
public static GameObject Spawn(GameObject prefab, Vector3 position, Quaternion rotation)
{
GameObject result;
PoolObjectModel currentPoolObject = new PoolObjectModel();
if(DoesPoolObjectExist(prefab))
{
currentPoolObject = GetPoolObjectByPrefab(prefab);
//Debug.Log(“Old Pool ” + currentPoolObject.PrefabName );
}
else
{
currentPoolObject = AddNewPoolObject(prefab, 3);
//Debug.Log(“New Pool ” + currentPoolObject.PrefabName);
}
if (currentPoolObject.Available.Count == 0)
{
// create an object and initialize it.
//Debug.Log(“Instantiate new object” + currentPoolObject.PrefabName);
result = GameObject.Instantiate(prefab, position, rotation) as GameObject;
currentPoolObject.All.Add(result);
}
else
{
//Debug.Log(“Reuse Old object” + currentPoolObject.PrefabName);
result = currentPoolObject.Available.Pop() as GameObject;
// get the result’s transform and reuse for efficiency.
// calling gameObject.transform is expensive.
if(result == null)
{
result = GameObject.Instantiate(prefab, position, rotation) as GameObject;
}
Transform resultTrans = result.transform;
resultTrans.position = position;
resultTrans.rotation = rotation;
SetActive(result, true);
//Debug.Log(“Is Active: ” + result.active);
}
return result;
}
public static bool Destroy(GameObject target)
{
PoolObjectModel currentPoolObject = GetPoolObjectByPrefab(target);
if(DoesPoolObjectExist(target))
{
if (!currentPoolObject.Available.Contains(target))
{
currentPoolObject.Available.Push(target);
SetActive(target, false);
//Debug.Log(“Is Active: ” + target.active);
return true;
}
}
else
{
Destroy(target);
return true;
}
return false;
}
public static void DestroyAll()
{
foreach(PoolObjectModel poolObject in _PoolObjectList)
{
for (int i=0; i<poolObject.All.Count; i++)
{
GameObject target = poolObject.All[i] as GameObject;
if (target.active)
Destroy(target);
}
}
}
// Unspawns all the game objects and clears the pool.
public static void Clear() {
DestroyAll();
foreach(PoolObjectModel poolObject in _PoolObjectList)
{
poolObject.Available.Clear();
poolObject.All.Clear();
}
}
public static bool DoesPoolObjectExist(GameObject prefabObject)
{
bool prefabExists = false;
string prefabName;
if(prefabObject.name.Contains(“(Clone)”))
prefabName = prefabObject.name;
else
prefabName = prefabObject.name + “(Clone)”;
foreach(PoolObjectModel poolObject in _PoolObjectList)
{
if ( poolObject.PrefabName == prefabName)
prefabExists = true;
}
return prefabExists;
}
protected static void SetActive(GameObject target, bool active)
{
RecursiveDeepActivation(target.transform, active);
}
protected static PoolObjectModel GetPoolObjectByPrefab(GameObject prefabObject)
{
string prefabName;
if(prefabObject.name.Contains(“(Clone)”))
prefabName = prefabObject.name;
else
prefabName = prefabObject.name + “(Clone)”;
PoolObjectModel poolObjectToReturn = new PoolObjectModel();
foreach(PoolObjectModel poolObject in _PoolObjectList)
{
if ( poolObject.PrefabName == prefabName)
poolObjectToReturn = poolObject;
}
return poolObjectToReturn;
}
protected static void RecursiveDeepActivation(Transform gameObjectTransform, bool activate)
{
foreach (Transform t in gameObjectTransform)
{
RecursiveDeepActivation (t, activate);
}
gameObjectTransform.gameObject.active = activate;
}
}