Object Pooling Optimization System For Unity3D

Pool.cs

// Author : github.com/farukcan
// Pooling Optimization System For Unity3D
// Requires: OdinInspector (But you can remove odin codes if you don't use it)
// Usage : Pool.GetPool("poolName");
// Usage : Pool.GetPool("poolName").GetPoolObject();
// Note: You can also use it in editor edit mode
// Spec: use expandable=true for increase amount of objects
//          when there is no enought object in pool
// Spec: Pooled Objects are defaulty not active (Check: defaultActive)

using System.Collections;
using System.Collections.Generic;
using Sirenix.OdinInspector;
using UnityEngine;

public class Pool : MonoBehaviour
{
    public static Dictionary<string, Pool> Pools = new Dictionary<string, Pool>();

    // publics
    public string poolName;
    public GameObject[] prefabs;
    public int amount = 10;
    public bool expandable = true;
    public bool defaultActive = false;

    // internals
    internal GameObject[] objects;
    internal int lastIndex = 0;

    private void Awake()
    {
        RegisterPool();
        ClearChildren();
        CreateInstances();
    }

    private void OnDestroy()
    {
        UnregisterPool();
    }

    private void CreateInstances()
    {
        amount = amount < 1 ? 0 : amount;
        objects = new GameObject[amount];
        if (amount == 0 )
        {
            Debug.Log("Pool is empty : " + poolName);
        }
        for (int i = 0; i < amount; i++)
        {
            objects[i] = Instantiate(prefabs[i%prefabs.Length], transform);
            objects[i].SetActive(defaultActive);
        }
    }

    private void RegisterPool()
    {
        if (Pools.ContainsKey(poolName))
        {
            Debug.Log("Overriding pool : " + poolName);
        }
        Pools[poolName] = this;
    }

    private void UnregisterPool()
    {
        Pools.Remove(poolName);
    }

    [Button("Clear Children")]
    public void ClearChildren(){
        while(transform.childCount > 0){
            DestroyImmediate(transform.GetChild(0).gameObject);
        }
    }

    public GameObject GetPooledObject()
    {
        #if UNITY_EDITOR
        if(UnityEditor.EditorApplication.isPlaying == false){
            return UnityEditor.PrefabUtility.InstantiatePrefab(
                prefabs[Mathf.FloorToInt(amount*Random.value)%prefabs.Length],
                transform
            ) as GameObject;
        }
        #endif
        int i = lastIndex;
        if(expandable && objects[i].activeSelf){
            int j = amount;
            do {
                j--;
                lastIndex = (lastIndex + 1) % amount;
            }while(objects[lastIndex].activeSelf && j>0);
            if(j==0){
                lastIndex = amount;
                List<GameObject> list = new List<GameObject>();
                list.AddRange(objects);
                GameObject additional = Instantiate(prefabs[amount%prefabs.Length], transform);
                additional.SetActive(false);
                list.Add(additional);
                objects = list.ToArray();
                amount++;
            }
            i=lastIndex;
        }else{
            lastIndex = (i + 1) % amount;
        }
        return objects[i];
    }

    public static Pool GetPool(string name)
    {
        if(Pools.ContainsKey(name)){
            return Pools[name];
        }
        #if UNITY_EDITOR
        Pool[] _pools = GameObject.FindObjectsOfType<Pool>();
        foreach (Pool pool in _pools)
        {
            if (pool.poolName == name)
            {
                return pool;
            }
        }
        Debug.LogError("Pool not found : " + name);
        #endif
        return null;
    }
}