Unity C# 제네릭 오브젝트 풀링 (UnityEngine.Pool 최적화)

using System;
using UnityEngine;
using UnityEngine.Pool;

namespace LyscStudio.Patterns
{
    /// <summary>
    /// UnityEngine.Pool.ObjectPool 기반의 컴포넌트 풀 래퍼
    /// </summary>
    public class ComponentPool<T> : IDisposable where T : Component
    {
        private readonly T _prefab;
        private readonly Transform _parent;
        private readonly IObjectPool<T> _pool;

        public int ActiveCount => _pool.CountActive;
        public int InactiveCount => _pool.CountInactive;

        public ComponentPool(
            T prefab, 
            Transform parent = null, 
            int defaultCapacity = 20, 
            int maxCapacity = 200,
            bool collectionCheck = true)
        {
            _prefab = prefab;
            _parent = parent;

            _pool = new ObjectPool<T>(
                createFunc: OnCreateItem,
                actionOnGet: OnGetItem,
                actionOnRelease: OnReleaseItem,
                actionOnDestroy: OnDestroyItem,
                collectionCheck: collectionCheck, // 이미 반환된 객체의 중복 반환 검사
                defaultCapacity: defaultCapacity,
                maxSize: maxCapacity
            );
        }

        private T OnCreateItem()
        {
            T instance = UnityEngine.Object.Instantiate(_prefab, _parent);
            instance.gameObject.SetActive(false);
            return instance;
        }

        private void OnGetItem(T item)
        {
            item.gameObject.SetActive(true);
        }

        private void OnReleaseItem(T item)
        {
            if (item != null && item.gameObject.activeSelf)
            {
                item.gameObject.SetActive(false);
            }
        }

        private void OnDestroyItem(T item)
        {
            if (item != null)
            {
                UnityEngine.Object.Destroy(item.gameObject);
            }
        }

        public T Get() => _pool.Get();
        public void Release(T item) => _pool.Release(item);
        public void Clear() => _pool.Clear();

        public void Dispose()
        {
            Clear();
        }
    }
}

using System;
using UnityEngine;

public class PooledBullet : MonoBehaviour
{
    [SerializeField] private float _speed = 20f;
    [SerializeField] private float _lifeTime = 2.5f;

    private Action<PooledBullet> _returnToPool;
    private float _timer;

    public void Initialize(Action<PooledBullet> returnAction)
    {
        _returnToPool = returnAction;
        _timer = 0f;
    }

    private void Update()
    {
        transform.position += transform.forward * (_speed * Time.deltaTime);
        _timer += Time.deltaTime;

        if (_timer >= _lifeTime)
        {
            Return();
        }
    }

    private void OnTriggerEnter(Collider other)
    {
        // 충돌 로직 처리 후 풀로 반환
        Return();
    }

    private void Return()
    {
        if (_returnToPool != null)
        {
            _returnToPool(this);
            _returnToPool = null; // 중복 반환 방지
        }
    }
}