Added object pooling for enemy game objects.

Overview

The EnemyPool class is a singleton-based implementation of an object pool for managing reusable enemy objects in a game. It dynamically creates and manages object pools for different enemy types, optimizing resource usage and reducing overhead from frequent instantiation and destruction.

1. EnemyPool Class

Purpose

To manage and provide a pool of reusable enemy objects, ensuring efficient resource utilization.

Singleton Pattern

public static EnemyPool instance; 

Ensures that only one instance of the EnemyPool exists in the game.

Fields

[SerializeField] private Transform pool; 
private Dictionary<EnemyType, ObjectPool<GameObject>> enemyPool = new Dictionary<EnemyType, ObjectPool<GameObject>>(); 

• pool: A Transform that serves as the parent container for inactive enemy objects.

• enemyPool: A dictionary mapping EnemyType to their respective object pools.

2. Methods

void Awake()

Ensures the singleton instance is initialized.

private void Awake() 
{     
   instance = this; 
} 

GameObject GetEnemyObj(EnemyType enemyType, GameObject enemyPrefabRef)

Retrieves an enemy object from the pool or creates a new pool if none exists for the specified type.

Parameters:

• enemyType: The type of enemy to retrieve.

• enemyPrefabRef: The prefab to use for instantiating a new enemy if required.

Returns:

• A GameObject representing the requested enemy.

public GameObject GetEnemyObj(EnemyType enemyType, GameObject enemyPrefabRef) 

• If the pool for the specified type does not exist, a new pool is created.

• Returns an enemy object from the relevant pool.

void ReturnEnemyObj(EnemyType enemyType, GameObject enemyPrefabRef)

Returns an enemy object to its pool.

Parameters:

• enemyType: The type of enemy to return.

• enemyPrefabRef: The enemy object being returned to the pool.

public void ReturnEnemyObj(EnemyType enemyType, GameObject enemyPrefabRef) 

• If the pool exists for the specified type, the object is released back into the pool.

• If no pool exists, the object is destroyed as a fallback.

ObjectPool<GameObject> CreateNewPool(GameObject enemyPrefabRef)

Creates a new object pool for the specified enemy prefab.

Parameters:

• enemyPrefabRef: The prefab for the enemy type to pool.

Returns:

• A new ObjectPool<GameObject> instance.

public ObjectPool<GameObject> CreateNewPool(GameObject enemyPrefabRef) 

• Specifies the creation, release, and destruction behaviors for the pool.

Pool Behaviors

void OnGet(GameObject obj)

Defines the behavior when an object is retrieved from the pool.

private void OnGet(GameObject obj) 
{     
  obj.SetActive(true); 
} 

• Placeholder for activating the object.

void OnRelease(GameObject obj)

Defines the behavior when an object is returned to the pool.

private void OnRelease(GameObject obj) 
{     
    obj.transform.SetParent(pool);     
    obj.SetActive(false); 
} 

• Deactivates the object and assigns it to the designated pool container.

void OnDestroyPooledObject(GameObject obj)

Defines the behavior for destroying a pooled object.

private void OnDestroyPooledObject(GameObject obj) 
{     
    Destroy(obj);
} 

• Permanently destroys the object if it is no longer needed.

Summary

• Dynamic Pool Creation: Automatically creates pools for new enemy types.

• Reusable Objects: Reduces instantiation overhead by reusing enemy objects.

• Resource Management: Ensures efficient memory and performance management.
  
  Check out this for code implementation: EnemyPool