// Unity Singleton Pattern

// Use for managers that need exactly one instance (AudioManager, GameManager).

// Survives scene loads. Self-creates if missing.

// Uses FindFirstObjectByType (not the deprecated FindObjectOfType).

using UnityEngine;

namespace MyGame

{

public class Singleton<T> : MonoBehaviour where T : MonoBehaviour

{

private static T _instance;

private static readonly object _lock = new();

private static bool _applicationIsQuitting;

public static T Instance

{

get

{

if (_applicationIsQuitting)

return null;

lock (_lock)

{

if (_instance == null)

{

_instance = FindFirstObjectByType<T>();

if (_instance == null)

{

var singletonObject = new GameObject(typeof(T).Name);

_instance = singletonObject.AddComponent<T>();

DontDestroyOnLoad(singletonObject);

}

}

return _instance;

}

}

}

protected virtual void Awake()

{

if (_instance == null)

{

_instance = this as T;

DontDestroyOnLoad(gameObject);

}

else if (_instance != this)

{

Destroy(gameObject);

}

}

private void OnApplicationQuit()

{

_applicationIsQuitting = true;

}

}

}