Update

Author: IntoTheDev

Global Pools.meta

@@ -0,0 +1,19 @@
+%YAML 1.1
+%TAG !u! tag:unity3d.com,2011:
+--- !u!114 &11400000
+MonoBehaviour:
+  m_ObjectHideFlags: 0
+  m_CorrespondingSourceObject: {fileID: 0}
+  m_PrefabInstance: {fileID: 0}
+  m_PrefabAsset: {fileID: 0}
+  m_GameObject: {fileID: 0}
+  m_Enabled: 1
+  m_EditorHideFlags: 0
+  m_Script: {fileID: 11500000, guid: b1b86f0f7a2abb3438596be3b0b6018e, type: 3}
+  m_Name: TestPool
+  m_EditorClassIdentifier: 
+  _pool:
+    _prefab: {fileID: -5867640059013084840, guid: 58be6d132003ec14087e25cfa3ceb8fb,
+      type: 3}
+    _startCount: 5
+    _holder: {fileID: 0}

Global Pools/TestPool.asset

@@ -0,0 +1,25 @@
+using Sirenix.OdinInspector;
+using System;
+using ToolBox.Reactors;
+using UnityEngine;
+
+namespace ToolBox.Pools
+{
+    [CreateAssetMenu(menuName = "ToolBox/Global Pool"), Required, AssetSelector]
+    public sealed class GlobalPool : ScriptableObject, ISetupable
+    {
+        [SerializeField, HideLabel] private Pool _pool = null;
+        [ShowInInspector, ReadOnly, NonSerialized] private bool _isFilled = false;
+
+        public Pool Pool => _pool;
+
+        public void Setup()
+        {
+            if (!_isFilled)
+            {
+                _pool.Fill();
+                _isFilled = true;
+            }
+        }
+    }
+}

Global Pools/TestPool.asset.meta

@@ -0,0 +1,7 @@
+namespace ToolBox.Pools
+{
+	public interface IPoolable
+	{
+		void Reset();
+	}
+}

GlobalPool.cs

@@ -1,11 +1,11 @@
 using Sirenix.OdinInspector;
+using System;
 using System.Collections.Generic;
-using ToolBox.Reactors;
 using UnityEngine;
 
 namespace ToolBox.Pools
 {
-	[System.Serializable]
+	[Serializable]
 	public class Pool
 	{
 		[SerializeField, AssetList, AssetsOnly] private Poolable _prefab = null;
@@ -27,12 +27,9 @@ public void Fill()
 			_entities = new Queue<Poolable>(_startCount);
 			_currentCount = _startCount;
 
-			Poolable original = Object.Instantiate(_prefab, _holder);
-			AddToPool(original);
-
-			for (int i = 0; i < _startCount - 1; i++)
+			for (int i = 0; i < _startCount; i++)
 			{
-				Poolable entity = Object.Instantiate(original, _holder);
+				Poolable entity = UnityEngine.Object.Instantiate(_prefab, _holder);
 				AddToPool(entity);
 			}
 
@@ -84,17 +81,17 @@ public Poolable GetEntity(Vector3 position, Quaternion rotation, Transform paren
 			return entity;
 		}
 
-		public T GetEntity<T>() where T : Component =>
-			GetEntity().Component as T;
+		public T GetEntity<T>() =>
+			GetEntity().GetComponent<T>();
 
-		public T GetEntity<T>(Transform parent, bool spawnInWorldSpace) where T : Component =>
-			GetEntity(parent, spawnInWorldSpace).Component as T;
+		public T GetEntity<T>(Transform parent, bool spawnInWorldSpace) =>
+			GetEntity(parent, spawnInWorldSpace).GetComponent<T>();
 
-		public T GetEntity<T>(Vector3 position, Quaternion rotation) where T : Component =>
-			GetEntity(position, rotation).Component as T;
+		public T GetEntity<T>(Vector3 position, Quaternion rotation) =>
+			GetEntity(position, rotation).GetComponent<T>();
 
-		public T GetEntity<T>(Vector3 position, Quaternion rotation, Transform parent, bool spawnInWorldSpace) where T : Component =>
-			GetEntity(position, rotation, parent, spawnInWorldSpace).Component as T;
+		public T GetEntity<T>(Vector3 position, Quaternion rotation, Transform parent, bool spawnInWorldSpace) =>
+			GetEntity(position, rotation, parent, spawnInWorldSpace).GetComponent<T>();
 
 		public void ReturnEntity(Poolable entity)
 		{
@@ -114,7 +111,7 @@ private Poolable TakeEntity()
 
 			if (_currentCount == 0)
 			{
-				entity = Object.Instantiate(_prefab, _holder);
+				entity = UnityEngine.Object.Instantiate(_prefab, _holder);
 				entity.SetPool(this);
 
 				return entity;
@@ -124,7 +121,7 @@ private Poolable TakeEntity()
 
 			if (entity == null)
 			{
-				entity = Object.Instantiate(_prefab, _holder);
+				entity = UnityEngine.Object.Instantiate(_prefab, _holder);
 				entity.SetPool(this);
 				_currentCount++;
 			}

GlobalPool.cs.meta

@@ -1,25 +1,48 @@
-using ToolBox.Reactors;
+using Sirenix.OdinInspector;
+using System.Collections.Generic;
+using System.Linq;
+using ToolBox.Reactors;
 using UnityEngine;
 
 namespace ToolBox.Pools
 {
 	[DisallowMultipleComponent]
 	public class Poolable : MonoBehaviour, IReactor
 	{
-		[SerializeField] private Component _component = null;
-		[SerializeField] private Reactor _onBackToPool = null;
-		[SerializeField] private Reactor _onBackFromPool = null;
+		[SerializeField, TabGroup("Global Pool")] private GlobalPool _globalPool = null;
+
+		[SerializeField, TabGroup("Callbacks")] private Reactor _onBackToPool = null;
+		[SerializeField, TabGroup("Callbacks")] private Reactor _onBackFromPool = null;
+
+		[SerializeField, TabGroup("Poolables"), OnValueChanged(nameof(OnPoolablesChange)), ValueDropdown(nameof(GetPoolables)), HideInPlayMode] 
+		private MonoBehaviour[] _possiblePoolables = null;
+
+		[ShowInInspector, HideInEditorMode, TabGroup("Poolables"), ReadOnly]
+		private IPoolable[] _poolables = null;
 
 		public Pool Pool { get; private set; } = null;
-		public Component Component => _component;
 
 		private bool _isPooled = false;
 		private bool _isEnabled = true;
 
 		private void Awake()
 		{
+			if (_globalPool != null)
+			{
+				Pool = _globalPool.Pool;
+				_isPooled = true;
+			}
+
 			_onBackToPool.Setup();
 			_onBackFromPool.Setup();
+
+			int count = _possiblePoolables.Length;
+			_poolables = new IPoolable[count];
+
+			for (int i = 0; i < count; i++)
+				_poolables[i] = _possiblePoolables[i] as IPoolable;
+
+			_possiblePoolables = null;
 		}
 
 		[Button]
@@ -32,6 +55,9 @@ public void ReturnToPool()
 
 			Pool.ReturnEntity(this);
 			_isEnabled = false;
+
+			for (int i = 0; i < _poolables.Length; i++)
+				_poolables[i].Reset();
 		}
 
 		public void ReturnFromPool()
@@ -51,5 +77,15 @@ public void SetPool(Pool pool)
 
 		public void HandleReaction() =>
 			ReturnToPool();
+
+		private void OnPoolablesChange()
+		{
+			IEnumerable<MonoBehaviour> poolables = _possiblePoolables.Where(x => x is IPoolable);
+			poolables = poolables.GroupBy(x => x.GetHashCode()).Select(y => y.First());
+			_possiblePoolables = poolables.ToArray();
+		}
+
+		private IEnumerable<IPoolable> GetPoolables() =>
+			GetComponentsInChildren<IPoolable>();
 	}
 }