chore: initial commit

Assets/Feel/MMTools/Accessories/MMInstantiation/MMRandomInstantiator.cs

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+using System.Collections;
+using System.Collections.Generic;
+using UnityEngine;
+using UnityEngine.SceneManagement;
+
+namespace MoreMountains.Tools
+{
+	/// <summary>
+	/// Add this class to an empty object, bind a few prefabs into its RandomPool slots, and it'll instantiate one of them at its position/rotation on Start or Awake
+	/// You can also call its InstantiateRandomObject method at any time, and it'll instantiate another random object on demand, 
+	/// potentially destroying the previous one if you decide so
+	/// </summary>
+	public class MMRandomInstantiator : MonoBehaviour
+	{
+		/// the possible start modes
+		public enum StartModes { Awake, Start, None }
+
+		[Header("Random instantiation")]
+		/// whether this instantiator should auto trigger on Awake, Start, or never
+		public StartModes StartMode = StartModes.Awake;
+		/// the name to give to the instantiated object
+		public string InstantiatedObjectName = "RandomInstantiated";
+		/// if this is true, the instantiated object will be parented to the spawner
+		public bool ParentInstantiatedToThisObject = true;
+		/// if this is true, every time InstantiateRandomObject is called, any previously instantiated object will be destroyed
+		public bool DestroyPreviouslyInstantiatedObject = true;
+		/// the list containing all the objects that can potentially be instantiated
+		public List<GameObject> RandomPool;
+
+		[Header("Test")]
+		/// a test button for your inspector
+		[MMInspectorButton("InstantiateRandomObject")]
+		public bool InstantiateButton;
+
+		protected GameObject _instantiatedGameObject;
+
+		/// <summary>
+		/// On awake we instantiate if needed
+		/// </summary>
+		protected virtual void Awake()
+		{
+			if (StartMode == StartModes.Awake)
+			{
+				InstantiateRandomObject();
+			}
+		}
+
+		/// <summary>
+		/// On Start we instantiate if needed
+		/// </summary>
+		protected virtual void Start()
+		{
+			if (StartMode == StartModes.Start)
+			{
+				InstantiateRandomObject();
+			}
+		}
+
+		/// <summary>
+		/// Spawns a random object from the pool of choices
+		/// </summary>
+		public virtual void InstantiateRandomObject()
+		{
+			// if the pool is empty we do nothing and exit
+			if (RandomPool.Count == 0)
+			{
+				return;
+			}
+
+			// we destroy our previous object if needed
+			if (DestroyPreviouslyInstantiatedObject)
+			{
+				if (_instantiatedGameObject != null)
+				{
+					DestroyImmediate(_instantiatedGameObject);
+				}
+			}
+
+			// pick a random object and instantiates it
+			int randomIndex = Random.Range(0, RandomPool.Count);
+			_instantiatedGameObject = Instantiate(RandomPool[randomIndex], this.transform.position, this.transform.rotation);
+			SceneManager.MoveGameObjectToScene(_instantiatedGameObject, this.gameObject.scene);
+			_instantiatedGameObject.name = InstantiatedObjectName;
+			if (ParentInstantiatedToThisObject)
+			{
+				_instantiatedGameObject.transform.SetParent(this.transform);
+			}
+		}
+	}
+}