[Player] Add AI Pathfinding on a 2D grid to the player character

Assets/External/AstarPathfindingProject/Utilities/UnityReferenceHelper.cs

@@ -0,0 +1,40 @@
+using UnityEngine;
+
+namespace Pathfinding {
+	[ExecuteInEditMode]
+	/// <summary>
+	/// Helper class to keep track of references to GameObjects.
+	/// Does nothing more than to hold a GUID value.
+	/// </summary>
+	[HelpURL("http://arongranberg.com/astar/docs/class_pathfinding_1_1_unity_reference_helper.php")]
+	public class UnityReferenceHelper : MonoBehaviour {
+		[HideInInspector]
+		[SerializeField]
+		private string guid;
+
+		public string GetGUID () {
+			return guid;
+		}
+
+		public void Awake () {
+			Reset();
+		}
+
+		public void Reset () {
+			if (string.IsNullOrEmpty(guid)) {
+				guid = Pathfinding.Util.Guid.NewGuid().ToString();
+				Debug.Log("Created new GUID - " + guid, this);
+			} else if (gameObject.scene.name != null) {
+				// Create a new GUID if there are duplicates in the scene.
+				// Don't do this if this is a prefab (scene.name == null)
+				foreach (UnityReferenceHelper urh in FindObjectsOfType(typeof(UnityReferenceHelper)) as UnityReferenceHelper[]) {
+					if (urh != this && guid == urh.guid) {
+						guid = Pathfinding.Util.Guid.NewGuid().ToString();
+						Debug.Log("Created new GUID - " + guid, this);
+						return;
+					}
+				}
+			}
+		}
+	}
+}