add unity project

add FSM examples

AI/Assets/Scripts/FSM/ChaseSystem.cs

@@ -0,0 +1,37 @@
+using System;
+using UnityEngine;
+
+namespace DefaultNamespace.FSM
+{
+    public class ChaseSystem : MonoBehaviour, IFiniteStateMachine
+    {
+        [SerializeField] private IState _defaultState;
+        [SerializeField] private PlayerController _player;
+
+        private IState _currentState = null;
+
+        private void Awake()
+        {
+            // _currentState = _defaultState; // isn't working, because an interface can't be serialized by the Unity Serializer
+            _currentState = new IdleState(gameObject, _player, 60.0f);
+        }
+
+        private void Start()
+        {
+            _currentState?.Enter(this);
+        }
+
+        private void Update()
+        {
+            // if (_currentState == null) return;
+            _currentState?.Update(this);
+        }
+
+        public void SetState(IState state)
+        {
+            _currentState.Exit(this);
+            _currentState = state;
+            _currentState.Enter(this);
+        }
+    }
+}