using UnityEngine;
using System.Collections;
using System;
using System.Collections.Generic;
//无论是NPC还是Player都有很多状态，在状态切换的时候为了使得程序显得清晰明了，采用了状态机制
//首先实际状态都是继承自某个状态抽象类的，这个抽象类定义了进入，退出一个状态虚方法
//定义了检测环境是否发生状态改变，以及在该状态下执行的动作的抽象方法
// 该实例主要涉及到一个NPC在指定的位置进行巡逻，当看到Playeer的时候切换状态进入追逐Player状态public enum Translate    //如果进入一个新的状态，需要一些触发，比如NPC看到了Player，由巡逻状态进入跟踪状态
{                        NullTrans,SeePlayer,LosePlayer}public enum StateID     //每个状态都应该有一个ID,作为识别改状态的标志
{ NullState,Chaseingplayer,FollowPath}public abstract class FMS_State    //定一个抽象类
{private StateID id;            //定一个状态ID作为变量来标识public StateID ID{set { id = value; }get { return id; }}private Dictionary<Translate, StateID> map = new Dictionary<Translate, StateID>();    //在某一状态下，事件引起了触发进入另一个状态
// 于是我们定义了一个字典，存储的便是触发的类型，以及对应要进入的状态public void addDictionary(Translate tr, StateID id1)  //向字典里添加{if (tr == Translate.NullTrans){Debug.LogError("Null Trans is not allower to adding into");return;}if (ID == StateID.NullState){Debug.LogError("Null State id not ~~~");return;}if (map.ContainsKey(tr))              //NPC  任何时候都只能出于一种状态，所以一旦定义了一个触发的枚举类型，对应的只能是接下来的一种状态{Debug.LogError(id1.ToString() + "is already added to");return;}map.Add(tr, id1);}public void deleateDictionary(Translate tr) //删除字典里存储的一个状态{if (tr == Translate.NullTrans){Debug.LogError("TransNull is not allowed to delate");return;}if (map.ContainsKey(tr)){map.Remove(tr);return;}Debug.LogError(tr.ToString() + "are not exist");}public StateID GetOutState(Translate tr)  //由状态的触发枚举类型返回一个对应的状态类型{if (map.ContainsKey(tr)){// Debug.Log("Translate " + tr + "State" + map[tr]);return map[tr];}return StateID.NullState;}public virtual void DoBeforeEnter() { }    //虚方法public virtual void DoBeforeMoveing() { }public abstract void Reason(GameObject player, GameObject NPC); //  抽象方法public abstract void Act(GameObject player, GameObject NPC);}

using UnityEngine;
using System.Collections;
using System;
using System.Collections.Generic;
public class Follow_State:FMS_State  //派生出一个巡逻的类
{private GameObject[] waypoints;    //在这些位置巡逻private int currentWayPoint;    public Follow_State(GameObject[] ob){waypoints= ob;  currentWayPoint = 0;ID = StateID.FollowPath;        //当前状态的ID}public override void Reason(GameObject player, GameObject NPC)    //与环境交互，来判断是否需要状态切换{RaycastHit hit;if(Physics.Raycast(NPC.transform.position,NPC.transform.forward,out hit ,15)){if(hit.transform.tag=="Player"){FMS_Machine_Manage.GetInstance.changeState(Translate.SeePlayer);}}}public override void Act(GameObject player, GameObject NPC)   //在该状态下改做点什么呢{Vector3 vel = NPC.rigidbody.velocity;Vector3 dir =waypoints[currentWayPoint].transform.position- NPC.transform.position;if(dir.magnitude<1){currentWayPoint++;// Debug.Log("currentwappoint " + currentWayPoint);if(currentWayPoint>=waypoints.Length){currentWayPoint = 0;}}else{vel = dir.normalized*10;NPC.transform.rotation = Quaternion.Lerp(NPC.transform.rotation, Quaternion.LookRotation(dir), Time.deltaTime * 5);NPC.transform.eulerAngles = new Vector3(0, NPC.transform.localEulerAngles.y, 0);}NPC.rigidbody.velocity = vel;}public override void DoBeforeMoveing(){}public override void DoBeforeEnter(){}
}

using UnityEngine;
using System.Collections;
using System;
using System.Collections.Generic;public class Chaseing_State : FMS_State {   //派生出了一个追逐类public Chaseing_State(){ID = StateID.Chaseingplayer;   //定义  状态ID}public override void Reason(GameObject player, GameObject NPC){if(Vector3.Distance(player.transform.position,NPC.transform.position)>=5){FMS_Machine_Manage.GetInstance.changeState(Translate.LosePlayer);}}public override void Act(GameObject player, GameObject NPC){Vector3 vel = NPC.rigidbody.velocity;Vector3 moveDir = player.transform.position - NPC.transform.position;NPC.transform.rotation = Quaternion.Lerp(NPC.transform.rotation, Quaternion.LookRotation(moveDir), Time.deltaTime * 5);NPC.transform.eulerAngles = new Vector3(0, NPC.transform.eulerAngles.y, 0);vel = moveDir * 3;NPC.rigidbody.velocity = vel;}    }

using UnityEngine;
using System.Collections;
using System;
using System.Collections.Generic;
//状态管理类，对状态进行管理public class FMS_Machine_Manage:MonoBehaviour
{private List<FMS_State> states;//存储所有状态的的Listprivate FMS_State currentState;  //当前状态private StateID currentStateID;//当前状态IDpublic FMS_State CurrentState {set { currentState = value; }get { return currentState; } }public StateID CurrentStateID {set { currentStateID = value; }get { return currentStateID; } }public GameObject player;public GameObject[] path;public GameObject NPC;private static  FMS_Machine_Manage instance;public static  FMS_Machine_Manage GetInstance{get {if (instance == null){// instance = new FMS_Machine_Manage(); GameObject n = new GameObject();n.name = "FMS_Machine_Manage"; instance = n.AddComponent<FMS_Machine_Manage>() as FMS_Machine_Manage;}return instance;}}public void UpdateFunction(){CurrentState.Reason(player, NPC);CurrentState.Act(player, NPC);}public void Revert(){ }void Awake(){states = new List<FMS_State>();   //初始化NPC = GameObject.FindGameObjectWithTag("NPC");player = GameObject.FindGameObjectWithTag("Player");path = GameObject.FindGameObjectsWithTag("path");}public void MakeFMSMachine(){Follow_State follow = new Follow_State(path);follow.addDictionary(Translate.SeePlayer, StateID.Chaseingplayer);Chaseing_State chase = new Chaseing_State();chase.addDictionary(Translate.LosePlayer, StateID.FollowPath);GetInstance. AddFmsState(follow);GetInstance. AddFmsState(chase);}public void AddFmsState(FMS_State s)//注册所有状态{if (s == null){Debug.LogError(" Null reference is not allowed");}if (states.Count == 0){states.Add(s);                   //设置默认状态（important）;currentState = s;currentStateID = s.ID;return;}foreach (FMS_State state in states){if (state == s){Debug.LogError(s.ID.ToString() + "has already been added");return;}}states.Add(s);}public void delateFmsState(StateID id){if (id == StateID.NullState){Debug.LogError("NullStateID is not allowed for a real state");return;}foreach (FMS_State state in states){if (state.ID == id){states.Remove(state);return;}}}public void changeState(Translate tr)           //更改状态{if (tr == Translate.NullTrans){Debug.LogError("NullTransition is not allowed for a real transition");return;}//if (currentState.GetOutState(tr) == StateID.NullState)//{//    Debug.Log("translate" + "          " + tr + "           " + currentState.GetOutState(tr)+"         "+CurrentStateID);//    Debug.LogError("1234");//    return;//}StateID id = CurrentState.GetOutState(tr);   //当前状态会进入的新的状态currentStateID = id;//    Debug.Log("Prives" + Prives.ID);foreach (FMS_State state in states)          //通过注册的所有状态，进行搜索来获取要进入的状态实例{if (currentStateID == state.ID){CurrentState.DoBeforeMoveing();     //退出状态前，留下点什么，比如挥舞下手臂currentState = state;CurrentState.DoBeforeEnter();     //进入状态break;}}}}

using UnityEngine;
using System.Collections;
using System;
using System.Collections.Generic;public class NPC_Control : MonoBehaviour {public void Start(){FMS_Machine_Manage.GetInstance.MakeFMSMachine();}public void FixedUpdate(){FMS_Machine_Manage.GetInstance.UpdateFunction();}}