Unity —有限状态机FSM系统（2）

FSM状态机

接上篇

PatrolState （巡逻状态）

PatrolState巡逻状态类，继承与FSMState（状态类），在巡逻状态时，当与主角距离比较近时，触发跟随状态，敌人进入跟随状态。

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class PatrolState : FSMState
{
    private List<Transform> paths = new List<Transform>();
    private int index = 0;
    private Transform player;

    public PatrolState(FSMSystem fsm) : base(fsm)
    {
        stateID = StateID.patrol;
        Transform pathTransform = GameObject.Find("path").transform;
        Transform[] chidren = pathTransform.GetComponentsInChildren<Transform>();
        player = GameObject.Find("Player").transform;
        foreach (var item in chidren)
        {
            if (item != pathTransform)
            {
                paths.Add(item);
            }
        }

    }

    public override void Act(GameObject npc)
    {
        npc.transform.LookAt(paths[index].position);     //朝向
        npc.transform.Translate(Vector3.forward * Time.deltaTime * 3);
        if(Vector3.Distance(npc.transform.position,paths[index].position) < 1)
        {
            index++;
            index %= paths.Count;
        }
    }

    public override void Reason(GameObject npc)
    {
        if (Vector3.Distance(player.position, npc.transform.position) < 3)
        {
            fsm.PerformTransition(Transiton.SeePlayer);
        }
    }
}
   

ChaseState （跟随状态）

ChaseState 继承与FSMState（状态类），当敌人距离主角比较远的时候，触发巡逻状态，敌人回到巡逻状态。

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class ChaseState : FSMState
{
    private Transform player;
    public ChaseState(FSMSystem fsm) : base(fsm)
    {
        stateID = StateID.Chase;
        player = GameObject.Find("Player").transform;
    }

    public override void Act(GameObject npc)
    {
        npc.transform.LookAt(player.transform.position);
        npc.transform.Translate(Vector3.forward * Time.deltaTime * 2);
    }

    public override void Reason(GameObject npc)
    {
        if (Vector3.Distance(player.position, npc.transform.position) > 6)
        {
            fsm.PerformTransition(Transiton.LostPlayer);
        }
    }
}

Enemy（敌人类）

Enemy 持有FSMSystem（状态管理类），通过Enemy来注册敌人的状态；

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class Enemy : MonoBehaviour
{
    private FSMSystem fsm;

    private void Awake()
    {
        InitFsm();
    }

    private void InitFsm()
    {
        fsm = new FSMSystem();
        FSMState patroState = new PatrolState(fsm);
        patroState.AddTransition(Transiton.SeePlayer, StateID.Chase);
        FSMState chaseState = new ChaseState(fsm);
        chaseState.AddTransition(Transiton.LostPlayer, StateID.patrol);

        fsm.AddSatte(patroState);
        fsm.AddSatte(chaseState);
    }

    private void Update()
    {
        fsm.Update(this.gameObject);
    }
}

简单的效果

开始处于巡逻状态

靠近，敌人处于跟随主角状态

主角离远，回到巡逻状态