Unity 状态机

Enemy状态以及切换图

程序架构

• 接口

public interface IState 
{
    void OnEnter(); //进入状态时

    void OnUpdate();//执行状态时

    void OnExit(); //退出状态时
}

• 接口实现及状态切换类

public class IdleState : IState
{
    private FSM manager;
    private Parameter parameter;


    public float timer;
    public IdleState(FSM manager)
    {
        this.manager = manager;
        this.parameter = manager.parameter;
    }

    public void OnEnter()
    {
        parameter.animator.Play("Idle");
    }

    public void OnUpdate()
    {
        timer += Time.deltaTime; //加上上一帧经过的时间


        if(parameter.target != null &&
            parameter.target.position.x >= parameter.chasePoints[0].position.x &&
            parameter.target.position.x <= parameter.chasePoints[1].position.x)
        {
            manager.TransitionState(StateType.React);  //发现敌人，切换为反应状态
        }
        if(timer >= parameter.idleTime) //达到状态机设置好的时间
        {
            manager.TransitionState(StateType.Patrol);  //转换为巡逻状态
        }
    }

    public void OnExit()
    {
        timer = 0; //退出时计时器清0
    }
}
...

• 状态机注册和切换函数类

public enum StateType
{
    Idle, Patrol, Chase, React, Attack, Hit, Death
}

public class FSM : MonoBehaviour
{

    private IState currentState;  //当前状态
    private Dictionary<StateType, IState> states = new Dictionary<StateType, IState>(); //注册状态字典

    public Parameter parameter;
    void Start()
    {
        //注册状态
        states.Add(StateType.Idle, new IdleState(this));
        states.Add(StateType.Patrol, new PatrolState(this));
        states.Add(StateType.Chase, new ChaseState(this));
        states.Add(StateType.React, new ReactState(this));
        states.Add(StateType.Attack, new AttackState(this));
        states.Add(StateType.Hit, new HitState(this));
        states.Add(StateType.Death, new DeathState(this));

        TransitionState(StateType.Idle);  //设置初始状态

        parameter.animator = transform.GetComponent<Animator>(); //设置动画控制器
    }

    void Update()
    {
        currentState.OnUpdate(); //在当前状态中，持续执行当前的函数
    }

    public void TransitionState(StateType type)
    {
        if (currentState != null)
            currentState.OnExit();    //退出当前状态
        currentState = states[type];
        currentState.OnEnter();  //进入新状态
    }
    ...
}