FSM

状态抽象：
1.进入状态
2.退出状态
3.在状态中（Update）

C层抽象：
1.管理子状态
2.负责状态间的交换
3.一个状态一个类
4.状态只能通过C层跳转
5.使用枚举代替数值，最后设置一个maxvalue

---

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

/// <summary>
/// 状态脚本，一个状态一个类
/// </summary>
public class OrcIdle : FSMBase
{
Animator animator;

public OrcIdle() { }

public OrcIdle(Animator ani)
{
    animator = ani;

}


public override void OnEnter()
{
    animator.SetInteger("StateIndex", 1);
    Debug.Log("进入Idle");
}

public override void OnLeave()
{
    Debug.Log("退出Idle");
}

public override void Update()
{
    Debug.Log("在Idle中");
}

}
public class OrcJump : FSMBase
{
Animator animator;
//Func的泛型是返回值类型，UnityAction的泛型是参数类型
UnityAction<sbyte> callBack;

public OrcJump() { }

public OrcJump(Animator ani,UnityAction<sbyte> tmpBack)
{
    animator = ani;
    callBack = tmpBack;
}

public float timeCount;
public override void OnEnter()
{
    animator.SetInteger("StateIndex", 2);
    Debug.Log("进入Jump");
}

public override void OnLeave()
{
    Debug.Log("退出Jump");
}

public override void Update()
{
    timeCount += Time.deltaTime;
    if (timeCount > 1)
    {
        timeCount = 0;
        callBack((sbyte)OrcCtrl.AnimalState.Idle);
    }
    Debug.Log("在Jump中");
}

}
public class OrcRun : FSMBase
{
Animator animator;

public OrcRun() { }

public OrcRun(Animator ani)
{
    animator = ani;

}


public override void OnEnter()
{
    animator.SetInteger("StateIndex", 3);
    Debug.Log("进入run");
}

public override void OnLeave()
{
    Debug.Log("退出run");
}

public override void Update()
{
    Debug.Log("在run中");
}

}

/// <summary>
/// 状态类的父类，抽象出3个函数
/// </summary>
public abstract class FSMBase {

public abstract void OnEnter();

public abstract void OnLeave();

public abstract void Update();

}
/// <summary>
/// 状态管理类
/// </summary>
public class FsmManager
{

//数组比list快
FSMBase[] allState;

public FsmManager(){}
/// <summary>
/// 状态总数
/// </summary>
sbyte stateIndex;
/// <summary>
/// 当前状态索引
/// </summary>
sbyte currentIndex;

public FsmManager(byte stateCount)
{
    allState = new FSMBase[stateCount];
    stateIndex = -1;
    currentIndex = -1;
}
/// <summary>
/// 添加
/// </summary>
/// <param name="state"></param>
public void AddState(FSMBase state)
{
    if (stateIndex < allState.Length)
    {
        stateIndex++;

        allState[stateIndex] = state;

    }
}
/// <summary>
/// 交换
/// </summary>
/// <param name="stateNuber"></param>
public void ChangeState(sbyte stateNuber)
{
    stateNuber =(sbyte)( stateNuber % allState.Length);
    if (currentIndex != -1)
    {
        allState[currentIndex].OnLeave();

    currentIndex = stateNuber;

        allState[currentIndex].OnEnter();

    }
    else
    {
        currentIndex = stateNuber;

        allState[currentIndex].OnEnter();
    }    
}
/// <summary>
/// 在状态中
/// </summary>
public void Update()
{
    if (currentIndex != -1)
    {
        allState[currentIndex].Update();
    }
}

}

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
/// <summary>
/// C层
/// </summary>
public class OrcCtrl : MonoBehaviour {

FsmManager fsmManager;


/// <summary>
/// 所有状态， MaxValue为状态总数
/// </summary>
public enum AnimalState
{
    Idle,
    Jump,
    Run,
    MaxValue
}

// Use this for initialization
void Start () {
    fsmManager = new FsmManager((byte)AnimalState.MaxValue);

    Animator tmpAni = transform.GetComponent<Animator>();

    OrcIdle tmpIdle = new OrcIdle(tmpAni);

    fsmManager.AddState(tmpIdle);

    OrcJump tmpJump = new OrcJump(tmpAni, ChangeState);

    fsmManager.AddState(tmpJump);

    OrcRun tmpRun = new OrcRun(tmpAni);

    fsmManager.AddState(tmpRun);
}

// Update is called once per frame
void Update () {
    if (Input.GetKey(KeyCode.A))
    {
        fsmManager.ChangeState((sbyte)AnimalState.Jump);
    }
    fsmManager.Update();
}

public void ChangeState(sbyte stateIndex)
{
    fsmManager.ChangeState(stateIndex);
}

}