把具体的行为代码（移动、攻击）写在 Enemy 里面，决策（仇恨）则用 FSM 状态机来实现。
AI 状态流程图
将流程图拆解为以下几个状态后，编写对应的代码：
AIEnemy.cs
/** Email: me@dreamyouxi.com
using FSM to peocess lite AI */
using UnityEngine;
using System.Collections;
namespace AIEnemy
{
public class FSMBase : GAObject
{
public Enemy host = null;
public FSMMachine machine = null;
public override void UpdateMS()
{
}
public override void OnEnter()
{
}
public override void OnExit()
{
}
public override bool Init()
{
base.Init();
return true;
}
// —— helper function
public void ChangeTo<T>() where T : FSMBase, new()
{
machine.ChangeTo<T>();
}
}
/// <summary>
/// 锁定塔状态
/// 该状态下只会攻击塔
/// </summary>
public class LockTower : FSMBase
{
public override void UpdateMS()
{
if (host.target == null)
{
this.ChangeTo<Free>();
}
}
public override void OnEnter()
{
host.bullet_atk1_info.AddHitTarget(host.target);//锁定只攻击 Tower
}
public override void OnExit()
{
}
}
/// <summary>
/// 自由状态
/// 目标死亡 或者 刚出生 才会在该状态下
/// </summary>
public class Free : FSMBase
{
public override void UpdateMS()
{
if (BuildingMgr.ins.GetBuildingsCount() > 0)
{ //存在塔
ArrayList list = HeroMgr.ins.GetHeros();
bool has_hero = false;
if (list.Count > 0)
{
foreach (Hero h in list)
{
if (host.target_distance > h.ClaculateDistance(host))
{//范围内 有玩家
has_hero = true;
break;
}
}
}
if (has_hero) // 仇恨范围内有玩家
{//锁定玩家攻击
if (host.AI_SearchNearestTarget(list, true)) ;
{
this.ChangeTo<LockHero>();
}
}
else // 仇恨范围内没有玩家，直接进入半锁定塔状态
{
this.ChangeTo<LockHalfTowerBefore>();
}
}
else
{//不存在塔，直接锁定最近玩家攻击
if (host.AI_SearchNearestTarget(HeroMgr.ins.GetHeros(), true))
{
this.ChangeTo<LockHero>();
}
else
{//没有任何攻击目标 随机走动
if (Utils.random_frameMS.Next(0, 300) == 5 || dir == -1)
{
Terrain terrain = AppMgr.GetCurrentApp<BattleApp>().GetCurrentWorldMap().GetTerrain();
Vector2 to = new Vector2(Utils.random_frameMS.Next((int)(terrain.limit_x_left * 1000), (int)(terrain.limit_x_right * 1000)) / 1000f, Utils.random_frameMS.Next((int)(terrain.limit_z_down * 1000), (int)(terrain.limit_z_up * 1000)) / 1000f);
dir = (int)Utils.GetAngle(host.pos, to);
}
host.dir = dir;// Utils.random_frameMS.Next(0, 361);
}
}
}
public override void OnEnter()
{
if (host != null)
{//目标没死
host.bullet_atk1_info.hit_targets.Clear();//清空目标
}
}
public override void OnExit()
{
}
private int dir = -1;
}
/// <summary>
/// 半锁定塔 状态后
/// 在该状态下 只有被玩家攻击才会 攻击玩家 否则 一直攻击塔
/// </summary>
public class LockHalfTowerAfter : FSMBase
{
public override void UpdateMS()
{
if (host.target == null || host == null)
{//如果塔 失效
ChangeTo<Free>();
return;
}
}
public override void OnEnter()
{
}
public override void OnDispose()
{
EventDispatcher.ins.RemoveEventListener(this, Events.ID_BATTLE_ENTITY_BEFORE_TAKEATTACKED);
}
public override void OnExit()
{
}
public override void OnEvent(int type, object userData)
{
if (this.IsInValid()) return;
if (type == Events.ID_BATTLE_ENTITY_BEFORE_TAKEATTACKED)
{
AttackInfo info = userData as AttackInfo;
if (info.target as Enemy != host) return;
{//已经命中 塔 后 被攻击 会切换，在搜索阶段 被命中 也会进入锁定hero
//自己被命中
if (info.ownner.IsMaxTarget() == false)
{
host.target = info.ownner;
machine.ChangeTo<LockHero>();
}
}
}
}
public override bool Init()
{
base.Init();
EventDispatcher.ins.AddEventListener(this, Events.ID_BATTLE_ENTITY_BEFORE_TAKEATTACKED);
return true;
}
}
/// <summary>
/// 半锁定塔 命中前，
/// 该状态 下 仇恨指向 塔 但未命中塔 在此期间 如果范围内 有玩家 会更改为锁定玩家攻击
/// </summary>
public class LockHalfTowerBefore : FSMBase
{
public override void UpdateMS()
{
if (has_find)//已找到塔
{
if (has_shoot == false)
{ //发起攻击 塔
if (host.target == null || host == null)
{
ChangeTo<Free>();
return;
}
this.Shoot();
}
}
else
{
if (host.AI_SearchNearestTarget(BuildingMgr.ins.GetBuildings(), false))//寻找最近的建筑作为目标
{//找到 目标
has_find = true;
}
else
{//搜索失败 ，进入Free
machine.ChangeTo<Free>();
return;
}
}
//在此期间如果仇恨范围内有玩家，那么切换仇恨为玩家
ArrayList list = HeroMgr.ins.GetHeros();
bool has_hero = false;
if (list.Count > 0)
{
foreach (Hero h in list)
{
if (host.target_distance > h.ClaculateDistance(host))
{//范围内 有玩家
has_hero = true;
break;
}
}
}
if (has_hero) // 仇恨范围内有玩家
{//锁定玩家攻击
if (host.AI_SearchNearestTarget(list, true)) ;
{
this.ChangeTo<LockHero>();
return;
}
}
}
public override void OnEnter()
{
has_shoot = false;
has_find = false;
}
public override void OnExit()
{
if (info_backup != null)
{
host.bullet_atk1_info = info_backup;
info_backup = null;
}
}
private void Shoot()
{
info_backup = host.bullet_atk1_info;
// host.atk = true;
BulletConfigInfo info = BulletConfigInfo.Create();
info.AddHitTarget(host.target);
info.plistAnimation = "";
info.distance = 0.2f;
info.distance_atk = 1f;
info.number = 1;
info.collider_size = new Vector3(2f, 2f, 2f);
info.AddHitTarget(host.target);
info._OnTakeAttack = (Bullet bullet, object userData) =>
{
//命中后
ChangeTo<LockHalfTowerAfter>();
};
has_shoot = true;
host.bullet_atk1_info = info;
}
public override bool Init()
{
base.Init();
return true;
}
private BulletConfigInfo info_backup = null;
private bool has_shoot = false;
private bool has_find = false;
}
/// <summary>
/// 锁定玩家状态
/// 该状态只会攻击玩家 直到 玩家死亡
/// </summary>
public class LockHero : FSMBase
{
public override void UpdateMS()
{
if (host.target == null)
{
this.ChangeTo<Free>();
}
}
public override void OnEnter()
{
host.bullet_atk1_info.AddHitTarget(host.target);//锁定只攻击 Hero
}
public override void OnExit()
{
}
}
/// <summary>
/// FSM 状态机
/// </summary>
public class FSMMachine : GAObject
{
public override void UpdateMS()
{
if (host.ai_type != AIEnemyType.FSM) return;
if (pause) return;
if (current_fsm != null)
{
current_fsm.UpdateMS();
// Debug.Log("FSM: " + current_fsm.GetType().ToString());
}
}
public override void OnEnter()
{
}
public override void OnExit()
{
}
public override bool Init()
{
base.Init();
current_fsm = Utils.Create<Free>();
current_fsm.machine = this;
current_fsm.host = host;
current_fsm.Init();
return true;
}
public void ChangeTo(FSMBase fsm)
{
if (current_fsm != null)
{
current_fsm.OnExit();
current_fsm.LazyDispose();
}
fsm.host = host;
fsm.machine = this;
fsm.OnEnter();
current_fsm = fsm;
}
public void ChangeTo<T>() where T : FSMBase, new()
{
FSMBase fsm = Utils.Create<T>();
fsm.Init();
this.ChangeTo(fsm);
}
public void Pause()
{
pause = true;
}
public void Resume()
{
pause = false;
}
public bool IsPause()
{
return pause;
}
private bool pause = false;
FSMBase current_fsm = null;
public Enemy host = null;
}
}下篇为行为树，源代码：https://git.oschina.net/dreamyouxi/XYGame