Finite State Machine 有限状态机

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using?System;
using?System.Collections;
using?System.Collections.Generic;
using?UnityEngine;
?
/**
A?Finite?State?Machine?System?based?on?Chapter?3.1?of?Game?Programming?Gems?1?by?Eric?Dybsand
?
Written?by?Roberto?Cezar?Bianchini,?July?2010
?
?
How?to?use:
? ? ? ? 1.?Place?the?labels?for?the?transitions?and?the?states?of?the?Finite?State?System ?
? ? ? ? 2.?Write?new?class(es)?inheriting?from?FSMState?and?fill?each?one?with?pairs?(transition-state).
? ? ? ? ? ? These?pairs?represent?the?state?S2?the?FSMSystem?should?be?if?while?being?on?state?S1,?a
? ? ? ? ? ? transition?T?is?fired?and?state?S1?has?a?transition?from?it?to?S2.?Remember?this?is?a?Deterministic?FSM.?
? ? ? ? ? ? You?can‘t?have?one?transition?leading?to?two?different?states.
?
? ? ? ? ? ?Method?Reason?is?used?to?determine?which?transition?should?be?fired.
? ? ? ? ? ?You?can?write?the?code?to?fire?transitions?in?another?place,?and?leave?this?method?empty?if?you
? ? ? ? ? ?feel?it‘s?more?appropriate?to?your?project.
?
? ? ? ? ? ?Method?Act?has?the?code?to?perform?the?actions?the?NPC?is?supposed?do?if?it‘s?on?this?state.
? ? ? ? ? ?You?can?write?the?code?for?the?actions?in?another?place,?and?leave?this?method?empty?if?you
? ? ? ? ? ?feel?it‘s?more?appropriate?to?your?project.
?
? ? ? ? 3.?Create?an?instance?of?FSMSystem?class?and?add?the?states?to?it.
?
? ? ? ? 4.?Call?Reason?and?Act?(or?whichever?methods?you?have?for?firing?transitions?and?making?the?NPCs
? ? ? ? ? ? ?behave?in?your?game)?from?your?Update?or?FixedUpdate?methods.
?
? ? ? ? Asynchronous?transitions?from?Unity?Engine,?like?OnTriggerEnter,?SendMessage,?can?also?be?used,?
? ? ? ? just?call?the?Method?PerformTransition?from?your?FSMSystem?instance?with?the?correct?Transition?
? ? ? ? when?the?event?occurs.
?
?
?
THE?SOFTWARE?IS?PROVIDED?"AS?IS",?WITHOUT?WARRANTY?OF?ANY?KIND,?EXPRESS?OR?IMPLIED,?
INCLUDING?BUT?NOT?LIMITED?TO?THE?WARRANTIES?OF?MERCHANTABILITY,?FITNESS?FOR?A?PARTICULAR?PURPOSE?
AND?NON-INFRINGEMENT.?IN?NO?EVENT?SHALL?THE?AUTHORS?OR?COPYRIGHT?HOLDERS?BE?LIABLE?FOR?ANY?CLAIM,?
DAMAGES?OR?OTHER?LIABILITY,?WHETHER?IN?AN?ACTION?OF?CONTRACT,?TORT?OR?OTHERWISE,?ARISING?FROM,?
OUT?OF?OR?IN?CONNECTION?WITH?THE?SOFTWARE?OR?THE?USE?OR?OTHER?DEALINGS?IN?THE?SOFTWARE.
*/
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?
///?<summary>
///?Place?the?labels?for?the?Transitions?in?this?enum.
///?Don‘t?change?the?first?label,?NullTransition?as?FSMSystem?class?uses?it.
///?</summary>
public?enum?Transition
{
? ? NullTransition?=?0,?//?Use?this?transition?to?represent?a?non-existing?transition?in?your?system
}
?
///?<summary>
///?Place?the?labels?for?the?States?in?this?enum.
///?Don‘t?change?the?first?label,?NullTransition?as?FSMSystem?class?uses?it.
///?</summary>
public?enum?StateID
{
? ? NullStateID?=?0,?//?Use?this?ID?to?represent?a?non-existing?State?in?your?system? ? ? ?
}
?
///?<summary>
///?This?class?represents?the?States?in?the?Finite?State?System.
///?Each?state?has?a?Dictionary?with?pairs?(transition-state)?showing
///?which?state?the?FSM?should?be?if?a?transition?is?fired?while?this?state
///?is?the?current?state.
///?Method?Reason?is?used?to?determine?which?transition?should?be?fired?.
///?Method?Act?has?the?code?to?perform?the?actions?the?NPC?is?supposed?do?if?it‘s?on?this?state.
///?</summary>
public?abstract?class?FSMState
{
? ? protected?Dictionary<Transition,?StateID>?map?=?new?Dictionary<Transition,?StateID>();
? ? protected?StateID?stateID;
? ? public?StateID?ID?{?get?{?return?stateID;?}?}
?
? ? public?void?AddTransition(Transition?trans,?StateID?id)
? ? {
? ? ? ? //?Check?if?anyone?of?the?args?is?invalid
? ? ? ? if?(trans?==?Transition.NullTransition)
? ? ? ? {
? ? ? ? ? ? Debug.LogError("FSMState?ERROR:?NullTransition?is?not?allowed?for?a?real?transition");
? ? ? ? ? ? return;
? ? ? ? }
?
? ? ? ? if?(id?==?StateID.NullStateID)
? ? ? ? {
? ? ? ? ? ? Debug.LogError("FSMState?ERROR:?NullStateID?is?not?allowed?for?a?real?ID");
? ? ? ? ? ? return;
? ? ? ? }
?
? ? ? ? //?Since?this?is?a?Deterministic?FSM,
? ? ? ? //? ?check?if?the?current?transition?was?already?inside?the?map
? ? ? ? if?(map.ContainsKey(trans))
? ? ? ? {
? ? ? ? ? ? Debug.LogError("FSMState?ERROR:?State?"?+?stateID.ToString()?+?"?already?has?transition?"?+?trans.ToString()?+?
? ? ? ? ? ? ? ? ? ? ? ? ? ?"Impossible?to?assign?to?another?state");
? ? ? ? ? ? return;
? ? ? ? }
?
? ? ? ? map.Add(trans,?id);
? ? }
?
? ? ///?<summary>
? ? ///?This?method?deletes?a?pair?transition-state?from?this?state‘s?map.
? ? ///?If?the?transition?was?not?inside?the?state‘s?map,?an?ERROR?message?is?printed.
? ? ///?</summary>
? ? public?void?DeleteTransition(Transition?trans)
? ? {
? ? ? ? //?Check?for?NullTransition
? ? ? ? if?(trans?==?Transition.NullTransition)
? ? ? ? {
? ? ? ? ? ? Debug.LogError("FSMState?ERROR:?NullTransition?is?not?allowed");
? ? ? ? ? ? return;
? ? ? ? }
?
? ? ? ? //?Check?if?the?pair?is?inside?the?map?before?deleting
? ? ? ? if?(map.ContainsKey(trans))
? ? ? ? {
? ? ? ? ? ? map.Remove(trans);
? ? ? ? ? ? return;
? ? ? ? }
? ? ? ? Debug.LogError("FSMState?ERROR:?Transition?"?+?trans.ToString()?+?"?passed?to?"?+?stateID.ToString()?+?
? ? ? ? ? ? ? ? ? ? ? ?"?was?not?on?the?state‘s?transition?list");
? ? }
?
? ? ///?<summary>
? ? ///?This?method?returns?the?new?state?the?FSM?should?be?if
? ? ///? ? this?state?receives?a?transition?and?
? ? ///?</summary>
? ? public?StateID?GetOutputState(Transition?trans)
? ? {
? ? ? ? //?Check?if?the?map?has?this?transition
? ? ? ? if?(map.ContainsKey(trans))
? ? ? ? {
? ? ? ? ? ? return?map[trans];
? ? ? ? }
? ? ? ? return?StateID.NullStateID;
? ? }
?
? ? ///?<summary>
? ? ///?This?method?is?used?to?set?up?the?State?condition?before?entering?it.
? ? ///?It?is?called?automatically?by?the?FSMSystem?class?before?assigning?it
? ? ///?to?the?current?state.
? ? ///?</summary>
? ? public?virtual?void?DoBeforeEntering()?{?}
?
? ? ///?<summary>
? ? ///?This?method?is?used?to?make?anything?necessary,?as?reseting?variables
? ? ///?before?the?FSMSystem?changes?to?another?one.?It?is?called?automatically
? ? ///?by?the?FSMSystem?before?changing?to?a?new?state.
? ? ///?</summary>
? ? public?virtual?void?DoBeforeLeaving()?{?}?
?
? ? ///?<summary>
? ? ///?This?method?decides?if?the?state?should?transition?to?another?on?its?list
? ? ///?NPC?is?a?reference?to?the?object?that?is?controlled?by?this?class
? ? ///?</summary>
? ? public?abstract?void?Reason(GameObject?player,?GameObject?npc);
?
? ? ///?<summary>
? ? ///?This?method?controls?the?behavior?of?the?NPC?in?the?game?World.
? ? ///?Every?action,?movement?or?communication?the?NPC?does?should?be?placed?here
? ? ///?NPC?is?a?reference?to?the?object?that?is?controlled?by?this?class
? ? ///?</summary>
? ? public?abstract?void?Act(GameObject?player,?GameObject?npc);
?
}?//?class?FSMState
?
?
///?<summary>
///?FSMSystem?class?represents?the?Finite?State?Machine?class.
///? It?has?a?List?with?the?States?the?NPC?has?and?methods?to?add,
///? delete?a?state,?and?to?change?the?current?state?the?Machine?is?on.
///?</summary>
public?class?FSMSystem
{
? ? private?List<FSMState>?states;
?
? ? //?The?only?way?one?can?change?the?state?of?the?FSM?is?by?performing?a?transition
? ? //?Don‘t?change?the?CurrentState?directly
? ? private?StateID?currentStateID;
? ? public?StateID?CurrentStateID?{?get?{?return?currentStateID;?}?}
? ? private?FSMState?currentState;
? ? public?FSMState?CurrentState?{?get?{?return?currentState;?}?}
?
? ? public?FSMSystem()
? ? {
? ? ? ? states?=?new?List<FSMState>();
? ? }
?
? ? ///?<summary>
? ? ///?This?method?places?new?states?inside?the?FSM,
? ? ///?or?prints?an?ERROR?message?if?the?state?was?already?inside?the?List.
? ? ///?First?state?added?is?also?the?initial?state.
? ? ///?</summary>
? ? public?void?AddState(FSMState?s)
? ? {
? ? ? ? //?Check?for?Null?reference?before?deleting
? ? ? ? if?(s?==?null)
? ? ? ? {
? ? ? ? ? ? Debug.LogError("FSM?ERROR:?Null?reference?is?not?allowed");
? ? ? ? }
?
? ? ? ? //?First?State?inserted?is?also?the?Initial?state,
? ? ? ? //? ?the?state?the?machine?is?in?when?the?simulation?begins
? ? ? ? if?(states.Count?==?0)
? ? ? ? {
? ? ? ? ? ? states.Add(s);
? ? ? ? ? ? currentState?=?s;
? ? ? ? ? ? currentStateID?=?s.ID;
? ? ? ? ? ? return;
? ? ? ? }
?
? ? ? ? //?Add?the?state?to?the?List?if?it‘s?not?inside?it
? ? ? ? foreach?(FSMState?state?in?states)
? ? ? ? {
? ? ? ? ? ? if?(state.ID?==?s.ID)
? ? ? ? ? ? {
? ? ? ? ? ? ? ? Debug.LogError("FSM?ERROR:?Impossible?to?add?state?"?+?s.ID.ToString()?+?
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?"?because?state?has?already?been?added");
? ? ? ? ? ? ? ? return;
? ? ? ? ? ? }
? ? ? ? }
? ? ? ? states.Add(s);
? ? }
?
? ? ///?<summary>
? ? ///?This?method?delete?a?state?from?the?FSM?List?if?it?exists,?
? ? ///? ?or?prints?an?ERROR?message?if?the?state?was?not?on?the?List.
? ? ///?</summary>
? ? public?void?DeleteState(StateID?id)
? ? {
? ? ? ? //?Check?for?NullState?before?deleting
? ? ? ? if?(id?==?StateID.NullStateID)
? ? ? ? {
? ? ? ? ? ? Debug.LogError("FSM?ERROR:?NullStateID?is?not?allowed?for?a?real?state");
? ? ? ? ? ? return;
? ? ? ? }
?
? ? ? ? //?Search?the?List?and?delete?the?state?if?it‘s?inside?it
? ? ? ? foreach?(FSMState?state?in?states)
? ? ? ? {
? ? ? ? ? ? if?(state.ID?==?id)
? ? ? ? ? ? {
? ? ? ? ? ? ? ? states.Remove(state);
? ? ? ? ? ? ? ? return;
? ? ? ? ? ? }
? ? ? ? }
? ? ? ? Debug.LogError("FSM?ERROR:?Impossible?to?delete?state?"?+?id.ToString()?+?
? ? ? ? ? ? ? ? ? ? ? ?".?It?was?not?on?the?list?of?states");
? ? }
?
? ? ///?<summary>
? ? ///?This?method?tries?to?change?the?state?the?FSM?is?in?based?on
? ? ///?the?current?state?and?the?transition?passed.?If?current?state
? ? ///? doesn‘t?have?a?target?state?for?the?transition?passed,?
? ? ///?an?ERROR?message?is?printed.
? ? ///?</summary>
? ? public?void?PerformTransition(Transition?trans)
? ? {
? ? ? ? //?Check?for?NullTransition?before?changing?the?current?state
? ? ? ? if?(trans?==?Transition.NullTransition)
? ? ? ? {
? ? ? ? ? ? Debug.LogError("FSM?ERROR:?NullTransition?is?not?allowed?for?a?real?transition");
? ? ? ? ? ? return;
? ? ? ? }
?
? ? ? ? //?Check?if?the?currentState?has?the?transition?passed?as?argument
? ? ? ? StateID?id?=?currentState.GetOutputState(trans);
? ? ? ? if?(id?==?StateID.NullStateID)
? ? ? ? {
? ? ? ? ? ? Debug.LogError("FSM?ERROR:?State?"?+?currentStateID.ToString()?+? "?does?not?have?a?target?state?"?+?
? ? ? ? ? ? ? ? ? ? ? ? ? ?"?for?transition?"?+?trans.ToString());
? ? ? ? ? ? return;
? ? ? ? }
?
? ? ? ? //?Update?the?currentStateID?and?currentState? ? ? ? ? ? ? ?
? ? ? ? currentStateID?=?id;
? ? ? ? foreach?(FSMState?state?in?states)
? ? ? ? {
? ? ? ? ? ? if?(state.ID?==?currentStateID)
? ? ? ? ? ? {
? ? ? ? ? ? ? ? //?Do?the?post?processing?of?the?state?before?setting?the?new?one
? ? ? ? ? ? ? ? currentState.DoBeforeLeaving();
?
? ? ? ? ? ? ? ? currentState?=?state;
?
? ? ? ? ? ? ? ? //?Reset?the?state?to?its?desired?condition?before?it?can?reason?or?act
? ? ? ? ? ? ? ? currentState.DoBeforeEntering();
? ? ? ? ? ? ? ? break;
? ? ? ? ? ? }
? ? ? ? }
?
? ? }?//?PerformTransition()
?
}?//class?FSMSystem

using?System;
using?System.Collections.Generic;
using?System.Text;
using?UnityEngine;
?
[RequireComponent(typeof(Rigidbody))]
public?class?NPCControl?:?MonoBehaviour
{
? ? public?GameObject?player;
? ? public?Transform[]?path;
? ? private?FSMSystem?fsm;
?
? ? public?void?SetTransition(Transition?t)?{?fsm.PerformTransition(t);?}
?
? ? public?void?Start()
? ? {
? ? ? ? MakeFSM();
? ? }
?
? ? public?void?FixedUpdate()
? ? {
? ? ? ? fsm.CurrentState.Reason(player,?gameObject);
? ? ? ? fsm.CurrentState.Act(player,?gameObject);
? ? }
?
? ? ? ? //?The?NPC?has?two?states:?FollowPath?and?ChasePlayer
? ? ? ? //?If?it‘s?on?the?first?state?and?SawPlayer?transition?is?fired,?it?changes?to?ChasePlayer
? ? ? ? //?If?it‘s?on?ChasePlayerState?and?LostPlayer?transition?is?fired,?it?returns?to?FollowPath
? ? private?void?MakeFSM()
? ? {
? ? ? ? FollowPathState?follow?=?new?FollowPathState(path);
? ? ? ? follow.AddTransition(Transition.SawPlayer,?StateID.ChasingPlayer);
?
? ? ? ? ChasePlayerState?chase?=?new?ChasePlayerState();
? ? ? ? chase.AddTransition(Transition.LostPlayer,?StateID.FollowingPath);
?
? ? ? ? fsm?=?new?FSMSystem();
? ? ? ? fsm.AddState(follow);
? ? ? ? fsm.AddState(chase);
? ? }
}
?
public?class?FollowPathState?:?FSMState
{
? ? private?int?currentWayPoint;
? ? private?Transform[]?waypoints;
?
? ? public?FollowPathState(Transform[]?wp)?
? ? {?
? ? ? ? waypoints?=?wp;
? ? ? ? currentWayPoint?=?0;
? ? ? ? stateID?=?StateID.FollowingPath;
? ? }
?
? ? public?override?void?Reason(GameObject?player,?GameObject?npc)
? ? {
? ? ? ? //?If?the?Player?passes?less?than?15?meters?away?in?front?of?the?NPC
? ? ? ? RaycastHit?hit;
? ? ? ? if?(Physics.Raycast(npc.transform.position,?npc.transform.forward,?out?hit,?15F))
? ? ? ? {
? ? ? ? ? ? if?(hit.transform.gameObject.tag?==?"Player")
? ? ? ? ? ? ? ? npc.GetComponent<NPCControl>().SetTransition(Transition.SawPlayer);
? ? ? ? }
? ? }
?
? ? public?override?void?Act(GameObject?player,?GameObject?npc)
? ? {
? ? ? ? //?Follow?the?path?of?waypoints
? ? ? ? ? ? ? ? //?Find?the?direction?of?the?current?way?point?
? ? ? ? Vector3?vel?=?npc.rigidbody.velocity;
? ? ? ? Vector3?moveDir?=?waypoints[currentWayPoint].position?-?npc.transform.position;
?
? ? ? ? if?(moveDir.magnitude?<?1)
? ? ? ? {
? ? ? ? ? ? currentWayPoint++;
? ? ? ? ? ? if?(currentWayPoint?>=?waypoints.Length)
? ? ? ? ? ? {
? ? ? ? ? ? ? ? currentWayPoint?=?0;
? ? ? ? ? ? }
? ? ? ? }
? ? ? ? else
? ? ? ? {
? ? ? ? ? ? vel?=?moveDir.normalized?*?10;
?
? ? ? ? ? ? //?Rotate?towards?the?waypoint
? ? ? ? ? ? npc.transform.rotation?=?Quaternion.Slerp(npc.transform.rotation,
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? Quaternion.LookRotation(moveDir),
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? 5?*?Time.deltaTime);
? ? ? ? ? ? npc.transform.eulerAngles?=?new?Vector3(0,?npc.transform.eulerAngles.y,?0);
?
? ? ? ? }
?
? ? ? ? //?Apply?the?Velocity
? ? ? ? npc.rigidbody.velocity?=?vel;
? ? }
?
}?//?FollowPathState
?
public?class?ChasePlayerState?:?FSMState
{
? ? public?ChasePlayerState()
? ? {
? ? ? ? stateID?=?StateID.ChasingPlayer;
? ? }
?
? ? public?override?void?Reason(GameObject?player,?GameObject?npc)
? ? {
? ? ? ? //?If?the?player?has?gone?30?meters?away?from?the?NPC,?fire?LostPlayer?transition
? ? ? ? if?(Vector3.Distance(npc.transform.position,?player.transform.position)?>=?30)
? ? ? ? ? ? npc.GetComponent<NPCControl>().SetTransition(Transition.LostPlayer);
? ? }
?
? ? public?override?void?Act(GameObject?player,?GameObject?npc)
? ? {
? ? ? ? //?Follow?the?path?of?waypoints
? ? ? ? ? ? ? ? //?Find?the?direction?of?the?player? ? ? ? ?
? ? ? ? Vector3?vel?=?npc.rigidbody.velocity;
? ? ? ? Vector3?moveDir?=?player.transform.position?-?npc.transform.position;
?
? ? ? ? //?Rotate?towards?the?waypoint
? ? ? ? npc.transform.rotation?=?Quaternion.Slerp(npc.transform.rotation,
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? Quaternion.LookRotation(moveDir),
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? 5?*?Time.deltaTime);
? ? ? ? npc.transform.eulerAngles?=?new?Vector3(0,?npc.transform.eulerAngles.y,?0);
?
? ? ? ? vel?=?moveDir.normalized?*?10;
?
? ? ? ? //?Apply?the?new?Velocity
? ? ? ? npc.rigidbody.velocity?=?vel;
? ? }
?