我写了一个有限状态机的模板，因为我要写不同的FSM
1.状态用枚举来代替(便于调试)
2.要运行FSM，只需要setState和updateState(float delta_time)即可
3.用GetState来获取当前状态
4.许多转换都基于定时，因此我实现了方法GetTimeInCurState()
5.执行具体的action在这些方法内BeginState EndState UpdateState
[cpp]
// (c) Francois Guibert, www.frozax.com (@Frozax)
#pragma once
template<typename T>
class fgFSM
{
public:
fgFSM() : _time_in_cur_state(0.0f), _cur_state(-1)
{
}
virtual void BeginState( T state ) {}
virtual void UpdateState( T state ) {}
virtual void EndState( T state ) {}
void SetState( T state )
{
EndState( (T)_cur_state );
_cur_state = state;
_time_in_cur_state = 0.0f;
BeginState( (T)_cur_state );
}
void UpdateFSM( float delta_time )
{
if( _cur_state != -1 )
{
_time_in_cur_state+=delta_time;
UpdateState( (T)_cur_state );
}
}
float GetTimeInCurState() { return _time_in_cur_state; }
T GetState() { return (T)_cur_state; }
private:
float _time_in_cur_state;
int _cur_state;
};
// (c) Francois Guibert, www.frozax.com (@Frozax)
#pragma once
template<typename T>
class fgFSM
{
public:
fgFSM() : _time_in_cur_state(0.0f), _cur_state(-1)
{
}
virtual void BeginState( T state ) {}
virtual void UpdateState( T state ) {}
virtual void EndState( T state ) {}
void SetState( T state )
{
EndState( (T)_cur_state );
_cur_state = state;
_time_in_cur_state = 0.0f;
BeginState( (T)_cur_state );
}
void UpdateFSM( float delta_time )
{
if( _cur_state != -1 )
{
_time_in_cur_state+=delta_time;
UpdateState( (T)_cur_state );
}
}
float GetTimeInCurState() { return _time_in_cur_state; }
T GetState() { return (T)_cur_state; }
private:
float _time_in_cur_state;
int _cur_state;
};
用法：
先建立需要应用到的状态枚举，比如
[cpp]
enum EState
{
STT_OFF = -1, // optional, -1 is the initial state of the fsm
STT_WALK,
STT_RUN,
STT_STOP,
STT_EAT
};
enum EState
{
STT_OFF = -1, // optional, -1 is the initial state of the fsm
STT_WALK,
STT_RUN,
STT_STOP,
STT_EAT
};
然后继承class fgFSM
[cpp]
class ObjectUsingFSM: public fgFSM<EState>
{
public:
// ...
void UpdateState( EState t );
void BeginState( EState t );
void EndState( EState t );
// ...
};
class ObjectUsingFSM: public fgFSM<EState>
{
public:
// ...
void UpdateState( EState t );
void BeginState( EState t );
void EndState( EState t );
// ...
};
该机,结束语：
你可以在你的项目当中免费使用这些代码，这是非常简单又常用的，另外你可以在以后根据需要在在EndState()里面加入GetPrviousState()
GetNextState()等等。。。
