/* * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the * Free Software Foundation; either version 2 of the License, or (at * your option) any later version. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software Foundation, * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * * In addition, as a special exception, the author gives permission to * link the code of this program with the Half-Life Game Engine ("HL * Engine") and Modified Game Libraries ("MODs") developed by Valve, * L.L.C ("Valve"). You must obey the GNU General Public License in all * respects for all of the code used other than the HL Engine and MODs * from Valve. If you modify this file, you may extend this exception * to your version of the file, but you are not obligated to do so. If * you do not wish to do so, delete this exception statement from your * version. * */ #ifndef SIMPLE_STATE_MACHINE_H #define SIMPLE_STATE_MACHINE_H #ifdef _WIN32 #pragma once #endif // Encapsulation of a finite-state-machine state template class SimpleState { public: SimpleState() { m_parent = NULL; } virtual ~SimpleState() {}; virtual void OnEnter(T userData) {}; // when state is entered virtual void OnUpdate(T userData) {}; // state behavior virtual void OnExit(T userData) {}; // when state exited virtual const char *GetName() const = 0; // return state name void SetParent(SimpleState *parent) { m_parent = parent; } SimpleState *GetParent() const { return m_parent; } private: // the parent state that contains this state SimpleState *m_parent; }; // Encapsulation of a finite state machine template class SimpleStateMachine { public: SimpleStateMachine() { m_state = NULL; } void Reset(T userData) { m_userData = userData; m_state = NULL; } // change behavior state - WARNING: not re-entrant. Do not SetState() from within OnEnter() or OnExit() void SetState(S *newState) { if (m_state) m_state->OnExit(m_userData); newState->OnEnter(m_userData); m_state = newState; m_stateTimer.Start(); } // how long have we been in the current state float GetStateDuration() const { return m_stateTimer.GetElapsedTime(); } // return true if given state is current state of machine bool IsState(const S *state) const { return (state == m_state); } // execute current state of machine void Update() { if (m_state) m_state->OnUpdate(m_userData); } /*protected:*/ S *m_state; // current behavior state IntervalTimer m_stateTimer; // how long have we been in the current state T m_userData; }; #endif // SIMPLE_STATE_MACHINE_H