timemanager.cpp

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/***************************************************************************
 *   Copyright (C) 2005-2019 by the FIFE team                              *
 *   http://www.fifengine.net                                              *
 *   This file is part of FIFE.                                            *
 *                                                                         *
 *   FIFE is free software; you can redistribute it and/or                 *
 *   modify it under the terms of the GNU Lesser General Public            *
 *   License as published by the Free Software Foundation; either          *
 *   version 2.1 of the License, or (at your option) any later version.    *
 *                                                                         *
 *   This library 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     *
 *   Lesser General Public License for more details.                       *
 *                                                                         *
 *   You should have received a copy of the GNU Lesser General Public      *
 *   License along with this library; if not, write to the                 *
 *   Free Software Foundation, Inc.,                                       *
 *   51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA          *
 ***************************************************************************/

// Standard C++ library includes
#include <algorithm>
#include <cassert>

// 3rd party library includes
#include <SDL.h>

// FIFE includes
// These includes are split up in two parts, separated by one empty line
// First block: files included from the FIFE root src directory
// Second block: files included from the same folder
#include "util/log/logger.h"

#include "timeevent.h"
#include "timemanager.h"

namespace FIFE {
    static const uint32_t UNDEFINED_TIME_DELTA = 999999;
    static Logger _log(LM_UTIL);

    TimeManager::TimeManager():
        m_current_time (0),
        m_time_delta(UNDEFINED_TIME_DELTA),
        m_average_frame_time(0) {
    }

    TimeManager::~TimeManager() {
    }

    void TimeManager::update() {
        // if first update...
        double avg_multiplier = 0.985;
        if (m_current_time == 0) {
            m_current_time = SDL_GetTicks();
            avg_multiplier = 0;
            m_time_delta = 0;
        } else {
            m_time_delta = m_current_time;
            m_current_time = SDL_GetTicks();
            m_time_delta = m_current_time - m_time_delta;
        }
        m_average_frame_time = m_average_frame_time * avg_multiplier +
            double(m_time_delta) * (1.0 - avg_multiplier);

        // Update live events.
        //
        // It is very important to NOT use iterators (over a vector)
        // here, as an event might add enough events to resize the vector.
        // -> Ugly segfault
        for (size_t i = 0; i < m_events_list.size(); ++i) {
            TimeEvent* event = m_events_list[ i ];
            if( event ) {
                event->managerUpdateEvent(m_current_time);
            }
        }

        // Remove dead events
        std::vector<TimeEvent*>::iterator it;
        it = std::remove( m_events_list.begin(), m_events_list.end(), static_cast<TimeEvent*>(0));
        m_events_list.erase( it, m_events_list.end());
    }

    void TimeManager::registerEvent(TimeEvent* event) {
        // Register.
        m_events_list.push_back(event);
    }

    void TimeManager::unregisterEvent(TimeEvent* event) {
        // Unregister.
        for (size_t i = 0; i < m_events_list.size(); ++i) {
            TimeEvent*& event_i = m_events_list[ i ];
            if( event_i == event) {
                event_i = 0;
                return;
            }
        }
    }

    uint32_t TimeManager::getTime() const {
        return m_current_time;
    }

    uint32_t TimeManager::getTimeDelta() const {
        return m_time_delta;
    }

    double TimeManager::getAverageFrameTime() const {
        return m_average_frame_time;
    }

    void TimeManager::printStatistics() const {
        FL_LOG(_log, LMsg("Timers: ") << m_events_list.size());
    }

} //FIFE