/**********************************************************************
 *                                                                    *
 * tgt - Tiny Graphics Toolbox                                        *
 *                                                                    *
 * Copyright (C) 2005-2013 Visualization and Computer Graphics Group, *
 * Department of Computer Science, University of Muenster, Germany.   *
 * <http://viscg.uni-muenster.de>                                     *
 *                                                                    *
 * This file is part of the tgt library. This library is free         *
 * software; you can redistribute it and/or modify it under the terms *
 * of the GNU Lesser General Public License version 2.1 as published  *
 * by the Free Software Foundation.                                   *
 *                                                                    *
 * 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 in the file "LICENSE.txt" along with this library.         *
 * If not, see <http://www.gnu.org/licenses/>.                        *
 *                                                                    *
 **********************************************************************/

#ifndef TGT_FRAMECOUNTER_H
#define TGT_FRAMECOUNTER_H

#include <cmath>
#include <iostream>

#include "tgt/stopwatch.h"

namespace tgt {

/**
 *  This class can be used to calculate the framerate using the Stopwatch class.
 *  The rate variable specifies the number of frames that are averaged for the
 *  calculation; a higher rate means more significant numbers but it naturally
 *  also lessens the number of updates.
 */
class FrameCounter {
protected:
    Stopwatch stopwatch_;
    Stopwatch speedtimer_;
    float averagefps_;
    int rate_;
    int speedrate_;
    int counter_;
    int speedcounter_;
    float speedfactor_;

public:

    /// The Constructor; the standard update rate is 50.
    FrameCounter(int rate = 50, int speedrate = 0)
        : stopwatch_(Stopwatch()),
          speedtimer_(Stopwatch()),
          averagefps_(0.f),
          rate_(rate),
          speedrate_(speedrate),
          counter_(0),
          speedcounter_(0),
          speedfactor_(0.3f
    ) {
    }

    /// This should be called every frame.
    void update();

    /// This functions is called to get the current average framerate
    float getFPS();
};

}

#endif //TGT_FRAMECOUNTER_H_
