timer.h

/*
    This file is part of Nori, a simple educational ray tracer
 
    Copyright (c) 2015 by Wenzel Jakob
 
    Nori is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License Version 3
    as published by the Free Software Foundation.
 
    Nori 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, see <http://www.gnu.org/licenses/>.
*/
 
#if !defined(__NORI_TIMER_H)
#define __NORI_TIMER_H
 
#include <nori/common.h>
#include <chrono>
 
NORI_NAMESPACE_BEGIN
 
class Timer {
public:
    Timer() { reset(); }
 
    void reset() { start = std::chrono::system_clock::now(); }
 
    double elapsed() const {
        auto now = std::chrono::system_clock::now();
        auto duration = std::chrono::duration_cast<std::chrono::milliseconds>(now - start);
        return (double) duration.count();
    }
 
    std::string elapsedString(bool precise = false) const {
        return timeString(elapsed(), precise);
    }
 
    double lap() {
        auto now = std::chrono::system_clock::now();
        auto duration = std::chrono::duration_cast<std::chrono::milliseconds>(now - start);
        start = now;
        return (double) duration.count();
    }
 
    std::string lapString(bool precise = false) {
        return timeString(lap(), precise);
    }
private:
    std::chrono::system_clock::time_point start;
};
 
NORI_NAMESPACE_END
 
#endif /* __NORI_TIMER_H */