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C-/C++-Quelltext

#ifndef FPS_HPP
#define FPS_HPP
#include <chrono>
#include <ostream>

class FPS
{
public:
    FPS();

    unsigned int operator()(double weight=0.05);
    friend std::ostream& operator<<(std::ostream &lhs, FPS& rhs);

private:
    std::chrono::nanoseconds spf();

private:
    typedef std::chrono::time_point<std::chrono::system_clock> snap;
    snap start;
    snap _end;
    double lastend;
};
#endif

C-/C++-Quelltext

#include "FPS.hpp"

FPS::FPS() : start(std::chrono::system_clock::now()), _end(std::chrono::system_clock::now()), lastend(.0)
{
    
}

std::ostream& operator<<(std::ostream &lhs, FPS& rhs)
{
    return lhs << rhs();
}

std::chrono::nanoseconds FPS::spf()
{
    _end = std::chrono::system_clock::now();
    const std::chrono::nanoseconds time(_end-start);
    start = std::chrono::system_clock::now();
    return time;
}

unsigned int FPS::operator()(double weight)
{
    //Update every 100 milliseconds
    if(std::chrono::duration_cast<std::chrono::milliseconds>(_end-start).count()>=100)
    {
        double sec = 60000./static_cast<double>(std::chrono::duration_cast<std::chrono::milliseconds>(spf()).count());
        double temp = static_cast<unsigned int>(sec * (1-weight) + lastend * weight);
        lastend = temp;
    }
    else
        _end = std::chrono::system_clock::now();
    return lastend;
}