new loop

void Application::loop() {
    using HRC = std::chrono::high_resolution_clock;
    using Nano = std::chrono::nanoseconds;
    using TimePoint = std::chrono::time_point<Nano>;

    Stopwatch sw{};
    constexpr Nano ONE_SECOND{ 1000000000L };
    long long sum{};

    while( looping ) {
        Nano timestep{ ONE_SECOND / tickrate };
        sum += sw.time();
        sw.start();

        /* Ignore this part
        //check for GameState swaps.
        if (gameStateQueue != nullptr && currentGameState != gameStateQueue) {
            currentGameState = gameStateQueue;
            currentGameState->init();
        }
        */

        /* Ignore this part
        SDL_Event e{};
        while (SDL_PollEvent(&e)) {
            currentGameState->event_SDL(e);
        }
        */

        while (sum >= timestep.count()) {
            currentGameState->tick();

            static Stopwatch tempWatch{};
            std::cout << "tick was called " << tempWatch.time() / 1000000000.0L << std::endl;
            tempWatch.start();

            sum -= timestep.count();
        }
    }
}



////////////////////////////////////////////////////////////////////////////////////////////////////
    STOPWATCH.HPP
////////////////////////////////////////////////////////////////////////////////////////////////////
#pragma once
#include <chrono>

/*
 * Wrapper class for <chrono>
 */
class Stopwatch {
private:
    std::chrono::time_point<std::chrono::high_resolution_clock> beginning;
    bool started = false;

public:
    Stopwatch();
    Stopwatch(const Stopwatch& other);

    // Starts the timer.
    void start();

    /*
     * returns the elapsed time since starting in microseconds.
     * If the timer has not been started, the timer is started and the function returns 0LL.
     */
    long long time();

    virtual ~Stopwatch();
};

////////////////////////////////////////////////////////////////////////////////////////////////////
    STOPWATCH.CPP
////////////////////////////////////////////////////////////////////////////////////////////////////

#include "Stopwatch.hpp"
#include <chrono>

namespace {
    using HRC = std::chrono::high_resolution_clock;
    using Nano = std::chrono::nanoseconds;
}

Stopwatch::Stopwatch()
    : beginning{} {}

Stopwatch::Stopwatch(const Stopwatch& other)
    : beginning{ other.beginning } {}

void Stopwatch::start() {
    beginning = HRC::now();
    started = true;
}

long long Stopwatch::time() {
    Nano interval = HRC::now() - beginning;
    if (started) {
        return interval.count();
    } else {
        start();
        return 0LL;
    }
}

Stopwatch::~Stopwatch() = default;