Pausable Clock

PausableClock.cpp

#include <SFML/Graphics.hpp>

class PausableClock
{
    sf::Clock m_clock;
    sf::Time m_elapsed;
    bool m_isRunning = false;
    float m_skewFactor = 1.f;

public:
    void start()
    {
        m_clock.restart();
        m_isRunning = true;
    }

    void pause()
    {
        m_elapsed += sf::seconds(m_clock.getElapsedTime().asSeconds() * m_skewFactor);
        m_isRunning = false;
    }

    void reset()
    {
        m_elapsed = sf::Time::Zero;
    }

    bool isRunning()
    {
        return m_isRunning;
    }

    sf::Time getElapsedTime()
    {
        if (m_isRunning)
        {
            m_elapsed += sf::seconds(m_clock.restart().asSeconds() * m_skewFactor);
        }

        return m_elapsed;
    }

    void setSkewFactor(float skewFactor)
    {
        m_skewFactor = skewFactor;
    }
};

int main()
{
    auto window = sf::RenderWindow{sf::VideoMode{500, 200}, "Test"};
    window.setFramerateLimit(60);

    auto font = sf::Font{};
    if (!font.loadFromFile("times.ttf"))
    {
        return -1;
    }

    auto text = sf::Text{"0.0 passed", font, 12u};
    text.setStyle(sf::Text::Bold);

    auto pausableClock = PausableClock{};
    pausableClock.start();
    auto skew = 1.f;

    while (window.isOpen())
    {
        for (auto event = sf::Event{}; window.pollEvent(event);)
        {
            switch (event.type)
            {
            case sf::Event::Closed:
                window.close();
                break;
            case sf::Event::KeyPressed:
                if (event.key.scancode == sf::Keyboard::Scan::Up)
                {
                    skew += 0.1f;
                    pausableClock.setSkewFactor(skew);
                }
                else if (event.key.scancode == sf::Keyboard::Scan::Down)
                {
                    skew -= 0.1f;
                    pausableClock.setSkewFactor(skew);
                }
                else if (event.key.scancode == sf::Keyboard::Scan::Space)
                {
                    if (pausableClock.isRunning())
                    {
                        pausableClock.pause();
                    }
                    else
                    {
                        pausableClock.start();
                    }
                }
                else if (event.key.scancode == sf::Keyboard::Scan::Escape)
                {
                    pausableClock.reset();
                }
                break;
            default:
                break;
            }
        }

        text.setString(std::to_string(pausableClock.getElapsedTime().asSeconds()) + " passed\n(Skew: " + std::to_string(skew) + ")");

        window.clear();
        window.draw(text);
        window.display();
    }
}