Walking professor_no_hat

#include <SFML/Graphics.hpp>
#include<chrono>

class Animation
{
public:
    Animation ( ) = default;
    Animation ( int x, int y, int width, int height )
    {
        texture.loadFromFile ( "professor_walk_cycle_no_hat.png" );
        for (int i = 0; i < nFrames; i++)
        {
            frames[i] = { x + i * width,y ,width ,height };
        }
    }
    void ApplyToSprite ( sf::Sprite& s, bool isMove ) const
    {
        s.setTexture ( texture );
        if (isMove == true)
            s.setTextureRect ( frames[iFrame] );
        else
            s.setTextureRect ( frames[0] );
    }
    void Update ( float dt )
    {
        time += dt;
        while (time >= holdTime)
        {
            time -= holdTime;
            Advance ( );
        }
    }
private:
    void Advance ( )
    {
        if (++iFrame >= nFrames)
        {
            iFrame = 1;
        }
    }
private:
    static constexpr int nFrames = 9;
    static constexpr float holdTime = 0.08f;
    sf::Texture texture;
    sf::IntRect frames[nFrames];
    int iFrame = 0;
    float time = 0.0f;
};

class Character
{
private:
    enum class AnimationIndex
    {
        WalkingUp,
        WalkingDown,
        WalkingLeft,
        WalkingRight,
        Count
    };
public:
    Character ( const sf::Vector2f& pos )
        :
        pos ( pos )
    {
        sprite.setTextureRect ( { 0,0,64,64 } );
        animations[int ( AnimationIndex::WalkingUp )] = Animation ( 0, 0, 64, 64 );
        animations[int ( AnimationIndex::WalkingDown )] = Animation ( 0, 128, 64, 64 );
        animations[int ( AnimationIndex::WalkingLeft )] = Animation ( 0, 64, 64, 64 );
        animations[int ( AnimationIndex::WalkingRight )] = Animation ( 0, 192, 64, 64 );
    }
    void Draw ( sf::RenderTarget& rt ) const
    {
        rt.draw ( sprite );
    }
    void SetDirection ( const sf::Vector2f& dir )
    {
        vel = dir * speed;
        if (dir.x > 0.0f)
        {
            curAnimation = AnimationIndex::WalkingRight;
        }
        else if (dir.x < 0.0f)
        {
            curAnimation = AnimationIndex::WalkingLeft;
        }
        else if (dir.y < 0.0f)
        {
            curAnimation = AnimationIndex::WalkingUp;
        }
        else if (dir.y > 0.0f)
        {
            curAnimation = AnimationIndex::WalkingDown;
        }
    }
    void Update ( float dt )
    {
        pos += vel * dt;
        animations[int ( curAnimation )].Update ( dt );
        if(vel.x == 0 && vel.y == 0)
            animations[int ( curAnimation )].ApplyToSprite ( sprite, false );
        else
            animations[int ( curAnimation )].ApplyToSprite ( sprite, true );
        sprite.setPosition ( pos );
    }
private:
    static constexpr float speed = 100.0f;
    sf::Vector2f pos;
    sf::Vector2f vel = {0.0f,0.0f};
    sf::Sprite sprite;
    Animation animations[int ( AnimationIndex::Count )];
    AnimationIndex curAnimation = AnimationIndex::WalkingDown;
};


int main()
{
    // Create the main window
    sf::RenderWindow window(sf::VideoMode(800, 600), "SFML window");

    Character fucker ( { 100.0f,100.0f } );

    // timepoint 4 delta time measurement
    auto tp = std::chrono::steady_clock::now ( );


    // Start the game loop
    while (window.isOpen())
    {
        // Process events
        sf::Event event;
        while (window.pollEvent(event))
        {
            // Close window: exit
            if (event.type == sf::Event::Closed)
                window.close();
        }

        // get dt
        float dt;
        {
            const auto new_tp = std::chrono::steady_clock::now ( );
            dt = std::chrono::duration<float> ( new_tp - tp ).count ( );
            tp = new_tp;
        }



        // handle input
        sf::Vector2f dir = { 0.0f,0.0f };
        if (sf::Keyboard::isKeyPressed ( sf::Keyboard::Up )) {
            dir.y -= 1.0;
        }
        if (sf::Keyboard::isKeyPressed ( sf::Keyboard::Down )) {
            dir.y += 1.0;
        }
        if (sf::Keyboard::isKeyPressed ( sf::Keyboard::Left )) {
            dir.x -= 1.0;
        }
        if (sf::Keyboard::isKeyPressed ( sf::Keyboard::Right )) {
            dir.x += 1.0;
        }
        fucker.SetDirection ( dir );

        //update fucker
        fucker.Update ( dt );




        // Clear screen
        window.clear();
        // Draw the sprite
        fucker.Draw ( window );
        // Update the window
        window.display();
    }
    return EXIT_SUCCESS;
}