Now you have a working SFML window, it’s time to draw something. In the previous example we just created a basic SFML window, which doesn’t support drawing SFML objects (but can be used with other rendering backends if you so choose). To draw with SFML, we need to create an sf::RenderWindow object instead. Thankfully this is just as simple:
sf::Window window({800,800}, "My first RenderWindow");
Now we can start drawing! SFML has built in support for drawing simple coloured shapes, and most tutorials start by drawing the famous green circle. So let’s start by creating an sf::CircleShape object, big enough to fill the window. We also set the fill colour to green
auto size = window.getSize();
sf::CircleShape circle(size.x / 2.f);
circle.setFillColor(sf::Color::Green);
Now we’ve created the shape object, we have to draw it. All drawing in SFML should follow the same cycle: clear the window, draw all the objects then display those objects in the window. So to draw our circle, we simply need to do this in our main loop while the window is open
window.clear();
window.draw(circle);
window.display();
Anything which inherits from the sf::Drawable class can be drawn in this way.