In C++, what is an easy-to-use graphics library? It doesn't have to be advanced, just drawing 2D shapes is enough.
If possible, something comparable to the paint-paintcomponent-repaint stuff in Java would be awesome.
The only thing I want to use it for is to draw small circles on a white screen, which refreshes every time, like:
refresh and draw circles at the new positions
You should take a look at SFML. http://www.sfml-dev.org/tutorials/2.1/graphics-draw.php