Can't get depth testing to work in OpenGL

Question

I use SFML to create the window.

In this screenshot the cube should be behind the pyramid but it just doesn\'t work.

Answer 1

Your code looks okay. I suspect that your window simply does not have a depth buffer. You're using sf::RenderWindow, whose documentation says (emphasis mine):

Simple wrapper for sf::Window that allows easy 2D rendering.

I don't know SFML, but this tutorial suggests to create your window like this:

sf::WindowSettings Settings;
Settings.DepthBits         = 24; // Request a 24 bits depth buffer
Settings.StencilBits       = 8;  // Request a 8 bits stencil buffer
Settings.AntialiasingLevel = 2;  // Request 2 levels of antialiasing
sf::Window App(sf::VideoMode(800, 600, 32), "SFML OpenGL", sf::Style::Close, Settings);

You could set StencilBits and AntialiasingLevel to 0 since this example doesn't need them.