How to create static background image in OpenGL(GLUT) scene?

Question

I create some scene, and i would like to display some static background image, which would not change from how and what I am doing with the scene.

Answer 1

Usually it means that you can skip clearing your color buffer at the beginning of the scene, instead you set default orthographic projection and render a quad with (-1,-1,0), (-1,+1,0), (+1,+1,0), (+1,-1,0) vertices and apply a texture to this quad.

Then you can set necessary perspective projection and render whatever you want in your scene. The quad will serve you as a background.