Does anybody know how to define a smooth transition colored background instead of a constant colored background?
By transition I mean like the one you can see in some CAD packages. You can choose any two colors, one for the top and other for the bottom and there is a transition between them presented on screen.
Draw a square to cover the screen, set color1 for the upper two vertex, and color2 for the bottom two vertex. set glShadeModel(GL_SMOOTH). that will do.