I have never understood and will never understand why so many programming luminaries fell in love with OpenGL. It violates the most important engineering precept that I try to follow when I design a library: minimize hidden state. OpenGL is nothing but hidden state. You have no way to tell what a piece of code is going to render without seeing everything that set up the internal stack beforehand, perhaps thousands of lines away, or in entirely different modules that you might not even have access to.