Introducing OpenGL

OpenGL Introduction

The OpenGL graphics system is a software interface to graphics
hardware. (The GL stands for Graphics Library.) It allows you to create
interactive programs that produce color images of moving three-
dimensional objects. With OpenGL, you can control computer-graphics
technology to produce realistic pictures or ones that depart from reality in
imaginative ways. OpenGL is available on many different platforms and
works with many different window systems.

OpenGL is designed to complement window systems, not duplicate their
functionality. Therefore, OpenGL performs geometric and image
rendering in two and three dimensions, but it does not manage windows
or handle input events.

However, the basic definitions of most window systems don't support a
library as sophisticated as OpenGL, with its complex and diverse pixel
formats, including depth, stencil, and accumulation buffers, as well as
double-buffering. For most window systems, some routines are added to
extend the window system to support OpenGL. The common extension
for different windowing systems are as: GLX (for X window system), AGL
(for extension to the Apple Macintosh), PGL (for IBM OS/2 Warp), WGL
(for Microsoft Windows family).

GLUT has become a popular library for OpenGL programmers, because
it standardizes and simplifies window and event management. GLUT has
been ported atop a variety of OpenGL implementations, including both the
X Window System and Microsoft Windows family.