GL provides a set of fully featured functions that support graphics without depending on other graphics systems. These functions include support for input devices, a windowing system, frame buffer configuration and control, immediate and retained mode graphics, and support for basic and advanced 3-D rendering.
GL subroutines provide basic function and are limited in scope; subroutines do not interact in a complex fashion; minimal use is made of stored state; and where possible, the subroutines access hardware functionality directly. (Note that you cannot start a GL and graPHIGS application from the same process ID.)
The following series of programs introduces you to GL functions:
To run GL programs, your system must have an adapter installed that supports GL. The GL prerequisites are discussed in "Hardware and Software Prerequisites". In addition, the AIXwindows server must be actively running. If the X server is not already running, you need to start it. To do this, enter the following at the command line prompt: