GLX
GLX (acronym for "OpenGL Extension to the X Window System") provides the glue connecting OpenGL and the X Window System: it enables OpenGL 3D programs to draw to a window of the X Window System. GLX consists of three parts:
- An API that is used to write OpenGL programs for the X Window System.
- An extension of the X protocol, which allows the client (the OpenGL application) to send 3D rendering commands to the X server (the software responsible for the display). Client and server may run on different computers.
- An extension of the X server that decodes the received rendering commands and passes them on to a hardware accelerated 3D graphics card or renders them in software using the Mesa library (which is much slower).
If client and server run on the same computer and a 3D accelerated graphics with suitable driver is available, the latter two components can be bypassed by GLX visuals the system supports, can be extracted with the command "glxinfo". The demo utility "glxgears" provides a rough estimate of the speed of the 3D rendering setup.
GLX was created by Silicon Graphics and is currently in version 1.3. The free X server XFree86 has comes with GLX (and Mesa and DRI) since version 4.0.
