GLX
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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 often 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 DRI: the client program can then directly access the graphics hardware.
On a running X server, a lot of diagnostic information about GLX, including the 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 comes with GLX (and Mesa and DRI) since version 4.0.
External links
- OpenGL Graphics with the X Window System (http://www.opengl.org/documentation/specs/glx/glx1.3.pdf)