# Glucose

In the spirit of being short and sweet, that fits very well with the concepts of Glucose: 

* it's an OpenGL based acceleration architecture (as XAA and EXA); 
* it uses [[Software/Xgl|Software/Xgl]] code, so it accelerates everything using exactly the same paths as [[Software/Xgl|Software/Xgl]] does, so there's no duplicate code/work; 
* all driver code is limited to just initialising it (a call to _glucoseDriverInit_). 

## Known issues

* Xorg will crash if the number of clients reaches zero. 
* Changes to the screen geometry via RandR extension are not yet supported. 

## Source

Source is only available from Git and for Intel cards. You need to follow the [[instructions to build a modular Xorg|http://www.x.org/wiki/ModularDevelopersGuide]], but using instead: 

* _yuv-porting_ branch from _pixman_ module, 
* _master_ of [[Software/glitz|Software/glitz]] module, 
* _glucose-2_ branch from _xserver_ module, 
* _glucose_ branch from _xf86-video-intel_ module. 
Then add the following line to the _Device_ section of you _xorg.conf_: 
[[!format txt """
  Option  "AccelMethod"  "glucose"
"""]]

## Troubleshooting

If things are slow check on the resulting _/var/log/Xorg.0.log_ for the following (or similar) lines: 
[[!format txt """
 ...
 AIGLX: Loaded and initialized /usr/lib/dri/i915_dri.so
 ...
 intel(0): Using GLUCOSE for acceleration
 ...
"""]]
If either is missing then you're either using glucose with GL software rendering, or no glucose at all. 


## Links

* [[Initial annoucement|http://lists.freedesktop.org/archives/xorg/2006-August/017393.html]]