GLX available?

NoiseEHC NoiseEHC at freemail.hu
Mon Jan 7 07:11:07 EST 2008


Try to contact him, he ported TinyGL successfully:
http://lists.laptop.org/pipermail/devel/2007-June/005375.html



> As a data point, Doom runs quite fast even at full resolution on a  
> B4. Have not heard reports on getting Quake running. But I suspect  
> that a software renderer hand-optimized towards the XO could be made  
> to work at decent frame rate.
>
>   
The databook of the LX is so low quality that hand optimization requires 
testing everything (including if the published clock counts are matching 
reality) and it has not been done yet. Also the hight cache hit penalty 
and the in-order nature of the Geode means that a different algorithm 
could be required than naively fetching texels while texture mapping. 
Quake requires a preprocessed/prelit BSP tree so unless you want to 
write an FPS it is not a perfect fit. Preprocessing also could take 
hours on an XO (if you want children to design levels).

Just a quick calculation (400x300, 30 fps):
400x300x30 = 3 600 000 pixels/sec filled (with no overdraw)
433 000 000/3 600 000 = 120 clock/pixel (if you do not do anything else 
in the code, but just divide it by 4 because of game logic/geometry 
transform/overdraw)
So you have ~30 clock/pixel and a cache miss takes 25 clocks (if the 
documentation is ok but not tested)...


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