[Gllug] Faster maths?

Adrian McMenamin adrian at newgolddream.dyndns.info
Fri Mar 9 16:31:38 UTC 2007


On Fri, March 9, 2007 4:25 pm, salsaman wrote:
> Richard Jones wrote:
>
>>There's a fast, high-quality implementation of this algorithm in the
>>source code to xv.  Unfortunately it has a non-free license ...
>>

Is it? Quite a lot of the code seems BSD type licenced, but I haven't
looked through all of it and clearly there is a charge for something or
other - but its all in C and I am writing perl anyway, so not sure what
the legal position is...

>>
> Well, I already posted one algorithm you could use: 3d cube mapping. But
> if you want to  ignore that and calculate the inverse sqrt quickly, use
> the hack from ID software:
>
> http://www.codemaestro.com/reviews/review00000105.html
>
> Gabriel.
>

Actually, Gabriel, not sure how practical your algorithm is, as the
efficency of the median cut is that you decide which axes along which to
cut by shrinking every box to the minimum size and then cutting that.



-------------- next part --------------
-- 
Gllug mailing list  -  Gllug at gllug.org.uk
http://lists.gllug.org.uk/mailman/listinfo/gllug


More information about the GLLUG mailing list