[ENH][VM] making FreeCell redraw 20% faster...
John M McIntosh
johnmci at mac.com
Tue Jul 8 00:24:12 UTC 2003
> When you run the FreeCell demo it seems on the powerpc that
> BitBltSimulation>>alphaSourceBlendBits16
> chews a lot of cycles, say 8.7% of the total time.
>
> Well I noticed that in
> BitBltSimulation>> dither32To16: threshold:
> that it does something interesting, why it grabs the r g b bytes and
> mangles them into a 16 bit word. But really at each step we have 8
> bits of data with 4 bits for threshold information to result in 4 bits
> of output.
>
> {Yes, well it's late maybe my math is wrong}
>
> Gee can you say a lookup table (4096 elements of 4 bits (however 8
> will do)),
Attached is the changeset which creates the 4096 byte table and uses
it to greatly improve performance.
Someone needs to check the interpreter simulator, I couldn't make it
work out of the box. So I'm not
sure if this changeset works for it.
--
========================================================================
===
John M. McIntosh <johnmci at smalltalkconsulting.com> 1-800-477-2659
Corporate Smalltalk Consulting Ltd. http://www.smalltalkconsulting.com
========================================================================
===
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