[Pixman] [PATCH 1/3] Move miTrapezoids() into fb as fbTrapezoids().

Michel Dänzer michel at daenzer.net
Wed Oct 5 01:32:34 PDT 2011

On Die, 2011-10-04 at 15:52 -0700, Aaron Plattner wrote: 
> This caused a performance regression because previously, miTrapezoids 
> would render its mask image into a scratch pixmap and then perform the 
> final composite using a possibly-accelerated RENDER Composite call. 
> Now, fbTrapezoids does the final composite in software, leading to, for 
> example, http://www.nvnews.net/vbulletin/showthread.php?t=166698
> Of course, I could simply copy the old miTrapezoids implementation into 
> our driver, but it seems hard to believe that our driver is the only one 
> that benefited from the "rasterize in software, composite in hardware" 
> behavior of the old code.  Should I re-add miTrapezoids as a helper that 
> drivers can plug in when they want the old behavior, just revert this 
> change, or go the "only nvidia gets to go fast" copy & paste route?

FWIW, EXA already had a copy of miTrapezoids before this change to avoid
GPU<->CPU ping-pong (GPU clear, CPU rasterization, GPU composition).

Earthling Michel Dänzer           |                   http://www.amd.com
Libre software enthusiast         |          Debian, X and DRI developer

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