misc fixes for VC4

Keith Packard keithp at keithp.com
Thu Jan 1 22:31:29 PST 2015


Rob Clark <robdclark at gmail.com> writes:

> What about simply not using GL_QUADS for the normal GL paths?  Is
> using quads, vs tri's and a few extra vertices really going to be a
> win on some other hw?  If not, avoiding quads would be a big help for
> freedreno too..

Without quads, you end up replicating a lot of vertices, which means a
lot more data motion from CPU to GPU.

>> The big performance win, though, is fixing copyarea to give the GL
>> information about the area that might be damaged by the operation,
>> using the scissor.  Given that it's negative lines of code and not
>> significant on i965, I think this is a pretty good idea.  I do wonder
>> if we don't want to just always leave scissoring on, like I did to
>> logic op.
>
> I'd implemented a similar thing in XA once upon a time... pretty much
> must-have for tilers..

Do you actually want a closer bounding box on the operation? Given that
we're likely to have generated a very tight bounds when computing
damage, I wonder if rejiggering the API to somehow remember that for the
rendering code could be done?

-- 
-keith
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