[Mesa-dev] [PATCH 04/11] st/mesa: Use Array._DrawVAO in st_atom_array.c.

[Mathias Fröhlich]

Hi Erik,

> > On Monday, 26 November 2018 19:39:50 CET Erik Faye-Lund wrote:
> > > I know this is *very* late notice, but this commit broke Super Tux
> > > Kart
> > > on VirGL. Both the player-models as as well as the level data
> > > renders
> > > with gibberish vertex positions since this commit.
> > > 
> > > The fix that Rob Clark did on top does not fix the problem (and
> > > shouldn't have; VirGL doesn't use NIR).
> > 
> > Do you have any idea how I can reproduce that issue with the least
> > effort?
> > 
> 
> Sadly, no. I run a qemu VM where I run super tux cart. It's a rather
> convoluted setup, I'm afraid. If you're interested in that Robert Foss
> has written an article about how to set something like this up here:
> https://memcpy.io/virtualizing-gpu-access.html
> 
> ...But I totally understand if this is asking a bit too much. I can
> help out with any information you need...

Thanks!
That, just means that looking into has to wait at least until the weekend.
Probably even later.

And thanks for looking up the constants.
The effective binding computation depends on these and may change
the set up combined buffer objects. So these are interesting to know.

I have been putting a lot of internal verification into the code paths
especially _mesa_update_vao_derived_arrays contains a larger
#ifndef NDEBUG part that may tell us if there is something unexpected.

I assume you did run also with asserts enabled in the build?

I can observe some flicker in supertuxcart on i965. The nvidia blob seems
not to flicker here. Also when running through valgrind I don't get that flicker
on i965. Is that flashing - initially looked like a lighting effect of the game to
me - what you observe too?

Also what are the game options? Are shaders enabled in some way?
What does change if you change the game settings?
May be that gives us some hints?

best
Mathias