[Mesa-dev] mesa/st: support lowering user-clip-planes automatically

[Ilia Mirkin]

On Fri, Oct 18, 2019 at 9:07 AM Ilia Mirkin <imirkin at alum.mit.edu> wrote:
>
> On Fri, Oct 18, 2019 at 9:04 AM Erik Faye-Lund
> <erik.faye-lund at collabora.com> wrote:
> >
> > On Fri, 2019-10-18 at 08:57 -0400, Ilia Mirkin wrote:
> > > On Fri, Oct 18, 2019 at 8:51 AM Erik Faye-Lund
> > > <erik.faye-lund at collabora.com> wrote:
> > > > On Thu, 2019-10-17 at 22:24 -0400, Ilia Mirkin wrote:
> > > > > In the meanwhile (unless you plan on taking up Jason's
> > > > > suggestion),
> > > > > might I recommend some assert's for the unhandled cases so that
> > > > > there
> > > > > are no surprises?
> > > >
> > > > Good idea. I sent a MR for it here:
> > > >
> > > > https://gitlab.freedesktop.org/mesa/mesa/merge_requests/2380
> > >
> > > Not sure that approach works, esp with SSO.
> >
> > If so, wouldn't that already be a problem with the existing
> > lower_depth_clamp-stuff, then? I mean, I just lifted the logic from
> > there...
>
> Yeah, that looks bogus. I'm moderately sure that checking
> "st->vp/gp/tep" at LinkShader time is wrong. Marek can probably
> confirm.

Actually it might be crazy enough to work -- you'll generate the
(potentially) wrong shader at LinkShader time, but then at draw time,
the key will be regenerated (to look up the appropriate shader, at
which time st->gp/etc *are* reliable), you'll discover that you're
missing the right shader, and recompile. Not exactly ideal, but also
not broken.

  -ilia