[Mesa-dev] [PATCH] mesa/st: swap order of clear() and clear_with_quad()

[Rob Clark]

On Tue, Nov 13, 2018 at 5:25 PM Eric Anholt <eric at anholt.net> wrote:
>
> Rob Clark <robdclark at gmail.com> writes:
>
> > If we can't clear all the buffers with pctx->clear() (say, for example,
> > because of ColorMask), push the buffers we *can* clear with pctx->clear()
> > first.  Tilers want to see clears coming before draws to enable fast-
> > paths, and clearing one of the attachments with a quad-draw first
> > confuses that logic.
>
> Oh, nice!
>
> Reviewed-by: Eric Anholt <eric at anholt.net>
>
> Though it feels pretty silly that the ->clear() caller needs a
> clear_with_quad implementation when the ->clear() implementation in the
> driver also needs a clear_with_quad implementation for non-fast-cleared
> buffers.  :/

hmm, so perhaps one easy option is to change pctx->clear() to return a
boolean, so driver can return false to ask the state tracker to do a
clear_with_quad()..  maybe that would be a first step towards allowing
driver to handle clears w/ colormask and possibly scissor (although
for the later, plus
glInvalidateFramebuffer()/glInvalidateSubFramebuffer(), I was thinking
of pctx->invalidate_surface()/pctx->invalidate_sub_surface()).

But either way, I guess this patch is a simple stop-gap solution.

BR,
-R