[Mesa-dev] INTEL_map_texture on i915/i965
tapani.palli at intel.com
Fri Aug 17 05:50:05 UTC 2018
On 08/17/2018 07:37 AM, Jason Ekstrand wrote:
> On Thu, Aug 16, 2018 at 10:39 PM Matt Turner <mattst88 at gmail.com
> <mailto:mattst88 at gmail.com>> wrote:
> On Thu, Aug 16, 2018 at 5:50 PM Jason Ekstrand <jason at jlekstrand.net
> <mailto:jason at jlekstrand.net>> wrote:
> > If that's true then the extension makes no sense other than maybe
> "we're a
> > UMA, we can make things cheap." I think it's more likely that the
> > is to use a fenced map through the GTT to do the detiling. That
> said, given
> > how sketchy GTT maps are, it's still a pretty questionable
> extension at
> > best and something we don't want to commit to going forward.
> Why are you speculating about it instead of just reading the extension?
> Replying to e-mails from my phone? I know, not a good excuse.
> This extension allows to create textures with 'linear' layout
> which allows
> for simplified access on user side (potentially sacrificing some
> performance during texture sampling).
> Yeah, that's pretty bad. I mean, there probably are uses such as if
> you're doing piles of CPU-side rendering. If someone really badly wants
> that trade-off, maybe it's worth implementing but I'm still a skeptic.
One use-case (at least on GLES side with EGL_KHR_lock_surface*) is to
stream video data to a texture without having to do copy. Maybe using
texture buffer objects gives this same/similar benefit (?)
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