1419876 - Angle full-screen Present pass

Status: RESOLVED FIXED

(Core :: Graphics: WebRender, enhancement, P1)

Description

[Dzmitry Malyshau [:kvark]]

Attachment: 01-present-quad.png

RenderDoc captures show that (when running MotionMark) we are rendering into an off-screen texture, which gets blit to the swapchain right before Present call. This is likely coming from Angle, and I can see that the image is flipped during this flip (may be the reason for a flip in the first place?). It takes surprisingly large amount of GPU time, although I suspect RenderDoc timing just going crazy at this spot...

Anyhow, there should be absolutely no need for this full-screen blit.

Comment 1

[Dzmitry Malyshau [:kvark]]

Glenn found this wonderful link: https://github.com/Microsoft/angle/wiki/Getting-Good-Performance-From-ANGLE#--use-our-render-to-backbuffer-flags
Basically, Microsoft has a patch for disabling this extra pass. We should definitely use it!

Comment 2

[Sotaro Ikeda [:sotaro]]

(In reply to Dzmitry Malyshau [:kvark] from comment #1)
> Glenn found this wonderful link:
> https://github.com/Microsoft/angle/wiki/Getting-Good-Performance-From-ANGLE#-
> -use-our-render-to-backbuffer-flags
> Basically, Microsoft has a patch for disabling this extra pass. We should
> definitely use it!

Created Bug 1421199 for enabling EGL_EXPERIMENTAL_PRESENT_PATH_FAST_ANGLE usage.

Comment 3

[Dzmitry Malyshau [:kvark]]

Confirmed to be fixed by Sotaro's changes.
Thank you!