Compositing simple GL scene with a large backing store is slower than expected (greggman doodles canvas-backing-resize.html)

• Component: WebGL
• Status: NEW ---

[Kimmo Kinnunen]

Compositing simple GL scene with a large backing store is slower than expected (greggman doodles canvas-backing-resize.html)

https://github.com/greggman/doodles/blob/master/test/canvas-backing-resize/canvas-backing-resize.html

greggman:

55fps Chrome, 18fps Safari. It's just drawing a single quad

It's a MacBook Pro (16-inch, 2019)
MacOS 12.2, safari can be any version.
Also my display prefs are set to scaled , 1 res higher than 1 to 1


Chrome is using ATI (discrete). But, forcing Chrome to use Intel Chrome is 12fps and Safari is 4-5fps.
Also just for fun, Canvas2D doing the same thing is 40fps.
Turning off antialiasing on the WebGL one goes up to 20fps

John Cunningham:
That’s strange, I have a 3440x1440 screen and a 5k one and neither shows low FPS on ANGLE metal in safari
 I am on an M1 device, perhaps it’s intel/amd specific. I’ll boot up one later and try.

[Radar WebKit Bug Importer]

<rdar://problem/89131458>