1712367 - Avoid TexSubImage2DWithoutUnpackSubimage slowpath when using SWGL

Status: RESOLVED FIXED

(Core :: Graphics: WebRender, defect)

Description

[Jeff Muizelaar [:jrmuizel]]

OpenGL ES doesn't support extracting a subimage from the source when using glTexSubImage. The memcpy call from mozilla::gl::TexSubImage2DHelper in https://share.firefox.dev/3yn0d5C suggests we're hitting this.

The best way to avoid it is unclear.

Comment 1

[Jeff Muizelaar [:jrmuizel]]

I talked this through with Glenn and came up with the idea of using our current DataSourceSurface as a scratch buffer. Instead of drawing into the correct place in the tile's DataSourceSurface, we always draw in the top left and make sure the stride = width of the dirty rect. We should then be able to TexSubImage2D from that freshly drawn area.

Comment 2

[Jeff Muizelaar [:jrmuizel]]

Attachment: PoC

Comment 3

[Jeff Muizelaar [:jrmuizel]]

Attachment: Bug 1712367. Avoid TexSubImage ES slow path.

Comment 4

[Kelsey Gilbert [:jgilbert]]

(In reply to Jeff Muizelaar [:jrmuizel] from comment #0)

OpenGL ES doesn't support extracting a subimage from the source when using glTexSubImage. The memcpy call from mozilla::gl::TexSubImage2DHelper in https://share.firefox.dev/3yn0d5C suggests we're hitting this.

"doesn't support efficiently extracting"?

Comment 5

[Sotaro Ikeda [:sotaro]]

Attachment: video with current D116501

When I applied the current D116501 on Wiko sunny2 puls(Mali-400 MP), I sometimes saw cases that part of page colors were inverted between blue and red. I tested on https://www.yahoo.co.jp/

Comment 6

[Sotaro Ikeda [:sotaro]]

:jrmuizel, can you reproduce the problem of comment 3 on your device?

Comment 7

[Sotaro Ikeda [:sotaro]]

By applying the updated patch, the color problem was addressed:) I am going to check more.

Comment 8

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/4521e7060665
Avoid TexSubImage ES slow path. r=jgilbert,sotaro

Comment 9

[Cristian Brindusan [:cbrindusan]]

https://hg.mozilla.org/mozilla-central/rev/4521e7060665