1249483 - Don't clear RGBX readpixels' X channel to 1.0 ourselves

Status: RESOLVED FIXED

(Core :: Graphics: CanvasWebGL, defect)

Description

[Kelsey Gilbert [:jgilbert]]

Attachment: 0001-Stop-filling-A-with-1.0-on-readback-from-no-alpha.patch

We should probably not bother doing this.

In particular, we will not be able to do this in WebGL 2 for PBOs.

I believe this was an ancient driver workaround, but I can't find what it was for exactly.

The Try run is clean, though this doesn't have Android runs, and has spurious unrelated errors:
https://treeherder.mozilla.org/#/jobs?repo=try&revision=77a7e32d7999

Comment 1

[Jeff Muizelaar [:jrmuizel]]

(In reply to Jeff Gilbert [:jgilbert] from comment #0)
> Created attachment 8721089 [details] [diff] [review]
> 0001-Stop-filling-A-with-1.0-on-readback-from-no-alpha.patch
> 
> We should probably not bother doing this.
> 
> In particular, we will not be able to do this in WebGL 2 for PBOs.
> 
> I believe this was an ancient driver workaround, but I can't find what it
> was for exactly.
> 
> The Try run is clean, though this doesn't have Android runs, and has
> spurious unrelated errors:
> https://treeherder.mozilla.org/#/jobs?repo=try&revision=77a7e32d7999

This came from:
https://bugzilla.mozilla.org/show_bug.cgi?id=912196#c36

Which is relatively recent. Can you remember why you wrote that?

Comment 2

[Kelsey Gilbert [:jgilbert]]

(In reply to Jeff Muizelaar [:jrmuizel] from comment #1)
> (In reply to Jeff Gilbert [:jgilbert] from comment #0)
> > Created attachment 8721089 [details] [diff] [review]
> > 0001-Stop-filling-A-with-1.0-on-readback-from-no-alpha.patch
> > 
> > We should probably not bother doing this.
> > 
> > In particular, we will not be able to do this in WebGL 2 for PBOs.
> > 
> > I believe this was an ancient driver workaround, but I can't find what it
> > was for exactly.
> > 
> > The Try run is clean, though this doesn't have Android runs, and has
> > spurious unrelated errors:
> > https://treeherder.mozilla.org/#/jobs?repo=try&revision=77a7e32d7999
> 
> This came from:
> https://bugzilla.mozilla.org/show_bug.cgi?id=912196#c36
> 
> Which is relatively recent. Can you remember why you wrote that?

This is not where it originally came from. You can see in the cset that I'm really just moving code around.

Comment 3

[Jeff Muizelaar [:jrmuizel]]

Comment on attachment 8721089 [details] [diff] [review]
0001-Stop-filling-A-with-1.0-on-readback-from-no-alpha.patch

Review of attachment 8721089 [details] [diff] [review]:
-----------------------------------------------------------------

Right.

Comment 4

[Pulsebot]

https://hg.mozilla.org/integration/mozilla-inbound/rev/cf3f2dc292d5

Comment 5

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/mozilla-central/rev/cf3f2dc292d5