1125445 - VertexTexture demo renders incorrectly with ANGLE

Status: RESOLVED FIXED

(Core :: Canvas: WebGL, defect, major)

Description

[Jeff Gilbert [:jgilbert]]

http://floooh.github.io/oryol/VertexTexture.html

Works fine if you disable ANGLE, and fall back to native GL.

Comment 1

[Jeff Gilbert [:jgilbert]]

Attachment: 0002-Only-do-backbuffer-workaround-if-against-backbuffer.patch

Man, past-me was obviously an idiot. :)

Comment 2

[Dan Glastonbury (:kamidphish) | needinfo me]

Comment on attachment 8554956 [details] [diff] [review]
0002-Only-do-backbuffer-workaround-if-against-backbuffer.patch

Review of attachment 8554956 [details] [diff] [review]:
-----------------------------------------------------------------

::: dom/canvas/WebGLContext.h
@@ +1524,4 @@
>          const bool mNeedsChange;
>  
>          static bool NeedsChange(WebGLContext& webgl) {
> +            return !webgl.mBoundDrawFramebuffer &&

Can you right a quick comment to explain what the check is here?

Comment 3

[Jeff Gilbert [:jgilbert]]

Attachment: 0002-Only-do-backbuffer-workaround-if-against-backbuffer.patch

r=kamidphish

Comment 4

[Jeff Muizelaar [:jrmuizel]]

Are there tests for this?

Comment 5

[Jeff Gilbert [:jgilbert]]

(In reply to Jeff Muizelaar [:jrmuizel] from comment #4)
> Are there tests for this?

There will be, but I'm not going to hold up landing this for tests.
I'll make some tests to prevent us from backsliding, though.

Comment 6

[Jeff Gilbert [:jgilbert]]

I should note that there are tests for this code, but I only tested the case where we're rendering into the webgl backbuffer.

Comment 7

[Jeff Gilbert [:jgilbert]]

Attachment: alpha-read.diff (37 and older)

Approval Request Comment
[Feature/regressing bug #]: Bug 1048108
[User impact if declined]: Bad rendering WebGL content that relies on intermediate techniques. (rendering to the alpha channel in a draw call against a framebuffer)
[Describe test coverage new/current, TreeHerder]: Planned.
[Risks and why]: No risk. It's a one-line correction of clear, but incorrect logic.
[String/UUID change made/needed]: none

Comment 11

[Loic]

[Tracking Requested - why for this release]: recent regression since FF35

Comment 12

[Milan Sreckovic [:milan] (needinfo for best results)]

(In reply to Jeff Gilbert [:jgilbert] from comment #6)
> I should note that there are tests for this code, but I only tested the case
> where we're rendering into the webgl backbuffer.

Can we add the test that would have caught this?

Comment 13

[Jeff Gilbert [:jgilbert]]

 https://hg.mozilla.org/integration/mozilla-inbound/rev/dfe54b1d8ac2

Comment 14

[Jeff Gilbert [:jgilbert]]

(In reply to Milan Sreckovic [:milan] from comment #12)
> (In reply to Jeff Gilbert [:jgilbert] from comment #6)
> > I should note that there are tests for this code, but I only tested the case
> > where we're rendering into the webgl backbuffer.
> 
> Can we add the test that would have caught this?

Yes, comment #5 has me committing to adding tests for this, but not holding up the roll-out of the regression fix on producing tests.

Comment 15

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/dfe54b1d8ac2

Comment 18

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/releases/mozilla-aurora/rev/1a8e41dad9fe
https://hg.mozilla.org/releases/mozilla-beta/rev/eea6117858b5

Comment 19

[Luke]

This fix only worked for my Nvidia GTX 650, but did not resolve the issue on older hardware. See Bug 1109708.

On my older laptop and desktop with older ATI hardware in Nightly 38.0a1 (2015-01-29), the following duplicates of this bug only display a black window:

http://floooh.github.io/oryol/VertexTexture.html
http://codepen.io/anon/pen/XJMQwV
http://jsfiddle.net/f17Lz5ux/1316/

Comment 20

[Jeff Gilbert [:jgilbert]]

(In reply to Luke from comment #19)
> This fix only worked for my Nvidia GTX 650, but did not resolve the issue on
> older hardware. See Bug 1109708.
> 
> On my older laptop and desktop with older ATI hardware in Nightly 38.0a1
> (2015-01-29), the following duplicates of this bug only display a black
> window:
> 
> http://floooh.github.io/oryol/VertexTexture.html
> http://codepen.io/anon/pen/XJMQwV
> http://jsfiddle.net/f17Lz5ux/1316/

Ok, this is a different bug then. Can you open a new one, or link to an existing bug for this?

Comment 23

[Sylvestre Ledru [:Sylvestre]]

Comment on attachment 8555477 [details] [diff] [review]
alpha-read.diff (37 and older)

Clearing the uplift flags as we are working on the 36 release now.