864947 - Dungeon Fury displays a black WebGL canvas, but appears in the app switcher

Status: RESOLVED WONTFIX

(Core :: Graphics: CanvasWebGL, defect, P3)

Description

[Chris Lord [:cwiiis]]

If you go to the given URL and install the playcanvas game/demo 'Dungeon Fury', the game appears to work but the WebGL canvas remains black. When I long-press the home button, after the animation has played, I can see the rendering inside the canvas. Switching back to the app, the canvas remains black. HTML overlaid on the canvas displays correctly, sound works correctly and input works correctly.

I tested this on a Geeksphone Keon - unfortunately, I didn't have the device long enough to debug anything. I've tried this same demo on an Unagi phone before, but it refused to run the app altogether (perhaps due to memory limitations). The same demo works fine on Firefox for Android on all WebGL-capable handsets I've tried (but we do have much higher requirements).

FTR, I have seen the same issue with some of my own WebGL code, and I have seen simpler WebGL demos work correctly. I could probably debug this if I had a device and some pointers about b2g debugging.

Comment 1

[Jason Smith [:jsmith]]

Benoit - Any ideas why we are getting a black WebGL canvas?

Comment 2

[Kelsey Gilbert [:jgilbert]]

There were some pretty big issues with WebGL on trunk after landing the layers refactor. How old is your build?

Comment 3

[Kelsey Gilbert [:jgilbert]]

Oh, can you confirm that other demos on the phone ran correctly?

Comment 4

[Jason Smith [:jsmith]]

Chris - Can you address the questions in comment 2 and comment 3?

Comment 5

[Chris Lord [:cwiiis]]

(In reply to Jason Smith [:jsmith] from comment #4)
> Chris - Can you address the questions in comment 2 and comment 3?

Unfortunately, no, I can't. We have a load of Keons here, but I'm not allowed to have one yet :p

I filed this bug after trying one out for a few minutes that belonged to someone else. I'll update this bug as soon as I have a device to test on.

Comment 6

[Chris Lord [:cwiiis]]

Got a phone. This is running whatever the latest stock Keon image is, I don't know where to get more up-to-date images. It says 'Boot2Gecko 1.0.1.0-prerelease' in the device information.

This demo works correctly: http://chrislord.net/demos/clouds/clouds.html

http://operasoftware.github.io/Odin/mobile/ gives me errors linking shaders

http://www.webglearth.com Loads and doesn't give me any errors, but no Earth appears

http://www.emagix.net/images/portfolio/academic/mscs-project/code_projects/01_sample/02_sample.html works correctly

http://apps.playcanvas.com/dave/tutorials/3d_audio works correctly (and slowly)


I think we can safely say that, within the limits of the hardware, WebGL works. What's odd about this case is that the rendering appears in the app switcher, but not in the app itself.

Comment 7

[Chris Lord [:cwiiis]]

Another note, I have another WebGL demo of mine that exhibits the same issue in the browser (black on the screen, but the thumbnail in the tab chooser shows correct rendering).

It appears to be specific to the Keon, the Peak has no such issue.

Comment 8

[Chris Lord [:cwiiis]]

This doesn't happen anymore in current master.

Comment 9

[u279076]

Is this bug still relevant given the state of B2G?