Screen flickers in webclient

ID:2062250
 
Mar 31 2016, 1:45 am
BYOND Version:510.1335
Operating System:Windows 7 Pro 64-bit
Web Browser:Chrome 49.0.2623.110
Applies to:Webclient
Status: Unverified
Thus far we've been unable to verify or reproduce this bug. Or, it has been observed but it cannot be triggered with a reliable test case. You can help us out by editing your report or adding a comment with more information.
Descriptive Problem Summary:
The map flickers with a black screen extremely fast.



Numbered Steps to Reproduce Problem:
Nothing special was required to do.

Code Snippet (if applicable) to Reproduce Problem:
I tested 3 different projects one of which had just this:
mob
    icon = '1.dmi'
    icon_state = "1"

turf
    icon = '1.dmi'
    icon_state = "2"


Scratch project link: https://dl.dropboxusercontent.com/u/51176364/scratch.zip

Expected Results:
No flickers.

Actual Results:
Flickers.

Does the problem occur:
Every time? Or how often? Yes
In other games? Yes
In other user accounts? Yes
On other computers? Yes

When does the problem NOT occur?
No idea, it actually also occurs in stable build

Did the problem NOT occur in any earlier versions? If so, what was the last version that worked? (Visit http://www.byond.com/download/build to download old versions for testing.)
It occurs in latest stable build but the flickers there look different.

Workarounds:

Mar 31 2016, 5:41 am
O.o tf
Mar 31 2016, 12:50 pm
Lummox JR changed status to 'Unverified'
Mar 31 2016, 12:54 pm
I tried to replicate this with your test project (thanks for providing that), but unfortunately I could not.

In your JavaScript console, does the output show any information about the rendering mode being used? The Canvas2D mode has a lot of limitations (it currently can't handle atom.color/alpha at all) and it's a bit slower; about 20% slower when looking at Chrome's FPS monitor. Also I'm curious what your monitor's refresh rate is.

The webclient.dart.js code says that requestAnimationFrame() is being used, which should be syncing drawing to the vertical sync of your monitor.
Apr 1 2016, 12:16 am
In response to Lummox JR
The flickering happens for me.
See: https://dl.dropboxusercontent.com/u/25338425/ www.byond.com-1459491317975.log


Chrome 50.0.2661.57 beta-m (64-bit)
Apr 1 2016, 2:15 am (Edited on Apr 1 2016, 2:53 am)
It didn't happen in Canvas2D but did happen with the other 2.

EDIT: https://dl.dropboxusercontent.com/u/51176364/ www.byond.com-1459500164050.log

EDIT 2: My monitor's refresh rate is 144hz but I don't think Murra's monitor is as well.
Apr 1 2016, 9:40 am
The WebGL errors are meaningless; they appear early on in the process when the display hasn't been full setup yet. I've been wanting to purge those but they happen fairly deep in StageXL code, so I'm not sure what I need to do to get rid of them.

Murrawhip, the script error you got about a parenthesis was more distressing. Based on the errors I saw about unfilled atoms, I assume that's a different project. Any custom JS in there that might be relevant?
Apr 1 2016, 2:25 pm
I just tried in IE (win7) and the flickers don't occur there.

Would the graphic card matter? I'm using an AMD card and I think so does Murrawhip.
Apr 1 2016, 2:43 pm
Possibly, but unlikely.
Apr 2 2016, 2:55 pm
In response to Lummox JR
Lummox JR wrote:
Murrawhip, the script error you got about a parenthesis was more distressing. Based on the errors I saw about unfilled atoms, I assume that's a different project. Any custom JS in there that might be relevant?

Yeah sorry, I was running a different project.
This time I ran the scratch, compiled+hosted with 510.1336, hosted locally.

Log file: https://dl.dropboxusercontent.com/u/25338425/ www.byond.com-1459630353028.log

The flickering isn't as often as in the OP gif, but still pretty evident. It seems to get way more flickery for a couple seconds when I switch off the tab then come back to it.

Doesn't happen in firefox.
I'll try to narrow down which version it was introduced in when I have some time next week.
Apr 13 2016, 1:33 am
I've added lighting planes example in and got this new error, I'm not sure whether it's related or not.

https://dl.dropboxusercontent.com/u/51176364/ www.byond.com-1460530130786.log

Apr 13 2016, 3:09 am
https://dl.dropboxusercontent.com/u/63471110/ScreenBug.rar

It's not only in webclient. Also happens in dreamseeker.

And Lummox ofcourse you can't reproduce it thats because you need a resolution bigger equal to 1920x1080p or higher otherwise the bug doesn't happen.
Apr 13 2016, 5:19 am
I just tried to lower my resolution and it still occurs, just webclient, never in dreamseeker.

Do you have a demo that shows flickers in dreamseeker? That will help immensely.
Apr 13 2016, 5:57 am
I don't but its easy to setup, make a map that has X:100,Y=15 or something and Edge perspective aswell, and try to Scale it, also maximize the window and then go to the edges the flicker will occure until you exit those Edges.
Apr 13 2016, 7:46 am
I've followed your instructions and updated my demo with them, however, I do not experience any flickers.

In your video it looks like the perspective is rapidly changing resulting in what appears as flickers but it's actually just your view shifting back and forth, I'm sure that if you passed frame by frame this would be more noticeable, although I haven't checked.

For me, the flickers are not dependent on map edges, they're black frames inserted over the map.

I don't think our issues are related, you could however, take my demo and change it so it reproduces your problem and create a separate bug report for it.

I find that empty projects are best route to isolate the cause, it also makes it insanely easier to debug.


Apr 13 2016, 9:33 am
Huh. The lighting plane error you got is definitely wrong, so I'll look into that.