1383494 - Flash objects have screen tearing on Hi-DPI displays if wmode is either "transparent" or "opaque"

Status: RESOLVED WONTFIX

(Core Graveyard :: Plug-ins, defect, P3)

Description

[doomtay]

Attachment: brokenflash.png

User Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:54.0) Gecko/20100101 Firefox/54.0
Build ID: 20170628075643

Steps to reproduce:

Open up Firefox on a Hi-DPI Monitor
Visit a page with a Flash object, such as http://www.konami.jp/gs/game/mpo+/en/top.html
Mouse over character options


Actual results:

The "currently selected option" bar and other parts of the menu are only partially updated.


Expected results:

Flash rendering should be updated in full

Curiously, this bug only manifests when viewing the SWF from the web page. Viewing the SWF directly (http://www.konami.jp/gs/game/mpo+/en/mpo.swf) works just fine.

Comment 1

[doomtay]

Screen tearing also occurs with Nicoviewer's flash player (i.e. http://nviewer.mobi/player?video_id=sm31457372) and http://melusine.eu.org/syracuse/swf/1-mandel/ but not places like Newgrounds or Kongregate

Comment 2

[doomtay]

Attachment: lagtest.html

Culprit seems to be wmode being set to either "opaque" or "transparent"

Comment 3

[Benjamin Smedberg]

I can't reproduce this in nightly (didn't try 54). But if it's true it's something we should look into, since we're moving all plugins to windowless. NI?qdot because of his history with bug 820831

Comment 4

[Benjamin Smedberg]

Oh! I can reproduce this with async drawing *off*, but not on.

Which means this can still affect win32 release where we have async off, but won't affect win64 by default any more. Jim, do you have a roadmap/plan for turning async drawing on for win32?

Comment 5

[Jim Mathies [:jimm]]

(In reply to Benjamin Smedberg [:bsmedberg] from comment #4)
> Oh! I can reproduce this with async drawing *off*, but not on.
> 
> Which means this can still affect win32 release where we have async off, but
> won't affect win64 by default any more. Jim, do you have a roadmap/plan for
> turning async drawing on for win32?

Yes, rolling out in 55, 54 has 64-bit enabled.


(In reply to doomtay from comment #2)
> Created attachment 8889706 [details]
> lagtest.html
> 
> Culprit seems to be wmode being set to either "opaque" or "transparent"

https://wiki.mozilla.org/Plugins/Async_Drawing#Current_WMODE_Handling

For opaque you'll get async non-acclerated painting, and for transparent you'll get the slowest path we have, sync non-acclerated painting. It's better to leave wmode undefined, or choose direct if you can.

Comment 6

[doomtay]

Thanks for the advice. Sadly, this is concerning third-party websites which I have no control over.

Comment 7

[Jim Mathies [:jimm]]

Still seeing this in the latest release (56)?

Comment 8

[doomtay]

There is no more screen tearing as of v56 for all six wmode settings

Comment 9

[alex_mayorga]

https://www.adobe.com/products/flashplayer/end-of-life.html