Bug 311698 - Windows Blur Upon Desktop Switching On nVidia Video Chip With FXAA Enabled
Summary: Windows Blur Upon Desktop Switching On nVidia Video Chip With FXAA Enabled
Status: RESOLVED DUPLICATE of bug 307003
Alias: None
Product: kwin
Classification: Plasma
Component: effects-window-management (show other bugs)
Version: 4.9.3
Platform: Ubuntu Linux
: NOR normal
Target Milestone: ---
Assignee: KWin default assignee
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2012-12-14 16:05 UTC by Mikiya Okuno
Modified: 2012-12-15 00:57 UTC (History)
0 users

See Also:
Latest Commit:
Version Fixed In:
Sentry Crash Report:


Attachments
Texts blur (436.79 KB, image/png)
2012-12-14 16:06 UTC, Mikiya Okuno
Details
Texts don't blur without FXAA (394.22 KB, image/png)
2012-12-14 16:09 UTC, Mikiya Okuno
Details

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Description Mikiya Okuno 2012-12-14 16:05:16 UTC
When FXAA feature is enabled on nVidia video chip with proprietary driver, contents of windows blur after desktop switching. The problem can be solved by refreshing (repainting) windows by doing any actions (e.g. select/deselect texts in it).

Reproducible: Always

Steps to Reproduce:
1. Enable FXAA on nvidia-settings
2. Turn "Keep window thumbnails" to "Never"
3. Turn "Keep window thumbnails" to "Only for Shown Windows"
4. Switch desktop
Actual Results:  
Window contents blur

Expected Results:  
Window contents are shown as is
Comment 1 Mikiya Okuno 2012-12-14 16:06:24 UTC
Created attachment 75831 [details]
Texts blur
Comment 2 Mikiya Okuno 2012-12-14 16:09:17 UTC
Created attachment 75832 [details]
Texts don't blur without FXAA
Comment 3 Thomas Lübking 2012-12-14 16:28:35 UTC
That's not a bug - you're keeping a full screen antialiaser active and it does exactly what it's supposed to do (everytime glXSwapBuffer is invoked)

It also has a performance impact, so you basically don't want to use it with a WM at all (notably not, since well'll likely have to swap buffers for effective vsyncing)

So far there's unfortunately not env to control that behavior in the driver (so we cannot toggle off FXAA for you)

*** This bug has been marked as a duplicate of bug 307003 ***
Comment 4 Mikiya Okuno 2012-12-15 00:45:45 UTC
Thomas,

Thank you for your comment. My question is why such blur goes away after repaint. If KWin cannot turn FXAA off, it should always ON even after repainting, shouldn't it? Are foreground window painted in 2D (non-OpenGL fashon)?
Comment 5 Martin Flöser 2012-12-15 00:57:56 UTC
> Thank you for your comment. My question is why such blur goes away after
> repaint. If KWin cannot turn FXAA off, it should always ON even after
> repainting, shouldn't it? Are foreground window painted in 2D (non-OpenGL
> fashon)?
Buffer swapping is only performed during fullscreen effects. For normal 
operations only the relevant areas are copied. KWin cannot know that FXAA is 
turned on and therefore cannot react to it.