Bug 431523

Summary: Window shadows don't scale with HiDPI
Product: [Plasma] Breeze Reporter: Janet Blackquill <uhhadd>
Component: window decorationAssignee: Janet Blackquill <uhhadd>
Status: ASSIGNED ---    
Severity: normal CC: kwin-bugs-null
Priority: NOR    
Version First Reported In: unspecified   
Target Milestone: ---   
Platform: Other   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description Janet Blackquill 2021-01-12 22:13:55 UTC
Self explanatory. Window shadows don't scale with HiDPI.
Comment 1 Vlad Zahorodnii 2021-01-14 11:53:45 UTC
On a HiDPI setup, decoration shadows will be upscaled using the linear filter. I wonder if there are noticeable differences between hidpi shadows and upscaled shadows.
Comment 2 Janet Blackquill 2021-01-25 20:52:08 UTC
> On a HiDPI setup, decoration shadows will be upscaled using the linear filter. 

This doesn't seem to be the case. What actually seems to happen is that the shadow is rendered into a buffer at 2x (or whatever the scale factor is) size, but due to missing scale factor information from KWin on X11, the shadow is essentially rendered as a 1x scale shadow on a window of double geometry size.