Bug 423542 - Incorrect window scaling on highdpi monitor
Summary: Incorrect window scaling on highdpi monitor
Status: RESOLVED FIXED
Alias: None
Product: kwin
Classification: Plasma
Component: wayland-generic (show other bugs)
Version: git master
Platform: Other Linux
: NOR normal
Target Milestone: ---
Assignee: KWin default assignee
URL:
Keywords: regression
Depends on:
Blocks:
 
Reported: 2020-06-26 11:57 UTC by Nicolas Fella
Modified: 2020-07-06 16:35 UTC (History)
1 user (show)

See Also:
Latest Commit: https://invent.kde.org/plasma/kwin/-/commit/617650d4405774358118866062ece477401652f2
Version Fixed In: 5.20

Attachments
Falkon screen photo (1.42 MB, image/jpeg)
2020-06-26 12:07 UTC, Nicolas Fella 		Details
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Description Nicolas Fella 2020-06-26 11:57:52 UTC 
I have a 4K monitor with 2x scaling and a FHD monitor with 1x scaling. When I open a window on the 4K monitor the content only fills the top left quarter of the window. Once I resize the window it works as expected. Happens with both Qt apps (tested with Falkon) and GTK apps (tested with Gnome clocks). It does not seem to affect XWayland apps (tested with Firefox).

Bisecting KWin leads to 31ea780d7996dd06d34243aeb92386e5571d821e

Qt is built from 5.15 branch
Comment 1 Nicolas Fella 2020-06-26 12:07:57 UTC 
Created attachment 129693 [details]
Falkon screen photo
Comment 2 Vlad Zahorodnii 2020-07-01 07:28:21 UTC 
If you're still able to reproduce this bug, can you please provide a WAYLAND_DEBUG output? (falkon is rendered just fine on my machine)
Comment 3 Vlad Zahorodnii 2020-07-01 07:30:40 UTC 
I believe that it has something to do with not discarding window quads if the frame geometry didn't change, but the buffer geometry did change.
Comment 4 Nicolas Fella 2020-07-06 16:03:45 UTC 
It seems to be fixed, likely because of https://invent.kde.org/plasma/kwin/-/merge_requests/92