https://bugs.kde.org/show_bug.cgi?id=389329
Bug ID: 389329
Summary: 4k HiDPI wayland 2x display scaling issues
Product: plasmashell
Version: 5.11.95
Platform: Gentoo Packages
OS: Linux
Status: UNCONFIRMED
Severity: normal
Priority: NOR
Component: generic-wayland
Assignee: plasma-b...@kde.org
Reporter: bug2...@wolke7.net
Target Milestone: 1.0
I'm running the plasma-5.12 branch from the kde overlay (with qt 5.10). My
Notebook has an 15.6" 4k screen. And on wayland I run into the fallout of the
new scaling feature:
http://blog.davidedmundson.co.uk/blog/kwin_and_scaling/
Some of the issues:
1) Many applications which respect the screens resolution and scale well, are
rendered with half resolution. It looks worse than a 1080p screen, where it is
possible to enable sub pixel rendering for fonts.
2) The mouse pointer size changes depending on the window type, it shrinks to
the half size above scaled up applications.
3) Kicker: The Application menu has much higher spacing between the items.
4) Tiling is ok for scaled up applications (like dia, chrome ...) But
completely messed up for application which run on the native resolution (like
kwrite):
Top Left corner: Almost maximized in top left
Left: Similar layout
Bottom Left: Similar size, but half of the window below the screen
Bottom right: Only the upper left quarter is visible (centered on bottom
right corner)
Right: Only left half is visible
Top right: Similar to Right
For me it looks like these tiled applications windows are twice as large as
they should be.
5) Full screen applications/games like sauerbraten: Not usable at all. Only the
upper left quarter scaled by 2.
In window mode the mouse is not passed through. Without the ability to aim, it
is quite unfair (maybe unrelated)
I suggest to set the default scaling for the upcoming plasma-5.12 back to 1x
While writing this bug report I have switched it back to 1x scaling and set the
font DPI to 192. This setup give a much better 4k support. Some old legacy
application don't scale correctly (like dia or imagej), but it would be much
better to have fixes per window or application, than breaking the whole
desktop.
In future it might be a good idea to not assume that a screen has 96DPI. It
would be much better to respect the values from the EDID. In case of notebook
screen a correction might be a good idea, as they are typically a little closer
than regular screens.
The DPI override should move from the font configuration to each display. Maybe
the display with the the highest DPI can be used as rendering resolutions.
For other lower resolution display it would be better to downscale. But in that
case even sub pixel rendering can help, to preserve as much information as
possible.
So instead using a 2x scale, we need a 0.5x scale for peasant displays (or 0.33
for cloning too a 720p projector)
For legacy applications it would be nice to have an 2x scaling (which also
fakes a 96dpi pixel size) Nice to have in the compositor would be an optional
pixel art scaling algorithm like hq2x or 2xsai.
I think things like QT_SCALE_FACTOR should be only used for mitigation of
legacy applications. Try to force a 2x scaling onto other applications will
bring us crappy scaling for the next 5 years. After that it repeats with 8k
notebook screens.
--
You are receiving this mail because:
You are watching all bug changes.
