Bug 466738

Summary:	wayland: 2 monitor setup with 175%/100% scaling: gwenview scales images having the same pixel size as the screen
Product:	[Applications] gwenview	Reporter:	slartibart70
Component:	general	Assignee:	Gwenview Bugs <gwenview-bugs-null>
Status:	RESOLVED DUPLICATE
Severity:	normal	CC:	kde, nate, plasma-bugs
Priority:	NOR
Version:	22.12.2
Target Milestone:	---
Platform:	Fedora RPMs
OS:	Linux
Latest Commit:		Version Fixed In:
Sentry Crash Report:

Description slartibart70 2023-03-02 20:59:32 UTC

+++ This bug was initially created as a clone of Bug #466736 +++

Operating System: Fedora Linux 37
KDE Plasma Version: 5.27.2
KDE Frameworks Version: 5.103.0
Qt Version: 5.15.8
Kernel Version: 6.1.14-200.fc37.x86_64 (64-bit)
Graphics Platform: Wayland
Processors: 8 × Intel® Core™ i7-7820HQ CPU @ 2.90GHz
Memory: 31,1 GiB of RAM
Graphics Processor: Mesa Intel® HD Graphics 630

Setup:
Laptop with 2K Laptop screen and a fullhd screen (1920x1080) connected by displayPort
Use fullHD monitor as 'primary' and perform all tests on the fullHD monitor (ignore laptop screen)

Go to systemsettings > display config
and set 175% scale for 2K laptop screen, 100% for fullhd screen.
This makes apps/windows on both monitors the same visual size.

Problem:

Open an image folder (e.g.  /usr/share/wallpapers/Next/contents/images/) and select the 1920x1080 image size picture. Right click on the file and select/open gwenview on the full-hd screen

The image is shown, but scaled - even if you set gwenview to 100% or full-screen.
As the monitor has 1920x1080 pixels and the image shown has the same pixel size, i would expect it to be filling/covering  the whole screen, but gwenview (maximized) only renders a smaller version of it.

Comment 1 Nate Graham 2023-03-06 17:44:37 UTC

What do you mean scaled? Can you attach a screenshot that shows the issue?

Comment 2 slartibart70 2023-03-06 22:27:33 UTC

Sorry for the bad video quality...

1) Both monitors are setup to 100%
https://www.dropbox.com/s/npy9i4xamdcddyl/VID_20230306_222847.mp4?dl=0

The fullHD monitor displays the 1920x1080 image as 'fit' but i can zoom to 100% - and the image covers the screen (see also the zoom-box in lower right corner)

2) Now, fullHD is 100%, 2k monitor is 175%
https://www.dropbox.com/s/9vovux9aqpesi53/VID_20230306_223108.mp4?dl=0

The 1920x1080 is initially rendered as 'fit' and way smaller (scaled/zoomed) as in the 100/100% scenario.
Setting zoom to 100% still does not make the image cover the whole screen, it's still smaller although it should be pixel-perfect sized to the screen dimensions

Here you can also see the problem with the browse button (https://bugs.kde.org/show_bug.cgi?id=466739) and the messed up folder-view when moving the mouse

Comment 3 Nate Graham 2023-03-07 15:35:49 UTC

Ah I see, it's ultimately caused by the same issue causing Bug 465688.

*** This bug has been marked as a duplicate of bug 465688 ***