Bug 477841

Summary: Magnifier effect does not work when an icc color profile is used
Product: [Plasma] kwin Reporter: Patrick Silva <bugseforuns>
Component: effects-variousAssignee: KWin default assignee <kwin-bugs-null>
Status: RESOLVED FIXED    
Severity: normal CC: nate
Priority: NOR Keywords: qt6, wayland
Version: 5.90.0   
Target Milestone: ---   
Platform: Arch Linux   
OS: Linux   
See Also: https://bugs.kde.org/show_bug.cgi?id=477017
Latest Commit: https://invent.kde.org/plasma/kwin/-/commit/ab48621758364b6ed245400821ef4368d3f78433 Version Fixed In:
Sentry Crash Report:

Description Patrick Silva 2023-12-01 15:16:59 UTC 
STEPS TO REPRODUCE
1.  enable Magnifier effect in Desktop Effects KCM
2. press meta+(+)
3. 

OBSERVED RESULT
black square near the mouse pointer

EXPECTED RESULT
Magnifier effect  works

SOFTWARE/OS VERSIONS
Operating System: Arch Linux 
KDE Plasma Version: 5.90.0
KDE Frameworks Version: 5.246.0
Qt Version: 6.6.1
Graphics Platform: Wayland
Comment 1 Nate Graham 2023-12-01 18:47:10 UTC 
Works for me with an Intel iGPU (10th gen). This seems like it could be a GPU driver issue. What GPU are you using? Are you in a VM?
Comment 2 Patrick Silva 2023-12-01 19:00:04 UTC 
My Plasma is installed on a physical machine with intel iGPU.

Processors: 4 × Intel® Core™ i5-4670K CPU @ 3.40GHz
Graphics Processor: Mesa Intel® HD Graphics 4600
Comment 3 Patrick Silva 2023-12-02 10:27:09 UTC 
Found the culprit: icc color profile.

STEPS TO REPRODUCE
1. apply an icc color profile in Display Configuration KCM
2.  enable Magnifier effect in Desktop Effects KCM
3. press meta+(+)
Comment 4 Bug Janitor Service 2023-12-05 11:19:03 UTC 
A possibly relevant merge request was started @ https://invent.kde.org/plasma/kwin/-/merge_requests/4744
Comment 5 Zamundaaa 2023-12-05 18:05:54 UTC 
Git commit ab48621758364b6ed245400821ef4368d3f78433 by Xaver Hugl.
Committed on 05/12/2023 at 18:56.
Pushed by zamundaaa into branch 'master'.

plugins/magnifier: use floating point offscreen texture

With color management, everything would get clamped to 1 nit otherwise.

M  +2    -2    src/plugins/magnifier/magnifier.cpp

https://invent.kde.org/plasma/kwin/-/commit/ab48621758364b6ed245400821ef4368d3f78433