Bug 438514

Summary: "Invert Screen Colours" results in wrongly rendered text and different behaviour from "Toggle invert effect"
Product: [Plasma] kwin Reporter: Angelos Skembris <a.skembris>
Component: compositingAssignee: KWin default assignee <kwin-bugs-null>
Status: RESOLVED UNMAINTAINED    
Severity: normal CC: nate
Priority: NOR    
Version First Reported In: 5.21.5   
Target Milestone: ---   
Platform: openSUSE   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:
Attachments: Font rendered incorrectly when the "Invert Screen Colours" option is chosen.

Description Angelos Skembris 2021-06-12 17:26:24 UTC
Created attachment 139261 [details]
Font rendered incorrectly when the "Invert Screen Colours" option is chosen.

SUMMARY

When searching the keyboard shortcuts options with the keyword "invert", two options come up:

1) "Invert Screen Colours"
2) "Toggle invert Effect"

Option #2 works as expected.

Option #1 results in text font rendered poorly, with only the edges of the fonts being rendered (example photo of effect attached). 

This seems to happen in some applications like LibreOffice and Word (with CrossOver) but not others (e.g. Vivaldi's text is rendered normally under inverted colours no matter what the size.   

This is with X11. 

I suggest that having two methods / options of doing this is confusing; this option should be toggled through one avenue only (and work as expected). 


STEPS TO REPRODUCE
1. Open "Settings -> Shortcuts" and search using the keyword "invert"
2. Define a shortcut for "Invert Screen Colours" if not already defined) and use it to invert the screen colours
3. Open LibreOffice, write something and zoom in so that the text appears very large.  

OBSERVED RESULT

Only the text edges are rendered 

EXPECTED RESULT

The text colour should be the exact inversion of the original one.  

SOFTWARE/OS VERSIONS
Windows: 
macOS: 
Linux/KDE Plasma: 
(available in About System)
KDE Plasma Version: 5.21.5
KDE Frameworks Version: 5.82.0
Qt Version: 5.15.2

ADDITIONAL INFORMATION
Comment 1 Nate Graham 2021-06-17 15:49:00 UTC
For me, both of them works perfectly without the font issue you're reporting. Regardless, it's extremely odd to have two color inversion effects in KWin. :) We should probably remove either the built-in one, or else the desktop effect version.
Comment 2 Angelos Skembris 2021-06-19 16:28:12 UTC
Thanks for looking into this, Nate. 

Upon some further investigation, I noticed that the problem only occurs in X11 sessions of Plasma. The Plasma (Wayland) session seems to invert colours as expected. Could it be graphics driver-related? I am running this on an iGPU (Ryzen 4600h with Renoir graphics).

Also, the "Invert Effect on Window" option works as expected in both cases. This is a great feature by the way, kudos to whoever came up with it, I don't have to invert the whole screen any more! Yay!
Comment 3 David Edmundson 2023-09-06 10:38:12 UTC
This bug was reported against an outdated version of KWin. We have made many changes since the. 
If the issue persists in newer versions can you reopen the bug report updating the version number.