| Summary: | QtQuick Icon Fringing on QD-OLED Displays | ||
|---|---|---|---|
| Product: | [Applications] systemsettings | Reporter: | Madhu <destiny> |
| Component: | kcm_icons | Assignee: | Plasma Bugs List <plasma-bugs-null> |
| Status: | REPORTED --- | ||
| Severity: | normal | ||
| Priority: | NOR | ||
| Version First Reported In: | unspecified | ||
| Target Milestone: | --- | ||
| Platform: | Arch Linux | ||
| OS: | Linux | ||
| Latest Commit: | Version Fixed/Implemented In: | ||
| Sentry Crash Report: | |||
| Attachments: | Red Trash/Delete icon fringing on right edge and tickers on slider in both white and blue | ||
Forgot to mention, this also impacts fonts on red backgrounds |
Created attachment 186833 [details] Red Trash/Delete icon fringing on right edge and tickers on slider in both white and blue ## Summary Red icons in System Settings show rainbow color fringing on QD-OLED displays with mixed-DPI multi-monitor setup ## Environment - Primary monitor: QD-OLED @ 100% scaling - Secondary monitor: 4K @ 125% scaling - Qt version: 6.10.0 - Session: Wayland ## Steps to Reproduce 1. Use a QD-OLED monitor at 100% scaling + a second monitor at 125% scaling 2. Open System Settings on the QD-OLED monitor 3. Navigate to Appearance → Icons 4. Look at the red trash icon next to installed icon packs ## Expected Result Icons should render cleanly without color artifacts ## Actual Result The red trash icon shows rainbow color fringing on one edge. The fringing changes position when the window is moved. This doesn't happen with white/gray icons, only red ones. ## Additional Details QD-OLED displays use a different subpixel layout than regular LCD monitors (triangular pattern instead of RGB stripe). I think the issue is related to how icons are cached at different DPI scales and then displayed - fractional pixel positioning causes the color channels to misalign on the triangular subpixel layout. White icons don't show this problem because all color channels are active. Red icons make the misalignment obvious. I tested several environment variables to work around it but nothing helped: - QSG_ANTIALIASING_METHOD=none - QT_QUICK_BACKEND=software - Various other QtQuick rendering options Note: Text rendering has a similar issue but is fixed with `QT_SUBPIXEL_AA_TYPE=""`. That doesn't help with icons though. The issue only affects QtQuick applications like System Settings. QWidget apps like Dolphin don't have this problem.