Created attachment 149357 [details] Plasma blur + window opacity scroll SUMMARY Not sure if Meta+Scroll is the default, but it is set up to change window opacity on my system. It is probably not a mainstream and quite a corner case feature, except… more on that later. This opacity does not play well with the blur effect behind windows. The way the blur implemented is that it is an additional layer behind the window blending layer. So when the window's opacity is reduced to zero, the blur behind it comes forward as a light e.g. blue color, much lighter than the background which it blurs. The window opacity may be changed by other means, of course, one of which is to have it always on (like was doing few years ago, so I could always peek behind any currently front window), another is to animate window opacity e.g. on show and hide. STEPS TO REPRODUCE 1. Enable the Blur and Background contrast effects. 2. Reduce windows opacity down or close to zero. OBSERVED RESULT Light blurred background instead of a truly transparent window. Actually, the "light" part of it is caused by the "Background contrast" effect. EXPECTED RESULT Blur, contrast and the window content should change transparency all together at once. SOFTWARE/OS VERSIONS Operating System: Arch Linux KDE Plasma Version: 5.25.80 KDE Frameworks Version: 5.95.0 Qt Version: 5.15.4 Kernel Version: 5.18.0-arch1-1 (64-bit) Graphics Platform: X11 Processors: 8 × Intel® Core™ i7-6700HQ CPU @ 2.60GHz Memory: 15.6 GiB of RAM Graphics Processor: NVIDIA GeForce GTX 970M/PCIe/SSE2 ADDITIONAL INFORMATION Also, Meta+Scroll is being passed down to whatever is under the cursor as just scrolling events, causing all sorts of incidents like the keyboard layouts switching, volume & brightness changing and random accidental page scrolling. But that's a totally different issue to handle.
I notice this every time a Plasma tooltip, notification, or OSD fades in and out, especially against dark backgrounds. I can also reproduce this with both windows and Plasma panels exactly as on the video attached to the description. But unlike the reporter, I use AMD instead of Nvidia for the GPU. Operating System: Manjaro Linux KDE Plasma Version: 5.26.5 KDE Frameworks Version: 5.102.0 Qt Version: 5.15.8 Kernel Version: 6.1.8-1-MANJARO (64-bit) Graphics Platform: X11 Graphics Processor: AMD Radeon RX 570 Series Graphics Driver: Mesa 22.3.4
The blur effect doesn't change colors, but the contrast effect does
Why don't they both reduce the opacity in sync with the window? Any technical reasons against that?
The blur effect does it, the contrast one does not. I can't think of a reason why it would have to be this way though