Bug 453900

Summary: QtQuick Label items exhibit graphical glitches when Plasma is run in a VM
Product: [Frameworks and Libraries] frameworks-qqc2-desktop-style Reporter: roxfr
Component: generalAssignee: Marco Martin <notmart>
Status: REPORTED ---    
Severity: normal CC: ahiemstra, hubn3rd, kde, nate, noahadvs
Priority: NOR    
Version First Reported In: 5.94.0   
Target Milestone: ---   
Platform: Arch Linux   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:
Attachments: Bug displaying header text
Font
Konsole+Kinfocenter
Manjaro_KDE_21.2.6_01
Manjaro_KDE_21.2.6_02
Glitch_systemsettings_Kinfocenter_Manjaro_KDE_Wayland_5.24.5
Good image with Wayland
Virtualbox graphics acceleration
QTQuick_with_Material_kinfocenter_OK
QTQuick_with_Universal_kinfocenter_OK

Description roxfr 2022-05-16 18:17:02 UTC
Created attachment 148888 [details]
Bug displaying header text

Hello,

I have a bug displaying header text in Info Center via systemsettings.

More info below:

VirtualBox 6.1.34r150636 (Qt5.6.2)
Operating System: EndeavourOS
KDE Plasma version: 5.24.5
KDE Frameworks Version: 5.94.0
Qt version: 5.15.4
Kernel version: 5.17.7-arch1-1 (64-bit)
Graphics Platform: X11
Processors: 6 × AMD Ryzen 5 3600 6-Core Processor
Memory: 7.8 GiB RAM
GPU: SVGA3D; build: RELEASE; LLVM;

Regards,
Roxfr
Comment 1 Nate Graham 2022-05-16 19:17:10 UTC
That's strange. I have a few questions:

1. What font and font size are you using?
2. Does this issue happen for any header text in Discover, or on any System Settings pages?
3. Does the issue happen if you open Info Center directly, rather than from System Settings?
Comment 2 roxfr 2022-05-16 20:26:20 UTC
1. What font and font size are you using?
=> See the first photo attached.

2. Does this issue happen for any header text in Discover, or on any System Settings pages?
=> Not only for the Info Center.

3. Does the issue happen if you open Info Center directly, rather than from System Settings?
=> See the second photo attached.

Regards,
Roxfr
Comment 3 roxfr 2022-05-16 20:27:11 UTC
Created attachment 148897 [details]
Font

Font
Comment 4 roxfr 2022-05-16 20:27:35 UTC
Created attachment 148898 [details]
Konsole+Kinfocenter

Konsole+Kinfocenter
Comment 5 Nate Graham 2022-05-17 14:28:31 UTC
Thanks. Some more questions:
1. Does this issue happen for any header text in Discover?
2. Does it still happen if you use the Breeze Application Style, instead of whatever you're currently using (Looks like Lightly or Kvantum)?
Comment 6 roxfr 2022-05-17 17:21:37 UTC
Hello,
I tested with another distro KDE in virtualbox.
I have the same problem with the police but elsewhere.
Maybe it comes from virtualbox?
It would be necessary to have a return with a KDE linux installed hard on the machine.
Regards,
Roxfr

PS: See attached images.
Comment 7 roxfr 2022-05-17 17:22:29 UTC
Created attachment 148922 [details]
Manjaro_KDE_21.2.6_01

Manjaro_KDE_21.2.6_01
Comment 8 roxfr 2022-05-17 17:22:45 UTC
Created attachment 148923 [details]
Manjaro_KDE_21.2.6_02

Manjaro_KDE_21.2.6_02
Comment 9 Nate Graham 2022-05-17 21:01:23 UTC
OK, so you're seeing bizarre text glitches in Label items everywhere.

Seems like a GPU rendering incompatibility. Can you try using the Plasma Wayland session in your VM and seeing if the glitches disappear, or if they still manifest?
Comment 10 roxfr 2022-05-18 16:47:30 UTC
I updated the distro and switched to the Wayland display server.
The bug (glitch) is still present.
Regards,
Roxfr

PS : See image attached.
Comment 11 roxfr 2022-05-18 16:48:41 UTC
Created attachment 148964 [details]
Glitch_systemsettings_Kinfocenter_Manjaro_KDE_Wayland_5.24.5

Glitch_systemsettings_Kinfocenter_Manjaro_KDE_Wayland_5.24.5
Comment 12 roxfr 2022-05-18 16:51:35 UTC
Created attachment 148965 [details]
Good image with Wayland

Good image with Wayland
Comment 13 roxfr 2022-05-18 16:57:17 UTC
Okay that's good !
You can close the topic.
It comes from virtualbox when you check graphics acceleration.
Regards,
Roxfr

PS: See image attached.
Comment 14 roxfr 2022-05-18 16:58:14 UTC
Created attachment 148966 [details]
Virtualbox graphics acceleration

Virtualbox graphics acceleration
Comment 15 Nate Graham 2022-05-18 17:06:42 UTC
> It comes from virtualbox when you check graphics acceleration.

Thanks for finding the triggering condition! It sounds like there is an issue with QtQuick itself or our styling of it with certain graphical settings. Can you reproduce the bug when you turn on graphics acceleration in Virtualbox and launch Info Center with the Universal or Material styles? You can try that out like so:

`QT_QUICK_CONTROLS_STYLE=Universal kinfocenter`

`QT_QUICK_CONTROLS_STYLE=Material kinfocenter`

That'll tell us if the issue is in our styling, or in Qt itself.
Comment 16 roxfr 2022-05-18 18:14:49 UTC
Ok, no more problem using either of the two commands.
See attached images.
Comment 17 roxfr 2022-05-18 18:15:27 UTC
Created attachment 148971 [details]
QTQuick_with_Material_kinfocenter_OK

QTQuick_with_Material_kinfocenter_OK
Comment 18 roxfr 2022-05-18 18:15:45 UTC
Created attachment 148972 [details]
QTQuick_with_Universal_kinfocenter_OK

QTQuick_with_Universal_kinfocenter_OK
Comment 19 Nate Graham 2022-05-18 18:41:58 UTC
Thank you very much. So this seems like a problem in our style. Moving to qqc2-desktop-style.