https://bugs.kde.org/show_bug.cgi?id=526177
Bug ID: 526177
Summary: Layer previews trail far behind the cursor when moving
or transforming on Ubuntu GNOME Wayland with Intel UHD
620
Classification: Applications
Product: krita
Version First 5.3.4
Reported In:
Platform: Ubuntu
OS: Linux
Status: REPORTED
Severity: normal
Priority: NOR
Component: * Unknown
Assignee: [email protected]
Reporter: [email protected]
Target Milestone: ---
Created attachment 196510
--> https://bugs.kde.org/attachment.cgi?id=196510&action=edit
Krita 5.3.4 system information
SUMMARY
On Ubuntu 26.04 GNOME Wayland, the live canvas preview of a layer falls far
behind the pointer when the layer is dragged. The selection/transform bounding
box can move to the current pointer position while the actual layer content
remains at an older position for a noticeable time. This makes interactive
layer positioning very difficult.
The problem is reproducible in a new 1920 x 1080 document with one simple
opaque shape, so it is not specific to a large or complex document. Canvas FPS
can remain high (commonly around 70–150 FPS) while the visible layer content
still trails the pointer.
STEPS TO REPRODUCE
1. Start the official Krita 5.3.4 Linux AppImage on an Ubuntu 26.04 GNOME
Wayland session.
2. Create a new 1920 x 1080 RGB/Alpha 8-bit document.
3. Add one paint layer and draw or fill a simple opaque rectangle.
4. Select the Move Tool and drag the layer quickly back and forth across the
canvas using a mouse or touchpad.
5. Also press Ctrl+T and drag the free-transform preview.
OBSERVED RESULT
The layer content does not stay near the pointer. It visibly trails the
tool/transform bounding box and may show stale intermediate positions. The
delay is severe enough to make precise interactive placement impractical. The
issue occurs with a mouse, touchpad, and tablet input, so it is not specific to
the tablet.
The issue reproduces every time in:
- Official Krita 5.3.4 AppImage, Qt 5.15.7, XCB/XWayland (the AppImage has no
native Wayland platform plugin).
- Official Krita 6.0.4 AppImage, Qt 6.8.0, native Wayland.
- Ubuntu package Krita 6.0.1, Qt 6.10.2, native Wayland.
EXPECTED RESULT
The live layer content should remain close to the pointer and its bounding box
while dragging, without a large visible backlog of old positions.
SOFTWARE/OS VERSIONS
- OS: Ubuntu 26.04 LTS, kernel 7.0.0-31-generic
- Desktop/session: GNOME Shell 50.1, Mutter 50.1-0ubuntu2.4, Wayland
- CPU: Intel Core i5-8365U (4 cores / 8 threads)
- GPU: Intel UHD Graphics 620 (Whiskey Lake GT2)
- Mesa: 26.0.8-1ubuntu0.3
- OpenGL renderer: Mesa Intel UHD Graphics 620 (WHL GT2), OpenGL 4.6
- RAM: 14 GiB; there was no memory pressure during testing
- Display scaling tested: 100% and 125%, with no meaningful difference
ADDITIONAL INFORMATION
- The same minimal test reproduces with mouse and touchpad input, not only with
the tablet.
- Switching among the available canvas acceleration/rendering modes did not
materially change the lag.
- Setting vblank_mode=0 did not materially change it.
- Disabling canvas surface color-space management fixed a separate low-FPS
case, but did not fix the pointer-to-layer delay.
- Mesa, Mutter, GNOME Shell, and Intel graphics firmware were updated to the
current Ubuntu versions and the system was rebooted; the problem remained.
- GIMP also shows a similar delay when interactively moving a layer on the same
GNOME Wayland session. This may indicate an upstream compositor/graphics-stack
interaction rather than a Krita-only issue, but Krita is consistently affected
in both the Move Tool and transform preview.
- The attached Krita system-information and log files come from the tested
official AppImages.
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