SUMMARY When using the touchscreen to pan and rotate the viewport of the document when the viewport is panned horizontally offset from the center, the document would unexpectedly jitter and pan vertically. STEPS TO REPRODUCE 1. Make a new document with pixel dimensions of at least 16000x8000. Make some lines or a grid to make sure you have a reference. 2. Pan the document to either the very left or the very right side of the screen. 3. Rotate the canvas side to side from zero degrees using the touch screen controls. This is done using two fingers and pivoting them around like a valve or a wheel. OBSERVED RESULT The document would pan up or down on its own even if the fingers are not attempting to pan up or down. The effect becomes more extreme when zoomed in and further away horizontally from the center. EXPECTED RESULT The canvas would rotate properly without feeling as if was slipping out of your control. SOFTWARE/OS VERSIONS Windows: Windows 10 Qt Version: 5.12.9 ADDITIONAL INFORMATION Krita window is fullscreen at a resolution of 3840x2160. DPI is 150%.
A possibly relevant merge request was started @ https://invent.kde.org/graphics/krita/-/merge_requests/833
Git commit 50d1637803accbab2c7ac6ad05c84a2cf8fe8b2f by Dmitry Kazakov, on behalf of Sharaf Zaman. Committed on 06/05/2021 at 04:25. Pushed by dkazakov into branch 'master'. Bugfix: Unstable canvas when touch rotation is enabled M +67 -16 libs/ui/input/kis_zoom_and_rotate_action.cpp M +3 -2 libs/ui/input/kis_zoom_and_rotate_action.h https://invent.kde.org/graphics/krita/commit/50d1637803accbab2c7ac6ad05c84a2cf8fe8b2f