Le 16/05/2019 à 21:41, Helge Hafting a écrit :
Your patch fixed the problem! Without the patch: 2.3.3dev runs on wayland, but often displays the background image instead of plain text. With this patch: 2.3.3dev on wayland seems to work perfectly. I can scroll through the user guide at high speed. And I have not seen any glitches where the background shows instead of text.
Do you obtain proper sub pixel aliasing if the desktop is configured to use that? We did not have that in X11 when using a pixmap buffer.
To me, it does not look like "missing drawing", but "wrong drawing". With "missing drawing", I'd expect old content to stay while only some lines get updated. Instead, lines that were fine is suddenly overpainted with my background image. Or maybe qt5 explicitly paints the background on anything that isn't updated properly?
We tell Qt "do not clear anything for us, we draw what is needed". On X11 and Windows, this works well. On macOS, Qt decides that it should paint the window in black. And in Wayland, it seems that is copies the background. The problem is that the behavior of this setting is not really documented.
Anyway, I'll make it work for Wayland, but not for 2.3.3. It might even be for 2.4.0 only.
In the long term, I shall re-implement what has been proposed by Patrick De Visschere around here:
https://marc.info/?t=150567072900001&r=1&w=2 I have done work since then that makes it a bit easier.
Anyway, the patch solved the problem. Is a bug report still necessary?
No that's OK. Thanks for confirming. JMarc
