Drawing first element has wrong position in multi monitor with different dpi-scaling

[pstuifzand]

After taking a screenshot the first element I'm drawing starts at the wrong position. The second annotation draws in the right position (mouse position).

I can reproduce the problem when there is a scale factor on one of the monitors. When I set this to the same value as the other monitor there is not offset.

To reproduce I found the following settings in hyprland.conf.

does not work:

monitor=eDP-1,preferred,auto,1.6

this works:

monitor=eDP-1,preferred,auto,1

When I move the window to the other monitor then it also works with the scale factor.

[RobertMueller2]

Can't reproduce the behaviour in a sway session. I've also tried arbitrary incorrect scale factor settings for the drawing area for a different issue recently and never saw this.

Which hyprland and Satty versions are you using, please?

[pstuifzand]

I used the latest version of Satty from main. This commit.

$ hyprctl version
Hyprland 0.51.1 built from branch  at commit 71a1216abcc7031776630a6d88f105605c4dc1c9  ([gha] Nix: update inputs).
Date: Mon Sep 22 22:54:03 2025
Tag: v0.51.1, commits: 6436
built against:
 aquamarine 0.9.5
 hyprlang 0.6.3
 hyprutils 0.10.0
 hyprcursor 0.1.13
 hyprgraphics 0.2.0

It seems to depend on two or more monitors where the dpi scale of the first monitor is different from the other monitor where the program is shown.

[RobertMueller2]

It seems to depend on two or more monitors where the dpi scale of the first monitor is different from the other monitor where the program is shown.

Yeah, that's what I got here as well when trying in a sway session earlier.

[pstuifzand]

I made a recording of what I see with the latest main version. You can see that the first arrow is drawn in a different position from the mouse pointer. The second arrow is drawn in the right position.

Another thing I just noticed is that it also happens each time after I move the window to another monitor. For the monitor with the higher scale the arrow is drawn in the bottom right, for the monitor with the lower scale, it is drawn more to the top left.

https://github.com/user-attachments/assets/62c58263-03b0-4733-8be6-51e725c76760

[RobertMueller2]

Thanks for the video. I've tried to reproduce this in a Hyprland session with one screen at 1.6 scale factor. My Hyprland is the Debian package at 0.41.2 and I could not reproduce it there.

Either there are other relevant factors for this behaviour like additional config or different hardware, or it depends on the Hyprland version.

At this point, I can't easily use the version you are using. I'm normally not using Hyprland, and building it has become a bit of a bother with all the library dependencies it has now. I'll try a repro with that when I get a chance, but that might not be very soon. Until then we won't know for sure, unless it really is a Hyprland version depending issue and it gets fixed in the meantime.

[RobertMueller2]

Maybe you could share a WAYLAND_DEBUG log from starting satty, on the off chance that anything sticks out. I wouldn't hold my breath about that one, though.