Ubuntu Studio 26.04 Manually set display coordinates for multi-displays?
https://askubuntu.com/questions/1566168/ubuntu-studio-26-04-manually-set-display-coordinates-for-multi-displays
Just setting up Ubuntu Studio 26.04 and having issue with multiple displays.
I have four displays, three side by side and one centered above those. The one above is 3840x2160. The three side by side are 1680x1050, 1920x1050, 1680x1050 respectively.
In the KDE settings app the displays snap to each other when dragging them into the positions I want them. Unfortunately, they all want to align so that they share the same bottom Y coordinate. They don't seem to be able to use the top coordinates for snapping. That means that, instead of being able to align the 4k display's bottom to sit snugly at the top of the three smaller displays, the center one of the three lower displays overlaps into the 4k's display area. This is due to the different resolutions of the center vs the side displays. If I try to address it by moving the center screen lower, the side screens develope a gap causing mouse issues when trying to cross over between displays.
I've not found a way to set the coordinates manually, something I used to be able to do with xorg.
I can think of a couple of workarounds but don't know if they're possible and haven't found anything on them yet. The first would be to turn off the snapping and be able to drag the displays where they need to be. Zooming would be helpful if this is used. I dooubt it's possible but, if it is, could someone point me to how to do it?
The second would be to find some file someplace that I could manually enter the XY coordinates in, either that or find a way to do so in the KDE settings. Again, if someone could point me to a way to do this, it's much appreciated.
Lastly, I'm using the nouveau driver for this. When I tried an install with the nvidia driver there were other, worse issues than these, like no 4k display at all. Card is RTX3060.
thanks,
babag
More in response to info from Daniel T.
I'm a little confused about how the json file interacts with the files I find in the ~/.local/share/kscreen/ location. I also have some confusion over the number of files I find there. My /home directory has migrated through a number of upgrades so I'm guessing that the various reinstalls through that process has caused files to be generated that are no longer in use. The Ubuntu installation media always has trouble with my multi-display setup so I always unplug all but one display when reinstalling. Also, sometimes when replugging after installation, one or more of the displays might not have its plug seated properly causing the setup to look like it has fewer displays than it should. Since some of the files I'm seeing have info for sometimes two, sometimes three displays, I'm guessing they were generated by this process. The files with the current or closest to current date seem to be correct.
In the ./local/share/kscreen directory I'm seeing a subdirectory called "outputs". That directory contains a bunch of files, four of which seem to correspond to my current displays and are named with a long hash for their filename. These files contain display settings but no position info. These hash-filenames appear in another file, directly in the /.local/share/kscreen directory, which does contain position info. Example:
"enabled": true,
"id": "81b7337a882eb972842e1b9f28a70351",
"metadata": {
"fullname": "xrandr-Envision Peripherals, Inc-G2016wa1-K1581CA002049",
"name": "HDMI-0"
},
"mode": {
"refresh": 59.95425033569336,
"size": {
"height": 1050,
"width": 1680
}
},
"overscan": 0,
"pos": {
"x": 3600,
"y": 2160
},
"priority": 1,
"rgbrange": 0,
"rotation": 1,
"scale": 1,
"vrrpolicy": 2
},
The x/y of 3600 and 2160 would be the coordinates for this display's positioning. I'm guessing that this might be something I would edit to make the fine adjustments I want to make.
However, there's the json file, which also contains these coordinates. (Unfortunately, I can't post an excerpt from that file as my 26.04 system keeps having display and crashing issues and I'm having to write this from my old 24.04 system, which doesn't seem to have that file, to be able to get through this posting.)
So, I don't know whether one of these files populates the other or if I have to edit both in order to make my adjustments.
Thanks for any clarification on this. Does seem like an editable text box in the main KDE System Setting app for Displays would be a far less arcane way of going about this. As I recall, the Nvidia app had that. Not in the 26.04 configuration though.
thanks,
BabaG
