Editor: Selection behaves incorrectly on high-DPI displays

This is an OpenMW-CS issue. It does not occur in the original TES Construction Set (running through PlayOnMac).

OS: Mac OS 12.0.1 for an M1 MacBook Pro (2021 model)

OpenMW version: I have seen this issue both in the OpenMW-CS that came with the 0.47.0 OpenMW release (built for x86_64 Mac), and my custom build for M1 off of revision 99e4cbf5.

I am using the GOG.com Morrowind GOTY Edition, and for the .omwaddon file I created when I saw this issue, I had Morrowind.esm, Bloodmoon.esm, and Tribunal.esm loaded. This is the English edition of Morrowind.

I do have a number of mods installed (directly into Data Files, I did this before I understood OpenMW's data folders stuff), but none of their ESPs were enabled in OpenMW-CS. I then tried again with a totally pristine Morrowind install, and I got the same exact issue.

To reproduce: Open any cell in the scene editor and try to select something. With the centered cube and spherical selection, the center of the selection is not where you click at all, and dragging to change the selection size behaves in odd ways (it's very hard to explain, but basically you'd expect that if you dragged towards the apparent center of the selection, the radius would shrink, but instead it sometimes grows and sometimes shrinks). With corner-to-corner selection, neither the first nor corners appear where I would expect (i.e. the first corner should be where I start dragging, and the second where I finish dragging).

There are no errors in my openmw-cs.log file (I'm assuming openmw.log itself is for the main OpenMW engine itself, so I didn't check that one for OpenMW-CS issues).

I have seen it in every cell I've tested. Specifically, I've tried the two Seyda Neen exterior cells and the Dagoth Ur exterior cell, and all of them showed the issue.

In the attached image, I clicked on or very near the circled rock (and dragged a tiny distance to make sure the selection box showed up). As you can see, the selection center is nowhere near that rock (this is not corner-to-corner mode, this is centered cube selection mode)