OK, just updated to 5.34pre7, and a unified hidpi theme (see the original post).
For purposes of people updating other themes to HiDPI/Retina support -- I wouldn't do this yet, really, as this stuff is in flux. But if you insist on doing it for your own enjoyment, knowing that they will likely break before a releasable version gets released, here are the things to know:
- make the images double-size-ish, except for item_*
- make double-size-ish item_*_hidpi (for Windows)
- roughly double most font sizes in the theme
- add a global_scale 2.0 line to the rtconfig.txt
You can do global_scale 1.5 or otherwise on Windows, but on macOS it must be 2.0 to enable Retina.
That is all for now.