Improve HiDPI support - Githubissues

probonopd commented 3 years ago

Added very basic HiDPI support in https://github.com/helloSystem/ISO/commit/0505c527dce2588979874053ad968ab8c6e909a0.

Issues:

We need a way to detect which devices are actually HiDPI. For now it is blindly assumed that Apple devices with an internal keyboard are HiDPI. (This means that probably all MacBooks are currently treated as HiDPI, which is a placeholder until we find out how do detect HiDPI properly
Qt can be scaled by arbitrary factors
Gtk can only be scaled by a factor of 2, so we are using this for both Qt and Gtk for now. This is not ideal
The mouse cursor is not scaled. How can this be achieved?
Openbox window decorations are not scaled. How can this be achieved?
Rounded corners for Menu need their radius to be calculated based on menu height, or else they will not be changed in HiDPI mode

probonopd commented 3 years ago

Possibly we can make use of https://github.com/linuxhw/EDID

probonopd commented 3 years ago

How can we find out reliably whether we are running on a HiDPI screen?

grep -r "DPI set to" /var/log/Xorg.0.log | tail -n 1 gives

DPI set to (96, 96) for Apple Retina Display
DPI set to (101, 101) for FullHD screen

so it's garbage.

probonopd commented 3 years ago

https://unix.stackexchange.com/questions/75344/how-does-x-server-calculate-dpi

Xorg defaults to 96x96 regardless of monitor resolution. I think this is because programs supply images meant for this standard dpi. It's better to be a little off than to create artifacts by scaling images all the time. My primary monitor's actual DPI is 93.8. However, setting custom DPI is useful for large displays such as large HDTVs whose DPI are much lower than 96.

probonopd commented 3 years ago

For now, consider everything with 1440 and more vertical resolution "HiDPI" https://github.com/helloSystem/ISO/commit/dea7f532becadd40c8d965f08084f4ddf85634c6

helloSystem / hello

Improve HiDPI support #78