Area screenshot has bad quality

[fidelix]

https://i.imgur.com/E15adD0.png

It doesn't matter whether it is PNG or JPG.
As soon as I invoke the area selector, I can already notice everything is super fuzzy.
I'm on Plasma, Kubuntu 20.04, nothing on the console log.

Fullscreen screenshot works fine, and quality is as expected.
Nothing in the logs.

[fidelix]

Unfortunately this makes the application unusable for me.

Would appreciate a fix.

[greg2010]

This most certainly has to do with the screen DPI. I'm experiencing the same issue on a HiDPI laptop (MBP Retina/Arch Linux).

From briefly looking at the docs, it appears that Qt allows for setting a custom scale factor in QPixmap: QPixmap::setDevicePixelRatio. This, however, will not play nicely with a mix of HiDPI and non-HiDPI displays (multi-monitor setups), as someone pointed out on StackOverflow.

Instead, it is suggested to set AA_EnableHighDpiScaling attribute in QCoreApplication.

I have access to both a HiDPI and a non-HiDPI setup (but not a mixed one). If you would like, I can implement the (trivial) change, make sure nothing is exploding in either case, and send a PR.

@Gurkengewuerz