Factorial scaling means being able to set the entire desktop scale to 120%, 140% and so on.
It is important to me because most of the work I do in my PC is text based (coding and research), so being able to scale text and ui elements 'globally' is critical for good visibility.
The word "factorial" makes no sense here. Maybe "fractional"?
Besides, what is the fucking point of "scaling" at the display level? Isn't it exactly equivalent to setting the font size in points using your physical resolution?
No, it's not like setting font size. Actual fractional scaling as done by macOS and Wayland compositors is rendering at 2x and downscaling.
e.g. 1.5 scale on a 3840x2160 display means you have 2560x1440 logical pixels (3840x(1/1.5) = 2560), applications render for 5120x2880 (2560x2=5120) and get downscaled for 3840x2160.
Yeah, I just realized it's called fractional scaling too, my bad.
It is still important though, because on 14inch desktops the Ubuntu interface looks way too small on 100% scale and way too big on 200%. At the end of the day you can think of fractional scaling as giving yourself more screen real-estate while at the same time keeping everything in a readable state.
Most programs aren't coded to have all of their elements scale properly. You have icons, buttons, pictures, etc that may be bit mapped images, then you have other elements that are vector mapped. So if you just change the font size, you can read the text, but it may be in a text box that is too small (so it overflows).
So the best thing you can do, other than re-write all the applications that have been around for the last 30 years or more, is to make the app think it is writing to a display with a specific resolution. Then scale that up to whatever resolution your screen actually is. Then, any element that is bit mapped in the app may not look very crisp, but things like fonts or any element drawn by a UI library can be drawn at the screen's native resolution (because those libraries have been updated to know about the "fake" vs "real" resolution).
This is very similar to when you hit "ctrl +" in a modern web browser. If the web app says "place this element 25 pixels to the right", those are logical pixels and has little to do with actual screen pixels anymore.
It is important to me because most of the work I do in my PC is text based (coding and research), so being able to scale text and ui elements 'globally' is critical for good visibility.
Edit: It's supposed to be 'fractional', my bad.