Yeah. I don't get it. If you've got a 3840x2160 display, intended use on macOS as a 1920x1080@2x display, what is the advantage of using a 7680x4320 buffer? Everything is drawn at twice the width and height - and then gets scaled down to half the width and height. Is there actually a good reason to do this?
(I use my M4 Mac with 4K displays, and 5120x2880 (2560x1440@2x) buffers. That sort of thing does work, though if you sit closer than I do then you can see the non-integer scaling. Last time I tried a 3840x2160 buffer (1920x1080@2x), that worked. I am still on macOS Sequoia though.)
> what is the advantage of using a 7680x4320 buffer? Everything is drawn at twice the width and height - and then gets scaled down to half the width and height. Is there actually a good reason to do this?
Text rendering looks noticeably better rendered at 2x and scaled down. Apple's 1x font antialiasing is not ideal.
Especially in Catalyst/SwiftUI apps that often don't bother to align drawing to round points, Apple's HiDPI downscaling has some magic in it that their regular text rendering doesn't.
Yes but Apple got to drop subpixel anti-aliasing support because this workaround is "good enough" for all of their built-in displays and overpriced mediocre external ones, so we all get to suffer having to render 4x the pixels than we need.
(I use my M4 Mac with 4K displays, and 5120x2880 (2560x1440@2x) buffers. That sort of thing does work, though if you sit closer than I do then you can see the non-integer scaling. Last time I tried a 3840x2160 buffer (1920x1080@2x), that worked. I am still on macOS Sequoia though.)