The principial difference between how Mutter/Gnome and Plasma/ handles hidpi is, that for Mutter/Gnome it works for old apps without any modifications, while the Plasma/Qt approach works only for apps that were modified to use the new APIs.
Yes, the old app on Mutter will be upscaled, but it will be right scale on each monitor in mixed-dpi environment. Yes, even that old wordperfect from 1998. While on Plasma, non-Qt apps will have hard time.
Also, you won't be able to do perfecly fine anything on 150%. How are you going to do 1-pixel wide line? Exact cursor positions? You are not going to. With hw downscaling, yes, you pay the price for larger framebuffer and you get good approximations, but you also avoid a great deal of corner cases, that most software users are running is never going to solve.
> Also, you won't be able to do perfecly fine anything on 150%. How are you going to do 1-pixel wide line? Exact cursor positions? You are not going to. With hw downscaling, yes, you pay the price for larger framebuffer and you get good approximations, but you also avoid a great deal of corner cases, that most software users are running is never going to solve.
I care more about the performance loss of rendering at excessive resolution than about the 1-pixel imperfections.
> that for Mutter/Gnome it works for old apps without any modifications, while the Plasma/Qt approach works only for apps that were modified to use the new APIs.
You could do a hybrid approach and render old apps at 1x/2x and down/upscale them and let updated apps render at the native resolution.
At least render fonts at native resolution and only up/downscale the rest of the widgets. Scaling fonts can NOT be done by post-processing or it WILL be wrong. (MacOS only scales widgets, images and fonts will always be rendered at native resolution)
Yes, the old app on Mutter will be upscaled, but it will be right scale on each monitor in mixed-dpi environment. Yes, even that old wordperfect from 1998. While on Plasma, non-Qt apps will have hard time.
Also, you won't be able to do perfecly fine anything on 150%. How are you going to do 1-pixel wide line? Exact cursor positions? You are not going to. With hw downscaling, yes, you pay the price for larger framebuffer and you get good approximations, but you also avoid a great deal of corner cases, that most software users are running is never going to solve.