I’d like to use xrandr to create a mode which is double the number of physical pixels on my screen, and then scale it down to exactly fit i.e. my screen has 2560x1440 real pixels and i want to create a 5120x2880 mode to render the desktop to, and then scale it by a factor of 0.5 in each dimension.
This should in theory give a sharper desktop from averaging 4 pixels to 1. Apple does this trick.
With all the various options on xrandr I just can’t get this to work. Is it possible?