Are there any ways to do some sort of upscaling for HiDPI displays? I’ve always wondered what MacOS 8 or 9 would feel like with 2x retina style rendering.
> I’ve always wondered what MacOS 8 or 9 would feel like with 2x retina style rendering.
I'm not sure what that would even mean. Most of the UI was drawn from bitmaps - there isn't any higher resolution internal representation of e.g. a window border or a radio button.
What it would mean is something like hq2x, 2xSaI or similar. These algorithms are popularly for emulation of 8 and 16 bit era games consoles. The example image on this Wikipedia page is illustrative of what's possible with a deterministic algorithm:
Imagine what could be possible with a well trained neural network, with knowledge of every icon, every element, and every font glyph at every bitmap size.
I'm not sure what that would even mean. Most of the UI was drawn from bitmaps - there isn't any higher resolution internal representation of e.g. a window border or a radio button.