Hardware scaling (handle different logical vs. backing size)

The readme says:

Softbuffer should be used over pixels when its GPU-accelerated post-processing effects are not needed.

When I first read this, it didn't occur to me that "post-processing effects" included scaling. I was thinking it was more about things like CRT simulation. Unfortunately, scaling is often a requirement due to high resolution displays. Anyone doing full frame redraws and desiring good performance (60fps+) will almost certainly need to operate on a smaller buffer that can be scaled up, which pixels can do. I couldn't get acceptable performance with softbuffer and software scaling, although admittedly I didn't try very hard on the scaling algorithm.

I wonder if softbuffer could make an exception and support hardware scaling, if it wouldn't go against the spirit of the project. It feels like an almost table-stakes feature for most real world use.

Start with the README wording about Softbuffer and GPU-accelerated post-processing, then inspect the project’s rendering and buffer-size handling to determine whether hardware scaling fits its design. The issue does not name files or tests; done would require a decided scaling approach and corresponding implementation and coverage.