Features:
- produces nearest neighbor look with fractional scales.
- uses texture AA shader code.
- uses hotizontal subpixel scaling.
- due to different pixel sizes, moving sprites change dimension if nearest neighbor is used with fractional scaling. This looks unsteady. This shader uniforms pixel dimensions. Output looks much quieter.
https://forums.libretro.com/t/uniform-nearest-interpolation-shader/41492