Improvement: Add crt post filter for better native res image quality

[gizmo98]

I experimented with libretro shaders and mupen64plus-next/gliden64 with nativres=1 and 320p output. Output results look interesting. 2D elements look better. Lowres textures and low polygon count get quiet good hidden. Blur caused from bad signal quality adds some edge smoothing and reduces dithering artifacts. Is there interest to add such a filter? I think i can use FXAA shader can as a template and add another post processing shader.

CRT shader vs bilinear and nearest:

Libretro forum thread examples: https://forums.libretro.com/t/please-show-off-what-crt-shaders-can-do/19193/5427?u=gizmo98 https://forums.libretro.com/t/please-show-off-what-crt-shaders-can-do/19193/5416?u=gizmo98

Libretro thread: https://forums.libretro.com/t/gizmo-slotmask-crt-shader/41594/5

[gizmo98]

More examples. Nativres=1 vs Nativres=1 with CRT shader:

[olivieryuyu]

nice

[gonetz]

Is there interest to add such a filter? I think i can use FXAA shader can as a template and add another post processing shader.

Yes, the results look interesting. It indeed can be added as another post-processing filter, as FXAA.