[Feature Request] mmpx upscaler.

[spinktvis]

For people who love the look of crispy clear pixel art there exists the mmpx scaler, all the relevant info on it can be found here:
https://casual-effects.com/research/McGuire2021PixelArt/index.html

https://casual-effects.com/research/McGuire2021PixelArt/McGuire2021PixelArt.pdf

https://casual-effects.com/research/McGuire2021PixelArt/McGuire2021PixelArt-supplement.zip

Additional information:
mmpx scaler in opengl format:
https://github.com/mgba-emu/mgba/blob/master/res/shaders/mmpx.shader/mmpx.fs

mmpx enhanced scaler in vulkan format:
https://github.com/libretro/slang-shaders/blob/master/edge-smoothing/scalenx/shaders/mmpx-ex.slang

Examples of what the enhanced version enhances compared to the original:
hrydgard/ppsspp#20755
hrydgard/ppsspp#20541
stenzek/duckstation#3443

[drhelius]

Enabling MMPX will disbale scanlines, screen ghosting and video LPF.
Is that right?
I can't see a proper way of applying any of those at the same time as MMPX.

[Ryusennin]

I don't think scanlines look good with such a filter. While some pixels retain their original size, many others become 4 times smaller -- and those get crushed by the scanlines.

[drhelius]

Yeah, also I don't think any other blur or analog effect will combine nice with MMPX either.
So if that's the case it will be very easy to add.

[spinktvis]

Yeah, also I don't think any other blur or analog effect will combine nice with MMPX either. So if that's the case it will be very easy to add.

That's actually ideal, personally I usually dislike anything scanlines, ghosting, bleed, blending, and blur on high resolution displays, so wether in modern or retro games, I disable all that. Current exception is Moonring and Animal Well, gosh it just look so good with it enabled.

And now acting as the devil's advocate, there are high quality scanlines, ghosting, color bleed, blending, and blur scalers available, for example the sections for 'CRT', 'NTSC', and 'Scanlines' in: https://github.com/libretro/slang-shaders/

Additionally within the 'Presets' section (which combines different scalers) its possible to experience a eighties/nineties CRT TV, scanlines, ghosting, bleed, blending, and blur, including the emulation of screen curves, with the exception for the static up close ;-)

[drhelius]

Yes, I know. Geargrafx is also a libretro core after all and can benefit of all those filters in RetroArch.

I can add MMPX but not going to replicate all those filters in the desktop build as my focus is emulation only and not building a frontend.