The reason I ask is because the current implementation is an annoyance to me and doesn't fit well in the whole scheme.
'HDR monitor' probably means three things:
1. Good contrast
2. Wide gamut
3. Higher bit-depth
1. doesn't require any additional changes in MAME. 2 could be bad if 3 is not present in the monitor as well. Honestly, wide gamut is a pain in the ass and outside of photography really doesn't need to exist, but the next video standards use wide gamuts so I guess we have to live with them. To implement this in MAME is tricky. We'll probably need a third-party color management library and have to override everything the OS does, which can potentially be confusing and annoying, because every OS does color management differently, and there are quirks like how color management doesn't actually work for fullscreen apps on Windows. As far as the shader goes, right now I implemented 8 color space matrices. I might have to generate these matrices in real-time instead. It depends what sort of gamuts are used in these monitors. Hopefully they all just use the UHD standard, but I suspect it's not so simple. If you can, send me info on these monitors.
I want to make a shader for artwork, the glow effect would have to go there, but that's probably a separate project right now.
I can't make any improvements to the vector shader, but I can try to port it to BGFX. Porting is not as trivial as advertised unfortunately.