Adding HDR support to retro games

RetroArch Additions Shaders
#1

Having recently picked up an HDR capable display I’m a bit disappointed by the dearth of HDR content on PC. It’s pretty new/rate tech, especially on monitors, although in my case it’s a TV in my living room that I have a HTPC hooked up to for, amongst other things, retro gaming.

I was wondering if people think it would be feasible/useful to have Retroarch push out an HDR signal, either via a shader or as something built into the main app. Forgive me as I haven’t actually done any HDR development myself so am a little out of my comfort zone on this, but it seems that perhaps through some color interpolation or something we might be able to add HDR to retro games that didn’t have it before. Maybe it would just make them look like ass though, I’m not sure. Would love to know what people think!

#2

There’s a slang/vulkan shader already that does tonemapping for use with an HDR display, the problem for me is that I don’t know how to tell a display “hey, this is HDR content” from within a program.

#3

I’ve heard that full-screen Nvidia apps can push a display into HDR mode in a couple games (shadow warrior 2 was the first I believe). So, I imagine the Vulkan shader or retroarch could also send a signal to the TV to operate in HDR mode. Seems like Vulkan does support this, https://github.com/SaschaWillems/Vulkan#high-dynamic-range .