Curious Vulkan Layer Behavior: DOOM Eternal

[Kaldaien]

It has come to my attention that if the Vulkan layer is disabled for DOOM Eternal, the Steam overlay has an unintended secondary path into the game through Vk -> DXGI SwapChain interop happening at the NVIDIA driver level (used for NvAPI's HDR, among other driver-specific stuff).

I would advise against trying to render into the game's interop DXGI SwapChains because as soon as Steam latches onto one of these it starts to cause problems w/ third-party overlays (i.e. RTSS).

Competing overlays will behave as though the SwapChain is being destroyed and then re-created every 2-3 frames.


Tl;Dr: D3D11 needs to be ignored in this game.


Is there a way to tell the Steam overlay not to initialize specific APIs?

DISABLE_VK_LAYER_VALVE_steam_overlay_1

That is related, but the opposite of what is needed :P

[Kaldaien]

Also, on a sort of related matter...

I patched the Steam overlay ~2 years ago to handle HDR in D3D11. Is there someone I can talk to about getting this an actual platform feature?

The overlay needs some extra brains to handle colorspace processing (Rec 2020 <--> sRGB gamut and sRGB <--> PQ gamma). I did all that by ammending a few new fields to your shaders to denote colorspace. I also added a luminance setting since the overlay's too dim to be seen in games that use scRGB HDR.

I am fairly certain this will not take too much effort for you guys to implement. I solved HDR screenshot capture too, but that is _extremely_ complicated stuff that would take me a month to explain ;)