Low-level native rendering plugin API for D3D11

Does anyone know what the methods exposed in IUnityGraphicsD3D11.h do? Are they documented anywhere?

Specifically, what do these functions do, and how/when to use them:

Code (csharp):

1. ID3D11ShaderResourceView* (UNITY_INTERFACE_API * SRVFromNativeTexture)(UnityTextureID texture);
2. ID3D11Resource* (UNITY_INTERFACE_API * TextureFromNativeTexture)(UnityTextureID texture)

I tried calling the functions with texture IDs provided by Texture.GetNativeTexturePtr in the managed side, but they always returned NULL pointers.

 

Example:

Code (Cpp):

1.  
2. ID3D11Resource* src = interface_->TextureFromNativeTexture(iParams->source);
3. ID3D11Resource* dst = interface_->TextureFromRenderBuffer(iParams->destination);
4. context_->CopyResource(dst, src);
5.