Created attachment 140140 [details] [review]
Patch for the 'deferred' demo
when there's an unused color attachment in a subpass, it looks like fragment shader outputs are not written to the correct attachments, i.e. if attachment reference 1 is VK_ATTACHMENT_UNUSED, the fragment shader output at location 2 is written to the 3rd attachment and the output at location 3 is discarded entirely. This causes rendering issues in Vampyr on DXVK.
The attached patch for Sasha Willems 'deferred' demo demonstrates the issue. It works as expected on amdvlk. Mind that the affected fragment shader needs to be recompiled manually.
Well, AMDVLK hangs on Polaris/Vega here. (I recompiled that fragment shader manually).
https://patchwork.freedesktop.org/patch/229361/ should fix this.