Aliasing Barrier problem in Horizon Zero Dawn

[Robin Kertels]

Horizon Zero Dawn recently got an update doing the following:

Create two textures that share the same memory.

• Use texture 1 in a render pass.
• Issue a ResourceBarrier call that transitions texture 1 from D3D12_RESOURCE_RENDERTARGET to D3D12_RESOURCE_STATE_PIXEL_SHADER_RESOURCE and an aliasing barrier from another to texture 2.
• Use contents of texture 1 in another render pass.

What ends up happening is that VKD3D-Proton does a VK_IMAGE_LAYOUT_UNDEFINED -> whatever common layout is barrier but the game relies on the contents of texture 1 from that earlier render pass.

I'm not sure what the correct fix is. Maybe treat aliasing barriers just as a wait & flush and rely on the game calling DiscardResource, CopyResource or any of the clear functions to re-initialize it with a proper VkImageLayout? Doing this fixes the black screen I was getting with FSR enabled.

It does not fix the broken TAA on vegetation. That's an unrelated issue. (Which seems to come down to fp issues with a depth prepass.)