From 14cd30e2c5976a3186ace704bcd26d7d9d1736ea Mon Sep 17 00:00:00 2001
From: Evgeny Makarov <emakarov@nvidia.com>
Date: Thu, 12 Dec 2024 09:21:57 -0800
Subject: [PATCH] Allow readback buffers to be used as resolve destination
 targets

---
 src/d3d12/d3d12-buffer.cpp | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/d3d12/d3d12-buffer.cpp b/src/d3d12/d3d12-buffer.cpp
index 0cbc3a8..7acc32c 100644
--- a/src/d3d12/d3d12-buffer.cpp
+++ b/src/d3d12/d3d12-buffer.cpp
@@ -122,6 +122,15 @@ namespace nvrhi::d3d12
                 break;
         }
 
+        // Allow readback buffers to be used as resolve destination targets
+        if ((buffer->desc.cpuAccess == CpuAccessMode::Read) && (d.initialState == ResourceStates::ResolveDest))
+        {
+            heapProps.Type = D3D12_HEAP_TYPE_CUSTOM;
+            heapProps.CPUPageProperty = D3D12_CPU_PAGE_PROPERTY_WRITE_BACK;
+            heapProps.MemoryPoolPreference = D3D12_MEMORY_POOL_L0;
+            initialState = D3D12_RESOURCE_STATE_RESOLVE_DEST;
+        }
+
         HRESULT res = m_Context.device->CreateCommittedResource(
             &heapProps,
             heapFlags,