Merge pull request #12087 from Dentomologist/dx12_use_correct_framebuffer_descriptor

D3D12: Only use framebuffer integer descriptor if allocated

2 files changed, 22 insertions, 4 deletions

diff --git a/Source/Core/VideoBackends/D3D12/DX12Texture.cpp b/Source/Core/VideoBackends/D3D12/DX12Texture.cpp
index f20c37354b..e040d0483d 100644
--- a/Source/Core/VideoBackends/D3D12/DX12Texture.cpp
+++ b/Source/Core/VideoBackends/D3D12/DX12Texture.cpp
@@ -422,6 +422,23 @@ DXFramebuffer::~DXFramebuffer()
   }
 }
 
+const D3D12_CPU_DESCRIPTOR_HANDLE* DXFramebuffer::GetIntRTVDescriptorArray() const
+{
+  if (m_color_attachment == nullptr)
+    return nullptr;
+
+  const auto& handle = m_int_rtv_descriptor.cpu_handle;
+
+  // To save space in the descriptor heap, m_int_rtv_descriptor.cpu_handle.ptr is only allocated
+  // when the integer RTV format corresponding to the current abstract format differs from the
+  // non-integer RTV format. Only use the integer handle if it has been allocated.
+  if (handle.ptr != 0)
+    return &handle;
+
+  // The integer and non-integer RTV formats are the same, so use the non-integer descriptor.
+  return GetRTVDescriptorArray();
+}
+
 void DXFramebuffer::Unbind()
 {
   static const D3D12_DISCARD_REGION dr = {0, nullptr, 0, 1};
@@ -556,6 +573,10 @@ bool DXFramebuffer::CreateIRTVDescriptor()
   const bool multisampled = m_samples > 1;
   DXGI_FORMAT non_int_format = D3DCommon::GetRTVFormatForAbstractFormat(m_color_format, false);
   DXGI_FORMAT int_format = D3DCommon::GetRTVFormatForAbstractFormat(m_color_format, true);
+
+  // If the integer and non-integer RTV formats are the same for a given abstract format we can save
+  // space in the descriptor heap by only allocating the non-integer descriptor and using it for
+  // the integer RTV too.
   if (int_format != non_int_format)
   {
     if (!g_dx_context->GetRTVHeapManager().Allocate(&m_int_rtv_descriptor))
diff --git a/Source/Core/VideoBackends/D3D12/DX12Texture.h b/Source/Core/VideoBackends/D3D12/DX12Texture.h
index ea781fd899..2054b195b2 100644
--- a/Source/Core/VideoBackends/D3D12/DX12Texture.h
+++ b/Source/Core/VideoBackends/D3D12/DX12Texture.h
@@ -75,10 +75,7 @@ public:
   {
     return m_render_targets_raw.data();
   }
-  const D3D12_CPU_DESCRIPTOR_HANDLE* GetIntRTVDescriptorArray() const
-  {
-    return m_color_attachment ? &m_int_rtv_descriptor.cpu_handle : nullptr;
-  }
+  const D3D12_CPU_DESCRIPTOR_HANDLE* GetIntRTVDescriptorArray() const;
   const D3D12_CPU_DESCRIPTOR_HANDLE* GetDSVDescriptorArray() const
   {
     return m_depth_attachment ? &m_dsv_descriptor.cpu_handle : nullptr;