Optimization in AllocatorPimpl::GetResourceAllocationInfo
diff --git a/src/D3D12MemAlloc.cpp b/src/D3D12MemAlloc.cpp
index bf8b43d..d5ad4b0 100644
--- a/src/D3D12MemAlloc.cpp
+++ b/src/D3D12MemAlloc.cpp
@@ -5180,6 +5180,22 @@
D3D12_RESOURCE_ALLOCATION_INFO AllocatorPimpl::GetResourceAllocationInfo(D3D12_RESOURCE_DESC& inOutResourceDesc) const
{
+ /* Optional optimization: Microsoft documentation says:
+ https://docs.microsoft.com/en-us/windows/win32/api/d3d12/nf-d3d12-id3d12device-getresourceallocationinfo
+
+ Your application can forgo using GetResourceAllocationInfo for buffer resources
+ (D3D12_RESOURCE_DIMENSION_BUFFER). Buffers have the same size on all adapters,
+ which is merely the smallest multiple of 64KB that's greater or equal to
+ D3D12_RESOURCE_DESC::Width.
+ */
+ if(inOutResourceDesc.Alignment == 0 &&
+ inOutResourceDesc.Dimension == D3D12_RESOURCE_DIMENSION_BUFFER)
+ {
+ return {
+ AlignUp<UINT64>(inOutResourceDesc.Width, D3D12_DEFAULT_RESOURCE_PLACEMENT_ALIGNMENT), // SizeInBytes
+ D3D12_DEFAULT_RESOURCE_PLACEMENT_ALIGNMENT}; // Alignment
+ }
+
#if D3D12MA_USE_SMALL_RESOURCE_PLACEMENT_ALIGNMENT
if(inOutResourceDesc.Alignment == 0 &&
inOutResourceDesc.Dimension == D3D12_RESOURCE_DIMENSION_TEXTURE2D &&
