diff --git a/vendor/directx/d3d11/d3d11.odin b/vendor/directx/d3d11/d3d11.odin
index ea1e7f5f8..d94c05d06 100644
--- a/vendor/directx/d3d11/d3d11.odin
+++ b/vendor/directx/d3d11/d3d11.odin
@@ -15,6 +15,7 @@ GUID    :: dxgi.GUID
 IID     :: dxgi.IID
 SIZE_T  :: dxgi.SIZE_T
 BOOL    :: dxgi.BOOL
+UINT    :: dxgi.UINT
 
 RECT :: dxgi.RECT
 SIZE :: dxgi.SIZE
@@ -5146,3 +5147,7 @@ MESSAGE_ID :: enum u32 {
 	TRACKED_WORKLOAD_DISJOINT_FAILURE,
 	D3D11_5_MESSAGES_END,
 }
+
+CalcSubresource :: #force_inline proc "contextless" (MipSlice: UINT, ArraySlice: UINT, MipLevels: UINT) -> UINT {
+	return MipSlice + ArraySlice * MipLevels
+}