Merge pull request #2144 from AdamJMiles/patch-7

Clarify offset alignment requirement for subresource

Author: stevewhims

sdk-api-src/content/d3d12/ns-d3d12-d3d12_placed_subresource_footprint.md

@@ -57,7 +57,9 @@ Describes the footprint of a placed subresource, including the offset and the D3
 ### -field Offset
 
 The offset of the subresource within the parent resource, in bytes.
-            The offset between the start of the parent resource and this subresource.
+            The offset between the start of the parent resource and this subresource. 
+            
+This value must be aligned to D3D12_TEXTURE_DATA_PLACEMENT_ALIGNMENT (512) unless <a href="/windows/win32/api/d3d12/ns-d3d12-d3d12_feature_data_d3d12_options13">D3D12_FEATURE_DATA_D3D12_OPTIONS13::UnrestrictedBufferTextureCopyPitchSupported</a> is TRUE.
 
 ### -field Footprint
 
@@ -78,4 +80,4 @@ When copying textures, use this structure along with <a href="/windows/desktop/a
 
 ## -see-also
 
-<a href="/windows/desktop/direct3d12/direct3d-12-structures">Core Structures</a>
+<a href="/windows/desktop/direct3d12/direct3d-12-structures">Core Structures</a>