[PATCH vkd3d 4/7] vkd3d: Allow D3D12_SMALL_RESOURCE_PLACEMENT_ALIGNMENT only for small textures.

[Józef Kucia]

From: Józef Kucia

Use a simple heuristic to decide if a resource is "small". The heuristic
is based on theoretical constraints for the most detailed mip level of
small resources. Those constraints are mentioned in D3D12 validation
layer errors and in the DirectX 12 Graphics samples.

Signed-off-by: Józef Kucia 
---
 libs/vkd3d/device.c | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/libs/vkd3d/device.c b/libs/vkd3d/device.c
index 7c2006232795..7a6dcb68862d 100644
--- a/libs/vkd3d/device.c
+++ b/libs/vkd3d/device.c
@@ -2076,6 +2076,7 @@ static D3D12_RESOURCE_ALLOCATION_INFO * STDMETHODCALLTYPE d3d12_device_GetResour
 {
     UINT64 default_alignment = D3D12_DEFAULT_RESOURCE_PLACEMENT_ALIGNMENT;
     struct d3d12_device *device = impl_from_ID3D12Device(iface);
+    const struct vkd3d_format *format;
     const D3D12_RESOURCE_DESC *desc;
     bool valid = true;

@@ -2118,7 +2119,26 @@ static D3D12_RESOURCE_ALLOCATION_INFO * STDMETHODCALLTYPE d3d12_device_GetResour
             valid = false;
         }

-        info->Alignment = max(info->Alignment, D3D12_SMALL_RESOURCE_PLACEMENT_ALIGNMENT);
+        if (valid && info->Alignment < D3D12_DEFAULT_RESOURCE_PLACEMENT_ALIGNMENT)
+        {
+            if ((format = vkd3d_format_from_d3d12_resource_desc(desc, 0)))
+            {
+                if (desc->Width * desc->Height * desc->DepthOrArraySize * format->byte_count
+                        >  D3D12_DEFAULT_RESOURCE_PLACEMENT_ALIGNMENT)
+                {
+                    info->Alignment = max(info->Alignment, D3D12_DEFAULT_RESOURCE_PLACEMENT_ALIGNMENT);
+                }
+                else
+                {
+                    info->Alignment = max(info->Alignment, D3D12_SMALL_RESOURCE_PLACEMENT_ALIGNMENT);
+                }
+            }
+            else
+            {
+                WARN("Invalid format %#x.\n", desc->Format);
+                valid = false;
+            }
+        }
     }

if (valid && desc->Alignment % info->Alignment)