gpu: Set up D3D12 device checks to avoid unnecessary queries

src/gpu/d3d12/SDL_gpu_d3d12.c

@@ -8374,6 +8374,7 @@ static bool D3D12_PrepareDriver(SDL_VideoDevice *_this, SDL_PropertiesID props)
     IDXGIFactory6 *factory6;
     IDXGIAdapter1 *adapter;
     bool supports_64UAVs = false;
+    bool needs_64UAVs = !SDL_GetBooleanProperty(props, SDL_PROP_GPU_DEVICE_CREATE_D3D12_ALLOW_FEWER_RESOURCE_SLOTS_BOOLEAN, false);
 
     // Early check to see if the app has _any_ D3D12 formats, if not we don't
     // have to fuss with loading D3D in the first place.
@@ -8475,23 +8476,29 @@ static bool D3D12_PrepareDriver(SDL_VideoDevice *_this, SDL_PropertiesID props)
 
     SDL_COMPILE_TIME_ASSERT(featurelevel, D3D_FEATURE_LEVEL_CHOICE < D3D_FEATURE_LEVEL_11_1);
 
-    // Check feature level 11_1 first, guarantees 64+ UAVs unlike 11_0 Tier1
+    /* FIXME: If Windows 11 is running and the app has neither DXIL nor TIER2
+     * requirements, we can skip doing any device checks entirely
+     */
+#if 0
+    if (!needs_64UAVs && !has_dxil && WIN_IsWindows11OrGreater()) {
+        IDXGIAdapter1_Release(adapter);
+        IDXGIFactory1_Release(factory);
+
+        SDL_UnloadObject(d3d12Dll);
+        SDL_UnloadObject(dxgiDll);
+
+        return true;
+    }
+#endif
+
     res = pD3D12CreateDevice(
         (IUnknown *)adapter,
-        D3D_FEATURE_LEVEL_11_1,
+        D3D_FEATURE_LEVEL_CHOICE,
         D3D_GUID(D3D_IID_ID3D12Device),
         (void **)&device);
-
     if (SUCCEEDED(res)) {
-        supports_64UAVs = true;
-    } else {
-        res = pD3D12CreateDevice(
-            (IUnknown *)adapter,
-            D3D_FEATURE_LEVEL_CHOICE,
-            D3D_GUID(D3D_IID_ID3D12Device),
-            (void **)&device);
-
-        if (SUCCEEDED(res)) {
+        // Only check for Tier 2 resource binding if the app needs it
+        if (needs_64UAVs) {
             D3D12_FEATURE_DATA_D3D12_OPTIONS featureOptions;
             SDL_zero(featureOptions);
 
@@ -8504,30 +8511,32 @@ static bool D3D12_PrepareDriver(SDL_VideoDevice *_this, SDL_PropertiesID props)
                 supports_64UAVs = true;
             }
         }
-    }
 
-    if (SUCCEEDED(res)) {
-        D3D12_FEATURE_DATA_SHADER_MODEL shaderModel;
-        shaderModel.HighestShaderModel = D3D_SHADER_MODEL_6_0;
+        // Only check for SM6 support if DXIL is provided
+        if (has_dxil) {
+            D3D12_FEATURE_DATA_SHADER_MODEL shaderModel;
+            shaderModel.HighestShaderModel = D3D_SHADER_MODEL_6_0;
 
-        res = ID3D12Device_CheckFeatureSupport(
-            device,
-            D3D12_FEATURE_SHADER_MODEL,
-            &shaderModel,
-            sizeof(shaderModel));
-        if (SUCCEEDED(res) && shaderModel.HighestShaderModel >= D3D_SHADER_MODEL_6_0) {
-            supports_dxil = true;
+            res = ID3D12Device_CheckFeatureSupport(
+                device,
+                D3D12_FEATURE_SHADER_MODEL,
+                &shaderModel,
+                sizeof(shaderModel));
+            if (SUCCEEDED(res) && shaderModel.HighestShaderModel >= D3D_SHADER_MODEL_6_0) {
+                supports_dxil = true;
+            }
         }
 
         ID3D12Device_Release(device);
     }
+
     IDXGIAdapter1_Release(adapter);
     IDXGIFactory1_Release(factory);
 
     SDL_UnloadObject(d3d12Dll);
     SDL_UnloadObject(dxgiDll);
 
-    if (!supports_64UAVs && !SDL_GetBooleanProperty(props, SDL_PROP_GPU_DEVICE_CREATE_D3D12_ALLOW_FEWER_RESOURCE_SLOTS_BOOLEAN, false)) {
+    if (!supports_64UAVs && needs_64UAVs) {
         SDL_LogWarn(SDL_LOG_CATEGORY_GPU, "D3D12: Tier 2 Resource Binding is not supported");
         return false;
     }