Direct3D 12: Let platforms report support for direct composition

drivers/d3d12/SCsub

@@ -41,6 +41,12 @@ if env["use_pix"]:
     env_d3d12_rdd.Append(CPPEXTPATH=[env["pix_path"] + "/Include"])
 
 
+# Direct composition.
+
+if "dcomp" in env.get("supported", []):
+    env_d3d12_rdd.Append(CPPDEFINES=["DCOMP_ENABLED"])
+
+
 # Mesa (SPIR-V to DXIL functionality).
 
 mesa_libs = env["mesa_libs"]

drivers/d3d12/rendering_context_driver_d3d12.cpp

@@ -78,9 +78,11 @@ RenderingContextDriverD3D12::~RenderingContextDriverD3D12() {
 	if (lib_dxgi) {
 		FreeLibrary(lib_dxgi);
 	}
+#ifdef DCOMP_ENABLED
 	if (lib_dcomp) {
 		FreeLibrary(lib_dcomp);
 	}
+#endif
 }
 
 Error RenderingContextDriverD3D12::_init_device_factory() {
@@ -93,8 +95,10 @@ Error RenderingContextDriverD3D12::_init_device_factory() {
 	lib_dxgi = LoadLibraryW(L"DXGI.dll");
 	ERR_FAIL_NULL_V(lib_dxgi, ERR_CANT_CREATE);
 
+#ifdef DCOMP_ENABLED
 	lib_dcomp = LoadLibraryW(L"Dcomp.dll");
 	ERR_FAIL_NULL_V(lib_dcomp, ERR_CANT_CREATE);
+#endif
 
 	// Note: symbol is not available in MinGW import library.
 	PFN_D3D12_GET_INTERFACE d3d_D3D12GetInterface = (PFN_D3D12_GET_INTERFACE)(void *)GetProcAddress(lib_d3d12, "D3D12GetInterface");

drivers/d3d12/rendering_context_driver_d3d12.h

@@ -41,6 +41,7 @@
 #undef AS
 #endif
 
+#ifdef DCOMP_ENABLED
 #if (WINVER < _WIN32_WINNT_WIN8) && defined(_MSC_VER)
 #pragma push_macro("NTDDI_VERSION")
 #pragma push_macro("WINVER")
@@ -54,6 +55,7 @@
 #else
 #include <dcomp.h>
 #endif
+#endif
 
 #include <d3dx12.h>
 #include <dxgi1_6.h>
@@ -104,14 +106,18 @@ public:
 		uint32_t height = 0;
 		DisplayServer::VSyncMode vsync_mode = DisplayServer::VSYNC_ENABLED;
 		bool needs_resize = false;
+#ifdef DCOMP_ENABLED
 		ComPtr<IDCompositionDevice> composition_device;
 		ComPtr<IDCompositionTarget> composition_target;
 		ComPtr<IDCompositionVisual> composition_visual;
+#endif
 	};
 
 	HMODULE lib_d3d12 = nullptr;
 	HMODULE lib_dxgi = nullptr;
+#ifdef DCOMP_ENABLED
 	HMODULE lib_dcomp = nullptr;
+#endif
 
 	IDXGIAdapter1 *create_adapter(uint32_t p_adapter_index) const;
 	ID3D12DeviceFactory *device_factory_get() const;

drivers/d3d12/rendering_device_driver_d3d12.cpp

@@ -2609,7 +2609,16 @@ Error RenderingDeviceDriverD3D12::swap_chain_resize(CommandQueueID p_cmd_queue,
 		swap_chain_desc.Height = surface->height;
 
 		ComPtr<IDXGISwapChain1> swap_chain_1;
+#ifdef DCOMP_ENABLED
 		res = context_driver->dxgi_factory_get()->CreateSwapChainForComposition(command_queue->d3d_queue.Get(), &swap_chain_desc, nullptr, swap_chain_1.GetAddressOf());
+#else
+		res = context_driver->dxgi_factory_get()->CreateSwapChainForHwnd(command_queue->d3d_queue.Get(), surface->hwnd, &swap_chain_desc, nullptr, nullptr, swap_chain_1.GetAddressOf());
+		if (!SUCCEEDED(res) && swap_chain_desc.AlphaMode != DXGI_ALPHA_MODE_IGNORE) {
+			swap_chain_desc.AlphaMode = DXGI_ALPHA_MODE_IGNORE;
+			has_comp_alpha[(uint64_t)p_cmd_queue.id] = false;
+			res = context_driver->dxgi_factory_get()->CreateSwapChainForHwnd(command_queue->d3d_queue.Get(), surface->hwnd, &swap_chain_desc, nullptr, nullptr, swap_chain_1.GetAddressOf());
+		}
+#endif
 		ERR_FAIL_COND_V(!SUCCEEDED(res), ERR_CANT_CREATE);
 
 		swap_chain_1.As(&swap_chain->d3d_swap_chain);
@@ -2619,6 +2628,7 @@ Error RenderingDeviceDriverD3D12::swap_chain_resize(CommandQueueID p_cmd_queue,
 		ERR_FAIL_COND_V(!SUCCEEDED(res), ERR_CANT_CREATE);
 	}
 
+#ifdef DCOMP_ENABLED
 	if (surface->composition_device.Get() == nullptr) {
 		using PFN_DCompositionCreateDevice = HRESULT(WINAPI *)(IDXGIDevice *, REFIID, void **);
 		PFN_DCompositionCreateDevice pfn_DCompositionCreateDevice = (PFN_DCompositionCreateDevice)(void *)GetProcAddress(context_driver->lib_dcomp, "DCompositionCreateDevice");
@@ -2648,6 +2658,7 @@ Error RenderingDeviceDriverD3D12::swap_chain_resize(CommandQueueID p_cmd_queue,
 		res = surface->composition_device->Commit();
 		ERR_FAIL_COND_V(!SUCCEEDED(res), ERR_CANT_CREATE);
 	}
+#endif
 
 	res = swap_chain->d3d_swap_chain->GetDesc1(&swap_chain_desc);
 	ERR_FAIL_COND_V(!SUCCEEDED(res), ERR_CANT_CREATE);

platform/windows/detect.py

@@ -241,7 +241,7 @@ def get_flags():
 
     return {
         "arch": arch,
-        "supported": ["d3d12", "mono", "xaudio2"],
+        "supported": ["d3d12", "dcomp", "mono", "xaudio2"],
     }