Merge pull request #88496 from bruvzg/d3d12_dyn_load

[Windows] Make D3D12 loading dynamic to support pre-Windows 10 versions.

3 files changed, 44 insertions, 12 deletions

diff --git a/drivers/d3d12/rendering_context_driver_d3d12.cpp b/drivers/d3d12/rendering_context_driver_d3d12.cpp
index ad3b793305..1bd6483bfd 100644
--- a/drivers/d3d12/rendering_context_driver_d3d12.cpp
+++ b/drivers/d3d12/rendering_context_driver_d3d12.cpp
@@ -83,17 +83,28 @@ RenderingContextDriverD3D12::RenderingContextDriverD3D12() {
 }
 
 RenderingContextDriverD3D12::~RenderingContextDriverD3D12() {
+	if (lib_d3d12) {
+		FreeLibrary(lib_d3d12);
+	}
+	if (lib_dxgi) {
+		FreeLibrary(lib_dxgi);
+	}
 }
 
 Error RenderingContextDriverD3D12::_init_device_factory() {
 	uint32_t agility_sdk_version = GLOBAL_GET("rendering/rendering_device/d3d12/agility_sdk_version");
 	String agility_sdk_path = String(".\\") + Engine::get_singleton()->get_architecture_name();
 
+	lib_d3d12 = LoadLibraryW(L"D3D12.dll");
+	ERR_FAIL_NULL_V(lib_d3d12, ERR_CANT_CREATE);
+
+	lib_dxgi = LoadLibraryW(L"DXGI.dll");
+	ERR_FAIL_NULL_V(lib_dxgi, ERR_CANT_CREATE);
+
 	// Note: symbol is not available in MinGW import library.
-	PFN_D3D12_GET_INTERFACE d3d_D3D12GetInterface = (PFN_D3D12_GET_INTERFACE)GetProcAddress(LoadLibraryW(L"D3D12.dll"), "D3D12GetInterface");
-	if (d3d_D3D12GetInterface == nullptr) {
-		// FIXME: Is it intended for this to silently return when it fails to find the symbol?
-		return OK;
+	PFN_D3D12_GET_INTERFACE d3d_D3D12GetInterface = (PFN_D3D12_GET_INTERFACE)(void *)GetProcAddress(lib_d3d12, "D3D12GetInterface");
+	if (!d3d_D3D12GetInterface) {
+		return OK; // Fallback to the system loader.
 	}
 
 	ID3D12SDKConfiguration *sdk_config = nullptr;
@@ -109,18 +120,22 @@ Error RenderingContextDriverD3D12::_init_device_factory() {
 		}
 		sdk_config->Release();
 	}
-
 	return OK;
 }
 
 Error RenderingContextDriverD3D12::_initialize_debug_layers() {
 	ComPtr<ID3D12Debug> debug_controller;
 	HRESULT res;
+
 	if (device_factory) {
 		res = device_factory->GetConfigurationInterface(CLSID_D3D12DebugGodot, IID_PPV_ARGS(&debug_controller));
 	} else {
-		res = D3D12GetDebugInterface(IID_PPV_ARGS(&debug_controller));
+		PFN_D3D12_GET_DEBUG_INTERFACE d3d_D3D12GetDebugInterface = (PFN_D3D12_GET_DEBUG_INTERFACE)(void *)GetProcAddress(lib_d3d12, "D3D12GetDebugInterface");
+		ERR_FAIL_NULL_V(d3d_D3D12GetDebugInterface, ERR_CANT_CREATE);
+
+		res = d3d_D3D12GetDebugInterface(IID_PPV_ARGS(&debug_controller));
 	}
+
 	ERR_FAIL_COND_V(!SUCCEEDED(res), ERR_QUERY_FAILED);
 	debug_controller->EnableDebugLayer();
 	return OK;
@@ -128,7 +143,12 @@ Error RenderingContextDriverD3D12::_initialize_debug_layers() {
 
 Error RenderingContextDriverD3D12::_initialize_devices() {
 	const UINT dxgi_factory_flags = use_validation_layers() ? DXGI_CREATE_FACTORY_DEBUG : 0;
-	HRESULT res = CreateDXGIFactory2(dxgi_factory_flags, IID_PPV_ARGS(&dxgi_factory));
+
+	typedef HRESULT(WINAPI * PFN_DXGI_CREATE_DXGI_FACTORY2)(UINT, REFIID, void **);
+	PFN_DXGI_CREATE_DXGI_FACTORY2 dxgi_CreateDXGIFactory2 = (PFN_DXGI_CREATE_DXGI_FACTORY2)(void *)GetProcAddress(lib_dxgi, "CreateDXGIFactory2");
+	ERR_FAIL_NULL_V(dxgi_CreateDXGIFactory2, ERR_CANT_CREATE);
+
+	HRESULT res = dxgi_CreateDXGIFactory2(dxgi_factory_flags, IID_PPV_ARGS(&dxgi_factory));
 	ERR_FAIL_COND_V(!SUCCEEDED(res), ERR_CANT_CREATE);
 
 	// Enumerate all possible adapters.
diff --git a/drivers/d3d12/rendering_context_driver_d3d12.h b/drivers/d3d12/rendering_context_driver_d3d12.h
index 694d0b3e4c..f74105ed3d 100644
--- a/drivers/d3d12/rendering_context_driver_d3d12.h
+++ b/drivers/d3d12/rendering_context_driver_d3d12.h
@@ -107,6 +107,9 @@ public:
 		bool needs_resize = false;
 	};
 
+	HMODULE lib_d3d12 = nullptr;
+	HMODULE lib_dxgi = nullptr;
+
 	IDXGIAdapter1 *create_adapter(uint32_t p_adapter_index) const;
 	ID3D12DeviceFactory *device_factory_get() const;
 	IDXGIFactory2 *dxgi_factory_get() const;
diff --git a/drivers/d3d12/rendering_device_driver_d3d12.cpp b/drivers/d3d12/rendering_device_driver_d3d12.cpp
index b4bbc44d93..287726f4db 100644
--- a/drivers/d3d12/rendering_device_driver_d3d12.cpp
+++ b/drivers/d3d12/rendering_device_driver_d3d12.cpp
@@ -3222,7 +3222,7 @@ Vector<uint8_t> RenderingDeviceDriverD3D12::shader_compile_binary_from_spirv(Vec
 		root_sig_desc.Init_1_1(root_params.size(), root_params.ptr(), 0, nullptr, root_sig_flags);
 
 		ComPtr<ID3DBlob> error_blob;
-		HRESULT res = D3DX12SerializeVersionedRootSignature(&root_sig_desc, D3D_ROOT_SIGNATURE_VERSION_1_1, root_sig_blob.GetAddressOf(), error_blob.GetAddressOf());
+		HRESULT res = D3DX12SerializeVersionedRootSignature(context_driver->lib_d3d12, &root_sig_desc, D3D_ROOT_SIGNATURE_VERSION_1_1, root_sig_blob.GetAddressOf(), error_blob.GetAddressOf());
 		ERR_FAIL_COND_V_MSG(!SUCCEEDED(res), Vector<uint8_t>(),
 				"Serialization of root signature failed with error " + vformat("0x%08ux", (uint64_t)res) + " and the following message:\n" + String((char *)error_blob->GetBufferPointer(), error_blob->GetBufferSize()));
 
@@ -3483,7 +3483,10 @@ RDD::ShaderID RenderingDeviceDriverD3D12::shader_create_from_bytecode(const Vect
 
 	const uint8_t *root_sig_data_ptr = binptr + read_offset;
 
-	HRESULT res = D3D12CreateRootSignatureDeserializer(root_sig_data_ptr, binary_data.root_signature_len, IID_PPV_ARGS(shader_info_in.root_signature_deserializer.GetAddressOf()));
+	PFN_D3D12_CREATE_ROOT_SIGNATURE_DESERIALIZER d3d_D3D12CreateRootSignatureDeserializer = (PFN_D3D12_CREATE_ROOT_SIGNATURE_DESERIALIZER)(void *)GetProcAddress(context_driver->lib_d3d12, "D3D12CreateRootSignatureDeserializer");
+	ERR_FAIL_NULL_V(d3d_D3D12CreateRootSignatureDeserializer, ShaderID());
+
+	HRESULT res = d3d_D3D12CreateRootSignatureDeserializer(root_sig_data_ptr, binary_data.root_signature_len, IID_PPV_ARGS(shader_info_in.root_signature_deserializer.GetAddressOf()));
 	ERR_FAIL_COND_V_MSG(!SUCCEEDED(res), ShaderID(), "D3D12CreateRootSignatureDeserializer failed with error " + vformat("0x%08ux", (uint64_t)res) + ".");
 	read_offset += binary_data.root_signature_len;
 
@@ -6033,17 +6036,23 @@ Error RenderingDeviceDriverD3D12::_initialize_device() {
 	HRESULT res;
 
 	if (is_in_developer_mode()) {
+		typedef HRESULT(WINAPI * PFN_D3D12_ENABLE_EXPERIMENTAL_FEATURES)(_In_ UINT, _In_count_(NumFeatures) const IID *, _In_opt_count_(NumFeatures) void *, _In_opt_count_(NumFeatures) UINT *);
+		PFN_D3D12_ENABLE_EXPERIMENTAL_FEATURES d3d_D3D12EnableExperimentalFeatures = (PFN_D3D12_ENABLE_EXPERIMENTAL_FEATURES)(void *)GetProcAddress(context_driver->lib_d3d12, "D3D12EnableExperimentalFeatures");
+		ERR_FAIL_NULL_V(d3d_D3D12EnableExperimentalFeatures, ERR_CANT_CREATE);
+
 		UUID experimental_features[] = { D3D12ExperimentalShaderModels };
-		D3D12EnableExperimentalFeatures(1, experimental_features, nullptr, nullptr);
+		d3d_D3D12EnableExperimentalFeatures(1, experimental_features, nullptr, nullptr);
 	}
 
 	ID3D12DeviceFactory *device_factory = context_driver->device_factory_get();
 	if (device_factory != nullptr) {
 		res = device_factory->CreateDevice(adapter.Get(), D3D_FEATURE_LEVEL_11_0, IID_PPV_ARGS(device.GetAddressOf()));
 	} else {
-		res = D3D12CreateDevice(adapter.Get(), D3D_FEATURE_LEVEL_11_0, IID_PPV_ARGS(device.GetAddressOf()));
-	}
+		PFN_D3D12_CREATE_DEVICE d3d_D3D12CreateDevice = (PFN_D3D12_CREATE_DEVICE)(void *)GetProcAddress(context_driver->lib_d3d12, "D3D12CreateDevice");
+		ERR_FAIL_NULL_V(d3d_D3D12CreateDevice, ERR_CANT_CREATE);
 
+		res = d3d_D3D12CreateDevice(adapter.Get(), D3D_FEATURE_LEVEL_11_0, IID_PPV_ARGS(device.GetAddressOf()));
+	}
 	ERR_FAIL_COND_V_MSG(!SUCCEEDED(res), ERR_CANT_CREATE, "D3D12CreateDevice failed with error " + vformat("0x%08ux", (uint64_t)res) + ".");
 
 	if (context_driver->use_validation_layers()) {