[DirectX 12] Backend

Backends/RmlUi_Backend.h

@@ -46,8 +46,61 @@ using KeyDownCallback = bool (*)(Rml::Context* context, Rml::Input::KeyIdentifie
  */
 namespace Backend {
 
+/// @brief This class defines information for not initializating renderers fully. Fully initialization means that renderer on RmlUi side will
+/// initialize device, queues and other things by its own (in case of OpenGL it will load functions & will init OpenGL) so in case where you already
+/// have own renderer and that renderer is initialized you want to prevent a such initialization and thus RmlUi needs to know user data.
+class RmlRenderInitInfo {
+public:
+	/// @brief This is constructor for initializing class
+	/// @param p_user_device ID3D12Device raw pointer (e.g. ID3D12Device* don't pass ComPtr instance!) or you pass VkDevice instance.
+	RmlRenderInitInfo(void* p_window_handle, void* p_user_device, bool use_vsync) :
+		m_is_full_initialization{true}, m_is_use_vsync{use_vsync}, m_p_native_window_handle{p_window_handle}, m_p_user_device{p_user_device}
+	{
+		RMLUI_ASSERT(p_user_device &&
+			"if you want to initialize renderer by system you don't need to pass this parameter as nullptr just use second constructor and set "
+			"is_full_initialization to true!");
+	}
+
+	/// @brief This is constructor for older graphics API where don't require Devices, Queues etc...
+	/// @param p_window_handle HWND or similar types to OS's window handle
+	RmlRenderInitInfo(void* p_window_handle, bool is_full_initialization, bool use_vsync) :
+		m_is_full_initialization{is_full_initialization}, m_is_use_vsync{use_vsync}, m_p_native_window_handle{p_window_handle}, m_p_user_device{}
+	{}
+
+	~RmlRenderInitInfo() {}
+
+	/// @brief Returns hidden type of ID3D12Device* or VkDevice; It is user's responsibility to pass a valid type for it otherwise system will be
+	/// broken and renderer couldn't be initialized!
+	/// @return you need to use reinterpret_cast to ID3D12Device* type or VkDevice. Depends on what user wants to initialize.
+	void* Get_UserDevice() { return this->m_p_user_device; }
+
+	/// @brief Returns hidden type of native window handle (on Windows e.g. HWND)
+	/// @return window native type of handle  (HWND etc depends on OS)
+	void* Get_WindowHandle() { return this->m_p_native_window_handle; }
+
+	/// @brief returns flag of full initialization. It means that if user wants full initialization that system will create and initialize GAPI and
+	/// renderer by its own. In case of OpenGL system loads functions and initialize renderer, io case of DirectX 12 and Vulkan system initializes
+	/// Device, Queues and etc. Otherwise it is not full initialization and user passed own Device, Queues or set is_full_initialize to false in
+	/// the second constructor for older GAPIs like OpenGL
+	/// @param nothing, because it is getter
+	/// @return field of class m_is_full_initialization if it is true it means that user didn't passed Device, Queues from user's renderer or set
+	/// is_full_initialization to true
+	bool Is_FullInitialization(void) const { return this->m_is_full_initialization; }
+
+	bool Is_UseVSync() const { return this->m_is_use_vsync; }
+
+private:
+	bool m_is_full_initialization;
+	/// @brief use vsync feature of render api (if supports at all); true = means enable feature; false = disable feature.
+	bool m_is_use_vsync;
+	/// @brief it is user's handle of OS's handle, so if it is Windows you pass HWND* here
+	void* m_p_native_window_handle;
+	/// @brief Type that hides ID3D12Device*, VkDevice or something else depends on context and which renderer user initializes
+	void* m_p_user_device;
+};
+
 // Initializes the backend, including the custom system and render interfaces, and opens a window for rendering the RmlUi context.
-bool Initialize(const char* window_name, int width, int height, bool allow_resize);
+bool Initialize(const char* window_name, int width, int height, bool allow_resize, RmlRenderInitInfo* p_info = nullptr);
 // Closes the window and release all resources owned by the backend, including the system and render interfaces.
 void Shutdown();
 

Backends/RmlUi_Backend_SDL_GL3.cpp

@@ -125,7 +125,7 @@ struct BackendData {
 };
 static Rml::UniquePtr<BackendData> data;
 
-bool Backend::Initialize(const char* window_name, int width, int height, bool allow_resize)
+bool Backend::Initialize(const char* window_name, int width, int height, bool allow_resize, RmlRenderInitInfo* p_info)
 {
 	RMLUI_ASSERT(!data);