imgui dx11 impl shutdown

hw3d/Graphics.cpp

@@ -114,6 +114,11 @@ Graphics::Graphics( HWND hWnd )
 	ImGui_ImplDX11_Init( pDevice.Get(),pContext.Get() );
 }
 
+Graphics::~Graphics()
+{
+	ImGui_ImplDX11_Shutdown();
+}
+
 void Graphics::EndFrame()
 {
 	// imgui frame end

hw3d/Graphics.h

@@ -54,7 +54,7 @@ public:
 	Graphics( HWND hWnd );
 	Graphics( const Graphics& ) = delete;
 	Graphics& operator=( const Graphics& ) = delete;
-	~Graphics() = default;
+	~Graphics();
 	void EndFrame();
 	void BeginFrame( float red,float green,float blue ) noexcept;
 	void DrawIndexed( UINT count ) noexcept(!IS_DEBUG);