Let us start here, from square one. No, from Zero!

overlay/imgui/impl_spice.h

@@ -0,0 +1,10 @@
+#pragma once
+
+#include <windows.h>
+#include "external/imgui/imgui.h"
+
+IMGUI_IMPL_API bool ImGui_ImplSpice_Init(HWND hWnd);
+IMGUI_IMPL_API void ImGui_ImplSpice_Shutdown();
+IMGUI_IMPL_API void ImGui_ImplSpice_UpdateDisplaySize();
+IMGUI_IMPL_API bool ImGui_ImplSpice_UpdateMouseCursor();
+IMGUI_IMPL_API void ImGui_ImplSpice_NewFrame();