struct SDL_Window; bool ImGui_ImplSdl_Init(SDL_Window *window); void ImGui_ImplSdl_Shutdown(); bool ImGui_ImplSdl_NewFrame(SDL_Window *window); void ImGui_ImplSdl_InvalidateDeviceObjects(); bool ImGui_ImplSdl_CreateDeviceObjects(); void ImGui_ImplSdl_KeyCallback(int key, int, bool down); void ImGui_ImplSdl_CharCallback(unsigned int c);