imgui/examples/imgui_impl_win32.h

// ImGui Platform Binding for: Windows (standard windows API for 32 and 64 bits applications)
// This needs to be used along with a Renderer (e.g. DirectX11, OpenGL3, Vulkan..)

IMGUI_API bool        ImGui_ImplWin32_Init(void* hwnd);
IMGUI_API void        ImGui_ImplWin32_Shutdown();
IMGUI_API void        ImGui_ImplWin32_NewFrame();

// Handler for Win32 messages, update mouse/keyboard data.
// You may or not need this for your implementation, but it can serve as reference for handling inputs.
// Intentionally commented out to avoid dragging dependencies on <windows.h> types. You can copy the extern declaration in your code.
/*
IMGUI_API LRESULT   ImGui_ImplWin32_WndProcHandler(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam);
*/