ATOM WindowAtom = NULL;
HWND Window = NULL;

int main()
{
	WNDCLASSEX wndclassex;

	// open primary window
	ZeroMemory(&wndclassex, sizeof(WNDCLASSEX));
	wndclassex.cbSize = sizeof(WNDCLASSEX);
	wndclassex.style = CS_CLASSDC;
	wndclassex.lpfnWndProc = (WNDPROC)WindowProc;
	wndclassex.cbClsExtra = 0;
	wndclassex.cbWndExtra = 0;
	wndclassex.hInstance = (HINSTANCE)GetModuleHandle(NULL);
	wndclassex.hIcon = LoadIcon((HINSTANCE)GetModuleHandle(NULL), MAKEINTRESOURCE(IDI_MAINICON));
	wndclassex.hCursor = LoadCursor((HINSTANCE)GetModuleHandle(NULL), MAKEINTRESOURCE(IDC_POINTER));
	wndclassex.hbrBackground = (HBRUSH)GetStockObject(BLACK_BRUSH);
	wndclassex.lpszMenuName = NULL;
	wndclassex.lpszClassName = CLASS_NAME;
	wndclassex.hIconSm = LoadIcon((HINSTANCE)GetModuleHandle(NULL), MAKEINTRESOURCE(IDI_MAINICON));
	WindowAtom = RegisterClassEx(&wndclassex);
	if (!WindowAtom)
	{
		printf("ERROR: !RegisterClassEx(...)\n");
		printf("ERROR: GetLastError() == %lu\n", GetLastError());
		goto exit;
	}
	Window = CreateWindow(CLASS_NAME, TITLE,
		WS_CAPTION | WS_SYSMENU,
		0, 0, 640, 480,
		NULL, NULL,
		(HINSTANCE)GetModuleHandle(NULL), NULL);
	if (!Window)
	{
		printf("ERROR: !CreateWindow(...)\n");
		printf("ERROR: GetLastError() == %lu\n", GetLastError());
		goto exit;
	}
	ShowWindow(Window, SW_NORMAL);
	UpdateWindow(Window);

	// message pump here

	// exit
	return 0;

exit:
	// wait for key press
	printf("\nHit any key to continue...");
	getch();
	return 0;
}

// window handler
LRESULT CALLBACK WindowProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
	switch (uMsg)
	{
	case WM_CLOSE:
		DestroyWindow(hWnd);
		return 0;
	case WM_DESTROY:
		PostQuitMessage(0);
		return 0;
	}

	// not handled
	return DefWindowProc(hWnd, uMsg, lParam, wParam);
}