def check_d3d():
	opts.Update(context.getLibraryEnv())
	if opts.getLibraryEnv()['d3d']:
		context.addFiles('win', Split("""
		d3d_system.c
		d3d_display.c
		d3d_bitmap.c
		d3d_keyboard.c
		d3d_window.c
		"""));
		env.Append(LIBS = [ 'd3d9' ])