public static extern bool ScreenToClient(IntPtr hWnd, ref POINTAPI pt);
public static extern bool UpdateLayeredWindow(IntPtr hwnd, IntPtr hdcDst, ref POINTAPI pptDst, ref SIZE psize, IntPtr hdcSrc, ref POINTAPI pprSrc, int crKey, ref BLENDFUNCTION pblend, int dwFlags);
public static extern bool ClientToScreen(IntPtr hWnd, ref POINTAPI pt);
public static extern IntPtr MoveToEx(IntPtr hDC, int x, int y, ref POINTAPI lpPoint);
public static extern int SetBrushOrgEx(IntPtr hDC, int x, int y, ref POINTAPI p);