public static extern int SetWorldTransform(IntPtr hdc, ref XFORM lpXform);
public static extern int ExtCreateRegion(ref XFORM lpXform, int nCount, ref RGNDATA lpRgnData);
public static extern int ModifyWorldTransform(IntPtr hdc, ref XFORM lpXform, int iMode);
public static extern int CombineTransform(ref XFORM lpxformResult, ref XFORM lpxform1, ref XFORM lpxform2);