A method for generating a mask pattern to be employed in a patterning process. The method including obtaining (i) a first feature patch including a first polygon portion of an initial mask pattern, and (ii) a second feature patch including a second polygon portion of the initial mask pattern; adjusting the second polygon portion at a patch boundary between the first feature patch and the second feature patch such that a difference between the first polygon portion and the second polygon portion at the patch boundary is reduced; and combining the first polygon portion and the adjusted second polygon portion at the patch boundary to form the mask pattern.