Polygon clipping is one of those humble tasks computers do all the time. It s a basic operation in creating graphic output of all kinds. There are several well-known polygon clipping algorithms, each having its strengths and weaknesses. The oldest one (from 1974) is called the Sutherland-Hodgman algorithm. In its basic form, it is relatively simple. It is also very efficient in two important cases, one being when the polygon is completely inside the boundaries, and the other when it s completely outside.