Problem
1. Set up a detailed algorithm for the Nicholl-Lee-Nicholl approach to line dipping for any input pair of line endpoints.
2. Compare the number of arithmetic operations performed in NLN algorithm to both the Cohen-Sutherland and the Liang-Barsky line-clipping algorithms for several different line orientations relative to a clipping window.
3. Write a routine to identify concave polygons by calculating cross products of pairs of edge vectors.