Problem
1. Write a routine to implement exterior clipping on any part of a defined picture using any specified window.
2. Write a routine to perform both interior and exterior clipping, given a particular window-system display. Input to the routine is a set of window positions on the screen, the objects to be displayed in each window, and the window priorities. The individual objects are to be clipped to fit into their respective windows, then clipped to remove parts with overlapping windows of higher display priority.