Method for pre-clipping a line lying within a clipping rectangular region which is a subset of a region of a display screen

摘要

A method for drawing lines on a graphics device in such manner in that only those points lying inside a specified rectangular area of the device are drawn. Predetermined digital outcodes are generated for defining the endpoints of the lines and a decision is made whether to draw or not draw the lines based on the relationship of the endpoints with respect to both the specified rectangular area of the device, and a second larger rectangular area of the device.