OUTLINE-CLIPPING ABOUT OVERLAYING SYMBOLS WITH HELP OF ATTRIBUTES OF INTERSECTION

In late years,a method for hidden line processing appears,which is when computer searches for the hidden line of graph,the attributes of intersection points is given,and when rendering the graph,a intersection point is decided whether to output or not according to its sum of attributive value.The advantage of this method is simplicity in calculation,thus the rendering is speed up.However the method is only used in filling or shading of symbols or polygons.This paper discusses mainly the usage of this method in clipping.The method has been tested many times and may not cause disintegrate of current polygon.The result is satisfactory.