When a main figure (FG1) and at least one subordinate figure (FG2) are designated, a processor (11a) obtains, a point of intersection at which a figure element of the main figure (FG1) intersects each figure element, e.g., a linear element (EL.sub.1), constituting the subordinate figure (FG.sub.2). If...http://www.google.com/patents/US5075876?utm_source=gb-gplus-sharePatent US5075876 - Figure hidden-line processing method
