Labels:text | screenshot | font | number | diagram | line | parallel | document OCR: Trail edge polygon M. X=100 Lead edge polygon R. x=110| > |Lead edge polygon S. x=111 Active polygon list Current edge, since it's a trating edge, remove polygon M from the active polygon list. Head of APL Polygon M became nearest at x=18 Remove polygon M from the APL Polygon M is on top of the APL; ; meaning it's currently visible {the nearest polygon as we reach this. pixel), so we amit a span starting at the coordinate at which polygon M : Polygon J became visible (x=18), and ending al the current coordinate (x=100), Mark that polygon J became visible at x=100 If polygon M had not been on top of the APL: we wouldn't have done anything except remove it from the APL Polygon L Figure 4: Deactivating a polygon when a trailing edge is encountered in the AEL.
