A method of converting an input path, a method of labeling a segment of an input path as internal or external, a method of rendering an input path, and a method of drawing an outline of an input path

摘要

PROBLEM TO BE SOLVED: To convert a two-dimensional input path defined according to a nonzero winding rule to an equivalent output path.SOLUTION: Degenerate segments and degenerate contours of an input path are removed. Intersections of the input path are determined. Contours of the input path that include intersections are marked. Unmarked interior contours are removed. Intersections are linked. The marked contours are walked to form new contours. The marked contours and degenerate contours are removed. The new contours and the unmarked contours are collected to form an equivalent output path. The equivalent output path can be rendered using either the nonzero winding rule or an even-odd parity rule.