index link parameter description type
0 get lines mode If #t, all lines within a circle centered on the endpoint are link candidates. If #f, all lines with an endpoint within the circle are candidates. <boolean>
1 link radius Distance within which lines are considered to be candidates for linking. <number>
2 contrast ratio minimum Minimum relative contrast between linked lines. <number>
3 contrast ratio maximum Maximum relative contrast between linked lines. <number>
4 delta theta maximum Maximum difference in orientation (in radians) between linked lines. <number>
5 end project relative maximum Maximum distance between a line's endpoint and the projection of a second line's opposite endpoint onto that line. <number>
6 lateral distance absolute maximum squared Maximum squared distance between the midpoint of a line and a second line. <number>