Topic: [XDrX-Function(25)] Point set generation convex hull (5 functions)

[xdcad]

xdrx_points_QHull
xdrx_points_MHull  (divide and conquer algorithm)
xdrx_points_GHull  (Scan algorithm)
xdrx_points_GHull1 (Scan algorithm)
xdrx_points_CHull (Double-headed chain algorithm)

Code - Auto/Visual Lisp: [Select]

1. (defun c:tt ()
2.    (if (setq ss (xdrx-ssget "\nSelect Points<Exit>" '((0 . "point"))))
3.      (progn
4.        (xdrx-runtime t)
5.        (xdrx-prompt "\nCollection point...")
6.        (setq pts (xdrx-getpropertyvalue ss "position")
7. pts (apply 'append pts)
8.        )
9.        (setq ti (xdrx-runtime))
10.        (xdrx-prompt (xdrx-string-format "\nPoints collected: %d, time taken: %.2f seconds." (length pts) ti))
11.        (xdrx-prompt "\nCalculate minimum distance point pairs...")
12.        (xdrx-runtime t)
13.        (setq info (xdrx_points_QHull pts))
14.        (xdrx-polyline-make info)
15.        (xdrx-setpropertyvalue (entlast) "color" 1)
16.        (setq ti (xdrx-runtime))
17.        (xdrx-prompt (xdrx-string-format "\nCalculation completed, time taken: %.2f seconds." ti))
18.      )
19.    )
20.    (princ)
21. )