Lisp to count polyline verticies 1

[IFRs]

Can anyone suggest a lisp that counts the number of verticies in a polyline or lwpolyline?

 

[CarlB]

Try this (I didn't, at home and no AC).
If polyline is closed it will count that as an extra vertex. It could be fixed with a check of the "closed flag" if you need it.

(defun c:nvert ()
   (vl-load-com)
   (setq Pl_Ent (car (entsel "\nSelect polyline: ")))
   (setq VL_Obj (vlax-ename->vla-object Pl_Ent))
   (setq endParam (vlax-curve-getEndParam Vl_Obj))
   (setq NumVert (+ 1 endParam))
   (princ (strcat "\n" (rtos NumVert 2 0) " vertices"))
   (princ)
)

 

[IFRs]

Super! How would I also get the length of the polyline?

 

[CarlB]

OK, but next one's gonna cost you
You might change the "c:nvert" since it does more now.

;;routine to provide number vertices and length
;;for a single polyline.  And maybe a few other objects
(defun c:nvert ()
   (vl-load-com)
   (setq Pl_Ent (car (entsel "\nSelect polyline: ")))
   (setq VL_Obj (vlax-ename->vla-object Pl_Ent))
   (setq endParam (vlax-curve-getEndParam Vl_Obj))
   (setq NumVert (+ 1 endParam))
   (setq Pl_Len (vlax-curve-getDistAtParam VL_Obj endParam))
   (princ (strcat "\n" (rtos NumVert 2 0) " vertices"))
   (princ (strcat "\nLength= " (rtos Pl_Len)))
   (princ)
)

 

[IFRs]

Great! Worth all it cost me!! All I have to do now is modify it so for a closed polyline the number of verticies is decreased by one and for an open polyline the number is decreased by 2 (since I'm only interested in verticies where two line segments intersect). Then I'll make it plant appropriate text at or near the polyline. I have got to learn the VBA language - LISP is just not enough!! Any good reading material you can suggest?

 

[CarlB]

Those vlax functions are actually part of "Visual Lisp".
Good place to start (& maybe all you'll need) is

http://www.afralisp.net/