How do I calculate the closest point on an arc to a selected point?

Is the most efficient to do this to test every point on the arc in a loop?

Or is there a better way?

Thanks for any and all input

Andrew

Look into vlax-curve-getClosestPointto

Look into vlax-curve-getClosestPointto

Thanks! I figured making a brute force loop wouldn't be the best way

As an example:

(defun c:test (/ pt ent cLs)
 (vl-load-com)

 (if (and (setq ent (car (entsel "\nSelect an Object: ")))
          (setq pt (getpoint "\nSelect a Point to Test: ")))
   (progn

     (setq cLs (vlax-curve-getClosestPointto ent pt))


     ;; --  Display Point  --

     (setvar "PDMODE" 34)
     (vla-addPoint
       (vla-get-ModelSpace
         (vla-get-ActiveDocument
           (vlax-get-acad-object)))
       (vlax-3D-point cLs))))  

 (princ))
       

Look into vlax-curve-getClosestPointto

What is VLAX? Is this a Cad command name?

If memory serves VLAX specifies a Visual LISP ActiveX function prefix. ... It (my memory) didn't. See next post.

** Edit - Just wanted to get my guess in before Lee's (correct) answer. LoL

Aha... Found it!

Lee's post here clarifies the different function prefixes that Visual LISP uses.

Aha... Found it!

 

Lee's post here clarifies the different function prefixes that Visual LISP uses.

Thanks. They are far beyond my knowledge and I don't think I can use them.

Thanks. They are far beyond my knowledge and I don't think I can use them.

Not at all... It may just take some time to understand how they work, and how to properly use them.

Have you tried Lee's code in post #4?

Have you tried Lee's code in post #4?

at my old coding style...