LWPolyline group codes

[buncobob]

I’ve created a monster! I wrote a routine that adds up Arc and Line lengths, and more recently added LWPolyline lengths without the bulges.
AutoCAD seems to have no problem calculating LWPolyline lengths, but using the DXF Reference group codes, I can’t tell how to calculate and measure the length of the bulge arcs! The actual length isn’t saved as a group code, or is it?

[lpseifert]

returns the length of a polyline ( or line, arc, spline...) with or without bulges

(vl-load-com)
(setq obj (vlax-ename->vla-object (car (entsel "Select entity: "))))
(if (vlax-property-available-p obj 'Length)
  (setq len (vlax-get obj 'Length))
  (princ "Entity has no Length property")
  )

[buncobob]

Thanks!!! Mega-reps!

[alanjt]

vla-get-length is limited, but you can use the vlax-curve* to get the length of any curve.
Here's a version that will allow you to take it from anything and you don't have to convert it to a vla-object.

(defun _length (ent)
  ((lambda (e)
     (if (not (vl-catch-all-error-p e))
       (vlax-curve-getDistAtParam ent e)
     )
   )
    (vl-catch-all-apply (function vlax-curve-getEndParam) (list ent))
  )
)

The error checking isn't required, it's just an example. I would never try an extract a property from something if it wasn't available (like trying to get the length of a block).
This is really all you need and it works on enames and vla-objects.

(vlax-curve-getDistAtParam ent (vlax-curve-getEndParam ent))