(vlax-curve-getDistAtPoint ename point)
The vlax-curve-getDistAtPoint function finds the distance between the start point of the specified entity and a specified point on the entity.
ename specifies an entity to be measured.
point specifies a point on the entity provided as a list of three floating-point numbers representing the WCS coordinates of that point.
The function returns the measured distance as floating-point number. If the function fails, it returns nil.
Examples
Assume the most recently drawn entity is an arc starting at 0,0, passing through 1,1, and ending at 2,0:
: (setq en (entlast))
<EName: 045d4b64>
: (setq pt (list 1 1))
(1 1)
: (vlax-curve-getDistAtPoint en pt)
1.5708