I suggest to continue entertainment with geometry.
The task:
There is a polyline (for simplicity without arc segments).
It is necessary to find all points along a polyline which of 1 mm along a contour are on distance.
Example:
lwpolyline 0,0 2,0 2,1 01
(defun test (ename)
....................
)
(test (car (entsel "\n Select lwpolyline")))
return
' ((0 0) (1 0) (2 0) (2 1) (1 1) (0 1))
PS. It is possible to think up a large quantity of algorithms, but I offer, at once to estimate job with long polylines, for example length 10000 mm or bigger
PS. If you cannot understand the task - ask, I will try to explain in more details!