Good tips.
Another idea I have is to simplyfy draw a arc tagential between 2 lines and one known arc point. Have anybody a idea to can do it via Autolisp.
I think so here:
1) calculate angle a1 from line1 = 142grad
calculate angle a2 from lin2 = 146grad
so I get angle a3 = 360grad - a1 - a2 = 72grad
and circle angle a4 = 180 - a3 = 108grad
The problem now is how can I get radius or centerpoint from arc?
(defun sel (/
;;; l1
;;; l2
;;; p1
;;; p2
;;; p3
;;; p4
;;; p5
)
(if (not c:cal)(arxload "geomcal"))
(while
(not
(and
(setq l1 (car (entsel "\nSelect line 1! "))
l2 (car (entsel "\nSelect line 2! "))
p1 (cdr (assoc 10 (entget l1)))
p2 (cdr (assoc 11 (entget l1)))
p3 (getpoint "\nSelect arc point! ")
p4 (cdr (assoc 10 (entget l2)))
p5 (cdr (assoc 11 (entget l2)))
)
)
)
)
)
(defun c:calc (/
;;; a1
;;; a2
;;; a3
;;; a4
)
(sel)
(setq a1 (cal "ang (p1,p2)")
a2 (cal "ang (p4,p5)")
a3 (- 360 a1 a2)
a4 (- 180 a3)
)
)