;Arc dimension    (^v^) XANADU, http://www.xanadu.cz

(defun C:DIMARC ( / pt1 pt2 cen a1 a2 D1 D2 D i p r oldOs oldCmde)
 (setq oldCmde (getvar "CMDECHO"))
 (setq oldOs (getvar "OSMODE"))
 (setvar "CMDECHO" 0)
 (prompt "Pick 2 points on an arc - ")
 (setvar "OSMODE" 512)
 (while (not cen)
  (setq	pt1 (getpoint "1st pt: ")
	cen (osnap pt1 "_CEN")
  )
  (if (not cen) (alert "Doesn't lay on an arc, retry")
		(setq pt2 (getpoint cen " 2nd pt: ")))
 );while

 (setvar "OSMODE" 0)
 (setq a1 (angle cen pt1) a2 (angle cen pt2) ad (abs (- a2 a1))
	r (distance pt1 cen)
	D1 (* r ad)
	D2 (* r (- (* 2 pi) ad))
 )
 (prompt (strcat "\nDIMARC> Arc length (1): " (rtos D1) ", complementar arc (2): " (rtos D2))) 

 (setq D D1)
 (initget "1 2 Smaller")
 (setq i (getkword "\nDIMARC> Dim which? [<1>/2/Smaller]: "))
 (if (= i "2")(setq D D2))
 (if (= i "Smaller")(setq D (min D1 D2)))
 (command "_DIMANGULAR" "" cen pt1 pt2 "_T" (rtos D) pause)

 (setvar "OSMODE" oldOs)
 (setvar "CMDECHO" oldCmde)
 (prin1)
)

(princ "\nDIMARC command loaded.")
(princ)