;=====================================================================
;    Auto lisp...Double circle center line 
;  (c) Jeong, yong-sik   June 1994
;=====================================================================
(defun clerr (s)
   (if (/= s "Function cancelled")   ; If an error (such as CTRL-C) occurs
      (princ (strcat "nError: " s)) ; while this command is active...
   );;if
   (setvar "CLAYER" clay)
   (setvar "CMDECHO" scmde)
   (setq *error* olderr)             ; Restore old *error* handler
   (princ)
);;defune
;------------------------------------------------------------
(defun C:DC (/ olderr clay sblip scmde sgrid shl sucsf ts xx)   ;program name
   (setq olderr  *error*
         *error* clerr)
   (setq scmde (getvar "CMDECHO"))
   (setq clay  (getvar "CLAYER"))
   (setq os  (getvar "OSMODE"))
   (setvar "CMDECHO" 0)
   (setvar "CMDECHO" 0)
   (setvar "OSMODE" 4)
   (setq pt1 (getpoint "n≫ Select 1st circle : "))
   (setq pt2 (getpoint pt1 "n≫ Select 2nd circle : "))
   (setq c (angle pt1 pt2))
   (setvar "OSMODE" 0)
   (setq b (getdist pt1 "n≫ Extansion Length ?: "))
   (command "LAYER" "m" "22" "") ;>>중심선 레이어 22 (사용자 변경 부분)
;---------------------------------------------------------------------
   (setq p1 (polar pt1 (+ (* pi 1.0) c) b))
   (setq p2 (polar pt2 (+ (/ 0 1.0) c) b))
   (setq p3 (polar pt1 (+ (/ pi 2.0) c) b))
   (setq p4 (polar pt1 (+ (* pi 1.5) c) b))
   (setq p5 (polar pt2 (+ (/ pi 2.0) c) b))
   (setq p6 (polar pt2 (+ (* pi 1.5) c) b))
;---------------------------------------------------------
   (command "LINE" p1 p2 "")
   (command "LINE" p3 p4 "")
   (command "LINE" p5 p6 "")
   (setvar "CMDECHO" scmde)
   (setvar "CLAYER" clay)
   (setvar "OSMODE" os) 
   (setq *error* olderr)   ; Restore old *error* handler
   (princ)
);;end of defune