;----------------------------------------------------------------------------
;                             DOFF.LSP
;         Offset a line from Picked Line equally each side
;           Copyright: TOWNSCAPE SUPPORT SYSTEMS - 1989
;----------------------------------------------------------------------------
(setq oldwidth 6)
; Degrees to Radians conversion.

(defun dtr(a)
(* pi (/ a 180.0)))
;----------------------------------------------------------------------------

; MAIN CALLING FUNCTION

;----------------------------------------------------------------------------
(defun c:DOFF()
(setq olderr *error* *error* myerr)
(setvar "cmdecho" 0)
(setq ang90 (dtr 90))
;----------------------------------------------------------------------------
;get new offset distance or accept default.

(setq width (getdist (strcat "\nEnter width of finished offsets: <" (rtos oldwidth) ">")))
(if (= width nil) (setq width oldwidth) (setq oldwidth width))
(setq width (/ width 2))
;----------------------------------------------------------------------------
;start a loop for successive calls to main program.

(while
(setq ent (entsel "\nSelect line: "))
(setq elist (entget (car ent)))
(setq angent (angle (cdr (assoc 11 elist)) (cdr (assoc 10 elist))))
;----------------------------------------------------------------------------
;do calculations for offsetting lines.

(setq pt1 (cadr ent))
(setq ang1 (+ angent ang90))
(setq ang2 (- angent ang90))
(setq dir1 (polar pt1 ang1 width))
(setq dir2 (polar pt1 ang2 width))
;----------------------------------------------------------------------------
;do the offsetting and erase original line.

(command "offset" width ent dir1 ent dir2 "")
(setvar "cmdecho" 1)
)
;----------------------------------------------------------------------------
;end of the while loop for successive calls to main function
;----------------------------------------------------------------------------
)
;----------------------------------------------------------------------------
;end of DOFF.LSP