; The Codewriting Workbook
; Creating Computational Architecture in AutoLISP
; by Robert J. Krawczyk
; Princeton Architectural Press, 2008
; --------------------------------------------------------------------------
; CH05A.LSP
; --------------------------------------------------------------------------
; Disclaimer: The information contained in this file is distributed on an
; "as is" basis, without warranty.  Although every precaution has been taken
; in the preparation of this work, the author and publisher shall not have 
; any liability to any person or entity with respect to any loss or damage
; caused or alleged to be caused directly or indirectly by the information
; contained in this work.
; --------------------------------------------------------------------------
(defun dtr (a) (* pi (/ a 180.0)))
(defun rtd (a) (/ (* a 180.0) pi))
(defun tan (a) (/ (sin a) (cos a)))
; --------------------------------------------------------------------------
;---------------------------------------------------------------------------
; VT - top view
(defun c:vt ()     
  (command "vpoint" "r" 270 90)
  (command "zoom" "e" "ucs" "v" "zoom" ".9x")
  (princ)
)
; VL - left view
(defun c:vl ()     
  (command "vpoint" "r" 180 0)
  (command "zoom" "e" "ucs" "v" "zoom" ".9x")
  (princ)
)
; VR - right view
(defun c:vr ()     
  (command "vpoint" "r" 0 0)
  (command "zoom" "e" "ucs" "v" "zoom" ".9x")
  (princ)
)
; VF - front view
(defun c:vf ()     
  (command "vpoint" "r" 270 0)
  (command "zoom" "e" "ucs" "v" "zoom" ".9x")
  (princ)
)
; VB - back view
(defun c:vb ()     
  (command "vpoint" "r" 90 0)
  (command "zoom" "e" "ucs" "v" "zoom" ".9x")
  (princ)
)
; VSW - SW view
(defun c:vsw ()     
  (command "vpoint" "r" 270 90)
  (command "ucs" "v")
  (command "vpoint" "r" 225 45)
  (command "zoom" "e" "zoom" ".9x")
  (princ)
)
; VSE - SE view
(defun c:vse ()     
  (command "vpoint" "r" 270 90)
  (command "ucs" "v")
  (command "vpoint" "r" 315 45)
  (command "zoom" "e" "zoom" ".9x")
  (princ)
)
; VNE - NE view
(defun c:vne ()     
  (command "vpoint" "r" 270 90)
  (command "ucs" "v")
  (command "vpoint" "r" 45 45)
  (command "zoom" "e" "zoom" ".9x")
  (princ)
)
; VNW - NW view
(defun c:vnw ()     
  (command "vpoint" "r" 270 90)
  (command "ucs" "v")
  (command "vpoint" "r" 135 45)
  (command "zoom" "e" "zoom" ".9x")
  (princ)
)
;---------------------------------------------------------------------------
(defun prog01 ()
 (graphscr)
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 ; get boundary points and parameters
 (prompt "\nPROG01:")
 (setq spnt (getpoint "\nPick start point:"))
 (setq cpnt (getcorner spnt "\nPick end point:"))
 (setq numtimes (getint "\nEnter number of lines:"))
 ; compute line length, width of boundary
 (setq linelen (- (nth 1 cpnt) (nth 1 spnt)))
 ; compute increment across boundary
 (setq xinc (/ (- (nth 0 cpnt) (nth 0 spnt)) (- numtimes 1)))
 ; set first point and first x coord
 (setq xpnt spnt)
 (setq xpt (nth 0 spnt))
 ; loop to repeat lines
 (repeat numtimes
   ; compute endpoint
   (setq epnt (polar xpnt (dtr 90) linelen))
   ; draw line
   (command ".LINE" xpnt epnt "")
   ; inc x coord
   (setq xpt (+ xpt xinc))
   (setq xpnt (list xpt (nth 1 xpnt) (nth 2 xpnt)))
 )
 (princ)
)
; --------------------------------------------------------------------------
(defun prog02 ()
 (graphscr)
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 ; get boundary points and parameters
 (prompt "\nPROG02:")
 (setq spnt (getpoint "\nPick start point:"))
 (setq cpnt (getcorner spnt "\nPick end point:"))
 (setq zheight (getdist spnt "\nEnter Height:"))
 (setq numtimes (getint "\nEnter number of lines:"))
 ; compute line length, width of boundary
 (setq linelen (- (nth 1 cpnt) (nth 1 spnt)))
 ; compute increment across boundary
 (setq xinc (/ (- (nth 0 cpnt) (nth 0 spnt)) (- numtimes 1)))
 ; set first point and first x coord
 (setq xpnt spnt)
 (setq xpt (nth 0 spnt))
 ; loop to repeat lines
 (repeat numtimes
   ; compute endpoint
   (setq epnt (polar xpnt (dtr 90) linelen))
   ; set extrude height
   (command ".ELEV" 0.0 zheight)
   ; draw line
   (command ".LINE" xpnt epnt "")
   ; inc x coord
   (setq xpt (+ xpt xinc))
   (setq xpnt (list xpt (nth 1 xpnt) (nth 2 xpnt)))
 )
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 (princ)
)
; --------------------------------------------------------------------------
(defun prog03 ()
 (graphscr)
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 ; get boundary points and parameters
 (prompt "\nPROG03:")
 (setq spnt (getpoint "\nPick start point:"))
 (setq cpnt (getcorner spnt "\nPick end point:"))
 (setq zheight (getdist spnt "\nEnter Height:"))
 (setq numtimes (getint "\nEnter number of lines:"))
 ; compute line length, width of boundary
 (setq linelen (- (nth 1 cpnt) (nth 1 spnt)))
 ; compute increment across boundary
 (setq xinc (/ (- (nth 0 cpnt) (nth 0 spnt)) (- numtimes 1)))
 ; computer ang inc
 (setq anginc (/ 360.0 (- numtimes 1)))
 ; set first point and first x coord
 (setq xpnt spnt)
 (setq xpt (nth 0 spnt))
 ; start ang
 (setq ang 0)
 ; loop to repeat lines
 (repeat numtimes
   ; compute line length
   (setq newlinelen (* linelen (sin (dtr ang))))
   ; compute endpoint
   (setq epnt (polar xpnt (dtr 90) newlinelen))
   ; set extrude height
   (command ".ELEV" 0.0 zheight)
   ; draw line
   (command ".LINE" xpnt epnt "")
   ; inc x coord
   (setq xpt (+ xpt xinc))
   (setq xpnt (list xpt (nth 1 xpnt) (nth 2 xpnt)))
   ; inc ang
   (setq ang (+ ang anginc))
 )
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 (princ)
)
; --------------------------------------------------------------------------
(defun prog04 ()
 (graphscr)
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 ; get boundary points and parameters
 (prompt "\nPROG04:")
 (setq spnt (getpoint "\nPick start point:"))
 (setq cpnt (getcorner spnt "\nPick end point:"))
 (setq zheight (getdist spnt "\nEnter Height:"))
 (setq numtimes (getint "\nEnter number of lines:"))
 ; compute line length, width of boundary
 (setq linelen (- (nth 1 cpnt) (nth 1 spnt)))
 ; compute increment across boundary
 (setq xinc (/ (- (nth 0 cpnt) (nth 0 spnt)) (- numtimes 1)))
 ; computer ang inc
 (setq anginc (/ 360.0 (- numtimes 1)))
 ; set first point and first x coord
 (setq xpnt spnt)
 (setq xpt (nth 0 spnt))
 ; start ang
 (setq ang 0)
 ; loop to repeat lines
 (repeat numtimes
   ; compute line length
   (setq newlinelen (* linelen (cos (dtr ang))))
   ; compute endpoint
   (setq epnt (polar xpnt (dtr 90) newlinelen))
   ; set extrude height
   (command ".ELEV" 0.0 zheight)
   ; draw line
   (command ".LINE" xpnt epnt "")
   ; inc x coord
   (setq xpt (+ xpt xinc))
   (setq xpnt (list xpt (nth 1 xpnt) (nth 2 xpnt)))
   ; inc ang
   (setq ang (+ ang anginc))
 )
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 (princ)
)
; --------------------------------------------------------------------------
(defun prog05 ()
 (graphscr)
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 ; get boundary points and parameters
 (prompt "\nPROG05:")
 (setq spnt (getpoint "\nPick start point:"))
 (setq cpnt (getcorner spnt "\nPick end point:"))
 (setq zheight (getdist spnt "\nEnter Height:"))
 (setq numtimes (getint "\nEnter number of lines:"))
 ; compute line length, width of boundary
 (setq linelen (- (nth 1 cpnt) (nth 1 spnt)))
 ; compute increment across boundary
 (setq xinc (/ (- (nth 0 cpnt) (nth 0 spnt)) (- numtimes 1)))
 ; computer ang inc
 (setq anginc (/ 360.0 (- numtimes 1)))
 ; set first point and first x coord
 (setq xpnt spnt)
 (setq xpt (nth 0 spnt))
 ; start ang
 (setq ang 0)
 ; loop to repeat lines
 (repeat numtimes
   ; compute line length
   (setq newlinelen (* linelen (abs (cos (dtr ang)))))
   ; compute endpoint
   (setq epnt (polar xpnt (dtr 90) newlinelen))
   ; set extrude height
   (command ".ELEV" 0.0 zheight)
   ; draw line
   (command ".LINE" xpnt epnt "")
   ; inc x coord
   (setq xpt (+ xpt xinc))
   (setq xpnt (list xpt (nth 1 xpnt) (nth 2 xpnt)))
   ; inc ang
   (setq ang (+ ang anginc))
 )
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 (princ)
)
; --------------------------------------------------------------------------
(defun prog06 ()
 (graphscr)
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 ; get boundary points and parameters
 (prompt "\nPROG06:")
 (setq spnt (getpoint "\nPick start point:"))
 (setq cpnt (getcorner spnt "\nPick end point:"))
 (setq zheight (getdist spnt "\nEnter Height:"))
 (setq numtimes (getint "\nEnter number of lines:"))
 (setq linefact (getreal "\nEnter keep line factor:")) 
 ; compute line length, width of boundary
 (setq linelen (- (nth 1 cpnt) (nth 1 spnt)))
 ; compute increment across boundary
 (setq xinc (/ (- (nth 0 cpnt) (nth 0 spnt)) (- numtimes 1)))
 ; computer ang inc
 (setq anginc (/ 360.0 (- numtimes 1)))
 ; set first point and first x coord
 (setq xpnt spnt)
 (setq xpt (nth 0 spnt))
 ; start ang
 (setq ang 0)
 ; loop to repeat lines
 (repeat numtimes
   ; compute line length
   (setq linepart1 (* linelen linefact)) 
   (setq linepart2 (* (* linelen (- 1.0 linefact)) (abs (cos (dtr ang)))))
   (setq newlinelen (+ linepart1 linepart2))
   ; compute endpoint
   (setq epnt (polar xpnt (dtr 90) newlinelen))
   ; set extrude height
   (command ".ELEV" 0.0 zheight)
   ; draw line
   (command ".LINE" xpnt epnt "")
   ; inc x coord
   (setq xpt (+ xpt xinc))
   (setq xpnt (list xpt (nth 1 xpnt) (nth 2 xpnt)))
   ; inc ang
   (setq ang (+ ang anginc))
 )
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 (princ)
)
; --------------------------------------------------------------------------
(defun prog07 ()
 (graphscr)
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 ; get boundary points and parameters
 (prompt "\nPROG07:")
 (setq spnt (getpoint "\nPick start point:"))
 (setq cpnt (getcorner spnt "\nPick end point:"))
 (setq zheight (getdist spnt "\nEnter Height:"))
 (setq numtimes (getint "\nEnter number of lines:"))
 (setq linefact (getreal "\nEnter keep line factor:")) 
 (setq numcycles (getreal "\nNumber of curve cycles:"))
 ; compute line length, width of boundary
 (setq linelen (- (nth 1 cpnt) (nth 1 spnt)))
 ; compute increment across boundary
 (setq xinc (/ (- (nth 0 cpnt) (nth 0 spnt)) (- numtimes 1)))
 ; computer ang inc
 (setq anginc (/ (* 360.0 numcycles) (- numtimes 1)))
 ; set first point and first x coord
 (setq xpnt spnt)
 (setq xpt (nth 0 spnt))
 ; start ang
 (setq ang 0)
 ; loop to repeat lines
 (repeat numtimes
   ; compute line length
   (setq linepart1 (* linelen linefact)) 
   (setq linepart2 (* (* linelen (- 1.0 linefact)) (abs (cos (dtr ang)))))
   (setq newlinelen (+ linepart1 linepart2))
   ; compute endpoint
   (setq epnt (polar xpnt (dtr 90) newlinelen))
   ; set extrude height
   (command ".ELEV" 0.0 zheight)
   ; draw line
   (command ".LINE" xpnt epnt "")
   ; inc x coord
   (setq xpt (+ xpt xinc))
   (setq xpnt (list xpt (nth 1 xpnt) (nth 2 xpnt)))
   ; inc ang
   (setq ang (+ ang anginc))
 )
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 (princ)
)
; --------------------------------------------------------------------------
(defun prog08 ()
 (graphscr)
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 ; get boundary points and parameters
 (prompt "\nPROG08:")
 (setq spnt (getpoint "\nPick start point:"))
 (setq cpnt (getcorner spnt "\nPick end point:"))
 (setq zheight (getdist spnt "\nEnter Height:"))
 (setq numtimes (getint "\nEnter number of lines:"))
 (setq linefact (getreal "\nEnter keep line factor:")) 
 (setq numcycles (getreal "\nNumber of curve cycles:"))
 ; compute line length, width of boundary
 (setq linelen (- (nth 1 cpnt) (nth 1 spnt)))
 ; compute increment across boundary
 (setq xinc (/ (- (nth 0 cpnt) (nth 0 spnt)) (- numtimes 1)))
 ; computer ang inc
 (setq anginc (/ (* 360.0 numcycles) (- numtimes 1)))
 ; set first point and first x coord
 (setq xpnt spnt)
 (setq xpt (nth 0 spnt))
 ; start ang
 (setq ang 0)
 ; loop to repeat lines
 (repeat numtimes
   ; compute line length
   (setq linepart1 (* linelen linefact)) 
   (setq linepart2 (* (* linelen (- 1.0 linefact)) (abs (cos (dtr ang)))))
   (setq newlinelen (+ linepart1 linepart2))
   ; compute endpoint
   (setq epnt (polar xpnt (dtr 90) newlinelen))
   ; compute height
   (setq linepart1 (* zheight linefact)) 
   (setq linepart2 (* (* zheight (- 1.0 linefact)) (abs (cos (dtr ang)))))
   (setq newzheight (+ linepart1 linepart2))
   ; set extrude height
   (command ".ELEV" 0.0 newzheight)
   ; draw line
   (command ".LINE" xpnt epnt "")
   ; inc x coord
   (setq xpt (+ xpt xinc))
   (setq xpnt (list xpt (nth 1 xpnt) (nth 2 xpnt)))
   ; inc ang
   (setq ang (+ ang anginc))
 )
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 (princ)
)
; --------------------------------------------------------------------------
(defun prog09 ()
 (graphscr)
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 ; get boundary points and parameters
 (prompt "\nPROG09:")
 (setq spnt (getpoint "\nPick start point:"))
 (setq cpnt (getcorner spnt "\nPick end point:"))
 (setq zheight (getdist spnt "\nEnter Height:"))
 (setq numtimes (getint "\nEnter number of lines:"))
 (setq linefact (getreal "\nEnter keep line factor:")) 
 (setq numcycles (getreal "\nNumber of curve cycles:"))
 ; compute line length, width of boundary
 (setq linelen (- (nth 1 cpnt) (nth 1 spnt)))
 ; compute increment across boundary
 (setq xinc (/ (- (nth 0 cpnt) (nth 0 spnt)) (- numtimes 1)))
 ; computer ang inc
 (setq anginc (/ (* 360.0 numcycles) (- numtimes 1)))
 ; set first point and first x coord
 (setq xpnt spnt)
 (setq xpt (nth 0 spnt))
 ; start ang
 (setq ang 0)
 ; loop to repeat lines
 (repeat numtimes
   ; compute line length
   (setq linepart1 (* linelen linefact)) 
   (setq linepart2 (* (* linelen (- 1.0 linefact)) (abs (cos (dtr ang)))))
   (setq newlinelen (+ linepart1 linepart2))
   ; compute endpoint
   (setq epnt1 (polar xpnt (dtr 90) newlinelen))
   (setq epnt2 (polar xpnt (dtr 270) newlinelen))
   ; compute height
   (setq linepart1 (* zheight linefact)) 
   (setq linepart2 (* (* zheight (- 1.0 linefact)) (abs (cos (dtr ang)))))
   (setq newzheight (+ linepart1 linepart2))
   ; set extrude height
   (command ".ELEV" 0.0 newzheight)
   ; draw line
   (command ".LINE" xpnt epnt1 "")
   (command ".LINE" xpnt epnt2 "")
   ; inc x coord
   (setq xpt (+ xpt xinc))
   (setq xpnt (list xpt (nth 1 xpnt) (nth 2 xpnt)))
   ; inc ang
   (setq ang (+ ang anginc))
 )
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 (princ)
)
; --------------------------------------------------------------------------
(defun prog10 ()
 (graphscr)
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 ; get boundary points and parameters
 (prompt "\nPROG10:")
 (setq spnt (getpoint "\nPick start point:"))
 (setq cpnt (getcorner spnt "\nPick end point:"))
 (setq zheight (getdist spnt "\nEnter Height:"))
 (setq numtimes (getint "\nEnter number of lines:"))
 (setq linefact (getreal "\nEnter keep line factor:")) 
 (setq numcycles (getreal "\nNumber of curve cycles:"))
 ; compute line length, width of boundary
 (setq linelen (- (nth 1 cpnt) (nth 1 spnt)))
 ; compute increment across boundary
 (setq xinc (/ (- (nth 0 cpnt) (nth 0 spnt)) (- numtimes 1)))
 ; computer ang inc
 (setq anginc (/ (* 360.0 numcycles) (- numtimes 1)))
 ; set first point and first x coord
 (setq xpnt spnt)
 (setq xpt (nth 0 spnt))
 ; start ang
 (setq ang 0)
 ; loop to repeat lines
 (repeat numtimes
   ; compute line length
   (setq linepart1 (* linelen linefact)) 
   (setq linepart2 (* (* linelen (- 1.0 linefact)) (abs (cos (dtr ang)))))
   (setq newlinelen (+ linepart1 linepart2))
   ; compute endpoint
   (setq epnt1 (polar xpnt (dtr 90) newlinelen))
   (setq epnt2 (polar xpnt (dtr 270) newlinelen))
   ; compute height
   (setq linepart1 (* zheight linefact)) 
   (setq linepart2 (* (* zheight (- 1.0 linefact)) (abs (sin (dtr ang)))))
   (setq newzheight (+ linepart1 linepart2))
   ; set extrude height
   (command ".ELEV" 0.0 newzheight)
   ; draw line
   (command ".LINE" xpnt epnt1 "")
   (command ".LINE" xpnt epnt2 "")
   ; inc x coord
   (setq xpt (+ xpt xinc))
   (setq xpnt (list xpt (nth 1 xpnt) (nth 2 xpnt)))
   ; inc ang
   (setq ang (+ ang anginc))
 )
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 (princ)
)
; --------------------------------------------------------------------------
(defun prog11 ()
 (graphscr)
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 ; get boundary points and parameters
 (prompt "\nPROG11:")
 (setq spnt (getpoint "\nPick start point:"))
 (setq cpnt (getcorner spnt "\nPick end point:"))
 (setq zheight (getdist spnt "\nEnter Height:"))
 (setq numtimes (getint "\nEnter number of lines:"))
 (setq linefact (getreal "\nEnter keep line factor:")) 
 (setq numcycles (getreal "\nNumber of curve cycles:"))
 ; compute line length, width of boundary
 (setq linelen (- (nth 1 cpnt) (nth 1 spnt)))
 ; compute increment across boundary
 (setq xinc (/ (- (nth 0 cpnt) (nth 0 spnt)) (- numtimes 1)))
 ; computer ang inc
 (setq anginc (/ (* 360.0 numcycles) (- numtimes 1)))
 ; set first point and first x coord
 (setq xpnt spnt)
 (setq xpt (nth 0 spnt))
 ; start ang
 (setq ang 0)
 ; loop to repeat lines
 (repeat numtimes
   ; compute line length
   (setq linepart1 (* linelen linefact)) 
   (setq linepart2 (* (* linelen (- 1.0 linefact)) (abs (sin (dtr ang)))))
   (setq newlinelen (+ linepart1 linepart2))
   ; compute endpoint
   (setq epnt1 (polar xpnt (dtr 90) newlinelen))
   (setq epnt2 (polar xpnt (dtr 270) newlinelen))
   ; compute height
   (setq linepart1 (* zheight linefact)) 
   (setq linepart2 (* (* zheight (- 1.0 linefact)) (abs (cos (dtr ang)))))
   (setq newzheight (+ linepart1 linepart2))
   ; set extrude height
   (command ".ELEV" 0.0 newzheight)
   ; draw line
   (command ".LINE" xpnt epnt1 "")
   (command ".LINE" xpnt epnt2 "")
   ; inc x coord
   (setq xpt (+ xpt xinc))
   (setq xpnt (list xpt (nth 1 xpnt) (nth 2 xpnt)))
   ; inc ang
   (setq ang (+ ang anginc))
 )
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 (princ)
)
; --------------------------------------------------------------------------
(defun prog12 ()
 (graphscr)
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 ; get boundary points and parameters
 (prompt "\nPROG12:")
 (setq spnt (getpoint "\nPick start point:"))
 (setq cpnt (getcorner spnt "\nPick end point:"))
 (setq zheight (getdist spnt "\nEnter Height:"))
 (setq numtimes (getint "\nEnter number of lines:"))
 (setq linefact (getreal "\nEnter keep line factor:")) 
 (setq numcycles (getreal "\nNumber of curve cycles:"))
 ; compute line length, width of boundary
 (setq linelen (- (nth 1 cpnt) (nth 1 spnt)))
 ; compute increment across boundary
 (setq xinc (/ (- (nth 0 cpnt) (nth 0 spnt)) (- numtimes 1)))
 ; computer ang inc
 (setq anginc (/ (* 360.0 numcycles) (- numtimes 1)))
 ; set first point and first x coord
 (setq xpnt spnt)
 (setq xpt (nth 0 spnt))
 ; start ang
 (setq ang 0)
 ; loop to repeat lines
 (repeat numtimes
   ; compute line length
   (setq linepart1 (* linelen linefact)) 
   (setq linepart2 (* (* linelen (- 1.0 linefact)) (abs (sin (dtr ang)))))
   (setq newlinelen (+ linepart1 linepart2))
   ; compute endpoint
   (setq epnt1 (polar xpnt (dtr 90) newlinelen))
   (setq epnt2 (polar xpnt (dtr 270) newlinelen))
   ; compute height
   (setq linepart1 (* zheight linefact)) 
   (setq linepart2 (* (* zheight (- 1.0 linefact)) (abs (cos (dtr ang)))))
   (setq newzheight (+ linepart1 linepart2))
   ; compute frame points
   (setq pnt1 epnt2)   
   (setq pnt2 (list (nth 0 epnt2) (nth 1 epnt2) (+ (nth 2 epnt2) newzheight)))   
   (setq pnt3 (list (nth 0 xpnt) (nth 1 xpnt) (+ (nth 2 xpnt) newzheight)))   
   (setq pnt4 (list (nth 0 epnt1) (nth 1 epnt1) (+ (nth 2 epnt1) newzheight)))   
   (setq pnt5 epnt1)   
   ; draw 3DPOLY
   (command ".3DPOLY" pnt1 pnt2 pnt3 pnt4 pnt5 "")
   ; inc x coord
   (setq xpt (+ xpt xinc))
   (setq xpnt (list xpt (nth 1 xpnt) (nth 2 xpnt)))
   ; inc ang
   (setq ang (+ ang anginc))
 )
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 (princ)
)
; --------------------------------------------------------------------------
(defun prog13 ()
 (graphscr)
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 ; get boundary points and parameters
 (prompt "\nPROG13:")
 (setq spnt (getpoint "\nPick start point:"))
 (setq cpnt (getcorner spnt "\nPick end point:"))
 (setq zheight (getdist spnt "\nEnter Height:"))
 (setq numtimes (getint "\nEnter number of lines:"))
 (setq linefact (getreal "\nEnter keep line factor:")) 
 (setq numcycles (getreal "\nNumber of curve cycles:"))
 ; compute line length, width of boundary
 (setq linelen (- (nth 1 cpnt) (nth 1 spnt)))
 ; compute increment across boundary
 (setq xinc (/ (- (nth 0 cpnt) (nth 0 spnt)) (- numtimes 1)))
 ; computer ang inc
 (setq anginc (/ (* 360.0 numcycles) (- numtimes 1)))
 ; set first point and first x coord
 (setq xpnt spnt)
 (setq xpt (nth 0 spnt))
 ; start ang
 (setq ang 0)
 ; loop to repeat lines
 (repeat numtimes
   ; compute line length
   (setq linepart1 (* linelen linefact)) 
   (setq linepart2 (* (* linelen (- 1.0 linefact)) (abs (sin (dtr ang)))))
   (setq newlinelen (+ linepart1 linepart2))
   ; compute endpoint
   (setq epnt1 (polar xpnt (dtr 90) newlinelen))
   (setq epnt2 (polar xpnt (dtr 270) newlinelen))
   ; compute edge height
   (setq linepart1 (* zheight linefact)) 
   (setq linepart2 (* (* zheight (- 1.0 linefact)) (abs (cos (dtr ang)))))
   (setq newzheight (+ linepart1 linepart2))
   ; compute midpoint height
   (setq linepart1 (* zheight linefact)) 
   (setq linepart2 (* (* zheight (- 1.0 linefact)) (abs (sin (dtr ang)))))
   (setq newmidzheight (+ linepart1 linepart2))
   ; compute frame points
   (setq pnt1 epnt2)   
   (setq pnt2 (list (nth 0 epnt2) (nth 1 epnt2) (+ (nth 2 epnt2) newzheight)))   
   (setq pnt3 (list (nth 0 xpnt) (nth 1 xpnt) (+ (nth 2 xpnt) newmidzheight)))   
   (setq pnt4 (list (nth 0 epnt1) (nth 1 epnt1) (+ (nth 2 epnt1) newzheight)))   
   (setq pnt5 epnt1)   
   ; draw 3DPOLY
   (command ".3DPOLY" pnt1 pnt2 pnt3 pnt4 pnt5 "")
   ; inc x coord
   (setq xpt (+ xpt xinc))
   (setq xpnt (list xpt (nth 1 xpnt) (nth 2 xpnt)))
   ; inc ang
   (setq ang (+ ang anginc))
 )
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 (princ)
)
; --------------------------------------------------------------------------
(defun prog14 ()
 (graphscr)
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 ; get boundary points and parameters
 (prompt "\nPROG14:")
 (setq spnt (getpoint "\nPick start point:"))
 (setq cpnt (getcorner spnt "\nPick end point:"))
 (setq zedge (getdist spnt "\nEnter edge height:"))
 (setq zmid  (getdist spnt "\nEnter midpoint height:"))
 (setq numtimes (getint "\nEnter number of lines:"))
 (setq linefact (getreal "\nEnter keep line factor:")) 
 (setq numcycles (getreal "\nNumber of curve cycles:"))
 ; compute line length, width of boundary
 (setq linelen (- (nth 1 cpnt) (nth 1 spnt)))
 ; compute increment across boundary
 (setq xinc (/ (- (nth 0 cpnt) (nth 0 spnt)) (- numtimes 1)))
 ; computer ang inc
 (setq anginc (/ (* 360.0 numcycles) (- numtimes 1)))
 ; set first point and first x coord
 (setq xpnt spnt)
 (setq xpt (nth 0 spnt))
 ; start ang
 (setq ang 0)
 ; loop to repeat lines
 (repeat numtimes
   ; compute line length
   (setq linepart1 (* linelen linefact)) 
   (setq linepart2 (* (* linelen (- 1.0 linefact)) (abs (sin (dtr ang)))))
   (setq newlinelen (+ linepart1 linepart2))
   ; compute endpoint
   (setq epnt1 (polar xpnt (dtr 90) newlinelen))
   (setq epnt2 (polar xpnt (dtr 270) newlinelen))
   ; compute edge height
   (setq linepart1 (* zedge linefact)) 
   (setq linepart2 (* (* zedge (- 1.0 linefact)) (abs (cos (dtr ang)))))
   (setq newzedge (+ linepart1 linepart2))
   ; compute midpoint height
   (setq linepart1 (* zmid linefact)) 
   (setq linepart2 (* (* zmid (- 1.0 linefact)) (abs (sin (dtr ang)))))
   (setq newzmid (+ linepart1 linepart2))
   ; compute frame points
   (setq pnt1 epnt2)   
   (setq pnt2 (list (nth 0 epnt2) (nth 1 epnt2) (+ (nth 2 epnt2) newzedge)))   
   (setq pnt3 (list (nth 0 xpnt) (nth 1 xpnt) (+ (nth 2 xpnt) newzmid)))   
   (setq pnt4 (list (nth 0 epnt1) (nth 1 epnt1) (+ (nth 2 epnt1) newzedge)))   
   (setq pnt5 epnt1)   
   ; draw 3DPOLY
   (command ".3DPOLY" pnt1 pnt2 pnt3 pnt4 pnt5 "")
   ; inc x coord
   (setq xpt (+ xpt xinc))
   (setq xpnt (list xpt (nth 1 xpnt) (nth 2 xpnt)))
   ; inc ang
   (setq ang (+ ang anginc))
 )
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 (princ)
)
; --------------------------------------------------------------------------
(defun prog15 ()
 (graphscr)
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 ; get boundary points and parameters
 (prompt "\nPROG15:")
 (setq spnt (getpoint "\nPick start point:"))
 (setq cpnt (getcorner spnt "\nPick end point:"))
 (setq zedge (getdist spnt "\nEnter edge height:"))
 (setq zmid  (getdist spnt "\nEnter midpoint height:"))
 (setq numtimes (getint "\nEnter number of lines:"))
 (setq linefact (getreal "\nEnter keep line factor:")) 
 (setq numcycles (getreal "\nNumber of curve cycles:"))
 ; compute line length, width of boundary
 (setq linelen (- (nth 1 cpnt) (nth 1 spnt)))
 ; compute increment across boundary
 (setq xinc (/ (- (nth 0 cpnt) (nth 0 spnt)) (- numtimes 1)))
 ; computer ang inc
 (setq anginc (/ (* 360.0 numcycles) (- numtimes 1)))
 ; set first point and first x coord
 (setq xpnt spnt)
 (setq xpt (nth 0 spnt))
 ; start ang
 (setq ang 0)
 ; loop to repeat lines
 (repeat numtimes
   ; compute line length
   (setq linepart1 (* linelen linefact)) 
   (setq linepart2 (* (* linelen (- 1.0 linefact)) (abs (sin (dtr ang)))))
   (setq newlinelen (+ linepart1 linepart2))
   ; compute endpoint
   (setq epnt1 (polar xpnt (dtr 90) newlinelen))
   (setq epnt2 (polar xpnt (dtr 270) newlinelen))
   ; compute edge height
   (setq linepart1 (* zedge linefact)) 
   (setq linepart2 (* (* zedge (- 1.0 linefact)) (abs (cos (dtr ang)))))
   (setq newzedge (+ linepart1 linepart2))
   ; compute midpoint height
   (setq linepart1 (* zmid linefact)) 
   (setq linepart2 (* (* zmid (- 1.0 linefact)) (abs (sin (dtr ang)))))
   (setq newzmid (+ linepart1 linepart2))
   ; compute frame points
   (setq pnt1 (list (nth 0 xpnt) (- (nth 1 xpnt) linelen) (nth 2 xpnt)))   
   (setq pnt2 (list (nth 0 epnt2) (nth 1 epnt2) (+ (nth 2 epnt2) newzedge)))   
   (setq pnt3 (list (nth 0 xpnt) (nth 1 xpnt) (+ (nth 2 xpnt) newzmid)))   
   (setq pnt4 (list (nth 0 epnt1) (nth 1 epnt1) (+ (nth 2 epnt1) newzedge)))   
   (setq pnt5 (list (nth 0 xpnt) (+ (nth 1 xpnt) linelen) (nth 2 xpnt)))   
   ; draw 3DPOLY
   (command ".3DPOLY" pnt1 pnt2 pnt3 pnt4 pnt5 "")
   ; inc x coord
   (setq xpt (+ xpt xinc))
   (setq xpnt (list xpt (nth 1 xpnt) (nth 2 xpnt)))
   ; inc ang
   (setq ang (+ ang anginc))
 )
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 (princ)
)
; --------------------------------------------------------------------------
(defun prog15a ()
 (graphscr)
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 ; get boundary points and parameters
 (prompt "\nPROG15a:")
 (setq spnt (getpoint "\nPick start point:"))
 (setq cpnt (getcorner spnt "\nPick end point:"))
 (setq zedge (getdist spnt "\nEnter edge height:"))
 (setq zmid  (getdist spnt "\nEnter midpoint height:"))
 (setq numtimes (getint "\nEnter number of lines:"))
 (setq linefact (getreal "\nEnter keep line factor:")) 
 (setq numcycles (getreal "\nNumber of curve cycles:"))
 ; compute line length, width of boundary
 (setq linelen (- (nth 1 cpnt) (nth 1 spnt)))
 ; compute increment across boundary
 (setq xinc (/ (- (nth 0 cpnt) (nth 0 spnt)) (- numtimes 1)))
 ; computer ang inc
 (setq anginc (/ (* 360.0 numcycles) (- numtimes 1)))
 ; set first point and first x coord
 (setq xpnt spnt)
 (setq xpt (nth 0 spnt))
 ; start ang
 (setq ang 0)
 ; loop to repeat lines
 (repeat numtimes
   ; compute line length
   (setq linepart1 (* linelen linefact)) 
   (setq linepart2 (* (* linelen (- 1.0 linefact)) (abs (sin (dtr ang)))))
   (setq newlinelen (+ linepart1 linepart2))
   ; compute endpoint
   (setq epnt1 (polar xpnt (dtr 90) newlinelen))
   (setq epnt2 (polar xpnt (dtr 270) newlinelen))
   ; compute edge height
   (setq linepart1 (* zedge linefact)) 
   (setq linepart2 (* (* zedge (- 1.0 linefact)) (abs (cos (dtr ang)))))
   (setq newzedge (+ linepart1 linepart2))
   ; compute midpoint height
   (setq linepart1 (* zmid linefact)) 
   (setq linepart2 (* (* zmid (- 1.0 linefact)) (abs (sin (dtr ang)))))
   (setq newzmid (+ linepart1 linepart2))
   ; compute frame points
   (setq pnt1 epnt2)   
   (setq pnt2 (list (nth 0 xpnt) (- (nth 1 xpnt) linelen) (+ (nth 2 xpnt) newzedge)))   
   (setq pnt3 (list (nth 0 xpnt) (nth 1 xpnt) (+ (nth 2 xpnt) newzmid)))   
   (setq pnt4 (list (nth 0 xpnt) (+ (nth 1 xpnt) linelen) (+ (nth 2 xpnt) newzedge)))   
   (setq pnt5 epnt1)   
   ; draw 3DPOLY
   (command ".3DPOLY" pnt1 pnt2 pnt3 pnt4 pnt5 "")
   ; inc x coord
   (setq xpt (+ xpt xinc))
   (setq xpnt (list xpt (nth 1 xpnt) (nth 2 xpnt)))
   ; inc ang
   (setq ang (+ ang anginc))
 )
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 (princ)
)
; --------------------------------------------------------------------------
(defun prog16 ()
 (graphscr)
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 ; get boundary points and parameters
 (prompt "\nPROG16:")
 (setq spnt (getpoint "\nPick start point:"))
 (setq cpnt (getcorner spnt "\nPick end point:"))
 (setq zedge (getdist spnt "\nEnter edge height:"))
 (setq zmid  (getdist spnt "\nEnter midpoint height:"))
 (setq numtimes (getint "\nEnter number of lines:"))
 (setq linefact (getreal "\nEnter keep line factor:")) 
 (setq numcycles (getreal "\nNumber of curve cycles:"))
 ; compute line length, width of boundary
 (setq linelen (- (nth 1 cpnt) (nth 1 spnt)))
 ; compute increment across boundary
 (setq xinc (/ (- (nth 0 cpnt) (nth 0 spnt)) (- numtimes 1)))
 ; computer ang inc
 (setq anginc (/ (* 360.0 numcycles) (- numtimes 1)))
 ; set first point and first x coord
 (setq xpnt spnt)
 (setq xpt (nth 0 spnt))
 ; start ang
 (setq ang 0)
 ; start 3DMESH
 (command ".3DMESH" numtimes "5") 
 ; loop to repeat lines
 (repeat numtimes
   ; compute line length
   (setq linepart1 (* linelen linefact)) 
   (setq linepart2 (* (* linelen (- 1.0 linefact)) (abs (sin (dtr ang)))))
   (setq newlinelen (+ linepart1 linepart2))
   ; compute endpoint
   (setq epnt1 (polar xpnt (dtr 90) newlinelen))
   (setq epnt2 (polar xpnt (dtr 270) newlinelen))
   ; compute edge height
   (setq linepart1 (* zedge linefact)) 
   (setq linepart2 (* (* zedge (- 1.0 linefact)) (abs (cos (dtr ang)))))
   (setq newzedge (+ linepart1 linepart2))
   ; compute midpoint height
   (setq linepart1 (* zmid linefact)) 
   (setq linepart2 (* (* zmid (- 1.0 linefact)) (abs (sin (dtr ang)))))
   (setq newzmid (+ linepart1 linepart2))
   ; compute frame points
   (setq pnt1 epnt2)   
   (setq pnt2 (list (nth 0 epnt2) (nth 1 epnt2) (+ (nth 2 epnt2) newzedge)))   
   (setq pnt3 (list (nth 0 xpnt) (nth 1 xpnt) (+ (nth 2 xpnt) newzmid)))   
   (setq pnt4 (list (nth 0 epnt1) (nth 1 epnt1) (+ (nth 2 epnt1) newzedge)))   
   (setq pnt5 epnt1)   
   ; add points to 3DMESH
   (command pnt1 pnt2 pnt3 pnt4 pnt5) 
   ; inc x coord
   (setq xpt (+ xpt xinc))
   (setq xpnt (list xpt (nth 1 xpnt) (nth 2 xpnt)))
   ; inc ang
   (setq ang (+ ang anginc))
 )
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 (princ)
)
; --------------------------------------------------------------------------
(defun prog17 ()
 (graphscr)
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 ; get boundary points and parameters
 (prompt "\nPROG17:")
 (setq spnt (getpoint "\nPick start point:"))
 (setq cpnt (getcorner spnt "\nPick end point:"))
 (setq zedge (getdist spnt "\nEnter edge height:"))
 (setq zmid  (getdist spnt "\nEnter midpoint height:"))
 (setq numtimes (getint "\nEnter number of lines:"))
 (setq linefact (getreal "\nEnter keep line factor:")) 
 (setq numcycles (getreal "\nNumber of curve cycles:"))
 ; compute line length, width of boundary
 (setq linelen (- (nth 1 cpnt) (nth 1 spnt)))
 ; compute increment across boundary
 (setq xinc (/ (- (nth 0 cpnt) (nth 0 spnt)) (- numtimes 1)))
 ; computer ang inc
 (setq anginc (/ (* 360.0 numcycles) (- numtimes 1)))
 ; set first point and first x coord
 (setq xpnt spnt)
 (setq xpt (nth 0 spnt))
 ; start ang
 (setq ang 0)
 ; start 3DMESH
 (command ".3DMESH" (+ numtimes 2) "6")
 ; frame counter
 (setq cnt 0)
 ; loop to repeat lines
 (repeat numtimes
   ; compute line length
   (setq linepart1 (* linelen linefact)) 
   (setq linepart2 (* (* linelen (- 1.0 linefact)) (abs (sin (dtr ang)))))
   (setq newlinelen (+ linepart1 linepart2))
   ; compute endpoint
   (setq epnt1 (polar xpnt (dtr 90) newlinelen))
   (setq epnt2 (polar xpnt (dtr 270) newlinelen))
   ; compute edge height
   (setq linepart1 (* zedge linefact)) 
   (setq linepart2 (* (* zedge (- 1.0 linefact)) (abs (cos (dtr ang)))))
   (setq newzedge (+ linepart1 linepart2))
   ; compute midpoint height
   (setq linepart1 (* zmid linefact)) 
   (setq linepart2 (* (* zmid (- 1.0 linefact)) (abs (sin (dtr ang)))))
   (setq newzmid (+ linepart1 linepart2))
   ; compute frame points
   (setq pnt1 epnt2)   
   (setq pnt2 (list (nth 0 epnt2) (nth 1 epnt2) (+ (nth 2 epnt2) newzedge)))   
   (setq pnt3 (list (nth 0 xpnt) (nth 1 xpnt) (+ (nth 2 xpnt) newzmid)))   
   (setq pnt4 (list (nth 0 epnt1) (nth 1 epnt1) (+ (nth 2 epnt1) newzedge)))   
   (setq pnt5 epnt1)
   ; inc frames
   (setq cnt (+ cnt 1))
   ; check if before first frame
   (if (= cnt 1)
      (progn
       ; add front face to mesh 
       (command xpnt xpnt xpnt xpnt xpnt xpnt xpnt)
      ))
   ; add points to 3DMESH
   (command pnt1 pnt2 pnt3 pnt4 pnt5 pnt1) 
   ; check if before first frame
   (if (= cnt numtimes)
      (progn
       ; add front face to mesh 
       (command xpnt xpnt xpnt xpnt xpnt xpnt xpnt)
      ))
   ; inc x coord
   (setq xpt (+ xpt xinc))
   (setq xpnt (list xpt (nth 1 xpnt) (nth 2 xpnt)))
   ; inc ang
   (setq ang (+ ang anginc))
 )
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 (princ)
)
; --------------------------------------------------------------------------
(defun prog18 ()
 (graphscr)
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 ; get boundary points and parameters
 (prompt "\nPROG18:")
 (setq spnt (getpoint "\nPick start point:"))
 (setq cpnt (getcorner spnt "\nPick end point:"))
 (setq zedge (getdist spnt "\nEnter edge height:"))
 (setq zmid  (getdist spnt "\nEnter midpoint height:"))
 (setq yoff  (getdist spnt "\nEnter midpoint offset:"))
 (setq numtimes (getint "\nEnter number of lines:"))
 (setq linefact (getreal "\nEnter keep line factor:")) 
 (setq numcycles (getreal "\nNumber of curve cycles:"))
 ; compute line length, width of boundary
 (setq linelen (- (nth 1 cpnt) (nth 1 spnt)))
 ; compute increment across boundary
 (setq xinc (/ (- (nth 0 cpnt) (nth 0 spnt)) (- numtimes 1)))
 ; computer ang inc
 (setq anginc (/ (* 360.0 numcycles) (- numtimes 1)))
 ; set first point and first x coord
 (setq xpnt spnt)
 (setq xpt (nth 0 spnt))
 ; start ang
 (setq ang 0)
 ; start 3DMESH
 (command ".3DMESH" (+ numtimes 2) "6")
 ; frame counter
 (setq cnt 0)
 ; loop to repeat lines
 (repeat numtimes
   ; compute line length
   (setq linepart1 (* linelen linefact)) 
   (setq linepart2 (* (* linelen (- 1.0 linefact)) (abs (sin (dtr ang)))))
   (setq newlinelen (+ linepart1 linepart2))
   ; compute endpoint
   (setq epnt1 (polar xpnt (dtr 90) newlinelen))
   (setq epnt2 (polar xpnt (dtr 270) newlinelen))
   ; compute edge height
   (setq linepart1 (* zedge linefact)) 
   (setq linepart2 (* (* zedge (- 1.0 linefact)) (abs (cos (dtr ang)))))
   (setq newzedge (+ linepart1 linepart2))
   ; compute midpoint height
   (setq linepart1 (* zmid linefact)) 
   (setq linepart2 (* (* zmid (- 1.0 linefact)) (abs (sin (dtr ang)))))
   (setq newzmid (+ linepart1 linepart2))
   ; compute midpoint offset
   (setq newyoff (* yoff (sin (dtr ang))))
   ; compute frame points
   (setq pnt1 epnt2)   
   (setq pnt2 (list (nth 0 epnt2) (nth 1 epnt2) (+ (nth 2 epnt2) newzedge)))   
   (setq pnt3 (list (nth 0 xpnt)  (+ (nth 1 xpnt) newyoff) (+ (nth 2 xpnt) newzmid)))   
   (setq pnt4 (list (nth 0 epnt1) (nth 1 epnt1) (+ (nth 2 epnt1) newzedge)))   
   (setq pnt5 epnt1)
   ; inc frames
   (setq cnt (+ cnt 1))
   ; check if before first frame
   (if (= cnt 1)
      (progn
       ; add front face to mesh 
       (command xpnt xpnt xpnt xpnt xpnt xpnt xpnt)
      ))
   ; add points to 3DMESH
   (command pnt1 pnt2 pnt3 pnt4 pnt5 pnt1) 
   ; check if before first frame
   (if (= cnt numtimes)
      (progn
       ; add front face to mesh 
       (command xpnt xpnt xpnt xpnt xpnt xpnt xpnt)
      ))
   ; inc x coord
   (setq xpt (+ xpt xinc))
   (setq xpnt (list xpt (nth 1 xpnt) (nth 2 xpnt)))
   ; inc ang
   (setq ang (+ ang anginc))
 )
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 (princ)
)
; --------------------------------------------------------------------------
; --------------------------------------------------------------------------
(defun docurve ()
 ; get center point and dimensions
 (prompt "\nDraw curve by entered expression")
 (setq pt0   (getpoint "\nPick start:"))
 (setq cexp   (getstring "\nEnter curve expression:"))
 (setq sang   (getint "\nEnter start angle:"))
 (setq eang   (getint "\nEnter end angle:"))
 ; set Y and X dims
 (setq ymax 50.0)
 (setq xmax 200.0)
 ; draw axis lines 
 (setq pt1 (list (+ (nth 0 pt0) xmax) (nth 1 pt0) 0))
 (command ".LINE" pt0 pt1 "")
 (setq pt1 (list (nth 0 pt0) (+ (nth 1 pt0) ymax) 0))
 (setq pt2 (list (+ (nth 0 pt0) xmax) (+ (nth 1 pt0) ymax) 0))
 (command ".LINE" pt1 pt2 "")
 (setq pt1 (list (nth 0 pt0) (- (nth 1 pt0) ymax) 0))
 (setq pt2 (list (+ (nth 0 pt0) xmax) (- (nth 1 pt0) ymax) 0))
 (command ".LINE" pt1 pt2 "")
 (setq ytext (* (/ ymax 10.0) 0.8))
 (setq pt1 (list (nth 0 pt0) (- (- (nth 1 pt0) ymax) ytext) 0))
 (setq ytext (* (/ ymax 10.0) 0.5))
 (setq stext (strcat cexp " from: " (itoa sang) " to: " (itoa eang))) 
 (command ".TEXT" pt1 ytext "0.0" stext)
 (command ".ZOOM" "e")
 ; ang inc
 (setq anginc 1.0)
 (setq ang sang) 
 ; start and X
 (setq xinc (/ xmax (- eang sang)))
 (setq xpt 0.0) 
 ; start
 (command ".PLINE")
 (while (<= ang eang)
   ; compute height
   (setq ypt (* ymax (eval (read cexp))))
   ; add point
   (command (list (+ (nth 0 pt0) xpt) (+ (nth 1 pt0) ypt) 0))
   ; inc ang and x coord
   (setq ang (+ ang anginc))
   (setq xpt (+ xpt xinc))
  )
  ; close
  (command "")
  (command ".ZOOM" "e" ".ZOOM" "0.9x")
(princ)
)
; --------------------------------------------------------------------------
; --------------------------------------------------------------------------
(defun prog18a ()
 (graphscr)
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 ; get boundary points and parameters
 (prompt "\nPROG18a:")
 (setq spnt (getpoint "\nPick start point:"))
 (setq cpnt (getcorner spnt "\nPick end point:"))
 (setq zedge (getdist spnt "\nEnter edge height:"))
 (setq zmid  (getdist spnt "\nEnter midpoint height:"))
 (setq yoff  (getdist spnt "\nEnter midpoint offset:"))
 (setq numtimes (getint "\nEnter number of lines:"))
 (setq linefact (getreal "\nEnter keep line factor:")) 
 (setq numcycles (getreal "\nNumber of curve cycles:"))
 ; compute line length, width of boundary
 (setq linelen (- (nth 1 cpnt) (nth 1 spnt)))
 ; compute increment across boundary
 (setq xinc (/ (- (nth 0 cpnt) (nth 0 spnt)) (- numtimes 1)))
 ; computer ang inc
 (setq anginc (/ (* 360.0 numcycles) (- numtimes 1)))
 ; set first point and first x coord
 (setq xpnt spnt)
 (setq xpt (nth 0 spnt))
 ; start ang
 (setq ang 0)
 ; start 3DMESH
 (command ".3DMESH" (+ numtimes 2) "6")
 ; frame counter
 (setq cnt 0)
 ; loop to repeat lines
 (repeat numtimes
   ; compute line length
   (setq linepart1 (* linelen linefact)) 
   (setq linepart2 (* (* linelen (- 1.0 linefact)) (abs (sin (dtr ang)))))
   (setq newlinelen (+ linepart1 linepart2))
   ; compute endpoint
   (setq epnt1 (polar xpnt (dtr 90) newlinelen))
   (setq epnt2 (polar xpnt (dtr 270) newlinelen))
   ; compute edge height
   (setq linepart1 (* zedge linefact)) 
   (setq linepart2 (* (* zedge (- 1.0 linefact)) (abs (cos (dtr ang)))))
   (setq newzedge (+ linepart1 linepart2))
   ; compute midpoint height
   (setq linepart1 (* zmid linefact)) 
   (setq linepart2 (* (* zmid (- 1.0 linefact)) (abs (sin (dtr ang)))))
   (setq newzmid (+ linepart1 linepart2))
   ; compute midpoint offset
   (setq newyoff (* yoff (sin (dtr ang))))
   ; compute frame points
   (setq pnt1 epnt2)   
   (setq pnt2 (list (nth 0 epnt2) (nth 1 epnt2) (+ (nth 2 epnt2) newzedge)))   
   (setq pnt3 (list (nth 0 xpnt)  (+ (nth 1 xpnt) newyoff) (+ (nth 2 xpnt) newzmid)))   
   (setq pnt4 (list (nth 0 epnt1) (nth 1 epnt1) (+ (nth 2 epnt1) newzedge)))   
   (setq pnt5 epnt1)
   ; inc frames
   (setq cnt (+ cnt 1))
   ; check if before first frame
   (if (= cnt 1)
      (progn
       ; add front face to mesh 
       (command xpnt xpnt xpnt xpnt xpnt xpnt xpnt)
      ))
   ; add points to 3DMESH
   (command pnt1 pnt2 pnt3 pnt4 pnt5 pnt1) 
   ; check if before first frame
   (if (= cnt numtimes)
      (progn
       ; add front face to mesh 
       (command xpnt xpnt xpnt xpnt xpnt xpnt xpnt)
      ))
   ; inc x coord
   (setq xpt (+ xpt xinc))
   (setq xpnt (list xpt (nth 1 xpnt) (nth 2 xpnt)))
   ; inc ang
   (setq ang (+ ang anginc))
 )
    ; design parameters
    (setq xdim (- (nth 0 cpnt) (nth 0 spnt)))
    (setq ydim (- (nth 1 cpnt) (nth 1 spnt)))
    (setq textpt (list (- (nth 0 spnt) 18) (+ (nth 1 spnt) ydim) 0.0))
    (command ".TEXT" textpt 12 270 
      (strcat "PROG18"
              "/" (rtos xdim 4 2) " X " (rtos ydim 4 2) 
              "/Edge Hght=" (rtos zedge 4 2) 
              "/Mid Hght=" (rtos zmid 4 2) 
      ))
    (setq textpt (list (- (nth 0 textpt) 18) (nth 1 textpt) 0.0))
    (command ".TEXT" textpt 12 270 
      (strcat "/Lines=" (rtos numtimes 2 0) 
              "/Line Factor=" (rtos linefact 2 2) 
              "/Cycles=" (rtos numcycles 2 2) 
      ))
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 (princ)
)
; --------------------------------------------------------------------------
(defun prog19 ()
 (graphscr)
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 ; get boundary points and parameters
 (prompt "\nPROG19:")
 (setq spnt (getpoint "\nPick start point:"))
 (setq cpnt (getcorner spnt "\nPick end point:"))
 (setq zedge (getdist spnt "\nEnter edge height:"))
 (setq zmid  (getdist spnt "\nEnter midpoint height:"))
 (setq yoff  (getdist spnt "\nEnter midpoint offset:"))
 (setq numtimes (getint "\nEnter number of lines:"))
 (setq linefact (getreal "\nEnter keep line factor:")) 
 (setq numcycles (getreal "\nNumber of curve cycles:"))
 ; compute line length, width of boundary
 (setq linelen (- (nth 1 cpnt) (nth 1 spnt)))
 ; compute increment across boundary
 (setq xinc (/ (- (nth 0 cpnt) (nth 0 spnt)) (- numtimes 1)))
 ; computer ang inc
 (setq anginc (/ (* 360.0 numcycles) (- numtimes 1)))
 ; set first point and first x coord
 (setq xpnt spnt)
 (setq xpt (nth 0 spnt))
 ; start ang
 (setq ang 0)
 ; start 3DMESH
 (command ".3DMESH" (+ numtimes 2) "6")
 ; frame counter
 (setq cnt 0)
 ; loop to repeat lines
 (repeat numtimes
   ; compute line length
   (setq linepart1 (* linelen linefact)) 
   (setq linepart2 (* (* linelen (- 1.0 linefact)) (abs (sin (dtr ang)))))
   (setq newlinelen (+ linepart1 linepart2))
   ; compute endpoint
   (setq epnt1 (polar xpnt (dtr 90) newlinelen))
   (setq epnt2 (polar xpnt (dtr 270) newlinelen))
   ; compute edge height
   (setq linepart1 (* zedge linefact)) 
   (setq linepart2 (* (* zedge (- 1.0 linefact)) (abs (cos (dtr ang)))))
   (setq newzedge (+ linepart1 linepart2))
   ; compute midpoint height
   (setq linepart1 (* zmid linefact)) 
   (setq linepart2 (* (* zmid (- 1.0 linefact)) (abs (sin (dtr ang)))))
   (setq newzmid (+ linepart1 linepart2))
   ; compute midpoint offset
   (setq newyoff (* yoff (sin (dtr ang))))
   ; compute frame points
   (setq pnt1 epnt2)   
   (setq pnt2 (list (nth 0 epnt2) (nth 1 epnt2) (+ (nth 2 epnt2) newzedge)))   
   (setq pnt3 (list (nth 0 xpnt)  (+ (nth 1 xpnt) newyoff) (+ (nth 2 xpnt) newzmid)))   
   (setq pnt4 (list (nth 0 epnt1) (nth 1 epnt1) (+ (nth 2 epnt1) newzedge)))   
   (setq pnt5 epnt1)
   ; inc frames
   (setq cnt (+ cnt 1))
   ; check if before first frame
   (if (= cnt 1)
      (progn
       ; add front face to mesh 
       (command xpnt xpnt xpnt xpnt xpnt xpnt xpnt)
      ))
   ; add points to 3DMESH
   (command pnt1 pnt2 pnt3 pnt4 pnt5 pnt1) 
   ; check if before first frame
   (if (= cnt numtimes)
      (progn
       ; add front face to mesh 
       (command xpnt xpnt xpnt xpnt xpnt xpnt xpnt)
      ))
   ; inc x coord
   (setq xpt (+ xpt xinc))
   (setq xpnt (list xpt (nth 1 xpnt) (nth 2 xpnt)))
   ; inc ang
   (setq ang (+ ang anginc))
 )
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 ; rotate vertical
 (command ".ZOOM" "e") 
 (command ".ROTATE3D" "all" "" "Y" "" "-90")
 (command ".ZOOM" "e") 
 (princ)
)
; --------------------------------------------------------------------------
; --------------------------------------------------------------------------
(defun prog20 ()
 (graphscr)
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 ; get boundary points and parameters
 (prompt "\nPROG20:")
 (setq spnt (getpoint "\nPick start point:"))
 (setq cpnt (getcorner spnt "\nPick end point:"))
 (setq zedge (getdist spnt "\nEnter edge height:"))
 (setq zmid  (getdist spnt "\nEnter midpoint height:"))
 (setq yoff  (getdist spnt "\nEnter midpoint offset:"))
 (setq numtimes (getint "\nEnter number of lines:"))
 (setq linefact (getreal "\nEnter keep line factor:")) 
 (setq numcycles (getreal "\nNumber of curve cycles:"))
 ; compute line length, width of boundary
 (setq linelen (- (nth 1 cpnt) (nth 1 spnt)))
 ; compute increment across boundary
 (setq xinc (/ (- (nth 0 cpnt) (nth 0 spnt)) (- numtimes 1)))
 ; computer ang inc
 (setq anginc (/ (* 360.0 numcycles) (- numtimes 1)))
 ; set first point and first x coord
 (setq xpnt spnt)
 (setq xpt (nth 0 spnt))
 ; start ang
 (setq ang 0)
 ; start 3DMESH
 (command ".3DMESH" (+ numtimes 2) "9")
 ; frame counter
 (setq cnt 0)
 ; loop to repeat lines
 (repeat numtimes
   ; compute line length
   (setq linepart1 (* linelen linefact)) 
   (setq linepart2 (* (* linelen (- 1.0 linefact)) (abs (sin (dtr ang)))))
   (setq newlinelen (+ linepart1 linepart2))
   ; compute endpoint
   (setq epnt1 (polar xpnt (dtr 90) newlinelen))
   (setq epnt2 (polar xpnt (dtr 270) newlinelen))
   ; compute edge height
   (setq linepart1 (* zedge linefact)) 
   (setq linepart2 (* (* zedge (- 1.0 linefact)) (abs (cos (dtr ang)))))
   (setq newzedge (+ linepart1 linepart2))
   ; compute midpoint height
   (setq linepart1 (* zmid linefact)) 
   (setq linepart2 (* (* zmid (- 1.0 linefact)) (abs (sin (dtr ang)))))
   (setq newzmid (+ linepart1 linepart2))
   ; compute midpoint offset
   (setq newyoff (* yoff (sin (dtr ang))))
   ; compute frame points
   (setq pnt1 epnt2)   
   (setq pnt2 (list (nth 0 epnt2) (nth 1 epnt2) (+ (nth 2 epnt2) newzedge)))   
   (setq pnt3 (list (nth 0 xpnt)  (+ (nth 1 xpnt) newyoff) (+ (nth 2 xpnt) newzmid)))   
   (setq pnt4 (list (nth 0 epnt1) (nth 1 epnt1) (+ (nth 2 epnt1) newzedge)))   
   (setq pnt5 epnt1)
   (setq pnt6 (list (nth 0 pnt5) (nth 1 pnt5) (- newzedge)))  
   (setq pnt7 (list (nth 0 pnt3) (nth 1 pnt3) (- newzmid)))  
   (setq pnt8 (list (nth 0 pnt1) (nth 1 pnt1) (- newzedge)))  
   ; inc frames
   (setq cnt (+ cnt 1))
   ; check if before first frame
   (if (= cnt 1)
      (progn
       ; add front face to mesh 
       (command xpnt xpnt xpnt xpnt xpnt xpnt xpnt xpnt xpnt)
      ))
   ; add points to 3DMESH
   (command pnt1 pnt2 pnt3 pnt4 pnt5 pnt6 pnt7 pnt8 pnt1) 
   ; check if before first frame
   (if (= cnt numtimes)
      (progn
       ; add front face to mesh 
       (command xpnt xpnt xpnt xpnt xpnt xpnt xpnt xpnt xpnt)
      ))
   ; inc x coord
   (setq xpt (+ xpt xinc))
   (setq xpnt (list xpt (nth 1 xpnt) (nth 2 xpnt)))
   ; inc ang
   (setq ang (+ ang anginc))
 )
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 ; rotate vertical
 (command ".ZOOM" "e") 
 (command ".ROTATE3D" "all" "" "Y" "" "-90")
 (command ".ZOOM" "e") 
 (princ)
)
; --------------------------------------------------------------------------
; --------------------------------------------------------------------------
(defun prog21 ()
 (graphscr)
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 ; get boundary points and parameters
 (prompt "\nPROG21:")
 (setq spnt (getpoint "\nPick start point:"))
 (setq cpnt (getcorner spnt "\nPick end point:"))
 (setq zedge (getdist spnt "\nEnter edge height:"))
 (setq zmid  (getdist spnt "\nEnter midpoint height:"))
 (setq yoff  (getdist spnt "\nEnter midpoint offset:"))
 (setq numtimes (getint "\nEnter number of lines:"))
 (setq linefact (getreal "\nEnter keep line factor:")) 
 (setq numcycles (getreal "\nNumber of curve cycles:"))
 (setq clang     (getreal "\Enter total angle for centerline:"))
 (setq cangoff   (getdist "\nEnter centerline angle offset:")) 
 ; compute line length, width of boundary
 (setq linelen (- (nth 1 cpnt) (nth 1 spnt)))
 ; compute increment across boundary
 (setq xinc (/ (- (nth 0 cpnt) (nth 0 spnt)) (- numtimes 1)))
 ; computer ang inc
 (setq anginc (/ (* 360.0 numcycles) (- numtimes 1)))
 (setq canginc (/ clang (- numtimes 1)))
 ; set first point and first x coord
 (setq xpnt spnt)
 (setq xpt (nth 0 spnt))
 ; start ang
 (setq ang 0)
 (setq cang 0) 
 ; start 3DMESH
 (command ".3DMESH" (+ numtimes 2) "6")
 ; frame counter
 (setq cnt 0)
 ; loop to repeat lines
 (repeat numtimes
   ; new centerline
   (setq clangoff (* (sin (dtr cang)) cangoff))
   (setq xpnt (list (nth 0 xpnt) (+ (nth 1 spnt) clangoff) (nth 2 xpnt)))
   ; set direction
   (setq ldirang 90)
   (setq rdirang 270)
   (if (> cnt 0) (progn
     (setq dirang (rtd (angle lpnt xpnt)))
     (setq ldirang (+ dirang 90))
     (setq rdirang (- dirang 90))
   ))	 	   
   ; compute line length
   (setq linepart1 (* linelen linefact)) 
   (setq linepart2 (* (* linelen (- 1.0 linefact)) (abs (sin (dtr ang)))))
   (setq newlinelen (+ linepart1 linepart2))
   ; compute endpoint
   (setq epnt1 (polar xpnt (dtr ldirang) newlinelen))
   (setq epnt2 (polar xpnt (dtr rdirang) newlinelen))
   ; compute edge height
   (setq linepart1 (* zedge linefact)) 
   (setq linepart2 (* (* zedge (- 1.0 linefact)) (abs (cos (dtr ang)))))
   (setq newzedge (+ linepart1 linepart2))
   ; compute midpoint height
   (setq linepart1 (* zmid linefact)) 
   (setq linepart2 (* (* zmid (- 1.0 linefact)) (abs (sin (dtr ang)))))
   (setq newzmid (+ linepart1 linepart2))
   ; compute midpoint offset
   (setq newyoff (* yoff (sin (dtr ang))))
   ; compute frame points
   (setq pnt1 epnt2)   
   (setq pnt2 (list (nth 0 epnt2) (nth 1 epnt2) (+ (nth 2 epnt2) newzedge)))   
   (setq pnt3 (list (nth 0 xpnt)  (+ (nth 1 xpnt) newyoff) (+ (nth 2 xpnt) newzmid)))   
   (setq pnt4 (list (nth 0 epnt1) (nth 1 epnt1) (+ (nth 2 epnt1) newzedge)))   
   (setq pnt5 epnt1)
   ; inc frames
   (setq cnt (+ cnt 1))
   ; check if before first frame
   (if (= cnt 1)
      (progn
       ; add front face to mesh 
       (command xpnt xpnt xpnt xpnt xpnt xpnt xpnt)
      ))
   ; add points to 3DMESH
   (command pnt1 pnt2 pnt3 pnt4 pnt5 pnt1) 
   ; check if before first frame
   (if (= cnt numtimes)
      (progn
       ; add front face to mesh 
       (command xpnt xpnt xpnt xpnt xpnt xpnt xpnt)
      ))
   ; same last center point
   (setq lpnt xpnt)
   ; inc x coord
   (setq xpt (+ xpt xinc))
   (setq xpnt (list xpt (nth 1 xpnt) (nth 2 xpnt)))
   ; inc ang
   (setq ang (+ ang anginc))
   (setq cang (+ cang canginc))
 )
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 (princ)
)
; --------------------------------------------------------------------------
; --------------------------------------------------------------------------
; --------------------------------------------------------------------------
; prog91  - three part section cut, create dwg for cutting
; prog92  - 3D view of model
; --------------------------------------------------------------------------
(defun prog91 ()
 ; laser cuts for model
 ; based on PROG14
 ; laser cut sections with no base slots
 ; sections at 3/16" 
 ; 16 x 24 laser bed
 (setvar "CMDECHO" 1)
 (graphscr)
 (command ".LAYER" "THAW" "*" "ON" "*" "")
 (c:vt)
 (command ".ZOOM" "e") 
 (command ".ERASE" "ALL" "")
 (command ".LAYER" "MAKE" "2DTEXT" "MAKE" "2DCUT" "MAKE" "3DID" "MAKE" "LAYOUT" "")
 (command ".LAYER" "COLOR" "7" "*" "")  
 (command ".LAYER" "COLOR" "1" "2DCUT" "")  
 (command ".LAYER" "COLOR" "3" "2DTEXT" "")
 (command ".LAYER" "OFF" "2DCUT,2DTEXT" "FREEZE" "2DCUT,2DTEXT" "")
 (command ".LAYER" "SET" "0" "")
 ;board
 ;(setq bthick (/ 3.0 16.0))
 ;(setq bwid 15)
 ;(setq blen 20) 
 ; get boundary points and parameters
 (prompt "\nRepeat lines within a box")
 (setq spnt (list 0.0 0.0 0.0))
 (setq scriptid (getstring "\nScript id:"))
 (setq modelid (getstring "\nModel id: "))
 (setq modelid (substr (strcase modelid) 1 1))
 (setq clen (getreal "\nLength (ft):"))
 (setq cwid (getreal "\nWidth (ft):"))
 (setq zedge (getreal "\nEdge height (ft):"))
 (setq zmid (getreal "\nMidpoint height (ft):"))
 (setq eblenfact (getreal "\nBottom edge length keep line factor:")) 
 (setq eblsang (getreal "\nBottom edge length, start angle:"))
 (setq ebleang (getreal "\nBottom edge length, end angle:"))
 (setq eblenfunc (getstring "\nBottom edge length function:"))
 (setq etlenfact (getreal "\nTop edge length keep line factor:")) 
 (setq etlsang (getreal "\nTop edge length, start angle:"))
 (setq etleang (getreal "\nTop edge length, end angle:"))
 (setq etlenfunc (getstring "\nTop edge length function:"))
 (setq ehgtfact (getreal "\nEdge height keep line factor:")) 
 (setq ehsang (getreal "\nEdge height, start angle:"))
 (setq eheang (getreal "\nEdge height, end angle:"))
 (setq ehgtfunc (getstring "Edge height function:"))
 (setq mhgtfact (getreal "\nMidpoint height keep line factor:")) 
 (setq mhsang (getreal "\nMidpoint height, start angle:"))
 (setq mheang (getreal "\nMidpoint height, end angle:"))
 (setq mhgtfunc (getstring "Midpoint height function:"))
 (setq zmidoff (getreal "\nMidpoint offset (ft):"))
 (setq mhoffsang (getreal "\nMidpoint offset, start angle:"))
 (setq mhoffeang (getreal "\nMidpoint offset, end angle:"))
 (setq mhgtofffunc (getstring "Midpoint offset function:"))
 (setq frad (getreal "\nFillet radius (in):")) 
 (setq foff (getreal "\nFrame offset (in):")) 
 (setq noff  (getreal "\nNegative offset top and sides (in):"))
 (setq nboff (getreal "\nNegative offset bottom (in):"))
 (setq modellen (getreal "\nModel length (in):")) 
 (setq bthick (getreal "\nBoard thickness (in):")) 
 (setq bwid (getreal "\nBoard width (in):")) 
 (setq blen (getreal "\nBoard length (in):"))
 ; model parms
 (setq numtimes (fix (/ modellen bthick)))
 ; model scale
 (setq mscale (/ modellen (* clen 12)))       
 (setq mclen (* (* clen 12) mscale))
 (setq mcwid (* (* cwid 12) mscale))
 (setq cpnt (list mclen (/ mcwid 2.0) 0.0))  
 (setq mzedge (* (* zedge 12) mscale))
 (setq mzmid (* (* zmid 12) mscale))
 (setq mzmidoff (* (* zmidoff 12) mscale))
 (setq mfrad (* frad mscale)) 
 (setq mfoff (* foff mscale)) 
 (setq mnoff (* noff mscale)) 
 (setq mnboff (* nboff mscale)) 
 ; compute line length, width of box
 (setq linelen (- (nth 1 cpnt) (nth 1 spnt)))
 ; compute increment across box
 (setq xinc (/ (- (nth 0 cpnt) (nth 0 spnt)) (- numtimes 1)))
 ; computer ang inc
 (setq blanginc (/ (- ebleang eblsang) (- numtimes 1)))
 (setq tlanginc (/ (- etleang etlsang) (- numtimes 1)))
 (setq eanginc (/ (- eheang ehsang) (- numtimes 1)))
 (setq manginc (/ (- mheang mhsang) (- numtimes 1)))
 (setq oanginc (/ (- mhoffeang mhoffsang) (- numtimes 1)))
 ; set first point and first x coord
 (setq xpnt spnt)
 ; set angle computations
 (if (= (strcase eblenfunc) "SIN") 
     (defun blfuncang (xrad) (sin xrad))
     (defun blfuncang (xrad) (cos xrad)))
 (if (= (strcase etlenfunc) "SIN") 
     (defun tlfuncang (xrad) (sin xrad))
     (defun tlfuncang (xrad) (cos xrad)))
 (if (= (strcase ehgtfunc) "SIN") 
     (defun efuncang (xrad) (sin xrad))
     (defun efuncang (xrad) (cos xrad)))
 (if (= (strcase mhgtfunc) "SIN") 
     (defun mfuncang (xrad) (sin xrad))
     (defun mfuncang (xrad) (cos xrad)))
 (if (= (strcase mhgtofffunc) "SIN") 
     (defun ofuncang (xrad) (sin xrad))
     (defun ofuncang (xrad) (cos xrad)))
 ; start ang
 (setq blang eblsang)
 (setq tlang etlsang)
 (setq eang ehsang)
 (setq mang mhsang)
 (setq oang mhoffsang) 
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 ; loop to repeat lines
 (setq nsect 0) 
 (repeat numtimes
   ; compute bottom endpoint
   (setq line1 (* linelen eblenfact)) 
   (setq line2 (* (* (* linelen (- 1.0 eblenfact)) (abs (blfuncang (dtr blang))))))
   (setq newlen (+ line1 line2))
   (setq epnt1 (polar xpnt (dtr 90) newlen))
   (setq epnt2 (polar xpnt (dtr 270) newlen))
   ; compute top endpoint
   (setq line1 (* linelen etlenfact)) 
   (setq line2 (* (* (* linelen (- 1.0 etlenfact)) (abs (tlfuncang (dtr tlang))))))
   (setq newlen (+ line1 line2))
   (setq epnt3 (polar xpnt (dtr 90) newlen))
   (setq epnt4 (polar xpnt (dtr 270) newlen))
   ; compute outside height
   (setq line1 (* mzedge ehgtfact)) 
   (setq line2 (* (* (* mzedge (- 1.0 ehgtfact)) (abs (efuncang (dtr eang))))))
   (setq newzedge (+ line1 line2))
   (setq epnt3 (list (+ (nth 0 epnt3) newzedge) (nth 1 epnt3) ))
   (setq epnt4 (list (+ (nth 0 epnt4) newzedge) (nth 1 epnt4) ))
   ; compute midpoint offset
   (setq newzmidoff (* (* mzmidoff (ofuncang (dtr oang)))))
   (setq epnt5 (list (nth 0 xpnt) (+ (nth 1 xpnt) newzmidoff)))
   ; compute midpoint height
   (setq line1 (* mzmid mhgtfact)) 
   (setq line2 (* (* (* mzmid (- 1.0 mhgtfact)) (abs (mfuncang (dtr mang))))))
   (setq newzmid (+ line1 line2))
   (setq epnt5 (list (+ (nth 0 epnt5) newzmid) (nth 1 epnt5) ))
   ; center slot
   (setq xpntc (list (nth 0 xpnt) (nth 1 xpnt) ))
   (setq epnt6 (list (nth 0 xpntc) (+ (nth 1 xpntc) (/ 1.0 4.0)) ))
   (setq epnt7 (list (+ (nth 0 xpntc) (/ 1.0 32.0)) (+ (nth 1 xpntc) (/ 1.0 4.0)) ))
   (setq epnt10 (list (+ (nth 0 xpntc) (/ 1.0 32.0)) (nth 1 xpntc) ))
   (setq epnt8 (list (+ (nth 0 xpntc) (/ 1.0 32.0)) (- (nth 1 xpntc) (/ 1.0 4.0)) ))
   (setq epnt9 (list (nth 0 xpntc) (- (nth 1 xpntc) (/ 1.0 4.0)) ))
   (setq nsect (+ nsect 1))
   ; pline for 2D 
   ;(command ".PLINE" epnt10 epnt7 epnt6 epnt1 epnt3 epnt5 epnt4 epnt2 epnt9 epnt8 "C")
   (command ".PLINE" epnt6 epnt1 epnt3 epnt5 epnt4 epnt2 epnt9 "C")
   (command ".ZOOM" "E" ".ZOOM" "0.6x")
   ; round corners
   (setq ss1 (ssget "_L"))
   (if (> mfrad 0.0) (progn
       (command ".FILLET" "R" mfrad)
       (command ".FILLET" "P" epnt1)
   ))
   ;(command ".ZOOM" "E" ".ZOOM" "0.6x")
   ; duplicate
   (if (> mfoff 0.0) (progn
   (setq opnt (list (- (nth 0 epnt6) mfoff) (nth 1 epnt6)))
   (command ".OFFSET" mfoff epnt6 opnt "")
   ; tab cut
   ;(command ".LINE" epnt6 epnt9 "")
   ))
   ; top tab cut
   (command ".PLINE" epnt6 epnt7 epnt10 epnt8 epnt9 "")
   ; bottom tab cut
   (if (> mfoff 0.0) (progn
   ;(setq epnt6 (list (- (nth 0 xpntc) mfoff) (+ (nth 1 xpntc) (/ 1.0 2.0)) ))
   ;(setq epnt9 (list (- (nth 0 xpntc) mfoff) (- (nth 1 xpntc) (/ 1.0 2.0)) ))
   ;(setq opnt (list (+ (- (nth 0 epnt7) mnboff) (/ 1.0 32.0)) (nth 1 epnt7)))
   ;(command ".COPY" epnt7 "" epnt7 opnt)
   ;(command ".LINE" epnt6 epnt9 "")
   (setq epnt6 (list (- (nth 0 xpntc) mfoff) (+ (nth 1 xpntc) (/ 1.0 4.0)) ))
   (setq epnt7 (list (+ (- (nth 0 xpntc) mfoff) (/ 1.0 32.0)) (+ (nth 1 xpntc) (/ 1.0 4.0)) ))
   (setq epnt10 (list (+ (- (nth 0 xpntc) mfoff) (/ 1.0 32.0)) (nth 1 xpntc) ))
   (setq epnt8 (list (+ (- (nth 0 xpntc) mfoff) (/ 1.0 32.0)) (- (nth 1 xpntc) (/ 1.0 4.0)) ))
   (setq epnt9 (list (- (nth 0 xpntc) mfoff) (- (nth 1 xpntc) (/ 1.0 4.0)) ))
   (command ".PLINE" epnt6 epnt7 epnt10 epnt8 epnt9 "")
   ))
   (command ".ZOOM" "E" ".ZOOM" "0.6x")
   ; negative frame
   (if (> mnoff 0.0) (progn
   (setq xpnt1 (list (- (nth 0 xpntc) (+ mfoff mnboff)) (+ (+ (nth 1 xpntc) (/ mcwid 2)) (* mnoff 2)) ))
   (setq xpnt2 (list (- (nth 0 xpntc) (+ mfoff mnboff)) (- (- (nth 1 xpntc) (/ mcwid 2)) (* mnoff 2)) ))
   (setq xpnt3 (list (+ (nth 0 xpnt1) (+ (max mzedge mzmid) (+ (* mnoff 3) mnboff))) (nth 1 xpnt1) ))
   (setq xpnt4 (list (+ (nth 0 xpnt2) (+ (max mzedge mzmid) (+ (* mnoff 3) mnboff))) (nth 1 xpnt2) ))
   (command ".PLINE" xpnt1 xpnt3 xpnt4 xpnt2 xpnt1 "")
   ))
   ; add sect number
   ; positive
   (command ".TEXT" (list (+ (nth 0 xpntc) (/ 1.0 16.0)) (nth 1 xpntc)) (/ 1.0 16.0) "-90"
	    (strcat modelid "-" (itoa nsect)))
   (command ".CHPROP" "L" "" "LAYER" "2DTEXT" "")
   ; positive
   (if (> mfoff 0.0) (progn
   (command ".TEXT" (list (+ (- (nth 0 xpntc) mfoff) (/ 1.0 128.0)) (+ (nth 1 xpntc) (/ 3.0 4.0))) (/ 1.0 16.0) "-90"
	    (strcat modelid "-" (itoa nsect)))
   (command ".CHPROP" "L" "" "LAYER" "2DTEXT" "")
   ))
   ; negative
   (if (> mnoff 0.0) (progn
   (command ".TEXT" (list (+ (nth 0 xpntc) (+ (max mzedge mzmid) (* mnoff 1))) (nth 1 xpntc)) (/ 1.0 16.0) "-90"
	    (strcat modelid "-" (itoa nsect)))
   (command ".CHPROP" "L" "" "LAYER" "2DTEXT" "")
   ))
   (command ".ZOOM" "E" ".ZOOM" "0.6x")
   (command ".CHPROP" "ALL" "" "LAYER" "2DCUT" "")
   ; next location
   (setq xnext (+ (+ 0 (+ (max mzedge mzmid) (+ (* mnoff 3) mnboff))) (/ 1.0 8.0)) )
   (setq ynext (+ (+ (/ mcwid 1) (* (+ mnoff mfoff) 2)) (/ 1.0 4.0)))
   (setq xpnt (list (+ (nth 0 xpnt) xnext) (nth 1 xpnt) ))
   (if (> (+ (nth 0 xpnt) xnext) (+ (nth 0 spnt) bwid)) (progn
     (setq xpnt (list (nth 0 spnt) (- (nth 1 xpnt) ynext)))
     ))
   ; inc ang
   (setq blang (+ blang blanginc))
   (setq tlang (+ tlang tlanginc))
   (setq eang (+ eang eanginc))
   (setq mang (+ mang manginc))
   (setq oang (+ oang oanginc))
 )
 ; layout 2D
 (command ".LAYER" "SET" "LAYOUT" "")
 (setq epnt1 (list (- (nth 0 spnt) 0.5) (+ (nth 1 cpnt) 0.75) 0.0))
 (setq epnt2 (list (+ (nth 0 epnt1) bwid) (nth 1 epnt1) 0.0))
 (setq epnt3 (list (+ (nth 0 epnt1) bwid) (- (nth 1 epnt1) blen) 0.0))
 (setq epnt4 (list (- (nth 0 spnt) 0.5) (nth 1 epnt3) 0.0))
 (command ".PLINE" epnt1 epnt2 epnt3 epnt4 epnt1 "")
 (command ".LAYER" "SET" "0" "")
 (command ".LAYER" "THAW" "*" "ON" "*" "")
 (command ".CHPROP" "ALL" "" "COLOR" "BYLAYER" "")
 (c:vt)
 ; cut length
 (setq minpt (getvar "EXTMIN"))
 (setq maxpt (getvar "EXTMAX")) 
 (setq cutlen (fix (+ 0.5 (abs (- (nth 1 minpt) (nth 1 maxpt))))))  
 ; id text
 (setq epnt1 (list (- (nth 0 spnt) 2.0) (nth 1 epnt3) 0.0))
 (command ".TEXT" epnt1 (/ 1.0 4.0) "90"
	  (strcat scriptid "/" (rtos clen 2 2) "/" (rtos cwid 2 2 ) "/" (rtos zedge 2 2 ) "/"
		  (rtos zmid 2 2 ) "/" (rtos modellen 2 2 ) "/" (itoa numtimes) "/" 
	          (rtos bwid 2 2) "x" (rtos cutlen 2 2) "/"))
 (princ)
)
; --------------------------------------------------------------------------
; --------------------------------------------------------------------------
(defun prog92 ()
 ; 3D view of model
 ; based on PROG14
 ; laser cut sections with no base slots
 ; sections at 3/16" 
 ; 16 x 24 laser bed
 (setvar "CMDECHO" 0)
 (graphscr)
 (command ".LAYER" "THAW" "*" "ON" "*" "")
 (c:vt)
 (command ".ZOOM" "e") 
 (command ".ERASE" "ALL" "")
 (command ".LAYER" "MAKE" "3DSECT" "MAKE" "3DBASE" "MAKE" "2DTEXT"
	   "MAKE" "2DCUT" "MAKE" "3DID" "MAKE" "LAYOUT" "")
 (command ".LAYER" "COLOR" "7" "*" "")  
 (command ".LAYER" "COLOR" "1" "2DCUT" "")  
 (command ".LAYER" "COLOR" "3" "2DTEXT" "")  
 (command ".LAYER" "OFF" "3DSECT,3DBASE" "")
 ; board
 ;(setq bthick (/ 3.0 16.0))
 ;(setq bwid 15)
 ;(setq blen 20) 
 ; get boundary points and parameters
 (prompt "\nRepeat lines within a box")
 (setq spnt (list 0.0 0.0 0.0))
 (setq scriptid (getstring "\nScript id:"))
 (setq modelid (getstring "\nModel id: "))
 (setq modelid (substr (strcase modelid) 1 1))
 (setq clen (getreal "\nLength (ft):"))
 (setq cwid (getreal "\nWidth (ft):"))
 (setq zedge (getreal "\nEdge height (ft):"))
 (setq zmid (getreal "\nMidpoint height (ft):"))
 (setq eblenfact (getreal "\nBottom edge length keep line factor:")) 
 (setq eblsang (getreal "\nBottom edge length, start angle:"))
 (setq ebleang (getreal "\nBottom edge length, end angle:"))
 (setq eblenfunc (getstring "\nBottom edge length function:"))
 (setq etlenfact (getreal "\nTop edge length keep line factor:")) 
 (setq etlsang (getreal "\nTop edge length, start angle:"))
 (setq etleang (getreal "\nTop edge length, end angle:"))
 (setq etlenfunc (getstring "\nTop edge length function:"))
 (setq ehgtfact (getreal "\nEdge height keep line factor:")) 
 (setq ehsang (getreal "\nEdge height, start angle:"))
 (setq eheang (getreal "\nEdge height, end angle:"))
 (setq ehgtfunc (getstring "\nEdge height function:"))
 (setq mhgtfact (getreal "\nMidpoint height keep line factor:")) 
 (setq mhsang (getreal "\nMidpoint height, start angle:"))
 (setq mheang (getreal "\nMidpoint height, end angle:"))
 (setq mhgtfunc (getstring "\nMidpoint height function:"))
 (setq zmidoff (getreal "\nMidpoint offset (ft):"))
 (setq mhoffsang (getreal "\nMidpoint offset, start angle:"))
 (setq mhoffeang (getreal "\nMidpoint offset, end angle:"))
 (setq mhgtofffunc (getstring "\nMidpoint offset function:"))
 (setq frad (getreal "\nFillet radius (in):")) 
 (setq foff (getreal "\nFrame offset (in):")) 
 (setq noff  (getreal "\nNegative offset top and sides (in):"))
 (setq nboff (getreal "\nNegative offset bottom (in):"))
 (setq modellen (getreal "\nModel length (in):")) 
 (setq bthick (getreal "\nBoard thickness (in):")) 
 (setq bwid (getreal "\nBoard width (in):")) 
 (setq blen (getreal "\nBoard length (in):"))
 ; model parms
 (setq numtimes (fix (/ modellen bthick)))
 ; model scale
 (setq mscale (/ modellen (* clen 12)))       
 (setq mclen (* (* clen 12) mscale))
 (setq mcwid (* (* cwid 12) mscale))
 (setq cpnt (list mclen (/ mcwid 2.0) 0.0))  
 (setq mzedge (* (* zedge 12) mscale))
 (setq mzmid (* (* zmid 12) mscale))
 (setq mzmidoff (* (* zmidoff 12) mscale))
 (setq mfrad (* frad mscale)) 
 (setq mfoff (* foff mscale)) 
 (setq mnoff (* noff mscale)) 
 (setq mnboff (* nboff mscale)) 
 ; compute line length, width of box
 (setq linelen (- (nth 1 cpnt) (nth 1 spnt)))
 ; compute increment across box
 (setq xinc (/ (- (nth 0 cpnt) (nth 0 spnt)) (- numtimes 1)))
 ; computer ang inc
 (setq blanginc (/ (- ebleang eblsang) (- numtimes 1)))
 (setq tlanginc (/ (- etleang etlsang) (- numtimes 1)))
 (setq eanginc (/ (- eheang ehsang) (- numtimes 1)))
 (setq manginc (/ (- mheang mhsang) (- numtimes 1)))
 (setq oanginc (/ (- mhoffeang mhoffsang) (- numtimes 1)))
 ; set first point and first x coord
 (setq xpnt spnt)
 (setq xpt (nth 0 spnt))
 ; set angle computations
 (if (= (strcase eblenfunc) "SIN") 
     (defun blfuncang (xrad) (sin xrad))
     (defun blfuncang (xrad) (cos xrad)))
 (if (= (strcase etlenfunc) "SIN") 
     (defun tlfuncang (xrad) (sin xrad))
     (defun tlfuncang (xrad) (cos xrad)))
 (if (= (strcase ehgtfunc) "SIN") 
     (defun efuncang (xrad) (sin xrad))
     (defun efuncang (xrad) (cos xrad)))
 (if (= (strcase mhgtfunc) "SIN") 
     (defun mfuncang (xrad) (sin xrad))
     (defun mfuncang (xrad) (cos xrad)))
 (if (= (strcase mhgtofffunc) "SIN") 
     (defun ofuncang (xrad) (sin xrad))
     (defun ofuncang (xrad) (cos xrad)))
 ; start ang
 (setq blang eblsang)
 (setq tlang etlsang)
 (setq eang ehsang)
 (setq mang mhsang)
 (setq oang mhoffsang) 
 ; set extrude height
 (command ".ELEV" 0.0 0.0)
 ; start pts for sections 
 (setq sxcpnt (- (nth 0 spnt) 1.0))
 (setq xcpnt sxcpnt) 
 (setq ycpnt (- (nth 1 cpnt) (+ (* linelen 3.0) 1.1)))
 ; loop to repeat lines
 (setq nsect 0) 
 (repeat numtimes
   ; compute bottom endpoint
   (setq line1 (* linelen eblenfact)) 
   (setq line2 (* (* (* linelen (- 1.0 eblenfact)) (abs (blfuncang (dtr blang))))))
   (setq newlen (+ line1 line2))
   (setq epnt3 (polar xpnt (dtr 90) newlen))
   (setq epnt4 (polar xpnt (dtr 270) newlen))
   ; compute top endpoint
   (setq line1 (* linelen etlenfact)) 
   (setq line2 (* (* (* linelen (- 1.0 etlenfact)) (abs (tlfuncang (dtr tlang))))))
   (setq newlen (+ line1 line2))
   (setq epnt1 (polar xpnt (dtr 90) newlen))
   (setq epnt2 (polar xpnt (dtr 270) newlen))
   ; compute outside height
   (setq line1 (* mzedge ehgtfact)) 
   (setq line2 (* (* (* mzedge (- 1.0 ehgtfact)) (abs (efuncang (dtr eang))))))
   (setq newzedge (+ line1 line2))
   (setq epnt1 (list (nth 0 epnt1) (nth 1 epnt1) newzedge))
   (setq epnt2 (list (nth 0 epnt2) (nth 1 epnt2) newzedge))
   ; compute midpoint offset
   (setq newzmidoff (* (* mzmidoff (ofuncang (dtr oang)))))
   (setq mpnt (list (nth 0 xpnt) (+ (nth 1 xpnt) newzmidoff) 0.0))
   ; compute midpoint height
   (setq line1 (* mzmid mhgtfact)) 
   (setq line2 (* (* (* mzmid (- 1.0 mhgtfact)) (abs (mfuncang (dtr mang))))))
   (setq newzmid (+ line1 line2))
   (setq mpnt (list (nth 0 mpnt) (nth 1 mpnt) newzmid))
   (setq nsect (+ nsect 1))
   ; pline for 3D 
   (command ".LAYER" "SET" "3DSECT" "")
   (command ".3DPOLY" epnt3 epnt1 mpnt epnt2 epnt4 epnt3 "")
   (command ".EXTRUDE" "LAST" "" bthick "" ) 
   (command ".ZOOM" "E")
   ; inc x coord
   (setq xpt (+ xpt xinc))
   (setq xpnt (cons xpt (cdr xpnt)))
   ; inc ang
   (setq blang (+ blang blanginc))
   (setq tlang (+ tlang tlanginc))
   (setq eang (+ eang eanginc))
   (setq mang (+ mang manginc))
   (setq oang (+ oang oanginc))
 )
 ; base 3D
 (setq epnt2 (list (- (nth 0 spnt) 1.0) (+ (nth 1 cpnt) 1.0) 0.0))
 (setq epnt3 (list (+ (nth 0 cpnt) 1.0) (+ (nth 1 cpnt) 1.0) 0.0))
 (setq epnt4 (list (+ (nth 0 cpnt) 1.0) (* (+ (nth 1 cpnt) 1.0) -1.0) 0.0))
 (setq epnt5 (list (- (nth 0 spnt) 1.0) (* (+ (nth 1 cpnt) 1.0) -1.0) 0.0))
 (command ".LAYER" "SET" "3DBASE" "")
 (command ".3DFACE" epnt2 epnt3 epnt4 epnt5  "")
 (command ".ZOOM" "e")
 ; id text
 (setq epnt1 (list (+ (nth 0 spnt) 0.5) (+ (nth 1 cpnt) 2.5) 0.0))  
 (command ".LAYER" "SET" "3DID" "")
 (command ".TEXT" epnt1 (/ 1.0 4.0) "0"
	  (strcat scriptid "/" (rtos clen 2 2) "/" (rtos cwid 2 2 ) "/" (rtos zedge 2 2 ) "/"
		  (rtos zmid 2 2 ) "/" (rtos modellen 2 2 ) "/" (itoa numtimes) "/" ))
 (command ".LAYER" "SET" "0" "")
 (command ".CHPROP" "ALL" "" "COLOR" "BYLAYER" "")
 (command ".LAYER" "ON" "3DSECT,3DBASE" "")
 (command ".LAYER" "OFF" "2D*,LAYOUT" "FREEZE" "2D*,LAYOUT"  "") 
 (c:vsw)
 (command ".HIDE") 
 (princ)
)
;----------------------------------------------------------------------------
;--------------------------------------------------------------------------   
(defun prog61 ()
 (graphscr)
 ; tower repeats
 (setvar "CMDECHO" 0)
 ; center point
 (setq cpnt (list 0.0 0.0 0.0))
 ; get curve parameters
 (princ "\nProg61 - Tower")
 (setq TowerLayer  (getstring "\nEnter layer name: "))
 (setq NumLevels   (getint "\nEnter number of levels: "))
 (setq LevelHeight (getdist "\nEnter level height: "))
 (setq NumSides    (getint "\nEnter number of polygon sides: "))
 (setq Rad         (getdist "\nEnter radius: "))
 ; clear layer
 (command ".LAYER" "THAW" "*" "ON" "*" "")
 (command ".LAYER" "MAKE" TowerLayer "")
 (command ".LAYER" "SET" 0 "")
 (command ".LAYER" "OFF" "@*" "FREEZE" "@*" "")
 (command ".LAYER" "THAW" TowerLayer "ON" TowerLayer "SET" TowerLayer "")
 (command ".ERASE" "ALL" "")
 ; set elev
 (setq LevelElev 0.0)
 ; start mesh 
 (command ".3DMESH" (+ NumLevels 1) (+ NumSides 1))
 ; create each level 
 (repeat (+ NumLevels 1)
   ; draw polygon
   (setq panginc (/ 360.0 NumSides))
   (setq pang (/ panginc 2.0))
   (repeat (+ NumSides 1)
     ; compute point
     (setq xpt (+ (nth 0 cpnt) (* Rad (sin (dtr pang)))))
     (setq ypt (+ (nth 1 cpnt) (* Rad (cos (dtr pang)))))
     (setq npnt (list xpt ypt LevelElev))
     ; add to mesh 
     (command npnt)
     ; inc ang
     (setq pang (+ pang panginc))
   )
   ; inc elev
   (setq LevelElev (+ LevelElev LevelHeight))
 )
 (setvar "CMDECHO" 1)
 (princ)
)
;--------------------------------------------------------------------------   
(defun prog61a ()
 (graphscr)
 ; tower by polygon repeats
 ; add bottom and top
 (setvar "CMDECHO" 0)
 ; center point
 (setq cpnt (list 0.0 0.0 0.0))
 ; get curve parameters
 (princ "\nProg61a - Tower")
 (setq TowerLayer  (getstring "\nEnter layer name: "))
 (setq NumLevels   (getint "\nEnter number of levels: "))
 (setq LevelHeight (getdist "\nEnter level height: "))
 (setq NumSides    (getint "\nEnter number of polygon sides: "))
 (setq Rad         (getdist "\nEnter radius: "))
 ; clear layer
 (command ".LAYER" "THAW" "*" "ON" "*" "")
 (command ".LAYER" "MAKE" TowerLayer "")
 (command ".LAYER" "SET" 0 "")
 (command ".LAYER" "OFF" "@*" "FREEZE" "@*" "")
 (command ".LAYER" "THAW" TowerLayer "ON" TowerLayer "SET" TowerLayer "")
 (command ".ERASE" "ALL" "")
 ; set elev
 (setq LevelElev 0.0)
 ; start mesh 
 (command ".3DMESH" (+ (+ NumLevels 1) 2) (+ NumSides 1))
 ; add bottom
 (setq npnt cpnt) 
 (repeat (+ NumSides 1)
   (command npnt)
 )
 ; create each level 
 (repeat (+ NumLevels 1)
   ; draw polygon
   (setq panginc (/ 360.0 NumSides))
   (setq pang (/ panginc 2.0))
   (repeat (+ NumSides 1)
     ; compute point
     (setq xpt (+ (nth 0 cpnt) (* Rad (sin (dtr pang)))))
     (setq ypt (+ (nth 1 cpnt) (* Rad (cos (dtr pang)))))
     (setq npnt (list xpt ypt LevelElev))
     ; add to mesh 
     (command npnt)
     ; inc ang
     (setq pang (+ pang panginc))
   )
   ; inc elev
   (setq LevelElev (+ LevelElev LevelHeight))
 )
 ; add top
 (setq npnt (list (nth 0 cpnt) (nth 1 cpnt) (- LevelElev LevelHeight))) 
 (repeat (+ NumSides 1)
   (command npnt)
 )
 ; set view
 (c:vsw)
 ; hide
 (command ".HIDE")
 (setvar "CMDECHO" 1)
 (princ)
)
;--------------------------------------------------------------------------   
(defun prog61b ()
 (graphscr)
 ; tower by polygon repeats
 ; taper
 (setvar "CMDECHO" 0)
 ; center point
 (setq cpnt (list 0.0 0.0 0.0))
 ; get curve parameters
 (princ "\nProg61b - Tower")
 (setq TowerLayer  (getstring "\nEnter layer name: "))
 (setq NumLevels   (getint "\nEnter number of levels: "))
 (setq LevelHeight (getdist "\nEnter level height: "))
 (setq NumSides    (getint "\nEnter number of polygon sides: "))
 (setq RadStart    (getdist "\nEnter start radius: "))
 (setq RadEnd      (getdist "\nEnter end radius: "))
 ; clear layer
 (command ".LAYER" "THAW" "*" "ON" "*" "")
 (command ".LAYER" "MAKE" TowerLayer "")
 (command ".LAYER" "SET" 0 "")
 (command ".LAYER" "OFF" "@*" "FREEZE" "@*" "")
 (command ".LAYER" "THAW" TowerLayer "ON" TowerLayer "SET" TowerLayer "")
 (command ".ERASE" "ALL" "")
 ; set elev
 (setq LevelElev 0.0)
 ; start mesh 
 (command ".3DMESH" (+ (+ NumLevels 1) 2) (+ NumSides 1))
 ; add bottom
 (setq npnt cpnt) 
 (repeat (+ NumSides 1)
   (command npnt)
 )
 ; radius inc
 (setq RadInc (/ (- RadEnd RadStart) NumLevels)) 
 (setq Rad RadStart)
 ; create each level 
 (repeat (+ NumLevels 1)
   ; draw polygon
   (setq panginc (/ 360.0 NumSides))
   (setq pang (/ panginc 2.0))
   (repeat (+ NumSides 1)
     ; compute point
     (setq xpt (+ (nth 0 cpnt) (* Rad (sin (dtr pang)))))
     (setq ypt (+ (nth 1 cpnt) (* Rad (cos (dtr pang)))))
     (setq npnt (list xpt ypt LevelElev))
     ; add to mesh 
     (command npnt)
     ; inc ang
     (setq pang (+ pang panginc))
   )
   ; inc radius
   (setq Rad (+ Rad RadInc))
   ; inc elev
   (setq LevelElev (+ LevelElev LevelHeight))
 )
 ; add top
 (setq npnt (list (nth 0 cpnt) (nth 1 cpnt) (- LevelElev LevelHeight)))
 (repeat (+ NumSides 1)
   (command npnt)
 )
 ; set view
 (c:vsw)
 ; hide
 (command ".HIDE")
 (setvar "CMDECHO" 1)
 (princ)
)
;--------------------------------------------------------------------------   
(defun prog61c ()
 (graphscr)
 ; tower by polygon repeats
 ; twist 
 (setvar "CMDECHO" 0)
 ; center point
 (setq cpnt (list 0.0 0.0 0.0))
 ; get curve parameters
 (princ "\nProg61c - Tower")
 (setq TowerLayer  (getstring "\nEnter layer name: "))
 (setq NumLevels   (getint "\nEnter number of levels: "))
 (setq LevelHeight (getdist "\nEnter level height: "))
 (setq NumSides    (getint "\nEnter number of polygon sides: "))
 (setq RadStart    (getdist "\nEnter start radius: "))
 (setq RadEnd      (getdist "\nEnter end radius: "))
 (setq RotTotal    (getreal "\nEnter total rotation angle: "))
 ; clear layer
 (command ".LAYER" "THAW" "*" "ON" "*" "")
 (command ".LAYER" "MAKE" TowerLayer "")
 (command ".LAYER" "SET" 0 "")
 (command ".LAYER" "OFF" "@*" "FREEZE" "@*" "")
 (command ".LAYER" "THAW" TowerLayer "ON" TowerLayer "SET" TowerLayer "")
 (command ".ERASE" "ALL" "")
 ; set elev
 (setq LevelElev 0.0)
 ; start mesh 
 (command ".3DMESH" (+ (+ NumLevels 1) 2) (+ NumSides 1))
 ; add bottom
 (setq npnt cpnt) 
 (repeat (+ NumSides 1)
   (command npnt)
 )
 ; radius inc
 (setq RadInc (/ (- RadEnd RadStart) NumLevels)) 
 (setq Rad RadStart)
 ; rotation inc
 (setq RotInc (/ RotTotal NumLevels)) 
 (setq Rotang 0.0)  
 ; create each level 
 (repeat (+ NumLevels 1)
   ; draw polygon
   (setq panginc (/ 360.0 NumSides))
   (setq pang (/ panginc 2.0))
   (repeat (+ NumSides 1)
     ; compute point
     (setq xpt (+ (nth 0 cpnt) (* Rad (sin (dtr pang)))))
     (setq ypt (+ (nth 1 cpnt) (* Rad (cos (dtr pang)))))
     ; rotate
     (setq rxpt (- (* xpt (cos (dtr Rotang))) (* ypt (sin (dtr Rotang)))))
     (setq rypt (+ (* xpt (sin (dtr Rotang))) (* ypt (cos (dtr Rotang))))) 
     (setq npnt (list rxpt rypt LevelElev))
     ; add to mesh 
     (command npnt)
     ; inc ang
     (setq pang (+ pang panginc))
   )
   ; inc radius
   (setq Rad (+ Rad RadInc))
   ; inc elev
   (setq LevelElev (+ LevelElev LevelHeight))
   ; inc rotation
   (setq Rotang (+ Rotang Rotinc))
 )
 ; add top
 (setq npnt (list (nth 0 cpnt) (nth 1 cpnt) (- LevelElev LevelHeight)))
 (repeat (+ NumSides 1)
   (command npnt)
 )
 ; set view
 (c:vsw)
 ; hide
 (command ".HIDE")
 (setvar "CMDECHO" 1)
 (princ)
)
;--------------------------------------------------------------------------   
(defun prog61d ()
 (graphscr)
 ; tower by polygon repeats
 ; taper
 (setvar "CMDECHO" 0)
 ; center point
 (setq cpnt (list 0.0 0.0 0.0))
 ; get curve parameters
 (princ "\nProg61d - Tower")
 (setq TowerLayer  (getstring "\nEnter layer name: "))
 (setq NumLevels   (getint "\nEnter number of levels: "))
 (setq LevelHeight (getdist "\nEnter level height: "))
 (setq NumSides    (getint "\nEnter number of polygon sides: "))
 (setq RadStart    (getdist "\nEnter start radius: "))
 (setq RadEnd      (getdist "\nEnter end radius: "))
 (setq Xoffset     (getdist "\nEnter top X offset: "))
 (setq Yoffset     (getdist "\nEnter top Y offset: "))
 ; clear layer
 (command ".LAYER" "THAW" "*" "ON" "*" "")
 (command ".LAYER" "MAKE" TowerLayer "")
 (command ".LAYER" "SET" 0 "")
 (command ".LAYER" "OFF" "@*" "FREEZE" "@*" "")
 (command ".LAYER" "THAW" TowerLayer "ON" TowerLayer "SET" TowerLayer "")
 (command ".ERASE" "ALL" "")
 ; set elev
 (setq LevelElev 0.0)
 ; start mesh 
 (command ".3DMESH" (+ (+ NumLevels 1) 2) (+ NumSides 1))
 ; add bottom
 (setq npnt cpnt) 
 (repeat (+ NumSides 1)
   (command npnt)
 )
 ; radius inc
 (setq RadInc (/ (- RadEnd RadStart) NumLevels)) 
 (setq Rad RadStart)
 ; offset inc
 (setq XoffInc (/ Xoffset NumLevels)) 
 (setq Xoff 0.0)
 (setq YoffInc (/ Yoffset NumLevels)) 
 (setq Yoff 0.0)
 ; create each level 
 (repeat (+ NumLevels 1)
   ; draw polygon
   (setq panginc (/ 360.0 NumSides))
   (setq pang (/ panginc 2.0))
   (repeat (+ NumSides 1)
     ; compute point
     (setq xpt (+ (+ (nth 0 cpnt) (* Rad (sin (dtr pang)))) Xoff))
     (setq ypt (+ (+ (nth 1 cpnt) (* Rad (cos (dtr pang)))) Yoff))
     (setq npnt (list xpt ypt LevelElev))
     ; add to mesh 
     (command npnt)
     ; inc ang
     (setq pang (+ pang panginc))
   )
   ; inc radius
   (setq Rad (+ Rad RadInc))
   ; inc elev
   (setq LevelElev (+ LevelElev LevelHeight))
   ; inc offset
   (setq Xoff (+ Xoff XoffInc))
   (setq Yoff (+ Yoff YoffInc))
 )
 ; add top
 (setq npnt (list (nth 0 cpnt) (nth 1 cpnt) (- LevelElev LevelHeight)))
 (repeat (+ NumSides 1)
   (command npnt)
 )
 ; set view
 (c:vsw)
 ; hide
 (command ".HIDE")
 (setvar "CMDECHO" 1)
 (princ)
)
;--------------------------------------------------------------------------   
(defun prog61e ()
 (graphscr)
 ; tower by polygon repeats
 ; elliptical form 
 (setvar "CMDECHO" 0)
 ; center point
 (setq cpnt (list 0.0 0.0 0.0))
 ; get curve parameters
 (princ "\nProg61e - Tower")
 (setq TowerLayer  (getstring "\nEnter layer name: "))
 (setq NumLevels   (getint "\nEnter number of levels: "))
 (setq LevelHeight (getdist "\nEnter level height: "))
 (setq NumSides    (getint "\nEnter number of polygon sides: "))
 (setq XRadStart   (getdist "\nEnter start X radius: "))
 (setq XRadEnd     (getdist "\nEnter end X radius: "))
 (setq YRad        (getdist "\nEnter Y radius: "))
 (setq RotTotal    (getreal "\nEnter total rotation angle: "))
 ; clear layer
 (command ".LAYER" "THAW" "*" "ON" "*" "")
 (command ".LAYER" "MAKE" TowerLayer "")
 (command ".LAYER" "SET" 0 "")
 (command ".LAYER" "OFF" "@*" "FREEZE" "@*" "")
 (command ".LAYER" "THAW" TowerLayer "ON" TowerLayer "SET" TowerLayer "")
 (command ".ERASE" "ALL" "")
 ; set elev
 (setq LevelElev 0.0)
 ; start mesh 
 (command ".3DMESH" (+ (+ NumLevels 1) 2) (+ NumSides 1))
 ; add bottom
 (setq npnt cpnt) 
 (repeat (+ NumSides 1)
   (command npnt)
 )
 ; radius inc
 (setq XRadInc (/ (- XRadEnd XRadStart) NumLevels)) 
 (setq XRad XRadStart)
 ; rotation inc
 (setq RotInc (/ RotTotal NumLevels)) 
 (setq Rotang 0.0)  
 ; create each level 
 (repeat (+ NumLevels 1)
   ; draw polygon
   (setq panginc (/ 360.0 NumSides))
   (setq pang (/ panginc 2.0))
   (repeat (+ NumSides 1)
     ; compute point
     (setq xpt (+ (nth 0 cpnt) (* XRad (sin (dtr pang)))))
     (setq ypt (+ (nth 1 cpnt) (* YRad (cos (dtr pang)))))
     ; rotate
     (setq rxpt (- (* xpt (cos (dtr Rotang))) (* ypt (sin (dtr Rotang)))))
     (setq rypt (+ (* xpt (sin (dtr Rotang))) (* ypt (cos (dtr Rotang))))) 
     (setq npnt (list rxpt rypt LevelElev))
     ; add to mesh 
     (command npnt)
     ; inc ang
     (setq pang (+ pang panginc))
   )
   ; inc radius
   (setq XRad (+ XRad XRadInc))
   ; inc elev
   (setq LevelElev (+ LevelElev LevelHeight))
   ; inc rotation
   (setq Rotang (+ Rotang Rotinc))
 )
 ; add top
 (setq npnt (list (nth 0 cpnt) (nth 1 cpnt) (- LevelElev LevelHeight)))
 (repeat (+ NumSides 1)
   (command npnt)
 )
 ; set view
 (c:vsw)
 ; hide
 (command ".HIDE")
 (setvar "CMDECHO" 1)
 (princ)
)
;--------------------------------------------------------------------------   
(defun prog61m ()
 (graphscr)
 ; tower by polygon repeats
 ; elliptical form 
 (setvar "CMDECHO" 0)
 ; center point
 (setq cpnt (list 0.0 0.0 0.0))
 ; get curve parameters
 (princ "\nProg61e - Tower")
 (setq TowerLayer  (getstring "\nEnter layer name: "))
 (setq NumLevels   (getint "\nEnter number of levels: "))
 (setq LevelHeight (getdist "\nEnter level height: "))
 (setq NumSides    (getint "\nEnter number of polygon sides: "))
 (setq XRadStart   (getdist "\nEnter start X radius: "))
 (setq XRadEnd     (getdist "\nEnter end X radius: "))
 (setq YRadStart   (getdist "\nEnter start Y radius: "))
 (setq YRadEnd     (getdist "\nEnter end Y radius: "))
 (setq RotTotal    (getreal "\nEnter total rotation angle: "))
 ; clear layer
 (command ".LAYER" "THAW" "*" "ON" "*" "")
 (command ".LAYER" "MAKE" TowerLayer "")
 (command ".LAYER" "SET" 0 "")
 (command ".LAYER" "OFF" "@*" "FREEZE" "@*" "")
 (command ".LAYER" "THAW" TowerLayer "ON" TowerLayer "SET" TowerLayer "")
 (command ".ERASE" "ALL" "")
 ; set elev
 (setq LevelElev 0.0)
 ; start mesh 
 (command ".3DMESH" (+ (+ NumLevels 1) 2) (+ NumSides 1))
 ; add bottom
 (setq npnt cpnt) 
 (repeat (+ NumSides 1)
   (command npnt)
 )
 ; radius inc
 (setq XRadInc (/ (- XRadEnd XRadStart) NumLevels)) 
 (setq XRad XRadStart)
 (setq YRadInc (/ (- YRadEnd YRadStart) NumLevels)) 
 (setq YRad YRadStart)
 ; rotation inc
 (setq RotInc (/ RotTotal NumLevels)) 
 (setq Rotang 0.0)  
 ; create each level 
 (repeat (+ NumLevels 1)
   ; draw polygon
   (setq panginc (/ 360.0 NumSides))
   (setq pang (/ panginc 2.0))
   (repeat (+ NumSides 1)
     ; compute point
     (setq xpt (+ (nth 0 cpnt) (* XRad (sin (dtr pang)))))
     (setq ypt (+ (nth 1 cpnt) (* YRad (cos (dtr pang)))))
     ; rotate
     (setq rxpt (- (* xpt (cos (dtr Rotang))) (* ypt (sin (dtr Rotang)))))
     (setq rypt (+ (* xpt (sin (dtr Rotang))) (* ypt (cos (dtr Rotang))))) 
     (setq npnt (list rxpt rypt LevelElev))
     ; add to mesh 
     (command npnt)
     ; inc ang
     (setq pang (+ pang panginc))
   )
   ; inc radius
   (setq XRad (+ XRad XRadInc))
   (setq YRad (+ YRad YRadInc))
   ; inc elev
   (setq LevelElev (+ LevelElev LevelHeight))
   ; inc rotation
   (setq Rotang (+ Rotang Rotinc))
 )
 ; add top
 (setq npnt (list (nth 0 cpnt) (nth 1 cpnt) (- LevelElev LevelHeight)))
 (repeat (+ NumSides 1)
   (command npnt)
 )
 ; set view
 (c:vsw)
 ; hide
 (command ".HIDE")
 (setvar "CMDECHO" 1)
 (princ)
)
;--------------------------------------------------------------------------   
(defun prog61n ()
 (graphscr)
 ; tower by polygon repeats
 ; elliptical form 
 (setvar "CMDECHO" 0)
 ; center point
 (setq cpnt (list 0.0 0.0 0.0))
 ; get curve parameters
 (princ "\nProg61e - Tower")
 (setq TowerLayer  (getstring "\nEnter layer name: "))
 (setq NumLevels   (getint "\nEnter number of levels: "))
 (setq LevelHeight (getdist "\nEnter level height: "))
 (setq NumSides    (getint "\nEnter number of polygon sides: "))
 (setq XRadStart   (getdist "\nEnter start X radius: "))
 (setq XRadEnd     (getdist "\nEnter end X radius: "))
 (setq YRadStart   (getdist "\nEnter start Y radius: "))
 (setq YRadEnd     (getdist "\nEnter end Y radius: "))
 (setq RotTotal    (getreal "\nEnter total rotation angle: "))
 (setq XRotOff     (getdist "\nEnter X rotation offset: "))
 (setq YRotOff     (getdist "\nEnter Y rotation offset: "))
 ; clear layer
 (command ".LAYER" "THAW" "*" "ON" "*" "")
 (command ".LAYER" "MAKE" TowerLayer "")
 (command ".LAYER" "SET" 0 "")
 (command ".LAYER" "OFF" "@*" "FREEZE" "@*" "")
 (command ".LAYER" "THAW" TowerLayer "ON" TowerLayer "SET" TowerLayer "")
 (command ".ERASE" "ALL" "")
 ; set elev
 (setq LevelElev 0.0)
 ; start mesh 
 (command ".3DMESH" (+ (+ NumLevels 1) 2) (+ NumSides 1))
 ; add bottom
 (setq npnt cpnt) 
 (repeat (+ NumSides 1)
   (command npnt)
 )
 ; radius inc
 (setq XRadInc (/ (- XRadEnd XRadStart) NumLevels)) 
 (setq XRad XRadStart)
 (setq YRadInc (/ (- YRadEnd YRadStart) NumLevels)) 
 (setq YRad YRadStart)
 ; rotation inc
 (setq RotInc (/ RotTotal NumLevels)) 
 (setq Rotang 0.0)
 ; offset inc
 (setq XOffInc (/ XRotOff NumLevels)) 
 (setq XOff 0.0)
 (setq YOffInc (/ YRotOff NumLevels)) 
 (setq YOff 0.0)
 ; create each level 
 (repeat (+ NumLevels 1)
   ; draw polygon
   (setq panginc (/ 360.0 NumSides))
   (setq pang (/ panginc 2.0))
   (repeat (+ NumSides 1)
     ; compute point
     (setq xpt (+ (nth 0 cpnt) (* XRad (sin (dtr pang)))))
     (setq ypt (+ (nth 1 cpnt) (* YRad (cos (dtr pang)))))
     ; rotate
     (setq rxpt (+ XOff (- (* xpt (cos (dtr Rotang))) (* ypt (sin (dtr Rotang)))))) 
     (setq rypt (+ YOff (+ (* xpt (sin (dtr Rotang))) (* ypt (cos (dtr Rotang)))))) 
     (setq npnt (list rxpt rypt LevelElev))
     ; add to mesh 
     (command npnt)
     ; inc ang
     (setq pang (+ pang panginc))
   )
   ; inc radius
   (setq XRad (+ XRad XRadInc))
   (setq YRad (+ YRad YRadInc))
   ; inc elev
   (setq LevelElev (+ LevelElev LevelHeight))
   ; inc rotation
   (setq Rotang (+ Rotang Rotinc))
   ; inc offset
   (setq XOff (+ XOff XOffInc))
   (setq YOff (+ YOff YOffInc))
 )
 ; add top
 (setq npnt (list (nth 0 cpnt) (nth 1 cpnt) (- LevelElev LevelHeight)))
 (repeat (+ NumSides 1)
   (command npnt)
 )
 ; set view
 (c:vsw)
 ; hide
 (command ".HIDE")
 (setvar "CMDECHO" 1)
 (princ)
)
;--------------------------------------------------------------------------   
(defun prog61f ()
 (graphscr)
 ; tower by polygon repeats
 ; curve applied to offset 
 (setvar "CMDECHO" 0)
 ; center point
 (setq cpnt (list 0.0 0.0 0.0))
 ; get curve parameters
 (princ "\nProg61f - Tower")
 (setq TowerLayer  (getstring "\nEnter layer name: "))
 (setq NumLevels   (getint "\nEnter number of levels: "))
 (setq LevelHeight (getdist "\nEnter level height: "))
 (setq NumSides    (getint "\nEnter number of polygon sides: "))
 (setq Rad         (getdist "\nEnter radius: "))
 (setq RadOff      (getdist "\nEnter radius offset: ")) 
 (setq RadOffAng   (getreal "\nEnter radius offset angle: ")) 
 (setq RotTotal    (getreal "\nEnter total rotation angle: "))
 ; clear layer
 (command ".LAYER" "THAW" "*" "ON" "*" "")
 (command ".LAYER" "MAKE" TowerLayer "")
 (command ".LAYER" "SET" 0 "")
 (command ".LAYER" "OFF" "@*" "FREEZE" "@*" "")
 (command ".LAYER" "THAW" TowerLayer "ON" TowerLayer "SET" TowerLayer "")
 (command ".ERASE" "ALL" "")
 ; set elev
 (setq LevelElev 0.0)
 ; start mesh 
 (command ".3DMESH" (+ (+ NumLevels 1) 2) (+ NumSides 1))
 ; add bottom
 (setq npnt cpnt) 
 (repeat (+ NumSides 1)
   (command npnt)
 )
 ; offset ang
 (setq ranginc (/ RadOffAng Numlevels))
 (setq rang 0.0) 
 ; rotation inc
 (setq RotInc (/ RotTotal NumLevels)) 
 (setq Rotang 0.0)  
 ; create each level 
 (repeat (+ NumLevels 1)
   ; draw polygon
   (setq panginc (/ 360.0 NumSides))
   (setq pang (/ panginc 2.0))
   (repeat (+ NumSides 1)
     ; compute point
     (setq NewRad (+ Rad (* (sin (dtr rang)) RadOff)))
     (setq xpt (+ (nth 0 cpnt) (* NewRad (sin (dtr pang)))))
     (setq ypt (+ (nth 1 cpnt) (* NewRad (cos (dtr pang)))))
     ; rotate
     (setq rxpt (- (* xpt (cos (dtr Rotang))) (* ypt (sin (dtr Rotang)))))
     (setq rypt (+ (* xpt (sin (dtr Rotang))) (* ypt (cos (dtr Rotang))))) 
     (setq npnt (list rxpt rypt LevelElev))
     ; add to mesh 
     (command npnt)
     ; inc ang
     (setq pang (+ pang panginc))
   )
   ; inc offset angle
   (setq rang (+ rang ranginc))
   ; inc elev
   (setq LevelElev (+ LevelElev LevelHeight))
   ; inc rotation
   (setq Rotang (+ Rotang Rotinc))
 )
 ; add top
 (setq npnt (list (nth 0 cpnt) (nth 1 cpnt) (- LevelElev LevelHeight)))
 (repeat (+ NumSides 1)
   (command npnt)
 )
 ; set view
 (c:vsw)
 ; hide
 (command ".HIDE")
 (setvar "CMDECHO" 1)
 (princ)
)
;--------------------------------------------------------------------------   
(defun prog61g3 ()
 (graphscr)
 ; tower repeats
 ; 4 sides
 ; curve on two opposite corners
 (setvar "CMDECHO" 0)
 ; center point
 (setq cpnt (list 0.0 0.0 0.0))
 ; get curve parameters
 (princ "\nProg61g - Tower")
 (setq TowerLayer  (getstring "\nEnter layer name: "))
 (setq NumLevels   (getint "\nEnter number of levels: "))
 (setq LevelHeight (getdist "\nEnter level height: "))
 (setq Rad         (getdist "\nEnter radius: "))
 (setq RadOff      (getdist "\nEnter radius offset: ")) 
 (setq RadOffAng   (getreal "\nEnter radius offset angle: ")) 
 (setq RotTotal    (getreal "\nEnter total rotation angle: "))
 ; clear layer
 (command ".LAYER" "THAW" "*" "ON" "*" "")
 (command ".LAYER" "MAKE" TowerLayer "")
 (command ".LAYER" "SET" 0 "")
 (command ".LAYER" "OFF" "@*" "FREEZE" "@*" "")
 (command ".LAYER" "THAW" TowerLayer "ON" TowerLayer "SET" TowerLayer "")
 (command ".ERASE" "ALL" "")
 ; number of sides
 (setq NumSides 3)
 ; set elev
 (setq LevelElev 0.0)
 ; start mesh 
 (command ".3DMESH" (+ (+ NumLevels 1) 2) (+ NumSides 1))
 ; add bottom
 (setq npnt cpnt) 
 (repeat (+ NumSides 1)
   (command npnt)
 )
 ; rotation inc
 (setq RotInc (/ RotTotal NumLevels)) 
 (setq Rotang 0.0)  
 ; offset ang
 (setq ranginc (/ RadOffAng Numlevels))
 (setq rang 0.0) 
 ; create each level 
 (repeat (+ NumLevels 1)
   ; draw polygon
   (setq panginc (/ 360.0 NumSides))
   (setq pang (+ (/ panginc 2.0) Rotang))
   ; compute points
   (setq pnt1 (polar cpnt (dtr pang) (+ Rad (* (sin (dtr rang)) RadOff)))) 
   (setq pnt1 (list (nth 0 pnt1) (nth 1 pnt1) LevelElev))
   (setq pang (+ pang panginc))
   (setq pnt2 (polar cpnt (dtr pang) Rad))
   (setq pnt2 (list (nth 0 pnt2) (nth 1 pnt2) LevelElev))
   (setq pang (+ pang panginc))
   (setq pnt3 (polar cpnt (dtr pang) Rad))
   (setq pnt3 (list (nth 0 pnt3) (nth 1 pnt3) LevelElev))
   ; add to mesh 
   (command pnt1 pnt2 pnt3 pnt1)
   ; inc offset angle
   (setq rang (+ rang ranginc))
   ; inc elev
   (setq LevelElev (+ LevelElev LevelHeight))
   ; inc rotation
   (setq Rotang (+ Rotang Rotinc))
 )
 ; add top
 (setq npnt (list (nth 0 cpnt) (nth 1 cpnt) (- LevelElev LevelHeight)))
 (repeat (+ NumSides 1)
   (command npnt)
 )
 ; set view
 (c:vsw)
 ; hide
 (command ".HIDE")
 (setvar "CMDECHO" 1)
 (princ)
)
;--------------------------------------------------------------------------   
(defun prog61g4 ()
 (graphscr)
 ; tower repeats
 ; 4 sides
 ; curve on two opposite corners
 (setvar "CMDECHO" 0)
 ; center point
 (setq cpnt (list 0.0 0.0 0.0))
 ; get curve parameters
 (princ "\nProg61g - Tower")
 (setq TowerLayer  (getstring "\nEnter layer name: "))
 (setq NumLevels   (getint "\nEnter number of levels: "))
 (setq LevelHeight (getdist "\nEnter level height: "))
 (setq Rad         (getdist "\nEnter radius: "))
 (setq RadOff      (getdist "\nEnter radius offset: ")) 
 (setq RadOffAng   (getreal "\nEnter radius offset angle: ")) 
 (setq RotTotal    (getreal "\nEnter total rotation angle: "))
 ; clear layer
 (command ".LAYER" "THAW" "*" "ON" "*" "")
 (command ".LAYER" "MAKE" TowerLayer "")
 (command ".LAYER" "SET" 0 "")
 (command ".LAYER" "OFF" "@*" "FREEZE" "@*" "")
 (command ".LAYER" "THAW" TowerLayer "ON" TowerLayer "SET" TowerLayer "")
 (command ".ERASE" "ALL" "")
 ; number of sides
 (setq NumSides 4)
 ; set elev
 (setq LevelElev 0.0)
 ; start mesh 
 (command ".3DMESH" (+ (+ NumLevels 1) 2) (+ NumSides 1))
 ; add bottom
 (setq npnt cpnt) 
 (repeat (+ NumSides 1)
   (command npnt)
 )
 ; rotation inc
 (setq RotInc (/ RotTotal NumLevels)) 
 (setq Rotang 0.0)  
 ; offset ang
 (setq ranginc (/ RadOffAng Numlevels))
 (setq rang 0.0) 
 ; create each level 
 (repeat (+ NumLevels 1)
   ; draw polygon
   (setq panginc (/ 360.0 NumSides))
   (setq pang (+ (/ panginc 2.0) Rotang))
   ; compute points
   (setq pnt1 (polar cpnt (dtr pang) (+ Rad (* (sin (dtr rang)) RadOff)))) 
   (setq pnt1 (list (nth 0 pnt1) (nth 1 pnt1) LevelElev))
   (setq pang (+ pang panginc))
   (setq pnt2 (polar cpnt (dtr pang) Rad))
   (setq pnt2 (list (nth 0 pnt2) (nth 1 pnt2) LevelElev))
   (setq pang (+ pang panginc))
   (setq pnt3 (polar cpnt (dtr pang) (+ Rad (* (sin (dtr rang)) RadOff)))) 
   (setq pnt3 (list (nth 0 pnt3) (nth 1 pnt3) LevelElev))
   (setq pang (+ pang panginc))
   (setq pnt4 (polar cpnt (dtr pang) Rad))
   (setq pnt4 (list (nth 0 pnt4) (nth 1 pnt4) LevelElev))
   ; add to mesh 
   (command pnt1 pnt2 pnt3 pnt4 pnt1)
   ; inc offset angle
   (setq rang (+ rang ranginc))
   ; inc elev
   (setq LevelElev (+ LevelElev LevelHeight))
   ; inc rotation
   (setq Rotang (+ Rotang Rotinc))
 )
 ; add top
 (setq npnt (list (nth 0 cpnt) (nth 1 cpnt) (- LevelElev LevelHeight)))
 (repeat (+ NumSides 1)
   (command npnt)
 )
 ; set view
 (c:vsw)
 ; hide
 (command ".HIDE")
 (setvar "CMDECHO" 1)
 (princ)
)
;--------------------------------------------------------------------------   
(defun prog61h1 ()
 (graphscr)
 ; tower repeats
 ; Cardioid curve for section
 ; x = 2 a cos t (1 + cos t)
 ; y = 2 a sin t (1 + cos t)
  (setvar "CMDECHO" 0)
 ; center point
 (setq cpnt (list 0.0 0.0 0.0))
 ; get curve parameters
 (princ "\nProg61h1 - Tower")
 (setq TowerLayer  (getstring "\nEnter layer name: "))
 (setq NumLevels   (getint "\nEnter number of levels: "))
 (setq LevelHeight (getdist "\nEnter level height: "))
 (setq NumSides    (getint "\nEnter number of curve sides: "))
 (setq RadStart    (getdist "\nEnter start radius: "))
 (setq RadEnd      (getdist "\nEnter radius end: ")) 
 ; clear layer
 (command ".LAYER" "THAW" "*" "ON" "*" "")
 (command ".LAYER" "MAKE" TowerLayer "")
 (command ".LAYER" "SET" 0 "")
 (command ".LAYER" "OFF" "@*" "FREEZE" "@*" "")
 (command ".LAYER" "THAW" TowerLayer "ON" TowerLayer "SET" TowerLayer "")
 (command ".ERASE" "ALL" "")
 ; set elev
 (setq LevelElev 0.0)
 ; start mesh 
 (command ".3DMESH" (+ (+ NumLevels 1) 2) (+ NumSides 1))
 ; add bottom
 (setq npnt cpnt) 
 (repeat (+ NumSides 1)
   (command npnt)
 )
 ; radius inc
 (setq RadInc (/ (- RadEnd RadStart) NumLevels)) 
 (setq Rad RadStart)
 ; create each level 
 (repeat (+ NumLevels 1)
   ; draw polygon
   (setq panginc (/ 360.0 NumSides))
   (setq pang 0.0)
   (repeat (+ NumSides 1)
     ; compute point
     (setq xpt (* 2 (* (/ Rad 4) (* (cos (dtr pang)) (+ 1 (cos (dtr pang)))))))
     (setq ypt (* 2 (* (/ Rad 4) (* (sin (dtr pang)) (+ 1 (cos (dtr pang)))))))
     (setq npnt (list xpt ypt LevelElev))
     ; add to mesh 
     (command npnt)
     ; inc ang
     (setq pang (+ pang panginc))
   )
   ; inc elev
   (setq LevelElev (+ LevelElev LevelHeight))
   ; inc radius
   (setq Rad (+ Rad RadInc))
 )
 ; add top
 (setq npnt (list (nth 0 cpnt) (nth 1 cpnt) (- LevelElev LevelHeight)))
 (repeat (+ NumSides 1)
   (command npnt)
 )
 ; set view
 (c:vsw)
 ; hide
 (command ".HIDE")
 (setvar "CMDECHO" 1)
 (princ)
)
;--------------------------------------------------------------------------   
(defun prog61h2 ()
 (graphscr)
 ; tower repeats
 ; Hippopede curve for section
 ; x = (2 * COS t) * SQRT((major radius * minor radius) - (minor radius^2 * SIN t^2))
 ; y = (2 * SIN t) * SQRT((major radius * minor radius) - (minor radius^2 * SIN t^2))
  (setvar "CMDECHO" 0)
 ; center point
 (setq cpnt (list 0.0 0.0 0.0))
 ; get curve parameters
 (princ "\nProg61h2 - Tower")
 (setq TowerLayer  (getstring "\nEnter layer name: "))
 (setq NumLevels   (getint "\nEnter number of levels: "))
 (setq LevelHeight (getdist "\nEnter level height: "))
 (setq NumSides    (getint "\nEnter number of curve sides: "))
 (setq XRadStart   (getdist "\nEnter X radius: "))
 (setq YRadStart   (getreal "\nEnter Y radius start factor: "))
 (setq YRadEnd     (getreal "\nEnter Y radius end factor: ")) 
 ; clear layer
 (command ".LAYER" "THAW" "*" "ON" "*" "")
 (command ".LAYER" "MAKE" TowerLayer "")
 (command ".LAYER" "SET" 0 "")
 (command ".LAYER" "OFF" "@*" "FREEZE" "@*" "")
 (command ".LAYER" "THAW" TowerLayer "ON" TowerLayer "SET" TowerLayer "")
 (command ".ERASE" "ALL" "")
 ; set elev
 (setq LevelElev 0.0)
 ; start mesh 
 (command ".3DMESH" (+ (+ NumLevels 1) 2) (+ NumSides 1))
 ; add bottom
 (setq npnt cpnt) 
 (repeat (+ NumSides 1)
   (command npnt)
 )
 ; radius inc
 (setq YRadInc (/ (- YRadEnd YRadStart) NumLevels)) 
 (setq YRadFact YRadStart)
 ; create each level 
 (repeat (+ NumLevels 1)
   ; draw polygon
   (setq panginc (/ 360.0 NumSides))
   (setq pang 0.0)
   (repeat (+ NumSides 1)
     ; compute point
     (setq Xrad (/ XRadStart 2)) 
     (setq YRad (* YRadFact XRad))     
     (setq xpt (* (* 2 (cos (dtr pang)))
		     (sqrt (- (* XRad YRad) (* (expt YRad 2) (expt (sin (dtr pang)) 2))))))
     (setq ypt (* (* 2 (sin (dtr pang)))
		     (sqrt (- (* XRad YRad) (* (expt YRad 2) (expt (sin (dtr pang)) 2))))))
     (setq npnt (list xpt ypt LevelElev))
     ; add to mesh 
     (command npnt)
     ; inc ang
     (setq pang (+ pang panginc))
   )
   ; inc elev
   (setq LevelElev (+ LevelElev LevelHeight))
   ; inc radius
   (setq YRadFact (+ YRadFact YRadInc))
 )
 ; add top
 (setq npnt (list (nth 0 cpnt) (nth 1 cpnt) (- LevelElev LevelHeight)))
 (repeat (+ NumSides 1)
   (command npnt)
 )
 ; set view
 (c:vsw)
 ; hide
 (command ".HIDE")
 (setvar "CMDECHO" 1)
 (princ)
)
;--------------------------------------------------------------------------   
(defun prog61h2a ()
 (graphscr)
 ; tower repeats
 ; Hippopede curve for section
 ; x = (2 * COS t) * SQRT((major radius * minor radius) - (minor radius^2 * SIN t^2))
 ; y = (2 * SIN t) * SQRT((major radius * minor radius) - (minor radius^2 * SIN t^2))
 ; with rotation  
  (setvar "CMDECHO" 0)
 ; center point
 (setq cpnt (list 0.0 0.0 0.0))
 ; get curve parameters
 (princ "\nProg61h2 - Tower")
 (setq TowerLayer  (getstring "\nEnter layer name: "))
 (setq NumLevels   (getint "\nEnter number of levels: "))
 (setq LevelHeight (getdist "\nEnter level height: "))
 (setq NumSides    (getint "\nEnter number of curve sides: "))
 (setq XRadStart   (getdist "\nEnter X radius: "))
 (setq YRadStart   (getreal "\nEnter Y radius start factor: "))
 (setq YRadEnd     (getreal "\nEnter Y radius end factor: ")) 
 (setq RotTotal    (getreal "\nEnter total rotation angle: "))
 ; clear layer
 (command ".LAYER" "THAW" "*" "ON" "*" "")
 (command ".LAYER" "MAKE" TowerLayer "")
 (command ".LAYER" "SET" 0 "")
 (command ".LAYER" "OFF" "@*" "FREEZE" "@*" "")
 (command ".LAYER" "THAW" TowerLayer "ON" TowerLayer "SET" TowerLayer "")
 (command ".ERASE" "ALL" "")
 ; set elev
 (setq LevelElev 0.0)
 ; start mesh 
 (command ".3DMESH" (+ (+ NumLevels 1) 2) (+ NumSides 1))
 ; add bottom
 (setq npnt cpnt) 
 (repeat (+ NumSides 1)
   (command npnt)
 )
 ; rotation inc
 (setq RotInc (/ RotTotal NumLevels)) 
 (setq Rotang 0.0)  
 ; radius inc
 (setq YRadInc (/ (- YRadEnd YRadStart) NumLevels)) 
 (setq YRadFact YRadStart)
 ; create each level 
 (repeat (+ NumLevels 1)
   ; draw polygon
   (setq panginc (/ 360.0 NumSides))
   (setq pang 0.0)
   (repeat (+ NumSides 1)
     ; compute point
     (setq Xrad (/ XRadStart 2)) 
     (setq YRad (* YRadFact XRad))     
     (setq xpt (* (* 2 (cos (dtr pang)))
		     (sqrt (- (* XRad YRad) (* (expt YRad 2) (expt (sin (dtr pang)) 2))))))
     (setq ypt (* (* 2 (sin (dtr pang)))
		     (sqrt (- (* XRad YRad) (* (expt YRad 2) (expt (sin (dtr pang)) 2))))))
     ; rotate
     (setq rxpt (- (* xpt (cos (dtr Rotang))) (* ypt (sin (dtr Rotang)))))
     (setq rypt (+ (* xpt (sin (dtr Rotang))) (* ypt (cos (dtr Rotang))))) 
     (setq npnt (list rxpt rypt LevelElev))
     ; add to mesh 
     (command npnt)
     ; inc ang
     (setq pang (+ pang panginc))
   )
   ; inc elev
   (setq LevelElev (+ LevelElev LevelHeight))
   ; inc radius
   (setq YRadFact (+ YRadFact YRadInc))
   ; inc rotation
   (setq Rotang (+ Rotang Rotinc))
 )
 ; add top
 (setq npnt (list (nth 0 cpnt) (nth 1 cpnt) (- LevelElev LevelHeight)))
 (repeat (+ NumSides 1)
   (command npnt)
 )
 ; set view
 (c:vsw)
 ; hide
 (command ".HIDE")
 (setvar "CMDECHO" 1)
 (princ)
)
;--------------------------------------------------------------------------   
(defun prog61h3 ()
 (graphscr)
 ; tower repeats
 ; Curve of convexities curve for section
 ; r = (1.0 + ((e * (cos t * pedals))) /  p 
 ; x = (r * radius) * cos t
 ; y = (r * radius) * sin t
  (setvar "CMDECHO" 0)
 ; center point
 (setq cpnt (list 0.0 0.0 0.0))
 ; get curve parameters
 (princ "\nProg61h3 - Tower")
 (setq TowerLayer  (getstring "\nEnter layer name: "))
 (setq NumLevels   (getint "\nEnter number of levels: "))
 (setq LevelHeight (getdist "\nEnter level height: "))
 (setq NumSides    (getint "\nEnter number of curve sides: "))
 (setq Rad         (getdist "\nEnter radius: "))
 (setq NumPedals   (getint "\nEnter number of pedals: "))
 (setq cfactStart  (getreal "\nEnter curve factor start: "))
 (setq cfactEnd    (getreal "\nEnter curve factor end: ")) 
 ; clear layer
 (command ".LAYER" "THAW" "*" "ON" "*" "")
 (command ".LAYER" "MAKE" TowerLayer "")
 (command ".LAYER" "SET" 0 "")
 (command ".LAYER" "OFF" "@*" "FREEZE" "@*" "")
 (command ".LAYER" "THAW" TowerLayer "ON" TowerLayer "SET" TowerLayer "")
 (command ".ERASE" "ALL" "")
 ; set elev
 (setq LevelElev 0.0)
 ; start mesh 
 (command ".3DMESH" (+ (+ NumLevels 1) 2) (+ NumSides 1))
 ; add bottom
 (setq npnt cpnt) 
 (repeat (+ NumSides 1)
   (command npnt)
 )
 ; radius inc
 (setq cfactInc (/ (- cfactEnd cfactStart) NumLevels)) 
 (setq cfact cfactStart)
 ; create each level 
 (repeat (+ NumLevels 1)
   ; draw polygon
   (setq panginc (/ 360.0 NumSides))
   (setq pang 0.0)
   (repeat (+ NumSides 1)
     ; compute point
     (setq r (+ 1.0  (* cfact (cos (* (dtr pang) NumPedals)))))
     (setq xpt (* (* r (* Rad 0.62)) (cos (dtr pang))))
     (setq ypt (* (* r (* Rad 0.62)) (sin (dtr pang))))
     (setq npnt (list xpt ypt LevelElev))
     ; add to mesh 
     (command npnt)
     ; inc ang
     (setq pang (+ pang panginc))
   )
   ; inc elev
   (setq LevelElev (+ LevelElev LevelHeight))
   ; inc radius
   (setq cfact (+ cfact cfactInc))
 )
 ; add top
 (setq npnt (list (nth 0 cpnt) (nth 1 cpnt) (- LevelElev LevelHeight)))
 (repeat (+ NumSides 1)
   (command npnt)
 )
 ; set view
 (c:vsw)
 ; hide
 (command ".HIDE")
 (setvar "CMDECHO" 1)
 (princ)
)
;--------------------------------------------------------------------------   
(defun prog61i ()
 (graphscr)
 ; tower repeats
 (setvar "CMDECHO" 0)
 ; center point
 (setq cpnt (list 0.0 0.0 0.0))
 ; get curve parameters
 (princ "\nProg61i - Tower")
 (setq TowerLayer  (getstring "\nEnter layer name: "))
 (setq NumLevels   (getint "\nEnter number of levels: "))
 (setq LevelHeight (getdist "\nEnter level height: "))
 (setq NumSides    (getint "\nEnter number of polygon sides: "))
 (setq AngSides    (getreal "\nEnter total angle for polygon: "))  
 (setq Rad         (getdist "\nEnter radius: "))
 (setq RotTotal    (getreal "\nEnter total rotation angle: "))
 ; clear layer
 (command ".LAYER" "THAW" "*" "ON" "*" "")
 (command ".LAYER" "MAKE" TowerLayer "")
 (command ".LAYER" "SET" 0 "")
 (command ".LAYER" "OFF" "@*" "FREEZE" "@*" "")
 (command ".LAYER" "THAW" TowerLayer "ON" TowerLayer "SET" TowerLayer "")
 (command ".ERASE" "ALL" "")
 ; set elev
 (setq LevelElev 0.0)
 ; start mesh 
 (command ".3DMESH" (+ (+ NumLevels 1) 2) (+ NumSides 3))
 ; add bottom
 (setq npnt cpnt) 
 (repeat (+ NumSides 3)
   (command npnt)
 )
 ; rotation inc
 (setq RotInc (/ RotTotal NumLevels)) 
 (setq Rotang 0.0)  
 ; create each level 
 (repeat (+ NumLevels 1)
   ; first center pt
   (setq fpnt (list (nth 0 cpnt) (nth 1 cpnt) LevelElev))
   (command fpnt)
   ; draw polygon
   (setq panginc (/ AngSides NumSides))
   (setq pang (+ (/ panginc 2.0) Rotang))
   (repeat (+ NumSides 1)
     ; compute point
     (setq xpt (+ (nth 0 cpnt) (* Rad (sin (dtr pang)))))
     (setq ypt (+ (nth 1 cpnt) (* Rad (cos (dtr pang)))))
     (setq npnt (list xpt ypt LevelElev))
     ; add to mesh 
     (command npnt)
     ; inc ang
     (setq pang (+ pang panginc))
   )
   ; back to first pt
   (command fpnt)
   ; inc elev
   (setq LevelElev (+ LevelElev LevelHeight))
   ; inc rotation
   (setq Rotang (+ Rotang Rotinc))
 )
 ; add top
 (setq npnt (list (nth 0 cpnt) (nth 1 cpnt) (- LevelElev LevelHeight)))
 (repeat (+ NumSides 3)
   (command npnt)
 )
 ; set view
 (c:vsw)
 ; hide
 (command ".HIDE")
 (setvar "CMDECHO" 1)
 (princ)
)
;--------------------------------------------------------------------------   
(defun prog61j ()
 (graphscr)
 ; tower repeats
 (setvar "CMDECHO" 0)
 ; center point
 (setq cpnt (list 0.0 0.0 0.0))
 ; get curve parameters
 (princ "\nProg61j - Tower")
 (setq TowerLayer  (getstring "\nEnter layer name: "))
 (setq NumLevels   (getint "\nEnter number of levels: "))
 (setq LevelHeight (getdist "\nEnter level height: "))
 (setq NumSides    (getint "\nEnter number of polygon sides: "))
 (setq AngStart    (getreal "\nEnter start angle for polygon: "))  
 (setq AngEnd      (getreal "\nEnter end angle for polygon: "))  
 (setq Rad         (getdist "\nEnter radius: "))
 ; clear layer
 (command ".LAYER" "THAW" "*" "ON" "*" "")
 (command ".LAYER" "MAKE" TowerLayer "")
 (command ".LAYER" "SET" 0 "")
 (command ".LAYER" "OFF" "@*" "FREEZE" "@*" "")
 (command ".LAYER" "THAW" TowerLayer "ON" TowerLayer "SET" TowerLayer "")
 (command ".ERASE" "ALL" "")
 ; set elev
 (setq LevelElev 0.0)
 ; start mesh 
 (command ".3DMESH" (+ (+ NumLevels 1) 2) (+ NumSides 3))
 ; add bottom
 (setq npnt cpnt) 
 (repeat (+ NumSides 3)
   (command npnt)
 )
 ; poyglon ag inc
 (setq AngInc (/ (- AngStart AngEnd) NumLevels)) 
 (setq Polyang AngStart)  
 ; create each level 
 (repeat (+ NumLevels 1)
   ; first center pt
   (setq fpnt (list (nth 0 cpnt) (nth 1 cpnt) LevelElev))
   (command fpnt)
   ; draw polygon
   (setq panginc (/ Polyang NumSides))
   (setq pang 0.0)
   (repeat (+ NumSides 1)
     ; compute point
     (setq xpt (+ (nth 0 cpnt) (* Rad (sin (dtr pang)))))
     (setq ypt (+ (nth 1 cpnt) (* Rad (cos (dtr pang)))))
     (setq npnt (list xpt ypt LevelElev))
     ; add to mesh 
     (command npnt)
     ; inc ang
     (setq pang (+ pang panginc))
   )
   ; back to first pt
   (command fpnt)
   ; inc elev
   (setq LevelElev (+ LevelElev LevelHeight))
   ; inc ploygon ang
   (setq Polyang (- Polyang AngInc))
 )
 ; add top
 (setq npnt (list (nth 0 cpnt) (nth 1 cpnt) (- LevelElev LevelHeight)))
 (repeat (+ NumSides 3)
   (command npnt)
 )
 ; set view
 (c:vsw)
 ; hide
 (command ".HIDE")
 (setvar "CMDECHO" 1)
 (princ)
)
;--------------------------------------------------------------------------   
(defun prog61k ()
 (graphscr)
 ; tower repeats
 ; morph from lists of points
 (setvar "CMDECHO" 0)
 ; center point
 (setq cpnt (list 0.0 0.0 0.0))
 ; get curve parameters
 (princ "\nProg61k - Tower")
 (setq TowerLayer  (getstring "\nEnter layer name: "))
 (setq NumLevels   (getint "\nEnter number of levels: "))
 (setq LevelHeight (getdist "\nEnter level height: "))
 (setq BotSect     (read (getstring "\nEnter bottom list of points: ")))
 (setq RotTotal    (getreal "\nEnter total rotation angle: "))
 ; clear layer
 (command ".LAYER" "THAW" "*" "ON" "*" "")
 (command ".LAYER" "MAKE" TowerLayer "")
 (command ".LAYER" "SET" 0 "")
 (command ".LAYER" "OFF" "@*" "FREEZE" "@*" "")
 (command ".LAYER" "THAW" TowerLayer "ON" TowerLayer "SET" TowerLayer "")
 (command ".ERASE" "ALL" "")
 ; set elev
 (setq LevelElev 0.0)
 ; rotation inc
 (setq RotInc (/ RotTotal NumLevels)) 
 (setq Rotang 0.0)  
 ; points
 (setq npts (length BotSect)) 
 ; start mesh 
 (command ".3DMESH" (+ (+ NumLevels 1) 2) npts)
 ; add bottom
 (setq npnt cpnt) 
 (repeat npts
   (command npnt)
 )
 ; create each level
 (setq nlevel 0) 
 (repeat (+ NumLevels 1)
   (setq npt 0)
   (repeat npts
     ; get point
     (setq xpt (* 12 (nth 0 (nth npt BotSect))))
     (setq ypt (* 12 (nth 1 (nth npt BotSect))))
     ; rotate
     (setq rxpt (- (* xpt (cos (dtr Rotang))) (* ypt (sin (dtr Rotang)))))
     (setq rypt (+ (* xpt (sin (dtr Rotang))) (* ypt (cos (dtr Rotang))))) 
     (setq npnt (list rxpt rypt LevelElev))
     ; add to mesh 
     (command npnt)
     ; next pt
     (setq npt (+ npt 1))
   )
   ; inc elev
   (setq LevelElev (+ LevelElev LevelHeight))
   (setq nlevel (+ nlevel 1))
   ; inc rotation
   (setq Rotang (+ Rotang Rotinc))
 )
 ; add top
 (setq npnt (list (nth 0 cpnt) (nth 1 cpnt) (- LevelElev LevelHeight)))
 (repeat npts
   (command npnt)
 )
 ; set view
 (c:vsw)
 ; hide
 (command ".HIDE")
 (setvar "CMDECHO" 1)
 (princ)
)
;--------------------------------------------------------------------------   
(defun prog61l ()
 (graphscr)
 ; tower repeats
 ; morph from lists of points
 (setvar "CMDECHO" 0)
 ; center point
 (setq cpnt (list 0.0 0.0 0.0))
 ; get curve parameters
 (princ "\nProg61k - Tower")
 (setq TowerLayer  (getstring "\nEnter layer name: "))
 (setq NumLevels   (getint "\nEnter number of levels: "))
 (setq LevelHeight (getdist "\nEnter level height: "))
 (setq BotSect     (read (getstring "\nEnter bottom list of points: ")))
 (setq TopSect     (read (getstring "\nEnter top list of points: ")))
 ; clear layer
 (command ".LAYER" "THAW" "*" "ON" "*" "")
 (command ".LAYER" "MAKE" TowerLayer "")
 (command ".LAYER" "SET" 0 "")
 (command ".LAYER" "OFF" "@*" "FREEZE" "@*" "")
 (command ".LAYER" "THAW" TowerLayer "ON" TowerLayer "SET" TowerLayer "")
 (command ".ERASE" "ALL" "")
 ; set elev
 (setq LevelElev 0.0)
 ; points
 (setq npts (length BotSect)) 
 ; start mesh 
 (command ".3DMESH" (+ (+ NumLevels 1) 2) npts)
 ; add bottom
 (setq npnt cpnt) 
 (repeat npts
   (command npnt)
 )
 ; create each level
 (setq nlevel 0) 
 (repeat (+ NumLevels 1)
   (setq npt 0)
   (repeat npts
     ; get point
     (setq xpt (nth 0 (nth npt BotSect)))
     (setq ypt (nth 1 (nth npt BotSect)))
     ; compute inc
     (setq xinc (/ (- (nth 0 (nth npt TopSect)) (nth 0 (nth npt BotSect))) NumLevels))
     (setq yinc (/ (- (nth 1 (nth npt TopSect)) (nth 1 (nth npt BotSect))) NumLevels))
     ; add to pt
     (setq npnt (list (+ (* xpt 12) (* (* xinc 12) nlevel))
		      (+ (* ypt 12) (* (* yinc 12) nlevel)) LevelElev))
     ; add to mesh 
     (command npnt)
     ; next pt
     (setq npt (+ npt 1))
   )
   ; inc elev
   (setq LevelElev (+ LevelElev LevelHeight))
   (setq nlevel (+ nlevel 1))
 )
 ; add top
 (setq npnt (list (nth 0 cpnt) (nth 1 cpnt) (- LevelElev LevelHeight)))
 (repeat npts
   (command npnt)
 )
 ; set view
 (c:vsw)
 ; hide
 (command ".HIDE")
 (setvar "CMDECHO" 1)
 (princ)
)
; --------------------------------------------------------------------------
; --------------------------------------------------------------------------
;----------------------------------------------------------------------------
;----------------------------------------------------------------------------
; load solid modelling DLL
(arxload "geom3d")
;----------------------------------------------------------------------------