; The Codewriting Workbook
; Creating Computational Architecture in AutoLISP
; by Robert J. Krawczyk
; Princeton Architectural Press, 2008
; --------------------------------------------------------------------------
; CH06C.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 sign (a) (if (< a 0.0) (- 0 1.0) (+ 0 1.0)))
; --------------------------------------------------------------------------
(defun rn (/ modulus multiplier increment random)
  (if (not rnseed) (setq rnseed (getvar "DATE")))
  (setq modulus 65536
   multiplier 25173
   increment  13849
   rnseed (rem (+ (* multiplier rnseed) increment) modulus)
   random  (/ rnseed modulus)
  )
)
;---------------------------------------------------------------------------
; --------------------------------------------------------------------------
(defun rotate2d ( pt ptc ang / pt1 pt2 )
  ; rotate pt ang degrees
  (setq pt1 (list (+ (nth 0 pt) (- 0 (nth 0 ptc))) (+ (nth 1 pt) (- 0 (nth 1 ptc))) (nth 2 pt)))
  (setq pt2 (list (- (* (nth 0 pt1) (cos (dtr ang))) (* (nth 1 pt1) (sin (dtr ang))))
  (+ (* (nth 0 pt1) (sin (dtr ang))) (* (nth 1 pt1) (cos (dtr ang))))
  	  (nth 2 pt)))
  (list (+ (nth 0 pt2) (+ 0 (nth 0 ptc))) (+ (nth 1 pt2) (+ 0 (nth 1 ptc))) (nth 2 pt))
)  
;---------------------------------------------------------------------------
;---------------------------------------------------------------------------
; ZW - zoom window
(defun c:zw ()
 (command "zoom" "w")
)
; ZP - zoom previous
(defun c:zp ()
 (command "zoom" "p") 
) 
; ZE - zoom extents
(defun c:ze ()
 (command "zoom" "e" "zoom" ".9x")
)
; ZX - zoom .9x  
(defun c:zx ()
  (command "zoom" ".9x")
)
;---------------------------------------------------------------------------
; 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)
)
;--------------------------------------------------------------------------
;--------------------------------------------------------------------------
;--------------------------------------------------------------------------
(defun prog01 ()
 (graphscr)
 (command ".ERASE" "all" "") 
 ; set start point
 (setq pnt0 (list 0 0 0))
 (setq xyside (getdist pnt0 "\nEnter XY side:"))
 (setq xtimes (getint "\nEnter number X repeats:"))
 (setq ytimes (getint "\nEnter number Y repeats:"))
 (setq cradmin   (getdist "\nEnter min radius: "))
 (setq cradmax   (getdist "\nEnter max radius: "))
 ; start y location
 (setq yloc (nth 0 pnt0))
 (repeat ytimes 
   ; start x location
   (setq xloc (nth 1 pnt0))
   (repeat xtimes
     ; lower corner pt
     (setq pnt1 (list xloc yloc (nth 2 pnt0)))
     ; center of square
     (setq pnt2 (list (+ (nth 0 pnt1) (/ xyside 2)) (+ (nth 1 pnt1) (/ xyside 2)) (nth 2 pnt1)))
     ; compute radius
     (setq crad (+ cradmin (* (rn) (- cradmax cradmin))))
     ; draw circle
     (command ".CIRCLE" pnt2 crad)
     (command ".ZOOM" "e") 
     ; convert to region
     (command ".REGION" "last" "")
     ; inc x location
     (setq xloc (+ xloc xyside))
   )
   ; inc y location
   (setq yloc (+ yloc xyside))
   (command ".ZOOM" "e")
 )
 ; surface to be perforated
 (setq xmax (* xyside xtimes))
 (setq ymax (* xyside ytimes))
 (setq pnt1 (list (+ (nth 0 pnt0) xmax) (+ (nth 1 pnt0) ymax)))
 (command ".RECTANGLE" pnt0 pnt1)
 (command ".ZOOM" "e") 
 ; convert to region
 (command ".REGION" "last" "")
 ; subtract openings
 (command ".SUBTRACT" "last" "" "all" "") 
 (princ)  
)
;--------------------------------------------------------------------------
;--------------------------------------------------------------------------
(defun prog02 ()
 (graphscr)
 ; random sticks
 (setq pnt0 (list 0 0 0))
 (setq xside  (getdist pnt0 "\nEnter X side panel:"))
 (setq yside  (getdist pnt0 "\nEnter Y side panel:"))
 (setq xtimes (getint "\nEnter number of X panels:"))
 (setq ytimes (getint "\nEnter number of Y panels:"))
 (setq xmin   (getdist pnt0 "\nEnter X min rectangle:"))
 (setq xmax   (getdist pnt0 "\nEnter X max rectangle:"))
 (setq ymin   (getdist pnt0 "\nEnter Y min rectangle:"))
 (setq ymax   (getdist pnt0 "\nEnter Y max rectangle:"))
 (setq xyoff  (getdist pnt0 "\nEnter XY offset:"))
 (setq rotang (getreal "\nEnter rotation angle:")) 
 (command ".ERASE" "all" "")
 ; start y location
 (setq ypos (+ (nth 1 pnt0) (/ yside 2)))
 (repeat ytimes 
   ; start x location
   (setq xpos (+ (nth 0 pnt0) (/ xside 2)))
   (repeat xtimes
     ; random stick size, offset, and rotation
     (setq xrside (+ xmin (* (rn) (- xmax xmin)))) 
     (setq yrside (+ ymin (* (rn) (- ymax ymin)))) 
     (setq xoff (* (rn) xyoff)) 
     (setq yoff (* (rn) xyoff))
     (setq rang (* (rn) rotang))
     ; center pt 
     (setq pntc (list (+ (- xpos (/ xyoff 2)) xoff) (+ (- ypos (/ xyoff 2)) yoff) 0.0))
     ; stick 
     (setq pnt1 (list (- (nth 0 pntc) (/ xrside 2)) (- (nth 1 pntc) (/ yrside 2)) 0.0))
     (setq pnt2 (list (+ (nth 0 pntc) (/ xrside 2)) (- (nth 1 pntc) (/ yrside 2)) 0.0))
     (setq pnt3 (list (+ (nth 0 pntc) (/ xrside 2)) (+ (nth 1 pntc) (/ yrside 2)) 0.0))
     (setq pnt4 (list (- (nth 0 pntc) (/ xrside 2)) (+ (nth 1 pntc) (/ yrside 2)) 0.0))
     (command ".PLINE" pnt1 pnt2 pnt3 pnt4 pnt1 "")
     (command ".ZOOM" "e") 
     (command ".REGION" "last" "")
     (command ".ROTATE" "last" "" pntc rang) 
     ; inc x
     (setq xpos (+ xpos xside))
   )
   ; inc y
   (setq ypos (+ ypos yside))
 )
 ; union regions  
 (command ".UNION" "all" "")  
 ; border
 (setq xmax (* xside xtimes))
 (setq ymax (* yside ytimes))
 (setq pnt1 (list (+ (nth 0 pnt0) xmax) (+ (nth 1 pnt0) ymax)))
 (command ".RECTANGLE" pnt0 pnt1)
 (command ".ZOOM" "e")  
 (princ)
)
;--------------------------------------------------------------------------
(defun prog02a ()
 (graphscr)
 ; random sticks
 (setq pnt0 (list 0 0 0))
 (setq xside  (getdist pnt0 "\nEnter X side panel:"))
 (setq yside  (getdist pnt0 "\nEnter Y side panel:"))
 (setq xtimes (getint "\nEnter number of X panels:"))
 (setq ytimes (getint "\nEnter number of Y panels:"))
 (setq xmin   (getdist pnt0 "\nEnter X min rectangle:"))
 (setq xmax   (getdist pnt0 "\nEnter X max rectangle:"))
 (setq ymin   (getdist pnt0 "\nEnter Y min rectangle:"))
 (setq ymax   (getdist pnt0 "\nEnter Y max rectangle:"))
 (setq xyoff  (getdist pnt0 "\nEnter XY offset:"))
 (setq rotang (getreal "\nEnter rotation angle:")) 
 (command ".ERASE" "all" "")
 ; start y location
 (setq ypos (+ (nth 1 pnt0) (/ yside 2)))
 (repeat ytimes 
   ; start x location
   (setq xpos (+ (nth 0 pnt0) (/ xside 2)))
   (repeat xtimes
     ; random stick size, offset, and rotation
     (setq xrside (+ xmin (* (rn) (- xmax xmin)))) 
     (setq yrside (+ ymin (* (rn) (- ymax ymin)))) 
     (setq xoff (* (rn) xyoff)) 
     (setq yoff (* (rn) xyoff))
     (setq rang (* (rn) rotang))
     ; center pt 
     (setq pntc (list (+ (- xpos (/ xyoff 2)) xoff) (+ (- ypos (/ xyoff 2)) yoff) 0.0))
     ; stick 
     (setq pnt1 (list (- (nth 0 pntc) (/ xrside 2)) (- (nth 1 pntc) (/ yrside 2)) 0.0))
     (setq pnt2 (list (+ (nth 0 pntc) (/ xrside 2)) (- (nth 1 pntc) (/ yrside 2)) 0.0))
     (setq pnt3 (list (+ (nth 0 pntc) (/ xrside 2)) (+ (nth 1 pntc) (/ yrside 2)) 0.0))
     (setq pnt4 (list (- (nth 0 pntc) (/ xrside 2)) (+ (nth 1 pntc) (/ yrside 2)) 0.0))
     (command ".PLINE" pnt1 pnt2 pnt3 pnt4 pnt1 "")
     (command ".ZOOM" "e") 
     (command ".REGION" "last" "")
     (command ".ROTATE" "last" "" pntc rang) 
     ; inc x
     (setq xpos (+ xpos xside))
   )
   ; inc y
   (setq ypos (+ ypos yside))
 )
 ; union regions  
 (command ".UNION" "all" "")
 (setq obj1 (ssadd (entlast))) 
 ; inside border
 (setq xmax (* xside xtimes))
 (setq ymax (* yside ytimes))
 (setq pnt1 (list (+ (nth 0 pnt0) xmax) (+ (nth 1 pnt0) ymax)))
 (command ".RECTANGLE" pnt0 pnt1)
 (command ".ZOOM" "e") 
 (command ".REGION" "last" "")
 (setq obj2 (ssadd (entlast)))
 ; outside border
 (setq pnt2 (list (- (nth 0 pnt0) xmax) (- (nth 1 pnt0) ymax)))   
 (setq pnt3 (list (+ (nth 0 pnt1) xmax) (+ (nth 1 pnt1) ymax)))     
 (command ".RECTANGLE" pnt2 pnt3)
 (command ".ZOOM" "e") 
 (command ".REGION" "last" "")
 (setq obj3 (ssadd (entlast)))
 ; make border      
 (command ".SUBTRACT" obj3 "" obj2 "")
 (setq obj2 (ssadd (entlast)))
 ; subtract border from panel
 (command ".SUBTRACT" obj1 "" obj2 "")
 (command ".ZOOM" "e")  
 (princ)
)
;--------------------------------------------------------------------------
(defun prog02b ()
 (graphscr)
 ; random sticks
 (setq pnt0 (list 0 0 0))
 (setq xside  (getdist pnt0 "\nEnter X side panel:"))
 (setq yside  (getdist pnt0 "\nEnter Y side panel:"))
 (setq xtimes (getint "\nEnter number of X panels:"))
 (setq ytimes (getint "\nEnter number of Y panels:"))
 (setq xmin   (getdist pnt0 "\nEnter X min rectangle:"))
 (setq xmax   (getdist pnt0 "\nEnter X max rectangle:"))
 (setq ymin   (getdist pnt0 "\nEnter Y min rectangle:"))
 (setq ymax   (getdist pnt0 "\nEnter Y max rectangle:"))
 (setq xyoff  (getdist pnt0 "\nEnter XY offset:"))
 (setq rotang (getreal "\nEnter rotation angle:")) 
 (command ".ERASE" "all" "")
 ; start y location
 (setq ypos (+ (nth 1 pnt0) (/ yside 2)))
 (repeat ytimes 
   ; start x location
   (setq xpos (+ (nth 0 pnt0) (/ xside 2)))
   (repeat xtimes
     ; random stick size, offset, and rotation
     (setq xrside (+ xmin (* (rn) (- xmax xmin)))) 
     (setq yrside (+ ymin (* (rn) (- ymax ymin)))) 
     (setq xoff (* (rn) xyoff)) 
     (setq yoff (* (rn) xyoff))
     (setq rang (* (rn) rotang))
     ; center pt 
     (setq pntc (list (+ (- xpos (/ xyoff 2)) xoff) (+ (- ypos (/ xyoff 2)) yoff) 0.0))
     ; stick 
     (setq pnt1 (list (- (nth 0 pntc) (/ xrside 2)) (- (nth 1 pntc) (/ yrside 2)) 0.0))
     (setq pnt2 (list (+ (nth 0 pntc) (/ xrside 2)) (- (nth 1 pntc) (/ yrside 2)) 0.0))
     (setq pnt3 (list (+ (nth 0 pntc) (/ xrside 2)) (+ (nth 1 pntc) (/ yrside 2)) 0.0))
     (setq pnt4 (list (- (nth 0 pntc) (/ xrside 2)) (+ (nth 1 pntc) (/ yrside 2)) 0.0))
     (command ".PLINE" pnt1 pnt2 pnt3 pnt4 pnt1 "")
     (command ".ZOOM" "e") 
     (command ".REGION" "last" "")
     (command ".ROTATE" "last" "" pntc rang) 
     ; inc x
     (setq xpos (+ xpos xside))
   )
   ; inc y
   (setq ypos (+ ypos yside))
 )
 ; union regions  
 (command ".UNION" "all" "")
 (setq obj1 (ssadd (entlast))) 
 ; inside border
 (setq xmax (* xside xtimes))
 (setq ymax (* yside ytimes))
 (setq pnt1 (list (+ (nth 0 pnt0) xmax) (+ (nth 1 pnt0) ymax)))
 (command ".RECTANGLE" pnt0 pnt1)
 (command ".ZOOM" "e") 
 (command ".REGION" "last" "")
 (setq obj2 (ssadd (entlast)))
 ; outside border
 (setq pnt2 (list (- (nth 0 pnt0) xmax) (- (nth 1 pnt0) ymax)))   
 (setq pnt3 (list (+ (nth 0 pnt1) xmax) (+ (nth 1 pnt1) ymax)))     
 (command ".RECTANGLE" pnt2 pnt3)
 (command ".ZOOM" "e") 
 (command ".REGION" "last" "")
 (setq obj3 (ssadd (entlast)))
 ; make border      
 (command ".SUBTRACT" obj3 "" obj2 "")
 (setq obj2 (ssadd (entlast)))
 ; subtract border from panel
 (command ".SUBTRACT" obj1 "" obj2 "")
 (setq obj1 (ssadd (entlast)))
 ; make frame at border
 ; inside border
 (setq pnt1 (list xmax ymax))
 (command ".RECTANGLE" pnt0 pnt1)
 (command ".ZOOM" "e") 
 (command ".REGION" "last" "")
 (setq obj2 (ssadd (entlast)))
 ; outside border
 (setq pnt2 (list (- (nth 0 pnt0) 1) (- (nth 1 pnt0) 1)))   
 (setq pnt3 (list (+ (nth 0 pnt1) 1) (+ (nth 1 pnt1) 1)))     
 (command ".RECTANGLE" pnt2 pnt3)
 (command ".ZOOM" "e") 
 (command ".REGION" "last" "")
 (setq obj3 (ssadd (entlast)))
 ; make frame      
 (command ".SUBTRACT" obj3 "" obj2 "")
 (setq obj2 (ssadd (entlast)))
 ; add to panel
 (command ".UNION" "all" "") 
 (command ".ZOOM" "e") 
 (princ)
)
;--------------------------------------------------------------------------
(defun prog02c ()
 (graphscr)
 ; random sticks
 (setq pnt0 (list 0 0 0))
 (setq xside  (getdist pnt0 "\nEnter X side panel:"))
 (setq yside  (getdist pnt0 "\nEnter Y side panel:"))
 (setq xtimes (getint "\nEnter number of X panels:"))
 (setq ytimes (getint "\nEnter number of Y panels:"))
 (setq xmin   (getdist pnt0 "\nEnter X min rectangle:"))
 (setq xmax   (getdist pnt0 "\nEnter X max rectangle:"))
 (setq ymin   (getdist pnt0 "\nEnter Y min rectangle:"))
 (setq ymax   (getdist pnt0 "\nEnter Y max rectangle:"))
 (setq xyoff  (getdist pnt0 "\nEnter XY offset:"))
 (setq rotang (getreal "\nEnter rotation angle:")) 
 (command ".ERASE" "all" "")
 ; start y location
 (setq ypos (+ (nth 1 pnt0) (/ yside 2)))
 (repeat ytimes 
   ; start x location
   (setq xpos (+ (nth 0 pnt0) (/ xside 2)))
   (repeat xtimes
     ; random stick size, offset, and rotation
     (setq xrside (+ xmin (* (rn) (- xmax xmin)))) 
     (setq yrside (+ ymin (* (rn) (- ymax ymin)))) 
     (setq xoff (* (rn) xyoff)) 
     (setq yoff (* (rn) xyoff))
     (setq rang (* (rn) rotang))
     ; center pt 
     (setq pntc (list (+ (- xpos (/ xyoff 2)) xoff) (+ (- ypos (/ xyoff 2)) yoff) 0.0))
     ; stick 
     (setq pnt1 (list (- (nth 0 pntc) (/ xrside 2)) (- (nth 1 pntc) (/ yrside 2)) 0.0))
     (setq pnt2 (list (+ (nth 0 pntc) (/ xrside 2)) (- (nth 1 pntc) (/ yrside 2)) 0.0))
     (setq pnt3 (list (+ (nth 0 pntc) (/ xrside 2)) (+ (nth 1 pntc) (/ yrside 2)) 0.0))
     (setq pnt4 (list (- (nth 0 pntc) (/ xrside 2)) (+ (nth 1 pntc) (/ yrside 2)) 0.0))
     (command ".PLINE" pnt1 pnt2 pnt3 pnt4 pnt1 "")
     (command ".ZOOM" "e") 
     (command ".REGION" "last" "")
     (command ".ROTATE" "last" "" pntc rang) 
     ; inc x
     (setq xpos (+ xpos xside))
   )
   ; inc y
   (setq ypos (+ ypos yside))
 )
 ; union regions  
 (command ".UNION" "all" "")
 ; make frame at border
 ; inside border
 (setq xmax (* xside xtimes))
 (setq ymax (* yside ytimes))
 (setq pnt1 (list (+ (nth 0 pnt0) xmax) (+ (nth 1 pnt0) ymax)))
 (command ".RECTANGLE" pnt0 pnt1)
 (command ".ZOOM" "e") 
 (command ".REGION" "last" "")
 (setq obj2 (ssadd (entlast)))
 ; outside border
 (setq pnt2 (list (- (nth 0 pnt0) 1) (- (nth 1 pnt0) 1)))   
 (setq pnt3 (list (+ (nth 0 pnt1) 1) (+ (nth 1 pnt1) 1)))     
 (command ".RECTANGLE" pnt2 pnt3)
 (command ".ZOOM" "e") 
 (command ".REGION" "last" "")
 (setq obj3 (ssadd (entlast)))
 ; make frame      
 (command ".SUBTRACT" obj3 "" obj2 "")
 (setq obj2 (ssadd (entlast)))
 ; add to panel
 (command ".UNION" "all" "") 
 (command ".ZOOM" "e") 
 (princ)
)
;--------------------------------------------------------------------------
(defun prog03 ()
 (graphscr)
 ; ring relief 2D version
 (setq pnt0 (list 0 0 0))
 (setq xside  (getdist pnt0 "\nEnter X side panel:"))
 (setq yside  (getdist pnt0 "\nEnter Y side panel:"))
 (setq xtimes (getint "\nEnter number of X panels:"))
 (setq ytimes (getint "\nEnter number of Y panels:"))
 (setq romin  (getdist pnt0 "\nEnter ring radius outside min:"))
 (setq romax  (getdist pnt0 "\nEnter ring radius outside max:"))
 (setq rsmin  (getdist pnt0 "\nEnter ring size min:"))
 (setq rsmax  (getdist pnt0 "\nEnter ring size max:"))
 (setq xyoff (getdist pnt0 "\nEnter XY offset:"))
 (command ".ERASE" "all" "") 
 ; rectangles panels
 ; start y location
 (setq ypos (+ (nth 1 pnt0) (/ yside 2)))
 (repeat ytimes 
   ; start x location
   (setq xpos (+ (nth 0 pnt0) (/ xside 2)))
   (repeat xtimes
     ; random ring size and offset
     (setq rorad (+ romin (* (rn) (- romax romin)))) 
     (setq risize (+ rsmin (* (rn) (- rsmax rsmin)))) 
     (setq xoff (* (rn) xyoff)) 
     (setq yoff (* (rn) xyoff))
     ; center pt
     (setq pntc (list (+ (- xpos (/ xyoff 2)) xoff) (+ (- ypos (/ xyoff 2)) yoff) 0.0))
     ; make ring
     (command ".CIRCLE" pntc rorad)
     (command ".ZOOM" "e") 
     (command ".REGION" "last" "")
     (setq obj1 (ssadd (entlast))) 
     (command ".CIRCLE" pntc (- rorad risize))
     (command ".ZOOM" "e") 
     (command ".REGION" "last" "") 
     (setq obj2 (ssadd (entlast))) 
     (command ".SUBTRACT" obj1 "" obj2 "")
     ; inc x
     (setq xpos (+ xpos xside))
   )
   ; inc y
   (setq ypos (+ ypos yside))
 )
 ; union regions  
 (command ".UNION" "all" "")
 (setq obj1 (ssadd (entlast))) 
 ; inside border
 (setq xmax (* xside xtimes))
 (setq ymax (* yside ytimes))
 (setq pnt1 (list (+ (nth 0 pnt0) xmax) (+ (nth 1 pnt0) ymax)))
 (command ".RECTANGLE" pnt0 pnt1)
 (command ".ZOOM" "e") 
 (command ".REGION" "last" "")
 (setq obj2 (ssadd (entlast)))
 ; outside border
 (setq pnt2 (list (- (nth 0 pnt0) xmax) (- (nth 1 pnt0) ymax)))   
 (setq pnt3 (list (+ (nth 0 pnt1) xmax) (+ (nth 1 pnt1) ymax)))     
 (command ".RECTANGLE" pnt2 pnt3)
 (command ".ZOOM" "e") 
 (command ".REGION" "last" "")
 (setq obj3 (ssadd (entlast)))
 ; make border      
 (command ".SUBTRACT" obj3 "" obj2 "")
 (setq obj2 (ssadd (entlast)))
 ; subtract border from panel
 (command ".SUBTRACT" obj1 "" obj2 "")
 (command ".ZOOM" "e")  
 (princ)
)
;--------------------------------------------------------------------------
(defun prog03a ()
 (graphscr)
 ; ring relief 2D version
 (setq pnt0 (list 0 0 0))
 (setq xside  (getdist pnt0 "\nEnter X side panel:"))
 (setq yside  (getdist pnt0 "\nEnter Y side panel:"))
 (setq xtimes (getint "\nEnter number of X panels:"))
 (setq ytimes (getint "\nEnter number of Y panels:"))
 (setq romin  (getdist pnt0 "\nEnter ring radius outside min:"))
 (setq romax  (getdist pnt0 "\nEnter ring radius outside max:"))
 (setq rsmin  (getdist pnt0 "\nEnter ring size min:"))
 (setq rsmax  (getdist pnt0 "\nEnter ring size max:"))
 (setq xyoff  (getdist pnt0 "\nEnter XY offset:"))
 (command ".ERASE" "all" "") 
 ;panel size
 (setq xmax (* xside xtimes))
 (setq ymax (* yside ytimes))
 ; start y location
 (setq ypos (+ (nth 1 pnt0) (/ yside 2)))
 (repeat ytimes 
   ; start x location
   (setq xpos (+ (nth 0 pnt0) (/ xside 2)))
   (repeat xtimes
     ; random ring size and offset
     (setq rorad (+ romin (* (rn) (- romax romin)))) 
     (setq risize (+ rsmin (* (rn) (- rsmax rsmin)))) 
     ; center of panel
     (setq cpt (list (+ (nth 0 pnt0) (/ xmax 2.0)) (+ (nth 1 pnt0) (/ ymax 2.0)) (nth 2 pnt0)))  
     ; center pt
     (setq pntc (list xpos ypos (nth 2 pnt0)))
     ; distance to center determines amount of offset
     (setq xdist (abs (- (nth 0 pntc) (nth 0 cpt)))) 
     (setq ydist (abs (- (nth 1 pntc) (nth 1 cpt))))
     (setq xprct (- 1.0 (/ xdist (/ (- xmax xside) 2.0))))
     (setq yprct (- 1.0 (/ ydist (/ (- ymax yside) 2.0))))
     (setq xoff (* (rn) (* xprct xyoff))) 
     (setq yoff (* (rn) (* yprct xyoff)))
     ; redefine center pt
     (setq pntc (list (+ (- xpos (/ (* xyoff xprct) 2)) xoff)
		      (+ (- ypos (/ (* xyoff yprct) 2)) yoff) (nth 2 pnt0)))
     ; make ring
     (command ".CIRCLE" pntc rorad)
     (command ".ZOOM" "e") 
     (command ".REGION" "last" "")
     (setq obj1 (ssadd (entlast))) 
     (command ".CIRCLE" pntc (- rorad risize))
     (command ".ZOOM" "e") 
     (command ".REGION" "last" "") 
     (setq obj2 (ssadd (entlast))) 
     (command ".SUBTRACT" obj1 "" obj2 "")
     ; inc x
     (setq xpos (+ xpos xside))
   )
   ; inc y
   (setq ypos (+ ypos yside))
 )
 ; union regions  
 (command ".UNION" "all" "")
 (setq obj1 (ssadd (entlast))) 
 ; inside border
 (setq pnt1 (list (+ (nth 0 pnt0) xmax) (+ (nth 1 pnt0) ymax)))
 (command ".RECTANGLE" pnt0 pnt1)
 (command ".ZOOM" "e") 
 (command ".REGION" "last" "")
 (setq obj2 (ssadd (entlast)))
 ; outside border
 (setq pnt2 (list (- (nth 0 pnt0) xmax) (- (nth 1 pnt0) ymax)))   
 (setq pnt3 (list (+ (nth 0 pnt1) xmax) (+ (nth 1 pnt1) ymax)))     
 (command ".RECTANGLE" pnt2 pnt3)
 (command ".ZOOM" "e") 
 (command ".REGION" "last" "")
 (setq obj3 (ssadd (entlast)))
 ; make border      
 (command ".SUBTRACT" obj3 "" obj2 "")
 (setq obj2 (ssadd (entlast)))
 ; subtract border from panel
 (command ".SUBTRACT" obj1 "" obj2 "")
 (command ".ZOOM" "e")  
 (princ)
)
;--------------------------------------------------------------------------
(defun prog03b ()
 (graphscr)
 ; ring relief 2D version
 (setq pnt0 (list 0 0 0))
 (setq xside  (getdist pnt0 "\nEnter X side panel:"))
 (setq yside  (getdist pnt0 "\nEnter Y side panel:"))
 (setq xtimes (getint "\nEnter number of X panels:"))
 (setq ytimes (getint "\nEnter number of Y panels:"))
 (setq romin  (getdist pnt0 "\nEnter ring radius outside min:"))
 (setq romax  (getdist pnt0 "\nEnter ring radius outside max:"))
 (setq rsmin  (getdist pnt0 "\nEnter ring size min:"))
 (setq rsmax  (getdist pnt0 "\nEnter ring size max:"))
 (setq xyoff  (getdist pnt0 "\nEnter XY offset:"))
 (setq dfact  (getreal "\nEnter distance factor:"))  
 (command ".ERASE" "all" "") 
 ;panel size
 (setq xmax (* xside xtimes))
 (setq ymax (* yside ytimes))
 ; start y location
 (setq ypos (+ (nth 1 pnt0) (/ yside 2)))
 (repeat ytimes 
   ; start x location
   (setq xpos (+ (nth 0 pnt0) (/ xside 2)))
   (repeat xtimes
     ; random ring size and offset
     (setq rorad (+ romin (* (rn) (- romax romin)))) 
     (setq risize (+ rsmin (* (rn) (- rsmax rsmin)))) 
     ; center of panel
     (setq cpt (list (+ (nth 0 pnt0) (/ xmax 2.0)) (+ (nth 1 pnt0) (/ ymax 2.0)) (nth 2 pnt0)))  
     ; center pt
     (setq pntc (list xpos ypos (nth 2 pnt0)))
     ; distance to center determines amount of offset
     (setq xdist (abs (- (nth 0 pntc) (nth 0 cpt)))) 
     (setq ydist (abs (- (nth 1 pntc) (nth 1 cpt))))
     (setq xprct (- 1.0 (/ xdist (/ (- xmax xside) 2.0))))
     (setq yprct (- 1.0 (/ ydist (/ (- ymax yside) 2.0))))
     (setq xoff (* (rn) (* xprct xyoff))) 
     (setq yoff (* (rn) (* yprct xyoff)))
     ; redefine center pt
     (if (and (>= xprct dfact) (>= yprct dfact))
       (setq pntc (list (+ (- xpos (/ (* xyoff xprct) 2)) xoff)
		        (+ (- ypos (/ (* xyoff yprct) 2)) yoff) (nth 2 pnt0)))
     )  
     ; make ring
     (command ".CIRCLE" pntc rorad)
     (command ".ZOOM" "e") 
     (command ".REGION" "last" "")
     (setq obj1 (ssadd (entlast))) 
     (command ".CIRCLE" pntc (- rorad risize))
     (command ".ZOOM" "e") 
     (command ".REGION" "last" "") 
     (setq obj2 (ssadd (entlast))) 
     (command ".SUBTRACT" obj1 "" obj2 "")
     ; inc x
     (setq xpos (+ xpos xside))
   )
   ; inc y
   (setq ypos (+ ypos yside))
 )
 ; union regions  
 (command ".UNION" "all" "")
 (setq obj1 (ssadd (entlast))) 
 ; inside border
 (setq pnt1 (list (+ (nth 0 pnt0) xmax) (+ (nth 1 pnt0) ymax)))
 (command ".RECTANGLE" pnt0 pnt1)
 (command ".ZOOM" "e") 
 (command ".REGION" "last" "")
 (setq obj2 (ssadd (entlast)))
 ; outside border
 (setq pnt2 (list (- (nth 0 pnt0) xmax) (- (nth 1 pnt0) ymax)))   
 (setq pnt3 (list (+ (nth 0 pnt1) xmax) (+ (nth 1 pnt1) ymax)))     
 (command ".RECTANGLE" pnt2 pnt3)
 (command ".ZOOM" "e") 
 (command ".REGION" "last" "")
 (setq obj3 (ssadd (entlast)))
 ; make border      
 (command ".SUBTRACT" obj3 "" obj2 "")
 (setq obj2 (ssadd (entlast)))
 ; subtract border from panel
 (command ".SUBTRACT" obj1 "" obj2 "")
 (command ".ZOOM" "e")  
 (princ)
)
;--------------------------------------------------------------------------
(defun prog03c ()
 (graphscr)
 ; ring relief 2D version
 (setq pnt0 (list 0 0 0))
 (setq xside  (getdist pnt0 "\nEnter X side panel:"))
 (setq yside  (getdist pnt0 "\nEnter Y side panel:"))
 (setq xtimes (getint "\nEnter number of X panels:"))
 (setq ytimes (getint "\nEnter number of Y panels:"))
 (setq romin  (getdist pnt0 "\nEnter ring radius outside min:"))
 (setq romax  (getdist pnt0 "\nEnter ring radius outside max:"))
 (setq rsmin  (getdist pnt0 "\nEnter ring size min:"))
 (setq rsmax  (getdist pnt0 "\nEnter ring size max:"))
 (setq xyoff  (getdist pnt0 "\nEnter XY offset:"))
 (setq dfact  (getreal "\nEnter distance factor:"))  
 (command ".ERASE" "all" "") 
 ;panel size
 (setq xmax (* xside xtimes))
 (setq ymax (* yside ytimes))
 ; start y location
 (setq ypos (+ (nth 1 pnt0) (/ yside 2)))
 (repeat ytimes 
   ; start x location
   (setq xpos (+ (nth 0 pnt0) (/ xside 2)))
   (repeat xtimes
     ; random ring size and offset
     (setq rorad (+ romin (* (rn) (- romax romin)))) 
     (setq risize (+ rsmin (* (rn) (- rsmax rsmin)))) 
     ; right edge of panel
     (setq cpt (list (+ (nth 0 pnt0) xmax) (+ (nth 1 pnt0) (/ ymax 2.0)) (nth 2 pnt0)))  
     ; center pt
     (setq pntc (list xpos ypos (nth 2 pnt0)))
     ; distance to center determines amount of offset
     (setq xdist (abs (- (nth 0 pntc) (nth 0 cpt)))) 
     (setq xprct (- 1.0 (/ xdist (- xmax xside))))
     (setq xoff (* (rn) (* xprct xyoff))) 
     (setq yoff (* (rn) (* xprct xyoff)))
     ; redefine center pt
     (if (>= xprct dfact)
       (setq pntc (list (+ (- xpos (/ (* xyoff xprct) 2)) xoff)
		        (+ (- ypos (/ (* xyoff xprct) 2)) yoff) (nth 2 pnt0)))
     )  
     ; make ring
     (command ".CIRCLE" pntc rorad)
     (command ".ZOOM" "e") 
     (command ".REGION" "last" "")
     (setq obj1 (ssadd (entlast))) 
     (command ".CIRCLE" pntc (- rorad risize))
     (command ".ZOOM" "e") 
     (command ".REGION" "last" "") 
     (setq obj2 (ssadd (entlast))) 
     (command ".SUBTRACT" obj1 "" obj2 "")
     ; inc x
     (setq xpos (+ xpos xside))
   )
   ; inc y
   (setq ypos (+ ypos yside))
 )
 ; union regions  
 (command ".UNION" "all" "")
 (setq obj1 (ssadd (entlast))) 
 ; inside border
 (setq pnt1 (list (+ (nth 0 pnt0) xmax) (+ (nth 1 pnt0) ymax)))
 (command ".RECTANGLE" pnt0 pnt1)
 (command ".ZOOM" "e") 
 (command ".REGION" "last" "")
 (setq obj2 (ssadd (entlast)))
 ; outside border
 (setq pnt2 (list (- (nth 0 pnt0) xmax) (- (nth 1 pnt0) ymax)))   
 (setq pnt3 (list (+ (nth 0 pnt1) xmax) (+ (nth 1 pnt1) ymax)))     
 (command ".RECTANGLE" pnt2 pnt3)
 (command ".ZOOM" "e") 
 (command ".REGION" "last" "")
 (setq obj3 (ssadd (entlast)))
 ; make border      
 (command ".SUBTRACT" obj3 "" obj2 "")
 (setq obj2 (ssadd (entlast)))
 ; subtract border from panel
 (command ".SUBTRACT" obj1 "" obj2 "")
 (command ".ZOOM" "e")  
 (princ)
)
;--------------------------------------------------------------------------
;--------------------------------------------------------------------------
(defun prog04 ()
 (graphscr)
 ; random sticks
 (setq pnt0 (list 0 0 0))
 (setq xside  (getdist pnt0 "\nEnter X side panel:"))
 (setq yside  (getdist pnt0 "\nEnter Y side panel:"))
 (setq xtimes (getint "\nEnter number of X panels:"))
 (setq ytimes (getint "\nEnter number of Y panels:"))
 (setq nsides (getint "\nEnter number of sides for polygon:")) 
 (setq romin  (getdist pnt0 "\nEnter ring radius outside min:"))
 (setq romax  (getdist pnt0 "\nEnter ring radius outside max:"))
 (setq rsmin  (getdist pnt0 "\nEnter ring size min:"))
 (setq rsmax  (getdist pnt0 "\nEnter ring size max:"))
 (setq xyoff  (getdist pnt0 "\nEnter XY offset:"))
 (setq rotang (getreal "\nEnter rotation angle:")) 
 (command ".ERASE" "all" "")
 ; start y location
 (setq ypos (+ (nth 1 pnt0) (/ yside 2)))
 (repeat ytimes 
   ; start x location
   (setq xpos (+ (nth 0 pnt0) (/ xside 2)))
   (repeat xtimes
     ; random polygon size, offset, and rotation
     (setq rorad (+ romin (* (rn) (- romax romin)))) 
     (setq risize (+ rsmin (* (rn) (- rsmax rsmin))))
     (setq xoff (* (rn) xyoff)) 
     (setq yoff (* (rn) xyoff))
     (setq rang (* (fix (* (rn) 360)) rotang))
     ; center pt 
     (setq pntc (list (+ (- xpos (/ xyoff 2)) xoff) (+ (- ypos (/ xyoff 2)) yoff) 0.0))
     ; make ring
     (command ".POLYGON" nsides pntc "C" rorad)
     (command ".ZOOM" "e") 
     (command ".REGION" "last" "")
     (setq obj1 (ssadd (entlast))) 
     (command ".POLYGON" nsides pntc "C" (- rorad risize))
     (command ".ZOOM" "e") 
     (command ".REGION" "last" "") 
     (setq obj2 (ssadd (entlast))) 
     (command ".SUBTRACT" obj1 "" obj2 "")
     (command ".ROTATE" "last" "" pntc rang) 
     ; inc x
     (setq xpos (+ xpos xside))
   )
   ; inc y
   (setq ypos (+ ypos yside))
 )
 ; union regions  
 (command ".UNION" "all" "")
 (setq obj1 (ssadd (entlast))) 
 ; inside border
 (setq xmax (* xside xtimes))
 (setq ymax (* yside ytimes))
 (setq pnt1 (list (+ (nth 0 pnt0) xmax) (+ (nth 1 pnt0) ymax)))
 (command ".RECTANGLE" pnt0 pnt1)
 (command ".ZOOM" "e") 
 (command ".REGION" "last" "")
 (setq obj2 (ssadd (entlast)))
 ; outside border
 (setq pnt2 (list (- (nth 0 pnt0) xmax) (- (nth 1 pnt0) ymax)))   
 (setq pnt3 (list (+ (nth 0 pnt1) xmax) (+ (nth 1 pnt1) ymax)))     
 (command ".RECTANGLE" pnt2 pnt3)
 (command ".ZOOM" "e") 
 (command ".REGION" "last" "")
 (setq obj3 (ssadd (entlast)))
 ; make border      
 (command ".SUBTRACT" obj3 "" obj2 "")
 (setq obj2 (ssadd (entlast)))
 ; subtract border from panel
 (command ".SUBTRACT" obj1 "" obj2 "")
 (setq obj1 (ssadd (entlast)))
 ; make frame at border
 ; inside border
 (setq pnt1 (list (+ (nth 0 pnt0) xmax) (+ (nth 1 pnt0) ymax)))
 (command ".RECTANGLE" pnt0 pnt1)
 (command ".ZOOM" "e") 
 (command ".REGION" "last" "")
 (setq obj2 (ssadd (entlast)))
 ; outside border
 (setq pnt2 (list (- (nth 0 pnt0) 1) (- (nth 1 pnt0) 1)))   
 (setq pnt3 (list (+ (nth 0 pnt1) 1) (+ (nth 1 pnt1) 1)))     
 (command ".RECTANGLE" pnt2 pnt3)
 (command ".ZOOM" "e") 
 (command ".REGION" "last" "")
 (setq obj3 (ssadd (entlast)))
 ; make frame      
 (command ".SUBTRACT" obj3 "" obj2 "")
 (setq obj2 (ssadd (entlast)))
 ; add to panel
 (command ".UNION" "all" "") 
 (command ".ZOOM" "e") 
 (princ)
)
;--------------------------------------------------------------------------
(defun dotrim ()
 ; inside border
 (setq pnt1 (list (+ (nth 0 pnt0) xmax) (+ (nth 1 pnt0) ymax)))
 (command ".RECTANGLE" pnt0 pnt1)
 (command ".ZOOM" "e") 
 (command ".REGION" "last" "")
 (setq obj2 (ssadd (entlast)))
 ; outside border
 (setq pnt2 (list (- (nth 0 pnt0) xmax) (- (nth 1 pnt0) ymax)))   
 (setq pnt3 (list (+ (nth 0 pnt1) xmax) (+ (nth 1 pnt1) ymax)))     
 (command ".RECTANGLE" pnt2 pnt3)
 (command ".ZOOM" "e") 
 (command ".REGION" "last" "")
 (setq obj3 (ssadd (entlast)))
 ; make border
 (command ".SUBTRACT" obj3 "" obj2 "")
 (setq obj2 (ssadd (entlast)))
 ; subtract border from panel
 (command ".SUBTRACT" obj1 "" obj2 "")
 (command ".ZOOM" "e")  
 (princ)
)
;--------------------------------------------------------------------------
;--------------------------------------------------------------------------
(defun prog05 ()
 (graphscr)
 ; ring relief 2D version
 (setq pnt0 (list 0 0 0))
 (setq xside  (getdist pnt0 "\nEnter X side panel:"))
 (setq yside  (getdist pnt0 "\nEnter Y side panel:"))
 (setq xtimes (getint "\nEnter number of X panels:"))
 (setq ytimes (getint "\nEnter number of Y panels:"))
 (setq romin  (getdist pnt0 "\nEnter ring radius outside min:"))
 (setq romax  (getdist pnt0 "\nEnter ring radius outside max:"))
 (setq rsmin  (getdist pnt0 "\nEnter ring size min:"))
 (setq rsmax  (getdist pnt0 "\nEnter ring size max:"))
 (setq xyoff  (getdist pnt0 "\nEnter XY offset:"))
 (setq nlayers (getint "\nEnter number of layers, 1 to 4:"))
 (command ".ERASE" "all" "")
 ; selection lists
 ;(setq layer01 (ssadd) layer02 (ssadd) layer03 (ssadd) layer04 (ssadd))
 (setq layer01 (ssadd))
 (setq layer02 (ssadd))
 (setq layer03 (ssadd))
 (setq layer04 (ssadd))
 ; panel dims
 (setq xmax (* xside xtimes))
 (setq ymax (* yside ytimes))
 ; start y location
 (setq ypos (+ (nth 1 pnt0) (/ yside 2)))
 (repeat ytimes 
   ; start x location
   (setq xpos (+ (nth 0 pnt0) (/ xside 2)))
   (repeat xtimes
     ; random ring size and offset
     (setq rorad (+ romin (* (rn) (- romax romin)))) 
     (setq risize (+ rsmin (* (rn) (- rsmax rsmin)))) 
     (setq xoff (* (rn) xyoff)) 
     (setq yoff (* (rn) xyoff))
     (setq nlayer (+ (fix (* (rn) (- nlayers 0.1))) 1))
     ; center pt
     (setq pntc (list (+ (- xpos (/ xyoff 2)) xoff) (+ (- ypos (/ xyoff 2)) yoff) 0.0))
     ; make ring
     (command ".CIRCLE" pntc rorad)
     (command ".ZOOM" "e") 
     (command ".REGION" "last" "")
     (setq obj1 (ssadd (entlast))) 
     (command ".CIRCLE" pntc (- rorad risize))
     (command ".ZOOM" "e") 
     (command ".REGION" "last" "") 
     (setq obj2 (ssadd (entlast))) 
     (command ".SUBTRACT" obj1 "" obj2 "")
     (setq layer01 (ssadd (entlast) layer01))
     (if (>= nlayer 2) (progn
       (command ".COPY" "last" "" pntc pntc )
       (setq layer02 (ssadd (entlast) layer02))
     ))    
     (if (>= nlayer 3) (progn
       (command ".COPY" "last" "" pntc pntc )
       (setq layer03 (ssadd (entlast) layer03))
    ))    
     (if (>= nlayer 4) (progn
       (command ".COPY" "last" "" pntc pntc )
       (setq layer04 (ssadd (entlast) layer04))
     ))    
     ; inc x
     (setq xpos (+ xpos xside))
   )
   ; inc y
   (setq ypos (+ ypos yside))
 )
 ; union and trim each layer
 (command ".ZOOM" "e") 
 (setq obj1 layer01)
 (dotrim)
 (setq layers (ssadd (entlast))) 
 (if (> nlayers 1) (progn  
   (setq obj1 layer02)
   (dotrim)
   (setq layers (ssadd (entlast) layers)) 
 ))
 (if (> nlayers 2) (progn  
   (setq obj1 layer03)
   (dotrim)
 ))
 (if (> nlayers 3) (progn  
   (setq obj1 layer04)
   (dotrim)
 ))
 ; separate layers
 (setq layers (ssget "a")) 
 (setq cnt 0)
 (repeat (sslength layers)
   (setq obj (ssname layers cnt)) 
   (setq pnt1 (list (- (nth 0 pnt0) (* (+ xmax xside) (+ cnt 1))) (nth 1 pnt0) (nth 2 pnt0)))  
   (command ".MOVE" obj "" pnt0 pnt1)
   (command ".ZOOM" "e")
   (setq cnt (+ cnt 1))
 )  
 (princ)
)
;--------------------------------------------------------------------------
(defun prog06 ()
 (graphscr)
 ; ring relief 2D version
 (setq pnt0 (list 0 0 0))
 (setq xside  (getdist pnt0 "\nEnter X side panel:"))
 (setq yside  (getdist pnt0 "\nEnter Y side panel:"))
 (setq xtimes (getint "\nEnter number of X panels:"))
 (setq ytimes (getint "\nEnter number of Y panels:"))
 (setq romin  (getdist pnt0 "\nEnter ring radius outside min:"))
 (setq romax  (getdist pnt0 "\nEnter ring radius outside max:"))
 (setq rsmin  (getdist pnt0 "\nEnter ring size min:"))
 (setq rsmax  (getdist pnt0 "\nEnter ring size max:"))
 (setq xyoff  (getdist pnt0 "\nEnter XY offset:"))
 (command ".ERASE" "all" "") 
 ;panel size
 (setq xmax (* xside xtimes))
 (setq ymax (* yside ytimes))
 ; start y location
 (setq ypos (+ (nth 1 pnt0) (/ yside 2)))
 (repeat ytimes 
   ; start x location
   (setq xpos (+ (nth 0 pnt0) (/ xside 2)))
   (repeat xtimes
     ; random ring size and offset
     (setq rorad (+ romin (* (rn) (- romax romin)))) 
     (setq risize (+ rsmin (* (rn) (- rsmax rsmin)))) 
     (setq xoff (* (rn) xyoff)) 
     (setq yoff (* (rn) xyoff))
     ; center pt
     (setq pntc (list (+ (- xpos (/ xyoff 2)) xoff) (+ (- ypos (/ xyoff 2)) yoff) 0.0))
     ; select type of ring
     (setq rtype (+ (fix (* (rn) 4.99)) 1))
     (if (= rtype 1) (progn
       (command ".CIRCLE" pntc rorad)
       (command ".ZOOM" "e") 
       (command ".REGION" "last" "")
       (setq obj1 (ssadd (entlast))) 
       (command ".CIRCLE" pntc (- rorad risize))
       (command ".ZOOM" "e") 
       (command ".REGION" "last" "") 
       (setq obj2 (ssadd (entlast))) 
       (command ".SUBTRACT" obj1 "" obj2 "")
     ))  
     (if (= rtype 2) (progn
       (command ".POLYGON" "3" pntc "C" rorad)
       (command ".ZOOM" "e") 
       (command ".REGION" "last" "")
       (setq obj1 (ssadd (entlast))) 
       (command ".POLYGON" "3" pntc "C" (- rorad risize))
       (command ".ZOOM" "e") 
       (command ".REGION" "last" "") 
       (setq obj2 (ssadd (entlast))) 
       (command ".SUBTRACT" obj1 "" obj2 "")
     ))  
     (if (= rtype 3) (progn
       (command ".POLYGON" "4" pntc "C" rorad)
       (command ".ZOOM" "e") 
       (command ".REGION" "last" "")
       (setq obj1 (ssadd (entlast))) 
       (command ".POLYGON" "4" pntc "C" (- rorad risize))
       (command ".ZOOM" "e") 
       (command ".REGION" "last" "") 
       (setq obj2 (ssadd (entlast))) 
       (command ".SUBTRACT" obj1 "" obj2 "")
     ))  
     (if (= rtype 4) (progn
       (command ".POLYGON" "5" pntc "C" rorad)
       (command ".ZOOM" "e") 
       (command ".REGION" "last" "")
       (setq obj1 (ssadd (entlast))) 
       (command ".POLYGON" "5" pntc "C" (- rorad risize))
       (command ".ZOOM" "e") 
       (command ".REGION" "last" "") 
       (setq obj2 (ssadd (entlast))) 
       (command ".SUBTRACT" obj1 "" obj2 "")
     ))  
     (if (= rtype 5) (progn
       (command ".POLYGON" "6" pntc "C" rorad)
       (command ".ZOOM" "e") 
       (command ".REGION" "last" "")
       (setq obj1 (ssadd (entlast))) 
       (command ".POLYGON" "6" pntc "C" (- rorad risize))
       (command ".ZOOM" "e") 
       (command ".REGION" "last" "") 
       (setq obj2 (ssadd (entlast))) 
       (command ".SUBTRACT" obj1 "" obj2 "")
     ))  
     ; inc x
     (setq xpos (+ xpos xside))
   )
   ; inc y
   (setq ypos (+ ypos yside))
 )
 ; union regions  
 (command ".UNION" "all" "")
 (setq obj1 (ssadd (entlast))) 
 ; inside border
 (setq pnt1 (list (+ (nth 0 pnt0) xmax) (+ (nth 1 pnt0) ymax)))
 (command ".RECTANGLE" pnt0 pnt1)
 (command ".ZOOM" "e") 
 (command ".REGION" "last" "")
 (setq obj2 (ssadd (entlast)))
 ; outside border
 (setq pnt2 (list (- (nth 0 pnt0) xmax) (- (nth 1 pnt0) ymax)))   
 (setq pnt3 (list (+ (nth 0 pnt1) xmax) (+ (nth 1 pnt1) ymax)))     
 (command ".RECTANGLE" pnt2 pnt3)
 (command ".ZOOM" "e") 
 (command ".REGION" "last" "")
 (setq obj3 (ssadd (entlast)))
 ; make border      
 (command ".SUBTRACT" obj3 "" obj2 "")
 (setq obj2 (ssadd (entlast)))
 ; subtract border from panel
 (command ".SUBTRACT" obj1 "" obj2 "")
 (command ".ZOOM" "e")  
 (princ)
)
;--------------------------------------------------------------------------
;--------------------------------------------------------------------------
(defun prog06a ()
 (graphscr)
 ; ring relief 2D version
 (setq pnt0 (list 0 0 0))
 (setq xside  (getdist pnt0 "\nEnter X side panel:"))
 (setq yside  (getdist pnt0 "\nEnter Y side panel:"))
 (setq xtimes (getint "\nEnter number of X panels:"))
 (setq ytimes (getint "\nEnter number of Y panels:"))
 (setq romin  (getdist pnt0 "\nEnter ring radius outside min:"))
 (setq romax  (getdist pnt0 "\nEnter ring radius outside max:"))
 (setq rsmin  (getdist pnt0 "\nEnter ring size min:"))
 (setq rsmax  (getdist pnt0 "\nEnter ring size max:"))
 (setq xyoff  (getdist pnt0 "\nEnter XY offset:"))
 (setq plist  (read (getstring "\nEnter random list of selections:"))) 
 (command ".ERASE" "all" "") 
 ;panel size
 (setq xmax (* xside xtimes))
 (setq ymax (* yside ytimes))
 ; start y location
 (setq ypos (+ (nth 1 pnt0) (/ yside 2)))
 (repeat ytimes 
   ; start x location
   (setq xpos (+ (nth 0 pnt0) (/ xside 2)))
   (repeat xtimes
     ; random ring size and offset
     (setq rorad (+ romin (* (rn) (- romax romin)))) 
     (setq risize (+ rsmin (* (rn) (- rsmax rsmin)))) 
     (setq xoff (* (rn) xyoff)) 
     (setq yoff (* (rn) xyoff))
     ; center pt
     (setq pntc (list (+ (- xpos (/ xyoff 2)) xoff) (+ (- ypos (/ xyoff 2)) yoff) 0.0))
     ; select type of ring
     (setq nlist (fix (* (rn) (- (length plist) 0.1))))
     (setq rtype (nth nlist plist))
     (if (= rtype 1) (progn
       (command ".CIRCLE" pntc rorad)
       (command ".ZOOM" "e") 
       (command ".REGION" "last" "")
       (setq obj1 (ssadd (entlast))) 
       (command ".CIRCLE" pntc (- rorad risize))
       (command ".ZOOM" "e") 
       (command ".REGION" "last" "") 
       (setq obj2 (ssadd (entlast))) 
       (command ".SUBTRACT" obj1 "" obj2 "")
     ))  
     (if (= rtype 2) (progn
       (command ".POLYGON" "3" pntc "C" rorad)
       (command ".ZOOM" "e") 
       (command ".REGION" "last" "")
       (setq obj1 (ssadd (entlast))) 
       (command ".POLYGON" "3" pntc "C" (- rorad risize))
       (command ".ZOOM" "e") 
       (command ".REGION" "last" "") 
       (setq obj2 (ssadd (entlast))) 
       (command ".SUBTRACT" obj1 "" obj2 "")
     ))  
     (if (= rtype 3) (progn
       (command ".POLYGON" "4" pntc "C" rorad)
       (command ".ZOOM" "e") 
       (command ".REGION" "last" "")
       (setq obj1 (ssadd (entlast))) 
       (command ".POLYGON" "4" pntc "C" (- rorad risize))
       (command ".ZOOM" "e") 
       (command ".REGION" "last" "") 
       (setq obj2 (ssadd (entlast))) 
       (command ".SUBTRACT" obj1 "" obj2 "")
     ))  
     (if (= rtype 4) (progn
       (command ".POLYGON" "5" pntc "C" rorad)
       (command ".ZOOM" "e") 
       (command ".REGION" "last" "")
       (setq obj1 (ssadd (entlast))) 
       (command ".POLYGON" "5" pntc "C" (- rorad risize))
       (command ".ZOOM" "e") 
       (command ".REGION" "last" "") 
       (setq obj2 (ssadd (entlast))) 
       (command ".SUBTRACT" obj1 "" obj2 "")
     ))  
     (if (= rtype 5) (progn
       (command ".POLYGON" "6" pntc "C" rorad)
       (command ".ZOOM" "e") 
       (command ".REGION" "last" "")
       (setq obj1 (ssadd (entlast))) 
       (command ".POLYGON" "6" pntc "C" (- rorad risize))
       (command ".ZOOM" "e") 
       (command ".REGION" "last" "") 
       (setq obj2 (ssadd (entlast))) 
       (command ".SUBTRACT" obj1 "" obj2 "")
     ))  
     ; inc x
     (setq xpos (+ xpos xside))
   )
   ; inc y
   (setq ypos (+ ypos yside))
 )
 ; union regions  
 (command ".UNION" "all" "")
 (setq obj1 (ssadd (entlast))) 
 ; inside border
 (setq pnt1 (list (+ (nth 0 pnt0) xmax) (+ (nth 1 pnt0) ymax)))
 (command ".RECTANGLE" pnt0 pnt1)
 (command ".ZOOM" "e") 
 (command ".REGION" "last" "")
 (setq obj2 (ssadd (entlast)))
 ; outside border
 (setq pnt2 (list (- (nth 0 pnt0) xmax) (- (nth 1 pnt0) ymax)))   
 (setq pnt3 (list (+ (nth 0 pnt1) xmax) (+ (nth 1 pnt1) ymax)))     
 (command ".RECTANGLE" pnt2 pnt3)
 (command ".ZOOM" "e") 
 (command ".REGION" "last" "")
 (setq obj3 (ssadd (entlast)))
 ; make border      
 (command ".SUBTRACT" obj3 "" obj2 "")
 (setq obj2 (ssadd (entlast)))
 ; subtract border from panel
 (command ".SUBTRACT" obj1 "" obj2 "")
 (command ".ZOOM" "e")  
 (princ)
)
;--------------------------------------------------------------------------
;--------------------------------------------------------------------------
(defun prog06b ()
 (graphscr)
 ; ring relief 2D version
 (setq pnt0 (list 0 0 0))
 (setq xside  (getdist pnt0 "\nEnter X side panel:"))
 (setq yside  (getdist pnt0 "\nEnter Y side panel:"))
 (setq xtimes (getint "\nEnter number of X panels:"))
 (setq ytimes (getint "\nEnter number of Y panels:"))
 (setq blist  (read (getstring "\nEnter random list of selections:"))) 
 (command ".ERASE" "all" "") 
 ;panel size
 (setq xmax (* xside xtimes))
 (setq ymax (* yside ytimes))
 ; start y location
 (setq ypos (+ (nth 1 pnt0) (/ yside 2)))
 (repeat ytimes 
   ; start x location
   (setq xpos (+ (nth 0 pnt0) (/ xside 2)))
   (repeat xtimes
     ; random rotation
     (setq rang (* (fix (* (rn) 3.99)) 90))
     ; center pt
     (setq pntc (list xpos ypos (nth 2 pnt0)))
     ; select type of ring
     (setq nlist (fix (* (rn) (- (length blist) 0.1))))
     (setq nblock (nth nlist blist))
     ; get block
     (command ".INSERT" nblock "s" xside pntc rang)    
     (command ".ZOOM" "e") 
     (command ".EXPLODE" "last")  
     ; inc x
     (setq xpos (+ xpos xside))
   )
   ; inc y
   (setq ypos (+ ypos yside))
 )
 ; union regions  
 (command ".UNION" "all" "")
 (setq obj1 (ssadd (entlast))) 
 ; inside border
 (setq pnt1 (list (+ (nth 0 pnt0) xmax) (+ (nth 1 pnt0) ymax)))
 (command ".RECTANGLE" pnt0 pnt1)
 (command ".ZOOM" "e") 
 (command ".REGION" "last" "")
 (setq obj2 (ssadd (entlast)))
 ; outside border
 (setq pnt2 (list (- (nth 0 pnt0) xmax) (- (nth 1 pnt0) ymax)))   
 (setq pnt3 (list (+ (nth 0 pnt1) xmax) (+ (nth 1 pnt1) ymax)))     
 (command ".RECTANGLE" pnt2 pnt3)
 (command ".ZOOM" "e") 
 (command ".REGION" "last" "")
 (setq obj3 (ssadd (entlast)))
 ; make border      
 (command ".SUBTRACT" obj3 "" obj2 "")
 (setq obj2 (ssadd (entlast)))
 ; subtract border from panel
 (command ".SUBTRACT" obj1 "" obj2 "")
 (command ".ZOOM" "e")  
 (princ)
)
;--------------------------------------------------------------------------
;---------------------------------------------------------------------------
(defun prog07 ()
 (graphscr)
 ; packed circles
 ; random circle size
 (setq pnt0 (list 0 0 0))
 (setq xside  (getdist pnt0 "\nEnter X side panel:"))
 (setq yside  (getdist pnt0 "\nEnter Y side panel:"))
 (setq xtimes (getint "\nEnter number of X panels:"))
 (setq ytimes (getint "\nEnter number of Y panels:"))
 (setq rmin   (getdist pnt0 "\nEnter min radius:"))
 (setq rmax   (getdist pnt0 "\nEnter max radius:"))
 ; count number of failures to stop at
 (setq nfails 2000)
 ; count of circles drawn
 (setq ncircles 0)
 ; list of placed circles
 (setq clist (list ))
 ; panel
 (setq xmax (* xside xtimes))
 (setq ymax (* yside ytimes))
 (command ".RECTANGLE" pnt0 (list (+ (nth 0 pnt0) xmax) (+ (nth 1 pnt0) ymax)))
 (command ".ZOOM" "e")
 ; packed circles
 (setq ido 1)
 (while (= ido 1) 
   ; random circle size and location
   (setq rad (+ rmin (* (rn) (- rmax rmin)))) 
   (setq xpos (* (rn) xmax)) 
   (setq ypos (* (rn) ymax))
   ; center pt
   (setq pntc (list (+ (nth 0 pnt0) xpos) (+ (nth 1 pnt0) ypos) (nth 2 pnt0)))
   ; check prevision locations
   (setq idraw 1)
   (if (> ncircles 0) (progn
     (setq ic 0)		  
     (repeat ncircles
       (setq pntp (nth 0 (nth ic clist)))
       (setq radp (nth 1 (nth ic clist)))
       (setq cdist (distance pntp pntc))
       ; spacing of 10 percent
       (if (< (- cdist (* rmin 1.10)) (+ rad radp)) (progn
          (setq idraw 0)
       ))				    
     (setq ic (+ ic 1))        
     )		  
   ))		  
   ; failed
   (if (= idraw 0) (progn
      (setq ifail (+ ifail 1))
      (princ "\nFailed=") (princ ifail)
   ))
   ; draw circle
   (if (= idraw 1) (progn
     (command ".CIRCLE" pntc rad)
     (command ".REGION" "last" "")
     ; add to list: location and radius
     (setq clist (append (list (list pntc rad)) clist))
     (setq ncircles (+ ncircles 1))
     (setq ifail 0)		  
   ))
 ; check if to stop
 (if (> ifail nfails) (setq ido 0))  
 )
 (command ".ZOOM" "e")
 ; union regions  
 (command ".UNION" "all" "")
 (setq obj1 (ssadd (entlast))) 
 ; inside border
 (setq pnt1 (list (+ (nth 0 pnt0) xmax) (+ (nth 1 pnt0) ymax)))
 (command ".RECTANGLE" pnt0 pnt1)
 (command ".ZOOM" "e") 
 (command ".REGION" "last" "")
 (setq obj2 (ssadd (entlast)))
 ; outside border
 (setq pnt2 (list (- (nth 0 pnt0) xmax) (- (nth 1 pnt0) ymax)))   
 (setq pnt3 (list (+ (nth 0 pnt1) xmax) (+ (nth 1 pnt1) ymax)))     
 (command ".RECTANGLE" pnt2 pnt3)
 (command ".ZOOM" "e") 
 (command ".REGION" "last" "")
 (setq obj3 (ssadd (entlast)))
 ; make border      
 (command ".SUBTRACT" obj3 "" obj2 "")
 (setq obj2 (ssadd (entlast)))
 ; subtract border from panel
 (command ".SUBTRACT" obj1 "" obj2 "")
 (command ".ZOOM" "e")  
 (princ)
)
;--------------------------------------------------------------------------
;--------------------------------------------------------------------------