;;CADALYST 12/03 AutoLISP Solutions  SPLINE-TO-PLINE.LSP
;;(c) 2003 Tony Hotchkiss

(defun spline-to-pline (/ i)
  (vl-load-com)
  (setq	*thisdrawing* (vla-get-activedocument
			(vlax-get-acad-object)
		      ) ;_ end of vla-get-activedocument
	*modelspace*  (vla-get-ModelSpace *thisdrawing*)
  ) ;_ end of setq
  (setq spline-list (get-spline))
  (setq i (- 1))
  (if spline-list
    (progn
      (setq msg "\nNumber of segments <100>: ")
      (initget 6)
      (setq num (getint msg))
      (if (or (= num 100) (= num nil))
	(setq num 100)
      ) ;_ end of if
      (repeat (length spline-list)
	(setq splobj (nth (setq i (1+ i)) spline-list))
	(convert-spline splobj num)
      ) ;_ end of repeat
    ) ;_ end of progn
  ) ;_ end of if
) ;_ end of spline-to-pline

(defun get-spline (/ spl-list obj spline no-ent i)
  (setq	spl-list nil
	obj	 nil
	spline	 "AcDbSpline"
	selsets	 (vla-get-selectionsets *thisdrawing*)
	ss1	 (vlax-make-variant "ss1")
  ) ;_ end of setq
  (if (= (vla-get-count selsets) 0)
    (setq ssobj (vla-add selsets ss1))
  ) ;_ end of if
  (vla-clear ssobj)
  (setq no-ent 1)
  (while no-ent
    (prompt "\nSelect splines: ")
    (vla-Selectonscreen ssobj)
    (if	(> (vla-get-count ssobj) 0)
      (progn
	(setq no-ent nil)
	(setq i (- 1))
	(repeat	(vla-get-count ssobj)
	  (setq
	    obj	(vla-item ssobj
			  (vlax-make-variant (setq i (1+ i)))
		) ;_ end of vla-item
	  ) ;_ end of setq
	  (cond
	    ((= (vlax-get-property obj "ObjectName") spline)
	     (setq spl-list
		    (append spl-list (list obj))
	     ) ;_ end of setq
	    )
	  ) ;_ end-of cond
	) ;_ end of repeat
      ) ;_ end of progn
      (prompt "\nNo entities selected, try again.")
    ) ;_ end of if
    (if	(and (= nil no-ent) (= nil spl-list))
      (progn
	(setq no-ent 1)
	(prompt "\nNo splines selected.")
	(quit)
      ) ;_ end of progn
    ) ;_ end of if
  ) ;_ end of while  
  (vla-delete (vla-item selsets 0))
  spl-list
) ;_ end of get-spline

(defun convert-spline (splobj n / i)
  (setq	point-list   nil
	2Dpoint-list nil
	z-list	     nil
	spl-lyr	     (vlax-get-property splobj 'Layer)
	startSpline  (vlax-curve-getStartParam splobj)
	endSpline    (vlax-curve-getEndParam splobj)
	i	     (- 1)
  ) ;_ end of setq
  (repeat (+ n 1)
    (setq i (1+ i))
    (setq p (vlax-curve-getPointAtParam
	      splobj
	      (* i
		 (/ (- endspline startspline) n)
	      ) ;_ end of *
	    ) ;_ end of vlax-curve-getPointAtParam
    ) ;_ end of setq
    (setq 2Dp	       (list (car p) (cadr p))
	  2Dpoint-list (append 2Dpoint-list 2Dp)
	  point-list   (append point-list p)
	  z	       (caddr p)
	  z-list       (append z-list (list z))
    ) ;_ end of setq
  ) ;_ end of repeat
  (setq summ (apply '+ z-list))
  (setq	arraySpace
	 (vlax-make-safearray
	   vlax-vbdouble ; element type
	   (cons 0
		 (- (length point-list) 1)
	   ) ; array dimension
	 ) ;_ end of vlax-make-safearray
  ) ;_ end of setq
  (setq vert-array (vlax-safearray-fill arraySpace point-list))
  (vlax-make-variant vert-array)
  (if (and (= :vlax-true (vlax-get-property splobj 'IsPLanar))
	   (= summ 0.0)
      ) ;_ end of and
    (setq plobj	(add-polyline
		  2Dpoint-list
		  vla-AddLightweightPolyline
		) ;_ end of add-polyline
    ) ;_ end of setq
    (setq plobj	(add-polyline
		  point-list
		  vla-Add3DPoly
		) ;_ end of add-polyline
    ) ;_ end of setq
  ) ;_ end of if
  (vlax-put-property plobj 'Layer spl-lyr)
  (vla-delete splobj)
  (vlax-release-object splobj)
) ;_ end of convert-spline

(defun add-polyline (pt-list poly-func)
  (setq	arraySpace
	 (vlax-make-safearray
	   vlax-vbdouble
	   (cons 0
		 (- (length pt-list) 1)
	   ) ; array dimension
	 ) ;_ end of vlax-make-safearray
  ) ;_ end of setq
  (setq	vertex-array
	 (vlax-safearray-fill arraySpace pt-list)
  ) ;_ end of setq
  (vlax-make-variant vertex-array)
  (setq	plobj (poly-func
		*modelspace*
		vertex-array
	      ) ;_ end of poly-func
  ) ;_ end of setq
) ;_ end of add-polyline

(defun c:s2p ()
  (spline-to-pline)
  (princ)
) ;_ end of c:s2p

(prompt
  "SPLINE-TO-PLINE by Tony Hotchkiss. Enter S2P to start"
) ;_ end of prompt