Megatest

  (hash-table-set! (vg:lib-comps lib) compname comp))

;; instanciate component in drawing
;;
(define (vg:instantiate drawing libname compname instname xoff yoff #!key (theta 0)(scalex 1)(scaley 1)(mirrx #f)(mirry #f))
  (let ((inst (make-vg:inst libname: libname compname: compname xoff: xoff yoff: yoff theta: theta scalex: scalex scaley: scaley mirrx: mirrx mirry: mirry)) )
    (hash-table-set! (vg:drawing-insts drawing) instname inst)))

(define (vg:instance-move drawing instname newx newy)
  (let ((inst (hash-table-ref (vg:drawing-insts drawing) instname)))
    (vg:inst-xoff-set! inst newx)
    (vg:inst-yoff-set! inst newy)))

;; get component from drawing (look in apropriate lib) given libname and compname
(define (vg:get-component drawing libname compname)
  (let* ((lib  (hash-table-ref (vg:drawing-libs drawing) libname))
	 (inst (hash-table-ref (vg:lib-comps lib) compname)))
    inst))

;; given rectangles r1 and r2, return the box that bounds both
;;
(define (vg:get-extents-for-two-rects r1 r2)
  (if (not r1)
      r2
      (if (not r2)
	  r1 ;; #f ;; no extents from #f #f
	  (list (min (car r1)(car r2))           ;; llx
		(min (cadr r1)(cadr r2))         ;; lly
		(max (caddr r1)(caddr r2))       ;; ulx
		(max (cadddr r1)(cadddr r2)))))) ;; uly

(define (vg:components-get-extents drawing . comps)
  (let ((extents #f))