ADDED   vg-test.scm
Index: vg-test.scm
==================================================================
--- /dev/null
+++ vg-test.scm
@@ -0,0 +1,44 @@
+(use canvas-draw iup)
+(import canvas-draw-iup)
+
+(load "vg.scm")
+
+(define d1 (vg:drawing-new))
+(define l1 (vg:lib-new))
+(define c1 (vg:comp-new))
+(let ((r1 (vg:make-rect 10 10 100 80))
+      (r2 (vg:make-rect 100 80 190 150)))
+  (vg:add-objs-to-comp c1 r1 r2))
+
+;; add the c1 component to lib l1 with name firstcomp
+(vg:add-comp-to-lib l1 "firstcomp" c1)
+
+;; add the l1 lib to drawing with name firstlib
+(vg:add-lib d1 "firstlib" l1)
+
+;; instantiate firstlib/firstcomp as inst1 in drawing d1 at 0,0
+(vg:instantiate d1 "firstlib" "firstcomp" "inst1" 0 0 0)
+(vg:instantiate d1 "firstlib" "firstcomp" "inst2" 200 200 0)
+
+(define cnv #f)
+(define the-cnv (canvas 
+		 #:size "500x400"
+		 #:expand "YES"
+		 #:scrollbar "YES"
+		 #:posx "0.5"
+		 #:posy "0.5"
+		 #:action (make-canvas-action
+			   (lambda (c xadj yadj)
+			     (set! cnv c)))))
+
+(show
+ (dialog
+  (vbox
+   the-cnv)))
+
+(vg:drawing-cnv-set! d1 cnv)
+(vg:draw d1)
+
+;; (canvas-rectangle! cnv  10 100 10 80)
+
+(main-loop)

ADDED   vg.scm
Index: vg.scm
==================================================================
--- /dev/null
+++ vg.scm
@@ -0,0 +1,130 @@
+;;
+;; Copyright 2016  Matthew Welland.
+;; 
+;;  This program is made available under the GNU GPL version 2.0 or
+;;  greater. See the accompanying file COPYING for details.
+;; 
+;;  This program is distributed WITHOUT ANY WARRANTY; without even the
+;;  implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+;;  PURPOSE.
+
+;;  strftime('%m/%d/%Y %H:%M:%S','now','localtime')
+
+(use defstruct)
+
+(declare (unit vg))
+
+;; structs
+;;
+(defstruct vg:lib     comps)
+(defstruct vg:comp    objs name file)
+(defstruct vg:obj     type pts fill-color text line-color call-back font)
+(defstruct vg:inst    libname compname theta xoff yoff scale mirrx mirry call-back)
+(defstruct vg:drawing libs insts cnv) ;; libs: hash of name->lib, insts: hash of instname->inst
+
+;; inits
+;;
+(define (vg:comp-new)
+  (make-vg:comp objs: '() name: #f file: #f))
+
+(define (vg:lib-new)
+  (make-vg:lib comps: (make-hash-table)))
+
+(define (vg:drawing-new)
+  (make-vg:drawing libs: (make-hash-table) insts: (make-hash-table)))
+
+;; make a rectangle obj
+;;
+(define (vg:make-rect x1 y1 x2 y2 #!key (line-color #f)(fill-color #f))
+  (make-vg:obj type: 'r pts: (list x1 y1 x2 y2) text: #f line-color: line-color fill-color: fill-color))
+
+;; add obj to comp
+;;
+(define (vg:add-objs-to-comp comp . objs)
+  (vg:comp-objs-set! comp (append (vg:comp-objs comp) objs)))
+
+;; add comp to lib
+;;
+(define (vg:add-comp-to-lib lib compname comp)
+  (hash-table-set! (vg:lib-comps lib) compname comp))
+
+;; instanciate component in drawing
+;;
+(define (vg:instantiate drawing libname compname instname xoff yoff t #!key (scale 1)(mirrx #f)(mirry #f))
+  (let ((inst (make-vg:inst libname: libname compname: compname xoff: xoff yoff: yoff theta: t scale: scale mirrx: mirrx mirry: mirry)) )
+    (hash-table-set! (vg:drawing-insts drawing) instname inst)))
+
+;; 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))
+
+;; register lib with drawing
+;;
+(define (vg:add-lib drawing libname lib)
+  (hash-table-set! (vg:drawing-libs drawing) libname lib))
+
+;;======================================================================
+;; map objects given offset, scale and mirror
+;;======================================================================
+
+(define (vg:map-obj xoff yoff theta scale mirrx mirry obj)
+  (case (vg:obj-type obj)
+    ((r)(vg:map-rect xoff yoff theta scale mirrx mirry obj))
+    (else #f)))
+
+(define (vg:map-rect xoff yoff theta scale mirrx mirry obj)
+  (let ((res (make-vg:obj type:       'r
+			  fill-color: (vg:obj-fill-color obj)
+			  text:       (vg:obj-text       obj)
+			  line-color: (vg:obj-line-color obj)
+			  font:       (vg:obj-font       obj)))
+	(pts (vg:obj-pts obj)))
+    (vg:obj-pts-set! res 
+		     (list (+ xoff (car pts))
+			   (+ yoff (cadr pts))
+			   (+ xoff (caddr pts))
+			   (+ yoff (cadddr pts))))
+    res))
+
+;;======================================================================
+;; Unravel and draw the objects
+;;======================================================================
+
+(define (vg:draw-obj cnv obj)
+  (print "obj type: " (vg:obj-type obj))
+  (case (vg:obj-type obj)
+    ((r)(vg:draw-rect cnv obj))))
+
+(define (vg:draw-rect cnv obj)
+  (let* ((pts (vg:obj-pts obj))
+	 (llx (car pts))
+	 (lly (cadr pts))
+	 (urx (caddr pts))
+	 (ury (cadddr pts)))
+    (print "(canvas-rectangle! " cnv " " llx " " urx " " lly " " ury ")")
+    (canvas-rectangle! cnv llx urx lly ury)
+    ))
+
+(define (vg:draw drawing)
+  (let ((insts (vg:drawing-insts drawing))
+	(cnv   (vg:drawing-cnv   drawing)))
+    (for-each 
+     (lambda (inst)
+       (let* ((xoff     (vg:inst-xoff inst))
+	      (yoff     (vg:inst-yoff inst))
+	      (theta    (vg:inst-theta inst))
+	      (scale    (vg:inst-scale inst))
+	      (mirrx    (vg:inst-mirrx inst))
+	      (mirry    (vg:inst-mirry inst))
+	      (libname  (vg:inst-libname inst))
+	      (compname (vg:inst-compname inst))
+	      (comp     (vg:get-component drawing libname compname)))
+	 (print "comp: " comp)
+	 (for-each
+	  (lambda (obj)
+	    (print "obj: " obj)
+	    (vg:draw-obj cnv (vg:map-obj xoff yoff theta scale mirrx mirry obj)))
+	  (vg:comp-objs comp))))
+    (hash-table-values insts))))