Here's one way to do graphics in Arc using DrScheme and MrEd.
I loaded "as.scm" into DrScheme.
I added simple make-canvas and draw-point commands to the as.scm code to use the MrEd Graphical Toolbox, and exported these commands to Arc.
I wrote a simple Arc function to draw the Sierpinski triangle using these graphics functions.
Specifically, I added the following code to as.scm.
(define (make-canvas w h)
(define frame (instantiate frame% ("Gasket by Ken Shirriff") (width w) (height h)))
(define canvas (instantiate canvas% (frame)))
(define dc (send canvas get-dc))
(send frame show #t)
dc ;; Return drawing context
)
; Export simple drawing functions to Arc
(xdef 'make-canvas (lambda (w h) (make-canvas w h)))
(xdef 'draw-point (lambda (dc x y) (send dc draw-point x y)))
Then I clicked "Run" in DrScheme and entered the following into Arc:
Arc>(def gasket (x y w)
(if (< w 1)
(draw-point dc x y)
(do (gasket x y (/ w 2))
(gasket (+ x (/ w 2)) y (/ w 2))
(gasket x (+ y (/ w 2)) (/ w 2)))))
Arc>(= dc (make-canvas 300 300))
Arc>(gasket 0 0 256)
