(define draw-disc!
  (lambda (image col row radius)
    (image.select-ellipse! image selection.replace
                           (- col radius) (- row radius)
                           (+ radius radius) (+ radius radius))
    (image.fill! image)
    (image.stroke! image)
    (image.select-nothing! image)))

(define draw-square!
  (lambda (image col row radius)
    (image.select-rectangle! image selection.replace
                           (- col radius) (- row radius)
                           (+ radius radius) (+ radius radius))
     (image.stroke! image)
    (image.select-nothing! image)))

(define draw-box!
  (lambda (image col row radius)
    (image.select-rectangle! image selection.replace
                           (- col radius) (- row radius)
                           (+ radius radius) (+ radius radius))
    (image.fill! image)
    (image.stroke! image)
    (image.select-nothing! image)))

(define draw-circle!
  (lambda (image col row radius)
    (image.select-ellipse! image selection.replace
                           (- col radius) (- row radius)
                           (+ radius radius) (+ radius radius))
    (image.stroke! image)
    (image.select-nothing! image)))

(define draw-stamp!
  (lambda (image col row radius rotation val)
    (cond
      ((= (modulo val 4) 1) (draw-circle! image col row radius))
      ((= (modulo val 4) 2) (draw-disc! image col row radius))
      ((= (modulo val 4) 3) (draw-square! image col row radius))
      (else
       (draw-box! image col row radius)))))

  
(define draw-rolled!
  (lambda (image col row inner-radius stamp-radius revolution val)
    (draw-stamp! image
                 (+ col (* (+ inner-radius stamp-radius) (cos revolution)))
                 (+ row (* (+ inner-radius stamp-radius) (sin revolution)))
                 stamp-radius
                 (/ (* revolution inner-radius) stamp-radius)
                 val)))

(define rgb.average
  (lambda (color1 color2)
    (rgb.new (* 0.25 (+ (rgb.red color1) (rgb.red color2)))
             (* 0.25 (+ (rgb.green color1) (rgb.green color2)))
             (* 0.25 (+ (rgb.blue color1) (rgb.blue color2))))))

(define fractal-rectangle!
  (lambda (image color left top right bottom level)
    (cond
      ((= level 0)
       (envt.set-fgcolor! color)
       (image.select-rectangle! image selection.replace
                                left top
                                (- right left)
                                (- bottom top))
       (image.fill! image)
       (image.select-nothing! image)
       (envt.update-displays!))
      (else
       (let* ((midcol1 (round (+ left (/ (- right left) 6))))
              (midcol2 (round (- right (/ (- right left) 8))))
              (midrow1 (round (+ top (/ (- bottom top) 8))))
              (midrow2 (round (- bottom (/ (- bottom top) 4)))))
         ; First row of squares
         (fractal-rectangle! image
                             (rgb.average color color.grey)
                             left top
                             midcol1 midrow1
                             (- level 1))
         (fractal-rectangle! image
                             (rgb.average color color.white)
                             midcol1 top
                             midcol2 midrow1
                             (- level 1))
         (fractal-rectangle! image
                             (rgb.average color color.grey)
                             midcol2 top
                             right midrow1
                             (- level 1))
         ; Second row of squares
         (fractal-rectangle! image
                             (rgb.average color color.white)
                             left midrow1
                             midcol1 midrow2
                             (- level 1))
         (fractal-rectangle! image
                             (rgb.average color color.grey)
                             midcol1 midrow1
                             midcol2 midrow2
                             (- level 1))
         (fractal-rectangle! image
                             (rgb.average color color.white)
                             midcol2 midrow1
                             right midrow2
                             (- level 1))
         ; Third row of squares
         (fractal-rectangle! image
                             (rgb.average color color.grey)
                             left midrow2
                             midcol1 bottom
                             (- level 1))
         (fractal-rectangle! image
                             (rgb.average color color.white)
                             midcol1 midrow2
                             midcol2 bottom
                             (- level 1))
         (fractal-rectangle! image
                             (rgb.average color color.grey)
                             midcol2 midrow2
                             right bottom
                             (- level 1))
         )))))

(define sushi-roll!
  (lambda (image val width height)
    (let kernel ((step 0)
                 (revolution 0)
                 (red (modulo val 256))
                 (green (modulo val 128))
                 (blue (modulo val 64))
                 (theta (/ pi (max (modulo val 16) 8)))
                 (col (/ width 2))
                 (row (/ height 2))
                 (inner-radius (/ 250 (/ 1000 width)))
                 (stamp-radius (/ (max 20 (modulo val 50)) (/ 1000 width))))
      (define color (rgb.new red green blue))
      (cond ((<= step (/ (* 2 pi) theta))
             
             (draw-rolled! image col row inner-radius stamp-radius revolution val)
            
             (envt.set-fgcolor! (rgb.new red green blue))
            
             (envt.set-brush! (list-ref (list "Circle (01)" "pixel (1x1 square)" "Circle Fuzzy (03)"
                                "Felt Pen" "square (5x5) blur" "Calligraphic Brush" "Sand Dunes (AP)")  (modulo val 7)))

            
             (kernel (+ step 1) (+ revolution theta) (+ red (/ step 4)) (+ green (/ step 2)) (+ blue step) theta col row inner-radius stamp-radius))))))




 (define canvas (image.new 200 200))
 (image.show canvas)
 (envt.set-bgcolor! "white")
 (envt.set-fgcolor! "white")
 (envt.update-displays!)
 (fractal-rectangle! canvas color.grey 0 0 200 200 2) 
 (sushi-roll! canvas 111 200 200) 
 (envt.update-displays!)