(define create-drawing 
  (lambda (filename val1 val2 val3) 
    (let ((leg-height (+ 60 (* 3.33 val1))) 
          (leg-width 8) 
          (body-height (+ 60 (* 6 val1))) 
          (body-width 130) 
          (head-diameter 50) 
          (spot1-diameter (+ 1 (* 4 val2))) 
          (spot2-diameter (+ 20 (* 2 val3))) 
          (spot1-color (rgb.new (* 10 (random 25)) 
                                (+ 150 (* val1 val2)) 
                                (random 255))) 
          (spot2-color (rgb.new (* (abs (cos val3)) 255) 
                                (random 255) 
                                (* 2 (* val1 (/ val2 (+ val3 1)))))) 
          (leg-color (rgb.new (* 28 val1) 
                              (+ 100 (* 10 val2)) 
                              (- 100 (* 10 val3)))) 
          (body-color (rgb.new (+ 128 (* pi val1)) 
                               (modulo (* 100 val3) 255) 
                               (- 200 (* 20 val2)))) 
          (head-color (rgb.new (modulo (* 50 val3) 255) 
                               (random 255) 
                               (* 255 (abs (sin val1))))) 
          (line-color (rgb.new (random 255) 
                               (random 200) 
                               (random 150))) 
          (brushes (list "Circle (09)" "Circle (05)" "Circle (13)" "Circle Fuzzy (07)" "Circle Fuzzy (11)" "square (5x5)" "Circle Fuzzy (09)" "square (5x5) blur" "Pencil Sketch#2" "Circle Fuzzy (05)"))
          
          (cow-port (open-output-file filename))) 
      (filled-rectangle.write cow-port 
                              leg-color 
                              42 
                              110 
                              leg-width 
                              leg-height) 
      (filled-rectangle.write cow-port 
                              leg-color 
                              150 
                              110 
                              leg-width 
                              leg-height) 
      (filled-ellipse.write cow-port 
                            body-color 
                            35 
                            (- 100 (* 0.5 body-height)) 
                            body-width 
                            body-height) 
      (filled-circle.write cow-port 
                           head-color 
                           5 
                           50 
                           head-diameter) 
      (filled-circle.write cow-port 
                           spot1-color 
                           60 
                           80 
                           spot1-diameter) 
      (filled-circle.write cow-port 
                           spot2-color 
                           110 
                           100 
                           spot2-diameter) 
      (line.write cow-port 
                  line-color 
                  (list-ref brushes val2) 
                  165 
                  100 
                  195 
                  130) 
      (empty-circle.write cow-port 
                          line-color 
                          (list-ref brushes val3) 
                          5 
                          50 
                          head-diameter) 
      (empty-circle.write cow-port 
                          line-color 
                          (list-ref brushes val1) 
                          25 
                          65 
                          5) 
      (line.write cow-port 
                  line-color 
                  (list-ref brushes val2) 
                  12 
                  90 
                  30 
                  80))))