solid-circle

;;; (solid-circle diameter color [description]) -> image?
;;;   diameter : nonnegative-integer?
;;;   color : color?
;;;   description : string?
;;; Create a solid circle with the given diameter and color.

> (solid-circle 30 "blue")

> (solid-circle 40 "red")

> (beside (solid-circle 10 "purple")
          (solid-circle 15 "purple")
          (solid-circle 20 "purple")
          (solid-circle 25 "purple")
          (solid-circle 30 "purple"))

(define solid-circle
  (lambda (diam color (description #f))
    (solid-ellipse diam diam color 
                   (or description
                       (format "a solid ~a circle with diameter ~a"
                               (color->color-name color)
                               diam)))))

(test-true "Our circle has a description"
           (string? (image-description
                     (solid-circle 25 (rgb 10 20 30)))))

(test-equal? "Our circle has the right structure"
             (image-structure
              (solid-circle 25 (rgb 10 20 30)))
             (list 'solid-circle 25 (rgb 10 20 30)))

(test-equal? "Our circle has the right image width"
             (image-width (solid-circle 25 (rgb 10 20 30)))
             25)

(test-equal? "Our circle has the right diameter"
             (circle-diameter (solid-circle 25 (rgb 10 20 30)))
             25)