Ex 2.49

; a.
(define outliner
  (segments->painter
    (list (make-segment (make-vect 0 0) (make-vect 1 0))
          (make-segment (make-vect 1 0) (make-vect 0 1))
          (make-segment (make-vect 0 0) (make-vect 0 1))
          (make-segment (make-vect 0 1) (make-vect 1 0)))))

; b.
(define paint-x
  (segments->painter
    (list (make-segment (make-vect 0 0) (make-vect 1 1))
          (make-segment (make-vect 0 1) (make-vect -1 1)))))

; c.
(define paint-diamond
  (segments->painter
    (list (make-segment (make-vect 0.5 0) (make-vect 0.5 0.5))
          (make-segment (make-vect 0 0.5) (make-vect 0.5 0.5))
          (make-segment (make-vect 0 0.5) (make-vect 0.5 -0.5))
          (make-segment (make-vect 0.5 1) (make-vect 0.5 -0.5)))))

; d.
; かんべんしてください