Exercise 2.49.  Use segments->painter to define the following primitive 
painters:

a.  The painter that draws the outline of the designated frame.

b.  The painter that draws an ``X'' by connecting opposite corners of 
    the frame.

c.  The painter that draws a diamond shape by connecting the midpoints 
    of the sides of the frame.

d.  The wave painter.

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(define outline (segments->painter (list (make-segment (make-vect 0 0) (make-vect 0 1))
                                         (make-segment (make-vect 0 1) (make-vect 1 1))
                                         (make-segment (make-vect 1 1) (make-vect 1 0))
                                         (make-segment (make-vect 1 0) (make-vect 0 0))

That is inexcusably verbose.  Better would be a function that just takes 
a list of numbers, and treats each group of four as a new segment.

(define big-x (segments->painter (list (make-segment (make-vect 0 0) (make-vect 1 1))
                                       (make-segment (make-vect 1 0) (make-vect 0 1)))))

(define diamond (segments->painter (list (make-segment (make-vect 0 0.5) (make-vect 0.5 1))
                                         (make-segment (make-vect 0.5 1) (make-vect 1 0.5))
                                         (make-segment (make-vect 1 0.5) (make-vect 0.5 0))
                                         (make-segment (make-vect 0.5 0) (make-vect 0 0.5)))))

(define wave booooring)