Exercises for the fabric teachpack

0. Familiarize yourself with the images and functions in the
teachpack.  Enter the names of the images one at a time in the
interactions window.  Try the functions that create fabric images
(create-solid-fabric, add-print, add-horiz-stripe, and
add-vertical-stripe) to see what each one does.

1. Write an expression to create blue fabric with red stripes in one
direction and purple stripes in the other (you pick the size).

2. Write an expression to create a small green stripe fabric with a
chili print on it (you pick the size).

3. Invent two fabrics of your own using the teachpack functions.  You
can create your own print images using the circle and rectangle
operators from the image teachpack (they are included in this
teachpack).  Each fabric should involve at least two calls to
functions that create fabrics.  Be creative!

4. Write a function create-from-fabric that consumes an image for a
white clothing item (like the tshirt or hat) and a fabric image sized
to fit that item and produces an image of the clothing item in the
given fabric.

5. Write a function add-center-logo that consumes an image for a logo
and an image for a clothing item and produces an image of the clothing
item with the logo centered on it.  The given clothing item may
already be printed in fabric.

6. Write a function stack-logos that consumes images of two logos and
returns an image with the first logo just above the second logo. You
do not need to center the logos, but you may if you wish. 

7. Write a function side-by-side-logos that consumes images of two
logos and returns an image with the first logo to the left of the
second logo. You do not need to center the logos, but you may if you
wish.  

8. Define three pieces of clothing using a combination of the
teachpack functions and your definitions.  You should use each of the
functions you defined at least once.  Again, be creative!