Now that we're getting somewhere, our code's getting a bit
too big for a single screen, so we'll start sticking some of it into a library
of functions to make our lives easier. In future pages, expect the library code
to be sitting hidden on the page so that we can focus on our draw() function.
Just click on the library tab to review it at any time.
See how much simpler the draw() function is now?
If you edit the library, the changes will be reflected when you hit
"run code", just like they are with the code box right now.