One-a-Day: Amiga Ball Bounce
The Commodore Amiga computer had a famous ‘bouncing ball’ demonstration program, a checkered bouncing ball. It was a bit different than this, but this is certainly reminiscent of it.
We love the Amiga demo so much that we created a special checkered ball primitive, AMIGABALL, and a second ‘oid’ primitive, AMIGABALLOID, which is used to create the ‘compressed’ ball.
Rather than turning the turtle into a ball (one method), this method ‘cleans’ the ‘turtle track’ after rendering each frame of the animation (which we wait for using the NEXTFRAME primitive).