Turtle Bezier Path - iOS App Source Code
TurtleBezierPath is a UIBezierPath subclass for Turtle Graphics: a simple, intuitive drawing system developed my Seymour Papert for the Logo programming language.
The Turtle is a drawing cursor that follows the commands: home, turn, forward, leftArc, rightArc, up and down. As the Turtle moves, it draws a path in its wake. Many shapes are much easier to draw this way.