It also has neat behavior that allows the shape to distort in useful ways. See below when I move the green point.
Please expose creation of these green control points so we can make our own things like:
* stretchable flag (like the flag pole stretches, and not the flag itself)
* stretchable pencil (that only stretches the pencil body, not the eraser and head)
* stretchable frame (that maintains a fixed frame border width)
* stretchable alphabet (letters that stretch differently on green control points)
* stretchable sign (to widen just the area where text will go)
* etc you get the point.