Parameterized cable tidy via Turtle Commands

Constructing irregular polygons is possible using CSG operations, or even by computing the absolute positions of the vertices of the boundary. An alternative is to use relative 'turtle graphics' commands to walk the boundary and then convert these steps to a polygon and hence to a 3D object
The examples are designs for a cable tidy.
The first is a simple one polygon design. The second uses two joined polygons for a better design. It also uses a simplified turtle language which is quicke