Space-Time Turtle Spiral Generator

Space-time representation of Turtle Geometry square spirals. Derived from the [Turtle Spiral Generator](https://www.thingiverse.com/thing:1207095) OpenSCAD code of [JustinSDK](https://www.thingiverse.com/JustinSDK). Z-axis is representing time, assuming a constant Turtle speed.

Spirals are reproducing a LOGO code of the following kind ([LibreLogo code](http://librelogo.org)):

TO SPIRAL IL EL DS A
IF IL < EL [ STOP ]
FORWARD IL
LEFT A
SPIRAL IL–DS EL DS A
END