Crab graphics

You might wonder how these image are being drawn. This chapter will explain the connection between the words of the L-system and image being drawn.

Ferris the Crab

The artist is @whoisaldeka.

We all know and love Ferris. But did you know that Ferris is a skilled and attentive artist. Ferris is willing to lend their skill for our workshop. By listening to our instructions they will draw an image for us.

Below are the command that Ferris responds to. Each command has a corresponding symbol that Ferris knows, understands and responds to.

Forward F

The forward command will make Ferris take a step forward, leaving a line in their trail. The step size is determined by the step value of the configuration.

TurnLeft -

When the turn left command is issued Ferris will change heading accordingly. The angle through which Ferris will turn is configured with the angle value of the configuration.

TurnRight +

Correspondingly, Ferris knows about how to turn right.

Push [

Not only is Ferris a great artist, they have excellent memory. With the push command Ferris will remember their position and heading so that they are able to come back to it at a later time, i.e. when the corresponding pop command is issued.

Pop ]

What would push be without a pop? Ferris agrees and will respond to the pop command by remembering position and heading from the corresponding push command. Push and pop commands should properly match. Just like the brackets used to represents the commands.

Any other symbol

Any other symbol besides the ones described above will be ignored by Ferris. That does not mean that they aren't important. For they can help in constructing more complex drawings.