Elm – fun with L-System (Part 6)

Series:

  1. Algae
  2. Pythago­ras Tree
  3. Can­tor Dust
  4. Koch Curve
  5. Sier­pin­ski Triangle
  6. Dragon Curve (this)
  7. Frac­tal Plant

Last time out we imple­mented the Sierpinski Triangle exam­ple from the L-System wikipedia page. Now, let’s con­tinue our jour­ney and see how we can imple­ment the (rather impressive sounding) Dragon Curve exam­ple in Elm.

 

Example 6 : Dragon Curve

First, let’s define our L-System:

image

Again, thanks to the work we did in Part 4, our work here is rather simple:

image

which is a pretty straight translation of:

  • ‘F’ : draw forward
  • ‘–’ : turn left 90 degrees
  • ‘+’ : turn right 90 degrees
  • ‘X’ and ‘Y’ : ignore

Unlike the other L-Systems, this one grows much slower and as it slows it does make a nice picture!

dragon_curve

 

Live Demo (here)

Use LEFT and RIGHT arrow keys to evolve/devolve the L-System.

Source Code (here)

 

 

Next : Fractal Plant

 

Links

Enjoy what you’re reading? Subscribe to my newsletter and get more content on AWS and serverless technologies delivered straight to your inbox.


Yan Cui

I’m an AWS Serverless Hero and the author of Production-Ready Serverless. I have run production workload at scale in AWS for nearly 10 years and I have been an architect or principal engineer with a variety of industries ranging from banking, e-commerce, sports streaming to mobile gaming. I currently work as an independent consultant focused on AWS and serverless.

You can contact me via Email, Twitter and LinkedIn.

Hire me.


Check out my new course, Complete Guide to AWS Step Functions.

In this course, we’ll cover everything you need to know to use AWS Step Functions service effectively. Including basic concepts, HTTP and event triggers, activities, design patterns and best practices.

Get Your Copy