L- Schemer

L-Schemer is a simple piece of software written in Chicken Scheme that is designed to facilitate the rendering of L-Systems with turtle graphics. The software was built on top of the simple-graphics egg.

Building L-Schemer

In order to compile L-Schemer one needs to run csc repl.scm in the directory

Using L-Schemer

There are two ways to use L-Schemer, one can use the filename of a source file as the parameter for "repl"

./repl filename

One can also simply pass parameters to the REPL (see "content/help.txt" for more info)

lscm> IMPORT JSON examples/json/koch.json koch
lscm> IMPORT RULESET examples/rulesets/koch.ruleset koch
lscm> RENDER koch 0.01 6

Data representation with JSON and "ruleset" files

JSON files

In order to use L-Schemer one must import the L-system data in the form of a JSON file. For more information about the meanings of the individual parameters, please read the Wikipedia subsection on the structure of L-systems.

{
        "variables":["F"],     
        "constants":["+", "-"],
        "axiom":"F",
        "rules":{"F":"F+F-F-F+F"}       
}

As you can see, variables and constants are represented by an array of strings, axioms by strings, and rules by hashmaps.

Ruleset Files

Ruleset files of Scheme-style alists, with keys being the variables and constants of a specific L-system and the values being Scheme commands for rendering them (see simple-graphics for more detail.

("F" . (forward 1))            
("+" . (left 90))              
("-" . (right 90))

Images

Sierpinski triangle rendered in L-Schemer

Koch curve partially rendered in L-Schemer