L-Systems

This project uses p5.js to implement L-Systems. L-Systems is a method that used to procedurally generate plants through recursive grammars.

Defining a Grammar

Input grammar file format for the program:

<Angle in degrees>  
<Length>  
<Reduction Factor>  
<Initial Sentence/Axiom>  
<Expansion Rules>  

To illistrate the above format, here is "Dragon Curve.txt":

90 <- Angle  
200 <- Length  
.73 <- Reduction Factor  
FX <- Initial Sentence/Axiom  
X=X+YF+ <- Expansion Rule  
Y=-FX-Y <- Expansion Rule  

From the file, the program is able to extract all information specified in order to properly store, expand, and draw the l-system.

Here are all the possible axioms/control characters for defining expansion rules and the initial axiom/sentence:

• +: Rotate by the specified angle

• -: Rotate by the negative of the specified angle

• [: Push current state of the l-system onto the matrix stack

• ]: Pop prior state of the l-system off of the matrix stack

• f: Move foward without drawing a line

• X and Y: Do nothing. Usually used for rational/angular control of the l-system

• Capital letters (expect X and Y): Move forward and draw a line.

Using the above information, the program utilizes turtle graphics rendering when creating the l-system. Examples of grammar input files can be found in the "Assets" folder.

Controls

Keyboard Controls

• Up arrow key: Changes to the next l-system

• Down arrow key: Changes to the previous l-system

• Left arrow key: Increases the angle that is used to create the l-system

• Rightarrow key: Decreases the angle that is used to create the l-system

• R: Reset l-system to the original sentence and reset canvas viewing parameters

• Z: Resets the viewing parameters

• C: Changes the color mode between RGB nad HSB on the selected l-system

Mouse Controls

• Mouse wheel: Increases or decreases the zoom of the canvas

• Left click: Click and drag on the canvas to pan

GUI Controls

• Expand button: On click, it will expand the sentence of the l-system and draw it.