p5js/sketches/L-System.js

let angle = 3.141592653589*1.5;
let angleDecrement = 1;
let stepSize = 10;
let widthIncrement = 1;
let currentWidth = 1;
let currentPosition = [501 / 2, 500];
let fractalst = "FF+[+F-F-F]-[-F+F+F]";
let stackList = [];
let lineLenghtScaleFactor = 1.5;
let swapPlusMinusState = false;
let turningAngleIncrement = 0.1;

//FF+[+F-F-F]-[-F+F+F] fork

function setup() {
	console.log("setup");
	createCanvas(windowWidth, windowHeight);
	background(255, 255, 255)
	noFill();
	stroke(0, 0, 0);
	strokeWeight(1);
	currentPosition = [width / 2, height];
	generateFractal();
}

function generateFractal() {
	for (let i = 0; i < fractalst.length; i++) {
		let c = fractalst.charAt(i);
		switch (c) {
			case "F":
				forward();
				break;
			case "+":
				plus();
				break;
			case "-":
				minus();
				break;
			case "f":
				forwardNoLine();
				break;
			case "|":
				reverseDirection();
				break;
			case "#":
				lineWidthIncrement();
				break;
			case "!":
				lineWidthDecrement();
				break;
			case "[":
				pushStack(i);
				break;
			case "]":
				popStack(i);
				break;
			case ">":
				lineWidthMultiply();
				break;
			case "<":
				lineWidthDivide();
				break;
			case "&":
				swapPlusMinus();
				break;
			case "@":
				drawDot();
				break;
			case ")":
				angleIncrement();
				break;
			case "(":
				angleDecrement();
				break;
			default:
				console.log("unrecognized character",c);
				break;
		}
	}
}

function minus() {
	if (swapPlusMinusState) {
		angle += angleDecrement;
		return
	}
	angle -= angleDecrement;
}

function plus() {
	if (swapPlusMinusState) {
		angle -= angleDecrement;
		return
	}
	angle += angleDecrement;
}

function lineWidthIncrement(){
	currentWidth + widthIncrement;
	strokeWeight(currentWidth);
}

function lineWidthDecrement(){
	currentWidth - widthIncrement;
	strokeWeight(currentWidth);
}

function forward() {
	let x = currentPosition[0] + cos(angle) * stepSize;
	let y = currentPosition[1] + sin(angle) * stepSize;
	line(currentPosition[0], currentPosition[1], x, y);
	currentPosition = [x, y];
}

function forwardNoLine(){
	let x = currentPosition[0] + cos(angle) * stepSize;
	let y = currentPosition[1] + sin(angle) * stepSize;
	currentPosition = [x, y];
}

function backward() {
	let x = currentPosition[0] - cos(angle) * stepSize;
	let y = currentPosition[1] - sin(angle) * stepSize;
	line(currentPosition[0], currentPosition[1], x, y);
	currentPosition = [x, y];
}

function reverseDirection(){
	angle - 3.14159265358979323;
}

function pushStack(i){
	console.log(angle)
	stackList.push([i,currentPosition[0],currentPosition[1],angle,currentWidth]);
}

function popStack(i){
	stackToPop = stackList.length - 1;
	console.log(stackList[stackToPop])
	currentPosition = [stackList[stackToPop][1],stackList[stackToPop][2]];
	angle = stackList[stackToPop][3];
	strokeWeight[stackList[stackToPop][4]]
}

function lineWidthMultiply(){
	currentWidth * lineLenghtScaleFactor;
	strokeWeight(currentWidth);
}

function lineWidthDivide(){
	currentWidth / lineLenghtScaleFactor;
	strokeWeight(currentWidth);
}

function swapPlusMinus(){
	if (swapPlusMinusState) {
		swapPlusMinusState = false;
		return
	}
	swapPlusMinusState = true;
}

function drawDot() {
	let x = currentPosition[0];
	let y = currentPosition[1];
	strokeWeight(currentWidth);
	point(x, y);
}

function angleIncrement() {
	angle += turningAngleIncrement;
}

function angleDecrement() {
	angle -= turningAngleIncrement;
}

function draw() {

}

function mousePressed() {

}