fibonacci fractal

let word = "";

function setup() {

  createCanvas(710, 500);

  colorMode(HSB, 360, 100, 100, 1.0);

  word = fibonacciWord(15);

}

​

function draw() {

  let a = map(cos(radians(frameCount)),1,-1,PI,-PI);

  a = PI/2;

  const l = 7; //map(cos(radians(frameCount)),1,-1,25,1);

  background(0, 0, 5);

  stroke(190, 85, 90);

  strokeWeight(5);

  const turtle = new Turtle(10, height - 10, l, -PI/2, a);

  for (let k = 0; k < word.length; k++) {

    turtle.forward();

    let c = word.charAt(k);

    if (c === "0") {

      if (k % 2 === 0) {

        turtle.left();

      } else {

        turtle.right();

      }

    }

  }

  // noLoop();

}

​

function fibonacciWord(n) {

  if (n === 0) return "0";

  if (n === 1) return "01";

  return fibonacciWord(n - 1) + fibonacciWord(n - 2);

}

​

class Turtle {

  constructor(x, y, l, a, ainc) {

    this.x = x;

    this.y = y;

    this.a = a || 0;

    this.ainc = ainc || PI/2;

    this.l = l;

  }

  forward() {

    // draw line

    push();

    translate(this.x, this.y);

    rotate(this.a);

    line(0, 0, this.l, 0);

    pop();

​

    // calculate new position

    const v = createVector(this.x, this.y);

    const av = p5.Vector.fromAngle(this.a);

    av.setMag(this.l);

    v.add(av);

    this.x = v.x;

    this.y = v.y;

  }

  left() {

    this.a = this.a + this.ainc;

  }

  right() {

    this.a = this.a - this.ainc;

  }

}