var prev;

function setup() {

  createCanvas(400, 400);

  pos=createVector(width/2,height/2);

  prev = pos.copy();

  background(0);

}

​

function draw() {

  stroke(random(0, 200), random(0, 240), random(0, 250));

  strokeWeight(random(0,2));

  line(pos.x, pos.y, prev.x, prev.y);

  prev.set(pos);

 var step = p5.Vector.random2D();

var r = random(100);

  if (r < 1.5) {

    step.mult(random(25, 100));

  } else {

    step.setMag(1);

  }

 pos.add(step);

}