​

function setup() {

  createCanvas(600, 600);

  //generate path here all at once

  path = [[width/2,height/2]] //sample code

}

​

function draw() {

  background(255);

  //generate path here step by step

  path.push([random()*width,random()*height]); //sample code

  drawPath(); //draws the path

}

​

function drawPath(){

  stroke(0);

  for(let i=1;i<path.length;i++){

    line(path[i-1][0],path[i-1][1],path[i][0],path[i][1]);

  }

}