// put setup code here

  createCanvas(600, 600);

  background(255,0.4);

}

let xandy = [];

let straight = false;

​

function draw() {

  // put drawing code here

  stroke(0);

  noFill();

  strokeWeight(4);

  beginShape();

  for (var i = 0; i < xandy.length; i++) {

    vertex(xandy[i][0], xandy[i][1]);

  }

  endShape();

}

​

function flatten(list){

  for (var i=1; i<xandy.length-1;i++){

    xandy[i][0] = (xandy[i-1][0] + xandy[i+1][0])/2;

    xandy[i][1] = (xandy[i-1][1] + xandy[i+1][1])/2;

  }

}

​

function mousePressed(){

  if (xandy.length < 100) {

      xandy.push([mouseX, mouseY]);

    } else {

      xandy.shift();

    }

}

​

function mouseReleased(){

  flatten(xandy);

}