​

let x1;

let y1; 

let x2;

let y2; 

let startTime;

let sketchTime = 5000;

​

function setup() {

  frameRate(24);

  createCanvas(windowWidth, windowHeight);

  background(235);

​

  x1 = 0;

  y1 = height / 2;

  x2 = width;

  y2 = height / 2;

​

  startTime = millis();

}

​

function draw() {

  let elapsedTime = millis() - startTime;

​

  if (elapsedTime < sketchTime) {

    let percentDone = map(elapsedTime, 0, sketchTime, 0, 1);

    let x = lerp(x1, x2, percentDone) + random(-200, 0);

    let y = y1 + random(-40, 40); 

​

    stroke(0,20,150);

    strokeWeight(4);

    line(x1, y1, x, y);

    x1 = x;

    y1 = y;

  } else {

​

    line(x1, y1, x2, y2);

  }

}

​