const points = 800,

  inc = 0.005,

  stars = 500;

​

let start = 100,

  rotangle = 0,

  rotangleShift = 0,

  starsx = [],

  starsy = [];

​

// Setup functiom

function setup() {

  createCanvas(windowWidth, windowHeight);

  noStroke();

​

  rotangleShift = PI / 5000;

​

  // Fill up the stars array

  for (let i = 0; i < stars; i++) {

    starsx.push(random(-width, width));

    starsy.push(random(-height, height));

  }

}

​

// Draw function

function draw() {

  let xoff = start

  background("#04072C");

​

  rotate(rotangle)

​

  // Plot the stars

  push()

  stroke(255, 125)

  for (let i = 0; i < stars; i++) {

    if (i % 4 == 0) {

      strokeWeight(random(1, 4))

    }

    point(starsx[i], starsy[i])

  }

  pop()

​

​

  // Make an array of y-points to work through

  y1Array = [];

​

  // Fill the array

  for (let i = 0; i < points; i++) {

    y1Array.push(noise(xoff) * height * 0.85);

    xoff += inc;

  }

​

  // Draw the top shape

  push()

  noStroke()

  rotate(-rotangle)

  fill("#572819")

  beginShape()

  vertex(width, height)

  for (let i = points; i > 0; i--) {

    let x = i * (width / points);

    let y = y1Array[i] - (height / 12)

    vertex(x, y);

  }

  vertex(0, height)

  endShape(CLOSE)

  pop()

​

  // Draw the bottom shape

  push()

  rotate(-rotangle)

  fill("#A75942")

  beginShape();

  vertex(0, height)

  for (let i = 0; i < points; i++) {

    let x = i * (width / points);

    let y = y1Array[floor(i / 3)] + (height / 3)

    vertex(x, y);

  }

  vertex(width, height);

  endShape(CLOSE);

  pop()

​

  // Increment the mountains passing and the stars rotating

  start += inc;

  rotangle += rotangleShift;

}