let img;
let imgWidth = 100;
let imgHeight = 0;

function setup() {
  createCanvas(400, 300);
  imageMode(CENTER);

  // Promisify this function
  img = loadImage('assets/light.jpg', (loadedImage) => {
    const ratio = loadedImage.height / loadedImage.width;
    loadedImage.height = imgWidth * ratio;
    loadedImage.width = imgWidth;
  });
}

function draw() {
  background(255);
  if (img) image(img, width / 2, height / 2);
}