let stamp;

let topLayer;

​

function preload() {

  img = loadImage("image.png");

  stamp = loadImage("stamp.png");

}

​

function setup() {

  createCanvas(600, 600);

  topLayer = createGraphics(width, height);

  topLayer.background(200);

  topLayer.textSize(50);

  topLayer.textAlign(CENTER);

  topLayer.text("SCRATCH ME", width/2, height/2);

  topLayer.imageMode(CENTER);

  topLayer.strokeWeight(40);

  topLayer.blendMode(REMOVE);  

}

​

function draw() {

  image(img, 0, 0, width, height);

  if(mouseIsPressed) {

    topLayer.line(pmouseX, pmouseY, mouseX, mouseY);

    // topLayer.image(stamp, mouseX, mouseY, stamp.width * 2, stamp.height*2);

  }

  image(topLayer, 0, 0);

}