​

function setup() {

  createCanvas(600, 400);

    background(51);

}

​

function draw() {

  if (mouseIsPressed) {

        stroke(c);

    line(mouseX, mouseY, pmouseX, pmouseY);

  }

​

    noStroke();

  //draw the first button

  fill("yellow");

  rect(0, 0, 40, 40);

​

  //draw the second button

  fill("aqua");

  rect(40, 0, 40, 40);

}

​

//this will run whenever the mouse is pressed

function mousePressed() {

  if (mouseX > 0 && mouseX < 40 && mouseY > 0 && mouseY < 40) {

    //set the variables to random values

    c = "yellow";

  }

  if (mouseX > 40 && mouseX < 80 && mouseY > 0 && mouseY < 40) {

    //set the variables to random values

    c = "aqua";

  }

}