SOURCE

function setup(){
    createCanvas(600,600);
    rectMode(CENTER);
    background(230);
}
function draw(){
    background(230,1000);
    push();
    translate(100,100);
    scale(map(mouseX,0,600,0,2));
    ellipse(0,0,60,60);
    pop();
    push();
    translate(300,300);
    scale(map(mouseX,0,600,0,8));
    ellipse(0,20,80,80);
    pop();
    push();
    translate(200,200);
    scale(map(mouseX,0,600,0,16));
    ellipse(0,0,20,20);
    pop();
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/p5.js/1.1.9/p5.min.js"></script>