SOURCE

function setup(){
createCanvas(400,400);
background(120);
}
function draw(){
push();
translate(mouseX,mouseY);
scale(map(mouseX,0,400,0,1));
ellipse(0,0,100,100);
pop();

push();
translate(mouseX,mouseY);
scale(map(mouseX,0,400,0,2));
ellipse(200,0,200,200);
pop();

push();
translate(mouseX,mouseY);
scale(map(mouseX,0,400,0,4));
ellipse(400,0,150,150);
pop();
}