function setup() {

  createCanvas(1000, 1000);

  background(220);

  gfxs = [];

  for (let i = 0; i < 4; i++) {

    gfxs.push({g:createGraphics(width/2,height/2),r:random(0,width)});

    gfxs[i].g.background(random(255)); 

  }

}

​

​

function draw() {

  image(gfxs[0].g,0,0);

  image(gfxs[1].g,width/2,0);

  image(gfxs[2].g,0,height/2);

  image(gfxs[3].g,width/2,height/2);

  for (let i = 0; i < 4; i++) {

    gfxs[i].g.fill(random(255));

    gfxs[i].g.ellipse(width/4,height/4,gfxs[i].r);

    gfxs[i].r += random(0.5,5.0);

    if (gfxs[i].r > width/2) gfxs[i].r = 0;

  }

}