let sz = 50;

let rad = 100;

let angle;

let i = 0;

let a2 = 255

let mx = 1;

let my = 1;

let easing = 0.1;

​

function setup() {

  createCanvas(windowWidth, windowHeight);

  //background(0);

  frameRate(60);

}

​

function draw() {

  background(0,a2);

  //time operator

  i++;

  //these makes the circle lag behind the mouse 

  mx = mx + (mouseX - mx) * easing;

  my = my + (mouseY - my) * easing;

  //random colors

  //r = random(0,255);

  //g = random(0,255);

  //r = 122 + 122 * cos(i);

  //a = random(122, 255);

  r = 0;

  g = 0;

  b = random(122, 255);

  a = 255;

  //this makes the circle oscillate

  rad = 100 + 20 * sin(i/20);

  //this generate random angles

  angle = random() * PI * 2;

  //cos and sin generate the circles in the perimeter of a circle of radius = rad

  x = mx + cos(angle) * rad;

  y = my + sin(angle) * rad;

​

  //change background alpha to 0 to start drawing mode

  if (mouseIsPressed == true) {

    noStroke();

    fill(r, g, b, a);

    ellipse(x, y, sz);

    a2 = 0;

  } else {

    noStroke();

    fill(255, 255, 255, 0);

    ellipse(x, y, sz);

    a2 = 255;

​

  }

    noFill();

    stroke(255);

    ellipse(mx,my,rad)

}

​