createCanvas(windowWidth, windowHeight);

  rectMode(CENTER);

  angleMode(DEGREES);

}

​

function draw() {

    // changing background color

      var r = map(sin(frameCount), -1, 1, 50, 255)

      var g = map(cos(frameCount /2), -1, 1, 50, 255)

      var b = map(sin(frameCount /9), -1, 1, 50, 255)

  background(r,g,b);

  noFill();

  // posisiton of the rect

  translate(width/2, height/2);

  // translate(mouseX, mouseY);

  for(var i = 0; i < 200; i++)

    {

      push()

      //rotation (100 is the rotation speed)

      rotate(sin(frameCount + i ) * 100)

      // rect stroke colors

      var r = map(sin(frameCount), -1, 1, 50, 255)

      var g = map(cos(frameCount /6), -1, 1, 50, 255)

      var b = map(sin(frameCount /2), -1, 1, 50, 255)

      stroke(r,g,b)

      rect(0, 0, 600 - i * 3, 600 -i * 3, 200 - i)

      pop()

    }

}

​

​