createCanvas(windowWidth, windowHeight);

  noLoop();

}

​

function draw() {

  background(220);

  translate(width / 2, height / 2);

​

  noFill();

  strokeWeight(4);

​

  let maxRadius = min(width / 2, height / 2);

​

  for (let r = 10; r < maxRadius; r += 20) {

    let redV = map(r, 10, maxRadius, 50, 255);

    let blueV = map(r, 10, maxRadius, 255, 50);

    stroke(redV, 0, blueV);

​

    beginShape();

    for (let a = 0; a < 360; a += 1) {

      let x = r * cos(radians(2 * a + 2 * r));

      let y = r * sin(radians(a));

      vertex(x, y);

    }

    endShape(CLOSE);

  }

}

​