code: function genCircles(width, height, N = 500) {
    const minR = 1;
    const maxR = Math.sqrt(width * height / N) * 0.5;
  
    return [...Array(N)].map((_, idx) => ({
      id: idx,
      x: Math.round(Math.random() * width),
      y: Math.round(Math.random() * height),
      r: Math.max(minR, Math.round(Math.random() * maxR))
    }));
  }
docs: Generate random circles