let pg;

function setup() {

  createCanvas(windowWidth, windowHeight);

  pg = createGraphics(windowWidth, windowHeight);

  for (var i = 0; i < 200; i++) {

    drops[i] = new Drop();

  }

}

​

function draw() {

  clear();

  pg.fill(255, 255, 0);

  pg.ellipse(mouseX, mouseY, 100, 100);

  //  pg.clear();

  // pg.background(0,0);

  pg.fill(0, 10);

  pg.rect(0, 0, width, height);

  for (var i = 0; i < 200; i++) {

    drops[i].show();

    drops[i].update();

  }

  image(pg, 0, 0);

}

​

function Drop() {

  this.x = random(0, width);

  this.y = random(0, -height);

​

  this.show = function () {

    pg.noStroke();

    pg.fill(112, 182, 234);

    pg.ellipse(this.x, this.y, 2, 10);

  };

​

  this.update = function () {

    this.speed = random(5, 15);

    this.gravity = 0.85;

    this.y = this.y + this.speed * this.gravity;

​

    if (this.y > height) {

      this.y = random(0, -height);

    }

  };

}

​