// initialize coordinates

  this.posX = 0;

  // this.posY = random(-50, 0);

 this.posY = height/2.5; // control the snow height

  this.initialangle = random(0, 2 * PI);

  this.size = random(2, 5);

​

  // radius of snowflake spiral

  // chosen so the snowflakes are uniformly spread out in area

 let snow_width = 130; // control the snow width

  this.radius = sqrt(random(pow(width / 2, 2)))-snow_width;

​

  this.update = function(time) {

    // x position follows a circle

    let w = 0.4; // angular speed

    let angle = w * time + this.initialangle;

    this.posX = width / 2 + this.radius * sin(angle);

​

    // different size snowflakes fall at slightly different y speeds

    this.posY += pow(this.size, 0.5);

​

    // delete snowflake if past end of screen

    if (this.posY > height) {

      let index = snowflakes.indexOf(this);

      snowflakes.splice(index, 1);

    }

  };

​

  this.display = function() {

    fill(255,255,255,95)

    ellipse(this.posX, this.posY, this.size);

  };

}