class Particle {
  PVector location;
  PVector velocity;
  PVector acceleration;
  PVector gravity;

  Particle() {
    location = new PVector(width/2, 0);
    velocity = new PVector(0, 0);
    acceleration = new PVector(random(-.3, .3), 0);
    gravity = new PVector(0, 0.01);
  }

  void update() {
    acceleration.add(gravity);
    velocity.add(acceleration);
    location.add(velocity);
  }

  boolean isOutOfBounds() {
    if (location.x > width || location.x < 0 || location.y > height || location.y < 0) {
      return true;
    } else {
      return false;
    }
  }

  void display() {
    pushMatrix();
    translate(location.x, location.y);
    ellipse(0, 0, 20, 20);
    popMatrix();
  }
}