// no gravity, no wind!

// https://www.youtube.com/watch?v=UHx0EoveT90

let ballArray = [];

let grav, drag, wind;

​

function setup() {

  createCanvas(400, 400);

  for (let i = 0; i < 50; ++i) {

    ballArray.push(new Ball(random(width), -30));

  }

  grav = createVector(0, 0.2);

  wind = createVector(0, 0);

  drag = createVector(0.99, 0.99);

}

​

function draw() {

  background(220);

  for (let b of ballArray) {

    b.show();

    b.move();

    b.bounce();

    b.applyForce(grav);

    b.applyForce(wind);

    b.applyDrag(drag);

  }

}

​

function mousePressed() {

  for (let b in ballArray) {

    b.loc = set(random(width), -30);

  }

}

​

class Ball {

  constructor(x, y) {

    this.x = x;

    this.y = y;

    this.loc = createVector(x, y);

    //this.xspeed = 0;

    //this.yspeed = 1;

    this.speed = createVector(0,random(0.66,1));

    this.r = 15;

  }

  show() {

    ellipse(this.loc.x, this.loc.y, this.r * 2);

  }

  move() {

    //this.x += this.xspeed;

    //this.y += this.yspeed;

    this.loc.add(this.speed);

  }

  bounce() {

    if (this.loc.y >= height - this.r) {

      this.loc.y = height - this.r;

      this.speed.y *= -1;

    }

    if (this.x >= width - this.r) {

      this.loc.x = width - this.r;

      this.speed.x *= -1;

    }

  }

  applyForce(f) {

    this.speed.add(f);

    //grav.y += 0.00005;

  }

  applyDrag(d) {

    this.speed.mult(d);

  }

}

​