​

function setup() {

  createCanvas(400, 400);

  for (let i=0;i<20;i++){

    let x=random(100);

    let y=random(100);

    let r=random(20,30);

    let xspeed=random(1,3)

    let yspeed=random(5,10)

  balls[i]=new Ball(x,y,r,xspeed,yspeed);

  }

}

​

function draw() {

  background(220);

  for (let i=0;i<balls.length;i++){

    balls[i].move();

    balls[i].show();

  }

}

​

class Ball{

  constructor(x,y,r,xspeed,yspeed){

    this.x=x;

    this.y=y;

    this.r=r;

    this.xspeed=xspeed;

    this.yspeed=yspeed;

}

    move(){

    this.x += this.xspeed;

    this.y += this.yspeed;

    this.xspeed = this.bounce(this.x, 0, width,this.xspeed);

  this.yspeed = this.bounce(this.y, 0, height, this.yspeed);

  }

    show(){

    fill("red");

    ellipse(this.x,this.y,this.r);

  }

    bounce(pos, low, high, speed){

  if (pos< low || pos> high){

    return speed*= -1;

  }else return speed;

  }

​

}