Render = Matter.Render,

  World = Matter.World,

  Bodies = Matter.Bodies;

var engine;

var world;

var circles = [];

var boundaries = [];

​

function setup() {

  createCanvas(400, 400);

  engine = Engine.create();

  world = Engine.world;

  Engine.run(engine);

  boundaries.push(new Boundary(200, 400, 400, 20)); //底の壁生成

  boundaries.push(new Boundary(0, 0, 20, 800)); //左端の壁生成

  boundaries.push(new Boundary(400, 0, 20, 800)); //右端の壁生成

​

  let count = 0;

  const autoDrop = () => {

    circles.push(new Circle(random(400), // x座標

                            random(100), // y座標

                            random(5, 5), // ボールの大きさ

                            "#FFFFFF")); // 色

    setTimeout(autoDrop, 1000);

  };

  autoDrop();

}

​

function mouseClicked() {}

​

function draw() {

  background(51);

  Engine.update(engine);

  for (var i = 0; i < circles.length; i++) {

    circles[i].show();

  }

  for (var i = 0; i < boundaries.length; i++) {

    boundaries[i].show();

  }

}

​