// https://youtu.be/szztTszPp-8

​

// module aliases

const Engine = Matter.Engine;

// const Render = Matter.Render;

const World = Matter.World;

const Bodies = Matter.Bodies;

const Constraint = Matter.Constraint;

​

let engine;

let world;

let particles = [];

let boundaries = [];

​

let ground;

​

function setup() {

  createCanvas(400, 400);

  engine = Engine.create();

  world = engine.world;

​

  let prev = null;

  for (let x = 200; x < 500; x += 20) {

​

    let fixed = false;

    if (!prev) {

      fixed = true;

    }

    let p = new Particle(x, 100, 5, fixed);

    // let p2 = new Particle(200, 150, 10);

    particles.push(p);

​

    if (prev) {

      let options = {

        bodyA: p.body,

        bodyB: prev.body,

        length: 20,

        stiffness: 0.4

      }

      let constraint = Constraint.create(options);

      World.add(world, constraint);

    }

​

    prev = p;

  }

​

​

  boundaries.push(new Boundary(200, height, width, 50, 0));

}

​

​

function draw() {

  background(51);

  Engine.update(engine);

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

    boundaries[i].show();

  }

​

  for (let i = 0; i < particles.length; i++) {

    particles[i].show();

  }

}