// Daniel Shiffman

// http://natureofcode.com

​

let moverA;

let moverB;

​

function setup() {

  createCanvas(640, 360);

  // A large Mover on the left side of the window

  moverA = new Mover(200, 30, 10);

  // A smaller Mover on the right side of the window

  moverB = new Mover(440, 30, 2);

  createP('Click mouse to apply wind force.');

}

​

function draw() {

  background(51);

​

  let gravity = createVector(0, 0.1);

​

  let gravityA = p5.Vector.mult(gravity, moverA.mass);

  moverA.applyForce(gravityA);

​

  let gravityB = p5.Vector.mult(gravity, moverB.mass);

  moverB.applyForce(gravityB);

​

  if (mouseIsPressed) {

    let wind = createVector(0.1, 0);

    moverA.applyForce(wind);

    moverB.applyForce(wind);

  }

​

  moverA.update();

  moverA.display();

  moverA.checkEdges();

​

  moverB.update();

  moverB.display();

  moverB.checkEdges();

}

​

// The Nature of Code

// Daniel Shiffman

// http://natureofcode.com

​

class Mover {

  constructor(x, y, m) {

    this.mass = m;

    this.radius = m * 8;

    this.position = createVector(x, y);

    this.velocity = createVector(0, 0);

    this.acceleration = createVector(0, 0);

  }

​

  applyForce(force) {

    let f = p5.Vector.div(force, this.mass);

    this.acceleration.add(f);

  }

​

  update() {

    this.velocity.add(this.acceleration);

    this.position.add(this.velocity);

    this.acceleration.mult(0);

  }

​

  display() {

    stroke(0);

    strokeWeight(2);

    fill(255, 127);

    ellipse(this.position.x, this.position.y, this.radius * 2);

  }

​

  checkEdges() {

    if (this.position.x > width - this.radius) {

      this.position.x = width - this.radius;

      this.velocity.x *= -1;

    } else if (this.position.x < this.radius) {

      this.position.x = this.radius;

      this.velocity.x *= -1;

    }

    if (this.position.y > height - this.radius) {

      this.position.y = height - this.radius;

      this.velocity.y *= -1;

    }

  }

​

}