let movers = [];

​

// Liquid

//let liquid;

​

function setup() {

  createCanvas(640, 650);

  reset();

  // Create liquid object

  //liquid = new Liquid(0, height / 2, width, height / 2, 0.1);

}

​

​

​

function draw() {

  background(255);

​

  // Draw water

  //liquid.display();

​

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

​

    /*

    if (liquid.contains(movers[i])) {

      let dragForce = liquid.calculateDrag(movers[i]);

​

      movers[i].applyForce(dragForce);

    }

*/

    // Gravity is scaled by mass here!

    let gravity = createVector(0, 0.1 * movers[i].mass);

    // Apply gravity

    movers[i].applyForce(gravity);

​

    // Update and display

    movers[i].update();

    movers[i].display();

    movers[i].checkEdges();

  }

​

}

​

​

function mousePressed() {

  reset();

}

​

​

​

​

// Restart all the Mover objects randomly

function reset() {

  for (let i = 0; i < 1; i++) {

    movers[i] = new Mover(random(2, 5), width/2 + i * 70, 0);

  }

}

​

​

​

​

​

​

​

/*

let Liquid = function(x, y, w, h, c) {

  this.x = x;

  this.y = y;

  this.w = w;

  this.h = h;

  this.c = c;

};

*/

​

/*

Liquid.prototype.contains = function(m) {

  let l = m.position;

  return l.x > this.x && l.x < this.x + this.w &&

         l.y > this.y && l.y < this.y + this.h;

};

*/

​

​

​

​

​

/*

// Calculate drag force

Liquid.prototype.calculateDrag = function(m) {

  // Magnitude is coefficient * speed squared

  let speed = m.velocity.mag();

  let dragMagnitude = this.c * speed * speed;

​

  // Direction is inverse of velocity

  let dragForce = m.velocity.copy();

  dragForce.mult(-1);

​

  // Scale according to magnitude

  // dragForce.setMag(dragMagnitude);

  dragForce.normalize();

  dragForce.mult(dragMagnitude);

  return dragForce;

};

​

Liquid.prototype.display = function() {

  noStroke();

  fill(50);

  rect(this.x, this.y, this.w, this.h);

};

*/

​

​

​

​

​

​

​

function Mover(m, x, y) {

  this.mass = m;

  this.position = createVector(x, y);

  this.velocity = createVector(0, 0);

  this.acceleration = createVector(0, 0);

}

​

// Newton's 2nd law: F = M * A

// or A = F / M

Mover.prototype.applyForce = function(force) {

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

  this.acceleration.add(f);

};

​

Mover.prototype.update = function() {

  // Velocity changes according to acceleration

  this.velocity.add(this.acceleration);

  // position changes by velocity

  this.position.add(this.velocity);

  // We must clear acceleration each frame

  this.acceleration.mult(0);

};

​

​

Mover.prototype.display = function() {

  stroke(200);

  //strokeWeight(2);

  noStroke();

  fill(40);

  ellipse(this.position.x, this.position.y, this.mass * 16, this.mass * 16);

};

​

​

// Bounce off bottom of window

Mover.prototype.checkEdges = function() {

  if (this.position.y > (height - this.mass * 8)) {

    // A little dampening when hitting the bottom

    this.velocity.y *= -0.5;

    this.position.y = (height - this.mass * 8);

  }

};