// Daniel Shiffman

// http://natureofcode.com

​

class Mover {

  constructor(x, y, mass) {

    this.mass = mass;

    this.radius = mass * 8;

    this.position = createVector(x, y);

    this.velocity = createVector(1, 0);

    this.acceleration = createVector(0, 0);

  }

  // Newton's 2nd law: F = M * A

  // or A = F / M

  applyForce(force) {

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

    this.acceleration.add(f);

  }

​

  update() {

    // Velocity changes according to acceleration

    this.velocity.add(this.acceleration);

    // position changes by velocity

    this.position.add(this.velocity);

    this.velocity.mult(0.19);

    // We must clear acceleration each frame

    this.acceleration.mult(0);

  }

​

  display() {

    stroke(0);

    strokeWeight(2);

    fill(255, 127);

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

  }

}