forces,

    previousMouseX,

    previousMouseY;

​

function setup() {

  createCanvas(400, 400);

  bodies = [];

  for (let i = 0; i < 10; i++) {

    bodies.push(new Body(random(100, 800)));

  }

  forces = [

    function(body) {

      // Gravity

      return p5.Vector.mult(createVector(0, 0.5), body.mass);

    },

    function(body) {

      // Ground friction

      let friction = createVector(0, 0);

      if (height - (body.position.y + body.radius) < 1) {

        friction = body.velocity.copy();

        friction.normalize();

        friction.mult(-1);

        friction.setMag(0.2 * body.mass);

      }

      return friction;

    },

    function(body) {

      // Air friction

      friction = body.velocity.copy();

      friction.normalize();

      friction.mult(-1);

      friction.setMag(0.1 * body.mass);

      return friction;

    }

  ];

  previousMouseX = mouseX;

  previousMouseY = mouseY;

}

​

function draw() {

  background(22);

  for (const body of bodies) {

    for (const force of forces)

      body.applyForce(force(body));

    body.update();

    body.edges();

    body.show();

  }

}

​

function mouseMoved() {

  if (mouseIsPressed) {

    for (const body of bodies) {

      if (dist(body.x, body.y, mouseX, mouseY) <= body.radius) {

        body.overwriteVelocity(p5.Vector.sub(createVector(mouseX, mouseY), createVector(previousMouseX, previousMouseY)));

        body.update();

      }

    }

  }

  previousMouseX = mouseX;

  previousMouseY = mouseY;

}

​