constructor(x, y) {

    this.pos = createVector(x, y); // position

    this.prev = createVector(x, y);

    //this.vel = p5.Vector.random2D(); // veloctiy

    this.vel = createVector(0, 0); // veloctiy

    //this.vel.setMag(random(2,5));

    //this.vel.setMag(random(2,5));

    this.acc = createVector(); // acceleration

  }

​

  update() {

    this.vel.add(this.acc);

    this.pos.add(this.vel);

    this.acc.mult(0);

  }

  applyForce(force) {

    this.acc.add(force);

  }

​

  show() {

    stroke(255, 25);

    strokeWeight(1);

    line(this.pos.x, this.pos.y, this.prev.x, this.prev.y);

    this.prev.x = this.pos.x;

    this.prev.y = this.pos.y

  }

​

  attracted(target) {

    // var dir = target - this.pos

    var force = p5.Vector.sub(target, this.pos);

    //var d = force.mag();

    var dsquared = force.magSq();

    dsquared = constrain(dsquared, 1, 500)

    var G = 100;

    var strength = G / dsquared;

    force.setMag(strength);

    this.applyForce(force);

  }

}