​

class Particle {

​

  constructor(x, y) {

    this.pos = createVector(x, y);

    this.prev = createVector(x, y);

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

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

    //this.vel.setMag(random(2, 5));

    this.acc = createVector();

  }

​

  update() {

    this.vel.add(this.acc);

    this.vel.limit(5);

    this.pos.add(this.vel);

    this.acc.mult(0);

  }

​

  show() {

    stroke(255, 255);

    strokeWeight(4);

    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();

    d = constrain(d, 1, 25);

    var G = 50;

    var strength = G / (d * d);

    force.setMag(strength);

    if (d < 20) {

      force.mult(-10);

    }

    this.acc.add(force);

  }

​

}