this.pos = createVector(x || random(width), y || random(height));

  this.stuck = stuck;

​

  this.walk = function () {

    let vel = p5.Vector.random2D();

    this.pos.add(vel);

    this.pos.x = constrain(this.pos.x, 0, width);

    this.pos.y = constrain(this.pos.y, 0, height);

  };

​

  this.checkStuck = function (others) {

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

      let d = distSq(this.pos, others[i].pos);

      if (d < (r * r * 4)) {

        this.stuck = true;

        return true;

        // break;

      }

    }

    return false;

  }

​

  this.show = function () {

    stroke(255, 100);

    if (this.stuck){

      fill(255, 0 , 100);

    } else {

      fill(0);

    }

    ellipse(this.pos.x, this.pos.y, r*2, r*2);

    // sphere(r);

  }

}

​

function distSq(a, b) {

  let dx = b.x - a.x;

  let dy = b.y - a.y;

  return dx * dx + dy * dy;

}

​