constructor(x, y) {

    //all the usual stuff

    this.position = createVector(x, y);

    this.r = 12;

    this.maxspeed = 3; //max speed

    this.maxforce = 0.2; //max steering force

    this.acceleration = createVector(0, 0);

    this.velocity = createVector(0, 0);

  }

​

  applyForce(force) {

    //add mass here if we want A = F / M

    this.acceleration.add(force);

  }

​

  //separation

  //method checks for nearby vehicles and steers away

  separate(vehicles) {

    let desiredseparation = this.r * 2;

    let sum = createVector();

    let count = 0;

    //for every boid in the system, check if it's too close

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

      let d = p5.Vector.dist(this.position, vehicles[i].position);

      //if the distance is greater than 0 and less than an arbitrary amount (0 when you are yourself)

      if ((d > 0) && (d < desiredseparation)) {

        //calculate vector pointing away from neighbor

        let diff = p5.Vector.sub(this.position, vehicles[i].position);

        diff.normalize();

        diff.div(d); //weight by distance

        sum.add(diff);

        count++; //keep track of how many

      }

    }

    //average: divide by how many

    if (count > 0) {

      sum.div(count);

      //our desired vector is the average scaled to max speed

      sum.normalize();

      sum.mult(this.maxspeed);

      //implement Reynolds: steering = desired - velocity

      let steer = p5.Vector.sub(sum, this.velocity);

      steer.limit(this.maxforce);

      this.applyForce(steer);

    }

  }

​

  //method to update location

  update() {

    //update velocity

    this.velocity.add(this.acceleration);

    //limit speed

    this.velocity.limit(this.maxspeed);

    this.position.add(this.velocity);

    //reset accelertion to 0 each cycle

    this.acceleration.mult(0);

  }

​

  display() {

    fill(63,63,147);

    stroke(50);

    strokeWeight(2);

    push();

    translate(this.position.x, this.position.y);

    ellipse(0, 0, this.r, this.r);

    pop();

  }

​

  //wraparound

  borders() {

    if (this.position.x < -this.r) this.position.x = width + this.r;

    if (this.position.y < -this.r) this.position.y = height + this.r;

    if (this.position.x > width + this.r) this.position.x = -this.r;

    if (this.position.y > height + this.r) this.position.y = -this.r;

  }

}