constructor(x, y, r) {

    this.pos = createVector(x, y);

    this.vel = p5.Vector.random2D();

    this.acc = createVector(0, 0);

    this.maxspeed = 4;

    this.maxforce = 0.1;

​

    this.r = r;

    this.col = color(random(0, 360), 100, 100);

​

    this.a = 0;

    this.velA = 0.5;

    this.accA = 0;

  }

​

  show() {

    noStroke();

    fill(this.col);

    push();

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

    this.a = this.vel.heading();

    rotate(this.a);

    triangle(0, 0, this.r * 2, this.r / 2, 0, this.r);

    pop();

  }

​

  update() {

    this.vel.add(this.acc);

    this.pos.add(this.vel);

    this.acc.set(0, 0);

  }

​

  edge() {

    if (this.pos.x > width) {

      this.pos.x = 0;

    } else if (this.pos.x < 0) {

      this.pos.x = width;

    }

    if (this.pos.y > height) {

      this.pos.y = 0;

    } else if (this.pos.y < 0) {

      this.pos.y = height;

    }

  }

​

  applyForce(force) {

    this.acc.add(force);

  }

​

  /* chasing the target */

  seek(target) {

    let seeking = p5.Vector.sub(target, this.pos);

    seeking.setMag(this.maxspeed);

    seeking.sub(this.vel);

    seeking.limit(this.maxforce);

    return seeking;

  }

​

  /* get away from the target */

  flee(target) {

    return this.seek(target).mult(-0.02);

  }

​

  /* predict future plane position*/

  pursue(plane) {

    let target = plane.pos.copy();

    let prediction = plane.vel.copy();

    prediction.mult(10);

    target.add(prediction);

​

    fill(180, 100, 100);

    circle(target.x, target.y, this.r);

​

    return this.seek(target);

  }

​

  evade(plane) {

    let pursuit = this.pursue(plane);

    pursuit.mult(-0.5);

    return pursuit;

  }

}

​

class Target extends Planes {

  constructor(x, y, r) {

    super(x, y, r);

    this.vel = p5.Vector.random2D();

    this.vel.mult(5);

  }

​

  show() {

    noStroke();

    fill(350, 100, 100);

    push();

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

    circle(0, 0, this.r * 2);

​

    pop();

  }

}

​