/*
  	Perform Simulation
  */
  public void simulate(float dt) {
    // Accelerate angular speed
    float requiredSpeed = targetAngularSpeed - angularSpeed;
    float angularAccel = requiredSpeed / dt;
    angularAccel = PApplet.constrain(angularAccel, -maxAngularAccel, maxAngularAccel);

    // Limit Angular speed
    angularSpeed += angularAccel * dt;
    angularSpeed = PApplet.constrain(angularSpeed, -maxAngularSpeed, maxAngularSpeed);

    // Orientation Simulation
    orientation += angularSpeed * dt;

    // Position simulation
    PVector worldRequiredSpeed = targetSpeed.get();
    worldRequiredSpeed.rotate(orientation);
    worldRequiredSpeed.sub(speed);

    // PVector worldRequiredSpeed = worldTargetSpeed.get();
    float dSpeed = worldRequiredSpeed.mag();
    float dAcell = dSpeed / dt;
    float dForce = Math.min(dAcell * getMass(), motorForce);

    worldRequiredSpeed.normalize();
    worldRequiredSpeed.mult(dForce);
    force.add(worldRequiredSpeed);

    super.simulate(dt);
  }
 // Constructor initialize all values
 Boid(PVector l, float ms, float mf) {
   loc = l.get();
   r = 4.0f;
   maxspeed = ms;
   maxforce = mf;
   acc = new PVector(0, 0);
   vel = new PVector(maxspeed, 0);
 }
    public void avoid(ArrayList obstacles) {

      // Make a vector that will be the position of the object
      // relative to the Boid rotated in the direction of boid's velocity
      PVector closestRotated = new PVector(sight + 1, sight + 1);
      float closestDistance = 99999;
      Obstacle avoid = null;

      // Let's look at each obstacle
      for (int i = 0; i < obstacles.size(); i++) {
        Obstacle o = (Obstacle) obstacles.get(i);

        float d = PVector.dist(loc, o.loc);
        PVector dir = vel.get();
        dir.normalize();
        PVector diff = PVector.sub(o.loc, loc);

        // Now we use the dot product to rotate the vector that points from boid to obstacle
        // Velocity is the new x-axis
        PVector rotated = new PVector(diff.dot(dir), diff.dot(getNormal(dir)));

        // Is the obstacle in our path?
        if (PApplet.abs(rotated.y) < (o.radius + r)) {
          // Is it the closest obstacle?
          if ((rotated.x > 0) && (rotated.x < closestRotated.x)) {
            closestRotated = rotated;
            avoid = o;
          }
        }
      }

      // Can we actually see the closest one?
      if (PApplet.abs(closestRotated.x) < sight) {

        // The desired vector should point away from the obstacle
        // The closer to the obstacle, the more it should steer
        PVector desired =
            new PVector(closestRotated.x, -closestRotated.y * sight / closestRotated.x);
        desired.normalize();
        desired.mult(closestDistance);
        desired.limit(maxspeed);
        // Rotate back to the regular coordinate system
        rotateVector(desired, vel.heading2D());

        // Draw some debugging stuff
        if (debug) {
          stroke(0);
          line(loc.x, loc.y, loc.x + desired.x * 10, loc.y + desired.y * 10);
          avoid.highlight(true);
        }

        // Apply Reynolds steering rules
        desired.sub(vel);
        desired.limit(maxforce);
        acc.add(desired);
      }
    }
  public void setState(PVector position, float orientation, boolean resetAll) {
    this.position = position.get();
    this.orientation = orientation;

    if (resetAll) {
      this.force = new PVector();
      this.accel = new PVector();
      this.speed = new PVector();
    }
  }
    // This constructor could be improved to allow a greater variety of pendulums
    Pendulum(PVector origin_, float r_) {
      // Fill all variables
      origin = origin_.get();
      r = r_;
      theta = 0.0f;

      // calculate the location of the ball using polar to cartesian conversion
      float x = r * sin(theta);
      float y = r * cos(theta);
      loc = new PVector(origin.x + x, origin.y + y);
      theta_vel = 0.0f;
      theta_acc = 0.0f;
      damping = 0.995f; // Arbitrary damping
      ballr = 16.0f; // Arbitrary ball radius
    }
 // deep copy
 public PositionRotation clone() {
   return new PositionRotation(position.get(), rotation.get());
 }