// Attraction
// Daniel Shiffman <http://www.shiffman.net>

// A class to describe a Food in our world, has vectors for location, velocity, and acceleration
// Also includes scalar values for mass, maximum velocity, and elasticity

class Food {
  Vector3D loc;
  Vector3D vel;
  Vector3D acc;
  float mass;
  float max_vel;
  float bounce = 5.0f; // How "elastic" is the object
  float G;             // Universal gravitational constant
  int timer;
  boolean eaten = false;
  boolean dead = false;

  Food(Vector3D a, Vector3D v, Vector3D l, float m_) {
    acc = a.copy();
    vel = v.copy();
    loc = l.copy();
    mass = m_;
    max_vel = 3.0f;
    G = 0.1f;
  }

  // Main method to operate object
  void run() {
    update();
    render();
  }
  Vector3D getLoc() {
    return loc;
  }


  Vector3D getVel() {
    return vel;
  }
  float getMass() {
    return mass;
  }

  Vector3D calcGravForce(Food f) {
    Vector3D dir = Vector3D.sub(f.getLoc(), loc);     // Calculate direction of force
    float d = dir.magnitude();                        // Distance between objects
    d = constrain(d,100.0f,200.0f);                      // Limiting the distance to eliminate "extreme" results for very close or very far objects
    dir.normalize();                                  // Normalize vector (distance doesn't matter here, we just want this vector for direction)
    float force = (G * mass * f.getMass()) / (d * d); // Calculate gravitional force magnitude
    dir.mult(force);                                  // Get force vector --> magnitude * direction
    return dir;
  }

  void add_force(Vector3D force) {
    force.div(mass);
    acc.add(force);
    if (showVectors) {
      drawVector(force,loc,1000);
    }    
  }

  float getX(){
    return loc.x;
  }

  float getY(){
    return loc.y;
  }

  void setAcc(Vector3D v) {
    acc = v.copy();
  }


  // Method to update location
  void update() {
    px = loc.x;
    py = loc.y;
    vel.add(acc);
    vel.limit(max_vel);
    loc.add(vel);
    acc.setXYZ(0.0,0.0,0.0);
  }

  // Method to display
  void render() {
    ellipseMode(CENTER);
    noStroke();

    float nw;
    float nh ;

    xoff += 0.5;
    yoff += 0.5;

    noStroke();

    nw = noise(xoff) * 3 + 3/3;
    nh = noise(yoff) * 3 + 3/2;

    if (eaten) {
      fill(noise(xoff)*5+200,noise(xoff)*5+180,noise(xoff));
      //ellipse(loc.x + nw/2, loc.y,nw,nh); 
      if (timer%10 == 0){
        dead = true;
      }
    }
    else{
      //Center ellipse
      fill(noise(xoff)*10+250,noise(xoff)*10+250,noise(xoff));
      ellipse(loc.x,loc.y,nw/2,nh);
      //wings
      ellipse(loc.x + nw/2, loc.y,nw/3,nh*2); 
      ellipse(loc.x - nw/2, loc.y,nw/3,nh*2);
      eaten = false;
      dead = false;
    }

    timer++;
  }

  void die(){
    eaten = true;
  }

  boolean dead(){
    return dead;
  }
}