// 3D Snake - was going to have it travel thru hyperspace but distorting the body
// was just too much hassle, I quite like the result anyway.

class Snake{
  Vector body;
  Node head;
  int len, col;
  float scale;
  Snake(Node n, int len, int col, float scale){
    body = new Vector();
    head = n;
    this.len = len;
    this.scale = scale;
    this.col = col;
  }
  void draw(){
    move();
    stroke(0);
    fill(col);
    beginShape(QUADS);
    for(int i = 0; i < body.size(); i++){
      Node n = (Node)body.get(i);
      float s = scale * 0.5;
      vertex(n.x()-s, n.y()-s, n.z());
      vertex(n.x()+s, n.y()-s, n.z());
      vertex(n.x()+s, n.y()+s, n.z());
      vertex(n.x()-s, n.y()+s, n.z());

      vertex(n.x(), n.y()-s, n.z()-s);
      vertex(n.x(), n.y()+s, n.z()-s);
      vertex(n.x(), n.y()+s, n.z()+s);
      vertex(n.x(), n.y()-s, n.z()+s);

      vertex(n.x()-s, n.y(), n.z()-s);
      vertex(n.x()+s, n.y(), n.z()-s);
      vertex(n.x()+s, n.y(), n.z()+s);
      vertex(n.x()-s, n.y(), n.z()+s);
      // This next line is a hack to stop the bodies ghosting
      // It just seemed easier that whilst I have the node to hand that I double check
      // it's unwalkable.
      n.walkable = false;
    }
    endShape();
    pushMatrix();
    translate(head.x(), head.y(), head.z());
    box(scale * 1.5, scale * 1.5, scale * 1.5);
    popMatrix();
  }
  void move(){
    Vector path = aStar.getPath(head, egg.n);
    if(path.size() > 1){
      body.add(0, head);
      head = (Node)path.get(path.size()-2);
      if(len < body.size()){
        Node n = (Node)body.remove(body.size()-1);
        n.walkable = true;
      }
    }
    if(head == egg.n){
      len += (int)random(5, 10);
      egg = new Egg();
    }
  }
}