/*! 
    \file p_node.h
    \brief Definition of a parenting node

    parenting is how coordinates are handled in orxonox, meaning, that all coordinates
    are representet relative to another parent node. this nodes build a parenting
    tree of one-sided references (from up to down referenced).
    Every node manages itself a list of childrens (of whos it is parent - easy...)

    absCoordinate, absDirection have to be recalculated as soon as there was a change in
    place or ortientation. this is only the case if 
    o bDirChanged is true (so changed) AND timeStamp != now
    o bCoorChanged is true (so moved) AND timeStamp != now
    this conditions make it cheaper to recalculate the tree (reduces redundant work).

    remember: if you have to change the coordinates, because the object (point) did move,
    don't forget to reset both relCoor and absCoor (offset is the same)
*/


#ifndef _P_NODE_H
#define _P_NODE_H

#include "stdincl.h"


class PNode {

 public:
  PNode ();
  ~PNode ();

  Vector getRelCoor ();
  void setRelCoor (Vector relCoord);
  Vector getAbsCoor ();
  void setAbsCoor (Vector absCoord);

  Quaternion getRelDir ();
  void setRelDir (Quaternion relDir);
  Quaternion getAbsDir ();
  void setAbsCoor (Quaternion absDir);

  void addChild (PNode* pNode);
  void removeChild (PNode* pNode);

 private:
  long timeStamp; //! this the timeStamp of when the abs{Coordinat, Direction} has been calculated
  bool bCoorChanged;
  bool bDirChanged;

  Vector relCoordinate;  //! coordinates relative to the parent
  Vector absCoordinate; //! absolute coordinates in the world ( from (0,0,0) )
  Quaternion relDirection; //! direction relative to the parent
  Quaternion absDirection; //! absolute direvtion in the world ( from (0,0,1) )

  tList<PNode>* children; //! list of the children

};

#endif /* _P_NODE_H */