/*
   orxonox - the future of 3D-vertical-scrollers

   Copyright (C) 2004 orx

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2, or (at your option)
   any later version.

   ### File Specific:
   main-programmer: Patrick Boenzli
   co-programmer: Benjamin Grauer
*/

#define DEBUG_SPECIAL_MODULE DEBUG_MODULE_PNODE

#include "p_node.h"

#include "util/loading/load_param.h"
#include "class_list.h"

#include <algorithm>
#include "compiler.h"
#include "debug.h"

#include "glincl.h"
#include "color.h"

#include "synchronizeable.h"

/**
 * @brief standard constructor
 * @param parent the Parent of this Node. __NULL__ if __No Parent__ requested, PNode::getNullParent(), if connected to NullParent directly (default)
 * @param nodeFlags all flags to set. THIS_WILL_OVERWRITE Default_Values.
 */
PNode::PNode (PNode* parent, long nodeFlags)
  : BaseObject(), Synchronizeable()
{
  this->setClassID(CL_PARENT_NODE, "PNode");

  this->bRelCoorChanged = true;
  this->bRelDirChanged = true;
  this->parent = NULL;
  this->parentMode = nodeFlags;
  this->bActive = true;

  // smooth-movers
  this->toCoordinate = NULL;
  this->toDirection = NULL;
  this->bias = 1.0;

  if (parent != NULL)
    parent->addChild(this);

  this->relCoordinate_handle = this->registerVarId( new SynchronizeableVector( &relCoordinate, &relCoordinate_write, "coordinate" ) );
  this->relDirection_handle = this->registerVarId( new SynchronizeableQuaternion( &relDirection, &relDirection_write, "direction" ) );
}

// NullParent Reference
PNode* PNode::nullParent = NULL;

/**
 * @brief standard deconstructor
 *
 * There are two general ways to delete a PNode
 * 1. delete instance;
 *   -> result
 *    delete this Node and all its children and children's children...
 *    (danger if you still need the children's instance somewhere else!!)
 *
 * 2. instance->removeNode(); delete instance;
 *   -> result:
 *    moves its children to the NullParent
 *    then deletes the Element.
 */
PNode::~PNode ()
{
  PRINTF(4)("delete %s::%s\n", this->getClassName(), this->getName());
  // remove the Node, delete it's children (if required).
  std::list<PNode*>::iterator deleteNode;
  unsigned int size;
  while(!this->children.empty())
  {
    deleteNode = this->children.begin();
    size = this->children.size();
    if ((this->parentMode & PNODE_PROHIBIT_CHILD_DELETE) ||
        ((*deleteNode)->parentMode & PNODE_PROHIBIT_DELETE_WITH_PARENT))
    {
      if (this == PNode::nullParent && (*deleteNode)->parentMode & PNODE_REPARENT_TO_NULL)
      {
        PRINTF(4)("%s::%s deletes %s::%s\n",
                  this->getClassName(), this->getName(),
                  (*deleteNode)->getClassName(), (*deleteNode)->getName());
        delete (*deleteNode);
      }
      else
      {
        PRINTF(4)("%s::%s reparents %s::%s\n",
                  this->getClassName(), this->getName(),
                  (*deleteNode)->getClassName(), (*deleteNode)->getName());
        (*deleteNode)->reparent();
      }
    }
    else
    {
      PRINTF(4)("%s::%s deletes PNode: %s::%s\n",
                this->getClassName(), this->getName(),
                (*deleteNode)->getClassName(), (*deleteNode)->getName());
      delete (*deleteNode);
    }
  }

  if (this->parent != NULL)
  {
    this->parent->eraseChild(this);
    this->parent = NULL;
  }

  // remove all other allocated memory.
  if (this->toCoordinate != NULL)
    delete this->toCoordinate;
  if (this->toDirection != NULL)
    delete this->toDirection;

  if (this == PNode::nullParent)
    PNode::nullParent = NULL;
}


/**
 * @brief loads parameters of the PNode
 * @param root the XML-element to load the properties of
 */
void PNode::loadParams(const TiXmlElement* root)
{
  BaseObject::loadParams(root);

  LoadParam(root, "rel-coor", this, PNode, setRelCoor)
  .describe("Sets The relative position of the Node to its parent.");

  LoadParam(root, "abs-coor", this, PNode, setAbsCoor)
  .describe("Sets The absolute Position of the Node.");

  LoadParam(root, "rel-dir", this, PNode, setRelDir)
  .describe("Sets The relative rotation of the Node to its parent.");

  LoadParam(root, "abs-dir", this, PNode, setAbsDir)
  .describe("Sets The absolute rotation of the Node.");

  LoadParam(root, "parent", this, PNode, setParent)
  .describe("the Name of the Parent to set for this PNode");

  LoadParam(root, "parent-mode", this, PNode, setParentMode)
  .describe("the mode to connect this node to its parent ()");

  // cycling properties
  if (root != NULL)
  {
    LOAD_PARAM_START_CYCLE(root, element);
    {
      LoadParam_CYCLE(element, "child", this, PNode, addChild)
      .describe("adds a new Child to the current Node.");

    }
    LOAD_PARAM_END_CYCLE(element);
  }
}


/**
 *  init the pnode to a well definied state
 *
 * this function actualy only updates the PNode tree
 */
void PNode::init()
{
  /* just update all aboslute positions via timestep 0.001ms */
  this->updateNode(0.001f);
  this->updateNode(0.001f);
}


/**
 * @brief set relative coordinates
 * @param relCoord relative coordinates to its parent
 *
 *
 * it is very importand, that you use this function, if you want to update the
 * relCoordinates. If you don't use this, the PNode won't recognize, that something
 * has changed and won't update the children Nodes.
 */
void PNode::setRelCoor (const Vector& relCoord)
{
  if (this->toCoordinate!= NULL)
  {
    delete this->toCoordinate;
    this->toCoordinate = NULL;
  }

  this->relCoordinate = relCoord;
  this->bRelCoorChanged = true;
}

/**
 * @brief set relative coordinates
 * @param x x-relative coordinates to its parent
 * @param y y-relative coordinates to its parent
 * @param z z-relative coordinates to its parent
 * @see  void PNode::setRelCoor (const Vector& relCoord)
 */
void PNode::setRelCoor (float x, float y, float z)
{
  this->setRelCoor(Vector(x, y, z));
}

/**
 * @brief sets a new relative position smoothely
 * @param relCoordSoft the new Position to iterate to
 * @param bias how fast to iterate to this position
 */
void PNode::setRelCoorSoft(const Vector& relCoordSoft, float bias)
{
  if (likely(this->toCoordinate == NULL))
    this->toCoordinate = new Vector();

  *this->toCoordinate = relCoordSoft;
  this->bias = bias;
}


/**
 * @brief set relative coordinates smoothely
 * @param x x-relative coordinates to its parent
 * @param y y-relative coordinates to its parent
 * @param z z-relative coordinates to its parent
 * @see  void PNode::setRelCoorSoft (const Vector&, float)
 */
void PNode::setRelCoorSoft (float x, float y, float z, float bias)
{
  this->setRelCoorSoft(Vector(x, y, z), bias);
}


/**
 * @param absCoord set absolute coordinate
 */
void PNode::setAbsCoor (const Vector& absCoord)
{
  if (this->toCoordinate!= NULL)
  {
    delete this->toCoordinate;
    this->toCoordinate = NULL;
  }

  if( likely(this->parentMode & PNODE_MOVEMENT))
  {
    /* if you have set the absolute coordinates this overrides all other changes */
    if (likely(this->parent != NULL))
      this->relCoordinate = absCoord - parent->getAbsCoor ();
    else
      this->relCoordinate = absCoord;
  }
  if( this->parentMode & PNODE_ROTATE_MOVEMENT)
  {
    if (likely(this->parent != NULL))
      this->relCoordinate = absCoord - parent->getAbsCoor ();
    else
      this->relCoordinate = absCoord;
  }

  this->bRelCoorChanged = true;
  //  this->absCoordinate = absCoord;
}


/**
 * @param x x-coordinate.
 * @param y y-coordinate.
 * @param z z-coordinate.
 * @see void PNode::setAbsCoor (const Vector& absCoord)
 */
void PNode::setAbsCoor(float x, float y, float z)
{
  this->setAbsCoor(Vector(x, y, z));
}


/**
 * @param absCoord set absolute coordinate
 * @todo check off
 */
void PNode::setAbsCoorSoft (const Vector& absCoordSoft, float bias)
{
  if (this->toCoordinate == NULL)
    this->toCoordinate = new Vector;

  if( likely(this->parentMode & PNODE_MOVEMENT))
  {
    /* if you have set the absolute coordinates this overrides all other changes */
    if (likely(this->parent != NULL))
      *this->toCoordinate = absCoordSoft - parent->getAbsCoor ();
    else
      *this->toCoordinate = absCoordSoft;
  }
  if( this->parentMode & PNODE_ROTATE_MOVEMENT)
  {
    if (likely(this->parent != NULL))
      *this->toCoordinate = absCoordSoft - parent->getAbsCoor ();
    else
      *this->toCoordinate = absCoordSoft;
  }
}


/**
 * @brief shift coordinate relative
 * @param shift shift vector
 *
 * this function shifts the current coordinates about the vector shift. this is
 * usefull because from some place else you can:
 * PNode* someNode = ...;
 * Vector objectMovement = calculateShift();
 * someNode->shiftCoor(objectMovement);
 *
 * this is the internal method of:
 * PNode* someNode = ...;
 * Vector objectMovement = calculateShift();
 * Vector currentCoor = someNode->getRelCoor();
 * Vector newCoor = currentCoor + objectMovement;
 * someNode->setRelCoor(newCoor);
 *
 */
void PNode::shiftCoor (const Vector& shift)
{
  this->relCoordinate += shift;
  this->bRelCoorChanged = true;
}


/**
 * @brief set relative direction
 * @param relDir to its parent
 */
void PNode::setRelDir (const Quaternion& relDir)
{
  if (this->toDirection!= NULL)
  {
    delete this->toDirection;
    this->toDirection = NULL;
  }
  this->relDirection = relDir;

  this->bRelCoorChanged = true;
}


/**
 * @see void PNode::setRelDir (const Quaternion& relDir)
 * @param x the x direction
 * @param y the y direction
 * @param z the z direction
 *
 * main difference is, that here you give a directional vector, that will be translated into a Quaternion
 */
void PNode::setRelDir (float angle, float x, float y, float z)
{
  this->setRelDir(Quaternion(angle, Vector(x,y,z)));
}


/**
 * @brief sets the Relative Direction of this node to its parent in a Smoothed way
 * @param relDirSoft the direction to iterate to smoothely.
 * @param bias how fast to iterate to the new Direction
 */
void PNode::setRelDirSoft(const Quaternion& relDirSoft, float bias)
{
  if (likely(this->toDirection == NULL))
    this->toDirection = new Quaternion();

  *this->toDirection = relDirSoft;
  this->bias = bias;
  this->bRelDirChanged = true;
}


/**
 * @see void PNode::setRelDirSoft (const Quaternion& relDir)
 * @param x the x direction
 * @param y the y direction
 * @param z the z direction
 *
 * main difference is, that here you give a directional vector, that will be translated into a Quaternion
 */
void PNode::setRelDirSoft(float angle, float x, float y, float z, float bias)
{
  this->setRelDirSoft(Quaternion(angle, Vector(x,y,z)), bias);
}


/**
 * @brief sets the absolute direction
 * @param absDir absolute coordinates
 */
void PNode::setAbsDir (const Quaternion& absDir)
{
  if (this->toDirection!= NULL)
  {
    delete this->toDirection;
    this->toDirection = NULL;
  }

  if (likely(this->parent != NULL))
    this->relDirection = absDir / this->parent->getAbsDir();
  else
    this->relDirection = absDir;

  this->bRelDirChanged = true;
}


/**
 * @see void PNode::setAbsDir (const Quaternion& relDir)
 * @param x the x direction
 * @param y the y direction
 * @param z the z direction
 *
 * main difference is, that here you give a directional vector, that will be translated into a Quaternion
 */
void PNode::setAbsDir (float angle, float x, float y, float z)
{
  this->setAbsDir(Quaternion(angle, Vector(x,y,z)));
}


/**
 * @brief sets the absolute direction
 * @param absDir absolute coordinates
 * @param bias how fast to iterator to the new Position
 */
void PNode::setAbsDirSoft (const Quaternion& absDirSoft, float bias)
{
  if (this->toDirection == NULL)
    this->toDirection = new Quaternion();

  if (likely(this->parent != NULL))
    *this->toDirection = absDirSoft / this->parent->getAbsDir();
  else
    *this->toDirection = absDirSoft;

  this->bias = bias;
  this->bRelDirChanged = true;
}


/**
 * @see void PNode::setAbsDir (const Quaternion& relDir)
 * @param x the x direction
 * @param y the y direction
 * @param z the z direction
 *
 * main difference is, that here you give a directional vector, that will be translated into a Quaternion
 */
void PNode::setAbsDirSoft (float angle, float x, float y, float z, float bias)
{
  this->setAbsDirSoft(Quaternion(angle, Vector(x,y,z)), bias);
}


/**
 * @brief shift Direction
 * @param shift the direction around which to shift.
 */
void PNode::shiftDir (const Quaternion& shift)
{
  this->relDirection = this->relDirection * shift;
  this->bRelDirChanged = true;
}


/**
 * @brief adds a child and makes this node to a parent
 * @param child child reference
 * use this to add a child to this node.
 */
void PNode::addChild (PNode* child)
{
  if( likely(child->parent != NULL))
    child->parent->eraseChild(child);
  if (this->checkIntegrity(child))
  {
    child->parent = this;
    if (unlikely(this != NULL))
      this->children.push_back(child);
    child->parentCoorChanged();

    //     if(this->getUniqueID() == NET_UID_UNASSIGNED)
    //     {
    //       PRINTF(1)("Adding to an UNASSIGNED PNode - looking for next assigned Node\n");
    //       PNode* node = this->seekNextAssignedPNode(this);
    //       if( node == NULL)
    //         PRINTF(1)("    Got NULL - Is this the NULLParent - uid %i\n", this->getUniqueID());
    //       else
    //         PRINTF(1)("    Found next assigned node: %i\n", node->getUniqueID());
    //     }
  }
  else
  {
    PRINTF(1)("Tried to reparent to own child '%s::%s' to '%s::%s'.\n",
              this->getClassName(), this->getName(), child->getClassName(), child->getName());
    child->parent = NULL;
    child->parentCoorChanged();
  }
}


PNode* PNode::seekNextAssignedPNode(PNode* node) const
{
  PNode* tmpNode = node->parent;
  printf("entering seek PNode loop for name: %s, uid: %i\n", node->getName(), node->getUniqueID());
  if(tmpNode)
    printf("  @node name: %s, uid: %d\n", tmpNode->getName(), tmpNode->getUniqueID());
  while( tmpNode != NULL && tmpNode->getUniqueID() == NET_UID_UNASSIGNED)
  {
    printf("  @node name: %s, uid: %d\n", tmpNode->getName(), tmpNode->getUniqueID());
    tmpNode = tmpNode->parent;
  }
  printf("leaving PNode loop\n\n");

  return tmpNode;
}


/**
 * @see PNode::addChild(PNode* child);
 * @param childName the name of the child to add to this PNode
 */
void PNode::addChild (const std::string& childName)
{
  PNode* childNode = dynamic_cast<PNode*>(ClassList::getObject(childName, CL_PARENT_NODE));
  //  PRINTF(0)("Adding the Child: %s to: %s\n", childName, this->getName());
  //  assert( childNode != NULL );
  if (childNode != NULL)
  {
    this->addChild(childNode);
  }
}


/**
 * @brief removes a child from the node
 * @param child the child to remove from this pNode.
 *
 * Children from pNode will not be lost, they are Reparented by the rules of the ParentMode
 */
void PNode::removeChild (PNode* child)
{
  if (child != NULL)
    child->removeNode();
}


/**
 * !! PRIVATE FUNCTION
 * @brief reparents a node (happens on Parents Node delete or remove and Flags are set.)
 */
void PNode::reparent()
{
  if (this->parentMode & PNODE_REPARENT_TO_NULL)
    this->setParent((PNode*)NULL);
  else if (this->parentMode & PNODE_REPARENT_TO_PARENTS_PARENT && this->parent != NULL)
    this->setParent(this->parent->getParent());
  else
    this->setParent(PNode::getNullParent());
}

/**
 * ereases child from the nodes children
 * @param chuld the child to remove
 */
void PNode::eraseChild(PNode* child)
{
  std::list<PNode*>::iterator childRemover = std::find(this->children.begin(), this->children.end(), child);
  if(childRemover != this->children.end())
    this->children.erase(childRemover);
}


/**
 * @brief remove this pnode from the tree and adds all following to NullParent
 *
 * this can be the case, if an entity in the world is being destroyed.
 */
void PNode::removeNode()
{
  std::list<PNode*>::iterator child = this->children.begin();
  std::list<PNode*>::iterator reparenter;
  while (child != this->children.end())
  {
    reparenter = child;
    child++;
    if (this->parentMode & PNODE_REPARENT_CHILDREN_ON_REMOVE ||
        (*reparenter)->parentMode & PNODE_REPARENT_ON_PARENTS_REMOVE)
    {
      printf("TEST----------------%s ---- %s\n", this->getClassName(), (*reparenter)->getClassName());
      (*reparenter)->reparent();
      printf("REPARENTED TO: %s::%s\n",(*reparenter)->getParent()->getClassName(),(*reparenter)->getParent()->getName());
    }
  }
  if (this->parent != NULL)
  {
    this->parent->eraseChild(this);
    this->parent = NULL;
  }
}


/**
 * @see PNode::setParent(PNode* parent);
 * @param parentName the name of the Parent to set to this PNode
 */
void PNode::setParent (const std::string& parentName)
{
  PNode* parentNode = dynamic_cast<PNode*>(ClassList::getObject(parentName, CL_PARENT_NODE));
  if (parentNode != NULL)
    parentNode->addChild(this);
  else
    PRINTF(2)("Not Found PNode's (%s::%s) new Parent by Name: %s\n",
        this->getClassName(), this->getName(), parentName.c_str());
}


/**
 * @brief does the reparenting in a very smooth way
 * @param parentNode the new Node to connect this node to.
 * @param bias the speed to iterate to this new Positions
 */
void PNode::setParentSoft(PNode* parentNode, float bias)
{
  // return if the new parent and the old one match
  if (this->parent == parentNode )
    return;
  if (parentNode == NULL)
    parentNode = PNode::getNullParent();

  // store the Valures to iterate to.
  if (likely(this->toCoordinate == NULL))
  {
    this->toCoordinate = new Vector();
    *this->toCoordinate = this->getRelCoor();
  }
  if (likely(this->toDirection == NULL))
  {
    this->toDirection = new Quaternion();
    *this->toDirection = this->getRelDir();
  }
  this->bias = bias;

  Vector tmpV = this->getAbsCoor();
  Quaternion tmpQ = this->getAbsDir();

  parentNode->addChild(this);

  if (this->parentMode & PNODE_ROTATE_MOVEMENT && this->parent != NULL)
    this->relCoordinate = this->parent->getAbsDir().inverse().apply(tmpV - this->parent->getAbsCoor());
  else
    this->relCoordinate = tmpV - parentNode->getAbsCoor();

  this->relDirection = tmpQ / parentNode->getAbsDir();
}


/**
 * @brief does the reparenting in a very smooth way
 * @param parentName the name of the Parent to reconnect to
 * @param bias the speed to iterate to this new Positions
 */
void PNode::setParentSoft(const std::string& parentName, float bias)
{
  PNode* parentNode = dynamic_cast<PNode*>(ClassList::getObject(parentName, CL_PARENT_NODE));
  if (parentNode != NULL)
    this->setParentSoft(parentNode, bias);
}

/**
 * @param parentMode sets the parentingMode of this Node
 */
void PNode::setParentMode(PARENT_MODE parentMode)
{
  this->parentMode = ((this->parentMode & 0xfff0) | parentMode);
}

/**
 * @brief sets the mode of this parent manually
 * @param parentMode a String representing this parentingMode
 */
void PNode::setParentMode (const std::string& parentingMode)
{
  this->setParentMode(PNode::stringToParentingMode(parentingMode));
}

/**
 * @brief adds special mode Flags to this PNode
 * @see PARENT_MODE
 * @param nodeFlags a compsition of PARENT_MODE-flags, split by the '|' (or) operator.
 */
void PNode::addNodeFlags(unsigned short nodeFlags)
{
  this->parentMode |= nodeFlags;
}

/**
 * @brief removes special mode Flags to this PNode
 * @see PARENT_MODE
 * @param nodeFlags a compsition of PARENT_MODE-flags, split by the '|' (or) operator.
 */
void PNode::removeNodeFlags(unsigned short nodeFlags)
{
  this->parentMode &= !nodeFlags;
}

/**
 * @returns the NullParent (and if needed creates it)
 */
PNode* PNode::createNullParent()
{
  if (likely(PNode::nullParent == NULL))
  {
    PNode::nullParent = new PNode(NULL, PNODE_PARENT_MODE_DEFAULT | PNODE_REPARENT_TO_NULL);
    PNode::nullParent->setClassID(CL_NULL_PARENT, "NullParent");
    PNode::nullParent->setName("NullParent");
    PNode::nullParent->setSynchronized(true);
  }
  return PNode::nullParent;
}


/**
 * !! PRIVATE FUNCTION
 * @brief checks the upward integrity (e.g if PNode is somewhere up the Node tree.)
 * @param checkParent the Parent to check.
 * @returns true if the integrity-check succeeds, false otherwise.
 *
 * If there is a second occurence of checkParent before NULL, then a loop could get
 * into the Tree, and we do not want this.
 */
bool PNode::checkIntegrity(const PNode* checkParent) const
{
  const PNode* parent = this;
  while ( (parent = parent->getParent()) != NULL)
    if (unlikely(parent == checkParent))
      return false;
  return true;
}


/**
 * @brief updates the absCoordinate/absDirection
 * @param dt The time passed since the last update
 *
 * this is used to go through the parent-tree to update all the absolute coordinates
 * and directions. this update should be done by the engine, so you don't have to
 * worry, normaly...
 */
void PNode::updateNode (float dt)
{
  if (!(this->parentMode & PNODE_STATIC_NODE))
  {
    if( likely(this->parent != NULL))
    {
      // movement for nodes with smoothMove enabled
      if (unlikely(this->toCoordinate != NULL))
      {
        float shiftLen = fabsf(dt)*bias;
        if (unlikely(shiftLen >= 1.0))
          shiftLen = 1.0;
        Vector moveVect = (*this->toCoordinate - this->relCoordinate) * shiftLen;
        if (likely(moveVect.len() >= PNODE_ITERATION_DELTA))
        {
          this->shiftCoor(moveVect);
        }
        else
        {
          delete this->toCoordinate;
          this->toCoordinate = NULL;
          PRINTF(5)("SmoothMove of %s finished\n", this->getName());
        }
      }
      if (unlikely(this->toDirection != NULL))
      {
        float shiftLen = fabsf(dt)*bias;
        if (unlikely (shiftLen >= 1.0))
          shiftLen = 1.0;
        //printf("%s::%s %f\n", this->getClassName(), this->getName(), this->toStep );
        Quaternion rotQuat = Quaternion::quatSlerp(this->relDirection,*this->toDirection, shiftLen);
        if (this->relDirection.distance(rotQuat) > PNODE_ITERATION_DELTA)
        {
          this->relDirection = rotQuat;
          this->bRelDirChanged = true;
        }
        else
        {
          delete this->toDirection;
          this->toDirection = NULL;
          PRINTF(5)("SmoothRotate of %s finished\n", this->getName());
          this->bRelDirChanged = true;
        }
      }

      // MAIN UPDATE /////////////////////////////////////
      this->lastAbsCoordinate = this->absCoordinate;

      PRINTF(5)("PNode::update - '%s::%s' - (%f, %f, %f)\n", this->getClassName(), this->getName(),
                this->absCoordinate.x, this->absCoordinate.y, this->absCoordinate.z);


      if(this->bRelDirChanged && this->parentMode & PNODE_LOCAL_ROTATE )
      {
        /* update the current absDirection - remember * means rotation around sth.*/
        this->prevRelCoordinate = this->relCoordinate;
        this->absDirection = parent->getAbsDir() * this->relDirection;
      }

      if(likely(this->bRelCoorChanged && this->parentMode & PNODE_MOVEMENT))
      {
        /* update the current absCoordinate */
        this->prevRelCoordinate = this->relCoordinate;
        this->absCoordinate = this->parent->getAbsCoor() + this->relCoordinate;
      }
      else if( this->parentMode & PNODE_ROTATE_MOVEMENT && (this->bRelCoorChanged || this->bRelDirChanged))
      {
        /* update the current absCoordinate */
        this->prevRelCoordinate = this->relCoordinate;
        this->absCoordinate = this->parent->getAbsCoor() + parent->getAbsDir().apply(this->relCoordinate);
      }
      /////////////////////////////////////////////////
    }

    else // Nodes without a Parent are handled faster :: MOST LIKELY THE NULLPARENT
    {
      PRINTF(4)("update ParentLess Node (%s::%s) - (%f, %f, %f)\n", this->getClassName(), this->getName(),
                this->absCoordinate.x, this->absCoordinate.y, this->absCoordinate.z);
      if (this->bRelCoorChanged)
      {
        this->prevRelCoordinate = this->relCoordinate;
        this->absCoordinate = this->relCoordinate;
      }
      if (this->bRelDirChanged)
      {
        this->prevRelDirection = this->relDirection;
        this->absDirection = this->getAbsDir () * this->relDirection;
      }
    }
  }

  if(!this->children.empty() && (this->bActive || this->parentMode & PNODE_UPDATE_CHILDREN_IF_INACTIVE ))
  {
    std::list<PNode*>::iterator child;
    for (child = this->children.begin(); child != this->children.end(); child ++)
    {
      /* if this node has changed, make sure, that all children are updated also */
      if( likely(this->bRelCoorChanged))
        (*child)->parentCoorChanged ();
      if( likely(this->bRelDirChanged))
        (*child)->parentDirChanged ();

      (*child)->updateNode(dt);
    }
  }
  this->velocity = (this->absCoordinate - this->lastAbsCoordinate) / dt;
  this->bRelCoorChanged = false;
  this->bRelDirChanged = false;
}





/*************
 * DEBUGGING *
 *************/
/**
 * @brief counts total amount the children walking through the entire tree.
 * @param nodes the counter
 */
void PNode::countChildNodes(int& nodes) const
{
  nodes++;
  std::list<PNode*>::const_iterator child;
  for (child = this->children.begin(); child != this->children.end(); child ++)
    (*child)->countChildNodes(nodes);
}


/**
 * @brief displays some information about this pNode
 * @param depth The deph into which to debug the children of this PNode to.
 * (0: all children will be debugged, 1: only this PNode, 2: this and direct children, ...)
 * @param level !! INTERNAL !! The n-th level of the Node we draw (this is internal and only for nice output).
 */
void PNode::debugNode(unsigned int depth, unsigned int level) const
{
  for (unsigned int i = 0; i < level; i++)
    PRINT(0)(" |");
  if (this->children.size() > 0)
    PRINT(0)(" +");
  else
    PRINT(0)(" -");

  int childNodeCount = 0;
  this->countChildNodes(childNodeCount);

  PRINT(0)("PNode(%s::%s) - absCoord: (%0.2f, %0.2f, %0.2f), relCoord(%0.2f, %0.2f, %0.2f), direction(%0.2f, %0.2f, %0.2f) - %s - %d childs\n",
           this->getClassName(),
           this->getName(),
           this->absCoordinate.x,
           this->absCoordinate.y,
           this->absCoordinate.z,
           this->relCoordinate.x,
           this->relCoordinate.y,
           this->relCoordinate.z,
           this->getAbsDirV().x,
           this->getAbsDirV().y,
           this->getAbsDirV().z,
           this->parentingModeToString(parentMode),
           childNodeCount);
  if (depth >= 2 || depth == 0)
  {
    std::list<PNode*>::const_iterator child;
    for (child = this->children.begin(); child != this->children.end(); child ++)
    {
      if (depth == 0)
        (*child)->debugNode(0, level + 1);
      else
        (*child)->debugNode(depth - 1, level +1);
    }
  }
}

/**
 * @brief displays the PNode at its position with its rotation as a cube.
 * @param  depth The deph into which to debug the children of this PNode to.
 * (0: all children will be displayed, 1: only this PNode, 2: this and direct children, ...)
 * @param size the Size of the Box to draw.
 * @param color the color of the Box to display.
 * @param level !! INTERNAL !! The n-th level of the Node we draw (this is internal and only for nice output).
 */
void PNode::debugDraw(unsigned int depth, float size, const Vector& color, unsigned int level) const
{
  // if this is the first Element we draw
  if (level == 0)
  {
    glPushAttrib(GL_ENABLE_BIT); // save the Enable-attributes
    glMatrixMode(GL_MODELVIEW);  // goto the ModelView Matrix

    glDisable(GL_LIGHTING);      // disable lighting (we do not need them for just lighting)
    glDisable(GL_BLEND);         // ''
    glDisable(GL_TEXTURE_2D);    // ''
    glDisable(GL_DEPTH_TEST);    // ''
  }

  glPushMatrix();                // repush the Matrix-stack
  /* translate */
  glTranslatef (this->getAbsCoor ().x,
                this->getAbsCoor ().y,
                this->getAbsCoor ().z);
  //  this->getAbsDir ().matrix (matrix);

  /* rotate */
  Vector tmpRot = this->getAbsDir().getSpacialAxis();
  glRotatef (this->getAbsDir().getSpacialAxisAngle(), tmpRot.x, tmpRot.y, tmpRot.z );
  /* set the new Color */
  glColor3f(color.x, color.y, color.z);
  { /* draw a cube of size size */
    glBegin(GL_LINE_STRIP);
    glVertex3f(-.5*size, -.5*size,  -.5*size);
    glVertex3f(+.5*size, -.5*size,  -.5*size);
    glVertex3f(+.5*size, -.5*size,  +.5*size);
    glVertex3f(-.5*size, -.5*size,  +.5*size);
    glVertex3f(-.5*size, -.5*size,  -.5*size);
    glEnd();
    glBegin(GL_LINE_STRIP);
    glVertex3f(-.5*size, +.5*size,  -.5*size);
    glVertex3f(+.5*size, +.5*size,  -.5*size);
    glVertex3f(+.5*size, +.5*size,  +.5*size);
    glVertex3f(-.5*size, +.5*size,  +.5*size);
    glVertex3f(-.5*size, +.5*size,  -.5*size);
    glEnd();

    glBegin(GL_LINES);
    glVertex3f(-.5*size, -.5*size,  -.5*size);
    glVertex3f(-.5*size, +.5*size,  -.5*size);
    glVertex3f(+.5*size, -.5*size,  -.5*size);
    glVertex3f(+.5*size, +.5*size,  -.5*size);
    glVertex3f(+.5*size, -.5*size,  +.5*size);
    glVertex3f(+.5*size, +.5*size,  +.5*size);
    glVertex3f(-.5*size, -.5*size,  +.5*size);
    glVertex3f(-.5*size, +.5*size,  +.5*size);
    glEnd();
  }
  glPopMatrix();

  if (depth >= 2 || depth == 0)
  {
    /* rotate the current color in HSV space around 20 degree */
    Vector childColor =  Color::HSVtoRGB(Color::RGBtoHSV(color)+Vector(20,0,.0));
    std::list<PNode*>::const_iterator child;
    for (child = this->children.begin(); child != this->children.end(); child ++)
    {
      // drawing the Dependency graph
      if (this != PNode::getNullParent())
      {
        glBegin(GL_LINES);
        glColor3f(color.x, color.y, color.z);
        glVertex3f(this->getAbsCoor ().x,
                   this->getAbsCoor ().y,
                   this->getAbsCoor ().z);
        glColor3f(childColor.x, childColor.y, childColor.z);
        glVertex3f((*child)->getAbsCoor ().x,
                   (*child)->getAbsCoor ().y,
                   (*child)->getAbsCoor ().z);
        glEnd();
      }

      /* if we want to draw the children too */
      if (depth == 0) /* -> all of them */
        (*child)->debugDraw(0, size, childColor, level+1);
      else            /* -> only the Next one */
        (*child)->debugDraw(depth - 1, size, childColor, level +1);
    }
  }
  if (level == 0)
    glPopAttrib(); /* pop the saved attributes back out */
}



/////////////////////
// HELPER_FUCTIONS //
/////////////////////

/**
 * @brief converts a parentingMode into a string that is the name of it
 * @param parentingMode the ParentingMode to convert
 * @return the converted string
 */
const char* PNode::parentingModeToString(int parentingMode)
{
  if (parentingMode == PNODE_LOCAL_ROTATE)
    return "local-rotate";
  else if (parentingMode == PNODE_ROTATE_MOVEMENT)
    return "rotate-movement";
  else if (parentingMode == PNODE_MOVEMENT)
    return "movement";
  else if (parentingMode == PNODE_ALL)
    return "all";
  else if (parentingMode == PNODE_ROTATE_AND_MOVE)
    return "rotate-and-move";
  else
    return "all";
}

/**
 * @brief converts a parenting-mode-string into a int
 * @param parentingMode the string naming the parentingMode
 * @return the int corresponding to the named parentingMode
 */
PARENT_MODE PNode::stringToParentingMode(const std::string& parentingMode)
{
  if (parentingMode == "local-rotate")
    return (PNODE_LOCAL_ROTATE);
  else  if (parentingMode == "rotate-movement")
    return (PNODE_ROTATE_MOVEMENT);
  else  if (parentingMode == "movement")
    return (PNODE_MOVEMENT);
  else  if (parentingMode == "all")
    return (PNODE_ALL);
  else  if (parentingMode == "rotate-and-move")
    return (PNODE_ROTATE_AND_MOVE);
  else
    return PNODE_ALL;
}

/**
 * handles changes in synchronizable variables
 * @param id id's which changed
 */
void PNode::varChangeHandler( std::list< int > & id )
{
  Synchronizeable::varChangeHandler( id );
  
  if ( std::find( id.begin(), id.end(), relCoordinate_handle ) != id.end() )
  {
    setRelCoor( relCoordinate_write );
  }

  if ( std::find( id.begin(), id.end(), relDirection_handle ) != id.end() )
  {
    setRelDir( relDirection_write );
  }
}