#ifndef _ViewCellBsp_H__
#define _ViewCellBsp_H__

#include "Plane3.h"


class BSPInterior;

/**
     BSPNode abstract class serving for interior and leaf node implementation
  */
class BSPNode {
public:
  /** Determines whether this node is a leaf or not
      @return true if leaf
  */
  virtual bool IsLeaf() const = 0;
    
  /** Determines whether this node is a root
      @return true if root
  */
  virtual bool IsRoot() const {
    return parent == NULL;
  }
protected:
  /// parent of this node
  BSPInterior *parent;
};

/** BSP interior node implementation */
class BSPInterior : public BSPNode {
    
  /** @return false since it is an interior node */
  virtual bool IsLeaf() const { return false; }

protected:
  /// Splitting plane corresponding to this node
  Plane3 mPlane;
  /// back node
  BSPNode *mBack;
  /// front node
  BSPNode *mFront;
};
  
  
/** BSP leaf node implementation */
class BSPLeaf : public BSPNode {
public:
  BSPLeaf(ViewCell *viewCell = NULL):mViewCell(viewCell) {}
  /** @return true since it is an interior node */
  virtual bool IsLeaf() const { return true; }

protected:
  /// polygonal representation of this viewcell
  /// if NULL this note does not correspond to feasible viewcell
  ViewCell *mViewCell;
};
  
/** Implementation of the ViewCell BSP tree */
class BSPTree {
public:
  /** Constructor takes a pointer to the cell corresponding to the whole
      viewspace */
  BSPTree(ViewCell *cell) {
    mRootCell = cell;
    mRoot = new BSPLeaf(mRootCell);
  }
    
    
protected:
  /// Pointer to the root of the tree
  BSPNode *mRoot;
  /// Pointer to the root cell of the viewspace */
  ViewCell *mRootCell;
};
  



#endif