#ifndef _ViewCellBsp_H__
#define _ViewCellBsp_H__

#include "Containers.h"

class ViewCell;
class Plane3;

namespace GtpVisibilityPreprocessor {
  
  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;
  
  protected:

	  /// parent of this node
	  BspInterior *mParent;
  };

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

  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:
	  /** Default constructor.
	  */
	  BspTree();
        
  protected:

	  /// Pointer to the root of the tree
	  BspNode *mRoot;
	  /// Pointer to the root cell of the viewspace */
	  ViewCell *mRootCell;


  };
  
}; // GtpVisibilityPreprocessor

#endif