#ifndef __BEAM_H
#define __BEAM_H

#include <vector>
#include "AxisAlignedBox3.h"
#include "Statistics.h"


namespace GtpVisibilityPreprocessor {

class KdNode;
class Intersectable;
class Mesh;


// the values need for rss tree update computed already inside the glrendererbuffer
// not all of them need to be computed
class BeamSampleStatistics: public StatisticsBase
{
public:
	enum {COMPUTE_PVS_SIZE, COMPUTE_RAY_CONTRIBUTIONS, COMPUTE_PVS_ENTROPY};
	int flags;

	BeamSampleStatistics(): flags(COMPUTE_RAY_CONTRIBUTIONS) 
	{
		Reset();
	}
	
	float pvsSize;
	float rays;
	float rayContributions;
	float pvsEntropy;
	float rayLengthEntropy;
	float importance;
	
	float weightedRayContribution;

	void Reset() 
	{
		pvsSize = 0;
		rays = 0;
		rayContributions = 0;
		pvsEntropy = 0;
		rayLengthEntropy = 0;
		importance = 0;
	}

	void Print(std::ostream &app) const;

	friend std::ostream &operator<<(std::ostream &s, const BeamSampleStatistics &stat) 
	{
		stat.Print(s);
		return s;
	}  
};

  
class Beam {
  
public:			
  enum {STORE_KD_NODES=1, STORE_OBJECTS=2, STORE_VIEW_CELLS, VALID=8};
  int mFlags;
  
  // list of nodes intersected by the frustum
  vector<KdNode *> mKdNodes;
  // list of objects intersected by the frustum
  ObjectContainer mObjects;
  // view cells intersected by frustum
  ViewCellContainer mViewCells;

  // spatial box
  AxisAlignedBox3 mBox;
  // directional box (it is actually a 2D box - only x and y ranges are valid)
  // directional parametrization according to VssRay::GetDirParametrization
  AxisAlignedBox3 mDirBox;

  vector<Plane3> mPlanes;

  Mesh *mMesh;
    
  /** Constructs a beam from a spatial and a directional box.
  */
  void Construct(const AxisAlignedBox3 &box,
		 	     const AxisAlignedBox3 &dBox);
  
  /** Computes parameters for glFrustum.
  */
  void ComputePerspectiveFrustum(float &left, float &right,
								 float &bottom, float &top,
								 float &near, float &far,
								 const AxisAlignedBox3 &sceneBBox) const;

  /** Computes parameters for glOrtho.
  */
  void ComputeOrthoFrustum(float &left, float &right,
						   float &bottom, float &top,
						   float &near, float &far,
						   const AxisAlignedBox3 &sceneBBox) const;

  int ComputeIntersection(const AxisAlignedBox3 &box);

  Vector3 GetMainDirection() const;

  bool IsValid() { return mFlags & VALID; }
  bool SetValid() { return mFlags |= VALID; }

  Beam():mFlags(STORE_KD_NODES+STORE_OBJECTS), mKdNodes(0), mObjects(0), mViewCells(0), mMesh(NULL)
  {
  }

  ~Beam();

  /** Creates beam mesh bounded at zfar.
  */
  void CreateMesh(const float zfar);
};

}

#endif