#ifndef _ViewCell_H__
#define _ViewCell_H__

#include "Mesh.h"
#include "Containers.h"
#include "Ray.h"
#include "Statistics.h"
//namespace GtpVisibilityPreprocessor {

struct Triangle3;

class BspInterior;
class BspPvs;
class BspLeaf;
class VspKdTree;
class VspKdLeaf;
class KdLeaf;

/** Statistics for a view cell partition.
*/

class ViewCellsStatistics: public StatisticsBase
{
public:

	/// number of view cells
	int viewCells;

	/// size of the PVS
	int pvs;

	/// largest PVS of all view cells
	int maxPvs;

	/// smallest PVS of all view cells
	int minPvs;

	/// view cells with empty PVS
	int emptyPvs;

	/// number of leaves covering the view space
	int leaves;

	/// largest number of leaves covered by one view cell
	int maxLeaves;

    // Constructor
	ViewCellsStatistics()
	{
		Reset();
	}

	double AvgLeaves() const {return (double)leaves / (double)viewCells;};
	double AvgPvs() const {return (double)pvs / (double)viewCells;};

	void Reset()
	{
		viewCells = 0;
		pvs = 0;
		maxPvs = 0;

		minPvs = 999999;
		emptyPvs = 0;
		leaves = 0;
		maxLeaves = 0;
	}

	void Print(ostream &app) const;

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

/**
	View cell with an optional mesh representation
*/
class ViewCell: public MeshInstance
{
public:
	ViewCell();

	/** Constructor taking a mesh representing the shape of	the viewcell.
	*/
	ViewCell(Mesh *mesh);

	/** Default destructor.
	*/
	virtual ~ViewCell() {}
	/** Returns Pvs.
	*/
	const ObjectPvs &GetPvs() const;
	ObjectPvs &GetPvs();

	int Type() const;

	/** Adds a passing ray to the passing ray container.
	*/
	void AddPassingRay(const Ray &ray, const int contributions);

	/** Returns volume of the view cell.
	*/
	float GetVolume() const;

	/** Returns area of the view cell.
	*/
	float GetArea() const;

	/** Sets the volume of the view cell.
	*/
	void SetVolume(float volume);
	
	/** Sets the area of the view cell.
	*/
	void SetArea(float area);
	virtual void UpdateViewCellsStats(ViewCellsStatistics &vcStat);

	/// Ray set description of the rays passing through this node.
	PassingRaySet mPassingRays;

	/// Rays piercing this view cell.
	RayContainer mPiercingRays;

protected:

	/// the potentially visible objects
	ObjectPvs mPvs;

	float mVolume;
	float mArea;
};

/**
	View cell belonging to a hierarchy.
*/
template<typename T>
class HierarchyViewCell: public ViewCell
{
public:
	HierarchyViewCell<T>(): mLeaves(0) {}
	HierarchyViewCell<T>(Mesh *mesh):
		ViewCell(mesh), mLeaves(0) {}

	void UpdateViewCellsStats(ViewCellsStatistics &vcStat)
	{
		ViewCell::UpdateViewCellsStats(vcStat);

		if ((int)mLeaves.size() > vcStat.maxLeaves)
			vcStat.maxLeaves = (int)mLeaves.size();
	}

	/// Leaves of the hierarchy which are part of this view cell.
	std::vector<T> mLeaves;
};


typedef HierarchyViewCell<BspLeaf *> BspViewCell;
typedef HierarchyViewCell<KdLeaf *> KdViewCell;
typedef HierarchyViewCell<VspKdLeaf *> VspKdViewCell;


#endif