#include "Environment.h"
#include "GvsPreprocessor.h"
#include "GlRenderer.h"
#include "VssRay.h"
#include "ViewCellsManager.h"
#include "Triangle3.h"
#include "IntersectableWrapper.h"
#include "Plane3.h"
#include "RayCaster.h"
#include "Exporter.h"
#include "SamplingStrategy.h"
#include "BvHierarchy.h"
#include "Polygon3.h"
#include "IntersectableWrapper.h"
#include "Timer/PerfTimer.h"
#include "Vector2.h"
#include "RndGauss.h"



namespace GtpVisibilityPreprocessor
{
  
#define GVS_DEBUG 0
#define NOT_ACCOUNTED_OBJECT 0
#define ACCOUNTED_OBJECT 2
#define DETERMINISTIC_GVS 0

static const float MIN_DIST = 0.001f;

static ObjectContainer myobjects;
static int sInvalidSamples = 0;

///////////
//-- timers


static PerfTimer rayTimer;
static PerfTimer kdPvsTimer;
static PerfTimer gvsTimer;
static PerfTimer initialTimer;
static PerfTimer intersectionTimer;
static PerfTimer preparationTimer;
static PerfTimer mainLoopTimer;
static PerfTimer contributionTimer;
static PerfTimer castTimer;
static PerfTimer generationTimer;


/////////////////////


/** Visualization structure for the GVS algorithm.
*/
struct VizStruct
{
	Polygon3 *enlargedTriangle;
	Triangle3 originalTriangle;
	VssRay *ray;
};

static vector<VizStruct> vizContainer;




GvsPreprocessor::GvsPreprocessor(): 
Preprocessor(), 
mProcessedViewCells(0),
mCurrentViewCell(NULL),
mCurrentViewPoint(Vector3(0.0f, 0.0f, 0.0f)),
mOnlyRandomSampling(false)
//mOnlyRandomSampling(true)
{
	Environment::GetSingleton()->GetIntValue("GvsPreprocessor.totalSamples", mTotalSamples);
	Environment::GetSingleton()->GetIntValue("GvsPreprocessor.initialSamples", mInitialSamples);
	Environment::GetSingleton()->GetIntValue("GvsPreprocessor.gvsSamplesPerPass", mGvsSamplesPerPass);
	Environment::GetSingleton()->GetIntValue("GvsPreprocessor.minContribution", mMinContribution);
	Environment::GetSingleton()->GetFloatValue("GvsPreprocessor.epsilon", mEps);
	Environment::GetSingleton()->GetFloatValue("GvsPreprocessor.threshold", mThreshold);	
	Environment::GetSingleton()->GetBoolValue("GvsPreprocessor.perViewCell", mPerViewCell);
	Environment::GetSingleton()->GetIntValue("GvsPreprocessor.maxViewCells", mMaxViewCells);

	Environment::GetSingleton()->GetBoolValue("Preprocessor.evaluatePixelError", mEvaluatePixelError);

	Environment::GetSingleton()->GetBoolValue("ViewCells.useKdPvs", mUseKdPvs);


	char gvsStatsLog[100];
	Environment::GetSingleton()->GetStringValue("GvsPreprocessor.stats", gvsStatsLog);
	mGvsStatsStream.open(gvsStatsLog);

	cout << "number of gvs samples per pass: " << mGvsSamplesPerPass << endl;
	cout << "number of samples per pass: " << mSamplesPerPass << endl;
	cout << "only random sampling: " << mOnlyRandomSampling << endl;

	Debug << "Gvs preprocessor options" << endl;
	Debug << "number of total samples: " << mTotalSamples << endl;
	Debug << "number of initial samples: " << mInitialSamples << endl;
	Debug << "threshold: " << mThreshold << endl;
	Debug << "epsilon: " << mEps << endl;
	Debug << "stats: " << gvsStatsLog << endl;
	Debug << "per view cell: " << mPerViewCell << endl;
	Debug << "max view cells: " << mMaxViewCells << endl;
	Debug << "min contribution: " << mMinContribution << endl;

	mDistribution = new ViewCellBasedDistribution(*this, NULL);

	mGvsStats.Reset();

	// hack: some generic statistical values that can be used
	// by an application using the preprocessor
	for (int i = 0; i < 2; ++ i)
		mGenericStats[i] = 0;
}


GvsPreprocessor::~GvsPreprocessor()
{
	delete mDistribution;
	ClearRayQueue();
}


void GvsPreprocessor::ClearRayQueue()
{
	// clean ray queue
	while (!mRayQueue.empty())
	{
		// handle next ray
		VssRay *ray = mRayQueue.top();
		mRayQueue.pop();

		// note: deletion of the ray is handled by ray pool
	}
}


ViewCell *GvsPreprocessor::NextViewCell()
{
	if (mProcessedViewCells == (int)mViewCells.size())
		return NULL; // no more view cells

	ViewCell *vc = mViewCells[mProcessedViewCells];

   if (!vc->GetMesh())
		mViewCellsManager->CreateMesh(vc);

	mGvsStats.mViewCellId = vc->GetId();

	Debug << "vc: " << vc->GetId() << endl;

	++ mProcessedViewCells;
    
	return vc;
}


int GvsPreprocessor::CheckDiscontinuity(const VssRay &currentRay,
										const Triangle3 &hitTriangle,
										const VssRay &oldRay)
{
	// the predicted hitpoint: we expect to hit the same mesh again
	Vector3 predictedHit = CalcPredictedHitPoint(currentRay, hitTriangle, oldRay);

	float predictedLen = Magnitude(predictedHit - currentRay.mOrigin);
	float len = Magnitude(currentRay.mTermination - currentRay.mOrigin);
	
	// distance large => this is likely to be a discontinuity
	if (!((predictedLen - len) > mThreshold))
	// q: rather use relative distance?
	//if ((predictedLen / len) > mThreshold)
		return 0;

	SimpleRay simpleRay;

	// apply reverse sampling to find the gap
	if (!ComputeReverseRay(currentRay, hitTriangle, oldRay, simpleRay))
		return 0;

	static VssRayContainer reverseRays;
	reverseRays.clear();

	if (DETERMINISTIC_GVS)
	{
		VssRay *reverseRay = 
			mRayCaster->CastRay(simpleRay, mViewCellsManager->GetViewSpaceBox(), !mPerViewCell);

		reverseRays.push_back(reverseRay);
	}
	else
	{
		if (0)
			CastRayBundle4(simpleRay, reverseRays, mViewCellsManager->GetViewSpaceBox());
		else
			CastRayBundle16(simpleRay, reverseRays);
	}

	mGvsStats.mReverseSamples += (int)reverseRays.size();

	EnqueueRays(reverseRays);

	return (int)reverseRays.size();
}


int GvsPreprocessor::CountObject(Intersectable *triObj)
{
	int numObjects = 0;

	if ((triObj->mCounter != (NOT_ACCOUNTED_OBJECT + 1)) && 
		(triObj->mCounter != (ACCOUNTED_OBJECT + 1)))
	{
		++ triObj->mCounter;
		++ numObjects;
	}

	mGenericStats[1] += numObjects;

	return numObjects;
}


void GvsPreprocessor::UpdateStatsForVisualization(KdIntersectable *kdInt)
{
	int numObj = 0;

	// count new objects in pvs due to kd node conversion	
	myobjects.clear();
	// also gather duplicates to avoid mailing
	mKdTree->CollectObjectsWithDublicates(kdInt->GetItem(), myobjects);

	ObjectContainer::const_iterator oit, oit_end = myobjects.end();

	for (oit = myobjects.begin(); oit != oit_end; ++ oit)
		numObj += CountObject(*oit);

	mViewCellsManager->UpdateStatsForViewCell(mCurrentViewCell, kdInt, numObj);
}	


void GvsPreprocessor::AddKdNodeToPvs(const Vector3 &termination)
{
	kdPvsTimer.Entry();

	// exchange the triangle with the node in the pvs for kd pvs
	KdNode *node = mKdTree->GetPvsNode(termination);

	//KdNode *node = mKdTree->GetPvsNodeCheck(ray.mTermination, obj);
	//if (!node) cerr << "e " << obj->GetBox() << " " << ray.mTermination << endl; else 
	if (!node->Mailed())
	{
		// add to pvs
		node->Mail();
		KdIntersectable *kdInt = mKdTree->GetOrCreateKdIntersectable(node);
		mCurrentViewCell->GetPvs().AddSampleDirty(kdInt, 1.0f);

		if (QT_VISUALIZATION_SHOWN) UpdateStatsForVisualization(kdInt);	
	}

	kdPvsTimer.Exit();
}


bool GvsPreprocessor::HasContribution(VssRay &ray)
{
	if (!ray.mTerminationObject)
		return false;

	contributionTimer.Entry();

	bool result;

	if (!mPerViewCell)
	{
		// store the rays + the intersected view cells
		const bool storeViewCells = false;

		mViewCellsManager->ComputeSampleContribution(ray, 
													 true, 
													 storeViewCells,
													 true);

		result = ray.mPvsContribution > 0;
	}
	else // original per view cell gvs
	{
		// test if triangle was accounted for yet
		result = AddTriangleObject(ray.mTerminationObject);
		
		if (mUseKdPvs)
			AddKdNodeToPvs(ray.mTermination);
	}

	contributionTimer.Exit();

	return result;
}


bool GvsPreprocessor::HandleRay(VssRay *vssRay)
{
	if (!vssRay || !HasContribution(*vssRay))
		return false;

	if (0 && GVS_DEBUG)
		mVssRays.push_back(new VssRay(*vssRay));

	// add new ray to ray queue
	mRayQueue.push(vssRay);

	++ mGvsStats.mTotalContribution;

	return true;
}


/** Creates 3 new vertices for triangle vertex with specified index.
*/
void GvsPreprocessor::CreateDisplacedVertices(VertexContainer &vertices,
											  const Triangle3 &hitTriangle,
											  const VssRay &ray, 
											  const int index) const
{
	const int indexU = (index + 1) % 3;
	const int indexL = (index == 0) ? 2 : index - 1;

	const Vector3 a = hitTriangle.mVertices[index] - ray.GetOrigin();
	const Vector3 b = hitTriangle.mVertices[indexU] - hitTriangle.mVertices[index];
	const Vector3 c = hitTriangle.mVertices[index] - hitTriangle.mVertices[indexL];
	
	const float len = Magnitude(a);
	
	const Vector3 dir1 = Normalize(CrossProd(a, b)); //N((pi-xp)×(pi+1- pi));
	const Vector3 dir2 = Normalize(CrossProd(a, c)); // N((pi-xp)×(pi- pi-1))
	const Vector3 dir3 = DotProd(dir2, dir1) > 0 ? // N((pi-xp)×di,i-1+di,i+1×(pi-xp))
		Normalize(dir2 + dir1) : Normalize(CrossProd(a, dir1) + CrossProd(dir2, a)); 

	// compute the new three hit points
	// pi, i + 1:  pi+ e·|pi-xp|·di, j
	const Vector3 pt1 = hitTriangle.mVertices[index] + mEps * len * dir1;
	// pi, i - 1:  pi+ e·|pi-xp|·di, j
    const Vector3 pt2 = hitTriangle.mVertices[index] + mEps * len * dir2;
	// pi, i:  pi+ e·|pi-xp|·di, j
	const Vector3 pt3 = hitTriangle.mVertices[index] + mEps * len * dir3;
	
	vertices.push_back(pt2);
	vertices.push_back(pt3);
	vertices.push_back(pt1);
}


void GvsPreprocessor::EnlargeTriangle(VertexContainer &vertices,
									  const Triangle3 &hitTriangle,
									  const VssRay &ray) const
{
	CreateDisplacedVertices(vertices, hitTriangle, ray, 0);
	CreateDisplacedVertices(vertices, hitTriangle, ray, 1);
	CreateDisplacedVertices(vertices, hitTriangle, ray, 2);
}


Vector3 GvsPreprocessor::CalcPredictedHitPoint(const VssRay &newRay, 
											   const Triangle3 &hitTriangle,
											   const VssRay &oldRay) const
{
	// find the intersection of the plane induced by the 
	// hit triangle with the new ray
	Plane3 plane(hitTriangle.GetNormal(), hitTriangle.mVertices[0]);

	const Vector3 hitPt = 
		plane.FindIntersection(newRay.mTermination, newRay.mOrigin);
	
	return hitPt;
}


static bool EqualVisibility(const VssRay &a, const VssRay &b)
{
	return a.mTerminationObject == b.mTerminationObject;
}


int GvsPreprocessor::SubdivideEdge(const Triangle3 &hitTriangle,
								   const Vector3 &p1, 
								   const Vector3 &p2, 
								   const VssRay &ray1, 
								   const VssRay &ray2,
								   const VssRay &oldRay)
{
	//cout <<"y"<<Magnitude(p1 - p2) << " ";
	int castRays = 0;

	// cast reverse rays if necessary
	castRays += CheckDiscontinuity(ray1, hitTriangle, oldRay);
	castRays += CheckDiscontinuity(ray2, hitTriangle, oldRay);

	if (EqualVisibility(ray1, ray2) || (SqrMagnitude(p1 - p2) <= MIN_DIST))
	{
		return castRays;
	}
	
	// the new subdivision point
	const Vector3 p = (p1 + p2) * 0.5f;
	//cout << "p: " << p << " " << p1 << " " << p2 << endl;

	SimpleRay sray(oldRay.mOrigin, p - oldRay.mOrigin, SamplingStrategy::GVS, 1.0f);

	VssRay *newRay;

	// cast single ray
	castTimer.Entry();

	// cast single ray to check if a triangle was missed. note: not efficient!!
	newRay = mRayCaster->CastRay(sray, mViewCellsManager->GetViewSpaceBox(), !mPerViewCell);
	castTimer.Exit();

	++ castRays;

	// this ray will not be further processed
	// note: ray deletion is handled by ray pool
	if (!newRay) return castRays;

	rayTimer.Entry();

	// new triangle discovered? => add new ray to queue
	HandleRay(newRay);

	rayTimer.Exit();
	
	//newRay->mFlags |= VssRay::BorderSample;

	// subdivide further
	castRays += SubdivideEdge(hitTriangle, p1, p, ray1, *newRay, oldRay);
	castRays += SubdivideEdge(hitTriangle, p, p2, *newRay, ray2, oldRay);
	
	return castRays;
}


int GvsPreprocessor::AdaptiveBorderSampling(const VssRay &currentRay)
{
	Intersectable *tObj = currentRay.mTerminationObject;

	// question matt: can this be possible?
	if (!tObj) return 0;

	Triangle3 hitTriangle;

	// other types not implemented yet
	if (tObj->Type() == Intersectable::TRIANGLE_INTERSECTABLE)
		hitTriangle = static_cast<TriangleIntersectable *>(tObj)->GetItem();
	else
		cout << "border sampling: " << Intersectable::GetTypeName(tObj) << " not yet implemented" << endl;

	//cout << "type: " << Intersectable::GetTypeName(tObj) << endl;
	generationTimer.Entry();

	static VertexContainer enlargedTriangle;
	enlargedTriangle.clear();

	/// create 3 new hit points for each vertex
	EnlargeTriangle(enlargedTriangle, hitTriangle, currentRay);
	
	/// create rays from sample points and handle them
	static SimpleRayContainer simpleRays;
	simpleRays.clear();

	VertexContainer::const_iterator vit, vit_end = enlargedTriangle.end();

	for (vit = enlargedTriangle.begin(); vit != vit_end; ++ vit)
	{
		const Vector3 rayDir = (*vit) - currentRay.GetOrigin();

		SimpleRay sr(currentRay.GetOrigin(), rayDir, SamplingStrategy::GVS, 1.0f);
		simpleRays.AddRay(sr);	
	}

	if (0)
	{
		// visualize enlarged triangles
		VizStruct dummy;
		dummy.enlargedTriangle = new Polygon3(enlargedTriangle);
		dummy.originalTriangle = hitTriangle;
		vizContainer.push_back(dummy);
	}

	
	//////////
	//-- fill up simple rays with random rays so we can cast 16 rays at a time

	const int numRandomRays = 16 - (int)simpleRays.size();

	if (!DETERMINISTIC_GVS)
	{
		if (0)
		{
			SimpleRay mainRay = SimpleRay(currentRay.GetOrigin(), 
				                          currentRay.GetNormalizedDir(), 
										  SamplingStrategy::GVS, 
										  1.0f);
			
			GenerateJitteredRays(simpleRays, mainRay, numRandomRays, 0);
		}
		else
			GenerateImportanceSamples(currentRay, hitTriangle, numRandomRays, simpleRays);
	}
	else
		GenerateRays(numRandomRays, *mDistribution, simpleRays, sInvalidSamples);

	generationTimer.Exit();

	/////////////////////
	//-- cast rays to vertices and determine visibility
	
	static VssRayContainer vssRays;
	vssRays.clear();

	// for the original implementation we don't cast double rays
	const bool castDoubleRays = !mPerViewCell;
	// cannot prune invalid rays because we have to compare adjacent rays
	const bool pruneInvalidRays = false;

	//gvsTimer.Entry();
	castTimer.Entry();

	CastRays(simpleRays, vssRays, castDoubleRays, pruneInvalidRays);
	
	castTimer.Exit();
	//gvsTimer.Exit();

	const int numBorderSamples = (int)vssRays.size() - numRandomRays;
	int castRays = (int)simpleRays.size();

	// handle cast rays
	EnqueueRays(vssRays);

	if (0)
	{
		// set flags
		VssRayContainer::const_iterator rit, rit_end = vssRays.end();
	
		for (rit = vssRays.begin(); rit != rit_end; ++ rit)
			(*rit)->mFlags |= VssRay::BorderSample;
	}

    // recursivly subdivide each edge
	for (int i = 0; i < numBorderSamples; ++ i)
	{
		castRays += SubdivideEdge(hitTriangle,
								  enlargedTriangle[i], 
								  enlargedTriangle[(i + 1) % numBorderSamples], 
								  *vssRays[i], 
								  *vssRays[(i + 1) % numBorderSamples],
								  currentRay);
	}
	
	mGvsStats.mBorderSamples += castRays;
	
	return castRays;
}


int GvsPreprocessor::AdaptiveBorderSamplingOpt(const VssRay &currentRay)
{
	Intersectable *tObj = currentRay.mTerminationObject;

	// question matt: can this be possible?
	if (!tObj) return 0;

	Triangle3 hitTriangle;

	// other types not implemented yet
	if (tObj->Type() == Intersectable::TRIANGLE_INTERSECTABLE)
		hitTriangle = static_cast<TriangleIntersectable *>(tObj)->GetItem();
	else
		cout << "border sampling: " << Intersectable::GetTypeName(tObj) << " not yet implemented" << endl;

	generationTimer.Entry();

	static VertexContainer enlargedTriangle;
	enlargedTriangle.clear();
	
	/// create 3 new hit points for each vertex
	EnlargeTriangle(enlargedTriangle, hitTriangle, currentRay);

	static VertexContainer subdivEnlargedTri;	
	subdivEnlargedTri.clear();

	for (size_t i = 0; i < enlargedTriangle.size(); ++ i)
	{
		const Vector3 p1 = enlargedTriangle[i];
		const Vector3 p2 = enlargedTriangle[(i + 1) % enlargedTriangle.size()];

		// the new subdivision point
		const Vector3 p = (p1 + p2) * 0.5f;

		subdivEnlargedTri.push_back(p1);
		subdivEnlargedTri.push_back(p);
	}

	/// create rays from sample points and handle them
	static SimpleRayContainer simpleRays;
	simpleRays.clear();
	
	VertexContainer::const_iterator vit, vit_end = subdivEnlargedTri.end();

	for (vit = subdivEnlargedTri.begin(); vit != vit_end; ++ vit)
	{
		const Vector3 rayDir = (*vit) - currentRay.GetOrigin();

		SimpleRay sr(currentRay.GetOrigin(), rayDir, SamplingStrategy::GVS, 1.0f);
		simpleRays.AddRay(sr);	
	}

	
	//////////
	//-- fill up simple rays with random rays so we can cast 16 rays at a time

	const int numRandomRays = 16 - ((int)simpleRays.size() % 16);

	SimpleRay mainRay = SimpleRay(currentRay.GetOrigin(), 
								  currentRay.GetNormalizedDir(), 
								  SamplingStrategy::GVS, 1.0f);

	GenerateJitteredRays(simpleRays, mainRay, numRandomRays, 0);
	//GenerateRays(numRandomRays, *mDistribution, simpleRays, sInvalidSamples);

	generationTimer.Exit();


	/////////////////////
	//-- cast rays to vertices and determine visibility
	
	static VssRayContainer vssRays;
	vssRays.clear();

	// for the original implementation we don't cast double rays
	const bool castDoubleRays = !mPerViewCell;
	// cannot prune invalid rays because we have to compare adjacent rays
	const bool pruneInvalidRays = false;

	//if ((simpleRays.size() % 16) != 0) cerr << "ray size not aligned" << endl;
	
	//gvsTimer.Entry();
	castTimer.Entry();

	CastRays(simpleRays, vssRays, castDoubleRays, pruneInvalidRays);
	
	castTimer.Exit();
	//gvsTimer.Exit();

	const int numBorderSamples = (int)vssRays.size() - numRandomRays;
	int castRays = (int)simpleRays.size();

	// handle cast rays
	EnqueueRays(vssRays);
	
#if 0
	
    // recursivly subdivide each edge
	for (int i = 0; i < numBorderSamples; ++ i)
	{
		castRays += SubdivideEdge(hitTriangle,
								  subdivEnlargedTri[i], 
								  subdivEnlargedTri[(i + 1) % numBorderSamples], 
								  *vssRays[i], 
								  *vssRays[(i + 1) % numBorderSamples],
								  currentRay);
	}
	
#endif


	mGvsStats.mBorderSamples += castRays;
	
	return castRays;
}


bool GvsPreprocessor::GetPassingPoint(const VssRay &currentRay,
									  const Triangle3 &occluder,
									  const VssRay &oldRay,
									  Vector3 &newPoint) const
{
	/////////////////////////
	//-- We interserct the plane p = (xp, hit(x), hit(xold))
	//-- with the newly found occluder (xold is the previous ray from
	//-- which x was generated). On the intersecting line, we select a point
	//-- pnew which lies just outside of the new triangle so the ray
	//-- just passes through the gap

	const Plane3 plane(currentRay.GetOrigin(), 
					   currentRay.GetTermination(), 
					   oldRay.GetTermination());
	
	Vector3 pt1, pt2;

	if (!occluder.GetPlaneIntersection(plane, pt1, pt2))
		return false;

	// get the intersection point on the old ray
	const Plane3 triPlane(occluder.GetNormal(), occluder.mVertices[0]);

	const float t = triPlane.FindT(oldRay.mOrigin, oldRay.mTermination);
	const Vector3 pt3 = oldRay.mOrigin + t * (oldRay.mTermination - oldRay.mOrigin);

	// evaluate new hitpoint just outside the triangle
	// the point is chosen to be on the side closer to the original ray
	if (SqrDistance(pt1, pt3) < SqrDistance(pt2, pt3))
		newPoint = pt1 + mEps * (pt1 - pt2);
	else
		newPoint = pt2 + mEps * (pt2 - pt1);

	//cout << "passing point: " << newPoint << endl << endl;
	return true;
}


bool GvsPreprocessor::ComputeReverseRay(const VssRay &currentRay,
										const Triangle3 &hitTriangle,
										const VssRay &oldRay,
										SimpleRay &reverseRay)
{
	// get triangle occluding the path to the hit mesh
	Triangle3 occluder;
	Intersectable *tObj = currentRay.mTerminationObject;

	// q: why can this happen?
	if (!tObj)
		return false;

	// other types not implemented yet
	if (tObj->Type() == Intersectable::TRIANGLE_INTERSECTABLE)
		occluder = static_cast<TriangleIntersectable *>(tObj)->GetItem();
	else
		cout << "reverse sampling: " << tObj->Type() << " not yet implemented" << endl;
	
	// get a point which is passing just outside of the occluder
    Vector3 newPoint;

	// q: why is there sometimes no intersecton found?
	if (!GetPassingPoint(currentRay, occluder, oldRay, newPoint))
		return false;

	const Vector3 predicted = CalcPredictedHitPoint(currentRay, hitTriangle, oldRay);

	Vector3 newDir, newOrigin;

	//////////////
	//-- Construct the mutated ray with xnew,
	//-- dir = predicted(x)- pnew as direction vector

	newDir = predicted - newPoint;

	// take xnew, p = intersect(viewcell, line(pnew, predicted(x)) as origin ?
	// difficult to say!!
	const float offset = 0.5f;
	newOrigin = newPoint - newDir * offset;
	

	//////////////
	//-- for per view cell sampling, we must check for intersection
	//-- with the current view cell

    if (mPerViewCell)
	{
		// send ray to view cell
		static Ray ray;

		ray.Clear();
		ray.Init(newOrigin, -newDir, Ray::LOCAL_RAY);
		
		// check if ray intersects view cell
		if (!mCurrentViewCell->CastRay(ray))
			return NULL;

		Ray::Intersection &hit = ray.intersections[0];
	
		// the ray starts from the view cell
		newOrigin = ray.Extrap(hit.mT);
	}

	reverseRay = SimpleRay(newOrigin, newDir, SamplingStrategy::GVS, 1.0f);

	return true;
}


int GvsPreprocessor::CastInitialSamples(int numSamples)
{	
	initialTimer.Entry();

	// generate simple rays
	static SimpleRayContainer simpleRays;
	simpleRays.clear();

	generationTimer.Entry();

	ViewCellBorderBasedDistribution vcStrat(*this, mCurrentViewCell);
	GenerateRays(numSamples, *mDistribution, simpleRays, sInvalidSamples);

	generationTimer.Exit();

	// cast generated samples 
	static VssRayContainer vssRays;
	vssRays.clear();

	castTimer.Entry();

	if (DETERMINISTIC_GVS)
	{
		const bool castDoubleRays = !mPerViewCell;
		const bool pruneInvalidRays = false;
		//const bool pruneInvalidRays = true;
		CastRays(simpleRays, vssRays, castDoubleRays, pruneInvalidRays);
	}
	else
	{
		if (0)
			// casting bundles of 4 rays generated from the simple rays
			CastRayBundles4(simpleRays, vssRays);
		else
			CastRayBundles16(simpleRays, vssRays);
	}

	castTimer.Exit();

	// add to ray queue
	EnqueueRays(vssRays);

	initialTimer.Exit();

	return (int)vssRays.size();
}


void GvsPreprocessor::EnqueueRays(VssRayContainer &samples)
{
	rayTimer.Entry();

	// add samples to ray queue
	VssRayContainer::const_iterator vit, vit_end = samples.end();
	for (vit = samples.begin(); vit != vit_end; ++ vit)
	{
		VssRay *ray = *vit;
		HandleRay(ray);
		// note: deletion of invalid samples handked by ray pool
	}

	rayTimer.Exit();
}


int GvsPreprocessor::ProcessQueue()
{
	gvsTimer.Entry();

	++ mGvsStats.mGvsRuns;

	int castSamples = 0;

	while (!mRayQueue.empty())
	{
		// handle next ray
		VssRay *ray = mRayQueue.top();
		mRayQueue.pop();
		
		if (1)
			castSamples += AdaptiveBorderSampling(*ray);
		else
			castSamples += AdaptiveBorderSamplingOpt(*ray);
		// note: don't have to delete because handled by ray pool
	}

	gvsTimer.Exit();

	return castSamples;
}


void ExportVssRays(Exporter *exporter, const VssRayContainer &vssRays)
{
	VssRayContainer vcRays, vcRays2, vcRays3;

	VssRayContainer::const_iterator rit, rit_end = vssRays.end();

	// prepare some rays for output
	for (rit = vssRays.begin(); rit != rit_end; ++ rit)
	{
		//const float p = RandomValue(0.0f, (float)vssRays.size());

		if (1)//(p < raysOut)
		{
			if ((*rit)->mFlags & VssRay::BorderSample)
				vcRays.push_back(*rit);
			else if ((*rit)->mFlags & VssRay::ReverseSample)
				vcRays2.push_back(*rit);
			else
				vcRays3.push_back(*rit);
		} 
	}

	exporter->ExportRays(vcRays, RgbColor(1, 0, 0));
	exporter->ExportRays(vcRays2, RgbColor(0, 1, 0));
	exporter->ExportRays(vcRays3, RgbColor(1, 1, 1));
}


void GvsPreprocessor::VisualizeViewCell(const ObjectContainer &objects)
{
    Intersectable::NewMail();
	Material m;
	
	char str[64]; sprintf_s(str, "pass%06d.wrl", mProcessedViewCells);

	Exporter *exporter = Exporter::GetExporter(str);
	if (!exporter)
		return;

	ObjectContainer::const_iterator oit, oit_end = objects.end();

	for (oit = objects.begin(); oit != oit_end; ++ oit)
	{
		Intersectable *intersect = *oit;
		
		m = RandomMaterial();
		exporter->SetForcedMaterial(m);
		exporter->ExportIntersectable(intersect);
	}

	cout << "vssrays: " << (int)mVssRays.size() << endl;
	ExportVssRays(exporter, mVssRays);


	/////////////////
	//-- export view cell geometry

	//exporter->SetWireframe();

	m.mDiffuseColor = RgbColor(0, 1, 0);
	exporter->SetForcedMaterial(m);

	AxisAlignedBox3 bbox = mCurrentViewCell->GetMesh()->mBox;
	exporter->ExportBox(bbox);
	//exporter->SetFilled();

	delete exporter;
}


void GvsPreprocessor::VisualizeViewCells()
{
	char str[64]; sprintf_s(str, "tmp/pass%06d_%04d-", mProcessedViewCells, mPass);
			
	// visualization
	if (mGvsStats.mPassContribution > 0)
	{
		const bool exportRays = true;
		const bool exportPvs = true;

		mViewCellsManager->ExportSingleViewCells(mObjects, 
												 10, 
												 false, 
												 exportPvs, 
												 exportRays, 
												 1000, 
												 str);
	}

	// remove pass samples
	ViewCellContainer::const_iterator vit, vit_end = mViewCellsManager->GetViewCells().end();

	for (vit = mViewCellsManager->GetViewCells().begin(); vit != vit_end; ++ vit)
	{
		(*vit)->DelRayRefs();
	}
}


void GvsPreprocessor::CompileViewCellsFromPointList()
{
	ViewCell::NewMail();

	// Receive list of view cells from view cells manager
	ViewCellPointsList *vcPoints = mViewCellsManager->GetViewCellPointsList();

	vector<ViewCellPoints *>::const_iterator vit, vit_end = vcPoints->end();

	for (vit = vcPoints->begin(); vit != vit_end; ++ vit)
	{
		ViewCellPoints *vp = *vit;

		if (vp->first) // view cell  specified
		{
			ViewCell *viewCell = vp->first;

			if (!viewCell->Mailed())
			{
				viewCell->Mail();
				mViewCells.push_back(viewCell);

				if (mViewCells.size() >= mMaxViewCells)
					break;
			}
		}
		else // no view cell specified => compute view cells using view point
		{
			SimpleRayContainer::const_iterator rit, rit_end = vp->second.end();

			for (rit = vp->second.begin(); rit != rit_end; ++ rit)
			{
				SimpleRay ray = *rit;

				ViewCell *viewCell = mViewCellsManager->GetViewCell(ray.mOrigin);

				if (viewCell && !viewCell->Mailed())
				{
					viewCell->Mail();
					mViewCells.push_back(viewCell);

					if (mViewCells.size() >= mMaxViewCells)
						break;
				}
			}
		}
	}
}


void GvsPreprocessor::CompileViewCellsList()
{
	if (!mViewCellsManager->GetViewCellPointsList()->empty())
	{
		cout << "processing view point list" << endl;
		CompileViewCellsFromPointList();
	}
	else
	{
		ViewCell::NewMail();

		while ((int)mViewCells.size() < mMaxViewCells)
		{
			const int tries = 10000;
			int i = 0;

			for (i = 0; i < tries; ++ i)
			{
				const int idx = (int)RandomValue(0.0f, (float)mViewCellsManager->GetNumViewCells() - 0.5f);

				ViewCell *viewCell = mViewCellsManager->GetViewCell(idx);

				if (!viewCell->Mailed())
				{
					viewCell->Mail();
					break;
				}

				mViewCells.push_back(viewCell);
			}

			if (i == tries)
			{
				cerr << "big error! no view cell found" << endl;
				break;
			}
		}
	}

	cout << "\ncomputing list of " << mViewCells.size() << " view cells" << endl;
}


void GvsPreprocessor::ComputeViewCellGeometryIntersection()
{
	intersectionTimer.Entry();

	AxisAlignedBox3 box = mCurrentViewCell->GetBox();

	int oldTrianglePvs = (int)mTrianglePvs.size();
	int newKdObj = 0;

	// compute pvs kd nodes that intersect view cell
	ObjectContainer kdobjects;

	// find intersecting objects not in pvs (i.e., only unmailed)
	mKdTree->CollectKdObjects(box, kdobjects);

	ObjectContainer pvsKdObjects;

	ObjectContainer::const_iterator oit, oit_end = kdobjects.end();

	for (oit = kdobjects.begin(); oit != oit_end; ++ oit)
	{
       	KdIntersectable *kdInt = static_cast<KdIntersectable *>(*oit);
	
		myobjects.clear();
		mKdTree->CollectObjectsWithDublicates(kdInt->GetItem(), myobjects);

		// account for kd object pvs
		bool addkdobj = false;

		ObjectContainer::const_iterator oit, oit_end = myobjects.end();

		for (oit = myobjects.begin(); oit != oit_end; ++ oit)
		{
			TriangleIntersectable *triObj = static_cast<TriangleIntersectable *>(*oit);
             
			// test if the triangle itself intersects
			if (box.Intersects(triObj->GetItem()))
				addkdobj = AddTriangleObject(triObj);
		}
		
		// add node to kd pvs
		if (1 && addkdobj)
		{
			++ newKdObj;
			mCurrentViewCell->GetPvs().AddSampleDirty(kdInt, 1.0f);
			//mCurrentViewCell->GetPvs().AddSampleDirtyCheck(kdInt, 1.0f);
			if (QT_VISUALIZATION_SHOWN) UpdateStatsForVisualization(kdInt);
		}
	}

	cout << "added " << (int)mTrianglePvs.size() - oldTrianglePvs << " triangles (" << newKdObj << " objects) by intersection" << endl;

	intersectionTimer.Exit();
}


void GvsPreprocessor::PerViewCellComputation()
{
	while (mCurrentViewCell = NextViewCell())
	{
		preparationTimer.Entry();

		// hack: reset counters (could be done with a mailing-like approach
		ObjectContainer::const_iterator oit, oit_end = mObjects.end();
		for (oit = mObjects.begin(); oit != oit_end; ++ oit)
			(*oit)->mCounter = NOT_ACCOUNTED_OBJECT;

		preparationTimer.Exit();

		mDistribution->SetViewCell(mCurrentViewCell);

        ComputeViewCell();
	}
}


void GvsPreprocessor::PerViewCellComputation2()
{
	while (1)
	{
		if (!mRendererWidget)
			continue;

        mCurrentViewCell = mViewCellsManager->GetViewCell(mRendererWidget->GetViewPoint());

		// no valid view cell or view cell already computed
		if (!mCurrentViewCell || !mCurrentViewCell->GetPvs().Empty() || !mRendererWidget->mComputeGVS)
			continue;

		mRendererWidget->mComputeGVS = false;
		// hack: reset counters
		ObjectContainer::const_iterator oit, oit_end = mObjects.end();

		for (oit = mObjects.begin(); oit != oit_end; ++ oit)
			(*oit)->mCounter = NOT_ACCOUNTED_OBJECT;

		ComputeViewCell();
		++ mProcessedViewCells;
	}
}


void GvsPreprocessor::StorePvs(const ObjectContainer &objectPvs)
{
	ObjectContainer::const_iterator oit, oit_end = objectPvs.end();

	for (oit = objectPvs.begin(); oit != oit_end; ++ oit)
	{
		mCurrentViewCell->GetPvs().AddSample(*oit, 1);
	}
}


void GvsPreprocessor::UpdatePvs(ViewCell *currentViewCell)
{
	ObjectPvs newPvs;
	BvhLeaf::NewMail();

	ObjectPvsIterator pit = currentViewCell->GetPvs().GetIterator();

	// output PVS of view cell
	while (pit.HasMoreEntries())
	{		
		Intersectable *intersect = pit.Next();

		BvhLeaf *bv = intersect->mBvhLeaf;

		if (!bv || bv->Mailed())
			continue;
		
		bv->Mail();

		//m.mDiffuseColor = RgbColor(1, 0, 0);
		newPvs.AddSampleDirty(bv, 1.0f);
	}

	newPvs.SimpleSort();

	currentViewCell->SetPvs(newPvs);
}

 
void GvsPreprocessor::GetObjectPvs(ObjectContainer &objectPvs) const
{
	BvhLeaf::NewMail();

	objectPvs.reserve((int)mTrianglePvs.size());

	ObjectContainer::const_iterator oit, oit_end = mTrianglePvs.end();

	for (oit = mTrianglePvs.begin(); oit != oit_end; ++ oit)
	{
		Intersectable *intersect = *oit;
	
		BvhLeaf *bv = intersect->mBvhLeaf;

		// hack: reset counter
		(*oit)->mCounter = NOT_ACCOUNTED_OBJECT;

		if (!bv || bv->Mailed())
			continue;

		bv->Mail();
		objectPvs.push_back(bv);
	}
}


void GvsPreprocessor::GlobalComputation()
{
	int passSamples = 0;
	int randomSamples = 0;
	int gvsSamples = 0;
	int oldContribution = 0;

	while (mGvsStats.mTotalSamples < mTotalSamples) 
	{
		mRayCaster->InitPass();

		int newRandomSamples, newGvsSamples;

		// Ray queue empty => 
		// cast a number of uniform samples to fill ray queue
		newRandomSamples = CastInitialSamples(mInitialSamples);
		
		if (!mOnlyRandomSampling)
			newGvsSamples = ProcessQueue();

		passSamples += newRandomSamples + newGvsSamples;
		mGvsStats.mTotalSamples += newRandomSamples + newGvsSamples;

		mGvsStats.mRandomSamples += newRandomSamples;
		mGvsStats.mGvsSamples += newGvsSamples;


		if (passSamples % (mGvsSamplesPerPass + 1) == mGvsSamplesPerPass)
		{
			++ mPass;

			mGvsStats.mPassContribution = mGvsStats.mTotalContribution - oldContribution;
			
			////////
			//-- stats

			//cout << "\nPass " << mPass << " #samples: " << mGvsStats.mTotalSamples << " of " << mTotalSamples << endl;
			mGvsStats.mPass = mPass;
			mGvsStats.Stop();
			mGvsStats.Print(mGvsStatsStream);

			// reset
			oldContribution = mGvsStats.mTotalContribution;
			mGvsStats.mPassContribution = 0;
			passSamples = 0;

			if (GVS_DEBUG)
				VisualizeViewCells();
		}
	}
}


bool GvsPreprocessor::ComputeVisibility()
{
	cout << "Gvs Preprocessor started\n" << flush;
	const long startTime = GetTime();

	//Randomize(0);
	mGvsStats.Reset();
	mGvsStats.Start();

	if (!mLoadViewCells)
	{	
		/// construct the view cells from the scratch
		ConstructViewCells();
		// reset pvs already gathered during view cells construction
		mViewCellsManager->ResetPvs();
		cout << "finished view cell construction" << endl;
	}

	if (mPerViewCell)
	{
#if 1
		// provide list of view cells to compute
		CompileViewCellsList();

		// start per view cell gvs
		PerViewCellComputation();
#else
		PerViewCellComputation2();

#endif
	}
	else
	{
		GlobalComputation();
	}

	cout << "cast " << mGvsStats.mTotalSamples / (1e3f * TimeDiff(startTime, GetTime())) << "M single rays/s" << endl;

	if (GVS_DEBUG)
	{
		Visualize();
		CLEAR_CONTAINER(mVssRays);
	}
	
	// export the preprocessed information to a file
	if (0 && mExportVisibility)
		ExportPreprocessedData(mVisibilityFileName);
	
	// compute the pixel error of this visibility solution
	if (0 && mEvaluatePixelError)
		ComputeRenderError();

	return true;
}


void GvsPreprocessor::DeterminePvsObjects(VssRayContainer &rays)
{
	// store triangle directly
	mViewCellsManager->DeterminePvsObjects(rays, true);
}


void GvsPreprocessor::Visualize()
{
	Exporter *exporter = Exporter::GetExporter("gvs.wrl");

	if (!exporter)
		return;
	
	vector<VizStruct>::const_iterator vit, vit_end = vizContainer.end();
	
	for (vit = vizContainer.begin(); vit != vit_end; ++ vit)
	{
		exporter->SetWireframe();
		exporter->ExportPolygon((*vit).enlargedTriangle);
		//Material m;
		exporter->SetFilled();
		Polygon3 poly = Polygon3((*vit).originalTriangle);
		exporter->ExportPolygon(&poly);
	}

	VssRayContainer::const_iterator rit, rit_end = mVssRays.end();

	for (rit = mVssRays.begin(); rit != rit_end; ++ rit)
	{
		Intersectable *obj = (*rit)->mTerminationObject;
		exporter->ExportIntersectable(obj);
	}

	ExportVssRays(exporter, mVssRays);
	
	delete exporter;
}


void GvsStatistics::Print(ostream &app) const
{
	app << "#ViewCells\n" << mViewCells << endl;
	app << "#Id\n" << mViewCellId << endl;
	app << "#Time\n" << mTimePerViewCell << endl;;
	app << "#TriPvs\n" << mTrianglePvs << endl;
	app << "#ObjectPvs\n" << mPerViewCellPvs << endl;
	app << "#UpdatedPvs\n" << (int)mPvsCost << endl;

	app << "#PerViewCellSamples\n" << mPerViewCellSamples << endl;
	app << "#RaysPerSec\n" << RaysPerSec() << endl;
	
	app << "#TotalPvs\n" << mTotalPvs << endl;
	app << "#TotalTime\n" << mTotalTime << endl;
	app << "#TotalSamples\n" << mTotalSamples << endl;

	app << "#AvgPvs: " << mPvsCost / mViewCells << endl;
	app << "#TotalTrianglePvs\n" << mTotalTrianglePvs << endl;
	
	if (0)
	{
		app << "#ReverseSamples\n" << mReverseSamples << endl;
		app << "#BorderSamples\n" << mBorderSamples << endl;

		app << "#Pass\n" << mPass << endl;
		app << "#ScDiff\n" << mPassContribution << endl;
		app << "#GvsRuns\n" << mGvsRuns << endl;	

		app	<< "#SamplesContri\n" << mTotalContribution << endl;
	}

	app << endl;
}


void GvsPreprocessor::ComputeViewCell()
{
	const long startTime = GetTime();

	// initialise
	mGvsStats.mPerViewCellSamples = 0;
	mGvsStats.mRandomSamples = 0;
	mGvsStats.mGvsSamples = 0;

	//renderer->mPvsStat.currentPass = 0;
	mPass = 0;

	int oldContribution = 0;
	int passSamples = 0;

	for (int i = 0; i < 2; ++ i)
		mGenericStats[i] = 0;

	mTrianglePvs.clear();


	// hack: take bounding box of view cell as view cell bounds
	mCurrentViewCell->GetMesh()->ComputeBoundingBox();

	// use mailing for kd node pvs
	KdNode::NewMail();

	cout << "\n***********************\n" 
		<< "computing view cell " << mProcessedViewCells 
		<< " (id: " << mCurrentViewCell->GetId() << ")" << endl;
	cout << "bb: " << mCurrentViewCell->GetBox() << endl;

	mainLoopTimer.Entry();

	while (1)
	{
		sInvalidSamples = 0;
		int oldPvsSize = mCurrentViewCell->GetPvs().GetSize();
		
		mRayCaster->InitPass();

		int newRandomSamples, newGvsSamples, newSamples;

		// Ray queue empty => 
		// cast a number of uniform samples to fill ray queue
		newRandomSamples = CastInitialSamples(mInitialSamples);
		
		if (!mOnlyRandomSampling)
			newGvsSamples = ProcessQueue();

		newSamples = newRandomSamples + newGvsSamples;

		passSamples += newSamples;
		mGvsStats.mPerViewCellSamples += newSamples;

		mGvsStats.mRandomSamples += newRandomSamples;
		mGvsStats.mGvsSamples += newGvsSamples;


		if (passSamples >= mGvsSamplesPerPass)
		{
			if (GVS_DEBUG) VisualizeViewCell(mTrianglePvs);

			//const bool convertPerPass = true;
			const bool convertPerPass = false;

			if (convertPerPass)
			{	
				int newObjects = ConvertObjectPvs();

				cout << "added " << newObjects << " triangles to triangle pvs" << endl;
				mGvsStats.mTotalContribution += newObjects;
			}

			++ mPass;
			mGvsStats.mPassContribution = mGvsStats.mTotalContribution - oldContribution;


			////////
			//-- stats

			mGvsStats.mPass = mPass;

			cout << "\nPass " << mPass << " #samples: " << mGvsStats.mPerViewCellSamples << endl;
			cout << "contribution=" << mGvsStats.mPassContribution << " (of " << mMinContribution << ")" << endl;
			cout << "obj contri=" << mCurrentViewCell->GetPvs().GetSize() - oldPvsSize << " (of " << mMinContribution << ")" << endl;

			// termination criterium
			if (mGvsStats.mPassContribution < mMinContribution)
				break;

			// reset stats
			oldContribution = mGvsStats.mTotalContribution;
			mGvsStats.mPassContribution = 0;
			passSamples = 0;
			
			// compute the pixel error of this visibility solution
			if (0 && mEvaluatePixelError)
				ComputeRenderError();
		}
	}
	
	mainLoopTimer.Exit();

	// at last compute objects that directly intersect view cell
	ComputeViewCellGeometryIntersection();
		
	// compute the pixel error of this visibility solution
	if (mEvaluatePixelError)
		ComputeRenderError();

	////////
	//-- stats

	// timing
	mGvsStats.mTimePerViewCell = TimeDiff(startTime, GetTime()) * 1e-3f;

	ComputeStats();
}


void GvsPreprocessor::ComputeStats()
{
	// compute pvs size using larger (bvh objects)
	// note: for kd pvs we had to do this during gvs computation
	if (!mUseKdPvs)
	{
		ObjectContainer objectPvs;

		// optain object pvs
		GetObjectPvs(objectPvs);

		// add pvs
		ObjectContainer::const_iterator it, it_end = objectPvs.end();

		for (it = objectPvs.begin(); it != it_end; ++ it)
		{
			mCurrentViewCell->GetPvs().AddSampleDirty(*it, 1.0f);
		}

		cout << "triangle pvs of " << (int)mTrianglePvs.size() 
			<< " was converted to object pvs of " << (int)objectPvs.size() << endl;

		mGvsStats.mPerViewCellPvs = (int)objectPvs.size();
		mGvsStats.mPvsCost = 0; // todo objectPvs.EvalPvsCost();
	}
	else
	{
		 if (0) // compute pvs kd nodes that intersect view cell
		 {
			 ObjectContainer mykdobjects;

			 // extract kd pvs
			 ObjectContainer::const_iterator it, it_end = mTrianglePvs.end();

			 for (it = mTrianglePvs.begin(); it != it_end; ++ it)
			 {
				 Intersectable *obj = *it;
				 // find intersecting objects not yet in pvs (i.e., only unmailed)
				 mKdTree->CollectKdObjects(obj->GetBox(), mykdobjects);
			 }

			 // add pvs
			 it_end = mykdobjects.end();

			 for (it = mykdobjects.begin(); it != it_end; ++ it)
			 {
				 mCurrentViewCell->GetPvs().AddSampleDirty(*it, 1.0f);
			 }
		 
			 cout << "added " << (int)mykdobjects.size() << " new objects " << endl;
		 }

		 mGvsStats.mPerViewCellPvs = mCurrentViewCell->GetPvs().GetSize();
		 mGvsStats.mPvsCost = mCurrentViewCell->GetPvs().EvalPvsCost();

	}

	mGvsStats.mTrianglePvs = (int)mTrianglePvs.size();


	////////////////
	// global values

	mGvsStats.mViewCells = mProcessedViewCells;
	mGvsStats.mTotalTrianglePvs += mGvsStats.mTrianglePvs;
	mGvsStats.mTotalTime += mGvsStats.mTimePerViewCell;
    mGvsStats.mTotalPvs += mGvsStats.mPerViewCellPvs;
	mGvsStats.mTotalSamples += mGvsStats.mPerViewCellSamples;

	cout << "id: " << mCurrentViewCell->GetId() << endl;
	cout << "pvs cost "  << mGvsStats.mPvsCost / 1000000 << " M" << endl;
	cout << "pvs tri: " << mTrianglePvs.size() << endl;
	cout << "samples: " << mGvsStats.mTotalSamples / 1000000 << " M" << endl;
	printf("contri: %f tri / K rays\n", 1000.0f * (float)mTrianglePvs.size() / mGvsStats.mTotalSamples);

	//cout << "invalid samples ratio: " << (float)sInvalidSamples / mGvsStats.mPerViewCellSamples << endl;

	double rayTime = rayTimer.TotalTime();
	double kdPvsTime = kdPvsTimer.TotalTime();
	double gvsTime = gvsTimer.TotalTime();
	double initialTime = initialTimer.TotalTime();
	double intersectionTime = intersectionTimer.TotalTime();
	double preparationTime = preparationTimer.TotalTime();
	double mainLoopTime = mainLoopTimer.TotalTime();
	double contributionTime = contributionTimer.TotalTime();
	double castTime = castTimer.TotalTime();
	double generationTime = generationTimer.TotalTime();
	double rawCastTime = mRayCaster->rawCastTimer.TotalTime();

	cout << "handleRay              : " << rayTime << endl;
	cout << "kd pvs                 : " << kdPvsTime << endl;
	cout << "gvs sampling           : " << gvsTime << endl;
	cout << "initial sampling       : " << initialTime << endl;
	cout << "view cell intersection : " << intersectionTime << endl;
	cout << "preparation            : " << preparationTime << endl;
	cout << "main loop              : " << mainLoopTime << endl;
	cout << "has contribution       : " << contributionTime << endl;
	cout << "cast time              : " << castTime << endl;
	cout << "generation time        : " << generationTime << endl;
	cout << "raw cast time          : " << rawCastTime << endl;

	double randomRaysPerSec = mGvsStats.mRandomSamples / (1e6 * initialTime);
	double gvsRaysPerSec = mGvsStats.mGvsSamples / (1e6 * gvsTime);
	double rawRaysPerSec = mGvsStats.mPerViewCellSamples / (1e6 * rawCastTime);

	cout << "cast " << randomRaysPerSec << " M random rays/s: " << endl;
	cout << "cast " << gvsRaysPerSec << " M gvs rays/s: " << endl;
	cout << "cast " << rawRaysPerSec << " M raw rays/s: " << endl;

	mGvsStats.Stop();
	mGvsStats.Print(mGvsStatsStream);
}


int GvsPreprocessor::ConvertObjectPvs()
{
	static ObjectContainer triangles;

	int newObjects = 0;

	ObjectPvsIterator pit = mCurrentViewCell->GetPvs().GetIterator();

	triangles.clear();

	// output PVS of view cell
	while (pit.HasMoreEntries())
	{		
		KdIntersectable *kdInt = static_cast<KdIntersectable *>(pit.Next());

		mKdTree->CollectObjectsWithDublicates(kdInt->GetItem(), triangles);

		ObjectContainer::const_iterator oit, oit_end = triangles.end();

		for (oit = triangles.begin(); oit != oit_end; ++ oit)
		{
			if (AddTriangleObject(*oit))
				++ newObjects;
		}
	}

	return newObjects;
}


bool GvsPreprocessor::AddTriangleObject(Intersectable *triObj)
{
	if ((triObj->mCounter < ACCOUNTED_OBJECT))
	{
		triObj->mCounter += ACCOUNTED_OBJECT;

		mTrianglePvs.push_back(triObj);
		mGenericStats[0] = (int)mTrianglePvs.size();

		return true;
	}

	return false;
}


void GvsPreprocessor::CastRayBundles4(const SimpleRayContainer &rays, VssRayContainer &vssRays)
{
	AxisAlignedBox3 box = mViewCellsManager->GetViewSpaceBox();

	SimpleRayContainer::const_iterator it, it_end = rays.end();

	for (it = rays.begin(); it != it_end; ++ it)
		CastRayBundle4(*it, vssRays, box);
}


void GvsPreprocessor::CastRayBundle4(const SimpleRay &ray, 
									 VssRayContainer &vssRays, 
									 const AxisAlignedBox3 &box)
{
	const float pertubDir = 0.01f;
	static Vector3 pertub;

	static int hit_triangles[4];
	static float dist[4];
	static Vector3 dirs[4];
	static Vector3 origs[4];

	origs[0] = ray.mOrigin;
	dirs[0] = ray.mDirection;

	for (int i = 1; i < 4; ++ i) 
	{
		origs[i] = ray.mOrigin;

		pertub.x = RandomValue(-pertubDir, pertubDir);
		pertub.y = RandomValue(-pertubDir, pertubDir);
		pertub.z = RandomValue(-pertubDir, pertubDir);

		dirs[i] = ray.mDirection + pertub;
		dirs[i] *= 1.0f / Magnitude(dirs[i]);
	}

	Cast4Rays(dist, dirs, origs, vssRays, box);
}


void GvsPreprocessor::CastRays4(const SimpleRayContainer &rays, VssRayContainer &vssRays)
{
	SimpleRayContainer::const_iterator it, it_end = rays.end();
	
	static float dist[4];
	static Vector3 dirs[4];
	static Vector3 origs[4];

	AxisAlignedBox3 box = mViewCellsManager->GetViewSpaceBox();

	for (it = rays.begin(); it != it_end; ++ it)
	{
		for (int i = 1; i < 4; ++ i) 
		{
			origs[i] = rays[i].mOrigin;
			dirs[i] = rays[i].mDirection;
		}
	}

	Cast4Rays(dist, dirs, origs, vssRays, box);
}


void GvsPreprocessor::Cast4Rays(float *dist,
								Vector3 *dirs,
								Vector3 *origs,
								VssRayContainer &vssRays,
								const AxisAlignedBox3 &box)
{
	static int hit_triangles[4];

	mRayCaster->CastRaysPacket4(box.Min(), box.Max(), origs, dirs, hit_triangles,	dist);       

	VssRay *ray;

	for (int i = 0; i < 4; ++ i)
	{
		if (hit_triangles[i] != -1)
		{
			TriangleIntersectable *triObj = static_cast<TriangleIntersectable *>(mObjects[hit_triangles[i]]);

			if (DotProd(triObj->GetItem().GetNormal(), dirs[i] >= 0))
				ray = NULL;
			else
				ray = mRayCaster->RequestRay(origs[i], origs[i] + dirs[i] * dist[i], NULL, triObj, mPass, 1.0f);
		}
		else
		{
			ray = NULL;
		}

		vssRays.push_back(ray);
	}
}


void GvsPreprocessor::CastRayBundle16(const SimpleRay &ray, VssRayContainer &vssRays)
{
	static SimpleRayContainer simpleRays;
	simpleRays.clear();

	simpleRays.push_back(ray);
	GenerateJitteredRays(simpleRays, ray, 15, 0);

	CastRays(simpleRays, vssRays, false, false);
}


void GvsPreprocessor::CastRayBundles16(const SimpleRayContainer &rays, VssRayContainer &vssRays)
{
	SimpleRayContainer::const_iterator it, it_end = rays.end();

	for (it = rays.begin(); it != it_end; ++ it)
		CastRayBundle16(*it, vssRays);
}


void GvsPreprocessor::ComputeRenderError()
{
	// compute rendering error	
	if (renderer && renderer->mPvsStatFrames) 
	{
		if (!mViewCellsManager->GetViewCellPointsList()->empty()) 
		{
			ViewCellPointsList *vcPoints = mViewCellsManager->GetViewCellPointsList();
			ViewCellPointsList::const_iterator vit = vcPoints->begin(),	vit_end = vcPoints->end();

			SimpleRayContainer viewPoints;

			for (; vit != vit_end; ++ vit) 
			{
				ViewCellPoints *vp = *vit;
				
				SimpleRayContainer::const_iterator rit = vp->second.begin(), rit_end = vp->second.end();
			
				for (; rit!=rit_end; ++rit)
				{
					ViewCell *vc = mViewCellsManager->GetViewCell((*rit).mOrigin);
					if (vc == mCurrentViewCell)
						viewPoints.push_back(*rit);
				}
			}

			renderer->mPvsErrorBuffer.clear();

			if (viewPoints.size() != renderer->mPvsErrorBuffer.size()) 
			{
				renderer->mPvsErrorBuffer.resize(viewPoints.size());
				renderer->ClearErrorBuffer();
			}

			cout << "evaluating list of " << viewPoints.size() << " pts" << endl;
			renderer->EvalPvsStat(viewPoints);
		} 
		else
		{
			cout << "evaluating random points" << endl;
			renderer->EvalPvsStat();
		}

		mStats <<
			"#AvgPvsRenderError\n" <<renderer->mPvsStat.GetAvgError()<<endl<<
			"#AvgPixelError\n" <<renderer->GetAvgPixelError()<<endl<<
			"#MaxPixelError\n" <<renderer->GetMaxPixelError()<<endl<<
			"#MaxPvsRenderError\n" <<renderer->mPvsStat.GetMaxError()<<endl<<
			"#ErrorFreeFrames\n" <<renderer->mPvsStat.GetErrorFreeFrames()<<endl<<
			"#AvgRenderPvs\n" <<renderer->mPvsStat.GetAvgPvs()<<endl;
	}
}


void GvsPreprocessor::GenerateImportanceSamples(const VssRay &ray, 
												const Triangle3 &triangle, 
												int numSamples,
												SimpleRayContainer &simpleRays)
{
	const size_t samplesSize = simpleRays.size();

	while (simpleRays.size() < (samplesSize + numSamples))
	{
		SimpleRay sray;
		if (GenerateImportanceSample(ray, triangle, sray))
			simpleRays.push_back(sray);
	}
}


bool GvsPreprocessor::GenerateImportanceSample(const VssRay &ray, 
											   const Triangle3 &triangle, 
											   SimpleRay &sray)
{
	Vector3 d = ray.GetDir();
  
	// Compute right handed coordinate system from direction
	Vector3 U, V;

	Vector3 nd = Normalize(d);
	nd.RightHandedBase(U, V);
	
	Vector3 origin = ray.mOrigin;
	Vector3 termination = ray.mTermination;

	float rr[2];

	rr[0] = RandomValue(0, 1);
	rr[1] = RandomValue(0, 1);

	Vector2 vr2(rr[0], rr[1]);
	const float sigma = triangle.GetBoundingBox().Radius() * 3.0f;
	Vector2 gaussvec2;

	GaussianOn2D(vr2, sigma, // input
		         gaussvec2); // output
	
	const Vector3 shift = gaussvec2.xx * U + gaussvec2.yy * V;

	//cout << "t: " << termination;
	termination += shift;
	//cout << " new t: " << termination << endl;
	Vector3 direction = termination - origin;

	const float len = Magnitude(direction);
	
	if (len < Limits::Small)
		return false;
  
	direction /= len;

	// $$ jb the pdf is yet not correct for all sampling methods!
	const float pdf = 1.0f;
	sray = SimpleRay(origin, direction, SamplingStrategy::GVS, pdf);
	
	return true;
}


}