#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"


namespace GtpVisibilityPreprocessor
{
  
#define GVS_DEBUG 1

struct VizStruct
{
	Polygon3 *enlargedTriangle;
	Triangle3 originalTriangle;
	VssRay *ray;
};

static const float MIN_DIST = 0.01f;

static vector<VizStruct> vizContainer;

GvsPreprocessor::GvsPreprocessor(): 
Preprocessor(), 
mSamplingType(SamplingStrategy::VIEWCELL_BASED_DISTRIBUTION),
//mSamplingType(SamplingStrategy::DIRECTION_BASED_DISTRIBUTION),
mNumViewCells(0),
mCurrentViewCell(NULL)
{
	Environment::GetSingleton()->GetIntValue("GvsPreprocessor.totalSamples", mTotalSamples);
	Environment::GetSingleton()->GetIntValue("GvsPreprocessor.initialSamples", mInitialSamples);
	Environment::GetSingleton()->GetIntValue("GvsPreprocessor.samplesPerPass", mSamplesPerPass);
	Environment::GetSingleton()->GetFloatValue("GvsPreprocessor.epsilon", mEps);
	Environment::GetSingleton()->GetFloatValue("GvsPreprocessor.threshold", mThreshold);	
	Environment::GetSingleton()->GetBoolValue("GvsPreprocessor.perViewCell", mPerViewCell);

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

	Debug << "Gvs preprocessor options" << endl;
	Debug << "number of total samples: " << mTotalSamples << endl;
	Debug << "number of initial samples: " << mInitialSamples << endl;
	Debug << "number of samples per pass: " << mSamplesPerPass << endl;
	Debug << "threshold: " << mThreshold << endl;
	Debug << "epsilon: " << mEps << endl;
	Debug << "stats: " << gvsStatsLog << endl;

	if (1)
		mOnlyRandomSampling = false;		
	else
		mOnlyRandomSampling = true;

	mGvsStats.Reset();
}


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

		delete ray;
	}
}


bool GvsPreprocessor::NextViewCell()
{
	if (mViewCellsManager->GetNumViewCells() == mNumViewCells)
		return false; // no more view cells

    if (1)
		mCurrentViewCell = mViewCellsManager->GetViewCell(mNumViewCells);
	else
	{
		// HACK
		int idx = (int)RandomValue(0.0f, (float)mViewCellsManager->GetNumViewCells() - 0.5f);
		mCurrentViewCell = mViewCellsManager->GetViewCell(idx);
	}

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

	++ mNumViewCells;
    
	return true;
}


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

	const float predictedLen = Magnitude(predictedHit - currentRay.mOrigin);
	const float len = Magnitude(currentRay.mTermination - currentRay.mOrigin);
	
	// distance large => this is likely to be a discontinuity
#if 1
	if ((predictedLen - len) > mThreshold)
#else // rather use relative distance
	if ((predictedLen / len) > mThreshold)
#endif
	{
		//cout << "r";
		// apply reverse sampling to find the gap
		VssRay *newRay = ReverseSampling(currentRay, hitTriangle, oldRay);

		if (!newRay)
			return false;

		// set flag for visualization
		newRay->mFlags |= VssRay::ReverseSample;
		
		// if ray is not further processed => delete ray
		if (!HandleRay(newRay))
		{
			delete newRay;
		}
		else if (0 && GVS_DEBUG && (mVssRays.size() < 9))
		{
			mVssRays.push_back(new VssRay(oldRay));
			mVssRays.push_back(new VssRay(currentRay));
			mVssRays.push_back(new VssRay(*newRay));
		}

		return true;
	}

	return false;
}


bool GvsPreprocessor::HandleRay(VssRay *vssRay)
{
	// store the rays + the intersected view cells
	const bool storeRaysForViz = false; //GVS_DEBUG;

	if (!mPerViewCell)
	{
		mViewCellsManager->ComputeSampleContribution(*vssRay, 
													 true, 
													 storeRaysForViz,
													 true);
	}
	else
	{
		mViewCellsManager->ComputeSampleContribution(*vssRay, 
													 true, 
													 mCurrentViewCell,
													 true);
	}

	// some pvs contribution for this ray?
	if (!vssRay->mPvsContribution)
		return false;

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

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

	if (storeRaysForViz)
	{
		VssRay *nray = new VssRay(*vssRay);
		nray->mFlags = vssRay->mFlags;

		// store ray in contributing view cell
		ViewCellContainer::const_iterator vit, vit_end = vssRay->mViewCells.end();
		for (vit = vssRay->mViewCells.begin(); vit != vit_end; ++ vit)
		{			
			(*vit)->GetOrCreateRays()->push_back(nray);				
		}
	}

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

	if (EqualVisibility(ray1, ray2) || (Magnitude(p1 - p2) <= MIN_DIST))
	{
		return 0;
	}
	
	// the new subdivision point
	const Vector3 p = (p1 + p2) * 0.5f;

	// cast ray into the new point
	SimpleRay sray(oldRay.mOrigin, p - oldRay.mOrigin, SamplingStrategy::GVS, 1.0f);

	VssRay *newRay = mRayCaster->CastRay(sray, mViewCellsManager->GetViewSpaceBox(), mPerViewCell);

	if (!newRay) return 0;

	newRay->mFlags |= VssRay::BorderSample;

	// add new ray to queue
	const bool enqueued = HandleRay(newRay);

	// subdivide further
	const int samples1 = SubdivideEdge(hitTriangle, p1, p, ray1, *newRay, oldRay);
	const int samples2 = SubdivideEdge(hitTriangle, p, p2, *newRay, ray2, oldRay);

	// this ray will not be further processed
	if (!enqueued)
		delete newRay;

	return samples1 + samples2 + 1;
}


int GvsPreprocessor::AdaptiveBorderSampling(const VssRay &currentRay)
{
	Intersectable *tObj = currentRay.mTerminationObject;
	Triangle3 hitTriangle;

	// other types not implemented yet
	if (tObj->Type() == Intersectable::TRIANGLE_INTERSECTABLE)
	{
		hitTriangle = dynamic_cast<TriangleIntersectable *>(tObj)->GetItem();
	}
	else
	{
		cout << "not yet implemented" << endl;
	}

	VertexContainer enlargedTriangle;
	
	/// create 3 new hit points for each vertex
	EnlargeTriangle(enlargedTriangle, hitTriangle, currentRay);
	
	/// create rays from sample points and handle them
	SimpleRayContainer simpleRays;
	simpleRays.reserve(9);

	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);
	}

	// cast rays to triangle vertices and determine visibility
	VssRayContainer vssRays;

	// don't cast double rays as we need only the forward rays
	const bool castDoubleRays = false;
	// cannot prune invalid rays because we have to compare adjacent  rays.
	const bool pruneInvalidRays = false;

	// keep origin for per view cell sampling
	CastRays(simpleRays, vssRays, castDoubleRays, pruneInvalidRays, mPerViewCell);

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

	// handle rays
	EnqueueRays(vssRays);
	
	const int n = (int)vssRays.size();
	int castRays = n;
	
    // recursivly subdivide each edge
	for (int i = 0; i < n; ++ i)
	{
		castRays += SubdivideEdge(hitTriangle,
								  enlargedTriangle[i], 
								  enlargedTriangle[(i + 1) % n], 
								  *vssRays[i], 
								  *vssRays[(i + 1) % n],
								  currentRay);
	}

	mGvsStats.mBorderSamples += castRays;

	return castRays;
}


Vector3 GvsPreprocessor::GetPassingPoint(const VssRay &currentRay,
										 const Triangle3 &occluder,
										 const VssRay &oldRay) const
{
	//-- The plane p = (xp, hit(x), hit(xold)) is intersected
	//-- 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;

	const bool intersects = occluder.GetPlaneIntersection(plane, pt1, pt2);

	if (!intersects)
		cerr << "big error!! no intersection" << endl;

	// 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
	Vector3 newPoint;

	const float eps = mEps;

	// the point is chosen to be on the side closer to the original ray
	if (Distance(pt1, pt3) < Distance(pt2, pt3))
	{
		newPoint = pt1 + eps * (pt1 - pt2);
	}	
	else
	{
		newPoint = pt2 + eps * (pt2 - pt1);
	}

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


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

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

	// other types not implemented yet
	if (tObj->Type() == Intersectable::TRIANGLE_INTERSECTABLE)
		occluder = dynamic_cast<TriangleIntersectable *>(tObj)->GetItem();
	else
		cout << "not yet implemented" << endl;
	
	// get a point which is passing just outside of the occluder
    const Vector3 newPoint = GetPassingPoint(currentRay, occluder, oldRay);
	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);
		//ray.Init(newOrigin, -newDir, Ray::LINE_SEGMENT);
		
		//cout << "z";
		// check if ray intersects view cell
		if (!mCurrentViewCell->CastRay(ray))
			return NULL;

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

	const SimpleRay simpleRay(newOrigin, newDir, SamplingStrategy::GVS, 1.0f);

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

    ++ mGvsStats.mReverseSamples;

	return reverseRay;
}


int GvsPreprocessor::CastInitialSamples(const int numSamples, 
										const int sampleType)
{	
	const long startTime = GetTime();

	// generate simple rays
	SimpleRayContainer simpleRays;
	
	ViewCellBasedDistribution vcStrat(*this, mCurrentViewCell);

    GenerateRays(numSamples, vcStrat, simpleRays);

	//cout << "sr: " << simpleRays.size() << endl;
	// generate vss rays
	VssRayContainer samples;
	
	const bool castDoubleRays = false;
	const bool pruneInvalidRays = true;
	const bool keepOrigin = mPerViewCell;

	CastRays(simpleRays, samples, castDoubleRays, pruneInvalidRays, keepOrigin);
	
	// add to ray queue
	EnqueueRays(samples);

	//Debug << "generated " <<  numSamples << " samples in " << TimeDiff(startTime, GetTime()) * 1e-3 << " secs" << endl;
	return (int)simpleRays.size();
}


void GvsPreprocessor::EnqueueRays(VssRayContainer &samples)
{
	// add samples to ray queue
	VssRayContainer::const_iterator vit, vit_end = samples.end();
	for (vit = samples.begin(); vit != vit_end; ++ vit)
	{
		HandleRay(*vit);
	}
}


int GvsPreprocessor::ProcessQueue()
{
	int castSamples = 0;
	++ mGvsStats.mGvsPass;

	while (!mRayQueue.empty() 
		)//&& (mGvsStats.mTotalSamples + castSamples < mTotalSamples) )
	{
		// handle next ray
		VssRay *ray = mRayQueue.top();
		mRayQueue.pop();
		if (!ray) cout << "Error!!!!!" << endl;
		const int newSamples = AdaptiveBorderSampling(*ray);

		castSamples += newSamples;

		//cout << newSamples << " ";	
		delete ray;
	}

	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(ViewCell *vc)
{
    Intersectable::NewMail();

	Material m;
	
	char str[64]; sprintf(str, "pass%06d.wrl", mNumViewCells);

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

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

	// output PVS of view cell
	while (pit.HasMoreEntries())
	{		
		ObjectPvsEntry entry = pit.Next();

		Intersectable *intersect = entry.mObject;
		
		if (intersect->Mailed())
			continue;
		
		intersect->Mail();
		//m.mDiffuseColor = RgbColor(1, 0, 0);
		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);

	mViewCellsManager->ExportViewCellGeometry(exporter, vc, NULL, NULL);
	//exporter->SetFilled();

	DEL_PTR(exporter);
}


void GvsPreprocessor::VisualizeViewCells()
{
	char str[64]; sprintf(str, "tmp/pass%06d_%04d-", mNumViewCells, 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::ProcessViewCell()
{
	mGvsStats.mPerViewCellSamples = 0;
	int oldContribution = 0;
	int passSamples = 0;

	while (mGvsStats.mPerViewCellSamples < mTotalSamples) 
	{
		// Ray queue empty => 
		// cast a number of uniform samples to fill ray queue
		int newSamples = CastInitialSamples(mInitialSamples, mSamplingType);

		if (!mOnlyRandomSampling)
			newSamples += ProcessQueue();

		passSamples += newSamples;
		mGvsStats.mPerViewCellSamples += newSamples;
	
		if (0 &&
			passSamples % (mSamplesPerPass + 1) == mSamplesPerPass)
		{
			++ mPass;

			mGvsStats.mPassContribution = mGvsStats.mTotalContribution - oldContribution;

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

			mGvsStats.mPass = mPass;
			mGvsStats.Stop();
			mGvsStats.Print(mGvsStatsStream);

			//cout << "\nPass " << mPass << " #samples: " << mGvsStats.mTotalSamples << " of " << mTotalSamples << endl;

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


void GvsPreprocessor::PerViewCellComputation()
{
	const int maxViewCells = 25;
	
	while (mNumViewCells < maxViewCells && NextViewCell())
	{
		cout << "processing view cell " << mNumViewCells << endl;

		// compute the pvs of the current view cell
		ProcessViewCell();

		// exchange triangle pvs with objects
		UpdatePvs(mCurrentViewCell);

		if (GVS_DEBUG)
		{
			VisualizeViewCell(mCurrentViewCell);
			CLEAR_CONTAINER(mVssRays);
		}

		////////
		//-- stats
		
		mGvsStats.mViewCells = mNumViewCells;//mPass;
		mGvsStats.mTotalPvs += mCurrentViewCell->GetPvs().GetSize();
		mGvsStats.mTotalSamples += mGvsStats.mPerViewCellSamples;

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


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

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

	// output PVS of view cell
	while (pit.HasMoreEntries())
	{		
		ObjectPvsEntry entry = pit.Next();

		Intersectable *intersect = entry.mObject;
	
		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::GlobalComputation()
{
	int passSamples = 0;
	int oldContribution = 0;

	while (mGvsStats.mTotalSamples < mTotalSamples) 
	{
		// Ray queue empty => 
		// cast a number of uniform samples to fill ray queue
		int newSamples = CastInitialSamples(mInitialSamples, mSamplingType);

		if (!mOnlyRandomSampling)
			newSamples += ProcessQueue();

		passSamples += newSamples;
		mGvsStats.mTotalSamples += newSamples;

		if (passSamples % (mSamplesPerPass + 1) == mSamplesPerPass)
		{
			++ 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;
	}
	else if (0)
	{	
		//-- test successful view cells loading by exporting them again
		VssRayContainer dummies;
		mViewCellsManager->Visualize(mObjects, dummies);
		mViewCellsManager->ExportViewCells("test.xml.gz", mViewCellsManager->GetExportPvs(), mObjects);
	}

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

	if (mPerViewCell)
	{
		PerViewCellComputation();
	}
	else
	{
		GlobalComputation();
	}

	cout << "cast " << 2 * mGvsStats.mTotalSamples / (1e3f * TimeDiff(startTime, GetTime())) << "M rays/s" << endl;

	if (GVS_DEBUG)
	{
		Visualize();
		CLEAR_CONTAINER(mVssRays);
	}

	return 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 << "#Pass\n" << mPass << endl;
	app << "#Time\n" << Time() << endl;
	app << "#TotalSamples\n" << mTotalSamples << endl;
	app << "#ScDiff\n" << mPassContribution << endl;
	app	<< "#SamplesContri\n" << mTotalContribution << endl;
	app << "#ReverseSamples\n" << mReverseSamples << endl;
	app << "#BorderSamples\n" << mBorderSamples << endl;		
	app << "#GvsRuns\n" << mGvsPass << endl;
	app << "#ViewCells\n" << mViewCells << endl;
	app << "#TotalPvs\n" << mTotalPvs << endl;
	app << "#PerViewCellSamples\n" << mPerViewCellSamples << endl << endl;
}


}