#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"



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

static const float MIN_DIST = 0.001f;

static ObjectContainer myobjects;


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

static vector<VizStruct> vizContainer;




GvsPreprocessor::GvsPreprocessor(): 
Preprocessor(), 
mSamplingType(SamplingStrategy::VIEWCELL_BASED_DISTRIBUTION),
mProcessedViewCells(0),
mCurrentViewCell(NULL),
mCurrentViewPoint(Vector3(0.0f, 0.0f, 0.0f))
{
	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);

	Debug << "Gvs preprocessor options" << endl;
	Debug << "number of total samples: " << mTotalSamples << endl;
	Debug << "number of initial samples: " << mInitialSamples << endl;
	cout << "number of gvs samples per pass: " << mGvsSamplesPerPass << endl;
	cout << "number of samples per pass: " << mSamplesPerPass << 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;

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

	mGvsStats.Reset();

	// hack: some generic statistical values that can be read
	// by an application using the preprocessor
	mGenericStats = 0;
	mGenericStats2 = 0;
}


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


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

		//delete ray;
	}
}


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
	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 1;

		// set flag for visualization
		//newRay->mFlags |= VssRay::ReverseSample;
		
		// check if ray is not further processed (ray not deleted because using ray pool)
		HandleRay(newRay);
		
		return 1;
	}

	return 0;
}


void GvsPreprocessor::CountObject(Intersectable *triObj)
{
	if ((triObj->mCounter != (NOT_ACCOUNTED_OBJECT + 1)) && (triObj->mCounter != (ACCOUNTED_OBJECT + 1)))
	{
		++ triObj->mCounter;
		++ mGenericStats2;
	}
}


void GvsPreprocessor::UpdateStatsForVisualization(KdIntersectable *kdInt)
{
	mViewCellsManager->UpdateStatsForViewCell(mCurrentViewCell, kdInt);

	// count new objects in pvs due to kd node conversion	
	myobjects.clear();
	mKdTree->CollectObjects(kdInt->GetItem(), myobjects);

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

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


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

	bool result;

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

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

		result = ray.mPvsContribution > 0;
	}
	else // original per view cell gvs
	{
		Intersectable *obj = ray.mTerminationObject;

		// counter < 2 => not accounted for yet
		if (obj->mCounter < ACCOUNTED_OBJECT)
		{
			obj->mCounter += ACCOUNTED_OBJECT;
			mTrianglePvs.push_back(obj);
		
			mGenericStats = mTrianglePvs.size();

			// exchange the triangle with the node in the pvs for kd pvs
			if (mUseKdPvs)
			{
				KdNode *node = mKdTree->GetPvsNode(ray.mTermination);

				if (!node->Mailed())
				{
					// add to pvs
					node->Mail();
					KdIntersectable *kdInt = mKdTree->GetOrCreateKdIntersectable(node);
					mCurrentViewCell->GetPvs().AddSampleDirty(kdInt, 1.0f);
				
					if (SHOW_QT_VISUALIZATION) UpdateStatsForVisualization(kdInt);	
				}
			}

			result = true;
		}
		else
		{
			result = false;
		}
	}

	return result;
}


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

//	cout << "t";
	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;
	// 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);
	
	++ castRays;

	if (!newRay) return castRays;

	//newRay->mFlags |= VssRay::BorderSample;

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

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

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

	return castRays;
}


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

	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 = !mPerViewCell;
	// cannot prune invalid rays because we have to compare adjacent  rays.
	const bool pruneInvalidRays = false;


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

	//const int numRandomRays = 0;
	const int numRandomRays = 16 - (int)simpleRays.size();
	ViewCellBasedDistribution vcStrat(*this, mCurrentViewCell);

	GenerateRays(numRandomRays, vcStrat, simpleRays);


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

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

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

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

	int castRays = (int)simpleRays.size();

	VssRayContainer invalidSamples;

	// handle rays
	EnqueueRays(vssRays, invalidSamples);

    // 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;

	//CLEAR_CONTAINER(invalidSamples);
	
	//cout << "cast rays: " << castRays << endl;
	return castRays;
}


bool GvsPreprocessor::GetPassingPoint(const VssRay &currentRay,
									  const Triangle3 &occluder,
									  const VssRay &oldRay,
									  Vector3 &newPoint) 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 " << pt1 << " " << pt2 << endl;
		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
	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 true;
}


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 = 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;

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

	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);
		
		//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 = !mPerViewCell;
	const bool pruneInvalidRays = true;
	
	CastRays(simpleRays, samples, castDoubleRays, pruneInvalidRays);
	
	VssRayContainer invalidSamples;

	// add to ray queue
	EnqueueRays(samples, invalidSamples);

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


void GvsPreprocessor::EnqueueRays(VssRayContainer &samples, VssRayContainer &invalidSamples)
{
	// 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);
		//if (!HandleRay(ray)) invalidSamples.push_back(ray);
	}
}


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

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

		castSamples += newSamples;
		//delete ray;
	}

	/*if (mRayCaster->mVssRayPool.mIndex > mSamplesPerPass)
	{
		cout << "warning: new samples: " << castSamples << " " << "queue: "  << (int)mRayQueue.size() << endl;
		Debug << "warning: new samples: " << castSamples << " " << "queue: "  << (int)mRayQueue.size() << endl;
	}*/

	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(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);

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

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

	delete exporter;
}


void GvsPreprocessor::VisualizeViewCells()
{
	char str[64]; sprintf(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::ProcessViewCell()
{
	// compute object that directly intersect view cell
	IntersectWithViewCell();

	mGvsStats.mPerViewCellSamples = 0;

	int oldContribution = mGvsStats.mTotalContribution;
	int passSamples = 0;

	mGenericStats = 0;
	mGenericStats2 = 0;

	//while (mGvsStats.mPerViewCellSamples < mTotalSamples) 
	while (1)
	{
		mRayCaster->InitPass();

		// 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 (passSamples >= mGvsSamplesPerPass)
		{
			++ mPass;
			mGvsStats.mPassContribution = mGvsStats.mTotalContribution - oldContribution;

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

			mGvsStats.mPass = mPass;

			cout << "\nPass " << mPass << " #samples: " << mGvsStats.mPerViewCellSamples << endl;
			cout << "contribution=" << mGvsStats.mPassContribution << " (of " << mMinContribution << ")" << endl;

			//mGenericStats = mGvsStats.mPassContribution;

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

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


void GvsPreprocessor::CompileViewCellsList()
{
	// Receive list of view cells from view cells manager
	ViewCellPointsList *vcPoints = mViewCellsManager->GetViewCellPointsList();
	
	if (!vcPoints->empty())
	{
		cout << "processing view cell list" << endl;
		
		vector<ViewCellPoints *>::const_iterator vit, vit_end = vcPoints->end();

		for (vit = vcPoints->begin(); vit != vit_end; ++ vit)
		{
			mViewCells.push_back((*vit)->first);

			if (mViewCells.size() >= mMaxViewCells)
				break;
		}
	}
	else
	{
		while ((int)mViewCells.size() < mMaxViewCells)
		{
			if (0)
			{
				mViewCells.push_back(mViewCellsManager->GetViewCell((int)mViewCells.size()));
				continue;
			}

			// HACK
			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::IntersectWithViewCell()
{
	mCurrentViewCell->GetMesh()->ComputeBoundingBox();
	AxisAlignedBox3 box = mCurrentViewCell->GetMesh()->mBox;
	
	//vector<KdLeaf *> leaves;
	//mKdTree->GetBoxIntersections(box, leaves);

	ObjectContainer kdobjects;
	mKdTree->CollectKdObjects(box, kdobjects);

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

	for (oit = kdobjects.begin(); oit != oit_end; ++ oit)
	{
       	// add to kdnode pvs
		KdIntersectable *kdInt = static_cast<KdIntersectable *>(*oit);
		
		//mCurrentViewCell->GetPvs().AddSampleDirty(kdInt, 1.0f);
		mCurrentViewCell->GetPvs().AddSampleDirtyCheck(kdInt, 1.0f);

		mViewCellsManager->UpdateStatsForViewCell(mCurrentViewCell, kdInt);

		myobjects.clear();
		mKdTree->CollectObjects(kdInt->GetItem(), myobjects);

		// account for kd object pvs
		ObjectContainer::const_iterator oit, oit_end = myobjects.end();

		for (oit = myobjects.begin(); oit != oit_end; ++ oit)
		{
			TriangleIntersectable *triObj = static_cast<TriangleIntersectable *>(*oit);
            
			CountObject(triObj);
            
			// the triangle itself intersects
			if (box.Intersects(triObj->GetItem()))
			{
				if ((triObj->mCounter < ACCOUNTED_OBJECT))
				{
					triObj->mCounter += ACCOUNTED_OBJECT;

					mTrianglePvs.push_back(triObj);
					mGenericStats = mTrianglePvs.size();
				}
			}			
		}
	}
}


void GvsPreprocessor::PerViewCellComputation()
{
	ViewCell *vc;

	while (vc = NextViewCell())
	{
		// 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(vc);
		// $$ JB HACK compute just first viewcell
		//		break;
	}
}


void GvsPreprocessor::PerViewCellComputation2()
{
	ViewCell *vc;

	while (1)
	{
		if (!mRendererWidget)
			continue;

        ViewCell *vc = mViewCellsManager->GetViewCell(mRendererWidget->GetViewPoint());

		// no valid view cell or view cell already computed
		if (!vc || !vc->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(vc);
		++ 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
{
	objectPvs.reserve((int)mTrianglePvs.size());

	BvhLeaf::NewMail();

	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 oldContribution = 0;

	while (mGvsStats.mTotalSamples < mTotalSamples) 
	{
		mRayCaster->InitPass();
		// 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 % (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 " << 2 * mGvsStats.mTotalSamples / (1e3f * TimeDiff(startTime, GetTime())) << "M 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 (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 << "#TrianglePvs\n" << mTrianglePvs << endl;
	app << "#ObjectPvs\n" << mPerViewCellPvs << endl;
	app << "#PvsCost\n" << (int)mPvsCost << endl;

#if 0
	app << "#TotalPvs\n" << mTotalPvs << endl;
	app << "#TotalTime\n" << mTotalTime << endl;
	app << "#RaysPerSec\n" << RaysPerSec() << endl;
	
	app << "#PerViewCellSamples\n" << mPerViewCellSamples << endl;
	app << "#TotalSamples\n" << mTotalSamples << endl;
	app	<< "#SamplesContri\n" << mTotalContribution << endl;
	app << "#TotalTrianglePvs\n" << mTotalTrianglePvs << endl;
	
#endif

	//app << "#ReverseSamples\n" << mReverseSamples << endl;
	//app << "#BorderSamples\n" << mBorderSamples << endl;

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

	app << endl;
}


void GvsPreprocessor::ComputeViewCell(ViewCell *vc)
{
	KdNode::NewMail();

	mCurrentViewCell = vc;
	
	const long startTime = GetTime();

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

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

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

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

		cout << "id: " << mCurrentViewCell->GetId() << " pvs cost: " 
			 << mGvsStats.mPvsCost << " pvs tri: " << mTrianglePvs.size() << endl;
	}


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

	mGvsStats.mViewCells = mProcessedViewCells;//mPass;
	mGvsStats.mTotalPvs += mGvsStats.mPerViewCellPvs;
	mGvsStats.mTotalSamples += mGvsStats.mPerViewCellSamples;

	// timing
	const long currentTime = GetTime();

	mGvsStats.mTimePerViewCell = TimeDiff(startTime, currentTime) * 1e-3f;
	mGvsStats.mTotalTime += mGvsStats.mTimePerViewCell;

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

	mTrianglePvs.clear();
}

}