#include "SceneGraph.h"
#include "Exporter.h"
#include "UnigraphicsParser.h"
#include "X3dParser.h"
#include "Preprocessor.h"
#include "ViewCell.h"
#include "Environment.h"
#include "ViewCellsManager.h"
#include "ViewCellBsp.h"
#include "VspBspTree.h"
#include "RenderSimulator.h"
#include "GlRenderer.h"
#include "PlyParser.h"
#include "SamplingStrategy.h"
#include "VspTree.h"
#include "OspTree.h"
#include "ObjParser.h"
#include "BvHierarchy.h"
#include "HierarchyManager.h"
#include "VssRay.h"
#include "IntelRayCaster.h"
#include "InternalRayCaster.h"



#define DEBUG_RAYCAST 0


namespace GtpVisibilityPreprocessor {

const static bool ADDITIONAL_GEOMETRY_HACK = false;


// HACK: Artificially modify scene to watch rendercost changes
static void AddGeometry(SceneGraph *scene)
{
	scene->GetRoot()->UpdateBox();

	AxisAlignedBox3 sceneBox = scene->GetBox();

	int n = 200;

	if (0)
	{
		// form grid of boxes
		for (int i = 0; i < n; ++ i)
		{
			for (int j = 0; j < n; ++ j)
			{
				const Vector3 scale2((float)j * 0.8f / n + 0.1f,  0.05f, (float)i * 0.8f  / (float)n + 0.1f);

				const Vector3 pt2 = sceneBox.Min() + scale2 * (sceneBox.Max() - sceneBox.Min());

				const Vector3 boxSize = sceneBox.Size() * Vector3(0.0025f, 0.01f, 0.0025f);
				AxisAlignedBox3 box(pt2, pt2 + boxSize);
				Mesh *mesh = CreateMeshFromBox(box);

				mesh->Preprocess();

				MeshInstance *mi = new MeshInstance(mesh);
				scene->GetRoot()->mGeometry.push_back(mi);
			}
		}

		for (int i = 0; i < n; ++ i)
		{
			for (int j = 0; j < n; ++ j)
			{
				const Vector3 scale2(0.15f, (float)j * 0.8f / n + 0.1f, (float)i * 0.8f  / (float)n + 0.1f);

				Vector3 pt2 = sceneBox.Min() + scale2 * (sceneBox.Max() - sceneBox.Min());

				Vector3 boxSize = sceneBox.Size() * Vector3(0.0025f, 0.01f, 0.0025f);
				AxisAlignedBox3 box(pt2, pt2 + boxSize);
				Mesh *mesh = CreateMeshFromBox(box);

				mesh->Preprocess();

				MeshInstance *mi = new MeshInstance(mesh);
				scene->GetRoot()->mGeometry.push_back(mi);
			}
		}

		for (int i = 0; i < n; ++ i)
		{
			const Vector3 scale2(2, 0.2f, (float)i * 0.8f  / (float)n + 0.1f);

			Vector3 pt2 = sceneBox.Min() + scale2 * (sceneBox.Max() - sceneBox.Min());

			//Vector3 boxSize = sceneBox.Size() * Vector3(0.0025, 0.01, 0.0025);
			Vector3 boxSize = sceneBox.Size() * Vector3(0.005f, 0.02f, 0.005f);

			AxisAlignedBox3 box(pt2 + 0.1f, pt2 + boxSize);
			Mesh *mesh = CreateMeshFromBox(box);

			mesh->Preprocess();

			MeshInstance *mi = new MeshInstance(mesh);
			scene->GetRoot()->mGeometry.push_back(mi);
		}

		scene->GetRoot()->UpdateBox();
	}

	if (1)
	{
		// plane separating view space regions
		const Vector3 scale(1.0f, 0.0, 0);

		Vector3 pt = sceneBox.Min() + scale * (sceneBox.Max() - sceneBox.Min());

		Plane3 cuttingPlane(Vector3(1, 0, 0), pt);
		Mesh *planeMesh = new Mesh();

		Polygon3 *poly = sceneBox.CrossSection(cuttingPlane);
		IncludePolyInMesh(*poly, *planeMesh);

		planeMesh->Preprocess();

		MeshInstance *planeMi = new MeshInstance(planeMesh);
		scene->GetRoot()->mGeometry.push_back(planeMi);
	}	
}


Preprocessor::Preprocessor():
mKdTree(NULL),
mBspTree(NULL),
mVspBspTree(NULL),
mHierarchyManager(NULL),
mViewCellsManager(NULL),
mRenderSimulator(NULL),
mPass(0),
mSceneGraph(NULL),
mRayCaster(NULL)
{
	Environment::GetSingleton()->GetBoolValue("Preprocessor.useGlRenderer", mUseGlRenderer);
  
	// renderer will be constructed when the scene graph and viewcell manager will be known
	renderer = NULL;
  
	Environment::GetSingleton()->GetBoolValue("Preprocessor.useGlDebugger", mUseGlDebugger);
	Environment::GetSingleton()->GetBoolValue("Preprocessor.loadMeshes", mLoadMeshes);
	Environment::GetSingleton()->GetBoolValue("Preprocessor.quitOnFinish", mQuitOnFinish);
	Environment::GetSingleton()->GetBoolValue("Preprocessor.computeVisibility", mComputeVisibility);
	Environment::GetSingleton()->GetBoolValue("Preprocessor.detectEmptyViewSpace", mDetectEmptyViewSpace);
	Environment::GetSingleton()->GetBoolValue("Preprocessor.exportVisibility", mExportVisibility );
	
	char buffer[256];
	Environment::GetSingleton()->GetStringValue("Preprocessor.visibilityFile",  buffer);
    
	mVisibilityFileName = buffer;
	Environment::GetSingleton()->GetBoolValue("Preprocessor.applyVisibilityFilter", mApplyVisibilityFilter );
	Environment::GetSingleton()->GetBoolValue("Preprocessor.applyVisibilitySpatialFilter",
							  mApplyVisibilitySpatialFilter );
	Environment::GetSingleton()->GetFloatValue("Preprocessor.visibilityFilterWidth", mVisibilityFilterWidth);

	Debug << "detect empty view space=" << mDetectEmptyViewSpace << endl;
	Debug << "load meshes: " << mLoadMeshes << endl;
}


Preprocessor::~Preprocessor()
{
	cout << "cleaning up" << endl;

	cout << "Deleting view cells manager ... \n";
	DEL_PTR(mViewCellsManager);
	cout << "done.\n";

	cout << "Deleting bsp tree ... \n";
	DEL_PTR(mBspTree);
	cout << "done.\n";

	cout << "Deleting kd tree...\n";
	DEL_PTR(mKdTree);
	cout << "done.\n";

	cout << "Deleting hierarchy manager...\n";
	DEL_PTR(mHierarchyManager);
	cout << "done.\n";

	cout << "Deleting vspbsp tree...\n";
	DEL_PTR(mVspBspTree);
	cout << "done.\n";

	cout << "Deleting scene graph...\n";
	DEL_PTR(mSceneGraph);
	cout << "done.\n";

	DEL_PTR(mRenderSimulator);
	DEL_PTR(renderer);
	DEL_PTR(mRayCaster);
}


GlRendererBuffer *Preprocessor::GetRenderer() 
{ 
	return renderer;
}


static int SplitFilenames(const string str, vector<string> &filenames)
{
	int pos = 0;

	while(1) {
		int npos = (int)str.find(';', pos);
		
		if (npos < 0 || npos - pos < 1)
			break;
		filenames.push_back(string(str, pos, npos - pos));
		pos = npos + 1;
	}
	
	filenames.push_back(string(str, pos, str.size() - pos));
	return (int)filenames.size();
}


bool
Preprocessor::LoadScene(const string filename)
{
	// use leaf nodes of the original spatial hierarchy as occludees
	mSceneGraph = new SceneGraph;
  
	Parser *parser;
	vector<string> filenames;
	const int files = SplitFilenames(filename, filenames);
	cout << "number of input files: " << files << endl;
	bool result = false;

	// root for different files
	mSceneGraph->SetRoot(new SceneGraphNode());

	// intel ray caster can only trace triangles
	int rayCastMethod;
	Environment::GetSingleton()->GetIntValue("Preprocessor.rayCastMethod", rayCastMethod);
	vector<FaceParentInfo> *fi = (rayCastMethod == RayCaster::INTEL_RAYCASTER) ?
		&mFaceParents : NULL;

	if (files == 1) {
		
		if (strstr(filename.c_str(), ".x3d"))
		  parser = new X3dParser;
		else
		  if (strstr(filename.c_str(), ".ply") || strstr(filename.c_str(), ".plb"))
			parser = new PlyParser;
		  else if (strstr(filename.c_str(), ".obj"))
			  parser = new ObjParser;
		  else 
			  parser = new UnigraphicsParser;

		cout << filename << endl;
		
		result = parser->ParseFile(
				filename, 
				mSceneGraph->GetRoot(),
				mLoadMeshes,
				fi);
			
		delete parser;

	} 
	else {
		vector<string>::const_iterator fit, fit_end = filenames.end();
		
		for (fit = filenames.begin(); fit != fit_end; ++ fit) 
		{
			const string filename = *fit;

			cout << "parsing file " << filename.c_str() << endl;
			if (strstr(filename.c_str(), ".x3d"))
				parser = new X3dParser;
			else 
				parser = new UnigraphicsParser;

			SceneGraphNode *node = new SceneGraphNode();
			const bool success = parser->ParseFile(
				filename, 
				node,
				mLoadMeshes,
				fi);

			if (success) 
			{ 
				mSceneGraph->GetRoot()->mChildren.push_back(node);
				result = true; // at least one file parsed
			}

			delete parser;
		}
	}
	
	if (result) 
	{ 
		// HACK 
		if (ADDITIONAL_GEOMETRY_HACK)
			AddGeometry(mSceneGraph);

		mSceneGraph->AssignObjectIds();
 
		int intersectables, faces;
		mSceneGraph->GetStatistics(intersectables, faces);
 
		cout<<filename<<" parsed successfully."<<endl;
		cout<<"#NUM_OBJECTS (Total numner of objects)\n"<<intersectables<<endl;
		cout<<"#NUM_FACES (Total numner of faces)\n"<<faces<<endl;
		mSceneGraph->CollectObjects(&mObjects);
		mSceneGraph->GetRoot()->UpdateBox();
 
		if (0)
		{
			Exporter *exporter = Exporter::GetExporter("testload.x3d");
			if (exporter)
			{
				exporter->ExportGeometry(mObjects);
				delete exporter;
			}
		}
	}

	return result;
}

bool
Preprocessor::ExportPreprocessedData(const string filename)
{
	mViewCellsManager->ExportViewCells(filename, true, mObjects);
	return true;
}


bool
Preprocessor::PostProcessVisibility()
{
  
  if (mApplyVisibilityFilter || mApplyVisibilitySpatialFilter) {
	cout<<"Applying visibility filter ...";
	cout<<"filter width = " << mVisibilityFilterWidth << endl;
	
	if (!mViewCellsManager)
	  return false;
	
	mViewCellsManager->ApplyFilter(mKdTree,
								   mApplyVisibilityFilter ? mVisibilityFilterWidth : -1.0f,
								   mApplyVisibilitySpatialFilter ? mVisibilityFilterWidth : -1.0f);
	cout << "done." << endl;
  }
  
  // export the preprocessed information to a file
  if (mExportVisibility)
  {
	  ExportPreprocessedData(mVisibilityFileName);
  }

  return true;
}


bool
Preprocessor::BuildKdTree()
{
  mKdTree = new KdTree;

  // add mesh instances of the scene graph to the root of the tree
  KdLeaf *root = (KdLeaf *)mKdTree->GetRoot();
 	
  mSceneGraph->CollectObjects(&root->mObjects);
  
  const long startTime = GetTime();
  cout << "building kd tree ... " << endl;

  mKdTree->Construct();

  cout << "finished kd tree construction in " << TimeDiff(startTime, GetTime()) * 1e-3 
	   << " secs " << endl;

  return true;
}


void
Preprocessor::KdTreeStatistics(ostream &s)
{
  s<<mKdTree->GetStatistics();
}

void
Preprocessor::BspTreeStatistics(ostream &s)
{
	s << mBspTree->GetStatistics();
}

bool
Preprocessor::Export( const string filename,
					  const bool scene,
					  const bool kdtree
					  )
{
  Exporter *exporter = Exporter::GetExporter(filename);
	
  if (exporter) {
    if (2 && scene)
      exporter->ExportScene(mSceneGraph->GetRoot());

    if (1 && kdtree) {
      exporter->SetWireframe();
      exporter->ExportKdTree(*mKdTree);
    }

    delete exporter;
    return true;
  }

  return false;
}


bool Preprocessor::PrepareViewCells()
{
	///////
	//-- parse view cells construction method

	Environment::GetSingleton()->GetBoolValue("ViewCells.loadFromFile", mLoadViewCells);
	char buf[100];
	
	if (mLoadViewCells)
	{	
	  Environment::GetSingleton()->GetStringValue("ViewCells.filename", buf);
	  cout << "loading view cells from " << buf << endl;
	  
	  mViewCellsManager = ViewCellsManager::LoadViewCells(buf, &mObjects, true);
	  
	  if (!mViewCellsManager)
		return false;
	}
	else
	{
		// parse type of view cell container
		Environment::GetSingleton()->GetStringValue("ViewCells.type", buf);		
	    mViewCellsManager = CreateViewCellsManager(buf);

		// default view space is the extent of the scene
		AxisAlignedBox3 box = mSceneGraph->GetBox();
					
		if (0)
		{
			// use a small box outside of the scene
			box.Scale(Vector3(0.1f,0.5f,0.5f));
			box.Translate(Vector3(Magnitude(mSceneGraph->GetBox().Size())*0.5f, 0, 0));
		}

		mViewCellsManager->SetViewSpaceBox(box);
	 
		bool loadVcGeometry;
		Environment::GetSingleton()->GetBoolValue("ViewCells.loadGeometry", loadVcGeometry);

		bool extrudeBaseTriangles;
		Environment::GetSingleton()->GetBoolValue("ViewCells.useBaseTrianglesAsGeometry", extrudeBaseTriangles);

		char vcGeomFilename[100];
		Environment::GetSingleton()->GetStringValue("ViewCells.geometryFilename", vcGeomFilename);
		
		if (mViewCellsManager->GetType() == ViewCellsManager::BSP)
		{
			if (!mViewCellsManager->LoadViewCellsGeometry(vcGeomFilename, extrudeBaseTriangles))
			{
				cerr << "loading view cells geometry failed" << endl;
			}
		}
		else
		{
			cerr << "loading view cells geometry is not implemented for this manager" << endl;
		}
	}
	
	////////
	//-- evaluation of render cost heuristics
	float objRenderCost = 0, vcOverhead = 0, moveSpeed = 0;

	Environment::GetSingleton()->GetFloatValue("Simulation.objRenderCost",objRenderCost);
	Environment::GetSingleton()->GetFloatValue("Simulation.vcOverhead", vcOverhead);
	Environment::GetSingleton()->GetFloatValue("Simulation.moveSpeed", moveSpeed);
	
	mRenderSimulator = 
		new RenderSimulator(mViewCellsManager, objRenderCost, vcOverhead, moveSpeed);

	mViewCellsManager->SetRenderer(mRenderSimulator);
	
	if (mUseGlRenderer || mUseGlDebugger)
	  {
		// NOTE: render texture should be power of 2 and square
		// renderer must be initialised
		// $$matt
		//		renderer = new GlRendererBuffer(1024, 768, mSceneGraph, mViewCellsManager, mKdTree);
		//		renderer->makeCurrent();
		
	  }

	mViewCellsManager->SetPreprocessor(this);
	return true;
}

  
bool Preprocessor::ConstructViewCells()
{
  // construct view cells using it's own set of samples
  mViewCellsManager->Construct(this);
  
  // visualizations and statistics
  Debug << "finished view cells:" << endl;
  mViewCellsManager->PrintStatistics(Debug);
  
  return true;
}


HierarchyManager *Preprocessor::CreateHierarchyManager(const char *name)
{
	HierarchyManager *hierarchyManager;

	if (strcmp(name, "osp") == 0)
	{
		Debug << "hierarchy manager: osp" << endl;
		// HACK for testing if per kd evaluation works!!
		const bool ishack = false;
		if (ishack)
			hierarchyManager = new HierarchyManager(mKdTree);
		else
			hierarchyManager = new HierarchyManager(HierarchyManager::KD_BASED_OBJ_SUBDIV);
	}
	else if (strcmp(name, "bvh") == 0)
	{
		Debug << "hierarchy manager: bvh" << endl;
		hierarchyManager = new HierarchyManager(HierarchyManager::BV_BASED_OBJ_SUBDIV);
	}
	else // only view space partition
	{
		Debug << "hierarchy manager: obj" << endl;
		hierarchyManager = new HierarchyManager(HierarchyManager::NO_OBJ_SUBDIV);
	}

	return hierarchyManager;
}


ViewCellsManager *Preprocessor::CreateViewCellsManager(const char *name)
{
	ViewCellsTree *vcTree = new ViewCellsTree;

	if (strcmp(name, "kdTree") == 0)
	{
		mViewCellsManager = new KdViewCellsManager(vcTree, mKdTree);
	}
	else if (strcmp(name, "bspTree") == 0)
	{
		Debug << "view cell type: Bsp" << endl;

		mBspTree = new BspTree();
		mViewCellsManager = new BspViewCellsManager(vcTree, mBspTree);
	}
	else if (strcmp(name, "vspBspTree") == 0)
	{
		Debug << "view cell type: VspBsp" << endl;

		mVspBspTree = new VspBspTree();
		mViewCellsManager = new VspBspViewCellsManager(vcTree, mVspBspTree);
	}
	else if (strcmp(name, "vspOspTree") == 0)
	{
		Debug << "view cell type: VspOsp" << endl;
		char buf[100];		
		Environment::GetSingleton()->GetStringValue("Hierarchy.type", buf);	

		HierarchyManager *mHierarchyManager = CreateHierarchyManager(buf);
		mViewCellsManager = new VspOspViewCellsManager(vcTree, mHierarchyManager);
	}
	else if (strcmp(name, "sceneDependent") == 0) //TODO
	{
		Debug << "view cell type: Bsp" << endl;
		
		mBspTree = new BspTree();
		mViewCellsManager = new BspViewCellsManager(vcTree, mBspTree);
	}
	else
	{
		cerr << "Wrong view cells type " << name << "!!!" << endl;
		exit(1);
	}

	return mViewCellsManager;
}


// use ascii format to store rays
#define USE_ASCII 0


static inline bool ilt(Intersectable *obj1, Intersectable *obj2)
{
	return obj1->mId < obj2->mId;
}


bool Preprocessor::LoadKdTree(const string filename)
{
	mKdTree = new KdTree();
	return mKdTree->LoadBinTree(filename.c_str(), mObjects);
}


bool Preprocessor::ExportKdTree(const string filename)
{
	return mKdTree->ExportBinTree(filename.c_str());
}


bool Preprocessor::LoadSamples(VssRayContainer &samples, 
							   ObjectContainer &objects) const
{
	std::stable_sort(objects.begin(), objects.end(), ilt);
	char fileName[100];
	Environment::GetSingleton()->GetStringValue("Preprocessor.samplesFilename", fileName);
	
    Vector3 origin, termination;
	// HACK: needed only for lower_bound algorithm to find the 
	// intersected objects
	MeshInstance sObj(NULL);
	MeshInstance tObj(NULL);

#if USE_ASCII
	ifstream samplesIn(fileName);
	if (!samplesIn.is_open())
		return false;

	string buf;
	while (!(getline(samplesIn, buf)).eof())
	{
		sscanf(buf.c_str(), "%f %f %f %f %f %f %d %d", 
			   &origin.x, &origin.y, &origin.z,
			   &termination.x, &termination.y, &termination.z, 
			   &(sObj.mId), &(tObj.mId));
		
		Intersectable *sourceObj = NULL;
		Intersectable *termObj = NULL;
		
		if (sObj.mId >= 0)
		{
			ObjectContainer::iterator oit =
				lower_bound(objects.begin(), objects.end(), &sObj, ilt);
			sourceObj = *oit;
		}
		
		if (tObj.mId >= 0)
		{
			ObjectContainer::iterator oit =
				lower_bound(objects.begin(), objects.end(), &tObj, ilt);
			termObj = *oit;
		}

		samples.push_back(new VssRay(origin, termination, sourceObj, termObj));
	}
#else
	ifstream samplesIn(fileName, ios::binary);
	if (!samplesIn.is_open())
		return false;

	while (1)
	{
		 samplesIn.read(reinterpret_cast<char *>(&origin), sizeof(Vector3));
		 samplesIn.read(reinterpret_cast<char *>(&termination), sizeof(Vector3));
		 samplesIn.read(reinterpret_cast<char *>(&(sObj.mId)), sizeof(int));
		 samplesIn.read(reinterpret_cast<char *>(&(tObj.mId)), sizeof(int));
		
		 if (samplesIn.eof())
			break;

		Intersectable *sourceObj = NULL;
		Intersectable *termObj = NULL;
		
		if (sObj.mId >= 0)
		{
			ObjectContainer::iterator oit =
				lower_bound(objects.begin(), objects.end(), &sObj, ilt);
			sourceObj = *oit;
		}
		
		if (tObj.mId >= 0)
		{
			ObjectContainer::iterator oit =
				lower_bound(objects.begin(), objects.end(), &tObj, ilt);
			termObj = *oit;
		}

		samples.push_back(new VssRay(origin, termination, sourceObj, termObj));
	}

#endif
	samplesIn.close();

	return true;
}


bool Preprocessor::ExportSamples(const VssRayContainer &samples) const
{
	char fileName[100];
	Environment::GetSingleton()->GetStringValue("Preprocessor.samplesFilename", fileName);
	

	VssRayContainer::const_iterator it, it_end = samples.end();
	
#if USE_ASCII
	ofstream samplesOut(fileName);
	if (!samplesOut.is_open())
		return false;

	for (it = samples.begin(); it != it_end; ++ it)
	{
		VssRay *ray = *it;
		int sourceid = ray->mOriginObject ? ray->mOriginObject->mId : -1;		
		int termid = ray->mTerminationObject ? ray->mTerminationObject->mId : -1;	

		samplesOut << ray->GetOrigin().x << " " << ray->GetOrigin().y << " " << ray->GetOrigin().z << " " 
				   << ray->GetTermination().x << " " << ray->GetTermination().y << " " << ray->GetTermination().z << " " 
				   << sourceid << " " << termid << "\n";
	}
#else
	ofstream samplesOut(fileName, ios::binary);
	if (!samplesOut.is_open())
		return false;

	for (it = samples.begin(); it != it_end; ++ it)
	{	
		VssRay *ray = *it;
		Vector3 origin(ray->GetOrigin());
		Vector3 termination(ray->GetTermination());
		
		int sourceid = ray->mOriginObject ? ray->mOriginObject->mId : -1;		
		int termid = ray->mTerminationObject ? ray->mTerminationObject->mId : -1;		

		samplesOut.write(reinterpret_cast<char *>(&origin), sizeof(Vector3));
		samplesOut.write(reinterpret_cast<char *>(&termination), sizeof(Vector3));
		samplesOut.write(reinterpret_cast<char *>(&sourceid), sizeof(int));
		samplesOut.write(reinterpret_cast<char *>(&termid), sizeof(int));
    }
#endif
	samplesOut.close();

	return true;
}

bool Preprocessor::GenerateRays(const int number,
								const int sampleType,
								SimpleRayContainer &rays)
{
	const int startSize = (int)rays.size();
	SamplingStrategy *strategy = GenerateSamplingStrategy(sampleType);

	if (!strategy)
	{
		return false;
	}

	for (int i=0; (int)rays.size() - startSize < number; ++ i) 
	{
		SimpleRay newRay;

		if (strategy->GenerateSample(newRay))
		{
#if 1
			rays.AddRay(newRay);
#else
			GenerateRayBundle(rays, newRay, 16, 0);
#endif
		}	
	}

	delete strategy;
    return true;
}


SamplingStrategy *Preprocessor::GenerateSamplingStrategy(const int strategyId) const
{
	switch (strategyId)
	{
	case SamplingStrategy::OBJECT_BASED_DISTRIBUTION: 
		return new ObjectBasedDistribution(*this);
	case SamplingStrategy::OBJECT_DIRECTION_BASED_DISTRIBUTION:
		return new ObjectDirectionBasedDistribution(*this);
	case SamplingStrategy::DIRECTION_BASED_DISTRIBUTION:
		return new DirectionBasedDistribution(*this);
	case SamplingStrategy::DIRECTION_BOX_BASED_DISTRIBUTION: 
		return new DirectionBoxBasedDistribution(*this);
	case SamplingStrategy::SPATIAL_BOX_BASED_DISTRIBUTION:
		return new SpatialBoxBasedDistribution(*this);
	//case OBJECTS_INTERIOR_DISTRIBUTION:
	//	return new ObjectsInteriorDistribution(*this);
	default: // no valid strategy
		Debug << "warning: no valid sampling strategy" << endl;
		return NULL;
	}

	return NULL; // should never come here
}


bool Preprocessor::InitRayCast(const string externKdTree, const string internkdtree)
{
	bool loadKdTree;
	Environment::GetSingleton()->GetBoolValue("Preprocessor.loadKdTree", loadKdTree);
	
	if (!loadKdTree)
	{	
		//-- build new kd tree from scene geometry
		BuildKdTree();
		KdTreeStatistics(cout);
	}
	else
	{
		const long startTime = GetTime();
		cout << "loading kd tree file " << internkdtree << " ... ";

		if (!LoadKdTree(internkdtree))
		{
			cout << "error loading kd tree with filename " << internkdtree << ", rebuilding it instead ..." << endl;

			BuildKdTree();
			KdTreeStatistics(cout);
		}

		cout << "finished in " << TimeDiff(startTime, GetTime()) * 1e-3 << " secs" << endl;

		if (0)
		{
			Exporter *exporter = Exporter::GetExporter("dummykd.x3d");
			
			if (exporter)
			{
				exporter->ExportKdTree(*mKdTree, true);
				delete exporter;
			}
		}
	}

	int rayCastMethod;
	Environment::GetSingleton()->GetIntValue("Preprocessor.rayCastMethod", rayCastMethod);

	if (rayCastMethod == 0)
	{
		mRayCaster = new InternalRayCaster(*this, mKdTree);
		cout << "ray cast method: internal" << endl;
	}
	else
	{
#ifdef GTP_INTERNAL
		mRayCaster = new IntelRayCaster(*this, externKdTree);
		cout << "ray cast method: intel" << endl;
#endif
	}

	return true;
}


void
Preprocessor::CastRays(
					   SimpleRayContainer &rays,
					   VssRayContainer &vssRays,
					   const bool castDoubleRays,
					   const bool pruneInvalidRays
					   )
{
	const long t1 = GetTime();

	for (int i = 0; i < (int)rays.size();)
	{
		if (i + 16 < (int)rays.size()) 
		{
			mRayCaster->CastRays16(
				i,
				rays,				
				vssRays,
				mViewCellsManager->GetViewSpaceBox(),
				castDoubleRays,
				pruneInvalidRays);
			i += 16;
		}
		else 
		{
			mRayCaster->CastRay(
				rays[i],
				vssRays,
				mViewCellsManager->GetViewSpaceBox(),
				castDoubleRays,
				pruneInvalidRays);
			i ++;
		}
	}

	if (i % 10000 == 0)
		cout<<".";

#if DEBUB_RAYCAST
	long t2 = GetTime();
	if (castDoubleRays)
		cout << 2 * rays.size() / (1e3f * TimeDiff(t1, t2)) << "M rays/s" << endl;
	else
		cout << rays.size() / (1e3f * TimeDiff(t1, t2)) << "M rays/s" << endl;
#endif	
}


bool Preprocessor::GenerateRayBundle(SimpleRayContainer &rayBundle,									
									 const SimpleRay &mainRay,
									 const int number,
									 const int pertubType) const
{
	rayBundle.push_back(mainRay);

	const float pertubOrigin = 0.0f;
	const float pertubDir = 0.2f;

	for (int i = 0; i < number - 1; ++ i)
	{
		Vector3 pertub;

		pertub.x = RandomValue(0.0f, pertubDir);
		pertub.y = RandomValue(0.0f, pertubDir);
		pertub.z = RandomValue(0.0f, pertubDir);
		const Vector3 newDir = mainRay.mDirection + pertub;
		//const Vector3 newDir = mainRay.mDirection;

		pertub.x = RandomValue(0.0f, pertubOrigin);
		pertub.y = RandomValue(0.0f, pertubOrigin);
		pertub.z = RandomValue(0.0f, pertubOrigin);
		const Vector3 newOrigin = mainRay.mOrigin + pertub;
		//const Vector3 newOrigin = mainRay.mOrigin;

		rayBundle.push_back(SimpleRay(newOrigin, newDir, 0));
	}

	return true;
}


void Preprocessor::SetupRay(Ray &ray,
							const Vector3 &point,
							const Vector3 &direction
							) const
{
	ray.Clear();
	// do not store anything else then intersections at the ray
	ray.Init(point, direction, Ray::LOCAL_RAY);
}


}