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source: trunk/VUT/GtpVisibilityPreprocessor/src/ViewCellBsp.cpp @ 424

Revision 424, 62.2 KB checked in by mattausch, 19 years ago (diff)

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1	#include "Plane3.h"
2	#include "ViewCellBsp.h"
3	#include "Mesh.h"
4	#include "common.h"
5	#include "ViewCell.h"
6	#include "Environment.h"
7	#include "Polygon3.h"
8	#include "Ray.h"
9	#include "AxisAlignedBox3.h"
10	#include <stack>
11	#include <time.h>
12	#include <iomanip>
13	#include "Exporter.h"
14	#include "Plane3.h"
15
16	//-- static members
17
18	int BspNode::sMailId = 1;
19
20	/** Evaluates split plane classification with respect to the plane's
21	contribution for a minimum number splits in the tree.
22	*/
23	const float BspTree::sLeastPolySplitsTable[] = {0, 0, 1, 0};
24	/** Evaluates split plane classification with respect to the plane's
25	contribution for a balanced tree.
26	*/
27	const float BspTree::sBalancedPolysTable[] = {1, -1, 0, 0};
28
29	/** Evaluates split plane classification with respect to the plane's
30	contribution for a minimum number of ray splits.
31	*/
32	const float BspTree::sLeastRaySplitsTable[] = {0, 0, 1, 1, 0};
33	/** Evaluates split plane classification with respect to the plane's
34	contribution for balanced rays.
35	*/
36	const float BspTree::sBalancedRaysTable[] = {1, -1, 0, 0, 0};
37
38	int BspTree::sConstructionMethod = FROM_INPUT_VIEW_CELLS;
39
40
41	/****************************************************************/
42	/* class BspNode implementation */
43	/****************************************************************/
44
45	BspNode::BspNode():
46	mParent(NULL)
47	{}
48
49	BspNode::BspNode(BspInterior *parent):
50	mParent(parent)
51	{}
52
53
54	bool BspNode::IsRoot() const
55	{
56	return mParent == NULL;
57	}
58
59	BspInterior *BspNode::GetParent()
60	{
61	return mParent;
62	}
63
64	void BspNode::SetParent(BspInterior *parent)
65	{
66	mParent = parent;
67	}
68
69	/****************************************************************/
70	/* class BspInterior implementation */
71	/****************************************************************/
72
73
74	BspInterior::BspInterior(const Plane3 &plane):
75	mPlane(plane), mFront(NULL), mBack(NULL)
76	{}
77
78	BspInterior::~BspInterior()
79	{
80	DEL_PTR(mFront);
81	DEL_PTR(mBack);
82	}
83
84	bool BspInterior::IsLeaf() const
85	{
86	return false;
87	}
88
89	BspNode *BspInterior::GetBack()
90	{
91	return mBack;
92	}
93
94	BspNode *BspInterior::GetFront()
95	{
96	return mFront;
97	}
98
99	Plane3 *BspInterior::GetPlane()
100	{
101	return &mPlane;
102	}
103
104	void BspInterior::ReplaceChildLink(BspNode oldChild, BspNode newChild)
105	{
106	if (mBack == oldChild)
107	mBack = newChild;
108	else
109	mFront = newChild;
110	}
111
112	void BspInterior::SetupChildLinks(BspNode b, BspNode f)
113	{
114	mBack = b;
115	mFront = f;
116	}
117
118	int BspInterior::SplitPolygons(PolygonContainer &polys,
119	PolygonContainer &frontPolys,
120	PolygonContainer &backPolys,
121	PolygonContainer &coincident)
122	{
123	Polygon3 *splitPoly = NULL;
124
125	int splits = 0;
126
127	#ifdef _Debug
128	Debug << "splitting polygons of node " << this << " with plane " << mPlane << endl;
129	#endif
130	while (!polys.empty())
131	{
132	Polygon3 *poly = polys.back();
133	polys.pop_back();
134
135	//Debug << "New polygon with plane: " << poly->GetSupportingPlane() << "\n";
136
137	// classify polygon
138	const int cf = poly->ClassifyPlane(mPlane);
139
140	Polygon3 *front_piece = NULL;
141	Polygon3 *back_piece = NULL;
142
143	VertexContainer splitVertices;
144
145	switch (cf)
146	{
147	case Polygon3::COINCIDENT:
148	coincident.push_back(poly);
149	break;
150	case Polygon3::FRONT_SIDE:
151	frontPolys.push_back(poly);
152	break;
153	case Polygon3::BACK_SIDE:
154	backPolys.push_back(poly);
155	break;
156	case Polygon3::SPLIT:
157	front_piece = new Polygon3(poly->mParent);
158	back_piece = new Polygon3(poly->mParent);
159
160	//-- split polygon into front and back part
161	poly->Split(mPlane,
162	*front_piece,
163	*back_piece,
164	splitVertices);
165
166	++ splits; // increase number of splits
167
168	//-- inherit rays from parent polygon for blocked ray criterium
169	poly->InheritRays(front_piece, back_piece);
170	//Debug << "p: " << poly->mPiercingRays.size() << " f: " << front_piece->mPiercingRays.size() << " b: " << back_piece->mPiercingRays.size() << endl;
171
172	// check if polygons still valid
173	if (front_piece->Valid())
174	frontPolys.push_back(front_piece);
175	else
176	DEL_PTR(front_piece);
177
178	if (back_piece->Valid())
179	backPolys.push_back(back_piece);
180	else
181	DEL_PTR(back_piece);
182
183	#ifdef _DEBUG
184	Debug << "split " << poly << endl << front_piece << endl << *back_piece << endl;
185	#endif
186	DEL_PTR(poly);
187	break;
188	default:
189	Debug << "SHOULD NEVER COME HERE\n";
190	break;
191	}
192	}
193
194	return splits;
195	}
196
197	/****************************************************************/
198	/* class BspLeaf implementation */
199	/****************************************************************/
200	BspLeaf::BspLeaf(): mViewCell(NULL)
201	{
202	}
203
204	BspLeaf::BspLeaf(BspViewCell *viewCell):
205	mViewCell(viewCell)
206	{
207	}
208
209	BspLeaf::BspLeaf(BspInterior *parent):
210	BspNode(parent), mViewCell(NULL)
211	{}
212
213	BspLeaf::BspLeaf(BspInterior parent, BspViewCell viewCell):
214	BspNode(parent), mViewCell(viewCell)
215	{
216	}
217
218	BspViewCell *BspLeaf::GetViewCell() const
219	{
220	return mViewCell;
221	}
222
223	void BspLeaf::SetViewCell(BspViewCell *viewCell)
224	{
225	mViewCell = viewCell;
226	}
227
228	bool BspLeaf::IsLeaf() const
229	{
230	return true;
231	}
232
233	void BspLeaf::AddToPvs(const BoundedRayContainer &rays,
234	int &sampleContributions,
235	int &contributingSamples,
236	bool storeLeavesWithRays)
237	{
238	sampleContributions = 0;
239	contributingSamples = 0;
240
241	BoundedRayContainer::const_iterator it, it_end = rays.end();
242
243	// add contributions from samples to the PVS
244	for (it = rays.begin(); it != it_end; ++ it)
245	{
246	int contribution = 0;
247	Ray ray = (it)->mRay;
248
249	if (!ray->intersections.empty())
250	contribution += mViewCell->GetPvs().AddSample(ray->intersections[0].mObject);
251
252	if (ray->sourceObject.mObject)
253	contribution += mViewCell->GetPvs().AddSample(ray->sourceObject.mObject);
254
255	if (contribution > 0)
256	{
257	sampleContributions += contribution;
258	++ contributingSamples;
259	}
260
261	if (storeLeavesWithRays)
262	// warning: intersections not ordered
263	ray->bspIntersections.push_back(Ray::BspIntersection((*it)->mMinT, this));
264	}
265	}
266
267
268	/****************************************************************/
269	/* class BspTree implementation */
270	/****************************************************************/
271
272	BspTree::BspTree(BspViewCell *viewCell):
273	mRootCell(viewCell),
274	mRoot(NULL),
275	mGenerateViewCells(false),
276	mStoreLeavesWithRays(false),
277	mPvsUseArea(true)
278	{
279	Randomize(); // initialise random generator for heuristics
280
281	//-- termination criteria for autopartition
282	environment->GetIntValue("BspTree.Termination.maxDepth", mTermMaxDepth);
283	environment->GetIntValue("BspTree.Termination.minPvs", mTermMinPvs);
284	environment->GetIntValue("BspTree.Termination.maxPolygons", mTermMaxPolygons);
285	environment->GetIntValue("BspTree.Termination.maxRays", mTermMaxRays);
286	environment->GetFloatValue("BspTree.Termination.minArea", mTermMinArea);
287	environment->GetFloatValue("BspTree.Termination.maxRayContribution", mTermMaxRayContribution);
288	environment->GetFloatValue("BspTree.Termination.maxAccRayLenght", mTermMaxAccRayLength);
289
290	//-- factors for bsp tree split plane heuristics
291	environment->GetFloatValue("BspTree.Factor.verticalSplits", mVerticalSplitsFactor);
292	environment->GetFloatValue("BspTree.Factor.largestPolyArea", mLargestPolyAreaFactor);
293	environment->GetFloatValue("BspTree.Factor.blockedRays", mBlockedRaysFactor);
294	environment->GetFloatValue("BspTree.Factor.leastRaySplits", mLeastRaySplitsFactor);
295	environment->GetFloatValue("BspTree.Factor.balancedRays", mBalancedRaysFactor);
296	environment->GetFloatValue("BspTree.Factor.pvsFactor", mPvsFactor);
297	environment->GetFloatValue("BspTree.Factor.leastSplits" , mLeastSplitsFactor);
298	environment->GetFloatValue("BspTree.Factor.balancedPolys", mBalancedPolysFactor);
299	environment->GetFloatValue("BspTree.Factor.balancedViewCells", mBalancedViewCellsFactor);
300	environment->GetFloatValue("BspTree.Termination.ct_div_ci", mCtDivCi);
301
302	//-- termination criteria for axis aligned split
303	environment->GetFloatValue("BspTree.Termination.AxisAligned.ct_div_ci", mAaCtDivCi);
304	environment->GetFloatValue("BspTree.Termination.AxisAligned.maxCostRatio", mMaxCostRatio);
305	environment->GetIntValue("BspTree.Termination.AxisAligned.maxPolys",
306	mTermMaxPolysForAxisAligned);
307	environment->GetIntValue("BspTree.Termination.AxisAligned.maxRays",
308	mTermMaxRaysForAxisAligned);
309	environment->GetIntValue("BspTree.Termination.AxisAligned.maxObjects",
310	mTermMaxObjectsForAxisAligned);
311	//-- partition criteria
312	environment->GetIntValue("BspTree.maxPolyCandidates", mMaxPolyCandidates);
313	environment->GetIntValue("BspTree.maxRayCandidates", mMaxRayCandidates);
314	environment->GetIntValue("BspTree.splitPlaneStrategy", mSplitPlaneStrategy);
315	environment->GetFloatValue("BspTree.AxisAligned.splitBorder", mSplitBorder);
316
317	environment->GetFloatValue("BspTree.Construction.sideTolerance", Vector3::sDistTolerance);
318	Vector3::sDistToleranceSqrt = Vector3::sDistTolerance * Vector3::sDistTolerance;
319
320	// post processing stuff
321	environment->GetIntValue("ViewCells.PostProcessing.minPvsDif", mMinPvsDif);
322	environment->GetIntValue("ViewCells.PostProcessing.minPvs", mMinPvs);
323	environment->GetIntValue("ViewCells.PostProcessing.maxPvs", mMaxPvs);
324
325	Debug << "BSP max depth: " << mTermMaxDepth << endl;
326	Debug << "BSP min PVS: " << mTermMinPvs << endl;
327	Debug << "BSP min area: " << mTermMinArea << endl;
328	Debug << "BSP max polys: " << mTermMaxPolygons << endl;
329	Debug << "BSP max rays: " << mTermMaxRays << endl;
330	Debug << "BSP max polygon candidates: " << mMaxPolyCandidates << endl;
331	Debug << "BSP max plane candidates: " << mMaxRayCandidates << endl;
332
333	Debug << "Split plane strategy: ";
334	if (mSplitPlaneStrategy & RANDOM_POLYGON)
335	Debug << "random polygon ";
336	if (mSplitPlaneStrategy & AXIS_ALIGNED)
337	Debug << "axis aligned ";
338	if (mSplitPlaneStrategy & LEAST_SPLITS)
339	Debug << "least splits ";
340	if (mSplitPlaneStrategy & BALANCED_POLYS)
341	Debug << "balanced polygons ";
342	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
343	Debug << "balanced view cells ";
344	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
345	Debug << "largest polygon area ";
346	if (mSplitPlaneStrategy & VERTICAL_AXIS)
347	Debug << "vertical axis ";
348	if (mSplitPlaneStrategy & BLOCKED_RAYS)
349	Debug << "blocked rays ";
350	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
351	Debug << "least ray splits ";
352	if (mSplitPlaneStrategy & BALANCED_RAYS)
353	Debug << "balanced rays ";
354	if (mSplitPlaneStrategy & PVS)
355	Debug << "pvs";
356
357	Debug << endl;
358	}
359
360	void BspTree::ParseEnvironment()
361	{
362	//-- parse bsp cell tree construction method
363	char constructionMethodStr[60];
364
365	environment->GetStringValue("BspTree.Construction.input", constructionMethodStr);
366
367	sConstructionMethod = FROM_INPUT_VIEW_CELLS;
368
369	if (strcmp(constructionMethodStr, "fromViewCells") == 0)
370	sConstructionMethod = FROM_INPUT_VIEW_CELLS;
371	else if (strcmp(constructionMethodStr, "fromSceneGeometry") == 0)
372	sConstructionMethod = FROM_SCENE_GEOMETRY;
373	else if (strcmp(constructionMethodStr, "fromSamples") == 0)
374	sConstructionMethod = FROM_SAMPLES;
375	else
376	{
377	cerr << "Wrong construction method " << constructionMethodStr << endl;
378	exit(1);
379	}
380
381	Debug << "Construction method: " << constructionMethodStr << endl;
382	}
383
384	const BspTreeStatistics &BspTree::GetStatistics() const
385	{
386	return mStat;
387	}
388
389	void BspTreeStatistics::Print(ostream &app) const
390	{
391	app << "===== BspTree statistics ===============\n";
392
393	app << setprecision(4);
394
395	app << "#N_CTIME ( Construction time [s] )\n" << Time() << " \n";
396
397	app << "#N_NODES ( Number of nodes )\n" << nodes << "\n";
398
399	app << "#N_INTERIORS ( Number of interior nodes )\n" << Interior() << "\n";
400
401	app << "#N_LEAVES ( Number of leaves )\n" << Leaves() << "\n";
402
403	app << "#N_SPLITS ( Number of splits )\n" << splits << "\n";
404
405	app << "#N_PMAXDEPTHLEAVES ( Percentage of leaves at maxdepth )\n"<<
406	maxDepthNodes * 100 / (double)Leaves() << endl;
407
408	app << "#N_PMAXDEPTH ( Maximal reached depth )\n" << maxDepth << endl;
409
410	app << "#N_PMINDEPTH ( Minimal reached depth )\n" << minDepth << endl;
411
412	app << "#AVGDEPTH ( average depth )\n" << AvgDepth() << endl;
413
414	app << "#N_INPUT_POLYGONS (number of input polygons )\n" << polys << endl;
415
416	//app << "#N_PVS: " << pvs << endl;
417
418	app << "#N_ROUTPUT_INPUT_POLYGONS ( ratio polygons after subdivision / input polygons )\n" <<
419	(polys + splits) / (double)polys << endl;
420
421	app << "===== END OF BspTree statistics ==========\n";
422	}
423
424
425	BspTree::~BspTree()
426	{
427	DEL_PTR(mRoot);
428	}
429
430	void BspTree::InsertViewCell(ViewCell *viewCell)
431	{
432	PolygonContainer *polys = new PolygonContainer();
433
434	// extract polygons that guide the split process
435	mStat.polys += AddMeshToPolygons(viewCell->GetMesh(), *polys, viewCell);
436	mBox.Include(viewCell->GetBox()); // add to BSP aabb
437
438	InsertPolygons(polys);
439	}
440
441	void BspTree::InsertPolygons(PolygonContainer *polys)
442	{
443	std::stack<BspTraversalData> tStack;
444
445	// traverse existing tree or create new tree
446	if (!mRoot)
447	mRoot = new BspLeaf();
448
449	tStack.push(BspTraversalData(mRoot, polys, 0, mRootCell, new BoundedRayContainer(), 0,
450	mBox.SurfaceArea(), new BspNodeGeometry()));
451
452	while (!tStack.empty())
453	{
454	// filter polygons donw the tree
455	BspTraversalData tData = tStack.top();
456	tStack.pop();
457
458	if (!tData.mNode->IsLeaf())
459	{
460	BspInterior interior = dynamic_cast<BspInterior >(tData.mNode);
461
462	//-- filter view cell polygons down the tree until a leaf is reached
463	if (!tData.mPolygons->empty())
464	{
465	PolygonContainer *frontPolys = new PolygonContainer();
466	PolygonContainer *backPolys = new PolygonContainer();
467	PolygonContainer coincident;
468
469	int splits = 0;
470
471	// split viewcell polygons with respect to split plane
472	splits += interior->SplitPolygons(*tData.mPolygons,
473	*frontPolys,
474	*backPolys,
475	coincident);
476
477	// extract view cells associated with the split polygons
478	ViewCell *frontViewCell = mRootCell;
479	ViewCell *backViewCell = mRootCell;
480
481	BspTraversalData frontData(interior->GetFront(),
482	frontPolys,
483	tData.mDepth + 1,
484	mRootCell,
485	tData.mRays,
486	tData.mPvs,
487	mBox.SurfaceArea(),
488	new BspNodeGeometry());
489
490	BspTraversalData backData(interior->GetBack(),
491	backPolys,
492	tData.mDepth + 1,
493	mRootCell,
494	tData.mRays,
495	tData.mPvs,
496	mBox.SurfaceArea(),
497	new BspNodeGeometry());
498
499	if (!mGenerateViewCells)
500	{
501	ExtractViewCells(frontData,
502	backData,
503	coincident,
504	interior->mPlane);
505	}
506
507	// don't need coincident polygons anymore
508	CLEAR_CONTAINER(coincident);
509
510	mStat.splits += splits;
511
512	// push the children on the stack
513	tStack.push(frontData);
514	tStack.push(backData);
515	}
516
517	// cleanup
518	DEL_PTR(tData.mPolygons);
519	}
520	else
521	{
522	// reached leaf => subdivide current viewcell
523	BspNode *subRoot = Subdivide(tStack, tData);
524	}
525	}
526	}
527
528	int BspTree::AddMeshToPolygons(Mesh mesh, PolygonContainer &polys, MeshInstance parent)
529	{
530	FaceContainer::const_iterator fi;
531
532	// copy the face data to polygons
533	for (fi = mesh->mFaces.begin(); fi != mesh->mFaces.end(); ++ fi)
534	{
535	Polygon3 poly = new Polygon3((fi), mesh);
536
537	if (poly->Valid())
538	{
539	poly->mParent = parent; // set parent intersectable
540	polys.push_back(poly);
541	}
542	else
543	DEL_PTR(poly);
544	}
545	return (int)mesh->mFaces.size();
546	}
547
548	int BspTree::AddToPolygonSoup(const ViewCellContainer &viewCells,
549	PolygonContainer &polys,
550	int maxObjects)
551	{
552	int limit = (maxObjects > 0) ?
553	Min((int)viewCells.size(), maxObjects) : (int)viewCells.size();
554
555	int polysSize = 0;
556
557	for (int i = 0; i < limit; ++ i)
558	{
559	if (viewCells[i]->GetMesh()) // copy the mesh data to polygons
560	{
561	mBox.Include(viewCells[i]->GetBox()); // add to BSP tree aabb
562	polysSize += AddMeshToPolygons(viewCells[i]->GetMesh(), polys, viewCells[i]);
563	}
564	}
565
566	return polysSize;
567	}
568
569	int BspTree::AddToPolygonSoup(const ObjectContainer &objects, PolygonContainer &polys, int maxObjects)
570	{
571	int limit = (maxObjects > 0) ? Min((int)objects.size(), maxObjects) : (int)objects.size();
572
573	for (int i = 0; i < limit; ++i)
574	{
575	Intersectable object = objects[i];//it;
576	Mesh *mesh = NULL;
577
578	switch (object->Type()) // extract the meshes
579	{
580	case Intersectable::MESH_INSTANCE:
581	mesh = dynamic_cast<MeshInstance *>(object)->GetMesh();
582	break;
583	case Intersectable::VIEW_CELL:
584	mesh = dynamic_cast<ViewCell *>(object)->GetMesh();
585	break;
586	// TODO: handle transformed mesh instances
587	default:
588	Debug << "intersectable type not supported" << endl;
589	break;
590	}
591
592	if (mesh) // copy the mesh data to polygons
593	{
594	mBox.Include(object->GetBox()); // add to BSP tree aabb
595	AddMeshToPolygons(mesh, polys, mRootCell);
596	}
597	}
598
599	return (int)polys.size();
600	}
601
602	void BspTree::Construct(const ViewCellContainer &viewCells)
603	{
604	mStat.nodes = 1;
605	mBox.Initialize(); // initialise bsp tree bounding box
606
607	// copy view cell meshes into one big polygon soup
608	PolygonContainer *polys = new PolygonContainer();
609	mStat.polys = AddToPolygonSoup(viewCells, *polys);
610
611	// construct tree from the view cell polygons
612	Construct(polys, new BoundedRayContainer());
613	}
614
615
616	void BspTree::Construct(const ObjectContainer &objects)
617	{
618	mStat.nodes = 1;
619	mBox.Initialize(); // initialise bsp tree bounding box
620
621	PolygonContainer *polys = new PolygonContainer();
622
623	// copy mesh instance polygons into one big polygon soup
624	mStat.polys = AddToPolygonSoup(objects, *polys);
625
626	// construct tree from polygon soup
627	Construct(polys, new BoundedRayContainer());
628	}
629
630	void BspTree::Construct(const RayContainer &sampleRays)
631	{
632	mStat.nodes = 1;
633	mBox.Initialize(); // initialise BSP tree bounding box
634
635	PolygonContainer *polys = new PolygonContainer();
636	BoundedRayContainer *rays = new BoundedRayContainer();
637
638	RayContainer::const_iterator rit, rit_end = sampleRays.end();
639
640	long startTime = GetTime();
641
642	Debug << "** Extracting polygons from rays **\n";
643
644	std::map<Face , Polygon3 > facePolyMap;
645
646	//-- extract polygons intersected by the rays
647	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
648	{
649	Ray ray = rit;
650
651	// get ray-face intersection. Store polygon representing the rays together
652	// with rays intersecting the face.
653	if (!ray->intersections.empty())
654	{
655	MeshInstance obj = dynamic_cast<MeshInstance >(ray->intersections[0].mObject);
656	Face *face = obj->GetMesh()->mFaces[ray->intersections[0].mFace];
657
658	std::map<Face , Polygon3 >::iterator it = facePolyMap.find(face);
659
660	if (it != facePolyMap.end())
661	{
662	//store rays if needed for heuristics
663	if (mSplitPlaneStrategy & BLOCKED_RAYS)
664	(*it).second->mPiercingRays.push_back(ray);
665	}
666	else
667	{ //store rays if needed for heuristics
668	Polygon3 *poly = new Polygon3(face, obj->GetMesh());
669	poly->mParent = obj;
670	polys->push_back(poly);
671
672	if (mSplitPlaneStrategy & BLOCKED_RAYS)
673	poly->mPiercingRays.push_back(ray);
674
675	facePolyMap[face] = poly;
676	}
677	}
678	}
679
680	facePolyMap.clear();
681
682	// compue bounding box
683	Polygon3::IncludeInBox(*polys, mBox);
684
685	//-- store rays
686	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
687	{
688	Ray ray = rit;
689	ray->SetId(-1); // reset id
690
691	float minT, maxT;
692	if (BoundRay(*ray, minT, maxT))
693	rays->push_back(new BoundedRay(ray, minT, maxT));
694	}
695
696	mStat.polys = (int)polys->size();
697
698	Debug << "** Finished polygon extraction **" << endl;
699	Debug << (int)polys->size() << " polys extracted from " << (int)sampleRays.size() << " rays" << endl;
700	Debug << "extraction time: " << TimeDiff(startTime, GetTime())*1e-3 << "s" << endl;
701
702	Construct(polys, rays);
703	}
704
705	void BspTree::Construct(PolygonContainer polys, BoundedRayContainer rays)
706	{
707	std::stack<BspTraversalData> tStack;
708
709	mRoot = new BspLeaf();
710
711	BspNodeGeometry *cell = new BspNodeGeometry();
712	ConstructGeometry(mRoot, *cell);
713
714	BspTraversalData tData(mRoot, polys, 0, mRootCell, rays,
715	ComputePvsSize(*rays), cell->GetArea(), cell);
716
717	tStack.push(tData);
718
719	mStat.Start();
720	cout << "** Contructing bsp tree **\n";
721
722	while (!tStack.empty())
723	{
724	tData = tStack.top();
725	tStack.pop();
726
727	// subdivide leaf node
728	BspNode *subRoot = Subdivide(tStack, tData);
729	}
730
731	mStat.Stop();
732	}
733
734	bool BspTree::TerminationCriteriaMet(const BspTraversalData &data) const
735	{
736	return
737	(((int)data.mPolygons->size() <= mTermMaxPolygons) \|\|
738	((int)data.mRays->size() <= mTermMaxRays) \|\|
739	(data.mPvs <= mTermMinPvs) \|\|
740	(data.mArea <= mTermMinArea) \|\|
741	(data.mDepth >= mTermMaxDepth) \|\|
742	(data.GetAvgRayContribution() < mTermMaxRayContribution));
743	}
744
745	BspNode *BspTree::Subdivide(BspTraversalStack &tStack, BspTraversalData &tData)
746	{
747	//-- terminate traversal
748	if (TerminationCriteriaMet(tData))
749	{
750	BspLeaf leaf = dynamic_cast<BspLeaf >(tData.mNode);
751
752	BspViewCell *viewCell;
753
754	// generate new view cell for each leaf
755	if (mGenerateViewCells)
756	{
757	viewCell = dynamic_cast<BspViewCell *>(ViewCell::Generate());
758	}
759	else
760	{
761	// add view cell to leaf
762	viewCell = dynamic_cast<BspViewCell *>(tData.mViewCell);
763	}
764
765	leaf->SetViewCell(viewCell);
766	viewCell->mBspLeaves.push_back(leaf);
767
768	//-- add pvs
769	if (viewCell != mRootCell)
770	{
771	int conSamp = 0, sampCon = 0;
772	leaf->AddToPvs(*tData.mRays, conSamp, sampCon);
773
774	mStat.contributingSamples += conSamp;
775	mStat.sampleContributions += sampCon;
776	}
777
778	EvaluateLeafStats(tData);
779
780	//-- clean up
781
782	// discard polygons
783	CLEAR_CONTAINER(*tData.mPolygons);
784	// discard rays
785	CLEAR_CONTAINER(*tData.mRays);
786
787	DEL_PTR(tData.mPolygons);
788	DEL_PTR(tData.mRays);
789	DEL_PTR(tData.mGeometry);
790
791	return leaf;
792	}
793
794	//-- continue subdivision
795	PolygonContainer coincident;
796
797	PolygonContainer *frontPolys = new PolygonContainer();
798	PolygonContainer *backPolys = new PolygonContainer();
799
800	BoundedRayContainer *frontRays = new BoundedRayContainer();
801	BoundedRayContainer *backRays = new BoundedRayContainer();
802
803	BspTraversalData tFrontData(NULL, new PolygonContainer(), tData.mDepth + 1, mRootCell,
804	new BoundedRayContainer(), 0, 0, new BspNodeGeometry());
805	BspTraversalData tBackData(NULL, new PolygonContainer(), tData.mDepth + 1, mRootCell,
806	new BoundedRayContainer(), 0, 0, new BspNodeGeometry());
807
808	// create new interior node and two leaf nodes
809	BspInterior *interior = SubdivideNode(tData,
810	tFrontData,
811	tBackData,
812	coincident);
813
814	#ifdef _DEBUG
815	if (frontPolys->empty() && backPolys->empty() && (coincident.size() > 2))
816	{ for (PolygonContainer::iterator it = coincident.begin(); it != coincident.end(); ++it)
817	Debug << (it) << " " << (it)->GetArea() << " " << (*it)->mParent << endl ;
818	Debug << endl;}
819	#endif
820
821	// extract view cells from coincident polygons according to plane normal
822	// only if front or back polygons are empty
823	if (!mGenerateViewCells)
824	{
825	ExtractViewCells(tFrontData,
826	tBackData,
827	coincident,
828	interior->mPlane);
829	}
830
831	// don't need coincident polygons anymory
832	CLEAR_CONTAINER(coincident);
833
834	// push the children on the stack
835	tStack.push(tFrontData);
836	tStack.push(tBackData);
837
838	// cleanup
839	DEL_PTR(tData.mNode);
840	DEL_PTR(tData.mPolygons);
841	DEL_PTR(tData.mRays);
842	DEL_PTR(tData.mGeometry);
843
844	return interior;
845	}
846
847	void BspTree::ExtractViewCells(BspTraversalData &frontData,
848	BspTraversalData &backData,
849	const PolygonContainer &coincident,
850	const Plane3 splitPlane) const
851	{
852	// if not empty, tree is further subdivided => don't have to find view cell
853	bool foundFront = !frontData.mPolygons->empty();
854	bool foundBack = !frontData.mPolygons->empty();
855
856	PolygonContainer::const_iterator it =
857	coincident.begin(), it_end = coincident.end();
858
859	//-- find first view cells in front and back leafs
860	for (; !(foundFront && foundBack) && (it != it_end); ++ it)
861	{
862	if (DotProd((*it)->GetNormal(), splitPlane.mNormal) > 0)
863	{
864	backData.mViewCell = dynamic_cast<ViewCell >((it)->mParent);
865	foundBack = true;
866	}
867	else
868	{
869	frontData.mViewCell = dynamic_cast<ViewCell >((it)->mParent);
870	foundFront = true;
871	}
872	}
873	}
874
875	BspInterior *BspTree::SubdivideNode(BspTraversalData &tData,
876	BspTraversalData &frontData,
877	BspTraversalData &backData,
878	PolygonContainer &coincident)
879	{
880	mStat.nodes += 2;
881
882	BspLeaf leaf = dynamic_cast<BspLeaf >(tData.mNode);
883	// select subdivision plane
884	BspInterior *interior =
885	new BspInterior(SelectPlane(leaf, tData));
886
887	#ifdef _DEBUG
888	Debug << interior << endl;
889	#endif
890
891	// subdivide rays into front and back rays
892	SplitRays(interior->mPlane, tData.mRays, frontData.mRays, *backData.mRays);
893
894	// subdivide polygons with plane
895	mStat.splits += interior->SplitPolygons(*tData.mPolygons,
896	*frontData.mPolygons,
897	*backData.mPolygons,
898	coincident);
899
900	// compute pvs
901	frontData.mPvs = ComputePvsSize(*frontData.mRays);
902	backData.mPvs = ComputePvsSize(*backData.mRays);
903
904	// split geometry and compute area
905	if (1)
906	{
907	tData.mGeometry->SplitGeometry(*frontData.mGeometry,
908	*backData.mGeometry,
909	*this,
910	interior->mPlane);
911
912
913	frontData.mArea = frontData.mGeometry->GetArea();
914	backData.mArea = backData.mGeometry->GetArea();
915	}
916
917	// compute accumulated ray length
918	//frontData.mAccRayLength = AccumulatedRayLength(*frontData.mRays);
919	//backData.mAccRayLength = AccumulatedRayLength(*backData.mRays);
920
921	//-- create front and back leaf
922
923	BspInterior *parent = leaf->GetParent();
924
925	// replace a link from node's parent
926	if (!leaf->IsRoot())
927	{
928	parent->ReplaceChildLink(leaf, interior);
929	interior->SetParent(parent);
930	}
931	else // new root
932	{
933	mRoot = interior;
934	}
935
936	// and setup child links
937	interior->SetupChildLinks(new BspLeaf(interior), new BspLeaf(interior));
938
939	frontData.mNode = interior->mFront;
940	backData.mNode = interior->mBack;
941
942	//DEL_PTR(leaf);
943	return interior;
944	}
945
946	void BspTree::SortSplitCandidates(const PolygonContainer &polys,
947	const int axis,
948	vector<SortableEntry> &splitCandidates) const
949	{
950	splitCandidates.clear();
951
952	int requestedSize = 2 * (int)polys.size();
953	// creates a sorted split candidates array
954	splitCandidates.reserve(requestedSize);
955
956	PolygonContainer::const_iterator it, it_end = polys.end();
957
958	AxisAlignedBox3 box;
959
960	// insert all queries
961	for(it = polys.begin(); it != it_end; ++ it)
962	{
963	box.Initialize();
964	box.Include((it));
965
966	splitCandidates.push_back(SortableEntry(SortableEntry::POLY_MIN, box.Min(axis), *it));
967	splitCandidates.push_back(SortableEntry(SortableEntry::POLY_MAX, box.Max(axis), *it));
968	}
969
970	stable_sort(splitCandidates.begin(), splitCandidates.end());
971	}
972
973
974	float BspTree::BestCostRatio(const PolygonContainer &polys,
975	const AxisAlignedBox3 &box,
976	const int axis,
977	float &position,
978	int &objectsBack,
979	int &objectsFront) const
980	{
981	vector<SortableEntry> splitCandidates;
982
983	SortSplitCandidates(polys, axis, splitCandidates);
984
985	// go through the lists, count the number of objects left and right
986	// and evaluate the following cost funcion:
987	// C = ct_div_ci + (ol + or)/queries
988
989	int objectsLeft = 0, objectsRight = (int)polys.size();
990
991	float minBox = box.Min(axis);
992	float maxBox = box.Max(axis);
993	float boxArea = box.SurfaceArea();
994
995	float minBand = minBox + mSplitBorder * (maxBox - minBox);
996	float maxBand = minBox + (1.0f - mSplitBorder) * (maxBox - minBox);
997
998	float minSum = 1e20f;
999	vector<SortableEntry>::const_iterator ci, ci_end = splitCandidates.end();
1000
1001	for(ci = splitCandidates.begin(); ci != ci_end; ++ ci)
1002	{
1003	switch ((*ci).type)
1004	{
1005	case SortableEntry::POLY_MIN:
1006	++ objectsLeft;
1007	break;
1008	case SortableEntry::POLY_MAX:
1009	-- objectsRight;
1010	break;
1011	default:
1012	break;
1013	}
1014
1015	if ((ci).value > minBand && (ci).value < maxBand)
1016	{
1017	AxisAlignedBox3 lbox = box;
1018	AxisAlignedBox3 rbox = box;
1019	lbox.SetMax(axis, (*ci).value);
1020	rbox.SetMin(axis, (*ci).value);
1021
1022	float sum = objectsLeft * lbox.SurfaceArea() +
1023	objectsRight * rbox.SurfaceArea();
1024
1025	if (sum < minSum)
1026	{
1027	minSum = sum;
1028	position = (*ci).value;
1029
1030	objectsBack = objectsLeft;
1031	objectsFront = objectsRight;
1032	}
1033	}
1034	}
1035
1036	float oldCost = (float)polys.size();
1037	float newCost = mAaCtDivCi + minSum / boxArea;
1038	float ratio = newCost / oldCost;
1039
1040
1041	#if 0
1042	Debug << "====================" << endl;
1043	Debug << "costRatio=" << ratio << " pos=" << position<<" t=" << (position - minBox)/(maxBox - minBox)
1044	<< "\t o=(" << objectsBack << "," << objectsFront << ")" << endl;
1045	#endif
1046	return ratio;
1047	}
1048
1049	bool BspTree::SelectAxisAlignedPlane(Plane3 &plane,
1050	const PolygonContainer &polys) const
1051	{
1052	AxisAlignedBox3 box;
1053	box.Initialize();
1054
1055	// create bounding box of region
1056	Polygon3::IncludeInBox(polys, box);
1057
1058	int objectsBack = 0, objectsFront = 0;
1059	int axis = 0;
1060	float costRatio = MAX_FLOAT;
1061	Vector3 position;
1062
1063	//-- area subdivision
1064	for (int i = 0; i < 3; ++ i)
1065	{
1066	float p = 0;
1067	float r = BestCostRatio(polys, box, i, p, objectsBack, objectsFront);
1068
1069	if (r < costRatio)
1070	{
1071	costRatio = r;
1072	axis = i;
1073	position = p;
1074	}
1075	}
1076
1077	if (costRatio >= mMaxCostRatio)
1078	return false;
1079
1080	Vector3 norm(0,0,0); norm[axis] = 1.0f;
1081	plane = Plane3(norm, position);
1082
1083	return true;
1084	}
1085
1086	Plane3 BspTree::SelectPlane(BspLeaf *leaf, BspTraversalData &data)
1087	{
1088	if (data.mPolygons->empty() && data.mRays->empty())
1089	{
1090	Debug << "Warning: No autopartition polygon candidate available\n";
1091
1092	// return axis aligned split
1093	AxisAlignedBox3 box;
1094	box.Initialize();
1095
1096	// create bounding box of region
1097	Polygon3::IncludeInBox(*data.mPolygons, box);
1098
1099	const int axis = box.Size().DrivingAxis();
1100	const Vector3 position = (box.Min()[axis] + box.Max()[axis])*0.5f;
1101
1102	Vector3 norm(0,0,0); norm[axis] = 1.0f;
1103	return Plane3(norm, position);
1104	}
1105
1106	if ((mSplitPlaneStrategy & AXIS_ALIGNED) &&
1107	((int)data.mPolygons->size() > mTermMaxPolysForAxisAligned) &&
1108	((int)data.mRays->size() > mTermMaxRaysForAxisAligned) &&
1109	((mTermMaxObjectsForAxisAligned < 0) \|\|
1110	(Polygon3::ParentObjectsSize(*data.mPolygons) > mTermMaxObjectsForAxisAligned)))
1111	{
1112	Plane3 plane;
1113	if (SelectAxisAlignedPlane(plane, *data.mPolygons))
1114	return plane;
1115	}
1116
1117	// simplest strategy: just take next polygon
1118	if (mSplitPlaneStrategy & RANDOM_POLYGON)
1119	{
1120	if (!data.mPolygons->empty())
1121	{
1122	Polygon3 nextPoly = (data.mPolygons)[Random((int)data.mPolygons->size())];
1123	return nextPoly->GetSupportingPlane();
1124	}
1125	else
1126	{
1127	const int candidateIdx = Random((int)data.mRays->size());
1128	BoundedRay bRay = (data.mRays)[candidateIdx];
1129
1130	Ray *ray = bRay->mRay;
1131
1132	const Vector3 minPt = ray->Extrap(bRay->mMinT);
1133	const Vector3 maxPt = ray->Extrap(bRay->mMaxT);
1134
1135	const Vector3 pt = (maxPt + minPt) * 0.5;
1136
1137	const Vector3 normal = ray->GetDir();
1138
1139	return Plane3(normal, pt);
1140	}
1141
1142	return Plane3();
1143	}
1144
1145	// use heuristics to find appropriate plane
1146	return SelectPlaneHeuristics(leaf, data);
1147	}
1148
1149	Plane3 BspTree::SelectPlaneHeuristics(BspLeaf *leaf, BspTraversalData &data)
1150	{
1151	float lowestCost = MAX_FLOAT;
1152	Plane3 bestPlane;
1153	Plane3 plane;
1154
1155	int limit = Min((int)data.mPolygons->size(), mMaxPolyCandidates);
1156
1157	int candidateIdx = limit;
1158
1159	for (int i = 0; i < limit; ++ i)
1160	{
1161	candidateIdx = GetNextCandidateIdx(candidateIdx, *data.mPolygons);
1162
1163	Polygon3 poly = (data.mPolygons)[candidateIdx];
1164	// evaluate current candidate
1165	const float candidateCost =
1166	SplitPlaneCost(poly->GetSupportingPlane(), data);
1167
1168	if (candidateCost < lowestCost)
1169	{
1170	bestPlane = poly->GetSupportingPlane();
1171	lowestCost = candidateCost;
1172	}
1173	}
1174
1175	//Debug << "lowest: " << lowestCost << endl;
1176
1177	//-- choose candidate planes extracted from rays
1178	// we currently use two methods
1179	// 1) take 3 ray endpoints, where two are minimum and one a maximum
1180	// point or the other way round
1181	// 2) take plane normal as plane normal and the midpoint of the ray.
1182	// PROBLEM: does not resemble any point where visibility is likely to change
1183	const BoundedRayContainer *rays = data.mRays;
1184
1185	for (int i = 0; i < mMaxRayCandidates / 2; ++ i)
1186	{
1187	candidateIdx = Random((int)rays->size());
1188	BoundedRay bRay = (rays)[candidateIdx];
1189
1190	Ray *ray = bRay->mRay;
1191
1192	const Vector3 minPt = ray->Extrap(bRay->mMinT);
1193	const Vector3 maxPt = ray->Extrap(bRay->mMaxT);
1194
1195	const Vector3 pt = (maxPt + minPt) * 0.5;
1196
1197	const Vector3 normal = ray->GetDir();
1198
1199	plane = Plane3(normal, pt);
1200
1201	const float candidateCost = SplitPlaneCost(plane, data);
1202
1203	if (candidateCost < lowestCost)
1204	{
1205	bestPlane = plane;
1206
1207	lowestCost = candidateCost;
1208	}
1209	}
1210
1211	//Debug << "lowest: " << lowestCost << endl;
1212	for (int i = 0; i < mMaxRayCandidates / 2; ++ i)
1213	{
1214	Vector3 pt[3];
1215	int idx[3];
1216	int cmaxT = 0;
1217	int cminT = 0;
1218	bool chooseMin = false;
1219
1220	for (int j = 0; j < 3; j ++)
1221	{
1222	idx[j] = Random((int)rays->size() * 2);
1223
1224	if (idx[j] >= (int)rays->size())
1225	{
1226	idx[j] -= (int)rays->size();
1227
1228	chooseMin = (cminT < 2);
1229	}
1230	else
1231	chooseMin = (cmaxT < 2);
1232
1233	BoundedRay bRay = (rays)[idx[j]];
1234	pt[j] = chooseMin ? bRay->mRay->Extrap(bRay->mMinT) : bRay->mRay->Extrap(bRay->mMaxT);
1235	}
1236
1237	plane = Plane3(pt[0], pt[1], pt[2]);
1238
1239	const float candidateCost = SplitPlaneCost(plane, data);
1240
1241	if (candidateCost < lowestCost)
1242	{
1243	//Debug << "choose ray plane 2: " << candidateCost << endl;
1244	bestPlane = plane;
1245
1246	lowestCost = candidateCost;
1247	}
1248	}
1249
1250	#ifdef _DEBUG
1251	Debug << "plane lowest cost: " << lowestCost << endl;
1252	#endif
1253	return bestPlane;
1254	}
1255
1256	int BspTree::GetNextCandidateIdx(int currentIdx, PolygonContainer &polys)
1257	{
1258	const int candidateIdx = Random(currentIdx --);
1259
1260	// swap candidates to avoid testing same plane 2 times
1261	std::swap(polys[currentIdx], polys[candidateIdx]);
1262
1263	return currentIdx;
1264	//return Random((int)polys.size());
1265	}
1266
1267	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1268	const PolygonContainer &polys) const
1269	{
1270	float val = 0;
1271
1272	float sumBalancedPolys = 0;
1273	float sumSplits = 0;
1274	float sumPolyArea = 0;
1275	float sumBalancedViewCells = 0;
1276	float sumBlockedRays = 0;
1277	float totalBlockedRays = 0;
1278	//float totalArea = 0;
1279	int totalViewCells = 0;
1280
1281	// need three unique ids for each type of view cell
1282	// for balanced view cells criterium
1283	ViewCell::NewMail();
1284	const int backId = ViewCell::sMailId;
1285	ViewCell::NewMail();
1286	const int frontId = ViewCell::sMailId;
1287	ViewCell::NewMail();
1288	const int frontAndBackId = ViewCell::sMailId;
1289
1290	PolygonContainer::const_iterator it, it_end = polys.end();
1291
1292	for (it = polys.begin(); it != it_end; ++ it)
1293	{
1294	const int classification = (*it)->ClassifyPlane(candidatePlane);
1295
1296	if (mSplitPlaneStrategy & BALANCED_POLYS)
1297	sumBalancedPolys += sBalancedPolysTable[classification];
1298
1299	if (mSplitPlaneStrategy & LEAST_SPLITS)
1300	sumSplits += sLeastPolySplitsTable[classification];
1301
1302	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
1303	{
1304	if (classification == Polygon3::COINCIDENT)
1305	sumPolyArea += (*it)->GetArea();
1306	//totalArea += area;
1307	}
1308
1309	if (mSplitPlaneStrategy & BLOCKED_RAYS)
1310	{
1311	const float blockedRays = (float)(*it)->mPiercingRays.size();
1312
1313	if (classification == Polygon3::COINCIDENT)
1314	sumBlockedRays += blockedRays;
1315
1316	totalBlockedRays += blockedRays;
1317	}
1318
1319	// assign view cells to back or front according to classificaion
1320	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
1321	{
1322	MeshInstance viewCell = (it)->mParent;
1323
1324	// assure that we only count a view cell
1325	// once for the front and once for the back side of the plane
1326	if (classification == Polygon3::FRONT_SIDE)
1327	{
1328	if ((viewCell->mMailbox != frontId) &&
1329	(viewCell->mMailbox != frontAndBackId))
1330	{
1331	sumBalancedViewCells += 1.0;
1332
1333	if (viewCell->mMailbox != backId)
1334	viewCell->mMailbox = frontId;
1335	else
1336	viewCell->mMailbox = frontAndBackId;
1337
1338	++ totalViewCells;
1339	}
1340	}
1341	else if (classification == Polygon3::BACK_SIDE)
1342	{
1343	if ((viewCell->mMailbox != backId) &&
1344	(viewCell->mMailbox != frontAndBackId))
1345	{
1346	sumBalancedViewCells -= 1.0;
1347
1348	if (viewCell->mMailbox != frontId)
1349	viewCell->mMailbox = backId;
1350	else
1351	viewCell->mMailbox = frontAndBackId;
1352
1353	++ totalViewCells;
1354	}
1355	}
1356	}
1357	}
1358
1359	const float polysSize = (float)polys.size() + Limits::Small;
1360
1361	// all values should be approx. between 0 and 1 so they can be combined
1362	// and scaled with the factors according to their importance
1363	if (mSplitPlaneStrategy & BALANCED_POLYS)
1364	val += mBalancedPolysFactor * fabs(sumBalancedPolys) / polysSize;
1365
1366	if (mSplitPlaneStrategy & LEAST_SPLITS)
1367	val += mLeastSplitsFactor * sumSplits / polysSize;
1368
1369	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
1370	// HACK: polys.size should be total area so scaling is between 0 and 1
1371	val += mLargestPolyAreaFactor * (float)polys.size() / sumPolyArea;
1372
1373	if (mSplitPlaneStrategy & BLOCKED_RAYS)
1374	if (totalBlockedRays != 0)
1375	val += mBlockedRaysFactor * (totalBlockedRays - sumBlockedRays) / totalBlockedRays;
1376
1377	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
1378	val += mBalancedViewCellsFactor * fabs(sumBalancedViewCells) /
1379	((float)totalViewCells + Limits::Small);
1380
1381	return val;
1382	}
1383
1384	bool BspTree::BoundRay(const Ray &ray, float &minT, float &maxT) const
1385	{
1386	maxT = 1e6;
1387	minT = 0;
1388
1389	// test with tree bounding box
1390	if (!mBox.GetMinMaxT(ray, &minT, &maxT))
1391	return false;
1392
1393	if (minT < 0) // start ray from origin
1394	minT = 0;
1395
1396	// bound ray or line segment
1397	if ((ray.GetType() == Ray::LOCAL_RAY) &&
1398	!ray.intersections.empty() &&
1399	(ray.intersections[0].mT <= maxT))
1400	{
1401	maxT = ray.intersections[0].mT;
1402	}
1403
1404	return true;
1405	}
1406
1407	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1408	const BoundedRayContainer &rays,
1409	const int pvs,
1410	const float area,
1411	const BspNodeGeometry &cell) const
1412	{
1413	float val = 0;
1414
1415	float sumBalancedRays = 0;
1416	float sumRaySplits = 0;
1417
1418	int backId = 0;
1419	int frontId = 0;
1420	int frontAndBackId = 0;
1421
1422	int frontPvs = 0;
1423	int backPvs = 0;
1424
1425	// probability that view point lies in child
1426	float pOverall = 0;
1427	float pFront = 0;
1428	float pBack = 0;
1429
1430	if (mSplitPlaneStrategy & PVS)
1431	{
1432	// create three unique ids for pvs heuristics
1433	Intersectable::NewMail(); backId = ViewCell::sMailId;
1434	Intersectable::NewMail(); frontId = ViewCell::sMailId;
1435	Intersectable::NewMail(); frontAndBackId = ViewCell::sMailId;
1436
1437	if (mPvsUseArea) // use front and back cell areas to approximate volume
1438	{
1439	// construct child geometry with regard to the candidate split plane
1440	BspNodeGeometry frontCell;
1441	BspNodeGeometry backCell;
1442
1443	cell.SplitGeometry(frontCell, backCell, *this, candidatePlane);
1444
1445	pFront = frontCell.GetArea();
1446	pBack = backCell.GetArea();
1447
1448	pOverall = area;
1449	}
1450	}
1451
1452	BoundedRayContainer::const_iterator rit, rit_end = rays.end();
1453
1454	for (rit = rays.begin(); rit != rays.end(); ++ rit)
1455	{
1456	Ray ray = (rit)->mRay;
1457	const float minT = (*rit)->mMinT;
1458	const float maxT = (*rit)->mMaxT;
1459
1460	Vector3 entP, extP;
1461
1462	const int cf =
1463	ray->ClassifyPlane(candidatePlane, minT, maxT, entP, extP);
1464
1465	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
1466	{
1467	sumBalancedRays += sBalancedRaysTable[cf];
1468	}
1469
1470	if (mSplitPlaneStrategy & BALANCED_RAYS)
1471	{
1472	sumRaySplits += sLeastRaySplitsTable[cf];
1473	}
1474
1475	if (mSplitPlaneStrategy & PVS)
1476	{
1477	if (!ray->intersections.empty())
1478	{
1479	// in case the ray intersects an objcrs
1480	// assure that we only count a object
1481	// once for the front and once for the back side of the plane
1482	IncPvs(*ray->intersections[0].mObject, frontPvs, backPvs,
1483	cf, frontId, backId, frontAndBackId);
1484	}
1485
1486	// the source object in the origin of the ray
1487	if (ray->sourceObject.mObject)
1488	{
1489	IncPvs(*ray->sourceObject.mObject, frontPvs, backPvs,
1490	cf, frontId, backId, frontAndBackId);
1491	}
1492
1493	if (!mPvsUseArea) // use front and back cell areas to approximate volume
1494	{
1495	float len = Distance(entP, extP);
1496	pOverall += len;
1497
1498	// use length of rays to approximate volume
1499	switch (cf)
1500	{
1501	case Ray::COINCIDENT:
1502	pBack += len;
1503	pFront += len;
1504	break;
1505	case Ray::BACK:
1506	pBack += len;
1507	break;
1508	case Ray::FRONT:
1509	pFront += len;
1510	break;
1511	case Ray::FRONT_BACK:
1512	{
1513	// find intersection of ray segment with plane
1514	const Vector3 extp = ray->Extrap(maxT);
1515	const float t = candidatePlane.FindT(ray->GetLoc(), extp);
1516
1517	const float newT = t * maxT;
1518	float newLen = Distance(ray->Extrap(newT), extp);
1519
1520	pFront += len - newLen;
1521	pBack += newLen;
1522	}
1523	break;
1524	case Ray::BACK_FRONT:
1525	{
1526	// find intersection of ray segment with plane
1527	const Vector3 extp = ray->Extrap(maxT);
1528	const float t = candidatePlane.FindT(ray->GetLoc(), extp);
1529
1530	const float newT = t * maxT;
1531	float newLen = Distance(ray->Extrap(newT), extp);
1532
1533	pFront += len;
1534	pBack += len - newLen;
1535	}
1536	break;
1537	default:
1538	Debug << "Should not come here" << endl;
1539	break;
1540	}
1541	}
1542	}
1543	}
1544
1545	const float raysSize = (float)rays.size() + Limits::Small;
1546	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
1547	val += mLeastRaySplitsFactor * sumRaySplits / raysSize;
1548
1549	if (mSplitPlaneStrategy & BALANCED_RAYS)
1550	val += mBalancedRaysFactor * fabs(sumBalancedRays) / raysSize;
1551
1552	float denom = pOverall * (float)pvs * 2.0f + Limits::Small;
1553	if ((mSplitPlaneStrategy & PVS) && area && pvs)
1554	{
1555	val += mPvsFactor * (frontPvs * pFront + (backPvs * pBack)) / denom;
1556
1557	// give penalty to unbalanced split
1558	if (0)
1559	if (((pFront * 0.2 + Limits::Small) > pBack) \|\| (pFront < (pBack * 0.2 + Limits::Small)))
1560	val += 0.5;
1561	}
1562
1563	#ifdef _DEBUG
1564	Debug << "totalpvs: " << pvs << " ptotal: " << pOverall
1565	<< " frontpvs: " << frontPvs << " pFront: " << pFront
1566	<< " backpvs: " << backPvs << " pBack: " << pBack << endl << endl;
1567	#endif
1568	return val;
1569	}
1570
1571	void BspTree::IncPvs(Intersectable &obj,
1572	int &frontPvs,
1573	int &backPvs,
1574	const int cf,
1575	const int frontId,
1576	const int backId,
1577	const int frontAndBackId) const
1578	{
1579	// TODO: does this really belong to no pvs?
1580	//if (cf == Ray::COINCIDENT) return;
1581
1582	if (cf == Ray::FRONT)
1583	{
1584	if ((obj.mMailbox != frontId) &&
1585	(obj.mMailbox != frontAndBackId))
1586	{
1587	++ frontPvs;
1588
1589	if (obj.mMailbox != backId)
1590	obj.mMailbox = frontId;
1591	else
1592	obj.mMailbox = frontAndBackId;
1593	}
1594	}
1595	else if (cf == Ray::BACK)
1596	{
1597	if ((obj.mMailbox != backId) &&
1598	(obj.mMailbox != frontAndBackId))
1599	{
1600	++ backPvs;
1601
1602	if (obj.mMailbox != frontId)
1603	obj.mMailbox = backId;
1604	else
1605	obj.mMailbox = frontAndBackId;
1606	}
1607	}
1608	// object belongs to both PVS
1609	else if ((cf == Ray::FRONT_BACK) \|\| (cf == Ray::BACK_FRONT) \|\|(cf == Ray::COINCIDENT))
1610	{
1611	if (obj.mMailbox != frontAndBackId)
1612	{
1613	if (obj.mMailbox != frontId)
1614	++ frontPvs;
1615	if (obj.mMailbox != backId)
1616	++ backPvs;
1617
1618	obj.mMailbox = frontAndBackId;
1619	}
1620	}
1621	}
1622
1623	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1624	BspTraversalData &data) const
1625	{
1626	float val = 0;
1627
1628	if (mSplitPlaneStrategy & VERTICAL_AXIS)
1629	{
1630	Vector3 tinyAxis(0,0,0); tinyAxis[mBox.Size().TinyAxis()] = 1.0f;
1631	// we put a penalty on the dot product between the "tiny" vertical axis
1632	// and the split plane axis
1633	val += mVerticalSplitsFactor *
1634	fabs(DotProd(candidatePlane.mNormal, tinyAxis));
1635	}
1636
1637	// the following criteria loop over all polygons to find the cost value
1638	if ((mSplitPlaneStrategy & BALANCED_POLYS) \|\|
1639	(mSplitPlaneStrategy & LEAST_SPLITS) \|\|
1640	(mSplitPlaneStrategy & LARGEST_POLY_AREA) \|\|
1641	(mSplitPlaneStrategy & BALANCED_VIEW_CELLS) \|\|
1642	(mSplitPlaneStrategy & BLOCKED_RAYS))
1643	{
1644	val += SplitPlaneCost(candidatePlane, *data.mPolygons);
1645	}
1646
1647	// the following criteria loop over all rays to find the cost value
1648	if ((mSplitPlaneStrategy & BALANCED_RAYS) \|\|
1649	(mSplitPlaneStrategy & LEAST_RAY_SPLITS) \|\|
1650	(mSplitPlaneStrategy & PVS))
1651	{
1652	val += SplitPlaneCost(candidatePlane, *data.mRays, data.mPvs,
1653	data.mArea, *data.mGeometry);
1654	}
1655
1656	// return linear combination of the sums
1657	return val;
1658	}
1659
1660	void BspTree::CollectLeaves(vector<BspLeaf *> &leaves) const
1661	{
1662	stack<BspNode *> nodeStack;
1663	nodeStack.push(mRoot);
1664
1665	while (!nodeStack.empty())
1666	{
1667	BspNode *node = nodeStack.top();
1668
1669	nodeStack.pop();
1670
1671	if (node->IsLeaf())
1672	{
1673	BspLeaf leaf = (BspLeaf )node;
1674	leaves.push_back(leaf);
1675	}
1676	else
1677	{
1678	BspInterior interior = dynamic_cast<BspInterior >(node);
1679
1680	nodeStack.push(interior->GetBack());
1681	nodeStack.push(interior->GetFront());
1682	}
1683	}
1684	}
1685
1686	AxisAlignedBox3 BspTree::GetBoundingBox() const
1687	{
1688	return mBox;
1689	}
1690
1691	BspNode *BspTree::GetRoot() const
1692	{
1693	return mRoot;
1694	}
1695
1696	void BspTree::EvaluateLeafStats(const BspTraversalData &data)
1697	{
1698	// the node became a leaf -> evaluate stats for leafs
1699	BspLeaf leaf = dynamic_cast<BspLeaf >(data.mNode);
1700
1701	if (data.mDepth >= mTermMaxDepth)
1702	++ mStat.maxDepthNodes;
1703
1704	// store maximal and minimal depth
1705	if (data.mDepth > mStat.maxDepth)
1706	mStat.maxDepth = data.mDepth;
1707
1708	if (data.mDepth < mStat.minDepth)
1709	mStat.minDepth = data.mDepth;
1710
1711	// accumulate depth to compute average depth
1712	mStat.accumDepth += data.mDepth;
1713
1714	#ifdef _DEBUG
1715	Debug << "BSP stats: "
1716	<< "Depth: " << data.mDepth << " (max: " << mTermMaxDepth << "), "
1717	<< "PVS: " << data.mPvs << " (min: " << mTermMinPvs << "), "
1718	<< "Area: " << data.mArea << " (min: " << mTermMinArea << "), "
1719	<< "#polygons: " << (int)data.mPolygons->size() << " (max: " << mTermMaxPolygons << "), "
1720	<< "#rays: " << (int)data.mRays->size() << " (max: " << mTermMaxRays << "), "
1721	<< "#pvs: " << leaf->GetViewCell()->GetPvs().GetSize() << "=, "
1722	<< "#avg ray contrib (pvs): " << (float)data.mPvs / (float)data.mRays->size() << endl;
1723	#endif
1724	}
1725
1726	int BspTree::CastRay(Ray &ray)
1727	{
1728	int hits = 0;
1729
1730	stack<BspRayTraversalData> tStack;
1731
1732	float maxt, mint;
1733
1734	if (!BoundRay(ray, mint, maxt))
1735	return 0;
1736
1737	Intersectable::NewMail();
1738
1739	Vector3 entp = ray.Extrap(mint);
1740	Vector3 extp = ray.Extrap(maxt);
1741
1742	BspNode *node = mRoot;
1743	BspNode *farChild = NULL;
1744
1745	while (1)
1746	{
1747	if (!node->IsLeaf())
1748	{
1749	BspInterior in = (BspInterior ) node;
1750
1751	Plane3 *splitPlane = in->GetPlane();
1752
1753	int entSide = splitPlane->Side(entp);
1754	int extSide = splitPlane->Side(extp);
1755
1756	Vector3 intersection;
1757
1758	if (entSide < 0)
1759	{
1760	node = in->GetBack();
1761
1762	if(extSide <= 0) // plane does not split ray => no far child
1763	continue;
1764
1765	farChild = in->GetFront(); // plane splits ray
1766
1767	} else if (entSide > 0)
1768	{
1769	node = in->GetFront();
1770
1771	if (extSide >= 0) // plane does not split ray => no far child
1772	continue;
1773
1774	farChild = in->GetBack(); // plane splits ray
1775	}
1776	else // ray and plane are coincident
1777	{
1778	// WHAT TO DO IN THIS CASE ?
1779	//break;
1780	node = in->GetFront();
1781	continue;
1782	}
1783
1784	// push data for far child
1785	tStack.push(BspRayTraversalData(farChild, extp, maxt));
1786
1787	// find intersection of ray segment with plane
1788	float t;
1789	extp = splitPlane->FindIntersection(ray.GetLoc(), extp, &t);
1790	maxt *= t;
1791
1792	} else // reached leaf => intersection with view cell
1793	{
1794	BspLeaf leaf = dynamic_cast<BspLeaf >(node);
1795
1796	if (!leaf->mViewCell->Mailed())
1797	{
1798	ray.bspIntersections.push_back(Ray::BspIntersection(maxt, leaf));
1799	leaf->mViewCell->Mail();
1800	++ hits;
1801	}
1802
1803	//-- fetch the next far child from the stack
1804	if (tStack.empty())
1805	break;
1806
1807	entp = extp;
1808	mint = maxt; // NOTE: need this?
1809
1810	if (ray.GetType() == Ray::LINE_SEGMENT && mint > 1.0f)
1811	break;
1812
1813	BspRayTraversalData &s = tStack.top();
1814
1815	node = s.mNode;
1816	extp = s.mExitPoint;
1817	maxt = s.mMaxT;
1818
1819	tStack.pop();
1820	}
1821	}
1822
1823	return hits;
1824	}
1825
1826	bool BspTree::Export(const string filename)
1827	{
1828	Exporter *exporter = Exporter::GetExporter(filename);
1829
1830	if (exporter)
1831	{
1832	exporter->ExportBspTree(*this);
1833	return true;
1834	}
1835
1836	return false;
1837	}
1838
1839	void BspTree::CollectViewCells(ViewCellContainer &viewCells) const
1840	{
1841	stack<BspNode *> nodeStack;
1842	nodeStack.push(mRoot);
1843
1844	ViewCell::NewMail();
1845
1846	while (!nodeStack.empty())
1847	{
1848	BspNode *node = nodeStack.top();
1849	nodeStack.pop();
1850
1851	if (node->IsLeaf())
1852	{
1853	ViewCell viewCell = dynamic_cast<BspLeaf >(node)->mViewCell;
1854
1855	if (!viewCell->Mailed())
1856	{
1857	viewCell->Mail();
1858	viewCells.push_back(viewCell);
1859	}
1860	}
1861	else
1862	{
1863	BspInterior interior = dynamic_cast<BspInterior >(node);
1864
1865	nodeStack.push(interior->mFront);
1866	nodeStack.push(interior->mBack);
1867	}
1868	}
1869	}
1870
1871	void BspTree::EvaluateViewCellsStats(BspViewCellsStatistics &stat) const
1872	{
1873	stat.Reset();
1874
1875	stack<BspNode *> nodeStack;
1876	nodeStack.push(mRoot);
1877
1878	ViewCell::NewMail();
1879
1880	// exclude root cell
1881	mRootCell->Mail();
1882
1883	while (!nodeStack.empty())
1884	{
1885	BspNode *node = nodeStack.top();
1886	nodeStack.pop();
1887
1888	if (node->IsLeaf())
1889	{
1890	++ stat.bspLeaves;
1891
1892	BspViewCell viewCell = dynamic_cast<BspLeaf >(node)->mViewCell;
1893
1894	if (!viewCell->Mailed())
1895	{
1896	viewCell->Mail();
1897
1898	++ stat.viewCells;
1899	const int pvsSize = viewCell->GetPvs().GetSize();
1900
1901	stat.pvs += pvsSize;
1902
1903	if (pvsSize < 1)
1904	++ stat.emptyPvs;
1905
1906	if (pvsSize > stat.maxPvs)
1907	stat.maxPvs = pvsSize;
1908
1909	if (pvsSize < stat.minPvs)
1910	stat.minPvs = pvsSize;
1911
1912	if ((int)viewCell->mBspLeaves.size() > stat.maxBspLeaves)
1913	stat.maxBspLeaves = (int)viewCell->mBspLeaves.size();
1914	}
1915	}
1916	else
1917	{
1918	BspInterior interior = dynamic_cast<BspInterior >(node);
1919
1920	nodeStack.push(interior->mFront);
1921	nodeStack.push(interior->mBack);
1922	}
1923	}
1924	}
1925
1926	bool BspTree::MergeViewCells(BspLeaf front, BspLeaf back) const
1927	{
1928	BspViewCell *viewCell =
1929	dynamic_cast<BspViewCell >(ViewCell::Merge(front->mViewCell, *back->mViewCell));
1930
1931	if (!viewCell)
1932	return false;
1933
1934	// change view cells of all leaves associated with the
1935	// previous view cells
1936
1937	BspViewCell *fVc = front->mViewCell;
1938	BspViewCell *bVc = back->mViewCell;
1939
1940	vector<BspLeaf *> fLeaves = fVc->mBspLeaves;
1941	vector<BspLeaf *> bLeaves = bVc->mBspLeaves;
1942
1943	vector<BspLeaf *>::const_iterator it;
1944
1945	for (it = fLeaves.begin(); it != fLeaves.end(); ++ it)
1946	{
1947	(*it)->SetViewCell(viewCell);
1948	viewCell->mBspLeaves.push_back(*it);
1949	}
1950	for (it = bLeaves.begin(); it != bLeaves.end(); ++ it)
1951	{
1952	(*it)->SetViewCell(viewCell);
1953	viewCell->mBspLeaves.push_back(*it);
1954	}
1955
1956	DEL_PTR(fVc);
1957	DEL_PTR(bVc);
1958
1959	return true;
1960	}
1961
1962	bool BspTree::ShouldMerge(BspLeaf front, BspLeaf back) const
1963	{
1964	ViewCell *fvc = front->mViewCell;
1965	ViewCell *bvc = back->mViewCell;
1966
1967	if ((fvc == mRootCell) \|\| (bvc == mRootCell) \|\| (fvc == bvc))
1968	return false;
1969
1970	int fdiff = fvc->GetPvs().Diff(bvc->GetPvs());
1971
1972	if (fvc->GetPvs().GetSize() + fdiff < mMaxPvs)
1973	{
1974	if ((fvc->GetPvs().GetSize() < mMinPvs) \|\|
1975	(bvc->GetPvs().GetSize() < mMinPvs) \|\|
1976	((fdiff < mMinPvsDif) && (bvc->GetPvs().Diff(fvc->GetPvs()) < mMinPvsDif)))
1977	{
1978	return true;
1979	}
1980	}
1981
1982	return false;
1983	}
1984
1985	void BspTree::SetGenerateViewCells(int generateViewCells)
1986	{
1987	mGenerateViewCells = generateViewCells;
1988	}
1989
1990	BspTreeStatistics &BspTree::GetStat()
1991	{
1992	return mStat;
1993	}
1994
1995	float BspTree::AccumulatedRayLength(BoundedRayContainer &rays) const
1996	{
1997	float len = 0;
1998
1999	BoundedRayContainer::const_iterator it, it_end = rays.end();
2000
2001	for (it = rays.begin(); it != it_end; ++ it)
2002	{
2003	len += SqrDistance((it)->mRay->Extrap((it)->mMinT),
2004	(it)->mRay->Extrap((it)->mMaxT));
2005	}
2006
2007	return len;
2008	}
2009
2010	int BspTree::SplitRays(const Plane3 &plane,
2011	BoundedRayContainer &rays,
2012	BoundedRayContainer &frontRays,
2013	BoundedRayContainer &backRays)
2014	{
2015	int splits = 0;
2016
2017	while (!rays.empty())
2018	{
2019	BoundedRay *bRay = rays.back();
2020	Ray *ray = bRay->mRay;
2021	float minT = bRay->mMinT;
2022	float maxT = bRay->mMaxT;
2023
2024	rays.pop_back();
2025
2026	Vector3 entP, extP;
2027
2028	const int cf =
2029	ray->ClassifyPlane(plane, minT, maxT, entP, extP);
2030
2031	// set id to ray classification
2032	ray->SetId(cf);
2033
2034	switch (cf)
2035	{
2036	case Ray::COINCIDENT: // TODO: should really discard ray?
2037	frontRays.push_back(bRay);
2038	//DEL_PTR(bRay);
2039	break;
2040	case Ray::BACK:
2041	backRays.push_back(bRay);
2042	break;
2043	case Ray::FRONT:
2044	frontRays.push_back(bRay);
2045	break;
2046	case Ray::FRONT_BACK:
2047	{
2048	// find intersection of ray segment with plane
2049	const float t = plane.FindT(ray->GetLoc(), extP);
2050
2051	const float newT = t * maxT;
2052
2053	frontRays.push_back(new BoundedRay(ray, minT, newT));
2054	backRays.push_back(new BoundedRay(ray, newT, maxT));
2055
2056	DEL_PTR(bRay);
2057	}
2058	break;
2059	case Ray::BACK_FRONT:
2060	{
2061	// find intersection of ray segment with plane
2062	const float t = plane.FindT(ray->GetLoc(), extP);
2063	const float newT = t * bRay->mMaxT;
2064
2065	backRays.push_back(new BoundedRay(ray, bRay->mMinT, newT));
2066	frontRays.push_back(new BoundedRay(ray, newT, bRay->mMaxT));
2067	DEL_PTR(bRay);
2068
2069	++ splits;
2070	}
2071	break;
2072	default:
2073	Debug << "Should not come here" << endl;
2074	break;
2075	}
2076	}
2077
2078	return splits;
2079	}
2080
2081	void BspTree::ExtractHalfSpaces(BspNode *n, vector<Plane3> &halfSpaces) const
2082	{
2083	BspNode *lastNode;
2084	do
2085	{
2086	lastNode = n;
2087
2088	// want to get planes defining geometry of this node => don't take
2089	// split plane of node itself
2090	n = n->GetParent();
2091
2092	if (n)
2093	{
2094	BspInterior interior = dynamic_cast<BspInterior >(n);
2095	Plane3 halfSpace = dynamic_cast<BspInterior >(interior)->GetPlane();
2096
2097	if (interior->mFront != lastNode)
2098	halfSpace.ReverseOrientation();
2099
2100	halfSpaces.push_back(halfSpace);
2101	}
2102	}
2103	while (n);
2104	}
2105
2106	void BspTree::ConstructGeometry(BspNode *n, BspNodeGeometry &cell) const
2107	{
2108	PolygonContainer polys;
2109	ConstructGeometry(n, polys);
2110	cell.mPolys = polys;
2111	}
2112
2113	void BspTree::ConstructGeometry(BspViewCell *vc, PolygonContainer &cell) const
2114	{
2115	vector<BspLeaf *> leaves = vc->mBspLeaves;
2116
2117	vector<BspLeaf *>::const_iterator it, it_end = leaves.end();
2118
2119	for (it = leaves.begin(); it != it_end; ++ it)
2120	ConstructGeometry(*it, cell);
2121	}
2122
2123
2124	void BspTree::ConstructGeometry(BspNode *n, PolygonContainer &cell) const
2125	{
2126	vector<Plane3> halfSpaces;
2127	ExtractHalfSpaces(n, halfSpaces);
2128
2129	PolygonContainer candidatePolys;
2130
2131	// bounded planes are added to the polygons (reverse polygons
2132	// as they have to be outfacing
2133	for (int i = 0; i < (int)halfSpaces.size(); ++ i)
2134	{
2135	Polygon3 *p = GetBoundingBox().CrossSection(halfSpaces[i]);
2136
2137	if (p->Valid())
2138	{
2139	candidatePolys.push_back(p->CreateReversePolygon());
2140	DEL_PTR(p);
2141	}
2142	}
2143
2144	// add faces of bounding box (also could be faces of the cell)
2145	for (int i = 0; i < 6; ++ i)
2146	{
2147	VertexContainer vertices;
2148
2149	for (int j = 0; j < 4; ++ j)
2150	vertices.push_back(mBox.GetFace(i).mVertices[j]);
2151
2152	candidatePolys.push_back(new Polygon3(vertices));
2153	}
2154
2155	for (int i = 0; i < (int)candidatePolys.size(); ++ i)
2156	{
2157	// polygon is split by all other planes
2158	for (int j = 0; (j < (int)halfSpaces.size()) && candidatePolys[i]; ++ j)
2159	{
2160	if (i == j) // polygon and plane are coincident
2161	continue;
2162
2163	VertexContainer splitPts;
2164	Polygon3 frontPoly, backPoly;
2165
2166	const int cf = candidatePolys[i]->ClassifyPlane(halfSpaces[j]);
2167
2168	switch (cf)
2169	{
2170	case Polygon3::SPLIT:
2171	frontPoly = new Polygon3();
2172	backPoly = new Polygon3();
2173
2174	candidatePolys[i]->Split(halfSpaces[j], *frontPoly,
2175	*backPoly, splitPts);
2176
2177	DEL_PTR(candidatePolys[i]);
2178
2179	if (frontPoly->Valid())
2180	candidatePolys[i] = frontPoly;
2181	else
2182	DEL_PTR(frontPoly);
2183
2184	DEL_PTR(backPoly);
2185	break;
2186	case Polygon3::BACK_SIDE:
2187	DEL_PTR(candidatePolys[i]);
2188	break;
2189	// just take polygon as it is
2190	case Polygon3::FRONT_SIDE:
2191	case Polygon3::COINCIDENT:
2192	default:
2193	break;
2194	}
2195	}
2196
2197	if (candidatePolys[i])
2198	cell.push_back(candidatePolys[i]);
2199	}
2200	}
2201
2202
2203	int BspTree::FindNeighbors(BspNode n, vector<BspLeaf > &neighbors,
2204	const bool onlyUnmailed) const
2205	{
2206	PolygonContainer cell;
2207
2208	ConstructGeometry(n, cell);
2209
2210	stack<BspNode *> nodeStack;
2211	nodeStack.push(mRoot);
2212
2213	// planes needed to verify that we found neighbor leaf.
2214	vector<Plane3> halfSpaces;
2215	ExtractHalfSpaces(n, halfSpaces);
2216
2217	while (!nodeStack.empty())
2218	{
2219	BspNode *node = nodeStack.top();
2220	nodeStack.pop();
2221
2222	if (node->IsLeaf())
2223	{
2224	if (node != n && (!onlyUnmailed \|\| !node->Mailed()))
2225	{
2226	// test all planes of current node if candidate really
2227	// is neighbour
2228	PolygonContainer neighborCandidate;
2229	ConstructGeometry(node, neighborCandidate);
2230
2231	bool isAdjacent = true;
2232	for (int i = 0; (i < halfSpaces.size()) && isAdjacent; ++ i)
2233	{
2234	const int cf =
2235	Polygon3::ClassifyPlane(neighborCandidate, halfSpaces[i]);
2236
2237	if (cf == Polygon3::BACK_SIDE)
2238	isAdjacent = false;
2239	}
2240
2241	if (isAdjacent)
2242	neighbors.push_back(dynamic_cast<BspLeaf *>(node));
2243
2244	CLEAR_CONTAINER(neighborCandidate);
2245	}
2246	}
2247	else
2248	{
2249	BspInterior interior = dynamic_cast<BspInterior >(node);
2250
2251	const int cf = Polygon3::ClassifyPlane(cell, interior->mPlane);
2252
2253	if (cf == Polygon3::FRONT_SIDE)
2254	nodeStack.push(interior->mFront);
2255	else
2256	if (cf == Polygon3::BACK_SIDE)
2257	nodeStack.push(interior->mBack);
2258	else
2259	{
2260	// random decision
2261	nodeStack.push(interior->mBack);
2262	nodeStack.push(interior->mFront);
2263	}
2264	}
2265	}
2266
2267	CLEAR_CONTAINER(cell);
2268	return (int)neighbors.size();
2269	}
2270
2271	BspLeaf *BspTree::GetRandomLeaf(const Plane3 &halfspace)
2272	{
2273	stack<BspNode *> nodeStack;
2274	nodeStack.push(mRoot);
2275
2276	int mask = rand();
2277
2278	while (!nodeStack.empty())
2279	{
2280	BspNode *node = nodeStack.top();
2281	nodeStack.pop();
2282
2283	if (node->IsLeaf())
2284	{
2285	return dynamic_cast<BspLeaf *>(node);
2286	}
2287	else
2288	{
2289	BspInterior interior = dynamic_cast<BspInterior >(node);
2290
2291	BspNode *next;
2292
2293	PolygonContainer cell;
2294
2295	// todo: not very efficient: constructs full cell everytime
2296	ConstructGeometry(interior, cell);
2297
2298	const int cf = Polygon3::ClassifyPlane(cell, halfspace);
2299
2300	if (cf == Polygon3::BACK_SIDE)
2301	next = interior->mFront;
2302	else
2303	if (cf == Polygon3::FRONT_SIDE)
2304	next = interior->mFront;
2305	else
2306	{
2307	// random decision
2308	if (mask & 1)
2309	next = interior->mBack;
2310	else
2311	next = interior->mFront;
2312	mask = mask >> 1;
2313	}
2314
2315	nodeStack.push(next);
2316	}
2317	}
2318
2319	return NULL;
2320	}
2321
2322	BspLeaf *BspTree::GetRandomLeaf(const bool onlyUnmailed)
2323	{
2324	stack<BspNode *> nodeStack;
2325
2326	nodeStack.push(mRoot);
2327
2328	int mask = rand();
2329
2330	while (!nodeStack.empty())
2331	{
2332	BspNode *node = nodeStack.top();
2333	nodeStack.pop();
2334
2335	if (node->IsLeaf())
2336	{
2337	if ( (!onlyUnmailed \|\| !node->Mailed()) )
2338	return dynamic_cast<BspLeaf *>(node);
2339	}
2340	else
2341	{
2342	BspInterior interior = dynamic_cast<BspInterior >(node);
2343
2344	// random decision
2345	if (mask & 1)
2346	nodeStack.push(interior->mBack);
2347	else
2348	nodeStack.push(interior->mFront);
2349
2350	mask = mask >> 1;
2351	}
2352	}
2353
2354	return NULL;
2355	}
2356
2357	int BspTree::ComputePvsSize(const BoundedRayContainer &rays) const
2358	{
2359	int pvsSize = 0;
2360
2361	BoundedRayContainer::const_iterator rit, rit_end = rays.end();
2362
2363	Intersectable::NewMail();
2364
2365	for (rit = rays.begin(); rit != rays.end(); ++ rit)
2366	{
2367	Ray ray = (rit)->mRay;
2368
2369	if (!ray->intersections.empty())
2370	{
2371	if (!ray->intersections[0].mObject->Mailed())
2372	{
2373	ray->intersections[0].mObject->Mail();
2374	++ pvsSize;
2375	}
2376	}
2377	if (ray->sourceObject.mObject)
2378	{
2379	if (!ray->sourceObject.mObject->Mailed())
2380	{
2381	ray->sourceObject.mObject->Mail();
2382	++ pvsSize;
2383	}
2384	}
2385	}
2386
2387	return pvsSize;
2388	}
2389
2390	/*************************************************************
2391	* BspNodeGeometry Implementation *
2392	*************************************************************/
2393
2394	BspNodeGeometry::~BspNodeGeometry()
2395	{
2396	CLEAR_CONTAINER(mPolys);
2397	}
2398
2399	float BspNodeGeometry::GetArea() const
2400	{
2401	return Polygon3::GetArea(mPolys);
2402	}
2403
2404	void BspNodeGeometry::SplitGeometry(BspNodeGeometry &front,
2405	BspNodeGeometry &back,
2406	const BspTree &tree,
2407	const Plane3 &splitPlane) const
2408	{
2409	// get cross section of new polygon
2410	Polygon3 *planePoly = tree.GetBoundingBox().CrossSection(splitPlane);
2411
2412	planePoly = SplitPolygon(planePoly, tree);
2413
2414	//-- plane poly splits all other cell polygons
2415	for (int i = 0; i < (int)mPolys.size(); ++ i)
2416	{
2417	const int cf = mPolys[i]->ClassifyPlane(splitPlane, 0.00001f);
2418
2419	// split new polygon with all previous planes
2420	switch (cf)
2421	{
2422	case Polygon3::SPLIT:
2423	{
2424	Polygon3 *poly = new Polygon3(mPolys[i]->mVertices);
2425
2426	Polygon3 *frontPoly = new Polygon3();
2427	Polygon3 *backPoly = new Polygon3();
2428
2429	VertexContainer splitPts;
2430
2431	poly->Split(splitPlane, frontPoly, backPoly, splitPts);
2432
2433	DEL_PTR(poly);
2434
2435	if (frontPoly->Valid())
2436	front.mPolys.push_back(frontPoly);
2437	if (backPoly->Valid())
2438	back.mPolys.push_back(backPoly);
2439	}
2440
2441	break;
2442	case Polygon3::BACK_SIDE:
2443	back.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
2444	break;
2445	case Polygon3::FRONT_SIDE:
2446	front.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
2447	break;
2448	case Polygon3::COINCIDENT:
2449	//front.mPolys.push_back(CreateReversePolygon(mPolys[i]));
2450	back.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
2451	break;
2452	default:
2453	break;
2454	}
2455	}
2456
2457	//-- finally add the new polygon to the child cells
2458	if (planePoly)
2459	{
2460	// add polygon with normal pointing into positive half space to back cell
2461	back.mPolys.push_back(planePoly);
2462	// add polygon with reverse orientation to front cell
2463	front.mPolys.push_back(planePoly->CreateReversePolygon());
2464	}
2465
2466	//Debug << "returning new geometry " << mPolys.size() << " f: " << front.mPolys.size() << " b: " << back.mPolys.size() << endl;
2467	//Debug << "old area " << GetArea() << " f: " << front.GetArea() << " b: " << back.GetArea() << endl;
2468	}
2469
2470	Polygon3 BspNodeGeometry::SplitPolygon(Polygon3 planePoly,
2471	const BspTree &tree) const
2472	{
2473	// polygon is split by all other planes
2474	for (int i = 0; (i < (int)mPolys.size()) && planePoly; ++ i)
2475	{
2476	Plane3 plane = mPolys[i]->GetSupportingPlane();
2477
2478	const int cf =
2479	planePoly->ClassifyPlane(plane, 0.00001f);
2480
2481	// split new polygon with all previous planes
2482	switch (cf)
2483	{
2484	case Polygon3::SPLIT:
2485	{
2486	VertexContainer splitPts;
2487
2488	Polygon3 *frontPoly = new Polygon3();
2489	Polygon3 *backPoly = new Polygon3();
2490
2491	planePoly->Split(plane, frontPoly, backPoly, splitPts);
2492	DEL_PTR(planePoly);
2493
2494	if (backPoly->Valid())
2495	planePoly = backPoly;
2496	else
2497	DEL_PTR(backPoly);
2498	}
2499	break;
2500	case Polygon3::FRONT_SIDE:
2501	DEL_PTR(planePoly);
2502	break;
2503	// polygon is taken as it is
2504	case Polygon3::BACK_SIDE:
2505	case Polygon3::COINCIDENT:
2506	default:
2507	break;
2508	}
2509	}
2510
2511	return planePoly;
2512	}
2513
2514	void BspViewCellsStatistics::Print(ostream &app) const
2515	{
2516	app << "===== BspViewCells statistics ===============\n";
2517
2518	app << setprecision(4);
2519
2520	//app << "#N_CTIME ( Construction time [s] )\n" << Time() << " \n";
2521
2522	app << "#N_OVERALLPVS ( objects in PVS )\n" << pvs << endl;
2523
2524	app << "#N_PMAXPVS ( largest PVS )\n" << maxPvs << endl;
2525
2526	app << "#N_PMINPVS ( smallest PVS )\n" << minPvs << endl;
2527
2528	app << "#N_PAVGPVS ( average PVS )\n" << AvgPvs() << endl;
2529
2530	app << "#N_PEMPTYPVS ( view cells with PVS smaller 2 )\n" << emptyPvs << endl;
2531
2532	app << "#N_VIEWCELLS ( number of view cells)\n" << viewCells << endl;
2533
2534	app << "#N_AVGBSPLEAVES (average number of BSP leaves per view cell )\n" << AvgBspLeaves() << endl;
2535
2536	app << "#N_MAXBSPLEAVES ( maximal number of BSP leaves per view cell )\n" << maxBspLeaves << endl;
2537
2538	app << "===== END OF BspViewCells statistics ==========\n";
2539	}

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