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source: trunk/VUT/GtpVisibilityPreprocessor/src/ViewCellBsp.cpp @ 423

Revision 423, 61.7 KB checked in by mattausch, 19 years ago (diff)
proceeding with the kd view space partition

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

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