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source: trunk/VUT/GtpVisibilityPreprocessor/src/ViewCellBsp.cpp @ 610

Revision 610, 75.1 KB checked in by mattausch, 18 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 "Triangle3.h"
11	#include "Tetrahedron3.h"
12	#include "ViewCellsManager.h"
13	#include "Exporter.h"
14	#include "Plane3.h"
15	#include <stack>
16
17
18
19	//-- static members
20
21	int BspNode::sMailId = 1;
22
23	/** Evaluates split plane classification with respect to the plane's
24	contribution for a minimum number splits in the tree.
25	*/
26	const float BspTree::sLeastPolySplitsTable[] = {0, 0, 1, 0};
27	/** Evaluates split plane classification with respect to the plane's
28	contribution for a balanced tree.
29	*/
30	const float BspTree::sBalancedPolysTable[] = {1, -1, 0, 0};
31
32	/** Evaluates split plane classification with respect to the plane's
33	contribution for a minimum number of ray splits.
34	*/
35	const float BspTree::sLeastRaySplitsTable[] = {0, 0, 1, 1, 0};
36	/** Evaluates split plane classification with respect to the plane's
37	contribution for balanced rays.
38	*/
39	const float BspTree::sBalancedRaysTable[] = {1, -1, 0, 0, 0};
40
41	int BspTree::sFrontId = 0;
42	int BspTree::sBackId = 0;
43	int BspTree::sFrontAndBackId = 0;
44
45
46	/****************************************************************/
47	/* class BspNode implementation */
48	/****************************************************************/
49
50
51	BspNode::BspNode():
52	mParent(NULL), mTreeValid(true), mTimeStamp(0)
53	{}
54
55	BspNode::BspNode(BspInterior *parent):
56	mParent(parent), mTreeValid(true)
57	{}
58
59
60	bool BspNode::IsRoot() const
61	{
62	return mParent == NULL;
63	}
64
65
66	BspInterior *BspNode::GetParent()
67	{
68	return mParent;
69	}
70
71
72	void BspNode::SetParent(BspInterior *parent)
73	{
74	mParent = parent;
75	}
76
77
78	bool BspNode::IsSibling(BspNode *n) const
79	{
80	return ((this != n) && mParent &&
81	(mParent->GetFront() == n) \|\| (mParent->GetBack() == n));
82	}
83
84
85	int BspNode::GetDepth() const
86	{
87	int depth = 0;
88	BspNode *p = mParent;
89
90	while (p)
91	{
92	p = p->mParent;
93	++ depth;
94	}
95
96	return depth;
97	}
98
99
100	bool BspNode::TreeValid() const
101	{
102	return mTreeValid;
103	}
104
105
106	void BspNode::SetTreeValid(const bool v)
107	{
108	mTreeValid = v;
109	}
110
111
112	/****************************************************************/
113	/* class BspInterior implementation */
114	/****************************************************************/
115
116
117	BspInterior::BspInterior(const Plane3 &plane):
118	mPlane(plane), mFront(NULL), mBack(NULL)
119	{}
120
121	BspInterior::~BspInterior()
122	{
123	DEL_PTR(mFront);
124	DEL_PTR(mBack);
125	}
126
127	bool BspInterior::IsLeaf() const
128	{
129	return false;
130	}
131
132	BspNode *BspInterior::GetBack()
133	{
134	return mBack;
135	}
136
137	BspNode *BspInterior::GetFront()
138	{
139	return mFront;
140	}
141
142	Plane3 BspInterior::GetPlane() const
143	{
144	return mPlane;
145	}
146
147	void BspInterior::ReplaceChildLink(BspNode oldChild, BspNode newChild)
148	{
149	if (mBack == oldChild)
150	mBack = newChild;
151	else
152	mFront = newChild;
153	}
154
155	void BspInterior::SetupChildLinks(BspNode b, BspNode f)
156	{
157	mBack = b;
158	mFront = f;
159	}
160
161	/****************************************************************/
162	/* class BspLeaf implementation */
163	/****************************************************************/
164
165
166	BspLeaf::BspLeaf(): mViewCell(NULL), mPvs(NULL)
167	{
168	}
169
170
171	BspLeaf::~BspLeaf()
172	{
173	DEL_PTR(mPvs);
174	}
175
176
177	BspLeaf::BspLeaf(ViewCell *viewCell):
178	mViewCell(viewCell)
179	{
180	}
181
182
183	BspLeaf::BspLeaf(BspInterior *parent):
184	BspNode(parent), mViewCell(NULL), mPvs(NULL)
185	{}
186
187
188
189	BspLeaf::BspLeaf(BspInterior parent, ViewCell viewCell):
190	BspNode(parent), mViewCell(viewCell), mPvs(NULL)
191	{
192	}
193
194	ViewCell *BspLeaf::GetViewCell() const
195	{
196	return mViewCell;
197	}
198
199	void BspLeaf::SetViewCell(ViewCell *viewCell)
200	{
201	mViewCell = viewCell;
202	}
203
204
205	bool BspLeaf::IsLeaf() const
206	{
207	return true;
208	}
209
210
211	/*********************************************************************/
212	/* class BspTree implementation */
213	/*********************************************************************/
214
215	BspTree::BspTree():
216	mRoot(NULL),
217	mUseAreaForPvs(false),
218	mGenerateViewCells(true),
219	mTimeStamp(0)
220	{
221	Randomize(); // initialise random generator for heuristics
222
223	mOutOfBoundsCell = GetOrCreateOutOfBoundsCell();
224
225	//-- termination criteria for autopartition
226	environment->GetIntValue("BspTree.Termination.maxDepth", mTermMaxDepth);
227	environment->GetIntValue("BspTree.Termination.minPvs", mTermMinPvs);
228	environment->GetIntValue("BspTree.Termination.minPolygons", mTermMinPolys);
229	environment->GetIntValue("BspTree.Termination.minRays", mTermMinRays);
230	environment->GetFloatValue("BspTree.Termination.minProbability", mTermMinProbability);
231	environment->GetFloatValue("BspTree.Termination.maxRayContribution", mTermMaxRayContribution);
232	environment->GetFloatValue("BspTree.Termination.minAccRayLenght", mTermMinAccRayLength);
233
234	//-- factors for bsp tree split plane heuristics
235	environment->GetFloatValue("BspTree.Factor.verticalSplits", mVerticalSplitsFactor);
236	environment->GetFloatValue("BspTree.Factor.largestPolyArea", mLargestPolyAreaFactor);
237	environment->GetFloatValue("BspTree.Factor.blockedRays", mBlockedRaysFactor);
238	environment->GetFloatValue("BspTree.Factor.leastRaySplits", mLeastRaySplitsFactor);
239	environment->GetFloatValue("BspTree.Factor.balancedRays", mBalancedRaysFactor);
240	environment->GetFloatValue("BspTree.Factor.pvs", mPvsFactor);
241	environment->GetFloatValue("BspTree.Factor.leastSplits" , mLeastSplitsFactor);
242	environment->GetFloatValue("BspTree.Factor.balancedPolys", mBalancedPolysFactor);
243	environment->GetFloatValue("BspTree.Factor.balancedViewCells", mBalancedViewCellsFactor);
244	environment->GetFloatValue("BspTree.Termination.ct_div_ci", mCtDivCi);
245
246	//-- termination criteria for axis aligned split
247	environment->GetFloatValue("BspTree.Termination.AxisAligned.ct_div_ci", mAxisAlignedCtDivCi);
248	environment->GetFloatValue("BspTree.Termination.maxCostRatio", mMaxCostRatio);
249	environment->GetIntValue("BspTree.Termination.AxisAligned.minPolys",
250	mTermMinPolysForAxisAligned);
251	environment->GetIntValue("BspTree.Termination.AxisAligned.minRays",
252	mTermMinRaysForAxisAligned);
253	environment->GetIntValue("BspTree.Termination.AxisAligned.minObjects",
254	mTermMinObjectsForAxisAligned);
255	//-- partition criteria
256	environment->GetIntValue("BspTree.maxPolyCandidates", mMaxPolyCandidates);
257	environment->GetIntValue("BspTree.maxRayCandidates", mMaxRayCandidates);
258	environment->GetIntValue("BspTree.splitPlaneStrategy", mSplitPlaneStrategy);
259	environment->GetFloatValue("BspTree.AxisAligned.splitBorder", mSplitBorder);
260	environment->GetIntValue("BspTree.maxTests", mMaxTests);
261	environment->GetIntValue("BspTree.Termination.maxViewCells", mMaxViewCells);
262
263	environment->GetFloatValue("BspTree.Construction.epsilon", mEpsilon);
264
265	Debug << "BSP max depth: " << mTermMaxDepth << endl;
266	Debug << "BSP min PVS: " << mTermMinPvs << endl;
267	Debug << "BSP min probability: " << mTermMinProbability << endl;
268	Debug << "BSP max polys: " << mTermMinPolys << endl;
269	Debug << "BSP max rays: " << mTermMinRays << endl;
270	Debug << "BSP max polygon candidates: " << mMaxPolyCandidates << endl;
271	Debug << "BSP max plane candidates: " << mMaxRayCandidates << endl;
272
273	Debug << "Split plane strategy: ";
274	if (mSplitPlaneStrategy & RANDOM_POLYGON)
275	Debug << "random polygon ";
276	if (mSplitPlaneStrategy & AXIS_ALIGNED)
277	Debug << "axis aligned ";
278	if (mSplitPlaneStrategy & LEAST_SPLITS)
279	Debug << "least splits ";
280	if (mSplitPlaneStrategy & BALANCED_POLYS)
281	Debug << "balanced polygons ";
282	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
283	Debug << "balanced view cells ";
284	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
285	Debug << "largest polygon area ";
286	if (mSplitPlaneStrategy & VERTICAL_AXIS)
287	Debug << "vertical axis ";
288	if (mSplitPlaneStrategy & BLOCKED_RAYS)
289	Debug << "blocked rays ";
290	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
291	Debug << "least ray splits ";
292	if (mSplitPlaneStrategy & BALANCED_RAYS)
293	Debug << "balanced rays ";
294	if (mSplitPlaneStrategy & PVS)
295	Debug << "pvs";
296
297	Debug << endl;
298	}
299
300
301	const BspTreeStatistics &BspTree::GetStatistics() const
302	{
303	return mStat;
304	}
305
306
307	int BspTree::SplitPolygons(const Plane3 &plane,
308	PolygonContainer &polys,
309	PolygonContainer &frontPolys,
310	PolygonContainer &backPolys,
311	PolygonContainer &coincident) const
312	{
313	int splits = 0;
314
315	#ifdef _Debug
316	Debug << "splitting polygons of node " << this << " with plane " << mPlane << endl;
317	#endif
318	PolygonContainer::const_iterator it, it_end = polys.end();
319
320	for (it = polys.begin(); it != polys.end(); ++ it)
321	{
322	Polygon3 poly = it;
323
324	//-- classify polygon
325	const int cf = poly->ClassifyPlane(plane, mEpsilon);
326
327	switch (cf)
328	{
329	case Polygon3::COINCIDENT:
330	coincident.push_back(poly);
331	break;
332	case Polygon3::FRONT_SIDE:
333	frontPolys.push_back(poly);
334	break;
335	case Polygon3::BACK_SIDE:
336	backPolys.push_back(poly);
337	break;
338	case Polygon3::SPLIT:
339	{
340	Polygon3 *front_piece = new Polygon3(poly->mParent);
341	Polygon3 *back_piece = new Polygon3(poly->mParent);
342
343	//-- split polygon into front and back part
344	poly->Split(plane,
345	*front_piece,
346	*back_piece,
347	mEpsilon);
348
349	++ splits; // increase number of splits
350
351	//-- inherit rays from parent polygon for blocked ray criterium
352	poly->InheritRays(front_piece, back_piece);
353
354	// check if polygons still valid
355	if (front_piece->Valid(mEpsilon))
356	frontPolys.push_back(front_piece);
357	else
358	DEL_PTR(front_piece);
359
360	if (back_piece->Valid(mEpsilon))
361	backPolys.push_back(back_piece);
362	else
363	DEL_PTR(back_piece);
364
365	#ifdef _DEBUG
366	Debug << "split " << poly << endl << front_piece << endl << *back_piece << endl;
367	#endif
368	DEL_PTR(poly);
369	}
370	break;
371	default:
372	Debug << "SHOULD NEVER COME HERE\n";
373	break;
374	}
375	}
376
377	return splits;
378	}
379
380
381	void BspTreeStatistics::Print(ostream &app) const
382	{
383	app << "===== BspTree statistics ===============\n";
384
385	app << setprecision(4);
386
387	app << "#N_CTIME ( Construction time [s] )\n" << Time() << " \n";
388
389	app << "#N_NODES ( Number of nodes )\n" << nodes << "\n";
390
391	app << "#N_INTERIORS ( Number of interior nodes )\n" << Interior() << "\n";
392
393	app << "#N_LEAVES ( Number of leaves )\n" << Leaves() << "\n";
394
395	app << "#N_POLYSPLITS ( Number of polygon splits )\n" << polySplits << "\n";
396
397	app << "#AXIS_ALIGNED_SPLITS (number of axis aligned splits)\n" << splits[0] + splits[1] + splits[2] << endl;
398
399	app << "#N_SPLITS ( Number of splits in axes x y z\n";
400
401	for (int i = 0; i < 3; ++ i)
402	app << splits[i] << " ";
403	app << endl;
404
405	app << "#N_PMAXDEPTHLEAVES ( Percentage of leaves at maximum depth )\n"
406	<< maxDepthNodes * 100 / (double)Leaves() << endl;
407
408	app << "#N_PMINPVSLEAVES ( Percentage of leaves with mininimal PVS )\n"
409	<< minPvsNodes * 100 / (double)Leaves() << endl;
410
411	app << "#N_PMINRAYSLEAVES ( Percentage of leaves with minimal number of rays)\n"
412	<< minRaysNodes * 100 / (double)Leaves() << endl;
413
414	app << "#N_MAXCOSTNODES ( Percentage of leaves with terminated because of max cost ratio )\n"
415	<< maxCostNodes * 100 / (double)Leaves() << endl;
416
417	app << "#N_PMINPROBABILITYLEAVES ( Percentage of leaves with mininum probability )\n"
418	<< minProbabilityNodes * 100 / (double)Leaves() << endl;
419
420	app << "#N_PMAXRAYCONTRIBLEAVES ( Percentage of leaves with maximal ray contribution )\n"
421	<< maxRayContribNodes * 100 / (double)Leaves() << endl;
422
423	app << "#N_PMAXDEPTH ( Maximal reached depth )\n" << maxDepth << endl;
424
425	app << "#N_PMINDEPTH ( Minimal reached depth )\n" << minDepth << endl;
426
427	app << "#AVGDEPTH ( average depth )\n" << AvgDepth() << endl;
428
429	app << "#N_INPUTPOLYGONS (number of input polygons )\n" << polys << endl;
430
431	app << "#N_INVALIDLEAVES (number of invalid leaves )\n" << invalidLeaves << endl;
432
433	app << "#N_RAYS (number of rays / leaf)\n" << AvgRays() << endl;
434	//app << "#N_PVS: " << pvs << endl;
435
436	app << "#N_ROUTPUT_INPUT_POLYGONS ( ratio polygons after subdivision / input polygons )\n" <<
437	(polys + polySplits) / (double)polys << endl;
438
439	app << "===== END OF BspTree statistics ==========\n";
440	}
441
442
443	BspTree::~BspTree()
444	{
445	DEL_PTR(mRoot);
446
447	// TODO must be deleted if used!!
448	//if (mGenerateViewCells) DEL_PTR(mOutOfBoundsCell);
449	}
450
451	BspViewCell *BspTree::GetOutOfBoundsCell()
452	{
453	return mOutOfBoundsCell;
454	}
455
456
457	BspNode *BspTree::GetRoot() const
458	{
459	return mRoot;
460	}
461
462	BspViewCell *BspTree::GetOrCreateOutOfBoundsCell()
463	{
464	if (!mOutOfBoundsCell)
465	{
466	mOutOfBoundsCell = new BspViewCell();
467	mOutOfBoundsCell->SetId(-1);
468	mOutOfBoundsCell->SetValid(false);
469	}
470
471	return mOutOfBoundsCell;
472	}
473
474
475	void BspTree::InsertViewCell(ViewCell *viewCell)
476	{
477	PolygonContainer *polys = new PolygonContainer();
478
479	// don't generate new view cell, insert this one
480	mGenerateViewCells = false;
481	// extract polygons that guide the split process
482	mStat.polys += AddMeshToPolygons(viewCell->GetMesh(), *polys, viewCell);
483	mBox.Include(viewCell->GetBox()); // add to BSP aabb
484
485	InsertPolygons(polys);
486	}
487
488
489	void BspTree::InsertPolygons(PolygonContainer *polys)
490	{
491	BspTraversalStack tStack;
492
493	// traverse existing tree or create new tree
494	if (!mRoot)
495	mRoot = new BspLeaf();
496
497	tStack.push(BspTraversalData(mRoot,
498	polys,
499	0,
500	mOutOfBoundsCell,
501	new BoundedRayContainer(),
502	0,
503	mUseAreaForPvs ? mBox.SurfaceArea() : mBox.GetVolume(),
504	new BspNodeGeometry()));
505
506	while (!tStack.empty())
507	{
508	// filter polygons donw the tree
509	BspTraversalData tData = tStack.top();
510	tStack.pop();
511
512	if (!tData.mNode->IsLeaf())
513	{
514	BspInterior interior = dynamic_cast<BspInterior >(tData.mNode);
515
516	//-- filter view cell polygons down the tree until a leaf is reached
517	if (!tData.mPolygons->empty())
518	{
519	PolygonContainer *frontPolys = new PolygonContainer();
520	PolygonContainer *backPolys = new PolygonContainer();
521	PolygonContainer coincident;
522
523	int splits = 0;
524
525	// split viewcell polygons with respect to split plane
526	splits += SplitPolygons(interior->GetPlane(),
527	*tData.mPolygons,
528	*frontPolys,
529	*backPolys,
530	coincident);
531
532	// extract view cells associated with the split polygons
533	ViewCell *frontViewCell = GetOrCreateOutOfBoundsCell();
534	ViewCell *backViewCell = GetOrCreateOutOfBoundsCell();
535
536	BspTraversalData frontData(interior->GetFront(),
537	frontPolys,
538	tData.mDepth + 1,
539	mOutOfBoundsCell,
540	tData.mRays,
541	tData.mPvs,
542	mUseAreaForPvs ? mBox.SurfaceArea() : mBox.GetVolume(),
543	new BspNodeGeometry());
544
545	BspTraversalData backData(interior->GetBack(),
546	backPolys,
547	tData.mDepth + 1,
548	mOutOfBoundsCell,
549	tData.mRays,
550	tData.mPvs,
551	mUseAreaForPvs ? mBox.SurfaceArea() : mBox.GetVolume(),
552	new BspNodeGeometry());
553
554	if (!mGenerateViewCells)
555	{
556	ExtractViewCells(frontData,
557	backData,
558	coincident,
559	interior->mPlane);
560	}
561
562	// don't need coincident polygons anymore
563	CLEAR_CONTAINER(coincident);
564
565	mStat.polySplits += splits;
566
567	// push the children on the stack
568	tStack.push(frontData);
569	tStack.push(backData);
570	}
571
572	// cleanup
573	DEL_PTR(tData.mPolygons);
574	DEL_PTR(tData.mRays);
575	}
576	else
577	{
578	// reached leaf => subdivide current viewcell
579	BspNode *subRoot = Subdivide(tStack, tData);
580	}
581	}
582	}
583
584	int BspTree::AddMeshToPolygons(Mesh *mesh,
585	PolygonContainer &polys,
586	MeshInstance *parent)
587	{
588	FaceContainer::const_iterator fi;
589
590	// copy the face data to polygons
591	for (fi = mesh->mFaces.begin(); fi != mesh->mFaces.end(); ++ fi)
592	{
593	Polygon3 poly = new Polygon3((fi), mesh);
594
595	if (poly->Valid(mEpsilon))
596	{
597	poly->mParent = parent; // set parent intersectable
598	polys.push_back(poly);
599	}
600	else
601	DEL_PTR(poly);
602	}
603	return (int)mesh->mFaces.size();
604	}
605
606
607	int BspTree::AddToPolygonSoup(const ViewCellContainer &viewCells,
608	PolygonContainer &polys,
609	int maxObjects)
610	{
611	int limit = (maxObjects > 0) ?
612	Min((int)viewCells.size(), maxObjects) : (int)viewCells.size();
613
614	int polysSize = 0;
615
616	for (int i = 0; i < limit; ++ i)
617	{
618	if (viewCells[i]->GetMesh()) // copy the mesh data to polygons
619	{
620	mBox.Include(viewCells[i]->GetBox()); // add to BSP tree aabb
621	polysSize += AddMeshToPolygons(viewCells[i]->GetMesh(), polys, viewCells[i]);
622	}
623	}
624
625	return polysSize;
626	}
627
628
629	int BspTree::AddToPolygonSoup(const ObjectContainer &objects,
630	PolygonContainer &polys,
631	int maxObjects,
632	bool addToBbox)
633	{
634	int limit = (maxObjects > 0) ?
635	Min((int)objects.size(), maxObjects) : (int)objects.size();
636
637	for (int i = 0; i < limit; ++i)
638	{
639	Intersectable object = objects[i];//it;
640	Mesh *mesh = NULL;
641
642	switch (object->Type()) // extract the meshes
643	{
644	case Intersectable::MESH_INSTANCE:
645	mesh = dynamic_cast<MeshInstance *>(object)->GetMesh();
646	break;
647	case Intersectable::VIEW_CELL:
648	mesh = dynamic_cast<ViewCell *>(object)->GetMesh();
649	break;
650	// TODO: handle transformed mesh instances
651	default:
652	Debug << "intersectable type not supported" << endl;
653	break;
654	}
655
656	if (mesh) // copy the mesh data to polygons
657	{
658	if (addToBbox)
659	{
660	mBox.Include(object->GetBox()); // add to BSP tree aabb
661	}
662
663	AddMeshToPolygons(mesh, polys, mOutOfBoundsCell);
664	}
665	}
666
667	return (int)polys.size();
668	}
669
670
671	void BspTree::Construct(const ViewCellContainer &viewCells)
672	{
673	mStat.nodes = 1;
674	mBox.Initialize(); // initialise bsp tree bounding box
675
676	// copy view cell meshes into one big polygon soup
677	PolygonContainer *polys = new PolygonContainer();
678	mStat.polys = AddToPolygonSoup(viewCells, *polys);
679
680	// view cells are given
681	mGenerateViewCells = false;
682	// construct tree from the view cell polygons
683	Construct(polys, new BoundedRayContainer());
684	}
685
686
687	void BspTree::Construct(const ObjectContainer &objects)
688	{
689	mStat.nodes = 1;
690	mBox.Initialize(); // initialise bsp tree bounding box
691
692	PolygonContainer *polys = new PolygonContainer();
693
694	mGenerateViewCells = true;
695	// copy mesh instance polygons into one big polygon soup
696	mStat.polys = AddToPolygonSoup(objects, *polys);
697
698	// construct tree from polygon soup
699	Construct(polys, new BoundedRayContainer());
700	}
701
702
703	void BspTree::Construct(const RayContainer &sampleRays,
704	AxisAlignedBox3 *forcedBoundingBox)
705	{
706	mStat.nodes = 1;
707	mBox.Initialize(); // initialise BSP tree bounding box
708
709	if (forcedBoundingBox)
710	mBox = *forcedBoundingBox;
711
712	PolygonContainer *polys = new PolygonContainer();
713	BoundedRayContainer *rays = new BoundedRayContainer();
714
715	RayContainer::const_iterator rit, rit_end = sampleRays.end();
716
717	// generate view cells
718	mGenerateViewCells = true;
719
720	long startTime = GetTime();
721
722	Debug << "** Extracting polygons from rays **\n";
723
724	std::map<Face , Polygon3 > facePolyMap;
725
726	//-- extract polygons intersected by the rays
727	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
728	{
729	Ray ray = rit;
730
731	// get ray-face intersection. Store polygon representing the rays together
732	// with rays intersecting the face.
733	if (!ray->intersections.empty())
734	{
735	MeshInstance obj = dynamic_cast<MeshInstance >(ray->intersections[0].mObject);
736	Face *face = obj->GetMesh()->mFaces[ray->intersections[0].mFace];
737
738	std::map<Face , Polygon3 >::iterator it = facePolyMap.find(face);
739
740	if (it != facePolyMap.end())
741	{
742	//store rays if needed for heuristics
743	if (mSplitPlaneStrategy & BLOCKED_RAYS)
744	(*it).second->mPiercingRays.push_back(ray);
745	}
746	else
747	{ //store rays if needed for heuristics
748	Polygon3 *poly = new Polygon3(face, obj->GetMesh());
749	poly->mParent = obj;
750	polys->push_back(poly);
751
752	if (mSplitPlaneStrategy & BLOCKED_RAYS)
753	poly->mPiercingRays.push_back(ray);
754
755	facePolyMap[face] = poly;
756	}
757	}
758	}
759
760	facePolyMap.clear();
761
762	// compute bounding box
763	if (!forcedBoundingBox)
764	Polygon3::IncludeInBox(*polys, mBox);
765
766	//-- store rays
767	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
768	{
769	Ray ray = rit;
770	ray->SetId(-1); // reset id
771
772	float minT, maxT;
773	if (mBox.GetRaySegment(*ray, minT, maxT))
774	rays->push_back(new BoundedRay(ray, minT, maxT));
775	}
776
777	mStat.polys = (int)polys->size();
778
779	Debug << "** Finished polygon extraction **" << endl;
780	Debug << (int)polys->size() << " polys extracted from " << (int)sampleRays.size() << " rays" << endl;
781	Debug << "extraction time: " << TimeDiff(startTime, GetTime())*1e-3 << "s" << endl;
782
783	Construct(polys, rays);
784	}
785
786
787	void BspTree::Construct(const ObjectContainer &objects,
788	const RayContainer &sampleRays,
789	AxisAlignedBox3 *forcedBoundingBox)
790	{
791	mStat.nodes = 1;
792	mBox.Initialize(); // initialise BSP tree bounding box
793
794	if (forcedBoundingBox)
795	mBox = *forcedBoundingBox;
796
797	BoundedRayContainer *rays = new BoundedRayContainer();
798	PolygonContainer *polys = new PolygonContainer();
799
800	mGenerateViewCells = true;
801
802	// copy mesh instance polygons into one big polygon soup
803	mStat.polys = AddToPolygonSoup(objects, *polys, 0, !forcedBoundingBox);
804
805
806	RayContainer::const_iterator rit, rit_end = sampleRays.end();
807
808	//-- store rays
809	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
810	{
811	Ray ray = rit;
812	ray->SetId(-1); // reset id
813
814	float minT, maxT;
815	if (mBox.GetRaySegment(*ray, minT, maxT))
816	rays->push_back(new BoundedRay(ray, minT, maxT));
817	}
818
819	Debug << "tree has " << (int)polys->size() << " polys, " << (int)sampleRays.size() << " rays" << endl;
820	Construct(polys, rays);
821	}
822
823
824	void BspTree::Construct(PolygonContainer polys, BoundedRayContainer rays)
825	{
826	BspTraversalStack tStack;
827
828	mRoot = new BspLeaf();
829
830	// constrruct root node geometry
831	BspNodeGeometry *geom = new BspNodeGeometry();
832	ConstructGeometry(mRoot, *geom);
833
834	BspTraversalData tData(mRoot,
835	polys,
836	0,
837	GetOrCreateOutOfBoundsCell(),
838	rays,
839	ComputePvsSize(*rays),
840	mUseAreaForPvs ? geom->GetArea() : geom->GetVolume(),
841	geom);
842
843	tStack.push(tData);
844
845	mStat.Start();
846	cout << "Contructing bsp tree ... ";
847	long startTime = GetTime();
848	while (!tStack.empty())
849	{
850	tData = tStack.top();
851
852	tStack.pop();
853
854	// subdivide leaf node
855	BspNode *r = Subdivide(tStack, tData);
856
857	if (r == mRoot)
858	Debug << "BSP tree construction time spent at root: "
859	<< TimeDiff(startTime, GetTime())*1e-3 << " secs" << endl;
860	}
861
862	cout << "finished\n";
863
864	mStat.Stop();
865	}
866
867
868	bool BspTree::TerminationCriteriaMet(const BspTraversalData &data) const
869	{
870	return
871	(((int)data.mPolygons->size() <= mTermMinPolys) \|\|
872	((int)data.mRays->size() <= mTermMinRays) \|\|
873	(data.mPvs <= mTermMinPvs) \|\|
874	(data.mProbability <= mTermMinProbability) \|\|
875	(data.mDepth >= mTermMaxDepth) \|\|
876	(mStat.Leaves() >= mMaxViewCells) \|\|
877	(data.GetAvgRayContribution() > mTermMaxRayContribution));
878	}
879
880
881	BspNode *BspTree::Subdivide(BspTraversalStack &tStack, BspTraversalData &tData)
882	{
883	//-- terminate traversal
884	if (TerminationCriteriaMet(tData))
885	{
886	BspLeaf leaf = dynamic_cast<BspLeaf >(tData.mNode);
887
888	BspViewCell *viewCell;
889
890	// generate new view cell for each leaf
891	if (mGenerateViewCells)
892	viewCell = new BspViewCell();
893	else
894	// add view cell to leaf
895	viewCell = dynamic_cast<BspViewCell *>(tData.mViewCell);
896
897	leaf->SetViewCell(viewCell);
898	viewCell->mLeaf = leaf;
899
900	if (mUseAreaForPvs)
901	viewCell->SetArea(tData.mProbability);
902	else
903	viewCell->SetVolume(tData.mProbability);
904
905	//-- add pvs
906	if (viewCell != mOutOfBoundsCell)
907	{
908	int conSamp = 0, sampCon = 0;
909	AddToPvs(leaf, *tData.mRays, conSamp, sampCon);
910
911	mStat.contributingSamples += conSamp;
912	mStat.sampleContributions += sampCon;
913	}
914
915	EvaluateLeafStats(tData);
916
917	//-- clean up
918
919	// discard polygons
920	CLEAR_CONTAINER(*tData.mPolygons);
921	// discard rays
922	CLEAR_CONTAINER(*tData.mRays);
923
924	DEL_PTR(tData.mPolygons);
925	DEL_PTR(tData.mRays);
926	DEL_PTR(tData.mGeometry);
927
928	return leaf;
929	}
930
931	//-- continue subdivision
932	PolygonContainer coincident;
933
934	BspTraversalData tFrontData(NULL, new PolygonContainer(), tData.mDepth + 1, mOutOfBoundsCell,
935	new BoundedRayContainer(), 0, 0, new BspNodeGeometry());
936	BspTraversalData tBackData(NULL, new PolygonContainer(), tData.mDepth + 1, mOutOfBoundsCell,
937	new BoundedRayContainer(), 0, 0, new BspNodeGeometry());
938
939	// create new interior node and two leaf nodes
940	BspInterior *interior =
941	SubdivideNode(tData, tFrontData, tBackData, coincident);
942
943
944	// extract view cells from coincident polygons according to plane normal
945	// only if front or back polygons are empty
946	if (!mGenerateViewCells)
947	{
948	ExtractViewCells(tFrontData,
949	tBackData,
950	coincident,
951	interior->mPlane);
952	}
953
954	// don't need coincident polygons anymory
955	CLEAR_CONTAINER(coincident);
956
957	// push the children on the stack
958	tStack.push(tFrontData);
959	tStack.push(tBackData);
960
961	// cleanup
962	DEL_PTR(tData.mNode);
963
964	DEL_PTR(tData.mPolygons);
965	DEL_PTR(tData.mRays);
966	DEL_PTR(tData.mGeometry);
967
968	return interior;
969	}
970
971	void BspTree::ExtractViewCells(BspTraversalData &frontData,
972	BspTraversalData &backData,
973	const PolygonContainer &coincident,
974	const Plane3 &splitPlane) const
975	{
976	// if not empty, tree is further subdivided => don't have to find view cell
977	bool foundFront = !frontData.mPolygons->empty();
978	bool foundBack = !frontData.mPolygons->empty();
979
980	PolygonContainer::const_iterator it =
981	coincident.begin(), it_end = coincident.end();
982
983	//-- find first view cells in front and back leafs
984	for (; !(foundFront && foundBack) && (it != it_end); ++ it)
985	{
986	if (DotProd((*it)->GetNormal(), splitPlane.mNormal) > 0)
987	{
988	backData.mViewCell = dynamic_cast<ViewCell >((it)->mParent);
989	foundBack = true;
990	}
991	else
992	{
993	frontData.mViewCell = dynamic_cast<ViewCell >((it)->mParent);
994	foundFront = true;
995	}
996	}
997	}
998
999	BspInterior *BspTree::SubdivideNode(BspTraversalData &tData,
1000	BspTraversalData &frontData,
1001	BspTraversalData &backData,
1002	PolygonContainer &coincident)
1003	{
1004	mStat.nodes += 2;
1005
1006	BspLeaf leaf = dynamic_cast<BspLeaf >(tData.mNode);
1007
1008	long startTime;
1009	if (0)
1010	{
1011	Debug << "*********************" << endl;
1012	startTime = GetTime();
1013	}
1014
1015	// select subdivision plane
1016	BspInterior *interior =
1017	new BspInterior(SelectPlane(leaf, tData));
1018
1019	if (0)
1020	{
1021	Debug << "time used for split plane selection: "
1022	<< TimeDiff(startTime, GetTime()) * 1e-3 << "s" << endl;
1023	}
1024	#ifdef _DEBUG
1025	Debug << interior << endl;
1026	#endif
1027
1028
1029	if (0)
1030	{
1031	Debug << "number of rays: " << (int)tData.mRays->size() << endl;
1032	Debug << "number of polys: " << (int)tData.mPolygons->size() << endl;
1033
1034	startTime = GetTime();
1035	}
1036
1037	// subdivide rays into front and back rays
1038	SplitRays(interior->mPlane, tData.mRays, frontData.mRays, *backData.mRays);
1039
1040	if (0)
1041	{
1042	Debug << "time used for rays splitting: " << TimeDiff(startTime, GetTime())*1e-3 << "s" << endl;
1043	startTime = GetTime();
1044	}
1045
1046	// subdivide polygons with plane
1047	mStat.polySplits += SplitPolygons(interior->GetPlane(),
1048	*tData.mPolygons,
1049	*frontData.mPolygons,
1050	*backData.mPolygons,
1051	coincident);
1052
1053	if (0)
1054	{
1055	Debug << "time used for polygon splitting: " << TimeDiff(startTime, GetTime())*1e-3 << "s" << endl;
1056	}
1057
1058	// compute pvs
1059	frontData.mPvs = ComputePvsSize(*frontData.mRays);
1060	backData.mPvs = ComputePvsSize(*backData.mRays);
1061
1062	// split geometry and compute area
1063	if (1)
1064	{
1065	tData.mGeometry->SplitGeometry(*frontData.mGeometry,
1066	*backData.mGeometry,
1067	interior->mPlane,
1068	mBox,
1069	mEpsilon);
1070
1071
1072	frontData.mProbability = frontData.mGeometry->GetVolume();
1073	backData.mProbability = backData.mGeometry->GetVolume();
1074	}
1075
1076	// compute accumulated ray length
1077	//frontData.mAccRayLength = AccumulatedRayLength(*frontData.mRays);
1078	//backData.mAccRayLength = AccumulatedRayLength(*backData.mRays);
1079
1080	//-- create front and back leaf
1081
1082	BspInterior *parent = leaf->GetParent();
1083
1084	// replace a link from node's parent
1085	if (!leaf->IsRoot())
1086	{
1087	parent->ReplaceChildLink(leaf, interior);
1088	interior->SetParent(parent);
1089	}
1090	else // new root
1091	{
1092	mRoot = interior;
1093	}
1094
1095	// and setup child links
1096	interior->SetupChildLinks(new BspLeaf(interior), new BspLeaf(interior));
1097
1098	frontData.mNode = interior->GetFront();
1099	backData.mNode = interior->GetBack();
1100
1101	frontData.mNode->mTimeStamp = mTimeStamp;
1102	backData.mNode->mTimeStamp = mTimeStamp ++;
1103
1104	//DEL_PTR(leaf);
1105	return interior;
1106	}
1107
1108
1109	void BspTree::SortSplitCandidates(const PolygonContainer &polys,
1110	const int axis,
1111	vector<SortableEntry> &splitCandidates) const
1112	{
1113	splitCandidates.clear();
1114
1115	int requestedSize = 2 * (int)polys.size();
1116	// creates a sorted split candidates array
1117	splitCandidates.reserve(requestedSize);
1118
1119	PolygonContainer::const_iterator it, it_end = polys.end();
1120
1121	AxisAlignedBox3 box;
1122
1123	// insert all queries
1124	for(it = polys.begin(); it != it_end; ++ it)
1125	{
1126	box.Initialize();
1127	box.Include((it));
1128
1129	splitCandidates.push_back(SortableEntry(SortableEntry::POLY_MIN, box.Min(axis), *it));
1130	splitCandidates.push_back(SortableEntry(SortableEntry::POLY_MAX, box.Max(axis), *it));
1131	}
1132
1133	stable_sort(splitCandidates.begin(), splitCandidates.end());
1134	}
1135
1136
1137	float BspTree::BestCostRatio(const PolygonContainer &polys,
1138	const AxisAlignedBox3 &box,
1139	const int axis,
1140	float &position,
1141	int &objectsBack,
1142	int &objectsFront) const
1143	{
1144	vector<SortableEntry> splitCandidates;
1145
1146	SortSplitCandidates(polys, axis, splitCandidates);
1147
1148	// go through the lists, count the number of objects left and right
1149	// and evaluate the following cost funcion:
1150	// C = ct_div_ci + (ol + or)/queries
1151
1152	int objectsLeft = 0, objectsRight = (int)polys.size();
1153
1154	float minBox = box.Min(axis);
1155	float maxBox = box.Max(axis);
1156	float boxArea = box.SurfaceArea();
1157
1158	float minBand = minBox + mSplitBorder * (maxBox - minBox);
1159	float maxBand = minBox + (1.0f - mSplitBorder) * (maxBox - minBox);
1160
1161	float minSum = 1e20f;
1162	vector<SortableEntry>::const_iterator ci, ci_end = splitCandidates.end();
1163
1164	for(ci = splitCandidates.begin(); ci != ci_end; ++ ci)
1165	{
1166	switch ((*ci).type)
1167	{
1168	case SortableEntry::POLY_MIN:
1169	++ objectsLeft;
1170	break;
1171	case SortableEntry::POLY_MAX:
1172	-- objectsRight;
1173	break;
1174	default:
1175	break;
1176	}
1177
1178	if ((ci).value > minBand && (ci).value < maxBand)
1179	{
1180	AxisAlignedBox3 lbox = box;
1181	AxisAlignedBox3 rbox = box;
1182	lbox.SetMax(axis, (*ci).value);
1183	rbox.SetMin(axis, (*ci).value);
1184
1185	const float sum = objectsLeft * lbox.SurfaceArea() +
1186	objectsRight * rbox.SurfaceArea();
1187
1188	if (sum < minSum)
1189	{
1190	minSum = sum;
1191	position = (*ci).value;
1192
1193	objectsBack = objectsLeft;
1194	objectsFront = objectsRight;
1195	}
1196	}
1197	}
1198
1199	const float oldCost = (float)polys.size();
1200	const float newCost = mAxisAlignedCtDivCi + minSum / boxArea;
1201	const float ratio = newCost / oldCost;
1202
1203
1204	#if 0
1205	Debug << "====================" << endl;
1206	Debug << "costRatio=" << ratio << " pos=" << position<<" t=" << (position - minBox)/(maxBox - minBox)
1207	<< "\t o=(" << objectsBack << "," << objectsFront << ")" << endl;
1208	#endif
1209	return ratio;
1210	}
1211
1212	bool BspTree::SelectAxisAlignedPlane(Plane3 &plane,
1213	const PolygonContainer &polys) const
1214	{
1215	AxisAlignedBox3 box;
1216	box.Initialize();
1217
1218	// create bounding box of region
1219	Polygon3::IncludeInBox(polys, box);
1220
1221	int objectsBack = 0, objectsFront = 0;
1222	int axis = 0;
1223	float costRatio = MAX_FLOAT;
1224	Vector3 position;
1225
1226	//-- area subdivision
1227	for (int i = 0; i < 3; ++ i)
1228	{
1229	float p = 0;
1230	float r = BestCostRatio(polys, box, i, p, objectsBack, objectsFront);
1231
1232	if (r < costRatio)
1233	{
1234	costRatio = r;
1235	axis = i;
1236	position = p;
1237	}
1238	}
1239
1240	if (costRatio >= mMaxCostRatio)
1241	return false;
1242
1243	Vector3 norm(0,0,0); norm[axis] = 1.0f;
1244	plane = Plane3(norm, position);
1245
1246	return true;
1247	}
1248
1249
1250	Plane3 BspTree::SelectPlane(BspLeaf *leaf, BspTraversalData &data)
1251	{
1252	if (data.mPolygons->empty() && data.mRays->empty())
1253	{
1254	Debug << "Warning: No autopartition polygon candidate available\n";
1255
1256	// return axis aligned split
1257	AxisAlignedBox3 box;
1258	box.Initialize();
1259
1260	// create bounding box of region
1261	Polygon3::IncludeInBox(*data.mPolygons, box);
1262
1263	const int axis = box.Size().DrivingAxis();
1264	const Vector3 position = (box.Min()[axis] + box.Max()[axis]) * 0.5f;
1265
1266	Vector3 norm(0,0,0); norm[axis] = 1.0f;
1267	return Plane3(norm, position);
1268	}
1269
1270	if ((mSplitPlaneStrategy & AXIS_ALIGNED) &&
1271	((int)data.mPolygons->size() > mTermMinPolysForAxisAligned) &&
1272	((int)data.mRays->size() > mTermMinRaysForAxisAligned) &&
1273	((mTermMinObjectsForAxisAligned < 0) \|\|
1274	(Polygon3::ParentObjectsSize(*data.mPolygons) > mTermMinObjectsForAxisAligned)))
1275	{
1276	Plane3 plane;
1277	if (SelectAxisAlignedPlane(plane, *data.mPolygons))
1278	return plane;
1279	}
1280
1281	// simplest strategy: just take next polygon
1282	if (mSplitPlaneStrategy & RANDOM_POLYGON)
1283	{
1284	if (!data.mPolygons->empty())
1285	{
1286	Polygon3 *nextPoly =
1287	(*data.mPolygons)[(int)RandomValue(0, (Real)((int)data.mPolygons->size() - 1))];
1288	return nextPoly->GetSupportingPlane();
1289	}
1290	else
1291	{
1292	const int candidateIdx = (int)RandomValue(0, (Real)((int)data.mRays->size() - 1));
1293	BoundedRay bRay = (data.mRays)[candidateIdx];
1294
1295	Ray *ray = bRay->mRay;
1296
1297	const Vector3 minPt = ray->Extrap(bRay->mMinT);
1298	const Vector3 maxPt = ray->Extrap(bRay->mMaxT);
1299
1300	const Vector3 pt = (maxPt + minPt) * 0.5;
1301
1302	const Vector3 normal = ray->GetDir();
1303
1304	return Plane3(normal, pt);
1305	}
1306
1307	return Plane3();
1308	}
1309
1310	// use heuristics to find appropriate plane
1311	return SelectPlaneHeuristics(leaf, data);
1312	}
1313
1314
1315	Plane3 BspTree::ChooseCandidatePlane(const BoundedRayContainer &rays) const
1316	{
1317	const int candidateIdx = (int)RandomValue(0, (Real)((int)rays.size() - 1));
1318	BoundedRay *bRay = rays[candidateIdx];
1319	Ray *ray = bRay->mRay;
1320
1321	const Vector3 minPt = ray->Extrap(bRay->mMinT);
1322	const Vector3 maxPt = ray->Extrap(bRay->mMaxT);
1323
1324	const Vector3 pt = (maxPt + minPt) * 0.5;
1325
1326	const Vector3 normal = ray->GetDir();
1327
1328	return Plane3(normal, pt);
1329	}
1330
1331	Plane3 BspTree::ChooseCandidatePlane2(const BoundedRayContainer &rays) const
1332	{
1333	Vector3 pt[3];
1334	int idx[3];
1335	int cmaxT = 0;
1336	int cminT = 0;
1337	bool chooseMin = false;
1338
1339	for (int j = 0; j < 3; j ++)
1340	{
1341	idx[j] = (int)RandomValue(0, Real((int)rays.size() * 2 - 1));
1342
1343	if (idx[j] >= (int)rays.size())
1344	{
1345	idx[j] -= (int)rays.size();
1346	chooseMin = (cminT < 2);
1347	}
1348	else
1349	chooseMin = (cmaxT < 2);
1350
1351	BoundedRay *bRay = rays[idx[j]];
1352	pt[j] = chooseMin ? bRay->mRay->Extrap(bRay->mMinT) :
1353	bRay->mRay->Extrap(bRay->mMaxT);
1354	}
1355
1356	return Plane3(pt[0], pt[1], pt[2]);
1357	}
1358
1359	Plane3 BspTree::ChooseCandidatePlane3(const BoundedRayContainer &rays) const
1360	{
1361	Vector3 pt[3];
1362
1363	int idx1 = (int)RandomValue(0, (Real)((int)rays.size() - 1));
1364	int idx2 = (int)RandomValue(0, (Real)((int)rays.size() - 1));
1365
1366	// check if rays different
1367	if (idx1 == idx2)
1368	idx2 = (idx2 + 1) % (int)rays.size();
1369
1370	const BoundedRay *ray1 = rays[idx1];
1371	const BoundedRay *ray2 = rays[idx2];
1372
1373	// normal vector of the plane parallel to both lines
1374	const Vector3 norm =
1375	Normalize(CrossProd(ray1->mRay->GetDir(), ray2->mRay->GetDir()));
1376
1377	const Vector3 orig1 = ray1->mRay->Extrap(ray1->mMinT);
1378	const Vector3 orig2 = ray2->mRay->Extrap(ray2->mMinT);
1379
1380	// vector from line 1 to line 2
1381	const Vector3 vd = orig1 - orig2;
1382
1383	// project vector on normal to get distance
1384	const float dist = DotProd(vd, norm);
1385
1386	// point on plane lies halfway between the two planes
1387	const Vector3 planePt = orig1 + norm * dist * 0.5;
1388
1389	return Plane3(norm, planePt);
1390	}
1391
1392
1393	Plane3 BspTree::SelectPlaneHeuristics(BspLeaf *leaf, BspTraversalData &data)
1394	{
1395	float lowestCost = MAX_FLOAT;
1396	Plane3 bestPlane;
1397	// intermediate plane
1398	Plane3 plane;
1399
1400	const int limit = Min((int)data.mPolygons->size(), mMaxPolyCandidates);
1401	int maxIdx = (int)data.mPolygons->size();
1402
1403	for (int i = 0; i < limit; ++ i)
1404	{
1405	// assure that no index is taken twice
1406	const int candidateIdx = (int)RandomValue(0, (Real)(-- maxIdx));
1407
1408	Polygon3 poly = (data.mPolygons)[candidateIdx];
1409
1410	// swap candidate to the end to avoid testing same plane
1411	std::swap((data.mPolygons)[maxIdx], (data.mPolygons)[candidateIdx]);
1412	//Polygon3 poly = (data.mPolygons)[(int)RandomValue(0, (int)polys.size() - 1)];
1413
1414	// evaluate current candidate
1415	const float candidateCost =
1416	SplitPlaneCost(poly->GetSupportingPlane(), data);
1417
1418	if (candidateCost < lowestCost)
1419	{
1420	bestPlane = poly->GetSupportingPlane();
1421	lowestCost = candidateCost;
1422	}
1423	}
1424
1425	//-- choose candidate planes extracted from rays
1426	for (int i = 0; i < mMaxRayCandidates; ++ i)
1427	{
1428	plane = ChooseCandidatePlane3(*data.mRays);
1429	const float candidateCost = SplitPlaneCost(plane, data);
1430
1431	if (candidateCost < lowestCost)
1432	{
1433	bestPlane = plane;
1434	lowestCost = candidateCost;
1435	}
1436	}
1437
1438	#ifdef _DEBUG
1439	Debug << "plane lowest cost: " << lowestCost << endl;
1440	#endif
1441
1442	return bestPlane;
1443	}
1444
1445
1446	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1447	const PolygonContainer &polys) const
1448	{
1449	float val = 0;
1450
1451	float sumBalancedPolys = 0;
1452	float sumSplits = 0;
1453	float sumPolyArea = 0;
1454	float sumBalancedViewCells = 0;
1455	float sumBlockedRays = 0;
1456	float totalBlockedRays = 0;
1457	//float totalArea = 0;
1458	int totalViewCells = 0;
1459
1460	// need three unique ids for each type of view cell
1461	// for balanced view cells criterium
1462	ViewCell::NewMail();
1463	const int backId = ViewCell::sMailId;
1464	ViewCell::NewMail();
1465	const int frontId = ViewCell::sMailId;
1466	ViewCell::NewMail();
1467	const int frontAndBackId = ViewCell::sMailId;
1468
1469	bool useRand;;
1470	int limit;
1471
1472	// choose test polyongs randomly if over threshold
1473	if ((int)polys.size() > mMaxTests)
1474	{
1475	useRand = true;
1476	limit = mMaxTests;
1477	}
1478	else
1479	{
1480	useRand = false;
1481	limit = (int)polys.size();
1482	}
1483
1484	for (int i = 0; i < limit; ++ i)
1485	{
1486	const int testIdx = useRand ? (int)RandomValue(0, (Real)(limit - 1)) : i;
1487
1488	Polygon3 *poly = polys[testIdx];
1489
1490	const int classification =
1491	poly->ClassifyPlane(candidatePlane, mEpsilon);
1492
1493	if (mSplitPlaneStrategy & BALANCED_POLYS)
1494	sumBalancedPolys += sBalancedPolysTable[classification];
1495
1496	if (mSplitPlaneStrategy & LEAST_SPLITS)
1497	sumSplits += sLeastPolySplitsTable[classification];
1498
1499	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
1500	{
1501	if (classification == Polygon3::COINCIDENT)
1502	sumPolyArea += poly->GetArea();
1503	//totalArea += area;
1504	}
1505
1506	if (mSplitPlaneStrategy & BLOCKED_RAYS)
1507	{
1508	const float blockedRays = (float)poly->mPiercingRays.size();
1509
1510	if (classification == Polygon3::COINCIDENT)
1511	sumBlockedRays += blockedRays;
1512
1513	totalBlockedRays += blockedRays;
1514	}
1515
1516	// assign view cells to back or front according to classificaion
1517	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
1518	{
1519	MeshInstance *viewCell = poly->mParent;
1520
1521	// assure that we only count a view cell
1522	// once for the front and once for the back side of the plane
1523	if (classification == Polygon3::FRONT_SIDE)
1524	{
1525	if ((viewCell->mMailbox != frontId) &&
1526	(viewCell->mMailbox != frontAndBackId))
1527	{
1528	sumBalancedViewCells += 1.0;
1529
1530	if (viewCell->mMailbox != backId)
1531	viewCell->mMailbox = frontId;
1532	else
1533	viewCell->mMailbox = frontAndBackId;
1534
1535	++ totalViewCells;
1536	}
1537	}
1538	else if (classification == Polygon3::BACK_SIDE)
1539	{
1540	if ((viewCell->mMailbox != backId) &&
1541	(viewCell->mMailbox != frontAndBackId))
1542	{
1543	sumBalancedViewCells -= 1.0;
1544
1545	if (viewCell->mMailbox != frontId)
1546	viewCell->mMailbox = backId;
1547	else
1548	viewCell->mMailbox = frontAndBackId;
1549
1550	++ totalViewCells;
1551	}
1552	}
1553	}
1554	}
1555
1556	const float polysSize = (float)polys.size() + Limits::Small;
1557
1558	// all values should be approx. between 0 and 1 so they can be combined
1559	// and scaled with the factors according to their importance
1560	if (mSplitPlaneStrategy & BALANCED_POLYS)
1561	val += mBalancedPolysFactor * fabs(sumBalancedPolys) / polysSize;
1562
1563	if (mSplitPlaneStrategy & LEAST_SPLITS)
1564	val += mLeastSplitsFactor * sumSplits / polysSize;
1565
1566	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
1567	// HACK: polys.size should be total area so scaling is between 0 and 1
1568	val += mLargestPolyAreaFactor * (float)polys.size() / sumPolyArea;
1569
1570	if (mSplitPlaneStrategy & BLOCKED_RAYS)
1571	if (totalBlockedRays != 0)
1572	val += mBlockedRaysFactor * (totalBlockedRays - sumBlockedRays) / totalBlockedRays;
1573
1574	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
1575	val += mBalancedViewCellsFactor * fabs(sumBalancedViewCells) /
1576	((float)totalViewCells + Limits::Small);
1577
1578	return val;
1579	}
1580
1581
1582	inline void BspTree::GenerateUniqueIdsForPvs()
1583	{
1584	Intersectable::NewMail(); sBackId = ViewCell::sMailId;
1585	Intersectable::NewMail(); sFrontId = ViewCell::sMailId;
1586	Intersectable::NewMail(); sFrontAndBackId = ViewCell::sMailId;
1587	}
1588
1589
1590	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1591	const BoundedRayContainer &rays,
1592	const int pvs,
1593	const float probability,
1594	const BspNodeGeometry &cell) const
1595	{
1596	float val = 0;
1597
1598	float sumBalancedRays = 0;
1599	float sumRaySplits = 0;
1600
1601	int frontPvs = 0;
1602	int backPvs = 0;
1603
1604	// probability that view point lies in child
1605	float pOverall = 0;
1606	float pFront = 0;
1607	float pBack = 0;
1608
1609	const bool pvsUseLen = false;
1610
1611	if (mSplitPlaneStrategy & PVS)
1612	{
1613	// create unique ids for pvs heuristics
1614	GenerateUniqueIdsForPvs();
1615
1616	// construct child geometry with regard to the candidate split plane
1617	BspNodeGeometry frontCell;
1618	BspNodeGeometry backCell;
1619
1620	cell.SplitGeometry(frontCell,
1621	backCell,
1622	candidatePlane,
1623	mBox,
1624	mEpsilon);
1625
1626	if (mUseAreaForPvs)
1627	{
1628	pFront = frontCell.GetArea();
1629	pBack = backCell.GetArea();
1630	}
1631	else
1632	{
1633	pFront = frontCell.GetVolume();
1634	pBack = pOverall - pFront;
1635	}
1636
1637
1638	pOverall = probability;
1639	}
1640
1641	bool useRand;
1642	int limit;
1643
1644	// choose test polyongs randomly if over threshold
1645	if ((int)rays.size() > mMaxTests)
1646	{
1647	useRand = true;
1648	limit = mMaxTests;
1649	}
1650	else
1651	{
1652	useRand = false;
1653	limit = (int)rays.size();
1654	}
1655
1656	for (int i = 0; i < limit; ++ i)
1657	{
1658	const int testIdx = useRand ? (int)RandomValue(0, (Real)(limit - 1)) : i;
1659
1660	BoundedRay *bRay = rays[testIdx];
1661
1662	Ray *ray = bRay->mRay;
1663	const float minT = bRay->mMinT;
1664	const float maxT = bRay->mMaxT;
1665
1666	Vector3 entP, extP;
1667
1668	const int cf =
1669	ray->ClassifyPlane(candidatePlane, minT, maxT, entP, extP);
1670
1671	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
1672	{
1673	sumBalancedRays += sBalancedRaysTable[cf];
1674	}
1675
1676	if (mSplitPlaneStrategy & BALANCED_RAYS)
1677	{
1678	sumRaySplits += sLeastRaySplitsTable[cf];
1679	}
1680
1681	if (mSplitPlaneStrategy & PVS)
1682	{
1683	// in case the ray intersects an object
1684	// assure that we only count the object
1685	// once for the front and once for the back side of the plane
1686
1687	// add the termination object
1688	if (!ray->intersections.empty())
1689	AddObjToPvs(ray->intersections[0].mObject, cf, frontPvs, backPvs);
1690
1691	// add the source object
1692	AddObjToPvs(ray->sourceObject.mObject, cf, frontPvs, backPvs);
1693	}
1694	}
1695
1696	const float raysSize = (float)rays.size() + Limits::Small;
1697
1698	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
1699	val += mLeastRaySplitsFactor * sumRaySplits / raysSize;
1700
1701	if (mSplitPlaneStrategy & BALANCED_RAYS)
1702	val += mBalancedRaysFactor * fabs(sumBalancedRays) / raysSize;
1703
1704	const float denom = pOverall * (float)pvs * 2.0f + Limits::Small;
1705
1706	if (mSplitPlaneStrategy & PVS)
1707	{
1708	val += mPvsFactor * (frontPvs * pFront + (backPvs * pBack)) / denom;
1709
1710	// give penalty to unbalanced split
1711	if (0)
1712	if (((pFront * 0.2 + Limits::Small) > pBack) \|\|
1713	(pFront < (pBack * 0.2 + Limits::Small)))
1714	val += 0.5;
1715	}
1716
1717
1718	#ifdef _DEBUG
1719	Debug << "totalpvs: " << pvs << " ptotal: " << pOverall
1720	<< " frontpvs: " << frontPvs << " pFront: " << pFront
1721	<< " backpvs: " << backPvs << " pBack: " << pBack << endl << endl;
1722	#endif
1723
1724	return val;
1725	}
1726
1727	void BspTree::AddObjToPvs(Intersectable *obj,
1728	const int cf,
1729	int &frontPvs,
1730	int &backPvs) const
1731	{
1732	if (!obj)
1733	return;
1734	// TODO: does this really belong to no pvs?
1735	//if (cf == Ray::COINCIDENT) return;
1736
1737	// object belongs to both PVS
1738	const bool bothSides = (cf == Ray::FRONT_BACK) \|\|
1739	(cf == Ray::BACK_FRONT) \|\|
1740	(cf == Ray::COINCIDENT);
1741
1742	if ((cf == Ray::FRONT) \|\| bothSides)
1743	{
1744	if ((obj->mMailbox != sFrontId) &&
1745	(obj->mMailbox != sFrontAndBackId))
1746	{
1747	++ frontPvs;
1748
1749	if (obj->mMailbox == sBackId)
1750	obj->mMailbox = sFrontAndBackId;
1751	else
1752	obj->mMailbox = sFrontId;
1753	}
1754	}
1755
1756	if ((cf == Ray::BACK) \|\| bothSides)
1757	{
1758	if ((obj->mMailbox != sBackId) &&
1759	(obj->mMailbox != sFrontAndBackId))
1760	{
1761	++ backPvs;
1762
1763	if (obj->mMailbox == sFrontId)
1764	obj->mMailbox = sFrontAndBackId;
1765	else
1766	obj->mMailbox = sBackId;
1767	}
1768	}
1769	}
1770
1771	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1772	BspTraversalData &data) const
1773	{
1774	float val = 0;
1775
1776	if (mSplitPlaneStrategy & VERTICAL_AXIS)
1777	{
1778	Vector3 tinyAxis(0,0,0); tinyAxis[mBox.Size().TinyAxis()] = 1.0f;
1779	// we put a penalty on the dot product between the "tiny" vertical axis
1780	// and the split plane axis
1781	val += mVerticalSplitsFactor *
1782	fabs(DotProd(candidatePlane.mNormal, tinyAxis));
1783	}
1784
1785	// the following criteria loop over all polygons to find the cost value
1786	if ((mSplitPlaneStrategy & BALANCED_POLYS) \|\|
1787	(mSplitPlaneStrategy & LEAST_SPLITS) \|\|
1788	(mSplitPlaneStrategy & LARGEST_POLY_AREA) \|\|
1789	(mSplitPlaneStrategy & BALANCED_VIEW_CELLS) \|\|
1790	(mSplitPlaneStrategy & BLOCKED_RAYS))
1791	{
1792	val += SplitPlaneCost(candidatePlane, *data.mPolygons);
1793	}
1794
1795	// the following criteria loop over all rays to find the cost value
1796	if ((mSplitPlaneStrategy & BALANCED_RAYS) \|\|
1797	(mSplitPlaneStrategy & LEAST_RAY_SPLITS) \|\|
1798	(mSplitPlaneStrategy & PVS))
1799	{
1800	val += SplitPlaneCost(candidatePlane, *data.mRays, data.mPvs,
1801	data.mProbability, *data.mGeometry);
1802	}
1803
1804	// return linear combination of the sums
1805	return val;
1806	}
1807
1808	void BspTree::CollectLeaves(vector<BspLeaf *> &leaves) const
1809	{
1810	stack<BspNode *> nodeStack;
1811	nodeStack.push(mRoot);
1812
1813	while (!nodeStack.empty())
1814	{
1815	BspNode *node = nodeStack.top();
1816
1817	nodeStack.pop();
1818
1819	if (node->IsLeaf())
1820	{
1821	BspLeaf leaf = (BspLeaf )node;
1822	leaves.push_back(leaf);
1823	}
1824	else
1825	{
1826	BspInterior interior = dynamic_cast<BspInterior >(node);
1827
1828	nodeStack.push(interior->GetBack());
1829	nodeStack.push(interior->GetFront());
1830	}
1831	}
1832	}
1833
1834
1835	AxisAlignedBox3 BspTree::GetBoundingBox() const
1836	{
1837	return mBox;
1838	}
1839
1840
1841	void BspTree::EvaluateLeafStats(const BspTraversalData &data)
1842	{
1843	// the node became a leaf -> evaluate stats for leafs
1844	BspLeaf leaf = dynamic_cast<BspLeaf >(data.mNode);
1845
1846	// store maximal and minimal depth
1847	if (data.mDepth > mStat.maxDepth)
1848	mStat.maxDepth = data.mDepth;
1849
1850	if (data.mDepth < mStat.minDepth)
1851	mStat.minDepth = data.mDepth;
1852
1853	// accumulate depth to compute average depth
1854	mStat.accumDepth += data.mDepth;
1855	// accumulate rays to compute rays / leaf
1856	mStat.accumRays += (int)data.mRays->size();
1857
1858	if (data.mDepth >= mTermMaxDepth)
1859	++ mStat.maxDepthNodes;
1860
1861	if (data.mPvs < mTermMinPvs)
1862	++ mStat.minPvsNodes;
1863
1864	if ((int)data.mRays->size() < mTermMinRays)
1865	++ mStat.minRaysNodes;
1866
1867	if (data.GetAvgRayContribution() > mTermMaxRayContribution)
1868	++ mStat.maxRayContribNodes;
1869
1870	if (data.mProbability <= mTermMinProbability)
1871	++ mStat.minProbabilityNodes;
1872
1873	#ifdef _DEBUG
1874	Debug << "BSP stats: "
1875	<< "Depth: " << data.mDepth << " (max: " << mTermMaxDepth << "), "
1876	<< "PVS: " << data.mPvs << " (min: " << mTermMinPvs << "), "
1877	<< "Probability: " << data.mProbability << " (min: " << mTermMinProbability << "), "
1878	<< "#polygons: " << (int)data.mPolygons->size() << " (max: " << mTermMinPolys << "), "
1879	<< "#rays: " << (int)data.mRays->size() << " (max: " << mTermMinRays << "), "
1880	<< "#pvs: " << leaf->GetViewCell()->GetPvs().GetSize() << "=, "
1881	<< "#avg ray contrib (pvs): " << (float)data.mPvs / (float)data.mRays->size() << endl;
1882	#endif
1883	}
1884
1885	int
1886	BspTree::_CastRay(Ray &ray)
1887	{
1888	int hits = 0;
1889
1890	stack<BspRayTraversalData> tStack;
1891
1892	float maxt, mint;
1893
1894	if (!mBox.GetRaySegment(ray, mint, maxt))
1895	return 0;
1896
1897	Intersectable::NewMail();
1898
1899	Vector3 entp = ray.Extrap(mint);
1900	Vector3 extp = ray.Extrap(maxt);
1901
1902	BspNode *node = mRoot;
1903	BspNode *farChild = NULL;
1904
1905	while (1)
1906	{
1907	if (!node->IsLeaf())
1908	{
1909	BspInterior in = dynamic_cast<BspInterior >(node);
1910
1911	Plane3 splitPlane = in->GetPlane();
1912	const int entSide = splitPlane.Side(entp);
1913	const int extSide = splitPlane.Side(extp);
1914
1915	if (entSide < 0)
1916	{
1917	node = in->GetBack();
1918
1919	if(extSide <= 0) // plane does not split ray => no far child
1920	continue;
1921
1922	farChild = in->GetFront(); // plane splits ray
1923
1924	} else if (entSide > 0)
1925	{
1926	node = in->GetFront();
1927
1928	if (extSide >= 0) // plane does not split ray => no far child
1929	continue;
1930
1931	farChild = in->GetBack(); // plane splits ray
1932	}
1933	else // ray and plane are coincident
1934	{
1935	// WHAT TO DO IN THIS CASE ?
1936	//break;
1937	node = in->GetFront();
1938	continue;
1939	}
1940
1941	// push data for far child
1942	tStack.push(BspRayTraversalData(farChild, extp, maxt));
1943
1944	// find intersection of ray segment with plane
1945	float t;
1946	extp = splitPlane.FindIntersection(ray.GetLoc(), extp, &t);
1947	maxt *= t;
1948
1949	} else // reached leaf => intersection with view cell
1950	{
1951	BspLeaf leaf = dynamic_cast<BspLeaf >(node);
1952
1953	if (!leaf->mViewCell->Mailed())
1954	{
1955	// ray.bspIntersections.push_back(Ray::BspIntersection(maxt, leaf));
1956	leaf->mViewCell->Mail();
1957	++ hits;
1958	}
1959
1960	//-- fetch the next far child from the stack
1961	if (tStack.empty())
1962	break;
1963
1964	entp = extp;
1965	mint = maxt; // NOTE: need this?
1966
1967	if (ray.GetType() == Ray::LINE_SEGMENT && mint > 1.0f)
1968	break;
1969
1970	BspRayTraversalData &s = tStack.top();
1971
1972	node = s.mNode;
1973	extp = s.mExitPoint;
1974	maxt = s.mMaxT;
1975
1976	tStack.pop();
1977	}
1978	}
1979
1980	return hits;
1981	}
1982
1983
1984	int BspTree::CastLineSegment(const Vector3 &origin,
1985	const Vector3 &termination,
1986	vector<ViewCell *> &viewcells)
1987	{
1988	int hits = 0;
1989	stack<BspRayTraversalData> tStack;
1990
1991	float mint = 0.0f, maxt = 1.0f;
1992
1993	Intersectable::NewMail();
1994	ViewCell::NewMail();
1995
1996	Vector3 entp = origin;
1997	Vector3 extp = termination;
1998
1999	BspNode *node = mRoot;
2000	BspNode *farChild = NULL;
2001
2002	while (1)
2003	{
2004	if (!node->IsLeaf())
2005	{
2006	BspInterior in = dynamic_cast<BspInterior >(node);
2007
2008	Plane3 splitPlane = in->GetPlane();
2009
2010	const int entSide = splitPlane.Side(entp);
2011	const int extSide = splitPlane.Side(extp);
2012
2013	if (entSide < 0)
2014	{
2015	node = in->GetBack();
2016
2017	if(extSide <= 0) // plane does not split ray => no far child
2018	continue;
2019
2020	farChild = in->GetFront(); // plane splits ray
2021
2022	}
2023	else if (entSide > 0)
2024	{
2025	node = in->GetFront();
2026
2027	if (extSide >= 0) // plane does not split ray => no far child
2028	continue;
2029
2030	farChild = in->GetBack(); // plane splits ray
2031	}
2032	else // ray and plane are coincident
2033	{
2034	// WHAT TO DO IN THIS CASE ?
2035	//break;
2036	node = in->GetFront();
2037	continue;
2038	}
2039
2040	// push data for far child
2041	tStack.push(BspRayTraversalData(farChild, extp, maxt));
2042
2043	// find intersection of ray segment with plane
2044	float t;
2045	extp = splitPlane.FindIntersection(origin, extp, &t);
2046	maxt *= t;
2047	}
2048	else
2049	{
2050	// reached leaf => intersection with view cell
2051	BspLeaf leaf = dynamic_cast<BspLeaf >(node);
2052
2053	if (!leaf->mViewCell->Mailed())
2054	{
2055	viewcells.push_back(leaf->mViewCell);
2056	leaf->mViewCell->Mail();
2057	hits++;
2058	}
2059
2060	//-- fetch the next far child from the stack
2061	if (tStack.empty())
2062	break;
2063
2064	entp = extp;
2065	mint = maxt; // NOTE: need this?
2066
2067	BspRayTraversalData &s = tStack.top();
2068
2069	node = s.mNode;
2070	extp = s.mExitPoint;
2071	maxt = s.mMaxT;
2072
2073	tStack.pop();
2074	}
2075	}
2076	return hits;
2077	}
2078
2079
2080	void BspTree::CollectViewCells(ViewCellContainer &viewCells) const
2081	{
2082	stack<BspNode *> nodeStack;
2083	nodeStack.push(mRoot);
2084
2085	ViewCell::NewMail();
2086
2087	while (!nodeStack.empty())
2088	{
2089	BspNode *node = nodeStack.top();
2090	nodeStack.pop();
2091
2092	if (node->IsLeaf())
2093	{
2094	ViewCell viewCell = dynamic_cast<BspLeaf >(node)->mViewCell;
2095
2096	if (!viewCell->Mailed())
2097	{
2098	viewCell->Mail();
2099	viewCells.push_back(viewCell);
2100	}
2101	}
2102	else
2103	{
2104	BspInterior interior = dynamic_cast<BspInterior >(node);
2105
2106	nodeStack.push(interior->GetFront());
2107	nodeStack.push(interior->GetBack());
2108	}
2109	}
2110	}
2111
2112
2113	BspTreeStatistics &BspTree::GetStat()
2114	{
2115	return mStat;
2116	}
2117
2118
2119	float BspTree::AccumulatedRayLength(BoundedRayContainer &rays) const
2120	{
2121	float len = 0;
2122
2123	BoundedRayContainer::const_iterator it, it_end = rays.end();
2124
2125	for (it = rays.begin(); it != it_end; ++ it)
2126	{
2127	len += SqrDistance((it)->mRay->Extrap((it)->mMinT),
2128	(it)->mRay->Extrap((it)->mMaxT));
2129	}
2130
2131	return len;
2132	}
2133
2134
2135	int BspTree::SplitRays(const Plane3 &plane,
2136	BoundedRayContainer &rays,
2137	BoundedRayContainer &frontRays,
2138	BoundedRayContainer &backRays)
2139	{
2140	int splits = 0;
2141
2142	while (!rays.empty())
2143	{
2144	BoundedRay *bRay = rays.back();
2145	Ray *ray = bRay->mRay;
2146	float minT = bRay->mMinT;
2147	float maxT = bRay->mMaxT;
2148
2149	rays.pop_back();
2150
2151	Vector3 entP, extP;
2152
2153	const int cf =
2154	ray->ClassifyPlane(plane, minT, maxT, entP, extP);
2155
2156	// set id to ray classification
2157	ray->SetId(cf);
2158
2159	switch (cf)
2160	{
2161	case Ray::COINCIDENT: // TODO: should really discard ray?
2162	frontRays.push_back(bRay);
2163	//DEL_PTR(bRay);
2164	break;
2165	case Ray::BACK:
2166	backRays.push_back(bRay);
2167	break;
2168	case Ray::FRONT:
2169	frontRays.push_back(bRay);
2170	break;
2171	case Ray::FRONT_BACK:
2172	{
2173	// find intersection of ray segment with plane
2174	const float t = plane.FindT(ray->GetLoc(), extP);
2175
2176	const float newT = t * maxT;
2177
2178	frontRays.push_back(new BoundedRay(ray, minT, newT));
2179	backRays.push_back(new BoundedRay(ray, newT, maxT));
2180
2181	DEL_PTR(bRay);
2182	}
2183	break;
2184	case Ray::BACK_FRONT:
2185	{
2186	// find intersection of ray segment with plane
2187	const float t = plane.FindT(ray->GetLoc(), extP);
2188	const float newT = t * bRay->mMaxT;
2189
2190	backRays.push_back(new BoundedRay(ray, minT, newT));
2191	frontRays.push_back(new BoundedRay(ray, newT, maxT));
2192
2193	DEL_PTR(bRay);
2194
2195	++ splits;
2196	}
2197	break;
2198	default:
2199	Debug << "Should not come here 4" << endl;
2200	break;
2201	}
2202	}
2203
2204	return splits;
2205	}
2206
2207	void BspTree::ExtractHalfSpaces(BspNode *n, vector<Plane3> &halfSpaces) const
2208	{
2209	BspNode *lastNode;
2210	do
2211	{
2212	lastNode = n;
2213
2214	// want to get planes defining geometry of this node => don't take
2215	// split plane of node itself
2216	n = n->GetParent();
2217
2218	if (n)
2219	{
2220	BspInterior interior = dynamic_cast<BspInterior >(n);
2221	Plane3 halfSpace = dynamic_cast<BspInterior *>(interior)->GetPlane();
2222
2223	if (interior->GetFront() != lastNode)
2224	halfSpace.ReverseOrientation();
2225
2226	halfSpaces.push_back(halfSpace);
2227	}
2228	}
2229	while (n);
2230	}
2231
2232
2233
2234	void BspTree::ConstructGeometry(ViewCell *vc,
2235	BspNodeGeometry &vcGeom) const
2236	{
2237	ViewCellContainer leaves;
2238	mViewCellsTree->CollectLeaves(vc, leaves);
2239
2240	ViewCellContainer::const_iterator it, it_end = leaves.end();
2241
2242	for (it = leaves.begin(); it != it_end; ++ it)
2243	{
2244	BspLeaf l = dynamic_cast<BspViewCell >(*it)->mLeaf;
2245	ConstructGeometry(l, vcGeom);
2246	}
2247	}
2248
2249
2250	void BspTree::SetViewCellsManager(ViewCellsManager *vcm)
2251	{
2252	mViewCellsManager = vcm;
2253	}
2254
2255
2256	void BspTree::ConstructGeometry(BspNode *n, BspNodeGeometry &geom) const
2257	{
2258	vector<Plane3> halfSpaces;
2259	ExtractHalfSpaces(n, halfSpaces);
2260
2261	PolygonContainer candidates;
2262
2263	// bounded planes are added to the polygons (reverse polygons
2264	// as they have to be outfacing
2265	for (int i = 0; i < (int)halfSpaces.size(); ++ i)
2266	{
2267	Polygon3 *p = GetBoundingBox().CrossSection(halfSpaces[i]);
2268
2269	if (p->Valid(mEpsilon))
2270	{
2271	candidates.push_back(p->CreateReversePolygon());
2272	DEL_PTR(p);
2273	}
2274	}
2275
2276	// add faces of bounding box (also could be faces of the cell)
2277	for (int i = 0; i < 6; ++ i)
2278	{
2279	VertexContainer vertices;
2280
2281	for (int j = 0; j < 4; ++ j)
2282	vertices.push_back(mBox.GetFace(i).mVertices[j]);
2283
2284	candidates.push_back(new Polygon3(vertices));
2285	}
2286
2287	for (int i = 0; i < (int)candidates.size(); ++ i)
2288	{
2289	// polygon is split by all other planes
2290	for (int j = 0; (j < (int)halfSpaces.size()) && candidates[i]; ++ j)
2291	{
2292	if (i == j) // polygon and plane are coincident
2293	continue;
2294
2295	VertexContainer splitPts;
2296	Polygon3 frontPoly, backPoly;
2297
2298	const int cf = candidates[i]->
2299	ClassifyPlane(halfSpaces[j], mEpsilon);
2300
2301	switch (cf)
2302	{
2303	case Polygon3::SPLIT:
2304	frontPoly = new Polygon3();
2305	backPoly = new Polygon3();
2306
2307	candidates[i]->Split(halfSpaces[j],
2308	*frontPoly,
2309	*backPoly,
2310	mEpsilon);
2311
2312	DEL_PTR(candidates[i]);
2313
2314	if (frontPoly->Valid(mEpsilon))
2315	candidates[i] = frontPoly;
2316	else
2317	DEL_PTR(frontPoly);
2318
2319	DEL_PTR(backPoly);
2320	break;
2321	case Polygon3::BACK_SIDE:
2322	DEL_PTR(candidates[i]);
2323	break;
2324	// just take polygon as it is
2325	case Polygon3::FRONT_SIDE:
2326	case Polygon3::COINCIDENT:
2327	default:
2328	break;
2329	}
2330	}
2331
2332	if (candidates[i])
2333	geom.mPolys.push_back(candidates[i]);
2334	}
2335	}
2336
2337
2338	typedef pair<BspNode , BspNodeGeometry > bspNodePair;
2339
2340
2341	int BspTree::FindNeighbors(BspNode n, vector<BspLeaf > &neighbors,
2342	const bool onlyUnmailed) const
2343	{
2344	stack<bspNodePair> nodeStack;
2345
2346	BspNodeGeometry nodeGeom;
2347	ConstructGeometry(n, nodeGeom);
2348
2349	// split planes from the root to this node
2350	// needed to verify that we found neighbor leaf
2351	// TODO: really needed?
2352	vector<Plane3> halfSpaces;
2353	ExtractHalfSpaces(n, halfSpaces);
2354
2355
2356	BspNodeGeometry *rgeom = new BspNodeGeometry();
2357	ConstructGeometry(mRoot, *rgeom);
2358
2359	nodeStack.push(bspNodePair(mRoot, rgeom));
2360
2361	while (!nodeStack.empty())
2362	{
2363	BspNode *node = nodeStack.top().first;
2364	BspNodeGeometry *geom = nodeStack.top().second;
2365
2366	nodeStack.pop();
2367
2368	if (node->IsLeaf())
2369	{
2370	// test if this leaf is in valid view space
2371	if (node->TreeValid() &&
2372	(node != n) &&
2373	(!onlyUnmailed \|\| !node->Mailed()))
2374	{
2375	bool isAdjacent = true;
2376
2377	if (1)
2378	{
2379	// test all planes of current node if still adjacent
2380	for (int i = 0; (i < halfSpaces.size()) && isAdjacent; ++ i)
2381	{
2382	const int cf =
2383	Polygon3::ClassifyPlane(geom->mPolys,
2384	halfSpaces[i],
2385	mEpsilon);
2386
2387	if (cf == Polygon3::BACK_SIDE)
2388	{
2389	isAdjacent = false;
2390	}
2391	}
2392	}
2393	else
2394	{
2395	// TODO: why is this wrong??
2396	// test all planes of current node if still adjacent
2397	for (int i = 0; (i < (int)nodeGeom.mPolys.size()) && isAdjacent; ++ i)
2398	{
2399	Polygon3 *poly = nodeGeom.mPolys[i];
2400
2401	const int cf =
2402	Polygon3::ClassifyPlane(geom->mPolys,
2403	poly->GetSupportingPlane(),
2404	mEpsilon);
2405
2406	if (cf == Polygon3::BACK_SIDE)
2407	{
2408	isAdjacent = false;
2409	}
2410	}
2411	}
2412	// neighbor was found
2413	if (isAdjacent)
2414	{
2415	neighbors.push_back(dynamic_cast<BspLeaf *>(node));
2416	}
2417	}
2418	}
2419	else
2420	{
2421	BspInterior interior = dynamic_cast<BspInterior >(node);
2422
2423	const int cf = Polygon3::ClassifyPlane(nodeGeom.mPolys,
2424	interior->GetPlane(),
2425	mEpsilon);
2426
2427	BspNode *front = interior->GetFront();
2428	BspNode *back = interior->GetBack();
2429
2430	BspNodeGeometry *fGeom = new BspNodeGeometry();
2431	BspNodeGeometry *bGeom = new BspNodeGeometry();
2432
2433	geom->SplitGeometry(*fGeom,
2434	*bGeom,
2435	interior->GetPlane(),
2436	mBox,
2437	mEpsilon);
2438
2439	if (cf == Polygon3::FRONT_SIDE)
2440	{
2441	nodeStack.push(bspNodePair(interior->GetFront(), fGeom));
2442	DEL_PTR(bGeom);
2443	}
2444	else
2445	{
2446	if (cf == Polygon3::BACK_SIDE)
2447	{
2448	nodeStack.push(bspNodePair(interior->GetBack(), bGeom));
2449	DEL_PTR(fGeom);
2450	}
2451	else
2452	{ // random decision
2453	nodeStack.push(bspNodePair(front, fGeom));
2454	nodeStack.push(bspNodePair(back, bGeom));
2455	}
2456	}
2457	}
2458
2459	DEL_PTR(geom);
2460	}
2461
2462	return (int)neighbors.size();
2463	}
2464
2465
2466	BspLeaf *BspTree::GetRandomLeaf(const Plane3 &halfspace)
2467	{
2468	stack<BspNode *> nodeStack;
2469	nodeStack.push(mRoot);
2470
2471	int mask = rand();
2472
2473	while (!nodeStack.empty())
2474	{
2475	BspNode *node = nodeStack.top();
2476	nodeStack.pop();
2477
2478	if (node->IsLeaf())
2479	{
2480	return dynamic_cast<BspLeaf *>(node);
2481	}
2482	else
2483	{
2484	BspInterior interior = dynamic_cast<BspInterior >(node);
2485	BspNode *next;
2486
2487	BspNodeGeometry geom;
2488	// todo: not very efficient: constructs full cell everytime
2489	ConstructGeometry(interior, geom);
2490
2491	const int cf = Polygon3::ClassifyPlane(geom.mPolys,
2492	halfspace,
2493	mEpsilon);
2494
2495	if (cf == Polygon3::BACK_SIDE)
2496	next = interior->GetFront();
2497	else
2498	if (cf == Polygon3::FRONT_SIDE)
2499	next = interior->GetFront();
2500	else
2501	{
2502	// random decision
2503	if (mask & 1)
2504	next = interior->GetBack();
2505	else
2506	next = interior->GetFront();
2507	mask = mask >> 1;
2508	}
2509
2510	nodeStack.push(next);
2511	}
2512	}
2513
2514	return NULL;
2515	}
2516
2517
2518	BspLeaf *BspTree::GetRandomLeaf(const bool onlyUnmailed)
2519	{
2520	stack<BspNode *> nodeStack;
2521
2522	nodeStack.push(mRoot);
2523
2524	int mask = rand();
2525
2526	while (!nodeStack.empty())
2527	{
2528	BspNode *node = nodeStack.top();
2529	nodeStack.pop();
2530
2531	if (node->IsLeaf())
2532	{
2533	if ( (!onlyUnmailed \|\| !node->Mailed()) )
2534	return dynamic_cast<BspLeaf *>(node);
2535	}
2536	else
2537	{
2538	BspInterior interior = dynamic_cast<BspInterior >(node);
2539
2540	// random decision
2541	if (mask & 1)
2542	nodeStack.push(interior->GetBack());
2543	else
2544	nodeStack.push(interior->GetFront());
2545
2546	mask = mask >> 1;
2547	}
2548	}
2549
2550	return NULL;
2551	}
2552
2553
2554	void BspTree::AddToPvs(BspLeaf *leaf,
2555	const BoundedRayContainer &rays,
2556	int &sampleContributions,
2557	int &contributingSamples)
2558	{
2559	sampleContributions = 0;
2560	contributingSamples = 0;
2561
2562	BoundedRayContainer::const_iterator it, it_end = rays.end();
2563
2564	ViewCell *vc = leaf->GetViewCell();
2565
2566	// add contributions from samples to the PVS
2567	for (it = rays.begin(); it != it_end; ++ it)
2568	{
2569	int contribution = 0;
2570	Ray ray = (it)->mRay;
2571	float relContribution;
2572	if (!ray->intersections.empty())
2573	contribution += vc->GetPvs().AddSample(ray->intersections[0].mObject,
2574	1.0f,
2575	relContribution);
2576
2577	if (ray->sourceObject.mObject)
2578	contribution += vc->GetPvs().AddSample(ray->sourceObject.mObject,
2579	1.0f,
2580	relContribution);
2581
2582	if (contribution)
2583	{
2584	sampleContributions += contribution;
2585	++ contributingSamples;
2586	}
2587
2588	//if (ray->mFlags & Ray::STORE_BSP_INTERSECTIONS)
2589	// ray->bspIntersections.push_back(Ray::BspIntersection((*it)->mMinT, this));
2590	}
2591	}
2592
2593
2594	int BspTree::ComputePvsSize(const BoundedRayContainer &rays) const
2595	{
2596	int pvsSize = 0;
2597
2598	BoundedRayContainer::const_iterator rit, rit_end = rays.end();
2599
2600	Intersectable::NewMail();
2601
2602	for (rit = rays.begin(); rit != rays.end(); ++ rit)
2603	{
2604	Ray ray = (rit)->mRay;
2605
2606	if (!ray->intersections.empty())
2607	{
2608	if (!ray->intersections[0].mObject->Mailed())
2609	{
2610	ray->intersections[0].mObject->Mail();
2611	++ pvsSize;
2612	}
2613	}
2614	if (ray->sourceObject.mObject)
2615	{
2616	if (!ray->sourceObject.mObject->Mailed())
2617	{
2618	ray->sourceObject.mObject->Mail();
2619	++ pvsSize;
2620	}
2621	}
2622	}
2623
2624	return pvsSize;
2625	}
2626
2627
2628	float BspTree::GetEpsilon() const
2629	{
2630	return mEpsilon;
2631	}
2632
2633
2634	int BspTree::CollectMergeCandidates(const vector<BspLeaf *> leaves,
2635	vector<MergeCandidate> &candidates)
2636	{
2637	BspLeaf::NewMail();
2638
2639	vector<BspLeaf *>::const_iterator it, it_end = leaves.end();
2640
2641	int numCandidates = 0;
2642
2643	// find merge candidates and push them into queue
2644	for (it = leaves.begin(); it != it_end; ++ it)
2645	{
2646	BspLeaf leaf = it;
2647
2648	// the same leaves must not be part of two merge candidates
2649	leaf->Mail();
2650	vector<BspLeaf *> neighbors;
2651	FindNeighbors(leaf, neighbors, true);
2652
2653	vector<BspLeaf *>::const_iterator nit, nit_end = neighbors.end();
2654
2655	// TODO: test if at least one ray goes from one leaf to the other
2656	for (nit = neighbors.begin(); nit != nit_end; ++ nit)
2657	{
2658	if ((*nit)->GetViewCell() != leaf->GetViewCell())
2659	{
2660	MergeCandidate mc(leaf->GetViewCell(), (*nit)->GetViewCell());
2661	candidates.push_back(mc);
2662
2663	++ numCandidates;
2664	if ((numCandidates % 1000) == 0)
2665	{
2666	cout << "collected " << numCandidates << " merge candidates" << endl;
2667	}
2668	}
2669	}
2670	}
2671
2672	Debug << "merge queue: " << (int)candidates.size() << endl;
2673	Debug << "leaves in queue: " << numCandidates << endl;
2674
2675
2676	return (int)leaves.size();
2677	}
2678
2679
2680	int BspTree::CollectMergeCandidates(const VssRayContainer &rays,
2681	vector<MergeCandidate> &candidates)
2682	{
2683	ViewCell::NewMail();
2684	long startTime = GetTime();
2685
2686	map<BspLeaf , vector<BspLeaf> > neighborMap;
2687	ViewCellContainer::const_iterator iit;
2688
2689	int numLeaves = 0;
2690
2691	BspLeaf::NewMail();
2692
2693	for (int i = 0; i < (int)rays.size(); ++ i)
2694	{
2695	VssRay *ray = rays[i];
2696
2697	// traverse leaves stored in the rays and compare and
2698	// merge consecutive leaves (i.e., the neighbors in the tree)
2699	if (ray->mViewCells.size() < 2)
2700	continue;
2701
2702	iit = ray->mViewCells.begin();
2703	BspViewCell bspVc = dynamic_cast<BspViewCell >(*(iit ++));
2704	BspLeaf *leaf = bspVc->mLeaf;
2705
2706	// traverse intersections
2707	// consecutive leaves are neighbors => add them to queue
2708	for (; iit != ray->mViewCells.end(); ++ iit)
2709	{
2710	// next pair
2711	BspLeaf *prevLeaf = leaf;
2712	bspVc = dynamic_cast<BspViewCell >(iit);
2713	leaf = bspVc->mLeaf;
2714
2715	// view space not valid or same view cell
2716	if (!leaf->TreeValid() \|\| !prevLeaf->TreeValid() \|\|
2717	(leaf->GetViewCell() == prevLeaf->GetViewCell()))
2718	continue;
2719
2720	vector<BspLeaf *> &neighbors = neighborMap[leaf];
2721
2722	bool found = false;
2723
2724	// both leaves inserted in queue already =>
2725	// look if double pair already exists
2726	if (leaf->Mailed() && prevLeaf->Mailed())
2727	{
2728	vector<BspLeaf *>::const_iterator it, it_end = neighbors.end();
2729
2730	for (it = neighbors.begin(); !found && (it != it_end); ++ it)
2731	if (*it == prevLeaf)
2732	found = true; // already in queue
2733	}
2734
2735	if (!found)
2736	{
2737	// this pair is not in map yet
2738	// => insert into the neighbor map and the queue
2739	neighbors.push_back(prevLeaf);
2740	neighborMap[prevLeaf].push_back(leaf);
2741
2742	leaf->Mail();
2743	prevLeaf->Mail();
2744
2745	MergeCandidate mc(leaf->GetViewCell(), prevLeaf->GetViewCell());
2746
2747	candidates.push_back(mc);
2748
2749	if (((int)candidates.size() % 1000) == 0)
2750	{
2751	cout << "collected " << (int)candidates.size() << " merge candidates" << endl;
2752	}
2753	}
2754	}
2755	}
2756
2757	Debug << "neighbormap size: " << (int)neighborMap.size() << endl;
2758	Debug << "merge queue: " << (int)candidates.size() << endl;
2759	Debug << "leaves in queue: " << numLeaves << endl;
2760
2761
2762	//-- collect the leaves which haven't been found by ray casting
2763	#if 0
2764	cout << "finding additional merge candidates using geometry" << endl;
2765	vector<BspLeaf *> leaves;
2766	CollectLeaves(leaves, true);
2767	Debug << "found " << (int)leaves.size() << " new leaves" << endl << endl;
2768	CollectMergeCandidates(leaves, candidates);
2769	#endif
2770
2771	return numLeaves;
2772	}
2773
2774
2775
2776
2777	/***************************************************************/
2778	/* BspNodeGeometry Implementation */
2779	/***************************************************************/
2780
2781
2782	BspNodeGeometry::BspNodeGeometry(const BspNodeGeometry &rhs)
2783	{
2784	mPolys.reserve(rhs.mPolys.size());
2785
2786	PolygonContainer::const_iterator it, it_end = rhs.mPolys.end();
2787	for (it = rhs.mPolys.begin(); it != it_end; ++ it)
2788	{
2789	Polygon3 poly = it;
2790	mPolys.push_back(new Polygon3(*poly));
2791	}
2792	}
2793
2794
2795	BspNodeGeometry::~BspNodeGeometry()
2796	{
2797	CLEAR_CONTAINER(mPolys);
2798	}
2799
2800
2801	float BspNodeGeometry::GetArea() const
2802	{
2803	return Polygon3::GetArea(mPolys);
2804	}
2805
2806
2807	float BspNodeGeometry::GetVolume() const
2808	{
2809	//-- compute volume using tetrahedralization of the geometry
2810	// and adding the volume of the single tetrahedrons
2811	float volume = 0;
2812	const float f = 1.0f / 6.0f;
2813
2814	PolygonContainer::const_iterator pit, pit_end = mPolys.end();
2815
2816	// note: can take arbitrary point, e.g., the origin. However,
2817	// we rather take the center of mass to prevents precision errors
2818	const Vector3 center = CenterOfMass();
2819
2820	for (pit = mPolys.begin(); pit != pit_end; ++ pit)
2821	{
2822	Polygon3 poly = pit;
2823	const Vector3 v0 = poly->mVertices[0] - center;
2824
2825	for (int i = 1; i < (int)poly->mVertices.size() - 1; ++ i)
2826	{
2827	const Vector3 v1 = poly->mVertices[i] - center;
2828	const Vector3 v2 = poly->mVertices[i + 1] - center;
2829
2830	volume += f * (DotProd(v0, CrossProd(v1, v2)));
2831	}
2832	}
2833
2834	return volume;
2835	}
2836
2837
2838	Vector3 BspNodeGeometry::CenterOfMass() const
2839	{
2840	int n = 0;
2841
2842	Vector3 center(0,0,0);
2843
2844	PolygonContainer::const_iterator pit, pit_end = mPolys.end();
2845
2846	for (pit = mPolys.begin(); pit != pit_end; ++ pit)
2847	{
2848	Polygon3 poly = pit;
2849
2850	VertexContainer::const_iterator vit, vit_end = poly->mVertices.end();
2851
2852	for(vit = poly->mVertices.begin(); vit != vit_end; ++ vit)
2853	{
2854	center += *vit;
2855	++ n;
2856	}
2857	}
2858
2859	return center / (float)n;
2860	}
2861
2862
2863	void BspNodeGeometry::AddToMesh(Mesh &mesh)
2864	{
2865	PolygonContainer::const_iterator it, it_end = mPolys.end();
2866
2867	for (it = mPolys.begin(); it != mPolys.end(); ++ it)
2868	{
2869	(*it)->AddToMesh(mesh);
2870	}
2871	}
2872
2873
2874	void BspNodeGeometry::SplitGeometry(BspNodeGeometry &front,
2875	BspNodeGeometry &back,
2876	const Plane3 &splitPlane,
2877	const AxisAlignedBox3 &box,
2878	const float epsilon) const
2879	{
2880	// get cross section of new polygon
2881	Polygon3 *planePoly = box.CrossSection(splitPlane);
2882
2883	// split polygon with all other polygons
2884	planePoly = SplitPolygon(planePoly, epsilon);
2885
2886	//-- new polygon splits all other polygons
2887	for (int i = 0; i < (int)mPolys.size(); ++ i)
2888	{
2889	/// don't use epsilon here to get exact split planes
2890	const int cf =
2891	mPolys[i]->ClassifyPlane(splitPlane, Limits::Small);
2892
2893	switch (cf)
2894	{
2895	case Polygon3::SPLIT:
2896	{
2897	Polygon3 *poly = new Polygon3(mPolys[i]->mVertices);
2898
2899	Polygon3 *frontPoly = new Polygon3();
2900	Polygon3 *backPoly = new Polygon3();
2901
2902	poly->Split(splitPlane,
2903	*frontPoly,
2904	*backPoly,
2905	epsilon);
2906
2907	DEL_PTR(poly);
2908
2909	if (frontPoly->Valid(epsilon))
2910	front.mPolys.push_back(frontPoly);
2911	else
2912	DEL_PTR(frontPoly);
2913
2914	if (backPoly->Valid(epsilon))
2915	back.mPolys.push_back(backPoly);
2916	else
2917	DEL_PTR(backPoly);
2918	}
2919
2920	break;
2921	case Polygon3::BACK_SIDE:
2922	back.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
2923	break;
2924	case Polygon3::FRONT_SIDE:
2925	front.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
2926	break;
2927	case Polygon3::COINCIDENT:
2928	//front.mPolys.push_back(CreateReversePolygon(mPolys[i]));
2929	back.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
2930	break;
2931	default:
2932	break;
2933	}
2934	}
2935
2936	//-- finally add the new polygon to the child node geometries
2937	if (planePoly)
2938	{
2939	// add polygon with normal pointing into positive half space to back cell
2940	back.mPolys.push_back(planePoly);
2941	// add polygon with reverse orientation to front cell
2942	front.mPolys.push_back(planePoly->CreateReversePolygon());
2943	}
2944	}
2945
2946
2947	Polygon3 BspNodeGeometry::SplitPolygon(Polygon3 planePoly,
2948	const float epsilon) const
2949	{
2950	if (!planePoly->Valid(epsilon))
2951	DEL_PTR(planePoly);
2952
2953	// polygon is split by all other planes
2954	for (int i = 0; (i < (int)mPolys.size()) && planePoly; ++ i)
2955	{
2956	Plane3 plane = mPolys[i]->GetSupportingPlane();
2957
2958	/// don't use epsilon here to get exact split planes
2959	const int cf =
2960	planePoly->ClassifyPlane(plane, Limits::Small);
2961
2962	// split new polygon with all previous planes
2963	switch (cf)
2964	{
2965	case Polygon3::SPLIT:
2966	{
2967	Polygon3 *frontPoly = new Polygon3();
2968	Polygon3 *backPoly = new Polygon3();
2969
2970	planePoly->Split(plane,
2971	*frontPoly,
2972	*backPoly,
2973	epsilon);
2974
2975	// don't need anymore
2976	DEL_PTR(planePoly);
2977	DEL_PTR(frontPoly);
2978
2979	// back polygon is belonging to geometry
2980	if (backPoly->Valid(epsilon))
2981	planePoly = backPoly;
2982	else
2983	DEL_PTR(backPoly);
2984	}
2985	break;
2986	case Polygon3::FRONT_SIDE:
2987	DEL_PTR(planePoly);
2988	break;
2989	// polygon is taken as it is
2990	case Polygon3::BACK_SIDE:
2991	case Polygon3::COINCIDENT:
2992	default:
2993	break;
2994	}
2995	}
2996
2997	return planePoly;
2998	}
2999
3000
3001	ViewCell *
3002	BspTree::GetViewCell(const Vector3 &point)
3003	{
3004	if (mRoot == NULL)
3005	return NULL;
3006
3007
3008	stack<BspNode *> nodeStack;
3009	nodeStack.push(mRoot);
3010
3011	ViewCell *viewcell = NULL;
3012
3013	while (!nodeStack.empty()) {
3014	BspNode *node = nodeStack.top();
3015	nodeStack.pop();
3016
3017	if (node->IsLeaf()) {
3018	viewcell = dynamic_cast<BspLeaf *>(node)->mViewCell;
3019	break;
3020	} else {
3021
3022	BspInterior interior = dynamic_cast<BspInterior >(node);
3023
3024	// random decision
3025	if (interior->GetPlane().Side(point) < 0)
3026	nodeStack.push(interior->GetBack());
3027	else
3028	nodeStack.push(interior->GetFront());
3029	}
3030	}
3031
3032	return viewcell;
3033	}
3034
3035
3036	void BspNodeGeometry::IncludeInBox(AxisAlignedBox3 &box)
3037	{
3038	Polygon3::IncludeInBox(mPolys, box);
3039	}
3040
3041
3042	bool BspTree::Export(ofstream &stream)
3043	{
3044	ExportNode(mRoot, stream);
3045
3046	return true;
3047	}
3048
3049
3050	void BspTree::ExportNode(BspNode *node, ofstream &stream)
3051	{
3052	if (node->IsLeaf())
3053	{
3054	BspLeaf leaf = dynamic_cast<BspLeaf >(node);
3055
3056	int id = -1;
3057	if (leaf->GetViewCell() != mOutOfBoundsCell)
3058	id = leaf->GetViewCell()->GetId();
3059
3060	stream << "<Leaf viewCellId=\"" << id << "\" />" << endl;
3061	}
3062	else
3063	{
3064	BspInterior interior = dynamic_cast<BspInterior >(node);
3065
3066	Plane3 plane = interior->GetPlane();
3067	stream << "<Interior plane=\"" << plane.mNormal.x << " "
3068	<< plane.mNormal.y << " " << plane.mNormal.z << " "
3069	<< plane.mD << "\">" << endl;
3070
3071	ExportNode(interior->GetBack(), stream);
3072	ExportNode(interior->GetFront(), stream);
3073
3074	stream << "</Interior>" << endl;
3075	}
3076	}

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