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source: GTP/trunk/Lib/Vis/Preprocessing/src/ViewCellBsp.cpp @ 649

Revision 649, 77.2 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	mSubdivisionStats.open("subdivisionStats.log");
266
267	Debug << "BSP max depth: " << mTermMaxDepth << endl;
268	Debug << "BSP min PVS: " << mTermMinPvs << endl;
269	Debug << "BSP min probability: " << mTermMinProbability << endl;
270	Debug << "BSP max polys: " << mTermMinPolys << endl;
271	Debug << "BSP max rays: " << mTermMinRays << endl;
272	Debug << "BSP max polygon candidates: " << mMaxPolyCandidates << endl;
273	Debug << "BSP max plane candidates: " << mMaxRayCandidates << endl;
274
275	Debug << "Split plane strategy: ";
276	if (mSplitPlaneStrategy & RANDOM_POLYGON)
277	Debug << "random polygon ";
278	if (mSplitPlaneStrategy & AXIS_ALIGNED)
279	Debug << "axis aligned ";
280	if (mSplitPlaneStrategy & LEAST_SPLITS)
281	Debug << "least splits ";
282	if (mSplitPlaneStrategy & BALANCED_POLYS)
283	Debug << "balanced polygons ";
284	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
285	Debug << "balanced view cells ";
286	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
287	Debug << "largest polygon area ";
288	if (mSplitPlaneStrategy & VERTICAL_AXIS)
289	Debug << "vertical axis ";
290	if (mSplitPlaneStrategy & BLOCKED_RAYS)
291	Debug << "blocked rays ";
292	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
293	Debug << "least ray splits ";
294	if (mSplitPlaneStrategy & BALANCED_RAYS)
295	Debug << "balanced rays ";
296	if (mSplitPlaneStrategy & PVS)
297	Debug << "pvs";
298
299	Debug << endl;
300	}
301
302
303	const BspTreeStatistics &BspTree::GetStatistics() const
304	{
305	return mStat;
306	}
307
308
309	int BspTree::SplitPolygons(const Plane3 &plane,
310	PolygonContainer &polys,
311	PolygonContainer &frontPolys,
312	PolygonContainer &backPolys,
313	PolygonContainer &coincident) const
314	{
315	int splits = 0;
316
317	#ifdef _Debug
318	Debug << "splitting polygons of node " << this << " with plane " << mPlane << endl;
319	#endif
320
321	PolygonContainer::const_iterator it, it_end = polys.end();
322
323	for (it = polys.begin(); it != polys.end(); ++ it)
324	{
325	Polygon3 poly = it;
326
327	//-- classify polygon
328	const int cf = poly->ClassifyPlane(plane, mEpsilon);
329
330	switch (cf)
331	{
332	case Polygon3::COINCIDENT:
333	coincident.push_back(poly);
334	break;
335	case Polygon3::FRONT_SIDE:
336	frontPolys.push_back(poly);
337	break;
338	case Polygon3::BACK_SIDE:
339	backPolys.push_back(poly);
340	break;
341	case Polygon3::SPLIT:
342	{
343	Polygon3 *front_piece = new Polygon3(poly->mParent);
344	Polygon3 *back_piece = new Polygon3(poly->mParent);
345
346	//-- split polygon into front and back part
347	poly->Split(plane,
348	*front_piece,
349	*back_piece,
350	mEpsilon);
351
352	++ splits; // increase number of splits
353
354	//-- inherit rays from parent polygon for blocked ray criterium
355	poly->InheritRays(front_piece, back_piece);
356
357	// check if polygons still valid
358	if (front_piece->Valid(mEpsilon))
359	frontPolys.push_back(front_piece);
360	else
361	DEL_PTR(front_piece);
362
363	if (back_piece->Valid(mEpsilon))
364	backPolys.push_back(back_piece);
365	else
366	DEL_PTR(back_piece);
367
368	#ifdef _DEBUG
369	Debug << "split " << poly << endl << front_piece << endl << *back_piece << endl;
370	#endif
371	DEL_PTR(poly);
372	}
373	break;
374	default:
375	Debug << "SHOULD NEVER COME HERE\n";
376	break;
377	}
378	}
379
380	return splits;
381	}
382
383
384	void BspTreeStatistics::Print(ostream &app) const
385	{
386	app << "===== BspTree statistics ===============\n";
387
388	app << setprecision(4);
389
390	app << "#N_CTIME ( Construction time [s] )\n" << Time() << " \n";
391
392	app << "#N_NODES ( Number of nodes )\n" << nodes << "\n";
393
394	app << "#N_INTERIORS ( Number of interior nodes )\n" << Interior() << "\n";
395
396	app << "#N_LEAVES ( Number of leaves )\n" << Leaves() << "\n";
397
398	app << "#N_POLYSPLITS ( Number of polygon splits )\n" << polySplits << "\n";
399
400	app << "#AXIS_ALIGNED_SPLITS (number of axis aligned splits)\n" << splits[0] + splits[1] + splits[2] << endl;
401
402	app << "#N_SPLITS ( Number of splits in axes x y z\n";
403
404	for (int i = 0; i < 3; ++ i)
405	app << splits[i] << " ";
406	app << endl;
407
408	app << "#N_PMAXDEPTHLEAVES ( Percentage of leaves at maximum depth )\n"
409	<< maxDepthNodes * 100 / (double)Leaves() << endl;
410
411	app << "#N_PMINPVSLEAVES ( Percentage of leaves with mininimal PVS )\n"
412	<< minPvsNodes * 100 / (double)Leaves() << endl;
413
414	app << "#N_PMINRAYSLEAVES ( Percentage of leaves with minimal number of rays)\n"
415	<< minRaysNodes * 100 / (double)Leaves() << endl;
416
417	app << "#N_MAXCOSTNODES ( Percentage of leaves with terminated because of max cost ratio )\n"
418	<< maxCostNodes * 100 / (double)Leaves() << endl;
419
420	app << "#N_PMINPROBABILITYLEAVES ( Percentage of leaves with mininum probability )\n"
421	<< minProbabilityNodes * 100 / (double)Leaves() << endl;
422
423	app << "#N_PMAXRAYCONTRIBLEAVES ( Percentage of leaves with maximal ray contribution )\n"
424	<< maxRayContribNodes * 100 / (double)Leaves() << endl;
425
426	app << "#N_PMAXDEPTH ( Maximal reached depth )\n" << maxDepth << endl;
427
428	app << "#N_PMINDEPTH ( Minimal reached depth )\n" << minDepth << endl;
429
430	app << "#AVGDEPTH ( average depth )\n" << AvgDepth() << endl;
431
432	app << "#N_INPUTPOLYGONS (number of input polygons )\n" << polys << endl;
433
434	app << "#N_INVALIDLEAVES (number of invalid leaves )\n" << invalidLeaves << endl;
435
436	app << "#N_RAYS (number of rays / leaf)\n" << AvgRays() << endl;
437	//app << "#N_PVS: " << pvs << endl;
438
439	app << "#N_ROUTPUT_INPUT_POLYGONS ( ratio polygons after subdivision / input polygons )\n" <<
440	(polys + polySplits) / (double)polys << endl;
441
442	app << "===== END OF BspTree statistics ==========\n";
443	}
444
445
446	BspTree::~BspTree()
447	{
448	DEL_PTR(mRoot);
449
450	// TODO must be deleted if used!!
451	//if (mGenerateViewCells) DEL_PTR(mOutOfBoundsCell);
452	}
453
454	BspViewCell *BspTree::GetOutOfBoundsCell()
455	{
456	return mOutOfBoundsCell;
457	}
458
459
460	BspNode *BspTree::GetRoot() const
461	{
462	return mRoot;
463	}
464
465	BspViewCell *BspTree::GetOrCreateOutOfBoundsCell()
466	{
467	if (!mOutOfBoundsCell)
468	{
469	mOutOfBoundsCell = new BspViewCell();
470	mOutOfBoundsCell->SetId(-1);
471	mOutOfBoundsCell->SetValid(false);
472	}
473
474	return mOutOfBoundsCell;
475	}
476
477
478	void BspTree::InsertViewCell(ViewCell *viewCell)
479	{
480	PolygonContainer *polys = new PolygonContainer();
481
482	// don't generate new view cell, insert this one
483	mGenerateViewCells = false;
484	// extract polygons that guide the split process
485	mStat.polys += AddMeshToPolygons(viewCell->GetMesh(), *polys, viewCell);
486	mBox.Include(viewCell->GetBox()); // add to BSP aabb
487
488	InsertPolygons(polys);
489	}
490
491
492	void BspTree::InsertPolygons(PolygonContainer *polys)
493	{
494	BspTraversalStack tStack;
495
496	// traverse existing tree or create new tree
497	if (!mRoot)
498	mRoot = new BspLeaf();
499
500	tStack.push(BspTraversalData(mRoot,
501	polys,
502	0,
503	mOutOfBoundsCell,
504	new BoundedRayContainer(),
505	0,
506	mUseAreaForPvs ? mBox.SurfaceArea() : mBox.GetVolume(),
507	new BspNodeGeometry()));
508
509	while (!tStack.empty())
510	{
511	// filter polygons donw the tree
512	BspTraversalData tData = tStack.top();
513	tStack.pop();
514
515	if (!tData.mNode->IsLeaf())
516	{
517	BspInterior interior = dynamic_cast<BspInterior >(tData.mNode);
518
519	//-- filter view cell polygons down the tree until a leaf is reached
520	if (!tData.mPolygons->empty())
521	{
522	PolygonContainer *frontPolys = new PolygonContainer();
523	PolygonContainer *backPolys = new PolygonContainer();
524	PolygonContainer coincident;
525
526	int splits = 0;
527
528	// split viewcell polygons with respect to split plane
529	splits += SplitPolygons(interior->GetPlane(),
530	*tData.mPolygons,
531	*frontPolys,
532	*backPolys,
533	coincident);
534
535	// extract view cells associated with the split polygons
536	ViewCell *frontViewCell = GetOrCreateOutOfBoundsCell();
537	ViewCell *backViewCell = GetOrCreateOutOfBoundsCell();
538
539	BspTraversalData frontData(interior->GetFront(),
540	frontPolys,
541	tData.mDepth + 1,
542	mOutOfBoundsCell,
543	tData.mRays,
544	tData.mPvs,
545	mUseAreaForPvs ? mBox.SurfaceArea() : mBox.GetVolume(),
546	new BspNodeGeometry());
547
548	BspTraversalData backData(interior->GetBack(),
549	backPolys,
550	tData.mDepth + 1,
551	mOutOfBoundsCell,
552	tData.mRays,
553	tData.mPvs,
554	mUseAreaForPvs ? mBox.SurfaceArea() : mBox.GetVolume(),
555	new BspNodeGeometry());
556
557	if (!mGenerateViewCells)
558	{
559	ExtractViewCells(frontData,
560	backData,
561	coincident,
562	interior->mPlane);
563	}
564
565	// don't need coincident polygons anymore
566	CLEAR_CONTAINER(coincident);
567
568	mStat.polySplits += splits;
569
570	// push the children on the stack
571	tStack.push(frontData);
572	tStack.push(backData);
573	}
574
575	// cleanup
576	DEL_PTR(tData.mPolygons);
577	DEL_PTR(tData.mRays);
578	}
579	else
580	{
581	// reached leaf => subdivide current viewcell
582	BspNode *subRoot = Subdivide(tStack, tData);
583	}
584	}
585	}
586
587	int BspTree::AddMeshToPolygons(Mesh *mesh,
588	PolygonContainer &polys,
589	MeshInstance *parent)
590	{
591	FaceContainer::const_iterator fi;
592
593	// copy the face data to polygons
594	for (fi = mesh->mFaces.begin(); fi != mesh->mFaces.end(); ++ fi)
595	{
596	Polygon3 poly = new Polygon3((fi), mesh);
597
598	if (poly->Valid(mEpsilon))
599	{
600	poly->mParent = parent; // set parent intersectable
601	polys.push_back(poly);
602	}
603	else
604	DEL_PTR(poly);
605	}
606	return (int)mesh->mFaces.size();
607	}
608
609
610	int BspTree::AddToPolygonSoup(const ViewCellContainer &viewCells,
611	PolygonContainer &polys,
612	int maxObjects)
613	{
614	int limit = (maxObjects > 0) ?
615	Min((int)viewCells.size(), maxObjects) : (int)viewCells.size();
616
617	int polysSize = 0;
618
619	for (int i = 0; i < limit; ++ i)
620	{
621	if (viewCells[i]->GetMesh()) // copy the mesh data to polygons
622	{
623	mBox.Include(viewCells[i]->GetBox()); // add to BSP tree aabb
624	polysSize += AddMeshToPolygons(viewCells[i]->GetMesh(), polys, viewCells[i]);
625	}
626	}
627
628	return polysSize;
629	}
630
631
632	int BspTree::AddToPolygonSoup(const ObjectContainer &objects,
633	PolygonContainer &polys,
634	int maxObjects,
635	bool addToBbox)
636	{
637	int limit = (maxObjects > 0) ?
638	Min((int)objects.size(), maxObjects) : (int)objects.size();
639
640	for (int i = 0; i < limit; ++i)
641	{
642	Intersectable object = objects[i];//it;
643	Mesh *mesh = NULL;
644
645	switch (object->Type()) // extract the meshes
646	{
647	case Intersectable::MESH_INSTANCE:
648	mesh = dynamic_cast<MeshInstance *>(object)->GetMesh();
649	break;
650	case Intersectable::VIEW_CELL:
651	mesh = dynamic_cast<ViewCell *>(object)->GetMesh();
652	break;
653	// TODO: handle transformed mesh instances
654	default:
655	Debug << "intersectable type not supported" << endl;
656	break;
657	}
658
659	if (mesh) // copy the mesh data to polygons
660	{
661	if (addToBbox)
662	{
663	mBox.Include(object->GetBox()); // add to BSP tree aabb
664	}
665
666	AddMeshToPolygons(mesh, polys, mOutOfBoundsCell);
667	}
668	}
669
670	return (int)polys.size();
671	}
672
673
674	void BspTree::Construct(const ViewCellContainer &viewCells)
675	{
676	mStat.nodes = 1;
677	mBox.Initialize(); // initialise bsp tree bounding box
678
679	// copy view cell meshes into one big polygon soup
680	PolygonContainer *polys = new PolygonContainer();
681	mStat.polys = AddToPolygonSoup(viewCells, *polys);
682
683	// view cells are given
684	mGenerateViewCells = false;
685	// construct tree from the view cell polygons
686	Construct(polys, new BoundedRayContainer());
687	}
688
689
690	void BspTree::Construct(const ObjectContainer &objects)
691	{
692	mStat.nodes = 1;
693	mBox.Initialize(); // initialise bsp tree bounding box
694
695	PolygonContainer *polys = new PolygonContainer();
696
697	mGenerateViewCells = true;
698	// copy mesh instance polygons into one big polygon soup
699	mStat.polys = AddToPolygonSoup(objects, *polys);
700
701	// construct tree from polygon soup
702	Construct(polys, new BoundedRayContainer());
703	}
704
705
706	void BspTree::PreprocessPolygons(PolygonContainer &polys)
707	{
708	// preprocess: throw out polygons coincident to the view space box (not needed)
709	PolygonContainer boxPolys;
710	mBox.ExtractPolys(boxPolys);
711	vector<Plane3> boxPlanes;
712
713	PolygonContainer::iterator pit, pit_end = boxPolys.end();
714
715	// extract planes of box
716	// TODO: can be done more elegantly than first extracting polygons
717	// and take their planes
718	for (pit = boxPolys.begin(); pit != pit_end; ++ pit)
719	{
720	boxPlanes.push_back((*pit)->GetSupportingPlane());
721	}
722
723	pit_end = polys.end();
724
725	for (pit = polys.begin(); pit != pit_end; ++ pit)
726	{
727	vector<Plane3>::const_iterator bit, bit_end = boxPlanes.end();
728
729	for (bit = boxPlanes.begin(); (bit != bit_end) && (*pit); ++ bit)
730	{
731	const int cf = (pit)->ClassifyPlane(bit, mEpsilon);
732
733	if (cf == Polygon3::COINCIDENT)
734	{
735	DEL_PTR(*pit);
736	//Debug << "coincident!!" << endl;
737	}
738	}
739	}
740
741	// remove deleted entries
742	for (int i = 0; i < (int)polys.size(); ++ i)
743	{
744	while (!polys[i] && (i < (int)polys.size()))
745	{
746	swap(polys[i], polys.back());
747	polys.pop_back();
748	}
749	}
750	}
751
752
753
754	void BspTree::Construct(const RayContainer &sampleRays,
755	AxisAlignedBox3 *forcedBoundingBox)
756	{
757	mStat.nodes = 1;
758	mBox.Initialize(); // initialise BSP tree bounding box
759
760	if (forcedBoundingBox)
761	mBox = *forcedBoundingBox;
762
763	PolygonContainer *polys = new PolygonContainer();
764	BoundedRayContainer *rays = new BoundedRayContainer();
765
766	RayContainer::const_iterator rit, rit_end = sampleRays.end();
767
768	// generate view cells
769	mGenerateViewCells = true;
770
771	long startTime = GetTime();
772
773	Debug << "** Extracting polygons from rays **\n";
774
775	std::map<Face , Polygon3 > facePolyMap;
776
777	//-- extract polygons intersected by the rays
778	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
779	{
780	Ray ray = rit;
781
782	// get ray-face intersection. Store polygon representing the rays together
783	// with rays intersecting the face.
784	if (!ray->intersections.empty())
785	{
786	MeshInstance obj = dynamic_cast<MeshInstance >(ray->intersections[0].mObject);
787	Face *face = obj->GetMesh()->mFaces[ray->intersections[0].mFace];
788
789	std::map<Face , Polygon3 >::iterator it = facePolyMap.find(face);
790
791	if (it != facePolyMap.end())
792	{
793	//store rays if needed for heuristics
794	if (mSplitPlaneStrategy & BLOCKED_RAYS)
795	(*it).second->mPiercingRays.push_back(ray);
796	}
797	else
798	{ //store rays if needed for heuristics
799	Polygon3 *poly = new Polygon3(face, obj->GetMesh());
800	poly->mParent = obj;
801	polys->push_back(poly);
802
803	if (mSplitPlaneStrategy & BLOCKED_RAYS)
804	poly->mPiercingRays.push_back(ray);
805
806	facePolyMap[face] = poly;
807	}
808	}
809	}
810
811	facePolyMap.clear();
812
813	// compute bounding box
814	if (!forcedBoundingBox)
815	Polygon3::IncludeInBox(*polys, mBox);
816
817	//-- store rays
818	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
819	{
820	Ray ray = rit;
821	ray->SetId(-1); // reset id
822
823	float minT, maxT;
824	if (mBox.GetRaySegment(*ray, minT, maxT))
825	rays->push_back(new BoundedRay(ray, minT, maxT));
826	}
827
828	// throw out bad polygons
829	PreprocessPolygons(*polys);
830
831	mStat.polys = (int)polys->size();
832
833	Debug << "** Finished polygon extraction **" << endl;
834	Debug << (int)polys->size() << " polys extracted from " << (int)sampleRays.size() << " rays" << endl;
835	Debug << "extraction time: " << TimeDiff(startTime, GetTime())*1e-3 << "s" << endl;
836
837	Construct(polys, rays);
838	}
839
840
841	void BspTree::Construct(const ObjectContainer &objects,
842	const RayContainer &sampleRays,
843	AxisAlignedBox3 *forcedBoundingBox)
844	{
845	mStat.nodes = 1;
846	mBox.Initialize(); // initialise BSP tree bounding box
847
848	if (forcedBoundingBox)
849	mBox = *forcedBoundingBox;
850
851	BoundedRayContainer *rays = new BoundedRayContainer();
852	PolygonContainer *polys = new PolygonContainer();
853
854	mGenerateViewCells = true;
855
856	// copy mesh instance polygons into one big polygon soup
857	mStat.polys = AddToPolygonSoup(objects, *polys, 0, !forcedBoundingBox);
858
859
860	RayContainer::const_iterator rit, rit_end = sampleRays.end();
861
862	//-- store rays
863	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
864	{
865	Ray ray = rit;
866	ray->SetId(-1); // reset id
867
868	float minT, maxT;
869	if (mBox.GetRaySegment(*ray, minT, maxT))
870	rays->push_back(new BoundedRay(ray, minT, maxT));
871	}
872
873	PreprocessPolygons(*polys);
874	Debug << "tree has " << (int)polys->size() << " polys, " << (int)sampleRays.size() << " rays" << endl;
875	Construct(polys, rays);
876	}
877
878
879	void BspTree::Construct(PolygonContainer polys, BoundedRayContainer rays)
880	{
881	BspTraversalStack tStack;
882
883	mRoot = new BspLeaf();
884
885	// constrruct root node geometry
886	BspNodeGeometry *geom = new BspNodeGeometry();
887	ConstructGeometry(mRoot, *geom);
888
889	BspTraversalData tData(mRoot,
890	polys,
891	0,
892	GetOrCreateOutOfBoundsCell(),
893	rays,
894	ComputePvsSize(*rays),
895	mUseAreaForPvs ? geom->GetArea() : geom->GetVolume(),
896	geom);
897
898	mTotalCost = tData.mPvs * tData.mProbability / mBox.GetVolume();
899	mTotalPvsSize = tData.mPvs;
900
901	mSubdivisionStats
902	<< "#ViewCells\n1\n" << endl
903	<< "#RenderCostDecrease\n0\n" << endl
904	<< "#TotalRenderCost\n" << mTotalCost << endl
905	<< "#AvgRenderCost\n" << mTotalPvsSize << endl;
906
907	tStack.push(tData);
908
909	// used for intermediate time measurements and progress
910	long interTime = GetTime();
911	int nleaves = 500;
912
913	mStat.Start();
914	cout << "Contructing bsp tree ...\n";
915	long startTime = GetTime();
916	while (!tStack.empty())
917	{
918	tData = tStack.top();
919
920	tStack.pop();
921
922	// subdivide leaf node
923	BspNode *r = Subdivide(tStack, tData);
924
925	if (r == mRoot)
926	Debug << "BSP tree construction time spent at root: "
927	<< TimeDiff(startTime, GetTime())*1e-3 << " secs" << endl;
928
929	if (mStat.Leaves() >= nleaves)
930	{
931	nleaves += 500;
932
933	cout << "leaves=" << mStat.Leaves() << endl;
934	Debug << "needed "
935	<< TimeDiff(interTime, GetTime())*1e-3
936	<< " secs to create 500 leaves" << endl;
937	interTime = GetTime();
938	}
939	}
940
941	cout << "finished\n";
942
943	mStat.Stop();
944	}
945
946
947	bool BspTree::TerminationCriteriaMet(const BspTraversalData &data) const
948	{
949	return
950	(((int)data.mPolygons->size() <= mTermMinPolys) \|\|
951	((int)data.mRays->size() <= mTermMinRays) \|\|
952	(data.mPvs <= mTermMinPvs) \|\|
953	(data.mProbability <= mTermMinProbability) \|\|
954	(data.mDepth >= mTermMaxDepth) \|\|
955	(mStat.Leaves() >= mMaxViewCells) \|\|
956	(data.GetAvgRayContribution() > mTermMaxRayContribution));
957	}
958
959
960	BspNode *BspTree::Subdivide(BspTraversalStack &tStack, BspTraversalData &tData)
961	{
962	//-- terminate traversal
963	if (TerminationCriteriaMet(tData))
964	{
965	BspLeaf leaf = dynamic_cast<BspLeaf >(tData.mNode);
966
967	BspViewCell *viewCell;
968
969	// generate new view cell for each leaf
970	if (mGenerateViewCells)
971	viewCell = new BspViewCell();
972	else
973	// add view cell to leaf
974	viewCell = dynamic_cast<BspViewCell *>(tData.mViewCell);
975
976	leaf->SetViewCell(viewCell);
977	viewCell->mLeaf = leaf;
978
979	if (mUseAreaForPvs)
980	viewCell->SetArea(tData.mProbability);
981	else
982	viewCell->SetVolume(tData.mProbability);
983
984	//-- add pvs
985	if (viewCell != mOutOfBoundsCell)
986	{
987	int conSamp = 0, sampCon = 0;
988	AddToPvs(leaf, *tData.mRays, conSamp, sampCon);
989
990	mStat.contributingSamples += conSamp;
991	mStat.sampleContributions += sampCon;
992	}
993
994	EvaluateLeafStats(tData);
995
996	//-- clean up
997
998	// discard polygons
999	CLEAR_CONTAINER(*tData.mPolygons);
1000	// discard rays
1001	CLEAR_CONTAINER(*tData.mRays);
1002
1003	DEL_PTR(tData.mPolygons);
1004	DEL_PTR(tData.mRays);
1005	DEL_PTR(tData.mGeometry);
1006
1007	return leaf;
1008	}
1009
1010	//-- continue subdivision
1011	PolygonContainer coincident;
1012
1013	BspTraversalData tFrontData(NULL, new PolygonContainer(), tData.mDepth + 1, mOutOfBoundsCell,
1014	new BoundedRayContainer(), 0, 0, new BspNodeGeometry());
1015	BspTraversalData tBackData(NULL, new PolygonContainer(), tData.mDepth + 1, mOutOfBoundsCell,
1016	new BoundedRayContainer(), 0, 0, new BspNodeGeometry());
1017
1018
1019	// create new interior node and two leaf nodes
1020	BspInterior *interior =
1021	SubdivideNode(tData, tFrontData, tBackData, coincident);
1022
1023
1024	if (1)
1025	{
1026	int pvsData = tData.mPvs;
1027
1028	float cData = (float)pvsData * tData.mProbability;
1029	float cFront = (float)tFrontData.mPvs * tFrontData.mProbability;
1030	float cBack = (float)tBackData.mPvs * tBackData.mProbability;
1031
1032	float costDecr = (cFront + cBack - cData) / mBox.GetVolume();
1033
1034	mTotalCost += costDecr;
1035	mTotalPvsSize += tFrontData.mPvs + tBackData.mPvs - pvsData;
1036
1037	mSubdivisionStats
1038	<< "#ViewCells\n" << mStat.Leaves() << endl
1039	<< "#RenderCostDecrease\n" << -costDecr << endl
1040	<< "#TotalRenderCost\n" << mTotalCost << endl
1041	<< "#AvgRenderCost\n" << mTotalPvsSize / mStat.Leaves() << endl;
1042	}
1043
1044	// extract view cells from coincident polygons according to plane normal
1045	// only if front or back polygons are empty
1046	if (!mGenerateViewCells)
1047	{
1048	ExtractViewCells(tFrontData,
1049	tBackData,
1050	coincident,
1051	interior->mPlane);
1052	}
1053
1054	// don't need coincident polygons anymory
1055	CLEAR_CONTAINER(coincident);
1056
1057	// push the children on the stack
1058	tStack.push(tFrontData);
1059	tStack.push(tBackData);
1060
1061	// cleanup
1062	DEL_PTR(tData.mNode);
1063
1064	DEL_PTR(tData.mPolygons);
1065	DEL_PTR(tData.mRays);
1066	DEL_PTR(tData.mGeometry);
1067
1068	return interior;
1069	}
1070
1071
1072	void BspTree::ExtractViewCells(BspTraversalData &frontData,
1073	BspTraversalData &backData,
1074	const PolygonContainer &coincident,
1075	const Plane3 &splitPlane) const
1076	{
1077	// if not empty, tree is further subdivided => don't have to find view cell
1078	bool foundFront = !frontData.mPolygons->empty();
1079	bool foundBack = !frontData.mPolygons->empty();
1080
1081	PolygonContainer::const_iterator it =
1082	coincident.begin(), it_end = coincident.end();
1083
1084	//-- find first view cells in front and back leafs
1085	for (; !(foundFront && foundBack) && (it != it_end); ++ it)
1086	{
1087	if (DotProd((*it)->GetNormal(), splitPlane.mNormal) > 0)
1088	{
1089	backData.mViewCell = dynamic_cast<ViewCell >((it)->mParent);
1090	foundBack = true;
1091	}
1092	else
1093	{
1094	frontData.mViewCell = dynamic_cast<ViewCell >((it)->mParent);
1095	foundFront = true;
1096	}
1097	}
1098	}
1099
1100
1101	BspInterior *BspTree::SubdivideNode(BspTraversalData &tData,
1102	BspTraversalData &frontData,
1103	BspTraversalData &backData,
1104	PolygonContainer &coincident)
1105	{
1106	mStat.nodes += 2;
1107
1108	BspLeaf leaf = dynamic_cast<BspLeaf >(tData.mNode);
1109
1110
1111
1112	// select subdivision plane
1113	BspInterior *interior =
1114	new BspInterior(SelectPlane(leaf, tData));
1115
1116
1117	#ifdef _DEBUG
1118	Debug << interior << endl;
1119	#endif
1120
1121
1122	// subdivide rays into front and back rays
1123	SplitRays(interior->mPlane, tData.mRays, frontData.mRays, *backData.mRays);
1124
1125
1126
1127	// subdivide polygons with plane
1128	mStat.polySplits += SplitPolygons(interior->GetPlane(),
1129	*tData.mPolygons,
1130	*frontData.mPolygons,
1131	*backData.mPolygons,
1132	coincident);
1133
1134
1135
1136	// compute pvs
1137	frontData.mPvs = ComputePvsSize(*frontData.mRays);
1138	backData.mPvs = ComputePvsSize(*backData.mRays);
1139
1140	// split geometry and compute area
1141	if (1)
1142	{
1143	tData.mGeometry->SplitGeometry(*frontData.mGeometry,
1144	*backData.mGeometry,
1145	interior->mPlane,
1146	mBox,
1147	//0.000000000001);
1148	mEpsilon);
1149
1150
1151	if (mUseAreaForPvs)
1152	{
1153	frontData.mProbability = frontData.mGeometry->GetArea();
1154	backData.mProbability = backData.mGeometry->GetArea();
1155	}
1156	else
1157	{
1158	frontData.mProbability = frontData.mGeometry->GetVolume();
1159	backData.mProbability = tData.mProbability - frontData.mProbability;
1160	}
1161	}
1162
1163	//-- create front and back leaf
1164
1165	BspInterior *parent = leaf->GetParent();
1166
1167	// replace a link from node's parent
1168	if (!leaf->IsRoot())
1169	{
1170	parent->ReplaceChildLink(leaf, interior);
1171	interior->SetParent(parent);
1172	}
1173	else // new root
1174	{
1175	mRoot = interior;
1176	}
1177
1178	// and setup child links
1179	interior->SetupChildLinks(new BspLeaf(interior), new BspLeaf(interior));
1180
1181	frontData.mNode = interior->GetFront();
1182	backData.mNode = interior->GetBack();
1183
1184	interior->mTimeStamp = leaf->mTimeStamp;
1185	frontData.mNode->mTimeStamp = mTimeStamp;
1186	backData.mNode->mTimeStamp = mTimeStamp ++;
1187
1188	Debug << "time stamp: " << mTimeStamp << endl;
1189	//DEL_PTR(leaf);
1190	return interior;
1191	}
1192
1193
1194	void BspTree::SortSplitCandidates(const PolygonContainer &polys,
1195	const int axis,
1196	vector<SortableEntry> &splitCandidates) const
1197	{
1198	splitCandidates.clear();
1199
1200	int requestedSize = 2 * (int)polys.size();
1201	// creates a sorted split candidates array
1202	splitCandidates.reserve(requestedSize);
1203
1204	PolygonContainer::const_iterator it, it_end = polys.end();
1205
1206	AxisAlignedBox3 box;
1207
1208	// insert all queries
1209	for(it = polys.begin(); it != it_end; ++ it)
1210	{
1211	box.Initialize();
1212	box.Include((it));
1213
1214	splitCandidates.push_back(SortableEntry(SortableEntry::POLY_MIN, box.Min(axis), *it));
1215	splitCandidates.push_back(SortableEntry(SortableEntry::POLY_MAX, box.Max(axis), *it));
1216	}
1217
1218	stable_sort(splitCandidates.begin(), splitCandidates.end());
1219	}
1220
1221
1222	float BspTree::BestCostRatio(const PolygonContainer &polys,
1223	const AxisAlignedBox3 &box,
1224	const int axis,
1225	float &position,
1226	int &objectsBack,
1227	int &objectsFront) const
1228	{
1229	vector<SortableEntry> splitCandidates;
1230
1231	SortSplitCandidates(polys, axis, splitCandidates);
1232
1233	// go through the lists, count the number of objects left and right
1234	// and evaluate the following cost funcion:
1235	// C = ct_div_ci + (ol + or)/queries
1236
1237	int objectsLeft = 0, objectsRight = (int)polys.size();
1238
1239	float minBox = box.Min(axis);
1240	float maxBox = box.Max(axis);
1241	float boxArea = box.SurfaceArea();
1242
1243	float minBand = minBox + mSplitBorder * (maxBox - minBox);
1244	float maxBand = minBox + (1.0f - mSplitBorder) * (maxBox - minBox);
1245
1246	float minSum = 1e20f;
1247	vector<SortableEntry>::const_iterator ci, ci_end = splitCandidates.end();
1248
1249	for(ci = splitCandidates.begin(); ci != ci_end; ++ ci)
1250	{
1251	switch ((*ci).type)
1252	{
1253	case SortableEntry::POLY_MIN:
1254	++ objectsLeft;
1255	break;
1256	case SortableEntry::POLY_MAX:
1257	-- objectsRight;
1258	break;
1259	default:
1260	break;
1261	}
1262
1263	if ((ci).value > minBand && (ci).value < maxBand)
1264	{
1265	AxisAlignedBox3 lbox = box;
1266	AxisAlignedBox3 rbox = box;
1267	lbox.SetMax(axis, (*ci).value);
1268	rbox.SetMin(axis, (*ci).value);
1269
1270	const float sum = objectsLeft * lbox.SurfaceArea() +
1271	objectsRight * rbox.SurfaceArea();
1272
1273	if (sum < minSum)
1274	{
1275	minSum = sum;
1276	position = (*ci).value;
1277
1278	objectsBack = objectsLeft;
1279	objectsFront = objectsRight;
1280	}
1281	}
1282	}
1283
1284	const float oldCost = (float)polys.size();
1285	const float newCost = mAxisAlignedCtDivCi + minSum / boxArea;
1286	const float ratio = newCost / oldCost;
1287
1288
1289	#if 0
1290	Debug << "====================" << endl;
1291	Debug << "costRatio=" << ratio << " pos=" << position<<" t=" << (position - minBox)/(maxBox - minBox)
1292	<< "\t o=(" << objectsBack << "," << objectsFront << ")" << endl;
1293	#endif
1294	return ratio;
1295	}
1296
1297	bool BspTree::SelectAxisAlignedPlane(Plane3 &plane,
1298	const PolygonContainer &polys) const
1299	{
1300	AxisAlignedBox3 box;
1301	box.Initialize();
1302
1303	// create bounding box of region
1304	Polygon3::IncludeInBox(polys, box);
1305
1306	int objectsBack = 0, objectsFront = 0;
1307	int axis = 0;
1308	float costRatio = MAX_FLOAT;
1309	Vector3 position;
1310
1311	//-- area subdivision
1312	for (int i = 0; i < 3; ++ i)
1313	{
1314	float p = 0;
1315	float r = BestCostRatio(polys, box, i, p, objectsBack, objectsFront);
1316
1317	if (r < costRatio)
1318	{
1319	costRatio = r;
1320	axis = i;
1321	position = p;
1322	}
1323	}
1324
1325	if (costRatio >= mMaxCostRatio)
1326	return false;
1327
1328	Vector3 norm(0,0,0); norm[axis] = 1.0f;
1329	plane = Plane3(norm, position);
1330
1331	return true;
1332	}
1333
1334
1335	Plane3 BspTree::SelectPlane(BspLeaf *leaf, BspTraversalData &data)
1336	{
1337	if ((!mMaxPolyCandidates \|\| data.mPolygons->empty()) &&
1338	(!mMaxRayCandidates \|\| data.mRays->empty()))
1339	{
1340	Debug << "Warning: No autopartition polygon candidate available\n";
1341
1342	// return axis aligned split
1343	AxisAlignedBox3 box;
1344	box.Initialize();
1345
1346	// create bounding box of region
1347	Polygon3::IncludeInBox(*data.mPolygons, box);
1348
1349	const int axis = box.Size().DrivingAxis();
1350	const Vector3 position = (box.Min()[axis] + box.Max()[axis]) * 0.5f;
1351
1352	Vector3 norm(0,0,0); norm[axis] = 1.0f;
1353	return Plane3(norm, position);
1354	}
1355
1356	if ((mSplitPlaneStrategy & AXIS_ALIGNED) &&
1357	((int)data.mPolygons->size() > mTermMinPolysForAxisAligned) &&
1358	((int)data.mRays->size() > mTermMinRaysForAxisAligned) &&
1359	((mTermMinObjectsForAxisAligned < 0) \|\|
1360	(Polygon3::ParentObjectsSize(*data.mPolygons) > mTermMinObjectsForAxisAligned)))
1361	{
1362	Plane3 plane;
1363	if (SelectAxisAlignedPlane(plane, *data.mPolygons))
1364	return plane;
1365	}
1366
1367	// simplest strategy: just take next polygon
1368	if (mSplitPlaneStrategy & RANDOM_POLYGON)
1369	{
1370	if (!data.mPolygons->empty())
1371	{
1372	Polygon3 *nextPoly =
1373	(*data.mPolygons)[(int)RandomValue(0, (Real)((int)data.mPolygons->size() - 1))];
1374	return nextPoly->GetSupportingPlane();
1375	}
1376	else
1377	{
1378	const int candidateIdx = (int)RandomValue(0, (Real)((int)data.mRays->size() - 1));
1379	BoundedRay bRay = (data.mRays)[candidateIdx];
1380
1381	Ray *ray = bRay->mRay;
1382
1383	const Vector3 minPt = ray->Extrap(bRay->mMinT);
1384	const Vector3 maxPt = ray->Extrap(bRay->mMaxT);
1385
1386	const Vector3 pt = (maxPt + minPt) * 0.5;
1387
1388	const Vector3 normal = ray->GetDir();
1389
1390	return Plane3(normal, pt);
1391	}
1392
1393	return Plane3();
1394	}
1395
1396	// use heuristics to find appropriate plane
1397	return SelectPlaneHeuristics(leaf, data);
1398	}
1399
1400
1401	Plane3 BspTree::ChooseCandidatePlane(const BoundedRayContainer &rays) const
1402	{
1403	const int candidateIdx = (int)RandomValue(0, (Real)((int)rays.size() - 1));
1404	BoundedRay *bRay = rays[candidateIdx];
1405	Ray *ray = bRay->mRay;
1406
1407	const Vector3 minPt = ray->Extrap(bRay->mMinT);
1408	const Vector3 maxPt = ray->Extrap(bRay->mMaxT);
1409
1410	const Vector3 pt = (maxPt + minPt) * 0.5;
1411
1412	const Vector3 normal = ray->GetDir();
1413
1414	return Plane3(normal, pt);
1415	}
1416
1417	Plane3 BspTree::ChooseCandidatePlane2(const BoundedRayContainer &rays) const
1418	{
1419	Vector3 pt[3];
1420	int idx[3];
1421	int cmaxT = 0;
1422	int cminT = 0;
1423	bool chooseMin = false;
1424
1425	for (int j = 0; j < 3; j ++)
1426	{
1427	idx[j] = (int)RandomValue(0, Real((int)rays.size() * 2 - 1));
1428
1429	if (idx[j] >= (int)rays.size())
1430	{
1431	idx[j] -= (int)rays.size();
1432	chooseMin = (cminT < 2);
1433	}
1434	else
1435	chooseMin = (cmaxT < 2);
1436
1437	BoundedRay *bRay = rays[idx[j]];
1438	pt[j] = chooseMin ? bRay->mRay->Extrap(bRay->mMinT) :
1439	bRay->mRay->Extrap(bRay->mMaxT);
1440	}
1441
1442	return Plane3(pt[0], pt[1], pt[2]);
1443	}
1444
1445	Plane3 BspTree::ChooseCandidatePlane3(const BoundedRayContainer &rays) const
1446	{
1447	Vector3 pt[3];
1448
1449	int idx1 = (int)RandomValue(0, (Real)((int)rays.size() - 1));
1450	int idx2 = (int)RandomValue(0, (Real)((int)rays.size() - 1));
1451
1452	// check if rays different
1453	if (idx1 == idx2)
1454	idx2 = (idx2 + 1) % (int)rays.size();
1455
1456	const BoundedRay *ray1 = rays[idx1];
1457	const BoundedRay *ray2 = rays[idx2];
1458
1459	// normal vector of the plane parallel to both lines
1460	const Vector3 norm =
1461	Normalize(CrossProd(ray1->mRay->GetDir(), ray2->mRay->GetDir()));
1462
1463	const Vector3 orig1 = ray1->mRay->Extrap(ray1->mMinT);
1464	const Vector3 orig2 = ray2->mRay->Extrap(ray2->mMinT);
1465
1466	// vector from line 1 to line 2
1467	const Vector3 vd = orig1 - orig2;
1468
1469	// project vector on normal to get distance
1470	const float dist = DotProd(vd, norm);
1471
1472	// point on plane lies halfway between the two planes
1473	const Vector3 planePt = orig1 + norm * dist * 0.5;
1474
1475	return Plane3(norm, planePt);
1476	}
1477
1478
1479	Plane3 BspTree::SelectPlaneHeuristics(BspLeaf *leaf, BspTraversalData &data)
1480	{
1481	float lowestCost = MAX_FLOAT;
1482	Plane3 bestPlane;
1483	// intermediate plane
1484	Plane3 plane;
1485
1486	const int limit = Min((int)data.mPolygons->size(), mMaxPolyCandidates);
1487	int maxIdx = (int)data.mPolygons->size();
1488
1489	for (int i = 0; i < limit; ++ i)
1490	{
1491	// assure that no index is taken twice
1492	const int candidateIdx = (int)RandomValue(0, (Real)(-- maxIdx));
1493
1494	Polygon3 poly = (data.mPolygons)[candidateIdx];
1495
1496	// swap candidate to the end to avoid testing same plane
1497	std::swap((data.mPolygons)[maxIdx], (data.mPolygons)[candidateIdx]);
1498	//Polygon3 poly = (data.mPolygons)[(int)RandomValue(0, (int)polys.size() - 1)];
1499
1500	// evaluate current candidate
1501	const float candidateCost =
1502	SplitPlaneCost(poly->GetSupportingPlane(), data);
1503
1504	if (candidateCost < lowestCost)
1505	{
1506	bestPlane = poly->GetSupportingPlane();
1507	lowestCost = candidateCost;
1508	}
1509	}
1510
1511	//-- choose candidate planes extracted from rays
1512	for (int i = 0; i < mMaxRayCandidates; ++ i)
1513	{
1514	plane = ChooseCandidatePlane3(*data.mRays);
1515	const float candidateCost = SplitPlaneCost(plane, data);
1516
1517	if (candidateCost < lowestCost)
1518	{
1519	bestPlane = plane;
1520	lowestCost = candidateCost;
1521	}
1522	}
1523
1524	#ifdef _DEBUG
1525	Debug << "plane lowest cost: " << lowestCost << endl;
1526	#endif
1527
1528	return bestPlane;
1529	}
1530
1531
1532	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1533	const PolygonContainer &polys) const
1534	{
1535	float val = 0;
1536
1537	float sumBalancedPolys = 0;
1538	float sumSplits = 0;
1539	float sumPolyArea = 0;
1540	float sumBalancedViewCells = 0;
1541	float sumBlockedRays = 0;
1542	float totalBlockedRays = 0;
1543	//float totalArea = 0;
1544	int totalViewCells = 0;
1545
1546	// need three unique ids for each type of view cell
1547	// for balanced view cells criterium
1548	ViewCell::NewMail();
1549	const int backId = ViewCell::sMailId;
1550	ViewCell::NewMail();
1551	const int frontId = ViewCell::sMailId;
1552	ViewCell::NewMail();
1553	const int frontAndBackId = ViewCell::sMailId;
1554
1555	bool useRand;
1556	int limit;
1557
1558	// choose test polyongs randomly if over threshold
1559	if ((int)polys.size() > mMaxTests)
1560	{
1561	useRand = true;
1562	limit = mMaxTests;
1563	}
1564	else
1565	{
1566	useRand = false;
1567	limit = (int)polys.size();
1568	}
1569
1570	for (int i = 0; i < limit; ++ i)
1571	{
1572	const int testIdx = useRand ? (int)RandomValue(0, (Real)(limit - 1)) : i;
1573
1574	Polygon3 *poly = polys[testIdx];
1575
1576	const int classification =
1577	poly->ClassifyPlane(candidatePlane, mEpsilon);
1578
1579	if (mSplitPlaneStrategy & BALANCED_POLYS)
1580	sumBalancedPolys += sBalancedPolysTable[classification];
1581
1582	if (mSplitPlaneStrategy & LEAST_SPLITS)
1583	sumSplits += sLeastPolySplitsTable[classification];
1584
1585	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
1586	{
1587	if (classification == Polygon3::COINCIDENT)
1588	sumPolyArea += poly->GetArea();
1589	//totalArea += area;
1590	}
1591
1592	if (mSplitPlaneStrategy & BLOCKED_RAYS)
1593	{
1594	const float blockedRays = (float)poly->mPiercingRays.size();
1595
1596	if (classification == Polygon3::COINCIDENT)
1597	sumBlockedRays += blockedRays;
1598
1599	totalBlockedRays += blockedRays;
1600	}
1601
1602	// assign view cells to back or front according to classificaion
1603	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
1604	{
1605	MeshInstance *viewCell = poly->mParent;
1606
1607	// assure that we only count a view cell
1608	// once for the front and once for the back side of the plane
1609	if (classification == Polygon3::FRONT_SIDE)
1610	{
1611	if ((viewCell->mMailbox != frontId) &&
1612	(viewCell->mMailbox != frontAndBackId))
1613	{
1614	sumBalancedViewCells += 1.0;
1615
1616	if (viewCell->mMailbox != backId)
1617	viewCell->mMailbox = frontId;
1618	else
1619	viewCell->mMailbox = frontAndBackId;
1620
1621	++ totalViewCells;
1622	}
1623	}
1624	else if (classification == Polygon3::BACK_SIDE)
1625	{
1626	if ((viewCell->mMailbox != backId) &&
1627	(viewCell->mMailbox != frontAndBackId))
1628	{
1629	sumBalancedViewCells -= 1.0;
1630
1631	if (viewCell->mMailbox != frontId)
1632	viewCell->mMailbox = backId;
1633	else
1634	viewCell->mMailbox = frontAndBackId;
1635
1636	++ totalViewCells;
1637	}
1638	}
1639	}
1640	}
1641
1642	const float polysSize = (float)polys.size() + Limits::Small;
1643
1644	// all values should be approx. between 0 and 1 so they can be combined
1645	// and scaled with the factors according to their importance
1646	if (mSplitPlaneStrategy & BALANCED_POLYS)
1647	val += mBalancedPolysFactor * fabs(sumBalancedPolys) / polysSize;
1648
1649	if (mSplitPlaneStrategy & LEAST_SPLITS)
1650	val += mLeastSplitsFactor * sumSplits / polysSize;
1651
1652	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
1653	// HACK: polys.size should be total area so scaling is between 0 and 1
1654	val += mLargestPolyAreaFactor * (float)polys.size() / sumPolyArea;
1655
1656	if (mSplitPlaneStrategy & BLOCKED_RAYS)
1657	if (totalBlockedRays != 0)
1658	val += mBlockedRaysFactor * (totalBlockedRays - sumBlockedRays) / totalBlockedRays;
1659
1660	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
1661	val += mBalancedViewCellsFactor * fabs(sumBalancedViewCells) /
1662	((float)totalViewCells + Limits::Small);
1663
1664	return val;
1665	}
1666
1667
1668	inline void BspTree::GenerateUniqueIdsForPvs()
1669	{
1670	ViewCell::NewMail(); sBackId = ViewCell::sMailId;
1671	ViewCell::NewMail(); sFrontId = ViewCell::sMailId;
1672	ViewCell::NewMail(); sFrontAndBackId = ViewCell::sMailId;
1673	}
1674
1675
1676	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1677	const BoundedRayContainer &rays,
1678	const int pvs,
1679	const float probability,
1680	const BspNodeGeometry &cell) const
1681	{
1682	float val = 0;
1683
1684	float sumBalancedRays = 0;
1685	float sumRaySplits = 0;
1686
1687	int frontPvs = 0;
1688	int backPvs = 0;
1689
1690	// probability that view point lies in child
1691	float pOverall = 0;
1692	float pFront = 0;
1693	float pBack = 0;
1694
1695	const bool pvsUseLen = false;
1696
1697	if (mSplitPlaneStrategy & PVS)
1698	{
1699	// create unique ids for pvs heuristics
1700	GenerateUniqueIdsForPvs();
1701
1702	// construct child geometry with regard to the candidate split plane
1703	BspNodeGeometry frontCell;
1704	BspNodeGeometry backCell;
1705
1706	cell.SplitGeometry(frontCell,
1707	backCell,
1708	candidatePlane,
1709	mBox,
1710	mEpsilon);
1711
1712	if (mUseAreaForPvs)
1713	{
1714	pFront = frontCell.GetArea();
1715	pBack = backCell.GetArea();
1716	}
1717	else
1718	{
1719	pFront = frontCell.GetVolume();
1720	pBack = pOverall - pFront;
1721	}
1722
1723
1724	pOverall = probability;
1725	}
1726
1727	bool useRand;
1728	int limit;
1729
1730	// choose test polyongs randomly if over threshold
1731	if ((int)rays.size() > mMaxTests)
1732	{
1733	useRand = true;
1734	limit = mMaxTests;
1735	}
1736	else
1737	{
1738	useRand = false;
1739	limit = (int)rays.size();
1740	}
1741
1742	for (int i = 0; i < limit; ++ i)
1743	{
1744	const int testIdx = useRand ? (int)RandomValue(0, (Real)(limit - 1)) : i;
1745
1746	BoundedRay *bRay = rays[testIdx];
1747
1748	Ray *ray = bRay->mRay;
1749	const float minT = bRay->mMinT;
1750	const float maxT = bRay->mMaxT;
1751
1752	Vector3 entP, extP;
1753
1754	const int cf =
1755	ray->ClassifyPlane(candidatePlane, minT, maxT, entP, extP);
1756
1757	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
1758	{
1759	sumBalancedRays += sBalancedRaysTable[cf];
1760	}
1761
1762	if (mSplitPlaneStrategy & BALANCED_RAYS)
1763	{
1764	sumRaySplits += sLeastRaySplitsTable[cf];
1765	}
1766
1767	if (mSplitPlaneStrategy & PVS)
1768	{
1769	// in case the ray intersects an object
1770	// assure that we only count the object
1771	// once for the front and once for the back side of the plane
1772
1773	// add the termination object
1774	if (!ray->intersections.empty())
1775	AddObjToPvs(ray->intersections[0].mObject, cf, frontPvs, backPvs);
1776
1777	// add the source object
1778	AddObjToPvs(ray->sourceObject.mObject, cf, frontPvs, backPvs);
1779	}
1780	}
1781
1782	const float raysSize = (float)rays.size() + Limits::Small;
1783
1784	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
1785	val += mLeastRaySplitsFactor * sumRaySplits / raysSize;
1786
1787	if (mSplitPlaneStrategy & BALANCED_RAYS)
1788	val += mBalancedRaysFactor * fabs(sumBalancedRays) / raysSize;
1789
1790	const float denom = pOverall * (float)pvs * 2.0f + Limits::Small;
1791
1792	if (mSplitPlaneStrategy & PVS)
1793	{
1794	val += mPvsFactor * (frontPvs * pFront + (backPvs * pBack)) / denom;
1795
1796	// give penalty to unbalanced split
1797	if (0)
1798	if (((pFront * 0.2 + Limits::Small) > pBack) \|\|
1799	(pFront < (pBack * 0.2 + Limits::Small)))
1800	val += 0.5;
1801	}
1802
1803
1804	#ifdef _DEBUG
1805	Debug << "totalpvs: " << pvs << " ptotal: " << pOverall
1806	<< " frontpvs: " << frontPvs << " pFront: " << pFront
1807	<< " backpvs: " << backPvs << " pBack: " << pBack << endl << endl;
1808	#endif
1809
1810	return val;
1811	}
1812
1813	void BspTree::AddObjToPvs(Intersectable *obj,
1814	const int cf,
1815	int &frontPvs,
1816	int &backPvs) const
1817	{
1818	if (!obj)
1819	return;
1820	// TODO: does this really belong to no pvs?
1821	//if (cf == Ray::COINCIDENT) return;
1822
1823	// object belongs to both PVS
1824	const bool bothSides = (cf == Ray::FRONT_BACK) \|\|
1825	(cf == Ray::BACK_FRONT) \|\|
1826	(cf == Ray::COINCIDENT);
1827
1828	if ((cf == Ray::FRONT) \|\| bothSides)
1829	{
1830	if ((obj->mMailbox != sFrontId) &&
1831	(obj->mMailbox != sFrontAndBackId))
1832	{
1833	++ frontPvs;
1834
1835	if (obj->mMailbox == sBackId)
1836	obj->mMailbox = sFrontAndBackId;
1837	else
1838	obj->mMailbox = sFrontId;
1839	}
1840	}
1841
1842	if ((cf == Ray::BACK) \|\| bothSides)
1843	{
1844	if ((obj->mMailbox != sBackId) &&
1845	(obj->mMailbox != sFrontAndBackId))
1846	{
1847	++ backPvs;
1848
1849	if (obj->mMailbox == sFrontId)
1850	obj->mMailbox = sFrontAndBackId;
1851	else
1852	obj->mMailbox = sBackId;
1853	}
1854	}
1855	}
1856
1857
1858	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1859	BspTraversalData &data) const
1860	{
1861	float val = 0;
1862
1863	if (mSplitPlaneStrategy & VERTICAL_AXIS)
1864	{
1865	Vector3 tinyAxis(0,0,0); tinyAxis[mBox.Size().TinyAxis()] = 1.0f;
1866	// we put a penalty on the dot product between the "tiny" vertical axis
1867	// and the split plane axis
1868	val += mVerticalSplitsFactor *
1869	fabs(DotProd(candidatePlane.mNormal, tinyAxis));
1870	}
1871
1872	// the following criteria loop over all polygons to find the cost value
1873	if ((mSplitPlaneStrategy & BALANCED_POLYS) \|\|
1874	(mSplitPlaneStrategy & LEAST_SPLITS) \|\|
1875	(mSplitPlaneStrategy & LARGEST_POLY_AREA) \|\|
1876	(mSplitPlaneStrategy & BALANCED_VIEW_CELLS) \|\|
1877	(mSplitPlaneStrategy & BLOCKED_RAYS))
1878	{
1879	val += SplitPlaneCost(candidatePlane, *data.mPolygons);
1880	}
1881
1882	// the following criteria loop over all rays to find the cost value
1883	if ((mSplitPlaneStrategy & BALANCED_RAYS) \|\|
1884	(mSplitPlaneStrategy & LEAST_RAY_SPLITS) \|\|
1885	(mSplitPlaneStrategy & PVS))
1886	{
1887	val += SplitPlaneCost(candidatePlane, *data.mRays, data.mPvs,
1888	data.mProbability, *data.mGeometry);
1889	}
1890
1891	// return linear combination of the sums
1892	return val;
1893	}
1894
1895	void BspTree::CollectLeaves(vector<BspLeaf *> &leaves) const
1896	{
1897	stack<BspNode *> nodeStack;
1898	nodeStack.push(mRoot);
1899
1900	while (!nodeStack.empty())
1901	{
1902	BspNode *node = nodeStack.top();
1903
1904	nodeStack.pop();
1905
1906	if (node->IsLeaf())
1907	{
1908	BspLeaf leaf = (BspLeaf )node;
1909	leaves.push_back(leaf);
1910	}
1911	else
1912	{
1913	BspInterior interior = dynamic_cast<BspInterior >(node);
1914
1915	nodeStack.push(interior->GetBack());
1916	nodeStack.push(interior->GetFront());
1917	}
1918	}
1919	}
1920
1921
1922	AxisAlignedBox3 BspTree::GetBoundingBox() const
1923	{
1924	return mBox;
1925	}
1926
1927
1928	void BspTree::EvaluateLeafStats(const BspTraversalData &data)
1929	{
1930	// the node became a leaf -> evaluate stats for leafs
1931	BspLeaf leaf = dynamic_cast<BspLeaf >(data.mNode);
1932
1933	// store maximal and minimal depth
1934	if (data.mDepth > mStat.maxDepth)
1935	mStat.maxDepth = data.mDepth;
1936
1937	if (data.mDepth < mStat.minDepth)
1938	mStat.minDepth = data.mDepth;
1939
1940	// accumulate depth to compute average depth
1941	mStat.accumDepth += data.mDepth;
1942	// accumulate rays to compute rays / leaf
1943	mStat.accumRays += (int)data.mRays->size();
1944
1945	if (data.mDepth >= mTermMaxDepth)
1946	++ mStat.maxDepthNodes;
1947
1948	if (data.mPvs < mTermMinPvs)
1949	++ mStat.minPvsNodes;
1950
1951	if ((int)data.mRays->size() < mTermMinRays)
1952	++ mStat.minRaysNodes;
1953
1954	if (data.GetAvgRayContribution() > mTermMaxRayContribution)
1955	++ mStat.maxRayContribNodes;
1956
1957	if (data.mProbability <= mTermMinProbability)
1958	++ mStat.minProbabilityNodes;
1959
1960	#ifdef _DEBUG
1961	Debug << "BSP stats: "
1962	<< "Depth: " << data.mDepth << " (max: " << mTermMaxDepth << "), "
1963	<< "PVS: " << data.mPvs << " (min: " << mTermMinPvs << "), "
1964	<< "Probability: " << data.mProbability << " (min: " << mTermMinProbability << "), "
1965	<< "#polygons: " << (int)data.mPolygons->size() << " (max: " << mTermMinPolys << "), "
1966	<< "#rays: " << (int)data.mRays->size() << " (max: " << mTermMinRays << "), "
1967	<< "#pvs: " << leaf->GetViewCell()->GetPvs().GetSize() << "=, "
1968	<< "#avg ray contrib (pvs): " << (float)data.mPvs / (float)data.mRays->size() << endl;
1969	#endif
1970	}
1971
1972	int
1973	BspTree::_CastRay(Ray &ray)
1974	{
1975	int hits = 0;
1976
1977	stack<BspRayTraversalData> tStack;
1978
1979	float maxt, mint;
1980
1981	if (!mBox.GetRaySegment(ray, mint, maxt))
1982	return 0;
1983
1984	ViewCell::NewMail();
1985
1986	Vector3 entp = ray.Extrap(mint);
1987	Vector3 extp = ray.Extrap(maxt);
1988
1989	BspNode *node = mRoot;
1990	BspNode *farChild = NULL;
1991
1992	while (1)
1993	{
1994	if (!node->IsLeaf())
1995	{
1996	BspInterior in = dynamic_cast<BspInterior >(node);
1997
1998	Plane3 splitPlane = in->GetPlane();
1999	const int entSide = splitPlane.Side(entp);
2000	const int extSide = splitPlane.Side(extp);
2001
2002	if (entSide < 0)
2003	{
2004	node = in->GetBack();
2005
2006	if(extSide <= 0) // plane does not split ray => no far child
2007	continue;
2008
2009	farChild = in->GetFront(); // plane splits ray
2010
2011	} else if (entSide > 0)
2012	{
2013	node = in->GetFront();
2014
2015	if (extSide >= 0) // plane does not split ray => no far child
2016	continue;
2017
2018	farChild = in->GetBack(); // plane splits ray
2019	}
2020	else // ray and plane are coincident
2021	{
2022	// WHAT TO DO IN THIS CASE ?
2023	//break;
2024	node = in->GetFront();
2025	continue;
2026	}
2027
2028	// push data for far child
2029	tStack.push(BspRayTraversalData(farChild, extp, maxt));
2030
2031	// find intersection of ray segment with plane
2032	float t;
2033	extp = splitPlane.FindIntersection(ray.GetLoc(), extp, &t);
2034	maxt *= t;
2035
2036	} else // reached leaf => intersection with view cell
2037	{
2038	BspLeaf leaf = dynamic_cast<BspLeaf >(node);
2039
2040	if (!leaf->mViewCell->Mailed())
2041	{
2042	//ray.bspIntersections.push_back(Ray::BspIntersection(maxt, leaf));
2043	leaf->mViewCell->Mail();
2044	++ hits;
2045	}
2046
2047	//-- fetch the next far child from the stack
2048	if (tStack.empty())
2049	break;
2050
2051	entp = extp;
2052	mint = maxt; // NOTE: need this?
2053
2054	if (ray.GetType() == Ray::LINE_SEGMENT && mint > 1.0f)
2055	break;
2056
2057	BspRayTraversalData &s = tStack.top();
2058
2059	node = s.mNode;
2060	extp = s.mExitPoint;
2061	maxt = s.mMaxT;
2062
2063	tStack.pop();
2064	}
2065	}
2066
2067	return hits;
2068	}
2069
2070
2071	int BspTree::CastLineSegment(const Vector3 &origin,
2072	const Vector3 &termination,
2073	vector<ViewCell *> &viewcells)
2074	{
2075	int hits = 0;
2076	stack<BspRayTraversalData> tStack;
2077
2078	float mint = 0.0f, maxt = 1.0f;
2079
2080	Intersectable::NewMail();
2081	ViewCell::NewMail();
2082
2083	Vector3 entp = origin;
2084	Vector3 extp = termination;
2085
2086	BspNode *node = mRoot;
2087	BspNode *farChild = NULL;
2088
2089	while (1)
2090	{
2091	if (!node->IsLeaf())
2092	{
2093	BspInterior in = dynamic_cast<BspInterior >(node);
2094
2095	Plane3 splitPlane = in->GetPlane();
2096
2097	const int entSide = splitPlane.Side(entp);
2098	const int extSide = splitPlane.Side(extp);
2099
2100	if (entSide < 0)
2101	{
2102	node = in->GetBack();
2103
2104	if(extSide <= 0) // plane does not split ray => no far child
2105	continue;
2106
2107	farChild = in->GetFront(); // plane splits ray
2108
2109	}
2110	else if (entSide > 0)
2111	{
2112	node = in->GetFront();
2113
2114	if (extSide >= 0) // plane does not split ray => no far child
2115	continue;
2116
2117	farChild = in->GetBack(); // plane splits ray
2118	}
2119	else // ray and plane are coincident
2120	{
2121	// NOTE: what to do if ray is coincident with plane?
2122	if (extSide < 0)
2123	node = in->GetBack();
2124	else
2125	node = in->GetFront();
2126
2127	continue; // no far child
2128	}
2129
2130	// push data for far child
2131	tStack.push(BspRayTraversalData(farChild, extp, maxt));
2132
2133	// find intersection of ray segment with plane
2134	float t;
2135	extp = splitPlane.FindIntersection(origin, extp, &t);
2136	maxt *= t;
2137	}
2138	else
2139	{
2140	// reached leaf => intersection with view cell
2141	BspLeaf leaf = dynamic_cast<BspLeaf >(node);
2142
2143	if (!leaf->mViewCell->Mailed())
2144	{
2145	viewcells.push_back(leaf->mViewCell);
2146	leaf->mViewCell->Mail();
2147	hits++;
2148	}
2149
2150	//-- fetch the next far child from the stack
2151	if (tStack.empty())
2152	break;
2153
2154	entp = extp;
2155	mint = maxt; // NOTE: need this?
2156
2157	BspRayTraversalData &s = tStack.top();
2158
2159	node = s.mNode;
2160	extp = s.mExitPoint;
2161	maxt = s.mMaxT;
2162
2163	tStack.pop();
2164	}
2165	}
2166	return hits;
2167	}
2168
2169
2170	void BspTree::CollectViewCells(ViewCellContainer &viewCells) const
2171	{
2172	stack<BspNode *> nodeStack;
2173	nodeStack.push(mRoot);
2174
2175	ViewCell::NewMail();
2176
2177	while (!nodeStack.empty())
2178	{
2179	BspNode *node = nodeStack.top();
2180	nodeStack.pop();
2181
2182	if (node->IsLeaf())
2183	{
2184	ViewCell viewCell = dynamic_cast<BspLeaf >(node)->mViewCell;
2185
2186	if (!viewCell->Mailed())
2187	{
2188	viewCell->Mail();
2189	viewCells.push_back(viewCell);
2190	}
2191	}
2192	else
2193	{
2194	BspInterior interior = dynamic_cast<BspInterior >(node);
2195
2196	nodeStack.push(interior->GetFront());
2197	nodeStack.push(interior->GetBack());
2198	}
2199	}
2200	}
2201
2202
2203	BspTreeStatistics &BspTree::GetStat()
2204	{
2205	return mStat;
2206	}
2207
2208
2209	float BspTree::AccumulatedRayLength(BoundedRayContainer &rays) const
2210	{
2211	float len = 0;
2212
2213	BoundedRayContainer::const_iterator it, it_end = rays.end();
2214
2215	for (it = rays.begin(); it != it_end; ++ it)
2216	{
2217	len += SqrDistance((it)->mRay->Extrap((it)->mMinT),
2218	(it)->mRay->Extrap((it)->mMaxT));
2219	}
2220
2221	return len;
2222	}
2223
2224
2225	int BspTree::SplitRays(const Plane3 &plane,
2226	BoundedRayContainer &rays,
2227	BoundedRayContainer &frontRays,
2228	BoundedRayContainer &backRays)
2229	{
2230	int splits = 0;
2231
2232	while (!rays.empty())
2233	{
2234	BoundedRay *bRay = rays.back();
2235	Ray *ray = bRay->mRay;
2236	float minT = bRay->mMinT;
2237	float maxT = bRay->mMaxT;
2238
2239	rays.pop_back();
2240
2241	Vector3 entP, extP;
2242
2243	const int cf =
2244	ray->ClassifyPlane(plane, minT, maxT, entP, extP);
2245
2246	// set id to ray classification
2247	ray->SetId(cf);
2248
2249	switch (cf)
2250	{
2251	case Ray::COINCIDENT: // TODO: should really discard ray?
2252	frontRays.push_back(bRay);
2253	//DEL_PTR(bRay);
2254	break;
2255	case Ray::BACK:
2256	backRays.push_back(bRay);
2257	break;
2258	case Ray::FRONT:
2259	frontRays.push_back(bRay);
2260	break;
2261	case Ray::FRONT_BACK:
2262	{
2263	// find intersection of ray segment with plane
2264	const float t = plane.FindT(ray->GetLoc(), extP);
2265
2266	const float newT = t * maxT;
2267
2268	frontRays.push_back(new BoundedRay(ray, minT, newT));
2269	backRays.push_back(new BoundedRay(ray, newT, maxT));
2270
2271	DEL_PTR(bRay);
2272	}
2273	break;
2274	case Ray::BACK_FRONT:
2275	{
2276	// find intersection of ray segment with plane
2277	const float t = plane.FindT(ray->GetLoc(), extP);
2278	const float newT = t * bRay->mMaxT;
2279
2280	backRays.push_back(new BoundedRay(ray, minT, newT));
2281	frontRays.push_back(new BoundedRay(ray, newT, maxT));
2282
2283	DEL_PTR(bRay);
2284
2285	++ splits;
2286	}
2287	break;
2288	default:
2289	Debug << "Should not come here 4" << endl;
2290	break;
2291	}
2292	}
2293
2294	return splits;
2295	}
2296
2297	void BspTree::ExtractHalfSpaces(BspNode *n, vector<Plane3> &halfSpaces) const
2298	{
2299	BspNode *lastNode;
2300	do
2301	{
2302	lastNode = n;
2303
2304	// want to get planes defining geometry of this node => don't take
2305	// split plane of node itself
2306	n = n->GetParent();
2307
2308	if (n)
2309	{
2310	BspInterior interior = dynamic_cast<BspInterior >(n);
2311	Plane3 halfSpace = dynamic_cast<BspInterior *>(interior)->GetPlane();
2312
2313	if (interior->GetFront() != lastNode)
2314	halfSpace.ReverseOrientation();
2315
2316	halfSpaces.push_back(halfSpace);
2317	}
2318	}
2319	while (n);
2320	}
2321
2322
2323
2324	void BspTree::ConstructGeometry(ViewCell *vc,
2325	BspNodeGeometry &vcGeom) const
2326	{
2327	ViewCellContainer leaves;
2328	mViewCellsTree->CollectLeaves(vc, leaves);
2329
2330	ViewCellContainer::const_iterator it, it_end = leaves.end();
2331
2332	for (it = leaves.begin(); it != it_end; ++ it)
2333	{
2334	BspLeaf l = dynamic_cast<BspViewCell >(*it)->mLeaf;
2335	ConstructGeometry(l, vcGeom);
2336	}
2337	}
2338
2339
2340	void BspTree::SetViewCellsManager(ViewCellsManager *vcm)
2341	{
2342	mViewCellsManager = vcm;
2343	}
2344
2345
2346	void BspTree::ConstructGeometry(BspNode *n, BspNodeGeometry &geom) const
2347	{
2348	vector<Plane3> halfSpaces;
2349	ExtractHalfSpaces(n, halfSpaces);
2350
2351	PolygonContainer candidates;
2352
2353	// bounded planes are added to the polygons (reverse polygons
2354	// as they have to be outfacing
2355	for (int i = 0; i < (int)halfSpaces.size(); ++ i)
2356	{
2357	Polygon3 *p = GetBoundingBox().CrossSection(halfSpaces[i]);
2358
2359	if (p->Valid(mEpsilon))
2360	{
2361	candidates.push_back(p->CreateReversePolygon());
2362	DEL_PTR(p);
2363	}
2364	}
2365
2366	// add faces of bounding box (also could be faces of the cell)
2367	for (int i = 0; i < 6; ++ i)
2368	{
2369	VertexContainer vertices;
2370
2371	for (int j = 0; j < 4; ++ j)
2372	vertices.push_back(mBox.GetFace(i).mVertices[j]);
2373
2374	candidates.push_back(new Polygon3(vertices));
2375	}
2376
2377	for (int i = 0; i < (int)candidates.size(); ++ i)
2378	{
2379	// polygon is split by all other planes
2380	for (int j = 0; (j < (int)halfSpaces.size()) && candidates[i]; ++ j)
2381	{
2382	if (i == j) // polygon and plane are coincident
2383	continue;
2384
2385	VertexContainer splitPts;
2386	Polygon3 frontPoly, backPoly;
2387
2388	const int cf = candidates[i]->
2389	ClassifyPlane(halfSpaces[j], mEpsilon);
2390
2391	switch (cf)
2392	{
2393	case Polygon3::SPLIT:
2394	frontPoly = new Polygon3();
2395	backPoly = new Polygon3();
2396
2397	candidates[i]->Split(halfSpaces[j],
2398	*frontPoly,
2399	*backPoly,
2400	mEpsilon);
2401
2402	DEL_PTR(candidates[i]);
2403
2404	if (frontPoly->Valid(mEpsilon))
2405	candidates[i] = frontPoly;
2406	else
2407	DEL_PTR(frontPoly);
2408
2409	DEL_PTR(backPoly);
2410	break;
2411	case Polygon3::BACK_SIDE:
2412	DEL_PTR(candidates[i]);
2413	break;
2414	// just take polygon as it is
2415	case Polygon3::FRONT_SIDE:
2416	case Polygon3::COINCIDENT:
2417	default:
2418	break;
2419	}
2420	}
2421
2422	if (candidates[i])
2423	geom.mPolys.push_back(candidates[i]);
2424	}
2425	}
2426
2427
2428	typedef pair<BspNode , BspNodeGeometry > bspNodePair;
2429
2430
2431	int BspTree::FindNeighbors(BspNode n, vector<BspLeaf > &neighbors,
2432	const bool onlyUnmailed) const
2433	{
2434	stack<bspNodePair> nodeStack;
2435
2436	BspNodeGeometry nodeGeom;
2437	ConstructGeometry(n, nodeGeom);
2438
2439	// split planes from the root to this node
2440	// needed to verify that we found neighbor leaf
2441	// TODO: really needed?
2442	vector<Plane3> halfSpaces;
2443	ExtractHalfSpaces(n, halfSpaces);
2444
2445
2446	BspNodeGeometry *rgeom = new BspNodeGeometry();
2447	ConstructGeometry(mRoot, *rgeom);
2448
2449	nodeStack.push(bspNodePair(mRoot, rgeom));
2450
2451	while (!nodeStack.empty())
2452	{
2453	BspNode *node = nodeStack.top().first;
2454	BspNodeGeometry *geom = nodeStack.top().second;
2455
2456	nodeStack.pop();
2457
2458	if (node->IsLeaf())
2459	{
2460	// test if this leaf is in valid view space
2461	if (node->TreeValid() &&
2462	(node != n) &&
2463	(!onlyUnmailed \|\| !node->Mailed()))
2464	{
2465	bool isAdjacent = true;
2466
2467	if (1)
2468	{
2469	// test all planes of current node if still adjacent
2470	for (int i = 0; (i < halfSpaces.size()) && isAdjacent; ++ i)
2471	{
2472	const int cf =
2473	Polygon3::ClassifyPlane(geom->mPolys,
2474	halfSpaces[i],
2475	mEpsilon);
2476
2477	if (cf == Polygon3::BACK_SIDE)
2478	{
2479	isAdjacent = false;
2480	}
2481	}
2482	}
2483	else
2484	{
2485	// TODO: why is this wrong??
2486	// test all planes of current node if still adjacent
2487	for (int i = 0; (i < (int)nodeGeom.mPolys.size()) && isAdjacent; ++ i)
2488	{
2489	Polygon3 *poly = nodeGeom.mPolys[i];
2490
2491	const int cf =
2492	Polygon3::ClassifyPlane(geom->mPolys,
2493	poly->GetSupportingPlane(),
2494	mEpsilon);
2495
2496	if (cf == Polygon3::BACK_SIDE)
2497	{
2498	isAdjacent = false;
2499	}
2500	}
2501	}
2502	// neighbor was found
2503	if (isAdjacent)
2504	{
2505	neighbors.push_back(dynamic_cast<BspLeaf *>(node));
2506	}
2507	}
2508	}
2509	else
2510	{
2511	BspInterior interior = dynamic_cast<BspInterior >(node);
2512
2513	const int cf = Polygon3::ClassifyPlane(nodeGeom.mPolys,
2514	interior->GetPlane(),
2515	mEpsilon);
2516
2517	BspNode *front = interior->GetFront();
2518	BspNode *back = interior->GetBack();
2519
2520	BspNodeGeometry *fGeom = new BspNodeGeometry();
2521	BspNodeGeometry *bGeom = new BspNodeGeometry();
2522
2523	geom->SplitGeometry(*fGeom,
2524	*bGeom,
2525	interior->GetPlane(),
2526	mBox,
2527	mEpsilon);
2528
2529	if (cf == Polygon3::FRONT_SIDE)
2530	{
2531	nodeStack.push(bspNodePair(interior->GetFront(), fGeom));
2532	DEL_PTR(bGeom);
2533	}
2534	else
2535	{
2536	if (cf == Polygon3::BACK_SIDE)
2537	{
2538	nodeStack.push(bspNodePair(interior->GetBack(), bGeom));
2539	DEL_PTR(fGeom);
2540	}
2541	else
2542	{ // random decision
2543	nodeStack.push(bspNodePair(front, fGeom));
2544	nodeStack.push(bspNodePair(back, bGeom));
2545	}
2546	}
2547	}
2548
2549	DEL_PTR(geom);
2550	}
2551
2552	return (int)neighbors.size();
2553	}
2554
2555
2556	BspLeaf *BspTree::GetRandomLeaf(const Plane3 &halfspace)
2557	{
2558	stack<BspNode *> nodeStack;
2559	nodeStack.push(mRoot);
2560
2561	int mask = rand();
2562
2563	while (!nodeStack.empty())
2564	{
2565	BspNode *node = nodeStack.top();
2566	nodeStack.pop();
2567
2568	if (node->IsLeaf())
2569	{
2570	return dynamic_cast<BspLeaf *>(node);
2571	}
2572	else
2573	{
2574	BspInterior interior = dynamic_cast<BspInterior >(node);
2575	BspNode *next;
2576
2577	BspNodeGeometry geom;
2578	// todo: not very efficient: constructs full cell everytime
2579	ConstructGeometry(interior, geom);
2580
2581	const int cf = Polygon3::ClassifyPlane(geom.mPolys,
2582	halfspace,
2583	mEpsilon);
2584
2585	if (cf == Polygon3::BACK_SIDE)
2586	next = interior->GetFront();
2587	else
2588	if (cf == Polygon3::FRONT_SIDE)
2589	next = interior->GetFront();
2590	else
2591	{
2592	// random decision
2593	if (mask & 1)
2594	next = interior->GetBack();
2595	else
2596	next = interior->GetFront();
2597	mask = mask >> 1;
2598	}
2599
2600	nodeStack.push(next);
2601	}
2602	}
2603
2604	return NULL;
2605	}
2606
2607
2608	BspLeaf *BspTree::GetRandomLeaf(const bool onlyUnmailed)
2609	{
2610	stack<BspNode *> nodeStack;
2611
2612	nodeStack.push(mRoot);
2613
2614	int mask = rand();
2615
2616	while (!nodeStack.empty())
2617	{
2618	BspNode *node = nodeStack.top();
2619	nodeStack.pop();
2620
2621	if (node->IsLeaf())
2622	{
2623	if ( (!onlyUnmailed \|\| !node->Mailed()) )
2624	return dynamic_cast<BspLeaf *>(node);
2625	}
2626	else
2627	{
2628	BspInterior interior = dynamic_cast<BspInterior >(node);
2629
2630	// random decision
2631	if (mask & 1)
2632	nodeStack.push(interior->GetBack());
2633	else
2634	nodeStack.push(interior->GetFront());
2635
2636	mask = mask >> 1;
2637	}
2638	}
2639
2640	return NULL;
2641	}
2642
2643
2644	void BspTree::AddToPvs(BspLeaf *leaf,
2645	const BoundedRayContainer &rays,
2646	int &sampleContributions,
2647	int &contributingSamples)
2648	{
2649	sampleContributions = 0;
2650	contributingSamples = 0;
2651
2652	BoundedRayContainer::const_iterator it, it_end = rays.end();
2653
2654	ViewCell *vc = leaf->GetViewCell();
2655
2656	// add contributions from samples to the PVS
2657	for (it = rays.begin(); it != it_end; ++ it)
2658	{
2659	int contribution = 0;
2660	Ray ray = (it)->mRay;
2661	float relContribution;
2662	if (!ray->intersections.empty())
2663	contribution += vc->GetPvs().AddSample(ray->intersections[0].mObject,
2664	1.0f,
2665	relContribution);
2666
2667	if (ray->sourceObject.mObject)
2668	contribution += vc->GetPvs().AddSample(ray->sourceObject.mObject,
2669	1.0f,
2670	relContribution);
2671
2672	if (contribution)
2673	{
2674	sampleContributions += contribution;
2675	++ contributingSamples;
2676	}
2677
2678	//if (ray->mFlags & Ray::STORE_BSP_INTERSECTIONS)
2679	// ray->bspIntersections.push_back(Ray::BspIntersection((*it)->mMinT, this));
2680	}
2681	}
2682
2683
2684	int BspTree::ComputePvsSize(const BoundedRayContainer &rays) const
2685	{
2686	int pvsSize = 0;
2687
2688	BoundedRayContainer::const_iterator rit, rit_end = rays.end();
2689
2690	Intersectable::NewMail();
2691
2692	for (rit = rays.begin(); rit != rays.end(); ++ rit)
2693	{
2694	Ray ray = (rit)->mRay;
2695
2696	if (!ray->intersections.empty())
2697	{
2698	if (!ray->intersections[0].mObject->Mailed())
2699	{
2700	ray->intersections[0].mObject->Mail();
2701	++ pvsSize;
2702	}
2703	}
2704	if (ray->sourceObject.mObject)
2705	{
2706	if (!ray->sourceObject.mObject->Mailed())
2707	{
2708	ray->sourceObject.mObject->Mail();
2709	++ pvsSize;
2710	}
2711	}
2712	}
2713
2714	return pvsSize;
2715	}
2716
2717
2718	float BspTree::GetEpsilon() const
2719	{
2720	return mEpsilon;
2721	}
2722
2723
2724	int BspTree::CollectMergeCandidates(const vector<BspLeaf *> leaves,
2725	vector<MergeCandidate> &candidates)
2726	{
2727	BspLeaf::NewMail();
2728
2729	vector<BspLeaf *>::const_iterator it, it_end = leaves.end();
2730
2731	int numCandidates = 0;
2732
2733	// find merge candidates and push them into queue
2734	for (it = leaves.begin(); it != it_end; ++ it)
2735	{
2736	BspLeaf leaf = it;
2737
2738	// the same leaves must not be part of two merge candidates
2739	leaf->Mail();
2740	vector<BspLeaf *> neighbors;
2741	FindNeighbors(leaf, neighbors, true);
2742
2743	vector<BspLeaf *>::const_iterator nit, nit_end = neighbors.end();
2744
2745	// TODO: test if at least one ray goes from one leaf to the other
2746	for (nit = neighbors.begin(); nit != nit_end; ++ nit)
2747	{
2748	if ((*nit)->GetViewCell() != leaf->GetViewCell())
2749	{
2750	MergeCandidate mc(leaf->GetViewCell(), (*nit)->GetViewCell());
2751	candidates.push_back(mc);
2752
2753	++ numCandidates;
2754	if ((numCandidates % 1000) == 0)
2755	{
2756	cout << "collected " << numCandidates << " merge candidates" << endl;
2757	}
2758	}
2759	}
2760	}
2761
2762	Debug << "merge queue: " << (int)candidates.size() << endl;
2763	Debug << "leaves in queue: " << numCandidates << endl;
2764
2765
2766	return (int)leaves.size();
2767	}
2768
2769
2770	int BspTree::CollectMergeCandidates(const VssRayContainer &rays,
2771	vector<MergeCandidate> &candidates)
2772	{
2773	ViewCell::NewMail();
2774	long startTime = GetTime();
2775
2776	map<BspLeaf , vector<BspLeaf> > neighborMap;
2777	ViewCellContainer::const_iterator iit;
2778
2779	int numLeaves = 0;
2780
2781	BspLeaf::NewMail();
2782
2783	for (int i = 0; i < (int)rays.size(); ++ i)
2784	{
2785	VssRay *ray = rays[i];
2786
2787	// traverse leaves stored in the rays and compare and
2788	// merge consecutive leaves (i.e., the neighbors in the tree)
2789	if (ray->mViewCells.size() < 2)
2790	continue;
2791
2792	iit = ray->mViewCells.begin();
2793	BspViewCell bspVc = dynamic_cast<BspViewCell >(*(iit ++));
2794	BspLeaf *leaf = bspVc->mLeaf;
2795
2796	// traverse intersections
2797	// consecutive leaves are neighbors => add them to queue
2798	for (; iit != ray->mViewCells.end(); ++ iit)
2799	{
2800	// next pair
2801	BspLeaf *prevLeaf = leaf;
2802	bspVc = dynamic_cast<BspViewCell >(iit);
2803	leaf = bspVc->mLeaf;
2804
2805	// view space not valid or same view cell
2806	if (!leaf->TreeValid() \|\| !prevLeaf->TreeValid() \|\|
2807	(leaf->GetViewCell() == prevLeaf->GetViewCell()))
2808	continue;
2809
2810	vector<BspLeaf *> &neighbors = neighborMap[leaf];
2811
2812	bool found = false;
2813
2814	// both leaves inserted in queue already =>
2815	// look if double pair already exists
2816	if (leaf->Mailed() && prevLeaf->Mailed())
2817	{
2818	vector<BspLeaf *>::const_iterator it, it_end = neighbors.end();
2819
2820	for (it = neighbors.begin(); !found && (it != it_end); ++ it)
2821	if (*it == prevLeaf)
2822	found = true; // already in queue
2823	}
2824
2825	if (!found)
2826	{
2827	// this pair is not in map yet
2828	// => insert into the neighbor map and the queue
2829	neighbors.push_back(prevLeaf);
2830	neighborMap[prevLeaf].push_back(leaf);
2831
2832	leaf->Mail();
2833	prevLeaf->Mail();
2834
2835	MergeCandidate mc(leaf->GetViewCell(), prevLeaf->GetViewCell());
2836
2837	candidates.push_back(mc);
2838
2839	if (((int)candidates.size() % 1000) == 0)
2840	{
2841	cout << "collected " << (int)candidates.size() << " merge candidates" << endl;
2842	}
2843	}
2844	}
2845	}
2846
2847	Debug << "neighbormap size: " << (int)neighborMap.size() << endl;
2848	Debug << "merge queue: " << (int)candidates.size() << endl;
2849	Debug << "leaves in queue: " << numLeaves << endl;
2850
2851
2852	//-- collect the leaves which haven't been found by ray casting
2853	#if 0
2854	cout << "finding additional merge candidates using geometry" << endl;
2855	vector<BspLeaf *> leaves;
2856	CollectLeaves(leaves, true);
2857	Debug << "found " << (int)leaves.size() << " new leaves" << endl << endl;
2858	CollectMergeCandidates(leaves, candidates);
2859	#endif
2860
2861	return numLeaves;
2862	}
2863
2864
2865
2866
2867	/***************************************************************/
2868	/* BspNodeGeometry Implementation */
2869	/***************************************************************/
2870
2871
2872	BspNodeGeometry::BspNodeGeometry(const BspNodeGeometry &rhs)
2873	{
2874	mPolys.reserve(rhs.mPolys.size());
2875
2876	PolygonContainer::const_iterator it, it_end = rhs.mPolys.end();
2877	for (it = rhs.mPolys.begin(); it != it_end; ++ it)
2878	{
2879	Polygon3 poly = it;
2880	mPolys.push_back(new Polygon3(*poly));
2881	}
2882	}
2883
2884
2885	BspNodeGeometry::~BspNodeGeometry()
2886	{
2887	CLEAR_CONTAINER(mPolys);
2888	}
2889
2890
2891	float BspNodeGeometry::GetArea() const
2892	{
2893	return Polygon3::GetArea(mPolys);
2894	}
2895
2896
2897	float BspNodeGeometry::GetVolume() const
2898	{
2899	//-- compute volume using tetrahedralization of the geometry
2900	// and adding the volume of the single tetrahedrons
2901	float volume = 0;
2902	const float f = 1.0f / 6.0f;
2903
2904	PolygonContainer::const_iterator pit, pit_end = mPolys.end();
2905
2906	// note: can take arbitrary point, e.g., the origin. However,
2907	// we rather take the center of mass to prevents precision errors
2908	const Vector3 center = CenterOfMass();
2909
2910	for (pit = mPolys.begin(); pit != pit_end; ++ pit)
2911	{
2912	Polygon3 poly = pit;
2913	const Vector3 v0 = poly->mVertices[0] - center;
2914
2915	for (int i = 1; i < (int)poly->mVertices.size() - 1; ++ i)
2916	{
2917	const Vector3 v1 = poly->mVertices[i] - center;
2918	const Vector3 v2 = poly->mVertices[i + 1] - center;
2919
2920	volume += f * (DotProd(v0, CrossProd(v1, v2)));
2921	}
2922	}
2923
2924	return volume;
2925	}
2926
2927
2928	Vector3 BspNodeGeometry::CenterOfMass() const
2929	{
2930	int n = 0;
2931
2932	Vector3 center(0,0,0);
2933
2934	PolygonContainer::const_iterator pit, pit_end = mPolys.end();
2935
2936	for (pit = mPolys.begin(); pit != pit_end; ++ pit)
2937	{
2938	Polygon3 poly = pit;
2939
2940	VertexContainer::const_iterator vit, vit_end = poly->mVertices.end();
2941
2942	for(vit = poly->mVertices.begin(); vit != vit_end; ++ vit)
2943	{
2944	center += *vit;
2945	++ n;
2946	}
2947	}
2948
2949	return center / (float)n;
2950	}
2951
2952
2953	void BspNodeGeometry::AddToMesh(Mesh &mesh)
2954	{
2955	PolygonContainer::const_iterator it, it_end = mPolys.end();
2956
2957	for (it = mPolys.begin(); it != mPolys.end(); ++ it)
2958	{
2959	(*it)->AddToMesh(mesh);
2960	}
2961	}
2962
2963
2964	void BspNodeGeometry::SplitGeometry(BspNodeGeometry &front,
2965	BspNodeGeometry &back,
2966	const Plane3 &splitPlane,
2967	const AxisAlignedBox3 &box,
2968	const float epsilon) const
2969	{
2970	// get cross section of new polygon
2971	Polygon3 *planePoly = box.CrossSection(splitPlane);
2972
2973	// split polygon with all other polygons
2974	planePoly = SplitPolygon(planePoly, epsilon);
2975
2976	//-- new polygon splits all other polygons
2977	for (int i = 0; i < (int)mPolys.size(); ++ i)
2978	{
2979	/// don't use epsilon here to get exact split planes
2980	const int cf =
2981	mPolys[i]->ClassifyPlane(splitPlane, Limits::Small);
2982
2983	switch (cf)
2984	{
2985	case Polygon3::SPLIT:
2986	{
2987	Polygon3 *poly = new Polygon3(mPolys[i]->mVertices);
2988
2989	Polygon3 *frontPoly = new Polygon3();
2990	Polygon3 *backPoly = new Polygon3();
2991
2992	poly->Split(splitPlane,
2993	*frontPoly,
2994	*backPoly,
2995	epsilon);
2996
2997	DEL_PTR(poly);
2998
2999	if (frontPoly->Valid(epsilon))
3000	front.mPolys.push_back(frontPoly);
3001	else
3002	DEL_PTR(frontPoly);
3003
3004	if (backPoly->Valid(epsilon))
3005	back.mPolys.push_back(backPoly);
3006	else
3007	DEL_PTR(backPoly);
3008	}
3009
3010	break;
3011	case Polygon3::BACK_SIDE:
3012	back.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
3013	break;
3014	case Polygon3::FRONT_SIDE:
3015	front.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
3016	break;
3017	case Polygon3::COINCIDENT:
3018	//front.mPolys.push_back(CreateReversePolygon(mPolys[i]));
3019	back.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
3020	break;
3021	default:
3022	break;
3023	}
3024	}
3025
3026	//-- finally add the new polygon to the child node geometries
3027	if (planePoly)
3028	{
3029	// add polygon with normal pointing into positive half space to back cell
3030	back.mPolys.push_back(planePoly);
3031	// add polygon with reverse orientation to front cell
3032	front.mPolys.push_back(planePoly->CreateReversePolygon());
3033	}
3034	}
3035
3036
3037	Polygon3 BspNodeGeometry::SplitPolygon(Polygon3 planePoly,
3038	const float epsilon) const
3039	{
3040	if (!planePoly->Valid(epsilon))
3041	DEL_PTR(planePoly);
3042
3043	// polygon is split by all other planes
3044	for (int i = 0; (i < (int)mPolys.size()) && planePoly; ++ i)
3045	{
3046	Plane3 plane = mPolys[i]->GetSupportingPlane();
3047
3048	/// don't use epsilon here to get exact split planes
3049	const int cf =
3050	planePoly->ClassifyPlane(plane, Limits::Small);
3051
3052	// split new polygon with all previous planes
3053	switch (cf)
3054	{
3055	case Polygon3::SPLIT:
3056	{
3057	Polygon3 *frontPoly = new Polygon3();
3058	Polygon3 *backPoly = new Polygon3();
3059
3060	planePoly->Split(plane,
3061	*frontPoly,
3062	*backPoly,
3063	epsilon);
3064
3065	// don't need anymore
3066	DEL_PTR(planePoly);
3067	DEL_PTR(frontPoly);
3068
3069	// back polygon is belonging to geometry
3070	if (backPoly->Valid(epsilon))
3071	planePoly = backPoly;
3072	else
3073	DEL_PTR(backPoly);
3074	}
3075	break;
3076	case Polygon3::FRONT_SIDE:
3077	DEL_PTR(planePoly);
3078	break;
3079	// polygon is taken as it is
3080	case Polygon3::BACK_SIDE:
3081	case Polygon3::COINCIDENT:
3082	default:
3083	break;
3084	}
3085	}
3086
3087	return planePoly;
3088	}
3089
3090
3091	ViewCell *
3092	BspTree::GetViewCell(const Vector3 &point)
3093	{
3094	if (mRoot == NULL)
3095	return NULL;
3096
3097
3098	stack<BspNode *> nodeStack;
3099	nodeStack.push(mRoot);
3100
3101	ViewCell *viewcell = NULL;
3102
3103	while (!nodeStack.empty()) {
3104	BspNode *node = nodeStack.top();
3105	nodeStack.pop();
3106
3107	if (node->IsLeaf()) {
3108	viewcell = dynamic_cast<BspLeaf *>(node)->mViewCell;
3109	break;
3110	} else {
3111
3112	BspInterior interior = dynamic_cast<BspInterior >(node);
3113
3114	// random decision
3115	if (interior->GetPlane().Side(point) < 0)
3116	nodeStack.push(interior->GetBack());
3117	else
3118	nodeStack.push(interior->GetFront());
3119	}
3120	}
3121
3122	return viewcell;
3123	}
3124
3125
3126	void BspNodeGeometry::IncludeInBox(AxisAlignedBox3 &box)
3127	{
3128	Polygon3::IncludeInBox(mPolys, box);
3129	}
3130
3131
3132	bool BspTree::Export(ofstream &stream)
3133	{
3134	ExportNode(mRoot, stream);
3135
3136	return true;
3137	}
3138
3139
3140	void BspTree::ExportNode(BspNode *node, ofstream &stream)
3141	{
3142	if (node->IsLeaf())
3143	{
3144	BspLeaf leaf = dynamic_cast<BspLeaf >(node);
3145
3146	int id = -1;
3147	if (leaf->GetViewCell() != mOutOfBoundsCell)
3148	id = leaf->GetViewCell()->GetId();
3149
3150	stream << "<Leaf viewCellId=\"" << id << "\" />" << endl;
3151	}
3152	else
3153	{
3154	BspInterior interior = dynamic_cast<BspInterior >(node);
3155
3156	Plane3 plane = interior->GetPlane();
3157	stream << "<Interior plane=\"" << plane.mNormal.x << " "
3158	<< plane.mNormal.y << " " << plane.mNormal.z << " "
3159	<< plane.mD << "\">" << endl;
3160
3161	ExportNode(interior->GetBack(), stream);
3162	ExportNode(interior->GetFront(), stream);
3163
3164	stream << "</Interior>" << endl;
3165	}
3166	}

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