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source: GTP/trunk/Lib/Vis/Preprocessing/src/ViewCellBsp.cpp @ 667

Revision 667, 77.3 KB checked in by mattausch, 18 years ago (diff)
test version build script for testing. code is set uo for testing also

Line
1	#include "Plane3.h"
2	#include "ViewCellBsp.h"
3	#include "Mesh.h"
4	#include "common.h"
5	#include "ViewCell.h"
6	#include "Environment.h"
7	#include "Polygon3.h"
8	#include "Ray.h"
9	#include "AxisAlignedBox3.h"
10	#include "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
56	BspNode::BspNode(BspInterior *parent):
57	mParent(parent), mTreeValid(true)
58	{}
59
60
61	bool BspNode::IsRoot() const
62	{
63	return mParent == NULL;
64	}
65
66
67	BspInterior *BspNode::GetParent()
68	{
69	return mParent;
70	}
71
72
73	void BspNode::SetParent(BspInterior *parent)
74	{
75	mParent = parent;
76	}
77
78
79	bool BspNode::IsSibling(BspNode *n) const
80	{
81	return ((this != n) && mParent &&
82	(mParent->GetFront() == n) \|\| (mParent->GetBack() == n));
83	}
84
85
86	int BspNode::GetDepth() const
87	{
88	int depth = 0;
89	BspNode *p = mParent;
90
91	while (p)
92	{
93	p = p->mParent;
94	++ depth;
95	}
96
97	return depth;
98	}
99
100
101	bool BspNode::TreeValid() const
102	{
103	return mTreeValid;
104	}
105
106
107	void BspNode::SetTreeValid(const bool v)
108	{
109	mTreeValid = v;
110	}
111
112
113	/****************************************************************/
114	/* class BspInterior implementation */
115	/****************************************************************/
116
117
118	BspInterior::BspInterior(const Plane3 &plane):
119	mPlane(plane), mFront(NULL), mBack(NULL)
120	{}
121
122	BspInterior::~BspInterior()
123	{
124	DEL_PTR(mFront);
125	DEL_PTR(mBack);
126	}
127
128	bool BspInterior::IsLeaf() const
129	{
130	return false;
131	}
132
133	BspNode *BspInterior::GetBack()
134	{
135	return mBack;
136	}
137
138	BspNode *BspInterior::GetFront()
139	{
140	return mFront;
141	}
142
143	Plane3 BspInterior::GetPlane() const
144	{
145	return mPlane;
146	}
147
148	void BspInterior::ReplaceChildLink(BspNode oldChild, BspNode newChild)
149	{
150	if (mBack == oldChild)
151	mBack = newChild;
152	else
153	mFront = newChild;
154	}
155
156	void BspInterior::SetupChildLinks(BspNode b, BspNode f)
157	{
158	mBack = b;
159	mFront = f;
160	}
161
162	/****************************************************************/
163	/* class BspLeaf implementation */
164	/****************************************************************/
165
166
167	BspLeaf::BspLeaf(): mViewCell(NULL), mPvs(NULL)
168	{
169	}
170
171
172	BspLeaf::~BspLeaf()
173	{
174	DEL_PTR(mPvs);
175	}
176
177
178	BspLeaf::BspLeaf(ViewCell *viewCell):
179	mViewCell(viewCell)
180	{
181	}
182
183
184	BspLeaf::BspLeaf(BspInterior *parent):
185	BspNode(parent), mViewCell(NULL), mPvs(NULL)
186	{}
187
188
189
190	BspLeaf::BspLeaf(BspInterior parent, ViewCell viewCell):
191	BspNode(parent), mViewCell(viewCell), mPvs(NULL)
192	{
193	}
194
195	ViewCell *BspLeaf::GetViewCell() const
196	{
197	return mViewCell;
198	}
199
200	void BspLeaf::SetViewCell(ViewCell *viewCell)
201	{
202	mViewCell = viewCell;
203	}
204
205
206	bool BspLeaf::IsLeaf() const
207	{
208	return true;
209	}
210
211
212	/*********************************************************************/
213	/* class BspTree implementation */
214	/*********************************************************************/
215
216	BspTree::BspTree():
217	mRoot(NULL),
218	mUseAreaForPvs(false),
219	mGenerateViewCells(true),
220	mTimeStamp(1)
221	{
222	Randomize(); // initialise random generator for heuristics
223
224	mOutOfBoundsCell = GetOrCreateOutOfBoundsCell();
225
226	//-- termination criteria for autopartition
227	environment->GetIntValue("BspTree.Termination.maxDepth", mTermMaxDepth);
228	environment->GetIntValue("BspTree.Termination.minPvs", mTermMinPvs);
229	environment->GetIntValue("BspTree.Termination.minPolygons", mTermMinPolys);
230	environment->GetIntValue("BspTree.Termination.minRays", mTermMinRays);
231	environment->GetFloatValue("BspTree.Termination.minProbability", mTermMinProbability);
232	environment->GetFloatValue("BspTree.Termination.maxRayContribution", mTermMaxRayContribution);
233	environment->GetFloatValue("BspTree.Termination.minAccRayLenght", mTermMinAccRayLength);
234
235	//-- factors for bsp tree split plane heuristics
236	environment->GetFloatValue("BspTree.Factor.verticalSplits", mVerticalSplitsFactor);
237	environment->GetFloatValue("BspTree.Factor.largestPolyArea", mLargestPolyAreaFactor);
238	environment->GetFloatValue("BspTree.Factor.blockedRays", mBlockedRaysFactor);
239	environment->GetFloatValue("BspTree.Factor.leastRaySplits", mLeastRaySplitsFactor);
240	environment->GetFloatValue("BspTree.Factor.balancedRays", mBalancedRaysFactor);
241	environment->GetFloatValue("BspTree.Factor.pvs", mPvsFactor);
242	environment->GetFloatValue("BspTree.Factor.leastSplits" , mLeastSplitsFactor);
243	environment->GetFloatValue("BspTree.Factor.balancedPolys", mBalancedPolysFactor);
244	environment->GetFloatValue("BspTree.Factor.balancedViewCells", mBalancedViewCellsFactor);
245	environment->GetFloatValue("BspTree.Termination.ct_div_ci", mCtDivCi);
246
247	//-- termination criteria for axis aligned split
248	environment->GetFloatValue("BspTree.Termination.AxisAligned.ct_div_ci", mAxisAlignedCtDivCi);
249	environment->GetFloatValue("BspTree.Termination.maxCostRatio", mMaxCostRatio);
250	environment->GetIntValue("BspTree.Termination.AxisAligned.minPolys",
251	mTermMinPolysForAxisAligned);
252	environment->GetIntValue("BspTree.Termination.AxisAligned.minRays",
253	mTermMinRaysForAxisAligned);
254	environment->GetIntValue("BspTree.Termination.AxisAligned.minObjects",
255	mTermMinObjectsForAxisAligned);
256	//-- partition criteria
257	environment->GetIntValue("BspTree.maxPolyCandidates", mMaxPolyCandidates);
258	environment->GetIntValue("BspTree.maxRayCandidates", mMaxRayCandidates);
259	environment->GetIntValue("BspTree.splitPlaneStrategy", mSplitPlaneStrategy);
260	environment->GetFloatValue("BspTree.AxisAligned.splitBorder", mSplitBorder);
261	environment->GetIntValue("BspTree.maxTests", mMaxTests);
262	environment->GetIntValue("BspTree.Termination.maxViewCells", mMaxViewCells);
263
264	environment->GetFloatValue("BspTree.Construction.epsilon", mEpsilon);
265
266	char subdivisionStatsLog[100];
267	environment->GetStringValue("BspTree.subdivisionStats", subdivisionStatsLog);
268	mSubdivisionStats.open(subdivisionStatsLog);
269
270	Debug << "BSP max depth: " << mTermMaxDepth << endl;
271	Debug << "BSP min PVS: " << mTermMinPvs << endl;
272	Debug << "BSP min probability: " << mTermMinProbability << endl;
273	Debug << "BSP max polys: " << mTermMinPolys << endl;
274	Debug << "BSP max rays: " << mTermMinRays << endl;
275	Debug << "BSP max polygon candidates: " << mMaxPolyCandidates << endl;
276	Debug << "BSP max plane candidates: " << mMaxRayCandidates << endl;
277
278	Debug << "Split plane strategy: ";
279	if (mSplitPlaneStrategy & RANDOM_POLYGON)
280	Debug << "random polygon ";
281	if (mSplitPlaneStrategy & AXIS_ALIGNED)
282	Debug << "axis aligned ";
283	if (mSplitPlaneStrategy & LEAST_SPLITS)
284	Debug << "least splits ";
285	if (mSplitPlaneStrategy & BALANCED_POLYS)
286	Debug << "balanced polygons ";
287	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
288	Debug << "balanced view cells ";
289	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
290	Debug << "largest polygon area ";
291	if (mSplitPlaneStrategy & VERTICAL_AXIS)
292	Debug << "vertical axis ";
293	if (mSplitPlaneStrategy & BLOCKED_RAYS)
294	Debug << "blocked rays ";
295	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
296	Debug << "least ray splits ";
297	if (mSplitPlaneStrategy & BALANCED_RAYS)
298	Debug << "balanced rays ";
299	if (mSplitPlaneStrategy & PVS)
300	Debug << "pvs";
301
302	Debug << endl;
303	}
304
305
306	const BspTreeStatistics &BspTree::GetStatistics() const
307	{
308	return mStat;
309	}
310
311
312	int BspTree::SplitPolygons(const Plane3 &plane,
313	PolygonContainer &polys,
314	PolygonContainer &frontPolys,
315	PolygonContainer &backPolys,
316	PolygonContainer &coincident) const
317	{
318	int splits = 0;
319
320	#ifdef _Debug
321	Debug << "splitting polygons of node " << this << " with plane " << mPlane << endl;
322	#endif
323
324	PolygonContainer::const_iterator it, it_end = polys.end();
325
326	for (it = polys.begin(); it != polys.end(); ++ it)
327	{
328	Polygon3 poly = it;
329
330	//-- classify polygon
331	const int cf = poly->ClassifyPlane(plane, mEpsilon);
332
333	switch (cf)
334	{
335	case Polygon3::COINCIDENT:
336	coincident.push_back(poly);
337	break;
338	case Polygon3::FRONT_SIDE:
339	frontPolys.push_back(poly);
340	break;
341	case Polygon3::BACK_SIDE:
342	backPolys.push_back(poly);
343	break;
344	case Polygon3::SPLIT:
345	{
346	Polygon3 *front_piece = new Polygon3(poly->mParent);
347	Polygon3 *back_piece = new Polygon3(poly->mParent);
348
349	//-- split polygon into front and back part
350	poly->Split(plane,
351	*front_piece,
352	*back_piece,
353	mEpsilon);
354
355	++ splits; // increase number of splits
356
357	//-- inherit rays from parent polygon for blocked ray criterium
358	poly->InheritRays(front_piece, back_piece);
359
360	// check if polygons still valid
361	if (front_piece->Valid(mEpsilon))
362	frontPolys.push_back(front_piece);
363	else
364	DEL_PTR(front_piece);
365
366	if (back_piece->Valid(mEpsilon))
367	backPolys.push_back(back_piece);
368	else
369	DEL_PTR(back_piece);
370
371	#ifdef _DEBUG
372	Debug << "split " << poly << endl << front_piece << endl << *back_piece << endl;
373	#endif
374	DEL_PTR(poly);
375	}
376	break;
377	default:
378	Debug << "SHOULD NEVER COME HERE\n";
379	break;
380	}
381	}
382
383	return splits;
384	}
385
386
387	void BspTreeStatistics::Print(ostream &app) const
388	{
389	app << "===== BspTree statistics ===============\n";
390
391	app << setprecision(4);
392
393	app << "#N_CTIME ( Construction time [s] )\n" << Time() << " \n";
394
395	app << "#N_NODES ( Number of nodes )\n" << nodes << "\n";
396
397	app << "#N_INTERIORS ( Number of interior nodes )\n" << Interior() << "\n";
398
399	app << "#N_LEAVES ( Number of leaves )\n" << Leaves() << "\n";
400
401	app << "#N_POLYSPLITS ( Number of polygon splits )\n" << polySplits << "\n";
402
403	app << "#AXIS_ALIGNED_SPLITS (number of axis aligned splits)\n" << splits[0] + splits[1] + splits[2] << endl;
404
405	app << "#N_SPLITS ( Number of splits in axes x y z)\n";
406
407	for (int i = 0; i < 3; ++ i)
408	app << splits[i] << " ";
409	app << endl;
410
411	app << "#N_PMAXDEPTHLEAVES ( Percentage of leaves at maximum depth )\n"
412	<< maxDepthNodes * 100 / (double)Leaves() << endl;
413
414	app << "#N_PMINPVSLEAVES ( Percentage of leaves with mininimal PVS )\n"
415	<< minPvsNodes * 100 / (double)Leaves() << endl;
416
417	app << "#N_PMINRAYSLEAVES ( Percentage of leaves with minimal number of rays)\n"
418	<< minRaysNodes * 100 / (double)Leaves() << endl;
419
420	app << "#N_MAXCOSTNODES ( Percentage of leaves with terminated because of max cost ratio )\n"
421	<< maxCostNodes * 100 / (double)Leaves() << endl;
422
423	app << "#N_PMINPROBABILITYLEAVES ( Percentage of leaves with mininum probability )\n"
424	<< minProbabilityNodes * 100 / (double)Leaves() << endl;
425
426	app << "#N_PMAXRAYCONTRIBLEAVES ( Percentage of leaves with maximal ray contribution )\n"
427	<< maxRayContribNodes * 100 / (double)Leaves() << endl;
428
429	app << "#N_PMAXDEPTH ( Maximal reached depth )\n" << maxDepth << endl;
430
431	app << "#N_PMINDEPTH ( Minimal reached depth )\n" << minDepth << endl;
432
433	app << "#AVGDEPTH ( average depth )\n" << AvgDepth() << endl;
434
435	app << "#N_INPUTPOLYGONS (number of input polygons )\n" << polys << endl;
436
437	app << "#N_INVALIDLEAVES (number of invalid leaves )\n" << invalidLeaves << endl;
438
439	app << "#N_RAYS (number of rays / leaf)\n" << AvgRays() << endl;
440	//app << "#N_PVS: " << pvs << endl;
441
442	app << "#N_ROUTPUT_INPUT_POLYGONS ( ratio polygons after subdivision / input polygons )\n" <<
443	(polys + polySplits) / (double)polys << endl;
444
445	app << "===== END OF BspTree statistics ==========\n";
446	}
447
448
449	BspTree::~BspTree()
450	{
451	DEL_PTR(mRoot);
452
453	// TODO must be deleted if used!!
454	//if (mGenerateViewCells) DEL_PTR(mOutOfBoundsCell);
455	}
456
457	BspViewCell *BspTree::GetOutOfBoundsCell()
458	{
459	return mOutOfBoundsCell;
460	}
461
462
463	BspNode *BspTree::GetRoot() const
464	{
465	return mRoot;
466	}
467
468	BspViewCell *BspTree::GetOrCreateOutOfBoundsCell()
469	{
470	if (!mOutOfBoundsCell)
471	{
472	mOutOfBoundsCell = new BspViewCell();
473	mOutOfBoundsCell->SetId(-1);
474	mOutOfBoundsCell->SetValid(false);
475	}
476
477	return mOutOfBoundsCell;
478	}
479
480
481	void BspTree::InsertViewCell(ViewCell *viewCell)
482	{
483	PolygonContainer *polys = new PolygonContainer();
484
485	// don't generate new view cell, insert this one
486	mGenerateViewCells = false;
487	// extract polygons that guide the split process
488	mStat.polys += AddMeshToPolygons(viewCell->GetMesh(), *polys, viewCell);
489	mBox.Include(viewCell->GetBox()); // add to BSP aabb
490
491	InsertPolygons(polys);
492	}
493
494
495	void BspTree::InsertPolygons(PolygonContainer *polys)
496	{
497	BspTraversalStack tStack;
498
499	// traverse existing tree or create new tree
500	if (!mRoot)
501	mRoot = new BspLeaf();
502
503	tStack.push(BspTraversalData(mRoot,
504	polys,
505	0,
506	mOutOfBoundsCell,
507	new BoundedRayContainer(),
508	0,
509	mUseAreaForPvs ? mBox.SurfaceArea() : mBox.GetVolume(),
510	new BspNodeGeometry()));
511
512	while (!tStack.empty())
513	{
514	// filter polygons donw the tree
515	BspTraversalData tData = tStack.top();
516	tStack.pop();
517
518	if (!tData.mNode->IsLeaf())
519	{
520	BspInterior interior = dynamic_cast<BspInterior >(tData.mNode);
521
522	//-- filter view cell polygons down the tree until a leaf is reached
523	if (!tData.mPolygons->empty())
524	{
525	PolygonContainer *frontPolys = new PolygonContainer();
526	PolygonContainer *backPolys = new PolygonContainer();
527	PolygonContainer coincident;
528
529	int splits = 0;
530
531	// split viewcell polygons with respect to split plane
532	splits += SplitPolygons(interior->GetPlane(),
533	*tData.mPolygons,
534	*frontPolys,
535	*backPolys,
536	coincident);
537
538	// extract view cells associated with the split polygons
539	ViewCell *frontViewCell = GetOrCreateOutOfBoundsCell();
540	ViewCell *backViewCell = GetOrCreateOutOfBoundsCell();
541
542	BspTraversalData frontData(interior->GetFront(),
543	frontPolys,
544	tData.mDepth + 1,
545	mOutOfBoundsCell,
546	tData.mRays,
547	tData.mPvs,
548	mUseAreaForPvs ? mBox.SurfaceArea() : mBox.GetVolume(),
549	new BspNodeGeometry());
550
551	BspTraversalData backData(interior->GetBack(),
552	backPolys,
553	tData.mDepth + 1,
554	mOutOfBoundsCell,
555	tData.mRays,
556	tData.mPvs,
557	mUseAreaForPvs ? mBox.SurfaceArea() : mBox.GetVolume(),
558	new BspNodeGeometry());
559
560	if (!mGenerateViewCells)
561	{
562	ExtractViewCells(frontData,
563	backData,
564	coincident,
565	interior->mPlane);
566	}
567
568	// don't need coincident polygons anymore
569	CLEAR_CONTAINER(coincident);
570
571	mStat.polySplits += splits;
572
573	// push the children on the stack
574	tStack.push(frontData);
575	tStack.push(backData);
576	}
577
578	// cleanup
579	DEL_PTR(tData.mPolygons);
580	DEL_PTR(tData.mRays);
581	}
582	else
583	{
584	// reached leaf => subdivide current viewcell
585	BspNode *subRoot = Subdivide(tStack, tData);
586	}
587	}
588	}
589
590	int BspTree::AddMeshToPolygons(Mesh *mesh,
591	PolygonContainer &polys,
592	MeshInstance *parent)
593	{
594	FaceContainer::const_iterator fi;
595
596	// copy the face data to polygons
597	for (fi = mesh->mFaces.begin(); fi != mesh->mFaces.end(); ++ fi)
598	{
599	Polygon3 poly = new Polygon3((fi), mesh);
600
601	if (poly->Valid(mEpsilon))
602	{
603	poly->mParent = parent; // set parent intersectable
604	polys.push_back(poly);
605	}
606	else
607	DEL_PTR(poly);
608	}
609	return (int)mesh->mFaces.size();
610	}
611
612
613	int BspTree::AddToPolygonSoup(const ViewCellContainer &viewCells,
614	PolygonContainer &polys,
615	int maxObjects)
616	{
617	int limit = (maxObjects > 0) ?
618	Min((int)viewCells.size(), maxObjects) : (int)viewCells.size();
619
620	int polysSize = 0;
621
622	for (int i = 0; i < limit; ++ i)
623	{
624	if (viewCells[i]->GetMesh()) // copy the mesh data to polygons
625	{
626	mBox.Include(viewCells[i]->GetBox()); // add to BSP tree aabb
627	polysSize += AddMeshToPolygons(viewCells[i]->GetMesh(), polys, viewCells[i]);
628	}
629	}
630
631	return polysSize;
632	}
633
634
635	int BspTree::AddToPolygonSoup(const ObjectContainer &objects,
636	PolygonContainer &polys,
637	int maxObjects,
638	bool addToBbox)
639	{
640	int limit = (maxObjects > 0) ?
641	Min((int)objects.size(), maxObjects) : (int)objects.size();
642
643	for (int i = 0; i < limit; ++i)
644	{
645	Intersectable object = objects[i];//it;
646	Mesh *mesh = NULL;
647
648	switch (object->Type()) // extract the meshes
649	{
650	case Intersectable::MESH_INSTANCE:
651	mesh = dynamic_cast<MeshInstance *>(object)->GetMesh();
652	break;
653	case Intersectable::VIEW_CELL:
654	mesh = dynamic_cast<ViewCell *>(object)->GetMesh();
655	break;
656	// TODO: handle transformed mesh instances
657	default:
658	Debug << "intersectable type not supported" << endl;
659	break;
660	}
661
662	if (mesh) // copy the mesh data to polygons
663	{
664	if (addToBbox)
665	{
666	mBox.Include(object->GetBox()); // add to BSP tree aabb
667	}
668
669	AddMeshToPolygons(mesh, polys, mOutOfBoundsCell);
670	}
671	}
672
673	return (int)polys.size();
674	}
675
676
677	void BspTree::Construct(const ViewCellContainer &viewCells)
678	{
679	mStat.nodes = 1;
680	mBox.Initialize(); // initialise bsp tree bounding box
681
682	// copy view cell meshes into one big polygon soup
683	PolygonContainer *polys = new PolygonContainer();
684	mStat.polys = AddToPolygonSoup(viewCells, *polys);
685
686	// view cells are given
687	mGenerateViewCells = false;
688	// construct tree from the view cell polygons
689	Construct(polys, new BoundedRayContainer());
690	}
691
692
693	void BspTree::Construct(const ObjectContainer &objects)
694	{
695	mStat.nodes = 1;
696	mBox.Initialize(); // initialise bsp tree bounding box
697
698	PolygonContainer *polys = new PolygonContainer();
699
700	mGenerateViewCells = true;
701	// copy mesh instance polygons into one big polygon soup
702	mStat.polys = AddToPolygonSoup(objects, *polys);
703
704	// construct tree from polygon soup
705	Construct(polys, new BoundedRayContainer());
706	}
707
708
709	void BspTree::PreprocessPolygons(PolygonContainer &polys)
710	{
711	// preprocess: throw out polygons coincident to the view space box (not needed)
712	PolygonContainer boxPolys;
713	mBox.ExtractPolys(boxPolys);
714	vector<Plane3> boxPlanes;
715
716	PolygonContainer::iterator pit, pit_end = boxPolys.end();
717
718	// extract planes of box
719	// TODO: can be done more elegantly than first extracting polygons
720	// and take their planes
721	for (pit = boxPolys.begin(); pit != pit_end; ++ pit)
722	{
723	boxPlanes.push_back((*pit)->GetSupportingPlane());
724	}
725
726	pit_end = polys.end();
727
728	for (pit = polys.begin(); pit != pit_end; ++ pit)
729	{
730	vector<Plane3>::const_iterator bit, bit_end = boxPlanes.end();
731
732	for (bit = boxPlanes.begin(); (bit != bit_end) && (*pit); ++ bit)
733	{
734	const int cf = (pit)->ClassifyPlane(bit, mEpsilon);
735
736	if (cf == Polygon3::COINCIDENT)
737	{
738	DEL_PTR(*pit);
739	//Debug << "coincident!!" << endl;
740	}
741	}
742	}
743
744	// remove deleted entries
745	for (int i = 0; i < (int)polys.size(); ++ i)
746	{
747	while (!polys[i] && (i < (int)polys.size()))
748	{
749	swap(polys[i], polys.back());
750	polys.pop_back();
751	}
752	}
753	}
754
755
756
757	void BspTree::Construct(const RayContainer &sampleRays,
758	AxisAlignedBox3 *forcedBoundingBox)
759	{
760	mStat.nodes = 1;
761	mBox.Initialize(); // initialise BSP tree bounding box
762
763	if (forcedBoundingBox)
764	mBox = *forcedBoundingBox;
765
766	PolygonContainer *polys = new PolygonContainer();
767	BoundedRayContainer *rays = new BoundedRayContainer();
768
769	RayContainer::const_iterator rit, rit_end = sampleRays.end();
770
771	// generate view cells
772	mGenerateViewCells = true;
773
774	long startTime = GetTime();
775
776	Debug << "** Extracting polygons from rays **\n";
777
778	std::map<Face , Polygon3 > facePolyMap;
779
780	//-- extract polygons intersected by the rays
781	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
782	{
783	Ray ray = rit;
784
785	// get ray-face intersection. Store polygon representing the rays together
786	// with rays intersecting the face.
787	if (!ray->intersections.empty())
788	{
789	MeshInstance obj = dynamic_cast<MeshInstance >(ray->intersections[0].mObject);
790	Face *face = obj->GetMesh()->mFaces[ray->intersections[0].mFace];
791
792	std::map<Face , Polygon3 >::iterator it = facePolyMap.find(face);
793
794	if (it != facePolyMap.end())
795	{
796	//store rays if needed for heuristics
797	if (mSplitPlaneStrategy & BLOCKED_RAYS)
798	(*it).second->mPiercingRays.push_back(ray);
799	}
800	else
801	{ //store rays if needed for heuristics
802	Polygon3 *poly = new Polygon3(face, obj->GetMesh());
803	poly->mParent = obj;
804	polys->push_back(poly);
805
806	if (mSplitPlaneStrategy & BLOCKED_RAYS)
807	poly->mPiercingRays.push_back(ray);
808
809	facePolyMap[face] = poly;
810	}
811	}
812	}
813
814	facePolyMap.clear();
815
816	// compute bounding box
817	if (!forcedBoundingBox)
818	Polygon3::IncludeInBox(*polys, mBox);
819
820	//-- store rays
821	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
822	{
823	Ray ray = rit;
824	ray->SetId(-1); // reset id
825
826	float minT, maxT;
827	if (mBox.GetRaySegment(*ray, minT, maxT))
828	rays->push_back(new BoundedRay(ray, minT, maxT));
829	}
830
831	// throw out bad polygons
832	PreprocessPolygons(*polys);
833
834	mStat.polys = (int)polys->size();
835
836	Debug << "** Finished polygon extraction **" << endl;
837	Debug << (int)polys->size() << " polys extracted from " << (int)sampleRays.size() << " rays" << endl;
838	Debug << "extraction time: " << TimeDiff(startTime, GetTime())*1e-3 << "s" << endl;
839
840	Construct(polys, rays);
841	}
842
843
844	void BspTree::Construct(const ObjectContainer &objects,
845	const RayContainer &sampleRays,
846	AxisAlignedBox3 *forcedBoundingBox)
847	{
848	mStat.nodes = 1;
849	mBox.Initialize(); // initialise BSP tree bounding box
850
851	if (forcedBoundingBox)
852	mBox = *forcedBoundingBox;
853
854	BoundedRayContainer *rays = new BoundedRayContainer();
855	PolygonContainer *polys = new PolygonContainer();
856
857	mGenerateViewCells = true;
858
859	// copy mesh instance polygons into one big polygon soup
860	mStat.polys = AddToPolygonSoup(objects, *polys, 0, !forcedBoundingBox);
861
862
863	RayContainer::const_iterator rit, rit_end = sampleRays.end();
864
865	//-- store rays
866	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
867	{
868	Ray ray = rit;
869	ray->SetId(-1); // reset id
870
871	float minT, maxT;
872	if (mBox.GetRaySegment(*ray, minT, maxT))
873	rays->push_back(new BoundedRay(ray, minT, maxT));
874	}
875
876	PreprocessPolygons(*polys);
877	Debug << "tree has " << (int)polys->size() << " polys, " << (int)sampleRays.size() << " rays" << endl;
878	Construct(polys, rays);
879	}
880
881
882	void BspTree::Construct(PolygonContainer polys, BoundedRayContainer rays)
883	{
884	BspTraversalStack tStack;
885
886	mRoot = new BspLeaf();
887
888	// constrruct root node geometry
889	BspNodeGeometry *geom = new BspNodeGeometry();
890	ConstructGeometry(mRoot, *geom);
891
892	BspTraversalData tData(mRoot,
893	polys,
894	0,
895	GetOrCreateOutOfBoundsCell(),
896	rays,
897	ComputePvsSize(*rays),
898	mUseAreaForPvs ? geom->GetArea() : geom->GetVolume(),
899	geom);
900
901	mTotalCost = tData.mPvs * tData.mProbability / mBox.GetVolume();
902	mTotalPvsSize = tData.mPvs;
903
904	mSubdivisionStats
905	<< "#ViewCells\n1\n" << endl
906	<< "#RenderCostDecrease\n0\n" << endl
907	<< "#TotalRenderCost\n" << mTotalCost << endl
908	<< "#AvgRenderCost\n" << mTotalPvsSize << endl;
909
910	tStack.push(tData);
911
912	// used for intermediate time measurements and progress
913	long interTime = GetTime();
914	int nleaves = 500;
915
916	mStat.Start();
917	cout << "Constructing bsp tree ...\n";
918	long startTime = GetTime();
919	while (!tStack.empty())
920	{
921	tData = tStack.top();
922
923	tStack.pop();
924
925	// subdivide leaf node
926	BspNode *r = Subdivide(tStack, tData);
927
928	if (r == mRoot)
929	Debug << "BSP tree construction time spent at root: "
930	<< TimeDiff(startTime, GetTime())*1e-3 << " secs" << endl;
931
932	if (mStat.Leaves() >= nleaves)
933	{
934	nleaves += 500;
935
936	cout << "leaves=" << mStat.Leaves() << endl;
937	Debug << "needed "
938	<< TimeDiff(interTime, GetTime())*1e-3
939	<< " secs to create 500 leaves" << endl;
940	interTime = GetTime();
941	}
942	}
943
944	cout << "finished\n";
945
946	mStat.Stop();
947	}
948
949
950	bool BspTree::TerminationCriteriaMet(const BspTraversalData &data) const
951	{
952	return
953	(((int)data.mPolygons->size() <= mTermMinPolys) \|\|
954	((int)data.mRays->size() <= mTermMinRays) \|\|
955	(data.mPvs <= mTermMinPvs) \|\|
956	(data.mProbability <= mTermMinProbability) \|\|
957	(data.mDepth >= mTermMaxDepth) \|\|
958	(mStat.Leaves() >= mMaxViewCells) \|\|
959	(data.GetAvgRayContribution() > mTermMaxRayContribution));
960	}
961
962
963	BspNode *BspTree::Subdivide(BspTraversalStack &tStack, BspTraversalData &tData)
964	{
965	//-- terminate traversal
966	if (TerminationCriteriaMet(tData))
967	{
968	BspLeaf leaf = dynamic_cast<BspLeaf >(tData.mNode);
969
970	BspViewCell *viewCell;
971
972	// generate new view cell for each leaf
973	if (mGenerateViewCells)
974	viewCell = new BspViewCell();
975	else
976	// add view cell to leaf
977	viewCell = dynamic_cast<BspViewCell *>(tData.mViewCell);
978
979	leaf->SetViewCell(viewCell);
980	viewCell->mLeaf = leaf;
981
982	if (mUseAreaForPvs)
983	viewCell->SetArea(tData.mProbability);
984	else
985	viewCell->SetVolume(tData.mProbability);
986
987	//-- add pvs
988	if (viewCell != mOutOfBoundsCell)
989	{
990	int conSamp = 0, sampCon = 0;
991	AddToPvs(leaf, *tData.mRays, conSamp, sampCon);
992
993	mStat.contributingSamples += conSamp;
994	mStat.sampleContributions += sampCon;
995	}
996
997	EvaluateLeafStats(tData);
998
999	//-- clean up
1000
1001	// discard polygons
1002	CLEAR_CONTAINER(*tData.mPolygons);
1003	// discard rays
1004	CLEAR_CONTAINER(*tData.mRays);
1005
1006	DEL_PTR(tData.mPolygons);
1007	DEL_PTR(tData.mRays);
1008	DEL_PTR(tData.mGeometry);
1009
1010	return leaf;
1011	}
1012
1013	//-- continue subdivision
1014	PolygonContainer coincident;
1015
1016	BspTraversalData tFrontData(NULL, new PolygonContainer(), tData.mDepth + 1, mOutOfBoundsCell,
1017	new BoundedRayContainer(), 0, 0, new BspNodeGeometry());
1018	BspTraversalData tBackData(NULL, new PolygonContainer(), tData.mDepth + 1, mOutOfBoundsCell,
1019	new BoundedRayContainer(), 0, 0, new BspNodeGeometry());
1020
1021
1022	// create new interior node and two leaf nodes
1023	BspInterior *interior =
1024	SubdivideNode(tData, tFrontData, tBackData, coincident);
1025
1026
1027	if (1)
1028	{
1029	int pvsData = tData.mPvs;
1030
1031	float cData = (float)pvsData * tData.mProbability;
1032	float cFront = (float)tFrontData.mPvs * tFrontData.mProbability;
1033	float cBack = (float)tBackData.mPvs * tBackData.mProbability;
1034
1035	float costDecr = (cFront + cBack - cData) / mBox.GetVolume();
1036
1037	mTotalCost += costDecr;
1038	mTotalPvsSize += tFrontData.mPvs + tBackData.mPvs - pvsData;
1039
1040	mSubdivisionStats
1041	<< "#ViewCells\n" << mStat.Leaves() << endl
1042	<< "#RenderCostDecrease\n" << -costDecr << endl
1043	<< "#TotalRenderCost\n" << mTotalCost << endl
1044	<< "#AvgRenderCost\n" << mTotalPvsSize / mStat.Leaves() << endl;
1045	}
1046
1047	// extract view cells from coincident polygons according to plane normal
1048	// only if front or back polygons are empty
1049	if (!mGenerateViewCells)
1050	{
1051	ExtractViewCells(tFrontData,
1052	tBackData,
1053	coincident,
1054	interior->mPlane);
1055	}
1056
1057	// don't need coincident polygons anymory
1058	CLEAR_CONTAINER(coincident);
1059
1060	// push the children on the stack
1061	tStack.push(tFrontData);
1062	tStack.push(tBackData);
1063
1064	// cleanup
1065	DEL_PTR(tData.mNode);
1066
1067	DEL_PTR(tData.mPolygons);
1068	DEL_PTR(tData.mRays);
1069	DEL_PTR(tData.mGeometry);
1070
1071	return interior;
1072	}
1073
1074
1075	void BspTree::ExtractViewCells(BspTraversalData &frontData,
1076	BspTraversalData &backData,
1077	const PolygonContainer &coincident,
1078	const Plane3 &splitPlane) const
1079	{
1080	// if not empty, tree is further subdivided => don't have to find view cell
1081	bool foundFront = !frontData.mPolygons->empty();
1082	bool foundBack = !frontData.mPolygons->empty();
1083
1084	PolygonContainer::const_iterator it =
1085	coincident.begin(), it_end = coincident.end();
1086
1087	//-- find first view cells in front and back leafs
1088	for (; !(foundFront && foundBack) && (it != it_end); ++ it)
1089	{
1090	if (DotProd((*it)->GetNormal(), splitPlane.mNormal) > 0)
1091	{
1092	backData.mViewCell = dynamic_cast<ViewCell >((it)->mParent);
1093	foundBack = true;
1094	}
1095	else
1096	{
1097	frontData.mViewCell = dynamic_cast<ViewCell >((it)->mParent);
1098	foundFront = true;
1099	}
1100	}
1101	}
1102
1103
1104	BspInterior *BspTree::SubdivideNode(BspTraversalData &tData,
1105	BspTraversalData &frontData,
1106	BspTraversalData &backData,
1107	PolygonContainer &coincident)
1108	{
1109	mStat.nodes += 2;
1110
1111	BspLeaf leaf = dynamic_cast<BspLeaf >(tData.mNode);
1112
1113
1114
1115	// select subdivision plane
1116	BspInterior *interior =
1117	new BspInterior(SelectPlane(leaf, tData));
1118
1119
1120	#ifdef _DEBUG
1121	Debug << interior << endl;
1122	#endif
1123
1124
1125	// subdivide rays into front and back rays
1126	SplitRays(interior->mPlane, tData.mRays, frontData.mRays, *backData.mRays);
1127
1128
1129
1130	// subdivide polygons with plane
1131	mStat.polySplits += SplitPolygons(interior->GetPlane(),
1132	*tData.mPolygons,
1133	*frontData.mPolygons,
1134	*backData.mPolygons,
1135	coincident);
1136
1137
1138
1139	// compute pvs
1140	frontData.mPvs = ComputePvsSize(*frontData.mRays);
1141	backData.mPvs = ComputePvsSize(*backData.mRays);
1142
1143	// split geometry and compute area
1144	if (1)
1145	{
1146	tData.mGeometry->SplitGeometry(*frontData.mGeometry,
1147	*backData.mGeometry,
1148	interior->mPlane,
1149	mBox,
1150	//0.000000000001);
1151	mEpsilon);
1152
1153
1154	if (mUseAreaForPvs)
1155	{
1156	frontData.mProbability = frontData.mGeometry->GetArea();
1157	backData.mProbability = backData.mGeometry->GetArea();
1158	}
1159	else
1160	{
1161	frontData.mProbability = frontData.mGeometry->GetVolume();
1162	backData.mProbability = tData.mProbability - frontData.mProbability;
1163	}
1164	}
1165
1166	//-- create front and back leaf
1167
1168	BspInterior *parent = leaf->GetParent();
1169
1170	// replace a link from node's parent
1171	if (!leaf->IsRoot())
1172	{
1173	parent->ReplaceChildLink(leaf, interior);
1174	interior->SetParent(parent);
1175	}
1176	else // new root
1177	{
1178	mRoot = interior;
1179	}
1180
1181	// and setup child links
1182	interior->SetupChildLinks(new BspLeaf(interior), new BspLeaf(interior));
1183
1184	frontData.mNode = interior->GetFront();
1185	backData.mNode = interior->GetBack();
1186
1187	interior->mTimeStamp = mTimeStamp ++;
1188
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	const float thresh = 1 ? 1e-6f : 0.0f;
2090
2091	while (1)
2092	{
2093	if (!node->IsLeaf())
2094	{
2095	BspInterior in = dynamic_cast<BspInterior >(node);
2096
2097	Plane3 splitPlane = in->GetPlane();
2098
2099	const int entSide = splitPlane.Side(entp, thresh);
2100	const int extSide = splitPlane.Side(extp, thresh);
2101
2102	if (entSide < 0)
2103	{
2104	node = in->GetBack();
2105
2106	if(extSide <= 0) // plane does not split ray => no far child
2107	continue;
2108
2109	farChild = in->GetFront(); // plane splits ray
2110
2111	}
2112	else if (entSide > 0)
2113	{
2114	node = in->GetFront();
2115
2116	if (extSide >= 0) // plane does not split ray => no far child
2117	continue;
2118
2119	farChild = in->GetBack(); // plane splits ray
2120	}
2121	else // ray and plane are coincident
2122	{
2123	// NOTE: what to do if ray is coincident with plane?
2124	if (extSide < 0)
2125	node = in->GetBack();
2126	else
2127	node = in->GetFront();
2128
2129	continue; // no far child
2130	}
2131
2132	// push data for far child
2133	tStack.push(BspRayTraversalData(farChild, extp, maxt));
2134
2135	// find intersection of ray segment with plane
2136	float t;
2137	extp = splitPlane.FindIntersection(origin, extp, &t);
2138	maxt *= t;
2139	}
2140	else
2141	{
2142	// reached leaf => intersection with view cell
2143	BspLeaf leaf = dynamic_cast<BspLeaf >(node);
2144
2145	if (!leaf->mViewCell->Mailed())
2146	{
2147	viewcells.push_back(leaf->mViewCell);
2148	leaf->mViewCell->Mail();
2149	hits++;
2150	}
2151
2152	//-- fetch the next far child from the stack
2153	if (tStack.empty())
2154	break;
2155
2156	entp = extp;
2157	mint = maxt; // NOTE: need this?
2158
2159	BspRayTraversalData &s = tStack.top();
2160
2161	node = s.mNode;
2162	extp = s.mExitPoint;
2163	maxt = s.mMaxT;
2164
2165	tStack.pop();
2166	}
2167	}
2168	return hits;
2169	}
2170
2171
2172	void BspTree::CollectViewCells(ViewCellContainer &viewCells) const
2173	{
2174	stack<BspNode *> nodeStack;
2175	nodeStack.push(mRoot);
2176
2177	ViewCell::NewMail();
2178
2179	while (!nodeStack.empty())
2180	{
2181	BspNode *node = nodeStack.top();
2182	nodeStack.pop();
2183
2184	if (node->IsLeaf())
2185	{
2186	ViewCell viewCell = dynamic_cast<BspLeaf >(node)->mViewCell;
2187
2188	if (!viewCell->Mailed())
2189	{
2190	viewCell->Mail();
2191	viewCells.push_back(viewCell);
2192	}
2193	}
2194	else
2195	{
2196	BspInterior interior = dynamic_cast<BspInterior >(node);
2197
2198	nodeStack.push(interior->GetFront());
2199	nodeStack.push(interior->GetBack());
2200	}
2201	}
2202	}
2203
2204
2205	BspTreeStatistics &BspTree::GetStat()
2206	{
2207	return mStat;
2208	}
2209
2210
2211	float BspTree::AccumulatedRayLength(BoundedRayContainer &rays) const
2212	{
2213	float len = 0;
2214
2215	BoundedRayContainer::const_iterator it, it_end = rays.end();
2216
2217	for (it = rays.begin(); it != it_end; ++ it)
2218	{
2219	len += SqrDistance((it)->mRay->Extrap((it)->mMinT),
2220	(it)->mRay->Extrap((it)->mMaxT));
2221	}
2222
2223	return len;
2224	}
2225
2226
2227	int BspTree::SplitRays(const Plane3 &plane,
2228	BoundedRayContainer &rays,
2229	BoundedRayContainer &frontRays,
2230	BoundedRayContainer &backRays)
2231	{
2232	int splits = 0;
2233
2234	while (!rays.empty())
2235	{
2236	BoundedRay *bRay = rays.back();
2237	Ray *ray = bRay->mRay;
2238	float minT = bRay->mMinT;
2239	float maxT = bRay->mMaxT;
2240
2241	rays.pop_back();
2242
2243	Vector3 entP, extP;
2244
2245	const int cf =
2246	ray->ClassifyPlane(plane, minT, maxT, entP, extP);
2247
2248	// set id to ray classification
2249	ray->SetId(cf);
2250
2251	switch (cf)
2252	{
2253	case Ray::COINCIDENT: // TODO: should really discard ray?
2254	frontRays.push_back(bRay);
2255	//DEL_PTR(bRay);
2256	break;
2257	case Ray::BACK:
2258	backRays.push_back(bRay);
2259	break;
2260	case Ray::FRONT:
2261	frontRays.push_back(bRay);
2262	break;
2263	case Ray::FRONT_BACK:
2264	{
2265	// find intersection of ray segment with plane
2266	const float t = plane.FindT(ray->GetLoc(), extP);
2267
2268	const float newT = t * maxT;
2269
2270	frontRays.push_back(new BoundedRay(ray, minT, newT));
2271	backRays.push_back(new BoundedRay(ray, newT, maxT));
2272
2273	DEL_PTR(bRay);
2274	}
2275	break;
2276	case Ray::BACK_FRONT:
2277	{
2278	// find intersection of ray segment with plane
2279	const float t = plane.FindT(ray->GetLoc(), extP);
2280	const float newT = t * bRay->mMaxT;
2281
2282	backRays.push_back(new BoundedRay(ray, minT, newT));
2283	frontRays.push_back(new BoundedRay(ray, newT, maxT));
2284
2285	DEL_PTR(bRay);
2286
2287	++ splits;
2288	}
2289	break;
2290	default:
2291	Debug << "Should not come here 4" << endl;
2292	break;
2293	}
2294	}
2295
2296	return splits;
2297	}
2298
2299	void BspTree::ExtractHalfSpaces(BspNode *n, vector<Plane3> &halfSpaces) const
2300	{
2301	BspNode *lastNode;
2302	do
2303	{
2304	lastNode = n;
2305
2306	// want to get planes defining geometry of this node => don't take
2307	// split plane of node itself
2308	n = n->GetParent();
2309
2310	if (n)
2311	{
2312	BspInterior interior = dynamic_cast<BspInterior >(n);
2313	Plane3 halfSpace = dynamic_cast<BspInterior *>(interior)->GetPlane();
2314
2315	if (interior->GetFront() != lastNode)
2316	halfSpace.ReverseOrientation();
2317
2318	halfSpaces.push_back(halfSpace);
2319	}
2320	}
2321	while (n);
2322	}
2323
2324
2325
2326	void BspTree::ConstructGeometry(ViewCell *vc,
2327	BspNodeGeometry &vcGeom) const
2328	{
2329	ViewCellContainer leaves;
2330	mViewCellsTree->CollectLeaves(vc, leaves);
2331
2332	ViewCellContainer::const_iterator it, it_end = leaves.end();
2333
2334	for (it = leaves.begin(); it != it_end; ++ it)
2335	{
2336	BspLeaf l = dynamic_cast<BspViewCell >(*it)->mLeaf;
2337	ConstructGeometry(l, vcGeom);
2338	}
2339	}
2340
2341
2342	void BspTree::SetViewCellsManager(ViewCellsManager *vcm)
2343	{
2344	mViewCellsManager = vcm;
2345	}
2346
2347
2348	void BspTree::ConstructGeometry(BspNode *n, BspNodeGeometry &geom) const
2349	{
2350	vector<Plane3> halfSpaces;
2351	ExtractHalfSpaces(n, halfSpaces);
2352
2353	PolygonContainer candidates;
2354
2355	// bounded planes are added to the polygons (reverse polygons
2356	// as they have to be outfacing
2357	for (int i = 0; i < (int)halfSpaces.size(); ++ i)
2358	{
2359	Polygon3 *p = GetBoundingBox().CrossSection(halfSpaces[i]);
2360
2361	if (p->Valid(mEpsilon))
2362	{
2363	candidates.push_back(p->CreateReversePolygon());
2364	DEL_PTR(p);
2365	}
2366	}
2367
2368	// add faces of bounding box (also could be faces of the cell)
2369	for (int i = 0; i < 6; ++ i)
2370	{
2371	VertexContainer vertices;
2372
2373	for (int j = 0; j < 4; ++ j)
2374	vertices.push_back(mBox.GetFace(i).mVertices[j]);
2375
2376	candidates.push_back(new Polygon3(vertices));
2377	}
2378
2379	for (int i = 0; i < (int)candidates.size(); ++ i)
2380	{
2381	// polygon is split by all other planes
2382	for (int j = 0; (j < (int)halfSpaces.size()) && candidates[i]; ++ j)
2383	{
2384	if (i == j) // polygon and plane are coincident
2385	continue;
2386
2387	VertexContainer splitPts;
2388	Polygon3 frontPoly, backPoly;
2389
2390	const int cf = candidates[i]->
2391	ClassifyPlane(halfSpaces[j], mEpsilon);
2392
2393	switch (cf)
2394	{
2395	case Polygon3::SPLIT:
2396	frontPoly = new Polygon3();
2397	backPoly = new Polygon3();
2398
2399	candidates[i]->Split(halfSpaces[j],
2400	*frontPoly,
2401	*backPoly,
2402	mEpsilon);
2403
2404	DEL_PTR(candidates[i]);
2405
2406	if (frontPoly->Valid(mEpsilon))
2407	candidates[i] = frontPoly;
2408	else
2409	DEL_PTR(frontPoly);
2410
2411	DEL_PTR(backPoly);
2412	break;
2413	case Polygon3::BACK_SIDE:
2414	DEL_PTR(candidates[i]);
2415	break;
2416	// just take polygon as it is
2417	case Polygon3::FRONT_SIDE:
2418	case Polygon3::COINCIDENT:
2419	default:
2420	break;
2421	}
2422	}
2423
2424	if (candidates[i])
2425	geom.mPolys.push_back(candidates[i]);
2426	}
2427	}
2428
2429
2430	typedef pair<BspNode , BspNodeGeometry > bspNodePair;
2431
2432
2433	int BspTree::FindNeighbors(BspNode n, vector<BspLeaf > &neighbors,
2434	const bool onlyUnmailed) const
2435	{
2436	stack<bspNodePair> nodeStack;
2437
2438	BspNodeGeometry nodeGeom;
2439	ConstructGeometry(n, nodeGeom);
2440
2441	// split planes from the root to this node
2442	// needed to verify that we found neighbor leaf
2443	// TODO: really needed?
2444	vector<Plane3> halfSpaces;
2445	ExtractHalfSpaces(n, halfSpaces);
2446
2447
2448	BspNodeGeometry *rgeom = new BspNodeGeometry();
2449	ConstructGeometry(mRoot, *rgeom);
2450
2451	nodeStack.push(bspNodePair(mRoot, rgeom));
2452
2453	while (!nodeStack.empty())
2454	{
2455	BspNode *node = nodeStack.top().first;
2456	BspNodeGeometry *geom = nodeStack.top().second;
2457
2458	nodeStack.pop();
2459
2460	if (node->IsLeaf())
2461	{
2462	// test if this leaf is in valid view space
2463	if (node->TreeValid() &&
2464	(node != n) &&
2465	(!onlyUnmailed \|\| !node->Mailed()))
2466	{
2467	bool isAdjacent = true;
2468
2469	if (1)
2470	{
2471	// test all planes of current node if still adjacent
2472	for (int i = 0; (i < halfSpaces.size()) && isAdjacent; ++ i)
2473	{
2474	const int cf =
2475	Polygon3::ClassifyPlane(geom->mPolys,
2476	halfSpaces[i],
2477	mEpsilon);
2478
2479	if (cf == Polygon3::BACK_SIDE)
2480	{
2481	isAdjacent = false;
2482	}
2483	}
2484	}
2485	else
2486	{
2487	// TODO: why is this wrong??
2488	// test all planes of current node if still adjacent
2489	for (int i = 0; (i < (int)nodeGeom.mPolys.size()) && isAdjacent; ++ i)
2490	{
2491	Polygon3 *poly = nodeGeom.mPolys[i];
2492
2493	const int cf =
2494	Polygon3::ClassifyPlane(geom->mPolys,
2495	poly->GetSupportingPlane(),
2496	mEpsilon);
2497
2498	if (cf == Polygon3::BACK_SIDE)
2499	{
2500	isAdjacent = false;
2501	}
2502	}
2503	}
2504	// neighbor was found
2505	if (isAdjacent)
2506	{
2507	neighbors.push_back(dynamic_cast<BspLeaf *>(node));
2508	}
2509	}
2510	}
2511	else
2512	{
2513	BspInterior interior = dynamic_cast<BspInterior >(node);
2514
2515	const int cf = Polygon3::ClassifyPlane(nodeGeom.mPolys,
2516	interior->GetPlane(),
2517	mEpsilon);
2518
2519	BspNode *front = interior->GetFront();
2520	BspNode *back = interior->GetBack();
2521
2522	BspNodeGeometry *fGeom = new BspNodeGeometry();
2523	BspNodeGeometry *bGeom = new BspNodeGeometry();
2524
2525	geom->SplitGeometry(*fGeom,
2526	*bGeom,
2527	interior->GetPlane(),
2528	mBox,
2529	mEpsilon);
2530
2531	if (cf == Polygon3::FRONT_SIDE)
2532	{
2533	nodeStack.push(bspNodePair(interior->GetFront(), fGeom));
2534	DEL_PTR(bGeom);
2535	}
2536	else
2537	{
2538	if (cf == Polygon3::BACK_SIDE)
2539	{
2540	nodeStack.push(bspNodePair(interior->GetBack(), bGeom));
2541	DEL_PTR(fGeom);
2542	}
2543	else
2544	{ // random decision
2545	nodeStack.push(bspNodePair(front, fGeom));
2546	nodeStack.push(bspNodePair(back, bGeom));
2547	}
2548	}
2549	}
2550
2551	DEL_PTR(geom);
2552	}
2553
2554	return (int)neighbors.size();
2555	}
2556
2557
2558	BspLeaf *BspTree::GetRandomLeaf(const Plane3 &halfspace)
2559	{
2560	stack<BspNode *> nodeStack;
2561	nodeStack.push(mRoot);
2562
2563	int mask = rand();
2564
2565	while (!nodeStack.empty())
2566	{
2567	BspNode *node = nodeStack.top();
2568	nodeStack.pop();
2569
2570	if (node->IsLeaf())
2571	{
2572	return dynamic_cast<BspLeaf *>(node);
2573	}
2574	else
2575	{
2576	BspInterior interior = dynamic_cast<BspInterior >(node);
2577	BspNode *next;
2578
2579	BspNodeGeometry geom;
2580	// todo: not very efficient: constructs full cell everytime
2581	ConstructGeometry(interior, geom);
2582
2583	const int cf = Polygon3::ClassifyPlane(geom.mPolys,
2584	halfspace,
2585	mEpsilon);
2586
2587	if (cf == Polygon3::BACK_SIDE)
2588	next = interior->GetFront();
2589	else
2590	if (cf == Polygon3::FRONT_SIDE)
2591	next = interior->GetFront();
2592	else
2593	{
2594	// random decision
2595	if (mask & 1)
2596	next = interior->GetBack();
2597	else
2598	next = interior->GetFront();
2599	mask = mask >> 1;
2600	}
2601
2602	nodeStack.push(next);
2603	}
2604	}
2605
2606	return NULL;
2607	}
2608
2609
2610	BspLeaf *BspTree::GetRandomLeaf(const bool onlyUnmailed)
2611	{
2612	stack<BspNode *> nodeStack;
2613
2614	nodeStack.push(mRoot);
2615
2616	int mask = rand();
2617
2618	while (!nodeStack.empty())
2619	{
2620	BspNode *node = nodeStack.top();
2621	nodeStack.pop();
2622
2623	if (node->IsLeaf())
2624	{
2625	if ( (!onlyUnmailed \|\| !node->Mailed()) )
2626	return dynamic_cast<BspLeaf *>(node);
2627	}
2628	else
2629	{
2630	BspInterior interior = dynamic_cast<BspInterior >(node);
2631
2632	// random decision
2633	if (mask & 1)
2634	nodeStack.push(interior->GetBack());
2635	else
2636	nodeStack.push(interior->GetFront());
2637
2638	mask = mask >> 1;
2639	}
2640	}
2641
2642	return NULL;
2643	}
2644
2645
2646	void BspTree::AddToPvs(BspLeaf *leaf,
2647	const BoundedRayContainer &rays,
2648	int &sampleContributions,
2649	int &contributingSamples)
2650	{
2651	sampleContributions = 0;
2652	contributingSamples = 0;
2653
2654	BoundedRayContainer::const_iterator it, it_end = rays.end();
2655
2656	ViewCell *vc = leaf->GetViewCell();
2657
2658	// add contributions from samples to the PVS
2659	for (it = rays.begin(); it != it_end; ++ it)
2660	{
2661	int contribution = 0;
2662	Ray ray = (it)->mRay;
2663	float relContribution;
2664	if (!ray->intersections.empty())
2665	contribution += vc->GetPvs().AddSample(ray->intersections[0].mObject,
2666	1.0f,
2667	relContribution);
2668
2669	if (ray->sourceObject.mObject)
2670	contribution += vc->GetPvs().AddSample(ray->sourceObject.mObject,
2671	1.0f,
2672	relContribution);
2673
2674	if (contribution)
2675	{
2676	sampleContributions += contribution;
2677	++ contributingSamples;
2678	}
2679
2680	//if (ray->mFlags & Ray::STORE_BSP_INTERSECTIONS)
2681	// ray->bspIntersections.push_back(Ray::BspIntersection((*it)->mMinT, this));
2682	}
2683	}
2684
2685
2686	int BspTree::ComputePvsSize(const BoundedRayContainer &rays) const
2687	{
2688	int pvsSize = 0;
2689
2690	BoundedRayContainer::const_iterator rit, rit_end = rays.end();
2691
2692	Intersectable::NewMail();
2693
2694	for (rit = rays.begin(); rit != rays.end(); ++ rit)
2695	{
2696	Ray ray = (rit)->mRay;
2697
2698	if (!ray->intersections.empty())
2699	{
2700	if (!ray->intersections[0].mObject->Mailed())
2701	{
2702	ray->intersections[0].mObject->Mail();
2703	++ pvsSize;
2704	}
2705	}
2706	if (ray->sourceObject.mObject)
2707	{
2708	if (!ray->sourceObject.mObject->Mailed())
2709	{
2710	ray->sourceObject.mObject->Mail();
2711	++ pvsSize;
2712	}
2713	}
2714	}
2715
2716	return pvsSize;
2717	}
2718
2719
2720	float BspTree::GetEpsilon() const
2721	{
2722	return mEpsilon;
2723	}
2724
2725
2726	int BspTree::CollectMergeCandidates(const vector<BspLeaf *> leaves,
2727	vector<MergeCandidate> &candidates)
2728	{
2729	BspLeaf::NewMail();
2730
2731	vector<BspLeaf *>::const_iterator it, it_end = leaves.end();
2732
2733	int numCandidates = 0;
2734
2735	// find merge candidates and push them into queue
2736	for (it = leaves.begin(); it != it_end; ++ it)
2737	{
2738	BspLeaf leaf = it;
2739
2740	// the same leaves must not be part of two merge candidates
2741	leaf->Mail();
2742	vector<BspLeaf *> neighbors;
2743	FindNeighbors(leaf, neighbors, true);
2744
2745	vector<BspLeaf *>::const_iterator nit, nit_end = neighbors.end();
2746
2747	// TODO: test if at least one ray goes from one leaf to the other
2748	for (nit = neighbors.begin(); nit != nit_end; ++ nit)
2749	{
2750	if ((*nit)->GetViewCell() != leaf->GetViewCell())
2751	{
2752	MergeCandidate mc(leaf->GetViewCell(), (*nit)->GetViewCell());
2753	candidates.push_back(mc);
2754
2755	++ numCandidates;
2756	if ((numCandidates % 1000) == 0)
2757	{
2758	cout << "collected " << numCandidates << " merge candidates" << endl;
2759	}
2760	}
2761	}
2762	}
2763
2764	Debug << "merge queue: " << (int)candidates.size() << endl;
2765	Debug << "leaves in queue: " << numCandidates << endl;
2766
2767
2768	return (int)leaves.size();
2769	}
2770
2771
2772	int BspTree::CollectMergeCandidates(const VssRayContainer &rays,
2773	vector<MergeCandidate> &candidates)
2774	{
2775	ViewCell::NewMail();
2776	long startTime = GetTime();
2777
2778	map<BspLeaf , vector<BspLeaf> > neighborMap;
2779	ViewCellContainer::const_iterator iit;
2780
2781	int numLeaves = 0;
2782
2783	BspLeaf::NewMail();
2784
2785	for (int i = 0; i < (int)rays.size(); ++ i)
2786	{
2787	VssRay *ray = rays[i];
2788
2789	// traverse leaves stored in the rays and compare and
2790	// merge consecutive leaves (i.e., the neighbors in the tree)
2791	if (ray->mViewCells.size() < 2)
2792	continue;
2793
2794	iit = ray->mViewCells.begin();
2795	BspViewCell bspVc = dynamic_cast<BspViewCell >(*(iit ++));
2796	BspLeaf *leaf = bspVc->mLeaf;
2797
2798	// traverse intersections
2799	// consecutive leaves are neighbors => add them to queue
2800	for (; iit != ray->mViewCells.end(); ++ iit)
2801	{
2802	// next pair
2803	BspLeaf *prevLeaf = leaf;
2804	bspVc = dynamic_cast<BspViewCell >(iit);
2805	leaf = bspVc->mLeaf;
2806
2807	// view space not valid or same view cell
2808	if (!leaf->TreeValid() \|\| !prevLeaf->TreeValid() \|\|
2809	(leaf->GetViewCell() == prevLeaf->GetViewCell()))
2810	continue;
2811
2812	vector<BspLeaf *> &neighbors = neighborMap[leaf];
2813
2814	bool found = false;
2815
2816	// both leaves inserted in queue already =>
2817	// look if double pair already exists
2818	if (leaf->Mailed() && prevLeaf->Mailed())
2819	{
2820	vector<BspLeaf *>::const_iterator it, it_end = neighbors.end();
2821
2822	for (it = neighbors.begin(); !found && (it != it_end); ++ it)
2823	if (*it == prevLeaf)
2824	found = true; // already in queue
2825	}
2826
2827	if (!found)
2828	{
2829	// this pair is not in map yet
2830	// => insert into the neighbor map and the queue
2831	neighbors.push_back(prevLeaf);
2832	neighborMap[prevLeaf].push_back(leaf);
2833
2834	leaf->Mail();
2835	prevLeaf->Mail();
2836
2837	MergeCandidate mc(leaf->GetViewCell(), prevLeaf->GetViewCell());
2838
2839	candidates.push_back(mc);
2840
2841	if (((int)candidates.size() % 1000) == 0)
2842	{
2843	cout << "collected " << (int)candidates.size() << " merge candidates" << endl;
2844	}
2845	}
2846	}
2847	}
2848
2849	Debug << "neighbormap size: " << (int)neighborMap.size() << endl;
2850	Debug << "merge queue: " << (int)candidates.size() << endl;
2851	Debug << "leaves in queue: " << numLeaves << endl;
2852
2853
2854	//-- collect the leaves which haven't been found by ray casting
2855	#if 0
2856	cout << "finding additional merge candidates using geometry" << endl;
2857	vector<BspLeaf *> leaves;
2858	CollectLeaves(leaves, true);
2859	Debug << "found " << (int)leaves.size() << " new leaves" << endl << endl;
2860	CollectMergeCandidates(leaves, candidates);
2861	#endif
2862
2863	return numLeaves;
2864	}
2865
2866
2867
2868
2869	/***************************************************************/
2870	/* BspNodeGeometry Implementation */
2871	/***************************************************************/
2872
2873
2874	BspNodeGeometry::BspNodeGeometry(const BspNodeGeometry &rhs)
2875	{
2876	mPolys.reserve(rhs.mPolys.size());
2877
2878	PolygonContainer::const_iterator it, it_end = rhs.mPolys.end();
2879	for (it = rhs.mPolys.begin(); it != it_end; ++ it)
2880	{
2881	Polygon3 poly = it;
2882	mPolys.push_back(new Polygon3(*poly));
2883	}
2884	}
2885
2886
2887	BspNodeGeometry::~BspNodeGeometry()
2888	{
2889	CLEAR_CONTAINER(mPolys);
2890	}
2891
2892
2893	float BspNodeGeometry::GetArea() const
2894	{
2895	return Polygon3::GetArea(mPolys);
2896	}
2897
2898
2899	float BspNodeGeometry::GetVolume() const
2900	{
2901	//-- compute volume using tetrahedralization of the geometry
2902	// and adding the volume of the single tetrahedrons
2903	float volume = 0;
2904	const float f = 1.0f / 6.0f;
2905
2906	PolygonContainer::const_iterator pit, pit_end = mPolys.end();
2907
2908	// note: can take arbitrary point, e.g., the origin. However,
2909	// we rather take the center of mass to prevents precision errors
2910	const Vector3 center = CenterOfMass();
2911
2912	for (pit = mPolys.begin(); pit != pit_end; ++ pit)
2913	{
2914	Polygon3 poly = pit;
2915	const Vector3 v0 = poly->mVertices[0] - center;
2916
2917	for (int i = 1; i < (int)poly->mVertices.size() - 1; ++ i)
2918	{
2919	const Vector3 v1 = poly->mVertices[i] - center;
2920	const Vector3 v2 = poly->mVertices[i + 1] - center;
2921
2922	volume += f * (DotProd(v0, CrossProd(v1, v2)));
2923	}
2924	}
2925
2926	return volume;
2927	}
2928
2929
2930	Vector3 BspNodeGeometry::CenterOfMass() const
2931	{
2932	int n = 0;
2933
2934	Vector3 center(0,0,0);
2935
2936	PolygonContainer::const_iterator pit, pit_end = mPolys.end();
2937
2938	for (pit = mPolys.begin(); pit != pit_end; ++ pit)
2939	{
2940	Polygon3 poly = pit;
2941
2942	VertexContainer::const_iterator vit, vit_end = poly->mVertices.end();
2943
2944	for(vit = poly->mVertices.begin(); vit != vit_end; ++ vit)
2945	{
2946	center += *vit;
2947	++ n;
2948	}
2949	}
2950
2951	return center / (float)n;
2952	}
2953
2954
2955	void BspNodeGeometry::AddToMesh(Mesh &mesh)
2956	{
2957	PolygonContainer::const_iterator it, it_end = mPolys.end();
2958
2959	for (it = mPolys.begin(); it != mPolys.end(); ++ it)
2960	{
2961	(*it)->AddToMesh(mesh);
2962	}
2963	}
2964
2965
2966	void BspNodeGeometry::SplitGeometry(BspNodeGeometry &front,
2967	BspNodeGeometry &back,
2968	const Plane3 &splitPlane,
2969	const AxisAlignedBox3 &box,
2970	const float epsilon) const
2971	{
2972	// get cross section of new polygon
2973	Polygon3 *planePoly = box.CrossSection(splitPlane);
2974
2975	// split polygon with all other polygons
2976	planePoly = SplitPolygon(planePoly, epsilon);
2977
2978	//-- new polygon splits all other polygons
2979	for (int i = 0; i < (int)mPolys.size(); ++ i)
2980	{
2981	/// don't use epsilon here to get exact split planes
2982	const int cf =
2983	mPolys[i]->ClassifyPlane(splitPlane, Limits::Small);
2984
2985	switch (cf)
2986	{
2987	case Polygon3::SPLIT:
2988	{
2989	Polygon3 *poly = new Polygon3(mPolys[i]->mVertices);
2990
2991	Polygon3 *frontPoly = new Polygon3();
2992	Polygon3 *backPoly = new Polygon3();
2993
2994	poly->Split(splitPlane,
2995	*frontPoly,
2996	*backPoly,
2997	epsilon);
2998
2999	DEL_PTR(poly);
3000
3001	if (frontPoly->Valid(epsilon))
3002	front.mPolys.push_back(frontPoly);
3003	else
3004	DEL_PTR(frontPoly);
3005
3006	if (backPoly->Valid(epsilon))
3007	back.mPolys.push_back(backPoly);
3008	else
3009	DEL_PTR(backPoly);
3010	}
3011
3012	break;
3013	case Polygon3::BACK_SIDE:
3014	back.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
3015	break;
3016	case Polygon3::FRONT_SIDE:
3017	front.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
3018	break;
3019	case Polygon3::COINCIDENT:
3020	//front.mPolys.push_back(CreateReversePolygon(mPolys[i]));
3021	back.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
3022	break;
3023	default:
3024	break;
3025	}
3026	}
3027
3028	//-- finally add the new polygon to the child node geometries
3029	if (planePoly)
3030	{
3031	// add polygon with normal pointing into positive half space to back cell
3032	back.mPolys.push_back(planePoly);
3033	// add polygon with reverse orientation to front cell
3034	front.mPolys.push_back(planePoly->CreateReversePolygon());
3035	}
3036	}
3037
3038
3039	Polygon3 BspNodeGeometry::SplitPolygon(Polygon3 planePoly,
3040	const float epsilon) const
3041	{
3042	if (!planePoly->Valid(epsilon))
3043	DEL_PTR(planePoly);
3044
3045	// polygon is split by all other planes
3046	for (int i = 0; (i < (int)mPolys.size()) && planePoly; ++ i)
3047	{
3048	Plane3 plane = mPolys[i]->GetSupportingPlane();
3049
3050	/// don't use epsilon here to get exact split planes
3051	const int cf =
3052	planePoly->ClassifyPlane(plane, Limits::Small);
3053
3054	// split new polygon with all previous planes
3055	switch (cf)
3056	{
3057	case Polygon3::SPLIT:
3058	{
3059	Polygon3 *frontPoly = new Polygon3();
3060	Polygon3 *backPoly = new Polygon3();
3061
3062	planePoly->Split(plane,
3063	*frontPoly,
3064	*backPoly,
3065	epsilon);
3066
3067	// don't need anymore
3068	DEL_PTR(planePoly);
3069	DEL_PTR(frontPoly);
3070
3071	// back polygon is belonging to geometry
3072	if (backPoly->Valid(epsilon))
3073	planePoly = backPoly;
3074	else
3075	DEL_PTR(backPoly);
3076	}
3077	break;
3078	case Polygon3::FRONT_SIDE:
3079	DEL_PTR(planePoly);
3080	break;
3081	// polygon is taken as it is
3082	case Polygon3::BACK_SIDE:
3083	case Polygon3::COINCIDENT:
3084	default:
3085	break;
3086	}
3087	}
3088
3089	return planePoly;
3090	}
3091
3092
3093	ViewCell *
3094	BspTree::GetViewCell(const Vector3 &point)
3095	{
3096	if (mRoot == NULL)
3097	return NULL;
3098
3099
3100	stack<BspNode *> nodeStack;
3101	nodeStack.push(mRoot);
3102
3103	ViewCell *viewcell = NULL;
3104
3105	while (!nodeStack.empty()) {
3106	BspNode *node = nodeStack.top();
3107	nodeStack.pop();
3108
3109	if (node->IsLeaf()) {
3110	viewcell = dynamic_cast<BspLeaf *>(node)->mViewCell;
3111	break;
3112	} else {
3113
3114	BspInterior interior = dynamic_cast<BspInterior >(node);
3115
3116	// random decision
3117	if (interior->GetPlane().Side(point) < 0)
3118	nodeStack.push(interior->GetBack());
3119	else
3120	nodeStack.push(interior->GetFront());
3121	}
3122	}
3123
3124	return viewcell;
3125	}
3126
3127
3128	void BspNodeGeometry::IncludeInBox(AxisAlignedBox3 &box)
3129	{
3130	Polygon3::IncludeInBox(mPolys, box);
3131	}
3132
3133
3134	bool BspTree::Export(ofstream &stream)
3135	{
3136	ExportNode(mRoot, stream);
3137
3138	return true;
3139	}
3140
3141
3142	void BspTree::ExportNode(BspNode *node, ofstream &stream)
3143	{
3144	if (node->IsLeaf())
3145	{
3146	BspLeaf leaf = dynamic_cast<BspLeaf >(node);
3147
3148	int id = -1;
3149	if (leaf->GetViewCell() != mOutOfBoundsCell)
3150	id = leaf->GetViewCell()->GetId();
3151
3152	stream << "<Leaf viewCellId=\"" << id << "\" />" << endl;
3153	}
3154	else
3155	{
3156	BspInterior interior = dynamic_cast<BspInterior >(node);
3157
3158	Plane3 plane = interior->GetPlane();
3159	stream << "<Interior plane=\"" << plane.mNormal.x << " "
3160	<< plane.mNormal.y << " " << plane.mNormal.z << " "
3161	<< plane.mD << "\">" << endl;
3162
3163	ExportNode(interior->GetBack(), stream);
3164	ExportNode(interior->GetFront(), stream);
3165
3166	stream << "</Interior>" << endl;
3167	}
3168	}

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