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source: GTP/trunk/Lib/Vis/Preprocessing/src/ViewCellBsp.cpp @ 681

Revision 681, 78.9 KB checked in by mattausch, 18 years ago (diff)
debug version

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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
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	//float probability = max(0.0f, tData.mProbability);
983	float probability = tData.mProbability;
984
985	if (mUseAreaForPvs)
986	viewCell->SetArea(probability);
987	else
988	viewCell->SetVolume(probability);
989
990	//-- add pvs
991	if (viewCell != mOutOfBoundsCell)
992	{
993	int conSamp = 0, sampCon = 0;
994	AddToPvs(leaf, *tData.mRays, conSamp, sampCon);
995
996	mStat.contributingSamples += conSamp;
997	mStat.sampleContributions += sampCon;
998	}
999
1000	EvaluateLeafStats(tData);
1001
1002	//-- clean up
1003
1004	// discard polygons
1005	CLEAR_CONTAINER(*tData.mPolygons);
1006	// discard rays
1007	CLEAR_CONTAINER(*tData.mRays);
1008
1009	DEL_PTR(tData.mPolygons);
1010	DEL_PTR(tData.mRays);
1011	DEL_PTR(tData.mGeometry);
1012
1013	return leaf;
1014	}
1015
1016	//-- continue subdivision
1017	PolygonContainer coincident;
1018
1019	BspTraversalData tFrontData(NULL, new PolygonContainer(), tData.mDepth + 1, mOutOfBoundsCell,
1020	new BoundedRayContainer(), 0, 0, new BspNodeGeometry());
1021	BspTraversalData tBackData(NULL, new PolygonContainer(), tData.mDepth + 1, mOutOfBoundsCell,
1022	new BoundedRayContainer(), 0, 0, new BspNodeGeometry());
1023
1024
1025	// create new interior node and two leaf nodes
1026	BspInterior *interior =
1027	SubdivideNode(tData, tFrontData, tBackData, coincident);
1028
1029
1030	if (1)
1031	{
1032	int pvsData = tData.mPvs;
1033
1034	float cData = (float)pvsData * tData.mProbability;
1035	float cFront = (float)tFrontData.mPvs * tFrontData.mProbability;
1036	float cBack = (float)tBackData.mPvs * tBackData.mProbability;
1037
1038	float costDecr = (cFront + cBack - cData) / mBox.GetVolume();
1039
1040	mTotalCost += costDecr;
1041	mTotalPvsSize += tFrontData.mPvs + tBackData.mPvs - pvsData;
1042
1043	mSubdivisionStats
1044	<< "#ViewCells\n" << mStat.Leaves() << endl
1045	<< "#RenderCostDecrease\n" << -costDecr << endl
1046	<< "#TotalRenderCost\n" << mTotalCost << endl
1047	<< "#AvgRenderCost\n" << mTotalPvsSize / mStat.Leaves() << endl;
1048	}
1049
1050	// extract view cells from coincident polygons according to plane normal
1051	// only if front or back polygons are empty
1052	if (!mGenerateViewCells)
1053	{
1054	ExtractViewCells(tFrontData,
1055	tBackData,
1056	coincident,
1057	interior->mPlane);
1058	}
1059
1060	// don't need coincident polygons anymory
1061	CLEAR_CONTAINER(coincident);
1062
1063	// push the children on the stack
1064	tStack.push(tFrontData);
1065	tStack.push(tBackData);
1066
1067	// cleanup
1068	DEL_PTR(tData.mNode);
1069
1070	DEL_PTR(tData.mPolygons);
1071	DEL_PTR(tData.mRays);
1072	DEL_PTR(tData.mGeometry);
1073
1074	return interior;
1075	}
1076
1077
1078	void BspTree::ExtractViewCells(BspTraversalData &frontData,
1079	BspTraversalData &backData,
1080	const PolygonContainer &coincident,
1081	const Plane3 &splitPlane) const
1082	{
1083	// if not empty, tree is further subdivided => don't have to find view cell
1084	bool foundFront = !frontData.mPolygons->empty();
1085	bool foundBack = !frontData.mPolygons->empty();
1086
1087	PolygonContainer::const_iterator it =
1088	coincident.begin(), it_end = coincident.end();
1089
1090	//-- find first view cells in front and back leafs
1091	for (; !(foundFront && foundBack) && (it != it_end); ++ it)
1092	{
1093	if (DotProd((*it)->GetNormal(), splitPlane.mNormal) > 0)
1094	{
1095	backData.mViewCell = dynamic_cast<ViewCell >((it)->mParent);
1096	foundBack = true;
1097	}
1098	else
1099	{
1100	frontData.mViewCell = dynamic_cast<ViewCell >((it)->mParent);
1101	foundFront = true;
1102	}
1103	}
1104	}
1105
1106
1107	BspInterior *BspTree::SubdivideNode(BspTraversalData &tData,
1108	BspTraversalData &frontData,
1109	BspTraversalData &backData,
1110	PolygonContainer &coincident)
1111	{
1112	mStat.nodes += 2;
1113
1114	BspLeaf leaf = dynamic_cast<BspLeaf >(tData.mNode);
1115
1116
1117
1118	// select subdivision plane
1119	BspInterior *interior =
1120	new BspInterior(SelectPlane(leaf, tData));
1121
1122
1123	#ifdef _DEBUG
1124	Debug << interior << endl;
1125	#endif
1126
1127
1128	// subdivide rays into front and back rays
1129	SplitRays(interior->mPlane, tData.mRays, frontData.mRays, *backData.mRays);
1130
1131
1132
1133	// subdivide polygons with plane
1134	mStat.polySplits += SplitPolygons(interior->GetPlane(),
1135	*tData.mPolygons,
1136	*frontData.mPolygons,
1137	*backData.mPolygons,
1138	coincident);
1139
1140
1141
1142	// compute pvs
1143	frontData.mPvs = ComputePvsSize(*frontData.mRays);
1144	backData.mPvs = ComputePvsSize(*backData.mRays);
1145
1146	// split geometry and compute area
1147	if (1)
1148	{
1149	tData.mGeometry->SplitGeometry(*frontData.mGeometry,
1150	*backData.mGeometry,
1151	interior->mPlane,
1152	mBox,
1153	//0.000000000001);
1154	mEpsilon);
1155
1156
1157	if (mUseAreaForPvs)
1158	{
1159	frontData.mProbability = frontData.mGeometry->GetArea();
1160	backData.mProbability = backData.mGeometry->GetArea();
1161	}
1162	else
1163	{
1164	frontData.mProbability = frontData.mGeometry->GetVolume();
1165	backData.mProbability = tData.mProbability - frontData.mProbability;
1166	}
1167	}
1168
1169	//-- create front and back leaf
1170
1171	BspInterior *parent = leaf->GetParent();
1172
1173	// replace a link from node's parent
1174	if (!leaf->IsRoot())
1175	{
1176	parent->ReplaceChildLink(leaf, interior);
1177	interior->SetParent(parent);
1178	}
1179	else // new root
1180	{
1181	mRoot = interior;
1182	}
1183
1184	// and setup child links
1185	interior->SetupChildLinks(new BspLeaf(interior), new BspLeaf(interior));
1186
1187	frontData.mNode = interior->GetFront();
1188	backData.mNode = interior->GetBack();
1189
1190	interior->mTimeStamp = mTimeStamp ++;
1191
1192	//DEL_PTR(leaf);
1193	return interior;
1194	}
1195
1196
1197	void BspTree::SortSplitCandidates(const PolygonContainer &polys,
1198	const int axis,
1199	vector<SortableEntry> &splitCandidates) const
1200	{
1201	splitCandidates.clear();
1202
1203	int requestedSize = 2 * (int)polys.size();
1204	// creates a sorted split candidates array
1205	splitCandidates.reserve(requestedSize);
1206
1207	PolygonContainer::const_iterator it, it_end = polys.end();
1208
1209	AxisAlignedBox3 box;
1210
1211	// insert all queries
1212	for(it = polys.begin(); it != it_end; ++ it)
1213	{
1214	box.Initialize();
1215	box.Include((it));
1216
1217	splitCandidates.push_back(SortableEntry(SortableEntry::POLY_MIN, box.Min(axis), *it));
1218	splitCandidates.push_back(SortableEntry(SortableEntry::POLY_MAX, box.Max(axis), *it));
1219	}
1220
1221	stable_sort(splitCandidates.begin(), splitCandidates.end());
1222	}
1223
1224
1225	float BspTree::BestCostRatio(const PolygonContainer &polys,
1226	const AxisAlignedBox3 &box,
1227	const int axis,
1228	float &position,
1229	int &objectsBack,
1230	int &objectsFront) const
1231	{
1232	vector<SortableEntry> splitCandidates;
1233
1234	SortSplitCandidates(polys, axis, splitCandidates);
1235
1236	// go through the lists, count the number of objects left and right
1237	// and evaluate the following cost funcion:
1238	// C = ct_div_ci + (ol + or)/queries
1239
1240	int objectsLeft = 0, objectsRight = (int)polys.size();
1241
1242	float minBox = box.Min(axis);
1243	float maxBox = box.Max(axis);
1244	float boxArea = box.SurfaceArea();
1245
1246	float minBand = minBox + mSplitBorder * (maxBox - minBox);
1247	float maxBand = minBox + (1.0f - mSplitBorder) * (maxBox - minBox);
1248
1249	float minSum = 1e20f;
1250	vector<SortableEntry>::const_iterator ci, ci_end = splitCandidates.end();
1251
1252	for(ci = splitCandidates.begin(); ci != ci_end; ++ ci)
1253	{
1254	switch ((*ci).type)
1255	{
1256	case SortableEntry::POLY_MIN:
1257	++ objectsLeft;
1258	break;
1259	case SortableEntry::POLY_MAX:
1260	-- objectsRight;
1261	break;
1262	default:
1263	break;
1264	}
1265
1266	if ((ci).value > minBand && (ci).value < maxBand)
1267	{
1268	AxisAlignedBox3 lbox = box;
1269	AxisAlignedBox3 rbox = box;
1270	lbox.SetMax(axis, (*ci).value);
1271	rbox.SetMin(axis, (*ci).value);
1272
1273	const float sum = objectsLeft * lbox.SurfaceArea() +
1274	objectsRight * rbox.SurfaceArea();
1275
1276	if (sum < minSum)
1277	{
1278	minSum = sum;
1279	position = (*ci).value;
1280
1281	objectsBack = objectsLeft;
1282	objectsFront = objectsRight;
1283	}
1284	}
1285	}
1286
1287	const float oldCost = (float)polys.size();
1288	const float newCost = mAxisAlignedCtDivCi + minSum / boxArea;
1289	const float ratio = newCost / oldCost;
1290
1291
1292	#if 0
1293	Debug << "====================" << endl;
1294	Debug << "costRatio=" << ratio << " pos=" << position<<" t=" << (position - minBox)/(maxBox - minBox)
1295	<< "\t o=(" << objectsBack << "," << objectsFront << ")" << endl;
1296	#endif
1297	return ratio;
1298	}
1299
1300	bool BspTree::SelectAxisAlignedPlane(Plane3 &plane,
1301	const PolygonContainer &polys) const
1302	{
1303	AxisAlignedBox3 box;
1304	box.Initialize();
1305
1306	// create bounding box of region
1307	Polygon3::IncludeInBox(polys, box);
1308
1309	int objectsBack = 0, objectsFront = 0;
1310	int axis = 0;
1311	float costRatio = MAX_FLOAT;
1312	Vector3 position;
1313
1314	//-- area subdivision
1315	for (int i = 0; i < 3; ++ i)
1316	{
1317	float p = 0;
1318	float r = BestCostRatio(polys, box, i, p, objectsBack, objectsFront);
1319
1320	if (r < costRatio)
1321	{
1322	costRatio = r;
1323	axis = i;
1324	position = p;
1325	}
1326	}
1327
1328	if (costRatio >= mMaxCostRatio)
1329	return false;
1330
1331	Vector3 norm(0,0,0); norm[axis] = 1.0f;
1332	plane = Plane3(norm, position);
1333
1334	return true;
1335	}
1336
1337
1338	Plane3 BspTree::SelectPlane(BspLeaf *leaf, BspTraversalData &data)
1339	{
1340	if ((!mMaxPolyCandidates \|\| data.mPolygons->empty()) &&
1341	(!mMaxRayCandidates \|\| data.mRays->empty()))
1342	{
1343	Debug << "Warning: No autopartition polygon candidate available\n";
1344
1345	// return axis aligned split
1346	AxisAlignedBox3 box;
1347	box.Initialize();
1348
1349	// create bounding box of region
1350	Polygon3::IncludeInBox(*data.mPolygons, box);
1351
1352	const int axis = box.Size().DrivingAxis();
1353	const Vector3 position = (box.Min()[axis] + box.Max()[axis]) * 0.5f;
1354
1355	Vector3 norm(0,0,0); norm[axis] = 1.0f;
1356	return Plane3(norm, position);
1357	}
1358
1359	if ((mSplitPlaneStrategy & AXIS_ALIGNED) &&
1360	((int)data.mPolygons->size() > mTermMinPolysForAxisAligned) &&
1361	((int)data.mRays->size() > mTermMinRaysForAxisAligned) &&
1362	((mTermMinObjectsForAxisAligned < 0) \|\|
1363	(Polygon3::ParentObjectsSize(*data.mPolygons) > mTermMinObjectsForAxisAligned)))
1364	{
1365	Plane3 plane;
1366	if (SelectAxisAlignedPlane(plane, *data.mPolygons))
1367	return plane;
1368	}
1369
1370	// simplest strategy: just take next polygon
1371	if (mSplitPlaneStrategy & RANDOM_POLYGON)
1372	{
1373	if (!data.mPolygons->empty())
1374	{
1375	Polygon3 *nextPoly =
1376	(*data.mPolygons)[(int)RandomValue(0, (Real)((int)data.mPolygons->size() - 1))];
1377	return nextPoly->GetSupportingPlane();
1378	}
1379	else
1380	{
1381	const int candidateIdx = (int)RandomValue(0, (Real)((int)data.mRays->size() - 1));
1382	BoundedRay bRay = (data.mRays)[candidateIdx];
1383
1384	Ray *ray = bRay->mRay;
1385
1386	const Vector3 minPt = ray->Extrap(bRay->mMinT);
1387	const Vector3 maxPt = ray->Extrap(bRay->mMaxT);
1388
1389	const Vector3 pt = (maxPt + minPt) * 0.5;
1390
1391	const Vector3 normal = ray->GetDir();
1392
1393	return Plane3(normal, pt);
1394	}
1395
1396	return Plane3();
1397	}
1398
1399	// use heuristics to find appropriate plane
1400	return SelectPlaneHeuristics(leaf, data);
1401	}
1402
1403
1404	Plane3 BspTree::ChooseCandidatePlane(const BoundedRayContainer &rays) const
1405	{
1406	const int candidateIdx = (int)RandomValue(0, (Real)((int)rays.size() - 1));
1407	BoundedRay *bRay = rays[candidateIdx];
1408	Ray *ray = bRay->mRay;
1409
1410	const Vector3 minPt = ray->Extrap(bRay->mMinT);
1411	const Vector3 maxPt = ray->Extrap(bRay->mMaxT);
1412
1413	const Vector3 pt = (maxPt + minPt) * 0.5;
1414
1415	const Vector3 normal = ray->GetDir();
1416
1417	return Plane3(normal, pt);
1418	}
1419
1420	Plane3 BspTree::ChooseCandidatePlane2(const BoundedRayContainer &rays) const
1421	{
1422	Vector3 pt[3];
1423	int idx[3];
1424	int cmaxT = 0;
1425	int cminT = 0;
1426	bool chooseMin = false;
1427
1428	for (int j = 0; j < 3; j ++)
1429	{
1430	idx[j] = (int)RandomValue(0, Real((int)rays.size() * 2 - 1));
1431
1432	if (idx[j] >= (int)rays.size())
1433	{
1434	idx[j] -= (int)rays.size();
1435	chooseMin = (cminT < 2);
1436	}
1437	else
1438	chooseMin = (cmaxT < 2);
1439
1440	BoundedRay *bRay = rays[idx[j]];
1441	pt[j] = chooseMin ? bRay->mRay->Extrap(bRay->mMinT) :
1442	bRay->mRay->Extrap(bRay->mMaxT);
1443	}
1444
1445	return Plane3(pt[0], pt[1], pt[2]);
1446	}
1447
1448	Plane3 BspTree::ChooseCandidatePlane3(const BoundedRayContainer &rays) const
1449	{
1450	Vector3 pt[3];
1451
1452	int idx1 = (int)RandomValue(0, (Real)((int)rays.size() - 1));
1453	int idx2 = (int)RandomValue(0, (Real)((int)rays.size() - 1));
1454
1455	// check if rays different
1456	if (idx1 == idx2)
1457	idx2 = (idx2 + 1) % (int)rays.size();
1458
1459	const BoundedRay *ray1 = rays[idx1];
1460	const BoundedRay *ray2 = rays[idx2];
1461
1462	// normal vector of the plane parallel to both lines
1463	const Vector3 norm =
1464	Normalize(CrossProd(ray1->mRay->GetDir(), ray2->mRay->GetDir()));
1465
1466	const Vector3 orig1 = ray1->mRay->Extrap(ray1->mMinT);
1467	const Vector3 orig2 = ray2->mRay->Extrap(ray2->mMinT);
1468
1469	// vector from line 1 to line 2
1470	const Vector3 vd = orig1 - orig2;
1471
1472	// project vector on normal to get distance
1473	const float dist = DotProd(vd, norm);
1474
1475	// point on plane lies halfway between the two planes
1476	const Vector3 planePt = orig1 + norm * dist * 0.5;
1477
1478	return Plane3(norm, planePt);
1479	}
1480
1481
1482	Plane3 BspTree::SelectPlaneHeuristics(BspLeaf *leaf, BspTraversalData &data)
1483	{
1484	float lowestCost = MAX_FLOAT;
1485	Plane3 bestPlane;
1486	// intermediate plane
1487	Plane3 plane;
1488
1489	const int limit = Min((int)data.mPolygons->size(), mMaxPolyCandidates);
1490	int maxIdx = (int)data.mPolygons->size();
1491
1492	for (int i = 0; i < limit; ++ i)
1493	{
1494	// assure that no index is taken twice
1495	const int candidateIdx = (int)RandomValue(0, (Real)(-- maxIdx));
1496
1497	Polygon3 poly = (data.mPolygons)[candidateIdx];
1498
1499	// swap candidate to the end to avoid testing same plane
1500	std::swap((data.mPolygons)[maxIdx], (data.mPolygons)[candidateIdx]);
1501	//Polygon3 poly = (data.mPolygons)[(int)RandomValue(0, (int)polys.size() - 1)];
1502
1503	// evaluate current candidate
1504	const float candidateCost =
1505	SplitPlaneCost(poly->GetSupportingPlane(), data);
1506
1507	if (candidateCost < lowestCost)
1508	{
1509	bestPlane = poly->GetSupportingPlane();
1510	lowestCost = candidateCost;
1511	}
1512	}
1513
1514	//-- choose candidate planes extracted from rays
1515	for (int i = 0; i < mMaxRayCandidates; ++ i)
1516	{
1517	plane = ChooseCandidatePlane3(*data.mRays);
1518	const float candidateCost = SplitPlaneCost(plane, data);
1519
1520	if (candidateCost < lowestCost)
1521	{
1522	bestPlane = plane;
1523	lowestCost = candidateCost;
1524	}
1525	}
1526
1527	#ifdef _DEBUG
1528	Debug << "plane lowest cost: " << lowestCost << endl;
1529	#endif
1530
1531	return bestPlane;
1532	}
1533
1534
1535	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1536	const PolygonContainer &polys) const
1537	{
1538	float val = 0;
1539
1540	float sumBalancedPolys = 0;
1541	float sumSplits = 0;
1542	float sumPolyArea = 0;
1543	float sumBalancedViewCells = 0;
1544	float sumBlockedRays = 0;
1545	float totalBlockedRays = 0;
1546	//float totalArea = 0;
1547	int totalViewCells = 0;
1548
1549	// need three unique ids for each type of view cell
1550	// for balanced view cells criterium
1551	ViewCell::NewMail();
1552	const int backId = ViewCell::sMailId;
1553	ViewCell::NewMail();
1554	const int frontId = ViewCell::sMailId;
1555	ViewCell::NewMail();
1556	const int frontAndBackId = ViewCell::sMailId;
1557
1558	bool useRand;
1559	int limit;
1560
1561	// choose test polyongs randomly if over threshold
1562	if ((int)polys.size() > mMaxTests)
1563	{
1564	useRand = true;
1565	limit = mMaxTests;
1566	}
1567	else
1568	{
1569	useRand = false;
1570	limit = (int)polys.size();
1571	}
1572
1573	for (int i = 0; i < limit; ++ i)
1574	{
1575	const int testIdx = useRand ? (int)RandomValue(0, (Real)(limit - 1)) : i;
1576
1577	Polygon3 *poly = polys[testIdx];
1578
1579	const int classification =
1580	poly->ClassifyPlane(candidatePlane, mEpsilon);
1581
1582	if (mSplitPlaneStrategy & BALANCED_POLYS)
1583	sumBalancedPolys += sBalancedPolysTable[classification];
1584
1585	if (mSplitPlaneStrategy & LEAST_SPLITS)
1586	sumSplits += sLeastPolySplitsTable[classification];
1587
1588	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
1589	{
1590	if (classification == Polygon3::COINCIDENT)
1591	sumPolyArea += poly->GetArea();
1592	//totalArea += area;
1593	}
1594
1595	if (mSplitPlaneStrategy & BLOCKED_RAYS)
1596	{
1597	const float blockedRays = (float)poly->mPiercingRays.size();
1598
1599	if (classification == Polygon3::COINCIDENT)
1600	sumBlockedRays += blockedRays;
1601
1602	totalBlockedRays += blockedRays;
1603	}
1604
1605	// assign view cells to back or front according to classificaion
1606	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
1607	{
1608	MeshInstance *viewCell = poly->mParent;
1609
1610	// assure that we only count a view cell
1611	// once for the front and once for the back side of the plane
1612	if (classification == Polygon3::FRONT_SIDE)
1613	{
1614	if ((viewCell->mMailbox != frontId) &&
1615	(viewCell->mMailbox != frontAndBackId))
1616	{
1617	sumBalancedViewCells += 1.0;
1618
1619	if (viewCell->mMailbox != backId)
1620	viewCell->mMailbox = frontId;
1621	else
1622	viewCell->mMailbox = frontAndBackId;
1623
1624	++ totalViewCells;
1625	}
1626	}
1627	else if (classification == Polygon3::BACK_SIDE)
1628	{
1629	if ((viewCell->mMailbox != backId) &&
1630	(viewCell->mMailbox != frontAndBackId))
1631	{
1632	sumBalancedViewCells -= 1.0;
1633
1634	if (viewCell->mMailbox != frontId)
1635	viewCell->mMailbox = backId;
1636	else
1637	viewCell->mMailbox = frontAndBackId;
1638
1639	++ totalViewCells;
1640	}
1641	}
1642	}
1643	}
1644
1645	const float polysSize = (float)polys.size() + Limits::Small;
1646
1647	// all values should be approx. between 0 and 1 so they can be combined
1648	// and scaled with the factors according to their importance
1649	if (mSplitPlaneStrategy & BALANCED_POLYS)
1650	val += mBalancedPolysFactor * fabs(sumBalancedPolys) / polysSize;
1651
1652	if (mSplitPlaneStrategy & LEAST_SPLITS)
1653	val += mLeastSplitsFactor * sumSplits / polysSize;
1654
1655	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
1656	// HACK: polys.size should be total area so scaling is between 0 and 1
1657	val += mLargestPolyAreaFactor * (float)polys.size() / sumPolyArea;
1658
1659	if (mSplitPlaneStrategy & BLOCKED_RAYS)
1660	if (totalBlockedRays != 0)
1661	val += mBlockedRaysFactor * (totalBlockedRays - sumBlockedRays) / totalBlockedRays;
1662
1663	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
1664	val += mBalancedViewCellsFactor * fabs(sumBalancedViewCells) /
1665	((float)totalViewCells + Limits::Small);
1666
1667	return val;
1668	}
1669
1670
1671	inline void BspTree::GenerateUniqueIdsForPvs()
1672	{
1673	ViewCell::NewMail(); sBackId = ViewCell::sMailId;
1674	ViewCell::NewMail(); sFrontId = ViewCell::sMailId;
1675	ViewCell::NewMail(); sFrontAndBackId = ViewCell::sMailId;
1676	}
1677
1678
1679	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1680	const BoundedRayContainer &rays,
1681	const int pvs,
1682	const float probability,
1683	const BspNodeGeometry &cell) const
1684	{
1685	float val = 0;
1686
1687	float sumBalancedRays = 0;
1688	float sumRaySplits = 0;
1689
1690	int frontPvs = 0;
1691	int backPvs = 0;
1692
1693	// probability that view point lies in child
1694	float pOverall = 0;
1695	float pFront = 0;
1696	float pBack = 0;
1697
1698	const bool pvsUseLen = false;
1699
1700	if (mSplitPlaneStrategy & PVS)
1701	{
1702	// create unique ids for pvs heuristics
1703	GenerateUniqueIdsForPvs();
1704
1705	// construct child geometry with regard to the candidate split plane
1706	BspNodeGeometry frontCell;
1707	BspNodeGeometry backCell;
1708
1709	cell.SplitGeometry(frontCell,
1710	backCell,
1711	candidatePlane,
1712	mBox,
1713	mEpsilon);
1714
1715	if (mUseAreaForPvs)
1716	{
1717	pFront = frontCell.GetArea();
1718	pBack = backCell.GetArea();
1719	}
1720	else
1721	{
1722	pFront = frontCell.GetVolume();
1723	pBack = pOverall - pFront;
1724	}
1725
1726
1727	pOverall = probability;
1728	}
1729
1730	bool useRand;
1731	int limit;
1732
1733	// choose test polyongs randomly if over threshold
1734	if ((int)rays.size() > mMaxTests)
1735	{
1736	useRand = true;
1737	limit = mMaxTests;
1738	}
1739	else
1740	{
1741	useRand = false;
1742	limit = (int)rays.size();
1743	}
1744
1745	for (int i = 0; i < limit; ++ i)
1746	{
1747	const int testIdx = useRand ? (int)RandomValue(0, (Real)(limit - 1)) : i;
1748
1749	BoundedRay *bRay = rays[testIdx];
1750
1751	Ray *ray = bRay->mRay;
1752	const float minT = bRay->mMinT;
1753	const float maxT = bRay->mMaxT;
1754
1755	Vector3 entP, extP;
1756
1757	const int cf =
1758	ray->ClassifyPlane(candidatePlane, minT, maxT, entP, extP);
1759
1760	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
1761	{
1762	sumBalancedRays += sBalancedRaysTable[cf];
1763	}
1764
1765	if (mSplitPlaneStrategy & BALANCED_RAYS)
1766	{
1767	sumRaySplits += sLeastRaySplitsTable[cf];
1768	}
1769
1770	if (mSplitPlaneStrategy & PVS)
1771	{
1772	// in case the ray intersects an object
1773	// assure that we only count the object
1774	// once for the front and once for the back side of the plane
1775
1776	// add the termination object
1777	if (!ray->intersections.empty())
1778	AddObjToPvs(ray->intersections[0].mObject, cf, frontPvs, backPvs);
1779
1780	// add the source object
1781	AddObjToPvs(ray->sourceObject.mObject, cf, frontPvs, backPvs);
1782	}
1783	}
1784
1785	const float raysSize = (float)rays.size() + Limits::Small;
1786
1787	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
1788	val += mLeastRaySplitsFactor * sumRaySplits / raysSize;
1789
1790	if (mSplitPlaneStrategy & BALANCED_RAYS)
1791	val += mBalancedRaysFactor * fabs(sumBalancedRays) / raysSize;
1792
1793	const float denom = pOverall * (float)pvs * 2.0f + Limits::Small;
1794
1795	if (mSplitPlaneStrategy & PVS)
1796	{
1797	val += mPvsFactor * (frontPvs * pFront + (backPvs * pBack)) / denom;
1798
1799	// give penalty to unbalanced split
1800	if (0)
1801	if (((pFront * 0.2 + Limits::Small) > pBack) \|\|
1802	(pFront < (pBack * 0.2 + Limits::Small)))
1803	val += 0.5;
1804	}
1805
1806
1807	#ifdef _DEBUG
1808	Debug << "totalpvs: " << pvs << " ptotal: " << pOverall
1809	<< " frontpvs: " << frontPvs << " pFront: " << pFront
1810	<< " backpvs: " << backPvs << " pBack: " << pBack << endl << endl;
1811	#endif
1812
1813	return val;
1814	}
1815
1816	void BspTree::AddObjToPvs(Intersectable *obj,
1817	const int cf,
1818	int &frontPvs,
1819	int &backPvs) const
1820	{
1821	if (!obj)
1822	return;
1823	// TODO: does this really belong to no pvs?
1824	//if (cf == Ray::COINCIDENT) return;
1825
1826	// object belongs to both PVS
1827	const bool bothSides = (cf == Ray::FRONT_BACK) \|\|
1828	(cf == Ray::BACK_FRONT) \|\|
1829	(cf == Ray::COINCIDENT);
1830
1831	if ((cf == Ray::FRONT) \|\| bothSides)
1832	{
1833	if ((obj->mMailbox != sFrontId) &&
1834	(obj->mMailbox != sFrontAndBackId))
1835	{
1836	++ frontPvs;
1837
1838	if (obj->mMailbox == sBackId)
1839	obj->mMailbox = sFrontAndBackId;
1840	else
1841	obj->mMailbox = sFrontId;
1842	}
1843	}
1844
1845	if ((cf == Ray::BACK) \|\| bothSides)
1846	{
1847	if ((obj->mMailbox != sBackId) &&
1848	(obj->mMailbox != sFrontAndBackId))
1849	{
1850	++ backPvs;
1851
1852	if (obj->mMailbox == sFrontId)
1853	obj->mMailbox = sFrontAndBackId;
1854	else
1855	obj->mMailbox = sBackId;
1856	}
1857	}
1858	}
1859
1860
1861	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1862	BspTraversalData &data) const
1863	{
1864	float val = 0;
1865
1866	if (mSplitPlaneStrategy & VERTICAL_AXIS)
1867	{
1868	Vector3 tinyAxis(0,0,0); tinyAxis[mBox.Size().TinyAxis()] = 1.0f;
1869	// we put a penalty on the dot product between the "tiny" vertical axis
1870	// and the split plane axis
1871	val += mVerticalSplitsFactor *
1872	fabs(DotProd(candidatePlane.mNormal, tinyAxis));
1873	}
1874
1875	// the following criteria loop over all polygons to find the cost value
1876	if ((mSplitPlaneStrategy & BALANCED_POLYS) \|\|
1877	(mSplitPlaneStrategy & LEAST_SPLITS) \|\|
1878	(mSplitPlaneStrategy & LARGEST_POLY_AREA) \|\|
1879	(mSplitPlaneStrategy & BALANCED_VIEW_CELLS) \|\|
1880	(mSplitPlaneStrategy & BLOCKED_RAYS))
1881	{
1882	val += SplitPlaneCost(candidatePlane, *data.mPolygons);
1883	}
1884
1885	// the following criteria loop over all rays to find the cost value
1886	if ((mSplitPlaneStrategy & BALANCED_RAYS) \|\|
1887	(mSplitPlaneStrategy & LEAST_RAY_SPLITS) \|\|
1888	(mSplitPlaneStrategy & PVS))
1889	{
1890	val += SplitPlaneCost(candidatePlane, *data.mRays, data.mPvs,
1891	data.mProbability, *data.mGeometry);
1892	}
1893
1894	// return linear combination of the sums
1895	return val;
1896	}
1897
1898	void BspTree::CollectLeaves(vector<BspLeaf *> &leaves) const
1899	{
1900	stack<BspNode *> nodeStack;
1901	nodeStack.push(mRoot);
1902
1903	while (!nodeStack.empty())
1904	{
1905	BspNode *node = nodeStack.top();
1906
1907	nodeStack.pop();
1908
1909	if (node->IsLeaf())
1910	{
1911	BspLeaf leaf = (BspLeaf )node;
1912	leaves.push_back(leaf);
1913	}
1914	else
1915	{
1916	BspInterior interior = dynamic_cast<BspInterior >(node);
1917
1918	nodeStack.push(interior->GetBack());
1919	nodeStack.push(interior->GetFront());
1920	}
1921	}
1922	}
1923
1924
1925	AxisAlignedBox3 BspTree::GetBoundingBox() const
1926	{
1927	return mBox;
1928	}
1929
1930
1931	void BspTree::EvaluateLeafStats(const BspTraversalData &data)
1932	{
1933	// the node became a leaf -> evaluate stats for leafs
1934	BspLeaf leaf = dynamic_cast<BspLeaf >(data.mNode);
1935
1936	// store maximal and minimal depth
1937	if (data.mDepth > mStat.maxDepth)
1938	mStat.maxDepth = data.mDepth;
1939
1940	if (data.mDepth < mStat.minDepth)
1941	mStat.minDepth = data.mDepth;
1942
1943	// accumulate depth to compute average depth
1944	mStat.accumDepth += data.mDepth;
1945	// accumulate rays to compute rays / leaf
1946	mStat.accumRays += (int)data.mRays->size();
1947
1948	if (data.mDepth >= mTermMaxDepth)
1949	++ mStat.maxDepthNodes;
1950
1951	if (data.mPvs < mTermMinPvs)
1952	++ mStat.minPvsNodes;
1953
1954	if ((int)data.mRays->size() < mTermMinRays)
1955	++ mStat.minRaysNodes;
1956
1957	if (data.GetAvgRayContribution() > mTermMaxRayContribution)
1958	++ mStat.maxRayContribNodes;
1959
1960	if (data.mProbability <= mTermMinProbability)
1961	++ mStat.minProbabilityNodes;
1962
1963	#ifdef _DEBUG
1964	Debug << "BSP stats: "
1965	<< "Depth: " << data.mDepth << " (max: " << mTermMaxDepth << "), "
1966	<< "PVS: " << data.mPvs << " (min: " << mTermMinPvs << "), "
1967	<< "Probability: " << data.mProbability << " (min: " << mTermMinProbability << "), "
1968	<< "#polygons: " << (int)data.mPolygons->size() << " (max: " << mTermMinPolys << "), "
1969	<< "#rays: " << (int)data.mRays->size() << " (max: " << mTermMinRays << "), "
1970	<< "#pvs: " << leaf->GetViewCell()->GetPvs().GetSize() << "=, "
1971	<< "#avg ray contrib (pvs): " << (float)data.mPvs / (float)data.mRays->size() << endl;
1972	#endif
1973	}
1974
1975	int
1976	BspTree::_CastRay(Ray &ray)
1977	{
1978	int hits = 0;
1979
1980	stack<BspRayTraversalData> tStack;
1981
1982	float maxt, mint;
1983
1984	if (!mBox.GetRaySegment(ray, mint, maxt))
1985	return 0;
1986
1987	ViewCell::NewMail();
1988
1989	Vector3 entp = ray.Extrap(mint);
1990	Vector3 extp = ray.Extrap(maxt);
1991
1992	BspNode *node = mRoot;
1993	BspNode *farChild = NULL;
1994
1995	while (1)
1996	{
1997	if (!node->IsLeaf())
1998	{
1999	BspInterior in = dynamic_cast<BspInterior >(node);
2000
2001	Plane3 splitPlane = in->GetPlane();
2002	const int entSide = splitPlane.Side(entp);
2003	const int extSide = splitPlane.Side(extp);
2004
2005	if (entSide < 0)
2006	{
2007	node = in->GetBack();
2008
2009	if(extSide <= 0) // plane does not split ray => no far child
2010	continue;
2011
2012	farChild = in->GetFront(); // plane splits ray
2013
2014	} else if (entSide > 0)
2015	{
2016	node = in->GetFront();
2017
2018	if (extSide >= 0) // plane does not split ray => no far child
2019	continue;
2020
2021	farChild = in->GetBack(); // plane splits ray
2022	}
2023	else // ray and plane are coincident
2024	{
2025	// WHAT TO DO IN THIS CASE ?
2026	//break;
2027	node = in->GetFront();
2028	continue;
2029	}
2030
2031	// push data for far child
2032	tStack.push(BspRayTraversalData(farChild, extp, maxt));
2033
2034	// find intersection of ray segment with plane
2035	float t;
2036	extp = splitPlane.FindIntersection(ray.GetLoc(), extp, &t);
2037	maxt *= t;
2038
2039	} else // reached leaf => intersection with view cell
2040	{
2041	BspLeaf leaf = dynamic_cast<BspLeaf >(node);
2042
2043	if (!leaf->mViewCell->Mailed())
2044	{
2045	//ray.bspIntersections.push_back(Ray::BspIntersection(maxt, leaf));
2046	leaf->mViewCell->Mail();
2047	++ hits;
2048	}
2049
2050	//-- fetch the next far child from the stack
2051	if (tStack.empty())
2052	break;
2053
2054	entp = extp;
2055	mint = maxt; // NOTE: need this?
2056
2057	if (ray.GetType() == Ray::LINE_SEGMENT && mint > 1.0f)
2058	break;
2059
2060	BspRayTraversalData &s = tStack.top();
2061
2062	node = s.mNode;
2063	extp = s.mExitPoint;
2064	maxt = s.mMaxT;
2065
2066	tStack.pop();
2067	}
2068	}
2069
2070	return hits;
2071	}
2072
2073
2074	int BspTree::CastLineSegment(const Vector3 &origin,
2075	const Vector3 &termination,
2076	vector<ViewCell *> &viewcells)
2077	{
2078	int hits = 0;
2079	stack<BspRayTraversalData> tStack;
2080
2081	float mint = 0.0f, maxt = 1.0f;
2082
2083	Intersectable::NewMail();
2084	ViewCell::NewMail();
2085
2086	Vector3 entp = origin;
2087	Vector3 extp = termination;
2088
2089	BspNode *node = mRoot;
2090	BspNode *farChild = NULL;
2091
2092	const float thresh = 1 ? 1e-6f : 0.0f;
2093
2094	while (1)
2095	{
2096	if (!node->IsLeaf())
2097	{
2098	BspInterior in = dynamic_cast<BspInterior >(node);
2099
2100	Plane3 splitPlane = in->GetPlane();
2101
2102	const int entSide = splitPlane.Side(entp, thresh);
2103	const int extSide = splitPlane.Side(extp, thresh);
2104
2105	if (entSide < 0)
2106	{
2107	node = in->GetBack();
2108
2109	if(extSide <= 0) // plane does not split ray => no far child
2110	continue;
2111
2112	farChild = in->GetFront(); // plane splits ray
2113
2114	}
2115	else if (entSide > 0)
2116	{
2117	node = in->GetFront();
2118
2119	if (extSide >= 0) // plane does not split ray => no far child
2120	continue;
2121
2122	farChild = in->GetBack(); // plane splits ray
2123	}
2124	else // ray and plane are coincident
2125	{
2126	// NOTE: what to do if ray is coincident with plane?
2127	if (extSide < 0)
2128	node = in->GetBack();
2129	else
2130	node = in->GetFront();
2131
2132	continue; // no far child
2133	}
2134
2135	// push data for far child
2136	tStack.push(BspRayTraversalData(farChild, extp, maxt));
2137
2138	// find intersection of ray segment with plane
2139	float t;
2140	extp = splitPlane.FindIntersection(origin, extp, &t);
2141	maxt *= t;
2142	}
2143	else
2144	{
2145	// reached leaf => intersection with view cell
2146	BspLeaf leaf = dynamic_cast<BspLeaf >(node);
2147
2148	if (!leaf->mViewCell->Mailed())
2149	{
2150	viewcells.push_back(leaf->mViewCell);
2151	leaf->mViewCell->Mail();
2152	hits++;
2153	}
2154
2155	//-- fetch the next far child from the stack
2156	if (tStack.empty())
2157	break;
2158
2159	entp = extp;
2160	mint = maxt; // NOTE: need this?
2161
2162	BspRayTraversalData &s = tStack.top();
2163
2164	node = s.mNode;
2165	extp = s.mExitPoint;
2166	maxt = s.mMaxT;
2167
2168	tStack.pop();
2169	}
2170	}
2171	return hits;
2172	}
2173
2174
2175	void BspTree::CollectViewCells(ViewCellContainer &viewCells) const
2176	{
2177	stack<BspNode *> nodeStack;
2178	nodeStack.push(mRoot);
2179
2180	ViewCell::NewMail();
2181
2182	while (!nodeStack.empty())
2183	{
2184	BspNode *node = nodeStack.top();
2185	nodeStack.pop();
2186
2187	if (node->IsLeaf())
2188	{
2189	ViewCell viewCell = dynamic_cast<BspLeaf >(node)->mViewCell;
2190
2191	if (!viewCell->Mailed())
2192	{
2193	viewCell->Mail();
2194	viewCells.push_back(viewCell);
2195	}
2196	}
2197	else
2198	{
2199	BspInterior interior = dynamic_cast<BspInterior >(node);
2200
2201	nodeStack.push(interior->GetFront());
2202	nodeStack.push(interior->GetBack());
2203	}
2204	}
2205	}
2206
2207
2208	BspTreeStatistics &BspTree::GetStat()
2209	{
2210	return mStat;
2211	}
2212
2213
2214	float BspTree::AccumulatedRayLength(BoundedRayContainer &rays) const
2215	{
2216	float len = 0;
2217
2218	BoundedRayContainer::const_iterator it, it_end = rays.end();
2219
2220	for (it = rays.begin(); it != it_end; ++ it)
2221	{
2222	len += SqrDistance((it)->mRay->Extrap((it)->mMinT),
2223	(it)->mRay->Extrap((it)->mMaxT));
2224	}
2225
2226	return len;
2227	}
2228
2229
2230	int BspTree::SplitRays(const Plane3 &plane,
2231	BoundedRayContainer &rays,
2232	BoundedRayContainer &frontRays,
2233	BoundedRayContainer &backRays)
2234	{
2235	int splits = 0;
2236
2237	while (!rays.empty())
2238	{
2239	BoundedRay *bRay = rays.back();
2240	Ray *ray = bRay->mRay;
2241	float minT = bRay->mMinT;
2242	float maxT = bRay->mMaxT;
2243
2244	rays.pop_back();
2245
2246	Vector3 entP, extP;
2247
2248	const int cf =
2249	ray->ClassifyPlane(plane, minT, maxT, entP, extP);
2250
2251	// set id to ray classification
2252	ray->SetId(cf);
2253
2254	switch (cf)
2255	{
2256	case Ray::COINCIDENT: // TODO: should really discard ray?
2257	frontRays.push_back(bRay);
2258	//DEL_PTR(bRay);
2259	break;
2260	case Ray::BACK:
2261	backRays.push_back(bRay);
2262	break;
2263	case Ray::FRONT:
2264	frontRays.push_back(bRay);
2265	break;
2266	case Ray::FRONT_BACK:
2267	{
2268	// find intersection of ray segment with plane
2269	const float t = plane.FindT(ray->GetLoc(), extP);
2270
2271	const float newT = t * maxT;
2272
2273	frontRays.push_back(new BoundedRay(ray, minT, newT));
2274	backRays.push_back(new BoundedRay(ray, newT, maxT));
2275
2276	DEL_PTR(bRay);
2277	}
2278	break;
2279	case Ray::BACK_FRONT:
2280	{
2281	// find intersection of ray segment with plane
2282	const float t = plane.FindT(ray->GetLoc(), extP);
2283	const float newT = t * bRay->mMaxT;
2284
2285	backRays.push_back(new BoundedRay(ray, minT, newT));
2286	frontRays.push_back(new BoundedRay(ray, newT, maxT));
2287
2288	DEL_PTR(bRay);
2289
2290	++ splits;
2291	}
2292	break;
2293	default:
2294	Debug << "Should not come here 4" << endl;
2295	break;
2296	}
2297	}
2298
2299	return splits;
2300	}
2301
2302	void BspTree::ExtractHalfSpaces(BspNode *n, vector<Plane3> &halfSpaces) const
2303	{
2304	BspNode *lastNode;
2305
2306	do
2307	{
2308	lastNode = n;
2309
2310	// want to get planes defining geometry of this node => don't take
2311	// split plane of node itself
2312	n = n->GetParent();
2313
2314	if (n)
2315	{
2316	BspInterior interior = dynamic_cast<BspInterior >(n);
2317	Plane3 halfSpace = dynamic_cast<BspInterior *>(interior)->GetPlane();
2318
2319	if (interior->GetFront() != lastNode)
2320	halfSpace.ReverseOrientation();
2321
2322	halfSpaces.push_back(halfSpace);
2323	}
2324	}
2325	while (n);
2326	}
2327
2328
2329
2330	void BspTree::ConstructGeometry(ViewCell *vc,
2331	BspNodeGeometry &vcGeom) const
2332	{
2333	ViewCellContainer leaves;
2334	mViewCellsTree->CollectLeaves(vc, leaves);
2335
2336	ViewCellContainer::const_iterator it, it_end = leaves.end();
2337
2338	for (it = leaves.begin(); it != it_end; ++ it)
2339	{
2340	BspLeaf l = dynamic_cast<BspViewCell >(*it)->mLeaf;
2341	ConstructGeometry(l, vcGeom);
2342	}
2343	}
2344
2345
2346	void BspTree::SetViewCellsManager(ViewCellsManager *vcm)
2347	{
2348	mViewCellsManager = vcm;
2349	}
2350
2351
2352	void BspTree::ConstructGeometry(BspNode *n, BspNodeGeometry &geom) const
2353	{
2354	vector<Plane3> halfSpaces;
2355	ExtractHalfSpaces(n, halfSpaces);
2356
2357	PolygonContainer candidates;
2358	vector<Plane3> candidatePlanes;
2359
2360	// bounded planes are added to the polygons (reverse polygons
2361	// as they have to be outfacing
2362	// comment: why is this?
2363	for (int i = 0; i < (int)halfSpaces.size(); ++ i)
2364	{
2365	Polygon3 *p = GetBoundingBox().CrossSection(halfSpaces[i]);
2366
2367	if (p->Valid(mEpsilon))
2368	{
2369	candidates.push_back(p->CreateReversePolygon());
2370
2371	Plane3 candidatePlane = p->GetSupportingPlane();//halfSpaces[i];
2372	//candidatePlane.ReverseOrientation();
2373	candidatePlanes.push_back(candidatePlane);
2374
2375	DEL_PTR(p);
2376	}
2377	}
2378
2379	// add faces of bounding box (also could be faces of the cell)
2380	for (int i = 0; i < 6; ++ i)
2381	{
2382	VertexContainer vertices;
2383
2384	for (int j = 0; j < 4; ++ j)
2385	vertices.push_back(mBox.GetFace(i).mVertices[j]);
2386
2387	Polygon3 *poly = new Polygon3(vertices);
2388	candidates.push_back(new Polygon3(vertices));
2389	candidatePlanes.push_back(poly->GetSupportingPlane());
2390	}
2391
2392
2393	for (int i = 0; i < (int)candidates.size(); ++ i)
2394	{
2395	// polygon is split by all other planes
2396	for (int j = 0; (j < (int)halfSpaces.size()) && candidates[i]; ++ j)
2397	{
2398	if (i == j) // polygon and plane are coincident
2399	continue;
2400
2401	VertexContainer splitPts;
2402	Polygon3 frontPoly, backPoly;
2403
2404	const int cf = candidates[i]->
2405	ClassifyPlane(halfSpaces[j], mEpsilon);
2406
2407	switch (cf)
2408	{
2409	case Polygon3::SPLIT:
2410	frontPoly = new Polygon3();
2411	backPoly = new Polygon3();
2412
2413	candidates[i]->Split(halfSpaces[j],
2414	*frontPoly,
2415	*backPoly,
2416	mEpsilon);
2417
2418	DEL_PTR(candidates[i]);
2419
2420	if (frontPoly->Valid(mEpsilon))
2421	candidates[i] = frontPoly;
2422	else
2423	DEL_PTR(frontPoly);
2424
2425	DEL_PTR(backPoly);
2426	break;
2427	case Polygon3::BACK_SIDE:
2428	DEL_PTR(candidates[i]);
2429	break;
2430	// just take polygon as it is
2431	case Polygon3::FRONT_SIDE:
2432	case Polygon3::COINCIDENT:
2433	default:
2434	break;
2435	}
2436	}
2437
2438	if (candidates[i])
2439	{
2440	geom.Add(candidates[i], candidatePlanes[i]);
2441	// geom.mPolys.push_back(candidates[i]);
2442	}
2443	}
2444	}
2445
2446
2447	typedef pair<BspNode , BspNodeGeometry > bspNodePair;
2448
2449
2450	int BspTree::FindNeighbors(BspNode n, vector<BspLeaf > &neighbors,
2451	const bool onlyUnmailed) const
2452	{
2453	stack<bspNodePair> nodeStack;
2454
2455	BspNodeGeometry nodeGeom;
2456	ConstructGeometry(n, nodeGeom);
2457
2458	// split planes from the root to this node
2459	// needed to verify that we found neighbor leaf
2460	// TODO: really needed?
2461	vector<Plane3> halfSpaces;
2462	ExtractHalfSpaces(n, halfSpaces);
2463
2464
2465	BspNodeGeometry *rgeom = new BspNodeGeometry();
2466	ConstructGeometry(mRoot, *rgeom);
2467
2468	nodeStack.push(bspNodePair(mRoot, rgeom));
2469
2470	while (!nodeStack.empty())
2471	{
2472	BspNode *node = nodeStack.top().first;
2473	BspNodeGeometry *geom = nodeStack.top().second;
2474
2475	nodeStack.pop();
2476
2477	if (node->IsLeaf())
2478	{
2479	// test if this leaf is in valid view space
2480	if (node->TreeValid() &&
2481	(node != n) &&
2482	(!onlyUnmailed \|\| !node->Mailed()))
2483	{
2484	bool isAdjacent = true;
2485
2486	if (1)
2487	{
2488	// test all planes of current node if still adjacent
2489	for (int i = 0; (i < halfSpaces.size()) && isAdjacent; ++ i)
2490	{
2491	const int cf =
2492	Polygon3::ClassifyPlane(geom->GetPolys(),
2493	halfSpaces[i],
2494	mEpsilon);
2495
2496	if (cf == Polygon3::BACK_SIDE)
2497	{
2498	isAdjacent = false;
2499	}
2500	}
2501	}
2502	else
2503	{
2504	// TODO: why is this wrong??
2505	// test all planes of current node if still adjacent
2506	for (int i = 0; (i < nodeGeom.Size()) && isAdjacent; ++ i)
2507	{
2508	Polygon3 *poly = nodeGeom.GetPolys()[i];
2509
2510	const int cf =
2511	Polygon3::ClassifyPlane(geom->GetPolys(),
2512	poly->GetSupportingPlane(),
2513	mEpsilon);
2514
2515	if (cf == Polygon3::BACK_SIDE)
2516	{
2517	isAdjacent = false;
2518	}
2519	}
2520	}
2521	// neighbor was found
2522	if (isAdjacent)
2523	{
2524	neighbors.push_back(dynamic_cast<BspLeaf *>(node));
2525	}
2526	}
2527	}
2528	else
2529	{
2530	BspInterior interior = dynamic_cast<BspInterior >(node);
2531
2532	const int cf = Polygon3::ClassifyPlane(nodeGeom.GetPolys(),
2533	interior->GetPlane(),
2534	mEpsilon);
2535
2536	BspNode *front = interior->GetFront();
2537	BspNode *back = interior->GetBack();
2538
2539	BspNodeGeometry *fGeom = new BspNodeGeometry();
2540	BspNodeGeometry *bGeom = new BspNodeGeometry();
2541
2542	geom->SplitGeometry(*fGeom,
2543	*bGeom,
2544	interior->GetPlane(),
2545	mBox,
2546	mEpsilon);
2547
2548	if (cf == Polygon3::FRONT_SIDE)
2549	{
2550	nodeStack.push(bspNodePair(interior->GetFront(), fGeom));
2551	DEL_PTR(bGeom);
2552	}
2553	else
2554	{
2555	if (cf == Polygon3::BACK_SIDE)
2556	{
2557	nodeStack.push(bspNodePair(interior->GetBack(), bGeom));
2558	DEL_PTR(fGeom);
2559	}
2560	else
2561	{ // random decision
2562	nodeStack.push(bspNodePair(front, fGeom));
2563	nodeStack.push(bspNodePair(back, bGeom));
2564	}
2565	}
2566	}
2567
2568	DEL_PTR(geom);
2569	}
2570
2571	return (int)neighbors.size();
2572	}
2573
2574
2575	BspLeaf *BspTree::GetRandomLeaf(const Plane3 &halfspace)
2576	{
2577	stack<BspNode *> nodeStack;
2578	nodeStack.push(mRoot);
2579
2580	int mask = rand();
2581
2582	while (!nodeStack.empty())
2583	{
2584	BspNode *node = nodeStack.top();
2585	nodeStack.pop();
2586
2587	if (node->IsLeaf())
2588	{
2589	return dynamic_cast<BspLeaf *>(node);
2590	}
2591	else
2592	{
2593	BspInterior interior = dynamic_cast<BspInterior >(node);
2594	BspNode *next;
2595
2596	BspNodeGeometry geom;
2597	// todo: not very efficient: constructs full cell everytime
2598	ConstructGeometry(interior, geom);
2599
2600	const int cf = Polygon3::ClassifyPlane(geom.GetPolys(),
2601	halfspace,
2602	mEpsilon);
2603
2604	if (cf == Polygon3::BACK_SIDE)
2605	next = interior->GetFront();
2606	else
2607	if (cf == Polygon3::FRONT_SIDE)
2608	next = interior->GetFront();
2609	else
2610	{
2611	// random decision
2612	if (mask & 1)
2613	next = interior->GetBack();
2614	else
2615	next = interior->GetFront();
2616	mask = mask >> 1;
2617	}
2618
2619	nodeStack.push(next);
2620	}
2621	}
2622
2623	return NULL;
2624	}
2625
2626
2627	BspLeaf *BspTree::GetRandomLeaf(const bool onlyUnmailed)
2628	{
2629	stack<BspNode *> nodeStack;
2630
2631	nodeStack.push(mRoot);
2632
2633	int mask = rand();
2634
2635	while (!nodeStack.empty())
2636	{
2637	BspNode *node = nodeStack.top();
2638	nodeStack.pop();
2639
2640	if (node->IsLeaf())
2641	{
2642	if ( (!onlyUnmailed \|\| !node->Mailed()) )
2643	return dynamic_cast<BspLeaf *>(node);
2644	}
2645	else
2646	{
2647	BspInterior interior = dynamic_cast<BspInterior >(node);
2648
2649	// random decision
2650	if (mask & 1)
2651	nodeStack.push(interior->GetBack());
2652	else
2653	nodeStack.push(interior->GetFront());
2654
2655	mask = mask >> 1;
2656	}
2657	}
2658
2659	return NULL;
2660	}
2661
2662
2663	void BspTree::AddToPvs(BspLeaf *leaf,
2664	const BoundedRayContainer &rays,
2665	int &sampleContributions,
2666	int &contributingSamples)
2667	{
2668	sampleContributions = 0;
2669	contributingSamples = 0;
2670
2671	BoundedRayContainer::const_iterator it, it_end = rays.end();
2672
2673	ViewCell *vc = leaf->GetViewCell();
2674
2675	// add contributions from samples to the PVS
2676	for (it = rays.begin(); it != it_end; ++ it)
2677	{
2678	int contribution = 0;
2679	Ray ray = (it)->mRay;
2680	float relContribution;
2681	if (!ray->intersections.empty())
2682	contribution += vc->GetPvs().AddSample(ray->intersections[0].mObject,
2683	1.0f,
2684	relContribution);
2685
2686	if (ray->sourceObject.mObject)
2687	contribution += vc->GetPvs().AddSample(ray->sourceObject.mObject,
2688	1.0f,
2689	relContribution);
2690
2691	if (contribution)
2692	{
2693	sampleContributions += contribution;
2694	++ contributingSamples;
2695	}
2696
2697	//if (ray->mFlags & Ray::STORE_BSP_INTERSECTIONS)
2698	// ray->bspIntersections.push_back(Ray::BspIntersection((*it)->mMinT, this));
2699	}
2700	}
2701
2702
2703	int BspTree::ComputePvsSize(const BoundedRayContainer &rays) const
2704	{
2705	int pvsSize = 0;
2706
2707	BoundedRayContainer::const_iterator rit, rit_end = rays.end();
2708
2709	Intersectable::NewMail();
2710
2711	for (rit = rays.begin(); rit != rays.end(); ++ rit)
2712	{
2713	Ray ray = (rit)->mRay;
2714
2715	if (!ray->intersections.empty())
2716	{
2717	if (!ray->intersections[0].mObject->Mailed())
2718	{
2719	ray->intersections[0].mObject->Mail();
2720	++ pvsSize;
2721	}
2722	}
2723	if (ray->sourceObject.mObject)
2724	{
2725	if (!ray->sourceObject.mObject->Mailed())
2726	{
2727	ray->sourceObject.mObject->Mail();
2728	++ pvsSize;
2729	}
2730	}
2731	}
2732
2733	return pvsSize;
2734	}
2735
2736
2737	float BspTree::GetEpsilon() const
2738	{
2739	return mEpsilon;
2740	}
2741
2742
2743	int BspTree::CollectMergeCandidates(const vector<BspLeaf *> leaves,
2744	vector<MergeCandidate> &candidates)
2745	{
2746	BspLeaf::NewMail();
2747
2748	vector<BspLeaf *>::const_iterator it, it_end = leaves.end();
2749
2750	int numCandidates = 0;
2751
2752	// find merge candidates and push them into queue
2753	for (it = leaves.begin(); it != it_end; ++ it)
2754	{
2755	BspLeaf leaf = it;
2756
2757	// the same leaves must not be part of two merge candidates
2758	leaf->Mail();
2759	vector<BspLeaf *> neighbors;
2760	FindNeighbors(leaf, neighbors, true);
2761
2762	vector<BspLeaf *>::const_iterator nit, nit_end = neighbors.end();
2763
2764	// TODO: test if at least one ray goes from one leaf to the other
2765	for (nit = neighbors.begin(); nit != nit_end; ++ nit)
2766	{
2767	if ((*nit)->GetViewCell() != leaf->GetViewCell())
2768	{
2769	MergeCandidate mc(leaf->GetViewCell(), (*nit)->GetViewCell());
2770	candidates.push_back(mc);
2771
2772	++ numCandidates;
2773	if ((numCandidates % 1000) == 0)
2774	{
2775	cout << "collected " << numCandidates << " merge candidates" << endl;
2776	}
2777	}
2778	}
2779	}
2780
2781	Debug << "merge queue: " << (int)candidates.size() << endl;
2782	Debug << "leaves in queue: " << numCandidates << endl;
2783
2784
2785	return (int)leaves.size();
2786	}
2787
2788
2789	int BspTree::CollectMergeCandidates(const VssRayContainer &rays,
2790	vector<MergeCandidate> &candidates)
2791	{
2792	ViewCell::NewMail();
2793	long startTime = GetTime();
2794
2795	map<BspLeaf , vector<BspLeaf> > neighborMap;
2796	ViewCellContainer::const_iterator iit;
2797
2798	int numLeaves = 0;
2799
2800	BspLeaf::NewMail();
2801
2802	for (int i = 0; i < (int)rays.size(); ++ i)
2803	{
2804	VssRay *ray = rays[i];
2805
2806	// traverse leaves stored in the rays and compare and
2807	// merge consecutive leaves (i.e., the neighbors in the tree)
2808	if (ray->mViewCells.size() < 2)
2809	continue;
2810
2811	iit = ray->mViewCells.begin();
2812	BspViewCell bspVc = dynamic_cast<BspViewCell >(*(iit ++));
2813	BspLeaf *leaf = bspVc->mLeaf;
2814
2815	// traverse intersections
2816	// consecutive leaves are neighbors => add them to queue
2817	for (; iit != ray->mViewCells.end(); ++ iit)
2818	{
2819	// next pair
2820	BspLeaf *prevLeaf = leaf;
2821	bspVc = dynamic_cast<BspViewCell >(iit);
2822	leaf = bspVc->mLeaf;
2823
2824	// view space not valid or same view cell
2825	if (!leaf->TreeValid() \|\| !prevLeaf->TreeValid() \|\|
2826	(leaf->GetViewCell() == prevLeaf->GetViewCell()))
2827	continue;
2828
2829	vector<BspLeaf *> &neighbors = neighborMap[leaf];
2830
2831	bool found = false;
2832
2833	// both leaves inserted in queue already =>
2834	// look if double pair already exists
2835	if (leaf->Mailed() && prevLeaf->Mailed())
2836	{
2837	vector<BspLeaf *>::const_iterator it, it_end = neighbors.end();
2838
2839	for (it = neighbors.begin(); !found && (it != it_end); ++ it)
2840	if (*it == prevLeaf)
2841	found = true; // already in queue
2842	}
2843
2844	if (!found)
2845	{
2846	// this pair is not in map yet
2847	// => insert into the neighbor map and the queue
2848	neighbors.push_back(prevLeaf);
2849	neighborMap[prevLeaf].push_back(leaf);
2850
2851	leaf->Mail();
2852	prevLeaf->Mail();
2853
2854	MergeCandidate mc(leaf->GetViewCell(), prevLeaf->GetViewCell());
2855
2856	candidates.push_back(mc);
2857
2858	if (((int)candidates.size() % 1000) == 0)
2859	{
2860	cout << "collected " << (int)candidates.size() << " merge candidates" << endl;
2861	}
2862	}
2863	}
2864	}
2865
2866	Debug << "neighbormap size: " << (int)neighborMap.size() << endl;
2867	Debug << "merge queue: " << (int)candidates.size() << endl;
2868	Debug << "leaves in queue: " << numLeaves << endl;
2869
2870
2871	//-- collect the leaves which haven't been found by ray casting
2872	#if 0
2873	cout << "finding additional merge candidates using geometry" << endl;
2874	vector<BspLeaf *> leaves;
2875	CollectLeaves(leaves, true);
2876	Debug << "found " << (int)leaves.size() << " new leaves" << endl << endl;
2877	CollectMergeCandidates(leaves, candidates);
2878	#endif
2879
2880	return numLeaves;
2881	}
2882
2883
2884
2885
2886	/***************************************************************/
2887	/* BspNodeGeometry Implementation */
2888	/***************************************************************/
2889
2890
2891	BspNodeGeometry::BspNodeGeometry(const BspNodeGeometry &rhs)
2892	{
2893	mPolys.reserve(rhs.mPolys.size());
2894
2895	PolygonContainer::const_iterator it, it_end = rhs.mPolys.end();
2896
2897	int i = 0;
2898
2899	for (it = rhs.mPolys.begin(); it != it_end; ++ it)
2900	{
2901	Polygon3 poly = it;
2902	Add(new Polygon3(*poly), rhs.mPlanes[i ++]);
2903	}
2904	}
2905
2906
2907	BspNodeGeometry::~BspNodeGeometry()
2908	{
2909	CLEAR_CONTAINER(mPolys);
2910	}
2911
2912
2913	int BspNodeGeometry::Size() const
2914	{
2915	return (int)mPolys.size();
2916	}
2917
2918
2919	const PolygonContainer &BspNodeGeometry::GetPolys()
2920	{
2921	return mPolys;
2922	}
2923
2924
2925	void BspNodeGeometry::Add(Polygon3 *p, const Plane3 &plane)
2926	{
2927	mPolys.push_back(p);
2928	mPlanes.push_back(plane);
2929	}
2930
2931
2932	float BspNodeGeometry::GetArea() const
2933	{
2934	return Polygon3::GetArea(mPolys);
2935	}
2936
2937
2938	float BspNodeGeometry::GetVolume() const
2939	{
2940	//-- compute volume using tetrahedralization of the geometry
2941	// and adding the volume of the single tetrahedrons
2942	float volume = 0;
2943	const float f = 1.0f / 6.0f;
2944
2945	PolygonContainer::const_iterator pit, pit_end = mPolys.end();
2946
2947	// note: can take arbitrary point, e.g., the origin. However,
2948	// we rather take the center of mass to prevents precision errors
2949	const Vector3 center = CenterOfMass();
2950
2951	for (pit = mPolys.begin(); pit != pit_end; ++ pit)
2952	{
2953	Polygon3 poly = pit;
2954	const Vector3 v0 = poly->mVertices[0] - center;
2955
2956	for (int i = 1; i < (int)poly->mVertices.size() - 1; ++ i)
2957	{
2958	const Vector3 v1 = poly->mVertices[i] - center;
2959	const Vector3 v2 = poly->mVertices[i + 1] - center;
2960
2961	// more robust version using abs and the center of mass
2962	volume += fabs (f * (DotProd(v0, CrossProd(v1, v2))));
2963	}
2964	}
2965
2966	return volume;
2967	}
2968
2969
2970	Vector3 BspNodeGeometry::CenterOfMass() const
2971	{
2972	int n = 0;
2973
2974	Vector3 center(0,0,0);
2975
2976	PolygonContainer::const_iterator pit, pit_end = mPolys.end();
2977
2978	for (pit = mPolys.begin(); pit != pit_end; ++ pit)
2979	{
2980	Polygon3 poly = pit;
2981
2982	VertexContainer::const_iterator vit, vit_end = poly->mVertices.end();
2983
2984	for(vit = poly->mVertices.begin(); vit != vit_end; ++ vit)
2985	{
2986	center += *vit;
2987	++ n;
2988	}
2989	}
2990
2991	//Debug << "center: " << center << " new " << center / (float)n << endl;
2992
2993	return center / (float)n;
2994	}
2995
2996
2997	bool BspNodeGeometry::Valid() const
2998	{
2999	if (mPolys.size() < 4)
3000	return false;
3001
3002	return true;
3003	}
3004
3005
3006	void BspNodeGeometry::AddToMesh(Mesh &mesh)
3007	{
3008	PolygonContainer::const_iterator it, it_end = mPolys.end();
3009
3010	for (it = mPolys.begin(); it != mPolys.end(); ++ it)
3011	{
3012	(*it)->AddToMesh(mesh);
3013	}
3014	}
3015
3016
3017	bool BspNodeGeometry::SplitGeometry(BspNodeGeometry &front,
3018	BspNodeGeometry &back,
3019	const Plane3 &splitPlane,
3020	const AxisAlignedBox3 &box,
3021	const float epsilon) const
3022	{
3023	// get cross section of new polygon
3024	Polygon3 *planePoly = box.CrossSection(splitPlane);
3025
3026	// split polygon with all other polygons
3027	planePoly = SplitPolygon(planePoly, epsilon);
3028
3029	bool splitsGeom = (planePoly != NULL)
3030
3031
3032	//-- new polygon splits all other polygons
3033	for (int i = 0; i < (int)mPolys.size()/* && planePoly*/; ++ i)
3034	{
3035	/// don't use epsilon here to get exact split planes
3036	const int cf =
3037	mPolys[i]->ClassifyPlane(splitPlane, epsilon);
3038
3039	switch (cf)
3040	{
3041	case Polygon3::SPLIT:
3042	{
3043	Polygon3 *poly = new Polygon3(mPolys[i]->mVertices);
3044
3045	Polygon3 *frontPoly = new Polygon3();
3046	Polygon3 *backPoly = new Polygon3();
3047
3048	poly->Split(splitPlane,
3049	*frontPoly,
3050	*backPoly,
3051	epsilon);
3052
3053	DEL_PTR(poly);
3054
3055	if (frontPoly->Valid(epsilon))
3056	{
3057	front.Add(frontPoly, mPlanes[i]);
3058	}
3059	else
3060	{
3061	//Debug << "no f! " << endl;
3062	DEL_PTR(frontPoly);
3063	}
3064
3065	if (backPoly->Valid(epsilon))
3066	{
3067	back.Add(backPoly, mPlanes[i]);
3068	}
3069	else
3070	{
3071	//Debug << "no b! " << endl;
3072	DEL_PTR(backPoly);
3073	}
3074	}
3075
3076	break;
3077	case Polygon3::BACK_SIDE:
3078	back.Add(new Polygon3(mPolys[i]->mVertices), mPlanes[i]);
3079	break;
3080	case Polygon3::FRONT_SIDE:
3081	front.Add(new Polygon3(mPolys[i]->mVertices), mPlanes[i]);
3082	break;
3083	// only put into back container (split should have no effect ...)
3084	case Polygon3::COINCIDENT:
3085	Debug << "error should not come here" << endl;
3086	splitsGeom = false;
3087
3088	if (DotProd(mPlanes[i].mNormal, splitPlane.mNormal > 0))
3089	back.Add(new Polygon3(mPolys[i]->mVertices), mPlanes[i]);
3090	else
3091	front.Add(new Polygon3(mPolys[i]->mVertices), mPlanes[i]);
3092	break;
3093	default:
3094	break;
3095	}
3096	}
3097
3098	//-- finally add the new polygon to the child node geometries
3099	if (planePoly)
3100	{
3101	// add polygon with normal pointing into positive half space to back cell
3102	back.Add(planePoly, splitPlane);
3103	//back.mPolys.push_back(planePoly);
3104
3105	// add polygon with reverse orientation to front cell
3106	Plane3 reversePlane(splitPlane);
3107	reversePlane.ReverseOrientation();
3108	front.Add(planePoly->CreateReversePolygon(), reversePlane);
3109	}
3110
3111
3112	return splitsGeom;
3113	}
3114
3115
3116	Polygon3 BspNodeGeometry::SplitPolygon(Polygon3 planePoly,
3117	const float epsilon) const
3118	{
3119	if (!planePoly->Valid(epsilon))
3120	DEL_PTR(planePoly);
3121
3122	// polygon is split by all other planes
3123	for (int i = 0; (i < (int)mPolys.size()) && planePoly; ++ i)
3124	{
3125	#if 0
3126	Plane3 plane = mPolys[i]->GetSupportingPlane();
3127	#else
3128	Plane3 plane = mPlanes[i];
3129
3130	#endif
3131	/// don't use epsilon here to get exact split planes
3132	const int cf =
3133	planePoly->ClassifyPlane(plane, epsilon);
3134
3135	// split new polygon with all previous planes
3136	switch (cf)
3137	{
3138	case Polygon3::SPLIT:
3139	{
3140	Polygon3 *frontPoly = new Polygon3();
3141	Polygon3 *backPoly = new Polygon3();
3142
3143	planePoly->Split(plane,
3144	*frontPoly,
3145	*backPoly,
3146	epsilon);
3147
3148	// don't need anymore
3149	DEL_PTR(planePoly);
3150	DEL_PTR(frontPoly);
3151
3152	// back polygon is belonging to geometry
3153	if (backPoly->Valid(epsilon))
3154	planePoly = backPoly;
3155	else
3156	DEL_PTR(backPoly);
3157	}
3158	break;
3159	case Polygon3::FRONT_SIDE:
3160	DEL_PTR(planePoly);
3161	break;
3162	// polygon is taken as it is
3163	case Polygon3::BACK_SIDE:
3164	case Polygon3::COINCIDENT:
3165	default:
3166	break;
3167	}
3168	}
3169
3170	return planePoly;
3171	}
3172
3173
3174	ViewCell *BspTree::GetViewCell(const Vector3 &point)
3175	{
3176	if (mRoot == NULL)
3177	return NULL;
3178
3179
3180	stack<BspNode *> nodeStack;
3181	nodeStack.push(mRoot);
3182
3183	ViewCell *viewcell = NULL;
3184
3185	while (!nodeStack.empty()) {
3186	BspNode *node = nodeStack.top();
3187	nodeStack.pop();
3188
3189	if (node->IsLeaf()) {
3190	viewcell = dynamic_cast<BspLeaf *>(node)->mViewCell;
3191	break;
3192	} else {
3193
3194	BspInterior interior = dynamic_cast<BspInterior >(node);
3195
3196	// random decision
3197	if (interior->GetPlane().Side(point) < 0)
3198	nodeStack.push(interior->GetBack());
3199	else
3200	nodeStack.push(interior->GetFront());
3201	}
3202	}
3203
3204	return viewcell;
3205	}
3206
3207
3208	void BspNodeGeometry::IncludeInBox(AxisAlignedBox3 &box)
3209	{
3210	Polygon3::IncludeInBox(mPolys, box);
3211	}
3212
3213
3214	bool BspTree::Export(ofstream &stream)
3215	{
3216	ExportNode(mRoot, stream);
3217
3218	return true;
3219	}
3220
3221
3222	void BspTree::ExportNode(BspNode *node, ofstream &stream)
3223	{
3224	if (node->IsLeaf())
3225	{
3226	BspLeaf leaf = dynamic_cast<BspLeaf >(node);
3227
3228	int id = -1;
3229	if (leaf->GetViewCell() != mOutOfBoundsCell)
3230	id = leaf->GetViewCell()->GetId();
3231
3232	stream << "<Leaf viewCellId=\"" << id << "\" />" << endl;
3233	}
3234	else
3235	{
3236	BspInterior interior = dynamic_cast<BspInterior >(node);
3237
3238	Plane3 plane = interior->GetPlane();
3239	stream << "<Interior plane=\"" << plane.mNormal.x << " "
3240	<< plane.mNormal.y << " " << plane.mNormal.z << " "
3241	<< plane.mD << "\">" << endl;
3242
3243	ExportNode(interior->GetBack(), stream);
3244	ExportNode(interior->GetFront(), stream);
3245
3246	stream << "</Interior>" << endl;
3247	}
3248	}

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